text: /*
   * Copyright (c) 2016 Cisco and/or its affiliates.
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at:
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  /*
   * ip/ip6_forward.c: IP v6 forwarding
   *
   * Copyright (c) 2008 Eliot Dresselhaus
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   *
   *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
   *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
   *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
   *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  
  #include <vnet/vnet.h>
  #include <vnet/ip/ip.h>
  #include <vnet/ip/ip_frag.h>
  #include <vnet/ip/ip6_link.h>
  #include <vnet/ethernet/ethernet.h>	/* for ethernet_header_t */
  #include <vnet/srp/srp.h>	/* for srp_hw_interface_class */
  #include <vppinfra/cache.h>
  #include <vnet/fib/fib_urpf_list.h>	/* for FIB uRPF check */
  #include <vnet/fib/ip6_fib.h>
  #include <vnet/mfib/ip6_mfib.h>
  #include <vnet/dpo/load_balance_map.h>
  #include <vnet/dpo/classify_dpo.h>
  #include <vnet/classify/vnet_classify.h>
  
  #ifndef CLIB_MARCH_VARIANT
  #include <vppinfra/bihash_template.c>
  #endif
  #include <vnet/ip/ip6_forward.h>
  #include <vnet/ipsec/ipsec_tun.h>
  #include <vnet/interface_output.h>
  
  /* Flag used by IOAM code. Classifier sets it pop-hop-by-hop checks it */
  #define OI_DECAP   0x80000000
  
  static void
  ip6_add_interface_prefix_routes (ip6_main_t * im,
  				 u32 sw_if_index,
  				 u32 fib_index,
  				 ip6_address_t * address, u32 address_length)
  {
    ip_lookup_main_t *lm = &im->lookup_main;
    ip_interface_prefix_t *if_prefix;
  
    /* *INDENT-OFF* */
    ip_interface_prefix_key_t key = {
      .prefix = {
        .fp_len = address_length,
        .fp_proto = FIB_PROTOCOL_IP6,
        .fp_addr.ip6 = {
          .as_u64 = {
            address->as_u64[0] & im->fib_masks[address_length].as_u64[0],
            address->as_u64[1] & im->fib_masks[address_length].as_u64[1],
          },
        },
      },
      .sw_if_index = sw_if_index,
    };
    /* *INDENT-ON* */
  
    /* If prefix already set on interface, just increment ref count & return */
    if_prefix = ip_get_interface_prefix (lm, &key);
    if (if_prefix)
      {
        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;
    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 < 128 - add glean */
    if (address_length < 128)
      {
        /* set the glean route for the prefix */
        fib_table_entry_update_one_path (fib_index, &key.prefix,
  				       FIB_SOURCE_INTERFACE,
  				       (FIB_ENTRY_FLAG_CONNECTED |
  					FIB_ENTRY_FLAG_ATTACHED),
  				       DPO_PROTO_IP6,
  				       /* No next-hop address */
  				       NULL, sw_if_index,
  				       /* invalid FIB index */
  				       ~0, 1,
  				       /* no out-label stack */
  				       NULL, FIB_ROUTE_PATH_FLAG_NONE);
      }
  }
  
  static void
  ip6_add_interface_routes (vnet_main_t * vnm, u32 sw_if_index,
  			  ip6_main_t * im, u32 fib_index,
  			  ip_interface_address_t * a)
  {
    ip_lookup_main_t *lm = &im->lookup_main;
    ip6_address_t *address = ip_interface_address_get_address (lm, a);
    fib_prefix_t pfx = {
      .fp_len = a->address_length,
      .fp_proto = FIB_PROTOCOL_IP6,
      .fp_addr.ip6 = *address,
    };
  
    /* set special routes for the prefix if needed */
    ip6_add_interface_prefix_routes (im, sw_if_index, fib_index,
  				   address, a->address_length);
  
    pfx.fp_len = 128;
    if (sw_if_index < vec_len (lm->classify_table_index_by_sw_if_index))
      {
        u32 classify_table_index =
  	lm->classify_table_index_by_sw_if_index[sw_if_index];
        if (classify_table_index != (u32) ~ 0)
  	{
  	  dpo_id_t dpo = DPO_INVALID;
  
  	  dpo_set (&dpo,
  		   DPO_CLASSIFY,
  		   DPO_PROTO_IP6,
  		   classify_dpo_create (DPO_PROTO_IP6, classify_table_index));
  
  	  fib_table_entry_special_dpo_add (fib_index,
  					   &pfx,
  					   FIB_SOURCE_CLASSIFY,
  					   FIB_ENTRY_FLAG_NONE, &dpo);
  	  dpo_reset (&dpo);
  	}
      }
  
    fib_table_entry_update_one_path (fib_index, &pfx,
  				   FIB_SOURCE_INTERFACE,
  				   (FIB_ENTRY_FLAG_CONNECTED |
  				    FIB_ENTRY_FLAG_LOCAL),
  				   DPO_PROTO_IP6,
  				   &pfx.fp_addr,
  				   sw_if_index, ~0,
  				   1, NULL, FIB_ROUTE_PATH_FLAG_NONE);
  }
  
  static void
  ip6_del_interface_prefix_routes (ip6_main_t * im,
  				 u32 sw_if_index,
  				 u32 fib_index,
  				 ip6_address_t * address, u32 address_length)
  {
    ip_lookup_main_t *lm = &im->lookup_main;
    ip_interface_prefix_t *if_prefix;
  
    /* *INDENT-OFF* */
    ip_interface_prefix_key_t key = {
      .prefix = {
        .fp_len = address_length,
        .fp_proto = FIB_PROTOCOL_IP6,
        .fp_addr.ip6 = {
          .as_u64 = {
            address->as_u64[0] & im->fib_masks[address_length].as_u64[0],
            address->as_u64[1] & im->fib_masks[address_length].as_u64[1],
          },
        },
      },
      .sw_if_index = sw_if_index,
    };
    /* *INDENT-ON* */
  
    if_prefix = ip_get_interface_prefix (lm, &key);
    if (!if_prefix)
      {
        clib_warning ("Prefix not found while deleting %U",
  		    format_ip4_address_and_length, address, address_length);
        return;
      }
  
    /* If not deleting last intf addr in prefix, decrement ref count & return */
    if_prefix->ref_count -= 1;
    if (if_prefix->ref_count > 0)
      return;
  
    /* length <= 128, delete glean route */
    if (address_length <= 128)
      {
        /* remove glean route for prefix */
        fib_table_entry_delete (fib_index, &key.prefix, 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
  ip6_del_interface_routes (u32 sw_if_index, ip6_main_t * im,
  			  u32 fib_index,
  			  ip6_address_t * address, u32 address_length)
  {
    fib_prefix_t pfx = {
      .fp_len = 128,
      .fp_proto = FIB_PROTOCOL_IP6,
      .fp_addr.ip6 = *address,
    };
  
    /* delete special routes for the prefix if needed */
    ip6_del_interface_prefix_routes (im, sw_if_index, fib_index,
  				   address, address_length);
  
    fib_table_entry_delete (fib_index, &pfx, FIB_SOURCE_INTERFACE);
  }
  
  #ifndef CLIB_MARCH_VARIANT
  void
  ip6_sw_interface_enable_disable (u32 sw_if_index, u32 is_enable)
  {
    ip6_main_t *im = &ip6_main;
    vnet_main_t *vnm = vnet_get_main ();
    vnet_hw_interface_t *hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
  
    vec_validate_init_empty (im->ip_enabled_by_sw_if_index, sw_if_index, 0);
  
    /*
     * enable/disable only on the 1<->0 transition
     */
    if (is_enable)
      {
        if (1 != ++im->ip_enabled_by_sw_if_index[sw_if_index])
  	return;
      }
    else
      {
        /* The ref count is 0 when an address is removed from an interface that has
         * no address - this is not a ciritical error */
        if (0 == im->ip_enabled_by_sw_if_index[sw_if_index] ||
  	  0 != --im->ip_enabled_by_sw_if_index[sw_if_index])
  	return;
      }
  
    vnet_feature_enable_disable ("ip6-unicast", "ip6-not-enabled", sw_if_index,
  			       !is_enable, 0, 0);
  
    vnet_feature_enable_disable ("ip6-multicast", "ip6-not-enabled",
  			       sw_if_index, !is_enable, 0, 0);
  
    if (is_enable)
      hi->l3_if_count++;
    else if (hi->l3_if_count)
      hi->l3_if_count--;
  }
  
  /* get first interface address */
  ip6_address_t *
  ip6_interface_first_address (ip6_main_t * im, u32 sw_if_index)
  {
    ip_lookup_main_t *lm = &im->lookup_main;
    ip_interface_address_t *ia = 0;
    ip6_address_t *result = 0;
  
    /* *INDENT-OFF* */
    foreach_ip_interface_address (lm, ia, sw_if_index,
                                  1 /* honor unnumbered */,
    ({
      ip6_address_t * a = ip_interface_address_get_address (lm, ia);
      result = a;
      break;
    }));
    /* *INDENT-ON* */
    return result;
  }
  
  clib_error_t *
  ip6_add_del_interface_address (vlib_main_t * vm,
  			       u32 sw_if_index,
  			       ip6_address_t * address,
  			       u32 address_length, u32 is_del)
  {
    vnet_main_t *vnm = vnet_get_main ();
    ip6_main_t *im = &ip6_main;
    ip_lookup_main_t *lm = &im->lookup_main;
    clib_error_t *error = NULL;
    u32 if_address_index;
    ip6_address_fib_t ip6_af, *addr_fib = 0;
    const ip6_address_t *ll_addr;
  
    /* local0 interface doesn't support IP addressing */
    if (sw_if_index == 0)
      {
        return
  	clib_error_create ("local0 interface doesn't support IP addressing");
      }
  
    if (ip6_address_is_link_local_unicast (address))
      {
        if (address_length != 128)
  	{
  	  vnm->api_errno = VNET_API_ERROR_ADDRESS_LENGTH_MISMATCH;
  	  return
  	    clib_error_create
  	    ("prefix length of link-local address must be 128");
  	}
        if (!is_del)
  	{
  	  int rv;
  
  	  rv = ip6_link_set_local_address (sw_if_index, address);
  
  	  if (rv)
  	    {
  	      vnm->api_errno = rv;
  	      return clib_error_create ("address not assignable");
  	    }
  	}
        else
  	{
  	  ll_addr = ip6_get_link_local_address (sw_if_index);
  	  if (ip6_address_is_equal (ll_addr, address))
  	    {
  	      vnm->api_errno = VNET_API_ERROR_ADDRESS_NOT_DELETABLE;
  	      return clib_error_create ("address not deletable");
  	    }
  	  else
  	    {
  	      vnm->api_errno = VNET_API_ERROR_ADDRESS_NOT_FOUND_FOR_INTERFACE;
  	      return clib_error_create ("address not found");
  	    }
  	}
  
        return (NULL);
      }
  
    vec_validate (im->fib_index_by_sw_if_index, sw_if_index);
    vec_validate (im->mfib_index_by_sw_if_index, sw_if_index);
  
    ip6_addr_fib_init (&ip6_af, address,
  		     vec_elt (im->fib_index_by_sw_if_index, sw_if_index));
    vec_add1 (addr_fib, ip6_af);
  
    /* *INDENT-OFF* */
    if (!is_del)
      {
        /* When adding an address check that it does not conflict
           with an existing address on any interface in this table. */
        ip_interface_address_t *ia;
        vnet_sw_interface_t *sif;
  
        pool_foreach(sif, vnm->interface_main.sw_interfaces,
        ({
            if (im->fib_index_by_sw_if_index[sw_if_index] ==
                im->fib_index_by_sw_if_index[sif->sw_if_index])
              {
                foreach_ip_interface_address
                  (&im->lookup_main, ia, sif->sw_if_index,
                   0 /* honor unnumbered */ ,
                   ({
                     ip6_address_t * x =
                       ip_interface_address_get_address
                       (&im->lookup_main, ia);
  
                     if (ip6_destination_matches_route
                         (im, address, x, ia->address_length) ||
                         ip6_destination_matches_route (im,
                                                        x,
                                                        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) &&
  			   !ip6_address_is_equal (x, address))
  		         continue;
  
                         if (ia->flags & IP_INTERFACE_ADDRESS_FLAG_STALE)
                           /* if the address we're comparing against is stale
                            * then the CP has not added this one back yet, maybe
                            * it never will, so we have to assume it won't and
                            * ignore it. if it does add it back, then it will fail
                            * because this one is now present */
                           continue;
  
  		       /* error if the length or intf was different */
                         vnm->api_errno = VNET_API_ERROR_DUPLICATE_IF_ADDRESS;
                         error =  clib_error_create
                           ("failed to add %U which conflicts with %U for interface %U",
                            format_ip6_address_and_length, address,
                            address_length,
                            format_ip6_address_and_length, x,
                            ia->address_length,
                            format_vnet_sw_if_index_name, vnm,
                            sif->sw_if_index);
                         goto done;
                       }
                   }));
              }
        }));
      }
    /* *INDENT-ON* */
  
    if_address_index = ip_interface_address_find (lm, addr_fib, address_length);
  
    if (is_del)
      {
        if (~0 == if_address_index)
  	{
  	  vnm->api_errno = VNET_API_ERROR_ADDRESS_NOT_FOUND_FOR_INTERFACE;
  	  error = clib_error_create ("%U not found for interface %U",
  				     lm->format_address_and_length,
  				     addr_fib, address_length,
  				     format_vnet_sw_if_index_name, vnm,
  				     sw_if_index);
  	  goto done;
  	}
  
        error = ip_interface_address_del (lm, vnm, if_address_index, addr_fib,
  					address_length, sw_if_index);
        if (error)
  	goto done;
      }
    else
      {
        if (~0 != if_address_index)
  	{
  	  ip_interface_address_t *ia;
  
  	  ia = pool_elt_at_index (lm->if_address_pool, if_address_index);
  
  	  if (ia->flags & IP_INTERFACE_ADDRESS_FLAG_STALE)
  	    {
  	      if (ia->sw_if_index == sw_if_index)
  		{
  		  /* re-adding an address during the replace action.
  		   * consdier this the update. clear the flag and
  		   * we're done */
  		  ia->flags &= ~IP_INTERFACE_ADDRESS_FLAG_STALE;
  		  goto done;
  		}
  	      else
  		{
  		  /* The prefix is moving from one interface to another.
  		   * delete the stale and add the new */
  		  ip6_add_del_interface_address (vm,
  						 ia->sw_if_index,
  						 address, address_length, 1);
  		  ia = NULL;
  		  error = ip_interface_address_add (lm, sw_if_index,
  						    addr_fib, address_length,
  						    &if_address_index);
  		}
  	    }
  	  else
  	    {
  	      vnm->api_errno = VNET_API_ERROR_DUPLICATE_IF_ADDRESS;
  	      error = clib_error_create
  		("Prefix %U already found on interface %U",
  		 lm->format_address_and_length, addr_fib, address_length,
  		 format_vnet_sw_if_index_name, vnm, ia->sw_if_index);
  	    }
  	}
        else
  	error = ip_interface_address_add (lm, sw_if_index,
  					  addr_fib, address_length,
  					  &if_address_index);
      }
  
    if (error)
      goto done;
  
    ip6_sw_interface_enable_disable (sw_if_index, !is_del);
    if (!is_del)
      ip6_link_enable (sw_if_index, NULL);
  
    /* intf addr routes are added/deleted on admin up/down */
    if (vnet_sw_interface_is_admin_up (vnm, sw_if_index))
      {
        if (is_del)
  	ip6_del_interface_routes (sw_if_index,
  				  im, ip6_af.fib_index, address,
  				  address_length);
        else
  	ip6_add_interface_routes (vnm, sw_if_index,
  				  im, ip6_af.fib_index,
  				  pool_elt_at_index (lm->if_address_pool,
  						     if_address_index));
      }
  
    ip6_add_del_interface_address_callback_t *cb;
    vec_foreach (cb, im->add_del_interface_address_callbacks)
      cb->function (im, cb->function_opaque, sw_if_index,
  		  address, address_length, if_address_index, is_del);
  
    if (is_del)
      ip6_link_disable (sw_if_index);
  
  done:
    vec_free (addr_fib);
    return error;
  }
  
  #endif
  
  static clib_error_t *
  ip6_sw_interface_admin_up_down (vnet_main_t * vnm, u32 sw_if_index, u32 flags)
  {
    ip6_main_t *im = &ip6_main;
    ip_interface_address_t *ia;
    ip6_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)
        ip6_add_interface_routes (vnm, sw_if_index,
  				im, fib_index,
  				ia);
      else
        ip6_del_interface_routes (sw_if_index, im, fib_index,
  				a, ia->address_length);
    }));
    /* *INDENT-ON* */
  
    return 0;
  }
  
  VNET_SW_INTERFACE_ADMIN_UP_DOWN_FUNCTION (ip6_sw_interface_admin_up_down);
  
  /* Built-in ip6 unicast rx feature path definition */
  /* *INDENT-OFF* */
  VNET_FEATURE_ARC_INIT (ip6_unicast, static) =
  {
    .arc_name  = "ip6-unicast",
    .start_nodes = VNET_FEATURES ("ip6-input"),
    .last_in_arc = "ip6-lookup",
    .arc_index_ptr = &ip6_main.lookup_main.ucast_feature_arc_index,
  };
  
  VNET_FEATURE_INIT (ip6_flow_classify, static) =
  {
    .arc_name = "ip6-unicast",
    .node_name = "ip6-flow-classify",
    .runs_before = VNET_FEATURES ("ip6-inacl"),
  };
  
  VNET_FEATURE_INIT (ip6_inacl, static) =
  {
    .arc_name = "ip6-unicast",
    .node_name = "ip6-inacl",
    .runs_before = VNET_FEATURES ("ip6-policer-classify"),
  };
  
  VNET_FEATURE_INIT (ip6_policer_classify, static) =
  {
    .arc_name = "ip6-unicast",
    .node_name = "ip6-policer-classify",
    .runs_before = VNET_FEATURES ("ipsec6-input-feature"),
  };
  
  VNET_FEATURE_INIT (ip6_ipsec, static) =
  {
    .arc_name = "ip6-unicast",
    .node_name = "ipsec6-input-feature",
    .runs_before = VNET_FEATURES ("l2tp-decap"),
  };
  
  VNET_FEATURE_INIT (ip6_l2tp, static) =
  {
    .arc_name = "ip6-unicast",
    .node_name = "l2tp-decap",
    .runs_before = VNET_FEATURES ("vpath-input-ip6"),
  };
  
  VNET_FEATURE_INIT (ip6_vpath, static) =
  {
    .arc_name = "ip6-unicast",
    .node_name = "vpath-input-ip6",
    .runs_before = VNET_FEATURES ("ip6-vxlan-bypass"),
  };
  
  VNET_FEATURE_INIT (ip6_vxlan_bypass, static) =
  {
    .arc_name = "ip6-unicast",
    .node_name = "ip6-vxlan-bypass",
    .runs_before = VNET_FEATURES ("ip6-lookup"),
  };
  
  VNET_FEATURE_INIT (ip6_not_enabled, static) =
  {
    .arc_name = "ip6-unicast",
    .node_name = "ip6-not-enabled",
    .runs_before = VNET_FEATURES ("ip6-lookup"),
  };
  
  VNET_FEATURE_INIT (ip6_lookup, static) =
  {
    .arc_name = "ip6-unicast",
    .node_name = "ip6-lookup",
    .runs_before = 0,  /*last feature*/
  };
  
  /* Built-in ip6 multicast rx feature path definition (none now) */
  VNET_FEATURE_ARC_INIT (ip6_multicast, static) =
  {
    .arc_name  = "ip6-multicast",
    .start_nodes = VNET_FEATURES ("ip6-input"),
    .last_in_arc = "ip6-mfib-forward-lookup",
    .arc_index_ptr = &ip6_main.lookup_main.mcast_feature_arc_index,
  };
  
  VNET_FEATURE_INIT (ip6_vpath_mc, static) = {
    .arc_name = "ip6-multicast",
    .node_name = "vpath-input-ip6",
    .runs_before = VNET_FEATURES ("ip6-mfib-forward-lookup"),
  };
  
  VNET_FEATURE_INIT (ip6_not_enabled_mc, static) = {
    .arc_name = "ip6-multicast",
    .node_name = "ip6-not-enabled",
    .runs_before = VNET_FEATURES ("ip6-mfib-forward-lookup"),
  };
  
  VNET_FEATURE_INIT (ip6_mc_lookup, static) = {
    .arc_name = "ip6-multicast",
    .node_name = "ip6-mfib-forward-lookup",
    .runs_before = 0, /* last feature */
  };
  
  /* Built-in ip4 tx feature path definition */
  VNET_FEATURE_ARC_INIT (ip6_output, static) =
  {
    .arc_name  = "ip6-output",
    .start_nodes = VNET_FEATURES ("ip6-rewrite", "ip6-midchain", "ip6-dvr-dpo"),
    .last_in_arc = "interface-output",
    .arc_index_ptr = &ip6_main.lookup_main.output_feature_arc_index,
  };
  
  VNET_FEATURE_INIT (ip6_outacl, static) = {
    .arc_name = "ip6-output",
    .node_name = "ip6-outacl",
    .runs_before = VNET_FEATURES ("ipsec6-output-feature"),
  };
  
  VNET_FEATURE_INIT (ip6_ipsec_output, static) = {
    .arc_name = "ip6-output",
    .node_name = "ipsec6-output-feature",
    .runs_before = VNET_FEATURES ("interface-output"),
  };
  
  VNET_FEATURE_INIT (ip6_interface_output, static) = {
    .arc_name = "ip6-output",
    .node_name = "interface-output",
    .runs_before = 0, /* not before any other features */
  };
  /* *INDENT-ON* */
  
  static clib_error_t *
  ip6_sw_interface_add_del (vnet_main_t * vnm, u32 sw_if_index, u32 is_add)
  {
    ip6_main_t *im = &ip6_main;
  
    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)
      {
        /* Ensure that IPv6 is disabled */
        ip6_main_t *im6 = &ip6_main;
        ip_lookup_main_t *lm6 = &im6->lookup_main;
        ip_interface_address_t *ia = 0;
        ip6_address_t *address;
        vlib_main_t *vm = vlib_get_main ();
  
        vnet_sw_interface_update_unnumbered (sw_if_index, ~0, 0);
        /* *INDENT-OFF* */
        foreach_ip_interface_address (lm6, ia, sw_if_index, 0,
        ({
          address = ip_interface_address_get_address (lm6, ia);
          ip6_add_del_interface_address(vm, sw_if_index, address, ia->address_length, 1);
        }));
        /* *INDENT-ON* */
        ip6_mfib_interface_enable_disable (sw_if_index, 0);
      }
  
    vnet_feature_enable_disable ("ip6-unicast", "ip6-not-enabled", sw_if_index,
  			       is_add, 0, 0);
  
    vnet_feature_enable_disable ("ip6-multicast", "ip6-not-enabled",
  			       sw_if_index, is_add, 0, 0);
  
    return /* no error */ 0;
  }
  
  VNET_SW_INTERFACE_ADD_DEL_FUNCTION (ip6_sw_interface_add_del);
  
  VLIB_NODE_FN (ip6_lookup_node) (vlib_main_t * vm,
  				vlib_node_runtime_t * node,
  				vlib_frame_t * frame)
  {
    return ip6_lookup_inline (vm, node, frame);
  }
  
  static u8 *format_ip6_lookup_trace (u8 * s, va_list * args);
  
  /* *INDENT-OFF* */
  VLIB_REGISTER_NODE (ip6_lookup_node) =
  {
    .name = "ip6-lookup",
    .vector_size = sizeof (u32),
    .format_trace = format_ip6_lookup_trace,
    .n_next_nodes = IP6_LOOKUP_N_NEXT,
    .next_nodes = IP6_LOOKUP_NEXT_NODES,
  };
  /* *INDENT-ON* */
  
  VLIB_NODE_FN (ip6_load_balance_node) (vlib_main_t * vm,
  				      vlib_node_runtime_t * node,
  				      vlib_frame_t * frame)
  {
    vlib_combined_counter_main_t *cm = &load_balance_main.lbm_via_counters;
    u32 n_left, *from;
    u32 thread_index = vm->thread_index;
    ip6_main_t *im = &ip6_main;
    vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs;
    u16 nexts[VLIB_FRAME_SIZE], *next;
  
    from = vlib_frame_vector_args (frame);
    n_left = frame->n_vectors;
    next = nexts;
  
    vlib_get_buffers (vm, from, bufs, n_left);
  
    while (n_left >= 4)
      {
        const load_balance_t *lb0, *lb1;
        const ip6_header_t *ip0, *ip1;
        u32 lbi0, hc0, lbi1, hc1;
        const dpo_id_t *dpo0, *dpo1;
  
        /* Prefetch next iteration. */
        {
  	vlib_prefetch_buffer_header (b[2], STORE);
  	vlib_prefetch_buffer_header (b[3], STORE);
  
  	CLIB_PREFETCH (b[2]->data, sizeof (ip0[0]), STORE);
  	CLIB_PREFETCH (b[3]->data, sizeof (ip0[0]), STORE);
        }
  
        ip0 = vlib_buffer_get_current (b[0]);
        ip1 = vlib_buffer_get_current (b[1]);
        lbi0 = vnet_buffer (b[0])->ip.adj_index[VLIB_TX];
        lbi1 = vnet_buffer (b[1])->ip.adj_index[VLIB_TX];
  
        lb0 = load_balance_get (lbi0);
        lb1 = load_balance_get (lbi1);
  
        /*
         * this node is for via FIBs we can re-use the hash value from the
         * to node if present.
         * We don't want to use the same hash value at each level in the recursion
         * graph as that would lead to polarisation
         */
        hc0 = hc1 = 0;
  
        if (PREDICT_FALSE (lb0->lb_n_buckets > 1))
  	{
  	  if (PREDICT_TRUE (vnet_buffer (b[0])->ip.flow_hash))
  	    {
  	      hc0 = vnet_buffer (b[0])->ip.flow_hash =
  		vnet_buffer (b[0])->ip.flow_hash >> 1;
  	    }
  	  else
  	    {
  	      hc0 = vnet_buffer (b[0])->ip.flow_hash =
  		ip6_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))
  	{
  	  if (PREDICT_TRUE (vnet_buffer (b[1])->ip.flow_hash))
  	    {
  	      hc1 = vnet_buffer (b[1])->ip.flow_hash =
  		vnet_buffer (b[1])->ip.flow_hash >> 1;
  	    }
  	  else
  	    {
  	      hc1 = vnet_buffer (b[1])->ip.flow_hash =
  		ip6_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);
  	}
  
        next[0] = dpo0->dpoi_next_node;
        next[1] = dpo1->dpoi_next_node;
  
        /* Only process the HBH Option Header if explicitly configured to do so */
        if (PREDICT_FALSE (ip0->protocol == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS))
  	{
  	  next[0] = (dpo_is_adj (dpo0) && im->hbh_enabled) ?
  	    (ip_lookup_next_t) IP6_LOOKUP_NEXT_HOP_BY_HOP : next[0];
  	}
        /* Only process the HBH Option Header if explicitly configured to do so */
        if (PREDICT_FALSE (ip1->protocol == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS))
  	{
  	  next[1] = (dpo_is_adj (dpo1) && im->hbh_enabled) ?
  	    (ip_lookup_next_t) IP6_LOOKUP_NEXT_HOP_BY_HOP : next[1];
  	}
  
        vnet_buffer (b[0])->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
        vnet_buffer (b[1])->ip.adj_index[VLIB_TX] = dpo1->dpoi_index;
  
        vlib_increment_combined_counter
  	(cm, thread_index, lbi0, 1, vlib_buffer_length_in_chain (vm, b[0]));
        vlib_increment_combined_counter
  	(cm, thread_index, lbi1, 1, vlib_buffer_length_in_chain (vm, b[1]));
  
        b += 2;
        next += 2;
        n_left -= 2;
      }
  
    while (n_left > 0)
      {
        const load_balance_t *lb0;
        const ip6_header_t *ip0;
        const dpo_id_t *dpo0;
        u32 lbi0, hc0;
  
        ip0 = vlib_buffer_get_current (b[0]);
        lbi0 = vnet_buffer (b[0])->ip.adj_index[VLIB_TX];
  
        lb0 = load_balance_get (lbi0);
  
        hc0 = 0;
        if (PREDICT_FALSE (lb0->lb_n_buckets > 1))
  	{
  	  if (PREDICT_TRUE (vnet_buffer (b[0])->ip.flow_hash))
  	    {
  	      hc0 = vnet_buffer (b[0])->ip.flow_hash =
  		vnet_buffer (b[0])->ip.flow_hash >> 1;
  	    }
  	  else
  	    {
  	      hc0 = vnet_buffer (b[0])->ip.flow_hash =
  		ip6_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);
  	}
  
        next[0] = dpo0->dpoi_next_node;
        vnet_buffer (b[0])->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
  
        /* Only process the HBH Option Header if explicitly configured to do so */
        if (PREDICT_FALSE (ip0->protocol == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS))
  	{
  	  next[0] = (dpo_is_adj (dpo0) && im->hbh_enabled) ?
  	    (ip_lookup_next_t) IP6_LOOKUP_NEXT_HOP_BY_HOP : next[0];
  	}
  
        vlib_increment_combined_counter
  	(cm, thread_index, lbi0, 1, vlib_buffer_length_in_chain (vm, b[0]));
  
        b += 1;
        next += 1;
        n_left -= 1;
      }
  
    vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
  
    if (node->flags & VLIB_NODE_FLAG_TRACE)
      ip6_forward_next_trace (vm, node, frame, VLIB_TX);
  
    return frame->n_vectors;
  }
  
  /* *INDENT-OFF* */
  VLIB_REGISTER_NODE (ip6_load_balance_node) =
  {
    .name = "ip6-load-balance",
    .vector_size = sizeof (u32),
    .sibling_of = "ip6-lookup",
    .format_trace = format_ip6_lookup_trace,
  };
  /* *INDENT-ON* */
  
  typedef struct
  {
    /* Adjacency taken. */
    u32 adj_index;
    u32 flow_hash;
    u32 fib_index;
  
    /* Packet data, possibly *after* rewrite. */
    u8 packet_data[128 - 1 * sizeof (u32)];
  }
  ip6_forward_next_trace_t;
  
  #ifndef CLIB_MARCH_VARIANT
  u8 *
  format_ip6_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 *);
    ip6_forward_next_trace_t *t = va_arg (*args, ip6_forward_next_trace_t *);
    u32 indent = format_get_indent (s);
  
    s = format (s, "%Ufib:%d adj:%d flow:%d",
  	      format_white_space, indent,
  	      t->fib_index, t->adj_index, t->flow_hash);
    s = format (s, "\n%U%U",
  	      format_white_space, indent,
  	      format_ip6_header, t->packet_data, sizeof (t->packet_data));
    return s;
  }
  #endif
  
  static u8 *
  format_ip6_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 *);
    ip6_forward_next_trace_t *t = va_arg (*args, ip6_forward_next_trace_t *);
    u32 indent = format_get_indent (s);
  
    s = format (s, "fib %d dpo-idx %d flow hash: 0x%08x",
  	      t->fib_index, t->adj_index, t->flow_hash);
    s = format (s, "\n%U%U",
  	      format_white_space, indent,
  	      format_ip6_header, t->packet_data, sizeof (t->packet_data));
    return s;
  }
  
  
  static u8 *
  format_ip6_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 *);
    ip6_forward_next_trace_t *t = va_arg (*args, ip6_forward_next_trace_t *);
    u32 indent = format_get_indent (s);
  
    s = format (s, "tx_sw_if_index %d adj-idx %d : %U flow hash: 0x%08x",
  	      t->fib_index, t->adj_index, format_ip_adjacency,
  	      t->adj_index, FORMAT_IP_ADJACENCY_NONE, t->flow_hash);
    s = format (s, "\n%U%U",
  	      format_white_space, indent,
  	      format_ip_adjacency_packet_data,
  	      t->packet_data, sizeof (t->packet_data));
    return s;
  }
  
  /* Common trace function for all ip6-forward next nodes. */
  #ifndef CLIB_MARCH_VARIANT
  void
  ip6_forward_next_trace (vlib_main_t * vm,
  			vlib_node_runtime_t * node,
  			vlib_frame_t * frame, vlib_rx_or_tx_t which_adj_index)
  {
    u32 *from, n_left;
    ip6_main_t *im = &ip6_main;
  
    n_left = frame->n_vectors;
    from = vlib_frame_vector_args (frame);
  
    while (n_left >= 4)
      {
        u32 bi0, bi1;
        vlib_buffer_t *b0, *b1;
        ip6_forward_next_trace_t *t0, *t1;
  
        /* Prefetch next iteration. */
        vlib_prefetch_buffer_with_index (vm, from[2], LOAD);
        vlib_prefetch_buffer_with_index (vm, from[3], LOAD);
  
        bi0 = from[0];
        bi1 = from[1];
  
        b0 = vlib_get_buffer (vm, bi0);
        b1 = vlib_get_buffer (vm, bi1);
  
        if (b0->flags & VLIB_BUFFER_IS_TRACED)
  	{
  	  t0 = vlib_add_trace (vm, node, b0, sizeof (t0[0]));
  	  t0->adj_index = vnet_buffer (b0)->ip.adj_index[which_adj_index];
  	  t0->flow_hash = vnet_buffer (b0)->ip.flow_hash;
  	  t0->fib_index =
  	    (vnet_buffer (b0)->sw_if_index[VLIB_TX] !=
  	     (u32) ~ 0) ? vnet_buffer (b0)->sw_if_index[VLIB_TX] :
  	    vec_elt (im->fib_index_by_sw_if_index,
  		     vnet_buffer (b0)->sw_if_index[VLIB_RX]);
  
  	  clib_memcpy_fast (t0->packet_data,
  			    vlib_buffer_get_current (b0),
  			    sizeof (t0->packet_data));
  	}
        if (b1->flags & VLIB_BUFFER_IS_TRACED)
  	{
  	  t1 = vlib_add_trace (vm, node, b1, sizeof (t1[0]));
  	  t1->adj_index = vnet_buffer (b1)->ip.adj_index[which_adj_index];
  	  t1->flow_hash = vnet_buffer (b1)->ip.flow_hash;
  	  t1->fib_index =
  	    (vnet_buffer (b1)->sw_if_index[VLIB_TX] !=
  	     (u32) ~ 0) ? vnet_buffer (b1)->sw_if_index[VLIB_TX] :
  	    vec_elt (im->fib_index_by_sw_if_index,
  		     vnet_buffer (b1)->sw_if_index[VLIB_RX]);
  
  	  clib_memcpy_fast (t1->packet_data,
  			    vlib_buffer_get_current (b1),
  			    sizeof (t1->packet_data));
  	}
        from += 2;
        n_left -= 2;
      }
  
    while (n_left >= 1)
      {
        u32 bi0;
        vlib_buffer_t *b0;
        ip6_forward_next_trace_t *t0;
  
        bi0 = from[0];
  
        b0 = vlib_get_buffer (vm, bi0);
  
        if (b0->flags & VLIB_BUFFER_IS_TRACED)
  	{
  	  t0 = vlib_add_trace (vm, node, b0, sizeof (t0[0]));
  	  t0->adj_index = vnet_buffer (b0)->ip.adj_index[which_adj_index];
  	  t0->flow_hash = vnet_buffer (b0)->ip.flow_hash;
  	  t0->fib_index =
  	    (vnet_buffer (b0)->sw_if_index[VLIB_TX] !=
  	     (u32) ~ 0) ? vnet_buffer (b0)->sw_if_index[VLIB_TX] :
  	    vec_elt (im->fib_index_by_sw_if_index,
  		     vnet_buffer (b0)->sw_if_index[VLIB_RX]);
  
  	  clib_memcpy_fast (t0->packet_data,
  			    vlib_buffer_get_current (b0),
  			    sizeof (t0->packet_data));
  	}
        from += 1;
        n_left -= 1;
      }
  }
  
  /* Compute TCP/UDP/ICMP6 checksum in software. */
  u16
  ip6_tcp_udp_icmp_compute_checksum (vlib_main_t * vm, vlib_buffer_t * p0,
  				   ip6_header_t * ip0, int *bogus_lengthp)
  {
    ip_csum_t sum0 = 0;
    u16 payload_length, payload_length_host_byte_order;
    u32 i;
    u32 headers_size = sizeof (ip0[0]);
    u8 *data_this_buffer;
    u8 next_hdr = ip0->protocol;
  
    ASSERT (bogus_lengthp);
    *bogus_lengthp = 0;
  
    payload_length_host_byte_order = clib_net_to_host_u16 (ip0->payload_length);
    data_this_buffer = (u8 *) (ip0 + 1);
    payload_length = ip0->payload_length;
  
    /* some icmp packets may come with a "router alert" hop-by-hop extension header (e.g., mldv2 packets)
     * or UDP-Ping packets */
    if (PREDICT_FALSE (next_hdr == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS))
      {
        u32 skip_bytes;
        ip6_hop_by_hop_ext_t *ext_hdr =
  	(ip6_hop_by_hop_ext_t *) data_this_buffer;
  
        /* validate really icmp6 next */
        ASSERT ((ext_hdr->next_hdr == IP_PROTOCOL_ICMP6)
  	      || (ext_hdr->next_hdr == IP_PROTOCOL_UDP));
  
        skip_bytes = 8 * (1 + ext_hdr->n_data_u64s);
        data_this_buffer = (void *) ((u8 *) data_this_buffer + skip_bytes);
  
        payload_length_host_byte_order -= skip_bytes;
        headers_size += skip_bytes;
  
        /* pseudo-header adjustments:
         *   exclude ext header bytes from payload length
         *   use payload IP proto rather than ext header IP proto
         */
        payload_length = clib_host_to_net_u16 (payload_length_host_byte_order);
        next_hdr = ext_hdr->next_hdr;
      }
  
    /* Initialize checksum with ip pseudo-header. */
    sum0 = payload_length + clib_host_to_net_u16 (next_hdr);
  
    for (i = 0; i < ARRAY_LEN (ip0->src_address.as_uword); i++)
      {
        sum0 = ip_csum_with_carry
  	(sum0, clib_mem_unaligned (&ip0->src_address.as_uword[i], uword));
        sum0 = ip_csum_with_carry
  	(sum0, clib_mem_unaligned (&ip0->dst_address.as_uword[i], uword));
      }
  
    if (p0)
      return ip_calculate_l4_checksum (vm, p0, sum0,
  				     payload_length_host_byte_order,
  				     (u8 *) ip0, headers_size, NULL);
    else
      return ip_calculate_l4_checksum (vm, 0, sum0,
  				     payload_length_host_byte_order, NULL, 0,
  				     data_this_buffer);
  }
  
  u32
  ip6_tcp_udp_icmp_validate_checksum (vlib_main_t * vm, vlib_buffer_t * p0)
  {
    ip6_header_t *ip0 = vlib_buffer_get_current (p0);
    udp_header_t *udp0;
    u16 sum16;
    int bogus_length;
  
    /* some icmp packets may come with a "router alert" hop-by-hop extension header (e.g., mldv2 packets) */
    ASSERT (ip0->protocol == IP_PROTOCOL_TCP
  	  || ip0->protocol == IP_PROTOCOL_ICMP6
  	  || ip0->protocol == IP_PROTOCOL_UDP
  	  || ip0->protocol == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS);
  
    udp0 = (void *) (ip0 + 1);
    if (ip0->protocol == IP_PROTOCOL_UDP && udp0->checksum == 0)
      {
        p0->flags |= (VNET_BUFFER_F_L4_CHECKSUM_COMPUTED
  		    | VNET_BUFFER_F_L4_CHECKSUM_CORRECT);
        return p0->flags;
      }
  
    sum16 = ip6_tcp_udp_icmp_compute_checksum (vm, p0, ip0, &bogus_length);
  
    p0->flags |= (VNET_BUFFER_F_L4_CHECKSUM_COMPUTED
  		| ((sum16 == 0) << VNET_BUFFER_F_LOG2_L4_CHECKSUM_CORRECT));
  
    return p0->flags;
  }
  #endif
  
  /**
   * @brief returns number of links on which src is reachable.
   */
  always_inline int
  ip6_urpf_loose_check (ip6_main_t * im, vlib_buffer_t * b, ip6_header_t * i)
  {
    const load_balance_t *lb0;
    index_t lbi;
    u32 fib_index;
  
    fib_index = vec_elt (im->fib_index_by_sw_if_index,
  		       vnet_buffer (b)->sw_if_index[VLIB_RX]);
    fib_index =
      (vnet_buffer (b)->sw_if_index[VLIB_TX] == (u32) ~ 0) ?
      fib_index : vnet_buffer (b)->sw_if_index[VLIB_TX];
  
    lbi = ip6_fib_table_fwding_lookup (fib_index, &i->src_address);
    lb0 = load_balance_get (lbi);
  
    return (fib_urpf_check_size (lb0->lb_urpf));
  }
  
  always_inline u8
  ip6_next_proto_is_tcp_udp (vlib_buffer_t * p0, ip6_header_t * ip0,
  			   u32 * udp_offset0)
  {
    u32 proto0;
    proto0 = ip6_locate_header (p0, ip0, IP_PROTOCOL_UDP, udp_offset0);
    if (proto0 != IP_PROTOCOL_UDP)
      {
        proto0 = ip6_locate_header (p0, ip0, IP_PROTOCOL_TCP, udp_offset0);
        proto0 = (proto0 == IP_PROTOCOL_TCP) ? proto0 : 0;
      }
    return proto0;
  }
  
  /* *INDENT-OFF* */
  VNET_FEATURE_ARC_INIT (ip6_local) =
  {
    .arc_name  = "ip6-local",
    .start_nodes = VNET_FEATURES ("ip6-local"),
  };
  /* *INDENT-ON* */
  
  static_always_inline u8
  ip6_tcp_udp_icmp_bad_length (vlib_main_t * vm, vlib_buffer_t * p0)
  {
  
    u16 payload_length_host_byte_order;
    u32 n_this_buffer, n_bytes_left;
    ip6_header_t *ip0 = vlib_buffer_get_current (p0);
    u32 headers_size = sizeof (ip0[0]);
    u8 *data_this_buffer;
  
  
    data_this_buffer = (u8 *) (ip0 + 1);
  
    ip6_hop_by_hop_ext_t *ext_hdr = (ip6_hop_by_hop_ext_t *) data_this_buffer;
  
    /* validate really icmp6 next */
  
    if (!(ext_hdr->next_hdr == IP_PROTOCOL_ICMP6)
        || (ext_hdr->next_hdr == IP_PROTOCOL_UDP))
      return 0;
  
  
    payload_length_host_byte_order = clib_net_to_host_u16 (ip0->payload_length);
    n_bytes_left = n_this_buffer = payload_length_host_byte_order;
  
  
    u32 n_ip_bytes_this_buffer =
      p0->current_length - (((u8 *) ip0 - p0->data) - p0->current_data);
    if (n_this_buffer + headers_size > n_ip_bytes_this_buffer)
      {
        n_this_buffer = p0->current_length > headers_size ?
  	n_ip_bytes_this_buffer - headers_size : 0;
      }
  
    n_bytes_left -= n_this_buffer;
    n_bytes_left -= p0->total_length_not_including_first_buffer;
  
    if (n_bytes_left == 0)
      return 0;
    else
      return 1;
  }
  
  
  always_inline uword
  ip6_local_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
  		  vlib_frame_t * frame, int head_of_feature_arc)
  {
    ip6_main_t *im = &ip6_main;
    ip_lookup_main_t *lm = &im->lookup_main;
    u32 *from, n_left_from;
    vlib_node_runtime_t *error_node =
      vlib_node_get_runtime (vm, ip6_input_node.index);
    u8 arc_index = vnet_feat_arc_ip6_local.feature_arc_index;
    vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
    u16 nexts[VLIB_FRAME_SIZE], *next;
  
    from = vlib_frame_vector_args (frame);
    n_left_from = frame->n_vectors;
  
    if (node->flags & VLIB_NODE_FLAG_TRACE)
      ip6_forward_next_trace (vm, node, frame, VLIB_TX);
  
    vlib_get_buffers (vm, from, bufs, n_left_from);
    b = bufs;
    next = nexts;
  
    while (n_left_from > 2)
      {
        /* Prefetch next iteration. */
        if (n_left_from >= 6)
  	{
  	  vlib_prefetch_buffer_header (b[4], STORE);
  	  vlib_prefetch_buffer_header (b[5], STORE);
  	  vlib_prefetch_buffer_data (b[2], LOAD);
  	  vlib_prefetch_buffer_data (b[3], LOAD);
  	}
  
        u8 error[2];
        error[0] = IP6_ERROR_UNKNOWN_PROTOCOL;
        error[1] = IP6_ERROR_UNKNOWN_PROTOCOL;
  
        ip6_header_t *ip[2];
        ip[0] = vlib_buffer_get_current (b[0]);
        ip[1] = vlib_buffer_get_current (b[1]);
  
        if (head_of_feature_arc)
  	{
  	  vnet_buffer (b[0])->l3_hdr_offset = b[0]->current_data;
  	  vnet_buffer (b[1])->l3_hdr_offset = b[1]->current_data;
  
  	  u8 type[2];
  	  type[0] = lm->builtin_protocol_by_ip_protocol[ip[0]->protocol];
  	  type[1] = lm->builtin_protocol_by_ip_protocol[ip[1]->protocol];
  
  	  u32 flags[2];
  	  flags[0] = b[0]->flags;
  	  flags[1] = b[1]->flags;
  
  	  u32 good_l4_csum[2];
  	  good_l4_csum[0] =
  	    flags[0] & (VNET_BUFFER_F_L4_CHECKSUM_CORRECT |
  			VNET_BUFFER_F_OFFLOAD_TCP_CKSUM |
  			VNET_BUFFER_F_OFFLOAD_UDP_CKSUM);
  	  good_l4_csum[1] =
  	    flags[1] & (VNET_BUFFER_F_L4_CHECKSUM_CORRECT |
  			VNET_BUFFER_F_OFFLOAD_TCP_CKSUM |
  			VNET_BUFFER_F_OFFLOAD_UDP_CKSUM);
  
  	  u32 udp_offset[2] = { };
  	  u8 is_tcp_udp[2];
  	  is_tcp_udp[0] =
  	    ip6_next_proto_is_tcp_udp (b[0], ip[0], &udp_offset[0]);
  	  is_tcp_udp[1] =
  	    ip6_next_proto_is_tcp_udp (b[1], ip[1], &udp_offset[1]);
  	  i16 len_diff[2] = { 0 };
  	  if (PREDICT_TRUE (is_tcp_udp[0]))
  	    {
  	      udp_header_t *udp =
  		(udp_header_t *) ((u8 *) ip[0] + udp_offset[0]);
  	      good_l4_csum[0] |= type[0] == IP_BUILTIN_PROTOCOL_UDP
  		&& udp->checksum == 0;
  	      /* optimistically verify UDP length. */
  	      u16 ip_len, udp_len;
  	      ip_len = clib_net_to_host_u16 (ip[0]->payload_length);
  	      udp_len = clib_net_to_host_u16 (udp->length);
  	      len_diff[0] = ip_len - udp_len;
  	    }
  	  if (PREDICT_TRUE (is_tcp_udp[1]))
  	    {
  	      udp_header_t *udp =
  		(udp_header_t *) ((u8 *) ip[1] + udp_offset[1]);
  	      good_l4_csum[1] |= type[1] == IP_BUILTIN_PROTOCOL_UDP
  		&& udp->checksum == 0;
  	      /* optimistically verify UDP length. */
  	      u16 ip_len, udp_len;
  	      ip_len = clib_net_to_host_u16 (ip[1]->payload_length);
  	      udp_len = clib_net_to_host_u16 (udp->length);
  	      len_diff[1] = ip_len - udp_len;
  	    }
  
  	  good_l4_csum[0] |= type[0] == IP_BUILTIN_PROTOCOL_UNKNOWN;
  	  good_l4_csum[1] |= type[1] == IP_BUILTIN_PROTOCOL_UNKNOWN;
  
  	  len_diff[0] = type[0] == IP_BUILTIN_PROTOCOL_UDP ? len_diff[0] : 0;
  	  len_diff[1] = type[1] == IP_BUILTIN_PROTOCOL_UDP ? len_diff[1] : 0;
  
  	  u8 need_csum[2];
  	  need_csum[0] = type[0] != IP_BUILTIN_PROTOCOL_UNKNOWN
  	    && !good_l4_csum[0]
  	    && !(flags[0] & VNET_BUFFER_F_L4_CHECKSUM_COMPUTED);
  	  need_csum[1] = type[1] != IP_BUILTIN_PROTOCOL_UNKNOWN
  	    && !good_l4_csum[1]
  	    && !(flags[1] & VNET_BUFFER_F_L4_CHECKSUM_COMPUTED);
  	  if (PREDICT_FALSE (need_csum[0]))
  	    {
  	      flags[0] = ip6_tcp_udp_icmp_validate_checksum (vm, b[0]);
  	      good_l4_csum[0] = flags[0] & VNET_BUFFER_F_L4_CHECKSUM_CORRECT;
  	      error[0] = IP6_ERROR_UNKNOWN_PROTOCOL;
  	    }
  	  else
  	    {
  	      if (ip6_tcp_udp_icmp_bad_length (vm, b[0]))
  		error[0] = IP6_ERROR_BAD_LENGTH;
  	    }
  	  if (PREDICT_FALSE (need_csum[1]))
  	    {
  	      flags[1] = ip6_tcp_udp_icmp_validate_checksum (vm, b[1]);
  	      good_l4_csum[1] = flags[1] & VNET_BUFFER_F_L4_CHECKSUM_CORRECT;
  	      error[1] = IP6_ERROR_UNKNOWN_PROTOCOL;
  	    }
  	  else
  	    {
  	      if (ip6_tcp_udp_icmp_bad_length (vm, b[1]))
  		error[1] = IP6_ERROR_BAD_LENGTH;
  	    }
  
  
  	  error[0] = len_diff[0] < 0 ? IP6_ERROR_UDP_LENGTH : error[0];
  
  	  error[1] = len_diff[1] < 0 ? IP6_ERROR_UDP_LENGTH : error[1];
  
  	  STATIC_ASSERT (IP6_ERROR_UDP_CHECKSUM + IP_BUILTIN_PROTOCOL_UDP ==
  			 IP6_ERROR_UDP_CHECKSUM,
  			 "Wrong IP6 errors constants");
  	  STATIC_ASSERT (IP6_ERROR_UDP_CHECKSUM + IP_BUILTIN_PROTOCOL_ICMP ==
  			 IP6_ERROR_ICMP_CHECKSUM,
  			 "Wrong IP6 errors constants");
  
  	  error[0] =
  	    !good_l4_csum[0] ? IP6_ERROR_UDP_CHECKSUM + type[0] : error[0];
  	  error[1] =
  	    !good_l4_csum[1] ? IP6_ERROR_UDP_CHECKSUM + type[1] : error[1];
  
  	  /* Drop packets from unroutable hosts. */
  	  /* If this is a neighbor solicitation (ICMP), skip source RPF check */
  	  u8 unroutable[2];
  	  unroutable[0] = error[0] == IP6_ERROR_UNKNOWN_PROTOCOL
  	    && type[0] != IP_BUILTIN_PROTOCOL_ICMP
  	    && !ip6_address_is_link_local_unicast (&ip[0]->src_address);
  	  unroutable[1] = error[1] == IP6_ERROR_UNKNOWN_PROTOCOL
  	    && type[1] != IP_BUILTIN_PROTOCOL_ICMP
  	    && !ip6_address_is_link_local_unicast (&ip[1]->src_address);
  	  if (PREDICT_FALSE (unroutable[0]))
  	    {
  	      error[0] =
  		!ip6_urpf_loose_check (im, b[0],
  				       ip[0]) ? IP6_ERROR_SRC_LOOKUP_MISS
  		: error[0];
  	    }
  	  if (PREDICT_FALSE (unroutable[1]))
  	    {
  	      error[1] =
  		!ip6_urpf_loose_check (im, b[1],
  				       ip[1]) ? IP6_ERROR_SRC_LOOKUP_MISS
  		: error[1];
  	    }
  
  	  vnet_buffer (b[0])->ip.fib_index =
  	    vnet_buffer (b[0])->sw_if_index[VLIB_TX] != ~0 ?
  	    vnet_buffer (b[0])->sw_if_index[VLIB_TX] :
  	    vnet_buffer (b[0])->ip.fib_index;
  	  vnet_buffer (b[1])->ip.fib_index =
  	    vnet_buffer (b[1])->sw_if_index[VLIB_TX] != ~0 ?
  	    vnet_buffer (b[1])->sw_if_index[VLIB_TX] :
  	    vnet_buffer (b[1])->ip.fib_index;
  	}			/* head_of_feature_arc */
  
        next[0] = lm->local_next_by_ip_protocol[ip[0]->protocol];
        next[0] =
  	error[0] != IP6_ERROR_UNKNOWN_PROTOCOL ? IP_LOCAL_NEXT_DROP : next[0];
        next[1] = lm->local_next_by_ip_protocol[ip[1]->protocol];
        next[1] =
  	error[1] != IP6_ERROR_UNKNOWN_PROTOCOL ? IP_LOCAL_NEXT_DROP : next[1];
  
        b[0]->error = error_node->errors[0];
        b[1]->error = error_node->errors[1];
  
        if (head_of_feature_arc)
  	{
  	  u8 ip6_unknown[2];
  	  ip6_unknown[0] = error[0] == (u8) IP6_ERROR_UNKNOWN_PROTOCOL;
  	  ip6_unknown[1] = error[1] == (u8) IP6_ERROR_UNKNOWN_PROTOCOL;
  	  if (PREDICT_TRUE (ip6_unknown[0]))
  	    {
  	      u32 next32 = next[0];
  	      vnet_feature_arc_start (arc_index,
  				      vnet_buffer (b[0])->sw_if_index
  				      [VLIB_RX], &next32, b[0]);
  	      next[0] = next32;
  	    }
  	  if (PREDICT_TRUE (ip6_unknown[1]))
  	    {
  	      u32 next32 = next[1];
  	      vnet_feature_arc_start (arc_index,
  				      vnet_buffer (b[1])->sw_if_index
  				      [VLIB_RX], &next32, b[1]);
  	      next[1] = next32;
  	    }
  	}
  
        /* next */
        b += 2;
        next += 2;
        n_left_from -= 2;
      }
  
    while (n_left_from)
      {
        u8 error;
        error = IP6_ERROR_UNKNOWN_PROTOCOL;
  
        ip6_header_t *ip;
        ip = vlib_buffer_get_current (b[0]);
  
        if (head_of_feature_arc)
  	{
  	  vnet_buffer (b[0])->l3_hdr_offset = b[0]->current_data;
  	  u8 type = lm->builtin_protocol_by_ip_protocol[ip->protocol];
  
  	  u32 flags = b[0]->flags;
  	  u32 good_l4_csum =
  	    flags & (VNET_BUFFER_F_L4_CHECKSUM_CORRECT |
  		     VNET_BUFFER_F_OFFLOAD_TCP_CKSUM |
  		     VNET_BUFFER_F_OFFLOAD_UDP_CKSUM);
  
  	  u32 udp_offset;
  	  i16 len_diff = 0;
  	  u8 is_tcp_udp = ip6_next_proto_is_tcp_udp (b[0], ip, &udp_offset);
  	  if (PREDICT_TRUE (is_tcp_udp))
  	    {
  	      udp_header_t *udp = (udp_header_t *) ((u8 *) ip + udp_offset);
  	      /* Don't verify UDP checksum for packets with explicit zero checksum. */
  	      good_l4_csum |= type == IP_BUILTIN_PROTOCOL_UDP
  		&& udp->checksum == 0;
  	      /* optimistically verify UDP length. */
  	      u16 ip_len, udp_len;
  	      ip_len = clib_net_to_host_u16 (ip->payload_length);
  	      udp_len = clib_net_to_host_u16 (udp->length);
  	      len_diff = ip_len - udp_len;
  	    }
  
  	  good_l4_csum |= type == IP_BUILTIN_PROTOCOL_UNKNOWN;
  	  len_diff = type == IP_BUILTIN_PROTOCOL_UDP ? len_diff : 0;
  
  	  u8 need_csum = type != IP_BUILTIN_PROTOCOL_UNKNOWN && !good_l4_csum
  	    && !(flags & VNET_BUFFER_F_L4_CHECKSUM_COMPUTED);
  	  if (PREDICT_FALSE (need_csum))
  	    {
  	      flags = ip6_tcp_udp_icmp_validate_checksum (vm, b[0]);
  	      good_l4_csum = flags & VNET_BUFFER_F_L4_CHECKSUM_CORRECT;
  	      error = IP6_ERROR_UNKNOWN_PROTOCOL;
  	    }
  	  else
  	    {
  	      if (ip6_tcp_udp_icmp_bad_length (vm, b[0]))
  		error = IP6_ERROR_BAD_LENGTH;
  	    }
  
  
  
  	  error = len_diff < 0 ? IP6_ERROR_UDP_LENGTH : error;
  
  	  STATIC_ASSERT (IP6_ERROR_UDP_CHECKSUM + IP_BUILTIN_PROTOCOL_UDP ==
  			 IP6_ERROR_UDP_CHECKSUM,
  			 "Wrong IP6 errors constants");
  	  STATIC_ASSERT (IP6_ERROR_UDP_CHECKSUM + IP_BUILTIN_PROTOCOL_ICMP ==
  			 IP6_ERROR_ICMP_CHECKSUM,
  			 "Wrong IP6 errors constants");
  
  	  error = !good_l4_csum ? IP6_ERROR_UDP_CHECKSUM + type : error;
  
  	  /* Drop packets from unroutable hosts. */
  	  /* If this is a neighbor solicitation (ICMP), skip source RPF check */
  	  u8 unroutable = error == IP6_ERROR_UNKNOWN_PROTOCOL
  	    && type != IP_BUILTIN_PROTOCOL_ICMP
  	    && !ip6_address_is_link_local_unicast (&ip->src_address);
  	  if (PREDICT_FALSE (unroutable))
  	    {
  	      error =
  		!ip6_urpf_loose_check (im, b[0],
  				       ip) ? IP6_ERROR_SRC_LOOKUP_MISS :
  		error;
  	    }
  
  	  vnet_buffer (b[0])->ip.fib_index =
  	    vnet_buffer (b[0])->sw_if_index[VLIB_TX] != ~0 ?
  	    vnet_buffer (b[0])->sw_if_index[VLIB_TX] :
  	    vnet_buffer (b[0])->ip.fib_index;
  	}			/* head_of_feature_arc */
  
        next[0] = lm->local_next_by_ip_protocol[ip->protocol];
        next[0] =
  	error != IP6_ERROR_UNKNOWN_PROTOCOL ? IP_LOCAL_NEXT_DROP : next[0];
  
        b[0]->error = error_node->errors[0];
  
        if (head_of_feature_arc)
  	{
  	  if (PREDICT_TRUE (error == (u8) IP6_ERROR_UNKNOWN_PROTOCOL))
  	    {
  	      u32 next32 = next[0];
  	      vnet_feature_arc_start (arc_index,
  				      vnet_buffer (b[0])->sw_if_index
  				      [VLIB_RX], &next32, b[0]);
  	      next[0] = next32;
  	    }
  	}
  
        /* next */
        b += 1;
        next += 1;
        n_left_from -= 1;
      }
  
    vlib_buffer_enqueue_to_next (vm, node, from, nexts, frame->n_vectors);
    return frame->n_vectors;
  }
  
  VLIB_NODE_FN (ip6_local_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
  			       vlib_frame_t * frame)
  {
    return ip6_local_inline (vm, node, frame, 1 /* head of feature arc */ );
  }
  
  /* *INDENT-OFF* */
  VLIB_REGISTER_NODE (ip6_local_node) =
  {
    .name = "ip6-local",
    .vector_size = sizeof (u32),
    .format_trace = format_ip6_forward_next_trace,
    .n_next_nodes = IP_LOCAL_N_NEXT,
    .next_nodes =
    {
      [IP_LOCAL_NEXT_DROP] = "ip6-drop",
      [IP_LOCAL_NEXT_PUNT] = "ip6-punt",
      [IP_LOCAL_NEXT_UDP_LOOKUP] = "ip6-udp-lookup",
      [IP_LOCAL_NEXT_ICMP] = "ip6-icmp-input",
      [IP_LOCAL_NEXT_REASSEMBLY] = "ip6-full-reassembly",
    },
  };
  /* *INDENT-ON* */
  
  VLIB_NODE_FN (ip6_local_end_of_arc_node) (vlib_main_t * vm,
  					  vlib_node_runtime_t * node,
  					  vlib_frame_t * frame)
  {
    return ip6_local_inline (vm, node, frame, 0 /* head of feature arc */ );
  }
  
  /* *INDENT-OFF* */
  VLIB_REGISTER_NODE (ip6_local_end_of_arc_node) = {
    .name = "ip6-local-end-of-arc",
    .vector_size = sizeof (u32),
  
    .format_trace = format_ip6_forward_next_trace,
    .sibling_of = "ip6-local",
  };
  
  VNET_FEATURE_INIT (ip6_local_end_of_arc, static) = {
    .arc_name = "ip6-local",
    .node_name = "ip6-local-end-of-arc",
    .runs_before = 0, /* not before any other features */
  };
  /* *INDENT-ON* */
  
  #ifdef CLIB_MARCH_VARIANT
  extern vlib_node_registration_t ip6_local_node;
  #else
  void
  ip6_register_protocol (u32 protocol, u32 node_index)
  {
    vlib_main_t *vm = vlib_get_main ();
    ip6_main_t *im = &ip6_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] =
      vlib_node_add_next (vm, ip6_local_node.index, node_index);
  }
  
  void
  ip6_unregister_protocol (u32 protocol)
  {
    ip6_main_t *im = &ip6_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
  
  typedef enum
  {
    IP6_REWRITE_NEXT_DROP,
    IP6_REWRITE_NEXT_ICMP_ERROR,
    IP6_REWRITE_NEXT_FRAGMENT,
    IP6_REWRITE_N_NEXT		/* Last */
  } ip6_rewrite_next_t;
  
  /**
   * This bits of an IPv6 address to mask to construct a multicast
   * MAC address
   */
  #define IP6_MCAST_ADDR_MASK 0xffffffff
  
  always_inline void
  ip6_mtu_check (vlib_buffer_t * b, u16 packet_bytes,
  	       u16 adj_packet_bytes, bool is_locally_generated,
  	       u32 * next, u8 is_midchain, u32 * error)
  {
    if (adj_packet_bytes >= 1280 && packet_bytes > adj_packet_bytes)
      {
        if (is_locally_generated)
  	{
  	  /* IP fragmentation */
  	  ip_frag_set_vnet_buffer (b, adj_packet_bytes,
  				   (is_midchain ?
  				    IP_FRAG_NEXT_IP_REWRITE_MIDCHAIN :
  				    IP_FRAG_NEXT_IP_REWRITE), 0);
  	  *next = IP6_REWRITE_NEXT_FRAGMENT;
  	  *error = IP6_ERROR_MTU_EXCEEDED;
  	}
        else
  	{
  	  *error = IP6_ERROR_MTU_EXCEEDED;
  	  icmp6_error_set_vnet_buffer (b, ICMP6_packet_too_big, 0,
  				       adj_packet_bytes);
  	  *next = IP6_REWRITE_NEXT_ICMP_ERROR;
  	}
      }
  }
  
  always_inline uword
  ip6_rewrite_inline_with_gso (vlib_main_t * vm,
  			     vlib_node_runtime_t * node,
  			     vlib_frame_t * frame,
  			     int do_counters, int is_midchain, int is_mcast)
  {
    ip_lookup_main_t *lm = &ip6_main.lookup_main;
    u32 *from = vlib_frame_vector_args (frame);
    u32 n_left_from, n_left_to_next, *to_next, next_index;
    vlib_node_runtime_t *error_node =
      vlib_node_get_runtime (vm, ip6_input_node.index);
  
    n_left_from = frame->n_vectors;
    next_index = node->cached_next_index;
    u32 thread_index = vm->thread_index;
  
    while (n_left_from > 0)
      {
        vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  
        while (n_left_from >= 4 && n_left_to_next >= 2)
  	{
  	  const ip_adjacency_t *adj0, *adj1;
  	  vlib_buffer_t *p0, *p1;
  	  ip6_header_t *ip0, *ip1;
  	  u32 pi0, rw_len0, next0, error0, adj_index0;
  	  u32 pi1, rw_len1, next1, error1, adj_index1;
  	  u32 tx_sw_if_index0, tx_sw_if_index1;
  	  bool is_locally_originated0, is_locally_originated1;
  
  	  /* Prefetch next iteration. */
  	  {
  	    vlib_buffer_t *p2, *p3;
  
  	    p2 = vlib_get_buffer (vm, from[2]);
  	    p3 = vlib_get_buffer (vm, from[3]);
  
  	    vlib_prefetch_buffer_header (p2, LOAD);
  	    vlib_prefetch_buffer_header (p3, LOAD);
  
  	    CLIB_PREFETCH (p2->pre_data, 32, STORE);
  	    CLIB_PREFETCH (p3->pre_data, 32, STORE);
  
  	    CLIB_PREFETCH (p2->data, sizeof (ip0[0]), STORE);
  	    CLIB_PREFETCH (p3->data, sizeof (ip0[0]), STORE);
  	  }
  
  	  pi0 = to_next[0] = from[0];
  	  pi1 = to_next[1] = from[1];
  
  	  from += 2;
  	  n_left_from -= 2;
  	  to_next += 2;
  	  n_left_to_next -= 2;
  
  	  p0 = vlib_get_buffer (vm, pi0);
  	  p1 = vlib_get_buffer (vm, pi1);
  
  	  adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
  	  adj_index1 = vnet_buffer (p1)->ip.adj_index[VLIB_TX];
  
  	  ip0 = vlib_buffer_get_current (p0);
  	  ip1 = vlib_buffer_get_current (p1);
  
  	  error0 = error1 = IP6_ERROR_NONE;
  	  next0 = next1 = IP6_REWRITE_NEXT_DROP;
  
  	  is_locally_originated0 =
  	    p0->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED;
  	  if (PREDICT_TRUE (!is_locally_originated0))
  	    {
  	      i32 hop_limit0 = ip0->hop_limit;
  
  	      /* Input node should have reject packets with hop limit 0. */
  	      ASSERT (ip0->hop_limit > 0);
  
  	      hop_limit0 -= 1;
  
  	      ip0->hop_limit = hop_limit0;
  
  	      /*
  	       * If the hop count drops below 1 when forwarding, generate
  	       * an ICMP response.
  	       */
  	      if (PREDICT_FALSE (hop_limit0 <= 0))
  		{
  		  error0 = IP6_ERROR_TIME_EXPIRED;
  		  next0 = IP6_REWRITE_NEXT_ICMP_ERROR;
  		  vnet_buffer (p0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
  		  icmp6_error_set_vnet_buffer (p0, ICMP6_time_exceeded,
  					       ICMP6_time_exceeded_ttl_exceeded_in_transit,
  					       0);
  		}
  	    }
  
  	  is_locally_originated1 =
  	    p1->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED;
  	  if (PREDICT_TRUE (!is_locally_originated1))
  	    {
  	      i32 hop_limit1 = ip1->hop_limit;
  
  	      /* Input node should have reject packets with hop limit 0. */
  	      ASSERT (ip1->hop_limit > 0);
  
  	      hop_limit1 -= 1;
  
  	      ip1->hop_limit = hop_limit1;
  
  	      /*
  	       * If the hop count drops below 1 when forwarding, generate
  	       * an ICMP response.
  	       */
  	      if (PREDICT_FALSE (hop_limit1 <= 0))
  		{
  		  error1 = IP6_ERROR_TIME_EXPIRED;
  		  next1 = IP6_REWRITE_NEXT_ICMP_ERROR;
  		  vnet_buffer (p1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
  		  icmp6_error_set_vnet_buffer (p1, ICMP6_time_exceeded,
  					       ICMP6_time_exceeded_ttl_exceeded_in_transit,
  					       0);
  		}
  	    }
  
  	  adj0 = adj_get (adj_index0);
  	  adj1 = adj_get (adj_index1);
  
  	  rw_len0 = adj0[0].rewrite_header.data_bytes;
  	  rw_len1 = adj1[0].rewrite_header.data_bytes;
  	  vnet_buffer (p0)->ip.save_rewrite_length = rw_len0;
  	  vnet_buffer (p1)->ip.save_rewrite_length = rw_len1;
  
  	  if (do_counters)
  	    {
  	      vlib_increment_combined_counter
  		(&adjacency_counters,
  		 thread_index, adj_index0, 1,
  		 vlib_buffer_length_in_chain (vm, p0) + rw_len0);
  	      vlib_increment_combined_counter
  		(&adjacency_counters,
  		 thread_index, adj_index1, 1,
  		 vlib_buffer_length_in_chain (vm, p1) + rw_len1);
  	    }
  
  	  /* Check MTU of outgoing interface. */
  	  u16 ip0_len =
  	    clib_net_to_host_u16 (ip0->payload_length) +
  	    sizeof (ip6_header_t);
  	  u16 ip1_len =
  	    clib_net_to_host_u16 (ip1->payload_length) +
  	    sizeof (ip6_header_t);
  	  if (p0->flags & VNET_BUFFER_F_GSO)
  	    ip0_len = gso_mtu_sz (p0);
  	  if (p1->flags & VNET_BUFFER_F_GSO)
  	    ip1_len = gso_mtu_sz (p1);
  
  
  
  	  ip6_mtu_check (p0, ip0_len,
  			 adj0[0].rewrite_header.max_l3_packet_bytes,
  			 is_locally_originated0, &next0, is_midchain,
  			 &error0);
  	  ip6_mtu_check (p1, ip1_len,
  			 adj1[0].rewrite_header.max_l3_packet_bytes,
  			 is_locally_originated1, &next1, is_midchain,
  			 &error1);
  
  	  /* Don't adjust the buffer for hop count issue; icmp-error node
  	   * wants to see the IP header */
  	  if (PREDICT_TRUE (error0 == IP6_ERROR_NONE))
  	    {
  	      p0->current_data -= rw_len0;
  	      p0->current_length += rw_len0;
  
  	      tx_sw_if_index0 = adj0[0].rewrite_header.sw_if_index;
  	      vnet_buffer (p0)->sw_if_index[VLIB_TX] = tx_sw_if_index0;
  	      next0 = adj0[0].rewrite_header.next_index;
  
  	      if (PREDICT_FALSE
  		  (adj0[0].rewrite_header.flags & VNET_REWRITE_HAS_FEATURES))
  		vnet_feature_arc_start_w_cfg_index
  		  (lm->output_feature_arc_index, tx_sw_if_index0, &next0, p0,
  		   adj0->ia_cfg_index);
  	    }
  	  else
  	    {
  	      p0->error = error_node->errors[error0];
  	    }
  	  if (PREDICT_TRUE (error1 == IP6_ERROR_NONE))
  	    {
  	      p1->current_data -= rw_len1;
  	      p1->current_length += rw_len1;
  
  	      tx_sw_if_index1 = adj1[0].rewrite_header.sw_if_index;
  	      vnet_buffer (p1)->sw_if_index[VLIB_TX] = tx_sw_if_index1;
  	      next1 = adj1[0].rewrite_header.next_index;
  
  	      if (PREDICT_FALSE
  		  (adj1[0].rewrite_header.flags & VNET_REWRITE_HAS_FEATURES))
  		vnet_feature_arc_start_w_cfg_index
  		  (lm->output_feature_arc_index, tx_sw_if_index1, &next1, p1,
  		   adj1->ia_cfg_index);
  	    }
  	  else
  	    {
  	      p1->error = error_node->errors[error1];
  	    }
  
  	  if (is_midchain)
  	    {
  	      /* before we paint on the next header, update the L4
  	       * checksums if required, since there's no offload on a tunnel */
  	      vnet_calc_checksums_inline (vm, p0, 0 /* is_ip4 */ ,
  					  1 /* is_ip6 */ );
  	      vnet_calc_checksums_inline (vm, p1, 0 /* is_ip4 */ ,
  					  1 /* is_ip6 */ );
  
  	      /* Guess we are only writing on ipv6 header. */
  	      vnet_rewrite_two_headers (adj0[0], adj1[0],
  					ip0, ip1, sizeof (ip6_header_t));
  	    }
  	  else
  	    /* Guess we are only writing on simple Ethernet header. */
  	    vnet_rewrite_two_headers (adj0[0], adj1[0],
  				      ip0, ip1, sizeof (ethernet_header_t));
  
  	  if (is_midchain)
  	    {
  	      if (adj0->sub_type.midchain.fixup_func)
  		adj0->sub_type.midchain.fixup_func
  		  (vm, adj0, p0, adj0->sub_type.midchain.fixup_data);
  	      if (adj1->sub_type.midchain.fixup_func)
  		adj1->sub_type.midchain.fixup_func
  		  (vm, adj1, p1, adj1->sub_type.midchain.fixup_data);
  	    }
  	  if (is_mcast)
  	    {
  	      /*
  	       * copy bytes from the IP address into the MAC rewrite
  	       */
  	      vnet_ip_mcast_fixup_header (IP6_MCAST_ADDR_MASK,
  					  adj0->
  					  rewrite_header.dst_mcast_offset,
  					  &ip0->dst_address.as_u32[3],
  					  (u8 *) ip0);
  	      vnet_ip_mcast_fixup_header (IP6_MCAST_ADDR_MASK,
  					  adj1->
  					  rewrite_header.dst_mcast_offset,
  					  &ip1->dst_address.as_u32[3],
  					  (u8 *) ip1);
  	    }
  
  	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
  					   to_next, n_left_to_next,
  					   pi0, pi1, next0, next1);
  	}
  
        while (n_left_from > 0 && n_left_to_next > 0)
  	{
  	  ip_adjacency_t *adj0;
  	  vlib_buffer_t *p0;
  	  ip6_header_t *ip0;
  	  u32 pi0, rw_len0;
  	  u32 adj_index0, next0, error0;
  	  u32 tx_sw_if_index0;
  	  bool is_locally_originated0;
  
  	  pi0 = to_next[0] = from[0];
  
  	  p0 = vlib_get_buffer (vm, pi0);
  
  	  adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
  
  	  adj0 = adj_get (adj_index0);
  
  	  ip0 = vlib_buffer_get_current (p0);
  
  	  error0 = IP6_ERROR_NONE;
  	  next0 = IP6_REWRITE_NEXT_DROP;
  
  	  /* Check hop limit */
  	  is_locally_originated0 =
  	    p0->flags & VNET_BUFFER_F_LOCALLY_ORIGINATED;
  	  if (PREDICT_TRUE (!is_locally_originated0))
  	    {
  	      i32 hop_limit0 = ip0->hop_limit;
  
  	      ASSERT (ip0->hop_limit > 0);
  
  	      hop_limit0 -= 1;
  
  	      ip0->hop_limit = hop_limit0;
  
  	      if (PREDICT_FALSE (hop_limit0 <= 0))
  		{
  		  /*
  		   * If the hop count drops below 1 when forwarding, generate
  		   * an ICMP response.
  		   */
  		  error0 = IP6_ERROR_TIME_EXPIRED;
  		  next0 = IP6_REWRITE_NEXT_ICMP_ERROR;
  		  vnet_buffer (p0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
  		  icmp6_error_set_vnet_buffer (p0, ICMP6_time_exceeded,
  					       ICMP6_time_exceeded_ttl_exceeded_in_transit,
  					       0);
  		}
  	    }
  
  	  if (is_midchain)
  	    {
  	      vnet_calc_checksums_inline (vm, p0, 0 /* is_ip4 */ ,
  					  1 /* is_ip6 */ );
  
  	      /* Guess we are only writing on ip6 header. */
  	      vnet_rewrite_one_header (adj0[0], ip0, sizeof (ip6_header_t));
  	    }
  	  else
  	    /* Guess we are only writing on simple Ethernet header. */
  	    vnet_rewrite_one_header (adj0[0], ip0,
  				     sizeof (ethernet_header_t));
  
  	  /* Update packet buffer attributes/set output interface. */
  	  rw_len0 = adj0[0].rewrite_header.data_bytes;
  	  vnet_buffer (p0)->ip.save_rewrite_length = 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. */
  	  u16 ip0_len =
  	    clib_net_to_host_u16 (ip0->payload_length) +
  	    sizeof (ip6_header_t);
  	  if (p0->flags & VNET_BUFFER_F_GSO)
  	    ip0_len = gso_mtu_sz (p0);
  
  	  ip6_mtu_check (p0, ip0_len,
  			 adj0[0].rewrite_header.max_l3_packet_bytes,
  			 is_locally_originated0, &next0, is_midchain,
  			 &error0);
  
  	  /* Don't adjust the buffer for hop count issue; icmp-error node
  	   * wants to see the IP header */
  	  if (PREDICT_TRUE (error0 == IP6_ERROR_NONE))
  	    {
  	      p0->current_data -= rw_len0;
  	      p0->current_length += rw_len0;
  
  	      tx_sw_if_index0 = adj0[0].rewrite_header.sw_if_index;
  
  	      vnet_buffer (p0)->sw_if_index[VLIB_TX] = tx_sw_if_index0;
  	      next0 = adj0[0].rewrite_header.next_index;
  
  	      if (PREDICT_FALSE
  		  (adj0[0].rewrite_header.flags & VNET_REWRITE_HAS_FEATURES))
  		vnet_feature_arc_start_w_cfg_index
  		  (lm->output_feature_arc_index, tx_sw_if_index0, &next0, p0,
  		   adj0->ia_cfg_index);
  	    }
  	  else
  	    {
  	      p0->error = error_node->errors[error0];
  	    }
  
  	  if (is_midchain)
  	    {
  	      if (adj0->sub_type.midchain.fixup_func)
  		adj0->sub_type.midchain.fixup_func
  		  (vm, adj0, p0, adj0->sub_type.midchain.fixup_data);
  	    }
  	  if (is_mcast)
  	    {
  	      vnet_ip_mcast_fixup_header (IP6_MCAST_ADDR_MASK,
  					  adj0->
  					  rewrite_header.dst_mcast_offset,
  					  &ip0->dst_address.as_u32[3],
  					  (u8 *) ip0);
  	    }
  
  	  from += 1;
  	  n_left_from -= 1;
  	  to_next += 1;
  	  n_left_to_next -= 1;
  
  	  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);
      }
  
    /* Need to do trace after rewrites to pick up new packet data. */
    if (node->flags & VLIB_NODE_FLAG_TRACE)
      ip6_forward_next_trace (vm, node, frame, VLIB_TX);
  
    return frame->n_vectors;
  }
  
  always_inline uword
  ip6_rewrite_inline (vlib_main_t * vm,
  		    vlib_node_runtime_t * node,
  		    vlib_frame_t * frame,
  		    int do_counters, int is_midchain, int is_mcast)
  {
    return ip6_rewrite_inline_with_gso (vm, node, frame, do_counters,
  				      is_midchain, is_mcast);
  }
  
  VLIB_NODE_FN (ip6_rewrite_node) (vlib_main_t * vm,
  				 vlib_node_runtime_t * node,
  				 vlib_frame_t * frame)
  {
    if (adj_are_counters_enabled ())
      return ip6_rewrite_inline (vm, node, frame, 1, 0, 0);
    else
      return ip6_rewrite_inline (vm, node, frame, 0, 0, 0);
  }
  
  VLIB_NODE_FN (ip6_rewrite_bcast_node) (vlib_main_t * vm,
  				       vlib_node_runtime_t * node,
  				       vlib_frame_t * frame)
  {
    if (adj_are_counters_enabled ())
      return ip6_rewrite_inline (vm, node, frame, 1, 0, 0);
    else
      return ip6_rewrite_inline (vm, node, frame, 0, 0, 0);
  }
  
  VLIB_NODE_FN (ip6_rewrite_mcast_node) (vlib_main_t * vm,
  				       vlib_node_runtime_t * node,
  				       vlib_frame_t * frame)
  {
    if (adj_are_counters_enabled ())
      return ip6_rewrite_inline (vm, node, frame, 1, 0, 1);
    else
      return ip6_rewrite_inline (vm, node, frame, 0, 0, 1);
  }
  
  VLIB_NODE_FN (ip6_midchain_node) (vlib_main_t * vm,
  				  vlib_node_runtime_t * node,
  				  vlib_frame_t * frame)
  {
    if (adj_are_counters_enabled ())
      return ip6_rewrite_inline (vm, node, frame, 1, 1, 0);
    else
      return ip6_rewrite_inline (vm, node, frame, 0, 1, 0);
  }
  
  VLIB_NODE_FN (ip6_mcast_midchain_node) (vlib_main_t * vm,
  					vlib_node_runtime_t * node,
  					vlib_frame_t * frame)
  {
    if (adj_are_counters_enabled ())
      return ip6_rewrite_inline (vm, node, frame, 1, 1, 1);
    else
      return ip6_rewrite_inline (vm, node, frame, 0, 1, 1);
  }
  
  /* *INDENT-OFF* */
  VLIB_REGISTER_NODE (ip6_midchain_node) =
  {
    .name = "ip6-midchain",
    .vector_size = sizeof (u32),
    .format_trace = format_ip6_forward_next_trace,
    .sibling_of = "ip6-rewrite",
    };
  
  VLIB_REGISTER_NODE (ip6_rewrite_node) =
  {
    .name = "ip6-rewrite",
    .vector_size = sizeof (u32),
    .format_trace = format_ip6_rewrite_trace,
    .n_next_nodes = IP6_REWRITE_N_NEXT,
    .next_nodes =
    {
      [IP6_REWRITE_NEXT_DROP] = "ip6-drop",
      [IP6_REWRITE_NEXT_ICMP_ERROR] = "ip6-icmp-error",
      [IP6_REWRITE_NEXT_FRAGMENT] = "ip6-frag",
    },
  };
  
  VLIB_REGISTER_NODE (ip6_rewrite_bcast_node) = {
    .name = "ip6-rewrite-bcast",
    .vector_size = sizeof (u32),
  
    .format_trace = format_ip6_rewrite_trace,
    .sibling_of = "ip6-rewrite",
  };
  
  VLIB_REGISTER_NODE (ip6_rewrite_mcast_node) =
  {
    .name = "ip6-rewrite-mcast",
    .vector_size = sizeof (u32),
    .format_trace = format_ip6_rewrite_trace,
    .sibling_of = "ip6-rewrite",
  };
  
  
  VLIB_REGISTER_NODE (ip6_mcast_midchain_node) =
  {
    .name = "ip6-mcast-midchain",
    .vector_size = sizeof (u32),
    .format_trace = format_ip6_rewrite_trace,
    .sibling_of = "ip6-rewrite",
  };
  
  /* *INDENT-ON* */
  
  /*
   * Hop-by-Hop handling
   */
  #ifndef CLIB_MARCH_VARIANT
  ip6_hop_by_hop_main_t ip6_hop_by_hop_main;
  #endif /* CLIB_MARCH_VARIANT */
  
  #define foreach_ip6_hop_by_hop_error \
  _(PROCESSED, "pkts with ip6 hop-by-hop options") \
  _(FORMAT, "incorrectly formatted hop-by-hop options") \
  _(UNKNOWN_OPTION, "unknown ip6 hop-by-hop options")
  
  /* *INDENT-OFF* */
  typedef enum
  {
  #define _(sym,str) IP6_HOP_BY_HOP_ERROR_##sym,
    foreach_ip6_hop_by_hop_error
  #undef _
    IP6_HOP_BY_HOP_N_ERROR,
  } ip6_hop_by_hop_error_t;
  /* *INDENT-ON* */
  
  /*
   * Primary h-b-h handler trace support
   * We work pretty hard on the problem for obvious reasons
   */
  typedef struct
  {
    u32 next_index;
    u32 trace_len;
    u8 option_data[256];
  } ip6_hop_by_hop_trace_t;
  
  extern vlib_node_registration_t ip6_hop_by_hop_node;
  
  static char *ip6_hop_by_hop_error_strings[] = {
  #define _(sym,string) string,
    foreach_ip6_hop_by_hop_error
  #undef _
  };
  
  #ifndef CLIB_MARCH_VARIANT
  u8 *
  format_ip6_hop_by_hop_ext_hdr (u8 * s, va_list * args)
  {
    ip6_hop_by_hop_header_t *hbh0 = va_arg (*args, ip6_hop_by_hop_header_t *);
    int total_len = va_arg (*args, int);
    ip6_hop_by_hop_option_t *opt0, *limit0;
    ip6_hop_by_hop_main_t *hm = &ip6_hop_by_hop_main;
    u8 type0;
  
    s = format (s, "IP6_HOP_BY_HOP: next protocol %d len %d total %d",
  	      hbh0->protocol, (hbh0->length + 1) << 3, total_len);
  
    opt0 = (ip6_hop_by_hop_option_t *) (hbh0 + 1);
    limit0 = (ip6_hop_by_hop_option_t *) ((u8 *) hbh0 + total_len);
  
    while (opt0 < limit0)
      {
        type0 = opt0->type;
        switch (type0)
  	{
  	case 0:		/* Pad, just stop */
  	  opt0 = (ip6_hop_by_hop_option_t *) ((u8 *) opt0 + 1);
  	  break;
  
  	default:
  	  if (hm->trace[type0])
  	    {
  	      s = (*hm->trace[type0]) (s, opt0);
  	    }
  	  else
  	    {
  	      s =
  		format (s, "\n    unrecognized option %d length %d", type0,
  			opt0->length);
  	    }
  	  opt0 =
  	    (ip6_hop_by_hop_option_t *) (((u8 *) opt0) + opt0->length +
  					 sizeof (ip6_hop_by_hop_option_t));
  	  break;
  	}
      }
    return s;
  }
  #endif
  
  static u8 *
  format_ip6_hop_by_hop_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 *);
    ip6_hop_by_hop_trace_t *t = va_arg (*args, ip6_hop_by_hop_trace_t *);
    ip6_hop_by_hop_header_t *hbh0;
    ip6_hop_by_hop_option_t *opt0, *limit0;
    ip6_hop_by_hop_main_t *hm = &ip6_hop_by_hop_main;
  
    u8 type0;
  
    hbh0 = (ip6_hop_by_hop_header_t *) t->option_data;
  
    s = format (s, "IP6_HOP_BY_HOP: next index %d len %d traced %d",
  	      t->next_index, (hbh0->length + 1) << 3, t->trace_len);
  
    opt0 = (ip6_hop_by_hop_option_t *) (hbh0 + 1);
    limit0 = (ip6_hop_by_hop_option_t *) ((u8 *) hbh0) + t->trace_len;
  
    while (opt0 < limit0)
      {
        type0 = opt0->type;
        switch (type0)
  	{
  	case 0:		/* Pad, just stop */
  	  opt0 = (ip6_hop_by_hop_option_t *) ((u8 *) opt0) + 1;
  	  break;
  
  	default:
  	  if (hm->trace[type0])
  	    {
  	      s = (*hm->trace[type0]) (s, opt0);
  	    }
  	  else
  	    {
  	      s =
  		format (s, "\n    unrecognized option %d length %d", type0,
  			opt0->length);
  	    }
  	  opt0 =
  	    (ip6_hop_by_hop_option_t *) (((u8 *) opt0) + opt0->length +
  					 sizeof (ip6_hop_by_hop_option_t));
  	  break;
  	}
      }
    return s;
  }
  
  always_inline u8
  ip6_scan_hbh_options (vlib_buffer_t * b0,
  		      ip6_header_t * ip0,
  		      ip6_hop_by_hop_header_t * hbh0,
  		      ip6_hop_by_hop_option_t * opt0,
  		      ip6_hop_by_hop_option_t * limit0, u32 * next0)
  {
    ip6_hop_by_hop_main_t *hm = &ip6_hop_by_hop_main;
    u8 type0;
    u8 error0 = 0;
  
    while (opt0 < limit0)
      {
        type0 = opt0->type;
        switch (type0)
  	{
  	case 0:		/* Pad1 */
  	  opt0 = (ip6_hop_by_hop_option_t *) ((u8 *) opt0) + 1;
  	  continue;
  	case 1:		/* PadN */
  	  break;
  	default:
  	  if (hm->options[type0])
  	    {
  	      if ((*hm->options[type0]) (b0, ip0, opt0) < 0)
  		{
  		  error0 = IP6_HOP_BY_HOP_ERROR_FORMAT;
  		  return (error0);
  		}
  	    }
  	  else
  	    {
  	      /* Unrecognized mandatory option, check the two high order bits */
  	      switch (opt0->type & HBH_OPTION_TYPE_HIGH_ORDER_BITS)
  		{
  		case HBH_OPTION_TYPE_SKIP_UNKNOWN:
  		  break;
  		case HBH_OPTION_TYPE_DISCARD_UNKNOWN:
  		  error0 = IP6_HOP_BY_HOP_ERROR_UNKNOWN_OPTION;
  		  *next0 = IP_LOOKUP_NEXT_DROP;
  		  break;
  		case HBH_OPTION_TYPE_DISCARD_UNKNOWN_ICMP:
  		  error0 = IP6_HOP_BY_HOP_ERROR_UNKNOWN_OPTION;
  		  *next0 = IP_LOOKUP_NEXT_ICMP_ERROR;
  		  icmp6_error_set_vnet_buffer (b0, ICMP6_parameter_problem,
  					       ICMP6_parameter_problem_unrecognized_option,
  					       (u8 *) opt0 - (u8 *) ip0);
  		  break;
  		case HBH_OPTION_TYPE_DISCARD_UNKNOWN_ICMP_NOT_MCAST:
  		  error0 = IP6_HOP_BY_HOP_ERROR_UNKNOWN_OPTION;
  		  if (!ip6_address_is_multicast (&ip0->dst_address))
  		    {
  		      *next0 = IP_LOOKUP_NEXT_ICMP_ERROR;
  		      icmp6_error_set_vnet_buffer (b0,
  						   ICMP6_parameter_problem,
  						   ICMP6_parameter_problem_unrecognized_option,
  						   (u8 *) opt0 - (u8 *) ip0);
  		    }
  		  else
  		    {
  		      *next0 = IP_LOOKUP_NEXT_DROP;
  		    }
  		  break;
  		}
  	      return (error0);
  	    }
  	}
        opt0 =
  	(ip6_hop_by_hop_option_t *) (((u8 *) opt0) + opt0->length +
  				     sizeof (ip6_hop_by_hop_option_t));
      }
    return (error0);
  }
  
  /*
   * Process the Hop-by-Hop Options header
   */
  VLIB_NODE_FN (ip6_hop_by_hop_node) (vlib_main_t * vm,
  				    vlib_node_runtime_t * node,
  				    vlib_frame_t * frame)
  {
    vlib_node_runtime_t *error_node =
      vlib_node_get_runtime (vm, ip6_hop_by_hop_node.index);
    ip6_hop_by_hop_main_t *hm = &ip6_hop_by_hop_main;
    u32 n_left_from, *from, *to_next;
    ip_lookup_next_t next_index;
  
    from = vlib_frame_vector_args (frame);
    n_left_from = frame->n_vectors;
    next_index = node->cached_next_index;
  
    while (n_left_from > 0)
      {
        u32 n_left_to_next;
  
        vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
  
        while (n_left_from >= 4 && n_left_to_next >= 2)
  	{
  	  u32 bi0, bi1;
  	  vlib_buffer_t *b0, *b1;
  	  u32 next0, next1;
  	  ip6_header_t *ip0, *ip1;
  	  ip6_hop_by_hop_header_t *hbh0, *hbh1;
  	  ip6_hop_by_hop_option_t *opt0, *limit0, *opt1, *limit1;
  	  u8 error0 = 0, error1 = 0;
  
  	  /* Prefetch next iteration. */
  	  {
  	    vlib_buffer_t *p2, *p3;
  
  	    p2 = vlib_get_buffer (vm, from[2]);
  	    p3 = vlib_get_buffer (vm, from[3]);
  
  	    vlib_prefetch_buffer_header (p2, LOAD);
  	    vlib_prefetch_buffer_header (p3, LOAD);
  
  	    CLIB_PREFETCH (p2->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
  	    CLIB_PREFETCH (p3->data, 2 * CLIB_CACHE_LINE_BYTES, LOAD);
  	  }
  
  	  /* Speculatively enqueue b0, b1 to the current next frame */
  	  to_next[0] = bi0 = from[0];
  	  to_next[1] = bi1 = from[1];
  	  from += 2;
  	  to_next += 2;
  	  n_left_from -= 2;
  	  n_left_to_next -= 2;
  
  	  b0 = vlib_get_buffer (vm, bi0);
  	  b1 = vlib_get_buffer (vm, bi1);
  
  	  /* Default use the next_index from the adjacency. A HBH option rarely redirects to a different node */
  	  u32 adj_index0 = vnet_buffer (b0)->ip.adj_index[VLIB_TX];
  	  ip_adjacency_t *adj0 = adj_get (adj_index0);
  	  u32 adj_index1 = vnet_buffer (b1)->ip.adj_index[VLIB_TX];
  	  ip_adjacency_t *adj1 = adj_get (adj_index1);
  
  	  /* Default use the next_index from the adjacency. A HBH option rarely redirects to a different node */
  	  next0 = adj0->lookup_next_index;
  	  next1 = adj1->lookup_next_index;
  
  	  ip0 = vlib_buffer_get_current (b0);
  	  ip1 = vlib_buffer_get_current (b1);
  	  hbh0 = (ip6_hop_by_hop_header_t *) (ip0 + 1);
  	  hbh1 = (ip6_hop_by_hop_header_t *) (ip1 + 1);
  	  opt0 = (ip6_hop_by_hop_option_t *) (hbh0 + 1);
  	  opt1 = (ip6_hop_by_hop_option_t *) (hbh1 + 1);
  	  limit0 =
  	    (ip6_hop_by_hop_option_t *) ((u8 *) hbh0 +
  					 ((hbh0->length + 1) << 3));
  	  limit1 =
  	    (ip6_hop_by_hop_option_t *) ((u8 *) hbh1 +
  					 ((hbh1->length + 1) << 3));
  
  	  /*
  	   * Basic validity checks
  	   */
  	  if ((hbh0->length + 1) << 3 >
  	      clib_net_to_host_u16 (ip0->payload_length))
  	    {
  	      error0 = IP6_HOP_BY_HOP_ERROR_FORMAT;
  	      next0 = IP_LOOKUP_NEXT_DROP;
  	      goto outdual;
  	    }
  	  /* Scan the set of h-b-h options, process ones that we understand */
  	  error0 = ip6_scan_hbh_options (b0, ip0, hbh0, opt0, limit0, &next0);
  
  	  if ((hbh1->length + 1) << 3 >
  	      clib_net_to_host_u16 (ip1->payload_length))
  	    {
  	      error1 = IP6_HOP_BY_HOP_ERROR_FORMAT;
  	      next1 = IP_LOOKUP_NEXT_DROP;
  	      goto outdual;
  	    }
  	  /* Scan the set of h-b-h options, process ones that we understand */
  	  error1 = ip6_scan_hbh_options (b1, ip1, hbh1, opt1, limit1, &next1);
  
  	outdual:
  	  /* Has the classifier flagged this buffer for special treatment? */
  	  if (PREDICT_FALSE
  	      ((error0 == 0)
  	       && (vnet_buffer (b0)->l2_classify.opaque_index & OI_DECAP)))
  	    next0 = hm->next_override;
  
  	  /* Has the classifier flagged this buffer for special treatment? */
  	  if (PREDICT_FALSE
  	      ((error1 == 0)
  	       && (vnet_buffer (b1)->l2_classify.opaque_index & OI_DECAP)))
  	    next1 = hm->next_override;
  
  	  if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
  	    {
  	      if (b0->flags & VLIB_BUFFER_IS_TRACED)
  		{
  		  ip6_hop_by_hop_trace_t *t =
  		    vlib_add_trace (vm, node, b0, sizeof (*t));
  		  u32 trace_len = (hbh0->length + 1) << 3;
  		  t->next_index = next0;
  		  /* Capture the h-b-h option verbatim */
  		  trace_len =
  		    trace_len <
  		    ARRAY_LEN (t->option_data) ? trace_len :
  		    ARRAY_LEN (t->option_data);
  		  t->trace_len = trace_len;
  		  clib_memcpy_fast (t->option_data, hbh0, trace_len);
  		}
  	      if (b1->flags & VLIB_BUFFER_IS_TRACED)
  		{
  		  ip6_hop_by_hop_trace_t *t =
  		    vlib_add_trace (vm, node, b1, sizeof (*t));
  		  u32 trace_len = (hbh1->length + 1) << 3;
  		  t->next_index = next1;
  		  /* Capture the h-b-h option verbatim */
  		  trace_len =
  		    trace_len <
  		    ARRAY_LEN (t->option_data) ? trace_len :
  		    ARRAY_LEN (t->option_data);
  		  t->trace_len = trace_len;
  		  clib_memcpy_fast (t->option_data, hbh1, trace_len);
  		}
  
  	    }
  
  	  b0->error = error_node->errors[error0];
  	  b1->error = error_node->errors[error1];
  
  	  /* verify speculative enqueue, maybe switch current next frame */
  	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next,
  					   n_left_to_next, bi0, bi1, next0,
  					   next1);
  	}
  
        while (n_left_from > 0 && n_left_to_next > 0)
  	{
  	  u32 bi0;
  	  vlib_buffer_t *b0;
  	  u32 next0;
  	  ip6_header_t *ip0;
  	  ip6_hop_by_hop_header_t *hbh0;
  	  ip6_hop_by_hop_option_t *opt0, *limit0;
  	  u8 error0 = 0;
  
  	  /* Speculatively enqueue b0 to the current next frame */
  	  bi0 = from[0];
  	  to_next[0] = bi0;
  	  from += 1;
  	  to_next += 1;
  	  n_left_from -= 1;
  	  n_left_to_next -= 1;
  
  	  b0 = vlib_get_buffer (vm, bi0);
  	  /*
  	   * Default use the next_index from the adjacency.
  	   * A HBH option rarely redirects to a different node
  	   */
  	  u32 adj_index0 = vnet_buffer (b0)->ip.adj_index[VLIB_TX];
  	  ip_adjacency_t *adj0 = adj_get (adj_index0);
  	  next0 = adj0->lookup_next_index;
  
  	  ip0 = vlib_buffer_get_current (b0);
  	  hbh0 = (ip6_hop_by_hop_header_t *) (ip0 + 1);
  	  opt0 = (ip6_hop_by_hop_option_t *) (hbh0 + 1);
  	  limit0 =
  	    (ip6_hop_by_hop_option_t *) ((u8 *) hbh0 +
  					 ((hbh0->length + 1) << 3));
  
  	  /*
  	   * Basic validity checks
  	   */
  	  if ((hbh0->length + 1) << 3 >
  	      clib_net_to_host_u16 (ip0->payload_length))
  	    {
  	      error0 = IP6_HOP_BY_HOP_ERROR_FORMAT;
  	      next0 = IP_LOOKUP_NEXT_DROP;
  	      goto out0;
  	    }
  
  	  /* Scan the set of h-b-h options, process ones that we understand */
  	  error0 = ip6_scan_hbh_options (b0, ip0, hbh0, opt0, limit0, &next0);
  
  	out0:
  	  /* Has the classifier flagged this buffer for special treatment? */
  	  if (PREDICT_FALSE
  	      ((error0 == 0)
  	       && (vnet_buffer (b0)->l2_classify.opaque_index & OI_DECAP)))
  	    next0 = hm->next_override;
  
  	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
  	    {
  	      ip6_hop_by_hop_trace_t *t =
  		vlib_add_trace (vm, node, b0, sizeof (*t));
  	      u32 trace_len = (hbh0->length + 1) << 3;
  	      t->next_index = next0;
  	      /* Capture the h-b-h option verbatim */
  	      trace_len =
  		trace_len <
  		ARRAY_LEN (t->option_data) ? trace_len :
  		ARRAY_LEN (t->option_data);
  	      t->trace_len = trace_len;
  	      clib_memcpy_fast (t->option_data, hbh0, trace_len);
  	    }
  
  	  b0->error = error_node->errors[error0];
  
  	  /* verify speculative enqueue, maybe switch current next frame */
  	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
  					   n_left_to_next, bi0, next0);
  	}
        vlib_put_next_frame (vm, node, next_index, n_left_to_next);
      }
    return frame->n_vectors;
  }
  
  /* *INDENT-OFF* */
  VLIB_REGISTER_NODE (ip6_hop_by_hop_node) =
  {
    .name = "ip6-hop-by-hop",
    .sibling_of = "ip6-lookup",
    .vector_size = sizeof (u32),
    .format_trace = format_ip6_hop_by_hop_trace,
    .type = VLIB_NODE_TYPE_INTERNAL,
    .n_errors = ARRAY_LEN (ip6_hop_by_hop_error_strings),
    .error_strings = ip6_hop_by_hop_error_strings,
    .n_next_nodes = 0,
  };
  /* *INDENT-ON* */
  
  static clib_error_t *
  ip6_hop_by_hop_init (vlib_main_t * vm)
  {
    ip6_hop_by_hop_main_t *hm = &ip6_hop_by_hop_main;
    clib_memset (hm->options, 0, sizeof (hm->options));
    clib_memset (hm->trace, 0, sizeof (hm->trace));
    hm->next_override = IP6_LOOKUP_NEXT_POP_HOP_BY_HOP;
    return (0);
  }
  
  VLIB_INIT_FUNCTION (ip6_hop_by_hop_init);
  
  #ifndef CLIB_MARCH_VARIANT
  void
  ip6_hbh_set_next_override (uword next)
  {
    ip6_hop_by_hop_main_t *hm = &ip6_hop_by_hop_main;
  
    hm->next_override = next;
  }
  
  int
  ip6_hbh_register_option (u8 option,
  			 int options (vlib_buffer_t * b, ip6_header_t * ip,
  				      ip6_hop_by_hop_option_t * opt),
  			 u8 * trace (u8 * s, ip6_hop_by_hop_option_t * opt))
  {
    ip6_main_t *im = &ip6_main;
    ip6_hop_by_hop_main_t *hm = &ip6_hop_by_hop_main;
  
    ASSERT ((u32) option < ARRAY_LEN (hm->options));
  
    /* Already registered */
    if (hm->options[option])
      return (-1);
  
    hm->options[option] = options;
    hm->trace[option] = trace;
  
    /* Set global variable */
    im->hbh_enabled = 1;
  
    return (0);
  }
  
  int
  ip6_hbh_unregister_option (u8 option)
  {
    ip6_main_t *im = &ip6_main;
    ip6_hop_by_hop_main_t *hm = &ip6_hop_by_hop_main;
  
    ASSERT ((u32) option < ARRAY_LEN (hm->options));
  
    /* Not registered */
    if (!hm->options[option])
      return (-1);
  
    hm->options[option] = NULL;
    hm->trace[option] = NULL;
  
    /* Disable global knob if this was the last option configured */
    int i;
    bool found = false;
    for (i = 0; i < 256; i++)
      {
        if (hm->options[option])
  	{
  	  found = true;
  	  break;
  	}
      }
    if (!found)
      im->hbh_enabled = 0;
  
    return (0);
  }
  
  /* Global IP6 main. */
  ip6_main_t ip6_main;
  #endif
  
  static clib_error_t *
  ip6_lookup_init (vlib_main_t * vm)
  {
    ip6_main_t *im = &ip6_main;
    clib_error_t *error;
    uword i;
  
    if ((error = vlib_call_init_function (vm, vnet_feature_init)))
      return error;
  
    for (i = 0; i < ARRAY_LEN (im->fib_masks); i++)
      {
        u32 j, i0, i1;
  
        i0 = i / 32;
        i1 = i % 32;
  
        for (j = 0; j < i0; j++)
  	im->fib_masks[i].as_u32[j] = ~0;
  
        if (i1)
  	im->fib_masks[i].as_u32[i0] =
  	  clib_host_to_net_u32 (pow2_mask (i1) << (32 - i1));
      }
  
    ip_lookup_init (&im->lookup_main, /* is_ip6 */ 1);
  
    /* Create FIB with index 0 and table id of 0. */
    fib_table_find_or_create_and_lock (FIB_PROTOCOL_IP6, 0,
  				     FIB_SOURCE_DEFAULT_ROUTE);
    mfib_table_find_or_create_and_lock (FIB_PROTOCOL_IP6, 0,
  				      MFIB_SOURCE_DEFAULT_ROUTE);
  
    {
      pg_node_t *pn;
      pn = pg_get_node (ip6_lookup_node.index);
      pn->unformat_edit = unformat_pg_ip6_header;
    }
  
    /* Unless explicitly configured, don't process HBH options */
    im->hbh_enabled = 0;
  
    return error;
  }
  
  VLIB_INIT_FUNCTION (ip6_lookup_init);
  
  #ifndef CLIB_MARCH_VARIANT
  int
  vnet_set_ip6_flow_hash (u32 table_id, u32 flow_hash_config)
  {
    u32 fib_index;
  
    fib_index = fib_table_find (FIB_PROTOCOL_IP6, table_id);
  
    if (~0 == fib_index)
      return VNET_API_ERROR_NO_SUCH_FIB;
  
    fib_table_set_flow_hash_config (fib_index, FIB_PROTOCOL_IP6,
  				  flow_hash_config);
  
    return 0;
  }
  #endif
  
  static clib_error_t *
  set_ip6_flow_hash_command_fn (vlib_main_t * vm,
  			      unformat_input_t * input,
  			      vlib_cli_command_t * cmd)
  {
    int matched = 0;
    u32 table_id = 0;
    u32 flow_hash_config = 0;
    int rv;
  
    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
      {
        if (unformat (input, "table %d", &table_id))
  	matched = 1;
  #define _(a,v) \
      else if (unformat (input, #a)) { flow_hash_config |= v; matched=1;}
        foreach_flow_hash_bit
  #undef _
  	else
  	break;
      }
  
    if (matched == 0)
      return clib_error_return (0, "unknown input `%U'",
  			      format_unformat_error, input);
  
    rv = vnet_set_ip6_flow_hash (table_id, flow_hash_config);
    switch (rv)
      {
      case 0:
        break;
  
      case -1:
        return clib_error_return (0, "no such FIB table %d", table_id);
  
      default:
        clib_warning ("BUG: illegal flow hash config 0x%x", flow_hash_config);
        break;
      }
  
    return 0;
  }
  
  /*?
   * Configure the set of IPv6 fields used by the flow hash.
   *
   * @cliexpar
   * @parblock
   * Example of how to set the flow hash on a given table:
   * @cliexcmd{set ip6 flow-hash table 8 dst sport dport proto}
   *
   * Example of display the configured flow hash:
   * @cliexstart{show ip6 fib}
   * ipv6-VRF:0, fib_index 0, flow hash: src dst sport dport proto
   * @::/0
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:5 buckets:1 uRPF:5 to:[0:0]]
   *     [0] [@0]: dpo-drop ip6
   * fe80::/10
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:10 buckets:1 uRPF:10 to:[0:0]]
   *     [0] [@2]: dpo-receive
   * ff02::1/128
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:8 buckets:1 uRPF:8 to:[0:0]]
   *     [0] [@2]: dpo-receive
   * ff02::2/128
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:7 buckets:1 uRPF:7 to:[0:0]]
   *     [0] [@2]: dpo-receive
   * ff02::16/128
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:9 buckets:1 uRPF:9 to:[0:0]]
   *     [0] [@2]: dpo-receive
   * ff02::1:ff00:0/104
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:6 buckets:1 uRPF:6 to:[0:0]]
   *     [0] [@2]: dpo-receive
   * ipv6-VRF:8, fib_index 1, flow hash: dst sport dport proto
   * @::/0
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:21 buckets:1 uRPF:20 to:[0:0]]
   *     [0] [@0]: dpo-drop ip6
   * @::a:1:1:0:4/126
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:27 buckets:1 uRPF:26 to:[0:0]]
   *     [0] [@4]: ipv6-glean: af_packet0
   * @::a:1:1:0:7/128
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:28 buckets:1 uRPF:27 to:[0:0]]
   *     [0] [@2]: dpo-receive: @::a:1:1:0:7 on af_packet0
   * fe80::/10
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:26 buckets:1 uRPF:25 to:[0:0]]
   *     [0] [@2]: dpo-receive
   * fe80::fe:3eff:fe3e:9222/128
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:29 buckets:1 uRPF:28 to:[0:0]]
   *     [0] [@2]: dpo-receive: fe80::fe:3eff:fe3e:9222 on af_packet0
   * ff02::1/128
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:24 buckets:1 uRPF:23 to:[0:0]]
   *     [0] [@2]: dpo-receive
   * ff02::2/128
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:23 buckets:1 uRPF:22 to:[0:0]]
   *     [0] [@2]: dpo-receive
   * ff02::16/128
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:25 buckets:1 uRPF:24 to:[0:0]]
   *     [0] [@2]: dpo-receive
   * ff02::1:ff00:0/104
   *   unicast-ip6-chain
   *   [@0]: dpo-load-balance: [index:22 buckets:1 uRPF:21 to:[0:0]]
   *     [0] [@2]: dpo-receive
   * @cliexend
   * @endparblock
  ?*/
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (set_ip6_flow_hash_command, static) =
  {
    .path = "set ip6 flow-hash",
    .short_help =
    "set ip6 flow-hash table <table-id> [src] [dst] [sport] [dport] [proto] [reverse]",
    .function = set_ip6_flow_hash_command_fn,
  };
  /* *INDENT-ON* */
  
  static clib_error_t *
  show_ip6_local_command_fn (vlib_main_t * vm,
  			   unformat_input_t * input, vlib_cli_command_t * cmd)
  {
    ip6_main_t *im = &ip6_main;
    ip_lookup_main_t *lm = &im->lookup_main;
    int i;
  
    vlib_cli_output (vm, "Protocols handled by ip6_local");
    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)
  	{
  
  	  u32 node_index = vlib_get_node (vm,
  					  ip6_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;
  }
  
  
  
  /*?
   * Display the set of protocols handled by the local IPv6 stack.
   *
   * @cliexpar
   * Example of how to display local protocol table:
   * @cliexstart{show ip6 local}
   * Protocols handled by ip6_local
   * 17
   * 43
   * 58
   * 115
   * @cliexend
  ?*/
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (show_ip6_local, static) =
  {
    .path = "show ip6 local",
    .function = show_ip6_local_command_fn,
    .short_help = "show ip6 local",
  };
  /* *INDENT-ON* */
  
  #ifndef CLIB_MARCH_VARIANT
  int
  vnet_set_ip6_classify_intfc (vlib_main_t * vm, u32 sw_if_index,
  			     u32 table_index)
  {
    vnet_main_t *vnm = vnet_get_main ();
    vnet_interface_main_t *im = &vnm->interface_main;
    ip6_main_t *ipm = &ip6_main;
    ip_lookup_main_t *lm = &ipm->lookup_main;
    vnet_classify_main_t *cm = &vnet_classify_main;
    ip6_address_t *if_addr;
  
    if (pool_is_free_index (im->sw_interfaces, sw_if_index))
      return VNET_API_ERROR_NO_MATCHING_INTERFACE;
  
    if (table_index != ~0 && pool_is_free_index (cm->tables, table_index))
      return VNET_API_ERROR_NO_SUCH_ENTRY;
  
    vec_validate (lm->classify_table_index_by_sw_if_index, sw_if_index);
    lm->classify_table_index_by_sw_if_index[sw_if_index] = table_index;
  
    if_addr = ip6_interface_first_address (ipm, sw_if_index);
  
    if (NULL != if_addr)
      {
        fib_prefix_t pfx = {
  	.fp_len = 128,
  	.fp_proto = FIB_PROTOCOL_IP6,
  	.fp_addr.ip6 = *if_addr,
        };
        u32 fib_index;
  
        fib_index = fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
  						       sw_if_index);
  
  
        if (table_index != (u32) ~ 0)
  	{
  	  dpo_id_t dpo = DPO_INVALID;
  
  	  dpo_set (&dpo,
  		   DPO_CLASSIFY,
  		   DPO_PROTO_IP6,
  		   classify_dpo_create (DPO_PROTO_IP6, table_index));
  
  	  fib_table_entry_special_dpo_add (fib_index,
  					   &pfx,
  					   FIB_SOURCE_CLASSIFY,
  					   FIB_ENTRY_FLAG_NONE, &dpo);
  	  dpo_reset (&dpo);
  	}
        else
  	{
  	  fib_table_entry_special_remove (fib_index,
  					  &pfx, FIB_SOURCE_CLASSIFY);
  	}
      }
  
    return 0;
  }
  #endif
  
  static clib_error_t *
  set_ip6_classify_command_fn (vlib_main_t * vm,
  			     unformat_input_t * input,
  			     vlib_cli_command_t * cmd)
  {
    u32 table_index = ~0;
    int table_index_set = 0;
    u32 sw_if_index = ~0;
    int rv;
  
    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
      {
        if (unformat (input, "table-index %d", &table_index))
  	table_index_set = 1;
        else if (unformat (input, "intfc %U", unformat_vnet_sw_interface,
  			 vnet_get_main (), &sw_if_index))
  	;
        else
  	break;
      }
  
    if (table_index_set == 0)
      return clib_error_return (0, "classify table-index must be specified");
  
    if (sw_if_index == ~0)
      return clib_error_return (0, "interface / subif must be specified");
  
    rv = vnet_set_ip6_classify_intfc (vm, sw_if_index, table_index);
  
    switch (rv)
      {
      case 0:
        break;
  
      case VNET_API_ERROR_NO_MATCHING_INTERFACE:
        return clib_error_return (0, "No such interface");
  
      case VNET_API_ERROR_NO_SUCH_ENTRY:
        return clib_error_return (0, "No such classifier table");
      }
    return 0;
  }
  
  /*?
   * Assign a classification table to an interface. The classification
   * table is created using the '<em>classify table</em>' and '<em>classify session</em>'
   * commands. Once the table is create, use this command to filter packets
   * on an interface.
   *
   * @cliexpar
   * Example of how to assign a classification table to an interface:
   * @cliexcmd{set ip6 classify intfc GigabitEthernet2/0/0 table-index 1}
  ?*/
  /* *INDENT-OFF* */
  VLIB_CLI_COMMAND (set_ip6_classify_command, static) =
  {
    .path = "set ip6 classify",
    .short_help =
    "set ip6 classify intfc <interface> table-index <classify-idx>",
    .function = set_ip6_classify_command_fn,
  };
  /* *INDENT-ON* */
  
  /*
   * fd.io coding-style-patch-verification: ON
   *
   * Local Variables:
   * eval: (c-set-style "gnu")
   * End:
   */
  