Пример #1
0
static isc_result_t
addoptout(dns_message_t *message, dns_db_t *cache, dns_dbnode_t *node,
	  dns_rdatatype_t covers, isc_stdtime_t now, dns_ttl_t maxttl,
	  isc_boolean_t optout, isc_boolean_t secure,
	  dns_rdataset_t *addedrdataset)
{
	isc_result_t result;
	isc_buffer_t buffer;
	isc_region_t r;
	dns_rdataset_t *rdataset;
	dns_rdatatype_t type;
	dns_name_t *name;
	dns_ttl_t ttl;
	dns_trust_t trust;
	dns_rdata_t rdata[DNS_NCACHE_RDATA];
	dns_rdataset_t ncrdataset;
	dns_rdatalist_t ncrdatalist;
	unsigned char data[4096];
	unsigned int next = 0;

	/*
	 * Convert the authority data from 'message' into a negative cache
	 * rdataset, and store it in 'cache' at 'node'.
	 */

	REQUIRE(message != NULL);

	/*
	 * We assume that all data in the authority section has been
	 * validated by the caller.
	 */

	/*
	 * Initialize the list.
	 */
	dns_rdatalist_init(&ncrdatalist);
	ncrdatalist.rdclass = dns_db_class(cache);
	ncrdatalist.covers = covers;
	ncrdatalist.ttl = maxttl;

	/*
	 * Build an ncache rdatas into buffer.
	 */
	ttl = maxttl;
	trust = 0xffff;
	isc_buffer_init(&buffer, data, sizeof(data));
	if (message->counts[DNS_SECTION_AUTHORITY])
		result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
	else
		result = ISC_R_NOMORE;
	while (result == ISC_R_SUCCESS) {
		name = NULL;
		dns_message_currentname(message, DNS_SECTION_AUTHORITY,
					&name);
		if ((name->attributes & DNS_NAMEATTR_NCACHE) != 0) {
			for (rdataset = ISC_LIST_HEAD(name->list);
			     rdataset != NULL;
			     rdataset = ISC_LIST_NEXT(rdataset, link)) {
				if ((rdataset->attributes &
				     DNS_RDATASETATTR_NCACHE) == 0)
					continue;
				type = rdataset->type;
				if (type == dns_rdatatype_rrsig)
					type = rdataset->covers;
				if (type == dns_rdatatype_soa ||
				    type == dns_rdatatype_nsec ||
				    type == dns_rdatatype_nsec3) {
					if (ttl > rdataset->ttl)
						ttl = rdataset->ttl;
					if (trust > rdataset->trust)
						trust = rdataset->trust;
					/*
					 * Copy the owner name to the buffer.
					 */
					dns_name_toregion(name, &r);
					result = isc_buffer_copyregion(&buffer,
								       &r);
					if (result != ISC_R_SUCCESS)
						return (result);
					/*
					 * Copy the type to the buffer.
					 */
					isc_buffer_availableregion(&buffer,
								   &r);
					if (r.length < 3)
						return (ISC_R_NOSPACE);
					isc_buffer_putuint16(&buffer,
							     rdataset->type);
					isc_buffer_putuint8(&buffer,
					       (unsigned char)rdataset->trust);
					/*
					 * Copy the rdataset into the buffer.
					 */
					result = copy_rdataset(rdataset,
							       &buffer);
					if (result != ISC_R_SUCCESS)
						return (result);

					if (next >= DNS_NCACHE_RDATA)
						return (ISC_R_NOSPACE);
					dns_rdata_init(&rdata[next]);
					isc_buffer_remainingregion(&buffer, &r);
					rdata[next].data = r.base;
					rdata[next].length = r.length;
					rdata[next].rdclass =
						ncrdatalist.rdclass;
					rdata[next].type = 0;
					rdata[next].flags = 0;
					ISC_LIST_APPEND(ncrdatalist.rdata,
							&rdata[next], link);
					isc_buffer_forward(&buffer, r.length);
					next++;
				}
			}
		}
		result = dns_message_nextname(message, DNS_SECTION_AUTHORITY);
	}
	if (result != ISC_R_NOMORE)
		return (result);

	if (trust == 0xffff) {
		if ((message->flags & DNS_MESSAGEFLAG_AA) != 0 &&
		    message->counts[DNS_SECTION_ANSWER] == 0) {
			/*
			 * The response has aa set and we haven't followed
			 * any CNAME or DNAME chains.
			 */
			trust = dns_trust_authauthority;
		} else
			trust = dns_trust_additional;
		ttl = 0;
	}

	INSIST(trust != 0xffff);

	ncrdatalist.ttl = ttl;

	dns_rdataset_init(&ncrdataset);
	RUNTIME_CHECK(dns_rdatalist_tordataset(&ncrdatalist, &ncrdataset)
		      == ISC_R_SUCCESS);
	if (!secure && trust > dns_trust_answer)
		trust = dns_trust_answer;
	ncrdataset.trust = trust;
	ncrdataset.attributes |= DNS_RDATASETATTR_NEGATIVE;
	if (message->rcode == dns_rcode_nxdomain)
		ncrdataset.attributes |= DNS_RDATASETATTR_NXDOMAIN;
	if (optout)
		ncrdataset.attributes |= DNS_RDATASETATTR_OPTOUT;

	return (dns_db_addrdataset(cache, node, NULL, now, &ncrdataset,
				   0, addedrdataset));
}
Пример #2
0
isc_result_t
dns_ncache_add(dns_message_t *message, dns_db_t *cache, dns_dbnode_t *node,
	       dns_rdatatype_t covers, isc_stdtime_t now, dns_ttl_t maxttl,
	       dns_rdataset_t *addedrdataset)
{
	isc_result_t result;
	isc_buffer_t buffer;
	isc_region_t r;
	dns_rdataset_t *rdataset;
	dns_rdatatype_t type;
	dns_name_t *name;
	dns_ttl_t ttl;
	dns_trust_t trust;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	dns_rdataset_t ncrdataset;
	dns_rdatalist_t ncrdatalist;
	unsigned char data[4096];

	/*
	 * Convert the authority data from 'message' into a negative cache
	 * rdataset, and store it in 'cache' at 'node'.
	 */

	REQUIRE(message != NULL);

	/*
	 * We assume that all data in the authority section has been
	 * validated by the caller.
	 */

	/*
	 * First, build an ncache rdata in buffer.
	 */
	ttl = maxttl;
	trust = 0xffff;
	isc_buffer_init(&buffer, data, sizeof(data));
	if (message->counts[DNS_SECTION_AUTHORITY])
		result = dns_message_firstname(message, DNS_SECTION_AUTHORITY);
	else
		result = ISC_R_NOMORE;
	while (result == ISC_R_SUCCESS) {
		name = NULL;
		dns_message_currentname(message, DNS_SECTION_AUTHORITY,
					&name);
		if ((name->attributes & DNS_NAMEATTR_NCACHE) != 0) {
			for (rdataset = ISC_LIST_HEAD(name->list);
			     rdataset != NULL;
			     rdataset = ISC_LIST_NEXT(rdataset, link)) {
				if ((rdataset->attributes &
				     DNS_RDATASETATTR_NCACHE) == 0)
					continue;
				type = rdataset->type;
				if (type == dns_rdatatype_rrsig)
					type = rdataset->covers;
				if (type == dns_rdatatype_soa ||
				    type == dns_rdatatype_nsec) {
					if (ttl > rdataset->ttl)
						ttl = rdataset->ttl;
					if (trust > rdataset->trust)
						trust = rdataset->trust;
					/*
					 * Copy the owner name to the buffer.
					 */
					dns_name_toregion(name, &r);
					result = isc_buffer_copyregion(&buffer,
								       &r);
					if (result != ISC_R_SUCCESS)
						return (result);
					/*
					 * Copy the type to the buffer.
					 */
					isc_buffer_availableregion(&buffer,
								   &r);
					if (r.length < 2)
						return (ISC_R_NOSPACE);
					isc_buffer_putuint16(&buffer,
							     rdataset->type);
					/*
					 * Copy the rdataset into the buffer.
					 */
					result = copy_rdataset(rdataset,
							       &buffer);
					if (result != ISC_R_SUCCESS)
						return (result);
				}
			}
		}
		result = dns_message_nextname(message, DNS_SECTION_AUTHORITY);
	}
	if (result != ISC_R_NOMORE)
		return (result);

	if (trust == 0xffff) {
		/*
		 * We didn't find any authority data from which to create a
		 * negative cache rdataset.  In particular, we have no SOA.
		 *
		 * We trust that the caller wants negative caching, so this
		 * means we have a "type 3 nxdomain" or "type 3 nodata"
		 * response (see RFC 2308 for details).
		 *
		 * We will now build a suitable negative cache rdataset that
		 * will cause zero bytes to be emitted when converted to
		 * wire format.
		 */

		/*
		 * The ownername must exist, but it doesn't matter what value
		 * it has.  We use the root name.
		 */
		dns_name_toregion(dns_rootname, &r);
		result = isc_buffer_copyregion(&buffer, &r);
		if (result != ISC_R_SUCCESS)
			return (result);
		/*
		 * Copy the type and a zero rdata count to the buffer.
		 */
		isc_buffer_availableregion(&buffer, &r);
		if (r.length < 4)
			return (ISC_R_NOSPACE);
		isc_buffer_putuint16(&buffer, 0);
		isc_buffer_putuint16(&buffer, 0);
		/*
		 * RFC 2308, section 5, says that negative answers without
		 * SOAs should not be cached.
		 */
		ttl = 0;
		/*
		 * Set trust.
		 */
		if ((message->flags & DNS_MESSAGEFLAG_AA) != 0 &&
		    message->counts[DNS_SECTION_ANSWER] == 0) {
			/*
			 * The response has aa set and we haven't followed
			 * any CNAME or DNAME chains.
			 */
			trust = dns_trust_authauthority;
		} else
			trust = dns_trust_additional;
	}

	/*
	 * Now add it to the cache.
	 */
	INSIST(trust != 0xffff);
	isc_buffer_usedregion(&buffer, &r);
	rdata.data = r.base;
	rdata.length = r.length;
	rdata.rdclass = dns_db_class(cache);
	rdata.type = 0;
	rdata.flags = 0;

	ncrdatalist.rdclass = rdata.rdclass;
	ncrdatalist.type = 0;
	ncrdatalist.covers = covers;
	ncrdatalist.ttl = ttl;
	ISC_LIST_INIT(ncrdatalist.rdata);
	ISC_LINK_INIT(&ncrdatalist, link);

	ISC_LIST_APPEND(ncrdatalist.rdata, &rdata, link);

	dns_rdataset_init(&ncrdataset);
	RUNTIME_CHECK(dns_rdatalist_tordataset(&ncrdatalist, &ncrdataset)
		      == ISC_R_SUCCESS);
	ncrdataset.trust = trust;
	if (message->rcode == dns_rcode_nxdomain)
		ncrdataset.attributes |= DNS_RDATASETATTR_NXDOMAIN;

	return (dns_db_addrdataset(cache, node, NULL, now, &ncrdataset,
				   0, addedrdataset));
}