Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
/*
 * daemon/unbound.c - main program for unbound DNS resolver daemon.
 *
 * Copyright (c) 2007, NLnet Labs. All rights reserved.
 *
 * This software is open source.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of the NLNET LABS nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

/**
 * \file
 *
 * Main program to start the DNS resolver daemon.
 */

#include "config.h"
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#include <sys/time.h>
#include "util/log.h"
#include "daemon/daemon.h"
#include "daemon/remote.h"
#include "util/config_file.h"
#include "util/storage/slabhash.h"
#include "services/listen_dnsport.h"
#include "services/cache/rrset.h"
#include "services/cache/infra.h"
#include "util/fptr_wlist.h"
#include "util/data/msgreply.h"
#include "util/module.h"
#include "util/net_help.h"
#include "util/ub_event.h"
#include <signal.h>
#include <fcntl.h>
#include <openssl/crypto.h>
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#ifdef HAVE_GRP_H
#include <grp.h>
#endif
#include <openssl/ssl.h>

#ifndef S_SPLINT_S
/* splint chokes on this system header file */
#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif
#endif /* S_SPLINT_S */
#ifdef HAVE_LOGIN_CAP_H
#include <login_cap.h>
#endif

#ifdef UB_ON_WINDOWS
#  include "winrc/win_svc.h"
#endif

#ifdef HAVE_NSS
/* nss3 */
#  include "nss.h"
#endif

/** print build options. */
static void
print_build_options(void)
{
	const char** m;
	const char *evnm="event", *evsys="", *evmethod="";
	time_t t;
	struct timeval now;
	struct ub_event_base* base;
	printf("Version %s\n\n", PACKAGE_VERSION);
	printf("Configure line: %s\n", CONFCMDLINE);
	base = ub_default_event_base(0,&t,&now);
	ub_get_event_sys(base, &evnm, &evsys, &evmethod);
	printf("Linked libs: %s %s (it uses %s), %s\n",
		evnm, evsys, evmethod,
#ifdef HAVE_SSL
#  ifdef SSLEAY_VERSION
		SSLeay_version(SSLEAY_VERSION)
#  else
		OpenSSL_version(OPENSSL_VERSION)
#  endif
#elif defined(HAVE_NSS)
		NSS_GetVersion()
#elif defined(HAVE_NETTLE)
		"nettle"
#endif
		);
	printf("Linked modules:");
	for(m = module_list_avail(); *m; m++)
		printf(" %s", *m);
	printf("\n");
#ifdef USE_DNSCRYPT
	printf("DNSCrypt feature available\n");
#endif
#ifdef USE_TCP_FASTOPEN
	printf("TCP Fastopen feature available\n");
#endif
	ub_event_base_free(base);
	printf("\nBSD licensed, see LICENSE in source package for details.\n");
	printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
}

/** print usage. */
static void
usage(void)
{
	printf("usage:  unbound [options]\n");
	printf("	start unbound daemon DNS resolver.\n");
	printf("-h	this help.\n");
	printf("-c file	config file to read instead of %s\n", CONFIGFILE);
	printf("	file format is described in unbound.conf(5).\n");
	printf("-d	do not fork into the background.\n");
	printf("-p	do not create a pidfile.\n");
	printf("-v	verbose (more times to increase verbosity).\n");
	printf("-V	show version number and build options.\n");
#ifdef UB_ON_WINDOWS
	printf("-w opt	windows option: \n");
	printf("   	install, remove - manage the services entry\n");
	printf("   	service - used to start from services control panel\n");
#endif
	printf("\nVersion %s\n", PACKAGE_VERSION);
	printf("BSD licensed, see LICENSE in source package for details.\n");
	printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
}

#ifndef unbound_testbound
int replay_var_compare(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
{
        log_assert(0);
        return 0;
}
#endif

/** check file descriptor count */
static void
checkrlimits(struct config_file* cfg)
{
#ifndef S_SPLINT_S
#ifdef HAVE_GETRLIMIT
	/* list has number of ports to listen to, ifs number addresses */
	int list = ((cfg->do_udp?1:0) + (cfg->do_tcp?1 + 
			(int)cfg->incoming_num_tcp:0));
	size_t listen_ifs = (size_t)(cfg->num_ifs==0?
		((cfg->do_ip4 && !cfg->if_automatic?1:0) + 
		 (cfg->do_ip6?1:0)):cfg->num_ifs);
	size_t listen_num = list*listen_ifs;
	size_t outudpnum = (size_t)cfg->outgoing_num_ports;
	size_t outtcpnum = cfg->outgoing_num_tcp;
	size_t misc = 4; /* logfile, pidfile, stdout... */
	size_t perthread_noudp = listen_num + outtcpnum + 
		2/*cmdpipe*/ + 2/*libevent*/ + misc; 
	size_t perthread = perthread_noudp + outudpnum;

#if !defined(HAVE_PTHREAD) && !defined(HAVE_SOLARIS_THREADS)
	int numthread = 1; /* it forks */
#else
	int numthread = (cfg->num_threads?cfg->num_threads:1);
#endif
	size_t total = numthread * perthread + misc;
	size_t avail;
	struct rlimit rlim;

	if(total > 1024 && 
		strncmp(ub_event_get_version(), "mini-event", 10) == 0) {
		log_warn("too many file descriptors requested. The builtin"
			"mini-event cannot handle more than 1024. Config "
			"for less fds or compile with libevent");
		if(numthread*perthread_noudp+15 > 1024)
			fatal_exit("too much tcp. not enough fds.");
		cfg->outgoing_num_ports = (int)((1024 
			- numthread*perthread_noudp 
			- 10 /* safety margin */) /numthread);
		log_warn("continuing with less udp ports: %u",
			cfg->outgoing_num_ports);
		total = 1024;
	}
	if(perthread > 64 && 
		strncmp(ub_event_get_version(), "winsock-event", 13) == 0) {
		log_err("too many file descriptors requested. The winsock"
			" event handler cannot handle more than 64 per "
			" thread. Config for less fds");
		if(perthread_noudp+2 > 64)
			fatal_exit("too much tcp. not enough fds.");
		cfg->outgoing_num_ports = (int)((64 
			- perthread_noudp 
			- 2/* safety margin */));
		log_warn("continuing with less udp ports: %u",
			cfg->outgoing_num_ports);
		total = numthread*(perthread_noudp+
			(size_t)cfg->outgoing_num_ports)+misc;
	}
	if(getrlimit(RLIMIT_NOFILE, &rlim) < 0) {
		log_warn("getrlimit: %s", strerror(errno));
		return;
	}
	if(rlim.rlim_cur == (rlim_t)RLIM_INFINITY)
		return;
	if((size_t)rlim.rlim_cur < total) {
		avail = (size_t)rlim.rlim_cur;
		rlim.rlim_cur = (rlim_t)(total + 10);
		rlim.rlim_max = (rlim_t)(total + 10);
#ifdef HAVE_SETRLIMIT
		if(setrlimit(RLIMIT_NOFILE, &rlim) < 0) {
			log_warn("setrlimit: %s", strerror(errno));
#endif
			log_warn("cannot increase max open fds from %u to %u",
				(unsigned)avail, (unsigned)total+10);
			/* check that calculation below does not underflow,
			 * with 15 as margin */
			if(numthread*perthread_noudp+15 > avail)
				fatal_exit("too much tcp. not enough fds.");
			cfg->outgoing_num_ports = (int)((avail 
				- numthread*perthread_noudp 
				- 10 /* safety margin */) /numthread);
			log_warn("continuing with less udp ports: %u",
				cfg->outgoing_num_ports);
			log_warn("increase ulimit or decrease threads, "
				"ports in config to remove this warning");
			return;
#ifdef HAVE_SETRLIMIT
		}
#endif
		verbose(VERB_ALGO, "increased limit(open files) from %u to %u",
			(unsigned)avail, (unsigned)total+10);
	}
#else	
	(void)cfg;
#endif /* HAVE_GETRLIMIT */
#endif /* S_SPLINT_S */
}

/** set default logfile identity based on value from argv[0] at startup **/
static void
log_ident_set_fromdefault(struct config_file* cfg,
	const char *log_default_identity)
{
	if(cfg->log_identity == NULL || cfg->log_identity[0] == 0)
		log_ident_set(log_default_identity);
	else
		log_ident_set(cfg->log_identity);
}

/** set verbosity, check rlimits, cache settings */
static void
apply_settings(struct daemon* daemon, struct config_file* cfg, 
	int cmdline_verbose, int debug_mode, const char* log_default_identity)
{
	/* apply if they have changed */
	verbosity = cmdline_verbose + cfg->verbosity;
	if (debug_mode > 1) {
		cfg->use_syslog = 0;
		free(cfg->logfile);
		cfg->logfile = NULL;
	}
	daemon_apply_cfg(daemon, cfg);
	checkrlimits(cfg);

	if (cfg->use_systemd && cfg->do_daemonize) {
		log_warn("use-systemd and do-daemonize should not be enabled at the same time");
	}

	log_ident_set_fromdefault(cfg, log_default_identity);
}

#ifdef HAVE_KILL
/** Read existing pid from pidfile. 
 * @param file: file name of pid file.
 * @return: the pid from the file or -1 if none.
 */
static pid_t
readpid (const char* file)
{
	int fd;
	pid_t pid;
	char pidbuf[32];
	char* t;
	ssize_t l;

	if ((fd = open(file, O_RDONLY)) == -1) {
		if(errno != ENOENT)
			log_err("Could not read pidfile %s: %s",
				file, strerror(errno));
		return -1;
	}

	if (((l = read(fd, pidbuf, sizeof(pidbuf)))) == -1) {
		if(errno != ENOENT)
			log_err("Could not read pidfile %s: %s",
				file, strerror(errno));
		close(fd);
		return -1;
	}

	close(fd);

	/* Empty pidfile means no pidfile... */
	if (l == 0) {
		return -1;
	}

	pidbuf[sizeof(pidbuf)-1] = 0;
	pid = (pid_t)strtol(pidbuf, &t, 10);
	
	if (*t && *t != '\n') {
		return -1;
	}
	return pid;
}

/** write pid to file. 
 * @param pidfile: file name of pid file.
 * @param pid: pid to write to file.
 */
static void
writepid (const char* pidfile, pid_t pid)
{
	FILE* f;

	if ((f = fopen(pidfile, "w")) ==  NULL ) {
		log_err("cannot open pidfile %s: %s", 
			pidfile, strerror(errno));
		return;
	}
	if(fprintf(f, "%lu\n", (unsigned long)pid) < 0) {
		log_err("cannot write to pidfile %s: %s", 
			pidfile, strerror(errno));
	}
	fclose(f);
}

/**
 * check old pid file.
 * @param pidfile: the file name of the pid file.
 * @param inchroot: if pidfile is inchroot and we can thus expect to
 *	be able to delete it.
 */
static void
checkoldpid(char* pidfile, int inchroot)
{
	pid_t old;
	if((old = readpid(pidfile)) != -1) {
		/* see if it is still alive */
		if(kill(old, 0) == 0 || errno == EPERM)
			log_warn("unbound is already running as pid %u.", 
				(unsigned)old);
		else	if(inchroot)
			log_warn("did not exit gracefully last time (%u)", 
				(unsigned)old);
	}
}
#endif /* HAVE_KILL */

/** detach from command line */
static void
detach(void)
{
#if defined(HAVE_DAEMON) && !defined(DEPRECATED_DAEMON)
	/* use POSIX daemon(3) function */
	if(daemon(1, 0) != 0)
		fatal_exit("daemon failed: %s", strerror(errno));
#else /* no HAVE_DAEMON */
#ifdef HAVE_FORK
	int fd;
	/* Take off... */
	switch (fork()) {
		case 0:
			break;
		case -1:
			fatal_exit("fork failed: %s", strerror(errno));
		default:
			/* exit interactive session */
			exit(0);
	}
	/* detach */
#ifdef HAVE_SETSID
	if(setsid() == -1)
		fatal_exit("setsid() failed: %s", strerror(errno));
#endif
	if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
		(void)dup2(fd, STDIN_FILENO);
		(void)dup2(fd, STDOUT_FILENO);
		(void)dup2(fd, STDERR_FILENO);
		if (fd > 2)
			(void)close(fd);
	}
#endif /* HAVE_FORK */
#endif /* HAVE_DAEMON */
}

/** daemonize, drop user privileges and chroot if needed */
static void
perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
	const char** cfgfile, int need_pidfile)
{
#ifdef HAVE_KILL
	int pidinchroot;
#endif
#ifdef HAVE_GETPWNAM
	struct passwd *pwd = NULL;

	if(cfg->username && cfg->username[0]) {
		if((pwd = getpwnam(cfg->username)) == NULL)
			fatal_exit("user '%s' does not exist.", cfg->username);
		/* endpwent below, in case we need pwd for setusercontext */
	}
#endif
#ifdef UB_ON_WINDOWS
	w_config_adjust_directory(cfg);
#endif

	/* read ssl keys while superuser and outside chroot */
#ifdef HAVE_SSL
	if(!(daemon->rc = daemon_remote_create(cfg)))
		fatal_exit("could not set up remote-control");
	if(cfg->ssl_service_key && cfg->ssl_service_key[0]) {
		if(!(daemon->listen_sslctx = listen_sslctx_create(
			cfg->ssl_service_key, cfg->ssl_service_pem, NULL)))
			fatal_exit("could not set up listen SSL_CTX");
		if(cfg->tls_ciphers && cfg->tls_ciphers[0]) {
			if (!SSL_CTX_set_cipher_list(daemon->listen_sslctx, cfg->tls_ciphers)) {
				fatal_exit("failed to set tls-cipher %s", cfg->tls_ciphers);
			}
		}
#ifdef HAVE_SSL_CTX_SET_CIPHERSUITES
		if(cfg->tls_ciphersuites && cfg->tls_ciphersuites[0]) {
			if (!SSL_CTX_set_ciphersuites(daemon->listen_sslctx, cfg->tls_ciphersuites)) {
				fatal_exit("failed to set tls-ciphersuites %s", cfg->tls_ciphersuites);
			}
		}
#endif
		if(cfg->tls_session_ticket_keys.first &&
			cfg->tls_session_ticket_keys.first->str[0] != 0) {
			if(!listen_sslctx_setup_ticket_keys(daemon->listen_sslctx, cfg->tls_session_ticket_keys.first)) {
				fatal_exit("could not set session ticket SSL_CTX");
			}
		}
	}
	if(!(daemon->connect_sslctx = connect_sslctx_create(NULL, NULL,
		cfg->tls_cert_bundle, cfg->tls_win_cert)))
		fatal_exit("could not set up connect SSL_CTX");
#endif

	/* init syslog (as root) if needed, before daemonize, otherwise
	 * a fork error could not be printed since daemonize closed stderr.*/
	if(cfg->use_syslog) {
		log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
	}
	/* if using a logfile, we cannot open it because the logfile would
	 * be created with the wrong permissions, we cannot chown it because
	 * we cannot chown system logfiles, so we do not open at all.
	 * So, using a logfile, the user does not see errors unless -d is
	 * given to unbound on the commandline. */

#ifdef HAVE_KILL
	/* true if pidfile is inside chrootdir, or nochroot */
	pidinchroot = need_pidfile && (!(cfg->chrootdir && cfg->chrootdir[0]) ||
				(cfg->chrootdir && cfg->chrootdir[0] &&
				strncmp(cfg->pidfile, cfg->chrootdir,
				strlen(cfg->chrootdir))==0));

	/* check old pid file before forking */
	if(cfg->pidfile && cfg->pidfile[0] && need_pidfile) {
		/* calculate position of pidfile */
		if(cfg->pidfile[0] == '/')
			daemon->pidfile = strdup(cfg->pidfile);
		else	daemon->pidfile = fname_after_chroot(cfg->pidfile, 
				cfg, 1);
		if(!daemon->pidfile)
			fatal_exit("pidfile alloc: out of memory");
		checkoldpid(daemon->pidfile, pidinchroot);
	}
#endif

	/* daemonize because pid is needed by the writepid func */
	if(!debug_mode && cfg->do_daemonize) {
		detach();
	}

	/* write new pidfile (while still root, so can be outside chroot) */
#ifdef HAVE_KILL
	if(cfg->pidfile && cfg->pidfile[0] && need_pidfile) {
		writepid(daemon->pidfile, getpid());
		if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1 &&
			pidinchroot) {
#  ifdef HAVE_CHOWN
			if(chown(daemon->pidfile, cfg_uid, cfg_gid) == -1) {
				verbose(VERB_QUERY, "cannot chown %u.%u %s: %s",
					(unsigned)cfg_uid, (unsigned)cfg_gid,
					daemon->pidfile, strerror(errno));
			}
#  endif /* HAVE_CHOWN */
		}
	}
#else
	(void)daemon;
	(void)need_pidfile;
#endif /* HAVE_KILL */

	/* Set user context */
#ifdef HAVE_GETPWNAM
	if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1) {
#ifdef HAVE_SETUSERCONTEXT
		/* setusercontext does initgroups, setuid, setgid, and
		 * also resource limits from login config, but we
		 * still call setresuid, setresgid to be sure to set all uid*/
		if(setusercontext(NULL, pwd, cfg_uid, (unsigned)
			LOGIN_SETALL & ~LOGIN_SETUSER & ~LOGIN_SETGROUP) != 0)
			log_warn("unable to setusercontext %s: %s",
				cfg->username, strerror(errno));
#endif /* HAVE_SETUSERCONTEXT */
	}
#endif /* HAVE_GETPWNAM */

	/* box into the chroot */
#ifdef HAVE_CHROOT
	if(cfg->chrootdir && cfg->chrootdir[0]) {
		if(chdir(cfg->chrootdir)) {
			fatal_exit("unable to chdir to chroot %s: %s",
				cfg->chrootdir, strerror(errno));
		}
		verbose(VERB_QUERY, "chdir to %s", cfg->chrootdir);
		if(chroot(cfg->chrootdir))
			fatal_exit("unable to chroot to %s: %s", 
				cfg->chrootdir, strerror(errno));
		if(chdir("/"))
			fatal_exit("unable to chdir to / in chroot %s: %s",
				cfg->chrootdir, strerror(errno));
		verbose(VERB_QUERY, "chroot to %s", cfg->chrootdir);
		if(strncmp(*cfgfile, cfg->chrootdir, 
			strlen(cfg->chrootdir)) == 0) 
			(*cfgfile) += strlen(cfg->chrootdir);

		/* adjust stored pidfile for chroot */
		if(daemon->pidfile && daemon->pidfile[0] && 
			strncmp(daemon->pidfile, cfg->chrootdir,
			strlen(cfg->chrootdir))==0) {
			char* old = daemon->pidfile;
			daemon->pidfile = strdup(old+strlen(cfg->chrootdir));
			free(old);
			if(!daemon->pidfile)
				log_err("out of memory in pidfile adjust");
		}
		daemon->chroot = strdup(cfg->chrootdir);
		if(!daemon->chroot)
			log_err("out of memory in daemon chroot dir storage");
	}
#else
	(void)cfgfile;
#endif
	/* change to working directory inside chroot */
	if(cfg->directory && cfg->directory[0]) {
		char* dir = cfg->directory;
		if(cfg->chrootdir && cfg->chrootdir[0] &&
			strncmp(dir, cfg->chrootdir, 
			strlen(cfg->chrootdir)) == 0)
			dir += strlen(cfg->chrootdir);
		if(dir[0]) {
			if(chdir(dir)) {
				fatal_exit("Could not chdir to %s: %s",
					dir, strerror(errno));
			}
			verbose(VERB_QUERY, "chdir to %s", dir);
		}
	}

	/* drop permissions after chroot, getpwnam, pidfile, syslog done*/
#ifdef HAVE_GETPWNAM
	if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1) {
#  ifdef HAVE_INITGROUPS
		if(initgroups(cfg->username, cfg_gid) != 0)
			log_warn("unable to initgroups %s: %s",
				cfg->username, strerror(errno));
#  endif /* HAVE_INITGROUPS */
#  ifdef HAVE_ENDPWENT
		endpwent();
#  endif

#ifdef HAVE_SETRESGID
		if(setresgid(cfg_gid,cfg_gid,cfg_gid) != 0)
#elif defined(HAVE_SETREGID) && !defined(DARWIN_BROKEN_SETREUID)
		if(setregid(cfg_gid,cfg_gid) != 0)
#else /* use setgid */
		if(setgid(cfg_gid) != 0)
#endif /* HAVE_SETRESGID */
			fatal_exit("unable to set group id of %s: %s", 
				cfg->username, strerror(errno));
#ifdef HAVE_SETRESUID
		if(setresuid(cfg_uid,cfg_uid,cfg_uid) != 0)
#elif defined(HAVE_SETREUID) && !defined(DARWIN_BROKEN_SETREUID)
		if(setreuid(cfg_uid,cfg_uid) != 0)
#else /* use setuid */
		if(setuid(cfg_uid) != 0)
#endif /* HAVE_SETRESUID */
			fatal_exit("unable to set user id of %s: %s", 
				cfg->username, strerror(errno));
		verbose(VERB_QUERY, "drop user privileges, run as %s", 
			cfg->username);
	}
#endif /* HAVE_GETPWNAM */
	/* file logging inited after chroot,chdir,setuid is done so that 
	 * it would succeed on SIGHUP as well */
	if(!cfg->use_syslog)
		log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
}

/**
 * Run the daemon. 
 * @param cfgfile: the config file name.
 * @param cmdline_verbose: verbosity resulting from commandline -v.
 *    These increase verbosity as specified in the config file.
 * @param debug_mode: if set, do not daemonize.
 * @param log_default_identity: Default identity to report in logs
 * @param need_pidfile: if false, no pidfile is checked or created.
 */
static void 
run_daemon(const char* cfgfile, int cmdline_verbose, int debug_mode, const char* log_default_identity, int need_pidfile)
{
	struct config_file* cfg = NULL;
	struct daemon* daemon = NULL;
	int done_setup = 0;

	if(!(daemon = daemon_init()))
		fatal_exit("alloc failure");
	while(!daemon->need_to_exit) {
		if(done_setup)
			verbose(VERB_OPS, "Restart of %s.", PACKAGE_STRING);
		else	verbose(VERB_OPS, "Start of %s.", PACKAGE_STRING);

		/* config stuff */
		if(!(cfg = config_create()))
			fatal_exit("Could not alloc config defaults");
		if(!config_read(cfg, cfgfile, daemon->chroot)) {
			if(errno != ENOENT)
				fatal_exit("Could not read config file: %s."
					" Maybe try unbound -dd, it stays on "
					"the commandline to see more errors, "
					"or unbound-checkconf", cfgfile);
			log_warn("Continuing with default config settings");
		}
		apply_settings(daemon, cfg, cmdline_verbose, debug_mode, log_default_identity);
		if(!done_setup)
			config_lookup_uid(cfg);
	
		/* prepare */
		if(!daemon_open_shared_ports(daemon))
			fatal_exit("could not open ports");
		if(!done_setup) { 
			perform_setup(daemon, cfg, debug_mode, &cfgfile, need_pidfile);
			done_setup = 1; 
		} else {
			/* reopen log after HUP to facilitate log rotation */
			if(!cfg->use_syslog)
				log_init(cfg->logfile, 0, cfg->chrootdir);
		}
		/* work */
		daemon_fork(daemon);

		/* clean up for restart */
		verbose(VERB_ALGO, "cleanup.");
		daemon_cleanup(daemon);
		config_delete(cfg);
	}
	verbose(VERB_ALGO, "Exit cleanup.");
	/* this unlink may not work if the pidfile is located outside
	 * of the chroot/workdir or we no longer have permissions */
	if(daemon->pidfile) {
		int fd;
		/* truncate pidfile */
		fd = open(daemon->pidfile, O_WRONLY | O_TRUNC, 0644);
		if(fd != -1)
			close(fd);
		/* delete pidfile */
		unlink(daemon->pidfile);
	}
	daemon_delete(daemon);
}

/** getopt global, in case header files fail to declare it. */
extern int optind;
/** getopt global, in case header files fail to declare it. */
extern char* optarg;

/**
 * main program. Set options given commandline arguments.
 * @param argc: number of commandline arguments.
 * @param argv: array of commandline arguments.
 * @return: exit status of the program.
 */
int 
main(int argc, char* argv[])
{
	int c;
	const char* cfgfile = CONFIGFILE;
	const char* winopt = NULL;
	const char* log_ident_default;
	int cmdline_verbose = 0;
	int debug_mode = 0;
	int need_pidfile = 1;

#ifdef UB_ON_WINDOWS
	int cmdline_cfg = 0;
#endif

	log_init(NULL, 0, NULL);
	log_ident_default = strrchr(argv[0],'/')?strrchr(argv[0],'/')+1:argv[0];
	log_ident_set(log_ident_default);
	/* parse the options */
	while( (c=getopt(argc, argv, "c:dhpvw:V")) != -1) {
		switch(c) {
		case 'c':
			cfgfile = optarg;
#ifdef UB_ON_WINDOWS
			cmdline_cfg = 1;
#endif
			break;
		case 'v':
			cmdline_verbose++;
			verbosity++;
			break;
		case 'p':
			need_pidfile = 0;
			break;
		case 'd':
			debug_mode++;
			break;
		case 'w':
			winopt = optarg;
			break;
		case 'V':
			print_build_options();
			return 0;
		case '?':
		case 'h':
		default:
			usage();
			return 1;
		}
	}
	argc -= optind;
	/* argv += optind; not using further arguments */

	if(winopt) {
#ifdef UB_ON_WINDOWS
		wsvc_command_option(winopt, cfgfile, cmdline_verbose, 
			cmdline_cfg);
#else
		fatal_exit("option not supported");
#endif
	}

	if(argc != 0) {
		usage();
		return 1;
	}

	run_daemon(cfgfile, cmdline_verbose, debug_mode, log_ident_default, need_pidfile);
	log_init(NULL, 0, NULL); /* close logfile */
#ifndef unbound_testbound
	if(log_get_lock()) {
		lock_basic_destroy((lock_basic_type*)log_get_lock());
	}
#endif
	return 0;
}