1 /* $NetBSD: route6.c,v 1.23 2008/04/15 03:57:04 thorpej 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 1.23 2008/04/15 03:57:04 thorpej 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/ip6_private.h> 49 #include <netinet6/scope6_var.h> 50 51 #include <netinet/icmp6.h> 52 53 #if 0 54 static int ip6_rthdr0(struct mbuf *, struct ip6_hdr *, struct ip6_rthdr0 *); 55 #endif 56 57 int 58 route6_input(struct mbuf **mp, int *offp, int proto) 59 { 60 struct ip6_hdr *ip6; 61 struct mbuf *m = *mp; 62 struct ip6_rthdr *rh; 63 int off = *offp, rhlen; 64 65 ip6 = mtod(m, struct ip6_hdr *); 66 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 67 if (rh == NULL) { 68 IP6_STATINC(IP6_STAT_TOOSHORT); 69 return IPPROTO_DONE; 70 } 71 72 switch (rh->ip6r_type) { 73 #if 0 74 /* 75 * See http://www.secdev.org/conf/IPv6_RH_security-csw07.pdf 76 * for why IPV6_RTHDR_TYPE_0 is banned here. 77 * 78 * We return ICMPv6 parameter problem so that innocent people 79 * (not an attacker) would notice about the use of IPV6_RTHDR_TYPE_0. 80 * Since there's no amplification, and ICMPv6 error will be rate- 81 * controlled, it shouldn't cause any problem. 82 * If you are concerned about this, you may want to use the following 83 * code fragment: 84 * 85 * case IPV6_RTHDR_TYPE_0: 86 * m_freem(m); 87 * return (IPPROTO_DONE); 88 */ 89 case IPV6_RTHDR_TYPE_0: 90 rhlen = (rh->ip6r_len + 1) << 3; 91 /* 92 * note on option length: 93 * maximum rhlen: 2048 94 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 95 * so, here we are assuming that m_pulldown can handle 96 * rhlen == 2048 case. this may not be a good thing to 97 * assume - we may want to avoid pulling it up altogether. 98 */ 99 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 100 if (rh == NULL) { 101 IP6_STATINC(IP6_STAT_TOOSHORT); 102 return IPPROTO_DONE; 103 } 104 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 105 return (IPPROTO_DONE); 106 break; 107 #endif 108 default: 109 /* unknown routing type */ 110 if (rh->ip6r_segleft == 0) { 111 rhlen = (rh->ip6r_len + 1) << 3; 112 break; /* Final dst. Just ignore the header. */ 113 } 114 IP6_STATINC(IP6_STAT_BADOPTIONS); 115 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 116 (char *)&rh->ip6r_type - (char *)ip6); 117 return (IPPROTO_DONE); 118 } 119 120 *offp += rhlen; 121 return (rh->ip6r_nxt); 122 } 123 124 #if 0 125 /* 126 * Type0 routing header processing 127 * 128 * RFC2292 backward compatibility warning: no support for strict/loose bitmap, 129 * as it was dropped between RFC1883 and RFC2460. 130 */ 131 static int 132 ip6_rthdr0(struct mbuf *m, struct ip6_hdr *ip6, 133 struct ip6_rthdr0 *rh0) 134 { 135 int addrs, index; 136 struct in6_addr *nextaddr, tmpaddr; 137 const struct ip6aux *ip6a; 138 139 if (rh0->ip6r0_segleft == 0) 140 return (0); 141 142 if (rh0->ip6r0_len % 2 143 #ifdef COMPAT_RFC1883 144 || rh0->ip6r0_len > 46 145 #endif 146 ) { 147 /* 148 * Type 0 routing header can't contain more than 23 addresses. 149 * RFC 2462: this limitation was removed since strict/loose 150 * bitmap field was deleted. 151 */ 152 IP6_STATINC(IP6_STAT_BADOPTIONS); 153 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 154 (char *)&rh0->ip6r0_len - (char *)ip6); 155 return (-1); 156 } 157 158 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 159 IP6_STATINC(IP6_STAT_BADOPTIONS); 160 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 161 (char *)&rh0->ip6r0_segleft - (char *)ip6); 162 return (-1); 163 } 164 165 index = addrs - rh0->ip6r0_segleft; 166 rh0->ip6r0_segleft--; 167 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index; 168 169 /* 170 * reject invalid addresses. be proactive about malicious use of 171 * IPv4 mapped/compat address. 172 * XXX need more checks? 173 */ 174 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 175 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 176 IN6_IS_ADDR_V4MAPPED(nextaddr) || 177 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 178 p6stat[IP6_STAT_BADOPTIONS]++; 179 goto bad; 180 } 181 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 182 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 183 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 184 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 185 IP6_STATINC(IP6_STAT_BADOPTIONS); 186 goto bad; 187 } 188 189 /* 190 * Determine the scope zone of the next hop, based on the interface 191 * of the current hop. [RFC4007, Section 9] 192 * Then disambiguate the scope zone for the next hop (if necessary). 193 */ 194 if ((ip6a = ip6_getdstifaddr(m)) == NULL) 195 goto bad; 196 if (in6_setzoneid(nextaddr, ip6a->ip6a_scope_id) != 0) { 197 IP6_STATINC(IP6_STAT_BADSCOPE); 198 goto bad; 199 } 200 201 /* 202 * Swap the IPv6 destination address and nextaddr. Forward the packet. 203 */ 204 tmpaddr = *nextaddr; 205 *nextaddr = ip6->ip6_dst; 206 in6_clearscope(nextaddr); /* XXX */ 207 ip6->ip6_dst = tmpaddr; 208 209 #ifdef COMPAT_RFC1883 210 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 211 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 212 else 213 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 214 #else 215 ip6_forward(m, 1); 216 #endif 217 218 return (-1); /* m would be freed in ip6_forward() */ 219 220 bad: 221 m_freem(m); 222 return (-1); 223 } 224 #endif 225