/* $OpenBSD: ip_output.c,v 1.204 2010/01/13 12:09:36 claudio 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 extern u_int8_t get_sa_require(struct inpcb *); extern int ipsec_auth_default_level; extern int ipsec_esp_trans_default_level; extern int ipsec_esp_network_default_level; extern int ipsec_ipcomp_default_level; extern int ipforwarding; #endif /* IPSEC */ #ifdef MROUTING extern int ipmforwarding; #endif struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); void ip_mloopback(struct ifnet *, struct mbuf *, struct sockaddr_in *); /* * 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 ip *ip; struct ifnet *ifp; struct mbuf *m = m0; int hlen = sizeof (struct ip); int len, error = 0; struct route iproute; struct sockaddr_in *dst; struct in_ifaddr *ia; struct mbuf *opt; struct route *ro; int flags; struct ip_moptions *imo; va_list ap; u_int8_t sproto = 0, donerouting = 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 inpcb *inp; struct tdb *tdb; int s; #endif /* IPSEC */ va_start(ap, m0); opt = va_arg(ap, struct mbuf *); ro = va_arg(ap, struct route *); flags = va_arg(ap, int); imo = va_arg(ap, struct ip_moptions *); #ifdef IPSEC inp = va_arg(ap, struct inpcb *); if (inp && (inp->inp_flags & INP_IPV6) != 0) panic("ip_output: IPv6 pcb is passed"); #endif /* IPSEC */ va_end(ap); #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; } /* * If we're missing the IP source address, do a route lookup. We'll * remember this result, in case we don't need to do any IPsec * processing on the packet. We need the source address so we can * 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 (ip->ip_src.s_addr == INADDR_ANY) { if (flags & IP_ROUTETOETHER) { error = EINVAL; goto bad; } donerouting = 1; if (ro == 0) { ro = &iproute; bzero((caddr_t)ro, 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 (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { RTFREE(ro->ro_rt); ro->ro_rt = (struct rtentry *)0; } if (ro->ro_rt == 0) { dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = ip->ip_dst; } /* * If routing to interface only, short-circuit routing lookup. */ if (flags & IP_ROUTETOIF) { if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst), m->m_pkthdr.rdomain))) == 0 && (ia = ifatoia(ifa_ifwithnet(sintosa(dst), m->m_pkthdr.rdomain))) == 0) { ipstat.ips_noroute++; error = ENETUNREACH; goto bad; } ifp = ia->ia_ifp; mtu = ifp->if_mtu; ip->ip_ttl = 1; } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || (ip->ip_dst.s_addr == INADDR_BROADCAST)) && imo != NULL && imo->imo_multicast_ifp != NULL) { ifp = imo->imo_multicast_ifp; mtu = ifp->if_mtu; IFP_TO_IA(ifp, ia); } else { if (ro->ro_rt == 0) rtalloc_mpath(ro, NULL, m->m_pkthdr.rdomain); if (ro->ro_rt == 0) { ipstat.ips_noroute++; error = EHOSTUNREACH; goto bad; } ia = ifatoia(ro->ro_rt->rt_ifa); ifp = ro->ro_rt->rt_ifp; if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) mtu = ifp->if_mtu; ro->ro_rt->rt_use++; if (ro->ro_rt->rt_flags & RTF_GATEWAY) dst = satosin(ro->ro_rt->rt_gateway); } /* Set the source IP address */ if (!IN_MULTICAST(ip->ip_dst.s_addr)) ip->ip_src = ia->ia_addr.sin_addr; } #if NPF > 0 reroute: #endif #ifdef IPSEC if (!ipsec_in_use && inp == NULL) goto done_spd; /* * splnet is chosen over spltdb because we are not allowed to * lower the level, and udp_output calls us in splnet(). */ s = splnet(); /* Do we have any pending SAs to apply ? */ mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); if (mtag != NULL) { #ifdef DIAGNOSTIC if (mtag->m_tag_len != sizeof (struct tdb_ident)) panic("ip_output: tag of length %d (should be %d", mtag->m_tag_len, sizeof (struct tdb_ident)); #endif tdbi = (struct tdb_ident *)(mtag + 1); tdb = gettdb(tdbi->spi, &tdbi->dst, tdbi->proto); if (tdb == NULL) error = -EINVAL; m_tag_delete(m, mtag); } else tdb = ipsp_spd_lookup(m, AF_INET, hlen, &error, IPSP_DIRECTION_OUT, NULL, inp); if (tdb == NULL) { splx(s); 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 && mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) continue; tdbi = (struct tdb_ident *)(mtag + 1); if (tdbi->spi == tdb->tdb_spi && tdbi->proto == tdb->tdb_sproto && !bcmp(&tdbi->dst, &tdb->tdb_dst, sizeof(union sockaddr_union))) { splx(s); 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; splx(s); /* * If it needs TCP/UDP hardware-checksumming, do the * computation now. */ if (m->m_pkthdr.csum_flags & (M_TCPV4_CSUM_OUT | M_UDPV4_CSUM_OUT)) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~(M_UDPV4_CSUM_OUT | M_TCPV4_CSUM_OUT); } /* 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 (flags & IP_ROUTETOETHER) { dst = satosin(&ro->ro_dst); ifp = ro->ro_rt->rt_ifp; mtu = ifp->if_mtu; ro->ro_rt = NULL; } else if (donerouting == 0) { if (ro == 0) { ro = &iproute; bzero((caddr_t)ro, 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 (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || dst->sin_addr.s_addr != ip->ip_dst.s_addr)) { RTFREE(ro->ro_rt); ro->ro_rt = (struct rtentry *)0; } if (ro->ro_rt == 0) { dst->sin_family = AF_INET; dst->sin_len = sizeof(*dst); dst->sin_addr = ip->ip_dst; } /* * If routing to interface only, short-circuit routing lookup. */ if (flags & IP_ROUTETOIF) { if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst), m->m_pkthdr.rdomain))) == 0 && (ia = ifatoia(ifa_ifwithnet(sintosa(dst), m->m_pkthdr.rdomain))) == 0) { ipstat.ips_noroute++; error = ENETUNREACH; goto bad; } ifp = ia->ia_ifp; mtu = ifp->if_mtu; ip->ip_ttl = 1; } else if ((IN_MULTICAST(ip->ip_dst.s_addr) || (ip->ip_dst.s_addr == INADDR_BROADCAST)) && imo != NULL && imo->imo_multicast_ifp != NULL) { ifp = imo->imo_multicast_ifp; mtu = ifp->if_mtu; IFP_TO_IA(ifp, ia); } else { if (ro->ro_rt == 0) rtalloc_mpath(ro, &ip->ip_src.s_addr, m->m_pkthdr.rdomain); if (ro->ro_rt == 0) { ipstat.ips_noroute++; error = EHOSTUNREACH; goto bad; } ia = ifatoia(ro->ro_rt->rt_ifa); ifp = ro->ro_rt->rt_ifp; if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) mtu = ifp->if_mtu; ro->ro_rt->rt_use++; 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) ip->ip_src = ia->ia_addr.sin_addr; } 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_multicast_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) { struct in_ifaddr *ia; TAILQ_FOREACH(ia, &in_ifaddr, ia_list) if (ia->ia_ifp == ifp) { ip->ip_src = ia->ia_addr.sin_addr; break; } } IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm); if (inm != NULL && (imo == NULL || imo->imo_multicast_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. */ if (m->m_pkthdr.csum_flags & (M_TCPV4_CSUM_OUT | M_UDPV4_CSUM_OUT)) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~(M_UDPV4_CSUM_OUT | M_TCPV4_CSUM_OUT); } 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. */ extern struct socket *ip_mrouter; 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) && (in_broadcast(dst->sin_addr, ifp))) { 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) { s = splnet(); /* * Packet filter */ #if NPF > 0 if (pf_test(PF_OUT, &encif[0].sc_if, &m, NULL) != PF_PASS) { error = EHOSTUNREACH; splx(s); m_freem(m); goto done; } if (m == NULL) { splx(s); 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? */ #endif tdb = gettdb(sspi, &sdst, sproto); if (tdb == NULL) { DPRINTF(("ip_output: unknown TDB")); error = EHOSTUNREACH; splx(s); m_freem(m); goto done; } /* 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; splx(s); /* 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) { struct sockaddr_in dst = { sizeof(struct sockaddr_in), AF_INET}; dst.sin_addr = ip->ip_dst; rt = icmp_mtudisc_clone((struct sockaddr *)&dst, m->m_pkthdr.rdomain); 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 = NULL; rtalloc1(&ro->ro_dst, 1, m->m_pkthdr.rdomain); } 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); splx(s); return error; /* Nothing more to be done */ } /* * If deferred crypto processing is needed, check that the * interface supports it. */ if (ipsec_in_use && (mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL)) != NULL && (ifp->if_capabilities & IFCAP_IPSEC) == 0) { /* Notify IPsec to do its own crypto. */ ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); m_freem(m); error = EHOSTUNREACH; goto done; } #endif /* IPSEC */ /* Catch routing changes wrt. hardware checksumming for TCP or UDP. */ if (m->m_pkthdr.csum_flags & M_TCPV4_CSUM_OUT) { if (!(ifp->if_capabilities & IFCAP_CSUM_TCPv4) || ifp->if_bridge != NULL) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~M_TCPV4_CSUM_OUT; /* Clear */ } } else if (m->m_pkthdr.csum_flags & M_UDPV4_CSUM_OUT) { if (!(ifp->if_capabilities & IFCAP_CSUM_UDPv4) || ifp->if_bridge != NULL) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~M_UDPV4_CSUM_OUT; /* Clear */ } } /* * Packet filter */ #if NPF > 0 if (pf_test(PF_OUT, ifp, &m, NULL) != 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; donerouting = 0; goto reroute; } #endif #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 /* XXX * Try to use jumbograms based on socket option, or the route * or... for other reasons later on. */ if ((flags & IP_JUMBO) && ro->ro_rt && (ro->ro_rt->rt_flags & RTF_JUMBO) && ro->ro_rt->rt_ifp) mtu = ro->ro_rt->rt_ifp->if_hardmtu; /* * 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_bridge == NULL) { m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; ipstat.ips_outhwcsum++; } else ip->ip_sum = in_cksum(m, hlen); /* Update relevant hardware checksum stats for TCP/UDP */ if (m->m_pkthdr.csum_flags & M_TCPV4_CSUM_OUT) tcpstat.tcps_outhwcsum++; else if (m->m_pkthdr.csum_flags & M_UDPV4_CSUM_OUT) udpstat.udps_outhwcsum++; 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 (ro->ro_rt != NULL && (ro->ro_rt->rt_flags & (RTF_UP | 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 && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) RTFREE(ro->ro_rt); 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 s; 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. */ if (m->m_pkthdr.csum_flags & (M_TCPV4_CSUM_OUT | M_UDPV4_CSUM_OUT)) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~(M_UDPV4_CSUM_OUT | M_TCPV4_CSUM_OUT); } 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 == 0) { 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 rdomain */ m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); m->m_pkthdr.rdomain = m0->m_pkthdr.rdomain; 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_copy(m0, off, len); if (m->m_next == 0) { ipstat.ips_odropped++; error = ENOBUFS; goto sendorfree; } m->m_pkthdr.len = mhlen + len; m->m_pkthdr.rcvif = (struct ifnet *)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_bridge == NULL) { m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; ipstat.ips_outhwcsum++; } else 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_bridge == NULL) { m->m_pkthdr.csum_flags |= M_IPV4_CSUM_OUT; ipstat.ips_outhwcsum++; } else ip->ip_sum = in_cksum(m, hlen); sendorfree: /* * If there is no room for all the fragments, don't queue * any of them. * * Queue them anyway on virtual interfaces * (vlan, etc) with queue length 1 and hope the * underlying interface can cope. */ if (ifp != NULL && ifp->if_snd.ifq_maxlen != 1) { s = splnet(); if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments && error == 0) { error = ENOBUFS; ipstat.ips_odropped++; IFQ_INC_DROPS(&ifp->if_snd); } splx(s); } 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(m, opt, phlen) 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 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 == 0) 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; ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); } ip = mtod(m, struct ip *); bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)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(ip, jp) struct ip *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, (unsigned)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(op, so, level, optname, mp) int op; struct socket *so; int level, optname; struct mbuf **mp; { struct inpcb *inp = sotoinpcb(so); struct mbuf *m = *mp; int optval = 0; struct proc *p = curproc; /* XXX */ #ifdef IPSEC struct ipsec_ref *ipr; u_int16_t opt16val; #endif int error = 0; u_int rtid = 0; if (level != IPPROTO_IP) { error = EINVAL; if (op == PRCO_SETOPT && *mp) (void) m_free(*mp); } else switch (op) { case PRCO_SETOPT: switch (optname) { case IP_OPTIONS: #ifdef notyet case IP_RETOPTS: return (ip_pcbopts(optname, &inp->inp_options, m)); #else return (ip_pcbopts(&inp->inp_options, m)); #endif 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: 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; } } 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_rdomain); break; case IP_PORTRANGE: if (m == 0 || 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 == 0 || m->m_len != sizeof(int)) { error = EINVAL; break; } optval = *mtod(m, int *); if (optval < IPSEC_LEVEL_BYPASS || optval > IPSEC_LEVEL_UNIQUE) { error = EINVAL; break; } /* Unlink cached output TDB to force a re-search */ if (inp->inp_tdb_out) { int s = spltdb(); TAILQ_REMOVE(&inp->inp_tdb_out->tdb_inp_out, inp, inp_tdb_out_next); splx(s); } if (inp->inp_tdb_in) { int s = spltdb(); TAILQ_REMOVE(&inp->inp_tdb_in->tdb_inp_in, inp, inp_tdb_in_next); splx(s); } switch (optname) { case IP_AUTH_LEVEL: if (optval < ipsec_auth_default_level && suser(p, 0)) { error = EACCES; break; } inp->inp_seclevel[SL_AUTH] = optval; break; case IP_ESP_TRANS_LEVEL: if (optval < ipsec_esp_trans_default_level && suser(p, 0)) { error = EACCES; break; } inp->inp_seclevel[SL_ESP_TRANS] = optval; break; case IP_ESP_NETWORK_LEVEL: if (optval < ipsec_esp_network_default_level && suser(p, 0)) { error = EACCES; break; } inp->inp_seclevel[SL_ESP_NETWORK] = optval; break; case IP_IPCOMP_LEVEL: if (optval < ipsec_ipcomp_default_level && suser(p, 0)) { error = EACCES; break; } inp->inp_seclevel[SL_IPCOMP] = optval; break; } if (!error) inp->inp_secrequire = get_sa_require(inp); #endif break; case IP_IPSEC_REMOTE_CRED: case IP_IPSEC_REMOTE_AUTH: /* Can't set the remote credential or key */ error = EOPNOTSUPP; break; case IP_IPSEC_LOCAL_ID: case IP_IPSEC_REMOTE_ID: case IP_IPSEC_LOCAL_CRED: case IP_IPSEC_LOCAL_AUTH: #ifndef IPSEC error = EOPNOTSUPP; #else if (m == NULL || m->m_len < 2) { error = EINVAL; break; } m_copydata(m, 0, 2, (caddr_t) &opt16val); /* If the type is 0, then we cleanup and return */ if (opt16val == 0) { switch (optname) { case IP_IPSEC_LOCAL_ID: if (inp->inp_ipo != NULL && inp->inp_ipo->ipo_srcid != NULL) { ipsp_reffree(inp->inp_ipo->ipo_srcid); inp->inp_ipo->ipo_srcid = NULL; } break; case IP_IPSEC_REMOTE_ID: if (inp->inp_ipo != NULL && inp->inp_ipo->ipo_dstid != NULL) { ipsp_reffree(inp->inp_ipo->ipo_dstid); inp->inp_ipo->ipo_dstid = NULL; } break; case IP_IPSEC_LOCAL_CRED: if (inp->inp_ipo != NULL && inp->inp_ipo->ipo_local_cred != NULL) { ipsp_reffree(inp->inp_ipo->ipo_local_cred); inp->inp_ipo->ipo_local_cred = NULL; } break; case IP_IPSEC_LOCAL_AUTH: if (inp->inp_ipo != NULL && inp->inp_ipo->ipo_local_auth != NULL) { ipsp_reffree(inp->inp_ipo->ipo_local_auth); inp->inp_ipo->ipo_local_auth = NULL; } break; } error = 0; break; } /* Can't have an empty payload */ if (m->m_len == 2) { error = EINVAL; break; } /* Allocate if needed */ if (inp->inp_ipo == NULL) { inp->inp_ipo = ipsec_add_policy(inp, AF_INET, IPSP_DIRECTION_OUT); if (inp->inp_ipo == NULL) { error = ENOBUFS; break; } } ipr = malloc(sizeof(struct ipsec_ref) + m->m_len - 2, M_CREDENTIALS, M_NOWAIT); if (ipr == NULL) { error = ENOBUFS; break; } ipr->ref_count = 1; ipr->ref_malloctype = M_CREDENTIALS; ipr->ref_len = m->m_len - 2; ipr->ref_type = opt16val; m_copydata(m, 2, m->m_len - 2, (caddr_t)(ipr + 1)); switch (optname) { case IP_IPSEC_LOCAL_ID: /* Check valid types and NUL-termination */ if (ipr->ref_type < IPSP_IDENTITY_PREFIX || ipr->ref_type > IPSP_IDENTITY_CONNECTION || ((char *)(ipr + 1))[ipr->ref_len - 1]) { free(ipr, M_CREDENTIALS); error = EINVAL; } else { if (inp->inp_ipo->ipo_srcid != NULL) ipsp_reffree(inp->inp_ipo->ipo_srcid); inp->inp_ipo->ipo_srcid = ipr; } break; case IP_IPSEC_REMOTE_ID: /* Check valid types and NUL-termination */ if (ipr->ref_type < IPSP_IDENTITY_PREFIX || ipr->ref_type > IPSP_IDENTITY_CONNECTION || ((char *)(ipr + 1))[ipr->ref_len - 1]) { free(ipr, M_CREDENTIALS); error = EINVAL; } else { if (inp->inp_ipo->ipo_dstid != NULL) ipsp_reffree(inp->inp_ipo->ipo_dstid); inp->inp_ipo->ipo_dstid = ipr; } break; case IP_IPSEC_LOCAL_CRED: if (ipr->ref_type < IPSP_CRED_KEYNOTE || ipr->ref_type > IPSP_CRED_X509) { free(ipr, M_CREDENTIALS); error = EINVAL; } else { if (inp->inp_ipo->ipo_local_cred != NULL) ipsp_reffree(inp->inp_ipo->ipo_local_cred); inp->inp_ipo->ipo_local_cred = ipr; } break; case IP_IPSEC_LOCAL_AUTH: if (ipr->ref_type < IPSP_AUTH_PASSPHRASE || ipr->ref_type > IPSP_AUTH_RSA) { free(ipr, M_CREDENTIALS); error = EINVAL; } else { if (inp->inp_ipo->ipo_local_auth != NULL) ipsp_reffree(inp->inp_ipo->ipo_local_auth); inp->inp_ipo->ipo_local_auth = ipr; } break; } /* Unlink cached output TDB to force a re-search */ if (inp->inp_tdb_out) { int s = spltdb(); TAILQ_REMOVE(&inp->inp_tdb_out->tdb_inp_out, inp, inp_tdb_out_next); splx(s); } if (inp->inp_tdb_in) { int s = spltdb(); TAILQ_REMOVE(&inp->inp_tdb_in->tdb_inp_in, inp, inp_tdb_in_next); splx(s); } #endif break; case SO_RDOMAIN: if (m == NULL || m->m_len < sizeof(u_int)) { error = EINVAL; break; } rtid = *mtod(m, u_int *); if (p->p_p->ps_rdomain != 0 && p->p_p->ps_rdomain != rtid && (error = suser(p, 0)) != 0) { error = EACCES; break; } /* table must exist and be a domain */ if (!rtable_exists(rtid) || rtid != rtable_l2(rtid)) { error = EINVAL; break; } inp->inp_rdomain = rtid; 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), (unsigned)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: *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; #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; } *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: case IP_IPSEC_LOCAL_CRED: case IP_IPSEC_REMOTE_CRED: case IP_IPSEC_LOCAL_AUTH: case IP_IPSEC_REMOTE_AUTH: #ifndef IPSEC error = EOPNOTSUPP; #else *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(u_int16_t); ipr = NULL; switch (optname) { case IP_IPSEC_LOCAL_ID: if (inp->inp_ipo != NULL) ipr = inp->inp_ipo->ipo_srcid; opt16val = IPSP_IDENTITY_NONE; break; case IP_IPSEC_REMOTE_ID: if (inp->inp_ipo != NULL) ipr = inp->inp_ipo->ipo_dstid; opt16val = IPSP_IDENTITY_NONE; break; case IP_IPSEC_LOCAL_CRED: if (inp->inp_ipo != NULL) ipr = inp->inp_ipo->ipo_local_cred; opt16val = IPSP_CRED_NONE; break; case IP_IPSEC_REMOTE_CRED: ipr = inp->inp_ipsec_remotecred; opt16val = IPSP_CRED_NONE; break; case IP_IPSEC_LOCAL_AUTH: if (inp->inp_ipo != NULL) ipr = inp->inp_ipo->ipo_local_auth; opt16val = IPSP_AUTH_NONE; break; case IP_IPSEC_REMOTE_AUTH: ipr = inp->inp_ipsec_remoteauth; opt16val = IPSP_AUTH_NONE; break; } if (ipr == NULL) *mtod(m, u_int16_t *) = opt16val; else { size_t len; len = m->m_len + ipr->ref_len; if (len > MCLBYTES) { m_free(m); error = EINVAL; break; } /* allocate mbuf cluster for larger option */ if (len > MLEN) { MCLGET(m, M_WAITOK); if ((m->m_flags & M_EXT) == 0) { m_free(m); error = ENOBUFS; break; } } m->m_len = len; *mtod(m, u_int16_t *) = ipr->ref_type; m_copyback(m, sizeof(u_int16_t), ipr->ref_len, ipr + 1); } #endif break; case SO_RDOMAIN: *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(u_int); *mtod(m, u_int *) = inp->inp_rdomain; 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 #ifdef notyet ip_pcbopts(optname, pcbopt, m) int optname; #else ip_pcbopts(pcbopt, m) #endif 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 == (struct mbuf *)0 || 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); ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt); bzero(mtod(m, caddr_t), 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. */ ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)), (caddr_t)&cp[IPOPT_OFFSET+1], (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 rdomain) { int error = 0; u_char loop; int i; struct in_addr addr; struct ip_mreq *mreq; struct ifnet *ifp; struct ip_moptions *imo = *imop; struct in_multi **immp; struct route ro; struct sockaddr_in *dst; if (imo == NULL) { /* * No multicast option buffer attached to the pcb; * allocate one and initialize to default values. */ imo = (struct ip_moptions *)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_multicast_ifp = NULL; imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; imo->imo_multicast_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_multicast_ifp = NULL; break; } /* * The selected interface is identified by its local * IP address. Find the interface and confirm that * it supports multicasting. */ INADDR_TO_IFP(addr, ifp, rdomain); if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { error = EADDRNOTAVAIL; break; } imo->imo_multicast_ifp = ifp; 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_multicast_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_multicast_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) { ro.ro_rt = NULL; dst = satosin(&ro.ro_dst); dst->sin_len = sizeof(*dst); dst->sin_family = AF_INET; dst->sin_addr = mreq->imr_multiaddr; if (!(ro.ro_rt && ro.ro_rt->rt_ifp && (ro.ro_rt->rt_flags & RTF_UP))) ro.ro_rt = rtalloc1(&ro.ro_dst, 1, rdomain); if (ro.ro_rt == NULL) { error = EADDRNOTAVAIL; break; } ifp = ro.ro_rt->rt_ifp; rtfree(ro.ro_rt); } else { INADDR_TO_IFP(mreq->imr_interface, ifp, rdomain); } /* * 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_ia->ia_ifp == ifp && 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); 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 { INADDR_TO_IFP(mreq->imr_interface, ifp, rdomain); if (ifp == NULL) { 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_ia->ia_ifp == ifp) && 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_multicast_ifp == NULL && imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL && imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP && imo->imo_num_memberships == 0) { free(imo->imo_membership , M_IPMOPTS); free(*imop, M_IPMOPTS); *imop = NULL; } return (error); } /* * Return the IP multicast options in response to user getsockopt(). */ int ip_getmoptions(optname, imo, mp) int optname; struct ip_moptions *imo; struct mbuf **mp; { u_char *ttl; u_char *loop; struct in_addr *addr; struct in_ifaddr *ia; *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 || imo->imo_multicast_ifp == NULL) addr->s_addr = INADDR_ANY; else { IFP_TO_IA(imo->imo_multicast_ifp, ia); 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_multicast_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_multicast_loop; return (0); default: return (EOPNOTSUPP); } } /* * Discard the IP multicast options. */ void ip_freemoptions(imo) 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); free(imo, M_IPMOPTS); } } /* * Routine called from ip_output() to loop back a copy of an IP multicast * packet to the input queue of a specified interface. Note that this * calls the output routine of the loopback "driver", but with an interface * pointer that might NOT be &loif -- easier than replicating that code here. */ void ip_mloopback(ifp, m, dst) 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); (void) looutput(ifp, copym, sintosa(dst), NULL); } } /* * 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; default: return; } if ((offset + sizeof(u_int16_t)) > m->m_len) m_copyback(m, offset, sizeof(csum), &csum); else *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; }