arm_monitor_api.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2009, 2010, 2012, 2013, 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_arm_service.h"
#include "gnunet_util_lib.h"
#include "gnunet_protocols.h"
#include "arm.h"

#define INIT_TIMEOUT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5)

#define LOG(kind, ...) GNUNET_log_from(kind, "arm-monitor-api", __VA_ARGS__)

struct GNUNET_ARM_MonitorHandle {
  struct GNUNET_MQ_Handle *mq;

  const struct GNUNET_CONFIGURATION_Handle *cfg;

  struct GNUNET_SCHEDULER_Task *reconnect_task;

  struct GNUNET_TIME_Relative retry_backoff;

  GNUNET_ARM_ServiceStatusCallback service_status;

  void *service_status_cls;
};


static int
reconnect_arm_monitor(struct GNUNET_ARM_MonitorHandle *h);


static void
reconnect_arm_monitor_task(void *cls)
{
  struct GNUNET_ARM_MonitorHandle *h = cls;

  h->reconnect_task = NULL;
  LOG(GNUNET_ERROR_TYPE_DEBUG,
      "Connecting to ARM service for monitoring after delay\n");
  GNUNET_break(GNUNET_OK == reconnect_arm_monitor(h));
}


static void
reconnect_arm_monitor_later(struct GNUNET_ARM_MonitorHandle *h)
{
  if (NULL != h->mq)
    {
      GNUNET_MQ_destroy(h->mq);
      h->mq = NULL;
    }
  GNUNET_assert(NULL == h->reconnect_task);
  h->reconnect_task = GNUNET_SCHEDULER_add_delayed(h->retry_backoff,
                                                   &reconnect_arm_monitor_task,
                                                   h);
  h->retry_backoff = GNUNET_TIME_STD_BACKOFF(h->retry_backoff);
}


static int
check_monitor_notify(void *cls, const struct GNUNET_ARM_StatusMessage *msg)
{
  size_t sl =
    ntohs(msg->header.size) - sizeof(struct GNUNET_ARM_StatusMessage);
  const char *name = (const char *)&msg[1];

  (void)cls;
  if ((0 == sl) || ('\0' != name[sl - 1]))
    {
      GNUNET_break(0);
      return GNUNET_SYSERR;
    }
  return GNUNET_OK;
}


static void
handle_monitor_notify(void *cls, const struct GNUNET_ARM_StatusMessage *res)
{
  struct GNUNET_ARM_MonitorHandle *h = cls;
  enum GNUNET_ARM_ServiceStatus status;

  status = (enum GNUNET_ARM_ServiceStatus)ntohl(res->status);
  LOG(GNUNET_ERROR_TYPE_DEBUG,
      "Received notification from ARM for service `%s' with status %d\n",
      (const char *)&res[1],
      (int)status);
  if (NULL != h->service_status)
    h->service_status(h->service_status_cls, (const char *)&res[1], status);
}


static void
mq_error_handler(void *cls, enum GNUNET_MQ_Error error)
{
  struct GNUNET_ARM_MonitorHandle *h = cls;

  (void)error;
  reconnect_arm_monitor_later(h);
}


static int
reconnect_arm_monitor(struct GNUNET_ARM_MonitorHandle *h)
{
  struct GNUNET_MQ_MessageHandler handlers[] =
  { GNUNET_MQ_hd_var_size(monitor_notify,
                          GNUNET_MESSAGE_TYPE_ARM_STATUS,
                          struct GNUNET_ARM_StatusMessage,
                          h),
    GNUNET_MQ_handler_end() };
  struct GNUNET_MessageHeader *msg;
  struct GNUNET_MQ_Envelope *env;

  GNUNET_assert(NULL == h->mq);
  h->mq = GNUNET_CLIENT_connect(h->cfg, "arm", handlers, &mq_error_handler, h);
  if (NULL == h->mq)
    {
      if (NULL != h->service_status)
        h->service_status(h->service_status_cls,
                          NULL,
                          GNUNET_ARM_SERVICE_STOPPED);
      return GNUNET_SYSERR;
    }
  env = GNUNET_MQ_msg(msg, GNUNET_MESSAGE_TYPE_ARM_MONITOR);
  GNUNET_MQ_send(h->mq, env);
  return GNUNET_OK;
}


struct GNUNET_ARM_MonitorHandle *
GNUNET_ARM_monitor_start(const struct GNUNET_CONFIGURATION_Handle *cfg,
                         GNUNET_ARM_ServiceStatusCallback cont,
                         void *cont_cls)
{
  struct GNUNET_ARM_MonitorHandle *h;

  h = GNUNET_new(struct GNUNET_ARM_MonitorHandle);
  h->cfg = cfg;
  h->service_status = cont;
  h->service_status_cls = cont_cls;
  if (GNUNET_OK != reconnect_arm_monitor(h))
    {
      GNUNET_free(h);
      return NULL;
    }
  return h;
}


void
GNUNET_ARM_monitor_stop(struct GNUNET_ARM_MonitorHandle *h)
{
  if (NULL != h->mq)
    {
      GNUNET_MQ_destroy(h->mq);
      h->mq = NULL;
    }
  if (NULL != h->reconnect_task)
    {
      GNUNET_SCHEDULER_cancel(h->reconnect_task);
      h->reconnect_task = NULL;
    }
  GNUNET_free(h);
}


/* end of arm_api.c */