#include "rohc_decomp.h"
#include "rohc_decomp_internals.h"
#include "rohc_packets.h"
#include "rohc_utils.h"
#include "schemes/decomp_wlsb.h"
#include "schemes/ip_id_offset.h"
#include "schemes/decomp_list.h"
#include "ip.h"
#include "crc.h"
#include <stddef.h>
#include <stdbool.h>

Include dependency graph for rohc_decomp_rfc3095.h:

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Go to the source code of this file.

Data Structures
struct	rohc_extr_ip_bits

struct	rohc_extr_bits
	The bits extracted from ROHC UO* base headers. More...

struct	rohc_decoded_ip_values

struct	rohc_decoded_values
	The values decoded from the bits extracted from ROHC header. More...

struct	rohc_decomp_rfc3095_changes
	Store information about an IP header between the different decompressions of IP packets. More...

struct	rohc_decomp_rfc3095_ctxt
	The generic decompression context for RFC3095-based profiles. More...

Functions
bool	rohc_decomp_rfc3095_create (const struct rohc_decomp_ctxt const context, struct rohc_decomp_rfc3095_ctxt const persist_ctxt, struct rohc_decomp_volat_ctxt const volat_ctxt, rohc_trace_callback2_t trace_cb, void *const trace_cb_priv, const int profile_id)
	Create the RFC3095 volatile and persistent parts of the context. More...

void	rohc_decomp_rfc3095_destroy (struct rohc_decomp_rfc3095_ctxt const rfc3095_ctxt, const struct rohc_decomp_volat_ctxt const volat_ctxt)
	Destroy the context. More...

bool	rfc3095_decomp_parse_pkt (const struct rohc_decomp_ctxt const context, const struct rohc_buf rohc_packet, const size_t large_cid_len, rohc_packet_t const packet_type, struct rohc_decomp_crc const extr_crc, struct rohc_extr_bits const bits, size_t *const rohc_hdr_len)
	Parse one IR, IR-DYN, UO-0, UO-1, or UOR-2 packet. More...

int	rfc3095_parse_hdr_flags_fields (const struct rohc_decomp_ctxt const context, const uint8_t const flags, const uint8_t fields, const size_t length, bool const last_flag, struct rohc_extr_ip_bits *const bits)
	Parse the inner or outer IP header flags and fields. More...

int	rfc3095_parse_outer_hdr_flags_fields (const struct rohc_decomp_ctxt const context, const uint8_t const flags, const uint8_t fields, const size_t length, struct rohc_extr_ip_bits const bits)
	Parse the outer IP header flags and fields. More...

rohc_status_t	rfc3095_decomp_build_hdrs (const struct rohc_decomp const decomp, const struct rohc_decomp_ctxt const context, const rohc_packet_t packet_type, const struct rohc_decomp_crc const extr_crc, const struct rohc_decoded_values const decoded, const size_t payload_len, struct rohc_buf const uncomp_hdrs, size_t const uncomp_hdrs_len)
	Build the uncompressed headers. More...

rohc_status_t	rfc3095_decomp_decode_bits (const struct rohc_decomp_ctxt const context, const struct rohc_extr_bits const bits, const size_t payload_len, struct rohc_decoded_values *const decoded)
	Decode values from extracted bits. More...

void	rfc3095_decomp_update_ctxt (struct rohc_decomp_ctxt const context, const struct rohc_decoded_values const decoded, const size_t payload_len, bool *const do_change_mode)
	Update context with decoded values. More...

bool	rfc3095_decomp_attempt_repair (const struct rohc_decomp const decomp, const struct rohc_decomp_ctxt const context, const struct rohc_ts pkt_arrival_time, struct rohc_decomp_crc_corr_ctxt const crc_corr, struct rohc_extr_bits const extr_bits)
	Attempt a packet/context repair upon CRC failure. More...

uint32_t	rohc_decomp_rfc3095_get_sn (const struct rohc_decomp_ctxt *const context)
	Get the reference SN value of the context. More...

static bool	is_ipv4_pkt (const struct rohc_extr_ip_bits *const bits)
	Is the given IP header IPV4 wrt packet? More...

static bool	is_ipv4_rnd_pkt (const struct rohc_extr_ip_bits *const bits)
	Is the given IP header IPv4 and its IP-ID random wrt packet? More...

static bool	is_ipv4_non_rnd_pkt (const struct rohc_extr_ip_bits *const bits)
	Is the given IP header IPv4 and its IP-ID non-random wrt packet? More...

Function Documentation

◆ is_ipv4_non_rnd_pkt()

static bool is_ipv4_non_rnd_pkt ( const struct rohc_extr_ip_bits *const bits )

inlinestatic

Is the given IP header IPv4 and its IP-ID non-random wrt packet?

Parameters

bits	The bits extracted from packet

Returns: true if IPv4 and non-random, false otherwise

◆ is_ipv4_pkt()

static bool is_ipv4_pkt ( const struct rohc_extr_ip_bits *const bits )

inlinestatic

Is the given IP header IPV4 wrt packet?

Parameters

bits	The bits extracted from packet

Returns: true if IPv4, false if IPv6

◆ is_ipv4_rnd_pkt()

static bool is_ipv4_rnd_pkt ( const struct rohc_extr_ip_bits *const bits )

inlinestatic

Is the given IP header IPv4 and its IP-ID random wrt packet?

Parameters

bits	The bits extracted from packet

Returns: true if IPv4 and random, false otherwise

◆ rfc3095_decomp_attempt_repair()

bool rfc3095_decomp_attempt_repair	(	const struct rohc_decomp *const	decomp,
		const struct rohc_decomp_ctxt *const	context,
		const struct rohc_ts	pkt_arrival_time,
		struct rohc_decomp_crc_corr_ctxt *const	crc_corr,
		struct rohc_extr_bits *const	extr_bits
	)

Attempt a packet/context repair upon CRC failure.

Parameters

	decomp	The ROHC decompressor
	context	The decompression context
	pkt_arrival_time	The arrival time of the ROHC packet that caused the CRC failure
[in,out]	crc_corr	The context for corrections upon CRC failures
[in,out]	extr_bits	The bits extracted from the ROHC header

Returns: true if repair is possible, false if not

◆ rfc3095_decomp_build_hdrs()

rohc_status_t rfc3095_decomp_build_hdrs	(	const struct rohc_decomp *const	decomp,
		const struct rohc_decomp_ctxt *const	context,
		const rohc_packet_t	packet_type,
		const struct rohc_decomp_crc *const	extr_crc,
		const struct rohc_decoded_values *const	decoded,
		const size_t	payload_len,
		struct rohc_buf *const	uncomp_hdrs,
		size_t *const	uncomp_hdrs_len
	)

Build the uncompressed headers.

Todo:: check for uncomp_hdrs size before writing into it

Parameters

	decomp	The ROHC decompressor
	context	The decompression context
	packet_type	The type of ROHC packet
	extr_crc	The CRC bits extracted from the ROHC header
	decoded	The values decoded from ROHC header
	payload_len	The length of the packet payload
[out]	uncomp_hdrs	The buffer to store the uncompressed headers
[out]	uncomp_hdrs_len	The length of the uncompressed headers written into the buffer

Returns

Possible values:

ROHC_STATUS_OK if headers are built successfully,
ROHC_STATUS_BAD_CRC if headers do not match CRC,
ROHC_STATUS_OUTPUT_TOO_SMALL if the output buffer is too small

◆ rfc3095_decomp_decode_bits()

rohc_status_t rfc3095_decomp_decode_bits	(	const struct rohc_decomp_ctxt *const	context,
		const struct rohc_extr_bits *const	bits,
		const size_t	payload_len,
		struct rohc_decoded_values *const	decoded
	)

Decode values from extracted bits.

The following values are decoded:

SN
fields related to the outer IP header
fields related to the inner IP header (if it exists)

Other fields may be decoded by the profile-specific callback named decode_values_from_bits.

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

Parameters

	context	The decompression context
	bits	The bits extracted from the ROHC packet
	payload_len	The length of the packet payload (in bytes)
[out]	decoded	The corresponding decoded values

Returns: ROHC_STATUS_OK if decoding is successful, ROHC_STATUS_ERROR otherwise

◆ rfc3095_decomp_parse_pkt()

bool rfc3095_decomp_parse_pkt	(	const struct rohc_decomp_ctxt *const	context,
		const struct rohc_buf	rohc_packet,
		const size_t	large_cid_len,
		rohc_packet_t *const	packet_type,
		struct rohc_decomp_crc *const	extr_crc,
		struct rohc_extr_bits *const	bits,
		size_t *const	rohc_hdr_len
	)

Parse one IR, IR-DYN, UO-0, UO-1*, or UOR-2* packet.

Parameters

	context	The decompression context
	rohc_packet	The ROHC packet to decode
	large_cid_len	The length of the optional large CID field
[in,out]	packet_type	IN: The type of the ROHC packet to parse OUT: The type of the parsed ROHC packet
[out]	extr_crc	The CRC bits extracted from the ROHC header
[out]	bits	The bits extracted from the ROHC header
[out]	rohc_hdr_len	The length of the ROHC header (in bytes)

Returns: true if packet is successfully parsed, false otherwise

See also: parse_ir; parse_irdyn; parse_uo0; parse_uo1; parse_uo1rtp; parse_uo1id; parse_uo1ts; parse_uor2; parse_uor2rtp; parse_uor2id; parse_uor2ts

◆ rfc3095_decomp_update_ctxt()

void rfc3095_decomp_update_ctxt	(	struct rohc_decomp_ctxt *const	context,
		const struct rohc_decoded_values *const	decoded,
		const size_t	payload_len,
		bool *const	do_change_mode
	)

Update context with decoded values.

The following decoded values are updated in context:

SN
static & dynamic fields of the outer IP header
static & dynamic fields of the inner IP header (if it exists)
fields for the next header (optional, depends on profile)

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

Parameters

	context	The decompression context
	decoded	The decoded values to update in the context
	payload_len	The length of the packet payload
[out]	do_change_mode	Whether the profile context wants to change its operational mode or not

◆ rfc3095_parse_hdr_flags_fields()

int rfc3095_parse_hdr_flags_fields	(	const struct rohc_decomp_ctxt *const	context,
		const uint8_t *const	flags,
		const uint8_t *	fields,
		const size_t	length,
		bool *const	last_flag,
		struct rohc_extr_ip_bits *const	bits
	)

Parse the inner or outer IP header flags and fields.

Store the values in an IP header info structure.

  Inner IP header flags for RTP profile (5.7.5):

       0     1     2     3     4     5     6     7
     ..... ..... ..... ..... ..... ..... ..... .....
    | TOS | TTL | DF  | PR  | IPX | NBO | RND | ip2 |  if ip = 1
     ..... ..... ..... ..... ..... ..... ..... .....

  Inner IP header flags for non-RTP profiles (5.11.4):

       0     1     2     3     4     5     6     7
     ..... ..... ..... ..... ..... ..... ..... .....
    | TOS | TTL | DF  | PR  | IPX | NBO | RND |  0  |  if ip = 1
     ..... ..... ..... ..... ..... ..... ..... .....

  Outer IP header flags for RTP profile (5.7.5):

       0     1     2     3     4     5     6     7
     ..... ..... ..... ..... ..... ..... ..... .....
    | TOS2| TTL2| DF2 | PR2 |IPX2 |NBO2 |RND2 |  I2 |  if ip2 = 1
     ..... ..... ..... ..... ..... ..... ..... .....

  Inner IP header fields (5.7.5):

    ..... ..... ..... ..... ..... ..... ..... .....
   |         Type of Service/Traffic Class         |  if TOS = 1
    ..... ..... ..... ..... ..... ..... ..... .....
   |         Time to Live/Hop Limit                |  if TTL = 1
    ..... ..... ..... ..... ..... ..... ..... .....
   |         Protocol/Next Header                  |  if PR = 1
    ..... ..... ..... ..... ..... ..... ..... .....
   /         IP extension headers                  /  variable,
    ..... ..... ..... ..... ..... ..... ..... .....   if IPX = 1

  Outer IP header fields (5.7.5):

    ..... ..... ..... ..... ..... ..... ..... .....
   |         Type of Service/Traffic Class         |  if TOS2 = 1
    ..... ..... ..... ..... ..... ..... ..... .....
   |         Time to Live/Hop Limit                |  if TTL2 = 1
    ..... ..... ..... ..... ..... ..... ..... .....
   |         Protocol/Next Header                  |  if PR2 = 1
    ..... ..... ..... ..... ..... ..... ..... .....
   /         IP extension headers                  /  variable,
    ..... ..... ..... ..... ..... ..... ..... .....   if IPX2 = 1
   /                  IP-ID                        /  2 octets,
    ..... ..... ..... ..... ..... ..... ..... .....    if I2 = 1

Parameters

	context	The decompression context
	flags	The ROHC flags that indicate which IP fields are present in the packet
	fields	The ROHC packet part that contains some IP header fields
	length	The length of the ROHC packet part that contains some IP header fields
[out]	last_flag	Whether the parsing is performed for the RTP profile or not
[out]	bits	The bits extracted from extension 3

Returns: The data length read from the ROHC packet, -1 in case of error

◆ rfc3095_parse_outer_hdr_flags_fields()

int rfc3095_parse_outer_hdr_flags_fields	(	const struct rohc_decomp_ctxt *const	context,
		const uint8_t *const	flags,
		const uint8_t *	fields,
		const size_t	length,
		struct rohc_extr_ip_bits *const	bits
	)

Parse the outer IP header flags and fields.

Parameters

context	The decompression context
flags	The ROHC flags that indicate which IP fields are present in the packet
fields	The ROHC packet part that contain some IP header fields
length	The length of the ROHC packet part that contains some IP header fields
bits	OUT: The bits extracted from extension 3

Returns: The data length read from the ROHC packet, -1 in case of error

◆ rohc_decomp_rfc3095_create()

bool rohc_decomp_rfc3095_create	(	const struct rohc_decomp_ctxt *const	context,
		struct rohc_decomp_rfc3095_ctxt **const	persist_ctxt,
		struct rohc_decomp_volat_ctxt *const	volat_ctxt,
		rohc_trace_callback2_t	trace_cb,
		void *const	trace_cb_priv,
		const int	profile_id
	)

Create the RFC3095 volatile and persistent parts of the context.

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

Parameters

	context	The decompression context
[out]	persist_ctxt	The persistent part of the decompression context
[out]	volat_ctxt	The volatile part of the decompression context
	trace_cb	The function to call for printing traces
	trace_cb_priv	An optional private context, may be NULL
	profile_id	The ID of the associated decompression profile

Returns: true if the Uncompressed context was successfully created, false if a problem occurred

◆ rohc_decomp_rfc3095_destroy()

void rohc_decomp_rfc3095_destroy	(	struct rohc_decomp_rfc3095_ctxt *const	rfc3095_ctxt,
		const struct rohc_decomp_volat_ctxt *const	volat_ctxt
	)

Destroy the context.

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

Parameters

rfc3095_ctxt	The generic decompression context
volat_ctxt	The volatile part of the decompression context

◆ rohc_decomp_rfc3095_get_sn()

uint32_t rohc_decomp_rfc3095_get_sn ( const struct rohc_decomp_ctxt *const context )

Get the reference SN value of the context.

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

Parameters

context The decompression context

Returns: The reference SN value

Data Structures

Functions

Function Documentation

◆ is_ipv4_non_rnd_pkt()

◆ is_ipv4_pkt()

◆ is_ipv4_rnd_pkt()

◆ rfc3095_decomp_attempt_repair()

◆ rfc3095_decomp_build_hdrs()

◆ rfc3095_decomp_decode_bits()

◆ rfc3095_decomp_parse_pkt()

◆ rfc3095_decomp_update_ctxt()

◆ rfc3095_parse_hdr_flags_fields()

◆ rfc3095_parse_outer_hdr_flags_fields()

◆ rohc_decomp_rfc3095_create()

◆ rohc_decomp_rfc3095_destroy()

◆ rohc_decomp_rfc3095_get_sn()