xref: /netbsd-src/usr.sbin/syslogd/syslogd.c (revision dc306354b0b29af51801a7632f1e95265a68cd81)
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 1.21 1998/07/30 23:29:29 tron 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 	LocalHostName[sizeof(LocalHostName) - 1] = '\0';
258 	if ((p = strchr(LocalHostName, '.')) != NULL) {
259 		*p++ = '\0';
260 		LocalDomain = p;
261 	} else
262 		LocalDomain = "";
263 	linesize = getmsgbufsize();
264 	if (linesize < MAXLINE)
265 		linesize = MAXLINE;
266 	linesize++;
267 	line = malloc(linesize);
268 	if (line == NULL) {
269 		logerror("couldn't allocate line buffer");
270 		die(0);
271 	}
272 	(void)signal(SIGTERM, die);
273 	(void)signal(SIGINT, Debug ? die : SIG_IGN);
274 	(void)signal(SIGQUIT, Debug ? die : SIG_IGN);
275 	(void)signal(SIGCHLD, reapchild);
276 	(void)signal(SIGALRM, domark);
277 	(void)alarm(TIMERINTVL);
278 	(void)unlink(LogName);
279 
280 #ifndef SUN_LEN
281 #define SUN_LEN(unp) (strlen((unp)->sun_path) + 2)
282 #endif
283 	memset(&sunx, 0, sizeof(sunx));
284 	sunx.sun_family = AF_LOCAL;
285 	(void)strncpy(sunx.sun_path, LogName, sizeof(sunx.sun_path));
286 	funix = socket(AF_LOCAL, SOCK_DGRAM, 0);
287 	if (funix < 0 ||
288 	    bind(funix, (struct sockaddr *)&sunx, SUN_LEN(&sunx)) < 0 ||
289 	    chmod(LogName, 0666) < 0) {
290 		(void)snprintf(line, sizeof line, "cannot create %s", LogName);
291 		logerror(line);
292 		dprintf("cannot create %s (%d)\n", LogName, errno);
293 		die(0);
294 	}
295 
296 	if (!SecureMode)
297 		finet = socket(AF_INET, SOCK_DGRAM, 0);
298 	else
299 		finet = -1;
300 
301 	inetm = 0;
302 	if (finet >= 0) {
303 		struct servent *sp;
304 
305 		sp = getservbyname("syslog", "udp");
306 		if (sp == NULL) {
307 			errno = 0;
308 			logerror("syslog/udp: unknown service");
309 			die(0);
310 		}
311 		memset(&sin, 0, sizeof(sin));
312 		sin.sin_family = AF_INET;
313 		sin.sin_port = LogPort = sp->s_port;
314 		if (bind(finet, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
315 			logerror("bind");
316 			if (!Debug)
317 				die(0);
318 		} else {
319 			inetm = FDMASK(finet);
320 			InetInuse = 1;
321 		}
322 	}
323 	if ((fklog = open(_PATH_KLOG, O_RDONLY, 0)) >= 0)
324 		klogm = FDMASK(fklog);
325 	else {
326 		dprintf("can't open %s (%d)\n", _PATH_KLOG, errno);
327 		klogm = 0;
328 	}
329 
330 	/* tuck my process id away, if i'm not in debug mode */
331 	if (Debug == 0) {
332 		fp = fopen(PidFile, "w");
333 		if (fp != NULL) {
334 			fprintf(fp, "%d\n", getpid());
335 			(void) fclose(fp);
336 		}
337 	}
338 
339 	dprintf("off & running....\n");
340 
341 	init(0);
342 	(void)signal(SIGHUP, init);
343 
344 	for (;;) {
345 		int nfds, readfds = FDMASK(funix) | inetm | klogm;
346 
347 		dprintf("readfds = %#x\n", readfds);
348 		nfds = select(20, (fd_set *)&readfds, (fd_set *)NULL,
349 		    (fd_set *)NULL, (struct timeval *)NULL);
350 		if (nfds == 0)
351 			continue;
352 		if (nfds < 0) {
353 			if (errno != EINTR)
354 				logerror("select");
355 			continue;
356 		}
357 		dprintf("got a message (%d, %#x)\n", nfds, readfds);
358 		if (readfds & klogm) {
359 			i = read(fklog, line, linesize - 1);
360 			if (i > 0) {
361 				line[i] = '\0';
362 				printsys(line);
363 			} else if (i < 0 && errno != EINTR) {
364 				logerror("klog");
365 				fklog = -1;
366 				klogm = 0;
367 			}
368 		}
369 		if (readfds & FDMASK(funix)) {
370 			len = sizeof(fromunix);
371 			i = recvfrom(funix, line, MAXLINE, 0,
372 			    (struct sockaddr *)&fromunix, &len);
373 			if (i > 0) {
374 				line[i] = '\0';
375 				printline(LocalHostName, line);
376 			} else if (i < 0 && errno != EINTR)
377 				logerror("recvfrom unix");
378 		}
379 		if (readfds & inetm) {
380 			len = sizeof(frominet);
381 			i = recvfrom(finet, line, MAXLINE, 0,
382 			    (struct sockaddr *)&frominet, &len);
383 			if (i > 0) {
384 				line[i] = '\0';
385 				printline(cvthname(&frominet), line);
386 			} else if (i < 0 && errno != EINTR)
387 				logerror("recvfrom inet");
388 		}
389 	}
390 }
391 
392 void
393 usage()
394 {
395 
396 	(void)fprintf(stderr,
397 	    "usage: syslogd [-f conffile] [-m markinterval] [-p logpath]\n");
398 	exit(1);
399 }
400 
401 /*
402  * Take a raw input line, decode the message, and print the message
403  * on the appropriate log files.
404  */
405 void
406 printline(hname, msg)
407 	char *hname;
408 	char *msg;
409 {
410 	int c, pri;
411 	char *p, *q, line[MAXLINE + 1];
412 
413 	/* test for special codes */
414 	pri = DEFUPRI;
415 	p = msg;
416 	if (*p == '<') {
417 		pri = 0;
418 		while (isdigit(*++p))
419 			pri = 10 * pri + (*p - '0');
420 		if (*p == '>')
421 			++p;
422 	}
423 	if (pri &~ (LOG_FACMASK|LOG_PRIMASK))
424 		pri = DEFUPRI;
425 
426 	/* don't allow users to log kernel messages */
427 	if (LOG_FAC(pri) == LOG_KERN)
428 		pri = LOG_MAKEPRI(LOG_USER, LOG_PRI(pri));
429 
430 	q = line;
431 
432 	while ((c = *p++ & 0177) != '\0' &&
433 	    q < &line[sizeof(line) - 1])
434 		if (iscntrl(c))
435 			if (c == '\n')
436 				*q++ = ' ';
437 			else if (c == '\t')
438 				*q++ = '\t';
439 			else {
440 				*q++ = '^';
441 				*q++ = c ^ 0100;
442 			}
443 		else
444 			*q++ = c;
445 	*q = '\0';
446 
447 	logmsg(pri, line, hname, 0);
448 }
449 
450 /*
451  * Take a raw input line from /dev/klog, split and format similar to syslog().
452  */
453 void
454 printsys(msg)
455 	char *msg;
456 {
457 	int c, pri, flags;
458 	char *lp, *p, *q, line[MAXLINE + 1];
459 
460 	(void)strcpy(line, _PATH_UNIX);
461 	(void)strcat(line, ": ");
462 	lp = line + strlen(line);
463 	for (p = msg; *p != '\0'; ) {
464 		flags = SYNC_FILE | ADDDATE;	/* fsync file after write */
465 		pri = DEFSPRI;
466 		if (*p == '<') {
467 			pri = 0;
468 			while (isdigit(*++p))
469 				pri = 10 * pri + (*p - '0');
470 			if (*p == '>')
471 				++p;
472 		} else {
473 			/* kernel printf's come out on console */
474 			flags |= IGN_CONS;
475 		}
476 		if (pri &~ (LOG_FACMASK|LOG_PRIMASK))
477 			pri = DEFSPRI;
478 		q = lp;
479 		while (*p != '\0' && (c = *p++) != '\n' &&
480 		    q < &line[MAXLINE])
481 			*q++ = c;
482 		*q = '\0';
483 		logmsg(pri, line, LocalHostName, flags);
484 	}
485 }
486 
487 time_t	now;
488 
489 /*
490  * Log a message to the appropriate log files, users, etc. based on
491  * the priority.
492  */
493 void
494 logmsg(pri, msg, from, flags)
495 	int pri;
496 	char *msg, *from;
497 	int flags;
498 {
499 	struct filed *f;
500 	int fac, msglen, omask, prilev;
501 	char *timestamp;
502 
503 	dprintf("logmsg: pri 0%o, flags 0x%x, from %s, msg %s\n",
504 	    pri, flags, from, msg);
505 
506 	omask = sigblock(sigmask(SIGHUP)|sigmask(SIGALRM));
507 
508 	/*
509 	 * Check to see if msg looks non-standard.
510 	 */
511 	msglen = strlen(msg);
512 	if (msglen < 16 || msg[3] != ' ' || msg[6] != ' ' ||
513 	    msg[9] != ':' || msg[12] != ':' || msg[15] != ' ')
514 		flags |= ADDDATE;
515 
516 	(void)time(&now);
517 	if (flags & ADDDATE)
518 		timestamp = ctime(&now) + 4;
519 	else {
520 		timestamp = msg;
521 		msg += 16;
522 		msglen -= 16;
523 	}
524 
525 	/* extract facility and priority level */
526 	if (flags & MARK)
527 		fac = LOG_NFACILITIES;
528 	else
529 		fac = LOG_FAC(pri);
530 	prilev = LOG_PRI(pri);
531 
532 	/* log the message to the particular outputs */
533 	if (!Initialized) {
534 		f = &consfile;
535 		f->f_file = open(ctty, O_WRONLY, 0);
536 
537 		if (f->f_file >= 0) {
538 			fprintlog(f, flags, msg);
539 			(void)close(f->f_file);
540 		}
541 		(void)sigsetmask(omask);
542 		return;
543 	}
544 	for (f = Files; f; f = f->f_next) {
545 		/* skip messages that are incorrect priority */
546 		if (f->f_pmask[fac] < prilev ||
547 		    f->f_pmask[fac] == INTERNAL_NOPRI)
548 			continue;
549 
550 		if (f->f_type == F_CONSOLE && (flags & IGN_CONS))
551 			continue;
552 
553 		/* don't output marks to recently written files */
554 		if ((flags & MARK) && (now - f->f_time) < MarkInterval / 2)
555 			continue;
556 
557 		/*
558 		 * suppress duplicate lines to this file
559 		 */
560 		if ((flags & MARK) == 0 && msglen == f->f_prevlen &&
561 		    !strcmp(msg, f->f_prevline) &&
562 		    !strcmp(from, f->f_prevhost)) {
563 			(void)strncpy(f->f_lasttime, timestamp, 15);
564 			f->f_prevcount++;
565 			dprintf("msg repeated %d times, %ld sec of %d\n",
566 			    f->f_prevcount, (long)(now - f->f_time),
567 			    repeatinterval[f->f_repeatcount]);
568 			/*
569 			 * If domark would have logged this by now,
570 			 * flush it now (so we don't hold isolated messages),
571 			 * but back off so we'll flush less often
572 			 * in the future.
573 			 */
574 			if (now > REPEATTIME(f)) {
575 				fprintlog(f, flags, (char *)NULL);
576 				BACKOFF(f);
577 			}
578 		} else {
579 			/* new line, save it */
580 			if (f->f_prevcount)
581 				fprintlog(f, 0, (char *)NULL);
582 			f->f_repeatcount = 0;
583 			f->f_prevpri = pri;
584 			(void)strncpy(f->f_lasttime, timestamp, 15);
585 			(void)strncpy(f->f_prevhost, from,
586 					sizeof(f->f_prevhost));
587 			if (msglen < MAXSVLINE) {
588 				f->f_prevlen = msglen;
589 				(void)strcpy(f->f_prevline, msg);
590 				fprintlog(f, flags, (char *)NULL);
591 			} else {
592 				f->f_prevline[0] = 0;
593 				f->f_prevlen = 0;
594 				fprintlog(f, flags, msg);
595 			}
596 		}
597 	}
598 	(void)sigsetmask(omask);
599 }
600 
601 void
602 fprintlog(f, flags, msg)
603 	struct filed *f;
604 	int flags;
605 	char *msg;
606 {
607 	struct iovec iov[6];
608 	struct iovec *v;
609 	int l;
610 	char line[MAXLINE + 1], repbuf[80], greetings[200];
611 
612 	v = iov;
613 	if (f->f_type == F_WALL) {
614 		v->iov_base = greetings;
615 		v->iov_len = snprintf(greetings, sizeof greetings,
616 		    "\r\n\7Message from syslogd@%s at %.24s ...\r\n",
617 		    f->f_prevhost, ctime(&now));
618 		v++;
619 		v->iov_base = "";
620 		v->iov_len = 0;
621 		v++;
622 	} else {
623 		v->iov_base = f->f_lasttime;
624 		v->iov_len = 15;
625 		v++;
626 		v->iov_base = " ";
627 		v->iov_len = 1;
628 		v++;
629 	}
630 	v->iov_base = f->f_prevhost;
631 	v->iov_len = strlen(v->iov_base);
632 	v++;
633 	v->iov_base = " ";
634 	v->iov_len = 1;
635 	v++;
636 
637 	if (msg) {
638 		v->iov_base = msg;
639 		v->iov_len = strlen(msg);
640 	} else if (f->f_prevcount > 1) {
641 		v->iov_base = repbuf;
642 		v->iov_len = snprintf(repbuf, sizeof repbuf,
643 		    "last message repeated %d times", f->f_prevcount);
644 	} else {
645 		v->iov_base = f->f_prevline;
646 		v->iov_len = f->f_prevlen;
647 	}
648 	v++;
649 
650 	dprintf("Logging to %s", TypeNames[f->f_type]);
651 	f->f_time = now;
652 
653 	switch (f->f_type) {
654 	case F_UNUSED:
655 		dprintf("\n");
656 		break;
657 
658 	case F_FORW:
659 		dprintf(" %s\n", f->f_un.f_forw.f_hname);
660 		/* check for local vs remote messages (from FreeBSD PR#bin/7055) */
661 		if (strcmp(f->f_prevhost, LocalHostName)) {
662 			l = snprintf(line, sizeof(line) - 1,
663 				     "<%d>%.15s [%s]: %s",
664 				     f->f_prevpri, (char *) iov[0].iov_base,
665 				     f->f_prevhost, (char *) iov[4].iov_base);
666 		} else {
667 			l = snprintf(line, sizeof(line) - 1, "<%d>%.15s %s",
668 				     f->f_prevpri, (char *) iov[0].iov_base,
669 				     (char *) iov[4].iov_base);
670 		}
671 		if (l > MAXLINE)
672 			l = MAXLINE;
673 		if ((finet >= 0) &&
674 		     (sendto(finet, line, l, 0,
675 			     (struct sockaddr *)&f->f_un.f_forw.f_addr,
676 			     sizeof(f->f_un.f_forw.f_addr)) != l)) {
677 			int e = errno;
678 			f->f_type = F_UNUSED;
679 			errno = e;
680 			logerror("sendto");
681 		}
682 		break;
683 
684 	case F_CONSOLE:
685 		if (flags & IGN_CONS) {
686 			dprintf(" (ignored)\n");
687 			break;
688 		}
689 		/* FALLTHROUGH */
690 
691 	case F_TTY:
692 	case F_FILE:
693 		dprintf(" %s\n", f->f_un.f_fname);
694 		if (f->f_type != F_FILE) {
695 			v->iov_base = "\r\n";
696 			v->iov_len = 2;
697 		} else {
698 			v->iov_base = "\n";
699 			v->iov_len = 1;
700 		}
701 	again:
702 		if (writev(f->f_file, iov, 6) < 0) {
703 			int e = errno;
704 			(void)close(f->f_file);
705 			/*
706 			 * Check for errors on TTY's due to loss of tty
707 			 */
708 			if ((e == EIO || e == EBADF) && f->f_type != F_FILE) {
709 				f->f_file = open(f->f_un.f_fname,
710 				    O_WRONLY|O_APPEND, 0);
711 				if (f->f_file < 0) {
712 					f->f_type = F_UNUSED;
713 					logerror(f->f_un.f_fname);
714 				} else
715 					goto again;
716 			} else {
717 				f->f_type = F_UNUSED;
718 				errno = e;
719 				logerror(f->f_un.f_fname);
720 			}
721 		} else if (flags & SYNC_FILE)
722 			(void)fsync(f->f_file);
723 		break;
724 
725 	case F_USERS:
726 	case F_WALL:
727 		dprintf("\n");
728 		v->iov_base = "\r\n";
729 		v->iov_len = 2;
730 		wallmsg(f, iov);
731 		break;
732 	}
733 	f->f_prevcount = 0;
734 }
735 
736 /*
737  *  WALLMSG -- Write a message to the world at large
738  *
739  *	Write the specified message to either the entire
740  *	world, or a list of approved users.
741  */
742 void
743 wallmsg(f, iov)
744 	struct filed *f;
745 	struct iovec *iov;
746 {
747 	static int reenter;			/* avoid calling ourselves */
748 	FILE *uf;
749 	struct utmp ut;
750 	int i;
751 	char *p;
752 	char line[sizeof(ut.ut_line) + 1];
753 
754 	if (reenter++)
755 		return;
756 	if ((uf = fopen(_PATH_UTMP, "r")) == NULL) {
757 		logerror(_PATH_UTMP);
758 		reenter = 0;
759 		return;
760 	}
761 	/* NOSTRICT */
762 	while (fread((char *)&ut, sizeof(ut), 1, uf) == 1) {
763 		if (ut.ut_name[0] == '\0')
764 			continue;
765 		strncpy(line, ut.ut_line, sizeof(ut.ut_line));
766 		line[sizeof(ut.ut_line)] = '\0';
767 		if (f->f_type == F_WALL) {
768 			if ((p = ttymsg(iov, 6, line, TTYMSGTIME)) != NULL) {
769 				errno = 0;	/* already in msg */
770 				logerror(p);
771 			}
772 			continue;
773 		}
774 		/* should we send the message to this user? */
775 		for (i = 0; i < MAXUNAMES; i++) {
776 			if (!f->f_un.f_uname[i][0])
777 				break;
778 			if (!strncmp(f->f_un.f_uname[i], ut.ut_name,
779 			    UT_NAMESIZE)) {
780 				if ((p = ttymsg(iov, 6, line, TTYMSGTIME))
781 								!= NULL) {
782 					errno = 0;	/* already in msg */
783 					logerror(p);
784 				}
785 				break;
786 			}
787 		}
788 	}
789 	(void)fclose(uf);
790 	reenter = 0;
791 }
792 
793 void
794 reapchild(signo)
795 	int signo;
796 {
797 	union wait status;
798 
799 	while (wait3((int *)&status, WNOHANG, (struct rusage *)NULL) > 0)
800 		;
801 }
802 
803 /*
804  * Return a printable representation of a host address.
805  */
806 char *
807 cvthname(f)
808 	struct sockaddr_in *f;
809 {
810 	struct hostent *hp;
811 	char *p;
812 
813 	dprintf("cvthname(%s)\n", inet_ntoa(f->sin_addr));
814 
815 	if (f->sin_family != AF_INET) {
816 		dprintf("Malformed from address\n");
817 		return ("???");
818 	}
819 	hp = gethostbyaddr((char *)&f->sin_addr,
820 	    sizeof(struct in_addr), f->sin_family);
821 	if (hp == 0) {
822 		dprintf("Host name for your address (%s) unknown\n",
823 			inet_ntoa(f->sin_addr));
824 		return (inet_ntoa(f->sin_addr));
825 	}
826 	if ((p = strchr(hp->h_name, '.')) && strcmp(p + 1, LocalDomain) == 0)
827 		*p = '\0';
828 	return (hp->h_name);
829 }
830 
831 void
832 domark(signo)
833 	int signo;
834 {
835 	struct filed *f;
836 
837 	now = time((time_t *)NULL);
838 	MarkSeq += TIMERINTVL;
839 	if (MarkSeq >= MarkInterval) {
840 		logmsg(LOG_INFO, "-- MARK --", LocalHostName, ADDDATE|MARK);
841 		MarkSeq = 0;
842 	}
843 
844 	for (f = Files; f; f = f->f_next) {
845 		if (f->f_prevcount && now >= REPEATTIME(f)) {
846 			dprintf("flush %s: repeated %d times, %d sec.\n",
847 			    TypeNames[f->f_type], f->f_prevcount,
848 			    repeatinterval[f->f_repeatcount]);
849 			fprintlog(f, 0, (char *)NULL);
850 			BACKOFF(f);
851 		}
852 	}
853 	(void)alarm(TIMERINTVL);
854 }
855 
856 /*
857  * Print syslogd errors some place.
858  */
859 void
860 logerror(type)
861 	char *type;
862 {
863 	char buf[100];
864 
865 	if (errno)
866 		(void)snprintf(buf,
867 		    sizeof(buf), "syslogd: %s: %s", type, strerror(errno));
868 	else
869 		(void)snprintf(buf, sizeof(buf), "syslogd: %s", type);
870 	errno = 0;
871 	dprintf("%s\n", buf);
872 	logmsg(LOG_SYSLOG|LOG_ERR, buf, LocalHostName, ADDDATE);
873 }
874 
875 void
876 die(signo)
877 	int signo;
878 {
879 	struct filed *f;
880 	char buf[100];
881 
882 	for (f = Files; f != NULL; f = f->f_next) {
883 		/* flush any pending output */
884 		if (f->f_prevcount)
885 			fprintlog(f, 0, (char *)NULL);
886 	}
887 	if (signo) {
888 		dprintf("syslogd: exiting on signal %d\n", signo);
889 		(void)snprintf(buf, sizeof buf, "exiting on signal %d", signo);
890 		errno = 0;
891 		logerror(buf);
892 	}
893 	(void)unlink(LogName);
894 	exit(0);
895 }
896 
897 /*
898  *  INIT -- Initialize syslogd from configuration table
899  */
900 void
901 init(signo)
902 	int signo;
903 {
904 	int i;
905 	FILE *cf;
906 	struct filed *f, *next, **nextp;
907 	char *p;
908 	char cline[LINE_MAX];
909 
910 	dprintf("init\n");
911 
912 	/*
913 	 *  Close all open log files.
914 	 */
915 	Initialized = 0;
916 	for (f = Files; f != NULL; f = next) {
917 		/* flush any pending output */
918 		if (f->f_prevcount)
919 			fprintlog(f, 0, (char *)NULL);
920 
921 		switch (f->f_type) {
922 		case F_FILE:
923 		case F_TTY:
924 		case F_CONSOLE:
925 			(void)close(f->f_file);
926 			break;
927 		}
928 		next = f->f_next;
929 		free((char *)f);
930 	}
931 	Files = NULL;
932 	nextp = &Files;
933 
934 	/* open the configuration file */
935 	if ((cf = fopen(ConfFile, "r")) == NULL) {
936 		dprintf("cannot open %s\n", ConfFile);
937 		*nextp = (struct filed *)calloc(1, sizeof(*f));
938 		cfline("*.ERR\t/dev/console", *nextp);
939 		(*nextp)->f_next = (struct filed *)calloc(1, sizeof(*f));
940 		cfline("*.PANIC\t*", (*nextp)->f_next);
941 		Initialized = 1;
942 		return;
943 	}
944 
945 	/*
946 	 *  Foreach line in the conf table, open that file.
947 	 */
948 	f = NULL;
949 	while (fgets(cline, sizeof(cline), cf) != NULL) {
950 		/*
951 		 * check for end-of-section, comments, strip off trailing
952 		 * spaces and newline character.
953 		 */
954 		for (p = cline; isspace(*p); ++p)
955 			continue;
956 		if (*p == '\0' || *p == '#')
957 			continue;
958 		for (p = strchr(cline, '\0'); isspace(*--p);)
959 			continue;
960 		*++p = '\0';
961 		f = (struct filed *)calloc(1, sizeof(*f));
962 		*nextp = f;
963 		nextp = &f->f_next;
964 		cfline(cline, f);
965 	}
966 
967 	/* close the configuration file */
968 	(void)fclose(cf);
969 
970 	Initialized = 1;
971 
972 	if (Debug) {
973 		for (f = Files; f; f = f->f_next) {
974 			for (i = 0; i <= LOG_NFACILITIES; i++)
975 				if (f->f_pmask[i] == INTERNAL_NOPRI)
976 					printf("X ");
977 				else
978 					printf("%d ", f->f_pmask[i]);
979 			printf("%s: ", TypeNames[f->f_type]);
980 			switch (f->f_type) {
981 			case F_FILE:
982 			case F_TTY:
983 			case F_CONSOLE:
984 				printf("%s", f->f_un.f_fname);
985 				break;
986 
987 			case F_FORW:
988 				printf("%s", f->f_un.f_forw.f_hname);
989 				break;
990 
991 			case F_USERS:
992 				for (i = 0; i < MAXUNAMES && *f->f_un.f_uname[i]; i++)
993 					printf("%s, ", f->f_un.f_uname[i]);
994 				break;
995 			}
996 			printf("\n");
997 		}
998 	}
999 
1000 	logmsg(LOG_SYSLOG|LOG_INFO, "syslogd: restart", LocalHostName, ADDDATE);
1001 	dprintf("syslogd: restarted\n");
1002 }
1003 
1004 /*
1005  * Crack a configuration file line
1006  */
1007 void
1008 cfline(line, f)
1009 	char *line;
1010 	struct filed *f;
1011 {
1012 	struct hostent *hp;
1013 	int i, pri;
1014 	char *bp, *p, *q;
1015 	char buf[MAXLINE], ebuf[100];
1016 
1017 	dprintf("cfline(%s)\n", line);
1018 
1019 	errno = 0;	/* keep strerror() stuff out of logerror messages */
1020 
1021 	/* clear out file entry */
1022 	memset(f, 0, sizeof(*f));
1023 	for (i = 0; i <= LOG_NFACILITIES; i++)
1024 		f->f_pmask[i] = INTERNAL_NOPRI;
1025 
1026 	/* scan through the list of selectors */
1027 	for (p = line; *p && *p != '\t';) {
1028 
1029 		/* find the end of this facility name list */
1030 		for (q = p; *q && *q != '\t' && *q++ != '.'; )
1031 			continue;
1032 
1033 		/* collect priority name */
1034 		for (bp = buf; *q && !strchr("\t,;", *q); )
1035 			*bp++ = *q++;
1036 		*bp = '\0';
1037 
1038 		/* skip cruft */
1039 		while (strchr(", ;", *q))
1040 			q++;
1041 
1042 		/* decode priority name */
1043 		if (*buf == '*')
1044 			pri = LOG_PRIMASK + 1;
1045 		else {
1046 			pri = decode(buf, prioritynames);
1047 			if (pri < 0) {
1048 				(void)snprintf(ebuf, sizeof ebuf,
1049 				    "unknown priority name \"%s\"", buf);
1050 				logerror(ebuf);
1051 				return;
1052 			}
1053 		}
1054 
1055 		/* scan facilities */
1056 		while (*p && !strchr("\t.;", *p)) {
1057 			for (bp = buf; *p && !strchr("\t,;.", *p); )
1058 				*bp++ = *p++;
1059 			*bp = '\0';
1060 			if (*buf == '*')
1061 				for (i = 0; i < LOG_NFACILITIES; i++)
1062 					f->f_pmask[i] = pri;
1063 			else {
1064 				i = decode(buf, facilitynames);
1065 				if (i < 0) {
1066 					(void)snprintf(ebuf, sizeof ebuf,
1067 					    "unknown facility name \"%s\"",
1068 					    buf);
1069 					logerror(ebuf);
1070 					return;
1071 				}
1072 				f->f_pmask[i >> 3] = pri;
1073 			}
1074 			while (*p == ',' || *p == ' ')
1075 				p++;
1076 		}
1077 
1078 		p = q;
1079 	}
1080 
1081 	/* skip to action part */
1082 	while (*p == '\t')
1083 		p++;
1084 
1085 	switch (*p)
1086 	{
1087 	case '@':
1088 		if (!InetInuse)
1089 			break;
1090 		(void)strcpy(f->f_un.f_forw.f_hname, ++p);
1091 		hp = gethostbyname(p);
1092 		if (hp == NULL) {
1093 			extern int h_errno;
1094 
1095 			logerror((char *)hstrerror(h_errno));
1096 			break;
1097 		}
1098 		memset(&f->f_un.f_forw.f_addr, 0,
1099 			 sizeof(f->f_un.f_forw.f_addr));
1100 		f->f_un.f_forw.f_addr.sin_family = AF_INET;
1101 		f->f_un.f_forw.f_addr.sin_port = LogPort;
1102 		memmove(&f->f_un.f_forw.f_addr.sin_addr, hp->h_addr, hp->h_length);
1103 		f->f_type = F_FORW;
1104 		break;
1105 
1106 	case '/':
1107 		(void)strcpy(f->f_un.f_fname, p);
1108 		if ((f->f_file = open(p, O_WRONLY|O_APPEND, 0)) < 0) {
1109 			f->f_type = F_UNUSED;
1110 			logerror(p);
1111 			break;
1112 		}
1113 		if (isatty(f->f_file))
1114 			f->f_type = F_TTY;
1115 		else
1116 			f->f_type = F_FILE;
1117 		if (strcmp(p, ctty) == 0)
1118 			f->f_type = F_CONSOLE;
1119 		break;
1120 
1121 	case '*':
1122 		f->f_type = F_WALL;
1123 		break;
1124 
1125 	default:
1126 		for (i = 0; i < MAXUNAMES && *p; i++) {
1127 			for (q = p; *q && *q != ','; )
1128 				q++;
1129 			(void)strncpy(f->f_un.f_uname[i], p, UT_NAMESIZE);
1130 			if ((q - p) > UT_NAMESIZE)
1131 				f->f_un.f_uname[i][UT_NAMESIZE] = '\0';
1132 			else
1133 				f->f_un.f_uname[i][q - p] = '\0';
1134 			while (*q == ',' || *q == ' ')
1135 				q++;
1136 			p = q;
1137 		}
1138 		f->f_type = F_USERS;
1139 		break;
1140 	}
1141 }
1142 
1143 
1144 /*
1145  *  Decode a symbolic name to a numeric value
1146  */
1147 int
1148 decode(name, codetab)
1149 	const char *name;
1150 	CODE *codetab;
1151 {
1152 	CODE *c;
1153 	char *p, buf[40];
1154 
1155 	if (isdigit(*name))
1156 		return (atoi(name));
1157 
1158 	for (p = buf; *name && p < &buf[sizeof(buf) - 1]; p++, name++) {
1159 		if (isupper(*name))
1160 			*p = tolower(*name);
1161 		else
1162 			*p = *name;
1163 	}
1164 	*p = '\0';
1165 	for (c = codetab; c->c_name; c++)
1166 		if (!strcmp(buf, c->c_name))
1167 			return (c->c_val);
1168 
1169 	return (-1);
1170 }
1171 
1172 /*
1173  * Retrieve the size of the kernel message buffer, via sysctl.
1174  */
1175 int
1176 getmsgbufsize()
1177 {
1178 	int msgbufsize, mib[2];
1179 	size_t size;
1180 
1181 	mib[0] = CTL_KERN;
1182 	mib[1] = KERN_MSGBUFSIZE;
1183 	size = sizeof msgbufsize;
1184 	if (sysctl(mib, 2, &msgbufsize, &size, NULL, 0) == -1) {
1185 		dprintf("couldn't get kern.msgbufsize\n");
1186 		return (0);
1187 	}
1188 	return (msgbufsize);
1189 }
1190