1 /* $FreeBSD: src/sys/netinet6/route6.c,v 1.1.2.5 2003/01/23 21:06:47 sam Exp $ */ 2 /* $DragonFly: src/sys/netinet6/route6.c,v 1.4 2004/05/20 18:30:36 cpressey Exp $ */ 3 /* $KAME: route6.c,v 1.24 2001/03/14 03:07:05 itojun Exp $ */ 4 5 /* 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include "opt_inet.h" 35 #include "opt_inet6.h" 36 37 #include <sys/param.h> 38 #include <sys/mbuf.h> 39 #include <sys/socket.h> 40 #include <sys/systm.h> 41 #include <sys/queue.h> 42 43 #include <net/if.h> 44 45 #include <netinet/in.h> 46 #include <netinet6/in6_var.h> 47 #include <netinet/ip6.h> 48 #include <netinet6/ip6_var.h> 49 50 #include <netinet/icmp6.h> 51 52 static int ip6_rthdr0 (struct mbuf *, struct ip6_hdr *, 53 struct ip6_rthdr0 *); 54 55 int 56 route6_input(struct mbuf **mp, int *offp, int proto) /* proto is unused */ 57 { 58 struct ip6_hdr *ip6; 59 struct mbuf *m = *mp; 60 struct ip6_rthdr *rh; 61 int off = *offp, rhlen; 62 struct ip6aux *ip6a; 63 64 ip6a = ip6_findaux(m); 65 if (ip6a) { 66 /* XXX reject home-address option before rthdr */ 67 if (ip6a->ip6a_flags & IP6A_SWAP) { 68 ip6stat.ip6s_badoptions++; 69 m_freem(m); 70 return IPPROTO_DONE; 71 } 72 } 73 74 #ifndef PULLDOWN_TEST 75 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE); 76 ip6 = mtod(m, struct ip6_hdr *); 77 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off); 78 #else 79 ip6 = mtod(m, struct ip6_hdr *); 80 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 81 if (rh == NULL) { 82 ip6stat.ip6s_tooshort++; 83 return IPPROTO_DONE; 84 } 85 #endif 86 87 switch (rh->ip6r_type) { 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, 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 default: 116 /* unknown routing type */ 117 if (rh->ip6r_segleft == 0) { 118 rhlen = (rh->ip6r_len + 1) << 3; 119 break; /* Final dst. Just ignore the header. */ 120 } 121 ip6stat.ip6s_badoptions++; 122 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 123 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 124 return(IPPROTO_DONE); 125 } 126 127 *offp += rhlen; 128 return(rh->ip6r_nxt); 129 } 130 131 /* 132 * Type0 routing header processing 133 * 134 * RFC2292 backward compatibility warning: no support for strict/loose bitmap, 135 * as it was dropped between RFC1883 and RFC2460. 136 */ 137 static int 138 ip6_rthdr0(struct mbuf *m, struct ip6_hdr *ip6, struct ip6_rthdr0 *rh0) 139 { 140 int addrs, index; 141 struct in6_addr *nextaddr, tmpaddr; 142 143 if (rh0->ip6r0_segleft == 0) 144 return(0); 145 146 if (rh0->ip6r0_len % 2 147 #ifdef COMPAT_RFC1883 148 || rh0->ip6r0_len > 46 149 #endif 150 ) { 151 /* 152 * Type 0 routing header can't contain more than 23 addresses. 153 * RFC 2462: this limitation was removed since strict/loose 154 * bitmap field was deleted. 155 */ 156 ip6stat.ip6s_badoptions++; 157 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 158 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 159 return(-1); 160 } 161 162 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 163 ip6stat.ip6s_badoptions++; 164 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 165 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 166 return(-1); 167 } 168 169 index = addrs - rh0->ip6r0_segleft; 170 rh0->ip6r0_segleft--; 171 /* note that ip6r0_addr does not exist in RFC2292bis */ 172 nextaddr = rh0->ip6r0_addr + index; 173 174 /* 175 * reject invalid addresses. be proactive about malicious use of 176 * IPv4 mapped/compat address. 177 * XXX need more checks? 178 */ 179 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 180 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 181 IN6_IS_ADDR_V4MAPPED(nextaddr) || 182 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 183 ip6stat.ip6s_badoptions++; 184 m_freem(m); 185 return(-1); 186 } 187 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 188 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 189 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 190 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 191 ip6stat.ip6s_badoptions++; 192 m_freem(m); 193 return(-1); 194 } 195 196 /* 197 * Swap the IPv6 destination address and nextaddr. Forward the packet. 198 */ 199 tmpaddr = *nextaddr; 200 *nextaddr = ip6->ip6_dst; 201 if (IN6_IS_ADDR_LINKLOCAL(nextaddr)) 202 nextaddr->s6_addr16[1] = 0; 203 ip6->ip6_dst = tmpaddr; 204 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) 205 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 206 207 #ifdef COMPAT_RFC1883 208 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 209 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 210 else 211 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 212 #else 213 ip6_forward(m, 1); 214 #endif 215 216 return(-1); /* m would be freed in ip6_forward() */ 217 } 218