query.c

bind 9.3结合mysql数据库

		goto found;

	if (dns_rdataset_isassociated(rdataset))
		dns_rdataset_disassociate(rdataset);
	if (sigrdataset != NULL && dns_rdataset_isassociated(sigrdataset))
		dns_rdataset_disassociate(sigrdataset);
	if (node != NULL)
		dns_db_detachnode(db, &node);
	dns_db_detach(&db);

 try_glue:
	/*
	 * No cached data was found.  Glue is our last chance.
	 * RFC1035 sayeth:
	 *
	 *	NS records cause both the usual additional section
	 *	processing to locate a type A record, and, when used
	 *	in a referral, a special search of the zone in which
	 *	they reside for glue information.
	 *
	 * This is the "special search".  Note that we must search
	 * the zone where the NS record resides, not the zone it
	 * points to, and that we only do the search in the delegation
	 * case (identified by client->query.gluedb being set).
	 */

	if (client->query.gluedb == NULL)
		goto cleanup;

	/*
	 * Don't poision caches using the bailiwick protection model.
	 */
	if (!dns_name_issubdomain(name, dns_db_origin(client->query.gluedb)))
		goto cleanup;

	dns_db_attach(client->query.gluedb, &db);
	result = dns_db_find(db, name, version, type,
			     client->query.dboptions | DNS_DBFIND_GLUEOK,
			     client->now, &node, fname, rdataset,
			     sigrdataset);
	if (!(result == ISC_R_SUCCESS ||
	      result == DNS_R_ZONECUT ||
	      result == DNS_R_GLUE))
		goto cleanup;

 found:
	/*
	 * We have found a potential additional data rdataset, or
	 * at least a node to iterate over.
	 */
	query_keepname(client, fname, dbuf);

	/*
	 * If we have an rdataset, add it to the additional data
	 * section.
	 */
	mname = NULL;
	if (dns_rdataset_isassociated(rdataset) &&
	    !query_isduplicate(client, fname, type, &mname)) {
		if (mname != NULL) {
			query_releasename(client, &fname);
			fname = mname;
		} else
			need_addname = ISC_TRUE;
		ISC_LIST_APPEND(fname->list, rdataset, link);
		trdataset = rdataset;
		rdataset = NULL;
		added_something = ISC_TRUE;
		/*
		 * Note: we only add SIGs if we've added the type they cover,
		 * so we do not need to check if the SIG rdataset is already
		 * in the response.
		 */
		if (sigrdataset != NULL &&
		    dns_rdataset_isassociated(sigrdataset))
		{
			ISC_LIST_APPEND(fname->list, sigrdataset, link);
			sigrdataset = NULL;
		}
	}

	if (qtype == dns_rdatatype_a) {
		/*
		 * We now go looking for A and AAAA records, along with
		 * their signatures.
		 *
		 * XXXRTH  This code could be more efficient.
		 */
		if (rdataset != NULL) {
			if (dns_rdataset_isassociated(rdataset))
				dns_rdataset_disassociate(rdataset);
		} else {
			rdataset = query_newrdataset(client);
			if (rdataset == NULL)
				goto addname;
		}
		if (sigrdataset != NULL) {
			if (dns_rdataset_isassociated(sigrdataset))
				dns_rdataset_disassociate(sigrdataset);
		} else if (WANTDNSSEC(client)) {
			sigrdataset = query_newrdataset(client);
			if (sigrdataset == NULL)
				goto addname;
		}
		result = dns_db_findrdataset(db, node, version,
					     dns_rdatatype_a, 0,
					     client->now, rdataset,
					     sigrdataset);
		if (result == DNS_R_NCACHENXDOMAIN)
			goto addname;
		if (result == DNS_R_NCACHENXRRSET) {
			dns_rdataset_disassociate(rdataset);
			/*
			 * Negative cache entries don't have sigrdatasets.
			 */
			INSIST(sigrdataset == NULL ||
			       ! dns_rdataset_isassociated(sigrdataset));
		}
		if (result == ISC_R_SUCCESS) {
			mname = NULL;
			if (!query_isduplicate(client, fname,
					       dns_rdatatype_a, &mname)) {
				if (mname != NULL) {
					query_releasename(client, &fname);
					fname = mname;
				} else
					need_addname = ISC_TRUE;
				ISC_LIST_APPEND(fname->list, rdataset, link);
				added_something = ISC_TRUE;
				if (sigrdataset != NULL &&
				    dns_rdataset_isassociated(sigrdataset))
				{
					ISC_LIST_APPEND(fname->list,
							sigrdataset, link);
					sigrdataset =
						query_newrdataset(client);
				}
				rdataset = query_newrdataset(client);
				if (rdataset == NULL)
					goto addname;
				if (WANTDNSSEC(client) && sigrdataset == NULL)
					goto addname;
			} else {
				dns_rdataset_disassociate(rdataset);
				if (sigrdataset != NULL &&
				    dns_rdataset_isassociated(sigrdataset))
					dns_rdataset_disassociate(sigrdataset);
			}
		}
		result = dns_db_findrdataset(db, node, version,
					     dns_rdatatype_aaaa, 0,
					     client->now, rdataset,
					     sigrdataset);
		if (result == DNS_R_NCACHENXDOMAIN)
			goto addname;
		if (result == DNS_R_NCACHENXRRSET) {
			dns_rdataset_disassociate(rdataset);
			INSIST(sigrdataset == NULL ||
			       ! dns_rdataset_isassociated(sigrdataset));
		}
		if (result == ISC_R_SUCCESS) {
			mname = NULL;
			if (!query_isduplicate(client, fname,
					       dns_rdatatype_aaaa, &mname)) {
				if (mname != NULL) {
					query_releasename(client, &fname);
					fname = mname;
				} else
					need_addname = ISC_TRUE;
				ISC_LIST_APPEND(fname->list, rdataset, link);
				added_something = ISC_TRUE;
				if (sigrdataset != NULL &&
				    dns_rdataset_isassociated(sigrdataset))
				{
					ISC_LIST_APPEND(fname->list,
							sigrdataset, link);
					sigrdataset = NULL;
				}
				rdataset = NULL;
			}
		}
	}

 addname:
	CTRACE("query_addadditional: addname");
	/*
	 * If we haven't added anything, then we're done.
	 */
	if (!added_something)
		goto cleanup;

	/*
	 * We may have added our rdatasets to an existing name, if so, then
	 * need_addname will be ISC_FALSE.  Whether we used an existing name
	 * or a new one, we must set fname to NULL to prevent cleanup.
	 */
	if (need_addname)
		dns_message_addname(client->message, fname,
				    DNS_SECTION_ADDITIONAL);
	fname = NULL;

	/*
	 * In a few cases, we want to add additional data for additional
	 * data.  It's simpler to just deal with special cases here than
	 * to try to create a general purpose mechanism and allow the
	 * rdata implementations to do it themselves.
	 *
	 * This involves recursion, but the depth is limited.  The
	 * most complex case is adding a SRV rdataset, which involves
	 * recursing to add address records, which in turn can cause
	 * recursion to add KEYs.
	 */
	if (type == dns_rdatatype_a || type == dns_rdatatype_aaaa) {
		/*
		 * RFC 2535 section 3.5 says that when A or AAAA records are
		 * retrieved as additional data, any KEY RRs for the owner name
		 * should be added to the additional data section.
		 *
		 * XXXRTH  We should lower the priority here.  Alternatively,
		 * we could raise the priority of glue records.
		 */
		eresult = query_addadditional(client, name, dns_rdatatype_dnskey);
 	} else if (type == dns_rdatatype_srv && trdataset != NULL) {
		/*
		 * If we're adding SRV records to the additional data
		 * section, it's helpful if we add the SRV additional data
		 * as well.
		 */
		eresult = dns_rdataset_additionaldata(trdataset,
						      query_addadditional,
						      client);
	}

 cleanup:
	CTRACE("query_addadditional: cleanup");
	query_putrdataset(client, &rdataset);
	if (sigrdataset != NULL)
		query_putrdataset(client, &sigrdataset);
	if (fname != NULL)
		query_releasename(client, &fname);
	if (node != NULL)
		dns_db_detachnode(db, &node);
	if (db != NULL)
		dns_db_detach(&db);
	if (zone != NULL)
		dns_zone_detach(&zone);

	CTRACE("query_addadditional: done");
	return (eresult);
}

static inline void
query_addrdataset(ns_client_t *client, dns_name_t *fname,
		  dns_rdataset_t *rdataset)
{
	dns_rdatatype_t type = rdataset->type;

	/*
	 * Add 'rdataset' and any pertinent additional data to
	 * 'fname', a name in the response message for 'client'.
	 */

	CTRACE("query_addrdataset");

	ISC_LIST_APPEND(fname->list, rdataset, link);

	if (client->view->order != NULL)
		rdataset->attributes |= dns_order_find(client->view->order,
						       fname, rdataset->type,
						       rdataset->rdclass);
	if (NOADDITIONAL(client))
		return;

	/*
	 * Add additional data.
	 *
	 * We don't care if dns_rdataset_additionaldata() fails.
	 */
	(void)dns_rdataset_additionaldata(rdataset,
					  query_addadditional, client);
	/*
	 * RFC 2535 section 3.5 says that when NS, SOA, A, or AAAA records
	 * are retrieved, any KEY RRs for the owner name should be added
	 * to the additional data section.  We treat A6 records the same way.
	 *
	 * We don't care if query_addadditional() fails.
	 */
	if (type == dns_rdatatype_ns || type == dns_rdatatype_soa ||
	    type == dns_rdatatype_a || type == dns_rdatatype_aaaa ||
	    type == dns_rdatatype_a6) {
		/*
		 * XXXRTH  We should lower the priority here.  Alternatively,
		 * we could raise the priority of glue records.
		 */
		(void)query_addadditional(client, fname, dns_rdatatype_dnskey);
	}
	CTRACE("query_addrdataset: done");
}

static void
query_addrrset(ns_client_t *client, dns_name_t **namep,
	       dns_rdataset_t **rdatasetp, dns_rdataset_t **sigrdatasetp,
	       isc_buffer_t *dbuf, dns_section_t section)
{
	dns_name_t *name, *mname;
	dns_rdataset_t *rdataset, *mrdataset, *sigrdataset;
	isc_result_t result;

	/*
	 * To the current response for 'client', add the answer RRset
	 * '*rdatasetp' and an optional signature set '*sigrdatasetp', with
	 * owner name '*namep', to section 'section', unless they are
	 * already there.  Also add any pertinent additional data.
	 *
	 * If 'dbuf' is not NULL, then '*namep' is the name whose data is
	 * stored in 'dbuf'.  In this case, query_addrrset() guarantees that
	 * when it returns the name will either have been kept or released.
	 */
	CTRACE("query_addrrset");
	name = *namep;
	rdataset = *rdatasetp;
	if (sigrdatasetp != NULL)
		sigrdataset = *sigrdatasetp;
	else
		sigrdataset = NULL;
	mname = NULL;
	mrdataset = NULL;
	result = dns_message_findname(client->message, section,
				      name, rdataset->type, rdataset->covers,
				      &mname, &mrdataset);
	if (result == ISC_R_SUCCESS) {
		/*
		 * We've already got an RRset of the given name and type.
		 * There's nothing else to do;
		 */
		CTRACE("query_addrrset: dns_message_findname succeeded: done");
		if (dbuf != NULL)
			query_releasename(client, namep);
		return;
	} else if (result == DNS_R_NXDOMAIN) {
		/*
		 * The name doesn't exist.
		 */
		if (dbuf != NULL)
			query_keepname(client, name, dbuf);
		dns_message_addname(client->message, name, section);
		*namep = NULL;
		mname = name;
	} else {
		RUNTIME_CHECK(result == DNS_R_NXRRSET);
		if (dbuf != NULL)
			query_releasename(client, namep);
	}

	if (rdataset->trust != dns_trust_secure &&
	    (section == DNS_SECTION_ANSWER ||
	     section == DNS_SECTION_AUTHORITY))
		client->query.attributes &= ~NS_QUERYATTR_SECURE;
	/*
	 * Note: we only add SIGs if we've added the type they cover, so
	 * we do not need to check if the SIG rdataset is already in the
	 * response.
	 */
	query_addrdataset(client, mname, rdataset);
	*rdatasetp = NULL;
	if (sigrdataset != NULL && dns_rdataset_isassociated(sigrdataset)) {
		/*
		 * We have a signature.  Add it to the response.
		 */
		ISC_LIST_APPEND(mname->list, sigrdataset, link);
		*sigrdatasetp = NULL;
	}
	CTRACE("query_addrrset: done");
}

static inline isc_result_t
query_addsoa(ns_client_t *client, dns_db_t *db, isc_boolean_t zero_ttl) {
	dns_name_t *name, *fname;
	dns_dbnode_t *node;
	isc_result_t result, eresult;
	dns_fixedname_t foundname;
	dns_rdataset_t *rdataset = NULL, *sigrdataset = NULL;
	dns_rdataset_t **sigrdatasetp = NULL;

	CTRACE("query_addsoa");
	/*
	 * Initialization.
	 */
	eresult = ISC_R_SUCCESS;
	name = NULL;
	rdataset = NULL;
	node = NULL;
	dns_fixedname_init(&foundname);
	fname = dns_fixedname_name(&foundname);

	/*
	 * Get resources and make 'name' be the database origin.
	 */
	result = dns_message_gettempname(client->message, &name);
	if (result != ISC_R_SUCCESS)
		return (result);
	dns_name_init(name, NULL);
	dns_name_clone(dns_db_origin(db), name);
	rdataset = query_newrdataset(client);
	if (rdataset == NULL) {
		eresult = DNS_R_SERVFAIL;
		goto cleanup;
	}
	if (WANTDNSSEC(client)) {
		sigrdataset = query_newrdataset(client);
		if (sigrdataset == NULL) {
			eresult = DNS_R_SERVFAIL;
			goto cleanup;
		}
	}

	/*
	 * Find the SOA.
	 */
	result = dns_db_find(db, name, NULL, dns_rdatatype_soa,
			     client->query.dboptions, 0, &node,
			     fname, rdataset, sigrdataset);
	if (result != ISC_R_SUCCESS) {
		/*
		 * This is bad.  We tried to get the SOA RR at the zone top
		 * and it didn't work!
		 */
		eresult = DNS_R_SERVFAIL;
	} else {
		/*
		 * Extract the SOA MINIMUM.
		 */
		dns_rdata_soa_t soa;
		dns_rdata_t rdata = DNS_RDATA_INIT;
		result = dns_rdataset_first(rdataset);
		RUNTIME_CHECK(result == ISC_R_SUCCESS);
		dns_rdataset_current(rdataset, &rdata);
		result = dns_rdata_tostruct(&rdata, &soa, NULL);
		if (result != ISC_R_SUCCESS)
			goto cleanup;

		if (zero_ttl) {
			rdataset->ttl = 0;
			if (sigrdataset != NULL)
				sigrdataset->ttl = 0;
		}

		/*
		 * Add the SOA and its SIG to the response, with the
		 * TTLs adjusted per RFC2308 section 3.
		 */
		if (rdataset->ttl > soa.minimum)
			rdataset->ttl = soa.minimum;
		if (sigrdataset != NULL && sigrdataset->ttl > soa.minimum)
			sigrdataset->ttl = soa.minimum;

		if (sigrdataset != NULL)
			sigrdatasetp = &sigrdataset;
		else
			sigrdatasetp = NULL;
		query_addrrset(client, &name, &rdataset, sigrdatasetp, NULL,
			       DNS_SECTION_AUTHORITY);
	}

 cleanup:
	query_putrdataset(client, &rdataset);
	if (sigrdataset != NULL)
		query_putrdataset(client, &sigrdataset);
	if (name != NULL)
		query_releasename(client, &name);
	if (node != NULL)
		dns_db_detachnode(db, &node);

	return (eresult);
}

static inline isc_result_t
query_addns(ns_client_t *client, dns_db_t *db) {
	dns_name_t *name, *fname;
	dns_dbnode_t *node;
	isc_result_t result, eresult;
	dns_fixedname_t foundname;
	dns_rdataset_t *rdataset = NULL, *sigrdataset = NULL;
	dns_rdataset_t **sigrdatasetp = NULL;

	CTRACE("query_addns");
	/*
	 * Initialization.
	 */
	eresult = ISC_R_SUCCESS;
	name = NULL;
	rdataset = NULL;
	node = NULL;
	dns_fixedname_init(&foundname);