d_udp_lite.c File Reference

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

#include "d_ip.h"
#include "d_udp.h"
#include "rohc_decomp_rfc3095.h"
#include "rohc_bit_ops.h"
#include "rohc_traces_internal.h"
#include "rohc_debug.h"
#include "rohc_utils.h"
#include "rohc_packets.h"
#include "crc.h"
#include "protocols/udp_lite.h"
#include <string.h>

Include dependency graph for d_udp_lite.c:

Data Structures
struct	d_udp_lite_context
	Define the UDP-Lite part of the decompression profile context. More...

Functions
static bool	d_udp_lite_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 UDP-Lite decompression context. More...
static void	d_udp_lite_destroy (struct rohc_decomp_rfc3095_ctxt *const rfc3095_ctxt, const struct rohc_decomp_volat_ctxt *const volat_ctxt)
	Destroy the context. More...
static rohc_packet_t	udp_lite_detect_packet_type (const struct rohc_decomp_ctxt *const context, const uint8_t *const rohc_packet, const size_t rohc_length, const size_t large_cid_len)
	Detect the type of ROHC packet for the UDP-Lite profile. More...
static bool	d_udp_lite_parse (const struct rohc_decomp_ctxt *const context, const struct rohc_buf rohc_packet, const size_t large_cid_len, rohc_packet_t *const packet_type, struct rohc_decomp_crc *const extr_crc, struct rohc_extr_bits *const bits, size_t *const rohc_hdr_len)
	Decode one IR, IR-DYN or UO* packet for UDP-Lite profile. More...
static int	udp_lite_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-Lite dynamic part of the ROHC packet. More...
static int	udp_lite_parse_uo_remainder (const struct rohc_decomp_ctxt *const context, const uint8_t *packet, unsigned int length, struct rohc_extr_bits *const bits)
	Parse the UDP-Lite remainder of the UO* ROHC packets. More...
static bool	udp_lite_decode_values_from_bits (const struct rohc_decomp_ctxt *context, const struct rohc_extr_bits *const bits, struct rohc_decoded_values *const decoded)
	Decode UDP-Lite values from extracted bits. More...
static int	udp_lite_build_uncomp_udp (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 UDP-Lite header. More...
static void	udp_lite_update_context (struct rohc_decomp_ctxt *const context, const struct rohc_decoded_values *const decoded)
	Update context with decoded UDP-Lite values. More...

Variables
const struct rohc_decomp_profile	d_udplite_profile
	Define the decompression part of the UDP-Lite profile as described in the RFC 4019. More...

Detailed Description

ROHC decompression context for the UDP-Lite profile.

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

Function Documentation

d_udp_lite_create()

static bool d_udp_lite_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 UDP-Lite decompression context.

This function is one of the functions that must exist in one profile for the framework to work.

Parameters

	context	The main 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 UDP-Lite context was successfully created, false if a problem occurred

d_udp_lite_destroy()

static void d_udp_lite_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

d_udp_lite_parse()

static bool d_udp_lite_parse ( const struct rohc_decomp_ctxt *const  context, const struct rohc_buf  rohc_packet, const size_t  large_cid_len, rohc_packet_t *const  packet_type, struct rohc_decomp_crc *const  extr_crc, struct rohc_extr_bits *const  bits, size_t *const  rohc_hdr_len  )

static

Decode one IR, IR-DYN or UO* packet for UDP-Lite profile.

This function is one of the functions that must exist in one profile for the framework to work.

Parameters

	context	The decompression context
	rohc_packet	The ROHC packet to decode
	large_cid_len	The length of the optional large CID field
[in,out]	packet_type	IN: The type of the ROHC packet to parse OUT: The type of the parsed ROHC packet
[out]	extr_crc	The CRC bits extracted from the ROHC header
[out]	bits	The bits extracted from the ROHC header
[out]	rohc_hdr_len	The length of the ROHC header (in bytes)

Returns

true if packet is successfully parsed, false otherwise

udp_lite_build_uncomp_udp()

static int udp_lite_build_uncomp_udp ( 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 UDP-Lite header.

Todo:

check for dest size before writing into it

Parameters

context	The decompression context
decoded	The values decoded from the ROHC header
dest	The buffer to store the UDP-Lite header
payload_len	The length of the UDP-Lite payload

Returns

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

udp_lite_decode_values_from_bits()

static bool udp_lite_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 UDP-Lite values from extracted bits.

The following values are decoded:

• UDP-Lite source port
• UDP-Lite destination port
• UDP-Lite checksum
• UDP-Lite Checksum Coverage (CC)

Parameters

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

Returns

true if decoding is successful, false otherwise

udp_lite_detect_packet_type()

static rohc_packet_t udp_lite_detect_packet_type ( const struct rohc_decomp_ctxt *const  context, const uint8_t *const  rohc_packet, const size_t  rohc_length, const size_t  large_cid_len  )

static

Detect the type of ROHC packet for the UDP-Lite profile.

Parse optional CCE packet type, then normal packet type.

Parameters

context	The decompression context
rohc_packet	The ROHC packet
rohc_length	The length of the ROHC packet
large_cid_len	The length of the optional large CID field

Returns

The packet type

udp_lite_parse_dynamic_udp()

static int udp_lite_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-Lite 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

udp_lite_parse_uo_remainder()

static int udp_lite_parse_uo_remainder ( const struct rohc_decomp_ctxt *const  context, const uint8_t *  packet, unsigned int  length, struct rohc_extr_bits *const  bits  )

static

Parse the UDP-Lite remainder 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

udp_lite_update_context()

static void udp_lite_update_context ( struct rohc_decomp_ctxt *const  context, const struct rohc_decoded_values *const  decoded  )

static

Update context with decoded UDP-Lite values.

The following decoded values are updated in context:

• UDP-Lite source port
• UDP-Lite destination port

Parameters

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

Variable Documentation

d_udplite_profile

const struct rohc_decomp_profile d_udplite_profile

Initial value:

=
{
        .id              = ROHC_PROFILE_UDPLITE, 
        .msn_max_bits    = 16,
        .new_context     = (rohc_decomp_new_context_t) d_udp_lite_create,
        .free_context    = (rohc_decomp_free_context_t) d_udp_lite_destroy,
        .detect_pkt_type = udp_lite_detect_packet_type,
        .parse_pkt       = (rohc_decomp_parse_pkt_t) d_udp_lite_parse,
        .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 UDP-Lite profile as described in the RFC 4019.