From c0a36c0d93c0625526daa1720a005b48da68370c Mon Sep 17 00:00:00 2001
From: Gabriel Ganne <gabriel.ganne@qosmos.com>
Date: Wed, 16 Nov 2016 16:57:00 +0100
Subject: [PATCH] handoff - allow symmetrical dispatch

update cli cmd with symmetrical|asymmetrical flag
(asymetrical by default)

Change-Id: I8186506413a3ba0aa0561c0448b5e06e6d6e7ece
Signed-off-by: Gabriel Ganne <gabriel.ganne@qosmos.com>
---
 vnet/vnet/handoff.c | 20 ++++++++++++++--
 vnet/vnet/handoff.h | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+), 2 deletions(-)

diff --git a/vnet/vnet/handoff.c b/vnet/vnet/handoff.c
index 22d2ea98df7..9f3c93b4b70 100644
--- a/vnet/vnet/handoff.c
+++ b/vnet/vnet/handoff.c
@@ -40,6 +40,8 @@ typedef struct
   /* convenience variables */
   vlib_main_t *vlib_main;
   vnet_main_t *vnet_main;
+
+    u64 (*hash_fn) (ethernet_header_t *);
 } handoff_main_t;
 
 handoff_main_t handoff_main;
@@ -123,7 +125,7 @@ worker_handoff_node_fn (vlib_main_t * vm,
        */
 
       /* Compute ingress LB hash */
-      hash_key = eth_get_key ((ethernet_header_t *) b0->data);
+      hash_key = hm->hash_fn ((ethernet_header_t *) b0->data);
       hash = (u32) clib_xxhash (hash_key);
 
       /* if input node did not specify next index, then packet
@@ -283,9 +285,11 @@ set_interface_handoff_command_fn (vlib_main_t * vm,
 				  unformat_input_t * input,
 				  vlib_cli_command_t * cmd)
 {
+  handoff_main_t *hm = &handoff_main;
   u32 sw_if_index = ~0;
   int enable_disable = 1;
   uword *bitmap = 0;
+  u32 sym = ~0;
 
   int rv = 0;
 
@@ -298,6 +302,10 @@ set_interface_handoff_command_fn (vlib_main_t * vm,
       else if (unformat (input, "%U", unformat_vnet_sw_interface,
 			 vnet_get_main (), &sw_if_index))
 	;
+      else if (unformat (input, "symmetrical"))
+	sym = 1;
+      else if (unformat (input, "asymmetrical"))
+	sym = 0;
       else
 	break;
     }
@@ -333,6 +341,12 @@ set_interface_handoff_command_fn (vlib_main_t * vm,
     default:
       return clib_error_return (0, "unknown return value %d", rv);
     }
+
+  if (sym == 1)
+    hm->hash_fn = eth_get_sym_key;
+  else if (sym == 0)
+    hm->hash_fn = eth_get_key;
+
   return 0;
 }
 
@@ -340,7 +354,7 @@ set_interface_handoff_command_fn (vlib_main_t * vm,
 VLIB_CLI_COMMAND (set_interface_handoff_command, static) = {
   .path = "set interface handoff",
   .short_help =
-  "set interface handoff <interface-name> workers <workers-list>",
+  "set interface handoff <interface-name> workers <workers-list> [symmetrical|asymmetrical]",
   .function = set_interface_handoff_command_fn,
 };
 /* *INDENT-ON* */
@@ -559,6 +573,8 @@ handoff_init (vlib_main_t * vm)
 	}
     }
 
+  hm->hash_fn = eth_get_key;
+
   hm->vlib_main = vm;
   hm->vnet_main = &vnet_main;
 
diff --git a/vnet/vnet/handoff.h b/vnet/vnet/handoff.h
index 4fefb369475..815206a9f8c 100644
--- a/vnet/vnet/handoff.h
+++ b/vnet/vnet/handoff.h
@@ -130,6 +130,72 @@ bottom_lbl_found:
 
 }
 
+static inline u64
+eth_get_sym_key (ethernet_header_t * h0)
+{
+  u64 hash_key;
+
+  if (PREDICT_TRUE (h0->type) == clib_host_to_net_u16 (ETHERNET_TYPE_IP4))
+    {
+      ip4_header_t *ip = (ip4_header_t *) (h0 + 1);
+      hash_key =
+	(u64) (ip->src_address.as_u32 ^
+	       ip->dst_address.as_u32 ^ ip->protocol);
+    }
+  else if (h0->type == clib_host_to_net_u16 (ETHERNET_TYPE_IP6))
+    {
+      ip6_header_t *ip = (ip6_header_t *) (h0 + 1);
+      hash_key = (u64) (ip->src_address.as_u64[0] ^
+			ip->src_address.as_u64[1] ^
+			ip->dst_address.as_u64[0] ^
+			ip->dst_address.as_u64[1] ^ ip->protocol);
+    }
+  else if (h0->type == clib_host_to_net_u16 (ETHERNET_TYPE_MPLS_UNICAST))
+    {
+      hash_key = mpls_get_key ((mpls_unicast_header_t *) (h0 + 1));
+    }
+  else
+    if (PREDICT_FALSE
+	((h0->type == clib_host_to_net_u16 (ETHERNET_TYPE_VLAN))
+	 || (h0->type == clib_host_to_net_u16 (ETHERNET_TYPE_DOT1AD))))
+    {
+      ethernet_vlan_header_t *outer = (ethernet_vlan_header_t *) (h0 + 1);
+
+      outer = (outer->type == clib_host_to_net_u16 (ETHERNET_TYPE_VLAN)) ?
+	outer + 1 : outer;
+      if (PREDICT_TRUE (outer->type) ==
+	  clib_host_to_net_u16 (ETHERNET_TYPE_IP4))
+	{
+	  ip4_header_t *ip = (ip4_header_t *) (outer + 1);
+	  hash_key =
+	    (u64) (ip->src_address.as_u32 ^
+		   ip->dst_address.as_u32 ^ ip->protocol);
+	}
+      else if (outer->type == clib_host_to_net_u16 (ETHERNET_TYPE_IP6))
+	{
+	  ip6_header_t *ip = (ip6_header_t *) (outer + 1);
+	  hash_key =
+	    (u64) (ip->src_address.as_u64[0] ^ ip->src_address.as_u64[1] ^
+		   ip->dst_address.as_u64[0] ^
+		   ip->dst_address.as_u64[1] ^ ip->protocol);
+	}
+      else if (outer->type ==
+	       clib_host_to_net_u16 (ETHERNET_TYPE_MPLS_UNICAST))
+	{
+	  hash_key = mpls_get_key ((mpls_unicast_header_t *) (outer + 1));
+	}
+      else
+	{
+	  hash_key = outer->type;
+	}
+    }
+  else
+    {
+      hash_key = 0;
+    }
+
+  return hash_key;
+}
 
 static inline u64
 eth_get_key (ethernet_header_t * h0)
-- 
2.16.6