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/* $OpenBSD: probe.c,v 1.13 2009/11/11 17:23:16 deraadt Exp $ */
/* $KAME: probe.c,v 1.16 2002/06/10 20:00:36 itojun Exp $ */
/*
* Copyright (C) 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/queue.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/nd6.h>
#include <arpa/inet.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <syslog.h>
#include <stdlib.h>
#include "rtsold.h"
static struct msghdr sndmhdr;
static struct iovec sndiov[2];
static int probesock;
static void sendprobe(struct in6_addr *, struct ifinfo *);
int
probe_init(void)
{
int scmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
CMSG_SPACE(sizeof(int));
static u_char *sndcmsgbuf = NULL;
if (sndcmsgbuf == NULL &&
(sndcmsgbuf = (u_char *)malloc(scmsglen)) == NULL) {
warnmsg(LOG_ERR, __func__, "malloc failed");
return(-1);
}
if ((probesock = socket(AF_INET6, SOCK_RAW, IPPROTO_NONE)) < 0) {
warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
return(-1);
}
/* make the socket send-only */
if (shutdown(probesock, 0)) {
warnmsg(LOG_ERR, __func__, "shutdown: %s", strerror(errno));
return(-1);
}
/* initialize msghdr for sending packets */
sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
sndmhdr.msg_iov = sndiov;
sndmhdr.msg_iovlen = 1;
sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
sndmhdr.msg_controllen = scmsglen;
return(0);
}
/*
* Probe if each router in the default router list is still alive.
*/
void
defrouter_probe(struct ifinfo *ifinfo)
{
u_char ntopbuf[INET6_ADDRSTRLEN];
struct in6_drlist dr;
int s, i;
int ifindex = ifinfo->sdl->sdl_index;
if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
return;
}
memset(&dr, 0, sizeof(dr));
strlcpy(dr.ifname, "lo0", sizeof dr.ifname); /* dummy interface */
if (ioctl(s, SIOCGDRLST_IN6, (caddr_t)&dr) < 0) {
warnmsg(LOG_ERR, __func__, "ioctl(SIOCGDRLST_IN6): %s",
strerror(errno));
goto closeandend;
}
for (i = 0; i < DRLSTSIZ && dr.defrouter[i].if_index; i++) {
if (ifindex && dr.defrouter[i].if_index == ifindex) {
/* sanity check */
if (!IN6_IS_ADDR_LINKLOCAL(&dr.defrouter[i].rtaddr)) {
warnmsg(LOG_ERR, __func__,
"default router list contains a "
"non-link-local address(%s)",
inet_ntop(AF_INET6,
&dr.defrouter[i].rtaddr,
ntopbuf, INET6_ADDRSTRLEN));
continue; /* ignore the address */
}
sendprobe(&dr.defrouter[i].rtaddr, ifinfo);
}
}
closeandend:
close(s);
}
static void
sendprobe(struct in6_addr *addr, struct ifinfo *ifinfo)
{
u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
struct sockaddr_in6 sa6_probe;
struct in6_pktinfo *pi;
struct cmsghdr *cm;
u_int32_t ifindex = ifinfo->sdl->sdl_index;
int hoplimit = 1;
memset(&sa6_probe, 0, sizeof(sa6_probe));
sa6_probe.sin6_family = AF_INET6;
sa6_probe.sin6_len = sizeof(sa6_probe);
sa6_probe.sin6_addr = *addr;
sa6_probe.sin6_scope_id = ifinfo->linkid;
sndmhdr.msg_name = (caddr_t)&sa6_probe;
sndmhdr.msg_iov[0].iov_base = NULL;
sndmhdr.msg_iov[0].iov_len = 0;
cm = CMSG_FIRSTHDR(&sndmhdr);
/* specify the outgoing interface */
cm->cmsg_level = IPPROTO_IPV6;
cm->cmsg_type = IPV6_PKTINFO;
cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
pi = (struct in6_pktinfo *)CMSG_DATA(cm);
memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
pi->ipi6_ifindex = ifindex;
/* specify the hop limit of the packet for safety */
cm = CMSG_NXTHDR(&sndmhdr, cm);
cm->cmsg_level = IPPROTO_IPV6;
cm->cmsg_type = IPV6_HOPLIMIT;
cm->cmsg_len = CMSG_LEN(sizeof(int));
memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
warnmsg(LOG_DEBUG, __func__, "probe a router %s on %s",
inet_ntop(AF_INET6, addr, ntopbuf, INET6_ADDRSTRLEN),
if_indextoname(ifindex, ifnamebuf));
if (sendmsg(probesock, &sndmhdr, 0))
warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s",
if_indextoname(ifindex, ifnamebuf), strerror(errno));
}
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