xref: /freebsd/lib/libc/gen/syslog.c (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
1 /*
2  * Copyright (c) 1983, 1988, 1993
3  *	The Regents of the University of California.  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	8.4 (Berkeley) 3/18/94";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <sys/types.h>
39 #include <sys/socket.h>
40 #include <sys/syslog.h>
41 #include <sys/uio.h>
42 #include <netdb.h>
43 
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <paths.h>
47 #include <stdio.h>
48 #include <string.h>
49 #include <time.h>
50 #include <unistd.h>
51 
52 #if __STDC__
53 #include <stdarg.h>
54 #else
55 #include <varargs.h>
56 #endif
57 
58 static int	LogFile = -1;		/* fd for log */
59 static int	connected;		/* have done connect */
60 static int	LogStat = 0;		/* status bits, set by openlog() */
61 static const char *LogTag = NULL;	/* string to tag the entry with */
62 static int	LogFacility = LOG_USER;	/* default facility code */
63 static int	LogMask = 0xff;		/* mask of priorities to be logged */
64 extern char	*__progname;		/* Program name, from crt0. */
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 ch, *p, *t;
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 	p = tbuf + sprintf(tbuf, "<%d>", pri);
124 	p += strftime(p, sizeof (tbuf) - (p - tbuf), "%h %e %T ",
125 	    localtime(&now));
126 	if (LogStat & LOG_PERROR)
127 		stdp = p;
128 	if (LogTag == NULL)
129 		LogTag = __progname;
130 	if (LogTag != NULL)
131 		p += sprintf(p, "%s", LogTag);
132 	if (LogStat & LOG_PID)
133 		p += sprintf(p, "[%d]", getpid());
134 	if (LogTag != NULL) {
135 		*p++ = ':';
136 		*p++ = ' ';
137 	}
138 
139 	/* Substitute error message for %m. */
140 	for (t = fmt_cpy; ch = *fmt; ++fmt)
141 		if (ch == '%' && fmt[1] == 'm') {
142 			++fmt;
143 			t += sprintf(t, "%s", strerror(saved_errno));
144 		} else
145 			*t++ = ch;
146 	*t = '\0';
147 
148 	p += vsprintf(p, fmt_cpy, ap);
149 	cnt = p - tbuf;
150 
151 	/* Output to stderr if requested. */
152 	if (LogStat & LOG_PERROR) {
153 		struct iovec iov[2];
154 		register struct iovec *v = iov;
155 
156 		v->iov_base = stdp;
157 		v->iov_len = cnt - (stdp - tbuf);
158 		++v;
159 		v->iov_base = "\n";
160 		v->iov_len = 1;
161 		(void)writev(STDERR_FILENO, iov, 2);
162 	}
163 
164 	/* Get connected, output the message to the local logger. */
165 	if (!connected)
166 		openlog(LogTag, LogStat | LOG_NDELAY, 0);
167 	if (send(LogFile, tbuf, cnt, 0) >= 0)
168 		return;
169 
170 	/*
171 	 * Output the message to the console; don't worry about blocking,
172 	 * if console blocks everything will.  Make sure the error reported
173 	 * is the one from the syslogd failure.
174 	 */
175 	if (LogStat & LOG_CONS &&
176 	    (fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) {
177 		(void)strcat(tbuf, "\r\n");
178 		cnt += 2;
179 		p = index(tbuf, '>') + 1;
180 		(void)write(fd, p, cnt - (p - tbuf));
181 		(void)close(fd);
182 	}
183 }
184 
185 static struct sockaddr SyslogAddr;	/* AF_UNIX address of local logger */
186 
187 void
188 openlog(ident, logstat, logfac)
189 	const char *ident;
190 	int logstat, logfac;
191 {
192 	if (ident != NULL)
193 		LogTag = ident;
194 	LogStat = logstat;
195 	if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
196 		LogFacility = logfac;
197 
198 	if (LogFile == -1) {
199 		SyslogAddr.sa_family = AF_UNIX;
200 		(void)strncpy(SyslogAddr.sa_data, _PATH_LOG,
201 		    sizeof(SyslogAddr.sa_data));
202 		if (LogStat & LOG_NDELAY) {
203 			if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
204 				return;
205 			(void)fcntl(LogFile, F_SETFD, 1);
206 		}
207 	}
208 	if (LogFile != -1 && !connected)
209 		if (connect(LogFile, &SyslogAddr, sizeof(SyslogAddr)) == -1) {
210 			(void)close(LogFile);
211 			LogFile = -1;
212 		} else
213 			connected = 1;
214 }
215 
216 void
217 closelog()
218 {
219 	(void)close(LogFile);
220 	LogFile = -1;
221 	connected = 0;
222 }
223 
224 /* setlogmask -- set the log mask level */
225 int
226 setlogmask(pmask)
227 	int pmask;
228 {
229 	int omask;
230 
231 	omask = LogMask;
232 	if (pmask != 0)
233 		LogMask = pmask;
234 	return (omask);
235 }
236