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 1.9 2007/05/07 13:00:16 hasso 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 #if 0 53 static int ip6_rthdr0 (struct mbuf *, struct ip6_hdr *, 54 struct ip6_rthdr0 *); 55 #endif 56 57 int 58 route6_input(struct mbuf **mp, int *offp, int 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 65 #ifndef PULLDOWN_TEST 66 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE); 67 ip6 = mtod(m, struct ip6_hdr *); 68 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off); 69 #else 70 ip6 = mtod(m, struct ip6_hdr *); 71 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 72 if (rh == NULL) { 73 ip6stat.ip6s_tooshort++; 74 return IPPROTO_DONE; 75 } 76 #endif 77 78 switch (rh->ip6r_type) { 79 #if 0 80 /* 81 * See http://www.secdev.org/conf/IPv6_RH_security-csw07.pdf 82 * for why IPV6_RTHDR_TYPE_0 is baned here. 83 * 84 * We return ICMPv6 parameter problem so that innocent people 85 * (not an attacker) would notice about the use of IPV6_RTHDR_TYPE_0. 86 * Since there's no amplification, and ICMPv6 error will be rate- 87 * controlled, it shouldn't cause any problem. 88 * If you are concerned about this, you may want to use the following 89 * code fragment: 90 * 91 * case IPV6_RTHDR_TYPE_0: 92 * m_freem(m); 93 * return (IPPROTO_DONE); 94 */ 95 case IPV6_RTHDR_TYPE_0: 96 rhlen = (rh->ip6r_len + 1) << 3; 97 #ifndef PULLDOWN_TEST 98 /* 99 * note on option length: 100 * due to IP6_EXTHDR_CHECK assumption, we cannot handle 101 * very big routing header (max rhlen == 2048). 102 */ 103 IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE); 104 #else 105 /* 106 * note on option length: 107 * maximum rhlen: 2048 108 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 109 * so, here we are assuming that m_pulldown can handle 110 * rhlen == 2048 case. this may not be a good thing to 111 * assume - we may want to avoid pulling it up altogether. 112 */ 113 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 114 if (rh == NULL) { 115 ip6stat.ip6s_tooshort++; 116 return IPPROTO_DONE; 117 } 118 #endif 119 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 120 return (IPPROTO_DONE); 121 break; 122 #endif 123 default: 124 /* unknown routing type */ 125 if (rh->ip6r_segleft == 0) { 126 rhlen = (rh->ip6r_len + 1) << 3; 127 break; /* Final dst. Just ignore the header. */ 128 } 129 ip6stat.ip6s_badoptions++; 130 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 131 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 132 return (IPPROTO_DONE); 133 } 134 135 *offp += rhlen; 136 return (rh->ip6r_nxt); 137 } 138 139 #if 0 140 /* 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 static int 147 ip6_rthdr0(struct mbuf *m, struct ip6_hdr *ip6, struct ip6_rthdr0 *rh0) 148 { 149 int addrs, index; 150 struct in6_addr *nextaddr, tmpaddr; 151 152 if (rh0->ip6r0_segleft == 0) 153 return (0); 154 155 if (rh0->ip6r0_len % 2 156 #ifdef COMPAT_RFC1883 157 || rh0->ip6r0_len > 46 158 #endif 159 ) { 160 /* 161 * Type 0 routing header can't contain more than 23 addresses. 162 * RFC 2462: this limitation was removed since strict/loose 163 * bitmap field was deleted. 164 */ 165 ip6stat.ip6s_badoptions++; 166 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 167 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 168 return (-1); 169 } 170 171 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 172 ip6stat.ip6s_badoptions++; 173 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 174 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 175 return (-1); 176 } 177 178 index = addrs - rh0->ip6r0_segleft; 179 rh0->ip6r0_segleft--; 180 /* note that ip6r0_addr does not exist in RFC2292bis */ 181 nextaddr = rh0->ip6r0_addr + index; 182 183 /* 184 * reject invalid addresses. be proactive about malicious use of 185 * IPv4 mapped/compat address. 186 * XXX need more checks? 187 */ 188 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 189 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 190 IN6_IS_ADDR_V4MAPPED(nextaddr) || 191 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 192 ip6stat.ip6s_badoptions++; 193 m_freem(m); 194 return (-1); 195 } 196 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 197 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 198 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 199 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 200 ip6stat.ip6s_badoptions++; 201 m_freem(m); 202 return (-1); 203 } 204 205 /* 206 * Swap the IPv6 destination address and nextaddr. Forward the packet. 207 */ 208 tmpaddr = *nextaddr; 209 *nextaddr = ip6->ip6_dst; 210 if (IN6_IS_ADDR_LINKLOCAL(nextaddr)) 211 nextaddr->s6_addr16[1] = 0; 212 ip6->ip6_dst = tmpaddr; 213 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) 214 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 215 216 #ifdef COMPAT_RFC1883 217 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 218 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 219 else 220 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 221 #else 222 ip6_forward(m, 1); 223 #endif 224 225 return (-1); /* m would be freed in ip6_forward() */ 226 } 227 #endif 228