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 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31static char sccsid[] = "@(#)syslog.c 8.4 (Berkeley) 3/18/94";
32#endif /* LIBC_SCCS and not lint */
33
34#include <sys/types.h>
35#include <sys/socket.h>
36#include <sys/syslog.h>
37#include <sys/uio.h>
38#include <sys/un.h>
39#include <netdb.h>
40
41#include <errno.h>
42#include <fcntl.h>
43#include <paths.h>
44#include <stdio.h>
45#include <stdio_ext.h>
46#include <string.h>
47#include <time.h>
48#include <unistd.h>
49#include <stdlib.h>
50#include <libc-lock.h>
51#include <signal.h>
52#include <locale.h>
53
54#include <stdarg.h>
55
56#include <libio/iolibio.h>
57#include <math_ldbl_opt.h>
58
59#include <kernel-features.h>
60
61#define ftell(s) _IO_ftell (s)
62
63static int LogType = SOCK_DGRAM; /* type of socket connection */
64static int LogFile = -1; /* fd for log */
65static int connected; /* have done connect */
66static int LogStat; /* status bits, set by openlog() */
67static const char *LogTag; /* string to tag the entry with */
68static int LogFacility = LOG_USER; /* default facility code */
69static int LogMask = 0xff; /* mask of priorities to be logged */
70extern char *__progname; /* Program name, from crt0. */
71
72/* Define the lock. */
73__libc_lock_define_initialized (static, syslog_lock)
74
75static void openlog_internal(const char *, int, int) internal_function;
76static void closelog_internal(void);
77#ifndef NO_SIGPIPE
78static void sigpipe_handler (int);
79#endif
80
81#ifndef send_flags
82# define send_flags 0
83#endif
84
85struct cleanup_arg
86{
87 void *buf;
88 struct sigaction *oldaction;
89};
90
91static void
92cancel_handler (void *ptr)
93{
94#ifndef NO_SIGPIPE
95 /* Restore the old signal handler. */
96 struct cleanup_arg *clarg = (struct cleanup_arg *) ptr;
97
98 if (clarg != NULL && clarg->oldaction != NULL)
99 __sigaction (SIGPIPE, clarg->oldaction, NULL);
100#endif
101
102 /* Free the lock. */
103 __libc_lock_unlock (syslog_lock);
104}
105
106
107/*
108 * syslog, vsyslog --
109 * print message on log file; output is intended for syslogd(8).
110 */
111void
112__syslog(int pri, const char *fmt, ...)
113{
114 va_list ap;
115
116 va_start(ap, fmt);
117 __vsyslog_chk(pri, -1, fmt, ap);
118 va_end(ap);
119}
120ldbl_hidden_def (__syslog, syslog)
121ldbl_strong_alias (__syslog, syslog)
122
123void
124__syslog_chk(int pri, int flag, const char *fmt, ...)
125{
126 va_list ap;
127
128 va_start(ap, fmt);
129 __vsyslog_chk(pri, flag, fmt, ap);
130 va_end(ap);
131}
132
133void
134__vsyslog_chk(int pri, int flag, const char *fmt, va_list ap)
135{
136 struct tm now_tm;
137 time_t now;
138 int fd;
139 FILE *f;
140 char *buf = 0;
141 size_t bufsize = 0;
142 size_t msgoff;
143#ifndef NO_SIGPIPE
144 struct sigaction action, oldaction;
145 int sigpipe;
146#endif
147 int saved_errno = errno;
148 char failbuf[3 * sizeof (pid_t) + sizeof "out of memory []"];
149
150#define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
151 /* Check for invalid bits. */
152 if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
153 syslog(INTERNALLOG,
154 "syslog: unknown facility/priority: %x", pri);
155 pri &= LOG_PRIMASK|LOG_FACMASK;
156 }
157
158 /* Check priority against setlogmask values. */
159 if ((LOG_MASK (LOG_PRI (pri)) & LogMask) == 0)
160 return;
161
162 /* Set default facility if none specified. */
163 if ((pri & LOG_FACMASK) == 0)
164 pri |= LogFacility;
165
166 /* Build the message in a memory-buffer stream. */
167 f = __open_memstream (&buf, &bufsize);
168 if (f == NULL)
169 {
170 /* We cannot get a stream. There is not much we can do but
171 emitting an error messages. */
172 char numbuf[3 * sizeof (pid_t)];
173 char *nump;
174 char *endp = __stpcpy (failbuf, "out of memory [");
175 pid_t pid = __getpid ();
176
177 nump = numbuf + sizeof (numbuf);
178 /* The PID can never be zero. */
179 do
180 *--nump = '0' + pid % 10;
181 while ((pid /= 10) != 0);
182
183 endp = __mempcpy (endp, nump, (numbuf + sizeof (numbuf)) - nump);
184 *endp++ = ']';
185 *endp = '\0';
186 buf = failbuf;
187 bufsize = endp - failbuf;
188 msgoff = 0;
189 }
190 else
191 {
192 __fsetlocking (f, FSETLOCKING_BYCALLER);
193 fprintf (f, "<%d>", pri);
194 (void) time (&now);
195 f->_IO_write_ptr += __strftime_l (f->_IO_write_ptr,
196 f->_IO_write_end
197 - f->_IO_write_ptr,
198 "%h %e %T ",
199 __localtime_r (&now, &now_tm),
200 _nl_C_locobj_ptr);
201 msgoff = ftell (f);
202 if (LogTag == NULL)
203 LogTag = __progname;
204 if (LogTag != NULL)
205 __fputs_unlocked (LogTag, f);
206 if (LogStat & LOG_PID)
207 fprintf (f, "[%d]", (int) __getpid ());
208 if (LogTag != NULL)
209 {
210 putc_unlocked (':', f);
211 putc_unlocked (' ', f);
212 }
213
214 /* Restore errno for %m format. */
215 __set_errno (saved_errno);
216
217 /* We have the header. Print the user's format into the
218 buffer. */
219 if (flag == -1)
220 vfprintf (f, fmt, ap);
221 else
222 __vfprintf_chk (f, flag, fmt, ap);
223
224 /* Close the memory stream; this will finalize the data
225 into a malloc'd buffer in BUF. */
226 fclose (f);
227 }
228
229 /* Output to stderr if requested. */
230 if (LogStat & LOG_PERROR) {
231 struct iovec iov[2];
232 struct iovec *v = iov;
233
234 v->iov_base = buf + msgoff;
235 v->iov_len = bufsize - msgoff;
236 /* Append a newline if necessary. */
237 if (buf[bufsize - 1] != '\n')
238 {
239 ++v;
240 v->iov_base = (char *) "\n";
241 v->iov_len = 1;
242 }
243
244 __libc_cleanup_push (free, buf == failbuf ? NULL : buf);
245
246 /* writev is a cancellation point. */
247 (void)__writev(STDERR_FILENO, iov, v - iov + 1);
248
249 __libc_cleanup_pop (0);
250 }
251
252 /* Prepare for multiple users. We have to take care: open and
253 write are cancellation points. */
254 struct cleanup_arg clarg;
255 clarg.buf = buf;
256 clarg.oldaction = NULL;
257 __libc_cleanup_push (cancel_handler, &clarg);
258 __libc_lock_lock (syslog_lock);
259
260#ifndef NO_SIGPIPE
261 /* Prepare for a broken connection. */
262 memset (&action, 0, sizeof (action));
263 action.sa_handler = sigpipe_handler;
264 sigemptyset (&action.sa_mask);
265 sigpipe = __sigaction (SIGPIPE, &action, &oldaction);
266 if (sigpipe == 0)
267 clarg.oldaction = &oldaction;
268#endif
269
270 /* Get connected, output the message to the local logger. */
271 if (!connected)
272 openlog_internal(LogTag, LogStat | LOG_NDELAY, 0);
273
274 /* If we have a SOCK_STREAM connection, also send ASCII NUL as
275 a record terminator. */
276 if (LogType == SOCK_STREAM)
277 ++bufsize;
278
279 if (!connected || __send(LogFile, buf, bufsize, send_flags) < 0)
280 {
281 if (connected)
282 {
283 /* Try to reopen the syslog connection. Maybe it went
284 down. */
285 closelog_internal ();
286 openlog_internal(LogTag, LogStat | LOG_NDELAY, 0);
287 }
288
289 if (!connected || __send(LogFile, buf, bufsize, send_flags) < 0)
290 {
291 closelog_internal (); /* attempt re-open next time */
292 /*
293 * Output the message to the console; don't worry
294 * about blocking, if console blocks everything will.
295 * Make sure the error reported is the one from the
296 * syslogd failure.
297 */
298 if (LogStat & LOG_CONS &&
299 (fd = __open(_PATH_CONSOLE, O_WRONLY|O_NOCTTY, 0)) >= 0)
300 {
301 __dprintf (fd, "%s\r\n", buf + msgoff);
302 (void)__close(fd);
303 }
304 }
305 }
306
307#ifndef NO_SIGPIPE
308 if (sigpipe == 0)
309 __sigaction (SIGPIPE, &oldaction, (struct sigaction *) NULL);
310#endif
311
312 /* End of critical section. */
313 __libc_cleanup_pop (0);
314 __libc_lock_unlock (syslog_lock);
315
316 if (buf != failbuf)
317 free (buf);
318}
319libc_hidden_def (__vsyslog_chk)
320
321void
322__vsyslog(int pri, const char *fmt, va_list ap)
323{
324 __vsyslog_chk (pri, -1, fmt, ap);
325}
326ldbl_hidden_def (__vsyslog, vsyslog)
327ldbl_weak_alias (__vsyslog, vsyslog)
328
329static struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */
330
331
332static void
333internal_function
334openlog_internal(const char *ident, int logstat, int logfac)
335{
336 if (ident != NULL)
337 LogTag = ident;
338 LogStat = logstat;
339 if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
340 LogFacility = logfac;
341
342 int retry = 0;
343 while (retry < 2) {
344 if (LogFile == -1) {
345 SyslogAddr.sun_family = AF_UNIX;
346 (void)strncpy(SyslogAddr.sun_path, _PATH_LOG,
347 sizeof(SyslogAddr.sun_path));
348 if (LogStat & LOG_NDELAY) {
349 LogFile = __socket(AF_UNIX, LogType | SOCK_CLOEXEC, 0);
350 if (LogFile == -1)
351 return;
352 }
353 }
354 if (LogFile != -1 && !connected)
355 {
356 int old_errno = errno;
357 if (__connect(LogFile, &SyslogAddr, sizeof(SyslogAddr))
358 == -1)
359 {
360 int saved_errno = errno;
361 int fd = LogFile;
362 LogFile = -1;
363 (void)__close(fd);
364 __set_errno (old_errno);
365 if (saved_errno == EPROTOTYPE)
366 {
367 /* retry with the other type: */
368 LogType = (LogType == SOCK_DGRAM
369 ? SOCK_STREAM : SOCK_DGRAM);
370 ++retry;
371 continue;
372 }
373 } else
374 connected = 1;
375 }
376 break;
377 }
378}
379
380void
381openlog (const char *ident, int logstat, int logfac)
382{
383 /* Protect against multiple users and cancellation. */
384 __libc_cleanup_push (cancel_handler, NULL);
385 __libc_lock_lock (syslog_lock);
386
387 openlog_internal (ident, logstat, logfac);
388
389 __libc_cleanup_pop (1);
390}
391
392#ifndef NO_SIGPIPE
393static void
394sigpipe_handler (int signo)
395{
396 closelog_internal ();
397}
398#endif
399
400static void
401closelog_internal (void)
402{
403 if (!connected)
404 return;
405
406 __close (LogFile);
407 LogFile = -1;
408 connected = 0;
409}
410
411void
412closelog (void)
413{
414 /* Protect against multiple users and cancellation. */
415 __libc_cleanup_push (cancel_handler, NULL);
416 __libc_lock_lock (syslog_lock);
417
418 closelog_internal ();
419 LogTag = NULL;
420 LogType = SOCK_DGRAM; /* this is the default */
421
422 /* Free the lock. */
423 __libc_cleanup_pop (1);
424}
425
426/* setlogmask -- set the log mask level */
427int
428setlogmask (int pmask)
429{
430 int omask;
431
432 omask = LogMask;
433 if (pmask != 0)
434 LogMask = pmask;
435 return (omask);
436}
437