1/* $OpenBSD: log.c,v 1.45 2013/05/16 09:08:41 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 <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 "xmalloc.h"
54#include "log.h"
55
56static LogLevel log_level = SYSLOG_LEVEL_INFO;
57static int log_on_stderr = 1;
58static int log_stderr_fd = STDERR_FILENO;
59static int log_facility = LOG_AUTH;
60static char *argv0;
61static log_handler_fn *log_handler;
62static void *log_handler_ctx;
63
64extern char *__progname;
65
66#define LOG_SYSLOG_VIS	(VIS_CSTYLE|VIS_NL|VIS_TAB|VIS_OCTAL)
67#define LOG_STDERR_VIS	(VIS_SAFE|VIS_OCTAL)
68
69/* textual representation of log-facilities/levels */
70
71static struct {
72	const char *name;
73	SyslogFacility val;
74} log_facilities[] = {
75	{ "DAEMON",	SYSLOG_FACILITY_DAEMON },
76	{ "USER",	SYSLOG_FACILITY_USER },
77	{ "AUTH",	SYSLOG_FACILITY_AUTH },
78#ifdef LOG_AUTHPRIV
79	{ "AUTHPRIV",	SYSLOG_FACILITY_AUTHPRIV },
80#endif
81	{ "LOCAL0",	SYSLOG_FACILITY_LOCAL0 },
82	{ "LOCAL1",	SYSLOG_FACILITY_LOCAL1 },
83	{ "LOCAL2",	SYSLOG_FACILITY_LOCAL2 },
84	{ "LOCAL3",	SYSLOG_FACILITY_LOCAL3 },
85	{ "LOCAL4",	SYSLOG_FACILITY_LOCAL4 },
86	{ "LOCAL5",	SYSLOG_FACILITY_LOCAL5 },
87	{ "LOCAL6",	SYSLOG_FACILITY_LOCAL6 },
88	{ "LOCAL7",	SYSLOG_FACILITY_LOCAL7 },
89	{ NULL,		SYSLOG_FACILITY_NOT_SET }
90};
91
92static struct {
93	const char *name;
94	LogLevel val;
95} log_levels[] =
96{
97	{ "QUIET",	SYSLOG_LEVEL_QUIET },
98	{ "FATAL",	SYSLOG_LEVEL_FATAL },
99	{ "ERROR",	SYSLOG_LEVEL_ERROR },
100	{ "INFO",	SYSLOG_LEVEL_INFO },
101	{ "VERBOSE",	SYSLOG_LEVEL_VERBOSE },
102	{ "DEBUG",	SYSLOG_LEVEL_DEBUG1 },
103	{ "DEBUG1",	SYSLOG_LEVEL_DEBUG1 },
104	{ "DEBUG2",	SYSLOG_LEVEL_DEBUG2 },
105	{ "DEBUG3",	SYSLOG_LEVEL_DEBUG3 },
106	{ NULL,		SYSLOG_LEVEL_NOT_SET }
107};
108
109SyslogFacility
110log_facility_number(char *name)
111{
112	int i;
113
114	if (name != NULL)
115		for (i = 0; log_facilities[i].name; i++)
116			if (strcasecmp(log_facilities[i].name, name) == 0)
117				return log_facilities[i].val;
118	return SYSLOG_FACILITY_NOT_SET;
119}
120
121const char *
122log_facility_name(SyslogFacility facility)
123{
124	u_int i;
125
126	for (i = 0;  log_facilities[i].name; i++)
127		if (log_facilities[i].val == facility)
128			return log_facilities[i].name;
129	return NULL;
130}
131
132LogLevel
133log_level_number(char *name)
134{
135	int i;
136
137	if (name != NULL)
138		for (i = 0; log_levels[i].name; i++)
139			if (strcasecmp(log_levels[i].name, name) == 0)
140				return log_levels[i].val;
141	return SYSLOG_LEVEL_NOT_SET;
142}
143
144const char *
145log_level_name(LogLevel level)
146{
147	u_int i;
148
149	for (i = 0; log_levels[i].name != NULL; i++)
150		if (log_levels[i].val == level)
151			return log_levels[i].name;
152	return NULL;
153}
154
155/* Error messages that should be logged. */
156
157void
158error(const char *fmt,...)
159{
160	va_list args;
161
162	va_start(args, fmt);
163	do_log(SYSLOG_LEVEL_ERROR, fmt, args);
164	va_end(args);
165}
166
167void
168sigdie(const char *fmt,...)
169{
170#ifdef DO_LOG_SAFE_IN_SIGHAND
171	va_list args;
172
173	va_start(args, fmt);
174	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
175	va_end(args);
176#endif
177	_exit(1);
178}
179
180
181/* Log this message (information that usually should go to the log). */
182
183void
184logit(const char *fmt,...)
185{
186	va_list args;
187
188	va_start(args, fmt);
189	do_log(SYSLOG_LEVEL_INFO, fmt, args);
190	va_end(args);
191}
192
193/* More detailed messages (information that does not need to go to the log). */
194
195void
196verbose(const char *fmt,...)
197{
198	va_list args;
199
200	va_start(args, fmt);
201	do_log(SYSLOG_LEVEL_VERBOSE, fmt, args);
202	va_end(args);
203}
204
205/* Debugging messages that should not be logged during normal operation. */
206
207void
208debug(const char *fmt,...)
209{
210	va_list args;
211
212	va_start(args, fmt);
213	do_log(SYSLOG_LEVEL_DEBUG1, fmt, args);
214	va_end(args);
215}
216
217void
218debug2(const char *fmt,...)
219{
220	va_list args;
221
222	va_start(args, fmt);
223	do_log(SYSLOG_LEVEL_DEBUG2, fmt, args);
224	va_end(args);
225}
226
227void
228debug3(const char *fmt,...)
229{
230	va_list args;
231
232	va_start(args, fmt);
233	do_log(SYSLOG_LEVEL_DEBUG3, fmt, args);
234	va_end(args);
235}
236
237/*
238 * Initialize the log.
239 */
240
241void
242log_init(char *av0, LogLevel level, SyslogFacility facility, int on_stderr)
243{
244#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
245	struct syslog_data sdata = SYSLOG_DATA_INIT;
246#endif
247
248	argv0 = av0;
249
250	switch (level) {
251	case SYSLOG_LEVEL_QUIET:
252	case SYSLOG_LEVEL_FATAL:
253	case SYSLOG_LEVEL_ERROR:
254	case SYSLOG_LEVEL_INFO:
255	case SYSLOG_LEVEL_VERBOSE:
256	case SYSLOG_LEVEL_DEBUG1:
257	case SYSLOG_LEVEL_DEBUG2:
258	case SYSLOG_LEVEL_DEBUG3:
259		log_level = level;
260		break;
261	default:
262		fprintf(stderr, "Unrecognized internal syslog level code %d\n",
263		    (int) level);
264		exit(1);
265	}
266
267	log_handler = NULL;
268	log_handler_ctx = NULL;
269
270	log_on_stderr = on_stderr;
271	if (on_stderr)
272		return;
273
274	switch (facility) {
275	case SYSLOG_FACILITY_DAEMON:
276		log_facility = LOG_DAEMON;
277		break;
278	case SYSLOG_FACILITY_USER:
279		log_facility = LOG_USER;
280		break;
281	case SYSLOG_FACILITY_AUTH:
282		log_facility = LOG_AUTH;
283		break;
284#ifdef LOG_AUTHPRIV
285	case SYSLOG_FACILITY_AUTHPRIV:
286		log_facility = LOG_AUTHPRIV;
287		break;
288#endif
289	case SYSLOG_FACILITY_LOCAL0:
290		log_facility = LOG_LOCAL0;
291		break;
292	case SYSLOG_FACILITY_LOCAL1:
293		log_facility = LOG_LOCAL1;
294		break;
295	case SYSLOG_FACILITY_LOCAL2:
296		log_facility = LOG_LOCAL2;
297		break;
298	case SYSLOG_FACILITY_LOCAL3:
299		log_facility = LOG_LOCAL3;
300		break;
301	case SYSLOG_FACILITY_LOCAL4:
302		log_facility = LOG_LOCAL4;
303		break;
304	case SYSLOG_FACILITY_LOCAL5:
305		log_facility = LOG_LOCAL5;
306		break;
307	case SYSLOG_FACILITY_LOCAL6:
308		log_facility = LOG_LOCAL6;
309		break;
310	case SYSLOG_FACILITY_LOCAL7:
311		log_facility = LOG_LOCAL7;
312		break;
313	default:
314		fprintf(stderr,
315		    "Unrecognized internal syslog facility code %d\n",
316		    (int) facility);
317		exit(1);
318	}
319
320	/*
321	 * If an external library (eg libwrap) attempts to use syslog
322	 * immediately after reexec, syslog may be pointing to the wrong
323	 * facility, so we force an open/close of syslog here.
324	 */
325#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
326	openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
327	closelog_r(&sdata);
328#else
329	openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
330	closelog();
331#endif
332}
333
334void
335log_change_level(LogLevel new_log_level)
336{
337	/* no-op if log_init has not been called */
338	if (argv0 == NULL)
339		return;
340	log_init(argv0, new_log_level, log_facility, log_on_stderr);
341}
342
343int
344log_is_on_stderr(void)
345{
346	return log_on_stderr;
347}
348
349/* redirect what would usually get written to stderr to specified file */
350void
351log_redirect_stderr_to(const char *logfile)
352{
353	int fd;
354
355	if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
356		fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
357		     strerror(errno));
358		exit(1);
359	}
360	log_stderr_fd = fd;
361}
362
363#define MSGBUFSIZ 1024
364
365void
366set_log_handler(log_handler_fn *handler, void *ctx)
367{
368	log_handler = handler;
369	log_handler_ctx = ctx;
370}
371
372void
373do_log2(LogLevel level, const char *fmt,...)
374{
375	va_list args;
376
377	va_start(args, fmt);
378	do_log(level, fmt, args);
379	va_end(args);
380}
381
382void
383do_log(LogLevel level, const char *fmt, va_list args)
384{
385#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
386	struct syslog_data sdata = SYSLOG_DATA_INIT;
387#endif
388	char msgbuf[MSGBUFSIZ];
389	char fmtbuf[MSGBUFSIZ];
390	char *txt = NULL;
391	int pri = LOG_INFO;
392	int saved_errno = errno;
393	log_handler_fn *tmp_handler;
394
395	if (level > log_level)
396		return;
397
398	switch (level) {
399	case SYSLOG_LEVEL_FATAL:
400		if (!log_on_stderr)
401			txt = "fatal";
402		pri = LOG_CRIT;
403		break;
404	case SYSLOG_LEVEL_ERROR:
405		if (!log_on_stderr)
406			txt = "error";
407		pri = LOG_ERR;
408		break;
409	case SYSLOG_LEVEL_INFO:
410		pri = LOG_INFO;
411		break;
412	case SYSLOG_LEVEL_VERBOSE:
413		pri = LOG_INFO;
414		break;
415	case SYSLOG_LEVEL_DEBUG1:
416		txt = "debug1";
417		pri = LOG_DEBUG;
418		break;
419	case SYSLOG_LEVEL_DEBUG2:
420		txt = "debug2";
421		pri = LOG_DEBUG;
422		break;
423	case SYSLOG_LEVEL_DEBUG3:
424		txt = "debug3";
425		pri = LOG_DEBUG;
426		break;
427	default:
428		txt = "internal error";
429		pri = LOG_ERR;
430		break;
431	}
432	if (txt != NULL && log_handler == NULL) {
433		snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
434		vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
435	} else {
436		vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
437	}
438	strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
439	    log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
440	if (log_handler != NULL) {
441		/* Avoid recursion */
442		tmp_handler = log_handler;
443		log_handler = NULL;
444		tmp_handler(level, fmtbuf, log_handler_ctx);
445		log_handler = tmp_handler;
446	} else if (log_on_stderr) {
447		snprintf(msgbuf, sizeof msgbuf, "%s\r\n", fmtbuf);
448		(void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
449	} else {
450#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
451		openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
452		syslog_r(pri, &sdata, "%.500s", fmtbuf);
453		closelog_r(&sdata);
454#else
455		openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
456		syslog(pri, "%.500s", fmtbuf);
457		closelog();
458#endif
459	}
460	errno = saved_errno;
461}
462