gnunet-daemon-topology.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2007-2016 GNUnet e.V.

     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     or (at your option) any later version.

     GNUnet is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Affero General Public License for more details.

     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.

     SPDX-License-Identifier: AGPL3.0-or-later
 */

#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_friends_lib.h"
#include "gnunet_constants.h"
#include "gnunet_core_service.h"
#include "gnunet_protocols.h"
#include "gnunet_peerinfo_service.h"
#include "gnunet_statistics_service.h"
#include "gnunet_transport_service.h"
#include "gnunet_ats_service.h"


#define HELLO_ADVERTISEMENT_MIN_FREQUENCY \
  GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 5)

#define HELLO_ADVERTISEMENT_MIN_REPEAT_FREQUENCY \
  GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_HOURS, 4)


struct Peer {
  struct GNUNET_PeerIdentity pid;

  struct GNUNET_MQ_Handle *mq;

  struct GNUNET_HELLO_Message *hello;

  struct GNUNET_CONTAINER_BloomFilter *filter;

  struct GNUNET_TIME_Absolute next_hello_allowed;

  struct GNUNET_TIME_Absolute filter_expiration;

  struct GNUNET_SCHEDULER_Task *hello_delay_task;

  struct GNUNET_ATS_ConnectivitySuggestHandle *sh;

  uint32_t strength;

  int is_friend;
};


static struct GNUNET_PEERINFO_NotifyContext *peerinfo_notify;

static const struct GNUNET_CONFIGURATION_Handle *cfg;

static struct GNUNET_CORE_Handle *handle;

static struct GNUNET_PEERINFO_Handle *pi;

static struct GNUNET_ATS_ConnectivityHandle *ats;

static struct GNUNET_PeerIdentity my_identity;

static struct GNUNET_CONTAINER_MultiPeerMap *peers;

static struct GNUNET_STATISTICS_Handle *stats;

static struct GNUNET_TRANSPORT_Blacklist *blacklist;

static struct GNUNET_SCHEDULER_Task *add_task;

static struct GNUNET_TRANSPORT_OfferHelloHandle *oh;

static int friends_only;

static unsigned int minimum_friend_count;

static unsigned int connection_count;

static unsigned int target_connection_count;

static unsigned int friend_count;


static int
blacklist_check(void *cls, const struct GNUNET_PeerIdentity *pid)
{
  struct Peer *pos;

  pos = GNUNET_CONTAINER_multipeermap_get(peers, pid);
  if ((NULL != pos) && (GNUNET_YES == pos->is_friend))
    return GNUNET_OK;
  GNUNET_STATISTICS_update(stats,
                           gettext_noop("# peers blacklisted"),
                           1,
                           GNUNET_NO);
  return GNUNET_SYSERR;
}


static void
whitelist_peers()
{
  if (NULL != blacklist)
    {
      GNUNET_TRANSPORT_blacklist_cancel(blacklist);
      blacklist = NULL;
    }
}


static int
free_peer(void *cls, const struct GNUNET_PeerIdentity *pid, void *value)
{
  struct Peer *pos = value;

  GNUNET_break(NULL == pos->mq);
  GNUNET_break(GNUNET_OK ==
               GNUNET_CONTAINER_multipeermap_remove(peers, pid, pos));
  if (NULL != pos->hello_delay_task)
    {
      GNUNET_SCHEDULER_cancel(pos->hello_delay_task);
      pos->hello_delay_task = NULL;
    }
  if (NULL != pos->sh)
    {
      GNUNET_ATS_connectivity_suggest_cancel(pos->sh);
      pos->sh = NULL;
    }
  if (NULL != pos->hello)
    {
      GNUNET_free_non_null(pos->hello);
      pos->hello = NULL;
    }
  if (NULL != pos->filter)
    {
      GNUNET_CONTAINER_bloomfilter_free(pos->filter);
      pos->filter = NULL;
    }
  GNUNET_free(pos);
  return GNUNET_YES;
}


static void
attempt_connect(struct Peer *pos)
{
  uint32_t strength;

  if (0 == GNUNET_memcmp(&my_identity, &pos->pid))
    return; /* This is myself, nothing to do. */
  if (connection_count < target_connection_count)
    strength = 1;
  else
    strength = 0;
  if ((friend_count < minimum_friend_count) || (GNUNET_YES == friends_only))
    {
      if (pos->is_friend)
        strength += 10; /* urgently needed */
      else
        strength = 0; /* disallowed */
    }
  if (pos->is_friend)
    strength *= 2; /* friends always count more */
  if (NULL != pos->mq)
    strength *= 2; /* existing connections preferred */
  if (strength == pos->strength)
    return; /* nothing to do */
  if (NULL != pos->sh)
    {
      GNUNET_ATS_connectivity_suggest_cancel(pos->sh);
      pos->sh = NULL;
    }
  pos->strength = strength;
  if (0 != strength)
    {
      GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
                 "Asking to connect to `%s' with strength %u\n",
                 GNUNET_i2s(&pos->pid),
                 (unsigned int)strength);
      GNUNET_STATISTICS_update(stats,
                               gettext_noop("# connect requests issued to ATS"),
                               1,
                               GNUNET_NO);
      pos->sh = GNUNET_ATS_connectivity_suggest(ats, &pos->pid, strength);
    }
}


static struct Peer *
make_peer(const struct GNUNET_PeerIdentity *peer,
          const struct GNUNET_HELLO_Message *hello,
          int is_friend)
{
  struct Peer *ret;

  ret = GNUNET_new(struct Peer);
  ret->pid = *peer;
  ret->is_friend = is_friend;
  if (NULL != hello)
    {
      ret->hello = GNUNET_malloc(GNUNET_HELLO_size(hello));
      GNUNET_memcpy(ret->hello, hello, GNUNET_HELLO_size(hello));
    }
  GNUNET_break(GNUNET_OK ==
               GNUNET_CONTAINER_multipeermap_put(
                 peers,
                 peer,
                 ret,
                 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
  return ret;
}


static void
setup_filter(struct Peer *peer)
{
  struct GNUNET_HashCode hc;

  /* 2^{-5} chance of not sending a HELLO to a peer is
   * acceptably small (if the filter is 50% full);
   * 64 bytes of memory are small compared to the rest
   * of the data structure and would only really become
   * "useless" once a HELLO has been passed on to ~100
   * other peers, which is likely more than enough in
   * any case; hence 64, 5 as bloomfilter parameters. */
  peer->filter = GNUNET_CONTAINER_bloomfilter_init(NULL, 64, 5);
  peer->filter_expiration =
    GNUNET_TIME_relative_to_absolute(HELLO_ADVERTISEMENT_MIN_REPEAT_FREQUENCY);
  /* never send a peer its own HELLO */
  GNUNET_CRYPTO_hash(&peer->pid, sizeof(struct GNUNET_PeerIdentity), &hc);
  GNUNET_CONTAINER_bloomfilter_add(peer->filter, &hc);
}


struct FindAdvHelloContext {
  struct Peer *peer;

  struct Peer *result;

  size_t max_size;

  struct GNUNET_TIME_Relative next_adv;
};


static int
find_advertisable_hello(void *cls,
                        const struct GNUNET_PeerIdentity *pid,
                        void *value)
{
  struct FindAdvHelloContext *fah = cls;
  struct Peer *pos = value;
  struct GNUNET_TIME_Relative rst_time;
  struct GNUNET_HashCode hc;
  size_t hs;

  if (pos == fah->peer)
    return GNUNET_YES;
  if (pos->hello == NULL)
    return GNUNET_YES;
  rst_time = GNUNET_TIME_absolute_get_remaining(pos->filter_expiration);
  if (0 == rst_time.rel_value_us)
    {
      /* time to discard... */
      GNUNET_CONTAINER_bloomfilter_free(pos->filter);
      setup_filter(pos);
    }
  fah->next_adv = GNUNET_TIME_relative_min(rst_time, fah->next_adv);
  hs = GNUNET_HELLO_size(pos->hello);
  if (hs > fah->max_size)
    return GNUNET_YES;
  GNUNET_CRYPTO_hash(&fah->peer->pid,
                     sizeof(struct GNUNET_PeerIdentity),
                     &hc);
  if (GNUNET_NO == GNUNET_CONTAINER_bloomfilter_test(pos->filter, &hc))
    fah->result = pos;
  return GNUNET_YES;
}


static void
schedule_next_hello(void *cls)
{
  struct Peer *pl = cls;
  struct FindAdvHelloContext fah;
  struct GNUNET_MQ_Envelope *env;
  size_t want;
  struct GNUNET_TIME_Relative delay;
  struct GNUNET_HashCode hc;

  pl->hello_delay_task = NULL;
  GNUNET_assert(NULL != pl->mq);
  /* find applicable HELLOs */
  fah.peer = pl;
  fah.result = NULL;
  fah.max_size = GNUNET_MAX_MESSAGE_SIZE - 1;
  fah.next_adv = GNUNET_TIME_UNIT_FOREVER_REL;
  GNUNET_CONTAINER_multipeermap_iterate(peers, &find_advertisable_hello, &fah);
  pl->hello_delay_task =
    GNUNET_SCHEDULER_add_delayed(fah.next_adv, &schedule_next_hello, pl);
  if (NULL == fah.result)
    return;
  delay = GNUNET_TIME_absolute_get_remaining(pl->next_hello_allowed);
  if (0 != delay.rel_value_us)
    return;

  want = GNUNET_HELLO_size(fah.result->hello);
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
             "Sending HELLO with %u bytes",
             (unsigned int)want);
  env = GNUNET_MQ_msg_copy(&fah.result->hello->header);
  GNUNET_MQ_send(pl->mq, env);

  /* avoid sending this one again soon */
  GNUNET_CRYPTO_hash(&pl->pid, sizeof(struct GNUNET_PeerIdentity), &hc);
  GNUNET_CONTAINER_bloomfilter_add(fah.result->filter, &hc);

  GNUNET_STATISTICS_update(stats,
                           gettext_noop("# HELLO messages gossipped"),
                           1,
                           GNUNET_NO);
  /* prepare to send the next one */
  pl->next_hello_allowed =
    GNUNET_TIME_relative_to_absolute(HELLO_ADVERTISEMENT_MIN_FREQUENCY);
  if (NULL != pl->hello_delay_task)
    GNUNET_SCHEDULER_cancel(pl->hello_delay_task);
  pl->hello_delay_task = GNUNET_SCHEDULER_add_now(&schedule_next_hello, pl);
}


static int
reschedule_hellos(void *cls,
                  const struct GNUNET_PeerIdentity *pid,
                  void *value)
{
  struct Peer *peer = value;
  struct Peer *skip = cls;

  if (skip == peer)
    return GNUNET_YES;
  if (NULL == peer->mq)
    return GNUNET_YES;
  if (NULL != peer->hello_delay_task)
    {
      GNUNET_SCHEDULER_cancel(peer->hello_delay_task);
      peer->hello_delay_task = NULL;
    }
  peer->hello_delay_task =
    GNUNET_SCHEDULER_add_now(&schedule_next_hello, peer);
  return GNUNET_YES;
}


static void *
connect_notify(void *cls,
               const struct GNUNET_PeerIdentity *peer,
               struct GNUNET_MQ_Handle *mq)
{
  struct Peer *pos;

  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
             "Core told us that we are connecting to `%s'\n",
             GNUNET_i2s(peer));
  if (0 == GNUNET_memcmp(&my_identity, peer))
    return NULL;
  GNUNET_MQ_set_options(mq, GNUNET_MQ_PRIO_BEST_EFFORT);
  connection_count++;
  GNUNET_STATISTICS_set(stats,
                        gettext_noop("# peers connected"),
                        connection_count,
                        GNUNET_NO);
  pos = GNUNET_CONTAINER_multipeermap_get(peers, peer);
  if (NULL == pos)
    {
      pos = make_peer(peer, NULL, GNUNET_NO);
    }
  else
    {
      GNUNET_assert(NULL == pos->mq);
    }
  pos->mq = mq;
  if (pos->is_friend)
    {
      friend_count++;
      if ((friend_count == minimum_friend_count) && (GNUNET_YES != friends_only))
        whitelist_peers();
      GNUNET_STATISTICS_set(stats,
                            gettext_noop("# friends connected"),
                            friend_count,
                            GNUNET_NO);
    }
  reschedule_hellos(NULL, peer, pos);
  return pos;
}


static int
try_add_peers(void *cls, const struct GNUNET_PeerIdentity *pid, void *value)
{
  struct Peer *pos = value;

  attempt_connect(pos);
  return GNUNET_YES;
}


static void
add_peer_task(void *cls)
{
  add_task = NULL;

  GNUNET_CONTAINER_multipeermap_iterate(peers, &try_add_peers, NULL);
}


static void
disconnect_notify(void *cls,
                  const struct GNUNET_PeerIdentity *peer,
                  void *internal_cls)
{
  struct Peer *pos = internal_cls;

  if (NULL == pos)
    return; /* myself, we're shutting down */
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
             "Core told us that we disconnected from `%s'\n",
             GNUNET_i2s(peer));
  if (NULL == pos->mq)
    {
      GNUNET_break(0);
      return;
    }
  pos->mq = NULL;
  connection_count--;
  if (NULL != pos->hello_delay_task)
    {
      GNUNET_SCHEDULER_cancel(pos->hello_delay_task);
      pos->hello_delay_task = NULL;
    }
  GNUNET_STATISTICS_set(stats,
                        gettext_noop("# peers connected"),
                        connection_count,
                        GNUNET_NO);
  if (pos->is_friend)
    {
      friend_count--;
      GNUNET_STATISTICS_set(stats,
                            gettext_noop("# friends connected"),
                            friend_count,
                            GNUNET_NO);
    }
  if (((connection_count < target_connection_count) ||
       (friend_count < minimum_friend_count)) &&
      (NULL == add_task))
    add_task = GNUNET_SCHEDULER_add_now(&add_peer_task, NULL);
  if ((friend_count < minimum_friend_count) && (NULL == blacklist))
    blacklist = GNUNET_TRANSPORT_blacklist(cfg, &blacklist_check, NULL);
}


static int
address_iterator(void *cls,
                 const struct GNUNET_HELLO_Address *address,
                 struct GNUNET_TIME_Absolute expiration)
{
  int *flag = cls;

  *flag = GNUNET_YES;
  return GNUNET_SYSERR;
}


static void
consider_for_advertising(const struct GNUNET_HELLO_Message *hello)
{
  int have_address;
  struct GNUNET_PeerIdentity pid;
  struct GNUNET_TIME_Absolute dt;
  struct GNUNET_HELLO_Message *nh;
  struct Peer *peer;
  uint16_t size;

  if (GNUNET_OK != GNUNET_HELLO_get_id(hello, &pid))
    {
      GNUNET_break(0);
      return;
    }
  if (0 == GNUNET_memcmp(&pid, &my_identity))
    return; /* that's me! */
  have_address = GNUNET_NO;
  GNUNET_HELLO_iterate_addresses(hello,
                                 GNUNET_NO,
                                 &address_iterator,
                                 &have_address);
  if (GNUNET_NO == have_address)
    return; /* no point in advertising this one... */
  peer = GNUNET_CONTAINER_multipeermap_get(peers, &pid);
  if (NULL == peer)
    {
      peer = make_peer(&pid, hello, GNUNET_NO);
    }
  else if (NULL != peer->hello)
    {
      dt = GNUNET_HELLO_equals(peer->hello, hello, GNUNET_TIME_absolute_get());
      if (dt.abs_value_us == GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us)
        return; /* nothing new here */
    }
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
             "Found HELLO from peer `%s' for advertising\n",
             GNUNET_i2s(&pid));
  if (NULL != peer->hello)
    {
      nh = GNUNET_HELLO_merge(peer->hello, hello);
      GNUNET_free(peer->hello);
      peer->hello = nh;
    }
  else
    {
      size = GNUNET_HELLO_size(hello);
      peer->hello = GNUNET_malloc(size);
      GNUNET_memcpy(peer->hello, hello, size);
    }
  if (NULL != peer->filter)
    {
      GNUNET_CONTAINER_bloomfilter_free(peer->filter);
      peer->filter = NULL;
    }
  setup_filter(peer);
  /* since we have a new HELLO to pick from, re-schedule all
   * HELLO requests that are not bound by the HELLO send rate! */
  GNUNET_CONTAINER_multipeermap_iterate(peers, &reschedule_hellos, peer);
}


static void
process_peer(void *cls,
             const struct GNUNET_PeerIdentity *peer,
             const struct GNUNET_HELLO_Message *hello,
             const char *err_msg)
{
  struct Peer *pos;

  if (NULL != err_msg)
    {
      GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
                 _("Error in communication with PEERINFO service: %s\n"),
                 err_msg);
      GNUNET_PEERINFO_notify_cancel(peerinfo_notify);
      peerinfo_notify =
        GNUNET_PEERINFO_notify(cfg, GNUNET_NO, &process_peer, NULL);
      return;
    }
  GNUNET_assert(NULL != peer);
  if (0 == GNUNET_memcmp(&my_identity, peer))
    return; /* that's me! */
  if (NULL == hello)
    {
      /* free existing HELLO, if any */
      pos = GNUNET_CONTAINER_multipeermap_get(peers, peer);
      if (NULL != pos)
        {
          GNUNET_free_non_null(pos->hello);
          pos->hello = NULL;
          if (NULL != pos->filter)
            {
              GNUNET_CONTAINER_bloomfilter_free(pos->filter);
              pos->filter = NULL;
            }
          if ((NULL == pos->mq) && (GNUNET_NO == pos->is_friend))
            free_peer(NULL, &pos->pid, pos);
        }
      return;
    }
  consider_for_advertising(hello);
  pos = GNUNET_CONTAINER_multipeermap_get(peers, peer);
  if (NULL == pos)
    pos = make_peer(peer, hello, GNUNET_NO);
  attempt_connect(pos);
}


static void
core_init(void *cls, const struct GNUNET_PeerIdentity *my_id)
{
  if (NULL == my_id)
    {
      GNUNET_log(
        GNUNET_ERROR_TYPE_ERROR,
        _("Failed to connect to core service, can not manage topology!\n"));
      GNUNET_SCHEDULER_shutdown();
      return;
    }
  my_identity = *my_id;
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "I am peer `%s'\n", GNUNET_i2s(my_id));
  peerinfo_notify =
    GNUNET_PEERINFO_notify(cfg, GNUNET_NO, &process_peer, NULL);
}


static void
handle_friend(void *cls, const struct GNUNET_PeerIdentity *pid)
{
  unsigned int *entries_found = cls;
  struct Peer *fl;

  if (0 == GNUNET_memcmp(pid, &my_identity))
    {
      GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
                 _("Found myself `%s' in friend list (useless, ignored)\n"),
                 GNUNET_i2s(pid));
      return;
    }
  (*entries_found)++;
  fl = make_peer(pid, NULL, GNUNET_YES);
  GNUNET_log(GNUNET_ERROR_TYPE_INFO,
             _("Found friend `%s' in configuration\n"),
             GNUNET_i2s(&fl->pid));
}


static void
read_friends_file(const struct GNUNET_CONFIGURATION_Handle *cfg)
{
  unsigned int entries_found;

  entries_found = 0;
  if (GNUNET_OK != GNUNET_FRIENDS_parse(cfg, &handle_friend, &entries_found))
    {
      if ((GNUNET_YES == friends_only) || (minimum_friend_count > 0))
        GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
                   _("Encountered errors parsing friends list!\n"));
    }
  GNUNET_STATISTICS_update(stats,
                           gettext_noop("# friends in configuration"),
                           entries_found,
                           GNUNET_NO);
  if ((minimum_friend_count > entries_found) && (GNUNET_NO == friends_only))
    {
      GNUNET_log(
        GNUNET_ERROR_TYPE_WARNING,
        _(
          "Fewer friends specified than required by minimum friend count. Will only connect to friends.\n"));
    }
  if ((minimum_friend_count > target_connection_count) &&
      (GNUNET_NO == friends_only))
    {
      GNUNET_log(
        GNUNET_ERROR_TYPE_WARNING,
        _(
          "More friendly connections required than target total number of connections.\n"));
    }
}


static int
check_hello(void *cls, const struct GNUNET_HELLO_Message *message)
{
  struct GNUNET_PeerIdentity pid;

  if (GNUNET_OK != GNUNET_HELLO_get_id(message, &pid))
    {
      GNUNET_break_op(0);
      return GNUNET_SYSERR;
    }
  return GNUNET_OK;
}


static void
handle_hello(void *cls, const struct GNUNET_HELLO_Message *message)
{
  const struct GNUNET_PeerIdentity *other = cls;
  struct Peer *peer;
  struct GNUNET_PeerIdentity pid;

  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
             "Received encrypted HELLO from peer `%s'",
             GNUNET_i2s(other));
  GNUNET_assert(GNUNET_OK == GNUNET_HELLO_get_id(message, &pid));
  GNUNET_STATISTICS_update(stats,
                           gettext_noop("# HELLO messages received"),
                           1,
                           GNUNET_NO);
  peer = GNUNET_CONTAINER_multipeermap_get(peers, &pid);
  if (NULL == peer)
    {
      if ((GNUNET_YES == friends_only) || (friend_count < minimum_friend_count))
        return;
    }
  else
    {
      if ((GNUNET_YES != peer->is_friend) && (GNUNET_YES == friends_only))
        return;
      if ((GNUNET_YES != peer->is_friend) &&
          (friend_count < minimum_friend_count))
        return;
    }
  (void)GNUNET_PEERINFO_add_peer(pi, message, NULL, NULL);
}


static void
cleaning_task(void *cls)
{
  if (NULL != peerinfo_notify)
    {
      GNUNET_PEERINFO_notify_cancel(peerinfo_notify);
      peerinfo_notify = NULL;
    }
  if (NULL != handle)
    {
      GNUNET_CORE_disconnect(handle);
      handle = NULL;
    }
  whitelist_peers();
  if (NULL != add_task)
    {
      GNUNET_SCHEDULER_cancel(add_task);
      add_task = NULL;
    }
  if (NULL != oh)
    {
      GNUNET_TRANSPORT_offer_hello_cancel(oh);
      oh = NULL;
    }
  GNUNET_CONTAINER_multipeermap_iterate(peers, &free_peer, NULL);
  GNUNET_CONTAINER_multipeermap_destroy(peers);
  peers = NULL;
  if (NULL != ats)
    {
      GNUNET_ATS_connectivity_done(ats);
      ats = NULL;
    }
  if (NULL != pi)
    {
      GNUNET_PEERINFO_disconnect(pi);
      pi = NULL;
    }
  if (NULL != stats)
    {
      GNUNET_STATISTICS_destroy(stats, GNUNET_NO);
      stats = NULL;
    }
}


static void
run(void *cls,
    char *const *args,
    const char *cfgfile,
    const struct GNUNET_CONFIGURATION_Handle *c)
{
  struct GNUNET_MQ_MessageHandler handlers[] =
  { GNUNET_MQ_hd_var_size(hello,
                          GNUNET_MESSAGE_TYPE_HELLO,
                          struct GNUNET_HELLO_Message,
                          NULL),
    GNUNET_MQ_handler_end() };
  unsigned long long opt;

  cfg = c;
  stats = GNUNET_STATISTICS_create("topology", cfg);
  friends_only =
    GNUNET_CONFIGURATION_get_value_yesno(cfg, "TOPOLOGY", "FRIENDS-ONLY");
  if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_number(cfg,
                                                         "TOPOLOGY",
                                                         "MINIMUM-FRIENDS",
                                                         &opt))
    opt = 0;
  minimum_friend_count = (unsigned int)opt;
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_number(cfg,
                                            "TOPOLOGY",
                                            "TARGET-CONNECTION-COUNT",
                                            &opt))
    opt = 16;
  target_connection_count = (unsigned int)opt;
  peers = GNUNET_CONTAINER_multipeermap_create(target_connection_count * 2,
                                               GNUNET_NO);
  read_friends_file(cfg);
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
             "Topology would like %u connections with at least %u friends\n",
             target_connection_count,
             minimum_friend_count);
  if ((GNUNET_YES == friends_only) || (minimum_friend_count > 0))
    blacklist = GNUNET_TRANSPORT_blacklist(cfg, &blacklist_check, NULL);
  ats = GNUNET_ATS_connectivity_init(cfg);
  pi = GNUNET_PEERINFO_connect(cfg);
  handle = GNUNET_CORE_connect(cfg,
                               NULL,
                               &core_init,
                               &connect_notify,
                               &disconnect_notify,
                               handlers);
  GNUNET_SCHEDULER_add_shutdown(&cleaning_task, NULL);
  if (NULL == handle)
    {
      GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
                 _("Failed to connect to `%s' service.\n"),
                 "core");
      GNUNET_SCHEDULER_shutdown();
      return;
    }
}


int
main(int argc, char *const *argv)
{
  static const struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_OPTION_END
  };
  int ret;

  if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args(argc, argv, &argc, &argv))
    return 2;

  ret = (GNUNET_OK == GNUNET_PROGRAM_run(argc,
                                         argv,
                                         "gnunet-daemon-topology",
                                         _("GNUnet topology control"),
                                         options,
                                         &run,
                                         NULL))
        ? 0
        : 1;
  GNUNET_free((void *)argv);
  return ret;
}


#if defined(LINUX) && defined(__GLIBC__)
#include <malloc.h>

void __attribute__ ((constructor)) GNUNET_ARM_memory_init()
{
  mallopt(M_TRIM_THRESHOLD, 4 * 1024);
  mallopt(M_TOP_PAD, 1 * 1024);
  malloc_trim(0);
}
#endif

/* end of gnunet-daemon-topology.c */