c_tcp_opts_list.h File Reference

Handle the list of TCP options for the TCP ompression profile. More...

#include "rohc_comp_internals.h"
#include "protocols/tcp.h"
#include <stdint.h>
#include <stddef.h>

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Data Structures
struct	c_tcp_opt_ctxt
	The compression context for one TCP option. More...
struct	c_tcp_opts_ctxt_tmp
struct	c_tcp_opts_ctxt
Defines
#define	MAX_TCP_OPT_SIZE   40U
Functions
bool	rohc_comp_tcp_are_options_acceptable (const struct rohc_comp *const comp, const uint8_t *const opts, const size_t data_offset)
	Whether TCP options are acceptable for TCP profile or not.
bool	tcp_detect_options_changes (struct rohc_comp_ctxt *const context, const struct tcphdr *const tcp, struct c_tcp_opts_ctxt *const opts_ctxt, size_t *const opts_len)
	Parse the uncompressed TCP options for changes.
int	c_tcp_code_tcp_opts_list_item (const struct rohc_comp_ctxt *const context, const struct tcphdr *const tcp, const uint16_t msn, const bool is_dynamic_chain, struct c_tcp_opts_ctxt *const opts_ctxt, uint8_t *const comp_opts, const size_t comp_opts_max_len)
	Build the list of TCP options items.
int	c_tcp_code_tcp_opts_irreg (const struct rohc_comp_ctxt *const context, const struct tcphdr *const tcp, const uint16_t msn, struct c_tcp_opts_ctxt *const opts_ctxt, uint8_t *const comp_opts, const size_t comp_opts_max_len)
	Build the list of TCP options for the irregular chain.

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Detailed Description

Handle the list of TCP options for the TCP ompression profile.

Author:

FWX <rohc_team@dialine.fr>

Didier Barvaux <didier@barvaux.org>

Didier Barvaux <didier.barvaux@toulouse.viveris.com>

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Define Documentation

#define MAX_TCP_OPT_SIZE   40U

The maximum size (in bytes) of one TCP option

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Function Documentation

int c_tcp_code_tcp_opts_irreg	(	const struct rohc_comp_ctxt *const	context,
		const struct tcphdr *const	tcp,
		const uint16_t	msn,
		struct c_tcp_opts_ctxt *const	opts_ctxt,
		uint8_t *const	comp_opts,
		const size_t	comp_opts_max_len
	)

Build the list of TCP options for the irregular chain.

All the CO packets contains an irregular chain.

Parameters:

	context	The compression context
	tcp	The TCP header
	msn	The Master Sequence Number (MSN) of the packet to compress
[in,out]	opts_ctxt	The compression context for TCP options
[out]	comp_opts	The compressed TCP options
	comp_opts_max_len	The max remaining length in the ROHC buffer

Returns:

The length (in bytes) of compressed TCP options in case of success, -1 in case of failure

Todo:

TODO: defines 'options profiles' the same way as for decompressor

int c_tcp_code_tcp_opts_list_item	(	const struct rohc_comp_ctxt *const	context,
		const struct tcphdr *const	tcp,
		const uint16_t	msn,
		const bool	is_dynamic_chain,
		struct c_tcp_opts_ctxt *const	opts_ctxt,
		uint8_t *const	comp_opts,
		const size_t	comp_opts_max_len
	)

Build the list of TCP options items.

The list of TCP options is used in the dynamic chain of the IR and IR-DYN packets, but also at the end of the rnd_8, seq_8, and co_common packets.

Parameters:

	context	The compression context
	tcp	The TCP header
	msn	The Master Sequence Number (MSN) of the packet to compress
	is_dynamic_chain	Whether the list of items is for the dynamic chain or not
[in,out]	opts_ctxt	The compression context for TCP options
[out]	comp_opts	The compressed TCP options
	comp_opts_max_len	The max remaining length in the ROHC buffer

Returns:

The length (in bytes) of compressed TCP options in case of success, -1 in case of failure

bool rohc_comp_tcp_are_options_acceptable	(	const struct rohc_comp *const	comp,
		const uint8_t *const	opts,
		const size_t	data_offset
	)

Whether TCP options are acceptable for TCP profile or not.

TCP options are acceptable for the TCP profile if:

• the last TCP option is not truncated,
• well-known TCP options got the expected length (see below),
• no more than ROHC_TCP_OPTS_MAX options are present,
• each TCP options is present only once (except EOL and NOP).

The following well-known TCP options shall have expected lengthes:

• MSS shall be TCP_OLEN_MSS long,
• WS shall be TCP_OLEN_WS long,
• SACK Permitted shall be TCP_OLEN_SACK_PERM long,
• SACK shall be 2 + N * 8 with N in range [1, 4]
• TS shall be TCP_OLEN_TS long.

Parameters:

	comp	The ROHC compressor
	opts	The beginning of the TCP options
	data_offset	The length (in 32-bit words) of the full TCP header

Returns:

true if the TCP options are acceptable, false if they are not

See also:

ROHC_TCP_OPTS_MAX

bool tcp_detect_options_changes	(	struct rohc_comp_ctxt *const	context,
		const struct tcphdr *const	tcp,
		struct c_tcp_opts_ctxt *const	opts_ctxt,
		size_t *const	opts_len
	)

Parse the uncompressed TCP options for changes.

Parameters:

	context	The compression context
	tcp	The TCP header
[in,out]	opts_ctxt	The compression context for TCP options
[out]	opts_len	The length (in bytes) of the TCP options

Returns:

true if the TCP options were successfully parsed and can be compressed, false otherwise