rdisc.c revision 1.6 1 1.6 lukem /* $NetBSD: rdisc.c,v 1.6 1997/09/15 10:38:19 lukem Exp $ */
2 1.2 thorpej
3 1.1 thorpej /*
4 1.1 thorpej * Copyright (c) 1995
5 1.1 thorpej * The Regents of the University of California. All rights reserved.
6 1.1 thorpej *
7 1.1 thorpej * Redistribution and use in source and binary forms, with or without
8 1.1 thorpej * modification, are permitted provided that the following conditions
9 1.1 thorpej * are met:
10 1.1 thorpej * 1. Redistributions of source code must retain the above copyright
11 1.1 thorpej * notice, this list of conditions and the following disclaimer.
12 1.1 thorpej * 2. Redistributions in binary form must reproduce the above copyright
13 1.1 thorpej * notice, this list of conditions and the following disclaimer in the
14 1.1 thorpej * documentation and/or other materials provided with the distribution.
15 1.1 thorpej * 3. All advertising materials mentioning features or use of this software
16 1.1 thorpej * must display the following acknowledgement:
17 1.1 thorpej * This product includes software developed by the University of
18 1.1 thorpej * California, Berkeley and its contributors.
19 1.1 thorpej * 4. Neither the name of the University nor the names of its contributors
20 1.1 thorpej * may be used to endorse or promote products derived from this software
21 1.1 thorpej * without specific prior written permission.
22 1.1 thorpej *
23 1.1 thorpej * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 1.1 thorpej * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 1.1 thorpej * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 1.1 thorpej * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 1.1 thorpej * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 1.1 thorpej * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 1.1 thorpej * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 1.1 thorpej * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 1.1 thorpej * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 1.1 thorpej * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 1.1 thorpej * SUCH DAMAGE.
34 1.1 thorpej */
35 1.1 thorpej
36 1.4 christos #if !defined(lint) && !defined(sgi) && !defined(__NetBSD__)
37 1.1 thorpej static char sccsid[] = "@(#)rdisc.c 8.1 (Berkeley) x/y/95";
38 1.4 christos #elif defined(__NetBSD__)
39 1.6 lukem #include <sys/cdefs.h>
40 1.6 lukem __RCSID("$NetBSD: rdisc.c,v 1.6 1997/09/15 10:38:19 lukem Exp $");
41 1.2 thorpej #endif
42 1.1 thorpej
43 1.1 thorpej #include "defs.h"
44 1.1 thorpej #include <netinet/in_systm.h>
45 1.1 thorpej #include <netinet/ip.h>
46 1.1 thorpej #include <netinet/ip_icmp.h>
47 1.1 thorpej
48 1.1 thorpej /* router advertisement ICMP packet */
49 1.1 thorpej struct icmp_ad {
50 1.4 christos u_int8_t icmp_type; /* type of message */
51 1.4 christos u_int8_t icmp_code; /* type sub code */
52 1.4 christos u_int16_t icmp_cksum; /* ones complement cksum of struct */
53 1.4 christos u_int8_t icmp_ad_num; /* # of following router addresses */
54 1.4 christos u_int8_t icmp_ad_asize; /* 2--words in each advertisement */
55 1.4 christos u_int16_t icmp_ad_life; /* seconds of validity */
56 1.1 thorpej struct icmp_ad_info {
57 1.1 thorpej n_long icmp_ad_addr;
58 1.1 thorpej n_long icmp_ad_pref;
59 1.1 thorpej } icmp_ad_info[1];
60 1.1 thorpej };
61 1.1 thorpej
62 1.1 thorpej /* router solicitation ICMP packet */
63 1.1 thorpej struct icmp_so {
64 1.4 christos u_int8_t icmp_type; /* type of message */
65 1.4 christos u_int8_t icmp_code; /* type sub code */
66 1.4 christos u_int16_t icmp_cksum; /* ones complement cksum of struct */
67 1.4 christos n_long icmp_so_rsvd;
68 1.1 thorpej };
69 1.1 thorpej
70 1.1 thorpej union ad_u {
71 1.1 thorpej struct icmp icmp;
72 1.1 thorpej struct icmp_ad ad;
73 1.1 thorpej struct icmp_so so;
74 1.1 thorpej };
75 1.1 thorpej
76 1.1 thorpej
77 1.1 thorpej int rdisc_sock = -1; /* router-discovery raw socket */
78 1.1 thorpej struct interface *rdisc_sock_mcast; /* current multicast interface */
79 1.1 thorpej
80 1.1 thorpej struct timeval rdisc_timer;
81 1.1 thorpej int rdisc_ok; /* using solicited route */
82 1.1 thorpej
83 1.1 thorpej
84 1.1 thorpej #define MAX_ADS 5
85 1.1 thorpej struct dr { /* accumulated advertisements */
86 1.1 thorpej struct interface *dr_ifp;
87 1.1 thorpej naddr dr_gate; /* gateway */
88 1.1 thorpej time_t dr_ts; /* when received */
89 1.1 thorpej time_t dr_life; /* lifetime */
90 1.1 thorpej n_long dr_recv_pref; /* received but biased preference */
91 1.1 thorpej n_long dr_pref; /* preference adjusted by metric */
92 1.1 thorpej } *cur_drp, drs[MAX_ADS];
93 1.1 thorpej
94 1.1 thorpej /* adjust preference by interface metric without driving it to infinity */
95 1.1 thorpej #define PREF(p, ifp) ((p) <= (ifp)->int_metric ? ((p) != 0 ? 1 : 0) \
96 1.1 thorpej : (p) - ((ifp)->int_metric))
97 1.1 thorpej
98 1.1 thorpej static void rdisc_sort(void);
99 1.1 thorpej
100 1.1 thorpej
101 1.1 thorpej /* dump an ICMP Router Discovery Advertisement Message
102 1.1 thorpej */
103 1.1 thorpej static void
104 1.1 thorpej trace_rdisc(char *act,
105 1.1 thorpej naddr from,
106 1.1 thorpej naddr to,
107 1.1 thorpej struct interface *ifp,
108 1.1 thorpej union ad_u *p,
109 1.1 thorpej u_int len)
110 1.1 thorpej {
111 1.1 thorpej int i;
112 1.1 thorpej n_long *wp, *lim;
113 1.1 thorpej
114 1.1 thorpej
115 1.1 thorpej if (!TRACEPACKETS || ftrace == 0)
116 1.1 thorpej return;
117 1.1 thorpej
118 1.1 thorpej lastlog();
119 1.1 thorpej
120 1.1 thorpej if (p->icmp.icmp_type == ICMP_ROUTERADVERT) {
121 1.1 thorpej (void)fprintf(ftrace, "%s Router Ad"
122 1.1 thorpej " from %s to %s via %s life=%d\n",
123 1.1 thorpej act, naddr_ntoa(from), naddr_ntoa(to),
124 1.1 thorpej ifp ? ifp->int_name : "?",
125 1.1 thorpej ntohs(p->ad.icmp_ad_life));
126 1.1 thorpej if (!TRACECONTENTS)
127 1.1 thorpej return;
128 1.1 thorpej
129 1.1 thorpej wp = &p->ad.icmp_ad_info[0].icmp_ad_addr;
130 1.1 thorpej lim = &wp[(len - sizeof(p->ad)) / sizeof(*wp)];
131 1.1 thorpej for (i = 0; i < p->ad.icmp_ad_num && wp <= lim; i++) {
132 1.5 christos (void)fprintf(ftrace, "\t%s preference=%d",
133 1.4 christos naddr_ntoa(wp[0]), (int)ntohl(wp[1]));
134 1.1 thorpej wp += p->ad.icmp_ad_asize;
135 1.1 thorpej }
136 1.1 thorpej (void)fputc('\n',ftrace);
137 1.1 thorpej
138 1.1 thorpej } else {
139 1.5 christos trace_act("%s Router Solic. from %s to %s via %s value=%#x",
140 1.1 thorpej act, naddr_ntoa(from), naddr_ntoa(to),
141 1.1 thorpej ifp ? ifp->int_name : "?",
142 1.1 thorpej ntohl(p->so.icmp_so_rsvd));
143 1.1 thorpej }
144 1.1 thorpej }
145 1.1 thorpej
146 1.4 christos /* prepare Router Discovery socket.
147 1.4 christos */
148 1.4 christos static void
149 1.4 christos get_rdisc_sock(void)
150 1.4 christos {
151 1.4 christos if (rdisc_sock < 0) {
152 1.4 christos rdisc_sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
153 1.4 christos if (rdisc_sock < 0)
154 1.4 christos BADERR(1,"rdisc_sock = socket()");
155 1.4 christos fix_sock(rdisc_sock,"rdisc_sock");
156 1.4 christos fix_select();
157 1.4 christos }
158 1.4 christos }
159 1.4 christos
160 1.1 thorpej
161 1.1 thorpej /* Pick multicast group for router-discovery socket
162 1.1 thorpej */
163 1.1 thorpej void
164 1.1 thorpej set_rdisc_mg(struct interface *ifp,
165 1.5 christos int on) /* 0=turn it off */
166 1.5 christos {
167 1.1 thorpej struct ip_mreq m;
168 1.1 thorpej
169 1.4 christos if (rdisc_sock < 0) {
170 1.4 christos /* Create the raw socket so that we can hear at least
171 1.4 christos * broadcast router discovery packets.
172 1.4 christos */
173 1.4 christos if ((ifp->int_state & IS_NO_RDISC) == IS_NO_RDISC
174 1.4 christos || !on)
175 1.4 christos return;
176 1.4 christos get_rdisc_sock();
177 1.4 christos }
178 1.4 christos
179 1.5 christos if (!(ifp->int_if_flags & IFF_MULTICAST)) {
180 1.1 thorpej ifp->int_state &= ~(IS_ALL_HOSTS | IS_ALL_ROUTERS);
181 1.1 thorpej return;
182 1.1 thorpej }
183 1.1 thorpej
184 1.1 thorpej #ifdef MCAST_PPP_BUG
185 1.1 thorpej if (ifp->int_if_flags & IFF_POINTOPOINT)
186 1.1 thorpej return;
187 1.1 thorpej #endif
188 1.6 lukem memset(&m, 0, sizeof(m));
189 1.1 thorpej m.imr_interface.s_addr = ((ifp->int_if_flags & IFF_POINTOPOINT)
190 1.1 thorpej ? ifp->int_dstaddr
191 1.1 thorpej : ifp->int_addr);
192 1.1 thorpej if (supplier
193 1.1 thorpej || (ifp->int_state & IS_NO_ADV_IN)
194 1.1 thorpej || !on) {
195 1.4 christos /* stop listening to advertisements
196 1.4 christos */
197 1.1 thorpej if (ifp->int_state & IS_ALL_HOSTS) {
198 1.1 thorpej m.imr_multiaddr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
199 1.1 thorpej if (setsockopt(rdisc_sock, IPPROTO_IP,
200 1.1 thorpej IP_DROP_MEMBERSHIP,
201 1.1 thorpej &m, sizeof(m)) < 0)
202 1.1 thorpej LOGERR("IP_DROP_MEMBERSHIP ALLHOSTS");
203 1.1 thorpej ifp->int_state &= ~IS_ALL_HOSTS;
204 1.1 thorpej }
205 1.1 thorpej
206 1.1 thorpej } else if (!(ifp->int_state & IS_ALL_HOSTS)) {
207 1.4 christos /* start listening to advertisements
208 1.4 christos */
209 1.1 thorpej m.imr_multiaddr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
210 1.1 thorpej if (setsockopt(rdisc_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
211 1.1 thorpej &m, sizeof(m)) < 0) {
212 1.1 thorpej LOGERR("IP_ADD_MEMBERSHIP ALLHOSTS");
213 1.1 thorpej } else {
214 1.1 thorpej ifp->int_state |= IS_ALL_HOSTS;
215 1.1 thorpej }
216 1.1 thorpej }
217 1.1 thorpej
218 1.1 thorpej if (!supplier
219 1.1 thorpej || (ifp->int_state & IS_NO_ADV_OUT)
220 1.1 thorpej || !on) {
221 1.4 christos /* stop listening to solicitations
222 1.4 christos */
223 1.1 thorpej if (ifp->int_state & IS_ALL_ROUTERS) {
224 1.1 thorpej m.imr_multiaddr.s_addr=htonl(INADDR_ALLROUTERS_GROUP);
225 1.1 thorpej if (setsockopt(rdisc_sock, IPPROTO_IP,
226 1.1 thorpej IP_DROP_MEMBERSHIP,
227 1.1 thorpej &m, sizeof(m)) < 0)
228 1.1 thorpej LOGERR("IP_DROP_MEMBERSHIP ALLROUTERS");
229 1.1 thorpej ifp->int_state &= ~IS_ALL_ROUTERS;
230 1.1 thorpej }
231 1.1 thorpej
232 1.1 thorpej } else if (!(ifp->int_state & IS_ALL_ROUTERS)) {
233 1.4 christos /* start hearing solicitations
234 1.4 christos */
235 1.1 thorpej m.imr_multiaddr.s_addr=htonl(INADDR_ALLROUTERS_GROUP);
236 1.1 thorpej if (setsockopt(rdisc_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
237 1.1 thorpej &m, sizeof(m)) < 0) {
238 1.1 thorpej LOGERR("IP_ADD_MEMBERSHIP ALLROUTERS");
239 1.1 thorpej } else {
240 1.1 thorpej ifp->int_state |= IS_ALL_ROUTERS;
241 1.1 thorpej }
242 1.1 thorpej }
243 1.1 thorpej }
244 1.1 thorpej
245 1.1 thorpej
246 1.1 thorpej /* start supplying routes
247 1.1 thorpej */
248 1.1 thorpej void
249 1.1 thorpej set_supplier(void)
250 1.1 thorpej {
251 1.1 thorpej struct interface *ifp;
252 1.1 thorpej struct dr *drp;
253 1.1 thorpej
254 1.1 thorpej if (supplier_set)
255 1.1 thorpej return;
256 1.1 thorpej
257 1.5 christos trace_act("start suppying routes");
258 1.1 thorpej
259 1.1 thorpej /* Forget discovered routes.
260 1.1 thorpej */
261 1.1 thorpej for (drp = drs; drp < &drs[MAX_ADS]; drp++) {
262 1.1 thorpej drp->dr_recv_pref = 0;
263 1.1 thorpej drp->dr_life = 0;
264 1.1 thorpej }
265 1.1 thorpej rdisc_age(0);
266 1.1 thorpej
267 1.1 thorpej supplier_set = 1;
268 1.1 thorpej supplier = 1;
269 1.1 thorpej
270 1.1 thorpej /* Do not start advertising until we have heard some RIP routes */
271 1.1 thorpej LIM_SEC(rdisc_timer, now.tv_sec+MIN_WAITTIME);
272 1.1 thorpej
273 1.1 thorpej /* Switch router discovery multicast groups from soliciting
274 1.1 thorpej * to advertising.
275 1.1 thorpej */
276 1.1 thorpej for (ifp = ifnet; ifp; ifp = ifp->int_next) {
277 1.1 thorpej if (ifp->int_state & IS_BROKE)
278 1.1 thorpej continue;
279 1.1 thorpej ifp->int_rdisc_cnt = 0;
280 1.1 thorpej ifp->int_rdisc_timer.tv_usec = rdisc_timer.tv_usec;
281 1.1 thorpej ifp->int_rdisc_timer.tv_sec = now.tv_sec+MIN_WAITTIME;
282 1.1 thorpej set_rdisc_mg(ifp, 1);
283 1.1 thorpej }
284 1.1 thorpej
285 1.1 thorpej /* get rid of any redirects */
286 1.1 thorpej del_redirects(0,0);
287 1.1 thorpej }
288 1.1 thorpej
289 1.1 thorpej
290 1.1 thorpej /* age discovered routes and find the best one
291 1.1 thorpej */
292 1.1 thorpej void
293 1.1 thorpej rdisc_age(naddr bad_gate)
294 1.1 thorpej {
295 1.1 thorpej time_t sec;
296 1.1 thorpej struct dr *drp;
297 1.1 thorpej
298 1.1 thorpej
299 1.1 thorpej /* If only adverising, then do only that. */
300 1.1 thorpej if (supplier) {
301 1.1 thorpej /* if switching from client to server, get rid of old
302 1.1 thorpej * default routes.
303 1.1 thorpej */
304 1.1 thorpej if (cur_drp != 0)
305 1.1 thorpej rdisc_sort();
306 1.1 thorpej rdisc_adv();
307 1.1 thorpej return;
308 1.1 thorpej }
309 1.1 thorpej
310 1.1 thorpej /* If we are being told about a bad router,
311 1.1 thorpej * then age the discovered default route, and if there is
312 1.1 thorpej * no alternative, solicite a replacement.
313 1.1 thorpej */
314 1.1 thorpej if (bad_gate != 0) {
315 1.1 thorpej /* Look for the bad discovered default route.
316 1.1 thorpej * Age it and note its interface.
317 1.1 thorpej */
318 1.1 thorpej for (drp = drs; drp < &drs[MAX_ADS]; drp++) {
319 1.1 thorpej if (drp->dr_ts == 0)
320 1.1 thorpej continue;
321 1.1 thorpej
322 1.1 thorpej /* When we find the bad router, then age the route
323 1.1 thorpej * to at most SUPPLY_INTERVAL.
324 1.1 thorpej * This is contrary to RFC 1256, but defends against
325 1.1 thorpej * black holes.
326 1.1 thorpej */
327 1.1 thorpej if (drp->dr_gate == bad_gate) {
328 1.1 thorpej sec = (now.tv_sec - drp->dr_life
329 1.1 thorpej + SUPPLY_INTERVAL);
330 1.1 thorpej if (drp->dr_ts > sec) {
331 1.5 christos trace_act("age 0.0.0.0 --> %s via %s",
332 1.1 thorpej naddr_ntoa(drp->dr_gate),
333 1.1 thorpej drp->dr_ifp->int_name);
334 1.1 thorpej drp->dr_ts = sec;
335 1.1 thorpej }
336 1.1 thorpej break;
337 1.1 thorpej }
338 1.1 thorpej }
339 1.1 thorpej }
340 1.1 thorpej
341 1.1 thorpej /* delete old redirected routes to keep the kernel table small
342 1.1 thorpej */
343 1.1 thorpej sec = (cur_drp == 0) ? MaxMaxAdvertiseInterval : cur_drp->dr_life;
344 1.1 thorpej del_redirects(bad_gate, now.tv_sec-sec);
345 1.1 thorpej
346 1.1 thorpej rdisc_sol();
347 1.1 thorpej
348 1.1 thorpej rdisc_sort();
349 1.1 thorpej }
350 1.1 thorpej
351 1.1 thorpej
352 1.1 thorpej /* Zap all routes discovered via an interface that has gone bad
353 1.1 thorpej * This should only be called when !(ifp->int_state & IS_ALIAS)
354 1.1 thorpej */
355 1.1 thorpej void
356 1.1 thorpej if_bad_rdisc(struct interface *ifp)
357 1.1 thorpej {
358 1.1 thorpej struct dr *drp;
359 1.1 thorpej
360 1.1 thorpej for (drp = drs; drp < &drs[MAX_ADS]; drp++) {
361 1.1 thorpej if (drp->dr_ifp != ifp)
362 1.1 thorpej continue;
363 1.1 thorpej drp->dr_recv_pref = 0;
364 1.1 thorpej drp->dr_life = 0;
365 1.1 thorpej }
366 1.1 thorpej
367 1.1 thorpej rdisc_sort();
368 1.1 thorpej }
369 1.1 thorpej
370 1.1 thorpej
371 1.1 thorpej /* mark an interface ok for router discovering.
372 1.1 thorpej */
373 1.1 thorpej void
374 1.1 thorpej if_ok_rdisc(struct interface *ifp)
375 1.1 thorpej {
376 1.1 thorpej set_rdisc_mg(ifp, 1);
377 1.1 thorpej
378 1.1 thorpej ifp->int_rdisc_cnt = 0;
379 1.1 thorpej ifp->int_rdisc_timer.tv_sec = now.tv_sec + (supplier
380 1.1 thorpej ? MIN_WAITTIME
381 1.1 thorpej : MAX_SOLICITATION_DELAY);
382 1.1 thorpej if (timercmp(&rdisc_timer, &ifp->int_rdisc_timer, >))
383 1.1 thorpej rdisc_timer = ifp->int_rdisc_timer;
384 1.1 thorpej }
385 1.1 thorpej
386 1.1 thorpej
387 1.1 thorpej /* get rid of a dead discovered router
388 1.1 thorpej */
389 1.1 thorpej static void
390 1.1 thorpej del_rdisc(struct dr *drp)
391 1.1 thorpej {
392 1.1 thorpej struct interface *ifp;
393 1.1 thorpej int i;
394 1.1 thorpej
395 1.1 thorpej
396 1.1 thorpej del_redirects(drp->dr_gate, 0);
397 1.1 thorpej drp->dr_ts = 0;
398 1.1 thorpej drp->dr_life = 0;
399 1.1 thorpej
400 1.1 thorpej
401 1.1 thorpej /* Count the other discovered routes on the interface.
402 1.1 thorpej */
403 1.1 thorpej i = 0;
404 1.1 thorpej ifp = drp->dr_ifp;
405 1.1 thorpej for (drp = drs; drp < &drs[MAX_ADS]; drp++) {
406 1.1 thorpej if (drp->dr_ts != 0
407 1.1 thorpej && drp->dr_ifp == ifp)
408 1.1 thorpej i++;
409 1.1 thorpej }
410 1.1 thorpej
411 1.1 thorpej /* If that was the last good discovered router on the interface,
412 1.1 thorpej * then solicit a new one.
413 1.1 thorpej * This is contrary to RFC 1256, but defends against black holes.
414 1.1 thorpej */
415 1.1 thorpej if (i == 0
416 1.1 thorpej && ifp->int_rdisc_cnt >= MAX_SOLICITATIONS) {
417 1.5 christos trace_act("discovered route is bad--re-solicit routers via %s",
418 1.5 christos ifp->int_name);
419 1.1 thorpej ifp->int_rdisc_cnt = 0;
420 1.1 thorpej ifp->int_rdisc_timer.tv_sec = 0;
421 1.1 thorpej rdisc_sol();
422 1.1 thorpej }
423 1.1 thorpej }
424 1.1 thorpej
425 1.1 thorpej
426 1.1 thorpej /* Find the best discovered route,
427 1.1 thorpej * and discard stale routers.
428 1.1 thorpej */
429 1.1 thorpej static void
430 1.1 thorpej rdisc_sort(void)
431 1.1 thorpej {
432 1.1 thorpej struct dr *drp, *new_drp;
433 1.1 thorpej struct rt_entry *rt;
434 1.1 thorpej struct interface *ifp;
435 1.1 thorpej u_int new_st;
436 1.1 thorpej n_long new_pref;
437 1.1 thorpej
438 1.1 thorpej
439 1.1 thorpej /* Find the best discovered route.
440 1.1 thorpej */
441 1.1 thorpej new_drp = 0;
442 1.6 lukem new_st = 0;
443 1.6 lukem new_pref = 0;
444 1.1 thorpej for (drp = drs; drp < &drs[MAX_ADS]; drp++) {
445 1.1 thorpej if (drp->dr_ts == 0)
446 1.1 thorpej continue;
447 1.1 thorpej ifp = drp->dr_ifp;
448 1.1 thorpej
449 1.1 thorpej /* Get rid of expired discovered routers.
450 1.1 thorpej */
451 1.1 thorpej if (drp->dr_ts + drp->dr_life <= now.tv_sec) {
452 1.1 thorpej del_rdisc(drp);
453 1.1 thorpej continue;
454 1.1 thorpej }
455 1.1 thorpej
456 1.1 thorpej LIM_SEC(rdisc_timer, drp->dr_ts+drp->dr_life+1);
457 1.1 thorpej
458 1.1 thorpej /* Update preference with possibly changed interface
459 1.1 thorpej * metric.
460 1.1 thorpej */
461 1.1 thorpej drp->dr_pref = PREF(drp->dr_recv_pref, ifp);
462 1.1 thorpej
463 1.1 thorpej /* Prefer the current route to prevent thrashing.
464 1.1 thorpej * Prefer shorter lifetimes to speed the detection of
465 1.1 thorpej * bad routers.
466 1.1 thorpej * Avoid sick interfaces.
467 1.1 thorpej */
468 1.1 thorpej if (new_drp == 0
469 1.1 thorpej || (!((new_st ^ drp->dr_ifp->int_state) & IS_SICK)
470 1.1 thorpej && (new_pref < drp->dr_pref
471 1.1 thorpej || (new_pref == drp->dr_pref
472 1.1 thorpej && (drp == cur_drp
473 1.1 thorpej || (new_drp != cur_drp
474 1.1 thorpej && new_drp->dr_life > drp->dr_life)))))
475 1.1 thorpej || ((new_st & IS_SICK)
476 1.1 thorpej && !(drp->dr_ifp->int_state & IS_SICK))) {
477 1.1 thorpej new_drp = drp;
478 1.1 thorpej new_st = drp->dr_ifp->int_state;
479 1.1 thorpej new_pref = drp->dr_pref;
480 1.1 thorpej }
481 1.1 thorpej }
482 1.1 thorpej
483 1.1 thorpej /* switch to a better default route
484 1.1 thorpej */
485 1.1 thorpej if (new_drp != cur_drp) {
486 1.1 thorpej rt = rtget(RIP_DEFAULT, 0);
487 1.1 thorpej
488 1.1 thorpej /* Stop using discovered routes if they are all bad
489 1.1 thorpej */
490 1.1 thorpej if (new_drp == 0) {
491 1.5 christos trace_act("turn off Router Discovery client");
492 1.1 thorpej rdisc_ok = 0;
493 1.1 thorpej
494 1.1 thorpej if (rt != 0
495 1.1 thorpej && (rt->rt_state & RS_RDISC)) {
496 1.1 thorpej rtchange(rt, rt->rt_state & ~RS_RDISC,
497 1.1 thorpej rt->rt_gate, rt->rt_router,
498 1.1 thorpej HOPCNT_INFINITY, 0, rt->rt_ifp,
499 1.1 thorpej now.tv_sec - GARBAGE_TIME, 0);
500 1.1 thorpej rtswitch(rt, 0);
501 1.1 thorpej }
502 1.1 thorpej
503 1.1 thorpej /* turn on RIP if permitted */
504 1.1 thorpej rip_on(0);
505 1.1 thorpej
506 1.1 thorpej } else {
507 1.1 thorpej if (cur_drp == 0) {
508 1.1 thorpej trace_act("turn on Router Discovery client"
509 1.5 christos " using %s via %s",
510 1.1 thorpej naddr_ntoa(new_drp->dr_gate),
511 1.1 thorpej new_drp->dr_ifp->int_name);
512 1.1 thorpej
513 1.1 thorpej rdisc_ok = 1;
514 1.1 thorpej
515 1.1 thorpej } else {
516 1.1 thorpej trace_act("switch Router Discovery from"
517 1.5 christos " %s via %s to %s via %s",
518 1.1 thorpej naddr_ntoa(cur_drp->dr_gate),
519 1.1 thorpej cur_drp->dr_ifp->int_name,
520 1.1 thorpej naddr_ntoa(new_drp->dr_gate),
521 1.1 thorpej new_drp->dr_ifp->int_name);
522 1.1 thorpej }
523 1.1 thorpej
524 1.1 thorpej if (rt != 0) {
525 1.1 thorpej rtchange(rt, rt->rt_state | RS_RDISC,
526 1.1 thorpej new_drp->dr_gate, new_drp->dr_gate,
527 1.1 thorpej 0,0, new_drp->dr_ifp,
528 1.1 thorpej now.tv_sec, 0);
529 1.1 thorpej } else {
530 1.1 thorpej rtadd(RIP_DEFAULT, 0,
531 1.1 thorpej new_drp->dr_gate, new_drp->dr_gate,
532 1.5 christos HOPCNT_INFINITY-1, 0,
533 1.5 christos RS_RDISC, new_drp->dr_ifp);
534 1.1 thorpej }
535 1.1 thorpej
536 1.1 thorpej /* Now turn off RIP and delete RIP routes,
537 1.1 thorpej * which might otherwise include the default
538 1.1 thorpej * we just modified.
539 1.1 thorpej */
540 1.1 thorpej rip_off();
541 1.1 thorpej }
542 1.1 thorpej
543 1.1 thorpej cur_drp = new_drp;
544 1.1 thorpej }
545 1.1 thorpej }
546 1.1 thorpej
547 1.1 thorpej
548 1.1 thorpej /* handle a single address in an advertisement
549 1.1 thorpej */
550 1.1 thorpej static void
551 1.1 thorpej parse_ad(naddr from,
552 1.1 thorpej naddr gate,
553 1.1 thorpej n_long pref,
554 1.1 thorpej u_short life,
555 1.1 thorpej struct interface *ifp)
556 1.1 thorpej {
557 1.5 christos static struct msg_limit bad_gate;
558 1.1 thorpej struct dr *drp, *new_drp;
559 1.1 thorpej
560 1.1 thorpej
561 1.1 thorpej if (gate == RIP_DEFAULT
562 1.1 thorpej || !check_dst(gate)) {
563 1.5 christos msglim(&bad_gate, from,"router %s advertising bad gateway %s",
564 1.5 christos naddr_ntoa(from),
565 1.5 christos naddr_ntoa(gate));
566 1.1 thorpej return;
567 1.1 thorpej }
568 1.1 thorpej
569 1.1 thorpej /* ignore pointers to ourself and routes via unreachable networks
570 1.1 thorpej */
571 1.1 thorpej if (ifwithaddr(gate, 1, 0) != 0) {
572 1.5 christos trace_pkt(" discard Router Discovery Ad pointing at us");
573 1.1 thorpej return;
574 1.1 thorpej }
575 1.1 thorpej if (!on_net(gate, ifp->int_net, ifp->int_mask)) {
576 1.5 christos trace_pkt(" discard Router Discovery Ad"
577 1.5 christos " toward unreachable net");
578 1.1 thorpej return;
579 1.1 thorpej }
580 1.1 thorpej
581 1.1 thorpej /* Convert preference to an unsigned value
582 1.1 thorpej * and later bias it by the metric of the interface.
583 1.1 thorpej */
584 1.1 thorpej pref = ntohl(pref) ^ MIN_PreferenceLevel;
585 1.4 christos
586 1.1 thorpej if (pref == 0 || life == 0) {
587 1.1 thorpej pref = 0;
588 1.1 thorpej life = 0;
589 1.1 thorpej }
590 1.1 thorpej
591 1.1 thorpej for (new_drp = 0, drp = drs; drp < &drs[MAX_ADS]; drp++) {
592 1.1 thorpej /* accept new info for a familiar entry
593 1.1 thorpej */
594 1.1 thorpej if (drp->dr_gate == gate) {
595 1.1 thorpej new_drp = drp;
596 1.1 thorpej break;
597 1.1 thorpej }
598 1.1 thorpej
599 1.1 thorpej if (life == 0)
600 1.1 thorpej continue; /* do not worry about dead ads */
601 1.1 thorpej
602 1.1 thorpej if (drp->dr_ts == 0) {
603 1.1 thorpej new_drp = drp; /* use unused entry */
604 1.1 thorpej
605 1.1 thorpej } else if (new_drp == 0) {
606 1.1 thorpej /* look for an entry worse than the new one to
607 1.1 thorpej * reuse.
608 1.1 thorpej */
609 1.1 thorpej if ((!(ifp->int_state & IS_SICK)
610 1.1 thorpej && (drp->dr_ifp->int_state & IS_SICK))
611 1.1 thorpej || (pref > drp->dr_pref
612 1.1 thorpej && !((ifp->int_state ^ drp->dr_ifp->int_state)
613 1.1 thorpej & IS_SICK)))
614 1.1 thorpej new_drp = drp;
615 1.1 thorpej
616 1.1 thorpej } else if (new_drp->dr_ts != 0) {
617 1.1 thorpej /* look for the least valueable entry to reuse
618 1.1 thorpej */
619 1.1 thorpej if ((!(new_drp->dr_ifp->int_state & IS_SICK)
620 1.1 thorpej && (drp->dr_ifp->int_state & IS_SICK))
621 1.1 thorpej || (new_drp->dr_pref > drp->dr_pref
622 1.1 thorpej && !((new_drp->dr_ifp->int_state
623 1.1 thorpej ^ drp->dr_ifp->int_state)
624 1.1 thorpej & IS_SICK)))
625 1.1 thorpej new_drp = drp;
626 1.1 thorpej }
627 1.1 thorpej }
628 1.1 thorpej
629 1.1 thorpej /* forget it if all of the current entries are better */
630 1.1 thorpej if (new_drp == 0)
631 1.1 thorpej return;
632 1.1 thorpej
633 1.1 thorpej new_drp->dr_ifp = ifp;
634 1.1 thorpej new_drp->dr_gate = gate;
635 1.1 thorpej new_drp->dr_ts = now.tv_sec;
636 1.1 thorpej new_drp->dr_life = ntohs(life);
637 1.1 thorpej new_drp->dr_recv_pref = pref;
638 1.1 thorpej /* bias functional preference by metric of the interface */
639 1.1 thorpej new_drp->dr_pref = PREF(pref,ifp);
640 1.1 thorpej
641 1.1 thorpej /* after hearing a good advertisement, stop asking
642 1.1 thorpej */
643 1.1 thorpej if (!(ifp->int_state & IS_SICK))
644 1.1 thorpej ifp->int_rdisc_cnt = MAX_SOLICITATIONS;
645 1.1 thorpej }
646 1.1 thorpej
647 1.1 thorpej
648 1.1 thorpej /* Compute the IP checksum
649 1.1 thorpej * This assumes the packet is less than 32K long.
650 1.1 thorpej */
651 1.1 thorpej static u_short
652 1.1 thorpej in_cksum(u_short *p,
653 1.1 thorpej u_int len)
654 1.1 thorpej {
655 1.1 thorpej u_int sum = 0;
656 1.1 thorpej int nwords = len >> 1;
657 1.1 thorpej
658 1.1 thorpej while (nwords-- != 0)
659 1.1 thorpej sum += *p++;
660 1.1 thorpej
661 1.1 thorpej if (len & 1)
662 1.1 thorpej sum += *(u_char *)p;
663 1.1 thorpej
664 1.1 thorpej /* end-around-carry */
665 1.1 thorpej sum = (sum >> 16) + (sum & 0xffff);
666 1.1 thorpej sum += (sum >> 16);
667 1.1 thorpej return (~sum);
668 1.1 thorpej }
669 1.1 thorpej
670 1.1 thorpej
671 1.1 thorpej /* Send a router discovery advertisement or solicitation ICMP packet.
672 1.1 thorpej */
673 1.1 thorpej static void
674 1.1 thorpej send_rdisc(union ad_u *p,
675 1.1 thorpej int p_size,
676 1.1 thorpej struct interface *ifp,
677 1.1 thorpej naddr dst, /* 0 or unicast destination */
678 1.1 thorpej int type) /* 0=unicast, 1=bcast, 2=mcast */
679 1.1 thorpej {
680 1.1 thorpej struct sockaddr_in sin;
681 1.1 thorpej int flags;
682 1.1 thorpej char *msg;
683 1.1 thorpej naddr tgt_mcast;
684 1.1 thorpej
685 1.1 thorpej
686 1.6 lukem memset(&sin, 0, sizeof(sin));
687 1.4 christos sin.sin_addr.s_addr = dst;
688 1.3 mycroft sin.sin_family = AF_INET;
689 1.4 christos #ifdef _HAVE_SIN_LEN
690 1.3 mycroft sin.sin_len = sizeof(sin);
691 1.4 christos #endif
692 1.1 thorpej flags = MSG_DONTROUTE;
693 1.1 thorpej
694 1.1 thorpej switch (type) {
695 1.1 thorpej case 0: /* unicast */
696 1.5 christos default:
697 1.1 thorpej msg = "Send";
698 1.1 thorpej break;
699 1.1 thorpej
700 1.1 thorpej case 1: /* broadcast */
701 1.1 thorpej if (ifp->int_if_flags & IFF_POINTOPOINT) {
702 1.1 thorpej msg = "Send pt-to-pt";
703 1.1 thorpej sin.sin_addr.s_addr = ifp->int_dstaddr;
704 1.1 thorpej } else {
705 1.1 thorpej msg = "Send broadcast";
706 1.1 thorpej sin.sin_addr.s_addr = ifp->int_brdaddr;
707 1.1 thorpej }
708 1.1 thorpej break;
709 1.1 thorpej
710 1.1 thorpej case 2: /* multicast */
711 1.1 thorpej msg = "Send multicast";
712 1.1 thorpej if (ifp->int_state & IS_DUP) {
713 1.1 thorpej trace_act("abort multicast output via %s"
714 1.5 christos " with duplicate address",
715 1.1 thorpej ifp->int_name);
716 1.1 thorpej return;
717 1.1 thorpej }
718 1.1 thorpej if (rdisc_sock_mcast != ifp) {
719 1.1 thorpej /* select the right interface. */
720 1.1 thorpej #ifdef MCAST_PPP_BUG
721 1.1 thorpej /* Do not specifiy the primary interface explicitly
722 1.1 thorpej * if we have the multicast point-to-point kernel
723 1.1 thorpej * bug, since the kernel will do the wrong thing
724 1.1 thorpej * if the local address of a point-to-point link
725 1.1 thorpej * is the same as the address of an ordinary
726 1.1 thorpej * interface.
727 1.1 thorpej */
728 1.1 thorpej if (ifp->int_addr == myaddr) {
729 1.1 thorpej tgt_mcast = 0;
730 1.1 thorpej } else
731 1.1 thorpej #endif
732 1.1 thorpej tgt_mcast = ifp->int_addr;
733 1.1 thorpej if (0 > setsockopt(rdisc_sock,
734 1.1 thorpej IPPROTO_IP, IP_MULTICAST_IF,
735 1.1 thorpej &tgt_mcast, sizeof(tgt_mcast))) {
736 1.1 thorpej LOGERR("setsockopt(rdisc_sock,"
737 1.1 thorpej "IP_MULTICAST_IF)");
738 1.1 thorpej rdisc_sock_mcast = 0;
739 1.1 thorpej return;
740 1.1 thorpej }
741 1.1 thorpej rdisc_sock_mcast = ifp;
742 1.1 thorpej }
743 1.1 thorpej flags = 0;
744 1.1 thorpej break;
745 1.1 thorpej }
746 1.4 christos
747 1.4 christos if (rdisc_sock < 0)
748 1.4 christos get_rdisc_sock();
749 1.1 thorpej
750 1.1 thorpej trace_rdisc(msg, ifp->int_addr, sin.sin_addr.s_addr, ifp,
751 1.1 thorpej p, p_size);
752 1.1 thorpej
753 1.1 thorpej if (0 > sendto(rdisc_sock, p, p_size, flags,
754 1.1 thorpej (struct sockaddr *)&sin, sizeof(sin))) {
755 1.1 thorpej if (ifp == 0 || !(ifp->int_state & IS_BROKE))
756 1.1 thorpej msglog("sendto(%s%s%s): %s",
757 1.1 thorpej ifp != 0 ? ifp->int_name : "",
758 1.1 thorpej ifp != 0 ? ", " : "",
759 1.1 thorpej inet_ntoa(sin.sin_addr),
760 1.1 thorpej strerror(errno));
761 1.1 thorpej if (ifp != 0)
762 1.1 thorpej if_sick(ifp);
763 1.1 thorpej }
764 1.1 thorpej }
765 1.1 thorpej
766 1.1 thorpej
767 1.1 thorpej /* Send an advertisement
768 1.1 thorpej */
769 1.1 thorpej static void
770 1.1 thorpej send_adv(struct interface *ifp,
771 1.1 thorpej naddr dst, /* 0 or unicast destination */
772 1.1 thorpej int type) /* 0=unicast, 1=bcast, 2=mcast */
773 1.1 thorpej {
774 1.1 thorpej union ad_u u;
775 1.1 thorpej n_long pref;
776 1.1 thorpej
777 1.1 thorpej
778 1.6 lukem memset(&u, 0, sizeof(u.ad));
779 1.1 thorpej
780 1.1 thorpej u.ad.icmp_type = ICMP_ROUTERADVERT;
781 1.1 thorpej u.ad.icmp_ad_num = 1;
782 1.1 thorpej u.ad.icmp_ad_asize = sizeof(u.ad.icmp_ad_info[0])/4;
783 1.1 thorpej
784 1.1 thorpej u.ad.icmp_ad_life = stopint ? 0 : htons(ifp->int_rdisc_int*3);
785 1.1 thorpej pref = ifp->int_rdisc_pref ^ MIN_PreferenceLevel;
786 1.1 thorpej pref = PREF(pref, ifp) ^ MIN_PreferenceLevel;
787 1.1 thorpej u.ad.icmp_ad_info[0].icmp_ad_pref = htonl(pref);
788 1.1 thorpej
789 1.1 thorpej u.ad.icmp_ad_info[0].icmp_ad_addr = ifp->int_addr;
790 1.1 thorpej
791 1.1 thorpej u.ad.icmp_cksum = in_cksum((u_short*)&u.ad, sizeof(u.ad));
792 1.1 thorpej
793 1.1 thorpej send_rdisc(&u, sizeof(u.ad), ifp, dst, type);
794 1.1 thorpej }
795 1.1 thorpej
796 1.1 thorpej
797 1.1 thorpej /* Advertise for Router Discovery
798 1.1 thorpej */
799 1.1 thorpej void
800 1.1 thorpej rdisc_adv(void)
801 1.1 thorpej {
802 1.1 thorpej struct interface *ifp;
803 1.1 thorpej
804 1.5 christos if (!supplier)
805 1.5 christos return;
806 1.1 thorpej
807 1.1 thorpej rdisc_timer.tv_sec = now.tv_sec + NEVER;
808 1.1 thorpej
809 1.1 thorpej for (ifp = ifnet; ifp; ifp = ifp->int_next) {
810 1.5 christos if (0 != (ifp->int_state & (IS_NO_ADV_OUT | IS_BROKE)))
811 1.1 thorpej continue;
812 1.1 thorpej
813 1.1 thorpej if (!timercmp(&ifp->int_rdisc_timer, &now, >)
814 1.1 thorpej || stopint) {
815 1.1 thorpej send_adv(ifp, htonl(INADDR_ALLHOSTS_GROUP),
816 1.1 thorpej (ifp->int_state&IS_BCAST_RDISC) ? 1 : 2);
817 1.1 thorpej ifp->int_rdisc_cnt++;
818 1.1 thorpej
819 1.1 thorpej intvl_random(&ifp->int_rdisc_timer,
820 1.1 thorpej (ifp->int_rdisc_int*3)/4,
821 1.1 thorpej ifp->int_rdisc_int);
822 1.1 thorpej if (ifp->int_rdisc_cnt < MAX_INITIAL_ADVERTS
823 1.1 thorpej && (ifp->int_rdisc_timer.tv_sec
824 1.1 thorpej > MAX_INITIAL_ADVERT_INTERVAL)) {
825 1.1 thorpej ifp->int_rdisc_timer.tv_sec
826 1.1 thorpej = MAX_INITIAL_ADVERT_INTERVAL;
827 1.1 thorpej }
828 1.1 thorpej timevaladd(&ifp->int_rdisc_timer, &now);
829 1.1 thorpej }
830 1.1 thorpej
831 1.1 thorpej if (timercmp(&rdisc_timer, &ifp->int_rdisc_timer, >))
832 1.1 thorpej rdisc_timer = ifp->int_rdisc_timer;
833 1.1 thorpej }
834 1.1 thorpej }
835 1.1 thorpej
836 1.1 thorpej
837 1.1 thorpej /* Solicit for Router Discovery
838 1.1 thorpej */
839 1.1 thorpej void
840 1.1 thorpej rdisc_sol(void)
841 1.1 thorpej {
842 1.1 thorpej struct interface *ifp;
843 1.1 thorpej union ad_u u;
844 1.1 thorpej
845 1.1 thorpej
846 1.5 christos if (supplier)
847 1.5 christos return;
848 1.5 christos
849 1.1 thorpej rdisc_timer.tv_sec = now.tv_sec + NEVER;
850 1.1 thorpej
851 1.1 thorpej for (ifp = ifnet; ifp; ifp = ifp->int_next) {
852 1.5 christos if (0 != (ifp->int_state & (IS_NO_SOL_OUT | IS_BROKE))
853 1.1 thorpej || ifp->int_rdisc_cnt >= MAX_SOLICITATIONS)
854 1.1 thorpej continue;
855 1.1 thorpej
856 1.1 thorpej if (!timercmp(&ifp->int_rdisc_timer, &now, >)) {
857 1.6 lukem memset(&u, 0, sizeof(u.so));
858 1.1 thorpej u.so.icmp_type = ICMP_ROUTERSOLICIT;
859 1.1 thorpej u.so.icmp_cksum = in_cksum((u_short*)&u.so,
860 1.1 thorpej sizeof(u.so));
861 1.1 thorpej send_rdisc(&u, sizeof(u.so), ifp,
862 1.1 thorpej htonl(INADDR_ALLROUTERS_GROUP),
863 1.1 thorpej ((ifp->int_state&IS_BCAST_RDISC) ? 1 : 2));
864 1.1 thorpej
865 1.1 thorpej if (++ifp->int_rdisc_cnt >= MAX_SOLICITATIONS)
866 1.1 thorpej continue;
867 1.1 thorpej
868 1.1 thorpej ifp->int_rdisc_timer.tv_sec = SOLICITATION_INTERVAL;
869 1.1 thorpej ifp->int_rdisc_timer.tv_usec = 0;
870 1.1 thorpej timevaladd(&ifp->int_rdisc_timer, &now);
871 1.1 thorpej }
872 1.1 thorpej
873 1.1 thorpej if (timercmp(&rdisc_timer, &ifp->int_rdisc_timer, >))
874 1.1 thorpej rdisc_timer = ifp->int_rdisc_timer;
875 1.1 thorpej }
876 1.1 thorpej }
877 1.1 thorpej
878 1.1 thorpej
879 1.1 thorpej /* check the IP header of a possible Router Discovery ICMP packet */
880 1.1 thorpej static struct interface * /* 0 if bad */
881 1.1 thorpej ck_icmp(char *act,
882 1.1 thorpej naddr from,
883 1.5 christos struct interface *ifp,
884 1.1 thorpej naddr to,
885 1.1 thorpej union ad_u *p,
886 1.1 thorpej u_int len)
887 1.1 thorpej {
888 1.1 thorpej char *type;
889 1.1 thorpej
890 1.1 thorpej
891 1.1 thorpej if (p->icmp.icmp_type == ICMP_ROUTERADVERT) {
892 1.1 thorpej type = "advertisement";
893 1.1 thorpej } else if (p->icmp.icmp_type == ICMP_ROUTERSOLICIT) {
894 1.1 thorpej type = "solicitation";
895 1.1 thorpej } else {
896 1.1 thorpej return 0;
897 1.1 thorpej }
898 1.1 thorpej
899 1.1 thorpej if (p->icmp.icmp_code != 0) {
900 1.5 christos trace_pkt("unrecognized ICMP Router %s code=%d from %s to %s",
901 1.1 thorpej type, p->icmp.icmp_code,
902 1.1 thorpej naddr_ntoa(from), naddr_ntoa(to));
903 1.1 thorpej return 0;
904 1.1 thorpej }
905 1.1 thorpej
906 1.1 thorpej trace_rdisc(act, from, to, ifp, p, len);
907 1.1 thorpej
908 1.1 thorpej if (ifp == 0)
909 1.1 thorpej trace_pkt("unknown interface for router-discovery %s"
910 1.1 thorpej " from %s to %s",
911 1.1 thorpej type, naddr_ntoa(from), naddr_ntoa(to));
912 1.1 thorpej
913 1.1 thorpej return ifp;
914 1.1 thorpej }
915 1.1 thorpej
916 1.1 thorpej
917 1.1 thorpej /* read packets from the router discovery socket
918 1.1 thorpej */
919 1.1 thorpej void
920 1.1 thorpej read_d(void)
921 1.1 thorpej {
922 1.5 christos static struct msg_limit bad_asize, bad_len;
923 1.5 christos #ifdef USE_PASSIFNAME
924 1.5 christos static struct msg_limit bad_name;
925 1.5 christos #endif
926 1.1 thorpej struct sockaddr_in from;
927 1.1 thorpej int n, fromlen, cc, hlen;
928 1.5 christos struct {
929 1.5 christos #ifdef USE_PASSIFNAME
930 1.5 christos char ifname[IFNAMSIZ];
931 1.5 christos #endif
932 1.5 christos union {
933 1.5 christos struct ip ip;
934 1.5 christos u_short s[512/2];
935 1.5 christos u_char b[512];
936 1.5 christos } pkt;
937 1.5 christos } buf;
938 1.1 thorpej union ad_u *p;
939 1.1 thorpej n_long *wp;
940 1.1 thorpej struct interface *ifp;
941 1.1 thorpej
942 1.1 thorpej
943 1.1 thorpej for (;;) {
944 1.1 thorpej fromlen = sizeof(from);
945 1.5 christos cc = recvfrom(rdisc_sock, &buf, sizeof(buf), 0,
946 1.1 thorpej (struct sockaddr*)&from,
947 1.1 thorpej &fromlen);
948 1.1 thorpej if (cc <= 0) {
949 1.1 thorpej if (cc < 0 && errno != EWOULDBLOCK)
950 1.1 thorpej LOGERR("recvfrom(rdisc_sock)");
951 1.1 thorpej break;
952 1.1 thorpej }
953 1.1 thorpej if (fromlen != sizeof(struct sockaddr_in))
954 1.1 thorpej logbad(1,"impossible recvfrom(rdisc_sock) fromlen=%d",
955 1.1 thorpej fromlen);
956 1.5 christos #ifdef USE_PASSIFNAME
957 1.5 christos if ((cc -= sizeof(buf.ifname)) < 0)
958 1.5 christos logbad(0,"missing USE_PASSIFNAME; only %d bytes",
959 1.5 christos cc+sizeof(buf.ifname));
960 1.5 christos #endif
961 1.1 thorpej
962 1.5 christos hlen = buf.pkt.ip.ip_hl << 2;
963 1.1 thorpej if (cc < hlen + ICMP_MINLEN)
964 1.1 thorpej continue;
965 1.5 christos p = (union ad_u *)&buf.pkt.b[hlen];
966 1.1 thorpej cc -= hlen;
967 1.1 thorpej
968 1.5 christos #ifdef USE_PASSIFNAME
969 1.5 christos ifp = ifwithname(buf.ifname, 0);
970 1.5 christos if (ifp == 0)
971 1.5 christos msglim(&bad_name, from.sin_addr.s_addr,
972 1.5 christos "impossible rdisc if_ name %.*s",
973 1.5 christos IFNAMSIZ, buf.ifname);
974 1.5 christos #else
975 1.5 christos /* If we could tell the interface on which a packet from
976 1.5 christos * address 0 arrived, we could deal with such solicitations.
977 1.5 christos */
978 1.5 christos ifp = ((from.sin_addr.s_addr == 0)
979 1.5 christos ? 0 : iflookup(from.sin_addr.s_addr));
980 1.5 christos #endif
981 1.5 christos ifp = ck_icmp("Recv", from.sin_addr.s_addr, ifp,
982 1.5 christos buf.pkt.ip.ip_dst.s_addr, p, cc);
983 1.1 thorpej if (ifp == 0)
984 1.1 thorpej continue;
985 1.1 thorpej if (ifwithaddr(from.sin_addr.s_addr, 0, 0)) {
986 1.5 christos trace_pkt(" "
987 1.5 christos "discard our own Router Discovery message");
988 1.1 thorpej continue;
989 1.1 thorpej }
990 1.1 thorpej
991 1.1 thorpej switch (p->icmp.icmp_type) {
992 1.1 thorpej case ICMP_ROUTERADVERT:
993 1.1 thorpej if (p->ad.icmp_ad_asize*4
994 1.1 thorpej < sizeof(p->ad.icmp_ad_info[0])) {
995 1.5 christos msglim(&bad_asize, from.sin_addr.s_addr,
996 1.5 christos "intolerable rdisc address size=%d",
997 1.5 christos p->ad.icmp_ad_asize);
998 1.1 thorpej continue;
999 1.1 thorpej }
1000 1.1 thorpej if (p->ad.icmp_ad_num == 0) {
1001 1.5 christos trace_pkt(" empty?");
1002 1.1 thorpej continue;
1003 1.1 thorpej }
1004 1.1 thorpej if (cc != (sizeof(p->ad) - sizeof(p->ad.icmp_ad_info)
1005 1.1 thorpej + (p->ad.icmp_ad_num
1006 1.1 thorpej * sizeof(p->ad.icmp_ad_info[0])))) {
1007 1.5 christos msglim(&bad_len, from.sin_addr.s_addr,
1008 1.5 christos "rdisc length %d does not match ad_num"
1009 1.5 christos " %d", cc, p->ad.icmp_ad_num);
1010 1.1 thorpej continue;
1011 1.1 thorpej }
1012 1.1 thorpej if (supplier)
1013 1.1 thorpej continue;
1014 1.1 thorpej if (ifp->int_state & IS_NO_ADV_IN)
1015 1.1 thorpej continue;
1016 1.1 thorpej
1017 1.1 thorpej wp = &p->ad.icmp_ad_info[0].icmp_ad_addr;
1018 1.1 thorpej for (n = 0; n < p->ad.icmp_ad_num; n++) {
1019 1.1 thorpej parse_ad(from.sin_addr.s_addr,
1020 1.1 thorpej wp[0], wp[1],
1021 1.1 thorpej ntohs(p->ad.icmp_ad_life),
1022 1.1 thorpej ifp);
1023 1.1 thorpej wp += p->ad.icmp_ad_asize;
1024 1.1 thorpej }
1025 1.1 thorpej break;
1026 1.1 thorpej
1027 1.1 thorpej
1028 1.1 thorpej case ICMP_ROUTERSOLICIT:
1029 1.1 thorpej if (!supplier)
1030 1.1 thorpej continue;
1031 1.1 thorpej if (ifp->int_state & IS_NO_ADV_OUT)
1032 1.1 thorpej continue;
1033 1.1 thorpej
1034 1.1 thorpej /* XXX
1035 1.1 thorpej * We should handle messages from address 0.
1036 1.1 thorpej */
1037 1.1 thorpej
1038 1.1 thorpej /* Respond with a point-to-point advertisement */
1039 1.1 thorpej send_adv(ifp, from.sin_addr.s_addr, 0);
1040 1.1 thorpej break;
1041 1.1 thorpej }
1042 1.1 thorpej }
1043 1.1 thorpej
1044 1.1 thorpej rdisc_sort();
1045 1.1 thorpej }
1046