d_esp.c File Reference

ROHC ESP decompression profile. More...

#include "rohc_decomp_rfc3095.h"
#include "d_ip.h"
#include "rohc_traces_internal.h"
#include "rohc_debug.h"
#include "rohc_utils.h"
#include "crc.h"
#include "protocols/esp.h"
#include "schemes/decomp_wlsb.h"
#include <stdint.h>
#include <string.h>
#include <assert.h>

Include dependency graph for d_esp.c:

Data Structures
struct	d_esp_context
	Define the ESP part of the decompression profile context. More...
Functions
static bool	d_esp_create (const struct rohc_decomp_ctxt *const context, struct rohc_decomp_rfc3095_ctxt **const persist_ctxt, struct rohc_decomp_volat_ctxt *const volat_ctxt)
	Create the ESP decompression context.
static void	d_esp_destroy (struct rohc_decomp_rfc3095_ctxt *const rfc3095_ctxt, const struct rohc_decomp_volat_ctxt *const volat_ctxt)
	Destroy the context.
static int	esp_parse_static_esp (const struct rohc_decomp_ctxt *const context, const uint8_t *packet, size_t length, struct rohc_extr_bits *const bits)
	Parse the ESP static part of the ROHC packet.
static int	esp_parse_dynamic_esp (const struct rohc_decomp_ctxt *const context, const uint8_t *packet, const size_t length, struct rohc_extr_bits *const bits)
	Parse the ESP dynamic part of the ROHC packet.
static bool	esp_decode_values_from_bits (const struct rohc_decomp_ctxt *context, const struct rohc_extr_bits *const bits, struct rohc_decoded_values *const decoded)
	Decode ESP values from extracted bits.
static int	esp_build_uncomp_esp (const struct rohc_decomp_ctxt *const context, const struct rohc_decoded_values *const decoded, uint8_t *const dest, const unsigned int payload_len)
	Build an uncompressed ESP header.
static void	esp_update_context (struct rohc_decomp_ctxt *const context, const struct rohc_decoded_values *const decoded)
	Update context with decoded ESP values.
Variables
struct rohc_decomp_profile	d_esp_profile
	Define the decompression part of the ESP profile as described in the RFC 3095.

---

Detailed Description

ROHC ESP decompression profile.

Author:

FWX <rohc_team@dialine.fr>

Didier Barvaux <didier@barvaux.org>

---

Function Documentation

static bool d_esp_create	(	const struct rohc_decomp_ctxt *const	context,
		struct rohc_decomp_rfc3095_ctxt **const	persist_ctxt,
		struct rohc_decomp_volat_ctxt *const	volat_ctxt
	)			[static]

Create the ESP decompression 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

Returns:

true if the ESP context was successfully created, false if a problem occurred

static void d_esp_destroy	(	struct rohc_decomp_rfc3095_ctxt *const	rfc3095_ctxt,
		const struct rohc_decomp_volat_ctxt *const	volat_ctxt
	)			[static]

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 persistent decompression context for the RFC3095 profiles
	volat_ctxt	The volatile decompression context

static int esp_build_uncomp_esp	(	const struct rohc_decomp_ctxt *const	context,
		const struct rohc_decoded_values *const	decoded,
		uint8_t *const	dest,
		const unsigned int	payload_len
	)			[static]

Build an uncompressed ESP header.

Parameters:

	context	The decompression context
	decoded	The values decoded from the ROHC header
	dest	The buffer to store the ESP header (MUST be at least of sizeof(struct esphdr) length)
	payload_len	The length of the ESP payload

Returns:

The length of the next header (ie. the ESP header), -1 in case of error

static bool esp_decode_values_from_bits	(	const struct rohc_decomp_ctxt *	context,
		const struct rohc_extr_bits *const	bits,
		struct rohc_decoded_values *const	decoded
	)			[static]

Decode ESP values from extracted bits.

The following values are decoded:

• ESP SPI

Parameters:

	context	The decompression context
	bits	The extracted bits
	decoded	OUT: The corresponding decoded values

Returns:

true if decoding is successful, false otherwise

static int esp_parse_dynamic_esp	(	const struct rohc_decomp_ctxt *const	context,
		const uint8_t *	packet,
		const size_t	length,
		struct rohc_extr_bits *const	bits
	)			[static]

Parse the ESP dynamic part of the ROHC packet.

Parameters:

	context	The decompression context
	packet	The ROHC packet to decode
	length	The length of the ROHC packet
	bits	OUT: The bits extracted from the ROHC header

Returns:

The number of bytes read in the ROHC packet, -1 in case of failure

static int esp_parse_static_esp	(	const struct rohc_decomp_ctxt *const	context,
		const uint8_t *	packet,
		size_t	length,
		struct rohc_extr_bits *const	bits
	)			[static]

Parse the ESP static part of the ROHC packet.

Parameters:

	context	The decompression context
	packet	The ROHC packet to decode
	length	The length of the ROHC packet
	bits	OUT: The bits extracted from the ROHC header

Returns:

The number of bytes read in the ROHC packet, -1 in case of failure

static void esp_update_context	(	struct rohc_decomp_ctxt *const	context,
		const struct rohc_decoded_values *const	decoded
	)			[static]

Update context with decoded ESP values.

The following decoded values are updated in context:

• ESP SPI

Parameters:

	context	The decompression context
	decoded	The decoded values to update in the context

---

Variable Documentation

struct rohc_decomp_profile d_esp_profile

Initial value:

{
        .id              = ROHC_PROFILE_ESP, 
        .msn_max_bits    = 32,
        .new_context     = (rohc_decomp_new_context_t) d_esp_create,
        .free_context    = (rohc_decomp_free_context_t) d_esp_destroy,
        .detect_pkt_type = ip_detect_packet_type,
        .parse_pkt       = (rohc_decomp_parse_pkt_t) rfc3095_decomp_parse_pkt,
        .decode_bits     = (rohc_decomp_decode_bits_t) rfc3095_decomp_decode_bits,
        .build_hdrs      = (rohc_decomp_build_hdrs_t) rfc3095_decomp_build_hdrs,
        .update_ctxt     = (rohc_decomp_update_ctxt_t) rfc3095_decomp_update_ctxt,
        .attempt_repair  = (rohc_decomp_attempt_repair_t) rfc3095_decomp_attempt_repair,
        .get_sn          = rohc_decomp_rfc3095_get_sn,
}

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