/* $OpenBSD: if_pfsync.c,v 1.9 2003/12/15 07:28:25 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 "bpfilter.h" #include "pfsync.h" #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #include #include #include #include #endif #ifdef INET6 #ifndef INET #include #endif #include #endif /* INET6 */ #include #include #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 struct pfsync_softc pfsyncif; struct pfsyncstats pfsyncstats; void pfsyncattach(int); void pfsync_setmtu(struct pfsync_softc *, int); int pfsync_insert_net_state(struct pfsync_state *); int pfsyncoutput(struct ifnet *, struct mbuf *, struct sockaddr *, struct rtentry *); int pfsyncioctl(struct ifnet *, u_long, caddr_t); void pfsyncstart(struct ifnet *); struct mbuf *pfsync_get_mbuf(struct pfsync_softc *, u_int8_t, void **); int pfsync_sendout(struct pfsync_softc *sc); void pfsync_timeout(void *); extern int ifqmaxlen; extern struct timeval time; void pfsyncattach(int npfsync) { struct ifnet *ifp; bzero(&pfsyncif, sizeof(pfsyncif)); pfsyncif.sc_mbuf = NULL; pfsyncif.sc_mbuf_net = NULL; pfsyncif.sc_sp.s = NULL; pfsyncif.sc_sp_net.s = NULL; pfsyncif.sc_maxupdates = 128; ifp = &pfsyncif.sc_if; strlcpy(ifp->if_xname, "pfsync0", sizeof ifp->if_xname); 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; ifp->if_baudrate = IF_Mbps(100); pfsync_setmtu(&pfsyncif, MCLBYTES); timeout_set(&pfsyncif.sc_tmo, pfsync_timeout, &pfsyncif); if_attach(ifp); if_alloc_sadl(ifp); #if NBPFILTER > 0 bpfattach(&pfsyncif.sc_if.if_bpf, ifp, DLT_PFSYNC, PFSYNC_HDRLEN); #endif } /* * Start output on the pfsync interface. */ void pfsyncstart(struct ifnet *ifp) { struct mbuf *m; int s; for (;;) { s = splimp(); IF_DROP(&ifp->if_snd); IF_DEQUEUE(&ifp->if_snd, m); splx(s); if (m == NULL) return; else m_freem(m); } } int pfsync_insert_net_state(struct pfsync_state *sp) { struct pf_state *st = NULL; struct pf_rule *r = NULL; u_long secs; if (sp->creatorid == 0 && pf_status.debug >= PF_DEBUG_MISC) { printf("pfsync_insert_net_state: invalid creator id:" "id: %016llx creatorid: %08x\n", betoh64(sp->id), ntohl(sp->creatorid)); return (EINVAL); } /* * Just use the default rule until we have infrastructure to find the * best matching rule. */ r = &pf_default_rule; if (!r->max_states || r->states < r->max_states) st = pool_get(&pf_state_pl, PR_NOWAIT); if (st == NULL) return (ENOMEM); bzero(st, sizeof(*st)); st->rule.ptr = r; /* XXX get pointers to nat_rule and anchor */ /* fill in the rest of the state entry */ pf_state_host_ntoh(&sp->lan, &st->lan); pf_state_host_ntoh(&sp->gwy, &st->gwy); pf_state_host_ntoh(&sp->ext, &st->ext); pf_state_peer_ntoh(&sp->src, &st->src); pf_state_peer_ntoh(&sp->dst, &st->dst); bcopy(&sp->rt_addr, &st->rt_addr, sizeof(st->rt_addr)); secs = time.tv_sec; st->creation = secs + ntohl(sp->creation); st->af = sp->af; st->proto = sp->proto; st->direction = sp->direction; st->log = sp->log; st->allow_opts = sp->allow_opts; st->id = sp->id; st->creatorid = sp->creatorid; st->sync_flags = sp->sync_flags | PFSTATE_FROMSYNC; secs = time.tv_sec; if (sp->expire) st->expire = 0; else st->expire = ntohl(sp->expire) + secs; if (pf_insert_state(st)) { pool_put(&pf_state_pl, st); return (EINVAL); } return (0); } 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, key; struct pfsync_state *sp; struct pfsync_state_upd *up; struct pfsync_state_del *dp; struct pfsync_state_clr *cp; struct mbuf *mp; int iplen, action, error, i, s, count, offp; u_long secs; pfsyncstats.pfsyncs_ipackets++; /* verify that we have a sync interface configured */ if (!sc->sc_sync_ifp) 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 = (void *)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; } switch (action) { case PFSYNC_ACT_CLR: { u_int32_t creatorid; if ((mp = m_pulldown(m, iplen + sizeof(*ph), sizeof(*cp), &offp)) == NULL) { pfsyncstats.pfsyncs_badlen++; return; } s = splsoftnet(); cp = (void *)((char *)mp->m_data + iplen + PFSYNC_HDRLEN); creatorid = cp->creatorid; RB_FOREACH(st, pf_state_tree_ext_gwy, &tree_ext_gwy) { if (st->creatorid == creatorid) st->timeout = PFTM_PURGE; } pf_purge_expired_states(); splx(s); break; } case PFSYNC_ACT_INS: if ((mp = m_pulldown(m, iplen + sizeof(*ph), count * sizeof(*sp), &offp)) == NULL) { pfsyncstats.pfsyncs_badlen++; return; } s = splsoftnet(); for (i = 0, sp = (void *)((char *)mp->m_data + iplen + PFSYNC_HDRLEN); i < count; i++, sp++) { if ((error = pfsync_insert_net_state(sp))) { if (error == ENOMEM) { splx(s); goto done; } continue; } } splx(s); break; /* * It's not strictly necessary for us to support the "uncompressed" * update and delete actions, but it's relatively simple for us to do. */ case PFSYNC_ACT_UPD: if ((mp = m_pulldown(m, iplen + sizeof(*ph), count * sizeof(*sp), &offp)) == NULL) { pfsyncstats.pfsyncs_badlen++; return; } s = splsoftnet(); for (i = 0, sp = (void *)((char *)mp->m_data + iplen + PFSYNC_HDRLEN); i < count; i++, sp++) { key.id = sp->id; key.creatorid = sp->creatorid; st = pf_find_state(&key, PF_ID); if (st == NULL) { /* try to do an insert? */ pfsyncstats.pfsyncs_badstate++; continue; } pf_state_peer_ntoh(&sp->src, &st->src); pf_state_peer_ntoh(&sp->dst, &st->dst); secs = time.tv_sec; if (sp->expire) st->expire = 0; else st->expire = ntohl(sp->expire) + secs; } splx(s); break; case PFSYNC_ACT_DEL: if ((mp = m_pulldown(m, iplen + sizeof(*ph), count * sizeof(*sp), &offp)) == NULL) { pfsyncstats.pfsyncs_badlen++; return; } s = splsoftnet(); for (i = 0, sp = (void *)((char *)mp->m_data + iplen + PFSYNC_HDRLEN); i < count; i++, sp++) { key.id = sp->id; key.creatorid = sp->creatorid; st = pf_find_state(&key, PF_ID); if (st == NULL) { pfsyncstats.pfsyncs_badstate++; continue; } /* * XXX * pf_purge_expired_states() is expensive, * we really want to purge the state directly. */ st->timeout = PFTM_PURGE; st->sync_flags |= PFSTATE_FROMSYNC; } pf_purge_expired_states(); splx(s); break; case PFSYNC_ACT_UPD_C: if ((mp = m_pulldown(m, iplen + sizeof(*ph), count * sizeof(*up), &offp)) == NULL) { pfsyncstats.pfsyncs_badlen++; return; } s = splsoftnet(); for (i = 0, up = (void *)((char *)mp->m_data + iplen + PFSYNC_HDRLEN); i < count; i++, up++) { key.id = up->id; key.creatorid = up->creatorid; st = pf_find_state(&key, PF_ID); if (st == NULL) { /* send out a request for a full state? */ pfsyncstats.pfsyncs_badstate++; continue; } pf_state_peer_ntoh(&up->src, &st->src); pf_state_peer_ntoh(&up->dst, &st->dst); secs = time.tv_sec; if (up->expire) st->expire = 0; else st->expire = ntohl(up->expire) + secs; } splx(s); break; case PFSYNC_ACT_DEL_C: if ((mp = m_pulldown(m, iplen + sizeof(*ph), count * sizeof(*dp), &offp)) == NULL) { pfsyncstats.pfsyncs_badlen++; return; } s = splsoftnet(); for (i = 0, dp = (void *)((char *)mp->m_data + iplen + PFSYNC_HDRLEN); i < count; i++, dp++) { key.id = dp->id; key.creatorid = dp->creatorid; st = pf_find_state(&key, PF_ID); if (st == NULL) { pfsyncstats.pfsyncs_badstate++; continue; } /* * XXX * pf_purge_expired_states() is expensive, * we really want to purge the state directly. */ st->timeout = PFTM_PURGE; st->sync_flags |= PFSTATE_FROMSYNC; } pf_purge_expired_states(); splx(s); break; case PFSYNC_ACT_INS_F: case PFSYNC_ACT_DEL_F: /* not implemented */ 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 proc *p = curproc; 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: bzero(&pfsyncr, sizeof(pfsyncr)); if (sc->sc_sync_ifp) strlcpy(pfsyncr.pfsyncr_syncif, sc->sc_sync_ifp->if_xname, IFNAMSIZ); pfsyncr.pfsyncr_maxupdates = sc->sc_maxupdates; if ((error = copyout(&pfsyncr, ifr->ifr_data, sizeof(pfsyncr)))) return (error); break; case SIOCSETPFSYNC: if ((error = suser(p, p->p_acflag)) != 0) return (error); if ((error = copyin(ifr->ifr_data, &pfsyncr, sizeof(pfsyncr)))) return (error); if (pfsyncr.pfsyncr_maxupdates > 255) return (EINVAL); sc->sc_maxupdates = pfsyncr.pfsyncr_maxupdates; if (pfsyncr.pfsyncr_syncif[0] == 0) { sc->sc_sync_ifp = NULL; break; } if ((sifp = ifunit(pfsyncr.pfsyncr_syncif)) == NULL) return (EINVAL); else if (sifp == sc->sc_sync_ifp) break; 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_ifp = NULL; } if (sc->sc_sync_ifp) { struct in_addr addr; addr.s_addr = INADDR_PFSYNC_GROUP; if ((imo->imo_membership[0] = in_addmulti(&addr, sc->sc_sync_ifp)) == NULL) { splx(s); 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; } splx(s); break; default: return (ENOTTY); } 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) { extern int hz; struct pfsync_header *h; struct mbuf *m; int len; MGETHDR(m, M_DONTWAIT, MT_DATA); if (m == NULL) { sc->sc_if.if_oerrors++; return (NULL); } switch (action) { 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_CLR: len = sizeof(struct pfsync_header) + sizeof(struct pfsync_state_clr); 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); sc->sc_if.if_oerrors++; return (NULL); } m->m_data += (MCLBYTES - len) &~ (sizeof(long) - 1); } 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); timeout_add(&sc->sc_tmo, hz); return (m); } int pfsync_pack_state(u_int8_t action, struct pf_state *st) { struct ifnet *ifp = &pfsyncif.sc_if; struct pfsync_softc *sc = ifp->if_softc; 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_rule *r; u_long secs; int s, ret = 0; u_int8_t i = 255, newaction = 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_sp.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_sp.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 (usp->id == st->id && usp->creatorid == st->creatorid) { sp = usp; break; } usp++; } } } } secs = time.tv_sec; if (sp == NULL) { /* not a "duplicate" update */ sp = sc->sc_sp.s++; sc->sc_mbuf->m_pkthdr.len = sc->sc_mbuf->m_len += sizeof(struct pfsync_state); h->count++; bzero(sp, sizeof(*sp)); sp->id = st->id; sp->creatorid = st->creatorid; pf_state_host_hton(&st->lan, &sp->lan); pf_state_host_hton(&st->gwy, &sp->gwy); pf_state_host_hton(&st->ext, &sp->ext); bcopy(&st->rt_addr, &sp->rt_addr, sizeof(sp->rt_addr)); sp->creation = htonl(secs - st->creation); sp->packets[0] = htonl(st->packets[0]); sp->packets[1] = htonl(st->packets[1]); sp->bytes[0] = htonl(st->bytes[0]); sp->bytes[1] = htonl(st->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 = st->af; sp->proto = st->proto; sp->direction = st->direction; sp->log = st->log; sp->allow_opts = st->allow_opts; sp->sync_flags = st->sync_flags & PFSTATE_NOSYNC; } else sp->updates++; 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) { 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_sp_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 < h->count) { 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_sp_net.u++; bzero(up, sizeof(*up)); up->id = st->id; up->creatorid = st->creatorid; } 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_sp_net.d++; h_net->count++; bzero(dp, sizeof(*dp)); dp->id = st->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); } int pfsync_clear_states(u_int32_t creatorid) { struct ifnet *ifp = &pfsyncif.sc_if; struct pfsync_softc *sc = ifp->if_softc; struct pfsync_state_clr *cp; int s, ret; s = splnet(); if (sc->sc_mbuf != NULL) { pfsync_sendout(sc); } if ((sc->sc_mbuf = pfsync_get_mbuf(sc, PFSYNC_ACT_CLR, (void *)&sc->sc_sp.c)) == NULL) { splx(s); return (ENOMEM); } sc->sc_mbuf->m_pkthdr.len = sc->sc_mbuf->m_len += sizeof(*cp); cp = sc->sc_sp.c; cp->creatorid = creatorid; 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); } int pfsync_sendout(sc) struct pfsync_softc *sc; { struct ifnet *ifp = &sc->sc_if; struct mbuf *m = sc->sc_mbuf; timeout_del(&sc->sc_tmo); sc->sc_mbuf = NULL; sc->sc_sp.s = NULL; #if NBPFILTER > 0 if (ifp->if_bpf) bpf_mtap(ifp->if_bpf, m); #endif if (sc->sc_mbuf_net) { m_freem(m); m = sc->sc_mbuf_net; sc->sc_mbuf_net = NULL; sc->sc_sp_net.s = NULL; } if (sc->sc_sync_ifp) { struct ip *ip; struct ifaddr *ifa; struct sockaddr sa; M_PREPEND(m, sizeof(struct ip), M_DONTWAIT); if (m == NULL) { pfsyncstats.pfsyncs_onomem++; return (0); } m->m_flags |= M_MCAST; 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)); sa.sa_family = AF_INET; ifa = ifaof_ifpforaddr(&sa, sc->sc_sync_ifp); if (ifa == NULL) return (0); ip->ip_src.s_addr = ifatoia(ifa)->ia_addr.sin_addr.s_addr; ip->ip_dst.s_addr = INADDR_PFSYNC_GROUP; pfsyncstats.pfsyncs_opackets++; if (ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL)) pfsyncstats.pfsyncs_oerrors++; } else { m_freem(m); } return (0); }