rohc_decomp.c File Reference

ROHC decompression routines. More...

#include "rohc_decomp.h"
#include "rohc_decomp_internals.h"
#include "rohc_traces_internal.h"
#include "rohc_time_internal.h"
#include "rohc_utils.h"
#include "rohc_bit_ops.h"
#include "rohc_debug.h"
#include "feedback_create.h"
#include "feedback_parse.h"
#include "sdvl.h"
#include "rohc_add_cid.h"
#include "rohc_decomp_detect_packet.h"
#include "crc.h"
#include "config.h"
#include <string.h>
#include <stdio.h>
#include <stdarg.h>
#include <assert.h>

Include dependency graph for rohc_decomp.c:

Data Structures
struct	d_decode_data
	Decompression-related data. More...
Functions
static bool	rohc_decomp_create_contexts (struct rohc_decomp *const decomp, const rohc_cid_t max_cid)
	Create the array of decompression contexts.
static rohc_status_t	d_decode_header (struct rohc_decomp *decomp, const struct rohc_buf rohc_packet, struct rohc_buf *const uncomp_packet, struct rohc_buf *const rcvd_feedback, struct d_decode_data *ddata, rohc_packet_t *const packet_type)
	Decompress the compressed headers.
static struct rohc_decomp_profile *	find_profile (const struct rohc_decomp *const decomp, const rohc_profile_t profile_id)
	Find the ROHC profile with the given profile ID.
static struct rohc_decomp_ctxt *	context_create (struct rohc_decomp *decomp, const rohc_cid_t cid, const struct rohc_decomp_profile *const profile, const struct rohc_ts arrival_time)
	Create one new decompression context with profile specific data.
static struct rohc_decomp_ctxt *	find_context (const struct rohc_decomp *const decomp, const rohc_cid_t cid)
	Find one decompression context thanks to its CID.
static void	context_free (struct rohc_decomp_ctxt *const context)
	Destroy one decompression context and the profile specific data associated with it.
static bool	rohc_decomp_decode_cid (struct rohc_decomp *decomp, const unsigned char *packet, unsigned int len, struct d_decode_data *ddata)
	Decode the CID of a packet.
static void	rohc_decomp_print_trace_default (const rohc_trace_level_t level, const rohc_trace_entity_t entity, const int profile, const char *const format,...)
	The default callback for traces.
static bool	__rohc_decomp_set_cid_type (struct rohc_decomp *const decomp, const rohc_cid_type_t cid_type)
	Set the type of CID to use for the given decompressor.
static bool	__rohc_decomp_set_max_cid (struct rohc_decomp *const decomp, const size_t max_cid)
	Set the MAX_CID allowed for the given decompressor.
static void	rohc_decomp_parse_padding (const struct rohc_decomp *const decomp, struct rohc_buf *const packet)
	Parse padding bits if some are present.
static bool	rohc_decomp_parse_feedbacks (struct rohc_decomp *const decomp, struct rohc_buf *const rohc_data, struct rohc_buf *const feedbacks)
	Parse zero or more feedback items from the given ROHC data.
static bool	rohc_decomp_parse_feedback (struct rohc_decomp *const decomp, struct rohc_buf *const rohc_data, struct rohc_buf *const feedback)
	Parse a feedback item from the given ROHC data.
static void	d_operation_mode_feedback (struct rohc_decomp *decomp, const rohc_status_t rohc_status, const uint16_t cid, const rohc_cid_type_t cid_type, int mode, struct rohc_decomp_ctxt *context, struct rohc_buf *const feedback_send)
	Send feedback depending on the mode: Unidirectional, Optimistic or Reliable.
static void	d_optimistic_feedback (struct rohc_decomp *decomp, const rohc_status_t rohc_status, const rohc_cid_t cid, const rohc_cid_type_t cid_type, struct rohc_decomp_ctxt *context, struct rohc_buf *const feedback_send)
	Send feedback in Optimistic Mode.
static void	rohc_decomp_reset_stats (struct rohc_decomp *const decomp)
	Reset all the statistics of the given ROHC decompressor.
static int	rohc_d_context (struct rohc_decomp *decomp, const size_t pos, unsigned int indent, char *buffer)
	Output the statistics of one decompression context to a buffer.
struct rohc_decomp *	rohc_alloc_decompressor (struct rohc_comp *compressor)
	Create one ROHC decompressor.
void	rohc_free_decompressor (struct rohc_decomp *decomp)
	Destroy one ROHC decompressor.
struct rohc_decomp *	rohc_decomp_new (const rohc_cid_type_t cid_type, const rohc_cid_t max_cid, const rohc_mode_t mode, struct rohc_comp *const comp)
	Create a new ROHC decompressor.
struct rohc_decomp *	rohc_decomp_new2 (const rohc_cid_type_t cid_type, const rohc_cid_t max_cid, const rohc_mode_t mode)
	Create a new ROHC decompressor.
void	rohc_decomp_free (struct rohc_decomp *const decomp)
	Destroy the given ROHC decompressor.
int	rohc_decompress (struct rohc_decomp *decomp, unsigned char *ibuf, int isize, unsigned char *obuf, int osize)
	Decompress the given ROHC packet into one uncompressed packet.
int	rohc_decompress2 (struct rohc_decomp *const decomp, const struct rohc_ts arrival_time, const unsigned char *const rohc_packet, const size_t rohc_packet_len, unsigned char *const uncomp_packet, const size_t uncomp_packet_max_len, size_t *const uncomp_packet_len)
	Decompress the given ROHC packet into one uncompressed packet.
rohc_status_t	rohc_decompress3 (struct rohc_decomp *const decomp, const struct rohc_buf rohc_packet, struct rohc_buf *const uncomp_packet, struct rohc_buf *const rcvd_feedback, struct rohc_buf *const feedback_send)
	Decompress the given ROHC packet into one uncompressed packet.
int	rohc_decompress_both (struct rohc_decomp *decomp, unsigned char *ibuf, int isize, unsigned char *obuf, int osize, int large)
	Decompress both large and small CID packets.
void	clear_statistics (struct rohc_decomp *decomp)
	Clear all the statistics.
int	rohc_d_statistics (struct rohc_decomp *decomp, unsigned int indent, char *buffer)
	Output the decompression statistics of one decompressor to a buffer. The buffer must be large enough to store all the statistics.
const char *	rohc_decomp_get_state_descr (const rohc_decomp_state_t state)
	Give a description for the given ROHC decompression context state.
bool	rohc_decomp_get_last_packet_info (const struct rohc_decomp *const decomp, rohc_decomp_last_packet_info_t *const info)
	Get some information about the last decompressed packet.
bool	rohc_decomp_get_general_info (const struct rohc_decomp *const decomp, rohc_decomp_general_info_t *const info)
	Get some general information about the decompressor.
void	user_interactions (struct rohc_decomp *decomp, int feedback_maxval)
	Update feedback interval by the user.
bool	rohc_decomp_set_cid_type (struct rohc_decomp *const decomp, const rohc_cid_type_t cid_type)
	Set the type of CID to use for the given decompressor.
bool	rohc_decomp_get_cid_type (const struct rohc_decomp *const decomp, rohc_cid_type_t *const cid_type)
	Get the CID type that the decompressor uses.
bool	rohc_decomp_set_max_cid (struct rohc_decomp *const decomp, const size_t max_cid)
	Set the MAX_CID allowed for the given decompressor.
bool	rohc_decomp_get_max_cid (const struct rohc_decomp *const decomp, size_t *const max_cid)
	Get the maximal CID value the decompressor uses.
bool	rohc_decomp_set_mrru (struct rohc_decomp *const decomp, const size_t mrru)
	Set the Maximum Reconstructed Reception Unit (MRRU).
bool	rohc_decomp_get_mrru (const struct rohc_decomp *const decomp, size_t *const mrru)
	Get the Maximum Reconstructed Reception Unit (MRRU).
bool	rohc_decomp_set_features (struct rohc_decomp *const decomp, const rohc_decomp_features_t features)
	Enable/disable features for ROHC decompressor.
bool	rohc_decomp_profile_enabled (const struct rohc_decomp *const decomp, const rohc_profile_t profile)
	Is the given decompression profile enabled for a decompressor?
bool	rohc_decomp_enable_profile (struct rohc_decomp *const decomp, const rohc_profile_t profile)
	Enable a decompression profile for a decompressor.
bool	rohc_decomp_disable_profile (struct rohc_decomp *const decomp, const rohc_profile_t profile)
	Disable a decompression profile for a decompressor.
bool	rohc_decomp_enable_profiles (struct rohc_decomp *const decomp,...)
	Enable several decompression profiles for a decompressor.
bool	rohc_decomp_disable_profiles (struct rohc_decomp *const decomp,...)
	Disable several decompression profiles for a decompressor.
bool	rohc_decomp_set_traces_cb (struct rohc_decomp *decomp, rohc_trace_callback_t callback)
	Set the callback function used to manage traces in decompressor.
bool	rohc_decomp_set_traces_cb2 (struct rohc_decomp *decomp, rohc_trace_callback2_t callback, void *const priv_ctxt)
	Set the callback function used to manage traces in decompressor.
Variables
struct rohc_decomp_profile d_uncomp_profile d_udp_profile d_ip_profile d_udplite_profile d_esp_profile d_rtp_profile	d_tcp_profile
	Define the decompression part of the TCP profile as described in the RFC 3095.
static struct rohc_decomp_profile *const	rohc_decomp_profiles [D_NUM_PROFILES]
	The decompression parts of the ROHC profiles.

---

Detailed Description

ROHC decompression routines.

Author:

Didier Barvaux <didier.barvaux@toulouse.viveris.com>

Didier Barvaux <didier@barvaux.org>

David Moreau from TAS

---

Function Documentation

static bool __rohc_decomp_set_cid_type	(	struct rohc_decomp *const	decomp,
		const rohc_cid_type_t	cid_type
	)		[static]

Set the type of CID to use for the given decompressor.

Set the type of CID to use for the given decompressor.

Warning:

Changing the CID type while library is used may lead to destruction of decompression contexts

Parameters:

decomp	The decompressor for which to set CID type
cid_type	The new CID type among ROHC_SMALL_CID or ROHC_LARGE_CID

Returns:

true if the CID type was successfully set, false otherwise

static bool __rohc_decomp_set_max_cid	(	struct rohc_decomp *const	decomp,
		const size_t	max_cid
	)		[static]

Set the MAX_CID allowed for the given decompressor.

Set the MAX_CID allowed for the given decompressor.

Warning:

Changing the MAX_CID value while library is used may lead to destruction of decompression contexts

Parameters:

decomp	The decompressor for which to set MAX_CID
max_cid	The new MAX_CID value: in range [0, ROHC_SMALL_CID_MAX] if CID type is ROHC_SMALL_CID in range [0, ROHC_LARGE_CID_MAX] if CID type is ROHC_LARGE_CID

Returns:

true if the MAX_CID was successfully set, false otherwise

static struct rohc_decomp_ctxt * context_create	(	struct rohc_decomp *	decomp,
		const rohc_cid_t	cid,
		const struct rohc_decomp_profile *const	profile,
		const struct rohc_ts	arrival_time
	)		[static, read]

Create one new decompression context with profile specific data.

Parameters:

decomp	The ROHC decompressor
cid	The CID of the new context
profile	The profile to be assigned with the new context
arrival_time	The time at which packet was received (0 if unknown, or to disable time-related features in ROHC protocol)

Returns:

The new context if successful, NULL otherwise

static void context_free

(

struct rohc_decomp_ctxt *const

context

)

[static]

Destroy one decompression context and the profile specific data associated with it.

Parameters:

context

The context to destroy

static rohc_status_t d_decode_header	(	struct rohc_decomp *	decomp,
		const struct rohc_buf	rohc_packet,
		struct rohc_buf *const	uncomp_packet,
		struct rohc_buf *const	rcvd_feedback,
		struct d_decode_data *	ddata,
		rohc_packet_t *const	packet_type
	)		[static]

Decompress the compressed headers.

Parameters:

	decomp	The ROHC decompressor
	rohc_packet	The ROHC packet to decode
[out]	uncomp_packet	The uncompressed packet
[out]	rcvd_feedback	The feedback received from the remote peer for the same-side associated ROHC compressor through the feedback channel: If NULL, ignore the received feedback data If not NULL, store the received feedback in at the given address
[out]	ddata	Decompression-related data (e.g. the context)
[out]	packet_type	The type of the decompressed ROHC packet

Returns:

Possible return values:

• ROHC_STATUS_OK if packet is successfully decoded,
• ROHC_STATUS_NO_CONTEXT if no matching context was found and packet cannot create a new context,
• ROHC_STATUS_MALFORMED if packet is malformed,
• ROHC_STATUS_BAD_CRC if a CRC error occurs,
• ROHC_STATUS_ERROR if another error occurs

static void d_operation_mode_feedback	(	struct rohc_decomp *	decomp,
		const rohc_status_t	rohc_status,
		const uint16_t	cid,
		const rohc_cid_type_t	cid_type,
		int	mode,
		struct rohc_decomp_ctxt *	context,
		struct rohc_buf *const	feedback_send
	)		[static]

Send feedback depending on the mode: Unidirectional, Optimistic or Reliable.

Parameters:

	decomp	The ROHC decompressor
	rohc_status	The type of feedback to send: ROHC_STATUS_OK = OK (ack), ROHC_STATUS_NO_CONTEXT = ContextInvalid (S-nack), ROHC_STATUS_MALFORMED = PackageFailed (Nack)
	cid	The Context ID (CID) to which the feedback is related
	cid_type	The type of CID used for the feedback
	mode	The mode in which the ROHC decompressor operates: ROHC_U_MODE, ROHC_O_MODE or ROHC_R_MODE
	context	The context to which the feedback is related
[out]	feedback_send	The feedback to be transmitted to the remote compressor through the feedback channel: If NULL, the decompression won't generate feedback information for its compressor If not NULL, may store the generated feedback at the given address

static void d_optimistic_feedback	(	struct rohc_decomp *	decomp,
		const rohc_status_t	rohc_status,
		const rohc_cid_t	cid,
		const rohc_cid_type_t	cid_type,
		struct rohc_decomp_ctxt *	context,
		struct rohc_buf *const	feedback_send
	)		[static]

Send feedback in Optimistic Mode.

Parameters:

	decomp	The ROHC decompressor
	rohc_status	The type of feedback to send: ROHC_STATUS_OK = OK (ack), ROHC_STATUS_NO_CONTEXT = ContextInvalid (S-nack), ROHC_STATUS_MALFORMED = PackageFailed (Nack)
	cid	The Context ID (CID) to which the feedback is related
	cid_type	The type of CID used for the feedback
	context	The context to which the feedback is related
[out]	feedback_send	The feedback to be transmitted to the remote compressor through the feedback channel: If NULL, the decompression won't generate feedback information for its compressor If not NULL, may store the generated feedback at the given address

static struct rohc_decomp_ctxt * find_context	(	const struct rohc_decomp *const	decomp,
		const rohc_cid_t	cid
	)		[static, read]

Find one decompression context thanks to its CID.

Parameters:

decomp	The ROHC decompressor
cid	The CID of the context to find out

Returns:

The context if found, NULL otherwise

static struct rohc_decomp_profile * find_profile	(	const struct rohc_decomp *const	decomp,
		const rohc_profile_t	profile_id
	)		[static, read]

Find the ROHC profile with the given profile ID.

Parameters:

decomp	The ROHC decompressor
profile_id	The profile ID to search for

Returns:

The matching ROHC profile if found and enabled, NULL if not found or disabled

static int rohc_d_context	(	struct rohc_decomp *	decomp,
		const size_t	pos,
		unsigned int	indent,
		char *	buffer
	)		[static]

Output the statistics of one decompression context to a buffer.

The buffer must be large enough to store the statistics of one context.

Parameters:

decomp	The ROHC decompressor
pos	The pos of the decompression context in the contexts array
indent	The level of indentation to add during output
buffer	The buffer where to outputs the statistics

Returns:

The length of data written to the buffer

static bool rohc_decomp_create_contexts	(	struct rohc_decomp *const	decomp,
		const rohc_cid_t	max_cid
	)		[static]

Create the array of decompression contexts.

The maximum size of the array is ROHC_LARGE_CID_MAX + 1.

Parameters:

decomp	The ROHC decompressor
max_cid	The MAX_CID value to used (may be different from the one in decompressor if the MAX_CID value is being changed)

Returns:

true if the contexts were created, false otherwise

static bool rohc_decomp_decode_cid	(	struct rohc_decomp *	decomp,
		const unsigned char *	packet,
		unsigned int	len,
		struct d_decode_data *	ddata
	)		[static]

Decode the CID of a packet.

Parameters:

decomp	The ROHC decompressor
packet	The ROHC packet to extract CID from
len	The size of the ROHC packet
ddata	IN/OUT: decompression-related data (e.g. the context)

Returns:

true in case of success, false in case of failure

static bool rohc_decomp_parse_feedback	(	struct rohc_decomp *const	decomp,
		struct rohc_buf *const	rohc_data,
		struct rohc_buf *const	feedback
	)		[static]

Parse a feedback item from the given ROHC data.

Parameters:

	decomp	The ROHC decompressor
	rohc_data	The ROHC data to parse for one feedback item
[out]	feedback	The retrieved feedback (header and data included), may be NULL if one don't want to retrieve the feedback item

Returns:

true if feedback parsing was successful, false if feedback is malformed

static bool rohc_decomp_parse_feedbacks	(	struct rohc_decomp *const	decomp,
		struct rohc_buf *const	rohc_data,
		struct rohc_buf *const	feedbacks
	)		[static]

Parse zero or more feedback items from the given ROHC data.

Parameters:

	decomp	The ROHC decompressor
	rohc_data	The ROHC data to parse for feedback items
[out]	feedbacks	The parsed feedback items, may be NULL if one don't want to retrieve the feedback items

Returns:

true if parsing of feedback items is successful, false if at least one feedback is malformed

static void rohc_decomp_parse_padding	(	const struct rohc_decomp *const	decomp,
		struct rohc_buf *const	packet
	)		[static]

Parse padding bits if some are present.

Parameters:

decomp	The ROHC decompressor
packet	The ROHC packet to parse

static void rohc_decomp_print_trace_default	(	const rohc_trace_level_t	level,
		const rohc_trace_entity_t	entity,
		const int	profile,
		const char *const	format,
			...
	)		[static]

The default callback for traces.

The default callback for traces always prints traces on stdout for compatibility with previous releases. That could be changed for the 2.0.0 release.

Parameters:

level	The level of the message
entity	The entity concerned by the traces
profile	The number of the profile concerned by the message
format	The format string for the trace message
...	The arguments related to the format string

static void rohc_decomp_reset_stats

(

struct rohc_decomp *const

decomp

)

[static]

Reset all the statistics of the given ROHC decompressor.

Parameters:

decomp

The ROHC decompressor

---

Variable Documentation

struct rohc_decomp_profile d_uncomp_profile d_udp_profile d_ip_profile d_udplite_profile d_esp_profile d_rtp_profile d_tcp_profile

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

struct rohc_decomp_profile* const rohc_decomp_profiles[D_NUM_PROFILES] [static]

Initial value:

{
        &d_uncomp_profile,
        &d_rtp_profile,
        &d_udp_profile,
        &d_esp_profile,
        &d_ip_profile,
        &d_tcp_profile,
        &d_udplite_profile,
}

The decompression parts of the ROHC profiles.