xref: /openbsd-src/sbin/dhcpleased/dhcpleased.c (revision 0e59d0d19ca6a10a17663d531bcea1b99c1bfe09)
1 /*	$OpenBSD: dhcpleased.c,v 1.39 2024/11/21 13:35:20 claudio Exp $	*/
2 
3 /*
4  * Copyright (c) 2017, 2021 Florian Obser <florian@openbsd.org>
5  * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
6  * Copyright (c) 2004 Esben Norby <norby@openbsd.org>
7  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
8  *
9  * Permission to use, copy, modify, and distribute this software for any
10  * purpose with or without fee is hereby granted, provided that the above
11  * copyright notice and this permission notice appear in all copies.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
14  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
16  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
19  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20  */
21 #include <sys/types.h>
22 #include <sys/ioctl.h>
23 #include <sys/queue.h>
24 #include <sys/socket.h>
25 #include <sys/stat.h>
26 #include <sys/syslog.h>
27 #include <sys/sysctl.h>
28 #include <sys/uio.h>
29 #include <sys/wait.h>
30 
31 #include <net/if.h>
32 #include <net/route.h>
33 #include <net/if_dl.h>
34 #include <netinet/in.h>
35 #include <netinet/if_ether.h>
36 #include <netinet/in_var.h>
37 
38 #include <arpa/inet.h>
39 
40 #include <err.h>
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <event.h>
44 #include <ifaddrs.h>
45 #include <imsg.h>
46 #include <netdb.h>
47 #include <pwd.h>
48 #include <stddef.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <signal.h>
53 #include <unistd.h>
54 
55 #include "bpf.h"
56 #include "log.h"
57 #include "dhcpleased.h"
58 #include "frontend.h"
59 #include "engine.h"
60 #include "control.h"
61 
62 enum dhcpleased_process {
63 	PROC_MAIN,
64 	PROC_ENGINE,
65 	PROC_FRONTEND
66 };
67 
68 __dead void	usage(void);
69 __dead void	main_shutdown(void);
70 
71 void	main_sig_handler(int, short, void *);
72 
73 static pid_t	start_child(enum dhcpleased_process, char *, int, int, int);
74 
75 void	 main_dispatch_frontend(int, short, void *);
76 void	 main_dispatch_engine(int, short, void *);
77 void	 open_bpfsock(uint32_t);
78 void	 configure_interface(struct imsg_configure_interface *);
79 void	 deconfigure_interface(struct imsg_configure_interface *);
80 void	 propose_rdns(struct imsg_propose_rdns *);
81 void	 configure_routes(uint8_t, struct imsg_configure_interface *);
82 void	 configure_route(uint8_t, uint32_t, int, struct sockaddr_in *, struct
83 	     sockaddr_in *, struct sockaddr_in *, struct sockaddr_in *, int);
84 void	 read_lease_file(struct imsg_ifinfo *);
85 
86 static int	main_imsg_send_ipc_sockets(struct imsgbuf *, struct imsgbuf *);
87 int		main_imsg_compose_frontend(int, int, void *, uint16_t);
88 int		main_imsg_compose_engine(int, int, void *, uint16_t);
89 
90 #ifndef SMALL
91 int		main_imsg_send_config(struct dhcpleased_conf *);
92 #endif /* SMALL */
93 int	main_reload(void);
94 
95 static struct imsgev	*iev_frontend;
96 static struct imsgev	*iev_engine;
97 
98 #ifndef SMALL
99 struct dhcpleased_conf	*main_conf;
100 #endif
101 const char		 default_conffile[] = _PATH_CONF_FILE;
102 const char		*conffile = default_conffile;
103 pid_t			 frontend_pid;
104 pid_t			 engine_pid;
105 
106 int			 routesock, ioctl_sock, rtm_seq, no_lease_files;
107 
108 void
109 main_sig_handler(int sig, short event, void *arg)
110 {
111 	/*
112 	 * Normal signal handler rules don't apply because libevent
113 	 * decouples for us.
114 	 */
115 
116 	switch (sig) {
117 	case SIGTERM:
118 	case SIGINT:
119 		main_shutdown();
120 	case SIGHUP:
121 #ifndef SMALL
122 		if (main_reload() == -1)
123 			log_warnx("configuration reload failed");
124 		else
125 			log_debug("configuration reloaded");
126 #endif /* SMALL */
127 		break;
128 	default:
129 		fatalx("unexpected signal");
130 	}
131 }
132 
133 __dead void
134 usage(void)
135 {
136 	extern char *__progname;
137 
138 	fprintf(stderr, "usage: %s [-dnv] [-f file] [-s socket]\n",
139 	    __progname);
140 	exit(1);
141 }
142 
143 int
144 main(int argc, char *argv[])
145 {
146 	struct event		 ev_sigint, ev_sigterm, ev_sighup;
147 	int			 ch;
148 	int			 debug = 0, engine_flag = 0, frontend_flag = 0;
149 	int			 verbose = 0, no_action = 0;
150 	char			*saved_argv0;
151 	int			 pipe_main2frontend[2];
152 	int			 pipe_main2engine[2];
153 	int			 frontend_routesock, rtfilter, lockfd;
154 	int			 rtable_any = RTABLE_ANY;
155 	char			*csock = _PATH_DHCPLEASED_SOCKET;
156 #ifndef SMALL
157 	int			 control_fd;
158 #endif /* SMALL */
159 
160 	log_init(1, LOG_DAEMON);	/* Log to stderr until daemonized. */
161 	log_setverbose(1);
162 
163 	saved_argv0 = argv[0];
164 	if (saved_argv0 == NULL)
165 		saved_argv0 = "dhcpleased";
166 
167 	while ((ch = getopt(argc, argv, "dEFf:ns:v")) != -1) {
168 		switch (ch) {
169 		case 'd':
170 			debug = 1;
171 			break;
172 		case 'E':
173 			engine_flag = 1;
174 			break;
175 		case 'F':
176 			frontend_flag = 1;
177 			break;
178 		case 'f':
179 			conffile = optarg;
180 			break;
181 		case 'n':
182 			no_action = 1;
183 			break;
184 		case 's':
185 			csock = optarg;
186 			break;
187 		case 'v':
188 			verbose++;
189 			break;
190 		default:
191 			usage();
192 		}
193 	}
194 
195 	argc -= optind;
196 	argv += optind;
197 	if (argc > 0 || (engine_flag && frontend_flag))
198 		usage();
199 
200 	if (engine_flag)
201 		engine(debug, verbose);
202 	else if (frontend_flag)
203 		frontend(debug, verbose);
204 
205 #ifndef SMALL
206 	/* parse config file */
207 	if ((main_conf = parse_config(conffile)) == NULL)
208 		exit(1);
209 
210 	if (no_action) {
211 		if (verbose)
212 			print_config(main_conf);
213 		else
214 			fprintf(stderr, "configuration OK\n");
215 		exit(0);
216 	}
217 #endif /* SMALL */
218 
219 	/* Check for root privileges. */
220 	if (geteuid())
221 		errx(1, "need root privileges");
222 
223 	lockfd = open(_PATH_LOCKFILE, O_CREAT|O_RDWR|O_EXLOCK|O_NONBLOCK, 0600);
224 	if (lockfd == -1) {
225 		if (errno == EAGAIN)
226 			errx(1, "already running");
227 		err(1, "%s", _PATH_LOCKFILE);
228 	}
229 
230 	/* Check for assigned daemon user */
231 	if (getpwnam(DHCPLEASED_USER) == NULL)
232 		errx(1, "unknown user %s", DHCPLEASED_USER);
233 
234 	log_init(debug, LOG_DAEMON);
235 	log_setverbose(verbose);
236 
237 	if (!debug)
238 		daemon(0, 0);
239 
240 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
241 	    PF_UNSPEC, pipe_main2frontend) == -1)
242 		fatal("main2frontend socketpair");
243 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
244 	    PF_UNSPEC, pipe_main2engine) == -1)
245 		fatal("main2engine socketpair");
246 
247 	/* Start children. */
248 	engine_pid = start_child(PROC_ENGINE, saved_argv0, pipe_main2engine[1],
249 	    debug, verbose);
250 	frontend_pid = start_child(PROC_FRONTEND, saved_argv0,
251 	    pipe_main2frontend[1], debug, verbose);
252 
253 	log_procinit("main");
254 
255 	if ((routesock = socket(AF_ROUTE, SOCK_RAW | SOCK_CLOEXEC |
256 	    SOCK_NONBLOCK, AF_INET)) == -1)
257 		fatal("route socket");
258 	shutdown(routesock, SHUT_RD);
259 
260 	event_init();
261 
262 	/* Setup signal handler. */
263 	signal_set(&ev_sigint, SIGINT, main_sig_handler, NULL);
264 	signal_set(&ev_sigterm, SIGTERM, main_sig_handler, NULL);
265 	signal_set(&ev_sighup, SIGHUP, main_sig_handler, NULL);
266 	signal_add(&ev_sigint, NULL);
267 	signal_add(&ev_sigterm, NULL);
268 	signal_add(&ev_sighup, NULL);
269 	signal(SIGPIPE, SIG_IGN);
270 
271 	/* Setup pipes to children. */
272 
273 	if ((iev_frontend = malloc(sizeof(struct imsgev))) == NULL ||
274 	    (iev_engine = malloc(sizeof(struct imsgev))) == NULL)
275 		fatal(NULL);
276 	if (imsgbuf_init(&iev_frontend->ibuf, pipe_main2frontend[0]) == -1)
277 		fatal(NULL);
278 	imsgbuf_allow_fdpass(&iev_frontend->ibuf);
279 	iev_frontend->handler = main_dispatch_frontend;
280 	if (imsgbuf_init(&iev_engine->ibuf, pipe_main2engine[0]) == -1)
281 		fatal(NULL);
282 	imsgbuf_allow_fdpass(&iev_engine->ibuf);
283 	iev_engine->handler = main_dispatch_engine;
284 
285 	/* Setup event handlers for pipes to engine & frontend. */
286 	iev_frontend->events = EV_READ;
287 	event_set(&iev_frontend->ev, iev_frontend->ibuf.fd,
288 	    iev_frontend->events, iev_frontend->handler, iev_frontend);
289 	event_add(&iev_frontend->ev, NULL);
290 
291 	iev_engine->events = EV_READ;
292 	event_set(&iev_engine->ev, iev_engine->ibuf.fd, iev_engine->events,
293 	    iev_engine->handler, iev_engine);
294 	event_add(&iev_engine->ev, NULL);
295 
296 	if (main_imsg_send_ipc_sockets(&iev_frontend->ibuf, &iev_engine->ibuf))
297 		fatal("could not establish imsg links");
298 
299 	if ((ioctl_sock = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0)) == -1)
300 		fatal("socket");
301 
302 	if ((frontend_routesock = socket(AF_ROUTE, SOCK_RAW | SOCK_CLOEXEC,
303 	    AF_INET)) == -1)
304 		fatal("route socket");
305 
306 	rtfilter = ROUTE_FILTER(RTM_IFINFO) | ROUTE_FILTER(RTM_PROPOSAL) |
307 	    ROUTE_FILTER(RTM_IFANNOUNCE);
308 	if (setsockopt(frontend_routesock, AF_ROUTE, ROUTE_MSGFILTER,
309 	    &rtfilter, sizeof(rtfilter)) == -1)
310 		fatal("setsockopt(ROUTE_MSGFILTER)");
311 	if (setsockopt(frontend_routesock, AF_ROUTE, ROUTE_TABLEFILTER,
312 	    &rtable_any, sizeof(rtable_any)) == -1)
313 		fatal("setsockopt(ROUTE_TABLEFILTER)");
314 
315 #ifndef SMALL
316 	if ((control_fd = control_init(csock)) == -1)
317 		warnx("control socket setup failed");
318 #endif /* SMALL */
319 
320 	if (unveil(conffile, "r") == -1)
321 		fatal("unveil %s", conffile);
322 	if (unveil("/dev/bpf", "rw") == -1)
323 		fatal("unveil /dev/bpf");
324 
325 	if (unveil(_PATH_LEASE, "rwc") == -1) {
326 		no_lease_files = 1;
327 		log_warn("disabling lease files, unveil " _PATH_LEASE);
328 	}
329 
330 	if (unveil(NULL, NULL) == -1)
331 		fatal("unveil");
332 #if notyet
333 	if (pledge("stdio inet rpath wpath sendfd wroute bpf", NULL) == -1)
334 		fatal("pledge");
335 #endif
336 	main_imsg_compose_frontend(IMSG_ROUTESOCK, frontend_routesock, NULL, 0);
337 
338 #ifndef SMALL
339 	if (control_fd != -1)
340 		main_imsg_compose_frontend(IMSG_CONTROLFD, control_fd, NULL, 0);
341 	main_imsg_send_config(main_conf);
342 #endif /* SMALL */
343 
344 	main_imsg_compose_frontend(IMSG_STARTUP, -1, NULL, 0);
345 
346 	event_dispatch();
347 
348 	main_shutdown();
349 	return (0);
350 }
351 
352 __dead void
353 main_shutdown(void)
354 {
355 	pid_t	 pid;
356 	int	 status;
357 
358 	/* Close pipes. */
359 	imsgbuf_clear(&iev_frontend->ibuf);
360 	close(iev_frontend->ibuf.fd);
361 	imsgbuf_clear(&iev_engine->ibuf);
362 	close(iev_engine->ibuf.fd);
363 
364 #ifndef SMALL
365 	config_clear(main_conf);
366 #endif /* SMALL */
367 
368 	log_debug("waiting for children to terminate");
369 	do {
370 		pid = wait(&status);
371 		if (pid == -1) {
372 			if (errno != EINTR && errno != ECHILD)
373 				fatal("wait");
374 		} else if (WIFSIGNALED(status))
375 			log_warnx("%s terminated; signal %d",
376 			    (pid == engine_pid) ? "engine" :
377 			    "frontend", WTERMSIG(status));
378 	} while (pid != -1 || (pid == -1 && errno == EINTR));
379 
380 	free(iev_frontend);
381 	free(iev_engine);
382 
383 	log_info("terminating");
384 	exit(0);
385 }
386 
387 static pid_t
388 start_child(enum dhcpleased_process p, char *argv0, int fd, int debug, int
389     verbose)
390 {
391 	char	*argv[7];
392 	int	 argc = 0;
393 	pid_t	 pid;
394 
395 	switch (pid = fork()) {
396 	case -1:
397 		fatal("cannot fork");
398 	case 0:
399 		break;
400 	default:
401 		close(fd);
402 		return (pid);
403 	}
404 
405 	if (fd != 3) {
406 		if (dup2(fd, 3) == -1)
407 			fatal("cannot setup imsg fd");
408 	} else if (fcntl(fd, F_SETFD, 0) == -1)
409 		fatal("cannot setup imsg fd");
410 
411 	argv[argc++] = argv0;
412 	switch (p) {
413 	case PROC_MAIN:
414 		fatalx("Can not start main process");
415 	case PROC_ENGINE:
416 		argv[argc++] = "-E";
417 		break;
418 	case PROC_FRONTEND:
419 		argv[argc++] = "-F";
420 		break;
421 	}
422 	if (debug)
423 		argv[argc++] = "-d";
424 	if (verbose)
425 		argv[argc++] = "-v";
426 	if (verbose > 1)
427 		argv[argc++] = "-v";
428 	argv[argc++] = NULL;
429 
430 	execvp(argv0, argv);
431 	fatal("execvp");
432 }
433 
434 void
435 main_dispatch_frontend(int fd, short event, void *bula)
436 {
437 	struct imsgev		*iev = bula;
438 	struct imsgbuf		*ibuf;
439 	struct imsg		 imsg;
440 	struct imsg_ifinfo	 imsg_ifinfo;
441 	ssize_t			 n;
442 	int			 shut = 0;
443 	uint32_t		 if_index, type;
444 #ifndef	SMALL
445 	int			 verbose;
446 #endif	/* SMALL */
447 
448 	ibuf = &iev->ibuf;
449 
450 	if (event & EV_READ) {
451 		if ((n = imsgbuf_read(ibuf)) == -1)
452 			fatal("imsgbuf_read error");
453 		if (n == 0)	/* Connection closed. */
454 			shut = 1;
455 	}
456 	if (event & EV_WRITE) {
457 		if (imsgbuf_write(ibuf) == -1) {
458 			if (errno == EPIPE)	/* Connection closed. */
459 				shut = 1;
460 			else
461 				fatal("imsgbuf_write");
462 		}
463 	}
464 
465 	for (;;) {
466 		if ((n = imsg_get(ibuf, &imsg)) == -1)
467 			fatal("imsg_get");
468 		if (n == 0)	/* No more messages. */
469 			break;
470 
471 		type = imsg_get_type(&imsg);
472 
473 		switch (type) {
474 		case IMSG_OPEN_BPFSOCK:
475 			if (imsg_get_data(&imsg, &if_index,
476 			    sizeof(if_index)) == -1)
477 				fatalx("%s: invalid %s", __func__, i2s(type));
478 
479 			open_bpfsock(if_index);
480 			break;
481 #ifndef	SMALL
482 		case IMSG_CTL_RELOAD:
483 			if (main_reload() == -1)
484 				log_warnx("configuration reload failed");
485 			else
486 				log_warnx("configuration reloaded");
487 			break;
488 		case IMSG_CTL_LOG_VERBOSE:
489 			if (imsg_get_data(&imsg, &verbose,
490 			    sizeof(verbose)) == -1)
491 				fatalx("%s: invalid %s", __func__, i2s(type));
492 
493 			log_setverbose(verbose);
494 			break;
495 #endif	/* SMALL */
496 		case IMSG_UPDATE_IF:
497 			if (imsg_get_data(&imsg, &imsg_ifinfo,
498 			    sizeof(imsg_ifinfo)) == -1)
499 				fatalx("%s: invalid %s", __func__, i2s(type));
500 
501 			read_lease_file(&imsg_ifinfo);
502 			main_imsg_compose_engine(IMSG_UPDATE_IF, -1,
503 			    &imsg_ifinfo, sizeof(imsg_ifinfo));
504 			break;
505 		default:
506 			log_debug("%s: error handling imsg %d", __func__, type);
507 			break;
508 		}
509 		imsg_free(&imsg);
510 	}
511 	if (!shut)
512 		imsg_event_add(iev);
513 	else {
514 		/* This pipe is dead. Remove its event handler */
515 		event_del(&iev->ev);
516 		event_loopexit(NULL);
517 	}
518 }
519 
520 void
521 main_dispatch_engine(int fd, short event, void *bula)
522 {
523 	struct imsgev			*iev = bula;
524 	struct imsgbuf			*ibuf;
525 	struct imsg			 imsg;
526 	ssize_t				 n;
527 	uint32_t			 type;
528 	int				 shut = 0;
529 
530 	ibuf = &iev->ibuf;
531 
532 	if (event & EV_READ) {
533 		if ((n = imsgbuf_read(ibuf)) == -1)
534 			fatal("imsgbuf_read error");
535 		if (n == 0)	/* Connection closed. */
536 			shut = 1;
537 	}
538 	if (event & EV_WRITE) {
539 		if (imsgbuf_write(ibuf) == -1) {
540 			if (errno == EPIPE)	/* Connection closed. */
541 				shut = 1;
542 			else
543 				fatal("imsgbuf_write");
544 		}
545 	}
546 
547 	for (;;) {
548 		if ((n = imsg_get(ibuf, &imsg)) == -1)
549 			fatal("imsg_get");
550 		if (n == 0)	/* No more messages. */
551 			break;
552 
553 		type = imsg_get_type(&imsg);
554 
555 		switch (type) {
556 		case IMSG_CONFIGURE_INTERFACE: {
557 			struct imsg_configure_interface imsg_interface;
558 
559 			if (imsg_get_data(&imsg, &imsg_interface,
560 			    sizeof(imsg_interface)) == -1)
561 				fatalx("%s: invalid %s", __func__, i2s(type));
562 
563 			if (imsg_interface.routes_len >= MAX_DHCP_ROUTES)
564 				fatalx("%s: too many routes in imsg", __func__);
565 			configure_interface(&imsg_interface);
566 			break;
567 		}
568 		case IMSG_DECONFIGURE_INTERFACE: {
569 			struct imsg_configure_interface imsg_interface;
570 
571 			if (imsg_get_data(&imsg, &imsg_interface,
572 			    sizeof(imsg_interface)) == -1)
573 				fatalx("%s: invalid %s", __func__, i2s(type));
574 			if (imsg_interface.routes_len >= MAX_DHCP_ROUTES)
575 				fatalx("%s: too many routes in imsg", __func__);
576 
577 			deconfigure_interface(&imsg_interface);
578 			main_imsg_compose_frontend(IMSG_CLOSE_UDPSOCK, -1,
579 			    &imsg_interface.if_index,
580 			    sizeof(imsg_interface.if_index));
581 			break;
582 		}
583 		case IMSG_WITHDRAW_ROUTES: {
584 			struct imsg_configure_interface imsg_interface;
585 
586 			if (imsg_get_data(&imsg, &imsg_interface,
587 			    sizeof(imsg_interface)) == -1)
588 				fatalx("%s: invalid %s", __func__, i2s(type));
589 			if (imsg_interface.routes_len >= MAX_DHCP_ROUTES)
590 				fatalx("%s: too many routes in imsg", __func__);
591 
592 			if (imsg_interface.routes_len > 0)
593 				configure_routes(RTM_DELETE, &imsg_interface);
594 			break;
595 		}
596 		case IMSG_PROPOSE_RDNS: {
597 			struct imsg_propose_rdns	 rdns;
598 
599 			if (imsg_get_data(&imsg, &rdns, sizeof(rdns)) == -1)
600 				fatalx("%s: invalid %s", __func__, i2s(type));
601 			if ((2 + rdns.rdns_count * sizeof(struct in_addr)) >
602 			    sizeof(struct sockaddr_rtdns))
603 				fatalx("%s: rdns_count too big: %d", __func__,
604 				    rdns.rdns_count);
605 
606 			propose_rdns(&rdns);
607 			break;
608 		}
609 		case IMSG_WITHDRAW_RDNS: {
610 			struct imsg_propose_rdns	 rdns;
611 
612 			if (imsg_get_data(&imsg, &rdns, sizeof(rdns)) == -1)
613 				fatalx("%s: invalid %s", __func__, i2s(type));
614 			if (rdns.rdns_count != 0)
615 				fatalx("%s: expected rdns_count == 0: %d",
616 				    __func__, rdns.rdns_count);
617 
618 			propose_rdns(&rdns);
619 			break;
620 		}
621 		default:
622 			log_debug("%s: error handling imsg %d", __func__, type);
623 			break;
624 		}
625 		imsg_free(&imsg);
626 	}
627 	if (!shut)
628 		imsg_event_add(iev);
629 	else {
630 		/* This pipe is dead. Remove its event handler. */
631 		event_del(&iev->ev);
632 		event_loopexit(NULL);
633 	}
634 }
635 
636 int
637 main_imsg_compose_frontend(int type, int fd, void *data, uint16_t datalen)
638 {
639 	if (iev_frontend)
640 		return (imsg_compose_event(iev_frontend, type, 0, 0, fd, data,
641 		    datalen));
642 	else
643 		return (-1);
644 }
645 
646 int
647 main_imsg_compose_engine(int type, int fd, void *data, uint16_t datalen)
648 {
649 	if (iev_engine)
650 		return(imsg_compose_event(iev_engine, type, 0, 0, fd, data,
651 		    datalen));
652 	else
653 		return (-1);
654 }
655 
656 void
657 imsg_event_add(struct imsgev *iev)
658 {
659 	iev->events = EV_READ;
660 	if (imsgbuf_queuelen(&iev->ibuf) > 0)
661 		iev->events |= EV_WRITE;
662 
663 	event_del(&iev->ev);
664 	event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
665 	event_add(&iev->ev, NULL);
666 }
667 
668 int
669 imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
670     pid_t pid, int fd, void *data, uint16_t datalen)
671 {
672 	int	ret;
673 
674 	if ((ret = imsg_compose(&iev->ibuf, type, peerid, pid, fd, data,
675 	    datalen)) != -1)
676 		imsg_event_add(iev);
677 
678 	return (ret);
679 }
680 
681 int
682 imsg_forward_event(struct imsgev *iev, struct imsg *imsg)
683 {
684 	int	ret;
685 
686 	if ((ret = imsg_forward(&iev->ibuf, imsg)) != -1)
687 		imsg_event_add(iev);
688 
689 	return (ret);
690 }
691 
692 static int
693 main_imsg_send_ipc_sockets(struct imsgbuf *frontend_buf,
694     struct imsgbuf *engine_buf)
695 {
696 	int pipe_frontend2engine[2];
697 
698 	if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
699 	    PF_UNSPEC, pipe_frontend2engine) == -1)
700 		return (-1);
701 
702 	if (imsg_compose(frontend_buf, IMSG_SOCKET_IPC, 0, 0,
703 	    pipe_frontend2engine[0], NULL, 0) == -1)
704 		return (-1);
705 	imsgbuf_flush(frontend_buf);
706 	if (imsg_compose(engine_buf, IMSG_SOCKET_IPC, 0, 0,
707 	    pipe_frontend2engine[1], NULL, 0) == -1)
708 		return (-1);
709 	imsgbuf_flush(engine_buf);
710 	return (0);
711 }
712 
713 #ifndef SMALL
714 int
715 main_reload(void)
716 {
717 	struct dhcpleased_conf *xconf;
718 
719 	if ((xconf = parse_config(conffile)) == NULL)
720 		return (-1);
721 
722 	if (main_imsg_send_config(xconf) == -1)
723 		return (-1);
724 
725 	merge_config(main_conf, xconf);
726 
727 	return (0);
728 }
729 
730 int
731 main_imsg_send_config(struct dhcpleased_conf *xconf)
732 {
733 	struct iface_conf	*iface_conf;
734 
735 	main_imsg_compose_frontend(IMSG_RECONF_CONF, -1, NULL, 0);
736 	main_imsg_compose_engine(IMSG_RECONF_CONF, -1, NULL, 0);
737 
738 	/* Send the interface list to the frontend & engine. */
739 	SIMPLEQ_FOREACH(iface_conf, &xconf->iface_list, entry) {
740 		main_imsg_compose_frontend(IMSG_RECONF_IFACE, -1, iface_conf,
741 		    sizeof(*iface_conf));
742 		main_imsg_compose_engine(IMSG_RECONF_IFACE, -1, iface_conf,
743 		    sizeof(*iface_conf));
744 		if (iface_conf->vc_id_len) {
745 			main_imsg_compose_frontend(IMSG_RECONF_VC_ID, -1,
746 			    iface_conf->vc_id, iface_conf->vc_id_len);
747 			main_imsg_compose_engine(IMSG_RECONF_VC_ID, -1,
748 			    iface_conf->vc_id, iface_conf->vc_id_len);
749 		}
750 		if (iface_conf->c_id_len) {
751 			main_imsg_compose_frontend(IMSG_RECONF_C_ID, -1,
752 			    iface_conf->c_id, iface_conf->c_id_len);
753 			main_imsg_compose_engine(IMSG_RECONF_C_ID, -1,
754 			    iface_conf->c_id, iface_conf->c_id_len);
755 		}
756 		if (iface_conf->h_name != NULL)
757 			main_imsg_compose_frontend(IMSG_RECONF_H_NAME, -1,
758 			    iface_conf->h_name, strlen(iface_conf->h_name) + 1);
759 	}
760 
761 	/* Config is now complete. */
762 	main_imsg_compose_frontend(IMSG_RECONF_END, -1, NULL, 0);
763 	main_imsg_compose_engine(IMSG_RECONF_END, -1, NULL, 0);
764 
765 	return (0);
766 }
767 #endif /* SMALL */
768 
769 void
770 configure_interface(struct imsg_configure_interface *imsg)
771 {
772 	struct ifaliasreq	 ifaliasreq;
773 	struct ifaddrs		*ifap, *ifa;
774 	struct sockaddr_in	*req_sin_addr, *req_sin_mask;
775 	int			 found = 0, udpsock, opt = 1, len, fd = -1;
776 	char			*if_name;
777 	char			 ip_ntop_buf[INET_ADDRSTRLEN];
778 	char			 nextserver_ntop_buf[INET_ADDRSTRLEN];
779 	char			 lease_buf[LEASE_SIZE];
780 	char			 lease_file_buf[sizeof(_PATH_LEASE) +
781 	    IF_NAMESIZE];
782 	char			 tmpl[] = _PATH_LEASE"XXXXXXXXXX";
783 
784 	memset(&ifaliasreq, 0, sizeof(ifaliasreq));
785 
786 	if_name = if_indextoname(imsg->if_index, ifaliasreq.ifra_name);
787 	if (if_name == NULL) {
788 		log_warnx("%s: cannot find interface %d", __func__,
789 		    imsg->if_index);
790 		return;
791 	}
792 
793 	log_debug("%s %s", __func__, if_name);
794 
795 	if (getifaddrs(&ifap) != 0)
796 		fatal("getifaddrs");
797 
798 	req_sin_addr = (struct sockaddr_in *)&ifaliasreq.ifra_addr;
799 	req_sin_addr->sin_family = AF_INET;
800 	req_sin_addr->sin_len = sizeof(*req_sin_addr);
801 
802 	for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
803 		struct in_addr	 addr, mask;
804 
805 		if (strcmp(if_name, ifa->ifa_name) != 0)
806 			continue;
807 		if (ifa->ifa_addr == NULL)
808 			continue;
809 		if (ifa->ifa_addr->sa_family != AF_INET)
810 			continue;
811 
812 		addr = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
813 		mask = ((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr;
814 
815 		if (imsg->addr.s_addr == addr.s_addr) {
816 			if (imsg->mask.s_addr == mask.s_addr)
817 				found = 1;
818 			else {
819 				req_sin_addr->sin_addr = addr;
820 				if (ioctl(ioctl_sock, SIOCDIFADDR, &ifaliasreq)
821 				    == -1) {
822 					if (errno != EADDRNOTAVAIL)
823 						log_warn("SIOCDIFADDR");
824 				}
825 			}
826 			break;
827 		}
828 	}
829 	freeifaddrs(ifap);
830 
831 	req_sin_addr->sin_addr = imsg->addr;
832 	if (!found) {
833 		req_sin_mask = (struct sockaddr_in *)&ifaliasreq.ifra_mask;
834 		req_sin_mask->sin_family = AF_INET;
835 		req_sin_mask->sin_len = sizeof(*req_sin_mask);
836 		req_sin_mask->sin_addr = imsg->mask;
837 		if (ioctl(ioctl_sock, SIOCAIFADDR, &ifaliasreq) == -1)
838 			log_warn("SIOCAIFADDR");
839 	}
840 	if (imsg->routes_len > 0)
841 		configure_routes(RTM_ADD, imsg);
842 
843 	req_sin_addr->sin_port = ntohs(CLIENT_PORT);
844 	if ((udpsock = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
845 		log_warn("socket");
846 		return;
847 	}
848 	if (setsockopt(udpsock, SOL_SOCKET, SO_REUSEADDR, &opt,
849 	    sizeof(opt)) == -1)
850 		log_warn("setting SO_REUSEADDR on socket");
851 
852 	if (setsockopt(udpsock, SOL_SOCKET, SO_RTABLE, &imsg->rdomain,
853 	    sizeof(imsg->rdomain)) == -1) {
854 		/* we might race against removal of the rdomain */
855 		log_warn("setsockopt SO_RTABLE");
856 		close(udpsock);
857 		return;
858 	}
859 
860 	if (bind(udpsock, (struct sockaddr *)req_sin_addr,
861 	    sizeof(*req_sin_addr)) == -1) {
862 		close(udpsock);
863 		return;
864 	}
865 
866 	shutdown(udpsock, SHUT_RD);
867 
868 	main_imsg_compose_frontend(IMSG_UDPSOCK, udpsock,
869 	    &imsg->if_index, sizeof(imsg->if_index));
870 
871 	if (no_lease_files)
872 		return;
873 
874 	if (inet_ntop(AF_INET, &imsg->addr, ip_ntop_buf, sizeof(ip_ntop_buf)) ==
875 	    NULL) {
876 		log_warn("%s: inet_ntop", __func__);
877 		return;
878 	}
879 
880 	if (imsg->siaddr.s_addr == INADDR_ANY)
881 		nextserver_ntop_buf[0] = '\0';
882 	else {
883 		if (inet_ntop(AF_INET, &imsg->siaddr, nextserver_ntop_buf,
884 		    sizeof(nextserver_ntop_buf)) == NULL) {
885 			log_warn("%s: inet_ntop", __func__);
886 			return;
887 		}
888 	}
889 	len = snprintf(lease_file_buf, sizeof(lease_file_buf), "%s%s",
890 	    _PATH_LEASE, if_name);
891 	if ( len == -1 || (size_t) len >= sizeof(lease_file_buf)) {
892 		log_warnx("%s: failed to encode lease path for %s", __func__,
893 		    if_name);
894 		return;
895 	}
896 
897 	len = snprintf(lease_buf, sizeof(lease_buf),
898 	    "%s\n%s%s\n%s%s\n%s%s\n%s%s\n%s%s\n",
899 	    LEASE_VERSION, LEASE_IP_PREFIX, ip_ntop_buf,
900 	    LEASE_NEXTSERVER_PREFIX, nextserver_ntop_buf, LEASE_BOOTFILE_PREFIX,
901 	    imsg->file, LEASE_HOSTNAME_PREFIX, imsg->hostname,
902 	    LEASE_DOMAIN_PREFIX, imsg->domainname);
903 	if ( len == -1 || (size_t) len >= sizeof(lease_buf)) {
904 		log_warnx("%s: failed to encode lease for %s", __func__,
905 		    ip_ntop_buf);
906 		return;
907 	}
908 
909 	if ((fd = mkstemp(tmpl)) == -1) {
910 		log_warn("%s: mkstemp", __func__);
911 		return;
912 	}
913 
914 	if (write(fd, lease_buf, len) < len)
915 		goto err;
916 
917 	if (fchmod(fd, 0644) == -1)
918 		goto err;
919 
920 	if (close(fd) == -1)
921 		goto err;
922 	fd = -1;
923 
924 	if (rename(tmpl, lease_file_buf) == -1)
925 		goto err;
926 	return;
927  err:
928 	log_warn("%s", __func__);
929 	if (fd != -1)
930 		close(fd);
931 	unlink(tmpl);
932 }
933 
934 void
935 deconfigure_interface(struct imsg_configure_interface *imsg)
936 {
937 	struct ifaliasreq	 ifaliasreq;
938 	struct sockaddr_in	*req_sin_addr;
939 
940 	memset(&ifaliasreq, 0, sizeof(ifaliasreq));
941 
942 #if 0
943 	/*
944 	 * When two default routes have the same gateway the kernel always
945 	 * deletes the first which might be the wrong one. When we then
946 	 * deconfigure the IP address from the interface the kernel deletes
947 	 * all routes pointing out that interface and we end up with no
948 	 * default.
949 	 * This can happen with a wired & wireless interface on the same
950 	 * layer 2 network and the user issues ifconfig $WIFI inet -autoconf.
951 	 * Work around this issue by not deleting the default route and let
952 	 * the kernel handle it when we remove the IP address a few lines
953 	 * down.
954 	 */
955 	if (imsg->routes_len > 0)
956 		configure_routes(RTM_DELETE, imsg);
957 #endif
958 
959 	if (if_indextoname(imsg->if_index, ifaliasreq.ifra_name) == NULL) {
960 		log_warnx("%s: cannot find interface %d", __func__,
961 		    imsg->if_index);
962 		return;
963 	}
964 
965 	log_debug("%s %s", __func__, ifaliasreq.ifra_name);
966 
967 	req_sin_addr = (struct sockaddr_in *)&ifaliasreq.ifra_addr;
968 	req_sin_addr->sin_family = AF_INET;
969 	req_sin_addr->sin_len = sizeof(*req_sin_addr);
970 
971 	req_sin_addr->sin_addr = imsg->addr;
972 	if (ioctl(ioctl_sock, SIOCDIFADDR, &ifaliasreq) == -1) {
973 		if (errno != EADDRNOTAVAIL)
974 			log_warn("SIOCDIFADDR");
975 	}
976 }
977 
978 void
979 configure_routes(uint8_t rtm_type, struct imsg_configure_interface *imsg)
980 {
981 	struct sockaddr_in	 dst, mask, gw, ifa;
982 	in_addr_t		 addrnet, gwnet;
983 	int			 i;
984 
985 	memset(&ifa, 0, sizeof(ifa));
986 	ifa.sin_family = AF_INET;
987 	ifa.sin_len = sizeof(ifa);
988 	ifa.sin_addr = imsg->addr;
989 
990 	memset(&dst, 0, sizeof(dst));
991 	dst.sin_family = AF_INET;
992 	dst.sin_len = sizeof(dst);
993 
994 	memset(&mask, 0, sizeof(mask));
995 	mask.sin_family = AF_INET;
996 	mask.sin_len = sizeof(mask);
997 
998 	memset(&gw, 0, sizeof(gw));
999 	gw.sin_family = AF_INET;
1000 	gw.sin_len = sizeof(gw);
1001 
1002 	addrnet = imsg->addr.s_addr & imsg->mask.s_addr;
1003 
1004 	for (i = 0; i < imsg->routes_len; i++) {
1005 		dst.sin_addr = imsg->routes[i].dst;
1006 		mask.sin_addr = imsg->routes[i].mask;
1007 		gw.sin_addr = imsg->routes[i].gw;
1008 
1009 		if (gw.sin_addr.s_addr == INADDR_ANY) {
1010 			/* direct route */
1011 			configure_route(rtm_type, imsg->if_index,
1012 			    imsg->rdomain, &dst, &mask, &ifa, NULL,
1013 			    RTF_CLONING);
1014 		} else if (mask.sin_addr.s_addr == INADDR_ANY) {
1015 			/* default route */
1016 			gwnet =  gw.sin_addr.s_addr & imsg->mask.s_addr;
1017 			if (addrnet != gwnet) {
1018 				/*
1019 				 * The gateway for the default route is outside
1020 				 * the configured prefix. Install a direct
1021 				 * cloning route for the gateway to make the
1022 				 * default route reachable.
1023 				 */
1024 				mask.sin_addr.s_addr = 0xffffffff;
1025 				configure_route(rtm_type, imsg->if_index,
1026 				    imsg->rdomain, &gw, &mask, &ifa, NULL,
1027 				    RTF_CLONING);
1028 				mask.sin_addr = imsg->routes[i].mask;
1029 			}
1030 
1031 			if (gw.sin_addr.s_addr == ifa.sin_addr.s_addr) {
1032 				/* directly connected default */
1033 				configure_route(rtm_type, imsg->if_index,
1034 				    imsg->rdomain, &dst, &mask, &gw, NULL, 0);
1035 			} else {
1036 				/* default route via gateway */
1037 				configure_route(rtm_type, imsg->if_index,
1038 				    imsg->rdomain, &dst, &mask, &gw, &ifa,
1039 				    RTF_GATEWAY);
1040 			}
1041 		} else {
1042 			/* non-default via gateway */
1043 			configure_route(rtm_type, imsg->if_index, imsg->rdomain,
1044 			    &dst, &mask, &gw, NULL, RTF_GATEWAY);
1045 		}
1046 	}
1047 }
1048 
1049 #define	ROUNDUP(a)	\
1050     (((a) & (sizeof(long) - 1)) ? (1 + ((a) | (sizeof(long) - 1))) : (a))
1051 void
1052 configure_route(uint8_t rtm_type, uint32_t if_index, int rdomain, struct
1053     sockaddr_in *dst, struct sockaddr_in *mask, struct sockaddr_in *gw,
1054     struct sockaddr_in *ifa, int rtm_flags)
1055 {
1056 	struct rt_msghdr		 rtm;
1057 	struct sockaddr_dl		 ifp;
1058 	struct sockaddr_rtlabel		 rl;
1059 	struct iovec			 iov[14];
1060 	long				 pad = 0;
1061 	int				 iovcnt = 0, padlen;
1062 
1063 	memset(&rtm, 0, sizeof(rtm));
1064 
1065 	rtm.rtm_version = RTM_VERSION;
1066 	rtm.rtm_type = rtm_type;
1067 	rtm.rtm_msglen = sizeof(rtm);
1068 	rtm.rtm_index = if_index;
1069 	rtm.rtm_tableid = rdomain;
1070 	rtm.rtm_seq = ++rtm_seq;
1071 	rtm.rtm_priority = RTP_NONE;
1072 	rtm.rtm_addrs = RTA_DST | RTA_GATEWAY | RTA_NETMASK | RTA_IFP |
1073 	    RTA_LABEL;
1074 	rtm.rtm_flags = RTF_UP | RTF_STATIC | RTF_MPATH | rtm_flags;
1075 
1076 	if (ifa)
1077 		rtm.rtm_addrs |= RTA_IFA;
1078 
1079 	iov[iovcnt].iov_base = &rtm;
1080 	iov[iovcnt++].iov_len = sizeof(rtm);
1081 
1082 	iov[iovcnt].iov_base = dst;
1083 	iov[iovcnt++].iov_len = dst->sin_len;
1084 	rtm.rtm_msglen += dst->sin_len;
1085 	padlen = ROUNDUP(dst->sin_len) - dst->sin_len;
1086 	if (padlen > 0) {
1087 		iov[iovcnt].iov_base = &pad;
1088 		iov[iovcnt++].iov_len = padlen;
1089 		rtm.rtm_msglen += padlen;
1090 	}
1091 
1092 	iov[iovcnt].iov_base = gw;
1093 	iov[iovcnt++].iov_len = gw->sin_len;
1094 	rtm.rtm_msglen += gw->sin_len;
1095 	padlen = ROUNDUP(gw->sin_len) - gw->sin_len;
1096 	if (padlen > 0) {
1097 		iov[iovcnt].iov_base = &pad;
1098 		iov[iovcnt++].iov_len = padlen;
1099 		rtm.rtm_msglen += padlen;
1100 	}
1101 
1102 	iov[iovcnt].iov_base = mask;
1103 	iov[iovcnt++].iov_len = mask->sin_len;
1104 	rtm.rtm_msglen += mask->sin_len;
1105 	padlen = ROUNDUP(mask->sin_len) - mask->sin_len;
1106 	if (padlen > 0) {
1107 		iov[iovcnt].iov_base = &pad;
1108 		iov[iovcnt++].iov_len = padlen;
1109 		rtm.rtm_msglen += padlen;
1110 	}
1111 
1112 	memset(&ifp, 0, sizeof(ifp));
1113 	ifp.sdl_len = sizeof(struct sockaddr_dl);
1114 	ifp.sdl_family = AF_LINK;
1115 	ifp.sdl_index = if_index;
1116 	iov[iovcnt].iov_base = &ifp;
1117 	iov[iovcnt++].iov_len = sizeof(ifp);
1118 	rtm.rtm_msglen += sizeof(ifp);
1119 	padlen = ROUNDUP(sizeof(ifp)) - sizeof(ifp);
1120 	if (padlen > 0) {
1121 		iov[iovcnt].iov_base = &pad;
1122 		iov[iovcnt++].iov_len = padlen;
1123 		rtm.rtm_msglen += padlen;
1124 	}
1125 
1126 	if (ifa) {
1127 		iov[iovcnt].iov_base = ifa;
1128 		iov[iovcnt++].iov_len = ifa->sin_len;
1129 		rtm.rtm_msglen += ifa->sin_len;
1130 		padlen = ROUNDUP(ifa->sin_len) - ifa->sin_len;
1131 		if (padlen > 0) {
1132 			iov[iovcnt].iov_base = &pad;
1133 			iov[iovcnt++].iov_len = padlen;
1134 			rtm.rtm_msglen += padlen;
1135 		}
1136 	}
1137 
1138 	memset(&rl, 0, sizeof(rl));
1139 	rl.sr_len = sizeof(rl);
1140 	rl.sr_family = AF_UNSPEC;
1141 	(void)snprintf(rl.sr_label, sizeof(rl.sr_label), "%s",
1142 	    DHCPLEASED_RTA_LABEL);
1143 	iov[iovcnt].iov_base = &rl;
1144 	iov[iovcnt++].iov_len = sizeof(rl);
1145 	rtm.rtm_msglen += sizeof(rl);
1146 	padlen = ROUNDUP(sizeof(rl)) - sizeof(rl);
1147 	if (padlen > 0) {
1148 		iov[iovcnt].iov_base = &pad;
1149 		iov[iovcnt++].iov_len = padlen;
1150 		rtm.rtm_msglen += padlen;
1151 	}
1152 
1153 	if (writev(routesock, iov, iovcnt) == -1) {
1154 		if (errno != EEXIST)
1155 			log_warn("failed to send route message");
1156 	}
1157 }
1158 
1159 #ifndef	SMALL
1160 const char*
1161 sin_to_str(struct sockaddr_in *sin)
1162 {
1163 	static char hbuf[NI_MAXHOST];
1164 	int error;
1165 
1166 	error = getnameinfo((struct sockaddr *)sin, sin->sin_len, hbuf,
1167 	    sizeof(hbuf), NULL, 0, NI_NUMERICHOST | NI_NUMERICSERV);
1168 	if (error) {
1169 		log_warnx("%s", gai_strerror(error));
1170 		strlcpy(hbuf, "unknown", sizeof(hbuf));
1171 	}
1172 	return hbuf;
1173 }
1174 #endif	/* SMALL */
1175 
1176 void
1177 open_bpfsock(uint32_t if_index)
1178 {
1179 	int		 bpfsock;
1180 	char		 ifname[IF_NAMESIZE];
1181 
1182 	if (if_indextoname(if_index, ifname) == NULL) {
1183 		log_warnx("%s: cannot find interface %d", __func__, if_index);
1184 		return;
1185 	}
1186 
1187 	if ((bpfsock = get_bpf_sock(ifname)) == -1)
1188 		return;
1189 
1190 	main_imsg_compose_frontend(IMSG_BPFSOCK, bpfsock, &if_index,
1191 	    sizeof(if_index));
1192 }
1193 
1194 void
1195 propose_rdns(struct imsg_propose_rdns *rdns)
1196 {
1197 	struct rt_msghdr		 rtm;
1198 	struct sockaddr_rtdns		 rtdns;
1199 	struct iovec			 iov[3];
1200 	long				 pad = 0;
1201 	int				 iovcnt = 0, padlen;
1202 
1203 	memset(&rtm, 0, sizeof(rtm));
1204 
1205 	rtm.rtm_version = RTM_VERSION;
1206 	rtm.rtm_type = RTM_PROPOSAL;
1207 	rtm.rtm_msglen = sizeof(rtm);
1208 	rtm.rtm_tableid = rdns->rdomain;
1209 	rtm.rtm_index = rdns->if_index;
1210 	rtm.rtm_seq = ++rtm_seq;
1211 	rtm.rtm_priority = RTP_PROPOSAL_DHCLIENT;
1212 	rtm.rtm_addrs = RTA_DNS;
1213 	rtm.rtm_flags = RTF_UP;
1214 
1215 	iov[iovcnt].iov_base = &rtm;
1216 	iov[iovcnt++].iov_len = sizeof(rtm);
1217 
1218 	memset(&rtdns, 0, sizeof(rtdns));
1219 	rtdns.sr_family = AF_INET;
1220 	rtdns.sr_len = 2 + rdns->rdns_count * sizeof(struct in_addr);
1221 	memcpy(rtdns.sr_dns, rdns->rdns, rtdns.sr_len - 2);
1222 
1223 	iov[iovcnt].iov_base = &rtdns;
1224 	iov[iovcnt++].iov_len = sizeof(rtdns);
1225 	rtm.rtm_msglen += sizeof(rtdns);
1226 	padlen = ROUNDUP(sizeof(rtdns)) - sizeof(rtdns);
1227 	if (padlen > 0) {
1228 		iov[iovcnt].iov_base = &pad;
1229 		iov[iovcnt++].iov_len = padlen;
1230 		rtm.rtm_msglen += padlen;
1231 	}
1232 
1233 	if (writev(routesock, iov, iovcnt) == -1)
1234 		log_warn("failed to propose nameservers");
1235 }
1236 
1237 void
1238 read_lease_file(struct imsg_ifinfo *imsg_ifinfo)
1239 {
1240 	int	 len, fd;
1241 	char	 if_name[IF_NAMESIZE];
1242 	char	 lease_file_buf[sizeof(_PATH_LEASE) + IF_NAMESIZE];
1243 
1244 	if (no_lease_files)
1245 		return;
1246 
1247 	memset(imsg_ifinfo->lease, 0, sizeof(imsg_ifinfo->lease));
1248 
1249 	if (if_indextoname(imsg_ifinfo->if_index, if_name) == NULL) {
1250 		log_warnx("%s: cannot find interface %d", __func__,
1251 		    imsg_ifinfo->if_index);
1252 		return;
1253 	}
1254 
1255 	len = snprintf(lease_file_buf, sizeof(lease_file_buf), "%s%s",
1256 	    _PATH_LEASE, if_name);
1257 	if ( len == -1 || (size_t) len >= sizeof(lease_file_buf)) {
1258 		log_warnx("%s: failed to encode lease path for %s", __func__,
1259 		    if_name);
1260 		return;
1261 	}
1262 
1263 	if ((fd = open(lease_file_buf, O_RDONLY)) == -1)
1264 		return;
1265 
1266 	/* no need for error handling, we'll just do a DHCP discover */
1267 	read(fd, imsg_ifinfo->lease, sizeof(imsg_ifinfo->lease) - 1);
1268 	close(fd);
1269 }
1270 
1271 #ifndef SMALL
1272 void
1273 merge_config(struct dhcpleased_conf *conf, struct dhcpleased_conf *xconf)
1274 {
1275 	struct iface_conf	*iface_conf;
1276 
1277 	/* Remove & discard existing interfaces. */
1278 	while ((iface_conf = SIMPLEQ_FIRST(&conf->iface_list)) != NULL) {
1279 		SIMPLEQ_REMOVE_HEAD(&conf->iface_list, entry);
1280 		free(iface_conf->vc_id);
1281 		free(iface_conf->c_id);
1282 		free(iface_conf->h_name);
1283 		free(iface_conf);
1284 	}
1285 
1286 	/* Add new interfaces. */
1287 	SIMPLEQ_CONCAT(&conf->iface_list, &xconf->iface_list);
1288 
1289 	free(xconf);
1290 }
1291 
1292 struct dhcpleased_conf *
1293 config_new_empty(void)
1294 {
1295 	struct dhcpleased_conf	*xconf;
1296 
1297 	xconf = calloc(1, sizeof(*xconf));
1298 	if (xconf == NULL)
1299 		fatal(NULL);
1300 
1301 	SIMPLEQ_INIT(&xconf->iface_list);
1302 
1303 	return (xconf);
1304 }
1305 
1306 void
1307 config_clear(struct dhcpleased_conf *conf)
1308 {
1309 	struct dhcpleased_conf	*xconf;
1310 
1311 	/* Merge current config with an empty config. */
1312 	xconf = config_new_empty();
1313 	merge_config(conf, xconf);
1314 
1315 	free(conf);
1316 }
1317 
1318 #define	I2S(x) case x: return #x
1319 
1320 const char*
1321 i2s(uint32_t type)
1322 {
1323 	static char	unknown[sizeof("IMSG_4294967295")];
1324 
1325 	switch (type) {
1326 	I2S(IMSG_NONE);
1327 	I2S(IMSG_CTL_LOG_VERBOSE);
1328 	I2S(IMSG_CTL_SHOW_INTERFACE_INFO);
1329 	I2S(IMSG_CTL_SEND_REQUEST);
1330 	I2S(IMSG_CTL_RELOAD);
1331 	I2S(IMSG_CTL_END);
1332 	I2S(IMSG_RECONF_CONF);
1333 	I2S(IMSG_RECONF_IFACE);
1334 	I2S(IMSG_RECONF_VC_ID);
1335 	I2S(IMSG_RECONF_C_ID);
1336 	I2S(IMSG_RECONF_H_NAME);
1337 	I2S(IMSG_RECONF_END);
1338 	I2S(IMSG_SEND_DISCOVER);
1339 	I2S(IMSG_SEND_REQUEST);
1340 	I2S(IMSG_SOCKET_IPC);
1341 	I2S(IMSG_OPEN_BPFSOCK);
1342 	I2S(IMSG_BPFSOCK);
1343 	I2S(IMSG_UDPSOCK);
1344 	I2S(IMSG_CLOSE_UDPSOCK);
1345 	I2S(IMSG_ROUTESOCK);
1346 	I2S(IMSG_CONTROLFD);
1347 	I2S(IMSG_STARTUP);
1348 	I2S(IMSG_UPDATE_IF);
1349 	I2S(IMSG_REMOVE_IF);
1350 	I2S(IMSG_DHCP);
1351 	I2S(IMSG_CONFIGURE_INTERFACE);
1352 	I2S(IMSG_DECONFIGURE_INTERFACE);
1353 	I2S(IMSG_PROPOSE_RDNS);
1354 	I2S(IMSG_WITHDRAW_RDNS);
1355 	I2S(IMSG_WITHDRAW_ROUTES);
1356 	I2S(IMSG_REPROPOSE_RDNS);
1357 	I2S(IMSG_REQUEST_REBOOT);
1358 	default:
1359 		snprintf(unknown, sizeof(unknown), "IMSG_%u", type);
1360 		return unknown;
1361 	}
1362 }
1363 #undef	I2S
1364 
1365 #endif /* SMALL */
1366