Adding upstream version 2.7.6.upstream/2.7.6upstream

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

1 files changed, 2014 insertions, 0 deletions

diff --git a/src/libknot/rrset-dump.c b/src/libknot/rrset-dump.c
new file mode 100644
index 0000000..a1c410a
--- /dev/null
+++ b/src/libknot/rrset-dump.c
@@ -0,0 +1,2014 @@
+/*  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 <http://www.gnu.org/licenses/>.
+ */
+
+#include <arpa/inet.h>
+#include <inttypes.h>
+#include <math.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include "libdnssec/binary.h"
+#include "libdnssec/keytag.h"
+#include "libknot/attribute.h"
+#include "libknot/rrset-dump.h"
+#include "libknot/codes.h"
+#include "libknot/consts.h"
+#include "libknot/descriptor.h"
+#include "libknot/errcode.h"
+#include "libknot/lookup.h"
+#include "libknot/rrtype/rrsig.h"
+#include "libknot/wire.h"
+#include "contrib/base32hex.h"
+#include "contrib/base64.h"
+#include "contrib/ctype.h"
+#include "contrib/wire_ctx.h"
+
+#define RRSET_DUMP_LIMIT (2 * 1024 * 1024)
+
+#define TAB_WIDTH		8
+#define BLOCK_WIDTH		40
+#define BLOCK_INDENT		"\n\t\t\t\t"
+
+#define LOC_ZERO		2147483648	// 2^31
+
+/*! \brief macros with repetitive (mostly error-checking) code of methods from first section of this file */
+#define CHECK_PRET if (p->ret < 0) return;
+#define CHECK_INMAX(mininmax) if (p->in_max < (mininmax)) { p->ret = -1; return; }
+#define CHECK_RET_OUTMAX_SNPRINTF if (ret <= 0 || (size_t)ret >= p->out_max) { p->ret = -1; return; }
+#define STRING_TERMINATION if (p->out_max > 0) { *p->out = '\0'; } else { p->ret = -1; return; }
+#define FILL_IN_INPUT(pdata) if (memcpy(&(pdata), p->in, in_len) == NULL) { p->ret = -1; return; }
+#define CHECK_RET_POSITIVE if (ret <= 0) { p->ret = -1; return; }
+
+typedef struct {
+	const knot_dump_style_t *style;
+	const uint8_t *in;
+	size_t        in_max;
+	char          *out;
+	size_t        out_max;
+	size_t        total;
+	int           ret;
+} rrset_dump_params_t;
+
+_public_
+const knot_dump_style_t KNOT_DUMP_STYLE_DEFAULT = {
+	.wrap = false,
+	.show_class = false,
+	.show_ttl = true,
+	.verbose = false,
+	.original_ttl = true,
+	.empty_ttl = false,
+	.human_ttl = false,
+	.human_tmstamp = true,
+	.hide_crypto = false,
+	.ascii_to_idn = NULL
+};
+
+static void dump_string(rrset_dump_params_t *p, const char *str)
+{
+	CHECK_PRET
+
+	size_t in_len = strlen(str);
+
+	// Check input size (+ 1 termination).
+	if (in_len >= p->out_max) {
+		p->ret = -1;
+		return;
+	}
+
+	// Copy string including termination '\0'!
+	if (memcpy(p->out, str, in_len + 1) == NULL) {
+		p->ret = -1;
+		return;
+	}
+
+	// Fill in output.
+	p->out += in_len;
+	p->out_max -= in_len;
+	p->total += in_len;
+}
+
+static void wire_num8_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	uint8_t data = *(p->in);
+	size_t  in_len = sizeof(data);
+	size_t  out_len = 0;
+
+	CHECK_INMAX(in_len)
+
+	// Write number.
+	int ret = snprintf(p->out, p->out_max, "%u", data);
+	CHECK_RET_OUTMAX_SNPRINTF
+	out_len = ret;
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+}
+
+static void wire_num16_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	uint16_t data;
+	size_t   in_len = sizeof(data);
+	size_t   out_len = 0;
+
+	CHECK_INMAX(in_len)
+
+	// Fill in input data.
+	data = knot_wire_read_u16(p->in);
+
+	// Write number.
+	int ret = snprintf(p->out, p->out_max, "%u", data);
+	CHECK_RET_OUTMAX_SNPRINTF
+	out_len = ret;
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+}
+
+static void wire_num32_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	uint32_t data;
+	size_t   in_len = sizeof(data);
+	size_t   out_len = 0;
+
+	CHECK_INMAX(in_len)
+
+	// Fill in input data.
+	data = knot_wire_read_u32(p->in);
+
+	// Write number.
+	int ret = snprintf(p->out, p->out_max, "%u", data);
+	CHECK_RET_OUTMAX_SNPRINTF
+	out_len = ret;
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+}
+
+static void wire_num48_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	uint64_t data;
+	size_t   in_len = 6;
+	size_t   out_len = 0;
+
+	CHECK_INMAX(in_len)
+
+	// Fill in input data.
+	data = knot_wire_read_u48(p->in);
+
+	// Write number.
+	int ret = snprintf(p->out, p->out_max, "%"PRIu64"", data);
+	CHECK_RET_OUTMAX_SNPRINTF
+	out_len = ret;
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+}
+
+static void wire_ipv4_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	struct in_addr addr4;
+	size_t in_len = sizeof(addr4.s_addr);
+	size_t out_len = 0;
+
+	CHECK_INMAX(in_len)
+
+	FILL_IN_INPUT(addr4.s_addr)
+
+	// Write address.
+	if (inet_ntop(AF_INET, &addr4, p->out, p->out_max) == NULL) {
+		p->ret = -1;
+		return;
+	}
+	out_len = strlen(p->out);
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+}
+
+static void wire_ipv6_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	struct in6_addr addr6;
+	size_t in_len = sizeof(addr6.s6_addr);
+	size_t out_len = 0;
+
+	CHECK_INMAX(in_len)
+
+	FILL_IN_INPUT(addr6.s6_addr)
+
+	// Write address.
+	if (inet_ntop(AF_INET6, &addr6, p->out, p->out_max) == NULL) {
+		p->ret = -1;
+		return;
+	}
+	out_len = strlen(p->out);
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+}
+
+static void wire_type_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	char     type[32];
+	uint16_t data;
+	size_t   in_len = sizeof(data);
+	size_t   out_len = 0;
+
+	CHECK_INMAX(in_len)
+
+	FILL_IN_INPUT(data)
+
+	// Get record type name string.
+	int ret = knot_rrtype_to_string(ntohs(data), type, sizeof(type));
+	CHECK_RET_POSITIVE
+
+	// Write string.
+	ret = snprintf(p->out, p->out_max, "%s", type);
+	CHECK_RET_OUTMAX_SNPRINTF
+	out_len = ret;
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+}
+
+static int hex_encode(const uint8_t  *in,
+                      const uint32_t in_len,
+                      uint8_t        *out,
+                      const uint32_t out_len)
+{
+	static const char hex[] = "0123456789ABCDEF";
+
+	if (out_len < 2 * in_len) {
+		return -1;
+	}
+
+	for (uint32_t i = 0; i < in_len; i++) {
+		out[2 * i]     = hex[in[i] / 16];
+		out[2 * i + 1] = hex[in[i] % 16];
+	}
+
+	return 2 * in_len;
+}
+
+static int hex_encode_alloc(const uint8_t  *in,
+                            const uint32_t in_len,
+                            uint8_t        **out)
+{
+	uint32_t out_len = 2 * in_len;
+
+	// Allocating output buffer.
+	*out = malloc(out_len);
+
+	if (*out == NULL) {
+		return -1;
+	}
+
+	// Encoding data.
+	return hex_encode(in, in_len, *out, out_len);
+}
+
+static int num48_encode(const uint8_t  *in,
+                        const uint32_t in_len,
+                        uint8_t        *out,
+                        const uint32_t out_len)
+{
+	if (in_len != 6) {
+		return -1;
+	}
+
+	uint64_t data = knot_wire_read_u48(in);
+
+	int ret = snprintf((char *)out, out_len, "%"PRIu64"", data);
+	if (ret <= 0 || (size_t)ret >= out_len) {
+		return -1;
+	}
+
+	return ret;
+}
+
+typedef int (*encode_t)(const uint8_t *in, const uint32_t in_len,
+                        uint8_t *out, const uint32_t out_len);
+
+typedef int (*encode_alloc_t)(const uint8_t *in, const uint32_t in_len,
+                              uint8_t **out);
+
+static void wire_data_encode_to_str(rrset_dump_params_t *p,
+                                    encode_t enc, encode_alloc_t enc_alloc)
+{
+	CHECK_PRET
+
+	int    ret;
+	size_t in_len = p->in_max;
+
+	// One-line vs multi-line mode.
+	if (p->style->wrap == false) {
+		// Encode data directly to the output.
+		ret = enc(p->in, in_len, (uint8_t *)(p->out), p->out_max);
+		CHECK_RET_POSITIVE
+		size_t out_len = ret;
+
+		p->out += out_len;
+		p->out_max -= out_len;
+		p->total += out_len;
+	} else {
+		int     src_begin;
+		uint8_t *buf;
+
+		// Encode data to the temporary buffer.
+		ret = enc_alloc(p->in, in_len, &buf);
+		CHECK_RET_POSITIVE
+
+		// Loop which wraps base64 block in more lines.
+		for (src_begin = 0; src_begin < ret; src_begin += BLOCK_WIDTH) {
+			if (src_begin > 0) {
+				// Write indent block.
+				dump_string(p, BLOCK_INDENT);
+				if (p->ret < 0) {
+					free(buf);
+					return;
+				}
+			}
+
+			// Compute block length (the last one can be shorter).
+			int src_len = (ret - src_begin) < BLOCK_WIDTH ?
+			              (ret - src_begin) : BLOCK_WIDTH;
+
+			if ((size_t)src_len > p->out_max) {
+				free(buf);
+				p->ret = -1;
+				return;
+			}
+
+			// Write data block.
+			memcpy(p->out, buf + src_begin, src_len);
+
+			p->out += src_len;
+			p->out_max -= src_len;
+			p->total += src_len;
+		}
+
+		// Destroy temporary buffer.
+		free(buf);
+	}
+
+	STRING_TERMINATION
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+}
+
+static void wire_len_data_encode_to_str(rrset_dump_params_t *p,
+                                        encode_t            enc,
+                                        const size_t        len_len,
+                                        const bool          print_len,
+                                        const char          *empty_str)
+{
+	CHECK_PRET
+
+	size_t in_len;
+
+	// First len_len bytes are data length.
+	CHECK_INMAX(len_len)
+
+	// Read data length.
+	switch (len_len) {
+	case 1:
+		in_len = *(p->in);
+		break;
+	case 2:
+		in_len = knot_wire_read_u16(p->in);
+		break;
+	case 4:
+		in_len = knot_wire_read_u32(p->in);
+		break;
+	default:
+		p->ret = -1;
+		return;
+	}
+
+	// If required print data length.
+	if (print_len == true) {
+		switch (len_len) {
+		case 1:
+			wire_num8_to_str(p);
+			break;
+		case 2:
+			wire_num16_to_str(p);
+			break;
+		case 4:
+			wire_num32_to_str(p);
+			break;
+		}
+
+		CHECK_PRET
+
+		// If something follows, print one space character.
+		if (in_len > 0 || *empty_str != '\0') {
+			dump_string(p, " ");
+			CHECK_PRET
+		}
+	} else {
+		p->in += len_len;
+		p->in_max -= len_len;
+	}
+
+	if (in_len > 0) {
+		// Encode data directly to the output.
+		int ret = enc(p->in, in_len, (uint8_t *)(p->out), p->out_max);
+		CHECK_RET_POSITIVE
+		p->out += ret;
+		p->out_max -= ret;
+		p->total += ret;
+
+		STRING_TERMINATION
+
+		// Fill in output.
+		p->in += in_len;
+		p->in_max -= in_len;
+	} else if (*empty_str != '\0') {
+		dump_string(p, empty_str);
+		CHECK_PRET
+	}
+}
+
+static void wire_data_omit(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	const char *omit_message = "[omitted]";
+	const size_t omlen = strlen(omit_message);
+
+	if (p->out_max < omlen) {
+		p->ret = -1;
+		return;
+	}
+
+	memcpy(p->out, omit_message, omlen);
+	p->out += omlen;
+	p->out_max -= omlen;
+	p->total += omlen;
+
+	STRING_TERMINATION
+
+	p->in += p->in_max;
+	p->in_max = 0;
+}
+
+static void wire_dnskey_to_tag(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	int key_pos = -4; // we expect that key flags, 3 and algorithm
+	                  // have been already dumped
+
+	uint16_t key_tag = 0;
+	const dnssec_binary_t rdata_bin = {
+		.data = (uint8_t *)(p->in + key_pos),
+		.size = p->in_max - key_pos
+	};
+	dnssec_keytag(&rdata_bin, &key_tag);
+
+	int ret = snprintf(p->out, p->out_max, "[id = %hu]", key_tag);
+	CHECK_RET_OUTMAX_SNPRINTF
+
+	p->in += p->in_max;
+	p->in_max = 0;
+	p->out += ret;
+	p->out_max -= ret;
+	p->total += ret;
+}
+
+static void wire_unknown_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	int    ret;
+	size_t in_len = p->in_max;
+	size_t out_len = 0;
+
+	// Write unknown length header.
+	if (in_len > 0) {
+		ret = snprintf(p->out, p->out_max, "\\# %zu ", in_len);
+	} else {
+		ret = snprintf(p->out, p->out_max, "\\# 0");
+	}
+	CHECK_RET_OUTMAX_SNPRINTF
+	out_len = ret;
+
+	// Fill in output.
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+
+	// Write hex data if any.
+	if (in_len > 0) {
+		// If wrap mode wrap line.
+		if (p->style->wrap) {
+			dump_string(p, BLOCK_INDENT);
+			CHECK_PRET
+		}
+
+		wire_data_encode_to_str(p, &hex_encode, &hex_encode_alloc);
+		CHECK_PRET
+	}
+}
+
+static void wire_text_to_str(rrset_dump_params_t *p, bool quote, bool with_header)
+{
+	CHECK_PRET
+
+	size_t in_len = 0;
+
+	if (with_header) {
+		// First byte is string length.
+		CHECK_INMAX(1)
+		in_len = *(p->in);
+		p->in++;
+		p->in_max--;
+
+		// Check if the given length makes sense.
+		CHECK_INMAX(in_len)
+	} else {
+		in_len = p->in_max;
+	}
+
+	// Check if quotation can ever be disabled (parser protection fallback).
+	if (!quote) {
+		for (size_t i = 0; i < in_len; i++) {
+			if (p->in[i] == ' ') { // Other WS characters are encoded.
+				quote = true;
+				break;
+			}
+		}
+	}
+
+	// Opening quotation.
+	if (quote) {
+		dump_string(p, "\"");
+		CHECK_PRET
+	}
+
+	// Loop over all characters.
+	for (size_t i = 0; i < in_len; i++) {
+		uint8_t ch = p->in[i];
+
+		if (is_print(ch)) {
+			// For special character print leading slash.
+			if (ch == '\\' || ch == '"') {
+				dump_string(p, "\\");
+				CHECK_PRET
+			}
+
+			// Print text character.
+			if (p->out_max == 0) {
+				p->ret = -1;
+				return;
+			}
+
+			*p->out = ch;
+			p->out++;
+			p->out_max--;
+			p->total++;
+		} else {
+			// Unprintable character encode via \ddd notation.
+			int ret = snprintf(p->out, p->out_max,"\\%03u", ch);
+			CHECK_RET_OUTMAX_SNPRINTF
+
+			p->out += ret;
+			p->out_max -= ret;
+			p->total += ret;
+		}
+	}
+
+	// Closing quotation.
+	if (quote) {
+		dump_string(p, "\"");
+		CHECK_PRET
+	}
+
+	STRING_TERMINATION
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+}
+
+static void wire_timestamp_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	uint32_t data;
+	size_t   in_len = sizeof(data);
+	size_t   out_len = 0;
+	int      ret;
+
+	CHECK_INMAX(in_len)
+
+	FILL_IN_INPUT(data)
+
+	time_t timestamp = ntohl(data);
+
+	if (p->style->human_tmstamp) {
+		struct tm result;
+		// Write timestamp in YYYYMMDDhhmmss format.
+		ret = strftime(p->out, p->out_max, "%Y%m%d%H%M%S",
+		               gmtime_r(&timestamp, &result));
+		CHECK_RET_POSITIVE
+	} else {
+		// Write timestamp only.
+		ret = snprintf(p->out, p->out_max, "%u", ntohl(data));
+		CHECK_RET_OUTMAX_SNPRINTF
+	}
+	out_len = ret;
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+}
+
+static int time_to_human_str(char         *out,
+                             const size_t out_len,
+                             uint32_t     data)
+{
+	size_t   total_len = 0;
+	uint32_t num;
+	int      ret;
+
+#define tths_process(unit_name, unit_size) \
+	num = data / (unit_size); \
+	if (num > 0) { \
+		ret = snprintf(out + total_len, out_len - total_len, \
+		               "%u%s", num, (unit_name)); \
+		if (ret <= 0 || (size_t)ret >= out_len - total_len) { \
+			return -1; \
+		} \
+		total_len += ret; \
+		data -= num * (unit_size); \
+	}
+
+	tths_process("d", 86400);
+	tths_process("h", 3600);
+	tths_process("m", 60);
+	tths_process("s", 1);
+
+#undef tths_process
+
+	return total_len > 0 ? total_len : -1;
+}
+
+static void wire_ttl_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	uint32_t data;
+	size_t   in_len = sizeof(data);
+	size_t   out_len = 0;
+	int      ret;
+
+	CHECK_INMAX(in_len)
+
+	FILL_IN_INPUT(data)
+
+	if (p->style->human_ttl) {
+		// Write time in human readable format.
+		ret = time_to_human_str(p->out, p->out_max, ntohl(data));
+		CHECK_RET_POSITIVE
+	} else {
+		// Write timestamp only.
+		ret = snprintf(p->out, p->out_max, "%u", ntohl(data));
+		CHECK_RET_OUTMAX_SNPRINTF
+	}
+	out_len = ret;
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+}
+
+static void wire_bitmap_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	int    ret;
+	char   type[32];
+	size_t i = 0;
+	size_t in_len = p->in_max;
+	size_t out_len = 0;
+
+	// Loop over bitmap window array (can be empty).
+	while (i < in_len) {
+		// First byte is window number.
+		uint8_t win = p->in[i++];
+
+		// Check window length (length must follow).
+		if (i >= in_len) {
+			p->ret = -1;
+			return;
+		}
+
+		// Second byte is window length.
+		uint8_t bitmap_len = p->in[i++];
+
+		// Check window length (len bytes must follow).
+		if (i + bitmap_len > in_len) {
+			p->ret = -1;
+			return;
+		}
+
+		// Bitmap processing.
+		for (size_t j = 0; j < (bitmap_len * 8); j++) {
+			if ((p->in[i + j / 8] & (128 >> (j % 8))) != 0) {
+				uint16_t type_num = win * 256 + j;
+
+				ret = knot_rrtype_to_string(type_num, type, sizeof(type));
+				CHECK_RET_POSITIVE
+
+				// Print type name to type list.
+				if (out_len > 0) {
+					ret = snprintf(p->out, p->out_max,
+					               " %s", type);
+				} else {
+					ret = snprintf(p->out, p->out_max,
+					               "%s", type);
+				}
+				CHECK_RET_OUTMAX_SNPRINTF
+				out_len += ret;
+				p->out += ret;
+				p->out_max -= ret;
+			}
+		}
+
+		i += bitmap_len;
+	}
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->total += out_len;
+}
+
+static void wire_dname_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	size_t in_len = knot_dname_size(p->in);
+	size_t out_len = 0;
+
+	CHECK_INMAX(in_len)
+
+	// Write dname string.
+	if (p->style->ascii_to_idn == NULL) {
+		char *dname_str = knot_dname_to_str(p->out, p->in, p->out_max);
+		if (dname_str == NULL) {
+			p->ret = -1;
+			return;
+		}
+		out_len = strlen(dname_str);
+	} else {
+		char *dname_str = knot_dname_to_str_alloc(p->in);
+		p->style->ascii_to_idn(&dname_str);
+
+		int ret = snprintf(p->out, p->out_max, "%s", dname_str);
+		free(dname_str);
+		CHECK_RET_OUTMAX_SNPRINTF
+		out_len = ret;
+	}
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+}
+
+static void wire_apl_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	struct in_addr addr4;
+	struct in6_addr addr6;
+	int    ret;
+	size_t out_len = 0;
+
+	// Input check: family(2B) + prefix(1B) + afdlen(1B).
+	CHECK_INMAX(4)
+
+	// Read fixed size values.
+	uint16_t family   = knot_wire_read_u16(p->in);
+	uint8_t  prefix   = *(p->in + 2);
+	uint8_t  negation = *(p->in + 3) >> 7;
+	uint8_t  afdlen   = *(p->in + 3) & 0x7F;
+	p->in += 4;
+	p->in_max -= 4;
+
+	// Write negation mark.
+	if (negation != 0) {
+		dump_string(p, "!");
+		CHECK_PRET
+	}
+
+	// Write address family with colon.
+	ret = snprintf(p->out, p->out_max, "%u:", family);
+	CHECK_RET_OUTMAX_SNPRINTF
+	p->out += ret;
+	p->out_max -= ret;
+	p->total += ret;
+
+	// Write address.
+	switch (family) {
+	case 1:
+		memset(&addr4, 0, sizeof(addr4));
+
+		if (afdlen > sizeof(addr4.s_addr) || afdlen > p->in_max) {
+			p->ret = -1;
+			return;
+		}
+
+		if (memcpy(&(addr4.s_addr), p->in, afdlen) == NULL) {
+			p->ret = -1;
+			return;
+		}
+
+		// Write address.
+		if (inet_ntop(AF_INET, &addr4, p->out, p->out_max) == NULL) {
+			p->ret = -1;
+			return;
+		}
+		out_len = strlen(p->out);
+
+		break;
+	case 2:
+		memset(&addr6, 0, sizeof(addr6));
+
+		if (afdlen > sizeof(addr6.s6_addr) || afdlen > p->in_max) {
+			p->ret = -1;
+			return;
+		}
+
+		if (memcpy(&(addr6.s6_addr), p->in, afdlen) == NULL) {
+			p->ret = -1;
+			return;
+		}
+
+		// Write address.
+		if (inet_ntop(AF_INET6, &addr6, p->out, p->out_max) == NULL) {
+			p->ret = -1;
+			return;
+		}
+		out_len = strlen(p->out);
+
+		break;
+	default:
+		p->ret = -1;
+		return;
+	}
+	p->in += afdlen;
+	p->in_max -= afdlen;
+	p->out += out_len;
+	p->out_max -= out_len;
+	p->total += out_len;
+
+	// Write prefix length with forward slash.
+	ret = snprintf(p->out, p->out_max, "/%u", prefix);
+	CHECK_RET_OUTMAX_SNPRINTF
+	p->out += ret;
+	p->out_max -= ret;
+	p->total += ret;
+}
+
+static void wire_loc_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	// Read values.
+	wire_ctx_t wire = wire_ctx_init_const(p->in, p->in_max);
+	uint8_t version = wire_ctx_read_u8(&wire);
+
+	// Version check.
+	if (version != 0) {
+		wire_unknown_to_str(p);
+		p->ret = -1;
+		return;
+	}
+
+	// Continue to read values.
+	uint8_t size_w = wire_ctx_read_u8(&wire);
+	uint8_t hpre_w = wire_ctx_read_u8(&wire);
+	uint8_t vpre_w = wire_ctx_read_u8(&wire);
+	uint32_t lat_w = wire_ctx_read_u32(&wire);
+	uint32_t lon_w = wire_ctx_read_u32(&wire);
+	uint32_t alt_w = wire_ctx_read_u32(&wire);
+
+	// Check if all reads are correct.
+	if (wire.error != KNOT_EOK) {
+		p->ret = -1;
+		return;
+	}
+
+	p->in += wire_ctx_offset(&wire);
+	p->in_max = wire_ctx_available(&wire);
+
+	// Latitude calculation.
+	char lat_mark;
+	uint32_t lat;
+	if (lat_w >= LOC_ZERO) {
+		lat_mark = 'N';
+		lat = lat_w - LOC_ZERO;
+	} else {
+		lat_mark = 'S';
+		lat = LOC_ZERO - lat_w;
+	}
+
+	uint32_t d1 = lat / 3600000;
+	uint32_t m1 = (lat - 3600000 * d1) / 60000;
+	double s1 = 0.001 * (lat - 3600000 * d1 - 60000 * m1);
+
+	// Longitude calculation.
+	char lon_mark;
+	uint32_t lon;
+	if (lon_w >= LOC_ZERO) {
+		lon_mark = 'E';
+		lon = lon_w - LOC_ZERO;
+	} else {
+		lon_mark = 'W';
+		lon = LOC_ZERO - lon_w;
+	}
+
+	uint32_t d2 = lon / 3600000;
+	uint32_t m2 = (lon - 3600000 * d2) / 60000;
+	double s2 = 0.001 * (lon - 3600000 * d2 - 60000 * m2);
+
+	// Write latitude and longitude.
+	int ret = snprintf(p->out, p->out_max, "%u %u %.*f %c  %u %u %.*f %c",
+	                   d1, m1, (uint32_t)s1 != s1 ? 3 : 0, s1, lat_mark,
+	                   d2, m2, (uint32_t)s2 != s2 ? 3 : 0, s2, lon_mark);
+	CHECK_RET_OUTMAX_SNPRINTF
+	p->out += ret;
+	p->out_max -= ret;
+	p->total += ret;
+
+	// Altitude calculation.
+	double alt = 0.01 * alt_w - 100000.0;
+
+	// Compute mantisa and exponent for each size.
+	uint8_t size_m = size_w >> 4;
+	uint8_t size_e = size_w & 0xF;
+	uint8_t hpre_m = hpre_w >> 4;
+	uint8_t hpre_e = hpre_w & 0xF;
+	uint8_t vpre_m = vpre_w >> 4;
+	uint8_t vpre_e = vpre_w & 0xF;
+
+	// Sizes check.
+	if (size_m > 9 || size_e > 9 || hpre_m > 9 || hpre_e > 9 ||
+	    vpre_m > 9 || vpre_e > 9) {
+		p->ret = -1;
+		return;
+	}
+
+	// Size and precisions calculation.
+	double size = 0.01 * size_m * pow(10, size_e);
+	double hpre = 0.01 * hpre_m * pow(10, hpre_e);
+	double vpre = 0.01 * vpre_m * pow(10, vpre_e);
+
+	// Write altitude and precisions.
+	ret = snprintf(p->out, p->out_max, "  %.*fm  %.*fm %.*fm %.*fm",
+	               (int32_t)alt != alt ? 2 : 0, alt,
+	               (uint32_t)size != size ? 2 : 0, size,
+	               (uint32_t)hpre != hpre ? 2 : 0, hpre,
+	               (uint32_t)vpre != vpre ? 2 : 0, vpre);
+	CHECK_RET_OUTMAX_SNPRINTF
+	p->out += ret;
+	p->out_max -= ret;
+	p->total += ret;
+}
+
+static void wire_gateway_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	// Input check: type(1B) + algo(1B).
+	CHECK_INMAX(2)
+
+	uint8_t type = *p->in;
+	uint8_t alg = *(p->in + 1);
+
+	// Write gateway type.
+	wire_num8_to_str(p);
+	CHECK_PRET
+
+	// Write space.
+	dump_string(p, " ");
+	CHECK_PRET
+
+	// Write algorithm number.
+	wire_num8_to_str(p);
+	CHECK_PRET
+
+	// Write space.
+	dump_string(p, " ");
+	CHECK_PRET
+
+	// Write appropriate gateway.
+	switch (type) {
+	case 0:
+		dump_string(p, ".");
+		break;
+	case 1:
+		wire_ipv4_to_str(p);
+		break;
+	case 2:
+		wire_ipv6_to_str(p);
+		break;
+	case 3:
+		wire_dname_to_str(p);
+		break;
+	default:
+		p->ret = -1;
+	}
+	CHECK_PRET
+
+	if (alg > 0) {
+		// If wrap mode wrap line.
+		if (p->style->wrap) {
+			dump_string(p, BLOCK_INDENT);
+		} else {
+			dump_string(p, " ");
+		}
+		CHECK_PRET
+
+		// Write ipsec key.
+		wire_data_encode_to_str(p, &base64_encode, &base64_encode_alloc);
+		CHECK_PRET
+	}
+}
+
+static void wire_l64_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	// Check input size (64-bit identifier).
+	if (p->in_max != 8) {
+		p->ret = -1;
+		return;
+	}
+
+	// Write identifier (2-byte) labels separated with a colon.
+	while (p->in_max > 0) {
+		int ret = hex_encode(p->in, 2, (uint8_t *)(p->out), p->out_max);
+		CHECK_RET_POSITIVE
+		p->in += 2;
+		p->in_max -= 2;
+		p->out += ret;
+		p->out_max -= ret;
+		p->total += ret;
+
+		// Write separation character.
+		if (p->in_max > 0) {
+			dump_string(p, ":");
+			CHECK_PRET
+		}
+	}
+}
+
+static void wire_eui_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	CHECK_INMAX(2)
+
+	// Write EUI hexadecimal pairs.
+	while (p->in_max > 0) {
+		int ret = hex_encode(p->in, 1, (uint8_t *)(p->out), p->out_max);
+		CHECK_RET_POSITIVE
+		p->in++;
+		p->in_max--;
+		p->out += ret;
+		p->out_max -= ret;
+		p->total += ret;
+
+		// Write separation character.
+		if (p->in_max > 0) {
+			dump_string(p, "-");
+			CHECK_PRET
+		}
+	}
+}
+
+static void wire_tsig_rcode_to_str(rrset_dump_params_t *p)
+{
+	CHECK_PRET
+
+	uint16_t data;
+	size_t   in_len = sizeof(data);
+	const char *rcode_str = "Unknown";
+
+	CHECK_INMAX(in_len)
+
+	// Fill in input data.
+	data = knot_wire_read_u16(p->in);
+
+	// Find RCODE name.
+	const knot_lookup_t *rcode = NULL;
+	rcode = knot_lookup_by_id(knot_tsig_rcode_names, data);
+	if (rcode == NULL) {
+		rcode = knot_lookup_by_id(knot_rcode_names, data);
+	}
+	if (rcode != NULL) {
+		rcode_str = rcode->name;
+	}
+
+	// Dump RCODE name.
+	dump_string(p, rcode_str);
+	CHECK_PRET
+
+	// Fill in output.
+	p->in += in_len;
+	p->in_max -= in_len;
+}
+
+static size_t dnskey_len(const uint8_t *rdata,
+                         const size_t  rdata_len)
+{
+	// Check for empty rdata and empty key.
+	if (rdata_len <= 4) {
+		return 0;
+	}
+
+	const uint8_t *key = rdata + 4;
+	const size_t  len = rdata_len - 4;
+
+	switch (rdata[3]) {
+	case KNOT_DNSSEC_ALG_DSA:
+	case KNOT_DNSSEC_ALG_DSA_NSEC3_SHA1:
+		// RFC 2536, key size ~ bit-length of 'modulus' P.
+		return (64 + 8 * key[0]) * 8;
+	case KNOT_DNSSEC_ALG_RSAMD5:
+	case KNOT_DNSSEC_ALG_RSASHA1:
+	case KNOT_DNSSEC_ALG_RSASHA1_NSEC3_SHA1:
+	case KNOT_DNSSEC_ALG_RSASHA256:
+	case KNOT_DNSSEC_ALG_RSASHA512:
+		// RFC 3110, key size ~ bit-length of 'modulus'.
+		if (key[0] == 0) {
+			if (len < 3) {
+				return 0;
+			}
+			uint16_t exp;
+			memcpy(&exp, key + 1, sizeof(uint16_t));
+			return (len - 3 - ntohs(exp)) * 8;
+		} else {
+			return (len - 1 - key[0]) * 8;
+		}
+	case KNOT_DNSSEC_ALG_ECC_GOST:
+		// RFC 5933, key size of GOST public keys MUST be 512 bits.
+		return 512;
+	case KNOT_DNSSEC_ALG_ECDSAP256SHA256:
+		// RFC 6605.
+		return 256;
+	case KNOT_DNSSEC_ALG_ECDSAP384SHA384:
+		// RFC 6605.
+		return 384;
+	case KNOT_DNSSEC_ALG_ED25519:
+		// RFC 8080.
+		return 256;
+	case KNOT_DNSSEC_ALG_ED448:
+		// RFC 8080.
+		return 456;
+	default:
+		return 0;
+	}
+}
+
+static void dnskey_info(const uint8_t *rdata,
+                        const size_t  rdata_len,
+                        char          *out,
+                        const size_t  out_len)
+{
+	// TODO: migrate key info to libdnssec
+
+	const uint8_t sep = *(rdata + 1) & 0x01;
+	uint16_t      key_tag = 0;
+	const size_t  key_len = dnskey_len(rdata, rdata_len);
+	const uint8_t alg_id = rdata[3];
+
+	const dnssec_binary_t rdata_bin = { .data = (uint8_t *)rdata,
+	                                    .size = rdata_len };
+	dnssec_keytag(&rdata_bin, &key_tag);
+
+	const knot_lookup_t *alg = NULL;
+	alg = knot_lookup_by_id(knot_dnssec_alg_names, alg_id);
+
+	int ret = snprintf(out, out_len, "%s, %s (%zub), id = %u",
+	                   sep ? "KSK" : "ZSK",
+	                   alg ? alg->name : "UNKNOWN",
+	                   key_len, key_tag );
+
+	if (ret <= 0) {	// Truncated return is acceptable. Just check for errors.
+		out[0] = '\0';
+	}
+}
+
+#define DUMP_PARAMS	rrset_dump_params_t *const p
+#define	DUMP_END	return (p->in_max == 0 ? (int)p->total : KNOT_EPARSEFAIL);
+
+#define CHECK_RET(p)	if (p->ret < 0) return p->ret;
+
+#define WRAP_INIT	dump_string(p, "(" BLOCK_INDENT); CHECK_RET(p);
+#define WRAP_END	dump_string(p, BLOCK_INDENT ")"); CHECK_RET(p);
+#define WRAP_LINE	dump_string(p, BLOCK_INDENT); CHECK_RET(p);
+
+#define COMMENT(s)	if (p->style->verbose) { \
+			    dump_string(p, " ; "); CHECK_RET(p); \
+			    dump_string(p, s); CHECK_RET(p); \
+			}
+
+#define DUMP_SPACE	dump_string(p, " "); CHECK_RET(p);
+#define DUMP_NUM8	wire_num8_to_str(p); CHECK_RET(p);
+#define DUMP_NUM16	wire_num16_to_str(p); CHECK_RET(p);
+#define DUMP_NUM32	wire_num32_to_str(p); CHECK_RET(p);
+#define DUMP_NUM48	wire_num48_to_str(p); CHECK_RET(p);
+#define DUMP_DNAME	wire_dname_to_str(p); CHECK_RET(p);
+#define DUMP_TIME	wire_ttl_to_str(p); CHECK_RET(p);
+#define DUMP_TIMESTAMP	wire_timestamp_to_str(p); CHECK_RET(p);
+#define DUMP_IPV4	wire_ipv4_to_str(p); CHECK_RET(p);
+#define DUMP_IPV6	wire_ipv6_to_str(p); CHECK_RET(p);
+#define DUMP_TYPE	wire_type_to_str(p); CHECK_RET(p);
+#define DUMP_HEX	wire_data_encode_to_str(p, &hex_encode, \
+				&hex_encode_alloc); CHECK_RET(p);
+#define DUMP_BASE64	wire_data_encode_to_str(p, &base64_encode, \
+				&base64_encode_alloc); CHECK_RET(p);
+#define DUMP_HASH	wire_len_data_encode_to_str(p, &base32hex_encode, \
+				1, false, ""); CHECK_RET(p);
+#define DUMP_SALT	wire_len_data_encode_to_str(p, &hex_encode, \
+				1, false, "-"); CHECK_RET(p);
+#define DUMP_TSIG_DGST	wire_len_data_encode_to_str(p, &base64_encode, \
+				2, true, ""); CHECK_RET(p);
+#define DUMP_TSIG_DATA	wire_len_data_encode_to_str(p, &num48_encode, \
+				2, true, ""); CHECK_RET(p);
+#define DUMP_OMIT	wire_data_omit(p); CHECK_RET(p);
+#define DUMP_KEY_OMIT	wire_dnskey_to_tag(p); CHECK_RET(p);
+#define DUMP_TEXT	wire_text_to_str(p, true, true); CHECK_RET(p);
+#define DUMP_LONG_TEXT	wire_text_to_str(p, true, false); CHECK_RET(p);
+#define DUMP_UNQUOTED	wire_text_to_str(p, false, true); CHECK_RET(p);
+#define DUMP_BITMAP	wire_bitmap_to_str(p); CHECK_RET(p);
+#define DUMP_APL	wire_apl_to_str(p); CHECK_RET(p);
+#define DUMP_LOC	wire_loc_to_str(p); CHECK_RET(p);
+#define DUMP_GATEWAY	wire_gateway_to_str(p); CHECK_RET(p);
+#define DUMP_L64	wire_l64_to_str(p); CHECK_RET(p);
+#define DUMP_EUI	wire_eui_to_str(p); CHECK_RET(p);
+#define DUMP_TSIG_RCODE	wire_tsig_rcode_to_str(p); CHECK_RET(p);
+#define DUMP_UNKNOWN	wire_unknown_to_str(p); CHECK_RET(p);
+
+static int dump_a(DUMP_PARAMS)
+{
+	DUMP_IPV4;
+
+	DUMP_END;
+}
+
+static int dump_ns(DUMP_PARAMS)
+{
+	DUMP_DNAME;
+
+	DUMP_END;
+}
+
+static int dump_soa(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		DUMP_DNAME; DUMP_SPACE;
+		DUMP_DNAME; DUMP_SPACE; WRAP_INIT;
+		DUMP_NUM32; COMMENT("serial"); WRAP_LINE;
+		DUMP_TIME;  COMMENT("refresh"); WRAP_LINE;
+		DUMP_TIME;  COMMENT("retry"); WRAP_LINE;
+		DUMP_TIME;  COMMENT("expire"); WRAP_LINE;
+		DUMP_TIME;  COMMENT("minimum"); WRAP_END;
+	} else {
+		DUMP_DNAME; DUMP_SPACE;
+		DUMP_DNAME; DUMP_SPACE;
+		DUMP_NUM32; DUMP_SPACE;
+		DUMP_TIME;  DUMP_SPACE;
+		DUMP_TIME;  DUMP_SPACE;
+		DUMP_TIME;  DUMP_SPACE;
+		DUMP_TIME;
+	}
+
+	DUMP_END;
+}
+
+static int dump_hinfo(DUMP_PARAMS)
+{
+	DUMP_TEXT; DUMP_SPACE;
+	DUMP_TEXT;
+
+	DUMP_END;
+}
+
+static int dump_minfo(DUMP_PARAMS)
+{
+	DUMP_DNAME; DUMP_SPACE;
+	DUMP_DNAME;
+
+	DUMP_END;
+}
+
+static int dump_mx(DUMP_PARAMS)
+{
+	DUMP_NUM16; DUMP_SPACE;
+	DUMP_DNAME;
+
+	DUMP_END;
+}
+
+static int dump_txt(DUMP_PARAMS)
+{
+	// First text string.
+	DUMP_TEXT;
+
+	// Other text strings if any.
+	while (p->in_max > 0) {
+		DUMP_SPACE; DUMP_TEXT;
+	}
+
+	DUMP_END;
+}
+
+static int dump_dnskey(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		char info[512] = "";
+		dnskey_info(p->in, p->in_max, info, sizeof(info));
+
+		DUMP_NUM16; DUMP_SPACE;
+		DUMP_NUM8;  DUMP_SPACE;
+		DUMP_NUM8;  DUMP_SPACE;
+		if (p->style->hide_crypto) {
+			DUMP_OMIT;
+			WRAP_LINE;
+		} else {
+			WRAP_INIT;
+			DUMP_BASE64;
+			WRAP_END;
+		}
+		COMMENT(info);
+	} else {
+		DUMP_NUM16; DUMP_SPACE;
+		DUMP_NUM8;  DUMP_SPACE;
+		DUMP_NUM8;  DUMP_SPACE;
+		if (p->style->hide_crypto) {
+			DUMP_KEY_OMIT;
+		} else {
+			DUMP_BASE64;
+		}
+	}
+
+	DUMP_END;
+}
+
+static int dump_aaaa(DUMP_PARAMS)
+{
+	DUMP_IPV6;
+
+	DUMP_END;
+}
+
+static int dump_loc(DUMP_PARAMS)
+{
+	DUMP_LOC;
+
+	DUMP_END;
+}
+
+static int dump_srv(DUMP_PARAMS)
+{
+	DUMP_NUM16; DUMP_SPACE;
+	DUMP_NUM16; DUMP_SPACE;
+	DUMP_NUM16; DUMP_SPACE;
+	DUMP_DNAME;
+
+	DUMP_END;
+}
+
+static int dump_naptr(DUMP_PARAMS)
+{
+	DUMP_NUM16; DUMP_SPACE;
+	DUMP_NUM16; DUMP_SPACE;
+	DUMP_TEXT;  DUMP_SPACE;
+	DUMP_TEXT;  DUMP_SPACE;
+	DUMP_TEXT;  DUMP_SPACE;
+	DUMP_DNAME;
+
+	DUMP_END;
+}
+
+static int dump_cert(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		DUMP_NUM16;  DUMP_SPACE;
+		DUMP_NUM16;  DUMP_SPACE;
+		DUMP_NUM8;   DUMP_SPACE; WRAP_INIT;
+		DUMP_BASE64;
+		WRAP_END;
+	} else {
+		DUMP_NUM16;  DUMP_SPACE;
+		DUMP_NUM16;  DUMP_SPACE;
+		DUMP_NUM8;   DUMP_SPACE;
+		DUMP_BASE64;
+	}
+
+	DUMP_END;
+}
+
+static int dump_apl(DUMP_PARAMS)
+{
+	// Print list of APLs (empty list is allowed).
+	while (p->in_max > 0) {
+		if (p->total > 0) {
+			DUMP_SPACE;
+		}
+		DUMP_APL;
+	}
+
+	DUMP_END;
+}
+
+static int dump_ds(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		DUMP_NUM16; DUMP_SPACE;
+		DUMP_NUM8;  DUMP_SPACE;
+		DUMP_NUM8;  DUMP_SPACE; WRAP_INIT;
+		DUMP_HEX;
+		WRAP_END;
+	} else {
+		DUMP_NUM16; DUMP_SPACE;
+		DUMP_NUM8;  DUMP_SPACE;
+		DUMP_NUM8;  DUMP_SPACE;
+		DUMP_HEX;
+	}
+
+	DUMP_END;
+}
+
+static int dump_sshfp(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		DUMP_NUM8; DUMP_SPACE;
+		DUMP_NUM8; DUMP_SPACE; WRAP_INIT;
+		DUMP_HEX;
+		WRAP_END;
+	} else {
+		DUMP_NUM8; DUMP_SPACE;
+		DUMP_NUM8; DUMP_SPACE;
+		DUMP_HEX;
+	}
+
+	DUMP_END;
+}
+
+static int dump_ipseckey(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		DUMP_NUM8; DUMP_SPACE; WRAP_INIT;
+		DUMP_GATEWAY;
+		WRAP_END;
+	} else {
+		DUMP_NUM8; DUMP_SPACE;
+		DUMP_GATEWAY;
+	}
+
+	DUMP_END;
+}
+
+static int dump_rrsig(DUMP_PARAMS)
+{
+	DUMP_TYPE;   DUMP_SPACE;
+	DUMP_NUM8;   DUMP_SPACE;
+	DUMP_NUM8;   DUMP_SPACE;
+	DUMP_NUM32;  DUMP_SPACE;
+	DUMP_TIMESTAMP; DUMP_SPACE;
+	if (p->style->wrap) {
+		WRAP_INIT;
+	}
+	DUMP_TIMESTAMP; DUMP_SPACE;
+	DUMP_NUM16;  DUMP_SPACE;
+	DUMP_DNAME;  DUMP_SPACE;
+	if (p->style->wrap) {
+		WRAP_LINE;
+	}
+	if (p->style->hide_crypto) {
+		DUMP_OMIT;
+	} else {
+		DUMP_BASE64;
+	}
+	if (p->style->wrap) {
+		WRAP_END;
+	}
+	DUMP_END;
+}
+
+static int dump_nsec(DUMP_PARAMS)
+{
+	DUMP_DNAME; DUMP_SPACE;
+	DUMP_BITMAP;
+
+	DUMP_END;
+}
+
+static int dump_dhcid(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		WRAP_INIT;
+		DUMP_BASE64;
+		WRAP_END;
+	} else {
+		DUMP_BASE64;
+	}
+
+	DUMP_END;
+}
+
+static int dump_nsec3(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		DUMP_NUM8;   DUMP_SPACE;
+		DUMP_NUM8;   DUMP_SPACE;
+		DUMP_NUM16;  DUMP_SPACE;
+		DUMP_SALT;   DUMP_SPACE; WRAP_INIT;
+		DUMP_HASH;   DUMP_SPACE; WRAP_LINE;
+		DUMP_BITMAP;
+		WRAP_END;
+	} else {
+		DUMP_NUM8;  DUMP_SPACE;
+		DUMP_NUM8;  DUMP_SPACE;
+		DUMP_NUM16; DUMP_SPACE;
+		DUMP_SALT;  DUMP_SPACE;
+		DUMP_HASH;  DUMP_SPACE;
+		DUMP_BITMAP;
+	}
+
+	DUMP_END;
+}
+
+static int dump_nsec3param(DUMP_PARAMS)
+{
+	DUMP_NUM8;  DUMP_SPACE;
+	DUMP_NUM8;  DUMP_SPACE;
+	DUMP_NUM16; DUMP_SPACE;
+	DUMP_SALT;
+
+	DUMP_END;
+}
+
+static int dump_tlsa(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		DUMP_NUM8; DUMP_SPACE;
+		DUMP_NUM8; DUMP_SPACE;
+		DUMP_NUM8; DUMP_SPACE; WRAP_INIT;
+		DUMP_HEX;
+		WRAP_END;
+	} else {
+		DUMP_NUM8; DUMP_SPACE;
+		DUMP_NUM8; DUMP_SPACE;
+		DUMP_NUM8; DUMP_SPACE;
+		DUMP_HEX;
+	}
+
+	DUMP_END;
+}
+
+static int dump_l64(DUMP_PARAMS)
+{
+	DUMP_NUM16; DUMP_SPACE;
+	DUMP_L64;
+
+	DUMP_END;
+}
+
+static int dump_l32(DUMP_PARAMS)
+{
+	DUMP_NUM16; DUMP_SPACE;
+	DUMP_IPV4;
+
+	DUMP_END;
+}
+
+static int dump_eui(DUMP_PARAMS)
+{
+	DUMP_EUI;
+
+	DUMP_END;
+}
+
+static int dump_tsig(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		DUMP_DNAME; DUMP_SPACE;
+		DUMP_NUM48; DUMP_SPACE;
+		DUMP_NUM16; DUMP_SPACE; WRAP_INIT;
+		DUMP_TSIG_DGST; DUMP_SPACE; WRAP_LINE;
+		DUMP_NUM16; DUMP_SPACE;
+		DUMP_TSIG_RCODE; DUMP_SPACE;
+		DUMP_TSIG_DATA;
+		WRAP_END;
+	} else {
+		DUMP_DNAME; DUMP_SPACE;
+		DUMP_NUM48; DUMP_SPACE;
+		DUMP_NUM16; DUMP_SPACE;
+		DUMP_TSIG_DGST; DUMP_SPACE;
+		DUMP_NUM16; DUMP_SPACE;
+		DUMP_TSIG_RCODE; DUMP_SPACE;
+		DUMP_TSIG_DATA;
+	}
+
+	DUMP_END;
+}
+
+static int dump_uri(DUMP_PARAMS)
+{
+	DUMP_NUM16;     DUMP_SPACE;
+	DUMP_NUM16;     DUMP_SPACE;
+	DUMP_LONG_TEXT; DUMP_SPACE;
+
+	DUMP_END;
+}
+
+static int dump_caa(DUMP_PARAMS)
+{
+	DUMP_NUM8;      DUMP_SPACE;
+	DUMP_UNQUOTED;  DUMP_SPACE;
+	DUMP_LONG_TEXT; DUMP_SPACE;
+
+	DUMP_END;
+}
+
+static int dump_unknown(DUMP_PARAMS)
+{
+	if (p->style->wrap) {
+		WRAP_INIT;
+		DUMP_UNKNOWN;
+		WRAP_END;
+	} else {
+		DUMP_UNKNOWN;
+	}
+
+	DUMP_END;
+}
+
+static int txt_dump_data(rrset_dump_params_t *p, uint16_t type)
+{
+	switch (type) {
+		case KNOT_RRTYPE_A:
+			return dump_a(p);
+		case KNOT_RRTYPE_NS:
+		case KNOT_RRTYPE_CNAME:
+		case KNOT_RRTYPE_PTR:
+		case KNOT_RRTYPE_DNAME:
+			return dump_ns(p);
+		case KNOT_RRTYPE_SOA:
+			return dump_soa(p);
+		case KNOT_RRTYPE_HINFO:
+			return dump_hinfo(p);
+		case KNOT_RRTYPE_MINFO:
+		case KNOT_RRTYPE_RP:
+			return dump_minfo(p);
+		case KNOT_RRTYPE_MX:
+		case KNOT_RRTYPE_AFSDB:
+		case KNOT_RRTYPE_RT:
+		case KNOT_RRTYPE_KX:
+		case KNOT_RRTYPE_LP:
+			return dump_mx(p);
+		case KNOT_RRTYPE_TXT:
+		case KNOT_RRTYPE_SPF:
+			return dump_txt(p);
+		case KNOT_RRTYPE_KEY:
+		case KNOT_RRTYPE_DNSKEY:
+		case KNOT_RRTYPE_CDNSKEY:
+			return dump_dnskey(p);
+		case KNOT_RRTYPE_AAAA:
+			return dump_aaaa(p);
+		case KNOT_RRTYPE_LOC:
+			return dump_loc(p);
+		case KNOT_RRTYPE_SRV:
+			return dump_srv(p);
+		case KNOT_RRTYPE_NAPTR:
+			return dump_naptr(p);
+		case KNOT_RRTYPE_CERT:
+			return dump_cert(p);
+		case KNOT_RRTYPE_APL:
+			return dump_apl(p);
+		case KNOT_RRTYPE_DS:
+		case KNOT_RRTYPE_CDS:
+			return dump_ds(p);
+		case KNOT_RRTYPE_SSHFP:
+			return dump_sshfp(p);
+		case KNOT_RRTYPE_IPSECKEY:
+			return dump_ipseckey(p);
+		case KNOT_RRTYPE_RRSIG:
+			return dump_rrsig(p);
+		case KNOT_RRTYPE_NSEC:
+			return dump_nsec(p);
+		case KNOT_RRTYPE_DHCID:
+			return dump_dhcid(p);
+		case KNOT_RRTYPE_NSEC3:
+			return dump_nsec3(p);
+		case KNOT_RRTYPE_NSEC3PARAM:
+			return dump_nsec3param(p);
+		case KNOT_RRTYPE_TLSA:
+			return dump_tlsa(p);
+		case KNOT_RRTYPE_NID:
+		case KNOT_RRTYPE_L64:
+			return dump_l64(p);
+		case KNOT_RRTYPE_L32:
+			return dump_l32(p);
+		case KNOT_RRTYPE_EUI48:
+		case KNOT_RRTYPE_EUI64:
+			return dump_eui(p);
+		case KNOT_RRTYPE_TSIG:
+			return dump_tsig(p);
+		case KNOT_RRTYPE_URI:
+			return dump_uri(p);
+		case KNOT_RRTYPE_CAA:
+			return dump_caa(p);
+		default:
+			return dump_unknown(p);
+	}
+}
+
+_public_
+int knot_rrset_txt_dump_data(const knot_rrset_t      *rrset,
+                             const size_t            pos,
+                             char                    *dst,
+                             const size_t            maxlen,
+                             const knot_dump_style_t *style)
+{
+	if (rrset == NULL || dst == NULL || style == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	knot_rdata_t *rr_data = knot_rdataset_at(&rrset->rrs, pos);
+	if (rr_data == NULL) {
+		return KNOT_EINVAL; /* bad pos or rrset->rrs */
+	}
+
+	uint8_t *data = rr_data->data;
+	uint16_t data_len = rr_data->len;
+
+	rrset_dump_params_t p = {
+		.style = style,
+		.in = data,
+		.in_max = data_len,
+		.out = dst,
+		.out_max = maxlen,
+		.total = 0,
+		.ret = 0
+	};
+
+	int ret;
+
+	// Allow empty rdata with the CH class (knsupdate).
+	if (data_len == 0 && rrset->rclass != KNOT_CLASS_IN) {
+		ret = 0;
+	} else if (style->generic) {
+		ret = dump_unknown(&p);
+	} else {
+		ret = txt_dump_data(&p, rrset->type);
+	}
+
+	// Terminate the string just in case.
+	if (ret < 0 || ret >= maxlen) {
+		return KNOT_ESPACE;
+	}
+	dst[ret] = '\0';
+
+	return ret;
+}
+
+#define SNPRINTF_CHECK(ret, max_len)			\
+	if ((ret) < 0 || (size_t)(ret) >= (max_len)) {	\
+		return KNOT_ESPACE;			\
+	}
+
+_public_
+int knot_rrset_txt_dump_header(const knot_rrset_t      *rrset,
+                               const uint32_t          ttl,
+                               char                    *dst,
+                               const size_t            maxlen,
+                               const knot_dump_style_t *style)
+{
+	if (rrset == NULL || dst == NULL || style == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	size_t len = 0;
+	char   buf[32];
+	int    ret;
+
+	// Dump rrset owner.
+	char *name = knot_dname_to_str_alloc(rrset->owner);
+	if (style->ascii_to_idn != NULL) {
+		style->ascii_to_idn(&name);
+	}
+	char sep = strlen(name) < 4 * TAB_WIDTH ? '\t' : ' ';
+	ret = snprintf(dst + len, maxlen - len, "%-20s%c", name, sep);
+	free(name);
+	SNPRINTF_CHECK(ret, maxlen - len);
+	len += ret;
+
+	// Set white space separation character.
+	sep = style->wrap ? ' ' : '\t';
+
+	// Dump rrset ttl.
+	if (style->show_ttl) {
+		if (style->empty_ttl) {
+			ret = snprintf(dst + len, maxlen - len, "%c", sep);
+		} else if (style->human_ttl) {
+			// Create human readable ttl string.
+			if (time_to_human_str(buf, sizeof(buf), ttl) < 0) {
+				return KNOT_ESPACE;
+			}
+			ret = snprintf(dst + len, maxlen - len, "%s%c",
+			               buf, sep);
+		} else {
+			ret = snprintf(dst + len, maxlen - len, "%u%c", ttl, sep);
+		}
+		SNPRINTF_CHECK(ret, maxlen - len);
+		len += ret;
+	}
+
+	// Dump rrset class.
+	if (style->show_class) {
+		if (knot_rrclass_to_string(rrset->rclass, buf, sizeof(buf)) < 0) {
+			return KNOT_ESPACE;
+		}
+		ret = snprintf(dst + len, maxlen - len, "%-2s%c", buf, sep);
+		SNPRINTF_CHECK(ret, maxlen - len);
+		len += ret;
+	}
+
+	// Dump rrset type.
+	if (style->generic) {
+		if (snprintf(buf, sizeof(buf), "TYPE%u", rrset->type) < 0) {
+			return KNOT_ESPACE;
+		}
+	} else if (knot_rrtype_to_string(rrset->type, buf, sizeof(buf)) < 0) {
+		return KNOT_ESPACE;
+	}
+	if (rrset->rrs.count > 0) {
+		ret = snprintf(dst + len, maxlen - len, "%s%c", buf, sep);
+	} else {
+		ret = snprintf(dst + len, maxlen - len, "%s", buf);
+	}
+	SNPRINTF_CHECK(ret, maxlen - len);
+	len += ret;
+
+	return len;
+}
+
+static int rrset_txt_dump(const knot_rrset_t      *rrset,
+                          char                    *dst,
+                          const size_t            maxlen,
+                          const knot_dump_style_t *style)
+{
+	if (rrset == NULL || dst == NULL || style == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	size_t len = 0;
+
+	dst[0] = '\0';
+
+	// Loop over rdata in rrset.
+	uint16_t rr_count = rrset->rrs.count;
+	knot_rdata_t *rr = rrset->rrs.rdata;
+	for (uint16_t i = 0; i < rr_count; i++) {
+		// Dump rdata owner, class, ttl and type.
+		uint32_t ttl = ((style->original_ttl && rrset->type == KNOT_RRTYPE_RRSIG) ?
+		                knot_rrsig_original_ttl(rr) : rrset->ttl);
+
+		int ret = knot_rrset_txt_dump_header(rrset, ttl, dst + len,
+		                                     maxlen - len, style);
+		if (ret < 0) {
+			return KNOT_ESPACE;
+		}
+		len += ret;
+
+		// Dump rdata as such.
+		ret = knot_rrset_txt_dump_data(rrset, i, dst + len,
+		                               maxlen - len, style);
+		if (ret < 0) {
+			return KNOT_ESPACE;
+		}
+		len += ret;
+
+		// Terminate line.
+		if (len >= maxlen - 1) {
+			return KNOT_ESPACE;
+		}
+		dst[len++] = '\n';
+		dst[len] = '\0';
+
+		rr = knot_rdataset_next(rr);
+	}
+
+	return len;
+}
+
+_public_
+int knot_rrset_txt_dump(const knot_rrset_t      *rrset,
+                        char                    **dst,
+                        size_t                  *dst_size,
+                        const knot_dump_style_t *style)
+{
+	if (dst == NULL || dst_size == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	while (1) {
+		int ret = rrset_txt_dump(rrset, *dst, *dst_size, style);
+		if (ret != KNOT_ESPACE) {
+			return ret;
+		}
+
+		size_t new_dst_size = 2 * (*dst_size);
+		if (new_dst_size > RRSET_DUMP_LIMIT) {
+			return KNOT_ESPACE;
+		}
+
+		char * new_dst = malloc(new_dst_size);
+		if (new_dst == NULL) {
+			return KNOT_ENOMEM;
+		}
+
+		free(*dst);
+		*dst = new_dst;
+		*dst_size = new_dst_size;
+	}
+}