1 /* $OpenBSD: log.c,v 1.51 2018/07/27 12:03:17 markus 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 LogLevel
log_level_get(void)109 log_level_get(void)
110 {
111 return log_level;
112 }
113
114 SyslogFacility
log_facility_number(char * name)115 log_facility_number(char *name)
116 {
117 int i;
118
119 if (name != NULL)
120 for (i = 0; log_facilities[i].name; i++)
121 if (strcasecmp(log_facilities[i].name, name) == 0)
122 return log_facilities[i].val;
123 return SYSLOG_FACILITY_NOT_SET;
124 }
125
126 const char *
log_facility_name(SyslogFacility facility)127 log_facility_name(SyslogFacility facility)
128 {
129 u_int i;
130
131 for (i = 0; log_facilities[i].name; i++)
132 if (log_facilities[i].val == facility)
133 return log_facilities[i].name;
134 return NULL;
135 }
136
137 LogLevel
log_level_number(char * name)138 log_level_number(char *name)
139 {
140 int i;
141
142 if (name != NULL)
143 for (i = 0; log_levels[i].name; i++)
144 if (strcasecmp(log_levels[i].name, name) == 0)
145 return log_levels[i].val;
146 return SYSLOG_LEVEL_NOT_SET;
147 }
148
149 const char *
log_level_name(LogLevel level)150 log_level_name(LogLevel level)
151 {
152 u_int i;
153
154 for (i = 0; log_levels[i].name != NULL; i++)
155 if (log_levels[i].val == level)
156 return log_levels[i].name;
157 return NULL;
158 }
159
160 /* Error messages that should be logged. */
161
162 void
error(const char * fmt,...)163 error(const char *fmt,...)
164 {
165 va_list args;
166
167 va_start(args, fmt);
168 do_log(SYSLOG_LEVEL_ERROR, fmt, args);
169 va_end(args);
170 }
171
172 void
sigdie(const char * fmt,...)173 sigdie(const char *fmt,...)
174 {
175 #ifdef DO_LOG_SAFE_IN_SIGHAND
176 va_list args;
177
178 va_start(args, fmt);
179 do_log(SYSLOG_LEVEL_FATAL, fmt, args);
180 va_end(args);
181 #endif
182 _exit(1);
183 }
184
185 void
logdie(const char * fmt,...)186 logdie(const char *fmt,...)
187 {
188 va_list args;
189
190 va_start(args, fmt);
191 do_log(SYSLOG_LEVEL_INFO, fmt, args);
192 va_end(args);
193 cleanup_exit(255);
194 }
195
196 /* Log this message (information that usually should go to the log). */
197
198 void
logit(const char * fmt,...)199 logit(const char *fmt,...)
200 {
201 va_list args;
202
203 va_start(args, fmt);
204 do_log(SYSLOG_LEVEL_INFO, fmt, args);
205 va_end(args);
206 }
207
208 /* More detailed messages (information that does not need to go to the log). */
209
210 void
verbose(const char * fmt,...)211 verbose(const char *fmt,...)
212 {
213 va_list args;
214
215 va_start(args, fmt);
216 do_log(SYSLOG_LEVEL_VERBOSE, fmt, args);
217 va_end(args);
218 }
219
220 /* Debugging messages that should not be logged during normal operation. */
221
222 void
debug(const char * fmt,...)223 debug(const char *fmt,...)
224 {
225 va_list args;
226
227 va_start(args, fmt);
228 do_log(SYSLOG_LEVEL_DEBUG1, fmt, args);
229 va_end(args);
230 }
231
232 void
debug2(const char * fmt,...)233 debug2(const char *fmt,...)
234 {
235 va_list args;
236
237 va_start(args, fmt);
238 do_log(SYSLOG_LEVEL_DEBUG2, fmt, args);
239 va_end(args);
240 }
241
242 void
debug3(const char * fmt,...)243 debug3(const char *fmt,...)
244 {
245 va_list args;
246
247 va_start(args, fmt);
248 do_log(SYSLOG_LEVEL_DEBUG3, fmt, args);
249 va_end(args);
250 }
251
252 /*
253 * Initialize the log.
254 */
255
256 void
log_init(char * av0,LogLevel level,SyslogFacility facility,int on_stderr)257 log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr)
258 {
259 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
260 struct syslog_data sdata = SYSLOG_DATA_INIT;
261 #endif
262
263 argv0 = av0;
264
265 if (log_change_level(level) != 0) {
266 fprintf(stderr, "Unrecognized internal syslog level code %d\n",
267 (int) level);
268 exit(1);
269 }
270
271 log_handler = NULL;
272 log_handler_ctx = NULL;
273
274 log_on_stderr = on_stderr;
275 if (on_stderr)
276 return;
277
278 switch (facility) {
279 case SYSLOG_FACILITY_DAEMON:
280 log_facility = LOG_DAEMON;
281 break;
282 case SYSLOG_FACILITY_USER:
283 log_facility = LOG_USER;
284 break;
285 case SYSLOG_FACILITY_AUTH:
286 log_facility = LOG_AUTH;
287 break;
288 #ifdef LOG_AUTHPRIV
289 case SYSLOG_FACILITY_AUTHPRIV:
290 log_facility = LOG_AUTHPRIV;
291 break;
292 #endif
293 case SYSLOG_FACILITY_LOCAL0:
294 log_facility = LOG_LOCAL0;
295 break;
296 case SYSLOG_FACILITY_LOCAL1:
297 log_facility = LOG_LOCAL1;
298 break;
299 case SYSLOG_FACILITY_LOCAL2:
300 log_facility = LOG_LOCAL2;
301 break;
302 case SYSLOG_FACILITY_LOCAL3:
303 log_facility = LOG_LOCAL3;
304 break;
305 case SYSLOG_FACILITY_LOCAL4:
306 log_facility = LOG_LOCAL4;
307 break;
308 case SYSLOG_FACILITY_LOCAL5:
309 log_facility = LOG_LOCAL5;
310 break;
311 case SYSLOG_FACILITY_LOCAL6:
312 log_facility = LOG_LOCAL6;
313 break;
314 case SYSLOG_FACILITY_LOCAL7:
315 log_facility = LOG_LOCAL7;
316 break;
317 default:
318 fprintf(stderr,
319 "Unrecognized internal syslog facility code %d\n",
320 (int) facility);
321 exit(1);
322 }
323
324 /*
325 * If an external library (eg libwrap) attempts to use syslog
326 * immediately after reexec, syslog may be pointing to the wrong
327 * facility, so we force an open/close of syslog here.
328 */
329 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
330 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
331 closelog_r(&sdata);
332 #else
333 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
334 closelog();
335 #endif
336 }
337
338 int
log_change_level(LogLevel new_log_level)339 log_change_level(LogLevel new_log_level)
340 {
341 /* no-op if log_init has not been called */
342 if (argv0 == NULL)
343 return 0;
344
345 switch (new_log_level) {
346 case SYSLOG_LEVEL_QUIET:
347 case SYSLOG_LEVEL_FATAL:
348 case SYSLOG_LEVEL_ERROR:
349 case SYSLOG_LEVEL_INFO:
350 case SYSLOG_LEVEL_VERBOSE:
351 case SYSLOG_LEVEL_DEBUG1:
352 case SYSLOG_LEVEL_DEBUG2:
353 case SYSLOG_LEVEL_DEBUG3:
354 log_level = new_log_level;
355 return 0;
356 default:
357 return -1;
358 }
359 }
360
361 int
log_is_on_stderr(void)362 log_is_on_stderr(void)
363 {
364 return log_on_stderr && log_stderr_fd == STDERR_FILENO;
365 }
366
367 /* redirect what would usually get written to stderr to specified file */
368 void
log_redirect_stderr_to(const char * logfile)369 log_redirect_stderr_to(const char *logfile)
370 {
371 int fd;
372
373 if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
374 fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
375 strerror(errno));
376 exit(1);
377 }
378 log_stderr_fd = fd;
379 }
380
381 #define MSGBUFSIZ 1024
382
383 void
set_log_handler(log_handler_fn * handler,void * ctx)384 set_log_handler(log_handler_fn *handler, void *ctx)
385 {
386 log_handler = handler;
387 log_handler_ctx = ctx;
388 }
389
390 void
do_log2(LogLevel level,const char * fmt,...)391 do_log2(LogLevel level, const char *fmt,...)
392 {
393 va_list args;
394
395 va_start(args, fmt);
396 do_log(level, fmt, args);
397 va_end(args);
398 }
399
400 void
do_log(LogLevel level,const char * fmt,va_list args)401 do_log(LogLevel level, const char *fmt, va_list args)
402 {
403 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
404 struct syslog_data sdata = SYSLOG_DATA_INIT;
405 #endif
406 char msgbuf[MSGBUFSIZ];
407 char fmtbuf[MSGBUFSIZ];
408 char *txt = NULL;
409 int pri = LOG_INFO;
410 int saved_errno = errno;
411 log_handler_fn *tmp_handler;
412
413 if (level > log_level)
414 return;
415
416 switch (level) {
417 case SYSLOG_LEVEL_FATAL:
418 if (!log_on_stderr)
419 txt = "fatal";
420 pri = LOG_CRIT;
421 break;
422 case SYSLOG_LEVEL_ERROR:
423 if (!log_on_stderr)
424 txt = "error";
425 pri = LOG_ERR;
426 break;
427 case SYSLOG_LEVEL_INFO:
428 pri = LOG_INFO;
429 break;
430 case SYSLOG_LEVEL_VERBOSE:
431 pri = LOG_INFO;
432 break;
433 case SYSLOG_LEVEL_DEBUG1:
434 txt = "debug1";
435 pri = LOG_DEBUG;
436 break;
437 case SYSLOG_LEVEL_DEBUG2:
438 txt = "debug2";
439 pri = LOG_DEBUG;
440 break;
441 case SYSLOG_LEVEL_DEBUG3:
442 txt = "debug3";
443 pri = LOG_DEBUG;
444 break;
445 default:
446 txt = "internal error";
447 pri = LOG_ERR;
448 break;
449 }
450 if (txt != NULL && log_handler == NULL) {
451 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
452 vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
453 } else {
454 vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
455 }
456 strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
457 log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
458 if (log_handler != NULL) {
459 /* Avoid recursion */
460 tmp_handler = log_handler;
461 log_handler = NULL;
462 tmp_handler(level, fmtbuf, log_handler_ctx);
463 log_handler = tmp_handler;
464 } else if (log_on_stderr) {
465 snprintf(msgbuf, sizeof msgbuf, "%.*s\r\n",
466 (int)sizeof msgbuf - 3, fmtbuf);
467 (void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
468 } else {
469 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
470 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
471 syslog_r(pri, &sdata, "%.500s", fmtbuf);
472 closelog_r(&sdata);
473 #else
474 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
475 syslog(pri, "%.500s", fmtbuf);
476 closelog();
477 #endif
478 }
479 errno = saved_errno;
480 }
481