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| author |   Alexander Aring <alex.aring@gmail.com> | 2015-12-09 22:46:31 +0100 |
|---|---|---|
| committer |   Marcel Holtmann <marcel@holtmann.org> | 2015-12-10 12:55:28 +0100 |
| commit | 818f1f3e70dd4c8e6f8d59c617857be0fa0fce7c (patch) | |
| tree | 35a4520f2488a67fa341ee860aa89ff73510fa93 /include | |
| parent | 6lowpan: add debugfs support (diff) | |
| download | linux-dev-818f1f3e70dd4c8e6f8d59c617857be0fa0fce7c.tar.xz linux-dev-818f1f3e70dd4c8e6f8d59c617857be0fa0fce7c.zip | |
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 <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Acked-by: Łukasz Duda <lukasz.duda@nordicsemi.no>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/ipv6.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/include/net/ipv6.h b/include/net/ipv6.h index 9a5c9f013784..6570f379aba2 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -401,6 +401,21 @@ static inline void ipv6_addr_prefix(struct in6_addr *pfx, pfx->s6_addr[o] = addr->s6_addr[o] & (0xff00 >> b); } +static inline void ipv6_addr_prefix_copy(struct in6_addr *addr, + const struct in6_addr *pfx, + int plen) +{ + /* caller must guarantee 0 <= plen <= 128 */ + int o = plen >> 3, + b = plen & 0x7; + + memcpy(addr->s6_addr, pfx, o); + if (b != 0) { + addr->s6_addr[o] &= ~(0xff00 >> b); + addr->s6_addr[o] |= (pfx->s6_addr[o] & (0xff00 >> b)); + } +} + static inline void __ipv6_addr_set_half(__be32 *addr, __be32 wh, __be32 wl) { |