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      1 /* $OpenBSD: log.c,v 1.42 2011/06/17 21:44:30 djm Exp $ */
      2 /*
      3  * Author: Tatu Ylonen <ylo (at) cs.hut.fi>
      4  * Copyright (c) 1995 Tatu Ylonen <ylo (at) 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)
     49 # include <vis.h>
     50 #endif
     51 
     52 #include "xmalloc.h"
     53 #include "log.h"
     54 
     55 static LogLevel log_level = SYSLOG_LEVEL_INFO;
     56 static int log_on_stderr = 1;
     57 static int log_facility = LOG_AUTH;
     58 static char *argv0;
     59 static log_handler_fn *log_handler;
     60 static void *log_handler_ctx;
     61 
     62 extern 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 
     69 static 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 
     90 static 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 
    107 SyslogFacility
    108 log_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 
    119 const char *
    120 log_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 
    130 LogLevel
    131 log_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 
    142 const char *
    143 log_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 
    155 void
    156 error(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 
    165 void
    166 sigdie(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 
    181 void
    182 logit(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 
    193 void
    194 verbose(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 
    205 void
    206 debug(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 
    215 void
    216 debug2(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 
    225 void
    226 debug3(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 
    239 void
    240 log_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 
    332 #define MSGBUFSIZ 1024
    333 
    334 void
    335 set_log_handler(log_handler_fn *handler, void *ctx)
    336 {
    337 	log_handler = handler;
    338 	log_handler_ctx = ctx;
    339 }
    340 
    341 void
    342 do_log2(LogLevel level, const char *fmt,...)
    343 {
    344 	va_list args;
    345 
    346 	va_start(args, fmt);
    347 	do_log(level, fmt, args);
    348 	va_end(args);
    349 }
    350 
    351 void
    352 do_log(LogLevel level, const char *fmt, va_list args)
    353 {
    354 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
    355 	struct syslog_data sdata = SYSLOG_DATA_INIT;
    356 #endif
    357 	char msgbuf[MSGBUFSIZ];
    358 	char fmtbuf[MSGBUFSIZ];
    359 	char *txt = NULL;
    360 	int pri = LOG_INFO;
    361 	int saved_errno = errno;
    362 	log_handler_fn *tmp_handler;
    363 
    364 	if (level > log_level)
    365 		return;
    366 
    367 	switch (level) {
    368 	case SYSLOG_LEVEL_FATAL:
    369 		if (!log_on_stderr)
    370 			txt = "fatal";
    371 		pri = LOG_CRIT;
    372 		break;
    373 	case SYSLOG_LEVEL_ERROR:
    374 		if (!log_on_stderr)
    375 			txt = "error";
    376 		pri = LOG_ERR;
    377 		break;
    378 	case SYSLOG_LEVEL_INFO:
    379 		pri = LOG_INFO;
    380 		break;
    381 	case SYSLOG_LEVEL_VERBOSE:
    382 		pri = LOG_INFO;
    383 		break;
    384 	case SYSLOG_LEVEL_DEBUG1:
    385 		txt = "debug1";
    386 		pri = LOG_DEBUG;
    387 		break;
    388 	case SYSLOG_LEVEL_DEBUG2:
    389 		txt = "debug2";
    390 		pri = LOG_DEBUG;
    391 		break;
    392 	case SYSLOG_LEVEL_DEBUG3:
    393 		txt = "debug3";
    394 		pri = LOG_DEBUG;
    395 		break;
    396 	default:
    397 		txt = "internal error";
    398 		pri = LOG_ERR;
    399 		break;
    400 	}
    401 	if (txt != NULL && log_handler == NULL) {
    402 		snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
    403 		vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
    404 	} else {
    405 		vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
    406 	}
    407 	strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
    408 	    log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
    409 	if (log_handler != NULL) {
    410 		/* Avoid recursion */
    411 		tmp_handler = log_handler;
    412 		log_handler = NULL;
    413 		tmp_handler(level, fmtbuf, log_handler_ctx);
    414 		log_handler = tmp_handler;
    415 	} else if (log_on_stderr) {
    416 		snprintf(msgbuf, sizeof msgbuf, "%s\r\n", fmtbuf);
    417 		write(STDERR_FILENO, msgbuf, strlen(msgbuf));
    418 	} else {
    419 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
    420 		openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
    421 		syslog_r(pri, &sdata, "%.500s", fmtbuf);
    422 		closelog_r(&sdata);
    423 #else
    424 		openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
    425 		syslog(pri, "%.500s", fmtbuf);
    426 		closelog();
    427 #endif
    428 	}
    429 	errno = saved_errno;
    430 }
    431