ROHC generic decompression context for IP-only, UDP and UDP Lite profiles. More...

#include "d_generic.h"
#include "d_rtp.h"
#include "config.h"
#include "rohc_traces.h"
#include "rohc_time.h"
#include "rohc_debug.h"
#include "rohc_packets.h"
#include "rohc_bit_ops.h"
#include "wlsb.h"
#include "sdvl.h"
#include "crc.h"
#include <assert.h>

Include dependency graph for d_generic.c:

Defines
#define	IPV4_DYN_PART_SIZE 6
	The size (in bytes) of the IPv4 dynamic part.
#define	WEIGHT_OLD 1
#define	WEIGHT_NEW 1
#define	APPEND_BITS(field_descr, ext_no, field, field_nr, bits, bits_nr, max)
#define	APPEND_SN_BITS(ext_no, base, bits, bits_nr)
#define	APPEND_OUTER_IP_ID_BITS(ext_no, base, bits, bits_nr)
#define	APPEND_INNER_IP_ID_BITS(ext_no, base, bits, bits_nr)
#define	APPEND_TS_BITS(ext_no, base, bits, bits_nr)
Functions
void *	d_generic_create (void)
	Create the generic decompression context.
void	d_generic_destroy (void *context)
	Destroy the context.
int	d_generic_decode (struct rohc_decomp decomp, struct d_context context, const unsigned char const rohc_packet, const unsigned int rohc_length, const size_t add_cid_len, const size_t large_cid_len, unsigned char dest)
	Decode one IR, IR-DYN or UO* packet.
int	d_generic_get_sn (struct d_context *context)
	Get the reference SN value of the context.

Detailed Description

ROHC generic decompression context for IP-only, UDP and UDP Lite profiles.

Author:: Didier Barvaux <didier.barvaux@toulouse.viveris.com>; Didier Barvaux <didier@barvaux.org>; The hackers from ROHC for Linux; David Moreau from TAS

Define Documentation

#define APPEND_BITS	(	field_descr,
		ext_no,
		field,
		field_nr,
		bits,
		bits_nr,
		max
	)

Append new LSB bits to already extracted bits

#define APPEND_INNER_IP_ID_BITS	(	ext_no,
		base,
		bits,
		bits_nr
	)

Value:

APPEND_BITS(inner IP-ID, ext_no, \
                    (base)->inner_ip.id, (base)->inner_ip.id_nr, \
                    (bits), (bits_nr), 16)

Inner IP-ID: append new LSB bits to already extracted bits

#define APPEND_OUTER_IP_ID_BITS	(	ext_no,
		base,
		bits,
		bits_nr
	)

Value:

APPEND_BITS(outer IP-ID, ext_no, \
                    (base)->outer_ip.id, (base)->outer_ip.id_nr, \
                    (bits), (bits_nr), 16)

Outer IP-ID: append new LSB bits to already extracted bits

#define APPEND_SN_BITS	(	ext_no,
		base,
		bits,
		bits_nr
	)

Value:

APPEND_BITS(SN, ext_no, \
                    (base)->sn, (base)->sn_nr, \
                    (bits), (bits_nr), 32)

SN: append new LSB bits to already extracted bits

#define APPEND_TS_BITS	(	ext_no,
		base,
		bits,
		bits_nr
	)

Value:

APPEND_BITS(TS, ext_no, \
                    (base)->ts, (base)->ts_nr, \
                    (bits), (bits_nr), 32)

TS: append new LSB bits to already extracted bits

#define IPV4_DYN_PART_SIZE 6

The size (in bytes) of the IPv4 dynamic part.

According to RFC3095 section 5.7.7.4: 1 (TOS) + 1 (TTL) + 2 (IP-ID) + 1 (flags) + 1 (header list) = 6 bytes

The size of the generic extension header list field is considered constant because generic extension header list is not supported yet and thus 1 byte of zero is used.

#define WEIGHT_NEW 1

Constant to compute inter-arrival time between the received packets

#define WEIGHT_OLD 1

Constant to compute inter-arrival time between the received packets

Function Documentation

void* d_generic_create ( void )

Create the generic decompression context.

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

Returns:: The newly-created generic decompression context

Referenced by d_ip_create(), d_rtp_create(), d_udp_create(), and d_udp_lite_create().

int d_generic_decode	(	struct rohc_decomp *	decomp,
		struct d_context *	context,
		const unsigned char *const	rohc_packet,
		const unsigned int	rohc_length,
		const size_t	add_cid_len,
		const size_t	large_cid_len,
		unsigned char *	dest
	)

Decode one IR, IR-DYN or UO* packet.

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

Parameters:

decomp	The ROHC decompressor
context	The decompression context
rohc_packet	The ROHC packet to decode
rohc_length	The length of the ROHC packet
add_cid_len	The length of the optional Add-CID field
large_cid_len	The length of the optional large CID field
dest	OUT: The decoded IP packet