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

/*
     This file is part of GNUnet.
     (C) 2009, 2010 Christian Grothoff (and other contributing authors)

     GNUnet is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     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 dht/gnunet-service-dht.c
 * @brief main DHT service shell, building block for DHT implementations
 * @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_datacache_lib.h"
#include "gnunet_transport_service.h"
#include "gnunet_hello_lib.h"
#include "gnunet_dht_service.h"
#include "dhtlog.h"
#include "dht.h"

/**
 * How many buckets will we allow total.
 */
#define MAX_BUCKETS sizeof (GNUNET_HashCode) * 8

/**
 * What is the maximum number of peers in a given bucket.
 */
#define DEFAULT_BUCKET_SIZE 8

/**
 * Minimum number of peers we need for "good" routing,
 * any less than this and we will allow messages to
 * travel much further through the network!
 */
#define MINIMUM_PEER_THRESHOLD 20

#define DHT_DEFAULT_FIND_PEER_REPLICATION 20

#define DHT_DEFAULT_FIND_PEER_OPTIONS GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE

#define DHT_DEFAULT_FIND_PEER_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 5)

/**
 * Real maximum number of hops, at which point we refuse
 * to forward the message.
 */
#define MAX_HOPS 20

/**
 * Linked list of messages to send to clients.
 */
struct P2PPendingMessage
{
  /**
   * Pointer to next item in the list
   */
  struct P2PPendingMessage *next;

  /**
   * Pointer to previous item in the list
   */
  struct P2PPendingMessage *prev;

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

  /**
   * 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);

};

/**
 * Per-peer information.
 */
struct PeerInfo
{
  /**
   * Next peer entry (DLL)
   */
  struct PeerInfo *next;

  /**
   *  Prev peer entry (DLL)
   */
  struct PeerInfo *prev;

  /**
   * Head of pending messages to be sent to this peer.
   */
  struct P2PPendingMessage *head;

  /**
   * Tail of pending messages to be sent to this peer.
   */
  struct P2PPendingMessage *tail;

  /**
   * Core handle for sending messages to this peer.
   */
  struct GNUNET_CORE_TransmitHandle *th;

  /**
   * Task for scheduling message sends.
   */
  GNUNET_SCHEDULER_TaskIdentifier send_task;

  /**
   * What is the average latency for replies received?
   */
  struct GNUNET_TIME_Relative latency;

  /**
   * Number of responses received
   */
  unsigned long long response_count;

  /**
   * Number of requests sent
   */
  unsigned long long request_count;

  /**
   * What is the identity of the peer?
   */
  struct GNUNET_PeerIdentity id;

  /**
   * Transport level distance to peer.
   */
  unsigned int distance;

};

/**
 * Peers are grouped into buckets.
 */
struct PeerBucket
{
  /**
   * Head of DLL
   */
  struct PeerInfo *head;

  /**
   * Tail of DLL
   */
  struct PeerInfo *tail;

  /**
   * Number of peers in the bucket.
   */
  unsigned int peers_size;
};

/**
 * 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;

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

};

/**
 * Struct containing information about a client,
 * handle to connect to it, and any pending messages
 * that need to be sent to it.
 */
struct ClientList
{
  /**
   * Linked list of active clients
   */
  struct ClientList *next;

  /**
   * The handle to this client
   */
  struct GNUNET_SERVER_Client *client_handle;

  /**
   * Handle to the current transmission request, NULL
   * if none pending.
   */
  struct GNUNET_CONNECTION_TransmitHandle *transmit_handle;

  /**
   * Linked list of pending messages for this client
   */
  struct PendingMessage *pending_head;

  /**
   * Tail of linked list of pending messages for this client
   */
  struct PendingMessage *pending_tail;

};


/**
 * Context containing information about a DHT message received.
 */
struct DHT_MessageContext
{
  /**
   * The client this request was received from.
   * (NULL if received from another peer)
   */
  struct ClientList *client;

  /**
   * The peer this request was received from.
   * (NULL if received from local client)
   */
  const struct GNUNET_PeerIdentity *peer;

  /**
   * The key this request was about
   */
  const GNUNET_HashCode *key;

  /**
   * The unique identifier of this request
   */
  uint64_t unique_id;

  /**
   * Desired replication level
   */
  uint32_t replication;

  /**
   * Network size estimate, either ours or the sum of
   * those routed to thus far. =~ Log of number of peers
   * chosen from for this request.
   */
  uint32_t network_size;

  /**
   * Any message options for this request
   */
  uint32_t msg_options;

  /**
   * How many hops has the message already traversed?
   */
  uint32_t hop_count;

  /**
   * Bloomfilter for this routing request.
   */
  struct GNUNET_CONTAINER_BloomFilter *bloom;

  /**
   * Did we forward this message? (may need to remember it!)
   */
  int forwarded;

  /**
   * Are we the closest known peer to this key (out of our neighbors?)
   */
  int closest;
};

/**
 * Record used for remembering what peers are waiting for what
 * responses (based on search key).
 */
struct DHTRouteSource
{

  /**
   * This is a DLL.
   */
  struct DHTRouteSource *next;

  /**
   * This is a DLL.
   */
  struct DHTRouteSource *prev;

  /**
   * Source of the request.  Replies should be forwarded to
   * this peer.
   */
  struct GNUNET_PeerIdentity source;

  /**
   * If this was a local request, remember the client; otherwise NULL.
   */
  struct ClientList *client;

  /**
   * Pointer to this nodes heap location (for removal)
   */
  struct GNUNET_CONTAINER_HeapNode *hnode;

  /**
   * Back pointer to the record storing this information.
   */
  struct DHTQueryRecord *record;

  /**
   * Task to remove this entry on timeout.
   */
  GNUNET_SCHEDULER_TaskIdentifier delete_task;
};

/**
 * Entry in the DHT routing table.
 */
struct DHTQueryRecord
{
  /**
   * Head of DLL for result forwarding.
   */
  struct DHTRouteSource *head;

  /**
   * Tail of DLL for result forwarding.
   */
  struct DHTRouteSource *tail;

  /**
   * Key that the record concerns.
   */
  GNUNET_HashCode key;

  /**
   * GET message of this record (what we already forwarded?).
   */
  //DV_DHT_MESSAGE get; Try to get away with not saving this.

  /**
   * Bloomfilter of the peers we've replied to so far
   */
  //struct GNUNET_BloomFilter *bloom_results; Don't think we need this, just remove from DLL on response.

};

/**
 * DHT Routing results structure
 */
struct DHTResults
{
  /*
   * Min heap for removal upon reaching limit
   */
  struct GNUNET_CONTAINER_Heap *minHeap;

  /*
   * Hashmap for fast key based lookup
   */
  struct GNUNET_CONTAINER_MultiHashMap *hashmap;

};

/**
 * Routing option to end routing when closest peer found.
 */
static int stop_on_closest;

/**
 * Routing option to end routing when data is found.
 */
static int stop_on_found;

/**
 * Container of active queries we should remember
 */
static struct DHTResults forward_list;

/**
 * Handle to the datacache service (for inserting/retrieving data)
 */
static struct GNUNET_DATACACHE_Handle *datacache;

/**
 * The main scheduler to use for the DHT service
 */
static struct GNUNET_SCHEDULER_Handle *sched;

/**
 * The configuration the DHT service is running with
 */
static const struct GNUNET_CONFIGURATION_Handle *cfg;

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

/**
 * Handle to the transport service, for getting our hello
 */
static struct GNUNET_TRANSPORT_Handle *transport_handle;

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

/**
 * Short id of the peer, for printing
 */
static char *my_short_id;

/**
 * Our HELLO
 */
static struct GNUNET_MessageHeader *my_hello;

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

/**
 * The lowest currently used bucket.
 */
static unsigned int lowest_bucket; /* Initially equal to MAX_BUCKETS - 1 */

/**
 * The buckets (Kademlia routing table, complete with growth).
 * Array of size MAX_BUCKET_SIZE.
 */
static struct PeerBucket k_buckets[MAX_BUCKETS]; /* From 0 to MAX_BUCKETS - 1 */

/**
 * Maximum size for each bucket.
 */
static unsigned int bucket_size = DEFAULT_BUCKET_SIZE; /* Initially equal to DEFAULT_BUCKET_SIZE */

/**
 * List of active clients.
 */
static struct ClientList *client_list;

/**
 * Handle to the DHT logger.
 */
static struct GNUNET_DHTLOG_Handle *dhtlog_handle;

/*
 * Whether or not to send routing debugging information
 * to the dht logging server
 */
static unsigned int debug_routes;

/*
 * Whether or not to send FULL route information to
 * logging server
 */
static unsigned int debug_routes_extended;

/**
 * Forward declaration.
 */
static size_t send_generic_reply (void *cls, size_t size, void *buf);

/* 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 send list
 */
static void
try_core_send (void *cls,
               const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct PeerInfo *peer = cls;
  struct P2PPendingMessage *pending;
  size_t ssize;

  peer->send_task = GNUNET_SCHEDULER_NO_TASK;

  if (tc->reason == GNUNET_SCHEDULER_REASON_SHUTDOWN)
    return;

  if (peer->th != NULL)
    return; /* Message send already in progress */

  pending = peer->head;
  if (pending != NULL)
    {
      ssize = ntohs(pending->msg->size);
#if DEBUG_DHT > 1
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "`%s:%s': Calling notify_transmit_ready with size %d for peer %s\n", my_short_id,
                "DHT", ssize, GNUNET_i2s(&peer->id));
#endif
      peer->th = GNUNET_CORE_notify_transmit_ready(coreAPI, pending->importance,
                                                   pending->timeout, &peer->id,
                                                   ssize, &core_transmit_notify, peer);
    }
}

/**
 * Function called to send a request out to another peer.
 * Called both for locally initiated requests and those
 * received from other peers.
 *
 * @param cls DHT service closure argument
 * @param msg the encapsulated message
 * @param peer the peer to forward the message to
 * @param msg_ctx the context of the message (hop count, bloom, etc.)
 */
static void forward_result_message (void *cls,
                                    const struct GNUNET_MessageHeader *msg,
                                    struct PeerInfo *peer,
                                    struct DHT_MessageContext *msg_ctx)
{
  struct GNUNET_DHT_P2PRouteResultMessage *result_message;
  struct P2PPendingMessage *pending;
  size_t msize;
  size_t psize;

  msize = sizeof (struct GNUNET_DHT_P2PRouteResultMessage) + ntohs(msg->size);
  GNUNET_assert(msize <= GNUNET_SERVER_MAX_MESSAGE_SIZE);
  psize = sizeof(struct P2PPendingMessage) + msize;
  pending = GNUNET_malloc(psize);
  pending->msg = (struct GNUNET_MessageHeader *)&pending[1];
  pending->importance = DHT_SEND_PRIORITY;
  pending->timeout = GNUNET_TIME_relative_get_forever();
  result_message = (struct GNUNET_DHT_P2PRouteResultMessage *)pending->msg;
  result_message->header.size = htons(msize);
  result_message->header.type = htons(GNUNET_MESSAGE_TYPE_DHT_P2P_ROUTE_RESULT);
  result_message->options = htonl(msg_ctx->msg_options);
  result_message->hop_count = htonl(msg_ctx->hop_count + 1);
  GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_bloomfilter_get_raw_data(msg_ctx->bloom, result_message->bloomfilter, DHT_BLOOM_SIZE));
  result_message->unique_id = GNUNET_htonll(msg_ctx->unique_id);
  memcpy(&result_message->key, msg_ctx->key, sizeof(GNUNET_HashCode));
  memcpy(&result_message[1], msg, ntohs(msg->size));
#if DEBUG_DHT > 1
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "%s:%s Adding pending message size %d for peer %s\n", my_short_id, "DHT", msize, GNUNET_i2s(&peer->id));
#endif
  GNUNET_CONTAINER_DLL_insert_after(peer->head, peer->tail, peer->tail, pending);
  if (peer->send_task == GNUNET_SCHEDULER_NO_TASK)
    peer->send_task = GNUNET_SCHEDULER_add_now(sched, &try_core_send, peer);
}
/**
 * Called when core is ready to send a message we asked for
 * out to the destination.
 *
 * @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)
{
  struct PeerInfo *peer = cls;
  char *cbuf = buf;
  struct P2PPendingMessage *pending;

  size_t off;
  size_t msize;

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

  if (peer->head == NULL)
    return 0;

  peer->th = NULL;
  off = 0;
  pending = peer->head;
  msize = ntohs(pending->msg->size);
  if (msize <= size)
    {
      off = msize;
      memcpy (cbuf, pending->msg, msize);
      GNUNET_CONTAINER_DLL_remove (peer->head,
                                   peer->tail,
                                   pending);
#if DEBUG_DHT > 1
      GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "%s:%s Removing pending message size %d for peer %s\n", my_short_id, "DHT", msize, GNUNET_i2s(&peer->id));
#endif
      GNUNET_free (pending);
    }
#if SMART
  while (NULL != pending &&
          (size - off >= (msize = ntohs (pending->msg->size))))
    {
#if DEBUG_DHT_ROUTING
      GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "`%s:%s' : transmit_notify (core) called with size %d, available %d\n", my_short_id, "dht service", msize, size);
#endif
      memcpy (&cbuf[off], pending->msg, msize);
      off += msize;
      GNUNET_CONTAINER_DLL_remove (peer->head,
                                   peer->tail,
                                   pending);
      GNUNET_free (pending);
      pending = peer->head;
    }
#endif
  if ((peer->head != NULL) && (peer->send_task == GNUNET_SCHEDULER_NO_TASK))
    peer->send_task = GNUNET_SCHEDULER_add_now(sched, &try_core_send, peer);
#if DEBUG_DHT > 1
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "`%s:%s' : transmit_notify (core) called with size %d, available %d, returning %d\n", my_short_id, "dht service", msize, size, off);
#endif
  return off;
}

/**
 * Determine how many low order bits match in two
 * GNUNET_HashCodes.  i.e. - 010011 and 011111 share
 * the first two lowest order bits, and therefore the
 * return value is two (NOT XOR distance, nor how many
 * bits match absolutely!).
 *
 * @param first the first hashcode
 * @param second the hashcode to compare first to
 *
 * @return the number of bits that match
 */
static unsigned int matching_bits(const GNUNET_HashCode *first, const GNUNET_HashCode *second)
{
  unsigned int i;

  for (i = 0; i < sizeof (GNUNET_HashCode) * 8; i++)
    if (GNUNET_CRYPTO_hash_get_bit (first, i) != GNUNET_CRYPTO_hash_get_bit (second, i))
      return i;
  return sizeof (GNUNET_HashCode) * 8;
}

/**
 * Compute the distance between have and target as a 32-bit value.
 * Differences in the lower bits must count stronger than differences
 * in the higher bits.
 *
 * @return 0 if have==target, otherwise a number
 *           that is larger as the distance between
 *           the two hash codes increases
 */
static unsigned int
distance (const GNUNET_HashCode * target, const GNUNET_HashCode * have)
{
  unsigned int bucket;
  unsigned int msb;
  unsigned int lsb;
  unsigned int i;

  /* We have to represent the distance between two 2^9 (=512)-bit
     numbers as a 2^5 (=32)-bit number with "0" being used for the
     two numbers being identical; furthermore, we need to
     guarantee that a difference in the number of matching
     bits is always represented in the result.

     We use 2^32/2^9 numerical values to distinguish between
     hash codes that have the same LSB bit distance and
     use the highest 2^9 bits of the result to signify the
     number of (mis)matching LSB bits; if we have 0 matching
     and hence 512 mismatching LSB bits we return -1 (since
     512 itself cannot be represented with 9 bits) */

  /* first, calculate the most significant 9 bits of our
     result, aka the number of LSBs */
  bucket = matching_bits (target, have);
  /* bucket is now a value between 0 and 512 */
  if (bucket == 512)
    return 0;                   /* perfect match */
  if (bucket == 0)
    return (unsigned int) -1;   /* LSB differs; use max (if we did the bit-shifting
                                   below, we'd end up with max+1 (overflow)) */

  /* calculate the most significant bits of the final result */
  msb = (512 - bucket) << (32 - 9);
  /* calculate the 32-9 least significant bits of the final result by
     looking at the differences in the 32-9 bits following the
     mismatching bit at 'bucket' */
  lsb = 0;
  for (i = bucket + 1;
       (i < sizeof (GNUNET_HashCode) * 8) && (i < bucket + 1 + 32 - 9); i++)
    {
      if (GNUNET_CRYPTO_hash_get_bit (target, i) != GNUNET_CRYPTO_hash_get_bit (have, i))
        lsb |= (1 << (bucket + 32 - 9 - i));    /* first bit set will be 10,
                                                   last bit set will be 31 -- if
                                                   i does not reach 512 first... */
    }
  return msb | lsb;
}

/**
 * Return a number that is larger the closer the
 * "have" GNUNET_hash code is to the "target".
 *
 * @return inverse distance metric, non-zero.
 *         Must fudge the value if NO bits match.
 */
static unsigned int
inverse_distance (const GNUNET_HashCode * target,
                  const GNUNET_HashCode * have)
{
  if (matching_bits(target, have) == 0)
    return 1; /* Never return 0! */
  return ((unsigned int) -1) - distance (target, have);
}

/**
 * Find the optimal bucket for this key, regardless
 * of the current number of buckets in use.
 *
 * @param hc the hashcode to compare our identity to
 *
 * @return the proper bucket index, or GNUNET_SYSERR
 *         on error (same hashcode)
 */
static int find_bucket(const GNUNET_HashCode *hc)
{
  unsigned int bits;

  bits = matching_bits(&my_identity.hashPubKey, hc);
  if (bits == MAX_BUCKETS)
    return GNUNET_SYSERR;
  return MAX_BUCKETS - bits - 1;
}

/**
 * Find which k-bucket this peer should go into,
 * taking into account the size of the k-bucket
 * array.  This means that if more bits match than
 * there are currently buckets, lowest_bucket will
 * be returned.
 *
 * @param hc GNUNET_HashCode we are finding the bucket for.
 *
 * @return the proper bucket index for this key,
 *         or GNUNET_SYSERR on error (same hashcode)
 */
static int find_current_bucket(const GNUNET_HashCode *hc)
{
  int actual_bucket;
  actual_bucket = find_bucket(hc);

  if (actual_bucket == GNUNET_SYSERR) /* hc and our peer identity match! */
    return GNUNET_SYSERR;
  else if (actual_bucket < lowest_bucket) /* actual_bucket not yet used */
    return lowest_bucket;
  else
    return actual_bucket;
}

/**
 * Find a routing table entry from a peer identity
 *
 * @param peer the peer identity to look up
 *
 * @return the routing table entry, or NULL if not found
 */
static struct PeerInfo *
find_peer_by_id(const struct GNUNET_PeerIdentity *peer)
{
  int bucket;
  struct PeerInfo *pos;
  bucket = find_current_bucket(&peer->hashPubKey);

  if (bucket == GNUNET_SYSERR)
    return NULL;

  pos = k_buckets[bucket].head;
  while (pos != NULL)
    {
      if (0 == memcmp(&pos->id, peer, sizeof(struct GNUNET_PeerIdentity)))
        return pos;
      pos = pos->next;
    }
  return NULL; /* No such peer. */
}

/**
 * Really add a peer to a bucket (only do assertions
 * on size, etc.)
 *
 * @param peer GNUNET_PeerIdentity of the peer to add
 * @param bucket the already figured out bucket to add
 *        the peer to
 * @param latency the core reported latency of this peer
 * @param distance the transport level distance to this peer
 */
static void add_peer(const struct GNUNET_PeerIdentity *peer,
                     unsigned int bucket,
                     struct GNUNET_TIME_Relative latency,
                     unsigned int distance)
{
  struct PeerInfo *new_peer;
  GNUNET_assert(bucket < MAX_BUCKETS);
  GNUNET_assert(peer != NULL);
  new_peer = GNUNET_malloc(sizeof(struct PeerInfo));
  new_peer->latency = latency;
  new_peer->distance = distance;
  memcpy(&new_peer->id, peer, sizeof(struct GNUNET_PeerIdentity));

  GNUNET_CONTAINER_DLL_insert_after(k_buckets[bucket].head,
                                    k_buckets[bucket].tail,
                                    k_buckets[bucket].tail,
                                    new_peer);
  k_buckets[bucket].peers_size++;
}

/**
 * Given a peer and its corresponding bucket,
 * remove it from that bucket.  Does not free
 * the PeerInfo struct, nor cancel messages
 * or free messages waiting to be sent to this
 * peer!
 *
 * @param peer the peer to remove
 * @param bucket the bucket the peer belongs to
 */
static void remove_peer (struct PeerInfo *peer,
                         unsigned int bucket)
{
  GNUNET_assert(k_buckets[bucket].peers_size > 0);
  GNUNET_CONTAINER_DLL_remove(k_buckets[bucket].head,
                              k_buckets[bucket].tail,
                              peer);
  k_buckets[bucket].peers_size--;
}

/**
 * Removes peer from a bucket, then frees associated
 * resources and frees peer.
 *
 * @param peer peer to be removed and freed
 * @param bucket which bucket this peer belongs to
 */
static void delete_peer (struct PeerInfo *peer,
                         unsigned int bucket)
{
  struct P2PPendingMessage *pos;
  struct P2PPendingMessage *next;
  remove_peer(peer, bucket); /* First remove the peer from its bucket */

  if (peer->send_task != GNUNET_SCHEDULER_NO_TASK)
    GNUNET_SCHEDULER_cancel(sched, peer->send_task);
  if (peer->th != NULL)
    GNUNET_CORE_notify_transmit_ready_cancel(peer->th);

  pos = peer->head;
  while (pos != NULL) /* Remove any pending messages for this peer */
    {
      next = pos->next;
      GNUNET_free(pos);
      pos = next;
    }
  GNUNET_free(peer);
}

/**
 * The current lowest bucket is full, so change the lowest
 * bucket to the next lower down, and move any appropriate
 * entries in the current lowest bucket to the new bucket.
 */
static void enable_next_bucket()
{
  unsigned int new_bucket;
  unsigned int to_remove;
  int i;
  struct PeerInfo *to_remove_list[bucket_size]; /* We either use CPU by making a list, or memory with array.  Use memory. */
  struct PeerInfo *pos;
  GNUNET_assert(lowest_bucket > 0);

  pos = k_buckets[lowest_bucket].head;
  memset(to_remove_list, 0, sizeof(to_remove_list));
  to_remove = 0;
  /* Populate the array of peers which should be in the next lowest bucket */
  while (pos->next != NULL)
    {
      if (find_bucket(&pos->id.hashPubKey) < lowest_bucket)
        {
          to_remove_list[to_remove] = pos;
          to_remove++;
        }
      pos = pos->next;
    }
  new_bucket = lowest_bucket - 1;

  /* Remove peers from lowest bucket, insert into next lowest bucket */
  for (i = 0; i < bucket_size; i++)
    {
      if (to_remove_list[i] != NULL)
        {
          remove_peer(to_remove_list[i], lowest_bucket);
          GNUNET_CONTAINER_DLL_insert_after(k_buckets[new_bucket].head,
                                            k_buckets[new_bucket].tail,
                                            k_buckets[new_bucket].tail,
                                            to_remove_list[i]);
          k_buckets[new_bucket].peers_size++;
        }
      else
        break;
    }
  lowest_bucket = new_bucket;
}
/**
 * Attempt to add a peer to our k-buckets.
 *
 * @param peer, the peer identity of the peer being added
 *
 * @return GNUNET_YES if the peer was added,
 *         GNUNET_NO if not,
 *         GNUNET_SYSERR on err (peer is us!)
 */
static int try_add_peer(const struct GNUNET_PeerIdentity *peer,
                        unsigned int bucket,
                        struct GNUNET_TIME_Relative latency,
                        unsigned int distance)
{
  int peer_bucket;

  peer_bucket = find_current_bucket(&peer->hashPubKey);
  if (peer_bucket == GNUNET_SYSERR)
    return GNUNET_SYSERR;

  GNUNET_assert(peer_bucket >= lowest_bucket);
  if ((k_buckets[peer_bucket].peers_size) < bucket_size)
    {
      add_peer(peer, peer_bucket, latency, distance);
      return GNUNET_YES;
    }
  else if ((peer_bucket == lowest_bucket) && (lowest_bucket > 0))
    {
      enable_next_bucket();
      return try_add_peer(peer, bucket, latency, distance); /* Recurse, if proper bucket still full ping peers */
    }
  else if ((k_buckets[peer_bucket].peers_size) == bucket_size)
    {
      /* TODO: implement ping_oldest_peer */
      //ping_oldest_peer(bucket, peer, latency, distance); /* Find oldest peer, ping it.  If no response, remove and add new peer! */
      return GNUNET_NO;
    }
  GNUNET_break(0);
  return GNUNET_NO;
}


/**
 * Task run to check for messages that need to be sent to a client.
 *
 * @param client a ClientList, containing the client and any messages to be sent to it
 */
static void
process_pending_messages (struct ClientList *client)
{ 
  if (client->pending_head == NULL) 
    return;    
  if (client->transmit_handle != NULL) 
    return;
  client->transmit_handle =
    GNUNET_SERVER_notify_transmit_ready (client->client_handle,
					 ntohs (client->pending_head->msg->
						size),
					 GNUNET_TIME_UNIT_FOREVER_REL,
					 &send_generic_reply, client);
}

/**
 * Callback called as a result of issuing a GNUNET_SERVER_notify_transmit_ready
 * request.  A ClientList is passed as closure, take the head of the list
 * and copy it into buf, which has the result of sending the message to the
 * client.
 *
 * @param cls closure to this call
 * @param size maximum number of bytes available to send
 * @param buf where to copy the actual message to
 *
 * @return the number of bytes actually copied, 0 indicates failure
 */
static size_t
send_generic_reply (void *cls, size_t size, void *buf)
{
  struct ClientList *client = cls;
  char *cbuf = buf;
  struct PendingMessage *reply;
  size_t off;
  size_t msize;

  client->transmit_handle = NULL;
  if (buf == NULL)             
    {
      /* client disconnected */
      return 0;
    }
  off = 0;
  while ( (NULL != (reply = client->pending_head)) &&
	  (size >= off + (msize = ntohs (reply->msg->size))))
    {
      GNUNET_CONTAINER_DLL_remove (client->pending_head,
				   client->pending_tail,
				   reply);
      memcpy (&cbuf[off], reply->msg, msize);
      GNUNET_free (reply);
      off += msize;
    }
  process_pending_messages (client);
  return off;
}


/**
 * Add a PendingMessage to the clients list of messages to be sent
 *
 * @param client the active client to send the message to
 * @param pending_message the actual message to send
 */
static void
add_pending_message (struct ClientList *client,
                     struct PendingMessage *pending_message)
{
  GNUNET_CONTAINER_DLL_insert_after (client->pending_head,
				     client->pending_tail,
				     client->pending_tail,
				     pending_message);
  process_pending_messages (client);
}




/**
 * Called when a reply needs to be sent to a client, as
 * a result it found to a GET or FIND PEER request.
 *
 * @param client the client to send the reply to
 * @param message the encapsulated message to send
 * @param uid the unique identifier of this request
 */
static void
send_reply_to_client (struct ClientList *client,
                      const struct GNUNET_MessageHeader *message,
                      unsigned long long uid)
{
  struct GNUNET_DHT_RouteResultMessage *reply;
  struct PendingMessage *pending_message;
  uint16_t msize;
  size_t tsize;
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Sending reply to client.\n", my_short_id, "DHT");
#endif
  msize = ntohs (message->size);
  tsize = sizeof (struct GNUNET_DHT_RouteResultMessage) + msize;
  if (tsize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
    {
      GNUNET_break_op (0);
      return;
    }

  pending_message = GNUNET_malloc (sizeof (struct PendingMessage) + tsize);
  pending_message->msg = (struct GNUNET_MessageHeader *)&pending_message[1];
  reply = (struct GNUNET_DHT_RouteResultMessage *)&pending_message[1];
  reply->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE_RESULT);
  reply->header.size = htons (tsize);
  reply->unique_id = GNUNET_htonll (uid);
  memcpy (&reply[1], message, msize);

  add_pending_message (client, pending_message);
}


/**
 * Main function that handles whether or not to route a result
 * message to other peers, or to send to our local client.
 *
 * @param msg the result message to be routed
 * @return the number of peers the message was routed to,
 *         GNUNET_SYSERR on failure
 */
static int route_result_message(void *cls,
                                struct GNUNET_MessageHeader *msg,
                                struct DHT_MessageContext *message_context)
{
  struct DHTQueryRecord *record;
  struct DHTRouteSource *pos;
  struct PeerInfo *peer_info;
  struct GNUNET_MessageHeader *hello_msg;

  /**
   * If a find peer result message is received and contains a valid
   * HELLO for another peer, offer it to the transport service.
   *
   * FIXME: Check whether we need this peer (based on routing table
   * fullness) and only try to connect to it conditionally.  This should
   * reduce trying to connect to say (500) peers when the bucket size will
   * discard most of them.
   */
  if (ntohs(msg->type) == GNUNET_MESSAGE_TYPE_DHT_FIND_PEER_RESULT)
    {
      if (ntohs(msg->size) <= sizeof(struct GNUNET_MessageHeader))
        GNUNET_break_op(0);

      hello_msg = &msg[1];
      if (ntohs(hello_msg->type) != GNUNET_MESSAGE_TYPE_HELLO)
      {
        GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "%s:%s Received non-HELLO message type in find peer result message!\n", my_short_id, "DHT");
        GNUNET_break_op(0);
      }
      else
      {
        GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "%s:%s Received HELLO message for another peer, offering to transport!\n", my_short_id, "DHT");
        GNUNET_TRANSPORT_offer_hello(transport_handle, hello_msg);
      }

    }
  record = GNUNET_CONTAINER_multihashmap_get(forward_list.hashmap, message_context->key);
  if (record == NULL) /* No record of this message! */
    {
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "`%s:%s': Have no record of response key %s uid %llu\n", my_short_id,
                "DHT", GNUNET_h2s (message_context->key), message_context->unique_id);
#endif
#if DEBUG_DHT_ROUTING

      if ((debug_routes_extended) && (dhtlog_handle != NULL))
        {
          dhtlog_handle->insert_route (NULL,
                                       message_context->unique_id,
                                       DHTLOG_RESULT,
                                       message_context->hop_count,
                                       GNUNET_SYSERR,
                                       &my_identity,
                                       message_context->key,
                                       message_context->peer, NULL);
        }
#endif
      if (message_context->bloom != NULL)
        {
          GNUNET_CONTAINER_bloomfilter_free(message_context->bloom);
          message_context->bloom = NULL;
        }
      return 0;
    }

  pos = record->head;
  while (pos != NULL)
    {
      if (0 == memcmp(&pos->source, &my_identity, sizeof(struct GNUNET_PeerIdentity))) /* Local client (or DHT) initiated request! */
        {
#if DEBUG_DHT
          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                      "`%s:%s': Sending response key %s uid %llu to client\n", my_short_id,
                      "DHT", GNUNET_h2s (message_context->key), message_context->unique_id);
#endif
#if DEBUG_DHT_ROUTING
          if ((debug_routes_extended) && (dhtlog_handle != NULL))
            {
              dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_RESULT,
                                           message_context->hop_count,
                                           GNUNET_YES, &my_identity, message_context->key,
                                           message_context->peer, NULL);
            }
#endif
          send_reply_to_client(pos->client, msg, message_context->unique_id);
        }
      else /* Send to peer */
        {
          peer_info = find_peer_by_id(&pos->source);
          if (peer_info == NULL) /* Didn't find the peer in our routing table, perhaps peer disconnected! */
            {
              pos = pos->next;
              continue;
            }

          if (message_context->bloom == NULL)
            message_context->bloom = GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K);
          GNUNET_CONTAINER_bloomfilter_add (message_context->bloom, &my_identity.hashPubKey);
          if (GNUNET_NO == GNUNET_CONTAINER_bloomfilter_test (message_context->bloom, &peer_info->id.hashPubKey))
            {
#if DEBUG_DHT
              GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                          "`%s:%s': Forwarding response key %s uid %llu to peer %s\n", my_short_id,
                          "DHT", GNUNET_h2s (message_context->key), message_context->unique_id, GNUNET_i2s(&peer_info->id));
#endif
#if DEBUG_DHT_ROUTING
              if ((debug_routes_extended) && (dhtlog_handle != NULL))
                {
                  dhtlog_handle->insert_route (NULL, message_context->unique_id,
                                               DHTLOG_RESULT,
                                               message_context->hop_count,
                                               GNUNET_NO, &my_identity, message_context->key,
                                               message_context->peer, &pos->source);
                }
#endif
              forward_result_message(cls, msg, peer_info, message_context);
            }
          else
            {
#if DEBUG_DHT
              GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                          "`%s:%s': NOT Forwarding response (bloom match) key %s uid %llu to peer %s\n", my_short_id,
                          "DHT", GNUNET_h2s (message_context->key), message_context->unique_id, GNUNET_i2s(&peer_info->id));
#endif
            }
        }
      pos = pos->next;
    }
  if (message_context->bloom != NULL)
    GNUNET_CONTAINER_bloomfilter_free(message_context->bloom);
  return 0;
}

/**
 * Iterator for local get request results,
 *
 * @param cls closure for iterator, a DatacacheGetContext
 * @param exp when does this value expire?
 * @param key the key this data is stored under
 * @param size the size of the data identified by key
 * @param data the actual data
 * @param type the type of the data
 *
 * @return GNUNET_OK to continue iteration, anything else
 * to stop iteration.
 */
static int
datacache_get_iterator (void *cls,
                        struct GNUNET_TIME_Absolute exp,
                        const GNUNET_HashCode * key,
                        uint32_t size, const char *data, uint32_t type)
{
  struct DHT_MessageContext *msg_ctx = cls;
  struct DHT_MessageContext *new_msg_ctx;
  struct GNUNET_DHT_GetResultMessage *get_result;
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Received `%s' response from datacache\n", my_short_id, "DHT", "GET");
#endif
  new_msg_ctx = GNUNET_malloc(sizeof(struct DHT_MessageContext));
  memcpy(new_msg_ctx, msg_ctx, sizeof(struct DHT_MessageContext));
  get_result =
    GNUNET_malloc (sizeof (struct GNUNET_DHT_GetResultMessage) + size);
  get_result->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_GET_RESULT);
  get_result->header.size =
    htons (sizeof (struct GNUNET_DHT_GetResultMessage) + size);
  get_result->expiration = GNUNET_TIME_absolute_hton(exp);
  get_result->type = htons (type);
  memcpy (&get_result[1], data, size);
  new_msg_ctx->peer = &my_identity;
  new_msg_ctx->bloom = GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K);
  new_msg_ctx->hop_count = 0;
  route_result_message(cls, &get_result->header, new_msg_ctx);
  GNUNET_free(new_msg_ctx);
  //send_reply_to_client (datacache_get_ctx->client, &get_result->header,
  //                      datacache_get_ctx->unique_id);
  GNUNET_free (get_result);
  return GNUNET_OK;
}


/**
 * Server handler for all dht get requests, look for data,
 * if found, send response either to clients or other peers.
 *
 * @param cls closure for service
 * @param msg the actual get message
 * @param message_context struct containing pertinent information about the get request
 *
 * @return number of items found for GET request
 */
static unsigned int
handle_dht_get (void *cls, 
		const struct GNUNET_MessageHeader *msg,
                struct DHT_MessageContext *message_context)
{
  const struct GNUNET_DHT_GetMessage *get_msg;
  uint16_t get_type;
  unsigned int results;

  get_msg = (const struct GNUNET_DHT_GetMessage *) msg;
  if (ntohs (get_msg->header.size) != sizeof (struct GNUNET_DHT_GetMessage))
    {
      GNUNET_break (0);
      return 0;
    }

  get_type = ntohs (get_msg->type);
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Received `%s' request from client, message type %u, key %s, uid %llu\n", my_short_id,
              "DHT", "GET", get_type, GNUNET_h2s (message_context->key),
              message_context->unique_id);
#endif

  results = 0;
  if (datacache != NULL)
    results =
      GNUNET_DATACACHE_get (datacache, message_context->key, get_type,
                            &datacache_get_iterator, message_context);

  if (results >= 1)
    {
#if DEBUG_DHT
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "`%s:%s': Found %d results for `%s' request uid %llu\n", my_short_id, "DHT",
                  results, "GET", message_context->unique_id);
#endif
#if DEBUG_DHT_ROUTING
      if ((debug_routes) && (dhtlog_handle != NULL))
        {
          dhtlog_handle->insert_query (NULL, message_context->unique_id, DHTLOG_GET,
                                message_context->hop_count, GNUNET_YES, &my_identity,
                                message_context->key);
        }

      if ((debug_routes_extended) && (dhtlog_handle != NULL))
        {
          dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_ROUTE,
                                       message_context->hop_count, GNUNET_YES,
                                       &my_identity, message_context->key, message_context->peer,
                                       NULL);
        }
#endif
    }

  if (message_context->hop_count == 0) /* Locally initiated request */
    {
#if DEBUG_DHT_ROUTING
    if ((debug_routes) && (dhtlog_handle != NULL))
      {
        dhtlog_handle->insert_query (NULL, message_context->unique_id, DHTLOG_GET,
                                      message_context->hop_count, GNUNET_NO, &my_identity,
                                      message_context->key);
      }
#endif
    }

  return results;
}


/**
 * Server handler for initiating local dht find peer requests
 *
 * @param cls closure for service
 * @param find_msg the actual find peer message
 * @param message_context struct containing pertinent information about the request
 *
 */
static void
handle_dht_find_peer (void *cls, 
		      const struct GNUNET_MessageHeader *find_msg,
                      struct DHT_MessageContext *message_context)
{
  struct GNUNET_MessageHeader *find_peer_result;
  struct DHT_MessageContext *new_msg_ctx;
  size_t hello_size;
  size_t tsize;

#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Received `%s' request from client, key %s (msg size %d, we expected %d)\n",
              my_short_id, "DHT", "FIND PEER", GNUNET_h2s (message_context->key),
              ntohs (find_msg->size),
              sizeof (struct GNUNET_MessageHeader));
#endif
  if ((my_hello == NULL) || (message_context->closest != GNUNET_YES))
  {
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "`%s': Our HELLO is null, can't return.\n",
                "DHT");
#endif
    return;
  }
  /* Simplistic find_peer functionality, always return our hello */
  hello_size = ntohs(my_hello->size);
  tsize = hello_size + sizeof (struct GNUNET_MessageHeader);

  if (tsize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
    {
      GNUNET_break_op (0);
      return;
    }

  find_peer_result = GNUNET_malloc (tsize);
  find_peer_result->type = htons (GNUNET_MESSAGE_TYPE_DHT_FIND_PEER_RESULT);
  find_peer_result->size = htons (tsize);
  memcpy (&find_peer_result[1], my_hello, hello_size);

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s': Sending hello size %d to requesting peer.\n",
              "DHT", hello_size);

  new_msg_ctx = GNUNET_malloc(sizeof(struct DHT_MessageContext));
  memcpy(new_msg_ctx, message_context, sizeof(struct DHT_MessageContext));
  new_msg_ctx->peer = &my_identity;
  new_msg_ctx->bloom = GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K);
  new_msg_ctx->hop_count = 0;
  route_result_message(cls, find_peer_result, new_msg_ctx);
  //send_reply_to_client(message_context->client, find_peer_result, message_context->unique_id);
  GNUNET_free(find_peer_result);
}


/**
 * Server handler for initiating local dht put requests
 *
 * @param cls closure for service
 * @param msg the actual put message
 * @param message_context struct containing pertinent information about the request
 */
static void
handle_dht_put (void *cls,
		const struct GNUNET_MessageHeader *msg,
                struct DHT_MessageContext *message_context)
{
  struct GNUNET_DHT_PutMessage *put_msg;
  size_t put_type;
  size_t data_size;

  GNUNET_assert (ntohs (msg->size) >=
                 sizeof (struct GNUNET_DHT_PutMessage));
  put_msg = (struct GNUNET_DHT_PutMessage *)msg;
  put_type = ntohs (put_msg->type);
  data_size = ntohs (put_msg->header.size) - sizeof (struct GNUNET_DHT_PutMessage);
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Received `%s' request (inserting data!), message type %d, key %s, uid %llu\n",
              my_short_id, "DHT", "PUT", put_type, GNUNET_h2s (message_context->key), message_context->unique_id);
#endif
#if DEBUG_DHT_ROUTING

  if ((debug_routes) && (dhtlog_handle != NULL))
    {
      dhtlog_handle->insert_query (NULL, message_context->unique_id, DHTLOG_PUT,
                                   message_context->hop_count, GNUNET_YES, &my_identity,
                                   message_context->key);
    }
#endif

  if (datacache != NULL)
    GNUNET_DATACACHE_put (datacache, message_context->key, data_size,
                          (char *) &put_msg[1], put_type,
                          GNUNET_TIME_absolute_ntoh(put_msg->expiration));
  else
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "`%s:%s': %s request received, but have no datacache!\n",
                my_short_id, "DHT", "PUT");
}

/**
 * Estimate the diameter of the network based
 * on how many buckets are currently in use.
 * Concept here is that the diameter of the network
 * is roughly the distance a message must travel in
 * order to reach its intended destination.  Since
 * at each hop we expect to get one bit closer, and
 * we have one bit per bucket, the number of buckets
 * in use should be the largest number of hops for
 * a sucessful message. (of course, this assumes we
 * know all peers in the network!)
 *
 * @return ballpark diameter figure
 */
static unsigned int estimate_diameter()
{
  return MAX_BUCKETS - lowest_bucket;
}

/**
 * To how many peers should we (on average)
 * forward the request to obtain the desired
 * target_replication count (on average).
 *
 * Always 0, 1 or 2 (don't send, send once, split)
 */
static unsigned int
get_forward_count (unsigned int hop_count, size_t target_replication)
{
  double target_count;
  unsigned int target_value;
  unsigned int diameter;

  /* FIXME: the smaller we think the network is the more lenient we should be for
   * routing right?  The estimation below only works if we think we have reasonably
   * full routing tables, which for our RR topologies may not be the case!
   */
  diameter = estimate_diameter ();
  if ((hop_count > (diameter + 1) * 2) && (MINIMUM_PEER_THRESHOLD < estimate_diameter() * bucket_size))
    {
#if DEBUG_DHT
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "`%s:%s': Hop count too high (est %d, lowest %d), NOT Forwarding request\n", my_short_id,
                  "DHT", estimate_diameter(), lowest_bucket);
#endif
      return 0;
    }
  else if (hop_count > MAX_HOPS)
    {
#if DEBUG_DHT
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "`%s:%s': Hop count too high (greater than max)\n", my_short_id,
                  "DHT");
#endif
      return 0;
    }
  target_count = /* target_count is ALWAYS < 1 unless replication is < 1 */
    target_replication / (target_replication * (hop_count + 1) + diameter);
  target_value = 0;

#if NONSENSE
  while (target_value < target_count)
    target_value++; /* target_value is ALWAYS 1 after this "loop" */
#else
  target_value = 1;
#endif
  if ((target_count + 1 - target_value) >
      GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
                                RAND_MAX) / RAND_MAX)
    target_value++;
  return target_value;
}

/**
 * Find the closest peer in our routing table to the
 * given hashcode.
 *
 * @return The closest peer in our routing table to the
 *         key, or NULL on error.
 */
static struct PeerInfo *
find_closest_peer (const GNUNET_HashCode *hc)
{
  struct PeerInfo *pos;
  struct PeerInfo *current_closest;
  unsigned int lowest_distance;
  unsigned int temp_distance;
  int bucket;

  lowest_distance = -1;

  if (k_buckets[lowest_bucket].peers_size == 0)
    return NULL;

  for (bucket = lowest_bucket; bucket < MAX_BUCKETS; bucket++)
    {
      pos = k_buckets[bucket].head;
      while (pos != NULL)
        {
          temp_distance = distance(&pos->id.hashPubKey, hc);
          if (temp_distance <= lowest_distance)
            {
              lowest_distance = temp_distance;
              current_closest = pos;
            }
          pos = pos->next;
        }
    }
  GNUNET_assert(current_closest != NULL);
  return current_closest;
}

/*
 * Check whether my identity is closer than any known peers.
 *
 * @param target hash code to check closeness to
 *
 * Return GNUNET_YES if node location is closest, GNUNET_NO
 * otherwise.
 */
int
am_closest_peer (const GNUNET_HashCode * target)
{
  int bits;
  int other_bits;
  int bucket_num;
  struct PeerInfo *pos;
  unsigned int my_distance;

  bucket_num = find_current_bucket(target);
  if (bucket_num == GNUNET_SYSERR) /* Same key! */
    return GNUNET_YES;

  bits = matching_bits(&my_identity.hashPubKey, target);
  my_distance = distance(&my_identity.hashPubKey, target);

  pos = k_buckets[bucket_num].head;
  while (pos != NULL)
    {
      other_bits = matching_bits(&pos->id.hashPubKey, target);
      if (other_bits > bits)
        return GNUNET_NO;
      else if (other_bits == bits) /* We match the same number of bits, do distance comparison */
        {
          if (distance(&pos->id.hashPubKey, target) < my_distance)
            return GNUNET_NO;
        }
      pos = pos->next;
    }

#if DEBUG_TABLE
  GNUNET_GE_LOG (coreAPI->ectx,
                 GNUNET_GE_WARNING | GNUNET_GE_ADMIN | GNUNET_GE_USER |
                 GNUNET_GE_BULK, "closest peer\n");
  printPeerBits (&closest);
  GNUNET_GE_LOG (coreAPI->ectx,
                 GNUNET_GE_WARNING | GNUNET_GE_ADMIN | GNUNET_GE_USER |
                 GNUNET_GE_BULK, "me\n");
  printPeerBits (coreAPI->my_identity);
  GNUNET_GE_LOG (coreAPI->ectx,
                 GNUNET_GE_WARNING | GNUNET_GE_ADMIN | GNUNET_GE_USER |
                 GNUNET_GE_BULK, "key\n");
  printKeyBits (target);
  GNUNET_GE_LOG (coreAPI->ectx,
                 GNUNET_GE_WARNING | GNUNET_GE_ADMIN | GNUNET_GE_USER |
                 GNUNET_GE_BULK,
                 "closest peer inverse distance is %u, mine is %u\n",
                 inverse_distance (target, &closest.hashPubKey),
                 inverse_distance (target,
                                   &coreAPI->my_identity->hashPubKey));
#endif

  /* No peers closer, we are the closest! */
  return GNUNET_YES;

}


/**
 * Select a peer from the routing table that would be a good routing
 * destination for sending a message for "target".  The resulting peer
 * must not be in the set of blocked peers.<p>
 *
 * Note that we should not ALWAYS select the closest peer to the
 * target, peers further away from the target should be chosen with
 * exponentially declining probability.
 *
 * @param target the key we are selecting a peer to route to
 * @param bloom a bloomfilter containing entries this request has seen already
 *
 * @return Peer to route to, or NULL on error
 */
static struct PeerInfo *
select_peer (const GNUNET_HashCode * target,
             struct GNUNET_CONTAINER_BloomFilter *bloom)
{
  unsigned int distance;
  unsigned int bc;
  struct PeerInfo *pos;
#if USE_KADEMLIA
  const struct PeerInfo *chosen;
  unsigned long long largest_distance;
#else
  unsigned long long total_distance;
  unsigned long long selected;
#endif

#if USE_KADEMLIA
  largest_distance = 0;
  chosen = NULL;
  for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++)
    {
      pos = k_buckets[bc].head;
      while (pos != NULL)
        {
          if (GNUNET_NO == GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey))
            {
              distance = inverse_distance (target, &pos->id.hashPubKey);
              if (distance > largest_distance)
                {
                  chosen = pos;
                  largest_distance = distance;
                }
            }
          pos = pos->next;
        }
    }

  if ((largest_distance > 0) && (chosen != NULL))
    {
      GNUNET_CONTAINER_bloomfilter_add(bloom, &chosen->id.hashPubKey);
      return chosen;
    }
  else
    {
      return NULL;
    }
#else
  /* GNUnet-style */
  total_distance = 0;
  for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++)
    {
      pos = k_buckets[bc].head;
      while (pos != NULL)
        {
          if (GNUNET_NO == GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey))
            total_distance += (unsigned long long)inverse_distance (target, &pos->id.hashPubKey);
#if DEBUG_DHT > 1
          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                      "`%s:%s': Total distance is %llu, distance from %s to %s is %u\n",
                      my_short_id, "DHT", total_distance, GNUNET_i2s(&pos->id), GNUNET_h2s(target) , inverse_distance(target, &pos->id.hashPubKey));
#endif
          pos = pos->next;
        }
    }
  if (total_distance == 0)
    {
      return NULL;
    }

  selected = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, total_distance);
  for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++)
    {
      pos = k_buckets[bc].head;
      while (pos != NULL)
        {
          if (GNUNET_NO == GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey))
            {
              distance = inverse_distance (target, &pos->id.hashPubKey);
              if (distance > selected)
                return pos;
              selected -= distance;
            }
          else
            {
#if DEBUG_DHT
              GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                          "`%s:%s': peer %s matches bloomfilter.\n",
                          my_short_id, "DHT", GNUNET_i2s(&pos->id));
#endif
            }
          pos = pos->next;
        }
    }
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "`%s:%s': peer %s matches bloomfilter.\n",
                my_short_id, "DHT", GNUNET_i2s(&pos->id));
#endif
  return NULL;
#endif
}

/**
 * Function called to send a request out to another peer.
 * Called both for locally initiated requests and those
 * received from other peers.
 *
 * @param cls DHT service closure argument
 * @param msg the encapsulated message
 * @param peer the peer to forward the message to
 * @param msg_ctx the context of the message (hop count, bloom, etc.)
 */
static void forward_message (void *cls,
                             const struct GNUNET_MessageHeader *msg,
                             struct PeerInfo *peer,
                             struct DHT_MessageContext *msg_ctx)
{
  struct GNUNET_DHT_P2PRouteMessage *route_message;
  struct P2PPendingMessage *pending;
  size_t msize;
  size_t psize;

  msize = sizeof (struct GNUNET_DHT_P2PRouteMessage) + ntohs(msg->size);
  GNUNET_assert(msize <= GNUNET_SERVER_MAX_MESSAGE_SIZE);
  psize = sizeof(struct P2PPendingMessage) + msize;
  pending = GNUNET_malloc(psize);
  pending->msg = (struct GNUNET_MessageHeader *)&pending[1];
  pending->importance = DHT_SEND_PRIORITY;
  pending->timeout = GNUNET_TIME_relative_get_forever();
  route_message = (struct GNUNET_DHT_P2PRouteMessage *)pending->msg;
  route_message->header.size = htons(msize);
  route_message->header.type = htons(GNUNET_MESSAGE_TYPE_DHT_P2P_ROUTE);
  route_message->options = htonl(msg_ctx->msg_options);
  route_message->hop_count = htonl(msg_ctx->hop_count + 1);
  route_message->network_size = htonl(msg_ctx->network_size);
  route_message->desired_replication_level = htonl(msg_ctx->replication);
  route_message->unique_id = GNUNET_htonll(msg_ctx->unique_id);
  GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_bloomfilter_get_raw_data(msg_ctx->bloom, route_message->bloomfilter, DHT_BLOOM_SIZE));
  memcpy(&route_message->key, msg_ctx->key, sizeof(GNUNET_HashCode));
  memcpy(&route_message[1], msg, ntohs(msg->size));
#if DEBUG_DHT > 1
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "%s:%s Adding pending message size %d for peer %s\n", my_short_id, "DHT", msize, GNUNET_i2s(&peer->id));
#endif
  GNUNET_CONTAINER_DLL_insert_after(peer->head, peer->tail, peer->tail, pending);
  if (peer->send_task == GNUNET_SCHEDULER_NO_TASK)
    peer->send_task = GNUNET_SCHEDULER_add_now(sched, &try_core_send, peer);
}

/**
 * Task used to remove forwarding entries, either
 * after timeout, when full, or on shutdown.
 *
 * @param cls the entry to remove
 * @param tc context, reason, etc.
 */
static void
remove_forward_entry (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct DHTRouteSource *source_info = cls;
  struct DHTQueryRecord *record;
  source_info = GNUNET_CONTAINER_heap_remove_node(forward_list.minHeap, source_info->hnode);
  record = source_info->record;
  GNUNET_CONTAINER_DLL_remove(record->head, record->tail, source_info);

  if (record->head == NULL) /* No more entries in DLL */
    {
      GNUNET_assert(GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove(forward_list.hashmap, &record->key, record));
      GNUNET_free(record);
    }
  GNUNET_free(source_info);
}

/**
 * Remember this routing request so that if a reply is
 * received we can either forward it to the correct peer
 * or return the result locally.
 *
 * @param cls DHT service closure
 * @param msg_ctx Context of the route request
 *
 * @return GNUNET_YES if this response was cached, GNUNET_NO if not
 */
static int cache_response(void *cls, struct DHT_MessageContext *msg_ctx)
{
  struct DHTQueryRecord *record;
  struct DHTRouteSource *source_info;
  struct DHTRouteSource *pos;
  struct GNUNET_TIME_Absolute now;
  unsigned int current_size;

  current_size = GNUNET_CONTAINER_multihashmap_size(forward_list.hashmap);
  while (current_size >= MAX_OUTSTANDING_FORWARDS)
    {
      source_info = GNUNET_CONTAINER_heap_remove_root(forward_list.minHeap);
      record = source_info->record;
      GNUNET_CONTAINER_DLL_remove(record->head, record->tail, source_info);
      if (record->head == NULL) /* No more entries in DLL */
        {
          GNUNET_assert(GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove(forward_list.hashmap, &record->key, record));
          GNUNET_free(record);
        }
      GNUNET_SCHEDULER_cancel(sched, source_info->delete_task);
      GNUNET_free(source_info);
      current_size = GNUNET_CONTAINER_multihashmap_size(forward_list.hashmap);
    }
  now = GNUNET_TIME_absolute_get();
  record = GNUNET_CONTAINER_multihashmap_get(forward_list.hashmap, msg_ctx->key);
  if (record != NULL) /* Already know this request! */
    {
      pos = record->head;
      while (pos != NULL)
        {
          if (0 == memcmp(msg_ctx->peer, &pos->source, sizeof(struct GNUNET_PeerIdentity)))
            break; /* Already have this peer in reply list! */
          pos = pos->next;
        }
      if ((pos != NULL) && (pos->client == msg_ctx->client)) /* Seen this already */
        {
          GNUNET_CONTAINER_heap_update_cost(forward_list.minHeap, pos->hnode, now.value);
          return GNUNET_NO;
        }
    }
  else
    {
      record = GNUNET_malloc(sizeof (struct DHTQueryRecord));
      GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_multihashmap_put(forward_list.hashmap, msg_ctx->key, record, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
      memcpy(&record->key, msg_ctx->key, sizeof(GNUNET_HashCode));
    }

  source_info = GNUNET_malloc(sizeof(struct DHTRouteSource));
  source_info->record = record;
  source_info->delete_task = GNUNET_SCHEDULER_add_delayed(sched, DHT_FORWARD_TIMEOUT, &remove_forward_entry, source_info);
  memcpy(&source_info->source, msg_ctx->peer, sizeof(struct GNUNET_PeerIdentity));
  GNUNET_CONTAINER_DLL_insert_after(record->head, record->tail, record->tail, source_info);
  if (msg_ctx->client != NULL) /* For local request, set timeout so high it effectively never gets pushed out */
    {
      source_info->client = msg_ctx->client;
      now = GNUNET_TIME_absolute_get_forever();
    }
  source_info->hnode = GNUNET_CONTAINER_heap_insert(forward_list.minHeap, source_info, now.value);
#if DEBUG_DHT > 1
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "`%s:%s': Created new forward source info for %s uid %llu\n", my_short_id,
                  "DHT", GNUNET_h2s (msg_ctx->key), msg_ctx->unique_id);
#endif
  return GNUNET_YES;
}


/**
 * Main function that handles whether or not to route a message to other
 * peers.
 *
 * @param msg the message to be routed
 *
 * @return the number of peers the message was routed to,
 *         GNUNET_SYSERR on failure
 */
static int route_message(void *cls,
                         const struct GNUNET_MessageHeader *msg,
                         struct DHT_MessageContext *message_context)
{
  int i;
  struct PeerInfo *selected;
  struct PeerInfo *nearest;
  unsigned int forward_count;
#if DEBUG_DHT
  char *nearest_buf;
#endif
#if DEBUG_DHT_ROUTING
  int ret;
#endif

  message_context->closest = am_closest_peer(message_context->key);
  forward_count = get_forward_count(message_context->hop_count, message_context->replication);
  nearest = find_closest_peer(message_context->key);

  if (message_context->bloom == NULL)
    message_context->bloom = GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K);
  GNUNET_CONTAINER_bloomfilter_add (message_context->bloom, &my_identity.hashPubKey);

  if ((stop_on_closest == GNUNET_YES) && (message_context->closest == GNUNET_YES) && (ntohs(msg->type) == GNUNET_MESSAGE_TYPE_DHT_PUT))
    forward_count = 0;

#if DEBUG_DHT_ROUTING
  if (forward_count == 0)
    ret = GNUNET_SYSERR;
  else
    ret = GNUNET_NO;

  if ((debug_routes_extended) && (dhtlog_handle != NULL))
    {
      dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_ROUTE,
                                   message_context->hop_count, ret,
                                   &my_identity, message_context->key, message_context->peer,
                                   NULL);
    }
#endif

  switch (ntohs(msg->type))
    {
    case GNUNET_MESSAGE_TYPE_DHT_GET: /* Add to hashmap of requests seen, search for data (always) */
      cache_response (cls, message_context);
      if ((handle_dht_get (cls, msg, message_context) > 0) && (stop_on_found == GNUNET_YES))
        forward_count = 0;
      break;
    case GNUNET_MESSAGE_TYPE_DHT_PUT: /* Check if closest, if so insert data. FIXME: thresholding?*/
      if (message_context->closest == GNUNET_YES)
        {
#if DEBUG_DHT_ROUTING
          if ((debug_routes_extended) && (dhtlog_handle != NULL))
            {
              dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_ROUTE,
                                           message_context->hop_count, GNUNET_YES,
                                           &my_identity, message_context->key, message_context->peer,
                                           NULL);
            }
#endif
          handle_dht_put (cls, msg, message_context);
        }
#if DEBUG_DHT_ROUTING
        if (message_context->hop_count == 0) /* Locally initiated request */
          {
            if ((debug_routes) && (dhtlog_handle != NULL))
              {
                dhtlog_handle->insert_query (NULL, message_context->unique_id, DHTLOG_PUT,
                                             message_context->hop_count, GNUNET_NO, &my_identity,
                                             message_context->key);
              }
          }
#endif
      break;
    case GNUNET_MESSAGE_TYPE_DHT_FIND_PEER: /* Check if closest and not started by us, check options, add to requests seen */
      if (0 != memcmp(message_context->peer, &my_identity, sizeof(struct GNUNET_PeerIdentity)))
      {
        cache_response (cls, message_context);
        if ((message_context->closest == GNUNET_YES) || (message_context->msg_options == GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE))
          handle_dht_find_peer (cls, msg, message_context);
      }
      break;
    default:
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                  "`%s': Message type (%d) not handled\n", "DHT", ntohs(msg->type));
    }

  for (i = 0; i < forward_count; i++)
    {
      selected = select_peer(message_context->key, message_context->bloom);

      if (selected != NULL)
        {
          GNUNET_CONTAINER_bloomfilter_add(message_context->bloom, &selected->id.hashPubKey);
#if DEBUG_DHT_ROUTING > 1
          nearest_buf = GNUNET_strdup(GNUNET_i2s(&nearest->id));
          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                      "`%s:%s': Forwarding request key %s uid %llu to peer %s (closest %s, bits %d, distance %u)\n", my_short_id,
                      "DHT", GNUNET_h2s (message_context->key), message_context->unique_id, GNUNET_i2s(&selected->id), nearest_buf, matching_bits(&nearest->id.hashPubKey, message_context->key), distance(&nearest->id.hashPubKey, message_context->key));
          GNUNET_free(nearest_buf);
#endif
          /* FIXME: statistics */
          if ((debug_routes_extended) && (dhtlog_handle != NULL))
            {
              dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_ROUTE,
                                           message_context->hop_count, GNUNET_NO,
                                           &my_identity, message_context->key, message_context->peer,
                                           &selected->id);
            }
          forward_message(cls, msg, selected, message_context);
        }
      else
        {
#if DEBUG_DHT
          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                      "`%s:%s': No peers selected for forwarding.\n", my_short_id,
                      "DHT");
#endif
        }
    }
#if DEBUG_DHT_ROUTING > 1
  if (forward_count == 0)
    {
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "`%s:%s': NOT Forwarding request key %s uid %llu to any peers\n", my_short_id,
                  "DHT", GNUNET_h2s (message_context->key), message_context->unique_id);
    }
#endif

  if (message_context->bloom != NULL)
    GNUNET_CONTAINER_bloomfilter_free(message_context->bloom);

  return forward_count;
}

/**
 * Find a client if it exists, add it otherwise.
 *
 * @param client the server handle to the client
 *
 * @return the client if found, a new client otherwise
 */
static struct ClientList *
find_active_client (struct GNUNET_SERVER_Client *client)
{
  struct ClientList *pos = client_list;
  struct ClientList *ret;

  while (pos != NULL)
    {
      if (pos->client_handle == client)
        return pos;
      pos = pos->next;
    }

  ret = GNUNET_malloc (sizeof (struct ClientList));
  ret->client_handle = client;
  ret->next = client_list;
  client_list = ret;
  return ret;
}

/**
 * Task to send a find peer message for our own peer identifier
 * so that we can find the closest peers in the network to ourselves
 * and attempt to connect to them.
 *
 * @param cls closure for this task
 * @param tc the context under which the task is running
 */
static void
send_find_peer_message (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct GNUNET_MessageHeader *find_peer_msg;
  struct DHT_MessageContext message_context;
  int ret;

  if (tc->reason == GNUNET_SCHEDULER_REASON_SHUTDOWN)
    return;

  find_peer_msg = GNUNET_malloc(sizeof(struct GNUNET_MessageHeader));
  find_peer_msg->size = htons(sizeof(struct GNUNET_MessageHeader));
  find_peer_msg->type = htons(GNUNET_MESSAGE_TYPE_DHT_FIND_PEER);
  memset(&message_context, 0, sizeof(struct DHT_MessageContext));
  message_context.key = &my_identity.hashPubKey;
  message_context.unique_id = GNUNET_ntohll (GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_WEAK, (uint64_t)-1));
  message_context.replication = ntohl (DHT_DEFAULT_FIND_PEER_REPLICATION);
  message_context.msg_options = ntohl (DHT_DEFAULT_FIND_PEER_OPTIONS);
  message_context.network_size = estimate_diameter();
  message_context.peer = &my_identity;

  ret = route_message(NULL, find_peer_msg, &message_context);

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Sent `%s' request to %d peers\n", my_short_id, "DHT",
              "FIND PEER", ret);
  GNUNET_SCHEDULER_add_delayed (sched,
                                DHT_DEFAULT_FIND_PEER_INTERVAL,
                                &send_find_peer_message, NULL);
}

/**
 * Handler for any generic DHT messages, calls the appropriate handler
 * depending on message type, sends confirmation if responses aren't otherwise
 * expected.
 *
 * @param cls closure for the service
 * @param client the client we received this message from
 * @param message the actual message received
 */
static void
handle_dht_local_route_request (void *cls, struct GNUNET_SERVER_Client *client,
                                const struct GNUNET_MessageHeader *message)
{
  const struct GNUNET_DHT_RouteMessage *dht_msg = (const struct GNUNET_DHT_RouteMessage *) message;
  const struct GNUNET_MessageHeader *enc_msg;
  struct DHT_MessageContext message_context;
  size_t enc_type;

  enc_msg = (const struct GNUNET_MessageHeader *) &dht_msg[1];
  enc_type = ntohs (enc_msg->type);

#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Received `%s' request from client, message type %d, key %s, uid %llu\n",
              my_short_id, "DHT", "GENERIC", enc_type, GNUNET_h2s (&dht_msg->key),
              GNUNET_ntohll (dht_msg->unique_id));
#endif
#if DEBUG_DHT_ROUTING
  if (dhtlog_handle != NULL)
    dhtlog_handle->insert_dhtkey (NULL, &dht_msg->key);
#endif
  memset(&message_context, 0, sizeof(struct DHT_MessageContext));
  message_context.client = find_active_client (client);
  message_context.key = &dht_msg->key;
  message_context.unique_id = GNUNET_ntohll (dht_msg->unique_id);
  message_context.replication = ntohl (dht_msg->desired_replication_level);
  message_context.msg_options = ntohl (dht_msg->options);
  message_context.network_size = estimate_diameter();
  message_context.peer = &my_identity;

  route_message(cls, enc_msg, &message_context);

  GNUNET_SERVER_receive_done (client, GNUNET_OK);

}

/**
 * Handler for any generic DHT stop messages, calls the appropriate handler
 * depending on message type (if processed locally)
 *
 * @param cls closure for the service
 * @param client the client we received this message from
 * @param message the actual message received
 *
 */
static void
handle_dht_local_route_stop(void *cls, struct GNUNET_SERVER_Client *client,
                            const struct GNUNET_MessageHeader *message)
{

  const struct GNUNET_DHT_StopMessage *dht_stop_msg =
    (const struct GNUNET_DHT_StopMessage *) message;
  struct DHTQueryRecord *record;
  struct DHTRouteSource *pos;
  uint64_t uid;
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Received `%s' request from client, uid %llu\n", my_short_id, "DHT",
              "GENERIC STOP", GNUNET_ntohll (dht_stop_msg->unique_id));
#endif

  uid = GNUNET_ntohll(dht_stop_msg->unique_id);

  record = GNUNET_CONTAINER_multihashmap_get(forward_list.hashmap, &dht_stop_msg->key);
  if (record != NULL)
    {
      pos = record->head;

      while (pos != NULL)
        {
          if ((pos->client != NULL) && (pos->client->client_handle == client))
            {
              GNUNET_SCHEDULER_cancel(sched, pos->delete_task);
              GNUNET_SCHEDULER_add_now(sched, &remove_forward_entry, pos);
            }
          pos = pos->next;
        }
    }

  GNUNET_SERVER_receive_done (client, GNUNET_OK);
}


/**
 * Core handler for p2p route requests.
 */
static int
handle_dht_p2p_route_request (void *cls,
			      const struct GNUNET_PeerIdentity *peer,
			      const struct GNUNET_MessageHeader *message,
			      struct GNUNET_TIME_Relative latency, uint32_t distance)
{
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Received P2P request from peer %s\n", my_short_id, "DHT", GNUNET_i2s(peer));
#endif
  struct GNUNET_DHT_P2PRouteMessage *incoming = (struct GNUNET_DHT_P2PRouteMessage *)message;
  struct GNUNET_MessageHeader *enc_msg = (struct GNUNET_MessageHeader *)&incoming[1];
  struct DHT_MessageContext *message_context;

  if (ntohs(enc_msg->size) > GNUNET_SERVER_MAX_MESSAGE_SIZE)
    {
      GNUNET_break_op(0);
      return GNUNET_YES;
    }
  //memset(&message_context, 0, sizeof(struct DHT_MessageContext));
  message_context = GNUNET_malloc(sizeof (struct DHT_MessageContext));
  message_context->bloom = GNUNET_CONTAINER_bloomfilter_init(incoming->bloomfilter, DHT_BLOOM_SIZE, DHT_BLOOM_K);
  GNUNET_assert(message_context->bloom != NULL);
  message_context->hop_count = ntohl(incoming->hop_count);
  message_context->key = &incoming->key;
  message_context->replication = ntohl(incoming->desired_replication_level);
  message_context->unique_id = GNUNET_ntohll(incoming->unique_id);
  message_context->msg_options = ntohl(incoming->options);
  message_context->network_size = ntohl(incoming->network_size);
  message_context->peer = peer;
  route_message(cls, enc_msg, message_context);
  GNUNET_free(message_context);
  return GNUNET_YES;
}


/**
 * Core handler for p2p route results.
 */
static int
handle_dht_p2p_route_result (void *cls,
			     const struct GNUNET_PeerIdentity *peer,
			     const struct GNUNET_MessageHeader *message,
			     struct GNUNET_TIME_Relative latency, uint32_t distance)
{
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Received request from peer %s\n", my_short_id, "DHT", GNUNET_i2s(peer));
#endif
  struct GNUNET_DHT_P2PRouteResultMessage *incoming = (struct GNUNET_DHT_P2PRouteResultMessage *)message;
  struct GNUNET_MessageHeader *enc_msg = (struct GNUNET_MessageHeader *)&incoming[1];
  struct DHT_MessageContext message_context;

  if (ntohs(enc_msg->size) > GNUNET_SERVER_MAX_MESSAGE_SIZE)
    {
      GNUNET_break_op(0);
      return GNUNET_YES;
    }
  memset(&message_context, 0, sizeof(struct DHT_MessageContext));
  message_context.bloom = GNUNET_CONTAINER_bloomfilter_init(incoming->bloomfilter, DHT_BLOOM_SIZE, DHT_BLOOM_K);
  GNUNET_assert(message_context.bloom != NULL);
  message_context.key = &incoming->key;
  message_context.unique_id = GNUNET_ntohll(incoming->unique_id);
  message_context.msg_options = ntohl(incoming->options);
  message_context.hop_count = ntohl(incoming->hop_count);
  message_context.peer = peer;
  route_result_message(cls, enc_msg, &message_context);
  return GNUNET_YES;
}


/**
 * Receive the HELLO from transport service,
 * free current and replace if necessary.
 *
 * @param cls NULL
 * @param message HELLO message of peer
 */
static void
process_hello (void *cls, const struct GNUNET_MessageHeader *message)
{
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Received our `%s' from transport service\n",
              "HELLO");
#endif

  GNUNET_assert (message != NULL);
  GNUNET_free_non_null(my_hello);
  my_hello = GNUNET_malloc(ntohs(message->size));
  memcpy(my_hello, message, ntohs(message->size));
}

/**
 * Task run during shutdown.
 *
 * @param cls unused
 * @param tc unused
 */
static void
shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  int bucket_count;
  struct PeerInfo *pos;

  if (transport_handle != NULL)
  {
    GNUNET_free_non_null(my_hello);
    GNUNET_TRANSPORT_get_hello_cancel(transport_handle, &process_hello, NULL);
    GNUNET_TRANSPORT_disconnect(transport_handle);
  }

  for (bucket_count = lowest_bucket; bucket_count < MAX_BUCKETS; bucket_count++)
    {
      while (k_buckets[bucket_count].head != NULL)
        {
          pos = k_buckets[bucket_count].head;
#if DEBUG_DHT
          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                      "%s:%s Removing peer %s from bucket %d!\n", my_short_id, "DHT", GNUNET_i2s(&pos->id), bucket_count);
#endif
          delete_peer(pos, bucket_count);
        }
    }
  if (coreAPI != NULL)
    {
#if DEBUG_DHT
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "%s:%s Disconnecting core!\n", my_short_id, "DHT");
#endif
      GNUNET_CORE_disconnect (coreAPI);
    }
  if (datacache != NULL)
    {
#if DEBUG_DHT
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "%s:%s Destroying datacache!\n", my_short_id, "DHT");
#endif
      GNUNET_DATACACHE_destroy (datacache);
    }

  if (dhtlog_handle != NULL)
    GNUNET_DHTLOG_disconnect(dhtlog_handle);

  GNUNET_free_non_null(my_short_id);
}


/**
 * To be called on core init/fail.
 *
 * @param cls service closure
 * @param server handle to the server for this service
 * @param identity the public identity of this peer
 * @param publicKey the public key of this peer
 */
void
core_init (void *cls,
           struct GNUNET_CORE_Handle *server,
           const struct GNUNET_PeerIdentity *identity,
           const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *publicKey)
{

  if (server == NULL)
    {
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Connection to core FAILED!\n", "dht",
              GNUNET_i2s (identity));
#endif
      GNUNET_SCHEDULER_cancel (sched, cleanup_task);
      GNUNET_SCHEDULER_add_now (sched, &shutdown_task, NULL);
      return;
    }
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s: Core connection initialized, I am peer: %s\n", "dht",
              GNUNET_i2s (identity));
#endif
  /* Copy our identity so we can use it */
  memcpy (&my_identity, identity, sizeof (struct GNUNET_PeerIdentity));
  my_short_id = GNUNET_strdup(GNUNET_i2s(&my_identity));
  /* Set the server to local variable */
  coreAPI = server;

  if (dhtlog_handle != NULL)
    dhtlog_handle->insert_node (NULL, &my_identity);
}


static struct GNUNET_SERVER_MessageHandler plugin_handlers[] = {
  {&handle_dht_local_route_request, NULL, GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE, 0},
  {&handle_dht_local_route_stop, NULL, GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE_STOP, 0},
  {NULL, NULL, 0, 0}
};


static struct GNUNET_CORE_MessageHandler core_handlers[] = {
  {&handle_dht_p2p_route_request, GNUNET_MESSAGE_TYPE_DHT_P2P_ROUTE, 0},
  {&handle_dht_p2p_route_result, GNUNET_MESSAGE_TYPE_DHT_P2P_ROUTE_RESULT, 0},
  {NULL, 0, 0}
};

/**
 * Method called whenever a peer connects.
 *
 * @param cls closure
 * @param peer peer identity this notification is about
 * @param latency reported latency of the connection with peer
 * @param distance reported distance (DV) to peer
 */
void handle_core_connect (void *cls,
                          const struct GNUNET_PeerIdentity * peer,
                          struct GNUNET_TIME_Relative latency,
                          uint32_t distance)
{
  int ret;

#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "%s:%s Receives core connect message for peer %s distance %d!\n", my_short_id, "dht", GNUNET_i2s(peer), distance);
#endif
  if (datacache != NULL)
    GNUNET_DATACACHE_put(datacache, &peer->hashPubKey, sizeof(struct GNUNET_PeerIdentity), (const char *)peer, 0, GNUNET_TIME_absolute_get_forever());
  ret = try_add_peer(peer,
                     find_current_bucket(&peer->hashPubKey),
                     latency,
                     distance);
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "%s:%s Adding peer to routing list: %s\n", my_short_id, "DHT", ret == GNUNET_YES ? "PEER ADDED" : "NOT ADDED");
#endif
}

/**
 * Process dht requests.
 *
 * @param cls closure
 * @param scheduler scheduler to use
 * @param server the initialized server
 * @param c configuration to use
 */
static void
run (void *cls,
     struct GNUNET_SCHEDULER_Handle *scheduler,
     struct GNUNET_SERVER_Handle *server,
     const struct GNUNET_CONFIGURATION_Handle *c)
{
  sched = scheduler;
  cfg = c;
  datacache = GNUNET_DATACACHE_create (sched, cfg, "dhtcache");
  GNUNET_SERVER_add_handlers (server, plugin_handlers);
  coreAPI = GNUNET_CORE_connect (sched, /* Main scheduler */
                                 cfg,   /* Main configuration */
                                 GNUNET_TIME_UNIT_FOREVER_REL,
                                 NULL,  /* Closure passed to DHT functionas around? */
                                 &core_init,    /* Call core_init once connected */
                                 &handle_core_connect,  /* Don't care about connects */
                                 NULL,  /* FIXME: remove peers on disconnects */
                                 NULL,  /* Do we care about "status" updates? */
                                 NULL,  /* Don't want notified about all incoming messages */
                                 GNUNET_NO,     /* For header only inbound notification */
                                 NULL,  /* Don't want notified about all outbound messages */
                                 GNUNET_NO,     /* For header only outbound notification */
                                 core_handlers);        /* Register these handlers */

  if (coreAPI == NULL)
    return;
  transport_handle = GNUNET_TRANSPORT_connect(sched, cfg, 
					      NULL, NULL, NULL, NULL, NULL);
  if (transport_handle != NULL)
    GNUNET_TRANSPORT_get_hello (transport_handle, &process_hello, NULL);
  else
    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Failed to connect to transport service!\n");

  lowest_bucket = MAX_BUCKETS - 1;
  forward_list.hashmap = GNUNET_CONTAINER_multihashmap_create(MAX_OUTSTANDING_FORWARDS / 10);
  forward_list.minHeap = GNUNET_CONTAINER_heap_create(GNUNET_CONTAINER_HEAP_ORDER_MIN);
  /* Scheduled the task to clean up when shutdown is called */

  if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno(cfg, "dht_testing", "mysql_logging"))
    {
      debug_routes = GNUNET_YES;
    }

  if (GNUNET_YES ==
      GNUNET_CONFIGURATION_get_value_yesno(cfg, "dht",
                                           "stop_on_closest"))
    {
      stop_on_closest = GNUNET_YES;
    }

  if (GNUNET_YES ==
      GNUNET_CONFIGURATION_get_value_yesno(cfg, "dht",
                                           "stop_found"))
    {
      stop_on_found = GNUNET_YES;
    }

  if (GNUNET_YES ==
      GNUNET_CONFIGURATION_get_value_yesno(cfg, "dht_testing",
                                           "mysql_logging_extended"))
    {
      debug_routes = GNUNET_YES;
      debug_routes_extended = GNUNET_YES;
    }

  if (GNUNET_YES == debug_routes)
    {
      dhtlog_handle = GNUNET_DHTLOG_connect(cfg);
      if (dhtlog_handle == NULL)
        {
          GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                      "Could not connect to mysql logging server, logging will not happen!");
        }
    }

  GNUNET_SCHEDULER_add_delayed (sched,
                                GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 30),
                                &send_find_peer_message, NULL);

  cleanup_task = GNUNET_SCHEDULER_add_delayed (sched,
                                               GNUNET_TIME_UNIT_FOREVER_REL,
                                               &shutdown_task, NULL);
}

/**
 * The main function for the dht 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,
                              "dht",
                              GNUNET_SERVICE_OPTION_NONE,
                              &run, NULL)) ? 0 : 1;
}