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author | Tom Herbert <tom@herbertland.com> | 2015-05-01 11:30:17 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2015-05-04 00:09:09 -0400 |
commit | 2f59e1ebaa7f762c8825871b5486b5f5b4fa952f (patch) | |
tree | 431a21930a7976182e62c7db270b69d564041b82 /net/core/flow_dissector.c | |
parent | ada1dba04c273dbabefff6a9a9f8c2bdcb61a858 (diff) | |
download | op-kernel-dev-2f59e1ebaa7f762c8825871b5486b5f5b4fa952f.zip op-kernel-dev-2f59e1ebaa7f762c8825871b5486b5f5b4fa952f.tar.gz |
net: Add flow_keys digest
Some users of flow keys (well just sch_choke now) need to pass
flow_keys in skbuff cb, and use them for exact comparisons of flows
so that skb->hash is not sufficient. In order to increase size of
the flow_keys structure, we introduce another structure for
the purpose of passing flow keys in skbuff cb. We limit this structure
to sixteen bytes, and we will technically treat this as a digest of
flow_keys struct hence its name flow_keys_digest. In the first
incaranation we just copy the flow_keys structure up to 16 bytes--
this is the same information previously passed in the cb. In the
future, we'll adapt this for larger flow_keys and could use something
like SHA-1 over the whole flow_keys to improve the quality of the
digest.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/flow_dissector.c')
-rw-r--r-- | net/core/flow_dissector.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index b1df995..d3acc4d 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -310,6 +310,33 @@ static inline u32 ___skb_get_hash(const struct sk_buff *skb, return __flow_hash_from_keys(keys, keyval); } +struct _flow_keys_digest_data { + __be16 n_proto; + u8 ip_proto; + u8 padding; + __be32 ports; + __be32 src; + __be32 dst; +}; + +void make_flow_keys_digest(struct flow_keys_digest *digest, + const struct flow_keys *flow) +{ + struct _flow_keys_digest_data *data = + (struct _flow_keys_digest_data *)digest; + + BUILD_BUG_ON(sizeof(*data) > sizeof(*digest)); + + memset(digest, 0, sizeof(*digest)); + + data->n_proto = flow->n_proto; + data->ip_proto = flow->ip_proto; + data->ports = flow->ports; + data->src = flow->src; + data->dst = flow->dst; +} +EXPORT_SYMBOL(make_flow_keys_digest); + /* * __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 |