ROHC CRC routines. More...

#include "ip.h"
#include "dllexport.h"
#include <stdbool.h>

Include dependency graph for crc.h:

This graph shows which files directly or indirectly include this file:

Defines
#define	CRC_INIT_3 0x7
	The CRC-3 initial value.
#define	CRC_INIT_7 0x7f
	The CRC-7 initial value.
#define	CRC_INIT_8 0xff
	The CRC-8 initial value.
#define	CRC_INIT_FCS32 0xffffffff
#define	CRC_FCS32_LEN 4U
Enumerations
enum	rohc_crc_type_t { ROHC_CRC_TYPE_NONE = 0, ROHC_CRC_TYPE_3 = 3, ROHC_CRC_TYPE_7 = 7, ROHC_CRC_TYPE_8 = 8 }
Functions
bool ROHC_EXPORT	rohc_crc_init_table (uint8_t *const table, const rohc_crc_type_t crc_type)
	Initialize a CRC table given a 256-byte table and the CRC type to use.
uint8_t ROHC_EXPORT	crc_calculate (const rohc_crc_type_t crc_type, const uint8_t const data, const size_t length, const uint8_t init_val, const uint8_t const crc_table)
	Calculate the checksum for the given data.
uint32_t ROHC_EXPORT	crc_calc_fcs32 (const uint8_t *const data, const size_t length, const uint32_t init_val)
	Optimized CRC FCS-32 calculation using a table.
uint8_t ROHC_EXPORT	compute_crc_static (const uint8_t const ip, const uint8_t const ip2, const uint8_t const next_header, const rohc_crc_type_t crc_type, const uint8_t init_val, const uint8_t const crc_table)
	Compute the CRC-STATIC part of an IP header.
uint8_t ROHC_EXPORT	compute_crc_dynamic (const uint8_t const ip, const uint8_t const ip2, const uint8_t const next_header, const rohc_crc_type_t crc_type, const uint8_t init_val, const uint8_t const crc_table)
	Compute the CRC-DYNAMIC part of an IP header.
uint8_t ROHC_EXPORT	udp_compute_crc_static (const uint8_t const ip, const uint8_t const ip2, const uint8_t const next_header, const rohc_crc_type_t crc_type, const uint8_t init_val, const uint8_t const crc_table)
	Compute the CRC-STATIC part of an UDP or UDP-Lite header.
uint8_t ROHC_EXPORT	udp_compute_crc_dynamic (const uint8_t const ip, const uint8_t const ip2, const uint8_t const next_header, const rohc_crc_type_t crc_type, const uint8_t init_val, const uint8_t const crc_table)
	Compute the CRC-DYNAMIC part of an UDP or UDP-Lite header.
uint8_t ROHC_EXPORT	esp_compute_crc_static (const uint8_t const ip, const uint8_t const ip2, const uint8_t const next_header, const rohc_crc_type_t crc_type, const uint8_t init_val, const uint8_t const crc_table)
	Compute the CRC-STATIC part of an ESP header.
uint8_t ROHC_EXPORT	esp_compute_crc_dynamic (const uint8_t const ip, const uint8_t const ip2, const uint8_t const next_header, const rohc_crc_type_t crc_type, const uint8_t init_val, const uint8_t const crc_table)
	Compute the CRC-DYNAMIC part of an ESP header.
uint8_t ROHC_EXPORT	rtp_compute_crc_static (const uint8_t const ip, const uint8_t const ip2, const uint8_t const next_header, const rohc_crc_type_t crc_type, const uint8_t init_val, const uint8_t const crc_table)
	Compute the CRC-STATIC part of a RTP header.
uint8_t ROHC_EXPORT	rtp_compute_crc_dynamic (const uint8_t const ip, const uint8_t const ip2, const uint8_t const next_header, const rohc_crc_type_t crc_type, const uint8_t init_val, const uint8_t const crc_table)
	Compute the CRC-DYNAMIC part of a RTP header.
uint8_t ROHC_EXPORT	tcp_compute_crc_static (const uint8_t const ip, const uint8_t const ip2, const uint8_t const next_header, const rohc_crc_type_t crc_type, const uint8_t init_val, const uint8_t const crc_table)
	Compute the CRC-STATIC part of an TCP header.
uint8_t ROHC_EXPORT	tcp_compute_crc_dynamic (const uint8_t const ip, const uint8_t const ip2, const uint8_t const next_header, const rohc_crc_type_t crc_type, const uint8_t init_val, const uint8_t const crc_table)
	Compute the CRC-DYNAMIC part of an TCP header.

Detailed Description

ROHC CRC routines.

Author:: Didier Barvaux <didier.barvaux@toulouse.viveris.com>; Didier Barvaux <didier@barvaux.org>; FWX <rohc_team@dialine.fr>

Define Documentation

#define CRC_FCS32_LEN 4U

The length (in bytes) of the FCS-32 CRC

#define CRC_INIT_3 0x7

The CRC-3 initial value.

#define CRC_INIT_7 0x7f

The CRC-7 initial value.

#define CRC_INIT_8 0xff

The CRC-8 initial value.

#define CRC_INIT_FCS32 0xffffffff

The FCS-32 initial value

Enumeration Type Documentation

enum rohc_crc_type_t

The different types of CRC used to protect ROHC headers

Enumerator:

ROHC_CRC_TYPE_NONE	No CRC selected
ROHC_CRC_TYPE_3	The CRC-3 type
ROHC_CRC_TYPE_7	The CRC-7 type
ROHC_CRC_TYPE_8	The CRC-8 type

Function Documentation

uint8_t ROHC_EXPORT compute_crc_dynamic	(	const uint8_t *const	ip,
		const uint8_t *const	ip2,
		const uint8_t *const	next_header,
		const rohc_crc_type_t	crc_type,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Compute the CRC-DYNAMIC part of an IP header.

Concerned fields are:

bytes 3-4, 5-6, 11-12 in original IPv4 header
bytes 5-6 in original IPv6 header

Parameters:

ip	The outer IP packet
ip2	The inner IP packet if there is 2 IP headers, NULL otherwise
next_header	The next header located after the IP header(s)
crc_type	The type of CRC
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

uint8_t ROHC_EXPORT compute_crc_static	(	const uint8_t *const	ip,
		const uint8_t *const	ip2,
		const uint8_t *const	next_header,
		const rohc_crc_type_t	crc_type,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Compute the CRC-STATIC part of an IP header.

Concerned fields are: all fields expect those for CRC-DYNAMIC

bytes 1-2, 7-10, 13-20 in original IPv4 header
bytes 1-4, 7-40 in original IPv6 header

This function is one of the functions that must exist in one profile for the framework to work.

Parameters:

ip	The outer IP packet
ip2	The inner IP packet if there is 2 IP headers, NULL otherwise
next_header	The next header located after the IP header(s)
crc_type	The type of CRC
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

uint32_t ROHC_EXPORT crc_calc_fcs32	(	const uint8_t *const	data,
		const size_t	length,
		const uint32_t	init_val
	)

Optimized CRC FCS-32 calculation using a table.

Parameters:

data	The data to compute the CRC for
length	The size of the data
init_val	The initial value of the CRC

Returns:: The 32-bit CRC

uint8_t ROHC_EXPORT crc_calculate	(	const rohc_crc_type_t	crc_type,
		const uint8_t *const	data,
		const size_t	length,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Calculate the checksum for the given data.

Parameters:

crc_type	The CRC type
data	The data to calculate the checksum on
length	The length of the data
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

uint8_t ROHC_EXPORT esp_compute_crc_dynamic	(	const uint8_t *const	ip,
		const uint8_t *const	ip2,
		const uint8_t *const	next_header,
		const rohc_crc_type_t	crc_type,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Compute the CRC-DYNAMIC part of an ESP header.

Concerned fields are:

bytes 5-8 in original ESP header

Parameters:

ip	The outer IP packet
ip2	The inner IP packet if there is 2 IP headers, NULL otherwise
next_header	The next header located after the IP header(s)
crc_type	The type of CRC
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

uint8_t ROHC_EXPORT esp_compute_crc_static	(	const uint8_t *const	ip,
		const uint8_t *const	ip2,
		const uint8_t *const	next_header,
		const rohc_crc_type_t	crc_type,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Compute the CRC-STATIC part of an ESP header.

Concerned fields are: all fields expect those for CRC-DYNAMIC

bytes 1-4 in original ESP header

Parameters:

ip	The outer IP packet
ip2	The inner IP packet if there is 2 IP headers, NULL otherwise
next_header	The next header located after the IP header(s)
crc_type	The type of CRC
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

bool ROHC_EXPORT rohc_crc_init_table	(	uint8_t *const	table,
		const rohc_crc_type_t	crc_type
	)

Initialize a CRC table given a 256-byte table and the CRC type to use.

Parameters:

table	IN/OUT: The 256-byte table to initialize
crc_type	The type of CRC to initialize the table for

Returns:: true in case of success, false in case of failure

uint8_t ROHC_EXPORT rtp_compute_crc_dynamic	(	const uint8_t *const	ip,
		const uint8_t *const	ip2,
		const uint8_t *const	next_header,
		const rohc_crc_type_t	crc_type,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Compute the CRC-DYNAMIC part of a RTP header.

Concerned fields are:

bytes 2, 3-4, 5-8 in original RTP header

Parameters:

ip	The outer IP packet
ip2	The inner IP packet if there is 2 IP headers, NULL otherwise
next_header	The next header located after the IP header(s)
crc_type	The type of CRC
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

uint8_t ROHC_EXPORT rtp_compute_crc_static	(	const uint8_t *const	ip,
		const uint8_t *const	ip2,
		const uint8_t *const	next_header,
		const rohc_crc_type_t	crc_type,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Compute the CRC-STATIC part of a RTP header.

Concerned fields are: all fields expect those for CRC-DYNAMIC

bytes 1, 9-12 (and CSRC list) in original RTP header

Parameters:

ip	The outer IP packet
ip2	The inner IP packet if there is 2 IP headers, NULL otherwise
next_header	The next header located after the IP header(s)
crc_type	The type of CRC
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

uint8_t ROHC_EXPORT tcp_compute_crc_dynamic	(	const uint8_t *const	ip,
		const uint8_t *const	ip2,
		const uint8_t *const	next_header,
		const rohc_crc_type_t	crc_type,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Compute the CRC-DYNAMIC part of an TCP header.

Concerned fields are:

bytes 5-20 in original TCP header
TCP options

Parameters:

ip	The outer IP packet
ip2	The inner IP packet if there is 2 IP headers, NULL otherwise
next_header	The next header located after the IP header(s)
crc_type	The type of CRC
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

uint8_t ROHC_EXPORT tcp_compute_crc_static	(	const uint8_t *const	ip,
		const uint8_t *const	ip2,
		const uint8_t *const	next_header,
		const rohc_crc_type_t	crc_type,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Compute the CRC-STATIC part of an TCP header.

Concerned fields are: all fields expect those for CRC-DYNAMIC

bytes 1-4 in original TCP header

Parameters:

ip	The outer IP packet
ip2	The inner IP packet if there is 2 IP headers, NULL otherwise
next_header	The next header located after the IP header(s)
crc_type	The type of CRC
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

uint8_t ROHC_EXPORT udp_compute_crc_dynamic	(	const uint8_t *const	ip,
		const uint8_t *const	ip2,
		const uint8_t *const	next_header,
		const rohc_crc_type_t	crc_type,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Compute the CRC-DYNAMIC part of an UDP or UDP-Lite header.

Concerned fields are:

bytes 5-6, 7-8 in original UDP header

Parameters:

ip	The outer IP packet
ip2	The inner IP packet if there is 2 IP headers, NULL otherwise
next_header	The next header located after the IP header(s)
crc_type	The type of CRC
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

uint8_t ROHC_EXPORT udp_compute_crc_static	(	const uint8_t *const	ip,
		const uint8_t *const	ip2,
		const uint8_t *const	next_header,
		const rohc_crc_type_t	crc_type,
		const uint8_t	init_val,
		const uint8_t *const	crc_table
	)

Compute the CRC-STATIC part of an UDP or UDP-Lite header.

Concerned fields are: all fields expect those for CRC-DYNAMIC

bytes 1-4 in original UDP header

Parameters:

ip	The outer IP packet
ip2	The inner IP packet if there is 2 IP headers, NULL otherwise
next_header	The next header located after the IP header(s)
crc_type	The type of CRC
init_val	The initial CRC value
crc_table	The pre-computed table for fast CRC computation

Returns:: The checksum

Defines

Enumerations

Functions

Detailed Description

Define Documentation

Enumeration Type Documentation

Function Documentation