usr.sbin/rtsold/rtsol.c

   1 /*      $NetBSD: rtsol.c,v 1.14 2007/09/06 09:26:21 jnemeth Exp $       */
   2 /*      $KAME: rtsol.c,v 1.15 2002/05/31 10:10:03 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/socket.h>
  35 #include <sys/uio.h>
  36 #include <sys/time.h>
  37 #include <sys/queue.h>
  38
  39 #include <net/if.h>
  40 #include <net/route.h>
  41 #include <net/if_dl.h>
  42
  43 #include <netinet/in.h>
  44 #include <netinet/ip6.h>
  45 #include <netinet6/ip6_var.h>
  46 #include <netinet/icmp6.h>
  47
  48 #include <arpa/inet.h>
  49
  50 #include <time.h>
  51 #include <unistd.h>
  52 #include <stdio.h>
  53 #include <err.h>
  54 #include <errno.h>
  55 #include <string.h>
  56 #include <stdlib.h>
  57 #include <syslog.h>
  58 #include "rtsold.h"
  59
  60 #define ALLROUTER "ff02::2"
  61
  62 static struct msghdr rcvmhdr;
  63 static struct msghdr sndmhdr;
  64 static struct iovec rcviov[2];
  65 static struct iovec sndiov[2];
  66 static struct sockaddr_in6 from;
  67
  68 int rssock;
  69
  70 static struct sockaddr_in6 sin6_allrouters = {
  71         .sin6_len = sizeof(sin6_allrouters),
  72         .sin6_family = AF_INET6
  73 };
  74
  75 int
  76 sockopen(void)
  77 {
  78         static u_char *rcvcmsgbuf = NULL, *sndcmsgbuf = NULL;
  79         int rcvcmsglen, sndcmsglen, on;
  80         static u_char answer[1500];
  81         struct icmp6_filter filt;
  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, __func__,
  87                     "malloc for receive msghdr failed");
  88                 return(-1);
  89         }
  90         if (sndcmsgbuf == NULL && (sndcmsgbuf = malloc(sndcmsglen)) == NULL) {
  91                 warnmsg(LOG_ERR, __func__,
  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, __func__, "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, __func__, "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, __func__, "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, __func__, "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, __func__, "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, __func__, "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, __func__, "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         struct in6_pktinfo *pi;
 180         struct cmsghdr *cm;
 181         int hoplimit = 255;
 182         ssize_t i;
 183         struct sockaddr_in6 dst;
 184
 185         dst = sin6_allrouters;
 186         dst.sin6_scope_id = ifinfo->linkid;
 187
 188         sndmhdr.msg_name = (caddr_t)&dst;
 189         sndmhdr.msg_iov[0].iov_base = (caddr_t)ifinfo->rs_data;
 190         sndmhdr.msg_iov[0].iov_len = ifinfo->rs_datalen;
 191
 192         cm = CMSG_FIRSTHDR(&sndmhdr);
 193         /* specify the outgoing interface */
 194         cm->cmsg_level = IPPROTO_IPV6;
 195         cm->cmsg_type = IPV6_PKTINFO;
 196         cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
 197         pi = (struct in6_pktinfo *)CMSG_DATA(cm);
 198         memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
 199         pi->ipi6_ifindex = ifinfo->sdl->sdl_index;
 200
 201         /* specify the hop limit of the packet */
 202         cm = CMSG_NXTHDR(&sndmhdr, cm);
 203         cm->cmsg_level = IPPROTO_IPV6;
 204         cm->cmsg_type = IPV6_HOPLIMIT;
 205         cm->cmsg_len = CMSG_LEN(sizeof(int));
 206         memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
 207
 208         warnmsg(LOG_DEBUG, __func__,
 209             "send RS on %s, whose state is %d",
 210             ifinfo->ifname, ifinfo->state);
 211
 212         i = sendmsg(rssock, &sndmhdr, 0);
 213
 214         if (i < 0 || (size_t)i != ifinfo->rs_datalen) {
 215                 /*
 216                  * ENETDOWN is not so serious, especially when using several
 217                  * network cards on a mobile node. We ignore it.
 218                  */
 219                 if (errno != ENETDOWN || dflag > 0)
 220                         warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s",
 221                             ifinfo->ifname, strerror(errno));
 222         }
 223
 224         /* update counter */
 225         ifinfo->probes++;
 226 }
 227
 228 void
 229 rtsol_input(int s)
 230 {
 231         char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 232         int ifindex = 0, *hlimp = NULL;
 233         ssize_t i;
 234         struct in6_pktinfo *pi = NULL;
 235         struct ifinfo *ifi = NULL;
 236         struct icmp6_hdr *icp;
 237         struct cmsghdr *cm;
 238
 239         /* get message */
 240         if ((i = recvmsg(s, &rcvmhdr, 0)) < 0) {
 241                 warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno));
 242                 return;
 243         }
 244
 245         /* extract optional information via Advanced API */
 246         for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr); cm;
 247             cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
 248                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 249                     cm->cmsg_type == IPV6_PKTINFO &&
 250                     cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
 251                         pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
 252                         ifindex = pi->ipi6_ifindex;
 253                 }
 254                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 255                     cm->cmsg_type == IPV6_HOPLIMIT &&
 256                     cm->cmsg_len == CMSG_LEN(sizeof(int)))
 257                         hlimp = (int *)CMSG_DATA(cm);
 258         }
 259
 260         if (ifindex == 0) {
 261                 warnmsg(LOG_ERR, __func__,
 262                     "failed to get receiving interface");
 263                 return;
 264         }
 265         if (hlimp == NULL) {
 266                 warnmsg(LOG_ERR, __func__,
 267                     "failed to get receiving hop limit");
 268                 return;
 269         }
 270
 271         if (i < (ssize_t)sizeof(struct nd_router_advert)) {
 272                 warnmsg(LOG_ERR, __func__,
 273                     "packet size(%zd) is too short", i);
 274                 return;
 275         }
 276
 277         icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 278
 279         if (icp->icmp6_type != ND_ROUTER_ADVERT) {
 280                 warnmsg(LOG_ERR, __func__,
 281                     "invalid icmp type(%d) from %s on %s", icp->icmp6_type,
 282                     inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 283                     INET6_ADDRSTRLEN),
 284                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 285                 return;
 286         }
 287
 288         if (icp->icmp6_code != 0) {
 289                 warnmsg(LOG_ERR, __func__,
 290                     "invalid icmp code(%d) from %s on %s", icp->icmp6_code,
 291                     inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 292                     INET6_ADDRSTRLEN),
 293                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 294                 return;
 295         }
 296
 297         if (*hlimp != 255) {
 298                 warnmsg(LOG_NOTICE, __func__,
 299                     "invalid RA with hop limit(%d) from %s on %s",
 300                     *hlimp,
 301                     inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 302                     INET6_ADDRSTRLEN),
 303                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 304                 return;
 305         }
 306
 307         if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) {
 308                 warnmsg(LOG_NOTICE, __func__,
 309                     "invalid RA with non link-local source from %s on %s",
 310                     inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 311                     INET6_ADDRSTRLEN),
 312                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 313                 return;
 314         }
 315
 316         /* xxx: more validation? */
 317
 318         if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) {
 319                 warnmsg(LOG_NOTICE, __func__,
 320                     "received RA from %s on an unexpected IF(%s)",
 321                     inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 322                     INET6_ADDRSTRLEN),
 323                     if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 324                 return;
 325         }
 326
 327         warnmsg(LOG_DEBUG, __func__,
 328             "received RA from %s on %s, state is %d",
 329             inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, INET6_ADDRSTRLEN),
 330             ifi->ifname, ifi->state);
 331
 332         ifi->racnt++;
 333
 334         switch (ifi->state) {
 335         case IFS_IDLE:          /* should be ignored */
 336         case IFS_DELAY:         /* right? */
 337                 break;
 338         case IFS_PROBE:
 339                 ifi->state = IFS_IDLE;
 340                 ifi->probes = 0;
 341                 rtsol_timer_update(ifi);
 342                 break;
 343         }
 344 }