log.c - platform/external/openssh - Git at Google

 /* $OpenBSD: log.c,v 1.60 2021/09/16 15:11:19 djm Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
  *                    All rights reserved
  *
  * As far as I am concerned, the code I have written for this software
  * can be used freely for any purpose.  Any derived versions of this
  * software must be clearly marked as such, and if the derived work is
  * incompatible with the protocol description in the RFC file, it must be
  * called by a name other than "ssh" or "Secure Shell".
  */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "includes.h"

 #include <sys/types.h>

 #include <fcntl.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <syslog.h>
 #include <unistd.h>
 #include <errno.h>
 #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
 # include <vis.h>
 #endif

 #include "log.h"
 #include "match.h"

 static LogLevel log_level = SYSLOG_LEVEL_INFO;
 static int log_on_stderr = 1;
 static int log_stderr_fd = STDERR_FILENO;
 static int log_facility = LOG_AUTH;
 static const char *argv0;
 static log_handler_fn *log_handler;
 static void *log_handler_ctx;
 static char **log_verbose;
 static size_t nlog_verbose;

 extern char *__progname;

 #define LOG_SYSLOG_VIS	(VIS_CSTYLE|VIS_NL|VIS_TAB|VIS_OCTAL)
 #define LOG_STDERR_VIS	(VIS_SAFE|VIS_OCTAL)

 /* textual representation of log-facilities/levels */

 static struct {
 	const char *name;
 	SyslogFacility val;
 } log_facilities[] = {
 	{ "DAEMON",	SYSLOG_FACILITY_DAEMON },
 	{ "USER",	SYSLOG_FACILITY_USER },
 	{ "AUTH",	SYSLOG_FACILITY_AUTH },
 #ifdef LOG_AUTHPRIV
 	{ "AUTHPRIV",	SYSLOG_FACILITY_AUTHPRIV },
 #endif
 	{ "LOCAL0",	SYSLOG_FACILITY_LOCAL0 },
 	{ "LOCAL1",	SYSLOG_FACILITY_LOCAL1 },
 	{ "LOCAL2",	SYSLOG_FACILITY_LOCAL2 },
 	{ "LOCAL3",	SYSLOG_FACILITY_LOCAL3 },
 	{ "LOCAL4",	SYSLOG_FACILITY_LOCAL4 },
 	{ "LOCAL5",	SYSLOG_FACILITY_LOCAL5 },
 	{ "LOCAL6",	SYSLOG_FACILITY_LOCAL6 },
 	{ "LOCAL7",	SYSLOG_FACILITY_LOCAL7 },
 	{ NULL,		SYSLOG_FACILITY_NOT_SET }
 };

 static struct {
 	const char *name;
 	LogLevel val;
 } log_levels[] =
 {
 	{ "QUIET",	SYSLOG_LEVEL_QUIET },
 	{ "FATAL",	SYSLOG_LEVEL_FATAL },
 	{ "ERROR",	SYSLOG_LEVEL_ERROR },
 	{ "INFO",	SYSLOG_LEVEL_INFO },
 	{ "VERBOSE",	SYSLOG_LEVEL_VERBOSE },
 	{ "DEBUG",	SYSLOG_LEVEL_DEBUG1 },
 	{ "DEBUG1",	SYSLOG_LEVEL_DEBUG1 },
 	{ "DEBUG2",	SYSLOG_LEVEL_DEBUG2 },
 	{ "DEBUG3",	SYSLOG_LEVEL_DEBUG3 },
 	{ NULL,		SYSLOG_LEVEL_NOT_SET }
 };

 LogLevel
 log_level_get(void)
 {
 	return log_level;
 }

 SyslogFacility
 log_facility_number(char *name)
 {
 	int i;

 	if (name != NULL)
 		for (i = 0; log_facilities[i].name; i++)
 			if (strcasecmp(log_facilities[i].name, name) == 0)
 				return log_facilities[i].val;
 	return SYSLOG_FACILITY_NOT_SET;
 }

 const char *
 log_facility_name(SyslogFacility facility)
 {
 	u_int i;

 	for (i = 0;  log_facilities[i].name; i++)
 		if (log_facilities[i].val == facility)
 			return log_facilities[i].name;
 	return NULL;
 }

 LogLevel
 log_level_number(char *name)
 {
 	int i;

 	if (name != NULL)
 		for (i = 0; log_levels[i].name; i++)
 			if (strcasecmp(log_levels[i].name, name) == 0)
 				return log_levels[i].val;
 	return SYSLOG_LEVEL_NOT_SET;
 }

 const char *
 log_level_name(LogLevel level)
 {
 	u_int i;

 	for (i = 0; log_levels[i].name != NULL; i++)
 		if (log_levels[i].val == level)
 			return log_levels[i].name;
 	return NULL;
 }

 void
 log_verbose_add(const char *s)
 {
 	char **tmp;

 	/* Ignore failures here */
 	if ((tmp = recallocarray(log_verbose, nlog_verbose, nlog_verbose + 1,
 	    sizeof(*log_verbose))) != NULL) {
 		log_verbose = tmp;
 		if ((log_verbose[nlog_verbose] = strdup(s)) != NULL)
 			nlog_verbose++;
 	}
 }

 void
 log_verbose_reset(void)
 {
 	size_t i;

 	for (i = 0; i < nlog_verbose; i++)
 		free(log_verbose[i]);
 	free(log_verbose);
 	log_verbose = NULL;
 	nlog_verbose = 0;
 }

 /*
  * Initialize the log.
  */

 void
 log_init(const char *av0, LogLevel level, SyslogFacility facility,
     int on_stderr)
 {
 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 	struct syslog_data sdata = SYSLOG_DATA_INIT;
 #endif

 	argv0 = av0;

 	if (log_change_level(level) != 0) {
 		fprintf(stderr, "Unrecognized internal syslog level code %d\n",
 		    (int) level);
 		exit(1);
 	}

 	log_handler = NULL;
 	log_handler_ctx = NULL;

 	log_on_stderr = on_stderr;
 	if (on_stderr)
 		return;

 	switch (facility) {
 	case SYSLOG_FACILITY_DAEMON:
 		log_facility = LOG_DAEMON;
 		break;
 	case SYSLOG_FACILITY_USER:
 		log_facility = LOG_USER;
 		break;
 	case SYSLOG_FACILITY_AUTH:
 		log_facility = LOG_AUTH;
 		break;
 #ifdef LOG_AUTHPRIV
 	case SYSLOG_FACILITY_AUTHPRIV:
 		log_facility = LOG_AUTHPRIV;
 		break;
 #endif
 	case SYSLOG_FACILITY_LOCAL0:
 		log_facility = LOG_LOCAL0;
 		break;
 	case SYSLOG_FACILITY_LOCAL1:
 		log_facility = LOG_LOCAL1;
 		break;
 	case SYSLOG_FACILITY_LOCAL2:
 		log_facility = LOG_LOCAL2;
 		break;
 	case SYSLOG_FACILITY_LOCAL3:
 		log_facility = LOG_LOCAL3;
 		break;
 	case SYSLOG_FACILITY_LOCAL4:
 		log_facility = LOG_LOCAL4;
 		break;
 	case SYSLOG_FACILITY_LOCAL5:
 		log_facility = LOG_LOCAL5;
 		break;
 	case SYSLOG_FACILITY_LOCAL6:
 		log_facility = LOG_LOCAL6;
 		break;
 	case SYSLOG_FACILITY_LOCAL7:
 		log_facility = LOG_LOCAL7;
 		break;
 	default:
 		fprintf(stderr,
 		    "Unrecognized internal syslog facility code %d\n",
 		    (int) facility);
 		exit(1);
 	}

 	/*
 	 * If an external library (eg libwrap) attempts to use syslog
 	 * immediately after reexec, syslog may be pointing to the wrong
 	 * facility, so we force an open/close of syslog here.
 	 */
 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 	openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
 	closelog_r(&sdata);
 #else
 	openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
 	closelog();
 #endif
 }

 int
 log_change_level(LogLevel new_log_level)
 {
 	/* no-op if log_init has not been called */
 	if (argv0 == NULL)
 		return 0;

 	switch (new_log_level) {
 	case SYSLOG_LEVEL_QUIET:
 	case SYSLOG_LEVEL_FATAL:
 	case SYSLOG_LEVEL_ERROR:
 	case SYSLOG_LEVEL_INFO:
 	case SYSLOG_LEVEL_VERBOSE:
 	case SYSLOG_LEVEL_DEBUG1:
 	case SYSLOG_LEVEL_DEBUG2:
 	case SYSLOG_LEVEL_DEBUG3:
 		log_level = new_log_level;
 		return 0;
 	default:
 		return -1;
 	}
 }

 int
 log_is_on_stderr(void)
 {
 	return log_on_stderr && log_stderr_fd == STDERR_FILENO;
 }

 /* redirect what would usually get written to stderr to specified file */
 void
 log_redirect_stderr_to(const char *logfile)
 {
 	int fd;

 	if (logfile == NULL) {
 		if (log_stderr_fd != STDERR_FILENO) {
 			close(log_stderr_fd);
 			log_stderr_fd = STDERR_FILENO;
 		}
 		return;
 	}

 	if ((fd = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0600)) == -1) {
 		fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
 		    strerror(errno));
 		exit(1);
 	}
 	log_stderr_fd = fd;
 }

 #define MSGBUFSIZ 1024

 void
 set_log_handler(log_handler_fn *handler, void *ctx)
 {
 	log_handler = handler;
 	log_handler_ctx = ctx;
 }

 static void
 do_log(LogLevel level, int force, const char *suffix, const char *fmt,
     va_list args)
 {
 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 	struct syslog_data sdata = SYSLOG_DATA_INIT;
 #endif
 	char msgbuf[MSGBUFSIZ];
 	char fmtbuf[MSGBUFSIZ];
 	char *txt = NULL;
 	int pri = LOG_INFO;
 	int saved_errno = errno;
 	log_handler_fn *tmp_handler;
 	const char *progname = argv0 != NULL ? argv0 : __progname;

 	if (!force && level > log_level)
 		return;

 	switch (level) {
 	case SYSLOG_LEVEL_FATAL:
 		if (!log_on_stderr)
 			txt = "fatal";
 		pri = LOG_CRIT;
 		break;
 	case SYSLOG_LEVEL_ERROR:
 		if (!log_on_stderr)
 			txt = "error";
 		pri = LOG_ERR;
 		break;
 	case SYSLOG_LEVEL_INFO:
 		pri = LOG_INFO;
 		break;
 	case SYSLOG_LEVEL_VERBOSE:
 		pri = LOG_INFO;
 		break;
 	case SYSLOG_LEVEL_DEBUG1:
 		txt = "debug1";
 		pri = LOG_DEBUG;
 		break;
 	case SYSLOG_LEVEL_DEBUG2:
 		txt = "debug2";
 		pri = LOG_DEBUG;
 		break;
 	case SYSLOG_LEVEL_DEBUG3:
 		txt = "debug3";
 		pri = LOG_DEBUG;
 		break;
 	default:
 		txt = "internal error";
 		pri = LOG_ERR;
 		break;
 	}
 	if (txt != NULL && log_handler == NULL) {
 		snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
 		vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
 	} else {
 		vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
 	}
 	if (suffix != NULL) {
 		snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", msgbuf, suffix);
 		strlcpy(msgbuf, fmtbuf, sizeof(msgbuf));
 	}
 	strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
 	    log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
 	if (log_handler != NULL) {
 		/* Avoid recursion */
 		tmp_handler = log_handler;
 		log_handler = NULL;
 		tmp_handler(level, force, fmtbuf, log_handler_ctx);
 		log_handler = tmp_handler;
 	} else if (log_on_stderr) {
 		snprintf(msgbuf, sizeof msgbuf, "%s%s%.*s\r\n",
 		    (log_on_stderr > 1) ? progname : "",
 		    (log_on_stderr > 1) ? ": " : "",
 		    (int)sizeof msgbuf - 3, fmtbuf);
 		(void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
 	} else {
 #if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
 		openlog_r(progname, LOG_PID, log_facility, &sdata);
 		syslog_r(pri, &sdata, "%.500s", fmtbuf);
 		closelog_r(&sdata);
 #else
 		openlog(progname, LOG_PID, log_facility);
 		syslog(pri, "%.500s", fmtbuf);
 		closelog();
 #endif
 	}
 	errno = saved_errno;
 }

 void
 sshlog(const char *file, const char *func, int line, int showfunc,
     LogLevel level, const char *suffix, const char *fmt, ...)
 {
 	va_list args;

 	va_start(args, fmt);
 	sshlogv(file, func, line, showfunc, level, suffix, fmt, args);
 	va_end(args);
 }

 void
 sshlogdie(const char *file, const char *func, int line, int showfunc,
     LogLevel level, const char *suffix, const char *fmt, ...)
 {
 	va_list args;

 	va_start(args, fmt);
 	sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_INFO,
 	    suffix, fmt, args);
 	va_end(args);
 	cleanup_exit(255);
 }

 void
 sshsigdie(const char *file, const char *func, int line, int showfunc,
     LogLevel level, const char *suffix, const char *fmt, ...)
 {
 	va_list args;

 	va_start(args, fmt);
 	sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_FATAL,
 	    suffix, fmt, args);
 	va_end(args);
 	_exit(1);
 }

 void
 sshlogv(const char *file, const char *func, int line, int showfunc,
     LogLevel level, const char *suffix, const char *fmt, va_list args)
 {
 	char tag[128], fmt2[MSGBUFSIZ + 128];
 	int forced = 0;
 	const char *cp;
 	size_t i;

 	snprintf(tag, sizeof(tag), "%.48s:%.48s():%d (pid=%ld)",
 	    (cp = strrchr(file, '/')) == NULL ? file : cp + 1, func, line,
 	    (long)getpid());
 	for (i = 0; i < nlog_verbose; i++) {
 		if (match_pattern_list(tag, log_verbose[i], 0) == 1) {
 			forced = 1;
 			break;
 		}
 	}

 	if (forced)
 		snprintf(fmt2, sizeof(fmt2), "%s: %s", tag, fmt);
 	else if (showfunc)
 		snprintf(fmt2, sizeof(fmt2), "%s: %s", func, fmt);
 	else
 		strlcpy(fmt2, fmt, sizeof(fmt2));

 	do_log(level, forced, suffix, fmt2, args);
 }

 void
 sshlogdirect(LogLevel level, int forced, const char *fmt, ...)
 {
 	va_list args;

 	va_start(args, fmt);
 	do_log(level, forced, NULL, fmt, args);
 	va_end(args);
 }
	/* $OpenBSD: log.c,v 1.60 2021/09/16 15:11:19 djm Exp $ */
	/*
	* Author: Tatu Ylonen <[email protected]>
	* Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
	* All rights reserved
	*
	* As far as I am concerned, the code I have written for this software
	* can be used freely for any purpose. Any derived versions of this
	* software must be clearly marked as such, and if the derived work is
	* incompatible with the protocol description in the RFC file, it must be
	* called by a name other than "ssh" or "Secure Shell".
	*/
	/*
	* Copyright (c) 2000 Markus Friedl. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "includes.h"

	#include <sys/types.h>

	#include <fcntl.h>
	#include <stdarg.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <syslog.h>
	#include <unistd.h>
	#include <errno.h>
	#if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
	# include <vis.h>
	#endif

	#include "log.h"
	#include "match.h"

	static LogLevel log_level = SYSLOG_LEVEL_INFO;
	static int log_on_stderr = 1;
	static int log_stderr_fd = STDERR_FILENO;
	static int log_facility = LOG_AUTH;
	static const char *argv0;
	static log_handler_fn *log_handler;
	static void *log_handler_ctx;
	static char **log_verbose;
	static size_t nlog_verbose;

	extern char *__progname;

	#define LOG_SYSLOG_VIS (VIS_CSTYLE\|VIS_NL\|VIS_TAB\|VIS_OCTAL)
	#define LOG_STDERR_VIS (VIS_SAFE\|VIS_OCTAL)

	/* textual representation of log-facilities/levels */

	static struct {
	const char *name;
	SyslogFacility val;
	} log_facilities[] = {
	{ "DAEMON", SYSLOG_FACILITY_DAEMON },
	{ "USER", SYSLOG_FACILITY_USER },
	{ "AUTH", SYSLOG_FACILITY_AUTH },
	#ifdef LOG_AUTHPRIV
	{ "AUTHPRIV", SYSLOG_FACILITY_AUTHPRIV },
	#endif
	{ "LOCAL0", SYSLOG_FACILITY_LOCAL0 },
	{ "LOCAL1", SYSLOG_FACILITY_LOCAL1 },
	{ "LOCAL2", SYSLOG_FACILITY_LOCAL2 },
	{ "LOCAL3", SYSLOG_FACILITY_LOCAL3 },
	{ "LOCAL4", SYSLOG_FACILITY_LOCAL4 },
	{ "LOCAL5", SYSLOG_FACILITY_LOCAL5 },
	{ "LOCAL6", SYSLOG_FACILITY_LOCAL6 },
	{ "LOCAL7", SYSLOG_FACILITY_LOCAL7 },
	{ NULL, SYSLOG_FACILITY_NOT_SET }
	};

	static struct {
	const char *name;
	LogLevel val;
	} log_levels[] =
	{
	{ "QUIET", SYSLOG_LEVEL_QUIET },
	{ "FATAL", SYSLOG_LEVEL_FATAL },
	{ "ERROR", SYSLOG_LEVEL_ERROR },
	{ "INFO", SYSLOG_LEVEL_INFO },
	{ "VERBOSE", SYSLOG_LEVEL_VERBOSE },
	{ "DEBUG", SYSLOG_LEVEL_DEBUG1 },
	{ "DEBUG1", SYSLOG_LEVEL_DEBUG1 },
	{ "DEBUG2", SYSLOG_LEVEL_DEBUG2 },
	{ "DEBUG3", SYSLOG_LEVEL_DEBUG3 },
	{ NULL, SYSLOG_LEVEL_NOT_SET }
	};

	LogLevel
	log_level_get(void)
	{
	return log_level;
	}

	SyslogFacility
	log_facility_number(char *name)
	{
	int i;

	if (name != NULL)
	for (i = 0; log_facilities[i].name; i++)
	if (strcasecmp(log_facilities[i].name, name) == 0)
	return log_facilities[i].val;
	return SYSLOG_FACILITY_NOT_SET;
	}

	const char *
	log_facility_name(SyslogFacility facility)
	{
	u_int i;

	for (i = 0; log_facilities[i].name; i++)
	if (log_facilities[i].val == facility)
	return log_facilities[i].name;
	return NULL;
	}

	LogLevel
	log_level_number(char *name)
	{
	int i;

	if (name != NULL)
	for (i = 0; log_levels[i].name; i++)
	if (strcasecmp(log_levels[i].name, name) == 0)
	return log_levels[i].val;
	return SYSLOG_LEVEL_NOT_SET;
	}

	const char *
	log_level_name(LogLevel level)
	{
	u_int i;

	for (i = 0; log_levels[i].name != NULL; i++)
	if (log_levels[i].val == level)
	return log_levels[i].name;
	return NULL;
	}

	void
	log_verbose_add(const char *s)
	{
	char **tmp;

	/* Ignore failures here */
	if ((tmp = recallocarray(log_verbose, nlog_verbose, nlog_verbose + 1,
	sizeof(*log_verbose))) != NULL) {
	log_verbose = tmp;
	if ((log_verbose[nlog_verbose] = strdup(s)) != NULL)
	nlog_verbose++;
	}
	}

	void
	log_verbose_reset(void)
	{
	size_t i;

	for (i = 0; i < nlog_verbose; i++)
	free(log_verbose[i]);
	free(log_verbose);
	log_verbose = NULL;
	nlog_verbose = 0;
	}

	/*
	* Initialize the log.
	*/

	void
	log_init(const char *av0, LogLevel level, SyslogFacility facility,
	int on_stderr)
	{
	#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
	struct syslog_data sdata = SYSLOG_DATA_INIT;
	#endif

	argv0 = av0;

	if (log_change_level(level) != 0) {
	fprintf(stderr, "Unrecognized internal syslog level code %d\n",
	(int) level);
	exit(1);
	}

	log_handler = NULL;
	log_handler_ctx = NULL;

	log_on_stderr = on_stderr;
	if (on_stderr)
	return;

	switch (facility) {
	case SYSLOG_FACILITY_DAEMON:
	log_facility = LOG_DAEMON;
	break;
	case SYSLOG_FACILITY_USER:
	log_facility = LOG_USER;
	break;
	case SYSLOG_FACILITY_AUTH:
	log_facility = LOG_AUTH;
	break;
	#ifdef LOG_AUTHPRIV
	case SYSLOG_FACILITY_AUTHPRIV:
	log_facility = LOG_AUTHPRIV;
	break;
	#endif
	case SYSLOG_FACILITY_LOCAL0:
	log_facility = LOG_LOCAL0;
	break;
	case SYSLOG_FACILITY_LOCAL1:
	log_facility = LOG_LOCAL1;
	break;
	case SYSLOG_FACILITY_LOCAL2:
	log_facility = LOG_LOCAL2;
	break;
	case SYSLOG_FACILITY_LOCAL3:
	log_facility = LOG_LOCAL3;
	break;
	case SYSLOG_FACILITY_LOCAL4:
	log_facility = LOG_LOCAL4;
	break;
	case SYSLOG_FACILITY_LOCAL5:
	log_facility = LOG_LOCAL5;
	break;
	case SYSLOG_FACILITY_LOCAL6:
	log_facility = LOG_LOCAL6;
	break;
	case SYSLOG_FACILITY_LOCAL7:
	log_facility = LOG_LOCAL7;
	break;
	default:
	fprintf(stderr,
	"Unrecognized internal syslog facility code %d\n",
	(int) facility);
	exit(1);
	}

	/*
	* If an external library (eg libwrap) attempts to use syslog
	* immediately after reexec, syslog may be pointing to the wrong
	* facility, so we force an open/close of syslog here.
	*/
	#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
	openlog_r(argv0 ? argv0 : __progname, LOG_PID, log_facility, &sdata);
	closelog_r(&sdata);
	#else
	openlog(argv0 ? argv0 : __progname, LOG_PID, log_facility);
	closelog();
	#endif
	}

	int
	log_change_level(LogLevel new_log_level)
	{
	/* no-op if log_init has not been called */
	if (argv0 == NULL)
	return 0;

	switch (new_log_level) {
	case SYSLOG_LEVEL_QUIET:
	case SYSLOG_LEVEL_FATAL:
	case SYSLOG_LEVEL_ERROR:
	case SYSLOG_LEVEL_INFO:
	case SYSLOG_LEVEL_VERBOSE:
	case SYSLOG_LEVEL_DEBUG1:
	case SYSLOG_LEVEL_DEBUG2:
	case SYSLOG_LEVEL_DEBUG3:
	log_level = new_log_level;
	return 0;
	default:
	return -1;
	}
	}

	int
	log_is_on_stderr(void)
	{
	return log_on_stderr && log_stderr_fd == STDERR_FILENO;
	}

	/* redirect what would usually get written to stderr to specified file */
	void
	log_redirect_stderr_to(const char *logfile)
	{
	int fd;

	if (logfile == NULL) {
	if (log_stderr_fd != STDERR_FILENO) {
	close(log_stderr_fd);
	log_stderr_fd = STDERR_FILENO;
	}
	return;
	}

	if ((fd = open(logfile, O_WRONLY\|O_CREAT\|O_APPEND, 0600)) == -1) {
	fprintf(stderr, "Couldn't open logfile %s: %s\n", logfile,
	strerror(errno));
	exit(1);
	}
	log_stderr_fd = fd;
	}

	#define MSGBUFSIZ 1024

	void
	set_log_handler(log_handler_fn handler, void ctx)
	{
	log_handler = handler;
	log_handler_ctx = ctx;
	}

	static void
	do_log(LogLevel level, int force, const char suffix, const char fmt,
	va_list args)
	{
	#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
	struct syslog_data sdata = SYSLOG_DATA_INIT;
	#endif
	char msgbuf[MSGBUFSIZ];
	char fmtbuf[MSGBUFSIZ];
	char *txt = NULL;
	int pri = LOG_INFO;
	int saved_errno = errno;
	log_handler_fn *tmp_handler;
	const char *progname = argv0 != NULL ? argv0 : __progname;

	if (!force && level > log_level)
	return;

	switch (level) {
	case SYSLOG_LEVEL_FATAL:
	if (!log_on_stderr)
	txt = "fatal";
	pri = LOG_CRIT;
	break;
	case SYSLOG_LEVEL_ERROR:
	if (!log_on_stderr)
	txt = "error";
	pri = LOG_ERR;
	break;
	case SYSLOG_LEVEL_INFO:
	pri = LOG_INFO;
	break;
	case SYSLOG_LEVEL_VERBOSE:
	pri = LOG_INFO;
	break;
	case SYSLOG_LEVEL_DEBUG1:
	txt = "debug1";
	pri = LOG_DEBUG;
	break;
	case SYSLOG_LEVEL_DEBUG2:
	txt = "debug2";
	pri = LOG_DEBUG;
	break;
	case SYSLOG_LEVEL_DEBUG3:
	txt = "debug3";
	pri = LOG_DEBUG;
	break;
	default:
	txt = "internal error";
	pri = LOG_ERR;
	break;
	}
	if (txt != NULL && log_handler == NULL) {
	snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", txt, fmt);
	vsnprintf(msgbuf, sizeof(msgbuf), fmtbuf, args);
	} else {
	vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
	}
	if (suffix != NULL) {
	snprintf(fmtbuf, sizeof(fmtbuf), "%s: %s", msgbuf, suffix);
	strlcpy(msgbuf, fmtbuf, sizeof(msgbuf));
	}
	strnvis(fmtbuf, msgbuf, sizeof(fmtbuf),
	log_on_stderr ? LOG_STDERR_VIS : LOG_SYSLOG_VIS);
	if (log_handler != NULL) {
	/* Avoid recursion */
	tmp_handler = log_handler;
	log_handler = NULL;
	tmp_handler(level, force, fmtbuf, log_handler_ctx);
	log_handler = tmp_handler;
	} else if (log_on_stderr) {
	snprintf(msgbuf, sizeof msgbuf, "%s%s%.*s\r\n",
	(log_on_stderr > 1) ? progname : "",
	(log_on_stderr > 1) ? ": " : "",
	(int)sizeof msgbuf - 3, fmtbuf);
	(void)write(log_stderr_fd, msgbuf, strlen(msgbuf));
	} else {
	#if defined(HAVE_OPENLOG_R) && defined(SYSLOG_DATA_INIT)
	openlog_r(progname, LOG_PID, log_facility, &sdata);
	syslog_r(pri, &sdata, "%.500s", fmtbuf);
	closelog_r(&sdata);
	#else
	openlog(progname, LOG_PID, log_facility);
	syslog(pri, "%.500s", fmtbuf);
	closelog();
	#endif
	}
	errno = saved_errno;
	}

	void
	sshlog(const char file, const char func, int line, int showfunc,
	LogLevel level, const char suffix, const char fmt, ...)
	{
	va_list args;

	va_start(args, fmt);
	sshlogv(file, func, line, showfunc, level, suffix, fmt, args);
	va_end(args);
	}

	void
	sshlogdie(const char file, const char func, int line, int showfunc,
	LogLevel level, const char suffix, const char fmt, ...)
	{
	va_list args;

	va_start(args, fmt);
	sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_INFO,
	suffix, fmt, args);
	va_end(args);
	cleanup_exit(255);
	}

	void
	sshsigdie(const char file, const char func, int line, int showfunc,
	LogLevel level, const char suffix, const char fmt, ...)
	{
	va_list args;

	va_start(args, fmt);
	sshlogv(file, func, line, showfunc, SYSLOG_LEVEL_FATAL,
	suffix, fmt, args);
	va_end(args);
	_exit(1);
	}

	void
	sshlogv(const char file, const char func, int line, int showfunc,
	LogLevel level, const char suffix, const char fmt, va_list args)
	{
	char tag[128], fmt2[MSGBUFSIZ + 128];
	int forced = 0;
	const char *cp;
	size_t i;

	snprintf(tag, sizeof(tag), "%.48s:%.48s():%d (pid=%ld)",
	(cp = strrchr(file, '/')) == NULL ? file : cp + 1, func, line,
	(long)getpid());
	for (i = 0; i < nlog_verbose; i++) {
	if (match_pattern_list(tag, log_verbose[i], 0) == 1) {
	forced = 1;
	break;
	}
	}

	if (forced)
	snprintf(fmt2, sizeof(fmt2), "%s: %s", tag, fmt);
	else if (showfunc)
	snprintf(fmt2, sizeof(fmt2), "%s: %s", func, fmt);
	else
	strlcpy(fmt2, fmt, sizeof(fmt2));

	do_log(level, forced, suffix, fmt2, args);
	}

	void
	sshlogdirect(LogLevel level, int forced, const char *fmt, ...)
	{
	va_list args;

	va_start(args, fmt);
	do_log(level, forced, NULL, fmt, args);
	va_end(args);
	}