6LoWPAN reassembly buffer

6LoWPAN reassembly buffer More...

Detailed Description

6LoWPAN reassembly buffer

Files
file	rb.h
	Reassembly buffer definitions.

Data Structures
struct	gnrc_sixlowpan_frag_rb_int
	Fragment intervals to identify limits of fragments and duplicates. More...
struct	gnrc_sixlowpan_frag_rb_base_t
	Base class for both reassembly buffer and virtual reassembly buffer. More...
struct	gnrc_sixlowpan_frag_rb_t
	An entry in the 6LoWPAN reassembly buffer. More...

Macros
#define	GNRC_SIXLOWPAN_FRAG_RB_GC_MSG   (0x0226)
	Message type for triggering garbage collection reassembly buffer.

Typedefs
typedef struct gnrc_sixlowpan_frag_rb_int	gnrc_sixlowpan_frag_rb_int_t
	Fragment intervals to identify limits of fragments and duplicates.

Functions
gnrc_sixlowpan_frag_rb_t *	gnrc_sixlowpan_frag_rb_add (gnrc_netif_hdr_t *netif_hdr, gnrc_pktsnip_t *frag, size_t offset, unsigned page)
	Adds a new fragment to the reassembly buffer.
gnrc_sixlowpan_frag_rb_t *	gnrc_sixlowpan_frag_rb_get_by_datagram (const gnrc_netif_hdr_t *netif_hdr, uint16_t tag)
	Gets a reassembly buffer entry with a given link-layer address pair and tag.
bool	gnrc_sixlowpan_frag_rb_exists (const gnrc_netif_hdr_t *netif_hdr, uint16_t tag)
	Checks if a reassembly buffer entry with a given link-layer address pair and tag exists.
void	gnrc_sixlowpan_frag_rb_rm_by_datagram (const gnrc_netif_hdr_t *netif_hdr, uint16_t tag)
	Removes a reassembly buffer entry with a given link-layer address pair and tag.
static bool	gnrc_sixlowpan_frag_rb_entry_empty (const gnrc_sixlowpan_frag_rb_t *rbuf)
	Checks if a reassembly buffer entry is unset.
void	gnrc_sixlowpan_frag_rb_reset (void)
	Resets the packet buffer to a clean state.
const gnrc_sixlowpan_frag_rb_t *	gnrc_sixlowpan_frag_rb_array (void)
	Returns a pointer to the array representing the reassembly buffer.
void	gnrc_sixlowpan_frag_rb_base_rm (gnrc_sixlowpan_frag_rb_base_t *entry)
	Remove base entry.
void	gnrc_sixlowpan_frag_rb_gc (void)
	Garbage collect reassembly buffer.
int	gnrc_sixlowpan_frag_rb_dispatch_when_complete (gnrc_sixlowpan_frag_rb_t *rbuf, gnrc_netif_hdr_t *netif)
	Checks if a reassembly buffer entry is complete and dispatches it to the next layer if that is the case.
static void	gnrc_sixlowpan_frag_rb_remove (gnrc_sixlowpan_frag_rb_t *rbuf)
	Unsets a reassembly buffer entry (but does not free rbuf_t::super::pkt)
bool	gnrc_sixlowpan_frag_rb_ints_empty (void)
	Check if pool of fragment intervals is empty.

Macro Definition Documentation

GNRC_SIXLOWPAN_FRAG_RB_GC_MSG

#define GNRC_SIXLOWPAN_FRAG_RB_GC_MSG   (0x0226)

Message type for triggering garbage collection reassembly buffer.

Definition at line 42 of file rb.h.

Typedef Documentation

gnrc_sixlowpan_frag_rb_int_t

typedef struct gnrc_sixlowpan_frag_rb_int gnrc_sixlowpan_frag_rb_int_t

Fragment intervals to identify limits of fragments and duplicates.

Note

Fragments MUST NOT overlap and overlapping fragments are to be discarded

See also

RFC 4944, section 5.3

Function Documentation

gnrc_sixlowpan_frag_rb_add()

gnrc_sixlowpan_frag_rb_t * gnrc_sixlowpan_frag_rb_add	(	gnrc_netif_hdr_t *	netif_hdr,
		gnrc_pktsnip_t *	frag,
		size_t	offset,
		unsigned	page
	)

Adds a new fragment to the reassembly buffer.

If the packet is complete, dispatch the packet with the transmit information of the last fragment.

Parameters

[in]	netif_hdr	The interface header of the fragment, with gnrc_netif_hdr_t::if_pid and its source and destination address set.
[in]	frag	The fragment to add. Will be released by the function.
[in]	offset	The fragment's offset.
[in]	page	Current 6Lo dispatch parsing page.

Returns

The reassembly buffer entry the fragment was added to on success.

NULL on error.

gnrc_sixlowpan_frag_rb_array()

const gnrc_sixlowpan_frag_rb_t * gnrc_sixlowpan_frag_rb_array

(

void

)

Returns a pointer to the array representing the reassembly buffer.

Note

Only available when TEST_SUITES is defined

Returns

The first element of the reassembly buffer. const, so that write access is immediately spotted at compile time of tests. The const qualifier may however be discarded if required by the tests.

gnrc_sixlowpan_frag_rb_base_rm()

void gnrc_sixlowpan_frag_rb_base_rm

(

gnrc_sixlowpan_frag_rb_base_t *

entry

)

Remove base entry.

Parameters

[in,out]

entry

Entry to remove

gnrc_sixlowpan_frag_rb_dispatch_when_complete()

int gnrc_sixlowpan_frag_rb_dispatch_when_complete	(	gnrc_sixlowpan_frag_rb_t *	rbuf,
		gnrc_netif_hdr_t *	netif
	)

Checks if a reassembly buffer entry is complete and dispatches it to the next layer if that is the case.

Precondition

rbuf != NULL

netif != NULL

Parameters

[in]	rbuf	A reassembly buffer entry. Must not be NULL.
[in]	netif	Original gnrc_netif_hdr_t of the last received frame. Used to construct the gnrc_netif_hdr_t of the completed datagram. Must not be NULL.

Returns

>0, when the datagram in rbuf was complete and dispatched.

0, when the datagram in rbuf is not complete.

-1, if the the reassembled datagram was not dispatched. rbuf is destroyed either way.

gnrc_sixlowpan_frag_rb_entry_empty()

static bool gnrc_sixlowpan_frag_rb_entry_empty ( const gnrc_sixlowpan_frag_rb_t *  rbuf )

inlinestatic

Checks if a reassembly buffer entry is unset.

Parameters

[in]

rbuf

A reassembly buffer entry

Returns

true, if rbuf is empty (i.e. rbuf->super.pkt is NULL).

false, if rbuf is in use.

Definition at line 208 of file rb.h.

gnrc_sixlowpan_frag_rb_exists()

bool gnrc_sixlowpan_frag_rb_exists	(	const gnrc_netif_hdr_t *	netif_hdr,
		uint16_t	tag
	)

Checks if a reassembly buffer entry with a given link-layer address pair and tag exists.

Precondition

netif_hdr != NULL

Parameters

[in]	netif_hdr	An interface header to provide the (source, destination) link-layer address pair. Must not be NULL.
[in]	tag	Tag to search for.

Note

datagram_size is not a search parameter as the primary use case for this function is [Selective Fragment Recovery] (https://tools.ietf.org/html/rfc8931) where this information only exists in the first fragment.

Returns

true, if an entry with the given tuple exist.

false, if no entry with the given tuple exist.

gnrc_sixlowpan_frag_rb_get_by_datagram()

gnrc_sixlowpan_frag_rb_t * gnrc_sixlowpan_frag_rb_get_by_datagram	(	const gnrc_netif_hdr_t *	netif_hdr,
		uint16_t	tag
	)

Gets a reassembly buffer entry with a given link-layer address pair and tag.

Precondition

netif_hdr != NULL

Parameters

[in]	netif_hdr	An interface header to provide the (source, destination) link-layer address pair. Must not be NULL.
[in]	tag	Tag to search for.

Note

datagram_size is not a search parameter as the primary use case for this function is [Selective Fragment Recovery] (https://tools.ietf.org/html/rfc8931) where this information only exists in the first fragment.

Returns

The reassembly buffer entry identified by the source and destination address in the netif_hdr and tag, if any such entry exist.

NULL, if no entry with the given identifying tuple exist.

gnrc_sixlowpan_frag_rb_ints_empty()

bool gnrc_sixlowpan_frag_rb_ints_empty

(

void

)

Check if pool of fragment intervals is empty.

See also

gnrc_sixlowpan_frag_rb_int_t

Note

Returns only non-true values if TEST_SUITES is defined.

Returns

true, if pool of fragment intervals is empty

false, if pool of fragment intervals is not empty

gnrc_sixlowpan_frag_rb_remove()

static void gnrc_sixlowpan_frag_rb_remove ( gnrc_sixlowpan_frag_rb_t *  rbuf )

inlinestatic

Unsets a reassembly buffer entry (but does not free rbuf_t::super::pkt)

Precondition

rbuf != NULL

This functions sets rbuf_t::super::pkt to NULL and removes all rbuf::ints.

Note

Does nothing if module gnrc_sixlowpan_frag_rb is not included.

Parameters

[in]

rbuf

A reassembly buffer entry. Must not be NULL.

Definition at line 278 of file rb.h.

gnrc_sixlowpan_frag_rb_reset()

void gnrc_sixlowpan_frag_rb_reset

(

void

)

Resets the packet buffer to a clean state.

Note

Only available when TEST_SUITES is defined

gnrc_sixlowpan_frag_rb_rm_by_datagram()

void gnrc_sixlowpan_frag_rb_rm_by_datagram	(	const gnrc_netif_hdr_t *	netif_hdr,
		uint16_t	tag
	)

Removes a reassembly buffer entry with a given link-layer address pair and tag.

Precondition

netif_hdr != NULL

Parameters

[in]	netif_hdr	An interface header to provide the (source, destination) link-layer address pair. Must not be NULL.
[in]	tag	Tag to search for.

Note

datagram_size is not a search parameter as the primary use case for this function is [Selective Fragment Recovery] (https://tools.ietf.org/html/rfc8931) where this information only exists in the first fragment.