1 files changed, 826 insertions, 0 deletions

diff --git a/src/service/transport/transport_api2_core.c b/src/service/transport/transport_api2_core.c
new file mode 100644
index 000000000..0d2a0ac7f
--- /dev/null
+++ b/src/service/transport/transport_api2_core.c
@@ -0,0 +1,826 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2009-2013, 2016, 2018 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 transport/transport_api_core.c
+ * @brief library to access the transport service for message exchange
+ * @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_core_service.h"
+#include "transport.h"
+
+#define LOG(kind, ...) GNUNET_log_from (kind, "transport-api-core", __VA_ARGS__)
+
+/**
+ * How large to start with for the hashmap of neighbours.
+ */
+#define STARTING_NEIGHBOURS_SIZE 16
+
+/**
+ * Window size. How many messages to the same target do we pass
+ * to TRANSPORT without a SEND_OK in between? Small values limit
+ * thoughput, large values will increase latency.
+ *
+ * FIXME-OPTIMIZE: find out what good values are experimentally,
+ * maybe set adaptively (i.e. to observed available bandwidth).
+ */
+#define SEND_WINDOW_SIZE 4
+
+
+/**
+ * Entry in hash table of all of our current (connected) neighbours.
+ */
+struct Neighbour
+{
+  /**
+   * Identity of this neighbour.
+   */
+  struct GNUNET_PeerIdentity id;
+
+  /**
+   * Overall transport handle.
+   */
+  struct GNUNET_TRANSPORT_CoreHandle *h;
+
+  /**
+   * Active message queue for the peer.
+   */
+  struct GNUNET_MQ_Handle *mq;
+
+  /**
+   * Envelope with the message we are currently transmitting (or NULL).
+   */
+  struct GNUNET_MQ_Envelope *env;
+
+  /**
+   * Closure for @e mq handlers.
+   */
+  void *handlers_cls;
+
+  /**
+   * How many messages can we still send to this peer before we should
+   * throttle?
+   */
+  unsigned int ready_window;
+
+  /**
+   * Used to indicate our status if @e env is non-NULL.  Set to
+   * #GNUNET_YES if we did pass a message to the MQ and are waiting
+   * for the call to #notify_send_done(). Set to #GNUNET_NO if the @e
+   * ready_window is 0 and @e env is waiting for a
+   * #GNUNET_MESSAGE_TYPE_TRANSPORT_RECV_OK?
+   */
+  int16_t awaiting_done;
+
+  /**
+   * Size of the message in @e env.
+   */
+  uint16_t env_size;
+};
+
+
+/**
+ * Handle for the transport service (includes all of the
+ * state for the transport service).
+ */
+struct GNUNET_TRANSPORT_CoreHandle
+{
+  /**
+   * Closure for the callbacks.
+   */
+  void *cls;
+
+  /**
+   * Functions to call for received data (template for
+   * new message queues).
+   */
+  struct GNUNET_MQ_MessageHandler *handlers;
+
+  /**
+   * function to call on connect events
+   */
+  GNUNET_TRANSPORT_NotifyConnect nc_cb;
+
+  /**
+   * function to call on disconnect events
+   */
+  GNUNET_TRANSPORT_NotifyDisconnect nd_cb;
+
+  /**
+   * My client connection to the transport service.
+   */
+  struct GNUNET_MQ_Handle *mq;
+
+  /**
+   * My configuration.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Hash map of the current connected neighbours of this peer.
+   * Maps peer identities to `struct Neighbour` entries.
+   */
+  struct GNUNET_CONTAINER_MultiPeerMap *neighbours;
+
+  /**
+   * Peer identity as assumed by this process, or all zeros.
+   */
+  struct GNUNET_PeerIdentity self;
+
+  /**
+   * 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;
+
+  /**
+   * Should we check that @e self matches what the service thinks?
+   * (if #GNUNET_NO, then @e self is all zeros!).
+   */
+  int check_self;
+};
+
+
+/**
+ * Function that will schedule the job that will try
+ * to connect us again to the client.
+ *
+ * @param h transport service to reconnect
+ */
+static void
+disconnect_and_schedule_reconnect (struct GNUNET_TRANSPORT_CoreHandle *h);
+
+
+/**
+ * Get the neighbour list entry for the given peer
+ *
+ * @param h our context
+ * @param peer peer to look up
+ * @return NULL if no such peer entry exists
+ */
+static struct Neighbour *
+neighbour_find (struct GNUNET_TRANSPORT_CoreHandle *h,
+                const struct GNUNET_PeerIdentity *peer)
+{
+  return GNUNET_CONTAINER_multipeermap_get (h->neighbours, peer);
+}
+
+
+/**
+ * Iterator over hash map entries, for deleting state of a neighbour.
+ *
+ * @param cls the `struct GNUNET_TRANSPORT_CoreHandle *`
+ * @param key peer identity
+ * @param value value in the hash map, the neighbour entry to delete
+ * @return #GNUNET_YES if we should continue to
+ *         iterate,
+ *         #GNUNET_NO if not.
+ */
+static int
+neighbour_delete (void *cls, const struct GNUNET_PeerIdentity *key, void *value)
+{
+  struct GNUNET_TRANSPORT_CoreHandle *handle = cls;
+  struct Neighbour *n = value;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Dropping entry for neighbour `%s'.\n",
+       GNUNET_i2s (key));
+  if (NULL != handle->nd_cb)
+    handle->nd_cb (handle->cls, &n->id, n->handlers_cls);
+  if (NULL != n->env)
+  {
+    GNUNET_MQ_send_cancel (n->env);
+    n->env = NULL;
+  }
+  GNUNET_MQ_destroy (n->mq);
+  GNUNET_assert (NULL == n->mq);
+  GNUNET_assert (
+    GNUNET_YES ==
+    GNUNET_CONTAINER_multipeermap_remove (handle->neighbours, key, n));
+  GNUNET_free (n);
+  return GNUNET_YES;
+}
+
+
+/**
+ * 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_CoreHandle *`
+ * @param error error code
+ */
+static void
+mq_error_handler (void *cls, enum GNUNET_MQ_Error error)
+{
+  struct GNUNET_TRANSPORT_CoreHandle *h = cls;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Error %u received from transport service, disconnecting temporarily.\n",
+       error);
+  disconnect_and_schedule_reconnect (h);
+}
+
+
+/**
+ * A message from the handler's message queue to a neighbour was
+ * transmitted.  Now trigger (possibly delayed) notification of the
+ * neighbour's message queue that we are done and thus ready for
+ * the next message.  Note that the MQ being ready is independent
+ * of the send window, as we may queue many messages and simply
+ * not pass them to TRANSPORT if the send window is insufficient.
+ *
+ * @param cls the `struct Neighbour` where the message was sent
+ */
+static void
+notify_send_done (void *cls)
+{
+  struct Neighbour *n = cls;
+
+  n->awaiting_done = GNUNET_NO;
+  n->env = NULL;
+  if (0 < n->ready_window)
+    GNUNET_MQ_impl_send_continue (n->mq);
+}
+
+
+/**
+ * We have an envelope waiting for transmission at @a n, and
+ * our transmission window is positive. Perform the transmission.
+ *
+ * @param n neighbour to perform transmission for
+ */
+static void
+do_send (struct Neighbour *n)
+{
+  GNUNET_assert (0 < n->ready_window);
+  GNUNET_assert (NULL != n->env);
+  n->ready_window--;
+  n->awaiting_done = GNUNET_YES;
+  GNUNET_MQ_notify_sent (n->env, &notify_send_done, n);
+  GNUNET_MQ_send (n->h->mq, n->env);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Passed message of type %u for neighbour `%s' to TRANSPORT. ready_window %u\n",
+       ntohs (GNUNET_MQ_env_get_msg (n->env)->type),
+       GNUNET_i2s (&n->id),
+       n->ready_window);
+}
+
+
+/**
+ * Implement sending functionality of a message queue.
+ * Called one message at a time. Should send the @a msg
+ * to the transport service and then notify the queue
+ * once we are ready for the next one.
+ *
+ * @param mq the message queue
+ * @param msg the message to send
+ * @param impl_state state of the implementation
+ */
+static void
+mq_send_impl (struct GNUNET_MQ_Handle *mq,
+              const struct GNUNET_MessageHeader *msg,
+              void *impl_state)
+{
+  struct Neighbour *n = impl_state;
+  struct OutboundMessage *obm;
+  uint16_t msize;
+
+  msize = ntohs (msg->size);
+  if (msize >= GNUNET_MAX_MESSAGE_SIZE - sizeof(*obm))
+  {
+    GNUNET_break (0);
+    GNUNET_MQ_impl_send_continue (mq);
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "CORE requested transmission of message of type %u to neighbour `%s'.\n",
+       ntohs (msg->type),
+       GNUNET_i2s (&n->id));
+
+  GNUNET_assert (NULL == n->env);
+  n->env =
+    GNUNET_MQ_msg_nested_mh (obm, GNUNET_MESSAGE_TYPE_TRANSPORT_SEND, msg);
+  n->env_size = ntohs (msg->size);
+  {
+    struct GNUNET_MQ_Envelope *env;
+
+    env = GNUNET_MQ_get_current_envelope (mq);
+    obm->priority = htonl ((uint32_t) GNUNET_MQ_env_get_options (env));
+  }
+  obm->peer = n->id;
+  if (0 == n->ready_window)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Flow control delays transmission to CORE until we see SEND_OK.\n");
+    return;   /* can't send yet, need to wait for SEND_OK */
+  }
+  do_send (n);
+}
+
+
+/**
+ * Handle destruction of a message queue.  Implementations must not
+ * free @a mq, but should take care of @a impl_state.
+ *
+ * @param mq the message queue to destroy
+ * @param impl_state state of the implementation
+ */
+static void
+mq_destroy_impl (struct GNUNET_MQ_Handle *mq, void *impl_state)
+{
+  struct Neighbour *n = impl_state;
+
+  GNUNET_assert (mq == n->mq);
+  n->mq = NULL;
+}
+
+
+/**
+ * Implementation function that cancels the currently sent message.
+ * Should basically undo whatever #mq_send_impl() did.
+ *
+ * @param mq message queue
+ * @param impl_state state specific to the implementation
+ */
+static void
+mq_cancel_impl (struct GNUNET_MQ_Handle *mq, void *impl_state)
+{
+  struct Neighbour *n = impl_state;
+
+  n->ready_window++;
+  if (GNUNET_YES == n->awaiting_done)
+  {
+    GNUNET_MQ_send_cancel (n->env);
+    n->env = NULL;
+    n->awaiting_done = GNUNET_NO;
+  }
+  else
+  {
+    GNUNET_assert (0 == n->ready_window);
+    n->env = NULL;
+  }
+}
+
+
+/**
+ * We had an error processing a message we forwarded from a peer to
+ * the CORE service.  We should just complain about it but otherwise
+ * continue processing.
+ *
+ * @param cls closure
+ * @param error error code
+ */
+static void
+peer_mq_error_handler (void *cls, enum GNUNET_MQ_Error error)
+{
+  struct Neighbour *n = cls;
+
+  if (GNUNET_MQ_ERROR_MALFORMED == error)
+    GNUNET_break_op (0);
+  //TODO Look into bug #7887
+
+  GNUNET_TRANSPORT_core_receive_continue (n->h, &n->id);
+}
+
+
+/**
+ * Function we use for handling incoming connect messages.
+ *
+ * @param cls closure, a `struct GNUNET_TRANSPORT_Handle *`
+ * @param cim message received
+ */
+static void
+handle_connect (void *cls, const struct ConnectInfoMessage *cim)
+{
+  struct GNUNET_TRANSPORT_CoreHandle *h = cls;
+  struct Neighbour *n;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Receiving CONNECT message for `%s'\n",
+       GNUNET_i2s (&cim->id));
+  n = neighbour_find (h, &cim->id);
+  if (NULL != n)
+  {
+    GNUNET_break (0);
+    disconnect_and_schedule_reconnect (h);
+    return;
+  }
+  n = GNUNET_new (struct Neighbour);
+  n->id = cim->id;
+  n->h = h;
+  n->ready_window = SEND_WINDOW_SIZE;
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_CONTAINER_multipeermap_put (
+                   h->neighbours,
+                   &n->id,
+                   n,
+                   GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
+
+  n->mq = GNUNET_MQ_queue_for_callbacks (&mq_send_impl,
+                                         &mq_destroy_impl,
+                                         &mq_cancel_impl,
+                                         n,
+                                         h->handlers,
+                                         &peer_mq_error_handler,
+                                         n);
+  if (NULL != h->nc_cb)
+  {
+    n->handlers_cls = h->nc_cb (h->cls, &n->id, n->mq);
+    GNUNET_MQ_set_handlers_closure (n->mq, n->handlers_cls);
+  }
+}
+
+
+/**
+ * Function we use for handling incoming disconnect messages.
+ *
+ * @param cls closure, a `struct GNUNET_TRANSPORT_CoreHandle *`
+ * @param dim message received
+ */
+static void
+handle_disconnect (void *cls, const struct DisconnectInfoMessage *dim)
+{
+  struct GNUNET_TRANSPORT_CoreHandle *h = cls;
+  struct Neighbour *n;
+
+  GNUNET_break (ntohl (dim->reserved) == 0);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Receiving DISCONNECT message for `%s'.\n",
+       GNUNET_i2s (&dim->peer));
+  n = neighbour_find (h, &dim->peer);
+  if (NULL == n)
+  {
+    GNUNET_break (0);
+    disconnect_and_schedule_reconnect (h);
+    return;
+  }
+  GNUNET_assert (GNUNET_YES == neighbour_delete (h, &dim->peer, n));
+}
+
+
+/**
+ * Function we use for handling incoming send-ok messages.
+ *
+ * @param cls closure, a `struct GNUNET_TRANSPORT_CoreHandle *`
+ * @param okm message received
+ */
+static void
+handle_send_ok (void *cls, const struct SendOkMessage *okm)
+{
+  struct GNUNET_TRANSPORT_CoreHandle *h = cls;
+  struct Neighbour *n;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Receiving SEND_OK message for transmission to %s\n",
+       GNUNET_i2s (&okm->peer));
+
+  n = neighbour_find (h, &okm->peer);
+
+  if (NULL == n)
+  {
+    /* We should never get a 'SEND_OK' for a peer that we are not
+       connected to */
+    GNUNET_break (0);
+    disconnect_and_schedule_reconnect (h);
+    return;
+  }
+
+  if ((GNUNET_NO == n->awaiting_done) &&
+      (NULL != n->env) &&
+      (0 == n->ready_window))
+  {
+    n->ready_window++;
+    do_send (n);
+    return;
+  }
+  else if ((GNUNET_NO == n->awaiting_done) &&
+           (0 == n->ready_window))
+  {
+    n->ready_window++;
+    GNUNET_MQ_impl_send_continue (n->mq);
+    return;
+  }
+  n->ready_window++;
+}
+
+
+/**
+ * Function we use for checking incoming "inbound" messages.
+ *
+ * @param cls closure, a `struct GNUNET_TRANSPORT_CoreHandle *`
+ * @param im message received
+ */
+static int
+check_recv (void *cls, const struct InboundMessage *im)
+{
+  const struct GNUNET_MessageHeader *imm;
+  uint16_t size;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "check_recv\n");
+  size = ntohs (im->header.size) - sizeof(*im);
+  if (size < sizeof(struct GNUNET_MessageHeader))
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  imm = (const struct GNUNET_MessageHeader *) &im[1];
+  if (ntohs (imm->size) != size)
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function we use for handling incoming messages.
+ *
+ * @param cls closure, a `struct GNUNET_TRANSPORT_CoreHandle *`
+ * @param im message received
+ */
+static void
+handle_recv (void *cls, const struct InboundMessage *im)
+{
+  struct GNUNET_TRANSPORT_CoreHandle *h = cls;
+  const struct GNUNET_MessageHeader *imm =
+    (const struct GNUNET_MessageHeader *) &im[1];
+  struct Neighbour *n;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Received message of type %u with %u bytes from `%s'.\n",
+       (unsigned int) ntohs (imm->type),
+       (unsigned int) ntohs (imm->size),
+       GNUNET_i2s (&im->peer));
+  n = neighbour_find (h, &im->peer);
+  if (NULL == n)
+  {
+    GNUNET_break (0);
+    disconnect_and_schedule_reconnect (h);
+    return;
+  }
+  GNUNET_MQ_inject_message (n->mq, imm);
+}
+
+
+/**
+ * Try again to connect to transport service.
+ *
+ * @param cls the handle to the transport service
+ */
+static void
+reconnect (void *cls)
+{
+  struct GNUNET_TRANSPORT_CoreHandle *h = cls;
+  struct GNUNET_MQ_MessageHandler handlers[] =
+  { GNUNET_MQ_hd_fixed_size (connect,
+                             GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT,
+                             struct ConnectInfoMessage,
+                             h),
+    GNUNET_MQ_hd_fixed_size (disconnect,
+                             GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT,
+                             struct DisconnectInfoMessage,
+                             h),
+    GNUNET_MQ_hd_fixed_size (send_ok,
+                             GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK,
+                             struct SendOkMessage,
+                             h),
+    GNUNET_MQ_hd_var_size (recv,
+                           GNUNET_MESSAGE_TYPE_TRANSPORT_RECV,
+                           struct InboundMessage,
+                           h),
+    GNUNET_MQ_handler_end () };
+  struct GNUNET_MQ_Envelope *env;
+  struct StartMessage *s;
+  uint32_t options;
+
+  h->reconnect_task = NULL;
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n");
+  GNUNET_assert (NULL == h->mq);
+  h->mq =
+    GNUNET_CLIENT_connect (h->cfg, "transport", handlers, &mq_error_handler, h);
+  if (NULL == h->mq)
+    return;
+  env = GNUNET_MQ_msg (s, GNUNET_MESSAGE_TYPE_TRANSPORT_START);
+  options = 0;
+  if (h->check_self)
+    options |= 1;
+  if (NULL != h->handlers)
+    options |= 2;
+  s->options = htonl (options);
+  s->self = h->self;
+  GNUNET_MQ_send (h->mq, env);
+}
+
+
+/**
+ * Disconnect from the transport service.
+ *
+ * @param h transport service to reconnect
+ */
+static void
+disconnect (struct GNUNET_TRANSPORT_CoreHandle *h)
+{
+  GNUNET_CONTAINER_multipeermap_iterate (h->neighbours, &neighbour_delete, h);
+  if (NULL != h->mq)
+  {
+    GNUNET_MQ_destroy (h->mq);
+    h->mq = NULL;
+  }
+}
+
+
+/**
+ * Function that will schedule the job that will try
+ * to connect us again to the client.
+ *
+ * @param h transport service to reconnect
+ */
+static void
+disconnect_and_schedule_reconnect (struct GNUNET_TRANSPORT_CoreHandle *h)
+{
+  GNUNET_assert (NULL == h->reconnect_task);
+  disconnect (h);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Scheduling task to reconnect to transport service in %s.\n",
+       GNUNET_STRINGS_relative_time_to_string (h->reconnect_delay, GNUNET_YES));
+  h->reconnect_task =
+    GNUNET_SCHEDULER_add_delayed (h->reconnect_delay, &reconnect, h);
+  h->reconnect_delay = GNUNET_TIME_STD_BACKOFF (h->reconnect_delay);
+}
+
+
+/**
+ * Checks if a given peer is connected to us and get the message queue.
+ *
+ * @param handle connection to transport service
+ * @param peer the peer to check
+ * @return NULL if disconnected, otherwise message queue for @a peer
+ */
+struct GNUNET_MQ_Handle *
+GNUNET_TRANSPORT_core_get_mq (struct GNUNET_TRANSPORT_CoreHandle *handle,
+                              const struct GNUNET_PeerIdentity *peer)
+{
+  struct Neighbour *n;
+
+  n = neighbour_find (handle, peer);
+  if (NULL == n)
+    return NULL;
+  return n->mq;
+}
+
+
+/**
+ * Notification from the CORE service to the TRANSPORT service
+ * that the CORE service has finished processing a message from
+ * TRANSPORT (via the @code{handlers} of #GNUNET_TRANSPORT_core_connect())
+ * and that it is thus now OK for TRANSPORT to send more messages
+ * for @a pid.
+ *
+ * Used to provide flow control, this is our equivalent to
+ * #GNUNET_SERVICE_client_continue() of an ordinary service.
+ *
+ * Note that due to the use of a window, TRANSPORT may send multiple
+ * messages destined for the same peer even without an intermediate
+ * call to this function. However, CORE must still call this function
+ * once per message received, as otherwise eventually the window will
+ * be full and TRANSPORT will stop providing messages to CORE for @a
+ * pid.
+ *
+ * @param ch core handle
+ * @param pid which peer was the message from that was fully processed by CORE
+ */
+void
+GNUNET_TRANSPORT_core_receive_continue (struct GNUNET_TRANSPORT_CoreHandle *ch,
+                                        const struct GNUNET_PeerIdentity *pid)
+{
+  struct GNUNET_MQ_Envelope *env;
+  struct RecvOkMessage *rok;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Message for %s finished CORE processing, sending RECV_OK.\n",
+       GNUNET_i2s (pid));
+  if (NULL == ch->mq)
+    return;
+  env = GNUNET_MQ_msg (rok, GNUNET_MESSAGE_TYPE_TRANSPORT_RECV_OK);
+  rok->increase_window_delta = htonl (1);
+  rok->peer = *pid;
+  GNUNET_MQ_send (ch->mq, env);
+}
+
+
+/**
+ * Connect to the transport service.  Note that the connection may
+ * complete (or fail) asynchronously.
+ *
+ * @param cfg configuration to use
+ * @param self our own identity (API should check that it matches
+ *             the identity found by transport), or NULL (no check)
+ * @param cls closure for the callbacks
+ * @param rec receive function to call
+ * @param nc function to call on connect events
+ * @param nd function to call on disconnect events
+ * @return NULL on error
+ */
+struct GNUNET_TRANSPORT_CoreHandle *
+GNUNET_TRANSPORT_core_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                               const struct GNUNET_PeerIdentity *self,
+                               const struct GNUNET_MQ_MessageHandler *handlers,
+                               void *cls,
+                               GNUNET_TRANSPORT_NotifyConnect nc,
+                               GNUNET_TRANSPORT_NotifyDisconnect nd)
+{
+  struct GNUNET_TRANSPORT_CoreHandle *h;
+  unsigned int i;
+
+  h = GNUNET_new (struct GNUNET_TRANSPORT_CoreHandle);
+  if (NULL != self)
+  {
+    h->self = *self;
+    h->check_self = GNUNET_YES;
+  }
+  h->cfg = cfg;
+  h->cls = cls;
+  h->nc_cb = nc;
+  h->nd_cb = nd;
+  h->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
+  if (NULL != handlers)
+  {
+    for (i = 0; NULL != handlers[i].cb; i++)
+      ;
+    h->handlers = GNUNET_new_array (i + 1, struct GNUNET_MQ_MessageHandler);
+    GNUNET_memcpy (h->handlers,
+                   handlers,
+                   i * sizeof(struct GNUNET_MQ_MessageHandler));
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service\n");
+  reconnect (h);
+  if (NULL == h->mq)
+  {
+    GNUNET_free (h->handlers);
+    GNUNET_free (h);
+    return NULL;
+  }
+  h->neighbours =
+    GNUNET_CONTAINER_multipeermap_create (STARTING_NEIGHBOURS_SIZE, GNUNET_YES);
+  return h;
+}
+
+
+/**
+ * Disconnect from the transport service.
+ *
+ * @param handle handle to the service as returned from
+ * #GNUNET_TRANSPORT_core_connect()
+ */
+void
+GNUNET_TRANSPORT_core_disconnect (struct GNUNET_TRANSPORT_CoreHandle *handle)
+{
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n");
+  /* this disconnects all neighbours... */
+  disconnect (handle);
+  /* and now we stop trying to connect again... */
+  if (NULL != handle->reconnect_task)
+  {
+    GNUNET_SCHEDULER_cancel (handle->reconnect_task);
+    handle->reconnect_task = NULL;
+  }
+  GNUNET_CONTAINER_multipeermap_destroy (handle->neighbours);
+  handle->neighbours = NULL;
+  GNUNET_free (handle->handlers);
+  handle->handlers = NULL;
+  GNUNET_free (handle);
+}
+
+
+/* end of transport_api_core.c */