xref: /freebsd/crypto/openssh/log.c (revision 2a664c03e55254b0f3b32dcdfc78179c0a57a8d2)
1 /* $OpenBSD: log.c,v 1.42 2011/06/17 21:44:30 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 <stdarg.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <syslog.h>
46 #include <unistd.h>
47 #include <errno.h>
48 #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H)
49 # include <vis.h>
50 #endif
51 
52 #include "xmalloc.h"
53 #include "log.h"
54 
55 static LogLevel log_level = SYSLOG_LEVEL_INFO;
56 static int log_on_stderr = 1;
57 static int log_facility = LOG_AUTH;
58 static char *argv0;
59 static log_handler_fn *log_handler;
60 static void *log_handler_ctx;
61 
62 extern char *__progname;
63 
64 #define LOG_SYSLOG_VIS	(VIS_CSTYLE|VIS_NL|VIS_TAB|VIS_OCTAL)
65 #define LOG_STDERR_VIS	(VIS_SAFE|VIS_OCTAL)
66 
67 /* textual representation of log-facilities/levels */
68 
69 static struct {
70 	const char *name;
71 	SyslogFacility val;
72 } log_facilities[] = {
73 	{ "DAEMON",	SYSLOG_FACILITY_DAEMON },
74 	{ "USER",	SYSLOG_FACILITY_USER },
75 	{ "AUTH",	SYSLOG_FACILITY_AUTH },
76 #ifdef LOG_AUTHPRIV
77 	{ "AUTHPRIV",	SYSLOG_FACILITY_AUTHPRIV },
78 #endif
79 	{ "LOCAL0",	SYSLOG_FACILITY_LOCAL0 },
80 	{ "LOCAL1",	SYSLOG_FACILITY_LOCAL1 },
81 	{ "LOCAL2",	SYSLOG_FACILITY_LOCAL2 },
82 	{ "LOCAL3",	SYSLOG_FACILITY_LOCAL3 },
83 	{ "LOCAL4",	SYSLOG_FACILITY_LOCAL4 },
84 	{ "LOCAL5",	SYSLOG_FACILITY_LOCAL5 },
85 	{ "LOCAL6",	SYSLOG_FACILITY_LOCAL6 },
86 	{ "LOCAL7",	SYSLOG_FACILITY_LOCAL7 },
87 	{ NULL,		SYSLOG_FACILITY_NOT_SET }
88 };
89 
90 static struct {
91 	const char *name;
92 	LogLevel val;
93 } log_levels[] =
94 {
95 	{ "QUIET",	SYSLOG_LEVEL_QUIET },
96 	{ "FATAL",	SYSLOG_LEVEL_FATAL },
97 	{ "ERROR",	SYSLOG_LEVEL_ERROR },
98 	{ "INFO",	SYSLOG_LEVEL_INFO },
99 	{ "VERBOSE",	SYSLOG_LEVEL_VERBOSE },
100 	{ "DEBUG",	SYSLOG_LEVEL_DEBUG1 },
101 	{ "DEBUG1",	SYSLOG_LEVEL_DEBUG1 },
102 	{ "DEBUG2",	SYSLOG_LEVEL_DEBUG2 },
103 	{ "DEBUG3",	SYSLOG_LEVEL_DEBUG3 },
104 	{ NULL,		SYSLOG_LEVEL_NOT_SET }
105 };
106 
107 SyslogFacility
108 log_facility_number(char *name)
109 {
110 	int i;
111 
112 	if (name != NULL)
113 		for (i = 0; log_facilities[i].name; i++)
114 			if (strcasecmp(log_facilities[i].name, name) == 0)
115 				return log_facilities[i].val;
116 	return SYSLOG_FACILITY_NOT_SET;
117 }
118 
119 const char *
120 log_facility_name(SyslogFacility facility)
121 {
122 	u_int i;
123 
124 	for (i = 0;  log_facilities[i].name; i++)
125 		if (log_facilities[i].val == facility)
126 			return log_facilities[i].name;
127 	return NULL;
128 }
129 
130 LogLevel
131 log_level_number(char *name)
132 {
133 	int i;
134 
135 	if (name != NULL)
136 		for (i = 0; log_levels[i].name; i++)
137 			if (strcasecmp(log_levels[i].name, name) == 0)
138 				return log_levels[i].val;
139 	return SYSLOG_LEVEL_NOT_SET;
140 }
141 
142 const char *
143 log_level_name(LogLevel level)
144 {
145 	u_int i;
146 
147 	for (i = 0; log_levels[i].name != NULL; i++)
148 		if (log_levels[i].val == level)
149 			return log_levels[i].name;
150 	return NULL;
151 }
152 
153 /* Error messages that should be logged. */
154 
155 void
156 error(const char *fmt,...)
157 {
158 	va_list args;
159 
160 	va_start(args, fmt);
161 	do_log(SYSLOG_LEVEL_ERROR, fmt, args);
162 	va_end(args);
163 }
164 
165 void
166 sigdie(const char *fmt,...)
167 {
168 #ifdef DO_LOG_SAFE_IN_SIGHAND
169 	va_list args;
170 
171 	va_start(args, fmt);
172 	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
173 	va_end(args);
174 #endif
175 	_exit(1);
176 }
177 
178 
179 /* Log this message (information that usually should go to the log). */
180 
181 void
182 logit(const char *fmt,...)
183 {
184 	va_list args;
185 
186 	va_start(args, fmt);
187 	do_log(SYSLOG_LEVEL_INFO, fmt, args);
188 	va_end(args);
189 }
190 
191 /* More detailed messages (information that does not need to go to the log). */
192 
193 void
194 verbose(const char *fmt,...)
195 {
196 	va_list args;
197 
198 	va_start(args, fmt);
199 	do_log(SYSLOG_LEVEL_VERBOSE, fmt, args);
200 	va_end(args);
201 }
202 
203 /* Debugging messages that should not be logged during normal operation. */
204 
205 void
206 debug(const char *fmt,...)
207 {
208 	va_list args;
209 
210 	va_start(args, fmt);
211 	do_log(SYSLOG_LEVEL_DEBUG1, fmt, args);
212 	va_end(args);
213 }
214 
215 void
216 debug2(const char *fmt,...)
217 {
218 	va_list args;
219 
220 	va_start(args, fmt);
221 	do_log(SYSLOG_LEVEL_DEBUG2, fmt, args);
222 	va_end(args);
223 }
224 
225 void
226 debug3(const char *fmt,...)
227 {
228 	va_list args;
229 
230 	va_start(args, fmt);
231 	do_log(SYSLOG_LEVEL_DEBUG3, fmt, args);
232 	va_end(args);
233 }
234 
235 /*
236  * Initialize the log.
237  */
238 
239 void
240 log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr)
241 {
242 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
243 	struct syslog_data sdata = SYSLOG_DATA_INIT;
244 #endif
245 
246 	argv0 = av0;
247 
248 	switch (level) {
249 	case SYSLOG_LEVEL_QUIET:
250 	case SYSLOG_LEVEL_FATAL:
251 	case SYSLOG_LEVEL_ERROR:
252 	case SYSLOG_LEVEL_INFO:
253 	case SYSLOG_LEVEL_VERBOSE:
254 	case SYSLOG_LEVEL_DEBUG1:
255 	case SYSLOG_LEVEL_DEBUG2:
256 	case SYSLOG_LEVEL_DEBUG3:
257 		log_level = level;
258 		break;
259 	default:
260 		fprintf(stderr, "Unrecognized internal syslog level code %d\n",
261 		    (int) level);
262 		exit(1);
263 	}
264 
265 	log_handler = NULL;
266 	log_handler_ctx = NULL;
267 
268 	log_on_stderr = on_stderr;
269 	if (on_stderr)
270 		return;
271 
272 	switch (facility) {
273 	case SYSLOG_FACILITY_DAEMON:
274 		log_facility = LOG_DAEMON;
275 		break;
276 	case SYSLOG_FACILITY_USER:
277 		log_facility = LOG_USER;
278 		break;
279 	case SYSLOG_FACILITY_AUTH:
280 		log_facility = LOG_AUTH;
281 		break;
282 #ifdef LOG_AUTHPRIV
283 	case SYSLOG_FACILITY_AUTHPRIV:
284 		log_facility = LOG_AUTHPRIV;
285 		break;
286 #endif
287 	case SYSLOG_FACILITY_LOCAL0:
288 		log_facility = LOG_LOCAL0;
289 		break;
290 	case SYSLOG_FACILITY_LOCAL1:
291 		log_facility = LOG_LOCAL1;
292 		break;
293 	case SYSLOG_FACILITY_LOCAL2:
294 		log_facility = LOG_LOCAL2;
295 		break;
296 	case SYSLOG_FACILITY_LOCAL3:
297 		log_facility = LOG_LOCAL3;
298 		break;
299 	case SYSLOG_FACILITY_LOCAL4:
300 		log_facility = LOG_LOCAL4;
301 		break;
302 	case SYSLOG_FACILITY_LOCAL5:
303 		log_facility = LOG_LOCAL5;
304 		break;
305 	case SYSLOG_FACILITY_LOCAL6:
306 		log_facility = LOG_LOCAL6;
307 		break;
308 	case SYSLOG_FACILITY_LOCAL7:
309 		log_facility = LOG_LOCAL7;
310 		break;
311 	default:
312 		fprintf(stderr,
313 		    "Unrecognized internal syslog facility code %d\n",
314 		    (int) facility);
315 		exit(1);
316 	}
317 
318 	/*
319 	 * If an external library (eg libwrap) attempts to use syslog
320 	 * immediately after reexec, syslog may be pointing to the wrong
321 	 * facility, so we force an open/close of syslog here.
322 	 */
323 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
324 	openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
325 	closelog_r(&sdata);
326 #else
327 	openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
328 	closelog();
329 #endif
330 }
331 
332 #define MSGBUFSIZ 1024
333 
334 void
335 set_log_handler(log_handler_fn *handler, void *ctx)
336 {
337 	log_handler = handler;
338 	log_handler_ctx = ctx;
339 }
340 
341 void
342 do_log2(LogLevel level, const char *fmt,...)
343 {
344 	va_list args;
345 
346 	va_start(args, fmt);
347 	do_log(level, fmt, args);
348 	va_end(args);
349 }
350 
351 void
352 do_log(LogLevel level, const char *fmt, va_list args)
353 {
354 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
355 	struct syslog_data sdata = SYSLOG_DATA_INIT;
356 #endif
357 	char msgbuf[MSGBUFSIZ];
358 	char fmtbuf[MSGBUFSIZ];
359 	char *txt = NULL;
360 	int pri = LOG_INFO;
361 	int saved_errno = errno;
362 	log_handler_fn *tmp_handler;
363 
364 	if (level > log_level)
365 		return;
366 
367 	switch (level) {
368 	case SYSLOG_LEVEL_FATAL:
369 		if (!log_on_stderr)
370 			txt = "fatal";
371 		pri = LOG_CRIT;
372 		break;
373 	case SYSLOG_LEVEL_ERROR:
374 		if (!log_on_stderr)
375 			txt = "error";
376 		pri = LOG_ERR;
377 		break;
378 	case SYSLOG_LEVEL_INFO:
379 		pri = LOG_INFO;
380 		break;
381 	case SYSLOG_LEVEL_VERBOSE:
382 		pri = LOG_INFO;
383 		break;
384 	case SYSLOG_LEVEL_DEBUG1:
385 		txt = "debug1";
386 		pri = LOG_DEBUG;
387 		break;
388 	case SYSLOG_LEVEL_DEBUG2:
389 		txt = "debug2";
390 		pri = LOG_DEBUG;
391 		break;
392 	case SYSLOG_LEVEL_DEBUG3:
393 		txt = "debug3";
394 		pri = LOG_DEBUG;
395 		break;
396 	default:
397 		txt = "internal error";
398 		pri = LOG_ERR;
399 		break;
400 	}
401 	if (txt != NULL && log_handler == NULL) {
402 		snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
403 		vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
404 	} else {
405 		vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
406 	}
407 	strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
408 	    log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
409 	if (log_handler != NULL) {
410 		/* Avoid recursion */
411 		tmp_handler = log_handler;
412 		log_handler = NULL;
413 		tmp_handler(level, fmtbuf, log_handler_ctx);
414 		log_handler = tmp_handler;
415 	} else if (log_on_stderr) {
416 		snprintf(msgbuf, sizeof msgbuf, "%s\r\n", fmtbuf);
417 		write(STDERR_FILENO, msgbuf, strlen(msgbuf));
418 	} else {
419 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
420 		openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
421 		syslog_r(pri, &sdata, "%.500s", fmtbuf);
422 		closelog_r(&sdata);
423 #else
424 		openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
425 		syslog(pri, "%.500s", fmtbuf);
426 		closelog();
427 #endif
428 	}
429 	errno = saved_errno;
430 }
431