Index: head/sys/netinet6/frag6.c =================================================================== --- head/sys/netinet6/frag6.c (revision 158294) +++ head/sys/netinet6/frag6.c (revision 158295) @@ -1,748 +1,752 @@ /* $FreeBSD$ */ /* $KAME: frag6.c,v 1.33 2002/01/07 11:34:48 kjc 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* for ECN definitions */ #include /* for ECN definitions */ #include /* * Define it to get a correct behavior on per-interface statistics. * You will need to perform an extra routing table lookup, per fragment, * to do it. This may, or may not be, a performance hit. */ #define IN6_IFSTAT_STRICT static void frag6_enq __P((struct ip6asfrag *, struct ip6asfrag *)); static void frag6_deq __P((struct ip6asfrag *)); static void frag6_insque __P((struct ip6q *, struct ip6q *)); static void frag6_remque __P((struct ip6q *)); static void frag6_freef __P((struct ip6q *)); static struct mtx ip6qlock; /* * These fields all protected by ip6qlock. */ static u_int frag6_nfragpackets; static u_int frag6_nfrags; static struct ip6q ip6q; /* ip6 reassemble queue */ #define IP6Q_LOCK_INIT() mtx_init(&ip6qlock, "ip6qlock", NULL, MTX_DEF); #define IP6Q_LOCK() mtx_lock(&ip6qlock) #define IP6Q_TRYLOCK() mtx_trylock(&ip6qlock) #define IP6Q_LOCK_ASSERT() mtx_assert(&ip6qlock, MA_OWNED) #define IP6Q_UNLOCK() mtx_unlock(&ip6qlock) static MALLOC_DEFINE(M_FTABLE, "fragment", "fragment reassembly header"); /* * Initialise reassembly queue and fragment identifier. */ static void frag6_change(void *tag) { ip6_maxfragpackets = nmbclusters / 4; ip6_maxfrags = nmbclusters / 4; } void frag6_init() { ip6_maxfragpackets = nmbclusters / 4; ip6_maxfrags = nmbclusters / 4; EVENTHANDLER_REGISTER(nmbclusters_change, frag6_change, NULL, EVENTHANDLER_PRI_ANY); IP6Q_LOCK_INIT(); ip6q.ip6q_next = ip6q.ip6q_prev = &ip6q; } /* * In RFC2460, fragment and reassembly rule do not agree with each other, * in terms of next header field handling in fragment header. * While the sender will use the same value for all of the fragmented packets, * receiver is suggested not to check the consistency. * * fragment rule (p20): * (2) A Fragment header containing: * The Next Header value that identifies the first header of * the Fragmentable Part of the original packet. * -> next header field is same for all fragments * * reassembly rule (p21): * The Next Header field of the last header of the Unfragmentable * Part is obtained from the Next Header field of the first * fragment's Fragment header. * -> should grab it from the first fragment only * * The following note also contradicts with fragment rule - noone is going to * send different fragment with different next header field. * * additional note (p22): * The Next Header values in the Fragment headers of different * fragments of the same original packet may differ. Only the value * from the Offset zero fragment packet is used for reassembly. * -> should grab it from the first fragment only * * There is no explicit reason given in the RFC. Historical reason maybe? */ /* * Fragment input */ int frag6_input(mp, offp, proto) struct mbuf **mp; int *offp, proto; { struct mbuf *m = *mp, *t; struct ip6_hdr *ip6; struct ip6_frag *ip6f; struct ip6q *q6; struct ip6asfrag *af6, *ip6af, *af6dwn; #ifdef IN6_IFSTAT_STRICT struct in6_ifaddr *ia; #endif int offset = *offp, nxt, i, next; int first_frag = 0; int fragoff, frgpartlen; /* must be larger than u_int16_t */ struct ifnet *dstifp; u_int8_t ecn, ecn0; ip6 = mtod(m, struct ip6_hdr *); #ifndef PULLDOWN_TEST IP6_EXTHDR_CHECK(m, offset, sizeof(struct ip6_frag), IPPROTO_DONE); ip6f = (struct ip6_frag *)((caddr_t)ip6 + offset); #else IP6_EXTHDR_GET(ip6f, struct ip6_frag *, m, offset, sizeof(*ip6f)); if (ip6f == NULL) return (IPPROTO_DONE); #endif dstifp = NULL; #ifdef IN6_IFSTAT_STRICT /* find the destination interface of the packet. */ if ((ia = ip6_getdstifaddr(m)) != NULL) dstifp = ia->ia_ifp; #else /* we are violating the spec, this is not the destination interface */ if ((m->m_flags & M_PKTHDR) != 0) dstifp = m->m_pkthdr.rcvif; #endif /* jumbo payload can't contain a fragment header */ if (ip6->ip6_plen == 0) { icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, offset); in6_ifstat_inc(dstifp, ifs6_reass_fail); return IPPROTO_DONE; } /* * check whether fragment packet's fragment length is * multiple of 8 octets. * sizeof(struct ip6_frag) == 8 * sizeof(struct ip6_hdr) = 40 */ if ((ip6f->ip6f_offlg & IP6F_MORE_FRAG) && (((ntohs(ip6->ip6_plen) - offset) & 0x7) != 0)) { icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, offsetof(struct ip6_hdr, ip6_plen)); in6_ifstat_inc(dstifp, ifs6_reass_fail); return IPPROTO_DONE; } ip6stat.ip6s_fragments++; in6_ifstat_inc(dstifp, ifs6_reass_reqd); /* offset now points to data portion */ offset += sizeof(struct ip6_frag); IP6Q_LOCK(); /* * Enforce upper bound on number of fragments. * If maxfrag is 0, never accept fragments. * If maxfrag is -1, accept all fragments without limitation. */ if (ip6_maxfrags < 0) ; else if (frag6_nfrags >= (u_int)ip6_maxfrags) goto dropfrag; for (q6 = ip6q.ip6q_next; q6 != &ip6q; q6 = q6->ip6q_next) if (ip6f->ip6f_ident == q6->ip6q_ident && IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &q6->ip6q_src) && IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &q6->ip6q_dst)) break; if (q6 == &ip6q) { /* * the first fragment to arrive, create a reassembly queue. */ first_frag = 1; /* * Enforce upper bound on number of fragmented packets * for which we attempt reassembly; * If maxfragpackets is 0, never accept fragments. * If maxfragpackets is -1, accept all fragments without * limitation. */ if (ip6_maxfragpackets < 0) ; else if (frag6_nfragpackets >= (u_int)ip6_maxfragpackets) goto dropfrag; frag6_nfragpackets++; q6 = (struct ip6q *)malloc(sizeof(struct ip6q), M_FTABLE, M_NOWAIT); if (q6 == NULL) goto dropfrag; bzero(q6, sizeof(*q6)); frag6_insque(q6, &ip6q); /* ip6q_nxt will be filled afterwards, from 1st fragment */ q6->ip6q_down = q6->ip6q_up = (struct ip6asfrag *)q6; #ifdef notyet q6->ip6q_nxtp = (u_char *)nxtp; #endif q6->ip6q_ident = ip6f->ip6f_ident; q6->ip6q_arrive = 0; /* Is it used anywhere? */ q6->ip6q_ttl = IPV6_FRAGTTL; q6->ip6q_src = ip6->ip6_src; q6->ip6q_dst = ip6->ip6_dst; q6->ip6q_unfrglen = -1; /* The 1st fragment has not arrived. */ q6->ip6q_nfrag = 0; } /* * If it's the 1st fragment, record the length of the * unfragmentable part and the next header of the fragment header. */ fragoff = ntohs(ip6f->ip6f_offlg & IP6F_OFF_MASK); if (fragoff == 0) { q6->ip6q_unfrglen = offset - sizeof(struct ip6_hdr) - sizeof(struct ip6_frag); q6->ip6q_nxt = ip6f->ip6f_nxt; } /* * Check that the reassembled packet would not exceed 65535 bytes * in size. * If it would exceed, discard the fragment and return an ICMP error. */ frgpartlen = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen) - offset; if (q6->ip6q_unfrglen >= 0) { /* The 1st fragment has already arrived. */ if (q6->ip6q_unfrglen + fragoff + frgpartlen > IPV6_MAXPACKET) { icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, offset - sizeof(struct ip6_frag) + offsetof(struct ip6_frag, ip6f_offlg)); IP6Q_UNLOCK(); return (IPPROTO_DONE); } } else if (fragoff + frgpartlen > IPV6_MAXPACKET) { icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, offset - sizeof(struct ip6_frag) + offsetof(struct ip6_frag, ip6f_offlg)); IP6Q_UNLOCK(); return (IPPROTO_DONE); } /* * If it's the first fragment, do the above check for each * fragment already stored in the reassembly queue. */ if (fragoff == 0) { for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; af6 = af6dwn) { af6dwn = af6->ip6af_down; if (q6->ip6q_unfrglen + af6->ip6af_off + af6->ip6af_frglen > IPV6_MAXPACKET) { struct mbuf *merr = IP6_REASS_MBUF(af6); struct ip6_hdr *ip6err; int erroff = af6->ip6af_offset; /* dequeue the fragment. */ frag6_deq(af6); free(af6, M_FTABLE); /* adjust pointer. */ ip6err = mtod(merr, struct ip6_hdr *); /* * Restore source and destination addresses * in the erroneous IPv6 header. */ ip6err->ip6_src = q6->ip6q_src; ip6err->ip6_dst = q6->ip6q_dst; icmp6_error(merr, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, erroff - sizeof(struct ip6_frag) + offsetof(struct ip6_frag, ip6f_offlg)); } } } ip6af = (struct ip6asfrag *)malloc(sizeof(struct ip6asfrag), M_FTABLE, M_NOWAIT); if (ip6af == NULL) goto dropfrag; bzero(ip6af, sizeof(*ip6af)); ip6af->ip6af_head = ip6->ip6_flow; ip6af->ip6af_len = ip6->ip6_plen; ip6af->ip6af_nxt = ip6->ip6_nxt; ip6af->ip6af_hlim = ip6->ip6_hlim; ip6af->ip6af_mff = ip6f->ip6f_offlg & IP6F_MORE_FRAG; ip6af->ip6af_off = fragoff; ip6af->ip6af_frglen = frgpartlen; ip6af->ip6af_offset = offset; IP6_REASS_MBUF(ip6af) = m; if (first_frag) { af6 = (struct ip6asfrag *)q6; goto insert; } /* * Handle ECN by comparing this segment with the first one; * if CE is set, do not lose CE. * drop if CE and not-ECT are mixed for the same packet. */ ecn = (ntohl(ip6->ip6_flow) >> 20) & IPTOS_ECN_MASK; ecn0 = (ntohl(q6->ip6q_down->ip6af_head) >> 20) & IPTOS_ECN_MASK; if (ecn == IPTOS_ECN_CE) { if (ecn0 == IPTOS_ECN_NOTECT) { free(ip6af, M_FTABLE); goto dropfrag; } if (ecn0 != IPTOS_ECN_CE) q6->ip6q_down->ip6af_head |= htonl(IPTOS_ECN_CE << 20); } if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT) { free(ip6af, M_FTABLE); goto dropfrag; } /* * Find a segment which begins after this one does. */ for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; af6 = af6->ip6af_down) if (af6->ip6af_off > ip6af->ip6af_off) break; #if 0 /* * If there is a preceding segment, it may provide some of * our data already. If so, drop the data from the incoming * segment. If it provides all of our data, drop us. */ if (af6->ip6af_up != (struct ip6asfrag *)q6) { i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen - ip6af->ip6af_off; if (i > 0) { if (i >= ip6af->ip6af_frglen) goto dropfrag; m_adj(IP6_REASS_MBUF(ip6af), i); ip6af->ip6af_off += i; ip6af->ip6af_frglen -= i; } } /* * While we overlap succeeding segments trim them or, * if they are completely covered, dequeue them. */ while (af6 != (struct ip6asfrag *)q6 && ip6af->ip6af_off + ip6af->ip6af_frglen > af6->ip6af_off) { i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off; if (i < af6->ip6af_frglen) { af6->ip6af_frglen -= i; af6->ip6af_off += i; m_adj(IP6_REASS_MBUF(af6), i); break; } af6 = af6->ip6af_down; m_freem(IP6_REASS_MBUF(af6->ip6af_up)); frag6_deq(af6->ip6af_up); } #else /* * If the incoming framgent overlaps some existing fragments in * the reassembly queue, drop it, since it is dangerous to override * existing fragments from a security point of view. * We don't know which fragment is the bad guy - here we trust * fragment that came in earlier, with no real reason. */ if (af6->ip6af_up != (struct ip6asfrag *)q6) { i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen - ip6af->ip6af_off; if (i > 0) { #if 0 /* suppress the noisy log */ log(LOG_ERR, "%d bytes of a fragment from %s " "overlaps the previous fragment\n", i, ip6_sprintf(&q6->ip6q_src)); #endif free(ip6af, M_FTABLE); goto dropfrag; } } if (af6 != (struct ip6asfrag *)q6) { i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off; if (i > 0) { #if 0 /* suppress the noisy log */ log(LOG_ERR, "%d bytes of a fragment from %s " "overlaps the succeeding fragment", i, ip6_sprintf(&q6->ip6q_src)); #endif free(ip6af, M_FTABLE); goto dropfrag; } } #endif insert: /* * Stick new segment in its place; * check for complete reassembly. * Move to front of packet queue, as we are * the most recently active fragmented packet. */ frag6_enq(ip6af, af6->ip6af_up); frag6_nfrags++; q6->ip6q_nfrag++; #if 0 /* xxx */ if (q6 != ip6q.ip6q_next) { frag6_remque(q6); frag6_insque(q6, &ip6q); } #endif next = 0; for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; af6 = af6->ip6af_down) { if (af6->ip6af_off != next) { IP6Q_UNLOCK(); return IPPROTO_DONE; } next += af6->ip6af_frglen; } if (af6->ip6af_up->ip6af_mff) { IP6Q_UNLOCK(); return IPPROTO_DONE; } /* * Reassembly is complete; concatenate fragments. */ ip6af = q6->ip6q_down; t = m = IP6_REASS_MBUF(ip6af); af6 = ip6af->ip6af_down; frag6_deq(ip6af); while (af6 != (struct ip6asfrag *)q6) { af6dwn = af6->ip6af_down; frag6_deq(af6); while (t->m_next) t = t->m_next; t->m_next = IP6_REASS_MBUF(af6); m_adj(t->m_next, af6->ip6af_offset); free(af6, M_FTABLE); af6 = af6dwn; } /* adjust offset to point where the original next header starts */ offset = ip6af->ip6af_offset - sizeof(struct ip6_frag); free(ip6af, M_FTABLE); ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_plen = htons((u_short)next + offset - sizeof(struct ip6_hdr)); ip6->ip6_src = q6->ip6q_src; ip6->ip6_dst = q6->ip6q_dst; nxt = q6->ip6q_nxt; #ifdef notyet *q6->ip6q_nxtp = (u_char)(nxt & 0xff); #endif /* * Delete frag6 header with as a few cost as possible. */ if (offset < m->m_len) { ovbcopy((caddr_t)ip6, (caddr_t)ip6 + sizeof(struct ip6_frag), offset); m->m_data += sizeof(struct ip6_frag); m->m_len -= sizeof(struct ip6_frag); } else { /* this comes with no copy if the boundary is on cluster */ if ((t = m_split(m, offset, M_DONTWAIT)) == NULL) { frag6_remque(q6); frag6_nfrags -= q6->ip6q_nfrag; free(q6, M_FTABLE); frag6_nfragpackets--; goto dropfrag; } m_adj(t, sizeof(struct ip6_frag)); m_cat(m, t); } /* * Store NXT to the original. */ { char *prvnxtp = ip6_get_prevhdr(m, offset); /* XXX */ *prvnxtp = nxt; } frag6_remque(q6); frag6_nfrags -= q6->ip6q_nfrag; free(q6, M_FTABLE); frag6_nfragpackets--; if (m->m_flags & M_PKTHDR) { /* Isn't it always true? */ int plen = 0; for (t = m; t; t = t->m_next) plen += t->m_len; m->m_pkthdr.len = plen; } ip6stat.ip6s_reassembled++; in6_ifstat_inc(dstifp, ifs6_reass_ok); /* * Tell launch routine the next header */ *mp = m; *offp = offset; IP6Q_UNLOCK(); return nxt; dropfrag: IP6Q_UNLOCK(); in6_ifstat_inc(dstifp, ifs6_reass_fail); ip6stat.ip6s_fragdropped++; m_freem(m); return IPPROTO_DONE; } /* * Free a fragment reassembly header and all * associated datagrams. */ void frag6_freef(q6) struct ip6q *q6; { struct ip6asfrag *af6, *down6; IP6Q_LOCK_ASSERT(); for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; af6 = down6) { struct mbuf *m = IP6_REASS_MBUF(af6); down6 = af6->ip6af_down; frag6_deq(af6); /* * Return ICMP time exceeded error for the 1st fragment. * Just free other fragments. */ if (af6->ip6af_off == 0) { struct ip6_hdr *ip6; /* adjust pointer */ ip6 = mtod(m, struct ip6_hdr *); /* restore source and destination addresses */ ip6->ip6_src = q6->ip6q_src; ip6->ip6_dst = q6->ip6q_dst; icmp6_error(m, ICMP6_TIME_EXCEEDED, ICMP6_TIME_EXCEED_REASSEMBLY, 0); } else m_freem(m); free(af6, M_FTABLE); } frag6_remque(q6); frag6_nfrags -= q6->ip6q_nfrag; free(q6, M_FTABLE); frag6_nfragpackets--; } /* * Put an ip fragment on a reassembly chain. * Like insque, but pointers in middle of structure. */ void frag6_enq(af6, up6) struct ip6asfrag *af6, *up6; { IP6Q_LOCK_ASSERT(); af6->ip6af_up = up6; af6->ip6af_down = up6->ip6af_down; up6->ip6af_down->ip6af_up = af6; up6->ip6af_down = af6; } /* * To frag6_enq as remque is to insque. */ void frag6_deq(af6) struct ip6asfrag *af6; { IP6Q_LOCK_ASSERT(); af6->ip6af_up->ip6af_down = af6->ip6af_down; af6->ip6af_down->ip6af_up = af6->ip6af_up; } void frag6_insque(new, old) struct ip6q *new, *old; { IP6Q_LOCK_ASSERT(); new->ip6q_prev = old; new->ip6q_next = old->ip6q_next; old->ip6q_next->ip6q_prev= new; old->ip6q_next = new; } void frag6_remque(p6) struct ip6q *p6; { IP6Q_LOCK_ASSERT(); p6->ip6q_prev->ip6q_next = p6->ip6q_next; p6->ip6q_next->ip6q_prev = p6->ip6q_prev; } /* * IPv6 reassembling timer processing; * if a timer expires on a reassembly * queue, discard it. */ void frag6_slowtimo() { struct ip6q *q6; +#if 0 + GIANT_REQUIRED; /* XXX bz: ip6_forward_rt */ +#endif + IP6Q_LOCK(); q6 = ip6q.ip6q_next; if (q6) while (q6 != &ip6q) { --q6->ip6q_ttl; q6 = q6->ip6q_next; if (q6->ip6q_prev->ip6q_ttl == 0) { ip6stat.ip6s_fragtimeout++; /* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */ frag6_freef(q6->ip6q_prev); } } /* * If we are over the maximum number of fragments * (due to the limit being lowered), drain off * enough to get down to the new limit. */ while (frag6_nfragpackets > (u_int)ip6_maxfragpackets && ip6q.ip6q_prev) { ip6stat.ip6s_fragoverflow++; /* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */ frag6_freef(ip6q.ip6q_prev); } IP6Q_UNLOCK(); #if 0 /* * Routing changes might produce a better route than we last used; * make sure we notice eventually, even if forwarding only for one * destination and the cache is never replaced. */ if (ip6_forward_rt.ro_rt) { RTFREE(ip6_forward_rt.ro_rt); ip6_forward_rt.ro_rt = 0; } if (ipsrcchk_rt.ro_rt) { RTFREE(ipsrcchk_rt.ro_rt); ipsrcchk_rt.ro_rt = 0; } #endif } /* * Drain off all datagram fragments. */ void frag6_drain() { if (IP6Q_TRYLOCK() == 0) return; while (ip6q.ip6q_next != &ip6q) { ip6stat.ip6s_fragdropped++; /* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */ frag6_freef(ip6q.ip6q_next); } IP6Q_UNLOCK(); } Index: head/sys/netinet6/ip6_forward.c =================================================================== --- head/sys/netinet6/ip6_forward.c (revision 158294) +++ head/sys/netinet6/ip6_forward.c (revision 158295) @@ -1,675 +1,677 @@ /* $FreeBSD$ */ /* $KAME: ip6_forward.c,v 1.69 2001/05/17 03:48:30 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. */ #include "opt_ip6fw.h" #include "opt_inet.h" #include "opt_inet6.h" #include "opt_ipsec.h" #include "opt_ipstealth.h" #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 #ifdef INET6 #include #endif #include #endif /* IPSEC */ #ifdef FAST_IPSEC #include #include #include #define IPSEC #endif /* FAST_IPSEC */ #include #include #include struct route_in6 ip6_forward_rt; /* * 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(m, srcrt) struct mbuf *m; int srcrt; { struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); struct sockaddr_in6 *dst = NULL; struct rtentry *rt = NULL; 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 + GIANT_REQUIRED; /* XXX bz: ip6_forward_rt */ + #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)) { #if !defined(FAST_IPSEC) ipsec6stat.in_polvio++; #endif 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)) { ip6stat.ip6s_cantforward++; /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ if (ip6_log_time + ip6_log_interval < time_second) { ip6_log_time = time_second; log(LOG_DEBUG, "cannot forward " "from %s to %s nxt %d received on %s\n", ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&ip6->ip6_dst), ip6->ip6_nxt, if_name(m->m_pkthdr.rcvif)); } m_freem(m); return; } #ifdef IPSTEALTH if (!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 = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, IP_FORWARDING, &error); if (sp == NULL) { ipsec6stat.out_inval++; 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. */ ipsec6stat.out_polvio++; 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"); 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; } ip6stat.ip6s_cantforward++; if (mcopy) { #if 0 /* XXX: what icmp ? */ #else m_freem(mcopy); #endif } m_freem(m); return; } if (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; } skip_ipsec: #endif /* IPSEC */ #ifdef IPSEC if (ipsecrt) goto skip_routing; #endif dst = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; if (!srcrt) { /* ip6_forward_rt.ro_dst.sin6_addr is equal to ip6->ip6_dst */ if (ip6_forward_rt.ro_rt == 0 || (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) == 0) { if (ip6_forward_rt.ro_rt) { RTFREE(ip6_forward_rt.ro_rt); ip6_forward_rt.ro_rt = 0; } /* this probably fails but give it a try again */ rtalloc((struct route *)&ip6_forward_rt); } if (ip6_forward_rt.ro_rt == 0) { 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); } m_freem(m); return; } } else if ((rt = ip6_forward_rt.ro_rt) == 0 || !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr)) { if (ip6_forward_rt.ro_rt) { RTFREE(ip6_forward_rt.ro_rt); ip6_forward_rt.ro_rt = 0; } bzero(dst, sizeof(*dst)); dst->sin6_len = sizeof(struct sockaddr_in6); dst->sin6_family = AF_INET6; dst->sin6_addr = ip6->ip6_dst; rtalloc((struct route *)&ip6_forward_rt); if (ip6_forward_rt.ro_rt == 0) { 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); } m_freem(m); return; } } rt = ip6_forward_rt.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 */ ip6stat.ip6s_cantforward++; ip6stat.ip6s_badscope++; m_freem(m); return; } if (in6_setscope(&src_in6, m->m_pkthdr.rcvif, &inzone)) { ip6stat.ip6s_cantforward++; ip6stat.ip6s_badscope++; m_freem(m); return; } if (inzone != outzone #ifdef IPSEC && !ipsecrt #endif ) { ip6stat.ip6s_cantforward++; ip6stat.ip6s_badscope++; in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard); if (ip6_log_time + ip6_log_interval < time_second) { ip6_log_time = time_second; log(LOG_DEBUG, "cannot forward " "src %s, dst %s, nxt %d, rcvif %s, outif %s\n", ip6_sprintf(&ip6->ip6_src), ip6_sprintf(&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); m_freem(m); return; } /* * 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) { ip6stat.ip6s_cantforward++; ip6stat.ip6s_badscope++; m_freem(m); return; } 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 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 = ipsec6_getpolicybyaddr(mcopy, IPSEC_DIR_OUTBOUND, IP_FORWARDING, &ipsecerror); if (sp) { ipsechdrsiz = ipsec6_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 icmp6_error(mcopy, ICMP6_PACKET_TOO_BIG, 0, mtu); } m_freem(m); return; } 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 (rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && #ifdef IPSEC !ipsecrt && #endif (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); m_freem(m); return; } type = ND_REDIRECT; } /* * Check with the firewall... */ if (ip6_fw_enable && ip6_fw_chk_ptr) { u_short port = 0; /* If ipfw says divert, we have to just drop packet */ if ((*ip6_fw_chk_ptr)(&ip6, rt->rt_ifp, &port, &m)) { m_freem(m); goto freecopy; } if (!m) goto freecopy; } /* * 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(&ip6->ip6_src), ip6_sprintf(&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(&inet6_pfil_hook)) goto pass; /* Run through list of hooks for output packets. */ error = pfil_run_hooks(&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); ip6stat.ip6s_cantforward++; } else { ip6stat.ip6s_forward++; in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); if (type) ip6stat.ip6s_redirectsent++; else { if (mcopy) goto freecopy; } } senderr: if (mcopy == NULL) return; switch (error) { case 0: if (type == ND_REDIRECT) { icmp6_redirect_output(mcopy, rt); return; } 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); return; freecopy: m_freem(mcopy); return; }