gnunet-service-testbed_links.c

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/*
   This file is part of GNUnet.
   Copyright (C) 2008--2013 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
 */

#include "gnunet-service-testbed.h"

#ifdef LOG
#undef LOG
#endif
#define LOG(kind, ...)                                   \
  GNUNET_log_from(kind, "testbed-links", __VA_ARGS__)

#define EVENT_MASK (1LL << GNUNET_TESTBED_ET_OPERATION_FINISHED)


enum LCFContextState {
  INIT,

  DELEGATED_HOST_REGISTERED,

  SLAVE_HOST_REGISTERED,

  FINISHED
};


struct LCFContext {
  struct LCFContext *next;

  struct LCFContext *prev;

  struct Slave *gateway;

  struct GNUNET_SERVICE_Client *client;

  struct GNUNET_TESTBED_Operation *op;

  struct GNUNET_SCHEDULER_Task *timeout_task;

  uint64_t operation_id;

  int is_subordinate;

  enum LCFContextState state;

  uint32_t delegated_host_id;

  uint32_t slave_host_id;
};


struct NeighbourConnectNotification {
  struct NeighbourConnectNotification *next;

  struct NeighbourConnectNotification *prev;

  struct Neighbour *n;

  GST_NeigbourConnectNotifyCallback cb;

  void *cb_cls;
};


struct Neighbour {
  struct GNUNET_TESTBED_Controller *controller;

  struct GNUNET_TESTBED_Operation *conn_op;

  struct NeighbourConnectNotification *nl_head;

  struct NeighbourConnectNotification *nl_tail;

  struct GNUNET_SCHEDULER_Task * notify_task;

  unsigned int reference_cnt;

  unsigned int inactive;

  uint32_t host_id;
};


static struct Neighbour **neighbour_list;

static unsigned int neighbour_list_size;


struct NeighbourConnectCtxt {
  struct NeighbourConnectCtxt *next;

  struct NeighbourConnectCtxt *prev;

  struct Neighbour *n;

  struct GNUNET_SERVICE_Client *client;

  struct GNUNET_SCHEDULER_Task *timeout_task;

  struct NeighbourConnectNotification *nh;

  uint64_t op_id;
};

struct NeighbourConnectCtxt *ncc_head;

struct NeighbourConnectCtxt *ncc_tail;

struct Slave **GST_slave_list;

unsigned int GST_slave_list_size;

static struct Route **route_list;

static struct LCFContext *lcf_head;

static struct LCFContext *lcf_tail;

static struct GNUNET_SCHEDULER_Task * lcf_proc_task_id;

static unsigned int route_list_size;


static void
slave_list_add(struct Slave *slave)
{
  if (slave->host_id >= GST_slave_list_size)
    GST_array_grow_large_enough(GST_slave_list,
                                GST_slave_list_size,
                                slave->host_id);
  GNUNET_assert(NULL == GST_slave_list[slave->host_id]);
  GST_slave_list[slave->host_id] = slave;
}


static int
drop_client_entries(void *cls,
                    const struct GNUNET_HashCode *key,
                    void *value)
{
  struct GNUNET_SERVICE_Client *client = cls;
  struct RegisteredHostContext *rhc = value;
  struct ForwardedOverlayConnectContext *focc;
  struct ForwardedOverlayConnectContext *foccn;

  for (focc = rhc->focc_dll_head; NULL != focc; focc = foccn)
    {
      foccn = focc->next;
      if (focc->client == client)
        GST_cleanup_focc(focc);
    }
  return GNUNET_OK;
}


static void
route_list_add(struct Route *route)
{
  if (route->dest >= route_list_size)
    GST_array_grow_large_enough(route_list, route_list_size, route->dest);
  GNUNET_assert(NULL == route_list[route->dest]);
  route_list[route->dest] = route;
}


static void
neighbour_list_add(struct Neighbour *n)
{
  if (n->host_id >= neighbour_list_size)
    GST_array_grow_large_enough(neighbour_list, neighbour_list_size, n->host_id);
  GNUNET_assert(NULL == neighbour_list[n->host_id]);
  neighbour_list[n->host_id] = n;
}


void
GST_route_list_clear()
{
  unsigned int id;

  for (id = 0; id < route_list_size; id++)
    if (NULL != route_list[id])
      GNUNET_free(route_list[id]);
  GNUNET_free_non_null(route_list);
  route_list = NULL;
}


static int
reghost_free_iterator(void *cls,
                      const struct GNUNET_HashCode *key,
                      void *value)
{
  struct Slave *slave = cls;
  struct RegisteredHostContext *rhc = value;
  struct ForwardedOverlayConnectContext *focc;

  GNUNET_assert(GNUNET_YES ==
                GNUNET_CONTAINER_multihashmap_remove(slave->reghost_map, key,
                                                     value));
  while (NULL != (focc = rhc->focc_dll_head))
    GST_cleanup_focc(focc);
  GNUNET_free(value);
  return GNUNET_YES;
}


static void
kill_slave(struct Slave *slave)
{
  struct HostRegistration *hr_entry;

  while (NULL != (hr_entry = slave->hr_dll_head))
    {
      GNUNET_CONTAINER_DLL_remove(slave->hr_dll_head, slave->hr_dll_tail,
                                  hr_entry);
      GNUNET_free(hr_entry);
    }
  if (NULL != slave->rhandle)
    GNUNET_TESTBED_cancel_registration(slave->rhandle);
  GNUNET_assert(GNUNET_SYSERR !=
                GNUNET_CONTAINER_multihashmap_iterate(slave->reghost_map,
                                                      reghost_free_iterator,
                                                      slave));
  GNUNET_CONTAINER_multihashmap_destroy(slave->reghost_map);
  if (NULL != slave->controller)
    GNUNET_TESTBED_controller_disconnect(slave->controller);
  if (NULL != slave->controller_proc)
    {
      LOG_DEBUG("Stopping a slave\n");
      GNUNET_TESTBED_controller_kill_(slave->controller_proc);
    }
}


static void
destroy_slave(struct Slave *slave)
{
  if (NULL != slave->controller_proc)
    {
      GNUNET_TESTBED_controller_destroy_(slave->controller_proc);
      LOG_DEBUG("Slave stopped\n");
    }
  GST_slave_list[slave->host_id] = NULL;
  GNUNET_free(slave);
}


void
GST_slave_list_clear()
{
  struct Slave *slave;
  unsigned int id;

  for (id = 0; id < GST_slave_list_size; id++)
    {
      slave = GST_slave_list[id];
      if (NULL == slave)
        continue;
      kill_slave(slave);
    }
  for (id = 0; id < GST_slave_list_size; id++)
    {
      slave = GST_slave_list[id];
      if (NULL == slave)
        continue;
      destroy_slave(slave);
    }
  GNUNET_free_non_null(GST_slave_list);
  GST_slave_list = NULL;
}


struct Route *
GST_find_dest_route(uint32_t host_id)
{
  struct Route *route;

  if (route_list_size <= host_id)
    return NULL;
  while (NULL != (route = route_list[host_id]))
    {
      if (route->thru == GST_context->host_id)
        break;
      host_id = route->thru;
    }
  return route;
}


static void
send_controller_link_response(struct GNUNET_SERVICE_Client *client,
                              uint64_t operation_id,
                              const struct GNUNET_CONFIGURATION_Handle *cfg,
                              const char *emsg)
{
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_TESTBED_ControllerLinkResponse *msg;
  char *xconfig;
  size_t config_size;
  size_t xconfig_size;
  uint16_t msize;

  GNUNET_assert((NULL == cfg) || (NULL == emsg));
  xconfig = NULL;
  xconfig_size = 0;
  config_size = 0;
  msize = 0;
  if (NULL != cfg)
    {
      xconfig = GNUNET_TESTBED_compress_cfg_(cfg,
                                             &config_size,
                                             &xconfig_size);
      msize += xconfig_size;
    }
  if (NULL != emsg)
    msize += strlen(emsg);
  env = GNUNET_MQ_msg_extra(msg,
                            msize,
                            GNUNET_MESSAGE_TYPE_TESTBED_LINK_CONTROLLERS_RESULT);
  if (NULL == emsg)
    msg->success = htons(GNUNET_YES);
  msg->operation_id = GNUNET_htonll(operation_id);
  msg->config_size = htons((uint16_t)config_size);
  if (NULL != xconfig)
    {
      GNUNET_memcpy(&msg[1],
                    xconfig,
                    xconfig_size);
      GNUNET_free(xconfig);
    }
  if (NULL != emsg)
    GNUNET_memcpy(&msg[1],
                  emsg,
                  strlen(emsg));
  GNUNET_MQ_send(GNUNET_SERVICE_client_get_mq(client),
                 env);
}


static void
lcf_proc_task(void *cls);


static void
lcf_proc_cc(void *cls,
            const char *emsg)
{
  struct LCFContext *lcf = cls;

  GNUNET_assert(NULL == lcf_proc_task_id);
  switch (lcf->state)
    {
    case INIT:
      if (NULL != emsg)
        goto registration_error;
      lcf->state = DELEGATED_HOST_REGISTERED;
      lcf_proc_task_id = GNUNET_SCHEDULER_add_now(&lcf_proc_task, lcf);
      break;

    case DELEGATED_HOST_REGISTERED:
      if (NULL != emsg)
        goto registration_error;
      lcf->state = SLAVE_HOST_REGISTERED;
      lcf_proc_task_id = GNUNET_SCHEDULER_add_now(&lcf_proc_task, lcf);
      break;

    default:
      GNUNET_assert(0);         /* Shouldn't reach here */
    }
  return;

registration_error:
  LOG(GNUNET_ERROR_TYPE_WARNING,
      "Host registration failed with message: %s\n",
      emsg);
  lcf->state = FINISHED;
  lcf_proc_task_id = GNUNET_SCHEDULER_add_now(&lcf_proc_task,
                                              lcf);
}


static void
lcf_proc_task(void *cls);


static void
lcf_forwarded_operation_timeout(void *cls)
{
  struct LCFContext *lcf = cls;

  lcf->timeout_task = NULL;
  //  GST_forwarded_operation_timeout (lcf->fopc, tc);
  LOG(GNUNET_ERROR_TYPE_WARNING,
      "A forwarded controller link operation has timed out\n");
  send_controller_link_response(lcf->client,
                                lcf->operation_id,
                                NULL,
                                "A forwarded controller link operation has timed out\n");
  GNUNET_assert(NULL == lcf_proc_task_id);
  lcf_proc_task_id = GNUNET_SCHEDULER_add_now(&lcf_proc_task,
                                              lcf);
}


static void
lcf_proc_task(void *cls)
{
  struct LCFContext *lcf = cls;

  lcf_proc_task_id = NULL;
  switch (lcf->state)
    {
    case INIT:
      if (GNUNET_NO ==
          GNUNET_TESTBED_is_host_registered_(GST_host_list
                                             [lcf->delegated_host_id],
                                             lcf->gateway->controller))
        {
          GST_queue_host_registration(lcf->gateway, lcf_proc_cc, lcf,
                                      GST_host_list[lcf->delegated_host_id]);
        }
      else
        {
          lcf->state = DELEGATED_HOST_REGISTERED;
          lcf_proc_task_id = GNUNET_SCHEDULER_add_now(&lcf_proc_task, lcf);
        }
      break;

    case DELEGATED_HOST_REGISTERED:
      if (GNUNET_NO ==
          GNUNET_TESTBED_is_host_registered_(GST_host_list[lcf->slave_host_id],
                                             lcf->gateway->controller))
        {
          GST_queue_host_registration(lcf->gateway, lcf_proc_cc, lcf,
                                      GST_host_list[lcf->slave_host_id]);
        }
      else
        {
          lcf->state = SLAVE_HOST_REGISTERED;
          lcf_proc_task_id = GNUNET_SCHEDULER_add_now(&lcf_proc_task, lcf);
        }
      break;

    case SLAVE_HOST_REGISTERED:
      lcf->op = GNUNET_TESTBED_controller_link(lcf,
                                               lcf->gateway->controller,
                                               GST_host_list[lcf->delegated_host_id],
                                               GST_host_list[lcf->slave_host_id],
                                               lcf->is_subordinate);
      lcf->timeout_task =
        GNUNET_SCHEDULER_add_delayed(GST_timeout,
                                     &lcf_forwarded_operation_timeout,
                                     lcf);
      lcf->state = FINISHED;
      break;

    case FINISHED:
      if (NULL != lcf->op)
        GNUNET_TESTBED_operation_done(lcf->op);
      GNUNET_CONTAINER_DLL_remove(lcf_head,
                                  lcf_tail,
                                  lcf);
      GNUNET_free(lcf);
      if (NULL != lcf_head)
        lcf_proc_task_id = GNUNET_SCHEDULER_add_now(&lcf_proc_task,
                                                    lcf_head);
    }
}


static void
slave_event_cb(void *cls, const struct GNUNET_TESTBED_EventInformation *event)
{
  struct LCFContext *lcf;

  /* We currently only get here when working on LCFContexts */
  GNUNET_assert(GNUNET_TESTBED_ET_OPERATION_FINISHED == event->type);
  lcf = event->op_cls;
  GNUNET_assert(lcf->op == event->op);
  GNUNET_TESTBED_operation_done(lcf->op);
  lcf->op = NULL;
  GNUNET_assert(FINISHED == lcf->state);
  GNUNET_assert(NULL != lcf->timeout_task);
  GNUNET_SCHEDULER_cancel(lcf->timeout_task);
  if (NULL == event->details.operation_finished.emsg)
    send_controller_link_response(lcf->client, lcf->operation_id,
                                  GNUNET_TESTBED_host_get_cfg_
                                    (GST_host_list[lcf->delegated_host_id]),
                                  NULL);
  else
    send_controller_link_response(lcf->client, lcf->operation_id,
                                  NULL,
                                  event->details.operation_finished.emsg);
  GNUNET_assert(NULL == lcf_proc_task_id);
  lcf_proc_task_id = GNUNET_SCHEDULER_add_now(&lcf_proc_task, lcf);
  return;
}


static void
slave_status_cb(void *cls,
                const struct GNUNET_CONFIGURATION_Handle *cfg,
                int status)
{
  struct Slave *slave = cls;
  struct LinkControllersContext *lcc;

  lcc = slave->lcc;
  if (GNUNET_SYSERR == status)
    {
      slave->controller_proc = NULL;
      /* Stop all link controller forwarding tasks since we shutdown here anyway
         and as these tasks they depend on the operation queues which are created
         through GNUNET_TESTBED_controller_connect() and in kill_slave() we call
         the destructor function GNUNET_TESTBED_controller_disconnect() */
      GST_free_lcf();
      kill_slave(slave);
      destroy_slave(slave);
      slave = NULL;
      LOG(GNUNET_ERROR_TYPE_WARNING, "Unexpected slave shutdown\n");
      GNUNET_SCHEDULER_shutdown();      /* We too shutdown */
      goto clean_lcc;
    }
  slave->controller =
    GNUNET_TESTBED_controller_connect(GST_host_list[slave->host_id],
                                      EVENT_MASK, &slave_event_cb,
                                      slave);
  if (NULL != slave->controller)
    {
      send_controller_link_response(lcc->client, lcc->operation_id, cfg, NULL);
    }
  else
    {
      send_controller_link_response(lcc->client, lcc->operation_id, NULL,
                                    "Could not connect to delegated controller");
      kill_slave(slave);
      destroy_slave(slave);
      slave = NULL;
    }

clean_lcc:
  if (NULL != lcc)
    {
      if (NULL != lcc->client)
        {
          GNUNET_SERVICE_client_continue(lcc->client);
          lcc->client = NULL;
        }
      GNUNET_free(lcc);
    }
  if (NULL != slave)
    slave->lcc = NULL;
}


static void
trigger_notifications(struct Neighbour *n);


static void
neighbour_connect_notify_task(void *cls)
{
  struct Neighbour *n = cls;
  struct NeighbourConnectNotification *h;

  GNUNET_assert(NULL != (h = n->nl_head));
  GNUNET_assert(NULL != n->notify_task);
  n->notify_task = NULL;
  GNUNET_assert(NULL != n->controller);
  GNUNET_CONTAINER_DLL_remove(n->nl_head, n->nl_tail, h);
  trigger_notifications(n);
  h->cb(h->cb_cls, n->controller);
  GNUNET_free(h);
}


static void
trigger_notifications(struct Neighbour *n)
{
  GNUNET_assert(NULL != n->conn_op);
  if (NULL == n->nl_head)
    return;
  if (NULL == n->controller)
    return;
  if (NULL != n->notify_task)
    return;
  if (1 == n->inactive)
    {
      GNUNET_assert(0 == n->reference_cnt);
      GNUNET_TESTBED_operation_activate_(n->conn_op);
      n->inactive = 0;
    }
  n->reference_cnt++;
  n->notify_task =
    GNUNET_SCHEDULER_add_now(&neighbour_connect_notify_task, n);
}


static void
opstart_neighbour_conn(void *cls)
{
  struct Neighbour *n = cls;

  GNUNET_assert(NULL != n->conn_op);
  GNUNET_assert(NULL == n->controller);
  LOG_DEBUG("Opening connection to controller on host %u\n", n->host_id);
  n->controller = GNUNET_TESTBED_controller_connect(GST_host_list[n->host_id],
                                                    EVENT_MASK,
                                                    &slave_event_cb,
                                                    NULL);
  trigger_notifications(n);
}


static void
oprelease_neighbour_conn(void *cls)
{
  struct Neighbour *n = cls;

  GNUNET_assert(0 == n->reference_cnt);
  GNUNET_assert(NULL == n->notify_task);
  GNUNET_assert(NULL == n->nl_head);
  if (NULL != n->controller)
    {
      LOG_DEBUG("Closing connection to controller on host %u\n", n->host_id);
      GNUNET_TESTBED_controller_disconnect(n->controller);
      n->controller = NULL;
    }
  n->conn_op = NULL;
  n->inactive = 0;
}


struct NeighbourConnectNotification *
GST_neighbour_get_connection(struct Neighbour *n,
                             GST_NeigbourConnectNotifyCallback cb,
                             void *cb_cls)
{
  struct NeighbourConnectNotification *h;

  GNUNET_assert(NULL != cb);
  LOG_DEBUG("Attempting to get connection to controller on host %u\n",
            n->host_id);
  h = GNUNET_new(struct NeighbourConnectNotification);
  h->n = n;
  h->cb = cb;
  h->cb_cls = cb_cls;
  GNUNET_CONTAINER_DLL_insert_tail(n->nl_head, n->nl_tail, h);
  if (NULL == n->conn_op)
    {
      GNUNET_assert(NULL == n->controller);
      n->conn_op = GNUNET_TESTBED_operation_create_(n, &opstart_neighbour_conn,
                                                    &oprelease_neighbour_conn);
      GNUNET_TESTBED_operation_queue_insert_(GST_opq_openfds, n->conn_op);
      GNUNET_TESTBED_operation_begin_wait_(n->conn_op);
      return h;
    }
  trigger_notifications(n);
  return h;
}


void
GST_neighbour_get_connection_cancel(struct NeighbourConnectNotification *h)
{
  struct Neighbour *n;
  int cleanup_task;

  n = h->n;
  cleanup_task = (h == n->nl_head) ? GNUNET_YES : GNUNET_NO;
  GNUNET_CONTAINER_DLL_remove(n->nl_head, n->nl_tail, h);
  GNUNET_free(h);
  if (GNUNET_NO == cleanup_task)
    return;
  if (NULL == n->notify_task)
    return;
  GNUNET_assert(0 < n->reference_cnt);
  n->reference_cnt--;
  GNUNET_SCHEDULER_cancel(n->notify_task);
  n->notify_task = NULL;
  if (NULL == n->nl_head)
    {
      if ((0 == n->reference_cnt) && (0 == n->inactive))
        {
          n->inactive = 1;
          GNUNET_TESTBED_operation_inactivate_(n->conn_op);
        }
      return;
    }
  trigger_notifications(n);
}


void
GST_neighbour_release_connection(struct Neighbour *n)
{
  GNUNET_assert(0 == n->inactive);
  GNUNET_assert(0 < n->reference_cnt);
  n->reference_cnt--;
  if (0 == n->reference_cnt)
    {
      n->inactive = 1;
      GNUNET_TESTBED_operation_inactivate_(n->conn_op);
    }
}


static void
cleanup_ncc(struct NeighbourConnectCtxt *ncc)
{
  if (NULL != ncc->nh)
    GST_neighbour_get_connection_cancel(ncc->nh);
  if (NULL != ncc->timeout_task)
    GNUNET_SCHEDULER_cancel(ncc->timeout_task);
  GNUNET_CONTAINER_DLL_remove(ncc_head,
                              ncc_tail,
                              ncc);
  GNUNET_free(ncc);
}


void
GST_neighbour_list_clean()
{
  struct Neighbour *n;
  unsigned int id;

  for (id = 0; id < neighbour_list_size; id++)
    {
      if (NULL == (n = neighbour_list[id]))
        continue;
      if (NULL != n->conn_op)
        GNUNET_TESTBED_operation_release_(n->conn_op);
      GNUNET_free(n);
      neighbour_list[id] = NULL;
    }
  GNUNET_free_non_null(neighbour_list);
}


struct Neighbour *
GST_get_neighbour(uint32_t id)
{
  if (neighbour_list_size <= id)
    return NULL;
  return neighbour_list[id];
}


void
GST_free_nccq()
{
  while (NULL != ncc_head)
    cleanup_ncc(ncc_head);
}


static void
timeout_neighbour_connect(void *cls)
{
  struct NeighbourConnectCtxt *ncc = cls;

  ncc->timeout_task = NULL;
  send_controller_link_response(ncc->client,
                                ncc->op_id,
                                NULL,
                                "Could not connect to delegated controller");
  cleanup_ncc(ncc);
}


static void
neighbour_connect_cb(void *cls,
                     struct GNUNET_TESTBED_Controller *c)
{
  struct NeighbourConnectCtxt *ncc = cls;

  GNUNET_SCHEDULER_cancel(ncc->timeout_task);
  ncc->timeout_task = NULL;
  ncc->nh = NULL;
  GST_neighbour_release_connection(ncc->n);
  send_controller_link_response(ncc->client,
                                ncc->op_id,
                                NULL,
                                NULL);
  cleanup_ncc(ncc);
}


struct Neighbour *
GST_create_neighbour(struct GNUNET_TESTBED_Host *host)
{
  struct Neighbour *n;

  n = GNUNET_new(struct Neighbour);
  n->host_id = GNUNET_TESTBED_host_get_id_(host);
  neighbour_list_add(n);    /* just add; connect on-demand */
  return n;
}


void
handle_link_controllers(void *cls,
                        const struct GNUNET_TESTBED_ControllerLinkRequest *msg)
{
  struct GNUNET_SERVICE_Client *client = cls;
  struct LCFContext *lcf;
  struct Route *route;
  struct Route *new_route;
  uint64_t op_id;
  uint32_t delegated_host_id;
  uint32_t slave_host_id;

  if (NULL == GST_context)
    {
      GNUNET_break(0);
      GNUNET_SERVICE_client_drop(client);
      return;
    }
  delegated_host_id = ntohl(msg->delegated_host_id);
  if (delegated_host_id == GST_context->host_id)
    {
      GNUNET_break(0);
      LOG(GNUNET_ERROR_TYPE_WARNING,
          "Trying to link ourselves\n");
      GNUNET_SERVICE_client_drop(client);
      return;
    }
  if ((delegated_host_id >= GST_host_list_size) ||
      (NULL == GST_host_list[delegated_host_id]))
    {
      LOG(GNUNET_ERROR_TYPE_WARNING,
          "Delegated host %u not registered with us\n",
          delegated_host_id);
      GNUNET_SERVICE_client_drop(client);
      return;
    }
  slave_host_id = ntohl(msg->slave_host_id);
  if ((slave_host_id >= GST_host_list_size) ||
      (NULL == GST_host_list[slave_host_id]))
    {
      LOG(GNUNET_ERROR_TYPE_WARNING,
          "Slave host %u not registered with us\n",
          slave_host_id);
      GNUNET_SERVICE_client_drop(client);
      return;
    }
  if (slave_host_id == delegated_host_id)
    {
      LOG(GNUNET_ERROR_TYPE_WARNING,
          "Slave and delegated host are same\n");
      GNUNET_SERVICE_client_drop(client);
      return;
    }
  op_id = GNUNET_ntohll(msg->operation_id);
  if (slave_host_id == GST_context->host_id)    /* Link from us */
    {
      struct Slave *slave;
      struct LinkControllersContext *lcc;

      if (1 != msg->is_subordinate)
        {
          struct Neighbour *n;
          struct NeighbourConnectCtxt *ncc;

          if ((delegated_host_id < neighbour_list_size) &&
              (NULL != neighbour_list[delegated_host_id]))
            {
              GNUNET_break(0);
              GNUNET_SERVICE_client_drop(client);
              return;
            }
          LOG_DEBUG("Received request to establish a link to host %u\n",
                    delegated_host_id);
          n = GST_create_neighbour(GST_host_list[delegated_host_id]);
          ncc = GNUNET_new(struct NeighbourConnectCtxt);
          ncc->n = n;
          ncc->op_id = op_id;
          ncc->client = client;
          ncc->nh = GST_neighbour_get_connection(n,
                                                 &neighbour_connect_cb,
                                                 ncc);
          ncc->timeout_task
            = GNUNET_SCHEDULER_add_delayed(GST_timeout,
                                           &timeout_neighbour_connect,
                                           ncc);
          GNUNET_CONTAINER_DLL_insert_tail(ncc_head,
                                           ncc_tail,
                                           ncc);
          GNUNET_SERVICE_client_continue(client);
          return;
        }
      if ((delegated_host_id < GST_slave_list_size) &&
          (NULL != GST_slave_list[delegated_host_id]))
        {
          GNUNET_break(0);
          GNUNET_SERVICE_client_drop(client);
          return;
        }
      LOG_DEBUG("Received request to start and establish a link to host %u\n",
                delegated_host_id);
      slave = GNUNET_new(struct Slave);
      slave->host_id = delegated_host_id;
      slave->reghost_map = GNUNET_CONTAINER_multihashmap_create(100,
                                                                GNUNET_NO);
      slave_list_add(slave);
      lcc = GNUNET_new(struct LinkControllersContext);
      lcc->operation_id = op_id;
      lcc->client = client;
      slave->lcc = lcc;
      slave->controller_proc
        = GNUNET_TESTBED_controller_start(GST_context->master_ip,
                                          GST_host_list[slave->host_id],
                                          &slave_status_cb,
                                          slave);
      new_route = GNUNET_new(struct Route);
      new_route->dest = delegated_host_id;
      new_route->thru = GST_context->host_id;
      route_list_add(new_route);
      return;
    }

  /* Route the request */
  if (slave_host_id >= route_list_size)
    {
      LOG(GNUNET_ERROR_TYPE_WARNING,
          "No route towards slave host");
      GNUNET_SERVICE_client_drop(client);
      return;
    }
  lcf = GNUNET_new(struct LCFContext);
  lcf->delegated_host_id = delegated_host_id;
  lcf->slave_host_id = slave_host_id;
  route = GST_find_dest_route(slave_host_id);
  GNUNET_assert(NULL != route);         /* because we add routes carefully */
  GNUNET_assert(route->dest < GST_slave_list_size);
  GNUNET_assert(NULL != GST_slave_list[route->dest]);
  lcf->is_subordinate = msg->is_subordinate;
  lcf->state = INIT;
  lcf->operation_id = op_id;
  lcf->gateway = GST_slave_list[route->dest];
  lcf->client = client;
  if (NULL == lcf_head)
    {
      GNUNET_assert(NULL == lcf_proc_task_id);
      GNUNET_CONTAINER_DLL_insert_tail(lcf_head,
                                       lcf_tail,
                                       lcf);
      lcf_proc_task_id = GNUNET_SCHEDULER_add_now(&lcf_proc_task,
                                                  lcf);
    }
  else
    {
      GNUNET_CONTAINER_DLL_insert_tail(lcf_head,
                                       lcf_tail,
                                       lcf);
    }
  /* FIXME: Adding a new route should happen after the controllers are linked
   * successfully */
  if (1 != msg->is_subordinate)
    {
      GNUNET_SERVICE_client_continue(client);
      return;
    }
  if ((delegated_host_id < route_list_size) &&
      (NULL != route_list[delegated_host_id]))
    {
      GNUNET_break_op(0);       /* Are you trying to link delegated host twice
                                 * with is subordinate flag set to GNUNET_YES? */
      GNUNET_SERVICE_client_drop(client);
      return;
    }
  new_route = GNUNET_new(struct Route);
  new_route->dest = delegated_host_id;
  new_route->thru = route->dest;
  route_list_add(new_route);
  GNUNET_SERVICE_client_continue(client);
}


void
GST_link_notify_disconnect(struct GNUNET_SERVICE_Client *client)
{
  struct NeighbourConnectCtxt *ncc;
  struct NeighbourConnectCtxt *nccn;
  struct LCFContext *lcf;
  struct LCFContext *lcfn;

  for (ncc = ncc_head; NULL != ncc; ncc = nccn)
    {
      nccn = ncc->next;
      if (ncc->client == client)
        cleanup_ncc(ncc);
    }
  for (unsigned int i = 0; i < GST_slave_list_size; i++)
    {
      struct Slave *slave = GST_slave_list[i];
      struct LinkControllersContext *lcc;

      if (NULL == slave)
        continue;
      GNUNET_CONTAINER_multihashmap_iterate(slave->reghost_map,
                                            &drop_client_entries,
                                            client);
      lcc = slave->lcc;
      if (NULL == lcc)
        continue;
      if (lcc->client == client)
        {
          slave->lcc = NULL;
          GNUNET_free(lcc);
        }
    }
  for (lcf = lcf_head; NULL != lcf; lcf = lcfn)
    {
      lcfn = lcf->next;
      if ((NULL != lcf) &&
          (client == lcf->client))
        {
          if (NULL != lcf->op)
            GNUNET_TESTBED_operation_done(lcf->op);
          GNUNET_CONTAINER_DLL_remove(lcf_head,
                                      lcf_tail,
                                      lcf);
          GNUNET_free(lcf);
        }
    }
}


void
GST_free_lcf()
{
  struct LCFContext *lcf;

  if (NULL != lcf_head)
    {
      if (NULL != lcf_proc_task_id)
        {
          GNUNET_SCHEDULER_cancel(lcf_proc_task_id);
          lcf_proc_task_id = NULL;
        }
    }
  GNUNET_assert(NULL == lcf_proc_task_id);
  for (lcf = lcf_head; NULL != lcf; lcf = lcf_head)
    {
      if (NULL != lcf->op)
        GNUNET_TESTBED_operation_done(lcf->op);
      if (NULL != lcf->timeout_task)
        GNUNET_SCHEDULER_cancel(lcf->timeout_task);
      GNUNET_CONTAINER_DLL_remove(lcf_head,
                                  lcf_tail,
                                  lcf);
      GNUNET_free(lcf);
    }
}