ROHC compression context for the TCP profile. More...

#include "rohc_traces_internal.h"
#include "rohc_utils.h"
#include "rohc_packets.h"
#include "protocols/tcp.h"
#include "schemes/cid.h"
#include "schemes/rfc4996.h"
#include "sdvl.h"
#include "crc.h"
#include "c_generic.h"
#include "c_ip.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"

Include dependency graph for c_tcp.c:

Data Structures
struct	tcp_tmp_variables
	Define the TCP-specific temporary variables in the profile compression context. More...
struct	ipv6_option_context
	Define the IPv6 generic option context. More...
struct	ipv6_gre_option_context
	Define the IPv6 GRE option context. More...
struct	ipv6_mime_option_context
	Define the IPv6 MIME option context. More...
struct	ipv6_ah_option_context
	Define the IPv6 AH option context. More...
struct	ipvx_context
	Define the common IP header context to IPv4 and IPv6. More...
struct	ipv4_context
	Define the IPv4 header context. More...
struct	ipv6_context
	Define the IPv6 header context. More...
union	ip_context_ptr_t
	Define union of IP contexts pointers. More...
struct	tcp_opt_context
	The compression context for one TCP option. More...
struct	sc_tcp_context
	Define the TCP part of the profile decompression context. More...
Defines
#define	TRACE_GOTO_CHOICE rohc_comp_debug(context, "Compressed format choice LINE %d", __LINE__ )
#define	MAX_IPV6_OPTION_LENGTH 6
#define	MAX_IPV6_CONTEXT_OPTION_SIZE (2 + ((MAX_IPV6_OPTION_LENGTH + 1) << 3))
#define	MAX_TCP_OPT_SIZE 40U
#define	TCP_LIST_ITEM_MAP_LEN 16U
Typedefs
typedef struct ipv6_option_context	ipv6_option_context_t
	Define the IPv6 generic option context.
typedef struct ipv6_gre_option_context	ipv6_gre_option_context_t
	Define the IPv6 GRE option context.
typedef struct ipv6_mime_option_context	ipv6_mime_option_context_t
	Define the IPv6 MIME option context.
typedef struct ipv6_ah_option_context	ipv6_ah_option_context_t
	Define the IPv6 AH option context.
typedef struct ipvx_context	ipvx_context_t
	Define the common IP header context to IPv4 and IPv6.
typedef struct ipv4_context	ipv4_context_t
	Define the IPv4 header context.
typedef struct ipv6_context	ipv6_context_t
	Define the IPv6 header context.
Functions
static bool	c_tcp_create (struct rohc_comp_ctxt const context, const struct net_pkt const packet)
	Create a new TCP context and initialize it thanks to the given IP/TCP packet.
static void	c_tcp_destroy (struct rohc_comp_ctxt *const context)
	Destroy the TCP context.
static bool	c_tcp_check_profile (const struct rohc_comp const comp, const struct net_pkt const packet)
	Check if the given packet corresponds to the TCP profile.
static bool	c_tcp_check_context (const struct rohc_comp_ctxt const context, const struct net_pkt const packet)
	Check if the IP/TCP packet belongs to the context.
static int	c_tcp_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/TCP packet according to a pattern decided by several different factors.
static bool	tcp_detect_changes (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt)
	Detect changes between packet and context.
static void	tcp_decide_state (struct rohc_comp_ctxt *const context)
	Decide the state that should be used for the next packet.
static bool	tcp_encode_uncomp_fields (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt)
	Encode uncompressed fields with the corresponding encoding scheme.
static rohc_packet_t	tcp_decide_packet (const struct rohc_comp_ctxt const context, const ip_context_ptr_t const ip_inner_context, const tcphdr_t *const tcp)
	Decide which packet to send when in the different states.
static rohc_packet_t	tcp_decide_SO_packet (const struct rohc_comp_ctxt const context, const ip_context_ptr_t const ip_inner_context, const tcphdr_t *const tcp)
	Decide which packet to send when in SO state.
static uint8_t *	tcp_code_static_ipv6_option_part (struct rohc_comp_ctxt *const context, multi_ptr_t mptr, uint8_t protocol, base_header_ip_t base_header)
	Build the static part of the IPv6 option header.
static uint8_t *	tcp_code_dynamic_ipv6_option_part (struct rohc_comp_ctxt *const context, ip_context_ptr_t ip_context, multi_ptr_t mptr, uint8_t protocol, base_header_ip_t base_header)
	Build the dynamic part of the IPv6 option header.
static uint8_t *	tcp_code_irregular_ipv6_option_part (struct rohc_comp_ctxt *const context, ip_context_ptr_t ip_context, multi_ptr_t mptr, uint8_t protocol, base_header_ip_t base_header)
	Build the irregular part of the IPv6 option header.
static uint8_t *	tcp_code_static_ip_part (struct rohc_comp_ctxt *const context, base_header_ip_t base_header, multi_ptr_t mptr)
	Build the static part of the IP header.
static uint8_t *	tcp_code_dynamic_ip_part (const struct rohc_comp_ctxt *context, ip_context_ptr_t ip_context, base_header_ip_t base_header, multi_ptr_t mptr, int is_innermost)
	Build the dynamic part of the IP header.
static uint8_t *	tcp_code_irregular_ip_part (struct rohc_comp_ctxt const context, ip_context_ptr_t ip_context, base_header_ip_t base_header, uint8_t rohc_data, int ecn_used, int is_innermost, int ttl_irregular_chain_flag, int ip_inner_ecn)
	Build the irregular part of the IP header.
static uint8_t *	tcp_code_static_tcp_part (const struct rohc_comp_ctxt context, const tcphdr_t tcp, multi_ptr_t mptr)
	Build the static part of the TCP header.
static uint8_t *	tcp_code_dynamic_tcp_part (const struct rohc_comp_ctxt context, const unsigned char next_header, multi_ptr_t mptr)
	Build the dynamic part of the TCP header.
static uint8_t *	tcp_code_irregular_tcp_part (struct rohc_comp_ctxt const context, tcphdr_t tcp, uint8_t *const rohc_data, int ip_inner_ecn)
	Build the irregular part of the TCP header.
static int	code_CO_packet (struct rohc_comp_ctxt const context, const struct ip_packet ip, const int packet_size, const unsigned char next_header, unsigned char const rohc_pkt, const size_t rohc_pkt_max_len, const rohc_packet_t packet_type, size_t *const payload_offset)
	Build the CO packet.
static int	co_baseheader (struct rohc_comp_ctxt const context, struct sc_tcp_context const tcp_context, ip_context_ptr_t ip_context, base_header_ip_t base_header, unsigned char const rohc_pkt, const size_t rohc_pkt_max_len,const rohc_packet_t packet_type, const tcphdr_t const tcp, const uint8_t crc)
	Compress the innermost IP header AND the TCP header.
static size_t	c_tcp_build_rnd_1 (struct rohc_comp_ctxt const context, struct sc_tcp_context const tcp_context, const tcphdr_t const tcp, const uint8_t crc, rnd_1_t const rnd1)
	Build a TCP rnd_1 packet.
static size_t	c_tcp_build_rnd_2 (struct rohc_comp_ctxt const context, struct sc_tcp_context const tcp_context, const tcphdr_t const tcp, const uint8_t crc, rnd_2_t const rnd2)
	Build a TCP rnd_2 packet.
static size_t	c_tcp_build_rnd_3 (struct rohc_comp_ctxt const context, struct sc_tcp_context const tcp_context, const tcphdr_t const tcp, const uint8_t crc, rnd_3_t const rnd3)
	Build a TCP rnd_3 packet.
static size_t	c_tcp_build_rnd_4 (struct rohc_comp_ctxt const context, struct sc_tcp_context const tcp_context, const tcphdr_t const tcp, const uint8_t crc, rnd_4_t const rnd4)
	Build a TCP rnd_4 packet.
static size_t	c_tcp_build_rnd_5 (struct rohc_comp_ctxt const context, struct sc_tcp_context const tcp_context, const tcphdr_t const tcp, const uint8_t crc, rnd_5_t const rnd5)
	Build a TCP rnd_5 packet.
static size_t	c_tcp_build_rnd_6 (struct rohc_comp_ctxt const context, struct sc_tcp_context const tcp_context, const tcphdr_t const tcp, const uint8_t crc, rnd_6_t const rnd6)
	Build a TCP rnd_6 packet.
static size_t	c_tcp_build_rnd_7 (struct rohc_comp_ctxt const context, struct sc_tcp_context const tcp_context, const tcphdr_t const tcp, const uint8_t crc, rnd_7_t const rnd7)
	Build a TCP rnd_7 packet.
static bool	c_tcp_build_rnd_8 (struct rohc_comp_ctxt const context, const ip_context_ptr_t ip_context, struct sc_tcp_context const tcp_context, const base_header_ip_t ip, const tcphdr_t const tcp, const uint8_t crc, rnd_8_t const rnd8, size_t *const rnd8_len)
	Build a TCP rnd_8 packet.
static size_t	c_tcp_build_seq_1 (struct rohc_comp_ctxt const context, const ip_context_ptr_t ip_context, struct sc_tcp_context const tcp_context, const base_header_ip_t ip, const tcphdr_t const tcp, const uint8_t crc, seq_1_t const seq1)
	Build a TCP seq_1 packet.
static size_t	c_tcp_build_seq_2 (struct rohc_comp_ctxt const context, const ip_context_ptr_t ip_context, struct sc_tcp_context const tcp_context, const base_header_ip_t ip, const tcphdr_t const tcp, const uint8_t crc, seq_2_t const seq2)
	Build a TCP seq_2 packet.
static size_t	c_tcp_build_seq_3 (struct rohc_comp_ctxt const context, const ip_context_ptr_t ip_context, struct sc_tcp_context const tcp_context, const base_header_ip_t ip, const tcphdr_t const tcp, const uint8_t crc, seq_3_t const seq3)
	Build a TCP seq_3 packet.
static size_t	c_tcp_build_seq_4 (struct rohc_comp_ctxt const context, const ip_context_ptr_t ip_context, struct sc_tcp_context const tcp_context, const base_header_ip_t ip, const tcphdr_t const tcp, const uint8_t crc, seq_4_t const seq4)
	Build a TCP seq_4 packet.
static size_t	c_tcp_build_seq_5 (struct rohc_comp_ctxt const context, const ip_context_ptr_t ip_context, struct sc_tcp_context const tcp_context, const base_header_ip_t ip, const tcphdr_t const tcp, const uint8_t crc, seq_5_t const seq5)
	Build a TCP seq_5 packet.
static size_t	c_tcp_build_seq_6 (struct rohc_comp_ctxt const context, const ip_context_ptr_t ip_context, struct sc_tcp_context const tcp_context, const base_header_ip_t ip, const tcphdr_t const tcp, const uint8_t crc, seq_6_t const seq6)
	Build a TCP seq_6 packet.
static size_t	c_tcp_build_seq_7 (struct rohc_comp_ctxt const context, const ip_context_ptr_t ip_context, struct sc_tcp_context const tcp_context, const base_header_ip_t ip, const tcphdr_t const tcp, const uint8_t crc, seq_7_t const seq7)
	Build a TCP seq_7 packet.
static bool	c_tcp_build_seq_8 (struct rohc_comp_ctxt const context, const ip_context_ptr_t ip_context, struct sc_tcp_context const tcp_context, const base_header_ip_t ip, const tcphdr_t const tcp, const uint8_t crc, seq_8_t const seq8, size_t *const seq8_len)
	Build a TCP seq_8 packet.
static bool	tcp_compress_tcp_options (struct rohc_comp_ctxt const context, const tcphdr_t const tcp, uint8_t const comp_opts, size_t const comp_opts_len)
	Compress the TCP options.
static bool	c_ts_lsb (const struct rohc_comp_ctxt const context, uint8_t *dest, const uint32_t timestamp, const size_t nr_bits_minus_1, const size_t nr_bits_0x40000)
	Compress the TimeStamp option value.
static uint8_t *	c_tcp_opt_sack (const struct rohc_comp_ctxt const context, uint8_t ptr, uint32_t ack_value, uint8_t length, const sack_block_t *const sack_block)
	Compress the SACK TCP option.
static tcp_ip_id_behavior_t	tcp_detect_ip_id_behavior (const uint16_t last_ip_id, const uint16_t new_ip_id)
	Detect the behavior of the IPv4 Identification field.
static void	tcp_field_descr_change (const struct rohc_comp_ctxt const context, const char const name, const bool changed)
	Print a debug trace for the field change.
static void	tcp_field_descr_present (const struct rohc_comp_ctxt const context, const char const name, const bool present)
	Print a debug trace for the field presence.
static char *	tcp_ip_id_behavior_get_descr (const tcp_ip_id_behavior_t behavior)
	Get a string that describes the given IP-ID behavior.
static char *	tcp_opt_get_descr (const uint8_t opt_type)
	Get a string that describes the given option type.
static uint8_t *	c_sack_pure_lsb (const struct rohc_comp_ctxt const context, uint8_t ptr, uint32_t base, uint32_t field)
	Compress the SACK field value.
static uint8_t *	c_sack_block (const struct rohc_comp_ctxt const context, uint8_t ptr, uint32_t reference, const sack_block_t *const sack_block)
	Compress a SACK block.
static uint8_t *	c_tcp_opt_generic (struct sc_tcp_context tcp_context, uint8_t ptr, uint8_t *options)
	Compress a generic TCP option.
Variables
static int	tcp_options_index [TCP_LIST_ITEM_MAP_LEN]
	Table of TCP option index, from option Id.
struct rohc_comp_profile	c_tcp_profile
	Define the compression part of the TCP profile as described in the RFC 3095.

Detailed Description

ROHC compression context for the TCP profile.

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

Define Documentation

#define MAX_IPV6_CONTEXT_OPTION_SIZE (2 + ((MAX_IPV6_OPTION_LENGTH + 1) << 3))

#define MAX_IPV6_OPTION_LENGTH 6

#define MAX_TCP_OPT_SIZE 40U

The maximum size (in bytes) of one TCP option

#define TCP_LIST_ITEM_MAP_LEN 16U

The length of the table mapping for TCP options

#define TRACE_GOTO_CHOICE rohc_comp_debug(context, "Compressed format choice LINE %d", __LINE__ )

Typedef Documentation

typedef struct ipv4_context ipv4_context_t

Define the IPv4 header context.

typedef struct ipv6_ah_option_context ipv6_ah_option_context_t

Define the IPv6 AH option context.

typedef struct ipv6_context ipv6_context_t

Define the IPv6 header context.

typedef struct ipv6_gre_option_context ipv6_gre_option_context_t

Define the IPv6 GRE option context.

typedef struct ipv6_mime_option_context ipv6_mime_option_context_t

Define the IPv6 MIME option context.

typedef struct ipv6_option_context ipv6_option_context_t

Define the IPv6 generic option context.

typedef struct ipvx_context ipvx_context_t

Define the common IP header context to IPv4 and IPv6.

Function Documentation

static uint8_t* c_sack_block	(	const struct rohc_comp_ctxt *const	context,
		uint8_t *	ptr,
		uint32_t	reference,
		const sack_block_t *const	sack_block
	)		`[static]`

Compress a SACK block.

See RFC6846 page 68 (and RFC2018 for Selective Acknowledgement option)

Parameters:

context	The compression context
ptr	Pointer to the compressed value
reference	The reference value
sack_block	Pointer to the SACK block to compress

Returns:: Pointer after the compressed value

static uint8_t* c_sack_pure_lsb	(	const struct rohc_comp_ctxt *const	context,
		uint8_t *	ptr,
		uint32_t	base,
		uint32_t	field
	)		`[static]`

Compress the SACK field value.

See RFC6846 page 67 (and RFC2018 for Selective Acknowledgement option)

Parameters:

context	The compression context
ptr	Pointer to the compressed value
base	The base value
field	The value to compress

Returns:: Pointer after the compressed value

static size_t c_tcp_build_rnd_1	(	struct rohc_comp_ctxt *const	context,
		struct sc_tcp_context *const	tcp_context,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		rnd_1_t *const	rnd1
	)		`[static]`

Build a TCP rnd_1 packet.

Send LSBs of sequence number See RFC4996 page 81

Parameters:

context	The compression context
tcp_context	The specific TCP context
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
rnd1	IN/OUT: The rnd_1 packet to build

Returns:: The length (in bytes) of the rnd_1 packet

static size_t c_tcp_build_rnd_2	(	struct rohc_comp_ctxt *const	context,
		struct sc_tcp_context *const	tcp_context,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		rnd_2_t *const	rnd2
	)		`[static]`

Build a TCP rnd_2 packet.

Send scaled sequence number LSBs See RFC4996 page 81

Parameters:

context	The compression context
tcp_context	The specific TCP context
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
rnd2	IN/OUT: The rnd_2 packet to build

Returns:: The length (in bytes) of the rnd_2 packet

static size_t c_tcp_build_rnd_3	(	struct rohc_comp_ctxt *const	context,
		struct sc_tcp_context *const	tcp_context,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		rnd_3_t *const	rnd3
	)		`[static]`

Build a TCP rnd_3 packet.

Send acknowlegment number LSBs See RFC4996 page 81

Parameters:

context	The compression context
tcp_context	The specific TCP context
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
rnd3	IN/OUT: The rnd_3 packet to build

Returns:: The length (in bytes) of the rnd_3 packet

static size_t c_tcp_build_rnd_4	(	struct rohc_comp_ctxt *const	context,
		struct sc_tcp_context *const	tcp_context,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		rnd_4_t *const	rnd4
	)		`[static]`

Build a TCP rnd_4 packet.

Send acknowlegment number scaled See RFC4996 page 81

Parameters:

context	The compression context
tcp_context	The specific TCP context
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
rnd4	IN/OUT: The rnd_4 packet to build

Returns:: The length (in bytes) of the rnd_4 packet

static size_t c_tcp_build_rnd_5	(	struct rohc_comp_ctxt *const	context,
		struct sc_tcp_context *const	tcp_context,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		rnd_5_t *const	rnd5
	)		`[static]`

Build a TCP rnd_5 packet.

Send ACK and sequence number See RFC4996 page 82

Parameters:

context	The compression context
tcp_context	The specific TCP context
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
rnd5	IN/OUT: The rnd_5 packet to build

Returns:: The length (in bytes) of the rnd_5 packet

static size_t c_tcp_build_rnd_6	(	struct rohc_comp_ctxt *const	context,
		struct sc_tcp_context *const	tcp_context,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		rnd_6_t *const	rnd6
	)		`[static]`

Build a TCP rnd_6 packet.

Send both ACK and scaled sequence number LSBs See RFC4996 page 82

Parameters:

context	The compression context
tcp_context	The specific TCP context
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
rnd6	IN/OUT: The rnd_6 packet to build

Returns:: The length (in bytes) of the rnd_6 packet

static size_t c_tcp_build_rnd_7	(	struct rohc_comp_ctxt *const	context,
		struct sc_tcp_context *const	tcp_context,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		rnd_7_t *const	rnd7
	)		`[static]`

Build a TCP rnd_7 packet.

Send ACK and window See RFC4996 page 82

Parameters:

context	The compression context
tcp_context	The specific TCP context
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
rnd7	IN/OUT: The rnd_7 packet to build

Returns:: The length (in bytes) of the rnd_7 packet

static bool c_tcp_build_rnd_8	(	struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t	ip_context,
		struct sc_tcp_context *const	tcp_context,
		const base_header_ip_t	ip,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		rnd_8_t *const	rnd8,
		size_t *const	rnd8_len
	)		`[static]`

Build a TCP rnd_8 packet.

Send LSBs of TTL, RSF flags, change ECN behavior and options list See RFC4996 page 82

Parameters:

context	The compression context
ip_context	The specific IP innermost context
tcp_context	The specific TCP context
ip	The IPv4 or IPv6 header to compress
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
rnd8	IN/OUT: The rnd_8 packet to build
rnd8_len	OUT: The length (in bytes) of the rnd_8 packet

Returns:: true if the packet is successfully built, false otherwise

static size_t c_tcp_build_seq_1	(	struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t	ip_context,
		struct sc_tcp_context *const	tcp_context,
		const base_header_ip_t	ip,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		seq_1_t *const	seq1
	)		`[static]`

Build a TCP seq_1 packet.

Send LSBs of sequence number See RFC4996 page 83

Parameters:

context	The compression context
ip_context	The specific IP innermost context
tcp_context	The specific TCP context
ip	The IPv4 or IPv6 header to compress
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
seq1	IN/OUT: The seq_1 packet to build

Returns:: The length (in bytes) of the seq_1 packet

static size_t c_tcp_build_seq_2	(	struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t	ip_context,
		struct sc_tcp_context *const	tcp_context,
		const base_header_ip_t	ip,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		seq_2_t *const	seq2
	)		`[static]`

Build a TCP seq_2 packet.

Send scaled sequence number LSBs See RFC4996 page 83

Parameters:

context	The compression context
ip_context	The specific IP innermost context
tcp_context	The specific TCP context
ip	The IPv4 or IPv6 header to compress
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
seq2	IN/OUT: The seq_2 packet to build

Returns:: The length (in bytes) of the seq_2 packet

static size_t c_tcp_build_seq_3	(	struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t	ip_context,
		struct sc_tcp_context *const	tcp_context,
		const base_header_ip_t	ip,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		seq_3_t *const	seq3
	)		`[static]`

Build a TCP seq_3 packet.

Send acknowledgment number LSBs See RFC4996 page 83

Parameters:

context	The compression context
ip_context	The specific IP innermost context
tcp_context	The specific TCP context
ip	The IPv4 or IPv6 header to compress
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
seq3	IN/OUT: The seq_3 packet to build

Returns:: The length (in bytes) of the seq_3 packet

static size_t c_tcp_build_seq_4	(	struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t	ip_context,
		struct sc_tcp_context *const	tcp_context,
		const base_header_ip_t	ip,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		seq_4_t *const	seq4
	)		`[static]`

Build a TCP seq_4 packet.

Send scaled acknowledgment number scaled See RFC4996 page 84

Parameters:

context	The compression context
ip_context	The specific IP innermost context
tcp_context	The specific TCP context
ip	The IPv4 or IPv6 header to compress
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
seq4	IN/OUT: The seq_4 packet to build

Returns:: The length (in bytes) of the seq_4 packet

static size_t c_tcp_build_seq_5	(	struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t	ip_context,
		struct sc_tcp_context *const	tcp_context,
		const base_header_ip_t	ip,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		seq_5_t *const	seq5
	)		`[static]`

Build a TCP seq_5 packet.

Send ACK and sequence number See RFC4996 page 84

Parameters:

context	The compression context
ip_context	The specific IP innermost context
tcp_context	The specific TCP context
ip	The IPv4 or IPv6 header to compress
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
seq5	IN/OUT: The seq_5 packet to build

Returns:: The length (in bytes) of the seq_5 packet

static size_t c_tcp_build_seq_6	(	struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t	ip_context,
		struct sc_tcp_context *const	tcp_context,
		const base_header_ip_t	ip,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		seq_6_t *const	seq6
	)		`[static]`

Build a TCP seq_6 packet.

See RFC4996 page 84

Parameters:

context	The compression context
ip_context	The specific IP innermost context
tcp_context	The specific TCP context
ip	The IPv4 or IPv6 header to compress
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
seq6	IN/OUT: The seq_6 packet to build

Returns:: The length (in bytes) of the seq_6 packet

static size_t c_tcp_build_seq_7	(	struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t	ip_context,
		struct sc_tcp_context *const	tcp_context,
		const base_header_ip_t	ip,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		seq_7_t *const	seq7
	)		`[static]`

Build a TCP seq_7 packet.

Send ACK and window See RFC4996 page 85

Parameters:

context	The compression context
ip_context	The specific IP innermost context
tcp_context	The specific TCP context
ip	The IPv4 or IPv6 header to compress
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
seq7	IN/OUT: The seq_7 packet to build

Returns:: The length (in bytes) of the seq_7 packet

static bool c_tcp_build_seq_8	(	struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t	ip_context,
		struct sc_tcp_context *const	tcp_context,
		const base_header_ip_t	ip,
		const tcphdr_t *const	tcp,
		const uint8_t	crc,
		seq_8_t *const	seq8,
		size_t *const	seq8_len
	)		`[static]`

Build a TCP seq_8 packet.

Send LSBs of TTL, RSF flags, change ECN behavior, and options list See RFC4996 page 85

Parameters:

context	The compression context
ip_context	The specific IP innermost context
tcp_context	The specific TCP context
ip	The IPv4 or IPv6 header to compress
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers
seq8	IN/OUT: The seq_8 packet to build
seq8_len	OUT: The length (in bytes) of the seq_8 packet

Returns:: true if the packet is successfully built, false otherwise

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

Check if the IP/TCP 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 TCP
the source and destination ports of the TCP header must match the ones 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/TCP packet to check

Returns:: true if the IP/TCP packet belongs to the context false if it does not belong to the context

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

Check if the given packet corresponds to the TCP profile.

Conditions are:

the transport protocol is TCP
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_tcp_create	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	packet
	)		`[static]`

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

Returns:: true if successful, false otherwise

static void c_tcp_destroy ( struct rohc_comp_ctxt *const context ) [static]

Destroy the TCP context.

Parameters:

context The TCP compression context to destroy

static int c_tcp_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/TCP packet according to a pattern decided by several different factors.

1. Check if we have double IP headers.
2. Check if the IP-ID fields are random and if they are in NBO.
3. Decide in which state to go (IR, FO or SO).
4. Decide how many bits are needed to send the IP-ID and SN fields and more important update the sliding windows.
5. Decide which packet type to send.
6. Code the packet.

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 uint8_t* c_tcp_opt_generic	(	struct sc_tcp_context *	tcp_context,
		uint8_t *	ptr,
		uint8_t *	options
	)		`[static]`

Compress a generic TCP option.

See RFC4996 page 67

Parameters:

tcp_context	The specific TCP context
ptr	Pointer where to compress the option
options	Pointer to the TCP option to compress

Returns:: Pointer after the compressed value

static uint8_t * c_tcp_opt_sack	(	const struct rohc_comp_ctxt *const	context,
		uint8_t *	ptr,
		uint32_t	ack_value,
		uint8_t	length,
		const sack_block_t *const	sack_block
	)		`[static]`

Compress the SACK TCP option.

See RFC6846 page 68 (and RFC2018 for Selective Acknowledgement option)

Parameters:

context	The compression context
ptr	Pointer to the compressed value
ack_value	The ack value
length	The length of the sack block
sack_block	Pointer to the first SACK block to compress

Returns:: Pointer after the compressed value

static bool c_ts_lsb	(	const struct rohc_comp_ctxt *const	context,
		uint8_t **	dest,
		const uint32_t	timestamp,
		const size_t	nr_bits_minus_1,
		const size_t	nr_bits_0x40000
	)		`[static]`

Compress the TimeStamp option value.

See RFC4996 page 65

Parameters:

	context	The compression context
[out]	dest	Pointer to the compressed value
	timestamp	The timestamp value to compress
	nr_bits_minus_1	The minimal number of required bits for p = -1
	nr_bits_0x40000	The minimal number of required bits for p = 0x40000

Returns:: true if compression was successful, false otherwise

static int co_baseheader	(	struct rohc_comp_ctxt *const	context,
		struct sc_tcp_context *const	tcp_context,
		ip_context_ptr_t	ip_context,
		base_header_ip_t	base_header,
		unsigned char *const	rohc_pkt,
		const size_t	rohc_pkt_max_len,
		const rohc_packet_t	packet_type,
		const tcphdr_t *const	tcp,
		const uint8_t	crc
	)		`[static]`

Compress the innermost IP header AND the TCP header.

See RFC4996 page 77

Parameters:

context	The compression context
tcp_context	The specific TCP context
ip_context	The specific IP innermost context
base_header	The innermost IP header
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
tcp	The TCP header to compress
crc	The CRC on the uncompressed headers

Returns:: The position in the rohc-packet-under-build buffer -1 in case of problem

static int code_CO_packet	(	struct rohc_comp_ctxt *const	context,
		const struct ip_packet *	ip,
		const int	packet_size,
		const unsigned char *	next_header,
		unsigned char *const	rohc_pkt,
		const size_t	rohc_pkt_max_len,
		const rohc_packet_t	packet_type,
		size_t *const	payload_offset
	)		`[static]`

Build the CO packet.

See RFC4996 page 46


 CO packet (RFC4996 §7.3 page 41):

      0   1   2   3   4   5   6   7
     --- --- --- --- --- --- --- ---
 1  :         Add-CID octet         :  if for small CIDs and CID != 0
    +---+---+---+---+---+---+---+---+
 2  |   First octet of base header  |  (with type indication)
    +---+---+---+---+---+---+---+---+
    |                               |
 3  /    0-2 octets of CID info     /  1-2 octets if for large CIDs
    |                               |
    +---+---+---+---+---+---+---+---+
 4  /   Remainder of base header    /  variable number of octets
    +---+---+---+---+---+---+---+---+
    :        Irregular chain        :
 5  /   (including irregular chain  /  variable
    :    items for TCP options)     :
    +---+---+---+---+---+---+---+---+
    |                               |
 6  /           Payload             /  variable length
    |                               |
     - - - - - - - - - - - - - - - -

Parameters:

context	The compression context
ip	The outer IP header
packet_size	The length of the uncompressed packet (in bytes)
next_header	The next header data used to code the static and dynamic parts of the next header for some profiles such as UDP, UDP-Lite, and so on.
rohc_pkt	OUT: The ROHC packet
rohc_pkt_max_len	The maximum length of the ROHC packet
packet_type	The type of ROHC packet to create
payload_offset	OUT: The offset for the payload in the IP packet

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

static uint8_t * tcp_code_dynamic_ip_part	(	const struct rohc_comp_ctxt *	context,
		ip_context_ptr_t	ip_context,
		base_header_ip_t	base_header,
		multi_ptr_t	mptr,
		int	is_innermost
	)		`[static]`

Build the dynamic part of the IP header.

Parameters:

context	The compression context
ip_context	The specific IP compression context
base_header	The IP header
mptr	The current pointer in the rohc-packet-under-build buffer
is_innermost	True if the IP header is the innermost of the packet

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

static uint8_t * tcp_code_dynamic_ipv6_option_part	(	struct rohc_comp_ctxt *const	context,
		ip_context_ptr_t	ip_context,
		multi_ptr_t	mptr,
		uint8_t	protocol,
		base_header_ip_t	base_header
	)		`[static]`

Build the dynamic part of the IPv6 option header.

Parameters:

context	The compression context
ip_context	The specific IP compression context
mptr	The current pointer in the rohc-packet-under-build buffer
protocol	The IPv6 protocol option
base_header	The IP header

Returns:: The new pointer in the rohc-packet-under-build buffer, NULL if a problem occurs

static uint8_t * tcp_code_dynamic_tcp_part	(	const struct rohc_comp_ctxt *	context,
		const unsigned char *	next_header,
		multi_ptr_t	mptr
	)		`[static]`

Build the dynamic part of the TCP header.


 Dynamic part of TCP header:

TODO

Parameters:

context	The compression context
next_header	The TCP header
mptr	The current pointer in the rohc-packet-under-build buffer

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

static uint8_t * tcp_code_irregular_ip_part	(	struct rohc_comp_ctxt *const	context,
		ip_context_ptr_t	ip_context,
		base_header_ip_t	base_header,
		uint8_t *	rohc_data,
		int	ecn_used,
		int	is_innermost,
		int	ttl_irregular_chain_flag,
		int	ip_inner_ecn
	)		`[static]`

Build the irregular part of the IP header.

See Rfc4996 page 63

Parameters:

context	The compression context
ip_context	The specific IP compression context
base_header	The IP header
rohc_data	The current pointer in the rohc-packet-under-build buffer
ecn_used	The indicator of ECN usage
is_innermost	True if IP header is the innermost of the packet
ttl_irregular_chain_flag	Whether he TTL/Hop Limit of an outer header changed
ip_inner_ecn	The ECN flags of the IP innermost header

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

static uint8_t * tcp_code_irregular_ipv6_option_part	(	struct rohc_comp_ctxt *const	context,
		ip_context_ptr_t	ip_context,
		multi_ptr_t	mptr,
		uint8_t	protocol,
		base_header_ip_t	base_header
	)		`[static]`

Build the irregular part of the IPv6 option header.

Parameters:

context	The compression context
ip_context	The specific IP compression context
mptr	The current pointer in the rohc-packet-under-build buffer
protocol	The IPv6 protocol option
base_header	The IP header

Returns:: The new pointer in the rohc-packet-under-build buffer, NULL if a problem occurs

static uint8_t * tcp_code_irregular_tcp_part	(	struct rohc_comp_ctxt *const	context,
		tcphdr_t *	tcp,
		uint8_t *const	rohc_data,
		int	ip_inner_ecn
	)		`[static]`

Build the irregular part of the TCP header.

Parameters:

context	The compression context
tcp	The TCP header
rohc_data	The current pointer in the rohc-packet-under-build buffer
ip_inner_ecn	The ecn flags of the ip inner

Returns:: The new pointer in the rohc-packet-under-build buffer, NULL in case of problem

static uint8_t * tcp_code_static_ip_part	(	struct rohc_comp_ctxt *const	context,
		base_header_ip_t	base_header,
		multi_ptr_t	mptr
	)		`[static]`

Build the static part of the IP header.

Parameters:

context	The compression context
base_header	The IP header
mptr	The current pointer in the rohc-packet-under-build buffer

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

static uint8_t * tcp_code_static_ipv6_option_part	(	struct rohc_comp_ctxt *const	context,
		multi_ptr_t	mptr,
		uint8_t	protocol,
		base_header_ip_t	base_header
	)		`[static]`

Build the static part of the IPv6 option header.

Parameters:

context	The compression context
mptr	The current pointer in the rohc-packet-under-build buffer
protocol	The IPv6 protocol option
base_header	The IP header

Returns:: The new pointer in the rohc-packet-under-build buffer, NULL if a problem occurs

static uint8_t * tcp_code_static_tcp_part	(	const struct rohc_comp_ctxt *	context,
		const tcphdr_t *	tcp,
		multi_ptr_t	mptr
	)		`[static]`

Build the static part of the TCP header.


 Static part of TCP header:

    +---+---+---+---+---+---+---+---+
 1  /  Source port                  /   2 octets
    +---+---+---+---+---+---+---+---+
 2  /  Destination port             /   2 octets
    +---+---+---+---+---+---+---+---+

Parameters:

context	The compression context
tcp	The TCP header
mptr	The current pointer in the rohc-packet-under-build buffer

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

static bool tcp_compress_tcp_options	(	struct rohc_comp_ctxt *const	context,
		const tcphdr_t *const	tcp,
		uint8_t *const	comp_opts,
		size_t *const	comp_opts_len
	)		`[static]`

Compress the TCP options.

Parameters:

context	The compression context
tcp	The TCP header
comp_opts	IN/OUT: The compressed TCP options
comp_opts_len	OUT: The length (in bytes) of the compressed TCP options

Returns:: true if the TCP options were successfully compressed, false otherwise

static rohc_packet_t tcp_decide_packet	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t *const	ip_inner_context,
		const tcphdr_t *const	tcp
	)		`[static]`

Decide which packet to send when in the different states.

Parameters:

context	The compression context
ip_inner_context	The context of the inner IP header
tcp	The TCP header to compress

Returns:

The packet type among ROHC_PACKET_IR, ROHC_PACKET_IR_DYN, ROHC_PACKET_TCP_RND_[1-8], ROHC_PACKET_TCP_SEQ_[1-8] and ROHC_PACKET_TCP_CO_COMMON in case of success
ROHC_PACKET_UNKNOWN in case of failure

static rohc_packet_t tcp_decide_SO_packet	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_ptr_t *const	ip_inner_context,
		const tcphdr_t *const	tcp
	)		`[static]`

Decide which packet to send when in SO state.

Parameters:

context	The compression context
ip_inner_context	The context of the inner IP header
tcp	The TCP header to compress

Returns:

The packet type among ROHC_PACKET_IR, ROHC_PACKET_IR_DYN, ROHC_PACKET_TCP_RND_[1-8], ROHC_PACKET_TCP_SEQ_[1-8] and ROHC_PACKET_TCP_CO_COMMON in case of success
ROHC_PACKET_UNKNOWN in case of failure

static void tcp_decide_state ( struct rohc_comp_ctxt *const context ) [static]

Decide the state that should be used for the next packet.

The three states are:

Initialization and Refresh (IR),
First Order (FO),
Second Order (SO).

Parameters:

context The compression context

static bool tcp_detect_changes	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt
	)		`[static]`

Detect changes between packet and context.

Parameters:

context	The compression context to compare
uncomp_pkt	The uncompressed packet to compare

Returns:: true if changes were successfully detected, false if a problem occurred

static tcp_ip_id_behavior_t tcp_detect_ip_id_behavior	(	const uint16_t	last_ip_id,
		const uint16_t	new_ip_id
	)		`[static]`

Detect the behavior of the IPv4 Identification field.

Parameters:

last_ip_id	The IP-ID value of the previous packet (in HBO)
new_ip_id	The IP-ID value of the current packet (in HBO)

Returns:: The IP-ID behavior among: IP_ID_BEHAVIOR_SEQ, IP_ID_BEHAVIOR_SEQ_SWAP, IP_ID_BEHAVIOR_ZERO, or IP_ID_BEHAVIOR_RAND

static bool tcp_encode_uncomp_fields	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt
	)		`[static]`

Encode uncompressed fields with the corresponding encoding scheme.

Parameters:

context	The compression context
uncomp_pkt	The uncompressed packet to encode

Returns:: true in case of success, false otherwise

static void tcp_field_descr_change	(	const struct rohc_comp_ctxt *const	context,
		const char *const	name,
		const bool	changed
	)		`[static]`

Print a debug trace for the field change.

Parameters:

context	The compression context
name	The name of the field
changed	Whether the field changed or not

static void tcp_field_descr_present	(	const struct rohc_comp_ctxt *const	context,
		const char *const	name,
		const bool	present
	)		`[static]`

Print a debug trace for the field presence.

Parameters:

context	The compression context
name	The name of the field
present	Whether the field is present or not

static char * tcp_ip_id_behavior_get_descr ( const tcp_ip_id_behavior_t behavior ) [static]

Get a string that describes the given IP-ID behavior.

Parameters:

behavior The type of the option to get a description for

Returns:: The description of the option

static char * tcp_opt_get_descr ( const uint8_t opt_type ) [static]

Get a string that describes the given option type.

Parameters:

opt_type The type of the option to get a description for

Returns:: The description of the option

Variable Documentation

struct rohc_comp_profile c_tcp_profile

Initial value:

{
        .id             = ROHC_PROFILE_TCP, 
        .protocol       = ROHC_IPPROTO_TCP, 
        .create         = c_tcp_create,     
        .destroy        = c_tcp_destroy,
        .check_profile  = c_tcp_check_profile,
        .check_context  = c_tcp_check_context,
        .encode         = c_tcp_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 TCP profile as described in the RFC 3095.

int tcp_options_index[TCP_LIST_ITEM_MAP_LEN] [static]

Initial value:

{
        TCP_INDEX_EOL,             
        TCP_INDEX_NOP,             
        TCP_INDEX_MAXSEG,          
        TCP_INDEX_WINDOW,          
        TCP_INDEX_SACK_PERMITTED,  
        TCP_INDEX_SACK,            
        -1,                        
        -1,                        
        TCP_INDEX_TIMESTAMP,       
        -1,                        
        -1,                        
        -1,                        
        -1,                        
        -1,                        
        -1,                        
        -1                         
}

Table of TCP option index, from option Id.

See RFC4996 6.3.4 Return item index of TCP option

Data Structures

Defines

Typedefs

Functions

Variables

Detailed Description

Define Documentation

Typedef Documentation

Function Documentation

Variable Documentation