DVR: run L3 output features
[vpp.git] / src / vnet / ip / ip4_forward.c
old mode 100644 (file)
new mode 100755 (executable)
index 31b687d..201d391
@@ -49,6 +49,7 @@
 #include <vnet/fib/fib_urpf_list.h>    /* for FIB uRPF check */
 #include <vnet/fib/ip4_fib.h>
 #include <vnet/dpo/load_balance.h>
+#include <vnet/dpo/load_balance_map.h>
 #include <vnet/dpo/classify_dpo.h>
 #include <vnet/mfib/mfib_table.h>      /* for mFIB table and entry creation */
 
  * This file contains the source code for IPv4 forwarding.
  */
 
-void
-ip4_forward_next_trace (vlib_main_t * vm,
-                       vlib_node_runtime_t * node,
-                       vlib_frame_t * frame,
-                       vlib_rx_or_tx_t which_adj_index);
-
 always_inline uword
 ip4_lookup_inline (vlib_main_t * vm,
                   vlib_node_runtime_t * node,
@@ -75,7 +70,7 @@ ip4_lookup_inline (vlib_main_t * vm,
   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 cpu_index = os_get_cpu_number ();
+  u32 thread_index = vlib_get_thread_index ();
 
   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;
@@ -89,20 +84,15 @@ ip4_lookup_inline (vlib_main_t * vm,
        {
          vlib_buffer_t *p0, *p1, *p2, *p3;
          ip4_header_t *ip0, *ip1, *ip2, *ip3;
-         __attribute__ ((unused)) tcp_header_t *tcp0, *tcp1, *tcp2, *tcp3;
          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;
-         __attribute__ ((unused)) u32 pi0, fib_index0, lb_index0,
-           is_tcp_udp0;
-         __attribute__ ((unused)) u32 pi1, fib_index1, lb_index1,
-           is_tcp_udp1;
-         __attribute__ ((unused)) u32 pi2, fib_index2, lb_index2,
-           is_tcp_udp2;
-         __attribute__ ((unused)) u32 pi3, fib_index3, lb_index3,
-           is_tcp_udp3;
+         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;
@@ -186,34 +176,10 @@ ip4_lookup_inline (vlib_main_t * vm,
              mtrie2 = &ip4_fib_get (fib_index2)->mtrie;
              mtrie3 = &ip4_fib_get (fib_index3)->mtrie;
 
-             leaf0 = leaf1 = leaf2 = leaf3 = IP4_FIB_MTRIE_LEAF_ROOT;
-
-             leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 0);
-             leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, dst_addr1, 0);
-             leaf2 = ip4_fib_mtrie_lookup_step (mtrie2, leaf2, dst_addr2, 0);
-             leaf3 = ip4_fib_mtrie_lookup_step (mtrie3, leaf3, dst_addr3, 0);
-           }
-
-         tcp0 = (void *) (ip0 + 1);
-         tcp1 = (void *) (ip1 + 1);
-         tcp2 = (void *) (ip2 + 1);
-         tcp3 = (void *) (ip3 + 1);
-
-         is_tcp_udp0 = (ip0->protocol == IP_PROTOCOL_TCP
-                        || ip0->protocol == IP_PROTOCOL_UDP);
-         is_tcp_udp1 = (ip1->protocol == IP_PROTOCOL_TCP
-                        || ip1->protocol == IP_PROTOCOL_UDP);
-         is_tcp_udp2 = (ip2->protocol == IP_PROTOCOL_TCP
-                        || ip2->protocol == IP_PROTOCOL_UDP);
-         is_tcp_udp3 = (ip1->protocol == IP_PROTOCOL_TCP
-                        || ip1->protocol == IP_PROTOCOL_UDP);
-
-         if (!lookup_for_responses_to_locally_received_packets)
-           {
-             leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 1);
-             leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, dst_addr1, 1);
-             leaf2 = ip4_fib_mtrie_lookup_step (mtrie2, leaf2, dst_addr2, 1);
-             leaf3 = ip4_fib_mtrie_lookup_step (mtrie3, leaf3, dst_addr3, 1);
+             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)
@@ -241,30 +207,27 @@ ip4_lookup_inline (vlib_main_t * vm,
            }
          else
            {
-             /* Handle default route. */
-             leaf0 =
-               (leaf0 ==
-                IP4_FIB_MTRIE_LEAF_EMPTY ? mtrie0->default_leaf : leaf0);
-             leaf1 =
-               (leaf1 ==
-                IP4_FIB_MTRIE_LEAF_EMPTY ? mtrie1->default_leaf : leaf1);
-             leaf2 =
-               (leaf2 ==
-                IP4_FIB_MTRIE_LEAF_EMPTY ? mtrie2->default_leaf : leaf2);
-             leaf3 =
-               (leaf3 ==
-                IP4_FIB_MTRIE_LEAF_EMPTY ? mtrie3->default_leaf : leaf3);
              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;
@@ -275,47 +238,57 @@ ip4_lookup_inline (vlib_main_t * vm,
              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);
            }
-
-         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));
-
-         dpo0 = load_balance_get_bucket_i (lb0,
-                                           (hash_c0 &
-                                            (lb0->lb_n_buckets_minus_1)));
-         dpo1 = load_balance_get_bucket_i (lb1,
-                                           (hash_c1 &
-                                            (lb1->lb_n_buckets_minus_1)));
-         dpo2 = load_balance_get_bucket_i (lb2,
-                                           (hash_c2 &
-                                            (lb2->lb_n_buckets_minus_1)));
-         dpo3 = load_balance_get_bucket_i (lb3,
-                                           (hash_c3 &
-                                            (lb3->lb_n_buckets_minus_1)));
 
          next0 = dpo0->dpoi_next_node;
          vnet_buffer (p0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
@@ -327,21 +300,17 @@ ip4_lookup_inline (vlib_main_t * vm,
          vnet_buffer (p3)->ip.adj_index[VLIB_TX] = dpo3->dpoi_index;
 
          vlib_increment_combined_counter
-           (cm, cpu_index, lb_index0, 1,
-            vlib_buffer_length_in_chain (vm, p0)
-            + sizeof (ethernet_header_t));
+           (cm, thread_index, lb_index0, 1,
+            vlib_buffer_length_in_chain (vm, p0));
          vlib_increment_combined_counter
-           (cm, cpu_index, lb_index1, 1,
-            vlib_buffer_length_in_chain (vm, p1)
-            + sizeof (ethernet_header_t));
+           (cm, thread_index, lb_index1, 1,
+            vlib_buffer_length_in_chain (vm, p1));
          vlib_increment_combined_counter
-           (cm, cpu_index, lb_index2, 1,
-            vlib_buffer_length_in_chain (vm, p2)
-            + sizeof (ethernet_header_t));
+           (cm, thread_index, lb_index2, 1,
+            vlib_buffer_length_in_chain (vm, p2));
          vlib_increment_combined_counter
-           (cm, cpu_index, lb_index3, 1,
-            vlib_buffer_length_in_chain (vm, p3)
-            + sizeof (ethernet_header_t));
+           (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,
@@ -353,13 +322,12 @@ ip4_lookup_inline (vlib_main_t * vm,
        {
          vlib_buffer_t *p0;
          ip4_header_t *ip0;
-         __attribute__ ((unused)) tcp_header_t *tcp0;
          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;
-         __attribute__ ((unused)) u32 pi0, fib_index0, is_tcp_udp0, lbi0;
+         u32 pi0, fib_index0, lbi0;
          flow_hash_config_t flow_hash_config0;
          const dpo_id_t *dpo0;
          u32 hash_c0;
@@ -384,19 +352,9 @@ ip4_lookup_inline (vlib_main_t * vm,
            {
              mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
 
-             leaf0 = IP4_FIB_MTRIE_LEAF_ROOT;
-
-             leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 0);
+             leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, dst_addr0);
            }
 
-         tcp0 = (void *) (ip0 + 1);
-
-         is_tcp_udp0 = (ip0->protocol == IP_PROTOCOL_TCP
-                        || ip0->protocol == IP_PROTOCOL_UDP);
-
-         if (!lookup_for_responses_to_locally_received_packets)
-           leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 1);
-
          if (!lookup_for_responses_to_locally_received_packets)
            leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, dst_addr0, 2);
 
@@ -408,14 +366,15 @@ ip4_lookup_inline (vlib_main_t * vm,
          else
            {
              /* Handle default route. */
-             leaf0 =
-               (leaf0 ==
-                IP4_FIB_MTRIE_LEAF_EMPTY ? mtrie0->default_leaf : leaf0);
              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))
@@ -424,20 +383,22 @@ ip4_lookup_inline (vlib_main_t * vm,
 
              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);
            }
-
-         ASSERT (lb0->lb_n_buckets > 0);
-         ASSERT (is_pow2 (lb0->lb_n_buckets));
-
-         dpo0 = load_balance_get_bucket_i (lb0,
-                                           (hash_c0 &
-                                            (lb0->lb_n_buckets_minus_1)));
 
          next0 = dpo0->dpoi_next_node;
          vnet_buffer (p0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
 
-         vlib_increment_combined_counter
-           (cm, cpu_index, lbi0, 1, vlib_buffer_length_in_chain (vm, p0));
+         vlib_increment_combined_counter (cm, thread_index, lbi0, 1,
+                                          vlib_buffer_length_in_chain (vm,
+                                                                       p0));
 
          from += 1;
          to_next += 1;
@@ -509,11 +470,17 @@ ip4_lookup (vlib_main_t * vm,
 
 static u8 *format_ip4_lookup_trace (u8 * s, va_list * args);
 
+/* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ip4_lookup_node) =
 {
-.function = ip4_lookup,.name = "ip4-lookup",.vector_size =
-    sizeof (u32),.format_trace = format_ip4_lookup_trace,.n_next_nodes =
-    IP_LOOKUP_N_NEXT,.next_nodes = IP4_LOOKUP_NEXT_NODES,};
+  .function = ip4_lookup,
+  .name = "ip4-lookup",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ip4_lookup_trace,
+  .n_next_nodes = IP_LOOKUP_N_NEXT,
+  .next_nodes = IP4_LOOKUP_NEXT_NODES,
+};
+/* *INDENT-ON* */
 
 VLIB_NODE_FUNCTION_MULTIARCH (ip4_lookup_node, ip4_lookup);
 
@@ -524,7 +491,7 @@ ip4_load_balance (vlib_main_t * vm,
   vlib_combined_counter_main_t *cm = &load_balance_main.lbm_via_counters;
   u32 n_left_from, n_left_to_next, *from, *to_next;
   ip_lookup_next_t next;
-  u32 cpu_index = os_get_cpu_number ();
+  u32 thread_index = vlib_get_thread_index ();
 
   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;
@@ -600,6 +567,12 @@ ip4_load_balance (vlib_main_t * vm,
                  hc0 = vnet_buffer (p0)->ip.flow_hash =
                    ip4_compute_flow_hash (ip0, lb0->lb_hash_config);
                }
+             dpo0 = load_balance_get_fwd_bucket
+               (lb0, (hc0 & (lb0->lb_n_buckets_minus_1)));
+           }
+         else
+           {
+             dpo0 = load_balance_get_bucket_i (lb0, 0);
            }
          if (PREDICT_FALSE (lb1->lb_n_buckets > 1))
            {
@@ -613,14 +586,13 @@ ip4_load_balance (vlib_main_t * vm,
                  hc1 = vnet_buffer (p1)->ip.flow_hash =
                    ip4_compute_flow_hash (ip1, lb1->lb_hash_config);
                }
+             dpo1 = load_balance_get_fwd_bucket
+               (lb1, (hc1 & (lb1->lb_n_buckets_minus_1)));
+           }
+         else
+           {
+             dpo1 = load_balance_get_bucket_i (lb1, 0);
            }
-
-         dpo0 =
-           load_balance_get_bucket_i (lb0,
-                                      hc0 & (lb0->lb_n_buckets_minus_1));
-         dpo1 =
-           load_balance_get_bucket_i (lb1,
-                                      hc1 & (lb1->lb_n_buckets_minus_1));
 
          next0 = dpo0->dpoi_next_node;
          next1 = dpo1->dpoi_next_node;
@@ -629,9 +601,9 @@ ip4_load_balance (vlib_main_t * vm,
          vnet_buffer (p1)->ip.adj_index[VLIB_TX] = dpo1->dpoi_index;
 
          vlib_increment_combined_counter
-           (cm, cpu_index, lbi0, 1, vlib_buffer_length_in_chain (vm, p0));
+           (cm, thread_index, lbi0, 1, vlib_buffer_length_in_chain (vm, p0));
          vlib_increment_combined_counter
-           (cm, cpu_index, lbi1, 1, vlib_buffer_length_in_chain (vm, p1));
+           (cm, thread_index, lbi1, 1, vlib_buffer_length_in_chain (vm, p1));
 
          vlib_validate_buffer_enqueue_x2 (vm, node, next,
                                           to_next, n_left_to_next,
@@ -674,17 +646,19 @@ ip4_load_balance (vlib_main_t * vm,
                  hc0 = vnet_buffer (p0)->ip.flow_hash =
                    ip4_compute_flow_hash (ip0, lb0->lb_hash_config);
                }
+             dpo0 = load_balance_get_fwd_bucket
+               (lb0, (hc0 & (lb0->lb_n_buckets_minus_1)));
+           }
+         else
+           {
+             dpo0 = load_balance_get_bucket_i (lb0, 0);
            }
-
-         dpo0 =
-           load_balance_get_bucket_i (lb0,
-                                      hc0 & (lb0->lb_n_buckets_minus_1));
 
          next0 = dpo0->dpoi_next_node;
          vnet_buffer (p0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
 
          vlib_increment_combined_counter
-           (cm, cpu_index, lbi0, 1, vlib_buffer_length_in_chain (vm, p0));
+           (cm, thread_index, lbi0, 1, vlib_buffer_length_in_chain (vm, p0));
 
          vlib_validate_buffer_enqueue_x1 (vm, node, next,
                                           to_next, n_left_to_next,
@@ -697,11 +671,17 @@ ip4_load_balance (vlib_main_t * vm,
   return frame->n_vectors;
 }
 
+/* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ip4_load_balance_node) =
 {
-.function = ip4_load_balance,.name = "ip4-load-balance",.vector_size =
-    sizeof (u32),.sibling_of = "ip4-lookup",.format_trace =
-    format_ip4_lookup_trace,};
+  .function = ip4_load_balance,
+  .name = "ip4-load-balance",
+  .vector_size = sizeof (u32),
+  .sibling_of = "ip4-lookup",
+  .format_trace =
+  format_ip4_lookup_trace,
+};
+/* *INDENT-ON* */
 
 VLIB_NODE_FUNCTION_MULTIARCH (ip4_load_balance_node, ip4_load_balance);
 
@@ -743,29 +723,65 @@ ip4_add_interface_routes (u32 sw_if_index,
     .fp_addr.ip4 = *address,
   };
 
-  a->neighbor_probe_adj_index = ~0;
-
-  if (pfx.fp_len < 32)
+  if (pfx.fp_len <= 30)
     {
-      fib_node_index_t fei;
-
-      fei = fib_table_entry_update_one_path (fib_index, &pfx,
-                                             FIB_SOURCE_INTERFACE,
-                                             (FIB_ENTRY_FLAG_CONNECTED |
-                                              FIB_ENTRY_FLAG_ATTACHED),
-                                             FIB_PROTOCOL_IP4,
-                                             /* No next-hop address */
-                                             NULL,
-                                            sw_if_index,
-                                             // invalid FIB index
-                                             ~0,
-                                            1,
-                                             // no out-label stack
-                                             NULL,
-                                            FIB_ROUTE_PATH_FLAG_NONE);
-      a->neighbor_probe_adj_index = fib_entry_get_adj (fei);
+      /* a /30 or shorter - add a glean for the network address */
+      fib_table_entry_update_one_path (fib_index, &pfx,
+                                       FIB_SOURCE_INTERFACE,
+                                       (FIB_ENTRY_FLAG_CONNECTED |
+                                        FIB_ENTRY_FLAG_ATTACHED),
+                                       DPO_PROTO_IP4,
+                                       /* No next-hop address */
+                                       NULL,
+                                       sw_if_index,
+                                       // invalid FIB index
+                                       ~0,
+                                       1,
+                                       // no out-label stack
+                                       NULL,
+                                       FIB_ROUTE_PATH_FLAG_NONE);
+
+      /* Add the two broadcast addresses as drop */
+      fib_prefix_t net_pfx = {
+        .fp_len = 32,
+        .fp_proto = FIB_PROTOCOL_IP4,
+        .fp_addr.ip4.as_u32 = address->as_u32 & im->fib_masks[pfx.fp_len],
+      };
+      if (net_pfx.fp_addr.ip4.as_u32 != pfx.fp_addr.ip4.as_u32)
+        fib_table_entry_special_add(fib_index,
+                                    &net_pfx,
+                                    FIB_SOURCE_INTERFACE,
+                                    (FIB_ENTRY_FLAG_DROP |
+                                     FIB_ENTRY_FLAG_LOOSE_URPF_EXEMPT));
+      net_pfx.fp_addr.ip4.as_u32 |= ~im->fib_masks[pfx.fp_len];
+      if (net_pfx.fp_addr.ip4.as_u32 != pfx.fp_addr.ip4.as_u32)
+        fib_table_entry_special_add(fib_index,
+                                    &net_pfx,
+                                    FIB_SOURCE_INTERFACE,
+                                    (FIB_ENTRY_FLAG_DROP |
+                                     FIB_ENTRY_FLAG_LOOSE_URPF_EXEMPT));
+    }
+  else if (pfx.fp_len == 31)
+    {
+      u32 mask = clib_host_to_net_u32(1);
+      fib_prefix_t net_pfx = pfx;
+
+      net_pfx.fp_len = 32;
+      net_pfx.fp_addr.ip4.as_u32 ^= mask;
+
+      /* a /31 - add the other end as an attached host */
+      fib_table_entry_update_one_path (fib_index, &net_pfx,
+                                       FIB_SOURCE_INTERFACE,
+                                       (FIB_ENTRY_FLAG_ATTACHED),
+                                       DPO_PROTO_IP4,
+                                       &net_pfx.fp_addr,
+                                       sw_if_index,
+                                       // invalid FIB index
+                                       ~0,
+                                       1,
+                                       NULL,
+                                       FIB_ROUTE_PATH_FLAG_NONE);
     }
-
   pfx.fp_len = 32;
 
   if (sw_if_index < vec_len (lm->classify_table_index_by_sw_if_index))
@@ -793,7 +809,7 @@ ip4_add_interface_routes (u32 sw_if_index,
                                    FIB_SOURCE_INTERFACE,
                                    (FIB_ENTRY_FLAG_CONNECTED |
                                     FIB_ENTRY_FLAG_LOCAL),
-                                   FIB_PROTOCOL_IP4,
+                                   DPO_PROTO_IP4,
                                    &pfx.fp_addr,
                                    sw_if_index,
                                    // invalid FIB index
@@ -813,10 +829,34 @@ ip4_del_interface_routes (ip4_main_t * im,
     .fp_addr.ip4 = *address,
   };
 
-  if (pfx.fp_len < 32)
+  if (pfx.fp_len <= 30)
     {
+      fib_prefix_t net_pfx = {
+        .fp_len = 32,
+        .fp_proto = FIB_PROTOCOL_IP4,
+        .fp_addr.ip4.as_u32 = address->as_u32 & im->fib_masks[pfx.fp_len],
+      };
+      if (net_pfx.fp_addr.ip4.as_u32 != pfx.fp_addr.ip4.as_u32)
+        fib_table_entry_special_remove(fib_index,
+                                       &net_pfx,
+                                       FIB_SOURCE_INTERFACE);
+      net_pfx.fp_addr.ip4.as_u32 |= ~im->fib_masks[pfx.fp_len];
+      if (net_pfx.fp_addr.ip4.as_u32 != pfx.fp_addr.ip4.as_u32)
+        fib_table_entry_special_remove(fib_index,
+                                       &net_pfx,
+                                       FIB_SOURCE_INTERFACE);
       fib_table_entry_delete (fib_index, &pfx, FIB_SOURCE_INTERFACE);
     }
+    else if (pfx.fp_len == 31)
+    {
+      u32 mask = clib_host_to_net_u32(1);
+      fib_prefix_t net_pfx = pfx;
+
+      net_pfx.fp_len = 32;
+      net_pfx.fp_addr.ip4.as_u32 ^= mask;
+
+      fib_table_entry_delete (fib_index, &net_pfx, FIB_SOURCE_INTERFACE);
+    }
 
   pfx.fp_len = 32;
   fib_table_entry_delete (fib_index, &pfx, FIB_SOURCE_INTERFACE);
@@ -847,9 +887,8 @@ ip4_sw_interface_enable_disable (u32 sw_if_index, u32 is_enable)
                               !is_enable, 0, 0);
 
 
-  vnet_feature_enable_disable ("ip4-multicast",
-                              "ip4-mfib-forward-lookup",
-                              sw_if_index, is_enable, 0, 0);
+  vnet_feature_enable_disable ("ip4-multicast", "ip4-drop",
+                              sw_if_index, !is_enable, 0, 0);
 }
 
 static clib_error_t *
@@ -865,6 +904,13 @@ ip4_add_del_interface_address_internal (vlib_main_t * vm,
   u32 if_address_index, elts_before;
   ip4_address_fib_t ip4_af, *addr_fib = 0;
 
+  /* local0 interface doesn't support IP addressing  */
+  if (sw_if_index == 0)
+    {
+      return
+       clib_error_create ("local0 interface doesn't support IP addressing");
+    }
+
   vec_validate (im->fib_index_by_sw_if_index, sw_if_index);
   ip4_addr_fib_init (&ip4_af, address,
                     vec_elt (im->fib_index_by_sw_if_index, sw_if_index));
@@ -954,7 +1000,6 @@ VNET_FEATURE_ARC_INIT (ip4_unicast, static) =
 {
   .arc_name = "ip4-unicast",
   .start_nodes = VNET_FEATURES ("ip4-input", "ip4-input-no-checksum"),
-  .end_node = "ip4-lookup",
   .arc_index_ptr = &ip4_main.lookup_main.ucast_feature_arc_index,
 };
 
@@ -1021,27 +1066,25 @@ VNET_FEATURE_INIT (ip4_vxlan_bypass, static) =
   .runs_before = VNET_FEATURES ("ip4-lookup"),
 };
 
-VNET_FEATURE_INIT (ip4_lookup, static) =
+VNET_FEATURE_INIT (ip4_drop, static) =
 {
   .arc_name = "ip4-unicast",
-  .node_name = "ip4-lookup",
-  .runs_before = VNET_FEATURES ("ip4-drop"),
+  .node_name = "ip4-drop",
+  .runs_before = VNET_FEATURES ("ip4-lookup"),
 };
 
-VNET_FEATURE_INIT (ip4_drop, static) =
+VNET_FEATURE_INIT (ip4_lookup, static) =
 {
   .arc_name = "ip4-unicast",
-  .node_name = "ip4-drop",
+  .node_name = "ip4-lookup",
   .runs_before = 0,    /* not before any other features */
 };
 
-
 /* Built-in ip4 multicast rx feature path definition */
 VNET_FEATURE_ARC_INIT (ip4_multicast, static) =
 {
   .arc_name = "ip4-multicast",
   .start_nodes = VNET_FEATURES ("ip4-input", "ip4-input-no-checksum"),
-  .end_node = "ip4-lookup-multicast",
   .arc_index_ptr = &ip4_main.lookup_main.mcast_feature_arc_index,
 };
 
@@ -1052,17 +1095,17 @@ VNET_FEATURE_INIT (ip4_vpath_mc, static) =
   .runs_before = VNET_FEATURES ("ip4-mfib-forward-lookup"),
 };
 
-VNET_FEATURE_INIT (ip4_lookup_mc, static) =
+VNET_FEATURE_INIT (ip4_mc_drop, static) =
 {
   .arc_name = "ip4-multicast",
-  .node_name = "ip4-mfib-forward-lookup",
-  .runs_before = VNET_FEATURES ("ip4-drop"),
+  .node_name = "ip4-drop",
+  .runs_before = VNET_FEATURES ("ip4-mfib-forward-lookup"),
 };
 
-VNET_FEATURE_INIT (ip4_mc_drop, static) =
+VNET_FEATURE_INIT (ip4_lookup_mc, static) =
 {
   .arc_name = "ip4-multicast",
-  .node_name = "ip4-drop",
+  .node_name = "ip4-mfib-forward-lookup",
   .runs_before = 0,    /* last feature */
 };
 
@@ -1070,8 +1113,7 @@ VNET_FEATURE_INIT (ip4_mc_drop, static) =
 VNET_FEATURE_ARC_INIT (ip4_output, static) =
 {
   .arc_name = "ip4-output",
-  .start_nodes = VNET_FEATURES ("ip4-rewrite", "ip4-midchain"),
-  .end_node = "interface-output",
+  .start_nodes = VNET_FEATURES ("ip4-rewrite", "ip4-midchain", "ip4-dvr-dpo"),
   .arc_index_ptr = &ip4_main.lookup_main.output_feature_arc_index,
 };
 
@@ -1107,6 +1149,23 @@ ip4_sw_interface_add_del (vnet_main_t * vnm, u32 sw_if_index, u32 is_add)
   vec_validate (im->fib_index_by_sw_if_index, sw_if_index);
   vec_validate (im->mfib_index_by_sw_if_index, sw_if_index);
 
+  if (!is_add)
+    {
+      ip4_main_t *im4 = &ip4_main;
+      ip_lookup_main_t *lm4 = &im4->lookup_main;
+      ip_interface_address_t *ia = 0;
+      ip4_address_t *address;
+      vlib_main_t *vm = vlib_get_main ();
+
+      /* *INDENT-OFF* */
+      foreach_ip_interface_address (lm4, ia, sw_if_index, 1 /* honor unnumbered */,
+      ({
+        address = ip_interface_address_get_address (lm4, ia);
+        ip4_add_del_interface_address(vm, sw_if_index, address, ia->address_length, 1);
+      }));
+      /* *INDENT-ON* */
+    }
+
   vnet_feature_enable_disable ("ip4-unicast", "ip4-drop", sw_if_index,
                               is_add, 0, 0);
 
@@ -1130,6 +1189,12 @@ ip4_lookup_init (vlib_main_t * vm)
 
   if ((error = vlib_call_init_function (vm, vnet_feature_init)))
     return error;
+  if ((error = vlib_call_init_function (vm, ip4_mtrie_module_init)))
+    return (error);
+  if ((error = vlib_call_init_function (vm, fib_module_init)))
+    return error;
+  if ((error = vlib_call_init_function (vm, mfib_module_init)))
+    return error;
 
   for (i = 0; i < ARRAY_LEN (im->fib_masks); i++)
     {
@@ -1145,8 +1210,10 @@ ip4_lookup_init (vlib_main_t * vm)
   ip_lookup_init (&im->lookup_main, /* is_ip6 */ 0);
 
   /* Create FIB with index 0 and table id of 0. */
-  fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, 0);
-  mfib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, 0);
+  fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, 0,
+                                    FIB_SOURCE_DEFAULT_ROUTE);
+  mfib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, 0,
+                                     MFIB_SOURCE_DEFAULT_ROUTE);
 
   {
     pg_node_t *pn;
@@ -1203,7 +1270,7 @@ format_ip4_forward_next_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 *);
   ip4_forward_next_trace_t *t = va_arg (*args, ip4_forward_next_trace_t *);
-  uword indent = format_get_indent (s);
+  u32 indent = format_get_indent (s);
   s = format (s, "%U%U",
              format_white_space, indent,
              format_ip4_header, t->packet_data, sizeof (t->packet_data));
@@ -1216,7 +1283,7 @@ format_ip4_lookup_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 *);
   ip4_forward_next_trace_t *t = va_arg (*args, ip4_forward_next_trace_t *);
-  uword indent = format_get_indent (s);
+  u32 indent = format_get_indent (s);
 
   s = format (s, "fib %d dpo-idx %d flow hash: 0x%08x",
              t->fib_index, t->dpo_index, t->flow_hash);
@@ -1232,8 +1299,7 @@ format_ip4_rewrite_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 *);
   ip4_forward_next_trace_t *t = va_arg (*args, ip4_forward_next_trace_t *);
-  vnet_main_t *vnm = vnet_get_main ();
-  uword indent = format_get_indent (s);
+  u32 indent = format_get_indent (s);
 
   s = format (s, "tx_sw_if_index %d dpo-idx %d : %U flow hash: 0x%08x",
              t->fib_index, t->dpo_index, format_ip_adjacency,
@@ -1241,7 +1307,7 @@ format_ip4_rewrite_trace (u8 * s, va_list * args)
   s = format (s, "\n%U%U",
              format_white_space, indent,
              format_ip_adjacency_packet_data,
-             vnm, t->dpo_index, t->packet_data, sizeof (t->packet_data));
+             t->dpo_index, t->packet_data, sizeof (t->packet_data));
   return s;
 }
 
@@ -1333,68 +1399,6 @@ ip4_forward_next_trace (vlib_main_t * vm,
     }
 }
 
-static uword
-ip4_drop_or_punt (vlib_main_t * vm,
-                 vlib_node_runtime_t * node,
-                 vlib_frame_t * frame, ip4_error_t error_code)
-{
-  u32 *buffers = vlib_frame_vector_args (frame);
-  uword n_packets = frame->n_vectors;
-
-  vlib_error_drop_buffers (vm, node, buffers,
-                          /* stride */ 1,
-                          n_packets,
-                          /* next */ 0,
-                          ip4_input_node.index, error_code);
-
-  if (node->flags & VLIB_NODE_FLAG_TRACE)
-    ip4_forward_next_trace (vm, node, frame, VLIB_TX);
-
-  return n_packets;
-}
-
-static uword
-ip4_drop (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  return ip4_drop_or_punt (vm, node, frame, IP4_ERROR_ADJACENCY_DROP);
-}
-
-static uword
-ip4_punt (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  return ip4_drop_or_punt (vm, node, frame, IP4_ERROR_ADJACENCY_PUNT);
-}
-
-/* *INDENT-OFF* */
-VLIB_REGISTER_NODE (ip4_drop_node, static) =
-{
-  .function = ip4_drop,.
-  name = "ip4-drop",
-  .vector_size = sizeof (u32),
-  .format_trace = format_ip4_forward_next_trace,
-  .n_next_nodes = 1,
-  .next_nodes = {
-    [0] = "error-drop",
-  },
-};
-
-VLIB_NODE_FUNCTION_MULTIARCH (ip4_drop_node, ip4_drop);
-
-VLIB_REGISTER_NODE (ip4_punt_node, static) =
-{
-  .function = ip4_punt,
-  .name = "ip4-punt",
-  .vector_size = sizeof (u32),
-  .format_trace = format_ip4_forward_next_trace,
-  .n_next_nodes = 1,
-  .next_nodes = {
-    [0] = "error-punt",
-  },
-};
-
-VLIB_NODE_FUNCTION_MULTIARCH (ip4_punt_node, ip4_punt);
-/* *INDENT-ON */
-
 /* Compute TCP/UDP/ICMP4 checksum in software. */
 u16
 ip4_tcp_udp_compute_checksum (vlib_main_t * vm, vlib_buffer_t * p0,
@@ -1402,7 +1406,7 @@ ip4_tcp_udp_compute_checksum (vlib_main_t * vm, vlib_buffer_t * p0,
 {
   ip_csum_t sum0;
   u32 ip_header_length, payload_length_host_byte_order;
-  u32 n_this_buffer, n_bytes_left;
+  u32 n_this_buffer, n_bytes_left, n_ip_bytes_this_buffer;
   u16 sum16;
   void *data_this_buffer;
 
@@ -1429,10 +1433,13 @@ ip4_tcp_udp_compute_checksum (vlib_main_t * vm, vlib_buffer_t * p0,
 
   n_bytes_left = n_this_buffer = payload_length_host_byte_order;
   data_this_buffer = (void *) ip0 + ip_header_length;
-  if (n_this_buffer + ip_header_length > p0->current_length)
-    n_this_buffer =
-      p0->current_length >
-      ip_header_length ? p0->current_length - ip_header_length : 0;
+  n_ip_bytes_this_buffer =
+    p0->current_length - (((u8 *) ip0 - p0->data) - p0->current_data);
+  if (n_this_buffer + ip_header_length > n_ip_bytes_this_buffer)
+    {
+      n_this_buffer = n_ip_bytes_this_buffer > ip_header_length ?
+       n_ip_bytes_this_buffer - ip_header_length : 0;
+    }
   while (1)
     {
       sum0 = ip_incremental_checksum (sum0, data_this_buffer, n_this_buffer);
@@ -1464,15 +1471,15 @@ ip4_tcp_udp_validate_checksum (vlib_main_t * vm, vlib_buffer_t * p0)
   udp0 = (void *) (ip0 + 1);
   if (ip0->protocol == IP_PROTOCOL_UDP && udp0->checksum == 0)
     {
-      p0->flags |= (IP_BUFFER_L4_CHECKSUM_COMPUTED
-                   | IP_BUFFER_L4_CHECKSUM_CORRECT);
+      p0->flags |= (VNET_BUFFER_F_L4_CHECKSUM_COMPUTED
+                   | VNET_BUFFER_F_L4_CHECKSUM_CORRECT);
       return p0->flags;
     }
 
   sum16 = ip4_tcp_udp_compute_checksum (vm, p0, ip0);
 
-  p0->flags |= (IP_BUFFER_L4_CHECKSUM_COMPUTED
-               | ((sum16 == 0) << LOG2_IP_BUFFER_L4_CHECKSUM_CORRECT));
+  p0->flags |= (VNET_BUFFER_F_L4_CHECKSUM_COMPUTED
+               | ((sum16 == 0) << VNET_BUFFER_F_LOG2_L4_CHECKSUM_CORRECT));
 
   return p0->flags;
 }
@@ -1485,6 +1492,34 @@ VNET_FEATURE_ARC_INIT (ip4_local) =
 };
 /* *INDENT-ON* */
 
+static inline void
+ip4_local_validate_l4 (vlib_main_t * vm, vlib_buffer_t * p, ip4_header_t * ip,
+                      u8 is_udp, u8 * error, u8 * good_tcp_udp)
+{
+  u32 flags0;
+  flags0 = ip4_tcp_udp_validate_checksum (vm, p);
+  *good_tcp_udp = (flags0 & VNET_BUFFER_F_L4_CHECKSUM_CORRECT) != 0;
+  if (is_udp)
+    {
+      udp_header_t *udp;
+      u32 ip_len, udp_len;
+      i32 len_diff;
+      udp = ip4_next_header (ip);
+      /* Verify UDP length. */
+      ip_len = clib_net_to_host_u16 (ip->length);
+      udp_len = clib_net_to_host_u16 (udp->length);
+
+      len_diff = ip_len - udp_len;
+      *good_tcp_udp &= len_diff >= 0;
+      *error = len_diff < 0 ? IP4_ERROR_UDP_LENGTH : *error;
+    }
+}
+
+#define ip4_local_do_l4_check(is_tcp_udp, flags)                       \
+    (is_tcp_udp && !(flags & VNET_BUFFER_F_L4_CHECKSUM_COMPUTED \
+    || flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM \
+    || flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM))
+
 static inline uword
 ip4_local_inline (vlib_main_t * vm,
                  vlib_node_runtime_t * node,
@@ -1513,14 +1548,12 @@ ip4_local_inline (vlib_main_t * vm,
        {
          vlib_buffer_t *p0, *p1;
          ip4_header_t *ip0, *ip1;
-         udp_header_t *udp0, *udp1;
          ip4_fib_mtrie_t *mtrie0, *mtrie1;
          ip4_fib_mtrie_leaf_t leaf0, leaf1;
          const dpo_id_t *dpo0, *dpo1;
          const load_balance_t *lb0, *lb1;
-         u32 pi0, ip_len0, udp_len0, flags0, next0, fib_index0, lbi0;
-         u32 pi1, ip_len1, udp_len1, flags1, next1, fib_index1, lbi1;
-         i32 len_diff0, len_diff1;
+         u32 pi0, next0, fib_index0, lbi0;
+         u32 pi1, next1, fib_index1, lbi1;
          u8 error0, is_udp0, is_tcp_udp0, good_tcp_udp0, proto0;
          u8 error1, is_udp1, is_tcp_udp1, good_tcp_udp1, proto1;
          u32 sw_if_index0, sw_if_index1;
@@ -1533,6 +1566,7 @@ ip4_local_inline (vlib_main_t * vm,
          n_left_to_next -= 2;
 
          next0 = next1 = IP_LOCAL_NEXT_DROP;
+         error0 = error1 = IP4_ERROR_UNKNOWN_PROTOCOL;
 
          p0 = vlib_get_buffer (vm, pi0);
          p1 = vlib_get_buffer (vm, pi1);
@@ -1540,133 +1574,79 @@ ip4_local_inline (vlib_main_t * vm,
          ip0 = vlib_buffer_get_current (p0);
          ip1 = vlib_buffer_get_current (p1);
 
-         vnet_buffer (p0)->ip.start_of_ip_header = p0->current_data;
-         vnet_buffer (p1)->ip.start_of_ip_header = p1->current_data;
+         vnet_buffer (p0)->l3_hdr_offset = p0->current_data;
+         vnet_buffer (p1)->l3_hdr_offset = p1->current_data;
 
          sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
          sw_if_index1 = vnet_buffer (p1)->sw_if_index[VLIB_RX];
 
-         fib_index0 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index0);
-         fib_index1 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index1);
-
-         fib_index0 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index0);
-         fib_index0 =
-           (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
-            (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
-
-         fib_index1 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index1);
-         fib_index1 =
-           (vnet_buffer (p1)->sw_if_index[VLIB_TX] ==
-            (u32) ~ 0) ? fib_index1 : vnet_buffer (p1)->sw_if_index[VLIB_TX];
-
-         mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
-         mtrie1 = &ip4_fib_get (fib_index1)->mtrie;
-
-         leaf0 = leaf1 = IP4_FIB_MTRIE_LEAF_ROOT;
-
-         leaf0 =
-           ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 0);
-         leaf1 =
-           ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 0);
-
          /* Treat IP frag packets as "experimental" protocol for now
             until support of IP frag reassembly is implemented */
          proto0 = ip4_is_fragment (ip0) ? 0xfe : ip0->protocol;
          proto1 = ip4_is_fragment (ip1) ? 0xfe : ip1->protocol;
 
          if (head_of_feature_arc == 0)
-           {
-             error0 = error1 = IP4_ERROR_UNKNOWN_PROTOCOL;
-             goto skip_checks;
-           }
+           goto skip_checks;
 
          is_udp0 = proto0 == IP_PROTOCOL_UDP;
          is_udp1 = proto1 == IP_PROTOCOL_UDP;
          is_tcp_udp0 = is_udp0 || proto0 == IP_PROTOCOL_TCP;
          is_tcp_udp1 = is_udp1 || proto1 == IP_PROTOCOL_TCP;
 
-         flags0 = p0->flags;
-         flags1 = p1->flags;
-
-         good_tcp_udp0 = (flags0 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;
-         good_tcp_udp1 = (flags1 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;
-
-         udp0 = ip4_next_header (ip0);
-         udp1 = ip4_next_header (ip1);
-
-         /* Don't verify UDP checksum for packets with explicit zero checksum. */
-         good_tcp_udp0 |= is_udp0 && udp0->checksum == 0;
-         good_tcp_udp1 |= is_udp1 && udp1->checksum == 0;
-
-         leaf0 =
-           ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 1);
-         leaf1 =
-           ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 1);
-
-         /* Verify UDP length. */
-         ip_len0 = clib_net_to_host_u16 (ip0->length);
-         ip_len1 = clib_net_to_host_u16 (ip1->length);
-         udp_len0 = clib_net_to_host_u16 (udp0->length);
-         udp_len1 = clib_net_to_host_u16 (udp1->length);
-
-         len_diff0 = ip_len0 - udp_len0;
-         len_diff1 = ip_len1 - udp_len1;
-
-         len_diff0 = is_udp0 ? len_diff0 : 0;
-         len_diff1 = is_udp1 ? len_diff1 : 0;
-
-         if (PREDICT_FALSE (!(is_tcp_udp0 & is_tcp_udp1
-                              & good_tcp_udp0 & good_tcp_udp1)))
+         good_tcp_udp0 =
+           (p0->flags & VNET_BUFFER_F_L4_CHECKSUM_CORRECT
+            || (p0->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM
+                || p0->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)) != 0;
+         good_tcp_udp1 = (p1->flags & VNET_BUFFER_F_L4_CHECKSUM_CORRECT
+                          || (p1->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM
+                              || p1->flags &
+                              VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)) != 0;
+
+         if (PREDICT_FALSE (ip4_local_do_l4_check (is_tcp_udp0, p0->flags)
+                            || ip4_local_do_l4_check (is_tcp_udp1,
+                                                      p1->flags)))
            {
              if (is_tcp_udp0)
-               {
-                 if (is_tcp_udp0
-                     && !(flags0 & IP_BUFFER_L4_CHECKSUM_COMPUTED))
-                   flags0 = ip4_tcp_udp_validate_checksum (vm, p0);
-                 good_tcp_udp0 =
-                   (flags0 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;
-                 good_tcp_udp0 |= is_udp0 && udp0->checksum == 0;
-               }
+               ip4_local_validate_l4 (vm, p0, ip0, is_udp0, &error0,
+                                      &good_tcp_udp0);
              if (is_tcp_udp1)
-               {
-                 if (is_tcp_udp1
-                     && !(flags1 & IP_BUFFER_L4_CHECKSUM_COMPUTED))
-                   flags1 = ip4_tcp_udp_validate_checksum (vm, p1);
-                 good_tcp_udp1 =
-                   (flags1 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;
-                 good_tcp_udp1 |= is_udp1 && udp1->checksum == 0;
-               }
+               ip4_local_validate_l4 (vm, p1, ip1, is_udp1, &error1,
+                                      &good_tcp_udp1);
            }
 
-         good_tcp_udp0 &= len_diff0 >= 0;
-         good_tcp_udp1 &= len_diff1 >= 0;
-
-         leaf0 =
-           ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 2);
-         leaf1 =
-           ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 2);
-
-         error0 = error1 = IP4_ERROR_UNKNOWN_PROTOCOL;
-
-         error0 = len_diff0 < 0 ? IP4_ERROR_UDP_LENGTH : error0;
-         error1 = len_diff1 < 0 ? IP4_ERROR_UDP_LENGTH : error1;
-
          ASSERT (IP4_ERROR_TCP_CHECKSUM + 1 == IP4_ERROR_UDP_CHECKSUM);
          error0 = (is_tcp_udp0 && !good_tcp_udp0
                    ? IP4_ERROR_TCP_CHECKSUM + is_udp0 : error0);
          error1 = (is_tcp_udp1 && !good_tcp_udp1
                    ? IP4_ERROR_TCP_CHECKSUM + is_udp1 : error1);
 
-         leaf0 =
-           ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
-         leaf1 =
-           ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address, 3);
-         leaf0 =
-           (leaf0 ==
-            IP4_FIB_MTRIE_LEAF_EMPTY ? mtrie0->default_leaf : leaf0);
-         leaf1 =
-           (leaf1 ==
-            IP4_FIB_MTRIE_LEAF_EMPTY ? mtrie1->default_leaf : leaf1);
+         fib_index0 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index0);
+         fib_index0 =
+           (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
+            (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
+
+         fib_index1 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index1);
+         fib_index1 =
+           (vnet_buffer (p1)->sw_if_index[VLIB_TX] ==
+            (u32) ~ 0) ? fib_index1 : vnet_buffer (p1)->sw_if_index[VLIB_TX];
+
+         /* TODO maybe move to lookup? */
+         vnet_buffer (p0)->ip.fib_index = fib_index0;
+         vnet_buffer (p1)->ip.fib_index = fib_index1;
+
+         mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
+         mtrie1 = &ip4_fib_get (fib_index1)->mtrie;
+
+         leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, &ip0->src_address);
+         leaf1 = ip4_fib_mtrie_lookup_step_one (mtrie1, &ip1->src_address);
+         leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address,
+                                            2);
+         leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address,
+                                            2);
+         leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address,
+                                            3);
+         leaf1 = ip4_fib_mtrie_lookup_step (mtrie1, leaf1, &ip1->src_address,
+                                            3);
 
          vnet_buffer (p0)->ip.adj_index[VLIB_RX] = lbi0 =
            ip4_fib_mtrie_leaf_get_adj_index (leaf0);
@@ -1691,6 +1671,9 @@ ip4_local_inline (vlib_main_t * vm,
           *  - uRPF check for any route to source - accept if passes.
           *  - allow packets destined to the broadcast address from unknown sources
           */
+         if (p0->flags & VNET_BUFFER_F_IS_NATED)
+           goto skip_check0;
+
          error0 = ((error0 == IP4_ERROR_UNKNOWN_PROTOCOL &&
                     dpo0->dpoi_type == DPO_RECEIVE) ?
                    IP4_ERROR_SPOOFED_LOCAL_PACKETS : error0);
@@ -1698,6 +1681,11 @@ ip4_local_inline (vlib_main_t * vm,
                     !fib_urpf_check_size (lb0->lb_urpf) &&
                     ip0->dst_address.as_u32 != 0xFFFFFFFF)
                    ? IP4_ERROR_SRC_LOOKUP_MISS : error0);
+
+       skip_check0:
+         if (p1->flags & VNET_BUFFER_F_IS_NATED)
+           goto skip_checks;
+
          error1 = ((error1 == IP4_ERROR_UNKNOWN_PROTOCOL &&
                     dpo1->dpoi_type == DPO_RECEIVE) ?
                    IP4_ERROR_SPOOFED_LOCAL_PACKETS : error1);
@@ -1706,10 +1694,11 @@ ip4_local_inline (vlib_main_t * vm,
                     ip1->dst_address.as_u32 != 0xFFFFFFFF)
                    ? IP4_ERROR_SRC_LOOKUP_MISS : error1);
 
+       skip_checks:
+
          next0 = lm->local_next_by_ip_protocol[proto0];
          next1 = lm->local_next_by_ip_protocol[proto1];
 
-       skip_checks:
          next0 =
            error0 != IP4_ERROR_UNKNOWN_PROTOCOL ? IP_LOCAL_NEXT_DROP : next0;
          next1 =
@@ -1735,11 +1724,9 @@ ip4_local_inline (vlib_main_t * vm,
        {
          vlib_buffer_t *p0;
          ip4_header_t *ip0;
-         udp_header_t *udp0;
          ip4_fib_mtrie_t *mtrie0;
          ip4_fib_mtrie_leaf_t leaf0;
-         u32 pi0, next0, ip_len0, udp_len0, flags0, fib_index0, lbi0;
-         i32 len_diff0;
+         u32 pi0, next0, fib_index0, lbi0;
          u8 error0, is_udp0, is_tcp_udp0, good_tcp_udp0, proto0;
          load_balance_t *lb0;
          const dpo_id_t *dpo0;
@@ -1752,102 +1739,56 @@ ip4_local_inline (vlib_main_t * vm,
          n_left_to_next -= 1;
 
          next0 = IP_LOCAL_NEXT_DROP;
+         error0 = IP4_ERROR_UNKNOWN_PROTOCOL;
 
          p0 = vlib_get_buffer (vm, pi0);
-
          ip0 = vlib_buffer_get_current (p0);
-
-         vnet_buffer (p0)->ip.start_of_ip_header = p0->current_data;
-
+         vnet_buffer (p0)->l3_hdr_offset = p0->current_data;
          sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
 
-         fib_index0 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index0);
-
-         fib_index0 =
-           (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
-            (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
-
-         mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
-
-         leaf0 = IP4_FIB_MTRIE_LEAF_ROOT;
-
-         leaf0 =
-           ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 0);
-
          /* Treat IP frag packets as "experimental" protocol for now
             until support of IP frag reassembly is implemented */
          proto0 = ip4_is_fragment (ip0) ? 0xfe : ip0->protocol;
 
-         if (head_of_feature_arc == 0)
-           {
-             error0 = IP4_ERROR_UNKNOWN_PROTOCOL;
-             goto skip_check;
-           }
+         if (head_of_feature_arc == 0 || p0->flags & VNET_BUFFER_F_IS_NATED)
+           goto skip_check;
 
          is_udp0 = proto0 == IP_PROTOCOL_UDP;
          is_tcp_udp0 = is_udp0 || proto0 == IP_PROTOCOL_TCP;
 
-         flags0 = p0->flags;
-
-         good_tcp_udp0 = (flags0 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;
-
-         udp0 = ip4_next_header (ip0);
+         good_tcp_udp0 =
+           (p0->flags & VNET_BUFFER_F_L4_CHECKSUM_CORRECT
+            || (p0->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM
+                || p0->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)) != 0;
 
-         /* Don't verify UDP checksum for packets with explicit zero checksum. */
-         good_tcp_udp0 |= is_udp0 && udp0->checksum == 0;
-
-         leaf0 =
-           ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 1);
-
-         /* Verify UDP length. */
-         ip_len0 = clib_net_to_host_u16 (ip0->length);
-         udp_len0 = clib_net_to_host_u16 (udp0->length);
-
-         len_diff0 = ip_len0 - udp_len0;
-
-         len_diff0 = is_udp0 ? len_diff0 : 0;
-
-         if (PREDICT_FALSE (!(is_tcp_udp0 & good_tcp_udp0)))
+         if (PREDICT_FALSE (ip4_local_do_l4_check (is_tcp_udp0, p0->flags)))
            {
-             if (is_tcp_udp0)
-               {
-                 if (is_tcp_udp0
-                     && !(flags0 & IP_BUFFER_L4_CHECKSUM_COMPUTED))
-                   flags0 = ip4_tcp_udp_validate_checksum (vm, p0);
-                 good_tcp_udp0 =
-                   (flags0 & IP_BUFFER_L4_CHECKSUM_CORRECT) != 0;
-                 good_tcp_udp0 |= is_udp0 && udp0->checksum == 0;
-               }
+             ip4_local_validate_l4 (vm, p0, ip0, is_udp0, &error0,
+                                    &good_tcp_udp0);
            }
 
-         good_tcp_udp0 &= len_diff0 >= 0;
-
-         leaf0 =
-           ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 2);
-
-         error0 = IP4_ERROR_UNKNOWN_PROTOCOL;
-
-         error0 = len_diff0 < 0 ? IP4_ERROR_UDP_LENGTH : error0;
-
          ASSERT (IP4_ERROR_TCP_CHECKSUM + 1 == IP4_ERROR_UDP_CHECKSUM);
          error0 = (is_tcp_udp0 && !good_tcp_udp0
                    ? IP4_ERROR_TCP_CHECKSUM + is_udp0 : error0);
 
-         leaf0 =
-           ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
-         leaf0 =
-           (leaf0 ==
-            IP4_FIB_MTRIE_LEAF_EMPTY ? mtrie0->default_leaf : leaf0);
-
+         fib_index0 = vec_elt (im->fib_index_by_sw_if_index, sw_if_index0);
+         fib_index0 =
+           (vnet_buffer (p0)->sw_if_index[VLIB_TX] ==
+            (u32) ~ 0) ? fib_index0 : vnet_buffer (p0)->sw_if_index[VLIB_TX];
+         vnet_buffer (p0)->ip.fib_index = fib_index0;
+         mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
+         leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, &ip0->src_address);
+         leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address,
+                                            2);
+         leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address,
+                                            3);
          lbi0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
          vnet_buffer (p0)->ip.adj_index[VLIB_TX] = lbi0;
+         vnet_buffer (p0)->ip.adj_index[VLIB_RX] = lbi0;
 
          lb0 = load_balance_get (lbi0);
          dpo0 = load_balance_get_bucket_i (lb0, 0);
 
-         vnet_buffer (p0)->ip.adj_index[VLIB_TX] =
-           vnet_buffer (p0)->ip.adj_index[VLIB_RX] = lbi0;
-
          error0 = ((error0 == IP4_ERROR_UNKNOWN_PROTOCOL &&
                     dpo0->dpoi_type == DPO_RECEIVE) ?
                    IP4_ERROR_SPOOFED_LOCAL_PACKETS : error0);
@@ -1857,9 +1798,7 @@ ip4_local_inline (vlib_main_t * vm,
                    ? IP4_ERROR_SRC_LOOKUP_MISS : error0);
 
        skip_check:
-
          next0 = lm->local_next_by_ip_protocol[proto0];
-
          next0 =
            error0 != IP4_ERROR_UNKNOWN_PROTOCOL ? IP_LOCAL_NEXT_DROP : next0;
 
@@ -1873,9 +1812,7 @@ ip4_local_inline (vlib_main_t * vm,
 
          vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
                                           n_left_to_next, pi0, next0);
-
        }
-
       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
     }
 
@@ -1898,10 +1835,11 @@ VLIB_REGISTER_NODE (ip4_local_node) =
   .n_next_nodes = IP_LOCAL_N_NEXT,
   .next_nodes =
   {
-    [IP_LOCAL_NEXT_DROP] = "error-drop",
-    [IP_LOCAL_NEXT_PUNT] = "error-punt",
+    [IP_LOCAL_NEXT_DROP] = "ip4-drop",
+    [IP_LOCAL_NEXT_PUNT] = "ip4-punt",
     [IP_LOCAL_NEXT_UDP_LOOKUP] = "ip4-udp-lookup",
-    [IP_LOCAL_NEXT_ICMP] = "ip4-icmp-input",},
+    [IP_LOCAL_NEXT_ICMP] = "ip4-icmp-input",
+  },
 };
 /* *INDENT-ON* */
 
@@ -1957,7 +1895,13 @@ show_ip_local_command_fn (vlib_main_t * vm,
   for (i = 0; i < ARRAY_LEN (lm->local_next_by_ip_protocol); i++)
     {
       if (lm->local_next_by_ip_protocol[i] != IP_LOCAL_NEXT_PUNT)
-       vlib_cli_output (vm, "%d", i);
+       {
+         u32 node_index = vlib_get_node (vm,
+                                         ip4_local_node.index)->
+           next_nodes[lm->local_next_by_ip_protocol[i]];
+         vlib_cli_output (vm, "%d: %U", i, format_vlib_node_name, vm,
+                          node_index);
+       }
     }
   return 0;
 }
@@ -2043,7 +1987,7 @@ ip4_arp_inline (vlib_main_t * vm,
          p0 = vlib_get_buffer (vm, pi0);
 
          adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
-         adj0 = ip_get_adjacency (lm, adj_index0);
+         adj0 = adj_get (adj_index0);
          ip0 = vlib_buffer_get_current (p0);
 
          a0 = hash_seeds[0];
@@ -2067,11 +2011,12 @@ ip4_arp_inline (vlib_main_t * vm,
            }
          b0 ^= sw_if_index0;
 
+         hash_v3_mix32 (a0, b0, c0);
          hash_v3_finalize32 (a0, b0, c0);
 
          c0 &= BITS (hash_bitmap) - 1;
-         c0 = c0 / BITS (uword);
          m0 = (uword) 1 << (c0 % BITS (uword));
+         c0 = c0 / BITS (uword);
 
          bm0 = hash_bitmap[c0];
          drop0 = (bm0 & m0) != 0;
@@ -2121,6 +2066,10 @@ ip4_arp_inline (vlib_main_t * vm,
                                                 &im->ip4_arp_request_packet_template,
                                                 &bi0);
 
+             /* Seems we're out of buffers */
+             if (PREDICT_FALSE (!h0))
+               continue;
+
              /* Add rewrite/encap string for ARP packet. */
              vnet_rewrite_one_header (adj0[0], h0,
                                       sizeof (ethernet_header_t));
@@ -2165,6 +2114,7 @@ ip4_arp_inline (vlib_main_t * vm,
 
              vlib_buffer_copy_trace_flag (vm, p0, bi0);
              b0 = vlib_get_buffer (vm, bi0);
+             VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
              vnet_buffer (b0)->sw_if_index[VLIB_TX] = sw_if_index0;
 
              vlib_buffer_advance (b0, -adj0->rewrite_header.data_bytes);
@@ -2202,25 +2152,36 @@ static char *ip4_arp_error_strings[] = {
   [IP4_ARP_ERROR_NO_SOURCE_ADDRESS] = "no source address for ARP request",
 };
 
+/* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ip4_arp_node) =
 {
-  .function = ip4_arp,.name = "ip4-arp",.vector_size =
-    sizeof (u32),.format_trace = format_ip4_forward_next_trace,.n_errors =
-    ARRAY_LEN (ip4_arp_error_strings),.error_strings =
-    ip4_arp_error_strings,.n_next_nodes = IP4_ARP_N_NEXT,.next_nodes =
+  .function = ip4_arp,
+  .name = "ip4-arp",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ip4_forward_next_trace,
+  .n_errors = ARRAY_LEN (ip4_arp_error_strings),
+  .error_strings = ip4_arp_error_strings,
+  .n_next_nodes = IP4_ARP_N_NEXT,
+  .next_nodes =
   {
-  [IP4_ARP_NEXT_DROP] = "error-drop",}
-,};
+    [IP4_ARP_NEXT_DROP] = "error-drop",
+  },
+};
 
 VLIB_REGISTER_NODE (ip4_glean_node) =
 {
-  .function = ip4_glean,.name = "ip4-glean",.vector_size =
-    sizeof (u32),.format_trace = format_ip4_forward_next_trace,.n_errors =
-    ARRAY_LEN (ip4_arp_error_strings),.error_strings =
-    ip4_arp_error_strings,.n_next_nodes = IP4_ARP_N_NEXT,.next_nodes =
-  {
-  [IP4_ARP_NEXT_DROP] = "error-drop",}
-,};
+  .function = ip4_glean,
+  .name = "ip4-glean",
+  .vector_size = sizeof (u32),
+  .format_trace = format_ip4_forward_next_trace,
+  .n_errors = ARRAY_LEN (ip4_arp_error_strings),
+  .error_strings = ip4_arp_error_strings,
+  .n_next_nodes = IP4_ARP_N_NEXT,
+  .next_nodes = {
+  [IP4_ARP_NEXT_DROP] = "error-drop",
+  },
+};
+/* *INDENT-ON* */
 
 #define foreach_notrace_ip4_arp_error           \
 _(DROP)                                         \
@@ -2259,6 +2220,7 @@ ip4_probe_neighbor (vlib_main_t * vm, ip4_address_t * dst, u32 sw_if_index)
   vnet_hw_interface_t *hi;
   vnet_sw_interface_t *si;
   vlib_buffer_t *b;
+  adj_index_t ai;
   u32 bi = 0;
 
   si = vnet_get_sw_interface (vnm, sw_if_index);
@@ -2283,14 +2245,18 @@ ip4_probe_neighbor (vlib_main_t * vm, ip4_address_t * dst, u32 sw_if_index)
         sw_if_index);
     }
 
-  adj = ip_get_adjacency (&im->lookup_main, ia->neighbor_probe_adj_index);
-
-  h =
-    vlib_packet_template_get_packet (vm,
-                                    &im->ip4_arp_request_packet_template,
-                                    &bi);
+  h = vlib_packet_template_get_packet (vm,
+                                      &im->ip4_arp_request_packet_template,
+                                      &bi);
 
   hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
+  if (PREDICT_FALSE (!hi->hw_address))
+    {
+      return clib_error_return (0, "%U: interface %U do not support ip probe",
+                               format_ip4_address, dst,
+                               format_vnet_sw_if_index_name, vnm,
+                               sw_if_index);
+    }
 
   clib_memcpy (h->ip4_over_ethernet[0].ethernet, hi->hw_address,
               sizeof (h->ip4_over_ethernet[0].ethernet));
@@ -2302,6 +2268,22 @@ ip4_probe_neighbor (vlib_main_t * vm, ip4_address_t * dst, u32 sw_if_index)
   vnet_buffer (b)->sw_if_index[VLIB_RX] =
     vnet_buffer (b)->sw_if_index[VLIB_TX] = sw_if_index;
 
+  ip46_address_t nh = {
+    .ip4 = *dst,
+  };
+
+  ai = adj_nbr_add_or_lock (FIB_PROTOCOL_IP4,
+                           VNET_LINK_IP4, &nh, sw_if_index);
+  adj = adj_get (ai);
+
+  /* Peer has been previously resolved, retrieve glean adj instead */
+  if (adj->lookup_next_index == IP_LOOKUP_NEXT_REWRITE)
+    {
+      adj_unlock (ai);
+      ai = adj_glean_add_or_lock (FIB_PROTOCOL_IP4, sw_if_index, &nh);
+      adj = adj_get (ai);
+    }
+
   /* Add encapsulation string for software interface (e.g. ethernet header). */
   vnet_rewrite_one_header (adj[0], h, sizeof (ethernet_header_t));
   vlib_buffer_advance (b, -adj->rewrite_header.data_bytes);
@@ -2314,6 +2296,7 @@ ip4_probe_neighbor (vlib_main_t * vm, ip4_address_t * dst, u32 sw_if_index)
     vlib_put_frame_to_node (vm, hi->output_node_index, f);
   }
 
+  adj_unlock (ai);
   return /* no error */ 0;
 }
 
@@ -2337,7 +2320,7 @@ ip4_rewrite_inline (vlib_main_t * vm,
 
   n_left_from = frame->n_vectors;
   next_index = node->cached_next_index;
-  u32 cpu_index = os_get_cpu_number ();
+  u32 thread_index = vlib_get_thread_index ();
 
   while (n_left_from > 0)
     {
@@ -2380,8 +2363,16 @@ ip4_rewrite_inline (vlib_main_t * vm,
          adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
          adj_index1 = vnet_buffer (p1)->ip.adj_index[VLIB_TX];
 
-         /* We should never rewrite a pkt using the MISS adjacency */
-         ASSERT (adj_index0 && adj_index1);
+         /*
+          * pre-fetch the per-adjacency counters
+          */
+         if (do_counters)
+           {
+             vlib_prefetch_combined_counter (&adjacency_counters,
+                                             thread_index, adj_index0);
+             vlib_prefetch_combined_counter (&adjacency_counters,
+                                             thread_index, adj_index1);
+           }
 
          ip0 = vlib_buffer_get_current (p0);
          ip1 = vlib_buffer_get_current (p1);
@@ -2391,7 +2382,7 @@ ip4_rewrite_inline (vlib_main_t * vm,
 
          /* Decrement TTL & update checksum.
             Works either endian, so no need for byte swap. */
-         if (PREDICT_TRUE (!(p0->flags & VNET_BUFFER_LOCALLY_ORIGINATED)))
+         if (PREDICT_TRUE (!(p0->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED)))
            {
              i32 ttl0 = ip0->ttl;
 
@@ -2420,13 +2411,14 @@ ip4_rewrite_inline (vlib_main_t * vm,
                }
 
              /* Verify checksum. */
-             ASSERT (ip0->checksum == ip4_header_checksum (ip0));
+             ASSERT ((ip0->checksum == ip4_header_checksum (ip0)) ||
+                     (p0->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM));
            }
          else
            {
-             p0->flags &= ~VNET_BUFFER_LOCALLY_ORIGINATED;
+             p0->flags &= ~VNET_BUFFER_F_LOCALLY_ORIGINATED;
            }
-         if (PREDICT_TRUE (!(p1->flags & VNET_BUFFER_LOCALLY_ORIGINATED)))
+         if (PREDICT_TRUE (!(p1->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED)))
            {
              i32 ttl1 = ip1->ttl;
 
@@ -2455,17 +2447,17 @@ ip4_rewrite_inline (vlib_main_t * vm,
                }
 
              /* Verify checksum. */
-             ASSERT (ip0->checksum == ip4_header_checksum (ip0));
-             ASSERT (ip1->checksum == ip4_header_checksum (ip1));
+             ASSERT ((ip1->checksum == ip4_header_checksum (ip1)) ||
+                     (p1->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM));
            }
          else
            {
-             p1->flags &= ~VNET_BUFFER_LOCALLY_ORIGINATED;
+             p1->flags &= ~VNET_BUFFER_F_LOCALLY_ORIGINATED;
            }
 
          /* Rewrite packet header and updates lengths. */
-         adj0 = ip_get_adjacency (lm, adj_index0);
-         adj1 = ip_get_adjacency (lm, adj_index1);
+         adj0 = adj_get (adj_index0);
+         adj1 = adj_get (adj_index1);
 
          /* Worth pipelining. No guarantee that adj0,1 are hot... */
          rw_len0 = adj0[0].rewrite_header.data_bytes;
@@ -2485,15 +2477,14 @@ ip4_rewrite_inline (vlib_main_t * vm,
             rewrite_header.max_l3_packet_bytes ? IP4_ERROR_MTU_EXCEEDED :
             error1);
 
-         /*
-          * pre-fetch the per-adjacency counters
-          */
-         if (do_counters)
+         if (is_mcast)
            {
-             vlib_prefetch_combined_counter (&adjacency_counters,
-                                             cpu_index, adj_index0);
-             vlib_prefetch_combined_counter (&adjacency_counters,
-                                             cpu_index, adj_index1);
+             error0 = ((adj0[0].rewrite_header.sw_if_index ==
+                        vnet_buffer (p0)->sw_if_index[VLIB_RX]) ?
+                       IP4_ERROR_SAME_INTERFACE : error0);
+             error1 = ((adj1[0].rewrite_header.sw_if_index ==
+                        vnet_buffer (p1)->sw_if_index[VLIB_RX]) ?
+                       IP4_ERROR_SAME_INTERFACE : error1);
            }
 
          /* Don't adjust the buffer for ttl issue; icmp-error node wants
@@ -2506,8 +2497,10 @@ ip4_rewrite_inline (vlib_main_t * vm,
              tx_sw_if_index0 = adj0[0].rewrite_header.sw_if_index;
              vnet_buffer (p0)->sw_if_index[VLIB_TX] = tx_sw_if_index0;
 
-             vnet_feature_arc_start (lm->output_feature_arc_index,
-                                     tx_sw_if_index0, &next0, p0);
+             if (PREDICT_FALSE
+                 (adj0[0].rewrite_header.flags & VNET_REWRITE_HAS_FEATURES))
+               vnet_feature_arc_start (lm->output_feature_arc_index,
+                                       tx_sw_if_index0, &next0, p0);
            }
          if (PREDICT_TRUE (error1 == IP4_ERROR_NONE))
            {
@@ -2518,8 +2511,10 @@ ip4_rewrite_inline (vlib_main_t * vm,
              tx_sw_if_index1 = adj1[0].rewrite_header.sw_if_index;
              vnet_buffer (p1)->sw_if_index[VLIB_TX] = tx_sw_if_index1;
 
-             vnet_feature_arc_start (lm->output_feature_arc_index,
-                                     tx_sw_if_index1, &next1, p1);
+             if (PREDICT_FALSE
+                 (adj1[0].rewrite_header.flags & VNET_REWRITE_HAS_FEATURES))
+               vnet_feature_arc_start (lm->output_feature_arc_index,
+                                       tx_sw_if_index1, &next1, p1);
            }
 
          /* Guess we are only writing on simple Ethernet header. */
@@ -2533,13 +2528,13 @@ ip4_rewrite_inline (vlib_main_t * vm,
            {
              vlib_increment_combined_counter
                (&adjacency_counters,
-                cpu_index,
+                thread_index,
                 adj_index0, 1,
                 vlib_buffer_length_in_chain (vm, p0) + rw_len0);
 
              vlib_increment_combined_counter
                (&adjacency_counters,
-                cpu_index,
+                thread_index,
                 adj_index1, 1,
                 vlib_buffer_length_in_chain (vm, p1) + rw_len1);
            }
@@ -2554,8 +2549,8 @@ ip4_rewrite_inline (vlib_main_t * vm,
              /*
               * copy bytes from the IP address into the MAC rewrite
               */
-             vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0, 1);
-             vnet_fixup_one_header (adj1[0], &ip1->dst_address, ip1, 1);
+             vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0);
+             vnet_fixup_one_header (adj1[0], &ip1->dst_address, ip1);
            }
 
          vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
@@ -2577,10 +2572,7 @@ ip4_rewrite_inline (vlib_main_t * vm,
 
          adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
 
-         /* We should never rewrite a pkt using the MISS adjacency */
-         ASSERT (adj_index0);
-
-         adj0 = ip_get_adjacency (lm, adj_index0);
+         adj0 = adj_get (adj_index0);
 
          ip0 = vlib_buffer_get_current (p0);
 
@@ -2588,7 +2580,7 @@ ip4_rewrite_inline (vlib_main_t * vm,
          next0 = IP4_REWRITE_NEXT_DROP;        /* drop on error */
 
          /* Decrement TTL & update checksum. */
-         if (PREDICT_TRUE (!(p0->flags & VNET_BUFFER_LOCALLY_ORIGINATED)))
+         if (PREDICT_TRUE (!(p0->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED)))
            {
              i32 ttl0 = ip0->ttl;
 
@@ -2604,7 +2596,8 @@ ip4_rewrite_inline (vlib_main_t * vm,
 
              ip0->ttl = ttl0;
 
-             ASSERT (ip0->checksum == ip4_header_checksum (ip0));
+             ASSERT ((ip0->checksum == ip4_header_checksum (ip0)) ||
+                     (p0->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM));
 
              if (PREDICT_FALSE (ttl0 <= 0))
                {
@@ -2622,11 +2615,12 @@ ip4_rewrite_inline (vlib_main_t * vm,
            }
          else
            {
-             p0->flags &= ~VNET_BUFFER_LOCALLY_ORIGINATED;
+             p0->flags &= ~VNET_BUFFER_F_LOCALLY_ORIGINATED;
            }
 
-         vlib_prefetch_combined_counter (&adjacency_counters,
-                                         cpu_index, adj_index0);
+         if (do_counters)
+           vlib_prefetch_combined_counter (&adjacency_counters,
+                                           thread_index, adj_index0);
 
          /* Guess we are only writing on simple Ethernet header. */
          vnet_rewrite_one_header (adj0[0], ip0, sizeof (ethernet_header_t));
@@ -2635,23 +2629,29 @@ ip4_rewrite_inline (vlib_main_t * vm,
              /*
               * copy bytes from the IP address into the MAC rewrite
               */
-             vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0, 1);
+             vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0);
            }
 
          /* Update packet buffer attributes/set output interface. */
          rw_len0 = adj0[0].rewrite_header.data_bytes;
          vnet_buffer (p0)->ip.save_rewrite_length = rw_len0;
 
-         vlib_increment_combined_counter
-           (&adjacency_counters,
-            cpu_index,
-            adj_index0, 1, vlib_buffer_length_in_chain (vm, p0) + rw_len0);
+         if (do_counters)
+           vlib_increment_combined_counter
+             (&adjacency_counters,
+              thread_index, adj_index0, 1,
+              vlib_buffer_length_in_chain (vm, p0) + rw_len0);
 
          /* Check MTU of outgoing interface. */
          error0 = (vlib_buffer_length_in_chain (vm, p0)
                    > adj0[0].rewrite_header.max_l3_packet_bytes
                    ? IP4_ERROR_MTU_EXCEEDED : error0);
-
+         if (is_mcast)
+           {
+             error0 = ((adj0[0].rewrite_header.sw_if_index ==
+                        vnet_buffer (p0)->sw_if_index[VLIB_RX]) ?
+                       IP4_ERROR_SAME_INTERFACE : error0);
+           }
          p0->error = error_node->errors[error0];
 
          /* Don't adjust the buffer for ttl issue; icmp-error node wants
@@ -2670,8 +2670,10 @@ ip4_rewrite_inline (vlib_main_t * vm,
                  adj0->sub_type.midchain.fixup_func (vm, adj0, p0);
                }
 
-             vnet_feature_arc_start (lm->output_feature_arc_index,
-                                     tx_sw_if_index0, &next0, p0);
+             if (PREDICT_FALSE
+                 (adj0[0].rewrite_header.flags & VNET_REWRITE_HAS_FEATURES))
+               vnet_feature_arc_start (lm->output_feature_arc_index,
+                                       tx_sw_if_index0, &next0, p0);
 
            }
 
@@ -2725,7 +2727,7 @@ ip4_rewrite_inline (vlib_main_t * vm,
 
     <em>Next Indices:</em>
     - <code> adj->rewrite_header.next_index </code>
-      or @c error-drop
+      or @c ip4-drop
 */
 static uword
 ip4_rewrite (vlib_main_t * vm,
@@ -2757,6 +2759,16 @@ ip4_rewrite_mcast (vlib_main_t * vm,
     return ip4_rewrite_inline (vm, node, frame, 0, 0, 1);
 }
 
+static uword
+ip4_mcast_midchain (vlib_main_t * vm,
+                   vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  if (adj_are_counters_enabled ())
+    return ip4_rewrite_inline (vm, node, frame, 1, 1, 1);
+  else
+    return ip4_rewrite_inline (vm, node, frame, 0, 1, 1);
+}
+
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ip4_rewrite_node) = {
   .function = ip4_rewrite,
@@ -2767,7 +2779,7 @@ VLIB_REGISTER_NODE (ip4_rewrite_node) = {
 
   .n_next_nodes = 2,
   .next_nodes = {
-    [IP4_REWRITE_NEXT_DROP] = "error-drop",
+    [IP4_REWRITE_NEXT_DROP] = "ip4-drop",
     [IP4_REWRITE_NEXT_ICMP_ERROR] = "ip4-icmp-error",
   },
 };
@@ -2783,6 +2795,16 @@ VLIB_REGISTER_NODE (ip4_rewrite_mcast_node) = {
 };
 VLIB_NODE_FUNCTION_MULTIARCH (ip4_rewrite_mcast_node, ip4_rewrite_mcast)
 
+VLIB_REGISTER_NODE (ip4_mcast_midchain_node, static) = {
+  .function = ip4_mcast_midchain,
+  .name = "ip4-mcast-midchain",
+  .vector_size = sizeof (u32),
+
+  .format_trace = format_ip4_rewrite_trace,
+  .sibling_of = "ip4-rewrite",
+};
+VLIB_NODE_FUNCTION_MULTIARCH (ip4_mcast_midchain_node, ip4_mcast_midchain)
+
 VLIB_REGISTER_NODE (ip4_midchain_node) = {
   .function = ip4_midchain,
   .name = "ip4-midchain",
@@ -2793,101 +2815,6 @@ VLIB_REGISTER_NODE (ip4_midchain_node) = {
 VLIB_NODE_FUNCTION_MULTIARCH (ip4_midchain_node, ip4_midchain);
 /* *INDENT-ON */
 
-static clib_error_t *
-add_del_interface_table (vlib_main_t * vm,
-                        unformat_input_t * input, vlib_cli_command_t * cmd)
-{
-  vnet_main_t *vnm = vnet_get_main ();
-  ip_interface_address_t *ia;
-  clib_error_t *error = 0;
-  u32 sw_if_index, table_id;
-
-  sw_if_index = ~0;
-
-  if (!unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index))
-    {
-      error = clib_error_return (0, "unknown interface `%U'",
-                                format_unformat_error, input);
-      goto done;
-    }
-
-  if (unformat (input, "%d", &table_id))
-    ;
-  else
-    {
-      error = clib_error_return (0, "expected table id `%U'",
-                                format_unformat_error, input);
-      goto done;
-    }
-
-  /*
-   * If the interface already has in IP address, then a change int
-   * VRF is not allowed. The IP address applied must first be removed.
-   * We do not do that automatically here, since VPP has no knowledge
-   * of whether thoses subnets are valid in the destination VRF.
-   */
-  /* *INDENT-OFF* */
-  foreach_ip_interface_address (&ip4_main.lookup_main,
-                                ia, sw_if_index,
-                                1 /* honor unnumbered */,
-  ({
-      ip4_address_t * a;
-
-      a = ip_interface_address_get_address (&ip4_main.lookup_main, ia);
-      error = clib_error_return (0, "interface %U has address %U",
-                                 format_vnet_sw_if_index_name, vnm,
-                                 sw_if_index,
-                                 format_ip4_address, a);
-      goto done;
-   }));
-   /* *INDENT-ON* */
-
-{
-  ip4_main_t *im = &ip4_main;
-  u32 fib_index;
-
-  fib_index = fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, table_id);
-
-  vec_validate (im->fib_index_by_sw_if_index, sw_if_index);
-  im->fib_index_by_sw_if_index[sw_if_index] = fib_index;
-
-  fib_index = mfib_table_find_or_create_and_lock (FIB_PROTOCOL_IP4, table_id);
-  vec_validate (im->mfib_index_by_sw_if_index, sw_if_index);
-  im->mfib_index_by_sw_if_index[sw_if_index] = fib_index;
-}
-
-done:
-return error;
-}
-
-/*?
- * Place the indicated interface into the supplied IPv4 FIB table (also known
- * as a VRF). If the FIB table does not exist, this command creates it. To
- * display the current IPv4 FIB table, use the command '<em>show ip fib</em>'.
- * FIB table will only be displayed if a route has been added to the table, or
- * an IP Address is assigned to an interface in the table (which adds a route
- * automatically).
- *
- * @note IP addresses added after setting the interface IP table are added to
- * the indicated FIB table. If an IP address is added prior to changing the
- * table then this is an error. The control plane must remove these addresses
- * first and then change the table. VPP will not automatically move the
- * addresses from the old to the new table as it does not know the validity
- * of such a change.
- *
- * @cliexpar
- * Example of how to add an interface to an IPv4 FIB table (where 2 is the table-id):
- * @cliexcmd{set interface ip table GigabitEthernet2/0/0 2}
- ?*/
-/* *INDENT-OFF* */
-VLIB_CLI_COMMAND (set_interface_ip_table_command, static) =
-{
-  .path = "set interface ip table",
-  .function = add_del_interface_table,
-  .short_help = "set interface ip table <interface> <table-id>",
-};
-/* *INDENT-ON* */
-
 int
 ip4_lookup_validate (ip4_address_t * a, u32 fib_index0)
 {
@@ -2897,15 +2824,10 @@ ip4_lookup_validate (ip4_address_t * a, u32 fib_index0)
 
   mtrie0 = &ip4_fib_get (fib_index0)->mtrie;
 
-  leaf0 = IP4_FIB_MTRIE_LEAF_ROOT;
-  leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, a, 0);
-  leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, a, 1);
+  leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, a);
   leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, a, 2);
   leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, a, 3);
 
-  /* Handle default route. */
-  leaf0 = (leaf0 == IP4_FIB_MTRIE_LEAF_EMPTY ? mtrie0->default_leaf : leaf0);
-
   lbi0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
 
   return lbi0 == ip4_fib_table_lookup_lb (ip4_fib_get (fib_index0), a);
@@ -2993,16 +2915,16 @@ VLIB_CLI_COMMAND (lookup_test_command, static) =
 int
 vnet_set_ip4_flow_hash (u32 table_id, u32 flow_hash_config)
 {
-  ip4_main_t *im4 = &ip4_main;
-  ip4_fib_t *fib;
-  uword *p = hash_get (im4->fib_index_by_table_id, table_id);
+  u32 fib_index;
+
+  fib_index = fib_table_find (FIB_PROTOCOL_IP4, table_id);
 
-  if (p == 0)
+  if (~0 == fib_index)
     return VNET_API_ERROR_NO_SUCH_FIB;
 
-  fib = ip4_fib_get (p[0]);
+  fib_table_set_flow_hash_config (fib_index, FIB_PROTOCOL_IP4,
+                                 flow_hash_config);
 
-  fib->flow_hash_config = flow_hash_config;
   return 0;
 }
 
@@ -3265,6 +3187,29 @@ VLIB_CLI_COMMAND (set_ip_classify_command, static) =
 };
 /* *INDENT-ON* */
 
+static clib_error_t *
+ip4_config (vlib_main_t * vm, unformat_input_t * input)
+{
+  ip4_main_t *im = &ip4_main;
+  uword heapsize = 0;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (input, "heap-size %U", unformat_memory_size, &heapsize))
+       ;
+      else
+       return clib_error_return (0,
+                                 "invalid heap-size parameter `%U'",
+                                 format_unformat_error, input);
+    }
+
+  im->mtrie_heap_size = heapsize;
+
+  return 0;
+}
+
+VLIB_EARLY_CONFIG_FUNCTION (ip4_config, "ip");
+
 /*
  * fd.io coding-style-patch-verification: ON
  *