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 /*
35 * SYSLOG -- print message on log file
36 *
37 * This routine looks a lot like printf, except that it outputs to the
38 * log file instead of the standard output. Also:
39 * adds a timestamp,
40 * prints the module name in front of the message,
41 * has some other formatting types (or will sometime),
42 * adds a newline on the end of the message.
43 *
44 * The output of this routine is intended to be read by syslogd(8).
45 *
46 * Author: Eric Allman
47 * Modified to use UNIX domain IPC by Ralph Campbell
48 * Patched March 12, 1996 by A. Ian Vogelesang <vogelesang@hdshq.com>
49 * - to correct the handling of message & format string truncation,
50 * - to visibly tag truncated records to facilitate
51 * investigation of such Bad Things with grep, and,
52 * - to correct the handling of case where "write"
53 * returns after writing only part of the message.
54 * Rewritten by Martin Mares <mj@atrey.karlin.mff.cuni.cz> on May 14, 1997
55 * - better buffer overrun checks.
56 * - special handling of "%m" removed as we use GNU sprintf which handles
57 * it automatically.
58 * - Major code cleanup.
59 */
60
61 #include <sys/types.h>
62 #include <sys/socket.h>
63 #include <sys/file.h>
64 #include <sys/signal.h>
65 #include <sys/syslog.h>
66
67 #include <sys/uio.h>
68 #include <sys/wait.h>
69 #include <netdb.h>
70 #include <string.h>
71 #include <time.h>
72 #include <unistd.h>
73 #include <errno.h>
74 #include <stdarg.h>
75 #include <paths.h>
76 #include <stdio.h>
77 #include <ctype.h>
78 #include <signal.h>
79
80
81 #include <bits/uClibc_mutex.h>
82
83 __UCLIBC_MUTEX_STATIC(mylock, PTHREAD_MUTEX_INITIALIZER);
84
85
86 /* !glibc_compat: glibc uses argv[0] by default
87 * (default: if there was no openlog or if openlog passed NULL),
88 * not string "syslog"
89 */
90 static const char *LogTag = "syslog"; /* string to tag the entry with */
91 static int LogFile = -1; /* fd for log */
92 static smalluint connected; /* have done connect */
93 /* all bits in option argument for openlog fit in 8 bits */
94 static smalluint LogStat = 0; /* status bits, set by openlog */
95 /* default facility code if openlog is not called */
96 /* (this fits in 8 bits even without >> 3 shift, but playing extra safe) */
97 static smalluint LogFacility = LOG_USER >> 3;
98 /* bits mask of priorities to be logged (eight prios - 8 bits is enough) */
99 static smalluint LogMask = 0xff;
100 /* AF_UNIX address of local logger (we use struct sockaddr
101 * instead of struct sockaddr_un since "/dev/log" is small enough) */
102 static const struct sockaddr SyslogAddr = {
103 .sa_family = AF_UNIX, /* sa_family_t (usually a short) */
104 .sa_data = _PATH_LOG /* char [14] */
105 };
106
107 static void
closelog_intern(int sig)108 closelog_intern(int sig)
109 {
110 /* mylock must be held by the caller */
111 if (LogFile != -1) {
112 (void) close(LogFile);
113 }
114 LogFile = -1;
115 connected = 0;
116 if (sig == 0) { /* called from closelog()? - reset to defaults */
117 LogStat = 0;
118 LogTag = "syslog";
119 LogFacility = LOG_USER >> 3;
120 LogMask = 0xff;
121 }
122 }
123
124 static void
openlog_intern(void)125 openlog_intern(void)
126 {
127 int fd;
128 int logType = SOCK_DGRAM;
129 static const struct timeval tv = { 1, 0 };
130
131 fd = LogFile;
132 if (fd == -1) {
133 retry:
134 if (1) { /* if statement left in to make .diff cleaner */
135 LogFile = fd = socket(AF_UNIX, logType, 0);
136 if (fd == -1) {
137 return;
138 }
139 fcntl(fd, F_SETFD, FD_CLOEXEC);
140 /* We don't want to block if e.g. syslogd is SIGSTOPed */
141 fcntl(fd, F_SETFL, O_NONBLOCK | fcntl(fd, F_GETFL));
142 }
143 }
144
145 if (fd != -1 && !connected) {
146 if (connect(fd, &SyslogAddr, sizeof(SyslogAddr)) != -1) {
147 /* We want to block send if e.g. syslogd is SIGSTOPed */
148 fcntl(fd, F_SETFL, ~O_NONBLOCK & fcntl(fd, F_GETFL));
149 setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));
150 connected = 1;
151 } else {
152 if (fd != -1) {
153 close(fd);
154 LogFile = fd = -1;
155 }
156 if (logType == SOCK_DGRAM) {
157 logType = SOCK_STREAM;
158 goto retry;
159 }
160 }
161 }
162 }
163
164 /*
165 * OPENLOG -- open system log
166 */
167 void
openlog(const char * ident,int logstat,int logfac)168 openlog(const char *ident, int logstat, int logfac)
169 {
170 __UCLIBC_MUTEX_LOCK(mylock);
171
172 if (ident != NULL)
173 LogTag = ident;
174 LogStat = logstat;
175 /* (we were checking also for logfac != 0, but it breaks
176 * openlog(xx, LOG_KERN) since LOG_KERN == 0) */
177 if ((logfac & ~LOG_FACMASK) == 0) /* if we don't have invalid bits */
178 LogFacility = (unsigned)logfac >> 3;
179
180 if (logstat & LOG_NDELAY)
181 openlog_intern();
182
183 __UCLIBC_MUTEX_UNLOCK(mylock);
184 }
185
186 /*
187 * syslog, vsyslog --
188 * print message on log file; output is intended for syslogd(8).
189 */
190 static
191 #ifndef __USE_BSD
192 __always_inline
193 #endif
194 void
__vsyslog(int pri,const char * fmt,va_list ap)195 __vsyslog(int pri, const char *fmt, va_list ap)
196 {
197 register char *p;
198 char *last_chr, *head_end, *end, *stdp;
199 time_t now;
200 int fd, saved_errno;
201 int rc;
202 char tbuf[1024]; /* syslogd is unable to handle longer messages */
203
204 /* Just throw out this message if pri has bad bits. */
205 if ((pri & ~(LOG_PRIMASK|LOG_FACMASK)) != 0)
206 return;
207
208 saved_errno = errno;
209
210 __UCLIBC_MUTEX_LOCK(mylock);
211
212 /* See if we should just throw out this message according to LogMask. */
213 if ((LogMask & LOG_MASK(LOG_PRI(pri))) == 0)
214 goto getout;
215 if (LogFile < 0 || !connected)
216 openlog_intern();
217
218 /* Set default facility if none specified. */
219 if ((pri & LOG_FACMASK) == 0)
220 pri |= ((int)LogFacility << 3);
221
222 /* Build the message. We know the starting part of the message can take
223 * no longer than 64 characters plus length of the LogTag. So it's
224 * safe to test only LogTag and use normal sprintf everywhere else.
225 */
226 (void)time(&now);
227 stdp = p = tbuf + sprintf(tbuf, "<%d>%.15s ", pri, ctime(&now) + 4);
228 /*if (LogTag) - always true */ {
229 if (strlen(LogTag) < sizeof(tbuf) - 64)
230 p += sprintf(p, "%s", LogTag);
231 else
232 p += sprintf(p, "<BUFFER OVERRUN ATTEMPT>");
233 }
234 if (LogStat & LOG_PID)
235 p += sprintf(p, "[%d]", getpid());
236 /*if (LogTag) - always true */ {
237 *p++ = ':';
238 *p++ = ' ';
239 }
240 head_end = p;
241
242 /* We format the rest of the message. If the buffer becomes full, we mark
243 * the message as truncated. Note that we require at least 2 free bytes
244 * in the buffer as we might want to add "\r\n" there.
245 */
246
247 end = tbuf + sizeof(tbuf) - 1;
248 __set_errno(saved_errno);
249 p += vsnprintf(p, end - p, fmt, ap);
250 if (p >= end || p < head_end) { /* Returned -1 in case of error... */
251 static const char truncate_msg[12] = "[truncated] "; /* no NUL! */
252 memmove(head_end + sizeof(truncate_msg), head_end,
253 end - head_end - sizeof(truncate_msg));
254 memcpy(head_end, truncate_msg, sizeof(truncate_msg));
255 if (p < head_end) {
256 while (p < end && *p) {
257 p++;
258 }
259 }
260 else {
261 p = end - 1;
262 }
263
264 }
265 last_chr = p;
266
267 /* Output to stderr if requested. */
268 if (LogStat & LOG_PERROR) {
269 *last_chr = '\n';
270 (void)write(STDERR_FILENO, stdp, last_chr - stdp + 1);
271 }
272
273 /* Output the message to the local logger using NUL as a message delimiter. */
274 p = tbuf;
275 *last_chr = '\0';
276 retry:
277 if (LogFile >= 0) {
278 do {
279 /* can't just use write, it can result in SIGPIPE */
280 rc = send(LogFile, p, last_chr + 1 - p, MSG_NOSIGNAL);
281 if (rc < 0) {
282 switch (errno) {
283 case EINTR:
284 break;
285 case ECONNRESET:
286 /* syslogd restarted, reopen log */
287 closelog_intern(1);
288 openlog_intern();
289 goto retry;
290 case EAGAIN:
291 /* syslogd stalled, noting we can do */
292 default:
293 closelog_intern(1); /* 1: do not reset LogXXX globals to default */
294 goto write_err;
295 }
296 rc = 0;
297 }
298 p += rc;
299 } while (p <= last_chr);
300 goto getout;
301 }
302
303 write_err:
304 /*
305 * Output the message to the console; don't worry about blocking,
306 * if console blocks everything will. Make sure the error reported
307 * is the one from the syslogd failure.
308 */
309 /* should mode be O_WRONLY | O_NOCTTY? -- Uli */
310 /* yes, but in Linux "/dev/console" never becomes ctty anyway -- vda */
311 if ((LogStat & LOG_CONS) &&
312 (fd = open(_PATH_CONSOLE, O_WRONLY | O_NOCTTY)) >= 0) {
313 p = strchr(tbuf, '>') + 1;
314 last_chr[0] = '\r';
315 last_chr[1] = '\n';
316 (void)write(fd, p, last_chr - p + 2);
317 (void)close(fd);
318 }
319
320 getout:
321 __UCLIBC_MUTEX_UNLOCK(mylock);
322 }
323 #ifdef __USE_BSD
strong_alias(__vsyslog,vsyslog)324 strong_alias(__vsyslog,vsyslog)
325 #endif
326
327 void
328 syslog(int pri, const char *fmt, ...)
329 {
330 va_list ap;
331
332 va_start(ap, fmt);
333 __vsyslog(pri, fmt, ap);
334 va_end(ap);
335 }
libc_hidden_def(syslog)336 libc_hidden_def(syslog)
337
338 /*
339 * CLOSELOG -- close the system log
340 */
341 void
342 closelog(void)
343 {
344 __UCLIBC_MUTEX_LOCK(mylock);
345 closelog_intern(0); /* 0: reset LogXXX globals to default */
346 __UCLIBC_MUTEX_UNLOCK(mylock);
347 }
348
349 /* setlogmask -- set the log mask level */
setlogmask(int pmask)350 int setlogmask(int pmask)
351 {
352 int omask;
353
354 omask = LogMask;
355 if (pmask != 0) {
356 /* __UCLIBC_MUTEX_LOCK(mylock);*/
357 LogMask = pmask;
358 /* __UCLIBC_MUTEX_UNLOCK(mylock);*/
359 }
360 return omask;
361 }
362