dns_common.c File Reference

Common DNS routines. More...

#include "core/net.h"
#include "dns/dns_client.h"
#include "dns/dns_common.h"
#include "mdns/mdns_client.h"
#include "mdns/mdns_responder.h"
#include "mdns/mdns_common.h"
#include "llmnr/llmnr_client.h"
#include "llmnr/llmnr_responder.h"
#include "debug.h"

Go to the source code of this file.

Macros
#define	TRACE_LEVEL   DNS_TRACE_LEVEL

Functions
size_t	dnsEncodeName (const char_t *src, uint8_t *dest)
	Encode a domain name using the DNS name notation. More...
size_t	dnsParseName (const DnsHeader *message, size_t length, size_t pos, char_t *dest, uint_t level)
	Decode a domain name that uses the DNS name encoding. More...
int_t	dnsCompareName (const DnsHeader *message, size_t length, size_t pos, const char_t *name, uint_t level)
	Compare domain names. More...
int_t	dnsCompareEncodedName (const DnsHeader *message1, size_t length1, size_t pos1, const DnsHeader *message2, size_t length2, size_t pos2, uint_t level)
	Compare domain names encoded with DNS notation. More...
void	dnsGenerateIpv4ReverseName (Ipv4Addr ipv4Addr, char_t *buffer)
	Generate domain name for reverse DNS lookup (IPv4) More...
void	dnsGenerateIpv6ReverseName (const Ipv6Addr *ipv6Addr, char_t *buffer)
	Generate domain name for reverse DNS lookup (IPv6) More...

Detailed Description

Common DNS routines.

License

SPDX-License-Identifier: GPL-2.0-or-later

Copyright (C) 2010-2024 Oryx Embedded SARL. All rights reserved.

This file is part of CycloneTCP Open.

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 2 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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

Author

Oryx Embedded SARL (www.oryx-embedded.com)

Version

2.4.0

Definition in file dns_common.c.

Macro Definition Documentation

TRACE_LEVEL

#define TRACE_LEVEL   DNS_TRACE_LEVEL

Definition at line 32 of file dns_common.c.

Function Documentation

dnsCompareEncodedName()

int_t dnsCompareEncodedName	(	const DnsHeader *	message1,
		size_t	length1,
		size_t	pos1,
		const DnsHeader *	message2,
		size_t	length2,
		size_t	pos2,
		uint_t	level
	)

Compare domain names encoded with DNS notation.

Parameters

[in]	message1	Pointer to the first DNS message
[in]	length1	Length of the first DNS message
[in]	pos1	Offset of the encoded domain name within the first message
[in]	message2	Pointer to the second DNS message
[in]	length2	Length of the second DNS message
[in]	pos2	Offset of the encoded domain name within the second message
[in]	level	Current level of recursion

Returns

The function returns 0 if the domain names match, -1 if the first domain name lexicographically precedes the second name, or 1 if the second domain name lexicographically precedes the first name

Definition at line 341 of file dns_common.c.

dnsCompareName()

int_t dnsCompareName	(	const DnsHeader *	message,
		size_t	length,
		size_t	pos,
		const char_t *	name,
		uint_t	level
	)

Compare domain names.

Parameters

[in]	message	Pointer to the DNS message
[in]	length	Length of the DNS message
[in]	pos	Offset of the encoded domain name
[in]	name	NULL-terminated string that holds a domain name
[in]	level	Current level of recursion

Returns

The function returns 0 if the domain names match, -1 if the first domain name lexicographically precedes the second name, or 1 if the second domain name lexicographically precedes the first name

Definition at line 242 of file dns_common.c.

dnsEncodeName()

size_t dnsEncodeName	(	const char_t *	src,
		uint8_t *	dest
	)

Encode a domain name using the DNS name notation.

Parameters

[in]	src	Pointer to the domain name to encode
[out]	dest	Pointer to the encoded domain name (optional parameter)

Returns

Length of the encoded domain name

Definition at line 58 of file dns_common.c.

dnsGenerateIpv4ReverseName()

void dnsGenerateIpv4ReverseName	(	Ipv4Addr	ipv4Addr,
		char_t *	buffer
	)

Generate domain name for reverse DNS lookup (IPv4)

Parameters

[in]	ipv4Addr	IPv4 address
[out]	buffer	Output buffer where to store the resulting domain name

Definition at line 479 of file dns_common.c.

dnsGenerateIpv6ReverseName()

void dnsGenerateIpv6ReverseName	(	const Ipv6Addr *	ipv6Addr,
		char_t *	buffer
	)

Generate domain name for reverse DNS lookup (IPv6)

Parameters

[in]	ipv6Addr	IPv6 address
[out]	buffer	Output buffer where to store the resulting domain name

Definition at line 498 of file dns_common.c.

dnsParseName()

size_t dnsParseName	(	const DnsHeader *	message,
		size_t	length,
		size_t	pos,
		char_t *	dest,
		uint_t	level
	)

Decode a domain name that uses the DNS name encoding.

Parameters

[in]	message	Pointer to the DNS message
[in]	length	Length of the DNS message
[in]	pos	Offset of the name to decode
[out]	dest	Pointer to the decoded name (optional)
[in]	level	Current level of recursion

Returns

The position of the resource record that immediately follows the domain name

Definition at line 132 of file dns_common.c.