log.c

bind 9.3结合mysql数据库

	isc_dir_init(&dir);
	result = isc_dir_open(&dir, dirname);

	/*
	 * Replace the file separator if it was taken out.
	 */
	if (basename != FILE_NAME(channel))
		*(basename - 1) = sep;

	/*
	 * Return if the directory open failed.
	 */
	if (result != ISC_R_SUCCESS)
		return (result);

	while (isc_dir_read(&dir) == ISC_R_SUCCESS) {
		if (dir.entry.length > basenamelen &&
		    strncmp(dir.entry.name, basename, basenamelen) == 0 &&
		    dir.entry.name[basenamelen] == '.') {

			version = strtol(&dir.entry.name[basenamelen + 1],
					 &digit_end, 10);
			if (*digit_end == '\0' && version > greatest)
				greatest = version;
		}
	}
	isc_dir_close(&dir);

	*greatestp = ++greatest;

	return (ISC_R_SUCCESS);
}

static isc_result_t
roll_log(isc_logchannel_t *channel) {
	int i, n, greatest;
	char current[PATH_MAX + 1];
	char new[PATH_MAX + 1];
	const char *path;
	isc_result_t result;

	/*
	 * Do nothing (not even excess version trimming) if ISC_LOG_ROLLNEVER
	 * is specified.  Apparently complete external control over the log
	 * files is desired.
	 */
	if (FILE_VERSIONS(channel) == ISC_LOG_ROLLNEVER)
		return (ISC_R_SUCCESS);

	path = FILE_NAME(channel);

	/*
	 * Set greatest_version to the greatest existing version
	 * (not the maximum requested version).  This is 1 based even
	 * though the file names are 0 based, so an oldest log of log.1
	 * is a greatest_version of 2.
	 */
	result = greatest_version(channel, &greatest);
	if (result != ISC_R_SUCCESS)
		return (result);

	/*
	 * Now greatest should be set to the highest version number desired.
	 * Since the highest number is one less than FILE_VERSIONS(channel)
	 * when not doing infinite log rolling, greatest will need to be
	 * decremented when it is equal to -- or greater than --
	 * FILE_VERSIONS(channel).  When greatest is less than
	 * FILE_VERSIONS(channel), it is already suitable for use as
	 * the maximum version number.
	 */

	if (FILE_VERSIONS(channel) == ISC_LOG_ROLLINFINITE ||
	    FILE_VERSIONS(channel) > greatest)
		;		/* Do nothing. */
	else
		/*
		 * When greatest is >= FILE_VERSIONS(channel), it needs to
		 * be reduced until it is FILE_VERSIONS(channel) - 1.
		 * Remove any excess logs on the way to that value.
		 */
		while (--greatest >= FILE_VERSIONS(channel)) {
			n = snprintf(current, sizeof(current), "%s.%d",
				     path, greatest);
			if (n >= (int)sizeof(current) || n < 0)
				result = ISC_R_NOSPACE;
			else
				result = isc_file_remove(current);
			if (result != ISC_R_SUCCESS &&
			    result != ISC_R_FILENOTFOUND)
				syslog(LOG_ERR,
				       "unable to remove log file '%s.%d': %s",
				       path, greatest,
				       isc_result_totext(result));
		}

	for (i = greatest; i > 0; i--) {
		result = ISC_R_SUCCESS;
		n = snprintf(current, sizeof(current), "%s.%d", path, i - 1);
		if (n >= (int)sizeof(current) || n < 0)
			result = ISC_R_NOSPACE;
		if (result == ISC_R_SUCCESS) {
			n = snprintf(new, sizeof(new), "%s.%d", path, i);
			if (n >= (int)sizeof(new) || n < 0)
				result = ISC_R_NOSPACE;
		}
		if (result == ISC_R_SUCCESS)
			result = isc_file_rename(current, new);
		if (result != ISC_R_SUCCESS &&
		    result != ISC_R_FILENOTFOUND)
			syslog(LOG_ERR,
			       "unable to rename log file '%s.%d' to "
			       "'%s.%d': %s", path, i - 1, path, i,
			       isc_result_totext(result));
	}

	if (FILE_VERSIONS(channel) != 0) {
		n = snprintf(new, sizeof(new), "%s.0", path);
		if (n >= (int)sizeof(new) || n < 0)
			result = ISC_R_NOSPACE;
		else
			result = isc_file_rename(path, new);
		if (result != ISC_R_SUCCESS &&
		    result != ISC_R_FILENOTFOUND)
			syslog(LOG_ERR,
			       "unable to rename log file '%s' to '%s.0': %s",
			       path, path, isc_result_totext(result));
	} else {
		result = isc_file_remove(path);
		if (result != ISC_R_SUCCESS &&
		    result != ISC_R_FILENOTFOUND)
			syslog(LOG_ERR, "unable to remove log file '%s': %s",
			       path, isc_result_totext(result));
	}

	return (ISC_R_SUCCESS);
}

static isc_result_t
isc_log_open(isc_logchannel_t *channel) {
	struct stat statbuf;
	isc_boolean_t regular_file;
	isc_boolean_t roll = ISC_FALSE;
	isc_result_t result = ISC_R_SUCCESS;
	const char *path;

	REQUIRE(channel->type == ISC_LOG_TOFILE);
	REQUIRE(FILE_STREAM(channel) == NULL);

	path = FILE_NAME(channel);

	REQUIRE(path != NULL && *path != '\0');

	/*
	 * Determine type of file; only regular files will be
	 * version renamed, and only if the base file exists
	 * and either has no size limit or has reached its size limit.
	 */
	if (stat(path, &statbuf) == 0) {
		regular_file = S_ISREG(statbuf.st_mode) ? ISC_TRUE : ISC_FALSE;
		/* XXXDCL if not regular_file complain? */
		if ((FILE_MAXSIZE(channel) == 0 &&
		     FILE_VERSIONS(channel) != ISC_LOG_ROLLNEVER) ||
		    (FILE_MAXSIZE(channel) > 0 &&
		     statbuf.st_size >= FILE_MAXSIZE(channel)))
			roll = regular_file;
	} else if (errno == ENOENT)
		regular_file = ISC_TRUE;
	else
		result = ISC_R_INVALIDFILE;

	/*
	 * Version control.
	 */
	if (result == ISC_R_SUCCESS && roll) {
		if (FILE_VERSIONS(channel) == ISC_LOG_ROLLNEVER)
			return (ISC_R_MAXSIZE);
		result = roll_log(channel);
		if (result != ISC_R_SUCCESS) {
			if ((channel->flags & ISC_LOG_OPENERR) == 0) {
				syslog(LOG_ERR,
				       "isc_log_open: roll_log '%s' "
				       "failed: %s",
				       FILE_NAME(channel),
				       isc_result_totext(result));
				channel->flags |= ISC_LOG_OPENERR;
			}
			return (result);
		}
	}

	result = isc_stdio_open(path, "a", &FILE_STREAM(channel));

	return (result);
}

isc_boolean_t
isc_log_wouldlog(isc_log_t *lctx, int level) {
	/*
	 * Try to avoid locking the mutex for messages which can't
	 * possibly be logged to any channels -- primarily debugging
	 * messages that the debug level is not high enough to print.
	 *
	 * If the level is (mathematically) less than or equal to the
	 * highest_level, or if there is a dynamic channel and the level is
	 * less than or equal to the debug level, the main loop must be
	 * entered to see if the message should really be output.
	 *
	 * NOTE: this is UNLOCKED access to the logconfig.  However,
	 * the worst thing that can happen is that a bad decision is made
	 * about returning without logging, and that's not a big concern,
	 * because that's a risk anyway if the logconfig is being
	 * dynamically changed.
	 */

	if (lctx == NULL || lctx->logconfig == NULL)
		return (ISC_FALSE);

	return (ISC_TF(level <= lctx->logconfig->highest_level ||
		       (lctx->logconfig->dynamic &&
			level <= lctx->debug_level)));
}

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)
{
	int syslog_level;
	char time_string[64];
	char level_string[24];
	const char *iformat;
	struct stat statbuf;
	isc_boolean_t matched = ISC_FALSE;
	isc_boolean_t printtime, printtag;
	isc_boolean_t printcategory, printmodule, printlevel;
	isc_logconfig_t *lcfg;
	isc_logchannel_t *channel;
	isc_logchannellist_t *category_channels;
	isc_result_t result;

	REQUIRE(lctx == NULL || VALID_CONTEXT(lctx));
	REQUIRE(category != NULL);
	REQUIRE(module != NULL);
	REQUIRE(level != ISC_LOG_DYNAMIC);
	REQUIRE(format != NULL);

	/*
	 * Programs can use libraries that use this logging code without
	 * wanting to do any logging, thus the log context is allowed to
	 * be non-existent.
	 */
	if (lctx == NULL)
		return;

	REQUIRE(category->id < lctx->category_count);
	REQUIRE(module->id < lctx->module_count);

	if (! isc_log_wouldlog(lctx, level))
		return;

	if (msgcat != NULL)
		iformat = isc_msgcat_get(msgcat, msgset, msg, format);
	else
		iformat = format;

	time_string[0]  = '\0';
	level_string[0] = '\0';

	LOCK(&lctx->lock);

	lctx->buffer[0] = '\0';
	
	lcfg = lctx->logconfig;

	category_channels = ISC_LIST_HEAD(lcfg->channellists[category->id]);

	/*
	 * XXXDCL add duplicate filtering? (To not write multiple times to
	 * the same source via various channels).
	 */
	do {
		/*
		 * If the channel list end was reached and a match was made,
		 * everything is finished.
		 */
		if (category_channels == NULL && matched)
			break;

		if (category_channels == NULL && ! matched &&
		    category_channels != ISC_LIST_HEAD(lcfg->channellists[0]))
			/*
			 * No category/module pair was explicitly configured.
			 * Try the category named "default".
			 */
			category_channels =
				ISC_LIST_HEAD(lcfg->channellists[0]);

		if (category_channels == NULL && ! matched)
			/*
			 * No matching module was explicitly configured
			 * for the category named "default".  Use the internal
			 * default channel.
			 */
			category_channels = &default_channel;

		if (category_channels->module != NULL &&
		    category_channels->module != module) {
			category_channels = ISC_LIST_NEXT(category_channels,
							  link);
			continue;
		}

		matched = ISC_TRUE;

		channel = category_channels->channel;
		category_channels = ISC_LIST_NEXT(category_channels, link);

		if (((channel->flags & ISC_LOG_DEBUGONLY) != 0) &&
		    lctx->debug_level == 0)
			continue;

		if (channel->level == ISC_LOG_DYNAMIC) {
			if (lctx->debug_level < level)
				continue;
		} else if (channel->level < level)
			continue;

		if ((channel->flags & ISC_LOG_PRINTTIME) != 0 &&
		    time_string[0] == '\0') {
			isc_time_t isctime;
			
			TIME_NOW(&isctime);
			isc_time_formattimestamp(&isctime, time_string,
						 sizeof(time_string));
		}

		if ((channel->flags & ISC_LOG_PRINTLEVEL) != 0 &&
		    level_string[0] == '\0') {
			if (level < ISC_LOG_CRITICAL)
				snprintf(level_string, sizeof(level_string),
					 isc_msgcat_get(isc_msgcat,
						        ISC_MSGSET_LOG,
						        ISC_MSG_LEVEL,
						        "level %d: "),
					 level);
			else if (level > ISC_LOG_DYNAMIC)
				snprintf(level_string, sizeof(level_string),
					 "%s %d: ", log_level_strings[0],
					 level);
			else
				snprintf(level_string, sizeof(level_string),
					 "%s: ", log_level_strings[-level]);
		}

		/*
		 * Only format the message once.
		 */
		if (lctx->buffer[0] == '\0') {
			(void)vsnprintf(lctx->buffer, sizeof(lctx->buffer),
					iformat, args);

			/*
			 * Check for duplicates.
			 */
			if (write_once) {
				isc_logmessage_t *message, *new;
				isc_time_t oldest;
				isc_interval_t interval;

				isc_interval_set(&interval,
						 lcfg->duplicate_interval, 0);

				/*
				 * 'oldest' is the age of the oldest messages
				 * which fall within the duplicate_interval
				 * range.
				 */
				TIME_NOW(&oldest);
				if (isc_time_subtract(&oldest, &interval, &oldest)
				    != ISC_R_SUCCESS)
					/*
					 * Can't effectively do the checking
					 * without having a valid time.
					 */
					message = NULL;
				else
					message =ISC_LIST_HEAD(lctx->messages);

				while (message != NULL) {
					if (isc_time_compare(&message->time,
							     &oldest) < 0) {
						/*
						 * This message is older
						 * than the duplicate_interval,
						 * so it should be dropped from
						 * the history.
						 *
						 * Setting the interval to be
						 * to be longer will obviously
						 * not cause the expired
						 * message to spring back into
						 * existence.
						 */
						new = ISC_LIST_NEXT(message,
								    link);

						ISC_LIST_UNLINK(lctx->messages,
								message, link);

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

						message = new;
						continue;
					}

					/*
					 * This message is in the duplicate
					 * filtering interval ...
					 */
					if (strcmp(lctx->buffer, message->text)
					    == 0) {
						/*
						 * ... and it is a duplicate.
						 * Unlock the mutex and
						 * get the hell out of Dodge.
						 */
						UNLOCK(&lctx->lock);
						return;
					}

					message = ISC_LIST_NEXT(message, link);
				}

				/*
				 * It wasn't in the duplicate interval,
				 * so add it to the message list.
				 */
				new = isc_mem_get(lctx->mctx,
						  sizeof(isc_logmessage_t) +
						  strlen(lctx->buffer) + 1);
				if (new != NULL) {
					/*
					 * Put the text immediately after
					 * the struct.  The strcpy is safe.
					 */
					new->text = (char *)(new + 1);
					strcpy(new->text, lctx->buffer);

					TIME_NOW(&new->time);

					ISC_LIST_APPEND(lctx->messages,
							new, link);
				}
			}
		}

		printtime     = ISC_TF((channel->flags & ISC_LOG_PRINTTIME)
				       != 0);
		printtag      = ISC_TF((channel->flags & ISC_LOG_PRINTTAG)
				       != 0 && lcfg->tag != NULL);
		printcategory = ISC_TF((channel->flags & ISC_LOG_PRINTCATEGORY)
				       != 0);
		printmodule   = ISC_TF((channel->flags & ISC_LOG_PRINTMODULE)
				       != 0);
		printlevel    = ISC_TF((channel->flags & ISC_LOG_PRINTLEVEL)
				       != 0);

		switch (channel->type) {
		case ISC_LOG_TOFILE:
			if (FILE_MAXREACHED(channel)) {
				/*
				 * If the file can be rolled, OR
				 * If the file no longer exists, OR
				 * If the file is less than the maximum size,
				 *    (such as if it had been renamed and
				 *     a new one touched, or it was truncated
				 *     in place)
				 * ... then close it to trigger reopening.
				 */
				if (FILE_VERSIONS(channel) !=
				    ISC_LOG_ROLLNEVER ||
				    (stat(FILE_NAME(channel), &statbuf) != 0 &&
				     errno == ENOENT) ||
				    statbuf.st_size < FILE_MAXSIZE(channel)) {
					(void)fclose(FILE_STREAM(channel));
					FILE_STREAM(channel) = NULL;
					FILE_MAXREACHED(channel) = ISC_FALSE;
				} else
					/*
					 * Eh, skip it.
					 */
					break;
			}

			if (FILE_STREAM(channel) == NULL) {
				result = isc_log_open(channel);
				if (result != ISC_R_SUCCESS &&
				    result != ISC_R_MAXSIZE &&
				    (channel->flags & ISC_LOG_OPENERR) == 0) {
					syslog(LOG_ERR,
					       "isc_log_open '%s' failed: %s",
					       FILE_NAME(channel),
					       isc_result_totext(result));
					channel->flags |= ISC_LOG_OPENERR;
				}
				if (result != ISC_R_SUCCESS)
					break;
				channel->flags &= ~ISC_LOG_OPENERR;
			}
			/* FALLTHROUGH */

		case ISC_LOG_TOFILEDESC:
			fprintf(FILE_STREAM(channel), "%s%s%s%s%s%s%s%s%s%s\n",
				printtime     ? time_string	: "",
				printtime     ? " "		: "",
				printtag      ? lcfg->tag	: "",
				printtag      ? ": "		: "",
				printcategory ? category->name	: "",
				printcategory ? ": "		: "",
				printmodule   ? (module != NULL ? module->name
						 		: "no_module")
					      			: "",
				printmodule   ? ": "		: "",
				printlevel    ? level_string	: "",
				lctx->buffer);

			fflush(FILE_STREAM(channel));

			/*
			 * If the file now exceeds its maximum size
			 * threshold, note it so that it will not be logged
			 * to any more.
			 */
			if (FILE_MAXSIZE(channel) > 0) {
				INSIST(channel->type == ISC_LOG_TOFILE);

				/* XXXDCL NT fstat/fileno */
				/* XXXDCL complain if fstat fails? */
				if (fstat(fileno(FILE_STREAM(channel)),
					  &statbuf) >= 0 &&
				    statbuf.st_size > FILE_MAXSIZE(channel))
					FILE_MAXREACHED(channel) = ISC_TRUE;
			}

			break;

		case ISC_LOG_TOSYSLOG:
			if (level > 0)
				syslog_level = LOG_DEBUG;
			else if (level < ISC_LOG_CRITICAL)
				syslog_level = LOG_CRIT;
			else
				syslog_level = syslog_map[-level];

			(void)syslog(FACILITY(channel) | syslog_level,
			       "%s%s%s%s%s%s%s%s%s",
			       printtime     ? time_string	: "",
			       printtag      ? lcfg->tag	: "",
			       printtag      ? ": "		: "",
			       printcategory ? category->name	: "",
			       printcategory ? ": "		: "",
			       printmodule   ? (module != NULL	? module->name
						 		: "no_module")
					      			: "",
			       printmodule   ? ": "		: "",
			       printlevel    ? level_string	: "",
			       lctx->buffer);
			break;

		case ISC_LOG_TONULL:
			break;

		}

	} while (1);

	UNLOCK(&lctx->lock);
}