1 /* $OpenBSD: route6.c,v 1.5 2001/02/16 08:48:07 itojun 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/param.h> 34 #include <sys/mbuf.h> 35 #include <sys/socket.h> 36 #include <sys/systm.h> 37 38 #include <net/if.h> 39 40 #include <netinet/in.h> 41 #include <netinet6/in6_var.h> 42 #include <netinet/ip6.h> 43 #include <netinet6/ip6_var.h> 44 45 #include <netinet/icmp6.h> 46 47 static int ip6_rthdr0 __P((struct mbuf *, struct ip6_hdr *, 48 struct ip6_rthdr0 *)); 49 50 int 51 route6_input(mp, offp, proto) 52 struct mbuf **mp; 53 int *offp, proto; /* proto is unused */ 54 { 55 struct ip6_hdr *ip6; 56 struct mbuf *m = *mp; 57 struct ip6_rthdr *rh; 58 int off = *offp, rhlen; 59 60 #ifndef PULLDOWN_TEST 61 IP6_EXTHDR_CHECK(m, off, sizeof(*rh), IPPROTO_DONE); 62 ip6 = mtod(m, struct ip6_hdr *); 63 rh = (struct ip6_rthdr *)((caddr_t)ip6 + off); 64 #else 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 #endif 72 73 switch (rh->ip6r_type) { 74 case IPV6_RTHDR_TYPE_0: 75 rhlen = (rh->ip6r_len + 1) << 3; 76 #ifndef PULLDOWN_TEST 77 /* 78 * note on option length: 79 * due to IP6_EXTHDR_CHECK assumption, we cannot handle 80 * very big routing header (max rhlen == 2048). 81 */ 82 IP6_EXTHDR_CHECK(m, off, rhlen, IPPROTO_DONE); 83 #else 84 /* 85 * note on option length: 86 * maximum rhlen: 2048 87 * max mbuf m_pulldown can handle: MCLBYTES == usually 2048 88 * so, here we are assuming that m_pulldown can handle 89 * rhlen == 2048 case. this may not be a good thing to 90 * assume - we may want to avoid pulling it up altogether. 91 */ 92 IP6_EXTHDR_GET(rh, struct ip6_rthdr *, m, off, rhlen); 93 if (rh == NULL) { 94 ip6stat.ip6s_tooshort++; 95 return IPPROTO_DONE; 96 } 97 #endif 98 if (ip6_rthdr0(m, ip6, (struct ip6_rthdr0 *)rh)) 99 return(IPPROTO_DONE); 100 break; 101 default: 102 /* unknown routing type */ 103 if (rh->ip6r_segleft == 0) { 104 rhlen = (rh->ip6r_len + 1) << 3; 105 break; /* Final dst. Just ignore the header. */ 106 } 107 ip6stat.ip6s_badoptions++; 108 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 109 (caddr_t)&rh->ip6r_type - (caddr_t)ip6); 110 return(IPPROTO_DONE); 111 } 112 113 *offp += rhlen; 114 return(rh->ip6r_nxt); 115 } 116 117 /* 118 * Type0 routing header processing 119 */ 120 static int 121 ip6_rthdr0(m, ip6, rh0) 122 struct mbuf *m; 123 struct ip6_hdr *ip6; 124 struct ip6_rthdr0 *rh0; 125 { 126 int addrs, index; 127 struct in6_addr *nextaddr, tmpaddr; 128 129 if (rh0->ip6r0_segleft == 0) 130 return(0); 131 132 if (rh0->ip6r0_len % 2 133 #ifdef COMPAT_RFC1883 134 || rh0->ip6r0_len > 46 135 #endif 136 ) { 137 /* 138 * Type 0 routing header can't contain more than 23 addresses. 139 * RFC 2462: this limitation was removed since stict/loose 140 * bitmap field was deleted. 141 */ 142 ip6stat.ip6s_badoptions++; 143 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 144 (caddr_t)&rh0->ip6r0_len - (caddr_t)ip6); 145 return(-1); 146 } 147 148 if ((addrs = rh0->ip6r0_len / 2) < rh0->ip6r0_segleft) { 149 ip6stat.ip6s_badoptions++; 150 icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 151 (caddr_t)&rh0->ip6r0_segleft - (caddr_t)ip6); 152 return(-1); 153 } 154 155 index = addrs - rh0->ip6r0_segleft; 156 rh0->ip6r0_segleft--; 157 nextaddr = rh0->ip6r0_addr + index; 158 159 /* 160 * reject invalid addresses. be proactive about malicious use of 161 * IPv4 mapped/compat address. 162 * XXX need more checks? 163 */ 164 if (IN6_IS_ADDR_MULTICAST(nextaddr) || 165 IN6_IS_ADDR_UNSPECIFIED(nextaddr) || 166 IN6_IS_ADDR_V4MAPPED(nextaddr) || 167 IN6_IS_ADDR_V4COMPAT(nextaddr)) { 168 ip6stat.ip6s_badoptions++; 169 m_freem(m); 170 return(-1); 171 } 172 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || 173 IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst) || 174 IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst) || 175 IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { 176 ip6stat.ip6s_badoptions++; 177 m_freem(m); 178 return(-1); 179 } 180 181 /* 182 * Swap the IPv6 destination address and nextaddr. Forward the packet. 183 */ 184 tmpaddr = *nextaddr; 185 *nextaddr = ip6->ip6_dst; 186 if (IN6_IS_ADDR_LINKLOCAL(nextaddr)) 187 nextaddr->s6_addr16[1] = 0; 188 ip6->ip6_dst = tmpaddr; 189 if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) 190 ip6->ip6_dst.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index); 191 192 #ifdef COMPAT_RFC1883 193 if (rh0->ip6r0_slmap[index / 8] & (1 << (7 - (index % 8)))) 194 ip6_forward(m, IPV6_SRCRT_NEIGHBOR); 195 else 196 ip6_forward(m, IPV6_SRCRT_NOTNEIGHBOR); 197 #else 198 ip6_forward(m, 1); 199 #endif 200 201 return(-1); /* m would be freed in ip6_forward() */ 202 } 203