/*
 * decap.c - decapsulate VXLAN GPE
 *
 * Copyright (c) 2013 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.
 */
/**
 *  @file
 *  @brief Functions for decapsulating VXLAN GPE tunnels
 *
*/

#include <vlib/vlib.h>
#include <vnet/pg/pg.h>
#include <vnet/vxlan-gpe/vxlan_gpe.h>

vlib_node_registration_t vxlan_gpe_input_node;

/**
 * @brief Struct for VXLAN GPE decap packet tracing
 *
 */
typedef struct {
  u32 next_index;
  u32 tunnel_index;
  u32 error;
} vxlan_gpe_rx_trace_t;

/**
 * @brief Tracing function for VXLAN GPE packet decapsulation
 *
 * @param *s
 * @param *args
 *
 * @return *s
 *
 */
static u8 * format_vxlan_gpe_rx_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 *);
  vxlan_gpe_rx_trace_t * t = va_arg (*args, vxlan_gpe_rx_trace_t *);

  if (t->tunnel_index != ~0)
  {
    s = format (s, "VXLAN-GPE: tunnel %d next %d error %d", t->tunnel_index,
        t->next_index, t->error);
  }
  else
  {
    s = format (s, "VXLAN-GPE: no tunnel next %d error %d\n", t->next_index,
        t->error);
  }
  return s;
}

/**
 * @brief Tracing function for VXLAN GPE packet decapsulation including length
 *
 * @param *s
 * @param *args
 *
 * @return *s
 *
 */
static u8 * format_vxlan_gpe_with_length (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 *);


  return s;
}

/**
 * @brief Common processing for IPv4 and IPv6 VXLAN GPE decap dispatch functions
 *
 * It is worth noting that other than trivial UDP forwarding (transit), VXLAN GPE
 * tunnels are "terminate local". This means that there is no "TX" interface for this
 * decap case, so that field in the buffer_metadata can be "used for something else".
 * The something else in this case is, for the IPv4/IPv6 inner-packet type case, the
 * FIB index used to look up the inner-packet's adjacency.
 *
 *      vnet_buffer(b0)->sw_if_index[VLIB_TX] = t0->decap_fib_index;
 *
 * @param *vm
 * @param *node
 * @param *from_frame
 * @param is_ip4
 *
 * @return from_frame->n_vectors
 *
 */
always_inline uword
vxlan_gpe_input (vlib_main_t * vm,
                     vlib_node_runtime_t * node,
                     vlib_frame_t * from_frame,
					 u8 is_ip4)
{
  u32 n_left_from, next_index, *from, *to_next;
  vxlan_gpe_main_t * nngm = &vxlan_gpe_main;
  vnet_main_t * vnm = nngm->vnet_main;
  vnet_interface_main_t * im = &vnm->interface_main;
  u32 last_tunnel_index = ~0;
  vxlan4_gpe_tunnel_key_t last_key4;
  vxlan6_gpe_tunnel_key_t last_key6;
  u32 pkts_decapsulated = 0;
  u32 thread_index = vlib_get_thread_index ();
  u32 stats_sw_if_index, stats_n_packets, stats_n_bytes;

  if (is_ip4)
      memset (&last_key4, 0xff, sizeof(last_key4));
  else
      memset (&last_key6, 0xff, sizeof(last_key6));

  from = vlib_frame_vector_args (from_frame);
  n_left_from = from_frame->n_vectors;

  next_index = node->cached_next_index;
  stats_sw_if_index = node->runtime_data[0];
  stats_n_packets = stats_n_bytes = 0;

  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 >= 4 && n_left_to_next >= 2)
    {
      u32 bi0, bi1;
      vlib_buffer_t * b0, *b1;
      u32 next0, next1;
      ip4_vxlan_gpe_header_t * iuvn4_0, *iuvn4_1;
      ip6_vxlan_gpe_header_t * iuvn6_0, *iuvn6_1;
      uword * p0, *p1;
      u32 tunnel_index0, tunnel_index1;
      vxlan_gpe_tunnel_t * t0, *t1;
      vxlan4_gpe_tunnel_key_t key4_0, key4_1;
      vxlan6_gpe_tunnel_key_t key6_0, key6_1;
      u32 error0, error1;
      u32 sw_if_index0, sw_if_index1, len0, len1;

      /* Prefetch next iteration. */
      {
        vlib_buffer_t * p2, *p3;

        p2 = vlib_get_buffer (vm, from[2]);
        p3 = vlib_get_buffer (vm, from[3]);

        vlib_prefetch_buffer_header(p2, LOAD);
        vlib_prefetch_buffer_header(p3, LOAD);

        CLIB_PREFETCH(p2->data, 2*CLIB_CACHE_LINE_BYTES, LOAD);
        CLIB_PREFETCH(p3->data, 2*CLIB_CACHE_LINE_BYTES, LOAD);
      }

      bi0 = from[0];
      bi1 = from[1];
      to_next[0] = bi0;
      to_next[1] = bi1;
      from += 2;
      to_next += 2;
      n_left_to_next -= 2;
      n_left_from -= 2;

      b0 = vlib_get_buffer (vm, bi0);
      b1 = vlib_get_buffer (vm, bi1);

      if (is_ip4)
      {
        /* udp leaves current_data pointing at the vxlan-gpe header */
        vlib_buffer_advance (b0, -(word) (sizeof(udp_header_t) + sizeof(ip4_header_t)));
        vlib_buffer_advance (b1, -(word) (sizeof(udp_header_t) + sizeof(ip4_header_t)));

        iuvn4_0 = vlib_buffer_get_current (b0);
        iuvn4_1 = vlib_buffer_get_current (b1);

        /* pop (ip, udp, vxlan) */
        vlib_buffer_advance (b0, sizeof(*iuvn4_0));
        vlib_buffer_advance (b1, sizeof(*iuvn4_1));
      }
      else
      {
        /* udp leaves current_data pointing at the vxlan-gpe header */
        vlib_buffer_advance (b0, -(word) (sizeof(udp_header_t) + sizeof(ip6_header_t)));
        vlib_buffer_advance (b1, -(word) (sizeof(udp_header_t) + sizeof(ip6_header_t)));

        iuvn6_0 = vlib_buffer_get_current (b0);
        iuvn6_1 = vlib_buffer_get_current (b1);

        /* pop (ip, udp, vxlan) */
        vlib_buffer_advance (b0, sizeof(*iuvn6_0));
        vlib_buffer_advance (b1, sizeof(*iuvn6_1));
      }

      tunnel_index0 = ~0;
      tunnel_index1 = ~0;
      error0 = 0;
      error1 = 0;

      if (is_ip4)
      {
        next0 =
            (iuvn4_0->vxlan.protocol < VXLAN_GPE_PROTOCOL_MAX)?
            nngm->decap_next_node_list[iuvn4_0->vxlan.protocol]: \
            VXLAN_GPE_INPUT_NEXT_DROP;
        next1 =
            (iuvn4_1->vxlan.protocol < VXLAN_GPE_PROTOCOL_MAX)?
            nngm->decap_next_node_list[iuvn4_1->vxlan.protocol]: \
            VXLAN_GPE_INPUT_NEXT_DROP;

        key4_0.local = iuvn4_0->ip4.dst_address.as_u32;
        key4_1.local = iuvn4_1->ip4.dst_address.as_u32;

        key4_0.remote = iuvn4_0->ip4.src_address.as_u32;
        key4_1.remote = iuvn4_1->ip4.src_address.as_u32;

        key4_0.vni = iuvn4_0->vxlan.vni_res;
        key4_1.vni = iuvn4_1->vxlan.vni_res;

        key4_0.pad = 0;
        key4_1.pad = 0;
      }
      else /* is_ip6 */
      {
        next0 = (iuvn6_0->vxlan.protocol < node->n_next_nodes) ?
                iuvn6_0->vxlan.protocol : VXLAN_GPE_INPUT_NEXT_DROP;
        next1 = (iuvn6_1->vxlan.protocol < node->n_next_nodes) ?
                iuvn6_1->vxlan.protocol : VXLAN_GPE_INPUT_NEXT_DROP;

        key6_0.local.as_u64[0] = iuvn6_0->ip6.dst_address.as_u64[0];
        key6_0.local.as_u64[1] = iuvn6_0->ip6.dst_address.as_u64[1];
        key6_1.local.as_u64[0] = iuvn6_1->ip6.dst_address.as_u64[0];
        key6_1.local.as_u64[1] = iuvn6_1->ip6.dst_address.as_u64[1];

        key6_0.remote.as_u64[0] = iuvn6_0->ip6.src_address.as_u64[0];
        key6_0.remote.as_u64[1] = iuvn6_0->ip6.src_address.as_u64[1];
        key6_1.remote.as_u64[0] = iuvn6_1->ip6.src_address.as_u64[0];
        key6_1.remote.as_u64[1] = iuvn6_1->ip6.src_address.as_u64[1];

        key6_0.vni = iuvn6_0->vxlan.vni_res;
        key6_1.vni = iuvn6_1->vxlan.vni_res;
      }

      /* Processing packet 0*/
      if (is_ip4)
      {
        /* Processing for key4_0 */
        if (PREDICT_FALSE((key4_0.as_u64[0] != last_key4.as_u64[0])
                || (key4_0.as_u64[1] != last_key4.as_u64[1])))
        {
          p0 = hash_get_mem(nngm->vxlan4_gpe_tunnel_by_key, &key4_0);

          if (p0 == 0)
          {
            error0 = VXLAN_GPE_ERROR_NO_SUCH_TUNNEL;
            goto trace0;
          }

          last_key4.as_u64[0] = key4_0.as_u64[0];
          last_key4.as_u64[1] = key4_0.as_u64[1];
          tunnel_index0 = last_tunnel_index = p0[0];
        }
        else
          tunnel_index0 = last_tunnel_index;
      }
      else /* is_ip6 */
      {
        next0 =
            (iuvn6_0->vxlan.protocol < VXLAN_GPE_PROTOCOL_MAX)?
            nngm->decap_next_node_list[iuvn6_0->vxlan.protocol]: \
            VXLAN_GPE_INPUT_NEXT_DROP;
        next1 =
            (iuvn6_1->vxlan.protocol < VXLAN_GPE_PROTOCOL_MAX)?
            nngm->decap_next_node_list[iuvn6_1->vxlan.protocol]: \
            VXLAN_GPE_INPUT_NEXT_DROP;

        key6_0.local.as_u64[0] = iuvn6_0->ip6.dst_address.as_u64[0];
        key6_0.local.as_u64[1] = iuvn6_0->ip6.dst_address.as_u64[1];
        key6_1.local.as_u64[0] = iuvn6_1->ip6.dst_address.as_u64[0];
        key6_1.local.as_u64[1] = iuvn6_1->ip6.dst_address.as_u64[1];

        key6_0.remote.as_u64[0] = iuvn6_0->ip6.src_address.as_u64[0];
        key6_0.remote.as_u64[1] = iuvn6_0->ip6.src_address.as_u64[1];
        key6_1.remote.as_u64[0] = iuvn6_1->ip6.src_address.as_u64[0];
        key6_1.remote.as_u64[1] = iuvn6_1->ip6.src_address.as_u64[1];

        key6_0.vni = iuvn6_0->vxlan.vni_res;
        key6_1.vni = iuvn6_1->vxlan.vni_res;

        /* Processing for key6_0 */
        if (PREDICT_FALSE(memcmp (&key6_0, &last_key6, sizeof(last_key6)) != 0))
        {
          p0 = hash_get_mem(nngm->vxlan6_gpe_tunnel_by_key, &key6_0);

          if (p0 == 0)
          {
            error0 = VXLAN_GPE_ERROR_NO_SUCH_TUNNEL;
            goto trace0;
          }

          memcpy (&last_key6, &key6_0, sizeof(key6_0));
          tunnel_index0 = last_tunnel_index = p0[0];
        }
        else
          tunnel_index0 = last_tunnel_index;
      }

      t0 = pool_elt_at_index(nngm->tunnels, tunnel_index0);


      sw_if_index0 = t0->sw_if_index;
      len0 = vlib_buffer_length_in_chain (vm, b0);

      /* Required to make the l2 tag push / pop code work on l2 subifs */
      vnet_update_l2_len (b0);

      /**
       * ip[46] lookup in the configured FIB
       */
      vnet_buffer(b0)->sw_if_index[VLIB_TX] = t0->decap_fib_index;

      pkts_decapsulated++;
      stats_n_packets += 1;
      stats_n_bytes += len0;

      if (PREDICT_FALSE(sw_if_index0 != stats_sw_if_index))
      {
        stats_n_packets -= 1;
        stats_n_bytes -= len0;
        if (stats_n_packets)
          vlib_increment_combined_counter (
              im->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX,
              thread_index, stats_sw_if_index, stats_n_packets, stats_n_bytes);
        stats_n_packets = 1;
        stats_n_bytes = len0;
        stats_sw_if_index = sw_if_index0;
      }

      trace0: b0->error = error0 ? node->errors[error0] : 0;

      if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
      {
        vxlan_gpe_rx_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof(*tr));
        tr->next_index = next0;
        tr->error = error0;
        tr->tunnel_index = tunnel_index0;
      }

      /* Process packet 1 */
      if (is_ip4)
      {
        /* Processing for key4_1 */
        if (PREDICT_FALSE(
            (key4_1.as_u64[0] != last_key4.as_u64[0])
                || (key4_1.as_u64[1] != last_key4.as_u64[1])))
        {
          p1 = hash_get_mem(nngm->vxlan4_gpe_tunnel_by_key, &key4_1);

          if (p1 == 0)
          {
            error1 = VXLAN_GPE_ERROR_NO_SUCH_TUNNEL;
            goto trace1;
          }

          last_key4.as_u64[0] = key4_1.as_u64[0];
          last_key4.as_u64[1] = key4_1.as_u64[1];
          tunnel_index1 = last_tunnel_index = p1[0];
        }
        else
          tunnel_index1 = last_tunnel_index;
      }
      else /* is_ip6 */
      {
        /* Processing for key6_1 */
        if (PREDICT_FALSE(memcmp (&key6_1, &last_key6, sizeof(last_key6)) != 0))
        {
          p1 = hash_get_mem(nngm->vxlan6_gpe_tunnel_by_key, &key6_1);

          if (p1 == 0)
          {
            error1 = VXLAN_GPE_ERROR_NO_SUCH_TUNNEL;
            goto trace1;
          }

          memcpy (&last_key6, &key6_1, sizeof(key6_1));
          tunnel_index1 = last_tunnel_index = p1[0];
        }
        else
          tunnel_index1 = last_tunnel_index;
      }

      t1 = pool_elt_at_index(nngm->tunnels, tunnel_index1);

      sw_if_index1 = t1->sw_if_index;
      len1 = vlib_buffer_length_in_chain (vm, b1);

      /* Required to make the l2 tag push / pop code work on l2 subifs */
      vnet_update_l2_len (b1);

      /*
       * ip[46] lookup in the configured FIB
       */
      vnet_buffer(b1)->sw_if_index[VLIB_TX] = t1->decap_fib_index;

      pkts_decapsulated++;
      stats_n_packets += 1;
      stats_n_bytes += len1;

      /* Batch stats increment on the same vxlan tunnel so counter
       is not incremented per packet */
      if (PREDICT_FALSE(sw_if_index1 != stats_sw_if_index))
      {
        stats_n_packets -= 1;
        stats_n_bytes -= len1;
        if (stats_n_packets)
          vlib_increment_combined_counter (
              im->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX,
              thread_index, stats_sw_if_index, stats_n_packets, stats_n_bytes);
        stats_n_packets = 1;
        stats_n_bytes = len1;
        stats_sw_if_index = sw_if_index1;
      }
      vnet_buffer(b1)->sw_if_index[VLIB_TX] = t1->decap_fib_index;

      trace1: b1->error = error1 ? node->errors[error1] : 0;

      if (PREDICT_FALSE(b1->flags & VLIB_BUFFER_IS_TRACED))
      {
        vxlan_gpe_rx_trace_t *tr = vlib_add_trace (vm, node, b1, sizeof(*tr));
        tr->next_index = next1;
        tr->error = error1;
        tr->tunnel_index = tunnel_index1;
      }

      vlib_validate_buffer_enqueue_x2(vm, node, next_index, to_next,
                                      n_left_to_next, bi0, bi1, next0, next1);
    }

    while (n_left_from > 0 && n_left_to_next > 0)
    {
      u32 bi0;
      vlib_buffer_t * b0;
      u32 next0;
      ip4_vxlan_gpe_header_t * iuvn4_0;
      ip6_vxlan_gpe_header_t * iuvn6_0;
      uword * p0;
      u32 tunnel_index0;
      vxlan_gpe_tunnel_t * t0;
      vxlan4_gpe_tunnel_key_t key4_0;
      vxlan6_gpe_tunnel_key_t key6_0;
      u32 error0;
      u32 sw_if_index0, len0;

      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);

      if (is_ip4)
      {
        /* udp leaves current_data pointing at the vxlan-gpe header */
        vlib_buffer_advance (
            b0, -(word) (sizeof(udp_header_t) + sizeof(ip4_header_t)));

        iuvn4_0 = vlib_buffer_get_current (b0);

        /* pop (ip, udp, vxlan) */
        vlib_buffer_advance (b0, sizeof(*iuvn4_0));
      }
      else
      {
        /* udp leaves current_data pointing at the vxlan-gpe header */
        vlib_buffer_advance (
            b0, -(word) (sizeof(udp_header_t) + sizeof(ip6_header_t)));

        iuvn6_0 = vlib_buffer_get_current (b0);

        /* pop (ip, udp, vxlan) */
        vlib_buffer_advance (b0, sizeof(*iuvn6_0));
      }

      tunnel_index0 = ~0;
      error0 = 0;

      if (is_ip4)
      {
        next0 =
            (iuvn4_0->vxlan.protocol < VXLAN_GPE_PROTOCOL_MAX)?
            nngm->decap_next_node_list[iuvn4_0->vxlan.protocol]: \
            VXLAN_GPE_INPUT_NEXT_DROP;

        key4_0.local = iuvn4_0->ip4.dst_address.as_u32;
        key4_0.remote = iuvn4_0->ip4.src_address.as_u32;
        key4_0.vni = iuvn4_0->vxlan.vni_res;
        key4_0.pad = 0;

        /* Processing for key4_0 */
        if (PREDICT_FALSE(
            (key4_0.as_u64[0] != last_key4.as_u64[0])
                || (key4_0.as_u64[1] != last_key4.as_u64[1])))
        {
          p0 = hash_get_mem(nngm->vxlan4_gpe_tunnel_by_key, &key4_0);

          if (p0 == 0)
          {
            error0 = VXLAN_GPE_ERROR_NO_SUCH_TUNNEL;
            goto trace00;
          }

          last_key4.as_u64[0] = key4_0.as_u64[0];
          last_key4.as_u64[1] = key4_0.as_u64[1];
          tunnel_index0 = last_tunnel_index = p0[0];
        }
        else
          tunnel_index0 = last_tunnel_index;
      }
      else /* is_ip6 */
      {
        next0 =
            (iuvn6_0->vxlan.protocol < VXLAN_GPE_PROTOCOL_MAX)?
            nngm->decap_next_node_list[iuvn6_0->vxlan.protocol]: \
            VXLAN_GPE_INPUT_NEXT_DROP;

        key6_0.local.as_u64[0] = iuvn6_0->ip6.dst_address.as_u64[0];
        key6_0.local.as_u64[1] = iuvn6_0->ip6.dst_address.as_u64[1];
        key6_0.remote.as_u64[0] = iuvn6_0->ip6.src_address.as_u64[0];
        key6_0.remote.as_u64[1] = iuvn6_0->ip6.src_address.as_u64[1];
        key6_0.vni = iuvn6_0->vxlan.vni_res;

        /* Processing for key6_0 */
        if (PREDICT_FALSE(memcmp (&key6_0, &last_key6, sizeof(last_key6)) != 0))
        {
          p0 = hash_get_mem(nngm->vxlan6_gpe_tunnel_by_key, &key6_0);

          if (p0 == 0)
          {
            error0 = VXLAN_GPE_ERROR_NO_SUCH_TUNNEL;
            goto trace00;
          }

          memcpy (&last_key6, &key6_0, sizeof(key6_0));
          tunnel_index0 = last_tunnel_index = p0[0];
        }
        else
          tunnel_index0 = last_tunnel_index;
      }

      t0 = pool_elt_at_index(nngm->tunnels, tunnel_index0);


      sw_if_index0 = t0->sw_if_index;
      len0 = vlib_buffer_length_in_chain (vm, b0);

      /* Required to make the l2 tag push / pop code work on l2 subifs */
      vnet_update_l2_len (b0);

      /*
       * ip[46] lookup in the configured FIB
       */
      vnet_buffer(b0)->sw_if_index[VLIB_TX] = t0->decap_fib_index;

      pkts_decapsulated++;
      stats_n_packets += 1;
      stats_n_bytes += len0;

      /* Batch stats increment on the same vxlan-gpe tunnel so counter
       is not incremented per packet */
      if (PREDICT_FALSE(sw_if_index0 != stats_sw_if_index))
      {
        stats_n_packets -= 1;
        stats_n_bytes -= len0;
        if (stats_n_packets)
          vlib_increment_combined_counter (
              im->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX,
              thread_index, stats_sw_if_index, stats_n_packets, stats_n_bytes);
        stats_n_packets = 1;
        stats_n_bytes = len0;
        stats_sw_if_index = sw_if_index0;
      }

      trace00: b0->error = error0 ? node->errors[error0] : 0;

      if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
      {
        vxlan_gpe_rx_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof(*tr));
        tr->next_index = next0;
        tr->error = error0;
        tr->tunnel_index = tunnel_index0;
      }
      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);
  }
  vlib_node_increment_counter (vm, vxlan_gpe_input_node.index,
                               VXLAN_GPE_ERROR_DECAPSULATED, pkts_decapsulated);
  /* Increment any remaining batch stats */
  if (stats_n_packets)
  {
    vlib_increment_combined_counter (
        im->combined_sw_if_counters + VNET_INTERFACE_COUNTER_RX, thread_index,
        stats_sw_if_index, stats_n_packets, stats_n_bytes);
    node->runtime_data[0] = stats_sw_if_index;
  }
  return from_frame->n_vectors;
}

/**
 * @brief Graph processing dispatch function for IPv4 VXLAN GPE
 *
 * @node vxlan4-gpe-input
 * @param *vm
 * @param *node
 * @param *from_frame
 *
 * @return from_frame->n_vectors
 *
 */
static uword
vxlan4_gpe_input (vlib_main_t * vm, vlib_node_runtime_t * node,
                  vlib_frame_t * from_frame)
{
  return vxlan_gpe_input (vm, node, from_frame, /* is_ip4 */1);
}


void
vxlan_gpe_register_decap_protocol (u8 protocol_id, uword next_node_index)
{
  vxlan_gpe_main_t *hm = &vxlan_gpe_main;
  hm->decap_next_node_list[protocol_id] = next_node_index;
  return;
}

void
vxlan_gpe_unregister_decap_protocol (u8 protocol_id, uword next_node_index)
{
  vxlan_gpe_main_t *hm = &vxlan_gpe_main;
  hm->decap_next_node_list[protocol_id] = VXLAN_GPE_INPUT_NEXT_DROP;
  return;
}


/**
 * @brief Graph processing dispatch function for IPv6 VXLAN GPE
 *
 * @node vxlan6-gpe-input
 * @param *vm
 * @param *node
 * @param *from_frame
 *
 * @return from_frame->n_vectors - uword
 *
 */
static uword
vxlan6_gpe_input (vlib_main_t * vm, vlib_node_runtime_t * node,
                  vlib_frame_t * from_frame)
{
  return vxlan_gpe_input (vm, node, from_frame, /* is_ip4 */0);
}

/**
 * @brief VXLAN GPE error strings
 */
static char * vxlan_gpe_error_strings[] = {
#define vxlan_gpe_error(n,s) s,
#include <vnet/vxlan-gpe/vxlan_gpe_error.def>
#undef vxlan_gpe_error
#undef _
};

VLIB_REGISTER_NODE (vxlan4_gpe_input_node) = {
  .function = vxlan4_gpe_input,
  .name = "vxlan4-gpe-input",
  /* Takes a vector of packets. */
  .vector_size = sizeof (u32),
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = ARRAY_LEN(vxlan_gpe_error_strings),
  .error_strings = vxlan_gpe_error_strings,

  .n_next_nodes = VXLAN_GPE_INPUT_N_NEXT,
  .next_nodes = {
#define _(s,n) [VXLAN_GPE_INPUT_NEXT_##s] = n,
    foreach_vxlan_gpe_input_next
#undef _
  },

  .format_buffer = format_vxlan_gpe_with_length,
  .format_trace = format_vxlan_gpe_rx_trace,
  // $$$$ .unformat_buffer = unformat_vxlan_gpe_header,
};

VLIB_NODE_FUNCTION_MULTIARCH (vxlan4_gpe_input_node, vxlan4_gpe_input);

VLIB_REGISTER_NODE (vxlan6_gpe_input_node) = {
  .function = vxlan6_gpe_input,
  .name = "vxlan6-gpe-input",
  /* Takes a vector of packets. */
  .vector_size = sizeof (u32),
  .type = VLIB_NODE_TYPE_INTERNAL,
  .n_errors = ARRAY_LEN(vxlan_gpe_error_strings),
  .error_strings = vxlan_gpe_error_strings,

  .n_next_nodes = VXLAN_GPE_INPUT_N_NEXT,
  .next_nodes = {
#define _(s,n) [VXLAN_GPE_INPUT_NEXT_##s] = n,
    foreach_vxlan_gpe_input_next
#undef _
  },

  .format_buffer = format_vxlan_gpe_with_length,
  .format_trace = format_vxlan_gpe_rx_trace,
  // $$$$ .unformat_buffer = unformat_vxlan_gpe_header,
};

VLIB_NODE_FUNCTION_MULTIARCH (vxlan6_gpe_input_node, vxlan6_gpe_input);
typedef enum {
  IP_VXLAN_BYPASS_NEXT_DROP,
  IP_VXLAN_BYPASS_NEXT_VXLAN,
  IP_VXLAN_BYPASS_N_NEXT,
} ip_vxan_bypass_next_t;

always_inline uword
ip_vxlan_gpe_bypass_inline (vlib_main_t * vm,
			vlib_node_runtime_t * node,
			vlib_frame_t * frame,
			u32 is_ip4)
{
  vxlan_gpe_main_t * ngm = &vxlan_gpe_main;
  u32 * from, * to_next, n_left_from, n_left_to_next, next_index;
  vlib_node_runtime_t * error_node = vlib_node_get_runtime (vm, ip4_input_node.index);
  ip4_address_t addr4; /* last IPv4 address matching a local VTEP address */
  ip6_address_t addr6; /* last IPv6 address matching a local VTEP address */

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  if (node->flags & VLIB_NODE_FLAG_TRACE)
    ip4_forward_next_trace (vm, node, frame, VLIB_TX);

  if (is_ip4) addr4.data_u32 = ~0;
  else ip6_address_set_zero (&addr6);

  while (n_left_from > 0)
    {
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from >= 4 && n_left_to_next >= 2)
      	{
      	  vlib_buffer_t * b0, * b1;
      	  ip4_header_t * ip40, * ip41;
      	  ip6_header_t * ip60, * ip61;
      	  udp_header_t * udp0, * udp1;
      	  u32 bi0, ip_len0, udp_len0, flags0, next0;
      	  u32 bi1, ip_len1, udp_len1, flags1, next1;
      	  i32 len_diff0, len_diff1;
      	  u8 error0, good_udp0, proto0;
      	  u8 error1, good_udp1, proto1;

	  /* Prefetch next iteration. */
	  {
	    vlib_buffer_t * p2, * p3;

	    p2 = vlib_get_buffer (vm, from[2]);
	    p3 = vlib_get_buffer (vm, from[3]);

	    vlib_prefetch_buffer_header (p2, LOAD);
	    vlib_prefetch_buffer_header (p3, LOAD);

	    CLIB_PREFETCH (p2->data, 2*CLIB_CACHE_LINE_BYTES, LOAD);
	    CLIB_PREFETCH (p3->data, 2*CLIB_CACHE_LINE_BYTES, LOAD);
	  }

      	  bi0 = to_next[0] = from[0];
      	  bi1 = to_next[1] = from[1];
      	  from += 2;
      	  n_left_from -= 2;
      	  to_next += 2;
      	  n_left_to_next -= 2;

	  b0 = vlib_get_buffer (vm, bi0);
	  b1 = vlib_get_buffer (vm, bi1);
	  if (is_ip4)
	    {
	      ip40 = vlib_buffer_get_current (b0);
	      ip41 = vlib_buffer_get_current (b1);
	    }
	  else
	    {
	      ip60 = vlib_buffer_get_current (b0);
	      ip61 = vlib_buffer_get_current (b1);
	    }

	  /* Setup packet for next IP feature */
	  vnet_feature_next(vnet_buffer(b0)->sw_if_index[VLIB_RX], &next0, b0);
	  vnet_feature_next(vnet_buffer(b1)->sw_if_index[VLIB_RX], &next1, b1);

	  if (is_ip4)
	    {
	      proto0 = ip40->protocol;
	      proto1 = ip41->protocol;
	    }
	  else
	    {
	      proto0 = ip60->protocol;
	      proto1 = ip61->protocol;
	    }

	  /* Process packet 0 */
	  if (proto0 != IP_PROTOCOL_UDP)
	    goto exit0; /* not UDP packet */

	  if (is_ip4)
	    udp0 = ip4_next_header (ip40);
	  else
	    udp0 = ip6_next_header (ip60);

	  if (udp0->dst_port != clib_host_to_net_u16 (UDP_DST_PORT_VXLAN_GPE))
	    goto exit0; /* not VXLAN packet */

	  /* Validate DIP against VTEPs*/
	  if (is_ip4)
	    {
	      if (addr4.as_u32 != ip40->dst_address.as_u32)
	        {
		  if (!hash_get (ngm->vtep4, ip40->dst_address.as_u32))
		      goto exit0; /* no local VTEP for VXLAN packet */
		  addr4 = ip40->dst_address;
	        }
	    }
	  else
	    {
	      if (!ip6_address_is_equal (&addr6, &ip60->dst_address))
	        {
		  if (!hash_get_mem (ngm->vtep6, &ip60->dst_address))
		      goto exit0; /* no local VTEP for VXLAN packet */
		  addr6 = ip60->dst_address;
	        }
	    }

	  flags0 = b0->flags;
	  good_udp0 = (flags0 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;

	  /* Don't verify UDP checksum for packets with explicit zero checksum. */
	  good_udp0 |= udp0->checksum == 0;

	  /* Verify UDP length */
	  if (is_ip4)
	    ip_len0 = clib_net_to_host_u16 (ip40->length);
	  else
	    ip_len0 = clib_net_to_host_u16 (ip60->payload_length);
	  udp_len0 = clib_net_to_host_u16 (udp0->length);
	  len_diff0 = ip_len0 - udp_len0;

	  /* Verify UDP checksum */
	  if (PREDICT_FALSE (!good_udp0))
	    {
	      if ((flags0 & IP_BUFFER_L4_CHECKSUM_COMPUTED) == 0)
	        {
		  if (is_ip4)
		    flags0 = ip4_tcp_udp_validate_checksum (vm, b0);
		  else
		    flags0 = ip6_tcp_udp_icmp_validate_checksum (vm, b0);
		  good_udp0 =
		    (flags0 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;
	        }
	    }

	  if (is_ip4)
	    {
	      error0 = good_udp0 ? 0 : IP4_ERROR_UDP_CHECKSUM;
	      error0 = (len_diff0 >= 0) ? error0 : IP4_ERROR_UDP_LENGTH;
	    }
	  else
	    {
	      error0 = good_udp0 ? 0 : IP6_ERROR_UDP_CHECKSUM;
	      error0 = (len_diff0 >= 0) ? error0 : IP6_ERROR_UDP_LENGTH;
	    }

	  next0 = error0 ?
	    IP_VXLAN_BYPASS_NEXT_DROP : IP_VXLAN_BYPASS_NEXT_VXLAN;
	  b0->error = error0 ? error_node->errors[error0] : 0;

	  /* vxlan_gpe-input node expect current at VXLAN header */
	  if (is_ip4)
	    vlib_buffer_advance (b0, sizeof(ip4_header_t)+sizeof(udp_header_t));
	  else
	    vlib_buffer_advance (b0, sizeof(ip6_header_t)+sizeof(udp_header_t));

	exit0:
	  /* Process packet 1 */
	  if (proto1 != IP_PROTOCOL_UDP)
	    goto exit1; /* not UDP packet */

	  if (is_ip4)
	    udp1 = ip4_next_header (ip41);
	  else
	    udp1 = ip6_next_header (ip61);

	  if (udp1->dst_port != clib_host_to_net_u16 (UDP_DST_PORT_VXLAN_GPE))
	    goto exit1; /* not VXLAN packet */

	  /* Validate DIP against VTEPs*/
	  if (is_ip4)
	    {
	      if (addr4.as_u32 != ip41->dst_address.as_u32)
	        {
		  if (!hash_get (ngm->vtep4, ip41->dst_address.as_u32))
		      goto exit1; /* no local VTEP for VXLAN packet */
		  addr4 = ip41->dst_address;
		}
	    }
	  else
	    {
	      if (!ip6_address_is_equal (&addr6, &ip61->dst_address))
	        {
		  if (!hash_get_mem (ngm->vtep6, &ip61->dst_address))
		      goto exit1; /* no local VTEP for VXLAN packet */
		  addr6 = ip61->dst_address;
		}
	    }

	  flags1 = b1->flags;
	  good_udp1 = (flags1 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;

	  /* Don't verify UDP checksum for packets with explicit zero checksum. */
	  good_udp1 |= udp1->checksum == 0;

	  /* Verify UDP length */
	  if (is_ip4)
	    ip_len1 = clib_net_to_host_u16 (ip41->length);
	  else
	    ip_len1 = clib_net_to_host_u16 (ip61->payload_length);
	  udp_len1 = clib_net_to_host_u16 (udp1->length);
	  len_diff1 = ip_len1 - udp_len1;

	  /* Verify UDP checksum */
	  if (PREDICT_FALSE (!good_udp1))
	    {
	      if ((flags1 & IP_BUFFER_L4_CHECKSUM_COMPUTED) == 0)
	        {
		  if (is_ip4)
		    flags1 = ip4_tcp_udp_validate_checksum (vm, b1);
		  else
		    flags1 = ip6_tcp_udp_icmp_validate_checksum (vm, b1);
		  good_udp1 =
		    (flags1 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;
	        }
	    }

	  if (is_ip4)
	    {
	      error1 = good_udp1 ? 0 : IP4_ERROR_UDP_CHECKSUM;
	      error1 = (len_diff1 >= 0) ? error1 : IP4_ERROR_UDP_LENGTH;
	    }
	  else
	    {
	      error1 = good_udp1 ? 0 : IP6_ERROR_UDP_CHECKSUM;
	      error1 = (len_diff1 >= 0) ? error1 : IP6_ERROR_UDP_LENGTH;
	    }

	  next1 = error1 ?
	    IP_VXLAN_BYPASS_NEXT_DROP : IP_VXLAN_BYPASS_NEXT_VXLAN;
	  b1->error = error1 ? error_node->errors[error1] : 0;

	  /* vxlan_gpe-input node expect current at VXLAN header */
	  if (is_ip4)
	    vlib_buffer_advance (b1, sizeof(ip4_header_t)+sizeof(udp_header_t));
	  else
	    vlib_buffer_advance (b1, sizeof(ip6_header_t)+sizeof(udp_header_t));

	exit1:
	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, bi1, next0, next1);
	}

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  vlib_buffer_t * b0;
	  ip4_header_t * ip40;
	  ip6_header_t * ip60;
	  udp_header_t * udp0;
      	  u32 bi0, ip_len0, udp_len0, flags0, next0;
	  i32 len_diff0;
	  u8 error0, good_udp0, proto0;

	  bi0 = to_next[0] = from[0];
	  from += 1;
	  n_left_from -= 1;
	  to_next += 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);
	  if (is_ip4)
	    ip40 = vlib_buffer_get_current (b0);
	  else
	    ip60 = vlib_buffer_get_current (b0);

	  /* Setup packet for next IP feature */
	  vnet_feature_next(vnet_buffer(b0)->sw_if_index[VLIB_RX], &next0, b0);

	  if (is_ip4)
	    proto0 = ip40->protocol;
	  else
	    proto0 = ip60->protocol;

	  if (proto0 != IP_PROTOCOL_UDP)
	    goto exit; /* not UDP packet */

	  if (is_ip4)
	    udp0 = ip4_next_header (ip40);
	  else
	    udp0 = ip6_next_header (ip60);

	  if (udp0->dst_port != clib_host_to_net_u16 (UDP_DST_PORT_VXLAN_GPE))
	    goto exit; /* not VXLAN packet */

	  /* Validate DIP against VTEPs*/
	  if (is_ip4)
	    {
	      if (addr4.as_u32 != ip40->dst_address.as_u32)
	        {
		  if (!hash_get (ngm->vtep4, ip40->dst_address.as_u32))
		      goto exit; /* no local VTEP for VXLAN packet */
		  addr4 = ip40->dst_address;
		}
	    }
	  else
	    {
	      if (!ip6_address_is_equal (&addr6, &ip60->dst_address))
	        {
		  if (!hash_get_mem (ngm->vtep6, &ip60->dst_address))
		      goto exit; /* no local VTEP for VXLAN packet */
		  addr6 = ip60->dst_address;
		}
	    }

	  flags0 = b0->flags;
	  good_udp0 = (flags0 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;

	  /* Don't verify UDP checksum for packets with explicit zero checksum. */
	  good_udp0 |= udp0->checksum == 0;

	  /* Verify UDP length */
	  if (is_ip4)
	    ip_len0 = clib_net_to_host_u16 (ip40->length);
	  else
	    ip_len0 = clib_net_to_host_u16 (ip60->payload_length);
	  udp_len0 = clib_net_to_host_u16 (udp0->length);
	  len_diff0 = ip_len0 - udp_len0;

	  /* Verify UDP checksum */
	  if (PREDICT_FALSE (!good_udp0))
	    {
	      if ((flags0 & IP_BUFFER_L4_CHECKSUM_COMPUTED) == 0)
	        {
		  if (is_ip4)
		    flags0 = ip4_tcp_udp_validate_checksum (vm, b0);
		  else
		    flags0 = ip6_tcp_udp_icmp_validate_checksum (vm, b0);
		  good_udp0 =
		    (flags0 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;
	        }
	    }

	  if (is_ip4)
	    {
	      error0 = good_udp0 ? 0 : IP4_ERROR_UDP_CHECKSUM;
	      error0 = (len_diff0 >= 0) ? error0 : IP4_ERROR_UDP_LENGTH;
	    }
	  else
	    {
	      error0 = good_udp0 ? 0 : IP6_ERROR_UDP_CHECKSUM;
	      error0 = (len_diff0 >= 0) ? error0 : IP6_ERROR_UDP_LENGTH;
	    }

	  next0 = error0 ?
	    IP_VXLAN_BYPASS_NEXT_DROP : IP_VXLAN_BYPASS_NEXT_VXLAN;
	  b0->error = error0 ? error_node->errors[error0] : 0;

	  /* vxlan_gpe-input node expect current at VXLAN header */
	  if (is_ip4)
	    vlib_buffer_advance (b0, sizeof(ip4_header_t)+sizeof(udp_header_t));
	  else
	    vlib_buffer_advance (b0, sizeof(ip6_header_t)+sizeof(udp_header_t));

	exit:
	  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;
}

static uword
ip4_vxlan_gpe_bypass (vlib_main_t * vm,
		  vlib_node_runtime_t * node,
		  vlib_frame_t * frame)
{
  return ip_vxlan_gpe_bypass_inline (vm, node, frame, /* is_ip4 */ 1);
}

VLIB_REGISTER_NODE (ip4_vxlan_gpe_bypass_node) = {
  .function = ip4_vxlan_gpe_bypass,
  .name = "ip4-vxlan-gpe-bypass",
  .vector_size = sizeof (u32),

  .n_next_nodes = IP_VXLAN_BYPASS_N_NEXT,
  .next_nodes = {
    [IP_VXLAN_BYPASS_NEXT_DROP] = "error-drop",
    [IP_VXLAN_BYPASS_NEXT_VXLAN] = "vxlan4-gpe-input",
  },

  .format_buffer = format_ip4_header,
  .format_trace = format_ip4_forward_next_trace,
};

VLIB_NODE_FUNCTION_MULTIARCH (ip4_vxlan_gpe_bypass_node,ip4_vxlan_gpe_bypass)

/* Dummy init function to get us linked in. */
clib_error_t * ip4_vxlan_gpe_bypass_init (vlib_main_t * vm)
{ return 0; }

VLIB_INIT_FUNCTION (ip4_vxlan_gpe_bypass_init);

static uword
ip6_vxlan_gpe_bypass (vlib_main_t * vm,
		  vlib_node_runtime_t * node,
		  vlib_frame_t * frame)
{
  return ip_vxlan_gpe_bypass_inline (vm, node, frame, /* is_ip4 */ 0);
}

VLIB_REGISTER_NODE (ip6_vxlan_gpe_bypass_node) = {
  .function = ip6_vxlan_gpe_bypass,
  .name = "ip6-vxlan-gpe-bypass",
  .vector_size = sizeof (u32),

  .n_next_nodes = IP_VXLAN_BYPASS_N_NEXT,
  .next_nodes = {
    [IP_VXLAN_BYPASS_NEXT_DROP] = "error-drop",
    [IP_VXLAN_BYPASS_NEXT_VXLAN] = "vxlan6-gpe-input",
  },

  .format_buffer = format_ip6_header,
  .format_trace = format_ip6_forward_next_trace,
};

VLIB_NODE_FUNCTION_MULTIARCH (ip6_vxlan_gpe_bypass_node,ip6_vxlan_gpe_bypass)

/* Dummy init function to get us linked in. */
clib_error_t * ip6_vxlan_gpe_bypass_init (vlib_main_t * vm)
{ return 0; }

VLIB_INIT_FUNCTION (ip6_vxlan_gpe_bypass_init);