rtsol.c revision 118660 
1/*	$KAME: rtsol.c,v 1.12 2001/11/12 11:47:11 jinmei Exp $	*/
2
3/*
4 * Copyright (C) 1995, 1996, 1997, and 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/rtsol.c 118660 2003-08-08 16:38:23Z ume $
32 */
33
34#include <sys/param.h>
35#include <sys/socket.h>
36#include <sys/uio.h>
37#include <sys/time.h>
38#include <sys/queue.h>
39
40#include <net/if.h>
41#include <net/route.h>
42#include <net/if_dl.h>
43
44#include <netinet/in.h>
45#include <netinet/ip6.h>
46#include <netinet6/ip6_var.h>
47#include <netinet/icmp6.h>
48
49#include <arpa/inet.h>
50
51#include <time.h>
52#include <unistd.h>
53#include <stdio.h>
54#include <err.h>
55#include <errno.h>
56#include <string.h>
57#include <stdlib.h>
58#include <syslog.h>
59#include "rtsold.h"
60
61#define ALLROUTER "ff02::2"
62
63static struct msghdr rcvmhdr;
64static struct msghdr sndmhdr;
65static struct iovec rcviov[2];
66static struct iovec sndiov[2];
67static struct sockaddr_in6 from;
68
69int rssock;
70
71static struct sockaddr_in6 sin6_allrouters = {sizeof(sin6_allrouters), AF_INET6};
72
73int
74sockopen()
75{
76	int on;
77	struct icmp6_filter filt;
78	static u_char answer[1500];
79	int rcvcmsglen, sndcmsglen;
80	static u_char *rcvcmsgbuf = NULL, *sndcmsgbuf = NULL;
81
82	sndcmsglen = rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
83		CMSG_SPACE(sizeof(int));
84	if (rcvcmsgbuf == NULL && (rcvcmsgbuf = malloc(rcvcmsglen)) == NULL) {
85		warnmsg(LOG_ERR, __func__,
86			"malloc for receive msghdr failed");
87		return(-1);
88	}
89	if (sndcmsgbuf == NULL && (sndcmsgbuf = malloc(sndcmsglen)) == NULL) {
90		warnmsg(LOG_ERR, __func__,
91			"malloc for send msghdr failed");
92		return(-1);
93	}
94	memset(&sin6_allrouters, 0, sizeof(struct sockaddr_in6));
95	sin6_allrouters.sin6_family = AF_INET6;
96	sin6_allrouters.sin6_len = sizeof(sin6_allrouters);
97	if (inet_pton(AF_INET6, ALLROUTER,
98		      &sin6_allrouters.sin6_addr.s6_addr) != 1) {
99		warnmsg(LOG_ERR, __func__, "inet_pton failed for %s",
100		       ALLROUTER);
101		return(-1);
102	}
103
104	if ((rssock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
105		warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
106		return(-1);
107	}
108
109	/* specify to tell receiving interface */
110	on = 1;
111#ifdef IPV6_RECVPKTINFO
112	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
113		       sizeof(on)) < 0) {
114		warnmsg(LOG_ERR, __func__, "IPV6_RECVPKTINFO: %s",
115		       strerror(errno));
116		exit(1);
117	}
118#else  /* old adv. API */
119	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
120		       sizeof(on)) < 0) {
121		warnmsg(LOG_ERR, __func__, "IPV6_PKTINFO: %s",
122		       strerror(errno));
123		exit(1);
124	}
125#endif
126
127	on = 1;
128	/* specify to tell value of hoplimit field of received IP6 hdr */
129#ifdef IPV6_RECVHOPLIMIT
130	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
131		       sizeof(on)) < 0) {
132		warnmsg(LOG_ERR, __func__, "IPV6_RECVHOPLIMIT: %s",
133		       strerror(errno));
134		exit(1);
135	}
136#else  /* old adv. API */
137	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
138		       sizeof(on)) < 0) {
139		warnmsg(LOG_ERR, __func__, "IPV6_HOPLIMIT: %s",
140		       strerror(errno));
141		exit(1);
142	}
143#endif
144
145	/* specfiy to accept only router advertisements on the socket */
146	ICMP6_FILTER_SETBLOCKALL(&filt);
147	ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
148	if (setsockopt(rssock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
149		       sizeof(filt)) == -1) {
150		warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s",
151		       strerror(errno));
152		return(-1);
153	}
154
155	/* initialize msghdr for receiving packets */
156	rcviov[0].iov_base = (caddr_t)answer;
157	rcviov[0].iov_len = sizeof(answer);
158	rcvmhdr.msg_name = (caddr_t)&from;
159	rcvmhdr.msg_namelen = sizeof(from);
160	rcvmhdr.msg_iov = rcviov;
161	rcvmhdr.msg_iovlen = 1;
162	rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
163	rcvmhdr.msg_controllen = rcvcmsglen;
164
165	/* initialize msghdr for sending packets */
166	sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
167	sndmhdr.msg_iov = sndiov;
168	sndmhdr.msg_iovlen = 1;
169	sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
170	sndmhdr.msg_controllen = sndcmsglen;
171
172	return(rssock);
173}
174
175void
176sendpacket(struct ifinfo *ifinfo)
177{
178	int i;
179	struct cmsghdr *cm;
180	struct in6_pktinfo *pi;
181
182	sndmhdr.msg_name = (caddr_t)&sin6_allrouters;
183	sndmhdr.msg_iov[0].iov_base = (caddr_t)ifinfo->rs_data;
184	sndmhdr.msg_iov[0].iov_len = ifinfo->rs_datalen;
185
186	cm = CMSG_FIRSTHDR(&sndmhdr);
187	/* specify the outgoing interface */
188	cm->cmsg_level = IPPROTO_IPV6;
189	cm->cmsg_type = IPV6_PKTINFO;
190	cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
191	pi = (struct in6_pktinfo *)CMSG_DATA(cm);
192	memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));	/*XXX*/
193	pi->ipi6_ifindex = ifinfo->sdl->sdl_index;
194
195	/* specify the hop limit of the packet */
196	{
197		int hoplimit = 255;
198
199		cm = CMSG_NXTHDR(&sndmhdr, cm);
200		cm->cmsg_level = IPPROTO_IPV6;
201		cm->cmsg_type = IPV6_HOPLIMIT;
202		cm->cmsg_len = CMSG_LEN(sizeof(int));
203		memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
204	}
205
206	warnmsg(LOG_DEBUG,
207	       __func__, "send RS on %s, whose state is %d",
208	       ifinfo->ifname, ifinfo->state);
209
210	i = sendmsg(rssock, &sndmhdr, 0);
211
212	if (i < 0 || i != ifinfo->rs_datalen) {
213		/*
214		 * ENETDOWN is not so serious, especially when using several
215		 * network cards on a mobile node. We ignore it.
216		 */
217		if (errno != ENETDOWN || dflag > 0)
218			warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s",
219				ifinfo->ifname, strerror(errno));
220	}
221
222	/* update counter */
223	ifinfo->probes++;
224}
225
226void
227rtsol_input(int s)
228{
229	int i;
230	int *hlimp = NULL;
231	struct icmp6_hdr *icp;
232	int ifindex = 0;
233	struct cmsghdr *cm;
234	struct in6_pktinfo *pi = NULL;
235	struct ifinfo *ifi = NULL;
236	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
237
238	/* get message */
239	if ((i = recvmsg(s, &rcvmhdr, 0)) < 0) {
240		warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno));
241		return;
242	}
243
244	/* extract optional information via Advanced API */
245	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
246	     cm;
247	     cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
248		if (cm->cmsg_level == IPPROTO_IPV6 &&
249		    cm->cmsg_type == IPV6_PKTINFO &&
250		    cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
251			pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
252			ifindex = pi->ipi6_ifindex;
253		}
254		if (cm->cmsg_level == IPPROTO_IPV6 &&
255		    cm->cmsg_type == IPV6_HOPLIMIT &&
256		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
257			hlimp = (int *)CMSG_DATA(cm);
258	}
259
260	if (ifindex == 0) {
261		warnmsg(LOG_ERR,
262		       __func__, "failed to get receiving interface");
263		return;
264	}
265	if (hlimp == NULL) {
266		warnmsg(LOG_ERR,
267		       __func__, "failed to get receiving hop limit");
268		return;
269	}
270
271	if (i < sizeof(struct nd_router_advert)) {
272		warnmsg(LOG_ERR,
273		       __func__, "packet size(%d) is too short", i);
274		return;
275	}
276
277	icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
278
279	if (icp->icmp6_type != ND_ROUTER_ADVERT) {
280		warnmsg(LOG_ERR, __func__,
281			"invalid icmp type(%d) from %s on %s", icp->icmp6_type,
282		       inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
283				 INET6_ADDRSTRLEN),
284		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
285		return;
286	}
287
288	if (icp->icmp6_code != 0) {
289		warnmsg(LOG_ERR, __func__,
290			"invalid icmp code(%d) from %s on %s", icp->icmp6_code,
291		       inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
292				 INET6_ADDRSTRLEN),
293		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
294		return;
295	}
296
297	if (*hlimp != 255) {
298		warnmsg(LOG_NOTICE, __func__,
299			"invalid RA with hop limit(%d) from %s on %s",
300		       *hlimp,
301		       inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
302				 INET6_ADDRSTRLEN),
303		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
304		return;
305	}
306
307	if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) {
308		warnmsg(LOG_NOTICE, __func__,
309			"invalid RA with non link-local source from %s on %s",
310		       inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
311				 INET6_ADDRSTRLEN),
312		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
313		return;
314	}
315
316	/* xxx: more validation? */
317
318	if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) {
319		warnmsg(LOG_NOTICE, __func__,
320			"received RA from %s on an unexpeced IF(%s)",
321		       inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
322				 INET6_ADDRSTRLEN),
323		       if_indextoname(pi->ipi6_ifindex, ifnamebuf));
324		return;
325	}
326
327	warnmsg(LOG_DEBUG, __func__,
328		"received RA from %s on %s, state is %d",
329	       inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
330			 INET6_ADDRSTRLEN),
331	       ifi->ifname, ifi->state);
332
333	ifi->racnt++;
334
335	switch(ifi->state) {
336	 case IFS_IDLE:		/* should be ignored */
337	 case IFS_DELAY:		/* right? */
338		 break;
339	 case IFS_PROBE:
340		 ifi->state = IFS_IDLE;
341		 ifi->probes = 0;
342		 rtsol_timer_update(ifi);
343		 break;
344	}
345}
346