ip: Reference count the enabling the punt feature

Type: fix

otherwise punt features are applied multiple times to the same packet if enabled multiple times

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: If0cbd9065275f68a10fd6d35e4f7a7c7508245e0
diff --git a/src/vnet/ip/ip6_punt_drop.c b/src/vnet/ip/ip6_punt_drop.c
index ab5203d..32a2ab7 100644
--- a/src/vnet/ip/ip6_punt_drop.c
+++ b/src/vnet/ip/ip6_punt_drop.c
@@ -301,6 +301,8 @@
 
 #ifndef CLIB_MARCH_VARIANT
 
+static u32 ip6_punt_redirect_enable_counts;
+
 void
 ip6_punt_redirect_add_paths (u32 rx_sw_if_index,
 			     const fib_route_path_t *rpaths)
@@ -309,13 +311,16 @@
 			rx_sw_if_index,
 			FIB_FORW_CHAIN_TYPE_UNICAST_IP6, rpaths);
 
-  vnet_feature_enable_disable ("ip6-punt", "ip6-punt-redirect", 0, 1, 0, 0);
+  if (1 == ++ip6_punt_redirect_enable_counts)
+    vnet_feature_enable_disable ("ip6-punt", "ip6-punt-redirect", 0, 1, 0, 0);
 }
 
 void
 ip6_punt_redirect_del (u32 rx_sw_if_index)
 {
-  vnet_feature_enable_disable ("ip6-punt", "ip6-punt-redirect", 0, 0, 0, 0);
+  ASSERT (ip6_punt_redirect_enable_counts);
+  if (0 == --ip6_punt_redirect_enable_counts)
+    vnet_feature_enable_disable ("ip6-punt", "ip6-punt-redirect", 0, 0, 0, 0);
 
   ip_punt_redirect_del (FIB_PROTOCOL_IP6, rx_sw_if_index);
 }