ext-rcode: Review fixes

src/knot/nameserver/internet.c

@@ -119,8 +119,8 @@ static bool dname_cname_cannot_synth(const knot_rrset_t *rrset, const knot_dname
 /*! \brief DNSSEC both requested & available. */
 static bool have_dnssec(struct query_data *qdata)
 {
+	assert(qdata->rcode == KNOT_RCODE_NOERROR);
 	return knot_pkt_has_dnssec(qdata->query) &&
-	       qdata->rcode != KNOT_RCODE_BADVERS &&
 	       zone_contents_is_signed(qdata->zone->contents);
 }
 

src/knot/nameserver/process_query.c

@@ -267,8 +267,8 @@ static int answer_edns_put(knot_pkt_t *resp, struct query_data *qdata)
 	assert(resp->current == KNOT_ADDITIONAL);
 	ret = knot_pkt_put(resp, KNOT_COMPR_HINT_NONE, &qdata->opt_rr, 0);
 	if (ret == KNOT_EOK) {
-		/* Save position of the Ext RCODE field. */
-		qdata->ext_rcode = wire_end + KNOT_EDNS_EXT_RCODE_POS;
+		/* Save position of the OPT RR. */
+		qdata->opt_rr_pos = wire_end;
 	}
 
 	return ret;
@@ -337,13 +337,13 @@ static int set_rcode_to_packet(knot_pkt_t *pkt, struct query_data *qdata)
 
 	if (ext_rcode != 0) {
 		/* If there is no OPT RR and Ext RCODE is set, result in
-		 * SERVFAIL. This should not happen!
+		 * SERVFAIL. This may happen if adding OPT failed.
 		 */
-		if (qdata->ext_rcode == NULL) {
+		if (qdata->opt_rr_pos == NULL) {
 			qdata->rcode = KNOT_RCODE_SERVFAIL;
 			ret = KNOT_ERROR;
 		} else {
-			*qdata->ext_rcode = ext_rcode;
+			knot_edns_set_ext_rcode_wire(qdata->opt_rr_pos, ext_rcode);
 		}
 	}
 
@@ -373,14 +373,12 @@ static int process_query_err(knot_layer_t *ctx, knot_pkt_t *pkt)
 	}
 
 	/* Put OPT RR to the additional section. */
-	int ret = answer_edns_reserve(pkt, qdata);
-	ret = ret || answer_edns_put(pkt, qdata);
-
-	if (ret != KNOT_EOK) {
-		qdata->rcode = KNOT_RCODE_SERVFAIL;
+	ret = answer_edns_reserve(pkt, qdata);
+	if (ret == KNOT_EOK) {
+		(void) answer_edns_put(pkt, qdata);
 	}
 
-	/* Set final RCODE to packet. */
+	/* Set final RCODE to packet. If the above failed, SERVFAIL will be set. */
 	(void) set_rcode_to_packet(pkt, qdata);
 
 	/* Transaction security (if applicable). */

src/knot/nameserver/process_query.h

@@ -69,7 +69,6 @@ struct process_query_param {
 /*! \brief Query processing intermediate data. */
 struct query_data {
 	uint16_t rcode;       /*!< Resulting RCODE (Whole extended RCODE). */
-	uint8_t *ext_rcode;   /*!< Place of the Ext RCODE field of OPT RR in wire. */
 	uint16_t rcode_tsig;  /*!< Resulting TSIG RCODE. */
 	uint16_t packet_type; /*!< Resolved packet type. */
 	knot_pkt_t *query;    /*!< Query to be solved. */
@@ -86,6 +85,7 @@ struct query_data {
 
 	/* EDNS */
 	knot_rrset_t opt_rr;
+	uint8_t *opt_rr_pos;  /*!< Place of the OPT RR in wire. */
 
 	/* Extensions. */
 	void *ext;

src/libknot/rrtype/opt.h

@@ -171,6 +171,17 @@ static inline uint16_t knot_edns_whole_rcode(uint8_t ext_rcode, uint8_t rcode)
  */
 void knot_edns_set_ext_rcode(knot_rrset_t *opt_rr, uint8_t ext_rcode);
 
+/*!
+ * \brief Sets the Extended RCODE field in OPT RR wire.
+ *
+ * \param opt_rr     Position of the OPT RR in packet.
+ * \param ext_rcode  Higher 8 bits of Extended RCODE.
+ */
+inline void knot_edns_set_ext_rcode_wire(uint8_t *opt_rr, uint8_t ext_rcode)
+{
+	*(opt_rr + KNOT_EDNS_EXT_RCODE_POS) = ext_rcode;
+}
+
 /*!
  * \brief Returns the EDNS version stored in the OPT RR.
  *