route6.c revision 171259
1/* $FreeBSD: head/sys/netinet6/route6.c 171259 2007-07-05 16:23:49Z delphij $ */ 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#if 0 53static int ip6_rthdr0 __P((struct mbuf *, struct ip6_hdr *, 54 struct ip6_rthdr0 *)); 55 56#endif /* Disable route header processing. */ 57 58/* 59 * proto - is unused 60 */ 61 62int 63route6_input(struct mbuf **mp, int *offp, int proto) 64{ 65 struct ip6_hdr *ip6; 66 struct mbuf *m = *mp; 67 struct ip6_rthdr *rh; 68 int off = *offp, rhlen; 69 struct ip6aux *ip6a; 70 71 ip6a = ip6_findaux(m); 72 if (ip6a) { 73 /* XXX reject home-address option before rthdr */ 74 if (ip6a->ip6a_flags & IP6A_SWAP) { 75 ip6stat.ip6s_badoptions++; 76 m_freem(m); 77 return IPPROTO_DONE; 78 } 79 } 80 81#ifndef PULLDOWN_TEST 82 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE); 83 ip6 = mtod(m, struct ip6_hdr *); 84 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off); 85#else 86 ip6 = mtod(m, struct ip6_hdr *); 87 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 88 if (rh == NULL) { 89 ip6stat.ip6s_tooshort++; 90 return IPPROTO_DONE; 91 } 92#endif 93 94 switch (rh->ip6r_type) { 95#if 0 96 case IPV6_RTHDR_TYPE_0: 97 rhlen = (rh->ip6r_len + 1) << 3; 98#ifndef PULLDOWN_TEST 99 /* 100 * note on option length: 101 * due to IP6_EXTHDR_CHECK assumption, we cannot handle 102 * very big routing header (max rhlen == 2048). 103 */ 104 IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE); 105#else 106 /* 107 * note on option length: 108 * maximum rhlen: 2048 109 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 110 * so, here we are assuming that m_pulldown can handle 111 * rhlen == 2048 case. this may not be a good thing to 112 * assume - we may want to avoid pulling it up altogether. 113 */ 114 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 115 if (rh == NULL) { 116 ip6stat.ip6s_tooshort++; 117 return IPPROTO_DONE; 118 } 119#endif 120 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 121 return (IPPROTO_DONE); 122 break; 123#endif /* Disable route header 0 */ 124 default: 125 /* unknown routing type */ 126 if (rh->ip6r_segleft == 0) { 127 rhlen = (rh->ip6r_len + 1) << 3; 128 break; /* Final dst. Just ignore the header. */ 129 } 130 ip6stat.ip6s_badoptions++; 131 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 132 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 133 return (IPPROTO_DONE); 134 } 135 136 *offp += rhlen; 137 return (rh->ip6r_nxt); 138} 139 140/* 141 * Type0 routing header processing 142 * 143 * RFC2292 backward compatibility warning: no support for strict/loose bitmap, 144 * as it was dropped between RFC1883 and RFC2460. 145 */ 146#if 0 147static int 148ip6_rthdr0(struct mbuf *m, struct ip6_hdr *ip6, struct ip6_rthdr0 *rh0) 149{ 150 int addrs, index; 151 struct in6_addr *nextaddr, tmpaddr; 152 struct in6_ifaddr *ifa; 153 154 if (rh0->ip6r0_segleft == 0) 155 return (0); 156 157 if (rh0->ip6r0_len % 2 158#ifdef COMPAT_RFC1883 159 || rh0->ip6r0_len > 46 160#endif 161 ) { 162 /* 163 * Type 0 routing header can't contain more than 23 addresses. 164 * RFC 2462: this limitation was removed since strict/loose 165 * bitmap field was deleted. 166 */ 167 ip6stat.ip6s_badoptions++; 168 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 169 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 170 return (-1); 171 } 172 173 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 174 ip6stat.ip6s_badoptions++; 175 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 176 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 177 return (-1); 178 } 179 180 index = addrs - rh0->ip6r0_segleft; 181 rh0->ip6r0_segleft--; 182 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index; 183 184 /* 185 * reject invalid addresses. be proactive about malicious use of 186 * IPv4 mapped/compat address. 187 * XXX need more checks? 188 */ 189 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 190 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 191 IN6_IS_ADDR_V4MAPPED(nextaddr) || 192 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 193 ip6stat.ip6s_badoptions++; 194 m_freem(m); 195 return (-1); 196 } 197 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 198 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 199 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 200 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 201 ip6stat.ip6s_badoptions++; 202 m_freem(m); 203 return (-1); 204 } 205 206 /* 207 * Determine the scope zone of the next hop, based on the interface 208 * of the current hop. [RFC4007, Section 9] 209 * Then disambiguate the scope zone for the next hop (if necessary). 210 */ 211 if ((ifa = ip6_getdstifaddr(m)) == NULL) 212 goto bad; 213 if (in6_setscope(nextaddr, ifa->ia_ifp, NULL) != 0) { 214 ip6stat.ip6s_badscope++; 215 goto bad; 216 } 217 218 /* 219 * Swap the IPv6 destination address and nextaddr. Forward the packet. 220 */ 221 tmpaddr = *nextaddr; 222 *nextaddr = ip6->ip6_dst; 223 in6_clearscope(nextaddr); /* XXX */ 224 ip6->ip6_dst = tmpaddr; 225 226#ifdef COMPAT_RFC1883 227 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 228 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 229 else 230 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 231#else 232 ip6_forward(m, 1); 233#endif 234 235 return (-1); /* m would be freed in ip6_forward() */ 236 237 bad: 238 m_freem(m); 239 return (-1); 240} 241#endif 242