mdns_decoder.c File Reference

File containing the implementation of the mdns packet decoder utilities. More...

#include <netinet/udp.h>
#include "../../../utils/allocs.h"
#include "../../../utils/hash.h"
#include "../../../utils/iface.h"
#include "../../../utils/os.h"
#include "../../../utils/squeue.h"
#include "mdns_decoder.h"
#include "packet_decoder.h"

Include dependency graph for mdns_decoder.c:

Macros
#define	COMPRESSION_FLAG   0xC0
#define	COMPRESSION_FLAG_BIT7   0x80
#define	COMPRESSION_FLAG_BIT6   0x40

Functions
int	copy_mdns_query_name (uint8_t *start, char **out)
uint16_t	get_mdns_query_offset (uint8_t low, uint8_t high)
int	decode_mdns_query_name (uint8_t *payload, size_t len, size_t *first, char **out)
int	decode_mdns_queries (uint8_t *payload, size_t len, size_t *first, uint16_t nqueries, UT_array *queries)
	Decodes the mdns queries. More...
int	decode_mdns_answers (uint8_t *payload, size_t len, size_t *first, uint16_t nanswers, UT_array *answers)
	Decodes the mdns answers. More...
int	decode_mdns_header (uint8_t *packet, struct mdns_header *out)
	Decodes the mdns header. More...
bool	decode_mdns_packet (struct capture_packet *cpac)
	Decode mdns packet. More...

Detailed Description

File containing the implementation of the mdns packet decoder utilities.

Author

Alexandru Mereacre

Date

2021

Copyright

SPDX-FileCopyrightText: © 2021 NQMCyber Ltd and edgesec contributors SPDX-License-Identifier: LGPL-3.0-or-later

Macro Definition Documentation

COMPRESSION_FLAG

#define COMPRESSION_FLAG   0xC0

COMPRESSION_FLAG_BIT6

#define COMPRESSION_FLAG_BIT6   0x40

COMPRESSION_FLAG_BIT7

#define COMPRESSION_FLAG_BIT7   0x80

Function Documentation

copy_mdns_query_name()

int copy_mdns_query_name	(	uint8_t *	start,
		char **	out
	)

decode_mdns_answers()

int decode_mdns_answers	(	uint8_t *	payload,
		size_t	len,
		size_t *	first,
		uint16_t	nanswers,
		UT_array *	answers
	)

Decodes the mdns answers.

Parameters

	payload	The mdns payload
	len	The mdns payload length
[in,out]	first	The starting index to the answers field in the mdns payload. When done, this will be modified to be the starting index of the next field.
	nanswers	The number of answers
[in,out]	answers	The mdns_answer_entry answers array

Returns

0 Success, -1 on failure

decode_mdns_header()

int decode_mdns_header	(	uint8_t *	packet,
		struct mdns_header *	out
	)

Decodes the mdns header.

Parameters

packet	The mdns packet
out	The output mdns decoded header

Returns

0 Success, -1 on failure

decode_mdns_packet()

bool decode_mdns_packet

(

struct capture_packet *

cpac

)

Decode mdns packet.

Parameters

cpac	The capture packet structure

Returns

true Success, false otherwise

decode_mdns_queries()

int decode_mdns_queries	(	uint8_t *	payload,
		size_t	len,
		size_t *	first,
		uint16_t	nqueries,
		UT_array *	queries
	)

Decodes the mdns queries.

Parameters

	payload	The mdns payload
	len	The mdns payload length
[in,out]	first	The starting index to the queries field in the mdns payload. When done, this will be modified to be the starting index of the next field.
	nqueries	The number of queries
[in,out]	queries	The mdns_query_entry queries array

Returns

0 Success, -1 on failure

decode_mdns_query_name()

int decode_mdns_query_name	(	uint8_t *	payload,
		size_t	len,
		size_t *	first,
		char **	out
	)

get_mdns_query_offset()

uint16_t get_mdns_query_offset	(	uint8_t	low,
		uint8_t	high
	)