linux

iv/linux

History

Christophe Gouault b58555f176 xfrm: hash prefixed policies based on preflen thresholds

The idea is an extension of the current policy hashing.

Today only non-prefixed policies are stored in a hash table. This
patch relaxes the constraints, and hashes policies whose prefix
lengths are greater or equal to a configurable threshold.

Each hash table (one per direction) maintains its own set of IPv4 and
IPv6 thresholds (dbits4, sbits4, dbits6, sbits6), by default (32, 32,
128, 128).

Example, if the output hash table is configured with values (16, 24,
56, 64):

ip xfrm policy add dir out src 10.22.0.0/20 dst 10.24.1.0/24 ... => hashed
ip xfrm policy add dir out src 10.22.0.0/16 dst 10.24.1.1/32 ... => hashed
ip xfrm policy add dir out src 10.22.0.0/16 dst 10.24.0.0/16 ... => unhashed

ip xfrm policy add dir out \
    src 3ffe:304:124:2200::/60 dst 3ffe:304:124:2401::/64 ...    => hashed
ip xfrm policy add dir out \
    src 3ffe:304:124:2200::/56 dst 3ffe:304:124:2401::2/128 ...  => hashed
ip xfrm policy add dir out \
    src 3ffe:304:124:2200::/56 dst 3ffe:304:124:2400::/56 ...    => unhashed

The high order bits of the addresses (up to the threshold) are used to
compute the hash key.

Signed-off-by: Christophe Gouault <christophe.gouault@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

2014-09-02 13:29:44 +02:00

Kconfig

net/xfrm: remove depends on CONFIG_EXPERIMENTAL

2013-01-11 11:40:03 -08:00

Makefile

xfrm: make xfrm_algo.c a module

2012-05-15 13:13:34 -04:00

xfrm_algo.c

net: move pskb_put() to core code

2013-11-07 19:28:58 -05:00

xfrm_hash.c

net: allow GFP_HIGHMEM in __vmalloc()