Common DNS routines. More...

#include "core/net.h"

Macros
#define	DNS_NAME_MAX_RECURSION 4

#define	DNS_MESSAGE_MAX_SIZE 512

#define	DNS_NAME_MAX_SIZE 255

#define	DNS_LABEL_MAX_SIZE 63

#define	DNS_MAX_IPV4_REVERSE_NAME_LEN 15

#define	DNS_MAX_IPV6_REVERSE_NAME_LEN 63

#define	DNS_PORT 53

#define	DNS_COMPRESSION_TAG 0xC0

#define	DNS_GET_QUESTION(message, offset) (DnsQuestion ) ((uint8_t ) (message) + (offset))

#define	DNS_GET_RESOURCE_RECORD(message, offset) (DnsResourceRecord ) ((uint8_t ) (message) + (offset))

#define	DNS_SET_NSEC_BITMAP(bitmap, type) bitmap[(type) / 8] \|= 0x80 >> ((type) % 8)

#define	DNS_CLR_NSEC_BITMAP(bitmap, type) bitmap[(type) / 8] &= ~(0x80 >> ((type) % 8))

Enumerations
enum	DnsOpcode { DNS_OPCODE_QUERY = 0, DNS_OPCODE_IQUERY = 1, DNS_OPCODE_STATUS = 2, DNS_OPCODE_NOTIFY = 4, DNS_OPCODE_UPDATE = 5 }
	DNS opcodes. More...

enum	DnsResponseCode { DNS_RCODE_NOERROR = 0, DNS_RCODE_FORMERR = 1, DNS_RCODE_SERVFAIL = 2, DNS_RCODE_NXDOMAIN = 3, DNS_RCODE_NOTIMP = 4, DNS_RCODE_REFUSED = 5, DNS_RCODE_YXDOMAIN = 6, DNS_RCODE_YXRRSET = 7, DNS_RCODE_NXRRSET = 8, DNS_RCODE_NOTAUTH = 9, DNS_RCODE_NOTZONE = 10, DNS_RCODE_BADVERS = 16, DNS_RCODE_BADSIG = 16, DNS_RCODE_BADKEY = 17, DNS_RCODE_BADTIME = 18, DNS_RCODE_BADMODE = 19, DNS_RCODE_BADNAME = 20, DNS_RCODE_BADALG = 21, DNS_RCODE_BADTRUC = 22, DNS_RCODE_BADCOOKIE = 23 }
	DNS response codes. More...

enum	DnsResourceRecordClass { DNS_RR_CLASS_IN = 1, DNS_RR_CLASS_CH = 3, DNS_RR_CLASS_HS = 4, DNS_RR_CLASS_ANY = 255 }
	DNS resource record classes. More...

enum	DnsResourceRecordType { DNS_RR_TYPE_A = 1, DNS_RR_TYPE_NS = 2, DNS_RR_TYPE_CNAME = 5, DNS_RR_TYPE_SOA = 6, DNS_RR_TYPE_WKS = 11, DNS_RR_TYPE_PTR = 12, DNS_RR_TYPE_HINFO = 13, DNS_RR_TYPE_MINFO = 14, DNS_RR_TYPE_MX = 15, DNS_RR_TYPE_TXT = 16, DNS_RR_TYPE_AAAA = 28, DNS_RR_TYPE_NB = 32, DNS_RR_TYPE_SRV = 33, DNS_RR_TYPE_NAPTR = 35, DNS_RR_TYPE_NSEC = 47, DNS_RR_TYPE_EUI48 = 108, DNS_RR_TYPE_EUI64 = 109, DNS_RR_TYPE_AXFR = 252, DNS_RR_TYPE_ANY = 255, DNS_RR_TYPE_URI = 256 }
	DNS resource record types. More...

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...

Variables
typedef	__packed_struct
	DNS message header. More...

uint8_t	rd

uint8_t	tc

uint8_t	aa

uint8_t	opcode

uint8_t	qr

uint8_t	rcode

uint8_t	z

uint8_t	ra

uint16_t	qdcount

uint16_t	ancount

uint16_t	nscount

uint16_t	arcount

uint8_t	questions []

	DnsHeader

uint16_t	qclass

	DnsQuestion

uint16_t	rclass

uint32_t	ttl

uint16_t	rdlength

uint8_t	rdata []

	DnsResourceRecord

	DnsIpv4AddrResourceRecord

	DnsIpv6AddrResourceRecord

uint16_t	priority

uint16_t	weight

uint16_t	port

uint8_t	target []

	DnsSrvResourceRecord

Detailed Description

Common DNS routines.

License

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

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: 2.4.4

Definition in file dns_common.h.

Macro Definition Documentation

◆ DNS_CLR_NSEC_BITMAP

#define DNS_CLR_NSEC_BITMAP	(	bitmap,
		type
	)	bitmap[(type) / 8] &= ~(0x80 >> ((type) % 8))

Definition at line 67 of file dns_common.h.

◆ DNS_COMPRESSION_TAG

#define DNS_COMPRESSION_TAG 0xC0

Definition at line 60 of file dns_common.h.

◆ DNS_GET_QUESTION

#define DNS_GET_QUESTION	(	message,
		offset
	)	(DnsQuestion ) ((uint8_t ) (message) + (offset))

Definition at line 63 of file dns_common.h.

◆ DNS_GET_RESOURCE_RECORD

#define DNS_GET_RESOURCE_RECORD	(	message,
		offset
	)	(DnsResourceRecord ) ((uint8_t ) (message) + (offset))

Definition at line 64 of file dns_common.h.

◆ DNS_LABEL_MAX_SIZE

#define DNS_LABEL_MAX_SIZE 63

Definition at line 49 of file dns_common.h.

◆ DNS_MAX_IPV4_REVERSE_NAME_LEN

#define DNS_MAX_IPV4_REVERSE_NAME_LEN 15

Definition at line 52 of file dns_common.h.

◆ DNS_MAX_IPV6_REVERSE_NAME_LEN

#define DNS_MAX_IPV6_REVERSE_NAME_LEN 63

Definition at line 54 of file dns_common.h.

◆ DNS_MESSAGE_MAX_SIZE

#define DNS_MESSAGE_MAX_SIZE 512

Definition at line 45 of file dns_common.h.

◆ DNS_NAME_MAX_RECURSION

#define DNS_NAME_MAX_RECURSION 4

Definition at line 39 of file dns_common.h.

◆ DNS_NAME_MAX_SIZE

#define DNS_NAME_MAX_SIZE 255

Definition at line 47 of file dns_common.h.

◆ DNS_PORT

#define DNS_PORT 53

Definition at line 57 of file dns_common.h.

◆ DNS_SET_NSEC_BITMAP

#define DNS_SET_NSEC_BITMAP	(	bitmap,
		type
	)	bitmap[(type) / 8] \|= 0x80 >> ((type) % 8)

Definition at line 66 of file dns_common.h.

Enumeration Type Documentation

◆ DnsOpcode

enum DnsOpcode

DNS opcodes.

Enumerator
DNS_OPCODE_QUERY	Query.
DNS_OPCODE_IQUERY	Inverse query.
DNS_OPCODE_STATUS	Status.
DNS_OPCODE_NOTIFY	Notify.
DNS_OPCODE_UPDATE	Update.

Definition at line 79 of file dns_common.h.

◆ DnsResourceRecordClass

enum DnsResourceRecordClass

DNS resource record classes.

Enumerator
DNS_RR_CLASS_IN	Internet.
DNS_RR_CLASS_CH	Chaos.
DNS_RR_CLASS_HS	Hesiod.
DNS_RR_CLASS_ANY	Any class.

Definition at line 122 of file dns_common.h.

◆ DnsResourceRecordType

enum DnsResourceRecordType

DNS resource record types.

Enumerator
DNS_RR_TYPE_A	Host address.
DNS_RR_TYPE_NS	Authoritative name server.
DNS_RR_TYPE_CNAME	Canonical name for an alias.
DNS_RR_TYPE_SOA	Start of a zone of authority.
DNS_RR_TYPE_WKS	Well known service description.
DNS_RR_TYPE_PTR	Domain name pointer.
DNS_RR_TYPE_HINFO	Host information.
DNS_RR_TYPE_MINFO	Mailbox or mail list information.
DNS_RR_TYPE_MX	Mail exchange.
DNS_RR_TYPE_TXT	Text strings.
DNS_RR_TYPE_AAAA	IPv6 address.
DNS_RR_TYPE_NB	NetBIOS name service.
DNS_RR_TYPE_SRV	Server selection.
DNS_RR_TYPE_NAPTR	Naming authority pointer.
DNS_RR_TYPE_NSEC	NSEC record.
DNS_RR_TYPE_EUI48	EUI-48 address.
DNS_RR_TYPE_EUI64	EUI-64 address.
DNS_RR_TYPE_AXFR	Transfer of an entire zone.
DNS_RR_TYPE_ANY	A request for all records.
DNS_RR_TYPE_URI	Uniform resource identifier.

Definition at line 135 of file dns_common.h.

◆ DnsResponseCode

enum DnsResponseCode

DNS response codes.

Enumerator
DNS_RCODE_NOERROR	No error.
DNS_RCODE_FORMERR	Format error.
DNS_RCODE_SERVFAIL	Server failure.
DNS_RCODE_NXDOMAIN	Non-existent domain.
DNS_RCODE_NOTIMP	Not implemented.
DNS_RCODE_REFUSED	Query refused.
DNS_RCODE_YXDOMAIN	Name exists when it should not.
DNS_RCODE_YXRRSET	RR set exists when it should not.
DNS_RCODE_NXRRSET	RR set that should exist does not.
DNS_RCODE_NOTAUTH	Server not authoritative for zone.
DNS_RCODE_NOTZONE	Name not contained in zone.
DNS_RCODE_BADVERS	Bad OPT version.
DNS_RCODE_BADSIG	TSIG signature failure.
DNS_RCODE_BADKEY	Key not recognized.
DNS_RCODE_BADTIME	Signature out of time window.
DNS_RCODE_BADMODE	Bad TKEY mode.
DNS_RCODE_BADNAME	Duplicate key name.
DNS_RCODE_BADALG	Algorithm not supported.
DNS_RCODE_BADTRUC	Bad truncation.
DNS_RCODE_BADCOOKIE	Bad server cookie.

Definition at line 93 of file dns_common.h.

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.

Variable Documentation

◆ __packed_struct

typedef __packed_struct

Initial value:

{

uint16_t id

DNS message header.

SRV resource record format.

AAAA resource record format.

A resource record format.

Resource record format.

Question format.

Definition at line 172 of file dns_common.h.

◆ aa

uint8_t aa

Definition at line 187 of file dns_common.h.

◆ ancount

uint16_t ancount

Definition at line 195 of file dns_common.h.

◆ arcount

uint16_t arcount

Definition at line 197 of file dns_common.h.

◆ DnsHeader

DnsHeader

Definition at line 199 of file dns_common.h.

◆ DnsIpv4AddrResourceRecord

DnsIpv4AddrResourceRecord

Definition at line 238 of file dns_common.h.

◆ DnsIpv6AddrResourceRecord

DnsIpv6AddrResourceRecord

Definition at line 252 of file dns_common.h.

◆ DnsQuestion

DnsQuestion

Definition at line 210 of file dns_common.h.

◆ DnsResourceRecord

DnsResourceRecord

Definition at line 224 of file dns_common.h.

◆ DnsSrvResourceRecord

DnsSrvResourceRecord

Definition at line 269 of file dns_common.h.

◆ nscount

uint16_t nscount

Definition at line 196 of file dns_common.h.

◆ opcode

uint8_t opcode

Definition at line 188 of file dns_common.h.

◆ port

uint16_t port

Definition at line 267 of file dns_common.h.

◆ priority

uint16_t priority

Definition at line 265 of file dns_common.h.

◆ qclass

uint16_t qclass

Definition at line 209 of file dns_common.h.

◆ qdcount

uint16_t qdcount

Definition at line 194 of file dns_common.h.

◆ qr

uint8_t qr

Definition at line 189 of file dns_common.h.

◆ questions

uint8_t questions[]

Definition at line 198 of file dns_common.h.

◆ ra

uint8_t ra

Definition at line 192 of file dns_common.h.

◆ rclass

uint16_t rclass

Definition at line 220 of file dns_common.h.

◆ rcode

uint8_t rcode

Definition at line 190 of file dns_common.h.

◆ rd

uint8_t rd

Definition at line 185 of file dns_common.h.

◆ rdata

uint8_t rdata

Definition at line 223 of file dns_common.h.

◆ rdlength

uint16_t rdlength

Definition at line 222 of file dns_common.h.

◆ target

uint8_t target[]

Definition at line 268 of file dns_common.h.

◆ tc

uint8_t tc

Definition at line 186 of file dns_common.h.

◆ ttl

uint32_t ttl

Definition at line 221 of file dns_common.h.

◆ weight

uint16_t weight

Definition at line 266 of file dns_common.h.

◆ z

uint8_t z

Definition at line 191 of file dns_common.h.

Macros

Enumerations

Functions

Variables

Detailed Description

License

Macro Definition Documentation

◆ DNS_CLR_NSEC_BITMAP

◆ DNS_COMPRESSION_TAG

◆ DNS_GET_QUESTION

◆ DNS_GET_RESOURCE_RECORD

◆ DNS_LABEL_MAX_SIZE

◆ DNS_MAX_IPV4_REVERSE_NAME_LEN

◆ DNS_MAX_IPV6_REVERSE_NAME_LEN

◆ DNS_MESSAGE_MAX_SIZE

◆ DNS_NAME_MAX_RECURSION

◆ DNS_NAME_MAX_SIZE

◆ DNS_PORT

◆ DNS_SET_NSEC_BITMAP

Enumeration Type Documentation

◆ DnsOpcode

◆ DnsResourceRecordClass

◆ DnsResourceRecordType

◆ DnsResponseCode

Function Documentation

◆ dnsCompareEncodedName()

◆ dnsCompareName()

◆ dnsEncodeName()

◆ dnsGenerateIpv4ReverseName()

◆ dnsGenerateIpv6ReverseName()

◆ dnsParseName()

Variable Documentation

◆ __packed_struct

◆ aa

◆ ancount

◆ arcount

◆ DnsHeader

◆ DnsIpv4AddrResourceRecord

◆ DnsIpv6AddrResourceRecord

◆ DnsQuestion

◆ DnsResourceRecord

◆ DnsSrvResourceRecord

◆ nscount

◆ opcode

◆ port

◆ priority

◆ qclass

◆ qdcount

◆ qr

◆ questions

◆ ra

◆ rclass

◆ rcode

◆ rd

◆ rdata

◆ rdlength

◆ target

◆ tc

◆ ttl

◆ weight

◆ z