more work on #5385

1 files changed, 278 insertions, 0 deletions

diff --git a/src/cadet/cadet_api_get_tunnel.c b/src/cadet/cadet_api_get_tunnel.c
new file mode 100644
index 000000000..3b489dd82
--- /dev/null
+++ b/src/cadet/cadet_api_get_tunnel.c
@@ -0,0 +1,278 @@
+/*
+     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_tunnel.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_GetTunnel
+{
+
+  /**
+   * Monitor callback
+   */
+  GNUNET_CADET_TunnelCB callback;
+
+  /**
+   * Closure for @e callback.
+   */
+  void *callback_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 the `struct GNUNET_CADET_Handle`
+ * @param msg the message we got
+ * @return #GNUNET_OK if the message is well-formed,
+ *         #GNUNET_SYSERR otherwise
+ */
+static int
+check_get_tunnel (void *cls,
+                  const struct GNUNET_CADET_LocalInfoTunnel *msg)
+{
+  unsigned int ch_n;
+  unsigned int c_n;
+  size_t esize;
+  size_t msize;
+
+  (void) cls;
+  /* Verify message sanity */
+  msize = ntohs (msg->header.size);
+  esize = sizeof (struct GNUNET_CADET_LocalInfoTunnel);
+  if (esize > msize)
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  ch_n = ntohl (msg->channels);
+  c_n = ntohl (msg->connections);
+  esize += ch_n * sizeof (struct GNUNET_CADET_ChannelTunnelNumber);
+  esize += c_n * sizeof (struct GNUNET_CADET_ConnectionTunnelIdentifier);
+  if (msize != esize)
+  {
+    GNUNET_break_op (0);
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "m:%u, e: %u (%u ch, %u conn)\n",
+                (unsigned int) msize,
+                (unsigned int) esize,
+                ch_n,
+                c_n);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Process a local tunnel info reply, pass info to the user.
+ *
+ * @param cls a `struct GNUNET_CADET_GetTunnel *`
+ * @param msg Message itself.
+ */
+static void
+handle_get_tunnel (void *cls,
+                   const struct GNUNET_CADET_LocalInfoTunnel *msg)
+{
+  struct GNUNET_CADET_GetTunnel *gt = cls;
+  unsigned int ch_n;
+  unsigned int c_n;
+  const struct GNUNET_CADET_ConnectionTunnelIdentifier *conns;
+  const struct GNUNET_CADET_ChannelTunnelNumber *chns;
+
+  ch_n = ntohl (msg->channels);
+  c_n = ntohl (msg->connections);
+
+  /* Call Callback with tunnel info. */
+  conns = (const struct GNUNET_CADET_ConnectionTunnelIdentifier *) &msg[1];
+  chns = (const struct GNUNET_CADET_ChannelTunnelNumber *) &conns[c_n];
+  gt->callback (gt->callback_cls,
+                &msg->destination,
+                ch_n,
+                c_n,
+                chns,
+                conns,
+                ntohs (msg->estate),
+                ntohs (msg->cstate));
+}
+
+
+/**
+ * Reconnect to the service and try again.
+ *
+ * @param cls a `struct GNUNET_CADET_GetTunnel` operation
+ */
+static void
+reconnect (void *cls);
+
+
+/**
+ * Function called on connection trouble.  Reconnects.
+ *
+ * @param cls a `struct GNUNET_CADET_GetTunnel`
+ * @param error error code from MQ
+ */
+static void
+error_handler (void *cls,
+               enum GNUNET_MQ_Error error)
+{
+  struct GNUNET_CADET_GetTunnel *gt = cls;
+
+  GNUNET_MQ_destroy (gt->mq);
+  gt->mq = NULL;
+  gt->backoff = GNUNET_TIME_randomized_backoff (gt->backoff,
+                                                GNUNET_TIME_UNIT_MINUTES);
+  gt->reconnect_task = GNUNET_SCHEDULER_add_delayed (gt->backoff,
+                                                     &reconnect,
+                                                     gt);
+}
+
+  
+/**
+ * Reconnect to the service and try again.
+ *
+ * @param cls a `struct GNUNET_CADET_GetTunnel` operation
+ */
+static void
+reconnect (void *cls)
+{
+  struct GNUNET_CADET_GetTunnel *gt = cls;
+  struct GNUNET_MQ_MessageHandler handlers[] = {
+    GNUNET_MQ_hd_var_size (get_tunnel,
+                           GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_TUNNEL,
+                           struct GNUNET_CADET_LocalInfoTunnel,
+                           gt),
+    GNUNET_MQ_handler_end ()
+  };
+  struct GNUNET_MQ_Envelope *env;
+  struct GNUNET_CADET_LocalInfo *msg;
+  
+  gt->reconnect_task = NULL;
+  gt->mq = GNUNET_CLIENT_connect (gt->cfg,
+                                  "cadet",
+                                  handlers,
+                                  &error_handler,
+                                  gt);
+  if (NULL == gt->mq)
+    return;
+  env = GNUNET_MQ_msg (msg,
+                       GNUNET_MESSAGE_TYPE_CADET_LOCAL_INFO_TUNNEL);
+  msg->peer = gt->id;
+  GNUNET_MQ_send (gt->mq,
+                  env);
+}
+
+/**
+ * Request information about a tunnel of the running cadet peer.
+ * The callback will be called for the tunnel once.
+ *
+ * @param cfg configuration to use
+ * @param id Peer whose tunnel 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_GetTunnel *
+GNUNET_CADET_get_tunnel (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                         const struct GNUNET_PeerIdentity *id,
+                         GNUNET_CADET_TunnelCB callback,
+                         void *callback_cls)
+{
+  struct GNUNET_CADET_GetTunnel *gt;
+
+  if (NULL == callback)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  gt = GNUNET_new (struct GNUNET_CADET_GetTunnel);
+  gt->callback = callback;
+  gt->callback_cls = callback_cls;
+  gt->cfg = cfg;
+  gt->id = *id;
+  reconnect (gt);
+  if (NULL == gt->mq)
+  {
+    GNUNET_free (gt);
+    return NULL;
+  }
+  return gt;
+}
+
+
+/**
+ * Cancel a monitor request. The monitor callback will not be called.
+ *
+ * @param lt operation handle
+ * @return Closure given to #GNUNET_CADET_get_tunnel(), if any.
+ */
+void *
+GNUNET_CADET_get_tunnel_cancel (struct GNUNET_CADET_GetTunnel *gt)
+{
+  void *ret = gt->callback_cls;
+
+  if (NULL != gt->mq)
+    GNUNET_MQ_destroy (gt->mq);
+  if (NULL != gt->reconnect_task)
+    GNUNET_SCHEDULER_cancel (gt->reconnect_task);
+  GNUNET_free (gt);
+  return ret;
+}
+
+/* end of cadet_api_get_tunnel.c */