1 /* $OpenBSD: log.c,v 1.45 2013/05/16 09:08:41 dtucker Exp $ */
2 /*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 *
7 * As far as I am concerned, the code I have written for this software
8 * can be used freely for any purpose. Any derived versions of this
9 * software must be clearly marked as such, and if the derived work is
10 * incompatible with the protocol description in the RFC file, it must be
11 * called by a name other than "ssh" or "Secure Shell".
12 */
13 /*
14 * Copyright (c) 2000 Markus Friedl. All rights reserved.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36
37 #include "includes.h"
38
39 #include <sys/types.h>
40
41 #include <fcntl.h>
42 #include <stdarg.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <syslog.h>
47 #include <unistd.h>
48 #include <errno.h>
49 #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
50 # include <vis.h>
51 #endif
52
53 #include "xmalloc.h"
54 #include "log.h"
55
56 static LogLevel log_level = SYSLOG_LEVEL_INFO;
57 static int log_on_stderr = 1;
58 static int log_stderr_fd = STDERR_FILENO;
59 static int log_facility = LOG_AUTH;
60 static char *argv0;
61 static log_handler_fn *log_handler;
62 static void *log_handler_ctx;
63
64 extern char *__progname;
65
66 #define LOG_SYSLOG_VIS (VIS_CSTYLE|VIS_NL|VIS_TAB|VIS_OCTAL)
67 #define LOG_STDERR_VIS (VIS_SAFE|VIS_OCTAL)
68
69 /* textual representation of log-facilities/levels */
70
71 static struct {
72 const char *name;
73 SyslogFacility val;
74 } log_facilities[] = {
75 { "DAEMON", SYSLOG_FACILITY_DAEMON },
76 { "USER", SYSLOG_FACILITY_USER },
77 { "AUTH", SYSLOG_FACILITY_AUTH },
78 #ifdef LOG_AUTHPRIV
79 { "AUTHPRIV", SYSLOG_FACILITY_AUTHPRIV },
80 #endif
81 { "LOCAL0", SYSLOG_FACILITY_LOCAL0 },
82 { "LOCAL1", SYSLOG_FACILITY_LOCAL1 },
83 { "LOCAL2", SYSLOG_FACILITY_LOCAL2 },
84 { "LOCAL3", SYSLOG_FACILITY_LOCAL3 },
85 { "LOCAL4", SYSLOG_FACILITY_LOCAL4 },
86 { "LOCAL5", SYSLOG_FACILITY_LOCAL5 },
87 { "LOCAL6", SYSLOG_FACILITY_LOCAL6 },
88 { "LOCAL7", SYSLOG_FACILITY_LOCAL7 },
89 { NULL, SYSLOG_FACILITY_NOT_SET }
90 };
91
92 static struct {
93 const char *name;
94 LogLevel val;
95 } log_levels[] =
96 {
97 { "QUIET", SYSLOG_LEVEL_QUIET },
98 { "FATAL", SYSLOG_LEVEL_FATAL },
99 { "ERROR", SYSLOG_LEVEL_ERROR },
100 { "INFO", SYSLOG_LEVEL_INFO },
101 { "VERBOSE", SYSLOG_LEVEL_VERBOSE },
102 { "DEBUG", SYSLOG_LEVEL_DEBUG1 },
103 { "DEBUG1", SYSLOG_LEVEL_DEBUG1 },
104 { "DEBUG2", SYSLOG_LEVEL_DEBUG2 },
105 { "DEBUG3", SYSLOG_LEVEL_DEBUG3 },
106 { NULL, SYSLOG_LEVEL_NOT_SET }
107 };
108
109 SyslogFacility
log_facility_number(char * name)110 log_facility_number(char *name)
111 {
112 int i;
113
114 if (name != NULL)
115 for (i = 0; log_facilities[i].name; i++)
116 if (strcasecmp(log_facilities[i].name, name) == 0)
117 return log_facilities[i].val;
118 return SYSLOG_FACILITY_NOT_SET;
119 }
120
121 const char *
log_facility_name(SyslogFacility facility)122 log_facility_name(SyslogFacility facility)
123 {
124 u_int i;
125
126 for (i = 0; log_facilities[i].name; i++)
127 if (log_facilities[i].val == facility)
128 return log_facilities[i].name;
129 return NULL;
130 }
131
132 LogLevel
log_level_number(char * name)133 log_level_number(char *name)
134 {
135 int i;
136
137 if (name != NULL)
138 for (i = 0; log_levels[i].name; i++)
139 if (strcasecmp(log_levels[i].name, name) == 0)
140 return log_levels[i].val;
141 return SYSLOG_LEVEL_NOT_SET;
142 }
143
144 const char *
log_level_name(LogLevel level)145 log_level_name(LogLevel level)
146 {
147 u_int i;
148
149 for (i = 0; log_levels[i].name != NULL; i++)
150 if (log_levels[i].val == level)
151 return log_levels[i].name;
152 return NULL;
153 }
154
155 /* Error messages that should be logged. */
156
157 void
error(const char * fmt,...)158 error(const char *fmt,...)
159 {
160 va_list args;
161
162 va_start(args, fmt);
163 do_log(SYSLOG_LEVEL_ERROR, fmt, args);
164 va_end(args);
165 }
166
167 void
sigdie(const char * fmt,...)168 sigdie(const char *fmt,...)
169 {
170 #ifdef DO_LOG_SAFE_IN_SIGHAND
171 va_list args;
172
173 va_start(args, fmt);
174 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
175 va_end(args);
176 #endif
177 _exit(1);
178 }
179
180
181 /* Log this message (information that usually should go to the log). */
182
183 void
logit(const char * fmt,...)184 logit(const char *fmt,...)
185 {
186 va_list args;
187
188 va_start(args, fmt);
189 do_log(SYSLOG_LEVEL_INFO, fmt, args);
190 va_end(args);
191 }
192
193 /* More detailed messages (information that does not need to go to the log). */
194
195 void
verbose(const char * fmt,...)196 verbose(const char *fmt,...)
197 {
198 va_list args;
199
200 va_start(args, fmt);
201 do_log(SYSLOG_LEVEL_VERBOSE, fmt, args);
202 va_end(args);
203 }
204
205 /* Debugging messages that should not be logged during normal operation. */
206
207 void
debug(const char * fmt,...)208 debug(const char *fmt,...)
209 {
210 va_list args;
211
212 va_start(args, fmt);
213 do_log(SYSLOG_LEVEL_DEBUG1, fmt, args);
214 va_end(args);
215 }
216
217 void
debug2(const char * fmt,...)218 debug2(const char *fmt,...)
219 {
220 va_list args;
221
222 va_start(args, fmt);
223 do_log(SYSLOG_LEVEL_DEBUG2, fmt, args);
224 va_end(args);
225 }
226
227 void
debug3(const char * fmt,...)228 debug3(const char *fmt,...)
229 {
230 va_list args;
231
232 va_start(args, fmt);
233 do_log(SYSLOG_LEVEL_DEBUG3, fmt, args);
234 va_end(args);
235 }
236
237 /*
238 * Initialize the log.
239 */
240
241 void
log_init(char * av0,LogLevel level,SyslogFacility facility,int on_stderr)242 log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr)
243 {
244 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
245 struct syslog_data sdata = SYSLOG_DATA_INIT;
246 #endif
247
248 argv0 = av0;
249
250 switch (level) {
251 case SYSLOG_LEVEL_QUIET:
252 case SYSLOG_LEVEL_FATAL:
253 case SYSLOG_LEVEL_ERROR:
254 case SYSLOG_LEVEL_INFO:
255 case SYSLOG_LEVEL_VERBOSE:
256 case SYSLOG_LEVEL_DEBUG1:
257 case SYSLOG_LEVEL_DEBUG2:
258 case SYSLOG_LEVEL_DEBUG3:
259 log_level = level;
260 break;
261 default:
262 fprintf(stderr, "Unrecognized internal syslog level code %d\n",
263 (int) level);
264 exit(1);
265 }
266
267 log_handler = NULL;
268 log_handler_ctx = NULL;
269
270 log_on_stderr = on_stderr;
271 if (on_stderr)
272 return;
273
274 switch (facility) {
275 case SYSLOG_FACILITY_DAEMON:
276 log_facility = LOG_DAEMON;
277 break;
278 case SYSLOG_FACILITY_USER:
279 log_facility = LOG_USER;
280 break;
281 case SYSLOG_FACILITY_AUTH:
282 log_facility = LOG_AUTH;
283 break;
284 #ifdef LOG_AUTHPRIV
285 case SYSLOG_FACILITY_AUTHPRIV:
286 log_facility = LOG_AUTHPRIV;
287 break;
288 #endif
289 case SYSLOG_FACILITY_LOCAL0:
290 log_facility = LOG_LOCAL0;
291 break;
292 case SYSLOG_FACILITY_LOCAL1:
293 log_facility = LOG_LOCAL1;
294 break;
295 case SYSLOG_FACILITY_LOCAL2:
296 log_facility = LOG_LOCAL2;
297 break;
298 case SYSLOG_FACILITY_LOCAL3:
299 log_facility = LOG_LOCAL3;
300 break;
301 case SYSLOG_FACILITY_LOCAL4:
302 log_facility = LOG_LOCAL4;
303 break;
304 case SYSLOG_FACILITY_LOCAL5:
305 log_facility = LOG_LOCAL5;
306 break;
307 case SYSLOG_FACILITY_LOCAL6:
308 log_facility = LOG_LOCAL6;
309 break;
310 case SYSLOG_FACILITY_LOCAL7:
311 log_facility = LOG_LOCAL7;
312 break;
313 default:
314 fprintf(stderr,
315 "Unrecognized internal syslog facility code %d\n",
316 (int) facility);
317 exit(1);
318 }
319
320 /*
321 * If an external library (eg libwrap) attempts to use syslog
322 * immediately after reexec, syslog may be pointing to the wrong
323 * facility, so we force an open/close of syslog here.
324 */
325 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
326 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
327 closelog_r(&sdata);
328 #else
329 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
330 closelog();
331 #endif
332 }
333
334 void
log_change_level(LogLevel new_log_level)335 log_change_level(LogLevel new_log_level)
336 {
337 /* no-op if log_init has not been called */
338 if (argv0 == NULL)
339 return;
340 log_init(argv0, new_log_level, log_facility, log_on_stderr);
341 }
342
343 int
log_is_on_stderr(void)344 log_is_on_stderr(void)
345 {
346 return log_on_stderr;
347 }
348
349 /* redirect what would usually get written to stderr to specified file */
350 void
log_redirect_stderr_to(const char * logfile)351 log_redirect_stderr_to(const char *logfile)
352 {
353 int fd;
354
355 if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
356 fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
357 strerror(errno));
358 exit(1);
359 }
360 log_stderr_fd = fd;
361 }
362
363 #define MSGBUFSIZ 1024
364
365 void
set_log_handler(log_handler_fn * handler,void * ctx)366 set_log_handler(log_handler_fn *handler, void *ctx)
367 {
368 log_handler = handler;
369 log_handler_ctx = ctx;
370 }
371
372 void
do_log2(LogLevel level,const char * fmt,...)373 do_log2(LogLevel level, const char *fmt,...)
374 {
375 va_list args;
376
377 va_start(args, fmt);
378 do_log(level, fmt, args);
379 va_end(args);
380 }
381
382 void
do_log(LogLevel level,const char * fmt,va_list args)383 do_log(LogLevel level, const char *fmt, va_list args)
384 {
385 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
386 struct syslog_data sdata = SYSLOG_DATA_INIT;
387 #endif
388 char msgbuf[MSGBUFSIZ];
389 char fmtbuf[MSGBUFSIZ];
390 char *txt = NULL;
391 int pri = LOG_INFO;
392 int saved_errno = errno;
393 log_handler_fn *tmp_handler;
394
395 if (level > log_level)
396 return;
397
398 switch (level) {
399 case SYSLOG_LEVEL_FATAL:
400 if (!log_on_stderr)
401 txt = "fatal";
402 pri = LOG_CRIT;
403 break;
404 case SYSLOG_LEVEL_ERROR:
405 if (!log_on_stderr)
406 txt = "error";
407 pri = LOG_ERR;
408 break;
409 case SYSLOG_LEVEL_INFO:
410 pri = LOG_INFO;
411 break;
412 case SYSLOG_LEVEL_VERBOSE:
413 pri = LOG_INFO;
414 break;
415 case SYSLOG_LEVEL_DEBUG1:
416 txt = "debug1";
417 pri = LOG_DEBUG;
418 break;
419 case SYSLOG_LEVEL_DEBUG2:
420 txt = "debug2";
421 pri = LOG_DEBUG;
422 break;
423 case SYSLOG_LEVEL_DEBUG3:
424 txt = "debug3";
425 pri = LOG_DEBUG;
426 break;
427 default:
428 txt = "internal error";
429 pri = LOG_ERR;
430 break;
431 }
432 if (txt != NULL && log_handler == NULL) {
433 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
434 vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
435 } else {
436 vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
437 }
438 strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
439 log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
440 if (log_handler != NULL) {
441 /* Avoid recursion */
442 tmp_handler = log_handler;
443 log_handler = NULL;
444 tmp_handler(level, fmtbuf, log_handler_ctx);
445 log_handler = tmp_handler;
446 } else if (log_on_stderr) {
447 snprintf(msgbuf, sizeof msgbuf, "%s\r\n", fmtbuf);
448 (void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
449 } else {
450 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
451 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
452 syslog_r(pri, &sdata, "%.500s", fmtbuf);
453 closelog_r(&sdata);
454 #else
455 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
456 syslog(pri, "%.500s", fmtbuf);
457 closelog();
458 #endif
459 }
460 errno = saved_errno;
461 }
462