[GNUnet-SVN] r26403 - gnunet/src/arm

[gnunet]

Author: LRN
Date: 2013-03-13 19:03:58 +0100 (Wed, 13 Mar 2013)
New Revision: 26403

Added:
   gnunet/src/arm/arm_monitor_api.c
Log:
Forgot to add the file...

Added: gnunet/src/arm/arm_monitor_api.c
===================================================================
--- gnunet/src/arm/arm_monitor_api.c                            (rev 0)
+++ gnunet/src/arm/arm_monitor_api.c    2013-03-13 18:03:58 UTC (rev 26403)
@@ -0,0 +1,367 @@
+/*
+     This file is part of GNUnet.
+     (C) 2009, 2010, 2012, 2013 Christian Grothoff (and other contributing 
authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 3, 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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file arm/arm_monitor_api.c
+ * @brief API for monitoring the ARM service
+ * @author Christian Grothoff, LRN
+ */
+#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__)
+
+/**
+ * Handle for interacting with ARM.
+ */
+struct GNUNET_ARM_MonitorHandle
+{
+
+  /**
+   * Our control connection to the ARM service.
+   */
+  struct GNUNET_CLIENT_Connection *monitor;
+
+  /**
+   * The configuration that we are using.
+   */
+  struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Handle for our current transmission request.
+   */
+  struct GNUNET_CLIENT_TransmitHandle *cth;
+
+  /**
+   * ID of the reconnect task (if any).
+   */
+  GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
+
+  /**
+   * Current delay we use for re-trying to connect to core.
+   */
+  struct GNUNET_TIME_Relative retry_backoff;
+
+  /**
+   * Are we currently disconnected and hence unable to send?
+   */
+  unsigned char currently_down;
+
+  /**
+   * Callback to invoke on status updates.
+   */
+  GNUNET_ARM_ServiceStatusCallback service_status;
+
+  /**
+   * Closure for service_status.
+   */
+  void *cls;
+
+  /**
+   * ID of a task to run if we fail to get a reply to the init message in time.
+   */
+  GNUNET_SCHEDULER_TaskIdentifier init_timeout_task_id;
+};
+
+static void
+monitor_notify_handler (void *cls, const struct GNUNET_MessageHeader *msg);
+
+static void
+reconnect_arm_monitor (struct GNUNET_ARM_MonitorHandle *h);
+
+/**
+ * Task scheduled to try to re-connect to arm.
+ *
+ * @param cls the 'struct GNUNET_ARM_MonitorHandle'
+ * @param tc task context
+ */
+static void
+reconnect_arm_monitor_task (void *cls, const struct 
GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct GNUNET_ARM_MonitorHandle *h = cls;
+
+  h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Connecting to ARM service for monitoring 
after delay\n");
+  reconnect_arm_monitor (h);
+}
+
+
+/**
+ * Close down any existing connection to the ARM service and
+ * try re-establishing it later.
+ *
+ * @param h our handle
+ */
+static void
+reconnect_arm_monitor_later (struct GNUNET_ARM_MonitorHandle *h)
+{
+  if (NULL != h->cth)
+  {
+    GNUNET_CLIENT_notify_transmit_ready_cancel (h->cth);
+    h->cth = NULL;
+  }
+
+  if (NULL != h->monitor)
+  {
+    GNUNET_CLIENT_disconnect (h->monitor);
+    h->monitor = NULL;
+  }
+
+  if (GNUNET_SCHEDULER_NO_TASK != h->init_timeout_task_id)
+  {
+    GNUNET_SCHEDULER_cancel (h->init_timeout_task_id);
+    h->init_timeout_task_id = GNUNET_SCHEDULER_NO_TASK;
+  }
+
+  GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == 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);
+}
+
+
+/**
+ * Init message timed out. Disconnect and try again.
+ *
+ * @param cls arm monitor handle
+ * @param tc task context
+ */
+static void
+init_timeout_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct GNUNET_ARM_MonitorHandle *h = cls;
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Init message timed out\n");
+
+  reconnect_arm_monitor_later (h);
+}
+
+
+/**
+ * Transmit the monitoring initialization message to the arm service.
+ *
+ * @param cls closure with the 'struct GNUNET_ARM_MonitorHandle'
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf 
+ */
+static size_t
+transmit_monitoring_init_message (void *cls, size_t size, void *buf)
+{
+  struct GNUNET_ARM_MonitorHandle *h = cls;
+  struct GNUNET_MessageHeader *msg;
+  uint16_t msize;
+
+  GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == h->reconnect_task);
+  GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == h->init_timeout_task_id);
+  h->cth = NULL;
+  if (NULL == buf)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Transmission failed, initiating reconnect\n");
+    reconnect_arm_monitor_later (h);
+    return 0;
+  }
+  msize = sizeof (struct GNUNET_MessageHeader);
+  if (size < msize)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+        "Request is too big (%u < %u), not sending it\n", size, msize);
+    h->cth = GNUNET_CLIENT_notify_transmit_ready (h->monitor, msize,
+        GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO,
+        transmit_monitoring_init_message, h);
+    return 0;
+  }
+
+  msg = buf;
+  msg->size = htons (msize);
+  msg->type = htons (GNUNET_MESSAGE_TYPE_ARM_MONITOR);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Transmitting ARM monitoring init message with %u bytes to arm.\n",
+       (unsigned int) msize);
+
+  h->init_timeout_task_id = GNUNET_SCHEDULER_add_delayed (
+      INIT_TIMEOUT, init_timeout_task, h);
+  GNUNET_CLIENT_receive (h->monitor, &monitor_notify_handler, h,
+                         GNUNET_TIME_UNIT_FOREVER_REL);
+  return msize;
+}
+
+
+static void
+reconnect_arm_monitor (struct GNUNET_ARM_MonitorHandle *h)
+{
+  GNUNET_assert (NULL == h->monitor);
+  h->monitor = GNUNET_CLIENT_connect ("arm", h->cfg);
+  if (NULL == h->monitor)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+          "arm_api, GNUNET_CLIENT_connect returned NULL\n");
+    GNUNET_CLIENT_disconnect (h->monitor);
+    h->monitor = NULL;
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+        "arm_api, GNUNET_CLIENT_connect returned non-NULL\n");
+  h->cth = GNUNET_CLIENT_notify_transmit_ready (h->monitor,
+      sizeof (struct GNUNET_MessageHeader), GNUNET_TIME_UNIT_FOREVER_REL,
+      GNUNET_NO, &transmit_monitoring_init_message, h);
+}
+
+
+/**
+ * Setup a context for monitoring ARM.  Note that this
+ * can be done even if the ARM service is not yet running.
+ * Never fails.
+ *
+ * @param cfg configuration to use (needed to contact ARM;
+ *        the ARM service may internally use a different
+ *        configuration to determine how to start the service).
+ * @return context to use for further ARM monitoring operations
+ */
+struct GNUNET_ARM_MonitorHandle *
+GNUNET_ARM_monitor_alloc (const struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+  struct GNUNET_ARM_MonitorHandle *ret;
+
+  ret = GNUNET_malloc (sizeof (struct GNUNET_ARM_MonitorHandle));
+  ret->cfg = GNUNET_CONFIGURATION_dup (cfg);
+  ret->currently_down = GNUNET_YES;
+  ret->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
+  ret->init_timeout_task_id = GNUNET_SCHEDULER_NO_TASK;
+  return ret;
+}
+
+
+/**
+ * Start connecting to the ARM service for monitoring using the context.
+ *
+ * @param h ARM monitor handle
+ * @param cont callback to invoke on status updates
+ * @param cont_cls closure
+ */
+void
+GNUNET_ARM_monitor (struct GNUNET_ARM_MonitorHandle *h,
+    GNUNET_ARM_ServiceStatusCallback cont, void *cont_cls)
+{
+  h->service_status = cont;
+  h->cls = cont_cls;
+  reconnect_arm_monitor (h);
+}
+
+
+/**
+ * Disconnect from the ARM service (if connected) and destroy the context.
+ * Don't call inside a callback!
+ *
+ * @param h the handle that was being used
+ */
+void
+GNUNET_ARM_monitor_disconnect (struct GNUNET_ARM_MonitorHandle *handle)
+{
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting from ARM service\n");
+  if (NULL != handle->cth)
+  {
+    GNUNET_CLIENT_notify_transmit_ready_cancel (handle->cth);
+    handle->cth = NULL;
+  }
+  if (GNUNET_SCHEDULER_NO_TASK != handle->init_timeout_task_id)
+  {
+    GNUNET_SCHEDULER_cancel (handle->init_timeout_task_id);
+    handle->init_timeout_task_id = GNUNET_SCHEDULER_NO_TASK;
+  }
+  if (NULL != handle->monitor)
+  {
+    GNUNET_CLIENT_disconnect (handle->monitor);
+    handle->monitor = NULL;
+  }
+  if (GNUNET_SCHEDULER_NO_TASK != handle->reconnect_task)
+  {
+    GNUNET_SCHEDULER_cancel (handle->reconnect_task);
+    handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
+  }
+  GNUNET_CONFIGURATION_destroy (handle->cfg);
+  GNUNET_free (handle);
+}
+
+
+/**
+ * Handler for notification messages received from ARM.
+ *
+ * @param cls our "struct GNUNET_ARM_MonitorHandle"
+ * @param msg the message received from the arm service
+ */
+static void
+monitor_notify_handler (void *cls, const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_ARM_MonitorHandle *h = cls;
+  uint16_t msize;
+  const struct GNUNET_ARM_StatusMessage *res;
+  enum GNUNET_ARM_ServiceStatus status;
+
+  if (NULL == msg)
+  {
+    LOG (GNUNET_ERROR_TYPE_INFO,
+         _("Monitoring client was disconnected from arm service, trying to 
reconnect.\n"));
+    reconnect_arm_monitor_later (h);
+    return;
+  }
+  msize = ntohs (msg->size);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Processing message of type %u and size %u from arm service\n",
+       ntohs (msg->type), msize);
+  switch (ntohs (msg->type))
+  {
+  case GNUNET_MESSAGE_TYPE_ARM_STATUS:
+    if (msize <= sizeof (struct GNUNET_ARM_StatusMessage))
+    {
+      GNUNET_break (0);
+      reconnect_arm_monitor_later (h);
+      return;
+    }
+    if (GNUNET_SCHEDULER_NO_TASK != h->init_timeout_task_id)
+    {
+      GNUNET_SCHEDULER_cancel (h->init_timeout_task_id);
+      h->init_timeout_task_id = GNUNET_SCHEDULER_NO_TASK;
+    }
+    res = (const struct GNUNET_ARM_StatusMessage *) msg;
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Received response from ARM for service `%s': %u\n",
+         (const char *) &res[1], ntohs (msg->type));
+    status = (enum GNUNET_ARM_ServiceStatus) ntohl (res->status);
+    if ((NULL != h->service_status))
+      h->service_status (h->cls, h, (const char *) &res[1], status);
+    break;
+  default:
+    reconnect_arm_monitor_later (h);
+    return;
+  }
+  GNUNET_CLIENT_receive (h->monitor, &monitor_notify_handler, h,
+      GNUNET_TIME_UNIT_FOREVER_REL);
+}
+
+
+/* end of arm_api.c */