xref: /netbsd-src/lib/libc/gen/syslog.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
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, 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 #if defined(LIBC_SCCS) && !defined(lint)
35 /*static char *sccsid = "from: @(#)syslog.c	5.36 (Berkeley) 10/4/92";*/
36 static char *rcsid = "$Id: syslog.c,v 1.5 1993/11/24 19:43:57 jtc Exp $";
37 #endif /* LIBC_SCCS and not lint */
38 
39 #include <sys/types.h>
40 #include <sys/socket.h>
41 #include <sys/syslog.h>
42 #include <sys/uio.h>
43 #include <netdb.h>
44 
45 #include <errno.h>
46 #include <fcntl.h>
47 #include <paths.h>
48 #include <stdio.h>
49 #include <string.h>
50 #include <time.h>
51 #include <unistd.h>
52 
53 #if __STDC__
54 #include <stdarg.h>
55 #else
56 #include <varargs.h>
57 #endif
58 
59 static int	LogFile = -1;		/* fd for log */
60 static int	connected;		/* have done connect */
61 static int	LogStat = 0;		/* status bits, set by openlog() */
62 static const char *LogTag = "syslog";	/* string to tag the entry with */
63 static int	LogFacility = LOG_USER;	/* default facility code */
64 static int	LogMask = 0xff;		/* mask of priorities to be logged */
65 
66 /*
67  * syslog, vsyslog --
68  *	print message on log file; output is intended for syslogd(8).
69  */
70 void
71 #if __STDC__
72 syslog(int pri, const char *fmt, ...)
73 #else
74 syslog(pri, fmt, va_alist)
75 	int pri;
76 	char *fmt;
77 	va_dcl
78 #endif
79 {
80 	va_list ap;
81 
82 #if __STDC__
83 	va_start(ap, fmt);
84 #else
85 	va_start(ap);
86 #endif
87 	vsyslog(pri, fmt, ap);
88 	va_end(ap);
89 }
90 
91 void
92 vsyslog(pri, fmt, ap)
93 	int pri;
94 	register const char *fmt;
95 	va_list ap;
96 {
97 	register int cnt;
98 	register char *p;
99 	time_t now;
100 	int fd, saved_errno;
101 	char *stdp, tbuf[2048], fmt_cpy[1024];
102 
103 #define	INTERNALLOG	LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
104 	/* Check for invalid bits. */
105 	if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
106 		syslog(INTERNALLOG,
107 		    "syslog: unknown facility/priority: %x", pri);
108 		pri &= LOG_PRIMASK|LOG_FACMASK;
109 	}
110 
111 	/* Check priority against setlogmask values. */
112 	if (!LOG_MASK(LOG_PRI(pri)) & LogMask)
113 		return;
114 
115 	saved_errno = errno;
116 
117 	/* set default facility if none specified */
118 	if ((pri & LOG_FACMASK) == 0)
119 		pri |= LogFacility;
120 
121 	/* build the message */
122 	(void)time(&now);
123 	(void)sprintf(tbuf, "<%d>%.15s ", pri, ctime(&now) + 4);
124 	for (p = tbuf; *p; ++p);
125 	if (LogStat & LOG_PERROR)
126 		stdp = p;
127 	if (LogTag) {
128 		(void)strcpy(p, LogTag);
129 		for (; *p; ++p);
130 	}
131 	if (LogStat & LOG_PID) {
132 		(void)sprintf(p, "[%d]", getpid());
133 		for (; *p; ++p);
134 	}
135 	if (LogTag) {
136 		*p++ = ':';
137 		*p++ = ' ';
138 	}
139 
140 	/* substitute error message for %m */
141 	{
142 		register char ch, *t1, *t2;
143 		char *strerror();
144 
145 		for (t1 = fmt_cpy; ch = *fmt; ++fmt)
146 			if (ch == '%' && fmt[1] == 'm') {
147 				++fmt;
148 				for (t2 = strerror(saved_errno);
149 				    *t1 = *t2++; ++t1);
150 			}
151 			else
152 				*t1++ = ch;
153 		*t1 = '\0';
154 	}
155 
156 	(void)vsprintf(p, fmt_cpy, ap);
157 
158 	cnt = strlen(tbuf);
159 
160 	/* output to stderr if requested */
161 	if (LogStat & LOG_PERROR) {
162 		struct iovec iov[2];
163 		register struct iovec *v = iov;
164 
165 		v->iov_base = stdp;
166 		v->iov_len = cnt - (stdp - tbuf);
167 		++v;
168 		v->iov_base = "\n";
169 		v->iov_len = 1;
170 		(void)writev(STDERR_FILENO, iov, 2);
171 	}
172 
173 	/* get connected, output the message to the local logger */
174 	if (!connected)
175 		openlog(LogTag, LogStat | LOG_NDELAY, 0);
176 	if (send(LogFile, tbuf, cnt, 0) >= 0)
177 		return;
178 
179 	/* see if should attempt the console */
180 	if (!(LogStat&LOG_CONS))
181 		return;
182 
183 	/*
184 	 * Output the message to the console; don't worry about blocking,
185 	 * if console blocks everything will.  Make sure the error reported
186 	 * is the one from the syslogd failure.
187 	 */
188 	if ((fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) {
189 		(void)strcat(tbuf, "\r\n");
190 		cnt += 2;
191 		p = strchr(tbuf, '>') + 1;
192 		(void)write(fd, p, cnt - (p - tbuf));
193 		(void)close(fd);
194 	}
195 }
196 
197 static struct sockaddr SyslogAddr;	/* AF_UNIX address of local logger */
198 
199 void
200 openlog(ident, logstat, logfac)
201 	const char *ident;
202 	int logstat, logfac;
203 {
204 	if (ident != NULL)
205 		LogTag = ident;
206 	LogStat = logstat;
207 	if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
208 		LogFacility = logfac;
209 
210 	if (LogFile == -1) {
211 		SyslogAddr.sa_family = AF_UNIX;
212 		(void)strncpy(SyslogAddr.sa_data, _PATH_LOG,
213 		    sizeof(SyslogAddr.sa_data));
214 		if (LogStat & LOG_NDELAY) {
215 			if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
216 				return;
217 			(void)fcntl(LogFile, F_SETFD, 1);
218 		}
219 	}
220 	if (LogFile != -1 && !connected)
221 		if (connect(LogFile, &SyslogAddr, sizeof(SyslogAddr)) == -1) {
222 			(void)close(LogFile);
223 			LogFile = -1;
224 		} else
225 			connected = 1;
226 }
227 
228 void
229 closelog()
230 {
231 	(void)close(LogFile);
232 	LogFile = -1;
233 	connected = 0;
234 }
235 
236 /* setlogmask -- set the log mask level */
237 int
238 setlogmask(pmask)
239 	int pmask;
240 {
241 	int omask;
242 
243 	omask = LogMask;
244 	if (pmask != 0)
245 		LogMask = pmask;
246 	return (omask);
247 }
248