xref: /dragonfly/usr.sbin/pflogd/pflogd.c (revision 560e4370) 
1 /*	$OpenBSD: pflogd.c,v 1.45 2007/06/06 14:11:26 henning Exp $	*/
2 
3 /*
4  * Copyright (c) 2001 Theo de Raadt
5  * Copyright (c) 2001 Can Erkin Acar
6  * All rights reserved.
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
13  *      notice, this list of conditions and the following disclaimer.
14  *    - Redistributions in binary form must reproduce the above
15  *      copyright notice, this list of conditions and the following
16  *      disclaimer in the documentation and/or other materials provided
17  *      with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
22  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
23  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
25  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
27  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
29  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include <sys/types.h>
34 #include <sys/ioctl.h>
35 #include <sys/file.h>
36 #include <sys/stat.h>
37 #include <sys/socket.h>
38 #include <net/if.h>
39 
40 #include <machine/inttypes.h>
41 
42 #include <errno.h>
43 #include <err.h>
44 #include <fcntl.h>
45 #include <syslog.h>
46 #include <signal.h>
47 #include <stdarg.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 
53 #include <libutil.h>
54 #include <pcap-int.h>
55 #include <pcap.h>
56 
57 #include "pflogd.h"
58 
59 pcap_t *hpcap;
60 static FILE *dpcap;
61 
62 int Debug = 0;
63 static int snaplen = DEF_SNAPLEN;
64 static int cur_snaplen = DEF_SNAPLEN;
65 
66 volatile sig_atomic_t gotsig_close, gotsig_alrm, gotsig_hup, gotsig_usr1;
67 
68 const char *filename = PFLOGD_LOG_FILE;
69 const char *interface = PFLOGD_DEFAULT_IF;
70 char *filter = NULL;
71 
72 char errbuf[PCAP_ERRBUF_SIZE];
73 
74 int log_debug = 0;
75 unsigned int delay = FLUSH_DELAY;
76 
77 char *copy_argv(char * const *);
78 void  dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
79 void  dump_packet_nobuf(u_char *, const struct pcap_pkthdr *, const u_char *);
80 void  log_pcap_stats(void);
81 int   flush_buffer(FILE *);
82 int   if_exists(char *);
83 int   init_pcap(void);
84 void  logmsg(int, const char *, ...) __printflike(2, 3);
85 void  purge_buffer(void);
86 int   reset_dump(int);
87 int   scan_dump(FILE *, off_t);
88 int   set_snaplen(int);
89 void  set_suspended(int);
90 void  sig_alrm(int);
91 void  sig_usr1(int);
92 void  sig_close(int);
93 void  sig_hup(int);
94 void  usage(void) __dead2;
95 
96 static int try_reset_dump(int);
97 
98 /* buffer must always be greater than snaplen */
99 static int    bufpkt = 0;	/* number of packets in buffer */
100 static size_t buflen = 0;	/* allocated size of buffer */
101 static char  *buffer = NULL;	/* packet buffer */
102 static char  *bufpos = NULL;	/* position in buffer */
103 static size_t bufleft = 0;	/* bytes left in buffer */
104 
105 /* if error, stop logging but count dropped packets */
106 static int suspended = -1;
107 static long packets_dropped = 0;
108 
109 void
110 set_suspended(int s)
111 {
112 	if (suspended == s)
113 		return;
114 
115 	suspended = s;
116 	setproctitle("[%s] -s %d -i %s -f %s",
117 	    suspended ? "suspended" : "running",
118 	    cur_snaplen, interface, filename);
119 }
120 
121 char *
122 copy_argv(char * const *argv)
123 {
124 	size_t len = 0, n;
125 	char *buf;
126 
127 	if (argv == NULL)
128 		return (NULL);
129 
130 	for (n = 0; argv[n]; n++)
131 		len += strlen(argv[n])+1;
132 	if (len == 0)
133 		return (NULL);
134 
135 	buf = malloc(len);
136 	if (buf == NULL)
137 		return (NULL);
138 
139 	strlcpy(buf, argv[0], len);
140 	for (n = 1; argv[n]; n++) {
141 		strlcat(buf, " ", len);
142 		strlcat(buf, argv[n], len);
143 	}
144 	return (buf);
145 }
146 
147 void
148 logmsg(int pri, const char *message, ...)
149 {
150 	va_list ap;
151 	va_start(ap, message);
152 
153 	if (log_debug) {
154 		vfprintf(stderr, message, ap);
155 		fprintf(stderr, "\n");
156 	} else
157 		vsyslog(pri, message, ap);
158 	va_end(ap);
159 }
160 
161 void
162 usage(void)
163 {
164 	fprintf(stderr, "usage: pflogd [-Dx] [-d delay] [-f filename]");
165 	fprintf(stderr, " [-i interface] [-p pidfile]\n");
166 	fprintf(stderr, "              [-s snaplen] [expression]\n");
167 	exit(1);
168 }
169 
170 void
171 sig_close(int sig __unused)
172 {
173 	gotsig_close = 1;
174 }
175 
176 void
177 sig_hup(int sig __unused)
178 {
179 	gotsig_hup = 1;
180 }
181 
182 void
183 sig_alrm(int sig __unused)
184 {
185 	gotsig_alrm = 1;
186 }
187 
188 void
189 sig_usr1(int sig __unused)
190 {
191 	gotsig_usr1 = 1;
192 }
193 
194 void
195 set_pcap_filter(void)
196 {
197 	struct bpf_program bprog;
198 
199 	if (pcap_compile(hpcap, &bprog, filter, PCAP_OPT_FIL, 0) < 0)
200 		logmsg(LOG_WARNING, "%s", pcap_geterr(hpcap));
201 	else {
202 		if (pcap_setfilter(hpcap, &bprog) < 0)
203 			logmsg(LOG_WARNING, "%s", pcap_geterr(hpcap));
204 		pcap_freecode(&bprog);
205 	}
206 }
207 
208 int
209 if_exists(char *ifname)
210 {
211 	int s;
212 	struct ifreq ifr;
213 	struct if_data ifrdat;
214 
215 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
216 		err(1, "socket");
217 	bzero(&ifr, sizeof(ifr));
218 	if (strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)) >=
219 		sizeof(ifr.ifr_name))
220 			errx(1, "main ifr_name: strlcpy");
221 	ifr.ifr_data = (caddr_t)&ifrdat;
222 	if (ioctl(s, SIOCGIFDATA, (caddr_t)&ifr) == -1)
223 		return (0);
224 	if (close(s))
225 		err(1, "close");
226 
227 	return (1);
228 }
229 
230 int
231 init_pcap(void)
232 {
233 	hpcap = pcap_open_live(interface, snaplen, 1, PCAP_TO_MS, errbuf);
234 	if (hpcap == NULL) {
235 		logmsg(LOG_ERR, "Failed to initialize: %s", errbuf);
236 		return (-1);
237 	}
238 
239 	if (pcap_datalink(hpcap) != DLT_PFLOG) {
240 		logmsg(LOG_ERR, "Invalid datalink type");
241 		pcap_close(hpcap);
242 		hpcap = NULL;
243 		return (-1);
244 	}
245 
246 	set_pcap_filter();
247 
248 	cur_snaplen = snaplen = pcap_snapshot(hpcap);
249 
250 	/* From contrib/pf/pflogd.c 1.5 FreeBSD: BPF locking is not
251 	 * (yet) supported.
252 	 */
253 	#ifndef __DragonFly__
254 	/* lock */
255 	if (ioctl(pcap_fileno(hpcap), BIOCLOCK) < 0) {
256 		logmsg(LOG_ERR, "BIOCLOCK: %s", strerror(errno));
257 		return (-1);
258 	}
259 	#endif
260 
261 	return (0);
262 }
263 
264 int
265 set_snaplen(int snap)
266 {
267 	if (priv_set_snaplen(snap))
268 		return (1);
269 
270 	if (cur_snaplen > snap)
271 		purge_buffer();
272 
273 	cur_snaplen = snap;
274 
275 	return (0);
276 }
277 
278 int
279 reset_dump(int nomove)
280 {
281 	int ret;
282 
283 	for (;;) {
284 		ret = try_reset_dump(nomove);
285 		if (ret <= 0)
286 			break;
287 	}
288 
289 	return (ret);
290 }
291 
292 /*
293  * tries to (re)open log file, nomove flag is used with -x switch
294  * returns 0: success, 1: retry (log moved), -1: error
295  */
296 int
297 try_reset_dump(int nomove)
298 {
299 	struct pcap_file_header hdr;
300 	struct stat st;
301 	int fd;
302 	FILE *fp;
303 
304 	if (hpcap == NULL)
305 		return (-1);
306 
307 	if (dpcap) {
308 		flush_buffer(dpcap);
309 		fclose(dpcap);
310 		dpcap = NULL;
311 	}
312 
313 	/*
314 	 * Basically reimplement pcap_dump_open() because it truncates
315 	 * files and duplicates headers and such.
316 	 */
317 	fd = priv_open_log();
318 	if (fd < 0)
319 		return (-1);
320 
321 	fp = fdopen(fd, "a+");
322 
323 	if (fp == NULL) {
324 		logmsg(LOG_ERR, "Error: %s: %s", filename, strerror(errno));
325 		close(fd);
326 		return (-1);
327 	}
328 	if (fstat(fileno(fp), &st) == -1) {
329 		logmsg(LOG_ERR, "Error: %s: %s", filename, strerror(errno));
330 		fclose(fp);
331 		return (-1);
332 	}
333 
334 	/* set FILE unbuffered, we do our own buffering */
335 	if (setvbuf(fp, NULL, _IONBF, 0)) {
336 		logmsg(LOG_ERR, "Failed to set output buffers");
337 		fclose(fp);
338 		return (-1);
339 	}
340 
341 #define TCPDUMP_MAGIC 0xa1b2c3d4
342 
343 	if (st.st_size == 0) {
344 		if (snaplen != cur_snaplen) {
345 			logmsg(LOG_NOTICE, "Using snaplen %d", snaplen);
346 			if (set_snaplen(snaplen))
347 				logmsg(LOG_WARNING,
348 				    "Failed, using old settings");
349 		}
350 		hdr.magic = TCPDUMP_MAGIC;
351 		hdr.version_major = PCAP_VERSION_MAJOR;
352 		hdr.version_minor = PCAP_VERSION_MINOR;
353 		hdr.thiszone = hpcap->tzoff;
354 		hdr.snaplen = hpcap->snapshot;
355 		hdr.sigfigs = 0;
356 		hdr.linktype = hpcap->linktype;
357 
358 		if (fwrite((char *)&hdr, sizeof(hdr), 1, fp) != 1) {
359 			fclose(fp);
360 			return (-1);
361 		}
362 	} else if (scan_dump(fp, st.st_size)) {
363 		fclose(fp);
364 		if (nomove || priv_move_log()) {
365 			logmsg(LOG_ERR,
366 			    "Invalid/incompatible log file, move it away");
367 			return (-1);
368 		}
369 		return (1);
370 	}
371 
372 	dpcap = fp;
373 
374 	set_suspended(0);
375 	flush_buffer(fp);
376 
377 	return (0);
378 }
379 
380 int
381 scan_dump(FILE *fp, off_t size)
382 {
383 	struct pcap_file_header hdr;
384 	struct pcap_sf_pkthdr ph;
385 	off_t pos;
386 
387 	/*
388 	 * Must read the file, compare the header against our new
389 	 * options (in particular, snaplen) and adjust our options so
390 	 * that we generate a correct file. Furthermore, check the file
391 	 * for consistency so that we can append safely.
392 	 *
393 	 * XXX this may take a long time for large logs.
394 	 */
395 	fseek(fp, 0L, SEEK_SET);
396 
397 	if (fread((char *)&hdr, sizeof(hdr), 1, fp) != 1) {
398 		logmsg(LOG_ERR, "Short file header");
399 		return (1);
400 	}
401 
402 	if (hdr.magic != TCPDUMP_MAGIC ||
403 	    hdr.version_major != PCAP_VERSION_MAJOR ||
404 	    hdr.version_minor != PCAP_VERSION_MINOR ||
405 	    (int)hdr.linktype != hpcap->linktype ||
406 	    hdr.snaplen > PFLOGD_MAXSNAPLEN) {
407 		return (1);
408 	}
409 
410 	pos = sizeof(hdr);
411 
412 	while (!feof(fp)) {
413 		off_t len = fread((char *)&ph, 1, sizeof(ph), fp);
414 		if (len == 0)
415 			break;
416 
417 		if (len != sizeof(ph))
418 			goto error;
419 		if (ph.caplen > hdr.snaplen || ph.caplen > PFLOGD_MAXSNAPLEN)
420 			goto error;
421 		pos += sizeof(ph) + ph.caplen;
422 		if (pos > size)
423 			goto error;
424 		fseek(fp, ph.caplen, SEEK_CUR);
425 	}
426 
427 	if (pos != size)
428 		goto error;
429 
430 	if ((int)hdr.snaplen != cur_snaplen) {
431 		logmsg(LOG_WARNING,
432 		       "Existing file has different snaplen %u, using it",
433 		       hdr.snaplen);
434 		if (set_snaplen(hdr.snaplen)) {
435 			logmsg(LOG_WARNING,
436 			       "Failed, using old settings, offset %llu",
437 			       (unsigned long long) size);
438 		}
439 	}
440 
441 	return (0);
442 
443  error:
444 	logmsg(LOG_ERR, "Corrupted log file.");
445 	return (1);
446 }
447 
448 /* dump a packet directly to the stream, which is unbuffered */
449 void
450 dump_packet_nobuf(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
451 {
452 	FILE *f = (FILE *)user;
453 	struct pcap_sf_pkthdr sh;
454 
455 	if (suspended) {
456 		packets_dropped++;
457 		return;
458 	}
459 
460 	sh.ts.tv_sec = (bpf_int32)h->ts.tv_sec;
461 	sh.ts.tv_usec = (bpf_int32)h->ts.tv_usec;
462 	sh.caplen = h->caplen;
463 	sh.len = h->len;
464 
465 	if (fwrite((char *)&sh, sizeof(sh), 1, f) != 1) {
466 		off_t pos = ftello(f);
467 
468 		/* try to undo header to prevent corruption */
469 		if ((size_t)pos < sizeof(sh) ||
470 		    ftruncate(fileno(f), pos - sizeof(sh))) {
471 			logmsg(LOG_ERR, "Write failed, corrupted logfile!");
472 			set_suspended(1);
473 			gotsig_close = 1;
474 			return;
475 		}
476 		goto error;
477 	}
478 
479 	if (fwrite(sp, h->caplen, 1, f) != 1)
480 		goto error;
481 
482 	return;
483 
484 error:
485 	set_suspended(1);
486 	packets_dropped ++;
487 	logmsg(LOG_ERR, "Logging suspended: fwrite: %s", strerror(errno));
488 }
489 
490 int
491 flush_buffer(FILE *f)
492 {
493 	off_t offset;
494 	int len = bufpos - buffer;
495 
496 	if (len <= 0)
497 		return (0);
498 
499 	offset = ftello(f);
500 	if (offset == (off_t)-1) {
501 		set_suspended(1);
502 		logmsg(LOG_ERR, "Logging suspended: ftello: %s",
503 		    strerror(errno));
504 		return (1);
505 	}
506 
507 	if (fwrite(buffer, len, 1, f) != 1) {
508 		set_suspended(1);
509 		logmsg(LOG_ERR, "Logging suspended: fwrite: %s",
510 		    strerror(errno));
511 		ftruncate(fileno(f), offset);
512 		return (1);
513 	}
514 
515 	set_suspended(0);
516 	bufpos = buffer;
517 	bufleft = buflen;
518 	bufpkt = 0;
519 
520 	return (0);
521 }
522 
523 void
524 purge_buffer(void)
525 {
526 	packets_dropped += bufpkt;
527 
528 	set_suspended(0);
529 	bufpos = buffer;
530 	bufleft = buflen;
531 	bufpkt = 0;
532 }
533 
534 /* append packet to the buffer, flushing if necessary */
535 void
536 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
537 {
538 	FILE *f = (FILE *)user;
539 	struct pcap_sf_pkthdr sh;
540 	size_t len = sizeof(sh) + h->caplen;
541 
542 	if (len < sizeof(*h) || h->caplen > (size_t)cur_snaplen) {
543 		logmsg(LOG_NOTICE, "invalid size %zd (%u/%u), packet dropped",
544 		       len, cur_snaplen, snaplen);
545 		packets_dropped++;
546 		return;
547 	}
548 
549 	if (len <= bufleft)
550 		goto append;
551 
552 	if (suspended) {
553 		packets_dropped++;
554 		return;
555 	}
556 
557 	if (flush_buffer(f)) {
558 		packets_dropped++;
559 		return;
560 	}
561 
562 	if (len > bufleft) {
563 		dump_packet_nobuf(user, h, sp);
564 		return;
565 	}
566 
567  append:
568 	sh.ts.tv_sec = (bpf_int32)h->ts.tv_sec;
569 	sh.ts.tv_usec = (bpf_int32)h->ts.tv_usec;
570 	sh.caplen = h->caplen;
571 	sh.len = h->len;
572 
573 	memcpy(bufpos, &sh, sizeof(sh));
574 	memcpy(bufpos + sizeof(sh), sp, h->caplen);
575 
576 	bufpos += len;
577 	bufleft -= len;
578 	bufpkt++;
579 
580 	return;
581 }
582 
583 void
584 log_pcap_stats(void)
585 {
586 	struct pcap_stat pstat;
587 	if (pcap_stats(hpcap, &pstat) < 0)
588 		logmsg(LOG_WARNING, "Reading stats: %s", pcap_geterr(hpcap));
589 	else
590 		logmsg(LOG_NOTICE,
591                "%u packets received, %u/%ld dropped (kernel/pflogd)",
592                pstat.ps_recv, pstat.ps_drop, packets_dropped);
593 }
594 
595 int
596 main(int argc, char **argv)
597 {
598 	int ch, np, ret, Xflag = 0;
599 	pcap_handler phandler = dump_packet;
600 	const char *errstr = NULL;
601 	struct pidfh *pfh = NULL;
602 	char *pidf = NULL;
603 
604 	ret = 0;
605 
606 	/* Neither FreeBSD nor DFly have this; Max seems to think this may
607 	 * be a paranoid check. Comment it out:
608 	closefrom(STDERR_FILENO + 1);
609 	 */
610 
611 	while ((ch = getopt(argc, argv, "Dxd:f:i:p:s:")) != -1) {
612 		switch (ch) {
613 		case 'D':
614 			Debug = 1;
615 			break;
616 		case 'd':
617 			delay = strtonum(optarg, 5, 60*60, &errstr);
618 			if (errstr)
619 				usage();
620 			break;
621 		case 'f':
622 			filename = optarg;
623 			break;
624 		case 'i':
625 			interface = optarg;
626 			break;
627 		case 'p':
628 			pidf = optarg;
629 			break;
630 		case 's':
631 			snaplen = strtonum(optarg, 0, PFLOGD_MAXSNAPLEN,
632 			    &errstr);
633 			if (snaplen <= 0)
634 				snaplen = DEF_SNAPLEN;
635 			if (errstr)
636 				snaplen = PFLOGD_MAXSNAPLEN;
637 			break;
638 		case 'x':
639 			Xflag++;
640 			break;
641 		default:
642 			usage();
643 		}
644 
645 	}
646 
647 	log_debug = Debug;
648 	argc -= optind;
649 	argv += optind;
650 
651 	/* does interface exist */
652 	if (!if_exists(__DECONST(char *, interface))) {
653 		warn("Failed to initialize: %s", interface);
654 		logmsg(LOG_ERR, "Failed to initialize: %s", interface);
655 		logmsg(LOG_ERR, "Exiting, init failure");
656 		exit(1);
657 	}
658 
659 	if (!Debug) {
660 		openlog("pflogd", LOG_PID | LOG_CONS, LOG_DAEMON);
661 		pfh = pidfile_open(pidf, 0600, NULL);
662 		if (daemon(0, 0)) {
663 			logmsg(LOG_WARNING, "Failed to become daemon: %s",
664 			    strerror(errno));
665 		}
666 		pidfile_write(pfh);
667 	}
668 
669 	tzset();
670 	umask(S_IRWXG | S_IRWXO);
671 
672 	/* filter will be used by the privileged process */
673 	if (argc) {
674 		filter = copy_argv(argv);
675 		if (filter == NULL)
676 			logmsg(LOG_NOTICE, "Failed to form filter expression");
677 	}
678 
679 	/* initialize pcap before dropping privileges */
680 	if (init_pcap()) {
681 		logmsg(LOG_ERR, "Exiting, init failure");
682 		exit(1);
683 	}
684 
685 	/* Privilege separation begins here */
686 	if (priv_init()) {
687 		logmsg(LOG_ERR, "unable to privsep");
688 		exit(1);
689 	}
690 
691 	setproctitle("[initializing]");
692 	/* Process is now unprivileged and inside a chroot */
693 	signal(SIGTERM, sig_close);
694 	signal(SIGINT, sig_close);
695 	signal(SIGQUIT, sig_close);
696 	signal(SIGALRM, sig_alrm);
697 	signal(SIGUSR1, sig_usr1);
698 	signal(SIGHUP, sig_hup);
699 	alarm(delay);
700 
701 	buffer = malloc(PFLOGD_BUFSIZE);
702 
703 	if (buffer == NULL) {
704 		logmsg(LOG_WARNING, "Failed to allocate output buffer");
705 		phandler = dump_packet_nobuf;
706 	} else {
707 		bufleft = buflen = PFLOGD_BUFSIZE;
708 		bufpos = buffer;
709 		bufpkt = 0;
710 	}
711 
712 	if (reset_dump(Xflag) < 0) {
713 		if (Xflag)
714 			return (1);
715 
716 		logmsg(LOG_ERR, "Logging suspended: open error");
717 		set_suspended(1);
718 	} else if (Xflag)
719 		return (0);
720 
721 	while (1) {
722 		np = pcap_dispatch(hpcap, PCAP_NUM_PKTS,
723 		    phandler, (u_char *)dpcap);
724 		if (np < 0) {
725 			if (!if_exists(__DECONST(char *, interface))) {
726 				logmsg(LOG_NOTICE, "interface %s went away",
727 				    interface);
728 				ret = -1;
729 				break;
730 			}
731 			logmsg(LOG_NOTICE, "%s", pcap_geterr(hpcap));
732 		}
733 
734 		if (gotsig_close)
735 			break;
736 		if (gotsig_hup) {
737 			if (reset_dump(0)) {
738 				logmsg(LOG_ERR,
739 				    "Logging suspended: open error");
740 				set_suspended(1);
741 			}
742 			gotsig_hup = 0;
743 		}
744 
745 		if (gotsig_alrm) {
746 			if (dpcap)
747 				flush_buffer(dpcap);
748 			else
749 				gotsig_hup = 1;
750 			gotsig_alrm = 0;
751 			alarm(delay);
752 		}
753 
754 		if (gotsig_usr1) {
755 			log_pcap_stats();
756 			gotsig_usr1 = 0;
757 		}
758 	}
759 
760 	logmsg(LOG_NOTICE, "Exiting");
761 	if (dpcap) {
762 		flush_buffer(dpcap);
763 		fclose(dpcap);
764 	}
765 	purge_buffer();
766 
767 	log_pcap_stats();
768 	pcap_close(hpcap);
769 	if (!Debug)
770 		closelog();
771 	return (ret);
772 }
773