src/vnet/ip/ip4_forward.h - 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.
  */
 /*
  * ip/ip4_forward.h: IP v4 forwarding
  *
  * Copyright (c) 2008 Eliot Dresselhaus
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sublicense, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * The above copyright notice and this permission notice shall be
  * included in all copies or substantial portions of the Software.
  *
  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */

 #ifndef __included_ip4_forward_h__
 #define __included_ip4_forward_h__

 #include <vppinfra/cache.h>
 #include <vnet/fib/ip4_fib.h>
 #include <vnet/dpo/load_balance_map.h>

 /**
  * @file
  * @brief IPv4 Forwarding.
  *
  * This file contains the source code for IPv4 forwarding.
  */

 always_inline uword
 ip4_lookup_inline (vlib_main_t * vm,
 		   vlib_node_runtime_t * node,
 		   vlib_frame_t * frame,
 		   int lookup_for_responses_to_locally_received_packets)
 {
   ip4_main_t *im = &ip4_main;
   vlib_combined_counter_main_t *cm = &load_balance_main.lbm_to_counters;
   u32 n_left_from, n_left_to_next, *from, *to_next;
   ip_lookup_next_t next;
   u32 thread_index = vm->thread_index;

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

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

 #if (CLIB_N_PREFETCHES >= 8)
       while (n_left_from >= 8 && n_left_to_next >= 4)
 	{
 	  vlib_buffer_t *p0, *p1, *p2, *p3;
 	  ip4_header_t *ip0, *ip1, *ip2, *ip3;
 	  ip_lookup_next_t next0, next1, next2, next3;
 	  const load_balance_t *lb0, *lb1, *lb2, *lb3;
 	  ip4_fib_mtrie_t *mtrie0, *mtrie1, *mtrie2, *mtrie3;
 	  ip4_fib_mtrie_leaf_t leaf0, leaf1, leaf2, leaf3;
 	  ip4_address_t *dst_addr0, *dst_addr1, *dst_addr2, *dst_addr3;
 	  u32 pi0, pi1, pi2, pi3, lb_index0, lb_index1, lb_index2, lb_index3;
 	  flow_hash_config_t flow_hash_config0, flow_hash_config1;
 	  flow_hash_config_t flow_hash_config2, flow_hash_config3;
 	  u32 hash_c0, hash_c1, hash_c2, hash_c3;
 	  const dpo_id_t *dpo0, *dpo1, *dpo2, *dpo3;

 	  /* Prefetch next iteration. */
 	  {
 	    vlib_buffer_t *p4, *p5, *p6, *p7;

 	    p4 = vlib_get_buffer (vm, from[4]);
 	    p5 = vlib_get_buffer (vm, from[5]);
 	    p6 = vlib_get_buffer (vm, from[6]);
 	    p7 = vlib_get_buffer (vm, from[7]);

 	    vlib_prefetch_buffer_header (p4, LOAD);
 	    vlib_prefetch_buffer_header (p5, LOAD);
 	    vlib_prefetch_buffer_header (p6, LOAD);
 	    vlib_prefetch_buffer_header (p7, LOAD);

 	    CLIB_PREFETCH (p4->data, sizeof (ip0[0]), LOAD);
 	    CLIB_PREFETCH (p5->data, sizeof (ip0[0]), LOAD);
 	    CLIB_PREFETCH (p6->data, sizeof (ip0[0]), LOAD);
 	    CLIB_PREFETCH (p7->data, sizeof (ip0[0]), LOAD);
 	  }

 	  pi0 = to_next[0] = from[0];
 	  pi1 = to_next[1] = from[1];
 	  pi2 = to_next[2] = from[2];
 	  pi3 = to_next[3] = from[3];

 	  from += 4;
 	  to_next += 4;
 	  n_left_to_next -= 4;
 	  n_left_from -= 4;

 	  p0 = vlib_get_buffer (vm, pi0);
 	  p1 = vlib_get_buffer (vm, pi1);
 	  p2 = vlib_get_buffer (vm, pi2);
 	  p3 = vlib_get_buffer (vm, pi3);

 	  ip0 = vlib_buffer_get_current (p0);
 	  ip1 = vlib_buffer_get_current (p1);
 	  ip2 = vlib_buffer_get_current (p2);
 	  ip3 = vlib_buffer_get_current (p3);

 	  dst_addr0 = &ip0->dst_address;
 	  dst_addr1 = &ip1->dst_address;
 	  dst_addr2 = &ip2->dst_address;
 	  dst_addr3 = &ip3->dst_address;

 	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p0);
 	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p1);
 	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p2);
 	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p3);

 	  if (!lookup_for_responses_to_locally_received_packets)
 	    {
 	      mtrie0 = &ip4_fib_get (vnet_buffer (p0)->ip.fib_index)->mtrie;
 	      mtrie1 = &ip4_fib_get (vnet_buffer (p1)->ip.fib_index)->mtrie;
 	      mtrie2 = &ip4_fib_get (vnet_buffer (p2)->ip.fib_index)->mtrie;
 	      mtrie3 = &ip4_fib_get (vnet_buffer (p3)->ip.fib_index)->mtrie;

 	      leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, dst_addr0);
 	      leaf1 = ip4_fib_mtrie_lookup_step_one (mtrie1, dst_addr1);
 	      leaf2 = ip4_fib_mtrie_lookup_step_one (mtrie2, dst_addr2);
 	      leaf3 = ip4_fib_mtrie_lookup_step_one (mtrie3, dst_addr3);
 	    }

 	  if (!lookup_for_responses_to_locally_received_packets)
 	    {
 	      leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 2);
 	      leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, dst_addr1, 2);
 	      leaf2 = ip4_fib_mtrie_lookup_step (mtrie2, leaf2, dst_addr2, 2);
 	      leaf3 = ip4_fib_mtrie_lookup_step (mtrie3, leaf3, dst_addr3, 2);
 	    }

 	  if (!lookup_for_responses_to_locally_received_packets)
 	    {
 	      leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 3);
 	      leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, dst_addr1, 3);
 	      leaf2 = ip4_fib_mtrie_lookup_step (mtrie2, leaf2, dst_addr2, 3);
 	      leaf3 = ip4_fib_mtrie_lookup_step (mtrie3, leaf3, dst_addr3, 3);
 	    }

 	  if (lookup_for_responses_to_locally_received_packets)
 	    {
 	      lb_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_RX];
 	      lb_index1 = vnet_buffer (p1)->ip.adj_index[VLIB_RX];
 	      lb_index2 = vnet_buffer (p2)->ip.adj_index[VLIB_RX];
 	      lb_index3 = vnet_buffer (p3)->ip.adj_index[VLIB_RX];
 	    }
 	  else
 	    {
 	      lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
 	      lb_index1 = ip4_fib_mtrie_leaf_get_adj_index (leaf1);
 	      lb_index2 = ip4_fib_mtrie_leaf_get_adj_index (leaf2);
 	      lb_index3 = ip4_fib_mtrie_leaf_get_adj_index (leaf3);
 	    }

 	  ASSERT (lb_index0 && lb_index1 && lb_index2 && lb_index3);
 	  lb0 = load_balance_get (lb_index0);
 	  lb1 = load_balance_get (lb_index1);
 	  lb2 = load_balance_get (lb_index2);
 	  lb3 = load_balance_get (lb_index3);

 	  ASSERT (lb0->lb_n_buckets > 0);
 	  ASSERT (is_pow2 (lb0->lb_n_buckets));
 	  ASSERT (lb1->lb_n_buckets > 0);
 	  ASSERT (is_pow2 (lb1->lb_n_buckets));
 	  ASSERT (lb2->lb_n_buckets > 0);
 	  ASSERT (is_pow2 (lb2->lb_n_buckets));
 	  ASSERT (lb3->lb_n_buckets > 0);
 	  ASSERT (is_pow2 (lb3->lb_n_buckets));

 	  /* Use flow hash to compute multipath adjacency. */
 	  hash_c0 = vnet_buffer (p0)->ip.flow_hash = 0;
 	  hash_c1 = vnet_buffer (p1)->ip.flow_hash = 0;
 	  hash_c2 = vnet_buffer (p2)->ip.flow_hash = 0;
 	  hash_c3 = vnet_buffer (p3)->ip.flow_hash = 0;
 	  if (PREDICT_FALSE (lb0->lb_n_buckets > 1))
 	    {
 	      flow_hash_config0 = lb0->lb_hash_config;
 	      hash_c0 = vnet_buffer (p0)->ip.flow_hash =
 		ip4_compute_flow_hash (ip0, flow_hash_config0);
 	      dpo0 =
 		load_balance_get_fwd_bucket (lb0,
 					     (hash_c0 &
 					      (lb0->lb_n_buckets_minus_1)));
 	    }
 	  else
 	    {
 	      dpo0 = load_balance_get_bucket_i (lb0, 0);
 	    }
 	  if (PREDICT_FALSE (lb1->lb_n_buckets > 1))
 	    {
 	      flow_hash_config1 = lb1->lb_hash_config;
 	      hash_c1 = vnet_buffer (p1)->ip.flow_hash =
 		ip4_compute_flow_hash (ip1, flow_hash_config1);
 	      dpo1 =
 		load_balance_get_fwd_bucket (lb1,
 					     (hash_c1 &
 					      (lb1->lb_n_buckets_minus_1)));
 	    }
 	  else
 	    {
 	      dpo1 = load_balance_get_bucket_i (lb1, 0);
 	    }
 	  if (PREDICT_FALSE (lb2->lb_n_buckets > 1))
 	    {
 	      flow_hash_config2 = lb2->lb_hash_config;
 	      hash_c2 = vnet_buffer (p2)->ip.flow_hash =
 		ip4_compute_flow_hash (ip2, flow_hash_config2);
 	      dpo2 =
 		load_balance_get_fwd_bucket (lb2,
 					     (hash_c2 &
 					      (lb2->lb_n_buckets_minus_1)));
 	    }
 	  else
 	    {
 	      dpo2 = load_balance_get_bucket_i (lb2, 0);
 	    }
 	  if (PREDICT_FALSE (lb3->lb_n_buckets > 1))
 	    {
 	      flow_hash_config3 = lb3->lb_hash_config;
 	      hash_c3 = vnet_buffer (p3)->ip.flow_hash =
 		ip4_compute_flow_hash (ip3, flow_hash_config3);
 	      dpo3 =
 		load_balance_get_fwd_bucket (lb3,
 					     (hash_c3 &
 					      (lb3->lb_n_buckets_minus_1)));
 	    }
 	  else
 	    {
 	      dpo3 = load_balance_get_bucket_i (lb3, 0);
 	    }

 	  next0 = dpo0->dpoi_next_node;
 	  vnet_buffer (p0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
 	  next1 = dpo1->dpoi_next_node;
 	  vnet_buffer (p1)->ip.adj_index[VLIB_TX] = dpo1->dpoi_index;
 	  next2 = dpo2->dpoi_next_node;
 	  vnet_buffer (p2)->ip.adj_index[VLIB_TX] = dpo2->dpoi_index;
 	  next3 = dpo3->dpoi_next_node;
 	  vnet_buffer (p3)->ip.adj_index[VLIB_TX] = dpo3->dpoi_index;

 	  vlib_increment_combined_counter
 	    (cm, thread_index, lb_index0, 1,
 	     vlib_buffer_length_in_chain (vm, p0));
 	  vlib_increment_combined_counter
 	    (cm, thread_index, lb_index1, 1,
 	     vlib_buffer_length_in_chain (vm, p1));
 	  vlib_increment_combined_counter
 	    (cm, thread_index, lb_index2, 1,
 	     vlib_buffer_length_in_chain (vm, p2));
 	  vlib_increment_combined_counter
 	    (cm, thread_index, lb_index3, 1,
 	     vlib_buffer_length_in_chain (vm, p3));

 	  vlib_validate_buffer_enqueue_x4 (vm, node, next,
 					   to_next, n_left_to_next,
 					   pi0, pi1, pi2, pi3,
 					   next0, next1, next2, next3);
 	}
 #elif (CLIB_N_PREFETCHES >= 4)
       while (n_left_from >= 4 && n_left_to_next >= 2)
 	{
 	  vlib_buffer_t *p0, *p1;
 	  ip4_header_t *ip0, *ip1;
 	  ip_lookup_next_t next0, next1;
 	  const load_balance_t *lb0, *lb1;
 	  ip4_fib_mtrie_t *mtrie0, *mtrie1;
 	  ip4_fib_mtrie_leaf_t leaf0, leaf1;
 	  ip4_address_t *dst_addr0, *dst_addr1;
 	  u32 pi0, pi1, lb_index0, lb_index1;
 	  flow_hash_config_t flow_hash_config0, flow_hash_config1;
 	  u32 hash_c0, hash_c1;
 	  const dpo_id_t *dpo0, *dpo1;

 	  /* 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, sizeof (ip0[0]), LOAD);
 	    CLIB_PREFETCH (p3->data, sizeof (ip0[0]), LOAD);
 	  }

 	  pi0 = to_next[0] = from[0];
 	  pi1 = to_next[1] = from[1];

 	  from += 2;
 	  to_next += 2;
 	  n_left_to_next -= 2;
 	  n_left_from -= 2;

 	  p0 = vlib_get_buffer (vm, pi0);
 	  p1 = vlib_get_buffer (vm, pi1);

 	  ip0 = vlib_buffer_get_current (p0);
 	  ip1 = vlib_buffer_get_current (p1);

 	  dst_addr0 = &ip0->dst_address;
 	  dst_addr1 = &ip1->dst_address;

 	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p0);
 	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p1);

 	  if (!lookup_for_responses_to_locally_received_packets)
 	    {
 	      mtrie0 = &ip4_fib_get (vnet_buffer (p0)->ip.fib_index)->mtrie;
 	      mtrie1 = &ip4_fib_get (vnet_buffer (p1)->ip.fib_index)->mtrie;

 	      leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, dst_addr0);
 	      leaf1 = ip4_fib_mtrie_lookup_step_one (mtrie1, dst_addr1);
 	    }

 	  if (!lookup_for_responses_to_locally_received_packets)
 	    {
 	      leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 2);
 	      leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, dst_addr1, 2);
 	    }

 	  if (!lookup_for_responses_to_locally_received_packets)
 	    {
 	      leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 3);
 	      leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, dst_addr1, 3);
 	    }

 	  if (lookup_for_responses_to_locally_received_packets)
 	    {
 	      lb_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_RX];
 	      lb_index1 = vnet_buffer (p1)->ip.adj_index[VLIB_RX];
 	    }
 	  else
 	    {
 	      lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
 	      lb_index1 = ip4_fib_mtrie_leaf_get_adj_index (leaf1);
 	    }

 	  ASSERT (lb_index0 && lb_index1);
 	  lb0 = load_balance_get (lb_index0);
 	  lb1 = load_balance_get (lb_index1);

 	  ASSERT (lb0->lb_n_buckets > 0);
 	  ASSERT (is_pow2 (lb0->lb_n_buckets));
 	  ASSERT (lb1->lb_n_buckets > 0);
 	  ASSERT (is_pow2 (lb1->lb_n_buckets));

 	  /* Use flow hash to compute multipath adjacency. */
 	  hash_c0 = vnet_buffer (p0)->ip.flow_hash = 0;
 	  hash_c1 = vnet_buffer (p1)->ip.flow_hash = 0;
 	  if (PREDICT_FALSE (lb0->lb_n_buckets > 1))
 	    {
 	      flow_hash_config0 = lb0->lb_hash_config;
 	      hash_c0 = vnet_buffer (p0)->ip.flow_hash =
 		ip4_compute_flow_hash (ip0, flow_hash_config0);
 	      dpo0 =
 		load_balance_get_fwd_bucket (lb0,
 					     (hash_c0 &
 					      (lb0->lb_n_buckets_minus_1)));
 	    }
 	  else
 	    {
 	      dpo0 = load_balance_get_bucket_i (lb0, 0);
 	    }
 	  if (PREDICT_FALSE (lb1->lb_n_buckets > 1))
 	    {
 	      flow_hash_config1 = lb1->lb_hash_config;
 	      hash_c1 = vnet_buffer (p1)->ip.flow_hash =
 		ip4_compute_flow_hash (ip1, flow_hash_config1);
 	      dpo1 =
 		load_balance_get_fwd_bucket (lb1,
 					     (hash_c1 &
 					      (lb1->lb_n_buckets_minus_1)));
 	    }
 	  else
 	    {
 	      dpo1 = load_balance_get_bucket_i (lb1, 0);
 	    }

 	  next0 = dpo0->dpoi_next_node;
 	  vnet_buffer (p0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
 	  next1 = dpo1->dpoi_next_node;
 	  vnet_buffer (p1)->ip.adj_index[VLIB_TX] = dpo1->dpoi_index;

 	  vlib_increment_combined_counter
 	    (cm, thread_index, lb_index0, 1,
 	     vlib_buffer_length_in_chain (vm, p0));
 	  vlib_increment_combined_counter
 	    (cm, thread_index, lb_index1, 1,
 	     vlib_buffer_length_in_chain (vm, p1));

 	  vlib_validate_buffer_enqueue_x2 (vm, node, next,
 					   to_next, n_left_to_next,
 					   pi0, pi1, next0, next1);
 	}
 #endif
       while (n_left_from > 0 && n_left_to_next > 0)
 	{
 	  vlib_buffer_t *p0;
 	  ip4_header_t *ip0;
 	  ip_lookup_next_t next0;
 	  const load_balance_t *lb0;
 	  ip4_fib_mtrie_t *mtrie0;
 	  ip4_fib_mtrie_leaf_t leaf0;
 	  ip4_address_t *dst_addr0;
 	  u32 pi0, lbi0;
 	  flow_hash_config_t flow_hash_config0;
 	  const dpo_id_t *dpo0;
 	  u32 hash_c0;

 	  pi0 = from[0];
 	  to_next[0] = pi0;

 	  p0 = vlib_get_buffer (vm, pi0);
 	  ip0 = vlib_buffer_get_current (p0);
 	  dst_addr0 = &ip0->dst_address;
 	  ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p0);

 	  if (!lookup_for_responses_to_locally_received_packets)
 	    {
 	      mtrie0 = &ip4_fib_get (vnet_buffer (p0)->ip.fib_index)->mtrie;
 	      leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, dst_addr0);
 	    }

 	  if (!lookup_for_responses_to_locally_received_packets)
 	    leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 2);

 	  if (!lookup_for_responses_to_locally_received_packets)
 	    leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 3);

 	  if (lookup_for_responses_to_locally_received_packets)
 	    lbi0 = vnet_buffer (p0)->ip.adj_index[VLIB_RX];
 	  else
 	    {
 	      /* Handle default route. */
 	      lbi0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
 	    }

 	  ASSERT (lbi0);
 	  lb0 = load_balance_get (lbi0);

 	  ASSERT (lb0->lb_n_buckets > 0);
 	  ASSERT (is_pow2 (lb0->lb_n_buckets));

 	  /* Use flow hash to compute multipath adjacency. */
 	  hash_c0 = vnet_buffer (p0)->ip.flow_hash = 0;
 	  if (PREDICT_FALSE (lb0->lb_n_buckets > 1))
 	    {
 	      flow_hash_config0 = lb0->lb_hash_config;

 	      hash_c0 = vnet_buffer (p0)->ip.flow_hash =
 		ip4_compute_flow_hash (ip0, flow_hash_config0);
 	      dpo0 =
 		load_balance_get_fwd_bucket (lb0,
 					     (hash_c0 &
 					      (lb0->lb_n_buckets_minus_1)));
 	    }
 	  else
 	    {
 	      dpo0 = load_balance_get_bucket_i (lb0, 0);
 	    }

 	  next0 = dpo0->dpoi_next_node;
 	  vnet_buffer (p0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;

 	  vlib_increment_combined_counter (cm, thread_index, lbi0, 1,
 					   vlib_buffer_length_in_chain (vm,
 									p0));

 	  from += 1;
 	  to_next += 1;
 	  n_left_to_next -= 1;
 	  n_left_from -= 1;

 	  if (PREDICT_FALSE (next0 != next))
 	    {
 	      n_left_to_next += 1;
 	      vlib_put_next_frame (vm, node, next, n_left_to_next);
 	      next = next0;
 	      vlib_get_next_frame (vm, node, next, to_next, n_left_to_next);
 	      to_next[0] = pi0;
 	      to_next += 1;
 	      n_left_to_next -= 1;
 	    }
 	}

       vlib_put_next_frame (vm, node, next, n_left_to_next);
     }

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

   return frame->n_vectors;
 }

 #endif /* __included_ip4_forward_h__ */

 /*
  * 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.
	*/
	/*
	* ip/ip4_forward.h: IP v4 forwarding
	*
	* Copyright (c) 2008 Eliot Dresselhaus
	*
	* Permission is hereby granted, free of charge, to any person obtaining
	* a copy of this software and associated documentation files (the
	* "Software"), to deal in the Software without restriction, including
	* without limitation the rights to use, copy, modify, merge, publish,
	* distribute, sublicense, and/or sell copies of the Software, and to
	* permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* The above copyright notice and this permission notice shall be
	* included in all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
	* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
	* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
	* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*/

	#ifndef __included_ip4_forward_h__
	#define __included_ip4_forward_h__

	#include <vppinfra/cache.h>
	#include <vnet/fib/ip4_fib.h>
	#include <vnet/dpo/load_balance_map.h>

	/**
	* @file
	* @brief IPv4 Forwarding.
	*
	* This file contains the source code for IPv4 forwarding.
	*/

	always_inline uword
	ip4_lookup_inline (vlib_main_t * vm,
	vlib_node_runtime_t * node,
	vlib_frame_t * frame,
	int lookup_for_responses_to_locally_received_packets)
	{
	ip4_main_t *im = &ip4_main;
	vlib_combined_counter_main_t *cm = &load_balance_main.lbm_to_counters;
	u32 n_left_from, n_left_to_next, from, to_next;
	ip_lookup_next_t next;
	u32 thread_index = vm->thread_index;

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

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

	#if (CLIB_N_PREFETCHES >= 8)
	while (n_left_from >= 8 && n_left_to_next >= 4)
	{
	vlib_buffer_t p0, p1, p2, p3;
	ip4_header_t ip0, ip1, ip2, ip3;
	ip_lookup_next_t next0, next1, next2, next3;
	const load_balance_t lb0, lb1, lb2, lb3;
	ip4_fib_mtrie_t mtrie0, mtrie1, mtrie2, mtrie3;
	ip4_fib_mtrie_leaf_t leaf0, leaf1, leaf2, leaf3;
	ip4_address_t dst_addr0, dst_addr1, dst_addr2, dst_addr3;
	u32 pi0, pi1, pi2, pi3, lb_index0, lb_index1, lb_index2, lb_index3;
	flow_hash_config_t flow_hash_config0, flow_hash_config1;
	flow_hash_config_t flow_hash_config2, flow_hash_config3;
	u32 hash_c0, hash_c1, hash_c2, hash_c3;
	const dpo_id_t dpo0, dpo1, dpo2, dpo3;

	/* Prefetch next iteration. */
	{
	vlib_buffer_t p4, p5, p6, p7;

	p4 = vlib_get_buffer (vm, from[4]);
	p5 = vlib_get_buffer (vm, from[5]);
	p6 = vlib_get_buffer (vm, from[6]);
	p7 = vlib_get_buffer (vm, from[7]);

	vlib_prefetch_buffer_header (p4, LOAD);
	vlib_prefetch_buffer_header (p5, LOAD);
	vlib_prefetch_buffer_header (p6, LOAD);
	vlib_prefetch_buffer_header (p7, LOAD);

	CLIB_PREFETCH (p4->data, sizeof (ip0[0]), LOAD);
	CLIB_PREFETCH (p5->data, sizeof (ip0[0]), LOAD);
	CLIB_PREFETCH (p6->data, sizeof (ip0[0]), LOAD);
	CLIB_PREFETCH (p7->data, sizeof (ip0[0]), LOAD);
	}

	pi0 = to_next[0] = from[0];
	pi1 = to_next[1] = from[1];
	pi2 = to_next[2] = from[2];
	pi3 = to_next[3] = from[3];

	from += 4;
	to_next += 4;
	n_left_to_next -= 4;
	n_left_from -= 4;

	p0 = vlib_get_buffer (vm, pi0);
	p1 = vlib_get_buffer (vm, pi1);
	p2 = vlib_get_buffer (vm, pi2);
	p3 = vlib_get_buffer (vm, pi3);

	ip0 = vlib_buffer_get_current (p0);
	ip1 = vlib_buffer_get_current (p1);
	ip2 = vlib_buffer_get_current (p2);
	ip3 = vlib_buffer_get_current (p3);

	dst_addr0 = &ip0->dst_address;
	dst_addr1 = &ip1->dst_address;
	dst_addr2 = &ip2->dst_address;
	dst_addr3 = &ip3->dst_address;

	ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p0);
	ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p1);
	ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p2);
	ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p3);

	if (!lookup_for_responses_to_locally_received_packets)
	{
	mtrie0 = &ip4_fib_get (vnet_buffer (p0)->ip.fib_index)->mtrie;
	mtrie1 = &ip4_fib_get (vnet_buffer (p1)->ip.fib_index)->mtrie;
	mtrie2 = &ip4_fib_get (vnet_buffer (p2)->ip.fib_index)->mtrie;
	mtrie3 = &ip4_fib_get (vnet_buffer (p3)->ip.fib_index)->mtrie;

	leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, dst_addr0);
	leaf1 = ip4_fib_mtrie_lookup_step_one (mtrie1, dst_addr1);
	leaf2 = ip4_fib_mtrie_lookup_step_one (mtrie2, dst_addr2);
	leaf3 = ip4_fib_mtrie_lookup_step_one (mtrie3, dst_addr3);
	}

	if (!lookup_for_responses_to_locally_received_packets)
	{
	leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 2);
	leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, dst_addr1, 2);
	leaf2 = ip4_fib_mtrie_lookup_step (mtrie2, leaf2, dst_addr2, 2);
	leaf3 = ip4_fib_mtrie_lookup_step (mtrie3, leaf3, dst_addr3, 2);
	}

	if (!lookup_for_responses_to_locally_received_packets)
	{
	leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 3);
	leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, dst_addr1, 3);
	leaf2 = ip4_fib_mtrie_lookup_step (mtrie2, leaf2, dst_addr2, 3);
	leaf3 = ip4_fib_mtrie_lookup_step (mtrie3, leaf3, dst_addr3, 3);
	}

	if (lookup_for_responses_to_locally_received_packets)
	{
	lb_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_RX];
	lb_index1 = vnet_buffer (p1)->ip.adj_index[VLIB_RX];
	lb_index2 = vnet_buffer (p2)->ip.adj_index[VLIB_RX];
	lb_index3 = vnet_buffer (p3)->ip.adj_index[VLIB_RX];
	}
	else
	{
	lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
	lb_index1 = ip4_fib_mtrie_leaf_get_adj_index (leaf1);
	lb_index2 = ip4_fib_mtrie_leaf_get_adj_index (leaf2);
	lb_index3 = ip4_fib_mtrie_leaf_get_adj_index (leaf3);
	}

	ASSERT (lb_index0 && lb_index1 && lb_index2 && lb_index3);
	lb0 = load_balance_get (lb_index0);
	lb1 = load_balance_get (lb_index1);
	lb2 = load_balance_get (lb_index2);
	lb3 = load_balance_get (lb_index3);

	ASSERT (lb0->lb_n_buckets > 0);
	ASSERT (is_pow2 (lb0->lb_n_buckets));
	ASSERT (lb1->lb_n_buckets > 0);
	ASSERT (is_pow2 (lb1->lb_n_buckets));
	ASSERT (lb2->lb_n_buckets > 0);
	ASSERT (is_pow2 (lb2->lb_n_buckets));
	ASSERT (lb3->lb_n_buckets > 0);
	ASSERT (is_pow2 (lb3->lb_n_buckets));

	/* Use flow hash to compute multipath adjacency. */
	hash_c0 = vnet_buffer (p0)->ip.flow_hash = 0;
	hash_c1 = vnet_buffer (p1)->ip.flow_hash = 0;
	hash_c2 = vnet_buffer (p2)->ip.flow_hash = 0;
	hash_c3 = vnet_buffer (p3)->ip.flow_hash = 0;
	if (PREDICT_FALSE (lb0->lb_n_buckets > 1))
	{
	flow_hash_config0 = lb0->lb_hash_config;
	hash_c0 = vnet_buffer (p0)->ip.flow_hash =
	ip4_compute_flow_hash (ip0, flow_hash_config0);
	dpo0 =
	load_balance_get_fwd_bucket (lb0,
	(hash_c0 &
	(lb0->lb_n_buckets_minus_1)));
	}
	else
	{
	dpo0 = load_balance_get_bucket_i (lb0, 0);
	}
	if (PREDICT_FALSE (lb1->lb_n_buckets > 1))
	{
	flow_hash_config1 = lb1->lb_hash_config;
	hash_c1 = vnet_buffer (p1)->ip.flow_hash =
	ip4_compute_flow_hash (ip1, flow_hash_config1);
	dpo1 =
	load_balance_get_fwd_bucket (lb1,
	(hash_c1 &
	(lb1->lb_n_buckets_minus_1)));
	}
	else
	{
	dpo1 = load_balance_get_bucket_i (lb1, 0);
	}
	if (PREDICT_FALSE (lb2->lb_n_buckets > 1))
	{
	flow_hash_config2 = lb2->lb_hash_config;
	hash_c2 = vnet_buffer (p2)->ip.flow_hash =
	ip4_compute_flow_hash (ip2, flow_hash_config2);
	dpo2 =
	load_balance_get_fwd_bucket (lb2,
	(hash_c2 &
	(lb2->lb_n_buckets_minus_1)));
	}
	else
	{
	dpo2 = load_balance_get_bucket_i (lb2, 0);
	}
	if (PREDICT_FALSE (lb3->lb_n_buckets > 1))
	{
	flow_hash_config3 = lb3->lb_hash_config;
	hash_c3 = vnet_buffer (p3)->ip.flow_hash =
	ip4_compute_flow_hash (ip3, flow_hash_config3);
	dpo3 =
	load_balance_get_fwd_bucket (lb3,
	(hash_c3 &
	(lb3->lb_n_buckets_minus_1)));
	}
	else
	{
	dpo3 = load_balance_get_bucket_i (lb3, 0);
	}

	next0 = dpo0->dpoi_next_node;
	vnet_buffer (p0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
	next1 = dpo1->dpoi_next_node;
	vnet_buffer (p1)->ip.adj_index[VLIB_TX] = dpo1->dpoi_index;
	next2 = dpo2->dpoi_next_node;
	vnet_buffer (p2)->ip.adj_index[VLIB_TX] = dpo2->dpoi_index;
	next3 = dpo3->dpoi_next_node;
	vnet_buffer (p3)->ip.adj_index[VLIB_TX] = dpo3->dpoi_index;

	vlib_increment_combined_counter
	(cm, thread_index, lb_index0, 1,
	vlib_buffer_length_in_chain (vm, p0));
	vlib_increment_combined_counter
	(cm, thread_index, lb_index1, 1,
	vlib_buffer_length_in_chain (vm, p1));
	vlib_increment_combined_counter
	(cm, thread_index, lb_index2, 1,
	vlib_buffer_length_in_chain (vm, p2));
	vlib_increment_combined_counter
	(cm, thread_index, lb_index3, 1,
	vlib_buffer_length_in_chain (vm, p3));

	vlib_validate_buffer_enqueue_x4 (vm, node, next,
	to_next, n_left_to_next,
	pi0, pi1, pi2, pi3,
	next0, next1, next2, next3);
	}
	#elif (CLIB_N_PREFETCHES >= 4)
	while (n_left_from >= 4 && n_left_to_next >= 2)
	{
	vlib_buffer_t p0, p1;
	ip4_header_t ip0, ip1;
	ip_lookup_next_t next0, next1;
	const load_balance_t lb0, lb1;
	ip4_fib_mtrie_t mtrie0, mtrie1;
	ip4_fib_mtrie_leaf_t leaf0, leaf1;
	ip4_address_t dst_addr0, dst_addr1;
	u32 pi0, pi1, lb_index0, lb_index1;
	flow_hash_config_t flow_hash_config0, flow_hash_config1;
	u32 hash_c0, hash_c1;
	const dpo_id_t dpo0, dpo1;

	/* 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, sizeof (ip0[0]), LOAD);
	CLIB_PREFETCH (p3->data, sizeof (ip0[0]), LOAD);
	}

	pi0 = to_next[0] = from[0];
	pi1 = to_next[1] = from[1];

	from += 2;
	to_next += 2;
	n_left_to_next -= 2;
	n_left_from -= 2;

	p0 = vlib_get_buffer (vm, pi0);
	p1 = vlib_get_buffer (vm, pi1);

	ip0 = vlib_buffer_get_current (p0);
	ip1 = vlib_buffer_get_current (p1);

	dst_addr0 = &ip0->dst_address;
	dst_addr1 = &ip1->dst_address;

	ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p0);
	ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p1);

	if (!lookup_for_responses_to_locally_received_packets)
	{
	mtrie0 = &ip4_fib_get (vnet_buffer (p0)->ip.fib_index)->mtrie;
	mtrie1 = &ip4_fib_get (vnet_buffer (p1)->ip.fib_index)->mtrie;

	leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, dst_addr0);
	leaf1 = ip4_fib_mtrie_lookup_step_one (mtrie1, dst_addr1);
	}

	if (!lookup_for_responses_to_locally_received_packets)
	{
	leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 2);
	leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, dst_addr1, 2);
	}

	if (!lookup_for_responses_to_locally_received_packets)
	{
	leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 3);
	leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, dst_addr1, 3);
	}

	if (lookup_for_responses_to_locally_received_packets)
	{
	lb_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_RX];
	lb_index1 = vnet_buffer (p1)->ip.adj_index[VLIB_RX];
	}
	else
	{
	lb_index0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
	lb_index1 = ip4_fib_mtrie_leaf_get_adj_index (leaf1);
	}

	ASSERT (lb_index0 && lb_index1);
	lb0 = load_balance_get (lb_index0);
	lb1 = load_balance_get (lb_index1);

	ASSERT (lb0->lb_n_buckets > 0);
	ASSERT (is_pow2 (lb0->lb_n_buckets));
	ASSERT (lb1->lb_n_buckets > 0);
	ASSERT (is_pow2 (lb1->lb_n_buckets));

	/* Use flow hash to compute multipath adjacency. */
	hash_c0 = vnet_buffer (p0)->ip.flow_hash = 0;
	hash_c1 = vnet_buffer (p1)->ip.flow_hash = 0;
	if (PREDICT_FALSE (lb0->lb_n_buckets > 1))
	{
	flow_hash_config0 = lb0->lb_hash_config;
	hash_c0 = vnet_buffer (p0)->ip.flow_hash =
	ip4_compute_flow_hash (ip0, flow_hash_config0);
	dpo0 =
	load_balance_get_fwd_bucket (lb0,
	(hash_c0 &
	(lb0->lb_n_buckets_minus_1)));
	}
	else
	{
	dpo0 = load_balance_get_bucket_i (lb0, 0);
	}
	if (PREDICT_FALSE (lb1->lb_n_buckets > 1))
	{
	flow_hash_config1 = lb1->lb_hash_config;
	hash_c1 = vnet_buffer (p1)->ip.flow_hash =
	ip4_compute_flow_hash (ip1, flow_hash_config1);
	dpo1 =
	load_balance_get_fwd_bucket (lb1,
	(hash_c1 &
	(lb1->lb_n_buckets_minus_1)));
	}
	else
	{
	dpo1 = load_balance_get_bucket_i (lb1, 0);
	}

	next0 = dpo0->dpoi_next_node;
	vnet_buffer (p0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
	next1 = dpo1->dpoi_next_node;
	vnet_buffer (p1)->ip.adj_index[VLIB_TX] = dpo1->dpoi_index;

	vlib_increment_combined_counter
	(cm, thread_index, lb_index0, 1,
	vlib_buffer_length_in_chain (vm, p0));
	vlib_increment_combined_counter
	(cm, thread_index, lb_index1, 1,
	vlib_buffer_length_in_chain (vm, p1));

	vlib_validate_buffer_enqueue_x2 (vm, node, next,
	to_next, n_left_to_next,
	pi0, pi1, next0, next1);
	}
	#endif
	while (n_left_from > 0 && n_left_to_next > 0)
	{
	vlib_buffer_t *p0;
	ip4_header_t *ip0;
	ip_lookup_next_t next0;
	const load_balance_t *lb0;
	ip4_fib_mtrie_t *mtrie0;
	ip4_fib_mtrie_leaf_t leaf0;
	ip4_address_t *dst_addr0;
	u32 pi0, lbi0;
	flow_hash_config_t flow_hash_config0;
	const dpo_id_t *dpo0;
	u32 hash_c0;

	pi0 = from[0];
	to_next[0] = pi0;

	p0 = vlib_get_buffer (vm, pi0);
	ip0 = vlib_buffer_get_current (p0);
	dst_addr0 = &ip0->dst_address;
	ip_lookup_set_buffer_fib_index (im->fib_index_by_sw_if_index, p0);

	if (!lookup_for_responses_to_locally_received_packets)
	{
	mtrie0 = &ip4_fib_get (vnet_buffer (p0)->ip.fib_index)->mtrie;
	leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, dst_addr0);
	}

	if (!lookup_for_responses_to_locally_received_packets)
	leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 2);

	if (!lookup_for_responses_to_locally_received_packets)
	leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 3);

	if (lookup_for_responses_to_locally_received_packets)
	lbi0 = vnet_buffer (p0)->ip.adj_index[VLIB_RX];
	else
	{
	/* Handle default route. */
	lbi0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
	}

	ASSERT (lbi0);
	lb0 = load_balance_get (lbi0);

	ASSERT (lb0->lb_n_buckets > 0);
	ASSERT (is_pow2 (lb0->lb_n_buckets));

	/* Use flow hash to compute multipath adjacency. */
	hash_c0 = vnet_buffer (p0)->ip.flow_hash = 0;
	if (PREDICT_FALSE (lb0->lb_n_buckets > 1))
	{
	flow_hash_config0 = lb0->lb_hash_config;

	hash_c0 = vnet_buffer (p0)->ip.flow_hash =
	ip4_compute_flow_hash (ip0, flow_hash_config0);
	dpo0 =
	load_balance_get_fwd_bucket (lb0,
	(hash_c0 &
	(lb0->lb_n_buckets_minus_1)));
	}
	else
	{
	dpo0 = load_balance_get_bucket_i (lb0, 0);
	}

	next0 = dpo0->dpoi_next_node;
	vnet_buffer (p0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;

	vlib_increment_combined_counter (cm, thread_index, lbi0, 1,
	vlib_buffer_length_in_chain (vm,
	p0));

	from += 1;
	to_next += 1;
	n_left_to_next -= 1;
	n_left_from -= 1;

	if (PREDICT_FALSE (next0 != next))
	{
	n_left_to_next += 1;
	vlib_put_next_frame (vm, node, next, n_left_to_next);
	next = next0;
	vlib_get_next_frame (vm, node, next, to_next, n_left_to_next);
	to_next[0] = pi0;
	to_next += 1;
	n_left_to_next -= 1;
	}
	}

	vlib_put_next_frame (vm, node, next, n_left_to_next);
	}

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

	return frame->n_vectors;
	}

	#endif /* __included_ip4_forward_h__ */

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