implementing new TRANSPORT_hello_get API

3 files changed, 280 insertions, 4 deletions

diff --git a/src/include/gnunet_transport_hello_service.h b/src/include/gnunet_transport_hello_service.h
index 8fc558d3f4..8573613acb 100644
--- a/src/include/gnunet_transport_hello_service.h
+++ b/src/include/gnunet_transport_hello_service.h
@@ -66,7 +66,7 @@ typedef void
 /**
  * Handle to cancel a #GNUNET_TRANSPORT_hello_get() operation.
  */
-struct GNUNET_TRANSPORT_GetHelloHandle;
+struct GNUNET_TRANSPORT_HelloGetHandle;
 
 
 /**
@@ -79,8 +79,8 @@ struct GNUNET_TRANSPORT_GetHelloHandle;
  * @param rec_cls closure for @a rec
  * @return handle to cancel the operation
  */
-struct GNUNET_TRANSPORT_GetHelloHandle *
-GNUNET_TRANSPORT_hello_get (struct GNUNET_CONFIGURATION_Handle *cfg,
+struct GNUNET_TRANSPORT_HelloGetHandle *
+GNUNET_TRANSPORT_hello_get (const struct GNUNET_CONFIGURATION_Handle *cfg,
                             enum GNUNET_ATS_Network_Type nt,
                             GNUNET_TRANSPORT_HelloUpdateCallback rec,
                             void *rec_cls);
@@ -92,7 +92,7 @@ GNUNET_TRANSPORT_hello_get (struct GNUNET_CONFIGURATION_Handle *cfg,
  * @param ghh handle to cancel
  */
 void
-GNUNET_TRANSPORT_hello_get_cancel (struct GNUNET_TRANSPORT_GetHelloHandle *ghh);
+GNUNET_TRANSPORT_hello_get_cancel (struct GNUNET_TRANSPORT_HelloGetHandle *ghh);
 
 
 /**
diff --git a/src/transport/Makefile.am b/src/transport/Makefile.am
index 5c12f8e547..6ba7d881b6 100644
--- a/src/transport/Makefile.am
+++ b/src/transport/Makefile.am
@@ -171,6 +171,7 @@ libgnunettransport_la_SOURCES = \
   transport_api_blacklist.c \
   transport_api_core.c \
   transport_api_get_hello.c \
+  transport_api_hello_get.c \
   transport_api_manipulation.c \
   transport_api_monitor_peers.c \
   transport_api_monitor_plugins.c \
diff --git a/src/transport/transport_api_hello_get.c b/src/transport/transport_api_hello_get.c
new file mode 100644
index 0000000000..9d4209e048
--- /dev/null
+++ b/src/transport/transport_api_hello_get.c
@@ -0,0 +1,275 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2009-2013, 2016 GNUnet e.V.
+
+     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., 51 Franklin Street, Fifth Floor,
+     Boston, MA 02110-1301, USA.
+*/
+
+/**
+ * @file transport/transport_api_hello_get.c
+ * @brief library to obtain our HELLO from our transport service
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_constants.h"
+#include "gnunet_arm_service.h"
+#include "gnunet_hello_lib.h"
+#include "gnunet_protocols.h"
+#include "gnunet_transport_hello_service.h"
+#include "transport.h"
+
+
+/**
+ * Functions to call with this peer's HELLO.
+ */
+struct GNUNET_TRANSPORT_HelloGetHandle
+{
+
+  /**
+   * Our configuration.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Transport handle.
+   */
+  struct GNUNET_MQ_Handle *mq;
+
+  /**
+   * Callback to call once we got our HELLO.
+   */
+  GNUNET_TRANSPORT_HelloUpdateCallback rec;
+
+  /**
+   * Closure for @e rec.
+   */
+  void *rec_cls;
+
+  /**
+   * Task for calling the HelloUpdateCallback when we already have a HELLO
+   */
+  struct GNUNET_SCHEDULER_Task *notify_task;
+
+  /**
+   * ID of the task trying to reconnect to the service.
+   */
+  struct GNUNET_SCHEDULER_Task *reconnect_task;
+
+  /**
+   * Delay until we try to reconnect.
+   */
+  struct GNUNET_TIME_Relative reconnect_delay;
+
+  /**
+   * Type of HELLOs client cares about.
+   */
+  enum GNUNET_ATS_Network_Type nt;
+};
+
+
+/**
+ * Function we use for checking incoming HELLO messages.
+ *
+ * @param cls closure, a `struct GNUNET_TRANSPORT_Handle *`
+ * @param msg message received
+ * @return #GNUNET_OK if message is well-formed
+ */
+static int
+check_hello (void *cls,
+             const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_PeerIdentity me;
+
+  if (GNUNET_OK !=
+      GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg,
+                           &me))
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Receiving (my own) HELLO message (%u bytes), I am `%s'.\n",
+              (unsigned int) ntohs (msg->size),
+              GNUNET_i2s (&me));
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function we use for handling incoming HELLO messages.
+ *
+ * @param cls closure, a `struct GNUNET_TRANSPORT_HelloGetHandle *`
+ * @param msg message received
+ */
+static void
+handle_hello (void *cls,
+              const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_TRANSPORT_HelloGetHandle *ghh = cls;
+
+  ghh->rec (ghh->rec_cls,
+            msg);
+}
+
+
+/**
+ * Function that will schedule the job that will try
+ * to connect us again to the client.
+ *
+ * @param ghh transport service to reconnect
+ */
+static void
+schedule_reconnect (struct GNUNET_TRANSPORT_HelloGetHandle *ghh);
+
+
+/**
+ * Generic error handler, called with the appropriate
+ * error code and the same closure specified at the creation of
+ * the message queue.
+ * Not every message queue implementation supports an error handler.
+ *
+ * @param cls closure with the `struct GNUNET_TRANSPORT_Handle *`
+ * @param error error code
+ */
+static void
+mq_error_handler (void *cls,
+                  enum GNUNET_MQ_Error error)
+{
+  struct GNUNET_TRANSPORT_HelloGetHandle *ghh = cls;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Error receiving from transport service, disconnecting temporarily.\n");
+  GNUNET_MQ_destroy (ghh->mq);
+  ghh->mq = NULL;
+  schedule_reconnect (ghh);
+}
+
+
+/**
+ * Try again to connect to transport service.
+ *
+ * @param cls the handle to the transport service
+ */
+static void
+reconnect (void *cls)
+{
+  GNUNET_MQ_hd_var_size (hello,
+                         GNUNET_MESSAGE_TYPE_HELLO,
+                         struct GNUNET_MessageHeader);
+  struct GNUNET_TRANSPORT_HelloGetHandle *ghh = cls;
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    make_hello_handler (ghh),
+    GNUNET_MQ_handler_end ()
+  };
+  struct GNUNET_MQ_Envelope *env;
+  struct StartMessage *s;
+
+  ghh->reconnect_task = NULL;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Connecting to transport service.\n");
+  GNUNET_assert (NULL == ghh->mq);
+  ghh->mq = GNUNET_CLIENT_connecT (ghh->cfg,
+                                   "transport",
+                                   handlers,
+                                   &mq_error_handler,
+                                   ghh);
+  if (NULL == ghh->mq)
+    return;
+  env = GNUNET_MQ_msg (s,
+                       GNUNET_MESSAGE_TYPE_TRANSPORT_START);
+  s->options = htonl (0);
+  GNUNET_MQ_send (ghh->mq,
+                  env);
+}
+
+
+/**
+ * Function that will schedule the job that will try
+ * to connect us again to the client.
+ *
+ * @param ghh transport service to reconnect
+ */
+static void
+schedule_reconnect (struct GNUNET_TRANSPORT_HelloGetHandle *ghh)
+{
+  ghh->reconnect_task =
+      GNUNET_SCHEDULER_add_delayed (ghh->reconnect_delay,
+                                    &reconnect,
+                                    ghh);
+  ghh->reconnect_delay = GNUNET_TIME_STD_BACKOFF (ghh->reconnect_delay);
+}
+
+
+/**
+ * Obtain the HELLO message for this peer.  The callback given in this function
+ * is never called synchronously.
+ *
+ * @param cfg configuration
+ * @param nt which network type should the addresses from the HELLO belong to?
+ * @param rec function to call with the HELLO, sender will be our peer
+ *            identity; message and sender will be NULL on timeout
+ *            (handshake with transport service pending/failed).
+ *             cost estimate will be 0.
+ * @param rec_cls closure for @a rec
+ * @return handle to cancel the operation
+ */
+struct GNUNET_TRANSPORT_HelloGetHandle *
+GNUNET_TRANSPORT_hello_get (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                            enum GNUNET_ATS_Network_Type nt,
+                            GNUNET_TRANSPORT_HelloUpdateCallback rec,
+                            void *rec_cls)
+{
+  struct GNUNET_TRANSPORT_HelloGetHandle *ghh;
+
+  ghh = GNUNET_new (struct GNUNET_TRANSPORT_HelloGetHandle);
+  ghh->rec = rec;
+  ghh->rec_cls = rec_cls;
+  ghh->cfg = cfg;
+  ghh->nt = nt;
+  reconnect (ghh);
+  if (NULL == ghh->mq)
+  {
+    GNUNET_free (ghh);
+    return NULL;
+  }
+  return ghh;
+}
+
+
+/**
+ * Stop receiving updates about changes to our HELLO message.
+ *
+ * @param ghh handle to cancel
+ */
+void
+GNUNET_TRANSPORT_hello_get_cancel (struct GNUNET_TRANSPORT_HelloGetHandle *ghh)
+{
+  if (NULL != ghh->reconnect_task)
+  {
+    GNUNET_SCHEDULER_cancel (ghh->reconnect_task);
+    ghh->reconnect_task = NULL;
+  }
+  if (NULL != ghh->mq)
+  {
+    GNUNET_MQ_destroy (ghh->mq);
+    ghh->mq = NULL;
+  }
+  GNUNET_free (ghh);
+}
+
+
+/* end of transport_api_hello_get.c */