core_api_monitor_peers.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2009-2014, 2016 GNUnet e.V.
 
     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     or (at your option) any later version.
 
     GNUnet is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Affero General Public License for more details.
 
     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
     SPDX-License-Identifier: AGPL3.0-or-later
 */
 
#include "platform.h"
#include "gnunet_core_service.h"
#include "core.h"
 
 
struct GNUNET_CORE_MonitorHandle
{
  const struct GNUNET_CONFIGURATION_Handle *cfg;
 
  struct GNUNET_MQ_Handle *mq;
 
  GNUNET_CORE_MonitorCallback peer_cb;
 
  void *peer_cb_cls;
};
 
 
static void
reconnect (struct GNUNET_CORE_MonitorHandle *mh);
 
 
static void
handle_mq_error (void *cls, enum GNUNET_MQ_Error error)
{
  struct GNUNET_CORE_MonitorHandle *mh = cls;
 
  (void) error;
  reconnect (mh);
}
 
 
static void
handle_receive_info (void *cls, const struct MonitorNotifyMessage *mon_message)
{
  struct GNUNET_CORE_MonitorHandle *mh = cls;
 
  mh->peer_cb (mh->peer_cb_cls,
               &mon_message->peer,
               ntohl (mon_message->state),
               GNUNET_TIME_absolute_ntoh (mon_message->timeout));
}
 
 
static void
reconnect (struct GNUNET_CORE_MonitorHandle *mh)
{
  struct GNUNET_MQ_MessageHandler handlers[] =
  { GNUNET_MQ_hd_fixed_size (receive_info,
                             GNUNET_MESSAGE_TYPE_CORE_MONITOR_NOTIFY,
                             struct MonitorNotifyMessage,
                             mh),
    GNUNET_MQ_handler_end () };
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_MessageHeader *msg;
 
  if (NULL != mh->mq)
    GNUNET_MQ_destroy (mh->mq);
  /* FIXME: use backoff? */
  mh->mq =
    GNUNET_CLIENT_connect (mh->cfg, "core", handlers, &handle_mq_error, mh);
  if (NULL == mh->mq)
    return;
  /* notify callback about reconnect */
  if (NULL != mh->peer_cb)
    mh->peer_cb (mh->peer_cb_cls,
                 NULL,
                 GNUNET_CORE_KX_CORE_DISCONNECT,
                 GNUNET_TIME_UNIT_FOREVER_ABS);
  env = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_CORE_MONITOR_PEERS);
  GNUNET_MQ_send (mh->mq, env);
}
 
 
struct GNUNET_CORE_MonitorHandle *
GNUNET_CORE_monitor_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
                           GNUNET_CORE_MonitorCallback peer_cb,
                           void *peer_cb_cls)
{
  struct GNUNET_CORE_MonitorHandle *mh;
 
  GNUNET_assert (NULL != peer_cb);
  mh = GNUNET_new (struct GNUNET_CORE_MonitorHandle);
  mh->cfg = cfg;
  reconnect (mh);
  mh->peer_cb = peer_cb;
  mh->peer_cb_cls = peer_cb_cls;
  if (NULL == mh->mq)
  {
    GNUNET_free (mh);
    return NULL;
  }
  return mh;
}
 
 
void
GNUNET_CORE_monitor_stop (struct GNUNET_CORE_MonitorHandle *mh)
{
  if (NULL != mh->mq)
  {
    GNUNET_MQ_destroy (mh->mq);
    mh->mq = NULL;
  }
  GNUNET_free (mh);
}
 
 
/* end of core_api_monitor_peers.c */