1 /*- 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $KAME: route6.c,v 1.24 2001/03/14 03:07:05 itojun Exp $ 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_inet.h" 36 #include "opt_inet6.h" 37 38 #include <sys/param.h> 39 #include <sys/mbuf.h> 40 #include <sys/socket.h> 41 #include <sys/systm.h> 42 #include <sys/queue.h> 43 #include <sys/vimage.h> 44 45 #include <net/if.h> 46 47 #include <netinet/in.h> 48 #include <netinet6/in6_var.h> 49 #include <netinet/ip6.h> 50 #include <netinet6/ip6_var.h> 51 #include <netinet6/scope6_var.h> 52 53 #include <netinet/icmp6.h> 54 55 #if 0 56 static int ip6_rthdr0 __P((struct mbuf *, struct ip6_hdr *, 57 struct ip6_rthdr0 *)); 58 59 #endif /* Disable route header processing. */ 60 61 /* 62 * proto - is unused 63 */ 64 65 int 66 route6_input(struct mbuf **mp, int *offp, int proto) 67 { 68 struct ip6_hdr *ip6; 69 struct mbuf *m = *mp; 70 struct ip6_rthdr *rh; 71 int off = *offp, rhlen; 72 struct ip6aux *ip6a; 73 74 ip6a = ip6_findaux(m); 75 if (ip6a) { 76 /* XXX reject home-address option before rthdr */ 77 if (ip6a->ip6a_flags & IP6A_SWAP) { 78 V_ip6stat.ip6s_badoptions++; 79 m_freem(m); 80 return IPPROTO_DONE; 81 } 82 } 83 84 #ifndef PULLDOWN_TEST 85 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE); 86 ip6 = mtod(m, struct ip6_hdr *); 87 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off); 88 #else 89 ip6 = mtod(m, struct ip6_hdr *); 90 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 91 if (rh == NULL) { 92 V_ip6stat.ip6s_tooshort++; 93 return IPPROTO_DONE; 94 } 95 #endif 96 97 switch (rh->ip6r_type) { 98 #if 0 99 case IPV6_RTHDR_TYPE_0: 100 rhlen = (rh->ip6r_len + 1) << 3; 101 #ifndef PULLDOWN_TEST 102 /* 103 * note on option length: 104 * due to IP6_EXTHDR_CHECK assumption, we cannot handle 105 * very big routing header (max rhlen == 2048). 106 */ 107 IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE); 108 #else 109 /* 110 * note on option length: 111 * maximum rhlen: 2048 112 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 113 * so, here we are assuming that m_pulldown can handle 114 * rhlen == 2048 case. this may not be a good thing to 115 * assume - we may want to avoid pulling it up altogether. 116 */ 117 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 118 if (rh == NULL) { 119 V_ip6stat.ip6s_tooshort++; 120 return IPPROTO_DONE; 121 } 122 #endif 123 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 124 return (IPPROTO_DONE); 125 break; 126 #endif /* Disable route header 0 */ 127 default: 128 /* unknown routing type */ 129 if (rh->ip6r_segleft == 0) { 130 rhlen = (rh->ip6r_len + 1) << 3; 131 break; /* Final dst. Just ignore the header. */ 132 } 133 V_ip6stat.ip6s_badoptions++; 134 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 135 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 136 return (IPPROTO_DONE); 137 } 138 139 *offp += rhlen; 140 return (rh->ip6r_nxt); 141 } 142 143 /* 144 * Type0 routing header processing 145 * 146 * RFC2292 backward compatibility warning: no support for strict/loose bitmap, 147 * as it was dropped between RFC1883 and RFC2460. 148 */ 149 #if 0 150 static int 151 ip6_rthdr0(struct mbuf *m, struct ip6_hdr *ip6, struct ip6_rthdr0 *rh0) 152 { 153 int addrs, index; 154 struct in6_addr *nextaddr, tmpaddr; 155 struct in6_ifaddr *ifa; 156 157 if (rh0->ip6r0_segleft == 0) 158 return (0); 159 160 if (rh0->ip6r0_len % 2 161 #ifdef COMPAT_RFC1883 162 || rh0->ip6r0_len > 46 163 #endif 164 ) { 165 /* 166 * Type 0 routing header can't contain more than 23 addresses. 167 * RFC 2462: this limitation was removed since strict/loose 168 * bitmap field was deleted. 169 */ 170 V_ip6stat.ip6s_badoptions++; 171 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 172 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 173 return (-1); 174 } 175 176 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 177 V_ip6stat.ip6s_badoptions++; 178 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 179 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 180 return (-1); 181 } 182 183 index = addrs - rh0->ip6r0_segleft; 184 rh0->ip6r0_segleft--; 185 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index; 186 187 /* 188 * reject invalid addresses. be proactive about malicious use of 189 * IPv4 mapped/compat address. 190 * XXX need more checks? 191 */ 192 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 193 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 194 IN6_IS_ADDR_V4MAPPED(nextaddr) || 195 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 196 V_ip6stat.ip6s_badoptions++; 197 m_freem(m); 198 return (-1); 199 } 200 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 201 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 202 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 203 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 204 V_ip6stat.ip6s_badoptions++; 205 m_freem(m); 206 return (-1); 207 } 208 209 /* 210 * Determine the scope zone of the next hop, based on the interface 211 * of the current hop. [RFC4007, Section 9] 212 * Then disambiguate the scope zone for the next hop (if necessary). 213 */ 214 if ((ifa = ip6_getdstifaddr(m)) == NULL) 215 goto bad; 216 if (in6_setscope(nextaddr, ifa->ia_ifp, NULL) != 0) { 217 V_ip6stat.ip6s_badscope++; 218 goto bad; 219 } 220 221 /* 222 * Swap the IPv6 destination address and nextaddr. Forward the packet. 223 */ 224 tmpaddr = *nextaddr; 225 *nextaddr = ip6->ip6_dst; 226 in6_clearscope(nextaddr); /* XXX */ 227 ip6->ip6_dst = tmpaddr; 228 229 #ifdef COMPAT_RFC1883 230 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 231 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 232 else 233 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 234 #else 235 ip6_forward(m, 1); 236 #endif 237 238 return (-1); /* m would be freed in ip6_forward() */ 239 240 bad: 241 m_freem(m); 242 return (-1); 243 } 244 #endif 245