Implementation of IPv6 extension headers More...

Detailed Description

Implementation of IPv6 extension headers

Topics
	GNRC IPv6 extension header compile configurations


	Support for IPv6 fragmentation extension
	GNRC implementation of IPv6 fragmentation extension

	Support for IPv6 option extension headers
	GNRC implementation of IPv6 hop-by-hop and destination option header extension

	Support for IPv6 routing header extension
	GNRC implementation of IPv6 routing header extension.

Files
file	ext.h
	Definititions for IPv6 extension headers.

Functions
gnrc_pktsnip_t *	gnrc_ipv6_ext_build (gnrc_pktsnip_t ipv6, gnrc_pktsnip_t next, uint8_t nh, size_t size)
	Builds an extension header for sending.

gnrc_pktsnip_t *	gnrc_ipv6_ext_process_hopopt (gnrc_pktsnip_t pkt, uint8_t protnum)
	Processes a packet's payload as hop-by-hop option if `protnum` is pointing to a value equal to PROTNUM_IPV6_EXT_HOPOPT.

gnrc_pktsnip_t *	gnrc_ipv6_ext_process_all (gnrc_pktsnip_t pkt, uint8_t protnum)
	Processes a packet's extension headers after a potential initial hop-by-hop header.

Function Documentation

gnrc_pktsnip_t * gnrc_ipv6_ext_build	(	gnrc_pktsnip_t *	ipv6,
		gnrc_pktsnip_t *	next,
		uint8_t	nh,
		size_t	size )

Builds an extension header for sending.

Parameters

[in]	ipv6	The IPv6 header. Can be NULL.
[in]	next	The next header. Must be a successor to `ipv6` if it is not NULL.
[in]	nh	Protocol Numbers of the next header.
[in]	size	Size of the extension header.

gnrc_pktsnip_t * gnrc_ipv6_ext_process_all	(	gnrc_pktsnip_t *	pkt,
		uint8_t *	protnum )

Processes a packet's extension headers after a potential initial hop-by-hop header.

Note: Should be called by IPv6 after gnrc_ipv6_ext_process_hopopt(), i.e. the (first) hop-by-hop option should already be marked in pkt. If a hop-by-hop option is found in gnrc_pktsnip_t::data of pkt, the function will return an error.

Parameters

[in]	pkt	An IPv6 packet in receive order.
[in,out]	protnum	In: The Protocol Numbers of gnrc_pktsnip_t::data of `pkt` (i.e. the first extension header to be processed). Out: The Protocol Numbers of header in gnrc_pktsnip_t::data of `pkt`. The extension headers are now marked, so their data can be found in gnrc_pktsnip_t::next of `pkt` and the following. If the return value is NULL, the value of `protnum` is undefined.

Returns: pkt with all extension headers marked until the first non-extension header.; NULL, if packet was consumed by the extension header handling.; NULL, on error (including if one of the extension headers was a hop-by-hop option). pkt is released with EINVAL in that case.

gnrc_pktsnip_t * gnrc_ipv6_ext_process_hopopt	(	gnrc_pktsnip_t *	pkt,
		uint8_t *	protnum )

Processes a packet's payload as hop-by-hop option if protnum is pointing to a value equal to PROTNUM_IPV6_EXT_HOPOPT.

Note: Should be called by IPv6 before any further processing (even forwarding-related) is done to pkt.

Parameters

[in]	pkt	An IPv6 packet in receive order. It assumed that gnrc_pktsnip_t::data points to a hop-by-hop option when `protnum` points to value equal to PROTNUM_IPV6_EXT_HOPOPT.
[in,out]	protnum	In: The Protocol Numbers of gnrc_pktsnip_t::data of `pkt`. Out: If `protnum` was PROTNUM_IPV6_EXT_HOPOPT on in and the return value is not NULL it points to the value of the next header field of the processed hop-by-hop option header. Since the hop-by-hop option header is now marked, gnrc_pktsnip_t::data of `pkt` will then be identified by `protnum`. If `protnum` was PROTNUM_IPV6_EXT_HOPOPT on in and the return value is NULL the value `protnum` is pointing to is undefined. If `protnum` unequal to PROTNUM_IPV6_EXT_HOPOPT on in the value `protnum` is pointing to remains unchanged.

Returns: pkt with the hop-by-hop option marked on success.; NULL, if the packet was consumed by the option handling.; NULL, on error. pkt is released with EINVAL in that case.