/*
 * 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.
 *
 * $OpenBSD: if_pfsync.c,v 1.98 2008/06/29 08:42:15 mcbride Exp $
 */

#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_carp.h"
#include "use_bpf.h"

#include <sys/param.h>
#include <sys/endian.h>
#include <sys/proc.h>
#include <sys/caps.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/msgport2.h>
#include <sys/sockio.h>
#include <sys/thread2.h>

#include <machine/inttypes.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/ifq_var.h>
#include <net/route.h>
#include <net/bpf.h>
#include <net/netisr2.h>
#include <net/netmsg2.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netinet/ip_carp.h>
#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 <net/pf/pfvar.h>
#include <net/pf/if_pfsync.h>

#define PFSYNCNAME      "pfsync"

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

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

struct pfsync_softc     *pfsyncif = NULL;
struct pfsyncstats       pfsyncstats;

void    pfsyncattach(int);
static int      pfsync_clone_destroy(struct ifnet *);
static int      pfsync_clone_create(struct if_clone *, int, caddr_t, caddr_t);
void    pfsync_setmtu(struct pfsync_softc *, int);
int     pfsync_alloc_scrub_memory(struct pfsync_state_peer *,
            struct pf_state_peer *);
int     pfsyncoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
            struct rtentry *);
int     pfsyncioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
void    pfsyncstart(struct ifnet *, struct ifaltq_subque *);

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_sendout_mbuf(struct pfsync_softc *, struct mbuf *);
void    pfsync_timeout(void *);
void    pfsync_send_bus(struct pfsync_softc *, u_int8_t);
void    pfsync_bulk_update(void *);
void    pfsync_bulkfail(void *);

static struct in_multi *pfsync_in_addmulti(struct ifnet *);
static void pfsync_in_delmulti(struct in_multi *);

static MALLOC_DEFINE(M_PFSYNC, PFSYNCNAME, "Packet Filter State Sync. Interface");
static LIST_HEAD(pfsync_list, pfsync_softc) pfsync_list;

int     pfsync_sync_ok;

struct if_clone pfsync_cloner =
    IF_CLONE_INITIALIZER("pfsync", pfsync_clone_create, pfsync_clone_destroy, 1 ,1);


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

static int
pfsync_clone_create(struct if_clone *ifc, int unit,
                    caddr_t params __unused, caddr_t data __unused)
{
        struct pfsync_softc *sc;
        struct ifnet *ifp;

        lwkt_gettoken(&pf_token);

        pfsync_sync_ok = 1;

        sc = kmalloc(sizeof(*sc), M_PFSYNC, M_WAITOK | M_ZERO);
        sc->sc_mbuf = NULL;
        sc->sc_mbuf_net = NULL;
        sc->sc_mbuf_tdb = NULL;
        sc->sc_statep.s = NULL;
        sc->sc_statep_net.s = NULL;
        sc->sc_statep_tdb.t = NULL;
        sc->sc_maxupdates = 128;
        sc->sc_sync_peer.s_addr =htonl(INADDR_PFSYNC_GROUP);
        sc->sc_sendaddr.s_addr = htonl(INADDR_PFSYNC_GROUP);
        sc->sc_ureq_received = 0;
        sc->sc_ureq_sent = 0;
        sc->sc_bulk_send_next = NULL;
        sc->sc_bulk_terminator = NULL;
        sc->sc_bulk_send_cpu = 0;
        sc->sc_bulk_terminator_cpu = 0;
        sc->sc_imo.imo_max_memberships = IP_MAX_MEMBERSHIPS;
        lwkt_reltoken(&pf_token);

        ifp = &sc->sc_if;
        if_initname(ifp, ifc->ifc_name, unit);
        ifp->if_ioctl = pfsyncioctl;
        ifp->if_output = pfsyncoutput;
        ifp->if_start = pfsyncstart;
        ifp->if_type = IFT_PFSYNC;
        ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
        ifp->if_hdrlen = PFSYNC_HDRLEN;
        ifp->if_baudrate = IF_Mbps(100);
        ifp->if_softc = sc;

        pfsync_setmtu(sc, MCLBYTES);
        callout_init(&sc->sc_tmo);
        /* callout_init(&sc->sc_tdb_tmo); XXX we don't support tdb (yet) */
        callout_init(&sc->sc_bulk_tmo);
        callout_init(&sc->sc_bulkfail_tmo);

        if_attach(ifp, NULL);
#if NBPF > 0
        bpfattach(&sc->sc_if, DLT_PFSYNC, PFSYNC_HDRLEN);
#endif

#ifdef CARP
        if_addgroup(ifp, "carp");
#endif

        lwkt_gettoken(&pf_token);
        LIST_INSERT_HEAD(&pfsync_list, sc, sc_next);
        lwkt_reltoken(&pf_token);

        return (0);
}

static int
pfsync_clone_destroy(struct ifnet *ifp)
{
        struct netmsg_base msg;

        lwkt_gettoken(&pf_token);
        lwkt_reltoken(&pf_token);

        struct pfsync_softc *sc = ifp->if_softc;
        callout_stop(&sc->sc_tmo);
        /* callout_stop(&sc->sc_tdb_tmo); XXX we don't support tdb (yet) */
        callout_stop(&sc->sc_bulk_tmo);
        callout_stop(&sc->sc_bulkfail_tmo);
#ifdef CARP
        if (!pfsync_sync_ok)
                carp_group_demote_adj(&sc->sc_if, -1);
#endif

        /* Unpend async sendouts. */
        netmsg_init(&msg, NULL, &curthread->td_msgport, 0, netmsg_sync_handler);
        netisr_domsg(&msg, 0);

#if NBPF > 0
        bpfdetach(ifp);
#endif
        if_detach(ifp);
        lwkt_gettoken(&pf_token);
        LIST_REMOVE(sc, sc_next);
        kfree(sc, M_PFSYNC);
        lwkt_reltoken(&pf_token);

        return 0;
}

/*
 * Start output on the pfsync interface.
 */
void
pfsyncstart(struct ifnet *ifp, struct ifaltq_subque *ifsq)
{
        ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);
        ifsq_purge(ifsq);
}

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 = kmalloc(sizeof(struct pf_state_scrub), M_PFSYNC, M_NOWAIT|M_ZERO);

                if (d->scrub == NULL)
                        return (ENOMEM);
        }

        return (0);
}

void
pfsync_state_export(struct pfsync_state *sp, struct pf_state *st)
{
        bzero(sp, 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_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->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));
        bcopy(&st->rt_addr, &sp->rt_addr, sizeof(sp->rt_addr));
        sp->creation = htonl(time_second - st->creation);
        sp->expire = pf_state_expires(st);
        if (sp->expire <= time_second)
                sp->expire = htonl(0);
        else
                sp->expire = htonl(sp->expire - time_second);

        sp->direction = st->direction;
        sp->log = st->log;
        sp->cpuid = st->cpuid;
        sp->pickup_mode = st->pickup_mode;
        sp->timeout = st->timeout;
        sp->state_flags = st->state_flags;
        if (st->src_node)
                sp->sync_flags |= PFSYNC_FLAG_SRCNODE;
        if (st->nat_src_node)
                sp->sync_flags |= PFSYNC_FLAG_NATSRCNODE;

        bcopy(&st->id, &sp->id, sizeof(sp->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);
        if (st->nat_rule.ptr == NULL)
                sp->nat_rule = htonl(-1);
        else
                sp->nat_rule = htonl(st->nat_rule.ptr->nr);

        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]);

}

int
pfsync_state_import(struct pfsync_state *sp, u_int8_t 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;

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

        if ((kif = pfi_kif_get(sp->ifname)) == NULL) {
                if (pf_status.debug >= PF_DEBUG_MISC)
                        kprintf("pfsync_insert_net_state: "
                            "unknown interface: %s\n", sp->ifname);
                if (flags & PFSYNC_SI_IOCTL)
                        return (EINVAL);
                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[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_cur >= r->max_states))
                goto cleanup;

        if (flags & PFSYNC_SI_IOCTL)
                pool_flags = M_WAITOK | M_NULLOK | M_ZERO;
        else
                pool_flags = M_WAITOK | M_ZERO;

        if ((st = kmalloc(sizeof(struct pf_state), M_PFSYNC, pool_flags)) == NULL)
                goto cleanup;
        lockinit(&st->lk, "pfstlk", 0, 0);

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

        if (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]) {
                if ((sks = pf_alloc_state_key(pool_flags)) == NULL)
                        goto cleanup;
        } else
                sks = skw;

        /* allocate memory for scrub info */
        if (pfsync_alloc_scrub_memory(&sp->src, &st->src) ||
            pfsync_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->proto = sp->proto;
        skw->af = sp->af;
        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->proto = sp->proto;
                sks->af = sp->af;
        }

        /* copy to state */
        bcopy(&sp->rt_addr, &st->rt_addr, sizeof(st->rt_addr));
        st->creation = time_second - ntohl(sp->creation);
        st->expire = time_second;
        if (sp->expire) {
                /* XXX No adaptive scaling. */
                st->expire -= r->timeout[sp->timeout] - ntohl(sp->expire);
        }

        st->expire = ntohl(sp->expire) + time_second;
        st->direction = sp->direction;
        st->log = sp->log;
        st->timeout = sp->timeout;
        st->state_flags = sp->state_flags;
        if (!(flags & PFSYNC_SI_IOCTL))
                st->sync_flags = PFSTATE_FROMSYNC;

        bcopy(sp->id, &st->id, sizeof(st->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->nat_rule.ptr = NULL;
        st->anchor.ptr = NULL;
        st->rt_kif = NULL;

        st->pfsync_time = 0;


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

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

        return (0);

 cleanup:
        error = ENOMEM;
        if (skw == sks)
                sks = NULL;
        if (skw != NULL)
                kfree(skw, M_PFSYNC);
        if (sks != NULL)
                kfree(sks, M_PFSYNC);

 cleanup_state: /* pf_state_insert frees the state keys */
        if (st) {
                if (st->dst.scrub)
                        kfree(st->dst.scrub, M_PFSYNC);
                if (st->src.scrub)
                        kfree(st->src.scrub, M_PFSYNC);
                kfree(st, M_PFSYNC);
        }
        return (error);
}

void
pfsync_input(struct mbuf *m, ...)
{
        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_item *si;
        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, count, offp, sfail, stale = 0;
        u_int8_t flags = 0;

        /* This function is not yet called from anywhere */
        /* Still we assume for safety that pf_token must be held */
        ASSERT_LWKT_TOKEN_HELD(&pf_token);

        pfsyncstats.pfsyncs_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 != m->m_pkthdr.rcvif) {
                pfsyncstats.pfsyncs_badif++;
                goto done;
        }

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

        iplen = ip->ip_hl << 2;

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

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

        /* verify the version */
        if (ph->version != PFSYNC_VERSION) {
                pfsyncstats.pfsyncs_badver++;
                goto done;
        }

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

        /* make sure it's a valid action code */
        if (action >= PFSYNC_ACT_MAX) {
                pfsyncstats.pfsyncs_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))
                flags |= PFSYNC_SI_CKSUM;

        switch (action) {
        case PFSYNC_ACT_CLR: {
                struct pf_state *nexts;
                struct pf_state_key *nextsk;
                struct pfi_kif *kif;
                globaldata_t save_gd = mycpu;
                int nn;

                u_int32_t creatorid;
                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    sizeof(*cp), &offp)) == NULL) {
                        pfsyncstats.pfsyncs_badlen++;
                        return;
                }
                cp = (struct pfsync_state_clr *)(mp->m_data + offp);
                creatorid = cp->creatorid;

                crit_enter();
                if (cp->ifname[0] == '\0') {
                        lwkt_gettoken(&pf_token);
                        for (nn = 0; nn < ncpus; ++nn) {
                                lwkt_setcpu_self(globaldata_find(nn));
                                for (st = RB_MIN(pf_state_tree_id,
                                                 &tree_id[nn]);
                                     st; st = nexts) {
                                        nexts = RB_NEXT(pf_state_tree_id,
                                                        &tree_id[n], st);
                                        if (st->creatorid == creatorid) {
                                                st->sync_flags |=
                                                        PFSTATE_FROMSYNC;
                                                pf_unlink_state(st);
                                        }
                                }
                        }
                        lwkt_setcpu_self(save_gd);
                        lwkt_reltoken(&pf_token);
                } else {
                        if ((kif = pfi_kif_get(cp->ifname)) == NULL) {
                                crit_exit();
                                return;
                        }
                        /* XXX correct? */
                        lwkt_gettoken(&pf_token);
                        for (nn = 0; nn < ncpus; ++nn) {
                                lwkt_setcpu_self(globaldata_find(nn));
                                for (sk = RB_MIN(pf_state_tree,
                                                 &pf_statetbl[nn]);
                                     sk;
                                     sk = nextsk) {
                                        nextsk = RB_NEXT(pf_state_tree,
                                            &pf_statetbl[n], sk);
                                        TAILQ_FOREACH(si, &sk->states, entry) {
                                                if (si->s->creatorid ==
                                                    creatorid) {
                                                        si->s->sync_flags |=
                                                            PFSTATE_FROMSYNC;
                                                        pf_unlink_state(si->s);
                                                }
                                        }
                                }
                        }
                        lwkt_setcpu_self(save_gd);
                        lwkt_reltoken(&pf_token);
                }
                crit_exit();

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

                crit_enter();
                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)
                                        kprintf("pfsync_insert: PFSYNC_ACT_INS: "
                                            "invalid value\n");
                                pfsyncstats.pfsyncs_badval++;
                                continue;
                        }

                        if ((error = pfsync_state_import(sp, flags))) {
                                if (error == ENOMEM) {
                                        crit_exit();
                                        goto done;
                                }
                        }
                }
                crit_exit();
                break;
        case PFSYNC_ACT_UPD:
                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    count * sizeof(*sp), &offp)) == NULL) {
                        pfsyncstats.pfsyncs_badlen++;
                        return;
                }

                crit_enter();
                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)
                                        kprintf("pfsync_insert: PFSYNC_ACT_UPD: "
                                            "invalid value\n");
                                pfsyncstats.pfsyncs_badval++;
                                continue;
                        }

                        bcopy(sp->id, &id_key.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_state_import(sp, flags))
                                        pfsyncstats.pfsyncs_badstate++;
                                continue;
                        }
                        sk = st->key[PF_SK_WIRE];       /* XXX right one? */
                        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)
                                        kprintf("pfsync: %s stale update "
                                            "(%d) id: %016jx "
                                            "creatorid: %08x\n",
                                            (sfail < 7 ?  "ignoring"
                                             : "partial"), sfail,
                                            (uintmax_t)be64toh(st->id),
                                            ntohl(st->creatorid));
                                pfsyncstats.pfsyncs_stale++;

                                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);
                crit_exit();
                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) {
                        pfsyncstats.pfsyncs_badlen++;
                        return;
                }

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

                        st = pf_find_state_byid(&id_key);
                        if (st == NULL) {
                                pfsyncstats.pfsyncs_badstate++;
                                continue;
                        }
                        st->sync_flags |= PFSTATE_FROMSYNC;
                        pf_unlink_state(st);
                }
                crit_exit();
                break;
        case PFSYNC_ACT_UPD_C: {
                int update_requested = 0;

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

                crit_enter();
                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)
                                        kprintf("pfsync_insert: "
                                            "PFSYNC_ACT_UPD_C: "
                                            "invalid value\n");
                                pfsyncstats.pfsyncs_badval++;
                                continue;
                        }

                        bcopy(up->id, &id_key.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) {
                                        crit_exit();
                                        goto done;
                                }
                                update_requested = 1;
                                pfsyncstats.pfsyncs_badstate++;
                                continue;
                        }
                        sk = st->key[PF_SK_WIRE]; /* XXX right one? */
                        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)
                                        kprintf("pfsync: ignoring stale update "
                                            "(%d) id: %016" PRIx64 " "
                                            "creatorid: %08x\n", sfail,
                                            be64toh(st->id),
                                            ntohl(st->creatorid));
                                pfsyncstats.pfsyncs_stale++;

                                /* 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);
                crit_exit();
                break;
        }
        case PFSYNC_ACT_DEL_C:
                if ((mp = m_pulldown(m, iplen + sizeof(*ph),
                    count * sizeof(*dp), &offp)) == NULL) {
                        pfsyncstats.pfsyncs_badlen++;
                        return;
                }

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

                        st = pf_find_state_byid(&id_key);
                        if (st == NULL) {
                                pfsyncstats.pfsyncs_badstate++;
                                continue;
                        }
                        st->sync_flags |= PFSTATE_FROMSYNC;
                        pf_unlink_state(st);
                }
                crit_exit();
                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) {
                        pfsyncstats.pfsyncs_badlen++;
                        return;
                }

                crit_enter();
                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++) {
                        bcopy(rup->id, &id_key.id, sizeof(id_key.id));
                        id_key.creatorid = rup->creatorid;

                        if (id_key.id == 0 && id_key.creatorid == 0) {
                                sc->sc_ureq_received = mycpu->gd_time_seconds;
                                if (sc->sc_bulk_send_next == NULL) {
                                        if (++sc->sc_bulk_send_cpu >= ncpus)
                                                sc->sc_bulk_send_cpu = 0;
                                        sc->sc_bulk_send_next =
                                            TAILQ_FIRST(&state_list[sc->sc_bulk_send_cpu]);
                                }
                                sc->sc_bulk_terminator =
                                        sc->sc_bulk_send_next;
                                sc->sc_bulk_terminator_cpu =
                                        sc->sc_bulk_send_cpu;
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        kprintf("pfsync: received "
                                            "bulk update request\n");
                                pfsync_send_bus(sc, PFSYNC_BUS_START);
                                lwkt_reltoken(&pf_token);
                                callout_init(&sc->sc_bulk_tmo);
                                lwkt_gettoken(&pf_token);
                        } else {
                                st = pf_find_state_byid(&id_key);
                                if (st == NULL) {
                                        pfsyncstats.pfsyncs_badstate++;
                                        continue;
                                }
                                if (!st->sync_flags)
                                        pfsync_pack_state(PFSYNC_ACT_UPD,
                                            st, 0);
                        }
                }
                if (sc->sc_mbuf != NULL)
                        pfsync_sendout(sc);
                crit_exit();
                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) {
                        pfsyncstats.pfsyncs_badlen++;
                        return;
                }
                bus = (struct pfsync_state_bus *)(mp->m_data + offp);
                switch (bus->status) {
                case PFSYNC_BUS_START:
                        lwkt_reltoken(&pf_token);
                        callout_reset(&sc->sc_bulkfail_tmo,
                            pf_pool_limits[PF_LIMIT_STATES].limit /
                            (PFSYNC_BULKPACKETS * sc->sc_maxcount),
                            pfsync_bulkfail, LIST_FIRST(&pfsync_list));
                        lwkt_gettoken(&pf_token);
                        if (pf_status.debug >= PF_DEBUG_MISC)
                                kprintf("pfsync: received bulk "
                                    "update start\n");
                        break;
                case PFSYNC_BUS_END:
                        if (mycpu->gd_time_seconds - ntohl(bus->endtime) >=
                            sc->sc_ureq_sent) {
                                /* that's it, we're happy */
                                sc->sc_ureq_sent = 0;
                                sc->sc_bulk_tries = 0;
                                lwkt_reltoken(&pf_token);
                                callout_stop(&sc->sc_bulkfail_tmo);
                                lwkt_gettoken(&pf_token);
#ifdef CARP
                                if (!pfsync_sync_ok) {
                                        lwkt_reltoken(&pf_token);
                                        carp_group_demote_adj(&sc->sc_if, -1);
                                        lwkt_gettoken(&pf_token);
                                }
#endif
                                pfsync_sync_ok = 1;
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        kprintf("pfsync: received valid "
                                            "bulk update end\n");
                        } else {
                                if (pf_status.debug >= PF_DEBUG_MISC)
                                        kprintf("pfsync: received invalid "
                                            "bulk update end: bad timestamp\n");
                        }
                        break;
                }
                break;
        }

done:
        if (m)
                m_freem(m);
}

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

/* ARGSUSED */
int
pfsyncioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
{
        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 error;

        lwkt_gettoken(&pf_token);

        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) {
                        lwkt_reltoken(&pf_token);
                        return (EINVAL);
                }
                if (ifr->ifr_mtu > MCLBYTES)
                        ifr->ifr_mtu = MCLBYTES;
                crit_enter();
                if (ifr->ifr_mtu < ifp->if_mtu)
                        pfsync_sendout(sc);
                pfsync_setmtu(sc, ifr->ifr_mtu);
                crit_exit();
                break;
        case SIOCGETPFSYNC:
                bzero(&pfsyncr, 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;
                lwkt_reltoken(&pf_token);
                if ((error = copyout(&pfsyncr, ifr->ifr_data, sizeof(pfsyncr))))
                        return (error);
                lwkt_gettoken(&pf_token);
                break;
        case SIOCSETPFSYNC:
                error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT |
                                            __SYSCAP_NULLCRED);
                if (error) {
                        lwkt_reltoken(&pf_token);
                        return (error);
                }
                if ((error = copyin(ifr->ifr_data, &pfsyncr, sizeof(pfsyncr)))) {
                        lwkt_reltoken(&pf_token);
                        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) {
                        lwkt_reltoken(&pf_token);
                        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. */
                                crit_enter();
                                m_freem(sc->sc_mbuf_net);
                                sc->sc_mbuf_net = NULL;
                                sc->sc_statep_net.s = NULL;
                                crit_exit();
                        }
                        if (imo->imo_num_memberships > 0) {
                                pfsync_in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
                                imo->imo_multicast_ifp = NULL;
                        }
                        break;
                }

                /*
                 * XXX not that MPSAFE; pfsync needs serious rework
                 */
                ifnet_deserialize_all(ifp);
                ifnet_lock();
                sifp = ifunit(pfsyncr.pfsyncr_syncdev);
                ifnet_unlock();
                ifnet_serialize_all(ifp);

                if (sifp == NULL) {
                        lwkt_reltoken(&pf_token);
                        return (EINVAL);
                }

                crit_enter();
                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) {
                        pfsync_in_delmulti(imo->imo_membership[--imo->imo_num_memberships]);
                        imo->imo_multicast_ifp = NULL;
                }

                if (sc->sc_sync_ifp &&
                    sc->sc_sync_peer.s_addr == INADDR_PFSYNC_GROUP) {
                        if (!(sc->sc_sync_ifp->if_flags & IFF_MULTICAST)) {
                                sc->sc_sync_ifp = NULL;
                                lwkt_reltoken(&pf_token);
                                crit_exit();
                                return (EADDRNOTAVAIL);
                        }

                        if ((imo->imo_membership[0] =
                            pfsync_in_addmulti(sc->sc_sync_ifp)) == NULL) {
                                sc->sc_sync_ifp = NULL;
                                lwkt_reltoken(&pf_token);
                                crit_exit();
                                return (ENOBUFS);
                        }
                        imo->imo_num_memberships++;
                        imo->imo_multicast_ifp = 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 = mycpu->gd_time_seconds;
#ifdef CARP
                        if (pfsync_sync_ok)
                                carp_group_demote_adj(&sc->sc_if, 1);
#endif
                        pfsync_sync_ok = 0;
                        if (pf_status.debug >= PF_DEBUG_MISC)
                                kprintf("pfsync: requesting bulk update\n");
                        lwkt_reltoken(&pf_token);
                        callout_reset(&sc->sc_bulkfail_tmo, 5 * hz,
                            pfsync_bulkfail, LIST_FIRST(&pfsync_list));
                        lwkt_gettoken(&pf_token);
                        error = pfsync_request_update(NULL, NULL);
                        if (error == ENOMEM) {
                                lwkt_reltoken(&pf_token);
                                crit_exit();
                                return (ENOMEM);
                        }
                        pfsync_sendout(sc);
                }
                crit_exit();

                break;

        default:
                lwkt_reltoken(&pf_token);
                return (ENOTTY);
        }

        lwkt_reltoken(&pf_token);
        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;

        ASSERT_LWKT_TOKEN_HELD(&pf_token);

        MGETHDR(m, M_WAITOK, MT_DATA);

        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_WAITOK);
                m->m_data += rounddown2(MCLBYTES - len, sizeof(long));
        } else
                MH_ALIGN(m, len);

        m->m_pkthdr.rcvif = NULL;
        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;

        *sp = (void *)((char *)h + PFSYNC_HDRLEN);
        lwkt_reltoken(&pf_token);
        callout_reset(&sc->sc_tmo, hz, pfsync_timeout,
            LIST_FIRST(&pfsync_list));
        lwkt_gettoken(&pf_token);
        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;
        int 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);

        crit_enter();
        if (sc->sc_mbuf == NULL) {
                if ((sc->sc_mbuf = pfsync_get_mbuf(sc, action,
                    (void *)&sc->sc_statep.s)) == NULL) {
                        crit_exit();
                        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) {
                                crit_exit();
                                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++;
                                }
                        }
                }
        }

        st->pfsync_time = mycpu->gd_time_seconds;

        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++;
                bzero(sp, sizeof(*sp));

                pfsync_state_export(sp, st);

                if (flags & PFSYNC_FLAG_STALE)
                        sp->sync_flags |= PFSTATE_STALE;
        } else {
                pf_state_peer_hton(&st->src, &sp->src);
                pf_state_peer_hton(&st->dst, &sp->dst);

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

        /* 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) {
                                crit_exit();
                                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++;

                                bzero(up, sizeof(*up));
                                bcopy(&st->id, up->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++;

                        bzero(dp, sizeof(*dp));
                        bcopy(&st->id, dp->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);

        crit_exit();
        return (ret);
}

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++;
        bzero(rup, sizeof(*rup));
        if (up != NULL) {
                bcopy(up->id, rup->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 ret;

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

        crit_enter();
        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) {
                crit_exit();
                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));
        crit_exit();
        return (ret);
}

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

        crit_enter();
        pfsync_sendout(sc);
        crit_exit();
}

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(mycpu->gd_time_seconds - sc->sc_ureq_received);
                pfsync_sendout(sc);
        }
}

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

        ASSERT_LWKT_TOKEN_HELD(&pf_token);

        crit_enter();
        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;
        cpu = sc->sc_bulk_send_cpu;
        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 == NULL) {
                                if (++cpu >= ncpus)
                                        cpu = 0;
                                state = TAILQ_FIRST(&state_list[cpu]);
                        }
                } while (i < sc->sc_maxcount * PFSYNC_BULKPACKETS &&
                    cpu != sc->sc_bulk_terminator_cpu &&
                    state != sc->sc_bulk_terminator);

        if (state == NULL || (cpu == sc->sc_bulk_terminator_cpu &&
                              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;
                sc->sc_bulk_send_cpu = 0;
                sc->sc_bulk_terminator_cpu = 0;
                lwkt_reltoken(&pf_token);
                callout_stop(&sc->sc_bulk_tmo);
                lwkt_gettoken(&pf_token);
                if (pf_status.debug >= PF_DEBUG_MISC)
                        kprintf("pfsync: bulk update complete\n");
        } else {
                /* look again for more in a bit */
                lwkt_reltoken(&pf_token);
                callout_reset(&sc->sc_bulk_tmo, 1, pfsync_timeout,
                            LIST_FIRST(&pfsync_list));
                lwkt_gettoken(&pf_token);
                sc->sc_bulk_send_next = state;
                sc->sc_bulk_send_cpu = cpu;
        }
        if (sc->sc_mbuf != NULL)
                pfsync_sendout(sc);
        crit_exit();
}

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

        ASSERT_LWKT_TOKEN_HELD(&pf_token);

        if (sc->sc_bulk_tries++ < PFSYNC_MAX_BULKTRIES) {
                /* Try again in a bit */
                lwkt_reltoken(&pf_token);
                callout_reset(&sc->sc_bulkfail_tmo, 5 * hz, pfsync_bulkfail,
                    LIST_FIRST(&pfsync_list));
                lwkt_gettoken(&pf_token);
                crit_enter();
                error = pfsync_request_update(NULL, NULL);
                if (error == ENOMEM) {
                        if (pf_status.debug >= PF_DEBUG_MISC)
                                kprintf("pfsync: cannot allocate mbufs for "
                                    "bulk update\n");
                } else
                        pfsync_sendout(sc);
                crit_exit();
        } else {
                /* Pretend like the transfer was ok */
                sc->sc_ureq_sent = 0;
                sc->sc_bulk_tries = 0;
#ifdef CARP
                if (!pfsync_sync_ok)
                        carp_group_demote_adj(&sc->sc_if, -1);
#endif
                pfsync_sync_ok = 1;
                if (pf_status.debug >= PF_DEBUG_MISC)
                        kprintf("pfsync: failed to receive "
                            "bulk update status\n");
                lwkt_reltoken(&pf_token);
                callout_stop(&sc->sc_bulkfail_tmo);
                lwkt_gettoken(&pf_token);
        }
}

static void
pfsync_sendout_handler(netmsg_t nmsg)
{
        struct netmsg_genpkt *msg = (struct netmsg_genpkt *)nmsg;

        pfsync_sendout_mbuf(msg->arg1, msg->m);
}

int
pfsync_sendout(struct pfsync_softc *sc)
{
#if NBPF > 0
        struct ifnet *ifp = &sc->sc_if;
#endif
        struct mbuf *m;
        struct netmsg_genpkt *msg;

        ASSERT_LWKT_TOKEN_HELD(&pf_token);

        lwkt_reltoken(&pf_token);
        callout_stop(&sc->sc_tmo);
        lwkt_gettoken(&pf_token);

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

#if NBPF > 0
        if (ifp->if_bpf) {
                bpf_gettoken();
                if (ifp->if_bpf)
                        bpf_mtap(ifp->if_bpf, m);
                bpf_reltoken();
        }
#endif

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

        msg = &m->m_hdr.mh_genmsg;
        netmsg_init(&msg->base, NULL, &netisr_apanic_rport, 0,
            pfsync_sendout_handler);
        msg->m = m;
        msg->arg1 = sc;
        netisr_sendmsg(&msg->base, 0);

        return (0);
}

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_WAITOK);
                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 = htons(ip_randomid());
                ip->ip_off = htons(IP_DF);
                ip->ip_ttl = PFSYNC_DFLTTL;
                ip->ip_p = IPPROTO_PFSYNC;
                ip->ip_sum = 0;

                bzero(&sa, 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;

                pfsyncstats.pfsyncs_opackets++;

                if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL))
                        pfsyncstats.pfsyncs_oerrors++;
        } else
                m_freem(m);

        return (0);
}

static int
pfsync_modevent(module_t mod, int type, void *data)
{
        int error = 0;

        struct pfsync_softc     *pfs_if, *tmp;

        lwkt_gettoken(&pf_token);

        switch (type) {
        case MOD_LOAD:
                LIST_INIT(&pfsync_list);
                lwkt_reltoken(&pf_token);
                if_clone_attach(&pfsync_cloner);
                lwkt_gettoken(&pf_token);
                /* Override the function pointer for pf_ioctl.c */
                break;

        case MOD_UNLOAD:
                lwkt_reltoken(&pf_token);
                if_clone_detach(&pfsync_cloner);
                lwkt_gettoken(&pf_token);
                LIST_FOREACH_MUTABLE(pfs_if, &pfsync_list, sc_next, tmp) {
                        pfsync_clone_destroy(&pfs_if->sc_if);
                }
                break;

        default:
                error = EINVAL;
                break;
        }

        lwkt_reltoken(&pf_token);
        return error;
}

static moduledata_t pfsync_mod = {
        "pfsync",
        pfsync_modevent,
        0
};

#define PFSYNC_MODVER 44

DECLARE_MODULE(pfsync, pfsync_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
MODULE_VERSION(pfsync, PFSYNC_MODVER);
MODULE_DEPEND(pfsync, pf, PF_MODVER, PF_MODVER, PF_MODVER);

static void
pfsync_in_addmulti_dispatch(netmsg_t nmsg)
{
        struct lwkt_msg *lmsg = &nmsg->lmsg;
        struct ifnet *ifp = lmsg->u.ms_resultp;
        struct in_addr addr;

        addr.s_addr = INADDR_PFSYNC_GROUP;
        lmsg->u.ms_resultp = in_addmulti(&addr, ifp);

        lwkt_replymsg(lmsg, 0);
}

static struct in_multi *
pfsync_in_addmulti(struct ifnet *ifp)
{
        struct netmsg_base nmsg;
        struct lwkt_msg *lmsg = &nmsg.lmsg;

        netmsg_init(&nmsg, NULL, &curthread->td_msgport, 0,
            pfsync_in_addmulti_dispatch);
        lmsg->u.ms_resultp = ifp;

        lwkt_domsg(netisr_cpuport(0), lmsg, 0);
        return lmsg->u.ms_resultp;
}

static void
pfsync_in_delmulti_dispatch(netmsg_t nmsg)
{
        struct lwkt_msg *lmsg = &nmsg->lmsg;

        in_delmulti(lmsg->u.ms_resultp);
        lwkt_replymsg(lmsg, 0);
}

static void
pfsync_in_delmulti(struct in_multi *inm)
{
        struct netmsg_base nmsg;
        struct lwkt_msg *lmsg = &nmsg.lmsg;

        netmsg_init(&nmsg, NULL, &curthread->td_msgport, 0,
            pfsync_in_delmulti_dispatch);
        lmsg->u.ms_resultp = inm;

        lwkt_domsg(netisr_cpuport(0), lmsg, 0);
}