ip: Fragmentation fixes
[vpp.git] / src / vnet / ip / ip4_forward.c
index f3819e3..1550b31 100644 (file)
 VLIB_NODE_FN (ip4_lookup_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
                                vlib_frame_t * frame)
 {
-  return ip4_lookup_inline (vm, node, frame,
-                           /* lookup_for_responses_to_locally_received_packets */
-                           0);
-
+  return ip4_lookup_inline (vm, node, frame);
 }
 
 static u8 *format_ip4_lookup_trace (u8 * s, va_list * args);
@@ -300,6 +297,7 @@ ip4_interface_first_address (ip4_main_t * im, u32 sw_if_index,
     *result_ia = result ? ia : 0;
   return result;
 }
+#endif
 
 static void
 ip4_add_subnet_bcast_route (u32 fib_index,
@@ -341,74 +339,122 @@ ip4_add_subnet_bcast_route (u32 fib_index,
 }
 
 static void
-ip4_add_interface_routes (u32 sw_if_index,
-                         ip4_main_t * im, u32 fib_index,
-                         ip_interface_address_t * a)
+ip4_add_interface_prefix_routes (ip4_main_t *im,
+                                u32 sw_if_index,
+                                u32 fib_index,
+                                ip_interface_address_t * a)
 {
   ip_lookup_main_t *lm = &im->lookup_main;
+  ip_interface_prefix_t *if_prefix;
   ip4_address_t *address = ip_interface_address_get_address (lm, a);
-  fib_prefix_t pfx = {
-    .fp_len = a->address_length,
+
+  ip_interface_prefix_key_t key = {
+    .prefix = {
+      .fp_len = a->address_length,
+      .fp_proto = FIB_PROTOCOL_IP4,
+      .fp_addr.ip4.as_u32 = address->as_u32 & im->fib_masks[a->address_length],
+    },
+    .sw_if_index = sw_if_index,
+  };
+
+  fib_prefix_t pfx_special = {
     .fp_proto = FIB_PROTOCOL_IP4,
-    .fp_addr.ip4 = *address,
   };
 
-  if (pfx.fp_len <= 30)
+  /* If prefix already set on interface, just increment ref count & return */
+  if_prefix = ip_get_interface_prefix (lm, &key);
+  if (if_prefix)
     {
-      /* 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
+      if_prefix->ref_count += 1;
+      return;
+    }
+
+  /* New prefix - allocate a pool entry, initialize it, add to the hash */
+  pool_get (lm->if_prefix_pool, if_prefix);
+  if_prefix->ref_count = 1;
+  if_prefix->src_ia_index = a - lm->if_address_pool;
+  clib_memcpy (&if_prefix->key, &key, sizeof (key));
+  mhash_set (&lm->prefix_to_if_prefix_index, &key,
+            if_prefix - lm->if_prefix_pool, 0 /* old value */);
+
+  /* length <= 30 - add glean, drop first address, maybe drop bcast address */
+  if (a->address_length <= 30)
+    {
+      pfx_special.fp_len = a->address_length;
+      pfx_special.fp_addr.ip4.as_u32 = address->as_u32;
+
+      /* set the glean route for the prefix */
+      fib_table_entry_update_one_path (fib_index, &pfx_special,
+                                      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
+                                       /* 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)
-        ip4_add_subnet_bcast_route(fib_index, &net_pfx, sw_if_index);
-    }
-  else if (pfx.fp_len == 31)
-    {
-      u32 mask = clib_host_to_net_u32(1);
-      fib_prefix_t net_pfx = pfx;
+      /* set a drop route for the base address of the prefix */
+      pfx_special.fp_len = 32;
+      pfx_special.fp_addr.ip4.as_u32 =
+       address->as_u32 & im->fib_masks[a->address_length];
 
-      net_pfx.fp_len = 32;
-      net_pfx.fp_addr.ip4.as_u32 ^= mask;
+      if (pfx_special.fp_addr.ip4.as_u32 != address->as_u32)
+       fib_table_entry_special_add (fib_index, &pfx_special,
+                                    FIB_SOURCE_INTERFACE,
+                                    (FIB_ENTRY_FLAG_DROP |
+                                     FIB_ENTRY_FLAG_LOOSE_URPF_EXEMPT));
 
-      /* 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
+      /* set a route for the broadcast address of the prefix */
+      pfx_special.fp_len = 32;
+      pfx_special.fp_addr.ip4.as_u32 =
+       address->as_u32 | ~im->fib_masks[a->address_length];
+      if (pfx_special.fp_addr.ip4.as_u32 != address->as_u32)
+       ip4_add_subnet_bcast_route (fib_index, &pfx_special, sw_if_index);
+
+
+    }
+  /* length == 31 - add an attached route for the other address */
+  else if (a->address_length == 31)
+    {
+      pfx_special.fp_len = 32;
+      pfx_special.fp_addr.ip4.as_u32 =
+       address->as_u32 ^ clib_host_to_net_u32(1);
+
+      fib_table_entry_update_one_path (fib_index, &pfx_special,
+                                      FIB_SOURCE_INTERFACE,
+                                      (FIB_ENTRY_FLAG_ATTACHED),
+                                      DPO_PROTO_IP4,
+                                      &pfx_special.fp_addr,
+                                      sw_if_index,
+                                       /* invalid FIB index */
                                        ~0,
                                        1,
                                        NULL,
                                        FIB_ROUTE_PATH_FLAG_NONE);
     }
-  pfx.fp_len = 32;
+}
+
+static void
+ip4_add_interface_routes (u32 sw_if_index,
+                         ip4_main_t * im, u32 fib_index,
+                         ip_interface_address_t * a)
+{
+  ip_lookup_main_t *lm = &im->lookup_main;
+  ip4_address_t *address = ip_interface_address_get_address (lm, a);
+  fib_prefix_t pfx = {
+    .fp_len = 32,
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_addr.ip4 = *address,
+  };
+
+  /* set special routes for the prefix if needed */
+  ip4_add_interface_prefix_routes (im, sw_if_index, fib_index, a);
 
   if (sw_if_index < vec_len (lm->classify_table_index_by_sw_if_index))
     {
@@ -445,49 +491,148 @@ ip4_add_interface_routes (u32 sw_if_index,
 }
 
 static void
-ip4_del_interface_routes (ip4_main_t * im,
-                         u32 fib_index,
-                         ip4_address_t * address, u32 address_length)
+ip4_del_interface_prefix_routes (ip4_main_t * im,
+                                u32 sw_if_index,
+                                u32 fib_index,
+                                ip4_address_t * address,
+                                u32 address_length)
 {
-  fib_prefix_t pfx = {
-    .fp_len = address_length,
+  ip_lookup_main_t *lm = &im->lookup_main;
+  ip_interface_prefix_t *if_prefix;
+
+  ip_interface_prefix_key_t key = {
+    .prefix = {
+      .fp_len = address_length,
+      .fp_proto = FIB_PROTOCOL_IP4,
+      .fp_addr.ip4.as_u32 = address->as_u32 & im->fib_masks[address_length],
+    },
+    .sw_if_index = sw_if_index,
+  };
+
+  fib_prefix_t pfx_special = {
+    .fp_len = 32,
     .fp_proto = FIB_PROTOCOL_IP4,
-    .fp_addr.ip4 = *address,
   };
 
-  if (pfx.fp_len <= 30)
+  if_prefix = ip_get_interface_prefix (lm, &key);
+  if (!if_prefix)
     {
-      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);
+      clib_warning ("Prefix not found while deleting %U",
+                   format_ip4_address_and_length, address, address_length);
+      return;
     }
-    else if (pfx.fp_len == 31)
+
+  if_prefix->ref_count -= 1;
+
+  /*
+   * Routes need to be adjusted if:
+   * - deleting last intf addr in prefix
+   * - deleting intf addr used as default source address in glean adjacency
+   *
+   * We're done now otherwise
+   */
+  if ((if_prefix->ref_count > 0) &&
+      !pool_is_free_index (lm->if_address_pool, if_prefix->src_ia_index))
+    return;
+
+  /* length <= 30, delete glean route, first address, last address */
+  if (address_length <= 30)
     {
-      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;
+      /* remove glean route for prefix */
+      pfx_special.fp_addr.ip4 = *address;
+      pfx_special.fp_len = address_length;
+      fib_table_entry_delete (fib_index, &pfx_special, FIB_SOURCE_INTERFACE);
+
+      /* if no more intf addresses in prefix, remove other special routes */
+      if (!if_prefix->ref_count)
+       {
+         /* first address in prefix */
+         pfx_special.fp_addr.ip4.as_u32 =
+           address->as_u32 & im->fib_masks[address_length];
+         pfx_special.fp_len = 32;
+
+         if (pfx_special.fp_addr.ip4.as_u32 != address->as_u32)
+         fib_table_entry_special_remove (fib_index,
+                                         &pfx_special,
+                                         FIB_SOURCE_INTERFACE);
+
+         /* prefix broadcast address */
+         pfx_special.fp_addr.ip4.as_u32 =
+           address->as_u32 | ~im->fib_masks[address_length];
+         pfx_special.fp_len = 32;
 
-      fib_table_entry_delete (fib_index, &net_pfx, FIB_SOURCE_INTERFACE);
+         if (pfx_special.fp_addr.ip4.as_u32 != address->as_u32)
+         fib_table_entry_special_remove (fib_index,
+                                         &pfx_special,
+                                         FIB_SOURCE_INTERFACE);
+       }
+      else
+       /* default source addr just got deleted, find another */
+       {
+         ip_interface_address_t *new_src_ia = NULL;
+         ip4_address_t *new_src_addr = NULL;
+
+         new_src_addr =
+           ip4_interface_address_matching_destination
+             (im, address, sw_if_index, &new_src_ia);
+
+         if_prefix->src_ia_index = new_src_ia - lm->if_address_pool;
+
+         pfx_special.fp_len = address_length;
+         pfx_special.fp_addr.ip4 = *new_src_addr;
+
+         /* set new glean route for the prefix */
+         fib_table_entry_update_one_path (fib_index, &pfx_special,
+                                          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);
+         return;
+       }
     }
+  /* length == 31, delete attached route for the other address */
+  else if (address_length == 31)
+    {
+      pfx_special.fp_addr.ip4.as_u32 =
+       address->as_u32 ^ clib_host_to_net_u32(1);
+
+      fib_table_entry_delete (fib_index, &pfx_special, FIB_SOURCE_INTERFACE);
+    }
+
+  mhash_unset (&lm->prefix_to_if_prefix_index, &key, 0 /* old_value */);
+  pool_put (lm->if_prefix_pool, if_prefix);
+}
+
+static void
+ip4_del_interface_routes (u32 sw_if_index,
+                         ip4_main_t * im,
+                         u32 fib_index,
+                         ip4_address_t * address, u32 address_length)
+{
+  fib_prefix_t pfx = {
+    .fp_len = address_length,
+    .fp_proto = FIB_PROTOCOL_IP4,
+    .fp_addr.ip4 = *address,
+  };
+
+  ip4_del_interface_prefix_routes (im, sw_if_index, fib_index,
+                                  address, address_length);
 
   pfx.fp_len = 32;
   fib_table_entry_delete (fib_index, &pfx, FIB_SOURCE_INTERFACE);
 }
 
+#ifndef CLIB_MARCH_VARIANT
 void
 ip4_sw_interface_enable_disable (u32 sw_if_index, u32 is_enable)
 {
@@ -515,6 +660,12 @@ ip4_sw_interface_enable_disable (u32 sw_if_index, u32 is_enable)
 
   vnet_feature_enable_disable ("ip4-multicast", "ip4-not-enabled",
                               sw_if_index, !is_enable, 0, 0);
+
+  {
+    ip4_enable_disable_interface_callback_t *cb;
+    vec_foreach (cb, im->enable_disable_interface_callbacks)
+      cb->function (im, cb->function_opaque, sw_if_index, is_enable);
+  }
 }
 
 static clib_error_t *
@@ -574,13 +725,22 @@ ip4_add_del_interface_address_internal (vlib_main_t * vm,
                                                       address,
                                                       address_length))
                      {
+                      /* an intf may have >1 addr from the same prefix */
+                      if ((sw_if_index == sif->sw_if_index) &&
+                          (ia->address_length == address_length) &&
+                          (x->as_u32 != address->as_u32))
+                        continue;
+
+                      /* error if the length or intf was different */
                        vnm->api_errno = VNET_API_ERROR_DUPLICATE_IF_ADDRESS;
 
                        return
                          clib_error_create
-                         ("failed to add %U which conflicts with %U for interface %U",
+                         ("failed to add %U on %U which conflicts with %U for interface %U",
                           format_ip4_address_and_length, address,
                           address_length,
+                         format_vnet_sw_if_index_name, vnm,
+                         sw_if_index,
                           format_ip4_address_and_length, x,
                           ia->address_length,
                           format_vnet_sw_if_index_name, vnm,
@@ -601,13 +761,19 @@ ip4_add_del_interface_address_internal (vlib_main_t * vm,
 
   ip4_sw_interface_enable_disable (sw_if_index, !is_del);
 
-  if (is_del)
-    ip4_del_interface_routes (im, ip4_af.fib_index, address, address_length);
-  else
-    ip4_add_interface_routes (sw_if_index,
-                             im, ip4_af.fib_index,
-                             pool_elt_at_index
-                             (lm->if_address_pool, if_address_index));
+  /* intf addr routes are added/deleted on admin up/down */
+  if (vnet_sw_interface_is_admin_up (vnm, sw_if_index))
+    {
+      if (is_del)
+       ip4_del_interface_routes (sw_if_index,
+                                 im, ip4_af.fib_index, address,
+                                 address_length);
+      else
+       ip4_add_interface_routes (sw_if_index,
+                                 im, ip4_af.fib_index,
+                                 pool_elt_at_index
+                                 (lm->if_address_pool, if_address_index));
+    }
 
   /* If pool did not grow/shrink: add duplicate address. */
   if (elts_before != pool_elts (lm->if_address_pool))
@@ -673,6 +839,46 @@ ip4_directed_broadcast (u32 sw_if_index, u8 enable)
 }
 #endif
 
+static clib_error_t *
+ip4_sw_interface_admin_up_down (vnet_main_t * vnm, u32 sw_if_index, u32 flags)
+{
+  ip4_main_t *im = &ip4_main;
+  ip_interface_address_t *ia;
+  ip4_address_t *a;
+  u32 is_admin_up, fib_index;
+
+  /* Fill in lookup tables with default table (0). */
+  vec_validate (im->fib_index_by_sw_if_index, sw_if_index);
+
+  vec_validate_init_empty (im->
+                          lookup_main.if_address_pool_index_by_sw_if_index,
+                          sw_if_index, ~0);
+
+  is_admin_up = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) != 0;
+
+  fib_index = vec_elt (im->fib_index_by_sw_if_index, sw_if_index);
+
+  /* *INDENT-OFF* */
+  foreach_ip_interface_address (&im->lookup_main, ia, sw_if_index,
+                                0 /* honor unnumbered */,
+  ({
+    a = ip_interface_address_get_address (&im->lookup_main, ia);
+    if (is_admin_up)
+      ip4_add_interface_routes (sw_if_index,
+                               im, fib_index,
+                               ia);
+    else
+      ip4_del_interface_routes (sw_if_index,
+                               im, fib_index,
+                               a, ia->address_length);
+  }));
+  /* *INDENT-ON* */
+
+  return 0;
+}
+
+VNET_SW_INTERFACE_ADMIN_UP_DOWN_FUNCTION (ip4_sw_interface_admin_up_down);
+
 /* Built-in ip4 unicast rx feature path definition */
 /* *INDENT-OFF* */
 VNET_FEATURE_ARC_INIT (ip4_unicast, static) =
@@ -997,7 +1203,7 @@ format_ip4_rewrite_trace (u8 * s, va_list * args)
   s = format (s, "\n%U%U",
              format_white_space, indent,
              format_ip_adjacency_packet_data,
-             t->dpo_index, t->packet_data, sizeof (t->packet_data));
+             t->packet_data, sizeof (t->packet_data));
   return s;
 }
 
@@ -1097,9 +1303,6 @@ 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, n_ip_bytes_this_buffer;
-  u16 sum16;
-  void *data_this_buffer;
 
   /* Initialize checksum with ip header. */
   ip_header_length = ip4_header_bytes (ip0);
@@ -1122,31 +1325,9 @@ ip4_tcp_udp_compute_checksum (vlib_main_t * vm, vlib_buffer_t * p0,
     sum0 =
       ip_csum_with_carry (sum0, clib_mem_unaligned (&ip0->src_address, u64));
 
-  n_bytes_left = n_this_buffer = payload_length_host_byte_order;
-  data_this_buffer = (void *) ip0 + ip_header_length;
-  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);
-      n_bytes_left -= n_this_buffer;
-      if (n_bytes_left == 0)
-       break;
-
-      ASSERT (p0->flags & VLIB_BUFFER_NEXT_PRESENT);
-      p0 = vlib_get_buffer (vm, p0->next_buffer);
-      data_this_buffer = vlib_buffer_get_current (p0);
-      n_this_buffer = clib_min (p0->current_length, n_bytes_left);
-    }
-
-  sum16 = ~ip_csum_fold (sum0);
-
-  return sum16;
+  return ip_calculate_l4_checksum (vm, p0, sum0,
+                                  payload_length_host_byte_order, (u8 *) ip0,
+                                  ip_header_length, NULL);
 }
 
 u32
@@ -1317,6 +1498,12 @@ ip4_local_check_src (vlib_buffer_t * b, ip4_header_t * ip0,
     vnet_buffer (b)->sw_if_index[VLIB_TX] != ~0 ?
     vnet_buffer (b)->sw_if_index[VLIB_TX] : vnet_buffer (b)->ip.fib_index;
 
+  /*
+   * vnet_buffer()->ip.adj_index[VLIB_RX] will be set to the index of the
+   *  adjacency for the destination address (the local interface address).
+   * vnet_buffer()->ip.adj_index[VLIB_TX] will be set to the index of the
+   *  adjacency for the source address (the remote sender's address)
+   */
   if (PREDICT_FALSE (last_check->first ||
                     (last_check->src.as_u32 != ip0->src_address.as_u32)))
     {
@@ -1326,8 +1513,9 @@ ip4_local_check_src (vlib_buffer_t * b, ip4_header_t * ip0,
       leaf0 = ip4_fib_mtrie_lookup_step (mtrie0, leaf0, &ip0->src_address, 3);
       lbi0 = ip4_fib_mtrie_leaf_get_adj_index (leaf0);
 
+      vnet_buffer (b)->ip.adj_index[VLIB_RX] =
+       vnet_buffer (b)->ip.adj_index[VLIB_TX];
       vnet_buffer (b)->ip.adj_index[VLIB_TX] = lbi0;
-      vnet_buffer (b)->ip.adj_index[VLIB_RX] = lbi0;
 
       lb0 = load_balance_get (lbi0);
       dpo0 = load_balance_get_bucket_i (lb0, 0);
@@ -1357,8 +1545,9 @@ ip4_local_check_src (vlib_buffer_t * b, ip4_header_t * ip0,
     }
   else
     {
+      vnet_buffer (b)->ip.adj_index[VLIB_RX] =
+       vnet_buffer (b)->ip.adj_index[VLIB_TX];
       vnet_buffer (b)->ip.adj_index[VLIB_TX] = last_check->lbi;
-      vnet_buffer (b)->ip.adj_index[VLIB_RX] = last_check->lbi;
       *error0 = last_check->error;
       last_check->first = 0;
     }
@@ -1389,6 +1578,12 @@ ip4_local_check_src_x2 (vlib_buffer_t ** b, ip4_header_t ** ip,
     vnet_buffer (b[1])->sw_if_index[VLIB_TX] :
     vnet_buffer (b[1])->ip.fib_index;
 
+  /*
+   * vnet_buffer()->ip.adj_index[VLIB_RX] will be set to the index of the
+   *  adjacency for the destination address (the local interface address).
+   * vnet_buffer()->ip.adj_index[VLIB_TX] will be set to the index of the
+   *  adjacency for the source address (the remote sender's address)
+   */
   if (PREDICT_FALSE (not_last_hit))
     {
       mtrie[0] = &ip4_fib_get (vnet_buffer (b[0])->ip.fib_index)->mtrie;
@@ -1410,11 +1605,13 @@ ip4_local_check_src_x2 (vlib_buffer_t ** b, ip4_header_t ** ip,
       lbi[0] = ip4_fib_mtrie_leaf_get_adj_index (leaf[0]);
       lbi[1] = ip4_fib_mtrie_leaf_get_adj_index (leaf[1]);
 
+      vnet_buffer (b[0])->ip.adj_index[VLIB_RX] =
+       vnet_buffer (b[0])->ip.adj_index[VLIB_TX];
       vnet_buffer (b[0])->ip.adj_index[VLIB_TX] = lbi[0];
-      vnet_buffer (b[0])->ip.adj_index[VLIB_RX] = lbi[0];
 
+      vnet_buffer (b[1])->ip.adj_index[VLIB_RX] =
+       vnet_buffer (b[1])->ip.adj_index[VLIB_TX];
       vnet_buffer (b[1])->ip.adj_index[VLIB_TX] = lbi[1];
-      vnet_buffer (b[1])->ip.adj_index[VLIB_RX] = lbi[1];
 
       lb[0] = load_balance_get (lbi[0]);
       lb[1] = load_balance_get (lbi[1]);
@@ -1444,11 +1641,13 @@ ip4_local_check_src_x2 (vlib_buffer_t ** b, ip4_header_t ** ip,
     }
   else
     {
+      vnet_buffer (b[0])->ip.adj_index[VLIB_RX] =
+       vnet_buffer (b[0])->ip.adj_index[VLIB_TX];
       vnet_buffer (b[0])->ip.adj_index[VLIB_TX] = last_check->lbi;
-      vnet_buffer (b[0])->ip.adj_index[VLIB_RX] = last_check->lbi;
 
+      vnet_buffer (b[1])->ip.adj_index[VLIB_RX] =
+       vnet_buffer (b[1])->ip.adj_index[VLIB_TX];
       vnet_buffer (b[1])->ip.adj_index[VLIB_TX] = last_check->lbi;
-      vnet_buffer (b[1])->ip.adj_index[VLIB_RX] = last_check->lbi;
 
       error[0] = last_check->error;
       error[1] = last_check->error;
@@ -1632,7 +1831,7 @@ VLIB_REGISTER_NODE (ip4_local_node) =
     [IP_LOCAL_NEXT_PUNT] = "ip4-punt",
     [IP_LOCAL_NEXT_UDP_LOOKUP] = "ip4-udp-lookup",
     [IP_LOCAL_NEXT_ICMP] = "ip4-icmp-input",
-    [IP_LOCAL_NEXT_REASSEMBLY] = "ip4-reassembly",
+    [IP_LOCAL_NEXT_REASSEMBLY] = "ip4-full-reassembly",
   },
 };
 /* *INDENT-ON* */
@@ -1673,6 +1872,16 @@ ip4_register_protocol (u32 protocol, u32 node_index)
   lm->local_next_by_ip_protocol[protocol] =
     vlib_node_add_next (vm, ip4_local_node.index, node_index);
 }
+
+void
+ip4_unregister_protocol (u32 protocol)
+{
+  ip4_main_t *im = &ip4_main;
+  ip_lookup_main_t *lm = &im->lookup_main;
+
+  ASSERT (protocol < ARRAY_LEN (lm->local_next_by_ip_protocol));
+  lm->local_next_by_ip_protocol[protocol] = IP_LOCAL_NEXT_PUNT;
+}
 #endif
 
 static clib_error_t *
@@ -1691,8 +1900,8 @@ show_ip_local_command_fn (vlib_main_t * vm,
          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);
+         vlib_cli_output (vm, "%U: %U", format_ip_protocol, i,
+                          format_vlib_node_name, vm, node_index);
        }
     }
   return 0;
@@ -1820,11 +2029,6 @@ ip4_arp_inline (vlib_main_t * vm,
            vlib_packet_template_get_packet (vm,
                                             &im->ip4_arp_request_packet_template,
                                             &bi0);
-         b0 = vlib_get_buffer (vm, bi0);
-
-         /* copy the persistent fields from the original */
-         clib_memcpy_fast (b0->opaque2, p0->opaque2, sizeof (p0->opaque2));
-
          /* Seems we're out of buffers */
          if (PREDICT_FALSE (!h0))
            {
@@ -1832,6 +2036,11 @@ ip4_arp_inline (vlib_main_t * vm,
              continue;
            }
 
+         b0 = vlib_get_buffer (vm, bi0);
+
+         /* copy the persistent fields from the original */
+         clib_memcpy_fast (b0->opaque2, p0->opaque2, sizeof (p0->opaque2));
+
          /* Add rewrite/encap string for ARP packet. */
          vnet_rewrite_one_header (adj0[0], h0, sizeof (ethernet_header_t));
 
@@ -2084,7 +2293,8 @@ typedef enum
 
 always_inline void
 ip4_mtu_check (vlib_buffer_t * b, u16 packet_len,
-              u16 adj_packet_bytes, bool df, u16 * next, u32 * error)
+              u16 adj_packet_bytes, bool df, u16 * next, u32 * error,
+              u8 is_midchain)
 {
   if (packet_len > adj_packet_bytes)
     {
@@ -2101,12 +2311,39 @@ ip4_mtu_check (vlib_buffer_t * b, u16 packet_len,
        {
          /* IP fragmentation */
          ip_frag_set_vnet_buffer (b, adj_packet_bytes,
-                                  IP4_FRAG_NEXT_IP4_REWRITE, 0);
+                                  (is_midchain ?
+                                   IP4_FRAG_NEXT_IP4_REWRITE_MIDCHAIN :
+                                   IP4_FRAG_NEXT_IP4_REWRITE), 0);
          *next = IP4_REWRITE_NEXT_FRAGMENT;
        }
     }
 }
 
+/* increment TTL & update checksum.
+   Works either endian, so no need for byte swap. */
+static_always_inline void
+ip4_ttl_inc (vlib_buffer_t * b, ip4_header_t * ip)
+{
+  i32 ttl;
+  u32 checksum;
+  if (PREDICT_FALSE (b->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED))
+    {
+      b->flags &= ~VNET_BUFFER_F_LOCALLY_ORIGINATED;
+      return;
+    }
+
+  ttl = ip->ttl;
+
+  checksum = ip->checksum - clib_host_to_net_u16 (0x0100);
+  checksum += checksum >= 0xffff;
+
+  ip->checksum = checksum;
+  ttl += 1;
+  ip->ttl = ttl;
+
+  ASSERT (ip->checksum == ip4_header_checksum (ip));
+}
+
 /* Decrement TTL & update checksum.
    Works either endian, so no need for byte swap. */
 static_always_inline void
@@ -2174,6 +2411,7 @@ ip4_rewrite_inline_with_gso (vlib_main_t * vm,
   vlib_get_buffers (vm, from, bufs, n_left_from);
   clib_memset_u16 (nexts, IP4_REWRITE_NEXT_DROP, n_left_from);
 
+#if (CLIB_N_PREFETCHES >= 8)
   if (n_left_from >= 6)
     {
       int i;
@@ -2248,12 +2486,12 @@ ip4_rewrite_inline_with_gso (vlib_main_t * vm,
                     adj0[0].rewrite_header.max_l3_packet_bytes,
                     ip0->flags_and_fragment_offset &
                     clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT),
-                    next + 0, &error0);
+                    next + 0, &error0, is_midchain);
       ip4_mtu_check (b[1], ip1_len,
                     adj1[0].rewrite_header.max_l3_packet_bytes,
                     ip1->flags_and_fragment_offset &
                     clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT),
-                    next + 1, &error1);
+                    next + 1, &error1, is_midchain);
 
       if (is_mcast)
        {
@@ -2270,8 +2508,8 @@ ip4_rewrite_inline_with_gso (vlib_main_t * vm,
       if (PREDICT_TRUE (error0 == IP4_ERROR_NONE))
        {
          u32 next_index = adj0[0].rewrite_header.next_index;
-         b[0]->current_data -= rw_len0;
-         b[0]->current_length += rw_len0;
+         vlib_buffer_advance (b[0], -(word) rw_len0);
+
          tx_sw_if_index0 = adj0[0].rewrite_header.sw_if_index;
          vnet_buffer (b[0])->sw_if_index[VLIB_TX] = tx_sw_if_index0;
 
@@ -2280,16 +2518,19 @@ ip4_rewrite_inline_with_gso (vlib_main_t * vm,
            vnet_feature_arc_start (lm->output_feature_arc_index,
                                    tx_sw_if_index0, &next_index, b[0]);
          next[0] = next_index;
+         if (is_midchain)
+           calc_checksums (vm, b[0]);
        }
       else
        {
          b[0]->error = error_node->errors[error0];
+         if (error0 == IP4_ERROR_MTU_EXCEEDED)
+           ip4_ttl_inc (b[0], ip0);
        }
       if (PREDICT_TRUE (error1 == IP4_ERROR_NONE))
        {
          u32 next_index = adj1[0].rewrite_header.next_index;
-         b[1]->current_data -= rw_len1;
-         b[1]->current_length += rw_len1;
+         vlib_buffer_advance (b[1], -(word) rw_len1);
 
          tx_sw_if_index1 = adj1[0].rewrite_header.sw_if_index;
          vnet_buffer (b[1])->sw_if_index[VLIB_TX] = tx_sw_if_index1;
@@ -2299,63 +2540,188 @@ ip4_rewrite_inline_with_gso (vlib_main_t * vm,
            vnet_feature_arc_start (lm->output_feature_arc_index,
                                    tx_sw_if_index1, &next_index, b[1]);
          next[1] = next_index;
+         if (is_midchain)
+           calc_checksums (vm, b[1]);
        }
       else
        {
          b[1]->error = error_node->errors[error1];
+         if (error1 == IP4_ERROR_MTU_EXCEEDED)
+           ip4_ttl_inc (b[1], ip1);
        }
-      if (is_midchain)
-       {
-         calc_checksums (vm, b[0]);
-         calc_checksums (vm, b[1]);
-       }
+
       /* Guess we are only writing on simple Ethernet header. */
       vnet_rewrite_two_headers (adj0[0], adj1[0],
                                ip0, ip1, sizeof (ethernet_header_t));
 
-      /*
-       * Bump the per-adjacency counters
-       */
       if (do_counters)
        {
-         vlib_increment_combined_counter
-           (&adjacency_counters,
-            thread_index,
-            adj_index0, 1, vlib_buffer_length_in_chain (vm, b[0]) + rw_len0);
-
-         vlib_increment_combined_counter
-           (&adjacency_counters,
-            thread_index,
-            adj_index1, 1, vlib_buffer_length_in_chain (vm, b[1]) + rw_len1);
+         if (error0 == IP4_ERROR_NONE)
+           vlib_increment_combined_counter
+             (&adjacency_counters,
+              thread_index,
+              adj_index0, 1,
+              vlib_buffer_length_in_chain (vm, b[0]) + rw_len0);
+
+         if (error1 == IP4_ERROR_NONE)
+           vlib_increment_combined_counter
+             (&adjacency_counters,
+              thread_index,
+              adj_index1, 1,
+              vlib_buffer_length_in_chain (vm, b[1]) + rw_len1);
        }
 
       if (is_midchain)
        {
-         if (adj0->sub_type.midchain.fixup_func)
+         if (error0 == IP4_ERROR_NONE && adj0->sub_type.midchain.fixup_func)
            adj0->sub_type.midchain.fixup_func
              (vm, adj0, b[0], adj0->sub_type.midchain.fixup_data);
-         if (adj1->sub_type.midchain.fixup_func)
+         if (error1 == IP4_ERROR_NONE && adj1->sub_type.midchain.fixup_func)
            adj1->sub_type.midchain.fixup_func
              (vm, adj1, b[1], adj1->sub_type.midchain.fixup_data);
        }
 
       if (is_mcast)
        {
-         /*
-          * copy bytes from the IP address into the MAC rewrite
-          */
-         vnet_ip_mcast_fixup_header (IP4_MCAST_ADDR_MASK,
-                                     adj0->rewrite_header.dst_mcast_offset,
-                                     &ip0->dst_address.as_u32, (u8 *) ip0);
-         vnet_ip_mcast_fixup_header (IP4_MCAST_ADDR_MASK,
-                                     adj1->rewrite_header.dst_mcast_offset,
-                                     &ip1->dst_address.as_u32, (u8 *) ip1);
+         /* copy bytes from the IP address into the MAC rewrite */
+         if (error0 == IP4_ERROR_NONE)
+           vnet_ip_mcast_fixup_header (IP4_MCAST_ADDR_MASK,
+                                       adj0->rewrite_header.dst_mcast_offset,
+                                       &ip0->dst_address.as_u32, (u8 *) ip0);
+         if (error1 == IP4_ERROR_NONE)
+           vnet_ip_mcast_fixup_header (IP4_MCAST_ADDR_MASK,
+                                       adj1->rewrite_header.dst_mcast_offset,
+                                       &ip1->dst_address.as_u32, (u8 *) ip1);
        }
 
       next += 2;
       b += 2;
       n_left_from -= 2;
     }
+#elif (CLIB_N_PREFETCHES >= 4)
+  next = nexts;
+  b = bufs;
+  while (n_left_from >= 1)
+    {
+      ip_adjacency_t *adj0;
+      ip4_header_t *ip0;
+      u32 rw_len0, error0, adj_index0;
+      u32 tx_sw_if_index0;
+      u8 *p;
+
+      /* Prefetch next iteration */
+      if (PREDICT_TRUE (n_left_from >= 4))
+       {
+         ip_adjacency_t *adj2;
+         u32 adj_index2;
+
+         vlib_prefetch_buffer_header (b[3], LOAD);
+         vlib_prefetch_buffer_data (b[2], LOAD);
+
+         /* Prefetch adj->rewrite_header */
+         adj_index2 = vnet_buffer (b[2])->ip.adj_index[VLIB_TX];
+         adj2 = adj_get (adj_index2);
+         p = (u8 *) adj2;
+         CLIB_PREFETCH (p + CLIB_CACHE_LINE_BYTES, CLIB_CACHE_LINE_BYTES,
+                        LOAD);
+       }
+
+      adj_index0 = vnet_buffer (b[0])->ip.adj_index[VLIB_TX];
+
+      /*
+       * Prefetch the per-adjacency counters
+       */
+      if (do_counters)
+       {
+         vlib_prefetch_combined_counter (&adjacency_counters,
+                                         thread_index, adj_index0);
+       }
+
+      ip0 = vlib_buffer_get_current (b[0]);
+
+      error0 = IP4_ERROR_NONE;
+
+      ip4_ttl_and_checksum_check (b[0], ip0, next + 0, &error0);
+
+      /* Rewrite packet header and updates lengths. */
+      adj0 = adj_get (adj_index0);
+
+      /* Rewrite header was prefetched. */
+      rw_len0 = adj0[0].rewrite_header.data_bytes;
+      vnet_buffer (b[0])->ip.save_rewrite_length = rw_len0;
+
+      /* Check MTU of outgoing interface. */
+      u16 ip0_len = clib_net_to_host_u16 (ip0->length);
+
+      if (do_gso && (b[0]->flags & VNET_BUFFER_F_GSO))
+       ip0_len = gso_mtu_sz (b[0]);
+
+      ip4_mtu_check (b[0], ip0_len,
+                    adj0[0].rewrite_header.max_l3_packet_bytes,
+                    ip0->flags_and_fragment_offset &
+                    clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT),
+                    next + 0, &error0, is_midchain);
+
+      if (is_mcast)
+       {
+         error0 = ((adj0[0].rewrite_header.sw_if_index ==
+                    vnet_buffer (b[0])->sw_if_index[VLIB_RX]) ?
+                   IP4_ERROR_SAME_INTERFACE : error0);
+       }
+
+      /* Don't adjust the buffer for ttl issue; icmp-error node wants
+       * to see the IP header */
+      if (PREDICT_TRUE (error0 == IP4_ERROR_NONE))
+       {
+         u32 next_index = adj0[0].rewrite_header.next_index;
+         vlib_buffer_advance (b[0], -(word) rw_len0);
+         tx_sw_if_index0 = adj0[0].rewrite_header.sw_if_index;
+         vnet_buffer (b[0])->sw_if_index[VLIB_TX] = tx_sw_if_index0;
+
+         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, &next_index, b[0]);
+         next[0] = next_index;
+
+         if (is_midchain)
+           calc_checksums (vm, b[0]);
+
+         /* Guess we are only writing on simple Ethernet header. */
+         vnet_rewrite_one_header (adj0[0], ip0, sizeof (ethernet_header_t));
+
+         /*
+          * Bump the per-adjacency counters
+          */
+         if (do_counters)
+           vlib_increment_combined_counter
+             (&adjacency_counters,
+              thread_index,
+              adj_index0, 1, vlib_buffer_length_in_chain (vm,
+                                                          b[0]) + rw_len0);
+
+         if (is_midchain && adj0->sub_type.midchain.fixup_func)
+           adj0->sub_type.midchain.fixup_func
+             (vm, adj0, b[0], adj0->sub_type.midchain.fixup_data);
+
+         if (is_mcast)
+           /* copy bytes from the IP address into the MAC rewrite */
+           vnet_ip_mcast_fixup_header (IP4_MCAST_ADDR_MASK,
+                                       adj0->rewrite_header.dst_mcast_offset,
+                                       &ip0->dst_address.as_u32, (u8 *) ip0);
+       }
+      else
+       {
+         b[0]->error = error_node->errors[error0];
+         if (error0 == IP4_ERROR_MTU_EXCEEDED)
+           ip4_ttl_inc (b[0], ip0);
+       }
+
+      next += 1;
+      b += 1;
+      n_left_from -= 1;
+    }
+#endif
 
   while (n_left_from > 0)
     {
@@ -2392,7 +2758,7 @@ ip4_rewrite_inline_with_gso (vlib_main_t * vm,
                     adj0[0].rewrite_header.max_l3_packet_bytes,
                     ip0->flags_and_fragment_offset &
                     clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT),
-                    next + 0, &error0);
+                    next + 0, &error0, is_midchain);
 
       if (is_mcast)
        {
@@ -2406,8 +2772,7 @@ ip4_rewrite_inline_with_gso (vlib_main_t * vm,
       if (PREDICT_TRUE (error0 == IP4_ERROR_NONE))
        {
          u32 next_index = adj0[0].rewrite_header.next_index;
-         b[0]->current_data -= rw_len0;
-         b[0]->current_length += rw_len0;
+         vlib_buffer_advance (b[0], -(word) rw_len0);
          tx_sw_if_index0 = adj0[0].rewrite_header.sw_if_index;
          vnet_buffer (b[0])->sw_if_index[VLIB_TX] = tx_sw_if_index0;
 
@@ -2416,39 +2781,36 @@ ip4_rewrite_inline_with_gso (vlib_main_t * vm,
            vnet_feature_arc_start (lm->output_feature_arc_index,
                                    tx_sw_if_index0, &next_index, b[0]);
          next[0] = next_index;
-       }
-      else
-       {
-         b[0]->error = error_node->errors[error0];
-       }
-      if (is_midchain)
-       {
-         calc_checksums (vm, b[0]);
-       }
-      /* Guess we are only writing on simple Ethernet header. */
-      vnet_rewrite_one_header (adj0[0], ip0, sizeof (ethernet_header_t));
 
-      if (do_counters)
-       vlib_increment_combined_counter
-         (&adjacency_counters,
-          thread_index, adj_index0, 1,
-          vlib_buffer_length_in_chain (vm, b[0]) + rw_len0);
+         if (is_midchain)
+           /* this acts on the packet that is about to be encapped */
+           calc_checksums (vm, b[0]);
 
-      if (is_midchain)
-       {
-         if (adj0->sub_type.midchain.fixup_func)
+         /* Guess we are only writing on simple Ethernet header. */
+         vnet_rewrite_one_header (adj0[0], ip0, sizeof (ethernet_header_t));
+
+         if (do_counters)
+           vlib_increment_combined_counter
+             (&adjacency_counters,
+              thread_index, adj_index0, 1,
+              vlib_buffer_length_in_chain (vm, b[0]) + rw_len0);
+
+         if (is_midchain && adj0->sub_type.midchain.fixup_func)
            adj0->sub_type.midchain.fixup_func
              (vm, adj0, b[0], adj0->sub_type.midchain.fixup_data);
-       }
 
-      if (is_mcast)
+         if (is_mcast)
+           /* copy bytes from the IP address into the MAC rewrite */
+           vnet_ip_mcast_fixup_header (IP4_MCAST_ADDR_MASK,
+                                       adj0->rewrite_header.dst_mcast_offset,
+                                       &ip0->dst_address.as_u32, (u8 *) ip0);
+       }
+      else
        {
-         /*
-          * copy bytes from the IP address into the MAC rewrite
-          */
-         vnet_ip_mcast_fixup_header (IP4_MCAST_ADDR_MASK,
-                                     adj0->rewrite_header.dst_mcast_offset,
-                                     &ip0->dst_address.as_u32, (u8 *) ip0);
+         b[0]->error = error_node->errors[error0];
+         /* undo the TTL decrement - we'll be back to do it again */
+         if (error0 == IP4_ERROR_MTU_EXCEEDED)
+           ip4_ttl_inc (b[0], ip0);
        }
 
       next += 1;
@@ -2606,8 +2968,8 @@ VLIB_REGISTER_NODE (ip4_mcast_midchain_node) = {
 VLIB_REGISTER_NODE (ip4_midchain_node) = {
   .name = "ip4-midchain",
   .vector_size = sizeof (u32),
-  .format_trace = format_ip4_forward_next_trace,
-  .sibling_of =  "ip4-rewrite",
+  .format_trace = format_ip4_rewrite_trace,
+  .sibling_of = "ip4-rewrite",
 };
 /* *INDENT-ON */