transport_api2_monitor.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2018 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_util_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_transport_monitor_service.h"
#include "transport.h"
 
 
struct GNUNET_TRANSPORT_MonitorContext
{
  const struct GNUNET_CONFIGURATION_Handle *cfg;
 
  struct GNUNET_MQ_Handle *mq;
 
  struct GNUNET_PeerIdentity peer;
 
  int one_shot;
 
  GNUNET_TRANSPORT_MonitorCallback cb;
 
  void *cb_cls;
};
 
 
static void
reconnect (struct GNUNET_TRANSPORT_MonitorContext *mc);
 
 
static void
send_start_monitor (struct GNUNET_TRANSPORT_MonitorContext *mc)
{
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_TRANSPORT_MonitorStart *smm;
 
  if (NULL == mc->mq)
    return;
  env = GNUNET_MQ_msg (smm, GNUNET_MESSAGE_TYPE_TRANSPORT_MONITOR_START);
  smm->one_shot = htonl ((uint32_t) mc->one_shot);
  smm->peer = mc->peer;
  GNUNET_MQ_send (mc->mq, env);
}
 
 
static void
disconnect (struct GNUNET_TRANSPORT_MonitorContext *mc)
{
  if (NULL == mc->mq)
    return;
  GNUNET_MQ_destroy (mc->mq);
  mc->mq = NULL;
}
 
 
static void
error_handler (void *cls, enum GNUNET_MQ_Error error)
{
  struct GNUNET_TRANSPORT_MonitorContext *mc = cls;
 
  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
              "MQ failure %d, reconnecting to transport service.\n",
              error);
  disconnect (mc);
  /* TODO: maybe do this with exponential backoff/delay */
  reconnect (mc);
}
 
 
static int
check_monitor_data (void *cls, const struct GNUNET_TRANSPORT_MonitorData *md)
{
  (void) cls;
  GNUNET_MQ_check_zero_termination (md);
  return GNUNET_OK;
}
 
 
static void
handle_monitor_data (void *cls, const struct GNUNET_TRANSPORT_MonitorData *md)
{
  struct GNUNET_TRANSPORT_MonitorContext *mc = cls;
  struct GNUNET_TRANSPORT_MonitorInformation mi;
 
  mi.address = (const char *) &md[1];
  mi.nt = ntohl (md->nt);
  mi.cs = ntohl (md->cs);
  mi.num_msg_pending = ntohl (md->num_msg_pending);
  mi.num_bytes_pending = ntohl (md->num_bytes_pending);
  mi.last_validation = GNUNET_TIME_absolute_ntoh (md->last_validation);
  mi.valid_until = GNUNET_TIME_absolute_ntoh (md->valid_until);
  mi.next_validation = GNUNET_TIME_absolute_ntoh (md->next_validation);
  mi.rtt = GNUNET_TIME_relative_ntoh (md->rtt);
  mc->cb (mc->cb_cls, &md->peer, &mi);
}
 
 
static void
handle_monitor_end (void *cls, const struct GNUNET_MessageHeader *me)
{
  struct GNUNET_TRANSPORT_MonitorContext *mc = cls;
 
  if (GNUNET_YES != mc->one_shot)
  {
    GNUNET_break (0);
    disconnect (mc);
    reconnect (mc);
    return;
  }
  mc->cb (mc->cb_cls, NULL, NULL);
  GNUNET_TRANSPORT_monitor_cancel (mc);
}
 
 
static void
reconnect (struct GNUNET_TRANSPORT_MonitorContext *mc)
{
  struct GNUNET_MQ_MessageHandler handlers[] =
  { GNUNET_MQ_hd_var_size (monitor_data,
                           GNUNET_MESSAGE_TYPE_TRANSPORT_MONITOR_DATA,
                           struct GNUNET_TRANSPORT_MonitorData,
                           mc),
    GNUNET_MQ_hd_fixed_size (monitor_end,
                             GNUNET_MESSAGE_TYPE_TRANSPORT_MONITOR_END,
                             struct GNUNET_MessageHeader,
                             mc),
    GNUNET_MQ_handler_end () };
 
  mc->mq =
    GNUNET_CLIENT_connect (mc->cfg, "transport", handlers, &error_handler, mc);
  if (NULL == mc->mq)
    return;
  send_start_monitor (mc);
}
 
 
struct GNUNET_TRANSPORT_MonitorContext *
GNUNET_TRANSPORT_monitor (const struct GNUNET_CONFIGURATION_Handle *cfg,
                          const struct GNUNET_PeerIdentity *peer,
                          int one_shot,
                          GNUNET_TRANSPORT_MonitorCallback cb,
                          void *cb_cls)
{
  struct GNUNET_TRANSPORT_MonitorContext *mc;
 
  mc = GNUNET_new (struct GNUNET_TRANSPORT_MonitorContext);
  mc->cfg = cfg;
  if (NULL != peer)
    mc->peer = *peer;
  mc->one_shot = one_shot;
  mc->cb = cb;
  mc->cb_cls = cb_cls;
  reconnect (mc);
  if (NULL == mc->mq)
  {
    GNUNET_free (mc);
    return NULL;
  }
  return mc;
}
 
 
void
GNUNET_TRANSPORT_monitor_cancel (struct GNUNET_TRANSPORT_MonitorContext *mc)
{
  disconnect (mc);
  GNUNET_free (mc);
}
 
 
/* end of transport_api2_monitor.c */