sdlz_helper.c

来自「非常好的dns解析软件」· C语言 代码 · 共 532 行 · 第 1/2 页

/*
 * Copyright (C) 2002 Stichting NLnet, Netherlands, [e-mail].
 *
 * 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 STICHTING NLNET
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * STICHTING NLNET 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.
 *
 * The development of Dynamically Loadable Zones (DLZ) for Bind 9 was
 * conceived and contributed by Rob Butler.
 *
 * 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 ROB BUTLER
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * ROB BUTLER 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.
 */

/*
 * Copyright (C) 1999-2001  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 INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM 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.
 */

#ifdef DLZ

#include <config.h>

#include <dns/log.h>
#include <dns/result.h>

#include <isc/mem.h>
#include <isc/result.h>
#include <isc/string.h>
#include <isc/util.h>

#include <dlz/sdlz_helper.h>

/*
 * sdlz helper methods
 */

/*%
 * properly destroys a querylist by de-allocating the
 * memory for each query segment, and then the list itself
 */

static void
destroy_querylist(isc_mem_t *mctx, query_list_t **querylist)
{
	query_segment_t *tseg = NULL;
	query_segment_t *nseg = NULL;

	REQUIRE(mctx != NULL);

	/* if query list is null, nothing to do */
	if (*querylist == NULL)
		return;

	/* start at the top of the list */
	nseg = ISC_LIST_HEAD(**querylist);
	while (nseg != NULL) {	/* loop, until end of list */
		tseg = nseg;
		/*
		 * free the query segment's text string but only if it
		 * was really a query segment, and not a pointer to
		 * %zone%, or %record%, or %client%
		*/
		if (tseg->sql != NULL && tseg->direct == isc_boolean_true)
			isc_mem_free(mctx, tseg->sql);
		/* get the next query segment, before we destroy this one. */
		nseg = ISC_LIST_NEXT(nseg, link);
		/* deallocate this query segment. */
		isc_mem_put(mctx, tseg, sizeof(query_segment_t));
	}
	/* deallocate the query segment list */
	isc_mem_put(mctx, *querylist, sizeof(query_list_t));
}

/*% constructs a query list by parsing a string into query segments */
static isc_result_t
build_querylist(isc_mem_t *mctx, const char *query_str, char **zone,
		char **record, char **client, query_list_t **querylist,
		unsigned int flags)
{
	isc_result_t result;
	isc_boolean_t foundzone = isc_boolean_false;
	isc_boolean_t foundrecord = isc_boolean_false;
	isc_boolean_t foundclient = isc_boolean_false;
	char *temp_str = NULL;
	char *right_str = NULL;
	query_list_t *tql;
	query_segment_t *tseg = NULL;

	REQUIRE(querylist != NULL && *querylist == NULL);
	REQUIRE(mctx != NULL);

	/* if query string is null, or zero length */
	if (query_str == NULL || strlen(query_str) < 1) {
		if ((flags & SDLZH_REQUIRE_QUERY) == 0)
			/* we don't need it were ok. */
			return (ISC_R_SUCCESS);
		else
			/* we did need it, PROBLEM!!! */
			return (ISC_R_FAILURE);
	}

	/* allocate memory for query list */
	tql = isc_mem_get(mctx, sizeof(query_list_t));
	/* couldn't allocate memory.  Problem!! */
	if (tql == NULL)
		return (ISC_R_NOMEMORY);

	/* initialize the query segment list */
	ISC_LIST_INIT(*tql);

	/* make a copy of query_str so we can chop it up */
	temp_str = right_str = isc_mem_strdup(mctx, query_str);
	/* couldn't make a copy, problem!! */
	if (right_str == NULL) {
		result = ISC_R_NOMEMORY;
		goto cleanup;
	}

	/* loop through the string and chop it up */
	while (right_str != NULL) {
		/* allocate memory for tseg */
		tseg = isc_mem_get(mctx, sizeof(query_segment_t));
		if (tseg  == NULL) {	/* no memory, clean everything up. */
			result = ISC_R_NOMEMORY;
			goto cleanup;
		}
		tseg->sql = NULL;
		tseg->direct = isc_boolean_false;
		/* initialize the query segment link */
		ISC_LINK_INIT(tseg, link);
		/* append the query segment to the list */
		ISC_LIST_APPEND(*tql, tseg, link);

		/*
		 * split string at the first "%". set query segment to
		 * left portion
		 */
		tseg->sql = isc_mem_strdup(mctx,
					   isc_string_separate(&right_str,
							       "%"));
		if (tseg->sql == NULL) {
			/* no memory, clean everything up. */
			result = ISC_R_NOMEMORY;
			goto cleanup;
		}
		/* tseg->sql points directly to a string. */
		tseg->direct = isc_boolean_true;
		tseg->strlen = strlen(tseg->sql);

		/* check if we encountered "%zone%" token */
		if (strcasecmp(tseg->sql, "zone") == 0) {
			/*
			 * we don't really need, or want the "zone"
			 * text, so get rid of it.
			 */
			isc_mem_free(mctx, tseg->sql);
			/* set tseg->sql to in-direct zone string */
			tseg->sql = (char**) zone;
			tseg->strlen = 0;
			/* tseg->sql points in-directly to a string */
			tseg->direct = isc_boolean_false;
			foundzone = isc_boolean_true;
			/* check if we encountered "%record%" token */
		} else if (strcasecmp(tseg->sql, "record") == 0) {
			/*
			 * we don't really need, or want the "record"
			 * text, so get rid of it.
			 */
			isc_mem_free(mctx, tseg->sql);
			/* set tseg->sql to in-direct record string */
			tseg->sql = (char**) record;
			tseg->strlen = 0;
			/* tseg->sql points in-directly poinsts to a string */
			tseg->direct = isc_boolean_false;
			foundrecord = isc_boolean_true;
			/* check if we encountered "%client%" token */
		} else if (strcasecmp(tseg->sql, "client") == 0) {
			/*
			 * we don't really need, or want the "client"
			 * text, so get rid of it.
			 */
			isc_mem_free(mctx, tseg->sql);
			/* set tseg->sql to in-direct record string */
			tseg->sql = (char**) client;
			tseg->strlen = 0;
			/* tseg->sql points in-directly poinsts to a string */
			tseg->direct = isc_boolean_false;
			foundclient = isc_boolean_true;
		}
	}

	/* we don't need temp_str any more */
	isc_mem_free(mctx, temp_str);
	/*
	 * add checks later to verify zone and record are found if
	 * necessary.
	 */

	/* if this query requires %client%, make sure we found it */
	if (((flags & SDLZH_REQUIRE_CLIENT) != 0) && (!foundclient) ) {
		/* Write error message to log */
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Required token %%client%% not found.");
		result = ISC_R_FAILURE;
		goto flag_fail;
	}

	/* if this query requires %record%, make sure we found it */
	if (((flags & SDLZH_REQUIRE_RECORD) != 0) && (!foundrecord) ) {
		/* Write error message to log */
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Required token %%record%% not found.");
		result = ISC_R_FAILURE;
		goto flag_fail;
	}

	/* if this query requires %zone%, make sure we found it */
	if (((flags & SDLZH_REQUIRE_ZONE) != 0) && (!foundzone) ) {
		/* Write error message to log */
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "Required token %%zone%% not found.");
		result = ISC_R_FAILURE;
		goto flag_fail;
	}

	/* pass back the query list */
	*querylist = (query_list_t *) tql;

	/* return success */