rohc_comp.c File Reference

ROHC compression routines. More...

#include "rohc_comp.h"
#include "rohc_comp_internals.h"
#include "rohc_packets.h"
#include "rohc_traces.h"
#include "rohc_traces_internal.h"
#include "rohc_time_internal.h"
#include "rohc_debug.h"
#include "rohc_utils.h"
#include "sdvl.h"
#include "rohc_add_cid.h"
#include "rohc_bit_ops.h"
#include "ip.h"
#include "crc.h"
#include "protocols/udp.h"
#include "protocols/ip_numbers.h"
#include "feedback_parse.h"
#include "config.h"
#include <string.h>
#include <inttypes.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
#include <stdarg.h>

Include dependency graph for rohc_comp.c:

Functions
static const struct rohc_comp_profile *	rohc_get_profile_from_id (const struct rohc_comp *comp, const rohc_profile_t profile_id)
	Find out a ROHC profile given a profile ID. More...
static const struct rohc_comp_profile *	c_get_profile_from_packet (const struct rohc_comp *const comp, const struct net_pkt *const packet)
	Find out a ROHC profile given an IP protocol ID. More...
static bool	c_create_contexts (struct rohc_comp *const comp)
	Create the array of compression contexts. More...
static void	c_destroy_contexts (struct rohc_comp *const comp)
	Destroy all the compression contexts in the context array. More...
static struct rohc_comp_ctxt *	c_create_context (struct rohc_comp *const comp, const struct rohc_comp_profile *const profile, const struct net_pkt *const packet, const struct rohc_ts arrival_time, const bool do_ctxt_replication, const rohc_cid_t cid_for_replication)
	Create a compression context. More...
static struct rohc_comp_ctxt *	rohc_comp_find_ctxt (struct rohc_comp *const comp, const struct net_pkt *const packet, const int profile_id_hint, const struct rohc_ts arrival_time)
	Find a compression context given an IP packet. More...
static struct rohc_comp_ctxt *	c_get_context (struct rohc_comp *const comp, const rohc_cid_t cid)
	Find out a context given its CID. More...
static bool	__rohc_comp_deliver_feedback (struct rohc_comp *const comp, const uint8_t *const packet, const size_t size)
	Deliver a feedback packet to the compressor. More...
static bool	rohc_comp_feedback_parse_cid (const struct rohc_comp *const comp, const uint8_t *const feedback, const size_t feedback_len, rohc_cid_t *const cid, size_t *const cid_len)
	Parse ROHC feedback CID. More...
static bool	rohc_comp_feedback_parse_opt_sn (const struct rohc_comp_ctxt *const context, const uint8_t *const feedback_data, const size_t feedback_data_len, uint32_t *const sn_bits, size_t *const sn_bits_nr)
	Parse the FEEDBACK-2 SN option. More...
static bool	rohc_comp_feedback_check_opts (const struct rohc_comp_ctxt *const context, const size_t opts_present[ROHC_FEEDBACK_OPT_MAX])
	Check FEEDBACK-2 options. More...
struct rohc_comp *	rohc_comp_new2 (const rohc_cid_type_t cid_type, const rohc_cid_t max_cid, const rohc_comp_random_cb_t rand_cb, void *const rand_priv)
	Create a new ROHC compressor. More...
void	rohc_comp_free (struct rohc_comp *const comp)
	Destroy the given ROHC compressor. More...
bool	rohc_comp_set_traces_cb2 (struct rohc_comp *const comp, rohc_trace_callback2_t callback, void *const priv_ctxt)
	Set the callback function used to manage traces in compressor. More...
rohc_status_t	rohc_compress4 (struct rohc_comp *const comp, const struct rohc_buf uncomp_packet, struct rohc_buf *const rohc_packet)
	Compress the given uncompressed packet into a ROHC packet. More...
rohc_status_t	rohc_comp_pad (struct rohc_comp *const comp, struct rohc_buf *const rohc_pkt, const size_t min_pkt_len)
	Pad the given ROHC compressed packet. More...
rohc_status_t	rohc_comp_get_segment2 (struct rohc_comp *const comp, struct rohc_buf *const segment)
	Get the next ROHC segment if any. More...
bool	rohc_comp_force_contexts_reinit (struct rohc_comp *const comp)
	Force the compressor to re-initialize all its contexts. More...
bool	rohc_comp_set_wlsb_window_width (struct rohc_comp *const comp, const size_t width)
	Set the window width for the W-LSB encoding scheme. More...
bool	rohc_comp_set_periodic_refreshes (struct rohc_comp *const comp, const size_t ir_timeout, const size_t fo_timeout)
	Set the timeouts in packets for IR and FO periodic refreshes. More...
bool	rohc_comp_set_periodic_refreshes_time (struct rohc_comp *const comp, const uint64_t ir_timeout, const uint64_t fo_timeout)
	Set the timeouts in ms for IR and FO periodic refreshes. More...
bool	rohc_comp_set_list_trans_nr (struct rohc_comp *const comp, const size_t list_trans_nr)
	Set the number of uncompressed transmissions for list compression. More...
bool	rohc_comp_set_rtp_detection_cb (struct rohc_comp *const comp, rohc_rtp_detection_callback_t callback, void *const rtp_private)
	Set the RTP detection callback function. More...
bool	rohc_comp_profile_enabled (const struct rohc_comp *const comp, const rohc_profile_t profile)
	Is the given compression profile enabled for a compressor? More...
bool	rohc_comp_enable_profile (struct rohc_comp *const comp, const rohc_profile_t profile)
	Enable a compression profile for a compressor. More...
bool	rohc_comp_disable_profile (struct rohc_comp *const comp, const rohc_profile_t profile)
	Disable a compression profile for a compressor. More...
bool	rohc_comp_enable_profiles (struct rohc_comp *const comp,...)
	Enable several compression profiles for a compressor. More...
bool	rohc_comp_disable_profiles (struct rohc_comp *const comp,...)
	Disable several compression profiles for a compressor. More...
bool	rohc_comp_set_mrru (struct rohc_comp *const comp, const size_t mrru)
	Set the Maximum Reconstructed Reception Unit (MRRU). More...
bool	rohc_comp_get_mrru (const struct rohc_comp *const comp, size_t *const mrru)
	Get the Maximum Reconstructed Reception Unit (MRRU). More...
bool	rohc_comp_get_max_cid (const struct rohc_comp *const comp, size_t *const max_cid)
	Get the maximal CID value the compressor uses. More...
bool	rohc_comp_get_cid_type (const struct rohc_comp *const comp, rohc_cid_type_t *const cid_type)
	Get the CID type that the compressor uses. More...
bool	rohc_comp_set_features (struct rohc_comp *const comp, const rohc_comp_features_t features)
	Enable/disable features for ROHC compressor. More...
bool	rohc_comp_deliver_feedback2 (struct rohc_comp *const comp, const struct rohc_buf feedback)
	Deliver a feedback packet to the compressor. More...
bool	rohc_comp_get_last_packet_info2 (const struct rohc_comp *const comp, rohc_comp_last_packet_info2_t *const info)
	Get some information about the last compressed packet. More...
bool	rohc_comp_get_general_info (const struct rohc_comp *const comp, rohc_comp_general_info_t *const info)
	Get some general information about the compressor. More...
const char *	rohc_comp_get_state_descr (const rohc_comp_state_t state)
	Give a description for the given ROHC compression context state. More...
void	rohc_comp_change_mode (struct rohc_comp_ctxt *const context, const rohc_mode_t new_mode)
	Change the mode of the context. More...
void	rohc_comp_change_state (struct rohc_comp_ctxt *const context, const rohc_comp_state_t new_state)
	Change the state of the context. More...
void	rohc_comp_periodic_down_transition (struct rohc_comp_ctxt *const context, const struct rohc_ts pkt_time)
	Periodically change the context state after a certain number of packets. More...
bool	rohc_comp_reinit_context (struct rohc_comp_ctxt *const context)
	Re-initialize the given context. More...
bool	rohc_comp_feedback_parse_opts (const struct rohc_comp_ctxt *const context, const uint8_t *const packet, const size_t packet_len, const uint8_t *const feedback_data, const size_t feedback_data_len, size_t opts_present[ROHC_FEEDBACK_OPT_MAX], uint32_t *const sn_bits, size_t *const sn_bits_nr, uint8_t crc_in_packet, size_t crc_pos_from_end)
	Parse FEEDBACK-2 options. More...

Variables
const struct rohc_comp_profile	c_rtp_profile
	Define the compression part of the RTP profile as described in the RFC 3095. More...
const struct rohc_comp_profile	c_udp_profile
	Define the compression part of the UDP profile as described in the RFC 3095. More...
const struct rohc_comp_profile	c_udp_lite_profile
	Define the compression part of the UDP-Lite profile as described in the RFC 4019. More...
const struct rohc_comp_profile	c_esp_profile
	Define the compression part of the ESP profile as described in the RFC 3095. More...
const struct rohc_comp_profile	c_tcp_profile
	Define the compression part of the TCP profile as described in the RFC 3095. More...
const struct rohc_comp_profile	c_ip_profile
	Define the compression part of the IP-only profile as described in the RFC 3843. More...
const struct rohc_comp_profile	c_uncompressed_profile
	Define the compression part of the Uncompressed profile as described in the RFC 3095. More...
static const struct rohc_comp_profile *const	rohc_comp_profiles [C_NUM_PROFILES]
	The compression parts of the ROHC profiles. More...

Detailed Description

ROHC compression routines.

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

David Moreau from TAS

Function Documentation

__rohc_comp_deliver_feedback()

static bool __rohc_comp_deliver_feedback ( struct rohc_comp *const  comp, const uint8_t *const  packet, const size_t  size  )

static

Deliver a feedback packet to the compressor.

When feedback is received by the decompressor, this function is called and delivers the feedback to the right profile/context of the compressor.

Parameters

comp	The ROHC compressor
packet	The feedback data
size	The length of the feedback packet

Returns

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

c_create_context()

static struct rohc_comp_ctxt * c_create_context ( struct rohc_comp *const  comp, const struct rohc_comp_profile *const  profile, const struct net_pkt *const  packet, const struct rohc_ts  arrival_time, const bool  do_ctxt_replication, const rohc_cid_t  cid_for_replication  )

static

Create a compression context.

Parameters

comp	The ROHC compressor
profile	The profile to associate the context with
packet	The packet to create a compression context for
arrival_time	The time at which packet was received (0 if unknown, or to disable time-related features in ROHC protocol)
do_ctxt_replication	Are we able to replicate an existing context?
cid_for_replication	The context to replicate if any

Returns

The compression context if successful, NULL otherwise

c_create_contexts()

static bool c_create_contexts ( struct rohc_comp *const  comp )

static

Create the array of compression contexts.

Parameters

comp	The ROHC compressor

Returns

true if the creation is successful, false otherwise

c_destroy_contexts()

static void c_destroy_contexts ( struct rohc_comp *const  comp )

static

Destroy all the compression contexts in the context array.

The profile-specific contexts are also destroyed.

Parameters

comp	The ROHC compressor

c_get_context()

static struct rohc_comp_ctxt * c_get_context ( struct rohc_comp *const  comp, const rohc_cid_t  cid  )

static

Find out a context given its CID.

Parameters

comp	The ROHC compressor
cid	The CID of the context to find

Returns

The context with the given CID if found, NULL otherwise

c_get_profile_from_packet()

static const struct rohc_comp_profile * c_get_profile_from_packet ( const struct rohc_comp *const  comp, const struct net_pkt *const  packet  )

static

Find out a ROHC profile given an IP protocol ID.

Parameters

comp	The ROHC compressor
packet	The packet to find a compression profile for

Returns

The ROHC profile if found, NULL otherwise

rohc_comp_change_mode()

void rohc_comp_change_mode	(	struct rohc_comp_ctxt *const	context,
		const rohc_mode_t	new_mode
	)

Change the mode of the context.

Parameters

context	The compression context
new_mode	The new mode the context must enter in

rohc_comp_change_state()

void rohc_comp_change_state	(	struct rohc_comp_ctxt *const	context,
		const rohc_comp_state_t	new_state
	)

Change the state of the context.

Parameters

context	The compression context
new_state	The new state the context must enter in

rohc_comp_feedback_check_opts()

static bool rohc_comp_feedback_check_opts ( const struct rohc_comp_ctxt *const  context, const size_t  opts_present[ROHC_FEEDBACK_OPT_MAX]  )

static

Check FEEDBACK-2 options.

sanity checks:

• some profiles do not support all options
• some options cannot be specified multiple times
• some options cannot be specified without CRC

Parameters

context	The ROHC decompression context
opts_present	Whether options are present or not

Returns

true if feedback options are valid, false if feedback options are not valid

rohc_comp_feedback_parse_cid()

static bool rohc_comp_feedback_parse_cid ( const struct rohc_comp *const  comp, const uint8_t *const  feedback, const size_t  feedback_len, rohc_cid_t *const  cid, size_t *const  cid_len  )

static

Parse ROHC feedback CID.

Parameters

	comp	The ROHC compressor
	feedback	The ROHC feedback data to parse
	feedback_len	The length of the ROHC feedback data
[out]	cid	The CID of the ROHC feedback
[out]	cid_len	The length of the CID of the ROHC feedback

Returns

true if feedback CID was successfully parsed, false if feedback CID is malformed

rohc_comp_feedback_parse_opt_sn()

static bool rohc_comp_feedback_parse_opt_sn ( const struct rohc_comp_ctxt *const  context, const uint8_t *const  feedback_data, const size_t  feedback_data_len, uint32_t *const  sn_bits, size_t *const  sn_bits_nr  )

static

Parse the FEEDBACK-2 SN option.

Parameters

	context	The ROHC decompression context
	feedback_data	The feedback data without the CID bits
	feedback_data_len	The length of the feedback data without the CID bits
[out]	sn_bits	in: the SN bits collected in base header out: the SN bits collected in base header and options
[out]	sn_bits_nr	in: the number of SN bits collected in base header out: the number of SN bits collected in base header and options

Returns

true if feedback options were successfully parsed, false if feedback options were malformed or CRC is wrong

rohc_comp_feedback_parse_opts()

bool rohc_comp_feedback_parse_opts	(	const struct rohc_comp_ctxt *const	context,
		const uint8_t *const	packet,
		const size_t	packet_len,
		const uint8_t *const	feedback_data,
		const size_t	feedback_data_len,
		size_t	opts_present[ROHC_FEEDBACK_OPT_MAX],
		uint32_t *const	sn_bits,
		size_t *const	sn_bits_nr,
		uint8_t	crc_in_packet,
		size_t	crc_pos_from_end
	)

Parse FEEDBACK-2 options.

Parameters

	context	The ROHC decompression context
	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
[out]	opts_present	Whether options are present or not
[out]	sn_bits	in: the SN bits collected in base header out: the SN bits collected in base header and options
[out]	sn_bits_nr	in: the number of SN bits collected in base header out: the number of SN bits collected in base header and options
	crc_in_packet	The CRC of the feedback packet
	crc_pos_from_end	The position of the CRC byte from the end of the feedback packet

Returns

true if feedback options were successfully parsed, false if feedback options were malformed or CRC is wrong

rohc_comp_find_ctxt()

static struct rohc_comp_ctxt * rohc_comp_find_ctxt ( struct rohc_comp *const  comp, const struct net_pkt *const  packet, const int  profile_id_hint, const struct rohc_ts  arrival_time  )

static

Find a compression context given an IP packet.

Parameters

comp	The ROHC compressor
packet	The packet to find a compression context for
profile_id_hint	If positive, indicate the profile to use
arrival_time	The time at which packet was received (0 if unknown, or to disable time-related features in the ROHC protocol)

Returns

The context if found or successfully created, NULL if not found

rohc_comp_periodic_down_transition()

void rohc_comp_periodic_down_transition	(	struct rohc_comp_ctxt *const	context,
		const struct rohc_ts	pkt_time
	)

Periodically change the context state after a certain number of packets.

Parameters

context	The compression context
pkt_time	The time of packet arrival

rohc_comp_reinit_context()

bool rohc_comp_reinit_context

(

struct rohc_comp_ctxt *const

context

)

Re-initialize the given context.

Make the context restart its initialization with decompressor, ie. it goes in the lowest compression state.

Parameters

context

The compression context to re-initialize

Returns

true in case of success, false otherwise

rohc_get_profile_from_id()

static const struct rohc_comp_profile * rohc_get_profile_from_id ( const struct rohc_comp *  comp, const rohc_profile_t  profile_id  )

static

Find out a ROHC profile given a profile ID.

Parameters

comp	The ROHC compressor
profile_id	The ID of the ROHC profile to find out

Returns

The ROHC profile if found, NULL otherwise

Variable Documentation

c_esp_profile

const struct rohc_comp_profile c_esp_profile

Define the compression part of the ESP profile as described in the RFC 3095.

c_ip_profile

const struct rohc_comp_profile c_ip_profile

Define the compression part of the IP-only profile as described in the RFC 3843.

c_rtp_profile

const struct rohc_comp_profile c_rtp_profile

Define the compression part of the RTP profile as described in the RFC 3095.

c_tcp_profile

const struct rohc_comp_profile c_tcp_profile

Define the compression part of the TCP profile as described in the RFC 3095.

c_udp_lite_profile

const struct rohc_comp_profile c_udp_lite_profile

Define the compression part of the UDP-Lite profile as described in the RFC 4019.

c_udp_profile

const struct rohc_comp_profile c_udp_profile

Define the compression part of the UDP profile as described in the RFC 3095.

c_uncompressed_profile

const struct rohc_comp_profile c_uncompressed_profile

Define the compression part of the Uncompressed profile as described in the RFC 3095.

rohc_comp_profiles

const struct rohc_comp_profile* const rohc_comp_profiles[C_NUM_PROFILES]

static

Initial value:

=
{
        &c_rtp_profile,
        &c_udp_profile,  
        &c_udp_lite_profile,
        &c_esp_profile,
        &c_tcp_profile,
        &c_ip_profile,  
        &c_uncompressed_profile, 
}

The compression parts of the ROHC profiles.

The order of profiles declaration is important: they are evaluated in that order. The RTP profile shall be declared before the UDP one for example.