ROHC ESP compression profile. More...

#include "c_generic.h"
#include "c_ip.h"
#include "rohc_traces_internal.h"
#include "crc.h"
#include "protocols/esp.h"
#include "rohc_utils.h"
#include <stdbool.h>
#include <string.h>
#include <assert.h>

Include dependency graph for c_esp.c:

Data Structures
struct	sc_esp_context
	Define the ESP part of the profile decompression context. More...
Functions
static bool	c_esp_create (struct rohc_comp_ctxt const context, const struct net_pkt const packet)
	Create a new ESP context and initialize it thanks to the given IP/ESP packet.
static bool	c_esp_check_profile (const struct rohc_comp const comp, const struct net_pkt const packet)
	Check if the given packet corresponds to the ESP profile.
static bool	c_esp_check_context (const struct rohc_comp_ctxt const context, const struct net_pkt const packet)
	Check if the IP/ESP packet belongs to the context.
static int	c_esp_encode (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, unsigned char const rohc_pkt, const size_t rohc_pkt_max_len, rohc_packet_t const packet_type, size_t *const payload_offset)
	Encode an IP/ESP packet according to a pattern decided by several different factors.
static uint32_t	c_esp_get_next_sn (const struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt)
	Determine the SN value for the next packet.
static size_t	esp_code_static_esp_part (const struct rohc_comp_ctxt const context, const unsigned char const next_header, unsigned char *const dest, const size_t counter)
	Build the static part of the ESP header.
static size_t	esp_code_dynamic_esp_part (const struct rohc_comp_ctxt const context, const unsigned char const next_header, unsigned char *const dest, const size_t counter)
	Build the dynamic part of the ESP header.
Variables
struct rohc_comp_profile	c_esp_profile
	Define the compression part of the ESP profile as described in the RFC 3095.

Detailed Description

ROHC ESP compression profile.

Author:: FWX <rohc_team@dialine.fr>; Didier Barvaux <didier@barvaux.org>

Function Documentation

static bool c_esp_check_context	(	const struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	packet
	)		`[static]`

Check if the IP/ESP packet belongs to the context.

Conditions are:

the number of IP headers must be the same as in context
IP version of the two IP headers must be the same as in context
IP packets must not be fragmented
the source and destination addresses of the two IP headers must match the ones in the context
the transport protocol must be ESP
the security parameters index of the ESP header must match the one in the context
IPv6 only: the Flow Label of the two IP headers must match the ones 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
packet	The IP/UDP packet to check

Returns:: true if the packet belongs to the context, false if it does not belong to the context

static bool c_esp_check_profile	(	const struct rohc_comp *const	comp,
		const struct net_pkt *const	packet
	)		`[static]`

Check if the given packet corresponds to the ESP profile.

Conditions are:

the transport protocol is ESP
the version of the outer IP header is 4 or 6
the outer IP header is not an IP fragment
if there are at least 2 IP headers, the version of the inner IP header is 4 or 6
if there are at least 2 IP headers, the inner IP header is not an IP fragment

See also:: c_generic_check_profile

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

Parameters:

comp	The ROHC compressor
packet	The packet to check

Returns:

Whether the IP packet corresponds to the profile:

true if the IP packet corresponds to the profile,
false if the IP packet does not correspond to the profile

static bool c_esp_create	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	packet
	)		`[static]`

Create a new ESP context and initialize it thanks to the given IP/ESP packet.

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

Parameters:

context	The compression context
packet	The IP/ESP packet given to initialize the new context

Returns:: true if successful, false otherwise

static int c_esp_encode	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		unsigned char *const	rohc_pkt,
		const size_t	rohc_pkt_max_len,
		rohc_packet_t *const	packet_type,
		size_t *const	payload_offset
	)		`[static]`

Encode an IP/ESP packet according to a pattern decided by several different factors.

Parameters:

context	The compression context
uncomp_pkt	The uncompressed packet to encode
rohc_pkt	OUT: The ROHC packet
rohc_pkt_max_len	The maximum length of the ROHC packet
packet_type	OUT: The type of ROHC packet that is created
payload_offset	OUT: The offset for the payload in the IP packet

Returns:: The length of the ROHC packet if successful, -1 otherwise

static uint32_t c_esp_get_next_sn	(	const struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt
	)		`[static]`

Determine the SN value for the next packet.

Profile SN is the ESP SN.

Parameters:

context	The compression context
uncomp_pkt	The uncompressed packet to encode

Returns:: The SN

static size_t esp_code_dynamic_esp_part	(	const struct rohc_comp_ctxt *const	context,
		const unsigned char *const	next_header,
		unsigned char *const	dest,
		const size_t	counter
	)		`[static]`

Build the dynamic part of the ESP header.


 Dynamic part of ESP header (5.7.7.7):

    +---+---+---+---+---+---+---+---+
 1  /       Sequence Number         /   4 octets
    +---+---+---+---+---+---+---+---+

Parameters:

context	The compression context
next_header	The ESP header
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns:: The new position in the rohc-packet-under-build buffer

static size_t esp_code_static_esp_part	(	const struct rohc_comp_ctxt *const	context,
		const unsigned char *const	next_header,
		unsigned char *const	dest,
		const size_t	counter
	)		`[static]`

Build the static part of the ESP header.


 Static part of ESP header (5.7.7.7):

    +---+---+---+---+---+---+---+---+
 1  /              SPI              /   4 octets
    +---+---+---+---+---+---+---+---+

 SPI = Security Parameters Index

Parameters:

context	The compression context
next_header	The ESP header
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns:: The new position in the rohc-packet-under-build buffer

Variable Documentation

struct rohc_comp_profile c_esp_profile

Initial value:

{
        .id             = ROHC_PROFILE_ESP, 
        .protocol       = ROHC_IPPROTO_ESP, 
        .create         = c_esp_create,     
        .destroy        = c_generic_destroy,
        .check_profile  = c_esp_check_profile,
        .check_context  = c_esp_check_context,
        .encode         = c_esp_encode,
        .reinit_context = c_generic_reinit_context,
        .feedback       = c_generic_feedback,
        .use_udp_port   = c_generic_use_udp_port,
}

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

Data Structures

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation