usr.sbin/rtsold/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  * $DragonFly: src/usr.sbin/rtsold/probe.c,v 1.8 2007/05/18 17:05:12 dillon Exp $
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/types.h>
  37 #include <sys/ioctl.h>
  38 #include <sys/socket.h>
  39 #include <sys/uio.h>
  40 #include <sys/queue.h>
  41
  42 #include <net/if.h>
  43 #if defined(__DragonFly__)
  44 #include <net/if_var.h>
  45 #endif /* __DragonFly__ >= 3 */
  46
  47 #include <netinet/in.h>
  48 #include <netinet6/in6_var.h>
  49 #include <netinet/icmp6.h>
  50 #include <netinet6/nd6.h>
  51
  52 #include <arpa/inet.h>
  53
  54 #include <errno.h>
  55 #include <unistd.h>
  56 #include <string.h>
  57 #include <syslog.h>
  58 #include <stdlib.h>
  59
  60 #include "rtsold.h"
  61
  62 static struct msghdr sndmhdr;
  63 static struct iovec sndiov[2];
  64 static int probesock;
  65 static void sendprobe(struct in6_addr *addr, int ifindex);
  66
  67
  68 int
  69 probe_init(void)
  70 {
  71         int scmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
  72                 CMSG_SPACE(sizeof(int));
  73         static u_char *sndcmsgbuf = NULL;
  74
  75         if (sndcmsgbuf == NULL &&
  76             (sndcmsgbuf = (u_char *)malloc(scmsglen)) == NULL) {
  77                 warnmsg(LOG_ERR, __func__, "malloc failed");
  78                 return(-1);
  79         }
  80
  81         if ((probesock = socket(AF_INET6, SOCK_RAW, IPPROTO_NONE)) < 0) {
  82                 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
  83                 return(-1);
  84         }
  85
  86         /* make the socket send-only */
  87         if (shutdown(probesock, SHUT_RD)) {
  88                 warnmsg(LOG_ERR, __func__, "shutdown: %s", strerror(errno));
  89                 return(-1);
  90         }
  91
  92         /* initialize msghdr for sending packets */
  93         sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
  94         sndmhdr.msg_iov = sndiov;
  95         sndmhdr.msg_iovlen = 1;
  96         sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
  97         sndmhdr.msg_controllen = scmsglen;
  98
  99         return(0);
 100 }
 101
 102 /*
 103  * Probe if each router in the default router list is still alive.
 104  */
 105 void
 106 defrouter_probe(int ifindex)
 107 {
 108         struct in6_drlist dr;
 109         int s, i;
 110         u_char ntopbuf[INET6_ADDRSTRLEN];
 111
 112         if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 113                 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
 114                 return;
 115         }
 116         bzero(&dr, sizeof(dr));
 117         strcpy(dr.ifname, "lo0"); /* dummy interface */
 118         if (ioctl(s, SIOCGDRLST_IN6, (caddr_t)&dr) < 0) {
 119                 warnmsg(LOG_ERR, __func__, "ioctl(SIOCGDRLST_IN6): %s",
 120                        strerror(errno));
 121                 goto closeandend;
 122         }
 123
 124         for(i = 0; i < PRLSTSIZ && dr.defrouter[i].if_index; i++) {
 125                 if (ifindex && dr.defrouter[i].if_index == ifindex) {
 126                         /* sanity check */
 127                         if (!IN6_IS_ADDR_LINKLOCAL(&dr.defrouter[i].rtaddr)) {
 128                                 warnmsg(LOG_ERR, __func__,
 129                                         "default router list contains a "
 130                                         "non-linklocal address(%s)",
 131                                        inet_ntop(AF_INET6,
 132                                                  &dr.defrouter[i].rtaddr,
 133                                                  ntopbuf, INET6_ADDRSTRLEN));
 134                                 continue; /* ignore the address */
 135                         }
 136                         sendprobe(&dr.defrouter[i].rtaddr,
 137                                   dr.defrouter[i].if_index);
 138                 }
 139         }
 140
 141   closeandend:
 142         close(s);
 143         return;
 144 }
 145
 146 static void
 147 sendprobe(struct in6_addr *addr, int ifindex)
 148 {
 149         struct sockaddr_in6 sa6_probe;
 150         struct in6_pktinfo *pi;
 151         struct cmsghdr *cm;
 152         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
 153
 154         bzero(&sa6_probe, sizeof(sa6_probe));
 155         sa6_probe.sin6_family = AF_INET6;
 156         sa6_probe.sin6_len = sizeof(sa6_probe);
 157         sa6_probe.sin6_addr = *addr;
 158
 159         sndmhdr.msg_name = (caddr_t)&sa6_probe;
 160         sndmhdr.msg_iov[0].iov_base = NULL;
 161         sndmhdr.msg_iov[0].iov_len = 0;
 162
 163         cm = CMSG_FIRSTHDR(&sndmhdr);
 164         /* specify the outgoing interface */
 165         cm->cmsg_level = IPPROTO_IPV6;
 166         cm->cmsg_type = IPV6_PKTINFO;
 167         cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
 168         pi = (struct in6_pktinfo *)CMSG_DATA(cm);
 169         memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));       /*XXX*/
 170         pi->ipi6_ifindex = ifindex;
 171
 172         /* specify the hop limit of the packet for safety */
 173         {
 174                 int hoplimit = 1;
 175
 176                 cm = CMSG_NXTHDR(&sndmhdr, cm);
 177                 cm->cmsg_level = IPPROTO_IPV6;
 178                 cm->cmsg_type = IPV6_HOPLIMIT;
 179                 cm->cmsg_len = CMSG_LEN(sizeof(int));
 180                 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
 181         }
 182
 183         warnmsg(LOG_DEBUG, __func__, "probe a router %s on %s",
 184                inet_ntop(AF_INET6, addr, ntopbuf, INET6_ADDRSTRLEN),
 185                if_indextoname(ifindex, ifnamebuf));
 186
 187         if (sendmsg(probesock, &sndmhdr, 0))
 188                 warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s",
 189                         if_indextoname(ifindex, ifnamebuf), strerror(errno));
 190
 191         return;
 192 }