bgpd.c revision 1.89 
1/*	$OpenBSD: bgpd.c,v 1.89 2004/04/25 17:34:39 claudio Exp $ */
2
3/*
4 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <sys/types.h>
20#include <sys/socket.h>
21#include <sys/wait.h>
22#include <netinet/in.h>
23#include <arpa/inet.h>
24#include <err.h>
25#include <errno.h>
26#include <fcntl.h>
27#include <poll.h>
28#include <pwd.h>
29#include <signal.h>
30#include <stdio.h>
31#include <stdlib.h>
32#include <string.h>
33#include <unistd.h>
34
35#include "mrt.h"
36#include "bgpd.h"
37#include "session.h"
38
39void	sighdlr(int);
40void	usage(void);
41int	main(int, char *[]);
42int	check_child(pid_t, const char *);
43int	reconfigure(char *, struct bgpd_config *, struct mrt_head *,
44	    struct peer **, struct filter_head *);
45int	dispatch_imsg(struct imsgbuf *, int, struct mrt_head *);
46
47int			rfd = -1;
48volatile sig_atomic_t	mrtdump = 0;
49volatile sig_atomic_t	quit = 0;
50volatile sig_atomic_t	reconfig = 0;
51volatile sig_atomic_t	sigchld = 0;
52struct imsgbuf		ibuf_se;
53struct imsgbuf		ibuf_rde;
54
55void
56sighdlr(int sig)
57{
58	switch (sig) {
59	case SIGTERM:
60	case SIGINT:
61		quit = 1;
62		break;
63	case SIGCHLD:
64		sigchld = 1;
65		break;
66	case SIGHUP:
67		reconfig = 1;
68		break;
69	case SIGALRM:
70	case SIGUSR1:
71		mrtdump = 1;
72		break;
73	}
74}
75
76void
77usage(void)
78{
79	extern char *__progname;
80
81	fprintf(stderr, "usage: %s [-dnv] ", __progname);
82	fprintf(stderr, "[-D macro=value] [-f file]\n");
83	exit(1);
84}
85
86#define POLL_MAX		8
87#define PFD_PIPE_SESSION	0
88#define PFD_PIPE_ROUTE		1
89#define PFD_SOCK_ROUTE		2
90#define PFD_MRT_START		3
91
92int
93main(int argc, char *argv[])
94{
95	struct bgpd_config	 conf;
96	struct peer		*peer_l, *p;
97	struct mrt_head		 mrt_l;
98	struct network_head	 net_l;
99	struct filter_head	*rules_l;
100	struct network		*net;
101	struct filter_rule	*r;
102	struct mrt		*(mrt[POLL_MAX]), *m;
103	struct pollfd		 pfd[POLL_MAX];
104	pid_t			 io_pid = 0, rde_pid = 0, pid;
105	char			*conffile;
106	int			 debug = 0;
107	int			 ch, i, j, n, nfds, timeout;
108	int			 pipe_m2s[2];
109	int			 pipe_m2r[2];
110	int			 pipe_s2r[2];
111
112	conffile = CONFFILE;
113	bgpd_process = PROC_MAIN;
114
115	log_init(1);		/* log to stderr until daemonized */
116
117	if ((rules_l = calloc(1, sizeof(struct filter_head))) == NULL)
118		err(1, NULL);
119
120	bzero(&conf, sizeof(conf));
121	LIST_INIT(&mrt_l);
122	TAILQ_INIT(&net_l);
123	TAILQ_INIT(rules_l);
124	peer_l = NULL;
125
126	while ((ch = getopt(argc, argv, "dD:f:nv")) != -1) {
127		switch (ch) {
128		case 'd':
129			debug = 1;
130			break;
131		case 'D':
132			if (cmdline_symset(optarg) < 0)
133				log_warnx("could not parse macro definition %s",
134				    optarg);
135			break;
136		case 'f':
137			conffile = optarg;
138			break;
139		case 'n':
140			conf.opts |= BGPD_OPT_NOACTION;
141			break;
142		case 'v':
143			if (conf.opts & BGPD_OPT_VERBOSE)
144				conf.opts |= BGPD_OPT_VERBOSE2;
145			conf.opts |= BGPD_OPT_VERBOSE;
146			break;
147		default:
148			usage();
149			/* NOTREACHED */
150		}
151	}
152
153	if (parse_config(conffile, &conf, &mrt_l, &peer_l, &net_l, rules_l))
154		exit(1);
155
156	if (conf.opts & BGPD_OPT_NOACTION) {
157		if (conf.opts & BGPD_OPT_VERBOSE)
158			print_config(&conf, &net_l, peer_l, rules_l, &mrt_l);
159		else
160			fprintf(stderr, "configuration OK\n");
161		exit(0);
162	}
163
164	if (geteuid())
165		errx(1, "need root privileges");
166
167	if (getpwnam(BGPD_USER) == NULL)
168		errx(1, "unknown user %s", BGPD_USER);
169	endpwent();
170
171	log_init(debug);
172
173	if (!debug)
174		daemon(1, 0);
175
176	log_info("startup");
177
178	if (pipe(pipe_m2s) == -1)
179		fatal("pipe");
180	if (fcntl(pipe_m2s[0], F_SETFL, O_NONBLOCK) == -1 ||
181	    fcntl(pipe_m2s[1], F_SETFL, O_NONBLOCK) == -1)
182		fatal("fcntl");
183	if (pipe(pipe_m2r) == -1)
184		fatal("pipe");
185	if (fcntl(pipe_m2r[0], F_SETFL, O_NONBLOCK) == -1 ||
186	    fcntl(pipe_m2r[1], F_SETFL, O_NONBLOCK) == -1)
187		fatal("fcntl");
188	if (pipe(pipe_s2r) == -1)
189		fatal("pipe");
190	if (fcntl(pipe_s2r[0], F_SETFL, O_NONBLOCK) == -1 ||
191	    fcntl(pipe_s2r[1], F_SETFL, O_NONBLOCK) == -1)
192		fatal("fcntl");
193
194	/* fork children */
195	rde_pid = rde_main(&conf, &net_l, rules_l, &mrt_l, pipe_m2r, pipe_s2r);
196	io_pid = session_main(&conf, peer_l, &net_l, rules_l, &mrt_l,
197	    pipe_m2s, pipe_s2r);
198
199	setproctitle("parent");
200
201	signal(SIGTERM, sighdlr);
202	signal(SIGINT, sighdlr);
203	signal(SIGCHLD, sighdlr);
204	signal(SIGHUP, sighdlr);
205	signal(SIGALRM, sighdlr);
206	signal(SIGUSR1, sighdlr);
207
208	close(pipe_m2s[1]);
209	close(pipe_m2r[1]);
210	close(pipe_s2r[0]);
211	close(pipe_s2r[1]);
212
213	imsg_init(&ibuf_se, pipe_m2s[0]);
214	imsg_init(&ibuf_rde, pipe_m2r[0]);
215	mrt_init(&ibuf_rde, &ibuf_se);
216	if ((rfd = kr_init(!(conf.flags & BGPD_FLAG_NO_FIB_UPDATE))) == -1)
217		quit = 1;
218
219	while ((net = TAILQ_FIRST(&net_l)) != NULL) {
220		TAILQ_REMOVE(&net_l, net, network_l);
221		free(net);
222	}
223
224	while ((r = TAILQ_FIRST(rules_l)) != NULL) {
225		TAILQ_REMOVE(rules_l, r, entries);
226		free(r);
227	}
228
229	while (quit == 0) {
230		pfd[PFD_PIPE_SESSION].fd = ibuf_se.sock;
231		pfd[PFD_PIPE_SESSION].events = POLLIN;
232		if (ibuf_se.w.queued)
233			pfd[PFD_PIPE_SESSION].events |= POLLOUT;
234		pfd[PFD_PIPE_ROUTE].fd = ibuf_rde.sock;
235		pfd[PFD_PIPE_ROUTE].events = POLLIN;
236		if (ibuf_rde.w.queued)
237			pfd[PFD_PIPE_ROUTE].events |= POLLOUT;
238		pfd[PFD_SOCK_ROUTE].fd = rfd;
239		pfd[PFD_SOCK_ROUTE].events = POLLIN;
240		i = PFD_MRT_START;
241		i = mrt_select(&mrt_l, pfd, mrt, i, POLL_MAX, &timeout);
242
243		if ((nfds = poll(pfd, i, INFTIM)) == -1)
244			if (errno != EINTR) {
245				log_warn("poll error");
246				quit = 1;
247			}
248
249		if (nfds > 0 && (pfd[PFD_PIPE_SESSION].revents & POLLOUT))
250			if ((n = msgbuf_write(&ibuf_se.w)) < 0) {
251				log_warn("pipe write error (to SE)");
252				quit = 1;
253			}
254
255		if (nfds > 0 && (pfd[PFD_PIPE_ROUTE].revents & POLLOUT))
256			if ((n = msgbuf_write(&ibuf_rde.w)) < 0) {
257				log_warn("pipe write error (to RDE)");
258				quit = 1;
259			}
260
261		if (nfds > 0 && pfd[PFD_PIPE_SESSION].revents & POLLIN) {
262			nfds--;
263			if (dispatch_imsg(&ibuf_se, PFD_PIPE_SESSION,
264			    &mrt_l) == -1)
265				quit = 1;
266		}
267
268		if (nfds > 0 && pfd[PFD_PIPE_ROUTE].revents & POLLIN) {
269			nfds--;
270			if (dispatch_imsg(&ibuf_rde, PFD_PIPE_ROUTE,
271			    &mrt_l) == -1)
272				quit = 1;
273		}
274
275		if (nfds > 0 && pfd[PFD_SOCK_ROUTE].revents & POLLIN) {
276			nfds--;
277			if (kr_dispatch_msg() == -1)
278				quit = 1;
279		}
280
281		for (j = PFD_MRT_START; j < i && nfds > 0 ; j++) {
282			if (pfd[j].revents & POLLOUT) {
283				if ((n = mrt_write(mrt[j])) < 0) {
284					log_warn("mrt write error");
285				}
286			}
287		}
288
289		if (reconfig) {
290			log_info("rereading config");
291			reconfigure(conffile, &conf, &mrt_l, &peer_l, rules_l);
292			reconfig = 0;
293		}
294
295		if (sigchld) {
296			if (check_child(io_pid, "session engine"))
297				quit = 1;
298			if (check_child(rde_pid, "route decision engine"))
299				quit = 1;
300			sigchld = 0;
301		}
302
303		if (mrtdump == 1) {
304			mrt_handler(&mrt_l);
305			mrtdump = 0;
306		}
307	}
308
309	signal(SIGCHLD, SIG_IGN);
310
311	if (io_pid)
312		kill(io_pid, SIGTERM);
313
314	if (rde_pid)
315		kill(rde_pid, SIGTERM);
316
317	while ((p = peer_l) != NULL) {
318		peer_l = p->next;
319		free(p);
320	}
321	while ((m = LIST_FIRST(&mrt_l)) != NULL) {
322		LIST_REMOVE(m, list);
323		free(m);
324	}
325
326	free(rules_l);
327	control_cleanup();
328	kr_shutdown();
329
330	do {
331		if ((pid = wait(NULL)) == -1 &&
332		    errno != EINTR && errno != ECHILD)
333			fatal("wait");
334	} while (pid != -1 || (pid == -1 && errno == EINTR));
335
336	log_info("Terminating");
337	return (0);
338}
339
340int
341check_child(pid_t pid, const char *pname)
342{
343	int	status;
344
345	if (waitpid(pid, &status, WNOHANG) > 0) {
346		if (WIFEXITED(status)) {
347			log_warnx("Lost child: %s exited", pname);
348			return (1);
349		}
350		if (WIFSIGNALED(status)) {
351			log_warnx("Lost child: %s terminated; signal %d",
352			    pname, WTERMSIG(status));
353			return (1);
354		}
355	}
356
357	return (0);
358}
359
360int
361reconfigure(char *conffile, struct bgpd_config *conf, struct mrt_head *mrt_l,
362    struct peer **peer_l, struct filter_head *rules_l)
363{
364	struct network_head	 net_l;
365	struct network		*n;
366	struct peer		*p;
367	struct filter_rule	*r;
368
369	if (parse_config(conffile, conf, mrt_l, peer_l, &net_l, rules_l)) {
370		log_warnx("config file %s has errors, not reloading",
371		    conffile);
372		return (-1);
373	}
374
375	if (imsg_compose(&ibuf_se, IMSG_RECONF_CONF, 0,
376	    conf, sizeof(struct bgpd_config)) == -1)
377		return (-1);
378	if (imsg_compose(&ibuf_rde, IMSG_RECONF_CONF, 0,
379	    conf, sizeof(struct bgpd_config)) == -1)
380		return (-1);
381	for (p = *peer_l; p != NULL; p = p->next)
382		if (imsg_compose(&ibuf_se, IMSG_RECONF_PEER, p->conf.id,
383		    &p->conf, sizeof(struct peer_config)) == -1)
384			return (-1);
385	while ((n = TAILQ_FIRST(&net_l)) != NULL) {
386		if (imsg_compose(&ibuf_rde, IMSG_RECONF_NETWORK, 0,
387		    &n->net, sizeof(struct network_config)) == -1)
388			return (-1);
389		TAILQ_REMOVE(&net_l, n, network_l);
390		free(n);
391	}
392	while ((r = TAILQ_FIRST(rules_l)) != NULL) {
393		if (imsg_compose(&ibuf_rde, IMSG_RECONF_FILTER, 0,
394		    r, sizeof(struct filter_rule)) == -1)
395			return (-1);
396		TAILQ_REMOVE(rules_l, r, entries);
397		free(r);
398	}
399	if (imsg_compose(&ibuf_se, IMSG_RECONF_DONE, 0, NULL, 0) == -1 ||
400	    imsg_compose(&ibuf_rde, IMSG_RECONF_DONE, 0, NULL, 0) == -1)
401		return (-1);
402
403	return (0);
404}
405
406int
407dispatch_imsg(struct imsgbuf *ibuf, int idx, struct mrt_head *mrt_l)
408{
409	struct imsg		 imsg;
410	int			 n;
411
412	if ((n = imsg_read(ibuf)) == -1)
413		return (-1);
414
415	if (n == 0) {	/* connection closed */
416		log_warnx("dispatch_imsg in main: pipe closed");
417		return (-1);
418	}
419
420	for (;;) {
421		if ((n = imsg_get(ibuf, &imsg)) == -1)
422			return (-1);
423
424		if (n == 0)
425			break;
426
427		switch (imsg.hdr.type) {
428		case IMSG_MRT_MSG:
429		case IMSG_MRT_END:
430			if (mrt_queue(mrt_l, &imsg) == -1)
431				log_warnx("mrt_queue failed.");
432			break;
433		case IMSG_KROUTE_CHANGE:
434			if (idx != PFD_PIPE_ROUTE)
435				log_warnx("route request not from RDE");
436			else if (kr_change(imsg.data))
437				return (-1);
438			break;
439		case IMSG_KROUTE_DELETE:
440			if (idx != PFD_PIPE_ROUTE)
441				log_warnx("route request not from RDE");
442			else if (kr_delete(imsg.data))
443				return (-1);
444			break;
445		case IMSG_NEXTHOP_ADD:
446			if (idx != PFD_PIPE_ROUTE)
447				log_warnx("nexthop request not from RDE");
448			else
449				if (imsg.hdr.len != IMSG_HEADER_SIZE +
450				    sizeof(struct bgpd_addr))
451					log_warnx("wrong imsg len");
452				else if (kr_nexthop_add(imsg.data) == -1)
453					return (-1);
454			break;
455		case IMSG_NEXTHOP_REMOVE:
456			if (idx != PFD_PIPE_ROUTE)
457				log_warnx("nexthop request not from RDE");
458			else
459				if (imsg.hdr.len != IMSG_HEADER_SIZE +
460				    sizeof(struct bgpd_addr))
461					log_warnx("wrong imsg len");
462				else kr_nexthop_delete(imsg.data);
463			break;
464		case IMSG_CTL_RELOAD:
465			if (idx != PFD_PIPE_SESSION)
466				log_warnx("reload request not from SE");
467			else
468				reconfig = 1;
469			break;
470		case IMSG_CTL_FIB_COUPLE:
471			if (idx != PFD_PIPE_SESSION)
472				log_warnx("couple request not from SE");
473			else
474				kr_fib_couple();
475			break;
476		case IMSG_CTL_FIB_DECOUPLE:
477			if (idx != PFD_PIPE_SESSION)
478				log_warnx("decouple request not from SE");
479			else
480				kr_fib_decouple();
481			break;
482		case IMSG_CTL_KROUTE:
483		case IMSG_CTL_KROUTE_ADDR:
484		case IMSG_CTL_SHOW_NEXTHOP:
485		case IMSG_CTL_SHOW_INTERFACE:
486			if (idx != PFD_PIPE_SESSION)
487				log_warnx("kroute request not from SE");
488			else
489				kr_show_route(&imsg);
490			break;
491		default:
492			break;
493		}
494		imsg_free(&imsg);
495	}
496	return (0);
497}
498
499void
500send_nexthop_update(struct kroute_nexthop *msg)
501{
502	char	*gw = NULL;
503
504	if (msg->gateway.af)
505		if (asprintf(&gw, ": via %s",
506		    log_addr(&msg->gateway)) == -1) {
507			log_warn("send_nexthop_update");
508			quit = 1;
509		}
510
511	log_info("nexthop %s now %s%s%s", log_addr(&msg->nexthop),
512	    msg->valid ? "valid" : "invalid",
513	    msg->connected ? ": directly connected" : "",
514	    msg->gateway.af ? gw : "");
515
516	free(gw);
517
518	if (imsg_compose(&ibuf_rde, IMSG_NEXTHOP_UPDATE, 0,
519	    msg, sizeof(struct kroute_nexthop)) == -1)
520		quit = 1;
521}
522
523void
524send_imsg_session(int type, pid_t pid, void *data, u_int16_t datalen)
525{
526	imsg_compose_pid(&ibuf_se, type, pid, data, datalen);
527}
528