probe.c revision 124524
1/* $KAME: probe.c,v 1.17 2003/10/05 00:09:36 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: head/usr.sbin/rtsold/probe.c 124524 2004-01-14 17:16:19Z ume $ 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#include <net/if_var.h> 43#include <net/if_dl.h> 44 45#include <netinet/in.h> 46#include <netinet6/in6_var.h> 47#include <netinet/icmp6.h> 48#include <netinet6/nd6.h> 49 50#include <arpa/inet.h> 51 52#include <errno.h> 53#include <unistd.h> 54#include <string.h> 55#include <syslog.h> 56#include <stdlib.h> 57 58#include "rtsold.h" 59 60static struct msghdr sndmhdr; 61static struct iovec sndiov[2]; 62static int probesock; 63static void sendprobe __P((struct in6_addr *, struct ifinfo *)); 64 65int 66probe_init(void) 67{ 68 int scmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) + 69 CMSG_SPACE(sizeof(int)); 70 static u_char *sndcmsgbuf = NULL; 71 72 if (sndcmsgbuf == NULL && 73 (sndcmsgbuf = (u_char *)malloc(scmsglen)) == NULL) { 74 warnmsg(LOG_ERR, __func__, "malloc failed"); 75 return(-1); 76 } 77 78 if ((probesock = socket(AF_INET6, SOCK_RAW, IPPROTO_NONE)) < 0) { 79 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno)); 80 return(-1); 81 } 82 83 /* make the socket send-only */ 84 if (shutdown(probesock, 0)) { 85 warnmsg(LOG_ERR, __func__, "shutdown: %s", strerror(errno)); 86 return(-1); 87 } 88 89 /* initialize msghdr for sending packets */ 90 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6); 91 sndmhdr.msg_iov = sndiov; 92 sndmhdr.msg_iovlen = 1; 93 sndmhdr.msg_control = (caddr_t)sndcmsgbuf; 94 sndmhdr.msg_controllen = scmsglen; 95 return(0); 96} 97 98/* 99 * Probe if each router in the default router list is still alive. 100 */ 101void 102defrouter_probe(struct ifinfo *ifinfo) 103{ 104 u_char ntopbuf[INET6_ADDRSTRLEN]; 105 struct in6_drlist dr; 106 int s, i; 107 int ifindex = ifinfo->sdl->sdl_index; 108 109 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 110 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno)); 111 return; 112 } 113 memset(&dr, 0, sizeof(dr)); 114 strlcpy(dr.ifname, "lo0", sizeof dr.ifname); /* dummy interface */ 115 if (ioctl(s, SIOCGDRLST_IN6, (caddr_t)&dr) < 0) { 116 warnmsg(LOG_ERR, __func__, "ioctl(SIOCGDRLST_IN6): %s", 117 strerror(errno)); 118 goto closeandend; 119 } 120 121 for (i = 0; dr.defrouter[i].if_index && i < PRLSTSIZ; i++) { 122 if (ifindex && dr.defrouter[i].if_index == ifindex) { 123 /* sanity check */ 124 if (!IN6_IS_ADDR_LINKLOCAL(&dr.defrouter[i].rtaddr)) { 125 warnmsg(LOG_ERR, __func__, 126 "default router list contains a " 127 "non-link-local address(%s)", 128 inet_ntop(AF_INET6, 129 &dr.defrouter[i].rtaddr, 130 ntopbuf, INET6_ADDRSTRLEN)); 131 continue; /* ignore the address */ 132 } 133 sendprobe(&dr.defrouter[i].rtaddr, ifinfo); 134 } 135 } 136 137closeandend: 138 close(s); 139} 140 141static void 142sendprobe(struct in6_addr *addr, struct ifinfo *ifinfo) 143{ 144 u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; 145 struct sockaddr_in6 sa6_probe; 146 struct in6_pktinfo *pi; 147 struct cmsghdr *cm; 148 u_int32_t ifindex = ifinfo->sdl->sdl_index; 149 int hoplimit = 1; 150 151 memset(&sa6_probe, 0, sizeof(sa6_probe)); 152 sa6_probe.sin6_family = AF_INET6; 153 sa6_probe.sin6_len = sizeof(sa6_probe); 154 sa6_probe.sin6_addr = *addr; 155 sa6_probe.sin6_scope_id = ifinfo->linkid; 156 157 sndmhdr.msg_name = (caddr_t)&sa6_probe; 158 sndmhdr.msg_iov[0].iov_base = NULL; 159 sndmhdr.msg_iov[0].iov_len = 0; 160 161 cm = CMSG_FIRSTHDR(&sndmhdr); 162 /* specify the outgoing interface */ 163 cm->cmsg_level = IPPROTO_IPV6; 164 cm->cmsg_type = IPV6_PKTINFO; 165 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); 166 pi = (struct in6_pktinfo *)CMSG_DATA(cm); 167 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/ 168 pi->ipi6_ifindex = ifindex; 169 170 /* specify the hop limit of the packet for safety */ 171 cm = CMSG_NXTHDR(&sndmhdr, cm); 172 cm->cmsg_level = IPPROTO_IPV6; 173 cm->cmsg_type = IPV6_HOPLIMIT; 174 cm->cmsg_len = CMSG_LEN(sizeof(int)); 175 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int)); 176 177 warnmsg(LOG_DEBUG, __func__, "probe a router %s on %s", 178 inet_ntop(AF_INET6, addr, ntopbuf, INET6_ADDRSTRLEN), 179 if_indextoname(ifindex, ifnamebuf)); 180 181 if (sendmsg(probesock, &sndmhdr, 0)) 182 warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s", 183 if_indextoname(ifindex, ifnamebuf), strerror(errno)); 184} 185