xref: /openbsd-src/usr.bin/ssh/log.c (revision 47911bd667ac77dc523b8a13ef40b012dbffa741)
1 /*
2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4  *                    All rights reserved
5  *
6  * As far as I am concerned, the code I have written for this software
7  * can be used freely for any purpose.  Any derived versions of this
8  * software must be clearly marked as such, and if the derived work is
9  * incompatible with the protocol description in the RFC file, it must be
10  * called by a name other than "ssh" or "Secure Shell".
11  */
12 /*
13  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #include "includes.h"
37 RCSID("$OpenBSD: log.c,v 1.24 2002/07/19 15:43:33 markus Exp $");
38 
39 #include "log.h"
40 #include "xmalloc.h"
41 
42 #include <syslog.h>
43 
44 static LogLevel log_level = SYSLOG_LEVEL_INFO;
45 static int log_on_stderr = 1;
46 static int log_facility = LOG_AUTH;
47 static char *argv0;
48 
49 extern char *__progname;
50 
51 /* textual representation of log-facilities/levels */
52 
53 static struct {
54 	const char *name;
55 	SyslogFacility val;
56 } log_facilities[] = {
57 	{ "DAEMON",	SYSLOG_FACILITY_DAEMON },
58 	{ "USER",	SYSLOG_FACILITY_USER },
59 	{ "AUTH",	SYSLOG_FACILITY_AUTH },
60 	{ "LOCAL0",	SYSLOG_FACILITY_LOCAL0 },
61 	{ "LOCAL1",	SYSLOG_FACILITY_LOCAL1 },
62 	{ "LOCAL2",	SYSLOG_FACILITY_LOCAL2 },
63 	{ "LOCAL3",	SYSLOG_FACILITY_LOCAL3 },
64 	{ "LOCAL4",	SYSLOG_FACILITY_LOCAL4 },
65 	{ "LOCAL5",	SYSLOG_FACILITY_LOCAL5 },
66 	{ "LOCAL6",	SYSLOG_FACILITY_LOCAL6 },
67 	{ "LOCAL7",	SYSLOG_FACILITY_LOCAL7 },
68 	{ NULL,		SYSLOG_FACILITY_NOT_SET }
69 };
70 
71 static struct {
72 	const char *name;
73 	LogLevel val;
74 } log_levels[] =
75 {
76 	{ "QUIET",	SYSLOG_LEVEL_QUIET },
77 	{ "FATAL",	SYSLOG_LEVEL_FATAL },
78 	{ "ERROR",	SYSLOG_LEVEL_ERROR },
79 	{ "INFO",	SYSLOG_LEVEL_INFO },
80 	{ "VERBOSE",	SYSLOG_LEVEL_VERBOSE },
81 	{ "DEBUG",	SYSLOG_LEVEL_DEBUG1 },
82 	{ "DEBUG1",	SYSLOG_LEVEL_DEBUG1 },
83 	{ "DEBUG2",	SYSLOG_LEVEL_DEBUG2 },
84 	{ "DEBUG3",	SYSLOG_LEVEL_DEBUG3 },
85 	{ NULL,		SYSLOG_LEVEL_NOT_SET }
86 };
87 
88 SyslogFacility
89 log_facility_number(char *name)
90 {
91 	int i;
92 
93 	if (name != NULL)
94 		for (i = 0; log_facilities[i].name; i++)
95 			if (strcasecmp(log_facilities[i].name, name) == 0)
96 				return log_facilities[i].val;
97 	return SYSLOG_FACILITY_NOT_SET;
98 }
99 
100 LogLevel
101 log_level_number(char *name)
102 {
103 	int i;
104 
105 	if (name != NULL)
106 		for (i = 0; log_levels[i].name; i++)
107 			if (strcasecmp(log_levels[i].name, name) == 0)
108 				return log_levels[i].val;
109 	return SYSLOG_LEVEL_NOT_SET;
110 }
111 
112 /* Error messages that should be logged. */
113 
114 void
115 error(const char *fmt,...)
116 {
117 	va_list args;
118 
119 	va_start(args, fmt);
120 	do_log(SYSLOG_LEVEL_ERROR, fmt, args);
121 	va_end(args);
122 }
123 
124 /* Log this message (information that usually should go to the log). */
125 
126 void
127 log(const char *fmt,...)
128 {
129 	va_list args;
130 
131 	va_start(args, fmt);
132 	do_log(SYSLOG_LEVEL_INFO, fmt, args);
133 	va_end(args);
134 }
135 
136 /* More detailed messages (information that does not need to go to the log). */
137 
138 void
139 verbose(const char *fmt,...)
140 {
141 	va_list args;
142 
143 	va_start(args, fmt);
144 	do_log(SYSLOG_LEVEL_VERBOSE, fmt, args);
145 	va_end(args);
146 }
147 
148 /* Debugging messages that should not be logged during normal operation. */
149 
150 void
151 debug(const char *fmt,...)
152 {
153 	va_list args;
154 
155 	va_start(args, fmt);
156 	do_log(SYSLOG_LEVEL_DEBUG1, fmt, args);
157 	va_end(args);
158 }
159 
160 void
161 debug2(const char *fmt,...)
162 {
163 	va_list args;
164 
165 	va_start(args, fmt);
166 	do_log(SYSLOG_LEVEL_DEBUG2, fmt, args);
167 	va_end(args);
168 }
169 
170 void
171 debug3(const char *fmt,...)
172 {
173 	va_list args;
174 
175 	va_start(args, fmt);
176 	do_log(SYSLOG_LEVEL_DEBUG3, fmt, args);
177 	va_end(args);
178 }
179 
180 /* Fatal cleanup */
181 
182 struct fatal_cleanup {
183 	struct fatal_cleanup *next;
184 	void (*proc) (void *);
185 	void *context;
186 };
187 
188 static struct fatal_cleanup *fatal_cleanups = NULL;
189 
190 /* Registers a cleanup function to be called by fatal() before exiting. */
191 
192 void
193 fatal_add_cleanup(void (*proc) (void *), void *context)
194 {
195 	struct fatal_cleanup *cu;
196 
197 	cu = xmalloc(sizeof(*cu));
198 	cu->proc = proc;
199 	cu->context = context;
200 	cu->next = fatal_cleanups;
201 	fatal_cleanups = cu;
202 }
203 
204 /* Removes a cleanup frunction to be called at fatal(). */
205 
206 void
207 fatal_remove_cleanup(void (*proc) (void *context), void *context)
208 {
209 	struct fatal_cleanup **cup, *cu;
210 
211 	for (cup = &fatal_cleanups; *cup; cup = &cu->next) {
212 		cu = *cup;
213 		if (cu->proc == proc && cu->context == context) {
214 			*cup = cu->next;
215 			xfree(cu);
216 			return;
217 		}
218 	}
219 	fatal("fatal_remove_cleanup: no such cleanup function: 0x%lx 0x%lx",
220 	    (u_long) proc, (u_long) context);
221 }
222 
223 /* Remove all cleanups, to be called after fork() */
224 void
225 fatal_remove_all_cleanups(void)
226 {
227 	struct fatal_cleanup *cu, *next_cu;
228 
229 	for (cu = fatal_cleanups; cu; cu = next_cu) {
230 		next_cu = cu->next;
231 		xfree(cu);
232 	}
233 }
234 
235 /* Cleanup and exit */
236 void
237 fatal_cleanup(void)
238 {
239 	struct fatal_cleanup *cu, *next_cu;
240 	static int called = 0;
241 
242 	if (called)
243 		exit(255);
244 	called = 1;
245 	/* Call cleanup functions. */
246 	for (cu = fatal_cleanups; cu; cu = next_cu) {
247 		next_cu = cu->next;
248 		debug("Calling cleanup 0x%lx(0x%lx)",
249 		    (u_long) cu->proc, (u_long) cu->context);
250 		(*cu->proc) (cu->context);
251 	}
252 	exit(255);
253 }
254 
255 
256 /*
257  * Initialize the log.
258  */
259 
260 void
261 log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr)
262 {
263 	argv0 = av0;
264 
265 	switch (level) {
266 	case SYSLOG_LEVEL_QUIET:
267 	case SYSLOG_LEVEL_FATAL:
268 	case SYSLOG_LEVEL_ERROR:
269 	case SYSLOG_LEVEL_INFO:
270 	case SYSLOG_LEVEL_VERBOSE:
271 	case SYSLOG_LEVEL_DEBUG1:
272 	case SYSLOG_LEVEL_DEBUG2:
273 	case SYSLOG_LEVEL_DEBUG3:
274 		log_level = level;
275 		break;
276 	default:
277 		fprintf(stderr, "Unrecognized internal syslog level code %d\n",
278 		    (int) level);
279 		exit(1);
280 	}
281 
282 	log_on_stderr = on_stderr;
283 	if (on_stderr)
284 		return;
285 
286 	switch (facility) {
287 	case SYSLOG_FACILITY_DAEMON:
288 		log_facility = LOG_DAEMON;
289 		break;
290 	case SYSLOG_FACILITY_USER:
291 		log_facility = LOG_USER;
292 		break;
293 	case SYSLOG_FACILITY_AUTH:
294 		log_facility = LOG_AUTH;
295 		break;
296 	case SYSLOG_FACILITY_LOCAL0:
297 		log_facility = LOG_LOCAL0;
298 		break;
299 	case SYSLOG_FACILITY_LOCAL1:
300 		log_facility = LOG_LOCAL1;
301 		break;
302 	case SYSLOG_FACILITY_LOCAL2:
303 		log_facility = LOG_LOCAL2;
304 		break;
305 	case SYSLOG_FACILITY_LOCAL3:
306 		log_facility = LOG_LOCAL3;
307 		break;
308 	case SYSLOG_FACILITY_LOCAL4:
309 		log_facility = LOG_LOCAL4;
310 		break;
311 	case SYSLOG_FACILITY_LOCAL5:
312 		log_facility = LOG_LOCAL5;
313 		break;
314 	case SYSLOG_FACILITY_LOCAL6:
315 		log_facility = LOG_LOCAL6;
316 		break;
317 	case SYSLOG_FACILITY_LOCAL7:
318 		log_facility = LOG_LOCAL7;
319 		break;
320 	default:
321 		fprintf(stderr,
322 		    "Unrecognized internal syslog facility code %d\n",
323 		    (int) facility);
324 		exit(1);
325 	}
326 }
327 
328 #define MSGBUFSIZ 1024
329 
330 void
331 do_log(LogLevel level, const char *fmt, va_list args)
332 {
333 	char msgbuf[MSGBUFSIZ];
334 	char fmtbuf[MSGBUFSIZ];
335 	char *txt = NULL;
336 	int pri = LOG_INFO;
337 
338 	if (level > log_level)
339 		return;
340 
341 	switch (level) {
342 	case SYSLOG_LEVEL_FATAL:
343 		if (!log_on_stderr)
344 			txt = "fatal";
345 		pri = LOG_CRIT;
346 		break;
347 	case SYSLOG_LEVEL_ERROR:
348 		if (!log_on_stderr)
349 			txt = "error";
350 		pri = LOG_ERR;
351 		break;
352 	case SYSLOG_LEVEL_INFO:
353 		pri = LOG_INFO;
354 		break;
355 	case SYSLOG_LEVEL_VERBOSE:
356 		pri = LOG_INFO;
357 		break;
358 	case SYSLOG_LEVEL_DEBUG1:
359 		txt = "debug1";
360 		pri = LOG_DEBUG;
361 		break;
362 	case SYSLOG_LEVEL_DEBUG2:
363 		txt = "debug2";
364 		pri = LOG_DEBUG;
365 		break;
366 	case SYSLOG_LEVEL_DEBUG3:
367 		txt = "debug3";
368 		pri = LOG_DEBUG;
369 		break;
370 	default:
371 		txt = "internal error";
372 		pri = LOG_ERR;
373 		break;
374 	}
375 	if (txt != NULL) {
376 		snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
377 		vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
378 	} else {
379 		vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
380 	}
381 	if (log_on_stderr) {
382 		fprintf(stderr, "%s\r\n", msgbuf);
383 	} else {
384 		openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
385 		syslog(pri, "%.500s", msgbuf);
386 		closelog();
387 	}
388 }
389