flow_dissector: fix doc for __skb_get_hash and remove couple of empty lines

[mirror_ubuntu-bionic-kernel.git] / net / core / flow_dissector.c

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 2c35c02a931e227fa368cd346873596d4b037a3d..0d9bc3a586bae79f4b786b456adfdcdadc126029 100644 (file)
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -12,7 +12,7 @@
 #include <linux/if_tunnel.h>
 #include <linux/if_pppox.h>
 #include <linux/ppp_defs.h>
-#include <net/flow_keys.h>
+#include <net/flow_dissector.h>
 #include <scsi/fc/fc_fcoe.h>
 
 /* copy saddr & daddr, possibly using 64bit load/store
@@ -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;
 
@@ -296,12 +296,52 @@ 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);
 
-/*
- * __skb_get_hash: calculate a flow hash based on src/dst addresses
+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);
+}
+
+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
+ * @skb: sk_buff to calculate flow hash from
+ *
+ * This function calculates a flow hash based on src/dst addresses
  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
  * if hash is a canonical 4-tuple hash over transport ports.
@@ -309,19 +349,28 @@ 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))
-               return;
+       __flow_hash_secret_init();
 
+       hash = ___skb_get_hash(skb, &keys, hashrnd);
+       if (!hash)
+               return;
        if (keys.ports)
                skb->l4_hash = 1;
-
        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.