xref: /csrg-svn/lib/libc/gen/syslog.c (revision 17918)
112742Ssam #ifndef lint
2*17918Sralph static char sccsid[] = "@(#)syslog.c	4.6 (Berkeley) 02/04/85";
312742Ssam #endif
412742Ssam 
512742Ssam /*
612742Ssam  * SYSLOG -- print message on log file
712742Ssam  *
812742Ssam  * This routine looks a lot like printf, except that it
912742Ssam  * outputs to the log file instead of the standard output.
1016414Sralph  * Also:
1116414Sralph  *	adds a timestamp,
1216414Sralph  *	prints the module name in front of the message,
1316414Sralph  *	has some other formatting types (or will sometime),
1416414Sralph  *	adds a newline on the end of the message.
1512742Ssam  *
1616414Sralph  * The output of this routine is intended to be read by /etc/syslogd.
1716943Sralph  *
1816943Sralph  * Author: Eric Allman
1916943Sralph  * Modified to use UNIX domain IPC by Ralph Campbell
2012742Ssam  */
2116414Sralph 
2212742Ssam #include <sys/types.h>
2312742Ssam #include <sys/socket.h>
2416414Sralph #include <sys/file.h>
2512742Ssam #include <syslog.h>
2612742Ssam #include <netdb.h>
2712742Ssam 
2816414Sralph #define	MAXLINE	1024			/* max message size */
2916414Sralph #define NULL	0			/* manifest */
3012742Ssam 
31*17918Sralph #define mask(p)	(1 << (p))
32*17918Sralph #define IMPORTANT (mask(KERN_EMERG)|mask(KERN_ALERT)|mask(KERN_ERR)|mask(KERN_FAIL)\
33*17918Sralph 	|mask(KERN_RECOV)|mask(KERN_INFO)|mask(LOG_EMERG)|mask(LOG_ALERT)\
34*17918Sralph 	|mask(LOG_CRIT)|mask(LOG_ERR)|mask(LOG_FAIL))
35*17918Sralph 
3616414Sralph static char	logname[] = "/dev/log";
3716414Sralph static char	ctty[] = "/dev/console";
3812742Ssam 
3916414Sralph static int	LogFile = -1;		/* fd for log */
4016414Sralph static int	LogStat	= 0;		/* status bits, set by openlog() */
4116414Sralph static char	*LogTag = NULL;		/* string to tag the entry with */
4217526Sralph static int	LogMask = 0xffffffff;	/* mask of priorities to be logged */
4312742Ssam 
4416414Sralph static struct sockaddr SyslogAddr;
4516414Sralph 
4612742Ssam extern	int errno, sys_nerr;
4712742Ssam extern	char *sys_errlist[];
4812742Ssam 
4912742Ssam syslog(pri, fmt, p0, p1, p2, p3, p4)
5012742Ssam 	int pri;
5112742Ssam 	char *fmt;
5212742Ssam {
5316414Sralph 	char buf[MAXLINE + 1], outline[MAXLINE + 1];
5416414Sralph 	register char *b, *f, *o;
5516414Sralph 	register int c;
5616414Sralph 	long now;
5716943Sralph 	int pid, olderrno = errno;
5812742Ssam 
5912742Ssam 	/* see if we should just throw out this message */
60*17918Sralph 	if (pri <= 0 || pri >= 32 || (mask(pri) & LogMask) == 0)
6112742Ssam 		return;
6216414Sralph 	if (LogFile < 0)
63*17918Sralph 		openlog(LogTag, LogStat & ~LOG_ODELAY, 0);
6416414Sralph 	o = outline;
6516943Sralph 	sprintf(o, "<%d>", pri);
6616943Sralph 	o += strlen(o);
6716414Sralph 	if (LogTag) {
6816414Sralph 		strcpy(o, LogTag);
6916414Sralph 		o += strlen(o);
7016414Sralph 	}
7116414Sralph 	if (LogStat & LOG_PID) {
7216943Sralph 		sprintf(o, "[%d]", getpid());
7316414Sralph 		o += strlen(o);
7416414Sralph 	}
7516414Sralph 	time(&now);
7616943Sralph 	sprintf(o, ": %.15s-- ", ctime(&now) + 4);
7716414Sralph 	o += strlen(o);
7812742Ssam 
7916414Sralph 	b = buf;
8016414Sralph 	f = fmt;
8116414Sralph 	while ((c = *f++) != '\0' && c != '\n' && b < &buf[MAXLINE]) {
8216414Sralph 		if (c != '%') {
8316414Sralph 			*b++ = c;
8416414Sralph 			continue;
8512742Ssam 		}
8616414Sralph 		if ((c = *f++) != 'm') {
8716414Sralph 			*b++ = '%';
8816414Sralph 			*b++ = c;
8916414Sralph 			continue;
9012742Ssam 		}
9116943Sralph 		if ((unsigned)olderrno > sys_nerr)
9216943Sralph 			sprintf(b, "error %d", olderrno);
9312742Ssam 		else
9416943Sralph 			strcpy(b, sys_errlist[olderrno]);
9516414Sralph 		b += strlen(b);
9612742Ssam 	}
9716414Sralph 	*b++ = '\n';
9816414Sralph 	*b = '\0';
9916414Sralph 	sprintf(o, buf, p0, p1, p2, p3, p4);
10016414Sralph 	c = strlen(outline);
10116414Sralph 	if (c > MAXLINE)
10216414Sralph 		c = MAXLINE;
10316414Sralph 	if (sendto(LogFile, outline, c, 0, &SyslogAddr, sizeof SyslogAddr) >= 0)
10416414Sralph 		return;
105*17918Sralph 	if (!(LogStat & LOG_CONS) && !(mask(pri) & IMPORTANT))
10616414Sralph 		return;
10716414Sralph 	pid = fork();
10816414Sralph 	if (pid == -1)
10916414Sralph 		return;
11016414Sralph 	if (pid == 0) {
11116414Sralph 		LogFile = open(ctty, O_RDWR);
112*17918Sralph 		strcat(o, "\r");
113*17918Sralph 		write(LogFile, outline, c+1);
11416414Sralph 		close(LogFile);
11516414Sralph 		exit(0);
11616414Sralph 	}
11716943Sralph 	while ((c = wait((int *)0)) > 0 && c != pid)
11816414Sralph 		;
11912742Ssam }
12012742Ssam 
12112742Ssam /*
12212742Ssam  * OPENLOG -- open system log
12312742Ssam  */
12416414Sralph openlog(ident, logstat, logmask)
12512742Ssam 	char *ident;
12616414Sralph 	int logstat, logmask;
12712742Ssam {
12812742Ssam 
12916943Sralph 	LogTag = (ident != NULL) ? ident : "syslog";
13012742Ssam 	LogStat = logstat;
13117526Sralph 	if (logmask != 0)
13216414Sralph 		LogMask = logmask;
13312742Ssam 	if (LogFile >= 0)
13412742Ssam 		return;
13516414Sralph 	SyslogAddr.sa_family = AF_UNIX;
13616414Sralph 	strncpy(SyslogAddr.sa_data, logname, sizeof SyslogAddr.sa_data);
137*17918Sralph 	if (!(LogStat & LOG_ODELAY)) {
138*17918Sralph 		LogFile = socket(AF_UNIX, SOCK_DGRAM, 0);
139*17918Sralph 		fcntl(LogFile, F_SETFD, 1);
140*17918Sralph 	}
14112742Ssam }
14212742Ssam 
14312742Ssam /*
14412742Ssam  * CLOSELOG -- close the system log
14512742Ssam  */
14612742Ssam closelog()
14712742Ssam {
14812742Ssam 
14912742Ssam 	(void) close(LogFile);
15012742Ssam 	LogFile = -1;
15112742Ssam }
15216414Sralph 
15316414Sralph /*
15416414Sralph  * SETLOGMASK -- set the log mask level
15516414Sralph  */
15617526Sralph setlogmask(pmask)
15717526Sralph 	int pmask;
15816414Sralph {
15917526Sralph 	int omask;
16016414Sralph 
16117526Sralph 	omask = LogMask;
16217526Sralph 	if (pmask != 0)
16317526Sralph 		LogMask = pmask;
16417526Sralph 	return (omask);
16516414Sralph }
166