aboutsummaryrefslogtreecommitdiff
path: root/contrib/openbsm/bin/auditd/auditd.c
blob: 86cf2335c28f3c9e31d6e45c43716840dddb849f (plain) (blame)
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
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
/*
 * Copyright (c) 2004 Apple Computer, Inc.
 * All rights reserved.
 *
 * @APPLE_BSD_LICENSE_HEADER_START@
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  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.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS 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.
 *
 * @APPLE_BSD_LICENSE_HEADER_END@
 *
 * $P4: //depot/projects/trustedbsd/openbsm/bin/auditd/auditd.c#21 $
 */

#include <sys/types.h>
#include <sys/dirent.h>
#include <sys/mman.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include <bsm/audit.h>
#include <bsm/audit_uevents.h>
#include <bsm/libbsm.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <syslog.h>

#include "auditd.h"

#define	NA_EVENT_STR_SIZE	25
#define	POL_STR_SIZE		128

static int	 ret, minval;
static char	*lastfile = NULL;
static int	 allhardcount = 0;
static int	 triggerfd = 0;
static int	 sigchlds, sigchlds_handled;
static int	 sighups, sighups_handled;
static int	 sigterms, sigterms_handled;

static TAILQ_HEAD(, dir_ent)	dir_q;

static int	config_audit_controls(void);

/*
 * Error starting auditd
 */
static void
fail_exit(void)
{

	audit_warn_nostart();
	exit(1);
}

/*
 * Free our local list of directory names.
 */
static void
free_dir_q(void)
{
	struct dir_ent *dirent;

	while ((dirent = TAILQ_FIRST(&dir_q))) {
		TAILQ_REMOVE(&dir_q, dirent, dirs);
		free(dirent->dirname);
		free(dirent);
	}
}

/*
 * Generate the timestamp string.
 */
static int
getTSstr(char *buf, int len)
{
	struct timeval ts;
	struct timezone tzp;
	time_t tt;

	if (gettimeofday(&ts, &tzp) != 0)
		return (-1);
	tt = (time_t)ts.tv_sec;
	if (!strftime(buf, len, "%Y%m%d%H%M%S", gmtime(&tt)))
		return (-1);
	return (0);
}

/*
 * Concat the directory name to the given file name.
 * XXX We should affix the hostname also
 */
static char *
affixdir(char *name, struct dir_ent *dirent)
{
	char *fn;
	char *curdir;
	const char *sep = "/";

	curdir = dirent->dirname;
	syslog(LOG_DEBUG, "dir = %s", dirent->dirname);

	fn = malloc(strlen(curdir) + strlen(sep) + (2 * POSTFIX_LEN) + 1);
	if (fn == NULL)
		return (NULL);
	strcpy(fn, curdir);
	strcat(fn, sep);
	strcat(fn, name);
	return (fn);
}

/*
 * Close the previous audit trail file.
 */
static int
close_lastfile(char *TS)
{
	char *ptr;
	char *oldname;

	if (lastfile != NULL) {
		oldname = (char *)malloc(strlen(lastfile) + 1);
		if (oldname == NULL)
			return (-1);
		strcpy(oldname, lastfile);

		/* Rename the last file -- append timestamp. */
		if ((ptr = strstr(lastfile, NOT_TERMINATED)) != NULL) {
			*ptr = '.';
			strcpy(ptr+1, TS);
			if (rename(oldname, lastfile) != 0)
				syslog(LOG_ERR,
				    "Could not rename %s to %s: %m", oldname,
				    lastfile);
			else
				syslog(LOG_INFO, "renamed %s to %s",
				    oldname, lastfile);
		}
		free(lastfile);
		free(oldname);
		lastfile = NULL;
	}
	return (0);
}

/*
 * Create the new audit file with appropriate permissions and ownership.  Try
 * to clean up if something goes wrong.
 */
static int
#ifdef AUDIT_REVIEW_GROUP
open_trail(const char *fname, uid_t uid, gid_t gid)
#else
open_trail(const char *fname)
#endif
{
	int error, fd;

	fd = open(fname, O_RDONLY | O_CREAT, S_IRUSR | S_IRGRP);
	if (fd < 0)
		return (-1);
#ifdef AUDIT_REVIEW_GROUP
	if (fchown(fd, uid, gid) < 0) {
		error = errno;
		close(fd);
		(void)unlink(fname);
		errno = error;
		return (-1);
	}
#endif
	return (fd);
}

/*
 * Create the new file name, swap with existing audit file.
 */
static int
swap_audit_file(void)
{
	char timestr[2 * POSTFIX_LEN];
	char *fn;
	char TS[POSTFIX_LEN];
	struct dir_ent *dirent;
#ifdef AUDIT_REVIEW_GROUP
	struct group *grp;
	gid_t gid;
	uid_t uid;
#endif
	int error, fd;

	if (getTSstr(TS, POSTFIX_LEN) != 0)
		return (-1);

	strcpy(timestr, TS);
	strcat(timestr, NOT_TERMINATED);

#ifdef AUDIT_REVIEW_GROUP
	/*
	 * XXXRW: Currently, this code falls back to the daemon gid, which is
	 * likely the wheel group.  Is there a better way to deal with this?
	 */
	grp = getgrnam(AUDIT_REVIEW_GROUP);
	if (grp == NULL) {
		syslog(LOG_INFO,
		    "Audit review group '%s' not available, using daemon gid",
		    AUDIT_REVIEW_GROUP);
		gid = -1;
	} else
		gid = grp->gr_gid;
	uid = getuid();
#endif

	/* Try until we succeed. */
	while ((dirent = TAILQ_FIRST(&dir_q))) {
		if ((fn = affixdir(timestr, dirent)) == NULL) {
			syslog(LOG_INFO, "Failed to swap log at time %s",
				timestr);
			return (-1);
		}

		/*
		 * Create and open the file; then close and pass to the
		 * kernel if all went well.
		 */
		syslog(LOG_INFO, "New audit file is %s", fn);
#ifdef AUDIT_REVIEW_GROUP
		fd = open_trail(fn, uid, gid);
#else
		fd = open_trail(fn);
#endif
		if (fd < 0)
			warn("open(%s)", fn);
		if (fd >= 0) {
			error = auditctl(fn);
			if (error) {
				syslog(LOG_ERR,
				    "auditctl failed setting log file! : %s",
				    strerror(errno));
				close(fd);
			} else {
				/* Success. */
				close_lastfile(TS);
				lastfile = fn;
				close(fd);
				return (0);
			}
		}

		/*
		 * Tell the administrator about lack of permissions for dir.
		 */
		audit_warn_getacdir(dirent->dirname);

		/* Try again with a different directory. */
		TAILQ_REMOVE(&dir_q, dirent, dirs);
		free(dirent->dirname);
		free(dirent);
	}
	syslog(LOG_ERR, "Log directories exhausted");
	return (-1);
}

/*
 * Read the audit_control file contents.
 */
static int
read_control_file(void)
{
	char cur_dir[MAXNAMLEN];
	struct dir_ent *dirent;
	au_qctrl_t qctrl;

	/*
	 * Clear old values.  Force a re-read of the file the next time.
	 */
	free_dir_q();
	endac();

	/*
	 * Read the list of directories into a local linked list.
	 *
	 * XXX We should use the reentrant interfaces once they are
	 * available.
	 */
	while (getacdir(cur_dir, MAXNAMLEN) >= 0) {
		dirent = (struct dir_ent *) malloc(sizeof(struct dir_ent));
		if (dirent == NULL)
			return (-1);
		dirent->softlim = 0;
		dirent->dirname = (char *) malloc(MAXNAMLEN);
		if (dirent->dirname == NULL) {
			free(dirent);
			return (-1);
		}
		strcpy(dirent->dirname, cur_dir);
		TAILQ_INSERT_TAIL(&dir_q, dirent, dirs);
	}

	allhardcount = 0;
	if (swap_audit_file() == -1) {
		syslog(LOG_ERR, "Could not swap audit file");
		/*
		 * XXX Faulty directory listing? - user should be given
		 * XXX an opportunity to change the audit_control file
		 * XXX switch to a reduced mode of auditing?
		 */
		return (-1);
	}

	/*
	 * XXX There are synchronization problems here
 	 * XXX what should we do if a trigger for the earlier limit
	 * XXX is generated here?
	 */
	if (0 == (ret = getacmin(&minval))) {
		syslog(LOG_DEBUG, "min free = %d", minval);
		if (auditon(A_GETQCTRL, &qctrl, sizeof(qctrl)) != 0) {
			syslog(LOG_ERR,
			    "could not get audit queue settings");
				return (-1);
		}
		qctrl.aq_minfree = minval;
		if (auditon(A_SETQCTRL, &qctrl, sizeof(qctrl)) != 0) {
			syslog(LOG_ERR,
			    "could not set audit queue settings");
			return (-1);
		}
	}

	return (0);
}

/*
 * Close all log files, control files, and tell the audit system.
 */
static int
close_all(void)
{
	struct auditinfo ai;
	int err_ret = 0;
	char TS[POSTFIX_LEN];
	int aufd;
	token_t *tok;
	long cond;

	/* Generate an audit record. */
	if ((aufd = au_open()) == -1)
		syslog(LOG_ERR, "Could not create audit shutdown event.");
	else {
		if ((tok = au_to_text("auditd::Audit shutdown")) != NULL)
			au_write(aufd, tok);
		/*
		 * XXX we need to implement extended subject tokens so we can
		 * effectively represent terminal lines with this token type.
		 */
		bzero(&ai, sizeof(ai));
		if ((tok = au_to_subject32(getuid(), geteuid(), getegid(),
		    getuid(), getgid(), getpid(), getpid(), &ai.ai_termid))
		    != NULL)
			au_write(aufd, tok);
		if ((tok = au_to_return32(0, 0)) != NULL)
			au_write(aufd, tok);
		if (au_close(aufd, 1, AUE_audit_shutdown) == -1)
			syslog(LOG_ERR,
			    "Could not close audit shutdown event.");
	}

	/* Flush contents. */
	cond = AUC_DISABLED;
	err_ret = auditon(A_SETCOND, &cond, sizeof(cond));
	if (err_ret != 0) {
		syslog(LOG_ERR, "Disabling audit failed! : %s",
		    strerror(errno));
		err_ret = 1;
	}
	if (getTSstr(TS, POSTFIX_LEN) == 0)
		close_lastfile(TS);
	if (lastfile != NULL)
		free(lastfile);

	free_dir_q();
	if ((remove(AUDITD_PIDFILE) == -1) || err_ret) {
		syslog(LOG_ERR, "Could not unregister");
		audit_warn_postsigterm();
		return (1);
	}
	endac();

	if (close(triggerfd) != 0)
		syslog(LOG_ERR, "Error closing control file");
	syslog(LOG_INFO, "Finished");
	return (0);
}

/*
 * When we get a signal, we are often not at a clean point.  So, little can
 * be done in the signal handler itself.  Instead,  we send a message to the
 * main servicing loop to do proper handling from a non-signal-handler
 * context.
 */
static void
relay_signal(int signal)
{

	if (signal == SIGHUP)
		sighups++;
	if (signal == SIGTERM)
		sigterms++;
	if (signal == SIGCHLD)
		sigchlds++;
}

/*
 * Registering the daemon.
 */
static int
register_daemon(void)
{
	FILE * pidfile;
	int fd;
	pid_t pid;

	/* Set up the signal hander. */
	if (signal(SIGTERM, relay_signal) == SIG_ERR) {
		syslog(LOG_ERR,
		    "Could not set signal handler for SIGTERM");
		fail_exit();
	}
	if (signal(SIGCHLD, relay_signal) == SIG_ERR) {
		syslog(LOG_ERR,
		    "Could not set signal handler for SIGCHLD");
		fail_exit();
	}
	if (signal(SIGHUP, relay_signal) == SIG_ERR) {
		syslog(LOG_ERR,
		    "Could not set signal handler for SIGHUP");
		fail_exit();
	}

	if ((pidfile = fopen(AUDITD_PIDFILE, "a")) == NULL) {
		syslog(LOG_ERR, "Could not open PID file");
		audit_warn_tmpfile();
		return (-1);
	}

	/* Attempt to lock the pid file; if a lock is present, exit. */
	fd = fileno(pidfile);
	if (flock(fd, LOCK_EX | LOCK_NB) < 0) {
		syslog(LOG_ERR,
		    "PID file is locked (is another auditd running?).");
		audit_warn_ebusy();
		return (-1);
	}

	pid = getpid();
	ftruncate(fd, 0);
	if (fprintf(pidfile, "%u\n", pid) < 0) {
		/* Should not start the daemon. */
		fail_exit();
	}

	fflush(pidfile);
	return (0);
}

/*
 * Handle the audit trigger event.
 *
 * We suppress (ignore) duplicated triggers in close succession in order to
 * try to avoid thrashing-like behavior.  However, not all triggers can be
 * ignored, as triggers generally represent edge triggers, not level
 * triggers, and won't be retransmitted if the condition persists.  Of
 * specific concern is the rotate trigger -- if one is dropped, then it will
 * not be retransmitted, and the log file will grow in an unbounded fashion.
 */
#define	DUPLICATE_INTERVAL	30
static void
handle_audit_trigger(int trigger)
{
	static int last_trigger, last_warning;
	static time_t last_time;
	struct dir_ent *dirent;
	struct timeval ts;
	struct timezone tzp;
	time_t tt;

	/*
	 * Suppress duplicate messages from the kernel within the specified
	 * interval.
	 */
	if (gettimeofday(&ts, &tzp) == 0) {
		tt = (time_t)ts.tv_sec;
		switch (trigger) {
		case AUDIT_TRIGGER_LOW_SPACE:
		case AUDIT_TRIGGER_NO_SPACE:
			/*
			 * Triggers we can suppress.  Of course, we also need
			 * to rate limit the warnings, so apply the same
			 * interval limit on syslog messages.
			 */
			if ((trigger == last_trigger) &&
			    (tt < (last_time + DUPLICATE_INTERVAL))) {
				if (tt >= (last_warning + DUPLICATE_INTERVAL))
					syslog(LOG_INFO,
					    "Suppressing duplicate trigger %d",
					    trigger);
				return;
			}
			last_warning = tt;
			break;

		case AUDIT_TRIGGER_ROTATE_KERNEL:
		case AUDIT_TRIGGER_ROTATE_USER:
		case AUDIT_TRIGGER_READ_FILE:
			/*
			 * Triggers that we cannot suppress.
			 */
			break;
		}

		/*
		 * Only update last_trigger after aborting due to a duplicate
		 * trigger, not before, or we will never allow that trigger
		 * again.
		 */
		last_trigger = trigger;
		last_time = tt;
	}

	/*
	 * Message processing is done here.
 	 */
	dirent = TAILQ_FIRST(&dir_q);
	switch(trigger) {
	case AUDIT_TRIGGER_LOW_SPACE:
		syslog(LOG_INFO, "Got low space trigger");
		if (dirent && (dirent->softlim != 1)) {
			TAILQ_REMOVE(&dir_q, dirent, dirs);
				/* Add this node to the end of the list. */
				TAILQ_INSERT_TAIL(&dir_q, dirent, dirs);
				audit_warn_soft(dirent->dirname);
				dirent->softlim = 1;

			if (TAILQ_NEXT(TAILQ_FIRST(&dir_q), dirs) != NULL &&
			    swap_audit_file() == -1)
				syslog(LOG_ERR, "Error swapping audit file");

			/*
			 * Check if the next dir has already reached its soft
			 * limit.
			 */
			dirent = TAILQ_FIRST(&dir_q);
			if (dirent->softlim == 1)  {
				/* All dirs have reached their soft limit. */
				audit_warn_allsoft();
			}
		} else {
			/*
			 * Continue auditing to the current file.  Also
			 * generate an allsoft warning.
			 *
			 * XXX do we want to do this ?
			 */
			audit_warn_allsoft();
		}
		break;

	case AUDIT_TRIGGER_NO_SPACE:
		syslog(LOG_INFO, "Got no space trigger");

		/* Delete current dir, go on to next. */
		TAILQ_REMOVE(&dir_q, dirent, dirs);
		audit_warn_hard(dirent->dirname);
		free(dirent->dirname);
		free(dirent);

		if (swap_audit_file() == -1)
			syslog(LOG_ERR, "Error swapping audit file");

		/* We are out of log directories. */
		audit_warn_allhard(++allhardcount);
		break;

	case AUDIT_TRIGGER_ROTATE_KERNEL:
	case AUDIT_TRIGGER_ROTATE_USER:
		/*
		 * Create a new file and swap with the one being used in
		 * kernel
		 */
		syslog(LOG_INFO, "Got open new trigger from %s", trigger ==
		    AUDIT_TRIGGER_ROTATE_KERNEL ? "kernel" : "user");
		if (swap_audit_file() == -1)
			syslog(LOG_ERR, "Error swapping audit file");
		break;

	case AUDIT_TRIGGER_READ_FILE:
		syslog(LOG_INFO, "Got read file trigger");
		if (read_control_file() == -1)
			syslog(LOG_ERR, "Error in audit control file");
		if (config_audit_controls() == -1)
			syslog(LOG_ERR, "Error setting audit controls");
		break;

	default:
		syslog(LOG_ERR, "Got unknown trigger %d", trigger);
		break;
	}
}

static void
handle_sighup(void)
{

	sighups_handled = sighups;
	config_audit_controls();
}

/*
 * Reap our children.
 */
static void
reap_children(void)
{
	pid_t child;
	int wstatus;

	while ((child = waitpid(-1, &wstatus, WNOHANG)) > 0) {
		if (!wstatus)
			continue;
		syslog(LOG_INFO, "warn process [pid=%d] %s %d.", child,
		    ((WIFEXITED(wstatus)) ? "exited with non-zero status" :
		    "exited as a result of signal"),
		    ((WIFEXITED(wstatus)) ? WEXITSTATUS(wstatus) :
		    WTERMSIG(wstatus)));
	}
}

static void
handle_sigchld(void)
{

	sigchlds_handled = sigchlds;
	reap_children();
}

/*
 * Read the control file for triggers/signals and handle appropriately.
 */
static int
wait_for_events(void)
{
	int num;
	unsigned int trigger;

	for (;;) {
		num = read(triggerfd, &trigger, sizeof(trigger));
		if ((num == -1) && (errno != EINTR)) {
			syslog(LOG_ERR, "%s: error %d", __FUNCTION__, errno);
			return (-1);
		}
		if (sigterms != sigterms_handled) {
			syslog(LOG_DEBUG, "%s: SIGTERM", __FUNCTION__);
			break;
		}
		if (sigchlds != sigchlds_handled)
			handle_sigchld();
		if (sighups != sighups_handled) {
			syslog(LOG_DEBUG, "%s: SIGHUP", __FUNCTION__);
			handle_sighup();
		}
		if ((num == -1) && (errno == EINTR))
			continue;
		if (num == 0) {
			syslog(LOG_ERR, "%s: read EOF", __FUNCTION__);
			return (-1);
		}
		if (trigger == AUDIT_TRIGGER_CLOSE_AND_DIE)
			break;
		else
			handle_audit_trigger(trigger);
	}
	return (close_all());
}

/*
 * Configure the audit controls in the kernel: the event to class mapping,
 * kernel preselection mask, etc.
 */
static int
config_audit_controls(void)
{
	au_event_ent_t ev, *evp;
	au_evclass_map_t evc_map;
	au_mask_t aumask;
	int ctr = 0;
	char naeventstr[NA_EVENT_STR_SIZE];
	char polstr[POL_STR_SIZE];
	long policy;

	/*
	 * Process the audit event file, obtaining a class mapping for each
	 * event, and send that mapping into the kernel.
	 *
	 * XXX There's a risk here that the BSM library will return NULL
	 * for an event when it can't properly map it to a class. In that
	 * case, we will not process any events beyond the one that failed,
	 * but should. We need a way to get a count of the events.
	*/
	ev.ae_name = (char *)malloc(AU_EVENT_NAME_MAX);
	ev.ae_desc = (char *)malloc(AU_EVENT_DESC_MAX);
	if ((ev.ae_name == NULL) || (ev.ae_desc == NULL)) {
		if (ev.ae_name != NULL)
			free(ev.ae_name);
		syslog(LOG_ERR,
		    "Memory allocation error when configuring audit controls.");
		return (-1);
	}

	/*
	 * XXXRW: Currently we have no way to remove mappings from the kernel
	 * when they are removed from the file-based mappings.
	 */
	evp = &ev;
	setauevent();
	while ((evp = getauevent_r(evp)) != NULL) {
		evc_map.ec_number = evp->ae_number;
		evc_map.ec_class = evp->ae_class;
		if (auditon(A_SETCLASS, &evc_map, sizeof(au_evclass_map_t))
		    != 0)
			syslog(LOG_ERR,
				"Failed to register class mapping for event %s",
				 evp->ae_name);
		else
			ctr++;
	}
	endauevent();
	free(ev.ae_name);
	free(ev.ae_desc);
	if (ctr == 0)
		syslog(LOG_ERR, "No events to class mappings registered.");
	else
		syslog(LOG_DEBUG, "Registered %d event to class mappings.",
		    ctr);

	/*
	 * Get the non-attributable event string and set the kernel mask from
	 * that.
	 */
	if ((getacna(naeventstr, NA_EVENT_STR_SIZE) == 0) &&
	    (getauditflagsbin(naeventstr, &aumask) == 0)) {
		if (auditon(A_SETKMASK, &aumask, sizeof(au_mask_t)))
			syslog(LOG_ERR,
			    "Failed to register non-attributable event mask.");
		else
			syslog(LOG_DEBUG,
			    "Registered non-attributable event mask.");
	} else
		syslog(LOG_ERR,
		    "Failed to obtain non-attributable event mask.");

	/*
	 * If a policy is configured in audit_control(5), implement the
	 * policy.  However, if one isn't defined, set AUDIT_CNT to avoid
	 * leaving the system in a fragile state.
	 */
	if ((getacpol(polstr, POL_STR_SIZE) == 0) &&
	    (au_strtopol(polstr, &policy) == 0)) {
		if (auditon(A_SETPOLICY, &policy, sizeof(policy)))
			syslog(LOG_ERR, "Failed to set audit policy: %m");
	} else {
		syslog(LOG_ERR, "Failed to obtain policy flags: %m");
		policy = AUDIT_CNT;
		if (auditon(A_SETPOLICY, &policy, sizeof(policy)))
			syslog(LOG_ERR,
			    "Failed to set default audit policy: %m");
	}

	return (0);
}

static void
setup(void)
{
	struct auditinfo ai;
	auditinfo_t auinfo;
	int aufd;
	token_t *tok;

	if ((triggerfd = open(AUDIT_TRIGGER_FILE, O_RDONLY, 0)) < 0) {
		syslog(LOG_ERR, "Error opening trigger file");
		fail_exit();
	}

	/*
	 * To provide event feedback cycles and avoid auditd becoming
	 * stalled if auditing is suspended, auditd and its children run
	 * without their events being audited.  We allow the uid, tid, and
	 * mask fields to be implicitly set to zero, but do set the pid.  We
	 * run this after opening the trigger device to avoid configuring
	 * audit state without audit present in the system.
	 *
	 * XXXRW: Is there more to it than this?
	 */
	bzero(&auinfo, sizeof(auinfo));
	auinfo.ai_asid = getpid();
	if (setaudit(&auinfo) == -1) {
		syslog(LOG_ERR, "Error setting audit stat");
		fail_exit();
	}

	TAILQ_INIT(&dir_q);
	if (read_control_file() == -1) {
		syslog(LOG_ERR, "Error reading control file");
		fail_exit();
	}

	/* Generate an audit record. */
	if ((aufd = au_open()) == -1)
		syslog(LOG_ERR, "Could not create audit startup event.");
	else {
		/*
		 * XXXCSJP Perhaps we wan't more robust audit records for
		 * audit start up and shutdown. This might include capturing
		 * failures to initialize the audit subsystem?
		 */
		bzero(&ai, sizeof(ai));
		if ((tok = au_to_subject32(getuid(), geteuid(), getegid(),
		    getuid(), getgid(), getpid(), getpid(), &ai.ai_termid))
		    != NULL)
			au_write(aufd, tok);
		if ((tok = au_to_text("auditd::Audit startup")) != NULL)
			au_write(aufd, tok);
		if ((tok = au_to_return32(0, 0)) != NULL)
			au_write(aufd, tok);
		if (au_close(aufd, 1, AUE_audit_startup) == -1)
			syslog(LOG_ERR,
			    "Could not close audit startup event.");
	}

	if (config_audit_controls() == 0)
		syslog(LOG_INFO, "Audit controls init successful");
	else
		syslog(LOG_ERR, "Audit controls init failed");
}

int
main(int argc, char **argv)
{
	int ch;
	int debug = 0;
	int rc;

	while ((ch = getopt(argc, argv, "dhs")) != -1) {
		switch(ch) {
		case 'd':
			/* Debug option. */
			debug = 1;
			break;

		case '?':
		default:
			(void)fprintf(stderr,
			    "usage: auditd [-d] \n");
			exit(1);
		}
	}

#ifdef LOG_SECURITY
	openlog("auditd", LOG_CONS | LOG_PID, LOG_SECURITY);
#else
	openlog("auditd", LOG_CONS | LOG_PID, LOG_AUTH);
#endif
	syslog(LOG_INFO, "starting...");

	if (debug == 0 && daemon(0, 0) == -1) {
		syslog(LOG_ERR, "Failed to daemonize");
		exit(1);
	}

	if (register_daemon() == -1) {
		syslog(LOG_ERR, "Could not register as daemon");
		exit(1);
	}

	setup();

	rc = wait_for_events();
	syslog(LOG_INFO, "auditd exiting.");

	exit(rc);
}