ROHC generic list decompression. More...

#include "schemes/decomp_list.h"
#include "rohc_bit_ops.h"
#include <string.h>
#include <assert.h>

Include dependency graph for decomp_list.c:

Functions
static int	rohc_list_decode (struct list_decomp decomp, const uint8_t packet, size_t packet_len)
	Decompress the compressed list in given packet. More...

static int	rohc_list_decode_type_0 (struct list_decomp const decomp, const uint8_t packet, size_t packet_len, const unsigned int gen_id, const int ps, const uint8_t m)
	Decode an extension list type 0. More...

static int	rohc_list_decode_type_1 (struct list_decomp const decomp, const uint8_t packet, size_t packet_len, const unsigned int gen_id, const int ps, const int xi_1)
	Decode an extension list type 1. More...

static int	rohc_list_decode_type_2 (struct list_decomp const decomp, const uint8_t packet, size_t packet_len, const unsigned int gen_id)
	Decode an extension list type 2. More...

static int	rohc_list_decode_type_3 (struct list_decomp const decomp, const uint8_t packet, size_t packet_len, const unsigned int gen_id, const int ps, const int xi_1)
	Decode an extension list type 3. More...

static bool	rohc_list_is_gen_id_known (const struct list_decomp *const decomp, const unsigned int gen_id)
	Check if the given gen_id is known, ie. present in list table. More...

static int	rohc_list_parse_insertion_scheme (struct list_decomp const decomp, const uint8_t packet, size_t packet_len, const int ps, const int xi_1, const size_t items_nr, const struct rohc_list const ref_list, struct rohc_list const ins_list)
	Process the insertion scheme of the list compression. More...

static int	rohc_list_parse_removal_scheme (struct list_decomp const decomp, const uint8_t packet, size_t packet_len, const struct rohc_list const ref_list, struct rohc_list const rem_list)
	Process the removal scheme of the list compression. More...

static int	rohc_list_decode_mask (struct list_decomp const decomp, const char const descr, const uint8_t const packet, const size_t packet_len, uint8_t mask[2], size_t const mask_len)
	Determine the number of bits set to 1 in the insertion/removal bit mask. More...

static size_t	rohc_list_get_xi_nr (const uint8_t ins_mask[2], const size_t ins_mask_len)
	Determine the number of indexes in the XI list. More...

static size_t	rohc_list_get_xi_len (const size_t xi_nr, const int ps)
	Determine the length of the XI list. More...

static uint8_t	rohc_list_get_xi_type_0 (const int ps, const size_t xi_index, const uint8_t const data, bool const is_item_present)
	Get the XI information, ie. the X bit and the index value. More...

static uint8_t	rohc_list_get_xi_type_2or3 (const int ps, const size_t xi_index, const uint8_t xi_1, const uint8_t const data, bool const is_item_present)
	Get the XI information, ie. the X bit and the index value. More...

static uint8_t	rohc_get_bit (const uint8_t byte, const size_t pos)
	Get the bit in the given byte at the given position. More...

int	rohc_list_decode_maybe (struct list_decomp decomp, const uint8_t packet, size_t packet_len)
	Decompress the compressed list in given packet if present. More...

bool	rohc_decomp_list_create_item (struct list_decomp const decomp, const unsigned int xi_index, const unsigned int xi_index_value, const uint8_t const rohc_packet, const size_t rohc_max_len, size_t *const item_length)
	Create a list item from a XI item. More...

Detailed Description

ROHC generic list decompression.

Author: Didier Barvaux didie.nosp@m.r@ba.nosp@m.rvaux.nosp@m..org

Function Documentation

bool rohc_decomp_list_create_item	(	struct list_decomp *const	decomp,
		const unsigned int	xi_index,
		const unsigned int	xi_index_value,
		const uint8_t *const	rohc_packet,
		const size_t	rohc_max_len,
		size_t *const	item_length
	)

Create a list item from a XI item.

Parameters

	decomp	The context for list decompression
	xi_index	The XI index
	xi_index_value	The XI index value
	rohc_packet	The beginning of the XI item in the ROHC header
	rohc_max_len	The remaining length (in bytes) of the ROHC header
[out]	item_length	The length (in bytes) of the created item

Returns: true if item was successfully created, false if a problem occurred

static uint8_t rohc_get_bit	(	const uint8_t	byte,
		const size_t	pos
	)

static

Get the bit in the given byte at the given position.

Parameters

byte	The byte to analyse
pos	The position between 0 and 7

Returns: The requested bit

static int rohc_list_decode	(	struct list_decomp *	decomp,
		const uint8_t *	packet,
		size_t	packet_len
	)

static

Decompress the compressed list in given packet.

Parameters

decomp	The list decompressor
packet	The ROHC packet to decompress
packet_len	The remaining length of the packet to decode (in bytes)

Returns: The size of the compressed list in packet in case of success, -1 in case of failure

static int rohc_list_decode_mask	(	struct list_decomp *const	decomp,
		const char *const	descr,
		const uint8_t *const	packet,
		const size_t	packet_len,
		uint8_t	mask[2],
		size_t *const	mask_len
	)

static

Determine the number of bits set to 1 in the insertion/removal bit mask.

Parameters

	decomp	The list decompressor
	descr	The name of bit mask being decoded
	packet	The ROHC packet to decompress
	packet_len	The length (in bytes) of the packet to decompress
[out]	mask	The insertion/removal bit mask on 1-2 bytes
[out]	mask_len	The length of the insertion/removal mask (in bits)

Returns

In case of success, the number of bytes read in the given packet, ie. the length of the compressed list
-1 in case of failure

int rohc_list_decode_maybe	(	struct list_decomp *	decomp,
		const uint8_t *	packet,
		size_t	packet_len
	)

Decompress the compressed list in given packet if present.

Parameters

decomp	The list decompressor
packet	The ROHC packet to decompress
packet_len	The remaining length of the packet to decode (in bytes)

Returns: The size of the compressed list in packet in case of success, -1 in case of failure

static int rohc_list_decode_type_0	(	struct list_decomp *const	decomp,
		const uint8_t *	packet,
		size_t	packet_len,
		const unsigned int	gen_id,
		const int	ps,
		const uint8_t	m
	)

static

Decode an extension list type 0.

Parameters

decomp	The list decompressor
packet	The ROHC packet to decompress
packet_len	The length (in bytes) of the packet to decompress
gen_id	The id of the current list, maybe ROHC_LIST_GEN_ID_ANON if not defined
ps	The ps field
m	The m field

Returns

In case of success, the number of bytes read in the given packet, ie. the length of the compressed list
-1 in case of failure

static int rohc_list_decode_type_1	(	struct list_decomp *const	decomp,
		const uint8_t *	packet,
		size_t	packet_len,
		const unsigned int	gen_id,
		const int	ps,
		const int	xi_1
	)

static

Decode an extension list type 1.

Parameters

decomp	The list decompressor
packet	The ROHC packet to decompress
packet_len	The length (in bytes) of the packet to decompress
gen_id	The id of the current list, maybe ROHC_LIST_GEN_ID_ANON if not defined
ps	The ps field
xi_1	The XI 1 field if PS = 1 (4-bit XI)

Returns

In case of success, the number of bytes read in the given packet, ie. the length of the compressed list
-1 in case of failure

static int rohc_list_decode_type_2	(	struct list_decomp *const	decomp,
		const uint8_t *	packet,
		size_t	packet_len,
		const unsigned int	gen_id
	)

static

Decode an extension list type 2.

Parameters

decomp	The list decompressor
packet	The ROHC packet to decompress
packet_len	The length (in bytes) of the packet to decompress
gen_id	The id of the current list, maybe ROHC_LIST_GEN_ID_ANON if not defined

Returns

In case of success, the number of bytes read in the given packet, ie. the length of the compressed list
-1 in case of failure

static int rohc_list_decode_type_3	(	struct list_decomp *const	decomp,
		const uint8_t *	packet,
		size_t	packet_len,
		const unsigned int	gen_id,
		const int	ps,
		const int	xi_1
	)

static

Decode an extension list type 3.

Parameters

decomp	The list decompressor
packet	The ROHC packet to decompress
packet_len	The length (in bytes) of the packet to decompress
gen_id	The id of the current list maybe ROHC_LIST_GEN_ID_ANON if not defined
ps	The ps field
xi_1	The XI 1 field if PS = 1 (4-bit XI)

Returns

In case of success, the number of bytes read in the given packet, ie. the length of the compressed list
-1 in case of failure

static size_t rohc_list_get_xi_len	(	const size_t	xi_nr,
		const int	ps
	)

static

Determine the length of the XI list.

Parameters

xi_nr	The number of indexes in the XI list
ps	The PS bit

Returns: The length of the XI list (in bytes)

static size_t rohc_list_get_xi_nr	(	const uint8_t	ins_mask[2],
		const size_t	ins_mask_len
	)

static

Determine the number of indexes in the XI list.

Parameters

ins_mask	The insertion bit mask
ins_mask_len	The length of the insertion bit mask (in bits)

Returns: The number of indexes in the XI list

static uint8_t rohc_list_get_xi_type_0	(	const int	ps,
		const size_t	xi_index,
		const uint8_t *const	data,
		bool *const	is_item_present
	)

static

Get the XI information, ie. the X bit and the index value.

Parameters

	ps	The PS bit
	xi_index	The index of the XI
	data	The data to parse
[out]	is_item_present	Whether the XI item shall be present or not

Returns: The value of the XI index

static uint8_t rohc_list_get_xi_type_2or3	(	const int	ps,
		const size_t	xi_index,
		const uint8_t	xi_1,
		const uint8_t *const	data,
		bool *const	is_item_present
	)

static

Get the XI information, ie. the X bit and the index value.

Parameters

	ps	The PS bit
	xi_index	The index of the XI
	xi_1	The XI 1 field if PS = 1 (4-bit XI)
	data	The data to parse
[out]	is_item_present	Whether the XI item shall be present or not

Returns: The value of the XI index

static bool rohc_list_is_gen_id_known	(	const struct list_decomp *const	decomp,
		const unsigned int	gen_id
	)

static

Check if the given gen_id is known, ie. present in list table.

Parameters

decomp	The list decompressor
gen_id	The gen_id to check for

Returns: true if successful, false otherwise

static int rohc_list_parse_insertion_scheme	(	struct list_decomp *const	decomp,
		const uint8_t *	packet,
		size_t	packet_len,
		const int	ps,
		const int	xi_1,
		const size_t	items_nr,
		const struct rohc_list *const	ref_list,
		struct rohc_list *const	ins_list
	)

static

Process the insertion scheme of the list compression.

Parameters

	decomp	The list decompressor
	packet	The ROHC packet to decompress
	packet_len	The length (in bytes) of the packet to decompress
	ps	The PS bit
	xi_1	The XI 1 field if PS = 1 (4-bit XI)
	items_nr	The number of items in the initial list
	ref_list	The list to use as reference
[out]	ins_list	The list with new items added

Returns

In case of success, the number of bytes read in the given packet, ie. the length of the insertion mask
-1 in case of failure

static int rohc_list_parse_removal_scheme	(	struct list_decomp *const	decomp,
		const uint8_t *	packet,
		size_t	packet_len,
		const struct rohc_list *const	ref_list,
		struct rohc_list *const	rem_list
	)

static

Process the removal scheme of the list compression.

Parameters

	decomp	The list decompressor
	packet	The ROHC packet to decompress
	packet_len	The length (in bytes) of the packet to decompress
	ref_list	The list to use as reference
[in,out]	rem_list	in: the initial list, out: the list with superfluous items removed

Returns

In case of success, the number of bytes read in the given packet, ie. the length of the removal mask
-1 in case of failure

Functions

Detailed Description

Function Documentation