From b58555f1767c9f4e330fcf168e4e753d2d9196e0 Mon Sep 17 00:00:00 2001 From: Christophe Gouault Date: Fri, 29 Aug 2014 16:16:04 +0200 Subject: 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 Signed-off-by: Steffen Klassert --- include/net/netns/xfrm.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/net/netns/xfrm.h') diff --git a/include/net/netns/xfrm.h b/include/net/netns/xfrm.h index 3492434baf88..41902a8103bd 100644 --- a/include/net/netns/xfrm.h +++ b/include/net/netns/xfrm.h @@ -13,6 +13,10 @@ struct ctl_table_header; struct xfrm_policy_hash { struct hlist_head *table; unsigned int hmask; + u8 dbits4; + u8 sbits4; + u8 dbits6; + u8 sbits6; }; struct netns_xfrm { -- cgit v1.2.3