gnunet/src/testing/testing.c

/*
      This file is part of GNUnet
      Copyright (C) 2008, 2009, 2012 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 testing/testing.c
 * @brief convenience API for writing testcases for GNUnet
 *        Many testcases need to start and stop a peer/service
 *        and this library is supposed to make that easier
 *        for TESTCASES.  Normal programs should always
 *        use functions from gnunet_{util,arm}_lib.h.  This API is
 *        ONLY for writing testcases (or internal use of the testbed).
 * @author Christian Grothoff
 *
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_arm_service.h"
#include "gnunet_testing_lib.h"

#define LOG(kind,...)                                           \
  GNUNET_log_from (kind, "testing-api", __VA_ARGS__)


/**
 * We need pipe control only on WINDOWS
 */
#if WINDOWS
#define PIPE_CONTROL GNUNET_YES
#else
#define PIPE_CONTROL GNUNET_NO
#endif


/**
 * Lowest port used for GNUnet testing.  Should be high enough to not
 * conflict with other applications running on the hosts but be low
 * enough to not conflict with client-ports (typically starting around
 * 32k).
 */
#define LOW_PORT 12000

/**
 * Highest port used for GNUnet testing.  Should be low enough to not
 * conflict with the port range for "local" ports (client apps; see
 * /proc/sys/net/ipv4/ip_local_port_range on Linux for example).
 */
#define HIGH_PORT 56000


struct SharedServiceInstance
{
  struct SharedService *ss;

  char *cfg_fn;

  struct GNUNET_OS_Process *proc;

  char *unix_sock;

  char *port_str;

  unsigned int n_refs;
};

struct SharedService
{
  char *sname;

  struct SharedServiceInstance **instances;

  struct GNUNET_CONFIGURATION_Handle *cfg;

  unsigned int n_peers;

  unsigned int share;

  unsigned int n_instances;
};


/**
 * Handle for a system on which GNUnet peers are executed;
 * a system is used for reserving unique paths and ports.
 */
struct GNUNET_TESTING_System
{
  /**
   * Prefix (i.e. "/tmp/gnunet-testing/") we prepend to each
   * GNUNET_HOME.
   */
  char *tmppath;

  /**
   * The trusted ip. Can either be a single ip address or a network address in
   * CIDR notation.
   */
  char *trusted_ip;

  /**
   * our hostname
   */
  char *hostname;

  /**
   * Hostkeys data, contains "GNUNET_TESTING_HOSTKEYFILESIZE * total_hostkeys" bytes.
   */
  char *hostkeys_data;

  /**
   * memory map for @e hostkeys_data.
   */
  struct GNUNET_DISK_MapHandle *map;

  struct SharedService **shared_services;

  unsigned int n_shared_services;

  /**
   * Bitmap where each port that has already been reserved for some GNUnet peer
   * is recorded.  Note that we make no distinction between TCP and UDP ports
   * and test if a port is already in use before assigning it to a peer/service.
   * If we detect that a port is already in use, we also mark it in this bitmap.
   * So all the bits that are zero merely indicate ports that MIGHT be available
   * for peers.
   */
  uint32_t reserved_ports[65536 / 32];

  /**
   * Counter we use to make service home paths unique on this system;
   * the full path consists of the tmppath and this number.  Each
   * UNIXPATH for a peer is also modified to include the respective
   * path counter to ensure uniqueness.  This field is incremented
   * by one for each configured peer.  Even if peers are destroyed,
   * we never re-use path counters.
   */
  uint32_t path_counter;

  /**
   * The number of hostkeys
   */
  uint32_t total_hostkeys;

  /**
   * Lowest port we are allowed to use.
   */
  uint16_t lowport;

  /**
   * Highest port we are allowed to use.
   */
  uint16_t highport;
};


/**
 * Handle for a GNUnet peer controlled by testing.
 */
struct GNUNET_TESTING_Peer
{
  /**
   * The TESTING system associated with this peer
   */
  struct GNUNET_TESTING_System *system;

  /**
   * Path to the configuration file for this peer.
   */
  char *cfgfile;

  /**
   * Binary to be executed during 'GNUNET_TESTING_peer_start'.
   * Typically 'gnunet-service-arm' (but can be set to a
   * specific service by 'GNUNET_TESTING_service_run' if
   * necessary).
   */
  char *main_binary;
  char *args;

  /**
   * Handle to the running binary of the service, NULL if the
   * peer/service is currently not running.
   */
  struct GNUNET_OS_Process *main_process;

  /**
   * The handle to the peer's ARM service
   */
  struct GNUNET_ARM_Handle *ah;

  /**
   * The config of the peer
   */
  struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * The callback to call asynchronously when a peer is stopped
   */
  GNUNET_TESTING_PeerStopCallback cb;

  /**
   * The closure for the above callback
   */
  void *cb_cls;

  /**
   * The cached identity of this peer.  Will be populated on call to
   * GNUNET_TESTING_peer_get_identity()
   */
  struct GNUNET_PeerIdentity *id;

  struct SharedServiceInstance **ss_instances;

  /**
   * Array of ports currently allocated to this peer.  These ports will be
   * released upon peer destroy and can be used by other peers which are
   * configured after.
   */
  uint16_t *ports;

  /**
   * The number of ports in the above array
   */
  unsigned int nports;

  /**
   * The keynumber of this peer's hostkey
   */
  uint32_t key_number;
};


/**
 * Testing includes a number of pre-created hostkeys for faster peer
 * startup. This function loads such keys into memory from a file.
 *
 * @param system the testing system handle
 * @return #GNUNET_OK on success; #GNUNET_SYSERR on error
 */
static int
hostkeys_load (struct GNUNET_TESTING_System *system)
{
  uint64_t fs;
  char *data_dir;
  char *filename;
  struct GNUNET_DISK_FileHandle *fd;

  GNUNET_assert (NULL == system->hostkeys_data);
  data_dir = GNUNET_OS_installation_get_path (GNUNET_OS_IPK_DATADIR);
  GNUNET_asprintf (&filename, "%s/testing_hostkeys.ecc", data_dir);
  GNUNET_free (data_dir);

  if (GNUNET_YES != GNUNET_DISK_file_test (filename))
  {
    LOG (GNUNET_ERROR_TYPE_ERROR,
         _("Hostkeys file not found: %s\n"), filename);
    GNUNET_free (filename);
    return GNUNET_SYSERR;
  }
  /* Check hostkey file size, read entire thing into memory */
  if (GNUNET_OK !=
      GNUNET_DISK_file_size (filename, &fs, GNUNET_YES, GNUNET_YES))
    fs = 0;
  if (0 == fs)
  {
    GNUNET_free (filename);
    return GNUNET_SYSERR;       /* File is empty */
  }
  if (0 != (fs % GNUNET_TESTING_HOSTKEYFILESIZE))
  {
    LOG (GNUNET_ERROR_TYPE_ERROR,
         _("Incorrect hostkey file format: %s\n"), filename);
    GNUNET_free (filename);
    return GNUNET_SYSERR;
  }
  fd = GNUNET_DISK_file_open (filename, GNUNET_DISK_OPEN_READ,
					 GNUNET_DISK_PERM_NONE);
  if (NULL == fd)
  {
    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR, "open", filename);
    GNUNET_free (filename);
    return GNUNET_SYSERR;
  }
  GNUNET_free (filename);
  system->hostkeys_data = GNUNET_DISK_file_map (fd,
						&system->map,
						GNUNET_DISK_MAP_TYPE_READ,
						fs);
  GNUNET_DISK_file_close (fd);
  if (NULL == system->hostkeys_data)
    return GNUNET_SYSERR;
  system->total_hostkeys = fs / GNUNET_TESTING_HOSTKEYFILESIZE;
  return GNUNET_OK;
}


/**
 * Function to remove the loaded hostkeys
 *
 * @param system the testing system handle
 */
static void
hostkeys_unload (struct GNUNET_TESTING_System *system)
{
  GNUNET_break (NULL != system->hostkeys_data);
  system->hostkeys_data = NULL;
  GNUNET_DISK_file_unmap (system->map);
  system->map = NULL;
  system->hostkeys_data = NULL;
  system->total_hostkeys = 0;
}


/**
 * Function to iterate over options.
 *
 * @param cls closure
 * @param section name of the section
 * @param option name of the option
 * @param value value of the option
 */
static void
cfg_copy_iterator (void *cls, const char *section,
                   const char *option, const char *value)
{
  struct GNUNET_CONFIGURATION_Handle *cfg2 = cls;

  GNUNET_CONFIGURATION_set_value_string (cfg2, section, option, value);
}


/**
 * Create a system handle.  There must only be one system
 * handle per operating system.
 *
 * @param testdir only the directory name without any path. This is used for
 *          all service homes; the directory will be created in a temporary
 *          location depending on the underlying OS.  This variable will be
 *          overridden with the value of the environmental variable
 *          GNUNET_TESTING_PREFIX, if it exists.
 * @param trusted_ip the ip address which will be set as TRUSTED HOST in all
 *          service configurations generated to allow control connections from
 *          this ip. This can either be a single ip address or a network address
 *          in CIDR notation.
 * @param hostname the hostname of the system we are using for testing; NULL for
 *          localhost
 * @param shared_services NULL terminated array describing services that are to
 *          be shared among peers
 * @param lowport lowest port number this system is allowed to allocate (inclusive)
 * @param highport highest port number this system is allowed to allocate (exclusive)
 * @return handle to this system, NULL on error
 */
struct GNUNET_TESTING_System *
GNUNET_TESTING_system_create_with_portrange (const char *testdir,
					     const char *trusted_ip,
					     const char *hostname,
                                             const struct
                                             GNUNET_TESTING_SharedService *
                                             shared_services,
					     uint16_t lowport,
					     uint16_t highport)
{
  struct GNUNET_TESTING_System *system;
  struct GNUNET_TESTING_SharedService tss;
  struct SharedService *ss;
  unsigned int cnt;

  GNUNET_assert (NULL != testdir);
  system = GNUNET_new (struct GNUNET_TESTING_System);
  if (NULL == (system->tmppath = getenv (GNUNET_TESTING_PREFIX)))
    system->tmppath = GNUNET_DISK_mkdtemp (testdir);
  else
    system->tmppath = GNUNET_strdup (system->tmppath);
  system->lowport = lowport;
  system->highport = highport;
  if (NULL == system->tmppath)
  {
    GNUNET_free (system);
    return NULL;
  }
  if (NULL != trusted_ip)
    system->trusted_ip = GNUNET_strdup (trusted_ip);
  if (NULL != hostname)
    system->hostname = GNUNET_strdup (hostname);
  if (GNUNET_OK != hostkeys_load (system))
  {
    GNUNET_TESTING_system_destroy (system, GNUNET_YES);
    return NULL;
  }
  if (NULL == shared_services)
    return system;
  for (cnt = 0; NULL != shared_services[cnt].service; cnt++)
  {
    tss = shared_services[cnt];
    ss = GNUNET_new (struct SharedService);
    ss->sname = GNUNET_strdup (tss.service);
    ss->cfg = GNUNET_CONFIGURATION_create ();
    GNUNET_CONFIGURATION_iterate_section_values (tss.cfg, ss->sname,
                                                 &cfg_copy_iterator, ss->cfg);
    GNUNET_CONFIGURATION_iterate_section_values (tss.cfg, "TESTING",
                                                 &cfg_copy_iterator, ss->cfg);
    GNUNET_CONFIGURATION_iterate_section_values (tss.cfg, "PATHS",
                                                 &cfg_copy_iterator, ss->cfg);
    ss->share = tss.share;
    GNUNET_array_append (system->shared_services, system->n_shared_services,
                         ss);
  }
  return system;
}


/**
 * Create a system handle.  There must only be one system handle per operating
 * system.  Uses a default range for allowed ports.  Ports are still tested for
 * availability.
 *
 * @param testdir only the directory name without any path. This is used for all
 *          service homes; the directory will be created in a temporary location
 *          depending on the underlying OS.  This variable will be
 *          overridden with the value of the environmental variable
 *          GNUNET_TESTING_PREFIX, if it exists.
 * @param trusted_ip the ip address which will be set as TRUSTED HOST in all
 *          service configurations generated to allow control connections from
 *          this ip. This can either be a single ip address or a network address
 *          in CIDR notation.
 * @param hostname the hostname of the system we are using for testing; NULL for
 *          localhost
 * @param shared_services NULL terminated array describing services that are to
 *          be shared among peers
 * @return handle to this system, NULL on error
 */
struct GNUNET_TESTING_System *
GNUNET_TESTING_system_create (const char *testdir,
			      const char *trusted_ip,
			      const char *hostname,
                              const struct GNUNET_TESTING_SharedService *
                              shared_services)
{
  return GNUNET_TESTING_system_create_with_portrange (testdir,
						      trusted_ip,
						      hostname,
                                                      shared_services,
						      LOW_PORT,
						      HIGH_PORT);
}


static void
cleanup_shared_service_instance (struct SharedServiceInstance *i)
{
  if (NULL != i->cfg_fn)
  {
    (void) unlink (i->cfg_fn);
    GNUNET_free (i->cfg_fn);
  }
  GNUNET_free_non_null (i->unix_sock);
  GNUNET_free_non_null (i->port_str);
  GNUNET_break (NULL == i->proc);
  GNUNET_break (0 == i->n_refs);
  GNUNET_free (i);
}


static int
start_shared_service_instance (struct SharedServiceInstance *i)
{
  char *binary;
  char *libexec_binary;

  GNUNET_assert (NULL == i->proc);
  GNUNET_assert (NULL != i->cfg_fn);
  (void) GNUNET_asprintf (&binary, "gnunet-service-%s", i->ss->sname);
  libexec_binary = GNUNET_OS_get_libexec_binary_path (binary);
  GNUNET_free (binary);
  i->proc = GNUNET_OS_start_process (PIPE_CONTROL,
                                     GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
                                     NULL, NULL, NULL,
                                     libexec_binary,
                                     libexec_binary,
                                     "-c",
                                     i->cfg_fn,
                                     NULL);
  GNUNET_free (libexec_binary);
  if (NULL == i->proc)
    return GNUNET_SYSERR;
  return GNUNET_OK;
}


static void
stop_shared_service_instance (struct SharedServiceInstance *i)
{
  GNUNET_break (0 == i->n_refs);
  if (0 != GNUNET_OS_process_kill (i->proc, GNUNET_TERM_SIG))
    LOG (GNUNET_ERROR_TYPE_WARNING,
         "Killing shared service instance (%s) failed\n", i->ss->sname);
  (void) GNUNET_OS_process_wait (i->proc);
  GNUNET_OS_process_destroy (i->proc);
  i->proc = NULL;
}


/**
 * Free system resources.
 *
 * @param system system to be freed
 * @param remove_paths should the 'testdir' and all subdirectories
 *        be removed (clean up on shutdown)?
 */
void
GNUNET_TESTING_system_destroy (struct GNUNET_TESTING_System *system,
			       int remove_paths)
{
  struct SharedService *ss;
  struct SharedServiceInstance *i;
  unsigned int ss_cnt;
  unsigned int i_cnt;

  if (NULL != system->hostkeys_data)
    hostkeys_unload (system);
  for (ss_cnt = 0; ss_cnt < system->n_shared_services; ss_cnt++)
  {
    ss = system->shared_services[ss_cnt];
    for (i_cnt = 0; i_cnt < ss->n_instances; i_cnt++)
    {
      i = ss->instances[i_cnt];
      if (NULL != i->proc)
        stop_shared_service_instance (i);
      cleanup_shared_service_instance (i);
    }
    GNUNET_free_non_null (ss->instances);
    GNUNET_CONFIGURATION_destroy (ss->cfg);
    GNUNET_free (ss->sname);
    GNUNET_free (ss);
  }
  GNUNET_free_non_null (system->shared_services);
  if (GNUNET_YES == remove_paths)
    GNUNET_DISK_directory_remove (system->tmppath);
  GNUNET_free (system->tmppath);
  GNUNET_free_non_null (system->trusted_ip);
  GNUNET_free_non_null (system->hostname);
  GNUNET_free (system);
}


/**
 * Reserve a TCP or UDP port for a peer.
 *
 * @param system system to use for reservation tracking
 * @return 0 if no free port was available
 */
uint16_t
GNUNET_TESTING_reserve_port (struct GNUNET_TESTING_System *system)
{
  struct GNUNET_NETWORK_Handle *socket;
  struct addrinfo hint;
  struct addrinfo *ret;
  struct addrinfo *ai;
  uint32_t *port_buckets;
  char *open_port_str;
  int bind_status;
  uint32_t xor_image;
  uint16_t index;
  uint16_t open_port;
  uint16_t pos;

  /*
  FIXME: Instead of using getaddrinfo we should try to determine the port
         status by the following heurestics.

	 On systems which support both IPv4 and IPv6, only ports open on both
	 address families are considered open.
	 On system with either IPv4 or IPv6. A port is considered open if it's
	 open in the respective address family
  */
  hint.ai_family = AF_UNSPEC;	/* IPv4 and IPv6 */
  hint.ai_socktype = 0;
  hint.ai_protocol = 0;
  hint.ai_addrlen = 0;
  hint.ai_addr = NULL;
  hint.ai_canonname = NULL;
  hint.ai_next = NULL;
  hint.ai_flags = AI_PASSIVE | AI_NUMERICSERV;	/* Wild card address */
  port_buckets = system->reserved_ports;
  for (index = (system->lowport / 32) + 1; index < (system->highport / 32); index++)
  {
    xor_image = (UINT32_MAX ^ port_buckets[index]);
    if (0 == xor_image)        /* Ports in the bucket are full */
      continue;
    pos = system->lowport % 32;
    while (pos < 32)
    {
      if (0 == ((xor_image >> pos) & 1U))
      {
        pos++;
        continue;
      }
      open_port = (index * 32) + pos;
      if (open_port >= system->highport)
	return 0;
      GNUNET_asprintf (&open_port_str, "%u", (unsigned int) open_port);
      ret = NULL;
      GNUNET_assert (0 == getaddrinfo (NULL, open_port_str, &hint, &ret));
      GNUNET_free (open_port_str);
      bind_status = GNUNET_NO;
      for (ai = ret; NULL != ai; ai = ai->ai_next)
      {
        socket = GNUNET_NETWORK_socket_create (ai->ai_family, SOCK_STREAM, 0);
        if (NULL == socket)
          continue;
        bind_status = GNUNET_NETWORK_socket_bind (socket,
                                                  ai->ai_addr,
                                                  ai->ai_addrlen);
        GNUNET_NETWORK_socket_close (socket);
        if (GNUNET_OK != bind_status)
          break;
        socket = GNUNET_NETWORK_socket_create (ai->ai_family, SOCK_DGRAM, 0);
        if (NULL == socket)
          continue;
        bind_status = GNUNET_NETWORK_socket_bind (socket,
                                                  ai->ai_addr,
                                                  ai->ai_addrlen);
        GNUNET_NETWORK_socket_close (socket);
        if (GNUNET_OK != bind_status)
          break;
      }
      port_buckets[index] |= (1U << pos); /* Set the port bit */
      freeaddrinfo (ret);
      if (GNUNET_OK == bind_status)
      {
        LOG (GNUNET_ERROR_TYPE_DEBUG,
             "Found a free port %u\n", (unsigned int) open_port);
	return open_port;
      }
      pos++;
    }
  }
  return 0;
}


/**
 * Release reservation of a TCP or UDP port for a peer
 * (used during #GNUNET_TESTING_peer_destroy()).
 *
 * @param system system to use for reservation tracking
 * @param port reserved port to release
 */
void
GNUNET_TESTING_release_port (struct GNUNET_TESTING_System *system,
			     uint16_t port)
{
  uint32_t *port_buckets;
  uint16_t bucket;
  uint16_t pos;

  port_buckets = system->reserved_ports;
  bucket = port / 32;
  pos = port % 32;
  LOG (GNUNET_ERROR_TYPE_DEBUG, "Releasing port %u\n", port);
  if (0 == (port_buckets[bucket] & (1U << pos)))
  {
    GNUNET_break(0); /* Port was not reserved by us using reserve_port() */
    return;
  }
  port_buckets[bucket] &= ~(1U << pos);
}


/**
 * Testing includes a number of pre-created hostkeys for
 * faster peer startup.  This function can be used to
 * access the n-th key of those pre-created hostkeys; note
 * that these keys are ONLY useful for testing and not
 * secure as the private keys are part of the public
 * GNUnet source code.
 *
 * This is primarily a helper function used internally
 * by #GNUNET_TESTING_peer_configure.
 *
 * @param system the testing system handle
 * @param key_number desired pre-created hostkey to obtain
 * @param id set to the peer's identity (hash of the public
 *        key; if NULL, NULL is returned immediately
 * @return NULL on error (not enough keys)
 */
struct GNUNET_CRYPTO_EddsaPrivateKey *
GNUNET_TESTING_hostkey_get (const struct GNUNET_TESTING_System *system,
			    uint32_t key_number,
			    struct GNUNET_PeerIdentity *id)
{
  struct GNUNET_CRYPTO_EddsaPrivateKey *private_key;

  if ((NULL == id) || (NULL == system->hostkeys_data))
    return NULL;
  if (key_number >= system->total_hostkeys)
  {
    LOG (GNUNET_ERROR_TYPE_ERROR,
         _("Key number %u does not exist\n"),
         key_number);
    return NULL;
  }
  private_key = GNUNET_new (struct GNUNET_CRYPTO_EddsaPrivateKey);
  GNUNET_memcpy (private_key,
	  system->hostkeys_data +
	  (key_number * GNUNET_TESTING_HOSTKEYFILESIZE),
	  GNUNET_TESTING_HOSTKEYFILESIZE);
  GNUNET_CRYPTO_eddsa_key_get_public (private_key,
                                      &id->public_key);
  return private_key;
}


/**
 * Structure for holding data to build new configurations from a configuration
 * template
 */
struct UpdateContext
{
  /**
   * The system for which we are building configurations
   */
  struct GNUNET_TESTING_System *system;

  /**
   * The configuration we are building
   */
  struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * The customized service home path for this peer
   */
  char *gnunet_home;

  /**
   * Array of ports currently allocated to this peer.  These ports will be
   * released upon peer destroy and can be used by other peers which are
   * configured after.
   */
  uint16_t *ports;

  /**
   * The number of ports in the above array
   */
  unsigned int nports;

  /**
   * build status - to signal error while building a configuration
   */
  int status;
};


/**
 * Function to iterate over options.  Copies
 * the options to the target configuration,
 * updating PORT values as needed.
 *
 * @param cls the UpdateContext
 * @param section name of the section
 * @param option name of the option
 * @param value value of the option
 */
static void
update_config (void *cls,
               const char *section,
               const char *option,
               const char *value)
{
  struct UpdateContext *uc = cls;
  unsigned int ival;
  char cval[12];
  char uval[PATH_MAX];
  char *single_variable;
  char *per_host_variable;
  unsigned long long num_per_host;
  uint16_t new_port;

  if (GNUNET_OK != uc->status)
    return;
  if (! ((0 == strcmp (option, "PORT"))
         || (0 == strcmp (option, "UNIXPATH"))
         || (0 == strcmp (option, "HOSTNAME"))))
    return;
  GNUNET_asprintf (&single_variable, "single_%s_per_host", section);
  GNUNET_asprintf (&per_host_variable, "num_%s_per_host", section);
  if ((0 == strcmp (option, "PORT")) && (1 == SSCANF (value, "%u", &ival)))
  {
    if ((ival != 0) &&
        (GNUNET_YES !=
         GNUNET_CONFIGURATION_get_value_yesno (uc->cfg, "testing",
                                               single_variable)))
    {
      new_port = GNUNET_TESTING_reserve_port (uc->system);
      if (0 == new_port)
      {
        uc->status = GNUNET_SYSERR;
        GNUNET_free (single_variable);
        GNUNET_free (per_host_variable);
        return;
      }
      GNUNET_snprintf (cval, sizeof (cval), "%u", new_port);
      value = cval;
      GNUNET_array_append (uc->ports, uc->nports, new_port);
    }
    else if ((ival != 0) &&
             (GNUNET_YES ==
              GNUNET_CONFIGURATION_get_value_yesno (uc->cfg, "testing",
                                                    single_variable)) &&
             GNUNET_CONFIGURATION_get_value_number (uc->cfg, "testing",
                                                    per_host_variable,
                                                    &num_per_host))
    {
      /* GNUNET_snprintf (cval, sizeof (cval), "%u", */
      /*                  ival + ctx->fdnum % num_per_host); */
      /* value = cval; */
      GNUNET_break (0);         /* FIXME */
    }
  }
  if (0 == strcmp (option, "UNIXPATH"))
  {
    if (GNUNET_YES !=
        GNUNET_CONFIGURATION_get_value_yesno (uc->cfg, "testing",
                                              single_variable))
    {
      GNUNET_snprintf (uval,
                       sizeof (uval),
                       "%s/%s.sock",
                       uc->gnunet_home, section);
      value = uval;
    }
    else if ((GNUNET_YES ==
              GNUNET_CONFIGURATION_get_value_number (uc->cfg, "testing",
                                                     per_host_variable,
                                                     &num_per_host)) &&
             (num_per_host > 0))
    {
      GNUNET_break(0);          /* FIXME */
    }
  }
  if (0 == strcmp (option, "HOSTNAME"))
  {
    value = (NULL == uc->system->hostname) ? "localhost" : uc->system->hostname;
  }
  GNUNET_free (single_variable);
  GNUNET_free (per_host_variable);
  GNUNET_CONFIGURATION_set_value_string (uc->cfg, section, option, value);
}


/**
 * Section iterator to set ACCEPT_FROM/ACCEPT_FROM6 to include the address of
 * 'trusted_hosts' in all sections
 *
 * @param cls the UpdateContext
 * @param section name of the section
 */
static void
update_config_sections (void *cls,
                        const char *section)
{
  struct UpdateContext *uc = cls;
  char **ikeys;
  char *val;
  char *ptr;
  char *orig_allowed_hosts;
  char *allowed_hosts;
  char *ACCEPT_FROM_key;
  uint16_t ikeys_cnt;
  uint16_t key;

  ikeys_cnt = 0;
  val = NULL;
  /* Ignore certain options from sections.  See
     https://gnunet.org/bugs/view.php?id=2476 */
  if (GNUNET_YES == GNUNET_CONFIGURATION_have_value (uc->cfg, section,
                                                     "TESTING_IGNORE_KEYS"))
  {
    GNUNET_assert
      (GNUNET_YES ==
       GNUNET_CONFIGURATION_get_value_string (uc->cfg, section,
                                              "TESTING_IGNORE_KEYS", &val));
    ptr = val;
    for (ikeys_cnt = 0; NULL != (ptr = strstr (ptr, ";")); ikeys_cnt++)
      ptr++;
    if (0 == ikeys_cnt)
      GNUNET_break (0);
    else
    {
      ikeys = GNUNET_malloc ((sizeof (char *)) * ikeys_cnt);
      ptr = val;
      for (key = 0; key < ikeys_cnt; key++)
      {
        ikeys[key] = ptr;
        ptr = strstr (ptr, ";");
        GNUNET_assert (NULL != ptr); /* worked just before... */
        *ptr = '\0';
        ptr++;
      }
    }
  }
  if (0 != ikeys_cnt)
  {
    for (key = 0; key < ikeys_cnt; key++)
    {
      if (NULL != strstr (ikeys[key], "ADVERTISED_PORT"))
	break;
    }
    if ((key == ikeys_cnt) &&
	(GNUNET_YES == GNUNET_CONFIGURATION_have_value (uc->cfg, section,
							"ADVERTISED_PORT")))
    {
      if (GNUNET_OK ==
	  GNUNET_CONFIGURATION_get_value_string (uc->cfg, section, "PORT", &ptr))
      {
	GNUNET_CONFIGURATION_set_value_string (uc->cfg, section,
					       "ADVERTISED_PORT", ptr);
	GNUNET_free (ptr);
      }
    }
    for (key = 0; key < ikeys_cnt; key++)
    {
      if (NULL != strstr (ikeys[key], "ACCEPT_FROM"))
      {
        GNUNET_free (ikeys);
        GNUNET_free (val);
        return;
      }
    }
    GNUNET_free (ikeys);
  }
  GNUNET_free_non_null (val);
  ACCEPT_FROM_key = "ACCEPT_FROM";
  if ((NULL != uc->system->trusted_ip) &&
      (NULL != strstr (uc->system->trusted_ip, ":"))) /* IPv6 in use */
    ACCEPT_FROM_key = "ACCEPT_FROM6";
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (uc->cfg, section, ACCEPT_FROM_key,
                                             &orig_allowed_hosts))
  {
    orig_allowed_hosts = GNUNET_strdup ("127.0.0.1;");
  }
  if (NULL == uc->system->trusted_ip)
    allowed_hosts = GNUNET_strdup (orig_allowed_hosts);
  else
    GNUNET_asprintf (&allowed_hosts, "%s%s;", orig_allowed_hosts,
                     uc->system->trusted_ip);
  GNUNET_free (orig_allowed_hosts);
  GNUNET_CONFIGURATION_set_value_string (uc->cfg, section, ACCEPT_FROM_key,
                                         allowed_hosts);
  GNUNET_free (allowed_hosts);
}


static struct SharedServiceInstance *
associate_shared_service (struct GNUNET_TESTING_System *system,
                          struct SharedService *ss,
                          struct GNUNET_CONFIGURATION_Handle *cfg)
{
  struct SharedServiceInstance *i;
  struct GNUNET_CONFIGURATION_Handle *temp;
  char *gnunet_home;
  uint32_t port;

  ss->n_peers++;
  if ( ((0 == ss->share) && (NULL == ss->instances))
       ||
       ( (0 != ss->share)
         && (ss->n_instances < ((ss->n_peers + ss->share - 1) / ss->share)) ) )
  {
    i = GNUNET_new (struct SharedServiceInstance);
    i->ss = ss;
    (void) GNUNET_asprintf (&gnunet_home, "%s/shared/%s/%u",
                            system->tmppath, ss->sname, ss->n_instances);
    (void) GNUNET_asprintf (&i->unix_sock, "%s/sock", gnunet_home);
    port = GNUNET_TESTING_reserve_port (system);
    if (0 == port)
    {
      GNUNET_free (gnunet_home);
      cleanup_shared_service_instance (i);
      return NULL;
    }
    GNUNET_array_append (ss->instances, ss->n_instances, i);
    temp = GNUNET_CONFIGURATION_dup (ss->cfg);
    (void) GNUNET_asprintf (&i->port_str, "%u", port);
    (void) GNUNET_asprintf (&i->cfg_fn, "%s/config", gnunet_home);
    GNUNET_CONFIGURATION_set_value_string (temp, "PATHS", "GNUNET_HOME",
                                           gnunet_home);
    GNUNET_free (gnunet_home);
    GNUNET_CONFIGURATION_set_value_string (temp, ss->sname, "UNIXPATH",
                                           i->unix_sock);
    GNUNET_CONFIGURATION_set_value_string (temp, ss->sname, "PORT",
                                           i->port_str);
    if (GNUNET_SYSERR == GNUNET_CONFIGURATION_write (temp, i->cfg_fn))
    {
      GNUNET_CONFIGURATION_destroy (temp);
      cleanup_shared_service_instance (i);
      return NULL;
    }
    GNUNET_CONFIGURATION_destroy (temp);
  }
  else
  {
    GNUNET_assert (NULL != ss->instances);
    GNUNET_assert (0 < ss->n_instances);
    i = ss->instances[ss->n_instances - 1];
  }
  GNUNET_CONFIGURATION_iterate_section_values(ss->cfg, ss->sname,
                                              &cfg_copy_iterator, cfg);
  GNUNET_CONFIGURATION_set_value_string (cfg, ss->sname, "UNIXPATH",
                                         i->unix_sock);
  GNUNET_CONFIGURATION_set_value_string (cfg, ss->sname, "PORT", i->port_str);
  return i;
}


/**
 * Create a new configuration using the given configuration as a template;
 * ports and paths will be modified to select available ports on the local
 * system. The default configuration will be available in PATHS section under
 * the option DEFAULTCONFIG after the call. GNUNET_HOME is also set in PATHS
 * section to the temporary directory specific to this configuration. If we run
 * out of "*port" numbers, return #GNUNET_SYSERR.
 *
 * This is primarily a helper function used internally
 * by 'GNUNET_TESTING_peer_configure'.
 *
 * @param system system to use to coordinate resource usage
 * @param cfg template configuration to update
 * @param ports array with port numbers used in the created configuration.
 *          Will be updated upon successful return.  Can be NULL
 * @param nports the size of the `ports' array.  Will be updated.
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error - the configuration will
 *           be incomplete and should not be used there upon
 */
static int
GNUNET_TESTING_configuration_create_ (struct GNUNET_TESTING_System *system,
                                      struct GNUNET_CONFIGURATION_Handle *cfg,
                                      uint16_t **ports,
                                      unsigned int *nports)
{
  struct UpdateContext uc;
  char *default_config;

  uc.system = system;
  uc.cfg = cfg;
  uc.status = GNUNET_OK;
  uc.ports = NULL;
  uc.nports = 0;
  GNUNET_asprintf (&uc.gnunet_home, "%s/%u", system->tmppath,
                   system->path_counter++);
  GNUNET_asprintf (&default_config, "%s/config", uc.gnunet_home);
  GNUNET_CONFIGURATION_set_value_string (cfg, "PATHS", "DEFAULTCONFIG",
                                         default_config);
  GNUNET_CONFIGURATION_set_value_string (cfg, "arm", "CONFIG",
                                         default_config);
  GNUNET_free (default_config);
  GNUNET_CONFIGURATION_set_value_string (cfg, "PATHS", "GNUNET_HOME",
                                         uc.gnunet_home);
  /* make PORTs and UNIXPATHs unique */
  GNUNET_CONFIGURATION_iterate (cfg, &update_config, &uc);
  /* allow connections to services from system trusted_ip host */
  GNUNET_CONFIGURATION_iterate_sections (cfg, &update_config_sections, &uc);
  /* enable loopback-based connections between peers */
  GNUNET_CONFIGURATION_set_value_string (cfg,
					 "nat",
					 "USE_LOCALADDR", "YES");
  GNUNET_free (uc.gnunet_home);
  if ((NULL != ports) && (NULL != nports))
  {
    *ports = uc.ports;
    *nports = uc.nports;
  }
  else
    GNUNET_free_non_null (uc.ports);
  return uc.status;
}


/**
 * Create a new configuration using the given configuration as a template;
 * ports and paths will be modified to select available ports on the local
 * system. The default configuration will be available in PATHS section under
 * the option DEFAULTCONFIG after the call. GNUNET_HOME is also set in PATHS
 * section to the temporary directory specific to this configuration. If we run
 * out of "*port" numbers, return #GNUNET_SYSERR.
 *
 * This is primarily a helper function used internally
 * by #GNUNET_TESTING_peer_configure().
 *
 * @param system system to use to coordinate resource usage
 * @param cfg template configuration to update
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error - the configuration will
 *           be incomplete and should not be used there upon
 */
int
GNUNET_TESTING_configuration_create (struct GNUNET_TESTING_System *system,
				     struct GNUNET_CONFIGURATION_Handle *cfg)
{
  return GNUNET_TESTING_configuration_create_ (system, cfg, NULL, NULL);
}


/**
 * Configure a GNUnet peer.  GNUnet must be installed on the local
 * system and available in the PATH.
 *
 * @param system system to use to coordinate resource usage
 * @param cfg configuration to use; will be UPDATED (to reflect needed
 *            changes in port numbers and paths)
 * @param key_number number of the hostkey to use for the peer
 * @param id identifier for the daemon, will be set, can be NULL
 * @param emsg set to freshly allocated error message (set to NULL on success),
 *          can be NULL
 * @return handle to the peer, NULL on error
 */
struct GNUNET_TESTING_Peer *
GNUNET_TESTING_peer_configure (struct GNUNET_TESTING_System *system,
			       struct GNUNET_CONFIGURATION_Handle *cfg,
			       uint32_t key_number,
			       struct GNUNET_PeerIdentity *id,
			       char **emsg)
{
  struct GNUNET_TESTING_Peer *peer;
  struct GNUNET_DISK_FileHandle *fd;
  char *hostkey_filename;
  char *config_filename;
  char *libexec_binary;
  char *emsg_;
  struct GNUNET_CRYPTO_EddsaPrivateKey *pk;
  uint16_t *ports;
  struct SharedService *ss;
  struct SharedServiceInstance **ss_instances;
  unsigned int cnt;
  unsigned int nports;

  ports = NULL;
  nports = 0;
  ss_instances = NULL;
  if (NULL != emsg)
    *emsg = NULL;
  if (key_number >= system->total_hostkeys)
  {
    GNUNET_asprintf (&emsg_,
		     _("You attempted to create a testbed with more than %u hosts.  Please precompute more hostkeys first.\n"),
		     (unsigned int) system->total_hostkeys);
    goto err_ret;
  }
  pk = NULL;
  if ((NULL != id) &&
      (NULL == (pk = GNUNET_TESTING_hostkey_get (system, key_number, id))))
  {
    GNUNET_asprintf (&emsg_,
		     _("Failed to initialize hostkey for peer %u\n"),
		     (unsigned int) key_number);
    goto err_ret;
  }
  if (NULL != pk)
    GNUNET_free (pk);
  if (GNUNET_NO ==
      GNUNET_CONFIGURATION_have_value (cfg, "PEER", "PRIVATE_KEY"))
  {
    GNUNET_asprintf (&emsg_,
                     _("PRIVATE_KEY option in PEER section missing in configuration\n"));
    goto err_ret;
  }
  /* Remove sections for shared services */
  for (cnt = 0; cnt < system->n_shared_services; cnt++)
  {
    ss = system->shared_services[cnt];
    GNUNET_CONFIGURATION_remove_section (cfg, ss->sname);
  }
  if (GNUNET_OK != GNUNET_TESTING_configuration_create_ (system, cfg,
                                                         &ports, &nports))
  {
    GNUNET_asprintf (&emsg_,
                     _("Failed to create configuration for peer "
                       "(not enough free ports?)\n"));
    goto err_ret;
  }
  GNUNET_assert (GNUNET_OK ==
                 GNUNET_CONFIGURATION_get_value_filename (cfg, "PEER",
							  "PRIVATE_KEY",
							  &hostkey_filename));
  fd = GNUNET_DISK_file_open (hostkey_filename,
                              GNUNET_DISK_OPEN_CREATE | GNUNET_DISK_OPEN_WRITE,
                              GNUNET_DISK_PERM_USER_READ
                              | GNUNET_DISK_PERM_USER_WRITE);
  if (NULL == fd)
  {
    GNUNET_asprintf (&emsg_, _("Cannot open hostkey file `%s': %s\n"),
                     hostkey_filename, STRERROR (errno));
    GNUNET_free (hostkey_filename);
    goto err_ret;
  }
  GNUNET_free (hostkey_filename);
  if (GNUNET_TESTING_HOSTKEYFILESIZE !=
      GNUNET_DISK_file_write (fd, system->hostkeys_data
			      + (key_number * GNUNET_TESTING_HOSTKEYFILESIZE),
			      GNUNET_TESTING_HOSTKEYFILESIZE))
  {
    GNUNET_asprintf (&emsg_,
		     _("Failed to write hostkey file for peer %u: %s\n"),
		     (unsigned int) key_number,
		     STRERROR (errno));
    GNUNET_DISK_file_close (fd);
    goto err_ret;
  }
  GNUNET_DISK_file_close (fd);
  ss_instances = GNUNET_malloc (sizeof (struct SharedServiceInstance *)
                                * system->n_shared_services);
  for (cnt=0; cnt < system->n_shared_services; cnt++)
  {
    ss = system->shared_services[cnt];
    ss_instances[cnt] = associate_shared_service (system, ss, cfg);
    if (NULL == ss_instances[cnt])
    {
      emsg_ = GNUNET_strdup ("FIXME");
      goto err_ret;
    }
  }
  GNUNET_assert (GNUNET_OK ==
                 GNUNET_CONFIGURATION_get_value_filename
                 (cfg, "PATHS", "DEFAULTCONFIG", &config_filename));
  if (GNUNET_OK != GNUNET_CONFIGURATION_write (cfg, config_filename))
  {
    GNUNET_asprintf (&emsg_,
		     _("Failed to write configuration file `%s' for peer %u: %s\n"),
		     config_filename,
		     (unsigned int) key_number,
		     STRERROR (errno));
    GNUNET_free (config_filename);
    goto err_ret;
  }
  peer = GNUNET_new (struct GNUNET_TESTING_Peer);
  peer->ss_instances = ss_instances;
  peer->cfgfile = config_filename; /* Free in peer_destroy */
  peer->cfg = GNUNET_CONFIGURATION_dup (cfg);
  libexec_binary = GNUNET_OS_get_libexec_binary_path ("gnunet-service-arm");
  if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "arm", "PREFIX", &peer->main_binary))
  {
    /* No prefix */
    GNUNET_asprintf(&peer->main_binary, "%s", libexec_binary);
    peer->args = GNUNET_strdup ("");
  }
  else
  {
    peer->args = GNUNET_strdup (libexec_binary);
  }
  peer->system = system;
  peer->key_number = key_number;
  GNUNET_free (libexec_binary);
  peer->ports = ports;          /* Free in peer_destroy */
  peer->nports = nports;
  return peer;

 err_ret:
  GNUNET_free_non_null (ss_instances);
  GNUNET_free_non_null (ports);
  GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "%s", emsg_);
  if (NULL != emsg)
    *emsg = emsg_;
  else
    GNUNET_free (emsg_);
  return NULL;
}


/**
 * Obtain the peer identity from a peer handle.
 *
 * @param peer peer handle for which we want the peer's identity
 * @param id identifier for the daemon, will be set
 */
void
GNUNET_TESTING_peer_get_identity (struct GNUNET_TESTING_Peer *peer,
				  struct GNUNET_PeerIdentity *id)
{
  if (NULL != peer->id)
  {
    GNUNET_memcpy (id, peer->id, sizeof (struct GNUNET_PeerIdentity));
    return;
  }
  peer->id = GNUNET_new (struct GNUNET_PeerIdentity);
  GNUNET_free (GNUNET_TESTING_hostkey_get (peer->system,
							  peer->key_number,
							  peer->id));
  GNUNET_memcpy (id, peer->id, sizeof (struct GNUNET_PeerIdentity));
}


/**
 * Start the peer.
 *
 * @param peer peer to start
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error (i.e. peer already running)
 */
int
GNUNET_TESTING_peer_start (struct GNUNET_TESTING_Peer *peer)
{
  struct SharedServiceInstance *i;
  unsigned int cnt;

  if (NULL != peer->main_process)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  GNUNET_assert (NULL != peer->cfgfile);
  for (cnt = 0; cnt < peer->system->n_shared_services; cnt++)
  {
    i = peer->ss_instances[cnt];
    if ((0 == i->n_refs)
        && (GNUNET_SYSERR == start_shared_service_instance (i)) )
      return GNUNET_SYSERR;
    i->n_refs++;
  }
  peer->main_binary = GNUNET_CONFIGURATION_expand_dollar (peer->cfg, peer->main_binary);
  peer->main_process = GNUNET_OS_start_process_s (PIPE_CONTROL,
                                                  GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
                                                  NULL,
                                                  peer->main_binary,
                                                  peer->args,
                                                  "-c",
                                                  peer->cfgfile,
                                                  NULL);
  if (NULL == peer->main_process)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
		_("Failed to start `%s': %s\n"),
		peer->main_binary,
		STRERROR (errno));
    return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}


/**
 * Sends SIGTERM to the peer's main process
 *
 * @param peer the handle to the peer
 * @return #GNUNET_OK if successful; #GNUNET_SYSERR if the main process is NULL
 *           or upon any error while sending SIGTERM
 */
int
GNUNET_TESTING_peer_kill (struct GNUNET_TESTING_Peer *peer)
{
  struct SharedServiceInstance *i;
  unsigned int cnt;

  if (NULL == peer->main_process)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  if (0 != GNUNET_OS_process_kill (peer->main_process, GNUNET_TERM_SIG))
    return GNUNET_SYSERR;
  for (cnt = 0; cnt < peer->system->n_shared_services; cnt++)
  {
    i = peer->ss_instances[cnt];
    GNUNET_assert (0 != i->n_refs);
    i->n_refs--;
    if (0 == i->n_refs)
      stop_shared_service_instance (i);
  }
  return GNUNET_OK;
}


/**
 * Waits for a peer to terminate. The peer's main process will also be destroyed.
 *
 * @param peer the handle to the peer
 * @return #GNUNET_OK if successful; #GNUNET_SYSERR if the main process is NULL
 *           or upon any error while waiting
 */
int
GNUNET_TESTING_peer_wait (struct GNUNET_TESTING_Peer *peer)
{
  int ret;

  if (NULL == peer->main_process)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  ret = GNUNET_OS_process_wait (peer->main_process);
  GNUNET_OS_process_destroy (peer->main_process);
  peer->main_process = NULL;
  return ret;
}


/**
 * Stop the peer.
 *
 * @param peer peer to stop
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
 */
int
GNUNET_TESTING_peer_stop (struct GNUNET_TESTING_Peer *peer)
{
  if (GNUNET_SYSERR == GNUNET_TESTING_peer_kill (peer))
    return GNUNET_SYSERR;
  if (GNUNET_SYSERR == GNUNET_TESTING_peer_wait (peer))
    return GNUNET_SYSERR;
  return GNUNET_OK;
}


/**
 * Function called whenever we connect to or disconnect from ARM.
 *
 * @param cls closure
 * @param connected #GNUNET_YES if connected, #GNUNET_NO if disconnected,
 *                  #GNUNET_SYSERR on error.
 */
static void
disconn_status (void *cls,
                int connected)
{
  struct GNUNET_TESTING_Peer *peer = cls;

  if (GNUNET_SYSERR == connected)
  {
    peer->cb (peer->cb_cls, peer, connected);
    return;
  }
  if (GNUNET_YES == connected)
  {
    GNUNET_break (GNUNET_OK == GNUNET_TESTING_peer_kill (peer));
    return;
  }
  GNUNET_break (GNUNET_OK == GNUNET_TESTING_peer_wait (peer));
  GNUNET_ARM_disconnect (peer->ah);
  peer->ah = NULL;
  peer->cb (peer->cb_cls, peer, GNUNET_YES);
}


/**
 * Stop a peer asynchronously using ARM API.  Peer's shutdown is signaled
 * through the GNUNET_TESTING_PeerStopCallback().
 *
 * @param peer the peer to stop
 * @param cb the callback to signal peer shutdown
 * @param cb_cls closure for the above callback
 * @return #GNUNET_OK upon successfully giving the request to the ARM API (this
 *           does not mean that the peer is successfully stopped); #GNUNET_SYSERR
 *           upon any error.
 */
int
GNUNET_TESTING_peer_stop_async (struct GNUNET_TESTING_Peer *peer,
                                GNUNET_TESTING_PeerStopCallback cb,
                                void *cb_cls)
{
  if (NULL == peer->main_process)
    return GNUNET_SYSERR;
  peer->ah = GNUNET_ARM_connect (peer->cfg, &disconn_status, peer);
  if (NULL == peer->ah)
    return GNUNET_SYSERR;
  peer->cb = cb;
  peer->cb_cls = cb_cls;
  return GNUNET_OK;
}


/**
 * Cancel a previous asynchronous peer stop request.
 * GNUNET_TESTING_peer_stop_async() should have been called before on the given
 * peer.  It is an error to call this function if the peer stop callback was
 * already called
 *
 * @param peer the peer on which GNUNET_TESTING_peer_stop_async() was called
 *          before.
 */
void
GNUNET_TESTING_peer_stop_async_cancel (struct GNUNET_TESTING_Peer *peer)
{
  GNUNET_assert (NULL != peer->ah);
  GNUNET_ARM_disconnect (peer->ah);
  peer->ah = NULL;
}


/**
 * Destroy the peer.  Releases resources locked during peer configuration.
 * If the peer is still running, it will be stopped AND a warning will be
 * printed (users of the API should stop the peer explicitly first).
 *
 * @param peer peer to destroy
 */
void
GNUNET_TESTING_peer_destroy (struct GNUNET_TESTING_Peer *peer)
{
  unsigned int cnt;

  if (NULL != peer->main_process)
    GNUNET_TESTING_peer_stop (peer);
  if (NULL != peer->ah)
    GNUNET_ARM_disconnect (peer->ah);
  GNUNET_free (peer->cfgfile);
  if (NULL != peer->cfg)
    GNUNET_CONFIGURATION_destroy (peer->cfg);
  GNUNET_free (peer->main_binary);
  GNUNET_free (peer->args);
  GNUNET_free_non_null (peer->id);
  GNUNET_free_non_null (peer->ss_instances);
  if (NULL != peer->ports)
  {
    for (cnt = 0; cnt < peer->nports; cnt++)
      GNUNET_TESTING_release_port (peer->system, peer->ports[cnt]);
    GNUNET_free (peer->ports);
  }
  GNUNET_free (peer);
}


/**
 * Start a single peer and run a test using the testing library.
 * Starts a peer using the given configuration and then invokes the
 * given callback.  This function ALSO initializes the scheduler loop
 * and should thus be called directly from "main".  The testcase
 * should self-terminate by invoking #GNUNET_SCHEDULER_shutdown().
 *
 * @param testdir only the directory name without any path. This is used for
 *          all service homes; the directory will be created in a temporary
 *          location depending on the underlying OS
 * @param cfgfilename name of the configuration file to use;
 *         use NULL to only run with defaults
 * @param tm main function of the testcase
 * @param tm_cls closure for @a tm
 * @return 0 on success, 1 on error
 */
int
GNUNET_TESTING_peer_run (const char *testdir,
			 const char *cfgfilename,
			 GNUNET_TESTING_TestMain tm,
			 void *tm_cls)
{
  return GNUNET_TESTING_service_run (testdir, "arm",
				     cfgfilename, tm, tm_cls);
}


/**
 * Structure for holding service data
 */
struct ServiceContext
{
  /**
   * The configuration of the peer in which the service is run
   */
  const struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Callback to signal service startup
   */
  GNUNET_TESTING_TestMain tm;

  /**
   * The peer in which the service is run.
   */
  struct GNUNET_TESTING_Peer *peer;

  /**
   * Closure for the above callback
   */
  void *tm_cls;
};


/**
 * Callback to be called when SCHEDULER has been started
 *
 * @param cls the ServiceContext
 */
static void
service_run_main (void *cls)
{
  struct ServiceContext *sc = cls;

  sc->tm (sc->tm_cls, sc->cfg, sc->peer);
}


/**
 * Start a single service (no ARM, except of course if the given
 * service name is 'arm') and run a test using the testing library.
 * Starts a service using the given configuration and then invokes the
 * given callback.  This function ALSO initializes the scheduler loop
 * and should thus be called directly from "main".  The testcase
 * should self-terminate by invoking #GNUNET_SCHEDULER_shutdown().
 *
 * This function is useful if the testcase is for a single service
 * and if that service doesn't itself depend on other services.
 *
 * @param testdir only the directory name without any path. This is used for
 *          all service homes; the directory will be created in a temporary
 *          location depending on the underlying OS
 * @param service_name name of the service to run
 * @param cfgfilename name of the configuration file to use;
 *         use NULL to only run with defaults
 * @param tm main function of the testcase
 * @param tm_cls closure for @a tm
 * @return 0 on success, 1 on error
 */
int
GNUNET_TESTING_service_run (const char *testdir,
			    const char *service_name,
			    const char *cfgfilename,
			    GNUNET_TESTING_TestMain tm,
			    void *tm_cls)
{
  struct ServiceContext sc;
  struct GNUNET_TESTING_System *system;
  struct GNUNET_TESTING_Peer *peer;
  struct GNUNET_CONFIGURATION_Handle *cfg;
  char *binary;
  char *libexec_binary;

  GNUNET_log_setup (testdir,
                    "WARNING",
                    NULL);
  system = GNUNET_TESTING_system_create (testdir, "127.0.0.1", NULL, NULL);
  if (NULL == system)
    return 1;
  cfg = GNUNET_CONFIGURATION_create ();
  if (GNUNET_OK != GNUNET_CONFIGURATION_load (cfg, cfgfilename))
  {
    LOG (GNUNET_ERROR_TYPE_ERROR,
	 _("Failed to load configuration from %s\n"), cfgfilename);
    GNUNET_CONFIGURATION_destroy (cfg);
    GNUNET_TESTING_system_destroy (system, GNUNET_YES);
    return 1;
  }
  peer = GNUNET_TESTING_peer_configure (system, cfg, 0, NULL, NULL);
  if (NULL == peer)
  {
    GNUNET_CONFIGURATION_destroy (cfg);
    hostkeys_unload (system);
    GNUNET_TESTING_system_destroy (system, GNUNET_YES);
    return 1;
  }
  GNUNET_free (peer->main_binary);
  GNUNET_free (peer->args);
  GNUNET_asprintf (&binary, "gnunet-service-%s", service_name);
  libexec_binary = GNUNET_OS_get_libexec_binary_path (binary);
  if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, service_name, "PREFIX", &peer->main_binary))
  {
    /* No prefix */
    GNUNET_asprintf(&peer->main_binary, "%s", libexec_binary);
    peer->args = GNUNET_strdup ("");
  }
  else
    peer->args = GNUNET_strdup (libexec_binary);

  GNUNET_free (libexec_binary);
  GNUNET_free (binary);
  if (GNUNET_OK != GNUNET_TESTING_peer_start (peer))
  {
    GNUNET_TESTING_peer_destroy (peer);
    GNUNET_CONFIGURATION_destroy (cfg);
    GNUNET_TESTING_system_destroy (system, GNUNET_YES);
    return 1;
  }
  sc.cfg = cfg;
  sc.tm = tm;
  sc.tm_cls = tm_cls;
  sc.peer = peer;
  GNUNET_SCHEDULER_run (&service_run_main, &sc); /* Scheduler loop */
  if ((NULL != peer->main_process) &&
      (GNUNET_OK != GNUNET_TESTING_peer_stop (peer)))
  {
    GNUNET_TESTING_peer_destroy (peer);
    GNUNET_CONFIGURATION_destroy (cfg);
    GNUNET_TESTING_system_destroy (system, GNUNET_YES);
    return 1;
  }
  GNUNET_TESTING_peer_destroy (peer);
  GNUNET_CONFIGURATION_destroy (cfg);
  GNUNET_TESTING_system_destroy (system, GNUNET_YES);
  return 0;
}


/**
 * Sometimes we use the binary name to determine which specific
 * test to run.  In those cases, the string after the last "_"
 * in 'argv[0]' specifies a string that determines the configuration
 * file or plugin to use.
 *
 * This function returns the respective substring, taking care
 * of issues such as binaries ending in '.exe' on W32.
 *
 * @param argv0 the name of the binary
 * @return string between the last '_' and the '.exe' (or the end of the string),
 *         NULL if argv0 has no '_'
 */
char *
GNUNET_TESTING_get_testname_from_underscore (const char *argv0)
{
  size_t slen = strlen (argv0) + 1;
  char sbuf[slen];
  char *ret;
  char *dot;

  GNUNET_memcpy (sbuf, argv0, slen);
  ret = strrchr (sbuf, '_');
  if (NULL == ret)
    return NULL;
  ret++; /* skip underscore */
  dot = strchr (ret, '.');
  if (NULL != dot)
    *dot = '\0';
  return GNUNET_strdup (ret);
}


/* end of testing.c */