1 /* $NetBSD: route6.c,v 1.14 2006/01/21 00:15:37 rpaulo 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 1.14 2006/01/21 00:15:37 rpaulo 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 static int ip6_rthdr0 __P((struct mbuf *, struct ip6_hdr *, 53 struct ip6_rthdr0 *)); 54 55 int 56 route6_input(mp, offp, proto) 57 struct mbuf **mp; 58 int *offp, 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 ip6 = mtod(m, struct ip6_hdr *); 66 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 67 if (rh == NULL) { 68 ip6stat.ip6s_tooshort++; 69 return IPPROTO_DONE; 70 } 71 72 switch (rh->ip6r_type) { 73 case IPV6_RTHDR_TYPE_0: 74 rhlen = (rh->ip6r_len + 1) << 3; 75 /* 76 * note on option length: 77 * maximum rhlen: 2048 78 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 79 * so, here we are assuming that m_pulldown can handle 80 * rhlen == 2048 case. this may not be a good thing to 81 * assume - we may want to avoid pulling it up altogether. 82 */ 83 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 84 if (rh == NULL) { 85 ip6stat.ip6s_tooshort++; 86 return IPPROTO_DONE; 87 } 88 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 89 return (IPPROTO_DONE); 90 break; 91 default: 92 /* unknown routing type */ 93 if (rh->ip6r_segleft == 0) { 94 rhlen = (rh->ip6r_len + 1) << 3; 95 break; /* Final dst. Just ignore the header. */ 96 } 97 ip6stat.ip6s_badoptions++; 98 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 99 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 100 return (IPPROTO_DONE); 101 } 102 103 *offp += rhlen; 104 return (rh->ip6r_nxt); 105 } 106 107 /* 108 * Type0 routing header processing 109 * 110 * RFC2292 backward compatibility warning: no support for strict/loose bitmap, 111 * as it was dropped between RFC1883 and RFC2460. 112 */ 113 static int 114 ip6_rthdr0(m, ip6, rh0) 115 struct mbuf *m; 116 struct ip6_hdr *ip6; 117 struct ip6_rthdr0 *rh0; 118 { 119 int addrs, index; 120 struct in6_addr *nextaddr, tmpaddr; 121 struct in6_ifaddr *ifa; 122 123 if (rh0->ip6r0_segleft == 0) 124 return (0); 125 126 if (rh0->ip6r0_len % 2 127 #ifdef COMPAT_RFC1883 128 || rh0->ip6r0_len > 46 129 #endif 130 ) { 131 /* 132 * Type 0 routing header can't contain more than 23 addresses. 133 * RFC 2462: this limitation was removed since strict/loose 134 * bitmap field was deleted. 135 */ 136 ip6stat.ip6s_badoptions++; 137 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 138 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 139 return (-1); 140 } 141 142 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 143 ip6stat.ip6s_badoptions++; 144 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 145 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 146 return (-1); 147 } 148 149 index = addrs - rh0->ip6r0_segleft; 150 rh0->ip6r0_segleft--; 151 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index; 152 153 /* 154 * reject invalid addresses. be proactive about malicious use of 155 * IPv4 mapped/compat address. 156 * XXX need more checks? 157 */ 158 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 159 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 160 IN6_IS_ADDR_V4MAPPED(nextaddr) || 161 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 162 ip6stat.ip6s_badoptions++; 163 goto bad; 164 } 165 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 166 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 167 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 168 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 169 ip6stat.ip6s_badoptions++; 170 goto bad; 171 } 172 173 /* 174 * Determine the scope zone of the next hop, based on the interface 175 * of the current hop. [RFC4007, Section 9] 176 * Then disambiguate the scope zone for the next hop (if necessary). 177 */ 178 if ((ifa = ip6_getdstifaddr(m)) == NULL) 179 goto bad; 180 if (in6_setscope(nextaddr, ifa->ia_ifp, NULL) != 0) { 181 ip6stat.ip6s_badscope++; 182 goto bad; 183 } 184 185 /* 186 * Swap the IPv6 destination address and nextaddr. Forward the packet. 187 */ 188 tmpaddr = *nextaddr; 189 *nextaddr = ip6->ip6_dst; 190 in6_clearscope(nextaddr); /* XXX */ 191 ip6->ip6_dst = tmpaddr; 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 bad: 205 m_freem(m); 206 return (-1); 207 } 208