1 /* $FreeBSD$ */ 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 "opt_inet.h" 34 #include "opt_inet6.h" 35 36 #include <sys/param.h> 37 #include <sys/mbuf.h> 38 #include <sys/socket.h> 39 #include <sys/systm.h> 40 #include <sys/queue.h> 41 42 #include <net/if.h> 43 44 #include <netinet/in.h> 45 #include <netinet6/in6_var.h> 46 #include <netinet/ip6.h> 47 #include <netinet6/ip6_var.h> 48 49 #include <netinet/icmp6.h> 50 51 static int ip6_rthdr0 __P((struct mbuf *, struct ip6_hdr *, 52 struct ip6_rthdr0 *)); 53 54 int 55 route6_input(mp, offp, proto) 56 struct mbuf **mp; 57 int *offp, proto; /* proto is unused */ 58 { 59 struct ip6_hdr *ip6; 60 struct mbuf *m = *mp; 61 struct ip6_rthdr *rh; 62 int off = *offp, rhlen; 63 struct ip6aux *ip6a; 64 65 ip6a = ip6_findaux(m); 66 if (ip6a) { 67 /* XXX reject home-address option before rthdr */ 68 if (ip6a->ip6a_flags & IP6A_SWAP) { 69 ip6stat.ip6s_badoptions++; 70 m_freem(m); 71 return IPPROTO_DONE; 72 } 73 } 74 75 #ifndef PULLDOWN_TEST 76 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE); 77 ip6 = mtod(m, struct ip6_hdr *); 78 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off); 79 #else 80 ip6 = mtod(m, struct ip6_hdr *); 81 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 82 if (rh == NULL) { 83 ip6stat.ip6s_tooshort++; 84 return IPPROTO_DONE; 85 } 86 #endif 87 88 switch (rh->ip6r_type) { 89 case IPV6_RTHDR_TYPE_0: 90 rhlen = (rh->ip6r_len + 1) << 3; 91 #ifndef PULLDOWN_TEST 92 /* 93 * note on option length: 94 * due to IP6_EXTHDR_CHECK assumption, we cannot handle 95 * very big routing header (max rhlen == 2048). 96 */ 97 IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE); 98 #else 99 /* 100 * note on option length: 101 * maximum rhlen: 2048 102 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 103 * so, here we are assuming that m_pulldown can handle 104 * rhlen == 2048 case. this may not be a good thing to 105 * assume - we may want to avoid pulling it up altogether. 106 */ 107 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 108 if (rh == NULL) { 109 ip6stat.ip6s_tooshort++; 110 return IPPROTO_DONE; 111 } 112 #endif 113 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 114 return (IPPROTO_DONE); 115 break; 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 /* 133 * Type0 routing header processing 134 * 135 * RFC2292 backward compatibility warning: no support for strict/loose bitmap, 136 * as it was dropped between RFC1883 and RFC2460. 137 */ 138 static int 139 ip6_rthdr0(m, ip6, rh0) 140 struct mbuf *m; 141 struct ip6_hdr *ip6; 142 struct ip6_rthdr0 *rh0; 143 { 144 int addrs, index; 145 struct in6_addr *nextaddr, tmpaddr; 146 147 if (rh0->ip6r0_segleft == 0) 148 return (0); 149 150 if (rh0->ip6r0_len % 2 151 #ifdef COMPAT_RFC1883 152 || rh0->ip6r0_len > 46 153 #endif 154 ) { 155 /* 156 * Type 0 routing header can't contain more than 23 addresses. 157 * RFC 2462: this limitation was removed since strict/loose 158 * bitmap field was deleted. 159 */ 160 ip6stat.ip6s_badoptions++; 161 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 162 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 163 return (-1); 164 } 165 166 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 167 ip6stat.ip6s_badoptions++; 168 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 169 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 170 return (-1); 171 } 172 173 index = addrs - rh0->ip6r0_segleft; 174 rh0->ip6r0_segleft--; 175 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index; 176 177 /* 178 * reject invalid addresses. be proactive about malicious use of 179 * IPv4 mapped/compat address. 180 * XXX need more checks? 181 */ 182 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 183 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 184 IN6_IS_ADDR_V4MAPPED(nextaddr) || 185 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 186 ip6stat.ip6s_badoptions++; 187 m_freem(m); 188 return (-1); 189 } 190 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 191 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 192 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 193 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 194 ip6stat.ip6s_badoptions++; 195 m_freem(m); 196 return (-1); 197 } 198 199 /* 200 * Swap the IPv6 destination address and nextaddr. Forward the packet. 201 */ 202 tmpaddr = *nextaddr; 203 *nextaddr = ip6->ip6_dst; 204 if (IN6_IS_ADDR_LINKLOCAL(nextaddr)) 205 nextaddr->s6_addr16[1] = 0; 206 ip6->ip6_dst = tmpaddr; 207 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) 208 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 209 210 #ifdef COMPAT_RFC1883 211 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 212 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 213 else 214 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 215 #else 216 ip6_forward(m, 1); 217 #endif 218 219 return (-1); /* m would be freed in ip6_forward() */ 220 } 221