-skeleton for identity service

1 files changed, 239 insertions, 0 deletions

diff --git a/src/identity/identity_api.c b/src/identity/identity_api.c
new file mode 100644
index 000000000..091a1d60c
--- /dev/null
+++ b/src/identity/identity_api.c
@@ -0,0 +1,239 @@
+/*
+     This file is part of GNUnet.
+     (C) 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 Liceidentity 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 Liceidentity for more details.
+
+     You should have received a copy of the GNU General Public Liceidentity
+     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 identity/identity_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_identity_service.h"
+#include "identity.h"
+
+#define LOG(kind,...) GNUNET_log_from (kind, "identity-api",__VA_ARGS__)
+
+/**
+ * Handle for the service.
+ */
+struct GNUNET_IDENTITY_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;
+
+};
+
+
+/**
+ * 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_IDENTITY_Handle *h = cls;
+  const struct GNUNET_IDENTITY_ClientMessage *client_msg;
+
+  if (msg == NULL)
+  {
+    /* Error, timeout, death */
+    GNUNET_CLIENT_disconnect (h->client);
+    h->client = NULL;
+    h->reconnect_task =
+        GNUNET_SCHEDULER_add_delayed (h->reconnect_delay, &reconnect, h);
+    return;
+  }
+  // FIXME: process...
+  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_IDENTITY_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);
+    h->client = NULL;
+  }
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Scheduling task to reconnect to identity service in %llu ms.\n",
+       h->reconnect_delay.rel_value);
+  h->reconnect_task =
+      GNUNET_SCHEDULER_add_delayed (h->reconnect_delay, &reconnect, h);
+  h->reconnect_delay = GNUNET_TIME_STD_BACKOFF (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)
+{
+  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_IDENTITY_Handle *h = cls;
+
+  h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
+  if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
+  {
+    /* shutdown, just give up */
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Connecting to network size estimation service.\n");
+  GNUNET_assert (h->client == NULL);
+  h->client = GNUNET_CLIENT_connect ("identity", 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 identity service.
+ *
+ * @param cfg the configuration to use
+ * @param cb function to call on all identity events, can be NULL
+ * @param cb_cls closure for 'cb'
+ * @return handle to use
+ */
+struct GNUNET_IDENTITY_Handle *
+GNUNET_IDENTITY_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                         GNUNET_IDENTITY_Callback cb,
+                         void *cb_cls)
+{
+  struct GNUNET_IDENTITY_Handle *ret;
+
+  ret = GNUNET_malloc (sizeof (struct GNUNET_IDENTITY_Handle));
+  ret->cfg = cfg;
+  ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
+  ret->reconnect_task = GNUNET_SCHEDULER_add_now (&reconnect, ret);
+  return ret;
+}
+
+
+/**
+ * Disconnect from identity service
+ *
+ * @param h handle to destroy
+ */
+void
+GNUNET_IDENTITY_disconnect (struct GNUNET_IDENTITY_Handle *h)
+{
+  GNUNET_assert (NULL != h);
+  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);
+    h->client = NULL;
+  }
+  GNUNET_free (h);
+}
+
+/* end of identity_api.c */