First draft of NOTIFY support functions.

Knot.files

@@ -148,6 +148,8 @@ src/knot/server/zones.c
 src/knot/server/zones.h
 src/knot/server/axfr-in.c
 src/knot/server/axfr-in.h
+src/knot/server/notify.c
+src/knot/server/notify.h
 src/knot/ctl/process.c
 src/knot/ctl/process.h
 src/knot/conf/cf-lex.l

src/knot/server/notify.c

+#include <assert.h>
+
+#include "knot/server/notify.h"
+
+#include "dnslib/dname.h"
+#include "dnslib/packet.h"
+#include "dnslib/rrset.h"
+#include "dnslib/response2.h"
+#include "dnslib/query.h"
+#include "dnslib/consts.h"
+#include "knot/other/error.h"
+#include "dnslib/zonedb.h"
+
+/*----------------------------------------------------------------------------*/
+/* Non-API functions                                                          */
+/*----------------------------------------------------------------------------*/
+
+static int notify_request(const dnslib_rrset_t *rrset,
+                          uint8_t *buffer, size_t *size)
+{
+	dnslib_packet_t *pkt = dnslib_packet_new(DNSLIB_PACKET_PREALLOC_QUERY);
+	CHECK_ALLOC_LOG(pkt, KNOT_ENOMEM);
+
+	/*! \todo Get rid of the numeric constant. */
+	int rc = dnslib_packet_set_max_size(pkt, 512);
+	if (rc != DNSLIB_EOK) {
+		dnslib_packet_free(&pkt);
+		return rc;
+	}
+
+	rc = dnslib_query_init(pkt);
+	if (rc != DNSLIB_EOK) {
+		dnslib_packet_free(&pkt);
+		return rc;
+	}
+
+	dnslib_question_t question;
+
+	// this is ugly!!
+	question.qname = rrset->owner;
+	question.qtype = rrset->type;
+	question.qclass = rrset->rclass;
+
+	rc = dnslib_query_set_question(pkt, &question);
+	if (rc != DNSLIB_EOK) {
+		dnslib_packet_free(&pkt);
+		return rc;
+	}
+
+	/*! \todo Set some random ID!! */
+
+	/*! \todo add the SOA RR to the Answer section as a hint */
+	/*! \todo this should not use response API!! */
+//	rc = dnslib_response2_add_rrset_answer(pkt, rrset, 0, 0, 0);
+//	if (rc != DNSLIB_EOK) {
+//		dnslib_packet_free(&pkt);
+//		return rc;
+//	}
+
+	/*! \todo this should not use response API!! */
+	dnslib_response2_set_aa(pkt);
+
+	dnslib_query_set_opcode(pkt, DNSLIB_OPCODE_NOTIFY);
+
+	/*! \todo OPT RR ?? */
+
+	uint8_t *wire = NULL;
+	size_t wire_size = 0;
+	rc = dnslib_packet_to_wire(pkt, &wire, &wire_size);
+	if (rc != DNSLIB_EOK) {
+		dnslib_packet_free(&pkt);
+		return rc;
+	}
+
+	if (wire_size > *size) {
+		log_answer_warning("Not enough space provided for the wire "
+		                   "format of the query.\n");
+		dnslib_packet_free(&pkt);
+		return KNOT_ESPACE;
+	}
+
+	memcpy(buffer, wire, wire_size);
+	*size = wire_size;
+
+	debug_ns("Created query of size %zu.\n", *size);
+	dnslib_packet_dump(pkt);
+
+	dnslib_packet_free(&pkt);
+
+	return KNOT_EOK;
+}
+
+/*----------------------------------------------------------------------------*/
+
+int notify_create_response(dnslib_packet_t *request, uint8_t *buffer,
+                           size_t *size)
+{
+	dnslib_packet_t *response =
+		dnslib_packet_new(DNSLIB_PACKET_PREALLOC_QUERY);
+	CHECK_ALLOC_LOG(response, KNOT_ENOMEM);
+
+	dnslib_response2_init_from_query(response, request);
+
+	// TODO: copy the SOA in Answer section
+
+	uint8_t *wire = NULL;
+	size_t wire_size = 0;
+	rc = dnslib_packet_to_wire(response, &wire, &wire_size);
+	if (rc != DNSLIB_EOK) {
+		dnslib_packet_free(&response);
+		return rc;
+	}
+
+	if (wire_size > *size) {
+		log_answer_warning("Not enough space provided for the wire "
+		                   "format of the query.\n");
+		dnslib_packet_free(&response);
+		return KNOT_ESPACE;
+	}
+
+	memcpy(buffer, wire, wire_size);
+	*size = wire_size;
+
+	debug_ns("Created query of size %zu.\n", *size);
+	dnslib_packet_dump(response);
+
+	dnslib_packet_free(&response);
+
+	return KNOT_EOK;
+}
+
+/*----------------------------------------------------------------------------*/
+/* API functions                                                              */
+/*----------------------------------------------------------------------------*/
+
+int notify_create_request(const dnslib_zone_t *zone, uint8_t *buffer,
+                          size_t *size)
+{
+	dnslib_rrset_t *soa_rrset =
+		dnslib_node_rrset(dnslib_zone_apex(zone), DNSLIB_RRTYPE_SOA);
+	if (soa_rrset == NULL) {
+		return KNOT_ERROR;
+	}
+
+	return notify_request(soa_rrset, buffer, size);
+}
+
+/*----------------------------------------------------------------------------*/
+
+int notify_process_request(dnslib_packet_t *notify,
+                           const dnslib_zonedb_t *zonedb,
+                           const dnslib_zone_t **zone,
+                           uint8_t *buffer, size_t *size)
+{
+	/*! \todo Most of this function is identical to axfrin_transfer_needed()
+	 *        - it will be fine to merge the code somehow.
+	 */
+
+	if (notify == NULL || zone == NULL || buffer == NULL || size == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	*zone = NULL;
+
+	debug_ns("Notify request - parsed: %zu, total wire size: %zu\n",
+	         notify->parsed, notify->size);
+	int ret;
+
+	if (notify->parsed < notify->size) {
+		ret = dnslib_packet_parse_rest(notify);
+		if (ret != DNSLIB_EOK) {
+			return KNOT_EMALF;
+		}
+	}
+
+	// create NOTIFY response
+	ret = notify_create_response(notify, buffer, size);
+	if (ret != KNOT_EOK) {
+		return KNOT_ERROR;	/*! \todo Some other error. */
+	}
+
+	// find the zone
+	dnslib_dname_t *qname = dnslib_packet_qname(notify);
+	*zone = dnslib_zonedb_find_zone_for_name(zonedb, qname);
+	if (*zone == NULL) {
+		return KNOT_ERROR;	/*! \todo Some other error. */
+	}
+
+	// check if the zone needs an update
+	dnslib_rrset_t *soa_rrset = dnslib_node_rrset(dnslib_zone_apex(*zone),
+	                                              DNSLIB_RRTYPE_SOA);
+	if (soa_rrset == NULL) {
+		char *name = dnslib_dname_to_str(dnslib_rrset_owner(soa_rrset));
+		log_answer_warning("SOA RRSet missing in the zone %s!\n", name);
+		free(name);
+		return KNOT_ERROR;	/*! \todo Some other error. */
+	}
+
+	/*
+	 * Retrieve the local Serial
+	 */
+	const dnslib_rrset_t *soa_rrset =
+		dnslib_node_rrset(dnslib_zone_apex(zone), DNSLIB_RRTYPE_SOA);
+	if (soa_rrset == NULL) {
+		char *name = dnslib_dname_to_str(dnslib_node_owner(
+				dnslib_zone_apex(zone)));
+		log_answer_warning("SOA RRSet missing in the zone %s!\n", name);
+		free(name);
+		return KNOT_ERROR;
+	}
+
+	int64_t local_serial = dnslib_rdata_soa_serial(
+		dnslib_rrset_rdata(soa_rrset));
+	if (local_serial < 0) {
+		char *name = dnslib_dname_to_str(dnslib_rrset_owner(soa_rrset));
+		log_answer_warning("Malformed data in SOA of zone %s\n", name);
+		free(name);
+		return KNOT_EMALF;	// maybe some other error
+	}
+
+	/*
+	 * Retrieve the remote Serial
+	 */
+	// the SOA should be the first (and only) RRSet in the response
+	soa_rrset = dnslib_packet_answer_rrset(notify, 0);
+	if (soa_rrset == NULL
+	    || dnslib_rrset_type(soa_rrset) != DNSLIB_RRTYPE_SOA) {
+		return KNOT_EMALF;
+	}
+
+	int64_t remote_serial = dnslib_rdata_soa_serial(
+		dnslib_rrset_rdata(soa_rrset));
+	if (remote_serial < 0) {
+		return KNOT_EMALF;	// maybe some other error
+	}
+
+	// if the Serials are identical, no transfer is needed
+	if (local_serial == remote_serial) {
+		*zone = NULL;
+	}
+
+	return KNOT_EOK;
+}
+
+/*----------------------------------------------------------------------------*/
+
+int notify_process_response(const dnslib_zone_t *zone, dnslib_packet_t *notify)
+{
+	return KNOT_ENOTSUP;
+}
+

src/knot/server/notify.h

+/*!
+ * \file notify.h
+ *
+ * \author Lubos Slovak <lubos.slovak@nic.cz>
+ *
+ * \brief NOTIFY request/reply API.
+ *
+ * \addtogroup query_processing
+ * @{
+ */
+
+#ifndef _KNOT_NOTIFY_H_
+#define _KNOT_NOTIFY_H_
+
+#include <stdint.h>
+#include <string.h>
+
+#include "dnslib/zone.h"
+#include "dnslib/packet.h"
+#include "dnslib/zonedb.h"
+
+int notify_create_request(const dnslib_zone_t *zone, uint8_t *buffer,
+                          size_t *size);
+
+int notify_process_request(dnslib_packet_t *notify,
+                           const dnslib_zonedb_t *zonedb,
+                           const dnslib_zone_t **zone,
+                           uint8_t *buffer, size_t *size);
+
+int notify_process_response(const dnslib_zone_t *zone, dnslib_packet_t *notify);
+
+#endif /* _KNOT_NOTIFY_H_ */
+
+/*! @} */