ip4_forward.h

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/*
 * 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 <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 = vlib_get_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);

      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, fib_index0, lb_index0;
          u32 pi1, fib_index1, lb_index1;
          u32 pi2, fib_index2, lb_index2;
          u32 pi3, fib_index3, 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;

          fib_index0 =
            vec_elt (im->fib_index_by_sw_if_index,
                     vnet_buffer (p0)->sw_if_index[VLIB_RX]);
          fib_index1 =
            vec_elt (im->fib_index_by_sw_if_index,
                     vnet_buffer (p1)->sw_if_index[VLIB_RX]);
          fib_index2 =
            vec_elt (im->fib_index_by_sw_if_index,
                     vnet_buffer (p2)->sw_if_index[VLIB_RX]);
          fib_index3 =
            vec_elt (im->fib_index_by_sw_if_index,
                     vnet_buffer (p3)->sw_if_index[VLIB_RX]);
          fib_index0 =
            (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
             (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
          fib_index1 =
            (vnet_buffer (p1)->sw_if_index[VLIB_TX] ==
             (u32) ~ 0) ? fib_index1 : vnet_buffer (p1)->sw_if_index[VLIB_TX];
          fib_index2 =
            (vnet_buffer (p2)->sw_if_index[VLIB_TX] ==
             (u32) ~ 0) ? fib_index2 : vnet_buffer (p2)->sw_if_index[VLIB_TX];
          fib_index3 =
            (vnet_buffer (p3)->sw_if_index[VLIB_TX] ==
             (u32) ~ 0) ? fib_index3 : vnet_buffer (p3)->sw_if_index[VLIB_TX];


          if (!lookup_for_responses_to_locally_received_packets)
            {
              mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
              mtrie1 = &ip4_fib_get (fib_index1)->mtrie;
              mtrie2 = &ip4_fib_get (fib_index2)->mtrie;
              mtrie3 = &ip4_fib_get (fib_index3)->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);
        }

      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, fib_index0, 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;

          fib_index0 =
            vec_elt (im->fib_index_by_sw_if_index,
                     vnet_buffer (p0)->sw_if_index[VLIB_RX]);
          fib_index0 =
            (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
             (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];

          if (!lookup_for_responses_to_locally_received_packets)
            {
              mtrie0 = &ip4_fib_get (fib_index0)->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:
 */