1 files changed, 238 insertions, 0 deletions

diff --git a/src/service/cadet/cadet_api_list_peers.c b/src/service/cadet/cadet_api_list_peers.c
new file mode 100644
index 000000000..52f59cc74
--- /dev/null
+++ b/src/service/cadet/cadet_api_list_peers.c
@@ -0,0 +1,238 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2011, 2017, 2019 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
+ */
+/**
+ * @file cadet/cadet_api_list_peers.c
+ * @brief cadet api: client implementation of cadet service
+ * @author Bartlomiej Polot
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_constants.h"
+#include "gnunet_cadet_service.h"
+#include "cadet.h"
+#include "cadet_protocol.h"
+
+
+/**
+ * Operation handle.
+ */
+struct GNUNET_CADET_PeersLister
+{
+  /**
+   * Monitor callback
+   */
+  GNUNET_CADET_PeersCB peers_cb;
+
+  /**
+   * Info callback closure for @c info_cb.
+   */
+  void *peers_cb_cls;
+
+  /**
+   * Message queue to talk to CADET service.
+   */
+  struct GNUNET_MQ_Handle *mq;
+
+  /**
+   * Configuration we use.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Task to reconnect.
+   */
+  struct GNUNET_SCHEDULER_Task *reconnect_task;
+
+  /**
+   * Backoff for reconnect attempts.
+   */
+  struct GNUNET_TIME_Relative backoff;
+};
+
+
+/**
+ * Process a local reply about info on all tunnels, pass info to the user.
+ *
+ * @param cls a `struct GNUNET_CADET_PeersLister`
+ * @param info Message itself.
+ */
+static void
+handle_get_peers (void *cls,
+                  const struct GNUNET_CADET_LocalInfoPeers *info)
+{
+  struct GNUNET_CADET_PeersLister *pl = cls;
+  struct GNUNET_CADET_PeerListEntry ple;
+
+  ple.peer = info->destination;
+  ple.have_tunnel = (int) ntohs (info->tunnel);
+  ple.n_paths = (unsigned int) ntohs (info->paths);
+  ple.best_path_length = (unsigned int) ntohl (info->best_path_length);
+  pl->peers_cb (pl->peers_cb_cls,
+                &ple);
+}
+
+
+/**
+ * Process a end of list reply about info on all peers.
+ *
+ * @param cls a `struct GNUNET_CADET_PeersLister`
+ * @param msg Message itself.
+ */
+static void
+handle_get_peers_end (void *cls,
+                      const struct GNUNET_MessageHeader *msg)
+{
+  struct GNUNET_CADET_PeersLister *pl = cls;
+
+  (void) msg;
+
+  pl->peers_cb (pl->peers_cb_cls,
+                NULL);
+  GNUNET_CADET_list_peers_cancel (pl);
+}
+
+
+/**
+ * Reconnect to the service and try again.
+ *
+ * @param cls a `struct GNUNET_CADET_PeersLister` operation
+ */
+static void
+reconnect (void *cls);
+
+
+/**
+ * Function called on connection trouble.  Reconnects.
+ *
+ * @param cls a `struct GNUNET_CADET_PeersLister`
+ * @param error error code from MQ
+ */
+static void
+error_handler (void *cls,
+               enum GNUNET_MQ_Error error)
+{
+  struct GNUNET_CADET_PeersLister *pl = cls;
+
+  GNUNET_MQ_destroy (pl->mq);
+  pl->mq = NULL;
+  pl->backoff = GNUNET_TIME_randomized_backoff (pl->backoff,
+                                                GNUNET_TIME_UNIT_MINUTES);
+  pl->reconnect_task = GNUNET_SCHEDULER_add_delayed (pl->backoff,
+                                                     &reconnect,
+                                                     pl);
+}
+
+
+/**
+ * Reconnect to the service and try again.
+ *
+ * @param cls a `struct GNUNET_CADET_PeersLister` operation
+ */
+static void
+reconnect (void *cls)
+{
+  struct GNUNET_CADET_PeersLister *pl = cls;
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    GNUNET_MQ_hd_fixed_size (get_peers,
+                             GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_PEERS,
+                             struct GNUNET_CADET_LocalInfoPeers,
+                             pl),
+    GNUNET_MQ_hd_fixed_size (get_peers_end,
+                             GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_PEERS_END,
+                             struct GNUNET_MessageHeader,
+                             pl),
+    GNUNET_MQ_handler_end ()
+  };
+  struct GNUNET_MessageHeader *msg;
+  struct GNUNET_MQ_Envelope *env;
+
+  pl->reconnect_task = NULL;
+  pl->mq = GNUNET_CLIENT_connect (pl->cfg,
+                                  "cadet",
+                                  handlers,
+                                  &error_handler,
+                                  pl);
+  if (NULL == pl->mq)
+    return;
+  env = GNUNET_MQ_msg (msg,
+                       GNUNET_MESSAGE_TYPE_CADET_LOCAL_REQUEST_INFO_PEERS);
+  GNUNET_MQ_send (pl->mq,
+                  env);
+}
+
+
+/**
+ * Request information about peers known to the running cadet service.
+ * The callback will be called for every peer known to the service.
+ * Only one info request (of any kind) can be active at once.
+ *
+ * @param cfg configuration to use
+ * @param callback Function to call with the requested data.
+ * @param callback_cls Closure for @c callback.
+ * @return NULL on error
+ */
+struct GNUNET_CADET_PeersLister *
+GNUNET_CADET_list_peers (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                         GNUNET_CADET_PeersCB callback,
+                         void *callback_cls)
+{
+  struct GNUNET_CADET_PeersLister *pl;
+
+  if (NULL == callback)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  pl = GNUNET_new (struct GNUNET_CADET_PeersLister);
+  pl->peers_cb = callback;
+  pl->peers_cb_cls = callback_cls;
+  pl->cfg = cfg;
+  reconnect (pl);
+  if (NULL == pl->mq)
+  {
+    GNUNET_free (pl);
+    return NULL;
+  }
+  return pl;
+}
+
+
+/**
+ * Cancel a peer info request. The callback will not be called (anymore).
+ *
+ * @param pl operation handle
+ * @return Closure given to GNUNET_CADET_get_peers().
+ */
+void *
+GNUNET_CADET_list_peers_cancel (struct GNUNET_CADET_PeersLister *pl)
+{
+  void *ret = pl->peers_cb_cls;
+
+  if (NULL != pl->mq)
+    GNUNET_MQ_destroy (pl->mq);
+  if (NULL != pl->reconnect_task)
+    GNUNET_SCHEDULER_cancel (pl->reconnect_task);
+  GNUNET_free (pl);
+  return ret;
+}
+
+
+/* end of cadet_api_list_peers.c */