src/vnet/vxlan-gpe/encap.c - fdio/vpp - Gitiles

 /*
  * 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.
  */
 /**
  *  @file
  *  @brief Functions for encapsulating VXLAN GPE tunnels
  *
 */
 #include <vppinfra/error.h>
 #include <vppinfra/hash.h>
 #include <vnet/vnet.h>
 #include <vnet/ip/ip.h>
 #include <vnet/ethernet/ethernet.h>
 #include <vnet/udp/udp_inlines.h>
 #include <vnet/vxlan-gpe/vxlan_gpe.h>

 /** Statistics (not really errors) */
 #define foreach_vxlan_gpe_encap_error    \
 _(ENCAPSULATED, "good packets encapsulated")

 /**
  * @brief VXLAN GPE encap error strings
  */
 static char *vxlan_gpe_encap_error_strings[] = {
 #define _(sym,string) string,
   foreach_vxlan_gpe_encap_error
 #undef _
 };

 /**
  * @brief Struct for VXLAN GPE errors/counters
  */
 typedef enum
 {
 #define _(sym,str) VXLAN_GPE_ENCAP_ERROR_##sym,
   foreach_vxlan_gpe_encap_error
 #undef _
     VXLAN_GPE_ENCAP_N_ERROR,
 } vxlan_gpe_encap_error_t;

 /**
  * @brief Struct for tracing VXLAN GPE encapsulated packets
  */
 typedef struct
 {
   u32 tunnel_index;
 } vxlan_gpe_encap_trace_t;

 /**
  * @brief Trace of packets encapsulated in VXLAN GPE
  *
  * @param *s
  * @param *args
  *
  * @return *s
  *
  */
 u8 *
 format_vxlan_gpe_encap_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_encap_trace_t *t = va_arg (*args, vxlan_gpe_encap_trace_t *);

   s = format (s, "VXLAN-GPE-ENCAP: tunnel %d", t->tunnel_index);
   return s;
 }

 /**
  * @brief Instantiates UDP + VXLAN-GPE header then set next node to IP4|6 lookup
  *
  * @param *ngm
  * @param *b0
  * @param *t0 contains rewrite header
  * @param *next0 relative index of next dispatch function (next node)
  * @param is_v4 Is this IPv4? (or IPv6)
  *
  */
 always_inline void
 vxlan_gpe_encap_one_inline (vxlan_gpe_main_t * ngm, vlib_buffer_t * b0,
 			    vxlan_gpe_tunnel_t * t0, u32 * next0, u8 is_v4)
 {
   ASSERT (sizeof (ip4_vxlan_gpe_header_t) == 36);
   ASSERT (sizeof (ip6_vxlan_gpe_header_t) == 56);

   ip_udp_encap_one (ngm->vlib_main, b0, t0->rewrite, t0->rewrite_size, is_v4);
   next0[0] = t0->encap_next_node;
 }

 /**
  * @brief Instantiates UDP + VXLAN-GPE header then set next node to IP4|6 lookup for two packets
  *
  * @param *ngm
  * @param *b0 Packet0
  * @param *b1 Packet1
  * @param *t0 contains rewrite header for Packet0
  * @param *t1 contains rewrite header for Packet1
  * @param *next0 relative index of next dispatch function (next node) for Packet0
  * @param *next1 relative index of next dispatch function (next node) for Packet1
  * @param is_v4 Is this IPv4? (or IPv6)
  *
  */
 always_inline void
 vxlan_gpe_encap_two_inline (vxlan_gpe_main_t * ngm, vlib_buffer_t * b0,
 			    vlib_buffer_t * b1, vxlan_gpe_tunnel_t * t0,
 			    vxlan_gpe_tunnel_t * t1, u32 * next0,
 			    u32 * next1, u8 is_v4)
 {
   ASSERT (sizeof (ip4_vxlan_gpe_header_t) == 36);
   ASSERT (sizeof (ip6_vxlan_gpe_header_t) == 56);

   ip_udp_encap_one (ngm->vlib_main, b0, t0->rewrite, t0->rewrite_size, is_v4);
   ip_udp_encap_one (ngm->vlib_main, b1, t1->rewrite, t1->rewrite_size, is_v4);
   next0[0] = next1[0] = t0->encap_next_node;
 }

 /**
  * @brief Common processing for IPv4 and IPv6 VXLAN GPE encap dispatch functions
  *
  * It is worth noting that other than trivial UDP forwarding (transit), VXLAN GPE
  * tunnels are "establish local". This means that we don't have a TX interface as yet
  * as we need to look up where the outer-header dest is. By setting the TX index in the
  * buffer metadata to the encap FIB, we can do a lookup to get the adjacency and real TX.
  *
  *      vnet_buffer(b0)->sw_if_index[VLIB_TX] = t0->encap_fib_index;
  *
  * @node vxlan-gpe-input
  * @param *vm
  * @param *node
  * @param *from_frame
  *
  * @return from_frame->n_vectors
  *
  */
 static uword
 vxlan_gpe_encap (vlib_main_t * vm,
 		 vlib_node_runtime_t * node, vlib_frame_t * from_frame)
 {
   u32 n_left_from, next_index, *from, *to_next;
   vxlan_gpe_main_t *ngm = &vxlan_gpe_main;
   vnet_main_t *vnm = ngm->vnet_main;
   vnet_interface_main_t *im = &vnm->interface_main;
   u32 pkts_encapsulated = 0;
   u32 thread_index = vm->thread_index;
   u32 stats_sw_if_index, stats_n_packets, stats_n_bytes;
   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;

   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;
   vlib_get_buffers (vm, from, bufs, n_left_from);

   while (n_left_from > 0)
     {
       u32 n_left_to_next;
       u32 sw_if_index0 = ~0, sw_if_index1 = ~0, len0, len1;
       vnet_hw_interface_t *hi0, *hi1;
       vxlan_gpe_tunnel_t *t0 = NULL, *t1 = NULL;
       u8 is_ip4_0 = 0, is_ip4_1 = 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)
 	{
 	  u32 bi0, bi1;
 	  u32 next0, next1;

 	  next0 = next1 = VXLAN_GPE_ENCAP_NEXT_IP4_LOOKUP;

 	  /* Prefetch next iteration. */
 	  {
 	    vlib_prefetch_buffer_header (b[2], LOAD);
 	    vlib_prefetch_buffer_header (b[3], LOAD);

 	    CLIB_PREFETCH (b[2]->data - CLIB_CACHE_LINE_BYTES,
 			   2 * CLIB_CACHE_LINE_BYTES, LOAD);
 	    CLIB_PREFETCH (b[3]->data - CLIB_CACHE_LINE_BYTES,
 			   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;

 	  /* get the flag "is_ip4" */
 	  if (sw_if_index0 != vnet_buffer (b[0])->sw_if_index[VLIB_TX])
 	    {
 	      sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_TX];
 	      hi0 =
 		vnet_get_sup_hw_interface (vnm,
 					   vnet_buffer (b[0])->sw_if_index
 					   [VLIB_TX]);
 	      t0 = pool_elt_at_index (ngm->tunnels, hi0->dev_instance);
 	      is_ip4_0 = (t0->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
 	    }

 	  /* get the flag "is_ip4" */
 	  if (sw_if_index1 != vnet_buffer (b[1])->sw_if_index[VLIB_TX])
 	    {
 	      if (sw_if_index0 == vnet_buffer (b[1])->sw_if_index[VLIB_TX])
 		{
 		  sw_if_index1 = sw_if_index0;
 		  hi1 = hi0;
 		  t1 = t0;
 		  is_ip4_1 = is_ip4_0;
 		}
 	      else
 		{
 		  sw_if_index1 = vnet_buffer (b[1])->sw_if_index[VLIB_TX];
 		  hi1 =
 		    vnet_get_sup_hw_interface (vnm,
 					       vnet_buffer (b[1])->sw_if_index
 					       [VLIB_TX]);
 		  t1 = pool_elt_at_index (ngm->tunnels, hi1->dev_instance);
 		  is_ip4_1 = (t1->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
 		}
 	    }

 	  if (PREDICT_TRUE (is_ip4_0 == is_ip4_1))
 	    {
 	      vxlan_gpe_encap_two_inline (ngm, b[0], b[1], t0, t1, &next0,
 					  &next1, is_ip4_0);
 	    }
 	  else
 	    {
 	      vxlan_gpe_encap_one_inline (ngm, b[0], t0, &next0, is_ip4_0);
 	      vxlan_gpe_encap_one_inline (ngm, b[1], t1, &next1, is_ip4_1);
 	    }

 	  /* Reset to look up tunnel partner in the configured FIB */
 	  vnet_buffer (b[0])->sw_if_index[VLIB_TX] = t0->encap_fib_index;
 	  vnet_buffer (b[1])->sw_if_index[VLIB_TX] = t1->encap_fib_index;
 	  vnet_buffer (b[0])->sw_if_index[VLIB_RX] = sw_if_index0;
 	  vnet_buffer (b[1])->sw_if_index[VLIB_RX] = sw_if_index1;
 	  pkts_encapsulated += 2;

 	  len0 = vlib_buffer_length_in_chain (vm, b[0]);
 	  len1 = vlib_buffer_length_in_chain (vm, b[1]);
 	  stats_n_packets += 2;
 	  stats_n_bytes += len0 + len1;

 	  /* Batch stats increment on the same vxlan tunnel so counter is not
 	     incremented per packet. Note stats are still incremented for deleted
 	     and admin-down tunnel where packets are dropped. It is not worthwhile
 	     to check for this rare case and affect normal path performance. */
 	  if (PREDICT_FALSE ((sw_if_index0 != stats_sw_if_index)
 			     || (sw_if_index1 != stats_sw_if_index)))
 	    {
 	      stats_n_packets -= 2;
 	      stats_n_bytes -= len0 + len1;
 	      if (sw_if_index0 == sw_if_index1)
 		{
 		  if (stats_n_packets)
 		    vlib_increment_combined_counter
 		      (im->combined_sw_if_counters +
 		       VNET_INTERFACE_COUNTER_TX, thread_index,
 		       stats_sw_if_index, stats_n_packets, stats_n_bytes);
 		  stats_sw_if_index = sw_if_index0;
 		  stats_n_packets = 2;
 		  stats_n_bytes = len0 + len1;
 		}
 	      else
 		{
 		  vlib_increment_combined_counter (im->combined_sw_if_counters
 						   +
 						   VNET_INTERFACE_COUNTER_TX,
 						   thread_index, sw_if_index0,
 						   1, len0);
 		  vlib_increment_combined_counter (im->combined_sw_if_counters
 						   +
 						   VNET_INTERFACE_COUNTER_TX,
 						   thread_index, sw_if_index1,
 						   1, len1);
 		}
 	    }

 	  if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      vxlan_gpe_encap_trace_t *tr =
 		vlib_add_trace (vm, node, b[0], sizeof (*tr));
 	      tr->tunnel_index = t0 - ngm->tunnels;
 	    }

 	  if (PREDICT_FALSE (b[1]->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      vxlan_gpe_encap_trace_t *tr = vlib_add_trace (vm, node, b[1],
 							    sizeof (*tr));
 	      tr->tunnel_index = t1 - ngm->tunnels;
 	    }
 	  b += 2;

 	  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;
 	  u32 next0 = VXLAN_GPE_ENCAP_NEXT_IP4_LOOKUP;

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

 	  /* get the flag "is_ip4" */
 	  if (sw_if_index0 != vnet_buffer (b[0])->sw_if_index[VLIB_TX])
 	    {
 	      sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_TX];
 	      hi0 =
 		vnet_get_sup_hw_interface (vnm,
 					   vnet_buffer (b[0])->sw_if_index
 					   [VLIB_TX]);

 	      t0 = pool_elt_at_index (ngm->tunnels, hi0->dev_instance);

 	      is_ip4_0 = (t0->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
 	    }

 	  vxlan_gpe_encap_one_inline (ngm, b[0], t0, &next0, is_ip4_0);

 	  /* Reset to look up tunnel partner in the configured FIB */
 	  vnet_buffer (b[0])->sw_if_index[VLIB_TX] = t0->encap_fib_index;
 	  vnet_buffer (b[0])->sw_if_index[VLIB_RX] = sw_if_index0;
 	  pkts_encapsulated++;

 	  len0 = vlib_buffer_length_in_chain (vm, b[0]);
 	  stats_n_packets += 1;
 	  stats_n_bytes += len0;

 	  /* Batch stats increment on the same vxlan tunnel so counter is not
 	   *  incremented per packet. Note stats are still incremented for deleted
 	   *  and admin-down tunnel where packets are dropped. It is not worthwhile
 	   *  to check for this rare case and affect normal path performance. */
 	  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_TX,
 						 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;
 	    }
 	  if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
 	    {
 	      vxlan_gpe_encap_trace_t *tr = vlib_add_trace (vm, node, b[0],
 							    sizeof (*tr));
 	      tr->tunnel_index = t0 - ngm->tunnels;
 	    }
 	  b += 1;

 	  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, node->node_index,
 			       VXLAN_GPE_ENCAP_ERROR_ENCAPSULATED,
 			       pkts_encapsulated);
   /* Increment any remaining batch stats */
   if (stats_n_packets)
     {
       vlib_increment_combined_counter (im->combined_sw_if_counters +
 				       VNET_INTERFACE_COUNTER_TX,
 				       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;
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (vxlan_gpe_encap_node) = {
   .function = vxlan_gpe_encap,
   .name = "vxlan-gpe-encap",
   .vector_size = sizeof (u32),
   .format_trace = format_vxlan_gpe_encap_trace,
   .type = VLIB_NODE_TYPE_INTERNAL,

   .n_errors = ARRAY_LEN(vxlan_gpe_encap_error_strings),
   .error_strings = vxlan_gpe_encap_error_strings,

   .n_next_nodes = VXLAN_GPE_ENCAP_N_NEXT,

   .next_nodes = {
     [VXLAN_GPE_ENCAP_NEXT_IP4_LOOKUP] = "ip4-lookup",
     [VXLAN_GPE_ENCAP_NEXT_IP6_LOOKUP] = "ip6-lookup",
     [VXLAN_GPE_ENCAP_NEXT_DROP] = "error-drop",
   },
 };
 /* *INDENT-ON* */


 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* 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.
	*/
	/**
	* @file
	* @brief Functions for encapsulating VXLAN GPE tunnels
	*
	*/
	#include <vppinfra/error.h>
	#include <vppinfra/hash.h>
	#include <vnet/vnet.h>
	#include <vnet/ip/ip.h>
	#include <vnet/ethernet/ethernet.h>
	#include <vnet/udp/udp_inlines.h>
	#include <vnet/vxlan-gpe/vxlan_gpe.h>

	/** Statistics (not really errors) */
	#define foreach_vxlan_gpe_encap_error \
	_(ENCAPSULATED, "good packets encapsulated")

	/**
	* @brief VXLAN GPE encap error strings
	*/
	static char *vxlan_gpe_encap_error_strings[] = {
	#define _(sym,string) string,
	foreach_vxlan_gpe_encap_error
	#undef _
	};

	/**
	* @brief Struct for VXLAN GPE errors/counters
	*/
	typedef enum
	{
	#define _(sym,str) VXLAN_GPE_ENCAP_ERROR_##sym,
	foreach_vxlan_gpe_encap_error
	#undef _
	VXLAN_GPE_ENCAP_N_ERROR,
	} vxlan_gpe_encap_error_t;

	/**
	* @brief Struct for tracing VXLAN GPE encapsulated packets
	*/
	typedef struct
	{
	u32 tunnel_index;
	} vxlan_gpe_encap_trace_t;

	/**
	* @brief Trace of packets encapsulated in VXLAN GPE
	*
	* @param *s
	* @param *args
	*
	* @return *s
	*
	*/
	u8 *
	format_vxlan_gpe_encap_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_encap_trace_t t = va_arg (args, vxlan_gpe_encap_trace_t *);

	s = format (s, "VXLAN-GPE-ENCAP: tunnel %d", t->tunnel_index);
	return s;
	}

	/**
	* @brief Instantiates UDP + VXLAN-GPE header then set next node to IP4\|6 lookup
	*
	* @param *ngm
	* @param *b0
	* @param *t0 contains rewrite header
	* @param *next0 relative index of next dispatch function (next node)
	* @param is_v4 Is this IPv4? (or IPv6)
	*
	*/
	always_inline void
	vxlan_gpe_encap_one_inline (vxlan_gpe_main_t * ngm, vlib_buffer_t * b0,
	vxlan_gpe_tunnel_t * t0, u32 * next0, u8 is_v4)
	{
	ASSERT (sizeof (ip4_vxlan_gpe_header_t) == 36);
	ASSERT (sizeof (ip6_vxlan_gpe_header_t) == 56);

	ip_udp_encap_one (ngm->vlib_main, b0, t0->rewrite, t0->rewrite_size, is_v4);
	next0[0] = t0->encap_next_node;
	}

	/**
	* @brief Instantiates UDP + VXLAN-GPE header then set next node to IP4\|6 lookup for two packets
	*
	* @param *ngm
	* @param *b0 Packet0
	* @param *b1 Packet1
	* @param *t0 contains rewrite header for Packet0
	* @param *t1 contains rewrite header for Packet1
	* @param *next0 relative index of next dispatch function (next node) for Packet0
	* @param *next1 relative index of next dispatch function (next node) for Packet1
	* @param is_v4 Is this IPv4? (or IPv6)
	*
	*/
	always_inline void
	vxlan_gpe_encap_two_inline (vxlan_gpe_main_t * ngm, vlib_buffer_t * b0,
	vlib_buffer_t * b1, vxlan_gpe_tunnel_t * t0,
	vxlan_gpe_tunnel_t * t1, u32 * next0,
	u32 * next1, u8 is_v4)
	{
	ASSERT (sizeof (ip4_vxlan_gpe_header_t) == 36);
	ASSERT (sizeof (ip6_vxlan_gpe_header_t) == 56);

	ip_udp_encap_one (ngm->vlib_main, b0, t0->rewrite, t0->rewrite_size, is_v4);
	ip_udp_encap_one (ngm->vlib_main, b1, t1->rewrite, t1->rewrite_size, is_v4);
	next0[0] = next1[0] = t0->encap_next_node;
	}

	/**
	* @brief Common processing for IPv4 and IPv6 VXLAN GPE encap dispatch functions
	*
	* It is worth noting that other than trivial UDP forwarding (transit), VXLAN GPE
	* tunnels are "establish local". This means that we don't have a TX interface as yet
	* as we need to look up where the outer-header dest is. By setting the TX index in the
	* buffer metadata to the encap FIB, we can do a lookup to get the adjacency and real TX.
	*
	* vnet_buffer(b0)->sw_if_index[VLIB_TX] = t0->encap_fib_index;
	*
	* @node vxlan-gpe-input
	* @param *vm
	* @param *node
	* @param *from_frame
	*
	* @return from_frame->n_vectors
	*
	*/
	static uword
	vxlan_gpe_encap (vlib_main_t * vm,
	vlib_node_runtime_t * node, vlib_frame_t * from_frame)
	{
	u32 n_left_from, next_index, from, to_next;
	vxlan_gpe_main_t *ngm = &vxlan_gpe_main;
	vnet_main_t *vnm = ngm->vnet_main;
	vnet_interface_main_t *im = &vnm->interface_main;
	u32 pkts_encapsulated = 0;
	u32 thread_index = vm->thread_index;
	u32 stats_sw_if_index, stats_n_packets, stats_n_bytes;
	vlib_buffer_t bufs[VLIB_FRAME_SIZE], *b = bufs;

	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;
	vlib_get_buffers (vm, from, bufs, n_left_from);

	while (n_left_from > 0)
	{
	u32 n_left_to_next;
	u32 sw_if_index0 = ~0, sw_if_index1 = ~0, len0, len1;
	vnet_hw_interface_t hi0, hi1;
	vxlan_gpe_tunnel_t t0 = NULL, t1 = NULL;
	u8 is_ip4_0 = 0, is_ip4_1 = 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)
	{
	u32 bi0, bi1;
	u32 next0, next1;

	next0 = next1 = VXLAN_GPE_ENCAP_NEXT_IP4_LOOKUP;

	/* Prefetch next iteration. */
	{
	vlib_prefetch_buffer_header (b[2], LOAD);
	vlib_prefetch_buffer_header (b[3], LOAD);

	CLIB_PREFETCH (b[2]->data - CLIB_CACHE_LINE_BYTES,
	2 * CLIB_CACHE_LINE_BYTES, LOAD);
	CLIB_PREFETCH (b[3]->data - CLIB_CACHE_LINE_BYTES,
	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;

	/* get the flag "is_ip4" */
	if (sw_if_index0 != vnet_buffer (b[0])->sw_if_index[VLIB_TX])
	{
	sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_TX];
	hi0 =
	vnet_get_sup_hw_interface (vnm,
	vnet_buffer (b[0])->sw_if_index
	[VLIB_TX]);
	t0 = pool_elt_at_index (ngm->tunnels, hi0->dev_instance);
	is_ip4_0 = (t0->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
	}

	/* get the flag "is_ip4" */
	if (sw_if_index1 != vnet_buffer (b[1])->sw_if_index[VLIB_TX])
	{
	if (sw_if_index0 == vnet_buffer (b[1])->sw_if_index[VLIB_TX])
	{
	sw_if_index1 = sw_if_index0;
	hi1 = hi0;
	t1 = t0;
	is_ip4_1 = is_ip4_0;
	}
	else
	{
	sw_if_index1 = vnet_buffer (b[1])->sw_if_index[VLIB_TX];
	hi1 =
	vnet_get_sup_hw_interface (vnm,
	vnet_buffer (b[1])->sw_if_index
	[VLIB_TX]);
	t1 = pool_elt_at_index (ngm->tunnels, hi1->dev_instance);
	is_ip4_1 = (t1->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
	}
	}

	if (PREDICT_TRUE (is_ip4_0 == is_ip4_1))
	{
	vxlan_gpe_encap_two_inline (ngm, b[0], b[1], t0, t1, &next0,
	&next1, is_ip4_0);
	}
	else
	{
	vxlan_gpe_encap_one_inline (ngm, b[0], t0, &next0, is_ip4_0);
	vxlan_gpe_encap_one_inline (ngm, b[1], t1, &next1, is_ip4_1);
	}

	/* Reset to look up tunnel partner in the configured FIB */
	vnet_buffer (b[0])->sw_if_index[VLIB_TX] = t0->encap_fib_index;
	vnet_buffer (b[1])->sw_if_index[VLIB_TX] = t1->encap_fib_index;
	vnet_buffer (b[0])->sw_if_index[VLIB_RX] = sw_if_index0;
	vnet_buffer (b[1])->sw_if_index[VLIB_RX] = sw_if_index1;
	pkts_encapsulated += 2;

	len0 = vlib_buffer_length_in_chain (vm, b[0]);
	len1 = vlib_buffer_length_in_chain (vm, b[1]);
	stats_n_packets += 2;
	stats_n_bytes += len0 + len1;

	/* Batch stats increment on the same vxlan tunnel so counter is not
	incremented per packet. Note stats are still incremented for deleted
	and admin-down tunnel where packets are dropped. It is not worthwhile
	to check for this rare case and affect normal path performance. */
	if (PREDICT_FALSE ((sw_if_index0 != stats_sw_if_index)
	\|\| (sw_if_index1 != stats_sw_if_index)))
	{
	stats_n_packets -= 2;
	stats_n_bytes -= len0 + len1;
	if (sw_if_index0 == sw_if_index1)
	{
	if (stats_n_packets)
	vlib_increment_combined_counter
	(im->combined_sw_if_counters +
	VNET_INTERFACE_COUNTER_TX, thread_index,
	stats_sw_if_index, stats_n_packets, stats_n_bytes);
	stats_sw_if_index = sw_if_index0;
	stats_n_packets = 2;
	stats_n_bytes = len0 + len1;
	}
	else
	{
	vlib_increment_combined_counter (im->combined_sw_if_counters
	+
	VNET_INTERFACE_COUNTER_TX,
	thread_index, sw_if_index0,
	1, len0);
	vlib_increment_combined_counter (im->combined_sw_if_counters
	+
	VNET_INTERFACE_COUNTER_TX,
	thread_index, sw_if_index1,
	1, len1);
	}
	}

	if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
	{
	vxlan_gpe_encap_trace_t *tr =
	vlib_add_trace (vm, node, b[0], sizeof (*tr));
	tr->tunnel_index = t0 - ngm->tunnels;
	}

	if (PREDICT_FALSE (b[1]->flags & VLIB_BUFFER_IS_TRACED))
	{
	vxlan_gpe_encap_trace_t *tr = vlib_add_trace (vm, node, b[1],
	sizeof (*tr));
	tr->tunnel_index = t1 - ngm->tunnels;
	}
	b += 2;

	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;
	u32 next0 = VXLAN_GPE_ENCAP_NEXT_IP4_LOOKUP;

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

	/* get the flag "is_ip4" */
	if (sw_if_index0 != vnet_buffer (b[0])->sw_if_index[VLIB_TX])
	{
	sw_if_index0 = vnet_buffer (b[0])->sw_if_index[VLIB_TX];
	hi0 =
	vnet_get_sup_hw_interface (vnm,
	vnet_buffer (b[0])->sw_if_index
	[VLIB_TX]);

	t0 = pool_elt_at_index (ngm->tunnels, hi0->dev_instance);

	is_ip4_0 = (t0->flags & VXLAN_GPE_TUNNEL_IS_IPV4);
	}

	vxlan_gpe_encap_one_inline (ngm, b[0], t0, &next0, is_ip4_0);

	/* Reset to look up tunnel partner in the configured FIB */
	vnet_buffer (b[0])->sw_if_index[VLIB_TX] = t0->encap_fib_index;
	vnet_buffer (b[0])->sw_if_index[VLIB_RX] = sw_if_index0;
	pkts_encapsulated++;

	len0 = vlib_buffer_length_in_chain (vm, b[0]);
	stats_n_packets += 1;
	stats_n_bytes += len0;

	/* Batch stats increment on the same vxlan tunnel so counter is not
	* incremented per packet. Note stats are still incremented for deleted
	* and admin-down tunnel where packets are dropped. It is not worthwhile
	* to check for this rare case and affect normal path performance. */
	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_TX,
	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;
	}
	if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
	{
	vxlan_gpe_encap_trace_t *tr = vlib_add_trace (vm, node, b[0],
	sizeof (*tr));
	tr->tunnel_index = t0 - ngm->tunnels;
	}
	b += 1;

	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, node->node_index,
	VXLAN_GPE_ENCAP_ERROR_ENCAPSULATED,
	pkts_encapsulated);
	/* Increment any remaining batch stats */
	if (stats_n_packets)
	{
	vlib_increment_combined_counter (im->combined_sw_if_counters +
	VNET_INTERFACE_COUNTER_TX,
	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;
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (vxlan_gpe_encap_node) = {
	.function = vxlan_gpe_encap,
	.name = "vxlan-gpe-encap",
	.vector_size = sizeof (u32),
	.format_trace = format_vxlan_gpe_encap_trace,
	.type = VLIB_NODE_TYPE_INTERNAL,

	.n_errors = ARRAY_LEN(vxlan_gpe_encap_error_strings),
	.error_strings = vxlan_gpe_encap_error_strings,

	.n_next_nodes = VXLAN_GPE_ENCAP_N_NEXT,

	.next_nodes = {
	[VXLAN_GPE_ENCAP_NEXT_IP4_LOOKUP] = "ip4-lookup",
	[VXLAN_GPE_ENCAP_NEXT_IP6_LOOKUP] = "ip6-lookup",
	[VXLAN_GPE_ENCAP_NEXT_DROP] = "error-drop",
	},
	};
	/* INDENT-ON */


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