path: root/hicn-plugin/src/route.c

/*
 * Copyright (c) 2021 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/fib/fib_entry.h>
#include <vnet/fib/fib_table.h>
#include <vnet/fib/fib_entry_track.h>
#include <vnet/ip/ip6_packet.h>
#include <vnet/ip/ip.h>
#include <vnet/dpo/dpo.h>
#include <vnet/dpo/drop_dpo.h>
#include <vnet/dpo/load_balance.h>
#include <vnet/udp/udp.h>
#include <vnet/udp/udp_encap.h>
#include <vlib/global_funcs.h>

#include "strategy_dpo_ctx.h"
#include "strategy_dpo_manager.h"
#include "strategy.h"
#include "faces/face.h"
#include "error.h"
#include "strategies/dpo_mw.h"
#include "infra.h"
#include "udp_tunnels/udp_tunnel.h"
#include "mapme.h"
#include "pg.h"

#define FIB_SOURCE_HICN 0x04 // Right after the FIB_SOURCE_INTERFACE priority

fib_source_t hicn_fib_src;

fib_node_type_t hicn_fib_node_type;

ip4_address_t localhost4 = { 0 };
ip6_address_t localhost6 = { 0 };

int
hicn_route_get_dpo (const fib_prefix_t *prefix, const dpo_id_t **hicn_dpo,
		    u32 *fib_index)
{
  // fib_prefix_t fib_pfx;
  const dpo_id_t *load_balance_dpo_id;
  const dpo_id_t *former_dpo_id;
  int found = 0, ret = HICN_ERROR_ROUTE_NOT_FOUND;
  fib_node_index_t fib_entry_index;

  /* Check if the route already exist in the fib */
  /*
   * ASSUMPTION: we use table 0 which is the default table and it is
   * already existing and locked
   */
  *fib_index = fib_table_find_or_create_and_lock (
    prefix->fp_proto, HICN_FIB_TABLE, hicn_fib_src);
  fib_entry_index = fib_table_lookup_exact_match (*fib_index, prefix);

  if (fib_entry_index != FIB_NODE_INDEX_INVALID)
    {
      /* Route already existing. We need to update the dpo. */
      load_balance_dpo_id =
	fib_entry_contribute_ip_forwarding (fib_entry_index);

      /* The dpo is not a load balance dpo as expected */
      if (load_balance_dpo_id->dpoi_type != DPO_LOAD_BALANCE)
	ret = HICN_ERROR_ROUTE_NO_LD;
      else
	{
	  /* former_dpo_id is a load_balance dpo */
	  load_balance_t *lb =
	    load_balance_get (load_balance_dpo_id->dpoi_index);

	  /* FIB entry exists but there is no hicn dpo. */
	  ret = HICN_ERROR_ROUTE_DPO_NO_HICN;
	  for (int i = 0; i < lb->lb_n_buckets && !found; i++)
	    {
	      former_dpo_id = load_balance_get_bucket_i (lb, i);

	      if (dpo_is_hicn (former_dpo_id))
		{
		  *hicn_dpo = former_dpo_id;
		  ret = HICN_ERROR_NONE;
		  found = 1;
		}
	    }
	}
    }
  /*
   * Remove the lock from the table. We keep one lock per route, not
   * per dpo
   */
  fib_table_unlock (*fib_index, prefix->fp_proto, hicn_fib_src);

  return ret;
}

int
hicn_route_set_strategy (fib_prefix_t *prefix, u8 strategy_id)
{
  const dpo_id_t *hicn_dpo_id;
  int ret;
  hicn_dpo_ctx_t *hicn_dpo_ctx;
  u32 fib_index;

  ret = hicn_route_get_dpo (prefix, &hicn_dpo_id, &fib_index);

  if (ret == HICN_ERROR_NONE)
    {
      hicn_dpo_ctx = hicn_strategy_dpo_ctx_get (hicn_dpo_id->dpoi_index);
      const hicn_dpo_vft_t *dpo_vft = hicn_dpo_get_vft_from_id (strategy_id);

      if (hicn_dpo_ctx == NULL || dpo_vft == NULL)
	return HICN_ERROR_STRATEGY_NOT_FOUND;

      dpo_vft->hicn_dpo_update_type (hicn_dpo_ctx);
    }
  // Remember to remove the lock from the table when removing the entry
  return ret;
}

static int
ip_nh_add_del_helper (fib_protocol_t fib_proto, const fib_prefix_t *rpfx,
		      ip46_address_t *nh, u32 sw_if, u32 udp_encap_id,
		      dpo_proto_t proto, u8 is_add)
{
  fib_route_path_t *rpaths = NULL, rpath;

  u32 fib_index = fib_table_find (fib_proto, 0);
  clib_memset (&rpath, 0, sizeof (rpath));

  if (nh)
    {
      rpath.frp_addr = *nh;
      rpath.frp_sw_if_index = sw_if;
    }
  else if (udp_encap_id != ~0)
    {
      rpath.frp_udp_encap_id = udp_encap_id;
      rpath.frp_flags |= FIB_ROUTE_PATH_UDP_ENCAP;
    }

  rpath.frp_weight = 1;
  rpath.frp_proto = proto;

  vec_add1 (rpaths, rpath);

  if (is_add)
    fib_table_entry_path_add2 (fib_index, rpfx, FIB_SOURCE_API,
			       FIB_ENTRY_FLAG_NONE, rpaths);
  else
    fib_table_entry_path_remove2 (fib_index, rpfx, FIB_SOURCE_API, rpaths);

  return 0;
}

int
ip_nh_adj_add_del_helper (fib_protocol_t fib_proto, const fib_prefix_t *rpfx,
			  ip46_address_t *nh, u32 sw_if, u8 is_add)
{
  return ip_nh_add_del_helper (
    fib_proto, rpfx, nh, sw_if, ~0,
    ip46_address_is_ip4 (nh) ? DPO_PROTO_IP4 : DPO_PROTO_IP6, is_add);
}

int
ip_nh_udp_tunnel_add_del_helper (fib_protocol_t fib_proto,
				 const fib_prefix_t *rpfx, u32 uei,
				 dpo_proto_t proto, u8 is_add)
{
  return ip_nh_add_del_helper (fib_proto, rpfx, NULL, ~0, uei, proto, is_add);
}

static ip46_address_t *
get_address (ip46_address_t *nh, u32 sw_if, fib_protocol_t proto)
{
  ip46_address_t *local_address = calloc (1, sizeof (ip46_address_t));

  if (proto == FIB_PROTOCOL_IP4)
    {
      ip_interface_address_t *interface_address;
      ip4_address_t *addr = ip4_interface_address_matching_destination (
	&ip4_main, &nh->ip4, sw_if, &interface_address);

      if (addr == NULL)
	addr =
	  ip4_interface_first_address (&ip4_main, sw_if, &interface_address);
      if (addr != NULL)
	ip46_address_set_ip4 (local_address, addr);
    }
  else if (proto == FIB_PROTOCOL_IP6)
    {
      ip_interface_address_t *interface_address;
      ip6_interface_address_matching_destination (&ip6_main, &nh->ip6, sw_if,
						  &interface_address);

      ip6_address_t *addr = NULL;
      if (interface_address != NULL)
	addr = (ip6_address_t *) ip_interface_address_get_address (
	  &ip6_main.lookup_main, interface_address);

      if (addr == NULL)
	addr = ip6_interface_first_address (&ip6_main, sw_if);

      if (addr != NULL)
	ip46_address_set_ip6 (local_address, addr);
    }

  return local_address;
}

static void
sync_hicn_fib_entry (hicn_dpo_ctx_t *fib_entry, hicn_face_id_t **pvec_faces)
{
  hicn_face_id_t *vec_faces = NULL;
  const dpo_id_t *dpo_loadbalance =
    fib_entry_contribute_ip_forwarding (fib_entry->fib_entry_index);
  const fib_entry_t *_fib_entry = fib_entry_get (fib_entry->fib_entry_index);
  const load_balance_t *lb0 = load_balance_get (dpo_loadbalance->dpoi_index);
  index_t hicn_fib_entry_index = hicn_strategy_dpo_ctx_get_index (fib_entry);

  dpo_id_t temp = DPO_INVALID;
  const dpo_id_t *former_dpo = &temp;
  int index = 0;

#define ADD_FACE(nh)                                                          \
  do                                                                          \
    {                                                                         \
      /* Careful, this adds a lock on the face if it exists */                \
      hicn_face_add (dpo, nh, sw_if, &face_id);                               \
      vec_validate (vec_faces, index);                                        \
      vec_faces[index] = face_id;                                             \
      (index)++;                                                              \
                                                                              \
      /* Face creation can realloc load_balance_t? Seem the fib_tracking does \
       * so. */                                                               \
      dpo_loadbalance =                                                       \
	fib_entry_contribute_ip_forwarding (fib_entry->fib_entry_index);      \
      lb0 = load_balance_get (dpo_loadbalance->dpoi_index);                   \
    }                                                                         \
  while (0)

  for (int j = 0; j < lb0->lb_n_buckets; j++)
    {
      const dpo_id_t *dpo = load_balance_get_bucket_i (lb0, j);

      int dpo_comparison = dpo_cmp (former_dpo, dpo);
      former_dpo = dpo;
      /*
       * Loadbalancing in ip replicate the dpo in multiple buckets
       * in order to honor the assigned weights.
       */
      if (dpo_comparison == 0)
	continue;

      u32 sw_if = ~0;
      ip46_address_t *nh = NULL;
      hicn_face_id_t face_id = HICN_FACE_NULL;

      if (dpo_is_adj (dpo))
	{
	  ip_adjacency_t *adj = adj_get (dpo->dpoi_index);
	  sw_if = adj->rewrite_header.sw_if_index;
	  nh = get_address (&(adj->sub_type.nbr.next_hop), sw_if,
			    fib_entry->proto);
	  ADD_FACE (nh);
	  HICN_DEBUG ("Added new HICN face: %d because of route prefix %U",
		      face_id, format_ip_prefix, &_fib_entry->fe_prefix);
	}
      else if (dpo->dpoi_type == dpo_type_udp_ip4 ||
	       dpo->dpoi_type == dpo_type_udp_ip6)
	{
	  dpo_proto_t proto =
	    dpo->dpoi_type == dpo_type_udp_ip4 ? DPO_PROTO_IP4 : DPO_PROTO_IP6;
	  ip46_address_t _nh = { 0 };
	  nh = &_nh;
	  switch (_fib_entry->fe_prefix.fp_proto)
	    {
	    case FIB_PROTOCOL_IP6:
	      ip46_address_set_ip6 (nh, &localhost6);
	      ADD_FACE (nh);
	      break;
	    case FIB_PROTOCOL_IP4:
	      ip46_address_set_ip4 (nh, &localhost4);
	      ADD_FACE (nh);
	      break;
	    default:
	      continue;
	    }
	  HICN_DEBUG ("Added new UDP face: %d because of route prefix %U",
		      face_id, format_ip_prefix, &_fib_entry->fe_prefix);
	  udp_tunnel_add_existing (dpo->dpoi_index, proto);
	}
      else if (dpo_is_pgserver (dpo))
	{
	  hicnpg_server_t *pg_server = hicnpg_server_get (dpo->dpoi_index);
	  ADD_FACE (&pg_server->hicn_locator);
	}
    }

  const hicn_dpo_vft_t *strategy_vft = hicn_dpo_get_vft (fib_entry->dpo_type);
  int i = 0;
  while (i < fib_entry->entry_count)
    {
      u32 idx_nh = vec_search (vec_faces, fib_entry->next_hops[i]);
      if (idx_nh == ~0)
	{
	  strategy_vft->hicn_dpo_del_nh (fib_entry->next_hops[i],
					 hicn_fib_entry_index);
	}
      else
	{
	  vec_del1 (vec_faces, idx_nh);

	  /* Remove the lock added by hicn_face_add */
	  hicn_face_unlock_with_id (fib_entry->next_hops[i]);
	  i++;
	}
    }

  hicn_face_id_t *face_id;
  vec_foreach (face_id, vec_faces)
    {
      strategy_vft->hicn_dpo_add_update_nh (*face_id, hicn_fib_entry_index);

      /* Remove the lock added by hicn_face_add */
      hicn_face_unlock_with_id (*face_id);
    }

  *pvec_faces = vec_faces;
}

static void
enable_disable_data_receiving (fib_protocol_t proto, u32 sw_if, u8 is_enable)
{
  if (proto == FIB_PROTOCOL_IP4 && sw_if != ~0)
    vnet_feature_enable_disable ("ip4-local", "hicn-data-input-ip4", sw_if,
				 is_enable, 0, 0);
  else if (proto == FIB_PROTOCOL_IP6 && sw_if != ~0)
    vnet_feature_enable_disable ("ip6-local", "hicn-data-input-ip6", sw_if,
				 is_enable, 0, 0);
}

walk_rc_t
enable_data_receiving_new_fib_entry (vnet_main_t *vnm, vnet_sw_interface_t *si,
				     void *ctx)
{
  fib_protocol_t *proto = (fib_protocol_t *) ctx;
  enable_disable_data_receiving (*proto, si->sw_if_index, 1);

  return (WALK_CONTINUE);
}

walk_rc_t
disable_data_receiving_rm_fib_entry (vnet_main_t *vnm, vnet_sw_interface_t *si,
				     void *ctx)
{
  fib_protocol_t *proto = (fib_protocol_t *) ctx;
  enable_disable_data_receiving (*proto, si->sw_if_index, 0);

  return (WALK_CONTINUE);
}

int
hicn_route_enable (fib_prefix_t *prefix, hicn_face_id_t **pvec_faces)
{

  int ret = HICN_ERROR_NONE;
  fib_node_index_t fib_entry_index;

  /* Check if the route already exist in the fib */
  /*
   * ASSUMPTION: we use table 0 which is the default table and it is
   * already existing and locked
   */
  u32 fib_index = fib_table_find (prefix->fp_proto, 0);

  fib_entry_index = fib_table_lookup_exact_match (fib_index, prefix);

  if (fib_entry_index == FIB_NODE_INDEX_INVALID)
    {
      fib_entry_index = fib_table_lookup (fib_index, prefix);

      fib_route_path_t *paths = fib_entry_encode (fib_entry_index);

      fib_table_entry_path_add2 (fib_index, prefix, FIB_SOURCE_CLI,
				 FIB_ENTRY_FLAG_NONE, paths);
    }

  /* Check if the prefix is already enabled */
  u32 fib_hicn_index = fib_table_find (prefix->fp_proto, HICN_FIB_TABLE);

  fib_node_index_t fib_hicn_entry_index =
    fib_table_lookup_exact_match (fib_hicn_index, prefix);

  if (fib_hicn_entry_index == FIB_NODE_INDEX_INVALID)
    {
      HICN_DEBUG (
	"No route found for %U. Creating DPO and tracking fib prefix.",
	format_ip_prefix, prefix);
      dpo_id_t dpo = DPO_INVALID;
      index_t dpo_idx;
      default_dpo.hicn_dpo_create (prefix->fp_proto, 0, NEXT_HOP_INVALID,
				   &dpo_idx);
      HICN_DEBUG ("Created new DPO_MW_CTX_T: %d.", dpo_idx);

      /* the value we got when we registered */
      /*
       * This should be taken from the name?!? the index of the
       * object
       */
      dpo_set (&dpo, default_dpo.hicn_dpo_get_type (),
	       (ip46_address_is_ip4 (&prefix->fp_addr) ? DPO_PROTO_IP4 :
							       DPO_PROTO_IP6),
	       dpo_idx);
      HICN_DEBUG (
	"dpo_set called with parameters: type=%d, proto=%s, index=%d",
	default_dpo.hicn_dpo_get_type (),
	ip46_address_is_ip4 (&prefix->fp_addr) ? "DPO_PROTO_IP4" :
						       "DPO_PROTO_IP6",
	dpo_idx);

      hicn_dpo_ctx_t *fib_entry = hicn_strategy_dpo_ctx_get (dpo_idx);

      fib_node_init (&fib_entry->fib_node, hicn_fib_node_type);
      fib_node_lock (&fib_entry->fib_node);

      fib_entry->fib_entry_index =
	fib_entry_track (fib_index, prefix, hicn_fib_node_type, dpo_idx,
			 &fib_entry->fib_sibling);

      /* Here is where we create the "via" like route */
      /*
       * For the moment we use the global one the prefix you want
       * to match Neale suggested -- FIB_SOURCE_HICN the client
       * that is adding them -- no easy explanation at this time…
       */
      CLIB_UNUSED (fib_node_index_t new_fib_node_index) =
	fib_table_entry_special_dpo_add (
	  fib_hicn_index, prefix, hicn_fib_src,
	  (FIB_ENTRY_FLAG_EXCLUSIVE | FIB_ENTRY_FLAG_LOOSE_URPF_EXEMPT), &dpo);

      HICN_DEBUG ("Calling sync_hicn_fib_entry");
      sync_hicn_fib_entry (fib_entry, pvec_faces);

      /* We added a route, therefore add one lock to the table */
      fib_table_lock (fib_index, prefix->fp_proto, hicn_fib_src);

      /* Enable the feature to punt data packet every time we enable a new hicn
       * route For each enable there must be a disable to defenitely disable
       * the feature
       *
       * We cannot enable only the interfaces on which we send out interest
       * because Data packet  might be coming on in different interfaces, as in
       * che case of mpls tunnels (packets are received from the physical nic,
       * not the mpls tunnel interface).
       */
      vnet_main_t *vnm = vnet_get_main ();
      vnet_sw_interface_walk (vnm, enable_data_receiving_new_fib_entry,
			      &(prefix->fp_proto));

      dpo_unlock (&dpo);
    }
  else
    {
      HICN_DEBUG ("Found a route for %U. Updating DPO.", format_ip_prefix,
		  &prefix);
      const dpo_id_t *load_balance_dpo_id;
      const dpo_id_t *strategy_dpo_id;

      /* Route already existing. We need to update the dpo. */
      load_balance_dpo_id =
	fib_entry_contribute_ip_forwarding (fib_hicn_entry_index);

      /* The dpo is not a load balance dpo as expected */
      if (load_balance_dpo_id->dpoi_type != DPO_LOAD_BALANCE)
	{
	  ret = HICN_ERROR_ROUTE_NO_LD;
	  HICN_ERROR ("DPO is not a load balance.");
	  goto done;
	}
      else
	{
	  load_balance_t *lb =
	    load_balance_get (load_balance_dpo_id->dpoi_index);

	  strategy_dpo_id = load_balance_get_bucket_i (lb, 0);

	  if (!dpo_is_hicn (strategy_dpo_id))
	    {
	      ret = HICN_ERROR_ROUTE_DPO_NO_HICN;
	      HICN_ERROR ("DPO is not hicn.");
	      goto done;
	    }

	  if (lb->lb_n_buckets > 1)
	    {
	      ret = HICN_ERROR_ROUTE_MLT_LD;
	      HICN_ERROR ("Too many load balance buckets.");
	      goto done;
	    }

	  hicn_dpo_ctx_t *hicn_fib_entry =
	    hicn_strategy_dpo_ctx_get (strategy_dpo_id->dpoi_index);

	  HICN_DEBUG ("Calling sync_hicn_fib_entry");
	  sync_hicn_fib_entry (hicn_fib_entry, pvec_faces);
	}
    }

done:
  return ret;
}

int
hicn_route_disable (fib_prefix_t *prefix)
{

  int ret = HICN_ERROR_NONE;

  /* Check if the prefix is already enabled */
  u32 fib_hicn_index = fib_table_find (prefix->fp_proto, HICN_FIB_TABLE);

  fib_node_index_t fib_hicn_entry_index =
    fib_table_lookup_exact_match (fib_hicn_index, prefix);

  if (fib_hicn_entry_index == FIB_NODE_INDEX_INVALID)
    {
      HICN_ERROR ("Route %U not found", format_ip_prefix, prefix);
      return HICN_ERROR_ROUTE_NOT_FOUND;
    }
  else
    {
      const dpo_id_t *load_balance_dpo_id;
      const dpo_id_t *strategy_dpo_id;
      hicn_dpo_ctx_t *hicn_fib_entry;

      /* Route already existing. We need to update the dpo. */
      load_balance_dpo_id =
	fib_entry_contribute_ip_forwarding (fib_hicn_entry_index);

      /* The dpo is not a load balance dpo as expected */
      if (load_balance_dpo_id->dpoi_type != DPO_LOAD_BALANCE)
	{
	  HICN_ERROR ("DPO for route %U is not a load balance.",
		      format_ip_prefix, prefix);
	  ret = HICN_ERROR_ROUTE_NO_LD;
	  goto done;
	}
      else
	{
	  load_balance_t *lb =
	    load_balance_get (load_balance_dpo_id->dpoi_index);

	  strategy_dpo_id = load_balance_get_bucket_i (lb, 0);

	  if (!dpo_is_hicn (strategy_dpo_id))
	    {
	      HICN_ERROR ("ERROR: DPO for route %U is not a hicn.",
			  format_ip_prefix, prefix);
	      ret = HICN_ERROR_ROUTE_DPO_NO_HICN;
	      goto done;
	    }

	  if (lb->lb_n_buckets > 1)
	    {
	      HICN_ERROR ("DPO for route %U contains multiple next hops.",
			  format_ip_prefix, prefix);
	      ret = HICN_ERROR_ROUTE_MLT_LD;
	      goto done;
	    }

	  hicn_fib_entry =
	    hicn_strategy_dpo_ctx_get (strategy_dpo_id->dpoi_index);

	  HICN_DEBUG ("Found from hicn_strategy_dpo_ctx_get with index %d: %p",
		      strategy_dpo_id->dpoi_index, hicn_fib_entry);

	  if (PREDICT_FALSE (!hicn_fib_entry))
	    {
	      HICN_ERROR (
		"hicn_strategy_dpo_ctx_get for index %d returned NULL",
		strategy_dpo_id->dpoi_index);
	      ret = HICN_ERROR_ROUTE_DPO_NO_HICN;
	      goto done;
	    }

	  for (int i = 0; i < hicn_fib_entry->entry_count; i++)
	    {
	      hicn_strategy_dpo_ctx_del_nh (hicn_fib_entry->next_hops[i],
					    hicn_fib_entry);
	    }

	  hicn_mapme_tfib_clear ((hicn_mapme_tfib_t *) hicn_fib_entry);
	}

      HICN_DEBUG (
	"Calling fib_entry_untrack and fib_table_entry_special_remove "
	"for route %U.",
	format_ip_prefix, prefix);

      fib_entry_untrack (hicn_fib_entry->fib_entry_index,
			 hicn_fib_entry->fib_sibling);

      fib_table_entry_special_remove (fib_hicn_index, prefix, hicn_fib_src);
      fib_node_unlock (&hicn_fib_entry->fib_node);

      /* Disable the feature to punt data packet every time we enable a new
       * hicn route */
      vnet_main_t *vnm = vnet_get_main ();
      vnet_sw_interface_walk (vnm, disable_data_receiving_rm_fib_entry,
			      &(prefix->fp_proto));
    }

done:
  return ret;
}

static fib_node_t *
hicn_ctx_node_get (fib_node_index_t index)
{
  hicn_dpo_ctx_t *hicn_ctx;

  hicn_ctx = hicn_strategy_dpo_ctx_get (index);

  return (&hicn_ctx->fib_node);
}

static void
hicn_fib_last_lock_gone (fib_node_t *node)
{
}

static hicn_dpo_ctx_t *
hicn_ctx_from_fib_node (fib_node_t *node)
{
  return ((hicn_dpo_ctx_t *) (((char *) node) -
			      STRUCT_OFFSET_OF (hicn_dpo_ctx_t, fib_node)));
}

static fib_node_back_walk_rc_t
hicn_fib_back_walk_notify (fib_node_t *node, fib_node_back_walk_ctx_t *ctx)
{

  hicn_dpo_ctx_t *fib_entry = hicn_ctx_from_fib_node (node);

  hicn_face_id_t *vec_faces = NULL;
  HICN_DEBUG ("Calling sync_hicn_fib_entry from hicn_fib_back_walk_notify");
  sync_hicn_fib_entry (fib_entry, &vec_faces);
  if (vec_faces != NULL)
    vec_free (vec_faces);

  return (FIB_NODE_BACK_WALK_CONTINUE);
}

static void
hicn_fib_show_memory (void)
{
}

static const fib_node_vft_t hicn_fib_vft = {
  .fnv_get = hicn_ctx_node_get,
  .fnv_last_lock = hicn_fib_last_lock_gone,
  .fnv_back_walk = hicn_fib_back_walk_notify,
  .fnv_mem_show = hicn_fib_show_memory,
};

fib_table_walk_rc_t
enable_data_on_existing_hicn (fib_node_index_t fei, void *ctx)
{
  u32 sw_if = *(u32 *) ctx;
  const dpo_id_t *load_balance_dpo_id;
  const dpo_id_t *strategy_dpo_id;

  /* Route already existing. We need to update the dpo. */
  load_balance_dpo_id = fib_entry_contribute_ip_forwarding (fei);

  /* The dpo is not a load balance dpo as expected */
  if (load_balance_dpo_id->dpoi_type != DPO_LOAD_BALANCE)
    {
      goto done;
    }
  else
    {
      load_balance_t *lb = load_balance_get (load_balance_dpo_id->dpoi_index);

      strategy_dpo_id = load_balance_get_bucket_i (lb, 0);

      if (!dpo_is_hicn (strategy_dpo_id))
	{
	  goto done;
	}

      enable_disable_data_receiving (
	(fib_protocol_t) strategy_dpo_id->dpoi_proto, sw_if, 1);
    }

done:
  return (FIB_TABLE_WALK_CONTINUE);
}

static clib_error_t *
set_table_interface_add_del (vnet_main_t *vnm, u32 sw_if_index, u32 is_add)
{

  if (!is_add)
    return NULL;

  int rv = ip_table_bind (FIB_PROTOCOL_IP4, sw_if_index, HICN_FIB_TABLE);

  if (!rv)
    {
      rv = ip_table_bind (FIB_PROTOCOL_IP6, sw_if_index, HICN_FIB_TABLE);

      if (rv)
	{
	  /* An error occurred. Bind the interface back to the default fib */
	  ip_table_bind (FIB_PROTOCOL_IP4, sw_if_index, 0);
	}
    }

  u32 fib_index = fib_table_find (FIB_PROTOCOL_IP4, HICN_FIB_TABLE);
  if (fib_index != ~0)
    {
      /*
       * Walk the ip4 and ip6 fib tables to discover existing hicn fib entries.
       * For each of them we need to enable the feature to punt data packets.
       */
      fib_table_walk (fib_index, FIB_PROTOCOL_IP4,
		      enable_data_on_existing_hicn, &sw_if_index);
    }

  fib_index = fib_table_find (FIB_PROTOCOL_IP6, HICN_FIB_TABLE);
  if (fib_index != ~0)
    {
      fib_table_walk (fib_index, FIB_PROTOCOL_IP6,
		      enable_data_on_existing_hicn, &sw_if_index);
    }

  return rv ? clib_error_return (0, "unable to add hicn table to interface") :
		    0;
}

VNET_SW_INTERFACE_ADD_DEL_FUNCTION_PRIO (set_table_interface_add_del,
					 VNET_ITF_FUNC_PRIORITY_HIGH);

void
hicn_route_init ()
{
  vnet_main_t *vnm = vnet_get_main ();
  vlib_main_t *vm = vlib_get_main ();
  hicn_fib_src =
    fib_source_allocate ("hicn", FIB_SOURCE_HICN, FIB_SOURCE_BH_API);

  hicn_fib_node_type =
    fib_node_register_new_type ("hicn_route_fib_node", &hicn_fib_vft);

  ip_table_create (FIB_PROTOCOL_IP4, HICN_FIB_TABLE, 1, (const u8 *) "hicn4");
  ip_table_create (FIB_PROTOCOL_IP6, HICN_FIB_TABLE, 1, (const u8 *) "hicn6");

  u32 sw_if_index;
  u8 mac_address[6];
  u8 is_specified = 0;
  u32 user_instance = 0;

  vnet_create_loopback_interface (&sw_if_index, mac_address, is_specified,
				  user_instance);

  localhost4.as_u8[0] = 127;
  localhost4.as_u8[3] = 1;
  u32 length4 = 32, length6 = 128, is_del = 0, flags = 0;

  localhost6.as_u8[15] = 1;

  ip4_add_del_interface_address (vm, sw_if_index, &localhost4, length4,
				 is_del);
  ip6_add_del_interface_address (vm, sw_if_index, &localhost6, length6,
				 is_del);

  flags |= VNET_SW_INTERFACE_FLAG_ADMIN_UP;
  vnet_sw_interface_set_flags (vnm, sw_if_index, flags);
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables: eval: (c-set-style "gnu") End:
 */