/* $NetBSD: ip6_output.c,v 1.58 2002/09/23 13:28:55 itojun Exp $ */ /* $KAME: ip6_output.c,v 1.172 2001/03/25 09:55:56 itojun 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) 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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: ip6_output.c,v 1.58 2002/09/23 13:28:55 itojun Exp $"); #include "opt_inet.h" #include "opt_ipsec.h" #include "opt_pfil_hooks.h" #include #include #include #include #include #include #include #include #include #include #include #ifdef PFIL_HOOKS #include #endif #include #include #include #include #include #include #include #ifdef IPSEC #include #include #endif /* IPSEC */ #include "loop.h" #include #ifdef PFIL_HOOKS extern struct pfil_head inet6_pfil_hook; /* XXX */ #endif struct ip6_exthdrs { struct mbuf *ip6e_ip6; struct mbuf *ip6e_hbh; struct mbuf *ip6e_dest1; struct mbuf *ip6e_rthdr; struct mbuf *ip6e_dest2; }; static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *, struct socket *)); static int ip6_setmoptions __P((int, struct ip6_moptions **, struct mbuf *)); static int ip6_getmoptions __P((int, struct ip6_moptions *, struct mbuf **)); static int ip6_copyexthdr __P((struct mbuf **, caddr_t, int)); static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int, struct ip6_frag **)); static int ip6_insert_jumboopt __P((struct ip6_exthdrs *, u_int32_t)); static int ip6_splithdr __P((struct mbuf *, struct ip6_exthdrs *)); static int ip6_getpmtu __P((struct route_in6 *, struct route_in6 *, struct ifnet *, struct in6_addr *, u_long *)); extern struct ifnet loif[NLOOP]; /* * IP6 output. The packet in mbuf chain m contains a skeletal IP6 * header (with pri, len, nxt, hlim, src, dst). * This function may modify ver and hlim only. * The mbuf chain containing the packet will be freed. * The mbuf opt, if present, will not be freed. * * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and * nd_ifinfo.linkmtu is u_int32_t. so we use u_long to hold largest one, * which is rt_rmx.rmx_mtu. */ int ip6_output(m0, opt, ro, flags, im6o, ifpp) struct mbuf *m0; struct ip6_pktopts *opt; struct route_in6 *ro; int flags; struct ip6_moptions *im6o; struct ifnet **ifpp; /* XXX: just for statistics */ { struct ip6_hdr *ip6, *mhip6; struct ifnet *ifp, *origifp; struct mbuf *m = m0; int hlen, tlen, len, off; struct route_in6 ip6route; struct sockaddr_in6 *dst; int error = 0; struct in6_ifaddr *ia; u_long mtu; u_int32_t optlen = 0, plen = 0, unfragpartlen = 0; struct ip6_exthdrs exthdrs; struct in6_addr finaldst; struct route_in6 *ro_pmtu = NULL; int hdrsplit = 0; int needipsec = 0; #ifdef IPSEC int needipsectun = 0; struct socket *so; struct secpolicy *sp = NULL; /* for AH processing. stupid to have "socket" variable in IP layer... */ so = ipsec_getsocket(m); (void)ipsec_setsocket(m, NULL); ip6 = mtod(m, struct ip6_hdr *); #endif /* IPSEC */ #define MAKE_EXTHDR(hp, mp) \ do { \ if (hp) { \ struct ip6_ext *eh = (struct ip6_ext *)(hp); \ error = ip6_copyexthdr((mp), (caddr_t)(hp), \ ((eh)->ip6e_len + 1) << 3); \ if (error) \ goto freehdrs; \ } \ } while (0) bzero(&exthdrs, sizeof(exthdrs)); if (opt) { /* Hop-by-Hop options header */ MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh); /* Destination options header(1st part) */ MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1); /* Routing header */ MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr); /* Destination options header(2nd part) */ MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2); } #ifdef IPSEC /* get a security policy for this packet */ if (so == NULL) sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error); else sp = ipsec6_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error); if (sp == NULL) { ipsec6stat.out_inval++; goto freehdrs; } error = 0; /* check policy */ switch (sp->policy) { case IPSEC_POLICY_DISCARD: /* * This packet is just discarded. */ ipsec6stat.out_polvio++; goto freehdrs; case IPSEC_POLICY_BYPASS: case IPSEC_POLICY_NONE: /* no need to do IPsec. */ needipsec = 0; break; case IPSEC_POLICY_IPSEC: if (sp->req == NULL) { /* XXX should be panic ? */ printf("ip6_output: No IPsec request specified.\n"); error = EINVAL; goto freehdrs; } needipsec = 1; break; case IPSEC_POLICY_ENTRUST: default: printf("ip6_output: Invalid policy found. %d\n", sp->policy); } #endif /* IPSEC */ /* * Calculate the total length of the extension header chain. * Keep the length of the unfragmentable part for fragmentation. */ optlen = 0; if (exthdrs.ip6e_hbh) optlen += exthdrs.ip6e_hbh->m_len; if (exthdrs.ip6e_dest1) optlen += exthdrs.ip6e_dest1->m_len; if (exthdrs.ip6e_rthdr) optlen += exthdrs.ip6e_rthdr->m_len; unfragpartlen = optlen + sizeof(struct ip6_hdr); /* NOTE: we don't add AH/ESP length here. do that later. */ if (exthdrs.ip6e_dest2) optlen += exthdrs.ip6e_dest2->m_len; /* * If we need IPsec, or there is at least one extension header, * separate IP6 header from the payload. */ if ((needipsec || optlen) && !hdrsplit) { if ((error = ip6_splithdr(m, &exthdrs)) != 0) { m = NULL; goto freehdrs; } m = exthdrs.ip6e_ip6; hdrsplit++; } /* adjust pointer */ ip6 = mtod(m, struct ip6_hdr *); /* adjust mbuf packet header length */ m->m_pkthdr.len += optlen; plen = m->m_pkthdr.len - sizeof(*ip6); /* If this is a jumbo payload, insert a jumbo payload option. */ if (plen > IPV6_MAXPACKET) { if (!hdrsplit) { if ((error = ip6_splithdr(m, &exthdrs)) != 0) { m = NULL; goto freehdrs; } m = exthdrs.ip6e_ip6; hdrsplit++; } /* adjust pointer */ ip6 = mtod(m, struct ip6_hdr *); if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0) goto freehdrs; ip6->ip6_plen = 0; } else ip6->ip6_plen = htons(plen); /* * Concatenate headers and fill in next header fields. * Here we have, on "m" * IPv6 payload * and we insert headers accordingly. Finally, we should be getting: * IPv6 hbh dest1 rthdr ah* [esp* dest2 payload] * * during the header composing process, "m" points to IPv6 header. * "mprev" points to an extension header prior to esp. */ { u_char *nexthdrp = &ip6->ip6_nxt; struct mbuf *mprev = m; /* * we treat dest2 specially. this makes IPsec processing * much easier. * * result: IPv6 dest2 payload * m and mprev will point to IPv6 header. */ if (exthdrs.ip6e_dest2) { if (!hdrsplit) panic("assumption failed: hdr not split"); exthdrs.ip6e_dest2->m_next = m->m_next; m->m_next = exthdrs.ip6e_dest2; *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt; ip6->ip6_nxt = IPPROTO_DSTOPTS; } #define MAKE_CHAIN(m, mp, p, i)\ do {\ if (m) {\ if (!hdrsplit) \ panic("assumption failed: hdr not split"); \ *mtod((m), u_char *) = *(p);\ *(p) = (i);\ p = mtod((m), u_char *);\ (m)->m_next = (mp)->m_next;\ (mp)->m_next = (m);\ (mp) = (m);\ }\ } while (0) /* * result: IPv6 hbh dest1 rthdr dest2 payload * m will point to IPv6 header. mprev will point to the * extension header prior to dest2 (rthdr in the above case). */ MAKE_CHAIN(exthdrs.ip6e_hbh, mprev, nexthdrp, IPPROTO_HOPOPTS); MAKE_CHAIN(exthdrs.ip6e_dest1, mprev, nexthdrp, IPPROTO_DSTOPTS); MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev, nexthdrp, IPPROTO_ROUTING); #ifdef IPSEC if (!needipsec) goto skip_ipsec2; /* * pointers after IPsec headers are not valid any more. * other pointers need a great care too. * (IPsec routines should not mangle mbufs prior to AH/ESP) */ exthdrs.ip6e_dest2 = NULL; { struct ip6_rthdr *rh = NULL; int segleft_org = 0; struct ipsec_output_state state; if (exthdrs.ip6e_rthdr) { rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *); segleft_org = rh->ip6r_segleft; rh->ip6r_segleft = 0; } bzero(&state, sizeof(state)); state.m = m; error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags, &needipsectun); m = state.m; if (error) { /* mbuf is already reclaimed in ipsec6_output_trans. */ m = NULL; switch (error) { case EHOSTUNREACH: case ENETUNREACH: case EMSGSIZE: case ENOBUFS: case ENOMEM: break; default: printf("ip6_output (ipsec): error code %d\n", error); /* FALLTHROUGH */ case ENOENT: /* don't show these error codes to the user */ error = 0; break; } goto bad; } if (exthdrs.ip6e_rthdr) { /* ah6_output doesn't modify mbuf chain */ rh->ip6r_segleft = segleft_org; } } skip_ipsec2:; #endif } /* * If there is a routing header, replace destination address field * with the first hop of the routing header. */ if (exthdrs.ip6e_rthdr) { struct ip6_rthdr *rh; struct ip6_rthdr0 *rh0; rh = (struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *)); finaldst = ip6->ip6_dst; switch (rh->ip6r_type) { case IPV6_RTHDR_TYPE_0: rh0 = (struct ip6_rthdr0 *)rh; ip6->ip6_dst = rh0->ip6r0_addr[0]; bcopy((caddr_t)&rh0->ip6r0_addr[1], (caddr_t)&rh0->ip6r0_addr[0], sizeof(struct in6_addr) * (rh0->ip6r0_segleft - 1)); rh0->ip6r0_addr[rh0->ip6r0_segleft - 1] = finaldst; break; default: /* is it possible? */ error = EINVAL; goto bad; } } /* Source address validation */ if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && (flags & IPV6_UNSPECSRC) == 0) { error = EOPNOTSUPP; ip6stat.ip6s_badscope++; goto bad; } if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) { error = EOPNOTSUPP; ip6stat.ip6s_badscope++; goto bad; } ip6stat.ip6s_localout++; /* * Route packet. */ if (ro == 0) { ro = &ip6route; bzero((caddr_t)ro, sizeof(*ro)); } ro_pmtu = ro; if (opt && opt->ip6po_rthdr) ro = &opt->ip6po_route; dst = (struct sockaddr_in6 *)&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->sin6_family != AF_INET6 || !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_dst))) { RTFREE(ro->ro_rt); ro->ro_rt = (struct rtentry *)0; } if (ro->ro_rt == 0) { bzero(dst, sizeof(*dst)); dst->sin6_family = AF_INET6; dst->sin6_len = sizeof(struct sockaddr_in6); dst->sin6_addr = ip6->ip6_dst; } #ifdef IPSEC if (needipsec && needipsectun) { struct ipsec_output_state state; /* * All the extension headers will become inaccessible * (since they can be encrypted). * Don't panic, we need no more updates to extension headers * on inner IPv6 packet (since they are now encapsulated). * * IPv6 [ESP|AH] IPv6 [extension headers] payload */ bzero(&exthdrs, sizeof(exthdrs)); exthdrs.ip6e_ip6 = m; bzero(&state, sizeof(state)); state.m = m; state.ro = (struct route *)ro; state.dst = (struct sockaddr *)dst; error = ipsec6_output_tunnel(&state, sp, flags); m = state.m; ro = (struct route_in6 *)state.ro; dst = (struct sockaddr_in6 *)state.dst; if (error) { /* mbuf is already reclaimed in ipsec6_output_tunnel. */ m0 = m = NULL; m = NULL; switch (error) { case EHOSTUNREACH: case ENETUNREACH: case EMSGSIZE: case ENOBUFS: case ENOMEM: break; default: printf("ip6_output (ipsec): error code %d\n", error); /* FALLTHROUGH */ case ENOENT: /* don't show these error codes to the user */ error = 0; break; } goto bad; } exthdrs.ip6e_ip6 = m; } #endif /* IPSEC */ if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { /* Unicast */ #define ifatoia6(ifa) ((struct in6_ifaddr *)(ifa)) #define sin6tosa(sin6) ((struct sockaddr *)(sin6)) /* xxx * interface selection comes here * if an interface is specified from an upper layer, * ifp must point it. */ if (ro->ro_rt == 0) { /* * non-bsdi always clone routes, if parent is * PRF_CLONING. */ rtalloc((struct route *)ro); } if (ro->ro_rt == 0) { ip6stat.ip6s_noroute++; error = EHOSTUNREACH; /* XXX in6_ifstat_inc(ifp, ifs6_out_discard); */ goto bad; } ia = ifatoia6(ro->ro_rt->rt_ifa); ifp = ro->ro_rt->rt_ifp; ro->ro_rt->rt_use++; if (ro->ro_rt->rt_flags & RTF_GATEWAY) dst = (struct sockaddr_in6 *)ro->ro_rt->rt_gateway; m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */ in6_ifstat_inc(ifp, ifs6_out_request); /* * Check if the outgoing interface conflicts with * the interface specified by ifi6_ifindex (if specified). * Note that loopback interface is always okay. * (this may happen when we are sending a packet to one of * our own addresses.) */ if (opt && opt->ip6po_pktinfo && opt->ip6po_pktinfo->ipi6_ifindex) { if (!(ifp->if_flags & IFF_LOOPBACK) && ifp->if_index != opt->ip6po_pktinfo->ipi6_ifindex) { ip6stat.ip6s_noroute++; in6_ifstat_inc(ifp, ifs6_out_discard); error = EHOSTUNREACH; goto bad; } } if (opt && opt->ip6po_hlim != -1) ip6->ip6_hlim = opt->ip6po_hlim & 0xff; } else { /* Multicast */ struct in6_multi *in6m; m->m_flags = (m->m_flags & ~M_BCAST) | M_MCAST; /* * See if the caller provided any multicast options */ ifp = NULL; if (im6o != NULL) { ip6->ip6_hlim = im6o->im6o_multicast_hlim; if (im6o->im6o_multicast_ifp != NULL) ifp = im6o->im6o_multicast_ifp; } else ip6->ip6_hlim = ip6_defmcasthlim; /* * See if the caller provided the outgoing interface * as an ancillary data. * Boundary check for ifindex is assumed to be already done. */ if (opt && opt->ip6po_pktinfo && opt->ip6po_pktinfo->ipi6_ifindex) ifp = ifindex2ifnet[opt->ip6po_pktinfo->ipi6_ifindex]; /* * If the destination is a node-local scope multicast, * the packet should be loop-backed only. */ if (IN6_IS_ADDR_MC_NODELOCAL(&ip6->ip6_dst)) { /* * If the outgoing interface is already specified, * it should be a loopback interface. */ if (ifp && (ifp->if_flags & IFF_LOOPBACK) == 0) { ip6stat.ip6s_badscope++; error = ENETUNREACH; /* XXX: better error? */ /* XXX correct ifp? */ in6_ifstat_inc(ifp, ifs6_out_discard); goto bad; } else { ifp = &loif[0]; } } if (opt && opt->ip6po_hlim != -1) ip6->ip6_hlim = opt->ip6po_hlim & 0xff; /* * If caller did not provide an interface lookup a * default in the routing table. This is either a * default for the speicfied group (i.e. a host * route), or a multicast default (a route for the * ``net'' ff00::/8). */ if (ifp == NULL) { if (ro->ro_rt == 0) { ro->ro_rt = rtalloc1((struct sockaddr *) &ro->ro_dst, 0); } if (ro->ro_rt == 0) { ip6stat.ip6s_noroute++; error = EHOSTUNREACH; /* XXX in6_ifstat_inc(ifp, ifs6_out_discard) */ goto bad; } ia = ifatoia6(ro->ro_rt->rt_ifa); ifp = ro->ro_rt->rt_ifp; ro->ro_rt->rt_use++; } if ((flags & IPV6_FORWARDING) == 0) in6_ifstat_inc(ifp, ifs6_out_request); in6_ifstat_inc(ifp, ifs6_out_mcast); /* * Confirm that the outgoing interface supports multicast. */ if ((ifp->if_flags & IFF_MULTICAST) == 0) { ip6stat.ip6s_noroute++; in6_ifstat_inc(ifp, ifs6_out_discard); error = ENETUNREACH; goto bad; } IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m); if (in6m != NULL && (im6o == NULL || im6o->im6o_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. */ ip6_mloopback(ifp, m, dst); } 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 * IPV6_FORWARDING flag to prevent infinite recursion. * * Multicasts that are looped back by ip6_mloopback(), * above, will be forwarded by the ip6_input() routine, * if necessary. */ if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) { if (ip6_mforward(ip6, ifp, m) != 0) { m_freem(m); goto done; } } } /* * Multicasts with a hoplimit 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 ip6_mloopback() will * loop back a copy if this host actually belongs to the * destination group on the loopback interface. */ if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK)) { m_freem(m); goto done; } } /* * Fill the outgoing inteface to tell the upper layer * to increment per-interface statistics. */ if (ifpp) *ifpp = ifp; /* Determine path MTU. */ if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu)) != 0) goto bad; /* * The caller of this function may specify to use the minimum MTU * in some cases. */ if (mtu > IPV6_MMTU) { if ((flags & IPV6_MINMTU)) mtu = IPV6_MMTU; } /* Fake scoped addresses */ if ((ifp->if_flags & IFF_LOOPBACK) != 0) { /* * If source or destination address is a scoped address, and * the packet is going to be sent to a loopback interface, * we should keep the original interface. */ /* * XXX: this is a very experimental and temporary solution. * We eventually have sockaddr_in6 and use the sin6_scope_id * field of the structure here. * We rely on the consistency between two scope zone ids * of source add destination, which should already be assured * Larger scopes than link will be supported in the near * future. */ origifp = NULL; if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) origifp = ifindex2ifnet[ntohs(ip6->ip6_src.s6_addr16[1])]; else if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) origifp = ifindex2ifnet[ntohs(ip6->ip6_dst.s6_addr16[1])]; /* * XXX: origifp can be NULL even in those two cases above. * For example, if we remove the (only) link-local address * from the loopback interface, and try to send a link-local * address without link-id information. Then the source * address is ::1, and the destination address is the * link-local address with its s6_addr16[1] being zero. * What is worse, if the packet goes to the loopback interface * by a default rejected route, the null pointer would be * passed to looutput, and the kernel would hang. * The following last resort would prevent such disaster. */ if (origifp == NULL) origifp = ifp; } else origifp = ifp; if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) ip6->ip6_src.s6_addr16[1] = 0; if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) ip6->ip6_dst.s6_addr16[1] = 0; /* * If the outgoing packet contains a hop-by-hop options header, * it must be examined and processed even by the source node. * (RFC 2460, section 4.) */ if (exthdrs.ip6e_hbh) { struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *); u_int32_t dummy1; /* XXX unused */ u_int32_t dummy2; /* XXX unused */ /* * XXX: if we have to send an ICMPv6 error to the sender, * we need the M_LOOP flag since icmp6_error() expects * the IPv6 and the hop-by-hop options header are * continuous unless the flag is set. */ m->m_flags |= M_LOOP; m->m_pkthdr.rcvif = ifp; if (ip6_process_hopopts(m, (u_int8_t *)(hbh + 1), ((hbh->ip6h_len + 1) << 3) - sizeof(struct ip6_hbh), &dummy1, &dummy2) < 0) { /* m was already freed at this point */ error = EINVAL;/* better error? */ goto done; } m->m_flags &= ~M_LOOP; /* XXX */ m->m_pkthdr.rcvif = NULL; } #ifdef PFIL_HOOKS /* * Run through list of hooks for output packets. */ if ((error = pfil_run_hooks(&inet6_pfil_hook, &m, ifp, PFIL_OUT)) != 0) goto done; if (m == NULL) goto done; ip6 = mtod(m, struct ip6_hdr *); #endif /* PFIL_HOOKS */ /* * Send the packet to the outgoing interface. * If necessary, do IPv6 fragmentation before sending. */ tlen = m->m_pkthdr.len; if (tlen <= mtu) { #ifdef IFA_STATS struct in6_ifaddr *ia6; ip6 = mtod(m, struct ip6_hdr *); ia6 = in6_ifawithifp(ifp, &ip6->ip6_src); if (ia6) { /* Record statistics for this interface address. */ ia6->ia_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len; } #endif #ifdef IPSEC /* clean ipsec history once it goes out of the node */ ipsec_delaux(m); #endif error = nd6_output(ifp, origifp, m, dst, ro->ro_rt); goto done; } else if (mtu < IPV6_MMTU) { /* * note that path MTU is never less than IPV6_MMTU * (see icmp6_input). */ error = EMSGSIZE; in6_ifstat_inc(ifp, ifs6_out_fragfail); goto bad; } else if (ip6->ip6_plen == 0) { /* jumbo payload cannot be fragmented */ error = EMSGSIZE; in6_ifstat_inc(ifp, ifs6_out_fragfail); goto bad; } else { struct mbuf **mnext, *m_frgpart; struct ip6_frag *ip6f; u_int32_t id = htonl(ip6_id++); u_char nextproto; /* * Too large for the destination or interface; * fragment if possible. * Must be able to put at least 8 bytes per fragment. */ hlen = unfragpartlen; if (mtu > IPV6_MAXPACKET) mtu = IPV6_MAXPACKET; len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7; if (len < 8) { error = EMSGSIZE; in6_ifstat_inc(ifp, ifs6_out_fragfail); goto bad; } mnext = &m->m_nextpkt; /* * Change the next header field of the last header in the * unfragmentable part. */ if (exthdrs.ip6e_rthdr) { nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *); *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT; } else if (exthdrs.ip6e_dest1) { nextproto = *mtod(exthdrs.ip6e_dest1, u_char *); *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT; } else if (exthdrs.ip6e_hbh) { nextproto = *mtod(exthdrs.ip6e_hbh, u_char *); *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT; } else { nextproto = ip6->ip6_nxt; ip6->ip6_nxt = IPPROTO_FRAGMENT; } /* * Loop through length of segment after first fragment, * make new header and copy data of each part and link onto * chain. */ m0 = m; for (off = hlen; off < tlen; off += len) { MGETHDR(m, M_DONTWAIT, MT_HEADER); if (!m) { error = ENOBUFS; ip6stat.ip6s_odropped++; goto sendorfree; } m->m_flags = m0->m_flags & M_COPYFLAGS; *mnext = m; mnext = &m->m_nextpkt; m->m_data += max_linkhdr; mhip6 = mtod(m, struct ip6_hdr *); *mhip6 = *ip6; m->m_len = sizeof(*mhip6); error = ip6_insertfraghdr(m0, m, hlen, &ip6f); if (error) { ip6stat.ip6s_odropped++; goto sendorfree; } ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7)); if (off + len >= tlen) len = tlen - off; else ip6f->ip6f_offlg |= IP6F_MORE_FRAG; mhip6->ip6_plen = htons((u_short)(len + hlen + sizeof(*ip6f) - sizeof(struct ip6_hdr))); if ((m_frgpart = m_copy(m0, off, len)) == 0) { error = ENOBUFS; ip6stat.ip6s_odropped++; goto sendorfree; } m_cat(m, m_frgpart); m->m_pkthdr.len = len + hlen + sizeof(*ip6f); m->m_pkthdr.rcvif = (struct ifnet *)0; ip6f->ip6f_reserved = 0; ip6f->ip6f_ident = id; ip6f->ip6f_nxt = nextproto; ip6stat.ip6s_ofragments++; in6_ifstat_inc(ifp, ifs6_out_fragcreat); } in6_ifstat_inc(ifp, ifs6_out_fragok); } /* * Remove leading garbages. */ sendorfree: m = m0->m_nextpkt; m0->m_nextpkt = 0; m_freem(m0); for (m0 = m; m; m = m0) { m0 = m->m_nextpkt; m->m_nextpkt = 0; if (error == 0) { #ifdef IFA_STATS struct in6_ifaddr *ia6; ip6 = mtod(m, struct ip6_hdr *); ia6 = in6_ifawithifp(ifp, &ip6->ip6_src); if (ia6) { /* * Record statistics for this interface * address. */ ia6->ia_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len; } #endif #ifdef IPSEC /* clean ipsec history once it goes out of the node */ ipsec_delaux(m); #endif error = nd6_output(ifp, origifp, m, dst, ro->ro_rt); } else m_freem(m); } if (error == 0) ip6stat.ip6s_fragmented++; done: if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */ RTFREE(ro->ro_rt); } else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) { RTFREE(ro_pmtu->ro_rt); } #ifdef IPSEC if (sp != NULL) key_freesp(sp); #endif /* IPSEC */ return (error); freehdrs: m_freem(exthdrs.ip6e_hbh); /* m_freem will check if mbuf is 0 */ m_freem(exthdrs.ip6e_dest1); m_freem(exthdrs.ip6e_rthdr); m_freem(exthdrs.ip6e_dest2); /* FALLTHROUGH */ bad: m_freem(m); goto done; } static int ip6_copyexthdr(mp, hdr, hlen) struct mbuf **mp; caddr_t hdr; int hlen; { struct mbuf *m; if (hlen > MCLBYTES) return (ENOBUFS); /* XXX */ MGET(m, M_DONTWAIT, MT_DATA); if (!m) return (ENOBUFS); if (hlen > MLEN) { MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { m_free(m); return (ENOBUFS); } } m->m_len = hlen; if (hdr) bcopy(hdr, mtod(m, caddr_t), hlen); *mp = m; return (0); } /* * Insert jumbo payload option. */ static int ip6_insert_jumboopt(exthdrs, plen) struct ip6_exthdrs *exthdrs; u_int32_t plen; { struct mbuf *mopt; u_int8_t *optbuf; u_int32_t v; #define JUMBOOPTLEN 8 /* length of jumbo payload option and padding */ /* * If there is no hop-by-hop options header, allocate new one. * If there is one but it doesn't have enough space to store the * jumbo payload option, allocate a cluster to store the whole options. * Otherwise, use it to store the options. */ if (exthdrs->ip6e_hbh == 0) { MGET(mopt, M_DONTWAIT, MT_DATA); if (mopt == 0) return (ENOBUFS); mopt->m_len = JUMBOOPTLEN; optbuf = mtod(mopt, u_int8_t *); optbuf[1] = 0; /* = ((JUMBOOPTLEN) >> 3) - 1 */ exthdrs->ip6e_hbh = mopt; } else { struct ip6_hbh *hbh; mopt = exthdrs->ip6e_hbh; if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) { /* * XXX assumption: * - exthdrs->ip6e_hbh is not referenced from places * other than exthdrs. * - exthdrs->ip6e_hbh is not an mbuf chain. */ int oldoptlen = mopt->m_len; struct mbuf *n; /* * XXX: give up if the whole (new) hbh header does * not fit even in an mbuf cluster. */ if (oldoptlen + JUMBOOPTLEN > MCLBYTES) return (ENOBUFS); /* * As a consequence, we must always prepare a cluster * at this point. */ MGET(n, M_DONTWAIT, MT_DATA); if (n) { MCLGET(n, M_DONTWAIT); if ((n->m_flags & M_EXT) == 0) { m_freem(n); n = NULL; } } if (!n) return (ENOBUFS); n->m_len = oldoptlen + JUMBOOPTLEN; bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t), oldoptlen); optbuf = mtod(n, u_int8_t *) + oldoptlen; m_freem(mopt); mopt = exthdrs->ip6e_hbh = n; } else { optbuf = mtod(mopt, u_int8_t *) + mopt->m_len; mopt->m_len += JUMBOOPTLEN; } optbuf[0] = IP6OPT_PADN; optbuf[1] = 0; /* * Adjust the header length according to the pad and * the jumbo payload option. */ hbh = mtod(mopt, struct ip6_hbh *); hbh->ip6h_len += (JUMBOOPTLEN >> 3); } /* fill in the option. */ optbuf[2] = IP6OPT_JUMBO; optbuf[3] = 4; v = (u_int32_t)htonl(plen + JUMBOOPTLEN); bcopy(&v, &optbuf[4], sizeof(u_int32_t)); /* finally, adjust the packet header length */ exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN; return (0); #undef JUMBOOPTLEN } /* * Insert fragment header and copy unfragmentable header portions. */ static int ip6_insertfraghdr(m0, m, hlen, frghdrp) struct mbuf *m0, *m; int hlen; struct ip6_frag **frghdrp; { struct mbuf *n, *mlast; if (hlen > sizeof(struct ip6_hdr)) { n = m_copym(m0, sizeof(struct ip6_hdr), hlen - sizeof(struct ip6_hdr), M_DONTWAIT); if (n == 0) return (ENOBUFS); m->m_next = n; } else n = m; /* Search for the last mbuf of unfragmentable part. */ for (mlast = n; mlast->m_next; mlast = mlast->m_next) ; if ((mlast->m_flags & M_EXT) == 0 && M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) { /* use the trailing space of the last mbuf for the fragment hdr */ *frghdrp = (struct ip6_frag *)(mtod(mlast, caddr_t) + mlast->m_len); mlast->m_len += sizeof(struct ip6_frag); m->m_pkthdr.len += sizeof(struct ip6_frag); } else { /* allocate a new mbuf for the fragment header */ struct mbuf *mfrg; MGET(mfrg, M_DONTWAIT, MT_DATA); if (mfrg == 0) return (ENOBUFS); mfrg->m_len = sizeof(struct ip6_frag); *frghdrp = mtod(mfrg, struct ip6_frag *); mlast->m_next = mfrg; } return (0); } static int ip6_getpmtu(ro_pmtu, ro, ifp, dst, mtup) struct route_in6 *ro_pmtu, *ro; struct ifnet *ifp; struct in6_addr *dst; u_long *mtup; { u_int32_t mtu = 0; int error = 0; if (ro_pmtu != ro) { /* The first hop and the final destination may differ. */ struct sockaddr_in6 *sa6_dst = (struct sockaddr_in6 *)&ro_pmtu->ro_dst; if (ro_pmtu->ro_rt && ((ro_pmtu->ro_rt->rt_flags & RTF_UP) == 0 || !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr, dst))) { RTFREE(ro_pmtu->ro_rt); ro_pmtu->ro_rt = (struct rtentry *)0; } if (ro_pmtu->ro_rt == 0) { bzero(sa6_dst, sizeof(*sa6_dst)); sa6_dst->sin6_family = AF_INET6; sa6_dst->sin6_len = sizeof(struct sockaddr_in6); sa6_dst->sin6_addr = *dst; rtalloc((struct route *)ro_pmtu); } } if (ro_pmtu->ro_rt) { u_int32_t ifmtu; if (ifp == NULL) ifp = ro_pmtu->ro_rt->rt_ifp; ifmtu = IN6_LINKMTU(ifp); mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu; if (mtu == 0) mtu = ifmtu; else if (mtu > ifmtu) { /* * The MTU on the route is larger than the MTU on * the interface! This shouldn't happen, unless the * MTU of the interface has been changed after the * interface was brought up. Change the MTU in the * route to match the interface MTU (as long as the * field isn't locked). * * if MTU on the route is 0, we need to fix the MTU. * this case happens with path MTU discovery timeouts. */ mtu = ifmtu; if (!(ro_pmtu->ro_rt->rt_rmx.rmx_locks & RTV_MTU)) ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu; } } else if (ifp) { mtu = IN6_LINKMTU(ifp); } else error = EHOSTUNREACH; /* XXX */ *mtup = mtu; return (error); } /* * IP6 socket option processing. */ int ip6_ctloutput(op, so, level, optname, mp) int op; struct socket *so; int level, optname; struct mbuf **mp; { struct in6pcb *in6p = sotoin6pcb(so); struct mbuf *m = *mp; int optval = 0; int error = 0; struct proc *p = curproc; /* XXX */ if (level == IPPROTO_IPV6) { switch (op) { case PRCO_SETOPT: switch (optname) { case IPV6_PKTOPTIONS: /* m is freed in ip6_pcbopts */ return (ip6_pcbopts(&in6p->in6p_outputopts, m, so)); case IPV6_HOPOPTS: case IPV6_DSTOPTS: if (p == 0 || suser(p->p_ucred, &p->p_acflag)) { error = EPERM; break; } /* FALLTHROUGH */ case IPV6_UNICAST_HOPS: case IPV6_RECVOPTS: case IPV6_RECVRETOPTS: case IPV6_RECVDSTADDR: case IPV6_PKTINFO: case IPV6_HOPLIMIT: case IPV6_RTHDR: case IPV6_FAITH: case IPV6_V6ONLY: if (!m || m->m_len != sizeof(int)) { error = EINVAL; break; } optval = *mtod(m, int *); switch (optname) { case IPV6_UNICAST_HOPS: if (optval < -1 || optval >= 256) error = EINVAL; else { /* -1 = kernel default */ in6p->in6p_hops = optval; } break; #define OPTSET(bit) \ do { \ if (optval) \ in6p->in6p_flags |= (bit); \ else \ in6p->in6p_flags &= ~(bit); \ } while (0) case IPV6_RECVOPTS: OPTSET(IN6P_RECVOPTS); break; case IPV6_RECVRETOPTS: OPTSET(IN6P_RECVRETOPTS); break; case IPV6_RECVDSTADDR: OPTSET(IN6P_RECVDSTADDR); break; case IPV6_PKTINFO: OPTSET(IN6P_PKTINFO); break; case IPV6_HOPLIMIT: OPTSET(IN6P_HOPLIMIT); break; case IPV6_HOPOPTS: OPTSET(IN6P_HOPOPTS); break; case IPV6_DSTOPTS: OPTSET(IN6P_DSTOPTS); break; case IPV6_RTHDR: OPTSET(IN6P_RTHDR); break; case IPV6_FAITH: OPTSET(IN6P_FAITH); break; case IPV6_V6ONLY: /* * make setsockopt(IPV6_V6ONLY) * available only prior to bind(2). * see ipng mailing list, Jun 22 2001. */ if (in6p->in6p_lport || !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) { error = EINVAL; break; } #ifdef INET6_BINDV6ONLY if (!optval) error = EINVAL; #else OPTSET(IN6P_IPV6_V6ONLY); #endif break; } break; #undef OPTSET case IPV6_MULTICAST_IF: case IPV6_MULTICAST_HOPS: case IPV6_MULTICAST_LOOP: case IPV6_JOIN_GROUP: case IPV6_LEAVE_GROUP: error = ip6_setmoptions(optname, &in6p->in6p_moptions, m); break; case IPV6_PORTRANGE: optval = *mtod(m, int *); switch (optval) { case IPV6_PORTRANGE_DEFAULT: in6p->in6p_flags &= ~(IN6P_LOWPORT); in6p->in6p_flags &= ~(IN6P_HIGHPORT); break; case IPV6_PORTRANGE_HIGH: in6p->in6p_flags &= ~(IN6P_LOWPORT); in6p->in6p_flags |= IN6P_HIGHPORT; break; case IPV6_PORTRANGE_LOW: in6p->in6p_flags &= ~(IN6P_HIGHPORT); in6p->in6p_flags |= IN6P_LOWPORT; break; default: error = EINVAL; break; } break; #ifdef IPSEC case IPV6_IPSEC_POLICY: { caddr_t req = NULL; size_t len = 0; int priv = 0; if (p == 0 || suser(p->p_ucred, &p->p_acflag)) priv = 0; else priv = 1; if (m) { req = mtod(m, caddr_t); len = m->m_len; } error = ipsec6_set_policy(in6p, optname, req, len, priv); } break; #endif /* IPSEC */ default: error = ENOPROTOOPT; break; } if (m) (void)m_free(m); break; case PRCO_GETOPT: switch (optname) { case IPV6_OPTIONS: case IPV6_RETOPTS: error = ENOPROTOOPT; break; case IPV6_PKTOPTIONS: if (in6p->in6p_options) { *mp = m_copym(in6p->in6p_options, 0, M_COPYALL, M_WAIT); } else { *mp = m_get(M_WAIT, MT_SOOPTS); (*mp)->m_len = 0; } break; case IPV6_HOPOPTS: case IPV6_DSTOPTS: if (p == 0 || suser(p->p_ucred, &p->p_acflag)) { error = EPERM; break; } /* FALLTHROUGH */ case IPV6_UNICAST_HOPS: case IPV6_RECVOPTS: case IPV6_RECVRETOPTS: case IPV6_RECVDSTADDR: case IPV6_PORTRANGE: case IPV6_PKTINFO: case IPV6_HOPLIMIT: case IPV6_RTHDR: case IPV6_FAITH: case IPV6_V6ONLY: *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(int); switch (optname) { case IPV6_UNICAST_HOPS: optval = in6p->in6p_hops; break; #define OPTBIT(bit) (in6p->in6p_flags & bit ? 1 : 0) case IPV6_RECVOPTS: optval = OPTBIT(IN6P_RECVOPTS); break; case IPV6_RECVRETOPTS: optval = OPTBIT(IN6P_RECVRETOPTS); break; case IPV6_RECVDSTADDR: optval = OPTBIT(IN6P_RECVDSTADDR); break; case IPV6_PORTRANGE: { int flags; flags = in6p->in6p_flags; if (flags & IN6P_HIGHPORT) optval = IPV6_PORTRANGE_HIGH; else if (flags & IN6P_LOWPORT) optval = IPV6_PORTRANGE_LOW; else optval = 0; break; } case IPV6_PKTINFO: optval = OPTBIT(IN6P_PKTINFO); break; case IPV6_HOPLIMIT: optval = OPTBIT(IN6P_HOPLIMIT); break; case IPV6_HOPOPTS: optval = OPTBIT(IN6P_HOPOPTS); break; case IPV6_DSTOPTS: optval = OPTBIT(IN6P_DSTOPTS); break; case IPV6_RTHDR: optval = OPTBIT(IN6P_RTHDR); break; case IPV6_FAITH: optval = OPTBIT(IN6P_FAITH); break; case IPV6_V6ONLY: optval = OPTBIT(IN6P_IPV6_V6ONLY); break; } *mtod(m, int *) = optval; break; case IPV6_MULTICAST_IF: case IPV6_MULTICAST_HOPS: case IPV6_MULTICAST_LOOP: case IPV6_JOIN_GROUP: case IPV6_LEAVE_GROUP: error = ip6_getmoptions(optname, in6p->in6p_moptions, mp); break; #ifdef IPSEC case IPV6_IPSEC_POLICY: { caddr_t req = NULL; size_t len = 0; if (m) { req = mtod(m, caddr_t); len = m->m_len; } error = ipsec6_get_policy(in6p, req, len, mp); break; } #endif /* IPSEC */ default: error = ENOPROTOOPT; break; } break; } } else { error = EINVAL; if (op == PRCO_SETOPT && *mp) (void)m_free(*mp); } return (error); } int ip6_raw_ctloutput(op, so, level, optname, mp) int op; struct socket *so; int level, optname; struct mbuf **mp; { int error = 0, optval, optlen; const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum); struct in6pcb *in6p = sotoin6pcb(so); struct mbuf *m = *mp; optlen = m ? m->m_len : 0; if (level != IPPROTO_IPV6) { if (op == PRCO_SETOPT && *mp) (void)m_free(*mp); return (EINVAL); } switch (optname) { case IPV6_CHECKSUM: /* * For ICMPv6 sockets, no modification allowed for checksum * offset, permit "no change" values to help existing apps. * * XXX 2292bis says: "An attempt to set IPV6_CHECKSUM * for an ICMPv6 socket will fail." * The current behavior does not meet 2292bis. */ switch (op) { case PRCO_SETOPT: if (optlen != sizeof(int)) { error = EINVAL; break; } optval = *mtod(m, int *); if ((optval % 2) != 0) { /* the API assumes even offset values */ error = EINVAL; } else if (so->so_proto->pr_protocol == IPPROTO_ICMPV6) { if (optval != icmp6off) error = EINVAL; } else in6p->in6p_cksum = optval; break; case PRCO_GETOPT: if (so->so_proto->pr_protocol == IPPROTO_ICMPV6) optval = icmp6off; else optval = in6p->in6p_cksum; *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(int); *mtod(m, int *) = optval; break; default: error = EINVAL; break; } break; default: error = ENOPROTOOPT; break; } if (op == PRCO_SETOPT && m) (void)m_free(m); return (error); } /* * Set up IP6 options in pcb for insertion in output packets. * Store in mbuf with pointer in pcbopt, adding pseudo-option * with destination address if source routed. */ static int ip6_pcbopts(pktopt, m, so) struct ip6_pktopts **pktopt; struct mbuf *m; struct socket *so; { struct ip6_pktopts *opt = *pktopt; int error = 0; struct proc *p = curproc; /* XXX */ int priv = 0; /* turn off any old options. */ if (opt) { if (opt->ip6po_m) (void)m_free(opt->ip6po_m); } else opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK); *pktopt = 0; if (!m || m->m_len == 0) { /* * Only turning off any previous options. */ if (opt) free(opt, M_IP6OPT); if (m) (void)m_free(m); return (0); } /* set options specified by user. */ if (p && !suser(p->p_ucred, &p->p_acflag)) priv = 1; if ((error = ip6_setpktoptions(m, opt, priv)) != 0) { (void)m_free(m); return (error); } *pktopt = opt; return (0); } /* * Set the IP6 multicast options in response to user setsockopt(). */ static int ip6_setmoptions(optname, im6op, m) int optname; struct ip6_moptions **im6op; struct mbuf *m; { int error = 0; u_int loop, ifindex; struct ipv6_mreq *mreq; struct ifnet *ifp; struct ip6_moptions *im6o = *im6op; struct route_in6 ro; struct sockaddr_in6 *dst; struct in6_multi_mship *imm; struct proc *p = curproc; /* XXX */ if (im6o == NULL) { /* * No multicast option buffer attached to the pcb; * allocate one and initialize to default values. */ im6o = (struct ip6_moptions *) malloc(sizeof(*im6o), M_IPMOPTS, M_WAITOK); if (im6o == NULL) return (ENOBUFS); *im6op = im6o; im6o->im6o_multicast_ifp = NULL; im6o->im6o_multicast_hlim = ip6_defmcasthlim; im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP; LIST_INIT(&im6o->im6o_memberships); } switch (optname) { case IPV6_MULTICAST_IF: /* * Select the interface for outgoing multicast packets. */ if (m == NULL || m->m_len != sizeof(u_int)) { error = EINVAL; break; } bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex)); if (ifindex < 0 || if_index < ifindex) { error = ENXIO; /* XXX EINVAL? */ break; } ifp = ifindex2ifnet[ifindex]; if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { error = EADDRNOTAVAIL; break; } im6o->im6o_multicast_ifp = ifp; break; case IPV6_MULTICAST_HOPS: { /* * Set the IP6 hoplimit for outgoing multicast packets. */ int optval; if (m == NULL || m->m_len != sizeof(int)) { error = EINVAL; break; } bcopy(mtod(m, u_int *), &optval, sizeof(optval)); if (optval < -1 || optval >= 256) error = EINVAL; else if (optval == -1) im6o->im6o_multicast_hlim = ip6_defmcasthlim; else im6o->im6o_multicast_hlim = optval; break; } case IPV6_MULTICAST_LOOP: /* * Set the loopback flag for outgoing multicast packets. * Must be zero or one. */ if (m == NULL || m->m_len != sizeof(u_int)) { error = EINVAL; break; } bcopy(mtod(m, u_int *), &loop, sizeof(loop)); if (loop > 1) { error = EINVAL; break; } im6o->im6o_multicast_loop = loop; break; case IPV6_JOIN_GROUP: /* * Add a multicast group membership. * Group must be a valid IP6 multicast address. */ if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) { error = EINVAL; break; } mreq = mtod(m, struct ipv6_mreq *); if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) { /* * We use the unspecified address to specify to accept * all multicast addresses. Only super user is allowed * to do this. */ if (suser(p->p_ucred, &p->p_acflag)) { error = EACCES; break; } } else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) { error = EINVAL; break; } /* * If the interface is specified, validate it. */ if (mreq->ipv6mr_interface < 0 || if_index < mreq->ipv6mr_interface) { error = ENXIO; /* XXX EINVAL? */ break; } /* * If no interface was explicitly specified, choose an * appropriate one according to the given multicast address. */ if (mreq->ipv6mr_interface == 0) { /* * If the multicast address is in node-local scope, * the interface should be a loopback interface. * Otherwise, look up the routing table for the * address, and choose the outgoing interface. * XXX: is it a good approach? */ if (IN6_IS_ADDR_MC_NODELOCAL(&mreq->ipv6mr_multiaddr)) { ifp = &loif[0]; } else { ro.ro_rt = NULL; dst = (struct sockaddr_in6 *)&ro.ro_dst; bzero(dst, sizeof(*dst)); dst->sin6_len = sizeof(struct sockaddr_in6); dst->sin6_family = AF_INET6; dst->sin6_addr = mreq->ipv6mr_multiaddr; rtalloc((struct route *)&ro); if (ro.ro_rt == NULL) { error = EADDRNOTAVAIL; break; } ifp = ro.ro_rt->rt_ifp; rtfree(ro.ro_rt); } } else ifp = ifindex2ifnet[mreq->ipv6mr_interface]; /* * See if we found an interface, and confirm that it * supports multicast */ if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) { error = EADDRNOTAVAIL; break; } /* * Put interface index into the multicast address, * if the address has link-local scope. */ if (IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) { mreq->ipv6mr_multiaddr.s6_addr16[1] = htons(mreq->ipv6mr_interface); } /* * See if the membership already exists. */ for (imm = im6o->im6o_memberships.lh_first; imm != NULL; imm = imm->i6mm_chain.le_next) if (imm->i6mm_maddr->in6m_ifp == ifp && IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr, &mreq->ipv6mr_multiaddr)) break; if (imm != NULL) { error = EADDRINUSE; break; } /* * Everything looks good; add a new record to the multicast * address list for the given interface. */ imm = in6_joingroup(ifp, &mreq->ipv6mr_multiaddr, &error); if (!imm) break; LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain); break; case IPV6_LEAVE_GROUP: /* * Drop a multicast group membership. * Group must be a valid IP6 multicast address. */ if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) { error = EINVAL; break; } mreq = mtod(m, struct ipv6_mreq *); if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) { if (suser(p->p_ucred, &p->p_acflag)) { error = EACCES; break; } } else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) { error = EINVAL; break; } /* * If an interface address was specified, get a pointer * to its ifnet structure. */ if (mreq->ipv6mr_interface < 0 || if_index < mreq->ipv6mr_interface) { error = ENXIO; /* XXX EINVAL? */ break; } ifp = ifindex2ifnet[mreq->ipv6mr_interface]; /* * Put interface index into the multicast address, * if the address has link-local scope. */ if (IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) { mreq->ipv6mr_multiaddr.s6_addr16[1] = htons(mreq->ipv6mr_interface); } /* * Find the membership in the membership list. */ for (imm = im6o->im6o_memberships.lh_first; imm != NULL; imm = imm->i6mm_chain.le_next) { if ((ifp == NULL || imm->i6mm_maddr->in6m_ifp == ifp) && IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr, &mreq->ipv6mr_multiaddr)) break; } if (imm == NULL) { /* Unable to resolve interface */ error = EADDRNOTAVAIL; break; } /* * Give up the multicast address record to which the * membership points. */ LIST_REMOVE(imm, i6mm_chain); in6_leavegroup(imm); break; default: error = EOPNOTSUPP; break; } /* * If all options have default values, no need to keep the mbuf. */ if (im6o->im6o_multicast_ifp == NULL && im6o->im6o_multicast_hlim == ip6_defmcasthlim && im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP && im6o->im6o_memberships.lh_first == NULL) { free(*im6op, M_IPMOPTS); *im6op = NULL; } return (error); } /* * Return the IP6 multicast options in response to user getsockopt(). */ static int ip6_getmoptions(optname, im6o, mp) int optname; struct ip6_moptions *im6o; struct mbuf **mp; { u_int *hlim, *loop, *ifindex; *mp = m_get(M_WAIT, MT_SOOPTS); switch (optname) { case IPV6_MULTICAST_IF: ifindex = mtod(*mp, u_int *); (*mp)->m_len = sizeof(u_int); if (im6o == NULL || im6o->im6o_multicast_ifp == NULL) *ifindex = 0; else *ifindex = im6o->im6o_multicast_ifp->if_index; return (0); case IPV6_MULTICAST_HOPS: hlim = mtod(*mp, u_int *); (*mp)->m_len = sizeof(u_int); if (im6o == NULL) *hlim = ip6_defmcasthlim; else *hlim = im6o->im6o_multicast_hlim; return (0); case IPV6_MULTICAST_LOOP: loop = mtod(*mp, u_int *); (*mp)->m_len = sizeof(u_int); if (im6o == NULL) *loop = ip6_defmcasthlim; else *loop = im6o->im6o_multicast_loop; return (0); default: return (EOPNOTSUPP); } } /* * Discard the IP6 multicast options. */ void ip6_freemoptions(im6o) struct ip6_moptions *im6o; { struct in6_multi_mship *imm; if (im6o == NULL) return; while ((imm = im6o->im6o_memberships.lh_first) != NULL) { LIST_REMOVE(imm, i6mm_chain); in6_leavegroup(imm); } free(im6o, M_IPMOPTS); } /* * Set IPv6 outgoing packet options based on advanced API. */ int ip6_setpktoptions(control, opt, priv) struct mbuf *control; struct ip6_pktopts *opt; int priv; { struct cmsghdr *cm = 0; if (control == 0 || opt == 0) return (EINVAL); bzero(opt, sizeof(*opt)); opt->ip6po_hlim = -1; /* -1 means to use default hop limit */ /* * XXX: Currently, we assume all the optional information is stored * in a single mbuf. */ if (control->m_next) return (EINVAL); opt->ip6po_m = control; for (; control->m_len; control->m_data += CMSG_ALIGN(cm->cmsg_len), control->m_len -= CMSG_ALIGN(cm->cmsg_len)) { cm = mtod(control, struct cmsghdr *); if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len) return (EINVAL); if (cm->cmsg_level != IPPROTO_IPV6) continue; switch (cm->cmsg_type) { case IPV6_PKTINFO: if (cm->cmsg_len != CMSG_LEN(sizeof(struct in6_pktinfo))) return (EINVAL); opt->ip6po_pktinfo = (struct in6_pktinfo *)CMSG_DATA(cm); if (opt->ip6po_pktinfo->ipi6_ifindex && IN6_IS_ADDR_LINKLOCAL(&opt->ip6po_pktinfo->ipi6_addr)) opt->ip6po_pktinfo->ipi6_addr.s6_addr16[1] = htons(opt->ip6po_pktinfo->ipi6_ifindex); if (opt->ip6po_pktinfo->ipi6_ifindex > if_index || opt->ip6po_pktinfo->ipi6_ifindex < 0) { return (ENXIO); } /* * Check if the requested source address is indeed a * unicast address assigned to the node, and can be * used as the packet's source address. */ if (!IN6_IS_ADDR_UNSPECIFIED(&opt->ip6po_pktinfo->ipi6_addr)) { struct ifaddr *ia; struct in6_ifaddr *ia6; struct sockaddr_in6 sin6; bzero(&sin6, sizeof(sin6)); sin6.sin6_len = sizeof(sin6); sin6.sin6_family = AF_INET6; sin6.sin6_addr = opt->ip6po_pktinfo->ipi6_addr; ia = ifa_ifwithaddr(sin6tosa(&sin6)); if (ia == NULL || (opt->ip6po_pktinfo->ipi6_ifindex && (ia->ifa_ifp->if_index != opt->ip6po_pktinfo->ipi6_ifindex))) { return (EADDRNOTAVAIL); } ia6 = (struct in6_ifaddr *)ia; if ((ia6->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) != 0) { return (EADDRNOTAVAIL); } /* * Check if the requested source address is * indeed a unicast address assigned to the * node. */ if (IN6_IS_ADDR_MULTICAST(&opt->ip6po_pktinfo->ipi6_addr)) return (EADDRNOTAVAIL); } break; case IPV6_HOPLIMIT: if (cm->cmsg_len != CMSG_LEN(sizeof(int))) return (EINVAL); bcopy(CMSG_DATA(cm), &opt->ip6po_hlim, sizeof(opt->ip6po_hlim)); if (opt->ip6po_hlim < -1 || opt->ip6po_hlim > 255) return (EINVAL); break; case IPV6_NEXTHOP: if (!priv) return (EPERM); /* check if cmsg_len is large enough for sa_len */ if (cm->cmsg_len < sizeof(u_char) || cm->cmsg_len < CMSG_LEN(*CMSG_DATA(cm))) return (EINVAL); opt->ip6po_nexthop = (struct sockaddr *)CMSG_DATA(cm); break; case IPV6_HOPOPTS: if (cm->cmsg_len < CMSG_LEN(sizeof(struct ip6_hbh))) return (EINVAL); opt->ip6po_hbh = (struct ip6_hbh *)CMSG_DATA(cm); if (cm->cmsg_len != CMSG_LEN((opt->ip6po_hbh->ip6h_len + 1) << 3)) return (EINVAL); break; case IPV6_DSTOPTS: if (cm->cmsg_len < CMSG_LEN(sizeof(struct ip6_dest))) return (EINVAL); /* * If there is no routing header yet, the destination * options header should be put on the 1st part. * Otherwise, the header should be on the 2nd part. * (See RFC 2460, section 4.1) */ if (opt->ip6po_rthdr == NULL) { opt->ip6po_dest1 = (struct ip6_dest *)CMSG_DATA(cm); if (cm->cmsg_len != CMSG_LEN((opt->ip6po_dest1->ip6d_len + 1) << 3)); return (EINVAL); } else { opt->ip6po_dest2 = (struct ip6_dest *)CMSG_DATA(cm); if (cm->cmsg_len != CMSG_LEN((opt->ip6po_dest2->ip6d_len + 1) << 3)) return (EINVAL); } break; case IPV6_RTHDR: if (cm->cmsg_len < CMSG_LEN(sizeof(struct ip6_rthdr))) return (EINVAL); opt->ip6po_rthdr = (struct ip6_rthdr *)CMSG_DATA(cm); if (cm->cmsg_len != CMSG_LEN((opt->ip6po_rthdr->ip6r_len + 1) << 3)) return (EINVAL); switch (opt->ip6po_rthdr->ip6r_type) { case IPV6_RTHDR_TYPE_0: if (opt->ip6po_rthdr->ip6r_segleft == 0) return (EINVAL); break; default: return (EINVAL); } break; default: return (ENOPROTOOPT); } } return (0); } /* * Routine called from ip6_output() to loop back a copy of an IP6 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 ip6_mloopback(ifp, m, dst) struct ifnet *ifp; struct mbuf *m; struct sockaddr_in6 *dst; { struct mbuf *copym; struct ip6_hdr *ip6; copym = m_copy(m, 0, M_COPYALL); if (copym == NULL) return; /* * Make sure to deep-copy IPv6 header portion in case the data * is in an mbuf cluster, so that we can safely override the IPv6 * header portion later. */ if ((copym->m_flags & M_EXT) != 0 || copym->m_len < sizeof(struct ip6_hdr)) { copym = m_pullup(copym, sizeof(struct ip6_hdr)); if (copym == NULL) return; } #ifdef DIAGNOSTIC if (copym->m_len < sizeof(*ip6)) { m_freem(copym); return; } #endif ip6 = mtod(copym, struct ip6_hdr *); if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) ip6->ip6_src.s6_addr16[1] = 0; if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) ip6->ip6_dst.s6_addr16[1] = 0; (void)looutput(ifp, copym, (struct sockaddr *)dst, NULL); } /* * Chop IPv6 header off from the payload. */ static int ip6_splithdr(m, exthdrs) struct mbuf *m; struct ip6_exthdrs *exthdrs; { struct mbuf *mh; struct ip6_hdr *ip6; ip6 = mtod(m, struct ip6_hdr *); if (m->m_len > sizeof(*ip6)) { MGETHDR(mh, M_DONTWAIT, MT_HEADER); if (mh == 0) { m_freem(m); return ENOBUFS; } M_COPY_PKTHDR(mh, m); MH_ALIGN(mh, sizeof(*ip6)); m->m_flags &= ~M_PKTHDR; m->m_len -= sizeof(*ip6); m->m_data += sizeof(*ip6); mh->m_next = m; m = mh; m->m_len = sizeof(*ip6); bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6)); } exthdrs->ip6e_ip6 = m; return 0; } /* * Compute IPv6 extension header length. */ int ip6_optlen(in6p) struct in6pcb *in6p; { int len; if (!in6p->in6p_outputopts) return 0; len = 0; #define elen(x) \ (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0) len += elen(in6p->in6p_outputopts->ip6po_hbh); len += elen(in6p->in6p_outputopts->ip6po_dest1); len += elen(in6p->in6p_outputopts->ip6po_rthdr); len += elen(in6p->in6p_outputopts->ip6po_dest2); return len; #undef elen }