GBP Endpoint Learning

Learning GBP endpoints over vxlan-gbp tunnels

Change-Id: I1db9fda5a16802d9ad8b4efd4e475614f3b21502
Signed-off-by: Neale Ranns <neale.ranns@cisco.com>

1 files changed, 756 insertions, 0 deletions

diff --git a/src/plugins/gbp/gbp_learn.c b/src/plugins/gbp/gbp_learn.c
new file mode 100644
index 00000000000..9239779dd99
--- /dev/null
+++ b/src/plugins/gbp/gbp_learn.c
@@ -0,0 +1,756 @@
+/*
+ * Copyright (c) 2018 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 <plugins/gbp/gbp.h>
+#include <plugins/gbp/gbp_learn.h>
+#include <plugins/gbp/gbp_bridge_domain.h>
+#include <vlibmemory/api.h>
+
+#include <vnet/util/throttle.h>
+#include <vnet/l2/l2_input.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/vxlan-gbp/vxlan_gbp_packet.h>
+
+/**
+ * Grouping of global data for the GBP source EPG classification feature
+ */
+typedef struct gbp_learn_main_t_
+{
+  /**
+   * Next nodes for L2 output features
+   */
+  u32 gl_l2_input_feat_next[32];
+
+  /**
+   * logger - VLIB log class
+   */
+  vlib_log_class_t gl_logger;
+
+  /**
+   * throttles for the DP leanring
+   */
+  throttle_t gl_l2_throttle;
+  throttle_t gl_l3_throttle;
+} gbp_learn_main_t;
+
+/**
+ * The maximum learning rate per-hashed EP
+ */
+#define GBP_ENDPOINT_HASH_LEARN_RATE (1e-2)
+
+static gbp_learn_main_t gbp_learn_main;
+
+#define GBP_LEARN_DBG(...)                                      \
+    vlib_log_debug (gbp_learn_main.gl_logger, __VA_ARGS__);
+
+#define foreach_gbp_learn                      \
+  _(DROP,    "drop")
+
+typedef enum
+{
+#define _(sym,str) GBP_LEARN_ERROR_##sym,
+  foreach_gbp_learn
+#undef _
+    GBP_LEARN_N_ERROR,
+} gbp_learn_error_t;
+
+static char *gbp_learn_error_strings[] = {
+#define _(sym,string) string,
+  foreach_gbp_learn
+#undef _
+};
+
+typedef enum
+{
+#define _(sym,str) GBP_LEARN_NEXT_##sym,
+  foreach_gbp_learn
+#undef _
+    GBP_LEARN_N_NEXT,
+} gbp_learn_next_t;
+
+typedef struct gbp_learn_l2_t_
+{
+  ip46_address_t ip;
+  mac_address_t mac;
+  u32 sw_if_index;
+  u32 bd_index;
+  epg_id_t epg;
+  ip46_address_t outer_src;
+  ip46_address_t outer_dst;
+} gbp_learn_l2_t;
+
+
+static void
+gbp_learn_l2_cp (const gbp_learn_l2_t * gl2)
+{
+  ip46_address_t *ips = NULL;
+
+  GBP_LEARN_DBG ("L2 EP: %U %U, %d",
+		 format_mac_address_t, &gl2->mac,
+		 format_ip46_address, &gl2->ip, IP46_TYPE_ANY, gl2->epg);
+
+  vec_add1 (ips, gl2->ip);
+
+  ASSERT (!ip46_address_is_zero (&gl2->outer_src));
+  ASSERT (!ip46_address_is_zero (&gl2->outer_dst));
+
+  /*
+   * flip the source and dst, since that's how it was received, this API
+   * takes how it's sent
+   */
+  gbp_endpoint_update (gl2->sw_if_index, ips,
+		       &gl2->mac, gl2->epg,
+		       (GBP_ENDPOINT_FLAG_LEARNT |
+			GBP_ENDPOINT_FLAG_REMOTE),
+		       &gl2->outer_dst, &gl2->outer_src, NULL);
+}
+
+static void
+gbp_learn_l2_ip4_dp (const u8 * mac, const ip4_address_t * ip,
+		     u32 bd_index, u32 sw_if_index, epg_id_t epg,
+		     const ip4_address_t * outer_src,
+		     const ip4_address_t * outer_dst)
+{
+  gbp_learn_l2_t gl2 = {
+    .sw_if_index = sw_if_index,
+    .bd_index = bd_index,
+    .epg = epg,
+    .ip.ip4 = *ip,
+    .outer_src.ip4 = *outer_src,
+    .outer_dst.ip4 = *outer_dst,
+  };
+  mac_address_from_bytes (&gl2.mac, mac);
+
+  ASSERT (!ip46_address_is_zero (&gl2.outer_src));
+  ASSERT (!ip46_address_is_zero (&gl2.outer_dst));
+
+  vl_api_rpc_call_main_thread (gbp_learn_l2_cp, (u8 *) & gl2, sizeof (gl2));
+}
+
+static void
+gbp_learn_l2_ip6_dp (const u8 * mac, const ip6_address_t * ip,
+		     u32 bd_index, u32 sw_if_index, epg_id_t epg,
+		     const ip4_address_t * outer_src,
+		     const ip4_address_t * outer_dst)
+{
+  gbp_learn_l2_t gl2 = {
+    .sw_if_index = sw_if_index,
+    .bd_index = bd_index,
+    .epg = epg,
+    .ip.ip6 = *ip,
+    .outer_src.ip4 = *outer_src,
+    .outer_dst.ip4 = *outer_dst,
+  };
+  mac_address_from_bytes (&gl2.mac, mac);
+
+  vl_api_rpc_call_main_thread (gbp_learn_l2_cp, (u8 *) & gl2, sizeof (gl2));
+}
+
+static void
+gbp_learn_l2_dp (const u8 * mac, u32 bd_index, u32 sw_if_index,
+		 epg_id_t epg,
+		 const ip4_address_t * outer_src,
+		 const ip4_address_t * outer_dst)
+{
+  gbp_learn_l2_t gl2 = {
+    .sw_if_index = sw_if_index,
+    .bd_index = bd_index,
+    .epg = epg,
+    .outer_src.ip4 = *outer_src,
+    .outer_dst.ip4 = *outer_dst,
+  };
+  mac_address_from_bytes (&gl2.mac, mac);
+
+  vl_api_rpc_call_main_thread (gbp_learn_l2_cp, (u8 *) & gl2, sizeof (gl2));
+}
+
+/**
+ * per-packet trace data
+ */
+typedef struct gbp_learn_l2_trace_t_
+{
+  /* per-pkt trace data */
+  mac_address_t mac;
+  u32 sw_if_index;
+  u32 new;
+  u32 throttled;
+  u32 epg;
+  u32 d_bit;
+} gbp_learn_l2_trace_t;
+
+always_inline void
+gbp_learn_get_outer (const ethernet_header_t * eh0,
+		     ip4_address_t * outer_src, ip4_address_t * outer_dst)
+{
+  ip4_header_t *ip0;
+  u8 *buff;
+
+  /* rewind back to the ivxlan header */
+  buff = (u8 *) eh0;
+  buff -= (sizeof (vxlan_gbp_header_t) +
+	   sizeof (udp_header_t) + sizeof (ip4_header_t));
+
+  ip0 = (ip4_header_t *) buff;
+
+  *outer_src = ip0->src_address;
+  *outer_dst = ip0->dst_address;
+}
+
+static uword
+gbp_learn_l2 (vlib_main_t * vm,
+	      vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  u32 n_left_from, *from, *to_next, next_index, thread_index, seed;
+  gbp_learn_main_t *glm;
+  f64 time_now;
+
+  glm = &gbp_learn_main;
+  next_index = 0;
+  n_left_from = frame->n_vectors;
+  from = vlib_frame_vector_args (frame);
+  time_now = vlib_time_now (vm);
+  thread_index = vm->thread_index;
+
+  seed = throttle_seed (&glm->gl_l2_throttle, thread_index, time_now);
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  ip4_address_t outer_src, outer_dst;
+	  u32 bi0, sw_if_index0, t0, epg0;
+	  const ethernet_header_t *eh0;
+	  gbp_learn_next_t next0;
+	  gbp_endpoint_t *ge0;
+	  vlib_buffer_t *b0;
+
+	  next0 = GBP_LEARN_NEXT_DROP;
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+
+	  eh0 = vlib_buffer_get_current (b0);
+	  epg0 = vnet_buffer2 (b0)->gbp.src_epg;
+
+	  next0 = vnet_l2_feature_next (b0, glm->gl_l2_input_feat_next,
+					L2INPUT_FEAT_GBP_LEARN);
+
+	  ge0 = gbp_endpoint_find_mac (eh0->src_address,
+				       vnet_buffer (b0)->l2.bd_index);
+
+	  if (vnet_buffer2 (b0)->gbp.flags & VXLAN_GBP_GPFLAGS_D)
+	    {
+	      ge0 = NULL;
+	      t0 = 1;
+	      goto trace;
+	    }
+
+	  /*
+	   * check for new EP or a moved EP
+	   */
+	  if (NULL == ge0 || ge0->ge_sw_if_index != sw_if_index0)
+
+	    {
+	      /*
+	       * use the last 4 bytes of the mac address as the hash for the EP
+	       */
+	      t0 = throttle_check (&glm->gl_l2_throttle, thread_index,
+				   *((u32 *) (eh0->src_address + 2)), seed);
+	      if (!t0)
+		{
+		  gbp_learn_get_outer (eh0, &outer_src, &outer_dst);
+
+		  switch (clib_net_to_host_u16 (eh0->type))
+		    {
+		    case ETHERNET_TYPE_IP4:
+		      {
+			const ip4_header_t *ip0;
+
+			ip0 = (ip4_header_t *) (eh0 + 1);
+
+			gbp_learn_l2_ip4_dp (eh0->src_address,
+					     &ip0->src_address,
+					     vnet_buffer (b0)->l2.bd_index,
+					     sw_if_index0, epg0,
+					     &outer_src, &outer_dst);
+
+			break;
+		      }
+		    case ETHERNET_TYPE_IP6:
+		      {
+			const ip6_header_t *ip0;
+
+			ip0 = (ip6_header_t *) (eh0 + 1);
+
+			gbp_learn_l2_ip6_dp (eh0->src_address,
+					     &ip0->src_address,
+					     vnet_buffer (b0)->l2.bd_index,
+					     sw_if_index0, epg0,
+					     &outer_src, &outer_dst);
+
+			break;
+		      }
+		    default:
+		      gbp_learn_l2_dp (eh0->src_address,
+				       vnet_buffer (b0)->l2.bd_index,
+				       sw_if_index0, epg0,
+				       &outer_src, &outer_dst);
+		      break;
+		    }
+		}
+	    }
+	  else
+	    {
+	      /*
+	       * this update could happen simultaneoulsy from multiple workers
+	       * but that's ok we are not interested in being very accurate.
+	       */
+	      t0 = 0;
+	      ge0->ge_last_time = time_now;
+	    }
+	trace:
+	  if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      gbp_learn_l2_trace_t *t =
+		vlib_add_trace (vm, node, b0, sizeof (*t));
+	      clib_memcpy (t->mac.bytes, eh0->src_address, 6);
+	      t->new = (NULL == ge0);
+	      t->throttled = t0;
+	      t->sw_if_index = sw_if_index0;
+	      t->epg = epg0;
+	      t->d_bit = ! !(vnet_buffer2 (b0)->gbp.flags &
+			     VXLAN_GBP_GPFLAGS_D);
+	    }
+
+	  /* verify speculative enqueue, maybe switch current next frame */
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  return frame->n_vectors;
+}
+
+/* packet trace format function */
+static u8 *
+format_gbp_learn_l2_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  gbp_learn_l2_trace_t *t = va_arg (*args, gbp_learn_l2_trace_t *);
+
+  s = format (s, "new:%d throttled:%d d-bit:%d mac:%U itf:%d epg:%d",
+	      t->new, t->throttled, t->d_bit,
+	      format_mac_address_t, &t->mac, t->sw_if_index, t->epg);
+
+  return s;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (gbp_learn_l2_node) = {
+  .function = gbp_learn_l2,
+  .name = "gbp-learn-l2",
+  .vector_size = sizeof (u32),
+  .format_trace = format_gbp_learn_l2_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+
+  .n_errors = ARRAY_LEN(gbp_learn_error_strings),
+  .error_strings = gbp_learn_error_strings,
+
+  .n_next_nodes = GBP_LEARN_N_NEXT,
+
+  .next_nodes = {
+    [GBP_LEARN_NEXT_DROP] = "error-drop",
+  },
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (gbp_learn_l2_node, gbp_learn_l2);
+/* *INDENT-ON* */
+
+typedef struct gbp_learn_l3_t_
+{
+  ip46_address_t ip;
+  u32 fib_index;
+  u32 sw_if_index;
+  epg_id_t epg;
+  ip46_address_t outer_src;
+  ip46_address_t outer_dst;
+} gbp_learn_l3_t;
+
+static void
+gbp_learn_l3_cp (const gbp_learn_l3_t * gl3)
+{
+  ip46_address_t *ips = NULL;
+
+  GBP_LEARN_DBG ("L3 EP: %U, %d", format_ip46_address, &gl3->ip,
+		 IP46_TYPE_ANY, gl3->epg);
+
+  vec_add1 (ips, gl3->ip);
+
+  gbp_endpoint_update (gl3->sw_if_index, ips, NULL, gl3->epg,
+		       (GBP_ENDPOINT_FLAG_REMOTE |
+			GBP_ENDPOINT_FLAG_LEARNT),
+		       &gl3->outer_dst, &gl3->outer_src, NULL);
+}
+
+static void
+gbp_learn_ip4_dp (const ip4_address_t * ip,
+		  u32 fib_index, u32 sw_if_index, epg_id_t epg,
+		  const ip4_address_t * outer_src,
+		  const ip4_address_t * outer_dst)
+{
+  /* *INDENT-OFF* */
+  gbp_learn_l3_t gl3 = {
+    .ip = {
+      .ip4 = *ip,
+    },
+    .sw_if_index = sw_if_index,
+    .fib_index = fib_index,
+    .epg = epg,
+    .outer_src.ip4 = *outer_src,
+    .outer_dst.ip4 = *outer_dst,
+  };
+  /* *INDENT-ON* */
+
+  vl_api_rpc_call_main_thread (gbp_learn_l3_cp, (u8 *) & gl3, sizeof (gl3));
+}
+
+static void
+gbp_learn_ip6_dp (const ip6_address_t * ip,
+		  u32 fib_index, u32 sw_if_index, epg_id_t epg,
+		  const ip4_address_t * outer_src,
+		  const ip4_address_t * outer_dst)
+{
+  /* *INDENT-OFF* */
+  gbp_learn_l3_t gl3 = {
+    .ip = {
+      .ip6 = *ip,
+    },
+    .sw_if_index = sw_if_index,
+    .fib_index = fib_index,
+    .epg = epg,
+    .outer_src.ip4 = *outer_src,
+    .outer_dst.ip4 = *outer_dst,
+  };
+  /* *INDENT-ON* */
+
+  vl_api_rpc_call_main_thread (gbp_learn_l3_cp, (u8 *) & gl3, sizeof (gl3));
+}
+
+/**
+ * per-packet trace data
+ */
+typedef struct gbp_learn_l3_trace_t_
+{
+  /* per-pkt trace data */
+  ip46_address_t ip;
+  u32 sw_if_index;
+  u32 new;
+  u32 throttled;
+  u32 epg;
+} gbp_learn_l3_trace_t;
+
+static uword
+gbp_learn_l3 (vlib_main_t * vm,
+	      vlib_node_runtime_t * node, vlib_frame_t * frame,
+	      fib_protocol_t fproto)
+{
+  u32 n_left_from, *from, *to_next, next_index, thread_index, seed;
+  gbp_learn_main_t *glm;
+  f64 time_now;
+
+  glm = &gbp_learn_main;
+  next_index = 0;
+  n_left_from = frame->n_vectors;
+  from = vlib_frame_vector_args (frame);
+  time_now = vlib_time_now (vm);
+  thread_index = vm->thread_index;
+
+  seed = throttle_seed (&glm->gl_l3_throttle, thread_index, time_now);
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0, sw_if_index0, t0, epg0, fib_index0;
+	  CLIB_UNUSED (const ip4_header_t *) ip4_0;
+	  CLIB_UNUSED (const ip6_header_t *) ip6_0;
+	  ip4_address_t outer_src, outer_dst;
+	  ethernet_header_t *eth0;
+	  gbp_learn_next_t next0;
+	  gbp_endpoint_t *ge0;
+	  vlib_buffer_t *b0;
+
+	  next0 = GBP_LEARN_NEXT_DROP;
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+	  epg0 = vnet_buffer2 (b0)->gbp.src_epg;
+	  ip6_0 = NULL;
+	  ip4_0 = NULL;
+
+	  vnet_feature_next (&next0, b0);
+
+	  if (vnet_buffer2 (b0)->gbp.flags & VXLAN_GBP_GPFLAGS_D)
+	    {
+	      t0 = 1;
+	      ge0 = NULL;
+	      goto trace;
+	    }
+
+	  fib_index0 = fib_table_get_index_for_sw_if_index (fproto,
+							    sw_if_index0);
+
+	  if (FIB_PROTOCOL_IP6 == fproto)
+	    {
+	      ip6_0 = vlib_buffer_get_current (b0);
+	      eth0 = (ethernet_header_t *) (((u8 *) ip6_0) - sizeof (*eth0));
+
+	      gbp_learn_get_outer (eth0, &outer_src, &outer_dst);
+
+	      ge0 = gbp_endpoint_find_ip6 (&ip6_0->src_address, fib_index0);
+
+	      if (NULL == ge0)
+		{
+		  t0 = throttle_check (&glm->gl_l3_throttle,
+				       thread_index,
+				       ip6_address_hash_to_u32
+				       (&ip6_0->src_address), seed);
+
+		  if (!t0)
+		    {
+		      gbp_learn_ip6_dp (&ip6_0->src_address,
+					fib_index0, sw_if_index0, epg0,
+					&outer_src, &outer_dst);
+		    }
+		}
+	      else
+		{
+		  /*
+		   * this update could happen simultaneoulsy from multiple
+		   * workers but that's ok we are not interested in being
+		   * very accurate.
+		   */
+		  t0 = 0;
+		  ge0->ge_last_time = time_now;
+		}
+	    }
+	  else
+	    {
+	      ip4_0 = vlib_buffer_get_current (b0);
+	      eth0 = (ethernet_header_t *) (((u8 *) ip4_0) - sizeof (*eth0));
+
+	      gbp_learn_get_outer (eth0, &outer_src, &outer_dst);
+	      ge0 = gbp_endpoint_find_ip4 (&ip4_0->src_address, fib_index0);
+
+	      if (NULL == ge0)
+		{
+		  t0 = throttle_check (&glm->gl_l3_throttle, thread_index,
+				       ip4_0->src_address.as_u32, seed);
+
+		  if (!t0)
+		    {
+		      gbp_learn_ip4_dp (&ip4_0->src_address,
+					fib_index0, sw_if_index0, epg0,
+					&outer_src, &outer_dst);
+		    }
+		}
+	      else
+		{
+		  /*
+		   * this update could happen simultaneoulsy from multiple
+		   * workers but that's ok we are not interested in being
+		   * very accurate.
+		   */
+		  t0 = 0;
+		  ge0->ge_last_time = time_now;
+		}
+	    }
+	trace:
+	  if (PREDICT_FALSE ((b0->flags & VLIB_BUFFER_IS_TRACED)))
+	    {
+	      gbp_learn_l3_trace_t *t;
+
+	      t = vlib_add_trace (vm, node, b0, sizeof (*t));
+	      if (FIB_PROTOCOL_IP6 == fproto && ip6_0)
+		ip46_address_set_ip6 (&t->ip, &ip6_0->src_address);
+	      if (FIB_PROTOCOL_IP4 == fproto && ip4_0)
+		ip46_address_set_ip4 (&t->ip, &ip4_0->src_address);
+	      t->new = (NULL == ge0);
+	      t->throttled = t0;
+	      t->sw_if_index = sw_if_index0;
+	      t->epg = epg0;
+	    }
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  return frame->n_vectors;
+}
+
+/* packet trace format function */
+static u8 *
+format_gbp_learn_l3_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  gbp_learn_l3_trace_t *t = va_arg (*args, gbp_learn_l3_trace_t *);
+
+  s = format (s, "new:%d throttled:%d ip:%U itf:%d epg:%d",
+	      t->new, t->throttled,
+	      format_ip46_address, &t->ip, IP46_TYPE_ANY, t->sw_if_index,
+	      t->epg);
+
+  return s;
+}
+
+static uword
+gbp_learn_ip4 (vlib_main_t * vm,
+	       vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  return (gbp_learn_l3 (vm, node, frame, FIB_PROTOCOL_IP4));
+}
+
+static uword
+gbp_learn_ip6 (vlib_main_t * vm,
+	       vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  return (gbp_learn_l3 (vm, node, frame, FIB_PROTOCOL_IP6));
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (gbp_learn_ip4_node) = {
+  .function = gbp_learn_ip4,
+  .name = "gbp-learn-ip4",
+  .vector_size = sizeof (u32),
+  .format_trace = format_gbp_learn_l3_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (gbp_learn_ip4_node, gbp_learn_ip4);
+
+VNET_FEATURE_INIT (gbp_learn_ip4, static) =
+{
+  .arc_name = "ip4-unicast",
+  .node_name = "gbp-learn-ip4",
+};
+
+VLIB_REGISTER_NODE (gbp_learn_ip6_node) = {
+  .function = gbp_learn_ip6,
+  .name = "gbp-learn-ip6",
+  .vector_size = sizeof (u32),
+  .format_trace = format_gbp_learn_l3_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (gbp_learn_ip6_node, gbp_learn_ip6);
+
+VNET_FEATURE_INIT (gbp_learn_ip6, static) =
+{
+  .arc_name = "ip6-unicast",
+  .node_name = "gbp-learn-ip6",
+};
+
+/* *INDENT-ON* */
+
+void
+gbp_learn_enable (u32 sw_if_index, gbb_learn_mode_t mode)
+{
+  if (GBP_LEARN_MODE_L2 == mode)
+    l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_GBP_LEARN, 1);
+  else
+    {
+      vnet_feature_enable_disable ("ip4-unicast",
+				   "gbp-learn-ip4", sw_if_index, 1, 0, 0);
+      vnet_feature_enable_disable ("ip6-unicast",
+				   "gbp-learn-ip6", sw_if_index, 1, 0, 0);
+    }
+}
+
+void
+gbp_learn_disable (u32 sw_if_index, gbb_learn_mode_t mode)
+{
+  if (GBP_LEARN_MODE_L2 == mode)
+    l2input_intf_bitmap_enable (sw_if_index, L2INPUT_FEAT_GBP_LEARN, 0);
+  else
+    {
+      vnet_feature_enable_disable ("ip4-unicast",
+				   "gbp-learn-ip4", sw_if_index, 0, 0, 0);
+      vnet_feature_enable_disable ("ip6-unicast",
+				   "gbp-learn-ip6", sw_if_index, 0, 0, 0);
+    }
+}
+
+static clib_error_t *
+gbp_learn_init (vlib_main_t * vm)
+{
+  gbp_learn_main_t *glm = &gbp_learn_main;
+  vlib_thread_main_t *tm = &vlib_thread_main;
+
+  /* Initialize the feature next-node indices */
+  feat_bitmap_init_next_nodes (vm,
+			       gbp_learn_l2_node.index,
+			       L2INPUT_N_FEAT,
+			       l2input_get_feat_names (),
+			       glm->gl_l2_input_feat_next);
+
+  throttle_init (&glm->gl_l2_throttle,
+		 tm->n_vlib_mains, GBP_ENDPOINT_HASH_LEARN_RATE);
+
+  throttle_init (&glm->gl_l3_throttle,
+		 tm->n_vlib_mains, GBP_ENDPOINT_HASH_LEARN_RATE);
+
+  glm->gl_logger = vlib_log_register_class ("gbp", "learn");
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (gbp_learn_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */