leaks
[oweals/gnunet.git] / src / topology / gnunet-daemon-topology.c
index a67023542b8f32f16eadd5ddbcc70646afe77e31..30ad925a7508582cb754526e8e05abf64b4102e3 100644 (file)
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2007, 2008, 2009 Christian Grothoff (and other contributing authors)
+     (C) 2007, 2008, 2009, 2010 Christian Grothoff (and other contributing authors)
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
@@ -20,7 +20,7 @@
 
 /**
  * @file topology/gnunet-daemon-topology.c
- * @brief code for bootstrapping via topology servers
+ * @brief code for maintaining the mesh topology
  * @author Christian Grothoff
  */
 
 #define DEBUG_TOPOLOGY GNUNET_NO
 
 /**
- * For how long do we blacklist a peer after a failed
- * connection attempt?
+ * For how long do we blacklist a peer after a failed connection
+ * attempt?
  */
 #define BLACKLIST_AFTER_ATTEMPT GNUNET_TIME_UNIT_HOURS
 
 /**
- * For how long do we blacklist a friend after a failed
- * connection attempt?
+ * For how long do we blacklist a friend after a failed connection
+ * attempt?
  */
 #define BLACKLIST_AFTER_ATTEMPT_FRIEND GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
 
 /**
- * How frequently are we allowed to ask PEERINFO for more
- * HELLO's to advertise (at most)?
+ * How often do we at most advertise any HELLO to a peer?
  */
-#define MIN_HELLO_GATHER_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 27)
+#define HELLO_ADVERTISEMENT_MIN_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 4)
 
 /**
  * How often do we at most advertise the same HELLO to the same peer?
- * Also used to remove HELLOs of peers that PEERINFO no longer lists
- * from our cache.
  */
-#define HELLO_ADVERTISEMENT_MIN_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 12)
+#define HELLO_ADVERTISEMENT_MIN_REPEAT_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 4)
 
 
 /**
@@ -72,6 +69,35 @@ struct PeerList
    */
   struct PeerList *next;
 
+  /**
+   * Our handle for the request to transmit HELLOs to this peer; NULL
+   * if no such request is pending.
+   */
+  struct GNUNET_CORE_TransmitHandle *hello_req;  
+
+  /**
+   * Our handle for the request to connect to this peer; NULL if no
+   * such request is pending.
+   */
+  struct GNUNET_CORE_PeerRequestHandle *connect_req;  
+
+  /**
+   * Pointer to the HELLO message of this peer; can be NULL.
+   */
+  struct GNUNET_HELLO_Message *hello;
+
+  /**
+   * Bloom filter used to mark which peers already got the HELLO
+   * from this peer.
+   */
+  struct GNUNET_CONTAINER_BloomFilter *filter;
+
+  /**
+   * Our request handle for *whitelisting* this peer (NULL if
+   * no whitelisting request is pending).
+   */
+  struct GNUNET_TRANSPORT_BlacklistRequest *wh;
+
   /**
    * Is this peer listed here because he is a friend?
    */
@@ -82,6 +108,11 @@ struct PeerList
    */
   int is_connected;
 
+  /**
+   * Are we currently blocking this peer (via blacklist)?
+   */
+  int is_blocked;
+
   /**
    * Until what time should we not try to connect again
    * to this peer?
@@ -89,9 +120,20 @@ struct PeerList
   struct GNUNET_TIME_Absolute blacklisted_until;
 
   /**
-   * Last time we transmitted a HELLO to this peer?
+   * Next time we are allowed to transmit a HELLO to this peer?
+   */
+  struct GNUNET_TIME_Absolute next_hello_allowed;
+
+  /**
+   * When should we reset the bloom filter of this entry?
+   */
+  struct GNUNET_TIME_Absolute filter_expiration;
+
+  /**
+   * ID of task we use to wait for the time to send the next HELLO
+   * to this peer.
    */
-  struct GNUNET_TIME_Absolute last_hello_sent;
+  GNUNET_SCHEDULER_TaskIdentifier hello_delay_task;
 
   /**
    * ID of the peer.
@@ -102,56 +144,48 @@ struct PeerList
 
 
 /**
- * List of HELLOs we may consider for advertising.
+ * Entry in linked list of active 'disconnect' requests that we have issued.
  */
-struct HelloList
+struct DisconnectList
 {
   /**
-   * This is a linked list.
+   * This is a doubly-linked list.
    */
-  struct HelloList *next;
+  struct DisconnectList *next;
 
   /**
-   * Pointer to the HELLO message.  Memory allocated as part
-   * of the "struct HelloList" --- do not free!
+   * This is a doubly-linked list.
    */
-  struct GNUNET_HELLO_Message *msg;
-
+  struct DisconnectList *prev;
+  
   /**
-   * Bloom filter used to mark which peers already got
-   * this HELLO.
+   * Our request handle.
    */
-  struct GNUNET_CONTAINER_BloomFilter *filter;
-
+  struct GNUNET_TRANSPORT_BlacklistRequest *rh;
+  
   /**
-   * What peer is this HELLO for?
+   * Peer we tried to disconnect.
    */
-  struct GNUNET_PeerIdentity id;
+  struct GNUNET_PeerIdentity peer;
 
-  /**
-   * When should we remove this entry from the linked list (either
-   * resetting the filter or possibly eliminating it for good because
-   * we no longer consider the peer to be participating in the
-   * network)?
-   */
-  struct GNUNET_TIME_Absolute expiration;
 };
 
 
 /**
- * Linked list of HELLOs for advertising.
+ * Our peerinfo notification context.  We use notification
+ * to instantly learn about new peers as they are discovered.
  */
-static struct HelloList *hellos;
+static struct GNUNET_PEERINFO_NotifyContext *peerinfo_notify;
 
 /**
  * Our scheduler.
  */
-static struct GNUNET_SCHEDULER_Handle * sched;
+static struct GNUNET_SCHEDULER_Handle *sched;
 
 /**
  * Our configuration.
  */
-static const struct GNUNET_CONFIGURATION_Handle * cfg;
+static const struct GNUNET_CONFIGURATION_Handle *cfg;
 
 /**
  * Handle to the core API.
@@ -169,15 +203,10 @@ static struct GNUNET_TRANSPORT_Handle *transport;
 static struct GNUNET_PeerIdentity my_identity;
 
 /**
- * Linked list of all of our friends and all of our current
- * neighbours.
- */
-static struct PeerList *friends;
-
-/**
- * Timestamp from the last time we tried to gather HELLOs.
+ * Linked list of all of our friends, all of our current neighbours
+ * and all peers for which we have HELLOs.  So pretty much everyone.
  */
-static struct GNUNET_TIME_Absolute last_hello_gather_time;
+static struct PeerList *peers;
 
 /**
  * Flag to disallow non-friend connections (pure F2F mode).
@@ -211,98 +240,177 @@ static unsigned int friend_count;
 static int autoconnect;
 
 /**
- * Are we currently having a request pending with
- * PEERINFO asking for HELLOs for advertising?
+ * Head of doubly-linked list of active 'disconnect' requests that we have issued.
  */
-static int hello_gathering_active;
+static struct DisconnectList *disconnect_head;
 
+/**
+ * Head of doubly-linked list of active 'disconnect' requests that we have issued.
+ */
+static struct DisconnectList *disconnect_tail;
 
 
 /**
- * Force a disconnect from the specified peer.
+ * Function called once our request to 'disconnect' a peer
+ * has completed.
+ *
+ * @param cls our 'struct DisconnectList'
+ * @param tc unused
  */
 static void
-force_disconnect (const struct GNUNET_PeerIdentity *peer)
+disconnect_done (void *cls,
+                const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
-  GNUNET_CORE_peer_configure (handle,
-                             peer,
-                             GNUNET_TIME_UNIT_FOREVER_REL,
-                             0,
-                             0,
-                             0,
-                             NULL,
-                             NULL);
+  struct DisconnectList *dl = cls;
+
+  GNUNET_CONTAINER_DLL_remove (disconnect_head,
+                              disconnect_tail,
+                              dl);
+  GNUNET_free (dl);
 }
 
 
 /**
- * Function called by core when our attempt to connect
- * succeeded.  Does nothing.
+ * Force a disconnect from the specified peer. 
  */
-static size_t
-ready_callback (void *cls,
-               size_t size, void *buf)
+static void
+force_disconnect (struct PeerList *pl)
 {
-  return 0;
+  const struct GNUNET_PeerIdentity *peer = &pl->id;
+  struct DisconnectList *dl;
+
+  if (NULL != pl->wh)
+    {
+      GNUNET_TRANSPORT_blacklist_cancel (pl->wh);
+      pl->wh = NULL;
+    }
+  pl->is_blocked = GNUNET_YES;
+  dl = GNUNET_malloc (sizeof (struct DisconnectList));
+  dl->peer = *peer;
+  GNUNET_CONTAINER_DLL_insert (disconnect_head,
+                              disconnect_tail,
+                              dl);
+  dl->rh = GNUNET_TRANSPORT_blacklist (sched, cfg,                                             
+                                      peer,
+                                      GNUNET_TIME_UNIT_FOREVER_REL,
+                                      GNUNET_TIME_UNIT_FOREVER_REL,
+                                      &disconnect_done,
+                                      dl);
 }
 
 
+
 /**
- * Try to connect to the specified peer.
+ * Function called once our request to 'whitelist' a peer
+ * has completed.
  *
- * @param pos NULL if not in friend list yet
+ * @param cls our 'struct PeerList'
+ * @param tc unused
  */
 static void
-attempt_connect (const struct GNUNET_PeerIdentity *peer,
-                struct PeerList *pos)
+whitelist_done (void *cls,
+               const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
-  if (pos == NULL)
+  struct PeerList *pl = cls;
+
+  pl->wh = NULL;
+}
+
+
+/**
+ * Whitelist all peers that we blacklisted; we've passed
+ * the minimum number of friends.
+ */
+static void
+whitelist_peers ()
+{
+  struct PeerList *pl;
+  struct DisconnectList *dl;
+
+  /* first, cancel all blacklisting requests */
+  while (NULL != (dl = disconnect_head))
     {
-      pos = friends;
-      while (pos != NULL)
-       {
-         if (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity)))
-           break;
-       }
+      GNUNET_CONTAINER_DLL_remove (disconnect_head,
+                                  disconnect_tail,
+                                  dl);
+      GNUNET_TRANSPORT_blacklist_cancel (dl->rh);
+      GNUNET_free (dl);
     }
-  if (pos == NULL)
+  /* then, specifically whitelist all peers that we
+     know to have blacklisted */
+  pl = peers;
+  while (pl != NULL)
     {
-      pos = GNUNET_malloc (sizeof(struct PeerList));
-      pos->id = *peer;
-      pos->next = friends;
-      friends = pos;
+      if (pl->is_blocked)
+       {
+         pl->wh = GNUNET_TRANSPORT_blacklist (sched, cfg,                                              
+                                              &pl->id,
+                                              GNUNET_TIME_UNIT_ZERO,
+                                              GNUNET_TIME_UNIT_FOREVER_REL,
+                                              &whitelist_done,
+                                              pl);
+         pl->is_blocked = GNUNET_NO;
+       }
+      pl = pl->next;
     }
+}
+
+
+/**
+ * Function called by core when our attempt to connect succeeded.
+ */
+static void
+connect_completed_callback (void *cls,
+                           const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct PeerList *pos = cls;
+
+  pos->connect_req = NULL;
+}
+
+
+/**
+ * Try to connect to the specified peer.
+ *
+ * @param pos peer to connect to
+ */
+static void
+attempt_connect (struct PeerList *pos)
+{
   if (GNUNET_YES == pos->is_friend)
     pos->blacklisted_until = GNUNET_TIME_relative_to_absolute (BLACKLIST_AFTER_ATTEMPT_FRIEND);
   else
     pos->blacklisted_until = GNUNET_TIME_relative_to_absolute (BLACKLIST_AFTER_ATTEMPT);
-  GNUNET_CORE_notify_transmit_ready (handle,
-                                    0 /* priority */,
-                                    GNUNET_TIME_UNIT_MINUTES,
-                                    peer,
-                                    sizeof(struct GNUNET_MessageHeader),
-                                    &ready_callback,
-                                    NULL);
+#if DEBUG_TOPOLOGY
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Asking core to connect to `%s'\n",
+             GNUNET_i2s (&pos->id));
+#endif
+  pos->connect_req = GNUNET_CORE_peer_request_connect (sched, cfg,
+                                                      GNUNET_TIME_UNIT_MINUTES,
+                                                      &pos->id,
+                                                      &connect_completed_callback,
+                                                      pos);
 }
 
 
 /**
- * Is this peer one of our friends?
+ * Find a peer in our linked list.  
+ * FIXME: should probably use a hash map instead.
  */
-static int
-is_friend (const struct GNUNET_PeerIdentity * peer)
+struct PeerList *
+find_peer (const struct GNUNET_PeerIdentity * peer)
 {
   struct PeerList *pos;
 
-  pos = friends;
+  pos = peers;
   while (pos != NULL)
     {
-      if ( (GNUNET_YES == pos->is_friend) &&
-          (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity))) )
-       return GNUNET_YES;
+      if (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity)))
+       return pos;
       pos = pos->next;
     }
-  return GNUNET_NO;
+  return NULL;
 }
 
 
@@ -310,54 +418,288 @@ is_friend (const struct GNUNET_PeerIdentity * peer)
  * Check if an additional connection from the given peer is allowed.
  */
 static int
-is_connection_allowed (const struct GNUNET_PeerIdentity * peer)
+is_connection_allowed (struct PeerList *peer)
 {
-  if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
+  if (0 == memcmp (&my_identity, &peer->id, sizeof (struct GNUNET_PeerIdentity)))
     return GNUNET_SYSERR;       /* disallow connections to self */
-  if (is_friend (peer))
+  if (peer->is_friend)
     return GNUNET_OK;
   if (GNUNET_YES == friends_only)
-    return GNUNET_SYSERR;
+    {
+#if DEBUG_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Determined that `%s' is not allowed to connect (not a friend)\n",
+                 GNUNET_i2s (&peer->id));
+#endif       
+      return GNUNET_SYSERR;
+    }
   if (friend_count >= minimum_friend_count)
     return GNUNET_OK;
+#if DEBUG_TOPOLOGY
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Determined that `%s' is not allowed to connect (not enough connected friends)\n",
+             GNUNET_i2s (&peer->id));
+#endif       
   return GNUNET_SYSERR;
 }
 
 
+/**
+ * Create a new entry in the peer list.
+ *
+ * @param peer identity of the new entry
+ * @param hello hello message, can be NULL
+ * @param is_friend is the new entry for a friend?
+ * @return the new entry
+ */
+static struct PeerList *
+make_peer (const struct
+          GNUNET_PeerIdentity * peer,
+          const struct GNUNET_HELLO_Message *hello,
+          int is_friend)
+{
+  struct PeerList *ret;
+  
+  ret = GNUNET_malloc (sizeof (struct PeerList));
+  ret->id = *peer;
+  ret->is_friend = is_friend;
+  if (hello != NULL)
+    {
+      ret->hello = GNUNET_malloc (GNUNET_HELLO_size (hello));
+      memcpy (ret->hello, hello,
+             GNUNET_HELLO_size (hello));
+    }
+  ret->next = peers;
+  peers = ret;
+  return ret;
+}
+
+
+/**
+ * Free all resources associated with the given peer.
+ *
+ * @param peer peer to free
+ */
+static void
+free_peer (struct PeerList *peer)
+{
+  struct PeerList *pos;
+  struct PeerList *prev;
+  
+  prev = NULL;
+  pos = peers;
+  while (peer != pos)
+    {
+      prev = pos;
+      pos = pos->next;
+    }
+  GNUNET_assert (pos != NULL);
+   if (prev == NULL)
+     peers = pos->next;
+   else
+     prev->next = pos->next;
+   if (pos->hello_req != NULL)
+     GNUNET_CORE_notify_transmit_ready_cancel (pos->hello_req);
+   if (pos->wh != NULL)
+     GNUNET_TRANSPORT_blacklist_cancel (pos->wh);
+   if (pos->connect_req != NULL)
+     GNUNET_CORE_peer_request_connect_cancel (pos->connect_req);             
+   if (pos->hello_delay_task != GNUNET_SCHEDULER_NO_TASK)
+     GNUNET_SCHEDULER_cancel (sched,
+                             pos->hello_delay_task);
+   GNUNET_free_non_null (pos->hello);   
+   if (pos->filter != NULL)
+     GNUNET_CONTAINER_bloomfilter_free (peer->filter);
+   GNUNET_free (pos);
+}
+
+
+/**
+ * Setup bloom filter for the given peer entry.
+ *
+ * @param peer entry to initialize
+ */
+static void
+setup_filter (struct PeerList *peer)
+{
+  /* 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_load (NULL, 64, 5);
+  peer->filter_expiration = GNUNET_TIME_relative_to_absolute (HELLO_ADVERTISEMENT_MIN_REPEAT_FREQUENCY);
+  /* never send a peer its own HELLO */
+  GNUNET_CONTAINER_bloomfilter_add (peer->filter, &peer->id.hashPubKey);
+}
+
+
+/**
+ * Function to fill send buffer with HELLO.
+ *
+ * @param cls 'struct PeerList' of the target peer
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf
+ */
+static size_t
+hello_advertising_ready (void *cls,
+                        size_t size,
+                        void *buf);
+
+
+/**
+ * Calculate when we would like to send the next HELLO to this
+ * peer and ask for it.
+ *
+ * @param cls for which peer to schedule the HELLO
+ * @param tc task context
+ */
+static void
+schedule_next_hello (void *cls,
+                    const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct PeerList *pl = cls;
+  struct PeerList *pos;
+  struct PeerList *next;
+  uint16_t next_want;
+  struct GNUNET_TIME_Relative next_adv;
+  struct GNUNET_TIME_Relative rst_time;
+  
+  pl->hello_delay_task = GNUNET_SCHEDULER_NO_TASK;
+  if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
+    return; /* we're out of here */
+  next_want = 0;
+  next_adv = GNUNET_TIME_UNIT_FOREVER_REL;
+  /* find applicable HELLOs */
+  next = peers;
+  while (NULL != (pos = next))
+    {
+      next = pos->next;
+      if (pos->hello == NULL)
+       continue;
+      rst_time = GNUNET_TIME_absolute_get_remaining (pos->filter_expiration);
+      if (0 == rst_time.value)
+       {
+         /* time to discard... */
+         GNUNET_CONTAINER_bloomfilter_free (pos->filter);
+         setup_filter (pos);
+       }
+      else
+       {
+         if (rst_time.value < next_adv.value)
+           next_want = GNUNET_HELLO_size (pos->hello);
+         next_adv = GNUNET_TIME_relative_min (rst_time,
+                                              next_adv);         
+       }
+      if (GNUNET_NO ==
+         GNUNET_CONTAINER_bloomfilter_test (pos->filter,
+                                            &pl->id.hashPubKey))
+       break;
+    }
+  if (pos != NULL)  
+    next_adv = GNUNET_TIME_absolute_get_remaining (pl->next_hello_allowed);
+  if (next_adv.value == 0)
+    {
+      /* now! */
+      pl->hello_req = GNUNET_CORE_notify_transmit_ready (handle, 0,
+                                                        next_adv,
+                                                        &pl->id,
+                                                        next_want,
+                                                        &hello_advertising_ready,
+                                                        pl);
+      return;
+    }
+  pl->hello_delay_task 
+    = GNUNET_SCHEDULER_add_delayed (sched,
+                                   next_adv,
+                                   &schedule_next_hello,
+                                   pl);
+}
+
+
+/**
+ * Cancel existing requests for sending HELLOs to this peer
+ * and recalculate when we should send HELLOs to it based
+ * on our current state (something changed!).
+ */
+static void
+reschedule_hellos (struct PeerList *peer)
+{
+  if (peer->hello_req != NULL)
+    {
+      GNUNET_CORE_notify_transmit_ready_cancel (peer->hello_req);
+      peer->hello_req = NULL;
+    }
+   if (peer->hello_delay_task != GNUNET_SCHEDULER_NO_TASK)
+     {
+       GNUNET_SCHEDULER_cancel (sched,
+                               peer->hello_delay_task);
+       peer->hello_delay_task = GNUNET_SCHEDULER_NO_TASK;
+     }
+   peer->hello_delay_task 
+     = GNUNET_SCHEDULER_add_now (sched,
+                                &schedule_next_hello,
+                                peer);
+}
+
+
 /**
  * Method called whenever a peer connects.
  *
  * @param cls closure
  * @param peer peer identity this notification is about
+ * @param latency reported latency of the connection with 'other'
+ * @param distance reported distance (DV) to 'other' 
  */
-static void connect_notify (void *cls,
-                           const struct
-                           GNUNET_PeerIdentity * peer)
+static void 
+connect_notify (void *cls,
+               const struct
+               GNUNET_PeerIdentity * peer,
+               struct GNUNET_TIME_Relative latency,
+               uint32_t distance)
 {
   struct PeerList *pos;
 
+#if DEBUG_TOPOLOGY
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Core told us that we are connecting to `%s'\n",
+             GNUNET_i2s (peer));
+#endif
   connection_count++;
-  pos = friends;
-  while (pos != NULL)
+  pos = find_peer (peer);
+  if (pos == NULL)    
     {
-      if ( (GNUNET_YES == pos->is_friend) &&
-          (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity))) )
+      pos = make_peer (peer, NULL, GNUNET_NO);
+      if (GNUNET_OK != is_connection_allowed (pos))
        {
-         GNUNET_assert (GNUNET_NO == pos->is_connected);
+         GNUNET_assert (pos->is_friend == GNUNET_NO);
          pos->is_connected = GNUNET_YES;
-         pos->blacklisted_until.value = 0; /* remove blacklisting */
-         friend_count++;
+#if DEBUG_TOPOLOGY
+         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                     "Connection to `%s' is forbidden, forcing disconnect!\n",
+                     GNUNET_i2s (peer));
+#endif       
+         force_disconnect (pos);
          return;
        }
-      pos = pos->next;
     }
-  pos = GNUNET_malloc (sizeof(struct PeerList));
-  pos->id = *peer;
+  else
+    {
+      GNUNET_assert (GNUNET_NO == pos->is_connected);
+      pos->blacklisted_until.value = 0; /* remove blacklisting */
+    }
   pos->is_connected = GNUNET_YES;
-  pos->next = friends;
-  friends = pos;
-  if (GNUNET_OK != is_connection_allowed (peer))
-    force_disconnect (peer);
+  if (pos->is_friend)
+    {
+      if ( (friend_count == minimum_friend_count - 1) &&
+          (GNUNET_YES != friends_only) )       
+       whitelist_peers ();       
+      friend_count++;
+    }
+  reschedule_hellos (pos);
 }
 
 
@@ -369,13 +711,18 @@ drop_non_friends ()
 {
   struct PeerList *pos;
 
-  pos = friends;
+  pos = peers;
   while (pos != NULL)
     {
-      if (GNUNET_NO == pos->is_friend)
+      if ( (GNUNET_NO == pos->is_friend) &&
+          (GNUNET_YES == pos->is_connected) )
        {
-         GNUNET_assert (GNUNET_YES == pos->is_connected);
-         force_disconnect (&pos->id);
+#if DEBUG_TOPOLOGY
+         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                     "Connection to `%s' is not from a friend, forcing disconnect!\n",
+                     GNUNET_i2s (&pos->id));
+#endif       
+         force_disconnect (pos);
        }
       pos = pos->next;
     }
@@ -383,99 +730,82 @@ drop_non_friends ()
 
 
 /**
- * Method called whenever a peer disconnects.
- *
- * @param cls closure
- * @param peer peer identity this notification is about
+ * Try to add more peers to our connection set.
  */
-static void disconnect_notify (void *cls,
-                              const struct
-                              GNUNET_PeerIdentity * peer)
+static void
+try_add_peers ()
 {
   struct PeerList *pos;
-  struct PeerList *prev;
 
-  connection_count--;
-  pos = friends;
-  prev = NULL;
+  pos = peers;
   while (pos != NULL)
     {
-      if (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity)))
-       {
-         GNUNET_assert (GNUNET_YES == pos->is_connected);
-         pos->is_connected = GNUNET_NO;
-         if (GNUNET_YES == pos->is_friend)
-           {
-             friend_count--;
-             if (friend_count < minimum_friend_count)
-               {
-                 /* disconnect from all non-friends */
-                 drop_non_friends ();
-                 attempt_connect (peer, pos);
-               }
-           }
-         else
-           {
-             /* free entry */
-             if (prev == NULL)
-               friends = pos->next;
-             else
-               prev->next = pos->next;
-             GNUNET_free (pos);
-           }
-         return;
-       }
-      prev = pos;
+      if ( (GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value == 0) &&
+          ( (GNUNET_YES == pos->is_friend) ||
+            (friend_count >= minimum_friend_count) ) &&
+          (GNUNET_YES != pos->is_connected) )
+       attempt_connect (pos);
       pos = pos->next;
     }
-  GNUNET_break (0);
 }
 
 
 /**
- * Find more peers that we should connect to and ask the
- * core to establish connections.
- */
-static void
-find_more_peers (void *cls,
-                const struct GNUNET_SCHEDULER_TaskContext *tc);
-
-
-/**
- * Determine when we should try again to find more peers and
- * schedule the task.
+ * Method called whenever a peer disconnects.
+ *
+ * @param cls closure
+ * @param peer peer identity this notification is about
  */
-static void
-schedule_peer_search ()
+static void 
+disconnect_notify (void *cls,
+                  const struct
+                  GNUNET_PeerIdentity * peer)
 {
-  struct GNUNET_TIME_Relative delay;
-
-  /* Typically, we try again every 15 minutes; the minimum period is
-     15s; if we are above the connection target, we reduce re-trying
-     by the square of how much we are above; so for example, with 200%
-     of the connection target we would only look for more peers once
-     every hour (after all, we're quite busy processing twice as many
-     connections as we intended to have); similarly, if we are at only
-     25% of our connectivity goal, we will try 16x as hard to connect
-     (so roughly once a minute, plus the 15s minimum delay */
-  delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
-                                        15 + 15 * 60 * connection_count * connection_count / target_connection_count / target_connection_count);
-  GNUNET_SCHEDULER_add_delayed (sched,
-                               GNUNET_NO,
-                               GNUNET_SCHEDULER_PRIORITY_DEFAULT,
-                               GNUNET_SCHEDULER_NO_TASK,
-                               delay,
-                               &find_more_peers,
-                               NULL);
+  struct PeerList *pos;
+#if DEBUG_TOPOLOGY
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Core told us that we disconnected from `%s'\n",
+             GNUNET_i2s (peer));
+#endif       
+  pos = find_peer (peer);
+  if (pos == NULL)
+    {
+      GNUNET_break (0);
+      return;
+    }
+  if (pos->is_connected != GNUNET_YES)
+    {
+      GNUNET_break (0);
+      return;
+    }
+  connection_count--;
+  if (pos->is_friend)
+    friend_count--; 
+  if ( (connection_count < target_connection_count) ||
+       (friend_count < minimum_friend_count) )
+    try_add_peers ();   
+  if (friend_count < minimum_friend_count)
+    {
+      /* disconnect from all non-friends */
+#if DEBUG_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Not enough friendly connections, dropping all non-friend connections\n");
+#endif       
+      drop_non_friends ();
+    }
 }
 
 
-
-
 /**
  * Iterator called on each address.
  *
- * @param cls flag that we will set if we see any addresses.
+ * @param cls flag that we will set if we see any addresses
+ * @param tname name of the transport
+ * @param expiration when will the given address expire
+ * @param addr the address of the peer
+ * @param addrlen number of bytes in addr
+ * @return GNUNET_SYSERR always, to terminate iteration
  */
 static int
 address_iterator (void *cls,
@@ -490,15 +820,16 @@ address_iterator (void *cls,
 
 
 /**
- * We've gotten a HELLO from another peer.
- * Consider it for advertising.
+ * We've gotten a HELLO from another peer.  Consider it for
+ * advertising.
  */
 static void
 consider_for_advertising (const struct GNUNET_HELLO_Message *hello)
 {
   int have_address;
   struct GNUNET_PeerIdentity pid;
-  struct HelloList *pos;
+  struct PeerList *peer;
+  struct PeerList *pos;
   uint16_t size;
 
   have_address = GNUNET_NO;
@@ -508,40 +839,43 @@ consider_for_advertising (const struct GNUNET_HELLO_Message *hello)
                                  &have_address);
   if (GNUNET_NO == have_address)
     return; /* no point in advertising this one... */
-  GNUNET_HELLO_get_id (hello, &pid);
-  pos = hellos;
-  while (pos != NULL)
+  GNUNET_break (GNUNET_OK == GNUNET_HELLO_get_id (hello, &pid));
+  peer = find_peer (&pid);
+  if (peer == NULL)
+    peer = make_peer (&pid, hello, GNUNET_NO);
+  // FIXME: check if 'hello' is any different from peer->hello?
+#if DEBUG_TOPOLOGY
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Found `%s' from peer `%s' for advertising\n",
+             "HELLO",
+             GNUNET_i2s (&pid));
+#endif 
+  size = GNUNET_HELLO_size (hello);
+  GNUNET_free_non_null (peer->hello);
+  peer->hello = GNUNET_malloc (size);
+  memcpy (peer->hello, hello, size);
+  if (peer->filter != NULL)
+    GNUNET_CONTAINER_bloomfilter_free (peer->filter);
+  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! */
+  pos = peers;
+  while (NULL != pos)
     {
-      if (0 == memcmp (&pos->id,
-                      &pid,
-                      sizeof(struct GNUNET_PeerIdentity)))
-       return; /* duplicate, at least "mostly" */
+      if (pos != peer) 
+       {
+         if ( (pos->is_connected) &&
+              (GNUNET_TIME_absolute_get_remaining (pos->next_hello_allowed).value <= HELLO_ADVERTISEMENT_MIN_FREQUENCY.value) )
+           reschedule_hellos (pos);    
+       }
       pos = pos->next;
     }
-  size = GNUNET_HELLO_size (hello);
-  pos = GNUNET_malloc (sizeof(struct HelloList) + size);
-  pos->msg = (struct GNUNET_HELLO_Message*) &pos[1];
-  memcpy (&pos->msg, hello, size);
-  pos->id = pid;
-  pos->expiration = GNUNET_TIME_relative_to_absolute (HELLO_ADVERTISEMENT_MIN_FREQUENCY);
-  /* 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. */
-  pos->filter = GNUNET_CONTAINER_bloomfilter_load (NULL, 64, 5);
-  /* never send a peer its own HELLO */
-  GNUNET_CONTAINER_bloomfilter_add (pos->filter, &pos->id.hashPubKey);
-  pos->next = hellos;
-  hellos = pos;
 }
 
 
 /**
- * Peerinfo calls this function to let us know about a
- * possible peer that we might want to connect to.
+ * Peerinfo calls this function to let us know about a possible peer
+ * that we might want to connect to.
  */
 static void
 process_peer (void *cls,
@@ -551,64 +885,59 @@ process_peer (void *cls,
 {
   struct PeerList *pos;
 
-  if (peer == NULL)
-    {
-      /* last call, schedule 'find_more_peers' again... */
-      schedule_peer_search ();
-      return;
-    }
-  if (hello == NULL)
-    {
-      /* no HELLO known; can not connect, ignore! */
-      return;
-    }
+  GNUNET_assert (peer != NULL);
   if (0 == memcmp (&my_identity,
                    peer, sizeof (struct GNUNET_PeerIdentity)))
     return;  /* that's me! */
-
-  consider_for_advertising (hello);
-  pos = friends;
-  while (pos != NULL)
+  if (hello == NULL)
     {
-      if (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity)))
+      /* free existing HELLO, if any */
+      if (NULL != (pos = find_peer (peer)))
        {
-         if (GNUNET_YES == pos->is_connected)
-           return;
-         if (GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value > 0)
-           return; /* peer still blacklisted */
-         if (GNUNET_YES == pos->is_friend)
+         GNUNET_free_non_null (pos->hello);
+         pos->hello = NULL;
+         if (pos->filter != NULL)
            {
-             attempt_connect (peer, pos);
-             return;
+             GNUNET_CONTAINER_bloomfilter_free (pos->filter);
+             pos->filter = NULL;
            }
+         if ( (! pos->is_connected) &&
+              (! pos->is_friend) &&
+              (0 == GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value) )
+           free_peer (pos);
        }
-      pos = pos->next;
+      return;
     }
-  if (GNUNET_YES == friends_only)
-    return;
-  if (friend_count < minimum_friend_count)
-    return;
-  attempt_connect (peer, NULL);
-}
-
-
-/**
- * Try to add more friends to our connection set.
- */
-static void
-try_add_friends ()
-{
-  struct PeerList *pos;
-
-  pos = friends;
-  while (pos != NULL)
+  consider_for_advertising (hello);
+  pos = find_peer (peer);  
+  GNUNET_assert (NULL != pos);
+#if DEBUG_TOPOLOGY
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Considering connecting to peer `%s'\n",
+             GNUNET_i2s (peer));
+#endif 
+  if (GNUNET_YES == pos->is_connected)
     {
-      if ( (GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value == 0) &&
-          (GNUNET_YES == pos->is_friend) &&
-          (GNUNET_YES != pos->is_connected) )
-       attempt_connect (&pos->id, pos);
-      pos = pos->next;
+#if DEBUG_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Already connected to peer `%s'\n",
+                 GNUNET_i2s (peer));
+#endif 
+      return;
+    }
+  if (GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value > 0)
+    {
+#if DEBUG_TOPOLOGY
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Already tried peer `%s' recently\n",
+                 GNUNET_i2s (peer));
+#endif 
+      return; /* peer still blacklisted */
     }
+  if ( (GNUNET_YES == pos->is_friend) ||
+       (GNUNET_YES != friends_only) ||    
+       (friend_count >= minimum_friend_count) )
+    attempt_connect (pos);
 }
 
 
@@ -617,62 +946,28 @@ try_add_friends ()
  * where the blacklisting has expired.
  */
 static void
-discard_old_blacklist_entries ()
+discard_old_blacklist_entries (void *cls,
+                              const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
   struct PeerList *pos;
   struct PeerList *next;
-  struct PeerList *prev;
 
-  next = friends;
-  prev = NULL;
+  if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
+    return;
+  next = peers;
   while (NULL != (pos = next))
     {
       next = pos->next;
       if ( (GNUNET_NO == pos->is_friend) &&
           (GNUNET_NO == pos->is_connected) &&
+          (GNUNET_NO == pos->is_blocked) &&
           (0 == GNUNET_TIME_absolute_get_remaining (pos->blacklisted_until).value) )
-       {
-         /* delete 'pos' from list */
-         if (prev == NULL)
-           friends = next;
-         else
-           prev->next = next;
-         GNUNET_free (pos);
-       }
-      else
-       {
-         prev = pos;
-       }
+       free_peer (pos);
     }
-}
-
-
-/**
- * Find more peers that we should connect to and ask the
- * core to establish connections.
- */
-static void
-find_more_peers (void *cls,
-                const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
-  discard_old_blacklist_entries ();
-  if (target_connection_count <= connection_count)
-    {
-      schedule_peer_search ();
-      return;
-    }
-  if ( (GNUNET_YES == friends_only) ||
-       (friend_count < minimum_friend_count) )
-    {
-      try_add_friends ();
-      schedule_peer_search ();
-      return;
-    }
-  GNUNET_PEERINFO_for_all (cfg,
-                          sched,
-                          NULL,
-                          0, GNUNET_TIME_UNIT_FOREVER_REL,
-                          &process_peer, NULL);
+  GNUNET_SCHEDULER_add_delayed (sched,
+                               BLACKLIST_AFTER_ATTEMPT,
+                               &discard_old_blacklist_entries,
+                               NULL);
 }
 
 
@@ -698,29 +993,23 @@ core_init (void *cls,
     {
       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                  _("Failed to connect to core service, can not manage topology!\n"));
+      GNUNET_SCHEDULER_shutdown (sched);
       return;
     }
   handle = server;
   my_identity = *my_id;
-  if (autoconnect)
-    GNUNET_SCHEDULER_add_delayed (sched,
-                                 GNUNET_NO,
-                                 GNUNET_SCHEDULER_PRIORITY_DEFAULT,
-                                 GNUNET_SCHEDULER_NO_TASK,
-                                 GNUNET_TIME_UNIT_SECONDS /* give core time to tell us about existing connections */,
-                                 &find_more_peers,
-                                 NULL);
+#if DEBUG_TOPOLOGY
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "I am peer `%s'\n",
+             GNUNET_i2s (my_id));
+#endif         
+  GNUNET_SCHEDULER_add_delayed (sched,
+                               BLACKLIST_AFTER_ATTEMPT,
+                               &discard_old_blacklist_entries,
+                               NULL);
 }
 
 
-/**
- * gnunet-daemon-topology command line options.
- */
-static struct GNUNET_GETOPT_CommandLineOption options[] = {
-  GNUNET_GETOPT_OPTION_END
-};
-
-
 /**
  * Read the friends file.
  */
@@ -730,17 +1019,24 @@ read_friends_file (const struct GNUNET_CONFIGURATION_Handle *cfg)
   char *fn;
   char *data;
   size_t pos;
-  GNUNET_HashCode hc;
+  struct GNUNET_PeerIdentity pid;
   struct stat frstat;
   struct GNUNET_CRYPTO_HashAsciiEncoded enc;
   unsigned int entries_found;
   struct PeerList *fl;
 
-  fn = NULL;
-  GNUNET_CONFIGURATION_get_value_filename (cfg,
-                                          "TOPOLOGY",
-                                          "FRIENDS",
-                                          &fn);
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_filename (cfg,
+                                              "TOPOLOGY",
+                                              "FRIENDS",
+                                              &fn))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                 _("Option `%s' in section `%s' not specified!\n"),
+                 "FRIENDS",
+                 "TOPOLOGY");
+      return;
+    }
   if (GNUNET_OK != GNUNET_DISK_file_test (fn))
     GNUNET_DISK_fn_write (fn, NULL, 0, GNUNET_DISK_PERM_USER_READ
         | GNUNET_DISK_PERM_USER_WRITE);
@@ -791,7 +1087,7 @@ read_friends_file (const struct GNUNET_CONFIGURATION_Handle *cfg)
          continue;
        }
       enc.encoding[sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded) - 1] = '\0';
-      if (GNUNET_OK != GNUNET_CRYPTO_hash_from_string ((char *) &enc, &hc))
+      if (GNUNET_OK != GNUNET_CRYPTO_hash_from_string ((char *) &enc, &pid.hashPubKey))
        {
          GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                      _("Syntax error in topology specification at offset %llu, skipping bytes `%s'.\n"),
@@ -801,11 +1097,12 @@ read_friends_file (const struct GNUNET_CONFIGURATION_Handle *cfg)
       else
        {
          entries_found++;
-         fl = GNUNET_malloc (sizeof(struct PeerList));
-         fl->is_friend = GNUNET_YES;
-         fl->id.hashPubKey = hc;
-         fl->next = friends;
-         friends = fl;
+         fl = make_peer (&pid,
+                         NULL,
+                         GNUNET_YES);
+         GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                     _("Found friend `%s' in configuration\n"),
+                     GNUNET_i2s (&fl->id));
        }
       pos = pos + sizeof (struct GNUNET_CRYPTO_HashAsciiEncoded);
       while ((pos < frstat.st_size) && isspace (data[pos]))
@@ -833,9 +1130,11 @@ read_friends_file (const struct GNUNET_CONFIGURATION_Handle *cfg)
  * received.
  *
  * @param cls closure
- * @param peer the other peer involved (sender or receiver, NULL
+ * @param other the other peer involved (sender or receiver, NULL
  *        for loopback messages where we are both sender and receiver)
  * @param message the actual HELLO message
+ * @param latency reported latency of the connection with 'other'
+ * @param distance reported distance (DV) to 'other' 
  * @return GNUNET_OK to keep the connection open,
  *         GNUNET_SYSERR to close it (signal serious error)
  */
@@ -843,8 +1142,16 @@ static int
 handle_encrypted_hello (void *cls,
                        const struct GNUNET_PeerIdentity * other,
                        const struct GNUNET_MessageHeader *
-                       message)
+                       message,
+                       struct GNUNET_TIME_Relative latency,
+                       uint32_t distance)
 {
+#if DEBUG_TOPOLOGY
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Received encrypted `%s' from peer `%s'",
+             "HELLO",
+             GNUNET_i2s (other));
+#endif         
   if (transport != NULL)
     GNUNET_TRANSPORT_offer_hello (transport,
                                  message);
@@ -852,114 +1159,74 @@ handle_encrypted_hello (void *cls,
 }
 
 
-/**
- * Peerinfo calls this function to let us know about a
- * possible peer that we might want to connect to.
- */
-static void
-gather_hello_callback (void *cls,
-                      const struct GNUNET_PeerIdentity *peer,
-                      const struct GNUNET_HELLO_Message *hello,
-                      uint32_t trust)
-{
-  if (peer == NULL)
-    {
-      hello_gathering_active = GNUNET_NO;
-      return;
-    }
-  if (hello != NULL)
-    consider_for_advertising (hello);
-}
-
-
 /**
  * Function to fill send buffer with HELLO.
  *
- * @param receiver the receiver of the message
- * @param position is the reference to the
- *        first unused position in the buffer where GNUnet is building
- *        the message
- * @param padding is the number of bytes left in that buffer.
- * @return the number of bytes written to
- *   that buffer (must be a positive number).
+ * @param cls 'struct PeerList' of the target peer
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf
  */
-static unsigned int
-hello_advertising (void *cls,
-                  const struct GNUNET_PeerIdentity *
-                  receiver,
-                  void *position, unsigned int padding)
+static size_t
+hello_advertising_ready (void *cls,
+                        size_t size,
+                        void *buf)
 {
-  struct PeerList *pl;
-  struct HelloList *pos;
-  struct HelloList *prev;
-  struct HelloList *next;
-  uint16_t size;
-
-  pl = friends;
-  while (pl != NULL)
-    {
-      if (0 == memcmp (&pl->id, receiver, sizeof (struct GNUNET_PeerIdentity)))
-       break;
-      pl = pl->next;
-    }
-  if (pl == NULL)
-    {
-      GNUNET_break (0);
-      return 0;
-    }
+  struct PeerList *pl = cls;
+  struct PeerList *pos; 
+  struct PeerList *next;
+  uint16_t want;
+  size_t hs;
+
+  pl->hello_req = NULL;
+#if DEBUG_TOPOLOGY
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Data solicited for `%s', considering sending `%s'",
+             GNUNET_i2s (&pl->id),
+             "HELLO");
+#endif         
   /* find applicable HELLOs */
-  prev = NULL;
-  next = hellos;
+  next = peers;
   while (NULL != (pos = next))
     {
       next = pos->next;
-      if (GNUNET_NO ==
-         GNUNET_CONTAINER_bloomfilter_test (pos->filter,
-                                            &receiver->hashPubKey))
-       break;
-      if (0 == GNUNET_TIME_absolute_get_remaining (pos->expiration).value)
+      if (pos->hello == NULL)
+       continue;
+      if (0 == GNUNET_TIME_absolute_get_remaining (pos->filter_expiration).value)
        {
          /* time to discard... */
-         if (prev == NULL)
-           prev->next = next;
-         else
-           hellos = next;
          GNUNET_CONTAINER_bloomfilter_free (pos->filter);
-         GNUNET_free (pos);
-       }
-      else
-       {
-         prev = pos;
+         setup_filter (pos);
        }
+      if (GNUNET_NO ==
+         GNUNET_CONTAINER_bloomfilter_test (pos->filter,
+                                            &pl->id.hashPubKey))
+       break;
     }
+  want = 0;
   if (pos != NULL)
     {
-      size = GNUNET_HELLO_size (pos->msg);
-      if (size < padding)
+      hs = GNUNET_HELLO_size (pos->hello);
+      if (hs < size)
        {
-         memcpy (position, pos->msg, size);
+         want = hs;
+         memcpy (buf, pos->hello, want);
          GNUNET_CONTAINER_bloomfilter_add (pos->filter,
-                                           &receiver->hashPubKey);
-       }
-      else
-       {
-         size = 0;
+                                           &pl->id.hashPubKey);
+         pl->next_hello_allowed = GNUNET_TIME_relative_to_absolute (HELLO_ADVERTISEMENT_MIN_FREQUENCY);
+#if DEBUG_TOPOLOGY
+         GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                     "Sending %u bytes of `%s's",
+                     (unsigned int) want,
+                     "HELLO");
+#endif         
        }
-      return size;
-    }
-  if ( (GNUNET_NO == hello_gathering_active) &&
-       (GNUNET_TIME_absolute_get_duration (last_hello_gather_time).value >
-       MIN_HELLO_GATHER_DELAY.value) )
-    {
-      hello_gathering_active = GNUNET_YES;
-      last_hello_gather_time = GNUNET_TIME_absolute_get();
-      GNUNET_PEERINFO_for_all (cfg,
-                              sched,
-                              NULL,
-                              0, GNUNET_TIME_UNIT_FOREVER_REL,
-                              &gather_hello_callback, NULL);
     }
-  return 0;
+  pl->hello_delay_task 
+    = GNUNET_SCHEDULER_add_now (sched,
+                               &schedule_next_hello,
+                               pl);
+  return want;
 }
 
 
@@ -970,16 +1237,29 @@ hello_advertising (void *cls,
 static void
 cleaning_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
-  struct PeerList *pl;
+  struct DisconnectList *dl;
 
+  if (NULL != peerinfo_notify)
+    {
+      GNUNET_PEERINFO_notify_cancel (peerinfo_notify);
+      peerinfo_notify = NULL;
+    }
   GNUNET_TRANSPORT_disconnect (transport);
   transport = NULL;
-  GNUNET_CORE_disconnect (handle);
-  handle = NULL;
-  while (NULL != (pl = friends))
+  while (NULL != peers)
+    free_peer (peers);     
+  if (handle != NULL)
     {
-      friends = pl->next;
-      GNUNET_free (pl);
+      GNUNET_CORE_disconnect (handle);
+      handle = NULL;
+    }
+  while (NULL != (dl = disconnect_head))
+    {
+      GNUNET_CONTAINER_DLL_remove (disconnect_head,
+                                  disconnect_tail,
+                                  dl);
+      GNUNET_TRANSPORT_blacklist_cancel (dl->rh);
+      GNUNET_free (dl);
     }
 }
 
@@ -1015,50 +1295,81 @@ run (void *cls,
   friends_only = GNUNET_CONFIGURATION_get_value_yesno (cfg,
                                                       "TOPOLOGY",
                                                       "FRIENDS-ONLY");
-  opt = 0;
-  GNUNET_CONFIGURATION_get_value_number (cfg,
-                                        "TOPOLOGY",
-                                        "MINIMUM-FRIENDS",
-                                        &opt);
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_number (cfg,
+                                            "TOPOLOGY",
+                                            "MINIMUM-FRIENDS",
+                                            &opt))
+    opt = 0;
   minimum_friend_count = (unsigned int) opt;
-  opt = 16;
-  GNUNET_CONFIGURATION_get_value_number (cfg,
-                                        "TOPOLOGY",
-                                        "TARGET-CONNECTION-COUNT",
-                                        &opt);
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_number (cfg,
+                                            "TOPOLOGY",
+                                            "TARGET-CONNECTION-COUNT",
+                                            &opt))
+    opt = 16;
   target_connection_count = (unsigned int) opt;
 
   if ( (friends_only == GNUNET_YES) ||
        (minimum_friend_count > 0) )
     read_friends_file (cfg);
-
+#if DEBUG_TOPOLOGY
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Topology would like %u connections with at least %u friends (%s)\n",
+             target_connection_count,
+             minimum_friend_count,
+             autoconnect ? "autoconnect enabled" : "autoconnect disabled");
+#endif       
   transport = GNUNET_TRANSPORT_connect (sched,
                                        cfg,
                                        NULL,
                                        NULL,
                                        NULL,
                                        NULL);
-  GNUNET_CORE_connect (sched,
-                      cfg,
-                      GNUNET_TIME_UNIT_FOREVER_REL,
-                      NULL,
-                      &core_init,
-                      &connect_notify,
-                      &disconnect_notify,
-                      &hello_advertising,
-                      NULL, GNUNET_NO,
-                      NULL, GNUNET_NO,
-                      handlers);
-
+  handle = GNUNET_CORE_connect (sched,
+                               cfg,
+                               GNUNET_TIME_UNIT_FOREVER_REL,
+                               NULL,
+                               &core_init,
+                               NULL,
+                               &connect_notify,
+                               &disconnect_notify,
+                               NULL, GNUNET_NO,
+                               NULL, GNUNET_NO,
+                               handlers);
   GNUNET_SCHEDULER_add_delayed (sched,
-                                GNUNET_YES,
-                                GNUNET_SCHEDULER_PRIORITY_IDLE,
-                                GNUNET_SCHEDULER_NO_TASK,
                                 GNUNET_TIME_UNIT_FOREVER_REL,
                                 &cleaning_task, NULL);
+  if (NULL == transport)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                 _("Failed to connect to `%s' service.\n"),
+                 "transport");
+      GNUNET_SCHEDULER_shutdown (sched);
+      return;
+    }
+  if (NULL == handle)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                 _("Failed to connect to `%s' service.\n"),
+                 "core");
+      GNUNET_SCHEDULER_shutdown (sched);
+      return;
+    }
+  peerinfo_notify = GNUNET_PEERINFO_notify (cfg, sched,
+                                           &process_peer,
+                                           NULL);
 }
 
 
+/**
+ * gnunet-daemon-topology command line options.
+ */
+static struct GNUNET_GETOPT_CommandLineOption options[] = {
+  GNUNET_GETOPT_OPTION_END
+};
+
+
 /**
  * The main function for the topology daemon.
  *