xref: /netbsd-src/usr.bin/newsyslog/newsyslog.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: newsyslog.c,v 1.50 2007/12/15 19:44:52 perry Exp $	*/
2 
3 /*
4  * Copyright (c) 1999, 2000 Andrew Doran <ad@NetBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  */
29 
30 /*
31  * This file contains changes from the Open Software Foundation.
32  */
33 
34 /*
35  * Copyright 1988, 1989 by the Massachusetts Institute of Technology
36  *
37  * Permission to use, copy, modify, and distribute this software
38  * and its documentation for any purpose and without fee is
39  * hereby granted, provided that the above copyright notice
40  * appear in all copies and that both that copyright notice and
41  * this permission notice appear in supporting documentation,
42  * and that the names of M.I.T. and the M.I.T. S.I.P.B. not be
43  * used in advertising or publicity pertaining to distribution
44  * of the software without specific, written prior permission.
45  * M.I.T. and the M.I.T. S.I.P.B. make no representations about
46  * the suitability of this software for any purpose.  It is
47  * provided "as is" without express or implied warranty.
48  *
49  */
50 
51 /*
52  * newsyslog(8) - a program to roll over log files provided that specified
53  * critera are met, optionally preserving a number of historical log files.
54  */
55 
56 #include <sys/cdefs.h>
57 #ifndef lint
58 __RCSID("$NetBSD: newsyslog.c,v 1.50 2007/12/15 19:44:52 perry Exp $");
59 #endif /* not lint */
60 
61 #include <sys/types.h>
62 #include <sys/time.h>
63 #include <sys/stat.h>
64 #include <sys/param.h>
65 #include <sys/wait.h>
66 
67 #include <ctype.h>
68 #include <fcntl.h>
69 #include <grp.h>
70 #include <pwd.h>
71 #include <signal.h>
72 #include <stdio.h>
73 #include <stdlib.h>
74 #include <stdarg.h>
75 #include <string.h>
76 #include <time.h>
77 #include <unistd.h>
78 #include <errno.h>
79 #include <err.h>
80 #include <paths.h>
81 
82 #include "pathnames.h"
83 
84 #define	PRHDRINFO(x)	\
85     (/*LINTED*/(void)(verbose ? printf x : 0))
86 #define	PRINFO(x)	\
87     (/*LINTED*/(void)(verbose ? printf("  ") + printf x : 0))
88 
89 #define	CE_COMPRESS	0x01	/* Compress the archived log files */
90 #define	CE_BINARY	0x02	/* Logfile is a binary file/non-syslog */
91 #define	CE_NOSIGNAL	0x04	/* Don't send a signal when trimmed */
92 #define	CE_CREATE	0x08	/* Create log file if none exists */
93 #define	CE_PLAIN0	0x10	/* Do not compress zero'th history file */
94 
95 struct conf_entry {
96 	uid_t	uid;			/* Owner of log */
97 	gid_t	gid;			/* Group of log */
98 	mode_t	mode;			/* File permissions */
99 	int	numhist;		/* Number of historical logs to keep */
100 	size_t	maxsize;		/* Maximum log size */
101 	int	maxage;			/* Hours between log trimming */
102 	time_t	trimat;			/* Specific trim time */
103 	int	flags;			/* Flags (CE_*) */
104 	int	signum;			/* Signal to send */
105 	char	pidfile[MAXPATHLEN];	/* File containing PID to signal */
106 	char	logfile[MAXPATHLEN];	/* Path to log file */
107 };
108 
109 static int	verbose;			/* Be verbose */
110 static int	noaction;			/* Take no action */
111 static int	nosignal;			/* Do not send signals */
112 static char	hostname[MAXHOSTNAMELEN + 1];	/* Hostname, no domain */
113 static uid_t	myeuid;				/* EUID we are running with */
114 
115 static int	getsig(const char *);
116 static int	isnumber(const char *);
117 static int	parse_cfgline(struct conf_entry *, FILE *, size_t *);
118 static time_t	parse_iso8601(char *);
119 static time_t	parse_dwm(char *);
120 static int	parse_userspec(const char *, struct passwd **, struct group **);
121 static pid_t	readpidfile(const char *);
122 static void	usage(void) __dead;
123 
124 static void	log_compress(struct conf_entry *, const char *);
125 static void	log_create(struct conf_entry *);
126 static void	log_examine(struct conf_entry *, int);
127 static void	log_trim(struct conf_entry *);
128 static void	log_trimmed(struct conf_entry *);
129 
130 /*
131  * Program entry point.
132  */
133 int
134 main(int argc, char **argv)
135 {
136 	struct conf_entry log;
137 	FILE *fd;
138 	char *p;
139 	const char *cfile;
140 	int c, needroot, i, force;
141 	size_t lineno;
142 
143 	force = 0;
144 	needroot = 1;
145 	cfile = _PATH_NEWSYSLOGCONF;
146 
147 	(void)gethostname(hostname, sizeof(hostname));
148 	hostname[sizeof(hostname) - 1] = '\0';
149 
150 	/* Truncate domain. */
151 	if ((p = strchr(hostname, '.')) != NULL)
152 		*p = '\0';
153 
154 	/* Parse command line options. */
155 	while ((c = getopt(argc, argv, "f:nrsvF")) != -1) {
156 		switch (c) {
157 		case 'f':
158 			cfile = optarg;
159 			break;
160 		case 'n':
161 			noaction = 1;
162 			verbose = 1;
163 			break;
164 		case 'r':
165 			needroot = 0;
166 			break;
167 		case 's':
168 			nosignal = 1;
169 			break;
170 		case 'v':
171 			verbose = 1;
172 			break;
173 		case 'F':
174 			force = 1;
175 			break;
176 		default:
177 			usage();
178 			/* NOTREACHED */
179 		}
180 	}
181 
182 	myeuid = geteuid();
183 	if (needroot && myeuid != 0)
184 		errx(EXIT_FAILURE, "must be run as root");
185 
186 	argc -= optind;
187 	argv += optind;
188 
189 	if (strcmp(cfile, "-") == 0)
190 		fd = stdin;
191 	else if ((fd = fopen(cfile, "rt")) == NULL)
192 		err(EXIT_FAILURE, "%s", cfile);
193 
194 	for (lineno = 0; !parse_cfgline(&log, fd, &lineno);) {
195 		/*
196 		 * If specific log files were specified, touch only
197 		 * those.
198 		 */
199 		if (argc != 0) {
200 			for (i = 0; i < argc; i++)
201 				if (strcmp(log.logfile, argv[i]) == 0)
202 					break;
203 			if (i == argc)
204 				continue;
205 		}
206 		log_examine(&log, force);
207 	}
208 
209 	if (fd != stdin)
210 		(void)fclose(fd);
211 
212 	exit(EXIT_SUCCESS);
213 	/* NOTREACHED */
214 }
215 
216 /*
217  * Parse a single line from the configuration file.
218  */
219 static int
220 parse_cfgline(struct conf_entry *log, FILE *fd, size_t *_lineno)
221 {
222 	char *line, *q, **ap, *argv[10];
223 	struct passwd *pw;
224 	struct group *gr;
225 	int nf, lineno, i, rv;
226 
227 	rv = -1;
228 	line = NULL;
229 
230 	/* Place the white-space separated fields into an array. */
231 	do {
232 		if (line != NULL)
233 			free(line);
234 		if ((line = fparseln(fd, NULL, _lineno, NULL, 0)) == NULL)
235 			return (rv);
236 		lineno = (int)*_lineno;
237 
238 		for (ap = argv, nf = 0; (*ap = strsep(&line, " \t")) != NULL;)
239 			if (**ap != '\0') {
240 				if (++nf == sizeof(argv) / sizeof(argv[0])) {
241 					warnx("config line %d: "
242 					    "too many fields", lineno);
243 					goto bad;
244 				}
245 				ap++;
246 			}
247 	} while (nf == 0);
248 
249 	if (nf < 6)
250 		errx(EXIT_FAILURE, "config line %d: too few fields", lineno);
251 
252 	(void)memset(log, 0, sizeof(*log));
253 
254 	/* logfile_name */
255 	ap = argv;
256 	(void)strlcpy(log->logfile, *ap++, sizeof(log->logfile));
257 	if (log->logfile[0] != '/')
258 		errx(EXIT_FAILURE,
259 		    "config line %d: logfile must have a full path", lineno);
260 
261 	/* owner:group */
262 	if (strchr(*ap, ':') != NULL || strchr(*ap, '.') != NULL) {
263 		if (parse_userspec(*ap++, &pw, &gr)) {
264 			warnx("config line %d: unknown user/group", lineno);
265 			goto bad;
266 		}
267 
268 		/*
269 		 * We may only change the file's owner as non-root.
270 		 */
271 		if (myeuid != 0) {
272 			if (pw->pw_uid != myeuid)
273 				errx(EXIT_FAILURE, "config line %d: user:group "
274 				    "as non-root must match current user",
275 				    lineno);
276 			log->uid = (uid_t)-1;
277 		} else
278 			log->uid = pw->pw_uid;
279 		log->gid = gr->gr_gid;
280 		if (nf < 7)
281 			errx(EXIT_FAILURE, "config line %d: too few fields",
282 			    lineno);
283 	} else if (myeuid != 0) {
284 		log->uid = (uid_t)-1;
285 		log->gid = getegid();
286 	}
287 
288 	/* mode */
289 	if (sscanf(*ap++, "%o", &i) != 1) {
290 		warnx("config line %d: bad permissions", lineno);
291 		goto bad;
292 	}
293 	log->mode = (mode_t)i;
294 
295 	/* count */
296 	if (sscanf(*ap++, "%d", &log->numhist) != 1) {
297 		warnx("config line %d: bad log count", lineno);
298 		goto bad;
299 	}
300 
301 	/* size */
302 	if (**ap == '*')
303 		log->maxsize = (size_t)-1;
304 	else {
305 		log->maxsize = (int)strtol(*ap, &q, 0);
306 		if (*q != '\0') {
307 			warnx("config line %d: bad log size", lineno);
308 			goto bad;
309 		}
310 	}
311 	ap++;
312 
313 	/* when */
314 	log->maxage = -1;
315 	log->trimat = (time_t)-1;
316 	q = *ap++;
317 
318 	if (strcmp(q, "*") != 0) {
319 		if (isdigit((unsigned char)*q))
320 			log->maxage = (int)strtol(q, &q, 10);
321 
322 		/*
323 		 * One class of periodic interval specification can follow a
324 		 * maximum age specification.  Handle it.
325 		 */
326 		if (*q == '@') {
327 			log->trimat = parse_iso8601(q + 1);
328 			if (log->trimat == (time_t)-1) {
329 				warnx("config line %d: bad trim time", lineno);
330 				goto bad;
331 			}
332 		} else if (*q == '$') {
333 			if ((log->trimat = parse_dwm(q + 1)) == (time_t)-1) {
334 				warnx("config line %d: bad trim time", lineno);
335 				goto bad;
336 			}
337 		} else if (log->maxage == -1) {
338 			warnx("config line %d: bad log age", lineno);
339 			goto bad;
340 		}
341 	}
342 
343 	/* flags */
344 	log->flags = (nosignal ? CE_NOSIGNAL : 0);
345 
346 	for (q = *ap++; q != NULL && *q != '\0'; q++) {
347 		switch (tolower((unsigned char)*q)) {
348 		case 'b':
349 			log->flags |= CE_BINARY;
350 			break;
351 		case 'c':
352 			log->flags |= CE_CREATE;
353 			break;
354 		case 'n':
355 			log->flags |= CE_NOSIGNAL;
356 			break;
357 		case 'p':
358 			log->flags |= CE_PLAIN0;
359 			break;
360 		case 'z':
361 			log->flags |= CE_COMPRESS;
362 			break;
363 		case '-':
364 			break;
365 		default:
366 			warnx("config line %d: bad flags", lineno);
367 			goto bad;
368 		}
369 	}
370 
371 	/* path_to_pidfile */
372 	if (*ap != NULL && **ap == '/')
373 		(void)strlcpy(log->pidfile, *ap++, sizeof(log->pidfile));
374 	else
375 		log->pidfile[0] = '\0';
376 
377 	/* sigtype */
378 	if (*ap != NULL) {
379 		if ((log->signum = getsig(*ap++)) < 0) {
380 			warnx("config line %d: bad signal type", lineno);
381 			goto bad;
382 		}
383 	} else
384 		log->signum = SIGHUP;
385 
386 	rv = 0;
387 
388 bad:
389 	free(line);
390 	return (rv);
391 }
392 
393 /*
394  * Examine a log file.  If the trim conditions are met, call log_trim() to
395  * trim the log file.
396  */
397 static void
398 log_examine(struct conf_entry *log, int force)
399 {
400 	struct stat sb;
401 	size_t size;
402 	int age, trim;
403 	char tmp[MAXPATHLEN];
404 	const char *reason;
405 	time_t now;
406 
407 	now = time(NULL);
408 
409 	PRHDRINFO(("\n%s <%d%s>: ", log->logfile, log->numhist,
410 	    (log->flags & CE_COMPRESS) != 0 ? "Z" : ""));
411 
412 	/*
413 	 * stat() the logfile.  If it doesn't exist and the `c' flag has
414 	 * been specified, create it.  If it doesn't exist and the `c' flag
415 	 * hasn't been specified, give up.
416 	 */
417 	if (stat(log->logfile, &sb) < 0) {
418 		if (errno == ENOENT && (log->flags & CE_CREATE) != 0) {
419 			PRHDRINFO(("creating; "));
420 			if (!noaction)
421 				log_create(log);
422 			else {
423 				PRHDRINFO(("can't proceed with `-n'\n"));
424 				return;
425 			}
426 			if (stat(log->logfile, &sb))
427 				err(EXIT_FAILURE, "%s", log->logfile);
428 		} else if (errno == ENOENT) {
429 			PRHDRINFO(("does not exist --> skip log\n"));
430 			return;
431 		} else if (errno != 0)
432 			err(EXIT_FAILURE, "%s", log->logfile);
433 	}
434 
435 	if (!S_ISREG(sb.st_mode)) {
436 		PRHDRINFO(("not a regular file --> skip log\n"));
437 		return;
438 	}
439 
440 	/* Size of the log file in kB. */
441 	size = ((size_t)sb.st_blocks * S_BLKSIZE) >> 10;
442 
443 	/*
444 	 * Get the age (expressed in hours) of the current log file with
445 	 * respect to the newest historical log file.
446 	 */
447 	(void)strlcpy(tmp, log->logfile, sizeof(tmp));
448 	(void)strlcat(tmp, ".0", sizeof(tmp));
449 	if (stat(tmp, &sb) < 0) {
450 		(void)strlcat(tmp, ".gz", sizeof(tmp));
451 		if (stat(tmp, &sb) < 0)
452 			age = -1;
453 		else
454 			age = (int)(now - sb.st_mtime + 1800) / 3600;
455 	} else
456 		age = (int)(now - sb.st_mtime + 1800) / 3600;
457 
458 	/*
459 	 * Examine the set of given trim conditions and if any one is met,
460 	 * trim the log.
461 	 *
462 	 * Note: if `maxage' or `trimat' is used as a trim condition, we
463 	 * need at least one historical log file to determine the `age' of
464 	 * the active log file.  WRT `trimat', we will trim up to one hour
465 	 * after the specific trim time has passed - we need to know if
466 	 * we've trimmed to meet that condition with a previous invocation
467 	 * of newsyslog(8).
468 	 */
469 	if (log->maxage >= 0 && (age >= log->maxage || age < 0)) {
470 		trim = 1;
471 		reason = "log age > interval";
472 	} else if (size >= log->maxsize) {
473 		trim = 1;
474 		reason = "log size > size";
475 	} else if (log->trimat != (time_t)-1 && now >= log->trimat &&
476 		   (age == -1 || age > 1) &&
477 		   difftime(now, log->trimat) < 60 * 60) {
478 		trim = 1;
479 		reason = "specific trim time";
480 	} else {
481 		trim = force;
482 		reason = "trim forced";
483 	}
484 
485 	if (trim) {
486 		PRHDRINFO(("--> trim log (%s)\n", reason));
487 		log_trim(log);
488 	} else
489 		PRHDRINFO(("--> skip log (trim conditions not met)\n"));
490 }
491 
492 /*
493  * Trim the specified log file.
494  */
495 static void
496 log_trim(struct conf_entry *log)
497 {
498 	char file1[MAXPATHLEN], file2[MAXPATHLEN];
499 	int i;
500 	struct stat st;
501 	pid_t pid;
502 
503 	if (log->numhist != 0) {
504 		/* Remove oldest historical log. */
505 		(void)snprintf(file1, sizeof(file1), "%s.%d", log->logfile,
506 		    log->numhist - 1);
507 
508 		PRINFO(("rm -f %s\n", file1));
509 		if (!noaction)
510 			(void)unlink(file1);
511 		(void)strlcat(file1, ".gz", sizeof(file1));
512 		PRINFO(("rm -f %s\n", file1));
513 		if (!noaction)
514 			(void)unlink(file1);
515 	}
516 
517 	/* Move down log files. */
518 	for (i = log->numhist - 1; i > 0; i--) {
519 		snprintf(file1, sizeof(file1), "%s.%d", log->logfile, i - 1);
520 		snprintf(file2, sizeof(file2), "%s.%d", log->logfile, i);
521 
522 		if (lstat(file1, &st) != 0) {
523 			(void)strlcat(file1, ".gz", sizeof(file1));
524 			(void)strlcat(file2, ".gz", sizeof(file2));
525 			if (lstat(file1, &st) != 0)
526 				continue;
527 		}
528 
529 		PRINFO(("mv %s %s\n", file1, file2));
530 		if (!noaction)
531 			if (rename(file1, file2))
532 				err(EXIT_FAILURE, "%s", file1);
533 		PRINFO(("chmod %o %s\n", log->mode, file2));
534 		if (!noaction)
535 			if (chmod(file2, log->mode))
536 				err(EXIT_FAILURE, "%s", file2);
537 		PRINFO(("chown %d:%d %s\n", log->uid, log->gid,
538 		    file2));
539 		if (!noaction)
540 			if (chown(file2, log->uid, log->gid))
541 				err(EXIT_FAILURE, "%s", file2);
542 	}
543 
544 	/*
545 	 * If a historical log file isn't compressed, and 'z' has been
546 	 * specified, compress it.  (This is convenient, but is also needed
547 	 * if 'p' has been specified.)  It should be noted that gzip(1)
548 	 * preserves file ownership and file mode.
549 	 */
550 	if ((log->flags & CE_COMPRESS) != 0) {
551 		for (i = (log->flags & CE_PLAIN0) != 0; i < log->numhist; i++) {
552 			snprintf(file1, sizeof(file1), "%s.%d", log->logfile, i);
553 			if (lstat(file1, &st) != 0)
554 				continue;
555 			snprintf(file2, sizeof(file2), "%s.gz", file1);
556 			if (lstat(file2, &st) == 0)
557 				continue;
558 			log_compress(log, file1);
559 		}
560 	}
561 
562 	log_trimmed(log);
563 
564 	/* Create the historical log file if we're maintaining history. */
565 	if (log->numhist == 0) {
566 		PRINFO(("rm -f %s\n", log->logfile));
567 		if (!noaction)
568 			if (unlink(log->logfile))
569 				err(EXIT_FAILURE, "%s", log->logfile);
570 	} else {
571 		(void)snprintf(file1, sizeof(file1), "%s.0", log->logfile);
572 		PRINFO(("mv %s %s\n", log->logfile, file1));
573 		if (!noaction)
574 			if (rename(log->logfile, file1))
575 				err(EXIT_FAILURE, "%s", log->logfile);
576 	}
577 
578 	PRINFO(("(create new log)\n"));
579 	log_create(log);
580 	log_trimmed(log);
581 
582 	/* Set the correct permissions on the log. */
583 	PRINFO(("chmod %o %s\n", log->mode, log->logfile));
584 	if (!noaction)
585 		if (chmod(log->logfile, log->mode))
586 			err(EXIT_FAILURE, "%s", log->logfile);
587 
588 	/* Do we need to signal a daemon? */
589 	if ((log->flags & CE_NOSIGNAL) == 0) {
590 		if (log->pidfile[0] != '\0')
591 			pid = readpidfile(log->pidfile);
592 		else
593 			pid = readpidfile(_PATH_SYSLOGDPID);
594 
595 		if (pid != (pid_t)-1) {
596 			PRINFO(("kill -%s %lu\n",
597 			    sys_signame[log->signum], (u_long)pid));
598 			if (!noaction)
599 				if (kill(pid, log->signum))
600 					warn("kill");
601 		}
602 	}
603 
604 	/* If the newest historical log is to be compressed, do it here. */
605 	if ((log->flags & (CE_PLAIN0 | CE_COMPRESS)) == CE_COMPRESS
606 	    && log->numhist != 0) {
607 		snprintf(file1, sizeof(file1), "%s.0", log->logfile);
608 		if ((log->flags & CE_NOSIGNAL) == 0) {
609 			PRINFO(("sleep for 10 seconds before compressing...\n"));
610 			(void)sleep(10);
611 		}
612 		log_compress(log, file1);
613 	}
614 }
615 
616 /*
617  * Write an entry to the log file recording the fact that it was trimmed.
618  */
619 static void
620 log_trimmed(struct conf_entry *log)
621 {
622 	FILE *fd;
623 	time_t now;
624 	char *daytime;
625 
626 	if ((log->flags & CE_BINARY) != 0)
627 		return;
628 	PRINFO(("(append rotation notice to %s)\n", log->logfile));
629 	if (noaction)
630 		return;
631 
632 	if ((fd = fopen(log->logfile, "at")) == NULL)
633 		err(EXIT_FAILURE, "%s", log->logfile);
634 
635 	now = time(NULL);
636 	daytime = ctime(&now) + 4;
637 	daytime[15] = '\0';
638 
639 	(void)fprintf(fd, "%s %s newsyslog[%lu]: log file turned over\n",
640 	    daytime, hostname, (u_long)getpid());
641 	(void)fclose(fd);
642 }
643 
644 /*
645  * Create a new log file.
646  */
647 static void
648 log_create(struct conf_entry *log)
649 {
650 	int fd;
651 
652 	if (noaction)
653 		return;
654 
655 	if ((fd = creat(log->logfile, log->mode)) < 0)
656 		err(EXIT_FAILURE, "%s", log->logfile);
657 	if (fchown(fd, log->uid, log->gid) < 0)
658 		err(EXIT_FAILURE, "%s", log->logfile);
659 	(void)close(fd);
660 }
661 
662 /*
663  * Fork off gzip(1) to compress a log file.  This routine takes an
664  * additional string argument (the name of the file to compress): it is also
665  * used to compress historical log files other than the newest.
666  */
667 static void
668 log_compress(struct conf_entry *log, const char *fn)
669 {
670 	char tmp[MAXPATHLEN];
671 
672 	PRINFO(("gzip %s\n", fn));
673 	if (!noaction) {
674 		pid_t pid;
675 		int status;
676 
677 		if ((pid = vfork()) < 0)
678 			err(EXIT_FAILURE, "vfork");
679 		else if (pid == 0) {
680 			(void)execl(_PATH_GZIP, "gzip", "-f", fn, NULL);
681 			_exit(EXIT_FAILURE);
682 		}
683 		while (waitpid(pid, &status, 0) != pid);
684 
685 		if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
686 			errx(EXIT_FAILURE, "gzip failed");
687 	}
688 
689 	(void)snprintf(tmp, sizeof(tmp), "%s.gz", fn);
690 	PRINFO(("chown %d:%d %s\n", log->uid, log->gid, tmp));
691 	if (!noaction)
692 		if (chown(tmp, log->uid, log->gid))
693 			err(EXIT_FAILURE, "%s", tmp);
694 }
695 
696 /*
697  * Display program usage information.
698  */
699 static void
700 usage(void)
701 {
702 
703 	(void)fprintf(stderr,
704 	    "Usage: %s [-nrsvF] [-f config-file] [file ...]\n", getprogname());
705 	exit(EXIT_FAILURE);
706 }
707 
708 /*
709  * Return non-zero if a string represents a decimal value.
710  */
711 static int
712 isnumber(const char *string)
713 {
714 
715 	while (isdigit((unsigned char)*string))
716 		string++;
717 
718 	return *string == '\0';
719 }
720 
721 /*
722  * Given a signal name, attempt to find the corresponding signal number.
723  */
724 static int
725 getsig(const char *sig)
726 {
727 	char *p;
728 	int n;
729 
730 	if (isnumber(sig)) {
731 		n = (int)strtol(sig, &p, 0);
732 		if (p != '\0' || n < 0 || n >= NSIG)
733 			return -1;
734 		return n;
735 	}
736 
737 	if (strncasecmp(sig, "SIG", 3) == 0)
738 		sig += 3;
739 	for (n = 1; n < NSIG; n++)
740 		if (strcasecmp(sys_signame[n], sig) == 0)
741 			return n;
742 	return -1;
743 }
744 
745 /*
746  * Given a path to a PID file, return the PID contained within.
747  */
748 static pid_t
749 readpidfile(const char *file)
750 {
751 	FILE *fd;
752 	char line[BUFSIZ];
753 	pid_t pid;
754 
755 #ifdef notyet
756 	if (file[0] != '/')
757 		(void)snprintf(tmp, sizeof(tmp), "%s%s", _PATH_VARRUN, file);
758 	else
759 		(void)strlcpy(tmp, file, sizeof(tmp));
760 #endif
761 
762 	if ((fd = fopen(file, "r")) == NULL) {
763 		warn("%s", file);
764 		return (pid_t)-1;
765 	}
766 
767 	if (fgets(line, sizeof(line) - 1, fd) != NULL) {
768 		line[sizeof(line) - 1] = '\0';
769 		pid = (pid_t)strtol(line, NULL, 0);
770 	} else {
771 		warnx("unable to read %s", file);
772 		pid = (pid_t)-1;
773 	}
774 
775 	(void)fclose(fd);
776 	return pid;
777 }
778 
779 /*
780  * Parse a user:group specification.
781  *
782  * XXX This is over the top for newsyslog(8).  It should be moved to libutil.
783  */
784 int
785 parse_userspec(const char *name, struct passwd **pw, struct group **gr)
786 {
787 	char buf[MAXLOGNAME * 2 + 2], *group;
788 
789 	(void)strlcpy(buf, name, sizeof(buf));
790 	*gr = NULL;
791 
792 	/*
793 	 * Before attempting to use '.' as a separator, see if the whole
794 	 * string resolves as a user name.
795 	 */
796 	if ((*pw = getpwnam(buf)) != NULL) {
797 		*gr = getgrgid((*pw)->pw_gid);
798 		return (0);
799 	}
800 
801 	/* Split the user and group name. */
802 	if ((group = strchr(buf, ':')) != NULL ||
803 	    (group = strchr(buf, '.')) != NULL)
804 		*group++ = '\0';
805 
806 	if (isnumber(buf))
807 		*pw = getpwuid((uid_t)atoi(buf));
808 	else
809 		*pw = getpwnam(buf);
810 
811 	/*
812 	 * Find the group.  If a group wasn't specified, use the user's
813 	 * `natural' group.  We get to this point even if no user was found.
814 	 * This is to allow the caller to get a better idea of what went
815 	 * wrong, if anything.
816 	 */
817 	if (group == NULL || *group == '\0') {
818 		if (*pw == NULL)
819 			return -1;
820 		*gr = getgrgid((*pw)->pw_gid);
821 	} else if (isnumber(group))
822 		*gr = getgrgid((gid_t)atoi(group));
823 	else
824 		*gr = getgrnam(group);
825 
826 	return *pw != NULL && *gr != NULL ? 0 : -1;
827 }
828 
829 /*
830  * Parse a cyclic time specification, the format is as follows:
831  *
832  *	[Dhh] or [Wd[Dhh]] or [Mdd[Dhh]]
833  *
834  * to rotate a log file cyclic at
835  *
836  *	- every day (D) within a specific hour (hh)	(hh = 0...23)
837  *	- once a week (W) at a specific day (d)     OR	(d = 0..6, 0 = Sunday)
838  *	- once a month (M) at a specific day (d)	(d = 1..31,l|L)
839  *
840  * We don't accept a timezone specification; missing fields are defaulted to
841  * the current date but time zero.
842  */
843 static time_t
844 parse_dwm(char *s)
845 {
846 	char *t;
847 	struct tm tm, *tmp;
848 	u_long ul;
849 	time_t now;
850 	static int mtab[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
851 	int wmseen, dseen, nd, save;
852 
853 	wmseen = 0;
854 	dseen = 0;
855 
856 	now = time(NULL);
857 	tmp = localtime(&now);
858 	tm = *tmp;
859 
860 	/* Set no. of days per month */
861 	nd = mtab[tm.tm_mon];
862 
863 	if (tm.tm_mon == 1 &&
864 	    ((tm.tm_year + 1900) % 4 == 0) &&
865 	    ((tm.tm_year + 1900) % 100 != 0) &&
866 	    ((tm.tm_year + 1900) % 400 == 0))
867 		nd++;	/* leap year, 29 days in february */
868 	tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
869 
870 	for (;;) {
871 		switch (*s) {
872 		case 'D':
873 			if (dseen)
874 				return (time_t)-1;
875 			dseen++;
876 			s++;
877 			ul = strtoul(s, &t, 10);
878 			if (ul > 23)
879 				return (time_t)-1;
880 			tm.tm_hour = ul;
881 			break;
882 
883 		case 'W':
884 			if (wmseen)
885 				return (time_t)-1;
886 			wmseen++;
887 			s++;
888 			ul = strtoul(s, &t, 10);
889 			if (ul > 6)
890 				return (-1);
891 			if (ul != tm.tm_wday) {
892 				if (ul < tm.tm_wday) {
893 					save = 6 - tm.tm_wday;
894 					save += (ul + 1);
895 				} else
896 					save = ul - tm.tm_wday;
897 				tm.tm_mday += save;
898 
899 				if (tm.tm_mday > nd) {
900 					tm.tm_mon++;
901 					tm.tm_mday = tm.tm_mday - nd;
902 				}
903 			}
904 			break;
905 
906 		case 'M':
907 			if (wmseen)
908 				return (time_t)-1;
909 			wmseen++;
910 			s++;
911 			if (tolower((unsigned char)*s) == 'l') {
912 				tm.tm_mday = nd;
913 				s++;
914 				t = s;
915 			} else {
916 				ul = strtoul(s, &t, 10);
917 				if (ul < 1 || ul > 31)
918 					return (time_t)-1;
919 
920 				if (ul > nd)
921 					return (time_t)-1;
922 				tm.tm_mday = ul;
923 			}
924 			break;
925 
926 		default:
927 			return (time_t)-1;
928 		}
929 
930 		if (*t == '\0' || isspace((unsigned char)*t))
931 			break;
932 		else
933 			s = t;
934 	}
935 
936 	return mktime(&tm);
937 }
938 
939 /*
940  * Parse a limited subset of ISO 8601.  The specific format is as follows:
941  *
942  * [CC[YY[MM[DD]]]][THH[MM[SS]]]	(where `T' is the literal letter)
943  *
944  * We don't accept a timezone specification; missing fields (including
945  * timezone) are defaulted to the current date but time zero.
946  */
947 static time_t
948 parse_iso8601(char *s)
949 {
950 	char *t;
951 	struct tm tm, *tmp;
952 	u_long ul;
953 	time_t now;
954 
955 	now = time(NULL);
956 	tmp = localtime(&now);
957 	tm = *tmp;
958 
959 	tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
960 
961 	ul = strtoul(s, &t, 10);
962 	if (*t != '\0' && *t != 'T')
963 		return (time_t)-1;
964 
965 	/*
966 	 * Now t points either to the end of the string (if no time was
967 	 * provided) or to the letter `T' which separates date and time in
968 	 * ISO 8601.  The pointer arithmetic is the same for either case.
969 	 */
970 	switch (t - s) {
971 	case 8:
972 		tm.tm_year = ((ul / 1000000) - 19) * 100;
973 		ul = ul % 1000000;
974 		/* FALLTHROUGH */
975 	case 6:
976 		tm.tm_year = tm.tm_year - (tm.tm_year % 100);
977 		tm.tm_year += ul / 10000;
978 		ul = ul % 10000;
979 		/* FALLTHROUGH */
980 	case 4:
981 		tm.tm_mon = (ul / 100) - 1;
982 		ul = ul % 100;
983 		/* FALLTHROUGH */
984 	case 2:
985 		tm.tm_mday = ul;
986 		/* FALLTHROUGH */
987 	case 0:
988 		break;
989 	default:
990 		return (time_t)-1;
991 	}
992 
993 	/* Sanity check */
994 	if (tm.tm_year < 70 || tm.tm_mon < 0 || tm.tm_mon > 12 ||
995 	    tm.tm_mday < 1 || tm.tm_mday > 31)
996 		return (time_t)-1;
997 
998 	if (*t != '\0') {
999 		s = ++t;
1000 		ul = strtoul(s, &t, 10);
1001 		if (*t != '\0' && !isspace((unsigned char)*t))
1002 			return (time_t)-1;
1003 
1004 		switch (t - s) {
1005 		case 6:
1006 			tm.tm_sec = ul % 100;
1007 			ul /= 100;
1008 			/* FALLTHROUGH */
1009 		case 4:
1010 			tm.tm_min = ul % 100;
1011 			ul /= 100;
1012 			/* FALLTHROUGH */
1013 		case 2:
1014 			tm.tm_hour = ul;
1015 			/* FALLTHROUGH */
1016 		case 0:
1017 			break;
1018 		default:
1019 			return (time_t)-1;
1020 		}
1021 
1022 		/* Sanity check */
1023 		if (tm.tm_sec < 0 || tm.tm_sec > 60 || tm.tm_min < 0 ||
1024 		    tm.tm_min > 59 || tm.tm_hour < 0 || tm.tm_hour > 23)
1025 			return (time_t)-1;
1026 	}
1027 
1028 	return mktime(&tm);
1029 }
1030