unbound.c revision 356345
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/** print build options. */
92static void
93print_build_options(void)
94{
95	const char** m;
96	const char *evnm="event", *evsys="", *evmethod="";
97	time_t t;
98	struct timeval now;
99	struct ub_event_base* base;
100	printf("Version %s\n\n", PACKAGE_VERSION);
101	printf("Configure line: %s\n", CONFCMDLINE);
102	base = ub_default_event_base(0,&t,&now);
103	ub_get_event_sys(base, &evnm, &evsys, &evmethod);
104	printf("Linked libs: %s %s (it uses %s), %s\n",
105		evnm, evsys, evmethod,
106#ifdef HAVE_SSL
107#  ifdef SSLEAY_VERSION
108		SSLeay_version(SSLEAY_VERSION)
109#  else
110		OpenSSL_version(OPENSSL_VERSION)
111#  endif
112#elif defined(HAVE_NSS)
113		NSS_GetVersion()
114#elif defined(HAVE_NETTLE)
115		"nettle"
116#endif
117		);
118	printf("Linked modules:");
119	for(m = module_list_avail(); *m; m++)
120		printf(" %s", *m);
121	printf("\n");
122#ifdef USE_DNSCRYPT
123	printf("DNSCrypt feature available\n");
124#endif
125#ifdef USE_TCP_FASTOPEN
126	printf("TCP Fastopen feature available\n");
127#endif
128	ub_event_base_free(base);
129	printf("\nBSD licensed, see LICENSE in source package for details.\n");
130	printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
131}
132
133/** print usage. */
134static void
135usage(void)
136{
137	printf("usage:  unbound [options]\n");
138	printf("	start unbound daemon DNS resolver.\n");
139	printf("-h	this help.\n");
140	printf("-c file	config file to read instead of %s\n", CONFIGFILE);
141	printf("	file format is described in unbound.conf(5).\n");
142	printf("-d	do not fork into the background.\n");
143	printf("-p	do not create a pidfile.\n");
144	printf("-v	verbose (more times to increase verbosity).\n");
145	printf("-V	show version number and build options.\n");
146#ifdef UB_ON_WINDOWS
147	printf("-w opt	windows option: \n");
148	printf("   	install, remove - manage the services entry\n");
149	printf("   	service - used to start from services control panel\n");
150#endif
151	printf("\nVersion %s\n", PACKAGE_VERSION);
152	printf("BSD licensed, see LICENSE in source package for details.\n");
153	printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
154}
155
156#ifndef unbound_testbound
157int replay_var_compare(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
158{
159        log_assert(0);
160        return 0;
161}
162#endif
163
164/** check file descriptor count */
165static void
166checkrlimits(struct config_file* cfg)
167{
168#ifndef S_SPLINT_S
169#ifdef HAVE_GETRLIMIT
170	/* list has number of ports to listen to, ifs number addresses */
171	int list = ((cfg->do_udp?1:0) + (cfg->do_tcp?1 +
172			(int)cfg->incoming_num_tcp:0));
173	size_t listen_ifs = (size_t)(cfg->num_ifs==0?
174		((cfg->do_ip4 && !cfg->if_automatic?1:0) +
175		 (cfg->do_ip6?1:0)):cfg->num_ifs);
176	size_t listen_num = list*listen_ifs;
177	size_t outudpnum = (size_t)cfg->outgoing_num_ports;
178	size_t outtcpnum = cfg->outgoing_num_tcp;
179	size_t misc = 4; /* logfile, pidfile, stdout... */
180	size_t perthread_noudp = listen_num + outtcpnum +
181		2/*cmdpipe*/ + 2/*libevent*/ + misc;
182	size_t perthread = perthread_noudp + outudpnum;
183
184#if !defined(HAVE_PTHREAD) && !defined(HAVE_SOLARIS_THREADS)
185	int numthread = 1; /* it forks */
186#else
187	int numthread = (cfg->num_threads?cfg->num_threads:1);
188#endif
189	size_t total = numthread * perthread + misc;
190	size_t avail;
191	struct rlimit rlim;
192
193	if(total > 1024 &&
194		strncmp(ub_event_get_version(), "mini-event", 10) == 0) {
195		log_warn("too many file descriptors requested. The builtin"
196			"mini-event cannot handle more than 1024. Config "
197			"for less fds or compile with libevent");
198		if(numthread*perthread_noudp+15 > 1024)
199			fatal_exit("too much tcp. not enough fds.");
200		cfg->outgoing_num_ports = (int)((1024
201			- numthread*perthread_noudp
202			- 10 /* safety margin */) /numthread);
203		log_warn("continuing with less udp ports: %u",
204			cfg->outgoing_num_ports);
205		total = 1024;
206	}
207	if(perthread > 64 &&
208		strncmp(ub_event_get_version(), "winsock-event", 13) == 0) {
209		log_err("too many file descriptors requested. The winsock"
210			" event handler cannot handle more than 64 per "
211			" thread. Config for less fds");
212		if(perthread_noudp+2 > 64)
213			fatal_exit("too much tcp. not enough fds.");
214		cfg->outgoing_num_ports = (int)((64
215			- perthread_noudp
216			- 2/* safety margin */));
217		log_warn("continuing with less udp ports: %u",
218			cfg->outgoing_num_ports);
219		total = numthread*(perthread_noudp+
220			(size_t)cfg->outgoing_num_ports)+misc;
221	}
222	if(getrlimit(RLIMIT_NOFILE, &rlim) < 0) {
223		log_warn("getrlimit: %s", strerror(errno));
224		return;
225	}
226	if(rlim.rlim_cur == (rlim_t)RLIM_INFINITY)
227		return;
228	if((size_t)rlim.rlim_cur < total) {
229		avail = (size_t)rlim.rlim_cur;
230		rlim.rlim_cur = (rlim_t)(total + 10);
231		rlim.rlim_max = (rlim_t)(total + 10);
232#ifdef HAVE_SETRLIMIT
233		if(setrlimit(RLIMIT_NOFILE, &rlim) < 0) {
234			log_warn("setrlimit: %s", strerror(errno));
235#endif
236			log_warn("cannot increase max open fds from %u to %u",
237				(unsigned)avail, (unsigned)total+10);
238			/* check that calculation below does not underflow,
239			 * with 15 as margin */
240			if(numthread*perthread_noudp+15 > avail)
241				fatal_exit("too much tcp. not enough fds.");
242			cfg->outgoing_num_ports = (int)((avail
243				- numthread*perthread_noudp
244				- 10 /* safety margin */) /numthread);
245			log_warn("continuing with less udp ports: %u",
246				cfg->outgoing_num_ports);
247			log_warn("increase ulimit or decrease threads, "
248				"ports in config to remove this warning");
249			return;
250#ifdef HAVE_SETRLIMIT
251		}
252#endif
253		verbose(VERB_ALGO, "increased limit(open files) from %u to %u",
254			(unsigned)avail, (unsigned)total+10);
255	}
256#else
257	(void)cfg;
258#endif /* HAVE_GETRLIMIT */
259#endif /* S_SPLINT_S */
260}
261
262/** set default logfile identity based on value from argv[0] at startup **/
263static void
264log_ident_set_fromdefault(struct config_file* cfg,
265	const char *log_default_identity)
266{
267	if(cfg->log_identity == NULL || cfg->log_identity[0] == 0)
268		log_ident_set(log_default_identity);
269	else
270		log_ident_set(cfg->log_identity);
271}
272
273/** set verbosity, check rlimits, cache settings */
274static void
275apply_settings(struct daemon* daemon, struct config_file* cfg,
276	int cmdline_verbose, int debug_mode, const char* log_default_identity)
277{
278	/* apply if they have changed */
279	verbosity = cmdline_verbose + cfg->verbosity;
280	if (debug_mode > 1) {
281		cfg->use_syslog = 0;
282		free(cfg->logfile);
283		cfg->logfile = NULL;
284	}
285	daemon_apply_cfg(daemon, cfg);
286	checkrlimits(cfg);
287
288	if (cfg->use_systemd && cfg->do_daemonize) {
289		log_warn("use-systemd and do-daemonize should not be enabled at the same time");
290	}
291
292	log_ident_set_fromdefault(cfg, log_default_identity);
293}
294
295#ifdef HAVE_KILL
296/** Read existing pid from pidfile.
297 * @param file: file name of pid file.
298 * @return: the pid from the file or -1 if none.
299 */
300static pid_t
301readpid (const char* file)
302{
303	int fd;
304	pid_t pid;
305	char pidbuf[32];
306	char* t;
307	ssize_t l;
308
309	if ((fd = open(file, O_RDONLY)) == -1) {
310		if(errno != ENOENT)
311			log_err("Could not read pidfile %s: %s",
312				file, strerror(errno));
313		return -1;
314	}
315
316	if (((l = read(fd, pidbuf, sizeof(pidbuf)))) == -1) {
317		if(errno != ENOENT)
318			log_err("Could not read pidfile %s: %s",
319				file, strerror(errno));
320		close(fd);
321		return -1;
322	}
323
324	close(fd);
325
326	/* Empty pidfile means no pidfile... */
327	if (l == 0) {
328		return -1;
329	}
330
331	pidbuf[sizeof(pidbuf)-1] = 0;
332	pid = (pid_t)strtol(pidbuf, &t, 10);
333
334	if (*t && *t != '\n') {
335		return -1;
336	}
337	return pid;
338}
339
340/** write pid to file.
341 * @param pidfile: file name of pid file.
342 * @param pid: pid to write to file.
343 */
344static void
345writepid (const char* pidfile, pid_t pid)
346{
347	FILE* f;
348
349	if ((f = fopen(pidfile, "w")) ==  NULL ) {
350		log_err("cannot open pidfile %s: %s",
351			pidfile, strerror(errno));
352		return;
353	}
354	if(fprintf(f, "%lu\n", (unsigned long)pid) < 0) {
355		log_err("cannot write to pidfile %s: %s",
356			pidfile, strerror(errno));
357	}
358	fclose(f);
359}
360
361/**
362 * check old pid file.
363 * @param pidfile: the file name of the pid file.
364 * @param inchroot: if pidfile is inchroot and we can thus expect to
365 *	be able to delete it.
366 */
367static void
368checkoldpid(char* pidfile, int inchroot)
369{
370	pid_t old;
371	if((old = readpid(pidfile)) != -1) {
372		/* see if it is still alive */
373		if(kill(old, 0) == 0 || errno == EPERM)
374			log_warn("unbound is already running as pid %u.",
375				(unsigned)old);
376		else	if(inchroot)
377			log_warn("did not exit gracefully last time (%u)",
378				(unsigned)old);
379	}
380}
381#endif /* HAVE_KILL */
382
383/** detach from command line */
384static void
385detach(void)
386{
387#if defined(HAVE_DAEMON) && !defined(DEPRECATED_DAEMON)
388	/* use POSIX daemon(3) function */
389	if(daemon(1, 0) != 0)
390		fatal_exit("daemon failed: %s", strerror(errno));
391#else /* no HAVE_DAEMON */
392#ifdef HAVE_FORK
393	int fd;
394	/* Take off... */
395	switch (fork()) {
396		case 0:
397			break;
398		case -1:
399			fatal_exit("fork failed: %s", strerror(errno));
400		default:
401			/* exit interactive session */
402			exit(0);
403	}
404	/* detach */
405#ifdef HAVE_SETSID
406	if(setsid() == -1)
407		fatal_exit("setsid() failed: %s", strerror(errno));
408#endif
409	if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
410		(void)dup2(fd, STDIN_FILENO);
411		(void)dup2(fd, STDOUT_FILENO);
412		(void)dup2(fd, STDERR_FILENO);
413		if (fd > 2)
414			(void)close(fd);
415	}
416#endif /* HAVE_FORK */
417#endif /* HAVE_DAEMON */
418}
419
420/** daemonize, drop user privileges and chroot if needed */
421static void
422perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
423	const char** cfgfile, int need_pidfile)
424{
425#ifdef HAVE_KILL
426	int pidinchroot;
427#endif
428#ifdef HAVE_GETPWNAM
429	struct passwd *pwd = NULL;
430
431	if(cfg->username && cfg->username[0]) {
432		if((pwd = getpwnam(cfg->username)) == NULL)
433			fatal_exit("user '%s' does not exist.", cfg->username);
434		/* endpwent below, in case we need pwd for setusercontext */
435	}
436#endif
437#ifdef UB_ON_WINDOWS
438	w_config_adjust_directory(cfg);
439#endif
440
441	/* read ssl keys while superuser and outside chroot */
442#ifdef HAVE_SSL
443	if(!(daemon->rc = daemon_remote_create(cfg)))
444		fatal_exit("could not set up remote-control");
445	if(cfg->ssl_service_key && cfg->ssl_service_key[0]) {
446		if(!(daemon->listen_sslctx = listen_sslctx_create(
447			cfg->ssl_service_key, cfg->ssl_service_pem, NULL)))
448			fatal_exit("could not set up listen SSL_CTX");
449		if(cfg->tls_ciphers && cfg->tls_ciphers[0]) {
450			if (!SSL_CTX_set_cipher_list(daemon->listen_sslctx, cfg->tls_ciphers)) {
451				fatal_exit("failed to set tls-cipher %s", cfg->tls_ciphers);
452			}
453		}
454#ifdef HAVE_SSL_CTX_SET_CIPHERSUITES
455		if(cfg->tls_ciphersuites && cfg->tls_ciphersuites[0]) {
456			if (!SSL_CTX_set_ciphersuites(daemon->listen_sslctx, cfg->tls_ciphersuites)) {
457				fatal_exit("failed to set tls-ciphersuites %s", cfg->tls_ciphersuites);
458			}
459		}
460#endif
461		if(cfg->tls_session_ticket_keys.first &&
462			cfg->tls_session_ticket_keys.first->str[0] != 0) {
463			if(!listen_sslctx_setup_ticket_keys(daemon->listen_sslctx, cfg->tls_session_ticket_keys.first)) {
464				fatal_exit("could not set session ticket SSL_CTX");
465			}
466		}
467	}
468	if(!(daemon->connect_sslctx = connect_sslctx_create(NULL, NULL,
469		cfg->tls_cert_bundle, cfg->tls_win_cert)))
470		fatal_exit("could not set up connect SSL_CTX");
471#endif
472
473	/* init syslog (as root) if needed, before daemonize, otherwise
474	 * a fork error could not be printed since daemonize closed stderr.*/
475	if(cfg->use_syslog) {
476		log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
477	}
478	/* if using a logfile, we cannot open it because the logfile would
479	 * be created with the wrong permissions, we cannot chown it because
480	 * we cannot chown system logfiles, so we do not open at all.
481	 * So, using a logfile, the user does not see errors unless -d is
482	 * given to unbound on the commandline. */
483
484#ifdef HAVE_KILL
485	/* true if pidfile is inside chrootdir, or nochroot */
486	pidinchroot = need_pidfile && (!(cfg->chrootdir && cfg->chrootdir[0]) ||
487				(cfg->chrootdir && cfg->chrootdir[0] &&
488				strncmp(cfg->pidfile, cfg->chrootdir,
489				strlen(cfg->chrootdir))==0));
490
491	/* check old pid file before forking */
492	if(cfg->pidfile && cfg->pidfile[0] && need_pidfile) {
493		/* calculate position of pidfile */
494		if(cfg->pidfile[0] == '/')
495			daemon->pidfile = strdup(cfg->pidfile);
496		else	daemon->pidfile = fname_after_chroot(cfg->pidfile,
497				cfg, 1);
498		if(!daemon->pidfile)
499			fatal_exit("pidfile alloc: out of memory");
500		checkoldpid(daemon->pidfile, pidinchroot);
501	}
502#endif
503
504	/* daemonize because pid is needed by the writepid func */
505	if(!debug_mode && cfg->do_daemonize) {
506		detach();
507	}
508
509	/* write new pidfile (while still root, so can be outside chroot) */
510#ifdef HAVE_KILL
511	if(cfg->pidfile && cfg->pidfile[0] && need_pidfile) {
512		writepid(daemon->pidfile, getpid());
513		if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1 &&
514			pidinchroot) {
515#  ifdef HAVE_CHOWN
516			if(chown(daemon->pidfile, cfg_uid, cfg_gid) == -1) {
517				verbose(VERB_QUERY, "cannot chown %u.%u %s: %s",
518					(unsigned)cfg_uid, (unsigned)cfg_gid,
519					daemon->pidfile, strerror(errno));
520			}
521#  endif /* HAVE_CHOWN */
522		}
523	}
524#else
525	(void)daemon;
526	(void)need_pidfile;
527#endif /* HAVE_KILL */
528
529	/* Set user context */
530#ifdef HAVE_GETPWNAM
531	if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1) {
532#ifdef HAVE_SETUSERCONTEXT
533		/* setusercontext does initgroups, setuid, setgid, and
534		 * also resource limits from login config, but we
535		 * still call setresuid, setresgid to be sure to set all uid*/
536		if(setusercontext(NULL, pwd, cfg_uid, (unsigned)
537			LOGIN_SETALL & ~LOGIN_SETUSER & ~LOGIN_SETGROUP) != 0)
538			log_warn("unable to setusercontext %s: %s",
539				cfg->username, strerror(errno));
540#endif /* HAVE_SETUSERCONTEXT */
541	}
542#endif /* HAVE_GETPWNAM */
543
544	/* box into the chroot */
545#ifdef HAVE_CHROOT
546	if(cfg->chrootdir && cfg->chrootdir[0]) {
547		if(chdir(cfg->chrootdir)) {
548			fatal_exit("unable to chdir to chroot %s: %s",
549				cfg->chrootdir, strerror(errno));
550		}
551		verbose(VERB_QUERY, "chdir to %s", cfg->chrootdir);
552		if(chroot(cfg->chrootdir))
553			fatal_exit("unable to chroot to %s: %s",
554				cfg->chrootdir, strerror(errno));
555		if(chdir("/"))
556			fatal_exit("unable to chdir to / in chroot %s: %s",
557				cfg->chrootdir, strerror(errno));
558		verbose(VERB_QUERY, "chroot to %s", cfg->chrootdir);
559		if(strncmp(*cfgfile, cfg->chrootdir,
560			strlen(cfg->chrootdir)) == 0)
561			(*cfgfile) += strlen(cfg->chrootdir);
562
563		/* adjust stored pidfile for chroot */
564		if(daemon->pidfile && daemon->pidfile[0] &&
565			strncmp(daemon->pidfile, cfg->chrootdir,
566			strlen(cfg->chrootdir))==0) {
567			char* old = daemon->pidfile;
568			daemon->pidfile = strdup(old+strlen(cfg->chrootdir));
569			free(old);
570			if(!daemon->pidfile)
571				log_err("out of memory in pidfile adjust");
572		}
573		daemon->chroot = strdup(cfg->chrootdir);
574		if(!daemon->chroot)
575			log_err("out of memory in daemon chroot dir storage");
576	}
577#else
578	(void)cfgfile;
579#endif
580	/* change to working directory inside chroot */
581	if(cfg->directory && cfg->directory[0]) {
582		char* dir = cfg->directory;
583		if(cfg->chrootdir && cfg->chrootdir[0] &&
584			strncmp(dir, cfg->chrootdir,
585			strlen(cfg->chrootdir)) == 0)
586			dir += strlen(cfg->chrootdir);
587		if(dir[0]) {
588			if(chdir(dir)) {
589				fatal_exit("Could not chdir to %s: %s",
590					dir, strerror(errno));
591			}
592			verbose(VERB_QUERY, "chdir to %s", dir);
593		}
594	}
595
596	/* drop permissions after chroot, getpwnam, pidfile, syslog done*/
597#ifdef HAVE_GETPWNAM
598	if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1) {
599#  ifdef HAVE_INITGROUPS
600		if(initgroups(cfg->username, cfg_gid) != 0)
601			log_warn("unable to initgroups %s: %s",
602				cfg->username, strerror(errno));
603#  endif /* HAVE_INITGROUPS */
604#  ifdef HAVE_ENDPWENT
605		endpwent();
606#  endif
607
608#ifdef HAVE_SETRESGID
609		if(setresgid(cfg_gid,cfg_gid,cfg_gid) != 0)
610#elif defined(HAVE_SETREGID) && !defined(DARWIN_BROKEN_SETREUID)
611		if(setregid(cfg_gid,cfg_gid) != 0)
612#else /* use setgid */
613		if(setgid(cfg_gid) != 0)
614#endif /* HAVE_SETRESGID */
615			fatal_exit("unable to set group id of %s: %s",
616				cfg->username, strerror(errno));
617#ifdef HAVE_SETRESUID
618		if(setresuid(cfg_uid,cfg_uid,cfg_uid) != 0)
619#elif defined(HAVE_SETREUID) && !defined(DARWIN_BROKEN_SETREUID)
620		if(setreuid(cfg_uid,cfg_uid) != 0)
621#else /* use setuid */
622		if(setuid(cfg_uid) != 0)
623#endif /* HAVE_SETRESUID */
624			fatal_exit("unable to set user id of %s: %s",
625				cfg->username, strerror(errno));
626		verbose(VERB_QUERY, "drop user privileges, run as %s",
627			cfg->username);
628	}
629#endif /* HAVE_GETPWNAM */
630	/* file logging inited after chroot,chdir,setuid is done so that
631	 * it would succeed on SIGHUP as well */
632	if(!cfg->use_syslog)
633		log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
634}
635
636/**
637 * Run the daemon.
638 * @param cfgfile: the config file name.
639 * @param cmdline_verbose: verbosity resulting from commandline -v.
640 *    These increase verbosity as specified in the config file.
641 * @param debug_mode: if set, do not daemonize.
642 * @param log_default_identity: Default identity to report in logs
643 * @param need_pidfile: if false, no pidfile is checked or created.
644 */
645static void
646run_daemon(const char* cfgfile, int cmdline_verbose, int debug_mode, const char* log_default_identity, int need_pidfile)
647{
648	struct config_file* cfg = NULL;
649	struct daemon* daemon = NULL;
650	int done_setup = 0;
651
652	if(!(daemon = daemon_init()))
653		fatal_exit("alloc failure");
654	while(!daemon->need_to_exit) {
655		if(done_setup)
656			verbose(VERB_OPS, "Restart of %s.", PACKAGE_STRING);
657		else	verbose(VERB_OPS, "Start of %s.", PACKAGE_STRING);
658
659		/* config stuff */
660		if(!(cfg = config_create()))
661			fatal_exit("Could not alloc config defaults");
662		if(!config_read(cfg, cfgfile, daemon->chroot)) {
663			if(errno != ENOENT)
664				fatal_exit("Could not read config file: %s."
665					" Maybe try unbound -dd, it stays on "
666					"the commandline to see more errors, "
667					"or unbound-checkconf", cfgfile);
668			log_warn("Continuing with default config settings");
669		}
670		apply_settings(daemon, cfg, cmdline_verbose, debug_mode, log_default_identity);
671		if(!done_setup)
672			config_lookup_uid(cfg);
673
674		/* prepare */
675		if(!daemon_open_shared_ports(daemon))
676			fatal_exit("could not open ports");
677		if(!done_setup) {
678			perform_setup(daemon, cfg, debug_mode, &cfgfile, need_pidfile);
679			done_setup = 1;
680		} else {
681			/* reopen log after HUP to facilitate log rotation */
682			if(!cfg->use_syslog)
683				log_init(cfg->logfile, 0, cfg->chrootdir);
684		}
685		/* work */
686		daemon_fork(daemon);
687
688		/* clean up for restart */
689		verbose(VERB_ALGO, "cleanup.");
690		daemon_cleanup(daemon);
691		config_delete(cfg);
692	}
693	verbose(VERB_ALGO, "Exit cleanup.");
694	/* this unlink may not work if the pidfile is located outside
695	 * of the chroot/workdir or we no longer have permissions */
696	if(daemon->pidfile) {
697		int fd;
698		/* truncate pidfile */
699		fd = open(daemon->pidfile, O_WRONLY | O_TRUNC, 0644);
700		if(fd != -1)
701			close(fd);
702		/* delete pidfile */
703		unlink(daemon->pidfile);
704	}
705	daemon_delete(daemon);
706}
707
708/** getopt global, in case header files fail to declare it. */
709extern int optind;
710/** getopt global, in case header files fail to declare it. */
711extern char* optarg;
712
713/**
714 * main program. Set options given commandline arguments.
715 * @param argc: number of commandline arguments.
716 * @param argv: array of commandline arguments.
717 * @return: exit status of the program.
718 */
719int
720main(int argc, char* argv[])
721{
722	int c;
723	const char* cfgfile = CONFIGFILE;
724	const char* winopt = NULL;
725	const char* log_ident_default;
726	int cmdline_verbose = 0;
727	int debug_mode = 0;
728	int need_pidfile = 1;
729
730#ifdef UB_ON_WINDOWS
731	int cmdline_cfg = 0;
732#endif
733
734	log_init(NULL, 0, NULL);
735	log_ident_default = strrchr(argv[0],'/')?strrchr(argv[0],'/')+1:argv[0];
736	log_ident_set(log_ident_default);
737	/* parse the options */
738	while( (c=getopt(argc, argv, "c:dhpvw:V")) != -1) {
739		switch(c) {
740		case 'c':
741			cfgfile = optarg;
742#ifdef UB_ON_WINDOWS
743			cmdline_cfg = 1;
744#endif
745			break;
746		case 'v':
747			cmdline_verbose++;
748			verbosity++;
749			break;
750		case 'p':
751			need_pidfile = 0;
752			break;
753		case 'd':
754			debug_mode++;
755			break;
756		case 'w':
757			winopt = optarg;
758			break;
759		case 'V':
760			print_build_options();
761			return 0;
762		case '?':
763		case 'h':
764		default:
765			usage();
766			return 1;
767		}
768	}
769	argc -= optind;
770	/* argv += optind; not using further arguments */
771
772	if(winopt) {
773#ifdef UB_ON_WINDOWS
774		wsvc_command_option(winopt, cfgfile, cmdline_verbose,
775			cmdline_cfg);
776#else
777		fatal_exit("option not supported");
778#endif
779	}
780
781	if(argc != 0) {
782		usage();
783		return 1;
784	}
785
786	run_daemon(cfgfile, cmdline_verbose, debug_mode, log_ident_default, need_pidfile);
787	log_init(NULL, 0, NULL); /* close logfile */
788#ifndef unbound_testbound
789	if(log_get_lock()) {
790		lock_basic_destroy((lock_basic_type*)log_get_lock());
791	}
792#endif
793	return 0;
794}
795