interface.c

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/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * interface.c: VNET interfaces/sub-interfaces
 *
 * 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/plugin/plugin.h>

#define VNET_INTERFACE_SET_FLAGS_HELPER_IS_CREATE (1 << 0)
#define VNET_INTERFACE_SET_FLAGS_HELPER_WANT_REDISTRIBUTE (1 << 1)

static clib_error_t *
vnet_hw_interface_set_flags_helper (vnet_main_t * vnm, u32 hw_if_index, u32 flags,
                                    u32 helper_flags);

static clib_error_t *
vnet_sw_interface_set_flags_helper (vnet_main_t * vnm, u32 sw_if_index, u32 flags,
                                    u32 helper_flags);

static clib_error_t *
vnet_hw_interface_set_class_helper (vnet_main_t * vnm, u32 hw_if_index, u32 hw_class_index, u32 redistribute);

typedef struct {
  /* Either sw or hw interface index. */
  u32 sw_hw_if_index;

  /* Flags. */
  u32 flags;
} vnet_sw_hw_interface_state_t;

static void serialize_vec_vnet_sw_hw_interface_state (serialize_main_t * m, va_list * va)
{
    vnet_sw_hw_interface_state_t * s = va_arg (*va, vnet_sw_hw_interface_state_t *);
    u32 n = va_arg (*va, u32);
    u32 i;
    for (i = 0; i < n; i++) {
        serialize_integer (m, s[i].sw_hw_if_index, sizeof (s[i].sw_hw_if_index));
        serialize_integer (m, s[i].flags, sizeof (s[i].flags));
    }
}

static void unserialize_vec_vnet_sw_hw_interface_state (serialize_main_t * m, va_list * va)
{
    vnet_sw_hw_interface_state_t * s = va_arg (*va, vnet_sw_hw_interface_state_t *);
    u32 n = va_arg (*va, u32);
    u32 i;
    for (i = 0; i < n; i++) {
        unserialize_integer (m, &s[i].sw_hw_if_index, sizeof (s[i].sw_hw_if_index));
        unserialize_integer (m, &s[i].flags, sizeof (s[i].flags));
    }
}

static void serialize_vnet_sw_hw_interface_set_flags (serialize_main_t * m, va_list * va)
{
  vnet_sw_hw_interface_state_t * s = va_arg (*va, vnet_sw_hw_interface_state_t *);
  serialize (m, serialize_vec_vnet_sw_hw_interface_state, s, 1);
}

static void unserialize_vnet_sw_interface_set_flags (serialize_main_t * m, va_list * va)
{
  CLIB_UNUSED (mc_main_t * mc) = va_arg (*va, mc_main_t *);
  vnet_sw_hw_interface_state_t s;

  unserialize (m, unserialize_vec_vnet_sw_hw_interface_state, &s, 1);

  vnet_sw_interface_set_flags_helper
    (vnet_get_main(), s.sw_hw_if_index, s.flags,
     /* helper_flags no redistribution */ 0);
}

static void unserialize_vnet_hw_interface_set_flags (serialize_main_t * m, va_list * va)
{
  CLIB_UNUSED (mc_main_t * mc) = va_arg (*va, mc_main_t *);
  vnet_sw_hw_interface_state_t s;

  unserialize (m, unserialize_vec_vnet_sw_hw_interface_state, &s, 1);

  vnet_hw_interface_set_flags_helper
    (vnet_get_main(), s.sw_hw_if_index, s.flags,
     /* helper_flags no redistribution */ 0);
}

MC_SERIALIZE_MSG (vnet_sw_interface_set_flags_msg, static) = {
  .name = "vnet_sw_interface_set_flags",
  .serialize = serialize_vnet_sw_hw_interface_set_flags,
  .unserialize = unserialize_vnet_sw_interface_set_flags,
};

MC_SERIALIZE_MSG (vnet_hw_interface_set_flags_msg, static) = {
  .name = "vnet_hw_interface_set_flags",
  .serialize = serialize_vnet_sw_hw_interface_set_flags,
  .unserialize = unserialize_vnet_hw_interface_set_flags,
};

void serialize_vnet_interface_state (serialize_main_t * m, va_list * va)
{
  vnet_main_t * vnm = va_arg (*va, vnet_main_t *);
  vnet_sw_hw_interface_state_t * sts = 0, * st;
  vnet_sw_interface_t * sif;
  vnet_hw_interface_t * hif;
  vnet_interface_main_t * im = &vnm->interface_main;

  /* Serialize hardware interface classes since they may have changed.
     Must do this before sending up/down flags. */
  pool_foreach (hif, im->hw_interfaces, ({
    vnet_hw_interface_class_t * hw_class = vnet_get_hw_interface_class (vnm, hif->hw_class_index);
    serialize_cstring (m, hw_class->name);
  }));

  /* Send sw/hw interface state when non-zero. */
  pool_foreach (sif, im->sw_interfaces, ({
    if (sif->flags != 0)
      {
        vec_add2 (sts, st, 1);
        st->sw_hw_if_index = sif->sw_if_index;
        st->flags = sif->flags;
      }
  }));

  vec_serialize (m, sts, serialize_vec_vnet_sw_hw_interface_state);

  if (sts)
    _vec_len (sts) = 0;

  pool_foreach (hif, im->hw_interfaces, ({
    if (hif->flags != 0)
      {
        vec_add2 (sts, st, 1);
        st->sw_hw_if_index = hif->hw_if_index;
        st->flags = hif->flags;
      }
  }));

  vec_serialize (m, sts, serialize_vec_vnet_sw_hw_interface_state);

  vec_free (sts);
}

void unserialize_vnet_interface_state (serialize_main_t * m, va_list * va)
{
  vnet_main_t * vnm = va_arg (*va, vnet_main_t *);
  vnet_sw_hw_interface_state_t * sts = 0, * st;

  /* First set interface hardware class. */
  {
    vnet_interface_main_t * im = &vnm->interface_main;
    vnet_hw_interface_t * hif;
    char * class_name;
    uword * p;
    clib_error_t * error;

    pool_foreach (hif, im->hw_interfaces, ({
      unserialize_cstring (m, &class_name);
      p = hash_get_mem (im->hw_interface_class_by_name, class_name);
      ASSERT (p != 0);
      error = vnet_hw_interface_set_class_helper (vnm, hif->hw_if_index, p[0], /* redistribute */ 0);
      if (error)
        clib_error_report (error);
      vec_free (class_name);
    }));
  }

  vec_unserialize (m, &sts, unserialize_vec_vnet_sw_hw_interface_state);
  vec_foreach (st, sts)
    vnet_sw_interface_set_flags_helper (vnm, st->sw_hw_if_index, st->flags,
                                        /* no distribute */ 0);
  vec_free (sts);

  vec_unserialize (m, &sts, unserialize_vec_vnet_sw_hw_interface_state);
  vec_foreach (st, sts)
    vnet_hw_interface_set_flags_helper (vnm, st->sw_hw_if_index, st->flags,
                                        /* no distribute */ 0);
  vec_free (sts);
}

static clib_error_t *
call_elf_section_interface_callbacks (vnet_main_t * vnm, u32 if_index, 
                                      u32 flags, 
                                      _vnet_interface_function_list_elt_t *elt)
{
  clib_error_t * error = 0;

  while (elt)
    {
      error = elt->fp(vnm, if_index, flags);
      if (error)
        return error;
      elt = elt->next_interface_function;
    }
  return error;
}

static clib_error_t *
call_hw_interface_add_del_callbacks (vnet_main_t * vnm, u32 hw_if_index, u32 is_create)
{
  vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, hw_if_index);
  vnet_hw_interface_class_t * hw_class = vnet_get_hw_interface_class (vnm, hi->hw_class_index);
  vnet_device_class_t * dev_class = vnet_get_device_class (vnm, hi->dev_class_index);
  clib_error_t * error = 0;

  if (hw_class->interface_add_del_function
      && (error = hw_class->interface_add_del_function (vnm, hw_if_index, is_create)))
    return error;

  if (dev_class->interface_add_del_function
      && (error = dev_class->interface_add_del_function (vnm, hw_if_index, is_create)))
    return error;

  error = call_elf_section_interface_callbacks 
    (vnm, hw_if_index, is_create, vnm->hw_interface_add_del_functions);

  return error;
}

static clib_error_t *
call_sw_interface_add_del_callbacks (vnet_main_t * vnm, u32 sw_if_index, u32 is_create)
{
  return call_elf_section_interface_callbacks 
    (vnm, sw_if_index, is_create, vnm->sw_interface_add_del_functions);
}

#define VNET_INTERFACE_SET_FLAGS_HELPER_IS_CREATE (1 << 0)
#define VNET_INTERFACE_SET_FLAGS_HELPER_WANT_REDISTRIBUTE (1 << 1)

static clib_error_t *
vnet_hw_interface_set_flags_helper (vnet_main_t * vnm, u32 hw_if_index, u32 flags,
                                    u32 helper_flags)
{
  vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, hw_if_index);
  vnet_hw_interface_class_t * hw_class = vnet_get_hw_interface_class (vnm, hi->hw_class_index);
  vnet_device_class_t * dev_class = vnet_get_device_class (vnm, hi->dev_class_index);
  vlib_main_t * vm = vnm->vlib_main;
  u32 mask;
  clib_error_t * error = 0;
  u32 is_create = (helper_flags & VNET_INTERFACE_SET_FLAGS_HELPER_IS_CREATE) != 0;

  mask = (VNET_HW_INTERFACE_FLAG_LINK_UP | VNET_HW_INTERFACE_FLAG_DUPLEX_MASK |
          VNET_HW_INTERFACE_FLAG_SPEED_MASK);
  flags &= mask;

  /* Call hardware interface add/del callbacks. */
  if (is_create)
    call_hw_interface_add_del_callbacks (vnm, hw_if_index, is_create);

  /* Already in the desired state? */
  if (! is_create && (hi->flags & mask) == flags)
    goto done;

  /* Some interface classes do not redistribute (e.g. are local). */
  if (! dev_class->redistribute)
    helper_flags &= ~ VNET_INTERFACE_SET_FLAGS_HELPER_WANT_REDISTRIBUTE;

  if (vm->mc_main
      && (helper_flags & VNET_INTERFACE_SET_FLAGS_HELPER_WANT_REDISTRIBUTE))
    {
      vnet_sw_hw_interface_state_t s;
      s.sw_hw_if_index = hw_if_index;
      s.flags = flags;
      mc_serialize (vm->mc_main, &vnet_hw_interface_set_flags_msg, &s);
    }

  if ((hi->flags & VNET_HW_INTERFACE_FLAG_LINK_UP) !=
      (flags & VNET_HW_INTERFACE_FLAG_LINK_UP))
    {
      /* Do hardware class (e.g. ethernet). */
      if (hw_class->link_up_down_function
          && (error = hw_class->link_up_down_function (vnm, hw_if_index,
                                                       flags)))
        goto done;

      error = call_elf_section_interface_callbacks 
        (vnm, hw_if_index, is_create, vnm->hw_interface_link_up_down_functions);
      
      if (error)
        goto done;
    }

  hi->flags &= ~mask;
  hi->flags |= flags;

 done:
  return error;
}

static clib_error_t *
vnet_sw_interface_set_flags_helper (vnet_main_t * vnm, u32 sw_if_index, u32 flags,
                                    u32 helper_flags)
{
  vnet_sw_interface_t * si = vnet_get_sw_interface (vnm, sw_if_index);
  vlib_main_t * vm = vnm->vlib_main;
  u32 mask;
  clib_error_t * error = 0;
  u32 is_create = (helper_flags & VNET_INTERFACE_SET_FLAGS_HELPER_IS_CREATE) != 0;
  u32 old_flags;

  mask = VNET_SW_INTERFACE_FLAG_ADMIN_UP | VNET_SW_INTERFACE_FLAG_PUNT;
  flags &= mask;

  if (is_create)
    {
      error = call_sw_interface_add_del_callbacks (vnm, sw_if_index, is_create);
      if (error)
        goto done;

      if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
        {
          /* Notify everyone when the interface is created as admin up */
          error = call_elf_section_interface_callbacks (vnm, sw_if_index,
                      flags, vnm->sw_interface_admin_up_down_functions);
          if (error)
            goto done;
        }
    }
  else
    {
      vnet_sw_interface_t * si_sup = si;

      /* Check that super interface is in correct state. */
      if (si->type == VNET_SW_INTERFACE_TYPE_SUB)
        {
          si_sup = vnet_get_sw_interface (vnm, si->sup_sw_if_index);

          if (flags != (si_sup->flags & mask))
            {
              error = clib_error_return (0, "super-interface %U must be %U",
                                         format_vnet_sw_interface_name, vnm, si_sup,
                                         format_vnet_sw_interface_flags, flags);
              goto done;
            }
        }

      /* Donot change state for slave link of bonded interfaces */
      if (si->flags & VNET_SW_INTERFACE_FLAG_BOND_SLAVE)
        {
          error = clib_error_return 
              (0, "not allowed as %U belong to a BondEthernet interface",
               format_vnet_sw_interface_name, vnm, si);
          goto done;
        }

      /* Already in the desired state? */
      if ((si->flags & mask) == flags)
        goto done;

      /* Sub-interfaces of hardware interfaces that do no redistribute,
         do not redistribute themselves. */
      if (si_sup->type == VNET_SW_INTERFACE_TYPE_HARDWARE)
        {
          vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, si_sup->hw_if_index);
          vnet_device_class_t * dev_class = vnet_get_device_class (vnm, hi->dev_class_index);
          if (! dev_class->redistribute)
            helper_flags &= ~ VNET_INTERFACE_SET_FLAGS_HELPER_WANT_REDISTRIBUTE;
        }

      if (vm->mc_main
          && (helper_flags & VNET_INTERFACE_SET_FLAGS_HELPER_WANT_REDISTRIBUTE))
        {
          vnet_sw_hw_interface_state_t s;
          s.sw_hw_if_index = sw_if_index;
          s.flags = flags;
          mc_serialize (vm->mc_main, &vnet_sw_interface_set_flags_msg, &s);
        }

      error = call_elf_section_interface_callbacks 
        (vnm, sw_if_index, flags, vnm->sw_interface_admin_up_down_functions);

      if (error)
        goto done;

      if (si->type == VNET_SW_INTERFACE_TYPE_HARDWARE)
        {
          vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, si->hw_if_index);
          vnet_hw_interface_class_t * hw_class = vnet_get_hw_interface_class (vnm, hi->hw_class_index);
          vnet_device_class_t * dev_class = vnet_get_device_class (vnm, hi->dev_class_index);

          /* save the si admin up flag */
          old_flags = si->flags;

          /* update si admin up flag in advance if we are going admin down */
          if (!(flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP))
              si->flags &=  ~VNET_SW_INTERFACE_FLAG_ADMIN_UP;

          if (dev_class->admin_up_down_function
              && (error = dev_class->admin_up_down_function(vnm,
                                                            si->hw_if_index,
                                                            flags)))
            {
              /* restore si admin up flag to it's original state on errors */
              si->flags =  old_flags;
              goto done;
            }

          if (hw_class->admin_up_down_function
              && (error = hw_class->admin_up_down_function(vnm,
                                                           si->hw_if_index,
                                                           flags)))
            {
              /* restore si admin up flag to it's original state on errors */
              si->flags =  old_flags;
              goto done;
            }

          /* Admin down implies link down. */
          if (! (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
              && (hi->flags & VNET_HW_INTERFACE_FLAG_LINK_UP))
            vnet_hw_interface_set_flags_helper (vnm, si->hw_if_index,
                                                hi->flags &~ VNET_HW_INTERFACE_FLAG_LINK_UP,
                                                helper_flags);
        }
    }

  si->flags &= ~mask;
  si->flags |= flags;

 done:
  return error;
}

clib_error_t *
vnet_hw_interface_set_flags (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
{
  return vnet_hw_interface_set_flags_helper
    (vnm, hw_if_index, flags,
     VNET_INTERFACE_SET_FLAGS_HELPER_WANT_REDISTRIBUTE);
}

clib_error_t *
vnet_sw_interface_set_flags (vnet_main_t * vnm, u32 sw_if_index, u32 flags)
{
  return vnet_sw_interface_set_flags_helper
    (vnm, sw_if_index, flags,
     VNET_INTERFACE_SET_FLAGS_HELPER_WANT_REDISTRIBUTE);
}

static u32
vnet_create_sw_interface_no_callbacks (vnet_main_t * vnm, vnet_sw_interface_t * template)
{
  vnet_interface_main_t * im = &vnm->interface_main;
  vnet_sw_interface_t * sw;
  u32 sw_if_index;

  pool_get (im->sw_interfaces, sw);
  sw_if_index = sw - im->sw_interfaces;

  sw[0] = template[0];

  sw->flags = 0;
  sw->sw_if_index = sw_if_index;
  if (sw->type == VNET_SW_INTERFACE_TYPE_HARDWARE)
    sw->sup_sw_if_index = sw->sw_if_index;

  /* Allocate counters for this interface. */
  {
    u32 i;

    vnet_interface_counter_lock(im);

    for (i = 0; i < vec_len (im->sw_if_counters); i++)
      {
        vlib_validate_simple_counter (&im->sw_if_counters[i], sw_if_index);
        vlib_zero_simple_counter (&im->sw_if_counters[i], sw_if_index);
      }

    for (i = 0; i < vec_len (im->combined_sw_if_counters); i++)
      {
        vlib_validate_combined_counter (&im->combined_sw_if_counters[i], 
                                        sw_if_index);
        vlib_zero_combined_counter (&im->combined_sw_if_counters[i], 
                                    sw_if_index);
      }

    vnet_interface_counter_unlock(im);
  }

  return sw_if_index;
}

clib_error_t *
vnet_create_sw_interface (vnet_main_t * vnm, vnet_sw_interface_t * template, u32 * sw_if_index)
{
  clib_error_t * error;
  vnet_hw_interface_t * hi;
  vnet_device_class_t * dev_class;

  hi = vnet_get_sup_hw_interface (vnm, template->sup_sw_if_index);
  dev_class = vnet_get_device_class (vnm, hi->dev_class_index);

  if (template->type == VNET_SW_INTERFACE_TYPE_SUB &&
      dev_class->subif_add_del_function) {
        error = dev_class->subif_add_del_function (vnm, hi->hw_if_index,
                                                   (struct vnet_sw_interface_t *) template, 1);
        if (error)
          return error;
  }

  *sw_if_index = vnet_create_sw_interface_no_callbacks (vnm, template);
  error = vnet_sw_interface_set_flags_helper
    (vnm, *sw_if_index, template->flags,
     VNET_INTERFACE_SET_FLAGS_HELPER_IS_CREATE);

  if (error) {
    // undo the work done by vnet_create_sw_interface_no_callbacks()
    vnet_interface_main_t * im = &vnm->interface_main;
    vnet_sw_interface_t * sw = pool_elt_at_index (im->sw_interfaces, *sw_if_index);
    pool_put (im->sw_interfaces, sw);
  }

  return error;
}

void vnet_delete_sw_interface (vnet_main_t * vnm, u32 sw_if_index)
{
  vnet_interface_main_t * im = &vnm->interface_main;
  vnet_sw_interface_t * sw = pool_elt_at_index (im->sw_interfaces, sw_if_index);

  /* Bring down interface in case it is up. */
  if (sw->flags != 0)
    vnet_sw_interface_set_flags (vnm, sw_if_index, /* flags */ 0);

  call_sw_interface_add_del_callbacks (vnm, sw_if_index, /* is_create */ 0);

  pool_put (im->sw_interfaces, sw);
}

static void setup_tx_node (vlib_main_t * vm,
                           u32 node_index,
                           vnet_device_class_t * dev_class)
{
  vlib_node_t * n = vlib_get_node (vm, node_index);

  n->function = dev_class->tx_function;
  n->format_trace = dev_class->format_tx_trace;
  vlib_register_errors (vm, node_index, 
                        dev_class->tx_function_n_errors,
                        dev_class->tx_function_error_strings);
}

static void setup_output_node (vlib_main_t * vm,
                               u32 node_index,
                               vnet_hw_interface_class_t * hw_class)
{
  vlib_node_t * n = vlib_get_node (vm, node_index);
  n->format_buffer = hw_class->format_header;
  n->unformat_buffer = hw_class->unformat_header;
}

/* Register an interface instance. */
u32
vnet_register_interface (vnet_main_t * vnm,
                         u32 dev_class_index,
                         u32 dev_instance,
                         u32 hw_class_index,
                         u32 hw_instance)
{
  vnet_interface_main_t * im = &vnm->interface_main;
  vnet_hw_interface_t * hw;
  vnet_device_class_t * dev_class = vnet_get_device_class (vnm, dev_class_index);
  vnet_hw_interface_class_t * hw_class = vnet_get_hw_interface_class (vnm, hw_class_index);
  vlib_main_t * vm = vnm->vlib_main;
  u32 hw_index;
  char * tx_node_name, * output_node_name;

  pool_get (im->hw_interfaces, hw);

  hw_index = hw - im->hw_interfaces;
  hw->hw_if_index = hw_index;

  if (dev_class->format_device_name)
    hw->name = format (0, "%U",
                       dev_class->format_device_name, dev_instance);
  else if (hw_class->format_interface_name)
    hw->name = format (0, "%U", hw_class->format_interface_name,
                       dev_instance);
  else
    hw->name = format (0, "%s%x", hw_class->name, dev_instance);

  if (! im->hw_interface_by_name)
    im->hw_interface_by_name = hash_create_vec (/* size */ 0,
                                                sizeof (hw->name[0]),
                                                sizeof (uword));

  hash_set_mem (im->hw_interface_by_name, hw->name, hw_index);

  /* Make hardware interface point to software interface. */
  {
    vnet_sw_interface_t sw;

    memset (&sw, 0, sizeof (sw));
    sw.type = VNET_SW_INTERFACE_TYPE_HARDWARE;
    sw.hw_if_index = hw_index;
    hw->sw_if_index = vnet_create_sw_interface_no_callbacks (vnm, &sw);
  }

  hw->dev_class_index = dev_class_index;
  hw->dev_instance = dev_instance;
  hw->hw_class_index = hw_class_index;
  hw->hw_instance = hw_instance;

  hw->max_rate_bits_per_sec = 0;
  hw->min_packet_bytes = 0;
  hw->per_packet_overhead_bytes = 0;
  hw->max_l3_packet_bytes[VLIB_RX] = ~0;
  hw->max_l3_packet_bytes[VLIB_TX] = ~0;

  tx_node_name = (char *) format (0, "%v-tx", hw->name);
  output_node_name = (char *) format (0, "%v-output", hw->name);

  /* If we have previously deleted interface nodes, re-use them. */
  if (vec_len (im->deleted_hw_interface_nodes) > 0)
    {
      vnet_hw_interface_nodes_t * hn;
      vnet_interface_output_runtime_t * rt;

      hn = vec_end (im->deleted_hw_interface_nodes) - 1;

      hw->tx_node_index = hn->tx_node_index;
      hw->output_node_index = hn->output_node_index;

      vlib_node_rename (vm, hw->tx_node_index, "%v", tx_node_name);
      vlib_node_rename (vm, hw->output_node_index, "%v", output_node_name);

      rt = vlib_node_get_runtime_data (vm, hw->output_node_index);
      ASSERT (rt->is_deleted == 1);
      rt->is_deleted = 0;

      _vec_len (im->deleted_hw_interface_nodes) -= 1;
    }
  else
    {
      vlib_node_registration_t r;
      vnet_interface_output_runtime_t rt = {
        .hw_if_index = hw_index,
        .sw_if_index = hw->sw_if_index,
        .dev_instance = hw->dev_instance,
        .is_deleted = 0,
      };

      memset (&r, 0, sizeof (r));
      r.type = VLIB_NODE_TYPE_INTERNAL;
      r.runtime_data = &rt;
      r.runtime_data_bytes = sizeof (rt);
      r.scalar_size = 0;
      r.vector_size = sizeof (u32);

      r.flags = VLIB_NODE_FLAG_IS_OUTPUT;
      r.name = tx_node_name;
      r.function = dev_class->tx_function;

      hw->tx_node_index = vlib_register_node (vm, &r);

      vlib_node_add_named_next_with_slot (vm, hw->tx_node_index,
                                          "error-drop",
                                          VNET_INTERFACE_TX_NEXT_DROP);

      r.flags = 0;
      r.name = output_node_name;
      r.function =  dev_class->no_flatten_output_chains ?
          vnet_interface_output_node_no_flatten : 
          vnet_interface_output_node;
      r.format_trace = format_vnet_interface_output_trace;

      {
        static char * e[] = {
          "interface is down",
          "interface is deleted",
        };

        r.n_errors = ARRAY_LEN (e);
        r.error_strings = e;
      }

      hw->output_node_index = vlib_register_node (vm, &r);

#define _(sym,str) vlib_node_add_named_next_with_slot (vm, \
                     hw->output_node_index, str,           \
                     VNET_INTERFACE_OUTPUT_NEXT_##sym);
      foreach_intf_output_feat
#undef _

      vlib_node_add_named_next_with_slot (vm, hw->output_node_index,
                                          "error-drop",
                                          VNET_INTERFACE_OUTPUT_NEXT_DROP);
      vlib_node_add_next_with_slot (vm, hw->output_node_index,
                                    hw->tx_node_index,
                                    VNET_INTERFACE_OUTPUT_NEXT_TX);
    }

  setup_output_node (vm, hw->output_node_index, hw_class);
  setup_tx_node (vm, hw->tx_node_index, dev_class);

  /* Call all up/down callbacks with zero flags when interface is created. */
  vnet_sw_interface_set_flags_helper
    (vnm, hw->sw_if_index, /* flags */ 0,
     VNET_INTERFACE_SET_FLAGS_HELPER_IS_CREATE);
  vnet_hw_interface_set_flags_helper
    (vnm, hw_index, /* flags */ 0,
     VNET_INTERFACE_SET_FLAGS_HELPER_IS_CREATE);

  return hw_index;
}

void vnet_delete_hw_interface (vnet_main_t * vnm, u32 hw_if_index)
{
  vnet_interface_main_t * im = &vnm->interface_main;
  vnet_hw_interface_t * hw = vnet_get_hw_interface (vnm, hw_if_index);
  vlib_main_t * vm = vnm->vlib_main;

  /* If it is up, mark it down. */
  if (hw->flags != 0)
    vnet_hw_interface_set_flags (vnm, hw_if_index, /* flags */ 0);

  /* Call delete callbacks. */
  call_hw_interface_add_del_callbacks (vnm, hw_if_index, /* is_create */ 0);

  /* Delete software interface corresponding to hardware interface. */
  vnet_delete_sw_interface (vnm, hw->sw_if_index);

  /* Delete any sub-interfaces. */
  {
    u32 id, sw_if_index;
    hash_foreach (id, sw_if_index, hw->sub_interface_sw_if_index_by_id, ({
      vnet_delete_sw_interface (vnm, sw_if_index);
    }));
  }

  {
    vnet_hw_interface_nodes_t * dn;
    vnet_interface_output_runtime_t * rt = vlib_node_get_runtime_data (vm, hw->output_node_index);

    /* Mark node runtime as deleted so output node (if called) will drop packets. */
    rt->is_deleted = 1;

    vlib_node_rename (vm, hw->output_node_index, "interface-%d-output-deleted", hw_if_index);
    vlib_node_rename (vm, hw->tx_node_index, "interface-%d-tx-deleted", hw_if_index);
    vec_add2 (im->deleted_hw_interface_nodes, dn, 1);
    dn->tx_node_index = hw->tx_node_index;
    dn->output_node_index = hw->output_node_index;
  }

  hash_unset_mem (im->hw_interface_by_name, hw->name);
  vec_free (hw->name);

  pool_put (im->hw_interfaces, hw);
}

static void serialize_vnet_hw_interface_set_class (serialize_main_t * m, va_list * va)
{
  u32 hw_if_index = va_arg (*va, u32);
  char * hw_class_name = va_arg (*va, char *);
  serialize_integer (m, hw_if_index, sizeof (hw_if_index));
  serialize_cstring (m, hw_class_name);
}

static void unserialize_vnet_hw_interface_set_class (serialize_main_t * m, va_list * va)
{
  CLIB_UNUSED (mc_main_t * mc) = va_arg (*va, mc_main_t *);
  vnet_main_t * vnm = vnet_get_main();
  u32 hw_if_index;
  char * hw_class_name;
  uword * p;
  clib_error_t * error;

  unserialize_integer (m, &hw_if_index, sizeof (hw_if_index));
  unserialize_cstring (m, &hw_class_name);
  p = hash_get (vnm->interface_main.hw_interface_class_by_name, hw_class_name);
  ASSERT (p != 0);
  error = vnet_hw_interface_set_class_helper (vnm, hw_if_index, p[0], /* redistribute */ 0);
  if (error)
    clib_error_report (error);
}

MC_SERIALIZE_MSG (vnet_hw_interface_set_class_msg, static) = {
  .name = "vnet_hw_interface_set_class",
  .serialize = serialize_vnet_hw_interface_set_class,
  .unserialize = unserialize_vnet_hw_interface_set_class,
};

void vnet_hw_interface_init_for_class (vnet_main_t * vnm, u32 hw_if_index, u32 hw_class_index, u32 hw_instance)
{
  vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, hw_if_index);
  vnet_hw_interface_class_t * hc = vnet_get_hw_interface_class (vnm, hw_class_index);

  hi->hw_class_index = hw_class_index;
  hi->hw_instance = hw_instance;
  setup_output_node (vnm->vlib_main, hi->output_node_index, hc);
}

static clib_error_t *
vnet_hw_interface_set_class_helper (vnet_main_t * vnm, u32 hw_if_index, u32 hw_class_index, u32 redistribute)
{
  vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, hw_if_index);
  vnet_sw_interface_t * si = vnet_get_sw_interface (vnm, hi->sw_if_index);
  vnet_hw_interface_class_t * old_class = vnet_get_hw_interface_class (vnm, hi->hw_class_index);
  vnet_hw_interface_class_t * new_class = vnet_get_hw_interface_class (vnm, hw_class_index);
  vnet_device_class_t * dev_class = vnet_get_device_class (vnm, hi->dev_class_index);
  clib_error_t * error = 0;

  /* New class equals old class?  Nothing to do. */
  if (hi->hw_class_index == hw_class_index)
    return 0;

  /* No need (and incorrect since admin up flag may be set) to do error checking when
     receiving unserialize message. */
  if (redistribute)
    {
      if (si->flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
        return clib_error_return (0, "%v must be admin down to change class from %s to %s",
                                  hi->name, old_class->name, new_class->name);

      /* Make sure interface supports given class. */
      if ((new_class->is_valid_class_for_interface
           && ! new_class->is_valid_class_for_interface (vnm, hw_if_index, hw_class_index))
          || (dev_class ->is_valid_class_for_interface
              && ! dev_class->is_valid_class_for_interface (vnm, hw_if_index, hw_class_index)))
        return clib_error_return (0, "%v class cannot be changed from %s to %s",
                                  hi->name, old_class->name, new_class->name);

      if (vnm->vlib_main->mc_main)
        {
          mc_serialize (vnm->vlib_main->mc_main, &vnet_hw_interface_set_class_msg, hw_if_index, new_class->name);
          return 0;
        }
    }

  if (old_class->hw_class_change)
    old_class->hw_class_change (vnm, hw_if_index, old_class->index, new_class->index);

  vnet_hw_interface_init_for_class (vnm, hw_if_index, new_class->index, /* instance */ ~0);

  if (new_class->hw_class_change)
    new_class->hw_class_change (vnm, hw_if_index, old_class->index, new_class->index);

  if (dev_class->hw_class_change)
    dev_class->hw_class_change (vnm, hw_if_index, new_class->index);

  return error;
}

clib_error_t *
vnet_hw_interface_set_class (vnet_main_t * vnm, u32 hw_if_index, u32 hw_class_index)
{ return vnet_hw_interface_set_class_helper (vnm, hw_if_index, hw_class_index, /* redistribute */ 1); }

static int
vnet_hw_interface_rx_redirect_to_node_helper (vnet_main_t * vnm, 
                                              u32 hw_if_index, 
                                              u32 node_index, 
                                              u32 redistribute)
{
  vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, hw_if_index);
  vnet_device_class_t * dev_class = vnet_get_device_class 
    (vnm, hi->dev_class_index);

  if (redistribute)
    {
      /* $$$$ fixme someday maybe */
      ASSERT(vnm->vlib_main->mc_main == 0);
    }
  if (dev_class->rx_redirect_to_node)
    {
      dev_class->rx_redirect_to_node (vnm, hw_if_index, node_index);
      return 0;
    }

  return VNET_API_ERROR_UNIMPLEMENTED;
}

int vnet_hw_interface_rx_redirect_to_node (vnet_main_t * vnm, u32 hw_if_index,
                                       u32 node_index)
{ return vnet_hw_interface_rx_redirect_to_node_helper (vnm, hw_if_index,
                                                       node_index,
                                                       1 /* redistribute */); }

word
vnet_sw_interface_compare (vnet_main_t * vnm,
                           uword sw_if_index0, uword sw_if_index1)
{
  vnet_sw_interface_t * sup0 = vnet_get_sup_sw_interface (vnm, sw_if_index0);
  vnet_sw_interface_t * sup1 = vnet_get_sup_sw_interface (vnm, sw_if_index1);
  vnet_hw_interface_t * h0 = vnet_get_hw_interface (vnm, sup0->hw_if_index);
  vnet_hw_interface_t * h1 = vnet_get_hw_interface (vnm, sup1->hw_if_index);

  if (h0 != h1)
    return vec_cmp (h0->name, h1->name);
  return (word) h0->hw_instance - (word) h1->hw_instance;
}

word
vnet_hw_interface_compare (vnet_main_t * vnm,
                           uword hw_if_index0, uword hw_if_index1)
{
  vnet_hw_interface_t * h0 = vnet_get_hw_interface (vnm, hw_if_index0);
  vnet_hw_interface_t * h1 = vnet_get_hw_interface (vnm, hw_if_index1);

  if (h0 != h1)
    return vec_cmp (h0->name, h1->name);
  return (word) h0->hw_instance - (word) h1->hw_instance;
}

clib_error_t *
vnet_interface_init (vlib_main_t * vm)
{
  vnet_main_t * vnm = vnet_get_main();
  vnet_interface_main_t * im = &vnm->interface_main;
  vlib_buffer_t * b = 0;
  vnet_buffer_opaque_t * o = 0;

  /*
   * Keep people from shooting themselves in the foot.
   */
  if (sizeof(b->opaque) != sizeof (vnet_buffer_opaque_t))
    {
#define _(a) if (sizeof(o->a) > sizeof (o->unused))                     \
      clib_warning                                                      \
        ("FATAL: size of opaque union subtype %s is %d (max %d)",       \
         #a, sizeof(o->a), sizeof (o->unused));
    foreach_buffer_opaque_union_subtype;
#undef _

     return clib_error_return 
           (0, "FATAL: size of vlib buffer opaque %d, size of vnet opaque %d",
           sizeof(b->opaque), sizeof (vnet_buffer_opaque_t));
    }

  im->sw_if_counter_lock = clib_mem_alloc_aligned (CLIB_CACHE_LINE_BYTES, 
                                                   CLIB_CACHE_LINE_BYTES);
  im->sw_if_counter_lock[0] = 1; /* should be no need */

  vec_validate (im->sw_if_counters,
                VNET_N_SIMPLE_INTERFACE_COUNTER - 1);
  im->sw_if_counters[VNET_INTERFACE_COUNTER_DROP].name = "drops";
  im->sw_if_counters[VNET_INTERFACE_COUNTER_PUNT].name = "punts";
  im->sw_if_counters[VNET_INTERFACE_COUNTER_IP4].name  = "ip4";
  im->sw_if_counters[VNET_INTERFACE_COUNTER_IP6].name  = "ip6";
  im->sw_if_counters[VNET_INTERFACE_COUNTER_RX_NO_BUF].name = "rx-no-buf";
  im->sw_if_counters[VNET_INTERFACE_COUNTER_RX_MISS].name = "rx-miss";
  im->sw_if_counters[VNET_INTERFACE_COUNTER_RX_ERROR].name = "rx-error";
  im->sw_if_counters[VNET_INTERFACE_COUNTER_TX_ERROR].name = "tx-error";

  vec_validate (im->combined_sw_if_counters,
                VNET_N_COMBINED_INTERFACE_COUNTER - 1);
  im->combined_sw_if_counters[VNET_INTERFACE_COUNTER_RX].name = "rx";
  im->combined_sw_if_counters[VNET_INTERFACE_COUNTER_TX].name = "tx";

  im->sw_if_counter_lock[0] = 0;

  im->device_class_by_name = hash_create_string (/* size */ 0,
                                                 sizeof (uword));
  {
    vnet_device_class_t * c;

    c = vnm->device_class_registrations;

    while (c)
      {
        c->index = vec_len (im->device_classes);
        hash_set_mem (im->device_class_by_name, c->name, c->index);
        vec_add1 (im->device_classes, c[0]);
        c = c->next_class_registration;
      }
  }

  im->hw_interface_class_by_name = hash_create_string (/* size */ 0,
                                                       sizeof (uword));

  im->sw_if_index_by_sup_and_sub = hash_create_mem (0, sizeof(u64), 
                                                    sizeof (uword));
  {
    vnet_hw_interface_class_t * c;

    c = vnm->hw_interface_class_registrations;
    
    while (c)
      {
        c->index = vec_len (im->hw_interface_classes);
        hash_set_mem (im->hw_interface_class_by_name, c->name, c->index);
        vec_add1 (im->hw_interface_classes, c[0]);
        c = c->next_class_registration;
      }
  }

  {
    clib_error_t * error;

    if ((error = vlib_call_init_function (vm, vnet_interface_cli_init)))
      return error;

    return error;
  }
}

VLIB_INIT_FUNCTION (vnet_interface_init);

/* Kludge to renumber interface names [only!] */
int vnet_interface_name_renumber (u32 sw_if_index, u32 new_show_dev_instance)
{
  int rv;
  vnet_main_t * vnm = vnet_get_main();
  vnet_interface_main_t * im = &vnm->interface_main;
  vnet_hw_interface_t * hi = vnet_get_sup_hw_interface (vnm, sw_if_index);

  vnet_device_class_t * dev_class = vnet_get_device_class 
    (vnm, hi->dev_class_index);

  if (dev_class->name_renumber == 0 || dev_class->format_device_name == 0)
      return VNET_API_ERROR_UNIMPLEMENTED;

  rv = dev_class->name_renumber (hi, new_show_dev_instance);

  if (rv)
    return rv;

  hash_unset_mem (im->hw_interface_by_name, hi->name);
  vec_free (hi->name);
  /* Use the mapping we set up to call it Ishmael */
  hi->name = format (0, "%U", dev_class->format_device_name, 
                     hi->dev_instance);
  
  hash_set_mem (im->hw_interface_by_name, hi->name, hi->hw_if_index);
  return rv;
}

int vnet_interface_add_del_feature(vnet_main_t * vnm,
                                   vlib_main_t *vm,
                                   u32 sw_if_index,
                                   intf_output_feat_t feature,
                                   int is_add)
{
  vnet_sw_interface_t * sw;

  sw = vnet_get_sw_interface(vnm, sw_if_index);

  if (is_add) {

    sw->output_feature_bitmap |= (1 << feature);
    sw->output_feature_bitmap |= (1<< INTF_OUTPUT_FEAT_DONE);

  } else { /* delete */

    sw->output_feature_bitmap &= ~(1<<feature);
    if (sw->output_feature_bitmap == (1 << INTF_OUTPUT_FEAT_DONE))
      sw->output_feature_bitmap = 0;

  }
  return 0;
}

clib_error_t *
vnet_rename_interface (vnet_main_t * vnm,
                       u32           hw_if_index,
                       char *        new_name)
{
  vnet_interface_main_t * im = &vnm->interface_main;
  vlib_main_t * vm = vnm->vlib_main;
  vnet_hw_interface_t* hw;
  u8* old_name;
  clib_error_t * error = 0;

  hw = vnet_get_hw_interface(vnm, hw_if_index);
  if (!hw)
    {
      return clib_error_return (0,
                                "unable to find hw interface for index %u",
                                 hw_if_index);
    }

  old_name = hw->name;

  // set new hw->name
  hw->name = format (0, "%s", new_name);

  // remove the old name to hw_if_index mapping and install the new one
  hash_unset_mem (im->hw_interface_by_name, old_name);
  hash_set_mem (im->hw_interface_by_name, hw->name, hw_if_index);

  // rename tx/output nodes
  vlib_node_rename (vm, hw->tx_node_index, "%v-tx", hw->name);
  vlib_node_rename (vm, hw->output_node_index, "%v-output", hw->name);

  // free the old name vector
  vec_free (old_name);

  return error;
}