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 1.5 2004/09/14 21:00:01 joerg 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 static int ip6_rthdr0 (struct mbuf *, struct ip6_hdr *, 53 struct ip6_rthdr0 *); 54 55 int 56 route6_input(struct mbuf **mp, int *offp, int proto) /* proto is unused */ 57 { 58 struct ip6_hdr *ip6; 59 struct mbuf *m = *mp; 60 struct ip6_rthdr *rh; 61 int off = *offp, rhlen; 62 63 #ifndef PULLDOWN_TEST 64 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE); 65 ip6 = mtod(m, struct ip6_hdr *); 66 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off); 67 #else 68 ip6 = mtod(m, struct ip6_hdr *); 69 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, sizeof(*rh)); 70 if (rh == NULL) { 71 ip6stat.ip6s_tooshort++; 72 return IPPROTO_DONE; 73 } 74 #endif 75 76 switch (rh->ip6r_type) { 77 case IPV6_RTHDR_TYPE_0: 78 rhlen = (rh->ip6r_len + 1) << 3; 79 #ifndef PULLDOWN_TEST 80 /* 81 * note on option length: 82 * due to IP6_EXTHDR_CHECK assumption, we cannot handle 83 * very big routing header (max rhlen == 2048). 84 */ 85 IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE); 86 #else 87 /* 88 * note on option length: 89 * maximum rhlen: 2048 90 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 91 * so, here we are assuming that m_pulldown can handle 92 * rhlen == 2048 case. this may not be a good thing to 93 * assume - we may want to avoid pulling it up altogether. 94 */ 95 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 96 if (rh == NULL) { 97 ip6stat.ip6s_tooshort++; 98 return IPPROTO_DONE; 99 } 100 #endif 101 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 102 return(IPPROTO_DONE); 103 break; 104 default: 105 /* unknown routing type */ 106 if (rh->ip6r_segleft == 0) { 107 rhlen = (rh->ip6r_len + 1) << 3; 108 break; /* Final dst. Just ignore the header. */ 109 } 110 ip6stat.ip6s_badoptions++; 111 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 112 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 113 return(IPPROTO_DONE); 114 } 115 116 *offp += rhlen; 117 return(rh->ip6r_nxt); 118 } 119 120 /* 121 * Type0 routing header processing 122 * 123 * RFC2292 backward compatibility warning: no support for strict/loose bitmap, 124 * as it was dropped between RFC1883 and RFC2460. 125 */ 126 static int 127 ip6_rthdr0(struct mbuf *m, struct ip6_hdr *ip6, struct ip6_rthdr0 *rh0) 128 { 129 int addrs, index; 130 struct in6_addr *nextaddr, tmpaddr; 131 132 if (rh0->ip6r0_segleft == 0) 133 return(0); 134 135 if (rh0->ip6r0_len % 2 136 #ifdef COMPAT_RFC1883 137 || rh0->ip6r0_len > 46 138 #endif 139 ) { 140 /* 141 * Type 0 routing header can't contain more than 23 addresses. 142 * RFC 2462: this limitation was removed since strict/loose 143 * bitmap field was deleted. 144 */ 145 ip6stat.ip6s_badoptions++; 146 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 147 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 148 return(-1); 149 } 150 151 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 152 ip6stat.ip6s_badoptions++; 153 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 154 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 155 return(-1); 156 } 157 158 index = addrs - rh0->ip6r0_segleft; 159 rh0->ip6r0_segleft--; 160 /* note that ip6r0_addr does not exist in RFC2292bis */ 161 nextaddr = rh0->ip6r0_addr + index; 162 163 /* 164 * reject invalid addresses. be proactive about malicious use of 165 * IPv4 mapped/compat address. 166 * XXX need more checks? 167 */ 168 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 169 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 170 IN6_IS_ADDR_V4MAPPED(nextaddr) || 171 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 172 ip6stat.ip6s_badoptions++; 173 m_freem(m); 174 return(-1); 175 } 176 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 177 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 178 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 179 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 180 ip6stat.ip6s_badoptions++; 181 m_freem(m); 182 return(-1); 183 } 184 185 /* 186 * Swap the IPv6 destination address and nextaddr. Forward the packet. 187 */ 188 tmpaddr = *nextaddr; 189 *nextaddr = ip6->ip6_dst; 190 if (IN6_IS_ADDR_LINKLOCAL(nextaddr)) 191 nextaddr->s6_addr16[1] = 0; 192 ip6->ip6_dst = tmpaddr; 193 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) 194 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 195 196 #ifdef COMPAT_RFC1883 197 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 198 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 199 else 200 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 201 #else 202 ip6_forward(m, 1); 203 #endif 204 205 return(-1); /* m would be freed in ip6_forward() */ 206 } 207