/*
   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
 */

/**
 * @file testbed/testbed_api_testbed.c
 * @brief high-level testbed management
 * @author Christian Grothoff
 * @author Sree Harsha Totakura
 */

#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_testbed_service.h"
#include "testbed_api.h"
#include "testbed_api_peers.h"
#include "testbed_api_hosts.h"
#include "testbed_api_topology.h"

/**
 * Generic loggins shorthand
 */
#define LOG(kind, ...)                                           \
  GNUNET_log_from (kind, "testbed-api-testbed", __VA_ARGS__)

/**
 * Debug logging shortcut
 */
#define DEBUG(...)                              \
  LOG (GNUNET_ERROR_TYPE_DEBUG, __VA_ARGS__)

/**
 * The default setup timeout in seconds
 */
#define DEFAULT_SETUP_TIMEOUT 300


/**
 * Configuration section for testbed
 */
#define TESTBED_CONFIG_SECTION "testbed"

/**
 * Option string for the maximum number of edges a peer is permitted to have
 * while generating scale free topology
 */
#define SCALE_FREE_CAP "SCALE_FREE_TOPOLOGY_CAP"

/**
 * Option string for the number of edges to be established when adding a new
 * node to the scale free network
 */
#define SCALE_FREE_M "SCALE_FREE_TOPOLOGY_M"

/**
 * Context information for the operation we start
 */
struct RunContextOperation
{
  /**
   * The testbed operation handle
   */
  struct GNUNET_TESTBED_Operation *op;

  /**
   * Context information for GNUNET_TESTBED_run()
   */
  struct GNUNET_TESTBED_RunHandle *rc;

  /**
   * Closure
   */
  void *cls;
};


/**
 * States of RunContext
 */
enum State
{
  /**
   * Initial state
   */
  RC_INIT = 0,

  /**
   * Controllers on given hosts started and linked
   */
  RC_LINKED,

  /**
   * Peers are created
   */
  RC_PEERS_CREATED,

  /**
   * The testbed run is ready and the master callback can be called now. At this
   * time the peers are all started and if a topology is provided in the
   * configuration the topology would have been attempted
   */
  RC_READY,

  /* /\** */
  /*  * Peers are stopped */
  /*  *\/ */
  /* RC_PEERS_STOPPED, */

  /* /\** */
  /*  * Peers are destroyed */
  /*  *\/ */
  /* RC_PEERS_DESTROYED */

  /**
   * All peers shutdown (stopped and destroyed)
   */
  RC_PEERS_SHUTDOWN
};


/**
 * Context for host compability checks
 */
struct CompatibilityCheckContext
{
  /**
   * The run context
   */
  struct GNUNET_TESTBED_RunHandle *rc;

  /**
   * Handle for the compability check
   */
  struct GNUNET_TESTBED_HostHabitableCheckHandle *h;

  /**
   * Index of the host in the run context's hosts array
   */
  unsigned int index;
};


/**
 * Testbed Run Handle
 */
struct GNUNET_TESTBED_RunHandle
{
  /**
   * The controller handle
   */
  struct GNUNET_TESTBED_Controller *c;

  /**
   * The configuration of the controller. This is based on the cfg given to the
   * function GNUNET_TESTBED_run(). We also use this config as a template while
   * for peers
   */
  struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Handle to the host on which the controller runs
   */
  struct GNUNET_TESTBED_Host *h;

  /**
   * The handle to the controller process
   */
  struct GNUNET_TESTBED_ControllerProc *cproc;

  /**
   * The callback to use as controller callback
   */
  GNUNET_TESTBED_ControllerCallback cc;

  /**
   * The pointer to the controller callback
   */
  void *cc_cls;

  /**
   * The trusted IP string
   */
  char *trusted_ip;

  /**
   * TestMaster callback to call when testbed initialization is done
   */
  GNUNET_TESTBED_TestMaster test_master;

  /**
   * The closure for the TestMaster callback
   */
  void *test_master_cls;

  /**
   * A hashmap for operations started by us
   */
  struct GNUNET_CONTAINER_MultiHashMap32 *rcop_map;

  /**
   * An array of hosts loaded from the hostkeys file
   */
  struct GNUNET_TESTBED_Host **hosts;

  /**
   * Array of compatibility check contexts
   */
  struct CompatibilityCheckContext *hclist;

  /**
   * Array of peers which we create
   */
  struct GNUNET_TESTBED_Peer **peers;

  /**
   * The topology generation operation. Will be null if no topology is set in
   * the configuration
   */
  struct GNUNET_TESTBED_Operation *topology_operation;

  /**
   * The file containing topology data. Only used if the topology is set to 'FROM_FILE'
   */
  char *topo_file;

  /**
   * Host registration handle
   */
  struct GNUNET_TESTBED_HostRegistrationHandle *reg_handle;

  /**
   * Profiling start time
   */
  struct GNUNET_TIME_Absolute pstart_time;

  /**
   * Host registration task
   */
  struct GNUNET_SCHEDULER_Task *register_hosts_task;

  /**
   * Task to be run of a timeout
   */
  struct GNUNET_SCHEDULER_Task *timeout_task;

  /**
   * Task run upon shutdown interrupts
   */
  struct GNUNET_SCHEDULER_Task *interrupt_task;

  /**
   * The event mask for the controller
   */
  uint64_t event_mask;

  /**
   * State of this context
   */
  enum State state;

  /**
   * The topology which has to be achieved with the peers started in this context
   */
  enum GNUNET_TESTBED_TopologyOption topology;

  /**
   * Have we already shutdown
   */
  int shutdown;

  /**
   * Number of hosts in the given host file
   */
  unsigned int num_hosts;

  /**
   * Number of registered hosts. Also used as a counter while checking
   * habitabillity of hosts
   */
  unsigned int reg_hosts;

  /**
   * Current peer count for an operation; Set this to 0 and increment for each
   * successful operation on a peer
   */
  unsigned int peer_count;

  /**
   * number of peers to start
   */
  unsigned int num_peers;

  /**
   * Expected overlay connects. Should be zero if no topology is relavant
   */
  unsigned int num_oc;

  /**
   * Number of random links to established
   */
  unsigned int random_links;

  /**
   * the number of overlay link connection attempts that succeeded
   */
  unsigned int links_succeeded;

  /**
   * the number of overlay link connection attempts that failed
   */
  unsigned int links_failed;
};


/**
 * Return a 32-bit key from a pointer
 *
 * @param rcop the pointer
 * @return 32-bit key
 */
static uint32_t
rcop_key (void *rcop)
{
  return *((uint32_t *) &rcop);
}


/**
 * Context information used for finding a pointer in the rcop_map
 */
struct SearchContext
{
  /**
   * The operation pointer to look for
   */
  struct GNUNET_TESTBED_Operation *query;

  /**
   * The Run context operation which has the operation being queried
   */
  struct RunContextOperation *result;
};


/**
 * Iterator for searching over the elements matching a given query
 *
 * @param cls the SearchContext
 * @param key the 32-bit key
 * @param value the RunContextOperation element
 * @return GNUNET_YES to continue iteration; GNUNET_NO to cancel it
 */
static int
search_iterator (void *cls, uint32_t key, void *value)
{
  struct RunContextOperation *rcop = value;
  struct SearchContext *sc = cls;

  GNUNET_assert (NULL != rcop);
  if (sc->query == rcop->op)
  {
    GNUNET_assert (NULL == sc->result);
    sc->result = rcop;
    return GNUNET_NO;
  }
  return GNUNET_YES;
}


/**
 * Initiate a search for the given operation in the rcop_map
 *
 * @param rc the RunContext whose rcop_map will be searched for the given
 *          operation
 * @param op the given operation to search for
 * @return the matching RunContextOperation if found; NULL if not
 */
static struct RunContextOperation *
search_rcop (struct GNUNET_TESTBED_RunHandle *rc, struct
             GNUNET_TESTBED_Operation *op)
{
  struct SearchContext sc;

  sc.query = op;
  sc.result = NULL;
  if (GNUNET_SYSERR ==
      GNUNET_CONTAINER_multihashmap32_get_multiple (rc->rcop_map,
                                                    rcop_key (op),
                                                    &search_iterator,
                                                    &sc))
  {
    GNUNET_assert (NULL != sc.result);
    return sc.result;
  }
  return NULL;
}


/**
 * Insert an RunContextOperation into the rcop_map of the given RunContext
 *
 * @param rc the RunContext into whose map is to be used for insertion
 * @param rcop the RunContextOperation to insert
 */
static void
insert_rcop (struct GNUNET_TESTBED_RunHandle *rc, struct
             RunContextOperation *rcop)
{
  GNUNET_assert (GNUNET_OK ==
                 GNUNET_CONTAINER_multihashmap32_put (rc->rcop_map,
                                                      rcop_key (rcop->op), rcop,
                                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE));
}


/**
 * Remove a RunContextOperation from the rcop_map of the given RunContext
 *
 * @param rc the RunContext from whose map the given RunContextOperaton has to
 *          be removed
 * @param rcop the RunContextOperation
 */
static void
remove_rcop (struct GNUNET_TESTBED_RunHandle *rc, struct
             RunContextOperation *rcop)
{
  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap32_remove (rc->rcop_map,
                                                         rcop_key (rcop->op),
                                                         rcop));
}


/**
 * Assuming all peers have been destroyed cleanup run handle
 *
 * @param rc the run context
 */
static void
cleanup (struct GNUNET_TESTBED_RunHandle *rc)
{
  unsigned int hid;

  GNUNET_assert (NULL == rc->register_hosts_task);
  GNUNET_assert (NULL == rc->reg_handle);
  GNUNET_assert (NULL == rc->peers);
  GNUNET_assert (NULL == rc->hclist);
  GNUNET_assert (RC_PEERS_SHUTDOWN == rc->state);
  GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap32_size (rc->rcop_map));
  GNUNET_CONTAINER_multihashmap32_destroy (rc->rcop_map);
  if (NULL != rc->c)
    GNUNET_TESTBED_controller_disconnect (rc->c);
  if (NULL != rc->cproc)
    GNUNET_TESTBED_controller_stop (rc->cproc);
  if (NULL != rc->h)
    GNUNET_TESTBED_host_destroy (rc->h);
  for (hid = 0; hid < rc->num_hosts; hid++)
    GNUNET_TESTBED_host_destroy (rc->hosts[hid]);
  GNUNET_free (rc->hosts);
  if (NULL != rc->cfg)
    GNUNET_CONFIGURATION_destroy (rc->cfg);
  GNUNET_free (rc->topo_file);
  GNUNET_free (rc->trusted_ip);
  GNUNET_free (rc);
}


/**
 * Iterator for cleaning up elements from rcop_map
 *
 * @param cls the RunContext
 * @param key the 32-bit key
 * @param value the RunContextOperation element
 * @return always GNUNET_YES
 */
static int
rcop_cleanup_iterator (void *cls, uint32_t key, void *value)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;
  struct RunContextOperation *rcop = value;

  GNUNET_assert (rc == rcop->rc);
  remove_rcop (rc, rcop);
  GNUNET_TESTBED_operation_done (rcop->op);
  GNUNET_free (rcop);
  return GNUNET_YES;
}


/**
 * Cancels operations and tasks which are assigned to the given run context
 *
 * @param rc the RunContext
 */
static void
rc_cleanup_operations (struct GNUNET_TESTBED_RunHandle *rc)
{
  struct CompatibilityCheckContext *hc;
  unsigned int nhost;

  if (NULL != rc->hclist)
  {
    for (nhost = 0; nhost < rc->num_hosts; nhost++)
    {
      hc = &rc->hclist[nhost];
      if (NULL != hc->h)
        GNUNET_TESTBED_is_host_habitable_cancel (hc->h);
    }
    GNUNET_free (rc->hclist);
    rc->hclist = NULL;
  }
  /* Stop register hosts task if it is running */
  if (NULL != rc->register_hosts_task)
  {
    GNUNET_SCHEDULER_cancel (rc->register_hosts_task);
    rc->register_hosts_task = NULL;
  }
  if (NULL != rc->timeout_task)
  {
    GNUNET_SCHEDULER_cancel (rc->timeout_task);
    rc->timeout_task = NULL;
  }
  if (NULL != rc->reg_handle)
  {
    GNUNET_TESTBED_cancel_registration (rc->reg_handle);
    rc->reg_handle = NULL;
  }
  if (NULL != rc->topology_operation)
  {
    GNUNET_TESTBED_operation_done (rc->topology_operation);
    rc->topology_operation = NULL;
  }
  /* cancel any exiting operations */
  GNUNET_assert (GNUNET_SYSERR !=
                 GNUNET_CONTAINER_multihashmap32_iterate (rc->rcop_map,
                                                          &rcop_cleanup_iterator,
                                                          rc));
}


/**
 * Cancels the scheduled interrupt task
 *
 * @param rc the run context
 */
static void
cancel_interrupt_task (struct GNUNET_TESTBED_RunHandle *rc)
{
  GNUNET_SCHEDULER_cancel (rc->interrupt_task);
  rc->interrupt_task = NULL;
}


/**
 * This callback will be called when all the operations are completed
 * (done/cancelled)
 *
 * @param cls run context
 */
static void
wait_op_completion (void *cls)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;
  struct RunContextOperation *rcop;

  if ((NULL == rc->cproc)
      || (NULL == rc->c)
      || (GNUNET_YES == rc->shutdown))
  {
    if (NULL != rc->peers)
    {
      GNUNET_free (rc->peers);
      rc->peers = NULL;
    }
    goto cleanup_;
  }
  if (NULL == rc->peers)
    goto cleanup_;
  rc->shutdown = GNUNET_YES;
  rcop = GNUNET_new (struct RunContextOperation);
  rcop->rc = rc;
  rcop->op = GNUNET_TESTBED_shutdown_peers (rc->c, rcop, NULL, NULL);
  GNUNET_assert (NULL != rcop->op);
  DEBUG ("Shutting down peers\n");
  rc->pstart_time = GNUNET_TIME_absolute_get ();
  insert_rcop (rc, rcop);
  return;

cleanup_:
  rc->state = RC_PEERS_SHUTDOWN;
  cancel_interrupt_task (rc);
  cleanup (rc);
}


/**
 * Task run upon interrupts (SIGINT, SIGTERM) and upon scheduler shutdown.
 *
 * @param cls the RunContext which has to be acted upon
 */
static void
interrupt (void *cls)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;
  struct GNUNET_TESTBED_Controller *c = rc->c;
  unsigned int size;

  /* reschedule */
  rc->interrupt_task = GNUNET_SCHEDULER_add_shutdown (&interrupt, rc);
  rc_cleanup_operations (rc);
  if ((GNUNET_NO == rc->shutdown) &&
      (NULL != c) &&
      (NULL != c->opc_map) &&
      (0 != (size = GNUNET_CONTAINER_multihashmap32_size (c->opc_map))))
  {
    LOG (GNUNET_ERROR_TYPE_WARNING,
         "Shutdown postponed as there are %u operations currently active\n",
         size);
    c->opcq_empty_cb = &wait_op_completion;
    c->opcq_empty_cls = rc;
    return;
  }
  wait_op_completion (rc);
}


/**
 * Function to return the string representation of the duration between current
 * time and `pstart_time' in `RunContext'
 *
 * @param rc the RunContext
 * @return the representation string; this is NOT reentrant
 */
static const char *
prof_time (struct GNUNET_TESTBED_RunHandle *rc)
{
  struct GNUNET_TIME_Relative ptime;

  ptime = GNUNET_TIME_absolute_get_duration (rc->pstart_time);
  return GNUNET_STRINGS_relative_time_to_string (ptime, GNUNET_YES);
}


/**
 * Task for starting peers
 *
 * @param cls the RunHandle
 */
static void
start_peers_task (void *cls)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;
  struct RunContextOperation *rcop;
  unsigned int peer;

  DEBUG ("Starting Peers\n");
  rc->pstart_time = GNUNET_TIME_absolute_get ();
  for (peer = 0; peer < rc->num_peers; peer++)
  {
    rcop = GNUNET_new (struct RunContextOperation);
    rcop->rc = rc;
    rcop->op = GNUNET_TESTBED_peer_start (NULL, rc->peers[peer], NULL, NULL);
    GNUNET_assert (NULL != rcop->op);
    rcop->cls = rc->peers[peer];
    insert_rcop (rc, rcop);
  }
  rc->peer_count = 0;
}


/**
 * Functions of this signature are called when a peer has been successfully
 * created
 *
 * @param cls the closure from GNUNET_TESTBED_peer_create()
 * @param peer the handle for the created peer; NULL on any error during
 *          creation
 * @param emsg NULL if peer is not NULL; else MAY contain the error description
 */
static void
peer_create_cb (void *cls, struct GNUNET_TESTBED_Peer *peer, const char *emsg)
{
  struct RunContextOperation *rcop = cls;
  struct GNUNET_TESTBED_RunHandle *rc;

  GNUNET_assert (NULL != rcop);
  GNUNET_assert (NULL != (rc = rcop->rc));
  remove_rcop (rc, rcop);
  GNUNET_TESTBED_operation_done (rcop->op);
  GNUNET_free (rcop);
  if (NULL == peer)
  {
    if (NULL != emsg)
      LOG (GNUNET_ERROR_TYPE_ERROR, "Error while creating a peer: %s\n",
           emsg);
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  rc->peers[rc->peer_count] = peer;
  rc->peer_count++;
  if (rc->peer_count < rc->num_peers)
    return;
  DEBUG ("%u peers created in %s\n", rc->num_peers, prof_time (rc));
  rc->state = RC_PEERS_CREATED;
  GNUNET_SCHEDULER_add_now (&start_peers_task, rc);
}


/**
 * call test master callback
 *
 * @param rc the RunContext
 */
static void
call_master (struct GNUNET_TESTBED_RunHandle *rc)
{
  GNUNET_SCHEDULER_cancel (rc->timeout_task);
  rc->timeout_task = NULL;
  if (NULL != rc->test_master)
    rc->test_master (rc->test_master_cls, rc, rc->num_peers, rc->peers,
                     rc->links_succeeded, rc->links_failed);
}


/**
 * Callbacks of this type are called when topology configuration is completed
 *
 * @param cls the operation closure given to
 *          GNUNET_TESTBED_overlay_configure_topology_va() and
 *          GNUNET_TESTBED_overlay_configure() calls
 * @param nsuccess the number of successful overlay connects
 * @param nfailures the number of overlay connects which failed
 */
static void
topology_completion_callback (void *cls, unsigned int nsuccess,
                              unsigned int nfailures)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;

  DEBUG ("Overlay topology generated in %s\n", prof_time (rc));
  GNUNET_TESTBED_operation_done (rc->topology_operation);
  rc->topology_operation = NULL;
  rc->links_succeeded = nsuccess;
  rc->links_failed = nfailures;
  rc->state = RC_READY;
  call_master (rc);
}


/**
 * Function to create peers
 *
 * @param rc the RunContext
 */
static void
create_peers (struct GNUNET_TESTBED_RunHandle *rc)
{
  struct RunContextOperation *rcop;
  unsigned int peer;

  DEBUG ("Creating peers\n");
  rc->pstart_time = GNUNET_TIME_absolute_get ();
  rc->peers =
    GNUNET_malloc (sizeof(struct GNUNET_TESTBED_Peer *) * rc->num_peers);
  GNUNET_assert (NULL != rc->c);
  rc->peer_count = 0;
  for (peer = 0; peer < rc->num_peers; peer++)
  {
    rcop = GNUNET_new (struct RunContextOperation);
    rcop->rc = rc;
    rcop->op =
      GNUNET_TESTBED_peer_create (rc->c,
                                  (0 ==
                                   rc->num_hosts) ? rc->h : rc->hosts[peer
                                                                      % rc->
                                                                      num_hosts],
                                  rc->cfg, &peer_create_cb, rcop);
    GNUNET_assert (NULL != rcop->op);
    insert_rcop (rc, rcop);
  }
}


/**
 * Signature of the event handler function called by the
 * respective event controller.
 *
 * @param cls closure
 * @param event information about the event
 */
static void
event_cb (void *cls, const struct GNUNET_TESTBED_EventInformation *event)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;
  struct RunContextOperation *rcop;

  if (RC_INIT == rc->state)
  {
    switch (event->type)
    {
    case GNUNET_TESTBED_ET_OPERATION_FINISHED:
      rcop = event->op_cls;
      if (NULL != event->details.operation_finished.emsg)
      {
        LOG (GNUNET_ERROR_TYPE_ERROR, _ (
               "Linking controllers failed. Exiting"));
        GNUNET_SCHEDULER_shutdown ();
      }
      else
        rc->reg_hosts++;
      GNUNET_assert (event->op == rcop->op);
      remove_rcop (rc, rcop);
      GNUNET_TESTBED_operation_done (rcop->op);
      GNUNET_free (rcop);
      if (rc->reg_hosts == rc->num_hosts)
      {
        rc->state = RC_LINKED;
        create_peers (rc);
      }
      return;

    default:
      GNUNET_break (0);
      GNUNET_SCHEDULER_shutdown ();
      return;
    }
  }
  if (GNUNET_TESTBED_ET_OPERATION_FINISHED != event->type)
    goto call_cc;
  if (NULL == (rcop = search_rcop (rc, event->op)))
    goto call_cc;
  remove_rcop (rc, rcop);
  GNUNET_TESTBED_operation_done (rcop->op);
  GNUNET_free (rcop);
  if ((GNUNET_NO == rc->shutdown)
      && (NULL != event->details.operation_finished.emsg))
  {
    LOG (GNUNET_ERROR_TYPE_ERROR, "A operation has failed with error: %s\n",
         event->details.operation_finished.emsg);
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  GNUNET_assert (GNUNET_YES == rc->shutdown);
  switch (rc->state)
  {
  case RC_LINKED:
  case RC_PEERS_CREATED:
  case RC_READY:
    rc->state = RC_PEERS_SHUTDOWN;
    GNUNET_free (rc->peers);
    rc->peers = NULL;
    DEBUG ("Peers shut down in %s\n", prof_time (rc));
    GNUNET_SCHEDULER_shutdown ();
    break;

  default:
    GNUNET_assert (0);
  }
  return;

call_cc:
  if ((0 != (rc->event_mask & (1LL << event->type))) && (NULL != rc->cc))
    rc->cc (rc->cc_cls, event);
  if (GNUNET_TESTBED_ET_PEER_START != event->type)
    return;
  if (NULL == (rcop = search_rcop (rc, event->op))) /* Not our operation */
    return;
  remove_rcop (rc, rcop);
  GNUNET_TESTBED_operation_done (rcop->op);
  GNUNET_free (rcop);
  rc->peer_count++;
  if (rc->peer_count < rc->num_peers)
    return;
  DEBUG ("%u peers started in %s\n", rc->num_peers, prof_time (rc));
  if (GNUNET_TESTBED_TOPOLOGY_NONE != rc->topology)
  {
    switch (rc->topology)
    {
    case GNUNET_TESTBED_TOPOLOGY_NONE:
      GNUNET_assert (0);

    case GNUNET_TESTBED_TOPOLOGY_ERDOS_RENYI:
    case GNUNET_TESTBED_TOPOLOGY_SMALL_WORLD_RING:
    case GNUNET_TESTBED_TOPOLOGY_SMALL_WORLD:
      rc->topology_operation =
        GNUNET_TESTBED_overlay_configure_topology (NULL, rc->num_peers,
                                                   rc->peers, &rc->num_oc,
                                                   &topology_completion_callback,
                                                   rc,
                                                   rc->topology,
                                                   rc->random_links,
                                                   GNUNET_TESTBED_TOPOLOGY_OPTION_END);
      break;

    case GNUNET_TESTBED_TOPOLOGY_FROM_FILE:
      GNUNET_assert (NULL != rc->topo_file);
      rc->topology_operation =
        GNUNET_TESTBED_overlay_configure_topology (NULL, rc->num_peers,
                                                   rc->peers, &rc->num_oc,
                                                   &topology_completion_callback,
                                                   rc,
                                                   rc->topology,
                                                   rc->topo_file,
                                                   GNUNET_TESTBED_TOPOLOGY_OPTION_END);
      break;

    case GNUNET_TESTBED_TOPOLOGY_SCALE_FREE:
      {
        unsigned long long number;
        unsigned int cap;
        GNUNET_assert (GNUNET_OK ==
                       GNUNET_CONFIGURATION_get_value_number (rc->cfg,
                                                              TESTBED_CONFIG_SECTION,
                                                              SCALE_FREE_CAP,
                                                              &number));
        cap = (unsigned int) number;
        GNUNET_assert (GNUNET_OK ==
                       GNUNET_CONFIGURATION_get_value_number (rc->cfg,
                                                              TESTBED_CONFIG_SECTION,
                                                              SCALE_FREE_M,
                                                              &number));
        rc->topology_operation =
          GNUNET_TESTBED_overlay_configure_topology (NULL, rc->num_peers,
                                                     rc->peers, &rc->num_oc,
                                                     &
                                                     topology_completion_callback,
                                                     rc,
                                                     rc->topology,
                                                     cap,      /* uint16_t */
                                                     (unsigned int) number,   /* uint8_t */
                                                     GNUNET_TESTBED_TOPOLOGY_OPTION_END);
      }
      break;

    default:
      rc->topology_operation =
        GNUNET_TESTBED_overlay_configure_topology (NULL, rc->num_peers,
                                                   rc->peers, &rc->num_oc,
                                                   &topology_completion_callback,
                                                   rc,
                                                   rc->topology,
                                                   GNUNET_TESTBED_TOPOLOGY_OPTION_END);
    }
    if (NULL == rc->topology_operation)
      LOG (GNUNET_ERROR_TYPE_WARNING,
           "Not generating a topology. Check number of peers\n");
    else
    {
      DEBUG ("Creating overlay topology\n");
      rc->pstart_time = GNUNET_TIME_absolute_get ();
      return;
    }
  }
  rc->state = RC_READY;
  call_master (rc);
}


/**
 * Task to register all hosts available in the global host list
 *
 * @param cls the RunContext
 */
static void
register_hosts (void *cls);


/**
 * Callback which will be called to after a host registration succeeded or failed
 *
 * @param cls the closure
 * @param emsg the error message; NULL if host registration is successful
 */
static void
host_registration_completion (void *cls, const char *emsg)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;

  rc->reg_handle = NULL;
  if (NULL != emsg)
  {
    LOG (GNUNET_ERROR_TYPE_WARNING,
         _ ("Host registration failed for a host. Error: %s\n"), emsg);
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  rc->register_hosts_task = GNUNET_SCHEDULER_add_now (&register_hosts,
                                                      rc);
}


/**
 * Task to register all hosts available in the global host list
 *
 * @param cls RunContext
 */
static void
register_hosts (void *cls)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;
  struct RunContextOperation *rcop;
  unsigned int slave;

  rc->register_hosts_task = NULL;
  if (rc->reg_hosts == rc->num_hosts)
  {
    DEBUG ("All hosts successfully registered\n");
    /* Start slaves */
    for (slave = 0; slave < rc->num_hosts; slave++)
    {
      rcop = GNUNET_new (struct RunContextOperation);
      rcop->rc = rc;
      rcop->op =
        GNUNET_TESTBED_controller_link (rcop, rc->c, rc->hosts[slave],
                                        rc->h, GNUNET_YES);
      GNUNET_assert (NULL != rcop->op);
      insert_rcop (rc, rcop);
    }
    rc->reg_hosts = 0;
    return;
  }
  rc->reg_handle =
    GNUNET_TESTBED_register_host (rc->c, rc->hosts[rc->reg_hosts],
                                  host_registration_completion, rc);
  rc->reg_hosts++;
}


/**
 * Callback to signal successfull startup of the controller process
 *
 * @param cls the closure from GNUNET_TESTBED_controller_start()
 * @param cfg the configuration with which the controller has been started;
 *          NULL if status is not GNUNET_OK
 * @param status GNUNET_OK if the startup is successfull; GNUNET_SYSERR if not,
 *          GNUNET_TESTBED_controller_stop() shouldn't be called in this case
 */
static void
controller_status_cb (void *cls, const struct GNUNET_CONFIGURATION_Handle *cfg,
                      int status)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;
  uint64_t event_mask;

  if (status != GNUNET_OK)
  {
    rc->cproc = NULL;
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _ ("Controller crash detected. Shutting down.\n"));
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  GNUNET_CONFIGURATION_destroy (rc->cfg);
  rc->cfg = GNUNET_CONFIGURATION_dup (cfg);
  event_mask = rc->event_mask;
  event_mask |= (1LL << GNUNET_TESTBED_ET_OPERATION_FINISHED);
  event_mask |= (1LL << GNUNET_TESTBED_ET_PEER_START);
  if (rc->topology < GNUNET_TESTBED_TOPOLOGY_NONE)
    event_mask |= GNUNET_TESTBED_ET_CONNECT;
  rc->c =
    GNUNET_TESTBED_controller_connect (rc->h, event_mask, &event_cb, rc);
  if (0 < rc->num_hosts)
  {
    rc->reg_hosts = 0;
    rc->register_hosts_task = GNUNET_SCHEDULER_add_now (&register_hosts, rc);
    return;
  }
  rc->state = RC_LINKED;
  create_peers (rc);
}


/**
 * Callback function invoked for each interface found.
 *
 * @param cls closure
 * @param name name of the interface (can be NULL for unknown)
 * @param isDefault is this presumably the default interface
 * @param addr address of this interface (can be NULL for unknown or unassigned)
 * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
 * @param netmask the network mask (can be NULL for unknown or unassigned))
 * @param addrlen length of the address
 * @return GNUNET_OK to continue iteration, GNUNET_SYSERR to abort
 */
static int
netint_proc (void *cls, const char *name, int isDefault,
             const struct sockaddr *addr, const struct sockaddr *broadcast_addr,
             const struct sockaddr *netmask, socklen_t addrlen)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;
  char hostip[NI_MAXHOST];
  char *buf;

  if (sizeof(struct sockaddr_in) != addrlen)
    return GNUNET_OK;           /* Only consider IPv4 for now */
  if (0 !=
      getnameinfo (addr, addrlen, hostip, NI_MAXHOST, NULL, 0, NI_NUMERICHOST))
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "getnameinfo");
  if (NULL == rc->trusted_ip)
  {
    rc->trusted_ip = GNUNET_strdup (hostip);
    return GNUNET_YES;
  }
  (void) GNUNET_asprintf (&buf, "%s; %s", rc->trusted_ip, hostip);
  GNUNET_free (rc->trusted_ip);
  rc->trusted_ip = buf;
  return GNUNET_YES;
}


/**
 * Callbacks of this type are called by GNUNET_TESTBED_is_host_habitable to
 * inform whether the given host is habitable or not. The Handle returned by
 * GNUNET_TESTBED_is_host_habitable() is invalid after this callback is called
 *
 * @param cls NULL
 * @param host the host whose status is being reported; will be NULL if the host
 *          given to GNUNET_TESTBED_is_host_habitable() is NULL
 * @param status GNUNET_YES if it is habitable; GNUNET_NO if not
 */
static void
host_habitable_cb (void *cls, const struct GNUNET_TESTBED_Host *host,
                   int status)
{
  struct CompatibilityCheckContext *hc = cls;
  struct GNUNET_TESTBED_RunHandle *rc;
  struct GNUNET_TESTBED_Host **old_hosts;
  unsigned int nhost;

  GNUNET_assert (NULL != (rc = hc->rc));
  nhost = hc->index;
  GNUNET_assert (nhost <= rc->num_hosts);
  GNUNET_assert (host == rc->hosts[nhost]);
  hc->h = NULL;
  if (GNUNET_NO == status)
  {
    if ((NULL != host) && (NULL != GNUNET_TESTBED_host_get_hostname (host)))
      LOG (GNUNET_ERROR_TYPE_ERROR, _ ("Host %s cannot start testbed\n"),
           GNUNET_TESTBED_host_get_hostname (host));
    else
      LOG (GNUNET_ERROR_TYPE_ERROR,
           _ ("Testbed cannot be started on localhost\n"));
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  rc->reg_hosts++;
  if (rc->reg_hosts < rc->num_hosts)
    return;
  GNUNET_free (rc->hclist);
  rc->hclist = NULL;
  rc->h = rc->hosts[0];
  rc->num_hosts--;
  if (0 < rc->num_hosts)
  {
    old_hosts = rc->hosts;
    rc->hosts =
      GNUNET_malloc (sizeof(struct GNUNET_TESTBED_Host *) * rc->num_hosts);
    GNUNET_memcpy (rc->hosts, &old_hosts[1],
                   (sizeof(struct GNUNET_TESTBED_Host *) * rc->num_hosts));
    GNUNET_free (old_hosts);
  }
  else
  {
    GNUNET_free (rc->hosts);
    rc->hosts = NULL;
  }
  GNUNET_TESTBED_host_resolve_ (rc->h);
  for (nhost = 0; nhost < rc->num_hosts; nhost++)
    GNUNET_TESTBED_host_resolve_ (rc->hosts[nhost]);
  GNUNET_OS_network_interfaces_list (netint_proc, rc);
  if (NULL == rc->trusted_ip)
    rc->trusted_ip = GNUNET_strdup ("127.0.0.1");
  rc->cproc =
    GNUNET_TESTBED_controller_start (rc->trusted_ip, rc->h,
                                     &controller_status_cb, rc);
  GNUNET_free (rc->trusted_ip);
  rc->trusted_ip = NULL;
  if (NULL == rc->cproc)
  {
    LOG (GNUNET_ERROR_TYPE_ERROR, _ ("Cannot start the master controller"));
    GNUNET_SCHEDULER_shutdown ();
  }
}


/**
 * Task run upon timeout while setting up the testbed
 *
 * @param cls the RunContext
 */
static void
timeout_task (void *cls)
{
  struct GNUNET_TESTBED_RunHandle *rc = cls;

  rc->timeout_task = NULL;
  LOG (GNUNET_ERROR_TYPE_ERROR,
       _ ("Shutting down testbed due to timeout while setup.\n"));
  GNUNET_SCHEDULER_shutdown ();
  if (NULL != rc->test_master)
    rc->test_master (rc->test_master_cls, rc, 0, NULL, 0, 0);
  rc->test_master = NULL;
}


/**
 * Convenience method for running a testbed with
 * a single call.  Underlay and overlay topology
 * are configured using the "UNDERLAY" and "OVERLAY"
 * options in the "[testbed]" section of the configuration\
 * (with possible options given in "UNDERLAY_XXX" and/or
 * "OVERLAY_XXX").
 *
 * The testbed is to be terminated using a call to
 * "GNUNET_SCHEDULER_shutdown".
 *
 * @param host_filename name of the file with the 'hosts', NULL
 *        to run everything on 'localhost'
 * @param cfg configuration to use (for testbed, controller and peers)
 * @param num_peers number of peers to start; FIXME: maybe put that ALSO into cfg?
 * @param event_mask bit mask with set of events to call 'cc' for;
 *                   or-ed values of "1LL" shifted by the
 *                   respective 'enum GNUNET_TESTBED_EventType'
 *                   (i.e.  "(1LL << GNUNET_TESTBED_ET_CONNECT) || ...")
 * @param cc controller callback to invoke on events; This callback is called
 *          for all peer start events even if GNUNET_TESTBED_ET_PEER_START isn't
 *          set in the event_mask as this is the only way get access to the
 *          handle of each peer
 * @param cc_cls closure for cc
 * @param test_master this callback will be called once the test is ready
 * @param test_master_cls closure for 'test_master'.
 */
void
GNUNET_TESTBED_run (const char *host_filename,
                    const struct GNUNET_CONFIGURATION_Handle *cfg,
                    unsigned int num_peers, uint64_t event_mask,
                    GNUNET_TESTBED_ControllerCallback cc, void *cc_cls,
                    GNUNET_TESTBED_TestMaster test_master,
                    void *test_master_cls)
{
  struct GNUNET_TESTBED_RunHandle *rc;
  char *topology;
  struct CompatibilityCheckContext *hc;
  struct GNUNET_TIME_Relative timeout;
  unsigned long long number;
  unsigned int hid;
  unsigned int nhost;

  GNUNET_assert (num_peers > 0);
  rc = GNUNET_new (struct GNUNET_TESTBED_RunHandle);
  rc->cfg = GNUNET_CONFIGURATION_dup (cfg);
#if ENABLE_SUPERMUC
  rc->num_hosts = GNUNET_TESTBED_hosts_load_from_loadleveler (rc->cfg,
                                                              &rc->hosts);
  if (0 == rc->num_hosts)
  {
    LOG (GNUNET_ERROR_TYPE_WARNING,
         _ ("No hosts loaded from LoadLeveler. Need at least one host\n"));
    goto error_cleanup;
  }
#else
  if (NULL != host_filename)
  {
    rc->num_hosts =
      GNUNET_TESTBED_hosts_load_from_file (host_filename, rc->cfg,
                                           &rc->hosts);
    if (0 == rc->num_hosts)
    {
      LOG (GNUNET_ERROR_TYPE_WARNING,
           _ ("No hosts loaded. Need at least one host\n"));
      goto error_cleanup;
    }
  }
  else
    rc->h = GNUNET_TESTBED_host_create (NULL, NULL, rc->cfg, 0);
#endif
  rc->num_peers = num_peers;
  rc->event_mask = event_mask;
  rc->cc = cc;
  rc->cc_cls = cc_cls;
  rc->test_master = test_master;
  rc->test_master_cls = test_master_cls;
  rc->state = RC_INIT;
  rc->topology = GNUNET_TESTBED_TOPOLOGY_NONE;
  if (GNUNET_OK ==
      GNUNET_CONFIGURATION_get_value_string (rc->cfg, TESTBED_CONFIG_SECTION,
                                             "OVERLAY_TOPOLOGY", &topology))
  {
    if (GNUNET_NO == GNUNET_TESTBED_topology_get_ (&rc->topology, topology))
    {
      GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
                                 TESTBED_CONFIG_SECTION,
                                 "OVERLAY_TOPLOGY",
                                 _
                                 (
                                   "Specified topology must be supported by testbed"));
    }
    GNUNET_free (topology);
  }
  switch (rc->topology)
  {
  case GNUNET_TESTBED_TOPOLOGY_ERDOS_RENYI:
  case GNUNET_TESTBED_TOPOLOGY_SMALL_WORLD_RING:
  case GNUNET_TESTBED_TOPOLOGY_SMALL_WORLD:
    if (GNUNET_OK !=
        GNUNET_CONFIGURATION_get_value_number (rc->cfg, TESTBED_CONFIG_SECTION,
                                               "OVERLAY_RANDOM_LINKS",
                                               &number))
    {
      /* OVERLAY option RANDOM & SMALL_WORLD_RING requires OVERLAY_RANDOM_LINKS
       * option to be set to the number of random links to be established  */
      GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
                                 TESTBED_CONFIG_SECTION,
                                 "OVERLAY_RANDOM_LINKS");
      goto error_cleanup;
    }
    if (number > UINT32_MAX)
    {
      GNUNET_break (0);         /* Too big number */
      goto error_cleanup;
    }
    rc->random_links = (unsigned int) number;
    break;

  case GNUNET_TESTBED_TOPOLOGY_FROM_FILE:
    if (GNUNET_OK !=
        GNUNET_CONFIGURATION_get_value_filename (rc->cfg,
                                                 TESTBED_CONFIG_SECTION,
                                                 "OVERLAY_TOPOLOGY_FILE",
                                                 &rc->topo_file))
    {
      GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
                                 TESTBED_CONFIG_SECTION,
                                 "OVERLAY_TOPOLOGY_FILE");
      goto error_cleanup;
    }
    goto warn_ignore;

  case GNUNET_TESTBED_TOPOLOGY_SCALE_FREE:
    if (GNUNET_OK !=
        GNUNET_CONFIGURATION_get_value_number (rc->cfg, TESTBED_CONFIG_SECTION,
                                               SCALE_FREE_CAP, &number))
    {
      GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
                                 TESTBED_CONFIG_SECTION,
                                 SCALE_FREE_CAP);
      goto error_cleanup;
    }
    if (UINT16_MAX < number)
    {
      LOG (GNUNET_ERROR_TYPE_ERROR,
           _ ("Maximum number of edges a peer can have in a scale free topology"
              " cannot be more than %u.  Given `%s = %llu'"), UINT16_MAX,
           SCALE_FREE_CAP, number);
      goto error_cleanup;
    }
    if (GNUNET_OK !=
        GNUNET_CONFIGURATION_get_value_number (rc->cfg, TESTBED_CONFIG_SECTION,
                                               SCALE_FREE_M, &number))
    {
      GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
                                 TESTBED_CONFIG_SECTION,
                                 SCALE_FREE_M);
      goto error_cleanup;
    }
    if (UINT8_MAX < number)
    {
      LOG (GNUNET_ERROR_TYPE_ERROR,
           _ ("The number of edges that can established when adding a new node"
              " to scale free topology cannot be more than %u.  Given `%s = %llu'"),
           UINT8_MAX, SCALE_FREE_M, number);
      goto error_cleanup;
    }
    goto warn_ignore;

  case GNUNET_TESTBED_TOPOLOGY_OPTION_END:
    /* not allowed! */
    GNUNET_assert (0);

  default:
warn_ignore:
    /* Warn if OVERLAY_RANDOM_LINKS is present that it will be ignored */
    if (GNUNET_YES ==
        GNUNET_CONFIGURATION_have_value (rc->cfg, TESTBED_CONFIG_SECTION,
                                         "OVERLAY_RANDOM_LINKS"))
      LOG (GNUNET_ERROR_TYPE_WARNING,
           "Ignoring value of `OVERLAY_RANDOM_LINKS' in given configuration\n");
    break;
  }
  if (0 != rc->num_hosts)
  {
    rc->hclist = GNUNET_malloc (sizeof(struct CompatibilityCheckContext)
                                * rc->num_hosts);
    for (nhost = 0; nhost < rc->num_hosts; nhost++)
    {
      hc = &rc->hclist[nhost];
      hc->index = nhost;
      hc->rc = rc;
      hc->h = GNUNET_TESTBED_is_host_habitable (rc->hosts[nhost], rc->cfg,
                                                &host_habitable_cb, hc);
      if (NULL == hc->h)
      {
        GNUNET_break (0);
        for (nhost = 0; nhost < rc->num_hosts; nhost++)
        {
          hc = &rc->hclist[nhost];
          if (NULL != hc->h)
            GNUNET_TESTBED_is_host_habitable_cancel (hc->h);
        }
        GNUNET_free (rc->hclist);
        rc->hclist = NULL;
        goto error_cleanup;
      }
    }
  }
  else
    rc->cproc =
      GNUNET_TESTBED_controller_start ("127.0.0.1", rc->h,
                                       &controller_status_cb, rc);
  if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_time (cfg,
                                                        TESTBED_CONFIG_SECTION,
                                                        "SETUP_TIMEOUT",
                                                        &timeout))
  {
    timeout = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
                                             DEFAULT_SETUP_TIMEOUT);
  }
  rc->rcop_map = GNUNET_CONTAINER_multihashmap32_create (256);
  rc->timeout_task =
    GNUNET_SCHEDULER_add_delayed (timeout, &timeout_task, rc);
  GNUNET_assert (NULL == rc->interrupt_task);
  rc->interrupt_task =
    GNUNET_SCHEDULER_add_shutdown (&interrupt,
                                   rc);
  return;

error_cleanup:
  if (NULL != rc->h)
    GNUNET_TESTBED_host_destroy (rc->h);
  if (NULL != rc->hosts)
  {
    for (hid = 0; hid < rc->num_hosts; hid++)
      if (NULL != rc->hosts[hid])
        GNUNET_TESTBED_host_destroy (rc->hosts[hid]);
    GNUNET_free (rc->hosts);
  }
  if (NULL != rc->cfg)
    GNUNET_CONFIGURATION_destroy (rc->cfg);
  GNUNET_free (rc);
}


/**
 * Obtain handle to the master controller from a testbed run.  The handle
 * returned should not be disconnected.
 *
 * @param h the testbed run handle
 * @return handle to the master controller
 */
struct GNUNET_TESTBED_Controller *
GNUNET_TESTBED_run_get_controller_handle (struct GNUNET_TESTBED_RunHandle *h)
{
  return h->c;
}


/* end of testbed_api_testbed.c */