diff options
| author | Tom Herbert <therbert@google.com> | 2014-07-01 21:32:05 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-07-07 21:14:20 -0700 |
| commit | 5ed20a68cd6ca4adc0aa2d240913d604a2eb3e25 (patch) | |
| tree | a1640d40c35cc9f081d18d8d75f1e1759cad92ee | |
| parent | 081a20ffccd24d2f5fd06debcff57697fa2ff069 (diff) | |
| download | linux-5ed20a68cd6ca4adc0aa2d240913d604a2eb3e25.tar.bz2 | |
flow_dissector: Abstract out hash computation
Move the hash computation located in __skb_get_hash to be a separate
function which takes flow_keys as input. This will allow flow hash
computation in other contexts where we only have addresses and ports.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/flow_keys.h | 1 | ||||
| -rw-r--r-- | net/core/flow_dissector.c | 44 |
2 files changed, 29 insertions, 16 deletions
diff --git a/include/net/flow_keys.h b/include/net/flow_keys.h index fbefdca5e283..6667a054763a 100644 --- a/include/net/flow_keys.h +++ b/include/net/flow_keys.h @@ -29,4 +29,5 @@ struct flow_keys { bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow); __be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto); +u32 flow_hash_from_keys(struct flow_keys *keys); #endif diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index c2b53c1b21d2..2ff8cd4dfc5f 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -202,6 +202,33 @@ static __always_inline u32 __flow_hash_1word(u32 a) return jhash_1word(a, hashrnd); } +static inline u32 __flow_hash_from_keys(struct flow_keys *keys) +{ + u32 hash; + + /* get a consistent hash (same value on both flow directions) */ + if (((__force u32)keys->dst < (__force u32)keys->src) || + (((__force u32)keys->dst == (__force u32)keys->src) && + ((__force u16)keys->port16[1] < (__force u16)keys->port16[0]))) { + swap(keys->dst, keys->src); + swap(keys->port16[0], keys->port16[1]); + } + + hash = __flow_hash_3words((__force u32)keys->dst, + (__force u32)keys->src, + (__force u32)keys->ports); + if (!hash) + hash = 1; + + return hash; +} + +u32 flow_hash_from_keys(struct flow_keys *keys) +{ + return __flow_hash_from_keys(keys); +} +EXPORT_SYMBOL(flow_hash_from_keys); + /* * __skb_get_hash: calculate a flow hash based on src/dst addresses * and src/dst port numbers. Sets hash in skb to non-zero hash value @@ -211,7 +238,6 @@ static __always_inline u32 __flow_hash_1word(u32 a) void __skb_get_hash(struct sk_buff *skb) { struct flow_keys keys; - u32 hash; if (!skb_flow_dissect(skb, &keys)) return; @@ -219,21 +245,7 @@ void __skb_get_hash(struct sk_buff *skb) if (keys.ports) skb->l4_hash = 1; - /* get a consistent hash (same value on both flow directions) */ - if (((__force u32)keys.dst < (__force u32)keys.src) || - (((__force u32)keys.dst == (__force u32)keys.src) && - ((__force u16)keys.port16[1] < (__force u16)keys.port16[0]))) { - swap(keys.dst, keys.src); - swap(keys.port16[0], keys.port16[1]); - } - - hash = __flow_hash_3words((__force u32)keys.dst, - (__force u32)keys.src, - (__force u32)keys.ports); - if (!hash) - hash = 1; - - skb->hash = hash; + skb->hash = __flow_hash_from_keys(&keys); } EXPORT_SYMBOL(__skb_get_hash); |