ipv6: add ipv6_addr_prefix_copy

This patch adds a static inline function ipv6_addr_prefix_copy which
copies a ipv6 address prefix(argument pfx) into the ipv6 address prefix.
The prefix len is given by plen as bits. This function mainly based on
ipv6_addr_prefix which copies one address prefix from address into a new
ipv6 address destination and zero all other address bits.

The difference is that ipv6_addr_prefix_copy don't get a prefix from an
ipv6 address, it sets a prefix to an ipv6 address with keeping other
address bits. The use case is for context based address compression
inside 6LoWPAN IPHC header which keeping ipv6 prefixes inside a context
table to lookup address-bits without sending them.

Cc: Alexey Kuznetsov <[email protected]>
Cc: James Morris <[email protected]>
Cc: Hideaki YOSHIFUJI <[email protected]>
Cc: Patrick McHardy <[email protected]>
Acked-by: Łukasz Duda <[email protected]>
Acked-by: Hannes Frederic Sowa <[email protected]>
Acked-by: YOSHIFUJI Hideaki <[email protected]>
Acked-by: David S. Miller <[email protected]>
Reviewed-by: Stefan Schmidt <[email protected]>
Signed-off-by: Alexander Aring <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>

0 files changed, 0 insertions, 0 deletions