1 /* $NetBSD: route6.c,v 1.15 2006/10/12 01:32:39 christos 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 1.15 2006/10/12 01:32:39 christos 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(struct mbuf **mp, int *offp, int proto __unused) 57 { 58 struct ip6_hdr *ip6; 59 struct mbuf *m = *mp; 60 struct ip6_rthdr *rh; 61 int off = *offp, rhlen; 62 63 ip6 = mtod(m, struct ip6_hdr *); 64 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 65 if (rh == NULL) { 66 ip6stat.ip6s_tooshort++; 67 return IPPROTO_DONE; 68 } 69 70 switch (rh->ip6r_type) { 71 case IPV6_RTHDR_TYPE_0: 72 rhlen = (rh->ip6r_len + 1) << 3; 73 /* 74 * note on option length: 75 * maximum rhlen: 2048 76 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 77 * so, here we are assuming that m_pulldown can handle 78 * rhlen == 2048 case. this may not be a good thing to 79 * assume - we may want to avoid pulling it up altogether. 80 */ 81 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 82 if (rh == NULL) { 83 ip6stat.ip6s_tooshort++; 84 return IPPROTO_DONE; 85 } 86 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 87 return (IPPROTO_DONE); 88 break; 89 default: 90 /* unknown routing type */ 91 if (rh->ip6r_segleft == 0) { 92 rhlen = (rh->ip6r_len + 1) << 3; 93 break; /* Final dst. Just ignore the header. */ 94 } 95 ip6stat.ip6s_badoptions++; 96 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 97 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 98 return (IPPROTO_DONE); 99 } 100 101 *offp += rhlen; 102 return (rh->ip6r_nxt); 103 } 104 105 /* 106 * Type0 routing header processing 107 * 108 * RFC2292 backward compatibility warning: no support for strict/loose bitmap, 109 * as it was dropped between RFC1883 and RFC2460. 110 */ 111 static int 112 ip6_rthdr0(m, ip6, rh0) 113 struct mbuf *m; 114 struct ip6_hdr *ip6; 115 struct ip6_rthdr0 *rh0; 116 { 117 int addrs, index; 118 struct in6_addr *nextaddr, tmpaddr; 119 struct in6_ifaddr *ifa; 120 121 if (rh0->ip6r0_segleft == 0) 122 return (0); 123 124 if (rh0->ip6r0_len % 2 125 #ifdef COMPAT_RFC1883 126 || rh0->ip6r0_len > 46 127 #endif 128 ) { 129 /* 130 * Type 0 routing header can't contain more than 23 addresses. 131 * RFC 2462: this limitation was removed since strict/loose 132 * bitmap field was deleted. 133 */ 134 ip6stat.ip6s_badoptions++; 135 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 136 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 137 return (-1); 138 } 139 140 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 141 ip6stat.ip6s_badoptions++; 142 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 143 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 144 return (-1); 145 } 146 147 index = addrs - rh0->ip6r0_segleft; 148 rh0->ip6r0_segleft--; 149 nextaddr = ((struct in6_addr *)(rh0 + 1)) + index; 150 151 /* 152 * reject invalid addresses. be proactive about malicious use of 153 * IPv4 mapped/compat address. 154 * XXX need more checks? 155 */ 156 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 157 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 158 IN6_IS_ADDR_V4MAPPED(nextaddr) || 159 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 160 ip6stat.ip6s_badoptions++; 161 goto bad; 162 } 163 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 164 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 165 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 166 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 167 ip6stat.ip6s_badoptions++; 168 goto bad; 169 } 170 171 /* 172 * Determine the scope zone of the next hop, based on the interface 173 * of the current hop. [RFC4007, Section 9] 174 * Then disambiguate the scope zone for the next hop (if necessary). 175 */ 176 if ((ifa = ip6_getdstifaddr(m)) == NULL) 177 goto bad; 178 if (in6_setscope(nextaddr, ifa->ia_ifp, NULL) != 0) { 179 ip6stat.ip6s_badscope++; 180 goto bad; 181 } 182 183 /* 184 * Swap the IPv6 destination address and nextaddr. Forward the packet. 185 */ 186 tmpaddr = *nextaddr; 187 *nextaddr = ip6->ip6_dst; 188 in6_clearscope(nextaddr); /* XXX */ 189 ip6->ip6_dst = tmpaddr; 190 191 #ifdef COMPAT_RFC1883 192 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 193 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 194 else 195 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 196 #else 197 ip6_forward(m, 1); 198 #endif 199 200 return (-1); /* m would be freed in ip6_forward() */ 201 202 bad: 203 m_freem(m); 204 return (-1); 205 } 206