From a9153ec3040f54fa52b68e14dafed2aba7b780ae Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Wed, 7 Mar 2012 09:52:04 -0600 Subject: Initial import Code is based on FreeBSD 8.2 with USB support from Sebastian Huber and Thomas Doerfler. Initial TCP/IP stack work is from Kevel Kirspel. --- rtems/freebsd/netinet6/ip6_forward.c | 626 +++++++++++++++++++++++++++++++++++ 1 file changed, 626 insertions(+) create mode 100644 rtems/freebsd/netinet6/ip6_forward.c (limited to 'rtems/freebsd/netinet6/ip6_forward.c') diff --git a/rtems/freebsd/netinet6/ip6_forward.c b/rtems/freebsd/netinet6/ip6_forward.c new file mode 100644 index 00000000..af342c07 --- /dev/null +++ b/rtems/freebsd/netinet6/ip6_forward.c @@ -0,0 +1,626 @@ +#include + +/*- + * 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. + * + * $KAME: ip6_forward.c,v 1.69 2001/05/17 03:48:30 itojun Exp $ + */ + +#include +__FBSDID("$FreeBSD$"); + +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#ifdef IPSEC +#include +#include +#include +#endif /* IPSEC */ + +#include + +/* + * Forward a packet. If some error occurs return the sender + * an icmp packet. Note we can't always generate a meaningful + * icmp message because icmp doesn't have a large enough repertoire + * of codes and types. + * + * If not forwarding, just drop the packet. This could be confusing + * if ipforwarding was zero but some routing protocol was advancing + * us as a gateway to somewhere. However, we must let the routing + * protocol deal with that. + * + */ +void +ip6_forward(struct mbuf *m, int srcrt) +{ + struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); + struct sockaddr_in6 *dst = NULL; + struct rtentry *rt = NULL; + struct route_in6 rin6; + int error, type = 0, code = 0; + struct mbuf *mcopy = NULL; + struct ifnet *origifp; /* maybe unnecessary */ + u_int32_t inzone, outzone; + struct in6_addr src_in6, dst_in6; +#ifdef IPSEC + struct secpolicy *sp = NULL; + int ipsecrt = 0; +#endif + char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN]; + +#ifdef IPSEC + /* + * Check AH/ESP integrity. + */ + /* + * Don't increment ip6s_cantforward because this is the check + * before forwarding packet actually. + */ + if (ipsec6_in_reject(m, NULL)) { + V_ipsec6stat.in_polvio++; + m_freem(m); + return; + } +#endif /* IPSEC */ + + /* + * Do not forward packets to multicast destination (should be handled + * by ip6_mforward(). + * Do not forward packets with unspecified source. It was discussed + * in July 2000, on the ipngwg mailing list. + */ + if ((m->m_flags & (M_BCAST|M_MCAST)) != 0 || + IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || + IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) { + V_ip6stat.ip6s_cantforward++; + /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ + if (V_ip6_log_time + V_ip6_log_interval < time_second) { + V_ip6_log_time = time_second; + log(LOG_DEBUG, + "cannot forward " + "from %s to %s nxt %d received on %s\n", + ip6_sprintf(ip6bufs, &ip6->ip6_src), + ip6_sprintf(ip6bufd, &ip6->ip6_dst), + ip6->ip6_nxt, + if_name(m->m_pkthdr.rcvif)); + } + m_freem(m); + return; + } + +#ifdef IPSTEALTH + if (!V_ip6stealth) { +#endif + if (ip6->ip6_hlim <= IPV6_HLIMDEC) { + /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ + icmp6_error(m, ICMP6_TIME_EXCEEDED, + ICMP6_TIME_EXCEED_TRANSIT, 0); + return; + } + ip6->ip6_hlim -= IPV6_HLIMDEC; + +#ifdef IPSTEALTH + } +#endif + + /* + * Save at most ICMPV6_PLD_MAXLEN (= the min IPv6 MTU - + * size of IPv6 + ICMPv6 headers) bytes of the packet in case + * we need to generate an ICMP6 message to the src. + * Thanks to M_EXT, in most cases copy will not occur. + * + * It is important to save it before IPsec processing as IPsec + * processing may modify the mbuf. + */ + mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); + +#ifdef IPSEC + /* get a security policy for this packet */ + sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, + IP_FORWARDING, &error); + if (sp == NULL) { + V_ipsec6stat.out_inval++; + V_ip6stat.ip6s_cantforward++; + if (mcopy) { +#if 0 + /* XXX: what icmp ? */ +#else + m_freem(mcopy); +#endif + } + m_freem(m); + return; + } + + error = 0; + + /* check policy */ + switch (sp->policy) { + case IPSEC_POLICY_DISCARD: + /* + * This packet is just discarded. + */ + V_ipsec6stat.out_polvio++; + V_ip6stat.ip6s_cantforward++; + KEY_FREESP(&sp); + if (mcopy) { +#if 0 + /* XXX: what icmp ? */ +#else + m_freem(mcopy); +#endif + } + m_freem(m); + return; + + case IPSEC_POLICY_BYPASS: + case IPSEC_POLICY_NONE: + /* no need to do IPsec. */ + KEY_FREESP(&sp); + goto skip_ipsec; + + case IPSEC_POLICY_IPSEC: + if (sp->req == NULL) { + /* XXX should be panic ? */ + printf("ip6_forward: No IPsec request specified.\n"); + V_ip6stat.ip6s_cantforward++; + KEY_FREESP(&sp); + if (mcopy) { +#if 0 + /* XXX: what icmp ? */ +#else + m_freem(mcopy); +#endif + } + m_freem(m); + return; + } + /* do IPsec */ + break; + + case IPSEC_POLICY_ENTRUST: + default: + /* should be panic ?? */ + printf("ip6_forward: Invalid policy found. %d\n", sp->policy); + KEY_FREESP(&sp); + goto skip_ipsec; + } + + { + struct ipsecrequest *isr = NULL; + struct ipsec_output_state state; + + /* + * when the kernel forwards a packet, it is not proper to apply + * IPsec transport mode to the packet is not proper. this check + * avoid from this. + * at present, if there is even a transport mode SA request in the + * security policy, the kernel does not apply IPsec to the packet. + * this check is not enough because the following case is valid. + * ipsec esp/tunnel/xxx-xxx/require esp/transport//require; + */ + for (isr = sp->req; isr; isr = isr->next) { + if (isr->saidx.mode == IPSEC_MODE_ANY) + goto doipsectunnel; + if (isr->saidx.mode == IPSEC_MODE_TUNNEL) + goto doipsectunnel; + } + + /* + * if there's no need for tunnel mode IPsec, skip. + */ + if (!isr) + goto skip_ipsec; + + doipsectunnel: + /* + * 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(&state, sizeof(state)); + state.m = m; + state.ro = NULL; /* update at ipsec6_output_tunnel() */ + state.dst = NULL; /* update at ipsec6_output_tunnel() */ + + error = ipsec6_output_tunnel(&state, sp, 0); + + m = state.m; + KEY_FREESP(&sp); + + if (error) { + /* mbuf is already reclaimed in ipsec6_output_tunnel. */ + 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 */ + break; + } + V_ip6stat.ip6s_cantforward++; + if (mcopy) { +#if 0 + /* XXX: what icmp ? */ +#else + m_freem(mcopy); +#endif + } + m_freem(m); + return; + } else { + /* + * In the FAST IPSec case we have already + * re-injected the packet and it has been freed + * by the ipsec_done() function. So, just clean + * up after ourselves. + */ + m = NULL; + goto freecopy; + } + + if ((m != NULL) && (ip6 != mtod(m, struct ip6_hdr *)) ){ + /* + * now tunnel mode headers are added. we are originating + * packet instead of forwarding the packet. + */ + ip6_output(m, NULL, NULL, IPV6_FORWARDING/*XXX*/, NULL, NULL, + NULL); + goto freecopy; + } + + /* adjust pointer */ + dst = (struct sockaddr_in6 *)state.dst; + rt = state.ro ? state.ro->ro_rt : NULL; + if (dst != NULL && rt != NULL) + ipsecrt = 1; + } + if (ipsecrt) + goto skip_routing; +skip_ipsec: +#endif + + bzero(&rin6, sizeof(struct route_in6)); + dst = (struct sockaddr_in6 *)&rin6.ro_dst; + dst->sin6_len = sizeof(struct sockaddr_in6); + dst->sin6_family = AF_INET6; + dst->sin6_addr = ip6->ip6_dst; + + rin6.ro_rt = rtalloc1((struct sockaddr *)dst, 0, 0); + if (rin6.ro_rt != NULL) + RT_UNLOCK(rin6.ro_rt); + else { + V_ip6stat.ip6s_noroute++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_noroute); + if (mcopy) { + icmp6_error(mcopy, ICMP6_DST_UNREACH, + ICMP6_DST_UNREACH_NOROUTE, 0); + } + goto bad; + } + rt = rin6.ro_rt; +#ifdef IPSEC +skip_routing: +#endif + + /* + * Source scope check: if a packet can't be delivered to its + * destination for the reason that the destination is beyond the scope + * of the source address, discard the packet and return an icmp6 + * destination unreachable error with Code 2 (beyond scope of source + * address). We use a local copy of ip6_src, since in6_setscope() + * will possibly modify its first argument. + * [draft-ietf-ipngwg-icmp-v3-04.txt, Section 3.1] + */ + src_in6 = ip6->ip6_src; + if (in6_setscope(&src_in6, rt->rt_ifp, &outzone)) { + /* XXX: this should not happen */ + V_ip6stat.ip6s_cantforward++; + V_ip6stat.ip6s_badscope++; + goto bad; + } + if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { + V_ip6stat.ip6s_cantforward++; + V_ip6stat.ip6s_badscope++; + goto bad; + } + if (inzone != outzone +#ifdef IPSEC + && !ipsecrt +#endif + ) { + V_ip6stat.ip6s_cantforward++; + V_ip6stat.ip6s_badscope++; + in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); + + if (V_ip6_log_time + V_ip6_log_interval < time_second) { + V_ip6_log_time = time_second; + log(LOG_DEBUG, + "cannot forward " + "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", + ip6_sprintf(ip6bufs, &ip6->ip6_src), + ip6_sprintf(ip6bufd, &ip6->ip6_dst), + ip6->ip6_nxt, + if_name(m->m_pkthdr.rcvif), if_name(rt->rt_ifp)); + } + if (mcopy) + icmp6_error(mcopy, ICMP6_DST_UNREACH, + ICMP6_DST_UNREACH_BEYONDSCOPE, 0); + goto bad; + } + + /* + * Destination scope check: if a packet is going to break the scope + * zone of packet's destination address, discard it. This case should + * usually be prevented by appropriately-configured routing table, but + * we need an explicit check because we may mistakenly forward the + * packet to a different zone by (e.g.) a default route. + */ + dst_in6 = ip6->ip6_dst; + if (in6_setscope(&dst_in6, m->m_pkthdr.rcvif, &inzone) != 0 || + in6_setscope(&dst_in6, rt->rt_ifp, &outzone) != 0 || + inzone != outzone) { + V_ip6stat.ip6s_cantforward++; + V_ip6stat.ip6s_badscope++; + goto bad; + } + + if (m->m_pkthdr.len > IN6_LINKMTU(rt->rt_ifp)) { + in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); + if (mcopy) { + u_long mtu; +#ifdef IPSEC + struct secpolicy *sp; + int ipsecerror; + size_t ipsechdrsiz; +#endif /* IPSEC */ + + mtu = IN6_LINKMTU(rt->rt_ifp); +#ifdef IPSEC + /* + * When we do IPsec tunnel ingress, we need to play + * with the link value (decrement IPsec header size + * from mtu value). The code is much simpler than v4 + * case, as we have the outgoing interface for + * encapsulated packet as "rt->rt_ifp". + */ + sp = ipsec_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, + IP_FORWARDING, &ipsecerror); + if (sp) { + ipsechdrsiz = ipsec_hdrsiz(mcopy, + IPSEC_DIR_OUTBOUND, NULL); + if (ipsechdrsiz < mtu) + mtu -= ipsechdrsiz; + } + + /* + * if mtu becomes less than minimum MTU, + * tell minimum MTU (and I'll need to fragment it). + */ + if (mtu < IPV6_MMTU) + mtu = IPV6_MMTU; +#endif /* IPSEC */ + icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); + } + goto bad; + } + + if (rt->rt_flags & RTF_GATEWAY) + dst = (struct sockaddr_in6 *)rt->rt_gateway; + + /* + * If we are to forward the packet using the same interface + * as one we got the packet from, perhaps we should send a redirect + * to sender to shortcut a hop. + * Only send redirect if source is sending directly to us, + * and if packet was not source routed (or has any options). + * Also, don't send redirect if forwarding using a route + * modified by a redirect. + */ + if (V_ip6_sendredirects && rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && +#ifdef IPSEC + !ipsecrt && +#endif /* IPSEC */ + (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) { + if ((rt->rt_ifp->if_flags & IFF_POINTOPOINT) != 0) { + /* + * If the incoming interface is equal to the outgoing + * one, and the link attached to the interface is + * point-to-point, then it will be highly probable + * that a routing loop occurs. Thus, we immediately + * drop the packet and send an ICMPv6 error message. + * + * type/code is based on suggestion by Rich Draves. + * not sure if it is the best pick. + */ + icmp6_error(mcopy, ICMP6_DST_UNREACH, + ICMP6_DST_UNREACH_ADDR, 0); + goto bad; + } + type = ND_REDIRECT; + } + + /* + * Fake scoped addresses. Note that even link-local source or + * destinaion can appear, if the originating node just sends the + * packet to us (without address resolution for the destination). + * Since both icmp6_error and icmp6_redirect_output fill the embedded + * link identifiers, we can do this stuff after making a copy for + * returning an error. + */ + if ((rt->rt_ifp->if_flags & IFF_LOOPBACK) != 0) { + /* + * See corresponding comments in ip6_output. + * XXX: but is it possible that ip6_forward() sends a packet + * to a loopback interface? I don't think so, and thus + * I bark here. (jinmei@kame.net) + * XXX: it is common to route invalid packets to loopback. + * also, the codepath will be visited on use of ::1 in + * rthdr. (itojun) + */ +#if 1 + if (0) +#else + if ((rt->rt_flags & (RTF_BLACKHOLE|RTF_REJECT)) == 0) +#endif + { + printf("ip6_forward: outgoing interface is loopback. " + "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", + ip6_sprintf(ip6bufs, &ip6->ip6_src), + ip6_sprintf(ip6bufd, &ip6->ip6_dst), + ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif), + if_name(rt->rt_ifp)); + } + + /* we can just use rcvif in forwarding. */ + origifp = m->m_pkthdr.rcvif; + } + else + origifp = rt->rt_ifp; + /* + * clear embedded scope identifiers if necessary. + * in6_clearscope will touch the addresses only when necessary. + */ + in6_clearscope(&ip6->ip6_src); + in6_clearscope(&ip6->ip6_dst); + + /* Jump over all PFIL processing if hooks are not active. */ + if (!PFIL_HOOKED(&V_inet6_pfil_hook)) + goto pass; + + /* Run through list of hooks for output packets. */ + error = pfil_run_hooks(&V_inet6_pfil_hook, &m, rt->rt_ifp, PFIL_OUT, NULL); + if (error != 0) + goto senderr; + if (m == NULL) + goto freecopy; + ip6 = mtod(m, struct ip6_hdr *); + +pass: + error = nd6_output(rt->rt_ifp, origifp, m, dst, rt); + if (error) { + in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); + V_ip6stat.ip6s_cantforward++; + } else { + V_ip6stat.ip6s_forward++; + in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); + if (type) + V_ip6stat.ip6s_redirectsent++; + else { + if (mcopy) + goto freecopy; + } + } + +senderr: + if (mcopy == NULL) + goto out; + switch (error) { + case 0: + if (type == ND_REDIRECT) { + icmp6_redirect_output(mcopy, rt); + goto out; + } + goto freecopy; + + case EMSGSIZE: + /* xxx MTU is constant in PPP? */ + goto freecopy; + + case ENOBUFS: + /* Tell source to slow down like source quench in IP? */ + goto freecopy; + + case ENETUNREACH: /* shouldn't happen, checked above */ + case EHOSTUNREACH: + case ENETDOWN: + case EHOSTDOWN: + default: + type = ICMP6_DST_UNREACH; + code = ICMP6_DST_UNREACH_ADDR; + break; + } + icmp6_error(mcopy, type, code, 0); + goto out; + + freecopy: + m_freem(mcopy); + goto out; +bad: + m_freem(m); +out: + if (rt != NULL +#ifdef IPSEC + && !ipsecrt +#endif + ) + RTFREE(rt); +} -- cgit v1.2.3