/*      $NetBSD: if_pfsync.c,v 1.24 2026/01/11 16:41:43 christos Exp $  */
/*      $OpenBSD: if_pfsync.c,v 1.83 2007/06/26 14:44:12 mcbride Exp $  */

/*
 * Copyright (c) 2002 Michael Shalayeff
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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 AUTHOR ``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 AUTHOR OR HIS RELATIVES 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 MIND, 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_pfsync.c,v 1.24 2026/01/11 16:41:43 christos Exp $");

#ifdef _KERNEL_OPT
#include "opt_inet.h"
#include "opt_inet6.h"
#endif

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/callout.h>
#include <sys/kernel.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/bpf.h>
#include <netinet/in.h>
#ifndef __NetBSD__
#include <netinet/if_ether.h>
#else
#include <net/if_ether.h>
#endif /* __NetBSD__ */
#include <netinet/tcp.h>
#include <netinet/tcp_seq.h>

#ifdef  INET
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#endif

#ifdef INET6
#include <netinet6/nd6.h>
#endif /* INET6 */

#include "carp.h"
#if NCARP > 0
extern int carp_suppress_preempt;
#endif

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

#ifdef __NetBSD__
#include <sys/conf.h>
#include <sys/lwp.h>
#include <sys/kauth.h>
#include <sys/sysctl.h>

#include <net/net_stats.h>

#include "ioconf.h"

percpu_t        *pfsyncstat_percpu;

#define PFSYNC_STATINC(x) _NET_STATINC(pfsyncstat_percpu, x)
#endif /* __NetBSD__ */

#include "pfsync.h"

#define PFSYNC_MINMTU   \
    (sizeof(struct pfsync_header) + sizeof(struct pf_state))

#ifdef PFSYNCDEBUG
#define DPRINTF(x)    do { if (pfsyncdebug) printf x ; } while (0)
int pfsyncdebug;
#else
#define DPRINTF(x)
#endif

extern int ifqmaxlen; /* XXX */

struct pfsync_softc     *pfsyncif = NULL;

int     pfsync_clone_create(struct if_clone *, int);
int     pfsync_clone_destroy(struct ifnet *);
void    pfsync_setmtu(struct pfsync_softc *, int);
int     pfsync_alloc_scrub_memory(struct pfsync_state_peer *,
            struct pf_state_peer *);
int     pfsync_insert_net_state(struct pfsync_state *, u_int8_t);
void    pfsync_update_net_tdb(struct pfsync_tdb *);
int     pfsyncoutput(struct ifnet *, struct mbuf *, const struct sockaddr *,
            const struct rtentry *);
int     pfsyncioctl(struct ifnet *, u_long, void*);
void    pfsyncstart(struct ifnet *);

struct mbuf *pfsync_get_mbuf(struct pfsync_softc *, u_int8_t, void **);
int     pfsync_request_update(struct pfsync_state_upd *, struct in_addr *);
int     pfsync_sendout(struct pfsync_softc *);
int     pfsync_tdb_sendout(struct pfsync_softc *);
int     pfsync_sendout_mbuf(struct pfsync_softc *, struct mbuf *);
void    pfsync_timeout(void *);
void    pfsync_tdb_timeout(void *);
void    pfsync_send_bus(struct pfsync_softc *, u_int8_t);
void    pfsync_bulk_update(void *);
void    pfsync_bulkfail(void *);

int     pfsync_sync_ok;

struct if_clone pfsync_cloner =
    IF_CLONE_INITIALIZER("pfsync", pfsync_clone_create, pfsync_clone_destroy);

void
pfsyncattach(int npfsync)
{
        if_clone_attach(&pfsync_cloner);

        pfsyncstat_percpu = percpu_alloc(sizeof(uint64_t) * PFSYNC_NSTATS);
}

int
pfsync_clone_create(struct if_clone *ifc, int unit)
{
        struct ifnet *ifp;

        if (unit != 0)
                return (EINVAL);

        pfsync_sync_ok = 1;
        if ((pfsyncif = malloc(sizeof(*pfsyncif), M_DEVBUF, M_NOWAIT)) == NULL)
                return (ENOMEM);
        memset(pfsyncif, 0, sizeof(*pfsyncif));
        pfsyncif->sc_mbuf = NULL;
        pfsyncif->sc_mbuf_net = NULL;
        pfsyncif->sc_mbuf_tdb = NULL;
        pfsyncif->sc_statep.s = NULL;
        pfsyncif->sc_statep_net.s = NULL;
        pfsyncif->sc_statep_tdb.t = NULL;
        pfsyncif->sc_maxupdates = 128;
        pfsyncif->sc_sync_peer.s_addr = INADDR_PFSYNC_GROUP;
        pfsyncif->sc_sendaddr.s_addr = INADDR_PFSYNC_GROUP;
        pfsyncif->sc_ureq_received = 0;
        pfsyncif->sc_ureq_sent = 0;
        pfsyncif->sc_bulk_send_next = NULL;
        pfsyncif->sc_bulk_terminator = NULL;
        ifp = &pfsyncif->sc_if;
        snprintf(ifp->if_xname, sizeof ifp->if_xname, "pfsync%d", unit);
        ifp->if_softc = pfsyncif;
        ifp->if_ioctl = pfsyncioctl;
        ifp->if_output = pfsyncoutput;
        ifp->if_start = pfsyncstart;
        ifp->if_type = IFT_PFSYNC;
        ifp->if_snd.ifq_maxlen = ifqmaxlen;
        ifp->if_hdrlen = PFSYNC_HDRLEN;
        pfsync_setmtu(pfsyncif, ETHERMTU);

        callout_init(&pfsyncif->sc_tmo, 0);
        callout_init(&pfsyncif->sc_tdb_tmo, 0);
        callout_init(&pfsyncif->sc_bulk_tmo, 0);
        callout_init(&pfsyncif->sc_bulkfail_tmo, 0);
        callout_setfunc(&pfsyncif->sc_tmo, pfsync_timeout, pfsyncif);
        callout_setfunc(&pfsyncif->sc_tdb_tmo, pfsync_tdb_timeout, pfsyncif);
        callout_setfunc(&pfsyncif->sc_bulk_tmo, pfsync_bulk_update, pfsyncif);
        callout_setfunc(&pfsyncif->sc_bulkfail_tmo, pfsync_bulkfail, pfsyncif);

        if_attach(ifp);
        if_alloc_sadl(ifp);

        bpf_attach(&pfsyncif->sc_if, DLT_PFSYNC, PFSYNC_HDRLEN);

        return (0);
}

int
pfsync_clone_destroy(struct ifnet *ifp)
{
        bpf_detach(ifp);
        if_detach(ifp);
        free(pfsyncif, M_DEVBUF);
        pfsyncif = NULL;
        return (0);
}

/*
 * Start output on the pfsync interface.
 */
void
pfsyncstart(struct ifnet *ifp)
{
        struct mbuf *m;
        int s;

        for (;;) {
                s = splnet();
                IF_DROP(&ifp->if_snd);
                IF_DEQUEUE(&ifp->if_snd, m);
                splx(s);

                if (m == NULL)
                        return;
                else
                        m_freem(m);
        }
}

int
pfsync_alloc_scrub_memory(struct pfsync_state_peer *s,
    struct pf_state_peer *d)
{
        if (s->scrub.scrub_flag && d->scrub == NULL) {
                d->scrub = pool_get(&pf_state_scrub_pl, PR_NOWAIT);
                if (d->scrub == NULL)
                        return (ENOMEM);
                memset(d->scrub, 0, sizeof(*d->scrub));
        }

        return (0);
}

int
pfsync_insert_net_state(struct pfsync_state *sp, u_int8_t chksum_flag)
{
        struct pf_state *st = NULL;
        struct pf_state_key *sk = NULL;
        struct pf_rule *r = NULL;
        struct pfi_kif  *kif;

        if (strnlen(sp->ifname, IFNAMSIZ) == IFNAMSIZ)
                return (EINVAL);

        if (sp->creatorid == 0 && pf_status.debug >= PF_DEBUG_MISC) {
                printf("pfsync_insert_net_state: invalid creator id:"
                    " %08x\n", ntohl(sp->creatorid));
                return (EINVAL);
        }

        kif = pfi_kif_get(sp->ifname);
        if (kif == NULL) {
                if (pf_status.debug >= PF_DEBUG_MISC)
                        printf("pfsync_insert_net_state: "
                            "unknown interface: %s\n", sp->ifname);
                /* skip this state */
                return (0);
        }

        /*
         * If the ruleset checksums match, it's safe to associate the state
         * with the rule of that number.
         */
        if (sp->rule != htonl(-1) && sp->anchor == htonl(-1) && chksum_flag &&
            ntohl(sp->rule) <
            pf_main_ruleset.rules[PF_RULESET_FILTER].active.rcount)
                r = pf_main_ruleset.rules[
                    PF_RULESET_FILTER].active.ptr_array[ntohl(sp->rule)];
        else
                r = &pf_default_rule;

        if (!r->max_states || r->states < r->max_states)
                st = pool_get(&pf_state_pl, PR_NOWAIT);
        if (st == NULL) {
                pfi_kif_unref(kif, PFI_KIF_REF_NONE);
                return (ENOMEM);
        }
        memset(st, 0, sizeof(*st));

        if ((sk = pf_alloc_state_key(st)) == NULL) {
                pool_put(&pf_state_pl, st);
                pfi_kif_unref(kif, PFI_KIF_REF_NONE);
                return (ENOMEM);
        }

        /* allocate memory for scrub info */
        if (pfsync_alloc_scrub_memory(&sp->src, &st->src) ||
            pfsync_alloc_scrub_memory(&sp->dst, &st->dst)) {
                pfi_kif_unref(kif, PFI_KIF_REF_NONE);
                if (st->src.scrub)
                        pool_put(&pf_state_scrub_pl, st->src.scrub);
                pool_put(&pf_state_pl, st);
                pool_put(&pf_state_key_pl, sk);
                return (ENOMEM);
        }

        st->rule.ptr = r;
        /* XXX get pointers to nat_rule and anchor */

        /* XXX when we have nat_rule/anchors, use STATE_INC_COUNTERS */
        r->states++;

        /* fill in the rest of the state entry */
        pf_state_host_ntoh(&sp->lan, &sk->lan);
        pf_state_host_ntoh(&sp->gwy, &sk->gwy);
        pf_state_host_ntoh(&sp->ext, &sk->ext);

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

        memcpy(&st->rt_addr, &sp->rt_addr, sizeof(st->rt_addr));
        st->creation = time_second - ntohl(sp->creation);
        st->expire = ntohl(sp->expire) + time_second;

        sk->af = sp->af;
        sk->proto = sp->proto;
        sk->direction = sp->direction;
        st->log = sp->log;
        st->timeout = sp->timeout;
        st->allow_opts = sp->allow_opts;

        memcpy(&st->id, sp->id, sizeof(st->id));
        st->creatorid = sp->creatorid;
        st->sync_flags = PFSTATE_FROMSYNC;

        if (pf_insert_state(kif, st)) {
                pfi_kif_unref(kif, PFI_KIF_REF_NONE);
                /* XXX when we have nat_rule/anchors, use STATE_DEC_COUNTERS */
                r->states--;
                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 (EINVAL);
        }

        return (0);
}

void
pfsync_input(struct mbuf *m, int off, int proto)
{
        struct ip *ip = mtod(m, struct ip *);
        struct pfsync_header *ph;
        struct pfsync_softc *sc = pfsyncif;
        struct pf_state *st;
        struct pf_state_key *sk;
        struct pf_state_cmp id_key;
        struct pfsync_state *sp;
        struct pfsync_state_upd *up;
        struct pfsync_state_del *dp;
        struct pfsync_state_clr *cp;
        struct pfsync_state_upd_req *rup;
        struct pfsync_state_bus *bus;
        struct in_addr src;
        struct mbuf *mp;
        int iplen, action, error, i, s, count, offp, sfail, stale = 0;
        u_int8_t chksum_flag = 0;

        PFSYNC_STATINC(PFSYNC_STAT_IPACKETS);

        /* verify that we have a sync interface configured */
        if (!sc || !sc->sc_sync_ifp || !pf_status.running)
                goto done;

        /* verify that the packet came in on the right interface */
        if (sc->sc_sync_ifp->if_index != m->m_pkthdr.rcvif_index) {
                PFSYNC_STATINC(PFSYNC_STAT_BADIF);
                goto done;
        }

        /* verify that the IP TTL is 255.  */
        if (ip->ip_ttl != PFSYNC_DFLTTL) {
                PFSYNC_STATINC(PFSYNC_STAT_BADTTL);
                goto done;
        }

        iplen = ip->ip_hl << 2;

        if (m->m_pkthdr.len < iplen + sizeof(*ph)) {
                PFSYNC_STATINC(PFSYNC_STAT_HDROPS);
                goto done;
        }

        if (iplen + sizeof(*ph) > m->m_len) {
                if ((m = m_pullup(m, iplen + sizeof(*ph))) == NULL) {
                        PFSYNC_STATINC(PFSYNC_STAT_HDROPS);
                        goto done;
                }
                ip = mtod(m, struct ip *);
        }
        ph = (struct pfsync_header *)((char *)ip + iplen);

        /* verify the version */
        if (ph->version != PFSYNC_VERSION) {
                PFSYNC_STATINC(PFSYNC_STAT_BADVER);
                goto done;
        }

        action = ph->action;
        count = ph->count;

        /* make sure it's a valid action code */
        if (action >= PFSYNC_ACT_MAX) {
                PFSYNC_STATINC(PFSYNC_STAT_BADACT);
                goto done;
        }

        /* Cheaper to grab this now than having to mess with mbufs later */
        src = ip->ip_src;

        if (!bcmp(&ph->pf_chksum, &pf_status.pf_chksum, PF_MD5_DIGEST_LENGTH))
                chksum_flag++;

        switch (action) {
        case PFSYNC_ACT_CLR: {
                struct pf_state *nexts;
                struct pf_state_key *nextsk;
                struct pfi_kif *kif;
                u_int32_t creatorid;
                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    sizeof(*cp), &offp)) == NULL) {
                        PFSYNC_STATINC(PFSYNC_STAT_BADLEN);
                        return;
                }
                cp = (struct pfsync_state_clr *)(mp->m_data + offp);
                creatorid = cp->creatorid;

                s = splsoftnet();
                if (cp->ifname[0] == '\0') {
                        for (st = RB_MIN(pf_state_tree_id, &tree_id);
                            st; st = nexts) {
                                nexts = RB_NEXT(pf_state_tree_id, &tree_id, st);
                                if (st->creatorid == creatorid) {
                                        st->sync_flags |= PFSTATE_FROMSYNC;
                                        pf_unlink_state(st);
                                }
                        }
                } else {
                        if ((kif = pfi_kif_get(cp->ifname)) == NULL) {
                                splx(s);
                                return;
                        }
                        for (sk = RB_MIN(pf_state_tree_lan_ext,
                            &pf_statetbl_lan_ext); sk; sk = nextsk) {
                                nextsk = RB_NEXT(pf_state_tree_lan_ext,
                                    &pf_statetbl_lan_ext, sk);
                                TAILQ_FOREACH(st, &sk->states, next) {
                                        if (st->creatorid == creatorid) {
                                                st->sync_flags |=
                                                    PFSTATE_FROMSYNC;
                                                pf_unlink_state(st);
                                        }
                                }
                        }
                }
                splx(s);

                break;
        }
        case PFSYNC_ACT_INS:
                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    count * sizeof(*sp), &offp)) == NULL) {
                        PFSYNC_STATINC(PFSYNC_STAT_BADLEN);
                        return;
                }

                s = splsoftnet();
                for (i = 0, sp = (struct pfsync_state *)(mp->m_data + offp);
                    i < count; i++, sp++) {
                        /* check for invalid values */
                        if (sp->timeout >= PFTM_MAX ||
                            sp->src.state > PF_TCPS_PROXY_DST ||
                            sp->dst.state > PF_TCPS_PROXY_DST ||
                            sp->direction > PF_OUT ||
                            (sp->af != AF_INET && sp->af != AF_INET6)) {
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        printf("pfsync_insert: PFSYNC_ACT_INS: "
                                            "invalid value\n");
                                PFSYNC_STATINC(PFSYNC_STAT_BADSTATE);
                                continue;
                        }

                        if ((error = pfsync_insert_net_state(sp,
                            chksum_flag))) {
                                if (error == ENOMEM) {
                                        splx(s);
                                        goto done;
                                }
                                continue;
                        }
                }
                splx(s);
                break;
        case PFSYNC_ACT_UPD:
                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    count * sizeof(*sp), &offp)) == NULL) {
                        PFSYNC_STATINC(PFSYNC_STAT_BADLEN);
                        return;
                }

                s = splsoftnet();
                for (i = 0, sp = (struct pfsync_state *)(mp->m_data + offp);
                    i < count; i++, sp++) {
                        int flags = PFSYNC_FLAG_STALE;

                        /* check for invalid values */
                        if (sp->timeout >= PFTM_MAX ||
                            sp->src.state > PF_TCPS_PROXY_DST ||
                            sp->dst.state > PF_TCPS_PROXY_DST) {
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        printf("pfsync_insert: PFSYNC_ACT_UPD: "
                                            "invalid value\n");
                                PFSYNC_STATINC(PFSYNC_STAT_BADSTATE);
                                continue;
                        }

                        memcpy(&id_key.id, sp->id, sizeof(id_key.id));
                        id_key.creatorid = sp->creatorid;

                        st = pf_find_state_byid(&id_key);
                        if (st == NULL) {
                                /* insert the update */
                                if (pfsync_insert_net_state(sp, chksum_flag)) {
                                        PFSYNC_STATINC(PFSYNC_STAT_BADSTATE);
                                }
                                continue;
                        }
                        sk = st->state_key;
                        sfail = 0;
                        if (sk->proto == IPPROTO_TCP) {
                                /*
                                 * The state should never go backwards except
                                 * for syn-proxy states.  Neither should the
                                 * sequence window slide backwards.
                                 */
                                if (st->src.state > sp->src.state &&
                                    (st->src.state < PF_TCPS_PROXY_SRC ||
                                    sp->src.state >= PF_TCPS_PROXY_SRC))
                                        sfail = 1;
                                else if (SEQ_GT(st->src.seqlo,
                                    ntohl(sp->src.seqlo)))
                                        sfail = 3;
                                else if (st->dst.state > sp->dst.state) {
                                        /* There might still be useful
                                         * information about the src state here,
                                         * so import that part of the update,
                                         * then "fail" so we send the updated
                                         * state back to the peer who is missing
                                         * our what we know. */
                                        pf_state_peer_ntoh(&sp->src, &st->src);
                                        /* XXX do anything with timeouts? */
                                        sfail = 7;
                                        flags = 0;
                                } else if (st->dst.state >= TCPS_SYN_SENT &&
                                    SEQ_GT(st->dst.seqlo, ntohl(sp->dst.seqlo)))
                                        sfail = 4;
                        } else {
                                /*
                                 * Non-TCP protocol state machine always go
                                 * forwards
                                 */
                                if (st->src.state > sp->src.state)
                                        sfail = 5;
                                else if (st->dst.state > sp->dst.state)
                                        sfail = 6;
                        }
                        if (sfail) {
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        printf("pfsync: %s stale update "
                                            "(%d) id: %016" PRIu64 "" 
                                            "creatorid: %08x\n",
                                            (sfail < 7 ?  "ignoring"
                                             : "partial"), sfail,
                                            be64toh(st->id),
                                            ntohl(st->creatorid));
                                PFSYNC_STATINC(PFSYNC_STAT_BADSTATE);

                                if (!(sp->sync_flags & PFSTATE_STALE)) {
                                        /* we have a better state, send it */
                                        if (sc->sc_mbuf != NULL && !stale)
                                                pfsync_sendout(sc);
                                        stale++;
                                        if (!st->sync_flags)
                                                pfsync_pack_state(
                                                    PFSYNC_ACT_UPD, st, flags);
                                }
                                continue;
                        }
                        pfsync_alloc_scrub_memory(&sp->dst, &st->dst);
                        pf_state_peer_ntoh(&sp->src, &st->src);
                        pf_state_peer_ntoh(&sp->dst, &st->dst);
                        st->expire = ntohl(sp->expire) + time_second;
                        st->timeout = sp->timeout;
                }
                if (stale && sc->sc_mbuf != NULL)
                        pfsync_sendout(sc);
                splx(s);
                break;
        /*
         * It's not strictly necessary for us to support the "uncompressed"
         * delete action, but it's relatively simple and maintains consistency.
         */
        case PFSYNC_ACT_DEL:
                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    count * sizeof(*sp), &offp)) == NULL) {
                        PFSYNC_STATINC(PFSYNC_STAT_BADLEN);
                        return;
                }

                s = splsoftnet();
                for (i = 0, sp = (struct pfsync_state *)(mp->m_data + offp);
                    i < count; i++, sp++) {
                        memcpy(&id_key.id, sp->id, sizeof(id_key.id));
                        id_key.creatorid = sp->creatorid;

                        st = pf_find_state_byid(&id_key);
                        if (st == NULL) {
                                PFSYNC_STATINC(PFSYNC_STAT_BADSTATE);
                                continue;
                        }
                        st->sync_flags |= PFSTATE_FROMSYNC;
                        pf_unlink_state(st);
                }
                splx(s);
                break;
        case PFSYNC_ACT_UPD_C: {
                int update_requested = 0;

                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    count * sizeof(*up), &offp)) == NULL) {
                        PFSYNC_STATINC(PFSYNC_STAT_BADLEN);
                        return;
                }

                s = splsoftnet();
                for (i = 0, up = (struct pfsync_state_upd *)(mp->m_data + offp);
                    i < count; i++, up++) {
                        /* check for invalid values */
                        if (up->timeout >= PFTM_MAX ||
                            up->src.state > PF_TCPS_PROXY_DST ||
                            up->dst.state > PF_TCPS_PROXY_DST) {
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        printf("pfsync_insert: "
                                            "PFSYNC_ACT_UPD_C: "
                                            "invalid value\n");
                                PFSYNC_STATINC(PFSYNC_STAT_BADSTATE);
                                continue;
                        }

                        memcpy(&id_key.id, up->id, sizeof(id_key.id));
                        id_key.creatorid = up->creatorid;

                        st = pf_find_state_byid(&id_key);
                        if (st == NULL) {
                                /* We don't have this state. Ask for it. */
                                error = pfsync_request_update(up, &src);
                                if (error == ENOMEM) {
                                        splx(s);
                                        goto done;
                                }
                                update_requested = 1;
                                PFSYNC_STATINC(PFSYNC_STAT_BADSTATE);
                                continue;
                        }
                        sk = st->state_key;
                        sfail = 0;
                        if (sk->proto == IPPROTO_TCP) {
                                /*
                                 * The state should never go backwards except
                                 * for syn-proxy states.  Neither should the
                                 * sequence window slide backwards.
                                 */
                                if (st->src.state > up->src.state &&
                                    (st->src.state < PF_TCPS_PROXY_SRC ||
                                    up->src.state >= PF_TCPS_PROXY_SRC))
                                        sfail = 1;
                                else if (st->dst.state > up->dst.state)
                                        sfail = 2;
                                else if (SEQ_GT(st->src.seqlo,
                                    ntohl(up->src.seqlo)))
                                        sfail = 3;
                                else if (st->dst.state >= TCPS_SYN_SENT &&
                                    SEQ_GT(st->dst.seqlo, ntohl(up->dst.seqlo)))
                                        sfail = 4;
                        } else {
                                /*
                                 * Non-TCP protocol state machine always go
                                 * forwards
                                 */
                                if (st->src.state > up->src.state)
                                        sfail = 5;
                                else if (st->dst.state > up->dst.state)
                                        sfail = 6;
                        }
                        if (sfail) {
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        printf("pfsync: ignoring stale update "
                                            "(%d) id: %016" PRIu64 ""
                                            "creatorid: %08x\n", sfail,
                                            be64toh(st->id),
                                            ntohl(st->creatorid));
                                PFSYNC_STATINC(PFSYNC_STAT_BADSTATE);

                                /* we have a better state, send it out */
                                if ((!stale || update_requested) &&
                                    sc->sc_mbuf != NULL) {
                                        pfsync_sendout(sc);
                                        update_requested = 0;
                                }
                                stale++;
                                if (!st->sync_flags)
                                        pfsync_pack_state(PFSYNC_ACT_UPD, st,
                                            PFSYNC_FLAG_STALE);
                                continue;
                        }
                        pfsync_alloc_scrub_memory(&up->dst, &st->dst);
                        pf_state_peer_ntoh(&up->src, &st->src);
                        pf_state_peer_ntoh(&up->dst, &st->dst);
                        st->expire = ntohl(up->expire) + time_second;
                        st->timeout = up->timeout;
                }
                if ((update_requested || stale) && sc->sc_mbuf)
                        pfsync_sendout(sc);
                splx(s);
                break;
        }
        case PFSYNC_ACT_DEL_C:
                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    count * sizeof(*dp), &offp)) == NULL) {
                        PFSYNC_STATINC(PFSYNC_STAT_BADLEN);
                        return;
                }

                s = splsoftnet();
                for (i = 0, dp = (struct pfsync_state_del *)(mp->m_data + offp);
                    i < count; i++, dp++) {
                        memcpy(&id_key.id, dp->id, sizeof(id_key.id));
                        id_key.creatorid = dp->creatorid;

                        st = pf_find_state_byid(&id_key);
                        if (st == NULL) {
                                PFSYNC_STATINC(PFSYNC_STAT_BADSTATE);
                                continue;
                        }
                        st->sync_flags |= PFSTATE_FROMSYNC;
                        pf_unlink_state(st);
                }
                splx(s);
                break;
        case PFSYNC_ACT_INS_F:
        case PFSYNC_ACT_DEL_F:
                /* not implemented */
                break;
        case PFSYNC_ACT_UREQ:
                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    count * sizeof(*rup), &offp)) == NULL) {
                        PFSYNC_STATINC(PFSYNC_STAT_BADLEN);
                        return;
                }

                s = splsoftnet();
                if (sc->sc_mbuf != NULL)
                        pfsync_sendout(sc);
                for (i = 0,
                    rup = (struct pfsync_state_upd_req *)(mp->m_data + offp);
                    i < count; i++, rup++) {
                        memcpy(&id_key.id, rup->id, sizeof(id_key.id));
                        id_key.creatorid = rup->creatorid;

                        if (id_key.id == 0 && id_key.creatorid == 0) {
                                sc->sc_ureq_received = time_uptime;
                                if (sc->sc_bulk_send_next == NULL)
                                        sc->sc_bulk_send_next =
                                            TAILQ_FIRST(&state_list);
                                sc->sc_bulk_terminator = sc->sc_bulk_send_next;
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        printf("pfsync: received "
                                            "bulk update request\n");
                                pfsync_send_bus(sc, PFSYNC_BUS_START);
                                callout_schedule(&sc->sc_bulk_tmo, 1 * hz);
                        } else {
                                st = pf_find_state_byid(&id_key);
                                if (st == NULL) {
                                        PFSYNC_STATINC(PFSYNC_STAT_BADSTATE);
                                        continue;
                                }
                                if (!st->sync_flags)
                                        pfsync_pack_state(PFSYNC_ACT_UPD,
                                            st, 0);
                        }
                }
                if (sc->sc_mbuf != NULL)
                        pfsync_sendout(sc);
                splx(s);
                break;
        case PFSYNC_ACT_BUS:
                /* If we're not waiting for a bulk update, who cares. */
                if (sc->sc_ureq_sent == 0)
                        break;

                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    sizeof(*bus), &offp)) == NULL) {
                        PFSYNC_STATINC(PFSYNC_STAT_BADLEN);
                        return;
                }
                bus = (struct pfsync_state_bus *)(mp->m_data + offp);
                switch (bus->status) {
                case PFSYNC_BUS_START:
                        callout_schedule(&sc->sc_bulkfail_tmo,
                            pf_pool_limits[PF_LIMIT_STATES].limit /
                            (PFSYNC_BULKPACKETS * sc->sc_maxcount));
                        if (pf_status.debug >= PF_DEBUG_MISC)
                                printf("pfsync: received bulk "
                                    "update start\n");
                        break;
                case PFSYNC_BUS_END:
                        if (time_uptime - ntohl(bus->endtime) >=
                            sc->sc_ureq_sent) {
                                /* that's it, we're happy */
                                sc->sc_ureq_sent = 0;
                                sc->sc_bulk_tries = 0;
                                callout_stop(&sc->sc_bulkfail_tmo);
#if NCARP > 0
                                if (!pfsync_sync_ok)
                                        carp_suppress_preempt--;
#endif
                                pfsync_sync_ok = 1;
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        printf("pfsync: received valid "
                                            "bulk update end\n");
                        } else {
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        printf("pfsync: received invalid "
                                            "bulk update end: bad timestamp\n");
                        }
                        break;
                }
                break;
        }

done:
        m_freem(m);
}

int
pfsyncoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
        const struct rtentry *rt)
{
        m_freem(m);
        return (0);
}

/* ARGSUSED */
int
pfsyncioctl(struct ifnet *ifp, u_long cmd, void*  data)
{
        struct lwp *l = curlwp;
        struct pfsync_softc *sc = ifp->if_softc;
        struct ifreq *ifr = (struct ifreq *)data;
        struct ip_moptions *imo = &sc->sc_imo;
        struct pfsyncreq pfsyncr;
        struct ifnet    *sifp;
        int s, error;

        switch (cmd) {
        case SIOCSIFADDR:
        case SIOCAIFADDR:
        case SIOCSIFDSTADDR:
        case SIOCSIFFLAGS:
                if (ifp->if_flags & IFF_UP)
                        ifp->if_flags |= IFF_RUNNING;
                else
                        ifp->if_flags &= ~IFF_RUNNING;
                break;
        case SIOCSIFMTU:
                if (ifr->ifr_mtu < PFSYNC_MINMTU)
                        return (EINVAL);
                if (ifr->ifr_mtu > MCLBYTES)
                        ifr->ifr_mtu = MCLBYTES;
                s = splnet();
                if (ifr->ifr_mtu < ifp->if_mtu)
                        pfsync_sendout(sc);
                pfsync_setmtu(sc, ifr->ifr_mtu);
                splx(s);
                break;
        case SIOCGETPFSYNC:
                if ((error = kauth_authorize_network(l->l_cred,
                    KAUTH_NETWORK_INTERFACE,
                    KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, ifp, (void *)cmd,
                    NULL)) != 0)
                        return (error);
                memset(&pfsyncr, 0, sizeof(pfsyncr));
                if (sc->sc_sync_ifp)
                        strlcpy(pfsyncr.pfsyncr_syncdev,
                            sc->sc_sync_ifp->if_xname, IFNAMSIZ);
                pfsyncr.pfsyncr_syncpeer = sc->sc_sync_peer;
                pfsyncr.pfsyncr_maxupdates = sc->sc_maxupdates;
                if ((error = copyout(&pfsyncr, ifr->ifr_data, sizeof(pfsyncr))))
                        return (error);
                break;
        case SIOCSETPFSYNC:
                if ((error = kauth_authorize_network(l->l_cred,
                    KAUTH_NETWORK_INTERFACE,
                    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
                    NULL)) != 0)
                        return (error);
                if ((error = copyin(ifr->ifr_data, &pfsyncr, sizeof(pfsyncr))))
                        return (error);

                if (pfsyncr.pfsyncr_syncpeer.s_addr == 0)
                        sc->sc_sync_peer.s_addr = INADDR_PFSYNC_GROUP;
                else
                        sc->sc_sync_peer.s_addr =
                            pfsyncr.pfsyncr_syncpeer.s_addr;

                if (pfsyncr.pfsyncr_maxupdates > 255)
                        return (EINVAL);
                sc->sc_maxupdates = pfsyncr.pfsyncr_maxupdates;

                if (pfsyncr.pfsyncr_syncdev[0] == 0) {
                        sc->sc_sync_ifp = NULL;
                        if (sc->sc_mbuf_net != NULL) {
                                /* Don't keep stale pfsync packets around. */
                                s = splnet();
                                m_freem(sc->sc_mbuf_net);
                                sc->sc_mbuf_net = NULL;
                                sc->sc_statep_net.s = NULL;
                                splx(s);
                        }
                        if (imo->imo_num_memberships > 0) {
                                in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
                                imo->imo_multicast_if_index = 0;
                        }
                        break;
                }

                if ((sifp = ifunit(pfsyncr.pfsyncr_syncdev)) == NULL)
                        return (EINVAL);

                s = splnet();
                if (sifp->if_mtu < sc->sc_if.if_mtu ||
                    (sc->sc_sync_ifp != NULL &&
                    sifp->if_mtu < sc->sc_sync_ifp->if_mtu) ||
                    sifp->if_mtu < MCLBYTES - sizeof(struct ip))
                        pfsync_sendout(sc);
                sc->sc_sync_ifp = sifp;

                pfsync_setmtu(sc, sc->sc_if.if_mtu);

                if (imo->imo_num_memberships > 0) {
                        in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
                        imo->imo_multicast_if_index = 0;
                }

                if (sc->sc_sync_ifp &&
                    sc->sc_sync_peer.s_addr == INADDR_PFSYNC_GROUP) {
                        struct in_addr addr;

                        if (!(sc->sc_sync_ifp->if_flags & IFF_MULTICAST)) {
                                sc->sc_sync_ifp = NULL;
                                splx(s);
                                return (EADDRNOTAVAIL);
                        }

                        addr.s_addr = INADDR_PFSYNC_GROUP;

                        if ((imo->imo_membership[0] =
                            in_addmulti(&addr, sc->sc_sync_ifp)) == NULL) {
                                sc->sc_sync_ifp = NULL;
                                splx(s);
                                return (ENOBUFS);
                        }
                        imo->imo_num_memberships++;
                        imo->imo_multicast_if_index = if_get_index(sc->sc_sync_ifp);
                        imo->imo_multicast_ttl = PFSYNC_DFLTTL;
                        imo->imo_multicast_loop = 0;
                }

                if (sc->sc_sync_ifp ||
                    sc->sc_sendaddr.s_addr != INADDR_PFSYNC_GROUP) {
                        /* Request a full state table update. */
                        sc->sc_ureq_sent = time_uptime;
#if NCARP > 0
                        if (pfsync_sync_ok)
                                carp_suppress_preempt ++;
#endif
                        pfsync_sync_ok = 0;
                        if (pf_status.debug >= PF_DEBUG_MISC)
                                printf("pfsync: requesting bulk update\n");
                        callout_schedule(&sc->sc_bulkfail_tmo, 5 * hz);
                        error = pfsync_request_update(NULL, NULL);
                        if (error == ENOMEM) {
                                splx(s);
                                return (ENOMEM);
                        }
                        pfsync_sendout(sc);
                }
                splx(s);

                break;

        default:
                return ifioctl_common(ifp, cmd, data);
        }

        return (0);
}

void
pfsync_setmtu(struct pfsync_softc *sc, int mtu_req)
{
        int mtu;

        if (sc->sc_sync_ifp && sc->sc_sync_ifp->if_mtu < mtu_req)
                mtu = sc->sc_sync_ifp->if_mtu;
        else
                mtu = mtu_req;

        sc->sc_maxcount = (mtu - sizeof(struct pfsync_header)) /
            sizeof(struct pfsync_state);
        if (sc->sc_maxcount > 254)
            sc->sc_maxcount = 254;
        sc->sc_if.if_mtu = sizeof(struct pfsync_header) +
            sc->sc_maxcount * sizeof(struct pfsync_state);
}

struct mbuf *
pfsync_get_mbuf(struct pfsync_softc *sc, u_int8_t action, void **sp)
{
        struct pfsync_header *h;
        struct mbuf *m;
        int len;

        MGETHDR(m, M_DONTWAIT, MT_DATA);
        if (m == NULL) {
#ifdef __NetBSD__
                if_statinc(&sc->sc_if, if_oerrors);
#else
                sc->sc_if.if_oerrors++;
#endif /* __NetBSD__ */
                return (NULL);
        }

        switch (action) {
        case PFSYNC_ACT_CLR:
                len = sizeof(struct pfsync_header) +
                    sizeof(struct pfsync_state_clr);
                break;
        case PFSYNC_ACT_UPD_C:
                len = (sc->sc_maxcount * sizeof(struct pfsync_state_upd)) +
                    sizeof(struct pfsync_header);
                break;
        case PFSYNC_ACT_DEL_C:
                len = (sc->sc_maxcount * sizeof(struct pfsync_state_del)) +
                    sizeof(struct pfsync_header);
                break;
        case PFSYNC_ACT_UREQ:
                len = (sc->sc_maxcount * sizeof(struct pfsync_state_upd_req)) +
                    sizeof(struct pfsync_header);
                break;
        case PFSYNC_ACT_BUS:
                len = sizeof(struct pfsync_header) +
                    sizeof(struct pfsync_state_bus);
                break;
        case PFSYNC_ACT_TDB_UPD:
                len = (sc->sc_maxcount * sizeof(struct pfsync_tdb)) +
                    sizeof(struct pfsync_header);
                break;
        default:
                len = (sc->sc_maxcount * sizeof(struct pfsync_state)) +
                    sizeof(struct pfsync_header);
                break;
        }

        if (len > MHLEN) {
                MCLGET(m, M_DONTWAIT);
                if ((m->m_flags & M_EXT) == 0) {
                        m_free(m);
#ifdef __NetBSD__
                        if_statinc(&sc->sc_if, if_oerrors);
#else
                        sc->sc_if.if_oerrors++;
#endif /* __NetBSD__ */
                        return (NULL);
                }
                m->m_data += (MCLBYTES - len) &~ (sizeof(long) - 1);
        } else
                m_align(m, len);

        m_reset_rcvif(m);
        m->m_pkthdr.len = m->m_len = sizeof(struct pfsync_header);
        h = mtod(m, struct pfsync_header *);
        h->version = PFSYNC_VERSION;
        h->af = 0;
        h->count = 0;
        h->action = action;
        if (action != PFSYNC_ACT_TDB_UPD)
                memcpy(&h->pf_chksum, &pf_status.pf_chksum, 
                    PF_MD5_DIGEST_LENGTH);

        *sp = (void *)((char *)h + PFSYNC_HDRLEN);
        if (action == PFSYNC_ACT_TDB_UPD)
                callout_schedule(&sc->sc_tdb_tmo, hz);
        else
                callout_schedule(&sc->sc_tmo, hz);
        return (m);
}

int
pfsync_pack_state(u_int8_t action, struct pf_state *st, int flags)
{
        struct ifnet *ifp = NULL;
        struct pfsync_softc *sc = pfsyncif;
        struct pfsync_header *h, *h_net;
        struct pfsync_state *sp = NULL;
        struct pfsync_state_upd *up = NULL;
        struct pfsync_state_del *dp = NULL;
        struct pf_state_key *sk = st->state_key;
        struct pf_rule *r;
        u_long secs;
        int s, ret = 0;
        u_int8_t i = 255, newaction = 0;

        if (sc == NULL)
                return (0);
        ifp = &sc->sc_if;

        /*
         * If a packet falls in the forest and there's nobody around to
         * hear, does it make a sound?
         */
        if (ifp->if_bpf == NULL && sc->sc_sync_ifp == NULL &&
            sc->sc_sync_peer.s_addr == INADDR_PFSYNC_GROUP) {
                /* Don't leave any stale pfsync packets hanging around. */
                if (sc->sc_mbuf != NULL) {
                        m_freem(sc->sc_mbuf);
                        sc->sc_mbuf = NULL;
                        sc->sc_statep.s = NULL;
                }
                return (0);
        }

        if (action >= PFSYNC_ACT_MAX)
                return (EINVAL);

        s = splnet();
        if (sc->sc_mbuf == NULL) {
                if ((sc->sc_mbuf = pfsync_get_mbuf(sc, action,
                    (void *)&sc->sc_statep.s)) == NULL) {
                        splx(s);
                        return (ENOMEM);
                }
                h = mtod(sc->sc_mbuf, struct pfsync_header *);
        } else {
                h = mtod(sc->sc_mbuf, struct pfsync_header *);
                if (h->action != action) {
                        pfsync_sendout(sc);
                        if ((sc->sc_mbuf = pfsync_get_mbuf(sc, action,
                            (void *)&sc->sc_statep.s)) == NULL) {
                                splx(s);
                                return (ENOMEM);
                        }
                        h = mtod(sc->sc_mbuf, struct pfsync_header *);
                } else {
                        /*
                         * If it's an update, look in the packet to see if
                         * we already have an update for the state.
                         */
                        if (action == PFSYNC_ACT_UPD && sc->sc_maxupdates) {
                                struct pfsync_state *usp =
                                    (void *)((char *)h + PFSYNC_HDRLEN);

                                for (i = 0; i < h->count; i++) {
                                        if (!memcmp(usp->id, &st->id,
                                            PFSYNC_ID_LEN) &&
                                            usp->creatorid == st->creatorid) {
                                                sp = usp;
                                                sp->updates++;
                                                break;
                                        }
                                        usp++;
                                }
                        }
                }
        }

        secs = time_second;

        st->pfsync_time = time_uptime;

        if (sp == NULL) {
                /* not a "duplicate" update */
                i = 255;
                sp = sc->sc_statep.s++;
                sc->sc_mbuf->m_pkthdr.len =
                    sc->sc_mbuf->m_len += sizeof(struct pfsync_state);
                h->count++;
                memset(sp, 0, sizeof(*sp));

                memcpy(sp->id, &st->id, sizeof(sp->id));
                sp->creatorid = st->creatorid;

                strlcpy(sp->ifname, st->kif->pfik_name, sizeof(sp->ifname));
                pf_state_host_hton(&sk->lan, &sp->lan);
                pf_state_host_hton(&sk->gwy, &sp->gwy);
                pf_state_host_hton(&sk->ext, &sp->ext);

                memcpy(&sp->rt_addr, &st->rt_addr, sizeof(sp->rt_addr));

                sp->creation = htonl(secs - st->creation);
                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]);
                if ((r = st->rule.ptr) == NULL)
                        sp->rule = htonl(-1);
                else
                        sp->rule = htonl(r->nr);
                if ((r = st->anchor.ptr) == NULL)
                        sp->anchor = htonl(-1);
                else
                        sp->anchor = htonl(r->nr);
                sp->af = sk->af;
                sp->proto = sk->proto;
                sp->direction = sk->direction;
                sp->log = st->log;
                sp->allow_opts = st->allow_opts;
                sp->timeout = st->timeout;

                if (flags & PFSYNC_FLAG_STALE)
                        sp->sync_flags |= PFSTATE_STALE;
        }

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

        if (st->expire <= secs)
                sp->expire = htonl(0);
        else
                sp->expire = htonl(st->expire - secs);

        /* do we need to build "compressed" actions for network transfer? */
        if (sc->sc_sync_ifp && flags & PFSYNC_FLAG_COMPRESS) {
                switch (action) {
                case PFSYNC_ACT_UPD:
                        newaction = PFSYNC_ACT_UPD_C;
                        break;
                case PFSYNC_ACT_DEL:
                        newaction = PFSYNC_ACT_DEL_C;
                        break;
                default:
                        /* by default we just send the uncompressed states */
                        break;
                }
        }

        if (newaction) {
                if (sc->sc_mbuf_net == NULL) {
                        if ((sc->sc_mbuf_net = pfsync_get_mbuf(sc, newaction,
                            (void *)&sc->sc_statep_net.s)) == NULL) {
                                splx(s);
                                return (ENOMEM);
                        }
                }
                h_net = mtod(sc->sc_mbuf_net, struct pfsync_header *);

                switch (newaction) {
                case PFSYNC_ACT_UPD_C:
                        if (i != 255) {
                                up = (void *)((char *)h_net +
                                    PFSYNC_HDRLEN + (i * sizeof(*up)));
                                up->updates++;
                        } else {
                                h_net->count++;
                                sc->sc_mbuf_net->m_pkthdr.len =
                                    sc->sc_mbuf_net->m_len += sizeof(*up);
                                up = sc->sc_statep_net.u++;

                                memset(up, 0, sizeof(*up));
                                memcpy(up->id, &st->id, sizeof(up->id));
                                up->creatorid = st->creatorid;
                        }
                        up->timeout = st->timeout;
                        up->expire = sp->expire;
                        up->src = sp->src;
                        up->dst = sp->dst;
                        break;
                case PFSYNC_ACT_DEL_C:
                        sc->sc_mbuf_net->m_pkthdr.len =
                            sc->sc_mbuf_net->m_len += sizeof(*dp);
                        dp = sc->sc_statep_net.d++;
                        h_net->count++;

                        memset(dp, 0, sizeof(*dp));
                        memcpy(dp->id, &st->id, sizeof(dp->id));
                        dp->creatorid = st->creatorid;
                        break;
                }
        }

        if (h->count == sc->sc_maxcount ||
            (sc->sc_maxupdates && (sp->updates >= sc->sc_maxupdates)))
                ret = pfsync_sendout(sc);

        splx(s);
        return (ret);
}

/* This must be called in splnet() */
int
pfsync_request_update(struct pfsync_state_upd *up, struct in_addr *src)
{
        struct pfsync_header *h;
        struct pfsync_softc *sc = pfsyncif;
        struct pfsync_state_upd_req *rup;
        int ret = 0;

        if (sc == NULL)
                return (0);

        if (sc->sc_mbuf == NULL) {
                if ((sc->sc_mbuf = pfsync_get_mbuf(sc, PFSYNC_ACT_UREQ,
                    (void *)&sc->sc_statep.s)) == NULL)
                        return (ENOMEM);
                h = mtod(sc->sc_mbuf, struct pfsync_header *);
        } else {
                h = mtod(sc->sc_mbuf, struct pfsync_header *);
                if (h->action != PFSYNC_ACT_UREQ) {
                        pfsync_sendout(sc);
                        if ((sc->sc_mbuf = pfsync_get_mbuf(sc, PFSYNC_ACT_UREQ,
                            (void *)&sc->sc_statep.s)) == NULL)
                                return (ENOMEM);
                        h = mtod(sc->sc_mbuf, struct pfsync_header *);
                }
        }

        if (src != NULL)
                sc->sc_sendaddr = *src;
        sc->sc_mbuf->m_pkthdr.len = sc->sc_mbuf->m_len += sizeof(*rup);
        h->count++;
        rup = sc->sc_statep.r++;
        memset(rup, 0, sizeof(*rup));
        if (up != NULL) {
                memcpy(rup->id, up->id, sizeof(rup->id));
                rup->creatorid = up->creatorid;
        }

        if (h->count == sc->sc_maxcount)
                ret = pfsync_sendout(sc);

        return (ret);
}

int
pfsync_clear_states(u_int32_t creatorid, char *ifname)
{
        struct pfsync_softc *sc = pfsyncif;
        struct pfsync_state_clr *cp;
        int s, ret;

        if (sc == NULL)
                return (0);

        s = splnet();
        if (sc->sc_mbuf != NULL)
                pfsync_sendout(sc);
        if ((sc->sc_mbuf = pfsync_get_mbuf(sc, PFSYNC_ACT_CLR,
            (void *)&sc->sc_statep.c)) == NULL) {
                splx(s);
                return (ENOMEM);
        }
        sc->sc_mbuf->m_pkthdr.len = sc->sc_mbuf->m_len += sizeof(*cp);
        cp = sc->sc_statep.c;
        cp->creatorid = creatorid;
        if (ifname != NULL)
                strlcpy(cp->ifname, ifname, IFNAMSIZ);

        ret = (pfsync_sendout(sc));
        splx(s);
        return (ret);
}

void
pfsync_timeout(void *v)
{
        struct pfsync_softc *sc = v;
        int s;

        s = splnet();
        pfsync_sendout(sc);
        splx(s);
}

void
pfsync_tdb_timeout(void *v)
{
        struct pfsync_softc *sc = v;
        int s;

        s = splnet();
        pfsync_tdb_sendout(sc);
        splx(s);
}

/* This must be called in splnet() */
void
pfsync_send_bus(struct pfsync_softc *sc, u_int8_t status)
{
        struct pfsync_state_bus *bus;

        if (sc->sc_mbuf != NULL)
                pfsync_sendout(sc);

        if (pfsync_sync_ok &&
            (sc->sc_mbuf = pfsync_get_mbuf(sc, PFSYNC_ACT_BUS,
            (void *)&sc->sc_statep.b)) != NULL) {
                sc->sc_mbuf->m_pkthdr.len = sc->sc_mbuf->m_len += sizeof(*bus);
                bus = sc->sc_statep.b;
                bus->creatorid = pf_status.hostid;
                bus->status = status;
                bus->endtime = htonl(time_uptime - sc->sc_ureq_received);
                pfsync_sendout(sc);
        }
}

void
pfsync_bulk_update(void *v)
{
        struct pfsync_softc *sc = v;
        int s, i = 0;
        struct pf_state *state;

        s = splnet();
        if (sc->sc_mbuf != NULL)
                pfsync_sendout(sc);

        /*
         * Grab at most PFSYNC_BULKPACKETS worth of states which have not
         * been sent since the latest request was made.
         */
        state = sc->sc_bulk_send_next;
        if (state)
                do {
                        /* send state update if syncable and not already sent */
                        if (!state->sync_flags
                            && state->timeout < PFTM_MAX
                            && state->pfsync_time <= sc->sc_ureq_received) {
                                pfsync_pack_state(PFSYNC_ACT_UPD, state, 0);
                                i++;
                        }

                        /* figure next state to send */
                        state = TAILQ_NEXT(state, entry_list);

                        /* wrap to start of list if we hit the end */
                        if (!state)
                                state = TAILQ_FIRST(&state_list);
                } while (i < sc->sc_maxcount * PFSYNC_BULKPACKETS &&
                    state != sc->sc_bulk_terminator);

        if (!state || state == sc->sc_bulk_terminator) {
                /* we're done */
                pfsync_send_bus(sc, PFSYNC_BUS_END);
                sc->sc_ureq_received = 0;
                sc->sc_bulk_send_next = NULL;
                sc->sc_bulk_terminator = NULL;
                callout_stop(&sc->sc_bulk_tmo);
                if (pf_status.debug >= PF_DEBUG_MISC)
                        printf("pfsync: bulk update complete\n");
        } else {
                /* look again for more in a bit */
                callout_schedule(&sc->sc_bulk_tmo, 1);
                sc->sc_bulk_send_next = state;
        }
        if (sc->sc_mbuf != NULL)
                pfsync_sendout(sc);
        splx(s);
}

void
pfsync_bulkfail(void *v)
{
        struct pfsync_softc *sc = v;
        int s, error;

        if (sc->sc_bulk_tries++ < PFSYNC_MAX_BULKTRIES) {
                /* Try again in a bit */
                callout_schedule(&sc->sc_bulkfail_tmo, 5 * hz);
                s = splnet();
                error = pfsync_request_update(NULL, NULL);
                if (error == ENOMEM) {
                        if (pf_status.debug >= PF_DEBUG_MISC)
                                printf("pfsync: cannot allocate mbufs for "
                                    "bulk update\n");
                } else
                        pfsync_sendout(sc);
                splx(s);
        } else {
                /* Pretend like the transfer was ok */
                sc->sc_ureq_sent = 0;
                sc->sc_bulk_tries = 0;
#if NCARP > 0
                if (!pfsync_sync_ok)
                        carp_suppress_preempt --;
#endif
                pfsync_sync_ok = 1;
                if (pf_status.debug >= PF_DEBUG_MISC)
                        printf("pfsync: failed to receive "
                            "bulk update status\n");
                callout_stop(&sc->sc_bulkfail_tmo);
        }
}

/* This must be called in splnet() */
int
pfsync_sendout(struct pfsync_softc *sc)
{
        struct ifnet *ifp = &sc->sc_if;
        struct mbuf *m;

        callout_stop(&sc->sc_tmo);

        if (sc->sc_mbuf == NULL)
                return (0);
        m = sc->sc_mbuf;
        sc->sc_mbuf = NULL;
        sc->sc_statep.s = NULL;

        bpf_mtap(ifp, m, BPF_D_OUT);

        if (sc->sc_mbuf_net) {
                m_freem(m);
                m = sc->sc_mbuf_net;
                sc->sc_mbuf_net = NULL;
                sc->sc_statep_net.s = NULL;
        }

        return pfsync_sendout_mbuf(sc, m);
}

int
pfsync_tdb_sendout(struct pfsync_softc *sc)
{
        struct ifnet *ifp = &sc->sc_if;
        struct mbuf *m;

        callout_stop(&sc->sc_tdb_tmo);

        if (sc->sc_mbuf_tdb == NULL)
                return (0);
        m = sc->sc_mbuf_tdb;
        sc->sc_mbuf_tdb = NULL;
        sc->sc_statep_tdb.t = NULL;

        bpf_mtap(ifp, m, BPF_D_OUT);

        return pfsync_sendout_mbuf(sc, m);
}

int
pfsync_sendout_mbuf(struct pfsync_softc *sc, struct mbuf *m)
{
        struct sockaddr sa;
        struct ip *ip;

        if (sc->sc_sync_ifp ||
            sc->sc_sync_peer.s_addr != INADDR_PFSYNC_GROUP) {
                M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
                if (m == NULL) {
                        PFSYNC_STATINC(PFSYNC_STAT_ONOMEM);
                        return (0);
                }
                ip = mtod(m, struct ip *);
                ip->ip_v = IPVERSION;
                ip->ip_hl = sizeof(*ip) >> 2;
                ip->ip_tos = IPTOS_LOWDELAY;
                ip->ip_len = htons(m->m_pkthdr.len);
                ip->ip_id = ip_randomid();
                ip->ip_off = htons(IP_DF);
                ip->ip_ttl = PFSYNC_DFLTTL;
                ip->ip_p = IPPROTO_PFSYNC;
                ip->ip_sum = 0;

                memset(&sa, 0, sizeof(sa));
                ip->ip_src.s_addr = INADDR_ANY;

                if (sc->sc_sendaddr.s_addr == INADDR_PFSYNC_GROUP)
                        m->m_flags |= M_MCAST;
                ip->ip_dst = sc->sc_sendaddr;
                sc->sc_sendaddr.s_addr = sc->sc_sync_peer.s_addr;

                PFSYNC_STATINC(PFSYNC_STAT_OPACKETS);

                if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL)) {
                        PFSYNC_STATINC(PFSYNC_STAT_OERRORS);
                }
        } else
                m_freem(m);

        return (0);
}

static int
sysctl_net_inet_pfsync_stats(SYSCTLFN_ARGS)
{

        return (NETSTAT_SYSCTL(pfsyncstat_percpu, PFSYNC_NSTATS));
}

SYSCTL_SETUP(sysctl_net_inet_pfsync_setup, "sysctl net.inet.pfsync subtree setup")
{

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "net", NULL,
                       NULL, 0, NULL, 0,
                       CTL_NET, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "inet", NULL,
                       NULL, 0, NULL, 0,
                       CTL_NET, PF_INET, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "pfsync",
                       SYSCTL_DESCR("pfsync related settings"),
                       NULL, 0, NULL, 0,
                       CTL_NET, PF_INET, IPPROTO_PFSYNC, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READONLY,
                       CTLTYPE_STRUCT, "stats", 
                           SYSCTL_DESCR("pfsync statistics"),
                       sysctl_net_inet_pfsync_stats, 0, NULL, 0,
                       CTL_NET, PF_INET, IPPROTO_PFSYNC,
               CTL_CREATE, CTL_EOL);
}