xref: /original-bsd/lib/libc/gen/syslog.c (revision ff2bc52d)
1 /*
2  * Copyright (c) 1983, 1988 Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #if defined(LIBC_SCCS) && !defined(lint)
9 static char sccsid[] = "@(#)syslog.c	5.34 (Berkeley) 06/26/91";
10 #endif /* LIBC_SCCS and not lint */
11 
12 #include <sys/types.h>
13 #include <sys/socket.h>
14 #include <sys/file.h>
15 #include <sys/syslog.h>
16 #include <sys/uio.h>
17 #include <sys/errno.h>
18 #include <netdb.h>
19 #include <string.h>
20 #if __STDC__
21 #include <stdarg.h>
22 #else
23 #include <varargs.h>
24 #endif
25 #include <time.h>
26 #include <unistd.h>
27 #include <paths.h>
28 #include <stdio.h>
29 
30 static int	LogFile = -1;		/* fd for log */
31 static int	connected;		/* have done connect */
32 static int	LogStat = 0;		/* status bits, set by openlog() */
33 static const char *LogTag = "syslog";	/* string to tag the entry with */
34 static int	LogFacility = LOG_USER;	/* default facility code */
35 static int	LogMask = 0xff;		/* mask of priorities to be logged */
36 
37 /*
38  * syslog, vsyslog --
39  *	print message on log file; output is intended for syslogd(8).
40  */
41 void
42 #if __STDC__
43 syslog(int pri, const char *fmt, ...)
44 #else
45 syslog(pri, fmt, va_alist)
46 	int pri;
47 	char *fmt;
48 	va_dcl
49 #endif
50 {
51 	va_list ap;
52 
53 #if __STDC__
54 	va_start(ap, fmt);
55 #else
56 	va_start(ap);
57 #endif
58 	vsyslog(pri, fmt, ap);
59 	va_end(ap);
60 }
61 
62 void
63 vsyslog(pri, fmt, ap)
64 	int pri;
65 	register const char *fmt;
66 	va_list ap;
67 {
68 	register int cnt;
69 	register char *p;
70 	time_t now, time();
71 	int fd, saved_errno;
72 	char tbuf[2048], fmt_cpy[1024], *stdp, *ctime();
73 
74 	/* check for invalid bits or no priority set */
75 	if (!LOG_PRI(pri) || (pri &~ (LOG_PRIMASK|LOG_FACMASK)) ||
76 	    !(LOG_MASK(pri) & LogMask))
77 		return;
78 
79 	saved_errno = errno;
80 
81 	/* set default facility if none specified */
82 	if ((pri & LOG_FACMASK) == 0)
83 		pri |= LogFacility;
84 
85 	/* build the message */
86 	(void)time(&now);
87 	(void)sprintf(tbuf, "<%d>%.15s ", pri, ctime(&now) + 4);
88 	for (p = tbuf; *p; ++p);
89 	if (LogStat & LOG_PERROR)
90 		stdp = p;
91 	if (LogTag) {
92 		(void)strcpy(p, LogTag);
93 		for (; *p; ++p);
94 	}
95 	if (LogStat & LOG_PID) {
96 		(void)sprintf(p, "[%d]", getpid());
97 		for (; *p; ++p);
98 	}
99 	if (LogTag) {
100 		*p++ = ':';
101 		*p++ = ' ';
102 	}
103 
104 	/* substitute error message for %m */
105 	{
106 		register char ch, *t1, *t2;
107 		char *strerror();
108 
109 		for (t1 = fmt_cpy; ch = *fmt; ++fmt)
110 			if (ch == '%' && fmt[1] == 'm') {
111 				++fmt;
112 				for (t2 = strerror(saved_errno);
113 				    *t1 = *t2++; ++t1);
114 			}
115 			else
116 				*t1++ = ch;
117 		*t1 = '\0';
118 	}
119 
120 	(void)vsprintf(p, fmt_cpy, ap);
121 
122 	cnt = strlen(tbuf);
123 
124 	/* output to stderr if requested */
125 	if (LogStat & LOG_PERROR) {
126 		struct iovec iov[2];
127 		register struct iovec *v = iov;
128 
129 		v->iov_base = stdp;
130 		v->iov_len = cnt - (stdp - tbuf);
131 		++v;
132 		v->iov_base = "\n";
133 		v->iov_len = 1;
134 		(void)writev(STDERR_FILENO, iov, 2);
135 	}
136 
137 	/* get connected, output the message to the local logger */
138 	if (!connected)
139 		openlog(LogTag, LogStat | LOG_NDELAY, 0);
140 	if (send(LogFile, tbuf, cnt, 0) >= 0)
141 		return;
142 
143 	/* see if should attempt the console */
144 	if (!(LogStat&LOG_CONS))
145 		return;
146 
147 	/*
148 	 * Output the message to the console; don't worry about blocking,
149 	 * if console blocks everything will.  Make sure the error reported
150 	 * is the one from the syslogd failure.
151 	 */
152 	if ((fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) {
153 		(void)strcat(tbuf, "\r\n");
154 		cnt += 2;
155 		p = index(tbuf, '>') + 1;
156 		(void)write(fd, p, cnt - (p - tbuf));
157 		(void)close(fd);
158 	}
159 }
160 
161 static struct sockaddr SyslogAddr;	/* AF_UNIX address of local logger */
162 
163 void
164 openlog(ident, logstat, logfac)
165 	const char *ident;
166 	int logstat, logfac;
167 {
168 	if (ident != NULL)
169 		LogTag = ident;
170 	LogStat = logstat;
171 	if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
172 		LogFacility = logfac;
173 
174 	if (LogFile == -1) {
175 		SyslogAddr.sa_family = AF_UNIX;
176 		(void)strncpy(SyslogAddr.sa_data, _PATH_LOG,
177 		    sizeof(SyslogAddr.sa_data));
178 		if (LogStat & LOG_NDELAY) {
179 			if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
180 				return;
181 			(void)fcntl(LogFile, F_SETFD, 1);
182 		}
183 	}
184 	if (LogFile != -1 && !connected)
185 		if (connect(LogFile, &SyslogAddr, sizeof(SyslogAddr)) == -1) {
186 			(void)close(LogFile);
187 			LogFile = -1;
188 		} else
189 			connected = 1;
190 }
191 
192 void
193 closelog()
194 {
195 	(void)close(LogFile);
196 	LogFile = -1;
197 	connected = 0;
198 }
199 
200 /* setlogmask -- set the log mask level */
201 setlogmask(pmask)
202 	int pmask;
203 {
204 	int omask;
205 
206 	omask = LogMask;
207 	if (pmask != 0)
208 		LogMask = pmask;
209 	return (omask);
210 }
211