ipsec: Support MPLS over IPSec[46] interface

Type: feature

Signed-off-by: Neale Ranns <nranns@cisco.com>
Change-Id: I89dc3815eabfee135cd5b3c910dea5e2e2ef1333
diff --git a/src/vnet/ipsec/esp.h b/src/vnet/ipsec/esp.h
index 0121015..d24b5ea 100644
--- a/src/vnet/ipsec/esp.h
+++ b/src/vnet/ipsec/esp.h
@@ -235,6 +235,7 @@
   u32 esp6_post_next;
   u32 esp4_tun_post_next;
   u32 esp6_tun_post_next;
+  u32 esp_mpls_tun_post_next;
 } esp_async_post_next_t;
 
 extern esp_async_post_next_t esp_encrypt_async_next;