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

Macros
#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. More...
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. More...
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 rohc_tcp_chain_t chain_type, struct c_tcp_opts_ctxt *const opts_ctxt, uint8_t *const comp_opts, const size_t comp_opts_max_len, bool *const no_item_needed)
	Build the list of TCP options items. More...
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. More...

Detailed Description

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

Author

FWX rohc_.nosp@m.team.nosp@m.@dial.nosp@m.ine..nosp@m.fr

Didier Barvaux didie.nosp@m.r@ba.nosp@m.rvaux.nosp@m..org

Didier Barvaux didie.nosp@m.r.ba.nosp@m.rvaux.nosp@m.@tou.nosp@m.louse.nosp@m..viv.nosp@m.eris..nosp@m.com

Macro Definition Documentation

MAX_TCP_OPT_SIZE

#define MAX_TCP_OPT_SIZE   40U

The maximum size (in bytes) of one TCP option

Function Documentation

c_tcp_code_tcp_opts_irreg()

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

c_tcp_code_tcp_opts_list_item()

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 rohc_tcp_chain_t	chain_type,
		struct c_tcp_opts_ctxt *const	opts_ctxt,
		uint8_t *const	comp_opts,
		const size_t	comp_opts_max_len,
		bool *const	no_item_needed
	)

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,
• the replicate chain of the IR-CR packets,
• 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
	chain_type	The TCP chain for which the list of items is
[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
[out]	no_item_needed	Whether no item was needed at all

Returns

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

rohc_comp_tcp_are_options_acceptable()

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

tcp_detect_options_changes()

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