c_tcp.c File Reference

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

#include "rohc_comp_internals.h"
#include "rohc_traces_internal.h"
#include "rohc_utils.h"
#include "rohc_packets.h"
#include "net_pkt.h"
#include "protocols/ip_numbers.h"
#include "protocols/ip.h"
#include "protocols/ipv4.h"
#include "protocols/ipv6.h"
#include "protocols/tcp.h"
#include "schemes/cid.h"
#include "schemes/ip_id_offset.h"
#include "schemes/rfc4996.h"
#include "c_tcp_opts_list.h"
#include "sdvl.h"
#include "crc.h"
#include "rohc_bit_ops.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_generic_option_context
	Define the IPv6 generic 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	ip_option_context_t
struct	ipv6_context
	Define the IPv6 header context. More...
struct	ip_context_t
	Define union of IP contexts. More...
struct	sc_tcp_context
Defines
#define	TRACE_GOTO_CHOICE rohc_comp_debug(context, "Compressed format choice LINE %d", __LINE__ )
Typedefs
typedef struct ipv6_generic_option_context	ipv6_generic_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.
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, uint8_t 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 uint16_t	c_tcp_get_next_msn (const struct rohc_comp_ctxt *const context)
	Determine the MSN value for the next packet.
static bool	rohc_comp_tcp_are_ipv6_exts_acceptable (const struct rohc_comp const comp, uint8_t const next_proto, const uint8_t const exts, const size_t max_exts_len, size_t const exts_len)
	Whether IPv6 extension headers are acceptable for TCP profile or not.
static bool	tcp_detect_changes (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, ip_context_t const ip_inner_ctxt, const struct tcphdr const tcp)
	Detect changes between packet and context.
static bool	tcp_detect_changes_ipv6_exts (struct rohc_comp_ctxt const context, ip_context_t const ip_context, uint8_t const protocol, const uint8_t const exts, const size_t max_exts_len, size_t const exts_nr, size_t const exts_len)
	Detect changes about IPv6 extension headers 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, const struct tcphdr *const tcp)
	Encode uncompressed fields with the corresponding encoding scheme.
static bool	tcp_encode_uncomp_ip_fields (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt)
	Encode uncompressed IP fields with the corresponding encoding scheme.
static bool	tcp_encode_uncomp_tcp_fields (struct rohc_comp_ctxt const context, const struct tcphdr const tcp)
	Encode uncompressed TCP fields with the corresponding encoding scheme.
static rohc_packet_t	tcp_decide_packet (struct rohc_comp_ctxt const context, const ip_context_t const ip_inner_context, const struct tcphdr *const tcp)
	Decide which packet to send when in the different states.
static rohc_packet_t	tcp_decide_FO_packet (const struct rohc_comp_ctxt const context, const ip_context_t const ip_inner_context, const struct tcphdr *const tcp)
	Decide which packet to send when in FO state.
static rohc_packet_t	tcp_decide_SO_packet (const struct rohc_comp_ctxt const context, const ip_context_t const ip_inner_context, const struct tcphdr *const tcp)
	Decide which packet to send when in SO state.
static rohc_packet_t	tcp_decide_FO_SO_packet (const struct rohc_comp_ctxt const context, const ip_context_t const ip_inner_context, const struct tcphdr *const tcp, const bool crc7_at_least)
	Decide which packet to send when in FO or SO state.
static rohc_packet_t	tcp_decide_FO_SO_packet_seq (const struct rohc_comp_ctxt const context, const struct tcphdr const tcp, const bool crc7_at_least)
	Decide which seq packet to send when in FO or SO state.
static rohc_packet_t	tcp_decide_FO_SO_packet_rnd (const struct rohc_comp_ctxt const context, const struct tcphdr const tcp, const bool crc7_at_least)
	Decide which rnd packet to send when in FO or SO state.
static int	tcp_code_static_part (struct rohc_comp_ctxt const context, const struct ip_packet const ip, uint8_t *const rohc_pkt, const size_t rohc_pkt_max_len)
	Code the static part of an IR packet.
static int	tcp_code_static_ipv4_part (const struct rohc_comp_ctxt const context, const struct ipv4_hdr const ipv4, uint8_t *const rohc_data, const size_t rohc_max_len)
	Build the static part of the IPv4 header.
static int	tcp_code_static_ipv6_part (const struct rohc_comp_ctxt const context, const struct ipv6_hdr const ipv6, uint8_t *const rohc_data, const size_t rohc_max_len)
	Build the static part of the IPv6 header.
static int	tcp_code_static_ipv6_opt_part (const struct rohc_comp_ctxt const context, const struct ipv6_opt const ipv6_opt, const uint8_t protocol, uint8_t *const rohc_data, const size_t rohc_max_len)
	Build the static part of the IPv6 option header.
static int	tcp_code_static_tcp_part (const struct rohc_comp_ctxt const context, const struct tcphdr const tcp, uint8_t *const rohc_data, const size_t rohc_max_len)
	Build the static part of the TCP header.
static int	tcp_code_dyn_part (struct rohc_comp_ctxt const context, const struct ip_packet const ip, uint8_t const rohc_pkt, const size_t rohc_pkt_max_len, size_t const parsed_len)
	Code the dynamic part of an IR or IR-DYN packet.
static int	tcp_code_dynamic_ipv4_part (const struct rohc_comp_ctxt const context, ip_context_t const ip_context, const struct ipv4_hdr const ipv4, const bool is_innermost, uint8_t const rohc_data, const size_t rohc_max_len)
	Build the dynamic part of the IPv4 header.
static int	tcp_code_dynamic_ipv6_part (const struct rohc_comp_ctxt const context, ip_context_t const ip_context, const struct ipv6_hdr const ipv6, uint8_t const rohc_data, const size_t rohc_max_len)
	Build the dynamic part of the IPv6 header.
static int	tcp_code_dynamic_ipv6_opt_part (const struct rohc_comp_ctxt const context, const struct ipv6_opt const ipv6_opt, const uint8_t protocol, uint8_t *const rohc_data, const size_t rohc_max_len)
	Build the dynamic part of the IPv6 option header.
static int	tcp_code_dynamic_tcp_part (const struct rohc_comp_ctxt const context, const struct tcphdr const tcp, uint8_t *const rohc_data, const size_t rohc_max_len)
	Build the dynamic part of the TCP header.
static int	tcp_code_irreg_chain (struct rohc_comp_ctxt const context, const struct ip_packet const ip, const uint8_t ip_inner_ecn, const struct tcphdr const tcp, uint8_t const rohc_pkt, const size_t rohc_pkt_max_len)
	Code the irregular chain of one CO packet.
static int	tcp_code_irregular_ipv4_part (const struct rohc_comp_ctxt const context, const ip_context_t const ip_context, const struct ipv4_hdr const ipv4, const bool is_innermost, const bool ecn_used, const uint8_t ip_inner_ecn, const bool ttl_irreg_chain_flag, uint8_t const rohc_data, const size_t rohc_max_len)
	Build the irregular part of the IPv4 header.
static int	tcp_code_irregular_ipv6_part (const struct rohc_comp_ctxt const context, const ip_context_t const ip_context, const struct ipv6_hdr const ipv6, const bool is_innermost, const bool ecn_used, const uint8_t ip_inner_ecn, const bool ttl_irreg_chain_flag, uint8_t const rohc_data, const size_t rohc_max_len)
	Build the irregular part of the IPv6 header.
static int	tcp_code_irregular_ipv6_opt_part (struct rohc_comp_ctxt const context, ip_option_context_t const opt_ctxt, const struct ipv6_opt const ipv6_opt, const uint8_t protocol, uint8_t const rohc_data, const size_t rohc_max_len)
	Build the irregular part of the IPv6 option header.
static int	tcp_code_irregular_tcp_part (const struct rohc_comp_ctxt const context, const struct tcphdr const tcp, const uint8_t ip_inner_ecn, uint8_t *const rohc_data, const size_t rohc_max_len)
	Build the irregular part of the TCP header.
static int	code_IR_packet (struct rohc_comp_ctxt const context, const struct ip_packet const ip, uint8_t const rohc_pkt, const size_t rohc_pkt_max_len, const rohc_packet_t packet_type, size_t const payload_offset)
	Encode an IP/TCP packet as IR or IR-DYN packet.
static int	code_CO_packet (struct rohc_comp_ctxt const context, const struct ip_packet ip, uint8_t 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_t const inner_ip_ctxt, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, uint8_t const rohc_pkt, const size_t rohc_pkt_max_len, const rohc_packet_t packet_type, const struct tcphdr const tcp, const uint8_t crc)
	Compress the innermost IP header AND the TCP header.
static int	c_tcp_build_rnd_1 (const struct rohc_comp_ctxt const context, const struct sc_tcp_context const tcp_context, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP rnd_1 packet.
static int	c_tcp_build_rnd_2 (const struct rohc_comp_ctxt const context, const struct sc_tcp_context const tcp_context, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP rnd_2 packet.
static int	c_tcp_build_rnd_3 (const struct rohc_comp_ctxt const context, const struct sc_tcp_context const tcp_context, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP rnd_3 packet.
static int	c_tcp_build_rnd_4 (const struct rohc_comp_ctxt const context, const struct sc_tcp_context const tcp_context, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP rnd_4 packet.
static int	c_tcp_build_rnd_5 (const struct rohc_comp_ctxt const context, const struct sc_tcp_context const tcp_context, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP rnd_5 packet.
static int	c_tcp_build_rnd_6 (const struct rohc_comp_ctxt const context, const struct sc_tcp_context const tcp_context, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP rnd_6 packet.
static int	c_tcp_build_rnd_7 (const struct rohc_comp_ctxt const context, const struct sc_tcp_context const tcp_context, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP rnd_7 packet.
static int	c_tcp_build_rnd_8 (const struct rohc_comp_ctxt const context, const ip_context_t const inner_ip_ctxt, struct sc_tcp_context const tcp_context, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP rnd_8 packet.
static int	c_tcp_build_seq_1 (const struct rohc_comp_ctxt const context, const ip_context_t const inner_ip_ctxt, const struct sc_tcp_context const tcp_context, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP seq_1 packet.
static int	c_tcp_build_seq_2 (const struct rohc_comp_ctxt const context, const ip_context_t const inner_ip_ctxt, const struct sc_tcp_context const tcp_context, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP seq_2 packet.
static int	c_tcp_build_seq_3 (const struct rohc_comp_ctxt const context, const ip_context_t const inner_ip_ctxt, const struct sc_tcp_context const tcp_context, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP seq_3 packet.
static int	c_tcp_build_seq_4 (const struct rohc_comp_ctxt const context, const ip_context_t const inner_ip_ctxt, const struct sc_tcp_context const tcp_context, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP seq_4 packet.
static int	c_tcp_build_seq_5 (const struct rohc_comp_ctxt const context, const ip_context_t const inner_ip_ctxt, const struct sc_tcp_context const tcp_context, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP seq_5 packet.
static int	c_tcp_build_seq_6 (const struct rohc_comp_ctxt const context, const ip_context_t const inner_ip_ctxt, const struct sc_tcp_context const tcp_context, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP seq_6 packet.
static int	c_tcp_build_seq_7 (const struct rohc_comp_ctxt const context, const ip_context_t const inner_ip_ctxt, const struct sc_tcp_context const tcp_context, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP seq_7 packet.
static int	c_tcp_build_seq_8 (const struct rohc_comp_ctxt const context, const ip_context_t const inner_ip_ctxt, struct sc_tcp_context const tcp_context, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP seq_8 packet.
static int	c_tcp_build_co_common (const struct rohc_comp_ctxt const context, const ip_context_t const inner_ip_ctxt, struct sc_tcp_context const tcp_context, const struct ip_hdr const inner_ip_hdr, const size_t inner_ip_hdr_len, const struct tcphdr const tcp, const uint8_t crc, uint8_t const rohc_data, const size_t rohc_max_len)
	Build a TCP co_common packet.
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_detect_ecn_used_behavior (struct rohc_comp_ctxt *const context, const uint8_t pkt_ecn_vals, const uint8_t pkt_outer_dscp_changed, const uint8_t pkt_res_val)
	Detect the behavior of the IP/TCP ECN flags and TCP RES flags.
static void	tcp_field_descr_change (const struct rohc_comp_ctxt const context, const char const name, const bool changed, const size_t nr_trans)
	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 bool	tcp_is_ack_scaled_possible (const uint16_t ack_stride, const size_t nr_trans)
	Whether the ACK number may be transmitted scaled or not.
static bool	tcp_is_ack_stride_static (const uint16_t ack_stride, const size_t nr_trans)
	Whether the ack_stride scaling factor shall be transmitted or not.
static bool	c_tcp_feedback (struct rohc_comp_ctxt const context, const enum rohc_feedback_type feedback_type, const uint8_t const packet, const size_t packet_len, const uint8_t *const feedback_data, const size_t feedback_data_len)
	Update the profile when feedback is received.
static bool	c_tcp_feedback_2 (struct rohc_comp_ctxt const context, const uint8_t const packet, const size_t packet_len, const uint8_t *const feedback_data, const size_t feedback_data_len)
	Update the profile when FEEDBACK-2 is received.
static void	c_tcp_feedback_ack (struct rohc_comp_ctxt *const context, const uint32_t sn_bits, const size_t sn_bits_nr, const bool sn_not_valid)
	Perform the required actions after the reception of a positive ACK.
Variables
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 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_context ipv6_context_t

Define the IPv6 header context.

typedef struct ipv6_generic_option_context ipv6_generic_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 int c_tcp_build_co_common	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	inner_ip_ctxt,
		struct sc_tcp_context *const	tcp_context,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build a TCP co_common packet.

Parameters:

	context	The compression context
	inner_ip_ctxt	The specific IP text
	tcp_context	The specific TCP context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of the innermost IP header
	tcp	The TCP header to compress
	crc	The CRC on the uncompressed headers
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

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

static int c_tcp_build_rnd_1	(	const struct rohc_comp_ctxt *const	context,
		const struct sc_tcp_context *const	tcp_context,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[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
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_rnd_2	(	const struct rohc_comp_ctxt *const	context,
		const struct sc_tcp_context *const	tcp_context,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[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
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_rnd_3	(	const struct rohc_comp_ctxt *const	context,
		const struct sc_tcp_context *const	tcp_context,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[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
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_rnd_4	(	const struct rohc_comp_ctxt *const	context,
		const struct sc_tcp_context *const	tcp_context,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[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
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_rnd_5	(	const struct rohc_comp_ctxt *const	context,
		const struct sc_tcp_context *const	tcp_context,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[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
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_rnd_6	(	const struct rohc_comp_ctxt *const	context,
		const struct sc_tcp_context *const	tcp_context,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[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
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_rnd_7	(	const struct rohc_comp_ctxt *const	context,
		const struct sc_tcp_context *const	tcp_context,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[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
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_rnd_8	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	inner_ip_ctxt,
		struct sc_tcp_context *const	tcp_context,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_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
	inner_ip_ctxt	The specific IP innermost context
	tcp_context	The specific TCP context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of the innermost IP header
	tcp	The TCP header to compress
	crc	The CRC on the uncompressed headers
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_seq_1	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	inner_ip_ctxt,
		const struct sc_tcp_context *const	tcp_context,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build a TCP seq_1 packet.

Send LSBs of sequence number See RFC4996 page 83

Parameters:

	context	The compression context
	inner_ip_ctxt	The specific IP innermost context
	tcp_context	The specific TCP context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of the innermost IP header
	tcp	The TCP header to compress
	crc	The CRC on the uncompressed headers
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_seq_2	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	inner_ip_ctxt,
		const struct sc_tcp_context *const	tcp_context,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build a TCP seq_2 packet.

Send scaled sequence number LSBs See RFC4996 page 83

Parameters:

	context	The compression context
	inner_ip_ctxt	The specific IP innermost context
	tcp_context	The specific TCP context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of the innermost IP header
	tcp	The TCP header to compress
	crc	The CRC on the uncompressed headers
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_seq_3	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	inner_ip_ctxt,
		const struct sc_tcp_context *const	tcp_context,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build a TCP seq_3 packet.

Send acknowledgment number LSBs See RFC4996 page 83

Parameters:

	context	The compression context
	inner_ip_ctxt	The specific IP innermost context
	tcp_context	The specific TCP context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of the innermost IP header
	tcp	The TCP header to compress
	crc	The CRC on the uncompressed headers
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_seq_4	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	inner_ip_ctxt,
		const struct sc_tcp_context *const	tcp_context,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build a TCP seq_4 packet.

Send scaled acknowledgment number scaled See RFC4996 page 84

Parameters:

	context	The compression context
	inner_ip_ctxt	The specific IP innermost context
	tcp_context	The specific TCP context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of the innermost IP header
	tcp	The TCP header to compress
	crc	The CRC on the uncompressed headers
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_seq_5	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	inner_ip_ctxt,
		const struct sc_tcp_context *const	tcp_context,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build a TCP seq_5 packet.

Send ACK and sequence number See RFC4996 page 84

Parameters:

	context	The compression context
	inner_ip_ctxt	The specific IP innermost context
	tcp_context	The specific TCP context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of the innermost IP header
	tcp	The TCP header to compress
	crc	The CRC on the uncompressed headers
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_seq_6	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	inner_ip_ctxt,
		const struct sc_tcp_context *const	tcp_context,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build a TCP seq_6 packet.

See RFC4996 page 84

Parameters:

	context	The compression context
	inner_ip_ctxt	The specific IP innermost context
	tcp_context	The specific TCP context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of the innermost IP header
	tcp	The TCP header to compress
	crc	The CRC on the uncompressed headers
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_seq_7	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	inner_ip_ctxt,
		const struct sc_tcp_context *const	tcp_context,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build a TCP seq_7 packet.

Send ACK and window See RFC4996 page 85

Parameters:

	context	The compression context
	inner_ip_ctxt	The specific IP innermost context
	tcp_context	The specific TCP context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of the innermost IP header
	tcp	The TCP header to compress
	crc	The CRC on the uncompressed headers
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int c_tcp_build_seq_8	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	inner_ip_ctxt,
		struct sc_tcp_context *const	tcp_context,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		const struct tcphdr *const	tcp,
		const uint8_t	crc,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_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
	inner_ip_ctxt	The specific IP innermost context
	tcp_context	The specific TCP context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of the innermost IP header
	tcp	The TCP header to compress
	crc	The CRC on the uncompressed headers
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

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

Todo:: TODO: the code that parses IP headers in IP/UDP/RTP profiles could probably be re-used (and maybe enhanced if needed)

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

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

Todo:: TODO: the code that parses IP headers in IP/UDP/RTP profiles could probably be re-used (and maybe enhanced if needed)

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,
		uint8_t *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

Todo:: TODO: the code that parses IP headers in IP/UDP/RTP profiles could probably be re-used (and maybe enhanced if needed)

static bool c_tcp_feedback	(	struct rohc_comp_ctxt *const	context,
		const enum rohc_feedback_type	feedback_type,
		const uint8_t *const	packet,
		const size_t	packet_len,
		const uint8_t *const	feedback_data,
		const size_t	feedback_data_len
	)			`[static]`

Update the profile when feedback is received.

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

Parameters:

	context	The compression context
	feedback_type	The feedback type
	packet	The whole feedback packet with CID bits
	packet_len	The length of the whole feedback packet with CID bits
	feedback_data	The feedback data without the CID bits
	feedback_data_len	The length of the feedback data without the CID bits

Returns:: true if the feedback was successfully handled, false if the feedback could not be taken into account

static bool c_tcp_feedback_2	(	struct rohc_comp_ctxt *const	context,
		const uint8_t *const	packet,
		const size_t	packet_len,
		const uint8_t *const	feedback_data,
		const size_t	feedback_data_len
	)			`[static]`

Update the profile when FEEDBACK-2 is received.

Parameters:

	context	The compression context
	packet	The whole feedback packet with CID bits
	packet_len	The length of the whole feedback packet with CID bits
	feedback_data	The feedback data without the CID bits
	feedback_data_len	The length of the feedback data without the CID bits

Returns:: true if the feedback was successfully handled, false if the feedback could not be taken into account

static void c_tcp_feedback_ack	(	struct rohc_comp_ctxt *const	context,
		const uint32_t	sn_bits,
		const size_t	sn_bits_nr,
		const bool	sn_not_valid
	)			`[static]`

Perform the required actions after the reception of a positive ACK.

Parameters:

	context	The compression context that received a positive ACK
	sn_bits	The LSB bits of the acknowledged SN
	sn_bits_nr	The number of LSB bits of the acknowledged SN
	sn_not_valid	Whether the received SN may be considered as valid or not

static uint16_t c_tcp_get_next_msn ( const struct rohc_comp_ctxt *const context ) [static]

Determine the MSN value for the next packet.

Profile MSN is an internal increasing 16-bit number. See RFC 6846, §6.1.1.

Parameters:

context

The compression context

Returns:: The MSN value for the next ROHC packet

static int co_baseheader	(	struct rohc_comp_ctxt *const	context,
		struct sc_tcp_context *const	tcp_context,
		ip_context_t *const	inner_ip_ctxt,
		const struct ip_hdr *const	inner_ip_hdr,
		const size_t	inner_ip_hdr_len,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len,
		const rohc_packet_t	packet_type,
		const struct tcphdr *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
	inner_ip_ctxt	The specific IP innermost context
	inner_ip_hdr	The innermost IP header
	inner_ip_hdr_len	The length of 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,
		uint8_t *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
	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 int code_IR_packet	(	struct rohc_comp_ctxt *const	context,
		const struct ip_packet *const	ip,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len,
		const rohc_packet_t	packet_type,
		size_t *const	payload_offset
	)			`[static]`

Encode an IP/TCP packet as IR or IR-DYN packet.

Parameters:

	context	The compression context
	ip	The outer IP header
	rohc_pkt	OUT: The ROHC packet
	rohc_pkt_max_len	The maximum length of the ROHC packet
	packet_type	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 bool rohc_comp_tcp_are_ipv6_exts_acceptable	(	const struct rohc_comp *const	comp,
		uint8_t *const	next_proto,
		const uint8_t *const	exts,
		const size_t	max_exts_len,
		size_t *const	exts_len
	)			`[static]`

Whether IPv6 extension headers are acceptable for TCP profile or not.

TCP options are acceptable if:

the last IPv6 extension header is not truncated,
no more than ROHC_TCP_MAX_IP_EXT_HDRS extension headers are present,
each extension header is present only once (except Destination that may occur twice).

Parameters:

	comp	The ROHC compressor
`[in,out]`	next_proto	in: the protocol type of the first extension header out: the protocol type of the transport header
	exts	The beginning of the IPv6 extension headers
	max_exts_len	The maximum length (in bytes) of the extension headers
`[out]`	exts_len	The length (in bytes) of the IPv6 extension headers

Returns:: true if the IPv6 extension headers are acceptable, false if they are not

See also:: ROHC_TCP_MAX_IP_EXT_HDRS

static int tcp_code_dyn_part	(	struct rohc_comp_ctxt *const	context,
		const struct ip_packet *const	ip,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len,
		size_t *const	parsed_len
	)			`[static]`

Code the dynamic part of an IR or IR-DYN packet.

Parameters:

	context	The compression context
	ip	The outer IP header
	rohc_pkt	OUT: The ROHC packet
	rohc_pkt_max_len	The maximum length of the ROHC packet
`[out]`	parsed_len	The length of uncompressed data parsed

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

static int tcp_code_dynamic_ipv4_part	(	const struct rohc_comp_ctxt *const	context,
		ip_context_t *const	ip_context,
		const struct ipv4_hdr *const	ipv4,
		const bool	is_innermost,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build the dynamic part of the IPv4 header.

Parameters:

	context	The compression context
	ip_context	The specific IP compression context
	ipv4	The IPv4 header
	is_innermost	true if the IP header is the innermost of the packet, false otherwise
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int tcp_code_dynamic_ipv6_opt_part	(	const struct rohc_comp_ctxt *const	context,
		const struct ipv6_opt *const	ipv6_opt,
		const uint8_t	protocol,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build the dynamic part of the IPv6 option header.

Parameters:

	context	The compression context
	ipv6_opt	The IPv6 extension header
	protocol	The protocol of the IPv6 extension header
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int tcp_code_dynamic_ipv6_part	(	const struct rohc_comp_ctxt *const	context,
		ip_context_t *const	ip_context,
		const struct ipv6_hdr *const	ipv6,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build the dynamic part of the IPv6 header.

Parameters:

	context	The compression context
	ip_context	The specific IP compression context
	ipv6	The IPv6 header
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int tcp_code_dynamic_tcp_part	(	const struct rohc_comp_ctxt *const	context,
		const struct tcphdr *const	tcp,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build the dynamic part of the TCP header.


 Dynamic part of TCP header:

TODO

Parameters:

	context	The compression context
	tcp	The TCP header
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int tcp_code_irreg_chain	(	struct rohc_comp_ctxt *const	context,
		const struct ip_packet *const	ip,
		const uint8_t	ip_inner_ecn,
		const struct tcphdr *const	tcp,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)			`[static]`

Code the irregular chain of one CO packet.

Parameters:

	context	The compression context
	ip	The outer IP header
	ip_inner_ecn	The ECN flags of the innermost IP header
	tcp	The uncompressed TCP header
	rohc_pkt	OUT: The ROHC packet
	rohc_pkt_max_len	The maximum length of the ROHC packet

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

static int tcp_code_irregular_ipv4_part	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	ip_context,
		const struct ipv4_hdr *const	ipv4,
		const bool	is_innermost,
		const bool	ecn_used,
		const uint8_t	ip_inner_ecn,
		const bool	ttl_irreg_chain_flag,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build the irregular part of the IPv4 header.

See RFC 4996 page 63

Parameters:

	context	The compression context
	ip_context	The specific IP compression context
	ipv4	The IPv4 header
	is_innermost	True if IP header is the innermost of the packet
	ecn_used	The indicator of ECN usage
	ip_inner_ecn	The ECN flags of the IP innermost header
	ttl_irreg_chain_flag	Whether the TTL of an outer header changed
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int tcp_code_irregular_ipv6_opt_part	(	struct rohc_comp_ctxt *const	context,
		ip_option_context_t *const	opt_ctxt,
		const struct ipv6_opt *const	ipv6_opt,
		const uint8_t	protocol,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build the irregular part of the IPv6 option header.

Parameters:

	context	The compression context
	opt_ctxt	The compression context of the IPv6 option
	ipv6_opt	The IPv6 extension header
	protocol	The protocol of the IPv6 extension header
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int tcp_code_irregular_ipv6_part	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	ip_context,
		const struct ipv6_hdr *const	ipv6,
		const bool	is_innermost,
		const bool	ecn_used,
		const uint8_t	ip_inner_ecn,
		const bool	ttl_irreg_chain_flag,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build the irregular part of the IPv6 header.

See RFC 4996 page 63

Parameters:

	context	The compression context
	ip_context	The specific IP compression context
	ipv6	The IPv6 header
	is_innermost	True if IP header is the innermost of the packet
	ecn_used	The indicator of ECN usage
	ip_inner_ecn	The ECN flags of the IP innermost header
	ttl_irreg_chain_flag	Whether the TTL of an outer header changed
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

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

Build the irregular part of the TCP header.

Parameters:

	context	The compression context
	tcp	The TCP header
	ip_inner_ecn	The ECN flags of the innermost IP header
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int tcp_code_static_ipv4_part	(	const struct rohc_comp_ctxt *const	context,
		const struct ipv4_hdr *const	ipv4,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build the static part of the IPv4 header.

Parameters:

	context	The compression context
	ipv4	The IPv4 header
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int tcp_code_static_ipv6_opt_part	(	const struct rohc_comp_ctxt *const	context,
		const struct ipv6_opt *const	ipv6_opt,
		const uint8_t	protocol,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build the static part of the IPv6 option header.

Parameters:

	context	The compression context
	ipv6_opt	The IPv6 extension header
	protocol	The protocol of the IPv6 extension header
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int tcp_code_static_ipv6_part	(	const struct rohc_comp_ctxt *const	context,
		const struct ipv6_hdr *const	ipv6,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[static]`

Build the static part of the IPv6 header.

Parameters:

	context	The compression context
	ipv6	The IPv6 header
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static int tcp_code_static_part	(	struct rohc_comp_ctxt *const	context,
		const struct ip_packet *const	ip,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)			`[static]`

Code the static part of an IR packet.

Parameters:

	context	The compression context
	ip	The outer IP header
	rohc_pkt	OUT: The ROHC packet
	rohc_pkt_max_len	The maximum length of the ROHC packet

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

static int tcp_code_static_tcp_part	(	const struct rohc_comp_ctxt *const	context,
		const struct tcphdr *const	tcp,
		uint8_t *const	rohc_data,
		const size_t	rohc_max_len
	)			`[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
`[out]`	rohc_data	The ROHC packet being built
	rohc_max_len	The max remaining length in the ROHC buffer

Returns:: The length appended in the ROHC buffer if positive, -1 in case of error

static rohc_packet_t tcp_decide_FO_packet	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	ip_inner_context,
		const struct tcphdr *const	tcp
	)			`[static]`

Decide which packet to send when in FO 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_8, ROHC_PACKET_TCP_SEQ_8 and ROHC_PACKET_TCP_CO_COMMON in case of success
ROHC_PACKET_UNKNOWN in case of failure

static rohc_packet_t tcp_decide_FO_SO_packet	(	const struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	ip_inner_context,
		const struct tcphdr *const	tcp,
		const bool	crc7_at_least
	)			`[static]`

Decide which packet to send when in FO or SO state.

Parameters:

	context	The compression context
	ip_inner_context	The context of the inner IP header
	tcp	The TCP header to compress
	crc7_at_least	Whether packet types with CRC strictly smaller than 8 bits are allowed or not

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_FO_SO_packet_rnd	(	const struct rohc_comp_ctxt *const	context,
		const struct tcphdr *const	tcp,
		const bool	crc7_at_least
	)			`[static]`

Decide which rnd packet to send when in FO or SO state.

Parameters:

	context	The compression context
	tcp	The TCP header to compress
	crc7_at_least	Whether packet types with CRC strictly smaller than 8 bits are allowed or not

Returns:

The packet type among 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_FO_SO_packet_seq	(	const struct rohc_comp_ctxt *const	context,
		const struct tcphdr *const	tcp,
		const bool	crc7_at_least
	)			`[static]`

Decide which seq packet to send when in FO or SO state.

Parameters:

	context	The compression context
	tcp	The TCP header to compress
	crc7_at_least	Whether packet types with CRC strictly smaller than 8 bits are allowed or not

Returns:

The packet type among 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_packet	(	struct rohc_comp_ctxt *const	context,
		const ip_context_t *const	ip_inner_context,
		const struct tcphdr *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_t *const	ip_inner_context,
		const struct tcphdr *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,
		ip_context_t **const	ip_inner_ctxt,
		const struct tcphdr **const	tcp
	)			`[static]`

Detect changes between packet and context.

Parameters:

	context	The compression context to compare
	uncomp_pkt	The uncompressed packet to compare
`[out]`	ip_inner_ctxt	The context of the inner IP header
`[out]`	tcp	The TCP header found in uncompressed headers

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

static bool tcp_detect_changes_ipv6_exts	(	struct rohc_comp_ctxt *const	context,
		ip_context_t *const	ip_context,
		uint8_t *const	protocol,
		const uint8_t *const	exts,
		const size_t	max_exts_len,
		size_t *const	exts_nr,
		size_t *const	exts_len
	)			`[static]`

Detect changes about IPv6 extension headers between packet and context.

Parameters:

	context	The compression context to compare
	ip_context	The specific IP compression context
`[in,out]`	protocol	in: the protocol type of the first extension header out: the protocol type of the transport header
	exts	The beginning of the IPv6 extension headers
	max_exts_len	The maximum length (in bytes) of the extension headers
`[out]`	exts_nr	The number of IPv6 extension headers
`[out]`	exts_len	The length (in bytes) of the IPv6 extension headers

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

static void tcp_detect_ecn_used_behavior	(	struct rohc_comp_ctxt *const	context,
		const uint8_t	pkt_ecn_vals,
		const uint8_t	pkt_outer_dscp_changed,
		const uint8_t	pkt_res_val
	)			`[static]`

Detect the behavior of the IP/TCP ECN flags and TCP RES flags.

What value for ecn_used? The ecn_used controls the presence of IP ECN flags, TCP ECN flags, but also TCP RES flags.

Parameters:

`[in,out]`	context	The compression context to compare
	pkt_ecn_vals	The values of the IP/ECN flags in the current packet
	pkt_outer_dscp_changed	Whether at least one DSCP changed in the current packet
	pkt_res_val	The TCP RES flags in the current packet

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,
		const struct tcphdr *const	tcp
	)			`[static]`

Encode uncompressed fields with the corresponding encoding scheme.

Parameters:

	context	The compression context
	uncomp_pkt	The uncompressed packet to encode
	tcp	The uncompressed TCP header to encode

Returns:: true in case of success, false otherwise

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

Encode uncompressed IP 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 bool tcp_encode_uncomp_tcp_fields	(	struct rohc_comp_ctxt *const	context,
		const struct tcphdr *const	tcp
	)			`[static]`

Encode uncompressed TCP fields with the corresponding encoding scheme.

Parameters:

	context	The compression context
	tcp	The uncompressed TCP header 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,
		const size_t	nr_trans
	)			`[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
	nr_trans	The number of times the field was transmitted since the last change

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 bool tcp_is_ack_scaled_possible	(	const uint16_t	ack_stride,
		const size_t	nr_trans
	)			`[static]`

Whether the ACK number may be transmitted scaled or not.

The ACK number may be transmitted scaled if:

the ack_stride scaling factor is non-zero,
both the ack_stride scaling factor and the scaling residue didn't change in the last few packets

Parameters:

	ack_stride	The ack_stride scaling factor
	nr_trans	The number of transmissions since last change

Returns:: true if the ACK number may be transmitted scaled, false if the ACK number shall be transmitted unscaled

static bool tcp_is_ack_stride_static	(	const uint16_t	ack_stride,
		const size_t	nr_trans
	)			`[static]`

Whether the ack_stride scaling factor shall be transmitted or not.

Parameters:

	ack_stride	The ack_stride scaling factor
	nr_trans	The number of transmissions since last change

Returns:: true if the ACK number may be transmitted scaled, false if the ACK number shall be transmitted unscaled

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 = rohc_comp_reinit_context,
        .feedback       = c_tcp_feedback,
}

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

c_tcp.c File Reference

Data Structures

Defines

Typedefs

Functions

Variables

Detailed Description

Define Documentation

Typedef Documentation

Function Documentation

Variable Documentation