1 /* $OpenBSD: dvmrpe.c,v 1.24 2024/04/23 13:34:51 jsg Exp $ */
2
3 /*
4 * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
5 * Copyright (c) 2004, 2005, 2006 Esben Norby <norby@openbsd.org>
6 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
7 *
8 * Permission to use, copy, modify, and distribute this software for any
9 * purpose with or without fee is hereby granted, provided that the above
10 * copyright notice and this permission notice appear in all copies.
11 *
12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 */
20
21 #include <sys/types.h>
22 #include <sys/socket.h>
23 #include <sys/queue.h>
24 #include <netinet/in.h>
25 #include <arpa/inet.h>
26 #include <net/if_types.h>
27 #include <stdlib.h>
28 #include <signal.h>
29 #include <string.h>
30 #include <fcntl.h>
31 #include <pwd.h>
32 #include <unistd.h>
33 #include <event.h>
34 #include <err.h>
35 #include <errno.h>
36 #include <stdio.h>
37
38 #include "igmp.h"
39 #include "dvmrp.h"
40 #include "dvmrpd.h"
41 #include "dvmrpe.h"
42 #include "control.h"
43 #include "log.h"
44
45 void dvmrpe_sig_handler(int, short, void *);
46 __dead void dvmrpe_shutdown(void);
47
48 volatile sig_atomic_t dvmrpe_quit = 0;
49 struct dvmrpd_conf *deconf = NULL;
50 static struct imsgev *iev_main;
51 static struct imsgev *iev_rde;
52
53 void
dvmrpe_sig_handler(int sig,short event,void * bula)54 dvmrpe_sig_handler(int sig, short event, void *bula)
55 {
56 switch (sig) {
57 case SIGINT:
58 case SIGTERM:
59 dvmrpe_shutdown();
60 /* NOTREACHED */
61 default:
62 fatalx("unexpected signal");
63 }
64 }
65
66 /* dvmrp engine */
67 pid_t
dvmrpe(struct dvmrpd_conf * xconf,int pipe_parent2dvmrpe[2],int pipe_dvmrpe2rde[2],int pipe_parent2rde[2])68 dvmrpe(struct dvmrpd_conf *xconf, int pipe_parent2dvmrpe[2],
69 int pipe_dvmrpe2rde[2], int pipe_parent2rde[2])
70 {
71 struct iface *iface = NULL;
72 struct passwd *pw;
73 struct event ev_sigint, ev_sigterm;
74 pid_t pid;
75
76 switch (pid = fork()) {
77 case -1:
78 fatal("cannot fork");
79 case 0:
80 break;
81 default:
82
83 return (pid);
84 }
85
86 /* create the raw ip socket */
87 if ((xconf->dvmrp_socket = socket(AF_INET,
88 SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK,
89 IPPROTO_IGMP)) == -1)
90 fatal("error creating raw socket");
91
92 /* create dvmrpd control socket outside chroot */
93 if (control_init() == -1)
94 fatalx("control socket setup failed");
95
96 /* set some defaults */
97 if (if_set_mcast_ttl(xconf->dvmrp_socket,
98 IP_DEFAULT_MULTICAST_TTL) == -1)
99 fatal("if_set_mcast_ttl");
100
101 if (if_set_mcast_loop(xconf->dvmrp_socket) == -1)
102 fatal("if_set_mcast_loop");
103
104 if (if_set_tos(xconf->dvmrp_socket, IPTOS_PREC_INTERNETCONTROL) == -1)
105 fatal("if_set_tos");
106
107 if_set_recvbuf(xconf->dvmrp_socket);
108
109 deconf = xconf;
110
111 if ((pw = getpwnam(DVMRPD_USER)) == NULL)
112 fatal("getpwnam");
113
114 if (chroot(pw->pw_dir) == -1)
115 fatal("chroot");
116 if (chdir("/") == -1)
117 fatal("chdir(\"/\")");
118
119 setproctitle("dvmrp engine");
120 log_procname = "dvmrpe";
121
122 if (setgroups(1, &pw->pw_gid) ||
123 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
124 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
125 fatal("can't drop privileges");
126
127 event_init();
128 nbr_init(NBR_HASHSIZE);
129
130 /* setup signal handler */
131 signal_set(&ev_sigint, SIGINT, dvmrpe_sig_handler, NULL);
132 signal_set(&ev_sigterm, SIGTERM, dvmrpe_sig_handler, NULL);
133 signal_add(&ev_sigint, NULL);
134 signal_add(&ev_sigterm, NULL);
135 signal(SIGPIPE, SIG_IGN);
136
137 /* setup pipes */
138 close(pipe_parent2dvmrpe[0]);
139 close(pipe_dvmrpe2rde[1]);
140 close(pipe_parent2rde[0]);
141 close(pipe_parent2rde[1]);
142
143 if ((iev_rde = malloc(sizeof(struct imsgev))) == NULL ||
144 (iev_main = malloc(sizeof(struct imsgev))) == NULL)
145 fatal(NULL);
146 imsg_init(&iev_rde->ibuf, pipe_dvmrpe2rde[0]);
147 iev_rde->handler = dvmrpe_dispatch_rde;
148
149 imsg_init(&iev_main->ibuf, pipe_parent2dvmrpe[1]);
150 iev_main->handler = dvmrpe_dispatch_main;
151
152 /* setup event handler */
153 iev_rde->events = EV_READ;
154 event_set(&iev_rde->ev, iev_rde->ibuf.fd, iev_rde->events,
155 iev_rde->handler, iev_rde);
156 event_add(&iev_rde->ev, NULL);
157
158 iev_main->events = EV_READ;
159 event_set(&iev_main->ev, iev_main->ibuf.fd, iev_main->events,
160 iev_main->handler, iev_main);
161 event_add(&iev_main->ev, NULL);
162
163 event_set(&deconf->ev, deconf->dvmrp_socket, EV_READ|EV_PERSIST,
164 recv_packet, deconf);
165 event_add(&deconf->ev, NULL);
166
167 /* listen on dvmrpd control socket */
168 control_listen();
169
170 /* start interfaces */
171 LIST_FOREACH(iface, &deconf->iface_list, entry) {
172 if_init(xconf, iface);
173 if (if_fsm(iface, IF_EVT_UP)) {
174 log_debug("error starting interface %s", iface->name);
175 }
176 }
177
178 evtimer_set(&deconf->report_timer, report_timer, deconf);
179 start_report_timer();
180
181 event_dispatch();
182
183 dvmrpe_shutdown();
184 /* NOTREACHED */
185 return (0);
186 }
187
188 __dead void
dvmrpe_shutdown(void)189 dvmrpe_shutdown(void)
190 {
191 struct iface *iface;
192
193 /* close pipes */
194 msgbuf_write(&iev_rde->ibuf.w);
195 msgbuf_clear(&iev_rde->ibuf.w);
196 close(iev_rde->ibuf.fd);
197 msgbuf_write(&iev_main->ibuf.w);
198 msgbuf_clear(&iev_main->ibuf.w);
199 close(iev_main->ibuf.fd);
200
201 /* stop all interfaces and delete them */
202 LIST_FOREACH(iface, &deconf->iface_list, entry) {
203 if (if_fsm(iface, IF_EVT_DOWN)) {
204 log_debug("error stopping interface %s",
205 iface->name);
206 }
207 if_del(iface);
208 }
209
210 /* clean up */
211 free(iev_rde);
212 free(iev_main);
213
214 log_info("dvmrp engine exiting");
215 _exit(0);
216 }
217
218 int
dvmrpe_imsg_compose_parent(int type,pid_t pid,void * data,u_int16_t datalen)219 dvmrpe_imsg_compose_parent(int type, pid_t pid, void *data, u_int16_t datalen)
220 {
221 return (imsg_compose_event(iev_main, type, 0, pid, -1, data, datalen));
222 }
223
224 int
dvmrpe_imsg_compose_rde(int type,u_int32_t peerid,pid_t pid,void * data,u_int16_t datalen)225 dvmrpe_imsg_compose_rde(int type, u_int32_t peerid, pid_t pid,
226 void *data, u_int16_t datalen)
227 {
228 return (imsg_compose_event(iev_rde, type, peerid, pid,
229 -1, data, datalen));
230 }
231
232 void
dvmrpe_dispatch_main(int fd,short event,void * bula)233 dvmrpe_dispatch_main(int fd, short event, void *bula)
234 {
235 struct imsg imsg;
236 struct imsgev *iev = bula;
237 struct imsgbuf *ibuf = &iev->ibuf;
238 struct kif *kif;
239 struct iface *iface;
240 ssize_t n;
241 int shut = 0, link_ok;
242
243 if (event & EV_READ) {
244 if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
245 fatal("imsg_read error");
246 if (n == 0) /* connection closed */
247 shut = 1;
248 }
249 if (event & EV_WRITE) {
250 if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
251 fatal("msgbuf_write");
252 if (n == 0) /* connection closed */
253 shut = 1;
254 }
255
256 for (;;) {
257 if ((n = imsg_get(ibuf, &imsg)) == -1)
258 fatal("dvmrpe_dispatch_main: imsg_read error");
259 if (n == 0)
260 break;
261
262 switch (imsg.hdr.type) {
263 case IMSG_IFINFO:
264 if (imsg.hdr.len - IMSG_HEADER_SIZE !=
265 sizeof(struct kif))
266 fatalx("IFINFO imsg with wrong len");
267 kif = imsg.data;
268 link_ok = (kif->flags & IFF_UP) &&
269 LINK_STATE_IS_UP(kif->link_state);
270
271 LIST_FOREACH(iface, &deconf->iface_list, entry) {
272 if (kif->ifindex == iface->ifindex) {
273 iface->flags = kif->flags;
274 iface->linkstate = kif->link_state;
275
276 if (link_ok) {
277 if_fsm(iface, IF_EVT_UP);
278 log_warnx("interface %s up",
279 iface->name);
280 } else {
281 if_fsm(iface, IF_EVT_DOWN);
282 log_warnx("interface %s down",
283 iface->name);
284 }
285 }
286 }
287 break;
288 default:
289 log_debug("dvmrpe_dispatch_main: error handling "
290 "imsg %d", imsg.hdr.type);
291 break;
292 }
293 imsg_free(&imsg);
294 }
295 if (!shut)
296 imsg_event_add(iev);
297 else {
298 /* this pipe is dead, so remove the event handler */
299 event_del(&iev->ev);
300 event_loopexit(NULL);
301 }
302 }
303
304 void
dvmrpe_dispatch_rde(int fd,short event,void * bula)305 dvmrpe_dispatch_rde(int fd, short event, void *bula)
306 {
307 struct imsgev *iev = bula;
308 struct imsgbuf *ibuf = &iev->ibuf;
309 struct imsg imsg;
310 struct nbr *nbr;
311 struct prune p;
312 struct iface *iface;
313 struct route_report *rr;
314 ssize_t n;
315 int shut = 0;
316
317 if (event & EV_READ) {
318 if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
319 fatal("imsg_read error");
320 if (n == 0) /* connection closed */
321 shut = 1;
322 }
323 if (event & EV_WRITE) {
324 if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
325 fatal("msgbuf_write");
326 if (n == 0) /* connection closed */
327 shut = 1;
328 }
329
330 for (;;) {
331 if ((n = imsg_get(ibuf, &imsg)) == -1)
332 fatal("dvmrpe_dispatch_rde: imsg_read error");
333 if (n == 0)
334 break;
335
336 switch (imsg.hdr.type) {
337 case IMSG_CTL_SHOW_RIB:
338 case IMSG_CTL_SHOW_SUM:
339 case IMSG_CTL_SHOW_MFC:
340 case IMSG_CTL_END:
341 control_imsg_relay(&imsg);
342 break;
343 case IMSG_FULL_ROUTE_REPORT:
344 /* add route reports to list */
345 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(*rr))
346 fatalx("invalid size of RDE request");
347
348 if ((rr = calloc(1, sizeof(*rr))) == NULL)
349 fatal("dvmrpe_dispatch_rde");
350
351 memcpy(rr, imsg.data, sizeof(*rr));
352
353 /* general update, per interface */
354 if (imsg.hdr.peerid == 0) {
355 /* add to interface list */
356 LIST_FOREACH(iface, &deconf->iface_list,
357 entry) {
358 if (!if_nbr_list_empty(iface))
359 rr_list_add(&iface->rr_list,
360 rr);
361 }
362 break;
363 }
364
365 /* add to neighbor list */
366 nbr = nbr_find_peerid(imsg.hdr.peerid);
367 rr_list_add(&nbr->rr_list, rr);
368 break;
369 case IMSG_FULL_ROUTE_REPORT_END:
370 /* transmit route report */
371 if (imsg.hdr.peerid == 0) {
372 /*
373 * send general route report on all
374 * interfaces with neighbors.
375 */
376 LIST_FOREACH(iface, &deconf->iface_list,
377 entry) {
378 rr_list_send(&iface->rr_list,
379 iface, NULL);
380 }
381 break;
382 }
383
384 nbr = nbr_find_peerid(imsg.hdr.peerid);
385 rr_list_send(&nbr->rr_list, NULL, nbr);
386 break;
387 case IMSG_SEND_PRUNE:
388 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(p))
389 fatalx("invalid size of RDE request");
390
391 memcpy(&p, imsg.data, sizeof(p));
392
393 LIST_FOREACH(iface, &deconf->iface_list, entry)
394 if (p.ifindex == iface->ifindex)
395 break;
396
397 if (iface == NULL)
398 fatalx("invalid interface in mfc");
399
400 nbr = nbr_find_ip(iface, p.nexthop.s_addr);
401 if (nbr == NULL)
402 fatalx("unknown neighbor to send prune");
403
404 send_prune(nbr, &p);
405
406 break;
407 case IMSG_FLASH_UPDATE:
408 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(*rr))
409 fatalx("invalid size of RDE request");
410
411 if ((rr = calloc(1, sizeof(*rr))) == NULL)
412 fatal("dvmrpe_dispatch_rde");
413
414 memcpy(rr, imsg.data, sizeof(*rr));
415
416 LIST_FOREACH(iface, &deconf->iface_list, entry) {
417 if (!if_nbr_list_empty(iface)) {
418 rr_list_add(&iface->rr_list, rr);
419 rr_list_send(&iface->rr_list, iface,
420 NULL);
421 }
422 }
423 break;
424 case IMSG_FLASH_UPDATE_DS:
425 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(*rr))
426 fatalx("invalid size of RDE request");
427
428 if ((rr = calloc(1, sizeof(*rr))) == NULL)
429 fatal("dvmrpe_dispatch_rde");
430
431 memcpy(rr, imsg.data, sizeof(*rr));
432
433 LIST_FOREACH(iface, &deconf->iface_list, entry) {
434 if (iface->ifindex == rr->ifindex)
435 continue;
436 if (!if_nbr_list_empty(iface)) {
437 rr_list_add(&iface->rr_list, rr);
438 rr_list_send(&iface->rr_list, iface,
439 NULL);
440 }
441 }
442 break;
443 default:
444 log_debug("dvmrpe_dispatch_rde: error handling imsg %d",
445 imsg.hdr.type);
446 break;
447 }
448 imsg_free(&imsg);
449 }
450 if (!shut)
451 imsg_event_add(iev);
452 else {
453 /* this pipe is dead, so remove the event handler */
454 event_del(&iev->ev);
455 event_loopexit(NULL);
456 }
457 }
458
459 void
dvmrpe_iface_ctl(struct ctl_conn * c,unsigned int idx)460 dvmrpe_iface_ctl(struct ctl_conn *c, unsigned int idx)
461 {
462 struct iface *iface;
463 struct ctl_iface *ictl;
464
465 LIST_FOREACH(iface, &deconf->iface_list, entry)
466 if (idx == 0 || idx == iface->ifindex) {
467 ictl = if_to_ctl(iface);
468 imsg_compose_event(&c->iev, IMSG_CTL_SHOW_IFACE,
469 0, 0, -1, ictl, sizeof(struct ctl_iface));
470 }
471 }
472
473 void
dvmrpe_iface_igmp_ctl(struct ctl_conn * c,unsigned int idx)474 dvmrpe_iface_igmp_ctl(struct ctl_conn *c, unsigned int idx)
475 {
476 struct iface *iface;
477 struct ctl_iface *ictl;
478
479 LIST_FOREACH(iface, &deconf->iface_list, entry)
480 if (idx == 0 || idx == iface->ifindex) {
481 ictl = if_to_ctl(iface);
482 imsg_compose_event(&c->iev, IMSG_CTL_SHOW_IFACE,
483 0, 0, -1, ictl, sizeof(struct ctl_iface));
484 group_list_dump(iface, c);
485
486 }
487 }
488
489 void
dvmrpe_nbr_ctl(struct ctl_conn * c)490 dvmrpe_nbr_ctl(struct ctl_conn *c)
491 {
492 struct iface *iface;
493 struct nbr *nbr;
494 struct ctl_nbr *nctl;
495
496 LIST_FOREACH(iface, &deconf->iface_list, entry)
497 LIST_FOREACH(nbr, &iface->nbr_list, entry) {
498 nctl = nbr_to_ctl(nbr);
499 imsg_compose_event(&c->iev, IMSG_CTL_SHOW_NBR,
500 0, 0, -1, nctl, sizeof(struct ctl_nbr));
501 }
502
503 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 0, -1, NULL, 0);
504 }
505