Adding upstream version 3.2.6.upstream/3.2.6upstream

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

1 files changed, 727 insertions, 0 deletions

diff --git a/src/libknot/packet/rrset-wire.c b/src/libknot/packet/rrset-wire.c
new file mode 100644
index 0000000..2b02969
--- /dev/null
+++ b/src/libknot/packet/rrset-wire.c
@@ -0,0 +1,727 @@
+/*  Copyright (C) 2021 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 <assert.h>
+
+#include "libknot/attribute.h"
+#include "libknot/consts.h"
+#include "libknot/descriptor.h"
+#include "libknot/packet/pkt.h"
+#include "libknot/packet/rrset-wire.h"
+#include "libknot/rrtype/naptr.h"
+#include "libknot/rrtype/rrsig.h"
+#include "libknot/rrtype/soa.h"
+#include "contrib/macros.h"
+#include "contrib/mempattern.h"
+#include "contrib/tolower.h"
+#include "contrib/wire_ctx.h"
+
+/*!
+ * \brief Get maximal size of a domain name in a wire with given capacity.
+ */
+static uint16_t dname_max(size_t wire_avail)
+{
+	return MIN(wire_avail, KNOT_DNAME_MAXLEN);
+}
+
+/*!
+ * \brief Compares two domain name labels.
+ *
+ * \param label1  First label.
+ * \param label2  Second label (may be in upper-case).
+ *
+ * \retval true if the labels are identical
+ * \retval false if the labels are NOT identical
+ */
+static bool label_is_equal(const uint8_t *label1, const uint8_t *label2)
+{
+	assert(label1 && label2);
+
+	if (*label1 != *label2) {
+		return false;
+	}
+
+	uint8_t len = *label1;
+	for (uint8_t i = 1; i <= len; i++) {
+		if (label1[i] != knot_tolower(label2[i])) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+/*!
+ * Case insensitive comparison of two dnames in wire format.
+ * The second name may be compressed in a supplied wire.
+ */
+static bool dname_equal_wire(const knot_dname_t *d1, const knot_dname_t *d2,
+                             const uint8_t *wire)
+{
+	assert(d1);
+	assert(d2);
+
+	d2 = knot_wire_seek_label(d2, wire);
+
+	while (*d1 != '\0' || *d2 != '\0') {
+		if (!label_is_equal(d1, d2)) {
+			return false;
+		}
+		d1 = knot_wire_next_label(d1, NULL);
+		d2 = knot_wire_next_label(d2, wire);
+	}
+
+	return true;
+}
+
+static uint16_t compr_get_ptr(knot_compr_t *compr, uint16_t hint)
+{
+	if (compr == NULL) {
+		return 0;
+	}
+
+	return knot_compr_hint(compr->rrinfo, hint);
+}
+
+static void compr_set_ptr(knot_compr_t *compr, uint16_t hint,
+                          const uint8_t *written_at, uint16_t written_size)
+{
+	if (compr == NULL) {
+		return;
+	}
+
+	assert(written_at >= compr->wire);
+
+	uint16_t offset = written_at - compr->wire;
+
+	if (knot_wire_is_pointer(written_at)) {
+		offset = knot_wire_get_pointer(written_at);
+	}
+
+	knot_compr_hint_set(compr->rrinfo, hint, offset, written_size);
+}
+
+static int write_rdata_fixed(const uint8_t **src, size_t *src_avail,
+                             uint8_t **dst, size_t *dst_avail, size_t size)
+{
+	assert(src && *src);
+	assert(src_avail);
+	assert(dst && *dst);
+	assert(dst_avail);
+
+	// Check input/output buffer boundaries.
+	if (size > *src_avail) {
+		return KNOT_EMALF;
+	}
+
+	if (size > *dst_avail) {
+		return KNOT_ESPACE;
+	}
+
+	// Data binary copy.
+	memcpy(*dst, *src, size);
+
+	// Update buffers.
+	*src += size;
+	*src_avail -= size;
+
+	*dst += size;
+	*dst_avail -= size;
+
+	return KNOT_EOK;
+}
+
+static int write_rdata_naptr_header(const uint8_t **src, size_t *src_avail,
+                                    uint8_t **dst, size_t *dst_avail)
+{
+	assert(src && *src);
+	assert(src_avail);
+	assert(dst && *dst);
+	assert(dst_avail);
+
+	int ret = knot_naptr_header_size(*src, *src + *src_avail);
+	if (ret < 0) {
+		return ret;
+	}
+
+	// Copy the data.
+	return write_rdata_fixed(src, src_avail, dst, dst_avail, ret);
+}
+
+/*! \brief Helper for \ref compr_put_dname, writes label(s) with size checks. */
+#define WRITE_LABEL(dst, written, label, max, len) \
+	if ((written) + (len) > (max)) { \
+		return KNOT_ESPACE; \
+	} else { \
+		memcpy((dst) + (written), (label), (len)); \
+		written += (len); \
+	}
+
+/*!
+ * \brief Write compressed domain name to the destination wire.
+ *
+ * \param dname  Name to be written.
+ * \param dst    Destination wire.
+ * \param max    Maximum number of bytes available.
+ * \param compr  Compression context (NULL for no compression)
+ * \return Number of written bytes or an error.
+ */
+static int compr_put_dname(const knot_dname_t *dname, uint8_t *dst, uint16_t max,
+                           knot_compr_t *compr)
+{
+	assert(dname && dst);
+
+	// Write uncompressible names directly (zero label dname).
+	if (compr == NULL || *dname == '\0') {
+		return knot_dname_to_wire(dst, dname, max);
+	}
+
+	// Get number of labels (should not be a zero label dname).
+	size_t name_labels = knot_dname_labels(dname, NULL);
+	assert(name_labels > 0);
+
+	// Suffix must not be longer than whole name.
+	const knot_dname_t *suffix = compr->wire + compr->suffix.pos;
+	int suffix_labels = compr->suffix.labels;
+	while (suffix_labels > name_labels) {
+		suffix = knot_wire_next_label(suffix, compr->wire);
+		--suffix_labels;
+	}
+
+	// Suffix is shorter than name, write labels until aligned.
+	uint8_t orig_labels = name_labels;
+	uint16_t written = 0;
+	while (name_labels > suffix_labels) {
+		WRITE_LABEL(dst, written, dname, max, (*dname + 1));
+		dname = knot_wire_next_label(dname, NULL);
+		--name_labels;
+	}
+
+	// Label count is now equal.
+	assert(name_labels == suffix_labels);
+	const knot_dname_t *match_begin = dname;
+	const knot_dname_t *compr_ptr = suffix;
+	while (dname[0] != '\0') {
+		// Next labels.
+		const knot_dname_t *next_dname = knot_wire_next_label(dname, NULL);
+		const knot_dname_t *next_suffix = knot_wire_next_label(suffix, compr->wire);
+
+		// Two labels match, extend suffix length.
+		if (!label_is_equal(dname, suffix)) {
+			// If they don't match, write unmatched labels.
+			uint16_t mismatch_len = (dname - match_begin) + (*dname + 1);
+			WRITE_LABEL(dst, written, match_begin, max, mismatch_len);
+			// Start new potential match.
+			match_begin = next_dname;
+			compr_ptr = next_suffix;
+		}
+
+		// Jump to next labels.
+		dname = next_dname;
+		suffix = next_suffix;
+	}
+
+	// If match begins at the end of the name, write '\0' label.
+	if (match_begin == dname) {
+		WRITE_LABEL(dst, written, dname, max, 1);
+	} else {
+		// Match covers >0 labels, write out compression pointer.
+		if (written + sizeof(uint16_t) > max) {
+			return KNOT_ESPACE;
+		}
+		knot_wire_put_pointer(dst + written, compr_ptr - compr->wire);
+		written += sizeof(uint16_t);
+	}
+
+	assert(dst >= compr->wire);
+	size_t wire_pos = dst - compr->wire;
+	assert(wire_pos < KNOT_WIRE_MAX_PKTSIZE);
+
+	// Heuristics - expect similar names are grouped together.
+	if (written > sizeof(uint16_t) && wire_pos + written < KNOT_WIRE_PTR_MAX) {
+		compr->suffix.pos = wire_pos;
+		compr->suffix.labels = orig_labels;
+	}
+
+	return written;
+}
+
+#define WRITE_OWNER_CHECK(size, dst_avail) \
+	if ((size) > *(dst_avail)) { \
+		return KNOT_ESPACE; \
+	}
+
+#define WRITE_OWNER_INCR(dst, dst_avail, size) \
+	*(dst) += (size); \
+	*(dst_avail) -= (size);
+
+static int write_owner(const knot_rrset_t *rrset, uint8_t **dst, size_t *dst_avail,
+                       knot_compr_t *compr)
+{
+	assert(rrset);
+	assert(dst && *dst);
+	assert(dst_avail);
+
+	// Check for zero label owner (don't compress).
+	uint16_t owner_pointer = 0;
+	if (*rrset->owner != '\0') {
+		owner_pointer = compr_get_ptr(compr, KNOT_COMPR_HINT_OWNER);
+	}
+
+	// Write result.
+	if (owner_pointer > 0) {
+		WRITE_OWNER_CHECK(sizeof(uint16_t), dst_avail);
+		knot_wire_put_pointer(*dst, owner_pointer);
+		WRITE_OWNER_INCR(dst, dst_avail, sizeof(uint16_t));
+	// Check for coincidence with previous RR set.
+	} else if (compr != NULL && compr->suffix.pos != 0 && *rrset->owner != '\0' &&
+	           dname_equal_wire(rrset->owner, compr->wire + compr->suffix.pos,
+	                            compr->wire)) {
+		WRITE_OWNER_CHECK(sizeof(uint16_t), dst_avail);
+		knot_wire_put_pointer(*dst, compr->suffix.pos);
+		compr_set_ptr(compr, KNOT_COMPR_HINT_OWNER,
+		              compr->wire + compr->suffix.pos,
+		              knot_dname_size(rrset->owner));
+		WRITE_OWNER_INCR(dst, dst_avail, sizeof(uint16_t));
+	} else {
+		if (compr != NULL) {
+			compr->suffix.pos = KNOT_WIRE_HEADER_SIZE;
+			compr->suffix.labels =
+				knot_dname_labels(compr->wire + compr->suffix.pos,
+				                  compr->wire);
+		}
+		// WRITE_OWNER_CHECK not needed, compr_put_dname has a check.
+		int written = compr_put_dname(rrset->owner, *dst,
+		                              dname_max(*dst_avail), compr);
+		if (written < 0) {
+			return written;
+		}
+
+		compr_set_ptr(compr, KNOT_COMPR_HINT_OWNER, *dst, written);
+		WRITE_OWNER_INCR(dst, dst_avail, written);
+	}
+
+	return KNOT_EOK;
+}
+
+static int write_fixed_header(const knot_rrset_t *rrset, uint16_t rrset_index,
+                              uint8_t **dst, size_t *dst_avail, uint16_t flags)
+{
+	assert(rrset);
+	assert(rrset_index < rrset->rrs.count);
+	assert(dst && *dst);
+	assert(dst_avail);
+
+	// Write header.
+	wire_ctx_t write = wire_ctx_init(*dst, *dst_avail);
+
+	wire_ctx_write_u16(&write, rrset->type);
+	wire_ctx_write_u16(&write, rrset->rclass);
+
+	if ((flags & KNOT_PF_ORIGTTL) && rrset->type == KNOT_RRTYPE_RRSIG) {
+		const knot_rdata_t *rdata = knot_rdataset_at(&rrset->rrs, rrset_index);
+		wire_ctx_write_u32(&write, knot_rrsig_original_ttl(rdata));
+	} else if ((flags & KNOT_PF_SOAMINTTL) && rrset->type == KNOT_RRTYPE_SOA) {
+		const knot_rdata_t *rdata = knot_rdataset_at(&rrset->rrs, rrset_index);
+		wire_ctx_write_u32(&write, MIN(knot_soa_minimum(rdata), rrset->ttl));
+	} else {
+		wire_ctx_write_u32(&write, rrset->ttl);
+	}
+
+	// Check write.
+	if (write.error != KNOT_EOK) {
+		return write.error;
+	}
+
+	// Update buffer.
+	*dst = write.position;
+	*dst_avail = wire_ctx_available(&write);
+
+	return KNOT_EOK;
+}
+
+static int compress_rdata_dname(const uint8_t **src, size_t *src_avail,
+                                uint8_t **dst, size_t *dst_avail,
+                                knot_compr_t *put_compr, knot_compr_t *compr,
+                                uint16_t hint)
+{
+	assert(src && *src);
+	assert(src_avail);
+	assert(dst && *dst);
+	assert(dst_avail);
+
+	// Source domain name.
+	const knot_dname_t *dname = *src;
+	size_t dname_size = knot_dname_size(dname);
+
+	// Output domain name.
+	int written = compr_put_dname(dname, *dst, dname_max(*dst_avail), put_compr);
+	if (written < 0) {
+		return written;
+	}
+
+	// Update compression hints.
+	if (compr_get_ptr(compr, hint) == 0) {
+		compr_set_ptr(compr, hint, *dst, written);
+	}
+
+	// Update buffers.
+	*dst += written;
+	*dst_avail -= written;
+
+	*src += dname_size;
+	*src_avail -= dname_size;
+
+	return KNOT_EOK;
+}
+
+static int rdata_traverse_write(const uint8_t **src, size_t *src_avail,
+                                uint8_t **dst, size_t *dst_avail,
+                                const knot_rdata_descriptor_t *desc,
+                                knot_compr_t *compr, uint16_t hint)
+{
+	for (const int *type = desc->block_types; *type != KNOT_RDATA_WF_END; type++) {
+		int ret;
+		knot_compr_t *put_compr = NULL;
+		switch (*type) {
+		case KNOT_RDATA_WF_COMPRESSIBLE_DNAME:
+			put_compr = compr;
+			// FALLTHROUGH
+		case KNOT_RDATA_WF_DECOMPRESSIBLE_DNAME:
+		case KNOT_RDATA_WF_FIXED_DNAME:
+			ret = compress_rdata_dname(src, src_avail, dst, dst_avail,
+			                           put_compr, compr, hint);
+			break;
+		case KNOT_RDATA_WF_NAPTR_HEADER:
+			ret = write_rdata_naptr_header(src, src_avail, dst, dst_avail);
+			break;
+		case KNOT_RDATA_WF_REMAINDER:
+			ret = write_rdata_fixed(src, src_avail, dst, dst_avail, *src_avail);
+			break;
+		default:
+			// Fixed size block.
+			assert(*type > 0);
+			ret = write_rdata_fixed(src, src_avail, dst, dst_avail, *type);
+			break;
+		}
+		if (ret != KNOT_EOK) {
+			return ret;
+		}
+	}
+
+	return KNOT_EOK;
+}
+
+static int write_rdata(const knot_rrset_t *rrset, uint16_t rrset_index,
+                       uint8_t **dst, size_t *dst_avail, knot_compr_t *compr)
+{
+	assert(rrset);
+	assert(rrset_index < rrset->rrs.count);
+	assert(dst && *dst);
+	assert(dst_avail);
+
+	const knot_rdata_t *rdata = knot_rdataset_at(&rrset->rrs, rrset_index);
+
+	// Reserve space for RDLENGTH.
+	if (sizeof(uint16_t) > *dst_avail) {
+		return KNOT_ESPACE;
+	}
+
+	uint8_t *wire_rdlength = *dst;
+	*dst += sizeof(uint16_t);
+	*dst_avail -= sizeof(uint16_t);
+	uint8_t *wire_rdata_begin = *dst;
+
+	// Write RDATA.
+	const uint8_t *src = rdata->data;
+	size_t src_avail = rdata->len;
+	if (src_avail > 0) {
+		// Only write non-empty data.
+		const knot_rdata_descriptor_t *desc =
+			knot_get_rdata_descriptor(rrset->type);
+		int ret = rdata_traverse_write(&src, &src_avail, dst, dst_avail,
+		                         desc, compr, KNOT_COMPR_HINT_RDATA + rrset_index);
+		if (ret != KNOT_EOK) {
+			return ret;
+		}
+	}
+
+	// Check for trailing data in the message.
+	if (src_avail > 0) {
+		return KNOT_EMALF;
+	}
+
+	// Write final RDLENGTH.
+	size_t rdlength = *dst - wire_rdata_begin;
+	knot_wire_write_u16(wire_rdlength, rdlength);
+
+	return KNOT_EOK;
+}
+
+static int write_rr(const knot_rrset_t *rrset, uint16_t rrset_index, uint8_t **dst,
+                    size_t *dst_avail, knot_compr_t *compr, uint16_t flags)
+{
+	int ret = write_owner(rrset, dst, dst_avail, compr);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	ret = write_fixed_header(rrset, rrset_index, dst, dst_avail, flags);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	return write_rdata(rrset, rrset_index, dst, dst_avail, compr);
+}
+
+_public_
+int knot_rrset_to_wire_extra(const knot_rrset_t *rrset, uint8_t *wire,
+                             uint16_t max_size, uint16_t rotate,
+                             knot_compr_t *compr, uint16_t flags)
+{
+	if (rrset == NULL || wire == NULL) {
+		return KNOT_EINVAL;
+	}
+	if (rrset->rrs.count == 0) {
+		return 0;
+	}
+	if (rotate != 0) {
+		rotate %= rrset->rrs.count;
+	}
+
+	uint8_t *write = wire;
+	size_t capacity = max_size;
+
+	uint16_t count = rrset->rrs.count;
+	for (int i = rotate; i < count + rotate; i++) {
+		uint16_t pos = (i < count) ? i : (i - count);
+		int ret = write_rr(rrset, pos, &write, &capacity, compr, flags);
+		if (ret != KNOT_EOK) {
+			return ret;
+		}
+	}
+
+	return write - wire;
+}
+
+static int parse_header(const uint8_t *wire, size_t *pos, size_t pkt_size,
+                        knot_mm_t *mm, knot_rrset_t *rrset, uint16_t *rdlen)
+{
+	assert(wire);
+	assert(pos);
+	assert(rrset);
+	assert(rdlen);
+
+	wire_ctx_t src = wire_ctx_init_const(wire, pkt_size);
+	wire_ctx_set_offset(&src, *pos);
+
+	int compr_size = knot_dname_wire_check(src.position, wire + pkt_size, wire);
+	if (compr_size <= 0) {
+		return KNOT_EMALF;
+	}
+
+	knot_dname_storage_t buff;
+	int decompr_size = knot_dname_unpack(buff, src.position, sizeof(buff), wire);
+	if (decompr_size <= 0) {
+		return KNOT_EMALF;
+	}
+
+	knot_dname_t *owner = mm_alloc(mm, decompr_size);
+	if (owner == NULL) {
+		return KNOT_ENOMEM;
+	}
+	memcpy(owner, buff, decompr_size);
+	wire_ctx_skip(&src, compr_size);
+
+	uint16_t type = wire_ctx_read_u16(&src);
+	uint16_t rclass = wire_ctx_read_u16(&src);
+	uint32_t ttl = wire_ctx_read_u32(&src);
+	*rdlen = wire_ctx_read_u16(&src);
+
+	if (src.error != KNOT_EOK) {
+		knot_dname_free(owner, mm);
+		return KNOT_EMALF;
+	}
+
+	if (wire_ctx_available(&src) < *rdlen) {
+		knot_dname_free(owner, mm);
+		return KNOT_EMALF;
+	}
+
+	*pos = wire_ctx_offset(&src);
+
+	knot_rrset_init(rrset, owner, type, rclass, ttl);
+
+	return KNOT_EOK;
+}
+
+static int decompress_rdata_dname(const uint8_t **src, size_t *src_avail,
+                                  uint8_t **dst, size_t *dst_avail,
+                                  const uint8_t *pkt_wire)
+{
+	assert(src && *src);
+	assert(src_avail);
+	assert(dst && *dst);
+	assert(dst_avail);
+
+	int compr_size = knot_dname_wire_check(*src, *src + *src_avail, pkt_wire);
+	if (compr_size <= 0) {
+		return compr_size;
+	}
+
+	int decompr_size = knot_dname_unpack(*dst, *src, *dst_avail, pkt_wire);
+	if (decompr_size <= 0) {
+		return decompr_size;
+	}
+
+	// Update buffers.
+	*dst += decompr_size;
+	*dst_avail -= decompr_size;
+
+	*src += compr_size;
+	*src_avail -= compr_size;
+
+	return KNOT_EOK;
+}
+
+static int rdata_traverse_parse(const uint8_t **src, size_t *src_avail,
+                                uint8_t **dst, size_t *dst_avail,
+                                const knot_rdata_descriptor_t *desc,
+                                const uint8_t *pkt_wire)
+{
+	for (const int *type = desc->block_types; *type != KNOT_RDATA_WF_END; type++) {
+		int ret;
+		switch (*type) {
+		case KNOT_RDATA_WF_COMPRESSIBLE_DNAME:
+		case KNOT_RDATA_WF_DECOMPRESSIBLE_DNAME:
+		case KNOT_RDATA_WF_FIXED_DNAME:
+			ret = decompress_rdata_dname(src, src_avail, dst, dst_avail,
+			                             pkt_wire);
+			break;
+		case KNOT_RDATA_WF_NAPTR_HEADER:
+			ret = write_rdata_naptr_header(src, src_avail, dst, dst_avail);
+			break;
+		case KNOT_RDATA_WF_REMAINDER:
+			ret = write_rdata_fixed(src, src_avail, dst, dst_avail, *src_avail);
+			break;
+		default:
+			/* Fixed size block */
+			assert(*type > 0);
+			ret = write_rdata_fixed(src, src_avail, dst, dst_avail, *type);
+			break;
+		}
+		if (ret != KNOT_EOK) {
+			return ret;
+		}
+	}
+
+	return KNOT_EOK;
+}
+
+static bool allow_zero_rdata(const knot_rrset_t *rr,
+                             const knot_rdata_descriptor_t *desc)
+{
+	return rr->rclass != KNOT_CLASS_IN ||  // NONE and ANY for DDNS
+	       rr->type == KNOT_RRTYPE_APL ||  // APL RR type
+	       desc->type_name == NULL;        // Unknown RR type
+}
+
+static int parse_rdata(const uint8_t *pkt_wire, size_t *pos, size_t pkt_size,
+                       knot_mm_t *mm, uint16_t rdlength, knot_rrset_t *rrset)
+{
+	assert(pkt_wire);
+	assert(pos);
+	assert(rrset);
+
+	const knot_rdata_descriptor_t *desc = knot_get_rdata_descriptor(rrset->type);
+	if (desc->type_name == NULL) {
+		desc = knot_get_obsolete_rdata_descriptor(rrset->type);
+	}
+
+	if (rdlength == 0) {
+		if (allow_zero_rdata(rrset, desc)) {
+			return knot_rrset_add_rdata(rrset, NULL, 0, mm);
+		} else {
+			return KNOT_EMALF;
+		}
+	} else if (pkt_size - *pos < rdlength) {
+		return KNOT_EMALF;
+	}
+
+	// Buffer for parsed rdata (decompression extends rdata length).
+	const size_t max_rdata_len = UINT16_MAX;
+	uint8_t buf[knot_rdata_size(max_rdata_len)];
+	knot_rdata_t *rdata = (knot_rdata_t *)buf;
+
+	const uint8_t *src = pkt_wire + *pos;
+	size_t src_avail = rdlength;
+	uint8_t *dst = rdata->data;
+	size_t dst_avail = max_rdata_len;
+
+	// Parse RDATA.
+	int ret = rdata_traverse_parse(&src, &src_avail, &dst, &dst_avail, desc, pkt_wire);
+	if (ret != KNOT_EOK) {
+		return KNOT_EMALF;
+	}
+
+	// Check for trailing data.
+	size_t real_len = max_rdata_len - dst_avail;
+	if (real_len < rdlength) {
+		return KNOT_EMALF;
+	}
+	rdata->len = real_len;
+
+	ret = knot_rdataset_add(&rrset->rrs, rdata, mm);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	// Update position pointer.
+	*pos += rdlength;
+
+	return KNOT_EOK;
+}
+
+_public_
+int knot_rrset_rr_from_wire(const uint8_t *wire, size_t *pos, size_t max_size,
+                            knot_rrset_t *rrset, knot_mm_t *mm, bool canonical)
+{
+	if (wire == NULL || pos == NULL || *pos > max_size || rrset == NULL) {
+		return KNOT_EINVAL;
+	}
+
+	uint16_t rdlen = 0;
+	int ret = parse_header(wire, pos, max_size, mm, rrset, &rdlen);
+	if (ret != KNOT_EOK) {
+		return ret;
+	}
+
+	ret = parse_rdata(wire, pos, max_size, mm, rdlen, rrset);
+	if (ret != KNOT_EOK) {
+		knot_rrset_clear(rrset, mm);
+		return ret;
+	}
+
+	// Convert RR to the canonical format.
+	if (canonical) {
+		ret = knot_rrset_rr_to_canonical(rrset);
+		if (ret != KNOT_EOK) {
+			knot_rrset_clear(rrset, mm);
+		}
+	}
+
+	return KNOT_EOK;
+}