xref: /freebsd/contrib/unbound/daemon/unbound.c (revision 1b9cfd6a625dc82611846cb9a53c1886f7af3758)
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
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE 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/fptr_wlist.h"
57 #include "util/data/msgreply.h"
58 #include "util/module.h"
59 #include "util/net_help.h"
60 #include "util/ub_event.h"
61 #include <signal.h>
62 #include <fcntl.h>
63 #include <openssl/crypto.h>
64 #ifdef HAVE_PWD_H
65 #include <pwd.h>
66 #endif
67 #ifdef HAVE_GRP_H
68 #include <grp.h>
69 #endif
70 #include <openssl/ssl.h>
71 
72 #ifndef S_SPLINT_S
73 /* splint chokes on this system header file */
74 #ifdef HAVE_SYS_RESOURCE_H
75 #include <sys/resource.h>
76 #endif
77 #endif /* S_SPLINT_S */
78 #ifdef HAVE_LOGIN_CAP_H
79 #include <login_cap.h>
80 #endif
81 
82 #ifdef UB_ON_WINDOWS
83 #  include "winrc/win_svc.h"
84 #endif
85 
86 #ifdef HAVE_NSS
87 /* nss3 */
88 #  include "nss.h"
89 #endif
90 
91 #ifdef HAVE_TARGETCONDITIONALS_H
92 #include <TargetConditionals.h>
93 #endif
94 
95 #if (defined(TARGET_OS_TV) && TARGET_OS_TV) || (defined(TARGET_OS_WATCH) && TARGET_OS_WATCH)
96 #undef HAVE_FORK
97 #endif
98 
99 /** print build options. */
100 static void
101 print_build_options(void)
102 {
103 	const char** m;
104 	const char *evnm="event", *evsys="", *evmethod="";
105 	time_t t;
106 	struct timeval now;
107 	struct ub_event_base* base;
108 	printf("Version %s\n\n", PACKAGE_VERSION);
109 	printf("Configure line: %s\n", CONFCMDLINE);
110 	base = ub_default_event_base(0,&t,&now);
111 	ub_get_event_sys(base, &evnm, &evsys, &evmethod);
112 	printf("Linked libs: %s %s (it uses %s), %s\n",
113 		evnm, evsys, evmethod,
114 #ifdef HAVE_SSL
115 #  ifdef SSLEAY_VERSION
116 		SSLeay_version(SSLEAY_VERSION)
117 #  else
118 		OpenSSL_version(OPENSSL_VERSION)
119 #  endif
120 #elif defined(HAVE_NSS)
121 		NSS_GetVersion()
122 #elif defined(HAVE_NETTLE)
123 		"nettle"
124 #endif
125 		);
126 	printf("Linked modules:");
127 	for(m = module_list_avail(); *m; m++)
128 		printf(" %s", *m);
129 	printf("\n");
130 #ifdef USE_DNSCRYPT
131 	printf("DNSCrypt feature available\n");
132 #endif
133 #ifdef USE_TCP_FASTOPEN
134 	printf("TCP Fastopen feature available\n");
135 #endif
136 	ub_event_base_free(base);
137 	printf("\nBSD licensed, see LICENSE in source package for details.\n");
138 	printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
139 }
140 
141 /** print usage. */
142 static void
143 usage(void)
144 {
145 	printf("usage:  unbound [options]\n");
146 	printf("	start unbound daemon DNS resolver.\n");
147 	printf("-h	this help.\n");
148 	printf("-c file	config file to read instead of %s\n", CONFIGFILE);
149 	printf("	file format is described in unbound.conf(5).\n");
150 	printf("-d	do not fork into the background.\n");
151 	printf("-p	do not create a pidfile.\n");
152 	printf("-v	verbose (more times to increase verbosity).\n");
153 	printf("-V	show version number and build options.\n");
154 #ifdef UB_ON_WINDOWS
155 	printf("-w opt	windows option: \n");
156 	printf("   	install, remove - manage the services entry\n");
157 	printf("   	service - used to start from services control panel\n");
158 #endif
159 	printf("\nVersion %s\n", PACKAGE_VERSION);
160 	printf("BSD licensed, see LICENSE in source package for details.\n");
161 	printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
162 }
163 
164 #ifndef unbound_testbound
165 int replay_var_compare(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
166 {
167         log_assert(0);
168         return 0;
169 }
170 #endif
171 
172 /** check file descriptor count */
173 static void
174 checkrlimits(struct config_file* cfg)
175 {
176 #ifndef S_SPLINT_S
177 #ifdef HAVE_GETRLIMIT
178 	/* list has number of ports to listen to, ifs number addresses */
179 	int list = ((cfg->do_udp?1:0) + (cfg->do_tcp?1 +
180 			(int)cfg->incoming_num_tcp:0));
181 	size_t listen_ifs = (size_t)(cfg->num_ifs==0?
182 		((cfg->do_ip4 && !cfg->if_automatic?1:0) +
183 		 (cfg->do_ip6?1:0)):cfg->num_ifs);
184 	size_t listen_num = list*listen_ifs;
185 	size_t outudpnum = (size_t)cfg->outgoing_num_ports;
186 	size_t outtcpnum = cfg->outgoing_num_tcp;
187 	size_t misc = 4; /* logfile, pidfile, stdout... */
188 	size_t perthread_noudp = listen_num + outtcpnum +
189 		2/*cmdpipe*/ + 2/*libevent*/ + misc;
190 	size_t perthread = perthread_noudp + outudpnum;
191 
192 #if !defined(HAVE_PTHREAD) && !defined(HAVE_SOLARIS_THREADS)
193 	int numthread = 1; /* it forks */
194 #else
195 	int numthread = (cfg->num_threads?cfg->num_threads:1);
196 #endif
197 	size_t total = numthread * perthread + misc;
198 	size_t avail;
199 	struct rlimit rlim;
200 	size_t memsize_expect = cfg->msg_cache_size + cfg->rrset_cache_size
201 		+ (cfg->do_tcp?cfg->stream_wait_size:0)
202 		+ (cfg->ip_ratelimit?cfg->ip_ratelimit_size:0)
203 		+ (cfg->ratelimit?cfg->ratelimit_size:0)
204 		+ (cfg->dnscrypt?cfg->dnscrypt_shared_secret_cache_size + cfg->dnscrypt_nonce_cache_size:0)
205 		+ cfg->infra_cache_numhosts * (sizeof(struct infra_key)+sizeof(struct infra_data));
206 	if(strstr(cfg->module_conf, "validator") && (cfg->trust_anchor_file_list || cfg->trust_anchor_list || cfg->auto_trust_anchor_file_list || cfg->trusted_keys_file_list)) {
207 		memsize_expect += cfg->key_cache_size + cfg->neg_cache_size;
208 	}
209 #ifdef HAVE_NGHTTP2_NGHTTP2_H
210 	if(cfg_has_https(cfg)) {
211 		memsize_expect += cfg->http_query_buffer_size + cfg->http_response_buffer_size;
212 	}
213 #endif
214 
215 #ifdef RLIMIT_AS
216 	if(getrlimit(RLIMIT_AS, &rlim) == 0) {
217 		if(rlim.rlim_cur != (rlim_t)RLIM_INFINITY &&
218 			rlim.rlim_cur < (rlim_t)memsize_expect) {
219 			log_warn("the ulimit(max memory size) is smaller than the expected memory usage (added size of caches). %u < %u bytes", (unsigned)rlim.rlim_cur, (unsigned)memsize_expect);
220 		}
221 	}
222 #endif
223 	if(getrlimit(RLIMIT_DATA, &rlim) == 0) {
224 		if(rlim.rlim_cur != (rlim_t)RLIM_INFINITY &&
225 			rlim.rlim_cur < (rlim_t)memsize_expect) {
226 			log_warn("the ulimit(data seg size) is smaller than the expected memory usage (added size of caches). %u < %u bytes", (unsigned)rlim.rlim_cur, (unsigned)memsize_expect);
227 		}
228 	}
229 
230 	if(total > 1024 &&
231 		strncmp(ub_event_get_version(), "mini-event", 10) == 0) {
232 		log_warn("too many file descriptors requested. The builtin"
233 			"mini-event cannot handle more than 1024. Config "
234 			"for less fds or compile with libevent");
235 		if(numthread*perthread_noudp+15 > 1024)
236 			fatal_exit("too much tcp. not enough fds.");
237 		cfg->outgoing_num_ports = (int)((1024
238 			- numthread*perthread_noudp
239 			- 10 /* safety margin */) /numthread);
240 		log_warn("continuing with less udp ports: %u",
241 			cfg->outgoing_num_ports);
242 		total = 1024;
243 	}
244 	if(perthread > 64 &&
245 		strncmp(ub_event_get_version(), "winsock-event", 13) == 0) {
246 		log_err("too many file descriptors requested. The winsock"
247 			" event handler cannot handle more than 64 per "
248 			" thread. Config for less fds");
249 		if(perthread_noudp+2 > 64)
250 			fatal_exit("too much tcp. not enough fds.");
251 		cfg->outgoing_num_ports = (int)((64
252 			- perthread_noudp
253 			- 2/* safety margin */));
254 		log_warn("continuing with less udp ports: %u",
255 			cfg->outgoing_num_ports);
256 		total = numthread*(perthread_noudp+
257 			(size_t)cfg->outgoing_num_ports)+misc;
258 	}
259 	if(getrlimit(RLIMIT_NOFILE, &rlim) < 0) {
260 		log_warn("getrlimit: %s", strerror(errno));
261 		return;
262 	}
263 	if(rlim.rlim_cur == (rlim_t)RLIM_INFINITY)
264 		return;
265 	if((size_t)rlim.rlim_cur < total) {
266 		avail = (size_t)rlim.rlim_cur;
267 		rlim.rlim_cur = (rlim_t)(total + 10);
268 		rlim.rlim_max = (rlim_t)(total + 10);
269 #ifdef HAVE_SETRLIMIT
270 		if(setrlimit(RLIMIT_NOFILE, &rlim) < 0) {
271 			log_warn("setrlimit: %s", strerror(errno));
272 #endif
273 			log_warn("cannot increase max open fds from %u to %u",
274 				(unsigned)avail, (unsigned)total+10);
275 			/* check that calculation below does not underflow,
276 			 * with 15 as margin */
277 			if(numthread*perthread_noudp+15 > avail)
278 				fatal_exit("too much tcp. not enough fds.");
279 			cfg->outgoing_num_ports = (int)((avail
280 				- numthread*perthread_noudp
281 				- 10 /* safety margin */) /numthread);
282 			log_warn("continuing with less udp ports: %u",
283 				cfg->outgoing_num_ports);
284 			log_warn("increase ulimit or decrease threads, "
285 				"ports in config to remove this warning");
286 			return;
287 #ifdef HAVE_SETRLIMIT
288 		}
289 #endif
290 		verbose(VERB_ALGO, "increased limit(open files) from %u to %u",
291 			(unsigned)avail, (unsigned)total+10);
292 	}
293 #else
294 	(void)cfg;
295 #endif /* HAVE_GETRLIMIT */
296 #endif /* S_SPLINT_S */
297 }
298 
299 /** set verbosity, check rlimits, cache settings */
300 static void
301 apply_settings(struct daemon* daemon, struct config_file* cfg,
302 	int cmdline_verbose, int debug_mode)
303 {
304 	/* apply if they have changed */
305 	verbosity = cmdline_verbose + cfg->verbosity;
306 	if (debug_mode > 1) {
307 		cfg->use_syslog = 0;
308 		free(cfg->logfile);
309 		cfg->logfile = NULL;
310 	}
311 	daemon_apply_cfg(daemon, cfg);
312 	checkrlimits(cfg);
313 
314 	if (cfg->use_systemd && cfg->do_daemonize) {
315 		log_warn("use-systemd and do-daemonize should not be enabled at the same time");
316 	}
317 
318 	log_ident_set_or_default(cfg->log_identity);
319 }
320 
321 #ifdef HAVE_KILL
322 /** Read existing pid from pidfile.
323  * @param file: file name of pid file.
324  * @return: the pid from the file or -1 if none.
325  */
326 static pid_t
327 readpid (const char* file)
328 {
329 	int fd;
330 	pid_t pid;
331 	char pidbuf[32];
332 	char* t;
333 	ssize_t l;
334 
335 	if ((fd = open(file, O_RDONLY)) == -1) {
336 		if(errno != ENOENT)
337 			log_err("Could not read pidfile %s: %s",
338 				file, strerror(errno));
339 		return -1;
340 	}
341 
342 	if (((l = read(fd, pidbuf, sizeof(pidbuf)))) == -1) {
343 		if(errno != ENOENT)
344 			log_err("Could not read pidfile %s: %s",
345 				file, strerror(errno));
346 		close(fd);
347 		return -1;
348 	}
349 
350 	close(fd);
351 
352 	/* Empty pidfile means no pidfile... */
353 	if (l == 0) {
354 		return -1;
355 	}
356 
357 	pidbuf[sizeof(pidbuf)-1] = 0;
358 	pid = (pid_t)strtol(pidbuf, &t, 10);
359 
360 	if (*t && *t != '\n') {
361 		return -1;
362 	}
363 	return pid;
364 }
365 
366 /** write pid to file.
367  * @param pidfile: file name of pid file.
368  * @param pid: pid to write to file.
369  */
370 static void
371 writepid (const char* pidfile, pid_t pid)
372 {
373 	int fd;
374 	char pidbuf[32];
375 	size_t count = 0;
376 	snprintf(pidbuf, sizeof(pidbuf), "%lu\n", (unsigned long)pid);
377 
378 	if((fd = open(pidfile, O_WRONLY | O_CREAT | O_TRUNC
379 #ifdef O_NOFOLLOW
380 		| O_NOFOLLOW
381 #endif
382 		, 0644)) == -1) {
383 		log_err("cannot open pidfile %s: %s",
384 			pidfile, strerror(errno));
385 		return;
386 	}
387 	while(count < strlen(pidbuf)) {
388 		ssize_t r = write(fd, pidbuf+count, strlen(pidbuf)-count);
389 		if(r == -1) {
390 			if(errno == EAGAIN || errno == EINTR)
391 				continue;
392 			log_err("cannot write to pidfile %s: %s",
393 				pidfile, strerror(errno));
394 			close(fd);
395 			return;
396 		} else if(r == 0) {
397 			log_err("cannot write any bytes to pidfile %s: "
398 				"write returns 0 bytes written", pidfile);
399 			close(fd);
400 			return;
401 		}
402 		count += r;
403 	}
404 	close(fd);
405 }
406 
407 /**
408  * check old pid file.
409  * @param pidfile: the file name of the pid file.
410  * @param inchroot: if pidfile is inchroot and we can thus expect to
411  *	be able to delete it.
412  */
413 static void
414 checkoldpid(char* pidfile, int inchroot)
415 {
416 	pid_t old;
417 	if((old = readpid(pidfile)) != -1) {
418 		/* see if it is still alive */
419 		if(kill(old, 0) == 0 || errno == EPERM)
420 			log_warn("unbound is already running as pid %u.",
421 				(unsigned)old);
422 		else	if(inchroot)
423 			log_warn("did not exit gracefully last time (%u)",
424 				(unsigned)old);
425 	}
426 }
427 #endif /* HAVE_KILL */
428 
429 /** detach from command line */
430 static void
431 detach(void)
432 {
433 #if defined(HAVE_DAEMON) && !defined(DEPRECATED_DAEMON)
434 	/* use POSIX daemon(3) function */
435 	if(daemon(1, 0) != 0)
436 		fatal_exit("daemon failed: %s", strerror(errno));
437 #else /* no HAVE_DAEMON */
438 #ifdef HAVE_FORK
439 	int fd;
440 	/* Take off... */
441 	switch (fork()) {
442 		case 0:
443 			break;
444 		case -1:
445 			fatal_exit("fork failed: %s", strerror(errno));
446 		default:
447 			/* exit interactive session */
448 			exit(0);
449 	}
450 	/* detach */
451 #ifdef HAVE_SETSID
452 	if(setsid() == -1)
453 		fatal_exit("setsid() failed: %s", strerror(errno));
454 #endif
455 	if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
456 		(void)dup2(fd, STDIN_FILENO);
457 		(void)dup2(fd, STDOUT_FILENO);
458 		(void)dup2(fd, STDERR_FILENO);
459 		if (fd > 2)
460 			(void)close(fd);
461 	}
462 #endif /* HAVE_FORK */
463 #endif /* HAVE_DAEMON */
464 }
465 
466 /** daemonize, drop user privileges and chroot if needed */
467 static void
468 perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
469 	const char** cfgfile, int need_pidfile)
470 {
471 #ifdef HAVE_KILL
472 	int pidinchroot;
473 #endif
474 #ifdef HAVE_GETPWNAM
475 	struct passwd *pwd = NULL;
476 #endif
477 
478 	if(!daemon_privileged(daemon))
479 		fatal_exit("could not do privileged setup");
480 #ifdef HAVE_GETPWNAM
481 	if(cfg->username && cfg->username[0]) {
482 		if((pwd = getpwnam(cfg->username)) == NULL)
483 			fatal_exit("user '%s' does not exist.", cfg->username);
484 		/* endpwent below, in case we need pwd for setusercontext */
485 	}
486 #endif
487 #ifdef UB_ON_WINDOWS
488 	w_config_adjust_directory(cfg);
489 #endif
490 
491 	/* read ssl keys while superuser and outside chroot */
492 #ifdef HAVE_SSL
493 	if(!(daemon->rc = daemon_remote_create(cfg)))
494 		fatal_exit("could not set up remote-control");
495 	if(cfg->ssl_service_key && cfg->ssl_service_key[0]) {
496 		if(!(daemon->listen_sslctx = listen_sslctx_create(
497 			cfg->ssl_service_key, cfg->ssl_service_pem, NULL)))
498 			fatal_exit("could not set up listen SSL_CTX");
499 		if(cfg->tls_ciphers && cfg->tls_ciphers[0]) {
500 			if (!SSL_CTX_set_cipher_list(daemon->listen_sslctx, cfg->tls_ciphers)) {
501 				fatal_exit("failed to set tls-cipher %s", cfg->tls_ciphers);
502 			}
503 		}
504 #ifdef HAVE_SSL_CTX_SET_CIPHERSUITES
505 		if(cfg->tls_ciphersuites && cfg->tls_ciphersuites[0]) {
506 			if (!SSL_CTX_set_ciphersuites(daemon->listen_sslctx, cfg->tls_ciphersuites)) {
507 				fatal_exit("failed to set tls-ciphersuites %s", cfg->tls_ciphersuites);
508 			}
509 		}
510 #endif
511 		if(cfg->tls_session_ticket_keys.first &&
512 			cfg->tls_session_ticket_keys.first->str[0] != 0) {
513 			if(!listen_sslctx_setup_ticket_keys(daemon->listen_sslctx, cfg->tls_session_ticket_keys.first)) {
514 				fatal_exit("could not set session ticket SSL_CTX");
515 			}
516 		}
517 	}
518 	if(!(daemon->connect_sslctx = connect_sslctx_create(NULL, NULL,
519 		cfg->tls_cert_bundle, cfg->tls_win_cert)))
520 		fatal_exit("could not set up connect SSL_CTX");
521 #endif
522 
523 	/* init syslog (as root) if needed, before daemonize, otherwise
524 	 * a fork error could not be printed since daemonize closed stderr.*/
525 	if(cfg->use_syslog) {
526 		log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
527 	}
528 	/* if using a logfile, we cannot open it because the logfile would
529 	 * be created with the wrong permissions, we cannot chown it because
530 	 * we cannot chown system logfiles, so we do not open at all.
531 	 * So, using a logfile, the user does not see errors unless -d is
532 	 * given to unbound on the commandline. */
533 
534 #ifdef HAVE_KILL
535 	/* true if pidfile is inside chrootdir, or nochroot */
536 	pidinchroot = need_pidfile && (!(cfg->chrootdir && cfg->chrootdir[0]) ||
537 				(cfg->chrootdir && cfg->chrootdir[0] &&
538 				strncmp(cfg->pidfile, cfg->chrootdir,
539 				strlen(cfg->chrootdir))==0));
540 
541 	/* check old pid file before forking */
542 	if(cfg->pidfile && cfg->pidfile[0] && need_pidfile) {
543 		/* calculate position of pidfile */
544 		if(cfg->pidfile[0] == '/')
545 			daemon->pidfile = strdup(cfg->pidfile);
546 		else	daemon->pidfile = fname_after_chroot(cfg->pidfile,
547 				cfg, 1);
548 		if(!daemon->pidfile)
549 			fatal_exit("pidfile alloc: out of memory");
550 		/* Check old pid if there is no username configured.
551 		 * With a username, the assumption is that the privilege
552 		 * drop makes a pidfile not removed when the server stopped
553 		 * last time. The server does not chown the pidfile for it,
554 		 * because that creates privilege escape problems, with the
555 		 * pidfile writable by unprivileged users, but used by
556 		 * privileged users. */
557 		if(!(cfg->username && cfg->username[0]))
558 			checkoldpid(daemon->pidfile, pidinchroot);
559 	}
560 #endif
561 
562 	/* daemonize because pid is needed by the writepid func */
563 	if(!debug_mode && cfg->do_daemonize) {
564 		detach();
565 	}
566 
567 	/* write new pidfile (while still root, so can be outside chroot) */
568 #ifdef HAVE_KILL
569 	if(cfg->pidfile && cfg->pidfile[0] && need_pidfile) {
570 		writepid(daemon->pidfile, getpid());
571 	}
572 #else
573 	(void)daemon;
574 	(void)need_pidfile;
575 #endif /* HAVE_KILL */
576 
577 	/* Set user context */
578 #ifdef HAVE_GETPWNAM
579 	if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1) {
580 #ifdef HAVE_SETUSERCONTEXT
581 		/* setusercontext does initgroups, setuid, setgid, and
582 		 * also resource limits from login config, but we
583 		 * still call setresuid, setresgid to be sure to set all uid*/
584 		if(setusercontext(NULL, pwd, cfg_uid, (unsigned)
585 			LOGIN_SETALL & ~LOGIN_SETUSER & ~LOGIN_SETGROUP) != 0)
586 			log_warn("unable to setusercontext %s: %s",
587 				cfg->username, strerror(errno));
588 #else
589 		(void)pwd;
590 #endif /* HAVE_SETUSERCONTEXT */
591 	}
592 #endif /* HAVE_GETPWNAM */
593 
594 	/* box into the chroot */
595 #ifdef HAVE_CHROOT
596 	if(cfg->chrootdir && cfg->chrootdir[0]) {
597 		if(chdir(cfg->chrootdir)) {
598 			fatal_exit("unable to chdir to chroot %s: %s",
599 				cfg->chrootdir, strerror(errno));
600 		}
601 		verbose(VERB_QUERY, "chdir to %s", cfg->chrootdir);
602 		if(chroot(cfg->chrootdir))
603 			fatal_exit("unable to chroot to %s: %s",
604 				cfg->chrootdir, strerror(errno));
605 		if(chdir("/"))
606 			fatal_exit("unable to chdir to / in chroot %s: %s",
607 				cfg->chrootdir, strerror(errno));
608 		verbose(VERB_QUERY, "chroot to %s", cfg->chrootdir);
609 		if(strncmp(*cfgfile, cfg->chrootdir,
610 			strlen(cfg->chrootdir)) == 0)
611 			(*cfgfile) += strlen(cfg->chrootdir);
612 
613 		/* adjust stored pidfile for chroot */
614 		if(daemon->pidfile && daemon->pidfile[0] &&
615 			strncmp(daemon->pidfile, cfg->chrootdir,
616 			strlen(cfg->chrootdir))==0) {
617 			char* old = daemon->pidfile;
618 			daemon->pidfile = strdup(old+strlen(cfg->chrootdir));
619 			free(old);
620 			if(!daemon->pidfile)
621 				log_err("out of memory in pidfile adjust");
622 		}
623 		daemon->chroot = strdup(cfg->chrootdir);
624 		if(!daemon->chroot)
625 			log_err("out of memory in daemon chroot dir storage");
626 	}
627 #else
628 	(void)cfgfile;
629 #endif
630 	/* change to working directory inside chroot */
631 	if(cfg->directory && cfg->directory[0]) {
632 		char* dir = cfg->directory;
633 		if(cfg->chrootdir && cfg->chrootdir[0] &&
634 			strncmp(dir, cfg->chrootdir,
635 			strlen(cfg->chrootdir)) == 0)
636 			dir += strlen(cfg->chrootdir);
637 		if(dir[0]) {
638 			if(chdir(dir)) {
639 				fatal_exit("Could not chdir to %s: %s",
640 					dir, strerror(errno));
641 			}
642 			verbose(VERB_QUERY, "chdir to %s", dir);
643 		}
644 	}
645 
646 	/* drop permissions after chroot, getpwnam, pidfile, syslog done*/
647 #ifdef HAVE_GETPWNAM
648 	if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1) {
649 #  ifdef HAVE_INITGROUPS
650 		if(initgroups(cfg->username, cfg_gid) != 0)
651 			log_warn("unable to initgroups %s: %s",
652 				cfg->username, strerror(errno));
653 #  endif /* HAVE_INITGROUPS */
654 #  ifdef HAVE_ENDPWENT
655 		endpwent();
656 #  endif
657 
658 #ifdef HAVE_SETRESGID
659 		if(setresgid(cfg_gid,cfg_gid,cfg_gid) != 0)
660 #elif defined(HAVE_SETREGID) && !defined(DARWIN_BROKEN_SETREUID)
661 		if(setregid(cfg_gid,cfg_gid) != 0)
662 #else /* use setgid */
663 		if(setgid(cfg_gid) != 0)
664 #endif /* HAVE_SETRESGID */
665 			fatal_exit("unable to set group id of %s: %s",
666 				cfg->username, strerror(errno));
667 #ifdef HAVE_SETRESUID
668 		if(setresuid(cfg_uid,cfg_uid,cfg_uid) != 0)
669 #elif defined(HAVE_SETREUID) && !defined(DARWIN_BROKEN_SETREUID)
670 		if(setreuid(cfg_uid,cfg_uid) != 0)
671 #else /* use setuid */
672 		if(setuid(cfg_uid) != 0)
673 #endif /* HAVE_SETRESUID */
674 			fatal_exit("unable to set user id of %s: %s",
675 				cfg->username, strerror(errno));
676 		verbose(VERB_QUERY, "drop user privileges, run as %s",
677 			cfg->username);
678 	}
679 #endif /* HAVE_GETPWNAM */
680 	/* file logging inited after chroot,chdir,setuid is done so that
681 	 * it would succeed on SIGHUP as well */
682 	if(!cfg->use_syslog)
683 		log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
684 }
685 
686 /**
687  * Run the daemon.
688  * @param cfgfile: the config file name.
689  * @param cmdline_verbose: verbosity resulting from commandline -v.
690  *    These increase verbosity as specified in the config file.
691  * @param debug_mode: if set, do not daemonize.
692  * @param need_pidfile: if false, no pidfile is checked or created.
693  */
694 static void
695 run_daemon(const char* cfgfile, int cmdline_verbose, int debug_mode, int need_pidfile)
696 {
697 	struct config_file* cfg = NULL;
698 	struct daemon* daemon = NULL;
699 	int done_setup = 0;
700 
701 	if(!(daemon = daemon_init()))
702 		fatal_exit("alloc failure");
703 	while(!daemon->need_to_exit) {
704 		if(done_setup)
705 			verbose(VERB_OPS, "Restart of %s.", PACKAGE_STRING);
706 		else	verbose(VERB_OPS, "Start of %s.", PACKAGE_STRING);
707 
708 		/* config stuff */
709 		if(!(cfg = config_create()))
710 			fatal_exit("Could not alloc config defaults");
711 		if(!config_read(cfg, cfgfile, daemon->chroot)) {
712 			if(errno != ENOENT)
713 				fatal_exit("Could not read config file: %s."
714 					" Maybe try unbound -dd, it stays on "
715 					"the commandline to see more errors, "
716 					"or unbound-checkconf", cfgfile);
717 			log_warn("Continuing with default config settings");
718 		}
719 		apply_settings(daemon, cfg, cmdline_verbose, debug_mode);
720 		if(!done_setup)
721 			config_lookup_uid(cfg);
722 
723 		/* prepare */
724 		if(!daemon_open_shared_ports(daemon))
725 			fatal_exit("could not open ports");
726 		if(!done_setup) {
727 			perform_setup(daemon, cfg, debug_mode, &cfgfile, need_pidfile);
728 			done_setup = 1;
729 		} else {
730 			/* reopen log after HUP to facilitate log rotation */
731 			if(!cfg->use_syslog)
732 				log_init(cfg->logfile, 0, cfg->chrootdir);
733 		}
734 		/* work */
735 		daemon_fork(daemon);
736 
737 		/* clean up for restart */
738 		verbose(VERB_ALGO, "cleanup.");
739 		daemon_cleanup(daemon);
740 		config_delete(cfg);
741 	}
742 	verbose(VERB_ALGO, "Exit cleanup.");
743 	/* this unlink may not work if the pidfile is located outside
744 	 * of the chroot/workdir or we no longer have permissions */
745 	if(daemon->pidfile) {
746 		int fd;
747 		/* truncate pidfile */
748 		fd = open(daemon->pidfile, O_WRONLY | O_TRUNC
749 #ifdef O_NOFOLLOW
750 			| O_NOFOLLOW
751 #endif
752 			, 0644);
753 		if(fd != -1)
754 			close(fd);
755 		/* delete pidfile */
756 		unlink(daemon->pidfile);
757 	}
758 	daemon_delete(daemon);
759 }
760 
761 /** getopt global, in case header files fail to declare it. */
762 extern int optind;
763 /** getopt global, in case header files fail to declare it. */
764 extern char* optarg;
765 
766 /**
767  * main program. Set options given commandline arguments.
768  * @param argc: number of commandline arguments.
769  * @param argv: array of commandline arguments.
770  * @return: exit status of the program.
771  */
772 int
773 main(int argc, char* argv[])
774 {
775 	int c;
776 	const char* cfgfile = CONFIGFILE;
777 	const char* winopt = NULL;
778 	const char* log_ident_default;
779 	int cmdline_verbose = 0;
780 	int debug_mode = 0;
781 	int need_pidfile = 1;
782 
783 #ifdef UB_ON_WINDOWS
784 	int cmdline_cfg = 0;
785 #endif
786 
787 	checklock_start();
788 	log_init(NULL, 0, NULL);
789 	log_ident_default = strrchr(argv[0],'/')?strrchr(argv[0],'/')+1:argv[0];
790 	log_ident_set_default(log_ident_default);
791 	log_ident_set(log_ident_default);
792 	/* parse the options */
793 	while( (c=getopt(argc, argv, "c:dhpvw:V")) != -1) {
794 		switch(c) {
795 		case 'c':
796 			cfgfile = optarg;
797 #ifdef UB_ON_WINDOWS
798 			cmdline_cfg = 1;
799 #endif
800 			break;
801 		case 'v':
802 			cmdline_verbose++;
803 			verbosity++;
804 			break;
805 		case 'p':
806 			need_pidfile = 0;
807 			break;
808 		case 'd':
809 			debug_mode++;
810 			break;
811 		case 'w':
812 			winopt = optarg;
813 			break;
814 		case 'V':
815 			print_build_options();
816 			return 0;
817 		case '?':
818 		case 'h':
819 		default:
820 			usage();
821 			return 1;
822 		}
823 	}
824 	argc -= optind;
825 	/* argv += optind; not using further arguments */
826 
827 	if(winopt) {
828 #ifdef UB_ON_WINDOWS
829 		wsvc_command_option(winopt, cfgfile, cmdline_verbose,
830 			cmdline_cfg);
831 #else
832 		fatal_exit("option not supported");
833 #endif
834 	}
835 
836 	if(argc != 0) {
837 		usage();
838 		return 1;
839 	}
840 
841 	run_daemon(cfgfile, cmdline_verbose, debug_mode, need_pidfile);
842 	log_init(NULL, 0, NULL); /* close logfile */
843 #ifndef unbound_testbound
844 	if(log_get_lock()) {
845 		lock_basic_destroy((lock_basic_type*)log_get_lock());
846 	}
847 #endif
848 	return 0;
849 }
850