1 files changed, 85 insertions, 0 deletions
diff --git a/src/knot/query/query.c b/src/knot/query/query.c
new file mode 100644
index 0000000..877851a
--- /dev/null
+++ b/src/knot/query/query.c
@@ -0,0 +1,85 @@
+/*  Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "knot/query/query.h"
+
+#include "contrib/wire_ctx.h"
+#include "libdnssec/random.h"
+
+void query_init_pkt(knot_pkt_t *pkt)
+{
+	if (pkt == NULL) {
+		return;
+	}
+
+	knot_pkt_clear(pkt);
+	knot_wire_set_id(pkt->wire, dnssec_random_uint16_t());
+}
+
+query_edns_data_t query_edns_data_init(conf_t *conf, int remote_family,
+                                       query_edns_opt_t opts)
+{
+	assert(conf);
+
+	query_edns_data_t edns = {
+		.max_payload = remote_family == AF_INET ?
+		               conf->cache.srv_udp_max_payload_ipv4 :
+		               conf->cache.srv_udp_max_payload_ipv6,
+		.do_flag = (opts & QUERY_EDNS_OPT_DO),
+		.expire_option = (opts & QUERY_EDNS_OPT_EXPIRE)
+	};
+
+	return edns;
+}
+
+int query_put_edns(knot_pkt_t *pkt, const query_edns_data_t *edns)
+{
+	if (!pkt || !edns) {
+		return KNOT_EINVAL;
+	}
+
+	// Construct EDNS RR
+
+	knot_rrset_t opt_rr = { 0 };
+	int ret = knot_edns_init(&opt_rr, edns->max_payload, 0, KNOT_EDNS_VERSION, &pkt->mm);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	if (edns->do_flag) {
+		knot_edns_set_do(&opt_rr);
+	}
+
+	if (edns->expire_option) {
+		ret = knot_edns_add_option(&opt_rr, KNOT_EDNS_OPTION_EXPIRE, 0, NULL, &pkt->mm);
+		if (ret != KNOT_EOK) {
+			knot_rrset_clear(&opt_rr, &pkt->mm);
+			return ret;
+		}
+	}
+
+	// Add result into the packet
+
+	knot_pkt_begin(pkt, KNOT_ADDITIONAL);
+
+	ret = knot_pkt_put(pkt, KNOT_COMPR_HINT_NOCOMP, &opt_rr, KNOT_PF_FREE);
+	if (ret != KNOT_EOK) {
+		knot_rrset_clear(&opt_rr, &pkt->mm);
+		return ret;
+	}
+
+	return KNOT_EOK;
+}