dlz_bdbhpt_driver.c

来自「非常好的dns解析软件」· C语言 代码 · 共 861 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_BDB

#include <config.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

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

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

#include <named/globals.h>

#include <dlz/dlz_bdbhpt_driver.h>

#include <db.h>

static dns_sdlzimplementation_t *dlz_bdbhpt = NULL;

/* should the bdb driver use threads. */
#ifdef ISC_PLATFORM_USETHREADS
#define bdbhpt_threads DB_THREAD
#else
#define bdbhpt_threads 0
#endif

/* bdbhpt database names */
#define dlz_data "dns_data"
#define dlz_zone "dns_zone"
#define dlz_xfr "dns_xfr"
#define dlz_client "dns_client"

	/* This structure contains all the Berkeley DB handles
	 * for this instance of the bdbhpt driver.
	 */

typedef struct bdbhpt_instance {
	DB_ENV	*dbenv;		/*%< bdbhpt environment */
	DB	*data;		/*%< dns_data database handle */
	DB	*zone;		/*%< zone database handle */
	DB	*xfr;		/*%< zone xfr database handle */
	DB	*client;	/*%< client database handle */
	isc_mem_t *mctx;	/*%< memory context */

} bdbhpt_instance_t;

typedef struct bdbhpt_parsed_data {
	char *host;
	char *type;
	int ttl;
	char *data;
} bdbhpt_parsed_data_t;


/* forward reference */

static isc_result_t
bdbhpt_findzone(void *driverarg, void *dbdata, const char *name);

/*%
 * Reverses a string in place.
 */

static char *bdbhpt_strrev(char *str)
{
	char *p1, *p2;

	if (! str || ! *str)
		return str;
	for (p1 = str, p2 = str + strlen(str) - 1; p2 > p1; ++p1, --p2)
	{
		*p1 ^= *p2;
		*p2 ^= *p1;
		*p1 ^= *p2;
	}
	return str;
}

/*%
 * Parses the DBT from the Berkeley DB into a parsed_data record
 * The parsed_data record should be allocated before and passed into the
 * bdbhpt_parse_data function.  The char (type & data) fields should not
 * be "free"d as that memory is part of the DBT data field.  It will be
 * "free"d when the DBT is freed.
 */

static isc_result_t
bdbhpt_parse_data(char *in, bdbhpt_parsed_data_t *pd) {

	char *endp, *ttlStr;
	char *tmp = in;
	char *lastchar = (char *) &tmp[strlen(tmp)];

	/*%
	 * String should be formated as:
	 *   replication_id
	 *   (a space)
	 *   host_name
	 *   (a space)
	 *   ttl
	 *   (a space)
	 *   type
	 *   (a space)
	 *   remaining data
	 *
	 * examples:
	 *
	 * 9191 host 10 A 127.0.0.1
	 * server1_212 host 10 A 127.0.0.2
	 * {xxxx-xxxx-xxxx-xxxx-xxxx} host 10 MX 20 mail.example.com
	 */

	/*
	 * we don't need the replication id, so don't
	 * bother saving a pointer to it.
	 */

	/* find space after replication id */
	tmp = strchr(tmp, ' ');
	/* verify we found a space */
	if (tmp == NULL)
		return ISC_R_FAILURE;
	/* make sure it is safe to increment pointer */
	if (++tmp > lastchar)
		return ISC_R_FAILURE;

	/* save pointer to host */
	pd->host = tmp;

	/* find space after host and change it to a '\0' */
	tmp = strchr(tmp, ' ');
	/* verify we found a space */
	if (tmp == NULL)
		return ISC_R_FAILURE;
	/* change the space to a null (string terminator) */
	tmp[0] = '\0';
	/* make sure it is safe to increment pointer */
	if (++tmp > lastchar)
		return ISC_R_FAILURE;

	/* save pointer to ttl string */
	ttlStr = tmp;

	/* find space after ttl and change it to a '\0' */
	tmp = strchr(tmp, ' ');
	/* verify we found a space */
	if (tmp == NULL)
		return ISC_R_FAILURE;
	/* change the space to a null (string terminator) */
	tmp[0] = '\0';
	/* make sure it is safe to increment pointer */
	if (++tmp > lastchar)
		return ISC_R_FAILURE;

	/* save pointer to dns type */
	pd->type = tmp;

	/* find space after type and change it to a '\0' */
	tmp = strchr(tmp, ' ');
	/* verify we found a space */
	if (tmp == NULL)
		return ISC_R_FAILURE;
	/* change the space to a null (string terminator) */
	tmp[0] = '\0';
	/* make sure it is safe to increment pointer */
	if (++tmp > lastchar)
		return ISC_R_FAILURE;

	/* save pointer to remainder of DNS data */
	pd->data = tmp;

	/* convert ttl string to integer */
	pd->ttl = strtol(ttlStr, &endp, 10);
	if (*endp != '\0' || pd->ttl < 0) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "bdbhpt driver ttl must be a postive number");
		return ISC_R_FAILURE;
	}

	/* if we get this far everything should have worked. */
	return ISC_R_SUCCESS;
}

/*
 * DLZ methods
 */

static isc_result_t
bdbhpt_allowzonexfr(void *driverarg, void *dbdata, const char *name,
		    const char *client)
{
	isc_result_t result;
	bdbhpt_instance_t *db = (bdbhpt_instance_t *) dbdata;
	DBT key, data;

	/* check to see if we are authoritative for the zone first. */
	result = bdbhpt_findzone(driverarg, dbdata, name);
	if (result != ISC_R_SUCCESS)
		return (ISC_R_NOTFOUND);

	memset(&key, 0, sizeof(DBT));
	key.flags = DB_DBT_MALLOC;
	key.data = strdup(name);
	if (key.data == NULL) {
		result = ISC_R_NOMEMORY;
		goto xfr_cleanup;
	}
	key.size = strlen(key.data);

	memset(&data, 0, sizeof(DBT));
	data.flags = DB_DBT_MALLOC;
	data.data = strdup(client);
	if (data.data == NULL) {
		result = ISC_R_NOMEMORY;
		goto xfr_cleanup;
	}
	data.size = strlen(data.data);

	switch(db->client->get(db->client, NULL, &key, &data, DB_GET_BOTH)) {
	case DB_NOTFOUND:
		result = ISC_R_NOTFOUND;
		break;
	case 0:
		result = ISC_R_SUCCESS;
		break;
	default:
		result = ISC_R_FAILURE;
	}

 xfr_cleanup:

	/* free any memory duplicate string in the key field */
	if (key.data != NULL)
		free(key.data);

	/* free any memory allocated to the data field. */
	if (data.data != NULL)
		free(data.data);

	return result;

}

/*%
 * BDB does not allow a secondary index on a database that allows
 * duplicates.  We have a few options:
 *
 * 1) kill speed by having lookup method use a secondary db which
 * is associated to the primary DB with the DNS data.  Then have
 * another secondary db for zone transfer which also points to
 * the dns_data primary.  NO - The  point of this driver is
 * lookup performance.
 *
 * 2) Blow up database size by storing DNS data twice.  Once for
 * the lookup (dns_data) database, and a second time for the zone
 * transfer (dns_xfr) database. NO - That would probably require
 * a larger cache to provide good performance.  Also, that would
 * make the DB larger on disk potentially slowing it as well.
 *
 * 3) Loop through the dns_xfr database with a cursor to get
 * all the different hosts in a zone.  Then use the zone & host
 * together to lookup the data in the dns_data database. YES -
 * This may slow down zone xfr's a little, but that's ok they
 * don't happen as often and don't need to be as fast. We can
 * also use this table when deleting a zone (The BDB driver
 * is read only - the delete would be used during replication
 * updates by a separate process).
 */

static isc_result_t
bdbhpt_allnodes(const char *zone, void *driverarg, void *dbdata,
		dns_sdlzallnodes_t *allnodes)
{

	isc_result_t result = ISC_R_NOTFOUND;
	bdbhpt_instance_t *db = (bdbhpt_instance_t *) dbdata;
	DBC *xfr_cursor = NULL;
	DBC *dns_cursor = NULL;
	DBT xfr_key, xfr_data, dns_key, dns_data;
	int xfr_flags;
	int dns_flags;
	int bdbhptres;
	bdbhpt_parsed_data_t pd;
	char *tmp = NULL, *tmp_zone, *tmp_zone_host = NULL;

	UNUSED(driverarg);

	memset(&xfr_key, 0, sizeof(DBT));
	memset(&xfr_data, 0, sizeof(DBT));
	memset(&dns_key, 0, sizeof(DBT));
	memset(&dns_data, 0, sizeof(DBT));

	xfr_key.data = tmp_zone = strdup(zone);
	if (xfr_key.data == NULL)
		return (ISC_R_NOMEMORY);

	xfr_key.size = strlen(xfr_key.data);

	/* get a cursor to loop through dns_xfr table */
	if (db->xfr->cursor(db->xfr, NULL, &xfr_cursor, 0) != 0) {
		result = ISC_R_FAILURE;
		goto allnodes_cleanup;
	}

	/* get a cursor to loop through dns_data table */
	if (db->data->cursor(db->data, NULL, &dns_cursor, 0) != 0) {
		result = ISC_R_FAILURE;
		goto allnodes_cleanup;
	}

	xfr_flags = DB_SET;

	/* loop through xfr table for specified zone. */
	while ((bdbhptres = xfr_cursor->c_get(xfr_cursor, &xfr_key, &xfr_data,
					      xfr_flags)) == 0) {

		xfr_flags = DB_NEXT_DUP;

		/* +1 to allow for space between zone and host names */
		dns_key.size = xfr_data.size + xfr_key.size + 1;

		/* +1 to allow for null term at end of string. */
		dns_key.data = tmp_zone_host = malloc(dns_key.size + 1);
		if (dns_key.data == NULL)
			goto allnodes_cleanup;

		/*
		 * construct search key for dns_data.
		 * zone_name(a space)host_name
		 */
		strcpy(dns_key.data, zone);
		strcat(dns_key.data, " ");
		strncat(dns_key.data, xfr_data.data, xfr_data.size);

		dns_flags = DB_SET;

		while ((bdbhptres = dns_cursor->c_get(dns_cursor, &dns_key,
						      &dns_data,
						      dns_flags)) == 0) {

			dns_flags = DB_NEXT_DUP;

			/* +1 to allow for null term at end of string. */
			tmp = realloc(tmp, dns_data.size + 1);
			if (tmp == NULL)
				goto allnodes_cleanup;

			/* copy data to tmp string, and append null term. */
			strncpy(tmp, dns_data.data, dns_data.size);
			tmp[dns_data.size] = '\0';

			/* split string into dns data parts. */
			if (bdbhpt_parse_data(tmp, &pd) != ISC_R_SUCCESS)
				goto allnodes_cleanup;

			result = dns_sdlz_putnamedrr(allnodes, pd.host,
						     pd.type, pd.ttl, pd.data);
			if (result != ISC_R_SUCCESS)
				goto allnodes_cleanup;

		}  /* end inner while loop */

		/* clean up memory */
		if (tmp_zone_host != NULL) {
			free(tmp_zone_host);
			tmp_zone_host = NULL;
		}
	} /* end outer while loop */

 allnodes_cleanup:

	/* free any memory */
	if (tmp != NULL)