d_udp.c File Reference

ROHC decompression context for the UDP profile. More...

#include "d_udp.h"
#include "d_ip.h"
#include "rohc_traces_internal.h"
#include "rohc_bit_ops.h"
#include "rohc_debug.h"
#include "rohc_utils.h"
#include "crc.h"
#include "protocols/udp.h"
#include <string.h>
#include <assert.h>

Include dependency graph for d_udp.c:

Data Structures
struct	d_udp_context
	Define the UDP part of the decompression profile context. More...
Functions
static void	d_udp_destroy (void *const context)
	Destroy the context.
static int	udp_parse_dynamic_udp (const struct rohc_decomp_ctxt *const context, const uint8_t *packet, const size_t length, struct rohc_extr_bits *const bits)
	Parse the UDP dynamic part of the ROHC packet.
static int	udp_parse_uo_remainder (const struct rohc_decomp_ctxt *const context, const unsigned char *packet, unsigned int length, struct rohc_extr_bits *const bits)
	Parse the UDP tail of the UO* ROHC packets.
static bool	udp_decode_values_from_bits (const struct rohc_decomp_ctxt *context, const struct rohc_extr_bits bits, struct rohc_decoded_values *const decoded)
	Decode UDP values from extracted bits.
static int	udp_build_uncomp_udp (const struct rohc_decomp_ctxt *const context, const struct rohc_decoded_values decoded, unsigned char *dest, const unsigned int payload_len)
	Build an uncompressed UDP header.
void *	d_udp_create (const struct rohc_decomp_ctxt *const context)
	Create the UDP decompression context.
int	udp_parse_static_udp (const struct rohc_decomp_ctxt *const context, const unsigned char *packet, size_t length, struct rohc_extr_bits *const bits)
	Parse the UDP static part of the ROHC packet.
void	udp_update_context (const struct rohc_decomp_ctxt *context, const struct rohc_decoded_values decoded)
	Update context with decoded UDP values.
Variables
struct rohc_decomp_profile	d_udp_profile
	Define the decompression part of the UDP profile as described in the RFC 3095.

---

Detailed Description

ROHC decompression context for the UDP profile.

Author:

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

Didier Barvaux <didier@barvaux.org>

---

Function Documentation

void* d_udp_create

(

const struct rohc_decomp_ctxt *const

context

)

Create the UDP 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

Returns:

The newly-created UDP decompression context

static void d_udp_destroy

(

void *const

context

)

[static]

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

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

Build an uncompressed UDP header.

Parameters:

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

Returns:

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

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

Decode UDP values from extracted bits.

The following values are decoded:

• UDP source port
• UDP destination port
• UDP checksum

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

Parse the UDP dynamic part of the ROHC packet.

Parameters:

context	The decompression context
packet	The ROHC packet to parse
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

int udp_parse_static_udp	(	const struct rohc_decomp_ctxt *const	context,
		const unsigned char *	packet,
		size_t	length,
		struct rohc_extr_bits *const	bits
	)

Parse the UDP static part of the ROHC packet.

Parameters:

context	The decompression context
packet	The ROHC packet to parse
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 udp_parse_uo_remainder	(	const struct rohc_decomp_ctxt *const	context,
		const unsigned char *	packet,
		unsigned int	length,
		struct rohc_extr_bits *const	bits
	)		[static]

Parse the UDP tail of the UO* ROHC packets.

Parameters:

context	The decompression context
packet	The ROHC packet to parse
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

void udp_update_context	(	const struct rohc_decomp_ctxt *	context,
		const struct rohc_decoded_values	decoded
	)

Update context with decoded UDP values.

The following decoded values are updated in context:

• UDP source port
• UDP destination port

Parameters:

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

---

Variable Documentation

struct rohc_decomp_profile d_udp_profile

Initial value:

{
        .id              = ROHC_PROFILE_UDP, 
        .new_context     = d_udp_create,
        .free_context    = d_udp_destroy,
        .decode          = d_generic_decode,
        .detect_pkt_type = ip_detect_packet_type,
        .get_sn          = d_generic_get_sn,
}

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