SPAN:add l2 mirror

added span feature nodes for l2-input / l2-output

Change-Id: Ib6e0ce60d0811901b6edd70209e6a4c4a35cd8ff
Signed-off-by: Eyal Bari <ebari@cisco.com>
diff --git a/src/vnet/l2/l2_input.h b/src/vnet/l2/l2_input.h
index 244ef44..e6b3bc7 100644
--- a/src/vnet/l2/l2_input.h
+++ b/src/vnet/l2/l2_input.h
@@ -102,7 +102,7 @@
 
 /* L2 input features */
 
-/* Mappings from feature ID to graph node name */
+/* Mappings from feature ID to graph node name in reverse order */
 #define foreach_l2input_feat                    \
  _(DROP,          "feature-bitmap-drop")        \
  _(XCONNECT,      "l2-output")                  \
@@ -116,7 +116,8 @@
  _(VPATH,         "vpath-input-l2")             \
  _(ACL,           "l2-input-acl")               \
  _(POLICER_CLAS,  "l2-policer-classify")	\
- _(INPUT_CLASSIFY, "l2-input-classify")
+ _(INPUT_CLASSIFY, "l2-input-classify")         \
+ _(SPAN,          "span-l2-input")
 
 /* Feature bitmap positions */
 typedef enum