xref: /netbsd-src/usr.sbin/syslogd/syslogd.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*
2  * Copyright (c) 1983, 1988, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 #ifndef lint
36 __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993, 1994\n\
37 	The Regents of the University of California.  All rights reserved.\n");
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)syslogd.c	8.3 (Berkeley) 4/4/94";
43 #else
44 __RCSID("$NetBSD: syslogd.c,v 1.17 1997/10/24 01:41:47 mrg Exp $");
45 #endif
46 #endif /* not lint */
47 
48 /*
49  *  syslogd -- log system messages
50  *
51  * This program implements a system log. It takes a series of lines.
52  * Each line may have a priority, signified as "<n>" as
53  * the first characters of the line.  If this is
54  * not present, a default priority is used.
55  *
56  * To kill syslogd, send a signal 15 (terminate).  A signal 1 (hup) will
57  * cause it to reread its configuration file.
58  *
59  * Defined Constants:
60  *
61  * MAXLINE -- the maximimum line length that can be handled.
62  * DEFUPRI -- the default priority for user messages
63  * DEFSPRI -- the default priority for kernel messages
64  *
65  * Author: Eric Allman
66  * extensive changes by Ralph Campbell
67  * more extensive changes by Eric Allman (again)
68  */
69 
70 #define	MAXLINE		1024		/* maximum line length */
71 #define	MAXSVLINE	120		/* maximum saved line length */
72 #define DEFUPRI		(LOG_USER|LOG_NOTICE)
73 #define DEFSPRI		(LOG_KERN|LOG_CRIT)
74 #define TIMERINTVL	30		/* interval for checking flush, mark */
75 #define TTYMSGTIME	1		/* timeout passed to ttymsg */
76 
77 #include <sys/param.h>
78 #include <sys/ioctl.h>
79 #include <sys/stat.h>
80 #include <sys/wait.h>
81 #include <sys/socket.h>
82 #include <sys/msgbuf.h>
83 #include <sys/uio.h>
84 #include <sys/un.h>
85 #include <sys/time.h>
86 #include <sys/resource.h>
87 #include <sys/sysctl.h>
88 
89 #include <netinet/in.h>
90 #include <netdb.h>
91 #include <arpa/inet.h>
92 
93 #include <ctype.h>
94 #include <errno.h>
95 #include <fcntl.h>
96 #include <setjmp.h>
97 #include <signal.h>
98 #include <stdio.h>
99 #include <stdlib.h>
100 #include <string.h>
101 #include <unistd.h>
102 #include <utmp.h>
103 #include <util.h>
104 #include "pathnames.h"
105 
106 #define SYSLOG_NAMES
107 #include <sys/syslog.h>
108 
109 char	*LogName = _PATH_LOG;
110 char	*ConfFile = _PATH_LOGCONF;
111 char	*PidFile = _PATH_LOGPID;
112 char	ctty[] = _PATH_CONSOLE;
113 
114 #define FDMASK(fd)	(1 << (fd))
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 	union {
141 		char	f_uname[MAXUNAMES][UT_NAMESIZE+1];
142 		struct {
143 			char	f_hname[MAXHOSTNAMELEN+1];
144 			struct sockaddr_in	f_addr;
145 		} f_forw;		/* forwarding address */
146 		char	f_fname[MAXPATHLEN];
147 	} f_un;
148 	char	f_prevline[MAXSVLINE];		/* last message logged */
149 	char	f_lasttime[16];			/* time of last occurrence */
150 	char	f_prevhost[MAXHOSTNAMELEN+1];	/* host from which recd. */
151 	int	f_prevpri;			/* pri of f_prevline */
152 	int	f_prevlen;			/* length of f_prevline */
153 	int	f_prevcount;			/* repetition cnt of prevline */
154 	int	f_repeatcount;			/* number of "repeated" msgs */
155 };
156 
157 /*
158  * Intervals at which we flush out "message repeated" messages,
159  * in seconds after previous message is logged.  After each flush,
160  * we move to the next interval until we reach the largest.
161  */
162 int	repeatinterval[] = { 30, 120, 600 };	/* # of secs before flush */
163 #define	MAXREPEAT ((sizeof(repeatinterval) / sizeof(repeatinterval[0])) - 1)
164 #define	REPEATTIME(f)	((f)->f_time + repeatinterval[(f)->f_repeatcount])
165 #define	BACKOFF(f)	{ if (++(f)->f_repeatcount > MAXREPEAT) \
166 				 (f)->f_repeatcount = MAXREPEAT; \
167 			}
168 
169 /* values for f_type */
170 #define F_UNUSED	0		/* unused entry */
171 #define F_FILE		1		/* regular file */
172 #define F_TTY		2		/* terminal */
173 #define F_CONSOLE	3		/* console terminal */
174 #define F_FORW		4		/* remote machine */
175 #define F_USERS		5		/* list of users */
176 #define F_WALL		6		/* everyone logged on */
177 
178 char	*TypeNames[7] = {
179 	"UNUSED",	"FILE",		"TTY",		"CONSOLE",
180 	"FORW",		"USERS",	"WALL"
181 };
182 
183 struct	filed *Files;
184 struct	filed consfile;
185 
186 int	Debug;			/* debug flag */
187 char	LocalHostName[MAXHOSTNAMELEN+1];	/* our hostname */
188 char	*LocalDomain;		/* our local domain name */
189 int	InetInuse = 0;		/* non-zero if INET sockets are being used */
190 int	finet;			/* Internet datagram socket */
191 int	LogPort;		/* port number for INET connections */
192 int	Initialized = 0;	/* set when we have initialized ourselves */
193 int	MarkInterval = 20 * 60;	/* interval between marks in seconds */
194 int	MarkSeq = 0;		/* mark sequence number */
195 int	SecureMode = 0;		/* when true, speak only unix domain socks */
196 
197 void	cfline __P((char *, struct filed *));
198 char   *cvthname __P((struct sockaddr_in *));
199 int	decode __P((const char *, CODE *));
200 void	die __P((int));
201 void	domark __P((int));
202 void	fprintlog __P((struct filed *, int, char *));
203 int	getmsgbufsize __P((void));
204 void	init __P((int));
205 void	logerror __P((char *));
206 void	logmsg __P((int, char *, char *, int));
207 void	printline __P((char *, char *));
208 void	printsys __P((char *));
209 void	reapchild __P((int));
210 void	usage __P((void));
211 void	wallmsg __P((struct filed *, struct iovec *));
212 int	main __P((int, char *[]));
213 
214 int
215 main(argc, argv)
216 	int argc;
217 	char *argv[];
218 {
219 	int ch, funix, i, inetm, fklog, klogm, len, linesize;
220 	struct sockaddr_un sunx, fromunix;
221 	struct sockaddr_in sin, frominet;
222 	FILE *fp;
223 	char *p, *line;
224 
225 	while ((ch = getopt(argc, argv, "dsf:m:p:")) != -1)
226 		switch(ch) {
227 		case 'd':		/* debug */
228 			Debug++;
229 			break;
230 		case 'f':		/* configuration file */
231 			ConfFile = optarg;
232 			break;
233 		case 'm':		/* mark interval */
234 			MarkInterval = atoi(optarg) * 60;
235 			break;
236 		case 'p':		/* path */
237 			LogName = optarg;
238 			break;
239 		case 's':		/* no network mode */
240 			SecureMode++;
241 			break;
242 		case '?':
243 		default:
244 			usage();
245 		}
246 	if ((argc -= optind) != 0)
247 		usage();
248 
249 	if (!Debug)
250 		(void)daemon(0, 0);
251 	else
252 		setlinebuf(stdout);
253 
254 	consfile.f_type = F_CONSOLE;
255 	(void)strcpy(consfile.f_un.f_fname, ctty);
256 	(void)gethostname(LocalHostName, sizeof(LocalHostName));
257 	if ((p = strchr(LocalHostName, '.')) != NULL) {
258 		*p++ = '\0';
259 		LocalDomain = p;
260 	} else
261 		LocalDomain = "";
262 	linesize = getmsgbufsize();
263 	if (linesize < MAXLINE)
264 		linesize = MAXLINE;
265 	linesize++;
266 	line = malloc(linesize);
267 	if (line == NULL) {
268 		logerror("couldn't allocate line buffer");
269 		die(0);
270 	}
271 	(void)signal(SIGTERM, die);
272 	(void)signal(SIGINT, Debug ? die : SIG_IGN);
273 	(void)signal(SIGQUIT, Debug ? die : SIG_IGN);
274 	(void)signal(SIGCHLD, reapchild);
275 	(void)signal(SIGALRM, domark);
276 	(void)alarm(TIMERINTVL);
277 	(void)unlink(LogName);
278 
279 #ifndef SUN_LEN
280 #define SUN_LEN(unp) (strlen((unp)->sun_path) + 2)
281 #endif
282 	memset(&sunx, 0, sizeof(sunx));
283 	sunx.sun_family = AF_UNIX;
284 	(void)strncpy(sunx.sun_path, LogName, sizeof(sunx.sun_path));
285 	funix = socket(AF_UNIX, SOCK_DGRAM, 0);
286 	if (funix < 0 ||
287 	    bind(funix, (struct sockaddr *)&sunx, SUN_LEN(&sunx)) < 0 ||
288 	    chmod(LogName, 0666) < 0) {
289 		(void)snprintf(line, sizeof line, "cannot create %s", LogName);
290 		logerror(line);
291 		dprintf("cannot create %s (%d)\n", LogName, errno);
292 		die(0);
293 	}
294 
295 	if (!SecureMode)
296 		finet = socket(AF_INET, SOCK_DGRAM, 0);
297 	else
298 		finet = -1;
299 
300 	inetm = 0;
301 	if (finet >= 0) {
302 		struct servent *sp;
303 
304 		sp = getservbyname("syslog", "udp");
305 		if (sp == NULL) {
306 			errno = 0;
307 			logerror("syslog/udp: unknown service");
308 			die(0);
309 		}
310 		memset(&sin, 0, sizeof(sin));
311 		sin.sin_family = AF_INET;
312 		sin.sin_port = LogPort = sp->s_port;
313 		if (bind(finet, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
314 			logerror("bind");
315 			if (!Debug)
316 				die(0);
317 		} else {
318 			inetm = FDMASK(finet);
319 			InetInuse = 1;
320 		}
321 	}
322 	if ((fklog = open(_PATH_KLOG, O_RDONLY, 0)) >= 0)
323 		klogm = FDMASK(fklog);
324 	else {
325 		dprintf("can't open %s (%d)\n", _PATH_KLOG, errno);
326 		klogm = 0;
327 	}
328 
329 	/* tuck my process id away, if i'm not in debug mode */
330 	if (Debug == 0) {
331 		fp = fopen(PidFile, "w");
332 		if (fp != NULL) {
333 			fprintf(fp, "%d\n", getpid());
334 			(void) fclose(fp);
335 		}
336 	}
337 
338 	dprintf("off & running....\n");
339 
340 	init(0);
341 	(void)signal(SIGHUP, init);
342 
343 	for (;;) {
344 		int nfds, readfds = FDMASK(funix) | inetm | klogm;
345 
346 		dprintf("readfds = %#x\n", readfds);
347 		nfds = select(20, (fd_set *)&readfds, (fd_set *)NULL,
348 		    (fd_set *)NULL, (struct timeval *)NULL);
349 		if (nfds == 0)
350 			continue;
351 		if (nfds < 0) {
352 			if (errno != EINTR)
353 				logerror("select");
354 			continue;
355 		}
356 		dprintf("got a message (%d, %#x)\n", nfds, readfds);
357 		if (readfds & klogm) {
358 			i = read(fklog, line, linesize - 1);
359 			if (i > 0) {
360 				line[i] = '\0';
361 				printsys(line);
362 			} else if (i < 0 && errno != EINTR) {
363 				logerror("klog");
364 				fklog = -1;
365 				klogm = 0;
366 			}
367 		}
368 		if (readfds & FDMASK(funix)) {
369 			len = sizeof(fromunix);
370 			i = recvfrom(funix, line, MAXLINE, 0,
371 			    (struct sockaddr *)&fromunix, &len);
372 			if (i > 0) {
373 				line[i] = '\0';
374 				printline(LocalHostName, line);
375 			} else if (i < 0 && errno != EINTR)
376 				logerror("recvfrom unix");
377 		}
378 		if (readfds & inetm) {
379 			len = sizeof(frominet);
380 			i = recvfrom(finet, line, MAXLINE, 0,
381 			    (struct sockaddr *)&frominet, &len);
382 			if (i > 0) {
383 				line[i] = '\0';
384 				printline(cvthname(&frominet), line);
385 			} else if (i < 0 && errno != EINTR)
386 				logerror("recvfrom inet");
387 		}
388 	}
389 }
390 
391 void
392 usage()
393 {
394 
395 	(void)fprintf(stderr,
396 	    "usage: syslogd [-f conffile] [-m markinterval] [-p logpath]\n");
397 	exit(1);
398 }
399 
400 /*
401  * Take a raw input line, decode the message, and print the message
402  * on the appropriate log files.
403  */
404 void
405 printline(hname, msg)
406 	char *hname;
407 	char *msg;
408 {
409 	int c, pri;
410 	char *p, *q, line[MAXLINE + 1];
411 
412 	/* test for special codes */
413 	pri = DEFUPRI;
414 	p = msg;
415 	if (*p == '<') {
416 		pri = 0;
417 		while (isdigit(*++p))
418 			pri = 10 * pri + (*p - '0');
419 		if (*p == '>')
420 			++p;
421 	}
422 	if (pri &~ (LOG_FACMASK|LOG_PRIMASK))
423 		pri = DEFUPRI;
424 
425 	/* don't allow users to log kernel messages */
426 	if (LOG_FAC(pri) == LOG_KERN)
427 		pri = LOG_MAKEPRI(LOG_USER, LOG_PRI(pri));
428 
429 	q = line;
430 
431 	while ((c = *p++ & 0177) != '\0' &&
432 	    q < &line[sizeof(line) - 1])
433 		if (iscntrl(c))
434 			if (c == '\n')
435 				*q++ = ' ';
436 			else if (c == '\t')
437 				*q++ = '\t';
438 			else {
439 				*q++ = '^';
440 				*q++ = c ^ 0100;
441 			}
442 		else
443 			*q++ = c;
444 	*q = '\0';
445 
446 	logmsg(pri, line, hname, 0);
447 }
448 
449 /*
450  * Take a raw input line from /dev/klog, split and format similar to syslog().
451  */
452 void
453 printsys(msg)
454 	char *msg;
455 {
456 	int c, pri, flags;
457 	char *lp, *p, *q, line[MAXLINE + 1];
458 
459 	(void)strcpy(line, _PATH_UNIX);
460 	(void)strcat(line, ": ");
461 	lp = line + strlen(line);
462 	for (p = msg; *p != '\0'; ) {
463 		flags = SYNC_FILE | ADDDATE;	/* fsync file after write */
464 		pri = DEFSPRI;
465 		if (*p == '<') {
466 			pri = 0;
467 			while (isdigit(*++p))
468 				pri = 10 * pri + (*p - '0');
469 			if (*p == '>')
470 				++p;
471 		} else {
472 			/* kernel printf's come out on console */
473 			flags |= IGN_CONS;
474 		}
475 		if (pri &~ (LOG_FACMASK|LOG_PRIMASK))
476 			pri = DEFSPRI;
477 		q = lp;
478 		while (*p != '\0' && (c = *p++) != '\n' &&
479 		    q < &line[MAXLINE])
480 			*q++ = c;
481 		*q = '\0';
482 		logmsg(pri, line, LocalHostName, flags);
483 	}
484 }
485 
486 time_t	now;
487 
488 /*
489  * Log a message to the appropriate log files, users, etc. based on
490  * the priority.
491  */
492 void
493 logmsg(pri, msg, from, flags)
494 	int pri;
495 	char *msg, *from;
496 	int flags;
497 {
498 	struct filed *f;
499 	int fac, msglen, omask, prilev;
500 	char *timestamp;
501 
502 	dprintf("logmsg: pri 0%o, flags 0x%x, from %s, msg %s\n",
503 	    pri, flags, from, msg);
504 
505 	omask = sigblock(sigmask(SIGHUP)|sigmask(SIGALRM));
506 
507 	/*
508 	 * Check to see if msg looks non-standard.
509 	 */
510 	msglen = strlen(msg);
511 	if (msglen < 16 || msg[3] != ' ' || msg[6] != ' ' ||
512 	    msg[9] != ':' || msg[12] != ':' || msg[15] != ' ')
513 		flags |= ADDDATE;
514 
515 	(void)time(&now);
516 	if (flags & ADDDATE)
517 		timestamp = ctime(&now) + 4;
518 	else {
519 		timestamp = msg;
520 		msg += 16;
521 		msglen -= 16;
522 	}
523 
524 	/* extract facility and priority level */
525 	if (flags & MARK)
526 		fac = LOG_NFACILITIES;
527 	else
528 		fac = LOG_FAC(pri);
529 	prilev = LOG_PRI(pri);
530 
531 	/* log the message to the particular outputs */
532 	if (!Initialized) {
533 		f = &consfile;
534 		f->f_file = open(ctty, O_WRONLY, 0);
535 
536 		if (f->f_file >= 0) {
537 			fprintlog(f, flags, msg);
538 			(void)close(f->f_file);
539 		}
540 		(void)sigsetmask(omask);
541 		return;
542 	}
543 	for (f = Files; f; f = f->f_next) {
544 		/* skip messages that are incorrect priority */
545 		if (f->f_pmask[fac] < prilev ||
546 		    f->f_pmask[fac] == INTERNAL_NOPRI)
547 			continue;
548 
549 		if (f->f_type == F_CONSOLE && (flags & IGN_CONS))
550 			continue;
551 
552 		/* don't output marks to recently written files */
553 		if ((flags & MARK) && (now - f->f_time) < MarkInterval / 2)
554 			continue;
555 
556 		/*
557 		 * suppress duplicate lines to this file
558 		 */
559 		if ((flags & MARK) == 0 && msglen == f->f_prevlen &&
560 		    !strcmp(msg, f->f_prevline) &&
561 		    !strcmp(from, f->f_prevhost)) {
562 			(void)strncpy(f->f_lasttime, timestamp, 15);
563 			f->f_prevcount++;
564 			dprintf("msg repeated %d times, %ld sec of %d\n",
565 			    f->f_prevcount, (long)(now - f->f_time),
566 			    repeatinterval[f->f_repeatcount]);
567 			/*
568 			 * If domark would have logged this by now,
569 			 * flush it now (so we don't hold isolated messages),
570 			 * but back off so we'll flush less often
571 			 * in the future.
572 			 */
573 			if (now > REPEATTIME(f)) {
574 				fprintlog(f, flags, (char *)NULL);
575 				BACKOFF(f);
576 			}
577 		} else {
578 			/* new line, save it */
579 			if (f->f_prevcount)
580 				fprintlog(f, 0, (char *)NULL);
581 			f->f_repeatcount = 0;
582 			f->f_prevpri = pri;
583 			(void)strncpy(f->f_lasttime, timestamp, 15);
584 			(void)strncpy(f->f_prevhost, from,
585 					sizeof(f->f_prevhost));
586 			if (msglen < MAXSVLINE) {
587 				f->f_prevlen = msglen;
588 				(void)strcpy(f->f_prevline, msg);
589 				fprintlog(f, flags, (char *)NULL);
590 			} else {
591 				f->f_prevline[0] = 0;
592 				f->f_prevlen = 0;
593 				fprintlog(f, flags, msg);
594 			}
595 		}
596 	}
597 	(void)sigsetmask(omask);
598 }
599 
600 void
601 fprintlog(f, flags, msg)
602 	struct filed *f;
603 	int flags;
604 	char *msg;
605 {
606 	struct iovec iov[6];
607 	struct iovec *v;
608 	int l;
609 	char line[MAXLINE + 1], repbuf[80], greetings[200];
610 
611 	v = iov;
612 	if (f->f_type == F_WALL) {
613 		v->iov_base = greetings;
614 		v->iov_len = snprintf(greetings, sizeof greetings,
615 		    "\r\n\7Message from syslogd@%s at %.24s ...\r\n",
616 		    f->f_prevhost, ctime(&now));
617 		v++;
618 		v->iov_base = "";
619 		v->iov_len = 0;
620 		v++;
621 	} else {
622 		v->iov_base = f->f_lasttime;
623 		v->iov_len = 15;
624 		v++;
625 		v->iov_base = " ";
626 		v->iov_len = 1;
627 		v++;
628 	}
629 	v->iov_base = f->f_prevhost;
630 	v->iov_len = strlen(v->iov_base);
631 	v++;
632 	v->iov_base = " ";
633 	v->iov_len = 1;
634 	v++;
635 
636 	if (msg) {
637 		v->iov_base = msg;
638 		v->iov_len = strlen(msg);
639 	} else if (f->f_prevcount > 1) {
640 		v->iov_base = repbuf;
641 		v->iov_len = snprintf(repbuf, sizeof repbuf,
642 		    "last message repeated %d times", f->f_prevcount);
643 	} else {
644 		v->iov_base = f->f_prevline;
645 		v->iov_len = f->f_prevlen;
646 	}
647 	v++;
648 
649 	dprintf("Logging to %s", TypeNames[f->f_type]);
650 	f->f_time = now;
651 
652 	switch (f->f_type) {
653 	case F_UNUSED:
654 		dprintf("\n");
655 		break;
656 
657 	case F_FORW:
658 		dprintf(" %s\n", f->f_un.f_forw.f_hname);
659 		l = snprintf(line, sizeof line, "<%d>%.15s %s", f->f_prevpri,
660 		    iov[0].iov_base, iov[4].iov_base);
661 		if (l > MAXLINE)
662 			l = MAXLINE;
663 		if ((finet >= 0) &&
664 		     (sendto(finet, line, l, 0,
665 			     (struct sockaddr *)&f->f_un.f_forw.f_addr,
666 			     sizeof(f->f_un.f_forw.f_addr)) != l)) {
667 			int e = errno;
668 			f->f_type = F_UNUSED;
669 			errno = e;
670 			logerror("sendto");
671 		}
672 		break;
673 
674 	case F_CONSOLE:
675 		if (flags & IGN_CONS) {
676 			dprintf(" (ignored)\n");
677 			break;
678 		}
679 		/* FALLTHROUGH */
680 
681 	case F_TTY:
682 	case F_FILE:
683 		dprintf(" %s\n", f->f_un.f_fname);
684 		if (f->f_type != F_FILE) {
685 			v->iov_base = "\r\n";
686 			v->iov_len = 2;
687 		} else {
688 			v->iov_base = "\n";
689 			v->iov_len = 1;
690 		}
691 	again:
692 		if (writev(f->f_file, iov, 6) < 0) {
693 			int e = errno;
694 			(void)close(f->f_file);
695 			/*
696 			 * Check for errors on TTY's due to loss of tty
697 			 */
698 			if ((e == EIO || e == EBADF) && f->f_type != F_FILE) {
699 				f->f_file = open(f->f_un.f_fname,
700 				    O_WRONLY|O_APPEND, 0);
701 				if (f->f_file < 0) {
702 					f->f_type = F_UNUSED;
703 					logerror(f->f_un.f_fname);
704 				} else
705 					goto again;
706 			} else {
707 				f->f_type = F_UNUSED;
708 				errno = e;
709 				logerror(f->f_un.f_fname);
710 			}
711 		} else if (flags & SYNC_FILE)
712 			(void)fsync(f->f_file);
713 		break;
714 
715 	case F_USERS:
716 	case F_WALL:
717 		dprintf("\n");
718 		v->iov_base = "\r\n";
719 		v->iov_len = 2;
720 		wallmsg(f, iov);
721 		break;
722 	}
723 	f->f_prevcount = 0;
724 }
725 
726 /*
727  *  WALLMSG -- Write a message to the world at large
728  *
729  *	Write the specified message to either the entire
730  *	world, or a list of approved users.
731  */
732 void
733 wallmsg(f, iov)
734 	struct filed *f;
735 	struct iovec *iov;
736 {
737 	static int reenter;			/* avoid calling ourselves */
738 	FILE *uf;
739 	struct utmp ut;
740 	int i;
741 	char *p;
742 	char line[sizeof(ut.ut_line) + 1];
743 
744 	if (reenter++)
745 		return;
746 	if ((uf = fopen(_PATH_UTMP, "r")) == NULL) {
747 		logerror(_PATH_UTMP);
748 		reenter = 0;
749 		return;
750 	}
751 	/* NOSTRICT */
752 	while (fread((char *)&ut, sizeof(ut), 1, uf) == 1) {
753 		if (ut.ut_name[0] == '\0')
754 			continue;
755 		strncpy(line, ut.ut_line, sizeof(ut.ut_line));
756 		line[sizeof(ut.ut_line)] = '\0';
757 		if (f->f_type == F_WALL) {
758 			if ((p = ttymsg(iov, 6, line, TTYMSGTIME)) != NULL) {
759 				errno = 0;	/* already in msg */
760 				logerror(p);
761 			}
762 			continue;
763 		}
764 		/* should we send the message to this user? */
765 		for (i = 0; i < MAXUNAMES; i++) {
766 			if (!f->f_un.f_uname[i][0])
767 				break;
768 			if (!strncmp(f->f_un.f_uname[i], ut.ut_name,
769 			    UT_NAMESIZE)) {
770 				if ((p = ttymsg(iov, 6, line, TTYMSGTIME))
771 								!= NULL) {
772 					errno = 0;	/* already in msg */
773 					logerror(p);
774 				}
775 				break;
776 			}
777 		}
778 	}
779 	(void)fclose(uf);
780 	reenter = 0;
781 }
782 
783 void
784 reapchild(signo)
785 	int signo;
786 {
787 	union wait status;
788 
789 	while (wait3((int *)&status, WNOHANG, (struct rusage *)NULL) > 0)
790 		;
791 }
792 
793 /*
794  * Return a printable representation of a host address.
795  */
796 char *
797 cvthname(f)
798 	struct sockaddr_in *f;
799 {
800 	struct hostent *hp;
801 	char *p;
802 
803 	dprintf("cvthname(%s)\n", inet_ntoa(f->sin_addr));
804 
805 	if (f->sin_family != AF_INET) {
806 		dprintf("Malformed from address\n");
807 		return ("???");
808 	}
809 	hp = gethostbyaddr((char *)&f->sin_addr,
810 	    sizeof(struct in_addr), f->sin_family);
811 	if (hp == 0) {
812 		dprintf("Host name for your address (%s) unknown\n",
813 			inet_ntoa(f->sin_addr));
814 		return (inet_ntoa(f->sin_addr));
815 	}
816 	if ((p = strchr(hp->h_name, '.')) && strcmp(p + 1, LocalDomain) == 0)
817 		*p = '\0';
818 	return (hp->h_name);
819 }
820 
821 void
822 domark(signo)
823 	int signo;
824 {
825 	struct filed *f;
826 
827 	now = time((time_t *)NULL);
828 	MarkSeq += TIMERINTVL;
829 	if (MarkSeq >= MarkInterval) {
830 		logmsg(LOG_INFO, "-- MARK --", LocalHostName, ADDDATE|MARK);
831 		MarkSeq = 0;
832 	}
833 
834 	for (f = Files; f; f = f->f_next) {
835 		if (f->f_prevcount && now >= REPEATTIME(f)) {
836 			dprintf("flush %s: repeated %d times, %d sec.\n",
837 			    TypeNames[f->f_type], f->f_prevcount,
838 			    repeatinterval[f->f_repeatcount]);
839 			fprintlog(f, 0, (char *)NULL);
840 			BACKOFF(f);
841 		}
842 	}
843 	(void)alarm(TIMERINTVL);
844 }
845 
846 /*
847  * Print syslogd errors some place.
848  */
849 void
850 logerror(type)
851 	char *type;
852 {
853 	char buf[100];
854 
855 	if (errno)
856 		(void)snprintf(buf,
857 		    sizeof(buf), "syslogd: %s: %s", type, strerror(errno));
858 	else
859 		(void)snprintf(buf, sizeof(buf), "syslogd: %s", type);
860 	errno = 0;
861 	dprintf("%s\n", buf);
862 	logmsg(LOG_SYSLOG|LOG_ERR, buf, LocalHostName, ADDDATE);
863 }
864 
865 void
866 die(signo)
867 	int signo;
868 {
869 	struct filed *f;
870 	char buf[100];
871 
872 	for (f = Files; f != NULL; f = f->f_next) {
873 		/* flush any pending output */
874 		if (f->f_prevcount)
875 			fprintlog(f, 0, (char *)NULL);
876 	}
877 	if (signo) {
878 		dprintf("syslogd: exiting on signal %d\n", signo);
879 		(void)snprintf(buf, sizeof buf, "exiting on signal %d", signo);
880 		errno = 0;
881 		logerror(buf);
882 	}
883 	(void)unlink(LogName);
884 	exit(0);
885 }
886 
887 /*
888  *  INIT -- Initialize syslogd from configuration table
889  */
890 void
891 init(signo)
892 	int signo;
893 {
894 	int i;
895 	FILE *cf;
896 	struct filed *f, *next, **nextp;
897 	char *p;
898 	char cline[LINE_MAX];
899 
900 	dprintf("init\n");
901 
902 	/*
903 	 *  Close all open log files.
904 	 */
905 	Initialized = 0;
906 	for (f = Files; f != NULL; f = next) {
907 		/* flush any pending output */
908 		if (f->f_prevcount)
909 			fprintlog(f, 0, (char *)NULL);
910 
911 		switch (f->f_type) {
912 		case F_FILE:
913 		case F_TTY:
914 		case F_CONSOLE:
915 			(void)close(f->f_file);
916 			break;
917 		}
918 		next = f->f_next;
919 		free((char *)f);
920 	}
921 	Files = NULL;
922 	nextp = &Files;
923 
924 	/* open the configuration file */
925 	if ((cf = fopen(ConfFile, "r")) == NULL) {
926 		dprintf("cannot open %s\n", ConfFile);
927 		*nextp = (struct filed *)calloc(1, sizeof(*f));
928 		cfline("*.ERR\t/dev/console", *nextp);
929 		(*nextp)->f_next = (struct filed *)calloc(1, sizeof(*f));
930 		cfline("*.PANIC\t*", (*nextp)->f_next);
931 		Initialized = 1;
932 		return;
933 	}
934 
935 	/*
936 	 *  Foreach line in the conf table, open that file.
937 	 */
938 	f = NULL;
939 	while (fgets(cline, sizeof(cline), cf) != NULL) {
940 		/*
941 		 * check for end-of-section, comments, strip off trailing
942 		 * spaces and newline character.
943 		 */
944 		for (p = cline; isspace(*p); ++p)
945 			continue;
946 		if (*p == '\0' || *p == '#')
947 			continue;
948 		for (p = strchr(cline, '\0'); isspace(*--p);)
949 			continue;
950 		*++p = '\0';
951 		f = (struct filed *)calloc(1, sizeof(*f));
952 		*nextp = f;
953 		nextp = &f->f_next;
954 		cfline(cline, f);
955 	}
956 
957 	/* close the configuration file */
958 	(void)fclose(cf);
959 
960 	Initialized = 1;
961 
962 	if (Debug) {
963 		for (f = Files; f; f = f->f_next) {
964 			for (i = 0; i <= LOG_NFACILITIES; i++)
965 				if (f->f_pmask[i] == INTERNAL_NOPRI)
966 					printf("X ");
967 				else
968 					printf("%d ", f->f_pmask[i]);
969 			printf("%s: ", TypeNames[f->f_type]);
970 			switch (f->f_type) {
971 			case F_FILE:
972 			case F_TTY:
973 			case F_CONSOLE:
974 				printf("%s", f->f_un.f_fname);
975 				break;
976 
977 			case F_FORW:
978 				printf("%s", f->f_un.f_forw.f_hname);
979 				break;
980 
981 			case F_USERS:
982 				for (i = 0; i < MAXUNAMES && *f->f_un.f_uname[i]; i++)
983 					printf("%s, ", f->f_un.f_uname[i]);
984 				break;
985 			}
986 			printf("\n");
987 		}
988 	}
989 
990 	logmsg(LOG_SYSLOG|LOG_INFO, "syslogd: restart", LocalHostName, ADDDATE);
991 	dprintf("syslogd: restarted\n");
992 }
993 
994 /*
995  * Crack a configuration file line
996  */
997 void
998 cfline(line, f)
999 	char *line;
1000 	struct filed *f;
1001 {
1002 	struct hostent *hp;
1003 	int i, pri;
1004 	char *bp, *p, *q;
1005 	char buf[MAXLINE], ebuf[100];
1006 
1007 	dprintf("cfline(%s)\n", line);
1008 
1009 	errno = 0;	/* keep strerror() stuff out of logerror messages */
1010 
1011 	/* clear out file entry */
1012 	memset(f, 0, sizeof(*f));
1013 	for (i = 0; i <= LOG_NFACILITIES; i++)
1014 		f->f_pmask[i] = INTERNAL_NOPRI;
1015 
1016 	/* scan through the list of selectors */
1017 	for (p = line; *p && *p != '\t';) {
1018 
1019 		/* find the end of this facility name list */
1020 		for (q = p; *q && *q != '\t' && *q++ != '.'; )
1021 			continue;
1022 
1023 		/* collect priority name */
1024 		for (bp = buf; *q && !strchr("\t,;", *q); )
1025 			*bp++ = *q++;
1026 		*bp = '\0';
1027 
1028 		/* skip cruft */
1029 		while (strchr(", ;", *q))
1030 			q++;
1031 
1032 		/* decode priority name */
1033 		if (*buf == '*')
1034 			pri = LOG_PRIMASK + 1;
1035 		else {
1036 			pri = decode(buf, prioritynames);
1037 			if (pri < 0) {
1038 				(void)snprintf(ebuf, sizeof ebuf,
1039 				    "unknown priority name \"%s\"", buf);
1040 				logerror(ebuf);
1041 				return;
1042 			}
1043 		}
1044 
1045 		/* scan facilities */
1046 		while (*p && !strchr("\t.;", *p)) {
1047 			for (bp = buf; *p && !strchr("\t,;.", *p); )
1048 				*bp++ = *p++;
1049 			*bp = '\0';
1050 			if (*buf == '*')
1051 				for (i = 0; i < LOG_NFACILITIES; i++)
1052 					f->f_pmask[i] = pri;
1053 			else {
1054 				i = decode(buf, facilitynames);
1055 				if (i < 0) {
1056 					(void)snprintf(ebuf, sizeof ebuf,
1057 					    "unknown facility name \"%s\"",
1058 					    buf);
1059 					logerror(ebuf);
1060 					return;
1061 				}
1062 				f->f_pmask[i >> 3] = pri;
1063 			}
1064 			while (*p == ',' || *p == ' ')
1065 				p++;
1066 		}
1067 
1068 		p = q;
1069 	}
1070 
1071 	/* skip to action part */
1072 	while (*p == '\t')
1073 		p++;
1074 
1075 	switch (*p)
1076 	{
1077 	case '@':
1078 		if (!InetInuse)
1079 			break;
1080 		(void)strcpy(f->f_un.f_forw.f_hname, ++p);
1081 		hp = gethostbyname(p);
1082 		if (hp == NULL) {
1083 			extern int h_errno;
1084 
1085 			logerror((char *)hstrerror(h_errno));
1086 			break;
1087 		}
1088 		memset(&f->f_un.f_forw.f_addr, 0,
1089 			 sizeof(f->f_un.f_forw.f_addr));
1090 		f->f_un.f_forw.f_addr.sin_family = AF_INET;
1091 		f->f_un.f_forw.f_addr.sin_port = LogPort;
1092 		memmove(&f->f_un.f_forw.f_addr.sin_addr, hp->h_addr, hp->h_length);
1093 		f->f_type = F_FORW;
1094 		break;
1095 
1096 	case '/':
1097 		(void)strcpy(f->f_un.f_fname, p);
1098 		if ((f->f_file = open(p, O_WRONLY|O_APPEND, 0)) < 0) {
1099 			f->f_type = F_UNUSED;
1100 			logerror(p);
1101 			break;
1102 		}
1103 		if (isatty(f->f_file))
1104 			f->f_type = F_TTY;
1105 		else
1106 			f->f_type = F_FILE;
1107 		if (strcmp(p, ctty) == 0)
1108 			f->f_type = F_CONSOLE;
1109 		break;
1110 
1111 	case '*':
1112 		f->f_type = F_WALL;
1113 		break;
1114 
1115 	default:
1116 		for (i = 0; i < MAXUNAMES && *p; i++) {
1117 			for (q = p; *q && *q != ','; )
1118 				q++;
1119 			(void)strncpy(f->f_un.f_uname[i], p, UT_NAMESIZE);
1120 			if ((q - p) > UT_NAMESIZE)
1121 				f->f_un.f_uname[i][UT_NAMESIZE] = '\0';
1122 			else
1123 				f->f_un.f_uname[i][q - p] = '\0';
1124 			while (*q == ',' || *q == ' ')
1125 				q++;
1126 			p = q;
1127 		}
1128 		f->f_type = F_USERS;
1129 		break;
1130 	}
1131 }
1132 
1133 
1134 /*
1135  *  Decode a symbolic name to a numeric value
1136  */
1137 int
1138 decode(name, codetab)
1139 	const char *name;
1140 	CODE *codetab;
1141 {
1142 	CODE *c;
1143 	char *p, buf[40];
1144 
1145 	if (isdigit(*name))
1146 		return (atoi(name));
1147 
1148 	for (p = buf; *name && p < &buf[sizeof(buf) - 1]; p++, name++) {
1149 		if (isupper(*name))
1150 			*p = tolower(*name);
1151 		else
1152 			*p = *name;
1153 	}
1154 	*p = '\0';
1155 	for (c = codetab; c->c_name; c++)
1156 		if (!strcmp(buf, c->c_name))
1157 			return (c->c_val);
1158 
1159 	return (-1);
1160 }
1161 
1162 /*
1163  * Retrieve the size of the kernel message buffer, via sysctl.
1164  */
1165 int
1166 getmsgbufsize()
1167 {
1168 	int msgbufsize, mib[2];
1169 	size_t size;
1170 
1171 	mib[0] = CTL_KERN;
1172 	mib[1] = KERN_MSGBUFSIZE;
1173 	size = sizeof msgbufsize;
1174 	if (sysctl(mib, 2, &msgbufsize, &size, NULL, 0) == -1) {
1175 		dprintf("couldn't get kern.msgbufsize\n");
1176 		return (0);
1177 	}
1178 	return (msgbufsize);
1179 }
1180