1/*	$KAME: rtsol.c,v 1.11 2000/08/13 06:14:59 itojun 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: src/usr.sbin/rtsold/rtsol.c,v 1.1.2.3 2001/07/03 11:02:16 ume Exp $
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, __FUNCTION__,
86			"malloc for receive msghdr failed");
87		return(-1);
88	}
89	if (sndcmsgbuf == NULL && (sndcmsgbuf = malloc(sndcmsglen)) == NULL) {
90		warnmsg(LOG_ERR, __FUNCTION__,
91			"malloc for send msghdr failed");
92		return(-1);
93	}
94	memset(&sin6_allrouters, 0, sizeof(struct sockaddr_in6));
95	if (inet_pton(AF_INET6, ALLROUTER,
96		      &sin6_allrouters.sin6_addr.s6_addr) != 1) {
97		warnmsg(LOG_ERR, __FUNCTION__, "inet_pton failed for %s",
98		       ALLROUTER);
99		return(-1);
100	}
101
102	if ((rssock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
103		warnmsg(LOG_ERR, __FUNCTION__, "socket: %s", strerror(errno));
104		return(-1);
105	}
106
107	/* specify to tell receiving interface */
108	on = 1;
109#ifdef IPV6_RECVPKTINFO
110	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
111		       sizeof(on)) < 0) {
112		warnmsg(LOG_ERR, __FUNCTION__, "IPV6_RECVPKTINFO: %s",
113		       strerror(errno));
114		exit(1);
115	}
116#else  /* old adv. API */
117	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
118		       sizeof(on)) < 0) {
119		warnmsg(LOG_ERR, __FUNCTION__, "IPV6_PKTINFO: %s",
120		       strerror(errno));
121		exit(1);
122	}
123#endif
124
125	on = 1;
126	/* specify to tell value of hoplimit field of received IP6 hdr */
127#ifdef IPV6_RECVHOPLIMIT
128	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
129		       sizeof(on)) < 0) {
130		warnmsg(LOG_ERR, __FUNCTION__, "IPV6_RECVHOPLIMIT: %s",
131		       strerror(errno));
132		exit(1);
133	}
134#else  /* old adv. API */
135	if (setsockopt(rssock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
136		       sizeof(on)) < 0) {
137		warnmsg(LOG_ERR, __FUNCTION__, "IPV6_HOPLIMIT: %s",
138		       strerror(errno));
139		exit(1);
140	}
141#endif
142
143	/* specfiy to accept only router advertisements on the socket */
144	ICMP6_FILTER_SETBLOCKALL(&filt);
145	ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
146	if (setsockopt(rssock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
147		       sizeof(filt)) == -1) {
148		warnmsg(LOG_ERR, __FUNCTION__, "setsockopt(ICMP6_FILTER): %s",
149		       strerror(errno));
150		return(-1);
151	}
152
153	/* initialize msghdr for receiving packets */
154	rcviov[0].iov_base = (caddr_t)answer;
155	rcviov[0].iov_len = sizeof(answer);
156	rcvmhdr.msg_name = (caddr_t)&from;
157	rcvmhdr.msg_namelen = sizeof(from);
158	rcvmhdr.msg_iov = rcviov;
159	rcvmhdr.msg_iovlen = 1;
160	rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
161	rcvmhdr.msg_controllen = rcvcmsglen;
162
163	/* initialize msghdr for sending packets */
164	sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
165	sndmhdr.msg_iov = sndiov;
166	sndmhdr.msg_iovlen = 1;
167	sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
168	sndmhdr.msg_controllen = sndcmsglen;
169
170	return(rssock);
171}
172
173void
174sendpacket(struct ifinfo *ifinfo)
175{
176	int i;
177	struct cmsghdr *cm;
178	struct in6_pktinfo *pi;
179
180	sndmhdr.msg_name = (caddr_t)&sin6_allrouters;
181	sndmhdr.msg_iov[0].iov_base = (caddr_t)ifinfo->rs_data;
182	sndmhdr.msg_iov[0].iov_len = ifinfo->rs_datalen;
183
184	cm = CMSG_FIRSTHDR(&sndmhdr);
185	/* specify the outgoing interface */
186	cm->cmsg_level = IPPROTO_IPV6;
187	cm->cmsg_type = IPV6_PKTINFO;
188	cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
189	pi = (struct in6_pktinfo *)CMSG_DATA(cm);
190	memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr));	/*XXX*/
191	pi->ipi6_ifindex = ifinfo->sdl->sdl_index;
192
193	/* specify the hop limit of the packet */
194	{
195		int hoplimit = 255;
196
197		cm = CMSG_NXTHDR(&sndmhdr, cm);
198		cm->cmsg_level = IPPROTO_IPV6;
199		cm->cmsg_type = IPV6_HOPLIMIT;
200		cm->cmsg_len = CMSG_LEN(sizeof(int));
201		memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
202	}
203
204	warnmsg(LOG_DEBUG,
205	       __FUNCTION__, "send RS on %s, whose state is %d",
206	       ifinfo->ifname, ifinfo->state);
207
208	i = sendmsg(rssock, &sndmhdr, 0);
209
210	if (i < 0 || i != ifinfo->rs_datalen) {
211		/*
212		 * ENETDOWN is not so serious, especially when using several
213		 * network cards on a mobile node. We ignore it.
214		 */
215		if (errno != ENETDOWN || dflag > 0)
216			warnmsg(LOG_ERR, __FUNCTION__, "sendmsg on %s: %s",
217				ifinfo->ifname, strerror(errno));
218	}
219
220	/* update counter */
221	ifinfo->probes++;
222}
223
224void
225rtsol_input(int s)
226{
227	int i;
228	int *hlimp = NULL;
229	struct icmp6_hdr *icp;
230	int ifindex = 0;
231	struct cmsghdr *cm;
232	struct in6_pktinfo *pi = NULL;
233	struct ifinfo *ifi = NULL;
234	u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
235
236	/* get message */
237	if ((i = recvmsg(s, &rcvmhdr, 0)) < 0) {
238		warnmsg(LOG_ERR, __FUNCTION__, "recvmsg: %s", strerror(errno));
239		return;
240	}
241
242	/* extract optional information via Advanced API */
243	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
244	     cm;
245	     cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
246		if (cm->cmsg_level == IPPROTO_IPV6 &&
247		    cm->cmsg_type == IPV6_PKTINFO &&
248		    cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
249			pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
250			ifindex = pi->ipi6_ifindex;
251		}
252		if (cm->cmsg_level == IPPROTO_IPV6 &&
253		    cm->cmsg_type == IPV6_HOPLIMIT &&
254		    cm->cmsg_len == CMSG_LEN(sizeof(int)))
255			hlimp = (int *)CMSG_DATA(cm);
256	}
257
258	if (ifindex == 0) {
259		warnmsg(LOG_ERR,
260		       __FUNCTION__, "failed to get receiving interface");
261		return;
262	}
263	if (hlimp == NULL) {
264		warnmsg(LOG_ERR,
265		       __FUNCTION__, "failed to get receiving hop limit");
266		return;
267	}
268
269	if (i < sizeof(struct nd_router_advert)) {
270		warnmsg(LOG_ERR,
271		       __FUNCTION__, "packet size(%d) is too short", i);
272		return;
273	}
274
275	icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
276
277	if (icp->icmp6_type != ND_ROUTER_ADVERT) {
278		warnmsg(LOG_ERR, __FUNCTION__,
279			"invalid icmp type(%d) from %s on %s", icp->icmp6_type,
280		       inet_ntop(AF_INET6, &from.sin6_addr, (char *)ntopbuf,
281				 INET6_ADDRSTRLEN),
282		       if_indextoname(pi->ipi6_ifindex, (char *)ifnamebuf));
283		return;
284	}
285
286	if (icp->icmp6_code != 0) {
287		warnmsg(LOG_ERR, __FUNCTION__,
288			"invalid icmp code(%d) from %s on %s", icp->icmp6_code,
289		       inet_ntop(AF_INET6, &from.sin6_addr, (char *)ntopbuf,
290				 INET6_ADDRSTRLEN),
291		       if_indextoname(pi->ipi6_ifindex, (char *)ifnamebuf));
292		return;
293	}
294
295	if (*hlimp != 255) {
296		warnmsg(LOG_NOTICE, __FUNCTION__,
297			"invalid RA with hop limit(%d) from %s on %s",
298		       *hlimp,
299		       inet_ntop(AF_INET6, &from.sin6_addr, (char *)ntopbuf,
300				 INET6_ADDRSTRLEN),
301		       if_indextoname(pi->ipi6_ifindex, (char *)ifnamebuf));
302		return;
303	}
304
305	if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) {
306		warnmsg(LOG_NOTICE, __FUNCTION__,
307			"invalid RA with non link-local source from %s on %s",
308		       inet_ntop(AF_INET6, &from.sin6_addr, (char *)ntopbuf,
309				 INET6_ADDRSTRLEN),
310		       if_indextoname(pi->ipi6_ifindex, (char *)ifnamebuf));
311		return;
312	}
313
314	/* xxx: more validation? */
315
316	if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) {
317		warnmsg(LOG_NOTICE, __FUNCTION__,
318			"received RA from %s on an unexpeced IF(%s)",
319		       inet_ntop(AF_INET6, &from.sin6_addr, (char *)ntopbuf,
320				 INET6_ADDRSTRLEN),
321		       if_indextoname(pi->ipi6_ifindex, (char *)ifnamebuf));
322		return;
323	}
324
325	warnmsg(LOG_DEBUG, __FUNCTION__,
326		"received RA from %s on %s, state is %d",
327	       inet_ntop(AF_INET6, &from.sin6_addr, (char *)ntopbuf,
328			 INET6_ADDRSTRLEN),
329	       ifi->ifname, ifi->state);
330
331	ifi->racnt++;
332
333	switch(ifi->state) {
334	 case IFS_IDLE:		/* should be ignored */
335	 case IFS_DELAY:		/* right? */
336		 break;
337	 case IFS_PROBE:
338		 ifi->state = IFS_IDLE;
339		 ifi->probes = 0;
340		 rtsol_timer_update(ifi);
341		 break;
342	}
343}
344