Imported Upstream version 0.9.2upstream/0.9.2

1 files changed, 298 insertions, 0 deletions

diff --git a/src/nse/nse_api.c b/src/nse/nse_api.c
new file mode 100644
index 0000000..4d5f6bb
--- /dev/null
+++ b/src/nse/nse_api.c
@@ -0,0 +1,298 @@
+/*
+     This file is part of GNUnet.
+     (C) 2009, 2010, 2011 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 nse/nse_api.c
+ * @brief api to get information from the network size estimation service
+ * @author Nathan Evans
+ */
+#include "platform.h"
+#include "gnunet_client_lib.h"
+#include "gnunet_constants.h"
+#include "gnunet_container_lib.h"
+#include "gnunet_arm_service.h"
+#include "gnunet_hello_lib.h"
+#include "gnunet_protocols.h"
+#include "gnunet_server_lib.h"
+#include "gnunet_time_lib.h"
+#include "gnunet_nse_service.h"
+#include "nse.h"
+
+#define LOG(kind,...) GNUNET_log_from (kind, "nse-api",__VA_ARGS__)
+
+/**
+ * Handle for the service.
+ */
+struct GNUNET_NSE_Handle
+{
+  /**
+   * Configuration to use.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Socket (if available).
+   */
+  struct GNUNET_CLIENT_Connection *client;
+
+  /**
+   * Currently pending transmission request.
+   */
+  struct GNUNET_CLIENT_TransmitHandle *th;
+
+  /**
+   * Task doing exponential back-off trying to reconnect.
+   */
+  GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
+
+  /**
+   * Time for next connect retry.
+   */
+  struct GNUNET_TIME_Relative reconnect_delay;
+
+  /**
+   * Callback function to call when message is received.
+   */
+  GNUNET_NSE_Callback recv_cb;
+
+  /**
+   * Closure to pass to callback.
+   */
+  void *recv_cb_cls;
+
+};
+
+
+/**
+ * Try again to connect to network size estimation service.
+ *
+ * @param cls the handle to the transport service
+ * @param tc scheduler context
+ */
+static void
+reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
+
+
+/**
+ * Type of a function to call when we receive a message
+ * from the service.
+ *
+ * @param cls closure
+ * @param msg message received, NULL on timeout or fatal error
+ */
+static void
+message_handler (void *cls, const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_NSE_Handle *h = cls;
+  const struct GNUNET_NSE_ClientMessage *client_msg;
+
+  if (msg == NULL)
+  {
+    /* Error, timeout, death */
+    GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
+    h->client = NULL;
+    h->reconnect_task =
+        GNUNET_SCHEDULER_add_delayed (h->reconnect_delay, &reconnect, h);
+    return;
+  }
+  if ((ntohs (msg->size) != sizeof (struct GNUNET_NSE_ClientMessage)) ||
+      (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_NSE_ESTIMATE))
+  {
+    GNUNET_break (0);
+    return;
+  }
+  client_msg = (const struct GNUNET_NSE_ClientMessage *) msg;
+  h->recv_cb (h->recv_cb_cls, GNUNET_TIME_absolute_ntoh (client_msg->timestamp),
+              GNUNET_ntoh_double (client_msg->size_estimate), 
+	      GNUNET_ntoh_double (client_msg->std_deviation));
+  GNUNET_CLIENT_receive (h->client, &message_handler, h,
+                         GNUNET_TIME_UNIT_FOREVER_REL);
+}
+
+
+
+/**
+ * Reschedule a connect attempt to the service.
+ *
+ * @param h transport service to reconnect
+ */
+static void
+reschedule_connect (struct GNUNET_NSE_Handle *h)
+{
+  GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
+
+  if (NULL != h->th)
+  {
+    GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
+    h->th = NULL;
+  }
+  if (NULL != h->client)
+  {
+    GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
+    h->client = NULL;
+  }
+
+#if DEBUG_NSE
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Scheduling task to reconnect to nse service in %llu ms.\n",
+       h->reconnect_delay.rel_value);
+#endif
+  h->reconnect_task =
+      GNUNET_SCHEDULER_add_delayed (h->reconnect_delay, &reconnect, h);
+  if (h->reconnect_delay.rel_value == 0)
+  {
+    h->reconnect_delay = GNUNET_TIME_UNIT_MILLISECONDS;
+  }
+  else
+  {
+    h->reconnect_delay = GNUNET_TIME_relative_multiply (h->reconnect_delay, 2);
+    h->reconnect_delay =
+        GNUNET_TIME_relative_min (GNUNET_TIME_UNIT_SECONDS, h->reconnect_delay);
+  }
+}
+
+
+/**
+ * Transmit START message to service.
+ *
+ * @param cls unused
+ * @param size number of bytes available in buf
+ * @param buf where to copy the message
+ * @return number of bytes copied to buf
+ */
+static size_t
+send_start (void *cls, size_t size, void *buf)
+{
+  struct GNUNET_NSE_Handle *h = cls;
+  struct GNUNET_MessageHeader *msg;
+
+  h->th = NULL;
+  if (buf == NULL)
+  {
+    /* Connect error... */
+#if DEBUG_NSE
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Shutdown while trying to transmit `%s' request.\n", "START");
+#endif
+    reschedule_connect (h);
+    return 0;
+  }
+#if DEBUG_NSE
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Transmitting `%s' request.\n", "START");
+#endif
+  GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
+
+  msg = (struct GNUNET_MessageHeader *) buf;
+  msg->size = htons (sizeof (struct GNUNET_MessageHeader));
+  msg->type = htons (GNUNET_MESSAGE_TYPE_NSE_START);
+  GNUNET_CLIENT_receive (h->client, &message_handler, h,
+                         GNUNET_TIME_UNIT_FOREVER_REL);
+  return sizeof (struct GNUNET_MessageHeader);
+}
+
+
+/**
+ * Try again to connect to network size estimation service.
+ *
+ * @param cls the handle to the transport service
+ * @param tc scheduler context
+ */
+static void
+reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct GNUNET_NSE_Handle *h = cls;
+
+  h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
+  if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
+  {
+    /* shutdown, just give up */
+    return;
+  }
+#if DEBUG_NSE
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Connecting to network size estimation service.\n");
+#endif
+  GNUNET_assert (h->client == NULL);
+  h->client = GNUNET_CLIENT_connect ("nse", h->cfg);
+  GNUNET_assert (h->client != NULL);
+
+  h->th =
+      GNUNET_CLIENT_notify_transmit_ready (h->client,
+                                           sizeof (struct GNUNET_MessageHeader),
+                                           GNUNET_TIME_UNIT_FOREVER_REL,
+                                           GNUNET_NO, &send_start, h);
+  GNUNET_assert (h->th != NULL);
+}
+
+
+/**
+ * Connect to the network size estimation service.
+ *
+ * @param cfg the configuration to use
+ * @param func funtion to call with network size estimate
+ * @param func_cls closure to pass for network size estimate callback
+ *
+ * @return handle to use
+ */
+struct GNUNET_NSE_Handle *
+GNUNET_NSE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                    GNUNET_NSE_Callback func, void *func_cls)
+{
+  struct GNUNET_NSE_Handle *ret;
+
+  GNUNET_assert (func != NULL);
+  ret = GNUNET_malloc (sizeof (struct GNUNET_NSE_Handle));
+  ret->cfg = cfg;
+  ret->recv_cb = func;
+  ret->recv_cb_cls = func_cls;
+  ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
+  ret->reconnect_task = GNUNET_SCHEDULER_add_now (&reconnect, ret);
+  return ret;
+}
+
+
+/**
+ * Disconnect from network size estimation service
+ *
+ * @param h handle to destroy
+ */
+void
+GNUNET_NSE_disconnect (struct GNUNET_NSE_Handle *h)
+{
+  GNUNET_assert (h != NULL);
+  if (h->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
+  {
+    GNUNET_SCHEDULER_cancel (h->reconnect_task);
+    h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
+  }
+  if (h->th != NULL)
+  {
+    GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
+    h->th = NULL;
+  }
+  if (h->client != NULL)
+  {
+    GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
+    h->client = NULL;
+  }
+  GNUNET_free (h);
+}
+
+/* end of nse_api.c */