api_shared.c

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/*
 *------------------------------------------------------------------
 * api_shared.c - API message handling, common code for both clients
 * and the vlib process itself.
 *
 *
 * Copyright (c) 2009 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 <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <vppinfra/format.h>
#include <vppinfra/byte_order.h>
#include <vppinfra/error.h>
#include <vlib/vlib.h>
#include <vlib/unix/unix.h>
#include <vlibapi/api.h>
#include <vppinfra/elog.h>

/* *INDENT-OFF* */
api_main_t api_main =
  {
    .region_name = "/unset",
    .api_uid = -1,
    .api_gid = -1,
  };
/* *INDENT-ON* */

void
vl_msg_api_increment_missing_client_counter (void)
{
  api_main_t *am = &api_main;
  am->missing_clients++;
}

int
vl_msg_api_rx_trace_enabled (api_main_t * am)
{
  return (am->rx_trace && am->rx_trace->enabled);
}

int
vl_msg_api_tx_trace_enabled (api_main_t * am)
{
  return (am->tx_trace && am->tx_trace->enabled);
}

/*
 * vl_msg_api_trace
 */
void
vl_msg_api_trace (api_main_t * am, vl_api_trace_t * tp, void *msg)
{
  u8 **this_trace;
  u8 **old_trace;
  u8 *msg_copy;
  u32 length;
  trace_cfg_t *cfgp;
  u16 msg_id = clib_net_to_host_u16 (*((u16 *) msg));
  msgbuf_t *header = (msgbuf_t *) (((u8 *) msg) - offsetof (msgbuf_t, data));

  cfgp = am->api_trace_cfg + msg_id;

  if (!cfgp || !cfgp->trace_enable)
    return;

  msg_copy = 0;

  if (tp->nitems == 0)
    {
      clib_warning ("tp->nitems is 0");
      return;
    }

  if (vec_len (tp->traces) < tp->nitems)
    {
      vec_add1 (tp->traces, 0);
      this_trace = tp->traces + vec_len (tp->traces) - 1;
    }
  else
    {
      tp->wrapped = 1;
      old_trace = tp->traces + tp->curindex++;
      if (tp->curindex == tp->nitems)
        tp->curindex = 0;
      /* Reuse the trace record, may save some memory allocator traffic */
      msg_copy = *old_trace;
      vec_reset_length (msg_copy);
      this_trace = old_trace;
    }

  length = clib_net_to_host_u32 (header->data_len);

  vec_validate (msg_copy, length - 1);
  clib_memcpy_fast (msg_copy, msg, length);
  *this_trace = msg_copy;
}

int
vl_msg_api_trace_onoff (api_main_t * am, vl_api_trace_which_t which,
                        int onoff)
{
  vl_api_trace_t *tp;
  int rv;

  switch (which)
    {
    case VL_API_TRACE_TX:
      tp = am->tx_trace;
      if (tp == 0)
        {
          vl_msg_api_trace_configure (am, which, 1024);
          tp = am->tx_trace;
        }
      break;

    case VL_API_TRACE_RX:
      tp = am->rx_trace;
      if (tp == 0)
        {
          vl_msg_api_trace_configure (am, which, 1024);
          tp = am->rx_trace;
        }
      break;

    default:
      /* duh? */
      return -1;
    }

  /* Configured? */
  if (tp == 0 || tp->nitems == 0)
    return -1;

  rv = tp->enabled;
  tp->enabled = onoff;

  return rv;
}

int
vl_msg_api_trace_free (api_main_t * am, vl_api_trace_which_t which)
{
  vl_api_trace_t *tp;
  int i;

  switch (which)
    {
    case VL_API_TRACE_TX:
      tp = am->tx_trace;
      break;

    case VL_API_TRACE_RX:
      tp = am->rx_trace;
      break;

    default:
      /* duh? */
      return -1;
    }

  /* Configured? */
  if (!tp || tp->nitems == 0)
    return -1;

  tp->curindex = 0;
  tp->wrapped = 0;

  for (i = 0; i < vec_len (tp->traces); i++)
    {
      vec_free (tp->traces[i]);
    }
  vec_free (tp->traces);

  return 0;
}

u8 *
vl_api_serialize_message_table (api_main_t * am, u8 * vector)
{
  serialize_main_t _sm, *sm = &_sm;
  hash_pair_t *hp;
  u32 nmsg = hash_elts (am->msg_index_by_name_and_crc);

  serialize_open_vector (sm, vector);

  /* serialize the count */
  serialize_integer (sm, nmsg, sizeof (u32));

  /* *INDENT-OFF* */
  hash_foreach_pair (hp, am->msg_index_by_name_and_crc,
  ({
    serialize_likely_small_unsigned_integer (sm, hp->value[0]);
    serialize_cstring (sm, (char *) hp->key);
  }));
  /* *INDENT-ON* */

  return serialize_close_vector (sm);
}

int
vl_msg_api_trace_save (api_main_t * am, vl_api_trace_which_t which, FILE * fp)
{
  vl_api_trace_t *tp;
  vl_api_trace_file_header_t fh;
  int i;
  u8 *msg;

  switch (which)
    {
    case VL_API_TRACE_TX:
      tp = am->tx_trace;
      break;

    case VL_API_TRACE_RX:
      tp = am->rx_trace;
      break;

    default:
      /* duh? */
      return -1;
    }

  /* Configured, data present? */
  if (tp == 0 || tp->nitems == 0 || vec_len (tp->traces) == 0)
    return -1;

  /* "Dare to be stupid" check */
  if (fp == 0)
    {
      return -2;
    }

  /* Write the file header */
  fh.wrapped = tp->wrapped;
  fh.nitems = clib_host_to_net_u32 (vec_len (tp->traces));
  u8 *m = vl_api_serialize_message_table (am, 0);
  clib_warning ("Message table length %d", vec_len (m));
  fh.msgtbl_size = clib_host_to_net_u32 (vec_len (m));

  if (fwrite (&fh, sizeof (fh), 1, fp) != 1)
    {
      return (-10);
    }

  /* Write the message table */
  if (fwrite (m, vec_len (m), 1, fp) != 1)
    {
      return (-14);
    }
  vec_free (m);

  /* No-wrap case */
  if (tp->wrapped == 0)
    {
      /*
       * Note: vec_len return 0 when fed a NULL pointer.
       * Unfortunately, the static analysis tool doesn't
       * figure it out, hence the suppressed warnings.
       * What a great use of my time.
       */
      for (i = 0; i < vec_len (tp->traces); i++)
        {
          u32 msg_length;
          /*sa_ignore NO_NULL_CHK */
          msg = tp->traces[i];
          /*
           * This retarded check required to pass
           * [sic] SA-checking.
           */
          if (!msg)
            continue;

          msg_length = clib_host_to_net_u32 (vec_len (msg));
          if (fwrite (&msg_length, 1, sizeof (msg_length), fp)
              != sizeof (msg_length))
            {
              return (-14);
            }
          if (fwrite (msg, 1, vec_len (msg), fp) != vec_len (msg))
            {
              return (-11);
            }
        }
    }
  else
    {
      /* Wrap case: write oldest -> end of buffer */
      for (i = tp->curindex; i < vec_len (tp->traces); i++)
        {
          u32 msg_length;
          msg = tp->traces[i];
          /*
           * This retarded check required to pass
           * [sic] SA-checking
           */
          if (!msg)
            continue;

          msg_length = clib_host_to_net_u32 (vec_len (msg));
          if (fwrite (&msg_length, 1, sizeof (msg_length), fp)
              != sizeof (msg_length))
            {
              return (-14);
            }

          if (fwrite (msg, 1, vec_len (msg), fp) != vec_len (msg))
            {
              return (-12);
            }
        }
      /* write beginning of buffer -> oldest-1 */
      for (i = 0; i < tp->curindex; i++)
        {
          u32 msg_length;
          /*sa_ignore NO_NULL_CHK */
          msg = tp->traces[i];
          /*
           * This retarded check required to pass
           * [sic] SA-checking
           */
          if (!msg)
            continue;

          msg_length = clib_host_to_net_u32 (vec_len (msg));
          if (fwrite (&msg_length, 1, sizeof (msg_length), fp)
              != sizeof (msg_length))
            {
              return (-14);
            }

          if (fwrite (msg, 1, vec_len (msg), fp) != vec_len (msg))
            {
              return (-13);
            }
        }
    }
  return 0;
}

int
vl_msg_api_trace_configure (api_main_t * am, vl_api_trace_which_t which,
                            u32 nitems)
{
  vl_api_trace_t *tp;
  int was_on = 0;

  switch (which)
    {
    case VL_API_TRACE_TX:
      tp = am->tx_trace;
      if (tp == 0)
        {
          vec_validate (am->tx_trace, 0);
          tp = am->tx_trace;
        }
      break;

    case VL_API_TRACE_RX:
      tp = am->rx_trace;
      if (tp == 0)
        {
          vec_validate (am->rx_trace, 0);
          tp = am->rx_trace;
        }

      break;

    default:
      return -1;

    }

  if (tp->enabled)
    {
      was_on = vl_msg_api_trace_onoff (am, which, 0);
    }
  if (tp->traces)
    {
      vl_msg_api_trace_free (am, which);
    }

  clib_memset (tp, 0, sizeof (*tp));

  if (clib_arch_is_big_endian)
    {
      tp->endian = VL_API_BIG_ENDIAN;
    }
  else
    {
      tp->endian = VL_API_LITTLE_ENDIAN;
    }

  tp->nitems = nitems;
  if (was_on)
    {
      (void) vl_msg_api_trace_onoff (am, which, was_on);
    }
  return 0;
}

void
vl_msg_api_barrier_sync (void)
{
}

void
vl_msg_api_barrier_release (void)
{
}

always_inline void
msg_handler_internal (api_main_t * am,
                      void *the_msg, int trace_it, int do_it, int free_it)
{
  u16 id = clib_net_to_host_u16 (*((u16 *) the_msg));
  u8 *(*print_fp) (void *, void *);

  if (PREDICT_FALSE (am->elog_trace_api_messages))
    {
      /* *INDENT-OFF* */
      ELOG_TYPE_DECLARE (e) =
        {
          .format = "api-msg: %s",
          .format_args = "T4",
        };
      /* *INDENT-ON* */
      struct
      {
        u32 c;
      } *ed;
      ed = ELOG_DATA (am->elog_main, e);
      if (id < vec_len (am->msg_names))
        ed->c = elog_string (am->elog_main, (char *) am->msg_names[id]);
      else
        ed->c = elog_string (am->elog_main, "BOGUS");
    }

  if (id < vec_len (am->msg_handlers) && am->msg_handlers[id])
    {
      if (trace_it)
        vl_msg_api_trace (am, am->rx_trace, the_msg);

      if (am->msg_print_flag)
        {
          fformat (stdout, "[%d]: %s\n", id, am->msg_names[id]);
          print_fp = (void *) am->msg_print_handlers[id];
          if (print_fp == 0)
            {
              fformat (stdout, "  [no registered print fn]\n");
            }
          else
            {
              (*print_fp) (the_msg, stdout);
            }
        }

      if (do_it)
        {
          if (!am->is_mp_safe[id])
            {
              vl_msg_api_barrier_trace_context (am->msg_names[id]);
              vl_msg_api_barrier_sync ();
            }
          (*am->msg_handlers[id]) (the_msg);
          if (!am->is_mp_safe[id])
            vl_msg_api_barrier_release ();
        }
    }
  else
    {
      clib_warning ("no handler for msg id %d", id);
    }

  if (free_it)
    vl_msg_api_free (the_msg);

  if (PREDICT_FALSE (am->elog_trace_api_messages))
    {
      /* *INDENT-OFF* */
      ELOG_TYPE_DECLARE (e) =
        {
          .format = "api-msg-done(%s): %s",
          .format_args = "t4T4",
          .n_enum_strings = 2,
          .enum_strings =
          {
            "barrier",
            "mp-safe",
          }
        };
      /* *INDENT-ON* */

      struct
      {
        u32 barrier;
        u32 c;
      } *ed;
      ed = ELOG_DATA (am->elog_main, e);
      if (id < vec_len (am->msg_names))
        {
          ed->c = elog_string (am->elog_main, (char *) am->msg_names[id]);
          ed->barrier = !am->is_mp_safe[id];
        }
      else
        {
          ed->c = elog_string (am->elog_main, "BOGUS");
          ed->barrier = 0;
        }
    }
}

/* This is only to be called from a vlib/vnet app */
void
vl_msg_api_handler_with_vm_node (api_main_t * am,
                                 void *the_msg, vlib_main_t * vm,
                                 vlib_node_runtime_t * node)
{
  u16 id = clib_net_to_host_u16 (*((u16 *) the_msg));
  u8 *(*handler) (void *, void *, void *);
  u8 *(*print_fp) (void *, void *);
  int is_mp_safe = 1;

  if (PREDICT_FALSE (am->elog_trace_api_messages))
    {
      /* *INDENT-OFF* */
      ELOG_TYPE_DECLARE (e) =
        {
          .format = "api-msg: %s",
          .format_args = "T4",
        };
      /* *INDENT-ON* */
      struct
      {
        u32 c;
      } *ed;
      ed = ELOG_DATA (am->elog_main, e);
      if (id < vec_len (am->msg_names))
        ed->c = elog_string (am->elog_main, (char *) am->msg_names[id]);
      else
        ed->c = elog_string (am->elog_main, "BOGUS");
    }

  if (id < vec_len (am->msg_handlers) && am->msg_handlers[id])
    {
      handler = (void *) am->msg_handlers[id];

      if (PREDICT_FALSE (am->rx_trace && am->rx_trace->enabled))
        vl_msg_api_trace (am, am->rx_trace, the_msg);

      if (PREDICT_FALSE (am->msg_print_flag))
        {
          fformat (stdout, "[%d]: %s\n", id, am->msg_names[id]);
          print_fp = (void *) am->msg_print_handlers[id];
          if (print_fp == 0)
            {
              fformat (stdout, "  [no registered print fn for msg %d]\n", id);
            }
          else
            {
              (*print_fp) (the_msg, vm);
            }
        }
      is_mp_safe = am->is_mp_safe[id];

      if (!is_mp_safe)
        {
          vl_msg_api_barrier_trace_context (am->msg_names[id]);
          vl_msg_api_barrier_sync ();
        }
      (*handler) (the_msg, vm, node);
      if (!is_mp_safe)
        vl_msg_api_barrier_release ();
    }
  else
    {
      clib_warning ("no handler for msg id %d", id);
    }

  /*
   * Special-case, so we can e.g. bounce messages off the vnet
   * main thread without copying them...
   */
  if (!(am->message_bounce[id]))
    vl_msg_api_free (the_msg);

  if (PREDICT_FALSE (am->elog_trace_api_messages))
    {
      /* *INDENT-OFF* */
      ELOG_TYPE_DECLARE (e) =
        {
          .format = "api-msg-done(%s): %s",
          .format_args = "t4T4",
          .n_enum_strings = 2,
          .enum_strings =
          {
            "barrier",
            "mp-safe",
          }
        };
      /* *INDENT-ON* */

      struct
      {
        u32 barrier;
        u32 c;
      } *ed;
      ed = ELOG_DATA (am->elog_main, e);
      if (id < vec_len (am->msg_names))
        ed->c = elog_string (am->elog_main, (char *) am->msg_names[id]);
      else
        ed->c = elog_string (am->elog_main, "BOGUS");
      ed->barrier = is_mp_safe;
    }
}

void
vl_msg_api_handler (void *the_msg)
{
  api_main_t *am = &api_main;

  msg_handler_internal (am, the_msg,
                        (am->rx_trace
                         && am->rx_trace->enabled) /* trace_it */ ,
                        1 /* do_it */ , 1 /* free_it */ );
}

void
vl_msg_api_handler_no_free (void *the_msg)
{
  api_main_t *am = &api_main;
  msg_handler_internal (am, the_msg,
                        (am->rx_trace
                         && am->rx_trace->enabled) /* trace_it */ ,
                        1 /* do_it */ , 0 /* free_it */ );
}

void
vl_msg_api_handler_no_trace_no_free (void *the_msg)
{
  api_main_t *am = &api_main;
  msg_handler_internal (am, the_msg, 0 /* trace_it */ , 1 /* do_it */ ,
                        0 /* free_it */ );
}

/*
 * Add a trace record to the API message trace buffer, if
 * API message tracing is enabled. Handy for adding sufficient
 * data to the trace to reproduce autonomous state, as opposed to
 * state downloaded via control-plane API messages. Example: the NAT
 * application creates database entries based on packet traffic, not
 * control-plane messages.
 *
 */
void
vl_msg_api_trace_only (void *the_msg)
{
  api_main_t *am = &api_main;

  msg_handler_internal (am, the_msg,
                        (am->rx_trace
                         && am->rx_trace->enabled) /* trace_it */ ,
                        0 /* do_it */ , 0 /* free_it */ );
}

void
vl_msg_api_cleanup_handler (void *the_msg)
{
  api_main_t *am = &api_main;
  u16 id = clib_net_to_host_u16 (*((u16 *) the_msg));

  if (PREDICT_FALSE (id >= vec_len (am->msg_cleanup_handlers)))
    {
      clib_warning ("_vl_msg_id too large: %d\n", id);
      return;
    }
  if (am->msg_cleanup_handlers[id])
    (*am->msg_cleanup_handlers[id]) (the_msg);

  vl_msg_api_free (the_msg);
}

/*
 * vl_msg_api_replay_handler
 */
void
vl_msg_api_replay_handler (void *the_msg)
{
  api_main_t *am = &api_main;

  u16 id = clib_net_to_host_u16 (*((u16 *) the_msg));

  if (PREDICT_FALSE (id >= vec_len (am->msg_handlers)))
    {
      clib_warning ("_vl_msg_id too large: %d\n", id);
      return;
    }
  /* do NOT trace the message... */
  if (am->msg_handlers[id])
    (*am->msg_handlers[id]) (the_msg);
  /* do NOT free the message buffer... */
}

u32
vl_msg_api_get_msg_length (void *msg_arg)
{
  return vl_msg_api_get_msg_length_inline (msg_arg);
}

/*
 * vl_msg_api_socket_handler
 */
void
vl_msg_api_socket_handler (void *the_msg)
{
  api_main_t *am = &api_main;

  msg_handler_internal (am, the_msg,
                        (am->rx_trace
                         && am->rx_trace->enabled) /* trace_it */ ,
                        1 /* do_it */ , 0 /* free_it */ );
}

#define foreach_msg_api_vector                  \
_(msg_names)                                    \
_(msg_handlers)                                 \
_(msg_cleanup_handlers)                         \
_(msg_endian_handlers)                          \
_(msg_print_handlers)                           \
_(api_trace_cfg)                                \
_(message_bounce)                               \
_(is_mp_safe)

void
vl_msg_api_config (vl_msg_api_msg_config_t * c)
{
  api_main_t *am = &api_main;

  /*
   * This happens during the java core tests if the message
   * dictionary is missing newly added xxx_reply_t messages.
   * Should never happen, but since I shot myself in the foot once
   * this way, I thought I'd make it easy to debug if I ever do
   * it again... (;-)...
   */
  if (c->id == 0)
    {
      if (c->name)
        clib_warning ("Trying to register %s with a NULL msg id!", c->name);
      else
        clib_warning ("Trying to register a NULL msg with a NULL msg id!");
      clib_warning ("Did you forget to call setup_message_id_table?");
      return;
    }

#define _(a) vec_validate (am->a, c->id);
  foreach_msg_api_vector;
#undef _

  if (am->msg_handlers[c->id] && am->msg_handlers[c->id] != c->handler)
    clib_warning
      ("BUG: re-registering 'vl_api_%s_t_handler'."
       "Handler was %llx, replaced by %llx",
       c->name, am->msg_handlers[c->id], c->handler);

  am->msg_names[c->id] = c->name;
  am->msg_handlers[c->id] = c->handler;
  am->msg_cleanup_handlers[c->id] = c->cleanup;
  am->msg_endian_handlers[c->id] = c->endian;
  am->msg_print_handlers[c->id] = c->print;
  am->message_bounce[c->id] = c->message_bounce;
  am->is_mp_safe[c->id] = c->is_mp_safe;

  am->api_trace_cfg[c->id].size = c->size;
  am->api_trace_cfg[c->id].trace_enable = c->traced;
  am->api_trace_cfg[c->id].replay_enable = c->replay;
}

/*
 * vl_msg_api_set_handlers
 * preserve the old API for a while
 */
void
vl_msg_api_set_handlers (int id, char *name, void *handler, void *cleanup,
                         void *endian, void *print, int size, int traced)
{
  vl_msg_api_msg_config_t cfg;
  vl_msg_api_msg_config_t *c = &cfg;

  clib_memset (c, 0, sizeof (*c));

  c->id = id;
  c->name = name;
  c->handler = handler;
  c->cleanup = cleanup;
  c->endian = endian;
  c->print = print;
  c->traced = traced;
  c->replay = 1;
  c->message_bounce = 0;
  c->is_mp_safe = 0;
  vl_msg_api_config (c);
}

void
vl_msg_api_clean_handlers (int msg_id)
{
  vl_msg_api_msg_config_t cfg;
  vl_msg_api_msg_config_t *c = &cfg;

  clib_memset (c, 0, sizeof (*c));

  c->id = msg_id;
  vl_msg_api_config (c);
}

void
vl_msg_api_set_cleanup_handler (int msg_id, void *fp)
{
  api_main_t *am = &api_main;
  ASSERT (msg_id > 0);

  vec_validate (am->msg_cleanup_handlers, msg_id);
  am->msg_cleanup_handlers[msg_id] = fp;
}

void
vl_msg_api_queue_handler (svm_queue_t * q)
{
  uword msg;

  while (!svm_queue_sub (q, (u8 *) & msg, SVM_Q_WAIT, 0))
    vl_msg_api_handler ((void *) msg);
}

vl_api_trace_t *
vl_msg_api_trace_get (api_main_t * am, vl_api_trace_which_t which)
{
  switch (which)
    {
    case VL_API_TRACE_RX:
      return am->rx_trace;
    case VL_API_TRACE_TX:
      return am->tx_trace;
    default:
      return 0;
    }
}

void
vl_noop_handler (void *mp)
{
}


static u8 post_mortem_dump_enabled;

void
vl_msg_api_post_mortem_dump_enable_disable (int enable)
{
  post_mortem_dump_enabled = enable;
}

void
vl_msg_api_post_mortem_dump (void)
{
  api_main_t *am = &api_main;
  FILE *fp;
  char filename[64];
  int rv;

  if (post_mortem_dump_enabled == 0)
    return;

  snprintf (filename, sizeof (filename), "/tmp/api_post_mortem.%d",
            getpid ());

  fp = fopen (filename, "w");
  if (fp == NULL)
    {
      rv = write (2, "Couldn't create ", 16);
      rv = write (2, filename, strlen (filename));
      rv = write (2, "\n", 1);
      return;
    }
  rv = vl_msg_api_trace_save (am, VL_API_TRACE_RX, fp);
  fclose (fp);
  if (rv < 0)
    {
      rv = write (2, "Failed to save post-mortem API trace to ", 40);
      rv = write (2, filename, strlen (filename));
      rv = write (2, "\n", 1);
    }

}

/* Layered message handling support */

void
vl_msg_api_register_pd_handler (void *fp, u16 msg_id_host_byte_order)
{
  api_main_t *am = &api_main;

  /* Mild idiot proofing */
  if (msg_id_host_byte_order > 10000)
    clib_warning ("msg_id_host_byte_order endian issue? %d arg vs %d",
                  msg_id_host_byte_order,
                  clib_net_to_host_u16 (msg_id_host_byte_order));
  vec_validate (am->pd_msg_handlers, msg_id_host_byte_order);
  am->pd_msg_handlers[msg_id_host_byte_order] = fp;
}

int
vl_msg_api_pd_handler (void *mp, int rv)
{
  api_main_t *am = &api_main;
  int (*fp) (void *, int);
  u16 msg_id;

  if (clib_arch_is_little_endian)
    msg_id = clib_net_to_host_u16 (*((u16 *) mp));
  else
    msg_id = *((u16 *) mp);

  if (msg_id >= vec_len (am->pd_msg_handlers)
      || am->pd_msg_handlers[msg_id] == 0)
    return rv;

  fp = am->pd_msg_handlers[msg_id];
  rv = (*fp) (mp, rv);
  return rv;
}

void
vl_msg_api_set_first_available_msg_id (u16 first_avail)
{
  api_main_t *am = &api_main;

  am->first_available_msg_id = first_avail;
}

u16
vl_msg_api_get_msg_ids (const char *name, int n)
{
  api_main_t *am = &api_main;
  u8 *name_copy;
  vl_api_msg_range_t *rp;
  uword *p;
  u16 rv;

  if (am->msg_range_by_name == 0)
    am->msg_range_by_name = hash_create_string (0, sizeof (uword));

  name_copy = format (0, "%s%c", name, 0);

  p = hash_get_mem (am->msg_range_by_name, name_copy);
  if (p)
    {
      clib_warning ("WARNING: duplicate message range registration for '%s'",
                    name_copy);
      vec_free (name_copy);
      return ((u16) ~ 0);
    }

  if (n < 0 || n > 1024)
    {
      clib_warning
        ("WARNING: bad number of message-IDs (%d) requested by '%s'",
         n, name_copy);
      vec_free (name_copy);
      return ((u16) ~ 0);
    }

  vec_add2 (am->msg_ranges, rp, 1);

  rv = rp->first_msg_id = am->first_available_msg_id;
  am->first_available_msg_id += n;
  rp->last_msg_id = am->first_available_msg_id - 1;
  rp->name = name_copy;

  hash_set_mem (am->msg_range_by_name, name_copy, rp - am->msg_ranges);

  return rv;
}

void
vl_msg_api_add_msg_name_crc (api_main_t * am, const char *string, u32 id)
{
  uword *p;

  if (am->msg_index_by_name_and_crc == 0)
    am->msg_index_by_name_and_crc = hash_create_string (0, sizeof (uword));

  p = hash_get_mem (am->msg_index_by_name_and_crc, string);
  if (p)
    {
      clib_warning ("attempt to redefine '%s' ignored...", string);
      return;
    }

  hash_set_mem (am->msg_index_by_name_and_crc, string, id);
}

void
vl_msg_api_add_version (api_main_t * am, const char *string,
                        u32 major, u32 minor, u32 patch)
{
  api_version_t version = {.major = major,.minor = minor,.patch = patch };
  ASSERT (strlen (string) < 64);
  strncpy (version.name, string, 64 - 1);
  vec_add1 (am->api_version_list, version);
}

u32
vl_msg_api_get_msg_index (u8 * name_and_crc)
{
  api_main_t *am = &api_main;
  uword *p;

  if (am->msg_index_by_name_and_crc)
    {
      p = hash_get_mem (am->msg_index_by_name_and_crc, name_and_crc);
      if (p)
        return p[0];
    }
  return ~0;
}

void *
vl_msg_push_heap (void)
{
  api_main_t *am = &api_main;
  pthread_mutex_lock (&am->vlib_rp->mutex);
  return svm_push_data_heap (am->vlib_rp);
}

void
vl_msg_pop_heap (void *oldheap)
{
  api_main_t *am = &api_main;
  svm_pop_heap (oldheap);
  pthread_mutex_unlock (&am->vlib_rp->mutex);
}

int
vl_api_to_api_string (u32 len, const char *buf, vl_api_string_t * str)
{
  clib_memcpy_fast (str->buf, buf, len);
  str->length = htonl (len);
  return len + sizeof (u32);
}

int
vl_api_vec_to_api_string (const u8 * vec, vl_api_string_t * str)
{
  u32 len = vec_len (vec);
  clib_memcpy (str->buf, vec, len);
  str->length = htonl (len);
  return len + sizeof (u32);
}

/* Return a pointer to the API string (not nul terminated */
u8 *
vl_api_from_api_string (vl_api_string_t * astr)
{
  return astr->buf;
}

u32
vl_api_string_len (vl_api_string_t * astr)
{
  return clib_net_to_host_u32 (astr->length);
}

/*
 * Returns a new vector. Remember to free it after use.
 */
u8 *
vl_api_from_api_to_vec (vl_api_string_t * astr)
{
  u8 *v = 0;
  vec_add (v, astr->buf, clib_net_to_host_u32 (astr->length));
  return v;
}

void
vl_api_set_elog_main (elog_main_t * m)
{
  api_main_t *am = &api_main;
  am->elog_main = m;
}

int
vl_api_set_elog_trace_api_messages (int enable)
{
  int rv;
  api_main_t *am = &api_main;

  rv = am->elog_trace_api_messages;
  am->elog_trace_api_messages = enable;
  return rv;
}

int
vl_api_get_elog_trace_api_messages (void)
{
  api_main_t *am = &api_main;

  return am->elog_trace_api_messages;
}

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */