From 2231150b52b58c4114f8520cde8b26df2761e064 Mon Sep 17 00:00:00 2001
From: Damjan Marion <damarion@cisco.com>
Date: Fri, 28 Oct 2016 20:30:15 +0200
Subject: [PATCH] feature: add new feature handling code and device-input
 features

Signed-off-by: Damjan Marion <damarion@cisco.com>
Change-Id: I010ecde93863dbdad84b993cd3680a5446db59b5
---
 vlib/vlib/node.c                                   |   1 +
 vlib/vlib/node.h                                   |   3 +
 vnet/Makefile.am                                   |  14 +-
 vnet/vnet/buffer.h                                 |   7 +
 vnet/vnet/devices/af_packet/node.c                 |   8 +-
 vnet/vnet/devices/dpdk/node.c                      |   4 +
 vnet/vnet/devices/feature.c                        |  53 ++++
 vnet/vnet/devices/netmap/node.c                    |   8 +-
 vnet/vnet/devices/virtio/vhost-user.c              |   6 +
 vnet/vnet/ethernet/ethernet.h                      |   2 +-
 vnet/vnet/ethernet/interface.c                     |  27 --
 vnet/vnet/feature/feature.c                        | 337 +++++++++++++++++++++
 vnet/vnet/feature/feature.h                        | 208 +++++++++++++
 .../registration.c}                                | 254 +---------------
 vnet/vnet/handoff.c                                |   7 +-
 vnet/vnet/interface_cli.c                          |  17 +-
 vnet/vnet/ip/feature_registration.h                |  63 ----
 vnet/vnet/ip/ip4.h                                 |   2 +-
 vnet/vnet/ip/ip6.h                                 |   2 +-
 vnet/vnet/ip/lookup.h                              |   2 +-
 vnet/vnet/l2/l2_patch.c                            |  11 +-
 vnet/vnet/mpls/mpls_features.c                     |  58 ----
 vnet/vnet/mpls/node.c                              |   1 +
 vnet/vnet/unix/tuntap.c                            |   3 +
 24 files changed, 690 insertions(+), 408 deletions(-)
 create mode 100644 vnet/vnet/devices/feature.c
 create mode 100644 vnet/vnet/feature/feature.c
 create mode 100644 vnet/vnet/feature/feature.h
 rename vnet/vnet/{ip/feature_registration.c => feature/registration.c} (54%)
 delete mode 100644 vnet/vnet/ip/feature_registration.h

diff --git a/vlib/vlib/node.c b/vlib/vlib/node.c
index 23f7ea0239e..118fabe749d 100644
--- a/vlib/vlib/node.c
+++ b/vlib/vlib/node.c
@@ -424,6 +424,7 @@ register_node (vlib_main_t * vm, vlib_node_registration_t * r)
 
     rt->n_next_nodes = r->n_next_nodes;
     rt->next_frame_index = vec_len (nm->next_frames);
+    rt->feature_arc_index = ~0;
 
     vec_resize (nm->next_frames, rt->n_next_nodes);
     for (i = 0; i < rt->n_next_nodes; i++)
diff --git a/vlib/vlib/node.h b/vlib/vlib/node.h
index b624e9d636d..251ee606d20 100644
--- a/vlib/vlib/node.h
+++ b/vlib/vlib/node.h
@@ -465,6 +465,9 @@ typedef struct vlib_node_runtime_t
   /* CPU this node runs on */
   u16 cpu_index;
 
+  /* Index of feature arc in which the node participates */
+  u16 feature_arc_index;
+
   /* Function dependent node-runtime. */
   u8 runtime_data[0];
 }
diff --git a/vnet/Makefile.am b/vnet/Makefile.am
index f35ec1372db..96306dd3ccd 100644
--- a/vnet/Makefile.am
+++ b/vnet/Makefile.am
@@ -266,7 +266,6 @@ nobase_include_HEADERS +=			\
 # Layer 3 protocol: IP v4/v6
 ########################################
 libvnet_la_SOURCES +=				\
- vnet/ip/feature_registration.c			\
  vnet/ip/format.c				\
  vnet/ip/icmp4.c				\
  vnet/ip/icmp6.c				\
@@ -298,7 +297,6 @@ libvnet_la_SOURCES +=				\
  vnet/ip/udp_pg.c
 
 nobase_include_HEADERS +=			\
- vnet/ip/feature_registration.h			\
  vnet/ip/format.h				\
  vnet/ip/icmp46_packet.h			\
  vnet/ip/icmp4.h				\
@@ -718,6 +716,18 @@ nobase_include_HEADERS +=			\
   vnet/devices/netmap/netmap.h
 
 
+########################################
+# Driver feature graph arc support
+########################################
+
+libvnet_la_SOURCES +=				\
+  vnet/devices/feature.c			\
+  vnet/feature/feature.c			\
+  vnet/feature/registration.c
+
+nobase_include_HEADERS +=			\
+  vnet/feature/feature.h
+
 ########################################
 # Unix kernel related
 ########################################
diff --git a/vnet/vnet/buffer.h b/vnet/vnet/buffer.h
index 7aaa6eed9ba..6385f19142c 100644
--- a/vnet/vnet/buffer.h
+++ b/vnet/vnet/buffer.h
@@ -319,6 +319,13 @@ typedef struct
       u16 overlay_afi;
     } lisp;
 
+    /* Driver rx feature */
+    struct
+    {
+      u32 saved_next_index;		/**< saved by drivers for short-cut */
+      u16 buffer_advance;
+    } device_input_feat;
+
     u32 unused[6];
   };
 } vnet_buffer_opaque_t;
diff --git a/vnet/vnet/devices/af_packet/node.c b/vnet/vnet/devices/af_packet/node.c
index 3a3807d8b10..f086b8da1df 100644
--- a/vnet/vnet/devices/af_packet/node.c
+++ b/vnet/vnet/devices/af_packet/node.c
@@ -23,6 +23,7 @@
 #include <vlib/unix/unix.h>
 #include <vnet/ip/ip.h>
 #include <vnet/ethernet/ethernet.h>
+#include <vnet/feature/feature.h>
 
 #include <vnet/devices/af_packet/af_packet.h>
 
@@ -164,7 +165,7 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
   tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
   while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
     {
-      vlib_buffer_t *b0, *first_b0 = 0;
+      vlib_buffer_t *b0 = 0, *first_b0 = 0;
       u32 next0 = next_index;
 
       u32 n_left_to_next;
@@ -236,6 +237,11 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 	      tr->hw_if_index = apif->hw_if_index;
 	      clib_memcpy (&tr->tph, tph, sizeof (struct tpacket2_hdr));
 	    }
+
+	  /* redirect if feature path enabled */
+	  vnet_feature_device_input_redirect_x1 (node, apif->sw_if_index,
+						 &next0, b0, 0);
+
 	  /* enque and take next packet */
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 					   n_left_to_next, first_bi0, next0);
diff --git a/vnet/vnet/devices/dpdk/node.c b/vnet/vnet/devices/dpdk/node.c
index fa651d81787..01a6094e589 100644
--- a/vnet/vnet/devices/dpdk/node.c
+++ b/vnet/vnet/devices/dpdk/node.c
@@ -23,6 +23,7 @@
 #include <vnet/classify/vnet_classify.h>
 #include <vnet/mpls/packet.h>
 #include <vnet/handoff.h>
+#include <vnet/feature/feature.h>
 
 #include "dpdk_priv.h"
 
@@ -530,6 +531,9 @@ dpdk_device_input (dpdk_main_t * dm,
 	   */
 	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
 
+          /* Do we have any driver RX features configured on the interface? */
+	  vnet_feature_device_input_redirect_x1 (node, xd->vlib_sw_if_index, &next0, b0, l3_offset0);
+
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 					   to_next, n_left_to_next,
 					   bi0, next0);
diff --git a/vnet/vnet/devices/feature.c b/vnet/vnet/devices/feature.c
new file mode 100644
index 00000000000..8de78178b26
--- /dev/null
+++ b/vnet/vnet/devices/feature.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/feature/feature.h>
+
+/* *INDENT-OFF* */
+VNET_FEATURE_ARC_INIT (device_input, static) = {
+  .arc_name  = "device-input",
+#if DPDK > 0
+  .start_nodes = VNET_FEATURES ("dpdk-input", "vhost-user-input", "af-packet-input", "netmap-input"),
+#else
+  .start_nodes = VNET_FEATURES ("vhost-user-input", "af-packet-input", "netmap-input"),
+#endif
+};
+
+VNET_FEATURE_INIT (l2_patch, static) = {
+  .arc_name = "device-input",
+  .node_name = "l2-patch",
+  .runs_before = VNET_FEATURES ("ethernet-input"),
+};
+
+VNET_FEATURE_INIT (worker_handoff, static) = {
+  .arc_name = "device-input",
+  .node_name = "worker-handoff",
+  .runs_before = VNET_FEATURES ("ethernet-input"),
+};
+
+VNET_FEATURE_INIT (ethernet_input, static) = {
+  .arc_name = "device-input",
+  .node_name = "ethernet-input",
+  .runs_before = 0, /* not before any other features */
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/vnet/vnet/devices/netmap/node.c b/vnet/vnet/devices/netmap/node.c
index 559db669aae..d13fa1bc7b5 100644
--- a/vnet/vnet/devices/netmap/node.c
+++ b/vnet/vnet/devices/netmap/node.c
@@ -22,6 +22,7 @@
 #include <vlib/vlib.h>
 #include <vlib/unix/unix.h>
 #include <vnet/ethernet/ethernet.h>
+#include <vnet/feature/feature.h>
 
 #include <vnet/devices/netmap/net_netmap.h>
 #include <vnet/devices/netmap/netmap.h>
@@ -158,7 +159,7 @@ netmap_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 
 	  while (r && n_left_to_next)
 	    {
-	      vlib_buffer_t *b0, *first_b0 = 0;
+	      vlib_buffer_t *b0 = 0, *first_b0 = 0;
 	      u32 offset = 0;
 	      u32 bi0 = 0, first_bi0 = 0, prev_bi0;
 	      u32 next_slot_index = (cur_slot_index + 1) % ring->num_slots;
@@ -235,6 +236,11 @@ netmap_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 		      memcpy (&tr->slot, slot, sizeof (struct netmap_slot));
 		    }
 		}
+
+	      /* redirect if feature path enabled */
+	      vnet_feature_device_input_redirect_x1 (node, nif->sw_if_index,
+						     &next0, b0, 0);
+
 	      /* enque and take next packet */
 	      vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 					       n_left_to_next, first_bi0,
diff --git a/vnet/vnet/devices/virtio/vhost-user.c b/vnet/vnet/devices/virtio/vhost-user.c
index 5916ced2570..bdac7c24861 100644
--- a/vnet/vnet/devices/virtio/vhost-user.c
+++ b/vnet/vnet/devices/virtio/vhost-user.c
@@ -36,6 +36,7 @@
 #include <vnet/ip/ip.h>
 
 #include <vnet/ethernet/ethernet.h>
+#include <vnet/feature/feature.h>
 
 #include <vnet/devices/virtio/vhost-user.h>
 
@@ -1290,6 +1291,11 @@ vhost_user_if_input (vlib_main_t * vm,
 	  to_next[0] = bi_head;
 	  to_next++;
 	  n_left_to_next--;
+
+	  /* redirect if feature path enabled */
+	  vnet_feature_device_input_redirect_x1 (node, vui->sw_if_index,
+						 &next0, b_head, 0);
+
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 					   to_next, n_left_to_next,
 					   bi_head, next0);
diff --git a/vnet/vnet/ethernet/ethernet.h b/vnet/vnet/ethernet/ethernet.h
index 11bbd923a93..c31025b7840 100644
--- a/vnet/vnet/ethernet/ethernet.h
+++ b/vnet/vnet/ethernet/ethernet.h
@@ -43,7 +43,7 @@
 #include <vnet/vnet.h>
 #include <vnet/ethernet/packet.h>
 #include <vnet/pg/pg.h>
-#include <vnet/ip/feature_registration.h>
+#include <vnet/feature/feature.h>
 
 always_inline u64
 ethernet_mac_address_u64 (u8 * a)
diff --git a/vnet/vnet/ethernet/interface.c b/vnet/vnet/ethernet/interface.c
index 45d215d324f..a0dea6f52a2 100644
--- a/vnet/vnet/ethernet/interface.c
+++ b/vnet/vnet/ethernet/interface.c
@@ -701,33 +701,6 @@ VLIB_CLI_COMMAND (delete_sub_interface_command, static) = {
 };
 /* *INDENT-ON* */
 
-static clib_error_t *
-show_ethernet_interface_features_command_fn (vlib_main_t * vm,
-					     unformat_input_t * input,
-					     vlib_cli_command_t * cmd)
-{
-  vnet_main_t *vnm = vnet_get_main ();
-  ethernet_main_t *em = &ethernet_main;
-  u32 sw_if_index;
-
-  if (!unformat (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index))
-    return clib_error_return (0, "Interface not specified...");
-
-  vlib_cli_output (vm, "Ethernet feature paths configured on %U...",
-		   format_vnet_sw_if_index_name, vnm, sw_if_index);
-
-  ip_interface_features_show (vm, "Ethernet",
-			      em->feature_config_mains, sw_if_index);
-
-  return 0;
-}
-
-VLIB_CLI_COMMAND (show_ethernet_interface_features_command, static) =
-{
-.path = "show ethernet interface features",.short_help =
-    "show ethernet interface features <intfc>",.function =
-    show_ethernet_interface_features_command_fn,};
-
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/vnet/vnet/feature/feature.c b/vnet/vnet/feature/feature.c
new file mode 100644
index 00000000000..4cfe1faa20f
--- /dev/null
+++ b/vnet/vnet/feature/feature.c
@@ -0,0 +1,337 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/feature/feature.h>
+
+vnet_feature_main_t feature_main;
+
+static clib_error_t *
+vnet_feature_init (vlib_main_t * vm)
+{
+  vnet_feature_main_t *fm = &feature_main;
+  vnet_feature_registration_t *freg;
+  vnet_feature_arc_registration_t *areg;
+  u32 arc_index = 0;
+
+  fm->arc_index_by_name = hash_create_string (0, sizeof (uword));
+  areg = fm->next_arc;
+
+  /* process feature arc registrations */
+  while (areg)
+    {
+      char *s;
+      int i = 0;
+      areg->feature_arc_index = arc_index;
+      hash_set_mem (fm->arc_index_by_name, areg->arc_name,
+		    pointer_to_uword (areg));
+
+      /* process start nodes */
+      while ((s = areg->start_nodes[i]))
+	{
+	  vlib_node_t *n;
+	  vlib_node_runtime_t *rt;
+	  n = vlib_get_node_by_name (vm, (u8 *) s);
+
+	  if (n == 0)
+	    return clib_error_return (0,
+				      "Unknown start node '%s' on feature arc '%s'",
+				      s, areg->arc_name);
+
+	  rt = vlib_node_get_runtime (vm, n->index);
+	  rt->feature_arc_index = arc_index;
+	  i++;
+	}
+      areg->n_start_nodes = i;
+
+      /* next */
+      areg = areg->next;
+      arc_index++;
+    }
+
+  vec_validate (fm->next_feature_by_arc, arc_index - 1);
+  vec_validate (fm->feature_nodes, arc_index - 1);
+  vec_validate (fm->feature_config_mains, arc_index - 1);
+  vec_validate (fm->next_feature_by_name, arc_index - 1);
+  vec_validate (fm->sw_if_index_has_features, arc_index - 1);
+  vec_validate (fm->feature_count_by_sw_if_index, arc_index - 1);
+
+  freg = fm->next_feature;
+  while (freg)
+    {
+      vlib_node_t *n;
+      vlib_node_runtime_t *rt;
+      uword *p = hash_get_mem (fm->arc_index_by_name, freg->arc_name);
+      if (p == 0)
+	return clib_error_return (0, "Unknown feature arc '%s'",
+				  freg->arc_name);
+
+      areg = uword_to_pointer (p[0], vnet_feature_arc_registration_t *);
+      arc_index = areg->feature_arc_index;
+
+      /* set feature arc index in node runtime */
+      n = vlib_get_node_by_name (vm, (u8 *) freg->node_name);
+      if (n == 0)
+	return clib_error_return (0, "Unknown node '%s', freg->node_name");
+      rt = vlib_node_get_runtime (vm, n->index);
+      rt->feature_arc_index = arc_index;
+
+      vec_add1 (fm->next_feature_by_arc[arc_index], *freg);
+
+      /* next */
+      freg = freg->next;
+    }
+
+  while (areg)
+    {
+      clib_error_t *error;
+      vnet_feature_config_main_t *cm;
+      vnet_config_main_t *vcm;
+
+      arc_index = areg->feature_arc_index;
+      cm = &fm->feature_config_mains[arc_index];
+      vcm = &cm->config_main;
+      if ((error = vnet_feature_arc_init (vm, vcm,
+					  areg->start_nodes,
+					  areg->n_start_nodes,
+					  fm->next_feature_by_arc[arc_index],
+					  &fm->feature_nodes[arc_index])))
+	{
+	  return error;
+	}
+
+      fm->next_feature_by_name[arc_index] =
+	hash_create_string (0, sizeof (uword));
+      freg = fm->next_feature_by_arc[arc_index];
+
+      while (freg)
+	{
+	  hash_set_mem (fm->next_feature_by_name[arc_index],
+			freg->node_name, pointer_to_uword (freg));
+	  freg = freg->next;
+	}
+
+      /* next */
+      areg = areg->next;
+      arc_index++;
+    }
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (vnet_feature_init);
+
+void
+vnet_config_update_feature_count (vnet_feature_main_t * fm, u16 arc,
+				  u32 sw_if_index, int is_add)
+{
+  uword bit_value;
+
+  vec_validate (fm->feature_count_by_sw_if_index[arc], sw_if_index);
+
+  fm->feature_count_by_sw_if_index[arc][sw_if_index] += is_add ? 1 : -1;
+
+  ASSERT (fm->feature_count_by_sw_if_index[arc][sw_if_index] >= 0);
+
+  bit_value = fm->feature_count_by_sw_if_index[arc][sw_if_index] > 0;
+
+  fm->sw_if_index_has_features[arc] =
+    clib_bitmap_set (fm->sw_if_index_has_features[arc], sw_if_index,
+		     bit_value);
+}
+
+u16
+vnet_feature_arc_index_from_node_name (const char *s)
+{
+  vnet_feature_main_t *fm = &feature_main;
+  vnet_feature_arc_registration_t *reg;
+  uword *p;
+
+  p = hash_get_mem (fm->arc_index_by_name, s);
+  if (p == 0)
+    return ~0;
+
+  reg = uword_to_pointer (p[0], vnet_feature_arc_registration_t *);
+  return reg->feature_arc_index;
+}
+
+u32
+vnet_feature_index_from_node_name (u16 arc, const char *s)
+{
+  vnet_feature_main_t *fm = &feature_main;
+  vnet_feature_registration_t *reg;
+  uword *p;
+
+  p = hash_get_mem (fm->next_feature_by_name[arc], s);
+  if (p == 0)
+    return ~0;
+
+  reg = uword_to_pointer (p[0], vnet_feature_registration_t *);
+  return reg->feature_index_u32;
+}
+
+void
+vnet_feature_enable_disable (const char *arc_name, const char *node_name,
+			     u32 sw_if_index, int enable_disable,
+			     void *feature_config, u32 n_feature_config_bytes)
+{
+  vnet_feature_main_t *fm = &feature_main;
+  vnet_feature_config_main_t *cm;
+  u32 feature_index, ci;
+  u16 arc_index;
+
+  arc_index = vnet_feature_arc_index_from_node_name (arc_name);
+
+  if (arc_index == ~0)
+    return;
+
+  cm = &fm->feature_config_mains[arc_index];
+  vec_validate_init_empty (cm->config_index_by_sw_if_index, sw_if_index, ~0);
+  feature_index = vnet_feature_index_from_node_name (arc_index, node_name);
+  if (feature_index == ~0)
+    return;
+  ci = cm->config_index_by_sw_if_index[sw_if_index];
+
+  ci = (enable_disable
+	? vnet_config_add_feature
+	: vnet_config_del_feature)
+    (vlib_get_main (), &cm->config_main, ci, feature_index, feature_config,
+     n_feature_config_bytes);
+  cm->config_index_by_sw_if_index[sw_if_index] = ci;
+
+  vnet_config_update_feature_count (fm, arc_index, sw_if_index,
+				    enable_disable);
+
+}
+
+
+/** Display the set of available driver features.
+    Useful for verifying that expected features are present
+*/
+
+static clib_error_t *
+show_features_command_fn (vlib_main_t * vm,
+			  unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+  vnet_feature_main_t *fm = &feature_main;
+  vnet_feature_arc_registration_t *areg;
+  vnet_feature_registration_t *freg;
+
+  vlib_cli_output (vm, "Available feature paths");
+
+  areg = fm->next_arc;
+  while (areg)
+    {
+      vlib_cli_output (vm, "%s:", areg->arc_name);
+      vec_foreach (freg, fm->next_feature_by_arc[areg->feature_arc_index])
+      {
+	vlib_cli_output (vm, "  %s\n", freg->node_name);
+      }
+
+
+      /* next */
+      areg = areg->next;
+    }
+
+  return 0;
+}
+
+/*?
+ * Display the set of available driver features
+ *
+ * @cliexpar
+ * Example:
+ * @cliexcmd{show ip features}
+ * @cliexend
+ * @endparblock
+?*/
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (show_features_command, static) = {
+  .path = "show features",
+  .short_help = "show features",
+  .function = show_features_command_fn,
+};
+/* *INDENT-ON* */
+
+/** Display the set of driver features configured on a specific interface
+  * Called by "show interface" handler
+ */
+
+void
+vnet_interface_features_show (vlib_main_t * vm, u32 sw_if_index)
+{
+  vnet_feature_main_t *fm = &feature_main;
+  u32 node_index, current_config_index;
+  u16 feature_arc;
+  vnet_feature_config_main_t *cm = fm->feature_config_mains;
+  vnet_feature_arc_registration_t *areg;
+  vnet_config_main_t *vcm;
+  vnet_config_t *cfg;
+  u32 cfg_index;
+  vnet_config_feature_t *feat;
+  vlib_node_t *n;
+  int i;
+
+  vlib_cli_output (vm, "Driver feature paths configured on %U...",
+		   format_vnet_sw_if_index_name,
+		   vnet_get_main (), sw_if_index);
+
+  areg = fm->next_arc;
+  while (areg)
+    {
+      feature_arc = areg->feature_arc_index;
+      vcm = &(cm[feature_arc].config_main);
+
+      vlib_cli_output (vm, "\n%s:", areg->arc_name);
+      areg = areg->next;
+
+      if (NULL == cm[feature_arc].config_index_by_sw_if_index ||
+	  vec_len (cm[feature_arc].config_index_by_sw_if_index) < sw_if_index)
+	{
+	  vlib_cli_output (vm, "  none configured");
+	  continue;
+	}
+
+      current_config_index =
+	vec_elt (cm[feature_arc].config_index_by_sw_if_index, sw_if_index);
+
+      if (current_config_index == ~0)
+	{
+	  vlib_cli_output (vm, "  none configured");
+	  continue;
+	}
+
+      ASSERT (current_config_index
+	      < vec_len (vcm->config_pool_index_by_user_index));
+
+      cfg_index = vcm->config_pool_index_by_user_index[current_config_index];
+      cfg = pool_elt_at_index (vcm->config_pool, cfg_index);
+
+      for (i = 0; i < vec_len (cfg->features); i++)
+	{
+	  feat = cfg->features + i;
+	  node_index = feat->node_index;
+	  n = vlib_get_node (vm, node_index);
+	  vlib_cli_output (vm, "  %v", n->name);
+	}
+    }
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/vnet/vnet/feature/feature.h b/vnet/vnet/feature/feature.h
new file mode 100644
index 00000000000..1706dec5456
--- /dev/null
+++ b/vnet/vnet/feature/feature.h
@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef included_features_h
+#define included_features_h
+
+#include <vnet/vnet.h>
+
+/** feature registration object */
+typedef struct _vnet_feature_arc_registration
+{
+  /** next registration in list of all registrations*/
+  struct _vnet_feature_arc_registration *next;
+  /** Feature Arc name */
+  char *arc_name;
+  /** Start nodes */
+  char **start_nodes;
+  int n_start_nodes;
+  /* Feature arc index, assigned by init function */
+  u16 feature_arc_index;
+} vnet_feature_arc_registration_t;
+
+/** feature registration object */
+typedef struct _vnet_feature_registration
+{
+  /** next registration in list of all registrations*/
+  struct _vnet_feature_registration *next;
+  /** Feature arc name */
+  char *arc_name;
+  /** Graph node name */
+  char *node_name;
+  /** Pointer to this feature index, filled in by vnet_feature_arc_init */
+  u32 *feature_index;
+  u32 feature_index_u32;
+  /** Constraints of the form "this feature runs before X" */
+  char **runs_before;
+  /** Constraints of the form "this feature runs after Y" */
+  char **runs_after;
+} vnet_feature_registration_t;
+
+typedef struct vnet_feature_config_main_t_
+{
+  vnet_config_main_t config_main;
+  u32 *config_index_by_sw_if_index;
+} vnet_feature_config_main_t;
+
+typedef struct
+{
+  /** feature arc configuration list */
+  vnet_feature_arc_registration_t *next_arc;
+  uword **arc_index_by_name;
+
+  /** feature path configuration lists */
+  vnet_feature_registration_t *next_feature;
+  vnet_feature_registration_t **next_feature_by_arc;
+  uword **next_feature_by_name;
+
+  /** feature config main objects */
+  vnet_feature_config_main_t *feature_config_mains;
+
+  /** Save partial order results for show command */
+  char ***feature_nodes;
+
+  /** bitmap of interfaces which have driver rx features configured */
+  uword **sw_if_index_has_features;
+
+  /** feature reference counts by interface */
+  i16 **feature_count_by_sw_if_index;
+
+  /** convenience */
+  vlib_main_t *vlib_main;
+  vnet_main_t *vnet_main;
+} vnet_feature_main_t;
+
+extern vnet_feature_main_t feature_main;
+
+#define VNET_FEATURE_ARC_INIT(x,...)				\
+  __VA_ARGS__ vnet_feature_arc_registration_t vnet_feat_arc_##x;\
+static void __vnet_add_feature_arc_registration_##x (void)	\
+  __attribute__((__constructor__)) ;				\
+static void __vnet_add_feature_arc_registration_##x (void)	\
+{								\
+  vnet_feature_main_t * fm = &feature_main;			\
+  vnet_feat_arc_##x.next = fm->next_arc;			\
+  fm->next_arc = & vnet_feat_arc_##x;				\
+}								\
+__VA_ARGS__ vnet_feature_arc_registration_t vnet_feat_arc_##x
+
+#define VNET_FEATURE_INIT(x,...)				\
+  __VA_ARGS__ vnet_feature_registration_t vnet_feat_##x;	\
+static void __vnet_add_feature_registration_##x (void)		\
+  __attribute__((__constructor__)) ;				\
+static void __vnet_add_feature_registration_##x (void)		\
+{								\
+  vnet_feature_main_t * fm = &feature_main;			\
+  vnet_feat_##x.next = fm->next_feature;			\
+  fm->next_feature = & vnet_feat_##x;				\
+}								\
+__VA_ARGS__ vnet_feature_registration_t vnet_feat_##x
+
+void
+vnet_config_update_feature_count (vnet_feature_main_t * fm, u16 arc,
+				  u32 sw_if_index, int is_add);
+
+u32 vnet_feature_index_from_node_name (u16 type, const char *s);
+
+void
+vnet_feature_enable_disable (const char *arc_name, const char *node_name,
+			     u32 sw_if_index, int enable_disable,
+			     void *feature_config,
+			     u32 n_feature_config_bytes);
+
+
+static_always_inline int
+vnet_have_features (u32 arc, u32 sw_if_index)
+{
+  vnet_feature_main_t *fm = &feature_main;
+  return clib_bitmap_get (fm->sw_if_index_has_features[arc], sw_if_index);
+}
+
+static_always_inline u32
+vnet_feature_get_config_index (u16 arc, u32 sw_if_index)
+{
+  vnet_feature_main_t *fm = &feature_main;
+  vnet_feature_config_main_t *cm = &fm->feature_config_mains[arc];
+  return vec_elt (cm->config_index_by_sw_if_index, sw_if_index);
+}
+
+static_always_inline void
+vnet_feature_redirect (u16 arc, u32 sw_if_index, u32 * next0,
+		       vlib_buffer_t * b0)
+{
+  vnet_feature_main_t *fm = &feature_main;
+  vnet_feature_config_main_t *cm = &fm->feature_config_mains[arc];
+
+  if (PREDICT_FALSE (vnet_have_features (arc, sw_if_index)))
+    {
+      b0->current_config_index =
+	vec_elt (cm->config_index_by_sw_if_index, sw_if_index);
+      vnet_get_config_data (&cm->config_main, &b0->current_config_index,
+			    next0, /* # bytes of config data */ 0);
+    }
+}
+
+static_always_inline void
+vnet_feature_device_input_redirect_x1 (vlib_node_runtime_t * node,
+				       u32 sw_if_index, u32 * next0,
+				       vlib_buffer_t * b0,
+				       u16 buffer_advanced0)
+{
+  vnet_feature_main_t *fm = &feature_main;
+  vnet_feature_config_main_t *cm;
+
+  ASSERT (node->feature_arc_index != ~(u16) 0);
+  cm = &fm->feature_config_mains[node->feature_arc_index];
+
+  if (PREDICT_FALSE
+      (clib_bitmap_get
+       (fm->sw_if_index_has_features[node->feature_arc_index], sw_if_index)))
+    {
+      /*
+       * Save next0 so that the last feature in the chain
+       * can skip ethernet-input if indicated...
+       */
+      vnet_buffer (b0)->device_input_feat.saved_next_index = *next0;
+      vnet_buffer (b0)->device_input_feat.buffer_advance = buffer_advanced0;
+      vlib_buffer_advance (b0, -buffer_advanced0);
+
+      b0->current_config_index =
+	vec_elt (cm->config_index_by_sw_if_index, sw_if_index);
+      vnet_get_config_data (&cm->config_main, &b0->current_config_index,
+			    next0, /* # bytes of config data */ 0);
+    }
+}
+
+#define ORDER_CONSTRAINTS (char*[])
+#define VNET_FEATURES(...)  (char*[]) { __VA_ARGS__, 0}
+
+clib_error_t *vnet_feature_arc_init (vlib_main_t * vm,
+				     vnet_config_main_t * vcm,
+				     char **feature_start_nodes,
+				     int num_feature_start_nodes,
+				     vnet_feature_registration_t *
+				     first_reg, char ***feature_nodes);
+
+void vnet_interface_features_show (vlib_main_t * vm, u32 sw_if_index);
+
+#endif /* included_feature_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/vnet/vnet/ip/feature_registration.c b/vnet/vnet/feature/registration.c
similarity index 54%
rename from vnet/vnet/ip/feature_registration.c
rename to vnet/vnet/feature/registration.c
index fd94bf1932c..64a82673b15 100644
--- a/vnet/vnet/ip/feature_registration.c
+++ b/vnet/vnet/feature/registration.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Copyright (c) 2016 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
@@ -19,9 +19,9 @@
 
 /**
  * @file
- * @brief IP Feature Subgraph Ordering.
+ * @brief Feature Subgraph Ordering.
 
-    Dynamically compute IP feature subgraph ordering by performing a
+    Dynamically compute feature subgraph ordering by performing a
     topological sort across a set of "feature A before feature B" and
     "feature C after feature B" constraints.
 
@@ -42,17 +42,17 @@
     feature subgraph arc, which needs to run before @c ip4-lookup.  In
     either base code or a plugin,
     <CODE><PRE>
-    \#include <vnet/ip/feature_registration.h>
+    \#include <vnet/feature/feature.h>
     </PRE></CODE>
 
     and add the new feature as shown:
 
     <CODE><PRE>
-    VNET_IP4_UNICAST_FEATURE_INIT (ip4_lookup, static) =
+    VNET_FEATURE_INIT (ip4_lookup, static) =
     {
+      .arch_name = "ip4-unicast",
       .node_name = "my-ip4-unicast-feature",
-      .runs_before = ORDER_CONSTRAINTS {"ip4-lookup", 0}
-      .feature_index = &my_feature_index,
+      .runs_before = VLIB_FEATURES ("ip4-lookup", 0)
     };
     </PRE></CODE>
 
@@ -60,42 +60,18 @@
     @c my-ip4-unicast-feature on an interface:
 
     <CODE><PRE>
-    ip4_main_t *im = \&ip4_main;
-    ip_lookup_main_t *lm = &im->lookup_main;
-    vnet_feature_config_main_t *rx_cm =
-        &lm->feature_config_mains[VNET_IP_RX_UNICAST_FEAT];
 
     sw_if_index = <interface-handle>
-    ci = rx_cm->config_index_by_sw_if_index[sw_if_index];
-    ci = (is_add
-          ? vnet_config_add_feature
-          : vnet_config_del_feature)
-      (vm, &rx_cm->config_main,
-       ci,
-       my_feature_index,
-       0 / * &config struct if feature uses private config data * /,
-       0 / * sizeof config struct if feature uses private config data * /);
-    rx_cm->config_index_by_sw_if_index[sw_if_index] = ci;
-    </PRE></CODE>
-
-    For tx features, add this line after setting
-    <CODE><PRE>
-    tx_cm->config_index_by_sw_if_index = ci.
-    </PRE></CODE>
-
-    This maintains a
-    per-interface "at least one TX feature enabled" bitmap:
-
-    <CODE><PRE>
-    vnet_config_update_tx_feature_count (lm, tx_cm, sw_if_index, is_add);
+    vnet_feature_enable_disable ("ip4-unicast", "my-ip4-unicast-feature",
+                                 sw_if_index, 1 );
     </PRE></CODE>
 
     Here's how to obtain the correct next node index in packet
     processing code, aka in the implementation of @c my-ip4-unicast-feature:
 
     <CODE><PRE>
-    ip_lookup_main_t * lm = sm->ip4_lookup_main;
-    vnet_feature_config_main_t * cm = &lm->feature_config_mains[VNET_IP_RX_UNICAST_FEAT];
+    vnet_feature_main_t *fm = &feature_main;
+    vnet_feature_config_main_t * cm = &fm->feature_config_mains[VNET_FEAT_IP4_UNICAST];
 
     Call @c vnet_get_config_data to set next0, and to advance
     @c b0->current_config_index:
@@ -111,8 +87,6 @@
     vnet_get_config_data.
 */
 
-static const char *vnet_cast_names[] = VNET_CAST_NAMES;
-
 static int
 comma_split (u8 * s, u8 ** a, u8 ** b)
 {
@@ -292,7 +266,9 @@ again:
       p = hash_get (reg_by_index, result[i]);
       ASSERT (p != 0);
       this_reg = (vnet_feature_registration_t *) p[0];
-      *this_reg->feature_index = n_features - (i + 1);
+      if (this_reg->feature_index)
+	*this_reg->feature_index = n_features - (i + 1);
+      this_reg->feature_index_u32 = n_features - (i + 1);
       vec_add1 (feature_nodes, this_reg->node_name);
     }
 
@@ -323,208 +299,6 @@ again:
   return 0;
 }
 
-#define foreach_af_cast                                 \
-_(4, VNET_IP_RX_UNICAST_FEAT, "ip4 unicast")            \
-_(4, VNET_IP_RX_MULTICAST_FEAT, "ip4 multicast")        \
-_(4, VNET_IP_TX_FEAT, "ip4 output")                     \
-_(6, VNET_IP_RX_UNICAST_FEAT, "ip6 unicast")            \
-_(6, VNET_IP_RX_MULTICAST_FEAT, "ip6 multicast")        \
-_(6, VNET_IP_TX_FEAT, "ip6 output")
-
-/** Display the set of available ip features.
-    Useful for verifying that expected features are present
-*/
-
-static clib_error_t *
-show_ip_features_command_fn (vlib_main_t * vm,
-			     unformat_input_t * input,
-			     vlib_cli_command_t * cmd)
-{
-  ip4_main_t *im4 = &ip4_main;
-  ip6_main_t *im6 = &ip6_main;
-  int i;
-  char **features;
-
-  vlib_cli_output (vm, "Available IP feature nodes");
-
-#define _(a,c,s)                                        \
-  do {                                                  \
-    features = im##a->feature_nodes[c];                 \
-    vlib_cli_output (vm, "%s:", s);                     \
-    for (i = 0; i < vec_len(features); i++)             \
-      vlib_cli_output (vm, "  %s\n", features[i]);      \
-  } while(0);
-  foreach_af_cast;
-#undef _
-
-  return 0;
-}
-
-/*?
- * This command is used to display the set of available IP features.
- * This can be useful for verifying that expected features are present.
- *
- * @cliexpar
- * Example of how to display the set of available IP features:
- * @cliexstart{show ip features}
- * Available IP feature nodes
- * ip4 unicast:
- *   ip4-inacl
- *   ip4-source-check-via-rx
- *   ip4-source-check-via-any
- *   ip4-source-and-port-range-check-rx
- *   ip4-policer-classify
- *   ipsec-input-ip4
- *   vpath-input-ip4
- *   snat-in2out
- *   snat-out2in
- *   ip4-lookup
- * ip4 multicast:
- *   vpath-input-ip4
- *   ip4-lookup-multicast
- * ip4 output:
- *   ip4-source-and-port-range-check-tx
- *   interface-output
- * ip6 unicast:
- *   ip6-inacl
- *   ip6-policer-classify
- *   ipsec-input-ip6
- *   l2tp-decap
- *   vpath-input-ip6
- *   sir-to-ila
- *   ip6-lookup
- * ip6 multicast:
- *   vpath-input-ip6
- *   ip6-lookup
- * ip6 output:
- *   interface-output
- * @cliexend
-?*/
-/* *INDENT-OFF* */
-VLIB_CLI_COMMAND (show_ip_features_command, static) = {
-  .path = "show ip features",
-  .short_help = "show ip features",
-  .function = show_ip_features_command_fn,
-};
-/* *INDENT-ON* */
-
-/** Display the set of IP features configured on a specific interface
- */
-
-void
-ip_interface_features_show (vlib_main_t * vm,
-			    const char *pname,
-			    vnet_feature_config_main_t * cm, u32 sw_if_index)
-{
-  u32 node_index, current_config_index;
-  vnet_cast_t cast;
-  vnet_config_main_t *vcm;
-  vnet_config_t *cfg;
-  u32 cfg_index;
-  vnet_config_feature_t *feat;
-  vlib_node_t *n;
-  int i;
-
-  vlib_cli_output (vm, "%s feature paths configured on %U...",
-		   pname, format_vnet_sw_if_index_name,
-		   vnet_get_main (), sw_if_index);
-
-  for (cast = VNET_IP_RX_UNICAST_FEAT; cast < VNET_N_IP_FEAT; cast++)
-    {
-      vcm = &(cm[cast].config_main);
-
-      vlib_cli_output (vm, "\n%s %s:", pname, vnet_cast_names[cast]);
-
-      if (NULL == cm[cast].config_index_by_sw_if_index ||
-	  vec_len (cm[cast].config_index_by_sw_if_index) < sw_if_index)
-	{
-	  vlib_cli_output (vm, "none configured");
-	  continue;
-	}
-
-      current_config_index = vec_elt (cm[cast].config_index_by_sw_if_index,
-				      sw_if_index);
-
-      ASSERT (current_config_index
-	      < vec_len (vcm->config_pool_index_by_user_index));
-
-      cfg_index = vcm->config_pool_index_by_user_index[current_config_index];
-      cfg = pool_elt_at_index (vcm->config_pool, cfg_index);
-
-      for (i = 0; i < vec_len (cfg->features); i++)
-	{
-	  feat = cfg->features + i;
-	  node_index = feat->node_index;
-	  n = vlib_get_node (vm, node_index);
-	  vlib_cli_output (vm, "  %v", n->name);
-	}
-    }
-}
-
-static clib_error_t *
-show_ip_interface_features_command_fn (vlib_main_t * vm,
-				       unformat_input_t * input,
-				       vlib_cli_command_t * cmd)
-{
-  vnet_main_t *vnm = vnet_get_main ();
-  ip4_main_t *im4 = &ip4_main;
-  ip_lookup_main_t *lm4 = &im4->lookup_main;
-  ip6_main_t *im6 = &ip6_main;
-  ip_lookup_main_t *lm6 = &im6->lookup_main;
-
-  ip_lookup_main_t *lm;
-  u32 sw_if_index, af;
-
-  if (!unformat (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index))
-    return clib_error_return (0, "Interface not specified...");
-
-  vlib_cli_output (vm, "IP feature paths configured on %U...",
-		   format_vnet_sw_if_index_name, vnm, sw_if_index);
-
-  for (af = 0; af < 2; af++)
-    {
-      if (af == 0)
-	lm = lm4;
-      else
-	lm = lm6;
-
-      ip_interface_features_show (vm, (af == 0) ? "ip4" : "ip6",
-				  lm->feature_config_mains, sw_if_index);
-    }
-
-  return 0;
-}
-
-/*?
- * This command is used to display the set of IP features configured
- * on a specific interface
- *
- * @cliexpar
- * Example of how to display the set of available IP features on an interface:
- * @cliexstart{show ip interface features GigabitEthernet2/0/0}
- * IP feature paths configured on GigabitEthernet2/0/0...
- * ipv4 unicast:
- *   ip4-lookup
- * ipv4 multicast:
- *   ip4-lookup-multicast
- * ipv4 multicast:
- *   interface-output
- * ipv6 unicast:
- *   ip6-lookup
- * ipv6 multicast:
- *   ip6-lookup
- * ipv6 multicast:
- *   interface-output
- * @cliexend
-?*/
-/* *INDENT-OFF* */
-VLIB_CLI_COMMAND (show_ip_interface_features_command, static) = {
-  .path = "show ip interface features",
-  .short_help = "show ip interface features <interface>",
-  .function = show_ip_interface_features_command_fn,
-};
-/* *INDENT-ON* */
-
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/vnet/vnet/handoff.c b/vnet/vnet/handoff.c
index 32c665d0c99..5593aa74942 100644
--- a/vnet/vnet/handoff.c
+++ b/vnet/vnet/handoff.c
@@ -18,6 +18,7 @@
 #include <vppinfra/xxhash.h>
 #include <vlib/threads.h>
 #include <vnet/handoff.h>
+#include <vnet/feature/feature.h>
 
 typedef struct
 {
@@ -234,8 +235,7 @@ interface_handoff_enable_disable (vlib_main_t * vm, u32 sw_if_index,
   vnet_sw_interface_t *sw;
   vnet_main_t *vnm = vnet_get_main ();
   per_inteface_handoff_data_t *d;
-  int i, rv;
-  u32 node_index = enable_disable ? worker_handoff_node.index : ~0;
+  int i, rv = 0;
 
   if (pool_is_free_index (vnm->interface_main.sw_interfaces, sw_if_index))
     return VNET_API_ERROR_INVALID_SW_IF_INDEX;
@@ -264,7 +264,8 @@ interface_handoff_enable_disable (vlib_main_t * vm, u32 sw_if_index,
       /* *INDENT-ON* */
     }
 
-  rv = vnet_hw_interface_rx_redirect_to_node (vnm, sw_if_index, node_index);
+  vnet_feature_enable_disable ("device-input", "worker-handoff",
+			       sw_if_index, enable_disable, 0, 0);
   return rv;
 }
 
diff --git a/vnet/vnet/interface_cli.c b/vnet/vnet/interface_cli.c
index 05e650e252c..cd7a620b836 100644
--- a/vnet/vnet/interface_cli.c
+++ b/vnet/vnet/interface_cli.c
@@ -225,12 +225,12 @@ show_sw_interfaces (vlib_main_t * vm,
   vnet_main_t *vnm = vnet_get_main ();
   vnet_interface_main_t *im = &vnm->interface_main;
   vnet_sw_interface_t *si, *sorted_sis = 0;
+  u32 sw_if_index = ~(u32) 0;
   u8 show_addresses = 0;
+  u8 show_features = 0;
 
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
-      u32 sw_if_index;
-
       /* See if user wants to show specific interface */
       if (unformat
 	  (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index))
@@ -240,6 +240,8 @@ show_sw_interfaces (vlib_main_t * vm,
 	}
       else if (unformat (input, "address") || unformat (input, "addr"))
 	show_addresses = 1;
+      else if (unformat (input, "features") || unformat (input, "feat"))
+	show_features = 1;
       else
 	{
 	  error = clib_error_return (0, "unknown input `%U'",
@@ -248,6 +250,15 @@ show_sw_interfaces (vlib_main_t * vm,
 	}
     }
 
+  if (show_features)
+    {
+      if (sw_if_index == ~(u32) 0)
+	return clib_error_return (0, "Interface not specified...");
+
+      vnet_interface_features_show (vm, sw_if_index);
+      return 0;
+    }
+
   if (!show_addresses)
     vlib_cli_output (vm, "%U\n", format_vnet_sw_interface, vnm, 0);
 
@@ -390,7 +401,7 @@ done:
 /* *INDENT-OFF* */
 VLIB_CLI_COMMAND (show_sw_interfaces_command, static) = {
   .path = "show interfaces",
-  .short_help = "show interfaces [address|addr] [<if-name1> <if-name2> ...]",
+  .short_help = "show interfaces [address|addr|features|feat] [<if-name1> <if-name2> ...]",
   .function = show_sw_interfaces,
 };
 /* *INDENT-ON* */
diff --git a/vnet/vnet/ip/feature_registration.h b/vnet/vnet/ip/feature_registration.h
deleted file mode 100644
index fcdd96b61bc..00000000000
--- a/vnet/vnet/ip/feature_registration.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright (c) 2015 Cisco and/or its affiliates.
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef included_feature_registration_h
-#define included_feature_registration_h
-
-/** feature registration object */
-typedef struct _vnet_feature_registration
-{
-  /** next registration in list of all registrations*/
-  struct _vnet_feature_registration *next;
-  /** Graph node name */
-  char *node_name;
-  /** Pointer to this feature index, filled in by vnet_feature_arc_init */
-  u32 *feature_index;
-  /** Constraints of the form "this feature runs before X" */
-  char **runs_before;
-  /** Constraints of the form "this feature runs after Y" */
-  char **runs_after;
-} vnet_feature_registration_t;
-
-typedef struct vnet_feature_config_main_t_
-{
-  vnet_config_main_t config_main;
-  u32 *config_index_by_sw_if_index;
-} vnet_feature_config_main_t;
-
-/** Syntactic sugar, the c-compiler won't initialize registrations without it */
-#define ORDER_CONSTRAINTS (char*[])
-
-clib_error_t *vnet_feature_arc_init (vlib_main_t * vm,
-				     vnet_config_main_t * vcm,
-				     char **feature_start_nodes,
-				     int num_feature_start_nodes,
-				     vnet_feature_registration_t *
-				     first_reg, char ***feature_nodes);
-
-void ip_interface_features_show (vlib_main_t * vm,
-				 const char *pname,
-				 vnet_feature_config_main_t * cm,
-				 u32 sw_if_index);
-
-#endif /* included_feature_registration_h */
-
-/*
- * fd.io coding-style-patch-verification: ON
- *
- * Local Variables:
- * eval: (c-set-style "gnu")
- * End:
- */
diff --git a/vnet/vnet/ip/ip4.h b/vnet/vnet/ip/ip4.h
index f00b6ca7968..f0806c08449 100644
--- a/vnet/vnet/ip/ip4.h
+++ b/vnet/vnet/ip/ip4.h
@@ -43,7 +43,7 @@
 #include <vnet/ip/ip4_mtrie.h>
 #include <vnet/ip/ip4_packet.h>
 #include <vnet/ip/lookup.h>
-#include <vnet/ip/feature_registration.h>
+#include <vnet/feature/feature.h>
 
 typedef struct ip4_fib_t {
   /* Hash table for each prefix length mapping. */
diff --git a/vnet/vnet/ip/ip6.h b/vnet/vnet/ip/ip6.h
index 78546120a23..f6008d71ea1 100644
--- a/vnet/vnet/ip/ip6.h
+++ b/vnet/vnet/ip/ip6.h
@@ -46,7 +46,7 @@
 #include <vnet/ip/ip6_packet.h>
 #include <vnet/ip/ip6_hop_by_hop_packet.h>
 #include <vnet/ip/lookup.h>
-#include <vnet/ip/feature_registration.h>
+#include <vnet/feature/feature.h>
 #include <stdbool.h>
 #include <vppinfra/bihash_24_8.h>
 #include <vppinfra/bihash_template.h>
diff --git a/vnet/vnet/ip/lookup.h b/vnet/vnet/ip/lookup.h
index a1fbe6eb289..c1d8d204ef9 100644
--- a/vnet/vnet/ip/lookup.h
+++ b/vnet/vnet/ip/lookup.h
@@ -54,7 +54,7 @@
 #include <vnet/ip/ip6_packet.h>
 #include <vnet/fib/fib_node.h>
 #include <vnet/dpo/dpo.h>
-#include <vnet/ip/feature_registration.h>
+#include <vnet/feature/feature.h>
 
 /** @brief Common (IP4/IP6) next index stored in adjacency. */
 typedef enum {
diff --git a/vnet/vnet/l2/l2_patch.c b/vnet/vnet/l2/l2_patch.c
index ad05fa0d034..5e4691f45c7 100644
--- a/vnet/vnet/l2/l2_patch.c
+++ b/vnet/vnet/l2/l2_patch.c
@@ -16,6 +16,7 @@
 #include <vnet/vnet.h>
 #include <vnet/pg/pg.h>
 #include <vnet/ethernet/ethernet.h>
+#include <vnet/feature/feature.h>
 #include <vppinfra/error.h>
 
 typedef struct
@@ -283,18 +284,16 @@ VLIB_NODE_FUNCTION_MULTIARCH (l2_patch_node, l2_patch_node_fn)
       ethernet_set_flags (l2pm->vnet_main, rxhi->hw_if_index,
 			  ETHERNET_INTERFACE_FLAG_ACCEPT_ALL);
 
-      vnet_hw_interface_rx_redirect_to_node (l2pm->vnet_main,
-					     rxhi->hw_if_index,
-					     l2_patch_node.index);
+      vnet_feature_enable_disable ("device-input", "l2-patch",
+				   rxhi->hw_if_index, 1, 0, 0);
     }
   else
     {
       ethernet_set_flags (l2pm->vnet_main, rxhi->hw_if_index,
 			  0 /* disable promiscuous mode */ );
 
-      vnet_hw_interface_rx_redirect_to_node (l2pm->vnet_main,
-					     rxhi->hw_if_index,
-					     ~0 /* disable */ );
+      vnet_feature_enable_disable ("device-input", "l2-patch",
+				   rxhi->hw_if_index, 0, 0, 0);
       if (vec_len (l2pm->tx_next_by_rx_sw_if_index) > rx_sw_if_index)
 	{
 	  l2pm->tx_next_by_rx_sw_if_index[rx_sw_if_index] = ~0;
diff --git a/vnet/vnet/mpls/mpls_features.c b/vnet/vnet/mpls/mpls_features.c
index 10a58cfb09c..2f98867cf90 100644
--- a/vnet/vnet/mpls/mpls_features.c
+++ b/vnet/vnet/mpls/mpls_features.c
@@ -213,61 +213,3 @@ VNET_SW_INTERFACE_ADD_DEL_FUNCTION (mpls_sw_interface_add_del);
 _(VNET_IP_RX_UNICAST_FEAT, "mpls input")        \
 _(VNET_IP_TX_FEAT, "mpls output")               \
 
-static clib_error_t *
-show_mpls_features_command_fn (vlib_main_t * vm,
-                               unformat_input_t * input,
-                               vlib_cli_command_t * cmd)
-{
-  mpls_main_t * mm = &mpls_main;
-  int i;
-  char ** features;
-
-  vlib_cli_output (vm, "Available MPLS feature nodes");
-
-#define _(c,s)                                          \
-  do {                                                  \
-    features = mm->feature_nodes[c];                    \
-    vlib_cli_output (vm, "%s:", s);                     \
-    for (i = 0; i < vec_len(features); i++)             \
-      vlib_cli_output (vm, "  %s\n", features[i]);      \
-  } while(0);
-  foreach_af_cast;
-#undef _
-
-  return 0;
-}
-
-VLIB_CLI_COMMAND (show_ip_features_command, static) = {
-  .path = "show mpls features",
-  .short_help = "show mpls features",
-  .function = show_mpls_features_command_fn,
-};
-
-static clib_error_t *
-show_mpls_interface_features_command_fn (vlib_main_t * vm,
-                                         unformat_input_t * input,
-                                         vlib_cli_command_t * cmd)
-{
-  vnet_main_t * vnm = vnet_get_main();
-  u32 sw_if_index;
-
-  if (! unformat (input, "%U", unformat_vnet_sw_interface,
-                  vnm, &sw_if_index))
-    return clib_error_return (0, "Interface not specified...");
-
-  vlib_cli_output (vm, "MPLS feature paths configured on %U...",
-                   format_vnet_sw_if_index_name, vnm, sw_if_index);
-
-  ip_interface_features_show (vm, "MPLS",
-			      mpls_main.feature_config_mains,
-			      sw_if_index);
-
-  return 0;
-}
-
-VLIB_CLI_COMMAND (show_mpls_interface_features_command, static) = {
-  .path = "show mpls interface features",
-  .short_help = "show mpls interface features <intfc>",
-  .function = show_mpls_interface_features_command_fn,
-};
-
diff --git a/vnet/vnet/mpls/node.c b/vnet/vnet/mpls/node.c
index 7a4a302315a..c98b98e733b 100644
--- a/vnet/vnet/mpls/node.c
+++ b/vnet/vnet/mpls/node.c
@@ -18,6 +18,7 @@
 #include <vlib/vlib.h>
 #include <vnet/pg/pg.h>
 #include <vnet/mpls/mpls.h>
+#include <vnet/feature/feature.h>
 
 typedef struct {
   u32 next_index;
diff --git a/vnet/vnet/unix/tuntap.c b/vnet/vnet/unix/tuntap.c
index 89fd1dcfe81..e4d05446e36 100644
--- a/vnet/vnet/unix/tuntap.c
+++ b/vnet/vnet/unix/tuntap.c
@@ -47,6 +47,7 @@
 #include <vnet/ip/ip.h>
 
 #include <vnet/ethernet/ethernet.h>
+#include <vnet/feature/feature.h>
 
 #if DPDK == 1
 #include <vnet/devices/dpdk/dpdk.h>
@@ -395,6 +396,8 @@ tuntap_rx (vlib_main_t * vm,
           next_index = TUNTAP_RX_NEXT_DROP;
       }
 
+    vnet_feature_device_input_redirect_x1 (node, tm->hw_if_index, &next_index, b, 0);
+
     vlib_set_next_frame_buffer (vm, node, next_index, bi);
 
     if (n_trace > 0)
-- 
2.16.6