Fix: EDNS should not apply for TCP queries.

refs #1828 @2h

6 files changed, 28 insertions, 14 deletions

diff --git a/src/knot/server/tcp-handler.c b/src/knot/server/tcp-handler.c
index e53e28695..5f79096b5 100644
--- a/src/knot/server/tcp-handler.c
+++ b/src/knot/server/tcp-handler.c
@@ -207,7 +207,8 @@ static int tcp_handle(tcp_worker_t *w, int fd, uint8_t *qbuf, size_t qbuf_maxlen
 	case KNOT_QUERY_NORMAL:
 		//res = knot_ns_answer_normal(ns, packet, qbuf, &resp_len);
 		if (zones_normal_query_answer(ns, packet, &addr,
-		                              qbuf, &resp_len) == KNOT_EOK) {
+		                              qbuf, &resp_len,
+		                              NS_TRANSPORT_TCP) == KNOT_EOK) {
 			res = KNOTD_EOK;
 		}
 		break;
diff --git a/src/knot/server/udp-handler.c b/src/knot/server/udp-handler.c
index 73c557d01..80bc011d7 100644
--- a/src/knot/server/udp-handler.c
+++ b/src/knot/server/udp-handler.c
@@ -122,7 +122,7 @@ int udp_handle(int fd, uint8_t *qbuf, size_t qbuflen, size_t *resp_len,
 	/* Query types. */
 	case KNOT_QUERY_NORMAL:
 		res = zones_normal_query_answer(ns, packet, addr, qbuf,
-		                                resp_len);
+		                                resp_len, NS_TRANSPORT_UDP);
 //		res = knot_ns_answer_normal(ns, packet, qbuf,
 //					      resp_len);
 		break;
@@ -144,7 +144,8 @@ int udp_handle(int fd, uint8_t *qbuf, size_t qbuflen, size_t *resp_len,
 		 */
 		knot_packet_set_qtype(packet, KNOT_RRTYPE_SOA);
 		res = zones_normal_query_answer(ns, packet, addr,
-		                                qbuf, resp_len);
+		                                qbuf, resp_len, 
+		                                NS_TRANSPORT_UDP);
 //		res = knot_ns_answer_normal(ns, packet, qbuf,
 //		                            resp_len);
 		break;
diff --git a/src/knot/server/zones.c b/src/knot/server/zones.c
index ba6340d10..8ef605d75 100644
--- a/src/knot/server/zones.c
+++ b/src/knot/server/zones.c
@@ -1978,7 +1978,8 @@ int zones_xfr_check_zone(knot_ns_xfr_t *xfr, knot_rcode_t *rcode)
 
 int zones_normal_query_answer(knot_nameserver_t *nameserver,
                               knot_packet_t *query, const sockaddr_t *addr,
-                              uint8_t *resp_wire, size_t *rsize)
+                              uint8_t *resp_wire, size_t *rsize,
+                              knot_ns_transport_t transport)
 {
 	rcu_read_lock();
 
@@ -1986,7 +1987,9 @@ int zones_normal_query_answer(knot_nameserver_t *nameserver,
 	const knot_zone_t *zone = NULL;
 
 	dbg_zones_verb("Preparing response structure.\n");
-	int ret = knot_ns_prep_normal_response(nameserver, query, &resp, &zone);
+	int ret = knot_ns_prep_normal_response(nameserver, query, &resp, &zone,
+	                                       (transport == NS_TRANSPORT_TCP)
+	                                       ? *rsize : 0);
 
 	// check for TSIG in the query
 	if (knot_packet_additional_rrset_count(query) > 0) {
diff --git a/src/knot/server/zones.h b/src/knot/server/zones.h
index 08f9df6db..bb95b9340 100644
--- a/src/knot/server/zones.h
+++ b/src/knot/server/zones.h
@@ -151,7 +151,8 @@ int zones_xfr_check_zone(knot_ns_xfr_t *xfr, knot_rcode_t *rcode);
  */
 int zones_normal_query_answer(knot_nameserver_t *nameserver,
                               knot_packet_t *query, const sockaddr_t *addr,
-                              uint8_t *response_wire, size_t *rsize);
+                              uint8_t *response_wire, size_t *rsize,
+                              knot_ns_transport_t transport);
 
 /*!
  * \brief Processes normal response packet.
diff --git a/src/libknot/nameserver/name-server.c b/src/libknot/nameserver/name-server.c
index e1ccdd4de..213534c38 100644
--- a/src/libknot/nameserver/name-server.c
+++ b/src/libknot/nameserver/name-server.c
@@ -2877,7 +2877,7 @@ void knot_ns_error_response_full(knot_nameserver_t *nameserver,
 
 int knot_ns_prep_normal_response(knot_nameserver_t *nameserver,
                                  knot_packet_t *query, knot_packet_t **resp,
-                                 const knot_zone_t **zone)
+                                 const knot_zone_t **zone, size_t max_size)
 {
 	dbg_ns("knot_ns_prep_normal_response()\n");
 
@@ -2894,8 +2894,8 @@ int knot_ns_prep_normal_response(knot_nameserver_t *nameserver,
 
 	ret = knot_packet_parse_rest(query);
 	if (ret != KNOT_EOK) {
-		dbg_ns("Failed to parse rest of the query: "
-				   "%s.\n", knot_strerror(ret));
+		dbg_ns("Failed to parse rest of the query: %s.\n",
+		       knot_strerror(ret));
 		return ret;
 	}
 
@@ -2917,11 +2917,14 @@ int knot_ns_prep_normal_response(knot_nameserver_t *nameserver,
 
 	size_t resp_max_size = 0;
 
-	//assert(*rsize >= MAX_UDP_PAYLOAD);
-
 	knot_packet_dump(query);
-
-	if (knot_query_edns_supported(query)) {
+	
+	if (max_size > 0) {
+		// if TCP is used, buffer size is the only constraint
+		assert(max_size > 0);
+		resp_max_size = max_size;
+	} else if (knot_query_edns_supported(query)) {
+		assert(max_size == 0);
 		if (knot_edns_get_payload(&query->opt_rr) <
 		    knot_edns_get_payload(nameserver->opt_rr)) {
 			resp_max_size = knot_edns_get_payload(&query->opt_rr);
diff --git a/src/libknot/nameserver/name-server.h b/src/libknot/nameserver/name-server.h
index 42fa0f260..d40a7d92c 100644
--- a/src/libknot/nameserver/name-server.h
+++ b/src/libknot/nameserver/name-server.h
@@ -157,6 +157,11 @@ enum knot_ns_xfr_flag_t {
 	XFR_FLAG_AXFR_FINISHED = 1 << 2
 };
 
+typedef enum knot_ns_transport {
+	NS_TRANSPORT_UDP = 1 << 0,
+	NS_TRANSPORT_TCP = 1 << 1
+} knot_ns_transport_t;
+
 /*!
  * \brief XFR request types.
  */
@@ -235,7 +240,7 @@ void knot_ns_error_response_full(knot_nameserver_t *nameserver,
 
 int knot_ns_prep_normal_response(knot_nameserver_t *nameserver,
                                  knot_packet_t *query, knot_packet_t **resp,
-                                 const knot_zone_t **zone);
+                                 const knot_zone_t **zone, size_t max_size);
 
 /*!
  * \brief Creates a response for the given normal query using the data of the