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-rw-r--r--include/net/flow_keys.h16
-rw-r--r--net/core/flow_dissector.c27
2 files changed, 43 insertions, 0 deletions
diff --git a/include/net/flow_keys.h b/include/net/flow_keys.h
index dc8fd81412bf..6d6ef626811a 100644
--- a/include/net/flow_keys.h
+++ b/include/net/flow_keys.h
@@ -42,4 +42,20 @@ static inline __be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8
u32 flow_hash_from_keys(struct flow_keys *keys);
unsigned int flow_get_hlen(const unsigned char *data, unsigned int max_len,
__be16 protocol);
+
+/* struct flow_keys_digest:
+ *
+ * This structure is used to hold a digest of the full flow keys. This is a
+ * larger "hash" of a flow to allow definitively matching specific flows where
+ * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
+ * that it can by used in CB of skb (see sch_choke for an example).
+ */
+#define FLOW_KEYS_DIGEST_LEN 16
+struct flow_keys_digest {
+ u8 data[FLOW_KEYS_DIGEST_LEN];
+};
+
+void make_flow_keys_digest(struct flow_keys_digest *digest,
+ const struct flow_keys *flow);
+
#endif
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index b1df995ef06c..d3acc4dff4ae 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

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