1 /* $NetBSD: route6.c,v 1.8 2001/02/10 04:14:29 itojun Exp $ */ 2 /* $KAME: route6.c,v 1.22 2000/12/03 00:54:00 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 <sys/param.h> 34 #include <sys/mbuf.h> 35 #include <sys/socket.h> 36 #include <sys/systm.h> 37 #include <sys/queue.h> 38 39 #include <net/if.h> 40 41 #include <netinet/in.h> 42 #include <netinet6/in6_var.h> 43 #include <netinet/ip6.h> 44 #include <netinet6/ip6_var.h> 45 46 #include <netinet/icmp6.h> 47 48 static int ip6_rthdr0 __P((struct mbuf *, struct ip6_hdr *, 49 struct ip6_rthdr0 *)); 50 51 int 52 route6_input(mp, offp, proto) 53 struct mbuf **mp; 54 int *offp, proto; /* proto is unused */ 55 { 56 struct ip6_hdr *ip6; 57 struct mbuf *m = *mp; 58 struct ip6_rthdr *rh; 59 int off = *offp, rhlen; 60 61 #ifndef PULLDOWN_TEST 62 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE); 63 ip6 = mtod(m, struct ip6_hdr *); 64 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off); 65 #else 66 ip6 = mtod(m, struct ip6_hdr *); 67 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 68 if (rh == NULL) { 69 ip6stat.ip6s_tooshort++; 70 return IPPROTO_DONE; 71 } 72 #endif 73 74 switch (rh->ip6r_type) { 75 case IPV6_RTHDR_TYPE_0: 76 rhlen = (rh->ip6r_len + 1) << 3; 77 #ifndef PULLDOWN_TEST 78 /* 79 * note on option length: 80 * due to IP6_EXTHDR_CHECK assumption, we cannot handle 81 * very big routing header (max rhlen == 2048). 82 */ 83 IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE); 84 #else 85 /* 86 * note on option length: 87 * maximum rhlen: 2048 88 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 89 * so, here we are assuming that m_pulldown can handle 90 * rhlen == 2048 case. this may not be a good thing to 91 * assume - we may want to avoid pulling it up altogether. 92 */ 93 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 94 if (rh == NULL) { 95 ip6stat.ip6s_tooshort++; 96 return IPPROTO_DONE; 97 } 98 #endif 99 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 100 return(IPPROTO_DONE); 101 break; 102 default: 103 /* unknown routing type */ 104 if (rh->ip6r_segleft == 0) { 105 rhlen = (rh->ip6r_len + 1) << 3; 106 break; /* Final dst. Just ignore the header. */ 107 } 108 ip6stat.ip6s_badoptions++; 109 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 110 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 111 return(IPPROTO_DONE); 112 } 113 114 *offp += rhlen; 115 return(rh->ip6r_nxt); 116 } 117 118 /* 119 * Type0 routing header processing 120 */ 121 static int 122 ip6_rthdr0(m, ip6, rh0) 123 struct mbuf *m; 124 struct ip6_hdr *ip6; 125 struct ip6_rthdr0 *rh0; 126 { 127 int addrs, index; 128 struct in6_addr *nextaddr, tmpaddr; 129 130 if (rh0->ip6r0_segleft == 0) 131 return(0); 132 133 if (rh0->ip6r0_len % 2 134 #ifdef COMPAT_RFC1883 135 || rh0->ip6r0_len > 46 136 #endif 137 ) { 138 /* 139 * Type 0 routing header can't contain more than 23 addresses. 140 * RFC 2462: this limitation was removed since stict/loose 141 * bitmap field was deleted. 142 */ 143 ip6stat.ip6s_badoptions++; 144 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 145 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 146 return(-1); 147 } 148 149 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 150 ip6stat.ip6s_badoptions++; 151 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 152 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 153 return(-1); 154 } 155 156 index = addrs - rh0->ip6r0_segleft; 157 rh0->ip6r0_segleft--; 158 nextaddr = rh0->ip6r0_addr + index; 159 160 /* 161 * reject invalid addresses. be proactive about malicious use of 162 * IPv4 mapped/compat address. 163 * XXX need more checks? 164 */ 165 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 166 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 167 IN6_IS_ADDR_V4MAPPED(nextaddr) || 168 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 169 ip6stat.ip6s_badoptions++; 170 m_freem(m); 171 return(-1); 172 } 173 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 174 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 175 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 176 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 177 ip6stat.ip6s_badoptions++; 178 m_freem(m); 179 return(-1); 180 } 181 182 /* 183 * Swap the IPv6 destination address and nextaddr. Forward the packet. 184 */ 185 tmpaddr = *nextaddr; 186 *nextaddr = ip6->ip6_dst; 187 if (IN6_IS_ADDR_LINKLOCAL(nextaddr)) 188 nextaddr->s6_addr16[1] = 0; 189 ip6->ip6_dst = tmpaddr; 190 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) 191 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 192 193 #ifdef COMPAT_RFC1883 194 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 195 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 196 else 197 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 198 #else 199 ip6_forward(m, 1); 200 #endif 201 202 return(-1); /* m would be freed in ip6_forward() */ 203 } 204