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: releng/11.0/usr.sbin/rtsold/probe.c 286566 2015-08-10 07:45:13Z ed $ 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/sysctl.h> 39#include <sys/uio.h> 40#include <sys/queue.h> 41 42#include <net/if.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(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 /* initialize msghdr for sending packets */ 84 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6); 85 sndmhdr.msg_iov = sndiov; 86 sndmhdr.msg_iovlen = 1; 87 sndmhdr.msg_control = (caddr_t)sndcmsgbuf; 88 sndmhdr.msg_controllen = scmsglen; 89 90 return (0); 91} 92 93/* 94 * Probe if each router in the default router list is still alive. 95 */ 96void 97defrouter_probe(struct ifinfo *ifinfo) 98{ 99 struct in6_defrouter *p, *ep; 100 int ifindex, mib[4]; 101 char *buf, ntopbuf[INET6_ADDRSTRLEN]; 102 size_t l; 103 104 ifindex = ifinfo->sdl->sdl_index; 105 if (ifindex == 0) 106 return; 107 mib[0] = CTL_NET; 108 mib[1] = PF_INET6; 109 mib[2] = IPPROTO_ICMPV6; 110 mib[3] = ICMPV6CTL_ND6_DRLIST; 111 if (sysctl(mib, nitems(mib), NULL, &l, NULL, 0) < 0) { 112 warnmsg(LOG_ERR, __func__, "sysctl(ICMPV6CTL_ND6_DRLIST): %s", 113 strerror(errno)); 114 return; 115 } 116 if (l == 0) 117 return; 118 buf = malloc(l); 119 if (buf == NULL) { 120 warnmsg(LOG_ERR, __func__, "malloc(): %s", strerror(errno)); 121 return; 122 } 123 if (sysctl(mib, nitems(mib), buf, &l, NULL, 0) < 0) { 124 warnmsg(LOG_ERR, __func__, "sysctl(ICMPV6CTL_ND6_DRLIST): %s", 125 strerror(errno)); 126 free(buf); 127 return; 128 } 129 ep = (struct in6_defrouter *)(void *)(buf + l); 130 for (p = (struct in6_defrouter *)(void *)buf; p < ep; p++) { 131 if (ifindex != p->if_index) 132 continue; 133 if (!IN6_IS_ADDR_LINKLOCAL(&p->rtaddr.sin6_addr)) { 134 warnmsg(LOG_ERR, __func__, 135 "default router list contains a " 136 "non-link-local address(%s)", 137 inet_ntop(AF_INET6, &p->rtaddr.sin6_addr, ntopbuf, 138 INET6_ADDRSTRLEN)); 139 continue; /* ignore the address */ 140 } 141 sendprobe(&p->rtaddr.sin6_addr, ifinfo); 142 } 143 free(buf); 144} 145 146static void 147sendprobe(struct in6_addr *addr, struct ifinfo *ifinfo) 148{ 149 u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ]; 150 struct sockaddr_in6 sa6_probe; 151 struct in6_pktinfo *pi; 152 struct cmsghdr *cm; 153 u_int32_t ifindex = ifinfo->sdl->sdl_index; 154 int hoplimit = 1; 155 156 memset(&sa6_probe, 0, sizeof(sa6_probe)); 157 sa6_probe.sin6_family = AF_INET6; 158 sa6_probe.sin6_len = sizeof(sa6_probe); 159 sa6_probe.sin6_addr = *addr; 160 sa6_probe.sin6_scope_id = ifinfo->linkid; 161 162 sndmhdr.msg_name = (caddr_t)&sa6_probe; 163 sndmhdr.msg_iov[0].iov_base = NULL; 164 sndmhdr.msg_iov[0].iov_len = 0; 165 166 cm = CMSG_FIRSTHDR(&sndmhdr); 167 /* specify the outgoing interface */ 168 cm->cmsg_level = IPPROTO_IPV6; 169 cm->cmsg_type = IPV6_PKTINFO; 170 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); 171 pi = (struct in6_pktinfo *)(void *)CMSG_DATA(cm); 172 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/ 173 pi->ipi6_ifindex = ifindex; 174 175 /* specify the hop limit of the packet for safety */ 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 warnmsg(LOG_DEBUG, __func__, "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, __func__, "sendmsg on %s: %s", 188 if_indextoname(ifindex, ifnamebuf), strerror(errno)); 189} 190