flow-hash: Add symmetric flag for flow hashing

[vpp.git] / src / vnet / ip / ip4.h

diff --git a/src/vnet/ip/ip4.h b/src/vnet/ip/ip4.h
index 9cb54bd..31ca10f 100644 (file)
--- a/src/vnet/ip/ip4.h
+++ b/src/vnet/ip/ip4.h
@@ -308,7 +308,6 @@ ip4_compute_flow_hash (const ip4_header_t * ip,
 
   a = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ? t2 : t1;
   b = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ? t1 : t2;
-  b ^= (flow_hash_config & IP_FLOW_HASH_PROTO) ? ip->protocol : 0;
 
   t1 = is_tcp_udp ? tcp->src : 0;
   t2 = is_tcp_udp ? tcp->dst : 0;
@@ -316,6 +315,23 @@ ip4_compute_flow_hash (const ip4_header_t * ip,
   t1 = (flow_hash_config & IP_FLOW_HASH_SRC_PORT) ? t1 : 0;
   t2 = (flow_hash_config & IP_FLOW_HASH_DST_PORT) ? t2 : 0;
 
+  if (flow_hash_config & IP_FLOW_HASH_SYMMETRIC)
+    {
+      if (b < a)
+       {
+         c = a;
+         a = b;
+         b = c;
+       }
+      if (t2 < t1)
+       {
+         t2 += t1;
+         t1 = t2 - t1;
+         t2 = t2 - t1;
+       }
+    }
+
+  b ^= (flow_hash_config & IP_FLOW_HASH_PROTO) ? ip->protocol : 0;
   c = (flow_hash_config & IP_FLOW_HASH_REVERSE_SRC_DST) ?
     (t1 << 16) | t2 : (t2 << 16) | t1;