xref: /freebsd/contrib/unbound/daemon/unbound.c (revision 595e514d0df2bac5b813d35f83e32875dbf16a83)
1 /*
2  * daemon/unbound.c - main program for unbound DNS resolver daemon.
3  *
4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
27  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33  * POSSIBILITY OF SUCH DAMAGE.
34  *
35  */
36 
37 /**
38  * \file
39  *
40  * Main program to start the DNS resolver daemon.
41  */
42 
43 #include "config.h"
44 #ifdef HAVE_GETOPT_H
45 #include <getopt.h>
46 #endif
47 #include <sys/time.h>
48 #include "util/log.h"
49 #include "daemon/daemon.h"
50 #include "daemon/remote.h"
51 #include "util/config_file.h"
52 #include "util/storage/slabhash.h"
53 #include "services/listen_dnsport.h"
54 #include "services/cache/rrset.h"
55 #include "services/cache/infra.h"
56 #include "util/data/msgreply.h"
57 #include "util/module.h"
58 #include "util/net_help.h"
59 #include <signal.h>
60 #include <fcntl.h>
61 #include <openssl/crypto.h>
62 #ifdef HAVE_PWD_H
63 #include <pwd.h>
64 #endif
65 #ifdef HAVE_GRP_H
66 #include <grp.h>
67 #endif
68 
69 #ifdef HAVE_SYS_RESOURCE_H
70 #include <sys/resource.h>
71 #endif
72 #ifdef HAVE_LOGIN_CAP_H
73 #include <login_cap.h>
74 #endif
75 
76 #ifdef USE_MINI_EVENT
77 #  ifdef USE_WINSOCK
78 #    include "util/winsock_event.h"
79 #  else
80 #    include "util/mini_event.h"
81 #  endif
82 #else
83 #  include <event.h>
84 #endif
85 
86 #ifdef UB_ON_WINDOWS
87 #  include "winrc/win_svc.h"
88 #endif
89 
90 #ifdef HAVE_NSS
91 /* nss3 */
92 #  include "nss.h"
93 #endif
94 
95 /** global debug value to keep track of heap memory allocation */
96 void* unbound_start_brk = 0;
97 
98 #if !defined(HAVE_EVENT_BASE_GET_METHOD) && (defined(HAVE_EV_LOOP) || defined(HAVE_EV_DEFAULT_LOOP))
99 static const char* ev_backend2str(int b)
100 {
101 	switch(b) {
102 	case EVBACKEND_SELECT:	return "select";
103 	case EVBACKEND_POLL:	return "poll";
104 	case EVBACKEND_EPOLL:	return "epoll";
105 	case EVBACKEND_KQUEUE:	return "kqueue";
106 	case EVBACKEND_DEVPOLL: return "devpoll";
107 	case EVBACKEND_PORT:	return "evport";
108 	}
109 	return "unknown";
110 }
111 #endif
112 
113 /** get the event system in use */
114 static void get_event_sys(const char** n, const char** s, const char** m)
115 {
116 #ifdef USE_WINSOCK
117 	*n = "event";
118 	*s = "winsock";
119 	*m = "WSAWaitForMultipleEvents";
120 #elif defined(USE_MINI_EVENT)
121 	*n = "mini-event";
122 	*s = "internal";
123 	*m = "select";
124 #else
125 	struct event_base* b;
126 	*s = event_get_version();
127 #  ifdef HAVE_EVENT_BASE_GET_METHOD
128 	*n = "libevent";
129 	b = event_base_new();
130 	*m = event_base_get_method(b);
131 #  elif defined(HAVE_EV_LOOP) || defined(HAVE_EV_DEFAULT_LOOP)
132 	*n = "libev";
133 	b = (struct event_base*)ev_default_loop(EVFLAG_AUTO);
134 	*m = ev_backend2str(ev_backend((struct ev_loop*)b));
135 #  else
136 	*n = "unknown";
137 	*m = "not obtainable";
138 	b = NULL;
139 #  endif
140 #  ifdef HAVE_EVENT_BASE_FREE
141 	event_base_free(b);
142 #  endif
143 #endif
144 }
145 
146 /** print usage. */
147 static void usage()
148 {
149 	const char** m;
150 	const char *evnm="event", *evsys="", *evmethod="";
151 	printf("usage:  unbound [options]\n");
152 	printf("	start unbound daemon DNS resolver.\n");
153 	printf("-h	this help\n");
154 	printf("-c file	config file to read instead of %s\n", CONFIGFILE);
155 	printf("	file format is described in unbound.conf(5).\n");
156 	printf("-d	do not fork into the background.\n");
157 	printf("-v	verbose (more times to increase verbosity)\n");
158 #ifdef UB_ON_WINDOWS
159 	printf("-w opt	windows option: \n");
160 	printf("   	install, remove - manage the services entry\n");
161 	printf("   	service - used to start from services control panel\n");
162 #endif
163 	printf("Version %s\n", PACKAGE_VERSION);
164 	get_event_sys(&evnm, &evsys, &evmethod);
165 	printf("linked libs: %s %s (it uses %s), ldns %s, %s\n",
166 		evnm, evsys, evmethod, ldns_version(),
167 #ifdef HAVE_SSL
168 		SSLeay_version(SSLEAY_VERSION)
169 #elif defined(HAVE_NSS)
170 		NSS_GetVersion()
171 #endif
172 		);
173 	printf("linked modules:");
174 	for(m = module_list_avail(); *m; m++)
175 		printf(" %s", *m);
176 	printf("\n");
177 	printf("configured for %s on %s with options:%s\n",
178 		CONFIGURE_TARGET, CONFIGURE_DATE, CONFIGURE_BUILD_WITH);
179 	printf("BSD licensed, see LICENSE in source package for details.\n");
180 	printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
181 }
182 
183 #ifndef unbound_testbound
184 int replay_var_compare(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
185 {
186         log_assert(0);
187         return 0;
188 }
189 #endif
190 
191 /** check file descriptor count */
192 static void
193 checkrlimits(struct config_file* cfg)
194 {
195 #ifdef HAVE_GETRLIMIT
196 	/* list has number of ports to listen to, ifs number addresses */
197 	int list = ((cfg->do_udp?1:0) + (cfg->do_tcp?1 +
198 			(int)cfg->incoming_num_tcp:0));
199 	size_t listen_ifs = (size_t)(cfg->num_ifs==0?
200 		((cfg->do_ip4 && !cfg->if_automatic?1:0) +
201 		 (cfg->do_ip6?1:0)):cfg->num_ifs);
202 	size_t listen_num = list*listen_ifs;
203 	size_t outudpnum = (size_t)cfg->outgoing_num_ports;
204 	size_t outtcpnum = cfg->outgoing_num_tcp;
205 	size_t misc = 4; /* logfile, pidfile, stdout... */
206 	size_t perthread_noudp = listen_num + outtcpnum +
207 		2/*cmdpipe*/ + 2/*libevent*/ + misc;
208 	size_t perthread = perthread_noudp + outudpnum;
209 
210 #if !defined(HAVE_PTHREAD) && !defined(HAVE_SOLARIS_THREADS)
211 	int numthread = 1; /* it forks */
212 #else
213 	int numthread = (cfg->num_threads?cfg->num_threads:1);
214 #endif
215 	size_t total = numthread * perthread + misc;
216 	size_t avail;
217 	struct rlimit rlim;
218 
219 	if(total > 1024 &&
220 		strncmp(event_get_version(), "mini-event", 10) == 0) {
221 		log_warn("too many file descriptors requested. The builtin"
222 			"mini-event cannot handle more than 1024. Config "
223 			"for less fds or compile with libevent");
224 		if(numthread*perthread_noudp+15 > 1024)
225 			fatal_exit("too much tcp. not enough fds.");
226 		cfg->outgoing_num_ports = (int)((1024
227 			- numthread*perthread_noudp
228 			- 10 /* safety margin */) /numthread);
229 		log_warn("continuing with less udp ports: %u",
230 			cfg->outgoing_num_ports);
231 		total = 1024;
232 	}
233 	if(perthread > 64 &&
234 		strncmp(event_get_version(), "winsock-event", 13) == 0) {
235 		log_err("too many file descriptors requested. The winsock"
236 			" event handler cannot handle more than 64 per "
237 			" thread. Config for less fds");
238 		if(perthread_noudp+2 > 64)
239 			fatal_exit("too much tcp. not enough fds.");
240 		cfg->outgoing_num_ports = (int)((64
241 			- perthread_noudp
242 			- 2/* safety margin */));
243 		log_warn("continuing with less udp ports: %u",
244 			cfg->outgoing_num_ports);
245 		total = numthread*(perthread_noudp+
246 			(size_t)cfg->outgoing_num_ports)+misc;
247 	}
248 	if(getrlimit(RLIMIT_NOFILE, &rlim) < 0) {
249 		log_warn("getrlimit: %s", strerror(errno));
250 		return;
251 	}
252 	if(rlim.rlim_cur == (rlim_t)RLIM_INFINITY)
253 		return;
254 	if((size_t)rlim.rlim_cur < total) {
255 		avail = (size_t)rlim.rlim_cur;
256 		rlim.rlim_cur = (rlim_t)(total + 10);
257 		rlim.rlim_max = (rlim_t)(total + 10);
258 #ifdef HAVE_SETRLIMIT
259 		if(setrlimit(RLIMIT_NOFILE, &rlim) < 0) {
260 			log_warn("setrlimit: %s", strerror(errno));
261 #else
262 		if(1) {
263 #endif
264 			log_warn("cannot increase max open fds from %u to %u",
265 				(unsigned)avail, (unsigned)total+10);
266 			/* check that calculation below does not underflow,
267 			 * with 15 as margin */
268 			if(numthread*perthread_noudp+15 > avail)
269 				fatal_exit("too much tcp. not enough fds.");
270 			cfg->outgoing_num_ports = (int)((avail
271 				- numthread*perthread_noudp
272 				- 10 /* safety margin */) /numthread);
273 			log_warn("continuing with less udp ports: %u",
274 				cfg->outgoing_num_ports);
275 			log_warn("increase ulimit or decrease threads, "
276 				"ports in config to remove this warning");
277 			return;
278 		}
279 		log_warn("increased limit(open files) from %u to %u",
280 			(unsigned)avail, (unsigned)total+10);
281 	}
282 #else
283 	(void)cfg;
284 #endif /* HAVE_GETRLIMIT */
285 }
286 
287 /** set verbosity, check rlimits, cache settings */
288 static void
289 apply_settings(struct daemon* daemon, struct config_file* cfg,
290 	int cmdline_verbose)
291 {
292 	/* apply if they have changed */
293 	verbosity = cmdline_verbose + cfg->verbosity;
294 	daemon_apply_cfg(daemon, cfg);
295 	checkrlimits(cfg);
296 }
297 
298 #ifdef HAVE_KILL
299 /** Read existing pid from pidfile.
300  * @param file: file name of pid file.
301  * @return: the pid from the file or -1 if none.
302  */
303 static pid_t
304 readpid (const char* file)
305 {
306 	int fd;
307 	pid_t pid;
308 	char pidbuf[32];
309 	char* t;
310 	ssize_t l;
311 
312 	if ((fd = open(file, O_RDONLY)) == -1) {
313 		if(errno != ENOENT)
314 			log_err("Could not read pidfile %s: %s",
315 				file, strerror(errno));
316 		return -1;
317 	}
318 
319 	if (((l = read(fd, pidbuf, sizeof(pidbuf)))) == -1) {
320 		if(errno != ENOENT)
321 			log_err("Could not read pidfile %s: %s",
322 				file, strerror(errno));
323 		close(fd);
324 		return -1;
325 	}
326 
327 	close(fd);
328 
329 	/* Empty pidfile means no pidfile... */
330 	if (l == 0) {
331 		return -1;
332 	}
333 
334 	pidbuf[sizeof(pidbuf)-1] = 0;
335 	pid = (pid_t)strtol(pidbuf, &t, 10);
336 
337 	if (*t && *t != '\n') {
338 		return -1;
339 	}
340 	return pid;
341 }
342 
343 /** write pid to file.
344  * @param pidfile: file name of pid file.
345  * @param pid: pid to write to file.
346  */
347 static void
348 writepid (const char* pidfile, pid_t pid)
349 {
350 	FILE* f;
351 
352 	if ((f = fopen(pidfile, "w")) ==  NULL ) {
353 		log_err("cannot open pidfile %s: %s",
354 			pidfile, strerror(errno));
355 		return;
356 	}
357 	if(fprintf(f, "%lu\n", (unsigned long)pid) < 0) {
358 		log_err("cannot write to pidfile %s: %s",
359 			pidfile, strerror(errno));
360 	}
361 	fclose(f);
362 }
363 
364 /**
365  * check old pid file.
366  * @param pidfile: the file name of the pid file.
367  * @param inchroot: if pidfile is inchroot and we can thus expect to
368  *	be able to delete it.
369  */
370 static void
371 checkoldpid(char* pidfile, int inchroot)
372 {
373 	pid_t old;
374 	if((old = readpid(pidfile)) != -1) {
375 		/* see if it is still alive */
376 		if(kill(old, 0) == 0 || errno == EPERM)
377 			log_warn("unbound is already running as pid %u.",
378 				(unsigned)old);
379 		else	if(inchroot)
380 			log_warn("did not exit gracefully last time (%u)",
381 				(unsigned)old);
382 	}
383 }
384 #endif /* HAVE_KILL */
385 
386 /** detach from command line */
387 static void
388 detach(void)
389 {
390 #if defined(HAVE_DAEMON) && !defined(DEPRECATED_DAEMON)
391 	/* use POSIX daemon(3) function */
392 	if(daemon(1, 0) != 0)
393 		fatal_exit("daemon failed: %s", strerror(errno));
394 #else /* no HAVE_DAEMON */
395 #ifdef HAVE_FORK
396 	int fd;
397 	/* Take off... */
398 	switch (fork()) {
399 		case 0:
400 			break;
401 		case -1:
402 			fatal_exit("fork failed: %s", strerror(errno));
403 		default:
404 			/* exit interactive session */
405 			exit(0);
406 	}
407 	/* detach */
408 #ifdef HAVE_SETSID
409 	if(setsid() == -1)
410 		fatal_exit("setsid() failed: %s", strerror(errno));
411 #endif
412 	if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
413 		(void)dup2(fd, STDIN_FILENO);
414 		(void)dup2(fd, STDOUT_FILENO);
415 		(void)dup2(fd, STDERR_FILENO);
416 		if (fd > 2)
417 			(void)close(fd);
418 	}
419 #endif /* HAVE_FORK */
420 #endif /* HAVE_DAEMON */
421 }
422 
423 /** daemonize, drop user priviliges and chroot if needed */
424 static void
425 perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
426 	const char** cfgfile)
427 {
428 #ifdef HAVE_GETPWNAM
429 	struct passwd *pwd = NULL;
430 	uid_t uid;
431 	gid_t gid;
432 	/* initialize, but not to 0 (root) */
433 	memset(&uid, 112, sizeof(uid));
434 	memset(&gid, 112, sizeof(gid));
435 	log_assert(cfg);
436 
437 	if(cfg->username && cfg->username[0]) {
438 		if((pwd = getpwnam(cfg->username)) == NULL)
439 			fatal_exit("user '%s' does not exist.", cfg->username);
440 		uid = pwd->pw_uid;
441 		gid = pwd->pw_gid;
442 		/* endpwent below, in case we need pwd for setusercontext */
443 	}
444 #endif
445 
446 	/* init syslog (as root) if needed, before daemonize, otherwise
447 	 * a fork error could not be printed since daemonize closed stderr.*/
448 	if(cfg->use_syslog) {
449 		log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
450 	}
451 	/* if using a logfile, we cannot open it because the logfile would
452 	 * be created with the wrong permissions, we cannot chown it because
453 	 * we cannot chown system logfiles, so we do not open at all.
454 	 * So, using a logfile, the user does not see errors unless -d is
455 	 * given to unbound on the commandline. */
456 
457 	/* read ssl keys while superuser and outside chroot */
458 #ifdef HAVE_SSL
459 	if(!(daemon->rc = daemon_remote_create(cfg)))
460 		fatal_exit("could not set up remote-control");
461 	if(cfg->ssl_service_key && cfg->ssl_service_key[0]) {
462 		if(!(daemon->listen_sslctx = listen_sslctx_create(
463 			cfg->ssl_service_key, cfg->ssl_service_pem, NULL)))
464 			fatal_exit("could not set up listen SSL_CTX");
465 	}
466 	if(!(daemon->connect_sslctx = connect_sslctx_create(NULL, NULL, NULL)))
467 		fatal_exit("could not set up connect SSL_CTX");
468 #endif
469 
470 #ifdef HAVE_KILL
471 	/* check old pid file before forking */
472 	if(cfg->pidfile && cfg->pidfile[0]) {
473 		/* calculate position of pidfile */
474 		if(cfg->pidfile[0] == '/')
475 			daemon->pidfile = strdup(cfg->pidfile);
476 		else	daemon->pidfile = fname_after_chroot(cfg->pidfile,
477 				cfg, 1);
478 		if(!daemon->pidfile)
479 			fatal_exit("pidfile alloc: out of memory");
480 		checkoldpid(daemon->pidfile,
481 			/* true if pidfile is inside chrootdir, or nochroot */
482 			!(cfg->chrootdir && cfg->chrootdir[0]) ||
483 			(cfg->chrootdir && cfg->chrootdir[0] &&
484 			strncmp(daemon->pidfile, cfg->chrootdir,
485 				strlen(cfg->chrootdir))==0));
486 	}
487 #endif
488 
489 	/* daemonize because pid is needed by the writepid func */
490 	if(!debug_mode && cfg->do_daemonize) {
491 		detach();
492 	}
493 
494 	/* write new pidfile (while still root, so can be outside chroot) */
495 #ifdef HAVE_KILL
496 	if(cfg->pidfile && cfg->pidfile[0]) {
497 		writepid(daemon->pidfile, getpid());
498 		if(!(cfg->chrootdir && cfg->chrootdir[0]) ||
499 			(cfg->chrootdir && cfg->chrootdir[0] &&
500 			strncmp(daemon->pidfile, cfg->chrootdir,
501 			strlen(cfg->chrootdir))==0)) {
502 			/* delete of pidfile could potentially work,
503 			 * chown to get permissions */
504 			if(cfg->username && cfg->username[0]) {
505 			  if(chown(daemon->pidfile, uid, gid) == -1) {
506 				log_err("cannot chown %u.%u %s: %s",
507 					(unsigned)uid, (unsigned)gid,
508 					daemon->pidfile, strerror(errno));
509 			  }
510 			}
511 		}
512 	}
513 #else
514 	(void)daemon;
515 #endif
516 
517 	/* Set user context */
518 #ifdef HAVE_GETPWNAM
519 	if(cfg->username && cfg->username[0]) {
520 #ifdef HAVE_SETUSERCONTEXT
521 		/* setusercontext does initgroups, setuid, setgid, and
522 		 * also resource limits from login config, but we
523 		 * still call setresuid, setresgid to be sure to set all uid*/
524 		if(setusercontext(NULL, pwd, uid,
525 			LOGIN_SETALL & ~LOGIN_SETUSER & ~LOGIN_SETGROUP) != 0)
526 			log_warn("unable to setusercontext %s: %s",
527 				cfg->username, strerror(errno));
528 #endif /* HAVE_SETUSERCONTEXT */
529 	}
530 #endif /* HAVE_GETPWNAM */
531 
532 	/* box into the chroot */
533 #ifdef HAVE_CHROOT
534 	if(cfg->chrootdir && cfg->chrootdir[0]) {
535 		if(chdir(cfg->chrootdir)) {
536 			fatal_exit("unable to chdir to chroot %s: %s",
537 				cfg->chrootdir, strerror(errno));
538 		}
539 		verbose(VERB_QUERY, "chdir to %s", cfg->chrootdir);
540 		if(chroot(cfg->chrootdir))
541 			fatal_exit("unable to chroot to %s: %s",
542 				cfg->chrootdir, strerror(errno));
543 		if(chdir("/"))
544 			fatal_exit("unable to chdir to / in chroot %s: %s",
545 				cfg->chrootdir, strerror(errno));
546 		verbose(VERB_QUERY, "chroot to %s", cfg->chrootdir);
547 		if(strncmp(*cfgfile, cfg->chrootdir,
548 			strlen(cfg->chrootdir)) == 0)
549 			(*cfgfile) += strlen(cfg->chrootdir);
550 
551 		/* adjust stored pidfile for chroot */
552 		if(daemon->pidfile && daemon->pidfile[0] &&
553 			strncmp(daemon->pidfile, cfg->chrootdir,
554 			strlen(cfg->chrootdir))==0) {
555 			char* old = daemon->pidfile;
556 			daemon->pidfile = strdup(old+strlen(cfg->chrootdir));
557 			free(old);
558 			if(!daemon->pidfile)
559 				log_err("out of memory in pidfile adjust");
560 		}
561 		daemon->chroot = strdup(cfg->chrootdir);
562 		if(!daemon->chroot)
563 			log_err("out of memory in daemon chroot dir storage");
564 	}
565 #else
566 	(void)cfgfile;
567 #endif
568 	/* change to working directory inside chroot */
569 	if(cfg->directory && cfg->directory[0]) {
570 		char* dir = cfg->directory;
571 		if(cfg->chrootdir && cfg->chrootdir[0] &&
572 			strncmp(dir, cfg->chrootdir,
573 			strlen(cfg->chrootdir)) == 0)
574 			dir += strlen(cfg->chrootdir);
575 		if(dir[0]) {
576 			if(chdir(dir)) {
577 				fatal_exit("Could not chdir to %s: %s",
578 					dir, strerror(errno));
579 			}
580 			verbose(VERB_QUERY, "chdir to %s", dir);
581 		}
582 	}
583 
584 	/* drop permissions after chroot, getpwnam, pidfile, syslog done*/
585 #ifdef HAVE_GETPWNAM
586 	if(cfg->username && cfg->username[0]) {
587 #  ifdef HAVE_INITGROUPS
588 		if(initgroups(cfg->username, gid) != 0)
589 			log_warn("unable to initgroups %s: %s",
590 				cfg->username, strerror(errno));
591 #  endif /* HAVE_INITGROUPS */
592 		endpwent();
593 
594 #ifdef HAVE_SETRESGID
595 		if(setresgid(gid,gid,gid) != 0)
596 #elif defined(HAVE_SETREGID) && !defined(DARWIN_BROKEN_SETREUID)
597 		if(setregid(gid,gid) != 0)
598 #else /* use setgid */
599 		if(setgid(gid) != 0)
600 #endif /* HAVE_SETRESGID */
601 			fatal_exit("unable to set group id of %s: %s",
602 				cfg->username, strerror(errno));
603 #ifdef HAVE_SETRESUID
604 		if(setresuid(uid,uid,uid) != 0)
605 #elif defined(HAVE_SETREUID) && !defined(DARWIN_BROKEN_SETREUID)
606 		if(setreuid(uid,uid) != 0)
607 #else /* use setuid */
608 		if(setuid(uid) != 0)
609 #endif /* HAVE_SETRESUID */
610 			fatal_exit("unable to set user id of %s: %s",
611 				cfg->username, strerror(errno));
612 		verbose(VERB_QUERY, "drop user privileges, run as %s",
613 			cfg->username);
614 	}
615 #endif /* HAVE_GETPWNAM */
616 	/* file logging inited after chroot,chdir,setuid is done so that
617 	 * it would succeed on SIGHUP as well */
618 	if(!cfg->use_syslog)
619 		log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
620 }
621 
622 /**
623  * Run the daemon.
624  * @param cfgfile: the config file name.
625  * @param cmdline_verbose: verbosity resulting from commandline -v.
626  *    These increase verbosity as specified in the config file.
627  * @param debug_mode: if set, do not daemonize.
628  */
629 static void
630 run_daemon(const char* cfgfile, int cmdline_verbose, int debug_mode)
631 {
632 	struct config_file* cfg = NULL;
633 	struct daemon* daemon = NULL;
634 	int done_setup = 0;
635 
636 	if(!(daemon = daemon_init()))
637 		fatal_exit("alloc failure");
638 	while(!daemon->need_to_exit) {
639 		if(done_setup)
640 			verbose(VERB_OPS, "Restart of %s.", PACKAGE_STRING);
641 		else	verbose(VERB_OPS, "Start of %s.", PACKAGE_STRING);
642 
643 		/* config stuff */
644 		if(!(cfg = config_create()))
645 			fatal_exit("Could not alloc config defaults");
646 		if(!config_read(cfg, cfgfile, daemon->chroot)) {
647 			if(errno != ENOENT)
648 				fatal_exit("Could not read config file: %s",
649 					cfgfile);
650 			log_warn("Continuing with default config settings");
651 		}
652 		apply_settings(daemon, cfg, cmdline_verbose);
653 
654 		/* prepare */
655 		if(!daemon_open_shared_ports(daemon))
656 			fatal_exit("could not open ports");
657 		if(!done_setup) {
658 			perform_setup(daemon, cfg, debug_mode, &cfgfile);
659 			done_setup = 1;
660 		} else {
661 			/* reopen log after HUP to facilitate log rotation */
662 			if(!cfg->use_syslog)
663 				log_init(cfg->logfile, 0, cfg->chrootdir);
664 		}
665 		/* work */
666 		daemon_fork(daemon);
667 
668 		/* clean up for restart */
669 		verbose(VERB_ALGO, "cleanup.");
670 		daemon_cleanup(daemon);
671 		config_delete(cfg);
672 	}
673 	verbose(VERB_ALGO, "Exit cleanup.");
674 	/* this unlink may not work if the pidfile is located outside
675 	 * of the chroot/workdir or we no longer have permissions */
676 	if(daemon->pidfile) {
677 		int fd;
678 		/* truncate pidfile */
679 		fd = open(daemon->pidfile, O_WRONLY | O_TRUNC, 0644);
680 		if(fd != -1)
681 			close(fd);
682 		/* delete pidfile */
683 		unlink(daemon->pidfile);
684 	}
685 	daemon_delete(daemon);
686 }
687 
688 /** getopt global, in case header files fail to declare it. */
689 extern int optind;
690 /** getopt global, in case header files fail to declare it. */
691 extern char* optarg;
692 
693 /**
694  * main program. Set options given commandline arguments.
695  * @param argc: number of commandline arguments.
696  * @param argv: array of commandline arguments.
697  * @return: exit status of the program.
698  */
699 int
700 main(int argc, char* argv[])
701 {
702 	int c;
703 	const char* cfgfile = CONFIGFILE;
704 	const char* winopt = NULL;
705 	int cmdline_verbose = 0;
706 	int debug_mode = 0;
707 #ifdef UB_ON_WINDOWS
708 	int cmdline_cfg = 0;
709 #endif
710 
711 #ifdef HAVE_SBRK
712 	/* take debug snapshot of heap */
713 	unbound_start_brk = sbrk(0);
714 #endif
715 
716 	log_init(NULL, 0, NULL);
717 	/* parse the options */
718 	while( (c=getopt(argc, argv, "c:dhvw:")) != -1) {
719 		switch(c) {
720 		case 'c':
721 			cfgfile = optarg;
722 #ifdef UB_ON_WINDOWS
723 			cmdline_cfg = 1;
724 #endif
725 			break;
726 		case 'v':
727 			cmdline_verbose ++;
728 			verbosity++;
729 			break;
730 		case 'd':
731 			debug_mode = 1;
732 			break;
733 		case 'w':
734 			winopt = optarg;
735 			break;
736 		case '?':
737 		case 'h':
738 		default:
739 			usage();
740 			return 1;
741 		}
742 	}
743 	argc -= optind;
744 	argv += optind;
745 
746 	if(winopt) {
747 #ifdef UB_ON_WINDOWS
748 		wsvc_command_option(winopt, cfgfile, cmdline_verbose,
749 			cmdline_cfg);
750 #else
751 		fatal_exit("option not supported");
752 #endif
753 	}
754 
755 	if(argc != 0) {
756 		usage();
757 		return 1;
758 	}
759 
760 	run_daemon(cfgfile, cmdline_verbose, debug_mode);
761 	log_init(NULL, 0, NULL); /* close logfile */
762 	return 0;
763 }
764