1 /* $OpenBSD: log.c,v 1.49 2017/03/10 03:15:58 djm 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 "log.h"
54
55 static LogLevel log_level = SYSLOG_LEVEL_INFO;
56 static int log_on_stderr = 1;
57 static int log_stderr_fd = STDERR_FILENO;
58 static int log_facility = LOG_AUTH;
59 static char *argv0;
60 static log_handler_fn *log_handler;
61 static void *log_handler_ctx;
62
63 extern char *__progname;
64
65 #define LOG_SYSLOG_VIS (VIS_CSTYLE|VIS_NL|VIS_TAB|VIS_OCTAL)
66 #define LOG_STDERR_VIS (VIS_SAFE|VIS_OCTAL)
67
68 /* textual representation of log-facilities/levels */
69
70 static struct {
71 const char *name;
72 SyslogFacility val;
73 } log_facilities[] = {
74 { "DAEMON", SYSLOG_FACILITY_DAEMON },
75 { "USER", SYSLOG_FACILITY_USER },
76 { "AUTH", SYSLOG_FACILITY_AUTH },
77 #ifdef LOG_AUTHPRIV
78 { "AUTHPRIV", SYSLOG_FACILITY_AUTHPRIV },
79 #endif
80 { "LOCAL0", SYSLOG_FACILITY_LOCAL0 },
81 { "LOCAL1", SYSLOG_FACILITY_LOCAL1 },
82 { "LOCAL2", SYSLOG_FACILITY_LOCAL2 },
83 { "LOCAL3", SYSLOG_FACILITY_LOCAL3 },
84 { "LOCAL4", SYSLOG_FACILITY_LOCAL4 },
85 { "LOCAL5", SYSLOG_FACILITY_LOCAL5 },
86 { "LOCAL6", SYSLOG_FACILITY_LOCAL6 },
87 { "LOCAL7", SYSLOG_FACILITY_LOCAL7 },
88 { NULL, SYSLOG_FACILITY_NOT_SET }
89 };
90
91 static struct {
92 const char *name;
93 LogLevel val;
94 } log_levels[] =
95 {
96 { "QUIET", SYSLOG_LEVEL_QUIET },
97 { "FATAL", SYSLOG_LEVEL_FATAL },
98 { "ERROR", SYSLOG_LEVEL_ERROR },
99 { "INFO", SYSLOG_LEVEL_INFO },
100 { "VERBOSE", SYSLOG_LEVEL_VERBOSE },
101 { "DEBUG", SYSLOG_LEVEL_DEBUG1 },
102 { "DEBUG1", SYSLOG_LEVEL_DEBUG1 },
103 { "DEBUG2", SYSLOG_LEVEL_DEBUG2 },
104 { "DEBUG3", SYSLOG_LEVEL_DEBUG3 },
105 { NULL, SYSLOG_LEVEL_NOT_SET }
106 };
107
108 SyslogFacility
log_facility_number(char * name)109 log_facility_number(char *name)
110 {
111 int i;
112
113 if (name != NULL)
114 for (i = 0; log_facilities[i].name; i++)
115 if (strcasecmp(log_facilities[i].name, name) == 0)
116 return log_facilities[i].val;
117 return SYSLOG_FACILITY_NOT_SET;
118 }
119
120 const char *
log_facility_name(SyslogFacility facility)121 log_facility_name(SyslogFacility facility)
122 {
123 u_int i;
124
125 for (i = 0; log_facilities[i].name; i++)
126 if (log_facilities[i].val == facility)
127 return log_facilities[i].name;
128 return NULL;
129 }
130
131 LogLevel
log_level_number(char * name)132 log_level_number(char *name)
133 {
134 int i;
135
136 if (name != NULL)
137 for (i = 0; log_levels[i].name; i++)
138 if (strcasecmp(log_levels[i].name, name) == 0)
139 return log_levels[i].val;
140 return SYSLOG_LEVEL_NOT_SET;
141 }
142
143 const char *
log_level_name(LogLevel level)144 log_level_name(LogLevel level)
145 {
146 u_int i;
147
148 for (i = 0; log_levels[i].name != NULL; i++)
149 if (log_levels[i].val == level)
150 return log_levels[i].name;
151 return NULL;
152 }
153
154 /* Error messages that should be logged. */
155
156 void
error(const char * fmt,...)157 error(const char *fmt,...)
158 {
159 va_list args;
160
161 va_start(args, fmt);
162 do_log(SYSLOG_LEVEL_ERROR, fmt, args);
163 va_end(args);
164 }
165
166 void
sigdie(const char * fmt,...)167 sigdie(const char *fmt,...)
168 {
169 #ifdef DO_LOG_SAFE_IN_SIGHAND
170 va_list args;
171
172 va_start(args, fmt);
173 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
174 va_end(args);
175 #endif
176 _exit(1);
177 }
178
179 void
logdie(const char * fmt,...)180 logdie(const char *fmt,...)
181 {
182 va_list args;
183
184 va_start(args, fmt);
185 do_log(SYSLOG_LEVEL_INFO, fmt, args);
186 va_end(args);
187 cleanup_exit(255);
188 }
189
190 /* Log this message (information that usually should go to the log). */
191
192 void
logit(const char * fmt,...)193 logit(const char *fmt,...)
194 {
195 va_list args;
196
197 va_start(args, fmt);
198 do_log(SYSLOG_LEVEL_INFO, fmt, args);
199 va_end(args);
200 }
201
202 /* More detailed messages (information that does not need to go to the log). */
203
204 void
verbose(const char * fmt,...)205 verbose(const char *fmt,...)
206 {
207 va_list args;
208
209 va_start(args, fmt);
210 do_log(SYSLOG_LEVEL_VERBOSE, fmt, args);
211 va_end(args);
212 }
213
214 /* Debugging messages that should not be logged during normal operation. */
215
216 void
debug(const char * fmt,...)217 debug(const char *fmt,...)
218 {
219 va_list args;
220
221 va_start(args, fmt);
222 do_log(SYSLOG_LEVEL_DEBUG1, fmt, args);
223 va_end(args);
224 }
225
226 void
debug2(const char * fmt,...)227 debug2(const char *fmt,...)
228 {
229 va_list args;
230
231 va_start(args, fmt);
232 do_log(SYSLOG_LEVEL_DEBUG2, fmt, args);
233 va_end(args);
234 }
235
236 void
debug3(const char * fmt,...)237 debug3(const char *fmt,...)
238 {
239 va_list args;
240
241 va_start(args, fmt);
242 do_log(SYSLOG_LEVEL_DEBUG3, fmt, args);
243 va_end(args);
244 }
245
246 /*
247 * Initialize the log.
248 */
249
250 void
log_init(char * av0,LogLevel level,SyslogFacility facility,int on_stderr)251 log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr)
252 {
253 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
254 struct syslog_data sdata = SYSLOG_DATA_INIT;
255 #endif
256
257 argv0 = av0;
258
259 switch (level) {
260 case SYSLOG_LEVEL_QUIET:
261 case SYSLOG_LEVEL_FATAL:
262 case SYSLOG_LEVEL_ERROR:
263 case SYSLOG_LEVEL_INFO:
264 case SYSLOG_LEVEL_VERBOSE:
265 case SYSLOG_LEVEL_DEBUG1:
266 case SYSLOG_LEVEL_DEBUG2:
267 case SYSLOG_LEVEL_DEBUG3:
268 log_level = level;
269 break;
270 default:
271 fprintf(stderr, "Unrecognized internal syslog level code %d\n",
272 (int) level);
273 exit(1);
274 }
275
276 log_handler = NULL;
277 log_handler_ctx = NULL;
278
279 log_on_stderr = on_stderr;
280 if (on_stderr)
281 return;
282
283 switch (facility) {
284 case SYSLOG_FACILITY_DAEMON:
285 log_facility = LOG_DAEMON;
286 break;
287 case SYSLOG_FACILITY_USER:
288 log_facility = LOG_USER;
289 break;
290 case SYSLOG_FACILITY_AUTH:
291 log_facility = LOG_AUTH;
292 break;
293 #ifdef LOG_AUTHPRIV
294 case SYSLOG_FACILITY_AUTHPRIV:
295 log_facility = LOG_AUTHPRIV;
296 break;
297 #endif
298 case SYSLOG_FACILITY_LOCAL0:
299 log_facility = LOG_LOCAL0;
300 break;
301 case SYSLOG_FACILITY_LOCAL1:
302 log_facility = LOG_LOCAL1;
303 break;
304 case SYSLOG_FACILITY_LOCAL2:
305 log_facility = LOG_LOCAL2;
306 break;
307 case SYSLOG_FACILITY_LOCAL3:
308 log_facility = LOG_LOCAL3;
309 break;
310 case SYSLOG_FACILITY_LOCAL4:
311 log_facility = LOG_LOCAL4;
312 break;
313 case SYSLOG_FACILITY_LOCAL5:
314 log_facility = LOG_LOCAL5;
315 break;
316 case SYSLOG_FACILITY_LOCAL6:
317 log_facility = LOG_LOCAL6;
318 break;
319 case SYSLOG_FACILITY_LOCAL7:
320 log_facility = LOG_LOCAL7;
321 break;
322 default:
323 fprintf(stderr,
324 "Unrecognized internal syslog facility code %d\n",
325 (int) facility);
326 exit(1);
327 }
328
329 /*
330 * If an external library (eg libwrap) attempts to use syslog
331 * immediately after reexec, syslog may be pointing to the wrong
332 * facility, so we force an open/close of syslog here.
333 */
334 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
335 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
336 closelog_r(&sdata);
337 #else
338 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
339 closelog();
340 #endif
341 }
342
343 void
log_change_level(LogLevel new_log_level)344 log_change_level(LogLevel new_log_level)
345 {
346 /* no-op if log_init has not been called */
347 if (argv0 == NULL)
348 return;
349 log_init(argv0, new_log_level, log_facility, log_on_stderr);
350 }
351
352 int
log_is_on_stderr(void)353 log_is_on_stderr(void)
354 {
355 return log_on_stderr && log_stderr_fd == STDERR_FILENO;
356 }
357
358 /* redirect what would usually get written to stderr to specified file */
359 void
log_redirect_stderr_to(const char * logfile)360 log_redirect_stderr_to(const char *logfile)
361 {
362 int fd;
363
364 if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
365 fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
366 strerror(errno));
367 exit(1);
368 }
369 log_stderr_fd = fd;
370 }
371
372 #define MSGBUFSIZ 1024
373
374 void
set_log_handler(log_handler_fn * handler,void * ctx)375 set_log_handler(log_handler_fn *handler, void *ctx)
376 {
377 log_handler = handler;
378 log_handler_ctx = ctx;
379 }
380
381 void
do_log2(LogLevel level,const char * fmt,...)382 do_log2(LogLevel level, const char *fmt,...)
383 {
384 va_list args;
385
386 va_start(args, fmt);
387 do_log(level, fmt, args);
388 va_end(args);
389 }
390
391 void
do_log(LogLevel level,const char * fmt,va_list args)392 do_log(LogLevel level, const char *fmt, va_list args)
393 {
394 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
395 struct syslog_data sdata = SYSLOG_DATA_INIT;
396 #endif
397 char msgbuf[MSGBUFSIZ];
398 char fmtbuf[MSGBUFSIZ];
399 char *txt = NULL;
400 int pri = LOG_INFO;
401 int saved_errno = errno;
402 log_handler_fn *tmp_handler;
403
404 if (level > log_level)
405 return;
406
407 switch (level) {
408 case SYSLOG_LEVEL_FATAL:
409 if (!log_on_stderr)
410 txt = "fatal";
411 pri = LOG_CRIT;
412 break;
413 case SYSLOG_LEVEL_ERROR:
414 if (!log_on_stderr)
415 txt = "error";
416 pri = LOG_ERR;
417 break;
418 case SYSLOG_LEVEL_INFO:
419 pri = LOG_INFO;
420 break;
421 case SYSLOG_LEVEL_VERBOSE:
422 pri = LOG_INFO;
423 break;
424 case SYSLOG_LEVEL_DEBUG1:
425 txt = "debug1";
426 pri = LOG_DEBUG;
427 break;
428 case SYSLOG_LEVEL_DEBUG2:
429 txt = "debug2";
430 pri = LOG_DEBUG;
431 break;
432 case SYSLOG_LEVEL_DEBUG3:
433 txt = "debug3";
434 pri = LOG_DEBUG;
435 break;
436 default:
437 txt = "internal error";
438 pri = LOG_ERR;
439 break;
440 }
441 if (txt != NULL && log_handler == NULL) {
442 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
443 vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
444 } else {
445 vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
446 }
447 strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
448 log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
449 if (log_handler != NULL) {
450 /* Avoid recursion */
451 tmp_handler = log_handler;
452 log_handler = NULL;
453 tmp_handler(level, fmtbuf, log_handler_ctx);
454 log_handler = tmp_handler;
455 } else if (log_on_stderr) {
456 snprintf(msgbuf, sizeof msgbuf, "%.*s\r\n",
457 (int)sizeof msgbuf - 3, fmtbuf);
458 (void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
459 } else {
460 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
461 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
462 syslog_r(pri, &sdata, "%.500s", fmtbuf);
463 closelog_r(&sdata);
464 #else
465 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
466 syslog(pri, "%.500s", fmtbuf);
467 closelog();
468 #endif
469 }
470 errno = saved_errno;
471 }
472