1 /* $KAME: rtsol.c,v 1.12 2001/11/12 11:47:11 jinmei Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $FreeBSD: src/usr.sbin/rtsold/rtsol.c,v 1.1.2.4 2002/04/24 10:22:30 suz Exp $ 32 * $DragonFly: src/usr.sbin/rtsold/rtsol.c,v 1.2 2003/06/17 04:30:03 dillon Exp $ 33 */ 34 35 #include <sys/param.h> 36 #include <sys/socket.h> 37 #include <sys/uio.h> 38 #include <sys/time.h> 39 #include <sys/queue.h> 40 41 #include <net/if.h> 42 #include <net/route.h> 43 #include <net/if_dl.h> 44 45 #include <netinet/in.h> 46 #include <netinet/ip6.h> 47 #include <netinet6/ip6_var.h> 48 #include <netinet/icmp6.h> 49 50 #include <arpa/inet.h> 51 52 #include <time.h> 53 #include <unistd.h> 54 #include <stdio.h> 55 #include <err.h> 56 #include <errno.h> 57 #include <string.h> 58 #include <stdlib.h> 59 #include <syslog.h> 60 #include "rtsold.h" 61 62 #define ALLROUTER "ff02::2" 63 64 static struct msghdr rcvmhdr; 65 static struct msghdr sndmhdr; 66 static struct iovec rcviov[2]; 67 static struct iovec sndiov[2]; 68 static struct sockaddr_in6 from; 69 70 int rssock; 71 72 static struct sockaddr_in6 sin6_allrouters = {sizeof(sin6_allrouters), AF_INET6}; 73 74 int 75 sockopen() 76 { 77 int on; 78 struct icmp6_filter filt; 79 static u_char answer[1500]; 80 int rcvcmsglen, sndcmsglen; 81 static u_char *rcvcmsgbuf = NULL, *sndcmsgbuf = NULL; 82 83 sndcmsglen = rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) + 84 CMSG_SPACE(sizeof(int)); 85 if (rcvcmsgbuf == NULL && (rcvcmsgbuf = malloc(rcvcmsglen)) == NULL) { 86 warnmsg(LOG_ERR, __FUNCTION__, 87 "malloc for receive msghdr failed"); 88 return(-1); 89 } 90 if (sndcmsgbuf == NULL && (sndcmsgbuf = malloc(sndcmsglen)) == NULL) { 91 warnmsg(LOG_ERR, __FUNCTION__, 92 "malloc for send msghdr failed"); 93 return(-1); 94 } 95 memset(&sin6_allrouters, 0, sizeof(struct sockaddr_in6)); 96 sin6_allrouters.sin6_family = AF_INET6; 97 sin6_allrouters.sin6_len = sizeof(sin6_allrouters); 98 if (inet_pton(AF_INET6, ALLROUTER, 99 &sin6_allrouters.sin6_addr.s6_addr) != 1) { 100 warnmsg(LOG_ERR, __FUNCTION__, "inet_pton failed for %s", 101 ALLROUTER); 102 return(-1); 103 } 104 105 if ((rssock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) { 106 warnmsg(LOG_ERR, __FUNCTION__, "socket: %s", strerror(errno)); 107 return(-1); 108 } 109 110 /* specify to tell receiving interface */ 111 on = 1; 112 #ifdef IPV6_RECVPKTINFO 113 if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on, 114 sizeof(on)) < 0) { 115 warnmsg(LOG_ERR, __FUNCTION__, "IPV6_RECVPKTINFO: %s", 116 strerror(errno)); 117 exit(1); 118 } 119 #else /* old adv. API */ 120 if (setsockopt(rssock, IPPROTO_IPV6, IPV6_PKTINFO, &on, 121 sizeof(on)) < 0) { 122 warnmsg(LOG_ERR, __FUNCTION__, "IPV6_PKTINFO: %s", 123 strerror(errno)); 124 exit(1); 125 } 126 #endif 127 128 on = 1; 129 /* specify to tell value of hoplimit field of received IP6 hdr */ 130 #ifdef IPV6_RECVHOPLIMIT 131 if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on, 132 sizeof(on)) < 0) { 133 warnmsg(LOG_ERR, __FUNCTION__, "IPV6_RECVHOPLIMIT: %s", 134 strerror(errno)); 135 exit(1); 136 } 137 #else /* old adv. API */ 138 if (setsockopt(rssock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on, 139 sizeof(on)) < 0) { 140 warnmsg(LOG_ERR, __FUNCTION__, "IPV6_HOPLIMIT: %s", 141 strerror(errno)); 142 exit(1); 143 } 144 #endif 145 146 /* specfiy to accept only router advertisements on the socket */ 147 ICMP6_FILTER_SETBLOCKALL(&filt); 148 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt); 149 if (setsockopt(rssock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt, 150 sizeof(filt)) == -1) { 151 warnmsg(LOG_ERR, __FUNCTION__, "setsockopt(ICMP6_FILTER): %s", 152 strerror(errno)); 153 return(-1); 154 } 155 156 /* initialize msghdr for receiving packets */ 157 rcviov[0].iov_base = (caddr_t)answer; 158 rcviov[0].iov_len = sizeof(answer); 159 rcvmhdr.msg_name = (caddr_t)&from; 160 rcvmhdr.msg_namelen = sizeof(from); 161 rcvmhdr.msg_iov = rcviov; 162 rcvmhdr.msg_iovlen = 1; 163 rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf; 164 rcvmhdr.msg_controllen = rcvcmsglen; 165 166 /* initialize msghdr for sending packets */ 167 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6); 168 sndmhdr.msg_iov = sndiov; 169 sndmhdr.msg_iovlen = 1; 170 sndmhdr.msg_control = (caddr_t)sndcmsgbuf; 171 sndmhdr.msg_controllen = sndcmsglen; 172 173 return(rssock); 174 } 175 176 void 177 sendpacket(struct ifinfo *ifinfo) 178 { 179 int i; 180 struct cmsghdr *cm; 181 struct in6_pktinfo *pi; 182 183 sndmhdr.msg_name = (caddr_t)&sin6_allrouters; 184 sndmhdr.msg_iov[0].iov_base = (caddr_t)ifinfo->rs_data; 185 sndmhdr.msg_iov[0].iov_len = ifinfo->rs_datalen; 186 187 cm = CMSG_FIRSTHDR(&sndmhdr); 188 /* specify the outgoing interface */ 189 cm->cmsg_level = IPPROTO_IPV6; 190 cm->cmsg_type = IPV6_PKTINFO; 191 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); 192 pi = (struct in6_pktinfo *)CMSG_DATA(cm); 193 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/ 194 pi->ipi6_ifindex = ifinfo->sdl->sdl_index; 195 196 /* specify the hop limit of the packet */ 197 { 198 int hoplimit = 255; 199 200 cm = CMSG_NXTHDR(&sndmhdr, cm); 201 cm->cmsg_level = IPPROTO_IPV6; 202 cm->cmsg_type = IPV6_HOPLIMIT; 203 cm->cmsg_len = CMSG_LEN(sizeof(int)); 204 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int)); 205 } 206 207 warnmsg(LOG_DEBUG, 208 __FUNCTION__, "send RS on %s, whose state is %d", 209 ifinfo->ifname, ifinfo->state); 210 211 i = sendmsg(rssock, &sndmhdr, 0); 212 213 if (i < 0 || i != ifinfo->rs_datalen) { 214 /* 215 * ENETDOWN is not so serious, especially when using several 216 * network cards on a mobile node. We ignore it. 217 */ 218 if (errno != ENETDOWN || dflag > 0) 219 warnmsg(LOG_ERR, __FUNCTION__, "sendmsg on %s: %s", 220 ifinfo->ifname, strerror(errno)); 221 } 222 223 /* update counter */ 224 ifinfo->probes++; 225 } 226 227 void 228 rtsol_input(int s) 229 { 230 int i; 231 int *hlimp = NULL; 232 struct icmp6_hdr *icp; 233 int ifindex = 0; 234 struct cmsghdr *cm; 235 struct in6_pktinfo *pi = NULL; 236 struct ifinfo *ifi = NULL; 237 u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; 238 239 /* get message */ 240 if ((i = recvmsg(s, &rcvmhdr, 0)) < 0) { 241 warnmsg(LOG_ERR, __FUNCTION__, "recvmsg: %s", strerror(errno)); 242 return; 243 } 244 245 /* extract optional information via Advanced API */ 246 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr); 247 cm; 248 cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) { 249 if (cm->cmsg_level == IPPROTO_IPV6 && 250 cm->cmsg_type == IPV6_PKTINFO && 251 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) { 252 pi = (struct in6_pktinfo *)(CMSG_DATA(cm)); 253 ifindex = pi->ipi6_ifindex; 254 } 255 if (cm->cmsg_level == IPPROTO_IPV6 && 256 cm->cmsg_type == IPV6_HOPLIMIT && 257 cm->cmsg_len == CMSG_LEN(sizeof(int))) 258 hlimp = (int *)CMSG_DATA(cm); 259 } 260 261 if (ifindex == 0) { 262 warnmsg(LOG_ERR, 263 __FUNCTION__, "failed to get receiving interface"); 264 return; 265 } 266 if (hlimp == NULL) { 267 warnmsg(LOG_ERR, 268 __FUNCTION__, "failed to get receiving hop limit"); 269 return; 270 } 271 272 if (i < sizeof(struct nd_router_advert)) { 273 warnmsg(LOG_ERR, 274 __FUNCTION__, "packet size(%d) is too short", i); 275 return; 276 } 277 278 icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base; 279 280 if (icp->icmp6_type != ND_ROUTER_ADVERT) { 281 warnmsg(LOG_ERR, __FUNCTION__, 282 "invalid icmp type(%d) from %s on %s", icp->icmp6_type, 283 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 284 INET6_ADDRSTRLEN), 285 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 286 return; 287 } 288 289 if (icp->icmp6_code != 0) { 290 warnmsg(LOG_ERR, __FUNCTION__, 291 "invalid icmp code(%d) from %s on %s", icp->icmp6_code, 292 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 293 INET6_ADDRSTRLEN), 294 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 295 return; 296 } 297 298 if (*hlimp != 255) { 299 warnmsg(LOG_NOTICE, __FUNCTION__, 300 "invalid RA with hop limit(%d) from %s on %s", 301 *hlimp, 302 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 303 INET6_ADDRSTRLEN), 304 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 305 return; 306 } 307 308 if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) { 309 warnmsg(LOG_NOTICE, __FUNCTION__, 310 "invalid RA with non link-local source from %s on %s", 311 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 312 INET6_ADDRSTRLEN), 313 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 314 return; 315 } 316 317 /* xxx: more validation? */ 318 319 if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) { 320 warnmsg(LOG_NOTICE, __FUNCTION__, 321 "received RA from %s on an unexpeced IF(%s)", 322 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 323 INET6_ADDRSTRLEN), 324 if_indextoname(pi->ipi6_ifindex, ifnamebuf)); 325 return; 326 } 327 328 warnmsg(LOG_DEBUG, __FUNCTION__, 329 "received RA from %s on %s, state is %d", 330 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, 331 INET6_ADDRSTRLEN), 332 ifi->ifname, ifi->state); 333 334 ifi->racnt++; 335 336 switch(ifi->state) { 337 case IFS_IDLE: /* should be ignored */ 338 case IFS_DELAY: /* right? */ 339 break; 340 case IFS_PROBE: 341 ifi->state = IFS_IDLE; 342 ifi->probes = 0; 343 rtsol_timer_update(ifi); 344 break; 345 } 346 } 347