Contexts for 6LoWPAN address compression

Context buffer for stateful 6LoWPAN address compression. More...

Detailed Description

Context buffer for stateful 6LoWPAN address compression.

See also

RFC 6282, section 3.1.2

RFC 6775, section 4.2

Files
file	ctx.h
	Context buffer definitions.

Data Structures
struct	gnrc_sixlowpan_ctx_t
	Entry in the 6LoWPAN context buffer. More...

Macros
#define	GNRC_SIXLOWPAN_CTX_SIZE   (16)
	maximum number of entries in context buffer

Functions
gnrc_sixlowpan_ctx_t *	gnrc_sixlowpan_ctx_lookup_addr (const ipv6_addr_t *addr)
	Gets a context matching the given IPv6 address best with its prefix. More...
gnrc_sixlowpan_ctx_t *	gnrc_sixlowpan_ctx_lookup_id (uint8_t id)
	Gets context by ID. More...
gnrc_sixlowpan_ctx_t *	gnrc_sixlowpan_ctx_update (uint8_t id, const ipv6_addr_t *prefix, uint8_t prefix_len, uint16_t ltime, bool comp)
	Updates (or adds if currently not registered) a context. More...
static void	gnrc_sixlowpan_ctx_remove (uint8_t id)
	Removes context. More...
static bool	gnrc_sixlowpan_ctx_match (const gnrc_sixlowpan_ctx_t *ctx, const ipv6_addr_t *prefix, uint8_t prefix_len)
	Check if a prefix matches a compression context. More...
static bool	gnrc_sixlowpan_ctx_update_6ctx (const ipv6_addr_t *prefix, uint8_t prefix_len, uint32_t valid)
	Create or update a compression context. More...
void	gnrc_sixlowpan_ctx_reset (void)
	Resets the whole context buffer.

Context flags.
Flags to set in gnrc_sixlowpan_ctx_t::flags_id.
#define	GNRC_SIXLOWPAN_CTX_FLAGS_CID_MASK   (0x0f)
	mask for the Context ID.
#define	GNRC_SIXLOWPAN_CTX_FLAGS_COMP   (0x10)
	Use context for compression.

Function Documentation

gnrc_sixlowpan_ctx_lookup_addr()

gnrc_sixlowpan_ctx_t* gnrc_sixlowpan_ctx_lookup_addr

(

const ipv6_addr_t *

addr

)

Gets a context matching the given IPv6 address best with its prefix.

Parameters

[in]

addr

An IPv6 address.

Returns

The context associated with the best prefix for addr.

NULL if there is no such context.

gnrc_sixlowpan_ctx_lookup_id()

gnrc_sixlowpan_ctx_t* gnrc_sixlowpan_ctx_lookup_id

(

uint8_t

id

)

Gets context by ID.

Parameters

[in]

id

A context ID.

Returns

The context associated with id.

NULL if there is no such context.

gnrc_sixlowpan_ctx_match()

static bool gnrc_sixlowpan_ctx_match ( const gnrc_sixlowpan_ctx_t *  ctx, const ipv6_addr_t *  prefix, uint8_t  prefix_len  )

inlinestatic

Check if a prefix matches a compression context.

Parameters

[in]	ctx	The compression context
[in]	prefix	IPv6 prefix
[in]	prefix_len	Length of the IPv6 prefix

Returns

true if the prefix matches the compression context.

Definition at line 139 of file ctx.h.

gnrc_sixlowpan_ctx_remove()

static void gnrc_sixlowpan_ctx_remove ( uint8_t  id )

inlinestatic

Removes context.

Parameters

[in]

id

A context ID.

Definition at line 123 of file ctx.h.

gnrc_sixlowpan_ctx_update()

gnrc_sixlowpan_ctx_t* gnrc_sixlowpan_ctx_update	(	uint8_t	id,
		const ipv6_addr_t *	prefix,
		uint8_t	prefix_len,
		uint16_t	ltime,
		bool	comp
	)

Updates (or adds if currently not registered) a context.

Parameters

[in]	id	The ID for the context. Must be < GNRC_SIXLOWPAN_CTX_SIZE.
[in]	prefix	The prefix for the context.
[in]	prefix_len	Length of prefix in bits. Must be > 0.
[in]	ltime	New lifetime of the context. comp will be implicitly set to false if ltime == 0.
[in]	comp	Use for compression if true, do not use for compression, but still for decompression if false.

Returns

The new context on success.

NULL, on error or on removal.

gnrc_sixlowpan_ctx_update_6ctx()

static bool gnrc_sixlowpan_ctx_update_6ctx ( const ipv6_addr_t *  prefix, uint8_t  prefix_len, uint32_t  valid  )

inlinestatic

Create or update a compression context.

Parameters

[in]	prefix	IPv6 prefix of the compression context
[in]	prefix_len	Length of the IPv6 prefix
[in]	valid	Lifetime of the prefix in seconds

Returns

true if a new compression context was created or an existing context was updated. false if no new context could be added

Definition at line 158 of file ctx.h.