/* $NetBSD: ip_output.c,v 1.153 2005/05/29 21:41:23 christos Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * 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 project 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 PROJECT 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 PROJECT 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. */ /*- * Copyright (c) 1998 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Public Access Networks Corporation ("Panix"). It was developed under * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon. * * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ /* * 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 __KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.153 2005/05/29 21:41:23 christos Exp $"); #include "opt_pfil_hooks.h" #include "opt_inet.h" #include "opt_ipsec.h" #include "opt_mrouting.h" #include #include #include #include #include #include #include #ifdef FAST_IPSEC #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #ifdef MROUTING #include #endif #include #ifdef IPSEC #include #include #include #ifdef IPSEC_NAT_T #include #endif #endif /*IPSEC*/ #ifdef FAST_IPSEC #include #include #include #endif /* FAST_IPSEC*/ static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *); static struct ifnet *ip_multicast_if(struct in_addr *, int *); static void ip_mloopback(struct ifnet *, struct mbuf *, struct sockaddr_in *); #ifdef PFIL_HOOKS extern struct pfil_head inet_pfil_hook; /* XXX */ #endif int udp_do_loopback_cksum = 0; int tcp_do_loopback_cksum = 0; int ip_do_loopback_cksum = 0; #define IN_NEED_CHECKSUM(ifp, csum_flags) \ (__predict_true(((ifp)->if_flags & IFF_LOOPBACK) == 0 || \ (((csum_flags) & M_CSUM_UDPv4) != 0 && udp_do_loopback_cksum) || \ (((csum_flags) & M_CSUM_TCPv4) != 0 && tcp_do_loopback_cksum) || \ (((csum_flags) & M_CSUM_IPv4) != 0 && ip_do_loopback_cksum))) struct ip_tso_output_args { struct ifnet *ifp; struct sockaddr *sa; struct rtentry *rt; }; static int ip_tso_output_callback(void *, struct mbuf *); static int ip_tso_output(struct ifnet *, struct mbuf *, struct sockaddr *, struct rtentry *); static int ip_tso_output_callback(void *vp, struct mbuf *m) { struct ip_tso_output_args *args = vp; struct ifnet *ifp = args->ifp; return (*ifp->if_output)(ifp, m, args->sa, args->rt); } static int ip_tso_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *sa, struct rtentry *rt) { struct ip_tso_output_args args; args.ifp = ifp; args.sa = sa; args.rt = rt; return tcp4_segment(m, ip_tso_output_callback, &args); } /* * 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, sw_csum; int *mtu_p; u_long mtu; struct ip_moptions *imo; struct socket *so; va_list ap; #ifdef IPSEC struct secpolicy *sp = NULL; #ifdef IPSEC_NAT_T int natt_frag = 0; #endif #endif /*IPSEC*/ #ifdef FAST_IPSEC struct inpcb *inp; struct m_tag *mtag; struct secpolicy *sp = NULL; struct tdb_ident *tdbi; int s; #endif u_int16_t ip_len; len = 0; 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 *); so = va_arg(ap, struct socket *); if (flags & IP_RETURNMTU) mtu_p = va_arg(ap, int *); else mtu_p = NULL; va_end(ap); MCLAIM(m, &ip_tx_mowner); #ifdef FAST_IPSEC if (so != NULL && so->so_proto->pr_domain->dom_family == AF_INET) inp = (struct inpcb *)so->so_pcb; else inp = NULL; #endif /* FAST_IPSEC */ #ifdef DIAGNOSTIC if ((m->m_flags & M_PKTHDR) == 0) panic("ip_output no HDR"); #endif if (opt) { m = ip_insertoptions(m, opt, &len); if (len >= sizeof(struct ip)) 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(0); if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { ip->ip_id = ip_newid(); } else { /* * TSO capable interfaces (typically?) increment * ip_id for each segment. * "allocate" enough ids here to increase the chance * for them to be unique. * * note that the following calculation is not * needed to be precise. wasting some ip_id is fine. */ unsigned int segsz = m->m_pkthdr.segsz; unsigned int datasz = ntohs(ip->ip_len) - hlen; unsigned int num = howmany(datasz, segsz); ip->ip_id = ip_newid_range(num); } ip->ip_hl = hlen >> 2; ipstat.ips_localout++; } else { hlen = ip->ip_hl << 2; } /* * Route packet. */ 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. * The address family should also be checked in case of sharing the * cache with IPv6. */ if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 || dst->sin_family != AF_INET || !in_hosteq(dst->sin_addr, ip->ip_dst))) { RTFREE(ro->ro_rt); ro->ro_rt = (struct rtentry *)0; } if (ro->ro_rt == 0) { bzero(dst, sizeof(*dst)); 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_ifwithladdr(sintosa(dst)))) == 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(ro); 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); } 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 = ENETUNREACH; goto bad; } /* * If the packet is multicast or broadcast, confirm that * the outgoing interface can transmit it. */ if (((m->m_flags & M_MCAST) && (ifp->if_flags & IFF_MULTICAST) == 0) || ((m->m_flags & M_BCAST) && (ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) { ipstat.ips_noroute++; error = ENETUNREACH; goto bad; } /* * If source address not specified yet, use an address * of outgoing interface. */ if (in_nullhost(ip->ip_src)) { struct in_ifaddr *xia; IFP_TO_IA(ifp, xia); if (!xia) { error = EADDRNOTAVAIL; goto bad; } ip->ip_src = xia->ia_addr.sin_addr; } 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. */ 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 (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; } #ifndef notdef /* * If source address not specified yet, use address * of outgoing interface. */ if (in_nullhost(ip->ip_src)) ip->ip_src = ia->ia_addr.sin_addr; #endif /* * packets with Class-D address as source are not valid per * RFC 1112 */ if (IN_MULTICAST(ip->ip_src.s_addr)) { ipstat.ips_odropped++; error = EADDRNOTAVAIL; goto bad; } /* * Look for broadcast address and * and verify user is allowed to send * such a packet. */ if (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) != 0 && ro->ro_rt != NULL && (ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0) ip->ip_off |= htons(IP_DF); /* Remember the current ip_len */ ip_len = ntohs(ip->ip_len); #ifdef IPSEC /* get SP for this packet */ if (so == NULL) sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error); else { if (IPSEC_PCB_SKIP_IPSEC(sotoinpcb_hdr(so)->inph_sp, IPSEC_DIR_OUTBOUND)) goto skip_ipsec; sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); } if (sp == NULL) { ipsecstat.out_inval++; goto bad; } error = 0; /* check policy */ switch (sp->policy) { case IPSEC_POLICY_DISCARD: /* * This packet is just discarded. */ ipsecstat.out_polvio++; goto bad; case IPSEC_POLICY_BYPASS: case IPSEC_POLICY_NONE: /* no need to do IPsec. */ goto skip_ipsec; case IPSEC_POLICY_IPSEC: if (sp->req == NULL) { /* XXX should be panic ? */ printf("ip_output: No IPsec request specified.\n"); error = EINVAL; goto bad; } break; case IPSEC_POLICY_ENTRUST: default: printf("ip_output: Invalid policy found. %d\n", sp->policy); } #ifdef IPSEC_NAT_T /* * NAT-T ESP fragmentation: don't do IPSec processing now, * we'll do it on each fragmented packet. */ if (sp->req->sav && ((sp->req->sav->natt_type & UDP_ENCAP_ESPINUDP) || (sp->req->sav->natt_type & UDP_ENCAP_ESPINUDP_NON_IKE))) { if (ntohs(ip->ip_len) > sp->req->sav->esp_frag) { natt_frag = 1; mtu = sp->req->sav->esp_frag; goto skip_ipsec; } } #endif /* IPSEC_NAT_T */ /* * ipsec4_output() expects ip_len and ip_off in network * order. They have been set to network order above. */ { struct ipsec_output_state state; bzero(&state, sizeof(state)); state.m = m; if (flags & IP_ROUTETOIF) { state.ro = &iproute; bzero(&iproute, sizeof(iproute)); } else state.ro = ro; state.dst = (struct sockaddr *)dst; /* * We can't defer the checksum of payload data if * we're about to encrypt/authenticate it. * * XXX When we support crypto offloading functions of * XXX network interfaces, we need to reconsider this, * XXX since it's likely that they'll support checksumming, * XXX as well. */ if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); } error = ipsec4_output(&state, sp, flags); m = state.m; if (flags & IP_ROUTETOIF) { /* * if we have tunnel mode SA, we may need to ignore * IP_ROUTETOIF. */ if (state.ro != &iproute || state.ro->ro_rt != NULL) { flags &= ~IP_ROUTETOIF; ro = state.ro; } } else ro = state.ro; dst = (struct sockaddr_in *)state.dst; if (error) { /* mbuf is already reclaimed in ipsec4_output. */ m0 = NULL; switch (error) { case EHOSTUNREACH: case ENETUNREACH: case EMSGSIZE: case ENOBUFS: case ENOMEM: break; default: printf("ip4_output (ipsec): error code %d\n", error); /*fall through*/ case ENOENT: /* don't show these error codes to the user */ error = 0; break; } goto bad; } /* be sure to update variables that are affected by ipsec4_output() */ ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; ip_len = ntohs(ip->ip_len); if (ro->ro_rt == NULL) { if ((flags & IP_ROUTETOIF) == 0) { printf("ip_output: " "can't update route after IPsec processing\n"); error = EHOSTUNREACH; /*XXX*/ goto bad; } } else { /* nobody uses ia beyond here */ if (state.encap) { ifp = ro->ro_rt->rt_ifp; if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0) mtu = ifp->if_mtu; } } } skip_ipsec: #endif /*IPSEC*/ #ifdef FAST_IPSEC /* * Check the security policy (SP) for the packet and, if * required, do IPsec-related processing. There are two * cases here; the first time a packet is sent through * it will be untagged and handled by ipsec4_checkpolicy. * If the packet is resubmitted to ip_output (e.g. after * AH, ESP, etc. processing), there will be a tag to bypass * the lookup and related policy checking. */ mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL); s = splsoftnet(); if (mtag != NULL) { tdbi = (struct tdb_ident *)(mtag + 1); sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND); if (sp == NULL) error = -EINVAL; /* force silent drop */ m_tag_delete(m, mtag); } else { if (inp != NULL && IPSEC_PCB_SKIP_IPSEC(inp->inp_sp, IPSEC_DIR_OUTBOUND)) goto spd_done; sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags, &error, inp); } /* * There are four return cases: * sp != NULL apply IPsec policy * sp == NULL, error == 0 no IPsec handling needed * sp == NULL, error == -EINVAL discard packet w/o error * sp == NULL, error != 0 discard packet, report error */ if (sp != NULL) { /* Loop detection, check if ipsec processing already done */ IPSEC_ASSERT(sp->req != NULL, ("ip_output: no ipsec request")); for (mtag = m_tag_first(m); mtag != NULL; mtag = m_tag_next(m, mtag)) { #ifdef MTAG_ABI_COMPAT if (mtag->m_tag_cookie != MTAG_ABI_COMPAT) continue; #endif if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE && mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED) continue; /* * Check if policy has an SA associated with it. * This can happen when an SP has yet to acquire * an SA; e.g. on first reference. If it occurs, * then we let ipsec4_process_packet do its thing. */ if (sp->req->sav == NULL) break; tdbi = (struct tdb_ident *)(mtag + 1); if (tdbi->spi == sp->req->sav->spi && tdbi->proto == sp->req->sav->sah->saidx.proto && bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst, sizeof (union sockaddr_union)) == 0) { /* * No IPsec processing is needed, free * reference to SP. * * NB: null pointer to avoid free at * done: below. */ KEY_FREESP(&sp), sp = NULL; splx(s); goto spd_done; } } /* * Do delayed checksums now because we send before * this is done in the normal processing path. */ if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { in_delayed_cksum(m); m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); } #ifdef __FreeBSD__ ip->ip_len = htons(ip->ip_len); ip->ip_off = htons(ip->ip_off); #endif /* NB: callee frees mbuf */ error = ipsec4_process_packet(m, sp->req, flags, 0); /* * Preserve KAME behaviour: ENOENT can be returned * when an SA acquire is in progress. Don't propagate * this to user-level; it confuses applications. * * XXX this will go away when the SADB is redone. */ if (error == ENOENT) error = 0; splx(s); goto done; } else { splx(s); if (error != 0) { /* * Hack: -EINVAL is used to signal that a packet * should be silently discarded. This is typically * because we asked key management for an SA and * it was delayed (e.g. kicked up to IKE). */ if (error == -EINVAL) error = 0; goto bad; } else { /* No IPsec processing for this packet. */ } #ifdef notyet /* * If deferred crypto processing is needed, check that * the interface supports it. */ mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL); if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) { /* notify IPsec to do its own crypto */ ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1)); error = EHOSTUNREACH; goto bad; } #endif } spd_done: #endif /* FAST_IPSEC */ #ifdef PFIL_HOOKS /* * Run through list of hooks for output packets. */ if ((error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT)) != 0) goto done; if (m == NULL) goto done; ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; #endif /* PFIL_HOOKS */ m->m_pkthdr.csum_data |= hlen << 16; #if IFA_STATS /* * search for the source address structure to * maintain output statistics. */ INADDR_TO_IA(ip->ip_src, ia); #endif /* Maybe skip checksums on loopback interfaces. */ if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) { m->m_pkthdr.csum_flags |= M_CSUM_IPv4; } sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx; /* * If small enough for mtu of path, or if using TCP segmentation * offload, can just send directly. */ if (ip_len <= mtu || (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) { #if IFA_STATS if (ia) ia->ia_ifa.ifa_data.ifad_outbytes += ip_len; #endif /* * Always initialize the sum to 0! Some HW assisted * checksumming requires this. */ ip->ip_sum = 0; if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) { /* * Perform any checksums that the hardware can't do * for us. * * XXX Does any hardware require the {th,uh}_sum * XXX fields to be 0? */ if (sw_csum & M_CSUM_IPv4) { KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)); ip->ip_sum = in_cksum(m, hlen); m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; } if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { if (IN_NEED_CHECKSUM(ifp, sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { in_delayed_cksum(m); } m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); } } #ifdef IPSEC /* clean ipsec history once it goes out of the node */ ipsec_delaux(m); #endif if (__predict_true( (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 || (ifp->if_capenable & IFCAP_TSOv4) != 0)) { error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_rt); } else { error = ip_tso_output(ifp, m, sintosa(dst), ro->ro_rt); } goto done; } /* * We can't use HW checksumming if we're about to * to fragment the packet. * * XXX Some hardware can do this. */ if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { if (IN_NEED_CHECKSUM(ifp, m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) { in_delayed_cksum(m); } m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); } /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. */ if (ntohs(ip->ip_off) & IP_DF) { if (flags & IP_RETURNMTU) *mtu_p = mtu; error = EMSGSIZE; ipstat.ips_cantfrag++; goto bad; } error = ip_fragment(m, ifp, mtu); if (error) { m = NULL; goto bad; } for (; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = 0; if (error == 0) { #if IFA_STATS if (ia) ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len); #endif #ifdef IPSEC /* clean ipsec history once it goes out of the node */ ipsec_delaux(m); #ifdef IPSEC_NAT_T /* * If we get there, the packet has not been handeld by * IPSec whereas it should have. Now that it has been * fragmented, re-inject it in ip_output so that IPsec * processing can occur. */ if (natt_frag) { error = ip_output(m, opt, ro, flags, imo, so, mtu_p); } else #endif /* IPSEC_NAT_T */ #endif /* IPSEC */ { KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 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); ro->ro_rt = 0; } #ifdef IPSEC if (sp != NULL) { KEYDEBUG(KEYDEBUG_IPSEC_STAMP, printf("DP ip_output call free SP:%p\n", sp)); key_freesp(sp); } #endif /* IPSEC */ #ifdef FAST_IPSEC if (sp != NULL) KEY_FREESP(&sp); #endif /* FAST_IPSEC */ return (error); bad: m_freem(m); 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 sw_csum = m->m_pkthdr.csum_flags; int fragments = 0; int s; int error = 0; ip = mtod(m, struct ip *); hlen = ip->ip_hl << 2; if (ifp != NULL) sw_csum &= ~ifp->if_csum_flags_tx; len = (mtu - hlen) &~ 7; if (len < 8) { m_freem(m); return (EMSGSIZE); } 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) { error = ENOBUFS; ipstat.ips_odropped++; goto sendorfree; } MCLAIM(m, m0->m_owner); *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 */ m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST); 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; HTONS(mhip->ip_off); mhip->ip_len = htons((u_int16_t)(len + mhlen)); m->m_next = m_copy(m0, off, len); if (m->m_next == 0) { error = ENOBUFS; /* ??? */ ipstat.ips_odropped++; goto sendorfree; } m->m_pkthdr.len = mhlen + len; m->m_pkthdr.rcvif = (struct ifnet *)0; mhip->ip_sum = 0; if (sw_csum & M_CSUM_IPv4) { mhip->ip_sum = in_cksum(m, mhlen); KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0); } else { m->m_pkthdr.csum_flags |= M_CSUM_IPv4; m->m_pkthdr.csum_data |= mhlen << 16; } 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 (sw_csum & M_CSUM_IPv4) { ip->ip_sum = in_cksum(m, hlen); m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4; } else { KASSERT(m->m_pkthdr.csum_flags & M_CSUM_IPv4); KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >= sizeof(struct ip)); } sendorfree: /* * If there is no room for all the fragments, don't queue * any of them. */ if (ifp != NULL) { 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); } /* * 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, ntohs(ip->ip_len) - offset); if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0) csum = 0xffff; offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data); if ((offset + sizeof(u_int16_t)) > m->m_len) { /* This happen when ip options were inserted printf("in_delayed_cksum: pullup len %d off %d proto %d\n", m->m_len, offset, ip->ip_p); */ m_copyback(m, offset, sizeof(csum), (caddr_t) &csum); } else *(u_int16_t *)(mtod(m, caddr_t) + offset) = csum; } /* * Determine the maximum length of the options to be inserted; * we would far rather allocate too much space rather than too little. */ u_int ip_optlen(struct inpcb *inp) { struct mbuf *m = inp->inp_options; if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) return (m->m_len - offsetof(struct ipoption, ipopt_dst)); else return 0; } /* * 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. */ static 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 optlen; optlen = opt->m_len - sizeof(p->ipopt_dst); if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET) return (m); /* XXX should fail */ if (!in_nullhost(p->ipopt_dst)) ip->ip_dst = p->ipopt_dst; if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) { MGETHDR(n, M_DONTWAIT, MT_HEADER); if (n == 0) return (m); MCLAIM(n, m->m_owner); M_COPY_PKTHDR(n, m); m_tag_delete_chain(m, NULL); m->m_flags &= ~M_PKTHDR; 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; memmove(mtod(m, caddr_t), ip, sizeof(struct ip)); } m->m_pkthdr.len += optlen; 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(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, (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(int op, struct socket *so, int level, int optname, struct mbuf **mp) { struct inpcb *inp = sotoinpcb(so); struct mbuf *m = *mp; int optval = 0; int error = 0; #if defined(IPSEC) || defined(FAST_IPSEC) struct proc *p = curproc; /*XXX*/ #endif 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_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: 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: inp->inp_ip.ip_ttl = optval; 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; } } 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); 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: case IP_PORTRANGE_HIGH: inp->inp_flags &= ~(INP_LOWPORT); break; case IP_PORTRANGE_LOW: inp->inp_flags |= INP_LOWPORT; break; default: error = EINVAL; break; } } break; #if defined(IPSEC) || defined(FAST_IPSEC) case IP_IPSEC_POLICY: { caddr_t req = NULL; size_t len = 0; int priv = 0; #ifdef __NetBSD__ if (p == 0 || suser(p->p_ucred, &p->p_acflag)) priv = 0; else priv = 1; #else priv = (in6p->in6p_socket->so_state & SS_PRIV); #endif if (m) { req = mtod(m, caddr_t); len = m->m_len; } error = ipsec4_set_policy(inp, optname, req, len, priv); break; } #endif /*IPSEC*/ 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); MCLAIM(m, so->so_mowner); 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_RECVOPTS: case IP_RECVRETOPTS: case IP_RECVDSTADDR: case IP_RECVIF: case IP_ERRORMTU: *mp = m = m_get(M_WAIT, MT_SOOPTS); MCLAIM(m, so->so_mowner); 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_ERRORMTU: optval = inp->inp_errormtu; 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; } *mtod(m, int *) = optval; break; #if 0 /* defined(IPSEC) || defined(FAST_IPSEC) */ /* XXX: code broken */ case IP_IPSEC_POLICY: { caddr_t req = NULL; size_t len = 0; if (m) { req = mtod(m, caddr_t); len = m->m_len; } error = ipsec4_get_policy(inp, req, len, mp); break; } #endif /*IPSEC*/ 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); if (*mp) MCLAIM(*mp, so->so_mowner); break; case IP_PORTRANGE: *mp = m = m_get(M_WAIT, MT_SOOPTS); MCLAIM(m, so->so_mowner); m->m_len = sizeof(int); if (inp->inp_flags & INP_LOWPORT) optval = IP_PORTRANGE_LOW; else optval = IP_PORTRANGE_DEFAULT; *mtod(m, int *) = optval; 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(int optname, struct mbuf **pcbopt, struct mbuf *m) #else ip_pcbopts(struct mbuf **pcbopt, struct mbuf *m) #endif { 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); } #ifndef __vax__ if (m->m_len % sizeof(int32_t)) goto bad; #endif /* * 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(cp, mtod(m, caddr_t), (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. */ (void)memmove(&cp[IPOPT_OFFSET+1], &cp[IPOPT_OFFSET+1] + sizeof(struct in_addr), (unsigned)cnt - (IPOPT_MINOFF - 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); } /* * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index. */ static struct ifnet * ip_multicast_if(struct in_addr *a, int *ifindexp) { int ifindex; struct ifnet *ifp = NULL; struct in_ifaddr *ia; if (ifindexp) *ifindexp = 0; if (ntohl(a->s_addr) >> 24 == 0) { ifindex = ntohl(a->s_addr) & 0xffffff; if (ifindex < 0 || if_indexlim <= ifindex) return NULL; ifp = ifindex2ifnet[ifindex]; if (!ifp) return NULL; if (ifindexp) *ifindexp = ifindex; } else { LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) { if (in_hosteq(ia->ia_addr.sin_addr, *a) && (ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) { ifp = ia->ia_ifp; break; } } } return ifp; } /* * Set the IP multicast options in response to user setsockopt(). */ int ip_setmoptions(int optname, struct ip_moptions **imop, struct mbuf *m) { 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 route ro; struct sockaddr_in *dst; int ifindex; 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); if (imo == NULL) return (ENOBUFS); *imop = imo; imo->imo_multicast_ifp = NULL; imo->imo_multicast_addr.s_addr = INADDR_ANY; imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL; imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP; imo->imo_num_memberships = 0; } 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 (in_nullhost(addr)) { 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. */ ifp = ip_multicast_if(&addr, &ifindex); if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { error = EADDRNOTAVAIL; break; } imo->imo_multicast_ifp = ifp; if (ifindex) imo->imo_multicast_addr = addr; else imo->imo_multicast_addr.s_addr = INADDR_ANY; 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 (in_nullhost(mreq->imr_interface)) { bzero((caddr_t)&ro, sizeof(ro)); 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; rtalloc(&ro); if (ro.ro_rt == NULL) { error = EADDRNOTAVAIL; break; } ifp = ro.ro_rt->rt_ifp; rtfree(ro.ro_rt); } else { ifp = ip_multicast_if(&mreq->imr_interface, NULL); } /* * 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_ifp == ifp && in_hosteq(imo->imo_membership[i]->inm_addr, mreq->imr_multiaddr)) break; } if (i < imo->imo_num_memberships) { error = EADDRINUSE; break; } if (i == IP_MAX_MEMBERSHIPS) { 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 (in_nullhost(mreq->imr_interface)) ifp = NULL; else { ifp = ip_multicast_if(&mreq->imr_interface, NULL); 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_ifp == ifp) && in_hosteq(imo->imo_membership[i]->inm_addr, mreq->imr_multiaddr)) 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 mbuf. */ 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(*imop, M_IPMOPTS); *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; *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 = zeroin_addr; else if (imo->imo_multicast_addr.s_addr) { /* return the value user has set */ *addr = imo->imo_multicast_addr; } else { IFP_TO_IA(imo->imo_multicast_ifp, ia); *addr = ia ? ia->ia_addr.sin_addr : zeroin_addr; } return (0); case IP_MULTICAST_TTL: ttl = mtod(*mp, u_char *); (*mp)->m_len = 1; *ttl = imo ? imo->imo_multicast_ttl : IP_DEFAULT_MULTICAST_TTL; return (0); case IP_MULTICAST_LOOP: loop = mtod(*mp, u_char *); (*mp)->m_len = 1; *loop = imo ? imo->imo_multicast_loop : IP_DEFAULT_MULTICAST_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, 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 lo0ifp -- easier than replicating that code here. */ static void ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst) { struct ip *ip; struct mbuf *copym; copym = m_copy(m, 0, M_COPYALL); if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip))) copym = m_pullup(copym, sizeof(struct ip)); 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 *); if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) { in_delayed_cksum(copym); copym->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4); } ip->ip_sum = 0; ip->ip_sum = in_cksum(copym, ip->ip_hl << 2); (void) looutput(ifp, copym, sintosa(dst), NULL); } }