xref: /netbsd-src/lib/libc/gen/syslog.c (revision 1f2744e6e4915c9da2a3f980279398c4cf7d5e6d)
1 /*	$NetBSD: syslog.c,v 1.7 1995/03/04 01:56:12 cgd Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)syslog.c	8.4 (Berkeley) 3/18/94";
39 #else
40 static char rcsid[] = "$NetBSD: syslog.c,v 1.7 1995/03/04 01:56:12 cgd Exp $";
41 #endif
42 #endif /* LIBC_SCCS and not lint */
43 
44 #include <sys/types.h>
45 #include <sys/socket.h>
46 #include <sys/syslog.h>
47 #include <sys/uio.h>
48 #include <netdb.h>
49 
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <paths.h>
53 #include <stdio.h>
54 #include <string.h>
55 #include <time.h>
56 #include <unistd.h>
57 
58 #if __STDC__
59 #include <stdarg.h>
60 #else
61 #include <varargs.h>
62 #endif
63 
64 static int	LogFile = -1;		/* fd for log */
65 static int	connected;		/* have done connect */
66 static int	LogStat = 0;		/* status bits, set by openlog() */
67 static const char *LogTag = NULL;	/* string to tag the entry with */
68 static int	LogFacility = LOG_USER;	/* default facility code */
69 static int	LogMask = 0xff;		/* mask of priorities to be logged */
70 extern char	*__progname;		/* Program name, from crt0. */
71 
72 /*
73  * syslog, vsyslog --
74  *	print message on log file; output is intended for syslogd(8).
75  */
76 void
77 #if __STDC__
78 syslog(int pri, const char *fmt, ...)
79 #else
80 syslog(pri, fmt, va_alist)
81 	int pri;
82 	char *fmt;
83 	va_dcl
84 #endif
85 {
86 	va_list ap;
87 
88 #if __STDC__
89 	va_start(ap, fmt);
90 #else
91 	va_start(ap);
92 #endif
93 	vsyslog(pri, fmt, ap);
94 	va_end(ap);
95 }
96 
97 void
98 vsyslog(pri, fmt, ap)
99 	int pri;
100 	register const char *fmt;
101 	va_list ap;
102 {
103 	register int cnt;
104 	register char ch, *p, *t;
105 	time_t now;
106 	int fd, saved_errno;
107 	char *stdp, tbuf[2048], fmt_cpy[1024];
108 
109 #define	INTERNALLOG	LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
110 	/* Check for invalid bits. */
111 	if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
112 		syslog(INTERNALLOG,
113 		    "syslog: unknown facility/priority: %x", pri);
114 		pri &= LOG_PRIMASK|LOG_FACMASK;
115 	}
116 
117 	/* Check priority against setlogmask values. */
118 	if (!LOG_MASK(LOG_PRI(pri)) & LogMask)
119 		return;
120 
121 	saved_errno = errno;
122 
123 	/* Set default facility if none specified. */
124 	if ((pri & LOG_FACMASK) == 0)
125 		pri |= LogFacility;
126 
127 	/* Build the message. */
128 	(void)time(&now);
129 	p = tbuf + sprintf(tbuf, "<%d>", pri);
130 	p += strftime(p, sizeof (tbuf) - (p - tbuf), "%h %e %T ",
131 	    localtime(&now));
132 	if (LogStat & LOG_PERROR)
133 		stdp = p;
134 	if (LogTag == NULL)
135 		LogTag = __progname;
136 	if (LogTag != NULL)
137 		p += sprintf(p, "%s", LogTag);
138 	if (LogStat & LOG_PID)
139 		p += sprintf(p, "[%d]", getpid());
140 	if (LogTag != NULL) {
141 		*p++ = ':';
142 		*p++ = ' ';
143 	}
144 
145 	/* Substitute error message for %m. */
146 	for (t = fmt_cpy; ch = *fmt; ++fmt)
147 		if (ch == '%' && fmt[1] == 'm') {
148 			++fmt;
149 			t += sprintf(t, "%s", strerror(saved_errno));
150 		} else
151 			*t++ = ch;
152 	*t = '\0';
153 
154 	p += vsprintf(p, fmt_cpy, ap);
155 	cnt = p - tbuf;
156 
157 	/* Output to stderr if requested. */
158 	if (LogStat & LOG_PERROR) {
159 		struct iovec iov[2];
160 		register struct iovec *v = iov;
161 
162 		v->iov_base = stdp;
163 		v->iov_len = cnt - (stdp - tbuf);
164 		++v;
165 		v->iov_base = "\n";
166 		v->iov_len = 1;
167 		(void)writev(STDERR_FILENO, iov, 2);
168 	}
169 
170 	/* Get connected, output the message to the local logger. */
171 	if (!connected)
172 		openlog(LogTag, LogStat | LOG_NDELAY, 0);
173 	if (send(LogFile, tbuf, cnt, 0) >= 0)
174 		return;
175 
176 	/*
177 	 * Output the message to the console; don't worry about blocking,
178 	 * if console blocks everything will.  Make sure the error reported
179 	 * is the one from the syslogd failure.
180 	 */
181 	if (LogStat & LOG_CONS &&
182 	    (fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) {
183 		(void)strcat(tbuf, "\r\n");
184 		cnt += 2;
185 		p = strchr(tbuf, '>') + 1;
186 		(void)write(fd, p, cnt - (p - tbuf));
187 		(void)close(fd);
188 	}
189 }
190 
191 static struct sockaddr SyslogAddr;	/* AF_UNIX address of local logger */
192 
193 void
194 openlog(ident, logstat, logfac)
195 	const char *ident;
196 	int logstat, logfac;
197 {
198 	if (ident != NULL)
199 		LogTag = ident;
200 	LogStat = logstat;
201 	if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
202 		LogFacility = logfac;
203 
204 	if (LogFile == -1) {
205 		SyslogAddr.sa_family = AF_UNIX;
206 		(void)strncpy(SyslogAddr.sa_data, _PATH_LOG,
207 		    sizeof(SyslogAddr.sa_data));
208 		if (LogStat & LOG_NDELAY) {
209 			if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
210 				return;
211 			(void)fcntl(LogFile, F_SETFD, 1);
212 		}
213 	}
214 	if (LogFile != -1 && !connected)
215 		if (connect(LogFile, &SyslogAddr, sizeof(SyslogAddr)) == -1) {
216 			(void)close(LogFile);
217 			LogFile = -1;
218 		} else
219 			connected = 1;
220 }
221 
222 void
223 closelog()
224 {
225 	(void)close(LogFile);
226 	LogFile = -1;
227 	connected = 0;
228 }
229 
230 /* setlogmask -- set the log mask level */
231 int
232 setlogmask(pmask)
233 	int pmask;
234 {
235 	int omask;
236 
237 	omask = LogMask;
238 	if (pmask != 0)
239 		LogMask = pmask;
240 	return (omask);
241 }
242