xref: /openbsd-src/usr.sbin/syslogd/syslogd.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: syslogd.c,v 1.43 2001/08/03 20:24:16 millert Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1988, 1993, 1994
5  *	The Regents of the University of California.  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  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef lint
37 static char copyright[] =
38 "@(#) Copyright (c) 1983, 1988, 1993, 1994\n\
39 	The Regents of the University of California.  All rights reserved.\n";
40 #endif /* not lint */
41 
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)syslogd.c	8.3 (Berkeley) 4/4/94";
45 #else
46 static char rcsid[] = "$OpenBSD: syslogd.c,v 1.43 2001/08/03 20:24:16 millert Exp $";
47 #endif
48 #endif /* not lint */
49 
50 /*
51  *  syslogd -- log system messages
52  *
53  * This program implements a system log. It takes a series of lines.
54  * Each line may have a priority, signified as "<n>" as
55  * the first characters of the line.  If this is
56  * not present, a default priority is used.
57  *
58  * To kill syslogd, send a signal 15 (terminate).  A signal 1 (hup) will
59  * cause it to reread its configuration file.
60  *
61  * Defined Constants:
62  *
63  * MAXLINE -- the maximimum line length that can be handled.
64  * DEFUPRI -- the default priority for user messages
65  * DEFSPRI -- the default priority for kernel messages
66  *
67  * Author: Eric Allman
68  * extensive changes by Ralph Campbell
69  * more extensive changes by Eric Allman (again)
70  */
71 
72 #define	MAXLINE		1024		/* maximum line length */
73 #define	MAXSVLINE	120		/* maximum saved line length */
74 #define DEFUPRI		(LOG_USER|LOG_NOTICE)
75 #define DEFSPRI		(LOG_KERN|LOG_CRIT)
76 #define TIMERINTVL	30		/* interval for checking flush, mark */
77 #define TTYMSGTIME	1		/* timeout passed to ttymsg */
78 
79 #include <sys/param.h>
80 #include <sys/ioctl.h>
81 #include <sys/stat.h>
82 #include <sys/wait.h>
83 #include <sys/socket.h>
84 #include <sys/msgbuf.h>
85 #include <sys/uio.h>
86 #include <sys/sysctl.h>
87 #include <sys/un.h>
88 #include <sys/time.h>
89 #include <sys/resource.h>
90 
91 #include <netinet/in.h>
92 #include <netdb.h>
93 #include <arpa/inet.h>
94 
95 #include <ctype.h>
96 #include <errno.h>
97 #include <err.h>
98 #include <fcntl.h>
99 #include <paths.h>
100 #include <setjmp.h>
101 #include <signal.h>
102 #include <stdio.h>
103 #include <stdlib.h>
104 #include <string.h>
105 #include <unistd.h>
106 #include <utmp.h>
107 #include <vis.h>
108 
109 #define SYSLOG_NAMES
110 #include <sys/syslog.h>
111 
112 char	*ConfFile = _PATH_LOGCONF;
113 char	*PidFile = _PATH_LOGPID;
114 char	ctty[] = _PATH_CONSOLE;
115 
116 #define	dprintf		if (Debug) printf
117 
118 #define MAXUNAMES	20	/* maximum number of user names */
119 
120 /*
121  * Flags to logmsg().
122  */
123 
124 #define IGN_CONS	0x001	/* don't print on console */
125 #define SYNC_FILE	0x002	/* do fsync on file after printing */
126 #define ADDDATE		0x004	/* add a date to the message */
127 #define MARK		0x008	/* this message is a mark */
128 
129 /*
130  * This structure represents the files that will have log
131  * copies printed.
132  */
133 
134 struct filed {
135 	struct	filed *f_next;		/* next in linked list */
136 	short	f_type;			/* entry type, see below */
137 	short	f_file;			/* file descriptor */
138 	time_t	f_time;			/* time this was last written */
139 	u_char	f_pmask[LOG_NFACILITIES+1];	/* priority mask */
140 	char	*f_program;		/* program this applies to */
141 	union {
142 		char	f_uname[MAXUNAMES][UT_NAMESIZE+1];
143 		struct {
144 			char	f_hname[MAXHOSTNAMELEN];
145 			struct sockaddr_in	f_addr;
146 		} f_forw;		/* forwarding address */
147 		char	f_fname[MAXPATHLEN];
148 	} f_un;
149 	char	f_prevline[MAXSVLINE];		/* last message logged */
150 	char	f_lasttime[16];			/* time of last occurrence */
151 	char	f_prevhost[MAXHOSTNAMELEN];	/* host from which recd. */
152 	int	f_prevpri;			/* pri of f_prevline */
153 	int	f_prevlen;			/* length of f_prevline */
154 	int	f_prevcount;			/* repetition cnt of prevline */
155 	int	f_repeatcount;			/* number of "repeated" msgs */
156 };
157 
158 /*
159  * Intervals at which we flush out "message repeated" messages,
160  * in seconds after previous message is logged.  After each flush,
161  * we move to the next interval until we reach the largest.
162  */
163 int	repeatinterval[] = { 30, 120, 600 };	/* # of secs before flush */
164 #define	MAXREPEAT ((sizeof(repeatinterval) / sizeof(repeatinterval[0])) - 1)
165 #define	REPEATTIME(f)	((f)->f_time + repeatinterval[(f)->f_repeatcount])
166 #define	BACKOFF(f)	{ if (++(f)->f_repeatcount > MAXREPEAT) \
167 				 (f)->f_repeatcount = MAXREPEAT; \
168 			}
169 
170 /* values for f_type */
171 #define F_UNUSED	0		/* unused entry */
172 #define F_FILE		1		/* regular file */
173 #define F_TTY		2		/* terminal */
174 #define F_CONSOLE	3		/* console terminal */
175 #define F_FORW		4		/* remote machine */
176 #define F_USERS		5		/* list of users */
177 #define F_WALL		6		/* everyone logged on */
178 
179 char	*TypeNames[7] = {
180 	"UNUSED",	"FILE",		"TTY",		"CONSOLE",
181 	"FORW",		"USERS",	"WALL"
182 };
183 
184 struct	filed *Files;
185 struct	filed consfile;
186 
187 int	Debug;			/* debug flag */
188 char	LocalHostName[MAXHOSTNAMELEN];	/* our hostname */
189 char	*LocalDomain;		/* our local domain name */
190 int	InetInuse = 0;		/* non-zero if INET sockets are being used */
191 int	finet;			/* Internet datagram socket */
192 int	LogPort;		/* port number for INET connections */
193 int	Initialized = 0;	/* set when we have initialized ourselves */
194 
195 int	MarkInterval = 20 * 60;	/* interval between marks in seconds */
196 int	MarkSeq = 0;		/* mark sequence number */
197 
198 sig_atomic_t MarkSet;
199 sig_atomic_t WantDie;
200 
201 int	SecureMode = 1;		/* when true, speak only unix domain socks */
202 
203 void	cfline __P((char *, struct filed *, char *));
204 char   *cvthname __P((struct sockaddr_in *));
205 int	decode __P((const char *, CODE *));
206 void	dodie __P((int));
207 void	die __P((int));
208 void	domark __P((int));
209 void	markit __P((void));
210 void	fprintlog __P((struct filed *, int, char *));
211 void	init __P((int));
212 void	logerror __P((char *));
213 void	logmsg __P((int, char *, char *, int));
214 void	printline __P((char *, char *));
215 void	printsys __P((char *));
216 void	reapchild __P((int));
217 char   *ttymsg __P((struct iovec *, int, char *, int));
218 void	usage __P((void));
219 void	wallmsg __P((struct filed *, struct iovec *));
220 
221 #define MAXFUNIX	21
222 
223 int nfunix = 1;
224 char *funixn[MAXFUNIX] = { _PATH_LOG };
225 int funix[MAXFUNIX];
226 
227 int
228 main(argc, argv)
229 	int argc;
230 	char *argv[];
231 {
232 	int ch, i, fklog, len, linesize, fdsrmax = 0;
233 	struct sockaddr_un sunx, fromunix;
234 	struct sockaddr_in sin, frominet;
235 	fd_set *fdsr = NULL;
236 	char *p, *line;
237 	FILE *fp;
238 
239 	while ((ch = getopt(argc, argv, "duf:m:p:a:")) != -1)
240 		switch (ch) {
241 		case 'd':		/* debug */
242 			Debug++;
243 			break;
244 		case 'f':		/* configuration file */
245 			ConfFile = optarg;
246 			break;
247 		case 'm':		/* mark interval */
248 			MarkInterval = atoi(optarg) * 60;
249 			break;
250 		case 'p':		/* path */
251 			funixn[0] = optarg;
252 			break;
253 		case 'u':		/* allow udp input port */
254 			SecureMode = 0;
255 			break;
256 		case 'a':
257 			if (nfunix >= MAXFUNIX)
258 				fprintf(stderr,
259 				    "syslogd: out of descriptors, ignoring %s\n",
260 				    optarg);
261 			else if (strlen(optarg) >= sizeof(sunx.sun_path))
262 				fprintf(stderr,
263 				    "syslogd: path too long, ignoring %s\n",
264 				    optarg);
265 			else
266 				funixn[nfunix++] = optarg;
267 			break;
268 		case '?':
269 		default:
270 			usage();
271 		}
272 	if ((argc -= optind) != 0)
273 		usage();
274 
275 	if (!Debug)
276 		(void)daemon(0, 0);
277 	else
278 		setlinebuf(stdout);
279 
280 	consfile.f_type = F_CONSOLE;
281 	(void)strlcpy(consfile.f_un.f_fname, ctty,
282 	    sizeof(consfile.f_un.f_fname));
283 	(void)gethostname(LocalHostName, sizeof(LocalHostName));
284 	if ((p = strchr(LocalHostName, '.')) != NULL) {
285 		*p++ = '\0';
286 		LocalDomain = p;
287 	} else
288 		LocalDomain = "";
289 
290 	linesize = getmsgbufsize();
291 	if (linesize < MAXLINE)
292 		linesize = MAXLINE;
293 	linesize++;
294 	line = malloc(linesize);
295 
296 	(void)signal(SIGTERM, dodie);
297 	(void)signal(SIGINT, Debug ? dodie : SIG_IGN);
298 	(void)signal(SIGQUIT, Debug ? dodie : SIG_IGN);
299 	(void)signal(SIGCHLD, reapchild);
300 	(void)signal(SIGALRM, domark);
301 	(void)alarm(TIMERINTVL);
302 
303 #ifndef SUN_LEN
304 #define SUN_LEN(unp) (strlen((unp)->sun_path) + 2)
305 #endif
306 	for (i = 0; i < nfunix; i++) {
307 		(void)unlink(funixn[i]);
308 
309 		memset(&sunx, 0, sizeof(sunx));
310 		sunx.sun_family = AF_UNIX;
311 		(void)strlcpy(sunx.sun_path, funixn[i], sizeof(sunx.sun_path));
312 		funix[i] = socket(AF_UNIX, SOCK_DGRAM, 0);
313 		if (funix[i] < 0 ||
314 		    bind(funix[i], (struct sockaddr *)&sunx,
315 		    SUN_LEN(&sunx)) < 0 ||
316 		    chmod(funixn[i], 0666) < 0) {
317 			(void) snprintf(line, sizeof line, "cannot create %s",
318 			    funixn[i]);
319 			logerror(line);
320 			dprintf("cannot create %s (%d)\n", funixn[i], errno);
321 			if (i == 0)
322 				die(0);
323 		}
324 	}
325 	finet = socket(AF_INET, SOCK_DGRAM, 0);
326 	if (finet >= 0) {
327 		struct servent *sp;
328 
329 		sp = getservbyname("syslog", "udp");
330 		if (sp == NULL) {
331 			errno = 0;
332 			logerror("syslog/udp: unknown service");
333 			die(0);
334 		}
335 		memset(&sin, 0, sizeof(sin));
336 		sin.sin_len = sizeof(sin);
337 		sin.sin_family = AF_INET;
338 		sin.sin_port = LogPort = sp->s_port;
339 		if (bind(finet, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
340 			logerror("bind");
341 			if (!Debug)
342 				die(0);
343 		} else {
344 			InetInuse = 1;
345 		}
346 	}
347 	if ((fklog = open(_PATH_KLOG, O_RDONLY, 0)) < 0)
348 		dprintf("can't open %s (%d)\n", _PATH_KLOG, errno);
349 
350 	/* tuck my process id away */
351 	if (!Debug) {
352 		fp = fopen(PidFile, "w");
353 		if (fp != NULL) {
354 			fprintf(fp, "%d\n", getpid());
355 			(void) fclose(fp);
356 		}
357 	}
358 
359 	dprintf("off & running....\n");
360 
361 	init(0);
362 	(void)signal(SIGHUP, init);
363 
364 	if (fklog != -1 && fklog > fdsrmax)
365 		fdsrmax = fklog;
366 	if (finet != -1 && finet > fdsrmax)
367 		fdsrmax = finet;
368 	for (i = 0; i < nfunix; i++) {
369 		if (funix[i] != -1 && funix[i] > fdsrmax)
370 			fdsrmax = funix[i];
371 	}
372 
373 	fdsr = (fd_set *)calloc(howmany(fdsrmax+1, NFDBITS),
374 	    sizeof(fd_mask));
375 	if (fdsr == NULL)
376 		errx(1, "calloc fd_set");
377 
378 	for (;;) {
379 		if (MarkSet)
380 			markit();
381 		if (WantDie)
382 			die(WantDie);
383 
384 		bzero(fdsr, howmany(fdsrmax+1, NFDBITS) *
385 		    sizeof(fd_mask));
386 
387 		if (fklog != -1)
388 			FD_SET(fklog, fdsr);
389 		if (finet != -1)
390 			FD_SET(finet, fdsr);
391 		for (i = 0; i < nfunix; i++) {
392 			if (funix[i] != -1)
393 				FD_SET(funix[i], fdsr);
394 		}
395 
396 		switch (select(fdsrmax+1, fdsr, NULL, NULL, NULL)) {
397 		case 0:
398 			continue;
399 		case -1:
400 			if (errno != EINTR)
401 				logerror("select");
402 			continue;
403 		}
404 
405 		if (fklog != -1 && FD_ISSET(fklog, fdsr)) {
406 			i = read(fklog, line, linesize - 1);
407 			if (i > 0) {
408 				line[i] = '\0';
409 				printsys(line);
410 			} else if (i < 0 && errno != EINTR) {
411 				logerror("klog");
412 				fklog = -1;
413 			}
414 		}
415 		if (finet != -1 && FD_ISSET(finet, fdsr)) {
416 			len = sizeof(frominet);
417 			i = recvfrom(finet, line, MAXLINE, 0,
418 			    (struct sockaddr *)&frominet, &len);
419 			if (SecureMode) {
420 				/* silently drop it */
421 			} else {
422 				if (i > 0) {
423 					line[i] = '\0';
424 					printline(cvthname(&frominet), line);
425 				} else if (i < 0 && errno != EINTR)
426 					logerror("recvfrom inet");
427 			}
428 		}
429 		for (i = 0; i < nfunix; i++) {
430 			if (funix[i] != -1 && FD_ISSET(funix[i], fdsr)) {
431 				len = sizeof(fromunix);
432 				len = recvfrom(funix[i], line, MAXLINE, 0,
433 				    (struct sockaddr *)&fromunix, &len);
434 				if (len > 0) {
435 					line[len] = '\0';
436 					printline(LocalHostName, line);
437 				} else if (len < 0 && errno != EINTR)
438 					logerror("recvfrom unix");
439 			}
440 		}
441 	}
442 	if (fdsr)
443 		free(fdsr);
444 }
445 
446 void
447 usage()
448 {
449 
450 	(void)fprintf(stderr,
451 	    "usage: syslogd [-u] [-f conffile] [-m markinterval] [-p logpath] [-a logpath]\n");
452 	exit(1);
453 }
454 
455 /*
456  * Take a raw input line, decode the message, and print the message
457  * on the appropriate log files.
458  */
459 void
460 printline(hname, msg)
461 	char *hname;
462 	char *msg;
463 {
464 	int pri;
465 	char *p, *q, line[MAXLINE + 1];
466 
467 	/* test for special codes */
468 	pri = DEFUPRI;
469 	p = msg;
470 	if (*p == '<') {
471 		pri = 0;
472 		while (isdigit(*++p))
473 			pri = 10 * pri + (*p - '0');
474 		if (*p == '>')
475 			++p;
476 	}
477 	if (pri &~ (LOG_FACMASK|LOG_PRIMASK))
478 		pri = DEFUPRI;
479 
480 	/* don't allow users to log kernel messages */
481 	if (LOG_FAC(pri) == LOG_KERN)
482 		pri = LOG_MAKEPRI(LOG_USER, LOG_PRI(pri));
483 
484 	for (q = line; *p && q < &line[sizeof(line) - 4]; p++) {
485 		if (*p == '\n')
486 			*q++ = ' ';
487 		else
488 			q = vis(q, *p, 0, 0);
489 	}
490 	*q = '\0';
491 
492 	logmsg(pri, line, hname, 0);
493 }
494 
495 /*
496  * Take a raw input line from /dev/klog, split and format similar to syslog().
497  */
498 void
499 printsys(msg)
500 	char *msg;
501 {
502 	int c, pri, flags;
503 	char *lp, *p, *q, line[MAXLINE + 1];
504 
505 	snprintf(line, sizeof line, "%s: ", _PATH_UNIX);
506 	lp = line + strlen(line);
507 	for (p = msg; *p != '\0'; ) {
508 		flags = SYNC_FILE | ADDDATE;	/* fsync file after write */
509 		pri = DEFSPRI;
510 		if (*p == '<') {
511 			pri = 0;
512 			while (isdigit(*++p))
513 				pri = 10 * pri + (*p - '0');
514 			if (*p == '>')
515 				++p;
516 		} else {
517 			/* kernel printf's come out on console */
518 			flags |= IGN_CONS;
519 		}
520 		if (pri &~ (LOG_FACMASK|LOG_PRIMASK))
521 			pri = DEFSPRI;
522 
523 		q = lp;
524 		while (*p && (c = *p++) != '\n' && q < &line[sizeof(line) - 4])
525 			q = vis(q, c, 0, 0);
526 
527 		logmsg(pri, line, LocalHostName, flags);
528 	}
529 }
530 
531 time_t	now;
532 
533 /*
534  * Log a message to the appropriate log files, users, etc. based on
535  * the priority.
536  */
537 void
538 logmsg(pri, msg, from, flags)
539 	int pri;
540 	char *msg, *from;
541 	int flags;
542 {
543 	struct filed *f;
544 	int fac, msglen, prilev, i;
545 	sigset_t mask, omask;
546 	char *timestamp;
547  	char prog[NAME_MAX+1];
548 
549 	dprintf("logmsg: pri 0%o, flags 0x%x, from %s, msg %s\n",
550 	    pri, flags, from, msg);
551 
552 	sigemptyset(&mask);
553 	sigaddset(&mask, SIGALRM);
554 	sigaddset(&mask, SIGHUP);
555 	sigprocmask(SIG_BLOCK, &mask, &omask);
556 
557 	/*
558 	 * Check to see if msg looks non-standard.
559 	 */
560 	msglen = strlen(msg);
561 	if (msglen < 16 || msg[3] != ' ' || msg[6] != ' ' ||
562 	    msg[9] != ':' || msg[12] != ':' || msg[15] != ' ')
563 		flags |= ADDDATE;
564 
565 	(void)time(&now);
566 	if (flags & ADDDATE)
567 		timestamp = ctime(&now) + 4;
568 	else {
569 		timestamp = msg;
570 		msg += 16;
571 		msglen -= 16;
572 	}
573 
574 	/* extract facility and priority level */
575 	if (flags & MARK)
576 		fac = LOG_NFACILITIES;
577 	else
578 		fac = LOG_FAC(pri);
579 	prilev = LOG_PRI(pri);
580 
581 	/* extract program name */
582 	for(i = 0; i < NAME_MAX; i++) {
583 		if (!isalnum(msg[i]))
584 			break;
585 		prog[i] = msg[i];
586 	}
587 	prog[i] = 0;
588 
589 	/* log the message to the particular outputs */
590 	if (!Initialized) {
591 		f = &consfile;
592 		f->f_file = open(ctty, O_WRONLY|O_NONBLOCK, 0);
593 
594 		if (f->f_file >= 0) {
595 			fprintlog(f, flags, msg);
596 			(void)close(f->f_file);
597 			f->f_file = -1;
598 		}
599 		(void)sigprocmask(SIG_SETMASK, &omask, NULL);
600 		return;
601 	}
602 	for (f = Files; f; f = f->f_next) {
603 		/* skip messages that are incorrect priority */
604 		if (f->f_pmask[fac] < prilev ||
605 		    f->f_pmask[fac] == INTERNAL_NOPRI)
606 			continue;
607 
608 		/* skip messages with the incorrect program name */
609 		if (f->f_program)
610 			if (strcmp(prog, f->f_program) != 0)
611 				continue;
612 
613 		if (f->f_type == F_CONSOLE && (flags & IGN_CONS))
614 			continue;
615 
616 		/* don't output marks to recently written files */
617 		if ((flags & MARK) && (now - f->f_time) < MarkInterval / 2)
618 			continue;
619 
620 		/*
621 		 * suppress duplicate lines to this file
622 		 */
623 		if ((flags & MARK) == 0 && msglen == f->f_prevlen &&
624 		    !strcmp(msg, f->f_prevline) &&
625 		    !strcmp(from, f->f_prevhost)) {
626 			strlcpy(f->f_lasttime, timestamp, 16);
627 			f->f_prevcount++;
628 			dprintf("msg repeated %d times, %ld sec of %d\n",
629 			    f->f_prevcount, (long)(now - f->f_time),
630 			    repeatinterval[f->f_repeatcount]);
631 			/*
632 			 * If domark would have logged this by now,
633 			 * flush it now (so we don't hold isolated messages),
634 			 * but back off so we'll flush less often
635 			 * in the future.
636 			 */
637 			if (now > REPEATTIME(f)) {
638 				fprintlog(f, flags, (char *)NULL);
639 				BACKOFF(f);
640 			}
641 		} else {
642 			/* new line, save it */
643 			if (f->f_prevcount)
644 				fprintlog(f, 0, (char *)NULL);
645 			f->f_repeatcount = 0;
646 			f->f_prevpri = pri;
647 			strlcpy(f->f_lasttime, timestamp, 16);
648 			strlcpy(f->f_prevhost, from,
649 			    sizeof(f->f_prevhost));
650 			if (msglen < MAXSVLINE) {
651 				f->f_prevlen = msglen;
652 				strlcpy(f->f_prevline, msg, sizeof(f->f_prevline));
653 				fprintlog(f, flags, (char *)NULL);
654 			} else {
655 				f->f_prevline[0] = 0;
656 				f->f_prevlen = 0;
657 				fprintlog(f, flags, msg);
658 			}
659 		}
660 	}
661 	(void)sigprocmask(SIG_SETMASK, &omask, NULL);
662 }
663 
664 void
665 fprintlog(f, flags, msg)
666 	struct filed *f;
667 	int flags;
668 	char *msg;
669 {
670 	struct iovec iov[6];
671 	struct iovec *v;
672 	int l;
673 	char line[MAXLINE + 1], repbuf[80], greetings[500];
674 
675 	v = iov;
676 	if (f->f_type == F_WALL) {
677 		v->iov_base = greetings;
678 		v->iov_len = snprintf(greetings, sizeof(greetings),
679 		    "\r\n\7Message from syslogd@%s at %.24s ...\r\n",
680 		    f->f_prevhost, ctime(&now));
681 		if (v->iov_len >= sizeof(greetings))
682 			v->iov_len = sizeof(greetings) - 1;
683 		v++;
684 		v->iov_base = "";
685 		v->iov_len = 0;
686 		v++;
687 	} else {
688 		v->iov_base = f->f_lasttime;
689 		v->iov_len = 15;
690 		v++;
691 		v->iov_base = " ";
692 		v->iov_len = 1;
693 		v++;
694 	}
695 	v->iov_base = f->f_prevhost;
696 	v->iov_len = strlen(v->iov_base);
697 	v++;
698 	v->iov_base = " ";
699 	v->iov_len = 1;
700 	v++;
701 
702 	if (msg) {
703 		v->iov_base = msg;
704 		v->iov_len = strlen(msg);
705 	} else if (f->f_prevcount > 1) {
706 		v->iov_base = repbuf;
707 		v->iov_len = snprintf(repbuf, sizeof repbuf,
708 		    "last message repeated %d times", f->f_prevcount);
709 	} else {
710 		v->iov_base = f->f_prevline;
711 		v->iov_len = f->f_prevlen;
712 	}
713 	v++;
714 
715 	dprintf("Logging to %s", TypeNames[f->f_type]);
716 	f->f_time = now;
717 
718 	switch (f->f_type) {
719 	case F_UNUSED:
720 		dprintf("\n");
721 		break;
722 
723 	case F_FORW:
724 		dprintf(" %s\n", f->f_un.f_forw.f_hname);
725 		l = snprintf(line, sizeof(line) - 1, "<%d>%.15s %s", f->f_prevpri,
726 		    (char *)iov[0].iov_base, (char *)iov[4].iov_base);
727 		if (l > MAXLINE)
728 			l = MAXLINE;
729 		if (sendto(finet, line, l, 0,
730 		    (struct sockaddr *)&f->f_un.f_forw.f_addr,
731 		    sizeof(f->f_un.f_forw.f_addr)) != l) {
732 			f->f_type = F_UNUSED;
733 			logerror("sendto");
734 		}
735 		break;
736 
737 	case F_CONSOLE:
738 		if (flags & IGN_CONS) {
739 			dprintf(" (ignored)\n");
740 			break;
741 		}
742 		/* FALLTHROUGH */
743 
744 	case F_TTY:
745 	case F_FILE:
746 		dprintf(" %s\n", f->f_un.f_fname);
747 		if (f->f_type != F_FILE) {
748 			v->iov_base = "\r\n";
749 			v->iov_len = 2;
750 		} else {
751 			v->iov_base = "\n";
752 			v->iov_len = 1;
753 		}
754 	again:
755 		if (writev(f->f_file, iov, 6) < 0) {
756 			int e = errno;
757 			(void)close(f->f_file);
758 			/*
759 			 * Check for errors on TTY's due to loss of tty
760 			 */
761 			if (e == EAGAIN) {
762 				/*
763 				 * Silently drop messages on blocked write.
764 				 * This can happen when logging to a locked tty.
765 				 */
766 				break;
767 			} else if ((e == EIO || e == EBADF) &&
768 			    f->f_type != F_FILE) {
769 				f->f_file = open(f->f_un.f_fname,
770 				    O_WRONLY|O_APPEND|O_NONBLOCK, 0);
771 				if (f->f_file < 0) {
772 					f->f_type = F_UNUSED;
773 					logerror(f->f_un.f_fname);
774 				} else
775 					goto again;
776 			} else {
777 				f->f_type = F_UNUSED;
778 				f->f_file = -1;
779 				errno = e;
780 				logerror(f->f_un.f_fname);
781 			}
782 		} else if (flags & SYNC_FILE)
783 			(void)fsync(f->f_file);
784 		break;
785 
786 	case F_USERS:
787 	case F_WALL:
788 		dprintf("\n");
789 		v->iov_base = "\r\n";
790 		v->iov_len = 2;
791 		wallmsg(f, iov);
792 		break;
793 	}
794 	f->f_prevcount = 0;
795 }
796 
797 /*
798  *  WALLMSG -- Write a message to the world at large
799  *
800  *	Write the specified message to either the entire
801  *	world, or a list of approved users.
802  */
803 void
804 wallmsg(f, iov)
805 	struct filed *f;
806 	struct iovec *iov;
807 {
808 	static int reenter;			/* avoid calling ourselves */
809 	FILE *uf;
810 	struct utmp ut;
811 	int i;
812 	char *p;
813 	char line[sizeof(ut.ut_line) + 1];
814 
815 	if (reenter++)
816 		return;
817 	if ((uf = fopen(_PATH_UTMP, "r")) == NULL) {
818 		logerror(_PATH_UTMP);
819 		reenter = 0;
820 		return;
821 	}
822 	/* NOSTRICT */
823 	while (fread((char *)&ut, sizeof(ut), 1, uf) == 1) {
824 		if (ut.ut_name[0] == '\0')
825 			continue;
826 		strlcpy(line, ut.ut_line, sizeof(line));
827 		if (f->f_type == F_WALL) {
828 			if ((p = ttymsg(iov, 6, line, TTYMSGTIME)) != NULL) {
829 				errno = 0;	/* already in msg */
830 				logerror(p);
831 			}
832 			continue;
833 		}
834 		/* should we send the message to this user? */
835 		for (i = 0; i < MAXUNAMES; i++) {
836 			if (!f->f_un.f_uname[i][0])
837 				break;
838 			if (!strncmp(f->f_un.f_uname[i], ut.ut_name,
839 			    UT_NAMESIZE)) {
840 				if ((p = ttymsg(iov, 6, line, TTYMSGTIME))
841 								!= NULL) {
842 					errno = 0;	/* already in msg */
843 					logerror(p);
844 				}
845 				break;
846 			}
847 		}
848 	}
849 	(void)fclose(uf);
850 	reenter = 0;
851 }
852 
853 void
854 reapchild(signo)
855 	int signo;
856 {
857 	int status;
858 	int save_errno = errno;
859 
860 	while (waitpid(-1, &status, WNOHANG) > 0)
861 		;
862 	errno = save_errno;
863 }
864 
865 /*
866  * Return a printable representation of a host address.
867  */
868 char *
869 cvthname(f)
870 	struct sockaddr_in *f;
871 {
872 	struct hostent *hp;
873 	sigset_t omask, nmask;
874 	char *p;
875 
876 	dprintf("cvthname(%s)\n", inet_ntoa(f->sin_addr));
877 
878 	if (f->sin_family != AF_INET) {
879 		dprintf("Malformed from address\n");
880 		return ("???");
881 	}
882 	sigemptyset(&nmask);
883 	sigaddset(&nmask, SIGHUP);
884 	sigprocmask(SIG_BLOCK, &nmask, &omask);
885 	hp = gethostbyaddr((char *)&f->sin_addr,
886 	    sizeof(struct in_addr), f->sin_family);
887 	sigprocmask(SIG_SETMASK, &omask, NULL);
888 	if (hp == 0) {
889 		dprintf("Host name for your address (%s) unknown\n",
890 			inet_ntoa(f->sin_addr));
891 		return (inet_ntoa(f->sin_addr));
892 	}
893 	if ((p = strchr(hp->h_name, '.')) && strcmp(p + 1, LocalDomain) == 0)
894 		*p = '\0';
895 	return (hp->h_name);
896 }
897 
898 void
899 dodie(signo)
900 	int signo;
901 {
902 	WantDie = signo;
903 }
904 
905 void
906 domark(signo)
907 	int signo;
908 {
909 	MarkSet = 1;
910 }
911 
912 /*
913  * Print syslogd errors some place.
914  */
915 void
916 logerror(type)
917 	char *type;
918 {
919 	char buf[100];
920 
921 	if (errno)
922 		(void)snprintf(buf, sizeof(buf), "syslogd: %s: %s",
923 		    type, strerror(errno));
924 	else
925 		(void)snprintf(buf, sizeof(buf), "syslogd: %s", type);
926 	errno = 0;
927 	dprintf("%s\n", buf);
928 	logmsg(LOG_SYSLOG|LOG_ERR, buf, LocalHostName, ADDDATE);
929 }
930 
931 void
932 die(signo)
933 	int signo;
934 {
935 	struct filed *f;
936 	int was_initialized = Initialized;
937 	char buf[100];
938 	int i;
939 
940 	Initialized = 0;		/* Don't log SIGCHLDs */
941 	alarm(0);
942 	for (f = Files; f != NULL; f = f->f_next) {
943 		/* flush any pending output */
944 		if (f->f_prevcount)
945 			fprintlog(f, 0, (char *)NULL);
946 	}
947 	Initialized = was_initialized;
948 	if (signo) {
949 		dprintf("syslogd: exiting on signal %d\n", signo);
950 		(void)snprintf(buf, sizeof buf, "exiting on signal %d", signo);
951 		errno = 0;
952 		logerror(buf);
953 	}
954 	for (i = 0; i < nfunix; i++)
955 		if (funixn[i] && funix[i] != -1)
956 			(void)unlink(funixn[i]);
957 	exit(0);
958 }
959 
960 /*
961  *  INIT -- Initialize syslogd from configuration table
962  */
963 void
964 init(signo)
965 	int signo;
966 {
967 	int i;
968 	FILE *cf;
969 	struct filed *f, *next, **nextp;
970 	char *p;
971 	char cline[LINE_MAX];
972  	char prog[NAME_MAX+1];
973 	int save_errno = errno;
974 
975 	dprintf("init\n");
976 
977 	/*
978 	 *  Close all open log files.
979 	 */
980 	Initialized = 0;
981 	for (f = Files; f != NULL; f = next) {
982 		/* flush any pending output */
983 		if (f->f_prevcount)
984 			fprintlog(f, 0, (char *)NULL);
985 
986 		switch (f->f_type) {
987 		case F_FILE:
988 		case F_TTY:
989 		case F_CONSOLE:
990 			(void)close(f->f_file);
991 			break;
992 		case F_FORW:
993 			break;
994 		}
995 		next = f->f_next;
996 		if (f->f_program)
997 			free(f->f_program);
998 		free((char *)f);
999 	}
1000 	Files = NULL;
1001 	nextp = &Files;
1002 
1003 	/* open the configuration file */
1004 	if ((cf = fopen(ConfFile, "r")) == NULL) {
1005 		dprintf("cannot open %s\n", ConfFile);
1006 		*nextp = (struct filed *)calloc(1, sizeof(*f));
1007 		cfline("*.ERR\t/dev/console", *nextp, "*");
1008 		(*nextp)->f_next = (struct filed *)calloc(1, sizeof(*f));
1009 		cfline("*.PANIC\t*", (*nextp)->f_next, "*");
1010 		Initialized = 1;
1011 		errno = save_errno;
1012 		return;
1013 	}
1014 
1015 	/*
1016 	 *  Foreach line in the conf table, open that file.
1017 	 */
1018 	f = NULL;
1019 	strlcpy(prog, "*", sizeof(prog));
1020 	while (fgets(cline, sizeof(cline), cf) != NULL) {
1021 		/*
1022 		 * check for end-of-section, comments, strip off trailing
1023 		 * spaces and newline character. !prog is treated
1024 		 * specially: the following lines apply only to that program.
1025 		 */
1026 		for (p = cline; isspace(*p); ++p)
1027 			continue;
1028 		if (*p == '\0' || *p == '#')
1029 			continue;
1030 		if (*p == '!') {
1031 			p++;
1032 			while (isspace(*p))
1033 				p++;
1034 			if (!*p) {
1035 				strlcpy(prog, "*", sizeof(prog));
1036 				continue;
1037 			}
1038 			for (i = 0; i < NAME_MAX; i++) {
1039 				if (!isalnum(p[i]))
1040 					break;
1041 				prog[i] = p[i];
1042 			}
1043 			prog[i] = 0;
1044 			continue;
1045 		}
1046 		p = cline + strlen(cline);
1047 		while (p > cline)
1048 			if (!isspace(*--p)) {
1049 				p++;
1050 				break;
1051 			}
1052 		*p = '\0';
1053 		f = (struct filed *)calloc(1, sizeof(*f));
1054 		*nextp = f;
1055 		nextp = &f->f_next;
1056 		cfline(cline, f, prog);
1057 	}
1058 
1059 	/* close the configuration file */
1060 	(void)fclose(cf);
1061 
1062 	Initialized = 1;
1063 
1064 	if (Debug) {
1065 		for (f = Files; f; f = f->f_next) {
1066 			for (i = 0; i <= LOG_NFACILITIES; i++)
1067 				if (f->f_pmask[i] == INTERNAL_NOPRI)
1068 					printf("X ");
1069 				else
1070 					printf("%d ", f->f_pmask[i]);
1071 			printf("%s: ", TypeNames[f->f_type]);
1072 			switch (f->f_type) {
1073 			case F_FILE:
1074 			case F_TTY:
1075 			case F_CONSOLE:
1076 				printf("%s", f->f_un.f_fname);
1077 				break;
1078 
1079 			case F_FORW:
1080 				printf("%s", f->f_un.f_forw.f_hname);
1081 				break;
1082 
1083 			case F_USERS:
1084 				for (i = 0; i < MAXUNAMES && *f->f_un.f_uname[i]; i++)
1085 					printf("%s, ", f->f_un.f_uname[i]);
1086 				break;
1087 			}
1088 			if (f->f_program)
1089 				printf(" (%s)", f->f_program);
1090 			printf("\n");
1091 		}
1092 	}
1093 
1094 	logmsg(LOG_SYSLOG|LOG_INFO, "syslogd: restart", LocalHostName,
1095 	    ADDDATE);
1096 	dprintf("syslogd: restarted\n");
1097 	errno = save_errno;
1098 }
1099 
1100 /*
1101  * Crack a configuration file line
1102  */
1103 void
1104 cfline(line, f, prog)
1105 	char *line;
1106 	struct filed *f;
1107 	char *prog;
1108 {
1109 	struct hostent *hp;
1110 	int i, pri;
1111 	char *bp, *p, *q;
1112 	char buf[MAXLINE], ebuf[100];
1113 
1114 	dprintf("cfline(\"%s\", f, \"%s\")\n", line, prog);
1115 
1116 	errno = 0;	/* keep strerror() stuff out of logerror messages */
1117 
1118 	/* clear out file entry */
1119 	memset(f, 0, sizeof(*f));
1120 	for (i = 0; i <= LOG_NFACILITIES; i++)
1121 		f->f_pmask[i] = INTERNAL_NOPRI;
1122 
1123 	/* save program name if any */
1124 	if (!strcmp(prog, "*"))
1125 		prog = NULL;
1126 	else {
1127 		f->f_program = calloc(1, strlen(prog)+1);
1128 		if (f->f_program)
1129 			strlcpy(f->f_program, prog, strlen(prog)+1);
1130 	}
1131 
1132 	/* scan through the list of selectors */
1133 	for (p = line; *p && *p != '\t';) {
1134 
1135 		/* find the end of this facility name list */
1136 		for (q = p; *q && *q != '\t' && *q++ != '.'; )
1137 			continue;
1138 
1139 		/* collect priority name */
1140 		for (bp = buf; *q && !strchr("\t,;", *q); )
1141 			*bp++ = *q++;
1142 		*bp = '\0';
1143 
1144 		/* skip cruft */
1145 		while (strchr(", ;", *q))
1146 			q++;
1147 
1148 		/* decode priority name */
1149 		if (*buf == '*')
1150 			pri = LOG_PRIMASK + 1;
1151 		else {
1152 			/* ignore trailing spaces */
1153 			int i;
1154 			for (i=strlen(buf)-1; i >= 0 && buf[i] == ' '; i--) {
1155 				buf[i]='\0';
1156 			}
1157 
1158 			pri = decode(buf, prioritynames);
1159 			if (pri < 0) {
1160 				(void)snprintf(ebuf, sizeof ebuf,
1161 				    "unknown priority name \"%s\"", buf);
1162 				logerror(ebuf);
1163 				return;
1164 			}
1165 		}
1166 
1167 		/* scan facilities */
1168 		while (*p && !strchr("\t.;", *p)) {
1169 			for (bp = buf; *p && !strchr("\t,;.", *p); )
1170 				*bp++ = *p++;
1171 			*bp = '\0';
1172 			if (*buf == '*')
1173 				for (i = 0; i < LOG_NFACILITIES; i++)
1174 					f->f_pmask[i] = pri;
1175 			else {
1176 				i = decode(buf, facilitynames);
1177 				if (i < 0) {
1178 					(void)snprintf(ebuf, sizeof(ebuf),
1179 					    "unknown facility name \"%s\"",
1180 					    buf);
1181 					logerror(ebuf);
1182 					return;
1183 				}
1184 				f->f_pmask[i >> 3] = pri;
1185 			}
1186 			while (*p == ',' || *p == ' ')
1187 				p++;
1188 		}
1189 
1190 		p = q;
1191 	}
1192 
1193 	/* skip to action part */
1194 	while (*p == '\t')
1195 		p++;
1196 
1197 	switch (*p)
1198 	{
1199 	case '@':
1200 		if (!InetInuse)
1201 			break;
1202 		(void)strlcpy(f->f_un.f_forw.f_hname, ++p,
1203 		    sizeof(f->f_un.f_forw.f_hname));
1204 		hp = gethostbyname(f->f_un.f_forw.f_hname);
1205 		if (hp == NULL) {
1206 			extern int h_errno;
1207 
1208 			logerror((char *)hstrerror(h_errno));
1209 			break;
1210 		}
1211 		memset(&f->f_un.f_forw.f_addr, 0,
1212 		    sizeof(f->f_un.f_forw.f_addr));
1213 		f->f_un.f_forw.f_addr.sin_len = sizeof(f->f_un.f_forw.f_addr);
1214 		f->f_un.f_forw.f_addr.sin_family = AF_INET;
1215 		f->f_un.f_forw.f_addr.sin_port = LogPort;
1216 		memmove(&f->f_un.f_forw.f_addr.sin_addr, hp->h_addr,
1217 		    hp->h_length);
1218 		f->f_type = F_FORW;
1219 		break;
1220 
1221 	case '/':
1222 		(void)strlcpy(f->f_un.f_fname, p, sizeof(f->f_un.f_fname));
1223 		f->f_file = open(p, O_WRONLY|O_APPEND|O_NONBLOCK, 0);
1224 		if (f->f_file < 0) {
1225 			f->f_type = F_UNUSED;
1226 			logerror(p);
1227 			break;
1228 		}
1229 		if (isatty(f->f_file)) {
1230 			if (strcmp(p, ctty) == 0)
1231 				f->f_type = F_CONSOLE;
1232 			else
1233 				f->f_type = F_TTY;
1234 		} else {
1235 			f->f_type = F_FILE;
1236 			/* Clear O_NONBLOCK flag on f->f_file */
1237 			if ((i = fcntl(f->f_file, F_GETFL, 0)) != -1) {
1238 				i &= ~O_NONBLOCK;
1239 				fcntl(f->f_file, F_SETFL, i);
1240 			}
1241 		}
1242 		break;
1243 
1244 	case '*':
1245 		f->f_type = F_WALL;
1246 		break;
1247 
1248 	default:
1249 		for (i = 0; i < MAXUNAMES && *p; i++) {
1250 			for (q = p; *q && *q != ','; )
1251 				q++;
1252 			(void)strncpy(f->f_un.f_uname[i], p, UT_NAMESIZE);
1253 			if ((q - p) > UT_NAMESIZE)
1254 				f->f_un.f_uname[i][UT_NAMESIZE] = '\0';
1255 			else
1256 				f->f_un.f_uname[i][q - p] = '\0';
1257 			while (*q == ',' || *q == ' ')
1258 				q++;
1259 			p = q;
1260 		}
1261 		f->f_type = F_USERS;
1262 		break;
1263 	}
1264 }
1265 
1266 
1267 /*
1268  * Retrieve the size of the kernel message buffer, via sysctl.
1269  */
1270 int
1271 getmsgbufsize()
1272 {
1273 	int msgbufsize, mib[2];
1274 	size_t size;
1275 
1276 	mib[0] = CTL_KERN;
1277 	mib[1] = KERN_MSGBUFSIZE;
1278 	size = sizeof msgbufsize;
1279 	if (sysctl(mib, 2, &msgbufsize, &size, NULL, 0) == -1) {
1280 		dprintf("couldn't get kern.msgbufsize\n");
1281 		return (0);
1282 	}
1283 	return (msgbufsize);
1284 }
1285 
1286 /*
1287  *  Decode a symbolic name to a numeric value
1288  */
1289 int
1290 decode(name, codetab)
1291 	const char *name;
1292 	CODE *codetab;
1293 {
1294 	CODE *c;
1295 	char *p, buf[40];
1296 
1297 	if (isdigit(*name))
1298 		return (atoi(name));
1299 
1300 	for (p = buf; *name && p < &buf[sizeof(buf) - 1]; p++, name++) {
1301 		if (isupper(*name))
1302 			*p = tolower(*name);
1303 		else
1304 			*p = *name;
1305 	}
1306 	*p = '\0';
1307 	for (c = codetab; c->c_name; c++)
1308 		if (!strcmp(buf, c->c_name))
1309 			return (c->c_val);
1310 
1311 	return (-1);
1312 }
1313 
1314 void
1315 markit(void)
1316 {
1317 	struct filed *f;
1318 
1319 	now = time((time_t *)NULL);
1320 	MarkSeq += TIMERINTVL;
1321 	if (MarkSeq >= MarkInterval) {
1322 		logmsg(LOG_INFO, "-- MARK --",
1323 		    LocalHostName, ADDDATE|MARK);
1324 		MarkSeq = 0;
1325 	}
1326 
1327 	for (f = Files; f; f = f->f_next) {
1328 		if (f->f_prevcount && now >= REPEATTIME(f)) {
1329 			dprintf("flush %s: repeated %d times, %d sec.\n",
1330 			    TypeNames[f->f_type], f->f_prevcount,
1331 			    repeatinterval[f->f_repeatcount]);
1332 			fprintlog(f, 0, (char *)NULL);
1333 			BACKOFF(f);
1334 		}
1335 	}
1336 	MarkSet = 0;
1337 	(void)alarm(TIMERINTVL);
1338 }
1339