1 files changed, 277 insertions, 0 deletions

diff --git a/src/cadet/cadet_api_get_path.c b/src/cadet/cadet_api_get_path.c
new file mode 100644
index 000000000..2f35e365e
--- /dev/null
+++ b/src/cadet/cadet_api_get_path.c
@@ -0,0 +1,277 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2011, 2017 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_get_path.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_GetPath
+{
+
+  /**
+   * Monitor callback
+   */
+  GNUNET_CADET_PathCB path_cb;
+
+  /**
+   * Closure for @c path_cb.
+   */
+  void *path_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;
+  
+  /**
+   * Peer we want information about.
+   */
+  struct GNUNET_PeerIdentity id;
+
+};
+
+
+/**
+ * Check that message received from CADET service is well-formed.
+ *
+ * @param cls unused
+ * @param message the message we got
+ * @return #GNUNET_OK if the message is well-formed,
+ *         #GNUNET_SYSERR otherwise
+ */
+static int
+check_get_path (void *cls,
+                const struct GNUNET_CADET_LocalInfoPath *message)
+{
+  size_t msize = sizeof (struct GNUNET_CADET_LocalInfoPath);
+  size_t esize;
+
+  (void) cls;
+  esize = ntohs (message->header.size);
+  if (esize < msize)
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  if (0 != ((esize - msize) % sizeof (struct GNUNET_PeerIdentity)))
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Process a local peer info reply, pass info to the user.
+ *
+ * @param cls Closure 
+ * @param message Message itself.
+ */
+static void
+handle_get_path (void *cls,
+                 const struct GNUNET_CADET_LocalInfoPath *message)
+{
+  struct GNUNET_CADET_GetPath *gp = cls;
+  struct GNUNET_CADET_PeerPathDetail ppd;
+  
+  ppd.peer = gp->id;
+  ppd.path = (const struct GNUNET_PeerIdentity *) &message[1];
+  ppd.path_length = (ntohs (message->header.size) - sizeof (*message))
+    / sizeof (struct GNUNET_PeerIdentity);
+  gp->path_cb (gp->path_cb_cls,
+               &ppd);
+}
+
+
+/**
+ * Process a local peer info reply, pass info to the user.
+ *
+ * @param cls Closure 
+ * @param message Message itself.
+ */
+static void
+handle_get_path_end (void *cls,
+                     const struct GNUNET_MessageHeader *message)
+{
+  struct GNUNET_CADET_GetPath *gp = cls;
+
+  (void) message;
+  gp->path_cb (gp->path_cb_cls,
+               NULL);
+  GNUNET_CADET_get_path_cancel (gp);
+}
+
+
+/**
+ * Reconnect to the service and try again.
+ *
+ * @param cls a `struct GNUNET_CADET_GetPath` operation
+ */
+static void
+reconnect (void *cls);
+
+
+/**
+ * Function called on connection trouble.  Reconnects.
+ *
+ * @param cls a `struct GNUNET_CADET_GetPath`
+ * @param error error code from MQ
+ */
+static void
+error_handler (void *cls,
+               enum GNUNET_MQ_Error error)
+{
+  struct GNUNET_CADET_GetPath *gp = cls;
+
+  GNUNET_MQ_destroy (gp->mq);
+  gp->mq = NULL;
+  gp->backoff = GNUNET_TIME_randomized_backoff (gp->backoff,
+                                                GNUNET_TIME_UNIT_MINUTES);
+  gp->reconnect_task = GNUNET_SCHEDULER_add_delayed (gp->backoff,
+                                                     &reconnect,
+                                                     gp);
+}
+
+  
+/**
+ * Reconnect to the service and try again.
+ *
+ * @param cls a `struct GNUNET_CADET_GetPath` operation
+ */
+static void
+reconnect (void *cls)
+{
+  struct GNUNET_CADET_GetPath *gp = cls;
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    GNUNET_MQ_hd_var_size (get_path,
+                           GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_PATH,
+                           struct GNUNET_CADET_LocalInfoPath,
+                           gp),
+    GNUNET_MQ_hd_fixed_size (get_path_end,
+                             GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_PATH_END,
+                             struct GNUNET_MessageHeader,
+                             gp),
+    GNUNET_MQ_handler_end ()
+  };
+  struct GNUNET_CADET_RequestPathInfoMessage *msg;
+  struct GNUNET_MQ_Envelope *env;
+
+  gp->reconnect_task = NULL;
+  gp->mq = GNUNET_CLIENT_connect (gp->cfg,
+                                  "cadet",
+                                  handlers,
+                                  &error_handler,
+                                  gp);
+  if (NULL == gp->mq)
+    return;
+  env = GNUNET_MQ_msg (msg,
+                       GNUNET_MESSAGE_TYPE_CADET_LOCAL_REQUEST_INFO_PATH);
+  msg->peer = gp->id;
+  GNUNET_MQ_send (gp->mq,
+                  env);
+}
+
+
+/**
+ * Request information about paths known to the running cadet peer.
+ *
+ * @param cfg configuration to use
+ * @param id Peer whose paths to examine.
+ * @param callback Function to call with the requested data.
+ * @param callback_cls Closure for @c callback.
+ * @return NULL on error
+ */
+struct GNUNET_CADET_GetPath *
+GNUNET_CADET_get_path (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                       const struct GNUNET_PeerIdentity *id,
+                       GNUNET_CADET_PathCB callback,
+                       void *callback_cls)
+{
+  struct GNUNET_CADET_GetPath *gp;
+
+  if (NULL == callback)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  gp = GNUNET_new (struct GNUNET_CADET_GetPath);
+  gp->path_cb = callback;
+  gp->path_cb_cls = callback_cls;
+  gp->cfg = cfg;
+  gp->id = *id;
+  reconnect (gp);
+  if (NULL == gp->mq)
+  {
+    GNUNET_free (gp);
+    return NULL;
+  }
+  return gp;
+}
+
+
+/**
+ * Cancel @a gp operation.
+ *
+ * @param gp operation to cancel
+ * @return closure from #GNUNET_CADET_get_path().
+ */
+void *
+GNUNET_CADET_get_path_cancel (struct GNUNET_CADET_GetPath *gp)
+{
+  void *ret = gp->path_cb_cls;
+
+  if (NULL != gp->mq)
+    GNUNET_MQ_destroy (gp->mq);
+  if (NULL != gp->reconnect_task)
+    GNUNET_SCHEDULER_cancel (gp->reconnect_task);
+  GNUNET_free (gp);
+  return ret;
+}
+
+
+/* end of cadet_api_get_path.c */