usr.sbin/rtsold/rtsol.c

   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 1.5 2005/12/05 00:56:37 swildner 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 = {
  73         sizeof(sin6_allrouters),
  74         AF_INET6,
  75         0,
  76         0,
  77         IN6ADDR_ANY_INIT,
  78         0
  79 };
  80
  81 int
  82 sockopen(void)
  83 {
  84         int on;
  85         struct icmp6_filter filt;
  86         static u_char answer[1500];
  87         int rcvcmsglen, sndcmsglen;
  88         static u_char *rcvcmsgbuf = NULL, *sndcmsgbuf = NULL;
  89
  90         sndcmsglen = rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
  91                 CMSG_SPACE(sizeof(int));
  92         if (rcvcmsgbuf == NULL && (rcvcmsgbuf = malloc(rcvcmsglen)) == NULL) {
  93                 warnmsg(LOG_ERR, __func__,
  94                         "malloc for receive msghdr failed");
  95                 return(-1);
  96         }
  97         if (sndcmsgbuf == NULL && (sndcmsgbuf = malloc(sndcmsglen)) == NULL) {
  98                 warnmsg(LOG_ERR, __func__,
  99                         "malloc for send msghdr failed");
 100                 return(-1);
 101         }
 102         memset(&sin6_allrouters, 0, sizeof(struct sockaddr_in6));
 103         sin6_allrouters.sin6_family = AF_INET6;
 104         sin6_allrouters.sin6_len = sizeof(sin6_allrouters);
 105         if (inet_pton(AF_INET6, ALLROUTER,
 106                       &sin6_allrouters.sin6_addr.s6_addr) != 1) {
 107                 warnmsg(LOG_ERR, __func__, "inet_pton failed for %s",
 108                        ALLROUTER);
 109                 return(-1);
 110         }
 111
 112         if ((rssock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
 113                 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
 114                 return(-1);
 115         }
 116
 117         /* specify to tell receiving interface */
 118         on = 1;
 119 #ifdef IPV6_RECVPKTINFO
 120         if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
 121                        sizeof(on)) < 0) {
 122                 warnmsg(LOG_ERR, __func__, "IPV6_RECVPKTINFO: %s",
 123                        strerror(errno));
 124                 exit(1);
 125         }
 126 #else  /* old adv. API */
 127         if (setsockopt(rssock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
 128                        sizeof(on)) < 0) {
 129                 warnmsg(LOG_ERR, __func__, "IPV6_PKTINFO: %s",
 130                        strerror(errno));
 131                 exit(1);
 132         }
 133 #endif
 134
 135         on = 1;
 136         /* specify to tell value of hoplimit field of received IP6 hdr */
 137 #ifdef IPV6_RECVHOPLIMIT
 138         if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
 139                        sizeof(on)) < 0) {
 140                 warnmsg(LOG_ERR, __func__, "IPV6_RECVHOPLIMIT: %s",
 141                        strerror(errno));
 142                 exit(1);
 143         }
 144 #else  /* old adv. API */
 145         if (setsockopt(rssock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
 146                        sizeof(on)) < 0) {
 147                 warnmsg(LOG_ERR, __func__, "IPV6_HOPLIMIT: %s",
 148                        strerror(errno));
 149                 exit(1);
 150         }
 151 #endif
 152
 153         /* specfiy to accept only router advertisements on the socket */
 154         ICMP6_FILTER_SETBLOCKALL(&filt);
 155         ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
 156         if (setsockopt(rssock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
 157                        sizeof(filt)) == -1) {
 158                 warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s",
 159                        strerror(errno));
 160                 return(-1);
 161         }
 162
 163         /* initialize msghdr for receiving packets */
 164         rcviov[0].iov_base = (caddr_t)answer;
 165         rcviov[0].iov_len = sizeof(answer);
 166         rcvmhdr.msg_name = (caddr_t)&from;
 167         rcvmhdr.msg_namelen = sizeof(from);
 168         rcvmhdr.msg_iov = rcviov;
 169         rcvmhdr.msg_iovlen = 1;
 170         rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
 171         rcvmhdr.msg_controllen = rcvcmsglen;
 172
 173         /* initialize msghdr for sending packets */
 174         sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
 175         sndmhdr.msg_iov = sndiov;
 176         sndmhdr.msg_iovlen = 1;
 177         sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
 178         sndmhdr.msg_controllen = sndcmsglen;
 179
 180         return(rssock);
 181 }
 182
 183 void
 184 sendpacket(struct ifinfo *ifinfo)
 185 {
 186         ssize_t i;
 187         struct cmsghdr *cm;
 188         struct in6_pktinfo *pi;
 189
 190         sndmhdr.msg_name = (caddr_t)&sin6_allrouters;
 191         sndmhdr.msg_iov[0].iov_base = (caddr_t)ifinfo->rs_data;
 192         sndmhdr.msg_iov[0].iov_len = ifinfo->rs_datalen;
 193
 194         cm = CMSG_FIRSTHDR(&sndmhdr);
 195         /* specify the outgoing interface */
 196         cm->cmsg_level = IPPROTO_IPV6;
 197         cm->cmsg_type = IPV6_PKTINFO;
 198         cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
 199         pi = (struct in6_pktinfo *)CMSG_DATA(cm);
 200         memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
 201         pi->ipi6_ifindex = ifinfo->sdl->sdl_index;
 202
 203         /* specify the hop limit of the packet */
 204         {
 205                 int hoplimit = 255;
 206
 207                 cm = CMSG_NXTHDR(&sndmhdr, cm);
 208                 cm->cmsg_level = IPPROTO_IPV6;
 209                 cm->cmsg_type = IPV6_HOPLIMIT;
 210                 cm->cmsg_len = CMSG_LEN(sizeof(int));
 211                 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
 212         }
 213
 214         warnmsg(LOG_DEBUG,
 215                __func__, "send RS on %s, whose state is %d",
 216                ifinfo->ifname, ifinfo->state);
 217
 218         i = sendmsg(rssock, &sndmhdr, 0);
 219
 220         if (i < 0 || (size_t)i != ifinfo->rs_datalen) {
 221                 /*
 222                  * ENETDOWN is not so serious, especially when using several
 223                  * network cards on a mobile node. We ignore it.
 224                  */
 225                 if (errno != ENETDOWN || dflag > 0)
 226                         warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s",
 227                                 ifinfo->ifname, strerror(errno));
 228         }
 229
 230         /* update counter */
 231         ifinfo->probes++;
 232 }
 233
 234 void
 235 rtsol_input(int s)
 236 {
 237         ssize_t i;
 238         int *hlimp = NULL;
 239         struct icmp6_hdr *icp;
 240         int ifindex = 0;
 241         struct cmsghdr *cm;
 242         struct in6_pktinfo *pi = NULL;
 243         struct ifinfo *ifi = NULL;
 244         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 245
 246         /* get message */
 247         if ((i = recvmsg(s, &rcvmhdr, 0)) < 0) {
 248                 warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno));
 249                 return;
 250         }
 251
 252         /* extract optional information via Advanced API */
 253         for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
 254              cm;
 255              cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
 256                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 257                     cm->cmsg_type == IPV6_PKTINFO &&
 258                     cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
 259                         pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
 260                         ifindex = pi->ipi6_ifindex;
 261                 }
 262                 if (cm->cmsg_level == IPPROTO_IPV6 &&
 263                     cm->cmsg_type == IPV6_HOPLIMIT &&
 264                     cm->cmsg_len == CMSG_LEN(sizeof(int)))
 265                         hlimp = (int *)CMSG_DATA(cm);
 266         }
 267
 268         if (ifindex == 0) {
 269                 warnmsg(LOG_ERR,
 270                        __func__, "failed to get receiving interface");
 271                 return;
 272         }
 273         if (hlimp == NULL) {
 274                 warnmsg(LOG_ERR,
 275                        __func__, "failed to get receiving hop limit");
 276                 return;
 277         }
 278
 279         if ((size_t)i < sizeof(struct nd_router_advert)) {
 280                 warnmsg(LOG_ERR,
 281                        __func__, "packet size(%d) is too short", i);
 282                 return;
 283         }
 284
 285         icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
 286
 287         if (icp->icmp6_type != ND_ROUTER_ADVERT) {
 288                 warnmsg(LOG_ERR, __func__,
 289                         "invalid icmp type(%d) from %s on %s", icp->icmp6_type,
 290                        inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 291                                  INET6_ADDRSTRLEN),
 292                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 293                 return;
 294         }
 295
 296         if (icp->icmp6_code != 0) {
 297                 warnmsg(LOG_ERR, __func__,
 298                         "invalid icmp code(%d) from %s on %s", icp->icmp6_code,
 299                        inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 300                                  INET6_ADDRSTRLEN),
 301                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 302                 return;
 303         }
 304
 305         if (*hlimp != 255) {
 306                 warnmsg(LOG_NOTICE, __func__,
 307                         "invalid RA with hop limit(%d) from %s on %s",
 308                        *hlimp,
 309                        inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 310                                  INET6_ADDRSTRLEN),
 311                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 312                 return;
 313         }
 314
 315         if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) {
 316                 warnmsg(LOG_NOTICE, __func__,
 317                         "invalid RA with non link-local source from %s on %s",
 318                        inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 319                                  INET6_ADDRSTRLEN),
 320                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 321                 return;
 322         }
 323
 324         /* xxx: more validation? */
 325
 326         if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) {
 327                 warnmsg(LOG_NOTICE, __func__,
 328                         "received RA from %s on an unexpeced IF(%s)",
 329                        inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 330                                  INET6_ADDRSTRLEN),
 331                        if_indextoname(pi->ipi6_ifindex, ifnamebuf));
 332                 return;
 333         }
 334
 335         warnmsg(LOG_DEBUG, __func__,
 336                 "received RA from %s on %s, state is %d",
 337                inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
 338                          INET6_ADDRSTRLEN),
 339                ifi->ifname, ifi->state);
 340
 341         ifi->racnt++;
 342
 343         switch(ifi->state) {
 344          case IFS_IDLE:         /* should be ignored */
 345          case IFS_DELAY:                /* right? */
 346                  break;
 347          case IFS_PROBE:
 348                  ifi->state = IFS_IDLE;
 349                  ifi->probes = 0;
 350                  rtsol_timer_update(ifi);
 351                  break;
 352         }
 353 }