Generic framework for RFC3095-based compression profiles such as IP-only, UDP, UDP-Lite, ESP, and RTP profiles. More...

#include "rohc_comp_internals.h"
#include "rohc_packets.h"
#include "schemes/comp_list.h"
#include "ip.h"
#include "crc.h"
#include <stdlib.h>

Include dependency graph for rohc_comp_rfc3095.h:

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

Go to the source code of this file.

Data Structures
struct	ipv4_header_info
	Store information about an IPv4 header between the different compressions of IP packets. More...

struct	ipv6_header_info
	Store information about an IPv6 header between the different compressions of IP packets. More...

struct	ip_header_info
	Store information about an IP (IPv4 or IPv6) header between the different compressions of IP packets. More...

struct	generic_tmp_vars
	Structure that contains variables that are used during one single compression of packet. More...

struct	rohc_comp_rfc3095_ctxt
	The generic decompression context for RFC3095-based profiles. More...

Functions
bool	rohc_comp_rfc3095_create (struct rohc_comp_ctxt const context, const rohc_lsb_shift_t sn_shift, const struct net_pkt const packet)
	Create a new context and initialize it thanks to the given IP packet. More...

void	rohc_comp_rfc3095_destroy (struct rohc_comp_ctxt *const context)
	Destroy the context. More...

bool	rohc_comp_rfc3095_check_profile (const struct rohc_comp const comp, const struct net_pkt const packet)
	Check if the given packet corresponds to an IP-based profile. More...

rohc_ext_t	decide_extension (const struct rohc_comp_ctxt *const context)
	Decide what extension shall be used in the UO-1-ID/UOR-2 packet. More...

int	rohc_comp_rfc3095_encode (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t const rohc_pkt, const size_t rohc_pkt_max_len, rohc_packet_t const packet_type, size_t *const payload_offset)
	Encode an IP packet according to a pattern decided by several different factors. More...

bool	rohc_comp_rfc3095_feedback (struct rohc_comp_ctxt const context, const enum rohc_feedback_type feedback_type, const uint8_t const packet, const size_t packet_len, const uint8_t *const feedback_data, const size_t feedback_data_len)
	Update the profile when feedback is received. More...

void	rohc_comp_rfc3095_decide_state (struct rohc_comp_ctxt *const context)
	Decide the state that should be used for the next packet. More...

void	rohc_get_ipid_bits (const struct rohc_comp_ctxt const context, size_t const nr_innermost_bits, size_t *const nr_outermost_bits)
	Get the number of non-random outer/inner IP-ID bits. More...

bool	rohc_comp_rfc3095_is_sn_possible (const struct rohc_comp_rfc3095_ctxt *const rfc3095_ctxt, const size_t bits_nr, const size_t add_bits_nr)
	Are the given SN field sizes possible? More...

static bool	no_outer_ip_id_bits_required (const struct rohc_comp_rfc3095_ctxt *const ctxt)
	Does the outer IP header require to transmit no non-random IP-ID bit? More...

static bool	is_outer_ip_id_bits_possible (const struct rohc_comp_rfc3095_ctxt *const ctxt, const size_t max_ip_id_bits_nr)
	May the outer IP header transmit the required non-random IP-ID bits? More...

static bool	no_inner_ip_id_bits_required (const struct rohc_comp_rfc3095_ctxt *const ctxt)
	Does the inner IP header require to transmit no non-random IP-ID bit? More...

static bool	is_inner_ip_id_bits_possible (const struct rohc_comp_rfc3095_ctxt *const ctxt, const size_t max_ip_id_bits_nr)
	May the inner IP header transmit the required non-random IP-ID bits? More...

static size_t	get_nr_ipv4_non_rnd (const struct rohc_comp_rfc3095_ctxt *const ctxt)
	How many IP headers are IPv4 headers with non-random IP-IDs ? More...

static size_t	get_nr_ipv4_non_rnd_with_bits (const struct rohc_comp_rfc3095_ctxt *const ctxt)
	How many IP headers are IPv4 headers with non-random IP-IDs and some bits to transmit ? More...

Detailed Description

Generic framework for RFC3095-based compression profiles such as IP-only, UDP, UDP-Lite, ESP, and RTP profiles.

Author: Didier Barvaux didie.nosp@m.r.ba.nosp@m.rvaux.nosp@m.@tou.nosp@m.louse.nosp@m..viv.nosp@m.eris..nosp@m.com; Didier Barvaux didie.nosp@m.r@ba.nosp@m.rvaux.nosp@m..org

Function Documentation

rohc_ext_t decide_extension ( const struct rohc_comp_ctxt *const context )

Decide what extension shall be used in the UO-1-ID/UOR-2 packet.

Extensions 0, 1 & 2 are IPv4 only because of the IP-ID.

Parameters

context The compression context

Returns: The extension code among ROHC_EXT_NONE, ROHC_EXT_0, ROHC_EXT_1 and ROHC_EXT_3 if successful, ROHC_EXT_UNKNOWN otherwise

static size_t get_nr_ipv4_non_rnd ( const struct rohc_comp_rfc3095_ctxt *const ctxt )

inlinestatic

How many IP headers are IPv4 headers with non-random IP-IDs ?

Parameters

ctxt	The generic decompression context

Returns: The number of IPv4 headers with non-random IP-ID fields

static size_t get_nr_ipv4_non_rnd_with_bits ( const struct rohc_comp_rfc3095_ctxt *const ctxt )

inlinestatic

How many IP headers are IPv4 headers with non-random IP-IDs and some bits to transmit ?

Parameters

ctxt	The generic decompression context

Returns: The number of IPv4 headers with non-random IP-ID fields and some bits to transmit

static bool is_inner_ip_id_bits_possible	(	const struct rohc_comp_rfc3095_ctxt *const	ctxt,
		const size_t	max_ip_id_bits_nr
	)

inlinestatic

May the inner IP header transmit the required non-random IP-ID bits?

Parameters

ctxt	The generic decompression context
max_ip_id_bits_nr	The maximum number of IP-ID bits that may be transmitted

Returns: true if the required IP-ID bits may be transmitted, false otherwise

static bool is_outer_ip_id_bits_possible	(	const struct rohc_comp_rfc3095_ctxt *const	ctxt,
		const size_t	max_ip_id_bits_nr
	)

inlinestatic

May the outer IP header transmit the required non-random IP-ID bits?

Parameters

ctxt	The generic decompression context
max_ip_id_bits_nr	The maximum number of IP-ID bits that may be transmitted

Returns: true if the required IP-ID bits may be transmitted, false otherwise

static bool no_inner_ip_id_bits_required ( const struct rohc_comp_rfc3095_ctxt *const ctxt )

inlinestatic

Does the inner IP header require to transmit no non-random IP-ID bit?

Parameters

ctxt	The generic decompression context

Returns: true if no required inner IP-ID bit shall be transmitted, false otherwise

static bool no_outer_ip_id_bits_required ( const struct rohc_comp_rfc3095_ctxt *const ctxt )

inlinestatic

Does the outer IP header require to transmit no non-random IP-ID bit?

Parameters

ctxt	The generic decompression context

Returns: true if no required outer IP-ID bit shall be transmitted, false otherwise

bool rohc_comp_rfc3095_check_profile	(	const struct rohc_comp *const	comp,
		const struct net_pkt *const	packet
	)

Check if the given packet corresponds to an IP-based profile.

Conditions are:

the version of the outer IP header is 4 or 6
if the outer IP header is IPv4, it does not contain options
the outer IP header is not an IP fragment
if there are at least 2 IP headers, the version of the inner IP header is 4 or 6
if there are at least 2 IP headers and if the inner IP header is IPv4, it does not contain options
if there are at least 2 IP headers, the inner IP header is not an IP fragment

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

Parameters

comp	The ROHC compressor
packet	The packet to check

Returns

Whether the IP packet corresponds to the profile:

true if the IP packet corresponds to the profile,
false if the IP packet does not correspond to the profile

bool rohc_comp_rfc3095_create	(	struct rohc_comp_ctxt *const	context,
		const rohc_lsb_shift_t	sn_shift,
		const struct net_pkt *const	packet
	)

Create a new context and initialize it thanks to the given IP packet.

Parameters

context	The compression context
sn_shift	The shift parameter (p) to use for encoding SN with W-LSB
packet	The packet given to initialize the new context

Returns: bool if successful, false otherwise

void rohc_comp_rfc3095_decide_state ( struct rohc_comp_ctxt *const context )

Decide the state that should be used for the next packet.

The three states are:

Initialization and Refresh (IR),
First Order (FO),
Second Order (SO).

Parameters

context The compression context

void rohc_comp_rfc3095_destroy ( struct rohc_comp_ctxt *const context )

Destroy the context.

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

Parameters

context The compression context

int rohc_comp_rfc3095_encode	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len,
		rohc_packet_t *const	packet_type,
		size_t *const	payload_offset
	)

Encode an IP packet according to a pattern decided by several different factors.

parse uncompressed packet (done in rohc_compress4)
detect changes between the new uncompressed packet and the context
decide new compressor state
determine how many bytes are required for every field
decide which packet to send
code the ROHC header
copy the packet payload (done in rohc_compress4)
update the context with the new headers

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

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
rohc_pkt	OUT: The ROHC packet
rohc_pkt_max_len	The maximum length of the ROHC packet
packet_type	OUT: The type of ROHC packet that is created
payload_offset	OUT: The offset for the payload in the IP packet

Returns: The length of the ROHC packet if successful, -1 otherwise

bool rohc_comp_rfc3095_feedback	(	struct rohc_comp_ctxt *const	context,
		const enum rohc_feedback_type	feedback_type,
		const uint8_t *const	packet,
		const size_t	packet_len,
		const uint8_t *const	feedback_data,
		const size_t	feedback_data_len
	)

Update the profile when feedback is received.

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

Parameters

context	The compression context
feedback_type	The feedback type
packet	The whole feedback packet with CID bits
packet_len	The length of the whole feedback packet with CID bits
feedback_data	The feedback data without the CID bits
feedback_data_len	The length of the feedback data without the CID bits

Returns: true if the feedback was successfully handled, false if the feedback could not be taken into account

bool rohc_comp_rfc3095_is_sn_possible	(	const struct rohc_comp_rfc3095_ctxt *const	rfc3095_ctxt,
		const size_t	bits_nr,
		const size_t	add_bits_nr
	)

Are the given SN field sizes possible?

Parameters

rfc3095_ctxt	The compression context
bits_nr	The base number of SN bits
add_bits_nr	The additional number of SN bits

Returns: true if the SN field is usable, false if not

void rohc_get_ipid_bits	(	const struct rohc_comp_ctxt *const	context,
		size_t *const	nr_innermost_bits,
		size_t *const	nr_outermost_bits
	)

Get the number of non-random outer/inner IP-ID bits.

Parameters

context	The compression context
nr_innermost_bits	OUT: the maximum number of IP-ID bits for the innermost IPv4 header
nr_outermost_bits	OUT: the maximum number of IP-ID bits for the outermost IP header

Data Structures

Functions

Detailed Description

Function Documentation