1 files changed, 1251 insertions, 0 deletions

diff --git a/src/service/transport/transport-testing-communicator.c b/src/service/transport/transport-testing-communicator.c
new file mode 100644
index 000000000..9ee70fe7b
--- /dev/null
+++ b/src/service/transport/transport-testing-communicator.c
@@ -0,0 +1,1251 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 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 transport/transport-testing-communicator.c
+ * @brief functions related to testing-tng
+ * @author Christian Grothoff
+ * @author Julius Bünger
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_protocols.h"
+#include "gnunet_constants.h"
+#include "transport-testing-communicator.h"
+#include "gnunet_signatures.h"
+#include "transport.h"
+#include "gnunet_hello_uri_lib.h"
+#include <inttypes.h>
+
+#define LOG(kind, ...) GNUNET_log_from (kind, "transport-testing2", __VA_ARGS__)
+
+struct MyClient
+{
+  struct MyClient *prev;
+  struct MyClient *next;
+  /**
+   * @brief Handle to the client
+   */
+  struct GNUNET_SERVICE_Client *client;
+
+  /**
+   * @brief Handle to the client
+   */
+  struct GNUNET_MQ_Handle *c_mq;
+
+  /**
+   * The TCH
+   */
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc;
+
+};
+
+/**
+ * @brief Queue of a communicator and some context
+ */
+struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue
+{
+  /**
+   * @brief Handle to the TransportCommunicator
+   */
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h;
+
+  /**
+   * @brief Envelope to a message that requests the opening of the queue.
+   *
+   * If the client already requests queue(s), but the communicator is not yet
+   * connected, we cannot send the request to open the queue. Save it until the
+   * communicator becomes available and send it then.
+   */
+  struct GNUNET_MQ_Envelope *open_queue_env;
+
+  /**
+   * @brief Peer ID of the peer on the other side of the queue
+   */
+  struct GNUNET_PeerIdentity peer_id;
+
+  /**
+   * @brief Queue ID
+   */
+  uint32_t qid;
+
+  /**
+   * @brief Current message id
+   */
+  uint64_t mid;
+
+  /**
+   * An `enum GNUNET_NetworkType` in NBO.
+   */
+  uint32_t nt;
+
+  /**
+   * Maximum transmission unit.  UINT32_MAX for unlimited.
+   */
+  uint32_t mtu;
+
+  /**
+   * Queue length.  UINT64_MAX for unlimited.
+   */
+  uint64_t q_len;
+
+  /**
+   * Queue prio
+   */
+  uint32_t priority;
+
+  /**
+   * An `enum GNUNET_TRANSPORT_ConnectionStatus` in NBO.
+   */
+  uint32_t cs;
+
+  /**
+   * @brief Next element inside a DLL
+   */
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue *next;
+
+  /**
+   * @brief Previous element inside a DLL
+   */
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue *prev;
+};
+
+
+/**
+ * @brief Handle/Context to a single transmission
+ */
+struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorTransmission
+{
+};
+
+
+/**
+ * @brief Check whether incoming msg indicating available communicator is
+ * correct
+ *
+ * @param cls Closure
+ * @param msg Message struct
+ *
+ * @return GNUNET_YES in case message is correct
+ */
+static int
+check_communicator_available (
+  void *cls,
+  const struct GNUNET_TRANSPORT_CommunicatorAvailableMessage *msg)
+{
+  uint16_t size;
+
+  size = ntohs (msg->header.size) - sizeof(*msg);
+  if (0 == size)
+    return GNUNET_OK; /* receive-only communicator */
+  GNUNET_MQ_check_zero_termination (msg);
+  return GNUNET_OK;
+}
+
+
+/**
+ * @brief Handle new communicator
+ *
+ * Store characteristics of communicator, call respective client callback.
+ *
+ * @param cls Closure - communicator handle
+ * @param msg Message struct
+ */
+static void
+handle_communicator_available (
+  void *cls,
+  const struct GNUNET_TRANSPORT_CommunicatorAvailableMessage *msg)
+{
+  struct MyClient *client = cls;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h =
+    client->tc;
+  uint16_t size;
+  tc_h->c_mq = client->c_mq;
+
+  size = ntohs (msg->header.size) - sizeof(*msg);
+  if (0 == size)
+  {
+    GNUNET_SERVICE_client_continue (client->client);
+    return; /* receive-only communicator */
+  }
+  tc_h->c_characteristics = ntohl (msg->cc);
+  GNUNET_free (tc_h->c_addr_prefix);
+  tc_h->c_addr_prefix = GNUNET_strdup ((const char *) &msg[1]);
+  if (NULL != tc_h->communicator_available_cb)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG, "calling communicator_available_cb()\n");
+    tc_h->communicator_available_cb (tc_h->cb_cls,
+                                     tc_h,
+                                     tc_h->c_characteristics,
+                                     tc_h->c_addr_prefix);
+  }
+  GNUNET_SERVICE_client_continue (client->client);
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "finished communicator_available_cb()\n");
+
+}
+
+
+/**
+ * Incoming message.  Test message is well-formed.
+ *
+ * @param cls the client
+ * @param msg the send message that was sent
+ * @return #GNUNET_OK if message is well-formed
+ */
+static int
+check_communicator_backchannel (void *cls,
+                                const struct
+                                GNUNET_TRANSPORT_CommunicatorBackchannel *msg)
+{
+  // struct TransportClient *tc = cls;
+
+  // if (CT_COMMUNICATOR != tc->type)
+  // {
+  //  GNUNET_break (0);
+  //  return GNUNET_SYSERR;
+  // }
+  // GNUNET_MQ_check_boxed_message (msg);
+  return GNUNET_OK;
+}
+
+
+/**
+ * @brief Receive an incoming message.
+ *
+ * Pass the message to the client.
+ *
+ * @param cls Closure - communicator handle
+ * @param bc_msg Message
+ */
+static void
+handle_communicator_backchannel (void *cls,
+                                 const struct
+                                 GNUNET_TRANSPORT_CommunicatorBackchannel *
+                                 bc_msg)
+{
+  struct MyClient *client = cls;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h =
+    client->tc;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *other_tc_h;
+  struct GNUNET_MessageHeader *msg;
+  msg = (struct GNUNET_MessageHeader *) &bc_msg[1];
+  uint16_t isize = ntohs (msg->size);
+  const char *target_communicator = ((const char *) msg) + isize;
+  struct GNUNET_TRANSPORT_CommunicatorBackchannelIncoming *cbi;
+  struct GNUNET_MQ_Envelope *env;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Received backchannel message\n");
+  if (tc_h->bc_enabled != GNUNET_YES)
+  {
+    GNUNET_SERVICE_client_continue (client->client);
+    return;
+  }
+  /* Find client providing this communicator */
+  /* Finally, deliver backchannel message to communicator */
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Delivering backchannel message of type %u to %s\n",
+       ntohs (msg->type),
+       target_communicator);
+  other_tc_h = tc_h->bc_cb (tc_h, msg, (struct
+                                        GNUNET_PeerIdentity*) &bc_msg->pid);
+  env = GNUNET_MQ_msg_extra (
+    cbi,
+    isize,
+    GNUNET_MESSAGE_TYPE_TRANSPORT_COMMUNICATOR_BACKCHANNEL_INCOMING);
+  cbi->pid = tc_h->peer_id;
+  memcpy (&cbi[1], msg, isize);
+
+
+  GNUNET_MQ_send (other_tc_h->c_mq, env);
+  GNUNET_SERVICE_client_continue (client->client);
+}
+
+
+/**
+ * Address of our peer added.  Test message is well-formed.
+ *
+ * @param cls the client
+ * @param msg the send message that was sent
+ * @return #GNUNET_OK if message is well-formed
+ */
+static int
+check_add_address (void *cls,
+                   const struct GNUNET_TRANSPORT_AddAddressMessage *msg)
+{
+  // if (CT_COMMUNICATOR != tc->type)
+  // {
+  //  GNUNET_break (0);
+  //  return GNUNET_SYSERR;
+  // }
+  GNUNET_MQ_check_zero_termination (msg);
+  return GNUNET_OK;
+}
+
+
+/**
+ * @brief The communicator informs about an address.
+ *
+ * Store address and call client callback.
+ *
+ * @param cls Closure - communicator handle
+ * @param msg Message
+ */
+static void
+handle_add_address (void *cls,
+                    const struct GNUNET_TRANSPORT_AddAddressMessage *msg)
+{
+  struct MyClient *client = cls;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h =
+    client->tc;
+  uint16_t size;
+  size = ntohs (msg->header.size) - sizeof(*msg);
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "received add address cb %u\n", size);
+  if (0 == size)
+    return; /* receive-only communicator */
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "received add address cb %u\n", size);
+  GNUNET_free (tc_h->c_address);
+  tc_h->c_address = GNUNET_strdup ((const char *) &msg[1]);
+  if (NULL != tc_h->add_address_cb)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG, "calling add_address_cb()\n");
+    tc_h->add_address_cb (tc_h->cb_cls,
+                          tc_h,
+                          tc_h->c_address,
+                          GNUNET_TIME_relative_ntoh (msg->expiration),
+                          msg->aid,
+                          ntohl (msg->nt));
+  }
+  GNUNET_SERVICE_client_continue (client->client);
+}
+
+
+/**
+ * Incoming message.  Test message is well-formed.
+ *
+ * @param cls the client
+ * @param msg the send message that was sent
+ * @return #GNUNET_OK if message is well-formed
+ */
+static int
+check_incoming_msg (void *cls,
+                    const struct GNUNET_TRANSPORT_IncomingMessage *msg)
+{
+  // struct TransportClient *tc = cls;
+
+  // if (CT_COMMUNICATOR != tc->type)
+  // {
+  //  GNUNET_break (0);
+  //  return GNUNET_SYSERR;
+  // }
+  GNUNET_MQ_check_boxed_message (msg);
+  return GNUNET_OK;
+}
+
+
+/**
+ * @brief Receive an incoming message.
+ *
+ * Pass the message to the client.
+ *
+ * @param cls Closure - communicator handle
+ * @param inc_msg Message
+ */
+static void
+handle_incoming_msg (void *cls,
+                     const struct GNUNET_TRANSPORT_IncomingMessage *inc_msg)
+{
+  struct MyClient *client = cls;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h =
+    client->tc;
+  struct GNUNET_MessageHeader *msg;
+  msg = (struct GNUNET_MessageHeader *) &inc_msg[1];
+  size_t payload_len = ntohs (msg->size) - sizeof (struct
+                                                   GNUNET_MessageHeader);
+  if (NULL != tc_h->incoming_msg_cb)
+  {
+    tc_h->incoming_msg_cb (tc_h->cb_cls,
+                           tc_h,
+                           (char*) &msg[1],
+                           payload_len);
+  }
+  else
+  {
+    LOG (GNUNET_ERROR_TYPE_WARNING,
+         "Incoming message from communicator but no handler!\n");
+  }
+  if (GNUNET_YES == ntohl (inc_msg->fc_on))
+  {
+    /* send ACK when done to communicator for flow control! */
+    struct GNUNET_MQ_Envelope *env;
+    struct GNUNET_TRANSPORT_IncomingMessageAck *ack;
+
+    env = GNUNET_MQ_msg (ack, GNUNET_MESSAGE_TYPE_TRANSPORT_INCOMING_MSG_ACK);
+    GNUNET_assert (NULL != env);
+    ack->reserved = htonl (0);
+    ack->fc_id = inc_msg->fc_id;
+    ack->sender = inc_msg->sender;
+    GNUNET_MQ_send (tc_h->c_mq, env);
+  }
+
+  GNUNET_SERVICE_client_continue (client->client);
+}
+
+
+/**
+ * @brief Communicator informs that it tries to establish requested queue
+ *
+ * @param cls Closure - communicator handle
+ * @param msg Message
+ */
+static void
+handle_queue_create_ok (void *cls,
+                        const struct GNUNET_TRANSPORT_CreateQueueResponse *msg)
+{
+  struct MyClient *client = cls;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h =
+    client->tc;
+
+  if (NULL != tc_h->queue_create_reply_cb)
+  {
+    tc_h->queue_create_reply_cb (tc_h->cb_cls, tc_h, GNUNET_YES);
+  }
+  GNUNET_SERVICE_client_continue (client->client);
+}
+
+
+/**
+ * @brief Communicator informs that it won't try establishing requested queue.
+ *
+ * It will not do so probably because the address is bougus (see comment to
+ * #GNUNET_MESSAGE_TYPE_TRANSPORT_QUEUE_CREATE_FAIL)
+ *
+ * @param cls Closure - communicator handle
+ * @param msg Message
+ */
+static void
+handle_queue_create_fail (
+  void *cls,
+  const struct GNUNET_TRANSPORT_CreateQueueResponse *msg)
+{
+  struct MyClient *client = cls;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h =
+    client->tc;
+
+  if (NULL != tc_h->queue_create_reply_cb)
+  {
+    tc_h->queue_create_reply_cb (tc_h->cb_cls, tc_h, GNUNET_NO);
+  }
+  GNUNET_SERVICE_client_continue (client->client);
+}
+
+
+/**
+ * New queue became available.  Check message.
+ *
+ * @param cls the client
+ * @param aqm the send message that was sent
+ */
+static int
+check_add_queue_message (void *cls,
+                         const struct GNUNET_TRANSPORT_AddQueueMessage *aqm)
+{
+  GNUNET_MQ_check_zero_termination (aqm);
+  return GNUNET_OK;
+}
+
+
+/**
+ * @brief Handle new queue
+ *
+ * Store context and call client callback.
+ *
+ * @param cls Closure - communicator handle
+ * @param msg Message struct
+ */
+static void
+handle_add_queue_message (void *cls,
+                          const struct GNUNET_TRANSPORT_AddQueueMessage *msg)
+{
+  struct MyClient *client = cls;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h =
+    client->tc;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue *tc_queue;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Got queue with ID %u\n", msg->qid);
+  for (tc_queue = tc_h->queue_head; NULL != tc_queue; tc_queue = tc_queue->next)
+  {
+    if (tc_queue->qid == msg->qid)
+      break;
+  }
+  if (NULL == tc_queue)
+  {
+    tc_queue =
+      GNUNET_new (struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue);
+    tc_queue->tc_h = tc_h;
+    tc_queue->qid = msg->qid;
+    tc_queue->peer_id = msg->receiver;
+    GNUNET_CONTAINER_DLL_insert (tc_h->queue_head, tc_h->queue_tail, tc_queue);
+  }
+  GNUNET_assert (tc_queue->qid == msg->qid);
+  GNUNET_assert (0 == GNUNET_memcmp (&tc_queue->peer_id, &msg->receiver));
+  tc_queue->nt = msg->nt;
+  tc_queue->mtu = ntohl (msg->mtu);
+  tc_queue->cs = msg->cs;
+  tc_queue->priority = ntohl (msg->priority);
+  tc_queue->q_len = GNUNET_ntohll (msg->q_len);
+  if (NULL != tc_h->add_queue_cb)
+  {
+    tc_h->add_queue_cb (tc_h->cb_cls, tc_h, tc_queue, tc_queue->mtu);
+  }
+  GNUNET_SERVICE_client_continue (client->client);
+}
+
+
+/**
+ * @brief Handle new queue
+ *
+ * Store context and call client callback.
+ *
+ * @param cls Closure - communicator handle
+ * @param msg Message struct
+ */
+static void
+handle_update_queue_message (void *cls,
+                             const struct
+                             GNUNET_TRANSPORT_UpdateQueueMessage *msg)
+{
+  struct MyClient *client = cls;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h =
+    client->tc;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue *tc_queue;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Received queue update message for %u with q_len %" PRIu64 "\n",
+       msg->qid, GNUNET_ntohll (msg->q_len));
+  tc_queue = tc_h->queue_head;
+  if (NULL != tc_queue)
+  {
+    while (tc_queue->qid != msg->qid)
+    {
+      tc_queue = tc_queue->next;
+    }
+  }
+  if (NULL == tc_queue)
+  {
+    GNUNET_SERVICE_client_continue (client->client);
+    return;
+  }
+  GNUNET_assert (tc_queue->qid == msg->qid);
+  GNUNET_assert (0 == GNUNET_memcmp (&tc_queue->peer_id, &msg->receiver));
+  tc_queue->nt = msg->nt;
+  tc_queue->mtu = ntohl (msg->mtu);
+  tc_queue->cs = msg->cs;
+  tc_queue->priority = ntohl (msg->priority);
+  // Uncomment this for alternativ 1 of backchannel functionality
+  tc_queue->q_len += GNUNET_ntohll (msg->q_len);
+  // Until here for alternativ 1
+  // Uncomment this for alternativ 2 of backchannel functionality
+  // tc_queue->q_len = GNUNET_ntohll (msg->q_len);
+  // Until here for alternativ 2
+  GNUNET_SERVICE_client_continue (client->client);
+}
+
+
+/**
+ * @brief Shut down the service
+ *
+ * @param cls Closure - Handle to the service
+ */
+static void
+shutdown_service (void *cls)
+{
+  struct GNUNET_SERVICE_Handle *h = cls;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Shutting down service!\n");
+
+  GNUNET_SERVICE_stop (h);
+}
+
+
+/**
+ * @brief Callback called when new Client (Communicator) connects
+ *
+ * @param cls Closure - TransporCommmunicator Handle
+ * @param client Client
+ * @param mq Messagequeue
+ *
+ * @return TransportCommunicator Handle
+ */
+static void *
+connect_cb (void *cls,
+            struct GNUNET_SERVICE_Client *client,
+            struct GNUNET_MQ_Handle *mq)
+{
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h = cls;
+  struct MyClient *new_c;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Client %p connected to %p.\n",
+       client, tc_h);
+  new_c = GNUNET_new (struct MyClient);
+  new_c->client = client;
+  new_c->c_mq = mq;
+  new_c->tc = tc_h;
+  GNUNET_CONTAINER_DLL_insert (tc_h->client_head,
+                               tc_h->client_tail,
+                               new_c);
+
+  if (NULL == tc_h->queue_head)
+    return new_c;
+  /* Iterate over queues. They are yet to be opened. Request opening. */
+  for (struct
+       GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue *tc_queue_iter =
+         tc_h->queue_head;
+       NULL != tc_queue_iter;
+       tc_queue_iter = tc_queue_iter->next)
+  {
+    if (NULL == tc_queue_iter->open_queue_env)
+      continue;
+    /* Send the previously created mq envelope to request the creation of the
+     * queue. */
+    GNUNET_MQ_send (tc_h->c_mq,
+                    tc_queue_iter->open_queue_env);
+    tc_queue_iter->open_queue_env = NULL;
+  }
+  return new_c;
+}
+
+
+/**
+ * @brief Callback called when Client disconnects
+ *
+ * @param cls Closure - TransportCommunicator Handle
+ * @param client Client
+ * @param internal_cls TransporCommmunicator Handle
+ */
+static void
+disconnect_cb (void *cls,
+               struct GNUNET_SERVICE_Client *client,
+               void *internal_cls)
+{
+  struct MyClient *cl = cls;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h = cls;
+
+  for (cl = tc_h->client_head; NULL != cl; cl = cl->next)
+  {
+    if (cl->client != client)
+      continue;
+    GNUNET_CONTAINER_DLL_remove (tc_h->client_head,
+                                 tc_h->client_tail,
+                                 cl);
+    if (cl->c_mq == tc_h->c_mq)
+      tc_h->c_mq = NULL;
+    GNUNET_free (cl);
+    break;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "Client disconnected.\n");
+}
+
+
+/**
+ * Message was transmitted.  Process the request.
+ *
+ * @param cls the client
+ * @param sma the send message that was sent
+ */
+static void
+handle_send_message_ack (void *cls,
+                         const struct GNUNET_TRANSPORT_SendMessageToAck *sma)
+{
+  struct MyClient *client = cls;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h =
+    client->tc;
+  static int mtr = 0;
+  mtr++;
+  if (tc_h->cont != NULL)
+    tc_h->cont (tc_h->cont_cls);
+  GNUNET_SERVICE_client_continue (client->client);
+}
+
+
+/**
+ * @brief Start the communicator part of the transport service
+ *
+ * @param communicator_available Callback to be called when a new communicator
+ * becomes available
+ * @param cfg Configuration
+ */
+static void
+transport_communicator_start (
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h)
+{
+  struct GNUNET_MQ_MessageHandler mh[] = {
+    GNUNET_MQ_hd_var_size (communicator_available,
+                           GNUNET_MESSAGE_TYPE_TRANSPORT_NEW_COMMUNICATOR,
+                           struct GNUNET_TRANSPORT_CommunicatorAvailableMessage,
+                           tc_h),
+    GNUNET_MQ_hd_var_size (communicator_backchannel,
+                           GNUNET_MESSAGE_TYPE_TRANSPORT_COMMUNICATOR_BACKCHANNEL,
+                           struct GNUNET_TRANSPORT_CommunicatorBackchannel,
+                           tc_h),
+    GNUNET_MQ_hd_var_size (add_address,
+                           GNUNET_MESSAGE_TYPE_TRANSPORT_ADD_ADDRESS,
+                           struct GNUNET_TRANSPORT_AddAddressMessage,
+                           tc_h),
+    // GNUNET_MQ_hd_fixed_size (del_address,
+    //                         GNUNET_MESSAGE_TYPE_TRANSPORT_DEL_ADDRESS,
+    //                         struct GNUNET_TRANSPORT_DelAddressMessage,
+    //                         NULL),
+    GNUNET_MQ_hd_var_size (incoming_msg,
+                           GNUNET_MESSAGE_TYPE_TRANSPORT_INCOMING_MSG,
+                           struct GNUNET_TRANSPORT_IncomingMessage,
+                           tc_h),
+    GNUNET_MQ_hd_fixed_size (queue_create_ok,
+                             GNUNET_MESSAGE_TYPE_TRANSPORT_QUEUE_CREATE_OK,
+                             struct GNUNET_TRANSPORT_CreateQueueResponse,
+                             tc_h),
+    GNUNET_MQ_hd_fixed_size (queue_create_fail,
+                             GNUNET_MESSAGE_TYPE_TRANSPORT_QUEUE_CREATE_FAIL,
+                             struct GNUNET_TRANSPORT_CreateQueueResponse,
+                             tc_h),
+    GNUNET_MQ_hd_var_size (add_queue_message,
+                           GNUNET_MESSAGE_TYPE_TRANSPORT_QUEUE_SETUP,
+                           struct GNUNET_TRANSPORT_AddQueueMessage,
+                           tc_h),
+    GNUNET_MQ_hd_fixed_size (update_queue_message,
+                             GNUNET_MESSAGE_TYPE_TRANSPORT_QUEUE_UPDATE,
+                             struct GNUNET_TRANSPORT_UpdateQueueMessage,
+                             tc_h),
+    // GNUNET_MQ_hd_fixed_size (del_queue_message,
+    //                         GNUNET_MESSAGE_TYPE_TRANSPORT_QUEUE_TEARDOWN,
+    //                         struct GNUNET_TRANSPORT_DelQueueMessage,
+    //                         NULL),
+    GNUNET_MQ_hd_fixed_size (send_message_ack,
+                             GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_MSG_ACK,
+                             struct GNUNET_TRANSPORT_SendMessageToAck,
+                             tc_h),
+    GNUNET_MQ_handler_end ()
+  };
+
+
+  tc_h->sh = GNUNET_SERVICE_start ("transport",
+                                   tc_h->cfg,
+                                   &connect_cb,
+                                   &disconnect_cb,
+                                   tc_h,
+                                   mh);
+  GNUNET_assert (NULL != tc_h->sh);
+}
+
+
+/**
+ * @brief Task run at shutdown to kill communicator and clean up
+ *
+ * @param cls Closure - Process of communicator
+ */
+static void
+shutdown_process (struct GNUNET_OS_Process *proc)
+{
+  if (0 != GNUNET_OS_process_kill (proc, SIGTERM))
+  {
+    LOG (GNUNET_ERROR_TYPE_WARNING,
+         "Error shutting down process with SIGERM, trying SIGKILL\n");
+    if (0 != GNUNET_OS_process_kill (proc, SIGKILL))
+    {
+      LOG (GNUNET_ERROR_TYPE_ERROR,
+           "Error shutting down process with SIGERM and SIGKILL\n");
+    }
+  }
+  GNUNET_break (GNUNET_OK == GNUNET_OS_process_wait (proc));
+  GNUNET_OS_process_destroy (proc);
+}
+
+
+/**
+ * @brief Task run at shutdown to kill the statistics process
+ *
+ * @param cls Closure - Process of communicator
+ */
+static void
+shutdown_statistics (void *cls)
+{
+  struct GNUNET_OS_Process *proc = cls;
+  shutdown_process (proc);
+}
+
+
+/**
+ * @brief Task run at shutdown to kill the peerstore process
+ *
+ * @param cls Closure - Process of communicator
+ */
+static void
+shutdown_peerstore (void *cls)
+{
+  struct GNUNET_OS_Process *proc = cls;
+  shutdown_process (proc);
+}
+
+
+/**
+ * @brief Task run at shutdown to kill a communicator process
+ *
+ * @param cls Closure - Process of communicator
+ */
+static void
+shutdown_communicator (void *cls)
+{
+  struct GNUNET_OS_Process *proc = cls;
+  shutdown_process (proc);
+}
+
+
+/**
+ * @brief Start the communicator
+ *
+ * @param cfgname Name of the communicator
+ */
+static void
+communicator_start (
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h,
+  const char *binary_name)
+{
+  char *binary;
+  char *loprefix;
+  char *section_name;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "communicator_start\n");
+
+  section_name = strchr (binary_name, '-');
+  section_name++;
+
+  if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (tc_h->cfg,
+                                                          section_name,
+                                                          "PREFIX",
+                                                          &loprefix))
+    loprefix = GNUNET_strdup ("");
+
+
+  binary = GNUNET_OS_get_libexec_binary_path (binary_name);
+  tc_h->c_proc = GNUNET_OS_start_process_s (GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
+                                            NULL,
+                                            loprefix,
+                                            binary,
+                                            binary_name,
+                                            "-c",
+                                            tc_h->cfg_filename,
+                                            NULL);
+  GNUNET_free (loprefix);
+  if (NULL == tc_h->c_proc)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to start communicator!");
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_INFO, "started communicator\n");
+  GNUNET_free (binary);
+}
+
+
+/**
+ * @brief Task run at shutdown to kill communicator and clean up
+ *
+ * @param cls Closure - Process of communicator
+ */
+static void
+shutdown_nat (void *cls)
+{
+  struct GNUNET_OS_Process *proc = cls;
+  shutdown_process (proc);
+}
+
+
+/**
+ * @brief Task run at shutdown to kill the resolver process
+ *
+ * @param cls Closure - Process of communicator
+ */
+static void
+shutdown_resolver (void *cls)
+{
+  struct GNUNET_OS_Process *proc = cls;
+  shutdown_process (proc);
+}
+
+
+/**
+ * @brief Start Resolver
+ *
+ */
+static void
+resolver_start (struct
+                GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h)
+{
+  char *binary;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "resolver_start\n");
+  binary = GNUNET_OS_get_libexec_binary_path ("gnunet-service-resolver");
+  tc_h->resolver_proc = GNUNET_OS_start_process (
+    GNUNET_OS_INHERIT_STD_OUT_AND_ERR
+    | GNUNET_OS_USE_PIPE_CONTROL,
+    NULL,
+    NULL,
+    NULL,
+    binary,
+    "gnunet-service-resolver",
+    "-c",
+    tc_h->cfg_filename,
+    NULL);
+  if (NULL == tc_h->resolver_proc)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to start resolver service!");
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_INFO, "started resolver service\n");
+  GNUNET_free (binary);
+
+}
+
+
+/**
+ * @brief Start Statistics
+ *
+ */
+static void
+statistics_start (
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h)
+{
+  char *binary;
+
+  binary = GNUNET_OS_get_libexec_binary_path ("gnunet-service-statistics");
+  tc_h->stat_proc = GNUNET_OS_start_process (GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
+                                             NULL,
+                                             NULL,
+                                             NULL,
+                                             binary,
+                                             "gnunet-service-statistics",
+                                             "-c",
+                                             tc_h->cfg_filename,
+                                             NULL);
+  if (NULL == tc_h->stat_proc)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to start Statistics!");
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_INFO, "started Statistics\n");
+  GNUNET_free (binary);
+}
+
+
+/**
+ * @brief Start Peerstore
+ *
+ */
+static void
+peerstore_start (
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h)
+{
+  char *binary;
+
+  binary = GNUNET_OS_get_libexec_binary_path ("gnunet-service-peerstore");
+  tc_h->ps_proc = GNUNET_OS_start_process (GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
+                                           NULL,
+                                           NULL,
+                                           NULL,
+                                           binary,
+                                           "gnunet-service-peerstore",
+                                           "-c",
+                                           tc_h->cfg_filename,
+                                           NULL);
+  if (NULL == tc_h->ps_proc)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to start Peerstore!");
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_INFO, "started Peerstore\n");
+  GNUNET_free (binary);
+}
+
+
+/**
+ * @brief Start NAT
+ *
+ */
+static void
+nat_start (
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h)
+{
+  char *binary;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "nat_start\n");
+  binary = GNUNET_OS_get_libexec_binary_path ("gnunet-service-nat");
+  tc_h->nat_proc = GNUNET_OS_start_process (GNUNET_OS_INHERIT_STD_OUT_AND_ERR
+                                            | GNUNET_OS_USE_PIPE_CONTROL,
+                                            NULL,
+                                            NULL,
+                                            NULL,
+                                            binary,
+                                            "gnunet-service-nat",
+                                            "-c",
+                                            tc_h->cfg_filename,
+                                            NULL);
+  if (NULL == tc_h->nat_proc)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to start NAT!");
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_INFO, "started NAT\n");
+  GNUNET_free (binary);
+}
+
+
+/**
+ * @brief Start communicator part of transport service and communicator
+ *
+ * @param service_name Name of the service
+ * @param cfg Configuration handle
+ * @param communicator_available_cb Callback that is called when a new
+ * @param add_address_cb Callback that is called when a new
+ * communicator becomes available
+ * @param cb_cls Closure to @a communicator_available_cb and @a
+ *
+ * @return Handle to the communicator duo
+ */
+struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *
+GNUNET_TRANSPORT_TESTING_transport_communicator_service_start (
+  const char *service_name,
+  const char *binary_name,
+  const char *cfg_filename,
+  const struct GNUNET_PeerIdentity *peer_id,
+  GNUNET_TRANSPORT_TESTING_CommunicatorAvailableCallback
+  communicator_available_cb,
+  GNUNET_TRANSPORT_TESTING_AddAddressCallback add_address_cb,
+  GNUNET_TRANSPORT_TESTING_QueueCreateReplyCallback queue_create_reply_cb,
+  GNUNET_TRANSPORT_TESTING_AddQueueCallback add_queue_cb,
+  GNUNET_TRANSPORT_TESTING_IncomingMessageCallback incoming_message_cb,
+  GNUNET_TRANSPORT_TESTING_BackchannelCallback bc_cb,
+  void *cb_cls)
+{
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Starting new transport/communicator combo with config %s\n",
+       cfg_filename);
+  tc_h =
+    GNUNET_new (struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle);
+  tc_h->cfg_filename = GNUNET_strdup (cfg_filename);
+  tc_h->cfg = GNUNET_CONFIGURATION_create ();
+  if ((GNUNET_SYSERR == GNUNET_CONFIGURATION_load (tc_h->cfg, cfg_filename)))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                _ ("Malformed configuration file `%s', exit ...\n"),
+                cfg_filename);
+    GNUNET_free (tc_h->cfg_filename);
+    GNUNET_CONFIGURATION_destroy (tc_h->cfg);
+    GNUNET_free (tc_h);
+    return NULL;
+  }
+  tc_h->bc_enabled = GNUNET_CONFIGURATION_get_value_yesno (tc_h->cfg,
+                                                           "communicator-test",
+                                                           "BACKCHANNEL_ENABLED");
+  tc_h->communicator_available_cb = communicator_available_cb;
+  tc_h->add_address_cb = add_address_cb;
+  tc_h->queue_create_reply_cb = queue_create_reply_cb;
+  tc_h->add_queue_cb = add_queue_cb;
+  tc_h->incoming_msg_cb = incoming_message_cb;
+  tc_h->bc_cb = bc_cb;
+  tc_h->peer_id = *peer_id;
+  tc_h->cb_cls = cb_cls;
+
+  /* Start communicator part of service */
+  transport_communicator_start (tc_h);
+  /* Start NAT */
+  nat_start (tc_h);
+  /* Start resolver service */
+  resolver_start (tc_h);
+  /* Start peerstore service */
+  peerstore_start (tc_h);
+  /* Start statistic service */
+  statistics_start (tc_h);
+  /* Schedule start communicator */
+  communicator_start (tc_h,
+                      binary_name);
+  return tc_h;
+}
+
+
+void
+GNUNET_TRANSPORT_TESTING_transport_communicator_service_stop (
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h)
+{
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue *queue;
+  shutdown_communicator (tc_h->c_proc);
+  shutdown_service (tc_h->sh);
+  shutdown_nat (tc_h->nat_proc);
+  shutdown_resolver (tc_h->resolver_proc);
+  shutdown_peerstore (tc_h->ps_proc);
+  shutdown_statistics (tc_h->stat_proc);
+  GNUNET_CONFIGURATION_destroy (tc_h->cfg);
+  while (NULL != (queue = tc_h->queue_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (tc_h->queue_head, tc_h->queue_tail, queue);
+    GNUNET_free (queue);
+  }
+  GNUNET_free (tc_h->c_address);
+  GNUNET_free (tc_h->cfg_filename);
+  GNUNET_free (tc_h->c_addr_prefix);
+  GNUNET_free (tc_h);
+}
+
+
+/**
+ * @brief Instruct communicator to open a queue
+ *
+ * @param tc_h Handle to communicator which shall open queue
+ * @param peer_id Towards which peer
+ * @param address For which address
+ */
+void
+GNUNET_TRANSPORT_TESTING_transport_communicator_open_queue (
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h,
+  const struct GNUNET_PeerIdentity *peer_id,
+  const char *address)
+{
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue *tc_queue;
+  static uint32_t idgen;
+  char *prefix;
+  struct GNUNET_TRANSPORT_CreateQueue *msg;
+  struct GNUNET_MQ_Envelope *env;
+  size_t alen;
+
+  tc_queue =
+    GNUNET_new (struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue);
+  tc_queue->tc_h = tc_h;
+  prefix = GNUNET_HELLO_address_to_prefix (address);
+  if (NULL == prefix)
+  {
+    GNUNET_break (0);  /* We got an invalid address!? */
+    GNUNET_free (tc_queue);
+    return;
+  }
+  GNUNET_free (prefix);
+  alen = strlen (address) + 1;
+  env =
+    GNUNET_MQ_msg_extra (msg, alen, GNUNET_MESSAGE_TYPE_TRANSPORT_QUEUE_CREATE);
+  msg->request_id = htonl (idgen++);
+  tc_queue->qid = msg->request_id;
+  msg->receiver = *peer_id;
+  tc_queue->peer_id = *peer_id;
+  memcpy (&msg[1], address, alen);
+  if (NULL != tc_h->c_mq)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Sending queue create immediately\n");
+    GNUNET_MQ_send (tc_h->c_mq, env);
+  }
+  else
+  {
+    tc_queue->open_queue_env = env;
+  }
+  GNUNET_CONTAINER_DLL_insert (tc_h->queue_head, tc_h->queue_tail, tc_queue);
+}
+
+
+void
+GNUNET_TRANSPORT_TESTING_transport_communicator_send
+  (struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorHandle *tc_h,
+  GNUNET_SCHEDULER_TaskCallback cont,
+  void *cont_cls,
+  const void *payload,
+  size_t payload_size)
+{
+  struct GNUNET_MessageHeader *mh;
+  struct GNUNET_TRANSPORT_SendMessageTo *msg;
+  struct GNUNET_MQ_Envelope *env;
+  size_t inbox_size;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue *tc_queue;
+  struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue *tc_queue_tmp;
+  static struct GNUNET_TRANSPORT_TESTING_TransportCommunicatorQueue *last_queue;
+  tc_queue = NULL;
+
+  for (tc_queue_tmp = tc_h->queue_head;
+       NULL != tc_queue_tmp;
+       tc_queue_tmp = tc_queue_tmp->next)
+  {
+    if (tc_queue_tmp->q_len <= 0)
+      continue;
+    if (NULL == tc_queue)
+    {
+      LOG (GNUNET_ERROR_TYPE_DEBUG,
+           "Selecting queue with prio %u, len %" PRIu64 " and MTU %u\n",
+           tc_queue_tmp->priority,
+           tc_queue_tmp->q_len,
+           tc_queue_tmp->mtu);
+      tc_queue = tc_queue_tmp;
+      continue;
+    }
+    if (tc_queue->priority < tc_queue_tmp->priority)
+    {
+      LOG (GNUNET_ERROR_TYPE_DEBUG,
+           "Selecting queue with prio %u, len %" PRIu64 " and MTU %u\n",
+           tc_queue_tmp->priority,
+           tc_queue_tmp->q_len,
+           tc_queue_tmp->mtu);
+      tc_queue = tc_queue_tmp;
+    }
+  }
+  if (last_queue != tc_queue)
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Selected sending queue changed to %u with length %lu and MTU %u\n",
+                ntohl (tc_queue->qid), (unsigned long) tc_queue->q_len, tc_queue->mtu);
+  GNUNET_assert (NULL != tc_queue);
+  last_queue = tc_queue;
+  // Uncomment this for alternativ 1 of backchannel functionality
+  if (tc_queue->q_len != GNUNET_TRANSPORT_QUEUE_LENGTH_UNLIMITED)
+    tc_queue->q_len--;
+  // Until here for alternativ 1
+  static int msg_count = 0;
+  msg_count++;
+  if (msg_count % 100 == 0)
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Sending %u-th (%lu-th for queue) message on queue %u\n",
+                msg_count, (unsigned long) tc_queue->mid, ntohl (tc_queue->qid));
+  inbox_size = sizeof (struct GNUNET_MessageHeader) + payload_size;
+  env = GNUNET_MQ_msg_extra (msg,
+                             inbox_size,
+                             GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_MSG);
+  GNUNET_assert (NULL != env);
+  msg->qid = tc_queue->qid;
+  msg->mid = tc_queue->mid++;
+  msg->receiver = tc_queue->peer_id;
+  mh = (struct GNUNET_MessageHeader *) &msg[1];
+  mh->size = htons (inbox_size);
+  mh->type = GNUNET_MESSAGE_TYPE_DUMMY;
+  memcpy (&mh[1],
+          payload,
+          payload_size);
+  if (NULL != cont)
+    GNUNET_MQ_notify_sent (env,
+                           cont,
+                           cont_cls);
+  GNUNET_MQ_send (tc_queue->tc_h->c_mq,
+                  env);
+}