d_ip.c File Reference

ROHC decompression context for the IP-only profile. More...

#include "d_ip.h"
#include "rohc_traces_internal.h"
#include "rohc_bit_ops.h"
#include "rohc_packets.h"
#include "rohc_debug.h"
#include "rohc_utils.h"
#include "rohc_decomp_detect_packet.h"
#include <assert.h>

Include dependency graph for d_ip.c:

Functions
static bool	d_ip_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 IP decompression context. More...
static void	d_ip_destroy (struct rohc_decomp_rfc3095_ctxt *const rfc3095_ctxt, const struct rohc_decomp_volat_ctxt *const volat_ctxt)
	Destroy the given IP-only context. More...
rohc_packet_t	ip_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 IP-based non-RTP profiles. More...
int	ip_parse_dynamic_ip (const struct rohc_decomp_ctxt *const context, const uint8_t *packet, const size_t length, struct rohc_extr_bits *const bits)
	Parse the IP dynamic part of the ROHC packet. More...
int	ip_parse_ext3 (const struct rohc_decomp_ctxt *const context, const uint8_t *const rohc_data, const size_t rohc_data_len, const rohc_packet_t packet_type, struct rohc_extr_bits *const bits)
	Parse the extension 3 of the UOR-2 packet. More...
int	parse_inner_header_flags (const struct rohc_decomp_ctxt *const context, const uint8_t *const flags, const uint8_t *fields, const size_t length, struct rohc_extr_ip_bits *const bits)
	Parse the inner IP header flags and fields. More...
int	parse_outer_header_flags (const struct rohc_decomp_ctxt *const context, const uint8_t *const flags, const uint8_t *fields, const size_t length, struct rohc_extr_ip_bits *const bits)
	Parse the outer IP header flags and fields. More...

Variables
const struct rohc_decomp_profile	d_ip_profile
	Define the decompression part of the IP-only profile as described in the RFC 3843. More...

Detailed Description

ROHC decompression context for the IP-only 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_ip_create()

static bool d_ip_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 IP 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 UDP context was successfully created, false if a problem occurred

d_ip_destroy()

static void d_ip_destroy ( struct rohc_decomp_rfc3095_ctxt *const  rfc3095_ctxt, const struct rohc_decomp_volat_ctxt *const  volat_ctxt  )

static

Destroy the given IP-only 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

ip_detect_packet_type()

rohc_packet_t ip_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 IP-based non-RTP profiles.

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

ip_parse_dynamic_ip()

int ip_parse_dynamic_ip	(	const struct rohc_decomp_ctxt *const	context,
		const uint8_t *	packet,
		const size_t	length,
		struct rohc_extr_bits *const	bits
	)

Parse the IP 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

ip_parse_ext3()

int ip_parse_ext3	(	const struct rohc_decomp_ctxt *const	context,
		const uint8_t *const	rohc_data,
		const size_t	rohc_data_len,
		const rohc_packet_t	packet_type,
		struct rohc_extr_bits *const	bits
	)

Parse the extension 3 of the UOR-2 packet.

 Extension 3 for non-RTP profiles (5.7.5 & 5.11.4):

       0     1     2     3     4     5     6     7
    +-----+-----+-----+-----+-----+-----+-----+-----+
 1  |  1     1  |  S  |   Mode    |  I  | ip  | ip2 |
    +-----+-----+-----+-----+-----+-----+-----+-----+
 2  |            Inner IP header flags        |     |  if ip = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
 3  |            Outer IP header flags              |  if ip2 = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
 4  |                      SN                       |  if S = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
    |                                               |
 5  /            Inner IP header fields             /  variable,
    |                                               |  if ip = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
 6  |                     IP-ID                     |  2 octets, if I = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
    |                                               |
 7  /            Outer IP header fields             /  variable,
    |                                               |  if ip2 = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+

Parameters

context	The decompression context
rohc_data	The ROHC data to parse
rohc_data_len	The length of the ROHC data to parse
packet_type	The type of ROHC packet to parse
bits	IN: the bits already found in base header OUT: the bits found in the extension header 3

Returns

The data length read from the ROHC packet, -1 in case of error

parse_inner_header_flags()

int parse_inner_header_flags	(	const struct rohc_decomp_ctxt *const	context,
		const uint8_t *const	flags,
		const uint8_t *	fields,
		const size_t	length,
		struct rohc_extr_ip_bits *const	bits
	)

Parse the inner IP header flags and fields.

Store the values in an IP header info structure.

  Inner IP header flags (5.7.5):

       0     1     2     3     4     5     6     7
     ..... ..... ..... ..... ..... ..... ..... .....
    | TOS | TTL | DF  | PR  | IPX | NBO | RND | ip2 |  if ip = 1
     ..... ..... ..... ..... ..... ..... ..... .....

  Inner IP header fields (5.7.5):

    ..... ..... ..... ..... ..... ..... ..... .....
   |         Type of Service/Traffic Class         |  if TOS = 1
    ..... ..... ..... ..... ..... ..... ..... .....
   |         Time to Live/Hop Limit                |  if TTL = 1
    ..... ..... ..... ..... ..... ..... ..... .....
   |         Protocol/Next Header                  |  if PR = 1
    ..... ..... ..... ..... ..... ..... ..... .....
   /         IP extension headers                  /  variable,
    ..... ..... ..... ..... ..... ..... ..... .....   if IPX = 1

Parameters

context	The decompression context
flags	The ROHC flags that indicate which IP fields are present in the packet
fields	The ROHC packet part that contains some IP header fields
length	The length of the ROHC packet part that contains some IP header fields
bits	OUT: The bits extracted from extension 3

Returns

The data length read from the ROHC packet, -1 in case of error

parse_outer_header_flags()

int parse_outer_header_flags	(	const struct rohc_decomp_ctxt *const	context,
		const uint8_t *const	flags,
		const uint8_t *	fields,
		const size_t	length,
		struct rohc_extr_ip_bits *const	bits
	)

Parse the outer IP header flags and fields.

Store the values in an IP header info structure.

  Outer IP header flags (5.7.5):

       0     1     2     3     4     5     6     7
     ..... ..... ..... ..... ..... ..... ..... .....
    | TOS2| TTL2| DF2 | PR2 |IPX2 |NBO2 |RND2 |  I2 |  if ip2 = 1
     ..... ..... ..... ..... ..... ..... ..... .....

  Outer IP header fields

     ..... ..... ..... ..... ..... ..... ..... .....
    |      Type of Service/Traffic Class            |  if TOS2 = 1
     ..... ..... ..... ..... ..... ..... ..... .....
    |         Time to Live/Hop Limit                |  if TTL2 = 1
     ..... ..... ..... ..... ..... ..... ..... .....
    |         Protocol/Next Header                  |  if PR2 = 1
     ..... ..... ..... ..... ..... ..... ..... .....
    /         IP extension header(s)                /  variable,
     ..... ..... ..... ..... ..... ..... ..... .....    if IPX2 = 1
    |                  IP-ID                        |  2 octets,
     ..... ..... ..... ..... ..... ..... ..... .....    if I2 = 1

Parameters

context	The decompression context
flags	The ROHC flags that indicate which IP fields are present in the packet
fields	The ROHC packet part that contain some IP header fields
length	The length of the ROHC packet part that contains some IP header fields
bits	OUT: The bits extracted from extension 3

Returns

The data length read from the ROHC packet, -1 in case of error

Variable Documentation

d_ip_profile

const struct rohc_decomp_profile d_ip_profile

Initial value:

=
{
        .id              = ROHC_PROFILE_IP, 
        .msn_max_bits    = 16,
        .new_context     = (rohc_decomp_new_context_t) d_ip_create,
        .free_context    = (rohc_decomp_free_context_t) d_ip_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 IP-only profile as described in the RFC 3843.