Punt Infra

A punt/exception path that provides:
 1) clients that use the infra
 2) clients can create punt reasons
 3) clients can register to recieve packets that are punted
    for a given reason to be sent to the desired node.
 4) nodes which punt packets fill in the {reason,protocol} of the
    buffere (in the meta-data) and send to the new node "punt-dispatch"
 5) punt-dispatch sends packets to the registered nodes or drops

Change-Id: Ia4f144337f1387cbe585b4f375d0842aefffcde5
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/src/vlib/buffer.h b/src/vlib/buffer.h
index 514e73bd7ca..0fd57f5275b 100644
--- a/src/vlib/buffer.h
+++ b/src/vlib/buffer.h
@@ -139,8 +139,15 @@ typedef union
       * VLIB_BUFFER_NEXT_PRESENT flag is set. */
     u32 next_buffer;
 
-    /** Used by feature subgraph arcs to visit enabled feature nodes */
-    u32 current_config_index;
+    /** The following fields can be in a union because once a packet enters
+     * the punt path, it is no longer on a feature arc */
+    union
+    {
+      /** Used by feature subgraph arcs to visit enabled feature nodes */
+      u32 current_config_index;
+      /* the reason the packet once punted */
+      u32 punt_reason;
+    };
 
     /** Opaque data used by sub-graphs for their own purposes. */
     u32 opaque[10];