path: root/src/dv/gnunet-service-dv.c

/*
     This file is part of GNUnet.
     (C) 2009 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
     by the Free Software Foundation; either version 3, 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
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/

/**
 * @file dv/gnunet-service-dv.c
 * @brief the distance vector service, primarily handles gossip of nearby
 * peers and sending/receiving DV messages from core and decapsulating
 * them
 *
 * @author Christian Grothoff
 * @author Nathan Evans
 *
 */
#include "platform.h"
#include "gnunet_client_lib.h"
#include "gnunet_getopt_lib.h"
#include "gnunet_os_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_service_lib.h"
#include "gnunet_core_service.h"
#include "gnunet_signal_lib.h"
#include "gnunet_util_lib.h"
#include "gnunet_hello_lib.h"
#include "gnunet_peerinfo_service.h"
#include "gnunet_crypto_lib.h"
#include "gnunet_statistics_service.h"
#include "dv.h"

/**
 * For testing mostly, remember only the
 * shortest path to a distant neighbor.
 */
#define AT_MOST_ONE GNUNET_NO

#define USE_PEER_ID GNUNET_YES

/**
 * How many outstanding messages (unknown sender) will we allow per peer?
 */
#define MAX_OUTSTANDING_MESSAGES 5

/**
 * How often do we check about sending out more peer information (if
 * we are connected to no peers previously).
 */
#define GNUNET_DV_DEFAULT_SEND_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 500000)

/**
 * How long do we wait at most between sending out information?
 */
#define GNUNET_DV_MAX_SEND_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 500000)

/**
 * How long can we have not heard from a peer and
 * still have it in our tables?
 */
#define GNUNET_DV_PEER_EXPIRATION_TIME GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 1000))

/**
 * Priority for gossip.
 */
#define GNUNET_DV_DHT_GOSSIP_PRIORITY (GNUNET_EXTREME_PRIORITY / 10)

/**
 * How often should we check if expiration time has elapsed for
 * some peer?
 */
#define GNUNET_DV_MAINTAIN_FREQUENCY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5))

/**
 * How long to allow a message to be delayed?
 */
#define DV_DELAY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5))

/**
 * Priority to use for DV data messages.
 */
#define DV_PRIORITY 0

/**
 * The cost to a direct neighbor.  We used to use 0, but 1 makes more sense.
 */
#define DIRECT_NEIGHBOR_COST 1

/**
 * The default number of direct connections to store in DV (max)
 */
#define DEFAULT_DIRECT_CONNECTIONS 50

/**
 * The default size of direct + extended peers in DV (max)
 */
#define DEFAULT_DV_SIZE 100

/**
 * The default fisheye depth, from how many hops away will
 * we keep peers?
 */
#define DEFAULT_FISHEYE_DEPTH 4

/**
 * Linked list of messages to send to clients.
 */
struct PendingMessage
{
  /**
   * Pointer to next item in the list
   */
  struct PendingMessage *next;

  /**
   * Pointer to previous item in the list
   */
  struct PendingMessage *prev;

  /**
   * The PeerIdentity to send to
   */
  struct GNUNET_PeerIdentity recipient;

  /**
   * The result of message sending.
   */
  struct GNUNET_DV_SendResultMessage *send_result;

  /**
   * Message importance level.
   */
  unsigned int importance;

  /**
   * Size of message.
   */
  unsigned int msg_size;

  /**
   * How long to wait before sending message.
   */
  struct GNUNET_TIME_Relative timeout;

  /**
   * Actual message to be sent; // avoid allocation
   */
  const struct GNUNET_MessageHeader *msg;       // msg = (cast) &pm[1]; // memcpy (&pm[1], data, len);

};

struct FastGossipNeighborList
{
  /**
   * Next element of DLL
   */
  struct FastGossipNeighborList *next;

  /**
   * Prev element of DLL
   */
  struct FastGossipNeighborList *prev;

  /**
   * The neighbor to gossip about
   */
  struct DistantNeighbor *about;
};

/**
 * Context created whenever a direct peer connects to us,
 * used to gossip other peers to it.
 */
struct NeighborSendContext
{
  /**
   * The peer we will gossip to.
   */
  struct DirectNeighbor *toNeighbor;

  /**
   * The task associated with this context.
   */
  GNUNET_SCHEDULER_TaskIdentifier task;

  /**
   * Head of DLL of peers to gossip about
   * as fast as possible to this peer, for initial
   * set up.
   */
  struct FastGossipNeighborList *fast_gossip_list_head;

  /**
   * Tail of DLL of peers to gossip about
   * as fast as possible to this peer, for initial
   * set up.
   */
  struct FastGossipNeighborList *fast_gossip_list_tail;

};


/**
 * Struct to hold information for updating existing neighbors
 */
struct NeighborUpdateInfo
{
  /**
   * Cost
   */
  unsigned int cost;

  /**
   * The existing neighbor
   */
  struct DistantNeighbor *neighbor;

  /**
   * The referrer of the possibly existing peer
   */
  struct DirectNeighbor *referrer;

  /**
   * The time we heard about this peer
   */
  struct GNUNET_TIME_Absolute now;

  /**
   * Peer id this peer uses to refer to neighbor.
   */
  unsigned int referrer_peer_id;

};

/**
 * Struct to store a single message received with
 * an unknown sender.
 */
struct UnknownSenderMessage
{
  /**
   * Message sender (immediate)
   */
  struct GNUNET_PeerIdentity sender;

  /**
   * The actual message received
   */
  struct GNUNET_MessageHeader *message;

  /**
   * Latency of connection
   */
  struct GNUNET_TIME_Relative latency;

  /**
   * Distance to destination
   */
  uint32_t distance;

  /**
   * Unknown sender id
   */
  uint32_t sender_id;
};

/**
 * Struct where actual neighbor information is stored,
 * referenced by min_heap and max_heap.  Freeing dealt
 * with when items removed from hashmap.
 */
struct DirectNeighbor
{
  /**
   * Identity of neighbor.
   */
  struct GNUNET_PeerIdentity identity;

  /**
   * PublicKey of neighbor.
   */
  struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pkey;

  /**
   * Head of DLL of nodes that this direct neighbor referred to us.
   */
  struct DistantNeighbor *referee_head;

  /**
   * Tail of DLL of nodes that this direct neighbor referred to us.
   */
  struct DistantNeighbor *referee_tail;

  /**
   * The sending context for gossiping peers to this neighbor.
   */
  struct NeighborSendContext *send_context;

  /**
   * Is this one of the direct neighbors that we are "hiding"
   * from DV?
   */
  int hidden;

  /**
   * Save messages immediately from this direct neighbor from a
   * distan peer we don't know on the chance that it will be
   * gossiped about and we can deliver the message.
   */
  struct UnknownSenderMessage pending_messages[MAX_OUTSTANDING_MESSAGES];
};


/**
 * Struct where actual neighbor information is stored,
 * referenced by min_heap and max_heap.  Freeing dealt
 * with when items removed from hashmap.
 */
struct DistantNeighbor
{
  /**
   * We keep distant neighbor's of the same referrer in a DLL.
   */
  struct DistantNeighbor *next;

  /**
   * We keep distant neighbor's of the same referrer in a DLL.
   */
  struct DistantNeighbor *prev;

  /**
   * Node in min heap
   */
  struct GNUNET_CONTAINER_HeapNode *min_loc;

  /**
   * Node in max heap
   */
  struct GNUNET_CONTAINER_HeapNode *max_loc;

  /**
   * Identity of referrer (next hop towards 'neighbor').
   */
  struct DirectNeighbor *referrer;

  /**
   * Identity of neighbor.
   */
  struct GNUNET_PeerIdentity identity;

  /**
   * PublicKey of neighbor.
   */
  struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pkey;

  /**
   * Last time we received routing information from this peer
   */
  struct GNUNET_TIME_Absolute last_activity;

  /**
   * Last time we sent routing information about this peer
   */
  struct GNUNET_TIME_Absolute last_gossip;

  /**
   * Cost to neighbor, used for actual distance vector computations
   */
  unsigned int cost;

  /**
   * Random identifier *we* use for this peer, to be used as shortcut
   * instead of sending full peer id for each message
   */
  unsigned int our_id;

  /**
   * Random identifier the *referrer* uses for this peer.
   */
  unsigned int referrer_id;

  /**
   * Is this one of the direct neighbors that we are "hiding"
   * from DV?
   */
  int hidden;

};

struct PeerIteratorContext
{
  /**
   * The actual context, to be freed later.
   */
  struct GNUNET_PEERINFO_IteratorContext *ic;

  /**
   * The neighbor about which we are concerned.
   */
  struct DirectNeighbor *neighbor;

  /**
   * The distant neighbor entry for this direct neighbor.
   */
  struct DistantNeighbor *distant;

};

/**
 * Context used for creating hello messages when
 * gossips are received.
 */
struct HelloContext
{
  /**
   * Identity of distant neighbor.
   */
  struct GNUNET_PeerIdentity distant_peer;

  /**
   * Identity of direct neighbor, via which we send this message.
   */
  const struct GNUNET_PeerIdentity *direct_peer;

  /**
   * How many addresses do we need to add (always starts at 1, then set to 0)
   */
  int addresses_to_add;

};

struct DV_SendContext
{
  /**
   * The distant peer (should always match)
   */
  struct GNUNET_PeerIdentity *distant_peer;

  /**
   * The direct peer, we need to verify the referrer of.
   */
  struct GNUNET_PeerIdentity *direct_peer;

  /**
   * The message to be sent
   */
  struct GNUNET_MessageHeader *message;

  /**
   * The pre-built send result message.  Simply needs to be queued
   * and freed once send has been called!
   */
  struct GNUNET_DV_SendResultMessage *send_result;

  /**
   * The size of the message being sent, may be larger
   * than message->header.size because it's multiple
   * messages packed into one!
   */
  size_t message_size;

  /**
   * How important is this message?
   */
  unsigned int importance;

  /**
   * Timeout for this message
   */
  struct GNUNET_TIME_Relative timeout;

  /**
   * Unique ID for DV message
   */
  unsigned int uid;
};

struct FindDestinationContext
{
  unsigned int tid;
  struct DistantNeighbor *dest;
};

struct FindIDContext
{
  unsigned int tid;
  struct GNUNET_PeerIdentity *dest;
  const struct GNUNET_PeerIdentity *via;
};

struct DisconnectContext
{
  /**
   * Distant neighbor to get pid from.
   */
  struct DistantNeighbor *distant;

  /**
   * Direct neighbor that disconnected.
   */
  struct DirectNeighbor *direct;
};

struct TokenizedMessageContext
{
  /**
   * Immediate sender of this message
   */
  const struct GNUNET_PeerIdentity *peer;

  /**
   * Distant sender of the message
   */
  struct DistantNeighbor *distant;

  /**
   * Uid for this set of messages
   */
  uint32_t uid;
};

/**
 * Context for finding the least cost peer to send to.
 * Transport selection can only go so far.
 */
struct FindLeastCostContext
{
  struct DistantNeighbor *target;
  unsigned int least_cost;
};

/**
 * Handle to the core service api.
 */
static struct GNUNET_CORE_Handle *coreAPI;

/**
 * Stream tokenizer to handle messages coming in from core.
 */
static struct GNUNET_SERVER_MessageStreamTokenizer *coreMST;

/**
 * The identity of our peer.
 */
static struct GNUNET_PeerIdentity my_identity;

/**
 * The configuration for this service.
 */
static const struct GNUNET_CONFIGURATION_Handle *cfg;


/**
 * The client, the DV plugin connected to us.  Hopefully
 * this client will never change, although if the plugin dies
 * and returns for some reason it may happen.
 */
static struct GNUNET_SERVER_Client *client_handle;

/**
 * Task to run when we shut down, cleaning up all our trash
 */
static GNUNET_SCHEDULER_TaskIdentifier cleanup_task;

static size_t default_dv_priority = 0;

static char *my_short_id;

/**
 * Transmit handle to the plugin.
 */
static struct GNUNET_SERVER_TransmitHandle *plugin_transmit_handle;

/**
 * Head of DLL for client messages
 */
static struct PendingMessage *plugin_pending_head;

/**
 * Tail of DLL for client messages
 */
static struct PendingMessage *plugin_pending_tail;

/**
 * Handle to the peerinfo service
 */
static struct GNUNET_PEERINFO_Handle *peerinfo_handle;

/**
 * Transmit handle to core service.
 */
static struct GNUNET_CORE_TransmitHandle *core_transmit_handle;

/**
 * Head of DLL for core messages
 */
static struct PendingMessage *core_pending_head;

/**
 * Tail of DLL for core messages
 */
static struct PendingMessage *core_pending_tail;

/**
 * Map of PeerIdentifiers to 'struct GNUNET_dv_neighbor*'s for all
 * directly connected peers.
 */
static struct GNUNET_CONTAINER_MultiHashMap *direct_neighbors;

/**
 * Map of PeerIdentifiers to 'struct GNUNET_dv_neighbor*'s for
 * peers connected via DV (extended neighborhood).  Does ALSO
 * include any peers that are in 'direct_neighbors'; for those
 * peers, the cost will be zero and the referrer all zeros.
 */
static struct GNUNET_CONTAINER_MultiHashMap *extended_neighbors;

/**
 * We use the min heap (min refers to cost) to prefer
 * gossipping about peers with small costs.
 */
static struct GNUNET_CONTAINER_Heap *neighbor_min_heap;

/**
 * We use the max heap (max refers to cost) for general
 * iterations over all peers and to remove the most costly
 * connection if we have too many.
 */
static struct GNUNET_CONTAINER_Heap *neighbor_max_heap;

/**
 * Handle for the statistics service.
 */
struct GNUNET_STATISTICS_Handle *stats;

/**
 * How far out to keep peers we learn about.
 */
static unsigned long long fisheye_depth;

/**
 * How many peers to store at most.
 */
static unsigned long long max_table_size;

/**
 * We've been given a target ID based on the random numbers that
 * we assigned to our DV-neighborhood.  Find the entry for the
 * respective neighbor.
 */
static int
find_destination (void *cls, struct GNUNET_CONTAINER_HeapNode *node,
                  void *element, GNUNET_CONTAINER_HeapCostType cost)
{
  struct FindDestinationContext *fdc = cls;
  struct DistantNeighbor *dn = element;

  if (fdc->tid != dn->our_id)
    return GNUNET_YES;
  fdc->dest = dn;
  return GNUNET_NO;
}


/**
 * We've been given a target ID based on the random numbers that
 * we assigned to our DV-neighborhood.  Find the entry for the
 * respective neighbor.
 */
static int
find_specific_id (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct FindIDContext *fdc = cls;
  struct DistantNeighbor *dn = value;

  if (memcmp
      (&dn->referrer->identity, fdc->via,
       sizeof (struct GNUNET_PeerIdentity)) == 0)
  {
    fdc->tid = dn->referrer_id;
    return GNUNET_NO;
  }
  return GNUNET_YES;
}

/**
 * Find a distant peer whose referrer_id matches what we're
 * looking for.  For looking up a peer we've gossipped about
 * but is now disconnected.  Need to do this because we don't
 * want to remove those that may be accessible via a different
 * route.
 */
static int
find_distant_peer (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct FindDestinationContext *fdc = cls;
  struct DistantNeighbor *distant = value;

  if (fdc->tid == distant->referrer_id)
  {
    fdc->dest = distant;
    return GNUNET_NO;
  }
  return GNUNET_YES;
}

/**
 * Function called to notify a client about the socket
 * begin ready to queue more data.  "buf" will be
 * NULL and "size" zero if the socket was closed for
 * writing in the meantime.
 *
 * @param cls closure
 * @param size number of bytes available in buf
 * @param buf where the callee should write the message
 * @return number of bytes written to buf
 */
size_t
transmit_to_plugin (void *cls, size_t size, void *buf)
{
  char *cbuf = buf;
  struct PendingMessage *reply;
  size_t off;
  size_t msize;

  if (buf == NULL)
  {
    /* client disconnected */
#if DEBUG_DV_MESSAGES
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: %s buffer was NULL (client disconnect?)\n", my_short_id,
                "transmit_to_plugin");
#endif
    return 0;
  }
  plugin_transmit_handle = NULL;
  off = 0;
  while ((NULL != (reply = plugin_pending_head)) &&
         (size >= off + (msize = ntohs (reply->msg->size))))
  {
    GNUNET_CONTAINER_DLL_remove (plugin_pending_head, plugin_pending_tail,
                                 reply);
    memcpy (&cbuf[off], reply->msg, msize);
    GNUNET_free (reply);
    off += msize;
  }

  if (plugin_pending_head != NULL)
    plugin_transmit_handle =
        GNUNET_SERVER_notify_transmit_ready (client_handle,
                                             ntohs (plugin_pending_head->msg->
                                                    size),
                                             GNUNET_TIME_UNIT_FOREVER_REL,
                                             &transmit_to_plugin, NULL);

  return off;
}

/**
 * Send a message to the dv plugin.
 *
 * @param sender the direct sender of the message
 * @param message the message to send to the plugin
 *        (may be an encapsulated type)
 * @param message_size the size of the message to be sent
 * @param distant_neighbor the original sender of the message
 * @param cost the cost to the original sender of the message
 */
void
send_to_plugin (const struct GNUNET_PeerIdentity *sender,
                const struct GNUNET_MessageHeader *message, size_t message_size,
                struct GNUNET_PeerIdentity *distant_neighbor, size_t cost)
{
  struct GNUNET_DV_MessageReceived *received_msg;
  struct PendingMessage *pending_message;
  char *sender_address;
  size_t sender_address_len;
  char *packed_msg_start;
  int size;

#if DEBUG_DV
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "send_to_plugin called with peer %s as sender\n",
              GNUNET_i2s (distant_neighbor));
#endif

  if (memcmp (sender, distant_neighbor, sizeof (struct GNUNET_PeerIdentity)) !=
      0)
  {
    sender_address_len = sizeof (struct GNUNET_PeerIdentity) * 2;
    sender_address = GNUNET_malloc (sender_address_len);
    memcpy (sender_address, distant_neighbor,
            sizeof (struct GNUNET_PeerIdentity));
    memcpy (&sender_address[sizeof (struct GNUNET_PeerIdentity)], sender,
            sizeof (struct GNUNET_PeerIdentity));
  }
  else
  {
    sender_address_len = sizeof (struct GNUNET_PeerIdentity);
    sender_address = GNUNET_malloc (sender_address_len);
    memcpy (sender_address, sender, sizeof (struct GNUNET_PeerIdentity));
  }

  size =
      sizeof (struct GNUNET_DV_MessageReceived) + sender_address_len +
      message_size;
  received_msg = GNUNET_malloc (size);
  received_msg->header.size = htons (size);
  received_msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_DV_RECEIVE);
  received_msg->distance = htonl (cost);
  received_msg->msg_len = htonl (message_size);
  /* Set the sender in this message to be the original sender! */
  memcpy (&received_msg->sender, distant_neighbor,
          sizeof (struct GNUNET_PeerIdentity));
  /* Copy the intermediate sender to the end of the message, this is how the transport identifies this peer */
  memcpy (&received_msg[1], sender_address, sender_address_len);
  GNUNET_free (sender_address);
  /* Copy the actual message after the sender */
  packed_msg_start = (char *) &received_msg[1];
  packed_msg_start = &packed_msg_start[sender_address_len];
  memcpy (packed_msg_start, message, message_size);
  pending_message = GNUNET_malloc (sizeof (struct PendingMessage) + size);
  pending_message->msg = (struct GNUNET_MessageHeader *) &pending_message[1];
  memcpy (&pending_message[1], received_msg, size);
  GNUNET_free (received_msg);

  GNUNET_CONTAINER_DLL_insert_after (plugin_pending_head, plugin_pending_tail,
                                     plugin_pending_tail, pending_message);

  if (client_handle != NULL)
  {
    if (plugin_transmit_handle == NULL)
    {
      plugin_transmit_handle =
          GNUNET_SERVER_notify_transmit_ready (client_handle, size,
                                               GNUNET_TIME_UNIT_FOREVER_REL,
                                               &transmit_to_plugin, NULL);
    }
  }
  else
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Failed to queue message for plugin, client_handle not yet set (how?)!\n");
  }
}

/* Declare here so retry_core_send is aware of it */
size_t
core_transmit_notify (void *cls, size_t size, void *buf);

/**
 *  Try to send another message from our core sending list
 */
static void
try_core_send (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct PendingMessage *pending;

  pending = core_pending_head;

  if (core_transmit_handle != NULL)
    return;                     /* Message send already in progress */

  if ((pending != NULL) && (coreAPI != NULL))
    core_transmit_handle =
        GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
                                           pending->importance,
                                           pending->timeout,
                                           &pending->recipient,
                                           pending->msg_size,
                                           &core_transmit_notify, NULL);
}


/**
 * Function called to notify a client about the socket
 * being ready to queue more data.  "buf" will be
 * NULL and "size" zero if the socket was closed for
 * writing in the meantime.
 *
 * @param cls closure (NULL)
 * @param size number of bytes available in buf
 * @param buf where the callee should write the message
 * @return number of bytes written to buf
 */
size_t
core_transmit_notify (void *cls, size_t size, void *buf)
{
  char *cbuf = buf;
  struct PendingMessage *pending;
  struct PendingMessage *client_reply;
  size_t off;
  size_t msize;

  if (buf == NULL)
  {
    /* client disconnected */
#if DEBUG_DV
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s': buffer was NULL\n", "DHT");
#endif
    return 0;
  }

  core_transmit_handle = NULL;
  off = 0;
  pending = core_pending_head;
  if ((pending != NULL) && (size >= (msize = ntohs (pending->msg->size))))
  {
#if DEBUG_DV
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "`%s' : transmit_notify (core) called with size %d\n",
                "dv service", msize);
#endif
    GNUNET_CONTAINER_DLL_remove (core_pending_head, core_pending_tail, pending);
    if (pending->send_result != NULL)   /* Will only be non-null if a real client asked for this send */
    {
      client_reply =
          GNUNET_malloc (sizeof (struct PendingMessage) +
                         sizeof (struct GNUNET_DV_SendResultMessage));
      client_reply->msg = (struct GNUNET_MessageHeader *) &client_reply[1];
      memcpy (&client_reply[1], pending->send_result,
              sizeof (struct GNUNET_DV_SendResultMessage));
      GNUNET_free (pending->send_result);

      GNUNET_CONTAINER_DLL_insert_after (plugin_pending_head,
                                         plugin_pending_tail,
                                         plugin_pending_tail, client_reply);
      if (client_handle != NULL)
      {
        if (plugin_transmit_handle == NULL)
        {
          plugin_transmit_handle =
              GNUNET_SERVER_notify_transmit_ready (client_handle,
                                                   sizeof (struct
                                                           GNUNET_DV_SendResultMessage),
                                                   GNUNET_TIME_UNIT_FOREVER_REL,
                                                   &transmit_to_plugin, NULL);
        }
        else
        {
          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                      "Failed to queue message for plugin, must be one in progress already!!\n");
        }
      }
    }
    memcpy (&cbuf[off], pending->msg, msize);
    GNUNET_free (pending);
    off += msize;
  }
  /*reply = core_pending_head; */

  GNUNET_SCHEDULER_add_now (&try_core_send, NULL);
  /*if (reply != NULL)
   * core_transmit_handle = GNUNET_CORE_notify_transmit_ready(coreAPI, GNUNET_YES,  reply->importance, reply->timeout, &reply->recipient, reply->msg_size, &core_transmit_notify, NULL); */

  return off;
}


/**
 * Send a DV data message via DV.
 *
 * @param sender the original sender of the message
 * @param recipient the next hop recipient, may be our direct peer, maybe not
 * @param send_context the send context
 */
static int
send_message_via (const struct GNUNET_PeerIdentity *sender,
                  const struct GNUNET_PeerIdentity *recipient,
                  struct DV_SendContext *send_context)
{
  p2p_dv_MESSAGE_Data *toSend;
  unsigned int msg_size;
  unsigned int recipient_id;
  unsigned int sender_id;
  struct DistantNeighbor *source;
  struct PendingMessage *pending_message;
  struct FindIDContext find_context;

#if DEBUG_DV
  char shortname[5];
#endif

  msg_size = send_context->message_size + sizeof (p2p_dv_MESSAGE_Data);

  find_context.dest = send_context->distant_peer;
  find_context.via = recipient;
  find_context.tid = 0;
  GNUNET_CONTAINER_multihashmap_get_multiple (extended_neighbors,
                                              &send_context->
                                              distant_peer->hashPubKey,
                                              &find_specific_id, &find_context);

  if (find_context.tid == 0)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "%s: find_specific_id failed to find peer!\n", my_short_id);
    /* target unknown to us, drop! */
    return GNUNET_SYSERR;
  }
  recipient_id = find_context.tid;

  if (0 == (memcmp (&my_identity, sender, sizeof (struct GNUNET_PeerIdentity))))
  {
    sender_id = 0;
    source =
        GNUNET_CONTAINER_multihashmap_get (extended_neighbors,
                                           &sender->hashPubKey);
    if (source != NULL)
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                  "%s: send_message_via found %s, myself in extended peer list???\n",
                  my_short_id, GNUNET_i2s (&source->identity));
  }
  else
  {
    source =
        GNUNET_CONTAINER_multihashmap_get (extended_neighbors,
                                           &sender->hashPubKey);
    if (source == NULL)
    {
      /* sender unknown to us, drop! */
      return GNUNET_SYSERR;
    }
    sender_id = source->our_id;
  }

  pending_message = GNUNET_malloc (sizeof (struct PendingMessage) + msg_size);
  pending_message->msg = (struct GNUNET_MessageHeader *) &pending_message[1];
  pending_message->send_result = send_context->send_result;
  memcpy (&pending_message->recipient, recipient,
          sizeof (struct GNUNET_PeerIdentity));
  pending_message->msg_size = msg_size;
  pending_message->importance = send_context->importance;
  pending_message->timeout = send_context->timeout;
  toSend = (p2p_dv_MESSAGE_Data *) pending_message->msg;
  toSend->header.size = htons (msg_size);
  toSend->header.type = htons (GNUNET_MESSAGE_TYPE_DV_DATA);
  toSend->sender = htonl (sender_id);
  toSend->recipient = htonl (recipient_id);
#if DEBUG_DV_MESSAGES
  toSend->uid = send_context->uid;      /* Still sent around in network byte order */
#else
  toSend->uid = htonl (0);
#endif

  memcpy (&toSend[1], send_context->message, send_context->message_size);

#if DEBUG_DV
  memcpy (&shortname, GNUNET_i2s (send_context->distant_peer), 4);
  shortname[4] = '\0';
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Notifying core of send to destination `%s' via `%s' size %u\n",
              "DV", &shortname, GNUNET_i2s (recipient), msg_size);
#endif

  GNUNET_CONTAINER_DLL_insert_after (core_pending_head, core_pending_tail,
                                     core_pending_tail, pending_message);

  GNUNET_SCHEDULER_add_now (try_core_send, NULL);

  return GNUNET_YES;
}

/**
 * Given a FindLeastCostContext, and a set
 * of peers that match the target, return the cheapest.
 *
 * @param cls closure, a struct FindLeastCostContext
 * @param key the key identifying the target peer
 * @param value the target peer
 *
 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
 */
static int
find_least_cost_peer (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct FindLeastCostContext *find_context = cls;
  struct DistantNeighbor *dn = value;

  if (dn->cost < find_context->least_cost)
  {
    find_context->target = dn;
  }
  if (dn->cost == DIRECT_NEIGHBOR_COST)
    return GNUNET_NO;
  return GNUNET_YES;
}

/**
 * Send a DV data message via DV.
 *
 * @param recipient the ultimate recipient of this message
 * @param sender the original sender of the message
 * @param specific_neighbor the specific neighbor to send this message via
 * @param message the packed message
 * @param message_size size of the message
 * @param importance what priority to send this message with
 * @param uid the unique identifier of this message (or 0 for none)
 * @param timeout how long to possibly delay sending this message
 */
static int
send_message (const struct GNUNET_PeerIdentity *recipient,
              const struct GNUNET_PeerIdentity *sender,
              const struct DistantNeighbor *specific_neighbor,
              const struct GNUNET_MessageHeader *message, size_t message_size,
              unsigned int importance, unsigned int uid,
              struct GNUNET_TIME_Relative timeout)
{
  p2p_dv_MESSAGE_Data *toSend;
  unsigned int msg_size;
  unsigned int cost;
  unsigned int recipient_id;
  unsigned int sender_id;
  struct DistantNeighbor *target;
  struct DistantNeighbor *source;
  struct PendingMessage *pending_message;
  struct FindLeastCostContext find_least_ctx;

#if DEBUG_DV_PEER_NUMBERS
  struct GNUNET_CRYPTO_HashAsciiEncoded encPeerFrom;
  struct GNUNET_CRYPTO_HashAsciiEncoded encPeerTo;
  struct GNUNET_CRYPTO_HashAsciiEncoded encPeerVia;
#endif
  msg_size = message_size + sizeof (p2p_dv_MESSAGE_Data);

  find_least_ctx.least_cost = -1;
  find_least_ctx.target = NULL;
  /*
   * Need to find the least cost peer, lest the transport selection keep
   * picking the same DV route for the same destination which results
   * in messages looping forever.  Relatively cheap, we don't iterate
   * over all known peers, just those that apply.
   */
  GNUNET_CONTAINER_multihashmap_get_multiple (extended_neighbors,
                                              &recipient->hashPubKey,
                                              &find_least_cost_peer,
                                              &find_least_ctx);
  target = find_least_ctx.target;

  if (target == NULL)
  {
    /* target unknown to us, drop! */
    return GNUNET_SYSERR;
  }
  recipient_id = target->referrer_id;

  source =
      GNUNET_CONTAINER_multihashmap_get (extended_neighbors,
                                         &sender->hashPubKey);
  if (source == NULL)
  {
    if (0 !=
        (memcmp (&my_identity, sender, sizeof (struct GNUNET_PeerIdentity))))
    {
      /* sender unknown to us, drop! */
      return GNUNET_SYSERR;
    }
    sender_id = 0;              /* 0 == us */
  }
  else
  {
    /* find out the number that we use when we gossip about
     * the sender */
    sender_id = source->our_id;
  }

#if DEBUG_DV_PEER_NUMBERS
  GNUNET_CRYPTO_hash_to_enc (&source->identity.hashPubKey, &encPeerFrom);
  GNUNET_CRYPTO_hash_to_enc (&target->referrer->identity.hashPubKey,
                             &encPeerVia);
  encPeerFrom.encoding[4] = '\0';
  encPeerVia.encoding[4] = '\0';
#endif
  if ((sender_id != 0) &&
      (0 ==
       memcmp (&source->identity, &target->referrer->identity,
               sizeof (struct GNUNET_PeerIdentity))))
  {
    return 0;
  }

  cost = target->cost;
  pending_message = GNUNET_malloc (sizeof (struct PendingMessage) + msg_size);
  pending_message->msg = (struct GNUNET_MessageHeader *) &pending_message[1];
  pending_message->send_result = NULL;
  pending_message->importance = importance;
  pending_message->timeout = timeout;
  memcpy (&pending_message->recipient, &target->referrer->identity,
          sizeof (struct GNUNET_PeerIdentity));
  pending_message->msg_size = msg_size;
  toSend = (p2p_dv_MESSAGE_Data *) pending_message->msg;
  toSend->header.size = htons (msg_size);
  toSend->header.type = htons (GNUNET_MESSAGE_TYPE_DV_DATA);
  toSend->sender = htonl (sender_id);
  toSend->recipient = htonl (recipient_id);
#if DEBUG_DV_MESSAGES
  toSend->uid = htonl (uid);
#else
  toSend->uid = htonl (0);
#endif

#if DEBUG_DV_PEER_NUMBERS
  GNUNET_CRYPTO_hash_to_enc (&target->identity.hashPubKey, &encPeerTo);
  encPeerTo.encoding[4] = '\0';
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Sending DATA message. Sender id %u, source %s, destination %s, via %s\n",
              GNUNET_i2s (&my_identity), sender_id, &encPeerFrom, &encPeerTo,
              &encPeerVia);
#endif
  memcpy (&toSend[1], message, message_size);
  if ((source != NULL) && (source->pkey == NULL))       /* Test our hypothesis about message failures! */
  {
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "%s: Sending message, but anticipate recipient will not know sender!!!\n\n\n",
                my_short_id);
  }
  GNUNET_CONTAINER_DLL_insert_after (core_pending_head, core_pending_tail,
                                     core_pending_tail, pending_message);
#if DEBUG_DV
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Notifying core of send size %d to destination `%s'\n",
              "DV SEND MESSAGE", msg_size, GNUNET_i2s (recipient));
#endif

  GNUNET_SCHEDULER_add_now (try_core_send, NULL);
  return (int) cost;
}

#if USE_PEER_ID
struct CheckPeerContext
{
  /**
   * Peer we found
   */
  struct DistantNeighbor *peer;

  /**
   * Sender id to search for
   */
  unsigned int sender_id;
};

/**
 * Iterator over hash map entries.
 *
 * @param cls closure
 * @param key current key code
 * @param value value in the hash map
 * @return GNUNET_YES if we should continue to
 *         iterate,
 *         GNUNET_NO if not.
 */
int
checkPeerID (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct CheckPeerContext *ctx = cls;
  struct DistantNeighbor *distant = value;

  if (memcmp (key, &ctx->sender_id, sizeof (unsigned int)) == 0)
  {
    ctx->peer = distant;
    return GNUNET_NO;
  }
  return GNUNET_YES;

}
#endif


/**
 * Handler for messages parsed out by the tokenizer from
 * DV DATA received for this peer.
 *
 * @param cls NULL
 * @param client the TokenizedMessageContext which contains message information
 * @param message the actual message
 */
int
tokenized_message_handler (void *cls, void *client,
                           const struct GNUNET_MessageHeader *message)
{
  struct TokenizedMessageContext *ctx = client;

  GNUNET_break_op (ntohs (message->type) != GNUNET_MESSAGE_TYPE_DV_GOSSIP);
  GNUNET_break_op (ntohs (message->type) != GNUNET_MESSAGE_TYPE_DV_DATA);
  if ((ntohs (message->type) != GNUNET_MESSAGE_TYPE_DV_GOSSIP) &&
      (ntohs (message->type) != GNUNET_MESSAGE_TYPE_DV_DATA))
  {
#if DEBUG_DV_MESSAGES
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: Receives %s message for me, uid %u, size %d, type %d cost %u from %s!\n",
                my_short_id, "DV DATA", ctx->uid, ntohs (message->size),
                ntohs (message->type), ctx->distant->cost,
                GNUNET_i2s (&ctx->distant->identity));
#endif
    GNUNET_assert (memcmp
                   (ctx->peer, &ctx->distant->identity,
                    sizeof (struct GNUNET_PeerIdentity)) != 0);
    send_to_plugin (ctx->peer, message, ntohs (message->size),
                    &ctx->distant->identity, ctx->distant->cost);
  }
  return GNUNET_OK;
}

#if DELAY_FORWARDS
struct DelayedMessageContext
{
  struct GNUNET_PeerIdentity dest;
  struct GNUNET_PeerIdentity sender;
  struct GNUNET_MessageHeader *message;
  size_t message_size;
  uint32_t uid;
};

void
send_message_delayed (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct DelayedMessageContext *msg_ctx = cls;

  if (msg_ctx != NULL)
  {
    send_message (&msg_ctx->dest, &msg_ctx->sender, NULL, msg_ctx->message,
                  msg_ctx->message_size, default_dv_priority, msg_ctx->uid,
                  GNUNET_TIME_UNIT_FOREVER_REL);
    GNUNET_free (msg_ctx->message);
    GNUNET_free (msg_ctx);
  }
}
#endif

/**
 * Get distance information from 'atsi'.
 *
 * @param atsi performance data
 * @param atsi_count number of entries in atsi
 * @return connected transport distance
 */
static uint32_t
get_atsi_distance (const struct GNUNET_ATS_Information *atsi,
                   unsigned int atsi_count)
{
  unsigned int i;

  for (i = 0; i < atsi_count; i++)
    if (ntohl (atsi[i].type) == GNUNET_ATS_QUALITY_NET_DISTANCE)
      return ntohl (atsi->value);
  /* FIXME: we do not have distance data? Assume direct neighbor. */
  return DIRECT_NEIGHBOR_COST;
}

/**
 * Find latency information in 'atsi'.
 *
 * @param atsi performance data
 * @param atsi_count number of entries in atsi
 * @return connection latency
 */
static struct GNUNET_TIME_Relative
get_atsi_latency (const struct GNUNET_ATS_Information *atsi,
                  unsigned int atsi_count)
{
  unsigned int i;

  for (i = 0; i < atsi_count; i++)
    if (ntohl (atsi[i].type) == GNUNET_ATS_QUALITY_NET_DELAY)
      return GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
                                            ntohl (atsi->value));
  GNUNET_break (0);
  /* how can we not have latency data? */
  return GNUNET_TIME_UNIT_SECONDS;
}

/**
 * Core handler for dv data messages.  Whatever this message
 * contains all we really have to do is rip it out of its
 * DV layering and give it to our pal the DV plugin to report
 * in with.
 *
 * @param cls closure
 * @param peer peer which sent the message (immediate sender)
 * @param message the message
 * @param atsi transport ATS information (latency, distance, etc.)
 * @param atsi_count number of entries in atsi
 */
static int
handle_dv_data_message (void *cls, const struct GNUNET_PeerIdentity *peer,
                        const struct GNUNET_MessageHeader *message,
                        const struct GNUNET_ATS_Information *atsi,
                        unsigned int atsi_count)
{
  const p2p_dv_MESSAGE_Data *incoming = (const p2p_dv_MESSAGE_Data *) message;
  const struct GNUNET_MessageHeader *packed_message;
  struct DirectNeighbor *dn;
  struct DistantNeighbor *pos;
  unsigned int sid;             /* Sender id */
  unsigned int tid;             /* Target id */
  struct GNUNET_PeerIdentity *original_sender;
  struct GNUNET_PeerIdentity *destination;
  struct FindDestinationContext fdc;
  struct TokenizedMessageContext tkm_ctx;
  int i;
  int found_pos;

#if DELAY_FORWARDS
  struct DelayedMessageContext *delayed_context;
#endif
#if USE_PEER_ID
  struct CheckPeerContext checkPeerCtx;
#endif
#if DEBUG_DV_MESSAGES
  char *sender_id;
#endif
  int ret;
  size_t packed_message_size;
  char *cbuf;
  uint32_t distance;            /* Distance information */
  struct GNUNET_TIME_Relative latency;  /* Latency information */

  packed_message_size =
      ntohs (incoming->header.size) - sizeof (p2p_dv_MESSAGE_Data);
#if DEBUG_DV
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Receives DATA message from %s size %d, packed size %d!\n",
              my_short_id, GNUNET_i2s (peer), ntohs (incoming->header.size),
              packed_message_size);
#endif

  if (ntohs (incoming->header.size) <
      sizeof (p2p_dv_MESSAGE_Data) + sizeof (struct GNUNET_MessageHeader))
  {
#if DEBUG_DV
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "`%s': Message sizes don't add up, total size %u, expected at least %u!\n",
                "dv service", ntohs (incoming->header.size),
                sizeof (p2p_dv_MESSAGE_Data) +
                sizeof (struct GNUNET_MessageHeader));
#endif
    return GNUNET_SYSERR;
  }

  /* Iterate over ATS_Information to get distance and latency */
  latency = get_atsi_latency (atsi, atsi_count);
  distance = get_atsi_distance (atsi, atsi_count);
  dn = GNUNET_CONTAINER_multihashmap_get (direct_neighbors, &peer->hashPubKey);
  if (dn == NULL)
    return GNUNET_OK;

  sid = ntohl (incoming->sender);
#if USE_PEER_ID
  if (sid != 0)
  {
    checkPeerCtx.sender_id = sid;
    checkPeerCtx.peer = NULL;
    GNUNET_CONTAINER_multihashmap_iterate (extended_neighbors, &checkPeerID,
                                           &checkPeerCtx);
    pos = checkPeerCtx.peer;
  }
  else
  {
    pos =
        GNUNET_CONTAINER_multihashmap_get (extended_neighbors,
                                           &peer->hashPubKey);
  }
#else
  pos = dn->referee_head;
  while ((NULL != pos) && (pos->referrer_id != sid))
    pos = pos->next;
#endif

  if (pos == NULL)
  {
#if DEBUG_DV_MESSAGES
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: unknown sender (%u), Message uid %u from %s!\n",
                my_short_id, ntohl (incoming->sender), ntohl (incoming->uid),
                GNUNET_i2s (&dn->identity));
    pos = dn->referee_head;
    while ((NULL != pos) && (pos->referrer_id != sid))
    {
      sender_id = GNUNET_strdup (GNUNET_i2s (&pos->identity));
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "I know sender %u %s\n",
                  pos->referrer_id, sender_id);
      GNUNET_free (sender_id);
      pos = pos->next;
    }
#endif

    found_pos = -1;
    for (i = 0; i < MAX_OUTSTANDING_MESSAGES; i++)
    {
      if (dn->pending_messages[i].sender_id == 0)
      {
        found_pos = i;
        break;
      }
    }

    if (found_pos == -1)
    {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                  "%s: Too many unknown senders (%u), ignoring message! Message uid %llu from %s!\n",
                  my_short_id, ntohl (incoming->sender), ntohl (incoming->uid),
                  GNUNET_i2s (&dn->identity));
    }
    else
    {
      dn->pending_messages[found_pos].message =
          GNUNET_malloc (ntohs (message->size));
      memcpy (dn->pending_messages[found_pos].message, message,
              ntohs (message->size));
      dn->pending_messages[found_pos].distance = distance;
      dn->pending_messages[found_pos].latency = latency;
      memcpy (&dn->pending_messages[found_pos].sender, peer,
              sizeof (struct GNUNET_PeerIdentity));
      dn->pending_messages[found_pos].sender_id = sid;
    }
    /* unknown sender */
    return GNUNET_OK;
  }
  original_sender = &pos->identity;
  tid = ntohl (incoming->recipient);
  if (tid == 0)
  {
    /* 0 == us */
    cbuf = (char *) &incoming[1];

    tkm_ctx.peer = peer;
    tkm_ctx.distant = pos;
    tkm_ctx.uid = ntohl (incoming->uid);
    if (GNUNET_OK !=
        GNUNET_SERVER_mst_receive (coreMST, &tkm_ctx, cbuf, packed_message_size,
                                   GNUNET_NO, GNUNET_NO))
    {
      GNUNET_break_op (0);
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                  "%s: %s Received corrupt data, discarding!", my_short_id,
                  "DV SERVICE");
    }
    return GNUNET_OK;
  }
  else
  {
    packed_message = (struct GNUNET_MessageHeader *) &incoming[1];
  }

  /* FIXME: this is the *only* per-request operation we have in DV
   * that is O(n) in relation to the number of connected peers; a
   * hash-table lookup could easily solve this (minor performance
   * issue) */
  fdc.tid = tid;
  fdc.dest = NULL;
  GNUNET_CONTAINER_heap_iterate (neighbor_max_heap, &find_destination, &fdc);

#if DEBUG_DV
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Receives %s message for someone else!\n", "dv", "DV DATA");
#endif

  if (fdc.dest == NULL)
  {
#if DEBUG_DV_MESSAGES
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: Receives %s message uid %u for someone we don't know (id %u)!\n",
                my_short_id, "DV DATA", ntohl (incoming->uid), tid);
#endif
    return GNUNET_OK;
  }
  destination = &fdc.dest->identity;

  if (0 == memcmp (destination, peer, sizeof (struct GNUNET_PeerIdentity)))
  {
    /* FIXME: create stat: routing loop-discard! */

#if DEBUG_DV_MESSAGES
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: DROPPING MESSAGE uid %u type %d, routing loop! Message immediately from %s!\n",
                my_short_id, ntohl (incoming->uid),
                ntohs (packed_message->type), GNUNET_i2s (&dn->identity));
#endif
    return GNUNET_OK;
  }

  /* At this point we have a message, and we need to forward it on to the
   * next DV hop.
   */
#if DEBUG_DV_MESSAGES
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: FORWARD %s message for %s, uid %u, size %d type %d, cost %u!\n",
              my_short_id, "DV DATA", GNUNET_i2s (destination),
              ntohl (incoming->uid), ntohs (packed_message->size),
              ntohs (packed_message->type), pos->cost);
#endif

#if DELAY_FORWARDS
  if (GNUNET_TIME_absolute_get_duration (pos->last_gossip).abs_value <
      GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 2).abs_value)
  {
    delayed_context = GNUNET_malloc (sizeof (struct DelayedMessageContext));
    memcpy (&delayed_context->dest, destination,
            sizeof (struct GNUNET_PeerIdentity));
    memcpy (&delayed_context->sender, original_sender,
            sizeof (struct GNUNET_PeerIdentity));
    delayed_context->message = GNUNET_malloc (packed_message_size);
    memcpy (delayed_context->message, packed_message, packed_message_size);
    delayed_context->message_size = packed_message_size;
    delayed_context->uid = ntohl (incoming->uid);
    GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply
                                  (GNUNET_TIME_UNIT_MILLISECONDS, 2500),
                                  &send_message_delayed, delayed_context);
    return GNUNET_OK;
  }
  else
#endif
  {
    ret =
        send_message (destination, original_sender, NULL, packed_message,
                      packed_message_size, default_dv_priority,
                      ntohl (incoming->uid),
                      GNUNET_TIME_UNIT_FOREVER_REL);
  }
  if (ret != GNUNET_SYSERR)
    return GNUNET_OK;
  else
  {
#if DEBUG_MESSAGE_DROP
    char *direct_id = GNUNET_strdup (GNUNET_i2s (&dn->identity));

    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: DROPPING MESSAGE type %d, forwarding failed! Message immediately from %s!\n",
                GNUNET_i2s (&my_identity),
                ntohs (((struct GNUNET_MessageHeader *) &incoming[1])->type),
                direct_id);
    GNUNET_free (direct_id);
#endif
    return GNUNET_SYSERR;
  }
}

#if DEBUG_DV
/**
 * Iterator over hash map entries.
 *
 * @param cls closure (NULL)
 * @param key current key code
 * @param value value in the hash map (DistantNeighbor)
 * @return GNUNET_YES if we should continue to
 *         iterate,
 *         GNUNET_NO if not.
 */
int
print_neighbors (void *cls, const struct GNUNET_HashCode * key, void *abs_value)
{
  struct DistantNeighbor *distant_neighbor = abs_value;
  char my_shortname[5];
  char referrer_shortname[5];

  memcpy (&my_shortname, GNUNET_i2s (&my_identity), 4);
  my_shortname[4] = '\0';
  memcpy (&referrer_shortname,
          GNUNET_i2s (&distant_neighbor->referrer->identity), 4);
  referrer_shortname[4] = '\0';

  GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
              "`%s' %s: Peer `%s', distance %d, referrer `%s' pkey: %s\n",
              &my_shortname, "DV", GNUNET_i2s (&distant_neighbor->identity),
              distant_neighbor->cost, &referrer_shortname,
              distant_neighbor->pkey == NULL ? "no" : "yes");
  return GNUNET_YES;
}
#endif

/**
 *  Scheduled task which gossips about known direct peers to other connected
 *  peers.  Will run until called with reason shutdown.
 */
static void
neighbor_send_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct NeighborSendContext *send_context = cls;

#if DEBUG_DV_GOSSIP_SEND
  char *encPeerAbout;
  char *encPeerTo;
#endif
  struct DistantNeighbor *about;
  struct DirectNeighbor *to;
  struct FastGossipNeighborList *about_list;

  p2p_dv_MESSAGE_NeighborInfo *message;
  struct PendingMessage *pending_message;

  if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
  {
#if DEBUG_DV_GOSSIP
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: Called with reason shutdown, shutting down!\n",
                GNUNET_i2s (&my_identity));
#endif
    return;
  }

  if (send_context->fast_gossip_list_head != NULL)
  {
    about_list = send_context->fast_gossip_list_head;
    about = about_list->about;
    GNUNET_CONTAINER_DLL_remove (send_context->fast_gossip_list_head,
                                 send_context->fast_gossip_list_tail,
                                 about_list);
    GNUNET_free (about_list);
  }
  else
  {
    /* FIXME: this may become a problem, because the heap walk has only one internal "walker".  This means
     * that if two neighbor_send_tasks are operating in lockstep (which is quite possible, given default
     * values for all connected peers) there may be a serious bias as to which peers get gossiped about!
     * Probably the *best* way to fix would be to have an opaque pointer to the walk position passed as
     * part of the walk_get_next call.  Then the heap would have to keep a list of walks, or reset the walk
     * whenever a modification has been detected.  Yuck either way.  Perhaps we could iterate over the heap
     * once to get a list of peers to gossip about and gossip them over time... But then if one goes away
     * in the mean time that becomes nasty.  For now we'll just assume that the walking is done
     * asynchronously enough to avoid major problems (-;
     *
     * NOTE: probably fixed once we decided send rate based on allowed bandwidth.
     */
    about = GNUNET_CONTAINER_heap_walk_get_next (neighbor_min_heap);
  }
  to = send_context->toNeighbor;

  if ((about != NULL) && (to != about->referrer /* split horizon */ ) &&
#if SUPPORT_HIDING
      (about->hidden == GNUNET_NO) &&
#endif
      (to != NULL) &&
      (0 !=
       memcmp (&about->identity, &to->identity,
               sizeof (struct GNUNET_PeerIdentity))) && (about->pkey != NULL))
  {
#if DEBUG_DV_GOSSIP_SEND
    encPeerAbout = GNUNET_strdup (GNUNET_i2s (&about->identity));
    encPeerTo = GNUNET_strdup (GNUNET_i2s (&to->identity));
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: Sending info about peer %s id %u to directly connected peer %s\n",
                GNUNET_i2s (&my_identity), encPeerAbout, about->our_id,
                encPeerTo);
    GNUNET_free (encPeerAbout);
    GNUNET_free (encPeerTo);
#endif
    about->last_gossip = GNUNET_TIME_absolute_get ();
    pending_message =
        GNUNET_malloc (sizeof (struct PendingMessage) +
                       sizeof (p2p_dv_MESSAGE_NeighborInfo));
    pending_message->msg = (struct GNUNET_MessageHeader *) &pending_message[1];
    pending_message->importance = default_dv_priority;
    pending_message->timeout = GNUNET_TIME_UNIT_FOREVER_REL;
    memcpy (&pending_message->recipient, &to->identity,
            sizeof (struct GNUNET_PeerIdentity));
    pending_message->msg_size = sizeof (p2p_dv_MESSAGE_NeighborInfo);
    message = (p2p_dv_MESSAGE_NeighborInfo *) pending_message->msg;
    message->header.size = htons (sizeof (p2p_dv_MESSAGE_NeighborInfo));
    message->header.type = htons (GNUNET_MESSAGE_TYPE_DV_GOSSIP);
    message->cost = htonl (about->cost);
    message->neighbor_id = htonl (about->our_id);

    memcpy (&message->pkey, about->pkey,
            sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
    memcpy (&message->neighbor, &about->identity,
            sizeof (struct GNUNET_PeerIdentity));

    GNUNET_CONTAINER_DLL_insert_after (core_pending_head, core_pending_tail,
                                       core_pending_tail, pending_message);

    GNUNET_SCHEDULER_add_now (try_core_send, NULL);
    /*if (core_transmit_handle == NULL)
     * core_transmit_handle = GNUNET_CORE_notify_transmit_ready(coreAPI, GNUNET_YES,  default_dv_priority, GNUNET_TIME_UNIT_FOREVER_REL, &to->identity, sizeof(p2p_dv_MESSAGE_NeighborInfo), &core_transmit_notify, NULL); */

  }

  if (send_context->fast_gossip_list_head != NULL)      /* If there are other peers in the fast list, schedule right away */
  {
#if DEBUG_DV_PEER_NUMBERS
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "DV SERVICE: still in fast send mode\n");
#endif
    send_context->task =
        GNUNET_SCHEDULER_add_now (&neighbor_send_task, send_context);
  }
  else
  {
#if DEBUG_DV_PEER_NUMBERS
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "DV SERVICE: entering slow send mode\n");
#endif
    send_context->task =
        GNUNET_SCHEDULER_add_delayed (GNUNET_DV_DEFAULT_SEND_INTERVAL,
                                      &neighbor_send_task, send_context);
  }

  return;
}


/**
 * Handle START-message.  This is the first message sent to us
 * by the client (can only be one!).
 *
 * @param cls closure (always NULL)
 * @param client identification of the client
 * @param message the actual message
 */
static void
handle_start (void *cls, struct GNUNET_SERVER_Client *client,
              const struct GNUNET_MessageHeader *message)
{

#if DEBUG_DV
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received `%s' request from client\n",
              "START");
#endif

  client_handle = client;

  GNUNET_SERVER_client_keep (client_handle);
  GNUNET_SERVER_receive_done (client, GNUNET_OK);
}

#if UNSIMPLER
/**
 * Iterate over hash map entries for a distant neighbor,
 * if direct neighbor matches context call send message
 *
 * @param cls closure, a DV_SendContext
 * @param key current key code
 * @param value value in the hash map
 * @return GNUNET_YES if we should continue to
 *         iterate,
 *         GNUNET_NO if not.
 */
int
send_iterator (void *cls, const struct GNUNET_HashCode * key, void *abs_value)
{
  struct DV_SendContext *send_context = cls;
  struct DistantNeighbor *distant_neighbor = abs_value;

  if (memcmp (distant_neighbor->referrer, send_context->direct_peer, sizeof (struct GNUNET_PeerIdentity)) == 0) /* They match, send and free */
  {
    send_message_via (&my_identity, distant_neighbor, send_context);
    return GNUNET_NO;
  }
  return GNUNET_YES;
}
#endif

/**
 * Service server's handler for message send requests (which come
 * bubbling up to us through the DV plugin).
 *
 * @param cls closure
 * @param client identification of the client
 * @param message the actual message
 */
void
handle_dv_send_message (void *cls, struct GNUNET_SERVER_Client *client,
                        const struct GNUNET_MessageHeader *message)
{
  struct GNUNET_DV_SendMessage *send_msg;
  struct GNUNET_DV_SendResultMessage *send_result_msg;
  struct PendingMessage *pending_message;
  size_t address_len;
  size_t message_size;
  struct GNUNET_PeerIdentity *destination;
  struct GNUNET_PeerIdentity *direct;
  struct GNUNET_MessageHeader *message_buf;
  char *temp_pos;
  int offset;
  static struct GNUNET_CRYPTO_HashAsciiEncoded dest_hash;
  struct DV_SendContext *send_context;

#if DEBUG_DV_MESSAGES
  char *cbuf;
  struct GNUNET_MessageHeader *packed_message;
#endif

  if (client_handle == NULL)
  {
    client_handle = client;
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: Setting initial client handle, never received `%s' message?\n",
                "dv", "START");
  }
  else if (client_handle != client)
  {
    client_handle = client;
    /* What should we do in this case, assert fail or just log the warning? */
#if DEBUG_DV
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: Setting client handle (was a different client!)!\n", "dv");
#endif
  }

  GNUNET_assert (ntohs (message->size) > sizeof (struct GNUNET_DV_SendMessage));
  send_msg = (struct GNUNET_DV_SendMessage *) message;

  address_len = ntohl (send_msg->addrlen);
  GNUNET_assert (address_len == sizeof (struct GNUNET_PeerIdentity) * 2);
  message_size =
      ntohs (message->size) - sizeof (struct GNUNET_DV_SendMessage) -
      address_len;
  destination = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity));
  direct = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity));
  message_buf = GNUNET_malloc (message_size);

  temp_pos = (char *) &send_msg[1];     /* Set pointer to end of message */
  offset = 0;                   /* Offset starts at zero */

  memcpy (destination, &temp_pos[offset], sizeof (struct GNUNET_PeerIdentity));
  offset += sizeof (struct GNUNET_PeerIdentity);

  memcpy (direct, &temp_pos[offset], sizeof (struct GNUNET_PeerIdentity));
  offset += sizeof (struct GNUNET_PeerIdentity);


  memcpy (message_buf, &temp_pos[offset], message_size);
  if (memcmp
      (&send_msg->target, destination,
       sizeof (struct GNUNET_PeerIdentity)) != 0)
  {
    GNUNET_CRYPTO_hash_to_enc (&destination->hashPubKey, &dest_hash);   /* GNUNET_i2s won't properly work, need to hash one ourselves */
    dest_hash.encoding[4] = '\0';
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "%s: asked to send message to `%s', but address is for `%s'!",
                "DV SERVICE", GNUNET_i2s (&send_msg->target),
                (const char *) &dest_hash.encoding);
  }

#if DEBUG_DV_MESSAGES
  cbuf = (char *) message_buf;
  offset = 0;
  while (offset < message_size)
  {
    packed_message = (struct GNUNET_MessageHeader *) &cbuf[offset];
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: DV PLUGIN SEND uid %u type %d to %s\n", my_short_id,
                ntohl (send_msg->uid), ntohs (packed_message->type),
                GNUNET_i2s (destination));
    offset += ntohs (packed_message->size);
  }
  /*GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "%s: DV PLUGIN SEND uid %u type %d to %s\n", my_short_id, ntohl(send_msg->uid), ntohs(message_buf->type), GNUNET_i2s(destination)); */
#endif
  GNUNET_CRYPTO_hash_to_enc (&destination->hashPubKey, &dest_hash);     /* GNUNET_i2s won't properly work, need to hash one ourselves */
  dest_hash.encoding[4] = '\0';
  send_context = GNUNET_malloc (sizeof (struct DV_SendContext));

  send_result_msg = GNUNET_malloc (sizeof (struct GNUNET_DV_SendResultMessage));
  send_result_msg->header.size =
      htons (sizeof (struct GNUNET_DV_SendResultMessage));
  send_result_msg->header.type =
      htons (GNUNET_MESSAGE_TYPE_TRANSPORT_DV_SEND_RESULT);
  send_result_msg->uid = send_msg->uid; /* No need to ntohl->htonl this */

  send_context->importance = ntohl (send_msg->priority);
  send_context->timeout = send_msg->timeout;
  send_context->direct_peer = direct;
  send_context->distant_peer = destination;
  send_context->message = message_buf;
  send_context->message_size = message_size;
  send_context->send_result = send_result_msg;
#if DEBUG_DV_MESSAGES
  send_context->uid = send_msg->uid;
#endif

  if (send_message_via (&my_identity, direct, send_context) != GNUNET_YES)
  {
    send_result_msg->result = htons (1);
    pending_message =
        GNUNET_malloc (sizeof (struct PendingMessage) +
                       sizeof (struct GNUNET_DV_SendResultMessage));
    pending_message->msg = (struct GNUNET_MessageHeader *) &pending_message[1];
    memcpy (&pending_message[1], send_result_msg,
            sizeof (struct GNUNET_DV_SendResultMessage));
    GNUNET_free (send_result_msg);

    GNUNET_CONTAINER_DLL_insert_after (plugin_pending_head, plugin_pending_tail,
                                       plugin_pending_tail, pending_message);

    if (client_handle != NULL)
    {
      if (plugin_transmit_handle == NULL)
      {
        plugin_transmit_handle =
            GNUNET_SERVER_notify_transmit_ready (client_handle,
                                                 sizeof (struct
                                                         GNUNET_DV_SendResultMessage),
                                                 GNUNET_TIME_UNIT_FOREVER_REL,
                                                 &transmit_to_plugin, NULL);
      }
      else
      {
        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                    "Failed to queue message for plugin, must be one in progress already!!\n");
      }
    }
    GNUNET_CRYPTO_hash_to_enc (&destination->hashPubKey, &dest_hash);   /* GNUNET_i2s won't properly work, need to hash one ourselves */
    dest_hash.encoding[4] = '\0';
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "%s DV SEND failed to send message to destination `%s' via `%s'\n",
                my_short_id, (const char *) &dest_hash.encoding,
                GNUNET_i2s (direct));
  }

  /* In bizarro world GNUNET_SYSERR indicates that we succeeded */
#if UNSIMPLER
  if (GNUNET_SYSERR !=
      GNUNET_CONTAINER_multihashmap_get_multiple (extended_neighbors,
                                                  &destination->hashPubKey,
                                                  &send_iterator, send_context))
  {
    send_result_msg->result = htons (1);
    pending_message =
        GNUNET_malloc (sizeof (struct PendingMessage) +
                       sizeof (struct GNUNET_DV_SendResultMessage));
    pending_message->msg = (struct GNUNET_MessageHeader *) &pending_message[1];
    memcpy (&pending_message[1], send_result_msg,
            sizeof (struct GNUNET_DV_SendResultMessage));
    GNUNET_free (send_result_msg);

    GNUNET_CONTAINER_DLL_insert_after (plugin_pending_head, plugin_pending_tail,
                                       plugin_pending_tail, pending_message);

    if (client_handle != NULL)
    {
      if (plugin_transmit_handle == NULL)
      {
        plugin_transmit_handle =
            GNUNET_SERVER_notify_transmit_ready (client_handle,
                                                 sizeof (struct
                                                         GNUNET_DV_SendResultMessage),
                                                 GNUNET_TIME_UNIT_FOREVER_REL,
                                                 &transmit_to_plugin, NULL);
      }
      else
      {
        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                    "Failed to queue message for plugin, must be one in progress already!!\n");
      }
    }
    GNUNET_CRYPTO_hash_to_enc (&destination->hashPubKey, &dest_hash);   /* GNUNET_i2s won't properly work, need to hash one ourselves */
    dest_hash.encoding[4] = '\0';
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "%s DV SEND failed to send message to destination `%s' via `%s'\n",
                my_short_id, (const char *) &dest_hash.encoding,
                GNUNET_i2s (direct));
  }
#endif
  GNUNET_free (message_buf);
  GNUNET_free (send_context);
  GNUNET_free (direct);
  GNUNET_free (destination);

  GNUNET_SERVER_receive_done (client, GNUNET_OK);
}

/** Forward declarations **/
static int
handle_dv_gossip_message (void *cls, const struct GNUNET_PeerIdentity *peer,
                          const struct GNUNET_MessageHeader *message,
                          const struct GNUNET_ATS_Information *atsi,
                          unsigned int atsi_count);

static int
handle_dv_disconnect_message (void *cls, const struct GNUNET_PeerIdentity *peer,
                              const struct GNUNET_MessageHeader *message,
                              const struct GNUNET_ATS_Information *atsi,
                              unsigned int atsi_count);
/** End forward declarations **/


/**
 * List of handlers for the messages understood by this
 * service.
 *
 * Hmm... will we need to register some handlers with core and
 * some handlers with our server here?  Because core should be
 * getting the incoming DV messages (from whichever lower level
 * transport) and then our server should be getting messages
 * from the dv_plugin, right?
 */
static struct GNUNET_CORE_MessageHandler core_handlers[] = {
  {&handle_dv_data_message, GNUNET_MESSAGE_TYPE_DV_DATA, 0},
  {&handle_dv_gossip_message, GNUNET_MESSAGE_TYPE_DV_GOSSIP, 0},
  {&handle_dv_disconnect_message, GNUNET_MESSAGE_TYPE_DV_DISCONNECT, 0},
  {NULL, 0, 0}
};

static struct GNUNET_SERVER_MessageHandler plugin_handlers[] = {
  {&handle_dv_send_message, NULL, GNUNET_MESSAGE_TYPE_TRANSPORT_DV_SEND, 0},
  {&handle_start, NULL, GNUNET_MESSAGE_TYPE_DV_START, 0},
  {NULL, NULL, 0, 0}
};

/**
 * Free a DistantNeighbor node, including removing it
 * from the referer's list.
 */
static void
distant_neighbor_free (struct DistantNeighbor *referee)
{
  struct DirectNeighbor *referrer;

  referrer = referee->referrer;
  if (referrer != NULL)
  {
    GNUNET_CONTAINER_DLL_remove (referrer->referee_head, referrer->referee_tail,
                                 referee);
  }
  GNUNET_CONTAINER_heap_remove_node (referee->max_loc);
  GNUNET_CONTAINER_heap_remove_node (referee->min_loc);
  GNUNET_CONTAINER_multihashmap_remove_all (extended_neighbors,
                                            &referee->identity.hashPubKey);
  GNUNET_free_non_null (referee->pkey);
  GNUNET_free (referee);
}

/**
 * Free a DirectNeighbor node, including removing it
 * from the referer's list.
 */
static void
direct_neighbor_free (struct DirectNeighbor *direct)
{
  struct NeighborSendContext *send_context;
  struct FastGossipNeighborList *about_list;
  struct FastGossipNeighborList *prev_about;

  send_context = direct->send_context;

  if (send_context->task != GNUNET_SCHEDULER_NO_TASK)
    GNUNET_SCHEDULER_cancel (send_context->task);

  about_list = send_context->fast_gossip_list_head;
  while (about_list != NULL)
  {
    GNUNET_CONTAINER_DLL_remove (send_context->fast_gossip_list_head,
                                 send_context->fast_gossip_list_tail,
                                 about_list);
    prev_about = about_list;
    about_list = about_list->next;
    GNUNET_free (prev_about);
  }
  GNUNET_free (send_context);
  GNUNET_free (direct);
}

/**
 * Multihashmap iterator for sending out disconnect messages
 * for a peer.
 *
 * @param cls the peer that was disconnected
 * @param key key value stored under
 * @param value the direct neighbor to send disconnect to
 *
 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
 */
static int
schedule_disconnect_messages (void *cls, const struct GNUNET_HashCode * key,
                              void *value)
{
  struct DisconnectContext *disconnect_context = cls;
  struct DirectNeighbor *disconnected = disconnect_context->direct;
  struct DirectNeighbor *notify = value;
  struct PendingMessage *pending_message;
  p2p_dv_MESSAGE_Disconnect *disconnect_message;

  if (memcmp
      (&notify->identity, &disconnected->identity,
       sizeof (struct GNUNET_PeerIdentity)) == 0)
    return GNUNET_YES;          /* Don't send disconnect message to peer that disconnected! */

  pending_message =
      GNUNET_malloc (sizeof (struct PendingMessage) +
                     sizeof (p2p_dv_MESSAGE_Disconnect));
  pending_message->msg = (struct GNUNET_MessageHeader *) &pending_message[1];
  pending_message->importance = default_dv_priority;
  pending_message->timeout = GNUNET_TIME_UNIT_FOREVER_REL;
  memcpy (&pending_message->recipient, &notify->identity,
          sizeof (struct GNUNET_PeerIdentity));
  pending_message->msg_size = sizeof (p2p_dv_MESSAGE_Disconnect);
  disconnect_message = (p2p_dv_MESSAGE_Disconnect *) pending_message->msg;
  disconnect_message->header.size = htons (sizeof (p2p_dv_MESSAGE_Disconnect));
  disconnect_message->header.type = htons (GNUNET_MESSAGE_TYPE_DV_DISCONNECT);
  disconnect_message->peer_id = htonl (disconnect_context->distant->our_id);

  GNUNET_CONTAINER_DLL_insert_after (core_pending_head, core_pending_tail,
                                     core_pending_tail, pending_message);

  GNUNET_SCHEDULER_add_now (try_core_send, NULL);
  /*if (core_transmit_handle == NULL)
   * core_transmit_handle = GNUNET_CORE_notify_transmit_ready(coreAPI, GNUNET_YES, default_dv_priority, GNUNET_TIME_UNIT_FOREVER_REL, &notify->identity, sizeof(p2p_dv_MESSAGE_Disconnect), &core_transmit_notify, NULL); */

  return GNUNET_YES;
}

/**
 * Multihashmap iterator for freeing extended neighbors.
 *
 * @param cls NULL
 * @param key key value stored under
 * @param value the distant neighbor to be freed
 *
 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
 */
static int
free_extended_neighbors (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct DistantNeighbor *distant = value;

  distant_neighbor_free (distant);
  return GNUNET_YES;
}

/**
 * Multihashmap iterator for freeing direct neighbors.
 *
 * @param cls NULL
 * @param key key value stored under
 * @param value the direct neighbor to be freed
 *
 * @return GNUNET_YES to continue iteration, GNUNET_NO to stop
 */
static int
free_direct_neighbors (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct DirectNeighbor *direct = value;

  direct_neighbor_free (direct);
  return GNUNET_YES;
}


/**
 * Task run during shutdown.
 *
 * @param cls unused
 * @param tc unused
 */
static void
shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
#if DEBUG_DV
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "calling CORE_DISCONNECT\n");
  GNUNET_CONTAINER_multihashmap_iterate (extended_neighbors, &print_neighbors,
                                         NULL);
#endif
  GNUNET_CONTAINER_multihashmap_iterate (extended_neighbors,
                                         &free_extended_neighbors, NULL);
  GNUNET_CONTAINER_multihashmap_destroy (extended_neighbors);
  GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
                                         &free_direct_neighbors, NULL);
  GNUNET_CONTAINER_multihashmap_destroy (direct_neighbors);

  GNUNET_CONTAINER_heap_destroy (neighbor_max_heap);
  GNUNET_CONTAINER_heap_destroy (neighbor_min_heap);

  GNUNET_CORE_disconnect (coreAPI);
  coreAPI = NULL;
  GNUNET_PEERINFO_disconnect (peerinfo_handle);
  GNUNET_SERVER_mst_destroy (coreMST);
  GNUNET_free_non_null (my_short_id);
#if DEBUG_DV
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "CORE_DISCONNECT completed\n");
#endif
}

/**
 * To be called on core init/fail.
 */
void
core_init (void *cls, struct GNUNET_CORE_Handle *server,
           const struct GNUNET_PeerIdentity *identity)
{

  if (server == NULL)
  {
    GNUNET_SCHEDULER_cancel (cleanup_task);
    GNUNET_SCHEDULER_add_now (&shutdown_task, NULL);
    return;
  }
#if DEBUG_DV
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Core connection initialized, I am peer: %s\n", "dv",
              GNUNET_i2s (identity));
#endif
  memcpy (&my_identity, identity, sizeof (struct GNUNET_PeerIdentity));
  my_short_id = GNUNET_strdup (GNUNET_i2s (&my_identity));
  coreAPI = server;
}


#if PKEY_NO_NEIGHBOR_ON_ADD
/**
 * Iterator over hash map entries.
 *
 * @param cls closure
 * @param key current key code
 * @param value value in the hash map
 * @return GNUNET_YES if we should continue to
 *         iterate,
 *         GNUNET_NO if not.
 */
static int
add_pkey_to_extended (void *cls, const struct GNUNET_HashCode * key, void *abs_value)
{
  struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pkey = cls;
  struct DistantNeighbor *distant_neighbor = abs_value;

  if (distant_neighbor->pkey == NULL)
  {
    distant_neighbor->pkey =
        GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
    memcpy (distant_neighbor->pkey, pkey,
            sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
  }

  return GNUNET_YES;
}
#endif

/**
 * Iterator over hash map entries.
 *
 * @param cls closure
 * @param key current key code
 * @param value value in the hash map
 * @return GNUNET_YES if we should continue to
 *         iterate,
 *         GNUNET_NO if not.
 */
static int
update_matching_neighbors (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct NeighborUpdateInfo *update_info = cls;
  struct DistantNeighbor *distant_neighbor = value;

  if (update_info->referrer == distant_neighbor->referrer)      /* Direct neighbor matches, update it's info and return GNUNET_NO */
  {
    /* same referrer, cost change! */
    GNUNET_CONTAINER_heap_update_cost (neighbor_max_heap,
                                       update_info->neighbor->max_loc,
                                       update_info->cost);
    GNUNET_CONTAINER_heap_update_cost (neighbor_min_heap,
                                       update_info->neighbor->min_loc,
                                       update_info->cost);
    update_info->neighbor->last_activity = update_info->now;
    update_info->neighbor->cost = update_info->cost;
    update_info->neighbor->referrer_id = update_info->referrer_peer_id;
    return GNUNET_NO;
  }

  return GNUNET_YES;
}


/**
 * Iterate over all current direct peers, add DISTANT newly connected
 * peer to the fast gossip list for that peer so we get DV routing
 * information out as fast as possible!
 *
 * @param cls the newly connected neighbor we will gossip about
 * @param key the hashcode of the peer
 * @param value the direct neighbor we should gossip to
 *
 * @return GNUNET_YES to continue iteration, GNUNET_NO otherwise
 */
static int
add_distant_all_direct_neighbors (void *cls, const struct GNUNET_HashCode * key,
                                  void *value)
{
  struct DirectNeighbor *direct = (struct DirectNeighbor *) value;
  struct DistantNeighbor *distant = (struct DistantNeighbor *) cls;
  struct NeighborSendContext *send_context = direct->send_context;
  struct FastGossipNeighborList *gossip_entry;

#if DEBUG_DV
  char *encPeerAbout;
  char *encPeerTo;
#endif

  if (distant == NULL)
  {
    return GNUNET_YES;
  }

  if (memcmp
      (&direct->identity, &distant->identity,
       sizeof (struct GNUNET_PeerIdentity)) == 0)
  {
    return GNUNET_YES;          /* Don't gossip to a peer about itself! */
  }

#if SUPPORT_HIDING
  if (distant->hidden == GNUNET_YES)
    return GNUNET_YES;          /* This peer should not be gossipped about (hidden) */
#endif
  gossip_entry = GNUNET_malloc (sizeof (struct FastGossipNeighborList));
  gossip_entry->about = distant;

  GNUNET_CONTAINER_DLL_insert_after (send_context->fast_gossip_list_head,
                                     send_context->fast_gossip_list_tail,
                                     send_context->fast_gossip_list_tail,
                                     gossip_entry);
#if DEBUG_DV
  encPeerAbout = GNUNET_strdup (GNUNET_i2s (&distant->identity));
  encPeerTo = GNUNET_strdup (GNUNET_i2s (&direct->identity));

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Fast send info about peer %s id %u for directly connected peer %s\n",
              GNUNET_i2s (&my_identity), encPeerAbout, distant->our_id,
              encPeerTo);
  GNUNET_free (encPeerAbout);
  GNUNET_free (encPeerTo);
#endif
  /*if (send_context->task != GNUNET_SCHEDULER_NO_TASK)
   * GNUNET_SCHEDULER_cancel(send_context->task); */

  send_context->task =
      GNUNET_SCHEDULER_add_now (&neighbor_send_task, send_context);
  return GNUNET_YES;
}

/**
 * Callback for hello address creation.
 *
 * @param cls closure, a struct HelloContext
 * @param max maximum number of bytes that can be written to buf
 * @param buf where to write the address information
 *
 * @return number of bytes written, 0 to signal the
 *         end of the iteration.
 */
static size_t
generate_hello_address (void *cls, size_t max, void *buf)
{
  struct HelloContext *hello_context = cls;
  struct GNUNET_HELLO_Address hello_address;
  char *addr_buffer;
  size_t offset;
  size_t size;
  size_t ret;

  if (hello_context->addresses_to_add == 0)
    return 0;

  /* Hello "address" will be concatenation of distant peer and direct peer identities */
  size = 2 * sizeof (struct GNUNET_PeerIdentity);
  GNUNET_assert (max >= size);

  addr_buffer = GNUNET_malloc (size);
  offset = 0;
  /* Copy the distant peer identity to buffer */
  memcpy (addr_buffer, &hello_context->distant_peer,
          sizeof (struct GNUNET_PeerIdentity));
  offset += sizeof (struct GNUNET_PeerIdentity);
  /* Copy the direct peer identity to buffer */
  memcpy (&addr_buffer[offset], hello_context->direct_peer,
          sizeof (struct GNUNET_PeerIdentity));
  memset (&hello_address.peer, 0, sizeof (struct GNUNET_PeerIdentity));
  hello_address.address = addr_buffer;
  hello_address.transport_name = "dv";
  hello_address.address_length = size;
  ret =
      GNUNET_HELLO_add_address (&hello_address,
                                GNUNET_TIME_relative_to_absolute
                                (GNUNET_TIME_UNIT_HOURS), buf, max);

  hello_context->addresses_to_add--;

  GNUNET_free (addr_buffer);
  return ret;
}


/**
 * Handles when a peer is either added due to being newly connected
 * or having been gossiped about, also called when the cost for a neighbor
 * needs to be updated.
 *
 * @param peer identity of the peer whose info is being added/updated
 * @param pkey public key of the peer whose info is being added/updated
 * @param referrer_peer_id id to use when sending to 'peer'
 * @param referrer if this is a gossiped peer, who did we hear it from?
 * @param cost the cost of communicating with this peer via 'referrer'
 *
 * @return the added neighbor, the updated neighbor or NULL (neighbor
 *         not added)
 */
static struct DistantNeighbor *
addUpdateNeighbor (const struct GNUNET_PeerIdentity *peer,
                   struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pkey,
                   unsigned int referrer_peer_id,
                   struct DirectNeighbor *referrer, unsigned int cost)
{
  struct DistantNeighbor *neighbor;
  struct DistantNeighbor *max;
  struct GNUNET_TIME_Absolute now;
  struct NeighborUpdateInfo *neighbor_update;
  struct HelloContext *hello_context;
  struct GNUNET_HELLO_Message *hello_msg;
  unsigned int our_id;
  char *addr1;
  char *addr2;
  int i;

#if DEBUG_DV_PEER_NUMBERS
  char *encAbout;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s Received sender id (%u)!\n",
              "DV SERVICE", referrer_peer_id);
#endif

  now = GNUNET_TIME_absolute_get ();
  neighbor =
      GNUNET_CONTAINER_multihashmap_get (extended_neighbors, &peer->hashPubKey);
  neighbor_update = GNUNET_malloc (sizeof (struct NeighborUpdateInfo));
  neighbor_update->neighbor = neighbor;
  neighbor_update->cost = cost;
  neighbor_update->now = now;
  neighbor_update->referrer = referrer;
  neighbor_update->referrer_peer_id = referrer_peer_id;

  if (neighbor != NULL)
  {
#if USE_PEER_ID
    memcpy (&our_id, &neighbor->identity, sizeof (unsigned int));
#else
    our_id = neighbor->our_id;
#endif
  }
  else
  {
#if USE_PEER_ID
    memcpy (&our_id, peer, sizeof (unsigned int));
#else
    our_id =
        GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG,
                                  RAND_MAX - 1) + 1;
#endif
  }

  /* Either we do not know this peer, or we already do but via a different immediate peer */
  if ((neighbor == NULL) ||
      (GNUNET_CONTAINER_multihashmap_get_multiple
       (extended_neighbors, &peer->hashPubKey, &update_matching_neighbors,
        neighbor_update) != GNUNET_SYSERR))
  {
#if AT_MOST_ONE
    if ((neighbor != NULL) && (cost < neighbor->cost))  /* New cost is less than old, remove old */
    {
      distant_neighbor_free (neighbor);
    }
    else if (neighbor != NULL)  /* Only allow one DV connection to each peer */
    {
      return NULL;
    }
#endif
    /* new neighbor! */
    if (cost > fisheye_depth)
    {
      /* too costly */
      GNUNET_free (neighbor_update);
      return NULL;
    }

#if DEBUG_DV_PEER_NUMBERS
    encAbout = GNUNET_strdup (GNUNET_i2s (peer));
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: %s Chose NEW id (%u) for peer %s!\n",
                GNUNET_i2s (&my_identity), "DV SERVICE", our_id, encAbout);
    GNUNET_free (encAbout);
#endif

    if (max_table_size <=
        GNUNET_CONTAINER_multihashmap_size (extended_neighbors))
    {
      /* remove most expensive entry */
      max = GNUNET_CONTAINER_heap_peek (neighbor_max_heap);
      GNUNET_assert (max != NULL);
      if (cost > max->cost)
      {
        /* new entry most expensive, don't create */
        GNUNET_free (neighbor_update);
        return NULL;
      }
      if (max->cost > 1)
      {
        /* only free if this is not a direct connection;
         * we could theoretically have more direct
         * connections than DV entries allowed total! */
        distant_neighbor_free (max);
      }
    }

    neighbor = GNUNET_malloc (sizeof (struct DistantNeighbor));
    GNUNET_CONTAINER_DLL_insert (referrer->referee_head, referrer->referee_tail,
                                 neighbor);
    neighbor->max_loc =
        GNUNET_CONTAINER_heap_insert (neighbor_max_heap, neighbor, cost);
    neighbor->min_loc =
        GNUNET_CONTAINER_heap_insert (neighbor_min_heap, neighbor, cost);
    neighbor->referrer = referrer;
    memcpy (&neighbor->identity, peer, sizeof (struct GNUNET_PeerIdentity));
    if (pkey != NULL)           /* pkey will be null on direct neighbor addition */
    {
      neighbor->pkey =
          GNUNET_malloc (sizeof
                         (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
      memcpy (neighbor->pkey, pkey,
              sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
    }
    else
      neighbor->pkey = pkey;

    neighbor->last_activity = now;
    neighbor->cost = cost;
    neighbor->referrer_id = referrer_peer_id;
    neighbor->our_id = our_id;
    neighbor->hidden =
        (cost ==
         DIRECT_NEIGHBOR_COST)
        ? (GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, 4) ==
           0) : GNUNET_NO;

    GNUNET_CONTAINER_multihashmap_put (extended_neighbors, &peer->hashPubKey,
                                       neighbor,
                                       GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
    if (referrer_peer_id != 0)
    {
      for (i = 0; i < MAX_OUTSTANDING_MESSAGES; i++)
      {
        if (referrer->pending_messages[i].sender_id == referrer_peer_id)        /* We have a queued message from just learned about peer! */
        {
#if DEBUG_DV_MESSAGES
          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                      "%s: learned about peer %llu from which we have a previous unknown message, processing!\n",
                      my_short_id, referrer_peer_id);
#endif
          struct GNUNET_ATS_Information atsi[2];

          atsi[0].type = htonl (GNUNET_ATS_QUALITY_NET_DISTANCE);
          atsi[0].value = htonl (referrer->pending_messages[i].distance);
          atsi[1].type = htonl (GNUNET_ATS_QUALITY_NET_DELAY);
          atsi[1].value =
              htonl ((uint32_t) referrer->pending_messages[i].
                     latency.rel_value);
          handle_dv_data_message (NULL, &referrer->pending_messages[i].sender,
                                  referrer->pending_messages[i].message, atsi,
                                  2);
          GNUNET_free (referrer->pending_messages[i].message);
          referrer->pending_messages[i].sender_id = 0;
        }
      }
    }
    if ((cost != DIRECT_NEIGHBOR_COST) && (neighbor->pkey != NULL))
    {
      /* Added neighbor, now send HELLO to transport */
      hello_context = GNUNET_malloc (sizeof (struct HelloContext));
      hello_context->direct_peer = &referrer->identity;
      memcpy (&hello_context->distant_peer, peer,
              sizeof (struct GNUNET_PeerIdentity));
      hello_context->addresses_to_add = 1;
      hello_msg =
          GNUNET_HELLO_create (pkey, &generate_hello_address, hello_context);
      GNUNET_assert (memcmp
                     (hello_context->direct_peer, &hello_context->distant_peer,
                      sizeof (struct GNUNET_PeerIdentity)) != 0);
      addr1 = GNUNET_strdup (GNUNET_i2s (hello_context->direct_peer));
      addr2 = GNUNET_strdup (GNUNET_i2s (&hello_context->distant_peer));
#if DEBUG_DV
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "%s: GIVING HELLO size %d for %s via %s to TRANSPORT\n",
                  my_short_id, GNUNET_HELLO_size (hello_msg), addr2, addr1);
#endif
      GNUNET_free (addr1);
      GNUNET_free (addr2);
      send_to_plugin (hello_context->direct_peer,
                      GNUNET_HELLO_get_header (hello_msg),
                      GNUNET_HELLO_size (hello_msg),
                      &hello_context->distant_peer, cost);
      GNUNET_free (hello_context);
      GNUNET_free (hello_msg);
    }

  }
  else
  {
#if DEBUG_DV_GOSSIP
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: Already know peer %s distance %d, referrer id %d!\n", "dv",
                GNUNET_i2s (peer), cost, referrer_peer_id);
#endif
  }
#if DEBUG_DV
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s: Size of extended_neighbors is %d\n",
              "dv", GNUNET_CONTAINER_multihashmap_size (extended_neighbors));
#endif

  GNUNET_free (neighbor_update);
  return neighbor;
}


/**
 * Core handler for dv disconnect messages.  These will be used
 * by us to tell transport via the dv plugin that a peer can
 * no longer be contacted by us via a certain address.  We should
 * then propagate these messages on, given that the distance to
 * the peer indicates we would have gossiped about it to others.
 *
 * @param cls closure
 * @param peer peer which sent the message (immediate sender)
 * @param message the message
 * @param atsi performance data
 * @param atsi_count number of entries in atsi
 */
static int
handle_dv_disconnect_message (void *cls, const struct GNUNET_PeerIdentity *peer,
                              const struct GNUNET_MessageHeader *message,
                              const struct GNUNET_ATS_Information *atsi,
                              unsigned int atsi_count)
{
  struct DirectNeighbor *referrer;
  struct DistantNeighbor *distant;
  p2p_dv_MESSAGE_Disconnect *enc_message =
      (p2p_dv_MESSAGE_Disconnect *) message;

  if (ntohs (message->size) < sizeof (p2p_dv_MESSAGE_Disconnect))
  {
    return GNUNET_SYSERR;       /* invalid message */
  }

  referrer =
      GNUNET_CONTAINER_multihashmap_get (direct_neighbors, &peer->hashPubKey);
  if (referrer == NULL)
    return GNUNET_OK;

  distant = referrer->referee_head;
  while (distant != NULL)
  {
    if (distant->referrer_id == ntohl (enc_message->peer_id))
    {
      distant_neighbor_free (distant);
      distant = referrer->referee_head;
    }
    else
      distant = distant->next;
  }

  return GNUNET_OK;
}


/**
 * Core handler for dv gossip messages.  These will be used
 * by us to create a HELLO message for the newly peer containing
 * which direct peer we can connect through, and what the cost
 * is.  This HELLO will then be scheduled for validation by the
 * transport service so that it can be used by all others.
 *
 * @param cls closure
 * @param peer peer which sent the message (immediate sender)
 * @param message the message
 * @param atsi performance data
 * @param atsi_count number of entries in atsi
 */
static int
handle_dv_gossip_message (void *cls, const struct GNUNET_PeerIdentity *peer,
                          const struct GNUNET_MessageHeader *message,
                          const struct GNUNET_ATS_Information *atsi,
                          unsigned int atsi_count)
{
  struct DirectNeighbor *referrer;
  p2p_dv_MESSAGE_NeighborInfo *enc_message =
      (p2p_dv_MESSAGE_NeighborInfo *) message;

  if (ntohs (message->size) < sizeof (p2p_dv_MESSAGE_NeighborInfo))
  {
    return GNUNET_SYSERR;       /* invalid message */
  }

#if DEBUG_DV_GOSSIP_RECEIPT
  char *encPeerAbout;
  char *encPeerFrom;

  encPeerAbout = GNUNET_strdup (GNUNET_i2s (&enc_message->neighbor));
  encPeerFrom = GNUNET_strdup (GNUNET_i2s (peer));
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Received %s message from peer %s about peer %s id %u distance %d!\n",
              GNUNET_i2s (&my_identity), "DV GOSSIP", encPeerFrom, encPeerAbout,
              ntohl (enc_message->neighbor_id), ntohl (enc_message->cost) + 1);
  GNUNET_free (encPeerAbout);
  GNUNET_free (encPeerFrom);
#endif

  referrer =
      GNUNET_CONTAINER_multihashmap_get (direct_neighbors, &peer->hashPubKey);
  if (referrer == NULL)
    return GNUNET_OK;

  addUpdateNeighbor (&enc_message->neighbor, &enc_message->pkey,
                     ntohl (enc_message->neighbor_id), referrer,
                     ntohl (enc_message->cost) + 1);

  return GNUNET_OK;
}


/**
 * Iterate over all currently known peers, add them to the
 * fast gossip list for this peer so we get DV routing information
 * out as fast as possible!
 *
 * @param cls the direct neighbor we will gossip to
 * @param key the hashcode of the peer
 * @param value the distant neighbor we should add to the list
 *
 * @return GNUNET_YES to continue iteration, GNUNET_NO otherwise
 */
static int
add_all_extended_peers (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct NeighborSendContext *send_context = (struct NeighborSendContext *) cls;
  struct DistantNeighbor *distant = (struct DistantNeighbor *) value;
  struct FastGossipNeighborList *gossip_entry;

  if (memcmp
      (&send_context->toNeighbor->identity, &distant->identity,
       sizeof (struct GNUNET_PeerIdentity)) == 0)
    return GNUNET_YES;          /* Don't gossip to a peer about itself! */

#if SUPPORT_HIDING
  if (distant->hidden == GNUNET_YES)
    return GNUNET_YES;          /* This peer should not be gossipped about (hidden) */
#endif
  gossip_entry = GNUNET_malloc (sizeof (struct FastGossipNeighborList));
  gossip_entry->about = distant;

  GNUNET_CONTAINER_DLL_insert_after (send_context->fast_gossip_list_head,
                                     send_context->fast_gossip_list_tail,
                                     send_context->fast_gossip_list_tail,
                                     gossip_entry);

  return GNUNET_YES;
}

#if INSANE_GOSSIP
/**
 * Iterator over hash map entries.
 *
 * @param cls closure
 * @param key current key code
 * @param value value in the hash map
 * @return GNUNET_YES if we should continue to
 *         iterate,
 *         GNUNET_NO if not.
 */
static int
gossip_all_to_all_iterator (void *cls, const struct GNUNET_HashCode * key,
                            void *abs_value)
{
  struct DirectNeighbor *direct = abs_value;

  GNUNET_CONTAINER_multihashmap_iterate (extended_neighbors,
                                         &add_all_extended_peers,
                                         direct->send_context);

  if (direct->send_context->task != GNUNET_SCHEDULER_NO_TASK)
    GNUNET_SCHEDULER_cancel (direct->send_context->task);

  direct->send_context->task =
      GNUNET_SCHEDULER_add_now (&neighbor_send_task, direct->send_context);
  return GNUNET_YES;
}

/**
 * Task run during shutdown.
 *
 * @param cls unused
 * @param tc unused
 */
static void
gossip_all_to_all (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
                                         &gossip_all_to_all_iterator, NULL);

  GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply
                                (GNUNET_TIME_UNIT_SECONDS, 5),
                                &gossip_all_to_all, NULL);

}
#endif
/**
 * Iterate over all current direct peers, add newly connected peer
 * to the fast gossip list for that peer so we get DV routing
 * information out as fast as possible!
 *
 * @param cls the newly connected neighbor we will gossip about
 * @param key the hashcode of the peer
 * @param value the direct neighbor we should gossip to
 *
 * @return GNUNET_YES to continue iteration, GNUNET_NO otherwise
 */
static int
add_all_direct_neighbors (void *cls, const struct GNUNET_HashCode * key, void *value)
{
  struct DirectNeighbor *direct = (struct DirectNeighbor *) value;
  struct DirectNeighbor *to = (struct DirectNeighbor *) cls;
  struct DistantNeighbor *distant;
  struct NeighborSendContext *send_context = direct->send_context;
  struct FastGossipNeighborList *gossip_entry;
  char *direct_id;


  distant =
      GNUNET_CONTAINER_multihashmap_get (extended_neighbors,
                                         &to->identity.hashPubKey);
  if (distant == NULL)
  {
    return GNUNET_YES;
  }

  if (memcmp
      (&direct->identity, &to->identity,
       sizeof (struct GNUNET_PeerIdentity)) == 0)
  {
    return GNUNET_YES;          /* Don't gossip to a peer about itself! */
  }

#if SUPPORT_HIDING
  if (distant->hidden == GNUNET_YES)
    return GNUNET_YES;          /* This peer should not be gossipped about (hidden) */
#endif
  direct_id = GNUNET_strdup (GNUNET_i2s (&direct->identity));
#if DEBUG_DV_GOSSIP
  GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
              "%s: adding peer %s to fast send list for %s\n", my_short_id,
              GNUNET_i2s (&distant->identity), direct_id);
#endif
  GNUNET_free (direct_id);
  gossip_entry = GNUNET_malloc (sizeof (struct FastGossipNeighborList));
  gossip_entry->about = distant;

  GNUNET_CONTAINER_DLL_insert_after (send_context->fast_gossip_list_head,
                                     send_context->fast_gossip_list_tail,
                                     send_context->fast_gossip_list_tail,
                                     gossip_entry);
  if (send_context->task != GNUNET_SCHEDULER_NO_TASK)
    GNUNET_SCHEDULER_cancel (send_context->task);

  send_context->task =
      GNUNET_SCHEDULER_add_now (&neighbor_send_task, send_context);
  //tc.reason = GNUNET_SCHEDULER_REASON_TIMEOUT;
  //neighbor_send_task(send_context, &tc);
  return GNUNET_YES;
}

/**
 * Type of an iterator over the hosts.  Note that each
 * host will be called with each available protocol.
 *
 * @param cls closure
 * @param peer id of the peer, NULL for last call
 * @param hello hello message for the peer (can be NULL)
 * @param err_msg NULL if successful, otherwise contains error message
 */
static void
process_peerinfo (void *cls, const struct GNUNET_PeerIdentity *peer,
                  const struct GNUNET_HELLO_Message *hello, const char *err_msg)
{
  struct PeerIteratorContext *peerinfo_iterator = cls;
  struct DirectNeighbor *neighbor = peerinfo_iterator->neighbor;
  struct DistantNeighbor *distant = peerinfo_iterator->distant;

#if DEBUG_DV_PEER_NUMBERS
  char *neighbor_pid;
#endif
  int sent;

  if (err_msg != NULL)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                _("Error in communication with PEERINFO service\n"));
    /* return; */
  }
  if (peer == NULL)
  {
    if (distant->pkey == NULL)
    {
#if DEBUG_DV
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                  "Failed to get peerinfo information for this peer, retrying!\n");
#endif
      peerinfo_iterator->ic =
          GNUNET_PEERINFO_iterate (peerinfo_handle,
                                   &peerinfo_iterator->neighbor->identity,
                                   GNUNET_TIME_relative_multiply
                                   (GNUNET_TIME_UNIT_SECONDS, 3),
                                   &process_peerinfo, peerinfo_iterator);
    }
    else
    {
      GNUNET_free (peerinfo_iterator);
    }
    return;
  }

  if (memcmp
      (&neighbor->identity, peer, sizeof (struct GNUNET_PeerIdentity) != 0))
    return;

  if ((hello != NULL) &&
      (GNUNET_HELLO_get_key (hello, &neighbor->pkey) == GNUNET_OK))
  {
    if (distant->pkey == NULL)
    {
      distant->pkey =
          GNUNET_malloc (sizeof
                         (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
      memcpy (distant->pkey, &neighbor->pkey,
              sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded));
    }

    sent =
        GNUNET_CONTAINER_multihashmap_iterate (extended_neighbors,
                                               &add_all_extended_peers,
                                               neighbor->send_context);
    if (stats != NULL)
    {
      GNUNET_STATISTICS_update (stats,
                                "# distant peers gossiped to direct neighbors",
                                sent, GNUNET_NO);
    }
#if DEBUG_DV_PEER_NUMBERS
    neighbor_pid = GNUNET_strdup (GNUNET_i2s (&neighbor->identity));
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: Gossipped %d extended peers to %s\n",
                GNUNET_i2s (&my_identity), sent, neighbor_pid);
#endif
    sent =
        GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
                                               &add_all_direct_neighbors,
                                               neighbor);
    if (stats != NULL)
    {
      GNUNET_STATISTICS_update (stats,
                                "# direct peers gossiped to direct neighbors",
                                sent, GNUNET_NO);
    }
#if DEBUG_DV_PEER_NUMBERS
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: Gossipped about %s to %d direct peers\n",
                GNUNET_i2s (&my_identity), neighbor_pid, sent);
    GNUNET_free (neighbor_pid);
#endif
    neighbor->send_context->task =
        GNUNET_SCHEDULER_add_now (&neighbor_send_task, neighbor->send_context);
  }
}


/**
 * Method called whenever a peer connects.
 *
 * @param cls closure
 * @param peer peer identity this notification is about
 * @param atsi performance data
 * @param atsi_count number of entries in atsi
 */
static void
handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
                     const struct GNUNET_ATS_Information *atsi,
                     unsigned int atsi_count)
{
  struct DirectNeighbor *neighbor;
  struct DistantNeighbor *about;
  struct PeerIteratorContext *peerinfo_iterator;
  int sent;

  uint32_t distance;

  /* Check for connect to self message */
  if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
    return;

  distance = get_atsi_distance (atsi, atsi_count);
  if ((distance == DIRECT_NEIGHBOR_COST) &&
      (GNUNET_CONTAINER_multihashmap_get (direct_neighbors, &peer->hashPubKey)
       == NULL))
  {
    peerinfo_iterator = GNUNET_malloc (sizeof (struct PeerIteratorContext));
    neighbor = GNUNET_malloc (sizeof (struct DirectNeighbor));
    neighbor->send_context =
        GNUNET_malloc (sizeof (struct NeighborSendContext));
    neighbor->send_context->toNeighbor = neighbor;
    memcpy (&neighbor->identity, peer, sizeof (struct GNUNET_PeerIdentity));

    GNUNET_assert (GNUNET_SYSERR !=
                   GNUNET_CONTAINER_multihashmap_put (direct_neighbors,
                                                      &peer->hashPubKey,
                                                      neighbor,
                                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
    about = addUpdateNeighbor (peer, NULL, 0, neighbor, DIRECT_NEIGHBOR_COST);
    peerinfo_iterator->distant = about;
    peerinfo_iterator->neighbor = neighbor;
    peerinfo_iterator->ic =
        GNUNET_PEERINFO_iterate (peerinfo_handle, peer,
                                 GNUNET_TIME_relative_multiply
                                 (GNUNET_TIME_UNIT_SECONDS, 3),
                                 &process_peerinfo, peerinfo_iterator);

    if ((about != NULL) && (about->pkey == NULL))
    {
#if DEBUG_DV
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Newly added peer %s has NULL pkey!\n", GNUNET_i2s (peer));
#endif
    }
    else if (about != NULL)
    {
      GNUNET_free (peerinfo_iterator);
    }
  }
  else
  {
    about =
        GNUNET_CONTAINER_multihashmap_get (extended_neighbors,
                                           &peer->hashPubKey);
    if ((GNUNET_CONTAINER_multihashmap_get (direct_neighbors, &peer->hashPubKey)
         == NULL) && (about != NULL))
    {
      sent =
          GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
                                                 &add_distant_all_direct_neighbors,
                                                 about);
      if (stats != NULL)
        GNUNET_STATISTICS_update (stats,
                                  "# direct peers gossiped to new direct neighbors",
                                  sent, GNUNET_NO);
    }
#if DEBUG_DV
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s: Distance (%d) greater than %d or already know about peer (%s), not re-adding!\n",
                "dv", distance, DIRECT_NEIGHBOR_COST, GNUNET_i2s (peer));
#endif
    return;
  }
}

/**
 * Method called whenever a given peer disconnects.
 *
 * @param cls closure
 * @param peer peer identity this notification is about
 */
void
handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer)
{
  struct DirectNeighbor *neighbor;
  struct DistantNeighbor *referee;
  struct FindDestinationContext fdc;
  struct DisconnectContext disconnect_context;
  struct PendingMessage *pending_pos;

#if DEBUG_DV
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Receives core peer disconnect message!\n", "dv");
#endif

  /* Check for disconnect from self message */
  if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
    return;

  neighbor =
      GNUNET_CONTAINER_multihashmap_get (direct_neighbors, &peer->hashPubKey);

  if (neighbor == NULL)
  {
    return;
  }

  pending_pos = core_pending_head;
  while (NULL != pending_pos)
  {
    if (0 ==
        memcmp (&pending_pos->recipient, &neighbor->identity,
                sizeof (struct GNUNET_PeerIdentity)))
    {
      GNUNET_CONTAINER_DLL_remove (core_pending_head, core_pending_tail,
                                   pending_pos);
      pending_pos = core_pending_head;
    }
    else
      pending_pos = pending_pos->next;
  }

  while (NULL != (referee = neighbor->referee_head))
    distant_neighbor_free (referee);

  fdc.dest = NULL;
  fdc.tid = 0;

  GNUNET_CONTAINER_multihashmap_iterate (extended_neighbors, &find_distant_peer,
                                         &fdc);

  if (fdc.dest != NULL)
  {
    disconnect_context.direct = neighbor;
    disconnect_context.distant = fdc.dest;
    GNUNET_CONTAINER_multihashmap_iterate (direct_neighbors,
                                           &schedule_disconnect_messages,
                                           &disconnect_context);
  }

  GNUNET_assert (neighbor->referee_tail == NULL);
  if (GNUNET_NO ==
      GNUNET_CONTAINER_multihashmap_remove (direct_neighbors, &peer->hashPubKey,
                                            neighbor))
  {
    GNUNET_break (0);
  }
  if ((neighbor->send_context != NULL) &&
      (neighbor->send_context->task != GNUNET_SCHEDULER_NO_TASK))
    GNUNET_SCHEDULER_cancel (neighbor->send_context->task);
  GNUNET_free (neighbor);
}


/**
 * Process dv requests.
 *
 * @param cls closure
 * @param server the initialized server
 * @param c configuration to use
 */
static void
run (void *cls, struct GNUNET_SERVER_Handle *server,
     const struct GNUNET_CONFIGURATION_Handle *c)
{
  unsigned long long max_hosts;

  cfg = c;

  /* FIXME: Read from config, or calculate, or something other than this! */
  max_hosts = DEFAULT_DIRECT_CONNECTIONS;
  max_table_size = DEFAULT_DV_SIZE;
  fisheye_depth = DEFAULT_FISHEYE_DEPTH;

  if (GNUNET_CONFIGURATION_have_value (cfg, "dv", "max_direct_connections"))
    GNUNET_assert (GNUNET_OK ==
                   GNUNET_CONFIGURATION_get_value_number (cfg, "dv",
                                                          "max_direct_connections",
                                                          &max_hosts));

  if (GNUNET_CONFIGURATION_have_value (cfg, "dv", "max_total_connections"))
    GNUNET_assert (GNUNET_OK ==
                   GNUNET_CONFIGURATION_get_value_number (cfg, "dv",
                                                          "max_total_connections",
                                                          &max_table_size));


  if (GNUNET_CONFIGURATION_have_value (cfg, "dv", "fisheye_depth"))
    GNUNET_assert (GNUNET_OK ==
                   GNUNET_CONFIGURATION_get_value_number (cfg, "dv",
                                                          "fisheye_depth",
                                                          &fisheye_depth));

  neighbor_min_heap =
      GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
  neighbor_max_heap =
      GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MAX);

  direct_neighbors = GNUNET_CONTAINER_multihashmap_create (max_hosts, GNUNET_NO);
  extended_neighbors =
    GNUNET_CONTAINER_multihashmap_create (max_table_size * 3, GNUNET_NO);

  GNUNET_SERVER_add_handlers (server, plugin_handlers);
  coreAPI = GNUNET_CORE_connect (cfg, NULL,  /* FIXME: anything we want to pass around? */
                                 &core_init, &handle_core_connect,
                                 &handle_core_disconnect, NULL, GNUNET_NO, NULL,
                                 GNUNET_NO, core_handlers);

  if (coreAPI == NULL)
    return;

  coreMST = GNUNET_SERVER_mst_create (&tokenized_message_handler, NULL);

  peerinfo_handle = GNUNET_PEERINFO_connect (cfg);

  if (peerinfo_handle == NULL)
  {
    GNUNET_CORE_disconnect (coreAPI);
    return;
  }

  /* Scheduled the task to clean up when shutdown is called */
  cleanup_task =
      GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
                                    &shutdown_task, NULL);
}


/**
 * The main function for the dv service.
 *
 * @param argc number of arguments from the command line
 * @param argv command line arguments
 * @return 0 ok, 1 on error
 */
int
main (int argc, char *const *argv)
{
  return (GNUNET_OK ==
          GNUNET_SERVICE_run (argc, argv, "dv", GNUNET_SERVICE_OPTION_NONE,
                              &run, NULL)) ? 0 : 1;
}