/* $OpenBSD: ip_output.c,v 1.306 2015/11/11 10:23:23 mpi Exp $ */ /* $NetBSD: ip_output.c,v 1.28 1996/02/13 23:43:07 christos Exp $ */ /* * Copyright (c) 1982, 1986, 1988, 1990, 1993 * The Regents of the University of California. 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. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ip_output.c 8.3 (Berkeley) 1/21/94 */ #include "pf.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if NPF > 0 #include #endif #ifdef IPSEC #ifdef ENCDEBUG #define DPRINTF(x) do { if (encdebug) printf x ; } while (0) #else #define DPRINTF(x) #endif #endif /* IPSEC */ struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); void ip_mloopback(struct ifnet *, struct mbuf *, struct sockaddr_in *); static __inline u_int16_t __attribute__((__unused__)) in_cksum_phdr(u_int32_t, u_int32_t, u_int32_t); void in_delayed_cksum(struct mbuf *); /* * IP output. The packet in mbuf chain m contains a skeletal IP * header (with len, off, ttl, proto, tos, src, dst). * The mbuf chain containing the packet will be freed. * The mbuf opt, if present, will not be freed. */ int ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro, int flags, struct ip_moptions *imo, struct inpcb *inp, u_int32_t ipsecflowinfo) { struct ip *ip; struct ifnet *ifp = NULL; struct mbuf *m = m0; int hlen = sizeof (struct ip); int len, error = 0; struct route iproute; struct sockaddr_in *dst; struct in_ifaddr *ia; u_int8_t sproto = 0; u_long mtu; #ifdef IPSEC u_int32_t icmp_mtu = 0; union sockaddr_union sdst; u_int32_t sspi; struct m_tag *mtag; struct tdb_ident *tdbi; struct tdb *tdb; #if NPF > 0 struct ifnet *encif; #endif #endif /* IPSEC */ #ifdef IPSEC if (inp && (inp->inp_flags & INP_IPV6) != 0) panic("ip_output: IPv6 pcb is passed"); #endif /* IPSEC */ #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("ip_output no HDR"); #endif if (opt) { m = ip_insertoptions(m, opt, &len); hlen = len; } ip = mtod(m, struct ip *); /* * Fill in IP header. */ if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) { ip->ip_v = IPVERSION; ip->ip_off &= htons(IP_DF); ip->ip_id = htons(ip_randomid()); ip->ip_hl = hlen >> 2; ipstat.ips_localout++; } else { hlen = ip->ip_hl << 2; } /* * We should not send traffic to 0/8 say both Stevens and RFCs * 5735 section 3 and 1122 sections 3.2.1.3 and 3.3.6. */ if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == 0) { error = ENETUNREACH; goto bad; } #if NPF > 0 reroute: #endif /* * Do a route lookup now in case we need the source address to * do an SPD lookup in IPsec; for most packets, the source address * is set at a higher level protocol. ICMPs and other packets * though (e.g., traceroute) have a source address of zeroes. */ if (ro == NULL) { ro = &iproute; memset(ro, 0, sizeof(*ro)); } dst = satosin(&ro->ro_dst); /* * If there is a cached route, check that it is to the same * destination and is still up. If not, free it and try again. */ if (!rtisvalid(ro->ro_rt) || dst->sin_addr.s_addr != ip->ip_dst.s_addr || ro->ro_tableid != m->m_pkthdr.ph_rtableid) { rtfree(ro->ro_rt); ro->ro_rt = NULL; } if (ro->ro_rt == NULL) { dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = ip->ip_dst; ro->ro_tableid = m->m_pkthdr.ph_rtableid; } if ((IN_MULTICAST(ip->ip_dst.s_addr) || (ip->ip_dst.s_addr == INADDR_BROADCAST)) && imo != NULL && (ifp = if_get(imo->imo_ifidx)) != NULL) { mtu = ifp->if_mtu; IFP_TO_IA(ifp, ia); } else { if (ro->ro_rt == NULL) ro->ro_rt = rtalloc_mpath(&ro->ro_dst, &ip->ip_src.s_addr, ro->ro_tableid); if (ro->ro_rt == NULL) { ipstat.ips_noroute++; error = EHOSTUNREACH; goto bad; } ia = ifatoia(ro->ro_rt->rt_ifa); if (ISSET(ro->ro_rt->rt_flags, RTF_LOCAL)) ifp = if_get(lo0ifidx); else ifp = if_get(ro->ro_rt->rt_ifidx); if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) mtu = ifp->if_mtu; if (ro->ro_rt->rt_flags & RTF_GATEWAY) dst = satosin(ro->ro_rt->rt_gateway); } /* Set the source IP address */ if (ip->ip_src.s_addr == INADDR_ANY && ia) ip->ip_src = ia->ia_addr.sin_addr; #ifdef IPSEC if (!ipsec_in_use && inp == NULL) goto done_spd; /* Do we have any pending SAs to apply ? */ tdb = ipsp_spd_lookup(m, AF_INET, hlen, &error, IPSP_DIRECTION_OUT, NULL, inp, ipsecflowinfo); if (tdb == NULL) { if (error == 0) { /* * No IPsec processing required, we'll just send the * packet out. */ sproto = 0; /* Fall through to routing/multicast handling */ } else { /* * -EINVAL is used to indicate that the packet should * be silently dropped, typically because we've asked * key management for an SA. */ if (error == -EINVAL) /* Should silently drop packet */ error = 0; m_freem(m); goto done; } } else { /* Loop detection */ for (mtag = m_tag_first(m); mtag != NULL; mtag = m_tag_next(m, mtag)) { if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE) continue; tdbi = (struct tdb_ident *)(mtag + 1); if (tdbi->spi == tdb->tdb_spi && tdbi->proto == tdb->tdb_sproto && tdbi->rdomain == tdb->tdb_rdomain && !memcmp(&tdbi->dst, &tdb->tdb_dst, sizeof(union sockaddr_union))) { sproto = 0; /* mark as no-IPsec-needed */ goto done_spd; } } /* We need to do IPsec */ bcopy(&tdb->tdb_dst, &sdst, sizeof(sdst)); sspi = tdb->tdb_spi; sproto = tdb->tdb_sproto; /* * If it needs TCP/UDP hardware-checksumming, do the * computation now. */ in_proto_cksum_out(m, NULL); /* If it's not a multicast packet, try to fast-path */ if (!IN_MULTICAST(ip->ip_dst.s_addr)) { goto sendit; } } /* Fall through to the routing/multicast handling code */ done_spd: #endif /* IPSEC */ if (IN_MULTICAST(ip->ip_dst.s_addr) || (ip->ip_dst.s_addr == INADDR_BROADCAST)) { struct in_multi *inm; m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ? M_BCAST : M_MCAST; /* * IP destination address is multicast. Make sure "dst" * still points to the address in "ro". (It may have been * changed to point to a gateway address, above.) */ dst = satosin(&ro->ro_dst); /* * See if the caller provided any multicast options */ if (imo != NULL) ip->ip_ttl = imo->imo_ttl; else ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL; /* * if we don't know the outgoing ifp yet, we can't generate * output */ if (!ifp) { ipstat.ips_noroute++; error = EHOSTUNREACH; goto bad; } /* * Confirm that the outgoing interface supports multicast, * but only if the packet actually is going out on that * interface (i.e., no IPsec is applied). */ if ((((m->m_flags & M_MCAST) && (ifp->if_flags & IFF_MULTICAST) == 0) || ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_BROADCAST) == 0)) && (sproto == 0)) { ipstat.ips_noroute++; error = ENETUNREACH; goto bad; } /* * If source address not specified yet, use address * of outgoing interface. */ if (ip->ip_src.s_addr == INADDR_ANY) { IFP_TO_IA(ifp, ia); if (ia != NULL) ip->ip_src = ia->ia_addr.sin_addr; } IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); if (inm != NULL && (imo == NULL || imo->imo_loop)) { /* * If we belong to the destination multicast group * on the outgoing interface, and the caller did not * forbid loopback, loop back a copy. * Can't defer TCP/UDP checksumming, do the * computation now. */ in_proto_cksum_out(m, NULL); ip_mloopback(ifp, m, dst); } #ifdef MROUTING else { /* * If we are acting as a multicast router, perform * multicast forwarding as if the packet had just * arrived on the interface to which we are about * to send. The multicast forwarding function * recursively calls this function, using the * IP_FORWARDING flag to prevent infinite recursion. * * Multicasts that are looped back by ip_mloopback(), * above, will be forwarded by the ip_input() routine, * if necessary. */ if (ipmforwarding && ip_mrouter && (flags & IP_FORWARDING) == 0) { if (ip_mforward(m, ifp) != 0) { m_freem(m); goto done; } } } #endif /* * Multicasts with a time-to-live of zero may be looped- * back, above, but must not be transmitted on a network. * Also, multicasts addressed to the loopback interface * are not sent -- the above call to ip_mloopback() will * loop back a copy if this host actually belongs to the * destination group on the loopback interface. */ if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) { m_freem(m); goto done; } goto sendit; } /* * Look for broadcast address and verify user is allowed to send * such a packet; if the packet is going in an IPsec tunnel, skip * this check. */ if ((sproto == 0) && ((dst->sin_addr.s_addr == INADDR_BROADCAST) || (ro && ro->ro_rt && ISSET(ro->ro_rt->rt_flags, RTF_BROADCAST)))) { if ((ifp->if_flags & IFF_BROADCAST) == 0) { error = EADDRNOTAVAIL; goto bad; } if ((flags & IP_ALLOWBROADCAST) == 0) { error = EACCES; goto bad; } /* Don't allow broadcast messages to be fragmented */ if (ntohs(ip->ip_len) > ifp->if_mtu) { error = EMSGSIZE; goto bad; } m->m_flags |= M_BCAST; } else m->m_flags &= ~M_BCAST; sendit: /* * If we're doing Path MTU discovery, we need to set DF unless * the route's MTU is locked. */ if ((flags & IP_MTUDISC) && ro && ro->ro_rt && (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) ip->ip_off |= htons(IP_DF); #ifdef IPSEC /* * Check if the packet needs encapsulation. */ if (sproto != 0) { tdb = gettdb(rtable_l2(m->m_pkthdr.ph_rtableid), sspi, &sdst, sproto); if (tdb == NULL) { DPRINTF(("ip_output: unknown TDB")); error = EHOSTUNREACH; m_freem(m); goto done; } /* * Packet filter */ #if NPF > 0 if ((encif = enc_getif(tdb->tdb_rdomain, tdb->tdb_tap)) == NULL || pf_test(AF_INET, PF_OUT, encif, &m) != PF_PASS) { error = EACCES; m_freem(m); goto done; } if (m == NULL) { goto done; } ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; /* * PF_TAG_REROUTE handling or not... * Packet is entering IPsec so the routing is * already overruled by the IPsec policy. * Until now the change was not reconsidered. * What's the behaviour? */ in_proto_cksum_out(m, encif); #endif /* Check if we are allowed to fragment */ if (ip_mtudisc && (ip->ip_off & htons(IP_DF)) && tdb->tdb_mtu && ntohs(ip->ip_len) > tdb->tdb_mtu && tdb->tdb_mtutimeout > time_second) { struct rtentry *rt = NULL; int rt_mtucloned = 0; int transportmode = 0; transportmode = (tdb->tdb_dst.sa.sa_family == AF_INET) && (tdb->tdb_dst.sin.sin_addr.s_addr == ip->ip_dst.s_addr); icmp_mtu = tdb->tdb_mtu; /* Find a host route to store the mtu in */ if (ro != NULL) rt = ro->ro_rt; /* but don't add a PMTU route for transport mode SAs */ if (transportmode) rt = NULL; else if (rt == NULL || (rt->rt_flags & RTF_HOST) == 0) { rt = icmp_mtudisc_clone(ip->ip_dst, m->m_pkthdr.ph_rtableid); rt_mtucloned = 1; } DPRINTF(("ip_output: spi %08x mtu %d rt %p cloned %d\n", ntohl(tdb->tdb_spi), icmp_mtu, rt, rt_mtucloned)); if (rt != NULL) { rt->rt_rmx.rmx_mtu = icmp_mtu; if (ro && ro->ro_rt != NULL) { rtfree(ro->ro_rt); ro->ro_rt = rtalloc(&ro->ro_dst, RT_REPORT|RT_RESOLVE, m->m_pkthdr.ph_rtableid); } if (rt_mtucloned) rtfree(rt); } error = EMSGSIZE; goto bad; } /* * Clear these -- they'll be set in the recursive invocation * as needed. */ m->m_flags &= ~(M_MCAST | M_BCAST); /* Callee frees mbuf */ error = ipsp_process_packet(m, tdb, AF_INET, 0); if_put(ifp); return error; /* Nothing more to be done */ } #endif /* IPSEC */ /* * Packet filter */ #if NPF > 0 if (pf_test(AF_INET, PF_OUT, ifp, &m) != PF_PASS) { error = EHOSTUNREACH; m_freem(m); goto done; } if (m == NULL) goto done; ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; if ((m->m_pkthdr.pf.flags & (PF_TAG_REROUTE | PF_TAG_GENERATED)) == (PF_TAG_REROUTE | PF_TAG_GENERATED)) /* already rerun the route lookup, go on */ m->m_pkthdr.pf.flags &= ~(PF_TAG_GENERATED | PF_TAG_REROUTE); else if (m->m_pkthdr.pf.flags & PF_TAG_REROUTE) { /* tag as generated to skip over pf_test on rerun */ m->m_pkthdr.pf.flags |= PF_TAG_GENERATED; ro = NULL; if_put(ifp); /* drop reference since target changed */ goto reroute; } #endif in_proto_cksum_out(m, ifp); #ifdef IPSEC if (ipsec_in_use && (flags & IP_FORWARDING) && (ipforwarding == 2) && (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) == NULL)) { error = EHOSTUNREACH; m_freem(m); goto done; } #endif /* * If small enough for interface, can just send directly. */ if (ntohs(ip->ip_len) <= mtu) { ip->ip_sum = 0; if ((ifp->if_capabilities & IFCAP_CSUM_IPv4) && (ifp->if_bridgeport == NULL)) m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; else { ipstat.ips_outswcsum++; ip->ip_sum = in_cksum(m, hlen); } error = ifp->if_output(ifp, m, sintosa(dst), ro->ro_rt); goto done; } /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. */ if (ip->ip_off & htons(IP_DF)) { #ifdef IPSEC icmp_mtu = ifp->if_mtu; #endif error = EMSGSIZE; /* * This case can happen if the user changed the MTU * of an interface after enabling IP on it. Because * most netifs don't keep track of routes pointing to * them, there is no way for one to update all its * routes when the MTU is changed. */ if (rtisvalid(ro->ro_rt) && ISSET(ro->ro_rt->rt_flags, RTF_HOST) && !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) && (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) { ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu; } ipstat.ips_cantfrag++; goto bad; } error = ip_fragment(m, ifp, mtu); if (error) { m = m0 = NULL; goto bad; } for (; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = 0; if (error == 0) error = ifp->if_output(ifp, m, sintosa(dst), ro->ro_rt); else m_freem(m); } if (error == 0) ipstat.ips_fragmented++; done: if (ro == &iproute && ro->ro_rt) rtfree(ro->ro_rt); if_put(ifp); return (error); bad: #ifdef IPSEC if (error == EMSGSIZE && ip_mtudisc && icmp_mtu != 0 && m != NULL) ipsec_adjust_mtu(m, icmp_mtu); #endif m_freem(m0); goto done; } int ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu) { struct ip *ip, *mhip; struct mbuf *m0; int len, hlen, off; int mhlen, firstlen; struct mbuf **mnext; int fragments = 0; int error = 0; ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; len = (mtu - hlen) &~ 7; if (len < 8) { m_freem(m); return (EMSGSIZE); } /* * If we are doing fragmentation, we can't defer TCP/UDP * checksumming; compute the checksum and clear the flag. */ in_proto_cksum_out(m, NULL); firstlen = len; mnext = &m->m_nextpkt; /* * Loop through length of segment after first fragment, * make new header and copy data of each part and link onto chain. */ m0 = m; mhlen = sizeof (struct ip); for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { MGETHDR(m, M_DONTWAIT, MT_HEADER); if (m == NULL) { ipstat.ips_odropped++; error = ENOBUFS; goto sendorfree; } *mnext = m; mnext = &m->m_nextpkt; m->m_data += max_linkhdr; mhip = mtod(m, struct ip *); *mhip = *ip; /* we must inherit MCAST and BCAST flags and routing table */ m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); m->m_pkthdr.ph_rtableid = m0->m_pkthdr.ph_rtableid; if (hlen > sizeof (struct ip)) { mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); mhip->ip_hl = mhlen >> 2; } m->m_len = mhlen; mhip->ip_off = ((off - hlen) >> 3) + (ntohs(ip->ip_off) & ~IP_MF); if (ip->ip_off & htons(IP_MF)) mhip->ip_off |= IP_MF; if (off + len >= ntohs(ip->ip_len)) len = ntohs(ip->ip_len) - off; else mhip->ip_off |= IP_MF; mhip->ip_len = htons((u_int16_t)(len + mhlen)); m->m_next = m_copym(m0, off, len, M_NOWAIT); if (m->m_next == 0) { ipstat.ips_odropped++; error = ENOBUFS; goto sendorfree; } m->m_pkthdr.len = mhlen + len; m->m_pkthdr.ph_ifidx = 0; mhip->ip_off = htons((u_int16_t)mhip->ip_off); mhip->ip_sum = 0; if ((ifp != NULL) && (ifp->if_capabilities & IFCAP_CSUM_IPv4) && (ifp->if_bridgeport == NULL)) m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; else { ipstat.ips_outswcsum++; mhip->ip_sum = in_cksum(m, mhlen); } ipstat.ips_ofragments++; fragments++; } /* * Update first fragment by trimming what's been copied out * and updating header, then send each fragment (in order). */ m = m0; m_adj(m, hlen + firstlen - ntohs(ip->ip_len)); m->m_pkthdr.len = hlen + firstlen; ip->ip_len = htons((u_int16_t)m->m_pkthdr.len); ip->ip_off |= htons(IP_MF); ip->ip_sum = 0; if ((ifp != NULL) && (ifp->if_capabilities & IFCAP_CSUM_IPv4) && (ifp->if_bridgeport == NULL)) m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; else { ipstat.ips_outswcsum++; ip->ip_sum = in_cksum(m, hlen); } sendorfree: if (error) { for (m = m0; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = NULL; m_freem(m); } } return (error); } /* * Insert IP options into preformed packet. * Adjust IP destination as required for IP source routing, * as indicated by a non-zero in_addr at the start of the options. */ struct mbuf * ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen) { struct ipoption *p = mtod(opt, struct ipoption *); struct mbuf *n; struct ip *ip = mtod(m, struct ip *); unsigned int optlen; optlen = opt->m_len - sizeof(p->ipopt_dst); if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) return (m); /* XXX should fail */ if (p->ipopt_dst.s_addr) ip->ip_dst = p->ipopt_dst; if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) { MGETHDR(n, M_DONTWAIT, MT_HEADER); if (n == NULL) return (m); M_MOVE_HDR(n, m); n->m_pkthdr.len += optlen; m->m_len -= sizeof(struct ip); m->m_data += sizeof(struct ip); n->m_next = m; m = n; m->m_len = optlen + sizeof(struct ip); m->m_data += max_linkhdr; bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); } else { m->m_data -= optlen; m->m_len += optlen; m->m_pkthdr.len += optlen; memmove(mtod(m, caddr_t), (caddr_t)ip, sizeof(struct ip)); } ip = mtod(m, struct ip *); bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), optlen); *phlen = sizeof(struct ip) + optlen; ip->ip_len = htons(ntohs(ip->ip_len) + optlen); return (m); } /* * Copy options from ip to jp, * omitting those not copied during fragmentation. */ int ip_optcopy(struct ip *ip, struct ip *jp) { u_char *cp, *dp; int opt, optlen, cnt; cp = (u_char *)(ip + 1); dp = (u_char *)(jp + 1); cnt = (ip->ip_hl << 2) - sizeof (struct ip); for (; cnt > 0; cnt -= optlen, cp += optlen) { opt = cp[0]; if (opt == IPOPT_EOL) break; if (opt == IPOPT_NOP) { /* Preserve for IP mcast tunnel's LSRR alignment. */ *dp++ = IPOPT_NOP; optlen = 1; continue; } #ifdef DIAGNOSTIC if (cnt < IPOPT_OLEN + sizeof(*cp)) panic("malformed IPv4 option passed to ip_optcopy"); #endif optlen = cp[IPOPT_OLEN]; #ifdef DIAGNOSTIC if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) panic("malformed IPv4 option passed to ip_optcopy"); #endif /* bogus lengths should have been caught by ip_dooptions */ if (optlen > cnt) optlen = cnt; if (IPOPT_COPIED(opt)) { bcopy((caddr_t)cp, (caddr_t)dp, optlen); dp += optlen; } } for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) *dp++ = IPOPT_EOL; return (optlen); } /* * IP socket option processing. */ int ip_ctloutput(int op, struct socket *so, int level, int optname, struct mbuf **mp) { struct inpcb *inp = sotoinpcb(so); struct mbuf *m = *mp; int optval = 0; struct proc *p = curproc; /* XXX */ int error = 0; u_int rtid = 0; if (level != IPPROTO_IP) { error = EINVAL; if (op == PRCO_SETOPT) (void) m_free(*mp); } else switch (op) { case PRCO_SETOPT: switch (optname) { case IP_OPTIONS: return (ip_pcbopts(&inp->inp_options, m)); case IP_TOS: case IP_TTL: case IP_MINTTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: case IP_RECVTTL: case IP_RECVDSTPORT: case IP_RECVRTABLE: case IP_IPSECFLOWINFO: if (m == NULL || m->m_len != sizeof(int)) error = EINVAL; else { optval = *mtod(m, int *); switch (optname) { case IP_TOS: inp->inp_ip.ip_tos = optval; break; case IP_TTL: if (optval > 0 && optval <= MAXTTL) inp->inp_ip.ip_ttl = optval; else error = EINVAL; break; case IP_MINTTL: if (optval > 0 && optval <= MAXTTL) inp->inp_ip_minttl = optval; else error = EINVAL; break; #define OPTSET(bit) \ if (optval) \ inp->inp_flags |= bit; \ else \ inp->inp_flags &= ~bit; case IP_RECVOPTS: OPTSET(INP_RECVOPTS); break; case IP_RECVRETOPTS: OPTSET(INP_RECVRETOPTS); break; case IP_RECVDSTADDR: OPTSET(INP_RECVDSTADDR); break; case IP_RECVIF: OPTSET(INP_RECVIF); break; case IP_RECVTTL: OPTSET(INP_RECVTTL); break; case IP_RECVDSTPORT: OPTSET(INP_RECVDSTPORT); break; case IP_RECVRTABLE: OPTSET(INP_RECVRTABLE); break; case IP_IPSECFLOWINFO: OPTSET(INP_IPSECFLOWINFO); break; } } break; #undef OPTSET case IP_MULTICAST_IF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_ADD_MEMBERSHIP: case IP_DROP_MEMBERSHIP: error = ip_setmoptions(optname, &inp->inp_moptions, m, inp->inp_rtableid); break; case IP_PORTRANGE: if (m == NULL || m->m_len != sizeof(int)) error = EINVAL; else { optval = *mtod(m, int *); switch (optval) { case IP_PORTRANGE_DEFAULT: inp->inp_flags &= ~(INP_LOWPORT); inp->inp_flags &= ~(INP_HIGHPORT); break; case IP_PORTRANGE_HIGH: inp->inp_flags &= ~(INP_LOWPORT); inp->inp_flags |= INP_HIGHPORT; break; case IP_PORTRANGE_LOW: inp->inp_flags &= ~(INP_HIGHPORT); inp->inp_flags |= INP_LOWPORT; break; default: error = EINVAL; break; } } break; case IP_AUTH_LEVEL: case IP_ESP_TRANS_LEVEL: case IP_ESP_NETWORK_LEVEL: case IP_IPCOMP_LEVEL: #ifndef IPSEC error = EOPNOTSUPP; #else if (m == NULL || m->m_len != sizeof(int)) { error = EINVAL; break; } optval = *mtod(m, int *); if (optval < IPSEC_LEVEL_BYPASS || optval > IPSEC_LEVEL_UNIQUE) { error = EINVAL; break; } switch (optname) { case IP_AUTH_LEVEL: if (optval < IPSEC_AUTH_LEVEL_DEFAULT && suser(p, 0)) { error = EACCES; break; } inp->inp_seclevel[SL_AUTH] = optval; break; case IP_ESP_TRANS_LEVEL: if (optval < IPSEC_ESP_TRANS_LEVEL_DEFAULT && suser(p, 0)) { error = EACCES; break; } inp->inp_seclevel[SL_ESP_TRANS] = optval; break; case IP_ESP_NETWORK_LEVEL: if (optval < IPSEC_ESP_NETWORK_LEVEL_DEFAULT && suser(p, 0)) { error = EACCES; break; } inp->inp_seclevel[SL_ESP_NETWORK] = optval; break; case IP_IPCOMP_LEVEL: if (optval < IPSEC_IPCOMP_LEVEL_DEFAULT && suser(p, 0)) { error = EACCES; break; } inp->inp_seclevel[SL_IPCOMP] = optval; break; } #endif break; case IP_IPSEC_LOCAL_ID: case IP_IPSEC_REMOTE_ID: error = EOPNOTSUPP; break; case SO_RTABLE: if (m == NULL || m->m_len < sizeof(u_int)) { error = EINVAL; break; } rtid = *mtod(m, u_int *); if (inp->inp_rtableid == rtid) break; /* needs priviledges to switch when already set */ if (p->p_p->ps_rtableid != rtid && p->p_p->ps_rtableid != 0 && (error = suser(p, 0)) != 0) break; /* table must exist */ if (!rtable_exists(rtid)) { error = EINVAL; break; } inp->inp_rtableid = rtid; break; case IP_PIPEX: if (m != NULL && m->m_len == sizeof(int)) inp->inp_pipex = *mtod(m, int *); else error = EINVAL; break; default: error = ENOPROTOOPT; break; } if (m) (void)m_free(m); break; case PRCO_GETOPT: switch (optname) { case IP_OPTIONS: case IP_RETOPTS: *mp = m = m_get(M_WAIT, MT_SOOPTS); if (inp->inp_options) { m->m_len = inp->inp_options->m_len; bcopy(mtod(inp->inp_options, caddr_t), mtod(m, caddr_t), m->m_len); } else m->m_len = 0; break; case IP_TOS: case IP_TTL: case IP_MINTTL: case IP_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: case IP_RECVTTL: case IP_RECVDSTPORT: case IP_RECVRTABLE: case IP_IPSECFLOWINFO: case IP_IPDEFTTL: *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(int); switch (optname) { case IP_TOS: optval = inp->inp_ip.ip_tos; break; case IP_TTL: optval = inp->inp_ip.ip_ttl; break; case IP_MINTTL: optval = inp->inp_ip_minttl; break; case IP_IPDEFTTL: optval = ip_defttl; break; #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0) case IP_RECVOPTS: optval = OPTBIT(INP_RECVOPTS); break; case IP_RECVRETOPTS: optval = OPTBIT(INP_RECVRETOPTS); break; case IP_RECVDSTADDR: optval = OPTBIT(INP_RECVDSTADDR); break; case IP_RECVIF: optval = OPTBIT(INP_RECVIF); break; case IP_RECVTTL: optval = OPTBIT(INP_RECVTTL); break; case IP_RECVDSTPORT: optval = OPTBIT(INP_RECVDSTPORT); break; case IP_RECVRTABLE: optval = OPTBIT(INP_RECVRTABLE); break; case IP_IPSECFLOWINFO: optval = OPTBIT(INP_IPSECFLOWINFO); break; } *mtod(m, int *) = optval; break; case IP_MULTICAST_IF: case IP_MULTICAST_TTL: case IP_MULTICAST_LOOP: case IP_ADD_MEMBERSHIP: case IP_DROP_MEMBERSHIP: error = ip_getmoptions(optname, inp->inp_moptions, mp); break; case IP_PORTRANGE: *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(int); if (inp->inp_flags & INP_HIGHPORT) optval = IP_PORTRANGE_HIGH; else if (inp->inp_flags & INP_LOWPORT) optval = IP_PORTRANGE_LOW; else optval = 0; *mtod(m, int *) = optval; break; case IP_AUTH_LEVEL: case IP_ESP_TRANS_LEVEL: case IP_ESP_NETWORK_LEVEL: case IP_IPCOMP_LEVEL: *mp = m = m_get(M_WAIT, MT_SOOPTS); #ifndef IPSEC m->m_len = sizeof(int); *mtod(m, int *) = IPSEC_LEVEL_NONE; #else m->m_len = sizeof(int); switch (optname) { case IP_AUTH_LEVEL: optval = inp->inp_seclevel[SL_AUTH]; break; case IP_ESP_TRANS_LEVEL: optval = inp->inp_seclevel[SL_ESP_TRANS]; break; case IP_ESP_NETWORK_LEVEL: optval = inp->inp_seclevel[SL_ESP_NETWORK]; break; case IP_IPCOMP_LEVEL: optval = inp->inp_seclevel[SL_IPCOMP]; break; } *mtod(m, int *) = optval; #endif break; case IP_IPSEC_LOCAL_ID: case IP_IPSEC_REMOTE_ID: error = EOPNOTSUPP; break; case SO_RTABLE: *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(u_int); *mtod(m, u_int *) = inp->inp_rtableid; break; case IP_PIPEX: *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(int); *mtod(m, int *) = inp->inp_pipex; break; default: error = ENOPROTOOPT; break; } break; } return (error); } /* * Set up IP options in pcb for insertion in output packets. * Store in mbuf with pointer in pcbopt, adding pseudo-option * with destination address if source routed. */ int ip_pcbopts(struct mbuf **pcbopt, struct mbuf *m) { int cnt, optlen; u_char *cp; u_char opt; /* turn off any old options */ if (*pcbopt) (void)m_free(*pcbopt); *pcbopt = 0; if (m == NULL || m->m_len == 0) { /* * Only turning off any previous options. */ if (m) (void)m_free(m); return (0); } if (m->m_len % sizeof(int32_t)) goto bad; /* * IP first-hop destination address will be stored before * actual options; move other options back * and clear it when none present. */ if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN]) goto bad; cnt = m->m_len; m->m_len += sizeof(struct in_addr); cp = mtod(m, u_char *) + sizeof(struct in_addr); memmove((caddr_t)cp, mtod(m, caddr_t), (unsigned)cnt); memset(mtod(m, caddr_t), 0, sizeof(struct in_addr)); for (; cnt > 0; cnt -= optlen, cp += optlen) { opt = cp[IPOPT_OPTVAL]; if (opt == IPOPT_EOL) break; if (opt == IPOPT_NOP) optlen = 1; else { if (cnt < IPOPT_OLEN + sizeof(*cp)) goto bad; optlen = cp[IPOPT_OLEN]; if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) goto bad; } switch (opt) { default: break; case IPOPT_LSRR: case IPOPT_SSRR: /* * user process specifies route as: * ->A->B->C->D * D must be our final destination (but we can't * check that since we may not have connected yet). * A is first hop destination, which doesn't appear in * actual IP option, but is stored before the options. */ if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr)) goto bad; m->m_len -= sizeof(struct in_addr); cnt -= sizeof(struct in_addr); optlen -= sizeof(struct in_addr); cp[IPOPT_OLEN] = optlen; /* * Move first hop before start of options. */ bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t), sizeof(struct in_addr)); /* * Then copy rest of options back * to close up the deleted entry. */ memmove((caddr_t)&cp[IPOPT_OFFSET+1], (caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), (unsigned)cnt - (IPOPT_OFFSET+1)); break; } } if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr)) goto bad; *pcbopt = m; return (0); bad: (void)m_free(m); return (EINVAL); } /* * Set the IP multicast options in response to user setsockopt(). */ int ip_setmoptions(int optname, struct ip_moptions **imop, struct mbuf *m, u_int rtableid) { struct in_addr addr; struct in_ifaddr *ia; struct ip_mreq *mreq; struct ifnet *ifp = NULL; struct ip_moptions *imo = *imop; struct in_multi **immp; struct rtentry *rt; struct sockaddr_in sin; int i, error = 0; u_char loop; if (imo == NULL) { /* * No multicast option buffer attached to the pcb; * allocate one and initialize to default values. */ imo = malloc(sizeof(*imo), M_IPMOPTS, M_WAITOK|M_ZERO); immp = (struct in_multi **)malloc( (sizeof(*immp) * IP_MIN_MEMBERSHIPS), M_IPMOPTS, M_WAITOK|M_ZERO); *imop = imo; imo->imo_ifidx = 0; imo->imo_ttl = IP_DEFAULT_MULTICAST_TTL; imo->imo_loop = IP_DEFAULT_MULTICAST_LOOP; imo->imo_num_memberships = 0; imo->imo_max_memberships = IP_MIN_MEMBERSHIPS; imo->imo_membership = immp; } switch (optname) { case IP_MULTICAST_IF: /* * Select the interface for outgoing multicast packets. */ if (m == NULL || m->m_len != sizeof(struct in_addr)) { error = EINVAL; break; } addr = *(mtod(m, struct in_addr *)); /* * INADDR_ANY is used to remove a previous selection. * When no interface is selected, a default one is * chosen every time a multicast packet is sent. */ if (addr.s_addr == INADDR_ANY) { imo->imo_ifidx = 0; break; } /* * The selected interface is identified by its local * IP address. Find the interface and confirm that * it supports multicasting. */ memset(&sin, 0, sizeof(sin)); sin.sin_len = sizeof(sin); sin.sin_family = AF_INET; sin.sin_addr = addr; ia = ifatoia(ifa_ifwithaddr(sintosa(&sin), rtableid)); if (ia && in_hosteq(sin.sin_addr, ia->ia_addr.sin_addr)) ifp = ia->ia_ifp; if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { error = EADDRNOTAVAIL; break; } imo->imo_ifidx = ifp->if_index; break; case IP_MULTICAST_TTL: /* * Set the IP time-to-live for outgoing multicast packets. */ if (m == NULL || m->m_len != 1) { error = EINVAL; break; } imo->imo_ttl = *(mtod(m, u_char *)); break; case IP_MULTICAST_LOOP: /* * Set the loopback flag for outgoing multicast packets. * Must be zero or one. */ if (m == NULL || m->m_len != 1 || (loop = *(mtod(m, u_char *))) > 1) { error = EINVAL; break; } imo->imo_loop = loop; break; case IP_ADD_MEMBERSHIP: /* * Add a multicast group membership. * Group must be a valid IP multicast address. */ if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { error = EINVAL; break; } mreq = mtod(m, struct ip_mreq *); if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { error = EINVAL; break; } /* * If no interface address was provided, use the interface of * the route to the given multicast address. */ if (mreq->imr_interface.s_addr == INADDR_ANY) { memset(&sin, 0, sizeof(sin)); sin.sin_len = sizeof(sin); sin.sin_family = AF_INET; sin.sin_addr = mreq->imr_multiaddr; rt = rtalloc(sintosa(&sin), RT_REPORT|RT_RESOLVE, rtableid); if (rt == NULL) { error = EADDRNOTAVAIL; break; } ifp = rt->rt_ifp; rtfree(rt); } else { memset(&sin, 0, sizeof(sin)); sin.sin_len = sizeof(sin); sin.sin_family = AF_INET; sin.sin_addr = mreq->imr_interface; ia = ifatoia(ifa_ifwithaddr(sintosa(&sin), rtableid)); if (ia && in_hosteq(sin.sin_addr, ia->ia_addr.sin_addr)) ifp = ia->ia_ifp; } /* * See if we found an interface, and confirm that it * supports multicast. */ if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { error = EADDRNOTAVAIL; break; } /* * See if the membership already exists or if all the * membership slots are full. */ for (i = 0; i < imo->imo_num_memberships; ++i) { if (imo->imo_membership[i]->inm_ifidx == ifp->if_index && imo->imo_membership[i]->inm_addr.s_addr == mreq->imr_multiaddr.s_addr) break; } if (i < imo->imo_num_memberships) { error = EADDRINUSE; break; } if (imo->imo_num_memberships == imo->imo_max_memberships) { struct in_multi **nmships, **omships; size_t newmax; /* * Resize the vector to next power-of-two minus 1. If the * size would exceed the maximum then we know we've really * run out of entries. Otherwise, we reallocate the vector. */ nmships = NULL; omships = imo->imo_membership; newmax = ((imo->imo_max_memberships + 1) * 2) - 1; if (newmax <= IP_MAX_MEMBERSHIPS) { nmships = (struct in_multi **)malloc( sizeof(*nmships) * newmax, M_IPMOPTS, M_NOWAIT|M_ZERO); if (nmships != NULL) { bcopy(omships, nmships, sizeof(*omships) * imo->imo_max_memberships); free(omships, M_IPMOPTS, sizeof(*omships) * imo->imo_max_memberships); imo->imo_membership = nmships; imo->imo_max_memberships = newmax; } } if (nmships == NULL) { error = ETOOMANYREFS; break; } } /* * Everything looks good; add a new record to the multicast * address list for the given interface. */ if ((imo->imo_membership[i] = in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) { error = ENOBUFS; break; } ++imo->imo_num_memberships; break; case IP_DROP_MEMBERSHIP: /* * Drop a multicast group membership. * Group must be a valid IP multicast address. */ if (m == NULL || m->m_len != sizeof(struct ip_mreq)) { error = EINVAL; break; } mreq = mtod(m, struct ip_mreq *); if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) { error = EINVAL; break; } /* * If an interface address was specified, get a pointer * to its ifnet structure. */ if (mreq->imr_interface.s_addr == INADDR_ANY) ifp = NULL; else { memset(&sin, 0, sizeof(sin)); sin.sin_len = sizeof(sin); sin.sin_family = AF_INET; sin.sin_addr = mreq->imr_interface; ia = ifatoia(ifa_ifwithaddr(sintosa(&sin), rtableid)); if (ia && in_hosteq(sin.sin_addr, ia->ia_addr.sin_addr)) ifp = ia->ia_ifp; else { error = EADDRNOTAVAIL; break; } } /* * Find the membership in the membership array. */ for (i = 0; i < imo->imo_num_memberships; ++i) { if ((ifp == NULL || imo->imo_membership[i]->inm_ifidx == ifp->if_index) && imo->imo_membership[i]->inm_addr.s_addr == mreq->imr_multiaddr.s_addr) break; } if (i == imo->imo_num_memberships) { error = EADDRNOTAVAIL; break; } /* * Give up the multicast address record to which the * membership points. */ in_delmulti(imo->imo_membership[i]); /* * Remove the gap in the membership array. */ for (++i; i < imo->imo_num_memberships; ++i) imo->imo_membership[i-1] = imo->imo_membership[i]; --imo->imo_num_memberships; break; default: error = EOPNOTSUPP; break; } /* * If all options have default values, no need to keep the data. */ if (imo->imo_ifidx == 0 && imo->imo_ttl == IP_DEFAULT_MULTICAST_TTL && imo->imo_loop == IP_DEFAULT_MULTICAST_LOOP && imo->imo_num_memberships == 0) { free(imo->imo_membership , M_IPMOPTS, 0); free(*imop, M_IPMOPTS, sizeof(**imop)); *imop = NULL; } return (error); } /* * Return the IP multicast options in response to user getsockopt(). */ int ip_getmoptions(int optname, struct ip_moptions *imo, struct mbuf **mp) { u_char *ttl; u_char *loop; struct in_addr *addr; struct in_ifaddr *ia; struct ifnet *ifp; *mp = m_get(M_WAIT, MT_SOOPTS); switch (optname) { case IP_MULTICAST_IF: addr = mtod(*mp, struct in_addr *); (*mp)->m_len = sizeof(struct in_addr); if (imo == NULL || (ifp = if_get(imo->imo_ifidx)) == NULL) addr->s_addr = INADDR_ANY; else { IFP_TO_IA(ifp, ia); if_put(ifp); addr->s_addr = (ia == NULL) ? INADDR_ANY : ia->ia_addr.sin_addr.s_addr; } return (0); case IP_MULTICAST_TTL: ttl = mtod(*mp, u_char *); (*mp)->m_len = 1; *ttl = (imo == NULL) ? IP_DEFAULT_MULTICAST_TTL : imo->imo_ttl; return (0); case IP_MULTICAST_LOOP: loop = mtod(*mp, u_char *); (*mp)->m_len = 1; *loop = (imo == NULL) ? IP_DEFAULT_MULTICAST_LOOP : imo->imo_loop; return (0); default: return (EOPNOTSUPP); } } /* * Discard the IP multicast options. */ void ip_freemoptions(struct ip_moptions *imo) { int i; if (imo != NULL) { for (i = 0; i < imo->imo_num_memberships; ++i) in_delmulti(imo->imo_membership[i]); free(imo->imo_membership, M_IPMOPTS, 0); free(imo, M_IPMOPTS, sizeof(*imo)); } } /* * Routine called from ip_output() to loop back a copy of an IP multicast * packet to the input queue of a specified interface. */ void ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst) { struct ip *ip; struct mbuf *copym; copym = m_copym2(m, 0, M_COPYALL, M_DONTWAIT); if (copym != NULL) { /* * We don't bother to fragment if the IP length is greater * than the interface's MTU. Can this possibly matter? */ ip = mtod(copym, struct ip *); ip->ip_sum = 0; ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); if_input_local(ifp, copym, dst->sin_family); } } /* * Compute significant parts of the IPv4 checksum pseudo-header * for use in a delayed TCP/UDP checksum calculation. */ static __inline u_int16_t __attribute__((__unused__)) in_cksum_phdr(u_int32_t src, u_int32_t dst, u_int32_t lenproto) { u_int32_t sum; sum = lenproto + (u_int16_t)(src >> 16) + (u_int16_t)(src /*& 0xffff*/) + (u_int16_t)(dst >> 16) + (u_int16_t)(dst /*& 0xffff*/); sum = (u_int16_t)(sum >> 16) + (u_int16_t)(sum /*& 0xffff*/); if (sum > 0xffff) sum -= 0xffff; return (sum); } /* * Process a delayed payload checksum calculation. */ void in_delayed_cksum(struct mbuf *m) { struct ip *ip; u_int16_t csum, offset; ip = mtod(m, struct ip *); offset = ip->ip_hl << 2; csum = in4_cksum(m, 0, offset, m->m_pkthdr.len - offset); if (csum == 0 && ip->ip_p == IPPROTO_UDP) csum = 0xffff; switch (ip->ip_p) { case IPPROTO_TCP: offset += offsetof(struct tcphdr, th_sum); break; case IPPROTO_UDP: offset += offsetof(struct udphdr, uh_sum); break; case IPPROTO_ICMP: offset += offsetof(struct icmp, icmp_cksum); break; default: return; } if ((offset + sizeof(u_int16_t)) > m->m_len) m_copyback(m, offset, sizeof(csum), &csum, M_NOWAIT); else *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; } void in_proto_cksum_out(struct mbuf *m, struct ifnet *ifp) { struct ip *ip = mtod(m, struct ip *); /* some hw and in_delayed_cksum need the pseudo header cksum */ if (m->m_pkthdr.csum_flags & (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT|M_ICMP_CSUM_OUT)) { u_int16_t csum = 0, offset; offset = ip->ip_hl << 2; if (m->m_pkthdr.csum_flags & (M_TCP_CSUM_OUT|M_UDP_CSUM_OUT)) csum = in_cksum_phdr(ip->ip_src.s_addr, ip->ip_dst.s_addr, htonl(ntohs(ip->ip_len) - offset + ip->ip_p)); if (ip->ip_p == IPPROTO_TCP) offset += offsetof(struct tcphdr, th_sum); else if (ip->ip_p == IPPROTO_UDP) offset += offsetof(struct udphdr, uh_sum); else if (ip->ip_p == IPPROTO_ICMP) offset += offsetof(struct icmp, icmp_cksum); if ((offset + sizeof(u_int16_t)) > m->m_len) m_copyback(m, offset, sizeof(csum), &csum, M_NOWAIT); else *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; } if (m->m_pkthdr.csum_flags & M_TCP_CSUM_OUT) { if (!ifp || !(ifp->if_capabilities & IFCAP_CSUM_TCPv4) || ip->ip_hl != 5 || ifp->if_bridgeport != NULL) { tcpstat.tcps_outswcsum++; in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~M_TCP_CSUM_OUT; /* Clear */ } } else if (m->m_pkthdr.csum_flags & M_UDP_CSUM_OUT) { if (!ifp || !(ifp->if_capabilities & IFCAP_CSUM_UDPv4) || ip->ip_hl != 5 || ifp->if_bridgeport != NULL) { udpstat.udps_outswcsum++; in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~M_UDP_CSUM_OUT; /* Clear */ } } else if (m->m_pkthdr.csum_flags & M_ICMP_CSUM_OUT) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~M_ICMP_CSUM_OUT; /* Clear */ } }