log.c revision 1.58 
1/* $OpenBSD: log.c,v 1.58 2021/04/15 16:24:31 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 <sys/types.h>
38
39#include <fcntl.h>
40#include <stdarg.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <syslog.h>
45#include <unistd.h>
46#include <errno.h>
47#include <vis.h>
48
49#include "log.h"
50#include "match.h"
51
52static LogLevel log_level = SYSLOG_LEVEL_INFO;
53static int log_on_stderr = 1;
54static int log_stderr_fd = STDERR_FILENO;
55static int log_facility = LOG_AUTH;
56static const char *argv0;
57static log_handler_fn *log_handler;
58static void *log_handler_ctx;
59static char **log_verbose;
60static size_t nlog_verbose;
61extern char *__progname;
62
63/* textual representation of log-facilities/levels */
64
65static struct {
66	const char *name;
67	SyslogFacility val;
68} log_facilities[] = {
69	{ "DAEMON",	SYSLOG_FACILITY_DAEMON },
70	{ "USER",	SYSLOG_FACILITY_USER },
71	{ "AUTH",	SYSLOG_FACILITY_AUTH },
72	{ "LOCAL0",	SYSLOG_FACILITY_LOCAL0 },
73	{ "LOCAL1",	SYSLOG_FACILITY_LOCAL1 },
74	{ "LOCAL2",	SYSLOG_FACILITY_LOCAL2 },
75	{ "LOCAL3",	SYSLOG_FACILITY_LOCAL3 },
76	{ "LOCAL4",	SYSLOG_FACILITY_LOCAL4 },
77	{ "LOCAL5",	SYSLOG_FACILITY_LOCAL5 },
78	{ "LOCAL6",	SYSLOG_FACILITY_LOCAL6 },
79	{ "LOCAL7",	SYSLOG_FACILITY_LOCAL7 },
80	{ NULL,		SYSLOG_FACILITY_NOT_SET }
81};
82
83static struct {
84	const char *name;
85	LogLevel val;
86} log_levels[] =
87{
88	{ "QUIET",	SYSLOG_LEVEL_QUIET },
89	{ "FATAL",	SYSLOG_LEVEL_FATAL },
90	{ "ERROR",	SYSLOG_LEVEL_ERROR },
91	{ "INFO",	SYSLOG_LEVEL_INFO },
92	{ "VERBOSE",	SYSLOG_LEVEL_VERBOSE },
93	{ "DEBUG",	SYSLOG_LEVEL_DEBUG1 },
94	{ "DEBUG1",	SYSLOG_LEVEL_DEBUG1 },
95	{ "DEBUG2",	SYSLOG_LEVEL_DEBUG2 },
96	{ "DEBUG3",	SYSLOG_LEVEL_DEBUG3 },
97	{ NULL,		SYSLOG_LEVEL_NOT_SET }
98};
99
100LogLevel
101log_level_get(void)
102{
103	return log_level;
104}
105
106SyslogFacility
107log_facility_number(char *name)
108{
109	int i;
110
111	if (name != NULL)
112		for (i = 0; log_facilities[i].name; i++)
113			if (strcasecmp(log_facilities[i].name, name) == 0)
114				return log_facilities[i].val;
115	return SYSLOG_FACILITY_NOT_SET;
116}
117
118const char *
119log_facility_name(SyslogFacility facility)
120{
121	u_int i;
122
123	for (i = 0;  log_facilities[i].name; i++)
124		if (log_facilities[i].val == facility)
125			return log_facilities[i].name;
126	return NULL;
127}
128
129LogLevel
130log_level_number(char *name)
131{
132	int i;
133
134	if (name != NULL)
135		for (i = 0; log_levels[i].name; i++)
136			if (strcasecmp(log_levels[i].name, name) == 0)
137				return log_levels[i].val;
138	return SYSLOG_LEVEL_NOT_SET;
139}
140
141const char *
142log_level_name(LogLevel level)
143{
144	u_int i;
145
146	for (i = 0; log_levels[i].name != NULL; i++)
147		if (log_levels[i].val == level)
148			return log_levels[i].name;
149	return NULL;
150}
151
152void
153log_verbose_add(const char *s)
154{
155	char **tmp;
156
157	/* Ignore failures here */
158	if ((tmp = recallocarray(log_verbose, nlog_verbose, nlog_verbose + 1,
159	    sizeof(*log_verbose))) != NULL) {
160		log_verbose = tmp;
161		if ((log_verbose[nlog_verbose] = strdup(s)) != NULL)
162			nlog_verbose++;
163	}
164}
165
166void
167log_verbose_reset(void)
168{
169	size_t i;
170
171	for (i = 0; i < nlog_verbose; i++)
172		free(log_verbose[i]);
173	free(log_verbose);
174	log_verbose = NULL;
175	nlog_verbose = 0;
176}
177
178/*
179 * Initialize the log.
180 */
181
182void
183log_init(const char *av0, LogLevel level, SyslogFacility facility,
184    int on_stderr)
185{
186	argv0 = av0;
187
188	if (log_change_level(level) != 0) {
189		fprintf(stderr, "Unrecognized internal syslog level code %d\n",
190		    (int) level);
191		exit(1);
192	}
193
194	log_handler = NULL;
195	log_handler_ctx = NULL;
196
197	log_on_stderr = on_stderr;
198	if (on_stderr)
199		return;
200
201	switch (facility) {
202	case SYSLOG_FACILITY_DAEMON:
203		log_facility = LOG_DAEMON;
204		break;
205	case SYSLOG_FACILITY_USER:
206		log_facility = LOG_USER;
207		break;
208	case SYSLOG_FACILITY_AUTH:
209		log_facility = LOG_AUTH;
210		break;
211	case SYSLOG_FACILITY_LOCAL0:
212		log_facility = LOG_LOCAL0;
213		break;
214	case SYSLOG_FACILITY_LOCAL1:
215		log_facility = LOG_LOCAL1;
216		break;
217	case SYSLOG_FACILITY_LOCAL2:
218		log_facility = LOG_LOCAL2;
219		break;
220	case SYSLOG_FACILITY_LOCAL3:
221		log_facility = LOG_LOCAL3;
222		break;
223	case SYSLOG_FACILITY_LOCAL4:
224		log_facility = LOG_LOCAL4;
225		break;
226	case SYSLOG_FACILITY_LOCAL5:
227		log_facility = LOG_LOCAL5;
228		break;
229	case SYSLOG_FACILITY_LOCAL6:
230		log_facility = LOG_LOCAL6;
231		break;
232	case SYSLOG_FACILITY_LOCAL7:
233		log_facility = LOG_LOCAL7;
234		break;
235	default:
236		fprintf(stderr,
237		    "Unrecognized internal syslog facility code %d\n",
238		    (int) facility);
239		exit(1);
240	}
241}
242
243int
244log_change_level(LogLevel new_log_level)
245{
246	/* no-op if log_init has not been called */
247	if (argv0 == NULL)
248		return 0;
249
250	switch (new_log_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 = new_log_level;
260		return 0;
261	default:
262		return -1;
263	}
264}
265
266int
267log_is_on_stderr(void)
268{
269	return log_on_stderr && log_stderr_fd == STDERR_FILENO;
270}
271
272/* redirect what would usually get written to stderr to specified file */
273void
274log_redirect_stderr_to(const char *logfile)
275{
276	int fd;
277
278	if (logfile == NULL) {
279		if (log_stderr_fd != STDERR_FILENO) {
280			close(log_stderr_fd);
281			log_stderr_fd = STDERR_FILENO;
282		}
283		return;
284	}
285
286	if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
287		fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
288		    strerror(errno));
289		exit(1);
290	}
291	log_stderr_fd = fd;
292}
293
294#define MSGBUFSIZ 1024
295
296void
297set_log_handler(log_handler_fn *handler, void *ctx)
298{
299	log_handler = handler;
300	log_handler_ctx = ctx;
301}
302
303static void
304do_log(LogLevel level, int force, const char *suffix, const char *fmt,
305    va_list args)
306{
307	struct syslog_data sdata = SYSLOG_DATA_INIT;
308	char msgbuf[MSGBUFSIZ];
309	char fmtbuf[MSGBUFSIZ];
310	char *txt = NULL;
311	int pri = LOG_INFO;
312	int saved_errno = errno;
313	log_handler_fn *tmp_handler;
314
315	if (!force && level > log_level)
316		return;
317
318	switch (level) {
319	case SYSLOG_LEVEL_FATAL:
320		if (!log_on_stderr)
321			txt = "fatal";
322		pri = LOG_CRIT;
323		break;
324	case SYSLOG_LEVEL_ERROR:
325		if (!log_on_stderr)
326			txt = "error";
327		pri = LOG_ERR;
328		break;
329	case SYSLOG_LEVEL_INFO:
330		pri = LOG_INFO;
331		break;
332	case SYSLOG_LEVEL_VERBOSE:
333		pri = LOG_INFO;
334		break;
335	case SYSLOG_LEVEL_DEBUG1:
336		txt = "debug1";
337		pri = LOG_DEBUG;
338		break;
339	case SYSLOG_LEVEL_DEBUG2:
340		txt = "debug2";
341		pri = LOG_DEBUG;
342		break;
343	case SYSLOG_LEVEL_DEBUG3:
344		txt = "debug3";
345		pri = LOG_DEBUG;
346		break;
347	default:
348		txt = "internal error";
349		pri = LOG_ERR;
350		break;
351	}
352	if (txt != NULL && log_handler == NULL) {
353		snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
354		vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
355	} else {
356		vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
357	}
358	if (suffix != NULL) {
359		snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", msgbuf, suffix);
360		strlcpy(msgbuf, fmtbuf, sizeof(msgbuf));
361	}
362	strnvis(fmtbuf, msgbuf, sizeof(fmtbuf), VIS_SAFE|VIS_OCTAL);
363	if (log_handler != NULL) {
364		/* Avoid recursion */
365		tmp_handler = log_handler;
366		log_handler = NULL;
367		tmp_handler(level, force, fmtbuf, log_handler_ctx);
368		log_handler = tmp_handler;
369	} else if (log_on_stderr) {
370		snprintf(msgbuf, sizeof msgbuf, "%.*s\r\n",
371		    (int)sizeof msgbuf - 3, fmtbuf);
372		(void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
373	} else {
374		openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
375		syslog_r(pri, &sdata, "%.500s", fmtbuf);
376		closelog_r(&sdata);
377	}
378	errno = saved_errno;
379}
380
381void
382sshlog(const char *file, const char *func, int line, int showfunc,
383    LogLevel level, const char *suffix, const char *fmt, ...)
384{
385	va_list args;
386
387	va_start(args, fmt);
388	sshlogv(file, func, line, showfunc, level, suffix, fmt, args);
389	va_end(args);
390}
391
392void
393sshlogdie(const char *file, const char *func, int line, int showfunc,
394    LogLevel level, const char *suffix, const char *fmt, ...)
395{
396	va_list args;
397
398	va_start(args, fmt);
399	sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_INFO,
400	    suffix, fmt, args);
401	va_end(args);
402	cleanup_exit(255);
403}
404
405void
406sshsigdie(const char *file, const char *func, int line, int showfunc,
407    LogLevel level, const char *suffix, const char *fmt, ...)
408{
409	va_list args;
410
411	va_start(args, fmt);
412	sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_FATAL,
413	    suffix, fmt, args);
414	va_end(args);
415	_exit(1);
416}
417
418void
419sshlogv(const char *file, const char *func, int line, int showfunc,
420    LogLevel level, const char *suffix, const char *fmt, va_list args)
421{
422	char tag[128], fmt2[MSGBUFSIZ + 128];
423	int forced = 0;
424	const char *cp;
425	size_t i;
426
427	snprintf(tag, sizeof(tag), "%.48s:%.48s():%d",
428	    (cp = strrchr(file, '/')) == NULL ? file : cp + 1, func, line);
429	for (i = 0; i < nlog_verbose; i++) {
430		if (match_pattern_list(tag, log_verbose[i], 0) == 1) {
431			forced = 1;
432			break;
433		}
434	}
435
436	if (forced)
437		snprintf(fmt2, sizeof(fmt2), "%s: %s", tag, fmt);
438	else if (showfunc)
439		snprintf(fmt2, sizeof(fmt2), "%s: %s", func, fmt);
440	else
441		strlcpy(fmt2, fmt, sizeof(fmt2));
442
443	do_log(level, forced, suffix, fmt2, args);
444}
445
446void
447sshlogdirect(LogLevel level, int forced, const char *fmt, ...)
448{
449	va_list args;
450
451	va_start(args, fmt);
452	do_log(level, forced, NULL, fmt, args);
453	va_end(args);
454}
455