xref: /original-bsd/lib/libc/gen/syslog.c (revision 07d71086)
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 #if defined(LIBC_SCCS) && !defined(lint)
19 static char sccsid[] = "@(#)syslog.c	5.23 (Berkeley) 08/04/89";
20 #endif /* LIBC_SCCS and not lint */
21 
22 /*
23  * SYSLOG -- print message on log file
24  *
25  * This routine looks a lot like printf, except that it outputs to the
26  * log file instead of the standard output.  Also:
27  *	adds a timestamp,
28  *	prints the module name in front of the message,
29  *	has some other formatting types (or will sometime),
30  *	adds a newline on the end of the message.
31  *
32  * The output of this routine is intended to be read by syslogd(8).
33  *
34  * Author: Eric Allman
35  * Modified to use UNIX domain IPC by Ralph Campbell
36  */
37 
38 #include <sys/types.h>
39 #include <sys/socket.h>
40 #include <sys/file.h>
41 #include <sys/signal.h>
42 #include <sys/syslog.h>
43 #include <sys/uio.h>
44 #include <sys/wait.h>
45 #include <netdb.h>
46 #include <strings.h>
47 #include <varargs.h>
48 #include <paths.h>
49 #include <stdio.h>
50 
51 #define	_PATH_LOGNAME	"/dev/log"
52 
53 static int	LogFile = -1;		/* fd for log */
54 static int	connected;		/* have done connect */
55 static int	LogStat = 0;		/* status bits, set by openlog() */
56 static char	*LogTag = "syslog";	/* string to tag the entry with */
57 static int	LogFacility = LOG_USER;	/* default facility code */
58 
59 syslog(pri, fmt, args)
60 	int pri, args;
61 	char *fmt;
62 {
63 	vsyslog(pri, fmt, &args);
64 }
65 
66 vsyslog(pri, fmt, ap)
67 	int pri;
68 	register char *fmt;
69 	va_list ap;
70 {
71 	extern int errno;
72 	register int cnt;
73 	register char *p;
74 	time_t now, time();
75 	int fd, saved_errno;
76 	char tbuf[2048], fmt_cpy[1024], *stdp, *ctime();
77 
78 	saved_errno = errno;
79 
80 	/* see if we should just throw out this message */
81 	if ((u_int)LOG_FAC(pri) >= LOG_NFACILITIES ||
82 	    !LOG_MASK(LOG_PRI(pri)) || (pri &~ (LOG_PRIMASK|LOG_FACMASK)))
83 		return;
84 	if (LogFile < 0 || !connected)
85 		openlog(LogTag, LogStat | LOG_NDELAY, 0);
86 
87 	/* set default facility if none specified */
88 	if ((pri & LOG_FACMASK) == 0)
89 		pri |= LogFacility;
90 
91 	/* build the message */
92 	(void)time(&now);
93 	(void)sprintf(tbuf, "<%d>%.15s ", pri, ctime(&now) + 4);
94 	for (p = tbuf; *p; ++p);
95 	if (LogStat & LOG_PERROR)
96 		stdp = p;
97 	if (LogTag) {
98 		(void)strcpy(p, LogTag);
99 		for (; *p; ++p);
100 	}
101 	if (LogStat & LOG_PID) {
102 		(void)sprintf(p, "[%d]", getpid());
103 		for (; *p; ++p);
104 	}
105 	if (LogTag) {
106 		*p++ = ':';
107 		*p++ = ' ';
108 	}
109 
110 	/* substitute error message for %m */
111 	{
112 		register char ch, *t1, *t2;
113 		char *strerror();
114 
115 		for (t1 = fmt_cpy; ch = *fmt; ++fmt)
116 			if (ch == '%' && fmt[1] == 'm') {
117 				++fmt;
118 				for (t2 = strerror(saved_errno);
119 				    *t1 = *t2++; ++t1);
120 			}
121 			else
122 				*t1++ = ch;
123 		*t1 = '\0';
124 	}
125 
126 	(void)vsprintf(p, fmt_cpy, ap);
127 
128 	cnt = strlen(tbuf);
129 
130 	/* output to stderr if requested */
131 	if (LogStat & LOG_PERROR) {
132 		struct iovec iov[2];
133 		register struct iovec *v = iov;
134 
135 		v->iov_base = stdp;
136 		v->iov_len = cnt - (stdp - tbuf);
137 		++v;
138 		v->iov_base = "\n";
139 		v->iov_len = 1;
140 		(void)writev(2, iov, 2);
141 	}
142 
143 	/* output the message to the local logger */
144 	if (send(LogFile, tbuf, cnt, 0) >= 0 || !(LogStat&LOG_CONS))
145 		return;
146 
147 	/*
148 	 * output the message to the console; don't worry about
149 	 * blocking, if console blocks everything will.
150 	 */
151 	if ((fd = open(_PATH_CONSOLE, O_WRONLY, 0)) < 0)
152 		return;
153 	(void)strcat(tbuf, "\r");
154 	p = index(tbuf, '>') + 1;
155 	(void)write(fd, p, cnt + 1 - (p - tbuf));
156 	(void)close(fd);
157 }
158 
159 static struct sockaddr SyslogAddr;	/* AF_UNIX address of local logger */
160 /*
161  * OPENLOG -- open system log
162  */
163 openlog(ident, logstat, logfac)
164 	char *ident;
165 	int logstat, logfac;
166 {
167 	if (ident != NULL)
168 		LogTag = ident;
169 	LogStat = logstat;
170 	if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
171 		LogFacility = logfac;
172 	if (LogFile == -1) {
173 		SyslogAddr.sa_family = AF_UNIX;
174 		strncpy(SyslogAddr.sa_data, _PATH_LOGNAME,
175 		    sizeof(SyslogAddr.sa_data));
176 		if (LogStat & LOG_NDELAY) {
177 			LogFile = socket(AF_UNIX, SOCK_DGRAM, 0);
178 			fcntl(LogFile, F_SETFD, 1);
179 		}
180 	}
181 	if (LogFile != -1 && !connected &&
182 	    connect(LogFile, &SyslogAddr, sizeof(SyslogAddr)) != -1)
183 		connected = 1;
184 }
185 
186 /*
187  * CLOSELOG -- close the system log
188  */
189 closelog()
190 {
191 	(void) close(LogFile);
192 	LogFile = -1;
193 	connected = 0;
194 }
195 
196 static int	LogMask = 0xff;		/* mask of priorities to be logged */
197 /*
198  * SETLOGMASK -- set the log mask level
199  */
200 setlogmask(pmask)
201 	int pmask;
202 {
203 	int omask;
204 
205 	omask = LogMask;
206 	if (pmask != 0)
207 		LogMask = pmask;
208 	return (omask);
209 }
210