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 #include <netinet6/scope6_var.h> 49 50 #include <netinet/icmp6.h> 51 52 static int ip6_rthdr0 __P((struct mbuf *, struct ip6_hdr *, 53 struct ip6_rthdr0 *)); 54 55 int 56 route6_input(mp, offp, proto) 57 struct mbuf **mp; 58 int *offp, proto; /* proto is unused */ 59 { 60 struct ip6_hdr *ip6; 61 struct mbuf *m = *mp; 62 struct ip6_rthdr *rh; 63 int off = *offp, rhlen; 64 struct ip6aux *ip6a; 65 66 ip6a = ip6_findaux(m); 67 if (ip6a) { 68 /* XXX reject home-address option before rthdr */ 69 if (ip6a->ip6a_flags & IP6A_SWAP) { 70 ip6stat.ip6s_badoptions++; 71 m_freem(m); 72 return IPPROTO_DONE; 73 } 74 } 75 76 #ifndef PULLDOWN_TEST 77 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE); 78 ip6 = mtod(m, struct ip6_hdr *); 79 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off); 80 #else 81 ip6 = mtod(m, struct ip6_hdr *); 82 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 83 if (rh == NULL) { 84 ip6stat.ip6s_tooshort++; 85 return IPPROTO_DONE; 86 } 87 #endif 88 89 switch (rh->ip6r_type) { 90 case IPV6_RTHDR_TYPE_0: 91 rhlen = (rh->ip6r_len + 1) << 3; 92 #ifndef PULLDOWN_TEST 93 /* 94 * note on option length: 95 * due to IP6_EXTHDR_CHECK assumption, we cannot handle 96 * very big routing header (max rhlen == 2048). 97 */ 98 IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE); 99 #else 100 /* 101 * note on option length: 102 * maximum rhlen: 2048 103 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 104 * so, here we are assuming that m_pulldown can handle 105 * rhlen == 2048 case. this may not be a good thing to 106 * assume - we may want to avoid pulling it up altogether. 107 */ 108 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 109 if (rh == NULL) { 110 ip6stat.ip6s_tooshort++; 111 return IPPROTO_DONE; 112 } 113 #endif 114 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 115 return (IPPROTO_DONE); 116 break; 117 default: 118 /* unknown routing type */ 119 if (rh->ip6r_segleft == 0) { 120 rhlen = (rh->ip6r_len + 1) << 3; 121 break; /* Final dst. Just ignore the header. */ 122 } 123 ip6stat.ip6s_badoptions++; 124 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 125 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 126 return (IPPROTO_DONE); 127 } 128 129 *offp += rhlen; 130 return (rh->ip6r_nxt); 131 } 132 133 /* 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 */ 139 static int 140 ip6_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 in6_ifaddr *ifa; 148 149 if (rh0->ip6r0_segleft == 0) 150 return (0); 151 152 if (rh0->ip6r0_len % 2 153 #ifdef 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 strict/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 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index; 178 179 /* 180 * reject invalid addresses. be proactive about malicious use of 181 * IPv4 mapped/compat address. 182 * XXX need more checks? 183 */ 184 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 185 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 186 IN6_IS_ADDR_V4MAPPED(nextaddr) || 187 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 188 ip6stat.ip6s_badoptions++; 189 m_freem(m); 190 return (-1); 191 } 192 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 193 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 194 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 195 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 196 ip6stat.ip6s_badoptions++; 197 m_freem(m); 198 return (-1); 199 } 200 201 /* 202 * Determine the scope zone of the next hop, based on the interface 203 * of the current hop. [RFC4007, Section 9] 204 * Then disambiguate the scope zone for the next hop (if necessary). 205 */ 206 if ((ifa = ip6_getdstifaddr(m)) == NULL) 207 goto bad; 208 if (in6_setscope(nextaddr, ifa->ia_ifp, NULL) != 0) { 209 ip6stat.ip6s_badscope++; 210 goto bad; 211 } 212 213 /* 214 * Swap the IPv6 destination address and nextaddr. Forward the packet. 215 */ 216 tmpaddr = *nextaddr; 217 *nextaddr = ip6->ip6_dst; 218 in6_clearscope(nextaddr); /* XXX */ 219 ip6->ip6_dst = tmpaddr; 220 221 #ifdef COMPAT_RFC1883 222 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 223 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 224 else 225 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 226 #else 227 ip6_forward(m, 1); 228 #endif 229 230 return (-1); /* m would be freed in ip6_forward() */ 231 232 bad: 233 m_freem(m); 234 return (-1); 235 } 236