rtsol.tproj/probe.c

   1 /*      $KAME: probe.c,v 1.10 2000/08/13 06:14:59 itojun Exp $  */
   2
   3 /*
   4  * Copyright (C) 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/probe.c,v 1.2.2.3 2001/07/03 11:02:16 ume Exp $
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/types.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/socket.h>
  38 #include <sys/uio.h>
  39 #include <sys/queue.h>
  40
  41 #include <net/if.h>
  42 #if defined(__FreeBSD__) && __FreeBSD__ >= 3
  43 #include <net/if_var.h>
  44 #endif /* __FreeBSD__ >= 3 */
  45
  46 #include <netinet/in.h>
  47 #include <netinet6/in6_var.h>
  48 #include <netinet/icmp6.h>
  49 #include <netinet6/nd6.h>
  50
  51 #include <arpa/inet.h>
  52
  53 #include <errno.h>
  54 #include <unistd.h>
  55 #include <string.h>
  56 #include <syslog.h>
  57 #include <stdlib.h>
  58
  59 #include "rtsold.h"
  60
  61 static struct msghdr sndmhdr;
  62 static struct iovec sndiov[2];
  63 static int probesock;
  64 static void sendprobe __P((struct in6_addr *addr, int ifindex));
  65
  66
  67 int
  68 probe_init()
  69 {
  70         int scmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
  71                 CMSG_SPACE(sizeof(int));
  72         static u_char *sndcmsgbuf = NULL;
  73
  74         if (sndcmsgbuf == NULL &&
  75             (sndcmsgbuf = (u_char *)malloc(scmsglen)) == NULL) {
  76                 warnmsg(LOG_ERR, __FUNCTION__, "malloc failed");
  77                 return(-1);
  78         }
  79
  80         if ((probesock = socket(AF_INET6, SOCK_RAW, IPPROTO_NONE)) < 0) {
  81                 warnmsg(LOG_ERR, __FUNCTION__, "socket: %s", strerror(errno));
  82                 return(-1);
  83         }
  84
  85         /* make the socket send-only */
  86         if (shutdown(probesock, 0)) {
  87                 warnmsg(LOG_ERR, __FUNCTION__, "shutdown: %s", strerror(errno));
  88                 return(-1);
  89         }
  90
  91         /* initialize msghdr for sending packets */
  92         sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
  93         sndmhdr.msg_iov = sndiov;
  94         sndmhdr.msg_iovlen = 1;
  95         sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
  96         sndmhdr.msg_controllen = scmsglen;
  97
  98         return(0);
  99 }
 100
 101 /*
 102  * Probe if each router in the default router list is still alive.
 103  */
 104 void
 105 defrouter_probe(int ifindex)
 106 {
 107         struct in6_drlist dr;
 108         int s, i;
 109         u_char ntopbuf[INET6_ADDRSTRLEN];
 110
 111         if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 112                 warnmsg(LOG_ERR, __FUNCTION__, "socket: %s", strerror(errno));
 113                 return;
 114         }
 115         bzero(&dr, sizeof(dr));
 116         strcpy(dr.ifname, "lo0"); /* dummy interface */
 117         if (ioctl(s, SIOCGDRLST_IN6, (caddr_t)&dr) < 0) {
 118                 warnmsg(LOG_ERR, __FUNCTION__, "ioctl(SIOCGDRLST_IN6): %s",
 119                        strerror(errno));
 120                 goto closeandend;
 121         }
 122
 123         for(i = 0; dr.defrouter[i].if_index && i < PRLSTSIZ; i++) {
 124                 if (ifindex && dr.defrouter[i].if_index == ifindex) {
 125                         /* sanity check */
 126                         if (!IN6_IS_ADDR_LINKLOCAL(&dr.defrouter[i].rtaddr)) {
 127                                 warnmsg(LOG_ERR, __FUNCTION__,
 128                                         "default router list contains a "
 129                                         "non-linklocal address(%s)",
 130                                        inet_ntop(AF_INET6,
 131                                                  &dr.defrouter[i].rtaddr,
 132                                                  ntopbuf, INET6_ADDRSTRLEN));
 133                                 continue; /* ignore the address */
 134                         }
 135                         sendprobe(&dr.defrouter[i].rtaddr,
 136                                   dr.defrouter[i].if_index);
 137                 }
 138         }
 139
 140   closeandend:
 141         close(s);
 142         return;
 143 }
 144
 145 static void
 146 sendprobe(struct in6_addr *addr, int ifindex)
 147 {
 148         struct sockaddr_in6 sa6_probe;
 149         struct in6_pktinfo *pi;
 150         struct cmsghdr *cm;
 151         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];;
 152
 153         bzero(&sa6_probe, sizeof(sa6_probe));
 154         sa6_probe.sin6_family = AF_INET6;
 155         sa6_probe.sin6_len = sizeof(sa6_probe);
 156         sa6_probe.sin6_addr = *addr;
 157
 158         sndmhdr.msg_name = (caddr_t)&sa6_probe;
 159         sndmhdr.msg_iov[0].iov_base = NULL;
 160         sndmhdr.msg_iov[0].iov_len = 0;
 161
 162         cm = CMSG_FIRSTHDR(&sndmhdr);
 163         /* specify the outgoing interface */
 164         cm->cmsg_level = IPPROTO_IPV6;
 165         cm->cmsg_type = IPV6_PKTINFO;
 166         cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
 167         pi = (struct in6_pktinfo *)CMSG_DATA(cm);
 168         memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
 169         pi->ipi6_ifindex = ifindex;
 170
 171         /* specify the hop limit of the packet for safety */
 172         {
 173                 int hoplimit = 1;
 174
 175                 cm = CMSG_NXTHDR(&sndmhdr, cm);
 176                 cm->cmsg_level = IPPROTO_IPV6;
 177                 cm->cmsg_type = IPV6_HOPLIMIT;
 178                 cm->cmsg_len = CMSG_LEN(sizeof(int));
 179                 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
 180         }
 181
 182         warnmsg(LOG_DEBUG, __FUNCTION__, "probe a router %s on %s",
 183                inet_ntop(AF_INET6, addr, ntopbuf, INET6_ADDRSTRLEN),
 184                if_indextoname(ifindex, ifnamebuf));
 185
 186         if (sendmsg(probesock, &sndmhdr, 0))
 187                 warnmsg(LOG_ERR, __FUNCTION__, "sendmsg on %s: %s",
 188                         if_indextoname(ifindex, ifnamebuf), strerror(errno));
 189
 190         return;
 191 }