/*
 * mpls.c: mpls
 *
 * Copyright (c) 2012 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.
 */

#include <vnet/vnet.h>
#include <vnet/mpls-gre/mpls.h>

mpls_main_t mpls_main;

u8 * format_mpls_gre_tx_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 *);
  mpls_gre_tx_trace_t * t = va_arg (*args, mpls_gre_tx_trace_t *);
  mpls_main_t * mm = &mpls_main;
    
  if (t->lookup_miss)
    s = format (s, "MPLS: lookup miss");
  else
    {
      s = format (s, "MPLS: tunnel %d labels %U len %d src %U dst %U",
                  t->tunnel_id,
                  format_mpls_encap_index, mm, t->mpls_encap_index, 
                  clib_net_to_host_u16 (t->length),
                  format_ip4_address, &t->src.as_u8,
                  format_ip4_address, &t->dst.as_u8);
    }
  return s;
}

u8 * format_mpls_eth_tx_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 *);
  mpls_eth_tx_trace_t * t = va_arg (*args, mpls_eth_tx_trace_t *);
  mpls_main_t * mm = &mpls_main;
    
  if (t->lookup_miss)
    s = format (s, "MPLS: lookup miss");
  else
    {
      s = format (s, "MPLS: tunnel %d labels %U len %d tx_sw_index %d dst %U",
                  t->tunnel_id,
                  format_mpls_encap_index, mm, t->mpls_encap_index, 
                  clib_net_to_host_u16 (t->length),
                  t->tx_sw_if_index, 
                  format_ethernet_address, t->dst);
    }
  return s;
}

u8 * format_mpls_eth_header_with_length (u8 * s, va_list * args)
{
  ethernet_header_t * h = va_arg (*args, ethernet_header_t *);
  mpls_unicast_header_t * m = (mpls_unicast_header_t *)(h+1);
  u32 max_header_bytes = va_arg (*args, u32);
  uword header_bytes;

  header_bytes = sizeof (h[0]);
  if (max_header_bytes != 0 && header_bytes > max_header_bytes)
    return format (s, "ethernet header truncated");

  s = format 
    (s, "ETHERNET-MPLS label %d", 
     vnet_mpls_uc_get_label (clib_net_to_host_u32 (m->label_exp_s_ttl)));

  return s;
}

u8 * format_mpls_gre_header_with_length (u8 * s, va_list * args)
{
  gre_header_t * h = va_arg (*args, gre_header_t *);
  mpls_unicast_header_t * m = (mpls_unicast_header_t *)(h+1);
  u32 max_header_bytes = va_arg (*args, u32);
  uword header_bytes;

  header_bytes = sizeof (h[0]);
  if (max_header_bytes != 0 && header_bytes > max_header_bytes)
    return format (s, "gre header truncated");

  s = format 
    (s, "GRE-MPLS label %d", 
     vnet_mpls_uc_get_label (clib_net_to_host_u32 (m->label_exp_s_ttl)));

  return s;
}

u8 * format_mpls_gre_header (u8 * s, va_list * args)
{
  gre_header_t * h = va_arg (*args, gre_header_t *);
  return format (s, "%U", format_mpls_gre_header_with_length, h, 0);
}

uword
unformat_mpls_gre_header (unformat_input_t * input, va_list * args)
{
  u8 ** result = va_arg (*args, u8 **);
  gre_header_t _g, * g = &_g;
  mpls_unicast_header_t _h, * h = &_h;
  u32 label, label_exp_s_ttl;
  
  if (! unformat (input, "MPLS %d", &label))
    return 0;

  g->protocol = clib_host_to_net_u16 (GRE_PROTOCOL_mpls_unicast);

  label_exp_s_ttl = (label<<12) | (1<<8) /* s-bit */ | 0xFF;
  h->label_exp_s_ttl = clib_host_to_net_u32 (label_exp_s_ttl);

  /* Add gre, mpls headers to result. */
  {
    void * p;
    u32 g_n_bytes = sizeof (g[0]);
    u32 h_n_bytes = sizeof (h[0]);

    vec_add2 (*result, p, g_n_bytes);
    memcpy (p, g, g_n_bytes);

    vec_add2 (*result, p, h_n_bytes);
    memcpy (p, h, h_n_bytes);
  }
  
  return 1;
}

uword
unformat_mpls_label_net_byte_order (unformat_input_t * input,
                                        va_list * args)
{
  u32 * result = va_arg (*args, u32 *);
  u32 label;

  if (!unformat (input, "MPLS: label %d", &label))
    return 0;

  label = (label<<12) | (1<<8) /* s-bit set */ | 0xFF /* ttl */;

  *result = clib_host_to_net_u32 (label);
  return 1;
}

mpls_encap_t * 
mpls_encap_by_fib_and_dest (mpls_main_t * mm, u32 rx_fib, u32 dst_address)
{
  uword * p;
  mpls_encap_t * e;
  u64 key;

  key = ((u64)rx_fib<<32) | ((u64) dst_address);
  p = hash_get (mm->mpls_encap_by_fib_and_dest, key);

  if (!p)
    return 0;

  e = pool_elt_at_index (mm->encaps, p[0]);
  return e;
}

int vnet_mpls_add_del_encap (ip4_address_t *dest, u32 fib_id, 
                             u32 *labels_host_byte_order,
                             u32 policy_tunnel_index,
                             int no_dst_hash, u32 * indexp, int is_add)
{
  mpls_main_t * mm = &mpls_main;
  ip4_main_t * im = &ip4_main;
  mpls_encap_t * e;
  u32 label_net_byte_order, label_host_byte_order;
  u32 fib_index;
  u64 key;
  uword *p;
  int i;
  
  p = hash_get (im->fib_index_by_table_id, fib_id);
  if (! p)
    return VNET_API_ERROR_NO_SUCH_FIB;
  
  fib_index = p[0];
  
  key = ((u64)fib_index<<32) | ((u64) dest->as_u32);
  
  if (is_add)
    {
      pool_get (mm->encaps, e);
      memset (e, 0, sizeof (*e));
      
      for (i = 0; i < vec_len (labels_host_byte_order); i++)
        {
          mpls_unicast_header_t h;
          label_host_byte_order = labels_host_byte_order[i];
          
          /* Reformat label into mpls_unicast_header_t */
          label_host_byte_order <<= 12;
          if (i == vec_len(labels_host_byte_order) - 1)
            label_host_byte_order |= 1<<8;            /* S=1 */
          label_host_byte_order |= 0xff;            /* TTL=FF */
          label_net_byte_order = clib_host_to_net_u32 (label_host_byte_order);
          h.label_exp_s_ttl = label_net_byte_order;
          vec_add1 (e->labels, h);
        }
      if (no_dst_hash == 0)
        hash_set (mm->mpls_encap_by_fib_and_dest, key, e - mm->encaps);
      if (indexp)
        *indexp = e - mm->encaps;
      if (policy_tunnel_index != ~0)
        return vnet_mpls_policy_tunnel_add_rewrite (mm, e, policy_tunnel_index);
    }
  else
    {
      p = hash_get (mm->mpls_encap_by_fib_and_dest, key);
      if (!p)
        return VNET_API_ERROR_NO_SUCH_LABEL;
      
      e = pool_elt_at_index (mm->encaps, p[0]);
      
      vec_free (e->labels);
      vec_free (e->rewrite);
      pool_put(mm->encaps, e);
      
      if (no_dst_hash == 0)
        hash_unset (mm->mpls_encap_by_fib_and_dest, key);    
    }
  return 0;
}

static clib_error_t *
mpls_add_encap_command_fn (vlib_main_t * vm,
                           unformat_input_t * input,
                           vlib_cli_command_t * cmd)
{
  u32 fib_id;
  u32 *labels = 0;
  u32 this_label;
  ip4_address_t dest;
  u32 policy_tunnel_index = ~0;
  int no_dst_hash = 0;
  int rv;
  int fib_set = 0;
  int dest_set = 0;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "fib %d", &fib_id))
        fib_set = 1;
      else if (unformat (input, "dest %U", unformat_ip4_address, &dest))
        dest_set = 1;
      else if (unformat (input, "no-dst-hash"))
        no_dst_hash = 1;
      else if (unformat (input, "label %d", &this_label))
        vec_add1 (labels, this_label);
      else if (unformat (input, "policy-tunnel %d", &policy_tunnel_index))
        ;
      else
        break;
    }

  if (fib_set == 0)
    return clib_error_return (0, "fib-id missing");
  if (dest_set == 0)
    return clib_error_return (0, "destination IP address missing");
  if (vec_len (labels) == 0)
    return clib_error_return (0, "label stack missing");
  
  rv = vnet_mpls_add_del_encap (&dest, fib_id, labels, 
                                policy_tunnel_index, 
                                no_dst_hash, 0 /* indexp */,
                                1 /* is_add */);
  vec_free (labels);

  switch (rv)
    {
    case 0:
      break;

    case VNET_API_ERROR_NO_SUCH_FIB:
      return clib_error_return (0, "fib id %d unknown", fib_id);
      
    default:
      return clib_error_return (0, "vnet_mpls_add_del_encap returned %d", 
                                rv);
    }

  return 0;
}

VLIB_CLI_COMMAND (mpls_add_encap_command, static) = {
  .path = "mpls encap add",
  .short_help = 
  "mpls encap add label <label> ... fib <id> dest <ip4-address>",
  .function = mpls_add_encap_command_fn,
};

u8 * format_mpls_unicast_header_host_byte_order (u8 * s, va_list * args)
{
  mpls_unicast_header_t *h = va_arg(*args, mpls_unicast_header_t *);
  u32 label = h->label_exp_s_ttl;
  
  s = format (s, "label %d exp %d, s %d, ttl %d",
              vnet_mpls_uc_get_label (label),
              vnet_mpls_uc_get_exp (label),
              vnet_mpls_uc_get_s (label),
              vnet_mpls_uc_get_ttl (label));
  return s;
}

u8 * format_mpls_unicast_header_net_byte_order (u8 * s, va_list * args)
{
  mpls_unicast_header_t *h = va_arg(*args, mpls_unicast_header_t *);
  mpls_unicast_header_t h_host;

  h_host.label_exp_s_ttl = clib_net_to_host_u32 (h->label_exp_s_ttl);

  return format (s, "%U", format_mpls_unicast_header_host_byte_order,
                 &h_host);
}

static clib_error_t *
mpls_del_encap_command_fn (vlib_main_t * vm,
		 unformat_input_t * input,
		 vlib_cli_command_t * cmd)
{
  u32 fib_id;
  ip4_address_t dest;
  int rv;
  
  if (unformat (input, "fib %d dest %U", &fib_id, 
                unformat_ip4_address, &dest)) 
    {
      rv = vnet_mpls_add_del_encap (&dest, fib_id, 0 /* labels */, 
                                    ~0 /* policy_tunnel_index */,
                                    0 /* no_dst_hash */,
                                    0 /* indexp */,
                                    0 /* is_add */);
      switch (rv)
        {
        case VNET_API_ERROR_NO_SUCH_FIB:
          return clib_error_return (0, "fib id %d unknown", fib_id);
        case VNET_API_ERROR_NO_SUCH_ENTRY:
          return clib_error_return (0, "dest %U not in fib %d",
                                    format_ip4_address, &dest, fib_id);
        default:
          break;
        }
      return 0;
    }
  else
    return clib_error_return (0, "unknown input `%U'",
                              format_unformat_error, input);
}

VLIB_CLI_COMMAND (mpls_del_encap_command, static) = {
  .path = "mpls encap delete",
  .short_help = "mpls encap delete fib <id> dest <ip4-address>",
  .function = mpls_del_encap_command_fn,
};

int vnet_mpls_add_del_decap (u32 rx_fib_id, 
                             u32 tx_fib_id,
                             u32 label_host_byte_order, 
                             int s_bit, int next_index, int is_add)
{
  mpls_main_t * mm = &mpls_main;
  ip4_main_t * im = &ip4_main;
  mpls_decap_t * d;
  u32 rx_fib_index, tx_fib_index_or_output_swif_index;
  uword *p;
  u64 key;
  
  p = hash_get (im->fib_index_by_table_id, rx_fib_id);
  if (! p)
    return VNET_API_ERROR_NO_SUCH_FIB;

  rx_fib_index = p[0];

  /* L3 decap => transform fib ID to fib index */
  if (next_index == MPLS_INPUT_NEXT_IP4_INPUT)
    {
      p = hash_get (im->fib_index_by_table_id, tx_fib_id);
      if (! p)
        return VNET_API_ERROR_NO_SUCH_INNER_FIB;
      
      tx_fib_index_or_output_swif_index = p[0];
    }
  else
    {
      /* L2 decap, tx_fib_id is actually the output sw_if_index */
      tx_fib_index_or_output_swif_index = tx_fib_id;
    }

  key = ((u64)rx_fib_index<<32) | ((u64) (label_host_byte_order<<12))
    | ((u64) s_bit<<8);

  p = hash_get (mm->mpls_decap_by_rx_fib_and_label, key);

  /* If deleting, or replacing an old entry */
  if (is_add == 0 || p)
    {
      if (is_add == 0 && p == 0)
        return VNET_API_ERROR_NO_SUCH_LABEL;

      d = pool_elt_at_index (mm->decaps, p[0]);
      hash_unset (mm->mpls_decap_by_rx_fib_and_label, key);
      pool_put (mm->decaps, d);
      /* Deleting, we're done... */
      if (is_add == 0)
        return 0;
    }

  /* add decap entry... */
  pool_get (mm->decaps, d);
  memset (d, 0, sizeof (*d));
  d->tx_fib_index = tx_fib_index_or_output_swif_index;
  d->next_index = next_index;

  hash_set (mm->mpls_decap_by_rx_fib_and_label, key, d - mm->decaps);

  return 0;
}

uword
unformat_mpls_gre_input_next (unformat_input_t * input, va_list * args)
{
  u32 * result = va_arg (*args, u32 *);
  int rv = 0;

  if (unformat (input, "lookup"))
    {
      *result = MPLS_INPUT_NEXT_IP4_INPUT;
      rv = 1;
    }
  else if (unformat (input, "output"))
    {
      *result = MPLS_INPUT_NEXT_L2_OUTPUT;
      rv = 1;
    }
  return rv;
}

static clib_error_t *
mpls_add_decap_command_fn (vlib_main_t * vm,
                           unformat_input_t * input,
                           vlib_cli_command_t * cmd)
{
  vnet_main_t * vnm = vnet_get_main();
  u32 rx_fib_id = 0;
  u32 tx_fib_or_sw_if_index;
  u32 label;
  int s_bit = 1;
  u32 next_index = 1;           /* ip4_lookup, see node.c */
  int tx_fib_id_set = 0;
  int label_set = 0;
  int rv;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "fib %d", &tx_fib_or_sw_if_index))
        tx_fib_id_set = 1;
      else if (unformat (input, "sw_if_index %d", &tx_fib_or_sw_if_index))
        tx_fib_id_set = 1;
      else if (unformat (input, "%U", unformat_vnet_sw_interface, vnm,
                         &tx_fib_or_sw_if_index))
        tx_fib_id_set = 1;
      else if (unformat (input, "rx-fib %d", &rx_fib_id))
        ;
      else if (unformat (input, "label %d", &label))
        label_set = 1;
      else if (unformat (input, "s-bit-clear"))
        s_bit = 0;
      else if (unformat (input, "next %U", unformat_mpls_gre_input_next, 
                         &next_index))
        ;
      else
        break;
    }

  if (tx_fib_id_set == 0)
    return clib_error_return (0, "lookup FIB ID not set");
  if (label_set == 0)
    return clib_error_return (0, "missing label");
  
  rv = vnet_mpls_add_del_decap (rx_fib_id, tx_fib_or_sw_if_index, 
                                label, s_bit, next_index, 1 /* is_add */);
  switch (rv)
    {
    case 0:
      break;

    case VNET_API_ERROR_NO_SUCH_FIB:
      return clib_error_return (0, "no such rx fib id %d", rx_fib_id);

    case VNET_API_ERROR_NO_SUCH_INNER_FIB:
      return clib_error_return (0, "no such tx fib / swif %d", 
                                tx_fib_or_sw_if_index);

    default:
      return clib_error_return (0, "vnet_mpls_add_del_decap returned %d",
                                rv);
    }
  return 0;
}

VLIB_CLI_COMMAND (mpls_add_decap_command, static) = {
    .path = "mpls decap add",
    .short_help = 
    "mpls decap add fib <id> label <nn> [s-bit-clear] [next-index <nn>]",
    .function = mpls_add_decap_command_fn, 
};

static clib_error_t *
mpls_del_decap_command_fn (vlib_main_t * vm,
                           unformat_input_t * input,
                           vlib_cli_command_t * cmd)
{
  u32 rx_fib_id = 0;
  u32 tx_fib_id = 0;
  u32 label;
  int s_bit = 1;
  int label_set = 0;
  int rv;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "rx-fib %d", &rx_fib_id))
        ;
      else if (unformat (input, "label %d", &label))
        label_set = 1;
      else if (unformat (input, "s-bit-clear"))
        s_bit = 0;
    }

  if (!label_set)
    return clib_error_return (0, "label not set");

  rv = vnet_mpls_add_del_decap (rx_fib_id, 
                                tx_fib_id /* not interesting */,
                                label, s_bit, 
                                0 /* next_index not interesting */,
                                0 /* is_add */);
  switch (rv)
    {
    case 0:
      break;

    case VNET_API_ERROR_NO_SUCH_FIB:
      return clib_error_return (0, "no such rx fib id %d", rx_fib_id);

    case VNET_API_ERROR_NO_SUCH_INNER_FIB:
      return clib_error_return (0, "no such lookup fib id %d", tx_fib_id);

    case VNET_API_ERROR_NO_SUCH_LABEL:
      return clib_error_return (0, "no such label %d rx fib id %d", 
                                label, rx_fib_id);

    default:
      return clib_error_return (0, "vnet_mpls_add_del_decap returned %d",
                                rv);
    }
  return 0;
}


VLIB_CLI_COMMAND (mpls_del_decap_command, static) = {
  .path = "mpls decap delete",
  .short_help = "mpls decap delete label <label> rx-fib <id> [s-bit-clear]",
  .function = mpls_del_decap_command_fn,
};

typedef struct {
  u32 fib_index;
  u32 entry_index;
  u32 dest;
  u32 s_bit;
  u32 label;
} show_mpls_fib_t;

static clib_error_t *
show_mpls_fib_command_fn (vlib_main_t * vm,
		 unformat_input_t * input,
		 vlib_cli_command_t * cmd)
{
  u64 key; 
  u32 value;
  show_mpls_fib_t *records = 0;
  show_mpls_fib_t *s;
  mpls_main_t * mm = &mpls_main;
  ip4_main_t * im = &ip4_main;
  ip4_fib_t * rx_fib, * tx_fib;
  u32 tx_table_id;
  char *swif_tag;

  hash_foreach (key, value, mm->mpls_encap_by_fib_and_dest, 
  ({
    vec_add2 (records, s, 1);
    s->fib_index = (u32)(key>>32);
    s->dest = (u32)(key & 0xFFFFFFFF);
    s->entry_index = (u32) value;
  }));

  if (!vec_len(records))
    {
      vlib_cli_output (vm, "MPLS encap table empty");
      goto decap_table;
    }
  /* sort output by dst address within fib */
  vec_sort (records, r0, r1, clib_net_to_host_u32(r0->dest) -
            clib_net_to_host_u32(r1->dest));
  vec_sort (records, r0, r1, r0->fib_index - r1->fib_index);
  vlib_cli_output (vm, "MPLS encap table");
  vlib_cli_output (vm, "%=6s%=16s%=16s", "Table", "Dest address", "Labels");
  vec_foreach (s, records)
    {
      rx_fib = vec_elt_at_index (im->fibs, s->fib_index);
      vlib_cli_output (vm, "%=6d%=16U%=16U", rx_fib->table_id, 
                       format_ip4_address, &s->dest,
                       format_mpls_encap_index, mm, s->entry_index);
    }

 decap_table:
  vec_reset_length(records);

  hash_foreach (key, value, mm->mpls_decap_by_rx_fib_and_label, 
  ({
    vec_add2 (records, s, 1);
    s->fib_index = (u32)(key>>32);
    s->entry_index = (u32) value;
    s->label = ((u32) key)>>12;
    s->s_bit = (key & (1<<8)) != 0;
  }));
  
  if (!vec_len(records))
    {
      vlib_cli_output (vm, "MPLS decap table empty");
      goto out;
    }

  vec_sort (records, r0, r1, r0->label - r1->label);

  vlib_cli_output (vm, "MPLS decap table");
  vlib_cli_output (vm, "%=10s%=15s%=6s%=6s", "RX Table", "TX Table/Intfc", 
                   "Label", "S-bit");
  vec_foreach (s, records)
    {
      mpls_decap_t * d;
      d = pool_elt_at_index (mm->decaps, s->entry_index);
      if (d->next_index == MPLS_INPUT_NEXT_IP4_INPUT)
        {
          tx_fib = vec_elt_at_index (im->fibs, d->tx_fib_index);
          tx_table_id = tx_fib->table_id;
          swif_tag = "     ";
        }
      else
        {
          tx_table_id = d->tx_fib_index;
          swif_tag = "(i)  ";
        }
      rx_fib = vec_elt_at_index (im->fibs, s->fib_index);

      vlib_cli_output (vm, "%=10d%=10d%=5s%=6d%=6d", rx_fib->table_id, 
                       tx_table_id, swif_tag, s->label, s->s_bit);
    }

 out:
  vec_free(records);
  return 0;
}

VLIB_CLI_COMMAND (show_mpls_fib_command, static) = {
    .path = "show mpls fib",
    .short_help = "show mpls fib",
    .function = show_mpls_fib_command_fn,
};

int mpls_fib_reset_labels (u32 fib_id)
{
  u64 key; 
  u32 value;
  show_mpls_fib_t *records = 0;
  show_mpls_fib_t *s;
  mpls_main_t * mm = &mpls_main;
  ip4_main_t * im = &ip4_main;
  u32 fib_index;
  uword *p;

  p = hash_get (im->fib_index_by_table_id, fib_id);
  if (! p)
    return VNET_API_ERROR_NO_SUCH_FIB;

  fib_index = p[0];

  hash_foreach (key, value, mm->mpls_encap_by_fib_and_dest, 
  ({
    if (fib_index == (u32)(key>>32)) {
        vec_add2 (records, s, 1);
        s->dest = (u32)(key & 0xFFFFFFFF);
        s->entry_index = (u32) value;
    }
  }));

  vec_foreach (s, records)
    {
      key = ((u64)fib_index<<32) | ((u64) s->dest);
      hash_unset (mm->mpls_encap_by_fib_and_dest, key);
      pool_put_index (mm->encaps, s->entry_index);
    }
                
  vec_reset_length(records);

  hash_foreach (key, value, mm->mpls_decap_by_rx_fib_and_label, 
  ({
    if (fib_index == (u32) (key>>32)) {
        vec_add2 (records, s, 1);
        s->entry_index = value;
        s->fib_index = fib_index;
        s->s_bit = key & (1<<8);
        s->dest = (u32)((key & 0xFFFFFFFF)>>12);
    }
  }));
  
  vec_foreach (s, records)
    {
      key = ((u64)fib_index <<32) | ((u64)(s->dest<<12)) |
        ((u64)s->s_bit);
      
      hash_unset (mm->mpls_decap_by_rx_fib_and_label, key);
      pool_put_index (mm->decaps, s->entry_index);
    }

  vec_free(records);
  return 0;
}

static clib_error_t * mpls_init (vlib_main_t * vm)
{
  mpls_main_t * mm = &mpls_main;
  clib_error_t * error;

  memset (mm, 0, sizeof (mm[0]));
  mm->vlib_main = vm;
  mm->vnet_main = vnet_get_main();

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

  mm->mpls_encap_by_fib_and_dest = hash_create (0, sizeof (uword));
  mm->mpls_decap_by_rx_fib_and_label = hash_create (0, sizeof (uword));

  return vlib_call_init_function (vm, mpls_input_init);
}

VLIB_INIT_FUNCTION (mpls_init);

mpls_main_t * mpls_get_main (vlib_main_t * vm)
{
  vlib_call_init_function (vm, mpls_init);
  return &mpls_main;
}