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authorTom Herbert2015-05-01 11:30:12 -0700
committerDavid S. Miller2015-05-04 00:09:08 -0400
commit50fb799289501c2eab9f43fc9af513027e1e994f (patch)
tree9ba5b2cb65890f0cd95c00f743da1b2bd71722cc /net
parent6a21165480a066a27c1f1dbd32aec581c612ba23 (diff)
net: Add skb_get_hash_perturb
This calls flow_disect and __skb_get_hash to procure a hash for a packet. Input includes a key to initialize jhash. This function does not set skb->hash. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/flow_dissector.c38
1 files changed, 30 insertions, 8 deletions
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 2c35c02a931e..b1df995ef06c 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -267,13 +267,12 @@ static __always_inline void __flow_hash_secret_init(void)
net_get_random_once(&hashrnd, sizeof(hashrnd));
}
-static __always_inline u32 __flow_hash_3words(u32 a, u32 b, u32 c)
+static __always_inline u32 __flow_hash_3words(u32 a, u32 b, u32 c, u32 keyval)
{
- __flow_hash_secret_init();
- return jhash_3words(a, b, c, hashrnd);
+ return jhash_3words(a, b, c, keyval);
}
-static inline u32 __flow_hash_from_keys(struct flow_keys *keys)
+static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
{
u32 hash;
@@ -287,7 +286,8 @@ static inline u32 __flow_hash_from_keys(struct flow_keys *keys)
hash = __flow_hash_3words((__force u32)keys->dst,
(__force u32)keys->src,
- (__force u32)keys->ports);
+ (__force u32)keys->ports,
+ keyval);
if (!hash)
hash = 1;
@@ -296,10 +296,20 @@ static inline u32 __flow_hash_from_keys(struct flow_keys *keys)
u32 flow_hash_from_keys(struct flow_keys *keys)
{
- return __flow_hash_from_keys(keys);
+ __flow_hash_secret_init();
+ return __flow_hash_from_keys(keys, hashrnd);
}
EXPORT_SYMBOL(flow_hash_from_keys);
+static inline u32 ___skb_get_hash(const struct sk_buff *skb,
+ struct flow_keys *keys, u32 keyval)
+{
+ if (!skb_flow_dissect(skb, keys))
+ return 0;
+
+ return __flow_hash_from_keys(keys, keyval);
+}
+
/*
* __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
@@ -309,8 +319,12 @@ EXPORT_SYMBOL(flow_hash_from_keys);
void __skb_get_hash(struct sk_buff *skb)
{
struct flow_keys keys;
+ u32 hash;
- if (!skb_flow_dissect(skb, &keys))
+ __flow_hash_secret_init();
+
+ hash = ___skb_get_hash(skb, &keys, hashrnd);
+ if (!hash)
return;
if (keys.ports)
@@ -318,10 +332,18 @@ void __skb_get_hash(struct sk_buff *skb)
skb->sw_hash = 1;
- skb->hash = __flow_hash_from_keys(&keys);
+ skb->hash = hash;
}
EXPORT_SYMBOL(__skb_get_hash);
+__u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
+{
+ struct flow_keys keys;
+
+ return ___skb_get_hash(skb, &keys, perturb);
+}
+EXPORT_SYMBOL(skb_get_hash_perturb);
+
/*
* Returns a Tx hash based on the given packet descriptor a Tx queues' number
* to be used as a distribution range.