/*
 * 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.
 */
/*
 *------------------------------------------------------------------
 * ad.c - SRv6 Dynamic Proxy (AD) function
 *------------------------------------------------------------------
 */

#include <vnet/vnet.h>
#include <vnet/adj/adj.h>
#include <vnet/plugin/plugin.h>
#include <vpp/app/version.h>
#include <srv6-ad/ad.h>

#define SID_CREATE_IFACE_FEATURE_ERROR  -1
#define SID_CREATE_INVALID_IFACE_TYPE   -3
#define SID_CREATE_INVALID_IFACE_INDEX  -4
#define SID_CREATE_INVALID_ADJ_INDEX    -5

unsigned char function_name[] = "SRv6-AD-plugin";
unsigned char keyword_str[] = "End.AD";
unsigned char def_str[] =
  "Endpoint with dynamic proxy to SR-unaware appliance";
unsigned char params_str[] = "nh <next-hop> oif <iface-out> iif <iface-in>";

srv6_ad_main_t srv6_ad_main;

/*****************************************/
/* SRv6 LocalSID instantiation and removal functions */
static int
srv6_ad_localsid_creation_fn (ip6_sr_localsid_t * localsid)
{
  ip6_sr_main_t *srm = &sr_main;
  srv6_ad_main_t *sm = &srv6_ad_main;
  srv6_ad_localsid_t *ls_mem = localsid->plugin_mem;
  u32 localsid_index = localsid - srm->localsids;

  /* Step 1: Prepare xconnect adjacency for sending packets to the VNF */

  /* Retrieve the adjacency corresponding to the (OIF, next_hop) */
  adj_index_t nh_adj_index = ADJ_INDEX_INVALID;
  if (ls_mem->inner_type != AD_TYPE_L2)
    {
      if (ls_mem->inner_type == AD_TYPE_IP4)
	nh_adj_index = adj_nbr_add_or_lock (FIB_PROTOCOL_IP4,
					    VNET_LINK_IP4, &ls_mem->nh_addr,
					    ls_mem->sw_if_index_out);
      else if (ls_mem->inner_type == AD_TYPE_IP6)
	nh_adj_index = adj_nbr_add_or_lock (FIB_PROTOCOL_IP6,
					    VNET_LINK_IP6, &ls_mem->nh_addr,
					    ls_mem->sw_if_index_out);
      if (nh_adj_index == ADJ_INDEX_INVALID)
	{
	  clib_mem_free (ls_mem);
	  return SID_CREATE_INVALID_ADJ_INDEX;
	}
    }

  ls_mem->nh_adj = nh_adj_index;


  /* Step 2: Prepare inbound policy for packets returning from the VNF */

  /* Sanitise the SW_IF_INDEX */
  if (pool_is_free_index (sm->vnet_main->interface_main.sw_interfaces,
			  ls_mem->sw_if_index_in))
    {
      adj_unlock (ls_mem->nh_adj);
      clib_mem_free (ls_mem);
      return SID_CREATE_INVALID_IFACE_INDEX;
    }

  vnet_sw_interface_t *sw = vnet_get_sw_interface (sm->vnet_main,
						   ls_mem->sw_if_index_in);
  if (sw->type != VNET_SW_INTERFACE_TYPE_HARDWARE)
    {
      adj_unlock (ls_mem->nh_adj);
      clib_mem_free (ls_mem);
      return SID_CREATE_INVALID_IFACE_TYPE;
    }

  if (ls_mem->inner_type == AD_TYPE_L2)
    {
      /* Enable End.AD2 rewrite node for this interface */
      int ret =
	vnet_feature_enable_disable ("device-input", "srv6-ad2-rewrite",
				     ls_mem->sw_if_index_in, 1, 0, 0);
      if (ret != 0)
	{
	  clib_mem_free (ls_mem);
	  return SID_CREATE_IFACE_FEATURE_ERROR;
	}

      /* Set interface in promiscuous mode */
      vnet_main_t *vnm = vnet_get_main ();
      ethernet_set_flags (vnm, ls_mem->sw_if_index_in,
			  ETHERNET_INTERFACE_FLAG_ACCEPT_ALL);

      /* Associate local SID index to this interface (resize vector if needed) */
      if (ls_mem->sw_if_index_in >= vec_len (sm->sw_iface_localsid2))
	{
	  vec_resize (sm->sw_iface_localsid2,
		      (pool_len (sm->vnet_main->interface_main.sw_interfaces)
		       - vec_len (sm->sw_iface_localsid2)));
	}
      sm->sw_iface_localsid2[ls_mem->sw_if_index_in] = localsid_index;
    }
  else if (ls_mem->inner_type == AD_TYPE_IP4)
    {
      /* Enable End.AD4 rewrite node for this interface */
      int ret =
	vnet_feature_enable_disable ("ip4-unicast", "srv6-ad4-rewrite",
				     ls_mem->sw_if_index_in, 1, 0, 0);
      if (ret != 0)
	{
	  adj_unlock (ls_mem->nh_adj);
	  clib_mem_free (ls_mem);
	  return SID_CREATE_IFACE_FEATURE_ERROR;
	}

      /* Associate local SID index to this interface (resize vector if needed) */
      if (ls_mem->sw_if_index_in >= vec_len (sm->sw_iface_localsid4))
	{
	  vec_resize (sm->sw_iface_localsid4,
		      (pool_len (sm->vnet_main->interface_main.sw_interfaces)
		       - vec_len (sm->sw_iface_localsid4)));
	}
      sm->sw_iface_localsid4[ls_mem->sw_if_index_in] = localsid_index;
    }
  else if (ls_mem->inner_type == AD_TYPE_IP6)
    {
      /* Enable End.AD6 rewrite node for this interface */
      int ret =
	vnet_feature_enable_disable ("ip6-unicast", "srv6-ad6-rewrite",
				     ls_mem->sw_if_index_in, 1, 0, 0);
      if (ret != 0)
	{
	  adj_unlock (ls_mem->nh_adj);
	  clib_mem_free (ls_mem);
	  return SID_CREATE_IFACE_FEATURE_ERROR;
	}

      /* Associate local SID index to this interface (resize vector if needed) */
      if (ls_mem->sw_if_index_in >= vec_len (sm->sw_iface_localsid6))
	{
	  vec_resize (sm->sw_iface_localsid6,
		      (pool_len (sm->vnet_main->interface_main.sw_interfaces)
		       - vec_len (sm->sw_iface_localsid6)));
	}
      sm->sw_iface_localsid6[ls_mem->sw_if_index_in] = localsid_index;
    }

  ls_mem->rw_len = 0;

  /* Step 3: Initialize rewrite counters */
  srv6_ad_localsid_t **ls_p;
  pool_get (sm->sids, ls_p);
  *ls_p = ls_mem;
  ls_mem->index = ls_p - sm->sids;

  vlib_validate_combined_counter (&(sm->valid_counters), ls_mem->index);
  vlib_validate_combined_counter (&(sm->invalid_counters), ls_mem->index);

  vlib_zero_combined_counter (&(sm->valid_counters), ls_mem->index);
  vlib_zero_combined_counter (&(sm->invalid_counters), ls_mem->index);

  return 0;
}

static int
srv6_ad_loc<style>
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