1/* $OpenBSD: log.c,v 1.43 2012/09/06 04:37:39 dtucker 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) && !defined(BROKEN_STRNVIS)
49# include <vis.h>
50#endif
51
52#include "xmalloc.h"
53#include "log.h"
54
55static LogLevel log_level = SYSLOG_LEVEL_INFO;
56static int log_on_stderr = 1;
57static int log_facility = LOG_AUTH;
58static char *argv0;
59static log_handler_fn *log_handler;
60static void *log_handler_ctx;
61
62extern 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
69static 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
90static 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
107SyslogFacility
108log_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
119const char *
120log_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
130LogLevel
131log_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
142const char *
143log_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
155void
156error(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
165void
166sigdie(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
181void
182logit(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
193void
194verbose(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
205void
206debug(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
215void
216debug2(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
225void
226debug3(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
239void
240log_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
332void
333log_change_level(LogLevel new_log_level)
334{
335	/* no-op if log_init has not been called */
336	if (argv0 == NULL)
337		return;
338	log_init(argv0, new_log_level, log_facility, log_on_stderr);
339}
340
341int
342log_is_on_stderr(void)
343{
344	return log_on_stderr;
345}
346
347#define MSGBUFSIZ 1024
348
349void
350set_log_handler(log_handler_fn *handler, void *ctx)
351{
352	log_handler = handler;
353	log_handler_ctx = ctx;
354}
355
356void
357do_log2(LogLevel level, const char *fmt,...)
358{
359	va_list args;
360
361	va_start(args, fmt);
362	do_log(level, fmt, args);
363	va_end(args);
364}
365
366void
367do_log(LogLevel level, const char *fmt, va_list args)
368{
369#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
370	struct syslog_data sdata = SYSLOG_DATA_INIT;
371#endif
372	char msgbuf[MSGBUFSIZ];
373	char fmtbuf[MSGBUFSIZ];
374	char *txt = NULL;
375	int pri = LOG_INFO;
376	int saved_errno = errno;
377	log_handler_fn *tmp_handler;
378
379	if (level > log_level)
380		return;
381
382	switch (level) {
383	case SYSLOG_LEVEL_FATAL:
384		if (!log_on_stderr)
385			txt = "fatal";
386		pri = LOG_CRIT;
387		break;
388	case SYSLOG_LEVEL_ERROR:
389		if (!log_on_stderr)
390			txt = "error";
391		pri = LOG_ERR;
392		break;
393	case SYSLOG_LEVEL_INFO:
394		pri = LOG_INFO;
395		break;
396	case SYSLOG_LEVEL_VERBOSE:
397		pri = LOG_INFO;
398		break;
399	case SYSLOG_LEVEL_DEBUG1:
400		txt = "debug1";
401		pri = LOG_DEBUG;
402		break;
403	case SYSLOG_LEVEL_DEBUG2:
404		txt = "debug2";
405		pri = LOG_DEBUG;
406		break;
407	case SYSLOG_LEVEL_DEBUG3:
408		txt = "debug3";
409		pri = LOG_DEBUG;
410		break;
411	default:
412		txt = "internal error";
413		pri = LOG_ERR;
414		break;
415	}
416	if (txt != NULL && log_handler == NULL) {
417		snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
418		vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
419	} else {
420		vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
421	}
422	strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
423	    log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
424	if (log_handler != NULL) {
425		/* Avoid recursion */
426		tmp_handler = log_handler;
427		log_handler = NULL;
428		tmp_handler(level, fmtbuf, log_handler_ctx);
429		log_handler = tmp_handler;
430	} else if (log_on_stderr) {
431		snprintf(msgbuf, sizeof msgbuf, "%s\r\n", fmtbuf);
432		write(STDERR_FILENO, msgbuf, strlen(msgbuf));
433	} else {
434#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
435		openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
436		syslog_r(pri, &sdata, "%.500s", fmtbuf);
437		closelog_r(&sdata);
438#else
439		openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
440		syslog(pri, "%.500s", fmtbuf);
441		closelog();
442#endif
443	}
444	errno = saved_errno;
445}
446