1/* $FreeBSD: src/sys/netinet6/route6.c,v 1.1.2.3 2001/07/03 11:01:55 ume Exp $ */ 2/* $KAME: route6.c,v 1.24 2001/03/14 03:07:05 itojun Exp $ */ 3 4/* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#include <sys/param.h> 34#include <sys/mbuf.h> 35#include <sys/socket.h> 36#include <sys/queue.h> 37#include <string.h> 38 39#include <net/if.h> 40#include <net/route.h> 41 42#include <netinet/in.h> 43#include <netinet6/in6_var.h> 44#include <netinet/ip6.h> 45#include <netinet6/ip6_var.h> 46 47#include <netinet/icmp6.h> 48 49#if IP6_RTHDR0_ALLOWED 50static int ip6_rthdr0(struct mbuf *, struct ip6_hdr *, 51 struct ip6_rthdr0 *); 52#endif /* IP6_RTHDR0_ALLOWED */ 53 54int 55route6_input(struct mbuf **mp, int *offp) 56{ 57 struct ip6_hdr *ip6; 58 struct mbuf *m = *mp; 59 struct ip6_rthdr *rh; 60 int off = *offp, rhlen; 61 struct ip6aux *ip6a; 62 63 ip6a = ip6_findaux(m); 64 if (ip6a) { 65 /* XXX reject home-address option before rthdr */ 66 if (ip6a->ip6a_flags & IP6A_SWAP) { 67 ip6stat.ip6s_badoptions++; 68 m_freem(m); 69 return IPPROTO_DONE; 70 } 71 } 72 73#ifndef PULLDOWN_TEST 74 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), return IPPROTO_DONE); 75 ip6 = mtod(m, struct ip6_hdr *); 76 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off); 77#else 78 ip6 = mtod(m, struct ip6_hdr *); 79 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 80 if (rh == NULL) { 81 ip6stat.ip6s_tooshort++; 82 return IPPROTO_DONE; 83 } 84#endif 85 86 switch (rh->ip6r_type) { 87#if IP6_RTHDR0_ALLOWED 88 case IPV6_RTHDR_TYPE_0: 89 rhlen = (rh->ip6r_len + 1) << 3; 90#ifndef PULLDOWN_TEST 91 /* 92 * note on option length: 93 * due to IP6_EXTHDR_CHECK assumption, we cannot handle 94 * very big routing header (max rhlen == 2048). 95 */ 96 IP6_EXTHDR_CHECK(m, off, rhlen, return IPPROTO_DONE); 97#else 98 /* 99 * note on option length: 100 * maximum rhlen: 2048 101 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 102 * so, here we are assuming that m_pulldown can handle 103 * rhlen == 2048 case. this may not be a good thing to 104 * assume - we may want to avoid pulling it up altogether. 105 */ 106 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 107 if (rh == NULL) { 108 ip6stat.ip6s_tooshort++; 109 return IPPROTO_DONE; 110 } 111#endif 112 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 113 return(IPPROTO_DONE); 114 break; 115#endif /* IP6_RTHDR0_ALLOWED */ 116 default: 117 /* unknown routing type */ 118 if (rh->ip6r_segleft == 0) { 119 rhlen = (rh->ip6r_len + 1) << 3; 120 break; /* Final dst. Just ignore the header. */ 121 } 122 ip6stat.ip6s_badoptions++; 123 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 124 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 125 return(IPPROTO_DONE); 126 } 127 128 *offp += rhlen; 129 return(rh->ip6r_nxt); 130} 131 132#if IP6_RTHDR0_ALLOWED 133/* 134 * Type0 routing header processing 135 * 136 * RFC2292 backward compatibility warning: no support for strict/loose bitmap, 137 * as it was dropped between RFC1883 and RFC2460. 138 */ 139static int 140ip6_rthdr0(m, ip6, rh0) 141 struct mbuf *m; 142 struct ip6_hdr *ip6; 143 struct ip6_rthdr0 *rh0; 144{ 145 int addrs, index; 146 struct in6_addr *nextaddr, tmpaddr; 147 struct route_in6 ip6forward_rt; 148 149 if (rh0->ip6r0_segleft == 0) 150 return(0); 151 152 if (rh0->ip6r0_len % 2 153#if COMPAT_RFC1883 154 || rh0->ip6r0_len > 46 155#endif 156 ) { 157 /* 158 * Type 0 routing header can't contain more than 23 addresses. 159 * RFC 2462: this limitation was removed since stict/loose 160 * bitmap field was deleted. 161 */ 162 ip6stat.ip6s_badoptions++; 163 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 164 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 165 return(-1); 166 } 167 168 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 169 ip6stat.ip6s_badoptions++; 170 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 171 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 172 return(-1); 173 } 174 175 index = addrs - rh0->ip6r0_segleft; 176 rh0->ip6r0_segleft--; 177 /* note that ip6r0_addr does not exist in RFC2292bis */ 178 nextaddr = rh0->ip6r0_addr + index; 179 180 /* 181 * reject invalid addresses. be proactive about malicious use of 182 * IPv4 mapped/compat address. 183 * XXX need more checks? 184 */ 185 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 186 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 187 IN6_IS_ADDR_V4MAPPED(nextaddr) || 188 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 189 ip6stat.ip6s_badoptions++; 190 m_freem(m); 191 return(-1); 192 } 193 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 194 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 195 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 196 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 197 ip6stat.ip6s_badoptions++; 198 m_freem(m); 199 return(-1); 200 } 201 202 /* 203 * Swap the IPv6 destination address and nextaddr. Forward the packet. 204 */ 205 tmpaddr = *nextaddr; 206 *nextaddr = ip6->ip6_dst; 207 if (IN6_IS_ADDR_LINKLOCAL(nextaddr)) 208 nextaddr->s6_addr16[1] = 0; 209 ip6->ip6_dst = tmpaddr; 210 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) 211 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 212 213 /* 214 * Don't use the globally cached route to forward packet having 215 * Type 0 routing header(s); instead, do an explicit lookup using 216 * a local route entry variable, in case the next address in the 217 * packet is bogus (which would otherwise unnecessarily invalidate 218 * the globally cached route). 219 */ 220 bzero(&ip6forward_rt, sizeof (ip6forward_rt)); 221 222#if COMPAT_RFC1883 223 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 224 ip6_forward(m, &ip6forward_rt, IPV6_SRCRT_NEIGHBOR, 0); 225 else 226 ip6_forward(m, &ip6forward_rt, IPV6_SRCRT_NOTNEIGHBOR, 0); 227#else 228 ip6_forward(m, &ip6forward_rt, 1, 0); 229#endif 230 231 /* Release reference to the looked up route */ 232 if (ip6forward_rt.ro_rt != NULL) { 233 rtfree(ip6forward_rt.ro_rt); 234 ip6forward_rt.ro_rt = NULL; 235 } 236 237 return(-1); /* m would be freed in ip6_forward() */ 238} 239#endif /* IP6_RTHDR0_ALLOWED */ 240 241