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: src/usr.sbin/rtsold/rtsol.c,v 1.1.2.4 2002/04/24 10:22:30 suz Exp $
32 * $DragonFly: src/usr.sbin/rtsold/rtsol.c,v 1.7 2008/11/02 21:52:46 swildner Exp $
33 */
34
35 #include <sys/param.h>
36 #include <sys/socket.h>
37 #include <sys/uio.h>
38 #include <sys/time.h>
39 #include <sys/queue.h>
40
41 #include <net/if.h>
42 #include <net/route.h>
43 #include <net/if_dl.h>
44
45 #include <netinet/in.h>
46 #include <netinet/ip6.h>
47 #include <netinet6/ip6_var.h>
48 #include <netinet/icmp6.h>
49
50 #include <arpa/inet.h>
51
52 #include <time.h>
53 #include <unistd.h>
54 #include <stdio.h>
55 #include <err.h>
56 #include <errno.h>
57 #include <string.h>
58 #include <stdlib.h>
59 #include <syslog.h>
60 #include "rtsold.h"
61
62 #define ALLROUTER "ff02::2"
63
64 static struct msghdr rcvmhdr;
65 static struct msghdr sndmhdr;
66 static struct iovec rcviov[2];
67 static struct iovec sndiov[2];
68 static struct sockaddr_in6 from;
69
70 int rssock;
71
72 static struct sockaddr_in6 sin6_allrouters = {
73 sizeof(sin6_allrouters),
74 AF_INET6,
75 0,
76 0,
77 IN6ADDR_ANY_INIT,
78 0
79 };
80
81 int
sockopen(void)82 sockopen(void)
83 {
84 int on;
85 struct icmp6_filter filt;
86 static u_char answer[1500];
87 int rcvcmsglen, sndcmsglen;
88 static u_char *rcvcmsgbuf = NULL, *sndcmsgbuf = NULL;
89
90 sndcmsglen = rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
91 CMSG_SPACE(sizeof(int));
92 if (rcvcmsgbuf == NULL && (rcvcmsgbuf = malloc(rcvcmsglen)) == NULL) {
93 warnmsg(LOG_ERR, __func__,
94 "malloc for receive msghdr failed");
95 return(-1);
96 }
97 if (sndcmsgbuf == NULL && (sndcmsgbuf = malloc(sndcmsglen)) == NULL) {
98 warnmsg(LOG_ERR, __func__,
99 "malloc for send msghdr failed");
100 return(-1);
101 }
102 memset(&sin6_allrouters, 0, sizeof(struct sockaddr_in6));
103 sin6_allrouters.sin6_family = AF_INET6;
104 sin6_allrouters.sin6_len = sizeof(sin6_allrouters);
105 if (inet_pton(AF_INET6, ALLROUTER,
106 &sin6_allrouters.sin6_addr.s6_addr) != 1) {
107 warnmsg(LOG_ERR, __func__, "inet_pton failed for %s",
108 ALLROUTER);
109 return(-1);
110 }
111
112 if ((rssock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
113 warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
114 return(-1);
115 }
116
117 /* specify to tell receiving interface */
118 on = 1;
119 #ifdef IPV6_RECVPKTINFO
120 if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
121 sizeof(on)) < 0) {
122 warnmsg(LOG_ERR, __func__, "IPV6_RECVPKTINFO: %s",
123 strerror(errno));
124 exit(1);
125 }
126 #else /* old adv. API */
127 if (setsockopt(rssock, IPPROTO_IPV6, IPV6_PKTINFO, &on,
128 sizeof(on)) < 0) {
129 warnmsg(LOG_ERR, __func__, "IPV6_PKTINFO: %s",
130 strerror(errno));
131 exit(1);
132 }
133 #endif
134
135 on = 1;
136 /* specify to tell value of hoplimit field of received IP6 hdr */
137 #ifdef IPV6_RECVHOPLIMIT
138 if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
139 sizeof(on)) < 0) {
140 warnmsg(LOG_ERR, __func__, "IPV6_RECVHOPLIMIT: %s",
141 strerror(errno));
142 exit(1);
143 }
144 #else /* old adv. API */
145 if (setsockopt(rssock, IPPROTO_IPV6, IPV6_HOPLIMIT, &on,
146 sizeof(on)) < 0) {
147 warnmsg(LOG_ERR, __func__, "IPV6_HOPLIMIT: %s",
148 strerror(errno));
149 exit(1);
150 }
151 #endif
152
153 /* specfiy to accept only router advertisements on the socket */
154 ICMP6_FILTER_SETBLOCKALL(&filt);
155 ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
156 if (setsockopt(rssock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
157 sizeof(filt)) == -1) {
158 warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s",
159 strerror(errno));
160 return(-1);
161 }
162
163 /* initialize msghdr for receiving packets */
164 rcviov[0].iov_base = (caddr_t)answer;
165 rcviov[0].iov_len = sizeof(answer);
166 rcvmhdr.msg_name = (caddr_t)&from;
167 rcvmhdr.msg_namelen = sizeof(from);
168 rcvmhdr.msg_iov = rcviov;
169 rcvmhdr.msg_iovlen = 1;
170 rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
171 rcvmhdr.msg_controllen = rcvcmsglen;
172
173 /* initialize msghdr for sending packets */
174 sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
175 sndmhdr.msg_iov = sndiov;
176 sndmhdr.msg_iovlen = 1;
177 sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
178 sndmhdr.msg_controllen = sndcmsglen;
179
180 return(rssock);
181 }
182
183 void
sendpacket(struct ifinfo * ifinfo)184 sendpacket(struct ifinfo *ifinfo)
185 {
186 ssize_t i;
187 struct cmsghdr *cm;
188 struct in6_pktinfo *pi;
189
190 sndmhdr.msg_name = (caddr_t)&sin6_allrouters;
191 sndmhdr.msg_iov[0].iov_base = (caddr_t)ifinfo->rs_data;
192 sndmhdr.msg_iov[0].iov_len = ifinfo->rs_datalen;
193
194 cm = CMSG_FIRSTHDR(&sndmhdr);
195 /* specify the outgoing interface */
196 cm->cmsg_level = IPPROTO_IPV6;
197 cm->cmsg_type = IPV6_PKTINFO;
198 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
199 pi = (struct in6_pktinfo *)CMSG_DATA(cm);
200 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
201 pi->ipi6_ifindex = ifinfo->sdl->sdl_index;
202
203 /* specify the hop limit of the packet */
204 {
205 int hoplimit = 255;
206
207 cm = CMSG_NXTHDR(&sndmhdr, cm);
208 cm->cmsg_level = IPPROTO_IPV6;
209 cm->cmsg_type = IPV6_HOPLIMIT;
210 cm->cmsg_len = CMSG_LEN(sizeof(int));
211 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
212 }
213
214 warnmsg(LOG_DEBUG,
215 __func__, "send RS on %s, whose state is %d",
216 ifinfo->ifname, ifinfo->state);
217
218 i = sendmsg(rssock, &sndmhdr, 0);
219
220 if (i < 0 || (size_t)i != ifinfo->rs_datalen) {
221 /*
222 * ENETDOWN is not so serious, especially when using several
223 * network cards on a mobile node. We ignore it.
224 */
225 if (errno != ENETDOWN || dflag > 0)
226 warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s",
227 ifinfo->ifname, strerror(errno));
228 }
229
230 /* update counter */
231 ifinfo->probes++;
232 }
233
234 void
rtsol_input(int s)235 rtsol_input(int s)
236 {
237 ssize_t i;
238 int *hlimp = NULL;
239 struct icmp6_hdr *icp;
240 int ifindex = 0;
241 struct cmsghdr *cm;
242 struct in6_pktinfo *pi = NULL;
243 struct ifinfo *ifi = NULL;
244 u_char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
245
246 /* get message */
247 if ((i = recvmsg(s, &rcvmhdr, 0)) < 0) {
248 warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno));
249 return;
250 }
251
252 /* extract optional information via Advanced API */
253 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr);
254 cm;
255 cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
256 if (cm->cmsg_level == IPPROTO_IPV6 &&
257 cm->cmsg_type == IPV6_PKTINFO &&
258 cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
259 pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
260 ifindex = pi->ipi6_ifindex;
261 }
262 if (cm->cmsg_level == IPPROTO_IPV6 &&
263 cm->cmsg_type == IPV6_HOPLIMIT &&
264 cm->cmsg_len == CMSG_LEN(sizeof(int)))
265 hlimp = (int *)CMSG_DATA(cm);
266 }
267
268 if (ifindex == 0) {
269 warnmsg(LOG_ERR,
270 __func__, "failed to get receiving interface");
271 return;
272 }
273 if (hlimp == NULL) {
274 warnmsg(LOG_ERR,
275 __func__, "failed to get receiving hop limit");
276 return;
277 }
278
279 if ((size_t)i < sizeof(struct nd_router_advert)) {
280 warnmsg(LOG_ERR,
281 __func__, "packet size(%zd) is too short", i);
282 return;
283 }
284
285 icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
286
287 if (icp->icmp6_type != ND_ROUTER_ADVERT) {
288 warnmsg(LOG_ERR, __func__,
289 "invalid icmp type(%d) from %s on %s", icp->icmp6_type,
290 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
291 INET6_ADDRSTRLEN),
292 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
293 return;
294 }
295
296 if (icp->icmp6_code != 0) {
297 warnmsg(LOG_ERR, __func__,
298 "invalid icmp code(%d) from %s on %s", icp->icmp6_code,
299 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
300 INET6_ADDRSTRLEN),
301 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
302 return;
303 }
304
305 if (*hlimp != 255) {
306 warnmsg(LOG_NOTICE, __func__,
307 "invalid RA with hop limit(%d) from %s on %s",
308 *hlimp,
309 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
310 INET6_ADDRSTRLEN),
311 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
312 return;
313 }
314
315 if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) {
316 warnmsg(LOG_NOTICE, __func__,
317 "invalid RA with non link-local source from %s on %s",
318 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
319 INET6_ADDRSTRLEN),
320 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
321 return;
322 }
323
324 /* xxx: more validation? */
325
326 if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) {
327 warnmsg(LOG_NOTICE, __func__,
328 "received RA from %s on an unexpected IF(%s)",
329 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
330 INET6_ADDRSTRLEN),
331 if_indextoname(pi->ipi6_ifindex, ifnamebuf));
332 return;
333 }
334
335 warnmsg(LOG_DEBUG, __func__,
336 "received RA from %s on %s, state is %d",
337 inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
338 INET6_ADDRSTRLEN),
339 ifi->ifname, ifi->state);
340
341 ifi->racnt++;
342
343 switch(ifi->state) {
344 case IFS_IDLE: /* should be ignored */
345 case IFS_DELAY: /* right? */
346 break;
347 case IFS_PROBE:
348 ifi->state = IFS_IDLE;
349 ifi->probes = 0;
350 rtsol_timer_update(ifi);
351 break;
352 }
353 }
354