log.c

bind 9.3结合mysql数据库

/*
 * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: log.c,v 1.70.2.8.2.12 2004/06/11 00:35:38 marka Exp $ */

/* Principal Authors: DCL */

#include <config.h>

#include <errno.h>
#include <stdlib.h>
#include <limits.h>
#include <time.h>

#include <sys/types.h>	/* dev_t FreeBSD 2.1 */

#include <isc/dir.h>
#include <isc/file.h>
#include <isc/log.h>
#include <isc/magic.h>
#include <isc/mem.h>
#include <isc/msgs.h>
#include <isc/print.h>
#include <isc/stat.h>
#include <isc/stdio.h>
#include <isc/string.h>
#include <isc/time.h>
#include <isc/util.h>

#define LCTX_MAGIC		ISC_MAGIC('L', 'c', 't', 'x')
#define VALID_CONTEXT(lctx)	ISC_MAGIC_VALID(lctx, LCTX_MAGIC)

#define LCFG_MAGIC		ISC_MAGIC('L', 'c', 'f', 'g')
#define VALID_CONFIG(lcfg)	ISC_MAGIC_VALID(lcfg, LCFG_MAGIC)

/*
 * XXXDCL make dynamic?
 */
#define LOG_BUFFER_SIZE	(8 * 1024)

#ifndef PATH_MAX
#define PATH_MAX 1024	/* AIX and others don't define this. */
#endif

/*
 * This is the structure that holds each named channel.  A simple linked
 * list chains all of the channels together, so an individual channel is
 * found by doing strcmp()s with the names down the list.  Their should
 * be no peformance penalty from this as it is expected that the number
 * of named channels will be no more than a dozen or so, and name lookups
 * from the head of the list are only done when isc_log_usechannel() is
 * called, which should also be very infrequent.
 */
typedef struct isc_logchannel isc_logchannel_t;

struct isc_logchannel {
	char *				name;
	unsigned int			type;
	int 				level;
	unsigned int			flags;
	isc_logdestination_t 		destination;
	ISC_LINK(isc_logchannel_t)	link;
};

/*
 * The logchannellist structure associates categories and modules with
 * channels.  First the appropriate channellist is found based on the
 * category, and then each structure in the linked list is checked for
 * a matching module.  It is expected that the number of channels
 * associated with any given category will be very short, no more than
 * three or four in the more unusual cases.
 */
typedef struct isc_logchannellist isc_logchannellist_t;

struct isc_logchannellist {
	const isc_logmodule_t *		module;
	isc_logchannel_t *		channel;
	ISC_LINK(isc_logchannellist_t)	link;
};

/*
 * This structure is used to remember messages for pruning via
 * isc_log_[v]write1().
 */
typedef struct isc_logmessage isc_logmessage_t;

struct isc_logmessage {
	char *				text;
	isc_time_t			time;
	ISC_LINK(isc_logmessage_t)	link;
};

/*
 * The isc_logconfig structure is used to store the configurable information
 * about where messages are actually supposed to be sent -- the information
 * that could changed based on some configuration file, as opposed to the
 * the category/module specification of isc_log_[v]write[1] that is compiled
 * into a program, or the debug_level which is dynamic state information.
 */
struct isc_logconfig {
	unsigned int			magic;
	isc_log_t *			lctx;
	ISC_LIST(isc_logchannel_t)	channels;
	ISC_LIST(isc_logchannellist_t) *channellists;
	unsigned int			channellist_count;
	unsigned int			duplicate_interval;
	int				highest_level;
	char *				tag;
	isc_boolean_t			dynamic;
};

/*
 * This isc_log structure provides the context for the isc_log functions.
 * The log context locks itself in isc_log_doit, the internal backend to
 * isc_log_write.  The locking is necessary both to provide exclusive access
 * to the the buffer into which the message is formatted and to guard against
 * competing threads trying to write to the same syslog resource.  (On
 * some systems, such as BSD/OS, stdio is thread safe but syslog is not.)
 * Unfortunately, the lock cannot guard against a _different_ logging
 * context in the same program competing for syslog's attention.  Thus
 * There Can Be Only One, but this is not enforced.
 * XXXDCL enforce it?
 *
 * Note that the category and module information is not locked.
 * This is because in the usual case, only one isc_log_t is ever created
 * in a program, and the category/module registration happens only once.
 * XXXDCL it might be wise to add more locking overall.
 */
struct isc_log {
	/* Not locked. */
	unsigned int			magic;
	isc_mem_t *			mctx;
	isc_logcategory_t *		categories;
	unsigned int			category_count;
	isc_logmodule_t *		modules;
	unsigned int			module_count;
	int				debug_level;
	isc_mutex_t			lock;
	/* Locked by isc_log lock. */
	isc_logconfig_t * 		logconfig;
	char 				buffer[LOG_BUFFER_SIZE];
	ISC_LIST(isc_logmessage_t)	messages;
};

/*
 * Used when ISC_LOG_PRINTLEVEL is enabled for a channel.
 */
static const char *log_level_strings[] = {
	"debug",
	"info",
	"notice",
	"warning",
	"error",
	"critical"
};

/*
 * Used to convert ISC_LOG_* priorities into syslog priorities.
 * XXXDCL This will need modification for NT.
 */
static const int syslog_map[] = {
	LOG_DEBUG,
	LOG_INFO,
	LOG_NOTICE,
	LOG_WARNING,
	LOG_ERR,
	LOG_CRIT
};

/*
 * When adding new categories, a corresponding ISC_LOGCATEGORY_foo
 * definition needs to be added to <isc/log.h>.
 *
 * The default category is provided so that the internal default can
 * be overridden.  Since the default is always looked up as the first
 * channellist in the log context, it must come first in isc_categories[].
 */
LIBISC_EXTERNAL_DATA isc_logcategory_t isc_categories[] = {
	{ "default", 0 },	/* "default" must come first. */
	{ "general", 0 },
	{ NULL, 0 }
};

/*
 * See above comment for categories, and apply it to modules.
 */
LIBISC_EXTERNAL_DATA isc_logmodule_t isc_modules[] = {
	{ "socket", 0 },
	{ "time", 0 },
	{ "interface", 0 },
	{ "timer", 0 },
	{ NULL, 0 }
};

/*
 * This essentially constant structure must be filled in at run time,
 * because its channel member is pointed to a channel that is created
 * dynamically with isc_log_createchannel.
 */
static isc_logchannellist_t default_channel;

/*
 * libisc logs to this context.
 */
LIBISC_EXTERNAL_DATA isc_log_t *isc_lctx = NULL;

/*
 * Forward declarations.
 */
static isc_result_t
assignchannel(isc_logconfig_t *lcfg, unsigned int category_id,
	      const isc_logmodule_t *module, isc_logchannel_t *channel);

static isc_result_t
sync_channellist(isc_logconfig_t *lcfg);

static isc_result_t
greatest_version(isc_logchannel_t *channel, int *greatest);

static isc_result_t
roll_log(isc_logchannel_t *channel);

static void
isc_log_doit(isc_log_t *lctx, isc_logcategory_t *category,
	     isc_logmodule_t *module, int level, isc_boolean_t write_once,
	     isc_msgcat_t *msgcat, int msgset, int msg,
	     const char *format, va_list args)
     ISC_FORMAT_PRINTF(9, 0);

/*
 * Convenience macros.
 */

#define FACILITY(channel)	 (channel->destination.facility)
#define FILE_NAME(channel)	 (channel->destination.file.name)
#define FILE_STREAM(channel)	 (channel->destination.file.stream)
#define FILE_VERSIONS(channel)	 (channel->destination.file.versions)
#define FILE_MAXSIZE(channel)	 (channel->destination.file.maximum_size)
#define FILE_MAXREACHED(channel) (channel->destination.file.maximum_reached)

/****
 **** Public interfaces.
 ****/

/*
 * Establish a new logging context, with default channels.
 */
isc_result_t
isc_log_create(isc_mem_t *mctx, isc_log_t **lctxp, isc_logconfig_t **lcfgp) {
	isc_log_t *lctx;
	isc_logconfig_t *lcfg = NULL;
	isc_result_t result;

	REQUIRE(mctx != NULL);
	REQUIRE(lctxp != NULL && *lctxp == NULL);
	REQUIRE(lcfgp == NULL || *lcfgp == NULL);

	lctx = isc_mem_get(mctx, sizeof(*lctx));
	if (lctx != NULL) {
		lctx->mctx = mctx;
		lctx->categories = NULL;
		lctx->category_count = 0;
		lctx->modules = NULL;
		lctx->module_count = 0;
		lctx->debug_level = 0;

		ISC_LIST_INIT(lctx->messages);

		RUNTIME_CHECK(isc_mutex_init(&lctx->lock) == ISC_R_SUCCESS);

		/*
		 * Normally setting the magic number is the last step done
		 * in a creation function, but a valid log context is needed
		 * by isc_log_registercategories and isc_logconfig_create.
		 * If either fails, the lctx is destroyed and not returned
		 * to the caller.
		 */
		lctx->magic = LCTX_MAGIC;

		isc_log_registercategories(lctx, isc_categories);
		isc_log_registermodules(lctx, isc_modules);
		result = isc_logconfig_create(lctx, &lcfg);

	} else
		result = ISC_R_NOMEMORY;

	if (result == ISC_R_SUCCESS)
		result = sync_channellist(lcfg);

	if (result == ISC_R_SUCCESS) {
		lctx->logconfig = lcfg;

		*lctxp = lctx;
		if (lcfgp != NULL)
			*lcfgp = lcfg;

	} else {
		if (lcfg != NULL)
			isc_logconfig_destroy(&lcfg);
		if (lctx != NULL)
			isc_log_destroy(&lctx);
	}

	return (result);
}

isc_result_t
isc_logconfig_create(isc_log_t *lctx, isc_logconfig_t **lcfgp) {
	isc_logconfig_t *lcfg;
	isc_logdestination_t destination;
	isc_result_t result = ISC_R_SUCCESS;
	int level = ISC_LOG_INFO;

	REQUIRE(lcfgp != NULL && *lcfgp == NULL);
	REQUIRE(VALID_CONTEXT(lctx));

	lcfg = isc_mem_get(lctx->mctx, sizeof(*lcfg));

	if (lcfg != NULL) {
		lcfg->lctx = lctx;
		lcfg->channellists = NULL;
		lcfg->channellist_count = 0;
		lcfg->duplicate_interval = 0;
		lcfg->highest_level = level;
		lcfg->tag = NULL;
		lcfg->dynamic = ISC_FALSE;

		ISC_LIST_INIT(lcfg->channels);

		/*
		 * Normally the magic number is the last thing set in the
		 * structure, but isc_log_createchannel() needs a valid
		 * config.  If the channel creation fails, the lcfg is not
		 * returned to the caller.
		 */
		lcfg->magic = LCFG_MAGIC;

	} else
		result = ISC_R_NOMEMORY;

	/*
	 * Create the default channels:
	 *   	default_syslog, default_stderr, default_debug and null.
	 */
	if (result == ISC_R_SUCCESS) {
		destination.facility = LOG_DAEMON;
		result = isc_log_createchannel(lcfg, "default_syslog",
					       ISC_LOG_TOSYSLOG, level,
					       &destination, 0);
	}

	if (result == ISC_R_SUCCESS) {
		destination.file.stream = stderr;
		destination.file.name = NULL;
		destination.file.versions = ISC_LOG_ROLLNEVER;
		destination.file.maximum_size = 0;
		result = isc_log_createchannel(lcfg, "default_stderr",
					       ISC_LOG_TOFILEDESC,
					       level,
					       &destination,
					       ISC_LOG_PRINTTIME);
	}

	if (result == ISC_R_SUCCESS) {
		/*
		 * Set the default category's channel to default_stderr,
		 * which is at the head of the channels list because it was
		 * just created.
		 */
		default_channel.channel = ISC_LIST_HEAD(lcfg->channels);

		destination.file.stream = stderr;
		destination.file.name = NULL;
		destination.file.versions = ISC_LOG_ROLLNEVER;
		destination.file.maximum_size = 0;
		result = isc_log_createchannel(lcfg, "default_debug",
					       ISC_LOG_TOFILEDESC,
					       ISC_LOG_DYNAMIC,
					       &destination,
					       ISC_LOG_PRINTTIME);
	}

	if (result == ISC_R_SUCCESS)
		result = isc_log_createchannel(lcfg, "null",
					       ISC_LOG_TONULL,
					       ISC_LOG_DYNAMIC,
					       NULL, 0);

	if (result == ISC_R_SUCCESS)
		*lcfgp = lcfg;

	else
		if (lcfg != NULL)
			isc_logconfig_destroy(&lcfg);

	return (result);
}

isc_logconfig_t *
isc_logconfig_get(isc_log_t *lctx) {
	REQUIRE(VALID_CONTEXT(lctx));

	ENSURE(lctx->logconfig != NULL);

	return (lctx->logconfig);
}

isc_result_t
isc_logconfig_use(isc_log_t *lctx, isc_logconfig_t *lcfg) {
	isc_logconfig_t *old_cfg;
	isc_result_t result;

	REQUIRE(VALID_CONTEXT(lctx));
	REQUIRE(VALID_CONFIG(lcfg));
	REQUIRE(lcfg->lctx == lctx);

	/*
	 * Ensure that lcfg->channellist_count == lctx->category_count.
	 * They won't be equal if isc_log_usechannel has not been called
	 * since any call to isc_log_registercategories.
	 */
	result = sync_channellist(lcfg);
	if (result != ISC_R_SUCCESS)
		return (result);

	LOCK(&lctx->lock);

	old_cfg = lctx->logconfig;
	lctx->logconfig = lcfg;

	UNLOCK(&lctx->lock);

	isc_logconfig_destroy(&old_cfg);

	return (ISC_R_SUCCESS);
}

void
isc_log_destroy(isc_log_t **lctxp) {
	isc_log_t *lctx;
	isc_logconfig_t *lcfg;
	isc_mem_t *mctx;
	isc_logmessage_t *message;

	REQUIRE(lctxp != NULL && VALID_CONTEXT(*lctxp));

	lctx = *lctxp;
	mctx = lctx->mctx;

	if (lctx->logconfig != NULL) {
		lcfg = lctx->logconfig;
		lctx->logconfig = NULL;
		isc_logconfig_destroy(&lcfg);
	}

	DESTROYLOCK(&lctx->lock);

	while ((message = ISC_LIST_HEAD(lctx->messages)) != NULL) {
		ISC_LIST_UNLINK(lctx->messages, message, link);

		isc_mem_put(mctx, message,
			    sizeof(*message) + strlen(message->text) + 1);
	}

	lctx->buffer[0] = '\0';
	lctx->debug_level = 0;
	lctx->categories = NULL;
	lctx->category_count = 0;
	lctx->modules = NULL;
	lctx->module_count = 0;
	lctx->mctx = NULL;
	lctx->magic = 0;

	isc_mem_put(mctx, lctx, sizeof(*lctx));

	*lctxp = NULL;
}

void
isc_logconfig_destroy(isc_logconfig_t **lcfgp) {
	isc_logconfig_t *lcfg;
	isc_mem_t *mctx;
	isc_logchannel_t *channel;
	isc_logchannellist_t *item;
	char *filename;
	unsigned int i;

	REQUIRE(lcfgp != NULL && VALID_CONFIG(*lcfgp));

	lcfg = *lcfgp;

	/*
	 * This function cannot be called with a logconfig that is in
	 * use by a log context.
	 */
	REQUIRE(lcfg->lctx != NULL && lcfg->lctx->logconfig != lcfg);

	mctx = lcfg->lctx->mctx;

	while ((channel = ISC_LIST_HEAD(lcfg->channels)) != NULL) {
		ISC_LIST_UNLINK(lcfg->channels, channel, link);

		if (channel->type == ISC_LOG_TOFILE) {
			/*
			 * The filename for the channel may have ultimately
			 * started its life in user-land as a const string,
			 * but in isc_log_createchannel it gets copied
			 * into writable memory and is not longer truly const.
			 */
			DE_CONST(FILE_NAME(channel), filename);
			isc_mem_free(mctx, filename);

			if (FILE_STREAM(channel) != NULL)
				(void)fclose(FILE_STREAM(channel));
		}

		isc_mem_free(mctx, channel->name);
		isc_mem_put(mctx, channel, sizeof(*channel));
	}

	for (i = 0; i < lcfg->channellist_count; i++)
		while ((item = ISC_LIST_HEAD(lcfg->channellists[i])) != NULL) {
			ISC_LIST_UNLINK(lcfg->channellists[i], item, link);
			isc_mem_put(mctx, item, sizeof(*item));
		}

	if (lcfg->channellist_count > 0)
		isc_mem_put(mctx, lcfg->channellists,
			    lcfg->channellist_count *
			    sizeof(ISC_LIST(isc_logchannellist_t)));

	lcfg->dynamic = ISC_FALSE;
	if (lcfg->tag != NULL)
		isc_mem_free(lcfg->lctx->mctx, lcfg->tag);
	lcfg->tag = NULL;
	lcfg->highest_level = 0;
	lcfg->duplicate_interval = 0;
	lcfg->magic = 0;

	isc_mem_put(mctx, lcfg, sizeof(*lcfg));

	*lcfgp = NULL;
}

void
isc_log_registercategories(isc_log_t *lctx, isc_logcategory_t categories[]) {
	isc_logcategory_t *catp;

	REQUIRE(VALID_CONTEXT(lctx));
	REQUIRE(categories != NULL && categories[0].name != NULL);

	/*
	 * XXXDCL This somewhat sleazy situation of using the last pointer
	 * in one category array to point to the next array exists because
	 * this registration function returns void and I didn't want to have
	 * change everything that used it by making it return an isc_result_t.
	 * It would need to do that if it had to allocate memory to store
	 * pointers to each array passed in.
	 */
	if (lctx->categories == NULL)
		lctx->categories = categories;

	else {
		/*
		 * Adjust the last (NULL) pointer of the already registered
		 * categories to point to the incoming array.
		 */
		for (catp = lctx->categories; catp->name != NULL; )
			if (catp->id == UINT_MAX)
				/*
				 * The name pointer points to the next array.