xref: /netbsd-src/lib/libc/gen/syslog.c (revision 61f282557f0bc41c0b762c629a2f4c14be8b7591)
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[] = "@(#)syslog.c	5.34 (Berkeley) 6/26/91";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <sys/types.h>
39 #include <sys/socket.h>
40 #include <sys/file.h>
41 #include <sys/syslog.h>
42 #include <sys/uio.h>
43 #include <sys/errno.h>
44 #include <netdb.h>
45 #include <string.h>
46 #if __STDC__
47 #include <stdarg.h>
48 #else
49 #include <varargs.h>
50 #endif
51 #include <time.h>
52 #include <unistd.h>
53 #include <paths.h>
54 #include <stdio.h>
55 
56 static int	LogFile = -1;		/* fd for log */
57 static int	connected;		/* have done connect */
58 static int	LogStat = 0;		/* status bits, set by openlog() */
59 static const char *LogTag = "syslog";	/* string to tag the entry with */
60 static int	LogFacility = LOG_USER;	/* default facility code */
61 static int	LogMask = 0xff;		/* mask of priorities to be logged */
62 
63 /*
64  * syslog, vsyslog --
65  *	print message on log file; output is intended for syslogd(8).
66  */
67 void
68 #if __STDC__
69 syslog(int pri, const char *fmt, ...)
70 #else
71 syslog(pri, fmt, va_alist)
72 	int pri;
73 	char *fmt;
74 	va_dcl
75 #endif
76 {
77 	va_list ap;
78 
79 #if __STDC__
80 	va_start(ap, fmt);
81 #else
82 	va_start(ap);
83 #endif
84 	vsyslog(pri, fmt, ap);
85 	va_end(ap);
86 }
87 
88 void
89 vsyslog(pri, fmt, ap)
90 	int pri;
91 	register const char *fmt;
92 	va_list ap;
93 {
94 	register int cnt;
95 	register char *p;
96 	time_t now, time();
97 	int fd, saved_errno;
98 	char tbuf[2048], fmt_cpy[1024], *stdp, *ctime();
99 
100 	/* check for invalid bits or no priority set */
101 	if (!LOG_PRI(pri) || (pri &~ (LOG_PRIMASK|LOG_FACMASK)) ||
102 	    !(LOG_MASK(pri) & LogMask))
103 		return;
104 
105 	saved_errno = errno;
106 
107 	/* set default facility if none specified */
108 	if ((pri & LOG_FACMASK) == 0)
109 		pri |= LogFacility;
110 
111 	/* build the message */
112 	(void)time(&now);
113 	(void)sprintf(tbuf, "<%d>%.15s ", pri, ctime(&now) + 4);
114 	for (p = tbuf; *p; ++p);
115 	if (LogStat & LOG_PERROR)
116 		stdp = p;
117 	if (LogTag) {
118 		(void)strcpy(p, LogTag);
119 		for (; *p; ++p);
120 	}
121 	if (LogStat & LOG_PID) {
122 		(void)sprintf(p, "[%d]", getpid());
123 		for (; *p; ++p);
124 	}
125 	if (LogTag) {
126 		*p++ = ':';
127 		*p++ = ' ';
128 	}
129 
130 	/* substitute error message for %m */
131 	{
132 		register char ch, *t1, *t2;
133 		char *strerror();
134 
135 		for (t1 = fmt_cpy; ch = *fmt; ++fmt)
136 			if (ch == '%' && fmt[1] == 'm') {
137 				++fmt;
138 				for (t2 = strerror(saved_errno);
139 				    *t1 = *t2++; ++t1);
140 			}
141 			else
142 				*t1++ = ch;
143 		*t1 = '\0';
144 	}
145 
146 	(void)vsprintf(p, fmt_cpy, ap);
147 
148 	cnt = strlen(tbuf);
149 
150 	/* output to stderr if requested */
151 	if (LogStat & LOG_PERROR) {
152 		struct iovec iov[2];
153 		register struct iovec *v = iov;
154 
155 		v->iov_base = stdp;
156 		v->iov_len = cnt - (stdp - tbuf);
157 		++v;
158 		v->iov_base = "\n";
159 		v->iov_len = 1;
160 		(void)writev(STDERR_FILENO, iov, 2);
161 	}
162 
163 	/* get connected, output the message to the local logger */
164 	if (!connected)
165 		openlog(LogTag, LogStat | LOG_NDELAY, 0);
166 	if (send(LogFile, tbuf, cnt, 0) >= 0)
167 		return;
168 
169 	/* see if should attempt the console */
170 	if (!(LogStat&LOG_CONS))
171 		return;
172 
173 	/*
174 	 * Output the message to the console; don't worry about blocking,
175 	 * if console blocks everything will.  Make sure the error reported
176 	 * is the one from the syslogd failure.
177 	 */
178 	if ((fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) {
179 		(void)strcat(tbuf, "\r\n");
180 		cnt += 2;
181 		p = index(tbuf, '>') + 1;
182 		(void)write(fd, p, cnt - (p - tbuf));
183 		(void)close(fd);
184 	}
185 }
186 
187 static struct sockaddr SyslogAddr;	/* AF_UNIX address of local logger */
188 
189 void
190 openlog(ident, logstat, logfac)
191 	const char *ident;
192 	int logstat, logfac;
193 {
194 	if (ident != NULL)
195 		LogTag = ident;
196 	LogStat = logstat;
197 	if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
198 		LogFacility = logfac;
199 
200 	if (LogFile == -1) {
201 		SyslogAddr.sa_family = AF_UNIX;
202 		(void)strncpy(SyslogAddr.sa_data, _PATH_LOG,
203 		    sizeof(SyslogAddr.sa_data));
204 		if (LogStat & LOG_NDELAY) {
205 			if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
206 				return;
207 			(void)fcntl(LogFile, F_SETFD, 1);
208 		}
209 	}
210 	if (LogFile != -1 && !connected)
211 		if (connect(LogFile, &SyslogAddr, sizeof(SyslogAddr)) == -1) {
212 			(void)close(LogFile);
213 			LogFile = -1;
214 		} else
215 			connected = 1;
216 }
217 
218 void
219 closelog()
220 {
221 	(void)close(LogFile);
222 	LogFile = -1;
223 	connected = 0;
224 }
225 
226 /* setlogmask -- set the log mask level */
227 setlogmask(pmask)
228 	int pmask;
229 {
230 	int omask;
231 
232 	omask = LogMask;
233 	if (pmask != 0)
234 		LogMask = pmask;
235 	return (omask);
236 }
237