SPAN:add l2 mirror

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

Change-Id: Ib6e0ce60d0811901b6edd70209e6a4c4a35cd8ff
Signed-off-by: Eyal Bari <ebari@cisco.com>

10 files changed, 284 insertions, 138 deletions

diff --git a/src/vat/api_format.c b/src/vat/api_format.c
index 40eca8c5d57..932e162d7bc 100644
--- a/src/vat/api_format.c
+++ b/src/vat/api_format.c
@@ -18082,6 +18082,7 @@ api_sw_interface_span_enable_disable (vat_main_t * vam)
   u32 dst_sw_if_index = ~0;
   u8 state = 3;
   int ret;
+  u8 is_l2 = 0;
 
   while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
     {
@@ -18104,6 +18105,8 @@ api_sw_interface_span_enable_disable (vat_main_t * vam)
 	state = 2;
       else if (unformat (i, "both"))
 	state = 3;
+      else if (unformat (i, "l2"))
+	is_l2 = 1;
       else
 	break;
     }
@@ -18113,6 +18116,7 @@ api_sw_interface_span_enable_disable (vat_main_t * vam)
   mp->sw_if_index_from = htonl (src_sw_if_index);
   mp->sw_if_index_to = htonl (dst_sw_if_index);
   mp->state = state;
+  mp->is_l2 = is_l2;
 
   S (mp);
   W (ret);
@@ -20044,7 +20048,7 @@ _(set_ipfix_classify_stream, "[domain <domain-id>] [src_port <src-port>]") \
 _(ipfix_classify_stream_dump, "")                                       \
 _(ipfix_classify_table_add_del, "table <table-index> ip4|ip6 [tcp|udp]") \
 _(ipfix_classify_table_dump, "")                                        \
-_(sw_interface_span_enable_disable, "[src <intfc> | src_sw_if_index <id>] [disable | [[dst <intfc> | dst_sw_if_index <id>] [both|rx|tx]]]") \
+_(sw_interface_span_enable_disable, "[l2] [src <intfc> | src_sw_if_index <id>] [disable | [[dst <intfc> | dst_sw_if_index <id>] [both|rx|tx]]]") \
 _(sw_interface_span_dump, "")                                           \
 _(get_next_index, "node-name <node-name> next-node-name <node-name>")   \
 _(pg_create_interface, "if_id <nn>")                                    \
diff --git a/src/vnet/l2/l2_input.h b/src/vnet/l2/l2_input.h
index 244ef445ca8..e6b3bc7f9cd 100644
--- a/src/vnet/l2/l2_input.h
+++ b/src/vnet/l2/l2_input.h
@@ -102,7 +102,7 @@ l2input_bd_config (u32 bd_index)
 
 /* 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 @@ l2input_bd_config (u32 bd_index)
  _(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
diff --git a/src/vnet/l2/l2_output.c b/src/vnet/l2/l2_output.c
index b3537a355cf..fbee590c944 100644
--- a/src/vnet/l2/l2_output.c
+++ b/src/vnet/l2/l2_output.c
@@ -195,8 +195,6 @@ l2output_vtr (vlib_node_runtime_t * node, l2_output_config_t * config,
 }
 
 
-static vlib_node_registration_t l2output_node;
-
 static_always_inline uword
 l2output_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 		      vlib_frame_t * frame, int do_trace)
@@ -477,7 +475,7 @@ l2output_node_fn (vlib_main_t * vm,
 }
 
 /* *INDENT-OFF* */
-VLIB_REGISTER_NODE (l2output_node,static) = {
+VLIB_REGISTER_NODE (l2output_node) = {
   .function = l2output_node_fn,
   .name = "l2-output",
   .vector_size = sizeof (u32),
@@ -495,6 +493,8 @@ VLIB_REGISTER_NODE (l2output_node,static) = {
         [L2OUTPUT_NEXT_BAD_INTF] = "l2-output-bad-intf",
   },
 };
+
+VLIB_NODE_FUNCTION_MULTIARCH (l2output_node, l2output_node_fn);
 /* *INDENT-ON* */
 
 
@@ -601,11 +601,12 @@ VLIB_REGISTER_NODE (l2output_bad_intf_node,static) = {
 	[0] = "error-drop",
   },
 };
-/* *INDENT-ON* */
 
+VLIB_NODE_FUNCTION_MULTIARCH (l2output_bad_intf_node, l2output_bad_intf_node_fn);
+/* *INDENT-ON* */
 
-VLIB_NODE_FUNCTION_MULTIARCH (l2output_node, l2output_node_fn)
-     clib_error_t *l2output_init (vlib_main_t * vm)
+static clib_error_t *
+l2output_init (vlib_main_t * vm)
 {
   l2output_main_t *mp = &l2output_main;
 
diff --git a/src/vnet/l2/l2_output.h b/src/vnet/l2/l2_output.h
index 6da3e303c3b..a54b8d67c93 100644
--- a/src/vnet/l2/l2_output.h
+++ b/src/vnet/l2/l2_output.h
@@ -77,12 +77,14 @@ typedef struct
 
 l2output_main_t l2output_main;
 
+extern vlib_node_registration_t l2output_node;
+
 /* L2 output features */
 
-/* Mappings from feature ID to graph node name */
+/* Mappings from feature ID to graph node name in reverse order */
 #define foreach_l2output_feat \
  _(OUTPUT,            "interface-output")           \
- _(SPAN,              "feature-bitmap-drop")        \
+ _(SPAN,              "span-l2-output")             \
  _(CFM,               "feature-bitmap-drop")        \
  _(QOS,               "feature-bitmap-drop")        \
  _(ACL,               "l2-output-acl")              \
@@ -103,6 +105,8 @@ typedef enum
     L2OUTPUT_N_FEAT,
 } l2output_feat_t;
 
+STATIC_ASSERT (L2OUTPUT_N_FEAT <= 32, "too many l2 output features");
+
 /* Feature bit masks */
 typedef enum
 {
diff --git a/src/vnet/span/node.c b/src/vnet/span/node.c
index 3a461b0a3d3..9d83d4ef288 100644
--- a/src/vnet/span/node.c
+++ b/src/vnet/span/node.c
@@ -18,6 +18,9 @@
 #include <vppinfra/error.h>
 
 #include <vnet/span/span.h>
+#include <vnet/l2/l2_input.h>
+#include <vnet/l2/l2_output.h>
+#include <vnet/l2/feat_bitmap.h>
 
 #include <vppinfra/error.h>
 #include <vppinfra/elog.h>
@@ -59,21 +62,19 @@ static char *span_error_strings[] = {
 
 static_always_inline void
 span_mirror (vlib_main_t * vm, vlib_node_runtime_t * node, u32 sw_if_index0,
-	     vlib_buffer_t * b0, vlib_frame_t ** mirror_frames, int is_rx)
+	     vlib_buffer_t * b0, vlib_frame_t ** mirror_frames,
+	     vlib_rx_or_tx_t rxtx, span_feat_t sf)
 {
   vlib_buffer_t *c0;
   span_main_t *sm = &span_main;
   vnet_main_t *vnm = &vnet_main;
-  span_interface_t *si0 = 0;
   u32 *to_mirror_next = 0;
   u32 i;
 
-  si0 = vec_elt_at_index (sm->interfaces, sw_if_index0);
+  span_interface_t *si0 = vec_elt_at_index (sm->interfaces, sw_if_index0);
+  span_mirror_t *sm0 = &si0->mirror_rxtx[sf][rxtx];
 
-  if (is_rx != 0 && si0->num_rx_mirror_ports == 0)
-    return;
-
-  if (is_rx == 0 && si0->num_tx_mirror_ports == 0)
+  if (sm0->num_mirror_ports == 0)
     return;
 
   /* Don't do it again */
@@ -81,10 +82,15 @@ span_mirror (vlib_main_t * vm, vlib_node_runtime_t * node, u32 sw_if_index0,
     return;
 
   /* *INDENT-OFF* */
-  clib_bitmap_foreach (i, is_rx ? si0->rx_mirror_ports : si0->tx_mirror_ports, (
+  clib_bitmap_foreach (i, sm0->mirror_ports, (
     {
       if (mirror_frames[i] == 0)
-	mirror_frames[i] = vnet_get_frame_to_sw_interface (vnm, i);
+        {
+          if (sf == SPAN_FEAT_L2)
+            mirror_frames[i] = vlib_get_frame_to_node (vnm->vlib_main, l2output_node.index);
+          else
+            mirror_frames[i] = vnet_get_frame_to_sw_interface (vnm, i);
+	}
       to_mirror_next = vlib_frame_vector_args (mirror_frames[i]);
       to_mirror_next += mirror_frames[i]->n_vectors;
       /* This can fail */
@@ -93,6 +99,8 @@ span_mirror (vlib_main_t * vm, vlib_node_runtime_t * node, u32 sw_if_index0,
         {
           vnet_buffer (c0)->sw_if_index[VLIB_TX] = i;
           c0->flags |= VNET_BUFFER_F_SPAN_CLONE;
+          if (sf == SPAN_FEAT_L2)
+	    vnet_buffer (c0)->l2.feature_bitmap = L2OUTPUT_FEAT_OUTPUT;
           to_mirror_next[0] = vlib_get_buffer_index (vm, c0);
           mirror_frames[i]->n_vectors++;
           if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
@@ -108,7 +116,8 @@ span_mirror (vlib_main_t * vm, vlib_node_runtime_t * node, u32 sw_if_index0,
 
 static_always_inline uword
 span_node_inline_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
-		     vlib_frame_t * frame, int is_rx)
+		     vlib_frame_t * frame, vlib_rx_or_tx_t rxtx,
+		     span_feat_t sf)
 {
   span_main_t *sm = &span_main;
   vnet_main_t *vnm = &vnet_main;
@@ -117,7 +126,6 @@ span_node_inline_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
   u32 next_index;
   u32 sw_if_index;
   static __thread vlib_frame_t **mirror_frames = 0;
-  vlib_rx_or_tx_t rxtx = is_rx ? VLIB_RX : VLIB_TX;
 
   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;
@@ -156,11 +164,33 @@ span_node_inline_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[rxtx];
 	  sw_if_index1 = vnet_buffer (b1)->sw_if_index[rxtx];
 
-	  span_mirror (vm, node, sw_if_index0, b0, mirror_frames, is_rx);
-	  span_mirror (vm, node, sw_if_index1, b1, mirror_frames, is_rx);
-
-	  vnet_feature_next (sw_if_index0, &next0, b0);
-	  vnet_feature_next (sw_if_index1, &next1, b1);
+	  span_mirror (vm, node, sw_if_index0, b0, mirror_frames, rxtx, sf);
+	  span_mirror (vm, node, sw_if_index1, b1, mirror_frames, rxtx, sf);
+
+	  switch (sf)
+	    {
+	    case SPAN_FEAT_L2:
+	      if (rxtx == VLIB_RX)
+		{
+		  next0 = vnet_l2_feature_next (b0, sm->l2_input_next,
+						L2INPUT_FEAT_SPAN);
+		  next1 = vnet_l2_feature_next (b1, sm->l2_input_next,
+						L2INPUT_FEAT_SPAN);
+		}
+	      else
+		{
+		  next0 = vnet_l2_feature_next (b0, sm->l2_output_next,
+						L2OUTPUT_FEAT_SPAN);
+		  next1 = vnet_l2_feature_next (b1, sm->l2_output_next,
+						L2OUTPUT_FEAT_SPAN);
+		}
+	      break;
+	    case SPAN_FEAT_DEVICE:
+	    default:
+	      vnet_feature_next (sw_if_index0, &next0, b0);
+	      vnet_feature_next (sw_if_index1, &next1, b1);
+	      break;
+	    }
 
 	  /* verify speculative enqueue, maybe switch current next frame */
 	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
@@ -184,9 +214,23 @@ span_node_inline_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 	  b0 = vlib_get_buffer (vm, bi0);
 	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[rxtx];
 
-	  span_mirror (vm, node, sw_if_index0, b0, mirror_frames, is_rx);
-
-	  vnet_feature_next (sw_if_index0, &next0, b0);
+	  span_mirror (vm, node, sw_if_index0, b0, mirror_frames, rxtx, sf);
+
+	  switch (sf)
+	    {
+	    case SPAN_FEAT_L2:
+	      if (rxtx == VLIB_RX)
+		next0 = vnet_l2_feature_next (b0, sm->l2_input_next,
+					      L2INPUT_FEAT_SPAN);
+	      else
+		next0 = vnet_l2_feature_next (b0, sm->l2_output_next,
+					      L2OUTPUT_FEAT_SPAN);
+	      break;
+	    case SPAN_FEAT_DEVICE:
+	    default:
+	      vnet_feature_next (sw_if_index0, &next0, b0);
+	      break;
+	    }
 
 	  /* verify speculative enqueue, maybe switch current next frame */
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
@@ -199,11 +243,14 @@ span_node_inline_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 
   for (sw_if_index = 0; sw_if_index < vec_len (mirror_frames); sw_if_index++)
     {
-      if (mirror_frames[sw_if_index] == 0)
+      vlib_frame_t *f = mirror_frames[sw_if_index];
+      if (f == 0)
 	continue;
 
-      vnet_put_frame_to_sw_interface (vnm, sw_if_index,
-				      mirror_frames[sw_if_index]);
+      if (sf == SPAN_FEAT_L2)
+	vlib_put_frame_to_node (vnm->vlib_main, l2output_node.index, f);
+      else
+	vnet_put_frame_to_sw_interface (vnm, sw_if_index, f);
       mirror_frames[sw_if_index] = 0;
     }
   vlib_node_increment_counter (vm, span_node.index, SPAN_ERROR_HITS,
@@ -213,62 +260,103 @@ span_node_inline_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 }
 
 static uword
-span_input_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
-		    vlib_frame_t * frame)
+span_device_input_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+			   vlib_frame_t * frame)
 {
-  return span_node_inline_fn (vm, node, frame, 1);
+  return span_node_inline_fn (vm, node, frame, VLIB_RX, SPAN_FEAT_DEVICE);
 }
 
 static uword
-span_output_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
-		     vlib_frame_t * frame)
+span_device_output_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+			    vlib_frame_t * frame)
 {
-  return span_node_inline_fn (vm, node, frame, 0);
+  return span_node_inline_fn (vm, node, frame, VLIB_TX, SPAN_FEAT_DEVICE);
 }
 
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (span_input_node) = {
-  .function = span_input_node_fn,
-  .name = "span-input",
-  .vector_size = sizeof (u32),
-  .format_trace = format_span_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
+static uword
+span_l2_input_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+		       vlib_frame_t * frame)
+{
+  return span_node_inline_fn (vm, node, frame, VLIB_RX, SPAN_FEAT_L2);
+}
 
-  .n_errors = ARRAY_LEN(span_error_strings),
-  .error_strings = span_error_strings,
+static uword
+span_l2_output_node_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
+			vlib_frame_t * frame)
+{
+  return span_node_inline_fn (vm, node, frame, VLIB_TX, SPAN_FEAT_L2);
+}
 
-  .n_next_nodes = 0,
+#define span_node_defs                           \
+  .vector_size = sizeof (u32),                   \
+  .format_trace = format_span_trace,             \
+  .type = VLIB_NODE_TYPE_INTERNAL,               \
+  .n_errors = ARRAY_LEN(span_error_strings),     \
+  .error_strings = span_error_strings,           \
+  .n_next_nodes = 0,                             \
+  .next_nodes = {                                \
+    [0] = "error-drop"                           \
+  }
 
-  /* edit / add dispositions here */
-  .next_nodes = {
-    [0] = "error-drop",
-  },
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (span_input_node) = {
+  span_node_defs,
+  .function = span_device_input_node_fn,
+  .name = "span-input",
 };
 
-VLIB_NODE_FUNCTION_MULTIARCH (span_input_node, span_input_node_fn)
+VLIB_NODE_FUNCTION_MULTIARCH (span_input_node, span_device_input_node_fn)
 
 VLIB_REGISTER_NODE (span_output_node) = {
-  .function = span_output_node_fn,
+  span_node_defs,
+  .function = span_device_output_node_fn,
   .name = "span-output",
-  .vector_size = sizeof (u32),
-  .format_trace = format_span_trace,
-  .type = VLIB_NODE_TYPE_INTERNAL,
+};
 
-  .n_errors = ARRAY_LEN(span_error_strings),
-  .error_strings = span_error_strings,
+VLIB_NODE_FUNCTION_MULTIARCH (span_output_node, span_device_output_node_fn)
 
-  .n_next_nodes = 0,
+VLIB_REGISTER_NODE (span_l2_input_node) = {
+  span_node_defs,
+  .function = span_l2_input_node_fn,
+  .name = "span-l2-input",
+};
 
-  /* edit / add dispositions here */
-  .next_nodes = {
-    [0] = "error-drop",
-  },
+VLIB_NODE_FUNCTION_MULTIARCH (span_l2_input_node, span_l2_input_node_fn)
+
+VLIB_REGISTER_NODE (span_l2_output_node) = {
+  span_node_defs,
+  .function = span_l2_output_node_fn,
+  .name = "span-l2-output",
 };
 
-VLIB_NODE_FUNCTION_MULTIARCH (span_output_node, span_output_node_fn)
+VLIB_NODE_FUNCTION_MULTIARCH (span_l2_output_node, span_l2_output_node_fn)
+
+clib_error_t *span_init (vlib_main_t * vm)
+{
+  span_main_t *sm = &span_main;
+
+  sm->vlib_main = vm;
+  sm->vnet_main = vnet_get_main ();
+
+  /* Initialize the feature next-node indexes */
+  feat_bitmap_init_next_nodes (vm,
+			       span_l2_input_node.index,
+			       L2INPUT_N_FEAT,
+			       l2input_get_feat_names (),
+			       sm->l2_input_next);
+
+  feat_bitmap_init_next_nodes (vm,
+			       span_l2_output_node.index,
+			       L2OUTPUT_N_FEAT,
+			       l2output_get_feat_names (),
+			       sm->l2_output_next);
+  return 0;
+}
 
+VLIB_INIT_FUNCTION (span_init);
 /* *INDENT-ON* */
 
+#undef span_node_defs
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/src/vnet/span/span.api b/src/vnet/span/span.api
index 914fd8d0b40..2a762ac2582 100644
--- a/src/vnet/span/span.api
+++ b/src/vnet/span/span.api
@@ -27,6 +27,7 @@ autoreply define sw_interface_span_enable_disable {
     u32 sw_if_index_from;
     u32 sw_if_index_to;
     u8  state;
+    u8  is_l2;
 };
 
 /** \brief SPAN dump request
diff --git a/src/vnet/span/span.c b/src/vnet/span/span.c
index c5b43e343c4..6ecd17895ef 100644
--- a/src/vnet/span/span.c
+++ b/src/vnet/span/span.c
@@ -16,60 +16,81 @@
 #include <vlib/vlib.h>
 #include <vppinfra/error.h>
 #include <vnet/feature/feature.h>
+#include <vnet/l2/l2_input.h>
+#include <vnet/l2/l2_output.h>
 
 #include <vnet/span/span.h>
 
+typedef enum
+{
+  SPAN_DISABLE = 0,
+  SPAN_RX = 1,
+  SPAN_TX = 2,
+  SPAN_BOTH = SPAN_RX | SPAN_TX
+} span_state_t;
+
+static_always_inline u32
+span_dst_set (span_mirror_t * sm, u32 dst_sw_if_index, int enable)
+{
+  sm->mirror_ports =
+    clib_bitmap_set (sm->mirror_ports, dst_sw_if_index, enable);
+  u32 last = sm->num_mirror_ports;
+  sm->num_mirror_ports = clib_bitmap_count_set_bits (sm->mirror_ports);
+  return last;
+}
+
 int
 span_add_delete_entry (vlib_main_t * vm,
-		       u32 src_sw_if_index, u32 dst_sw_if_index, u8 state)
+		       u32 src_sw_if_index, u32 dst_sw_if_index, u8 state,
+		       span_feat_t sf)
 {
   span_main_t *sm = &span_main;
-  span_interface_t *si;
-  u32 new_num_rx_mirror_ports, new_num_tx_mirror_ports;
 
-  if (state > 3)
+  if (state > SPAN_BOTH)
     return VNET_API_ERROR_UNIMPLEMENTED;
 
   if ((src_sw_if_index == ~0) || (dst_sw_if_index == ~0 && state > 0)
       || (src_sw_if_index == dst_sw_if_index))
     return VNET_API_ERROR_INVALID_INTERFACE;
 
-  vnet_sw_interface_t *sw_if;
-
-  sw_if = vnet_get_sw_interface (vnet_get_main (), src_sw_if_index);
-  if (sw_if->type == VNET_SW_INTERFACE_TYPE_SUB)
-    return VNET_API_ERROR_UNIMPLEMENTED;
-
   vec_validate_aligned (sm->interfaces, src_sw_if_index,
 			CLIB_CACHE_LINE_BYTES);
-  si = vec_elt_at_index (sm->interfaces, src_sw_if_index);
-
-  si->rx_mirror_ports = clib_bitmap_set (si->rx_mirror_ports, dst_sw_if_index,
-					 (state & 1) != 0);
-  si->tx_mirror_ports = clib_bitmap_set (si->tx_mirror_ports, dst_sw_if_index,
-					 (state & 2) != 0);
 
-  new_num_rx_mirror_ports = clib_bitmap_count_set_bits (si->rx_mirror_ports);
-  new_num_tx_mirror_ports = clib_bitmap_count_set_bits (si->tx_mirror_ports);
+  span_interface_t *si = vec_elt_at_index (sm->interfaces, src_sw_if_index);
 
-  if (new_num_rx_mirror_ports == 1 && si->num_rx_mirror_ports == 0)
-    vnet_feature_enable_disable ("device-input", "span-input",
-				 src_sw_if_index, 1, 0, 0);
+  int rx = ! !(state & SPAN_RX);
+  int tx = ! !(state & SPAN_TX);
 
-  if (new_num_rx_mirror_ports == 0 && si->num_rx_mirror_ports == 1)
-    vnet_feature_enable_disable ("device-input", "span-input",
-				 src_sw_if_index, 0, 0, 0);
+  span_mirror_t *rxm = &si->mirror_rxtx[sf][VLIB_RX];
+  span_mirror_t *txm = &si->mirror_rxtx[sf][VLIB_TX];
 
-  if (new_num_rx_mirror_ports == 1 && si->num_rx_mirror_ports == 0)
-    vnet_feature_enable_disable ("interface-output", "span-output",
-				 src_sw_if_index, 1, 0, 0);
+  u32 last_rx_ports_count = span_dst_set (rxm, dst_sw_if_index, rx);
+  u32 last_tx_ports_count = span_dst_set (txm, dst_sw_if_index, tx);
 
-  if (new_num_rx_mirror_ports == 0 && si->num_rx_mirror_ports == 1)
-    vnet_feature_enable_disable ("interface-output", "span-output",
-				 src_sw_if_index, 0, 0, 0);
+  int enable_rx = last_rx_ports_count == 0 && rxm->num_mirror_ports == 1;
+  int disable_rx = last_rx_ports_count == 1 && rxm->num_mirror_ports == 0;
+  int enable_tx = last_tx_ports_count == 0 && txm->num_mirror_ports == 1;
+  int disable_tx = last_tx_ports_count == 1 && txm->num_mirror_ports == 0;
 
-  si->num_rx_mirror_ports = new_num_rx_mirror_ports;
-  si->num_tx_mirror_ports = new_num_tx_mirror_ports;
+  switch (sf)
+    {
+    case SPAN_FEAT_DEVICE:
+      if (enable_rx || disable_rx)
+	vnet_feature_enable_disable ("device-input", "span-input",
+				     src_sw_if_index, rx, 0, 0);
+      if (enable_tx || disable_tx)
+	vnet_feature_enable_disable ("interface-output", "span-output",
+				     src_sw_if_index, tx, 0, 0);
+      break;
+    case SPAN_FEAT_L2:
+      if (enable_rx || disable_rx)
+	l2input_intf_bitmap_enable (src_sw_if_index, L2INPUT_FEAT_SPAN, rx);
+      if (enable_tx || disable_tx)
+	l2output_intf_bitmap_enable (src_sw_if_index, L2OUTPUT_FEAT_SPAN, tx);
+      break;
+    default:
+      return VNET_API_ERROR_UNIMPLEMENTED;
+    }
 
   if (dst_sw_if_index > sm->max_sw_if_index)
     sm->max_sw_if_index = dst_sw_if_index;
@@ -85,7 +106,8 @@ set_interface_span_command_fn (vlib_main_t * vm,
   span_main_t *sm = &span_main;
   u32 src_sw_if_index = ~0;
   u32 dst_sw_if_index = ~0;
-  u8 state = 3;
+  u8 state = SPAN_BOTH;
+  span_feat_t sf = SPAN_FEAT_DEVICE;
 
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
@@ -96,19 +118,21 @@ set_interface_span_command_fn (vlib_main_t * vm,
 			 sm->vnet_main, &dst_sw_if_index))
 	;
       else if (unformat (input, "disable"))
-	state = 0;
+	state = SPAN_DISABLE;
       else if (unformat (input, "rx"))
-	state = 1;
+	state = SPAN_RX;
       else if (unformat (input, "tx"))
-	state = 2;
+	state = SPAN_TX;
       else if (unformat (input, "both"))
-	state = 3;
+	state = SPAN_BOTH;
+      else if (unformat (input, "l2"))
+	sf = SPAN_FEAT_L2;
       else
 	break;
     }
 
   int rv =
-    span_add_delete_entry (vm, src_sw_if_index, dst_sw_if_index, state);
+    span_add_delete_entry (vm, src_sw_if_index, dst_sw_if_index, state, sf);
   if (rv == VNET_API_ERROR_INVALID_INTERFACE)
     return clib_error_return (0, "Invalid interface");
   return 0;
@@ -117,7 +141,7 @@ set_interface_span_command_fn (vlib_main_t * vm,
 /* *INDENT-OFF* */
 VLIB_CLI_COMMAND (set_interface_span_command, static) = {
   .path = "set interface span",
-  .short_help = "set interface span <if-name> [disable | destination <if-name> [both|rx|tx]]",
+  .short_help = "set interface span <if-name> [l2] {disable | destination <if-name> [both|rx|tx]}",
   .function = set_interface_span_command_fn,
 };
 /* *INDENT-ON* */
@@ -136,31 +160,44 @@ show_interfaces_span_command_fn (vlib_main_t * vm,
 
   /* *INDENT-OFF* */
   vec_foreach (si, sm->interfaces)
-    if (si->num_rx_mirror_ports || si->num_tx_mirror_ports)
+  {
+  span_mirror_t * drxm = &si->mirror_rxtx[SPAN_FEAT_DEVICE][VLIB_RX];
+  span_mirror_t * dtxm = &si->mirror_rxtx[SPAN_FEAT_DEVICE][VLIB_TX];
+
+  span_mirror_t * lrxm = &si->mirror_rxtx[SPAN_FEAT_L2][VLIB_RX];
+  span_mirror_t * ltxm = &si->mirror_rxtx[SPAN_FEAT_L2][VLIB_TX];
+
+    if (drxm->num_mirror_ports || dtxm->num_mirror_ports ||
+        lrxm->num_mirror_ports || ltxm->num_mirror_ports)
       {
-	clib_bitmap_t *b;
 	u32 i;
-	b = clib_bitmap_dup_or (si->rx_mirror_ports, si->tx_mirror_ports);
+	clib_bitmap_t *d = clib_bitmap_dup_or (drxm->mirror_ports, dtxm->mirror_ports);
+	clib_bitmap_t *l = clib_bitmap_dup_or (lrxm->mirror_ports, ltxm->mirror_ports);
+	clib_bitmap_t *b = clib_bitmap_dup_or (d, l);
 	if (header)
 	  {
-	    vlib_cli_output (vm, "%-40s %s", "Source interface",
-			     "Mirror interface (direction)");
+	    vlib_cli_output (vm, "%-20s %-20s  %6s   %6s", "Source", "Destination",
+			     "Device", "L2");
 	    header = 0;
 	  }
 	s = format (s, "%U", format_vnet_sw_if_index_name, vnm,
 		    si - sm->interfaces);
 	clib_bitmap_foreach (i, b, (
 	  {
-	    int state;
-	    state = (clib_bitmap_get (si->rx_mirror_ports, i) +
-		     clib_bitmap_get (si->tx_mirror_ports, i) * 2);
+	    int device = (clib_bitmap_get (drxm->mirror_ports, i) +
+		         clib_bitmap_get (dtxm->mirror_ports, i) * 2);
+	    int l2 = (clib_bitmap_get (lrxm->mirror_ports, i) +
+		      clib_bitmap_get (ltxm->mirror_ports, i) * 2);
 
-	    vlib_cli_output (vm, "%-40v %U (%s)", s,
+	    vlib_cli_output (vm, "%-20v %-20U (%6s) (%6s)", s,
 			     format_vnet_sw_if_index_name, vnm, i,
-			     states[state]);
+			     states[device], states[l2]);
 	    vec_reset_length (s);
 	  }));
 	clib_bitmap_free (b);
+	clib_bitmap_free (l);
+	clib_bitmap_free (d);
+      }
       }
   /* *INDENT-ON* */
   vec_free (s);
@@ -175,19 +212,6 @@ VLIB_CLI_COMMAND (show_interfaces_span_command, static) = {
 };
 /* *INDENT-ON* */
 
-static clib_error_t *
-span_init (vlib_main_t * vm)
-{
-  span_main_t *sm = &span_main;
-
-  sm->vlib_main = vm;
-  sm->vnet_main = vnet_get_main ();
-
-  return 0;
-}
-
-VLIB_INIT_FUNCTION (span_init);
-
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/src/vnet/span/span.h b/src/vnet/span/span.h
index a98b010bf61..10de8272ab0 100644
--- a/src/vnet/span/span.h
+++ b/src/vnet/span/span.h
@@ -18,17 +18,32 @@
 
 #include <vnet/vnet.h>
 #include <vnet/ip/ip.h>
+#include <vnet/l2/l2_output.h>
+
+typedef enum
+{
+  SPAN_FEAT_DEVICE,
+  SPAN_FEAT_L2,
+  SPAN_FEAT_N
+} span_feat_t;
+
+typedef struct
+{
+  clib_bitmap_t *mirror_ports;
+  u32 num_mirror_ports;
+} span_mirror_t;
 
 typedef struct
 {
-  clib_bitmap_t *rx_mirror_ports;
-  clib_bitmap_t *tx_mirror_ports;
-  u32 num_rx_mirror_ports;
-  u32 num_tx_mirror_ports;
+  span_mirror_t mirror_rxtx[SPAN_FEAT_N][VLIB_N_RX_TX];
 } span_interface_t;
 
 typedef struct
 {
+  /* l2 feature Next nodes */
+  u32 l2_input_next[32];
+  u32 l2_output_next[32];
+
   /* per-interface vector of span instances */
   span_interface_t *interfaces;
 
@@ -52,7 +67,7 @@ typedef struct
 
 int
 span_add_delete_entry (vlib_main_t * vm, u32 src_sw_if_index,
-		       u32 dst_sw_if_index, u8 is_add);
+		       u32 dst_sw_if_index, u8 state, span_feat_t sf);
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/src/vnet/span/span_api.c b/src/vnet/span/span_api.c
index b4565663eb9..69fa8e974fa 100644
--- a/src/vnet/span/span_api.c
+++ b/src/vnet/span/span_api.c
@@ -56,7 +56,8 @@ static void
   vlib_main_t *vm = vlib_get_main ();
 
   rv = span_add_delete_entry (vm, ntohl (mp->sw_if_index_from),
-			      ntohl (mp->sw_if_index_to), mp->state);
+			      ntohl (mp->sw_if_index_to), mp->state,
+			      mp->is_l2 ? SPAN_FEAT_L2 : SPAN_FEAT_DEVICE);
 
   REPLY_MACRO (VL_API_SW_INTERFACE_SPAN_ENABLE_DISABLE_REPLY);
 }
@@ -76,11 +77,14 @@ vl_api_sw_interface_span_dump_t_handler (vl_api_sw_interface_span_dump_t * mp)
 
   /* *INDENT-OFF* */
   vec_foreach (si, sm->interfaces)
-    if (si->num_rx_mirror_ports || si->num_tx_mirror_ports)
+  {
+  span_mirror_t * drxm = &si->mirror_rxtx[SPAN_FEAT_DEVICE][VLIB_RX];
+  span_mirror_t * dtxm = &si->mirror_rxtx[SPAN_FEAT_DEVICE][VLIB_TX];
+    if (drxm->num_mirror_ports || dtxm->num_mirror_ports)
     {
       clib_bitmap_t *b;
       u32 i;
-      b = clib_bitmap_dup_or (si->rx_mirror_ports, si->tx_mirror_ports);
+      b = clib_bitmap_dup_or (drxm->mirror_ports, dtxm->mirror_ports);
       clib_bitmap_foreach (i, b, (
         {
           rmp = vl_msg_api_alloc (sizeof (*rmp));
@@ -90,13 +94,14 @@ vl_api_sw_interface_span_dump_t_handler (vl_api_sw_interface_span_dump_t * mp)
 
           rmp->sw_if_index_from = htonl (si - sm->interfaces);
           rmp->sw_if_index_to = htonl (i);
-          rmp->state = (u8) (clib_bitmap_get (si->rx_mirror_ports, i) +
-                             clib_bitmap_get (si->tx_mirror_ports, i) * 2);
+          rmp->state = (u8) (clib_bitmap_get (drxm->mirror_ports, i) +
+                             clib_bitmap_get (dtxm->mirror_ports, i) * 2);
 
           vl_msg_api_send_shmem (q, (u8 *) & rmp);
         }));
       clib_bitmap_free (b);
     }
+    }
   /* *INDENT-ON* */
 }
 
diff --git a/src/vpp/api/custom_dump.c b/src/vpp/api/custom_dump.c
index 7f3a58d9523..55a362a386b 100644
--- a/src/vpp/api/custom_dump.c
+++ b/src/vpp/api/custom_dump.c
@@ -2227,6 +2227,9 @@ static void *vl_api_sw_interface_span_enable_disable_t_print
   s = format (s, "src_sw_if_index %u ", ntohl (mp->sw_if_index_from));
   s = format (s, "dst_sw_if_index %u ", ntohl (mp->sw_if_index_to));
 
+  if (mp->is_l2)
+    s = format (s, "l2 ");
+
   switch (mp->state)
     {
     case 0: