1 /* $OpenBSD: log.c,v 1.62 2024/06/27 22:36:44 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 #include "match.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 const char *argv0;
61 static log_handler_fn *log_handler;
62 static void *log_handler_ctx;
63 static char **log_verbose;
64 static size_t nlog_verbose;
65
66 extern char *__progname;
67
68 #define LOG_SYSLOG_VIS (VIS_CSTYLE|VIS_NL|VIS_TAB|VIS_OCTAL)
69 #define LOG_STDERR_VIS (VIS_SAFE|VIS_OCTAL)
70
71 /* textual representation of log-facilities/levels */
72
73 static struct {
74 const char *name;
75 SyslogFacility val;
76 } log_facilities[] = {
77 { "DAEMON", SYSLOG_FACILITY_DAEMON },
78 { "USER", SYSLOG_FACILITY_USER },
79 { "AUTH", SYSLOG_FACILITY_AUTH },
80 #ifdef LOG_AUTHPRIV
81 { "AUTHPRIV", SYSLOG_FACILITY_AUTHPRIV },
82 #endif
83 { "LOCAL0", SYSLOG_FACILITY_LOCAL0 },
84 { "LOCAL1", SYSLOG_FACILITY_LOCAL1 },
85 { "LOCAL2", SYSLOG_FACILITY_LOCAL2 },
86 { "LOCAL3", SYSLOG_FACILITY_LOCAL3 },
87 { "LOCAL4", SYSLOG_FACILITY_LOCAL4 },
88 { "LOCAL5", SYSLOG_FACILITY_LOCAL5 },
89 { "LOCAL6", SYSLOG_FACILITY_LOCAL6 },
90 { "LOCAL7", SYSLOG_FACILITY_LOCAL7 },
91 { NULL, SYSLOG_FACILITY_NOT_SET }
92 };
93
94 static struct {
95 const char *name;
96 LogLevel val;
97 } log_levels[] =
98 {
99 { "QUIET", SYSLOG_LEVEL_QUIET },
100 { "FATAL", SYSLOG_LEVEL_FATAL },
101 { "ERROR", SYSLOG_LEVEL_ERROR },
102 { "INFO", SYSLOG_LEVEL_INFO },
103 { "VERBOSE", SYSLOG_LEVEL_VERBOSE },
104 { "DEBUG", SYSLOG_LEVEL_DEBUG1 },
105 { "DEBUG1", SYSLOG_LEVEL_DEBUG1 },
106 { "DEBUG2", SYSLOG_LEVEL_DEBUG2 },
107 { "DEBUG3", SYSLOG_LEVEL_DEBUG3 },
108 { NULL, SYSLOG_LEVEL_NOT_SET }
109 };
110
111 LogLevel
log_level_get(void)112 log_level_get(void)
113 {
114 return log_level;
115 }
116
117 SyslogFacility
log_facility_number(char * name)118 log_facility_number(char *name)
119 {
120 int i;
121
122 if (name != NULL)
123 for (i = 0; log_facilities[i].name; i++)
124 if (strcasecmp(log_facilities[i].name, name) == 0)
125 return log_facilities[i].val;
126 return SYSLOG_FACILITY_NOT_SET;
127 }
128
129 const char *
log_facility_name(SyslogFacility facility)130 log_facility_name(SyslogFacility facility)
131 {
132 u_int i;
133
134 for (i = 0; log_facilities[i].name; i++)
135 if (log_facilities[i].val == facility)
136 return log_facilities[i].name;
137 return NULL;
138 }
139
140 LogLevel
log_level_number(char * name)141 log_level_number(char *name)
142 {
143 int i;
144
145 if (name != NULL)
146 for (i = 0; log_levels[i].name; i++)
147 if (strcasecmp(log_levels[i].name, name) == 0)
148 return log_levels[i].val;
149 return SYSLOG_LEVEL_NOT_SET;
150 }
151
152 const char *
log_level_name(LogLevel level)153 log_level_name(LogLevel level)
154 {
155 u_int i;
156
157 for (i = 0; log_levels[i].name != NULL; i++)
158 if (log_levels[i].val == level)
159 return log_levels[i].name;
160 return NULL;
161 }
162
163 void
log_verbose_add(const char * s)164 log_verbose_add(const char *s)
165 {
166 char **tmp;
167
168 /* Ignore failures here */
169 if ((tmp = recallocarray(log_verbose, nlog_verbose, nlog_verbose + 1,
170 sizeof(*log_verbose))) != NULL) {
171 log_verbose = tmp;
172 if ((log_verbose[nlog_verbose] = strdup(s)) != NULL)
173 nlog_verbose++;
174 }
175 }
176
177 void
log_verbose_reset(void)178 log_verbose_reset(void)
179 {
180 size_t i;
181
182 for (i = 0; i < nlog_verbose; i++)
183 free(log_verbose[i]);
184 free(log_verbose);
185 log_verbose = NULL;
186 nlog_verbose = 0;
187 }
188
189 /*
190 * Initialize the log.
191 */
192
193 void
log_init(const char * av0,LogLevel level,SyslogFacility facility,int on_stderr)194 log_init(const char *av0, LogLevel level, SyslogFacility facility,
195 int on_stderr)
196 {
197 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
198 struct syslog_data sdata = SYSLOG_DATA_INIT;
199 #endif
200
201 argv0 = av0;
202
203 if (log_change_level(level) != 0) {
204 fprintf(stderr, "Unrecognized internal syslog level code %d\n",
205 (int) level);
206 exit(1);
207 }
208
209 log_handler = NULL;
210 log_handler_ctx = NULL;
211
212 log_on_stderr = on_stderr;
213 if (on_stderr)
214 return;
215
216 switch (facility) {
217 case SYSLOG_FACILITY_DAEMON:
218 log_facility = LOG_DAEMON;
219 break;
220 case SYSLOG_FACILITY_USER:
221 log_facility = LOG_USER;
222 break;
223 case SYSLOG_FACILITY_AUTH:
224 log_facility = LOG_AUTH;
225 break;
226 #ifdef LOG_AUTHPRIV
227 case SYSLOG_FACILITY_AUTHPRIV:
228 log_facility = LOG_AUTHPRIV;
229 break;
230 #endif
231 case SYSLOG_FACILITY_LOCAL0:
232 log_facility = LOG_LOCAL0;
233 break;
234 case SYSLOG_FACILITY_LOCAL1:
235 log_facility = LOG_LOCAL1;
236 break;
237 case SYSLOG_FACILITY_LOCAL2:
238 log_facility = LOG_LOCAL2;
239 break;
240 case SYSLOG_FACILITY_LOCAL3:
241 log_facility = LOG_LOCAL3;
242 break;
243 case SYSLOG_FACILITY_LOCAL4:
244 log_facility = LOG_LOCAL4;
245 break;
246 case SYSLOG_FACILITY_LOCAL5:
247 log_facility = LOG_LOCAL5;
248 break;
249 case SYSLOG_FACILITY_LOCAL6:
250 log_facility = LOG_LOCAL6;
251 break;
252 case SYSLOG_FACILITY_LOCAL7:
253 log_facility = LOG_LOCAL7;
254 break;
255 default:
256 fprintf(stderr,
257 "Unrecognized internal syslog facility code %d\n",
258 (int) facility);
259 exit(1);
260 }
261
262 /*
263 * If an external library (eg libwrap) attempts to use syslog
264 * immediately after reexec, syslog may be pointing to the wrong
265 * facility, so we force an open/close of syslog here.
266 */
267 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
268 openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
269 closelog_r(&sdata);
270 #else
271 openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
272 closelog();
273 #endif
274 }
275
276 int
log_change_level(LogLevel new_log_level)277 log_change_level(LogLevel new_log_level)
278 {
279 /* no-op if log_init has not been called */
280 if (argv0 == NULL)
281 return 0;
282
283 switch (new_log_level) {
284 case SYSLOG_LEVEL_QUIET:
285 case SYSLOG_LEVEL_FATAL:
286 case SYSLOG_LEVEL_ERROR:
287 case SYSLOG_LEVEL_INFO:
288 case SYSLOG_LEVEL_VERBOSE:
289 case SYSLOG_LEVEL_DEBUG1:
290 case SYSLOG_LEVEL_DEBUG2:
291 case SYSLOG_LEVEL_DEBUG3:
292 log_level = new_log_level;
293 return 0;
294 default:
295 return -1;
296 }
297 }
298
299 int
log_is_on_stderr(void)300 log_is_on_stderr(void)
301 {
302 return log_on_stderr && log_stderr_fd == STDERR_FILENO;
303 }
304
305 /* redirect what would usually get written to stderr to specified file */
306 void
log_redirect_stderr_to(const char * logfile)307 log_redirect_stderr_to(const char *logfile)
308 {
309 int fd;
310
311 if (logfile == NULL) {
312 if (log_stderr_fd != STDERR_FILENO) {
313 close(log_stderr_fd);
314 log_stderr_fd = STDERR_FILENO;
315 }
316 return;
317 }
318
319 if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
320 fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
321 strerror(errno));
322 exit(1);
323 }
324 log_stderr_fd = fd;
325 }
326
327 #define MSGBUFSIZ 1024
328
329 void
set_log_handler(log_handler_fn * handler,void * ctx)330 set_log_handler(log_handler_fn *handler, void *ctx)
331 {
332 log_handler = handler;
333 log_handler_ctx = ctx;
334 }
335
336 static void
do_log(LogLevel level,int force,const char * suffix,const char * fmt,va_list args)337 do_log(LogLevel level, int force, const char *suffix, const char *fmt,
338 va_list args)
339 {
340 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
341 struct syslog_data sdata = SYSLOG_DATA_INIT;
342 #endif
343 char msgbuf[MSGBUFSIZ];
344 char fmtbuf[MSGBUFSIZ];
345 char *txt = NULL;
346 int pri = LOG_INFO;
347 int saved_errno = errno;
348 log_handler_fn *tmp_handler;
349 const char *progname = argv0 != NULL ? argv0 : __progname;
350
351 if (!force && level > log_level)
352 return;
353
354 switch (level) {
355 case SYSLOG_LEVEL_FATAL:
356 if (!log_on_stderr)
357 txt = "fatal";
358 pri = LOG_CRIT;
359 break;
360 case SYSLOG_LEVEL_ERROR:
361 if (!log_on_stderr)
362 txt = "error";
363 pri = LOG_ERR;
364 break;
365 case SYSLOG_LEVEL_INFO:
366 pri = LOG_INFO;
367 break;
368 case SYSLOG_LEVEL_VERBOSE:
369 pri = LOG_INFO;
370 break;
371 case SYSLOG_LEVEL_DEBUG1:
372 txt = "debug1";
373 pri = LOG_DEBUG;
374 break;
375 case SYSLOG_LEVEL_DEBUG2:
376 txt = "debug2";
377 pri = LOG_DEBUG;
378 break;
379 case SYSLOG_LEVEL_DEBUG3:
380 txt = "debug3";
381 pri = LOG_DEBUG;
382 break;
383 default:
384 txt = "internal error";
385 pri = LOG_ERR;
386 break;
387 }
388 if (txt != NULL && log_handler == NULL) {
389 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
390 vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
391 } else {
392 vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
393 }
394 if (suffix != NULL) {
395 snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", msgbuf, suffix);
396 strlcpy(msgbuf, fmtbuf, sizeof(msgbuf));
397 }
398 strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
399 log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
400 if (log_handler != NULL) {
401 /* Avoid recursion */
402 tmp_handler = log_handler;
403 log_handler = NULL;
404 tmp_handler(level, force, fmtbuf, log_handler_ctx);
405 log_handler = tmp_handler;
406 } else if (log_on_stderr) {
407 snprintf(msgbuf, sizeof msgbuf, "%s%s%.*s\r\n",
408 (log_on_stderr > 1) ? progname : "",
409 (log_on_stderr > 1) ? ": " : "",
410 (int)sizeof msgbuf - 3, fmtbuf);
411 (void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
412 } else {
413 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
414 openlog_r(progname, LOG_PID, log_facility, &sdata);
415 syslog_r(pri, &sdata, "%.500s", fmtbuf);
416 closelog_r(&sdata);
417 #else
418 openlog(progname, LOG_PID, log_facility);
419 syslog(pri, "%.500s", fmtbuf);
420 closelog();
421 #endif
422 }
423 errno = saved_errno;
424 }
425
426 void
sshlog(const char * file,const char * func,int line,int showfunc,LogLevel level,const char * suffix,const char * fmt,...)427 sshlog(const char *file, const char *func, int line, int showfunc,
428 LogLevel level, const char *suffix, const char *fmt, ...)
429 {
430 va_list args;
431
432 va_start(args, fmt);
433 sshlogv(file, func, line, showfunc, level, suffix, fmt, args);
434 va_end(args);
435 }
436
437 void
sshlogdie(const char * file,const char * func,int line,int showfunc,LogLevel level,const char * suffix,const char * fmt,...)438 sshlogdie(const char *file, const char *func, int line, int showfunc,
439 LogLevel level, const char *suffix, const char *fmt, ...)
440 {
441 va_list args;
442
443 va_start(args, fmt);
444 sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_INFO,
445 suffix, fmt, args);
446 va_end(args);
447 cleanup_exit(255);
448 }
449
450 void
sshlogv(const char * file,const char * func,int line,int showfunc,LogLevel level,const char * suffix,const char * fmt,va_list args)451 sshlogv(const char *file, const char *func, int line, int showfunc,
452 LogLevel level, const char *suffix, const char *fmt, va_list args)
453 {
454 char tag[128], fmt2[MSGBUFSIZ + 128];
455 int forced = 0;
456 const char *cp;
457 size_t i;
458
459 /* short circuit processing early if we're not going to log anything */
460 if (nlog_verbose == 0 && level > log_level)
461 return;
462
463 snprintf(tag, sizeof(tag), "%.48s:%.48s():%d (pid=%ld)",
464 (cp = strrchr(file, '/')) == NULL ? file : cp + 1, func, line,
465 (long)getpid());
466 for (i = 0; i < nlog_verbose; i++) {
467 if (match_pattern_list(tag, log_verbose[i], 0) == 1) {
468 forced = 1;
469 break;
470 }
471 }
472
473 if (forced)
474 snprintf(fmt2, sizeof(fmt2), "%s: %s", tag, fmt);
475 else if (showfunc)
476 snprintf(fmt2, sizeof(fmt2), "%s: %s", func, fmt);
477 else
478 strlcpy(fmt2, fmt, sizeof(fmt2));
479
480 do_log(level, forced, suffix, fmt2, args);
481 }
482
483 void
sshlogdirect(LogLevel level,int forced,const char * fmt,...)484 sshlogdirect(LogLevel level, int forced, const char *fmt, ...)
485 {
486 va_list args;
487
488 va_start(args, fmt);
489 do_log(level, forced, NULL, fmt, args);
490 va_end(args);
491 }
492