dns.h File Reference

Implementation of the DNS protocol. More...

#include <freeradius-devel/util/packet.h>
#include <freeradius-devel/util/dns.h>

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Data Structures
struct	fr_dns_ctx_t
struct	fr_dns_packet_t

Macros
#define	DNS_HDR_LEN   (12)
#define	DNS_MAX_ATTRIBUTES   255
#define	FR_DNS_PACKET_CODE_VALID(_code)   (((_code) < FR_DNS_CODE_MAX) || (((_code & 0x10) != 0) && ((_code & ~0x10) < FR_DNS_CODE_MAX)))

Enumerations
enum	{   FLAG_ENCODE_NONE = 0 ,   FLAG_ENCODE_DNS_LABEL ,   FLAG_ENCODE_DNS_LABEL_UNCOMPRESSED }
	subtype values for DHCPv4 and DHCPv6 More...
enum	fr_dns_decode_fail_t {   FR_DNS_DECODE_FAIL_NONE = 0 ,   FR_DNS_DECODE_FAIL_MIN_LENGTH_PACKET ,   FR_DNS_DECODE_FAIL_MAX_LENGTH_PACKET ,   FR_DNS_DECODE_FAIL_UNEXPECTED ,   FR_DNS_DECODE_FAIL_NO_QUESTIONS ,   FR_DNS_DECODE_FAIL_ANSWERS_IN_QUESTION ,   FR_DNS_DECODE_FAIL_NS_IN_QUESTION ,   FR_DNS_DECODE_FAIL_INVALID_RR_LABEL ,   FR_DNS_DECODE_FAIL_MISSING_RR_HEADER ,   FR_DNS_DECODE_FAIL_MISSING_RR_LEN ,   FR_DNS_DECODE_FAIL_ZERO_RR_LEN ,   FR_DNS_DECODE_FAIL_RR_OVERFLOWS_PACKET ,   FR_DNS_DECODE_FAIL_TOO_MANY_RRS ,   FR_DNS_DECODE_FAIL_TOO_FEW_RRS ,   FR_DNS_DECODE_FAIL_POINTER_TO_NON_LABEL ,   FR_DNS_DECODE_FAIL_POINTER_OVERFLOWS_PACKET ,   FR_DNS_DECODE_FAIL_POINTER_TO_HEADER ,   FR_DNS_DECODE_FAIL_POINTER_LOOPS ,   FR_DNS_DECODE_FAIL_INVALID_POINTER ,   FR_DNS_DECODE_FAIL_LABEL_OVERFLOWS_PACKET ,   FR_DNS_DECODE_FAIL_LABEL_TOO_LONG ,   FR_DNS_DECODE_FAIL_MISSING_QD_HEADER ,   FR_DNS_DECODE_FAIL_MISSING_TLV_HEADER ,   FR_DNS_DECODE_FAIL_TLV_OVERFLOWS_RR ,   FR_DNS_DECODE_FAIL_MAX }
enum	fr_dns_packet_code_t {   FR_DNS_QUERY = 0 ,   FR_DNS_INVERSE_QUERY = 1 ,   FR_DNS_STATUS = 2 ,   FR_DNS_NOTIFY = 4 ,   FR_DNS_UPDATE = 5 ,   FR_DNS_STATEFUL_OPERATION = 6 ,   FR_DNS_CODE_MAX = 7 ,   FR_DNS_QUERY_RESPONSE = 16 ,   FR_DNS_INVERSE_QUERY_RESPONSE = 17 ,   FR_DNS_STATUS_RESPONSE = 18 ,   FR_DNS_NOTIFY_RESPONSE = 20 ,   FR_DNS_UPDATE_RESPONSE = 21 ,   FR_DNS_STATEFUL_OPERATION_RESPONSE = 22 ,   FR_DNS_DO_NOT_RESPOND = 256 }

Functions
ssize_t	fr_dns_decode (TALLOC_CTX *ctx, fr_pair_list_t *out, uint8_t const *packet, size_t packet_len, fr_dns_ctx_t *packet_ctx)
	Decode a DNS packet. More...
ssize_t	fr_dns_encode (fr_dbuff_t *dbuff, fr_pair_list_t *vps, fr_dns_ctx_t *encode_ctx)
	Encode a DNS packet. More...
void	fr_dns_global_free (void)
int	fr_dns_global_init (void)
	Resolve/cache attributes in the DNS dictionary. More...
fr_dns_labels_t *	fr_dns_labels_get (uint8_t const *packet, size_t packet_len, bool init_mark)
bool	fr_dns_packet_ok (uint8_t const *packet, size_t packet_len, bool query, fr_dns_decode_fail_t *reason)

Variables
char const *	fr_dns_packet_names [FR_DNS_CODE_MAX]
fr_table_num_ordered_t	fr_dns_reason_fail_table []
size_t	fr_dns_reason_fail_table_len

Detailed Description

Implementation of the DNS protocol.

Id

3033910e1bdf3474aa396cc3609794aeb8181aec

Copyright

2021 Network RADIUS SAS (legal.nosp@m.@net.nosp@m.workr.nosp@m.adiu.nosp@m.s.com)

Definition in file dns.h.

---

Data Structure Documentation

fr_dns_ctx_t

struct fr_dns_ctx_t

Definition at line 82 of file dns.h.

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Data Fields
fr_dns_labels_t *	lb
uint8_t const *	packet	DNS labels can point anywhere in the packet :(.
size_t	packet_len
TALLOC_CTX *	tmp_ctx	for temporary things cleaned up during decoding

fr_dns_packet_t

struct fr_dns_packet_t

Definition at line 37 of file dns.h.

Data Fields
uint16_t	ancount
uint16_t	arcount
unsigned int	authentic_data: 1
unsigned int	authoritative: 1
unsigned int	checking_disabled: 1
uint16_t	id
uint16_t	nscount
unsigned int	opcode: 4
uint16_t	qdcount
unsigned int	query: 1
unsigned int	rcode: 4
unsigned int	recursion_available: 1
unsigned int	recursion_desired: 1
unsigned int	reserved: 1
unsigned int	truncated: 1

Macro Definition Documentation

DNS_HDR_LEN

#define DNS_HDR_LEN   (12)

Definition at line 141 of file dns.h.

DNS_MAX_ATTRIBUTES

#define DNS_MAX_ATTRIBUTES   255

Definition at line 35 of file dns.h.

FR_DNS_PACKET_CODE_VALID

#define FR_DNS_PACKET_CODE_VALID

(

_code

)

(((_code) < FR_DNS_CODE_MAX) || (((_code & 0x10) != 0) && ((_code & ~0x10) < FR_DNS_CODE_MAX)))

Definition at line 139 of file dns.h.

Enumeration Type Documentation

anonymous enum

anonymous enum

subtype values for DHCPv4 and DHCPv6

Enumerator
FLAG_ENCODE_NONE	no particular encoding for DNS strings
FLAG_ENCODE_DNS_LABEL	encode as DNS label
FLAG_ENCODE_DNS_LABEL_UNCOMPRESSED	encode as uncompressed DNS label

Definition at line 76 of file dns.h.

fr_dns_decode_fail_t

enum fr_dns_decode_fail_t

Enumerator
FR_DNS_DECODE_FAIL_NONE
FR_DNS_DECODE_FAIL_MIN_LENGTH_PACKET
FR_DNS_DECODE_FAIL_MAX_LENGTH_PACKET
FR_DNS_DECODE_FAIL_UNEXPECTED
FR_DNS_DECODE_FAIL_NO_QUESTIONS
FR_DNS_DECODE_FAIL_ANSWERS_IN_QUESTION
FR_DNS_DECODE_FAIL_NS_IN_QUESTION
FR_DNS_DECODE_FAIL_INVALID_RR_LABEL
FR_DNS_DECODE_FAIL_MISSING_RR_HEADER
FR_DNS_DECODE_FAIL_MISSING_RR_LEN
FR_DNS_DECODE_FAIL_ZERO_RR_LEN
FR_DNS_DECODE_FAIL_RR_OVERFLOWS_PACKET
FR_DNS_DECODE_FAIL_TOO_MANY_RRS
FR_DNS_DECODE_FAIL_TOO_FEW_RRS
FR_DNS_DECODE_FAIL_POINTER_TO_NON_LABEL
FR_DNS_DECODE_FAIL_POINTER_OVERFLOWS_PACKET
FR_DNS_DECODE_FAIL_POINTER_TO_HEADER
FR_DNS_DECODE_FAIL_POINTER_LOOPS
FR_DNS_DECODE_FAIL_INVALID_POINTER
FR_DNS_DECODE_FAIL_LABEL_OVERFLOWS_PACKET
FR_DNS_DECODE_FAIL_LABEL_TOO_LONG
FR_DNS_DECODE_FAIL_MISSING_QD_HEADER
FR_DNS_DECODE_FAIL_MISSING_TLV_HEADER
FR_DNS_DECODE_FAIL_TLV_OVERFLOWS_RR
FR_DNS_DECODE_FAIL_MAX

Definition at line 111 of file dns.h.

fr_dns_packet_code_t

enum fr_dns_packet_code_t

Enumerator
FR_DNS_QUERY
FR_DNS_INVERSE_QUERY
FR_DNS_STATUS
FR_DNS_NOTIFY
FR_DNS_UPDATE
FR_DNS_STATEFUL_OPERATION
FR_DNS_CODE_MAX
FR_DNS_QUERY_RESPONSE
FR_DNS_INVERSE_QUERY_RESPONSE
FR_DNS_STATUS_RESPONSE
FR_DNS_NOTIFY_RESPONSE
FR_DNS_UPDATE_RESPONSE
FR_DNS_STATEFUL_OPERATION_RESPONSE
FR_DNS_DO_NOT_RESPOND

Definition at line 92 of file dns.h.

Function Documentation

fr_dns_decode()

ssize_t fr_dns_decode	(	TALLOC_CTX *	ctx,
		fr_pair_list_t *	out,
		uint8_t const *	packet,
		size_t	packet_len,
		fr_dns_ctx_t *	packet_ctx
	)

Decode a DNS packet.

Definition at line 265 of file decode.c.

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fr_dns_encode()

ssize_t fr_dns_encode	(	fr_dbuff_t *	dbuff,
		fr_pair_list_t *	vps,
		fr_dns_ctx_t *	encode_ctx
	)

Encode a DNS packet.

Definition at line 454 of file encode.c.

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fr_dns_global_free()

void fr_dns_global_free

(

void

)

Definition at line 426 of file base.c.

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fr_dns_global_init()

int fr_dns_global_init

(

void

)

Resolve/cache attributes in the DNS dictionary.

Returns

• 0 on success.
• -1 on failure.

Definition at line 404 of file base.c.

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fr_dns_labels_get()

fr_dns_labels_t* fr_dns_labels_get	(	uint8_t const *	packet,
		size_t	packet_len,
		bool	init_mark
	)

Definition at line 375 of file base.c.

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fr_dns_packet_ok()

bool fr_dns_packet_ok	(	uint8_t const *	packet,
		size_t	packet_len,
		bool	query,
		fr_dns_decode_fail_t *	reason
	)

Definition at line 100 of file base.c.

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Variable Documentation

fr_dns_packet_names

char const* fr_dns_packet_names[FR_DNS_CODE_MAX]

extern

Definition at line 68 of file base.c.

fr_dns_reason_fail_table

fr_table_num_ordered_t fr_dns_reason_fail_table[]

extern

Definition at line 387 of file decode.c.

fr_dns_reason_fail_table_len

size_t fr_dns_reason_fail_table_len

extern

Definition at line 413 of file decode.c.