rohc_comp.h File Reference

ROHC compression routines. More...

#include <netinet/ip.h>
#include <netinet/udp.h>
#include <string.h>
#include <stdbool.h>
#include "rohc.h"
#include <stdlib.h>
#include "cid.h"

Include dependency graph for rohc_comp.h:

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

Go to the source code of this file.

Classes
struct	rohc_feedback
	Information on ROHC feedback data. More...
struct	rohc_comp
	The ROHC compressor. More...
struct	c_context
	The ROHC compression context. More...
struct	c_profile
	The ROHC compression profile. More...
struct	c_feedback
	The feedback packet. More...
Defines
#define	C_NUM_PROFILES   5
	The number of ROHC profiles ready to be used.
#define	FEEDBACK_BUFFER_SIZE   10
	The maximal number of outgoing feedbacks that can be queued.
Enumerations
enum	rohc_c_state { IR = 1, FO = 2, SO = 3 }
	ROHC compressor states (see 4.3.1 in the RFC 3095) More...
Functions
struct rohc_comp *	rohc_alloc_compressor (int max_cid, int jam_use, int adapt_size, int encap_size)
	Create one ROHC compressor.
void	rohc_free_compressor (struct rohc_comp *comp)
	Destroy one ROHC compressor.
int	rohc_compress (struct rohc_comp *comp, unsigned char *ibuf, int isize, unsigned char *obuf, int osize)
	Compress a ROHC packet.
int	rohc_c_info (char *buffer)
	Get information about available compression profiles.
int	rohc_c_statistics (struct rohc_comp *comp, unsigned int indent, char *buffer)
	Get information about a ROHC compressor.
int	rohc_c_context (struct rohc_comp *comp, int cid, unsigned int indent, char *buffer)
	Get information about a compression context.
int	rohc_c_is_enabled (struct rohc_comp *comp)
	Whether the ROHC compressor is enabled or not.
int	rohc_c_using_small_cid (struct rohc_comp *comp)
	Whether the compressor uses small CID or not.
struct c_context *	c_create_context (struct rohc_comp *, struct c_profile *profile, struct ip_packet ip)
	Create a compression context.
struct c_context *	c_find_context (struct rohc_comp *, struct c_profile *profile, struct ip_packet ip)
	Find a compression context given a profile and an IP packet.
struct c_context *	c_get_context (struct rohc_comp *, int cid)
	Find out a context given its CID.
struct c_profile *	c_get_profile_from_packet (struct rohc_comp *comp, struct ip_packet *outer_ip, struct ip_packet *inner_ip, int protocol)
	Find out a ROHC profile given an IP protocol ID.
struct c_profile *	c_get_profile_from_id (struct rohc_comp *comp, int profile_id)
	Find out a ROHC profile given a profile ID.
void	rohc_activate_profile (struct rohc_comp *comp, int profile)
	Activate a profile for a compressor.
void	c_piggyback_feedback (struct rohc_comp *comp, unsigned char *packet, int size)
	Add a feedback packet to the next outgoing ROHC packet (piggybacking)
void	c_deliver_feedback (struct rohc_comp *comp, unsigned char *feedback, int size)
	Callback called by a decompressor to deliver a feedback packet to the compressor.
int	rohc_feedback_flush (struct rohc_comp *comp, unsigned char *obuf, int osize)
	Send as much feedback data as possible.
void	rohc_c_set_header (struct rohc_comp *compressor, int value)
	Set the maximal header size. The maximal header size is ignored for the moment.
void	rohc_c_set_mrru (struct rohc_comp *compressor, int value)
	Set the Maximum Reconstructed Reception Unit (MRRU). The MRRU is ignored for the moment.
void	rohc_c_set_max_cid (struct rohc_comp *compressor, int value)
	Set the maximal CID value the compressor should use.
void	rohc_c_set_large_cid (struct rohc_comp *compressor, int value)
	Tell the compressor to use large CIDs.
void	rohc_c_set_enable (struct rohc_comp *compressor, int value)
	Enable the ROHC compressor.

---

Detailed Description

ROHC compression routines.

Author:

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

The hackers from ROHC for Linux

---

Define Documentation

#define C_NUM_PROFILES   5

The number of ROHC profiles ready to be used.

Referenced by c_get_profile_from_id(), c_get_profile_from_packet(), rohc_activate_profile(), rohc_alloc_compressor(), rohc_c_info(), and rohc_c_statistics().

#define FEEDBACK_BUFFER_SIZE   10

The maximal number of outgoing feedbacks that can be queued.

Referenced by c_piggyback_feedback(), and rohc_alloc_compressor().

---

Enumeration Type Documentation

enum rohc_c_state

ROHC compressor states (see 4.3.1 in the RFC 3095)

Enumerator:

IR	The Initialization and Refresh state.
FO	The First Order state.
SO	The Second Order state.

---

Function Documentation

struct c_context* c_create_context	(	struct rohc_comp *	comp,
		struct c_profile *	profile,
		struct ip_packet	ip
	)		[read]

Create a compression context.

Parameters:

comp	The ROHC compressor
profile	The profile to associate the context with
ip	The IP packet to initialize the context

Returns:

The compression context if successful, NULL otherwise

References c_alloc_contexts(), c_context::cid, c_context::compressor, rohc_comp::contexts, c_profile::create, c_profile::destroy, c_context::first_used, c_context::header_compressed_size, c_context::header_last_compressed_size, c_context::header_last_uncompressed_size, c_context::header_uncompressed_size, IR, c_context::latest_used, c_context::mode, rohc_comp::num_contexts, rohc_comp::num_contexts_used, c_context::num_recv_feedbacks, c_context::num_sent_ir, c_context::num_sent_ir_dyn, c_context::num_sent_packets, c_context::profile, rohc_debugf, c_context::state, c_context::total_compressed_size, c_context::total_last_compressed_size, c_context::total_last_uncompressed_size, c_context::total_uncompressed_size, U_MODE, and c_context::used.

Referenced by rohc_compress().

void c_deliver_feedback	(	struct rohc_comp *	comp,
		unsigned char *	packet,
		int	size
	)

Callback called by a decompressor to 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

References c_feedback::acktype, c_get_context(), c_feedback::cid, medium::cid_type, d_decode_add_cid(), d_is_add_cid(), d_sdvalue_decode(), d_sdvalue_size(), c_feedback::data, c_profile::feedback, rohc_comp::medium, c_context::num_recv_feedbacks, c_context::profile, rohc_debugf, c_feedback::size, c_feedback::specific_offset, c_feedback::specific_size, c_feedback::type, and zfree.

struct c_context* c_find_context	(	struct rohc_comp *	comp,
		struct c_profile *	profile,
		struct ip_packet	ip
	)		[read]

Find a compression context given a profile and an IP packet.

Parameters:

comp	The ROHC compressor
profile	The profile the context must be associated with
ip	The IP packet that must be accepted by the context

Returns:

The compression context if found, NULL if not found, -1 if an error occurs

References c_profile::check_context, c_context::cid, rohc_comp::contexts, c_profile::id, rohc_comp::num_contexts, c_context::profile, rohc_debugf, and c_context::used.

Referenced by rohc_compress().

struct c_context* c_get_context	(	struct rohc_comp *	comp,
		int	cid
	)		[read]

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

References c_context::cid, rohc_comp::contexts, rohc_comp::num_contexts, and c_context::used.

Referenced by c_deliver_feedback().

struct c_profile* c_get_profile_from_id	(	struct rohc_comp *	comp,
		int	profile_id
	)		[read]

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

References C_NUM_PROFILES, and rohc_comp::profiles.

Referenced by rohc_compress().

struct c_profile* c_get_profile_from_packet	(	struct rohc_comp *	comp,
		struct ip_packet *	outer_ip,
		struct ip_packet *	inner_ip,
		int	protocol
	)		[read]

Find out a ROHC profile given an IP protocol ID.

Parameters:

comp	The ROHC compressor
outer_ip	The outer IP header of the network packet that will help choosing the best profile
inner_ip	The inner IP header of the network packet that will help choosing the best profile if any NULL if there is no inner IP header in the packet
protocol	The transport protocol of the network packet

Returns:

The ROHC profile if found, NULL otherwise

References c_is_in_list(), C_NUM_PROFILES, c_profile::description, ip_get_hdrlen(), ip_get_next_layer(), ip_get_plen(), ip_is_fragment(), IPV4, IPV6, rohc_comp::profiles, rohc_debugf, ROHC_PROFILE_RTP, ROHC_PROFILE_UNCOMPRESSED, and ip_packet::version.

Referenced by rohc_compress().

void c_piggyback_feedback	(	struct rohc_comp *	comp,
		unsigned char *	feedback,
		int	size
	)

Add a feedback packet to the next outgoing ROHC packet (piggybacking)

Parameters:

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

References rohc_feedback::data, FEEDBACK_BUFFER_SIZE, rohc_comp::feedbacks, rohc_comp::feedbacks_first, rohc_comp::feedbacks_next, rohc_feedback::length, and rohc_debugf.

Referenced by d_change_mode_feedback(), and d_optimistic_feedback().

int rohc_c_context	(	struct rohc_comp *	comp,
		int	cid,
		unsigned int	indent,
		char *	buffer
	)

Get information about a compression context.

This function outputs XML.

Parameters:

comp	The ROHC compressor
cid	The CID of the compressor context to output information about
indent	The indent level to beautify the XML output
buffer	The buffer where to store the information

Returns:

The length of the data stored in the buffer if successful, -2 if the given CID is too large, -1 if the given CID is unused or an error occurs

References c_mean_wlsb(), c_sum_wlsb(), c_context::cid, rohc_comp::contexts, c_profile::description, c_context::first_used, c_context::header_16_compressed, c_context::header_16_uncompressed, c_context::header_compressed_size, c_context::header_uncompressed_size, c_context::latest_used, c_context::mode, rohc_comp::num_contexts, c_context::num_recv_feedbacks, c_context::num_sent_ir, c_context::num_sent_ir_dyn, c_context::num_sent_packets, c_context::profile, c_context::state, c_context::total_16_compressed, c_context::total_16_uncompressed, c_context::total_compressed_size, c_context::total_uncompressed_size, and c_context::used.

Referenced by rohc_c_statistics().