net: let flow have same hash in two directions

[ Upstream commit 1e60cebf82948cfdc9497ea4553bab125587593c ]

using same source and destination ip/port for flow hash calculation
within the two directions.

Signed-off-by: zhang kai <zhangkaiheb@126.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 64ae13ed4784 ("net: core: fix flow symmetric hash")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index f9baa9b1c77f7cabcc6e8156780c0ac25b193bfb..aad311c7381075ba8d759d521fbe927dc04a03e4 100644 (file)
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -1485,7 +1485,7 @@ __be32 flow_get_u32_dst(const struct flow_keys *flow)
 }
 EXPORT_SYMBOL(flow_get_u32_dst);
 
-/* Sort the source and destination IP (and the ports if the IP are the same),
+/* Sort the source and destination IP and the ports,
  * to have consistent hash within the two directions
  */
 static inline void __flow_hash_consistentify(struct flow_keys *keys)
@@ -1496,11 +1496,11 @@ static inline void __flow_hash_consistentify(struct flow_keys *keys)
        case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
                addr_diff = (__force u32)keys->addrs.v4addrs.dst -
                            (__force u32)keys->addrs.v4addrs.src;
-               if ((addr_diff < 0) ||
-                   (addr_diff == 0 &&
-                    ((__force u16)keys->ports.dst <
-                     (__force u16)keys->ports.src))) {
+               if (addr_diff < 0)
                        swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
+
+               if ((__force u16)keys->ports.dst <
+                   (__force u16)keys->ports.src) {
                        swap(keys->ports.src, keys->ports.dst);
                }
                break;
@@ -1508,13 +1508,13 @@ static inline void __flow_hash_consistentify(struct flow_keys *keys)
                addr_diff = memcmp(&keys->addrs.v6addrs.dst,
                                   &keys->addrs.v6addrs.src,
                                   sizeof(keys->addrs.v6addrs.dst));
-               if ((addr_diff < 0) ||
-                   (addr_diff == 0 &&
-                    ((__force u16)keys->ports.dst <
-                     (__force u16)keys->ports.src))) {
+               if (addr_diff < 0) {
                        for (i = 0; i < 4; i++)
                                swap(keys->addrs.v6addrs.src.s6_addr32[i],
                                     keys->addrs.v6addrs.dst.s6_addr32[i]);
+               }
+               if ((__force u16)keys->ports.dst <
+                   (__force u16)keys->ports.src) {
                        swap(keys->ports.src, keys->ports.dst);
                }
                break;