src/vnet/vxlan/decap.c

/*
 * decap.c: vxlan tunnel decap packet processing
 *
 * 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.
 */

#include <vlib/vlib.h>
#include <vnet/pg/pg.h>
#include <vnet/vxlan/vxlan.h>

vlib_node_registration_t vxlan4_input_node;
vlib_node_registration_t vxlan6_input_node;

typedef struct {
  u32 next_index;
  u32 tunnel_index;
  u32 error;
  u32 vni;
} vxlan_rx_trace_t;

static u8 * format_vxlan_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_rx_trace_t * t = va_arg (*args, vxlan_rx_trace_t *);

  if (t->tunnel_index != ~0)
    {
      s = format (s, "VXLAN decap from vxlan_tunnel%d vni %d next %d error %d",
                  t->tunnel_index, t->vni, t->next_index, t->error);
    }
  else
    {
      s = format (s, "VXLAN decap error - tunnel for vni %d does not exist", 
		  t->vni);
    }
  return s;
}

always_inline u32
validate_vxlan_fib (vlib_buffer_t *b, vxlan_tunnel_t *t, u32 is_ip4)
{
  u32 sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];

  u32 * fib_index_by_sw_if_index = is_ip4 ?
    ip4_main.fib_index_by_sw_if_index : ip6_main.fib_index_by_sw_if_index;
  u32 tx_sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_TX];
  u32 fib_index = (tx_sw_if_index == (u32) ~ 0) ?
    vec_elt (fib_index_by_sw_if_index, sw_if_index) : tx_sw_if_index;

  return (fib_index == t->encap_fib_index);
}

always_inline uword
vxlan_input (vlib_main_t * vm,
             vlib_node_runtime_t * node,
             vlib_frame_t * from_frame,
             u32 is_ip4)
{
  vxlan_main_t * vxm = &vxlan_main;
  vnet_main_t * vnm = vxm->vnet_main;
  vnet_interface_main_t * im = &vnm->interface_main;
  u32 last_tunnel_index = ~0;
  vxlan4_tunnel_key_t last_key4;
  vxlan6_tunnel_key_t last_key6;
  u32 pkts_decapsulated = 0;
  u32 thread_index = vlib_get_thread_index();

  if (is_ip4)
    last_key4.as_u64 = ~0;
  else
    memset (&last_key6, 0xff, sizeof (last_key6));

  u32 next_index = node->cached_next_index;
  u32 stats_sw_if_index = node->runtime_data[0];
  u32 stats_n_packets = 0, stats_n_bytes = 0;

  u32 * from = vlib_frame_vector_args (from_frame);
  u32 n_left_from = from_frame->n_vectors;

  while (n_left_from > 0)
    {
      u32 * to_next, 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;
          vxlan_tunnel_t * t0, * t1, * stats_t0, * stats_t1;

	  /* 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);

          /* udp leaves current_data pointing at the vxlan header */
	  void * cur0 = vlib_buffer_get_current (b0);
	  void * cur1 = vlib_buffer_get_current (b1);
          vxlan_header_t * vxlan0 = cur0;
          vxlan_header_t * vxlan1 = cur1;

          ip4_header_t * ip4_0, * ip4_1;
          ip6_header_t * ip6_0, * ip6_1;
          if (is_ip4) {
            ip4_0 = cur0 - sizeof(udp_header_t) - sizeof(ip4_header_t);
            ip4_1 = cur1 - sizeof(udp_header_t) - sizeof(ip4_header_t);
	  } else {
            ip6_0 = cur0 - sizeof(udp_header_t) - sizeof(ip6_header_t);
            ip6_1 = cur1 - sizeof(udp_header_t) - sizeof(ip6_header_t);
	  }

          /* pop (ip, udp, vxlan) */
          vlib_buffer_advance (b0, sizeof *vxlan0);
	  vlib_buffer_advance (b1, sizeof *vxlan1);

          u32 tunnel_index0 = ~0, tunnel_index1 = ~0;
          u32 error0 = 0, error1 = 0;

	  if (PREDICT_FALSE (vxlan0->flags != VXLAN_FLAGS_I))
	    {
	      error0 = VXLAN_ERROR_BAD_FLAGS;
	      next0 = VXLAN_INPUT_NEXT_DROP;
	      goto trace0;
	    }


          if (is_ip4) {
 	    /* Make sure VXLAN tunnel exist according to packet SIP and VNI */
	    vxlan4_tunnel_key_t key4_0 = {
              .src = ip4_0->src_address.as_u32,
              .vni = vxlan0->vni_reserved,
	    };

           if (PREDICT_FALSE (key4_0.as_u64 != last_key4.as_u64))
              {
                uword * p = hash_get (vxm->vxlan4_tunnel_by_key, key4_0.as_u64);
                if (PREDICT_FALSE (p == NULL))
                  {
                    error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
                    next0 = VXLAN_INPUT_NEXT_DROP;
                    goto trace0;
                  }
                last_key4 = key4_0;
                last_tunnel_index = p[0];
              }
            tunnel_index0 = last_tunnel_index;
	    stats_t0 = t0 = pool_elt_at_index (vxm->tunnels, tunnel_index0);

	    /* Validate VXLAN tunnel encap-fib index agaist packet */
	    if (PREDICT_FALSE (validate_vxlan_fib (b0, t0, is_ip4) == 0))
	      {
		error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
		next0 = VXLAN_INPUT_NEXT_DROP;
		goto trace0;
	      }

	    /* Validate VXLAN tunnel SIP against packet DIP */
	    if (PREDICT_TRUE (ip4_0->dst_address.as_u32 == t0->src.ip4.as_u32))
	      goto next0; /* valid packet */
	    if (PREDICT_FALSE (ip4_address_is_multicast (&ip4_0->dst_address)))
	      {
		key4_0.src = ip4_0->dst_address.as_u32;
		/* Make sure mcast VXLAN tunnel exist by packet DIP and VNI */
		uword * p = hash_get (vxm->vxlan4_tunnel_by_key, key4_0.as_u64);
		if (PREDICT_TRUE (p != NULL))
		  {
		    stats_t0 = pool_elt_at_index (vxm->tunnels, p[0]);
		    goto next0; /* valid packet */
		  }
	      }
	    error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
	    next0 = VXLAN_INPUT_NEXT_DROP;
	    goto trace0;

         } else /* !is_ip4 */ {
 	    /* Make sure VXLAN tunnel exist according to packet SIP and VNI */
            vxlan6_tunnel_key_t key6_0 = {
	      .src = ip6_0->src_address,
	      .vni = vxlan0->vni_reserved,
	    };

            if (PREDICT_FALSE (memcmp(&key6_0, &last_key6, sizeof(last_key6)) != 0))
              {
                uword * p = hash_get_mem (vxm->vxlan6_tunnel_by_key, &key6_0);
                if (PREDICT_FALSE (p == NULL))
                  {
                    error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
                    next0 = VXLAN_INPUT_NEXT_DROP;
                    goto trace0;
                  }
                clib_memcpy (&last_key6, &key6_0, sizeof(key6_0));
                last_tunnel_index = p[0];
              }
            tunnel_index0 = last_tunnel_index;
	    stats_t0 = t0 = pool_elt_at_index (vxm->tunnels, tunnel_index0);

	    /* Validate VXLAN tunnel encap-fib index agaist packet */
	    if (PREDICT_FALSE (validate_vxlan_fib (b0, t0, is_ip4) == 0))
	      {
		error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
		next0 = VXLAN_INPUT_NEXT_DROP;
		goto trace0;
	      }

	    /* Validate VXLAN tunnel SIP against packet DIP */
	    if (PREDICT_TRUE (ip6_address_is_equal (&ip6_0->dst_address,
						    &t0->src.ip6)))
		goto next0; /* valid packet */
	    if (PREDICT_FALSE (ip6_address_is_multicast (&ip6_0->dst_address)))
	      {
		key6_0.src = ip6_0->dst_address;
		uword * p = hash_get_mem (vxm->vxlan6_tunnel_by_key, &key6_0);
		if (PREDICT_TRUE (p != NULL)) 
		  {
		    stats_t0 = pool_elt_at_index (vxm->tunnels, p[0]);
		    goto next0; /* valid packet */
		  }
	      }
	    error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
	    next0 = VXLAN_INPUT_NEXT_DROP;
	    goto trace0;
          }

	next0:
          next0 = t0->decap_next_index;
          u32 len0 = vlib_buffer_length_in_chain (vm, b0);

          /* Required to make the l2 tag push / pop code work on l2 subifs */
          if (PREDICT_TRUE(next0 == VXLAN_INPUT_NEXT_L2_INPUT))
            vnet_update_l2_len (b0);

          /* Set packet input sw_if_index to unicast VXLAN tunnel for learning */
          vnet_buffer(b0)->sw_if_index[VLIB_RX] = t0->sw_if_index;

	  /* Batch stats increment on the same vxlan tunnel so counter
	     is not incremented per packet */
	  u32 sw_if_index0 = stats_t0->sw_if_index;
	  if (PREDICT_FALSE (sw_if_index0 != stats_sw_if_index)) 
	    {
	      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);
                  pkts_decapsulated += stats_n_packets;
	          stats_n_packets = stats_n_bytes = 0;
	        }
	      stats_sw_if_index = sw_if_index0;
	    }
          stats_n_packets += 1;
          stats_n_bytes += len0;

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

          if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED)) 
            {
              vxlan_rx_trace_t *tr 
                = vlib_add_trace (vm, node, b0, sizeof (*tr));
              tr->next_index = next0;
              tr->error = error0;
              tr->tunnel_index = tunnel_index0;
              tr->vni = vnet_get_vni (vxlan0);
            }

	  if (PREDICT_FALSE (vxlan1->flags != VXLAN_FLAGS_I))
	    {
	      error1 = VXLAN_ERROR_BAD_FLAGS;
	      next1 = VXLAN_INPUT_NEXT_DROP;
	      goto trace1;
	    }

          if (is_ip4) {
	    /* Make sure VXLAN tunnel exist according to packet SIP and VNI */
	    vxlan4_tunnel_key_t key4_1 = {
              .src = ip4_1->src_address.as_u32,
              .vni = vxlan1->vni_reserved
	    };

	    if (PREDICT_FALSE (key4_1.as_u64 != last_key4.as_u64))
              {
                uword * p = hash_get (vxm->vxlan4_tunnel_by_key, key4_1.as_u64);
                if (PREDICT_FALSE (p == NULL))
                  {
                    error1 = VXLAN_ERROR_NO_SUCH_TUNNEL;
                    next1 = VXLAN_INPUT_NEXT_DROP;
                    goto trace1;
                  }
                last_key4 = key4_1;
                last_tunnel_index = p[0];
              }
            tunnel_index1 = last_tunnel_index;
 	    stats_t1 = t1 = pool_elt_at_index (vxm->tunnels, tunnel_index1);

	    /* Validate VXLAN tunnel encap-fib index against packet */
	    if (PREDICT_FALSE (validate_vxlan_fib (b1, t1, is_ip4) == 0))
	      {
		error1 = VXLAN_ERROR_NO_SUCH_TUNNEL;
		next1 = VXLAN_INPUT_NEXT_DROP;
		goto trace1;
	      }

	    /* Validate VXLAN tunnel SIP against packet DIP */
	    if (PREDICT_TRUE (ip4_1->dst_address.as_u32 == t1->src.ip4.as_u32))
	      goto next1; /* valid packet */
	    if (PREDICT_FALSE (ip4_address_is_multicast (&ip4_1->dst_address)))
	      {
		/* Make sure mcast VXLAN tunnel exist by packet DIP and VNI */
		key4_1.src = ip4_1->dst_address.as_u32;

		uword * p = hash_get (vxm->vxlan4_tunnel_by_key, key4_1.as_u64);
		if (PREDICT_TRUE (p != NULL))
		  {
		    stats_t1 = pool_elt_at_index (vxm->tunnels, p[0]);
		    goto next1; /* valid packet */
		  }
	      }
	    error1 = VXLAN_ERROR_NO_SUCH_TUNNEL;
	    next1 = VXLAN_INPUT_NEXT_DROP;
	    goto trace1;

         } else /* !is_ip4 */ {
	    /* Make sure VXLAN tunnel exist according to packet SIP and VNI */
            vxlan6_tunnel_key_t key6_1 = {
	      .src = ip6_1->src_address,
	      .vni = vxlan1->vni_reserved,
	    };

            if (PREDICT_FALSE (memcmp(&key6_1, &last_key6, sizeof(last_key6)) != 0))
              {
                uword * p = hash_get_mem (vxm->vxlan6_tunnel_by_key, &key6_1);
                if (PREDICT_FALSE (p == NULL))
                  {
                    error1 = VXLAN_ERROR_NO_SUCH_TUNNEL;
                    next1 = VXLAN_INPUT_NEXT_DROP;
                    goto trace1;
                  }

                clib_memcpy (&last_key6, &key6_1, sizeof(key6_1));
                last_tunnel_index = p[0];
              }
            tunnel_index1 = last_tunnel_index;
 	    stats_t1 = t1 = pool_elt_at_index (vxm->tunnels, tunnel_index1);

	    /* Validate VXLAN tunnel encap-fib index agaist packet */
	    if (PREDICT_FALSE (validate_vxlan_fib (b1, t1, is_ip4) == 0))
	      {
		error1 = VXLAN_ERROR_NO_SUCH_TUNNEL;
		next1 = VXLAN_INPUT_NEXT_DROP;
		goto trace1;
	      }

	    /* Validate VXLAN tunnel SIP against packet DIP */
	    if (PREDICT_TRUE (ip6_address_is_equal (&ip6_1->dst_address,
						    &t1->src.ip6)))
		goto next1; /* valid packet */
	    if (PREDICT_FALSE (ip6_address_is_multicast (&ip6_1->dst_address)))
	      {
		key6_1.src = ip6_1->dst_address;

		uword * p = hash_get_mem (vxm->vxlan6_tunnel_by_key, &key6_1);
		if (PREDICT_TRUE (p != NULL)) 
		  {
		    stats_t1 = pool_elt_at_index (vxm->tunnels, p[0]);
		    goto next1; /* valid packet */
		  }
	      }
	    error1 = VXLAN_ERROR_NO_SUCH_TUNNEL;
	    next1 = VXLAN_INPUT_NEXT_DROP;
	    goto trace1;
	  }

	next1:
          next1 = t1->decap_next_index;
          u32 len1 = vlib_buffer_length_in_chain (vm, b1);

          /* Required to make the l2 tag push / pop code work on l2 subifs */
          if (PREDICT_TRUE(next1 == VXLAN_INPUT_NEXT_L2_INPUT))
            vnet_update_l2_len (b1);

          /* Set packet input sw_if_index to unicast VXLAN tunnel for learning */
          vnet_buffer(b1)->sw_if_index[VLIB_RX] = t1->sw_if_index;

	  /* Batch stats increment on the same vxlan tunnel so counter
	     is not incremented per packet */
	  u32 sw_if_index1 = stats_t1->sw_if_index;
	  if (PREDICT_FALSE (sw_if_index1 != stats_sw_if_index)) 
	    {
	      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);
                  pkts_decapsulated += stats_n_packets;
	          stats_n_packets = stats_n_bytes = 0;
	        }
	      stats_sw_if_index = sw_if_index1;
	    }
          stats_n_packets += 1;
          stats_n_bytes += len1;

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

          if (PREDICT_FALSE(b1->flags & VLIB_BUFFER_IS_TRACED)) 
            {
              vxlan_rx_trace_t *tr 
                = vlib_add_trace (vm, node, b1, sizeof (*tr));
              tr->next_index = next1;
              tr->error = error1;
              tr->tunnel_index = tunnel_index1;
              tr->vni = vnet_get_vni (vxlan1);
            }

	  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_header_t * ip4_0;
          ip6_header_t * ip6_0;
          vxlan_tunnel_t * t0, * stats_t0;

	  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);

          /* udp leaves current_data pointing at the vxlan header */
          void * cur0 = vlib_buffer_get_current (b0);
          vxlan_header_t * vxlan0 = cur0;
          if (is_ip4)
            ip4_0 = cur0 -sizeof(udp_header_t) - sizeof(ip4_header_t);
          else
            ip6_0 = cur0 -sizeof(udp_header_t) - sizeof(ip6_header_t);

          /* pop (ip, udp, vxlan) */
          vlib_buffer_advance (b0, sizeof(*vxlan0));

          u32 tunnel_index0 = ~0;
          u32 error0 = 0;

	  if (PREDICT_FALSE (vxlan0->flags != VXLAN_FLAGS_I))
	    {
	      error0 = VXLAN_ERROR_BAD_FLAGS;
	      next0 = VXLAN_INPUT_NEXT_DROP;
	      goto trace00;
	    }

          if (is_ip4) {
            vxlan4_tunnel_key_t key4_0 = {
              .src = ip4_0->src_address.as_u32,
              .vni = vxlan0->vni_reserved,
	    };

	    /* Make sure unicast VXLAN tunnel exist by packet SIP and VNI */
            if (PREDICT_FALSE (key4_0.as_u64 != last_key4.as_u64))
              {
                uword * p = hash_get (vxm->vxlan4_tunnel_by_key, key4_0.as_u64);
                if (PREDICT_FALSE (p == NULL))
                  {
                    error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
                    next0 = VXLAN_INPUT_NEXT_DROP;
                    goto trace00;
                  }
                last_key4 = key4_0;
                last_tunnel_index = p[0];
              }
            tunnel_index0 = last_tunnel_index;
	    stats_t0 = t0 = pool_elt_at_index (vxm->tunnels, tunnel_index0);

	    /* Validate VXLAN tunnel encap-fib index agaist packet */
	    if (PREDICT_FALSE (validate_vxlan_fib (b0, t0, is_ip4) == 0))
	      {
		error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
		next0 = VXLAN_INPUT_NEXT_DROP;
		goto trace00;
	      }

	    /* Validate VXLAN tunnel SIP against packet DIP */
	    if (PREDICT_TRUE (ip4_0->dst_address.as_u32 == t0->src.ip4.as_u32))
	      goto next00; /* valid packet */
	    if (PREDICT_FALSE (ip4_address_is_multicast (&ip4_0->dst_address)))
	      {
		/* Make sure mcast VXLAN tunnel exist by packet DIP and VNI */
		key4_0.src = ip4_0->dst_address.as_u32;
		uword * p = hash_get (vxm->vxlan4_tunnel_by_key, key4_0.as_u64);
		if (PREDICT_TRUE (p != NULL))
		  {
		    stats_t0 = pool_elt_at_index (vxm->tunnels, p[0]);
		    goto next00; /* valid packet */
		  }
	      }
	    error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
	    next0 = VXLAN_INPUT_NEXT_DROP;
	    goto trace00;

          } else /* !is_ip4 */ {
	    /* Make sure VXLAN tunnel exist according to packet SIP and VNI */
            vxlan6_tunnel_key_t key6_0 = {
              .src = ip6_0->src_address,
              .vni = vxlan0->vni_reserved,
	    };

            if (PREDICT_FALSE (memcmp(&key6_0, &last_key6, sizeof(last_key6)) != 0))
              {
                uword * p = hash_get_mem (vxm->vxlan6_tunnel_by_key, &key6_0);
                if (PREDICT_FALSE (p == NULL))
                  {
                    error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
                    next0 = VXLAN_INPUT_NEXT_DROP;
                    goto trace00;
                  }
                clib_memcpy (&last_key6, &key6_0, sizeof(key6_0));
                last_tunnel_index = p[0];
              }
            tunnel_index0 = last_tunnel_index;
	    stats_t0 = t0 = pool_elt_at_index (vxm->tunnels, tunnel_index0);

	    /* Validate VXLAN tunnel encap-fib index agaist packet */
	    if (PREDICT_FALSE (validate_vxlan_fib (b0, t0, is_ip4) == 0))
	      {
		error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
		next0 = VXLAN_INPUT_NEXT_DROP;
		goto trace00;
	      }

	    /* Validate VXLAN tunnel SIP against packet DIP */
	    if (PREDICT_TRUE (ip6_address_is_equal (&ip6_0->dst_address,
						    &t0->src.ip6)))
		goto next00; /* valid packet */
	    if (PREDICT_FALSE (ip6_address_is_multicast (&ip6_0->dst_address)))
	      {
		key6_0.src = ip6_0->dst_address;
		uword * p = hash_get_mem (vxm->vxlan6_tunnel_by_key, &key6_0);
		if (PREDICT_TRUE (p != NULL)) 
		  {
		    stats_t0 = pool_elt_at_index (vxm->tunnels, p[0]);
		    goto next00; /* valid packet */
		  }
	      }
	    error0 = VXLAN_ERROR_NO_SUCH_TUNNEL;
	    next0 = VXLAN_INPUT_NEXT_DROP;
	    goto trace00;
          }

	next00:
          next0 = t0->decap_next_index;
          u32 len0 = vlib_buffer_length_in_chain (vm, b0);

          /* Required to make the l2 tag push / pop code work on l2 subifs */
          if (PREDICT_TRUE(next0 == VXLAN_INPUT_NEXT_L2_INPUT))
            vnet_update_l2_len (b0);

          /* Set packet input sw_if_index to unicast VXLAN tunnel for learning */
          vnet_buffer(b0)->sw_if_index[VLIB_RX] = t0->sw_if_index;

	  /* Batch stats increment on the same vxlan tunnel so counter
	     is not incremented per packet */
	  u32 sw_if_index0 = stats_t0->sw_if_index;
	  if (PREDICT_FALSE (sw_if_index0 != stats_sw_if_index)) 
	    {
	      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);
                  pkts_decapsulated += stats_n_packets;
	          stats_n_packets = stats_n_bytes = 0;
	        }
	      stats_sw_if_index = sw_if_index0;
	    }
          stats_n_packets += 1;
          stats_n_bytes += len0;


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

          if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED)) 
            {
              vxlan_rx_trace_t *tr 
                = vlib_add_trace (vm, node, b0, sizeof (*tr));
              tr->next_index = next0;
              tr->error = error0;
              tr->tunnel_index = tunnel_index0;
              tr->vni = vnet_get_vni (vxlan0);
            }
	  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);
    }
  /* Increment any remaining batch stats */
  if (stats_n_packets)
    {
      pkts_decapsulated += 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;
    }

  /* Do we still need this now that tunnel tx stats is kept? */
  u32 node_idx = is_ip4 ? vxlan4_input_node.index : vxlan6_input_node.index;
  vlib_node_increment_counter (vm, node_idx, VXLAN_ERROR_DECAPSULATED,
                               pkts_decapsulated);

  return from_frame->n_vectors;
}

static uword
vxlan4_input (vlib_main_t * vm,
             vlib_node_runtime_t * node,
             vlib_frame_t * from_frame)
{
	return vxlan_input(vm, node, from_frame, /* is_ip4 */ 1);
}

static uword
vxlan6_input (vlib_main_t * vm,
             vlib_node_runtime_t * node,
             vlib_frame_t * from_frame)
{
	return vxlan_input(vm, node, from_frame, /* is_ip4 */ 0);
}

static char * vxlan_error_strings[] = {
#define vxlan_error(n,s) s,
#include <vnet/vxlan/vxlan_error.def>
#undef vxlan_error
#undef _
};

VLIB_REGISTER_NODE (vxlan4_input_node) = {
  .function = vxlan4_input,
  .name = "vxlan4-input",
  /* Takes a vector of packets. */
  .vector_size = sizeof (u32),

  .n_errors = VXLAN_N_ERROR,
  .error_strings = vxlan_error_strings,

  .n_next_nodes = VXLAN_INPUT_N_NEXT,
  .next_nodes = {
#define _(s,n) [VXLAN_INPUT_NEXT_##s] = n,
    foreach_vxlan_input_next
#undef _
  },

//temp  .format_buffer = format_vxlan_header,
  .format_trace = format_vxlan_rx_trace,
  // $$$$ .unformat_buffer = unformat_vxlan_header,
};

VLIB_NODE_FUNCTION_MULTIARCH (vxlan4_input_node, vxlan4_input)

VLIB_REGISTER_NODE (vxlan6_input_node) = {
  .function = vxlan6_input,
  .name = "vxlan6-input",
  /* Takes a vector of packets. */
  .vector_size = sizeof (u32),

  .n_errors = VXLAN_N_ERROR,
  .error_strings = vxlan_error_strings,

  .n_next_nodes = VXLAN_INPUT_N_NEXT,
  .next_nodes = {
#define _(s,n) [VXLAN_INPUT_NEXT_##s] = n,
    foreach_vxlan_input_next
#undef _
  },

//temp  .format_buffer = format_vxlan_header,
  .format_trace = format_vxlan_rx_trace,
  // $$$$ .unformat_buffer = unformat_vxlan_header,
};

VLIB_NODE_FUNCTION_MULTIARCH (vxlan6_input_node, vxlan6_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_bypass_inline (vlib_main_t * vm,
			vlib_node_runtime_t * node,
			vlib_frame_t * frame,
			u32 is_ip4)
{
  vxlan_main_t * vxm = &vxlan_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)
	    {
	      /* Treat IP frag packets as "experimental" protocol for now
		 until support of IP frag reassembly is implemented */
	      proto0 = ip4_is_fragment(ip40) ? 0xfe : ip40->protocol;
	      proto1 = ip4_is_fragment(ip41) ? 0xfe : 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))
	    goto exit0; /* not VXLAN packet */

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

	  flags0 = b0->flags;
	  good_udp0 = (flags0 & VNET_BUFFER_F_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 & VNET_BUFFER_F_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 & VNET_BUFFER_F_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-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))
	    goto exit1; /* not VXLAN packet */

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

	  flags1 = b1->flags;
	  good_udp1 = (flags1 & VNET_BUFFER_F_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 & VNET_BUFFER_F_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 & VNET_BUFFER_F_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-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)
	    /* Treat IP4 frag packets as "experimental" protocol for now
	       until support of IP frag reassembly is implemented */
	    proto0 = ip4_is_fragment(ip40) ? 0xfe : 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))
	    goto exit; /* not VXLAN packet */

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

	  flags0 = b0->flags;
	  good_udp0 = (flags0 & VNET_BUFFER_F_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 & VNET_BUFFER_F_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 & VNET_BUFFER_F_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-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_bypass (vlib_main_t * vm,
		  vlib_node_runtime_t * node,
		  vlib_frame_t * frame)
{
  return ip_vxlan_bypass_inline (vm, node, frame, /* is_ip4 */ 1);
}

VLIB_REGISTER_NODE (ip4_vxlan_bypass_node) = {
  .function = ip4_vxlan_bypass,
  .name = "ip4-vxlan-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-input",
  },

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

VLIB_NODE_FUNCTION_MULTIARCH (ip4_vxlan_bypass_node,ip4_vxlan_bypass)

/* Dummy init function to get us linked in. */
clib_error_t * ip4_vxlan_bypass_init (vlib_main_t * vm)
{ return 0; }

VLIB_INIT_FUNCTION (ip4_vxlan_bypass_init);

static uword
ip6_vxlan_bypass (vlib_main_t * vm,
		  vlib_node_runtime_t * node,
		  vlib_frame_t * frame)
{
  return ip_vxlan_bypass_inline (vm, node, frame, /* is_ip4 */ 0);
}

VLIB_REGISTER_NODE (ip6_vxlan_bypass_node) = {
  .function = ip6_vxlan_bypass,
  .name = "ip6-vxlan-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-input",
  },

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

VLIB_NODE_FUNCTION_MULTIARCH (ip6_vxlan_bypass_node,ip6_vxlan_bypass)

/* Dummy init function to get us linked in. */
clib_error_t * ip6_vxlan_bypass_init (vlib_main_t * vm)
{ return 0; }

VLIB_INIT_FUNCTION (ip6_vxlan_bypass_init);