xref: /original-bsd/usr.sbin/syslogd/syslogd.c (revision 2e271f8d)
1 /*
2  * Copyright (c) 1983, 1988 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #ifndef lint
19 char copyright[] =
20 "@(#) Copyright (c) 1983, 1988 Regents of the University of California.\n\
21  All rights reserved.\n";
22 #endif /* not lint */
23 
24 #ifndef lint
25 static char sccsid[] = "@(#)syslogd.c	5.24 (Berkeley) 06/18/88";
26 #endif /* not lint */
27 
28 /*
29  *  syslogd -- log system messages
30  *
31  * This program implements a system log. It takes a series of lines.
32  * Each line may have a priority, signified as "<n>" as
33  * the first characters of the line.  If this is
34  * not present, a default priority is used.
35  *
36  * To kill syslogd, send a signal 15 (terminate).  A signal 1 (hup) will
37  * cause it to reread its configuration file.
38  *
39  * Defined Constants:
40  *
41  * MAXLINE -- the maximimum line length that can be handled.
42  * DEFUPRI -- the default priority for user messages
43  * DEFSPRI -- the default priority for kernel messages
44  *
45  * Author: Eric Allman
46  * extensive changes by Ralph Campbell
47  * more extensive changes by Eric Allman (again)
48  */
49 
50 #define	MAXLINE		1024		/* maximum line length */
51 #define	MAXSVLINE	120		/* maximum saved line length */
52 #define DEFUPRI		(LOG_USER|LOG_NOTICE)
53 #define DEFSPRI		(LOG_KERN|LOG_CRIT)
54 #define TIMERINTVL	30		/* interval for checking flush, mark */
55 
56 #include <stdio.h>
57 #include <utmp.h>
58 #include <ctype.h>
59 #include <strings.h>
60 #include <setjmp.h>
61 
62 #include <sys/syslog.h>
63 #include <sys/param.h>
64 #include <sys/errno.h>
65 #include <sys/ioctl.h>
66 #include <sys/stat.h>
67 #include <sys/wait.h>
68 #include <sys/socket.h>
69 #include <sys/file.h>
70 #include <sys/msgbuf.h>
71 #include <sys/uio.h>
72 #include <sys/un.h>
73 #include <sys/time.h>
74 #include <sys/resource.h>
75 #include <sys/signal.h>
76 
77 #include <netinet/in.h>
78 #include <netdb.h>
79 
80 #define	CTTY	"/dev/console"
81 char	*LogName = "/dev/log";
82 char	*ConfFile = "/etc/syslog.conf";
83 char	*PidFile = "/etc/syslog.pid";
84 char	ctty[] = CTTY;
85 
86 #define FDMASK(fd)	(1 << (fd))
87 
88 #define	dprintf		if (Debug) printf
89 
90 #define UNAMESZ		8	/* length of a login name */
91 #define MAXUNAMES	20	/* maximum number of user names */
92 #define MAXFNAME	200	/* max file pathname length */
93 
94 #define NOPRI		0x10	/* the "no priority" priority */
95 #define	LOG_MARK	LOG_MAKEPRI(LOG_NFACILITIES, 0)	/* mark "facility" */
96 
97 /*
98  * Flags to logmsg().
99  */
100 
101 #define IGN_CONS	0x001	/* don't print on console */
102 #define SYNC_FILE	0x002	/* do fsync on file after printing */
103 #define ADDDATE		0x004	/* add a date to the message */
104 #define MARK		0x008	/* this message is a mark */
105 
106 /*
107  * This structure represents the files that will have log
108  * copies printed.
109  */
110 
111 struct filed {
112 	struct	filed *f_next;		/* next in linked list */
113 	short	f_type;			/* entry type, see below */
114 	short	f_file;			/* file descriptor */
115 	time_t	f_time;			/* time this was last written */
116 	u_char	f_pmask[LOG_NFACILITIES+1];	/* priority mask */
117 	union {
118 		char	f_uname[MAXUNAMES][UNAMESZ+1];
119 		struct {
120 			char	f_hname[MAXHOSTNAMELEN+1];
121 			struct sockaddr_in	f_addr;
122 		} f_forw;		/* forwarding address */
123 		char	f_fname[MAXFNAME];
124 	} f_un;
125 	char	f_prevline[MAXSVLINE];		/* last message logged */
126 	char	f_lasttime[16];			/* time of last occurrence */
127 	char	f_prevhost[MAXHOSTNAMELEN+1];	/* host from which recd. */
128 	int	f_prevpri;			/* pri of f_prevline */
129 	int	f_prevlen;			/* length of f_prevline */
130 	int	f_prevcount;			/* repetition cnt of prevline */
131 	int	f_repeatcount;			/* number of "repeated" msgs */
132 };
133 
134 /*
135  * Intervals at which we flush out "message repeated" messages,
136  * in seconds after previous message is logged.  After each flush,
137  * we move to the next interval until we reach the largest.
138  */
139 int	repeatinterval[] = { 30, 120, 600 };	/* # of secs before flush */
140 #define	MAXREPEAT ((sizeof(repeatinterval) / sizeof(repeatinterval[0])) - 1)
141 #define	REPEATTIME(f)	((f)->f_time + repeatinterval[(f)->f_repeatcount])
142 #define	BACKOFF(f)	{ if (++(f)->f_repeatcount > MAXREPEAT) \
143 				 (f)->f_repeatcount = MAXREPEAT; \
144 			}
145 
146 /* values for f_type */
147 #define F_UNUSED	0		/* unused entry */
148 #define F_FILE		1		/* regular file */
149 #define F_TTY		2		/* terminal */
150 #define F_CONSOLE	3		/* console terminal */
151 #define F_FORW		4		/* remote machine */
152 #define F_USERS		5		/* list of users */
153 #define F_WALL		6		/* everyone logged on */
154 
155 char	*TypeNames[7] = {
156 	"UNUSED",	"FILE",		"TTY",		"CONSOLE",
157 	"FORW",		"USERS",	"WALL"
158 };
159 
160 struct	filed *Files;
161 struct	filed consfile;
162 
163 int	Debug;			/* debug flag */
164 char	LocalHostName[MAXHOSTNAMELEN+1];	/* our hostname */
165 char	*LocalDomain;		/* our local domain name */
166 int	InetInuse = 0;		/* non-zero if INET sockets are being used */
167 int	finet;			/* Internet datagram socket */
168 int	LogPort;		/* port number for INET connections */
169 int	Initialized = 0;	/* set when we have initialized ourselves */
170 int	MarkInterval = 20 * 60;	/* interval between marks in seconds */
171 int	MarkSeq = 0;		/* mark sequence number */
172 
173 extern	int errno, sys_nerr;
174 extern	char *sys_errlist[];
175 extern	char *ctime(), *index(), *calloc();
176 
177 main(argc, argv)
178 	int argc;
179 	char **argv;
180 {
181 	register int i;
182 	register char *p;
183 	int funix, inetm, fklog, klogm, len;
184 	struct sockaddr_un sunx, fromunix;
185 	struct sockaddr_in sin, frominet;
186 	FILE *fp;
187 	char line[MSG_BSIZE + 1];
188 	extern int die(), domark(), reapchild();
189 
190 	while (--argc > 0) {
191 		p = *++argv;
192 		if (p[0] != '-')
193 			usage();
194 		switch (p[1]) {
195 		case 'f':		/* configuration file */
196 			if (p[2] != '\0')
197 				ConfFile = &p[2];
198 			break;
199 
200 		case 'd':		/* debug */
201 			Debug++;
202 			break;
203 
204 		case 'p':		/* path */
205 			if (p[2] != '\0')
206 				LogName = &p[2];
207 			break;
208 
209 		case 'm':		/* mark interval */
210 			if (p[2] != '\0')
211 				MarkInterval = atoi(&p[2]) * 60;
212 			break;
213 
214 		default:
215 			usage();
216 		}
217 	}
218 
219 	if (!Debug) {
220 		if (fork())
221 			exit(0);
222 		for (i = 0; i < 10; i++)
223 			(void) close(i);
224 		(void) open("/", 0);
225 		(void) dup2(0, 1);
226 		(void) dup2(0, 2);
227 		untty();
228 	} else
229 		setlinebuf(stdout);
230 
231 	consfile.f_type = F_CONSOLE;
232 	(void) strcpy(consfile.f_un.f_fname, ctty);
233 	(void) gethostname(LocalHostName, sizeof LocalHostName);
234 	if (p = index(LocalHostName, '.')) {
235 		*p++ = '\0';
236 		LocalDomain = p;
237 	}
238 	else
239 		LocalDomain = "";
240 	(void) signal(SIGTERM, die);
241 	(void) signal(SIGINT, Debug ? die : SIG_IGN);
242 	(void) signal(SIGQUIT, Debug ? die : SIG_IGN);
243 	(void) signal(SIGCHLD, reapchild);
244 	(void) signal(SIGALRM, domark);
245 	(void) alarm(TIMERINTVL);
246 	(void) unlink(LogName);
247 
248 	sunx.sun_family = AF_UNIX;
249 	(void) strncpy(sunx.sun_path, LogName, sizeof sunx.sun_path);
250 	funix = socket(AF_UNIX, SOCK_DGRAM, 0);
251 	if (funix < 0 || bind(funix, (struct sockaddr *) &sunx,
252 	    sizeof(sunx.sun_family)+strlen(sunx.sun_path)) < 0 ||
253 	    chmod(LogName, 0666) < 0) {
254 		(void) sprintf(line, "cannot create %s", LogName);
255 		logerror(line);
256 		dprintf("cannot create %s (%d)\n", LogName, errno);
257 		die(0);
258 	}
259 	finet = socket(AF_INET, SOCK_DGRAM, 0);
260 	if (finet >= 0) {
261 		struct servent *sp;
262 
263 		sp = getservbyname("syslog", "udp");
264 		if (sp == NULL) {
265 			errno = 0;
266 			logerror("syslog/udp: unknown service");
267 			die(0);
268 		}
269 		sin.sin_family = AF_INET;
270 		sin.sin_port = LogPort = sp->s_port;
271 		if (bind(finet, &sin, sizeof(sin)) < 0) {
272 			logerror("bind");
273 			if (!Debug)
274 				die(0);
275 		} else {
276 			inetm = FDMASK(finet);
277 			InetInuse = 1;
278 		}
279 	}
280 	if ((fklog = open("/dev/klog", O_RDONLY)) >= 0)
281 		klogm = FDMASK(fklog);
282 	else {
283 		dprintf("can't open /dev/klog (%d)\n", errno);
284 		klogm = 0;
285 	}
286 
287 	/* tuck my process id away */
288 	fp = fopen(PidFile, "w");
289 	if (fp != NULL) {
290 		fprintf(fp, "%d\n", getpid());
291 		(void) fclose(fp);
292 	}
293 
294 	dprintf("off & running....\n");
295 
296 	init();
297 	(void) signal(SIGHUP, init);
298 
299 	for (;;) {
300 		int nfds, readfds = FDMASK(funix) | inetm | klogm;
301 
302 		errno = 0;
303 		dprintf("readfds = %#x\n", readfds);
304 		nfds = select(20, (fd_set *) &readfds, (fd_set *) NULL,
305 				  (fd_set *) NULL, (struct timeval *) NULL);
306 		if (nfds == 0)
307 			continue;
308 		if (nfds < 0) {
309 			if (errno != EINTR)
310 				logerror("select");
311 			continue;
312 		}
313 		dprintf("got a message (%d, %#x)\n", nfds, readfds);
314 		if (readfds & klogm) {
315 			i = read(fklog, line, sizeof(line) - 1);
316 			if (i > 0) {
317 				line[i] = '\0';
318 				printsys(line);
319 			} else if (i < 0 && errno != EINTR) {
320 				logerror("klog");
321 				fklog = -1;
322 				klogm = 0;
323 			}
324 		}
325 		if (readfds & FDMASK(funix)) {
326 			len = sizeof fromunix;
327 			i = recvfrom(funix, line, MAXLINE, 0,
328 				     (struct sockaddr *) &fromunix, &len);
329 			if (i > 0) {
330 				line[i] = '\0';
331 				printline(LocalHostName, line);
332 			} else if (i < 0 && errno != EINTR)
333 				logerror("recvfrom unix");
334 		}
335 		if (readfds & inetm) {
336 			len = sizeof frominet;
337 			i = recvfrom(finet, line, MAXLINE, 0, &frominet, &len);
338 			if (i > 0) {
339 				extern char *cvthname();
340 
341 				line[i] = '\0';
342 				printline(cvthname(&frominet), line);
343 			} else if (i < 0 && errno != EINTR)
344 				logerror("recvfrom inet");
345 		}
346 	}
347 }
348 
349 usage()
350 {
351 	fprintf(stderr, "usage: syslogd [-d] [-mmarkinterval] [-ppath] [-fconffile]\n");
352 	exit(1);
353 }
354 
355 untty()
356 {
357 	int i;
358 
359 	if (!Debug) {
360 		i = open("/dev/tty", O_RDWR);
361 		if (i >= 0) {
362 			(void) ioctl(i, (int) TIOCNOTTY, (char *)0);
363 			(void) close(i);
364 		}
365 	}
366 }
367 
368 /*
369  * Take a raw input line, decode the message, and print the message
370  * on the appropriate log files.
371  */
372 
373 printline(hname, msg)
374 	char *hname;
375 	char *msg;
376 {
377 	register char *p, *q;
378 	register int c;
379 	char line[MAXLINE + 1];
380 	int pri;
381 
382 	/* test for special codes */
383 	pri = DEFUPRI;
384 	p = msg;
385 	if (*p == '<') {
386 		pri = 0;
387 		while (isdigit(*++p))
388 			pri = 10 * pri + (*p - '0');
389 		if (*p == '>')
390 			++p;
391 	}
392 	if (pri &~ (LOG_FACMASK|LOG_PRIMASK))
393 		pri = DEFUPRI;
394 
395 	/* don't allow users to log kernel messages */
396 	if (LOG_FAC(pri) == LOG_KERN)
397 		pri = LOG_MAKEPRI(LOG_USER, LOG_PRI(pri));
398 
399 	q = line;
400 
401 	while ((c = *p++ & 0177) != '\0' && c != '\n' &&
402 	    q < &line[sizeof(line) - 1]) {
403 		if (iscntrl(c)) {
404 			*q++ = '^';
405 			*q++ = c ^ 0100;
406 		} else
407 			*q++ = c;
408 	}
409 	*q = '\0';
410 
411 	logmsg(pri, line, hname, 0);
412 }
413 
414 /*
415  * Take a raw input line from /dev/klog, split and format similar to syslog().
416  */
417 
418 printsys(msg)
419 	char *msg;
420 {
421 	register char *p, *q;
422 	register int c;
423 	char line[MAXLINE + 1];
424 	int pri, flags;
425 	char *lp;
426 
427 	(void) sprintf(line, "vmunix: ");
428 	lp = line + strlen(line);
429 	for (p = msg; *p != '\0'; ) {
430 		flags = SYNC_FILE | ADDDATE;	/* fsync file after write */
431 		pri = DEFSPRI;
432 		if (*p == '<') {
433 			pri = 0;
434 			while (isdigit(*++p))
435 				pri = 10 * pri + (*p - '0');
436 			if (*p == '>')
437 				++p;
438 		} else {
439 			/* kernel printf's come out on console */
440 			flags |= IGN_CONS;
441 		}
442 		if (pri &~ (LOG_FACMASK|LOG_PRIMASK))
443 			pri = DEFSPRI;
444 		q = lp;
445 		while (*p != '\0' && (c = *p++) != '\n' &&
446 		    q < &line[MAXLINE])
447 			*q++ = c;
448 		*q = '\0';
449 		logmsg(pri, line, LocalHostName, flags);
450 	}
451 }
452 
453 time_t	now;
454 
455 /*
456  * Log a message to the appropriate log files, users, etc. based on
457  * the priority.
458  */
459 
460 logmsg(pri, msg, from, flags)
461 	int pri;
462 	char *msg, *from;
463 	int flags;
464 {
465 	register struct filed *f;
466 	int fac, prilev;
467 	int omask, msglen;
468 	char *timestamp;
469 
470 	dprintf("logmsg: pri %o, flags %x, from %s, msg %s\n", pri, flags, from, msg);
471 
472 	omask = sigblock(sigmask(SIGHUP)|sigmask(SIGALRM));
473 
474 	/*
475 	 * Check to see if msg looks non-standard.
476 	 */
477 	msglen = strlen(msg);
478 	if (msglen < 16 || msg[3] != ' ' || msg[6] != ' ' ||
479 	    msg[9] != ':' || msg[12] != ':' || msg[15] != ' ')
480 		flags |= ADDDATE;
481 
482 	(void) time(&now);
483 	if (flags & ADDDATE)
484 		timestamp = ctime(&now) + 4;
485 	else {
486 		timestamp = msg;
487 		msg += 16;
488 		msglen -= 16;
489 	}
490 
491 	/* extract facility and priority level */
492 	if (flags & MARK)
493 		fac = LOG_NFACILITIES;
494 	else
495 		fac = LOG_FAC(pri);
496 	prilev = LOG_PRI(pri);
497 
498 	/* log the message to the particular outputs */
499 	if (!Initialized) {
500 		f = &consfile;
501 		f->f_file = open(ctty, O_WRONLY);
502 
503 		if (f->f_file >= 0) {
504 			untty();
505 			fprintlog(f, flags, (char *)NULL);
506 			(void) close(f->f_file);
507 		}
508 		(void) sigsetmask(omask);
509 		return;
510 	}
511 	for (f = Files; f; f = f->f_next) {
512 		/* skip messages that are incorrect priority */
513 		if (f->f_pmask[fac] < prilev || f->f_pmask[fac] == NOPRI)
514 			continue;
515 
516 		if (f->f_type == F_CONSOLE && (flags & IGN_CONS))
517 			continue;
518 
519 		/* don't output marks to recently written files */
520 		if ((flags & MARK) && (now - f->f_time) < MarkInterval / 2)
521 			continue;
522 
523 		/*
524 		 * suppress duplicate lines to this file
525 		 */
526 		if ((flags & MARK) == 0 && msglen == f->f_prevlen &&
527 		    !strcmp(msg, f->f_prevline) &&
528 		    !strcmp(from, f->f_prevhost)) {
529 			(void) strncpy(f->f_lasttime, timestamp, 15);
530 			f->f_prevcount++;
531 			dprintf("msg repeated %d times, %d sec of %d\n",
532 			    f->f_prevcount, now - f->f_time,
533 			    repeatinterval[f->f_repeatcount]);
534 			/*
535 			 * If domark would have logged this by now,
536 			 * flush it now (so we don't hold isolated messages),
537 			 * but back off so we'll flush less often
538 			 * in the future.
539 			 */
540 			if (now > REPEATTIME(f)) {
541 				fprintlog(f, flags, (char *)NULL);
542 				BACKOFF(f);
543 			}
544 		} else {
545 			/* new line, save it */
546 			if (f->f_prevcount)
547 				fprintlog(f, 0, (char *)NULL);
548 			f->f_repeatcount = 0;
549 			(void) strncpy(f->f_lasttime, timestamp, 15);
550 			(void) strncpy(f->f_prevhost, from,
551 					sizeof(f->f_prevhost));
552 			if (msglen < MAXSVLINE) {
553 				f->f_prevlen = msglen;
554 				f->f_prevpri = pri;
555 				(void) strcpy(f->f_prevline, msg);
556 				fprintlog(f, flags, (char *)NULL);
557 			} else {
558 				f->f_prevline[0] = 0;
559 				f->f_prevlen = 0;
560 				fprintlog(f, flags, msg);
561 			}
562 		}
563 	}
564 	(void) sigsetmask(omask);
565 }
566 
567 fprintlog(f, flags, msg)
568 	register struct filed *f;
569 	int flags;
570 	char *msg;
571 {
572 	struct iovec iov[6];
573 	register struct iovec *v = iov;
574 	register int l;
575 	char line[MAXLINE + 1];
576 	char repbuf[80];
577 
578 	v->iov_base = f->f_lasttime;
579 	v->iov_len = 15;
580 	v++;
581 	v->iov_base = " ";
582 	v->iov_len = 1;
583 	v++;
584 	v->iov_base = f->f_prevhost;
585 	v->iov_len = strlen(v->iov_base);
586 	v++;
587 	v->iov_base = " ";
588 	v->iov_len = 1;
589 	v++;
590 	if (msg) {
591 		v->iov_base = msg;
592 		v->iov_len = strlen(msg);
593 	} else if (f->f_prevcount > 1) {
594 		(void) sprintf(repbuf, "last message repeated %d times",
595 		    f->f_prevcount);
596 		v->iov_base = repbuf;
597 		v->iov_len = strlen(repbuf);
598 	} else {
599 		v->iov_base = f->f_prevline;
600 		v->iov_len = f->f_prevlen;
601 	}
602 	v++;
603 
604 	dprintf("Logging to %s", TypeNames[f->f_type]);
605 	f->f_time = now;
606 
607 	switch (f->f_type) {
608 	case F_UNUSED:
609 		dprintf("\n");
610 		break;
611 
612 	case F_FORW:
613 		dprintf(" %s\n", f->f_un.f_forw.f_hname);
614 		(void) sprintf(line, "<%d>%.15s %s", f->f_prevpri,
615 			iov[0].iov_base, iov[4].iov_base);
616 		l = strlen(line);
617 		if (l > MAXLINE)
618 			l = MAXLINE;
619 		if (sendto(finet, line, l, 0, &f->f_un.f_forw.f_addr,
620 		    sizeof f->f_un.f_forw.f_addr) != l) {
621 			int e = errno;
622 			(void) close(f->f_file);
623 			f->f_type = F_UNUSED;
624 			errno = e;
625 			logerror("sendto");
626 		}
627 		break;
628 
629 	case F_CONSOLE:
630 		if (flags & IGN_CONS) {
631 			dprintf(" (ignored)\n");
632 			break;
633 		}
634 		/* FALLTHROUGH */
635 
636 	case F_TTY:
637 	case F_FILE:
638 		dprintf(" %s\n", f->f_un.f_fname);
639 		if (f->f_type != F_FILE) {
640 			v->iov_base = "\r\n";
641 			v->iov_len = 2;
642 		} else {
643 			v->iov_base = "\n";
644 			v->iov_len = 1;
645 		}
646 	again:
647 		if (writev(f->f_file, iov, 6) < 0) {
648 			int e = errno;
649 			(void) close(f->f_file);
650 			/*
651 			 * Check for EBADF on TTY's due to vhangup() XXX
652 			 */
653 			if (e == EBADF && f->f_type != F_FILE) {
654 				f->f_file = open(f->f_un.f_fname, O_WRONLY|O_APPEND);
655 				if (f->f_file < 0) {
656 					f->f_type = F_UNUSED;
657 					logerror(f->f_un.f_fname);
658 				} else {
659 					untty();
660 					goto again;
661 				}
662 			} else {
663 				f->f_type = F_UNUSED;
664 				errno = e;
665 				logerror(f->f_un.f_fname);
666 			}
667 		} else if (flags & SYNC_FILE)
668 			(void) fsync(f->f_file);
669 		break;
670 
671 	case F_USERS:
672 	case F_WALL:
673 		dprintf("\n");
674 		v->iov_base = "\r\n";
675 		v->iov_len = 2;
676 		wallmsg(f, iov);
677 		break;
678 	}
679 	f->f_prevcount = 0;
680 }
681 
682 jmp_buf ttybuf;
683 
684 endtty()
685 {
686 	longjmp(ttybuf, 1);
687 }
688 
689 /*
690  *  WALLMSG -- Write a message to the world at large
691  *
692  *	Write the specified message to either the entire
693  *	world, or a list of approved users.
694  */
695 
696 wallmsg(f, iov)
697 	register struct filed *f;
698 	struct iovec *iov;
699 {
700 	register char *p;
701 	register int i;
702 	int ttyf, len;
703 	FILE *uf;
704 	static int reenter = 0;
705 	struct utmp ut;
706 	char greetings[200];
707 
708 	if (reenter++)
709 		return;
710 
711 	/* open the user login file */
712 	if ((uf = fopen("/etc/utmp", "r")) == NULL) {
713 		logerror("/etc/utmp");
714 		reenter = 0;
715 		return;
716 	}
717 
718 	/*
719 	 * Might as well fork instead of using nonblocking I/O
720 	 * and doing notty().
721 	 */
722 	if (fork() == 0) {
723 		(void) signal(SIGTERM, SIG_DFL);
724 		(void) alarm(0);
725 		(void) signal(SIGALRM, endtty);
726 		(void) signal(SIGTTOU, SIG_IGN);
727 		(void) sigsetmask(0);
728 		(void) sprintf(greetings,
729 		    "\r\n\7Message from syslogd@%s at %.24s ...\r\n",
730 			iov[2].iov_base, ctime(&now));
731 		len = strlen(greetings);
732 
733 		/* scan the user login file */
734 		while (fread((char *) &ut, sizeof ut, 1, uf) == 1) {
735 			/* is this slot used? */
736 			if (ut.ut_name[0] == '\0')
737 				continue;
738 
739 			/* should we send the message to this user? */
740 			if (f->f_type == F_USERS) {
741 				for (i = 0; i < MAXUNAMES; i++) {
742 					if (!f->f_un.f_uname[i][0]) {
743 						i = MAXUNAMES;
744 						break;
745 					}
746 					if (strncmp(f->f_un.f_uname[i],
747 					    ut.ut_name, UNAMESZ) == 0)
748 						break;
749 				}
750 				if (i >= MAXUNAMES)
751 					continue;
752 			}
753 
754 			/* compute the device name */
755 			p = "/dev/12345678";
756 			strncpy(&p[5], ut.ut_line, UNAMESZ);
757 
758 			if (f->f_type == F_WALL) {
759 				iov[0].iov_base = greetings;
760 				iov[0].iov_len = len;
761 				iov[1].iov_len = 0;
762 			}
763 			if (setjmp(ttybuf) == 0) {
764 				(void) alarm(15);
765 				/* open the terminal */
766 				ttyf = open(p, O_WRONLY);
767 				if (ttyf >= 0) {
768 					struct stat statb;
769 
770 					if (fstat(ttyf, &statb) == 0 &&
771 					    (statb.st_mode & S_IWRITE))
772 						(void) writev(ttyf, iov, 6);
773 					close(ttyf);
774 					ttyf = -1;
775 				}
776 			}
777 			(void) alarm(0);
778 		}
779 		exit(0);
780 	}
781 	/* close the user login file */
782 	(void) fclose(uf);
783 	reenter = 0;
784 }
785 
786 reapchild()
787 {
788 	union wait status;
789 
790 	while (wait3(&status, WNOHANG, (struct rusage *) NULL) > 0)
791 		;
792 }
793 
794 /*
795  * Return a printable representation of a host address.
796  */
797 char *
798 cvthname(f)
799 	struct sockaddr_in *f;
800 {
801 	struct hostent *hp;
802 	register char *p;
803 	extern char *inet_ntoa();
804 
805 	dprintf("cvthname(%s)\n", inet_ntoa(f->sin_addr));
806 
807 	if (f->sin_family != AF_INET) {
808 		dprintf("Malformed from address\n");
809 		return ("???");
810 	}
811 	hp = gethostbyaddr(&f->sin_addr, sizeof(struct in_addr), f->sin_family);
812 	if (hp == 0) {
813 		dprintf("Host name for your address (%s) unknown\n",
814 			inet_ntoa(f->sin_addr));
815 		return (inet_ntoa(f->sin_addr));
816 	}
817 	if ((p = index(hp->h_name, '.')) && strcmp(p + 1, LocalDomain) == 0)
818 		*p = '\0';
819 	return (hp->h_name);
820 }
821 
822 domark()
823 {
824 	register struct filed *f;
825 
826 	now = time(0);
827 	MarkSeq += TIMERINTVL;
828 	if (MarkSeq >= MarkInterval) {
829 		logmsg(LOG_INFO, "-- MARK --", LocalHostName, ADDDATE|MARK);
830 		MarkSeq = 0;
831 	}
832 
833 	for (f = Files; f; f = f->f_next) {
834 		if (f->f_prevcount && now >= REPEATTIME(f)) {
835 			dprintf("flush %s: repeated %d times, %d sec.\n",
836 			    TypeNames[f->f_type], f->f_prevcount,
837 			    repeatinterval[f->f_repeatcount]);
838 			fprintlog(f, 0, (char *)NULL);
839 			BACKOFF(f);
840 		}
841 	}
842 	(void) alarm(TIMERINTVL);
843 }
844 
845 /*
846  * Print syslogd errors some place.
847  */
848 logerror(type)
849 	char *type;
850 {
851 	char buf[100];
852 
853 	if (errno == 0)
854 		(void) sprintf(buf, "syslogd: %s", type);
855 	else if ((unsigned) errno > sys_nerr)
856 		(void) sprintf(buf, "syslogd: %s: error %d", type, errno);
857 	else
858 		(void) sprintf(buf, "syslogd: %s: %s", type, sys_errlist[errno]);
859 	errno = 0;
860 	dprintf("%s\n", buf);
861 	logmsg(LOG_SYSLOG|LOG_ERR, buf, LocalHostName, ADDDATE);
862 }
863 
864 die(sig)
865 {
866 	register struct filed *f;
867 	char buf[100];
868 
869 	for (f = Files; f != NULL; f = f->f_next) {
870 		/* flush any pending output */
871 		if (f->f_prevcount)
872 			fprintlog(f, 0, (char *)NULL);
873 	}
874 	if (sig) {
875 		dprintf("syslogd: exiting on signal %d\n", sig);
876 		(void) sprintf(buf, "exiting on signal %d", sig);
877 		errno = 0;
878 		logerror(buf);
879 	}
880 	(void) unlink(LogName);
881 	exit(0);
882 }
883 
884 /*
885  *  INIT -- Initialize syslogd from configuration table
886  */
887 
888 init()
889 {
890 	register int i;
891 	register FILE *cf;
892 	register struct filed *f, *next, **nextp;
893 	register char *p;
894 	char cline[BUFSIZ];
895 
896 	dprintf("init\n");
897 
898 	/*
899 	 *  Close all open log files.
900 	 */
901 	Initialized = 0;
902 	for (f = Files; f != NULL; f = next) {
903 		/* flush any pending output */
904 		if (f->f_prevcount)
905 			fprintlog(f, 0, (char *)NULL);
906 
907 		switch (f->f_type) {
908 		  case F_FILE:
909 		  case F_TTY:
910 		  case F_CONSOLE:
911 			(void) close(f->f_file);
912 			break;
913 		}
914 		next = f->f_next;
915 		free((char *) f);
916 	}
917 	Files = NULL;
918 	nextp = &Files;
919 
920 	/* open the configuration file */
921 	if ((cf = fopen(ConfFile, "r")) == NULL) {
922 		dprintf("cannot open %s\n", ConfFile);
923 		*nextp = (struct filed *)calloc(1, sizeof(*f));
924 		cfline("*.ERR\t/dev/console", *nextp);
925 		(*nextp)->f_next = (struct filed *)calloc(1, sizeof(*f));
926 		cfline("*.PANIC\t*", (*nextp)->f_next);
927 		Initialized = 1;
928 		return;
929 	}
930 
931 	/*
932 	 *  Foreach line in the conf table, open that file.
933 	 */
934 	f = NULL;
935 	while (fgets(cline, sizeof cline, cf) != NULL) {
936 		/*
937 		 * check for end-of-section, comments, strip off trailing
938 		 * spaces and newline character.
939 		 */
940 		for (p = cline; isspace(*p); ++p);
941 		if (*p == NULL || *p == '#')
942 			continue;
943 		for (p = index(cline, '\0'); isspace(*--p););
944 		*++p = '\0';
945 		f = (struct filed *)calloc(1, sizeof(*f));
946 		*nextp = f;
947 		nextp = &f->f_next;
948 		cfline(cline, f);
949 	}
950 
951 	/* close the configuration file */
952 	(void) fclose(cf);
953 
954 	Initialized = 1;
955 
956 	if (Debug) {
957 		for (f = Files; f; f = f->f_next) {
958 			for (i = 0; i <= LOG_NFACILITIES; i++)
959 				if (f->f_pmask[i] == NOPRI)
960 					printf("X ");
961 				else
962 					printf("%d ", f->f_pmask[i]);
963 			printf("%s: ", TypeNames[f->f_type]);
964 			switch (f->f_type) {
965 			case F_FILE:
966 			case F_TTY:
967 			case F_CONSOLE:
968 				printf("%s", f->f_un.f_fname);
969 				break;
970 
971 			case F_FORW:
972 				printf("%s", f->f_un.f_forw.f_hname);
973 				break;
974 
975 			case F_USERS:
976 				for (i = 0; i < MAXUNAMES && *f->f_un.f_uname[i]; i++)
977 					printf("%s, ", f->f_un.f_uname[i]);
978 				break;
979 			}
980 			printf("\n");
981 		}
982 	}
983 
984 	logmsg(LOG_SYSLOG|LOG_INFO, "syslogd: restart", LocalHostName, ADDDATE);
985 	dprintf("syslogd: restarted\n");
986 }
987 
988 /*
989  * Crack a configuration file line
990  */
991 
992 struct code {
993 	char	*c_name;
994 	int	c_val;
995 };
996 
997 struct code	PriNames[] = {
998 	"panic",	LOG_EMERG,
999 	"emerg",	LOG_EMERG,
1000 	"alert",	LOG_ALERT,
1001 	"crit",		LOG_CRIT,
1002 	"err",		LOG_ERR,
1003 	"error",	LOG_ERR,
1004 	"warn",		LOG_WARNING,
1005 	"warning",	LOG_WARNING,
1006 	"notice",	LOG_NOTICE,
1007 	"info",		LOG_INFO,
1008 	"debug",	LOG_DEBUG,
1009 	"none",		NOPRI,
1010 	NULL,		-1
1011 };
1012 
1013 struct code	FacNames[] = {
1014 	"kern",		LOG_KERN,
1015 	"user",		LOG_USER,
1016 	"mail",		LOG_MAIL,
1017 	"daemon",	LOG_DAEMON,
1018 	"auth",		LOG_AUTH,
1019 	"security",	LOG_AUTH,
1020 	"mark",		LOG_MARK,
1021 	"syslog",	LOG_SYSLOG,
1022 	"lpr",		LOG_LPR,
1023 	"news",		LOG_NEWS,
1024 	"uucp",		LOG_UUCP,
1025 	"local0",	LOG_LOCAL0,
1026 	"local1",	LOG_LOCAL1,
1027 	"local2",	LOG_LOCAL2,
1028 	"local3",	LOG_LOCAL3,
1029 	"local4",	LOG_LOCAL4,
1030 	"local5",	LOG_LOCAL5,
1031 	"local6",	LOG_LOCAL6,
1032 	"local7",	LOG_LOCAL7,
1033 	NULL,		-1
1034 };
1035 
1036 cfline(line, f)
1037 	char *line;
1038 	register struct filed *f;
1039 {
1040 	register char *p;
1041 	register char *q;
1042 	register int i;
1043 	char *bp;
1044 	int pri;
1045 	struct hostent *hp;
1046 	char buf[MAXLINE];
1047 
1048 	dprintf("cfline(%s)\n", line);
1049 
1050 	errno = 0;	/* keep sys_errlist stuff out of logerror messages */
1051 
1052 	/* clear out file entry */
1053 	bzero((char *) f, sizeof *f);
1054 	for (i = 0; i <= LOG_NFACILITIES; i++)
1055 		f->f_pmask[i] = NOPRI;
1056 
1057 	/* scan through the list of selectors */
1058 	for (p = line; *p && *p != '\t';) {
1059 
1060 		/* find the end of this facility name list */
1061 		for (q = p; *q && *q != '\t' && *q++ != '.'; )
1062 			continue;
1063 
1064 		/* collect priority name */
1065 		for (bp = buf; *q && !index("\t,;", *q); )
1066 			*bp++ = *q++;
1067 		*bp = '\0';
1068 
1069 		/* skip cruft */
1070 		while (index(", ;", *q))
1071 			q++;
1072 
1073 		/* decode priority name */
1074 		pri = decode(buf, PriNames);
1075 		if (pri < 0) {
1076 			char xbuf[200];
1077 
1078 			(void) sprintf(xbuf, "unknown priority name \"%s\"", buf);
1079 			logerror(xbuf);
1080 			return;
1081 		}
1082 
1083 		/* scan facilities */
1084 		while (*p && !index("\t.;", *p)) {
1085 			int i;
1086 
1087 			for (bp = buf; *p && !index("\t,;.", *p); )
1088 				*bp++ = *p++;
1089 			*bp = '\0';
1090 			if (*buf == '*')
1091 				for (i = 0; i < LOG_NFACILITIES; i++)
1092 					f->f_pmask[i] = pri;
1093 			else {
1094 				i = decode(buf, FacNames);
1095 				if (i < 0) {
1096 					char xbuf[200];
1097 
1098 					(void) sprintf(xbuf, "unknown facility name \"%s\"", buf);
1099 					logerror(xbuf);
1100 					return;
1101 				}
1102 				f->f_pmask[i >> 3] = pri;
1103 			}
1104 			while (*p == ',' || *p == ' ')
1105 				p++;
1106 		}
1107 
1108 		p = q;
1109 	}
1110 
1111 	/* skip to action part */
1112 	while (*p == '\t')
1113 		p++;
1114 
1115 	switch (*p)
1116 	{
1117 	case '@':
1118 		if (!InetInuse)
1119 			break;
1120 		(void) strcpy(f->f_un.f_forw.f_hname, ++p);
1121 		hp = gethostbyname(p);
1122 		if (hp == NULL) {
1123 			char buf[100];
1124 
1125 			(void) sprintf(buf, "unknown host %s", p);
1126 			errno = 0;
1127 			logerror(buf);
1128 			break;
1129 		}
1130 		bzero((char *) &f->f_un.f_forw.f_addr,
1131 			 sizeof f->f_un.f_forw.f_addr);
1132 		f->f_un.f_forw.f_addr.sin_family = AF_INET;
1133 		f->f_un.f_forw.f_addr.sin_port = LogPort;
1134 		bcopy(hp->h_addr, (char *) &f->f_un.f_forw.f_addr.sin_addr, hp->h_length);
1135 		f->f_type = F_FORW;
1136 		break;
1137 
1138 	case '/':
1139 		(void) strcpy(f->f_un.f_fname, p);
1140 		if ((f->f_file = open(p, O_WRONLY|O_APPEND)) < 0) {
1141 			f->f_file = F_UNUSED;
1142 			logerror(p);
1143 			break;
1144 		}
1145 		if (isatty(f->f_file)) {
1146 			f->f_type = F_TTY;
1147 			untty();
1148 		}
1149 		else
1150 			f->f_type = F_FILE;
1151 		if (strcmp(p, ctty) == 0)
1152 			f->f_type = F_CONSOLE;
1153 		break;
1154 
1155 	case '*':
1156 		f->f_type = F_WALL;
1157 		break;
1158 
1159 	default:
1160 		for (i = 0; i < MAXUNAMES && *p; i++) {
1161 			for (q = p; *q && *q != ','; )
1162 				q++;
1163 			(void) strncpy(f->f_un.f_uname[i], p, UNAMESZ);
1164 			if ((q - p) > UNAMESZ)
1165 				f->f_un.f_uname[i][UNAMESZ] = '\0';
1166 			else
1167 				f->f_un.f_uname[i][q - p] = '\0';
1168 			while (*q == ',' || *q == ' ')
1169 				q++;
1170 			p = q;
1171 		}
1172 		f->f_type = F_USERS;
1173 		break;
1174 	}
1175 }
1176 
1177 
1178 /*
1179  *  Decode a symbolic name to a numeric value
1180  */
1181 
1182 decode(name, codetab)
1183 	char *name;
1184 	struct code *codetab;
1185 {
1186 	register struct code *c;
1187 	register char *p;
1188 	char buf[40];
1189 
1190 	if (isdigit(*name))
1191 		return (atoi(name));
1192 
1193 	(void) strcpy(buf, name);
1194 	for (p = buf; *p; p++)
1195 		if (isupper(*p))
1196 			*p = tolower(*p);
1197 	for (c = codetab; c->c_name; c++)
1198 		if (!strcmp(buf, c->c_name))
1199 			return (c->c_val);
1200 
1201 	return (-1);
1202 }
1203