log.c revision 295367 
1/* $OpenBSD: log.c,v 1.46 2015/07/08 19:04:21 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
55static LogLevel log_level = SYSLOG_LEVEL_INFO;
56static int log_on_stderr = 1;
57static int log_stderr_fd = STDERR_FILENO;
58static int log_facility = LOG_AUTH;
59static char *argv0;
60static log_handler_fn *log_handler;
61static void *log_handler_ctx;
62
63extern 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
70static 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
91static 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
108SyslogFacility
109log_facility_number(char *name)
110{
111	int i;
112
113	if (name != NULL)
114		for (i = 0; log_facilities[i].name; i++)
115			if (strcasecmp(log_facilities[i].name, name) == 0)
116				return log_facilities[i].val;
117	return SYSLOG_FACILITY_NOT_SET;
118}
119
120const char *
121log_facility_name(SyslogFacility facility)
122{
123	u_int i;
124
125	for (i = 0;  log_facilities[i].name; i++)
126		if (log_facilities[i].val == facility)
127			return log_facilities[i].name;
128	return NULL;
129}
130
131LogLevel
132log_level_number(char *name)
133{
134	int i;
135
136	if (name != NULL)
137		for (i = 0; log_levels[i].name; i++)
138			if (strcasecmp(log_levels[i].name, name) == 0)
139				return log_levels[i].val;
140	return SYSLOG_LEVEL_NOT_SET;
141}
142
143const char *
144log_level_name(LogLevel level)
145{
146	u_int i;
147
148	for (i = 0; log_levels[i].name != NULL; i++)
149		if (log_levels[i].val == level)
150			return log_levels[i].name;
151	return NULL;
152}
153
154/* Error messages that should be logged. */
155
156void
157error(const char *fmt,...)
158{
159	va_list args;
160
161	va_start(args, fmt);
162	do_log(SYSLOG_LEVEL_ERROR, fmt, args);
163	va_end(args);
164}
165
166void
167sigdie(const char *fmt,...)
168{
169#ifdef DO_LOG_SAFE_IN_SIGHAND
170	va_list args;
171
172	va_start(args, fmt);
173	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
174	va_end(args);
175#endif
176	_exit(1);
177}
178
179
180/* Log this message (information that usually should go to the log). */
181
182void
183logit(const char *fmt,...)
184{
185	va_list args;
186
187	va_start(args, fmt);
188	do_log(SYSLOG_LEVEL_INFO, fmt, args);
189	va_end(args);
190}
191
192/* More detailed messages (information that does not need to go to the log). */
193
194void
195verbose(const char *fmt,...)
196{
197	va_list args;
198
199	va_start(args, fmt);
200	do_log(SYSLOG_LEVEL_VERBOSE, fmt, args);
201	va_end(args);
202}
203
204/* Debugging messages that should not be logged during normal operation. */
205
206void
207debug(const char *fmt,...)
208{
209	va_list args;
210
211	va_start(args, fmt);
212	do_log(SYSLOG_LEVEL_DEBUG1, fmt, args);
213	va_end(args);
214}
215
216void
217debug2(const char *fmt,...)
218{
219	va_list args;
220
221	va_start(args, fmt);
222	do_log(SYSLOG_LEVEL_DEBUG2, fmt, args);
223	va_end(args);
224}
225
226void
227debug3(const char *fmt,...)
228{
229	va_list args;
230
231	va_start(args, fmt);
232	do_log(SYSLOG_LEVEL_DEBUG3, fmt, args);
233	va_end(args);
234}
235
236/*
237 * Initialize the log.
238 */
239
240void
241log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr)
242{
243#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
244	struct syslog_data sdata = SYSLOG_DATA_INIT;
245#endif
246
247	argv0 = av0;
248
249	switch (level) {
250	case SYSLOG_LEVEL_QUIET:
251	case SYSLOG_LEVEL_FATAL:
252	case SYSLOG_LEVEL_ERROR:
253	case SYSLOG_LEVEL_INFO:
254	case SYSLOG_LEVEL_VERBOSE:
255	case SYSLOG_LEVEL_DEBUG1:
256	case SYSLOG_LEVEL_DEBUG2:
257	case SYSLOG_LEVEL_DEBUG3:
258		log_level = level;
259		break;
260	default:
261		fprintf(stderr, "Unrecognized internal syslog level code %d\n",
262		    (int) level);
263		exit(1);
264	}
265
266	log_handler = NULL;
267	log_handler_ctx = NULL;
268
269	log_on_stderr = on_stderr;
270	if (on_stderr)
271		return;
272
273	switch (facility) {
274	case SYSLOG_FACILITY_DAEMON:
275		log_facility = LOG_DAEMON;
276		break;
277	case SYSLOG_FACILITY_USER:
278		log_facility = LOG_USER;
279		break;
280	case SYSLOG_FACILITY_AUTH:
281		log_facility = LOG_AUTH;
282		break;
283#ifdef LOG_AUTHPRIV
284	case SYSLOG_FACILITY_AUTHPRIV:
285		log_facility = LOG_AUTHPRIV;
286		break;
287#endif
288	case SYSLOG_FACILITY_LOCAL0:
289		log_facility = LOG_LOCAL0;
290		break;
291	case SYSLOG_FACILITY_LOCAL1:
292		log_facility = LOG_LOCAL1;
293		break;
294	case SYSLOG_FACILITY_LOCAL2:
295		log_facility = LOG_LOCAL2;
296		break;
297	case SYSLOG_FACILITY_LOCAL3:
298		log_facility = LOG_LOCAL3;
299		break;
300	case SYSLOG_FACILITY_LOCAL4:
301		log_facility = LOG_LOCAL4;
302		break;
303	case SYSLOG_FACILITY_LOCAL5:
304		log_facility = LOG_LOCAL5;
305		break;
306	case SYSLOG_FACILITY_LOCAL6:
307		log_facility = LOG_LOCAL6;
308		break;
309	case SYSLOG_FACILITY_LOCAL7:
310		log_facility = LOG_LOCAL7;
311		break;
312	default:
313		fprintf(stderr,
314		    "Unrecognized internal syslog facility code %d\n",
315		    (int) facility);
316		exit(1);
317	}
318
319	/*
320	 * If an external library (eg libwrap) attempts to use syslog
321	 * immediately after reexec, syslog may be pointing to the wrong
322	 * facility, so we force an open/close of syslog here.
323	 */
324#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
325	openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
326	closelog_r(&sdata);
327#else
328	openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
329	closelog();
330#endif
331}
332
333void
334log_change_level(LogLevel new_log_level)
335{
336	/* no-op if log_init has not been called */
337	if (argv0 == NULL)
338		return;
339	log_init(argv0, new_log_level, log_facility, log_on_stderr);
340}
341
342int
343log_is_on_stderr(void)
344{
345	return log_on_stderr;
346}
347
348/* redirect what would usually get written to stderr to specified file */
349void
350log_redirect_stderr_to(const char *logfile)
351{
352	int fd;
353
354	if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
355		fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
356		     strerror(errno));
357		exit(1);
358	}
359	log_stderr_fd = fd;
360}
361
362#define MSGBUFSIZ 1024
363
364void
365set_log_handler(log_handler_fn *handler, void *ctx)
366{
367	log_handler = handler;
368	log_handler_ctx = ctx;
369}
370
371void
372do_log2(LogLevel level, const char *fmt,...)
373{
374	va_list args;
375
376	va_start(args, fmt);
377	do_log(level, fmt, args);
378	va_end(args);
379}
380
381void
382do_log(LogLevel level, const char *fmt, va_list args)
383{
384#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
385	struct syslog_data sdata = SYSLOG_DATA_INIT;
386#endif
387	char msgbuf[MSGBUFSIZ];
388	char fmtbuf[MSGBUFSIZ];
389	char *txt = NULL;
390	int pri = LOG_INFO;
391	int saved_errno = errno;
392	log_handler_fn *tmp_handler;
393
394	if (level > log_level)
395		return;
396
397	switch (level) {
398	case SYSLOG_LEVEL_FATAL:
399		if (!log_on_stderr)
400			txt = "fatal";
401		pri = LOG_CRIT;
402		break;
403	case SYSLOG_LEVEL_ERROR:
404		if (!log_on_stderr)
405			txt = "error";
406		pri = LOG_ERR;
407		break;
408	case SYSLOG_LEVEL_INFO:
409		pri = LOG_INFO;
410		break;
411	case SYSLOG_LEVEL_VERBOSE:
412		pri = LOG_INFO;
413		break;
414	case SYSLOG_LEVEL_DEBUG1:
415		txt = "debug1";
416		pri = LOG_DEBUG;
417		break;
418	case SYSLOG_LEVEL_DEBUG2:
419		txt = "debug2";
420		pri = LOG_DEBUG;
421		break;
422	case SYSLOG_LEVEL_DEBUG3:
423		txt = "debug3";
424		pri = LOG_DEBUG;
425		break;
426	default:
427		txt = "internal error";
428		pri = LOG_ERR;
429		break;
430	}
431	if (txt != NULL && log_handler == NULL) {
432		snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
433		vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
434	} else {
435		vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
436	}
437	strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
438	    log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
439	if (log_handler != NULL) {
440		/* Avoid recursion */
441		tmp_handler = log_handler;
442		log_handler = NULL;
443		tmp_handler(level, fmtbuf, log_handler_ctx);
444		log_handler = tmp_handler;
445	} else if (log_on_stderr) {
446		snprintf(msgbuf, sizeof msgbuf, "%s\r\n", fmtbuf);
447		(void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
448	} else {
449#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
450		openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
451		syslog_r(pri, &sdata, "%.500s", fmtbuf);
452		closelog_r(&sdata);
453#else
454		openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
455		syslog(pri, "%.500s", fmtbuf);
456		closelog();
457#endif
458	}
459	errno = saved_errno;
460}
461