1 /* $NetBSD: route6.c,v 1.21 2007/10/29 16:54:43 dyoung 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/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: route6.c,v 1.21 2007/10/29 16:54:43 dyoung Exp $"); 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 53 static int ip6_rthdr0(struct mbuf *, struct ip6_hdr *, struct ip6_rthdr0 *); 54 #endif 55 56 int 57 route6_input(struct mbuf **mp, int *offp, int proto) 58 { 59 struct ip6_hdr *ip6; 60 struct mbuf *m = *mp; 61 struct ip6_rthdr *rh; 62 int off = *offp, rhlen; 63 64 ip6 = mtod(m, struct ip6_hdr *); 65 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 66 if (rh == NULL) { 67 ip6stat.ip6s_tooshort++; 68 return IPPROTO_DONE; 69 } 70 71 switch (rh->ip6r_type) { 72 #if 0 73 /* 74 * See http://www.secdev.org/conf/IPv6_RH_security-csw07.pdf 75 * for why IPV6_RTHDR_TYPE_0 is banned here. 76 * 77 * We return ICMPv6 parameter problem so that innocent people 78 * (not an attacker) would notice about the use of IPV6_RTHDR_TYPE_0. 79 * Since there's no amplification, and ICMPv6 error will be rate- 80 * controlled, it shouldn't cause any problem. 81 * If you are concerned about this, you may want to use the following 82 * code fragment: 83 * 84 * case IPV6_RTHDR_TYPE_0: 85 * m_freem(m); 86 * return (IPPROTO_DONE); 87 */ 88 case IPV6_RTHDR_TYPE_0: 89 rhlen = (rh->ip6r_len + 1) << 3; 90 /* 91 * note on option length: 92 * maximum rhlen: 2048 93 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 94 * so, here we are assuming that m_pulldown can handle 95 * rhlen == 2048 case. this may not be a good thing to 96 * assume - we may want to avoid pulling it up altogether. 97 */ 98 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 99 if (rh == NULL) { 100 ip6stat.ip6s_tooshort++; 101 return IPPROTO_DONE; 102 } 103 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 104 return (IPPROTO_DONE); 105 break; 106 #endif 107 default: 108 /* unknown routing type */ 109 if (rh->ip6r_segleft == 0) { 110 rhlen = (rh->ip6r_len + 1) << 3; 111 break; /* Final dst. Just ignore the header. */ 112 } 113 ip6stat.ip6s_badoptions++; 114 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 115 (char *)&rh->ip6r_type - (char *)ip6); 116 return (IPPROTO_DONE); 117 } 118 119 *offp += rhlen; 120 return (rh->ip6r_nxt); 121 } 122 123 #if 0 124 /* 125 * Type0 routing header processing 126 * 127 * RFC2292 backward compatibility warning: no support for strict/loose bitmap, 128 * as it was dropped between RFC1883 and RFC2460. 129 */ 130 static int 131 ip6_rthdr0(struct mbuf *m, struct ip6_hdr *ip6, 132 struct ip6_rthdr0 *rh0) 133 { 134 int addrs, index; 135 struct in6_addr *nextaddr, tmpaddr; 136 const struct ip6aux *ip6a; 137 138 if (rh0->ip6r0_segleft == 0) 139 return (0); 140 141 if (rh0->ip6r0_len % 2 142 #ifdef COMPAT_RFC1883 143 || rh0->ip6r0_len > 46 144 #endif 145 ) { 146 /* 147 * Type 0 routing header can't contain more than 23 addresses. 148 * RFC 2462: this limitation was removed since strict/loose 149 * bitmap field was deleted. 150 */ 151 ip6stat.ip6s_badoptions++; 152 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 153 (char *)&rh0->ip6r0_len - (char *)ip6); 154 return (-1); 155 } 156 157 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 158 ip6stat.ip6s_badoptions++; 159 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 160 (char *)&rh0->ip6r0_segleft - (char *)ip6); 161 return (-1); 162 } 163 164 index = addrs - rh0->ip6r0_segleft; 165 rh0->ip6r0_segleft--; 166 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index; 167 168 /* 169 * reject invalid addresses. be proactive about malicious use of 170 * IPv4 mapped/compat address. 171 * XXX need more checks? 172 */ 173 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 174 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 175 IN6_IS_ADDR_V4MAPPED(nextaddr) || 176 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 177 ip6stat.ip6s_badoptions++; 178 goto bad; 179 } 180 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 181 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 182 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 183 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 184 ip6stat.ip6s_badoptions++; 185 goto bad; 186 } 187 188 /* 189 * Determine the scope zone of the next hop, based on the interface 190 * of the current hop. [RFC4007, Section 9] 191 * Then disambiguate the scope zone for the next hop (if necessary). 192 */ 193 if ((ip6a = ip6_getdstifaddr(m)) == NULL) 194 goto bad; 195 if (in6_setzoneid(nextaddr, ip6a->ip6a_scope_id) != 0) { 196 ip6stat.ip6s_badscope++; 197 goto bad; 198 } 199 200 /* 201 * Swap the IPv6 destination address and nextaddr. Forward the packet. 202 */ 203 tmpaddr = *nextaddr; 204 *nextaddr = ip6->ip6_dst; 205 in6_clearscope(nextaddr); /* XXX */ 206 ip6->ip6_dst = tmpaddr; 207 208 #ifdef COMPAT_RFC1883 209 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 210 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 211 else 212 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 213 #else 214 ip6_forward(m, 1); 215 #endif 216 217 return (-1); /* m would be freed in ip6_forward() */ 218 219 bad: 220 m_freem(m); 221 return (-1); 222 } 223 #endif 224