network_cmds/rtsol.tproj/probe.c

   1 /*
   2  * Copyright (c) 2009 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*      $KAME: probe.c,v 1.10 2000/08/13 06:14:59 itojun Exp $  */
  30
  31 /*
  32  * Copyright (C) 1998 WIDE Project.
  33  * All rights reserved.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. Neither the name of the project nor the names of its contributors
  44  *    may be used to endorse or promote products derived from this software
  45  *    without specific prior written permission.
  46  *
  47  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  48  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  50  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  51  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  52  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  53  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  54  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  55  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  57  * SUCH DAMAGE.
  58  *
  59  * $FreeBSD: src/usr.sbin/rtsold/probe.c,v 1.2.2.3 2001/07/03 11:02:16 ume Exp $
  60  */
  61
  62 #include <sys/param.h>
  63 #include <sys/types.h>
  64 #include <sys/ioctl.h>
  65 #include <sys/socket.h>
  66 #include <sys/uio.h>
  67 #include <sys/queue.h>
  68
  69 #include <net/if.h>
  70 #if defined(__FreeBSD__) && __FreeBSD__ >= 3
  71 #include <net/if_var.h>
  72 #endif /* __FreeBSD__ >= 3 */
  73
  74 #include <netinet/in.h>
  75 #include <netinet6/in6_var.h>
  76 #include <netinet/icmp6.h>
  77 #include <netinet6/nd6.h>
  78
  79 #include <arpa/inet.h>
  80
  81 #include <errno.h>
  82 #include <unistd.h>
  83 #include <string.h>
  84 #include <syslog.h>
  85 #include <stdlib.h>
  86
  87 #include "rtsold.h"
  88
  89 static struct msghdr sndmhdr;
  90 static struct iovec sndiov[2];
  91 static int probesock;
  92 static void sendprobe __P((struct in6_addr *addr, int ifindex));
  93
  94
  95 int
  96 probe_init()
  97 {
  98         int scmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
  99                 CMSG_SPACE(sizeof(int));
 100         static u_char *sndcmsgbuf = NULL;
 101
 102         if (sndcmsgbuf == NULL &&
 103             (sndcmsgbuf = (u_char *)malloc(scmsglen)) == NULL) {
 104                 warnmsg(LOG_ERR, __FUNCTION__, "malloc failed");
 105                 return(-1);
 106         }
 107
 108         if ((probesock = socket(AF_INET6, SOCK_RAW, IPPROTO_NONE)) < 0) {
 109                 warnmsg(LOG_ERR, __FUNCTION__, "socket: %s", strerror(errno));
 110                 return(-1);
 111         }
 112
 113 #ifndef __APPLE__
 114         /* make the socket send-only */
 115         if (shutdown(probesock, 0)) {
 116                 warnmsg(LOG_ERR, __FUNCTION__, "shutdown: %s", strerror(errno));
 117                 return(-1);
 118         }
 119 #endif /* __APPLE__ */
 120
 121         /* initialize msghdr for sending packets */
 122         sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
 123         sndmhdr.msg_iov = sndiov;
 124         sndmhdr.msg_iovlen = 1;
 125         sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
 126         sndmhdr.msg_controllen = scmsglen;
 127
 128         return(0);
 129 }
 130
 131 /*
 132  * Probe if each router in the default router list is still alive.
 133  */
 134 void
 135 defrouter_probe(int ifindex)
 136 {
 137         struct in6_drlist dr;
 138         int s, i;
 139         u_char ntopbuf[INET6_ADDRSTRLEN];
 140
 141         if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
 142                 warnmsg(LOG_ERR, __FUNCTION__, "socket: %s", strerror(errno));
 143                 return;
 144         }
 145         bzero(&dr, sizeof(dr));
 146         strlcpy(dr.ifname, "lo0", sizeof(dr.ifname)); /* dummy interface */
 147         if (ioctl(s, SIOCGDRLST_IN6, (caddr_t)&dr) < 0) {
 148                 warnmsg(LOG_ERR, __FUNCTION__, "ioctl(SIOCGDRLST_IN6): %s",
 149                        strerror(errno));
 150                 goto closeandend;
 151         }
 152
 153         for(i = 0; dr.defrouter[i].if_index && i < PRLSTSIZ; i++) {
 154                 if (ifindex && dr.defrouter[i].if_index == ifindex) {
 155                         /* sanity check */
 156                         if (!IN6_IS_ADDR_LINKLOCAL(&dr.defrouter[i].rtaddr)) {
 157                                 warnmsg(LOG_ERR, __FUNCTION__,
 158                                         "default router list contains a "
 159                                         "non-linklocal address(%s)",
 160                                        inet_ntop(AF_INET6,
 161                                                  &dr.defrouter[i].rtaddr,
 162                                                  (char *)ntopbuf, INET6_ADDRSTRLEN));
 163                                 continue; /* ignore the address */
 164                         }
 165                         sendprobe(&dr.defrouter[i].rtaddr,
 166                                   dr.defrouter[i].if_index);
 167                 }
 168         }
 169
 170   closeandend:
 171         close(s);
 172         return;
 173 }
 174
 175 static void
 176 sendprobe(struct in6_addr *addr, int ifindex)
 177 {
 178         struct sockaddr_in6 sa6_probe;
 179         struct in6_pktinfo *pi;
 180         struct cmsghdr *cm;
 181         u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];;
 182
 183         bzero(&sa6_probe, sizeof(sa6_probe));
 184         sa6_probe.sin6_family = AF_INET6;
 185         sa6_probe.sin6_len = sizeof(sa6_probe);
 186         sa6_probe.sin6_addr = *addr;
 187
 188         sndmhdr.msg_name = (caddr_t)&sa6_probe;
 189         sndmhdr.msg_iov[0].iov_base = NULL;
 190         sndmhdr.msg_iov[0].iov_len = 0;
 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 = ifindex;
 200
 201         /* specify the hop limit of the packet for safety */
 202         {
 203                 int hoplimit = 1;
 204
 205                 cm = CMSG_NXTHDR(&sndmhdr, cm);
 206                 cm->cmsg_level = IPPROTO_IPV6;
 207                 cm->cmsg_type = IPV6_HOPLIMIT;
 208                 cm->cmsg_len = CMSG_LEN(sizeof(int));
 209                 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
 210         }
 211
 212         warnmsg(LOG_DEBUG, __FUNCTION__, "probe a router %s on %s",
 213                inet_ntop(AF_INET6, addr, (char *)ntopbuf, INET6_ADDRSTRLEN),
 214                if_indextoname(ifindex, (char *)ifnamebuf));
 215
 216         if (sendmsg(probesock, &sndmhdr, 0))
 217                 warnmsg(LOG_ERR, __FUNCTION__, "sendmsg on %s: %s",
 218                         if_indextoname(ifindex, (char *)ifnamebuf), strerror(errno));
 219
 220         return;
 221 }