root/sys/net/pf.c
/*      $OpenBSD: pf.c,v 1.1236 2026/02/05 03:26:00 dlg Exp $ */

/*
 * Copyright (c) 2001 Daniel Hartmeier
 * Copyright (c) 2002 - 2013 Henning Brauer <henning@openbsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *    - Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    - Redistributions in binary form must reproduce the above
 *      copyright notice, this list of conditions and the following
 *      disclaimer in the documentation and/or other materials provided
 *      with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Effort sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F30602-01-2-0537.
 *
 */

#include "carp.h"
#include "pflog.h"
#include "pfsync.h"
#include "pflow.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/time.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/percpu.h>
#include <sys/syslog.h>

#include <crypto/sha2.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/toeplitz.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <netinet/ip_icmp.h>
#include <netinet/tcp.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_fsm.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/ip_divert.h>

#ifdef INET6
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#endif /* INET6 */

#include <net/pfvar.h>
#include <net/pfvar_priv.h>

#if NPFLOW > 0
#include <net/if_pflow.h>
#endif  /* NPFLOW > 0 */

#if NPFSYNC > 0
#include <net/if_pfsync.h>
#endif /* NPFSYNC > 0 */

/*
 * Global variables
 */
struct pf_state_tree     pf_statetbl;
struct pf_queuehead      pf_queues[2];
struct pf_queuehead     *pf_queues_active;
struct pf_queuehead     *pf_queues_inactive;

struct pf_status         pf_status;
static struct cpumem    *pf_status_fcounters;

struct mutex             pf_inp_mtx = MUTEX_INITIALIZER(IPL_SOFTNET);

int                      pf_hdr_limit = 20;  /* arbitrary limit, tune in ddb */

SHA2_CTX                 pf_tcp_secret_ctx;
u_char                   pf_tcp_secret[16];
int                      pf_tcp_secret_init;
int                      pf_tcp_iss_off;

enum pf_test_status {
        PF_TEST_FAIL = -1,
        PF_TEST_OK,
        PF_TEST_QUICK
};

struct pf_test_ctx {
        struct pf_pdesc          *pd;
        struct pf_rule_actions    act;
        u_int8_t                  icmpcode;
        u_int8_t                  icmptype;
        int                       icmp_dir;
        int                       state_icmp;
        int                       tag;
        int                       limiter_drop;
        u_short                   reason;
        struct pf_rule_item      *ri;
        struct pf_src_node       *sns[PF_SN_MAX];
        struct pf_rule_slist      rules;
        struct pf_rule           *nr;
        struct pf_rule          **rm;
        struct pf_rule           *a;
        struct pf_rule          **am;
        struct pf_ruleset       **rsm;
        struct pf_ruleset        *arsm;
        struct pf_ruleset        *aruleset;
        struct tcphdr            *th;
        struct pf_statelim       *statelim;
        struct pf_sourcelim      *sourcelim;
        struct pf_source         *source;
};

struct pool              pf_src_tree_pl, pf_rule_pl, pf_queue_pl;
struct pool              pf_state_pl, pf_state_key_pl, pf_state_item_pl;
struct pool              pf_rule_item_pl, pf_sn_item_pl, pf_pktdelay_pl;
struct pool              pf_statelim_pl, pf_sourcelim_pl, pf_source_pl;
struct pool              pf_state_link_pl;

void                     pf_add_threshold(struct pf_threshold *);
int                      pf_check_threshold(struct pf_threshold *);
int                      pf_check_tcp_cksum(struct mbuf *, int, int,
                            sa_family_t);
__inline void            pf_cksum_fixup(u_int16_t *, u_int16_t, u_int16_t,
                            u_int8_t);
void                     pf_cksum_fixup_a(u_int16_t *, const struct pf_addr *,
                            const struct pf_addr *, sa_family_t, u_int8_t);
int                      pf_modulate_sack(struct pf_pdesc *,
                            struct pf_state_peer *);
int                      pf_icmp_mapping(struct pf_pdesc *, u_int8_t, int *,
                            u_int16_t *, u_int16_t *);
int                      pf_change_icmp_af(struct mbuf *, int,
                            struct pf_pdesc *, struct pf_pdesc *,
                            struct pf_addr *, struct pf_addr *, sa_family_t,
                            sa_family_t);
int                      pf_translate_a(struct pf_pdesc *, struct pf_addr *,
                            struct pf_addr *);
void                     pf_translate_icmp(struct pf_pdesc *, struct pf_addr *,
                            u_int16_t *, struct pf_addr *, struct pf_addr *,
                            u_int16_t);
int                      pf_translate_icmp_af(struct pf_pdesc*, int, void *);
void                     pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t, int,
                            sa_family_t, struct pf_rule *, u_int);
void                     pf_detach_state(struct pf_state *);
struct pf_state_key     *pf_state_key_attach(struct pf_state_key *,
                             struct pf_state *, int);
void                     pf_state_key_detach(struct pf_state *, int);
u_int32_t                pf_tcp_iss(struct pf_pdesc *);
void                     pf_rule_to_actions(struct pf_rule *,
                            struct pf_rule_actions *);
int                      pf_test_rule(struct pf_pdesc *, struct pf_rule **,
                            struct pf_state **, struct pf_rule **,
                            struct pf_ruleset **, u_short *);
static __inline int      pf_create_state(struct pf_pdesc *, struct pf_rule *,
                            struct pf_rule *, struct pf_rule *,
                            struct pf_state_key **, struct pf_state_key **,
                            int *, struct pf_state **, int,
                            struct pf_rule_slist *, struct pf_rule_actions *,
                            struct pf_src_node **, struct pf_test_ctx *);
static __inline int      pf_state_key_addr_setup(struct pf_pdesc *, void *,
                            int, struct pf_addr *, int, struct pf_addr *,
                            int, int);
int                      pf_state_key_setup(struct pf_pdesc *, struct
                            pf_state_key **, struct pf_state_key **, int);
int                      pf_tcp_track_full(struct pf_pdesc *,
                            struct pf_state **, u_short *, int *, int);
int                      pf_tcp_track_sloppy(struct pf_pdesc *,
                            struct pf_state **, u_short *);
static __inline int      pf_synproxy_ack(struct pf_rule *, struct pf_pdesc *,
                            struct pf_state **, struct pf_rule_actions *);
static __inline int      pf_synproxy(struct pf_pdesc *, struct pf_state **,
                            u_short *);
int                      pf_test_state(struct pf_pdesc *, struct pf_state **,
                            u_short *);
int                      pf_icmp_state_lookup(struct pf_pdesc *,
                            struct pf_state_key_cmp *, struct pf_state **,
                            u_int16_t, u_int16_t, int, int *, int, int);
int                      pf_test_state_icmp(struct pf_pdesc *,
                            struct pf_state **, u_short *);
u_int16_t                pf_calc_mss(struct pf_addr *, sa_family_t, int,
                            uint16_t, uint16_t);
static __inline int      pf_set_rt_ifp(struct pf_state *, struct pf_addr *,
                            sa_family_t, struct pf_src_node **);
struct pf_divert        *pf_get_divert(struct mbuf *);
int                      pf_walk_option(struct pf_pdesc *, struct ip *,
                            int, int, u_short *);
int                      pf_walk_header(struct pf_pdesc *, struct ip *,
                            u_short *);
int                      pf_walk_option6(struct pf_pdesc *, struct ip6_hdr *,
                            int, int, u_short *);
int                      pf_walk_header6(struct pf_pdesc *, struct ip6_hdr *,
                            u_short *);
void                     pf_print_state_parts(struct pf_state *,
                            struct pf_state_key *, struct pf_state_key *);
int                      pf_addr_wrap_neq(struct pf_addr_wrap *,
                            struct pf_addr_wrap *);
int                      pf_compare_state_keys(struct pf_state_key *,
                            struct pf_state_key *, struct pfi_kif *, u_int);
u_int16_t                pf_pkt_hash(sa_family_t, uint8_t,
                             const struct pf_addr *, const struct pf_addr *,
                             uint16_t, uint16_t);
int                      pf_find_state(struct pf_pdesc *,
                            struct pf_state_key_cmp *, struct pf_state **);
int                      pf_src_connlimit(struct pf_state **);
int                      pf_match_rcvif(struct mbuf *, struct pf_rule *);
enum pf_test_status      pf_match_rule(struct pf_test_ctx *,
                            struct pf_ruleset *);
void                     pf_counters_inc(int, struct pf_pdesc *,
                            struct pf_state *, struct pf_rule *,
                            struct pf_rule *);

int                      pf_state_insert(struct pfi_kif *,
                            struct pf_state_key **, struct pf_state_key **,
                            struct pf_state *);

int                      pf_state_key_isvalid(struct pf_state_key *);
struct pf_state_key     *pf_state_key_ref(struct pf_state_key *);
void                     pf_state_key_unref(struct pf_state_key *);
void                     pf_state_key_link_reverse(struct pf_state_key *,
                            struct pf_state_key *);
void                     pf_state_key_unlink_reverse(struct pf_state_key *);
void                     pf_state_key_link_inpcb(struct pf_state_key *,
                            struct inpcb *);
void                     pf_state_key_unlink_inpcb(struct pf_state_key *);
void                     pf_pktenqueue_delayed(void *);
int32_t                  pf_state_expires(const struct pf_state *, uint8_t);

#if NPFLOG > 0
void                     pf_log_matches(struct pf_pdesc *, struct pf_rule *,
                            struct pf_rule *, struct pf_ruleset *,
                            struct pf_rule_slist *);
#endif  /* NPFLOG > 0 */

extern struct pool pfr_ktable_pl;
extern struct pool pfr_kentry_pl;

struct pf_pool_limit pf_pool_limits[PF_LIMIT_MAX] = {
        { &pf_state_pl, PFSTATE_HIWAT, PFSTATE_HIWAT },
        { &pf_src_tree_pl, PFSNODE_HIWAT, PFSNODE_HIWAT },
        { &pf_frent_pl, PFFRAG_FRENT_HIWAT, PFFRAG_FRENT_HIWAT },
        { &pfr_ktable_pl, PFR_KTABLE_HIWAT, PFR_KTABLE_HIWAT },
        { &pfr_kentry_pl, PFR_KENTRY_HIWAT, PFR_KENTRY_HIWAT },
        { &pf_pktdelay_pl, PF_PKTDELAY_MAXPKTS, PF_PKTDELAY_MAXPKTS },
        { &pf_anchor_pl, PF_ANCHOR_HIWAT, PF_ANCHOR_HIWAT }
};

#define BOUND_IFACE(r, k) \
        ((r)->rule_flag & PFRULE_IFBOUND) ? (k) : pfi_all

#define STATE_INC_COUNTERS(s)                                   \
        do {                                                    \
                struct pf_rule_item *mrm;                       \
                s->rule.ptr->states_cur++;                      \
                s->rule.ptr->states_tot++;                      \
                if (s->anchor.ptr != NULL) {                    \
                        s->anchor.ptr->states_cur++;            \
                        s->anchor.ptr->states_tot++;            \
                }                                               \
                SLIST_FOREACH(mrm, &s->match_rules, entry)      \
                        mrm->r->states_cur++;                   \
        } while (0)

static __inline int pf_src_compare(struct pf_src_node *, struct pf_src_node *);
static inline int pf_state_compare_key(const struct pf_state_key *,
        const struct pf_state_key *);
static inline int pf_state_compare_id(const struct pf_state *,
        const struct pf_state *);
#ifdef INET6
static __inline void pf_cksum_uncover(u_int16_t *, u_int16_t, u_int8_t);
static __inline void pf_cksum_cover(u_int16_t *, u_int16_t, u_int8_t);
#endif /* INET6 */
static __inline void pf_set_protostate(struct pf_state *, int, u_int8_t);

static inline int
pf_statelim_id_cmp(const struct pf_statelim *a, const struct pf_statelim *b)
{
        if (a->pfstlim_id > b->pfstlim_id)
                return (1);
        if (a->pfstlim_id < b->pfstlim_id)
                return (-1);

        return (0);
}

RBT_GENERATE(pf_statelim_id_tree, pf_statelim, pfstlim_id_tree,
    pf_statelim_id_cmp);

static inline int
pf_statelim_nm_cmp(const struct pf_statelim *a, const struct pf_statelim *b)
{
        return (strncmp(a->pfstlim_nm, b->pfstlim_nm, sizeof(a->pfstlim_nm)));
}

RBT_GENERATE(pf_statelim_nm_tree, pf_statelim, pfstlim_nm_tree,
    pf_statelim_nm_cmp);

struct pf_statelim_id_tree pf_statelim_id_tree_active =
    RBT_INITIALIZER(pf_statelim_id_tree_active);
struct pf_statelim_list pf_statelim_list_active =
    TAILQ_HEAD_INITIALIZER(pf_statelim_list_active);

struct pf_statelim_id_tree pf_statelim_id_tree_inactive =
    RBT_INITIALIZER(pf_statelim_id_tree_inactive);
struct pf_statelim_nm_tree pf_statelim_nm_tree_inactive =
    RBT_INITIALIZER(pf_statelim_nm_tree_inactive);
struct pf_statelim_list pf_statelim_list_inactive =
    TAILQ_HEAD_INITIALIZER(pf_statelim_list_inactive);

static inline int
pf_sourcelim_id_cmp(const struct pf_sourcelim *a, const struct pf_sourcelim *b)
{
        if (a->pfsrlim_id > b->pfsrlim_id)
                return (1);
        if (a->pfsrlim_id < b->pfsrlim_id)
                return (-1);

        return (0);
}

RBT_GENERATE(pf_sourcelim_id_tree, pf_sourcelim, pfsrlim_id_tree,
    pf_sourcelim_id_cmp);

static inline int
pf_sourcelim_nm_cmp(const struct pf_sourcelim *a, const struct pf_sourcelim *b)
{
        return (strncmp(a->pfsrlim_nm, b->pfsrlim_nm, sizeof(a->pfsrlim_nm)));
}

RBT_GENERATE(pf_sourcelim_nm_tree, pf_sourcelim, pfsrlim_nm_tree,
    pf_sourcelim_nm_cmp);

static inline int
pf_source_cmp(const struct pf_source *a, const struct pf_source *b)
{
        if (a->pfsr_af > b->pfsr_af)
                return (1);
        if (a->pfsr_af < b->pfsr_af)
                return (-1);
        if (a->pfsr_rdomain > b->pfsr_rdomain)
                return (1);
        if (a->pfsr_rdomain < b->pfsr_rdomain)
                return (-1);

        return (pf_addr_compare(&a->pfsr_addr, &b->pfsr_addr, a->pfsr_af));
}

RBT_GENERATE(pf_source_tree, pf_source, pfsr_tree, pf_source_cmp);

static inline int
pf_source_ioc_cmp(const struct pf_source *a, const struct pf_source *b)
{
        size_t i;

        if (a->pfsr_af > b->pfsr_af)
                return (1);
        if (a->pfsr_af < b->pfsr_af)
                return (-1);
        if (a->pfsr_rdomain > b->pfsr_rdomain)
                return (1);
        if (a->pfsr_rdomain < b->pfsr_rdomain)
                return (-1);

        for (i = 0; i < nitems(a->pfsr_addr.addr32); i++) {
                uint32_t wa = ntohl(a->pfsr_addr.addr32[i]);
                uint32_t wb = ntohl(b->pfsr_addr.addr32[i]);

                if (wa > wb)
                        return (1);
                if (wa < wb)
                        return (-1);
        }

        return (0);
}

RBT_GENERATE(pf_source_ioc_tree, pf_source, pfsr_ioc_tree, pf_source_ioc_cmp);

struct pf_sourcelim_id_tree pf_sourcelim_id_tree_active =
    RBT_INITIALIZER(pf_sourcelim_id_tree_active);
struct pf_sourcelim_list pf_sourcelim_list_active =
    TAILQ_HEAD_INITIALIZER(pf_sourcelim_list_active);

struct pf_sourcelim_id_tree pf_sourcelim_id_tree_inactive =
    RBT_INITIALIZER(pf_sourcelim_id_tree_inactive);
struct pf_sourcelim_nm_tree pf_sourcelim_nm_tree_inactive =
    RBT_INITIALIZER(pf_sourcelim_nm_tree_inactive);
struct pf_sourcelim_list pf_sourcelim_list_inactive =
    TAILQ_HEAD_INITIALIZER(pf_sourcelim_list_inactive);

static inline struct pf_statelim *
pf_statelim_find(uint32_t id)
{
        struct pf_statelim key;

        /* only the id is used in cmp, so don't have to zero all the things */
        key.pfstlim_id = id;

        return (RBT_FIND(pf_statelim_id_tree,
            &pf_statelim_id_tree_active, &key));
}

static inline struct pf_sourcelim *
pf_sourcelim_find(uint32_t id)
{
        struct pf_sourcelim key;

        /* only the id is used in cmp, so don't have to zero all the things */
        key.pfsrlim_id = id;

        return (RBT_FIND(pf_sourcelim_id_tree,
            &pf_sourcelim_id_tree_active, &key));
}

struct pf_source_list pf_source_gc = TAILQ_HEAD_INITIALIZER(pf_source_gc);

static void
pf_source_purge(void)
{
        struct pf_source *sr, *nsr;
        time_t now = getuptime();

        TAILQ_FOREACH_SAFE(sr, &pf_source_gc, pfsr_empty_gc, nsr) {
                struct pf_sourcelim *srlim = sr->pfsr_parent;

                if (now <= sr->pfsr_empty_ts + srlim->pfsrlim_rate.seconds + 1)
                        continue;

                TAILQ_REMOVE(&pf_source_gc, sr, pfsr_empty_gc);

                RBT_REMOVE(pf_source_tree, &srlim->pfsrlim_sources, sr);
                RBT_REMOVE(pf_source_ioc_tree, &srlim->pfsrlim_ioc_sources, sr);
                srlim->pfsrlim_nsources--;

                pool_put(&pf_source_pl, sr);
        }
}

static void
pf_source_pfr_addr(struct pfr_addr *p, const struct pf_source *sr)
{
        struct pf_sourcelim *srlim = sr->pfsr_parent;

        memset(p, 0, sizeof(*p));

        p->pfra_af = sr->pfsr_af;
        switch (sr->pfsr_af) {
        case AF_INET:
                p->pfra_net = srlim->pfsrlim_ipv4_prefix;
                p->pfra_ip4addr = sr->pfsr_addr.v4;
                break;
#ifdef INET6
        case AF_INET6:
                p->pfra_net = srlim->pfsrlim_ipv6_prefix;
                p->pfra_ip6addr = sr->pfsr_addr.v6;
                break;
#endif /* INET6 */
        }
}

static void
pf_source_used(struct pf_source *sr)
{
        struct pf_sourcelim *srlim = sr->pfsr_parent;
        struct pfr_ktable *t;
        unsigned int used;

        used = sr->pfsr_inuse++;
        sr->pfsr_rate_ts += srlim->pfsrlim_rate_token;

        if (used == 0)
                TAILQ_REMOVE(&pf_source_gc, sr, pfsr_empty_gc);
        else if ((t = srlim->pfsrlim_overload.table) != NULL &&
            used >= srlim->pfsrlim_overload.hwm && !sr->pfsr_intable) {
                struct pfr_addr p;

                pf_source_pfr_addr(&p, sr);
                
                pfr_insert_kentry(t, &p, gettime());
                sr->pfsr_intable = 1;
        }
}

static void
pf_source_rele(struct pf_source *sr)
{
        struct pf_sourcelim *srlim = sr->pfsr_parent;
        struct pfr_ktable *t;
        unsigned int used;

        used = --sr->pfsr_inuse;

        t = srlim->pfsrlim_overload.table;
        if (t != NULL && sr->pfsr_intable &&
            used < srlim->pfsrlim_overload.lwm) {
                struct pfr_addr p;

                pf_source_pfr_addr(&p, sr);

                pfr_remove_kentry(t, &p);
                sr->pfsr_intable = 0;
        }

        if (used == 0) {
                TAILQ_INSERT_TAIL(&pf_source_gc, sr, pfsr_empty_gc);
                sr->pfsr_empty_ts = getuptime() + srlim->pfsrlim_rate.seconds;
        }
}

static inline void
pf_source_key(struct pf_sourcelim *srlim, struct pf_source *key,
    sa_family_t af, unsigned int rdomain, const struct pf_addr *addr)
{
        size_t i;

        /* only af+addr is used for lookup. */
        key->pfsr_af = af;
        key->pfsr_rdomain = rdomain;
        switch (af) {
        case AF_INET:
                key->pfsr_addr.addr32[0] =
                    srlim->pfsrlim_ipv4_mask.v4.s_addr &
                    addr->v4.s_addr;

                for (i = 1; i < nitems(key->pfsr_addr.addr32); i++)
                        key->pfsr_addr.addr32[i] = htonl(0);
                break;
#ifdef INET6
        case AF_INET6:
                for (i = 0; i < nitems(key->pfsr_addr.addr32); i++) {
                        key->pfsr_addr.addr32[i] =
                            srlim->pfsrlim_ipv6_mask.addr32[i] & 
                            addr->addr32[i];
                }
                break;
#endif
        default:
                unhandled_af(af);
                /* NOTREACHED */
        }
}

static inline struct pf_source *
pf_source_find(struct pf_sourcelim *srlim, const struct pf_source *key)
{
        return (RBT_FIND(pf_source_tree, &srlim->pfsrlim_sources, key));
}

struct pf_src_tree tree_src_tracking;

struct pf_state_tree_id tree_id;
struct pf_state_list pf_state_list = PF_STATE_LIST_INITIALIZER(pf_state_list);

RB_GENERATE(pf_src_tree, pf_src_node, entry, pf_src_compare);
RBT_GENERATE(pf_state_tree, pf_state_key, sk_entry, pf_state_compare_key);
RBT_GENERATE(pf_state_tree_id, pf_state, entry_id, pf_state_compare_id);

int
pf_addr_compare(const struct pf_addr *a, const struct pf_addr *b,
    sa_family_t af)
{
        switch (af) {
        case AF_INET:
                if (a->addr32[0] > b->addr32[0])
                        return (1);
                if (a->addr32[0] < b->addr32[0])
                        return (-1);
                break;
#ifdef INET6
        case AF_INET6:
                if (a->addr32[3] > b->addr32[3])
                        return (1);
                if (a->addr32[3] < b->addr32[3])
                        return (-1);
                if (a->addr32[2] > b->addr32[2])
                        return (1);
                if (a->addr32[2] < b->addr32[2])
                        return (-1);
                if (a->addr32[1] > b->addr32[1])
                        return (1);
                if (a->addr32[1] < b->addr32[1])
                        return (-1);
                if (a->addr32[0] > b->addr32[0])
                        return (1);
                if (a->addr32[0] < b->addr32[0])
                        return (-1);
                break;
#endif /* INET6 */
        }
        return (0);
}

static __inline int
pf_src_compare(struct pf_src_node *a, struct pf_src_node *b)
{
        int     diff;

        if (a->rule.ptr > b->rule.ptr)
                return (1);
        if (a->rule.ptr < b->rule.ptr)
                return (-1);
        if ((diff = a->type - b->type) != 0)
                return (diff);
        if ((diff = a->af - b->af) != 0)
                return (diff);
        if ((diff = pf_addr_compare(&a->addr, &b->addr, a->af)) != 0)
                return (diff);
        return (0);
}

static __inline void
pf_set_protostate(struct pf_state *st, int which, u_int8_t newstate)
{
        if (which == PF_PEER_DST || which == PF_PEER_BOTH)
                st->dst.state = newstate;
        if (which == PF_PEER_DST)
                return;

        if (st->src.state == newstate)
                return;
        if (st->creatorid == pf_status.hostid &&
            st->key[PF_SK_STACK]->proto == IPPROTO_TCP &&
            !(TCPS_HAVEESTABLISHED(st->src.state) ||
            st->src.state == TCPS_CLOSED) &&
            (TCPS_HAVEESTABLISHED(newstate) || newstate == TCPS_CLOSED))
                atomic_dec_int(&pf_status.states_halfopen);

        st->src.state = newstate;
}

void
pf_addrcpy(struct pf_addr *dst, struct pf_addr *src, sa_family_t af)
{
        switch (af) {
        case AF_INET:
                dst->addr32[0] = src->addr32[0];
                break;
#ifdef INET6
        case AF_INET6:
                dst->addr32[0] = src->addr32[0];
                dst->addr32[1] = src->addr32[1];
                dst->addr32[2] = src->addr32[2];
                dst->addr32[3] = src->addr32[3];
                break;
#endif /* INET6 */
        default:
                unhandled_af(af);
        }
}

void
pf_init_threshold(struct pf_threshold *threshold,
    u_int32_t limit, u_int32_t seconds)
{
        threshold->limit = limit * PF_THRESHOLD_MULT;
        threshold->seconds = seconds;
        threshold->count = 0;
        threshold->last = getuptime();
}

void
pf_add_threshold(struct pf_threshold *threshold)
{
        u_int32_t t = getuptime(), diff = t - threshold->last;

        if (diff >= threshold->seconds)
                threshold->count = 0;
        else
                threshold->count -= threshold->count * diff /
                    threshold->seconds;
        threshold->count += PF_THRESHOLD_MULT;
        threshold->last = t;
}

int
pf_check_threshold(struct pf_threshold *threshold)
{
        return (threshold->count > threshold->limit);
}

void
pf_state_list_insert(struct pf_state_list *pfs, struct pf_state *st)
{
        /*
         * we can always put states on the end of the list.
         *
         * things reading the list should take a read lock, then
         * the mutex, get the head and tail pointers, release the
         * mutex, and then they can iterate between the head and tail.
         */

        pf_state_ref(st); /* get a ref for the list */

        mtx_enter(&pfs->pfs_mtx);
        TAILQ_INSERT_TAIL(&pfs->pfs_list, st, entry_list);
        mtx_leave(&pfs->pfs_mtx);
}

void
pf_state_list_remove(struct pf_state_list *pfs, struct pf_state *st)
{
        /* states can only be removed when the write lock is held */
        rw_assert_wrlock(&pfs->pfs_rwl);

        mtx_enter(&pfs->pfs_mtx);
        TAILQ_REMOVE(&pfs->pfs_list, st, entry_list);
        mtx_leave(&pfs->pfs_mtx);

        pf_state_unref(st); /* list no longer references the state */
}

void
pf_update_state_timeout(struct pf_state *st, int to)
{
        mtx_enter(&st->mtx);
        if (st->timeout != PFTM_UNLINKED)
                st->timeout = to;
        mtx_leave(&st->mtx);
}

int
pf_src_connlimit(struct pf_state **stp)
{
        int                      bad = 0;
        struct pf_src_node      *sn;

        if ((sn = pf_get_src_node((*stp), PF_SN_NONE)) == NULL)
                return (0);

        sn->conn++;
        (*stp)->src.tcp_est = 1;
        pf_add_threshold(&sn->conn_rate);

        if ((*stp)->rule.ptr->max_src_conn &&
            (*stp)->rule.ptr->max_src_conn < sn->conn) {
                pf_status.lcounters[LCNT_SRCCONN]++;
                bad++;
        }

        if ((*stp)->rule.ptr->max_src_conn_rate.limit &&
            pf_check_threshold(&sn->conn_rate)) {
                pf_status.lcounters[LCNT_SRCCONNRATE]++;
                bad++;
        }

        if (!bad)
                return (0);

        if ((*stp)->rule.ptr->overload_tbl) {
                struct pfr_addr p;
                u_int32_t       killed = 0;

                pf_status.lcounters[LCNT_OVERLOAD_TABLE]++;
                if (pf_status.debug >= LOG_NOTICE) {
                        log(LOG_NOTICE,
                            "pf: pf_src_connlimit: blocking address ");
                        pf_print_host(&sn->addr, 0,
                            (*stp)->key[PF_SK_WIRE]->af);
                }

                memset(&p, 0, sizeof(p));
                p.pfra_af = (*stp)->key[PF_SK_WIRE]->af;
                switch ((*stp)->key[PF_SK_WIRE]->af) {
                case AF_INET:
                        p.pfra_net = 32;
                        p.pfra_ip4addr = sn->addr.v4;
                        break;
#ifdef INET6
                case AF_INET6:
                        p.pfra_net = 128;
                        p.pfra_ip6addr = sn->addr.v6;
                        break;
#endif /* INET6 */
                }

                pfr_insert_kentry((*stp)->rule.ptr->overload_tbl,
                    &p, gettime());

                /* kill existing states if that's required. */
                if ((*stp)->rule.ptr->flush) {
                        struct pf_state_key *sk;
                        struct pf_state *st;

                        pf_status.lcounters[LCNT_OVERLOAD_FLUSH]++;
                        RBT_FOREACH(st, pf_state_tree_id, &tree_id) {
                                sk = st->key[PF_SK_WIRE];
                                /*
                                 * Kill states from this source.  (Only those
                                 * from the same rule if PF_FLUSH_GLOBAL is not
                                 * set)
                                 */
                                if (sk->af ==
                                    (*stp)->key[PF_SK_WIRE]->af &&
                                    (((*stp)->direction == PF_OUT &&
                                    PF_AEQ(&sn->addr, &sk->addr[1], sk->af)) ||
                                    ((*stp)->direction == PF_IN &&
                                    PF_AEQ(&sn->addr, &sk->addr[0], sk->af))) &&
                                    ((*stp)->rule.ptr->flush &
                                    PF_FLUSH_GLOBAL ||
                                    (*stp)->rule.ptr == st->rule.ptr)) {
                                        pf_update_state_timeout(st, PFTM_PURGE);
                                        pf_set_protostate(st, PF_PEER_BOTH,
                                            TCPS_CLOSED);
                                        killed++;
                                }
                        }
                        if (pf_status.debug >= LOG_NOTICE)
                                addlog(", %u states killed", killed);
                }
                if (pf_status.debug >= LOG_NOTICE)
                        addlog("\n");
        }

        /* kill this state */
        pf_update_state_timeout(*stp, PFTM_PURGE);
        pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_CLOSED);
        return (1);
}

int
pf_insert_src_node(struct pf_src_node **sn, struct pf_rule *rule,
    enum pf_sn_types type, sa_family_t af, struct pf_addr *src,
    struct pf_addr *raddr, struct pfi_kif *kif)
{
        struct pf_src_node      k;

        if (*sn == NULL) {
                k.af = af;
                k.type = type;
                pf_addrcpy(&k.addr, src, af);
                k.rule.ptr = rule;
                pf_status.scounters[SCNT_SRC_NODE_SEARCH]++;
                *sn = RB_FIND(pf_src_tree, &tree_src_tracking, &k);
        }
        if (*sn == NULL) {
                if (!rule->max_src_nodes ||
                    rule->src_nodes < rule->max_src_nodes)
                        (*sn) = pool_get(&pf_src_tree_pl, PR_NOWAIT | PR_ZERO);
                else
                        pf_status.lcounters[LCNT_SRCNODES]++;
                if ((*sn) == NULL)
                        return (-1);

                pf_init_threshold(&(*sn)->conn_rate,
                    rule->max_src_conn_rate.limit,
                    rule->max_src_conn_rate.seconds);

                (*sn)->type = type;
                (*sn)->af = af;
                (*sn)->rule.ptr = rule;
                pf_addrcpy(&(*sn)->addr, src, af);
                if (raddr)
                        pf_addrcpy(&(*sn)->raddr, raddr, af);
                if (RB_INSERT(pf_src_tree,
                    &tree_src_tracking, *sn) != NULL) {
                        if (pf_status.debug >= LOG_NOTICE) {
                                log(LOG_NOTICE,
                                    "pf: src_tree insert failed: ");
                                pf_print_host(&(*sn)->addr, 0, af);
                                addlog("\n");
                        }
                        pool_put(&pf_src_tree_pl, *sn);
                        return (-1);
                }
                (*sn)->creation = getuptime();
                (*sn)->rule.ptr->src_nodes++;
                if (kif != NULL) {
                        (*sn)->kif = kif;
                        pfi_kif_ref(kif, PFI_KIF_REF_SRCNODE);
                }
                pf_status.scounters[SCNT_SRC_NODE_INSERT]++;
                pf_status.src_nodes++;
        } else {
                if (rule->max_src_states &&
                    (*sn)->states >= rule->max_src_states) {
                        pf_status.lcounters[LCNT_SRCSTATES]++;
                        return (-1);
                }
        }
        return (0);
}

void
pf_remove_src_node(struct pf_src_node *sn)
{
        if (sn->states > 0 || sn->expire > getuptime())
                return;

        sn->rule.ptr->src_nodes--;
        if (sn->rule.ptr->states_cur == 0 &&
            sn->rule.ptr->src_nodes == 0)
                pf_rm_rule(NULL, sn->rule.ptr);
        RB_REMOVE(pf_src_tree, &tree_src_tracking, sn);
        pf_status.scounters[SCNT_SRC_NODE_REMOVALS]++;
        pf_status.src_nodes--;
        pfi_kif_unref(sn->kif, PFI_KIF_REF_SRCNODE);
        pool_put(&pf_src_tree_pl, sn);
}

struct pf_src_node *
pf_get_src_node(struct pf_state *st, enum pf_sn_types type)
{
        struct pf_sn_item       *sni;

        SLIST_FOREACH(sni, &st->src_nodes, next)
                if (sni->sn->type == type)
                        return (sni->sn);
        return (NULL);
}

void
pf_state_rm_src_node(struct pf_state *st, struct pf_src_node *sn)
{
        struct pf_sn_item       *sni, *snin, *snip = NULL;

        for (sni = SLIST_FIRST(&st->src_nodes); sni; sni = snin) {
                snin = SLIST_NEXT(sni, next);
                if (sni->sn == sn) {
                        if (snip)
                                SLIST_REMOVE_AFTER(snip, next);
                        else
                                SLIST_REMOVE_HEAD(&st->src_nodes, next);
                        pool_put(&pf_sn_item_pl, sni);
                        sni = NULL;
                        sn->states--;
                }
                if (sni != NULL)
                        snip = sni;
        }
}

/* state table stuff */

static inline int
pf_state_compare_key(const struct pf_state_key *a,
    const struct pf_state_key *b)
{
        int     diff;

        if ((diff = a->hash - b->hash) != 0)
                return (diff);
        if ((diff = a->proto - b->proto) != 0)
                return (diff);
        if ((diff = a->af - b->af) != 0)
                return (diff);
        if ((diff = pf_addr_compare(&a->addr[0], &b->addr[0], a->af)) != 0)
                return (diff);
        if ((diff = pf_addr_compare(&a->addr[1], &b->addr[1], a->af)) != 0)
                return (diff);
        if ((diff = a->port[0] - b->port[0]) != 0)
                return (diff);
        if ((diff = a->port[1] - b->port[1]) != 0)
                return (diff);
        if ((diff = a->rdomain - b->rdomain) != 0)
                return (diff);
        return (0);
}

static inline int
pf_state_compare_id(const struct pf_state *a, const struct pf_state *b)
{
        if (a->id > b->id)
                return (1);
        if (a->id < b->id)
                return (-1);
        if (a->creatorid > b->creatorid)
                return (1);
        if (a->creatorid < b->creatorid)
                return (-1);

        return (0);
}

/*
 * on failure, pf_state_key_attach() releases the pf_state_key
 * reference and returns NULL.
 */
struct pf_state_key *
pf_state_key_attach(struct pf_state_key *sk, struct pf_state *st, int idx)
{
        struct pf_state_item    *si;
        struct pf_state_key     *cur;
        struct pf_state         *oldst = NULL;

        PF_ASSERT_LOCKED();

        KASSERT(st->key[idx] == NULL);
        sk->sk_removed = 0;
        cur = RBT_INSERT(pf_state_tree, &pf_statetbl, sk);
        if (cur != NULL) {
                sk->sk_removed = 1;
                /* key exists. check for same kif, if none, add to key */
                TAILQ_FOREACH(si, &cur->sk_states, si_entry) {
                        struct pf_state *sist = si->si_st;
                        if (sist->kif == st->kif &&
                            ((sist->key[PF_SK_WIRE]->af == sk->af &&
                             sist->direction == st->direction) ||
                            (sist->key[PF_SK_WIRE]->af !=
                             sist->key[PF_SK_STACK]->af &&
                             sk->af == sist->key[PF_SK_STACK]->af &&
                             sist->direction != st->direction))) {
                                int reuse = 0;

                                if (sk->proto == IPPROTO_TCP &&
                                    sist->src.state >= TCPS_FIN_WAIT_2 &&
                                    sist->dst.state >= TCPS_FIN_WAIT_2)
                                        reuse = 1;
                                if (pf_status.debug >= LOG_NOTICE) {
                                        log(LOG_NOTICE,
                                            "pf: %s key attach %s on %s: ",
                                            (idx == PF_SK_WIRE) ?
                                            "wire" : "stack",
                                            reuse ? "reuse" : "failed",
                                            st->kif->pfik_name);
                                        pf_print_state_parts(st,
                                            (idx == PF_SK_WIRE) ?  sk : NULL,
                                            (idx == PF_SK_STACK) ?  sk : NULL);
                                        addlog(", existing: ");
                                        pf_print_state_parts(sist,
                                            (idx == PF_SK_WIRE) ?  sk : NULL,
                                            (idx == PF_SK_STACK) ?  sk : NULL);
                                        addlog("\n");
                                }
                                if (reuse) {
                                        pf_set_protostate(sist, PF_PEER_BOTH,
                                            TCPS_CLOSED);
                                        /* remove late or sks can go away */
                                        oldst = sist;
                                } else {
                                        pf_state_key_unref(sk);
                                        return (NULL);  /* collision! */
                                }
                        }
                }

                /* reuse the existing state key */
                pf_state_key_unref(sk);
                sk = cur;
        }

        if ((si = pool_get(&pf_state_item_pl, PR_NOWAIT)) == NULL) {
                if (TAILQ_EMPTY(&sk->sk_states)) {
                        KASSERT(cur == NULL);
                        RBT_REMOVE(pf_state_tree, &pf_statetbl, sk);
                        sk->sk_removed = 1;
                        pf_state_key_unref(sk);
                }

                return (NULL);
        }

        st->key[idx] = pf_state_key_ref(sk); /* give a ref to state */
        si->si_st = pf_state_ref(st);

        /* list is sorted, if-bound states before floating */
        if (st->kif == pfi_all)
                TAILQ_INSERT_TAIL(&sk->sk_states, si, si_entry);
        else
                TAILQ_INSERT_HEAD(&sk->sk_states, si, si_entry);

        if (oldst)
                pf_remove_state(oldst);

        /* caller owns the pf_state ref, which owns a pf_state_key ref now */
        return (sk);
}

void
pf_detach_state(struct pf_state *st)
{
        KASSERT(st->key[PF_SK_WIRE] != NULL);
        pf_state_key_detach(st, PF_SK_WIRE);

        KASSERT(st->key[PF_SK_STACK] != NULL);
        if (st->key[PF_SK_STACK] != st->key[PF_SK_WIRE])
                pf_state_key_detach(st, PF_SK_STACK);
}

void
pf_state_key_detach(struct pf_state *st, int idx)
{
        struct pf_state_item    *si;
        struct pf_state_key     *sk;

        PF_ASSERT_LOCKED();

        sk = st->key[idx];
        if (sk == NULL)
                return;

        TAILQ_FOREACH(si, &sk->sk_states, si_entry) {
                if (si->si_st == st)
                        break;
        }
        if (si == NULL)
                return;

        TAILQ_REMOVE(&sk->sk_states, si, si_entry);
        pool_put(&pf_state_item_pl, si);

        if (TAILQ_EMPTY(&sk->sk_states)) {
                RBT_REMOVE(pf_state_tree, &pf_statetbl, sk);
                sk->sk_removed = 1;
                pf_state_key_unlink_reverse(sk);
                pf_state_key_unlink_inpcb(sk);
                pf_state_key_unref(sk);
        }

        pf_state_unref(st);
}

struct pf_state_key *
pf_alloc_state_key(int pool_flags)
{
        struct pf_state_key     *sk;

        if ((sk = pool_get(&pf_state_key_pl, pool_flags)) == NULL)
                return (NULL);

        PF_REF_INIT(sk->sk_refcnt);
        TAILQ_INIT(&sk->sk_states);
        sk->sk_removed = 1;

        return (sk);
}

static __inline int
pf_state_key_addr_setup(struct pf_pdesc *pd, void *arg, int sidx,
    struct pf_addr *saddr, int didx, struct pf_addr *daddr, int af, int multi)
{
        struct pf_state_key_cmp *key = arg;
#ifdef INET6
        struct pf_addr *target;

        if (af == AF_INET || pd->proto != IPPROTO_ICMPV6)
                goto copy;

        switch (pd->hdr.icmp6.icmp6_type) {
        case ND_NEIGHBOR_SOLICIT:
                if (multi)
                        return (-1);
                target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target;
                daddr = target;
                break;
        case ND_NEIGHBOR_ADVERT:
                if (multi)
                        return (-1);
                target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target;
                saddr = target;
                if (IN6_IS_ADDR_MULTICAST(&pd->dst->v6)) {
                        key->addr[didx].addr32[0] = 0;
                        key->addr[didx].addr32[1] = 0;
                        key->addr[didx].addr32[2] = 0;
                        key->addr[didx].addr32[3] = 0;
                        daddr = NULL; /* overwritten */
                }
                break;
        default:
                if (multi) {
                        key->addr[sidx].addr32[0] = __IPV6_ADDR_INT32_MLL;
                        key->addr[sidx].addr32[1] = 0;
                        key->addr[sidx].addr32[2] = 0;
                        key->addr[sidx].addr32[3] = __IPV6_ADDR_INT32_ONE;
                        saddr = NULL; /* overwritten */
                }
        }
 copy:
#endif  /* INET6 */
        if (saddr)
                pf_addrcpy(&key->addr[sidx], saddr, af);
        if (daddr)
                pf_addrcpy(&key->addr[didx], daddr, af);

        return (0);
}

int
pf_state_key_setup(struct pf_pdesc *pd, struct pf_state_key **skw,
    struct pf_state_key **sks, int rtableid)
{
        /* if returning error we MUST pool_put state keys ourselves */
        struct pf_state_key *sk1, *sk2;
        u_int wrdom = pd->rdomain;
        int afto = pd->af != pd->naf;

        if ((sk1 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL)
                return (ENOMEM);

        pf_state_key_addr_setup(pd, sk1, pd->sidx, pd->src, pd->didx, pd->dst,
            pd->af, 0);
        sk1->port[pd->sidx] = pd->osport;
        sk1->port[pd->didx] = pd->odport;
        sk1->proto = pd->proto;
        sk1->af = pd->af;
        sk1->rdomain = pd->rdomain;
        sk1->hash = pf_pkt_hash(sk1->af, sk1->proto,
            &sk1->addr[0], &sk1->addr[1], sk1->port[0], sk1->port[1]);
        if (rtableid >= 0)
                wrdom = rtable_l2(rtableid);

        if (PF_ANEQ(&pd->nsaddr, pd->src, pd->af) ||
            PF_ANEQ(&pd->ndaddr, pd->dst, pd->af) ||
            pd->nsport != pd->osport || pd->ndport != pd->odport ||
            wrdom != pd->rdomain || afto) {     /* NAT/NAT64 */
                if ((sk2 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) {
                        pf_state_key_unref(sk1);
                        return (ENOMEM);
                }
                pf_state_key_addr_setup(pd, sk2, afto ? pd->didx : pd->sidx,
                    &pd->nsaddr, afto ? pd->sidx : pd->didx, &pd->ndaddr,
                    pd->naf, 0);
                sk2->port[afto ? pd->didx : pd->sidx] = pd->nsport;
                sk2->port[afto ? pd->sidx : pd->didx] = pd->ndport;
                if (afto) {
                        switch (pd->proto) {
                        case IPPROTO_ICMP:
                                sk2->proto = IPPROTO_ICMPV6;
                                break;
                        case IPPROTO_ICMPV6:
                                sk2->proto = IPPROTO_ICMP;
                                break;
                        default:
                                sk2->proto = pd->proto;
                        }
                } else
                        sk2->proto = pd->proto;
                sk2->af = pd->naf;
                sk2->rdomain = wrdom;
                sk2->hash = pf_pkt_hash(sk2->af, sk2->proto,
                    &sk2->addr[0], &sk2->addr[1], sk2->port[0], sk2->port[1]);
        } else
                sk2 = pf_state_key_ref(sk1);

        if (pd->dir == PF_IN) {
                *skw = sk1;
                *sks = sk2;
        } else {
                *sks = sk1;
                *skw = sk2;
        }

        if (pf_status.debug >= LOG_DEBUG) {
                log(LOG_DEBUG, "pf: key setup: ");
                pf_print_state_parts(NULL, *skw, *sks);
                addlog("\n");
        }

        return (0);
}

/*
 * pf_state_insert() does the following:
 * - links the pf_state up with pf_state_key(s).
 * - inserts the pf_state_keys into pf_state_tree.
 * - inserts the pf_state into the into pf_state_tree_id.
 * - tells pfsync about the state.
 *
 * pf_state_insert() owns the references to the pf_state_key structs
 * it is given. on failure to insert, these references are released.
 * on success, the caller owns a pf_state reference that allows it
 * to access the state keys.
 */

int
pf_state_insert(struct pfi_kif *kif, struct pf_state_key **skwp,
    struct pf_state_key **sksp, struct pf_state *st)
{
        struct pf_state_key *skw = *skwp;
        struct pf_state_key *sks = *sksp;
        int same = (skw == sks);

        PF_ASSERT_LOCKED();

        st->kif = kif;
        PF_STATE_ENTER_WRITE();

        skw = pf_state_key_attach(skw, st, PF_SK_WIRE);
        if (skw == NULL) {
                pf_state_key_unref(sks);
                PF_STATE_EXIT_WRITE();
                return (-1);
        }

        if (same) {
                /* pf_state_key_attach might have swapped skw */
                if (skw != sks) {
                        pf_state_key_unref(sks);
                        sks = pf_state_key_ref(skw);
                }
                st->key[PF_SK_STACK] = sks;
        } else if (pf_state_key_attach(sks, st, PF_SK_STACK) == NULL) {
                pf_state_key_detach(st, PF_SK_WIRE);
                PF_STATE_EXIT_WRITE();
                return (-1);
        }

        if (st->id == 0 && st->creatorid == 0) {
                st->id = htobe64(pf_status.stateid++);
                st->creatorid = pf_status.hostid;
        }
        if (RBT_INSERT(pf_state_tree_id, &tree_id, st) != NULL) {
                if (pf_status.debug >= LOG_NOTICE) {
                        log(LOG_NOTICE, "pf: state insert failed: "
                            "id: %016llx creatorid: %08x",
                            betoh64(st->id), ntohl(st->creatorid));
                        addlog("\n");
                }
                pf_detach_state(st);
                PF_STATE_EXIT_WRITE();
                return (-1);
        }
        pf_state_list_insert(&pf_state_list, st);
        counters_inc(pf_status_fcounters, FCNT_STATE_INSERT);
        pf_status.states++;
        pfi_kif_ref(kif, PFI_KIF_REF_STATE);
        PF_STATE_EXIT_WRITE();

#if NPFSYNC > 0
        pfsync_insert_state(st);
#endif  /* NPFSYNC > 0 */

        *skwp = skw;
        *sksp = sks;

        return (0);
}

struct pf_state *
pf_find_state_byid(struct pf_state_cmp *key)
{
        counters_inc(pf_status_fcounters, FCNT_STATE_SEARCH);

        return (RBT_FIND(pf_state_tree_id, &tree_id, (struct pf_state *)key));
}

int
pf_compare_state_keys(struct pf_state_key *a, struct pf_state_key *b,
    struct pfi_kif *kif, u_int dir)
{
        /* a (from hdr) and b (new) must be exact opposites of each other */
        if (a->af == b->af && a->proto == b->proto &&
            PF_AEQ(&a->addr[0], &b->addr[1], a->af) &&
            PF_AEQ(&a->addr[1], &b->addr[0], a->af) &&
            a->port[0] == b->port[1] &&
            a->port[1] == b->port[0] && a->rdomain == b->rdomain)
                return (0);
        else {
                /* mismatch. must not happen. */
                if (pf_status.debug >= LOG_ERR) {
                        log(LOG_ERR,
                            "pf: state key linking mismatch! dir=%s, "
                            "if=%s, stored af=%u, a0: ",
                            dir == PF_OUT ? "OUT" : "IN",
                            kif->pfik_name, a->af);
                        pf_print_host(&a->addr[0], a->port[0], a->af);
                        addlog(", a1: ");
                        pf_print_host(&a->addr[1], a->port[1], a->af);
                        addlog(", proto=%u", a->proto);
                        addlog(", found af=%u, a0: ", b->af);
                        pf_print_host(&b->addr[0], b->port[0], b->af);
                        addlog(", a1: ");
                        pf_print_host(&b->addr[1], b->port[1], b->af);
                        addlog(", proto=%u", b->proto);
                        addlog("\n");
                }
                return (-1);
        }
}

int
pf_find_state(struct pf_pdesc *pd, struct pf_state_key_cmp *key,
    struct pf_state **stp)
{
        struct pf_state_key     *sk, *pkt_sk;
        struct pf_state_item    *si;
        struct pf_state         *st = NULL;
        int                      didx;

        counters_inc(pf_status_fcounters, FCNT_STATE_SEARCH);
        if (pf_status.debug >= LOG_DEBUG) {
                log(LOG_DEBUG, "pf: key search, %s on %s: ",
                    pd->dir == PF_OUT ? "out" : "in", pd->kif->pfik_name);
                pf_print_state_parts(NULL, (struct pf_state_key *)key, NULL);
                addlog("\n");
        }

        pkt_sk = NULL;
        sk = NULL;
        if (pd->dir == PF_OUT) {
                /* first if block deals with outbound forwarded packet */
                pkt_sk = pd->m->m_pkthdr.pf.statekey;

                if (!pf_state_key_isvalid(pkt_sk)) {
                        pf_mbuf_unlink_state_key(pd->m);
                        pkt_sk = NULL;
                }

                if (pkt_sk && pf_state_key_isvalid(pkt_sk->sk_reverse))
                        sk = pkt_sk->sk_reverse;

                if (pkt_sk == NULL) {
                        struct inpcb *inp = pd->m->m_pkthdr.pf.inp;

                        /* here we deal with local outbound packet */
                        if (inp != NULL) {
                                struct pf_state_key     *inp_sk;

                                mtx_enter(&pf_inp_mtx);
                                inp_sk = inp->inp_pf_sk;
                                if (pf_state_key_isvalid(inp_sk)) {
                                        sk = inp_sk;
                                        mtx_leave(&pf_inp_mtx);
                                } else if (inp_sk != NULL) {
                                        KASSERT(inp_sk->sk_inp == inp);
                                        inp_sk->sk_inp = NULL;
                                        inp->inp_pf_sk = NULL;
                                        mtx_leave(&pf_inp_mtx);

                                        pf_state_key_unref(inp_sk);
                                        in_pcbunref(inp);
                                } else
                                        mtx_leave(&pf_inp_mtx);
                        }
                }
        }

        if (sk == NULL) {
                if ((sk = RBT_FIND(pf_state_tree, &pf_statetbl,
                    (struct pf_state_key *)key)) == NULL)
                        return (PF_DROP);
                if (pd->dir == PF_OUT && pkt_sk &&
                    pf_compare_state_keys(pkt_sk, sk, pd->kif, pd->dir) == 0)
                        pf_state_key_link_reverse(sk, pkt_sk);
                else if (pd->dir == PF_OUT)
                        pf_state_key_link_inpcb(sk, pd->m->m_pkthdr.pf.inp);
        }

        /* remove firewall data from outbound packet */
        if (pd->dir == PF_OUT)
                pf_pkt_addr_changed(pd->m);

        didx = (pd->dir == PF_IN) ? PF_SK_WIRE : PF_SK_STACK;

        /* list is sorted, if-bound states before floating ones */
        TAILQ_FOREACH(si, &sk->sk_states, si_entry) {
                struct pf_state *sist = si->si_st;
                if (sist->timeout == PFTM_PURGE)
                        continue;
                if (sist->kif != pfi_all && sist->kif != pd->kif)
                        continue;

                /* af-to needs to handled specially */
                if (sist->key[PF_SK_WIRE]->af == sist->key[PF_SK_STACK]->af) {
                        if (sk != sist->key[didx])
                                continue;

                /* af-to case */
                } else {
                        /*
                         * af-to creates state for incoming (PF_IN)
                         * connections, and then forces forwarding without
                         * creating an outgoing state. this means the one
                         * state covers both sides of the stack, so should
                         * only match when pd dir is PF_IN.
                         */
                        if (pd->dir != PF_IN)
                                continue;

                        /* one of the st keys has to be sk */
                }

                st = sist;
                break;
        }

        if (st == NULL)
                return (PF_DROP);
        if (ISSET(st->state_flags, PFSTATE_INP_UNLINKED))
                return (PF_DROP);

        if (st->rule.ptr->pktrate.limit && pd->dir == st->direction) {
                pf_add_threshold(&st->rule.ptr->pktrate);
                if (pf_check_threshold(&st->rule.ptr->pktrate))
                        return (PF_DROP);
        }

        *stp = st;

        return (PF_MATCH);
}

struct pf_state *
pf_find_state_all(struct pf_state_key_cmp *key, u_int dir, int *more)
{
        struct pf_state_key     *sk;
        struct pf_state_item    *si, *ret = NULL;

        counters_inc(pf_status_fcounters, FCNT_STATE_SEARCH);

        sk = RBT_FIND(pf_state_tree, &pf_statetbl, (struct pf_state_key *)key);

        if (sk != NULL) {
                TAILQ_FOREACH(si, &sk->sk_states, si_entry) {
                        struct pf_state *sist = si->si_st;
                        if (dir == PF_INOUT ||
                            (sk == (dir == PF_IN ? sist->key[PF_SK_WIRE] :
                            sist->key[PF_SK_STACK]))) {
                                if (more == NULL)
                                        return (sist);

                                if (ret)
                                        (*more)++;
                                else
                                        ret = si;
                        }
                }
        }
        return (ret ? ret->si_st : NULL);
}

void
pf_state_peer_hton(const struct pf_state_peer *s, struct pfsync_state_peer *d)
{
        d->seqlo = htonl(s->seqlo);
        d->seqhi = htonl(s->seqhi);
        d->seqdiff = htonl(s->seqdiff);
        d->max_win = htons(s->max_win);
        d->mss = htons(s->mss);
        d->state = s->state;
        d->wscale = s->wscale;
        if (s->scrub) {
                d->scrub.pfss_flags =
                    htons(s->scrub->pfss_flags & PFSS_TIMESTAMP);
                d->scrub.pfss_ttl = (s)->scrub->pfss_ttl;
                d->scrub.pfss_ts_mod = htonl((s)->scrub->pfss_ts_mod);
                d->scrub.scrub_flag = PFSYNC_SCRUB_FLAG_VALID;
        }
}

void
pf_state_peer_ntoh(const struct pfsync_state_peer *s, struct pf_state_peer *d)
{
        d->seqlo = ntohl(s->seqlo);
        d->seqhi = ntohl(s->seqhi);
        d->seqdiff = ntohl(s->seqdiff);
        d->max_win = ntohs(s->max_win);
        d->mss = ntohs(s->mss);
        d->state = s->state;
        d->wscale = s->wscale;
        if (s->scrub.scrub_flag == PFSYNC_SCRUB_FLAG_VALID &&
            d->scrub != NULL) {
                d->scrub->pfss_flags =
                    ntohs(s->scrub.pfss_flags) & PFSS_TIMESTAMP;
                d->scrub->pfss_ttl = s->scrub.pfss_ttl;
                d->scrub->pfss_ts_mod = ntohl(s->scrub.pfss_ts_mod);
        }
}

void
pf_state_export(struct pfsync_state *sp, struct pf_state *st)
{
        int32_t expire;

        memset(sp, 0, sizeof(struct pfsync_state));

        /* copy from state key */
        sp->key[PF_SK_WIRE].addr[0] = st->key[PF_SK_WIRE]->addr[0];
        sp->key[PF_SK_WIRE].addr[1] = st->key[PF_SK_WIRE]->addr[1];
        sp->key[PF_SK_WIRE].port[0] = st->key[PF_SK_WIRE]->port[0];
        sp->key[PF_SK_WIRE].port[1] = st->key[PF_SK_WIRE]->port[1];
        sp->key[PF_SK_WIRE].rdomain = htons(st->key[PF_SK_WIRE]->rdomain);
        sp->key[PF_SK_WIRE].af = st->key[PF_SK_WIRE]->af;
        sp->key[PF_SK_STACK].addr[0] = st->key[PF_SK_STACK]->addr[0];
        sp->key[PF_SK_STACK].addr[1] = st->key[PF_SK_STACK]->addr[1];
        sp->key[PF_SK_STACK].port[0] = st->key[PF_SK_STACK]->port[0];
        sp->key[PF_SK_STACK].port[1] = st->key[PF_SK_STACK]->port[1];
        sp->key[PF_SK_STACK].rdomain = htons(st->key[PF_SK_STACK]->rdomain);
        sp->key[PF_SK_STACK].af = st->key[PF_SK_STACK]->af;
        sp->rtableid[PF_SK_WIRE] = htonl(st->rtableid[PF_SK_WIRE]);
        sp->rtableid[PF_SK_STACK] = htonl(st->rtableid[PF_SK_STACK]);
        sp->proto = st->key[PF_SK_WIRE]->proto;
        sp->af = st->key[PF_SK_WIRE]->af;

        /* copy from state */
        strlcpy(sp->ifname, st->kif->pfik_name, sizeof(sp->ifname));
        sp->rt = st->rt;
        sp->rt_addr = st->rt_addr;
        sp->creation = htonl(getuptime() - st->creation);
        expire = pf_state_expires(st, st->timeout);
        if (expire <= getuptime())
                sp->expire = htonl(0);
        else
                sp->expire = htonl(expire - getuptime());

        sp->direction = st->direction;
#if NPFLOG > 0
        sp->log = st->log;
#endif  /* NPFLOG > 0 */
        sp->timeout = st->timeout;
        sp->state_flags = htons(st->state_flags);
        if (READ_ONCE(st->sync_defer) != NULL)
                sp->state_flags |= htons(PFSTATE_ACK);
        if (!SLIST_EMPTY(&st->src_nodes))
                sp->sync_flags |= PFSYNC_FLAG_SRCNODE;

        sp->id = st->id;
        sp->creatorid = st->creatorid;
        pf_state_peer_hton(&st->src, &sp->src);
        pf_state_peer_hton(&st->dst, &sp->dst);

        if (st->rule.ptr == NULL)
                sp->rule = htonl(-1);
        else
                sp->rule = htonl(st->rule.ptr->nr);
        if (st->anchor.ptr == NULL)
                sp->anchor = htonl(-1);
        else
                sp->anchor = htonl(st->anchor.ptr->nr);
        sp->nat_rule = htonl(-1);       /* left for compat, nat_rule is gone */

        pf_state_counter_hton(st->packets[0], sp->packets[0]);
        pf_state_counter_hton(st->packets[1], sp->packets[1]);
        pf_state_counter_hton(st->bytes[0], sp->bytes[0]);
        pf_state_counter_hton(st->bytes[1], sp->bytes[1]);

        sp->max_mss = htons(st->max_mss);
        sp->min_ttl = st->min_ttl;
        sp->set_tos = st->set_tos;
        sp->set_prio[0] = st->set_prio[0];
        sp->set_prio[1] = st->set_prio[1];
}

int
pf_state_alloc_scrub_memory(const struct pfsync_state_peer *s,
    struct pf_state_peer *d)
{
        if (s->scrub.scrub_flag && d->scrub == NULL)
                return (pf_normalize_tcp_alloc(d));

        return (0);
}

#if NPFSYNC > 0
int
pf_state_import(const struct pfsync_state *sp, int flags)
{
        struct pf_state *st = NULL;
        struct pf_state_key *skw = NULL, *sks = NULL;
        struct pf_rule *r = NULL;
        struct pfi_kif  *kif;
        int pool_flags;
        int error = ENOMEM;
        int n = 0;

        PF_ASSERT_LOCKED();

        if (sp->creatorid == 0) {
                DPFPRINTF(LOG_NOTICE, "%s: invalid creator id: %08x", __func__,
                    ntohl(sp->creatorid));
                return (EINVAL);
        }

        if ((kif = pfi_kif_get(sp->ifname, NULL)) == NULL) {
                DPFPRINTF(LOG_NOTICE, "%s: unknown interface: %s", __func__,
                    sp->ifname);
                if (flags & PFSYNC_SI_IOCTL)
                        return (EINVAL);
                return (0);     /* skip this state */
        }

        if (sp->af == 0)
                return (0);     /* skip this state */

        /*
         * If the ruleset checksums match or the state is coming from the ioctl,
         * it's safe to associate the state with the rule of that number.
         */
        if (sp->rule != htonl(-1) && sp->anchor == htonl(-1) &&
            (flags & (PFSYNC_SI_IOCTL | PFSYNC_SI_CKSUM)) &&
            ntohl(sp->rule) < pf_main_ruleset.rules.active.rcount) {
                TAILQ_FOREACH(r, pf_main_ruleset.rules.active.ptr, entries)
                        if (ntohl(sp->rule) == n++)
                                break;
        } else
                r = &pf_default_rule;

        if ((r->max_states && r->states_cur >= r->max_states))
                goto cleanup;

        if (flags & PFSYNC_SI_IOCTL)
                pool_flags = PR_WAITOK | PR_LIMITFAIL | PR_ZERO;
        else
                pool_flags = PR_NOWAIT | PR_LIMITFAIL | PR_ZERO;

        if ((st = pool_get(&pf_state_pl, pool_flags)) == NULL)
                goto cleanup;

        if ((skw = pf_alloc_state_key(pool_flags)) == NULL)
                goto cleanup;

        if ((sp->key[PF_SK_WIRE].af &&
            (sp->key[PF_SK_WIRE].af != sp->key[PF_SK_STACK].af)) ||
            PF_ANEQ(&sp->key[PF_SK_WIRE].addr[0],
            &sp->key[PF_SK_STACK].addr[0], sp->af) ||
            PF_ANEQ(&sp->key[PF_SK_WIRE].addr[1],
            &sp->key[PF_SK_STACK].addr[1], sp->af) ||
            sp->key[PF_SK_WIRE].port[0] != sp->key[PF_SK_STACK].port[0] ||
            sp->key[PF_SK_WIRE].port[1] != sp->key[PF_SK_STACK].port[1] ||
            sp->key[PF_SK_WIRE].rdomain != sp->key[PF_SK_STACK].rdomain) {
                if ((sks = pf_alloc_state_key(pool_flags)) == NULL)
                        goto cleanup;
        } else
                sks = pf_state_key_ref(skw);

        /* allocate memory for scrub info */
        if (pf_state_alloc_scrub_memory(&sp->src, &st->src) ||
            pf_state_alloc_scrub_memory(&sp->dst, &st->dst))
                goto cleanup;

        /* copy to state key(s) */
        skw->addr[0] = sp->key[PF_SK_WIRE].addr[0];
        skw->addr[1] = sp->key[PF_SK_WIRE].addr[1];
        skw->port[0] = sp->key[PF_SK_WIRE].port[0];
        skw->port[1] = sp->key[PF_SK_WIRE].port[1];
        skw->rdomain = ntohs(sp->key[PF_SK_WIRE].rdomain);
        skw->proto = sp->proto;
        if (!(skw->af = sp->key[PF_SK_WIRE].af))
                skw->af = sp->af;
        skw->hash = pf_pkt_hash(skw->af, skw->proto,
            &skw->addr[0], &skw->addr[1], skw->port[0], skw->port[1]);

        if (sks != skw) {
                sks->addr[0] = sp->key[PF_SK_STACK].addr[0];
                sks->addr[1] = sp->key[PF_SK_STACK].addr[1];
                sks->port[0] = sp->key[PF_SK_STACK].port[0];
                sks->port[1] = sp->key[PF_SK_STACK].port[1];
                sks->rdomain = ntohs(sp->key[PF_SK_STACK].rdomain);
                if (!(sks->af = sp->key[PF_SK_STACK].af))
                        sks->af = sp->af;
                if (sks->af != skw->af) {
                        switch (sp->proto) {
                        case IPPROTO_ICMP:
                                sks->proto = IPPROTO_ICMPV6;
                                break;
                        case IPPROTO_ICMPV6:
                                sks->proto = IPPROTO_ICMP;
                                break;
                        default:
                                sks->proto = sp->proto;
                        }
                } else
                        sks->proto = sp->proto;

                if (((sks->af != AF_INET) && (sks->af != AF_INET6)) ||
                    ((skw->af != AF_INET) && (skw->af != AF_INET6))) {
                        error = EINVAL;
                        goto cleanup;
                }

                sks->hash = pf_pkt_hash(sks->af, sks->proto,
                    &sks->addr[0], &sks->addr[1], sks->port[0], sks->port[1]);

        } else if ((sks->af != AF_INET) && (sks->af != AF_INET6)) {
                error = EINVAL;
                goto cleanup;
        }
        st->rtableid[PF_SK_WIRE] = ntohl(sp->rtableid[PF_SK_WIRE]);
        st->rtableid[PF_SK_STACK] = ntohl(sp->rtableid[PF_SK_STACK]);

        /* copy to state */
        st->rt_addr = sp->rt_addr;
        st->rt = sp->rt;
        st->creation = getuptime() - ntohl(sp->creation);
        st->expire = getuptime();
        if (ntohl(sp->expire)) {
                u_int32_t timeout;

                timeout = r->timeout[sp->timeout];
                if (!timeout)
                        timeout = pf_default_rule.timeout[sp->timeout];

                /* sp->expire may have been adaptively scaled by export. */
                st->expire -= timeout - ntohl(sp->expire);
        }

        st->direction = sp->direction;
        st->log = sp->log;
        st->timeout = sp->timeout;
        st->state_flags = ntohs(sp->state_flags);
        st->max_mss = ntohs(sp->max_mss);
        st->min_ttl = sp->min_ttl;
        st->set_tos = sp->set_tos;
        st->set_prio[0] = sp->set_prio[0];
        st->set_prio[1] = sp->set_prio[1];

        st->id = sp->id;
        st->creatorid = sp->creatorid;
        pf_state_peer_ntoh(&sp->src, &st->src);
        pf_state_peer_ntoh(&sp->dst, &st->dst);

        st->rule.ptr = r;
        st->anchor.ptr = NULL;

        PF_REF_INIT(st->refcnt);
        mtx_init(&st->mtx, IPL_NET);

        /* XXX when we have anchors, use STATE_INC_COUNTERS */
        r->states_cur++;
        r->states_tot++;

        st->sync_state = PFSYNC_S_NONE;
        st->pfsync_time = getuptime();
#if NPFSYNC > 0
        pfsync_init_state(st, skw, sks, flags);
#endif

        if (pf_state_insert(kif, &skw, &sks, st) != 0) {
                /* XXX when we have anchors, use STATE_DEC_COUNTERS */
                r->states_cur--;
                error = EEXIST;
                goto cleanup_state;
        }

        return (0);

 cleanup:
        if (skw != NULL)
                pf_state_key_unref(skw);
        if (sks != NULL)
                pf_state_key_unref(sks);

 cleanup_state: /* pf_state_insert frees the state keys */
        if (st) {
                if (st->dst.scrub)
                        pool_put(&pf_state_scrub_pl, st->dst.scrub);
                if (st->src.scrub)
                        pool_put(&pf_state_scrub_pl, st->src.scrub);
                pool_put(&pf_state_pl, st);
        }
        return (error);
}
#endif /* NPFSYNC > 0 */

/* END state table stuff */

void             pf_purge_states(void *);
struct task      pf_purge_states_task =
                     TASK_INITIALIZER(pf_purge_states, NULL);

void             pf_purge_states_tick(void *);
struct timeout   pf_purge_states_to =
                     TIMEOUT_INITIALIZER(pf_purge_states_tick, NULL);

unsigned int     pf_purge_expired_states(unsigned int, unsigned int);

/*
 * how many states to scan this interval.
 *
 * this is set when the timeout fires, and reduced by the task. the
 * task will reschedule itself until the limit is reduced to zero,
 * and then it adds the timeout again.
 */
unsigned int pf_purge_states_limit;

/*
 * limit how many states are processed with locks held per run of
 * the state purge task.
 */
unsigned int pf_purge_states_collect = 64;

 void
pf_purge_states_tick(void *null)
 {
        unsigned int limit = pf_status.states;
        unsigned int interval = pf_default_rule.timeout[PFTM_INTERVAL];

        if (limit == 0) {
                timeout_add_sec(&pf_purge_states_to, 1);
                return;
        }

        /*
         * process a fraction of the state table every second
         */

        if (interval > 1)
                limit /= interval;

        pf_purge_states_limit = limit;
        task_add(systqmp, &pf_purge_states_task);
}

void
pf_purge_states(void *null)
{
        unsigned int limit;
        unsigned int scanned;

        limit = pf_purge_states_limit;
        if (limit < pf_purge_states_collect)
                limit = pf_purge_states_collect;

        scanned = pf_purge_expired_states(limit, pf_purge_states_collect);
        if (scanned >= pf_purge_states_limit) {
                /* we've run out of states to scan this "interval" */
                timeout_add_sec(&pf_purge_states_to, 1);
                return;
        }

        pf_purge_states_limit -= scanned;
        task_add(systqmp, &pf_purge_states_task);
}

void             pf_purge_tick(void *);
struct timeout   pf_purge_to =
                     TIMEOUT_INITIALIZER(pf_purge_tick, NULL);

void             pf_purge(void *);
struct task      pf_purge_task =
                     TASK_INITIALIZER(pf_purge, NULL);

void
pf_purge_tick(void *null)
{
        task_add(systqmp, &pf_purge_task);
}

void
pf_purge(void *null)
{
        unsigned int interval = max(1, pf_default_rule.timeout[PFTM_INTERVAL]);

        PF_LOCK();

        pf_purge_expired_src_nodes();
        pf_source_purge();

        PF_UNLOCK();

        /*
         * Fragments don't require PF_LOCK(), they use their own lock.
         */
        pf_purge_expired_fragments();

        /* interpret the interval as idle time between runs */
        timeout_add_sec(&pf_purge_to, interval);
}

int32_t
pf_state_expires(const struct pf_state *st, uint8_t stimeout)
{
        u_int32_t       timeout;
        u_int32_t       start;
        u_int32_t       end;
        u_int32_t       states;

        /*
         * pf_state_expires is used by the state purge task to
         * decide if a state is a candidate for cleanup, and by the
         * pfsync state export code to populate an expiry time.
         *
         * this function may be called by the state purge task while
         * the state is being modified. avoid inconsistent reads of
         * state->timeout by having the caller do the read (and any
         * checks it needs to do on the same variable) and then pass
         * their view of the timeout in here for this function to use.
         * the only consequence of using a stale timeout value is
         * that the state won't be a candidate for purging until the
         * next pass of the purge task.
         */

        /* handle all PFTM_* >= PFTM_MAX here */
        if (stimeout >= PFTM_MAX)
                return (0);

        KASSERT(stimeout < PFTM_MAX);

        timeout = st->rule.ptr->timeout[stimeout];
        if (!timeout)
                timeout = pf_default_rule.timeout[stimeout];

        start = st->rule.ptr->timeout[PFTM_ADAPTIVE_START];
        if (start) {
                end = st->rule.ptr->timeout[PFTM_ADAPTIVE_END];
                states = st->rule.ptr->states_cur;
        } else {
                start = pf_default_rule.timeout[PFTM_ADAPTIVE_START];
                end = pf_default_rule.timeout[PFTM_ADAPTIVE_END];
                states = pf_status.states;
        }
        if (end && states > start && start < end) {
                if (states >= end)
                        return (0);

                timeout = (u_int64_t)timeout * (end - states) / (end - start);
        }

        return (st->expire + timeout);
}

void
pf_purge_expired_src_nodes(void)
{
        struct pf_src_node              *cur, *next;

        PF_ASSERT_LOCKED();

        RB_FOREACH_SAFE(cur, pf_src_tree, &tree_src_tracking, next) {
                if (cur->states == 0 && cur->expire <= getuptime()) {
                        pf_remove_src_node(cur);
                }
        }
}

void
pf_src_tree_remove_state(struct pf_state *st)
{
        u_int32_t                timeout;
        struct pf_sn_item       *sni;

        while ((sni = SLIST_FIRST(&st->src_nodes)) != NULL) {
                SLIST_REMOVE_HEAD(&st->src_nodes, next);
                if (st->src.tcp_est)
                        --sni->sn->conn;
                if (--sni->sn->states == 0) {
                        timeout = st->rule.ptr->timeout[PFTM_SRC_NODE];
                        if (!timeout)
                                timeout =
                                    pf_default_rule.timeout[PFTM_SRC_NODE];
                        sni->sn->expire = getuptime() + timeout;
                }
                pool_put(&pf_sn_item_pl, sni);
        }
}

void
pf_remove_state(struct pf_state *st)
{
        struct pf_state_link *pfl;

        PF_ASSERT_LOCKED();

        mtx_enter(&st->mtx);
        if (st->timeout == PFTM_UNLINKED) {
                mtx_leave(&st->mtx);
                return;
        }
        st->timeout = PFTM_UNLINKED;
        mtx_leave(&st->mtx);

        /* handle load balancing related tasks */
        pf_postprocess_addr(st);

        if (st->src.state == PF_TCPS_PROXY_DST) {
                pf_send_tcp(st->rule.ptr, st->key[PF_SK_WIRE]->af,
                    &st->key[PF_SK_WIRE]->addr[1],
                    &st->key[PF_SK_WIRE]->addr[0],
                    st->key[PF_SK_WIRE]->port[1],
                    st->key[PF_SK_WIRE]->port[0],
                    st->src.seqhi, st->src.seqlo + 1,
                    TH_RST|TH_ACK, 0, 0, 0, 1, st->tag,
                    st->key[PF_SK_WIRE]->rdomain, NULL);
        }
        if (st->key[PF_SK_STACK]->proto == IPPROTO_TCP)
                pf_set_protostate(st, PF_PEER_BOTH, TCPS_CLOSED);

        while ((pfl = SLIST_FIRST(&st->linkage)) != NULL) {
                struct pf_state_link_list *list;
                unsigned int gen;

                SLIST_REMOVE_HEAD(&st->linkage, pfl_linkage);

                switch (pfl->pfl_type) {
                case PF_STATE_LINK_TYPE_STATELIM: {
                        struct pf_statelim *stlim;

                        stlim = pf_statelim_find(st->statelim);
                        KASSERTMSG(stlim != NULL,
                            "pf_state %p pfl %p cannot find statelim %u",
                            st, pfl, st->statelim);

                        gen = pf_statelim_enter(stlim);
                        stlim->pfstlim_inuse--;
                        pf_statelim_leave(stlim, gen);

                        list = &stlim->pfstlim_states;
                        break;
                }
                case PF_STATE_LINK_TYPE_SOURCELIM: {
                        struct pf_sourcelim *srlim;
                        struct pf_source key, *sr;

                        srlim = pf_sourcelim_find(st->sourcelim);
                        KASSERTMSG(srlim != NULL,
                            "pf_state %p pfl %p cannot find sourcelim %u",
                            st, pfl, st->sourcelim);

                        pf_source_key(srlim, &key,
                            st->key[PF_SK_WIRE]->af,
                            st->key[PF_SK_WIRE]->rdomain,
                            &st->key[PF_SK_WIRE]->addr[0 /* XXX or 1? */]);

                        sr = pf_source_find(srlim, &key);
                        KASSERTMSG(sr != NULL,
                            "pf_state %p pfl %p cannot find source in %u",
                            st, pfl, st->sourcelim);

                        gen = pf_sourcelim_enter(srlim);
                        srlim->pfsrlim_counters.inuse--;
                        pf_sourcelim_leave(srlim, gen);
                        pf_source_rele(sr);

                        list = &sr->pfsr_states;
                        break;
                }
                default:
                        panic("%s: unexpected link type on pfl %p",
                            __func__, pfl);
                }

                PF_STATE_ASSERT_LOCKED();
                TAILQ_REMOVE(list, pfl, pfl_link);
                pool_put(&pf_state_link_pl, pfl);
        }

        RBT_REMOVE(pf_state_tree_id, &tree_id, st);
#if NPFLOW > 0
        if (st->state_flags & PFSTATE_PFLOW)
                export_pflow(st);
#endif  /* NPFLOW > 0 */
#if NPFSYNC > 0
        pfsync_delete_state(st);
#endif  /* NPFSYNC > 0 */
        pf_src_tree_remove_state(st);
        pf_detach_state(st);
}

void
pf_remove_divert_state(struct inpcb *inp)
{
        struct pf_state_key     *sk;
        struct pf_state_item    *si;

        PF_ASSERT_UNLOCKED();

        if (READ_ONCE(inp->inp_pf_sk) == NULL)
                return;

        mtx_enter(&pf_inp_mtx);
        sk = pf_state_key_ref(inp->inp_pf_sk);
        mtx_leave(&pf_inp_mtx);
        if (sk == NULL)
                return;

        PF_LOCK();
        PF_STATE_ENTER_WRITE();
        TAILQ_FOREACH(si, &sk->sk_states, si_entry) {
                struct pf_state *sist = si->si_st;
                if (sk == sist->key[PF_SK_STACK] && sist->rule.ptr &&
                    (sist->rule.ptr->divert.type == PF_DIVERT_TO ||
                     sist->rule.ptr->divert.type == PF_DIVERT_REPLY)) {
                        if (sist->key[PF_SK_STACK]->proto == IPPROTO_TCP &&
                            sist->key[PF_SK_WIRE] != sist->key[PF_SK_STACK]) {
                                /*
                                 * If the local address is translated, keep
                                 * the state for "tcp.closed" seconds to
                                 * prevent its source port from being reused.
                                 */
                                if (sist->src.state < TCPS_FIN_WAIT_2 ||
                                    sist->dst.state < TCPS_FIN_WAIT_2) {
                                        pf_set_protostate(sist, PF_PEER_BOTH,
                                            TCPS_TIME_WAIT);
                                        pf_update_state_timeout(sist,
                                            PFTM_TCP_CLOSED);
                                        sist->expire = getuptime();
                                }
                                sist->state_flags |= PFSTATE_INP_UNLINKED;
                        } else
                                pf_remove_state(sist);
                        break;
                }
        }
        PF_STATE_EXIT_WRITE();
        PF_UNLOCK();

        pf_state_key_unref(sk);
}

void
pf_free_state(struct pf_state *st)
{
        struct pf_rule_item *ri;

        PF_ASSERT_LOCKED();

#if NPFSYNC > 0
        if (pfsync_state_in_use(st))
                return;
#endif  /* NPFSYNC > 0 */

        KASSERT(st->timeout == PFTM_UNLINKED);
        if (--st->rule.ptr->states_cur == 0 &&
            st->rule.ptr->src_nodes == 0)
                pf_rm_rule(NULL, st->rule.ptr);
        if (st->anchor.ptr != NULL)
                if (--st->anchor.ptr->states_cur == 0)
                        pf_rm_rule(NULL, st->anchor.ptr);
        while ((ri = SLIST_FIRST(&st->match_rules))) {
                SLIST_REMOVE_HEAD(&st->match_rules, entry);
                if (--ri->r->states_cur == 0 &&
                    ri->r->src_nodes == 0)
                        pf_rm_rule(NULL, ri->r);
                pool_put(&pf_rule_item_pl, ri);
        }
        pf_normalize_tcp_cleanup(st);
        pfi_kif_unref(st->kif, PFI_KIF_REF_STATE);
        pf_state_list_remove(&pf_state_list, st);
        if (st->tag)
                pf_tag_unref(st->tag);
        pf_state_unref(st);
        counters_inc(pf_status_fcounters, FCNT_STATE_REMOVALS);
        pf_status.states--;
}

unsigned int
pf_purge_expired_states(const unsigned int limit, const unsigned int collect)
{
        /*
         * this task/thread/context/whatever is the only thing that
         * removes states from the pf_state_list, so the cur reference
         * it holds between calls is guaranteed to still be in the
         * list.
         */
        static struct pf_state  *cur = NULL;

        struct pf_state         *head, *tail;
        struct pf_state         *st;
        SLIST_HEAD(pf_state_gcl, pf_state) gcl = SLIST_HEAD_INITIALIZER(gcl);
        time_t                   now;
        unsigned int             scanned;
        unsigned int             collected = 0;

        PF_ASSERT_UNLOCKED();

        rw_enter_read(&pf_state_list.pfs_rwl);

        mtx_enter(&pf_state_list.pfs_mtx);
        head = TAILQ_FIRST(&pf_state_list.pfs_list);
        tail = TAILQ_LAST(&pf_state_list.pfs_list, pf_state_queue);
        mtx_leave(&pf_state_list.pfs_mtx);

        if (head == NULL) {
                /* the list is empty */
                rw_exit_read(&pf_state_list.pfs_rwl);
                return (limit);
        }

        /* (re)start at the front of the list */
        if (cur == NULL)
                cur = head;

        now = getuptime();

        for (scanned = 0; scanned < limit; scanned++) {
                uint8_t stimeout = cur->timeout;
                unsigned int limited = 0;

                if ((stimeout == PFTM_UNLINKED) ||
                    (pf_state_expires(cur, stimeout) <= now)) {
                        st = pf_state_ref(cur);
                        SLIST_INSERT_HEAD(&gcl, st, gc_list);

                        if (++collected >= collect)
                                limited = 1;
                }

                /* don't iterate past the end of our view of the list */
                if (cur == tail) {
                        cur = NULL;
                        break;
                }

                cur = TAILQ_NEXT(cur, entry_list);

                /* don't spend too much time here. */
                if (ISSET(READ_ONCE(curcpu()->ci_schedstate.spc_schedflags),
                     SPCF_SHOULDYIELD) || limited)
                        break;
        }

        rw_exit_read(&pf_state_list.pfs_rwl);

        if (SLIST_EMPTY(&gcl))
                return (scanned);

        rw_enter_write(&pf_state_list.pfs_rwl);
        PF_LOCK();
        PF_STATE_ENTER_WRITE();
        SLIST_FOREACH(st, &gcl, gc_list) {
                if (st->timeout != PFTM_UNLINKED)
                        pf_remove_state(st);

                pf_free_state(st);
        }
        PF_STATE_EXIT_WRITE();
        PF_UNLOCK();
        rw_exit_write(&pf_state_list.pfs_rwl);

        while ((st = SLIST_FIRST(&gcl)) != NULL) {
                SLIST_REMOVE_HEAD(&gcl, gc_list);
                pf_state_unref(st);
        }

        return (scanned);
}

int
pf_tbladdr_setup(struct pf_ruleset *rs, struct pf_addr_wrap *aw, int wait)
{
        if (aw->type != PF_ADDR_TABLE)
                return (0);
        if ((aw->p.tbl = pfr_attach_table(rs, aw->v.tblname, wait)) == NULL)
                return (1);
        return (0);
}

void
pf_tbladdr_remove(struct pf_addr_wrap *aw)
{
        if (aw->type != PF_ADDR_TABLE || aw->p.tbl == NULL)
                return;
        pfr_detach_table(aw->p.tbl);
        aw->p.tbl = NULL;
}

void
pf_tbladdr_copyout(struct pf_addr_wrap *aw)
{
        struct pfr_ktable *kt = aw->p.tbl;

        if (aw->type != PF_ADDR_TABLE || kt == NULL)
                return;
        if (!(kt->pfrkt_flags & PFR_TFLAG_ACTIVE) && kt->pfrkt_root != NULL)
                kt = kt->pfrkt_root;
        aw->p.tbl = NULL;
        aw->p.tblcnt = (kt->pfrkt_flags & PFR_TFLAG_ACTIVE) ?
                kt->pfrkt_cnt : -1;
}

void
pf_print_host(struct pf_addr *addr, u_int16_t p, sa_family_t af)
{
        switch (af) {
        case AF_INET: {
                u_int32_t a = ntohl(addr->addr32[0]);
                addlog("%u.%u.%u.%u", (a>>24)&255, (a>>16)&255,
                    (a>>8)&255, a&255);
                if (p) {
                        p = ntohs(p);
                        addlog(":%u", p);
                }
                break;
        }
#ifdef INET6
        case AF_INET6: {
                u_int16_t b;
                u_int8_t i, curstart, curend, maxstart, maxend;
                curstart = curend = maxstart = maxend = 255;
                for (i = 0; i < 8; i++) {
                        if (!addr->addr16[i]) {
                                if (curstart == 255)
                                        curstart = i;
                                curend = i;
                        } else {
                                if ((curend - curstart) >
                                    (maxend - maxstart)) {
                                        maxstart = curstart;
                                        maxend = curend;
                                }
                                curstart = curend = 255;
                        }
                }
                if ((curend - curstart) >
                    (maxend - maxstart)) {
                        maxstart = curstart;
                        maxend = curend;
                }
                for (i = 0; i < 8; i++) {
                        if (i >= maxstart && i <= maxend) {
                                if (i == 0)
                                        addlog(":");
                                if (i == maxend)
                                        addlog(":");
                        } else {
                                b = ntohs(addr->addr16[i]);
                                addlog("%x", b);
                                if (i < 7)
                                        addlog(":");
                        }
                }
                if (p) {
                        p = ntohs(p);
                        addlog("[%u]", p);
                }
                break;
        }
#endif /* INET6 */
        }
}

void
pf_print_state(struct pf_state *st)
{
        pf_print_state_parts(st, NULL, NULL);
}

void
pf_print_state_parts(struct pf_state *st,
    struct pf_state_key *skwp, struct pf_state_key *sksp)
{
        struct pf_state_key *skw, *sks;
        u_int8_t proto, dir;

        /* Do our best to fill these, but they're skipped if NULL */
        skw = skwp ? skwp : (st ? st->key[PF_SK_WIRE] : NULL);
        sks = sksp ? sksp : (st ? st->key[PF_SK_STACK] : NULL);
        proto = skw ? skw->proto : (sks ? sks->proto : 0);
        dir = st ? st->direction : 0;

        switch (proto) {
        case IPPROTO_IPV4:
                addlog("IPv4");
                break;
        case IPPROTO_IPV6:
                addlog("IPv6");
                break;
        case IPPROTO_TCP:
                addlog("TCP");
                break;
        case IPPROTO_UDP:
                addlog("UDP");
                break;
        case IPPROTO_ICMP:
                addlog("ICMP");
                break;
        case IPPROTO_ICMPV6:
                addlog("ICMPv6");
                break;
        default:
                addlog("%u", proto);
                break;
        }
        switch (dir) {
        case PF_IN:
                addlog(" in");
                break;
        case PF_OUT:
                addlog(" out");
                break;
        }
        if (skw) {
                addlog(" wire: (%d) ", skw->rdomain);
                pf_print_host(&skw->addr[0], skw->port[0], skw->af);
                addlog(" ");
                pf_print_host(&skw->addr[1], skw->port[1], skw->af);
        }
        if (sks) {
                addlog(" stack: (%d) ", sks->rdomain);
                if (sks != skw) {
                        pf_print_host(&sks->addr[0], sks->port[0], sks->af);
                        addlog(" ");
                        pf_print_host(&sks->addr[1], sks->port[1], sks->af);
                } else
                        addlog("-");
        }
        if (st) {
                if (proto == IPPROTO_TCP) {
                        addlog(" [lo=%u high=%u win=%u modulator=%u",
                            st->src.seqlo, st->src.seqhi,
                            st->src.max_win, st->src.seqdiff);
                        if (st->src.wscale && st->dst.wscale)
                                addlog(" wscale=%u",
                                    st->src.wscale & PF_WSCALE_MASK);
                        addlog("]");
                        addlog(" [lo=%u high=%u win=%u modulator=%u",
                            st->dst.seqlo, st->dst.seqhi,
                            st->dst.max_win, st->dst.seqdiff);
                        if (st->src.wscale && st->dst.wscale)
                                addlog(" wscale=%u",
                                st->dst.wscale & PF_WSCALE_MASK);
                        addlog("]");
                }
                addlog(" %u:%u", st->src.state, st->dst.state);
                if (st->rule.ptr)
                        addlog(" @%d", st->rule.ptr->nr);
        }
}

void
pf_print_flags(u_int8_t f)
{
        if (f)
                addlog(" ");
        if (f & TH_FIN)
                addlog("F");
        if (f & TH_SYN)
                addlog("S");
        if (f & TH_RST)
                addlog("R");
        if (f & TH_PUSH)
                addlog("P");
        if (f & TH_ACK)
                addlog("A");
        if (f & TH_URG)
                addlog("U");
        if (f & TH_ECE)
                addlog("E");
        if (f & TH_CWR)
                addlog("W");
}

#define PF_SET_SKIP_STEPS(i)                                    \
        do {                                                    \
                while (head[i] != cur) {                        \
                        head[i]->skip[i].ptr = cur;             \
                        head[i] = TAILQ_NEXT(head[i], entries); \
                }                                               \
        } while (0)

void
pf_calc_skip_steps(struct pf_rulequeue *rules)
{
        struct pf_rule *cur, *prev, *head[PF_SKIP_COUNT];
        int i;

        cur = TAILQ_FIRST(rules);
        prev = cur;
        for (i = 0; i < PF_SKIP_COUNT; ++i)
                head[i] = cur;
        while (cur != NULL) {
                if (cur->kif != prev->kif || cur->ifnot != prev->ifnot)
                        PF_SET_SKIP_STEPS(PF_SKIP_IFP);
                if (cur->direction != prev->direction)
                        PF_SET_SKIP_STEPS(PF_SKIP_DIR);
                if (cur->onrdomain != prev->onrdomain ||
                    cur->ifnot != prev->ifnot)
                        PF_SET_SKIP_STEPS(PF_SKIP_RDOM);
                if (cur->af != prev->af)
                        PF_SET_SKIP_STEPS(PF_SKIP_AF);
                if (cur->proto != prev->proto)
                        PF_SET_SKIP_STEPS(PF_SKIP_PROTO);
                if (cur->src.neg != prev->src.neg ||
                    pf_addr_wrap_neq(&cur->src.addr, &prev->src.addr))
                        PF_SET_SKIP_STEPS(PF_SKIP_SRC_ADDR);
                if (cur->dst.neg != prev->dst.neg ||
                    pf_addr_wrap_neq(&cur->dst.addr, &prev->dst.addr))
                        PF_SET_SKIP_STEPS(PF_SKIP_DST_ADDR);
                if (cur->src.port[0] != prev->src.port[0] ||
                    cur->src.port[1] != prev->src.port[1] ||
                    cur->src.port_op != prev->src.port_op)
                        PF_SET_SKIP_STEPS(PF_SKIP_SRC_PORT);
                if (cur->dst.port[0] != prev->dst.port[0] ||
                    cur->dst.port[1] != prev->dst.port[1] ||
                    cur->dst.port_op != prev->dst.port_op)
                        PF_SET_SKIP_STEPS(PF_SKIP_DST_PORT);

                prev = cur;
                cur = TAILQ_NEXT(cur, entries);
        }
        for (i = 0; i < PF_SKIP_COUNT; ++i)
                PF_SET_SKIP_STEPS(i);
}

int
pf_addr_wrap_neq(struct pf_addr_wrap *aw1, struct pf_addr_wrap *aw2)
{
        if (aw1->type != aw2->type)
                return (1);
        switch (aw1->type) {
        case PF_ADDR_ADDRMASK:
        case PF_ADDR_RANGE:
                if (PF_ANEQ(&aw1->v.a.addr, &aw2->v.a.addr, AF_INET6))
                        return (1);
                if (PF_ANEQ(&aw1->v.a.mask, &aw2->v.a.mask, AF_INET6))
                        return (1);
                return (0);
        case PF_ADDR_DYNIFTL:
                return (aw1->p.dyn->pfid_kt != aw2->p.dyn->pfid_kt);
        case PF_ADDR_NONE:
        case PF_ADDR_NOROUTE:
        case PF_ADDR_URPFFAILED:
                return (0);
        case PF_ADDR_TABLE:
                return (aw1->p.tbl != aw2->p.tbl);
        case PF_ADDR_RTLABEL:
                return (aw1->v.rtlabel != aw2->v.rtlabel);
        default:
                addlog("invalid address type: %d\n", aw1->type);
                return (1);
        }
}

/* This algorithm computes 'a + b - c' in ones-complement using a trick to
 * emulate at most one ones-complement subtraction. This thereby limits net
 * carries/borrows to at most one, eliminating a reduction step and saving one
 * each of +, >>, & and ~.
 *
 * def. x mod y = x - (x//y)*y for integer x,y
 * def. sum = x mod 2^16
 * def. accumulator = (x >> 16) mod 2^16
 *
 * The trick works as follows: subtracting exactly one u_int16_t from the
 * u_int32_t x incurs at most one underflow, wrapping its upper 16-bits, the
 * accumulator, to 2^16 - 1. Adding this to the 16-bit sum preserves the
 * ones-complement borrow:
 *
 *  (sum + accumulator) mod 2^16
 * =    { assume underflow: accumulator := 2^16 - 1 }
 *  (sum + 2^16 - 1) mod 2^16
 * =    { mod }
 *  (sum - 1) mod 2^16
 *
 * Although this breaks for sum = 0, giving 0xffff, which is ones-complement's
 * other zero, not -1, that cannot occur: the 16-bit sum cannot be underflown
 * to zero as that requires subtraction of at least 2^16, which exceeds a
 * single u_int16_t's range.
 *
 * We use the following theorem to derive the implementation:
 *
 * th. (x + (y mod z)) mod z  =  (x + y) mod z   (0)
 * proof.
 *     (x + (y mod z)) mod z
 *    =  { def mod }
 *     (x + y - (y//z)*z) mod z
 *    =  { (a + b*c) mod c = a mod c }
 *     (x + y) mod z                    [end of proof]
 *
 * ... and thereby obtain:
 *
 *  (sum + accumulator) mod 2^16
 * =    { def. accumulator, def. sum }
 *  (x mod 2^16 + (x >> 16) mod 2^16) mod 2^16
 * =    { (0), twice }
 *  (x + (x >> 16)) mod 2^16
 * =    { x mod 2^n = x & (2^n - 1) }
 *  (x + (x >> 16)) & 0xffff
 *
 * Note: this serves also as a reduction step for at most one add (as the
 * trailing mod 2^16 prevents further reductions by destroying carries).
 */
__inline void
pf_cksum_fixup(u_int16_t *cksum, u_int16_t was, u_int16_t now,
    u_int8_t proto)
{
        u_int32_t x;
        const int udp = proto == IPPROTO_UDP;

        x = *cksum + was - now;
        x = (x + (x >> 16)) & 0xffff;

        /* optimise: eliminate a branch when not udp */
        if (udp && *cksum == 0x0000)
                return;
        if (udp && x == 0x0000)
                x = 0xffff;

        *cksum = (u_int16_t)(x);
}

#ifdef INET6
/* pre: coverage(cksum) is superset of coverage(covered_cksum) */
static __inline void
pf_cksum_uncover(u_int16_t *cksum, u_int16_t covered_cksum, u_int8_t proto)
{
        pf_cksum_fixup(cksum, ~covered_cksum, 0x0, proto);
}

/* pre: disjoint(coverage(cksum), coverage(uncovered_cksum)) */
static __inline void
pf_cksum_cover(u_int16_t *cksum, u_int16_t uncovered_cksum, u_int8_t proto)
{
        pf_cksum_fixup(cksum, 0x0, ~uncovered_cksum, proto);
}
#endif /* INET6 */

/* pre: *a is 16-bit aligned within its packet
 *
 * This algorithm emulates 16-bit ones-complement sums on a twos-complement
 * machine by conserving ones-complement's otherwise discarded carries in the
 * upper bits of x. These accumulated carries when added to the lower 16-bits
 * over at least zero 'reduction' steps then complete the ones-complement sum.
 *
 * def. sum = x mod 2^16
 * def. accumulator = (x >> 16)
 *
 * At most two reduction steps
 *
 *   x := sum + accumulator
 * =    { def sum, def accumulator }
 *   x := x mod 2^16 + (x >> 16)
 * =    { x mod 2^n = x & (2^n - 1) }
 *   x := (x & 0xffff) + (x >> 16)
 *
 * are necessary to incorporate the accumulated carries (at most one per add)
 * i.e. to reduce x < 2^16 from at most 16 carries in the upper 16 bits.
 *
 * The function is also invariant over the endian of the host. Why?
 *
 * Define the unary transpose operator ~ on a bitstring in python slice
 * notation as lambda m: m[P:] + m[:P] , for some constant pivot P.
 *
 * th. ~ distributes over ones-complement addition, denoted by +_1, i.e.
 *
 *     ~m +_1 ~n  =  ~(m +_1 n)    (for all bitstrings m,n of equal length)
 *
 * proof. Regard the bitstrings in m +_1 n as split at P, forming at most two
 * 'half-adds'. Under ones-complement addition, each half-add carries to the
 * other, so the sum of each half-add is unaffected by their relative
 * order. Therefore:
 *
 *     ~m +_1 ~n
 *   =    { half-adds invariant under transposition }
 *     ~s
 *   =    { substitute }
 *     ~(m +_1 n)                   [end of proof]
 *
 * th. Summing two in-memory ones-complement 16-bit variables m,n on a machine
 * with the converse endian does not alter the result.
 *
 * proof.
 *        { converse machine endian: load/store transposes, P := 8 }
 *     ~(~m +_1 ~n)
 *   =    { ~ over +_1 }
 *     ~~m +_1 ~~n
 *   =    { ~ is an involution }
 *      m +_1 n                     [end of proof]
 *
 */
#define NEG(x) ((u_int16_t)~(x))
void
pf_cksum_fixup_a(u_int16_t *cksum, const struct pf_addr *a,
    const struct pf_addr *an, sa_family_t af, u_int8_t proto)
{
        u_int32_t        x;
        const u_int16_t *n = an->addr16;
        const u_int16_t *o = a->addr16;
        const int        udp = proto == IPPROTO_UDP;

        switch (af) {
        case AF_INET:
                x = *cksum + o[0] + NEG(n[0]) + o[1] + NEG(n[1]);
                break;
#ifdef INET6
        case AF_INET6:
                x = *cksum + o[0] + NEG(n[0]) + o[1] + NEG(n[1]) +\
                             o[2] + NEG(n[2]) + o[3] + NEG(n[3]) +\
                             o[4] + NEG(n[4]) + o[5] + NEG(n[5]) +\
                             o[6] + NEG(n[6]) + o[7] + NEG(n[7]);
                break;
#endif /* INET6 */
        default:
                unhandled_af(af);
        }

        x = (x & 0xffff) + (x >> 16);
        x = (x & 0xffff) + (x >> 16);

        /* optimise: eliminate a branch when not udp */
        if (udp && *cksum == 0x0000)
                return;
        if (udp && x == 0x0000)
                x = 0xffff;

        *cksum = (u_int16_t)(x);
}

int
pf_patch_8(struct pf_pdesc *pd, u_int8_t *f, u_int8_t v, bool hi)
{
        int     rewrite = 0;

        if (*f != v) {
                u_int16_t old = htons(hi ? (*f << 8) : *f);
                u_int16_t new = htons(hi ? ( v << 8) :  v);

                pf_cksum_fixup(pd->pcksum, old, new, pd->proto);
                *f = v;
                rewrite = 1;
        }

        return (rewrite);
}

/* pre: *f is 16-bit aligned within its packet */
int
pf_patch_16(struct pf_pdesc *pd, u_int16_t *f, u_int16_t v)
{
        int     rewrite = 0;

        if (*f != v) {
                pf_cksum_fixup(pd->pcksum, *f, v, pd->proto);
                *f = v;
                rewrite = 1;
        }

        return (rewrite);
}

int
pf_patch_16_unaligned(struct pf_pdesc *pd, void *f, u_int16_t v, bool hi)
{
        int             rewrite = 0;
        u_int8_t       *fb = (u_int8_t*)f;
        u_int8_t       *vb = (u_int8_t*)&v;

        if (hi && ALIGNED_POINTER(f, u_int16_t)) {
                return (pf_patch_16(pd, f, v)); /* optimise */
        }

        rewrite += pf_patch_8(pd, fb++, *vb++, hi);
        rewrite += pf_patch_8(pd, fb++, *vb++,!hi);

        return (rewrite);
}

/* pre: *f is 16-bit aligned within its packet */
/* pre: pd->proto != IPPROTO_UDP */
int
pf_patch_32(struct pf_pdesc *pd, u_int32_t *f, u_int32_t v)
{
        int             rewrite = 0;
        u_int16_t      *pc = pd->pcksum;
        u_int8_t        proto = pd->proto;

        /* optimise: inline udp fixup code is unused; let compiler scrub it */
        if (proto == IPPROTO_UDP)
                panic("%s: udp", __func__);

        /* optimise: skip *f != v guard; true for all use-cases */
        pf_cksum_fixup(pc, *f / (1 << 16), v / (1 << 16), proto);
        pf_cksum_fixup(pc, *f % (1 << 16), v % (1 << 16), proto);

        *f = v;
        rewrite = 1;

        return (rewrite);
}

int
pf_patch_32_unaligned(struct pf_pdesc *pd, void *f, u_int32_t v, bool hi)
{
        int             rewrite = 0;
        u_int8_t       *fb = (u_int8_t*)f;
        u_int8_t       *vb = (u_int8_t*)&v;

        if (hi && ALIGNED_POINTER(f, u_int32_t)) {
                return (pf_patch_32(pd, f, v)); /* optimise */
        }

        rewrite += pf_patch_8(pd, fb++, *vb++, hi);
        rewrite += pf_patch_8(pd, fb++, *vb++,!hi);
        rewrite += pf_patch_8(pd, fb++, *vb++, hi);
        rewrite += pf_patch_8(pd, fb++, *vb++,!hi);

        return (rewrite);
}

int
pf_icmp_mapping(struct pf_pdesc *pd, u_int8_t type, int *icmp_dir,
    u_int16_t *virtual_id, u_int16_t *virtual_type)
{
        /*
         * ICMP types marked with PF_OUT are typically responses to
         * PF_IN, and will match states in the opposite direction.
         * PF_IN ICMP types need to match a state with that type.
         */
        *icmp_dir = PF_OUT;

        /* Queries (and responses) */
        switch (pd->af) {
        case AF_INET:
                switch (type) {
                case ICMP_ECHO:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case ICMP_ECHOREPLY:
                        *virtual_type = ICMP_ECHO;
                        *virtual_id = pd->hdr.icmp.icmp_id;
                        break;

                case ICMP_TSTAMP:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case ICMP_TSTAMPREPLY:
                        *virtual_type = ICMP_TSTAMP;
                        *virtual_id = pd->hdr.icmp.icmp_id;
                        break;

                case ICMP_IREQ:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case ICMP_IREQREPLY:
                        *virtual_type = ICMP_IREQ;
                        *virtual_id = pd->hdr.icmp.icmp_id;
                        break;

                case ICMP_MASKREQ:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case ICMP_MASKREPLY:
                        *virtual_type = ICMP_MASKREQ;
                        *virtual_id = pd->hdr.icmp.icmp_id;
                        break;

                case ICMP_IPV6_WHEREAREYOU:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case ICMP_IPV6_IAMHERE:
                        *virtual_type = ICMP_IPV6_WHEREAREYOU;
                        *virtual_id = 0; /* Nothing sane to match on! */
                        break;

                case ICMP_MOBILE_REGREQUEST:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case ICMP_MOBILE_REGREPLY:
                        *virtual_type = ICMP_MOBILE_REGREQUEST;
                        *virtual_id = 0; /* Nothing sane to match on! */
                        break;

                case ICMP_ROUTERSOLICIT:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case ICMP_ROUTERADVERT:
                        *virtual_type = ICMP_ROUTERSOLICIT;
                        *virtual_id = 0; /* Nothing sane to match on! */
                        break;

                /* These ICMP types map to other connections */
                case ICMP_UNREACH:
                case ICMP_SOURCEQUENCH:
                case ICMP_REDIRECT:
                case ICMP_TIMXCEED:
                case ICMP_PARAMPROB:
                        /* These will not be used, but set them anyway */
                        *icmp_dir = PF_IN;
                        *virtual_type = htons(type);
                        *virtual_id = 0;
                        return (1);  /* These types match to another state */

                /*
                 * All remaining ICMP types get their own states,
                 * and will only match in one direction.
                 */
                default:
                        *icmp_dir = PF_IN;
                        *virtual_type = type;
                        *virtual_id = 0;
                        break;
                }
                break;
#ifdef INET6
        case AF_INET6:
                switch (type) {
                case ICMP6_ECHO_REQUEST:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case ICMP6_ECHO_REPLY:
                        *virtual_type = ICMP6_ECHO_REQUEST;
                        *virtual_id = pd->hdr.icmp6.icmp6_id;
                        break;

                case MLD_LISTENER_QUERY:
                case MLD_LISTENER_REPORT: {
                        struct mld_hdr *mld = &pd->hdr.mld;
                        u_int32_t h;

                        /*
                         * Listener Report can be sent by clients
                         * without an associated Listener Query.
                         * In addition to that, when Report is sent as a
                         * reply to a Query its source and destination
                         * address are different.
                         */
                        *icmp_dir = PF_IN;
                        *virtual_type = MLD_LISTENER_QUERY;
                        /* generate fake id for these messages */
                        h = mld->mld_addr.s6_addr32[0] ^
                            mld->mld_addr.s6_addr32[1] ^
                            mld->mld_addr.s6_addr32[2] ^
                            mld->mld_addr.s6_addr32[3];
                        *virtual_id = (h >> 16) ^ (h & 0xffff);
                        break;
                }

                /*
                 * ICMP6_FQDN and ICMP6_NI query/reply are the same type as
                 * ICMP6_WRU
                 */
                case ICMP6_WRUREQUEST:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case ICMP6_WRUREPLY:
                        *virtual_type = ICMP6_WRUREQUEST;
                        *virtual_id = 0; /* Nothing sane to match on! */
                        break;

                case MLD_MTRACE:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case MLD_MTRACE_RESP:
                        *virtual_type = MLD_MTRACE;
                        *virtual_id = 0; /* Nothing sane to match on! */
                        break;

                case ND_NEIGHBOR_SOLICIT:
                        *icmp_dir = PF_IN;
                        /* FALLTHROUGH */
                case ND_NEIGHBOR_ADVERT: {
                        struct nd_neighbor_solicit *nd = &pd->hdr.nd_ns;
                        u_int32_t h;

                        *virtual_type = ND_NEIGHBOR_SOLICIT;
                        /* generate fake id for these messages */
                        h = nd->nd_ns_target.s6_addr32[0] ^
                            nd->nd_ns_target.s6_addr32[1] ^
                            nd->nd_ns_target.s6_addr32[2] ^
                            nd->nd_ns_target.s6_addr32[3];
                        *virtual_id = (h >> 16) ^ (h & 0xffff);
                        /*
                         * the extra work here deals with 'keep state' option
                         * at pass rule  for unsolicited advertisement.  By
                         * returning 1 (state_icmp = 1) we override 'keep
                         * state' to 'no state' so we don't create state for
                         * unsolicited advertisements. No one expects answer to
                         * unsolicited advertisements so we should be good.
                         */
                        if (type == ND_NEIGHBOR_ADVERT) {
                                *virtual_type = htons(*virtual_type);
                                return (1);
                        }
                        break;
                }

                /*
                 * These ICMP types map to other connections.
                 * ND_REDIRECT can't be in this list because the triggering
                 * packet header is optional.
                 */
                case ICMP6_DST_UNREACH:
                case ICMP6_PACKET_TOO_BIG:
                case ICMP6_TIME_EXCEEDED:
                case ICMP6_PARAM_PROB:
                        /* These will not be used, but set them anyway */
                        *icmp_dir = PF_IN;
                        *virtual_type = htons(type);
                        *virtual_id = 0;
                        return (1);  /* These types match to another state */
                /*
                 * All remaining ICMP6 types get their own states,
                 * and will only match in one direction.
                 */
                default:
                        *icmp_dir = PF_IN;
                        *virtual_type = type;
                        *virtual_id = 0;
                        break;
                }
                break;
#endif /* INET6 */
        }
        *virtual_type = htons(*virtual_type);
        return (0);  /* These types match to their own state */
}

void
pf_translate_icmp(struct pf_pdesc *pd, struct pf_addr *qa, u_int16_t *qp,
    struct pf_addr *oa, struct pf_addr *na, u_int16_t np)
{
        /* note: doesn't trouble to fixup quoted checksums, if any */

        /* change quoted protocol port */
        if (qp != NULL)
                pf_patch_16(pd, qp, np);

        /* change quoted ip address */
        pf_cksum_fixup_a(pd->pcksum, qa, na, pd->af, pd->proto);
        pf_addrcpy(qa, na, pd->af);

        /* change network-header's ip address */
        if (oa)
                pf_translate_a(pd, oa, na);
}

/* pre: *a is 16-bit aligned within its packet */
/*      *a is a network header src/dst address */
int
pf_translate_a(struct pf_pdesc *pd, struct pf_addr *a, struct pf_addr *an)
{
        int     rewrite = 0;

        /* warning: !PF_ANEQ != PF_AEQ */
        if (!PF_ANEQ(a, an, pd->af))
                return (0);

        /* fixup transport pseudo-header, if any */
        switch (pd->proto) {
        case IPPROTO_TCP:       /* FALLTHROUGH */
        case IPPROTO_UDP:       /* FALLTHROUGH */
        case IPPROTO_ICMPV6:
                pf_cksum_fixup_a(pd->pcksum, a, an, pd->af, pd->proto);
                break;
        default:
                break;  /* assume no pseudo-header */
        }

        pf_addrcpy(a, an, pd->af);
        rewrite = 1;

        return (rewrite);
}

#ifdef INET6
/* pf_translate_af() may change pd->m, adjust local copies after calling */
int
pf_translate_af(struct pf_pdesc *pd)
{
        static const struct pf_addr     zero;
        struct ip                      *ip4;
        struct ip6_hdr                 *ip6;
        int                             copyback = 0;
        u_int                           hlen, ohlen, dlen;
        u_int16_t                      *pc;
        u_int8_t                        af_proto, naf_proto;

        hlen = (pd->naf == AF_INET) ? sizeof(*ip4) : sizeof(*ip6);
        ohlen = pd->off;
        dlen = pd->tot_len - pd->off;
        pc = pd->pcksum;

        af_proto = naf_proto = pd->proto;
        if (naf_proto == IPPROTO_ICMP)
                af_proto = IPPROTO_ICMPV6;
        if (naf_proto == IPPROTO_ICMPV6)
                af_proto = IPPROTO_ICMP;

        /* uncover stale pseudo-header */
        switch (af_proto) {
        case IPPROTO_ICMPV6:
                /* optimise: unchanged for TCP/UDP */
                pf_cksum_fixup(pc, htons(af_proto), 0x0, af_proto);
                pf_cksum_fixup(pc, htons(dlen),     0x0, af_proto);
                                /* FALLTHROUGH */
        case IPPROTO_UDP:       /* FALLTHROUGH */
        case IPPROTO_TCP:
                pf_cksum_fixup_a(pc, pd->src, &zero, pd->af, af_proto);
                pf_cksum_fixup_a(pc, pd->dst, &zero, pd->af, af_proto);
                copyback = 1;
                break;
        default:
                break;  /* assume no pseudo-header */
        }

        /* replace the network header */
        m_adj(pd->m, pd->off);
        pd->src = NULL;
        pd->dst = NULL;

        if ((M_PREPEND(pd->m, hlen, M_DONTWAIT)) == NULL) {
                pd->m = NULL;
                return (-1);
        }

        pd->off = hlen;
        pd->tot_len += hlen - ohlen;

        switch (pd->naf) {
        case AF_INET:
                ip4 = mtod(pd->m, struct ip *);
                memset(ip4, 0, hlen);
                ip4->ip_v   = IPVERSION;
                ip4->ip_hl  = hlen >> 2;
                ip4->ip_tos = pd->tos;
                ip4->ip_len = htons(hlen + dlen);
                ip4->ip_id  = htons(ip_randomid());
                ip4->ip_off = htons(IP_DF);
                ip4->ip_ttl = pd->ttl;
                ip4->ip_p   = pd->proto;
                ip4->ip_src = pd->nsaddr.v4;
                ip4->ip_dst = pd->ndaddr.v4;
                break;
        case AF_INET6:
                ip6 = mtod(pd->m, struct ip6_hdr *);
                memset(ip6, 0, hlen);
                ip6->ip6_vfc  = IPV6_VERSION;
                ip6->ip6_flow |= htonl((u_int32_t)pd->tos << 20);
                ip6->ip6_plen = htons(dlen);
                ip6->ip6_nxt  = pd->proto;
                if (!pd->ttl || pd->ttl > IPV6_DEFHLIM)
                        ip6->ip6_hlim = IPV6_DEFHLIM;
                else
                        ip6->ip6_hlim = pd->ttl;
                ip6->ip6_src  = pd->nsaddr.v6;
                ip6->ip6_dst  = pd->ndaddr.v6;
                break;
        default:
                unhandled_af(pd->naf);
        }

        /* UDP over IPv6 must be checksummed per rfc2460 p27 */
        if (naf_proto == IPPROTO_UDP && *pc == 0x0000 &&
            pd->naf == AF_INET6) {
                pd->m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT;
        }

        /* cover fresh pseudo-header */
        switch (naf_proto) {
        case IPPROTO_ICMPV6:
                /* optimise: unchanged for TCP/UDP */
                pf_cksum_fixup(pc, 0x0, htons(naf_proto), naf_proto);
                pf_cksum_fixup(pc, 0x0, htons(dlen),      naf_proto);
                                /* FALLTHROUGH */
        case IPPROTO_UDP:       /* FALLTHROUGH */
        case IPPROTO_TCP:
                pf_cksum_fixup_a(pc, &zero, &pd->nsaddr, pd->naf, naf_proto);
                pf_cksum_fixup_a(pc, &zero, &pd->ndaddr, pd->naf, naf_proto);
                copyback = 1;
                break;
        default:
                break;  /* assume no pseudo-header */
        }

        /* flush pd->pcksum */
        if (copyback)
                m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT);

        return (0);
}

int
pf_change_icmp_af(struct mbuf *m, int ipoff2, struct pf_pdesc *pd,
    struct pf_pdesc *pd2, struct pf_addr *src, struct pf_addr *dst,
    sa_family_t af, sa_family_t naf)
{
        struct mbuf             *n = NULL;
        struct ip               *ip4;
        struct ip6_hdr          *ip6;
        u_int                    hlen, ohlen, dlen;
        int                      d;

        if (af == naf || (af != AF_INET && af != AF_INET6) ||
            (naf != AF_INET && naf != AF_INET6))
                return (-1);

        /* split the mbuf chain on the quoted ip/ip6 header boundary */
        if ((n = m_split(m, ipoff2, M_DONTWAIT)) == NULL)
                return (-1);

        /* new quoted header */
        hlen = naf == AF_INET ? sizeof(*ip4) : sizeof(*ip6);
        /* old quoted header */
        ohlen = pd2->off - ipoff2;

        /* trim old quoted header */
        pf_cksum_uncover(pd->pcksum, in_cksum(n, ohlen), pd->proto);
        m_adj(n, ohlen);

        /* prepend a new, translated, quoted header */
        if ((M_PREPEND(n, hlen, M_DONTWAIT)) == NULL)
                return (-1);

        switch (naf) {
        case AF_INET:
                ip4 = mtod(n, struct ip *);
                memset(ip4, 0, sizeof(*ip4));
                ip4->ip_v   = IPVERSION;
                ip4->ip_hl  = sizeof(*ip4) >> 2;
                ip4->ip_len = htons(sizeof(*ip4) + pd2->tot_len - ohlen);
                ip4->ip_id  = htons(ip_randomid());
                ip4->ip_off = htons(IP_DF);
                ip4->ip_ttl = pd2->ttl;
                if (pd2->proto == IPPROTO_ICMPV6)
                        ip4->ip_p = IPPROTO_ICMP;
                else
                        ip4->ip_p = pd2->proto;
                ip4->ip_src = src->v4;
                ip4->ip_dst = dst->v4;
                in_hdr_cksum_out(n, NULL);
                break;
        case AF_INET6:
                ip6 = mtod(n, struct ip6_hdr *);
                memset(ip6, 0, sizeof(*ip6));
                ip6->ip6_vfc  = IPV6_VERSION;
                ip6->ip6_plen = htons(pd2->tot_len - ohlen);
                if (pd2->proto == IPPROTO_ICMP)
                        ip6->ip6_nxt = IPPROTO_ICMPV6;
                else
                        ip6->ip6_nxt = pd2->proto;
                if (!pd2->ttl || pd2->ttl > IPV6_DEFHLIM)
                        ip6->ip6_hlim = IPV6_DEFHLIM;
                else
                        ip6->ip6_hlim = pd2->ttl;
                ip6->ip6_src  = src->v6;
                ip6->ip6_dst  = dst->v6;
                break;
        }

        /* cover new quoted header */
        /* optimise: any new AF_INET header of ours sums to zero */
        if (naf != AF_INET) {
                pf_cksum_cover(pd->pcksum, in_cksum(n, hlen), pd->proto);
        }

        /* reattach modified quoted packet to outer header */
        {
                int nlen = n->m_pkthdr.len;
                m_cat(m, n);
                m->m_pkthdr.len += nlen;
        }

        /* account for altered length */
        d = hlen - ohlen;

        if (pd->proto == IPPROTO_ICMPV6) {
                /* fixup pseudo-header */
                dlen = pd->tot_len - pd->off;
                pf_cksum_fixup(pd->pcksum,
                    htons(dlen), htons(dlen + d), pd->proto);
        }

        pd->tot_len  += d;
        pd2->tot_len += d;
        pd2->off     += d;

        /* note: not bothering to update network headers as
           these due for rewrite by pf_translate_af() */

        return (0);
}


#define PTR_IP(field)   (offsetof(struct ip, field))
#define PTR_IP6(field)  (offsetof(struct ip6_hdr, field))

int
pf_translate_icmp_af(struct pf_pdesc *pd, int af, void *arg)
{
        struct icmp             *icmp4;
        struct icmp6_hdr        *icmp6;
        u_int32_t                mtu;
        int32_t                  ptr = -1;
        u_int8_t                 type;
        u_int8_t                 code;

        switch (af) {
        case AF_INET:
                icmp6 = arg;
                type  = icmp6->icmp6_type;
                code  = icmp6->icmp6_code;
                mtu   = ntohl(icmp6->icmp6_mtu);

                switch (type) {
                case ICMP6_ECHO_REQUEST:
                        type = ICMP_ECHO;
                        break;
                case ICMP6_ECHO_REPLY:
                        type = ICMP_ECHOREPLY;
                        break;
                case ICMP6_DST_UNREACH:
                        type = ICMP_UNREACH;
                        switch (code) {
                        case ICMP6_DST_UNREACH_NOROUTE:
                        case ICMP6_DST_UNREACH_BEYONDSCOPE:
                        case ICMP6_DST_UNREACH_ADDR:
                                code = ICMP_UNREACH_HOST;
                                break;
                        case ICMP6_DST_UNREACH_ADMIN:
                                code = ICMP_UNREACH_HOST_PROHIB;
                                break;
                        case ICMP6_DST_UNREACH_NOPORT:
                                code = ICMP_UNREACH_PORT;
                                break;
                        default:
                                return (-1);
                        }
                        break;
                case ICMP6_PACKET_TOO_BIG:
                        type = ICMP_UNREACH;
                        code = ICMP_UNREACH_NEEDFRAG;
                        mtu -= 20;
                        break;
                case ICMP6_TIME_EXCEEDED:
                        type = ICMP_TIMXCEED;
                        break;
                case ICMP6_PARAM_PROB:
                        switch (code) {
                        case ICMP6_PARAMPROB_HEADER:
                                type = ICMP_PARAMPROB;
                                code = ICMP_PARAMPROB_ERRATPTR;
                                ptr  = ntohl(icmp6->icmp6_pptr);

                                if (ptr == PTR_IP6(ip6_vfc))
                                        ; /* preserve */
                                else if (ptr == PTR_IP6(ip6_vfc) + 1)
                                        ptr = PTR_IP(ip_tos);
                                else if (ptr == PTR_IP6(ip6_plen) ||
                                    ptr == PTR_IP6(ip6_plen) + 1)
                                        ptr = PTR_IP(ip_len);
                                else if (ptr == PTR_IP6(ip6_nxt))
                                        ptr = PTR_IP(ip_p);
                                else if (ptr == PTR_IP6(ip6_hlim))
                                        ptr = PTR_IP(ip_ttl);
                                else if (ptr >= PTR_IP6(ip6_src) &&
                                    ptr < PTR_IP6(ip6_dst))
                                        ptr = PTR_IP(ip_src);
                                else if (ptr >= PTR_IP6(ip6_dst) &&
                                    ptr < sizeof(struct ip6_hdr))
                                        ptr = PTR_IP(ip_dst);
                                else {
                                        return (-1);
                                }
                                break;
                        case ICMP6_PARAMPROB_NEXTHEADER:
                                type = ICMP_UNREACH;
                                code = ICMP_UNREACH_PROTOCOL;
                                break;
                        default:
                                return (-1);
                        }
                        break;
                default:
                        return (-1);
                }

                pf_patch_8(pd, &icmp6->icmp6_type, type, PF_HI);
                pf_patch_8(pd, &icmp6->icmp6_code, code, PF_LO);

                /* aligns well with a icmpv4 nextmtu */
                pf_patch_32(pd, &icmp6->icmp6_mtu, htonl(mtu));

                /* icmpv4 pptr is a one most significant byte */
                if (ptr >= 0)
                        pf_patch_32(pd, &icmp6->icmp6_pptr, htonl(ptr << 24));
                break;
        case AF_INET6:
                icmp4 = arg;
                type  = icmp4->icmp_type;
                code  = icmp4->icmp_code;
                mtu   = ntohs(icmp4->icmp_nextmtu);

                switch (type) {
                case ICMP_ECHO:
                        type = ICMP6_ECHO_REQUEST;
                        break;
                case ICMP_ECHOREPLY:
                        type = ICMP6_ECHO_REPLY;
                        break;
                case ICMP_UNREACH:
                        type = ICMP6_DST_UNREACH;
                        switch (code) {
                        case ICMP_UNREACH_NET:
                        case ICMP_UNREACH_HOST:
                        case ICMP_UNREACH_NET_UNKNOWN:
                        case ICMP_UNREACH_HOST_UNKNOWN:
                        case ICMP_UNREACH_ISOLATED:
                        case ICMP_UNREACH_TOSNET:
                        case ICMP_UNREACH_TOSHOST:
                                code = ICMP6_DST_UNREACH_NOROUTE;
                                break;
                        case ICMP_UNREACH_PORT:
                                code = ICMP6_DST_UNREACH_NOPORT;
                                break;
                        case ICMP_UNREACH_NET_PROHIB:
                        case ICMP_UNREACH_HOST_PROHIB:
                        case ICMP_UNREACH_FILTER_PROHIB:
                        case ICMP_UNREACH_PRECEDENCE_CUTOFF:
                                code = ICMP6_DST_UNREACH_ADMIN;
                                break;
                        case ICMP_UNREACH_PROTOCOL:
                                type = ICMP6_PARAM_PROB;
                                code = ICMP6_PARAMPROB_NEXTHEADER;
                                ptr  = offsetof(struct ip6_hdr, ip6_nxt);
                                break;
                        case ICMP_UNREACH_NEEDFRAG:
                                type = ICMP6_PACKET_TOO_BIG;
                                code = 0;
                                mtu += 20;
                                break;
                        default:
                                return (-1);
                        }
                        break;
                case ICMP_TIMXCEED:
                        type = ICMP6_TIME_EXCEEDED;
                        break;
                case ICMP_PARAMPROB:
                        type = ICMP6_PARAM_PROB;
                        switch (code) {
                        case ICMP_PARAMPROB_ERRATPTR:
                                code = ICMP6_PARAMPROB_HEADER;
                                break;
                        case ICMP_PARAMPROB_LENGTH:
                                code = ICMP6_PARAMPROB_HEADER;
                                break;
                        default:
                                return (-1);
                        }

                        ptr = icmp4->icmp_pptr;
                        if (ptr == 0 || ptr == PTR_IP(ip_tos))
                                ; /* preserve */
                        else if (ptr == PTR_IP(ip_len) ||
                            ptr == PTR_IP(ip_len) + 1)
                                ptr = PTR_IP6(ip6_plen);
                        else if (ptr == PTR_IP(ip_ttl))
                                ptr = PTR_IP6(ip6_hlim);
                        else if (ptr == PTR_IP(ip_p))
                                ptr = PTR_IP6(ip6_nxt);
                        else if (ptr >= PTR_IP(ip_src) &&
                            ptr < PTR_IP(ip_dst))
                                ptr = PTR_IP6(ip6_src);
                        else if (ptr >= PTR_IP(ip_dst) &&
                            ptr < sizeof(struct ip))
                                ptr = PTR_IP6(ip6_dst);
                        else {
                                return (-1);
                        }
                        break;
                default:
                        return (-1);
                }

                pf_patch_8(pd, &icmp4->icmp_type, type, PF_HI);
                pf_patch_8(pd, &icmp4->icmp_code, code, PF_LO);
                pf_patch_16(pd, &icmp4->icmp_nextmtu, htons(mtu));
                if (ptr >= 0)
                        pf_patch_32(pd, &icmp4->icmp_void, htonl(ptr));
                break;
        }

        return (0);
}
#endif /* INET6 */

/*
 * Need to modulate the sequence numbers in the TCP SACK option
 * (credits to Krzysztof Pfaff for report and patch)
 */
int
pf_modulate_sack(struct pf_pdesc *pd, struct pf_state_peer *dst)
{
        struct sackblk   sack;
        int              copyback = 0, i;
        int              olen, optsoff;
        u_int8_t         opts[MAX_TCPOPTLEN], *opt, *eoh;

        olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr);
        optsoff = pd->off + sizeof(struct tcphdr);
#define TCPOLEN_MINSACK (TCPOLEN_SACK + 2)
        if (olen < TCPOLEN_MINSACK ||
            !pf_pull_hdr(pd->m, optsoff, opts, olen, NULL, pd->af))
                return (0);

        eoh = opts + olen;
        opt = opts;
        while ((opt = pf_find_tcpopt(opt, opts, olen,
                    TCPOPT_SACK, TCPOLEN_MINSACK)) != NULL)
        {
                size_t safelen = MIN(opt[1], (eoh - opt));
                for (i = 2; i + TCPOLEN_SACK <= safelen; i += TCPOLEN_SACK) {
                        size_t startoff = (opt + i) - opts;
                        memcpy(&sack, &opt[i], sizeof(sack));
                        pf_patch_32_unaligned(pd, &sack.start,
                            htonl(ntohl(sack.start) - dst->seqdiff),
                            PF_ALGNMNT(startoff));
                        pf_patch_32_unaligned(pd, &sack.end,
                            htonl(ntohl(sack.end) - dst->seqdiff),
                            PF_ALGNMNT(startoff + sizeof(sack.start)));
                        memcpy(&opt[i], &sack, sizeof(sack));
                }
                copyback = 1;
                opt += opt[1];
        }

        if (copyback)
                m_copyback(pd->m, optsoff, olen, opts, M_NOWAIT);
        return (copyback);
}

struct mbuf *
pf_build_tcp(const struct pf_rule *r, sa_family_t af,
    const struct pf_addr *saddr, const struct pf_addr *daddr,
    u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack,
    u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag,
    u_int16_t rtag, u_int sack, u_int rdom, u_short *reason)
{
        struct mbuf     *m;
        int              len, tlen;
        struct ip       *h;
#ifdef INET6
        struct ip6_hdr  *h6;
#endif /* INET6 */
        struct tcphdr   *th;
        char            *opt;

        /* maximum segment size tcp option */
        tlen = sizeof(struct tcphdr);
        if (mss)
                tlen += 4;
        if (sack)
                tlen += 2;

        switch (af) {
        case AF_INET:
                len = sizeof(struct ip) + tlen;
                break;
#ifdef INET6
        case AF_INET6:
                len = sizeof(struct ip6_hdr) + tlen;
                break;
#endif /* INET6 */
        default:
                unhandled_af(af);
        }

        /* create outgoing mbuf */
        m = m_gethdr(M_DONTWAIT, MT_HEADER);
        if (m == NULL) {
                REASON_SET(reason, PFRES_MEMORY);
                return (NULL);
        }
        if (tag)
                m->m_pkthdr.pf.flags |= PF_TAG_GENERATED;
        m->m_pkthdr.pf.tag = rtag;
        m->m_pkthdr.ph_rtableid = rdom;
        if (r && (r->scrub_flags & PFSTATE_SETPRIO))
                m->m_pkthdr.pf.prio = r->set_prio[0];
        if (r && r->qid)
                m->m_pkthdr.pf.qid = r->qid;
        m->m_data += max_linkhdr;
        m->m_pkthdr.len = m->m_len = len;
        m->m_pkthdr.ph_ifidx = 0;
        m->m_pkthdr.csum_flags |= M_TCP_CSUM_OUT;
        memset(m->m_data, 0, len);
        switch (af) {
        case AF_INET:
                h = mtod(m, struct ip *);
                h->ip_p = IPPROTO_TCP;
                h->ip_len = htons(tlen);
                h->ip_v = 4;
                h->ip_hl = sizeof(*h) >> 2;
                h->ip_tos = IPTOS_LOWDELAY;
                h->ip_len = htons(len);
                h->ip_off = htons(atomic_load_int(&ip_mtudisc) ? IP_DF : 0);
                h->ip_ttl = ttl ? ttl : atomic_load_int(&ip_defttl);
                h->ip_sum = 0;
                h->ip_src.s_addr = saddr->v4.s_addr;
                h->ip_dst.s_addr = daddr->v4.s_addr;

                th = (struct tcphdr *)((caddr_t)h + sizeof(struct ip));
                break;
#ifdef INET6
        case AF_INET6:
                h6 = mtod(m, struct ip6_hdr *);
                h6->ip6_nxt = IPPROTO_TCP;
                h6->ip6_plen = htons(tlen);
                h6->ip6_vfc |= IPV6_VERSION;
                h6->ip6_hlim = IPV6_DEFHLIM;
                memcpy(&h6->ip6_src, &saddr->v6, sizeof(struct in6_addr));
                memcpy(&h6->ip6_dst, &daddr->v6, sizeof(struct in6_addr));

                th = (struct tcphdr *)((caddr_t)h6 + sizeof(struct ip6_hdr));
                break;
#endif /* INET6 */
        default:
                unhandled_af(af);
        }

        /* TCP header */
        th->th_sport = sport;
        th->th_dport = dport;
        th->th_seq = htonl(seq);
        th->th_ack = htonl(ack);
        th->th_off = tlen >> 2;
        th->th_flags = flags;
        th->th_win = htons(win);

        opt = (char *)(th + 1);
        if (mss) {
                opt[0] = TCPOPT_MAXSEG;
                opt[1] = 4;
                mss = htons(mss);
                memcpy((opt + 2), &mss, 2);
                opt += 4;
        }
        if (sack) {
                opt[0] = TCPOPT_SACK_PERMITTED;
                opt[1] = 2;
                opt += 2;
        }

        return (m);
}

void
pf_send_tcp(const struct pf_rule *r, sa_family_t af,
    const struct pf_addr *saddr, const struct pf_addr *daddr,
    u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack,
    u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag,
    u_int16_t rtag, u_int rdom, u_short *reason)
{
        struct mbuf     *m;

        if ((m = pf_build_tcp(r, af, saddr, daddr, sport, dport, seq, ack,
            flags, win, mss, ttl, tag, rtag, 0, rdom, reason)) == NULL)
                return;

        switch (af) {
        case AF_INET:
                ip_send(m);
                break;
#ifdef INET6
        case AF_INET6:
                ip6_send(m);
                break;
#endif /* INET6 */
        }
}

static void
pf_send_challenge_ack(struct pf_pdesc *pd, struct pf_state *st,
    struct pf_state_peer *src, struct pf_state_peer *dst, u_short *reason)
{
        /*
         * We are sending challenge ACK as a response to SYN packet, which
         * matches existing state (modulo TCP window check). Therefore packet
         * must be sent on behalf of destination.
         *
         * We expect sender to remain either silent, or send RST packet
         * so both, firewall and remote peer, can purge dead state from
         * memory.
         */
        pf_send_tcp(st->rule.ptr, pd->af, pd->dst, pd->src,
            pd->hdr.tcp.th_dport, pd->hdr.tcp.th_sport, dst->seqlo,
            src->seqlo, TH_ACK, 0, 0, st->rule.ptr->return_ttl, 1, 0,
            pd->rdomain, reason);
}

void
pf_send_icmp(struct mbuf *m, u_int8_t type, u_int8_t code, int param,
    sa_family_t af, struct pf_rule *r, u_int rdomain)
{
        struct mbuf     *m0;

        if ((m0 = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL)
                return;

        m0->m_pkthdr.pf.flags |= PF_TAG_GENERATED;
        m0->m_pkthdr.ph_rtableid = rdomain;
        if (r && (r->scrub_flags & PFSTATE_SETPRIO))
                m0->m_pkthdr.pf.prio = r->set_prio[0];
        if (r && r->qid)
                m0->m_pkthdr.pf.qid = r->qid;

        switch (af) {
        case AF_INET:
                icmp_error(m0, type, code, 0, param);
                break;
#ifdef INET6
        case AF_INET6:
                icmp6_error(m0, type, code, param);
                break;
#endif /* INET6 */
        }
}

/*
 * Return ((n = 0) == (a = b [with mask m]))
 * Note: n != 0 => returns (a != b [with mask m])
 */
int
pf_match_addr(u_int8_t n, struct pf_addr *a, struct pf_addr *m,
    struct pf_addr *b, sa_family_t af)
{
        switch (af) {
        case AF_INET:
                if ((a->addr32[0] & m->addr32[0]) ==
                    (b->addr32[0] & m->addr32[0]))
                        return (n == 0);
                break;
#ifdef INET6
        case AF_INET6:
                if (((a->addr32[0] & m->addr32[0]) ==
                     (b->addr32[0] & m->addr32[0])) &&
                    ((a->addr32[1] & m->addr32[1]) ==
                     (b->addr32[1] & m->addr32[1])) &&
                    ((a->addr32[2] & m->addr32[2]) ==
                     (b->addr32[2] & m->addr32[2])) &&
                    ((a->addr32[3] & m->addr32[3]) ==
                     (b->addr32[3] & m->addr32[3])))
                        return (n == 0);
                break;
#endif /* INET6 */
        }

        return (n != 0);
}

/*
 * Return 1 if b <= a <= e, otherwise return 0.
 */
int
pf_match_addr_range(struct pf_addr *b, struct pf_addr *e,
    struct pf_addr *a, sa_family_t af)
{
        switch (af) {
        case AF_INET:
                if ((ntohl(a->addr32[0]) < ntohl(b->addr32[0])) ||
                    (ntohl(a->addr32[0]) > ntohl(e->addr32[0])))
                        return (0);
                break;
#ifdef INET6
        case AF_INET6: {
                int     i;

                /* check a >= b */
                for (i = 0; i < 4; ++i)
                        if (ntohl(a->addr32[i]) > ntohl(b->addr32[i]))
                                break;
                        else if (ntohl(a->addr32[i]) < ntohl(b->addr32[i]))
                                return (0);
                /* check a <= e */
                for (i = 0; i < 4; ++i)
                        if (ntohl(a->addr32[i]) < ntohl(e->addr32[i]))
                                break;
                        else if (ntohl(a->addr32[i]) > ntohl(e->addr32[i]))
                                return (0);
                break;
        }
#endif /* INET6 */
        }
        return (1);
}

int
pf_match(u_int8_t op, u_int32_t a1, u_int32_t a2, u_int32_t p)
{
        switch (op) {
        case PF_OP_IRG:
                return ((p > a1) && (p < a2));
        case PF_OP_XRG:
                return ((p < a1) || (p > a2));
        case PF_OP_RRG:
                return ((p >= a1) && (p <= a2));
        case PF_OP_EQ:
                return (p == a1);
        case PF_OP_NE:
                return (p != a1);
        case PF_OP_LT:
                return (p < a1);
        case PF_OP_LE:
                return (p <= a1);
        case PF_OP_GT:
                return (p > a1);
        case PF_OP_GE:
                return (p >= a1);
        }
        return (0); /* never reached */
}

int
pf_match_port(u_int8_t op, u_int16_t a1, u_int16_t a2, u_int16_t p)
{
        return (pf_match(op, ntohs(a1), ntohs(a2), ntohs(p)));
}

int
pf_match_uid(u_int8_t op, uid_t a1, uid_t a2, uid_t u)
{
        if (u == -1 && op != PF_OP_EQ && op != PF_OP_NE)
                return (0);
        return (pf_match(op, a1, a2, u));
}

int
pf_match_gid(u_int8_t op, gid_t a1, gid_t a2, gid_t g)
{
        if (g == -1 && op != PF_OP_EQ && op != PF_OP_NE)
                return (0);
        return (pf_match(op, a1, a2, g));
}

int
pf_match_tag(struct mbuf *m, struct pf_rule *r, int *tag)
{
        if (*tag == -1)
                *tag = m->m_pkthdr.pf.tag;

        return ((!r->match_tag_not && r->match_tag == *tag) ||
            (r->match_tag_not && r->match_tag != *tag));
}

int
pf_match_rcvif(struct mbuf *m, struct pf_rule *r)
{
        struct ifnet *ifp;
        struct pfi_kif *kif = NULL;

        if (m->m_pkthdr.ph_ifidx == 0)
                return (0);

        smr_read_enter();
        ifp = if_get_smr(m->m_pkthdr.ph_ifidx);
        if (ifp != NULL) {
                kif = (struct pfi_kif *)ifp->if_pf_kif;
#if NCARP > 0
                if (ifp->if_type == IFT_CARP) {
                        struct ifnet *ifp0 = if_get_smr(ifp->if_carpdevidx);
                        if (ifp0 != NULL)
                                kif = (struct pfi_kif *)ifp0->if_pf_kif;
                }
#endif /* NCARP */
        }
        smr_read_leave();

        if (kif == NULL) {
                DPFPRINTF(LOG_ERR,
                    "%s: kif == NULL, @%d via %s", __func__,
                    r->nr, r->rcv_ifname);
                return (0);
        }

        return (pfi_kif_match(r->rcv_kif, kif));
}

void
pf_tag_packet(struct mbuf *m, int tag, int rtableid)
{
        if (tag > 0)
                m->m_pkthdr.pf.tag = tag;
        if (rtableid >= 0)
                m->m_pkthdr.ph_rtableid = (u_int)rtableid;
}

void
pf_anchor_stack_init(void)
{
        struct pf_anchor_stackframe *stack;

        stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
        stack[PF_ANCHOR_STACK_MAX].sf_stack_top = &stack[0];
        cpumem_leave(pf_anchor_stack, stack);
}

int
pf_anchor_stack_is_full(struct pf_anchor_stackframe *sf)
{
        struct pf_anchor_stackframe *stack;
        int rv;

        stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
        rv = (sf == &stack[PF_ANCHOR_STACK_MAX]);
        cpumem_leave(pf_anchor_stack, stack);

        return (rv);
}

int
pf_anchor_stack_is_empty(struct pf_anchor_stackframe *sf)
{
        struct pf_anchor_stackframe *stack;
        int rv;

        stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
        rv = (sf == &stack[0]);
        cpumem_leave(pf_anchor_stack, stack);

        return (rv);
}

struct pf_anchor_stackframe *
pf_anchor_stack_top(void)
{
        struct pf_anchor_stackframe *stack;
        struct pf_anchor_stackframe *top_sf;

        stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
        top_sf = stack[PF_ANCHOR_STACK_MAX].sf_stack_top;
        cpumem_leave(pf_anchor_stack, stack);

        return (top_sf);
}

int
pf_anchor_stack_push(struct pf_ruleset *rs, struct pf_rule *anchor,
    struct pf_rule *r, struct pf_anchor *child, int jump_target)
{
        struct pf_anchor_stackframe *stack;
        struct pf_anchor_stackframe *top_sf = pf_anchor_stack_top();

        top_sf++;
        if (pf_anchor_stack_is_full(top_sf))
                return (-1);

        top_sf->sf_rs = rs;
        top_sf->sf_anchor = anchor;
        top_sf->sf_r = r;
        top_sf->sf_child = child;
        top_sf->sf_jump_target = jump_target;

        stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);

        if ((top_sf <= &stack[0]) || (top_sf >= &stack[PF_ANCHOR_STACK_MAX]))
                panic("%s: top frame outside of anchor stack range", __func__);

        stack[PF_ANCHOR_STACK_MAX].sf_stack_top = top_sf;
        cpumem_leave(pf_anchor_stack, stack);

        return (0);
}

int
pf_anchor_stack_pop(struct pf_ruleset **rs, struct pf_rule **anchor,
    struct pf_rule **r, struct pf_anchor **child, int *jump_target)
{
        struct pf_anchor_stackframe *top_sf = pf_anchor_stack_top();
        struct pf_anchor_stackframe *stack;
        int on_top;

        stack = (struct pf_anchor_stackframe *)cpumem_enter(pf_anchor_stack);
        if (pf_anchor_stack_is_empty(top_sf)) {
                on_top = -1;
        } else {
                if ((top_sf <= &stack[0]) ||
                    (top_sf >= &stack[PF_ANCHOR_STACK_MAX]))
                        panic("%s: top frame outside of anchor stack range",
                            __func__);

                *rs = top_sf->sf_rs;
                *anchor = top_sf->sf_anchor;
                *r = top_sf->sf_r;
                *child = top_sf->sf_child;
                *jump_target = top_sf->sf_jump_target;
                top_sf--;
                stack[PF_ANCHOR_STACK_MAX].sf_stack_top = top_sf;
                on_top = 0;
        }
        cpumem_leave(pf_anchor_stack, stack);

        return (on_top);
}

void
pf_poolmask(struct pf_addr *naddr, struct pf_addr *raddr,
    struct pf_addr *rmask, struct pf_addr *saddr, sa_family_t af)
{
        switch (af) {
        case AF_INET:
                naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) |
                ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]);
                break;
#ifdef INET6
        case AF_INET6:
                naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) |
                ((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]);
                naddr->addr32[1] = (raddr->addr32[1] & rmask->addr32[1]) |
                ((rmask->addr32[1] ^ 0xffffffff ) & saddr->addr32[1]);
                naddr->addr32[2] = (raddr->addr32[2] & rmask->addr32[2]) |
                ((rmask->addr32[2] ^ 0xffffffff ) & saddr->addr32[2]);
                naddr->addr32[3] = (raddr->addr32[3] & rmask->addr32[3]) |
                ((rmask->addr32[3] ^ 0xffffffff ) & saddr->addr32[3]);
                break;
#endif /* INET6 */
        default:
                unhandled_af(af);
        }
}

void
pf_addr_inc(struct pf_addr *addr, sa_family_t af)
{
        switch (af) {
        case AF_INET:
                addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1);
                break;
#ifdef INET6
        case AF_INET6:
                if (addr->addr32[3] == 0xffffffff) {
                        addr->addr32[3] = 0;
                        if (addr->addr32[2] == 0xffffffff) {
                                addr->addr32[2] = 0;
                                if (addr->addr32[1] == 0xffffffff) {
                                        addr->addr32[1] = 0;
                                        addr->addr32[0] =
                                            htonl(ntohl(addr->addr32[0]) + 1);
                                } else
                                        addr->addr32[1] =
                                            htonl(ntohl(addr->addr32[1]) + 1);
                        } else
                                addr->addr32[2] =
                                    htonl(ntohl(addr->addr32[2]) + 1);
                } else
                        addr->addr32[3] =
                            htonl(ntohl(addr->addr32[3]) + 1);
                break;
#endif /* INET6 */
        default:
                unhandled_af(af);
        }
}

int
pf_socket_lookup(struct pf_pdesc *pd)
{
        struct pf_addr          *saddr, *daddr;
        u_int16_t                sport, dport;
        struct inpcbtable       *table;
        struct inpcb            *inp;

        pd->lookup.uid = -1;
        pd->lookup.gid = -1;
        pd->lookup.pid = NO_PID;
        switch (pd->virtual_proto) {
        case IPPROTO_TCP:
                sport = pd->hdr.tcp.th_sport;
                dport = pd->hdr.tcp.th_dport;
                PF_ASSERT_LOCKED();
                NET_ASSERT_LOCKED();
                table = &tcbtable;
                break;
        case IPPROTO_UDP:
                sport = pd->hdr.udp.uh_sport;
                dport = pd->hdr.udp.uh_dport;
                PF_ASSERT_LOCKED();
                NET_ASSERT_LOCKED();
                table = &udbtable;
                break;
        default:
                return (-1);
        }
        if (pd->dir == PF_IN) {
                saddr = pd->src;
                daddr = pd->dst;
        } else {
                u_int16_t       p;

                p = sport;
                sport = dport;
                dport = p;
                saddr = pd->dst;
                daddr = pd->src;
        }
        switch (pd->af) {
        case AF_INET:
                /*
                 * Fails when rtable is changed while evaluating the ruleset
                 * The socket looked up will not match the one hit in the end.
                 */
                inp = in_pcblookup(table, saddr->v4, sport, daddr->v4, dport,
                    pd->rdomain);
                if (inp == NULL) {
                        inp = in_pcblookup_listen(table, daddr->v4, dport,
                            NULL, pd->rdomain);
                        if (inp == NULL)
                                return (-1);
                }
                break;
#ifdef INET6
        case AF_INET6:
                if (pd->virtual_proto == IPPROTO_UDP)
                        table = &udb6table;
                if (pd->virtual_proto == IPPROTO_TCP)
                        table = &tcb6table;
                inp = in6_pcblookup(table, &saddr->v6, sport, &daddr->v6,
                    dport, pd->rdomain);
                if (inp == NULL) {
                        inp = in6_pcblookup_listen(table, &daddr->v6, dport,
                            NULL, pd->rdomain);
                        if (inp == NULL)
                                return (-1);
                }
                break;
#endif /* INET6 */
        default:
                unhandled_af(pd->af);
        }
        pd->lookup.uid = inp->inp_socket->so_euid;
        pd->lookup.gid = inp->inp_socket->so_egid;
        pd->lookup.pid = inp->inp_socket->so_cpid;
        in_pcbunref(inp);
        return (1);
}

/* post: r  => (r[0] == type /\ r[1] >= min_typelen >= 2  "validity"
 *                      /\ (eoh - r) >= min_typelen >= 2  "safety"  )
 *
 * warning: r + r[1] may exceed opts bounds for r[1] > min_typelen
 */
u_int8_t*
pf_find_tcpopt(u_int8_t *opt, u_int8_t *opts, size_t hlen, u_int8_t type,
    u_int8_t min_typelen)
{
        u_int8_t *eoh = opts + hlen;

        if (min_typelen < 2)
                return (NULL);

        while ((eoh - opt) >= min_typelen) {
                switch (*opt) {
                case TCPOPT_EOL:
                        /* FALLTHROUGH - Workaround the failure of some
                           systems to NOP-pad their bzero'd option buffers,
                           producing spurious EOLs */
                case TCPOPT_NOP:
                        opt++;
                        continue;
                default:
                        if (opt[0] == type &&
                            opt[1] >= min_typelen)
                                return (opt);
                }

                opt += MAX(opt[1], 2); /* evade infinite loops */
        }

        return (NULL);
}

u_int8_t
pf_get_wscale(struct pf_pdesc *pd)
{
        int              olen;
        u_int8_t         opts[MAX_TCPOPTLEN], *opt;
        u_int8_t         wscale = 0;

        olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr);
        if (olen < TCPOLEN_WINDOW || !pf_pull_hdr(pd->m,
            pd->off + sizeof(struct tcphdr), opts, olen, NULL, pd->af))
                return (0);

        opt = opts;
        while ((opt = pf_find_tcpopt(opt, opts, olen,
                    TCPOPT_WINDOW, TCPOLEN_WINDOW)) != NULL) {
                wscale = opt[2];
                wscale = MIN(wscale, TCP_MAX_WINSHIFT);
                wscale |= PF_WSCALE_FLAG;

                opt += opt[1];
        }

        return (wscale);
}

u_int16_t
pf_get_mss(struct pf_pdesc *pd, uint16_t mssdflt)
{
        int              olen;
        u_int8_t         opts[MAX_TCPOPTLEN], *opt;
        u_int16_t        mss;

        olen = (pd->hdr.tcp.th_off << 2) - sizeof(struct tcphdr);
        if (olen < TCPOLEN_MAXSEG || !pf_pull_hdr(pd->m,
            pd->off + sizeof(struct tcphdr), opts, olen, NULL, pd->af))
                return (0);

        mss = mssdflt;
        opt = opts;
        while ((opt = pf_find_tcpopt(opt, opts, olen,
                    TCPOPT_MAXSEG, TCPOLEN_MAXSEG)) != NULL) {
                        memcpy(&mss, (opt + 2), 2);
                        mss = ntohs(mss);

                        opt += opt[1];
        }
        return (mss);
}

u_int16_t
pf_calc_mss(struct pf_addr *addr, sa_family_t af, int rtableid, uint16_t offer,
    uint16_t mssdflt)
{
        struct ifnet            *ifp;
        struct sockaddr_in      *dst;
#ifdef INET6
        struct sockaddr_in6     *dst6;
#endif /* INET6 */
        struct rtentry          *rt = NULL;
        struct sockaddr_storage  ss;
        int                      hlen, mss;

        memset(&ss, 0, sizeof(ss));

        switch (af) {
        case AF_INET:
                hlen = sizeof(struct ip);
                dst = (struct sockaddr_in *)&ss;
                dst->sin_family = AF_INET;
                dst->sin_len = sizeof(*dst);
                dst->sin_addr = addr->v4;
                rt = rtalloc(sintosa(dst), 0, rtableid);
                break;
#ifdef INET6
        case AF_INET6:
                hlen = sizeof(struct ip6_hdr);
                dst6 = (struct sockaddr_in6 *)&ss;
                dst6->sin6_family = AF_INET6;
                dst6->sin6_len = sizeof(*dst6);
                dst6->sin6_addr = addr->v6;
                rt = rtalloc(sin6tosa(dst6), 0, rtableid);
                break;
#endif /* INET6 */
        }

        mss = mssdflt;
        if (rt != NULL && (ifp = if_get(rt->rt_ifidx)) != NULL) {
                mss = ifp->if_mtu - hlen - sizeof(struct tcphdr);
                mss = imax(mss, mssdflt);
                if_put(ifp);
        }
        rtfree(rt);
        mss = imin(mss, offer);
        mss = imax(mss, 64);            /* sanity - at least max opt space */
        return (mss);
}

static __inline int
pf_set_rt_ifp(struct pf_state *st, struct pf_addr *saddr, sa_family_t af,
    struct pf_src_node **sns)
{
        struct pf_rule *r = st->rule.ptr;
        int     rv;

        if (!r->rt)
                return (0);

        rv = pf_map_addr(af, r, saddr, &st->rt_addr, NULL, sns,
            &r->route, PF_SN_ROUTE);
        if (rv == 0)
                st->rt = r->rt;

        return (rv);
}

u_int32_t
pf_tcp_iss(struct pf_pdesc *pd)
{
        SHA2_CTX ctx;
        union {
                uint8_t bytes[SHA512_DIGEST_LENGTH];
                uint32_t words[1];
        } digest;

        if (pf_tcp_secret_init == 0) {
                arc4random_buf(pf_tcp_secret, sizeof(pf_tcp_secret));
                SHA512Init(&pf_tcp_secret_ctx);
                SHA512Update(&pf_tcp_secret_ctx, pf_tcp_secret,
                    sizeof(pf_tcp_secret));
                pf_tcp_secret_init = 1;
        }
        ctx = pf_tcp_secret_ctx;

        SHA512Update(&ctx, &pd->rdomain, sizeof(pd->rdomain));
        SHA512Update(&ctx, &pd->hdr.tcp.th_sport, sizeof(u_short));
        SHA512Update(&ctx, &pd->hdr.tcp.th_dport, sizeof(u_short));
        switch (pd->af) {
        case AF_INET:
                SHA512Update(&ctx, &pd->src->v4, sizeof(struct in_addr));
                SHA512Update(&ctx, &pd->dst->v4, sizeof(struct in_addr));
                break;
#ifdef INET6
        case AF_INET6:
                SHA512Update(&ctx, &pd->src->v6, sizeof(struct in6_addr));
                SHA512Update(&ctx, &pd->dst->v6, sizeof(struct in6_addr));
                break;
#endif /* INET6 */
        }
        SHA512Final(digest.bytes, &ctx);
        pf_tcp_iss_off += 4096;
        return (digest.words[0] + READ_ONCE(tcp_iss) + pf_tcp_iss_off);
}

void
pf_rule_to_actions(struct pf_rule *r, struct pf_rule_actions *a)
{
        if (r->qid)
                a->qid = r->qid;
        if (r->pqid)
                a->pqid = r->pqid;
        if (r->rtableid >= 0)
                a->rtableid = r->rtableid;
#if NPFLOG > 0
        a->log |= r->log;
#endif  /* NPFLOG > 0 */
        if (r->scrub_flags & PFSTATE_SETTOS)
                a->set_tos = r->set_tos;
        if (r->min_ttl)
                a->min_ttl = r->min_ttl;
        if (r->max_mss)
                a->max_mss = r->max_mss;
        a->flags |= (r->scrub_flags & (PFSTATE_NODF|PFSTATE_RANDOMID|
            PFSTATE_SETTOS|PFSTATE_SCRUB_TCP|PFSTATE_SETPRIO));
        if (r->scrub_flags & PFSTATE_SETPRIO) {
                a->set_prio[0] = r->set_prio[0];
                a->set_prio[1] = r->set_prio[1];
        }
        if (r->rule_flag & PFRULE_SETDELAY)
                a->delay = r->delay;
}

#define PF_TEST_ATTRIB(t, a)                    \
        if (t) {                                \
                r = a;                          \
                continue;                       \
        } else do {                             \
        } while (0)

enum pf_test_status
pf_match_rule(struct pf_test_ctx *ctx, struct pf_ruleset *ruleset)
{
        struct pf_rule *r;
        struct pf_anchor *child = NULL;
        int target;

        pf_anchor_stack_init();
enter_ruleset:
        r = TAILQ_FIRST(ruleset->rules.active.ptr);
        while (r != NULL) {
                struct pf_statelim *stlim = NULL;
                struct pf_sourcelim *srlim = NULL;
                struct pf_source *sr = NULL;
                unsigned int gen;

                PF_TEST_ATTRIB(r->rule_flag & PFRULE_EXPIRED,
                    TAILQ_NEXT(r, entries));
                r->evaluations++;
                PF_TEST_ATTRIB(
                    (pfi_kif_match(r->kif, ctx->pd->kif) == r->ifnot),
                        r->skip[PF_SKIP_IFP].ptr);
                PF_TEST_ATTRIB((r->direction && r->direction != ctx->pd->dir),
                        r->skip[PF_SKIP_DIR].ptr);
                PF_TEST_ATTRIB((r->onrdomain >= 0  &&
                    (r->onrdomain == ctx->pd->rdomain) == r->ifnot),
                        r->skip[PF_SKIP_RDOM].ptr);
                PF_TEST_ATTRIB((r->af && r->af != ctx->pd->af),
                        r->skip[PF_SKIP_AF].ptr);
                PF_TEST_ATTRIB((r->proto && r->proto != ctx->pd->proto),
                        r->skip[PF_SKIP_PROTO].ptr);
                PF_TEST_ATTRIB((PF_MISMATCHAW(&r->src.addr, &ctx->pd->nsaddr,
                    ctx->pd->naf, r->src.neg, ctx->pd->kif,
                    ctx->act.rtableid)),
                        r->skip[PF_SKIP_SRC_ADDR].ptr);
                PF_TEST_ATTRIB((PF_MISMATCHAW(&r->dst.addr, &ctx->pd->ndaddr,
                    ctx->pd->af, r->dst.neg, NULL, ctx->act.rtableid)),
                        r->skip[PF_SKIP_DST_ADDR].ptr);

                switch (ctx->pd->virtual_proto) {
                case PF_VPROTO_FRAGMENT:
                        /* tcp/udp only. port_op always 0 in other cases */
                        PF_TEST_ATTRIB((r->src.port_op || r->dst.port_op),
                                TAILQ_NEXT(r, entries));
                        PF_TEST_ATTRIB((ctx->pd->proto == IPPROTO_TCP &&
                            r->flagset),
                                TAILQ_NEXT(r, entries));
                        /* icmp only. type/code always 0 in other cases */
                        PF_TEST_ATTRIB((r->type || r->code),
                                TAILQ_NEXT(r, entries));
                        /* tcp/udp only. {uid|gid}.op always 0 in other cases */
                        PF_TEST_ATTRIB((r->gid.op || r->uid.op),
                                TAILQ_NEXT(r, entries));
                        break;

                case IPPROTO_TCP:
                        PF_TEST_ATTRIB(((r->flagset & ctx->th->th_flags) !=
                            r->flags),
                                TAILQ_NEXT(r, entries));
                        PF_TEST_ATTRIB((r->os_fingerprint != PF_OSFP_ANY &&
                            !pf_osfp_match(pf_osfp_fingerprint(ctx->pd),
                            r->os_fingerprint)),
                                TAILQ_NEXT(r, entries));
                        /* FALLTHROUGH */

                case IPPROTO_UDP:
                        /* tcp/udp only. port_op always 0 in other cases */
                        PF_TEST_ATTRIB((r->src.port_op &&
                            !pf_match_port(r->src.port_op, r->src.port[0],
                            r->src.port[1], ctx->pd->nsport)),
                                r->skip[PF_SKIP_SRC_PORT].ptr);
                        PF_TEST_ATTRIB((r->dst.port_op &&
                            !pf_match_port(r->dst.port_op, r->dst.port[0],
                            r->dst.port[1], ctx->pd->ndport)),
                                r->skip[PF_SKIP_DST_PORT].ptr);
                        /* tcp/udp only. uid.op always 0 in other cases */
                        PF_TEST_ATTRIB((r->uid.op && (ctx->pd->lookup.done ||
                            (ctx->pd->lookup.done =
                            pf_socket_lookup(ctx->pd), 1)) &&
                            !pf_match_uid(r->uid.op, r->uid.uid[0],
                            r->uid.uid[1], ctx->pd->lookup.uid)),
                                TAILQ_NEXT(r, entries));
                        /* tcp/udp only. gid.op always 0 in other cases */
                        PF_TEST_ATTRIB((r->gid.op && (ctx->pd->lookup.done ||
                            (ctx->pd->lookup.done =
                            pf_socket_lookup(ctx->pd), 1)) &&
                            !pf_match_gid(r->gid.op, r->gid.gid[0],
                            r->gid.gid[1], ctx->pd->lookup.gid)),
                                TAILQ_NEXT(r, entries));
                        break;

                case IPPROTO_ICMP:
                        /* icmp only. type always 0 in other cases */
                        PF_TEST_ATTRIB((r->type &&
                            r->type != ctx->icmptype + 1),
                                TAILQ_NEXT(r, entries));
                        /* icmp only. type always 0 in other cases */
                        PF_TEST_ATTRIB((r->code &&
                            r->code != ctx->icmpcode + 1),
                                TAILQ_NEXT(r, entries));
                        /* icmp only. don't create states on replies */
                        PF_TEST_ATTRIB((r->keep_state && !ctx->state_icmp &&
                            (r->rule_flag & PFRULE_STATESLOPPY) == 0 &&
                            ctx->icmp_dir != PF_IN),
                                TAILQ_NEXT(r, entries));
                        break;

                case IPPROTO_ICMPV6:
                        /* icmp only. type always 0 in other cases */
                        PF_TEST_ATTRIB((r->type &&
                            r->type != ctx->icmptype + 1),
                                TAILQ_NEXT(r, entries));
                        /* icmp only. type always 0 in other cases */
                        PF_TEST_ATTRIB((r->code &&
                            r->code != ctx->icmpcode + 1),
                                TAILQ_NEXT(r, entries));
                        /* icmp only. don't create states on replies */
                        PF_TEST_ATTRIB((r->keep_state && !ctx->state_icmp &&
                            (r->rule_flag & PFRULE_STATESLOPPY) == 0 &&
                            ctx->icmp_dir != PF_IN &&
                            ctx->icmptype != ND_NEIGHBOR_ADVERT),
                                TAILQ_NEXT(r, entries));
                        break;

                default:
                        break;
                }

                PF_TEST_ATTRIB((r->rule_flag & PFRULE_FRAGMENT &&
                    ctx->pd->virtual_proto != PF_VPROTO_FRAGMENT),
                        TAILQ_NEXT(r, entries));
                PF_TEST_ATTRIB((r->tos && !(r->tos == ctx->pd->tos)),
                        TAILQ_NEXT(r, entries));
                PF_TEST_ATTRIB((r->prob &&
                    r->prob <= arc4random_uniform(UINT_MAX - 1) + 1),
                        TAILQ_NEXT(r, entries));
                PF_TEST_ATTRIB((r->match_tag &&
                    !pf_match_tag(ctx->pd->m, r, &ctx->tag)),
                        TAILQ_NEXT(r, entries));
                PF_TEST_ATTRIB((r->rcv_kif && pf_match_rcvif(ctx->pd->m, r) ==
                    r->rcvifnot),
                        TAILQ_NEXT(r, entries));
                PF_TEST_ATTRIB((r->prio &&
                    (r->prio == PF_PRIO_ZERO ? 0 : r->prio) !=
                    ctx->pd->m->m_pkthdr.pf.prio),
                        TAILQ_NEXT(r, entries));

                if (r->statelim.id != PF_STATELIM_ID_NONE) {
                        stlim = pf_statelim_find(r->statelim.id);

                        /*
                         * Treat a missing limiter like an exhausted limiter.
                         * There is no "backend" to get a resource out of
                         * so the rule can't create state.
                         */
                        PF_TEST_ATTRIB(stlim == NULL,
                                TAILQ_NEXT(r, entries));

                        /*
                         * An overcommitted pool means this rule
                         * can't create state.
                         */
                        if (stlim->pfstlim_inuse >= stlim->pfstlim_limit) {
                                gen = pf_statelim_enter(stlim);
                                stlim->pfstlim_counters.hardlimited++;
                                pf_statelim_leave(stlim, gen);
                                if (r->statelim.limiter_action == PF_LIMITER_BLOCK) {
                                        ctx->limiter_drop = 1;
                                        REASON_SET(&ctx->reason, PFRES_MAXSTATES);
                                        break;  /* stop rule processing */
                                }

                                r = TAILQ_NEXT(r, entries);
                                continue;
                        }

                        /*
                         * Is access to the pool rate limited?
                         */
                        if (stlim->pfstlim_rate.limit != 0) {
                                uint64_t ts = getnsecuptime();
                                uint64_t diff = ts - stlim->pfstlim_rate_ts;

                                if (diff < stlim->pfstlim_rate_token) {
                                        gen = pf_statelim_enter(stlim);
                                        stlim->pfstlim_counters.ratelimited++;
                                        pf_statelim_leave(stlim, gen);
                                        if (r->statelim.limiter_action ==
                                            PF_LIMITER_BLOCK) {
                                                ctx->limiter_drop = 1;
                                                REASON_SET(&ctx->reason,
                                                    PFRES_MAXSTATES);
                                                /* stop rule processing */
                                                break;
                                        }
                                        r = TAILQ_NEXT(r, entries);
                                        continue;
                                }

                                if (diff > stlim->pfstlim_rate_bucket) {
                                        stlim->pfstlim_rate_ts =
                                            ts - stlim->pfstlim_rate_bucket;
                                }
                        }
                }

                if (r->sourcelim.id != PF_SOURCELIM_ID_NONE) {
                        struct pf_source key;

                        srlim = pf_sourcelim_find(r->sourcelim.id);

                        /*
                         * Treat a missing pool like an overcommitted pool.
                         * There is no "backend" to get a resource out of
                         * so the rule can't create state.
                         */
                        PF_TEST_ATTRIB(srlim == NULL,
                                TAILQ_NEXT(r, entries));

                        pf_source_key(srlim, &key,
                            ctx->pd->af, ctx->pd->rdomain, ctx->pd->src);
                        sr = pf_source_find(srlim, &key);
                        if (sr != NULL) {
                                /*
                                 * An overcommitted limiter means this rule
                                 * can't create state.
                                 */
                                if (sr->pfsr_inuse >= srlim->pfsrlim_limit) {
                                        sr->pfsr_counters.hardlimited++;
                                        gen = pf_sourcelim_enter(srlim);
                                        srlim->pfsrlim_counters.hardlimited++;
                                        pf_sourcelim_leave(srlim, gen);
                                        if (r->sourcelim.limiter_action ==
                                            PF_LIMITER_BLOCK) {
                                                ctx->limiter_drop = 1;
                                                REASON_SET(&ctx->reason,
                                                    PFRES_SRCLIMIT);
                                                /* stop rule processing */
                                                break;
                                        }
                                        r = TAILQ_NEXT(r, entries);
                                        continue;
                                }

                                /*
                                 * Is access to the pool rate limited?
                                 */
                                if (srlim->pfsrlim_rate.limit != 0) {
                                        uint64_t ts = getnsecuptime();
                                        uint64_t diff = ts - sr->pfsr_rate_ts;

                                        if (diff < srlim->pfsrlim_rate_token) {
                                                sr->pfsr_counters.ratelimited++;
                                                gen = pf_sourcelim_enter(srlim);
                                                srlim->pfsrlim_counters.ratelimited++;
                                                pf_sourcelim_leave(srlim, gen);
                                                if (r->sourcelim.limiter_action ==
                                                    PF_LIMITER_BLOCK) {
                                                        ctx->limiter_drop = 1;
                                                        REASON_SET(&ctx->reason,
                                                            PFRES_SRCLIMIT);
                                                        /* stop rules */
                                                        break;
                                                }
                                                r = TAILQ_NEXT(r, entries);
                                                continue;
                                        }

                                        if (diff > srlim->pfsrlim_rate_bucket) {
                                                sr->pfsr_rate_ts = ts -
                                                    srlim->pfsrlim_rate_bucket;
                                        }
                                }
                        } else {
                                /*
                                 * a new source entry will (should)
                                 * admit a state.
                                 */

                                if (srlim->pfsrlim_nsources >=
                                    srlim->pfsrlim_entries) {
                                        gen = pf_sourcelim_enter(srlim);
                                        srlim->pfsrlim_counters.addrlimited++;
                                        pf_sourcelim_leave(srlim, gen);
                                        if (r->sourcelim.limiter_action ==
                                            PF_LIMITER_BLOCK) {
                                                ctx->limiter_drop = 1;
                                                REASON_SET(&ctx->reason,
                                                            PFRES_SRCLIMIT);
                                                /* stop rules processing */
                                                break;
                                        }
                                        r = TAILQ_NEXT(r, entries);
                                        continue;
                                }
                        }
                }

                /* must be last! */
                if (r->pktrate.limit) {
                        pf_add_threshold(&r->pktrate);
                        PF_TEST_ATTRIB((pf_check_threshold(&r->pktrate)),
                                TAILQ_NEXT(r, entries));
                }

                /* FALLTHROUGH */
                if (r->tag)
                        ctx->tag = r->tag;
                if (r->anchor == NULL) {

                        if (r->rule_flag & PFRULE_ONCE) {
                                u_int32_t       rule_flag;

                                rule_flag = r->rule_flag;
                                if (((rule_flag & PFRULE_EXPIRED) == 0) &&
                                    atomic_cas_uint(&r->rule_flag, rule_flag,
                                    rule_flag | PFRULE_EXPIRED) == rule_flag) {
                                        r->exptime = gettime();
                                } else {
                                        r = TAILQ_NEXT(r, entries);
                                        continue;
                                }
                        }

                        if (r->action == PF_MATCH) {
                                if ((ctx->ri = pool_get(&pf_rule_item_pl,
                                    PR_NOWAIT)) == NULL) {
                                        REASON_SET(&ctx->reason, PFRES_MEMORY);
                                        return (PF_TEST_FAIL);
                                }
                                ctx->ri->r = r;
                                /* order is irrelevant */
                                SLIST_INSERT_HEAD(&ctx->rules, ctx->ri, entry);
                                ctx->ri = NULL;
                                pf_rule_to_actions(r, &ctx->act);
                                if (r->rule_flag & PFRULE_AFTO)
                                        ctx->pd->naf = r->naf;
                                if (pf_get_transaddr(r, ctx->pd, ctx->sns,
                                    &ctx->nr) == -1) {
                                        REASON_SET(&ctx->reason,
                                            PFRES_TRANSLATE);
                                        return (PF_TEST_FAIL);
                                }
#if NPFLOG > 0
                                if (r->log) {
                                        REASON_SET(&ctx->reason, PFRES_MATCH);
                                        pflog_packet(ctx->pd, ctx->reason, r,
                                            ctx->a, ruleset, NULL);
                                }
#endif  /* NPFLOG > 0 */
                        } else {
                                /*
                                 * found matching r
                                 */
                                *ctx->rm = r;
                                /*
                                 * anchor, with ruleset, where r belongs to
                                 */
                                *ctx->am = ctx->a;
                                /*
                                 * ruleset where r belongs to
                                 */
                                *ctx->rsm = ruleset;
                                /*
                                 * ruleset, where anchor belongs to.
                                 */
                                ctx->arsm = ctx->aruleset;
                                /*
                                 * state/source pools
                                 */

                                ctx->statelim = stlim;
                                ctx->sourcelim = srlim;
                                ctx->source = sr;
                        }

#if NPFLOG > 0
                        if (ctx->act.log & PF_LOG_MATCHES)
                                pf_log_matches(ctx->pd, r, ctx->a, ruleset,
                                    &ctx->rules);
#endif  /* NPFLOG > 0 */

                        if (r->quick)
                                return (PF_TEST_QUICK);
                } else {
                        ctx->aruleset = &r->anchor->ruleset;
                        if (r->anchor_wildcard) {
                                RB_FOREACH(child, pf_anchor_node,
                                    &r->anchor->children) {
                                        if (pf_anchor_stack_push(ruleset,
                                            ctx->a, r, child,
                                            PF_NEXT_CHILD) != 0)
                                                return (PF_TEST_FAIL);

                                        ctx->a = r;
                                        ruleset = &child->ruleset;
                                        goto enter_ruleset;
next_child:
                                        continue;       /* with RB_FOREACH() */
                                }
                        } else {
                                if (pf_anchor_stack_push(ruleset, ctx->a,
                                    r, child, PF_NEXT_RULE) != 0)
                                        return (PF_TEST_FAIL);

                                ctx->a = r;
                                ruleset = &r->anchor->ruleset;
                                child = NULL;
                                goto enter_ruleset;
next_rule:
                                ;
                        }
                }
                r = TAILQ_NEXT(r, entries);
        }

        if (pf_anchor_stack_pop(&ruleset, &ctx->a, &r, &child,
            &target) == 0) {

                /* stop if any rule matched within quick anchors. */
                if (r->quick && *ctx->am == r)
                        return (PF_TEST_QUICK);

                switch (target) {
                case PF_NEXT_CHILD:
                        goto next_child;
                case PF_NEXT_RULE:
                        goto next_rule;
                default:
                        panic("%s: unknown jump target", __func__);
                }
        }

        return (PF_TEST_OK);
}

int
pf_test_rule(struct pf_pdesc *pd, struct pf_rule **rm, struct pf_state **sm,
    struct pf_rule **am, struct pf_ruleset **rsm, u_short *reason)
{
        struct pf_rule          *r = NULL;
        struct pf_rule          *a = NULL;
        struct pf_ruleset       *ruleset = NULL;
        struct pf_state_key     *skw = NULL, *sks = NULL;
        int                      rewrite = 0;
        u_int16_t                virtual_type, virtual_id;
        int                      action = PF_DROP;
        struct pf_test_ctx       ctx;
        int                      rv;

        PF_ASSERT_LOCKED();

        memset(&ctx, 0, sizeof(ctx));
        ctx.pd = pd;
        ctx.rm = rm;
        ctx.am = am;
        ctx.rsm = rsm;
        ctx.th = &pd->hdr.tcp;
        ctx.act.rtableid = pd->rdomain;
        ctx.tag = -1;
        SLIST_INIT(&ctx.rules);

        if (pd->dir == PF_IN && if_congested()) {
                REASON_SET(&ctx.reason, PFRES_CONGEST);
                return (PF_DROP);
        }

        switch (pd->virtual_proto) {
        case IPPROTO_ICMP:
                ctx.icmptype = pd->hdr.icmp.icmp_type;
                ctx.icmpcode = pd->hdr.icmp.icmp_code;
                ctx.state_icmp = pf_icmp_mapping(pd, ctx.icmptype,
                    &ctx.icmp_dir, &virtual_id, &virtual_type);
                if (ctx.icmp_dir == PF_IN) {
                        pd->osport = pd->nsport = virtual_id;
                        pd->odport = pd->ndport = virtual_type;
                } else {
                        pd->osport = pd->nsport = virtual_type;
                        pd->odport = pd->ndport = virtual_id;
                }
                break;
#ifdef INET6
        case IPPROTO_ICMPV6:
                ctx.icmptype = pd->hdr.icmp6.icmp6_type;
                ctx.icmpcode = pd->hdr.icmp6.icmp6_code;
                ctx.state_icmp = pf_icmp_mapping(pd, ctx.icmptype,
                    &ctx.icmp_dir, &virtual_id, &virtual_type);
                if (ctx.icmp_dir == PF_IN) {
                        pd->osport = pd->nsport = virtual_id;
                        pd->odport = pd->ndport = virtual_type;
                } else {
                        pd->osport = pd->nsport = virtual_type;
                        pd->odport = pd->ndport = virtual_id;
                }
                break;
#endif /* INET6 */
        }

        ruleset = &pf_main_ruleset;
        rv = pf_match_rule(&ctx, ruleset);
        if (rv == PF_TEST_FAIL || ctx.limiter_drop == 1) {
                REASON_SET(reason, ctx.reason);
                goto cleanup;
        }

        r = *ctx.rm;    /* matching rule */
        a = *ctx.am;    /* rule that defines an anchor containing 'r' */
        ruleset = *ctx.rsm;/* ruleset of the anchor defined by the rule 'a' */
        ctx.aruleset = ctx.arsm;/* ruleset of the 'a' rule itself */

        /* apply actions for last matching pass/block rule */
        pf_rule_to_actions(r, &ctx.act);
        if (r->rule_flag & PFRULE_AFTO)
                pd->naf = r->naf;
        if (pf_get_transaddr(r, pd, ctx.sns, &ctx.nr) == -1) {
                REASON_SET(&ctx.reason, PFRES_TRANSLATE);
                goto cleanup;
        }
        REASON_SET(&ctx.reason, PFRES_MATCH);

#if NPFLOG > 0
        if (r->log)
                pflog_packet(pd, ctx.reason, r, a, ruleset, NULL);
        if (ctx.act.log & PF_LOG_MATCHES)
                pf_log_matches(pd, r, a, ruleset, &ctx.rules);
#endif  /* NPFLOG > 0 */

        if (pd->virtual_proto != PF_VPROTO_FRAGMENT &&
            (r->action == PF_DROP) &&
            ((r->rule_flag & PFRULE_RETURNRST) ||
            (r->rule_flag & PFRULE_RETURNICMP) ||
            (r->rule_flag & PFRULE_RETURN))) {
                if (pd->proto == IPPROTO_TCP &&
                    ((r->rule_flag & PFRULE_RETURNRST) ||
                    (r->rule_flag & PFRULE_RETURN)) &&
                    !(ctx.th->th_flags & TH_RST)) {
                        u_int32_t        ack =
                            ntohl(ctx.th->th_seq) + pd->p_len;

                        if (pf_check_tcp_cksum(pd->m, pd->off,
                            pd->tot_len - pd->off, pd->af))
                                REASON_SET(&ctx.reason, PFRES_PROTCKSUM);
                        else {
                                if (ctx.th->th_flags & TH_SYN)
                                        ack++;
                                if (ctx.th->th_flags & TH_FIN)
                                        ack++;
                                pf_send_tcp(r, pd->af, pd->dst,
                                    pd->src, ctx.th->th_dport,
                                    ctx.th->th_sport, ntohl(ctx.th->th_ack),
                                    ack, TH_RST|TH_ACK, 0, 0, r->return_ttl,
                                    1, 0, pd->rdomain, &ctx.reason);
                        }
                } else if ((pd->proto != IPPROTO_ICMP ||
                    ICMP_INFOTYPE(ctx.icmptype)) && pd->af == AF_INET &&
                    r->return_icmp)
                        pf_send_icmp(pd->m, r->return_icmp >> 8,
                            r->return_icmp & 255, 0, pd->af, r, pd->rdomain);
                else if ((pd->proto != IPPROTO_ICMPV6 ||
                    (ctx.icmptype >= ICMP6_ECHO_REQUEST &&
                    ctx.icmptype != ND_REDIRECT)) && pd->af == AF_INET6 &&
                    r->return_icmp6)
                        pf_send_icmp(pd->m, r->return_icmp6 >> 8,
                            r->return_icmp6 & 255, 0, pd->af, r, pd->rdomain);
        }

        if (r->action == PF_DROP)
                goto cleanup;

        pf_tag_packet(pd->m, ctx.tag, ctx.act.rtableid);
        if (ctx.act.rtableid >= 0 &&
            rtable_l2(ctx.act.rtableid) != pd->rdomain)
                pd->destchg = 1;

        if (r->action == PF_PASS && pd->badopts != 0 && ! r->allow_opts) {
                REASON_SET(&ctx.reason, PFRES_IPOPTIONS);
#if NPFLOG > 0
                pd->pflog |= PF_LOG_FORCE;
#endif  /* NPFLOG > 0 */
                DPFPRINTF(LOG_NOTICE, "dropping packet with "
                    "ip/ipv6 options in pf_test_rule()");
                goto cleanup;
        }

        if (pd->virtual_proto != PF_VPROTO_FRAGMENT
            && !ctx.state_icmp && r->keep_state) {

                if (r->rule_flag & PFRULE_SRCTRACK &&
                    pf_insert_src_node(&ctx.sns[PF_SN_NONE], r, PF_SN_NONE,
                    pd->af, pd->src, NULL, NULL) != 0) {
                        REASON_SET(&ctx.reason, PFRES_SRCLIMIT);
                        goto cleanup;
                }

                if (r->max_states && (r->states_cur >= r->max_states)) {
                        pf_status.lcounters[LCNT_STATES]++;
                        REASON_SET(&ctx.reason, PFRES_MAXSTATES);
                        goto cleanup;
                }

                action = pf_create_state(pd, r, a, ctx.nr, &skw, &sks,
                    &rewrite, sm, ctx.tag, &ctx.rules, &ctx.act, ctx.sns,
                    &ctx);

                if (action != PF_PASS)
                        goto cleanup;

                if (pd->proto == IPPROTO_TCP &&
                    r->keep_state == PF_STATE_SYNPROXY && pd->dir == PF_IN) {
                        action = pf_synproxy_ack(r, pd, sm, &ctx.act);
                        if (action != PF_PASS)
                                return (action); /* PF_SYNPROXY_DROP */
                }

                if (sks != skw) {
                        struct pf_state_key     *sk;

                        if (pd->dir == PF_IN)
                                sk = sks;
                        else
                                sk = skw;
                        rewrite += pf_translate(pd,
                            &sk->addr[pd->af == pd->naf ? pd->sidx : pd->didx],
                            sk->port[pd->af == pd->naf ? pd->sidx : pd->didx],
                            &sk->addr[pd->af == pd->naf ? pd->didx : pd->sidx],
                            sk->port[pd->af == pd->naf ? pd->didx : pd->sidx],
                            virtual_type, ctx.icmp_dir);
                }

#ifdef INET6
                if (rewrite && skw->af != sks->af)
                        action = PF_AFRT;
#endif /* INET6 */

        } else {
                action = PF_PASS;

                while ((ctx.ri = SLIST_FIRST(&ctx.rules))) {
                        SLIST_REMOVE_HEAD(&ctx.rules, entry);
                        pool_put(&pf_rule_item_pl, ctx.ri);
                }
        }

        /* copy back packet headers if needed */
        if (rewrite && pd->hdrlen) {
                m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT);
        }

#if NPFSYNC > 0
        if (*sm != NULL && !ISSET((*sm)->state_flags, PFSTATE_NOSYNC) &&
            pd->dir == PF_OUT && pfsync_is_up()) {
                /*
                 * We want the state created, but we dont
                 * want to send this in case a partner
                 * firewall has to know about it to allow
                 * replies through it.
                 */
                if (pfsync_defer(*sm, pd->m))
                        return (PF_DEFER);
        }
#endif  /* NPFSYNC > 0 */

        return (action);

cleanup:
        while ((ctx.ri = SLIST_FIRST(&ctx.rules))) {
                SLIST_REMOVE_HEAD(&ctx.rules, entry);
                pool_put(&pf_rule_item_pl, ctx.ri);
        }

        return (action);
}

static __inline int
pf_create_state(struct pf_pdesc *pd, struct pf_rule *r, struct pf_rule *a,
    struct pf_rule *nr, struct pf_state_key **skw, struct pf_state_key **sks,
    int *rewrite, struct pf_state **sm, int tag, struct pf_rule_slist *rules,
    struct pf_rule_actions *act, struct pf_src_node *sns[PF_SN_MAX],
    struct pf_test_ctx *ctx)
{
        struct pf_state         *st = NULL;
        struct pf_statelim      *stlim = NULL;
        struct pf_sourcelim     *srlim = NULL;
        struct pf_source        *sr = NULL;
        struct pf_state_link    *pfl;
        struct tcphdr           *th = &pd->hdr.tcp;
        u_short                  reason;
        u_int                    i;

        st = pool_get(&pf_state_pl, PR_NOWAIT | PR_ZERO);
        if (st == NULL) {
                REASON_SET(&reason, PFRES_MEMORY);
                goto csfailed;
        }
        st->rule.ptr = r;
        st->anchor.ptr = a;
        st->natrule.ptr = nr;
        if (r->allow_opts)
                st->state_flags |= PFSTATE_ALLOWOPTS;
        if (r->rule_flag & PFRULE_STATESLOPPY)
                st->state_flags |= PFSTATE_SLOPPY;
        if (r->rule_flag & PFRULE_PFLOW)
                st->state_flags |= PFSTATE_PFLOW;
        if (r->rule_flag & PFRULE_NOSYNC)
                st->state_flags |= PFSTATE_NOSYNC;
#if NPFLOG > 0
        st->log = act->log & PF_LOG_ALL;
#endif  /* NPFLOG > 0 */
        st->qid = act->qid;
        st->pqid = act->pqid;
        st->rtableid[pd->didx] = act->rtableid;
        st->rtableid[pd->sidx] = -1;    /* return traffic is routed normally */
        st->min_ttl = act->min_ttl;
        st->set_tos = act->set_tos;
        st->max_mss = act->max_mss;
        st->state_flags |= act->flags;
#if NPFSYNC > 0
        st->sync_state = PFSYNC_S_NONE;
#endif  /* NPFSYNC > 0 */
        st->set_prio[0] = act->set_prio[0];
        st->set_prio[1] = act->set_prio[1];
        st->delay = act->delay;
        SLIST_INIT(&st->src_nodes);
        SLIST_INIT(&st->linkage);

        /*
         * must initialize refcnt, before pf_state_insert() gets called.
         * pf_state_inserts() grabs reference for pfsync!
         */
        PF_REF_INIT(st->refcnt);
        mtx_init(&st->mtx, IPL_NET);

        switch (pd->proto) {
        case IPPROTO_TCP:
                st->src.seqlo = ntohl(th->th_seq);
                st->src.seqhi = st->src.seqlo + pd->p_len + 1;
                if ((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN &&
                    r->keep_state == PF_STATE_MODULATE) {
                        /* Generate sequence number modulator */
                        st->src.seqdiff = pf_tcp_iss(pd) - st->src.seqlo;
                        if (st->src.seqdiff == 0)
                                st->src.seqdiff = 1;
                        pf_patch_32(pd, &th->th_seq,
                            htonl(st->src.seqlo + st->src.seqdiff));
                        *rewrite = 1;
                } else
                        st->src.seqdiff = 0;
                if (th->th_flags & TH_SYN) {
                        st->src.seqhi++;
                        st->src.wscale = pf_get_wscale(pd);
                }
                st->src.max_win = MAX(ntohs(th->th_win), 1);
                if (st->src.wscale & PF_WSCALE_MASK) {
                        /* Remove scale factor from initial window */
                        int win = st->src.max_win;
                        win += 1 << (st->src.wscale & PF_WSCALE_MASK);
                        st->src.max_win = (win - 1) >>
                            (st->src.wscale & PF_WSCALE_MASK);
                }
                if (th->th_flags & TH_FIN)
                        st->src.seqhi++;
                st->dst.seqhi = 1;
                st->dst.max_win = 1;
                pf_set_protostate(st, PF_PEER_SRC, TCPS_SYN_SENT);
                pf_set_protostate(st, PF_PEER_DST, TCPS_CLOSED);
                st->timeout = PFTM_TCP_FIRST_PACKET;
                atomic_inc_int(&pf_status.states_halfopen);
                break;
        case IPPROTO_UDP:
                pf_set_protostate(st, PF_PEER_SRC, PFUDPS_SINGLE);
                pf_set_protostate(st, PF_PEER_DST, PFUDPS_NO_TRAFFIC);
                st->timeout = PFTM_UDP_FIRST_PACKET;
                break;
        case IPPROTO_ICMP:
#ifdef INET6
        case IPPROTO_ICMPV6:
#endif  /* INET6 */
                st->timeout = PFTM_ICMP_FIRST_PACKET;
                break;
        default:
                pf_set_protostate(st, PF_PEER_SRC, PFOTHERS_SINGLE);
                pf_set_protostate(st, PF_PEER_DST, PFOTHERS_NO_TRAFFIC);
                st->timeout = PFTM_OTHER_FIRST_PACKET;
        }

        st->creation = st->expire = getuptime();

        if (pd->proto == IPPROTO_TCP) {
                if (st->state_flags & PFSTATE_SCRUB_TCP &&
                    pf_normalize_tcp_init(pd, &st->src)) {
                        REASON_SET(&reason, PFRES_MEMORY);
                        goto csfailed;
                }
                if (st->state_flags & PFSTATE_SCRUB_TCP && st->src.scrub &&
                    pf_normalize_tcp_stateful(pd, &reason, st,
                    &st->src, &st->dst, rewrite)) {
                        /* This really shouldn't happen!!! */
                        DPFPRINTF(LOG_ERR,
                            "%s: tcp normalize failed on first pkt", __func__);
                        goto csfailed;
                }
        }
        st->direction = pd->dir;

        if (pf_state_key_setup(pd, skw, sks, act->rtableid)) {
                REASON_SET(&reason, PFRES_MEMORY);
                goto csfailed;
        }

        if (pf_set_rt_ifp(st, pd->src, (*skw)->af, sns) != 0) {
                REASON_SET(&reason, PFRES_NOROUTE);
                goto csfailed;
        }

        for (i = 0; i < PF_SN_MAX; i++)
                if (sns[i] != NULL) {
                        struct pf_sn_item       *sni;

                        sni = pool_get(&pf_sn_item_pl, PR_NOWAIT);
                        if (sni == NULL) {
                                REASON_SET(&reason, PFRES_MEMORY);
                                goto csfailed;
                        }
                        sni->sn = sns[i];
                        SLIST_INSERT_HEAD(&st->src_nodes, sni, next);
                        sni->sn->states++;
                }

        stlim = ctx->statelim;
        if (stlim != NULL) {
                unsigned int gen;

                PF_ASSERT_LOCKED();
                pfl = pool_get(&pf_state_link_pl, PR_NOWAIT);
                if (pfl == NULL) {
                        REASON_SET(&reason, PFRES_MEMORY);
                        goto csfailed;
                }

                gen = pf_statelim_enter(stlim);
                stlim->pfstlim_counters.admitted++;
                stlim->pfstlim_inuse++;
                pf_statelim_leave(stlim, gen);

                stlim->pfstlim_rate_ts += stlim->pfstlim_rate_token;

                st->statelim = stlim->pfstlim_id;
                pfl->pfl_state = st;
                pfl->pfl_type = PF_STATE_LINK_TYPE_STATELIM;

                TAILQ_INSERT_TAIL(&stlim->pfstlim_states, pfl, pfl_link);
                SLIST_INSERT_HEAD(&st->linkage, pfl, pfl_linkage);
        }

        srlim = ctx->sourcelim;
        if (srlim != NULL) {
                unsigned int gen;

                sr = ctx->source;
                if (sr == NULL) {
                        sr = pool_get(&pf_source_pl, PR_NOWAIT|PR_ZERO);
                        if (sr == NULL) {
                                gen = pf_sourcelim_enter(srlim);
                                srlim->pfsrlim_counters.addrnomem++;
                                pf_sourcelim_leave(srlim, gen);
                                REASON_SET(&reason, PFRES_MEMORY);
                                goto csfailed;
                        }

                        sr->pfsr_parent = srlim;
                        pf_source_key(srlim, sr,
                            ctx->pd->af, ctx->pd->rdomain, ctx->pd->src);
                        TAILQ_INIT(&sr->pfsr_states);

                        if (RBT_INSERT(pf_source_tree,
                            &srlim->pfsrlim_sources, sr) != NULL) {
                                panic("%s: source pool %u (%p) "
                                    "insert collision %p?!", __func__,
                                    srlim->pfsrlim_id, srlim, sr);
                        }

                        if (RBT_INSERT(pf_source_ioc_tree,
                            &srlim->pfsrlim_ioc_sources, sr) != NULL) {
                                panic("%s: source pool %u (%p) ioc "
                                    "insert collision (%p)?!", __func__,
                                    srlim->pfsrlim_id, srlim, sr);
                        }

                        sr->pfsr_empty_ts = getuptime();
                        TAILQ_INSERT_TAIL(&pf_source_gc, sr,
                            pfsr_empty_gc);

                        gen = pf_sourcelim_enter(srlim);
                        srlim->pfsrlim_nsources++;
                        srlim->pfsrlim_counters.addrallocs++;
                        pf_sourcelim_leave(srlim, gen);
                } else {
                        KASSERT(sr->pfsr_parent == srlim);
                }

                PF_ASSERT_LOCKED();
                pfl = pool_get(&pf_state_link_pl, PR_NOWAIT);
                if (pfl == NULL) {
                        REASON_SET(&reason, PFRES_MEMORY);
                        goto csfailed;
                }

                pf_source_used(sr);

                sr->pfsr_counters.admitted++;

                gen = pf_sourcelim_enter(srlim);
                srlim->pfsrlim_counters.inuse++;
                srlim->pfsrlim_counters.admitted++;
                pf_sourcelim_leave(srlim, gen);

                st->sourcelim = srlim->pfsrlim_id;
                pfl->pfl_state = st;
                pfl->pfl_type = PF_STATE_LINK_TYPE_SOURCELIM;

                TAILQ_INSERT_TAIL(&sr->pfsr_states, pfl, pfl_link);
                SLIST_INSERT_HEAD(&st->linkage, pfl, pfl_linkage);
        }

#if NPFSYNC > 0
        pfsync_init_state(st, *skw, *sks, 0);
#endif

        if (pf_state_insert(BOUND_IFACE(r, pd->kif), skw, sks, st)) {
                *sks = *skw = NULL;
                REASON_SET(&reason, PFRES_STATEINS);
                goto csfailed;
        } else
                *sm = st;

        /*
         * Make state responsible for rules it binds here.
         */
        memcpy(&st->match_rules, rules, sizeof(st->match_rules));
        memset(rules, 0, sizeof(*rules));
        STATE_INC_COUNTERS(st);

        if (tag > 0) {
                pf_tag_ref(tag);
                st->tag = tag;
        }
        if (pd->proto == IPPROTO_TCP && (th->th_flags & (TH_SYN|TH_ACK)) ==
            TH_SYN && r->keep_state == PF_STATE_SYNPROXY && pd->dir == PF_IN) {
                int             rtid;
                uint16_t        mss, mssdflt;

                rtid = (act->rtableid >= 0) ? act->rtableid : pd->rdomain;
                pf_set_protostate(st, PF_PEER_SRC, PF_TCPS_PROXY_SRC);
                st->src.seqhi = arc4random();
                /* Find mss option */
                mssdflt = atomic_load_int(&tcp_mssdflt);
                mss = pf_get_mss(pd, mssdflt);
                mss = pf_calc_mss(pd->src, pd->af, rtid, mss, mssdflt);
                mss = pf_calc_mss(pd->dst, pd->af, rtid, mss, mssdflt);
                st->src.mss = mss;
                pf_send_tcp(r, pd->af, pd->dst, pd->src, th->th_dport,
                    th->th_sport, st->src.seqhi, ntohl(th->th_seq) + 1,
                    TH_SYN|TH_ACK, 0, st->src.mss, 0, 1, 0, pd->rdomain,
                    &reason);
                REASON_SET(&reason, PFRES_SYNPROXY);
                return (PF_SYNPROXY_DROP);
        }

        return (PF_PASS);

csfailed:
        if (st) {
                struct pf_state_link *npfl;

                SLIST_FOREACH_SAFE(pfl, &st->linkage, pfl_linkage, npfl) {
                        struct pf_state_link_list *list;
                        unsigned int gen;

                        /* who needs KASSERTS when we have NULL derefs */

                        switch (pfl->pfl_type) {
                        case PF_STATE_LINK_TYPE_STATELIM:
                                gen = pf_statelim_enter(stlim);
                                stlim->pfstlim_inuse--;
                                pf_statelim_leave(stlim, gen);

                                stlim->pfstlim_rate_ts -=
                                    stlim->pfstlim_rate_token;
                                list = &stlim->pfstlim_states;
                                break;
                        case PF_STATE_LINK_TYPE_SOURCELIM:
                                gen = pf_sourcelim_enter(srlim);
                                srlim->pfsrlim_counters.inuse--;
                                pf_sourcelim_leave(srlim, gen);

                                sr->pfsr_rate_ts -=
                                    srlim->pfsrlim_rate_token;
                                pf_source_rele(sr);

                                list = &sr->pfsr_states;
                                break;
                        default:
                                panic("%s: unexpected link type on pfl %p",
                                    __func__, pfl);
                        }

                        TAILQ_REMOVE(list, pfl, pfl_link);
                        PF_ASSERT_LOCKED();
                        pool_put(&pf_state_link_pl, pfl);
                }

                pf_normalize_tcp_cleanup(st);   /* safe even w/o init */
                pf_src_tree_remove_state(st);
                pool_put(&pf_state_pl, st);
        }

        for (i = 0; i < PF_SN_MAX; i++)
                if (sns[i] != NULL)
                        pf_remove_src_node(sns[i]);

        return (PF_DROP);
}

int
pf_translate(struct pf_pdesc *pd, struct pf_addr *saddr, u_int16_t sport,
    struct pf_addr *daddr, u_int16_t dport, u_int16_t virtual_type,
    int icmp_dir)
{
        int     rewrite = 0;
        int     afto = pd->af != pd->naf;

        if (afto || PF_ANEQ(daddr, pd->dst, pd->af))
                pd->destchg = 1;

        switch (pd->proto) {
        case IPPROTO_TCP:       /* FALLTHROUGH */
        case IPPROTO_UDP:
                rewrite += pf_patch_16(pd, pd->sport, sport);
                rewrite += pf_patch_16(pd, pd->dport, dport);
                break;

        case IPPROTO_ICMP:
                if (pd->af != AF_INET)
                        return (0);

#ifdef INET6
                if (afto) {
                        if (pf_translate_icmp_af(pd, AF_INET6, &pd->hdr.icmp))
                                return (0);
                        pd->proto = IPPROTO_ICMPV6;
                        rewrite = 1;
                }
#endif /* INET6 */
                if (virtual_type == htons(ICMP_ECHO)) {
                        u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport;
                        rewrite += pf_patch_16(pd,
                            &pd->hdr.icmp.icmp_id, icmpid);
                }
                break;

#ifdef INET6
        case IPPROTO_ICMPV6:
                if (pd->af != AF_INET6)
                        return (0);

                if (afto) {
                        if (pf_translate_icmp_af(pd, AF_INET, &pd->hdr.icmp6))
                                return (0);
                        pd->proto = IPPROTO_ICMP;
                        rewrite = 1;
                }
                if (virtual_type == htons(ICMP6_ECHO_REQUEST)) {
                        u_int16_t icmpid = (icmp_dir == PF_IN) ? sport : dport;
                        rewrite += pf_patch_16(pd,
                            &pd->hdr.icmp6.icmp6_id, icmpid);
                }
                break;
#endif /* INET6 */
        }

        if (!afto) {
                rewrite += pf_translate_a(pd, pd->src, saddr);
                rewrite += pf_translate_a(pd, pd->dst, daddr);
        }

        return (rewrite);
}

int
pf_tcp_track_full(struct pf_pdesc *pd, struct pf_state **stp, u_short *reason,
    int *copyback, int reverse)
{
        struct tcphdr           *th = &pd->hdr.tcp;
        struct pf_state_peer    *src, *dst;
        u_int16_t                win = ntohs(th->th_win);
        u_int32_t                ack, end, data_end, seq, orig_seq;
        u_int8_t                 sws, dws, psrc, pdst;
        int                      ackskew;

        if ((pd->dir == (*stp)->direction && !reverse) ||
            (pd->dir != (*stp)->direction && reverse)) {
                src = &(*stp)->src;
                dst = &(*stp)->dst;
                psrc = PF_PEER_SRC;
                pdst = PF_PEER_DST;
        } else {
                src = &(*stp)->dst;
                dst = &(*stp)->src;
                psrc = PF_PEER_DST;
                pdst = PF_PEER_SRC;
        }

        if (src->wscale && dst->wscale && !(th->th_flags & TH_SYN)) {
                sws = src->wscale & PF_WSCALE_MASK;
                dws = dst->wscale & PF_WSCALE_MASK;
        } else
                sws = dws = 0;

        /*
         * Sequence tracking algorithm from Guido van Rooij's paper:
         *   http://www.madison-gurkha.com/publications/tcp_filtering/
         *      tcp_filtering.ps
         */

        orig_seq = seq = ntohl(th->th_seq);
        if (src->seqlo == 0) {
                /* First packet from this end. Set its state */

                if (((*stp)->state_flags & PFSTATE_SCRUB_TCP || dst->scrub) &&
                    src->scrub == NULL) {
                        if (pf_normalize_tcp_init(pd, src)) {
                                REASON_SET(reason, PFRES_MEMORY);
                                return (PF_DROP);
                        }
                }

                /* Deferred generation of sequence number modulator */
                if (dst->seqdiff && !src->seqdiff) {
                        /* use random iss for the TCP server */
                        while ((src->seqdiff = arc4random() - seq) == 0)
                                continue;
                        ack = ntohl(th->th_ack) - dst->seqdiff;
                        pf_patch_32(pd, &th->th_seq, htonl(seq + src->seqdiff));
                        pf_patch_32(pd, &th->th_ack, htonl(ack));
                        *copyback = 1;
                } else {
                        ack = ntohl(th->th_ack);
                }

                end = seq + pd->p_len;
                if (th->th_flags & TH_SYN) {
                        end++;
                        if (dst->wscale & PF_WSCALE_FLAG) {
                                src->wscale = pf_get_wscale(pd);
                                if (src->wscale & PF_WSCALE_FLAG) {
                                        /* Remove scale factor from initial
                                         * window */
                                        sws = src->wscale & PF_WSCALE_MASK;
                                        win = ((u_int32_t)win + (1 << sws) - 1)
                                            >> sws;
                                        dws = dst->wscale & PF_WSCALE_MASK;
                                } else {
                                        /* fixup other window */
                                        dst->max_win = MIN(TCP_MAXWIN,
                                            (u_int32_t)dst->max_win <<
                                            (dst->wscale & PF_WSCALE_MASK));
                                        /* in case of a retrans SYN|ACK */
                                        dst->wscale = 0;
                                }
                        }
                }
                data_end = end;
                if (th->th_flags & TH_FIN)
                        end++;

                src->seqlo = seq;
                if (src->state < TCPS_SYN_SENT)
                        pf_set_protostate(*stp, psrc, TCPS_SYN_SENT);

                /*
                 * May need to slide the window (seqhi may have been set by
                 * the crappy stack check or if we picked up the connection
                 * after establishment)
                 */
                if (src->seqhi == 1 ||
                    SEQ_GEQ(end + MAX(1, dst->max_win << dws), src->seqhi))
                        src->seqhi = end + MAX(1, dst->max_win << dws);
                if (win > src->max_win)
                        src->max_win = win;

        } else {
                ack = ntohl(th->th_ack) - dst->seqdiff;
                if (src->seqdiff) {
                        /* Modulate sequence numbers */
                        pf_patch_32(pd, &th->th_seq, htonl(seq + src->seqdiff));
                        pf_patch_32(pd, &th->th_ack, htonl(ack));
                        *copyback = 1;
                }
                end = seq + pd->p_len;
                if (th->th_flags & TH_SYN)
                        end++;
                data_end = end;
                if (th->th_flags & TH_FIN)
                        end++;
        }

        if ((th->th_flags & TH_ACK) == 0) {
                /* Let it pass through the ack skew check */
                ack = dst->seqlo;
        } else if ((ack == 0 &&
            (th->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) ||
            /* broken tcp stacks do not set ack */
            (dst->state < TCPS_SYN_SENT)) {
                /*
                 * Many stacks (ours included) will set the ACK number in an
                 * FIN|ACK if the SYN times out -- no sequence to ACK.
                 */
                ack = dst->seqlo;
        }

        if (seq == end) {
                /* Ease sequencing restrictions on no data packets */
                seq = src->seqlo;
                data_end = end = seq;
        }

        ackskew = dst->seqlo - ack;


        /*
         * Need to demodulate the sequence numbers in any TCP SACK options
         * (Selective ACK). We could optionally validate the SACK values
         * against the current ACK window, either forwards or backwards, but
         * I'm not confident that SACK has been implemented properly
         * everywhere. It wouldn't surprise me if several stacks accidentally
         * SACK too far backwards of previously ACKed data. There really aren't
         * any security implications of bad SACKing unless the target stack
         * doesn't validate the option length correctly. Someone trying to
         * spoof into a TCP connection won't bother blindly sending SACK
         * options anyway.
         */
        if (dst->seqdiff && (th->th_off << 2) > sizeof(struct tcphdr)) {
                if (pf_modulate_sack(pd, dst))
                        *copyback = 1;
        }


#define MAXACKWINDOW (0xffff + 1500)    /* 1500 is an arbitrary fudge factor */
        if (SEQ_GEQ(src->seqhi, data_end) &&
            /* Last octet inside other's window space */
            SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) &&
            /* Retrans: not more than one window back */
            (ackskew >= -MAXACKWINDOW) &&
            /* Acking not more than one reassembled fragment backwards */
            (ackskew <= (MAXACKWINDOW << sws)) &&
            /* Acking not more than one window forward */
            ((th->th_flags & TH_RST) == 0 || orig_seq == src->seqlo ||
            (orig_seq == src->seqlo + 1) || (orig_seq + 1 == src->seqlo) ||
            /* Require an exact/+1 sequence match on resets when possible */
            (SEQ_GEQ(orig_seq, src->seqlo - (dst->max_win << dws)) &&
            SEQ_LEQ(orig_seq, src->seqlo + 1) && ackskew == 0 &&
            (th->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)))) {
            /* Allow resets to match sequence window if ack is perfect match */

                if (dst->scrub || src->scrub) {
                        if (pf_normalize_tcp_stateful(pd, reason, *stp, src,
                            dst, copyback))
                                return (PF_DROP);
                }

                /* update max window */
                if (src->max_win < win)
                        src->max_win = win;
                /* synchronize sequencing */
                if (SEQ_GT(end, src->seqlo))
                        src->seqlo = end;
                /* slide the window of what the other end can send */
                if (SEQ_GEQ(ack + (win << sws), dst->seqhi))
                        dst->seqhi = ack + MAX((win << sws), 1);

                /* update states */
                if (th->th_flags & TH_SYN)
                        if (src->state < TCPS_SYN_SENT)
                                pf_set_protostate(*stp, psrc, TCPS_SYN_SENT);
                if (th->th_flags & TH_FIN)
                        if (src->state < TCPS_CLOSING)
                                pf_set_protostate(*stp, psrc, TCPS_CLOSING);
                if (th->th_flags & TH_ACK) {
                        if (dst->state == TCPS_SYN_SENT) {
                                pf_set_protostate(*stp, pdst,
                                    TCPS_ESTABLISHED);
                                if (src->state == TCPS_ESTABLISHED &&
                                    !SLIST_EMPTY(&(*stp)->src_nodes) &&
                                    pf_src_connlimit(stp)) {
                                        REASON_SET(reason, PFRES_SRCLIMIT);
                                        return (PF_DROP);
                                }
                        } else if (dst->state == TCPS_CLOSING)
                                pf_set_protostate(*stp, pdst,
                                    TCPS_FIN_WAIT_2);
                }
                if (th->th_flags & TH_RST)
                        pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_TIME_WAIT);

                /* update expire time */
                (*stp)->expire = getuptime();
                if (src->state >= TCPS_FIN_WAIT_2 &&
                    dst->state >= TCPS_FIN_WAIT_2)
                        pf_update_state_timeout(*stp, PFTM_TCP_CLOSED);
                else if (src->state >= TCPS_CLOSING &&
                    dst->state >= TCPS_CLOSING)
                        pf_update_state_timeout(*stp, PFTM_TCP_FIN_WAIT);
                else if (src->state < TCPS_ESTABLISHED ||
                    dst->state < TCPS_ESTABLISHED)
                        pf_update_state_timeout(*stp, PFTM_TCP_OPENING);
                else if (src->state >= TCPS_CLOSING ||
                    dst->state >= TCPS_CLOSING)
                        pf_update_state_timeout(*stp, PFTM_TCP_CLOSING);
                else
                        pf_update_state_timeout(*stp, PFTM_TCP_ESTABLISHED);

                /* Fall through to PASS packet */
        } else if ((dst->state < TCPS_SYN_SENT ||
                dst->state >= TCPS_FIN_WAIT_2 ||
                src->state >= TCPS_FIN_WAIT_2) &&
            SEQ_GEQ(src->seqhi + MAXACKWINDOW, data_end) &&
            /* Within a window forward of the originating packet */
            SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW)) {
            /* Within a window backward of the originating packet */

                /*
                 * This currently handles three situations:
                 *  1) Stupid stacks will shotgun SYNs before their peer
                 *     replies.
                 *  2) When PF catches an already established stream (the
                 *     firewall rebooted, the state table was flushed, routes
                 *     changed...)
                 *  3) Packets get funky immediately after the connection
                 *     closes (this should catch Solaris spurious ACK|FINs
                 *     that web servers like to spew after a close)
                 *
                 * This must be a little more careful than the above code
                 * since packet floods will also be caught here. We don't
                 * update the TTL here to mitigate the damage of a packet
                 * flood and so the same code can handle awkward establishment
                 * and a loosened connection close.
                 * In the establishment case, a correct peer response will
                 * validate the connection, go through the normal state code
                 * and keep updating the state TTL.
                 */

                if (pf_status.debug >= LOG_NOTICE) {
                        log(LOG_NOTICE, "pf: loose state match: ");
                        pf_print_state(*stp);
                        pf_print_flags(th->th_flags);
                        addlog(" seq=%u (%u) ack=%u len=%u ackskew=%d "
                            "pkts=%llu:%llu dir=%s,%s\n", seq, orig_seq, ack,
                            pd->p_len, ackskew, (*stp)->packets[0],
                            (*stp)->packets[1],
                            pd->dir == PF_IN ? "in" : "out",
                            pd->dir == (*stp)->direction ? "fwd" : "rev");
                }

                if (dst->scrub || src->scrub) {
                        if (pf_normalize_tcp_stateful(pd, reason, *stp, src,
                            dst, copyback))
                                return (PF_DROP);
                }

                /* update max window */
                if (src->max_win < win)
                        src->max_win = win;
                /* synchronize sequencing */
                if (SEQ_GT(end, src->seqlo))
                        src->seqlo = end;
                /* slide the window of what the other end can send */
                if (SEQ_GEQ(ack + (win << sws), dst->seqhi))
                        dst->seqhi = ack + MAX((win << sws), 1);

                /*
                 * Cannot set dst->seqhi here since this could be a shotgunned
                 * SYN and not an already established connection.
                 */
                if (th->th_flags & TH_FIN)
                        if (src->state < TCPS_CLOSING)
                                pf_set_protostate(*stp, psrc, TCPS_CLOSING);
                if (th->th_flags & TH_RST)
                        pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_TIME_WAIT);

                /* Fall through to PASS packet */
        } else {
                if ((*stp)->dst.state == TCPS_SYN_SENT &&
                    (*stp)->src.state == TCPS_SYN_SENT) {
                        /* Send RST for state mismatches during handshake */
                        if (!(th->th_flags & TH_RST))
                                pf_send_tcp((*stp)->rule.ptr, pd->af,
                                    pd->dst, pd->src, th->th_dport,
                                    th->th_sport, ntohl(th->th_ack), 0,
                                    TH_RST, 0, 0,
                                    (*stp)->rule.ptr->return_ttl, 1, 0,
                                    pd->rdomain, reason);
                        src->seqlo = 0;
                        src->seqhi = 1;
                        src->max_win = 1;
                } else if (pf_status.debug >= LOG_NOTICE) {
                        log(LOG_NOTICE, "pf: BAD state: ");
                        pf_print_state(*stp);
                        pf_print_flags(th->th_flags);
                        addlog(" seq=%u (%u) ack=%u len=%u ackskew=%d "
                            "pkts=%llu:%llu dir=%s,%s\n",
                            seq, orig_seq, ack, pd->p_len, ackskew,
                            (*stp)->packets[0], (*stp)->packets[1],
                            pd->dir == PF_IN ? "in" : "out",
                            pd->dir == (*stp)->direction ? "fwd" : "rev");
                        addlog("pf: State failure on: %c %c %c %c | %c %c\n",
                            SEQ_GEQ(src->seqhi, data_end) ? ' ' : '1',
                            SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) ?
                            ' ': '2',
                            (ackskew >= -MAXACKWINDOW) ? ' ' : '3',
                            (ackskew <= (MAXACKWINDOW << sws)) ? ' ' : '4',
                            SEQ_GEQ(src->seqhi + MAXACKWINDOW, data_end) ?
                            ' ' :'5',
                            SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW) ?' ' :'6');
                }
                REASON_SET(reason, PFRES_BADSTATE);
                return (PF_DROP);
        }

        return (PF_PASS);
}

int
pf_tcp_track_sloppy(struct pf_pdesc *pd, struct pf_state **stp,
    u_short *reason)
{
        struct tcphdr           *th = &pd->hdr.tcp;
        struct pf_state_peer    *src, *dst;
        u_int8_t                 psrc, pdst;

        if (pd->dir == (*stp)->direction) {
                src = &(*stp)->src;
                dst = &(*stp)->dst;
                psrc = PF_PEER_SRC;
                pdst = PF_PEER_DST;
        } else {
                src = &(*stp)->dst;
                dst = &(*stp)->src;
                psrc = PF_PEER_DST;
                pdst = PF_PEER_SRC;
        }

        if (th->th_flags & TH_SYN)
                if (src->state < TCPS_SYN_SENT)
                        pf_set_protostate(*stp, psrc, TCPS_SYN_SENT);
        if (th->th_flags & TH_FIN)
                if (src->state < TCPS_CLOSING)
                        pf_set_protostate(*stp, psrc, TCPS_CLOSING);
        if (th->th_flags & TH_ACK) {
                if (dst->state == TCPS_SYN_SENT) {
                        pf_set_protostate(*stp, pdst, TCPS_ESTABLISHED);
                        if (src->state == TCPS_ESTABLISHED &&
                            !SLIST_EMPTY(&(*stp)->src_nodes) &&
                            pf_src_connlimit(stp)) {
                                REASON_SET(reason, PFRES_SRCLIMIT);
                                return (PF_DROP);
                        }
                } else if (dst->state == TCPS_CLOSING) {
                        pf_set_protostate(*stp, pdst, TCPS_FIN_WAIT_2);
                } else if (src->state == TCPS_SYN_SENT &&
                    dst->state < TCPS_SYN_SENT) {
                        /*
                         * Handle a special sloppy case where we only see one
                         * half of the connection. If there is a ACK after
                         * the initial SYN without ever seeing a packet from
                         * the destination, set the connection to established.
                         */
                        pf_set_protostate(*stp, PF_PEER_BOTH,
                            TCPS_ESTABLISHED);
                        if (!SLIST_EMPTY(&(*stp)->src_nodes) &&
                            pf_src_connlimit(stp)) {
                                REASON_SET(reason, PFRES_SRCLIMIT);
                                return (PF_DROP);
                        }
                } else if (src->state == TCPS_CLOSING &&
                    dst->state == TCPS_ESTABLISHED &&
                    dst->seqlo == 0) {
                        /*
                         * Handle the closing of half connections where we
                         * don't see the full bidirectional FIN/ACK+ACK
                         * handshake.
                         */
                        pf_set_protostate(*stp, pdst, TCPS_CLOSING);
                }
        }
        if (th->th_flags & TH_RST)
                pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_TIME_WAIT);

        /* update expire time */
        (*stp)->expire = getuptime();
        if (src->state >= TCPS_FIN_WAIT_2 &&
            dst->state >= TCPS_FIN_WAIT_2)
                pf_update_state_timeout(*stp, PFTM_TCP_CLOSED);
        else if (src->state >= TCPS_CLOSING &&
            dst->state >= TCPS_CLOSING)
                pf_update_state_timeout(*stp, PFTM_TCP_FIN_WAIT);
        else if (src->state < TCPS_ESTABLISHED ||
            dst->state < TCPS_ESTABLISHED)
                pf_update_state_timeout(*stp, PFTM_TCP_OPENING);
        else if (src->state >= TCPS_CLOSING ||
            dst->state >= TCPS_CLOSING)
                pf_update_state_timeout(*stp, PFTM_TCP_CLOSING);
        else
                pf_update_state_timeout(*stp, PFTM_TCP_ESTABLISHED);

        return (PF_PASS);
}

static __inline int
pf_synproxy(struct pf_pdesc *pd, struct pf_state **stp, u_short *reason)
{
        struct pf_state_key     *sk = (*stp)->key[pd->didx];

        if ((*stp)->src.state == PF_TCPS_PROXY_SRC) {
                struct tcphdr   *th = &pd->hdr.tcp;

                if (pd->dir != (*stp)->direction) {
                        REASON_SET(reason, PFRES_SYNPROXY);
                        return (PF_SYNPROXY_DROP);
                }
                if (th->th_flags & TH_SYN) {
                        if (ntohl(th->th_seq) != (*stp)->src.seqlo) {
                                REASON_SET(reason, PFRES_SYNPROXY);
                                return (PF_DROP);
                        }
                        pf_send_tcp((*stp)->rule.ptr, pd->af, pd->dst,
                            pd->src, th->th_dport, th->th_sport,
                            (*stp)->src.seqhi, ntohl(th->th_seq) + 1,
                            TH_SYN|TH_ACK, 0, (*stp)->src.mss, 0, 1,
                            0, pd->rdomain, reason);
                        REASON_SET(reason, PFRES_SYNPROXY);
                        return (PF_SYNPROXY_DROP);
                } else if ((th->th_flags & (TH_ACK|TH_RST|TH_FIN)) != TH_ACK ||
                    (ntohl(th->th_ack) != (*stp)->src.seqhi + 1) ||
                    (ntohl(th->th_seq) != (*stp)->src.seqlo + 1)) {
                        REASON_SET(reason, PFRES_SYNPROXY);
                        return (PF_DROP);
                } else if (!SLIST_EMPTY(&(*stp)->src_nodes) &&
                    pf_src_connlimit(stp)) {
                        REASON_SET(reason, PFRES_SRCLIMIT);
                        return (PF_DROP);
                } else
                        pf_set_protostate(*stp, PF_PEER_SRC,
                            PF_TCPS_PROXY_DST);
        }
        if ((*stp)->src.state == PF_TCPS_PROXY_DST) {
                struct tcphdr   *th = &pd->hdr.tcp;

                if (pd->dir == (*stp)->direction) {
                        if (((th->th_flags & (TH_SYN|TH_ACK)) != TH_ACK) ||
                            (ntohl(th->th_ack) != (*stp)->src.seqhi + 1) ||
                            (ntohl(th->th_seq) != (*stp)->src.seqlo + 1)) {
                                REASON_SET(reason, PFRES_SYNPROXY);
                                return (PF_DROP);
                        }
                        (*stp)->src.max_win = MAX(ntohs(th->th_win), 1);
                        if ((*stp)->dst.seqhi == 1)
                                (*stp)->dst.seqhi = arc4random();
                        pf_send_tcp((*stp)->rule.ptr, pd->af,
                            &sk->addr[pd->sidx], &sk->addr[pd->didx],
                            sk->port[pd->sidx], sk->port[pd->didx],
                            (*stp)->dst.seqhi, 0, TH_SYN, 0,
                            (*stp)->src.mss, 0, 0, (*stp)->tag,
                            sk->rdomain, reason);
                        REASON_SET(reason, PFRES_SYNPROXY);
                        return (PF_SYNPROXY_DROP);
                } else if (((th->th_flags & (TH_SYN|TH_ACK)) !=
                    (TH_SYN|TH_ACK)) ||
                    (ntohl(th->th_ack) != (*stp)->dst.seqhi + 1)) {
                        REASON_SET(reason, PFRES_SYNPROXY);
                        return (PF_DROP);
                } else {
                        (*stp)->dst.max_win = MAX(ntohs(th->th_win), 1);
                        (*stp)->dst.seqlo = ntohl(th->th_seq);
                        pf_send_tcp((*stp)->rule.ptr, pd->af, pd->dst,
                            pd->src, th->th_dport, th->th_sport,
                            ntohl(th->th_ack), ntohl(th->th_seq) + 1,
                            TH_ACK, (*stp)->src.max_win, 0, 0, 0,
                            (*stp)->tag, pd->rdomain, reason);
                        pf_send_tcp((*stp)->rule.ptr, pd->af,
                            &sk->addr[pd->sidx], &sk->addr[pd->didx],
                            sk->port[pd->sidx], sk->port[pd->didx],
                            (*stp)->src.seqhi + 1, (*stp)->src.seqlo + 1,
                            TH_ACK, (*stp)->dst.max_win, 0, 0, 1,
                            0, sk->rdomain, reason);
                        (*stp)->src.seqdiff = (*stp)->dst.seqhi -
                            (*stp)->src.seqlo;
                        (*stp)->dst.seqdiff = (*stp)->src.seqhi -
                            (*stp)->dst.seqlo;
                        (*stp)->src.seqhi = (*stp)->src.seqlo +
                            (*stp)->dst.max_win;
                        (*stp)->dst.seqhi = (*stp)->dst.seqlo +
                            (*stp)->src.max_win;
                        (*stp)->src.wscale = (*stp)->dst.wscale = 0;
                        pf_set_protostate(*stp, PF_PEER_BOTH,
                            TCPS_ESTABLISHED);
                        REASON_SET(reason, PFRES_SYNPROXY);
                        return (PF_SYNPROXY_DROP);
                }
        }
        return (PF_PASS);
}

static __inline int
pf_synproxy_ack(struct pf_rule *r, struct pf_pdesc *pd, struct pf_state **sm,
    struct pf_rule_actions *act)
{
        struct tcphdr           *th = &pd->hdr.tcp;
        struct pf_state         *s;
        u_int16_t                mss, mssdflt;
        int                      rtid;
        u_short                  reason;

        if ((th->th_flags & (TH_SYN|TH_ACK)) != TH_SYN)
                return (PF_PASS);

        s = *sm;
        rtid = (act->rtableid >= 0) ? act->rtableid : pd->rdomain;

        pf_set_protostate(s, PF_PEER_SRC, PF_TCPS_PROXY_SRC);
        s->src.seqhi = arc4random();
        /* Find mss option */
        mssdflt = atomic_load_int(&tcp_mssdflt);
        mss = pf_get_mss(pd, mssdflt);
        mss = pf_calc_mss(pd->src, pd->af, rtid, mss, mssdflt);
        mss = pf_calc_mss(pd->dst, pd->af, rtid, mss, mssdflt);
        s->src.mss = mss;

        pf_send_tcp(r, pd->af, pd->dst, pd->src, th->th_dport,
            th->th_sport, s->src.seqhi, ntohl(th->th_seq) + 1,
            TH_SYN|TH_ACK, 0, s->src.mss, 0, 1, 0, pd->rdomain, NULL);

        REASON_SET(&reason, PFRES_SYNPROXY);
        return (PF_SYNPROXY_DROP);
}

int
pf_test_state(struct pf_pdesc *pd, struct pf_state **stp, u_short *reason)
{
        int                      copyback = 0;
        struct pf_state_peer    *src, *dst;
        int                      action;
        u_int8_t                 psrc, pdst;

        action = PF_PASS;
        if (pd->dir == (*stp)->direction) {
                src = &(*stp)->src;
                dst = &(*stp)->dst;
                psrc = PF_PEER_SRC;
                pdst = PF_PEER_DST;
        } else {
                src = &(*stp)->dst;
                dst = &(*stp)->src;
                psrc = PF_PEER_DST;
                pdst = PF_PEER_SRC;
        }

        switch (pd->virtual_proto) {
        case IPPROTO_TCP:
                if ((action = pf_synproxy(pd, stp, reason)) != PF_PASS)
                        return (action);
                if ((pd->hdr.tcp.th_flags & (TH_SYN|TH_ACK)) == TH_SYN) {

                        if (dst->state >= TCPS_FIN_WAIT_2 &&
                            src->state >= TCPS_FIN_WAIT_2) {
                                if (pf_status.debug >= LOG_NOTICE) {
                                        log(LOG_NOTICE, "pf: state reuse ");
                                        pf_print_state(*stp);
                                        pf_print_flags(pd->hdr.tcp.th_flags);
                                        addlog("\n");
                                }
                                /* XXX make sure it's the same direction ?? */
                                pf_update_state_timeout(*stp, PFTM_PURGE);
                                pf_state_unref(*stp);
                                *stp = NULL;
                                return (PF_DROP);
                        } else if (dst->state >= TCPS_ESTABLISHED &&
                            src->state >= TCPS_ESTABLISHED) {
                                /*
                                 * SYN matches existing state???
                                 * Typically happens when sender boots up after
                                 * sudden panic. Certain protocols (NFSv3) are
                                 * always using same port numbers. Challenge
                                 * ACK enables all parties (firewall and peers)
                                 * to get in sync again.
                                 */
                                pf_send_challenge_ack(pd, *stp, src, dst,
                                    reason);
                                return (PF_DROP);
                        }
                }

                if ((*stp)->state_flags & PFSTATE_SLOPPY) {
                        if (pf_tcp_track_sloppy(pd, stp, reason) == PF_DROP)
                                return (PF_DROP);
                } else {
                        if (pf_tcp_track_full(pd, stp, reason, &copyback,
                            PF_REVERSED_KEY((*stp)->key, pd->af)) == PF_DROP)
                                return (PF_DROP);
                }
                break;
        case IPPROTO_UDP:
                /* update states */
                if (src->state < PFUDPS_SINGLE)
                        pf_set_protostate(*stp, psrc, PFUDPS_SINGLE);
                if (dst->state == PFUDPS_SINGLE)
                        pf_set_protostate(*stp, pdst, PFUDPS_MULTIPLE);

                /* update expire time */
                (*stp)->expire = getuptime();
                if (src->state == PFUDPS_MULTIPLE &&
                    dst->state == PFUDPS_MULTIPLE)
                        pf_update_state_timeout(*stp, PFTM_UDP_MULTIPLE);
                else
                        pf_update_state_timeout(*stp, PFTM_UDP_SINGLE);
                break;
        default:
                /* update states */
                if (src->state < PFOTHERS_SINGLE)
                        pf_set_protostate(*stp, psrc, PFOTHERS_SINGLE);
                if (dst->state == PFOTHERS_SINGLE)
                        pf_set_protostate(*stp, pdst, PFOTHERS_MULTIPLE);

                /* update expire time */
                (*stp)->expire = getuptime();
                if (src->state == PFOTHERS_MULTIPLE &&
                    dst->state == PFOTHERS_MULTIPLE)
                        pf_update_state_timeout(*stp, PFTM_OTHER_MULTIPLE);
                else
                        pf_update_state_timeout(*stp, PFTM_OTHER_SINGLE);
                break;
        }

        /* translate source/destination address, if necessary */
        if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) {
                struct pf_state_key     *nk;
                int                      afto, sidx, didx;

                if (PF_REVERSED_KEY((*stp)->key, pd->af))
                        nk = (*stp)->key[pd->sidx];
                else
                        nk = (*stp)->key[pd->didx];

                afto = pd->af != nk->af;
                sidx = afto ? pd->didx : pd->sidx;
                didx = afto ? pd->sidx : pd->didx;

#ifdef INET6
                if (afto) {
                        pf_addrcpy(&pd->nsaddr, &nk->addr[sidx], nk->af);
                        pf_addrcpy(&pd->ndaddr, &nk->addr[didx], nk->af);
                        pd->naf = nk->af;
                        action = PF_AFRT;
                }
#endif /* INET6 */

                if (!afto)
                        pf_translate_a(pd, pd->src, &nk->addr[sidx]);

                if (pd->sport != NULL)
                        pf_patch_16(pd, pd->sport, nk->port[sidx]);

                if (afto || PF_ANEQ(pd->dst, &nk->addr[didx], pd->af) ||
                    pd->rdomain != nk->rdomain)
                        pd->destchg = 1;

                if (!afto)
                        pf_translate_a(pd, pd->dst, &nk->addr[didx]);

                if (pd->dport != NULL)
                        pf_patch_16(pd, pd->dport, nk->port[didx]);

                pd->m->m_pkthdr.ph_rtableid = nk->rdomain;
                copyback = 1;
        }

        if (copyback && pd->hdrlen > 0) {
                m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT);
        }

        return (action);
}

int
pf_icmp_state_lookup(struct pf_pdesc *pd, struct pf_state_key_cmp *key,
    struct pf_state **stp, u_int16_t icmpid, u_int16_t type,
    int icmp_dir, int *iidx, int multi, int inner)
{
        int direction, action;

        key->af = pd->af;
        key->proto = pd->proto;
        key->rdomain = pd->rdomain;
        if (icmp_dir == PF_IN) {
                *iidx = pd->sidx;
                key->port[pd->sidx] = icmpid;
                key->port[pd->didx] = type;
        } else {
                *iidx = pd->didx;
                key->port[pd->sidx] = type;
                key->port[pd->didx] = icmpid;
        }

        if (pf_state_key_addr_setup(pd, key, pd->sidx, pd->src, pd->didx,
            pd->dst, pd->af, multi))
                return (PF_DROP);

        key->hash = pf_pkt_hash(key->af, key->proto,
            &key->addr[0], &key->addr[1], 0, 0);

        action = pf_find_state(pd, key, stp);
        if (action != PF_MATCH)
                return (action);

        if ((*stp)->state_flags & PFSTATE_SLOPPY)
                return (-1);

        /* Is this ICMP message flowing in right direction? */
        if ((*stp)->key[PF_SK_WIRE]->af != (*stp)->key[PF_SK_STACK]->af)
                direction = (pd->af == (*stp)->key[PF_SK_WIRE]->af) ?
                    PF_IN : PF_OUT;
        else
                direction = (*stp)->direction;
        if ((((!inner && direction == pd->dir) ||
            (inner && direction != pd->dir)) ?
            PF_IN : PF_OUT) != icmp_dir) {
                if (pf_status.debug >= LOG_NOTICE) {
                        log(LOG_NOTICE,
                            "pf: icmp type %d in wrong direction (%d): ",
                            ntohs(type), icmp_dir);
                        pf_print_state(*stp);
                        addlog("\n");
                }
                return (PF_DROP);
        }
        return (-1);
}

int
pf_test_state_icmp(struct pf_pdesc *pd, struct pf_state **stp,
    u_short *reason)
{
        u_int16_t        virtual_id, virtual_type;
        u_int8_t         icmptype, icmpcode;
        int              icmp_dir, iidx, ret, copyback = 0;

        struct pf_state_key_cmp key;

        switch (pd->proto) {
        case IPPROTO_ICMP:
                icmptype = pd->hdr.icmp.icmp_type;
                icmpcode = pd->hdr.icmp.icmp_code;
                break;
#ifdef INET6
        case IPPROTO_ICMPV6:
                icmptype = pd->hdr.icmp6.icmp6_type;
                icmpcode = pd->hdr.icmp6.icmp6_code;
                break;
#endif /* INET6 */
        default:
                panic("unhandled proto %d", pd->proto);
        }

        if (pf_icmp_mapping(pd, icmptype, &icmp_dir, &virtual_id,
            &virtual_type) == 0) {
                /*
                 * ICMP query/reply message not related to a TCP/UDP packet.
                 * Search for an ICMP state.
                 */
                ret = pf_icmp_state_lookup(pd, &key, stp,
                    virtual_id, virtual_type, icmp_dir, &iidx,
                    0, 0);
                /* IPv6? try matching a multicast address */
                if (ret == PF_DROP && pd->af == AF_INET6 && icmp_dir == PF_OUT)
                        ret = pf_icmp_state_lookup(pd, &key, stp, virtual_id,
                            virtual_type, icmp_dir, &iidx, 1, 0);
                if (ret >= 0)
                        return (ret);

                (*stp)->expire = getuptime();
                pf_update_state_timeout(*stp, PFTM_ICMP_ERROR_REPLY);

                /* translate source/destination address, if necessary */
                if ((*stp)->key[PF_SK_WIRE] != (*stp)->key[PF_SK_STACK]) {
                        struct pf_state_key     *nk;
                        int                      afto, sidx, didx;

                        if (PF_REVERSED_KEY((*stp)->key, pd->af))
                                nk = (*stp)->key[pd->sidx];
                        else
                                nk = (*stp)->key[pd->didx];

                        afto = pd->af != nk->af;
                        sidx = afto ? pd->didx : pd->sidx;
                        didx = afto ? pd->sidx : pd->didx;
                        iidx = afto ? !iidx : iidx;
#ifdef  INET6
                        if (afto) {
                                pf_addrcpy(&pd->nsaddr, &nk->addr[sidx],
                                    nk->af);
                                pf_addrcpy(&pd->ndaddr, &nk->addr[didx],
                                    nk->af);
                                pd->naf = nk->af;
                        }
#endif /* INET6 */
                        if (!afto) {
                                pf_translate_a(pd, pd->src, &nk->addr[sidx]);
                                pf_translate_a(pd, pd->dst, &nk->addr[didx]);
                        }

                        if (pd->rdomain != nk->rdomain)
                                pd->destchg = 1;
                        if (!afto && PF_ANEQ(pd->dst,
                                &nk->addr[didx], pd->af))
                                pd->destchg = 1;
                        pd->m->m_pkthdr.ph_rtableid = nk->rdomain;

                        switch (pd->af) {
                        case AF_INET:
#ifdef INET6
                                if (afto) {
                                        if (pf_translate_icmp_af(pd, AF_INET6,
                                            &pd->hdr.icmp))
                                                return (PF_DROP);
                                        pd->proto = IPPROTO_ICMPV6;
                                }
#endif /* INET6 */
                                pf_patch_16(pd,
                                    &pd->hdr.icmp.icmp_id, nk->port[iidx]);

                                m_copyback(pd->m, pd->off, ICMP_MINLEN,
                                    &pd->hdr.icmp, M_NOWAIT);
                                copyback = 1;
                                break;
#ifdef INET6
                        case AF_INET6:
                                if (afto) {
                                        if (pf_translate_icmp_af(pd, AF_INET,
                                            &pd->hdr.icmp6))
                                                return (PF_DROP);
                                        pd->proto = IPPROTO_ICMP;
                                }

                                pf_patch_16(pd,
                                    &pd->hdr.icmp6.icmp6_id, nk->port[iidx]);

                                m_copyback(pd->m, pd->off,
                                    sizeof(struct icmp6_hdr), &pd->hdr.icmp6,
                                    M_NOWAIT);
                                copyback = 1;
                                break;
#endif /* INET6 */
                        }
#ifdef  INET6
                        if (afto)
                                return (PF_AFRT);
#endif /* INET6 */
                }
        } else {
                /*
                 * ICMP error message in response to a TCP/UDP packet.
                 * Extract the inner TCP/UDP header and search for that state.
                 */
                struct pf_pdesc  pd2;
                struct ip        h2;
#ifdef INET6
                struct ip6_hdr   h2_6;
#endif /* INET6 */
                int              ipoff2;

                /* Initialize pd2 fields valid for both packets with pd. */
                memset(&pd2, 0, sizeof(pd2));
                pd2.af = pd->af;
                pd2.dir = pd->dir;
                pd2.kif = pd->kif;
                pd2.m = pd->m;
                pd2.rdomain = pd->rdomain;
                /* Payload packet is from the opposite direction. */
                pd2.sidx = (pd2.dir == PF_IN) ? 1 : 0;
                pd2.didx = (pd2.dir == PF_IN) ? 0 : 1;
                switch (pd->af) {
                case AF_INET:
                        /* offset of h2 in mbuf chain */
                        ipoff2 = pd->off + ICMP_MINLEN;

                        if (!pf_pull_hdr(pd2.m, ipoff2, &h2, sizeof(h2),
                            reason, pd2.af)) {
                                DPFPRINTF(LOG_NOTICE,
                                    "ICMP error message too short (ip)");
                                return (PF_DROP);
                        }
                        /*
                         * ICMP error messages don't refer to non-first
                         * fragments
                         */
                        if (h2.ip_off & htons(IP_OFFMASK)) {
                                REASON_SET(reason, PFRES_FRAG);
                                return (PF_DROP);
                        }

                        /* offset of protocol header that follows h2 */
                        pd2.off = ipoff2;
                        if (pf_walk_header(&pd2, &h2, reason) != PF_PASS)
                                return (PF_DROP);

                        pd2.tot_len = ntohs(h2.ip_len);
                        pd2.ttl = h2.ip_ttl;
                        pd2.src = (struct pf_addr *)&h2.ip_src;
                        pd2.dst = (struct pf_addr *)&h2.ip_dst;
                        break;
#ifdef INET6
                case AF_INET6:
                        ipoff2 = pd->off + sizeof(struct icmp6_hdr);

                        if (!pf_pull_hdr(pd2.m, ipoff2, &h2_6, sizeof(h2_6),
                            reason, pd2.af)) {
                                DPFPRINTF(LOG_NOTICE,
                                    "ICMP error message too short (ip6)");
                                return (PF_DROP);
                        }

                        pd2.off = ipoff2;
                        if (pf_walk_header6(&pd2, &h2_6, reason) != PF_PASS)
                                return (PF_DROP);

                        pd2.tot_len = ntohs(h2_6.ip6_plen) +
                            sizeof(struct ip6_hdr);
                        pd2.ttl = h2_6.ip6_hlim;
                        pd2.src = (struct pf_addr *)&h2_6.ip6_src;
                        pd2.dst = (struct pf_addr *)&h2_6.ip6_dst;
                        break;
#endif /* INET6 */
                default:
                        unhandled_af(pd->af);
                }

                if (PF_ANEQ(pd->dst, pd2.src, pd->af)) {
                        if (pf_status.debug >= LOG_NOTICE) {
                                log(LOG_NOTICE,
                                    "pf: BAD ICMP %d:%d outer dst: ",
                                    icmptype, icmpcode);
                                pf_print_host(pd->src, 0, pd->af);
                                addlog(" -> ");
                                pf_print_host(pd->dst, 0, pd->af);
                                addlog(" inner src: ");
                                pf_print_host(pd2.src, 0, pd2.af);
                                addlog(" -> ");
                                pf_print_host(pd2.dst, 0, pd2.af);
                                addlog("\n");
                        }
                        REASON_SET(reason, PFRES_BADSTATE);
                        return (PF_DROP);
                }

                switch (pd2.proto) {
                case IPPROTO_TCP: {
                        struct tcphdr           *th = &pd2.hdr.tcp;
                        u_int32_t                seq;
                        struct pf_state_peer    *src, *dst;
                        u_int8_t                 dws;
                        int                      action;

                        /*
                         * Only the first 8 bytes of the TCP header can be
                         * expected. Don't access any TCP header fields after
                         * th_seq, an ackskew test is not possible.
                         */
                        if (!pf_pull_hdr(pd2.m, pd2.off, th, 8, reason,
                            pd2.af)) {
                                DPFPRINTF(LOG_NOTICE,
                                    "ICMP error message too short (tcp)");
                                return (PF_DROP);
                        }

                        key.af = pd2.af;
                        key.proto = IPPROTO_TCP;
                        key.rdomain = pd2.rdomain;
                        pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af);
                        pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af);
                        key.port[pd2.sidx] = th->th_sport;
                        key.port[pd2.didx] = th->th_dport;
                        key.hash = pf_pkt_hash(pd2.af, pd2.proto,
                            pd2.src, pd2.dst, th->th_sport, th->th_dport);

                        action = pf_find_state(&pd2, &key, stp);
                        if (action != PF_MATCH)
                                return (action);

                        if (pd2.dir == (*stp)->direction) {
                                if (PF_REVERSED_KEY((*stp)->key, pd->af)) {
                                        src = &(*stp)->src;
                                        dst = &(*stp)->dst;
                                } else {
                                        src = &(*stp)->dst;
                                        dst = &(*stp)->src;
                                }
                        } else {
                                if (PF_REVERSED_KEY((*stp)->key, pd->af)) {
                                        src = &(*stp)->dst;
                                        dst = &(*stp)->src;
                                } else {
                                        src = &(*stp)->src;
                                        dst = &(*stp)->dst;
                                }
                        }

                        if (src->wscale && dst->wscale)
                                dws = dst->wscale & PF_WSCALE_MASK;
                        else
                                dws = 0;

                        /* Demodulate sequence number */
                        seq = ntohl(th->th_seq) - src->seqdiff;
                        if (src->seqdiff) {
                                pf_patch_32(pd, &th->th_seq, htonl(seq));
                                copyback = 1;
                        }

                        if (!((*stp)->state_flags & PFSTATE_SLOPPY) &&
                            (!SEQ_GEQ(src->seqhi, seq) || !SEQ_GEQ(seq,
                            src->seqlo - (dst->max_win << dws)))) {
                                if (pf_status.debug >= LOG_NOTICE) {
                                        log(LOG_NOTICE,
                                            "pf: BAD ICMP %d:%d ",
                                            icmptype, icmpcode);
                                        pf_print_host(pd->src, 0, pd->af);
                                        addlog(" -> ");
                                        pf_print_host(pd->dst, 0, pd->af);
                                        addlog(" state: ");
                                        pf_print_state(*stp);
                                        addlog(" seq=%u\n", seq);
                                }
                                REASON_SET(reason, PFRES_BADSTATE);
                                return (PF_DROP);
                        } else {
                                if (pf_status.debug >= LOG_DEBUG) {
                                        log(LOG_DEBUG,
                                            "pf: OK ICMP %d:%d ",
                                            icmptype, icmpcode);
                                        pf_print_host(pd->src, 0, pd->af);
                                        addlog(" -> ");
                                        pf_print_host(pd->dst, 0, pd->af);
                                        addlog(" state: ");
                                        pf_print_state(*stp);
                                        addlog(" seq=%u\n", seq);
                                }
                        }

                        /* translate source/destination address, if necessary */
                        if ((*stp)->key[PF_SK_WIRE] !=
                            (*stp)->key[PF_SK_STACK]) {
                                struct pf_state_key     *nk;
                                int                      afto, sidx, didx;

                                if (PF_REVERSED_KEY((*stp)->key, pd->af))
                                        nk = (*stp)->key[pd->sidx];
                                else
                                        nk = (*stp)->key[pd->didx];

                                afto = pd->af != nk->af;
                                sidx = afto ? pd2.didx : pd2.sidx;
                                didx = afto ? pd2.sidx : pd2.didx;

#ifdef INET6
                                if (afto) {
                                        if (pf_translate_icmp_af(pd, nk->af,
                                            &pd->hdr.icmp))
                                                return (PF_DROP);
                                        m_copyback(pd->m, pd->off,
                                            sizeof(struct icmp6_hdr),
                                            &pd->hdr.icmp6, M_NOWAIT);
                                        if (pf_change_icmp_af(pd->m, ipoff2,
                                            pd, &pd2, &nk->addr[sidx],
                                            &nk->addr[didx], pd->af, nk->af))
                                                return (PF_DROP);
                                        pd->m->m_pkthdr.ph_rtableid =
                                            nk->rdomain;
                                        pd->destchg = 1;
                                        pf_addrcpy(&pd->nsaddr,
                                            &nk->addr[pd2.sidx], nk->af);
                                        pf_addrcpy(&pd->ndaddr,
                                            &nk->addr[pd2.didx], nk->af);
                                        if (nk->af == AF_INET) {
                                                pd->proto = IPPROTO_ICMP;
                                        } else {
                                                pd->proto = IPPROTO_ICMPV6;
                                                /*
                                                 * IPv4 becomes IPv6 so we must
                                                 * copy IPv4 src addr to least
                                                 * 32bits in IPv6 address to
                                                 * keep traceroute/icmp
                                                 * working.
                                                 */
                                                pd->nsaddr.addr32[3] =
                                                    pd->src->addr32[0];
                                        }
                                        pd->naf = nk->af;

                                        pf_patch_16(pd,
                                            &th->th_sport, nk->port[sidx]);
                                        pf_patch_16(pd,
                                            &th->th_dport, nk->port[didx]);

                                        m_copyback(pd2.m, pd2.off, 8, th,
                                            M_NOWAIT);
                                        return (PF_AFRT);
                                }
#endif  /* INET6 */
                                if (PF_ANEQ(pd2.src,
                                    &nk->addr[pd2.sidx], pd2.af) ||
                                    nk->port[pd2.sidx] != th->th_sport)
                                        pf_translate_icmp(pd, pd2.src,
                                            &th->th_sport, pd->dst,
                                            &nk->addr[pd2.sidx],
                                            nk->port[pd2.sidx]);

                                if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx],
                                    pd2.af) || pd2.rdomain != nk->rdomain)
                                        pd->destchg = 1;
                                pd->m->m_pkthdr.ph_rtableid = nk->rdomain;

                                if (PF_ANEQ(pd2.dst,
                                    &nk->addr[pd2.didx], pd2.af) ||
                                    nk->port[pd2.didx] != th->th_dport)
                                        pf_translate_icmp(pd, pd2.dst,
                                            &th->th_dport, pd->src,
                                            &nk->addr[pd2.didx],
                                            nk->port[pd2.didx]);
                                copyback = 1;
                        }

                        if (copyback) {
                                switch (pd2.af) {
                                case AF_INET:
                                        m_copyback(pd->m, pd->off, ICMP_MINLEN,
                                            &pd->hdr.icmp, M_NOWAIT);
                                        m_copyback(pd2.m, ipoff2, sizeof(h2),
                                            &h2, M_NOWAIT);
                                        break;
#ifdef INET6
                                case AF_INET6:
                                        m_copyback(pd->m, pd->off,
                                            sizeof(struct icmp6_hdr),
                                            &pd->hdr.icmp6, M_NOWAIT);
                                        m_copyback(pd2.m, ipoff2, sizeof(h2_6),
                                            &h2_6, M_NOWAIT);
                                        break;
#endif /* INET6 */
                                }
                                m_copyback(pd2.m, pd2.off, 8, th, M_NOWAIT);
                        }
                        break;
                }
                case IPPROTO_UDP: {
                        struct udphdr   *uh = &pd2.hdr.udp;
                        int              action;

                        if (!pf_pull_hdr(pd2.m, pd2.off, uh, sizeof(*uh),
                            reason, pd2.af)) {
                                DPFPRINTF(LOG_NOTICE,
                                    "ICMP error message too short (udp)");
                                return (PF_DROP);
                        }

                        key.af = pd2.af;
                        key.proto = IPPROTO_UDP;
                        key.rdomain = pd2.rdomain;
                        pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af);
                        pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af);
                        key.port[pd2.sidx] = uh->uh_sport;
                        key.port[pd2.didx] = uh->uh_dport;
                        key.hash = pf_pkt_hash(pd2.af, pd2.proto,
                            pd2.src, pd2.dst, uh->uh_sport, uh->uh_dport);

                        action = pf_find_state(&pd2, &key, stp);
                        if (action != PF_MATCH)
                                return (action);

                        /* translate source/destination address, if necessary */
                        if ((*stp)->key[PF_SK_WIRE] !=
                            (*stp)->key[PF_SK_STACK]) {
                                struct pf_state_key     *nk;
                                int                      afto, sidx, didx;

                                if (PF_REVERSED_KEY((*stp)->key, pd->af))
                                        nk = (*stp)->key[pd->sidx];
                                else
                                        nk = (*stp)->key[pd->didx];

                                afto = pd->af != nk->af;
                                sidx = afto ? pd2.didx : pd2.sidx;
                                didx = afto ? pd2.sidx : pd2.didx;

#ifdef INET6
                                if (afto) {
                                        if (pf_translate_icmp_af(pd, nk->af,
                                            &pd->hdr.icmp))
                                                return (PF_DROP);
                                        m_copyback(pd->m, pd->off,
                                            sizeof(struct icmp6_hdr),
                                            &pd->hdr.icmp6, M_NOWAIT);
                                        if (pf_change_icmp_af(pd->m, ipoff2,
                                            pd, &pd2, &nk->addr[sidx],
                                            &nk->addr[didx], pd->af, nk->af))
                                                return (PF_DROP);
                                        pd->m->m_pkthdr.ph_rtableid =
                                            nk->rdomain;
                                        pd->destchg = 1;
                                        pf_addrcpy(&pd->nsaddr,
                                            &nk->addr[pd2.sidx], nk->af);
                                        pf_addrcpy(&pd->ndaddr,
                                            &nk->addr[pd2.didx], nk->af);
                                        if (nk->af == AF_INET) {
                                                pd->proto = IPPROTO_ICMP;
                                        } else {
                                                pd->proto = IPPROTO_ICMPV6;
                                                /*
                                                 * IPv4 becomes IPv6 so we must
                                                 * copy IPv4 src addr to least
                                                 * 32bits in IPv6 address to
                                                 * keep traceroute/icmp
                                                 * working.
                                                 */
                                                pd->nsaddr.addr32[3] =
                                                    pd->src->addr32[0];
                                        }
                                        pd->naf = nk->af;

                                        pf_patch_16(pd,
                                            &uh->uh_sport, nk->port[sidx]);
                                        pf_patch_16(pd,
                                            &uh->uh_dport, nk->port[didx]);

                                        m_copyback(pd2.m, pd2.off, sizeof(*uh),
                                            uh, M_NOWAIT);
                                        return (PF_AFRT);
                                }
#endif /* INET6 */

                                if (PF_ANEQ(pd2.src,
                                    &nk->addr[pd2.sidx], pd2.af) ||
                                    nk->port[pd2.sidx] != uh->uh_sport)
                                        pf_translate_icmp(pd, pd2.src,
                                            &uh->uh_sport, pd->dst,
                                            &nk->addr[pd2.sidx],
                                            nk->port[pd2.sidx]);

                                if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx],
                                    pd2.af) || pd2.rdomain != nk->rdomain)
                                        pd->destchg = 1;
                                pd->m->m_pkthdr.ph_rtableid = nk->rdomain;

                                if (PF_ANEQ(pd2.dst,
                                    &nk->addr[pd2.didx], pd2.af) ||
                                    nk->port[pd2.didx] != uh->uh_dport)
                                        pf_translate_icmp(pd, pd2.dst,
                                            &uh->uh_dport, pd->src,
                                            &nk->addr[pd2.didx],
                                            nk->port[pd2.didx]);

                                switch (pd2.af) {
                                case AF_INET:
                                        m_copyback(pd->m, pd->off, ICMP_MINLEN,
                                            &pd->hdr.icmp, M_NOWAIT);
                                        m_copyback(pd2.m, ipoff2, sizeof(h2),
                                            &h2, M_NOWAIT);
                                        break;
#ifdef INET6
                                case AF_INET6:
                                        m_copyback(pd->m, pd->off,
                                            sizeof(struct icmp6_hdr),
                                            &pd->hdr.icmp6, M_NOWAIT);
                                        m_copyback(pd2.m, ipoff2, sizeof(h2_6),
                                            &h2_6, M_NOWAIT);
                                        break;
#endif /* INET6 */
                                }
                                /* Avoid recomputing quoted UDP checksum.
                                 * note: udp6 0 csum invalid per rfc2460 p27.
                                 * but presumed nothing cares in this context */
                                pf_patch_16(pd, &uh->uh_sum, 0);
                                m_copyback(pd2.m, pd2.off, sizeof(*uh), uh,
                                    M_NOWAIT);
                                copyback = 1;
                        }
                        break;
                }
                case IPPROTO_ICMP: {
                        struct icmp     *iih = &pd2.hdr.icmp;

                        if (pd2.af != AF_INET) {
                                REASON_SET(reason, PFRES_NORM);
                                return (PF_DROP);
                        }

                        if (!pf_pull_hdr(pd2.m, pd2.off, iih, ICMP_MINLEN,
                            reason, pd2.af)) {
                                DPFPRINTF(LOG_NOTICE,
                                    "ICMP error message too short (icmp)");
                                return (PF_DROP);
                        }

                        pf_icmp_mapping(&pd2, iih->icmp_type,
                            &icmp_dir, &virtual_id, &virtual_type);

                        ret = pf_icmp_state_lookup(&pd2, &key, stp,
                            virtual_id, virtual_type, icmp_dir, &iidx, 0, 1);
                        if (ret >= 0)
                                return (ret);

                        /* translate source/destination address, if necessary */
                        if ((*stp)->key[PF_SK_WIRE] !=
                            (*stp)->key[PF_SK_STACK]) {
                                struct pf_state_key     *nk;
                                int                      afto, sidx, didx;

                                if (PF_REVERSED_KEY((*stp)->key, pd->af))
                                        nk = (*stp)->key[pd->sidx];
                                else
                                        nk = (*stp)->key[pd->didx];

                                afto = pd->af != nk->af;
                                sidx = afto ? pd2.didx : pd2.sidx;
                                didx = afto ? pd2.sidx : pd2.didx;
                                iidx = afto ? !iidx : iidx;

#ifdef INET6
                                if (afto) {
                                        if (nk->af != AF_INET6)
                                                return (PF_DROP);
                                        if (pf_translate_icmp_af(pd, nk->af,
                                            &pd->hdr.icmp))
                                                return (PF_DROP);
                                        m_copyback(pd->m, pd->off,
                                            sizeof(struct icmp6_hdr),
                                            &pd->hdr.icmp6, M_NOWAIT);
                                        if (pf_change_icmp_af(pd->m, ipoff2,
                                            pd, &pd2, &nk->addr[sidx],
                                            &nk->addr[didx], pd->af, nk->af))
                                                return (PF_DROP);
                                        pd->proto = IPPROTO_ICMPV6;
                                        if (pf_translate_icmp_af(pd,
                                                nk->af, iih))
                                                return (PF_DROP);
                                        if (virtual_type == htons(ICMP_ECHO))
                                                pf_patch_16(pd, &iih->icmp_id,
                                                    nk->port[iidx]);
                                        m_copyback(pd2.m, pd2.off, ICMP_MINLEN,
                                            iih, M_NOWAIT);
                                        pd->m->m_pkthdr.ph_rtableid =
                                            nk->rdomain;
                                        pd->destchg = 1;
                                        pf_addrcpy(&pd->nsaddr,
                                            &nk->addr[pd2.sidx], nk->af);
                                        pf_addrcpy(&pd->ndaddr,
                                            &nk->addr[pd2.didx], nk->af);
                                        /*
                                         * IPv4 becomes IPv6 so we must copy
                                         * IPv4 src addr to least 32bits in
                                         * IPv6 address to keep traceroute
                                         * working.
                                         */
                                        pd->nsaddr.addr32[3] =
                                            pd->src->addr32[0];
                                        pd->naf = nk->af;
                                        return (PF_AFRT);
                                }
#endif /* INET6 */

                                if (PF_ANEQ(pd2.src,
                                    &nk->addr[pd2.sidx], pd2.af) ||
                                    (virtual_type == htons(ICMP_ECHO) &&
                                    nk->port[iidx] != iih->icmp_id))
                                        pf_translate_icmp(pd, pd2.src,
                                            (virtual_type == htons(ICMP_ECHO)) ?
                                            &iih->icmp_id : NULL,
                                            pd->dst, &nk->addr[pd2.sidx],
                                            (virtual_type == htons(ICMP_ECHO)) ?
                                            nk->port[iidx] : 0);

                                if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx],
                                    pd2.af) || pd2.rdomain != nk->rdomain)
                                        pd->destchg = 1;
                                pd->m->m_pkthdr.ph_rtableid = nk->rdomain;

                                if (PF_ANEQ(pd2.dst,
                                    &nk->addr[pd2.didx], pd2.af))
                                        pf_translate_icmp(pd, pd2.dst, NULL,
                                            pd->src, &nk->addr[pd2.didx], 0);

                                m_copyback(pd->m, pd->off, ICMP_MINLEN,
                                    &pd->hdr.icmp, M_NOWAIT);
                                m_copyback(pd2.m, ipoff2, sizeof(h2), &h2,
                                    M_NOWAIT);
                                m_copyback(pd2.m, pd2.off, ICMP_MINLEN, iih,
                                    M_NOWAIT);
                                copyback = 1;
                        }
                        break;
                }
#ifdef INET6
                case IPPROTO_ICMPV6: {
                        struct icmp6_hdr        *iih = &pd2.hdr.icmp6;

                        if (pd2.af != AF_INET6) {
                                REASON_SET(reason, PFRES_NORM);
                                return (PF_DROP);
                        }

                        if (!pf_pull_hdr(pd2.m, pd2.off, iih,
                            sizeof(struct icmp6_hdr), reason, pd2.af)) {
                                DPFPRINTF(LOG_NOTICE,
                                    "ICMP error message too short (icmp6)");
                                return (PF_DROP);
                        }

                        pf_icmp_mapping(&pd2, iih->icmp6_type,
                            &icmp_dir, &virtual_id, &virtual_type);
                        ret = pf_icmp_state_lookup(&pd2, &key, stp,
                            virtual_id, virtual_type, icmp_dir, &iidx, 0, 1);
                        /* IPv6? try matching a multicast address */
                        if (ret == PF_DROP && pd2.af == AF_INET6 &&
                            icmp_dir == PF_OUT)
                                ret = pf_icmp_state_lookup(&pd2, &key, stp,
                                    virtual_id, virtual_type, icmp_dir, &iidx,
                                    1, 1);
                        if (ret >= 0)
                                return (ret);

                        /* translate source/destination address, if necessary */
                        if ((*stp)->key[PF_SK_WIRE] !=
                            (*stp)->key[PF_SK_STACK]) {
                                struct pf_state_key     *nk;
                                int                      afto, sidx, didx;

                                if (PF_REVERSED_KEY((*stp)->key, pd->af))
                                        nk = (*stp)->key[pd->sidx];
                                else
                                        nk = (*stp)->key[pd->didx];

                                afto = pd->af != nk->af;
                                sidx = afto ? pd2.didx : pd2.sidx;
                                didx = afto ? pd2.sidx : pd2.didx;
                                iidx = afto ? !iidx : iidx;

                                if (afto) {
                                        if (nk->af != AF_INET)
                                                return (PF_DROP);
                                        if (pf_translate_icmp_af(pd, nk->af,
                                            &pd->hdr.icmp))
                                                return (PF_DROP);
                                        m_copyback(pd->m, pd->off,
                                            sizeof(struct icmp6_hdr),
                                            &pd->hdr.icmp6, M_NOWAIT);
                                        if (pf_change_icmp_af(pd->m, ipoff2,
                                            pd, &pd2, &nk->addr[sidx],
                                            &nk->addr[didx], pd->af, nk->af))
                                                return (PF_DROP);
                                        pd->proto = IPPROTO_ICMP;
                                        if (pf_translate_icmp_af(pd,
                                                nk->af, iih))
                                                return (PF_DROP);
                                        if (virtual_type ==
                                            htons(ICMP6_ECHO_REQUEST))
                                                pf_patch_16(pd, &iih->icmp6_id,
                                                    nk->port[iidx]);
                                        m_copyback(pd2.m, pd2.off,
                                            sizeof(struct icmp6_hdr), iih,
                                            M_NOWAIT);
                                        pd->m->m_pkthdr.ph_rtableid =
                                            nk->rdomain;
                                        pd->destchg = 1;
                                        pf_addrcpy(&pd->nsaddr,
                                            &nk->addr[pd2.sidx], nk->af);
                                        pf_addrcpy(&pd->ndaddr,
                                            &nk->addr[pd2.didx], nk->af);
                                        pd->naf = nk->af;
                                        return (PF_AFRT);
                                }

                                if (PF_ANEQ(pd2.src,
                                    &nk->addr[pd2.sidx], pd2.af) ||
                                    ((virtual_type ==
                                    htons(ICMP6_ECHO_REQUEST)) &&
                                    nk->port[pd2.sidx] != iih->icmp6_id))
                                        pf_translate_icmp(pd, pd2.src,
                                            (virtual_type ==
                                            htons(ICMP6_ECHO_REQUEST))
                                            ? &iih->icmp6_id : NULL,
                                            pd->dst, &nk->addr[pd2.sidx],
                                            (virtual_type ==
                                            htons(ICMP6_ECHO_REQUEST))
                                            ? nk->port[iidx] : 0);

                                if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx],
                                    pd2.af) || pd2.rdomain != nk->rdomain)
                                        pd->destchg = 1;
                                pd->m->m_pkthdr.ph_rtableid = nk->rdomain;

                                if (PF_ANEQ(pd2.dst,
                                    &nk->addr[pd2.didx], pd2.af))
                                        pf_translate_icmp(pd, pd2.dst, NULL,
                                            pd->src, &nk->addr[pd2.didx], 0);

                                m_copyback(pd->m, pd->off,
                                    sizeof(struct icmp6_hdr), &pd->hdr.icmp6,
                                    M_NOWAIT);
                                m_copyback(pd2.m, ipoff2, sizeof(h2_6), &h2_6,
                                    M_NOWAIT);
                                m_copyback(pd2.m, pd2.off,
                                    sizeof(struct icmp6_hdr), iih, M_NOWAIT);
                                copyback = 1;
                        }
                        break;
                }
#endif /* INET6 */
                default: {
                        int     action;

                        key.af = pd2.af;
                        key.proto = pd2.proto;
                        key.rdomain = pd2.rdomain;
                        pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af);
                        pf_addrcpy(&key.addr[pd2.didx], pd2.dst, key.af);
                        key.port[0] = key.port[1] = 0;
                        key.hash = pf_pkt_hash(pd2.af, pd2.proto,
                            pd2.src, pd2.dst, 0, 0);

                        action = pf_find_state(&pd2, &key, stp);
                        if (action != PF_MATCH)
                                return (action);

                        /* translate source/destination address, if necessary */
                        if ((*stp)->key[PF_SK_WIRE] !=
                            (*stp)->key[PF_SK_STACK]) {
                                struct pf_state_key *nk =
                                    (*stp)->key[pd->didx];

                                if (PF_ANEQ(pd2.src,
                                    &nk->addr[pd2.sidx], pd2.af))
                                        pf_translate_icmp(pd, pd2.src, NULL,
                                            pd->dst, &nk->addr[pd2.sidx], 0);

                                if (PF_ANEQ(pd2.dst, &nk->addr[pd2.didx],
                                    pd2.af) || pd2.rdomain != nk->rdomain)
                                        pd->destchg = 1;
                                pd->m->m_pkthdr.ph_rtableid = nk->rdomain;

                                if (PF_ANEQ(pd2.dst,
                                    &nk->addr[pd2.didx], pd2.af))
                                        pf_translate_icmp(pd, pd2.dst, NULL,
                                            pd->src, &nk->addr[pd2.didx], 0);

                                switch (pd2.af) {
                                case AF_INET:
                                        m_copyback(pd->m, pd->off, ICMP_MINLEN,
                                            &pd->hdr.icmp, M_NOWAIT);
                                        m_copyback(pd2.m, ipoff2, sizeof(h2),
                                            &h2, M_NOWAIT);
                                        break;
#ifdef INET6
                                case AF_INET6:
                                        m_copyback(pd->m, pd->off,
                                            sizeof(struct icmp6_hdr),
                                            &pd->hdr.icmp6, M_NOWAIT);
                                        m_copyback(pd2.m, ipoff2, sizeof(h2_6),
                                            &h2_6, M_NOWAIT);
                                        break;
#endif /* INET6 */
                                }
                                copyback = 1;
                        }
                        break;
                }
                }
        }
        if (copyback) {
                m_copyback(pd->m, pd->off, pd->hdrlen, &pd->hdr, M_NOWAIT);
        }

        return (PF_PASS);
}

/*
 * ipoff and off are measured from the start of the mbuf chain.
 * h must be at "ipoff" on the mbuf chain.
 */
void *
pf_pull_hdr(struct mbuf *m, int off, void *p, int len,
    u_short *reasonp, sa_family_t af)
{
        int iplen = 0;

        switch (af) {
        case AF_INET: {
                struct ip       *h = mtod(m, struct ip *);
                u_int16_t        fragoff = (ntohs(h->ip_off) & IP_OFFMASK) << 3;

                if (fragoff) {
                        REASON_SET(reasonp, PFRES_FRAG);
                        return (NULL);
                }
                iplen = ntohs(h->ip_len);
                break;
        }
#ifdef INET6
        case AF_INET6: {
                struct ip6_hdr  *h = mtod(m, struct ip6_hdr *);

                iplen = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr);
                break;
        }
#endif /* INET6 */
        }
        if (m->m_pkthdr.len < off + len || iplen < off + len) {
                REASON_SET(reasonp, PFRES_SHORT);
                return (NULL);
        }
        m_copydata(m, off, len, p);
        return (p);
}

int
pf_routable(struct pf_addr *addr, sa_family_t af, struct pfi_kif *kif,
    int rtableid)
{
        struct sockaddr_storage  ss;
        struct sockaddr_in      *dst;
        int                      ret = 1;
        int                      check_mpath;
#ifdef INET6
        struct sockaddr_in6     *dst6;
#endif  /* INET6 */
        struct rtentry          *rt = NULL;

        check_mpath = 0;
        memset(&ss, 0, sizeof(ss));
        switch (af) {
        case AF_INET:
                dst = (struct sockaddr_in *)&ss;
                dst->sin_family = AF_INET;
                dst->sin_len = sizeof(*dst);
                dst->sin_addr = addr->v4;
                if (atomic_load_int(&ipmultipath))
                        check_mpath = 1;
                break;
#ifdef INET6
        case AF_INET6:
                /*
                 * Skip check for addresses with embedded interface scope,
                 * as they would always match anyway.
                 */
                if (IN6_IS_SCOPE_EMBED(&addr->v6))
                        goto out;
                dst6 = (struct sockaddr_in6 *)&ss;
                dst6->sin6_family = AF_INET6;
                dst6->sin6_len = sizeof(*dst6);
                dst6->sin6_addr = addr->v6;
                if (atomic_load_int(&ip6_multipath))
                        check_mpath = 1;
                break;
#endif /* INET6 */
        }

        /* Skip checks for ipsec interfaces */
        if (kif != NULL && kif->pfik_ifp->if_type == IFT_ENC)
                goto out;

        rt = rtalloc(sstosa(&ss), 0, rtableid);
        if (rt != NULL) {
                /* No interface given, this is a no-route check */
                if (kif == NULL)
                        goto out;

                if (kif->pfik_ifp == NULL) {
                        ret = 0;
                        goto out;
                }

                /* Perform uRPF check if passed input interface */
                ret = 0;
                do {
                        if (rt->rt_ifidx == kif->pfik_ifp->if_index) {
                                ret = 1;
#if NCARP > 0
                        } else {
                                struct ifnet *ifp;

                                smr_read_enter();
                                ifp = if_get_smr(rt->rt_ifidx);
                                if (ifp != NULL && ifp->if_type == IFT_CARP &&
                                    ifp->if_carpdevidx ==
                                    kif->pfik_ifp->if_index)
                                        ret = 1;
                                smr_read_leave();
#endif /* NCARP */
                        }

                        rt = rtable_iterate(rt);
                } while (check_mpath == 1 && rt != NULL && ret == 0);
        } else
                ret = 0;
out:
        rtfree(rt);
        return (ret);
}

int
pf_rtlabel_match(struct pf_addr *addr, sa_family_t af, struct pf_addr_wrap *aw,
    int rtableid)
{
        struct sockaddr_storage  ss;
        struct sockaddr_in      *dst;
#ifdef INET6
        struct sockaddr_in6     *dst6;
#endif  /* INET6 */
        struct rtentry          *rt;
        int                      ret = 0;

        memset(&ss, 0, sizeof(ss));
        switch (af) {
        case AF_INET:
                dst = (struct sockaddr_in *)&ss;
                dst->sin_family = AF_INET;
                dst->sin_len = sizeof(*dst);
                dst->sin_addr = addr->v4;
                break;
#ifdef INET6
        case AF_INET6:
                dst6 = (struct sockaddr_in6 *)&ss;
                dst6->sin6_family = AF_INET6;
                dst6->sin6_len = sizeof(*dst6);
                dst6->sin6_addr = addr->v6;
                break;
#endif /* INET6 */
        }

        rt = rtalloc(sstosa(&ss), RT_RESOLVE, rtableid);
        if (rt != NULL) {
                if (rt->rt_labelid == aw->v.rtlabel)
                        ret = 1;
                rtfree(rt);
        }

        return (ret);
}

/* pf_route() may change pd->m, adjust local copies after calling */
void
pf_route(struct pf_pdesc *pd, struct pf_state *st)
{
        struct mbuf             *m0;
        struct mbuf_list         ml;
        struct sockaddr_in      *dst, sin;
        struct rtentry          *rt = NULL;
        struct ip               *ip;
        struct ifnet            *ifp = NULL;
        unsigned int             rtableid;

        if (pd->m->m_pkthdr.pf.routed++ > 3) {
                m_freem(pd->m);
                pd->m = NULL;
                return;
        }

        if (st->rt == PF_DUPTO) {
                if ((m0 = m_dup_pkt(pd->m, max_linkhdr, M_NOWAIT)) == NULL)
                        return;
        } else {
                if ((st->rt == PF_REPLYTO) == (st->direction == pd->dir))
                        return;
                m0 = pd->m;
                pd->m = NULL;
        }

        if (m0->m_len < sizeof(struct ip)) {
                DPFPRINTF(LOG_ERR,
                    "%s: m0->m_len < sizeof(struct ip)", __func__);
                goto bad;
        }

        ip = mtod(m0, struct ip *);

        if (pd->dir == PF_IN) {
                if (ip->ip_ttl <= IPTTLDEC) {
                        if (st->rt != PF_DUPTO) {
                                pf_send_icmp(m0, ICMP_TIMXCEED,
                                    ICMP_TIMXCEED_INTRANS, 0,
                                    pd->af, st->rule.ptr, pd->rdomain);
                        }
                        goto bad;
                }
                ip->ip_ttl -= IPTTLDEC;
        }

        memset(&sin, 0, sizeof(sin));
        dst = &sin;
        dst->sin_family = AF_INET;
        dst->sin_len = sizeof(*dst);
        dst->sin_addr = st->rt_addr.v4;
        rtableid = m0->m_pkthdr.ph_rtableid;

        rt = rtalloc_mpath(sintosa(dst), &ip->ip_src.s_addr, rtableid);
        if (!rtisvalid(rt)) {
                if (st->rt != PF_DUPTO) {
                        pf_send_icmp(m0, ICMP_UNREACH, ICMP_UNREACH_HOST,
                            0, pd->af, st->rule.ptr, pd->rdomain);
                }
                ipstat_inc(ips_noroute);
                goto bad;
        }

        ifp = if_get(rt->rt_ifidx);
        if (ifp == NULL)
                goto bad;

        /* A locally generated packet may have invalid source address. */
        if ((ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET &&
            (ifp->if_flags & IFF_LOOPBACK) == 0)
                ip->ip_src = ifatoia(rt->rt_ifa)->ia_addr.sin_addr;

        if (st->rt != PF_DUPTO && pd->dir == PF_IN) {
                if (pf_test(AF_INET, PF_OUT, ifp, &m0) != PF_PASS)
                        goto bad;
                else if (m0 == NULL)
                        goto done;
                if (m0->m_len < sizeof(struct ip)) {
                        DPFPRINTF(LOG_ERR,
                            "%s: m0->m_len < sizeof(struct ip)", __func__);
                        goto bad;
                }
                ip = mtod(m0, struct ip *);
        }

        if (if_output_tso(ifp, &m0, sintosa(dst), rt, ifp->if_mtu) ||
            m0 == NULL)
                goto done;

        /*
         * Too large for interface; fragment if possible.
         * Must be able to put at least 8 bytes per fragment.
         */
        if (ip->ip_off & htons(IP_DF)) {
                ipstat_inc(ips_cantfrag);
                if (st->rt != PF_DUPTO)
                        pf_send_icmp(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG,
                            ifp->if_mtu, pd->af, st->rule.ptr, pd->rdomain);
                goto bad;
        }

        if (ip_fragment(m0, &ml, ifp, ifp->if_mtu) ||
            if_output_ml(ifp, &ml, sintosa(dst), rt))
                goto done;
        ipstat_inc(ips_fragmented);

done:
        if_put(ifp);
        rtfree(rt);
        return;

bad:
        m_freem(m0);
        goto done;
}

#ifdef INET6
/* pf_route6() may change pd->m, adjust local copies after calling */
void
pf_route6(struct pf_pdesc *pd, struct pf_state *st)
{
        struct mbuf             *m0;
        struct sockaddr_in6     *dst, sin6;
        struct rtentry          *rt = NULL;
        struct ip6_hdr          *ip6;
        struct ifnet            *ifp = NULL;
        struct m_tag            *mtag;
        unsigned int             rtableid;

        if (pd->m->m_pkthdr.pf.routed++ > 3) {
                m_freem(pd->m);
                pd->m = NULL;
                return;
        }

        if (st->rt == PF_DUPTO) {
                if ((m0 = m_dup_pkt(pd->m, max_linkhdr, M_NOWAIT)) == NULL)
                        return;
        } else {
                if ((st->rt == PF_REPLYTO) == (st->direction == pd->dir))
                        return;
                m0 = pd->m;
                pd->m = NULL;
        }

        if (m0->m_len < sizeof(struct ip6_hdr)) {
                DPFPRINTF(LOG_ERR,
                    "%s: m0->m_len < sizeof(struct ip6_hdr)", __func__);
                goto bad;
        }
        ip6 = mtod(m0, struct ip6_hdr *);

        if (pd->dir == PF_IN) {
                if (ip6->ip6_hlim <= IPV6_HLIMDEC) {
                        if (st->rt != PF_DUPTO) {
                                pf_send_icmp(m0, ICMP6_TIME_EXCEEDED,
                                    ICMP6_TIME_EXCEED_TRANSIT, 0,
                                    pd->af, st->rule.ptr, pd->rdomain);
                        }
                        goto bad;
                }
                ip6->ip6_hlim -= IPV6_HLIMDEC;
        }

        memset(&sin6, 0, sizeof(sin6));
        dst = &sin6;
        dst->sin6_family = AF_INET6;
        dst->sin6_len = sizeof(*dst);
        dst->sin6_addr = st->rt_addr.v6;
        rtableid = m0->m_pkthdr.ph_rtableid;

        rt = rtalloc_mpath(sin6tosa(dst), &ip6->ip6_src.s6_addr32[0],
            rtableid);
        if (!rtisvalid(rt)) {
                if (st->rt != PF_DUPTO) {
                        pf_send_icmp(m0, ICMP6_DST_UNREACH,
                            ICMP6_DST_UNREACH_NOROUTE, 0,
                            pd->af, st->rule.ptr, pd->rdomain);
                }
                ip6stat_inc(ip6s_noroute);
                goto bad;
        }

        ifp = if_get(rt->rt_ifidx);
        if (ifp == NULL)
                goto bad;

        /* A locally generated packet may have invalid source address. */
        if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
            (ifp->if_flags & IFF_LOOPBACK) == 0)
                ip6->ip6_src = ifatoia6(rt->rt_ifa)->ia_addr.sin6_addr;

        if (st->rt != PF_DUPTO && pd->dir == PF_IN) {
                if (pf_test(AF_INET6, PF_OUT, ifp, &m0) != PF_PASS)
                        goto bad;
                else if (m0 == NULL)
                        goto done;
                if (m0->m_len < sizeof(struct ip6_hdr)) {
                        DPFPRINTF(LOG_ERR,
                            "%s: m0->m_len < sizeof(struct ip6_hdr)", __func__);
                        goto bad;
                }
        }

        /*
         * If packet has been reassembled by PF earlier, we have to
         * use pf_refragment6() here to turn it back to fragments.
         */
        if ((mtag = m_tag_find(m0, PACKET_TAG_PF_REASSEMBLED, NULL))) {
                (void) pf_refragment6(&m0, mtag, dst, ifp, rt);
                goto done;
        }

        if (if_output_tso(ifp, &m0, sin6tosa(dst), rt, ifp->if_mtu) ||
            m0 == NULL)
                goto done;

        ip6stat_inc(ip6s_cantfrag);
        if (st->rt != PF_DUPTO)
                pf_send_icmp(m0, ICMP6_PACKET_TOO_BIG, 0,
                    ifp->if_mtu, pd->af, st->rule.ptr, pd->rdomain);
        goto bad;

done:
        if_put(ifp);
        rtfree(rt);
        return;

bad:
        m_freem(m0);
        goto done;
}
#endif /* INET6 */

/*
 * check TCP checksum and set mbuf flag
 *   off is the offset where the protocol header starts
 *   len is the total length of protocol header plus payload
 * returns 0 when the checksum is valid, otherwise returns 1.
 * if the _OUT flag is set the checksum isn't done yet, consider these ok
 */
int
pf_check_tcp_cksum(struct mbuf *m, int off, int len, sa_family_t af)
{
        u_int16_t sum;

        if (m->m_pkthdr.csum_flags &
            (M_TCP_CSUM_IN_OK | M_TCP_CSUM_OUT)) {
                return (0);
        }
        if (m->m_pkthdr.csum_flags & M_TCP_CSUM_IN_BAD ||
            off < sizeof(struct ip) ||
            m->m_pkthdr.len < off + len) {
                return (1);
        }

        /* need to do it in software */
        tcpstat_inc(tcps_inswcsum);

        switch (af) {
        case AF_INET:
                if (m->m_len < sizeof(struct ip))
                        return (1);

                sum = in4_cksum(m, IPPROTO_TCP, off, len);
                break;
#ifdef INET6
        case AF_INET6:
                if (m->m_len < sizeof(struct ip6_hdr))
                        return (1);

                sum = in6_cksum(m, IPPROTO_TCP, off, len);
                break;
#endif /* INET6 */
        default:
                unhandled_af(af);
        }
        if (sum) {
                tcpstat_inc(tcps_rcvbadsum);
                m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_BAD;
                return (1);
        }

        m->m_pkthdr.csum_flags |= M_TCP_CSUM_IN_OK;
        return (0);
}

struct pf_divert *
pf_find_divert(struct mbuf *m)
{
        struct m_tag    *mtag;

        if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL)
                return (NULL);

        return ((struct pf_divert *)(mtag + 1));
}

struct pf_divert *
pf_get_divert(struct mbuf *m)
{
        struct m_tag    *mtag;

        if ((mtag = m_tag_find(m, PACKET_TAG_PF_DIVERT, NULL)) == NULL) {
                mtag = m_tag_get(PACKET_TAG_PF_DIVERT, sizeof(struct pf_divert),
                    M_NOWAIT);
                if (mtag == NULL)
                        return (NULL);
                memset(mtag + 1, 0, sizeof(struct pf_divert));
                m_tag_prepend(m, mtag);
        }

        return ((struct pf_divert *)(mtag + 1));
}

int
pf_walk_option(struct pf_pdesc *pd, struct ip *h, int off, int end,
    u_short *reason)
{
        uint8_t type, length, opts[15 * 4 - sizeof(struct ip)];

        /* IP header in payload of ICMP packet may be too short */
        if (pd->m->m_pkthdr.len < end) {
                DPFPRINTF(LOG_NOTICE, "IP option too short");
                REASON_SET(reason, PFRES_SHORT);
                return (PF_DROP);
        }

        KASSERT(end - off <= sizeof(opts));
        m_copydata(pd->m, off, end - off, opts);
        end -= off;
        off = 0;

        while (off < end) {
                type = opts[off];
                if (type == IPOPT_EOL)
                        break;
                if (type == IPOPT_NOP) {
                        off++;
                        continue;
                }
                if (off + 2 > end) {
                        DPFPRINTF(LOG_NOTICE, "IP length opt");
                        REASON_SET(reason, PFRES_IPOPTIONS);
                        return (PF_DROP);
                }
                length = opts[off + 1];
                if (length < 2) {
                        DPFPRINTF(LOG_NOTICE, "IP short opt");
                        REASON_SET(reason, PFRES_IPOPTIONS);
                        return (PF_DROP);
                }
                if (off + length > end) {
                        DPFPRINTF(LOG_NOTICE, "IP long opt");
                        REASON_SET(reason, PFRES_IPOPTIONS);
                        return (PF_DROP);
                }
                switch (type) {
                case IPOPT_RA:
                        SET(pd->badopts, PF_OPT_ROUTER_ALERT);
                        break;
                default:
                        SET(pd->badopts, PF_OPT_OTHER);
                        break;
                }
                off += length;
        }

        return (PF_PASS);
}

int
pf_walk_header(struct pf_pdesc *pd, struct ip *h, u_short *reason)
{
        struct ip6_ext           ext;
        u_int32_t                hlen, end;
        int                      hdr_cnt;

        hlen = h->ip_hl << 2;
        if (hlen < sizeof(struct ip) || hlen > ntohs(h->ip_len)) {
                REASON_SET(reason, PFRES_SHORT);
                return (PF_DROP);
        }
        if (hlen != sizeof(struct ip)) {
                if (pf_walk_option(pd, h, pd->off + sizeof(struct ip),
                    pd->off + hlen, reason) != PF_PASS)
                        return (PF_DROP);
                /* header options which contain only padding is fishy */
                if (pd->badopts == 0)
                        SET(pd->badopts, PF_OPT_OTHER);
        }
        end = pd->off + ntohs(h->ip_len);
        pd->off += hlen;
        pd->proto = h->ip_p;
        /* IGMP packets have router alert options, allow them */
        if (pd->proto == IPPROTO_IGMP) {
                /*
                 * According to RFC 1112 ttl must be set to 1 in all IGMP
                 * packets sent to 224.0.0.1
                 */
                if ((h->ip_ttl != 1) &&
                    (h->ip_dst.s_addr == INADDR_ALLHOSTS_GROUP)) {
                        DPFPRINTF(LOG_NOTICE, "Invalid IGMP");
                        REASON_SET(reason, PFRES_IPOPTIONS);
                        return (PF_DROP);
                }
                CLR(pd->badopts, PF_OPT_ROUTER_ALERT);
        }
        /* stop walking over non initial fragments */
        if ((h->ip_off & htons(IP_OFFMASK)) != 0)
                return (PF_PASS);

        for (hdr_cnt = 0; hdr_cnt < pf_hdr_limit; hdr_cnt++) {
                switch (pd->proto) {
                case IPPROTO_AH:
                        /* fragments may be short */
                        if ((h->ip_off & htons(IP_MF | IP_OFFMASK)) != 0 &&
                            end < pd->off + sizeof(ext))
                                return (PF_PASS);
                        if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext),
                            reason, AF_INET)) {
                                DPFPRINTF(LOG_NOTICE, "IP short exthdr");
                                return (PF_DROP);
                        }
                        pd->off += (ext.ip6e_len + 2) * 4;
                        pd->proto = ext.ip6e_nxt;
                        break;
                default:
                        return (PF_PASS);
                }
        }
        DPFPRINTF(LOG_NOTICE, "IPv4 nested authentication header limit");
        REASON_SET(reason, PFRES_IPOPTIONS);
        return (PF_DROP);
}

#ifdef INET6
int
pf_walk_option6(struct pf_pdesc *pd, struct ip6_hdr *h, int off, int end,
    u_short *reason)
{
        struct ip6_opt           opt;
        struct ip6_opt_jumbo     jumbo;

        while (off < end) {
                if (!pf_pull_hdr(pd->m, off, &opt.ip6o_type,
                    sizeof(opt.ip6o_type), reason, AF_INET6)) {
                        DPFPRINTF(LOG_NOTICE, "IPv6 short opt type");
                        return (PF_DROP);
                }
                if (opt.ip6o_type == IP6OPT_PAD1) {
                        off++;
                        continue;
                }
                if (!pf_pull_hdr(pd->m, off, &opt, sizeof(opt),
                    reason, AF_INET6)) {
                        DPFPRINTF(LOG_NOTICE, "IPv6 short opt");
                        return (PF_DROP);
                }
                if (off + sizeof(opt) + opt.ip6o_len > end) {
                        DPFPRINTF(LOG_NOTICE, "IPv6 long opt");
                        REASON_SET(reason, PFRES_IPOPTIONS);
                        return (PF_DROP);
                }
                switch (opt.ip6o_type) {
                case IP6OPT_PADN:
                        break;
                case IP6OPT_JUMBO:
                        SET(pd->badopts, PF_OPT_JUMBO);
                        if (pd->jumbolen != 0) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 multiple jumbo");
                                REASON_SET(reason, PFRES_IPOPTIONS);
                                return (PF_DROP);
                        }
                        if (ntohs(h->ip6_plen) != 0) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 bad jumbo plen");
                                REASON_SET(reason, PFRES_IPOPTIONS);
                                return (PF_DROP);
                        }
                        if (!pf_pull_hdr(pd->m, off, &jumbo, sizeof(jumbo),
                            reason, AF_INET6)) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 short jumbo");
                                return (PF_DROP);
                        }
                        memcpy(&pd->jumbolen, jumbo.ip6oj_jumbo_len,
                            sizeof(pd->jumbolen));
                        pd->jumbolen = ntohl(pd->jumbolen);
                        if (pd->jumbolen < IPV6_MAXPACKET) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 short jumbolen");
                                REASON_SET(reason, PFRES_IPOPTIONS);
                                return (PF_DROP);
                        }
                        break;
                case IP6OPT_ROUTER_ALERT:
                        SET(pd->badopts, PF_OPT_ROUTER_ALERT);
                        break;
                default:
                        SET(pd->badopts, PF_OPT_OTHER);
                        break;
                }
                off += sizeof(opt) + opt.ip6o_len;
        }

        return (PF_PASS);
}

int
pf_walk_header6(struct pf_pdesc *pd, struct ip6_hdr *h, u_short *reason)
{
        struct ip6_frag          frag;
        struct ip6_ext           ext;
        struct icmp6_hdr         icmp6;
        struct ip6_rthdr         rthdr;
        u_int32_t                end;
        int                      hdr_cnt, fraghdr_cnt = 0, rthdr_cnt = 0;

        pd->off += sizeof(struct ip6_hdr);
        end = pd->off + ntohs(h->ip6_plen);
        pd->fragoff = pd->extoff = pd->jumbolen = 0;
        pd->proto = h->ip6_nxt;

        for (hdr_cnt = 0; hdr_cnt < pf_hdr_limit; hdr_cnt++) {
                switch (pd->proto) {
                case IPPROTO_ROUTING:
                case IPPROTO_DSTOPTS:
                        SET(pd->badopts, PF_OPT_OTHER);
                        break;
                case IPPROTO_HOPOPTS:
                        if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext),
                            reason, AF_INET6)) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 short exthdr");
                                return (PF_DROP);
                        }
                        if (pf_walk_option6(pd, h, pd->off + sizeof(ext),
                            pd->off + (ext.ip6e_len + 1) * 8, reason)
                            != PF_PASS)
                                return (PF_DROP);
                        /* option header which contains only padding is fishy */
                        if (pd->badopts == 0)
                                SET(pd->badopts, PF_OPT_OTHER);
                        break;
                }
                switch (pd->proto) {
                case IPPROTO_FRAGMENT:
                        if (fraghdr_cnt++) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 multiple fragment");
                                REASON_SET(reason, PFRES_FRAG);
                                return (PF_DROP);
                        }
                        /* jumbo payload packets cannot be fragmented */
                        if (pd->jumbolen != 0) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 fragmented jumbo");
                                REASON_SET(reason, PFRES_FRAG);
                                return (PF_DROP);
                        }
                        if (!pf_pull_hdr(pd->m, pd->off, &frag, sizeof(frag),
                            reason, AF_INET6)) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 short fragment");
                                return (PF_DROP);
                        }
                        /* stop walking over non initial fragments */
                        if (ntohs((frag.ip6f_offlg & IP6F_OFF_MASK)) != 0) {
                                pd->fragoff = pd->off;
                                return (PF_PASS);
                        }
                        /* RFC6946:  reassemble only non atomic fragments */
                        if (frag.ip6f_offlg & IP6F_MORE_FRAG)
                                pd->fragoff = pd->off;
                        pd->off += sizeof(frag);
                        pd->proto = frag.ip6f_nxt;
                        break;
                case IPPROTO_ROUTING:
                        if (rthdr_cnt++) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 multiple rthdr");
                                REASON_SET(reason, PFRES_IPOPTIONS);
                                return (PF_DROP);
                        }
                        /* fragments may be short */
                        if (pd->fragoff != 0 && end < pd->off + sizeof(rthdr)) {
                                pd->off = pd->fragoff;
                                pd->proto = IPPROTO_FRAGMENT;
                                return (PF_PASS);
                        }
                        if (!pf_pull_hdr(pd->m, pd->off, &rthdr, sizeof(rthdr),
                            reason, AF_INET6)) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 short rthdr");
                                return (PF_DROP);
                        }
                        if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 rthdr0");
                                REASON_SET(reason, PFRES_IPOPTIONS);
                                return (PF_DROP);
                        }
                        /* FALLTHROUGH */
                case IPPROTO_HOPOPTS:
                        /* RFC2460 4.1:  Hop-by-Hop only after IPv6 header */
                        if (pd->proto == IPPROTO_HOPOPTS && hdr_cnt > 0) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 hopopts not first");
                                REASON_SET(reason, PFRES_IPOPTIONS);
                                return (PF_DROP);
                        }
                        /* FALLTHROUGH */
                case IPPROTO_AH:
                case IPPROTO_DSTOPTS:
                        /* fragments may be short */
                        if (pd->fragoff != 0 && end < pd->off + sizeof(ext)) {
                                pd->off = pd->fragoff;
                                pd->proto = IPPROTO_FRAGMENT;
                                return (PF_PASS);
                        }
                        if (!pf_pull_hdr(pd->m, pd->off, &ext, sizeof(ext),
                            reason, AF_INET6)) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 short exthdr");
                                return (PF_DROP);
                        }
                        /* reassembly needs the ext header before the frag */
                        if (pd->fragoff == 0)
                                pd->extoff = pd->off;
                        if (pd->proto == IPPROTO_HOPOPTS && pd->fragoff == 0 &&
                            ntohs(h->ip6_plen) == 0 && pd->jumbolen != 0) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 missing jumbo");
                                REASON_SET(reason, PFRES_IPOPTIONS);
                                return (PF_DROP);
                        }
                        if (pd->proto == IPPROTO_AH)
                                pd->off += (ext.ip6e_len + 2) * 4;
                        else
                                pd->off += (ext.ip6e_len + 1) * 8;
                        pd->proto = ext.ip6e_nxt;
                        break;
                case IPPROTO_ICMPV6:
                        /* fragments may be short, ignore inner header then */
                        if (pd->fragoff != 0 && end < pd->off + sizeof(icmp6)) {
                                pd->off = pd->fragoff;
                                pd->proto = IPPROTO_FRAGMENT;
                                return (PF_PASS);
                        }
                        if (!pf_pull_hdr(pd->m, pd->off, &icmp6, sizeof(icmp6),
                            reason, AF_INET6)) {
                                DPFPRINTF(LOG_NOTICE, "IPv6 short icmp6hdr");
                                return (PF_DROP);
                        }
                        /* ICMP multicast packets have router alert options */
                        switch (icmp6.icmp6_type) {
                        case MLD_LISTENER_QUERY:
                        case MLD_LISTENER_REPORT:
                        case MLD_LISTENER_DONE:
                        case MLDV2_LISTENER_REPORT:
                                /*
                                 * According to RFC 2710 all MLD messages are
                                 * sent with hop-limit (ttl) set to 1, and link
                                 * local source address.  If either one is
                                 * missing then MLD message is invalid and
                                 * should be discarded.
                                 */
                                if ((h->ip6_hlim != 1) ||
                                    !IN6_IS_ADDR_LINKLOCAL(&h->ip6_src)) {
                                        DPFPRINTF(LOG_NOTICE, "Invalid MLD");
                                        REASON_SET(reason, PFRES_IPOPTIONS);
                                        return (PF_DROP);
                                }
                                CLR(pd->badopts, PF_OPT_ROUTER_ALERT);
                                break;
                        }
                        return (PF_PASS);
                case IPPROTO_TCP:
                case IPPROTO_UDP:
                        /* fragments may be short, ignore inner header then */
                        if (pd->fragoff != 0 && end < pd->off +
                            (pd->proto == IPPROTO_TCP ? sizeof(struct tcphdr) :
                            pd->proto == IPPROTO_UDP ? sizeof(struct udphdr) :
                            sizeof(struct icmp6_hdr))) {
                                pd->off = pd->fragoff;
                                pd->proto = IPPROTO_FRAGMENT;
                        }
                        /* FALLTHROUGH */
                default:
                        return (PF_PASS);
                }
        }
        DPFPRINTF(LOG_NOTICE, "IPv6 nested extension header limit");
        REASON_SET(reason, PFRES_IPOPTIONS);
        return (PF_DROP);
}
#endif /* INET6 */

u_int16_t
pf_pkt_hash(sa_family_t af, uint8_t proto,
    const struct pf_addr *src, const struct pf_addr *dst,
    uint16_t sport, uint16_t dport)
{
        uint32_t hash;

        hash = src->addr32[0] ^ dst->addr32[0];
#ifdef INET6
        if (af == AF_INET6) {
                hash ^= src->addr32[1] ^ dst->addr32[1];
                hash ^= src->addr32[2] ^ dst->addr32[2];
                hash ^= src->addr32[3] ^ dst->addr32[3];
        }
#endif

        switch (proto) {
        case IPPROTO_TCP:
        case IPPROTO_UDP:
                hash ^= sport ^ dport;
                break;
        }

        return stoeplitz_n32(hash);
}

int
pf_setup_pdesc(struct pf_pdesc *pd, sa_family_t af, int dir,
    struct pfi_kif *kif, struct mbuf *m, u_short *reason)
{
        memset(pd, 0, sizeof(*pd));
        pd->dir = dir;
        pd->kif = kif;          /* kif is NULL when called by pflog */
        pd->m = m;
        pd->sidx = (dir == PF_IN) ? 0 : 1;
        pd->didx = (dir == PF_IN) ? 1 : 0;
        pd->af = pd->naf = af;
        pd->rdomain = rtable_l2(pd->m->m_pkthdr.ph_rtableid);

        switch (pd->af) {
        case AF_INET: {
                struct ip       *h;

                /* Check for illegal packets */
                if (pd->m->m_pkthdr.len < (int)sizeof(struct ip)) {
                        REASON_SET(reason, PFRES_SHORT);
                        return (PF_DROP);
                }

                h = mtod(pd->m, struct ip *);
                if (pd->m->m_pkthdr.len < ntohs(h->ip_len)) {
                        REASON_SET(reason, PFRES_SHORT);
                        return (PF_DROP);
                }

                if (pf_walk_header(pd, h, reason) != PF_PASS)
                        return (PF_DROP);

                pd->src = (struct pf_addr *)&h->ip_src;
                pd->dst = (struct pf_addr *)&h->ip_dst;
                pd->tot_len = ntohs(h->ip_len);
                pd->tos = h->ip_tos & ~IPTOS_ECN_MASK;
                pd->ttl = h->ip_ttl;
                pd->virtual_proto = (h->ip_off & htons(IP_MF | IP_OFFMASK)) ?
                     PF_VPROTO_FRAGMENT : pd->proto;

                break;
        }
#ifdef INET6
        case AF_INET6: {
                struct ip6_hdr  *h;

                /* Check for illegal packets */
                if (pd->m->m_pkthdr.len < (int)sizeof(struct ip6_hdr)) {
                        REASON_SET(reason, PFRES_SHORT);
                        return (PF_DROP);
                }

                h = mtod(pd->m, struct ip6_hdr *);
                if (pd->m->m_pkthdr.len <
                    sizeof(struct ip6_hdr) + ntohs(h->ip6_plen)) {
                        REASON_SET(reason, PFRES_SHORT);
                        return (PF_DROP);
                }

                if (pf_walk_header6(pd, h, reason) != PF_PASS)
                        return (PF_DROP);

#if 1
                /*
                 * we do not support jumbogram yet.  if we keep going, zero
                 * ip6_plen will do something bad, so drop the packet for now.
                 */
                if (pd->jumbolen != 0) {
                        REASON_SET(reason, PFRES_NORM);
                        return (PF_DROP);
                }
#endif  /* 1 */

                pd->src = (struct pf_addr *)&h->ip6_src;
                pd->dst = (struct pf_addr *)&h->ip6_dst;
                pd->tot_len = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr);
                pd->tos = (ntohl(h->ip6_flow) & 0x0fc00000) >> 20;
                pd->ttl = h->ip6_hlim;
                pd->virtual_proto = (pd->fragoff != 0) ?
                        PF_VPROTO_FRAGMENT : pd->proto;

                break;
        }
#endif /* INET6 */
        default:
                panic("pf_setup_pdesc called with illegal af %u", pd->af);

        }

        pf_addrcpy(&pd->nsaddr, pd->src, pd->af);
        pf_addrcpy(&pd->ndaddr, pd->dst, pd->af);

        switch (pd->virtual_proto) {
        case IPPROTO_TCP: {
                struct tcphdr   *th = &pd->hdr.tcp;

                if (!pf_pull_hdr(pd->m, pd->off, th, sizeof(*th),
                    reason, pd->af))
                        return (PF_DROP);
                pd->hdrlen = sizeof(*th);
                if (th->th_dport == 0 ||
                    pd->off + (th->th_off << 2) > pd->tot_len ||
                    (th->th_off << 2) < sizeof(struct tcphdr)) {
                        REASON_SET(reason, PFRES_SHORT);
                        return (PF_DROP);
                }
                pd->p_len = pd->tot_len - pd->off - (th->th_off << 2);
                pd->sport = &th->th_sport;
                pd->dport = &th->th_dport;
                pd->pcksum = &th->th_sum;
                break;
        }
        case IPPROTO_UDP: {
                struct udphdr   *uh = &pd->hdr.udp;

                if (!pf_pull_hdr(pd->m, pd->off, uh, sizeof(*uh),
                    reason, pd->af))
                        return (PF_DROP);
                pd->hdrlen = sizeof(*uh);
                if (uh->uh_dport == 0 ||
                    pd->off + ntohs(uh->uh_ulen) > pd->tot_len ||
                    ntohs(uh->uh_ulen) < sizeof(struct udphdr)) {
                        REASON_SET(reason, PFRES_SHORT);
                        return (PF_DROP);
                }
                pd->sport = &uh->uh_sport;
                pd->dport = &uh->uh_dport;
                pd->pcksum = &uh->uh_sum;
                break;
        }
        case IPPROTO_ICMP: {
                if (!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp, ICMP_MINLEN,
                    reason, pd->af))
                        return (PF_DROP);
                pd->hdrlen = ICMP_MINLEN;
                if (pd->off + pd->hdrlen > pd->tot_len) {
                        REASON_SET(reason, PFRES_SHORT);
                        return (PF_DROP);
                }
                pd->pcksum = &pd->hdr.icmp.icmp_cksum;
                break;
        }
#ifdef INET6
        case IPPROTO_ICMPV6: {
                size_t  icmp_hlen = sizeof(struct icmp6_hdr);

                if (!pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp6, icmp_hlen,
                    reason, pd->af))
                        return (PF_DROP);
                /* ICMP headers we look further into to match state */
                switch (pd->hdr.icmp6.icmp6_type) {
                case MLD_LISTENER_QUERY:
                case MLD_LISTENER_REPORT:
                        icmp_hlen = sizeof(struct mld_hdr);
                        break;
                case ND_NEIGHBOR_SOLICIT:
                case ND_NEIGHBOR_ADVERT:
                        icmp_hlen = sizeof(struct nd_neighbor_solicit);
                        /* FALLTHROUGH */
                case ND_ROUTER_SOLICIT:
                case ND_ROUTER_ADVERT:
                case ND_REDIRECT:
                        if (pd->ttl != 255) {
                                REASON_SET(reason, PFRES_NORM);
                                return (PF_DROP);
                        }
                        break;
                }
                if (icmp_hlen > sizeof(struct icmp6_hdr) &&
                    !pf_pull_hdr(pd->m, pd->off, &pd->hdr.icmp6, icmp_hlen,
                    reason, pd->af))
                        return (PF_DROP);
                pd->hdrlen = icmp_hlen;
                if (pd->off + pd->hdrlen > pd->tot_len) {
                        REASON_SET(reason, PFRES_SHORT);
                        return (PF_DROP);
                }
                pd->pcksum = &pd->hdr.icmp6.icmp6_cksum;
                break;
        }
#endif  /* INET6 */
        }

        if (pd->sport)
                pd->osport = pd->nsport = *pd->sport;
        if (pd->dport)
                pd->odport = pd->ndport = *pd->dport;

        pd->hash = pf_pkt_hash(pd->af, pd->proto,
            pd->src, pd->dst, pd->osport, pd->odport);

        return (PF_PASS);
}

void
pf_counters_inc(int action, struct pf_pdesc *pd, struct pf_state *st,
    struct pf_rule *r, struct pf_rule *a)
{
        int dirndx;
        pd->kif->pfik_bytes[pd->af == AF_INET6][pd->dir == PF_OUT]
            [action != PF_PASS] += pd->tot_len;
        pd->kif->pfik_packets[pd->af == AF_INET6][pd->dir == PF_OUT]
            [action != PF_PASS]++;

        if (action == PF_PASS || action == PF_AFRT || r->action == PF_DROP) {
                dirndx = (pd->dir == PF_OUT);
                r->packets[dirndx]++;
                r->bytes[dirndx] += pd->tot_len;
                if (a != NULL) {
                        a->packets[dirndx]++;
                        a->bytes[dirndx] += pd->tot_len;
                }
                if (st != NULL) {
                        struct pf_rule_item     *ri;
                        struct pf_sn_item       *sni;

                        SLIST_FOREACH(sni, &st->src_nodes, next) {
                                sni->sn->packets[dirndx]++;
                                sni->sn->bytes[dirndx] += pd->tot_len;
                        }
                        dirndx = (pd->dir == st->direction) ? 0 : 1;
                        st->packets[dirndx]++;
                        st->bytes[dirndx] += pd->tot_len;

                        SLIST_FOREACH(ri, &st->match_rules, entry) {
                                ri->r->packets[dirndx]++;
                                ri->r->bytes[dirndx] += pd->tot_len;

                                if (ri->r->src.addr.type == PF_ADDR_TABLE)
                                        pfr_update_stats(ri->r->src.addr.p.tbl,
                                            &st->key[(st->direction == PF_IN)]->
                                                addr[(st->direction == PF_OUT)],
                                            pd, ri->r->action, ri->r->src.neg);
                                if (ri->r->dst.addr.type == PF_ADDR_TABLE)
                                        pfr_update_stats(ri->r->dst.addr.p.tbl,
                                            &st->key[(st->direction == PF_IN)]->
                                                addr[(st->direction == PF_IN)],
                                            pd, ri->r->action, ri->r->dst.neg);
                        }
                }
                if (r->src.addr.type == PF_ADDR_TABLE)
                        pfr_update_stats(r->src.addr.p.tbl,
                            (st == NULL) ? pd->src :
                            &st->key[(st->direction == PF_IN)]->
                                addr[(st->direction == PF_OUT)],
                            pd, r->action, r->src.neg);
                if (r->dst.addr.type == PF_ADDR_TABLE)
                        pfr_update_stats(r->dst.addr.p.tbl,
                            (st == NULL) ? pd->dst :
                            &st->key[(st->direction == PF_IN)]->
                                addr[(st->direction == PF_IN)],
                            pd, r->action, r->dst.neg);
        }
}

int
pf_test(sa_family_t af, int fwdir, struct ifnet *ifp, struct mbuf **m0)
{
        struct pfi_kif          *kif = NULL;
        u_short                  action, reason = 0;
        struct pf_rule          *a = NULL, *r = &pf_default_rule;
        struct pf_state         *st = NULL;
        struct pf_state_key_cmp  key;
        struct pf_ruleset       *ruleset = NULL;
        struct pf_pdesc          pd;
        int                      dir = (fwdir == PF_FWD) ? PF_OUT : fwdir;
        u_int32_t                qid, pqid = 0;
        int                      have_pf_lock = 0;

        if (!pf_status.running)
                return (PF_PASS);

#if NCARP > 0
        if (ifp->if_type == IFT_CARP) {
                struct ifnet *ifp0;

                smr_read_enter();
                ifp0 = if_get_smr(ifp->if_carpdevidx);
                if (ifp0 != NULL)
                        kif = (struct pfi_kif *)ifp0->if_pf_kif;
                smr_read_leave();
        } else
#endif /* NCARP */
                kif = (struct pfi_kif *)ifp->if_pf_kif;

        if (kif == NULL) {
                DPFPRINTF(LOG_ERR,
                    "%s: kif == NULL, if_xname %s", __func__, ifp->if_xname);
                return (PF_DROP);
        }
        if (kif->pfik_flags & PFI_IFLAG_SKIP)
                return (PF_PASS);

#ifdef DIAGNOSTIC
        if (((*m0)->m_flags & M_PKTHDR) == 0)
                panic("non-M_PKTHDR is passed to pf_test");
#endif /* DIAGNOSTIC */

        if ((*m0)->m_pkthdr.pf.flags & PF_TAG_GENERATED)
                return (PF_PASS);

        if ((*m0)->m_pkthdr.pf.flags & PF_TAG_DIVERTED_PACKET) {
                (*m0)->m_pkthdr.pf.flags &= ~PF_TAG_DIVERTED_PACKET;
                return (PF_PASS);
        }

        if ((*m0)->m_pkthdr.pf.flags & PF_TAG_REFRAGMENTED) {
                (*m0)->m_pkthdr.pf.flags &= ~PF_TAG_REFRAGMENTED;
                return (PF_PASS);
        }

        action = pf_setup_pdesc(&pd, af, dir, kif, *m0, &reason);
        if (action != PF_PASS) {
#if NPFLOG > 0
                pd.pflog |= PF_LOG_FORCE;
#endif  /* NPFLOG > 0 */
                goto done;
        }

        /* packet normalization and reassembly */
        switch (pd.af) {
        case AF_INET:
                action = pf_normalize_ip(&pd, &reason);
                break;
#ifdef INET6
        case AF_INET6:
                action = pf_normalize_ip6(&pd, &reason);
                break;
#endif  /* INET6 */
        }
        *m0 = pd.m;
        /* if packet sits in reassembly queue, return without error */
        if (pd.m == NULL)
                return PF_PASS;

        if (action != PF_PASS) {
#if NPFLOG > 0
                pd.pflog |= PF_LOG_FORCE;
#endif  /* NPFLOG > 0 */
                goto done;
        }

        /* if packet has been reassembled, update packet description */
        if (pf_status.reass && pd.virtual_proto == PF_VPROTO_FRAGMENT) {
                action = pf_setup_pdesc(&pd, af, dir, kif, pd.m, &reason);
                if (action != PF_PASS) {
#if NPFLOG > 0
                        pd.pflog |= PF_LOG_FORCE;
#endif  /* NPFLOG > 0 */
                        goto done;
                }
        }
        pd.m->m_pkthdr.pf.flags |= PF_TAG_PROCESSED;

        /*
         * Avoid pcb-lookups from the forwarding path.  They should never
         * match and would cause MP locking problems.
         */
        if (fwdir == PF_FWD) {
                pd.lookup.done = -1;
                pd.lookup.uid = -1;
                pd.lookup.gid = -1;
                pd.lookup.pid = NO_PID;
        }

        switch (pd.virtual_proto) {

        case PF_VPROTO_FRAGMENT: {
                /*
                 * handle fragments that aren't reassembled by
                 * normalization
                 */
                PF_LOCK();
                have_pf_lock = 1;
                action = pf_test_rule(&pd, &r, &st, &a, &ruleset, &reason);
                st = pf_state_ref(st);
                if (action != PF_PASS)
                        REASON_SET(&reason, PFRES_FRAG);
                break;
        }

        case IPPROTO_ICMP: {
                if (pd.af != AF_INET) {
                        action = PF_DROP;
                        REASON_SET(&reason, PFRES_NORM);
                        DPFPRINTF(LOG_NOTICE,
                            "dropping IPv6 packet with ICMPv4 payload");
                        break;
                }
                PF_STATE_ENTER_READ();
                action = pf_test_state_icmp(&pd, &st, &reason);
                st = pf_state_ref(st);
                PF_STATE_EXIT_READ();
                if (action == PF_PASS || action == PF_AFRT) {
#if NPFSYNC > 0
                        pfsync_update_state(st);
#endif /* NPFSYNC > 0 */
                        r = st->rule.ptr;
                        a = st->anchor.ptr;
#if NPFLOG > 0
                        pd.pflog |= st->log;
#endif  /* NPFLOG > 0 */
                } else if (st == NULL) {
                        PF_LOCK();
                        have_pf_lock = 1;
                        action = pf_test_rule(&pd, &r, &st, &a, &ruleset,
                            &reason);
                        st = pf_state_ref(st);
                }
                break;
        }

#ifdef INET6
        case IPPROTO_ICMPV6: {
                if (pd.af != AF_INET6) {
                        action = PF_DROP;
                        REASON_SET(&reason, PFRES_NORM);
                        DPFPRINTF(LOG_NOTICE,
                            "dropping IPv4 packet with ICMPv6 payload");
                        break;
                }
                PF_STATE_ENTER_READ();
                action = pf_test_state_icmp(&pd, &st, &reason);
                st = pf_state_ref(st);
                PF_STATE_EXIT_READ();
                if (action == PF_PASS || action == PF_AFRT) {
#if NPFSYNC > 0
                        pfsync_update_state(st);
#endif /* NPFSYNC > 0 */
                        r = st->rule.ptr;
                        a = st->anchor.ptr;
#if NPFLOG > 0
                        pd.pflog |= st->log;
#endif  /* NPFLOG > 0 */
                } else if (st == NULL) {
                        PF_LOCK();
                        have_pf_lock = 1;
                        action = pf_test_rule(&pd, &r, &st, &a, &ruleset,
                            &reason);
                        st = pf_state_ref(st);
                }
                break;
        }
#endif /* INET6 */

        case IPPROTO_TCP:
                if (pd.dir == PF_IN &&
                    (pd.hdr.tcp.th_flags & (TH_SYN|TH_ACK)) == TH_SYN &&
                    pf_synflood_check(&pd)) {
                        PF_LOCK();
                        have_pf_lock = 1;
                        pf_syncookie_send(&pd, &reason);
                        action = PF_DROP;
                        break;
                }
                if ((pd.hdr.tcp.th_flags & TH_ACK) && pd.p_len == 0)
                        pqid = 1;
                action = pf_normalize_tcp(&pd);
                if (action == PF_DROP)
                        break;

                /* FALLTHROUGH */
        default:
                key.af = pd.af;
                key.proto = pd.virtual_proto;
                key.rdomain = pd.rdomain;
                pf_addrcpy(&key.addr[pd.sidx], pd.src, key.af);
                pf_addrcpy(&key.addr[pd.didx], pd.dst, key.af);
                key.port[pd.sidx] = pd.osport;
                key.port[pd.didx] = pd.odport;
                key.hash = pd.hash;

                PF_STATE_ENTER_READ();
                action = pf_find_state(&pd, &key, &st);
                st = pf_state_ref(st);
                PF_STATE_EXIT_READ();

                /* check for syncookies if tcp ack and no active state */
                if (pd.dir == PF_IN && pd.virtual_proto == IPPROTO_TCP &&
                    (st == NULL || (st->src.state >= TCPS_FIN_WAIT_2 &&
                    st->dst.state >= TCPS_FIN_WAIT_2)) &&
                    (pd.hdr.tcp.th_flags & (TH_SYN|TH_ACK|TH_RST)) == TH_ACK &&
                    pf_syncookie_validate(&pd)) {
                        struct mbuf     *msyn;
                        msyn = pf_syncookie_recreate_syn(&pd, &reason);
                        if (msyn) {
                                action = pf_test(af, fwdir, ifp, &msyn);
                                m_freem(msyn);
                                if (action == PF_PASS || action == PF_AFRT) {
                                        PF_STATE_ENTER_READ();
                                        pf_state_unref(st);
                                        action = pf_find_state(&pd, &key, &st);
                                        st = pf_state_ref(st);
                                        PF_STATE_EXIT_READ();
                                        if (st == NULL)
                                                return (PF_DROP);
                                        st->src.seqhi = st->dst.seqhi =
                                            ntohl(pd.hdr.tcp.th_ack) - 1;
                                        st->src.seqlo =
                                            ntohl(pd.hdr.tcp.th_seq) - 1;
                                        pf_set_protostate(st, PF_PEER_SRC,
                                            PF_TCPS_PROXY_DST);
                                }
                        } else
                                action = PF_DROP;
                }

                if (action == PF_MATCH)
                        action = pf_test_state(&pd, &st, &reason);

                if (action == PF_PASS || action == PF_AFRT) {
#if NPFSYNC > 0
                        pfsync_update_state(st);
#endif /* NPFSYNC > 0 */
                        r = st->rule.ptr;
                        a = st->anchor.ptr;
#if NPFLOG > 0
                        pd.pflog |= st->log;
#endif  /* NPFLOG > 0 */
                } else if (st == NULL) {
                        PF_LOCK();
                        have_pf_lock = 1;
                        action = pf_test_rule(&pd, &r, &st, &a, &ruleset,
                            &reason);
                        st = pf_state_ref(st);
                }

                if (pd.virtual_proto == IPPROTO_TCP) {
                        if (st) {
                                if (st->max_mss)
                                        pf_normalize_mss(&pd, st->max_mss);
                        } else if (r->max_mss)
                                pf_normalize_mss(&pd, r->max_mss);
                }

                break;
        }

        if (have_pf_lock != 0)
                PF_UNLOCK();

        /*
         * At the moment, we rely on NET_LOCK() to prevent removal of items
         * we've collected above ('r', 'anchor' and 'ruleset').  They'll have
         * to be refcounted when NET_LOCK() is gone.
         */

done:
        if (action != PF_DROP) {
                if (st) {
                        /* The non-state case is handled in pf_test_rule() */
                        if (action == PF_PASS && pd.badopts != 0 &&
                            !(st->state_flags & PFSTATE_ALLOWOPTS)) {
                                action = PF_DROP;
                                REASON_SET(&reason, PFRES_IPOPTIONS);
#if NPFLOG > 0
                                pd.pflog |= PF_LOG_FORCE;
#endif  /* NPFLOG > 0 */
                                DPFPRINTF(LOG_NOTICE, "dropping packet with "
                                    "ip/ipv6 options in pf_test()");
                        }

                        pf_scrub(pd.m, st->state_flags, pd.af, st->min_ttl,
                            st->set_tos);
                        pf_tag_packet(pd.m, st->tag, st->rtableid[pd.didx]);
                        if (pqid || (pd.tos & IPTOS_LOWDELAY)) {
                                qid = st->pqid;
                                if (st->state_flags & PFSTATE_SETPRIO) {
                                        pd.m->m_pkthdr.pf.prio =
                                            st->set_prio[1];
                                }
                        } else {
                                qid = st->qid;
                                if (st->state_flags & PFSTATE_SETPRIO) {
                                        pd.m->m_pkthdr.pf.prio =
                                            st->set_prio[0];
                                }
                        }
                        pd.m->m_pkthdr.pf.delay = st->delay;
                } else {
                        pf_scrub(pd.m, r->scrub_flags, pd.af, r->min_ttl,
                            r->set_tos);
                        if (pqid || (pd.tos & IPTOS_LOWDELAY)) {
                                qid = r->pqid;
                                if (r->scrub_flags & PFSTATE_SETPRIO)
                                        pd.m->m_pkthdr.pf.prio = r->set_prio[1];
                        } else {
                                qid = r->qid;
                                if (r->scrub_flags & PFSTATE_SETPRIO)
                                        pd.m->m_pkthdr.pf.prio = r->set_prio[0];
                        }
                        pd.m->m_pkthdr.pf.delay = r->delay;
                }
        }

        if (action == PF_PASS && qid)
                pd.m->m_pkthdr.pf.qid = qid;
        if (st != NULL) {
                struct mbuf *m = pd.m;
                struct inpcb *inp = m->m_pkthdr.pf.inp;

                if (pd.dir == PF_IN) {
                        KASSERT(inp == NULL);
                        pf_mbuf_link_state_key(m, st->key[PF_SK_STACK]);
                } else if (pd.dir == PF_OUT)
                        pf_state_key_link_inpcb(st->key[PF_SK_STACK], inp);

                if (!ISSET(m->m_pkthdr.csum_flags, M_FLOWID)) {
                        m->m_pkthdr.ph_flowid = st->key[PF_SK_WIRE]->hash;
                        SET(m->m_pkthdr.csum_flags, M_FLOWID);
                }
        }

        /*
         * connections redirected to loopback should not match sockets
         * bound specifically to loopback due to security implications,
         * see in_pcblookup_listen().
         */
        if (pd.destchg)
                if ((pd.af == AF_INET && (ntohl(pd.dst->v4.s_addr) >>
                    IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) ||
                    (pd.af == AF_INET6 && IN6_IS_ADDR_LOOPBACK(&pd.dst->v6)))
                        pd.m->m_pkthdr.pf.flags |= PF_TAG_TRANSLATE_LOCALHOST;
        /* We need to redo the route lookup on outgoing routes. */
        if (pd.destchg && pd.dir == PF_OUT)
                pd.m->m_pkthdr.pf.flags |= PF_TAG_REROUTE;

        if (pd.dir == PF_IN && action == PF_PASS &&
            (r->divert.type == PF_DIVERT_TO ||
            r->divert.type == PF_DIVERT_REPLY)) {
                struct pf_divert *divert;

                if ((divert = pf_get_divert(pd.m))) {
                        pd.m->m_pkthdr.pf.flags |= PF_TAG_DIVERTED;
                        divert->addr = r->divert.addr;
                        divert->port = r->divert.port;
                        divert->rdomain = pd.rdomain;
                        divert->type = r->divert.type;
                }
        }

        if (action == PF_PASS && r->divert.type == PF_DIVERT_PACKET)
                action = PF_DIVERT;

#if NPFLOG > 0
        if (pd.pflog) {
                struct pf_rule_item     *ri;

                if (pd.pflog & PF_LOG_FORCE || r->log & PF_LOG_ALL)
                        pflog_packet(&pd, reason, r, a, ruleset, NULL);
                if (st) {
                        SLIST_FOREACH(ri, &st->match_rules, entry)
                                if (ri->r->log & PF_LOG_ALL)
                                        pflog_packet(&pd, reason, ri->r, a,
                                            ruleset, NULL);
                }
        }
#endif  /* NPFLOG > 0 */

        pf_counters_inc(action, &pd, st, r, a);

        switch (action) {
        case PF_SYNPROXY_DROP:
                m_freem(pd.m);
                /* FALLTHROUGH */
        case PF_DEFER:
                pd.m = NULL;
                action = PF_PASS;
                break;
        case PF_DIVERT:
                switch (pd.af) {
                case AF_INET:
                        divert_packet(pd.m, pd.dir, r->divert.port);
                        pd.m = NULL;
                        break;
#ifdef INET6
                case AF_INET6:
                        divert6_packet(pd.m, pd.dir, r->divert.port);
                        pd.m = NULL;
                        break;
#endif /* INET6 */
                }
                action = PF_PASS;
                break;
#ifdef INET6
        case PF_AFRT:
                if (pf_translate_af(&pd)) {
                        action = PF_DROP;
                        goto out;
                }
                pd.m->m_pkthdr.pf.flags |= PF_TAG_GENERATED;
                switch (pd.naf) {
                case AF_INET:
                        if (pd.dir == PF_IN) {
                                int flags = IP_REDIRECT;

                                switch (atomic_load_int(&ip_forwarding)) {
                                case 2:
                                        SET(flags, IP_FORWARDING_IPSEC);
                                        /* FALLTHROUGH */
                                case 1:
                                        SET(flags, IP_FORWARDING);
                                        break;
                                default:
                                        ipstat_inc(ips_cantforward);
                                        action = PF_DROP;
                                        goto out;
                                }
                                if (atomic_load_int(&ip_directedbcast))
                                        SET(flags, IP_ALLOWBROADCAST);
                                ip_forward(pd.m, ifp, NULL, flags);
                        } else
                                ip_output(pd.m, NULL, NULL, 0, NULL, NULL, 0);
                        break;
                case AF_INET6:
                        if (pd.dir == PF_IN) {
                                int flags = IPV6_REDIRECT;

                                switch (atomic_load_int(&ip6_forwarding)) {
                                case 2:
                                        SET(flags, IPV6_FORWARDING_IPSEC);
                                        /* FALLTHROUGH */
                                case 1:
                                        SET(flags, IPV6_FORWARDING);
                                        break;
                                default:
                                        ip6stat_inc(ip6s_cantforward);
                                        action = PF_DROP;
                                        goto out;
                                }
                                ip6_forward(pd.m, NULL, flags);
                        } else
                                ip6_output(pd.m, NULL, NULL, 0, NULL, NULL);
                        break;
                }
                pd.m = NULL;
                action = PF_PASS;
                break;
#endif /* INET6 */
        case PF_DROP:
                m_freem(pd.m);
                pd.m = NULL;
                break;
        default:
                if (st && st->rt) {
                        switch (pd.af) {
                        case AF_INET:
                                pf_route(&pd, st);
                                break;
#ifdef INET6
                        case AF_INET6:
                                pf_route6(&pd, st);
                                break;
#endif /* INET6 */
                        }
                }
                break;
        }

#ifdef INET6
        /* if reassembled packet passed, create new fragments */
        if (pf_status.reass && action == PF_PASS && pd.m && fwdir == PF_FWD &&
            pd.af == AF_INET6) {
                struct m_tag    *mtag;

                if ((mtag = m_tag_find(pd.m, PACKET_TAG_PF_REASSEMBLED, NULL)))
                        action = pf_refragment6(&pd.m, mtag, NULL, NULL, NULL);
        }
#endif  /* INET6 */
        if (st && action != PF_DROP) {
                if (!st->if_index_in && dir == PF_IN)
                        st->if_index_in = ifp->if_index;
                else if (!st->if_index_out && dir == PF_OUT)
                        st->if_index_out = ifp->if_index;
        }

#ifdef INET6
out:
#endif /* INET6 */
        *m0 = pd.m;

        pf_state_unref(st);

        return (action);
}

int
pf_ouraddr(struct mbuf *m)
{
        struct pf_state_key     *sk;

        if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED)
                return (1);

        sk = m->m_pkthdr.pf.statekey;
        if (sk != NULL) {
                if (READ_ONCE(sk->sk_inp) != NULL)
                        return (1);
        }

        return (-1);
}

/*
 * must be called whenever any addressing information such as
 * address, port, protocol has changed
 */
void
pf_pkt_addr_changed(struct mbuf *m)
{
        pf_mbuf_unlink_state_key(m);
        pf_mbuf_unlink_inpcb(m);
}

struct inpcb *
pf_inp_lookup(struct mbuf *m)
{
        struct inpcb *inp = NULL;
        struct pf_state_key *sk = m->m_pkthdr.pf.statekey;

        if (!pf_state_key_isvalid(sk))
                pf_mbuf_unlink_state_key(m);
        else if (READ_ONCE(sk->sk_inp) != NULL) {
                mtx_enter(&pf_inp_mtx);
                inp = in_pcbref(sk->sk_inp);
                mtx_leave(&pf_inp_mtx);
        }

        return (inp);
}

void
pf_inp_link(struct mbuf *m, struct inpcb *inp)
{
        struct pf_state_key *sk = m->m_pkthdr.pf.statekey;

        if (!pf_state_key_isvalid(sk)) {
                pf_mbuf_unlink_state_key(m);
                return;
        }

        /*
         * we don't need to grab PF-lock here. At worst case we link inp to
         * state, which might be just being marked as deleted by another
         * thread.
         */
        pf_state_key_link_inpcb(sk, inp);

        /* The statekey has finished finding the inp, it is no longer needed. */
        pf_mbuf_unlink_state_key(m);
}

void
pf_inp_unlink(struct inpcb *inp)
{
        struct pf_state_key *sk;

        if (READ_ONCE(inp->inp_pf_sk) == NULL)
                return;

        mtx_enter(&pf_inp_mtx);
        sk = inp->inp_pf_sk;
        if (sk == NULL) {
                mtx_leave(&pf_inp_mtx);
                return;
        }
        KASSERT(sk->sk_inp == inp);
        sk->sk_inp = NULL;
        inp->inp_pf_sk = NULL;
        mtx_leave(&pf_inp_mtx);

        pf_state_key_unref(sk);
        in_pcbunref(inp);
}

void
pf_state_key_link_reverse(struct pf_state_key *sk, struct pf_state_key *skrev)
{
        struct pf_state_key *old_reverse;

        old_reverse = atomic_cas_ptr(&sk->sk_reverse, NULL, skrev);
        if (old_reverse != NULL)
                KASSERT(old_reverse == skrev);
        else {
                pf_state_key_ref(skrev);

                /*
                 * NOTE: if sk == skrev, then KASSERT() below holds true, we
                 * still want to grab a reference in such case, because
                 * pf_state_key_unlink_reverse() does not check whether keys
                 * are identical or not.
                 */
                old_reverse = atomic_cas_ptr(&skrev->sk_reverse, NULL, sk);
                if (old_reverse != NULL)
                        KASSERT(old_reverse == sk);

                pf_state_key_ref(sk);
        }
}

#if NPFLOG > 0
void
pf_log_matches(struct pf_pdesc *pd, struct pf_rule *rm, struct pf_rule *am,
    struct pf_ruleset *ruleset, struct pf_rule_slist *matchrules)
{
        struct pf_rule_item     *ri;

        /* if this is the log(matches) rule, packet has been logged already */
        if (rm->log & PF_LOG_MATCHES)
                return;

        SLIST_FOREACH(ri, matchrules, entry)
                if (ri->r->log & PF_LOG_MATCHES)
                        pflog_packet(pd, PFRES_MATCH, rm, am, ruleset, ri->r);
}
#endif  /* NPFLOG > 0 */

struct pf_state_key *
pf_state_key_ref(struct pf_state_key *sk)
{
        if (sk != NULL)
                PF_REF_TAKE(sk->sk_refcnt);

        return (sk);
}

void
pf_state_key_unref(struct pf_state_key *sk)
{
        if (PF_REF_RELE(sk->sk_refcnt)) {
                /* state key must be removed from tree */
                KASSERT(!pf_state_key_isvalid(sk));
                /* state key must be unlinked from reverse key */
                KASSERT(sk->sk_reverse == NULL);
                /* state key must be unlinked from socket */
                KASSERT(sk->sk_inp == NULL);
                pool_put(&pf_state_key_pl, sk);
        }
}

int
pf_state_key_isvalid(struct pf_state_key *sk)
{
        return ((sk != NULL) && (sk->sk_removed == 0));
}

void
pf_mbuf_link_state_key(struct mbuf *m, struct pf_state_key *sk)
{
        KASSERT(m->m_pkthdr.pf.statekey == NULL);
        m->m_pkthdr.pf.statekey = pf_state_key_ref(sk);
}

void
pf_mbuf_unlink_state_key(struct mbuf *m)
{
        struct pf_state_key *sk = m->m_pkthdr.pf.statekey;

        if (sk != NULL) {
                m->m_pkthdr.pf.statekey = NULL;
                pf_state_key_unref(sk);
        }
}

void
pf_mbuf_link_inpcb(struct mbuf *m, struct inpcb *inp)
{
        KASSERT(m->m_pkthdr.pf.inp == NULL);
        m->m_pkthdr.pf.inp = in_pcbref(inp);
}

void
pf_mbuf_unlink_inpcb(struct mbuf *m)
{
        struct inpcb *inp = m->m_pkthdr.pf.inp;

        if (inp != NULL) {
                m->m_pkthdr.pf.inp = NULL;
                in_pcbunref(inp);
        }
}

void
pf_state_key_link_inpcb(struct pf_state_key *sk, struct inpcb *inp)
{
        if (inp == NULL || READ_ONCE(sk->sk_inp) != NULL)
                return;

        mtx_enter(&pf_inp_mtx);
        if (inp->inp_pf_sk != NULL || sk->sk_inp != NULL) {
                mtx_leave(&pf_inp_mtx);
                return;
        }
        sk->sk_inp = in_pcbref(inp);
        inp->inp_pf_sk = pf_state_key_ref(sk);
        mtx_leave(&pf_inp_mtx);
}

void
pf_state_key_unlink_inpcb(struct pf_state_key *sk)
{
        struct inpcb *inp;

        if (READ_ONCE(sk->sk_inp) == NULL)
                return;

        mtx_enter(&pf_inp_mtx);
        inp = sk->sk_inp;
        if (inp == NULL) {
                mtx_leave(&pf_inp_mtx);
                return;
        }
        KASSERT(inp->inp_pf_sk == sk);
        sk->sk_inp = NULL;
        inp->inp_pf_sk = NULL;
        mtx_leave(&pf_inp_mtx);

        pf_state_key_unref(sk);
        in_pcbunref(inp);
}

void
pf_state_key_unlink_reverse(struct pf_state_key *sk)
{
        struct pf_state_key *skrev = sk->sk_reverse;

        /* Note that sk and skrev may be equal, then we unref twice. */
        if (skrev != NULL) {
                KASSERT(skrev->sk_reverse == sk);
                sk->sk_reverse = NULL;
                skrev->sk_reverse = NULL;
                pf_state_key_unref(skrev);
                pf_state_key_unref(sk);
        }
}

struct pf_state *
pf_state_ref(struct pf_state *st)
{
        if (st != NULL)
                PF_REF_TAKE(st->refcnt);
        return (st);
}

void
pf_state_unref(struct pf_state *st)
{
        if ((st != NULL) && PF_REF_RELE(st->refcnt)) {
                /* never inserted or removed */
#if NPFSYNC > 0
                KASSERT((TAILQ_NEXT(st, sync_list) == NULL) ||
                    ((TAILQ_NEXT(st, sync_list) == _Q_INVALID) &&
                    (st->sync_state >= PFSYNC_S_NONE)));
#endif  /* NPFSYNC */
                KASSERT((TAILQ_NEXT(st, entry_list) == NULL) ||
                    (TAILQ_NEXT(st, entry_list) == _Q_INVALID));

                pf_state_key_unref(st->key[PF_SK_WIRE]);
                pf_state_key_unref(st->key[PF_SK_STACK]);

                KASSERT(SLIST_EMPTY(&st->linkage));

                pool_put(&pf_state_pl, st);
        }
}

int
pf_delay_pkt(struct mbuf *m, u_int ifidx)
{
        struct pf_pktdelay      *pdy;

        if ((pdy = pool_get(&pf_pktdelay_pl, PR_NOWAIT)) == NULL) {
                m_freem(m);
                return (ENOBUFS);
        }
        pdy->ifidx = ifidx;
        pdy->m = m;
        timeout_set(&pdy->to, pf_pktenqueue_delayed, pdy);
        timeout_add_msec(&pdy->to, m->m_pkthdr.pf.delay);
        m->m_pkthdr.pf.delay = 0;
        return (0);
}

void
pf_pktenqueue_delayed(void *arg)
{
        struct pf_pktdelay      *pdy = arg;
        struct ifnet            *ifp;

        ifp = if_get(pdy->ifidx);
        if (ifp != NULL) {
                if_enqueue(ifp, pdy->m);
                if_put(ifp);
        } else
                m_freem(pdy->m);

        pool_put(&pf_pktdelay_pl, pdy);
}

void
pf_status_init(void)
{
        memset(&pf_status, 0, sizeof(pf_status));
        pf_status.debug = LOG_ERR;
        pf_status.reass = PF_REASS_ENABLED;

        /* XXX do our best to avoid a conflict */
        pf_status.hostid = arc4random();

        pf_status_fcounters = counters_alloc(FCNT_MAX);
}

void
pf_status_clear(void)
{
        PF_ASSERT_LOCKED();
        counters_zero(pf_status_fcounters, FCNT_MAX);
}

void
pf_status_read(struct pf_status *pfs)
{
        uint64_t scratch[FCNT_MAX];

        NET_LOCK();
        PF_LOCK();
        PF_FRAG_LOCK();
        memcpy(pfs, &pf_status, sizeof(struct pf_status));
        PF_FRAG_UNLOCK();
        pfi_update_status(pfs->ifname, pfs);
        PF_UNLOCK();
        NET_UNLOCK();

        counters_read(pf_status_fcounters, pfs->fcounters, FCNT_MAX, scratch);
}