Adding upstream version 3.2.6.upstream/3.2.6upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 4302 insertions, 0 deletions

diff --git a/src/utils/kdig/kdig_exec.c b/src/utils/kdig/kdig_exec.c
new file mode 100644
index 0000000..391e674
--- /dev/null
+++ b/src/utils/kdig/kdig_exec.c
@@ -0,0 +1,1309 @@
+/*  Copyright (C) 2023 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 <stdlib.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+
+#include "utils/kdig/kdig_exec.h"
+#include "utils/common/exec.h"
+#include "utils/common/msg.h"
+#include "utils/common/netio.h"
+#include "utils/common/sign.h"
+#include "libknot/libknot.h"
+#include "contrib/json.h"
+#include "contrib/sockaddr.h"
+#include "contrib/time.h"
+#include "contrib/ucw/lists.h"
+
+#if USE_DNSTAP
+# include "contrib/dnstap/convert.h"
+# include "contrib/dnstap/message.h"
+# include "contrib/dnstap/writer.h"
+
+static int write_dnstap(dt_writer_t           *writer,
+                        const bool            is_query,
+                        const uint8_t         *wire,
+                        const size_t          wire_len,
+                        net_t                 *net,
+                        const struct timespec *mtime)
+{
+	Dnstap__Message       msg;
+	Dnstap__Message__Type msg_type;
+	int                   ret;
+	int                   protocol = 0;
+
+	if (writer == NULL) {
+		return KNOT_EOK;
+	}
+
+	if (net->local == NULL) {
+		net_set_local_info(net);
+	}
+
+	msg_type = is_query ? DNSTAP__MESSAGE__TYPE__TOOL_QUERY :
+	                      DNSTAP__MESSAGE__TYPE__TOOL_RESPONSE;
+
+	if (net->socktype == SOCK_DGRAM) {
+		protocol = IPPROTO_UDP;
+	} else if (net->socktype == SOCK_STREAM) {
+		protocol = IPPROTO_TCP;
+	}
+
+	ret = dt_message_fill(&msg, msg_type, net->local_info->ai_addr,
+	                      net->srv->ai_addr, protocol,
+	                      wire, wire_len, mtime);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	return dt_writer_write(writer, (const ProtobufCMessage *)&msg);
+}
+
+static float get_query_time(const Dnstap__Dnstap *frame)
+{
+	if (!frame->message->has_query_time_sec ||
+	    !frame->message->has_query_time_nsec ||
+	    !frame->message->has_response_time_sec ||
+	    !frame->message->has_response_time_sec) {
+		return 0;
+	}
+
+	struct timespec from = {
+		.tv_sec = frame->message->query_time_sec,
+		.tv_nsec = frame->message->query_time_nsec
+	};
+
+	struct timespec to = {
+		.tv_sec = frame->message->response_time_sec,
+		.tv_nsec = frame->message->response_time_nsec
+	};
+
+	return time_diff_ms(&from, &to);
+}
+
+static void fill_remote_addr(net_t *net, Dnstap__Message *message, bool is_initiator)
+{
+	if (!message->has_socket_family || !message->has_socket_protocol) {
+		return;
+	}
+
+	if ((message->response_address.data == NULL && is_initiator) ||
+	     message->query_address.data == NULL) {
+		return;
+	}
+
+	struct sockaddr_storage ss = { 0 };
+	int family = dt_family_decode(message->socket_family);
+	int proto = dt_protocol_decode(message->socket_protocol);
+	int sock_type = 0;
+
+	switch (proto) {
+	case IPPROTO_TCP:
+		sock_type = SOCK_STREAM;
+		break;
+	case IPPROTO_UDP:
+		sock_type = SOCK_DGRAM;
+		break;
+	default:
+		break;
+	}
+
+	ProtobufCBinaryData *addr = NULL;
+	uint32_t port = 0;
+	if (is_initiator) {
+		addr = &message->response_address;
+		port = message->response_port;
+	} else {
+		addr = &message->query_address;
+		port = message->query_port;
+	}
+
+	sockaddr_set_raw(&ss, family, addr->data, addr->len);
+	sockaddr_port_set(&ss, port);
+
+	get_addr_str(&ss, sock_type, &net->remote_str);
+}
+
+static int process_dnstap(const query_t *query)
+{
+	dt_reader_t *reader = query->dt_reader;
+
+	if (query->dt_reader == NULL) {
+		return -1;
+	}
+
+	bool first_message = true;
+
+	for (;;) {
+		Dnstap__Dnstap      *frame = NULL;
+		Dnstap__Message     *message = NULL;
+		ProtobufCBinaryData *wire = NULL;
+		bool                is_query;
+		bool                is_initiator;
+
+		// Read next message.
+		int ret = dt_reader_read(reader, &frame);
+		if (ret == KNOT_EOF) {
+			break;
+		} else if (ret != KNOT_EOK) {
+			ERR("can't read dnstap message");
+			break;
+		}
+
+		// Check for dnstap message.
+		if (frame->type == DNSTAP__DNSTAP__TYPE__MESSAGE) {
+			message = frame->message;
+		} else {
+			WARN("ignoring non-dnstap message");
+			dt_reader_free_frame(reader, &frame);
+			continue;
+		}
+
+		// Check for the type of dnstap message.
+		if (message->has_response_message) {
+			wire = &message->response_message;
+			is_query = false;
+		} else if (message->has_query_message) {
+			wire = &message->query_message;
+			is_query = true;
+		} else {
+			WARN("dnstap frame contains no message");
+			dt_reader_free_frame(reader, &frame);
+			continue;
+		}
+
+		// Ignore query message if requested.
+		if (is_query && !query->style.show_query) {
+			dt_reader_free_frame(reader, &frame);
+			continue;
+		}
+
+		// Get the message role.
+		is_initiator = dt_message_role_is_initiator(message->type);
+
+		// Create dns packet based on dnstap wire data.
+		knot_pkt_t *pkt = knot_pkt_new(wire->data, wire->len, NULL);
+		if (pkt == NULL) {
+			ERR("can't allocate packet");
+			dt_reader_free_frame(reader, &frame);
+			break;
+		}
+
+		// Parse packet and reconstruct required data.
+		ret = knot_pkt_parse(pkt, KNOT_PF_NOCANON);
+		if (ret == KNOT_EOK || ret == KNOT_ETRAIL) {
+			time_t timestamp = 0;
+			float  query_time = 0.0;
+			net_t  net_ctx = { 0 };
+
+			if (ret == KNOT_ETRAIL) {
+				WARN("malformed message (%s)", knot_strerror(ret));
+			}
+
+			if (is_query) {
+				if (message->has_query_time_sec) {
+					timestamp = message->query_time_sec;
+				}
+			} else {
+				if (message->has_response_time_sec) {
+					timestamp = message->response_time_sec;
+				}
+				query_time = get_query_time(frame);
+			}
+
+			// Prepare connection information string.
+			fill_remote_addr(&net_ctx, message, is_initiator);
+
+			if (first_message) {
+				first_message = false;
+			} else {
+				printf("\n");
+			}
+
+			print_packet(pkt, &net_ctx, pkt->size, query_time, timestamp,
+			             is_query ^ is_initiator, &query->style);
+
+			net_clean(&net_ctx);
+		} else {
+			ERR("can't print dnstap message");
+		}
+
+		knot_pkt_free(pkt);
+		dt_reader_free_frame(reader, &frame);
+	}
+
+	return 0;
+}
+#endif // USE_DNSTAP
+
+static int add_query_edns(knot_pkt_t *packet, const query_t *query, uint16_t max_size)
+{
+	/* Initialize OPT RR. */
+	knot_rrset_t opt_rr;
+	int ret = knot_edns_init(&opt_rr, max_size, 0,
+	                         query->edns > -1 ? query->edns : 0, &packet->mm);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	if (query->flags.do_flag) {
+		knot_edns_set_do(&opt_rr);
+	}
+
+	/* Append NSID. */
+	if (query->nsid) {
+		ret = knot_edns_add_option(&opt_rr, KNOT_EDNS_OPTION_NSID,
+		                           0, NULL, &packet->mm);
+		if (ret != KNOT_EOK) {
+			knot_rrset_clear(&opt_rr, &packet->mm);
+			return ret;
+		}
+	}
+
+	/* Append EDNS-client-subnet. */
+	if (query->subnet.family != AF_UNSPEC) {
+		uint16_t size = knot_edns_client_subnet_size(&query->subnet);
+		uint8_t data[size];
+
+		ret = knot_edns_client_subnet_write(data, size, &query->subnet);
+		if (ret != KNOT_EOK) {
+			knot_rrset_clear(&opt_rr, &packet->mm);
+			return ret;
+		}
+
+		ret = knot_edns_add_option(&opt_rr, KNOT_EDNS_OPTION_CLIENT_SUBNET,
+		                           size, data, &packet->mm);
+		if (ret != KNOT_EOK) {
+			knot_rrset_clear(&opt_rr, &packet->mm);
+			return ret;
+		}
+	}
+
+	/* Append a cookie option if present. */
+	if (query->cc.len > 0) {
+		uint16_t size = knot_edns_cookie_size(&query->cc, &query->sc);
+		uint8_t data[size];
+
+		ret = knot_edns_cookie_write(data, size, &query->cc, &query->sc);
+		if (ret != KNOT_EOK) {
+			knot_rrset_clear(&opt_rr, &packet->mm);
+			return ret;
+		}
+
+		ret = knot_edns_add_option(&opt_rr, KNOT_EDNS_OPTION_COOKIE,
+		                           size, data, &packet->mm);
+		if (ret != KNOT_EOK) {
+			knot_rrset_clear(&opt_rr, &packet->mm);
+			return ret;
+		}
+	}
+
+	/* Append EDNS Padding. */
+	int padding = query->padding;
+	if (padding != -3 && query->alignment > 0) {
+		padding = knot_edns_alignment_size(packet->size,
+		                                   knot_rrset_size(&opt_rr),
+		                                   query->alignment);
+	} else if (query->padding == -2 || (query->padding == -1 && query->tls.enable)) {
+		padding = knot_pkt_default_padding_size(packet, &opt_rr);
+	}
+	if (padding > -1) {
+		uint8_t zeros[padding];
+		memset(zeros, 0, sizeof(zeros));
+
+		ret = knot_edns_add_option(&opt_rr, KNOT_EDNS_OPTION_PADDING,
+		                           padding, zeros, &packet->mm);
+		if (ret != KNOT_EOK) {
+			knot_rrset_clear(&opt_rr, &packet->mm);
+			return ret;
+		}
+	}
+
+	/* Append custom EDNS options. */
+	node_t *node;
+	WALK_LIST(node, query->edns_opts) {
+		ednsopt_t *opt = (ednsopt_t *)node;
+		ret = knot_edns_add_option(&opt_rr, opt->code, opt->length,
+		                           opt->data, &packet->mm);
+		if (ret != KNOT_EOK) {
+			knot_rrset_clear(&opt_rr, &packet->mm);
+			return ret;
+		}
+	}
+
+	/* Add prepared OPT to packet. */
+	ret = knot_pkt_put(packet, KNOT_COMPR_HINT_NONE, &opt_rr, KNOT_PF_FREE);
+	if (ret != KNOT_EOK) {
+		knot_rrset_clear(&opt_rr, &packet->mm);
+	}
+
+	return ret;
+}
+
+static bool do_padding(const query_t *query)
+{
+	return (query->padding != -3) &&                       // Disabled padding.
+	       (query->padding > -1 || query->alignment > 0 || // Explicit padding.
+	        query->padding == -2 ||                        // Default padding.
+	        (query->padding == -1 && query->tls.enable));  // TLS automatic.
+}
+
+static bool use_edns(const query_t *query)
+{
+	return query->edns > -1 || query->udp_size > -1 || query->nsid ||
+	       query->flags.do_flag || query->subnet.family != AF_UNSPEC ||
+	       query->cc.len > 0 || do_padding(query) ||
+	       !ednsopt_list_empty(&query->edns_opts);
+}
+
+static knot_pkt_t *create_query_packet(const query_t *query)
+{
+	// Set packet buffer size.
+	uint16_t max_size;
+	if (query->udp_size < 0) {
+		if (use_edns(query)) {
+			max_size = DEFAULT_EDNS_SIZE;
+		} else {
+			max_size = DEFAULT_UDP_SIZE;
+		}
+	} else {
+		max_size = query->udp_size;
+	}
+
+	// Create packet skeleton.
+	knot_pkt_t *packet = create_empty_packet(max_size);
+	if (packet == NULL) {
+		return NULL;
+	}
+
+	// Set ID = 0 for packet send over HTTPS
+	// Due HTTP cache it is convenient to set the query ID to 0 - GET messages has same header then
+#if defined(LIBNGHTTP2) || defined(ENABLE_QUIC)
+	if (query->https.enable || query->quic.enable) {
+		knot_wire_set_id(packet->wire, 0);
+	}
+#endif
+
+	// Set flags to wireformat.
+	if (query->flags.aa_flag) {
+		knot_wire_set_aa(packet->wire);
+	}
+	if (query->flags.tc_flag) {
+		knot_wire_set_tc(packet->wire);
+	}
+	if (query->flags.rd_flag) {
+		knot_wire_set_rd(packet->wire);
+	}
+	if (query->flags.ra_flag) {
+		knot_wire_set_ra(packet->wire);
+	}
+	if (query->flags.z_flag) {
+		knot_wire_set_z(packet->wire);
+	}
+	if (query->flags.ad_flag) {
+		knot_wire_set_ad(packet->wire);
+	}
+	if (query->flags.cd_flag) {
+		knot_wire_set_cd(packet->wire);
+	}
+
+	// Set NOTIFY opcode.
+	if (query->notify) {
+		knot_wire_set_opcode(packet->wire, KNOT_OPCODE_NOTIFY);
+	}
+
+	// Set packet question if available.
+	knot_dname_t *qname = NULL;
+	if (query->owner != NULL) {
+		qname = knot_dname_from_str_alloc(query->owner);
+		if (qname == NULL) {
+			ERR("'%s' is not a valid domain name", query->owner);
+			knot_pkt_free(packet);
+			return NULL;
+		}
+
+		int ret = knot_pkt_put_question(packet, qname, query->class_num,
+		                                query->type_num);
+		if (ret != KNOT_EOK) {
+			knot_dname_free(qname, NULL);
+			knot_pkt_free(packet);
+			return NULL;
+		}
+	}
+
+	// For IXFR query or NOTIFY query with SOA serial, add a proper section.
+	if (query->serial >= 0) {
+		if (query->notify) {
+			knot_pkt_begin(packet, KNOT_ANSWER);
+		} else {
+			knot_pkt_begin(packet, KNOT_AUTHORITY);
+		}
+
+		// SOA rdata in wireformat.
+		uint8_t wire[22] = { 0x0 };
+
+		// Create rrset with SOA record.
+		knot_rrset_t *soa = knot_rrset_new(qname,
+		                                   KNOT_RRTYPE_SOA,
+		                                   query->class_num,
+		                                   0,
+		                                   &packet->mm);
+		knot_dname_free(qname, NULL);
+		if (soa == NULL) {
+			knot_pkt_free(packet);
+			return NULL;
+		}
+
+		// Fill in blank SOA rdata to rrset.
+		int ret = knot_rrset_add_rdata(soa, wire, sizeof(wire), &packet->mm);
+		if (ret != KNOT_EOK) {
+			knot_rrset_free(soa, &packet->mm);
+			knot_pkt_free(packet);
+			return NULL;
+		}
+
+		// Set SOA serial.
+		knot_soa_serial_set(soa->rrs.rdata, query->serial);
+
+		ret = knot_pkt_put(packet, KNOT_COMPR_HINT_NONE, soa, KNOT_PF_FREE);
+		if (ret != KNOT_EOK) {
+			knot_rrset_free(soa, &packet->mm);
+			knot_pkt_free(packet);
+			return NULL;
+		}
+
+		free(soa);
+	} else {
+		knot_dname_free(qname, NULL);
+	}
+
+	// Begin additional section
+	knot_pkt_begin(packet, KNOT_ADDITIONAL);
+
+	// Create EDNS section if required.
+	if (use_edns(query)) {
+		int ret = add_query_edns(packet, query, max_size);
+		if (ret != KNOT_EOK) {
+			ERR("can't set up EDNS section");
+			knot_pkt_free(packet);
+			return NULL;
+		}
+	}
+
+	return packet;
+}
+
+static bool check_reply_id(const knot_pkt_t *reply,
+                           const knot_pkt_t *query)
+{
+	uint16_t query_id = knot_wire_get_id(query->wire);
+	uint16_t reply_id = knot_wire_get_id(reply->wire);
+
+	if (reply_id != query_id) {
+		WARN("reply ID (%u) is different from query ID (%u)",
+		     reply_id, query_id);
+		return false;
+	}
+
+	return true;
+}
+
+static void check_reply_qr(const knot_pkt_t *reply)
+{
+	if (!knot_wire_get_qr(reply->wire)) {
+		WARN("response QR bit not set");
+	}
+}
+
+static void check_reply_question(const knot_pkt_t *reply,
+                                 const knot_pkt_t *query)
+{
+	if (knot_wire_get_qdcount(reply->wire) < 1) {
+		WARN("response doesn't have question section");
+		return;
+	}
+
+	if (!knot_dname_is_equal(knot_pkt_wire_qname(reply), knot_pkt_wire_qname(query)) ||
+	    knot_pkt_qclass(reply) != knot_pkt_qclass(query) ||
+	    knot_pkt_qtype(reply)  != knot_pkt_qtype(query)) {
+		WARN("query/response question sections are different");
+		return;
+	}
+}
+
+static int64_t first_serial_check(const knot_pkt_t *reply, const knot_pkt_t *query)
+{
+	const knot_pktsection_t *answer = knot_pkt_section(reply, KNOT_ANSWER);
+
+	if (answer->count <= 0) {
+		return -1;
+	}
+
+	const knot_rrset_t *first = knot_pkt_rr(answer, 0);
+
+	if (first->type != KNOT_RRTYPE_SOA) {
+		return -1;
+	} else {
+		if (!knot_dname_is_case_equal(first->owner, knot_pkt_qname(query))) {
+			WARN("leading SOA owner not matching the requested zone name");
+		}
+
+		return knot_soa_serial(first->rrs.rdata);
+	}
+}
+
+static bool finished_xfr(const uint32_t serial, const knot_pkt_t *reply,
+                         const knot_pkt_t *query, const size_t msg_count, bool is_ixfr)
+{
+	const knot_pktsection_t *answer = knot_pkt_section(reply, KNOT_ANSWER);
+
+	if (answer->count <= 0) {
+		return false;
+	}
+
+	const knot_rrset_t *last = knot_pkt_rr(answer, answer->count - 1);
+
+	if (last->type != KNOT_RRTYPE_SOA) {
+		return false;
+	} else if (answer->count == 1 && msg_count == 1) {
+		return is_ixfr;
+	} else {
+		if (!knot_dname_is_case_equal(last->owner, knot_pkt_qname(query))) {
+			WARN("final SOA owner not matching the requested zone name");
+		}
+
+		return knot_soa_serial(last->rrs.rdata) == serial;
+	}
+}
+
+static int sign_query(knot_pkt_t *pkt, const query_t *query, sign_context_t *ctx)
+{
+	if (query->tsig_key.name == NULL) {
+		return KNOT_EOK;
+	}
+
+	int ret = sign_context_init_tsig(ctx, &query->tsig_key);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	ret = sign_packet(pkt, ctx);
+	if (ret != KNOT_EOK) {
+		sign_context_deinit(ctx);
+		return ret;
+	}
+
+	return KNOT_EOK;
+}
+
+static void net_close_keepopen(net_t *net, const query_t *query)
+{
+	if (!query->keepopen) {
+		net_close(net);
+	}
+}
+
+static int process_query_packet(const knot_pkt_t      *query,
+                                net_t                 *net,
+                                const query_t         *query_ctx,
+                                const bool            ignore_tc,
+                                const sign_context_t  *sign_ctx,
+                                const style_t         *style)
+{
+	struct timespec	t_start, t_query, t_query_full, t_end, t_end_full;
+	time_t		timestamp;
+	knot_pkt_t	*reply = NULL;
+	uint8_t		in[MAX_PACKET_SIZE];
+	int		in_len;
+	int		ret;
+
+	// Get start query time.
+	timestamp = time(NULL);
+	t_start = time_now();
+
+	// Connect to the server if not already connected.
+	if (net->sockfd < 0) {
+		ret = net_connect(net);
+		if (ret != KNOT_EOK) {
+			return -1;
+		}
+	}
+
+	// Send query packet.
+	ret = net_send(net, query->wire, query->size);
+	if (ret != KNOT_EOK) {
+		net_close(net);
+		return -1;
+	}
+
+	// Get stop query time and start reply time.
+	t_query = time_now();
+	t_query_full = time_diff(&t_start, &t_query);
+	t_query_full.tv_sec += timestamp;
+
+#if USE_DNSTAP
+	// Make the dnstap copy of the query.
+	write_dnstap(query_ctx->dt_writer, true, query->wire, query->size,
+	             net, &t_query_full);
+#endif // USE_DNSTAP
+
+	// Print query packet if required.
+	if (style->show_query && style->format != FORMAT_JSON) {
+		// Create copy of query packet for parsing.
+		knot_pkt_t *q = knot_pkt_new(query->wire, query->size, NULL);
+		if (q != NULL) {
+			if (knot_pkt_parse(q, KNOT_PF_NOCANON) == KNOT_EOK) {
+				print_packet(q, net, query->size,
+				             time_diff_ms(&t_start, &t_query),
+				             timestamp, false, style);
+			} else {
+				ERR("can't print query packet");
+			}
+			knot_pkt_free(q);
+		} else {
+			ERR("can't print query packet");
+		}
+
+		printf("\n");
+	}
+
+	// Loop over incoming messages, unless reply id is correct or timeout.
+	while (true) {
+		reply = NULL;
+
+		// Receive a reply message.
+		in_len = net_receive(net, in, sizeof(in));
+		if (in_len <= 0) {
+			goto fail;
+		}
+
+		// Get stop reply time.
+		t_end = time_now();
+		t_end_full = time_diff(&t_start, &t_end);
+		t_end_full.tv_sec += timestamp;
+
+#if USE_DNSTAP
+		// Make the dnstap copy of the response.
+		write_dnstap(query_ctx->dt_writer, false, in, in_len, net,
+		             &t_end_full);
+#endif // USE_DNSTAP
+
+		// Create reply packet structure to fill up.
+		reply = knot_pkt_new(in, in_len, NULL);
+		if (reply == NULL) {
+			ERR("internal error (%s)", knot_strerror(KNOT_ENOMEM));
+			goto fail;
+		}
+
+		// Parse reply to the packet structure.
+		ret = knot_pkt_parse(reply, KNOT_PF_NOCANON);
+		if (ret == KNOT_ETRAIL) {
+			WARN("malformed reply packet (%s)", knot_strerror(ret));
+		} else if (ret != KNOT_EOK) {
+			ERR("malformed reply packet from %s", net->remote_str);
+			goto fail;
+		}
+
+		// Compare reply header id.
+		if (check_reply_id(reply, query)) {
+			break;
+		// Check for timeout.
+		} else if (time_diff_ms(&t_query, &t_end) > 1000 * net->wait) {
+			goto fail;
+		}
+
+		knot_pkt_free(reply);
+	}
+
+	// Check for TC bit and repeat query with TCP if required.
+	if (knot_wire_get_tc(reply->wire) != 0 &&
+	    ignore_tc == false && net->socktype == SOCK_DGRAM) {
+		printf("\n");
+		WARN("truncated reply from %s, retrying over TCP\n",
+		     net->remote_str);
+		knot_pkt_free(reply);
+		net_close_keepopen(net, query_ctx);
+
+		net->socktype = SOCK_STREAM;
+
+		return process_query_packet(query, net, query_ctx, true,
+		                            sign_ctx, style);
+	}
+
+	// Check for question sections equality.
+	check_reply_question(reply, query);
+
+	// Check QR bit
+	check_reply_qr(reply);
+
+	// Print reply packet.
+	if (style->format != FORMAT_JSON) {
+		print_packet(reply, net, in_len, time_diff_ms(&t_start, &t_end),
+		             timestamp, true, style);
+	} else {
+		knot_pkt_t *q = knot_pkt_new(query->wire, query->size, NULL);
+		(void)knot_pkt_parse(q, KNOT_PF_NOCANON);
+		print_packets_json(q, reply, net, timestamp, style);
+		knot_pkt_free(q);
+	}
+
+	// Verify signature if a key was specified.
+	if (sign_ctx->digest != NULL) {
+		ret = verify_packet(reply, sign_ctx);
+		if (ret != KNOT_EOK) {
+			WARN("reply verification for %s (%s)",
+			     net->remote_str, knot_strerror(ret));
+		}
+	}
+
+	// Check for BADCOOKIE RCODE and repeat query with the new cookie if required.
+	if (knot_pkt_ext_rcode(reply) == KNOT_RCODE_BADCOOKIE && query_ctx->badcookie > 0) {
+		printf("\n");
+		WARN("bad cookie from %s, retrying with the received one\n",
+		     net->remote_str);
+		net_close_keepopen(net, query_ctx);
+
+		// Prepare new query context.
+		query_t new_ctx = *query_ctx;
+
+		uint8_t *opt = knot_pkt_edns_option(reply, KNOT_EDNS_OPTION_COOKIE);
+		if (opt == NULL) {
+			ERR("bad cookie, missing EDNS section");
+			goto fail;
+		}
+
+		const uint8_t *data = knot_edns_opt_get_data(opt);
+		uint16_t data_len = knot_edns_opt_get_length(opt);
+		ret = knot_edns_cookie_parse(&new_ctx.cc, &new_ctx.sc, data, data_len);
+		if (ret != KNOT_EOK) {
+			ERR("bad cookie, missing EDNS cookie option");
+			goto fail;
+		}
+		knot_pkt_free(reply);
+
+		// Restore the original client cookie.
+		new_ctx.cc = query_ctx->cc;
+
+		new_ctx.badcookie--;
+
+		knot_pkt_t *new_query = create_query_packet(&new_ctx);
+		ret = process_query_packet(new_query, net, &new_ctx, ignore_tc,
+		                           sign_ctx, style);
+		knot_pkt_free(new_query);
+
+		return ret;
+	}
+
+	knot_pkt_free(reply);
+	net_close_keepopen(net, query_ctx);
+
+	return 0;
+
+fail:
+	if (style->format == FORMAT_JSON) {
+		knot_pkt_t *q = knot_pkt_new(query->wire, query->size, NULL);
+		(void)knot_pkt_parse(q, KNOT_PF_NOCANON);
+		print_packets_json(q, reply, net, timestamp, style);
+		knot_pkt_free(q);
+	}
+
+	knot_pkt_free(reply);
+	net_close(net);
+
+	return -1;
+}
+
+static int process_query(const query_t *query, net_t *net)
+{
+	node_t     *server;
+	knot_pkt_t *out_packet;
+	int        ret;
+
+	// Create query packet.
+	out_packet = create_query_packet(query);
+	if (out_packet == NULL) {
+		ERR("can't create query packet");
+		return -1;
+	}
+
+	// Sign the query.
+	sign_context_t sign_ctx = { 0 };
+	ret = sign_query(out_packet, query, &sign_ctx);
+	if (ret != KNOT_EOK) {
+		ERR("can't sign the packet (%s)", knot_strerror(ret));
+		return -1;
+	}
+
+	// Reuse previous connection if available.
+	if (net->sockfd >= 0) {
+		DBG("Querying for owner(%s), class(%u), type(%u), reused connection",
+		    query->owner, query->class_num, query->type_num);
+
+		ret = process_query_packet(out_packet, net, query, query->ignore_tc,
+		                           &sign_ctx, &query->style);
+		goto finish;
+	}
+
+	// Get connection parameters.
+	int socktype = get_socktype(query->protocol, query->type_num);
+	int flags = query->fastopen ? NET_FLAGS_FASTOPEN : NET_FLAGS_NONE;
+
+	// Loop over server list to process query.
+	WALK_LIST(server, query->servers) {
+		srv_info_t *remote = (srv_info_t *)server;
+		int iptype = get_iptype(query->ip, remote);
+
+		DBG("Querying for owner(%s), class(%u), type(%u), server(%s), "
+		    "port(%s), protocol(%s)", query->owner, query->class_num,
+		    query->type_num, remote->name, remote->service,
+		    get_sockname(socktype));
+
+		// Loop over the number of retries.
+		for (size_t i = 0; i <= query->retries; i++) {
+			// Initialize network structure for current server.
+			ret = net_init(query->local, remote, iptype, socktype,
+			               query->wait, flags, &query->tls,
+			               &query->https, &query->quic,
+			               (struct sockaddr *)&query->proxy.src,
+			               (struct sockaddr *)&query->proxy.dst,
+			               net);
+			if (ret != KNOT_EOK) {
+				if (ret == KNOT_NET_EADDR) {
+					// Requested address family not available.
+					goto next_server;
+				}
+				continue;
+			}
+
+			// Loop over all resolved addresses for remote.
+			while (net->srv != NULL) {
+				ret = process_query_packet(out_packet, net,
+				                           query,
+				                           query->ignore_tc,
+				                           &sign_ctx,
+				                           &query->style);
+				// If error try next resolved address.
+				if (ret != 0) {
+					net->srv = net->srv->ai_next;
+					if (net->srv != NULL && query->style.show_query) {
+						printf("\n");
+					}
+
+					continue;
+				}
+
+				break;
+			}
+
+			// Success.
+			if (ret == 0) {
+				goto finish;
+			}
+
+			if (i < query->retries) {
+				DBG("retrying server %s@%s(%s)",
+				    remote->name, remote->service,
+				    get_sockname(socktype));
+
+				if (query->style.show_query) {
+					printf("\n");
+				}
+			}
+
+			net_clean(net);
+		}
+
+		ERR("failed to query server %s@%s(%s)",
+		    remote->name, remote->service, get_sockname(socktype));
+
+		// If not last server, print separation.
+		if (server->next->next && query->style.show_query) {
+			printf("\n");
+		}
+next_server:
+		continue;
+	}
+finish:
+	if (!query->keepopen || net->sockfd < 0) {
+		net_clean(net);
+	}
+	sign_context_deinit(&sign_ctx);
+	knot_pkt_free(out_packet);
+
+	if (ret == KNOT_NET_EADDR) {
+		WARN("no servers to query");
+	}
+
+	return ret;
+}
+
+static int process_xfr_packet(const knot_pkt_t      *query,
+                              net_t                 *net,
+                              const query_t         *query_ctx,
+                              const sign_context_t  *sign_ctx,
+                              const style_t         *style)
+{
+	struct timespec t_start, t_query, t_query_full, t_end, t_end_full;
+	time_t		timestamp;
+	knot_pkt_t      *reply = NULL;
+	uint8_t         in[MAX_PACKET_SIZE];
+	int             in_len;
+	int             ret;
+	int64_t         serial = 0;
+	size_t          total_len = 0;
+	size_t          msg_count = 0;
+	size_t          rr_count = 0;
+	jsonw_t         *w = NULL;
+
+	// Get start query time.
+	timestamp = time(NULL);
+	t_start = time_now();
+
+	// Connect to the server if not already connected.
+	if (net->sockfd < 0) {
+		ret = net_connect(net);
+		if (ret != KNOT_EOK) {
+			return -1;
+		}
+	}
+
+	// Send query packet.
+	ret = net_send(net, query->wire, query->size);
+	if (ret != KNOT_EOK) {
+		net_close(net);
+		return -1;
+	}
+
+	// Get stop query time and start reply time.
+	t_query = time_now();
+	t_query_full = time_diff(&t_start, &t_query);
+	t_query_full.tv_sec += timestamp;
+
+#if USE_DNSTAP
+	// Make the dnstap copy of the query.
+	write_dnstap(query_ctx->dt_writer, true, query->wire, query->size,
+	             net, &t_query_full);
+#endif // USE_DNSTAP
+
+	// Print query packet if required.
+	if (style->show_query && style->format != FORMAT_JSON) {
+		// Create copy of query packet for parsing.
+		knot_pkt_t *q = knot_pkt_new(query->wire, query->size, NULL);
+		if (q != NULL) {
+			if (knot_pkt_parse(q, KNOT_PF_NOCANON) == KNOT_EOK) {
+				print_packet(q, net, query->size,
+				             time_diff_ms(&t_start, &t_query),
+				             timestamp, false, style);
+			} else {
+				ERR("can't print query packet");
+			}
+			knot_pkt_free(q);
+		} else {
+			ERR("can't print query packet");
+		}
+
+		printf("\n");
+	}
+
+	// Loop over reply messages unless first and last SOA serials differ.
+	while (true) {
+		reply = NULL;
+
+		// Receive a reply message.
+		in_len = net_receive(net, in, sizeof(in));
+		if (in_len <= 0) {
+			goto fail;
+		}
+
+		// Get stop message time.
+		t_end = time_now();
+		t_end_full = time_diff(&t_start, &t_end);
+		t_end_full.tv_sec += timestamp;
+
+#if USE_DNSTAP
+		// Make the dnstap copy of the response.
+		write_dnstap(query_ctx->dt_writer, false, in, in_len, net,
+		             &t_end_full);
+#endif // USE_DNSTAP
+
+		// Create reply packet structure to fill up.
+		reply = knot_pkt_new(in, in_len, NULL);
+		if (reply == NULL) {
+			ERR("internal error (%s)", knot_strerror(KNOT_ENOMEM));
+			goto fail;
+		}
+
+		// Parse reply to the packet structure.
+		ret = knot_pkt_parse(reply, KNOT_PF_NOCANON);
+		if (ret == KNOT_ETRAIL) {
+			WARN("malformed reply packet (%s)", knot_strerror(ret));
+		} else if (ret != KNOT_EOK) {
+			ERR("malformed reply packet from %s", net->remote_str);
+			goto fail;
+		}
+
+		// Compare reply header id.
+		if (check_reply_id(reply, query) == false) {
+			ERR("reply ID mismatch from %s", net->remote_str);
+			goto fail;
+		}
+
+		// Print leading transfer information.
+		if (msg_count == 0) {
+			if (style->format != FORMAT_JSON) {
+				print_header_xfr(query, style);
+			} else {
+				knot_pkt_t *q = knot_pkt_new(query->wire, query->size, NULL);
+				(void)knot_pkt_parse(q, KNOT_PF_NOCANON);
+				w = print_header_xfr_json(q, timestamp, style);
+				knot_pkt_free(q);
+			}
+		}
+
+		// Check for error reply.
+		if (knot_pkt_ext_rcode(reply) != KNOT_RCODE_NOERROR) {
+			ERR("server replied with error '%s'",
+			    knot_pkt_ext_rcode_name(reply));
+			goto fail;
+		}
+
+		// The first message has a special treatment.
+		if (msg_count == 0) {
+			// Verify 1. signature if a key was specified.
+			if (sign_ctx->digest != NULL) {
+				ret = verify_packet(reply, sign_ctx);
+				if (ret != KNOT_EOK) {
+					style_t tsig_style = {
+						.format = style->format,
+						.style = style->style,
+						.show_tsig = true
+					};
+					if (style->format != FORMAT_JSON) {
+						print_data_xfr(reply, &tsig_style);
+					}
+
+					ERR("reply verification for %s (%s)",
+					    net->remote_str, knot_strerror(ret));
+					goto fail;
+				}
+			}
+
+			// Read first SOA serial.
+			serial = first_serial_check(reply, query);
+
+			if (serial < 0) {
+				ERR("first answer record from %s isn't SOA",
+				    net->remote_str);
+				goto fail;
+			}
+
+			// Check for question sections equality.
+			check_reply_question(reply, query);
+
+			// Check QR bit
+			check_reply_qr(reply);
+		}
+
+		msg_count++;
+		rr_count += knot_wire_get_ancount(reply->wire);
+		total_len += in_len;
+
+		// Print reply packet.
+		if (style->format != FORMAT_JSON) {
+			print_data_xfr(reply, style);
+		} else {
+			print_data_xfr_json(w, reply, timestamp);
+		}
+
+		// Check for finished transfer.
+		if (finished_xfr(serial, reply, query, msg_count, query_ctx->serial != -1)) {
+			knot_pkt_free(reply);
+			break;
+		}
+
+		knot_pkt_free(reply);
+		reply = NULL;
+	}
+
+	// Print full transfer information.
+	t_end = time_now();
+	if (style->format != FORMAT_JSON) {
+		print_footer_xfr(total_len, msg_count, rr_count, net,
+		                 time_diff_ms(&t_query, &t_end), timestamp, style);
+	} else {
+		print_footer_xfr_json(&w, style);
+	}
+
+	net_close_keepopen(net, query_ctx);
+
+	return 0;
+
+fail:
+	// Print partial transfer information.
+	t_end = time_now();
+	if (style->format != FORMAT_JSON) {
+		print_footer_xfr(total_len, msg_count, rr_count, net,
+		                 time_diff_ms(&t_query, &t_end), timestamp, style);
+	} else {
+		print_data_xfr_json(w, reply, timestamp);
+		print_footer_xfr_json(&w, style);
+	}
+
+	knot_pkt_free(reply);
+	net_close(net);
+	free(w);
+
+	return -1;
+}
+
+static int process_xfr(const query_t *query, net_t *net)
+{
+	knot_pkt_t *out_packet;
+	int        ret;
+
+	// Create query packet.
+	out_packet = create_query_packet(query);
+	if (out_packet == NULL) {
+		ERR("can't create query packet");
+		return -1;
+	}
+
+	// Sign the query.
+	sign_context_t sign_ctx = { 0 };
+	ret = sign_query(out_packet, query, &sign_ctx);
+	if (ret != KNOT_EOK) {
+		ERR("can't sign the packet (%s)", knot_strerror(ret));
+		return -1;
+	}
+
+	// Reuse previous connection if available.
+	if (net->sockfd >= 0) {
+		DBG("Querying for owner(%s), class(%u), type(%u), reused connection",
+		    query->owner, query->class_num, query->type_num);
+
+		ret = process_xfr_packet(out_packet, net, query,
+		                         &sign_ctx, &query->style);
+		goto finish;
+	}
+
+	// Get connection parameters.
+	int socktype = get_socktype(query->protocol, query->type_num);
+	int flags = query->fastopen ? NET_FLAGS_FASTOPEN : NET_FLAGS_NONE;
+
+	// Use the first nameserver from the list.
+	srv_info_t *remote = HEAD(query->servers);
+	int iptype = get_iptype(query->ip, remote);
+
+	DBG("Querying for owner(%s), class(%u), type(%u), server(%s), "
+	    "port(%s), protocol(%s)", query->owner, query->class_num,
+	    query->type_num, remote->name, remote->service,
+	    get_sockname(socktype));
+
+	// Initialize network structure.
+	ret = net_init(query->local, remote, iptype, socktype, query->wait,
+	               flags, &query->tls, &query->https, &query->quic,
+	               (struct sockaddr *)&query->proxy.src,
+	               (struct sockaddr *)&query->proxy.dst,
+	               net);
+	if (ret != KNOT_EOK) {
+		sign_context_deinit(&sign_ctx);
+		knot_pkt_free(out_packet);
+		return -1;
+	}
+
+	// Loop over all resolved addresses for remote.
+	while (net->srv != NULL) {
+		ret = process_xfr_packet(out_packet, net,
+		                         query,
+		                         &sign_ctx,
+		                         &query->style);
+		// If error try next resolved address.
+		if (ret != 0) {
+			net->srv = (net->srv)->ai_next;
+			continue;
+		}
+
+		break;
+	}
+
+	if (ret != 0) {
+		ERR("failed to query server %s@%s(%s)",
+		    remote->name, remote->service, get_sockname(socktype));
+	}
+finish:
+	if (!query->keepopen || net->sockfd < 0) {
+		net_clean(net);
+	}
+	sign_context_deinit(&sign_ctx);
+	knot_pkt_free(out_packet);
+
+	return ret;
+}
+
+int kdig_exec(const kdig_params_t *params)
+{
+	node_t *n;
+	net_t net = { .sockfd = -1 };
+
+	if (params == NULL) {
+		DBG_NULL;
+		return KNOT_EINVAL;
+	}
+
+	bool success = true;
+
+	// Loop over query list.
+	WALK_LIST(n, params->queries) {
+		query_t *query = (query_t *)n;
+
+		int ret = -1;
+		switch (query->operation) {
+		case OPERATION_QUERY:
+			ret = process_query(query, &net);
+			break;
+		case OPERATION_XFR:
+			ret = process_xfr(query, &net);
+			break;
+#if USE_DNSTAP
+		case OPERATION_LIST_DNSTAP:
+			ret = process_dnstap(query);
+			break;
+#endif // USE_DNSTAP
+		default:
+			ERR("unsupported operation");
+			break;
+		}
+
+		// All operations must succeed.
+		if (ret != 0) {
+			success = false;
+		}
+
+		// If not last query, print separation.
+		if (n->next->next && params->config->style.format == FORMAT_FULL) {
+			printf("\n");
+		}
+	}
+
+	if (net.sockfd >= 0) {
+		net_close(&net);
+		net_clean(&net);
+	}
+
+	return success ? KNOT_EOK : KNOT_ERROR;
+}
diff --git a/src/utils/kdig/kdig_exec.h b/src/utils/kdig/kdig_exec.h
new file mode 100644
index 0000000..99167ce
--- /dev/null
+++ b/src/utils/kdig/kdig_exec.h
@@ -0,0 +1,21 @@
+/*  Copyright (C) 2018 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/>.
+ */
+
+#pragma once
+
+#include "utils/kdig/kdig_params.h"
+
+int kdig_exec(const kdig_params_t *params);
diff --git a/src/utils/kdig/kdig_main.c b/src/utils/kdig/kdig_main.c
new file mode 100644
index 0000000..534d50e
--- /dev/null
+++ b/src/utils/kdig/kdig_main.c
@@ -0,0 +1,45 @@
+/*  Copyright (C) 2018 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 <stdlib.h>
+
+#include "libdnssec/crypto.h"
+#include "utils/kdig/kdig_params.h"
+#include "utils/kdig/kdig_exec.h"
+#include "libknot/libknot.h"
+
+int main(int argc, char *argv[])
+{
+	int ret = EXIT_SUCCESS;
+
+	tzset();
+
+	kdig_params_t params;
+	if (kdig_parse(&params, argc, argv) == KNOT_EOK) {
+		if (!params.stop) {
+			dnssec_crypto_init();
+			if (kdig_exec(&params) != KNOT_EOK) {
+				ret = EXIT_FAILURE;
+			}
+			dnssec_crypto_cleanup();
+		}
+	} else {
+		ret = EXIT_FAILURE;
+	}
+
+	kdig_clean(&params);
+	return ret;
+}
diff --git a/src/utils/kdig/kdig_params.c b/src/utils/kdig/kdig_params.c
new file mode 100644
index 0000000..fce9405
--- /dev/null
+++ b/src/utils/kdig/kdig_params.c
@@ -0,0 +1,2740 @@
+/*  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 <arpa/inet.h>
+#include <locale.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "utils/kdig/kdig_params.h"
+#include "utils/common/cert.h"
+#include "utils/common/hex.h"
+#include "utils/common/msg.h"
+#include "utils/common/netio.h"
+#include "utils/common/params.h"
+#include "utils/common/resolv.h"
+#include "libknot/descriptor.h"
+#include "libknot/libknot.h"
+#include "contrib/base64.h"
+#include "contrib/sockaddr.h"
+#include "contrib/string.h"
+#include "contrib/strtonum.h"
+#include "contrib/time.h"
+#include "contrib/ucw/lists.h"
+#include "libdnssec/error.h"
+#include "libdnssec/random.h"
+
+#define PROGRAM_NAME "kdig"
+
+#define DEFAULT_RETRIES_DIG		2
+#define DEFAULT_TIMEOUT_DIG		5
+#define DEFAULT_ALIGNMENT_SIZE		128
+#define DEFAULT_TLS_OCSP_STAPLING	(7 * 24 * 3600)
+
+#define BADCOOKIE_RETRY_MAX		10
+
+static const flags_t DEFAULT_FLAGS_DIG = {
+	.aa_flag = false,
+	.tc_flag = false,
+	.rd_flag = true,
+	.ra_flag = false,
+	.z_flag  = false,
+	.ad_flag = true,
+	.cd_flag = false,
+	.do_flag = false
+};
+
+static const style_t DEFAULT_STYLE_DIG = {
+	.format = FORMAT_FULL,
+	.style = {
+		.wrap = false,
+		.show_class = true,
+		.show_ttl = true,
+		.verbose = false,
+		.original_ttl = false,
+		.empty_ttl = false,
+		.human_ttl = false,
+		.human_timestamp = true,
+		.generic = false,
+		.ascii_to_idn = name_to_idn
+	},
+	.show_query = false,
+	.show_header = true,
+	.show_section = true,
+	.show_edns = true,
+	.show_question = true,
+	.show_answer = true,
+	.show_authority = true,
+	.show_additional = true,
+	.show_tsig = true,
+	.show_footer = true
+};
+
+static int opt_multiline(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.style.wrap = true;
+	q->style.format = FORMAT_FULL;
+	q->style.show_header = true;
+	q->style.show_edns = true;
+	q->style.show_footer = true;
+	q->style.style.verbose = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nomultiline(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.style.wrap = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_short(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.format = FORMAT_DIG;
+	q->style.show_header = false;
+	q->style.show_edns = false;
+	q->style.show_footer = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_noshort(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.format = FORMAT_FULL;
+
+	return KNOT_EOK;
+}
+
+static int opt_generic(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.style.generic = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nogeneric(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.style.generic = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_aaflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.aa_flag = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noaaflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.aa_flag = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_tcflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.tc_flag = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_notcflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.tc_flag = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_rdflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.rd_flag = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nordflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.rd_flag = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_raflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.ra_flag = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noraflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.ra_flag = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_zflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.z_flag = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nozflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.z_flag = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_adflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.ad_flag = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noadflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.ad_flag = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_cdflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.cd_flag = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nocdflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.cd_flag = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_doflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.do_flag = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nodoflag(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->flags.do_flag = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_all(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_header = true;
+	q->style.show_section = true;
+	q->style.show_edns = true;
+	q->style.show_question = true;
+	q->style.show_answer = true;
+	q->style.show_authority = true;
+	q->style.show_additional = true;
+	q->style.show_tsig = true;
+	q->style.show_footer = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noall(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_header = false;
+	q->style.show_section = false;
+	q->style.show_edns = false;
+	q->style.show_query = false;
+	q->style.show_question = false;
+	q->style.show_answer = false;
+	q->style.show_authority = false;
+	q->style.show_additional = false;
+	q->style.show_tsig = false;
+	q->style.show_footer = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_qr(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_query = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noqr(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_query = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_header(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_header = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noheader(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_header = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_comments(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_section = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nocomments(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_section = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_opt(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_edns = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noopt(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_edns = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_opttext(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_edns_opt_text = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noopttext(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_edns_opt_text = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_question(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_question = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noquestion(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_question = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_answer(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_answer = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noanswer(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_answer = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_authority(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_authority = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noauthority(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_authority = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_additional(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_additional = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noadditional(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_additional = false;
+	q->style.show_edns = false;
+	q->style.show_tsig = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_tsig(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_tsig = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_notsig(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_tsig = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_stats(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_footer = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nostats(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.show_footer = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_class(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.style.show_class = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noclass(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.style.show_class = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_ttl(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.style.show_ttl = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nottl(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.style.show_ttl = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_ignore(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->ignore_tc = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_noignore(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->ignore_tc = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_crypto(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.style.hide_crypto = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_nocrypto(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.style.hide_crypto = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_tcp(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->protocol = PROTO_TCP;
+
+	return KNOT_EOK;
+}
+
+static int opt_notcp(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->protocol = PROTO_UDP;
+	return opt_ignore(arg, query);
+}
+
+static int opt_fastopen(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->fastopen = true;
+
+	return opt_tcp(arg, query);
+}
+
+static int opt_nofastopen(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->fastopen = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_keepopen(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->keepopen = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nokeepopen(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->keepopen = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_tls(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->tls.enable = true;
+	return opt_tcp(arg, query);
+}
+
+static int opt_notls(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	tls_params_clean(&q->tls);
+	tls_params_init(&q->tls);
+
+	return KNOT_EOK;
+}
+
+static int opt_tls_ca(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	if (arg == NULL) {
+		q->tls.system_ca = true;
+		return opt_tls(arg, query);
+	} else {
+		if (ptrlist_add(&q->tls.ca_files, strdup(arg), NULL) == NULL) {
+			return KNOT_ENOMEM;
+		}
+		return opt_tls(arg, query);
+	}
+}
+
+static int opt_notls_ca(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->tls.system_ca = false;
+
+	ptrnode_t *node, *nxt;
+	WALK_LIST_DELSAFE(node, nxt, q->tls.ca_files) {
+		free(node->d);
+	}
+	ptrlist_free(&q->tls.ca_files, NULL);
+
+	return KNOT_EOK;
+}
+
+static int opt_tls_pin(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	uint8_t pin[64] = { 0 };
+
+	int ret = knot_base64_decode((const uint8_t *)arg, strlen(arg), pin, sizeof(pin));
+	if (ret < 0) {
+		ERR("invalid +tls-pin=%s", arg);
+		return ret;
+	} else if (ret != CERT_PIN_LEN) { // Check for 256-bit value.
+		ERR("invalid sha256 hash length +tls-pin=%s", arg);
+		return KNOT_EINVAL;
+	}
+
+	uint8_t *item = malloc(1 + ret); // 1 ~ leading data length.
+	if (item == NULL) {
+		return KNOT_ENOMEM;
+	}
+	item[0] = ret;
+	memcpy(&item[1], pin, ret);
+
+	if (ptrlist_add(&q->tls.pins, item, NULL) == NULL) {
+		return KNOT_ENOMEM;
+	}
+
+	return opt_tls(arg, query);
+}
+
+static int opt_notls_pin(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	ptrnode_t *node, *nxt;
+	WALK_LIST_DELSAFE(node, nxt, q->tls.pins) {
+		free(node->d);
+	}
+	ptrlist_free(&q->tls.pins, NULL);
+
+	return KNOT_EOK;
+}
+
+static int opt_tls_hostname(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	free(q->tls.hostname);
+	q->tls.hostname = strdup(arg);
+
+	return opt_tls(arg, query);
+}
+
+static int opt_notls_hostname(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	free(q->tls.hostname);
+	q->tls.hostname = NULL;
+
+	return KNOT_EOK;
+}
+
+static int opt_tls_sni(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	free(q->tls.sni);
+	q->tls.sni = strdup(arg);
+
+	return opt_tls(arg, query);
+}
+
+static int opt_notls_sni(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	free(q->tls.sni);
+	q->tls.sni = NULL;
+
+	return KNOT_EOK;
+}
+
+static int opt_tls_keyfile(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	free(q->tls.keyfile);
+	q->tls.keyfile = strdup(arg);
+
+	return opt_tls(arg, query);
+}
+
+static int opt_notls_keyfile(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	free(q->tls.keyfile);
+	q->tls.keyfile = NULL;
+
+	return KNOT_EOK;
+}
+
+static int opt_tls_certfile(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	free(q->tls.certfile);
+	q->tls.certfile = strdup(arg);
+
+	return opt_tls(arg, query);
+}
+
+static int opt_notls_certfile(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	free(q->tls.certfile);
+	q->tls.certfile = NULL;
+
+	return KNOT_EOK;
+}
+
+static int opt_tls_ocsp_stapling(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	if (arg == NULL) {
+		q->tls.ocsp_stapling = DEFAULT_TLS_OCSP_STAPLING;
+		return opt_tls(arg, query);
+	} else {
+		uint32_t num = 0;
+		if (str_to_u32(arg, &num) != KNOT_EOK || num == 0) {
+			ERR("invalid +tls-ocsp-stapling=%s", arg);
+			return KNOT_EINVAL;
+		}
+
+		q->tls.ocsp_stapling = 3600 * num;
+		return opt_tls(arg, query);
+	}
+}
+
+static int opt_notls_ocsp_stapling(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->tls.ocsp_stapling = 0;
+
+	return KNOT_EOK;
+}
+
+static int opt_https(const char *arg, void *query)
+{
+#ifdef LIBNGHTTP2
+	query_t *q = query;
+
+	q->https.enable = true;
+
+	if (arg != NULL) {
+		char *resource = strstr(arg, "://");
+		if (resource == NULL) {
+			resource = (char *)arg;
+		} else {
+			resource += 3;  // strlen("://")
+			if (*resource == '\0') {
+				ERR("invalid +https=%s", arg);
+				return KNOT_EINVAL;
+			}
+		}
+
+		char *tmp_path = strchr(resource, '/');
+		if (tmp_path) {
+			free(q->https.path);
+			q->https.path = strdup(tmp_path);
+
+			if (tmp_path != resource) {
+				free(q->tls.hostname);
+				q->tls.hostname = strndup(resource, (size_t)(tmp_path - resource));
+			}
+			return opt_tls(arg, query);
+		} else {
+			return opt_tls_hostname(arg, query);
+		}
+
+	}
+
+	return opt_tls(arg, query);
+
+#else
+	return KNOT_ENOTSUP;
+#endif //LIBNGHTTP2
+}
+
+static int opt_nohttps(const char *arg, void *query)
+{
+#ifdef LIBNGHTTP2
+	query_t *q = query;
+
+	https_params_clean(&q->https);
+
+	return opt_notls(arg, query);
+#else
+	return KNOT_ENOTSUP;
+#endif //LIBNGHTTP2
+}
+
+static int opt_https_get(const char *arg, void *query)
+{
+#ifdef LIBNGHTTP2
+	query_t *q = query;
+
+	q->https.method = GET;
+
+	return opt_https(arg, query);
+#else
+	return KNOT_ENOTSUP;
+#endif //LIBNGHTTP2
+}
+
+static int opt_nohttps_get(const char *arg, void *query)
+{
+#ifdef LIBNGHTTP2
+	query_t *q = query;
+
+	q->https.method = POST;
+
+	return KNOT_EOK;
+#else
+	return KNOT_ENOTSUP;
+#endif
+}
+
+static int opt_quic(const char *arg, void *query)
+{
+#ifdef ENABLE_QUIC
+	query_t *q = query;
+
+	q->quic.enable = true;
+
+	opt_tls(arg, query);
+	opt_notcp(arg, query);
+
+	return KNOT_EOK;
+#else
+	return KNOT_ENOTSUP;
+#endif //ENABLE_QUIC
+}
+
+static int opt_noquic(const char *arg, void *query)
+{
+#ifdef ENABLE_QUIC
+	query_t *q = query;
+
+	quic_params_clean(&q->quic);
+
+	return opt_notls(arg, query);
+#else
+	return KNOT_ENOTSUP;
+#endif //ENABLE_QUIC
+}
+
+static int opt_nsid(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->nsid = true;
+
+	return KNOT_EOK;
+}
+
+static int opt_nonsid(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->nsid = false;
+
+	return KNOT_EOK;
+}
+
+static int opt_bufsize(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	uint16_t num = 0;
+	if (str_to_u16(arg, &num) != KNOT_EOK) {
+		ERR("invalid +bufsize=%s", arg);
+		return KNOT_EINVAL;
+	}
+
+	// Disable EDNS if zero bufsize.
+	if (num == 0) {
+		q->udp_size = -1;
+	} else if (num < KNOT_WIRE_HEADER_SIZE) {
+		q->udp_size = KNOT_WIRE_HEADER_SIZE;
+	} else {
+		q->udp_size = num;
+	}
+
+	return KNOT_EOK;
+}
+
+static int opt_nobufsize(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->udp_size = -1;
+
+	return KNOT_EOK;
+}
+
+static int opt_cookie(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	if (arg != NULL) {
+		uint8_t *input = NULL;
+		size_t input_len;
+
+		int ret = hex_decode(arg, &input, &input_len);
+		if (ret != KNOT_EOK) {
+			ERR("invalid +cookie=%s", arg);
+			return KNOT_EINVAL;
+		}
+
+		if (input_len < KNOT_EDNS_COOKIE_CLNT_SIZE) {
+			ERR("too short client +cookie=%s", arg);
+			free(input);
+			return KNOT_EINVAL;
+		}
+		q->cc.len = KNOT_EDNS_COOKIE_CLNT_SIZE;
+		memcpy(q->cc.data, input, q->cc.len);
+
+		input_len -= q->cc.len;
+		if (input_len > 0) {
+			if (input_len < KNOT_EDNS_COOKIE_SRVR_MIN_SIZE) {
+				ERR("too short server +cookie=%s", arg);
+				free(input);
+				return KNOT_EINVAL;
+			}
+			if (input_len > KNOT_EDNS_COOKIE_SRVR_MAX_SIZE) {
+				ERR("too long server +cookie=%s", arg);
+				free(input);
+				return KNOT_EINVAL;
+			}
+			q->sc.len = input_len;
+			memcpy(q->sc.data, input + q->cc.len, q->sc.len);
+		}
+
+		free(input);
+	} else {
+		q->cc.len = KNOT_EDNS_COOKIE_CLNT_SIZE;
+
+		int ret = dnssec_random_buffer(q->cc.data, q->cc.len);
+		if (ret != DNSSEC_EOK) {
+			return knot_error_from_libdnssec(ret);
+		}
+	}
+
+	return KNOT_EOK;
+}
+
+static int opt_nocookie(const char *arg, void *query)
+{
+	query_t *q = query;
+	q->cc.len = 0;
+	q->sc.len = 0;
+	return KNOT_EOK;
+}
+
+static int opt_badcookie(const char *arg, void *query)
+{
+	query_t *q = query;
+	q->badcookie = BADCOOKIE_RETRY_MAX;
+	return KNOT_EOK;
+}
+
+static int opt_nobadcookie(const char *arg, void *query)
+{
+	query_t *q = query;
+	q->badcookie = 0;
+	return KNOT_EOK;
+}
+
+static int opt_padding(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	if (arg == NULL) {
+		q->padding = -2;
+		return KNOT_EOK;
+	} else {
+		uint16_t num = 0;
+		if (str_to_u16(arg, &num) != KNOT_EOK) {
+			ERR("invalid +padding=%s", arg);
+			return KNOT_EINVAL;
+		}
+
+		q->padding = num;
+		return KNOT_EOK;
+	}
+}
+
+static int opt_nopadding(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->padding = -3;
+
+	return KNOT_EOK;
+}
+
+static int opt_alignment(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	if (arg == NULL) {
+		q->alignment = DEFAULT_ALIGNMENT_SIZE;
+		return KNOT_EOK;
+	} else {
+		uint16_t num = 0;
+		if (str_to_u16(arg, &num) != KNOT_EOK || num < 2) {
+			ERR("invalid +alignment=%s", arg);
+			return KNOT_EINVAL;
+		}
+
+		q->alignment = num;
+		return KNOT_EOK;
+	}
+}
+
+static int opt_noalignment(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->alignment = 0;
+
+	return KNOT_EOK;
+}
+
+static int opt_subnet(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	char         *sep = NULL;
+	const size_t arg_len = strlen(arg);
+	const char   *arg_end = arg + arg_len;
+	size_t       addr_len = 0;
+
+	// Separate address and network mask.
+	if ((sep = strchr(arg, '/')) != NULL) {
+		addr_len = sep - arg;
+	} else {
+		addr_len = arg_len;
+	}
+
+	// Check IP address.
+
+	struct sockaddr_storage ss = { 0 };
+	struct addrinfo hints = { .ai_flags = AI_NUMERICHOST };
+	struct addrinfo *ai = NULL;
+
+	char *addr_str = strndup(arg, addr_len);
+	if (getaddrinfo(addr_str, NULL, &hints, &ai) != 0) {
+		free(addr_str);
+		ERR("invalid address +subnet=%s", arg);
+		return KNOT_EINVAL;
+	}
+
+	memcpy(&ss, ai->ai_addr, ai->ai_addrlen);
+	freeaddrinfo(ai);
+	free(addr_str);
+
+	if (knot_edns_client_subnet_set_addr(&q->subnet, &ss) != KNOT_EOK) {
+		ERR("invalid address +subnet=%s", arg);
+		return KNOT_EINVAL;
+	}
+
+	// Parse network mask.
+	const char *mask = arg;
+	if (mask + addr_len < arg_end) {
+		mask += addr_len + 1;
+		uint8_t num = 0;
+		if (str_to_u8(mask, &num) != KNOT_EOK || num > q->subnet.source_len) {
+			ERR("invalid network mask +subnet=%s", arg);
+			return KNOT_EINVAL;
+		}
+		q->subnet.source_len = num;
+	}
+
+	return KNOT_EOK;
+}
+
+static int opt_nosubnet(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->subnet.family = AF_UNSPEC;
+
+	return KNOT_EOK;
+}
+
+static int opt_edns(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	if (arg == NULL) {
+		q->edns = 0;
+		return KNOT_EOK;
+	} else {
+		uint8_t num = 0;
+		if (str_to_u8(arg, &num) != KNOT_EOK) {
+			ERR("invalid +edns=%s", arg);
+			return KNOT_EINVAL;
+		}
+
+		q->edns = num;
+		return KNOT_EOK;
+	}
+}
+
+static int opt_noedns(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->edns = -1;
+	opt_nodoflag(arg, query);
+	opt_nonsid(arg, query);
+	opt_nobufsize(arg, query);
+	opt_nocookie(arg, query);
+	opt_nopadding(arg, query);
+	opt_noalignment(arg, query);
+	opt_nosubnet(arg, query);
+
+	return KNOT_EOK;
+}
+
+static int opt_timeout(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	if (params_parse_wait(arg, &q->wait) != KNOT_EOK) {
+		ERR("invalid +timeout=%s", arg);
+		return KNOT_EINVAL;
+	}
+
+	return KNOT_EOK;
+}
+
+static int opt_notimeout(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	(void)params_parse_wait("0", &q->wait);
+
+	return KNOT_EOK;
+}
+
+static int opt_retry(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	if (str_to_u32(arg, &q->retries) != KNOT_EOK) {
+		ERR("invalid +retry=%s", arg);
+		return KNOT_EINVAL;
+	}
+
+	return KNOT_EOK;
+}
+
+static int opt_noretry(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->retries = 0;
+
+	return KNOT_EOK;
+}
+
+static int opt_expire(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	ednsopt_t *opt = ednsopt_create(KNOT_EDNS_OPTION_EXPIRE, 0, NULL);
+	add_tail(&q->edns_opts, &opt->n);
+
+	return KNOT_EOK;
+}
+
+static int opt_noexpire(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	ednsopt_t *node, *nxt;
+	WALK_LIST_DELSAFE(node, nxt, q->edns_opts) {
+		ednsopt_t *opt = node;
+		if (opt->code == KNOT_EDNS_OPTION_EXPIRE) {
+			rem_node(&opt->n);
+			ednsopt_free(opt);
+		}
+	}
+
+	return KNOT_EOK;
+}
+
+static int parse_ednsopt(const char *arg, ednsopt_t **opt_ptr)
+{
+	errno = 0;
+	char *end = NULL;
+	unsigned long code = strtoul(arg, &end, 10);
+	if (errno != 0 || arg == end || code > UINT16_MAX) {
+		return KNOT_EINVAL;
+	}
+
+	size_t length = 0;
+	uint8_t *data = NULL;
+	if (end[0] == ':') {
+		if (end[1] != '\0') {
+			int ret = hex_decode(end + 1, &data, &length);
+			if (ret != KNOT_EOK) {
+				return ret;
+			}
+			if (length > UINT16_MAX) {
+				free(data);
+				return KNOT_ERANGE;
+			}
+		}
+	} else if (end[0] != '\0') {
+		return KNOT_EINVAL;
+	}
+
+	ednsopt_t *opt = ednsopt_create(code, length, data);
+	if (opt == NULL) {
+		free(data);
+		return KNOT_ENOMEM;
+	}
+
+	*opt_ptr = opt;
+	return KNOT_EOK;
+}
+
+static int opt_ednsopt(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	ednsopt_t *opt = NULL;
+	int ret = parse_ednsopt(arg, &opt);
+	if (ret != KNOT_EOK) {
+		ERR("invalid +ednsopt=%s", arg);
+		return KNOT_EINVAL;
+	}
+
+	add_tail(&q->edns_opts, &opt->n);
+
+	return KNOT_EOK;
+}
+
+static int opt_noednsopt(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	ednsopt_list_deinit(&q->edns_opts);
+
+	return KNOT_EOK;
+}
+
+static int opt_noidn(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->idn = false;
+	q->style.style.ascii_to_idn = NULL;
+
+	return KNOT_EOK;
+}
+
+static int opt_json(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.format = FORMAT_JSON;
+
+	return KNOT_EOK;
+}
+
+static int opt_nojson(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->style.format = FORMAT_FULL;
+
+	return KNOT_EOK;
+}
+
+static int parse_addr(struct sockaddr_storage *addr, const char *arg, const char *def_port)
+{
+	srv_info_t *info = parse_nameserver(arg, def_port);
+	if (info == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	struct addrinfo *addr_info = NULL;
+	int ret = getaddrinfo(info->name, info->service, NULL, &addr_info);
+	srv_info_free(info);
+	if (ret != 0) {
+		return KNOT_EINVAL;
+	}
+
+	memcpy(addr, addr_info->ai_addr, addr_info->ai_addrlen);
+	freeaddrinfo(addr_info);
+
+	return KNOT_EOK;
+}
+
+static int opt_proxy(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	const char *sep = strchr(arg, '-');
+	if (sep == NULL || sep == arg || *(sep + 1) == '\0') {
+		ERR("invalid specification +proxy=%s", arg);
+		return KNOT_EINVAL;
+	}
+
+	char *src = strndup(arg, sep - arg);
+	int ret = parse_addr(&q->proxy.src, src, "0");
+	if (ret != KNOT_EOK) {
+		ERR("invalid proxy source address '%s'", src);
+		free(src);
+		return KNOT_EINVAL;
+	}
+
+	const char *dst = sep + 1;
+	ret = parse_addr(&q->proxy.dst, dst, "53");
+	if (ret != KNOT_EOK) {
+		ERR("invalid proxy destination address '%s'", dst);
+		free(src);
+		return KNOT_EINVAL;
+	}
+
+	if (q->proxy.src.ss_family != q->proxy.dst.ss_family) {
+		ERR("proxy address family mismatch '%s' versus '%s'", src, dst);
+		free(src);
+		return KNOT_EINVAL;
+	}
+	free(src);
+
+	return KNOT_EOK;
+}
+
+static int opt_noproxy(const char *arg, void *query)
+{
+	query_t *q = query;
+
+	q->proxy.src.ss_family = 0;
+	q->proxy.dst.ss_family = 0;
+
+	return KNOT_EOK;
+}
+
+static const param_t kdig_opts2[] = {
+	{ "multiline",      ARG_NONE,     opt_multiline },
+	{ "nomultiline",    ARG_NONE,     opt_nomultiline },
+
+	{ "short",          ARG_NONE,     opt_short },
+	{ "noshort",        ARG_NONE,     opt_noshort },
+
+	{ "generic",        ARG_NONE,     opt_generic },
+	{ "nogeneric",      ARG_NONE,     opt_nogeneric },
+
+	{ "aaflag",         ARG_NONE,     opt_aaflag },
+	{ "noaaflag",       ARG_NONE,     opt_noaaflag },
+
+	{ "tcflag",         ARG_NONE,     opt_tcflag },
+	{ "notcflag",       ARG_NONE,     opt_notcflag },
+
+	{ "rdflag",         ARG_NONE,     opt_rdflag },
+	{ "nordflag",       ARG_NONE,     opt_nordflag },
+
+	{ "recurse",        ARG_NONE,     opt_rdflag },
+	{ "norecurse",      ARG_NONE,     opt_nordflag },
+
+	{ "raflag",         ARG_NONE,     opt_raflag },
+	{ "noraflag",       ARG_NONE,     opt_noraflag },
+
+	{ "zflag",          ARG_NONE,     opt_zflag },
+	{ "nozflag",        ARG_NONE,     opt_nozflag },
+
+	{ "adflag",         ARG_NONE,     opt_adflag },
+	{ "noadflag",       ARG_NONE,     opt_noadflag },
+
+	{ "cdflag",         ARG_NONE,     opt_cdflag },
+	{ "nocdflag",       ARG_NONE,     opt_nocdflag },
+
+	{ "dnssec",         ARG_NONE,     opt_doflag },
+	{ "nodnssec",       ARG_NONE,     opt_nodoflag },
+
+	{ "all",            ARG_NONE,     opt_all },
+	{ "noall",          ARG_NONE,     opt_noall },
+
+	{ "qr",             ARG_NONE,     opt_qr },
+	{ "noqr",           ARG_NONE,     opt_noqr },
+
+	{ "header",         ARG_NONE,     opt_header },
+	{ "noheader",       ARG_NONE,     opt_noheader },
+
+	{ "comments",       ARG_NONE,     opt_comments },
+	{ "nocomments",     ARG_NONE,     opt_nocomments },
+
+	{ "opt",            ARG_NONE,     opt_opt },
+	{ "noopt",          ARG_NONE,     opt_noopt },
+
+	{ "opttext",        ARG_NONE,     opt_opttext },
+	{ "noopttext",      ARG_NONE,     opt_noopttext },
+
+	{ "question",       ARG_NONE,     opt_question },
+	{ "noquestion",     ARG_NONE,     opt_noquestion },
+
+	{ "answer",         ARG_NONE,     opt_answer },
+	{ "noanswer",       ARG_NONE,     opt_noanswer },
+
+	{ "authority",      ARG_NONE,     opt_authority },
+	{ "noauthority",    ARG_NONE,     opt_noauthority },
+
+	{ "additional",     ARG_NONE,     opt_additional },
+	{ "noadditional",   ARG_NONE,     opt_noadditional },
+
+	{ "tsig",           ARG_NONE,     opt_tsig },
+	{ "notsig",         ARG_NONE,     opt_notsig },
+
+	{ "stats",          ARG_NONE,     opt_stats },
+	{ "nostats",        ARG_NONE,     opt_nostats },
+
+	{ "class",          ARG_NONE,     opt_class },
+	{ "noclass",        ARG_NONE,     opt_noclass },
+
+	{ "ttl",            ARG_NONE,     opt_ttl },
+	{ "nottl",          ARG_NONE,     opt_nottl },
+
+	{ "crypto",         ARG_NONE,     opt_crypto },
+	{ "nocrypto",       ARG_NONE,     opt_nocrypto },
+
+	{ "tcp",            ARG_NONE,     opt_tcp },
+	{ "notcp",          ARG_NONE,     opt_notcp },
+
+	{ "fastopen",       ARG_NONE,     opt_fastopen },
+	{ "nofastopen",     ARG_NONE,     opt_nofastopen },
+
+	{ "ignore",         ARG_NONE,     opt_ignore },
+	{ "noignore",       ARG_NONE,     opt_noignore },
+
+	{ "keepopen",       ARG_NONE,     opt_keepopen },
+	{ "nokeepopen",     ARG_NONE,     opt_nokeepopen },
+
+	{ "tls",            ARG_NONE,     opt_tls },
+	{ "notls",          ARG_NONE,     opt_notls },
+
+	{ "tls-ca",         ARG_OPTIONAL, opt_tls_ca },
+	{ "notls-ca",       ARG_NONE,     opt_notls_ca },
+
+	{ "tls-pin",        ARG_REQUIRED, opt_tls_pin },
+	{ "notls-pin",      ARG_NONE,     opt_notls_pin },
+
+	{ "tls-hostname",   ARG_REQUIRED, opt_tls_hostname },
+	{ "notls-hostname", ARG_NONE,     opt_notls_hostname },
+
+	{ "tls-sni",        ARG_REQUIRED, opt_tls_sni },
+	{ "notls-sni",      ARG_NONE,     opt_notls_sni },
+
+	{ "tls-keyfile",    ARG_REQUIRED, opt_tls_keyfile },
+	{ "notls-keyfile",  ARG_NONE,     opt_notls_keyfile },
+
+	{ "tls-certfile",   ARG_REQUIRED, opt_tls_certfile },
+	{ "notls-certfile", ARG_NONE,     opt_notls_certfile },
+
+	{ "tls-ocsp-stapling",   ARG_OPTIONAL, opt_tls_ocsp_stapling },
+	{ "notls-ocsp-stapling", ARG_NONE,     opt_notls_ocsp_stapling },
+
+	{ "https",          ARG_OPTIONAL, opt_https },
+	{ "nohttps",        ARG_NONE,     opt_nohttps },
+
+	{ "https-get",      ARG_NONE,     opt_https_get },
+	{ "nohttps-get",    ARG_NONE,     opt_nohttps_get },
+
+	{ "quic",           ARG_NONE,     opt_quic },
+	{ "noquic",         ARG_NONE,     opt_noquic },
+
+	{ "nsid",           ARG_NONE,     opt_nsid },
+	{ "nonsid",         ARG_NONE,     opt_nonsid },
+
+	{ "bufsize",        ARG_REQUIRED, opt_bufsize },
+	{ "nobufsize",      ARG_NONE,     opt_nobufsize },
+
+	{ "padding",        ARG_OPTIONAL, opt_padding },
+	{ "nopadding",      ARG_NONE,     opt_nopadding },
+
+	{ "alignment",      ARG_OPTIONAL, opt_alignment },
+	{ "noalignment",    ARG_NONE,     opt_noalignment },
+
+	{ "subnet",         ARG_REQUIRED, opt_subnet },
+	{ "nosubnet",       ARG_NONE,     opt_nosubnet },
+
+	{ "proxy",          ARG_REQUIRED, opt_proxy },
+	{ "noproxy",        ARG_NONE,     opt_noproxy },
+
+	// Obsolete aliases.
+	{ "client",         ARG_REQUIRED, opt_subnet },
+	{ "noclient",       ARG_NONE,     opt_nosubnet },
+
+	{ "edns",           ARG_OPTIONAL, opt_edns },
+	{ "noedns",         ARG_NONE,     opt_noedns },
+
+	{ "timeout",        ARG_REQUIRED, opt_timeout },
+	{ "notimeout",      ARG_NONE,     opt_notimeout },
+
+	{ "retry",          ARG_REQUIRED, opt_retry },
+	{ "noretry",        ARG_NONE,     opt_noretry },
+
+	{ "expire",         ARG_NONE,     opt_expire },
+	{ "noexpire",       ARG_NONE,     opt_noexpire },
+
+	{ "cookie",         ARG_OPTIONAL, opt_cookie },
+	{ "nocookie",       ARG_NONE,     opt_nocookie },
+
+	{ "badcookie",      ARG_NONE,     opt_badcookie },
+	{ "nobadcookie",    ARG_NONE,     opt_nobadcookie },
+
+	{ "ednsopt",        ARG_REQUIRED, opt_ednsopt },
+	{ "noednsopt",      ARG_NONE,     opt_noednsopt },
+
+	{ "json",           ARG_NONE,     opt_json },
+	{ "nojson",         ARG_NONE,     opt_nojson },
+
+	/* "idn" doesn't work since it must be called before query creation. */
+	{ "noidn",          ARG_NONE,     opt_noidn },
+
+	{ NULL }
+};
+
+query_t *query_create(const char *owner, const query_t *conf)
+{
+	// Create output structure.
+	query_t *query = calloc(1, sizeof(query_t));
+
+	if (query == NULL) {
+		DBG_NULL;
+		return NULL;
+	}
+
+	// Initialization with defaults or with reference query.
+	if (conf == NULL) {
+		query->conf = NULL;
+		query->local = NULL;
+		query->operation = OPERATION_QUERY;
+		query->ip = IP_ALL;
+		query->protocol = PROTO_ALL;
+		query->fastopen = false;
+		query->port = strdup("");
+		query->udp_size = -1;
+		query->retries = DEFAULT_RETRIES_DIG;
+		query->wait = DEFAULT_TIMEOUT_DIG;
+		query->ignore_tc = false;
+		query->class_num = -1;
+		query->type_num = -1;
+		query->serial = -1;
+		query->notify = false;
+		query->flags = DEFAULT_FLAGS_DIG;
+		query->style = DEFAULT_STYLE_DIG;
+		query->style.style.now = knot_time();
+		query->idn = true;
+		query->nsid = false;
+		query->edns = -1;
+		query->cc.len = 0;
+		query->sc.len = 0;
+		query->badcookie = BADCOOKIE_RETRY_MAX;
+		query->padding = -1;
+		query->alignment = 0;
+		tls_params_init(&query->tls);
+		//query->tsig_key
+		query->subnet.family = AF_UNSPEC;
+		ednsopt_list_init(&query->edns_opts);
+#if USE_DNSTAP
+		query->dt_reader = NULL;
+		query->dt_writer = NULL;
+#endif // USE_DNSTAP
+	} else {
+		*query = *conf;
+		query->conf = conf;
+		if (conf->local != NULL) {
+			query->local = srv_info_create(conf->local->name,
+			                               conf->local->service);
+			if (query->local == NULL) {
+				query_free(query);
+				return NULL;
+			}
+		} else {
+			query->local = NULL;
+		}
+		query->port = strdup(conf->port);
+		tls_params_copy(&query->tls, &conf->tls);
+		https_params_copy(&query->https, &conf->https);
+		quic_params_copy(&query->quic, &conf->quic);
+		if (conf->tsig_key.name != NULL) {
+			int ret = knot_tsig_key_copy(&query->tsig_key,
+			                             &conf->tsig_key);
+			if (ret != KNOT_EOK) {
+				query_free(query);
+				return NULL;
+			}
+		}
+
+		int ret = ednsopt_list_dup(&query->edns_opts, &conf->edns_opts);
+		if (ret != KNOT_EOK) {
+			query_free(query);
+			return NULL;
+		}
+
+#if USE_DNSTAP
+		query->dt_reader = conf->dt_reader;
+		query->dt_writer = conf->dt_writer;
+#endif // USE_DNSTAP
+	}
+
+	// Initialize list of servers.
+	init_list(&query->servers);
+
+	// Set the query owner if any.
+	if (owner != NULL) {
+		if ((query->owner = strdup(owner)) == NULL) {
+			query_free(query);
+			return NULL;
+		}
+	}
+
+	// Check dynamic allocation.
+	if (query->port == NULL) {
+		query_free(query);
+		return NULL;
+	}
+
+	return query;
+}
+
+void query_free(query_t *query)
+{
+	node_t *n, *nxt;
+
+	if (query == NULL) {
+		DBG_NULL;
+		return;
+	}
+
+	// Cleanup servers.
+	WALK_LIST_DELSAFE(n, nxt, query->servers) {
+		srv_info_free((srv_info_t *)n);
+	}
+
+	// Cleanup local address.
+	if (query->local != NULL) {
+		srv_info_free(query->local);
+	}
+
+	tls_params_clean(&query->tls);
+	https_params_clean(&query->https);
+	quic_params_clean(&query->quic);
+
+	// Cleanup signing key.
+	knot_tsig_key_deinit(&query->tsig_key);
+
+	// Cleanup EDNS options.
+	ednsopt_list_deinit(&query->edns_opts);
+
+#if USE_DNSTAP
+	if (query->dt_reader != NULL) {
+		dt_reader_free(query->dt_reader);
+	}
+	if (query->dt_writer != NULL) {
+		// Global writer can be shared!
+		if (query->conf == NULL ||
+		    query->conf->dt_writer != query->dt_writer) {
+			dt_writer_free(query->dt_writer);
+		}
+	}
+#endif // USE_DNSTAP
+
+	free(query->owner);
+	free(query->port);
+	free(query);
+}
+
+ednsopt_t *ednsopt_create(uint16_t code, uint16_t length, uint8_t *data)
+{
+	ednsopt_t *opt = calloc(1, sizeof(*opt));
+	if (opt == NULL) {
+		return NULL;
+	}
+
+	opt->code = code;
+	opt->length = length;
+	opt->data = data;
+
+	return opt;
+}
+
+ednsopt_t *ednsopt_dup(const ednsopt_t *opt)
+{
+	ednsopt_t *dup = calloc(1, sizeof(*opt));
+	if (dup == NULL) {
+		return NULL;
+	}
+
+	dup->code = opt->code;
+	dup->length = opt->length;
+	dup->data = memdup(opt->data, opt->length);
+	if (dup->data == NULL) {
+		free(dup);
+		return NULL;
+	}
+
+	return dup;
+}
+
+void ednsopt_free(ednsopt_t *opt)
+{
+	if (opt == NULL) {
+		return;
+	}
+
+	free(opt->data);
+	free(opt);
+}
+
+void ednsopt_list_init(list_t *list)
+{
+	init_list(list);
+}
+
+void ednsopt_list_deinit(list_t *list)
+{
+	node_t *n, *next;
+	WALK_LIST_DELSAFE(n, next, *list) {
+		ednsopt_t *opt = (ednsopt_t *)n;
+		ednsopt_free(opt);
+	}
+
+	init_list(list);
+}
+
+int ednsopt_list_dup(list_t *dest, const list_t *src)
+{
+	list_t backup = *dest;
+	init_list(dest);
+
+	node_t *n;
+	WALK_LIST(n, *src) {
+		ednsopt_t *opt = (ednsopt_t *)n;
+		ednsopt_t *dup = ednsopt_dup(opt);
+		if (dup == NULL) {
+			ednsopt_list_deinit(dest);
+			*dest = backup;
+			return KNOT_ENOMEM;
+		}
+
+		add_tail(dest, &dup->n);
+	}
+
+	return KNOT_EOK;
+}
+
+bool ednsopt_list_empty(const list_t *list)
+{
+	return EMPTY_LIST(*list);
+}
+
+int kdig_init(kdig_params_t *params)
+{
+	if (params == NULL) {
+		DBG_NULL;
+		return KNOT_EINVAL;
+	}
+
+	memset(params, 0, sizeof(*params));
+
+	params->stop = false;
+
+	// Initialize list of queries.
+	init_list(&params->queries);
+
+	// Create config query.
+	if ((params->config = query_create(NULL, NULL)) == NULL) {
+		return KNOT_ENOMEM;
+	}
+
+	return KNOT_EOK;
+}
+
+void kdig_clean(kdig_params_t *params)
+{
+	node_t *n, *nxt;
+
+	if (params == NULL) {
+		DBG_NULL;
+		return;
+	}
+
+	// Clean up queries.
+	WALK_LIST_DELSAFE(n, nxt, params->queries) {
+		query_free((query_t *)n);
+	}
+
+	// Clean up config.
+	query_free(params->config);
+
+	// Clean up the structure.
+	memset(params, 0, sizeof(*params));
+}
+
+static int parse_class(const char *value, query_t *query)
+{
+	uint16_t rclass;
+
+	if (params_parse_class(value, &rclass) != KNOT_EOK) {
+		return KNOT_EINVAL;
+	}
+
+	query->class_num = rclass;
+
+	return KNOT_EOK;
+}
+
+static int parse_keyfile(const char *value, query_t *query)
+{
+	knot_tsig_key_deinit(&query->tsig_key);
+
+	if (knot_tsig_key_init_file(&query->tsig_key, value) != KNOT_EOK) {
+		return KNOT_EINVAL;
+	}
+
+	return KNOT_EOK;
+}
+
+static int parse_local(const char *value, query_t *query)
+{
+	srv_info_t *local = parse_nameserver(value, "0");
+	if (local == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	if (query->local != NULL) {
+		srv_info_free(query->local);
+	}
+
+	query->local = local;
+
+	return KNOT_EOK;
+}
+
+static int parse_name(const char *value, list_t *queries, const query_t *conf)
+{
+	query_t	*query = NULL;
+	char	*ascii_name = (char *)value;
+	char	*fqd_name = NULL;
+
+	if (value != NULL) {
+		if (conf->idn) {
+			ascii_name = name_from_idn(value);
+			if (ascii_name == NULL) {
+				return KNOT_EINVAL;
+			}
+		}
+
+		// If name is not FQDN, append trailing dot.
+		fqd_name = get_fqd_name(ascii_name);
+
+		if (conf->idn) {
+			free(ascii_name);
+		}
+	}
+
+	// Create new query.
+	query = query_create(fqd_name, conf);
+
+	free(fqd_name);
+
+	if (query == NULL) {
+		return KNOT_ENOMEM;
+	}
+
+	// Add new query to the queries.
+	add_tail(queries, (node_t *)query);
+
+	return KNOT_EOK;
+}
+
+static int parse_port(const char *value, query_t *query)
+{
+	char **port;
+
+	// Set current server port (last or query default).
+	if (list_size(&query->servers) > 0) {
+		srv_info_t *server = TAIL(query->servers);
+		port = &(server->service);
+	} else {
+		port = &(query->port);
+	}
+
+	char *new_port = strdup(value);
+
+	if (new_port == NULL) {
+		return KNOT_ENOMEM;
+	}
+
+	// Deallocate old string.
+	free(*port);
+
+	*port = new_port;
+
+	return KNOT_EOK;
+}
+
+static int parse_reverse(const char *value, list_t *queries, const query_t *conf)
+{
+	query_t *query = NULL;
+
+	// Create reverse name.
+	char *reverse = get_reverse_name(value);
+
+	if (reverse == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	// Create reverse query for given address.
+	query = query_create(reverse, conf);
+
+	free(reverse);
+
+	if (query == NULL) {
+		return KNOT_ENOMEM;
+	}
+
+	// Set type for reverse query.
+	query->type_num = KNOT_RRTYPE_PTR;
+
+	// Add new query to the queries.
+	add_tail(queries, (node_t *)query);
+
+	return KNOT_EOK;
+}
+
+static int parse_server(const char *value, kdig_params_t *params)
+{
+	query_t *query;
+
+	// Set current query (last or config).
+	if (list_size(&params->queries) > 0) {
+		query = TAIL(params->queries);
+	} else {
+		query = params->config;
+	}
+
+	if (params_parse_server(value, &query->servers, query->port) != KNOT_EOK) {
+		ERR("invalid server @%s", value);
+		return KNOT_EINVAL;
+	}
+
+	return KNOT_EOK;
+}
+
+static int parse_tsig(const char *value, query_t *query)
+{
+	knot_tsig_key_deinit(&query->tsig_key);
+
+	if (knot_tsig_key_init_str(&query->tsig_key, value) != KNOT_EOK) {
+		return KNOT_EINVAL;
+	}
+
+	return KNOT_EOK;
+}
+
+static int parse_type(const char *value, query_t *query)
+{
+	uint16_t rtype;
+	int64_t  serial;
+	bool     notify;
+
+	if (params_parse_type(value, &rtype, &serial, &notify) != KNOT_EOK) {
+		return KNOT_EINVAL;
+	}
+
+	query->type_num = rtype;
+	query->serial = serial;
+	query->notify = notify;
+
+	// If NOTIFY, reset default RD flag.
+	if (query->notify) {
+		query->flags.rd_flag = false;
+	}
+
+	return KNOT_EOK;
+}
+
+#if USE_DNSTAP
+static int parse_dnstap_output(const char *value, query_t *query)
+{
+	if (query->dt_writer != NULL) {
+		if (query->conf == NULL ||
+		    query->conf->dt_writer != query->dt_writer) {
+			dt_writer_free(query->dt_writer);
+		}
+	}
+
+	query->dt_writer = dt_writer_create(value, "kdig " PACKAGE_VERSION);
+	if (query->dt_writer == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	return KNOT_EOK;
+}
+
+static int parse_dnstap_input(const char *value, query_t *query)
+{
+	// Just in case, shouldn't happen.
+	if (query->dt_reader != NULL) {
+		dt_reader_free(query->dt_reader);
+	}
+
+	query->dt_reader = dt_reader_create(value);
+	if (query->dt_reader == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	return KNOT_EOK;
+}
+#endif // USE_DNSTAP
+
+static void complete_servers(query_t *query, const query_t *conf)
+{
+	node_t *n;
+	char *def_port;
+
+	// Decide which default port use.
+	if (strlen(query->port) > 0) {
+		def_port = query->port;
+	} else if (strlen(conf->port) > 0) {
+		def_port = conf->port;
+	} else if (query->https.enable) {
+		def_port = DEFAULT_DNS_HTTPS_PORT;
+	} else if (query->quic.enable) {
+		def_port = DEFAULT_DNS_QUIC_PORT;
+	} else if (query->tls.enable) {
+		def_port = DEFAULT_DNS_TLS_PORT;
+	} else {
+		def_port = DEFAULT_DNS_PORT;
+	}
+
+	// Complete specified nameservers if any.
+	if (list_size(&query->servers) > 0) {
+		WALK_LIST(n, query->servers) {
+			srv_info_t *s = (srv_info_t *)n;
+
+			// If the port isn't specified yet use the default one.
+			if (strlen(s->service) == 0) {
+				free(s->service);
+				s->service = strdup(def_port);
+				if (s->service == NULL) {
+					WARN("can't set port %s", def_port);
+					return;
+				}
+			}
+
+			// Use server name as hostname for TLS if necessary.
+			if (query->tls.enable && query->tls.hostname == NULL &&
+			    (query->tls.system_ca || !EMPTY_LIST(query->tls.ca_files))) {
+				query->tls.hostname = strdup(s->name);
+			}
+		}
+	// Use servers from config if any.
+	} else if (list_size(&conf->servers) > 0) {
+		WALK_LIST(n, conf->servers) {
+			srv_info_t *s = (srv_info_t *)n;
+			char     *port = def_port;
+
+			// If the port is already specified, use it.
+			if (strlen(s->service) > 0) {
+				port = s->service;
+			}
+
+			srv_info_t *server = srv_info_create(s->name, port);
+			if (server == NULL) {
+				WARN("can't set nameserver %s port %s",
+				     s->name, s->service);
+				return;
+			}
+			add_tail(&query->servers, (node_t *)server);
+
+			// Use server name as hostname for TLS if necessary.
+			if (query->tls.enable && query->tls.hostname == NULL &&
+			    (query->tls.system_ca || !EMPTY_LIST(query->tls.ca_files))) {
+				query->tls.hostname = strdup(s->name);
+			}
+		}
+	// Use system specific.
+	} else {
+		get_nameservers(&query->servers, def_port);
+	}
+}
+
+static bool compare_servers(list_t *s1, list_t *s2)
+{
+	if (list_size(s1) != list_size(s2)) {
+		return false;
+	}
+
+	node_t *n1, *n2 = HEAD(*s2);
+	WALK_LIST(n1, *s1) {
+		srv_info_t *i1 = (srv_info_t *)n1, *i2 = (srv_info_t *)n2;
+		if (strcmp(i1->service, i2->service) != 0 ||
+		    strcmp(i1->name, i2->name) != 0)
+		{
+			return false;
+		}
+		n2 = n2->next;
+	}
+	return true;
+}
+
+void complete_queries(list_t *queries, const query_t *conf)
+{
+	node_t  *n;
+
+	if (queries == NULL || conf == NULL) {
+		DBG_NULL;
+		return;
+	}
+
+	// If there is no query, add default query: NS to ".".
+	if (list_size(queries) == 0) {
+		query_t *q = query_create(".", conf);
+		if (q == NULL) {
+			WARN("can't create query . NS IN");
+			return;
+		}
+		q->class_num = KNOT_CLASS_IN;
+		q->type_num = KNOT_RRTYPE_NS;
+		add_tail(queries, (node_t *)q);
+	}
+
+	WALK_LIST(n, *queries) {
+		query_t *q = (query_t *)n;
+		query_t *q_prev = (HEAD(*queries) != n) ? (query_t *)n->prev : NULL;
+
+		// Fill class number if missing.
+		if (q->class_num < 0) {
+			if (conf->class_num >= 0) {
+				q->class_num = conf->class_num;
+			} else {
+				q->class_num = KNOT_CLASS_IN;
+			}
+		}
+
+		// Fill type number if missing.
+		if (q->type_num < 0) {
+			if (conf->type_num >= 0) {
+				q->type_num = conf->type_num;
+				q->serial = conf->serial;
+			} else {
+				q->type_num = KNOT_RRTYPE_A;
+			}
+		}
+
+		// Set zone transfer if any.
+		if (q->type_num == KNOT_RRTYPE_AXFR ||
+		    q->type_num == KNOT_RRTYPE_IXFR) {
+			q->operation = OPERATION_XFR;
+		}
+
+		// No retries for TCP.
+		if (q->protocol == PROTO_TCP) {
+			q->retries = 0;
+		}
+
+		// Complete nameservers list.
+		complete_servers(q, conf);
+
+		// Check if using previous connection makes sense.
+		if (q_prev != NULL && q_prev->keepopen &&
+		    (get_socktype(q->protocol, q->type_num) !=
+		     get_socktype(q_prev->protocol, q_prev->type_num) ||
+		     q->https.enable != q_prev->https.enable ||
+		     q->tls.enable != q_prev->tls.enable ||
+		     strcmp(q->port, q_prev->port) != 0 ||
+		     !compare_servers(&q->servers, &q_prev->servers)))
+		{
+			WARN("connection parameters mismatch for query (%s), "
+			     "ignoring keepopen", q->owner);
+			q_prev->keepopen = false;
+		}
+	}
+}
+
+static void print_help(void)
+{
+	printf("Usage: %s [-4] [-6] [-d] [-b address] [-c class] [-p port]\n"
+	       "            [-q name] [-t type] [-x address] [-k keyfile]\n"
+	       "            [-y [algo:]keyname:key] [-E tapfile] [-G tapfile]\n"
+	       "            name [type] [class] [@server]\n"
+	       "\n"
+	       "       +[no]multiline             Wrap long records to more lines.\n"
+	       "       +[no]short                 Show record data only.\n"
+	       "       +[no]generic               Use generic representation format.\n"
+	       "       +[no]aaflag                Set AA flag.\n"
+	       "       +[no]tcflag                Set TC flag.\n"
+	       "       +[no]rdflag                Set RD flag.\n"
+	       "       +[no]recurse               Same as +[no]rdflag\n"
+	       "       +[no]raflag                Set RA flag.\n"
+	       "       +[no]zflag                 Set zero flag bit.\n"
+	       "       +[no]adflag                Set AD flag.\n"
+	       "       +[no]cdflag                Set CD flag.\n"
+	       "       +[no]dnssec                Set DO flag.\n"
+	       "       +[no]all                   Show all packet sections.\n"
+	       "       +[no]qr                    Show query packet.\n"
+	       "       +[no]header                Show packet header.\n"
+	       "       +[no]comments              Show commented section names.\n"
+	       "       +[no]opt                   Show EDNS pseudosection.\n"
+	       "       +[no]opttext               Try to show unknown EDNS options as text.\n"
+	       "       +[no]question              Show question section.\n"
+	       "       +[no]answer                Show answer section.\n"
+	       "       +[no]authority             Show authority section.\n"
+	       "       +[no]additional            Show additional section.\n"
+	       "       +[no]tsig                  Show TSIG pseudosection.\n"
+	       "       +[no]stats                 Show trailing packet statistics.\n"
+	       "       +[no]class                 Show DNS class.\n"
+	       "       +[no]ttl                   Show TTL value.\n"
+	       "       +[no]crypto                Show binary parts of RRSIGs and DNSKEYs.\n"
+	       "       +[no]tcp                   Use TCP protocol.\n"
+	       "       +[no]fastopen              Use TCP Fast Open.\n"
+	       "       +[no]ignore                Don't use TCP automatically if truncated.\n"
+	       "       +[no]keepopen              Don't close the TCP connection to be reused.\n"
+	       "       +[no]tls                   Use TLS with Opportunistic privacy profile.\n"
+	       "       +[no]tls-ca[=FILE]         Use TLS with Out-Of-Band privacy profile.\n"
+	       "       +[no]tls-pin=BASE64        Use TLS with pinned certificate.\n"
+	       "       +[no]tls-hostname=STR      Use TLS with remote server hostname.\n"
+	       "       +[no]tls-sni=STR           Use TLS with Server Name Indication.\n"
+	       "       +[no]tls-keyfile=FILE      Use TLS with a client keyfile.\n"
+	       "       +[no]tls-certfile=FILE     Use TLS with a client certfile.\n"
+	       "       +[no]tls-ocsp-stapling[=H] Use TLS with a valid stapled OCSP response for the\n"
+	       "                                  server certificate (%u or specify hours).\n"
+#ifdef LIBNGHTTP2
+	       "       +[no]https[=URL]           Use HTTPS protocol. It's also possible to specify\n"
+	       "                                  URL as [authority][/path] where query will be sent.\n"
+	       "       +[no]https-get             Use HTTPS protocol with GET method instead of POST.\n"
+#endif
+#ifdef ENABLE_QUIC
+	       "       +[no]quic                  Use QUIC protocol.\n"
+#endif
+	       "       +[no]nsid                  Request NSID.\n"
+	       "       +[no]bufsize=B             Set EDNS buffer size.\n"
+	       "       +[no]padding[=N]           Pad with EDNS(0) (default or specify size).\n"
+	       "       +[no]alignment[=N]         Pad with EDNS(0) to blocksize (%u or specify size).\n"
+	       "       +[no]subnet=SUBN           Set EDNS(0) client subnet addr/prefix.\n"
+	       "       +[no]edns[=N]              Use EDNS(=version).\n"
+	       "       +[no]timeout=T             Set wait for reply interval in seconds.\n"
+	       "       +[no]retry=N               Set number of retries.\n"
+	       "       +[no]expire                Set the EXPIRE EDNS option.\n"
+	       "       +[no]cookie[=HEX]          Attach EDNS(0) cookie to the query.\n"
+	       "       +[no]badcookie             Repeat a query with the correct cookie.\n"
+	       "       +[no]ednsopt=CODE[:HEX]    Set custom EDNS option.\n"
+	       "       +[no]proxy=SADDR-DADDR     Add PROXYv2 header with src and dest addresses.\n"
+	       "       +[no]json                  Use JSON for output encoding (RFC 8427).\n"
+	       "       +noidn                     Disable IDN transformation.\n"
+	       "\n"
+	       "       -h, --help                 Print the program help.\n"
+	       "       -V, --version              Print the program version.\n",
+	       PROGRAM_NAME, DEFAULT_TLS_OCSP_STAPLING / 3600, DEFAULT_ALIGNMENT_SIZE);
+}
+
+static int parse_opt1(const char *opt, const char *value, kdig_params_t *params,
+                      int *index)
+{
+	const char *val = value;
+	size_t     len = strlen(opt);
+	int        add = 1;
+	query_t    *query;
+
+	// Set current query (last or config).
+	if (list_size(&params->queries) > 0) {
+		query = TAIL(params->queries);
+	} else {
+		query = params->config;
+	}
+
+	// If there is no space between option and argument.
+	if (len > 1) {
+		val = opt + 1;
+		add = 0;
+	}
+
+	switch (opt[0]) {
+	case '4':
+		if (len > 1) {
+			ERR("invalid option -%s", opt);
+			return KNOT_ENOTSUP;
+		}
+
+		query->ip = IP_4;
+		break;
+	case '6':
+		if (len > 1) {
+			ERR("invalid option -%s", opt);
+			return KNOT_ENOTSUP;
+		}
+
+		query->ip = IP_6;
+		break;
+	case 'b':
+		if (val == NULL) {
+			ERR("missing address");
+			return KNOT_EINVAL;
+		}
+
+		if (parse_local(val, query) != KNOT_EOK) {
+			ERR("bad address %s", val);
+			return KNOT_EINVAL;
+		}
+		*index += add;
+		break;
+	case 'd':
+		msg_enable_debug(1);
+		break;
+	case 'h':
+		if (len > 1) {
+			ERR("invalid option -%s", opt);
+			return KNOT_ENOTSUP;
+		}
+
+		print_help();
+		params->stop = true;
+		break;
+	case 'c':
+		if (val == NULL) {
+			ERR("missing class");
+			return KNOT_EINVAL;
+		}
+
+		if (parse_class(val, query) != KNOT_EOK) {
+			ERR("bad class %s", val);
+			return KNOT_EINVAL;
+		}
+		*index += add;
+		break;
+	case 'k':
+		if (val == NULL) {
+			ERR("missing filename");
+			return KNOT_EINVAL;
+		}
+
+		if (parse_keyfile(val, query) != KNOT_EOK) {
+			ERR("bad keyfile %s", value);
+			return KNOT_EINVAL;
+		}
+		*index += add;
+		break;
+	case 'p':
+		if (val == NULL) {
+			ERR("missing port");
+			return KNOT_EINVAL;
+		}
+
+		if (parse_port(val, query) != KNOT_EOK) {
+			ERR("bad port %s", value);
+			return KNOT_EINVAL;
+		}
+		*index += add;
+		break;
+	case 'q':
+		// Allow empty QNAME.
+		if (parse_name(val, &params->queries, params->config)
+		    != KNOT_EOK) {
+			ERR("bad query name %s", val);
+			return KNOT_EINVAL;
+		}
+		*index += add;
+		break;
+	case 't':
+		if (val == NULL) {
+			ERR("missing type");
+			return KNOT_EINVAL;
+		}
+
+		if (parse_type(val, query) != KNOT_EOK) {
+			ERR("bad type %s", val);
+			return KNOT_EINVAL;
+		}
+		*index += add;
+		break;
+	case 'V':
+		if (len > 1) {
+			ERR("invalid option -%s", opt);
+			return KNOT_ENOTSUP;
+		}
+
+		print_version(PROGRAM_NAME);
+		params->stop = true;
+		break;
+	case 'x':
+		if (val == NULL) {
+			ERR("missing address");
+			return KNOT_EINVAL;
+		}
+
+		if (parse_reverse(val, &params->queries, params->config)
+		    != KNOT_EOK) {
+			ERR("bad reverse name %s", val);
+			return KNOT_EINVAL;
+		}
+		*index += add;
+		break;
+	case 'y':
+		if (val == NULL) {
+			ERR("missing key");
+			return KNOT_EINVAL;
+		}
+
+		if (parse_tsig(val, query) != KNOT_EOK) {
+			ERR("bad key %s", value);
+			return KNOT_EINVAL;
+		}
+		*index += add;
+		break;
+	case 'E':
+#if USE_DNSTAP
+		if (val == NULL) {
+			ERR("missing filename");
+			return KNOT_EINVAL;
+		}
+
+		if (parse_dnstap_output(val, query) != KNOT_EOK) {
+			ERR("unable to open dnstap output file %s", val);
+			return KNOT_EINVAL;
+		}
+		*index += add;
+#else
+		ERR("no dnstap support but -E specified");
+		return KNOT_EINVAL;
+#endif // USE_DNSTAP
+		break;
+	case 'G':
+#if USE_DNSTAP
+		if (val == NULL) {
+			ERR("missing filename");
+			return KNOT_EINVAL;
+		}
+
+		query = query_create(NULL, params->config);
+		if (query == NULL) {
+			return KNOT_ENOMEM;
+		}
+
+		if (parse_dnstap_input(val, query) != KNOT_EOK) {
+			ERR("unable to open dnstap input file %s", val);
+			query_free(query);
+			return KNOT_EINVAL;
+		}
+
+		query->operation = OPERATION_LIST_DNSTAP;
+		add_tail(&params->queries, (node_t *)query);
+
+		*index += add;
+#else
+		ERR("no dnstap support but -G specified");
+		return KNOT_EINVAL;
+#endif // USE_DNSTAP
+		break;
+	case '-':
+		if (strcmp(opt, "-help") == 0) {
+			print_help();
+			params->stop = true;
+		} else if (strcmp(opt, "-version") == 0) {
+			print_version(PROGRAM_NAME);
+			params->stop = true;
+		} else {
+			ERR("invalid option: -%s", opt);
+			return KNOT_ENOTSUP;
+		}
+		break;
+	default:
+		ERR("invalid option: -%s", opt);
+		return KNOT_ENOTSUP;
+	}
+
+	return KNOT_EOK;
+}
+
+static int parse_opt2(const char *value, kdig_params_t *params)
+{
+	query_t *query;
+
+	// Set current query (last or config).
+	if (list_size(&params->queries) > 0) {
+		query = TAIL(params->queries);
+	} else {
+		query = params->config;
+	}
+
+	// Get option name.
+	const char *arg_sep = "=";
+	size_t opt_len = strcspn(value, arg_sep);
+	if (opt_len < 1) {
+		ERR("invalid option: +%s", value);
+		return KNOT_ENOTSUP;
+	}
+
+	// Get option argument if any.
+	const char *arg = NULL;
+	const char *rest = value + opt_len;
+	if (strlen(rest) > 0) {
+		arg = rest + strspn(rest, arg_sep);
+	}
+
+	// Check if the given option is supported.
+	bool unique;
+	int ret = best_param(value, opt_len, kdig_opts2, &unique);
+	if (ret < 0) {
+		ERR("invalid option: +%s", value);
+		return KNOT_ENOTSUP;
+	} else if (!unique) {
+		ERR("ambiguous option: +%s", value);
+		return KNOT_ENOTSUP;
+	}
+
+	// Check argument presence.
+	switch (kdig_opts2[ret].arg) {
+	case ARG_NONE:
+		if (arg != NULL && *arg != '\0') {
+			WARN("superfluous option argument: +%s", value);
+		}
+		break;
+	case ARG_REQUIRED:
+		if (arg == NULL) {
+			ERR("missing argument: +%s", value);
+			return KNOT_EFEWDATA;
+		}
+		// FALLTHROUGH
+	case ARG_OPTIONAL:
+		if (arg != NULL && *arg == '\0') {
+			ERR("empty argument: +%s", value);
+			return KNOT_EFEWDATA;
+		}
+		break;
+	}
+
+	// Call option handler.
+	return kdig_opts2[ret].handler(arg, query);
+}
+
+static int parse_token(const char *value, kdig_params_t *params)
+{
+	query_t *query;
+
+	// Set current query (last or config).
+	if (list_size(&params->queries) > 0) {
+		query = TAIL(params->queries);
+	} else {
+		query = params->config;
+	}
+
+	// Try to guess the meaning of the token.
+	if (strlen(value) == 0) {
+		ERR("invalid empty parameter");
+	} else if (parse_type(value, query) == KNOT_EOK) {
+		return KNOT_EOK;
+	} else if (parse_class(value, query) == KNOT_EOK) {
+		return KNOT_EOK;
+	} else if (parse_name(value, &params->queries, params->config) == KNOT_EOK) {
+		return KNOT_EOK;
+	} else {
+		ERR("invalid parameter: %s", value);
+	}
+
+	return KNOT_EINVAL;
+}
+
+int kdig_parse(kdig_params_t *params, int argc, char *argv[])
+{
+	if (params == NULL || argv == NULL) {
+		DBG_NULL;
+		return KNOT_EINVAL;
+	}
+
+	// Initialize parameters.
+	if (kdig_init(params) != KNOT_EOK) {
+		return KNOT_ERROR;
+	}
+
+#ifdef LIBIDN
+	// Set up localization.
+	if (setlocale(LC_CTYPE, "") == NULL) {
+		WARN("can't setlocale, disabling IDN");
+		params->config->idn = false;
+		params->config->style.style.ascii_to_idn = NULL;
+	}
+#endif
+
+	// Command line parameters processing.
+	for (int i = 1; i < argc; i++) {
+		int ret = KNOT_ERROR;
+
+		// Process parameter.
+		switch (argv[i][0]) {
+		case '@':
+			ret = parse_server(argv[i] + 1, params);
+			break;
+		case '-':
+			ret = parse_opt1(argv[i] + 1, argv[i + 1], params, &i);
+			break;
+		case '+':
+			ret = parse_opt2(argv[i] + 1, params);
+			break;
+		default:
+			ret = parse_token(argv[i], params);
+			break;
+		}
+
+		// Check return.
+		switch (ret) {
+		case KNOT_EOK:
+			if (params->stop) {
+				return KNOT_EOK;
+			}
+			break;
+		case KNOT_ENOTSUP:
+			print_help();
+		default: // Fall through.
+			return ret;
+		}
+	}
+
+	// Complete missing data in queries based on defaults.
+	complete_queries(&params->queries, params->config);
+
+	return KNOT_EOK;
+}
diff --git a/src/utils/kdig/kdig_params.h b/src/utils/kdig/kdig_params.h
new file mode 100644
index 0000000..03aafe3
--- /dev/null
+++ b/src/utils/kdig/kdig_params.h
@@ -0,0 +1,187 @@
+/*  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/>.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+
+#include "utils/common/params.h"
+#include "utils/common/exec.h"
+#include "utils/common/https.h"
+#include "utils/common/quic.h"
+#include "utils/common/sign.h"
+#include "libknot/libknot.h"
+#include "contrib/sockaddr.h"
+
+#if USE_DNSTAP
+# include "contrib/dnstap/reader.h"
+# include "contrib/dnstap/writer.h"
+#endif // USE_DNSTAP
+
+/*! \brief Operation mode of kdig. */
+typedef enum {
+	/*!< Standard 1-message query/reply. */
+	OPERATION_QUERY,
+	/*!< Zone transfer (AXFR or IXFR). */
+	OPERATION_XFR,
+	/*!< Dump dnstap file. */
+	OPERATION_LIST_DNSTAP,
+} operation_t;
+
+/*! \brief DNS header and EDNS flags. */
+typedef struct {
+	/*!< Authoritative answer flag. */
+	bool	aa_flag;
+	/*!< Truncated flag. */
+	bool	tc_flag;
+	/*!< Recursion desired flag. */
+	bool	rd_flag;
+	/*!< Recursion available flag. */
+	bool	ra_flag;
+	/*!< Z flag. */
+	bool	z_flag;
+	/*!< Authenticated data flag. */
+	bool	ad_flag;
+	/*!< Checking disabled flag. */
+	bool	cd_flag;
+	/*!< DNSSEC OK flag. */
+	bool	do_flag;
+} flags_t;
+
+/*! \brief Basic parameters for DNS query. */
+typedef struct query query_t; // Forward declaration due to configuration.
+struct query {
+	/*!< List node (for list container). */
+	node_t		n;
+	/*!< Reference to global config. */
+	const query_t	*conf;
+	/*!< Name to query on. */
+	char		*owner;
+	/*!< List of nameservers to query to. */
+	list_t		servers;
+	/*!< Local interface (optional). */
+	srv_info_t	*local;
+	/*!< Operation mode. */
+	operation_t	operation;
+	/*!< Version of ip protocol to use. */
+	ip_t		ip;
+	/*!< Protocol type (TCP, UDP) to use. */
+	protocol_t	protocol;
+	/*!< Use TCP Fast Open. */
+	bool		fastopen;
+	/*!< Keep TCP connection open. */
+	bool		keepopen;
+	/*!< Port/service to connect to. */
+	char		*port;
+	/*!< UDP buffer size (16unsigned + -1 uninitialized). */
+	int32_t		udp_size;
+	/*!< Number of UDP retries. */
+	uint32_t	retries;
+	/*!< Wait for network response in seconds (-1 means forever). */
+	int32_t		wait;
+	/*!< Ignore truncated response. */
+	bool		ignore_tc;
+	/*!< Class number (16unsigned + -1 uninitialized). */
+	int32_t		class_num;
+	/*!< Type number (16unsigned + -1 uninitialized). */
+	int32_t		type_num;
+	/*!< SOA serial for IXFR and NOTIFY (32unsigned + -1 uninitialized). */
+	int64_t		serial;
+	/*!< NOTIFY query. */
+	bool		notify;
+	/*!< Header flags. */
+	flags_t		flags;
+	/*!< Output settings. */
+	style_t		style;
+	/*!< IDN conversion. */
+	bool		idn;
+	/*!< Query for NSID. */
+	bool		nsid;
+	/*!< EDNS version (8unsigned + -1 uninitialized). */
+	int16_t		edns;
+	/*!< EDNS client cookie. */
+	knot_edns_cookie_t cc;
+	/*!< EDNS server cookie. */
+	knot_edns_cookie_t sc;
+	/*!< Repeat query after BADCOOKIE. */
+	int		badcookie;
+	/*!< EDNS0 padding (16unsigned + -1 ~ uninitialized, -2 ~ default, -3 ~ none). */
+	int32_t		padding;
+	/*!< Query alignment with EDNS0 padding (0 ~ uninitialized). */
+	uint16_t	alignment;
+	/*!< TLS parameters. */
+	tls_params_t	tls;
+	/*!< HTTPS parameters. */
+	https_params_t	https;
+	/*!< QUIC parameters. */
+	quic_params_t	quic;
+	/*!< Transaction signature. */
+	knot_tsig_key_t	tsig_key;
+	/*!< EDNS client subnet. */
+	knot_edns_client_subnet_t subnet;
+	/*!< Lits of custom EDNS options. */
+	list_t		edns_opts;
+	/*!< PROXYv2 source and destination address. */
+	struct {
+		struct sockaddr_storage src;
+		struct sockaddr_storage dst;
+	} proxy;
+#if USE_DNSTAP
+	/*!< Context for dnstap reader input. */
+	dt_reader_t	*dt_reader;
+	/*!< Context for dnstap writer output. */
+	dt_writer_t	*dt_writer;
+#endif // USE_DNSTAP
+};
+
+/*! \brief EDNS option data. */
+typedef struct {
+	/*! List node (for list container). */
+	node_t	n;
+	/*!< OPTION-CODE field. */
+	uint16_t code;
+	/*!< OPTION-LENGTH field. */
+	uint16_t length;
+	/*!< OPTION-DATA field. */
+	uint8_t *data;
+} ednsopt_t;
+
+/*! \brief Settings for kdig. */
+typedef struct {
+	/*!< Stop processing - just print help, version,... */
+	bool	stop;
+	/*!< List of DNS queries to process. */
+	list_t	queries;
+	/*!< Default settings for queries. */
+	query_t	*config;
+} kdig_params_t;
+
+query_t *query_create(const char *owner, const query_t *config);
+void query_free(query_t *query);
+void complete_queries(list_t *queries, const query_t *conf);
+
+ednsopt_t *ednsopt_create(uint16_t code, uint16_t length, uint8_t *data);
+ednsopt_t *ednsopt_dup(const ednsopt_t *opt);
+void ednsopt_free(ednsopt_t *opt);
+
+void ednsopt_list_init(list_t *list);
+void ednsopt_list_deinit(list_t *list);
+int ednsopt_list_dup(list_t *dst, const list_t *src);
+bool ednsopt_list_empty(const list_t *list);
+
+int kdig_init(kdig_params_t *params);
+int kdig_parse(kdig_params_t *params, int argc, char *argv[]);
+void kdig_clean(kdig_params_t *params);