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

/*
     This file is part of GNUnet.
     (C) 2009, 2010, 2011 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 GNUnet DHT service
 * @author Christian Grothoff
 * @author Nathan Evans
 *
 * TODO:
 * - use OPTION_MULTIPLE instead of linked list for the forward_list.hashmap
 * - use different 'struct DHT_MessageContext' for the different types of
 *   messages (currently rather confusing, especially with things like
 *   peer bloom filters occuring when processing replies).
 */

#include "platform.h"
#include "gnunet_block_lib.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_nse_service.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 "gnunet_statistics_service.h"
#include "dht.h"
#include <fenv.h>


/**
 * Defines whether find peer requests send their HELLO's outgoing,
 * or expect replies to contain hellos.
 */
#define FIND_PEER_WITH_HELLO GNUNET_YES

#define DEFAULT_CORE_QUEUE_SIZE 32

/**
 * 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

/**
 * Number of requests we track at most (for routing replies).
 */
#define DHT_MAX_RECENT (1024 * 16)

/**
 * How long do we wait at most when queueing messages with core
 * that we are sending on behalf of other peers.
 */
#define DHT_DEFAULT_P2P_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 10)

/**
 * Default importance for handling messages on behalf of other peers.
 */
#define DHT_DEFAULT_P2P_IMPORTANCE 0

/**
 * How long to keep recent requests around by default.
 */
#define DEFAULT_RECENT_REMOVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 60)

/**
 * Default time to wait to send find peer messages sent by the dht service.
 */
#define DHT_DEFAULT_FIND_PEER_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)

/**
 * Default importance for find peer messages sent by the dht service.
 */
#define DHT_DEFAULT_FIND_PEER_IMPORTANCE 8

/**
 * Default replication parameter for find peer messages sent by the dht service.
 */
#define DHT_DEFAULT_FIND_PEER_REPLICATION 4

/**
 * How long at least to wait before sending another find peer request.
 */
#define DHT_MINIMUM_FIND_PEER_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 2)

/**
 * How long at most to wait before sending another find peer request.
 */
#define DHT_MAXIMUM_FIND_PEER_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 8)

/**
 * How often to update our preference levels for peers in our routing tables.
 */
#define DHT_DEFAULT_PREFERENCE_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 2)

/**
 * How long at most on average will we allow a reply forward to take
 * (before we quit sending out new requests)
 */
#define MAX_REQUEST_TIME GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)

/**
 * How many time differences between requesting a core send and
 * the actual callback to remember.
 */
#define MAX_REPLY_TIMES 8




/**
 * 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.
   */
  struct GNUNET_PeerIdentity peer;

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

  /**
   * extended query (see gnunet_block_lib.h).
   */
  const void *xquery;

  /**
   * Bloomfilter to filter out duplicate replies.
   */
  struct GNUNET_CONTAINER_BloomFilter *reply_bf;

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

  /**
   * How long should we wait to transmit this request?
   */
  struct GNUNET_TIME_Relative timeout;

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

  /**
   * Number of bytes in xquery.
   */
  size_t xquery_size;

  /**
   * Mutator value for the reply_bf, see gnunet_block_lib.h
   */
  uint32_t reply_bf_mutator;

  /**
   * 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;

  /**
   * How many peer identities are present in the path history?
   */
  uint32_t path_history_len;

  /**
   * Path history.
   */
  char *path_history;

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

  /**
   * Should we (still) forward the request on to other peers?
   */
  int do_forward;

  /**
   * 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;

  /**
   * UID of the request, 0 if from another peer.
   */
  uint64_t uid;

  /**
   * 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;

  /**
   * Bloomfilter of peers we have already sent back as
   * replies to the initial request.  Allows us to not
   * forward the same peer multiple times for a find peer
   * request.
   */
  struct GNUNET_CONTAINER_BloomFilter *find_peers_responded;

};


/**
 * 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;

};


/**
 * Context used to calculate the number of find peer messages
 * per X time units since our last scheduled find peer message
 * was sent.  If we have seen too many messages, delay or don't
 * send our own out.
 */
struct FindPeerMessageContext
{
  unsigned int count;

  struct GNUNET_TIME_Absolute start;

};


struct RecentRequest
{
  /**
   * Position of this node in the min heap.
   */
  struct GNUNET_CONTAINER_HeapNode *heap_node;

  /**
   * Bloomfilter containing entries for peers
   * we forwarded this request to.
   */
  struct GNUNET_CONTAINER_BloomFilter *bloom;

  /**
   * Timestamp of this request, for ordering
   * the min heap.
   */
  struct GNUNET_TIME_Absolute timestamp;

  /**
   * Key of this request.
   */
  GNUNET_HashCode key;

  /**
   * Unique identifier for this request, 0 if from another peer.
   */
  uint64_t uid;

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


/**
 * Recent requests by time inserted.
 */
static struct GNUNET_CONTAINER_Heap *recent_heap;

/**
 * Context to use to calculate find peer rates.
 */
static struct FindPeerMessageContext find_peer_context;

/**
 * How many peers have we added since we sent out our last
 * find peer request?
 */
static unsigned int newly_found_peers;

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

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

/**
 * Handle to get our current HELLO.
 */
static struct GNUNET_TRANSPORT_GetHelloHandle *ghh;

/**
 * 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;

/**
 * Recently seen find peer requests.
 */
static struct GNUNET_CONTAINER_MultiHashMap *recent_find_peer_requests;

/**
 * Reply times for requests, if we are busy, don't send any
 * more requests!
 */
static struct GNUNET_TIME_Relative reply_times[MAX_REPLY_TIMES];

/**
 * Current counter for replies.
 */
static unsigned int reply_counter;

/**
 * Our handle to the BLOCK library.
 */
static struct GNUNET_BLOCK_Context *block_context;



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



/**
 * Given the largest send delay, artificially decrease it
 * so the next time around we may have a chance at sending
 * again.
 */
static void
decrease_max_send_delay (struct GNUNET_TIME_Relative max_time)
{
  unsigned int i;

  for (i = 0; i < MAX_REPLY_TIMES; i++)
  {
    if (reply_times[i].rel_value == max_time.rel_value)
    {
      reply_times[i].rel_value = reply_times[i].rel_value / 2;
      return;
    }
  }
}


/**
 * Find the maximum send time of the recently sent values.
 *
 * @return the average time between asking core to send a message
 *         and when the buffer for copying it is passed
 */
static struct GNUNET_TIME_Relative
get_max_send_delay ()
{
  unsigned int i;
  struct GNUNET_TIME_Relative max_time;

  max_time = GNUNET_TIME_relative_get_zero ();

  for (i = 0; i < MAX_REPLY_TIMES; i++)
  {
    if (reply_times[i].rel_value > max_time.rel_value)
      max_time.rel_value = reply_times[i].rel_value;
  }
#if DEBUG_DHT
  if (max_time.rel_value > MAX_REQUEST_TIME.rel_value)
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Max send delay was %llu\n",
                (unsigned long long) max_time.rel_value);
#endif
  return max_time;
}


static void
increment_stats (const char *value)
{
  if (stats == NULL)
    return;
  GNUNET_STATISTICS_update (stats, value, 1, GNUNET_NO);
}


static void
decrement_stats (const char *value)
{
  if (stats == NULL)
    return;
  GNUNET_STATISTICS_update (stats, value, -1, GNUNET_NO);
}


/**
 *  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) != 0)
    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
    pending->scheduled = GNUNET_TIME_absolute_get ();
    reply_counter++;
    if (reply_counter >= MAX_REPLY_TIMES)
      reply_counter = 0;
    peer->th =
        GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES,
                                           pending->importance,
                                           pending->timeout, &peer->id, ssize,
                                           &core_transmit_notify, peer);
    if (peer->th == NULL)
      increment_stats ("# notify transmit ready failed");
  }
}


/**
 * Function called to send a request out to another peer.
 * Called both for locally initiated requests and those
 * received from other peers.
 *
 * @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 (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;
  char *path_start;
  char *path_offset;

  increment_stats (STAT_RESULT_FORWARDS);
  msize =
      sizeof (struct GNUNET_DHT_P2PRouteResultMessage) + ntohs (msg->size) +
      (sizeof (struct GNUNET_PeerIdentity) * msg_ctx->path_history_len);
  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->outgoing_path_length = htonl (msg_ctx->path_history_len);
  if (msg_ctx->path_history_len > 0)
  {
    /* End of pending is where enc_msg starts */
    path_start = (char *) &pending[1];
    /* Offset by the size of the enc_msg */
    path_start += ntohs (msg->size);
    memcpy (path_start, msg_ctx->path_history,
            msg_ctx->path_history_len * (sizeof (struct GNUNET_PeerIdentity)));
  }
  result_message->options = htonl (msg_ctx->msg_options);
  result_message->hop_count = htonl (msg_ctx->hop_count + 1);
  memcpy (&result_message->key, &msg_ctx->key, sizeof (GNUNET_HashCode));
  /* Copy the enc_msg, then the path history as well! */
  memcpy (&result_message[1], msg, ntohs (msg->size));
  path_offset = (char *) &result_message[1];
  path_offset += ntohs (msg->size);
  /* If we have path history, copy it to the end of the whole thing */
  if (msg_ctx->path_history_len > 0)
    memcpy (path_offset, msg_ctx->path_history,
            msg_ctx->path_history_len * (sizeof (struct GNUNET_PeerIdentity)));
#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
  peer->pending_count++;
  increment_stats ("# pending messages scheduled");
  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 (&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
 */
static 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;

  peer->th = NULL;
  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;

  off = 0;
  pending = peer->head;
  while (NULL != pending &&
         (size - off >= (msize = ntohs (pending->msg->size))))
  {
    memcpy (&cbuf[off], pending->msg, msize);
    off += msize;
    peer->pending_count--;
    increment_stats ("# pending messages sent");
    GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending);
    GNUNET_free (pending);
    pending = peer->head;
  }
  if ((peer->head != NULL) && (peer->send_task == GNUNET_SCHEDULER_NO_TASK))
    peer->send_task = GNUNET_SCHEDULER_add_now (&try_core_send, peer);

  return off;
}


/**
 * 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 = GNUNET_CRYPTO_hash_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 (GNUNET_CRYPTO_hash_matching_bits (target, have) == 0)
    return 1;                   /* Never return 0! */
  return ((unsigned int) -1) - distance (target, have);
}


/**
 * 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 lowest_bucket;
  if (actual_bucket < lowest_bucket)    /* actual_bucket not yet used */
    return lowest_bucket;
  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 (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))
    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. */
}

/* Forward declaration */
static void
update_core_preference (void *cls,
                        const struct GNUNET_SCHEDULER_TaskContext *tc);


/**
 * Function called with statistics about the given peer.
 *
 * @param cls closure
 * @param peer identifies the peer
 * @param bpm_out set to the current bandwidth limit (sending) for this peer
 * @param amount set to the amount that was actually reserved or unreserved;
 *               either the full requested amount or zero (no partial reservations)
 * @param res_delay if the reservation could not be satisfied (amount was 0), how
 *        long should the client wait until re-trying?
 * @param preference current traffic preference for the given peer
 */
static void
update_core_preference_finish (void *cls,
                               const struct GNUNET_PeerIdentity *peer,
                               struct GNUNET_BANDWIDTH_Value32NBO bpm_out,
                               int32_t amount,
                               struct GNUNET_TIME_Relative res_delay,
                               uint64_t preference)
{
  struct PeerInfo *peer_info = cls;

  peer_info->info_ctx = NULL;
  GNUNET_SCHEDULER_add_delayed (DHT_DEFAULT_PREFERENCE_INTERVAL,
                                &update_core_preference, peer_info);
}

static void
update_core_preference (void *cls,
                        const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct PeerInfo *peer = cls;
  uint64_t preference;
  unsigned int matching;

  if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
  {
    return;
  }
  matching =
      GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey,
                                        &peer->id.hashPubKey);
  if (matching >= 64)
  {
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "Peer identifier matches by %u bits, only shifting as much as we can!\n",
                matching);
#endif
    matching = 63;
  }
  preference = 1LL << matching;
  peer->info_ctx =
      GNUNET_CORE_peer_change_preference (coreAPI, &peer->id,
                                          GNUNET_TIME_UNIT_FOREVER_REL,
                                          GNUNET_BANDWIDTH_VALUE_MAX, 0,
                                          preference,
                                          &update_core_preference_finish, peer);
}

/**
 * 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;
  int count;

  lowest_distance = -1;

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

  current_closest = NULL;
  for (bucket = lowest_bucket; bucket < MAX_BUCKETS; bucket++)
  {
    pos = k_buckets[bucket].head;
    count = 0;
    while ((pos != NULL) && (count < bucket_size))
    {
      temp_distance = distance (&pos->id.hashPubKey, hc);
      if (temp_distance <= lowest_distance)
      {
        lowest_distance = temp_distance;
        current_closest = pos;
      }
      pos = pos->next;
      count++;
    }
  }
  GNUNET_assert (current_closest != NULL);
  return current_closest;
}


/**
 * Function called to send a request out to another peer.
 * Called both for locally initiated requests and those
 * received from other peers.
 *
 * @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 (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;
  char *route_path;

  increment_stats (STAT_ROUTE_FORWARDS);
  GNUNET_assert (peer != NULL);
  if ((msg_ctx->closest != GNUNET_YES) &&
      (peer == find_closest_peer (&msg_ctx->key)))
    increment_stats (STAT_ROUTE_FORWARDS_CLOSEST);

  msize =
      sizeof (struct GNUNET_DHT_P2PRouteMessage) + ntohs (msg->size) +
      (msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity));
  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 = msg_ctx->importance;
  pending->timeout = msg_ctx->timeout;
  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);
  if (msg_ctx->bloom != NULL)
    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 (GNUNET_DHT_RO_RECORD_ROUTE ==
      (msg_ctx->msg_options & GNUNET_DHT_RO_RECORD_ROUTE))
  {
    route_message->outgoing_path_length = htonl (msg_ctx->path_history_len);
    /* Set pointer to start of enc_msg */
    route_path = (char *) &route_message[1];
    /* Offset to the end of the enc_msg */
    route_path += ntohs (msg->size);
    /* Copy the route_path after enc_msg */
    memcpy (route_path, msg_ctx->path_history,
            msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity));
  }
#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
  peer->pending_count++;
  increment_stats ("# pending messages scheduled");
  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 (&try_core_send, peer);
}




/**
 * 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 msg_ctx the context of the received message
 */
static void
send_reply_to_client (struct ClientList *client,
                      const struct GNUNET_MessageHeader *message,
                      struct DHT_MessageContext *msg_ctx)
{
  struct GNUNET_DHT_RouteResultMessage *reply;
  struct PendingMessage *pending_message;
  uint16_t msize;
  size_t tsize;
  char *reply_offset;

#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 +
      (msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity));
  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->outgoing_path_length = htonl (msg_ctx->path_history_len);
  reply->unique_id = GNUNET_htonll (msg_ctx->unique_id);
  memcpy (&reply->key, &msg_ctx->key, sizeof (GNUNET_HashCode));
  reply_offset = (char *) &reply[1];
  memcpy (&reply[1], message, msize);
  if (msg_ctx->path_history_len > 0)
  {
    reply_offset += msize;
    memcpy (reply_offset, msg_ctx->path_history,
            msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity));
  }
  add_pending_message (client, pending_message);
}

/**
 * Consider whether or not we would like to have this peer added to
 * our routing table.  Check whether bucket for this peer is full,
 * if so return negative; if not return positive.  Since peers are
 * only added on CORE level connect, this doesn't actually add the
 * peer to the routing table.
 *
 * @param peer the peer we are considering adding
 *
 * @return GNUNET_YES if we want this peer, GNUNET_NO if not (bucket
 *         already full)
 */
static int
consider_peer (struct GNUNET_PeerIdentity *peer)
{
  int bucket;

  if ((GNUNET_YES ==
       GNUNET_CONTAINER_multihashmap_contains (all_known_peers,
                                               &peer->hashPubKey)) ||
      (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity))))
    return GNUNET_NO;           /* We already know this peer (are connected even!) */
  bucket = find_current_bucket (&peer->hashPubKey);

  if ((k_buckets[bucket].peers_size < bucket_size) ||
      ((bucket == lowest_bucket) && (lowest_bucket > 0)))
    return GNUNET_YES;

  return GNUNET_NO;
}


/**
 * 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 (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);
  }
  if (source_info->find_peers_responded != NULL)
    GNUNET_CONTAINER_bloomfilter_free (source_info->find_peers_responded);
  GNUNET_free (source_info);
}

/**
 * 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
 * @param msg_ctx context of the message we are routing
 *
 * @return the number of peers the message was routed to,
 *         GNUNET_SYSERR on failure
 */
static int
route_result_message (struct GNUNET_MessageHeader *msg,
                      struct DHT_MessageContext *msg_ctx)
{
  struct GNUNET_PeerIdentity new_peer;
  struct DHTQueryRecord *record;
  struct DHTRouteSource *pos;
  struct PeerInfo *peer_info;
  const struct GNUNET_MessageHeader *hello_msg;

#if DEBUG_DHT > 1
  unsigned int i;
#endif

  increment_stats (STAT_RESULTS);
  /**
   * If a find peer result message is received and contains a valid
   * HELLO for another peer, offer it to the transport service.
   */
  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_SYSERR ==
         GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) hello_msg,
                              &new_peer)))
    {
      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);
      return GNUNET_NO;
    }
    else                        /* We have a valid hello, and peer id stored in new_peer */
    {
      find_peer_context.count++;
      increment_stats (STAT_FIND_PEER_REPLY);
      if (GNUNET_YES == consider_peer (&new_peer))
      {
        increment_stats (STAT_HELLOS_PROVIDED);
        GNUNET_TRANSPORT_offer_hello (transport_handle, hello_msg, NULL, NULL);
        GNUNET_CORE_peer_request_connect (coreAPI, &new_peer, NULL, NULL);
      }
    }
  }

  record =
    GNUNET_CONTAINER_multihashmap_get (forward_list.hashmap, &msg_ctx->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 (&msg_ctx->key),
                msg_ctx->unique_id);
#endif
    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 (&msg_ctx->key),
                  msg_ctx->unique_id);
#endif
      increment_stats (STAT_RESULTS_TO_CLIENT);
      if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_DHT_GET_RESULT)
        increment_stats (STAT_GET_REPLY);
#if DEBUG_DHT > 1
      for (i = 0; i < msg_ctx->path_history_len; i++)
      {
        char *path_offset;

        path_offset =
            &msg_ctx->path_history[i * sizeof (struct GNUNET_PeerIdentity)];
        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                    "(before client) Key %s Found peer %d:%s\n",
                    GNUNET_h2s (&msg_ctx->key), i,
                    GNUNET_i2s ((struct GNUNET_PeerIdentity *) path_offset));
      }
#endif
      send_reply_to_client (pos->client, msg, msg_ctx);
    }
    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 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 (&msg_ctx->key),
		  msg_ctx->unique_id, GNUNET_i2s (&peer_info->id));
#endif
      forward_result_message (msg, peer_info, msg_ctx);
      /* Try removing forward entries after sending once, only allows ONE response per request */
      if (pos->delete_task != GNUNET_SCHEDULER_NO_TASK)
      {
	GNUNET_SCHEDULER_cancel (pos->delete_task);
	pos->delete_task =
	  GNUNET_SCHEDULER_add_now (&remove_forward_entry, pos);        
      }
    }
    pos = pos->next;
  }
  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, size_t size,
                        const char *data, enum GNUNET_BLOCK_Type type)
{
  struct DHT_MessageContext *msg_ctx = cls;
  struct DHT_MessageContext new_msg_ctx;
  struct GNUNET_DHT_GetResultMessage *get_result;
  enum GNUNET_BLOCK_EvaluationResult eval;
  const struct DHTPutEntry *put_entry;
  int get_size;
  char *path_offset;

#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Received `%s' response from datacache\n", my_short_id,
              "DHT", "GET");
#endif

  put_entry = (const struct DHTPutEntry *) data;

  if (size !=
      sizeof (struct DHTPutEntry) + put_entry->data_size +
      (put_entry->path_length * sizeof (struct GNUNET_PeerIdentity)))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "Path + data size doesn't add up for data inserted into datacache!\nData size %d, path length %d, expected %d, got %d\n",
                put_entry->data_size, put_entry->path_length,
                sizeof (struct DHTPutEntry) + put_entry->data_size +
                (put_entry->path_length * sizeof (struct GNUNET_PeerIdentity)),
                size);
    msg_ctx->do_forward = GNUNET_NO;
    return GNUNET_OK;
  }

  eval =
      GNUNET_BLOCK_evaluate (block_context, type, key, &msg_ctx->reply_bf,
                             msg_ctx->reply_bf_mutator, msg_ctx->xquery,
                             msg_ctx->xquery_size, &put_entry[1],
                             put_entry->data_size);

  switch (eval)
  {
  case GNUNET_BLOCK_EVALUATION_OK_LAST:
    msg_ctx->do_forward = GNUNET_NO;
  case GNUNET_BLOCK_EVALUATION_OK_MORE:
    memcpy (&new_msg_ctx, msg_ctx, sizeof (struct DHT_MessageContext));
    if (GNUNET_DHT_RO_RECORD_ROUTE ==
        (msg_ctx->msg_options & GNUNET_DHT_RO_RECORD_ROUTE))
    {
      new_msg_ctx.msg_options = GNUNET_DHT_RO_RECORD_ROUTE;
    }

    get_size =
        sizeof (struct GNUNET_DHT_GetResultMessage) + put_entry->data_size +
        (put_entry->path_length * sizeof (struct GNUNET_PeerIdentity));
    get_result = GNUNET_malloc (get_size);
    get_result->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_GET_RESULT);
    get_result->header.size = htons (get_size);
    get_result->expiration = GNUNET_TIME_absolute_hton (exp);
    get_result->type = htons (type);
    get_result->put_path_length = htons (put_entry->path_length);
    path_offset = (char *) &put_entry[1];
    path_offset += put_entry->data_size;
    /* Copy the actual data and the path_history to the end of the get result */
    memcpy (&get_result[1], &put_entry[1],
            put_entry->data_size +
            (put_entry->path_length * sizeof (struct GNUNET_PeerIdentity)));
    new_msg_ctx.peer = my_identity;
    new_msg_ctx.bloom = NULL;
    new_msg_ctx.hop_count = 0;
    new_msg_ctx.importance = DHT_DEFAULT_P2P_IMPORTANCE + 2;   /* Make result routing a higher priority */
    new_msg_ctx.timeout = DHT_DEFAULT_P2P_TIMEOUT;
    increment_stats (STAT_GET_RESPONSE_START);
    route_result_message (&get_result->header, &new_msg_ctx);
    GNUNET_free (get_result);
    break;
  case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Duplicate block error\n",
                my_short_id, "DHT");
#endif
    break;
  case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "`%s:%s': Invalid request error\n",
                my_short_id, "DHT");
#endif
    break;
  case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "`%s:%s': Valid request, no results.\n", my_short_id, "DHT");
#endif
    GNUNET_break (0);
    break;
  case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
    GNUNET_break_op (0);
    msg_ctx->do_forward = GNUNET_NO;
    break;
  case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "`%s:%s': Unsupported block type (%u) in response!\n",
                my_short_id, "DHT", type);
#endif
    /* msg_ctx->do_forward = GNUNET_NO;  // not sure... */
    break;
  }
  return GNUNET_OK;
}


/**
 * Main function that handles whether or not to route a message to other
 * peers.
 *
 * @param msg the message to be routed
 * @param msg_ctx the context containing all pertinent information about the message
 */
static void
route_message (const struct GNUNET_MessageHeader *msg,
               struct DHT_MessageContext *msg_ctx);


/**
 * Server handler for all dht get requests, look for data,
 * if found, send response either to clients or other peers.
 *
 * @param msg the actual get message
 * @param msg_ctx struct containing pertinent information about the get request
 *
 * @return number of items found for GET request
 */
static unsigned int
handle_dht_get (const struct GNUNET_MessageHeader *msg,
                struct DHT_MessageContext *msg_ctx)
{
  const struct GNUNET_DHT_GetMessage *get_msg;
  uint16_t msize;
  uint16_t bf_size;
  unsigned int results;
  const char *end;
  enum GNUNET_BLOCK_Type type;

  msize = ntohs (msg->size);
  if (msize < sizeof (struct GNUNET_DHT_GetMessage))
  {
    GNUNET_break (0);
    return 0;
  }
  get_msg = (const struct GNUNET_DHT_GetMessage *) msg;
  bf_size = ntohs (get_msg->bf_size);
  msg_ctx->xquery_size = ntohs (get_msg->xquery_size);
  msg_ctx->reply_bf_mutator = get_msg->bf_mutator;
  if (msize !=
      sizeof (struct GNUNET_DHT_GetMessage) + bf_size + msg_ctx->xquery_size)
  {
    GNUNET_break_op (0);
    return 0;
  }
  end = (const char *) &get_msg[1];
  if (msg_ctx->xquery_size == 0)
  {
    msg_ctx->xquery = NULL;
  }
  else
  {
    msg_ctx->xquery = (const void *) end;
    end += msg_ctx->xquery_size;
  }
  if (bf_size == 0)
  {
    msg_ctx->reply_bf = NULL;
  }
  else
  {
    msg_ctx->reply_bf =
        GNUNET_CONTAINER_bloomfilter_init (end, bf_size,
                                           GNUNET_DHT_GET_BLOOMFILTER_K);
  }
  type = (enum GNUNET_BLOCK_Type) ntohl (get_msg->type);
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s:%s': Received `%s' request, message type %u, key %s, uid %llu\n",
              my_short_id, "DHT", "GET", type, GNUNET_h2s (&msg_ctx->key),
              msg_ctx->unique_id);
#endif
  increment_stats (STAT_GETS);
  results = 0;
  msg_ctx->do_forward = GNUNET_YES;
  if (datacache != NULL)
    results =
        GNUNET_DATACACHE_get (datacache, &msg_ctx->key, type,
                              &datacache_get_iterator, msg_ctx);
#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", msg_ctx->unique_id);
#endif
  if (results >= 1)
  {
  }
  else
  {
    /* check query valid */
    if (GNUNET_BLOCK_EVALUATION_REQUEST_INVALID ==
        GNUNET_BLOCK_evaluate (block_context, type, &msg_ctx->key,
                               &msg_ctx->reply_bf, msg_ctx->reply_bf_mutator,
                               msg_ctx->xquery, msg_ctx->xquery_size, NULL, 0))
    {
      GNUNET_break_op (0);
      msg_ctx->do_forward = GNUNET_NO;
    }
  }

  if (msg_ctx->do_forward == GNUNET_YES)
    route_message (msg, msg_ctx);
  GNUNET_CONTAINER_bloomfilter_free (msg_ctx->reply_bf);
  return results;
}


static void
remove_recent_find_peer (void *cls,
                         const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  GNUNET_HashCode *key = cls;

  GNUNET_assert (GNUNET_YES ==
                 GNUNET_CONTAINER_multihashmap_remove
                 (recent_find_peer_requests, key, NULL));
  GNUNET_free (key);
}


/**
 * Server handler for initiating local dht find peer requests
 *
 * @param find_msg the actual find peer message
 * @param msg_ctx struct containing pertinent information about the request
 *
 */
static void
handle_dht_find_peer (const struct GNUNET_MessageHeader *find_msg,
                      struct DHT_MessageContext *msg_ctx)
{
  struct GNUNET_MessageHeader *find_peer_result;
  struct GNUNET_DHT_FindPeerMessage *find_peer_message;
  struct DHT_MessageContext *new_msg_ctx;
  struct GNUNET_CONTAINER_BloomFilter *incoming_bloom;
  size_t hello_size;
  size_t tsize;
  GNUNET_HashCode *recent_hash;
  struct GNUNET_MessageHeader *other_hello;
  size_t other_hello_size;
  struct GNUNET_PeerIdentity peer_id;

  find_peer_message = (struct GNUNET_DHT_FindPeerMessage *) find_msg;
  GNUNET_break_op (ntohs (find_msg->size) >=
                   (sizeof (struct GNUNET_DHT_FindPeerMessage)));
  if (ntohs (find_msg->size) < sizeof (struct GNUNET_DHT_FindPeerMessage))
    return;
  other_hello = NULL;
  other_hello_size = 0;
  if (ntohs (find_msg->size) > sizeof (struct GNUNET_DHT_FindPeerMessage))
  {
    other_hello_size =
        ntohs (find_msg->size) - sizeof (struct GNUNET_DHT_FindPeerMessage);
    other_hello = GNUNET_malloc (other_hello_size);
    memcpy (other_hello, &find_peer_message[1], other_hello_size);
    if ((GNUNET_HELLO_size ((struct GNUNET_HELLO_Message *) other_hello) == 0)
        || (GNUNET_OK !=
            GNUNET_HELLO_get_id ((struct GNUNET_HELLO_Message *) other_hello,
                                 &peer_id)))
    {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                  "Received invalid HELLO message in find peer request!\n");
      GNUNET_free (other_hello);
      return;
    }
#if FIND_PEER_WITH_HELLO
    if (GNUNET_YES == consider_peer (&peer_id))
    {
      increment_stats (STAT_HELLOS_PROVIDED);
      GNUNET_TRANSPORT_offer_hello (transport_handle, other_hello, NULL, NULL);
      GNUNET_CORE_peer_request_connect (coreAPI, &peer_id, NULL, NULL);
      route_message (find_msg, msg_ctx);
      GNUNET_free (other_hello);
      return;
    }
    else                        /* We don't want this peer! */
    {
      route_message (find_msg, msg_ctx);
      GNUNET_free (other_hello);
      return;
    }
#endif
  }

#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 (&msg_ctx->key),
              ntohs (find_msg->size), sizeof (struct GNUNET_MessageHeader));
#endif
  if (my_hello == NULL)
  {
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "`%s': Our HELLO is null, can't return.\n", "DHT");
#endif
    GNUNET_free_non_null (other_hello);
    route_message (find_msg, msg_ctx);
    return;
  }

  incoming_bloom =
      GNUNET_CONTAINER_bloomfilter_init (find_peer_message->bloomfilter,
                                         DHT_BLOOM_SIZE, DHT_BLOOM_K);
  if (GNUNET_YES ==
      GNUNET_CONTAINER_bloomfilter_test (incoming_bloom,
                                         &my_identity.hashPubKey))
  {
    increment_stats (STAT_BLOOM_FIND_PEER);
    GNUNET_CONTAINER_bloomfilter_free (incoming_bloom);
    GNUNET_free_non_null (other_hello);
    route_message (find_msg, msg_ctx);
    return;                     /* We match the bloomfilter, do not send a response to this peer (they likely already know us!) */
  }
  GNUNET_CONTAINER_bloomfilter_free (incoming_bloom);

  /**
   * Ignore any find peer requests from a peer we have seen very recently.
   */
  if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains (recent_find_peer_requests, &msg_ctx->key))  /* We have recently responded to a find peer request for this peer! */
  {
    increment_stats ("# dht find peer requests ignored (recently seen!)");
    GNUNET_free_non_null (other_hello);
    return;
  }

  /**
   * Use this check to only allow the peer to respond to find peer requests if
   * it would be beneficial to have the requesting peer in this peers routing
   * table.  Can be used to thwart peers flooding the network with find peer
   * requests that we don't care about.  However, if a new peer is joining
   * the network and has no other peers this is a problem (assume all buckets
   * full, no one will respond!).
   */
  memcpy (&peer_id.hashPubKey, &msg_ctx->key, sizeof (GNUNET_HashCode));
  if (GNUNET_NO == consider_peer (&peer_id))
  {
    increment_stats ("# dht find peer requests ignored (do not need!)");
    GNUNET_free_non_null (other_hello);
    route_message (find_msg, msg_ctx);
    return;
  }

  recent_hash = GNUNET_malloc (sizeof (GNUNET_HashCode));
  memcpy (recent_hash, &msg_ctx->key, sizeof (GNUNET_HashCode));
  if (GNUNET_SYSERR !=
      GNUNET_CONTAINER_multihashmap_put (recent_find_peer_requests,
                                         &msg_ctx->key, NULL,
                                         GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
  {
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Adding recent remove task for key `%s`!\n",
                GNUNET_h2s (&msg_ctx->key));
#endif
    /* Only add a task if there wasn't one for this key already! */
    GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply
                                  (GNUNET_TIME_UNIT_SECONDS, 30),
                                  &remove_recent_find_peer, recent_hash);
  }
  else
  {
    GNUNET_free (recent_hash);
#if DEBUG_DHT
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Received duplicate find peer request too soon!\n");
#endif
  }

  /* 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);
    GNUNET_free_non_null (other_hello);
    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);
#if DEBUG_DHT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "`%s': Sending hello size %d to requesting peer.\n", "DHT",
              hello_size);
#endif

  new_msg_ctx = GNUNET_malloc (sizeof (struct DHT_MessageContext));
  memcpy (new_msg_ctx, msg_ctx, 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;
  new_msg_ctx->importance = DHT_DEFAULT_P2P_IMPORTANCE + 2;     /* Make find peer requests a higher priority */
  new_msg_ctx->timeout = DHT_DEFAULT_P2P_TIMEOUT;
  increment_stats (STAT_FIND_PEER_ANSWER);
  if (GNUNET_DHT_RO_RECORD_ROUTE ==
      (msg_ctx->msg_options & GNUNET_DHT_RO_RECORD_ROUTE))
  {
    new_msg_ctx->msg_options = GNUNET_DHT_RO_RECORD_ROUTE;
    new_msg_ctx->path_history_len = msg_ctx->path_history_len;
    /* Assign to previous msg_ctx path history, caller should free after our return */
    new_msg_ctx->path_history = msg_ctx->path_history;
  }
  route_result_message (find_peer_result, new_msg_ctx);
  GNUNET_free (new_msg_ctx);
  GNUNET_free_non_null (other_hello);
  GNUNET_free (find_peer_result);
  route_message (find_msg, msg_ctx);
}


/**
 * Server handler for initiating local dht put requests
 *
 * @param msg the actual put message
 * @param msg_ctx struct containing pertinent information about the request
 */
static void
handle_dht_put (const struct GNUNET_MessageHeader *msg,
                struct DHT_MessageContext *msg_ctx)
{
  const struct GNUNET_DHT_PutMessage *put_msg;
  struct DHTPutEntry *put_entry;
  unsigned int put_size;
  char *path_offset;
  enum GNUNET_BLOCK_Type put_type;
  size_t data_size;
  int ret;
  GNUNET_HashCode key;
  struct DHTQueryRecord *record;

  GNUNET_assert (ntohs (msg->size) >= sizeof (struct GNUNET_DHT_PutMessage));

  put_msg = (const struct GNUNET_DHT_PutMessage *) msg;
  put_type = (enum GNUNET_BLOCK_Type) ntohl (put_msg->type);
  data_size =
      ntohs (put_msg->header.size) - sizeof (struct GNUNET_DHT_PutMessage);
  ret =
      GNUNET_BLOCK_get_key (block_context, put_type, &put_msg[1], data_size,
                            &key);
  if (GNUNET_NO == ret)
  {
    /* invalid reply */
    GNUNET_break_op (0);
    return;
  }
  if ((GNUNET_YES == ret) &&
      (0 != memcmp (&key, &msg_ctx->key, sizeof (GNUNET_HashCode))))
  {
    /* invalid wrapper: key mismatch! */
    GNUNET_break_op (0);
    return;
  }
  /* ret == GNUNET_SYSERR means that there is no known relationship between
   * data and the key, so we cannot check it */
#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 (&msg_ctx->key),
              msg_ctx->unique_id);
#endif

  record = GNUNET_CONTAINER_multihashmap_get(forward_list.hashmap,
                                             &msg_ctx->key);
  if (NULL != record)
  {
    struct DHTRouteSource *pos;
    struct GNUNET_DHT_GetResultMessage *get_result;
    struct DHT_MessageContext new_msg_ctx;
    size_t get_size;

    pos = record->head;
    while (pos != NULL)
    {
      /* TODO: do only for local started requests? or also for remote peers? */
      /* TODO: include this in statistics? under what? */
      /* TODO: reverse order of path_history? */
      if (NULL == pos->client)
      {
        pos = pos->next;
        continue;
      }

      memcpy (&new_msg_ctx, msg_ctx, sizeof (struct DHT_MessageContext));
      if (GNUNET_DHT_RO_RECORD_ROUTE ==
          (msg_ctx->msg_options & GNUNET_DHT_RO_RECORD_ROUTE))
      {
        new_msg_ctx.msg_options = GNUNET_DHT_RO_RECORD_ROUTE;
      }

      get_size =
          sizeof (struct GNUNET_DHT_GetResultMessage) + data_size +
          (msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity));
      get_result = GNUNET_malloc (get_size);
      get_result->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_GET_RESULT);
      get_result->header.size = htons (get_size);
      get_result->expiration = put_msg->expiration;
      get_result->type = put_msg->type;
      get_result->put_path_length = htons (msg_ctx->path_history_len);

      /* Copy the actual data and the path_history to the end of the get result */
      memcpy (&get_result[1], &put_msg[1], data_size);
      path_offset = (char *) &get_result[1];
      path_offset += data_size;
      memcpy (path_offset, msg_ctx->path_history,
              msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity));
      new_msg_ctx.peer = my_identity;
      new_msg_ctx.bloom = NULL;
      new_msg_ctx.hop_count = 0;
      /* Make result routing a higher priority */
      new_msg_ctx.importance = DHT_DEFAULT_P2P_IMPORTANCE + 2;
      new_msg_ctx.timeout = DHT_DEFAULT_P2P_TIMEOUT;
      new_msg_ctx.unique_id = pos->uid;
      send_reply_to_client(pos->client, &get_result->header, &new_msg_ctx);
      GNUNET_free (get_result);
      pos = pos->next;
    }
  }

  if (msg_ctx->closest != GNUNET_YES)
  {
    route_message (msg, msg_ctx);
    return;
  }

#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 (&msg_ctx->key),
              msg_ctx->unique_id);
#endif

  increment_stats (STAT_PUTS_INSERTED);
  if (datacache != NULL)
  {
    /* Put size is actual data size plus struct overhead plus path length (if any) */
    put_size =
        data_size + sizeof (struct DHTPutEntry) +
        (msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity));
    put_entry = GNUNET_malloc (put_size);
    put_entry->data_size = data_size;
    put_entry->path_length = msg_ctx->path_history_len;
    /* Copy data to end of put entry */
    memcpy (&put_entry[1], &put_msg[1], data_size);
    if (msg_ctx->path_history_len > 0)
    {
      /* Copy path after data */
      path_offset = (char *) &put_entry[1];
      path_offset += data_size;
      memcpy (path_offset, msg_ctx->path_history,
              msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity));
    }

    ret =
        GNUNET_DATACACHE_put (datacache, &msg_ctx->key, put_size,
                              (const char *) put_entry, put_type,
                              GNUNET_TIME_absolute_ntoh (put_msg->expiration));
    GNUNET_free (put_entry);
  }
  else
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "`%s:%s': %s request received, but have no datacache!\n",
                my_short_id, "DHT", "PUT");

  route_message (msg, msg_ctx);
}


/**
 * To how many peers should we (on average)
 * forward the request to obtain the desired
 * target_replication count (on average).
 *
 * returns: target_replication / (est. hops) + (target_replication * hop_count)
 * where est. hops is typically 2 * the routing table depth
 *
 * @param hop_count number of hops the message has traversed
 * @param target_replication the number of total paths desired
 *
 * @return Some number of peers to forward the message to
 */
static unsigned int
get_forward_count (unsigned int hop_count, size_t target_replication)
{
  uint32_t random_value;
  unsigned int forward_count;
  float target_value;

  if (hop_count > log_of_network_size_estimate * 4.0)
  {
    /* forcefully terminate */
    return 0;
  }

  if (hop_count > log_of_network_size_estimate * 2.0)
  {
    /* keep forwarding, but no more replication */
    return 1;
  }

  target_value =
    1 + (target_replication - 1.0) / (log_of_network_size_estimate +
				      ((float) (target_replication - 1.0) *
				       hop_count));
  /* Set forward count to floor of target_value */
  forward_count = (unsigned int) target_value;
  /* Subtract forward_count (floor) from target_value (yields value between 0 and 1) */
  target_value = target_value - forward_count;
  random_value =
    GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG, UINT32_MAX); 
  if (random_value < (target_value * UINT32_MAX))
    forward_count++;
  return forward_count;
}


/**
 * Check whether my identity is closer than any known peers.
 * If a non-null bloomfilter is given, check if this is the closest
 * peer that hasn't already been routed to.
 *
 * @param target hash code to check closeness to
 * @param bloom bloomfilter, exclude these entries from the decision
 * @return GNUNET_YES if node location is closest,
 *         GNUNET_NO otherwise.
 */
static int
am_closest_peer (const GNUNET_HashCode * target,
                 struct GNUNET_CONTAINER_BloomFilter *bloom)
{
  int bits;
  int other_bits;
  int bucket_num;
  int count;
  struct PeerInfo *pos;
  unsigned int my_distance;

  if (0 == memcmp (&my_identity.hashPubKey, target, sizeof (GNUNET_HashCode)))
    return GNUNET_YES;

  bucket_num = find_current_bucket (target);

  bits = GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey, target);
  my_distance = distance (&my_identity.hashPubKey, target);
  pos = k_buckets[bucket_num].head;
  count = 0;
  while ((pos != NULL) && (count < bucket_size))
  {
    if ((bloom != NULL) &&
        (GNUNET_YES ==
         GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)))
    {
      pos = pos->next;
      continue;                 /* Skip already checked entries */
    }

    other_bits = GNUNET_CRYPTO_hash_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 */
    {
      if (distance (&pos->id.hashPubKey, target) < my_distance) /* Check all known peers, only return if we are the true closest */
        return GNUNET_NO;
    }
    pos = pos->next;
  }

  /* 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
 * @param hops how many hops has this message traversed thus far
 *
 * @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 hops)
{
  unsigned int bc;
  unsigned int count;
  unsigned int selected;
  struct PeerInfo *pos;
  unsigned int distance;
  unsigned int largest_distance;
  struct PeerInfo *chosen;

  if (hops >= log_of_network_size_estimate)
  {
    /* greedy selection (closest peer that is not in bloomfilter) */
    largest_distance = 0;
    chosen = NULL;
    for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++)
    {
      pos = k_buckets[bc].head;
      count = 0;
      while ((pos != NULL) && (count < bucket_size))
      {
        /* If we are doing strict Kademlia routing, then checking the bloomfilter is basically cheating! */
        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;
          }
        }
        count++;
        pos = pos->next;
      }
    }
    if ((largest_distance > 0) && (chosen != NULL))
    {
      GNUNET_CONTAINER_bloomfilter_add (bloom, &chosen->id.hashPubKey);
      return chosen;
    }
    return NULL;                /* no peer available or we are the closest */
  }


  /* select "random" peer */
  /* count number of peers that are available and not filtered */
  count = 0;
  for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++)
  {
    pos = k_buckets[bc].head;
    while ((pos != NULL) && (count < bucket_size))
    {
      if (GNUNET_YES ==
          GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey))
      {
        pos = pos->next;
	increment_stats ("# peer blocked from selection by Bloom filter");
        continue;               /* Ignore bloomfiltered peers */
      }
      count++;
      pos = pos->next;
    }
  }
  if (count == 0)               /* No peers to select from! */
  {
    increment_stats ("# failed to select peer");
    return NULL;
  }
  /* Now actually choose a peer */
  selected = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, count);
  count = 0;
  for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++)
  {
    pos = k_buckets[bc].head;
    while ((pos != NULL) && (count < bucket_size))
    {
      if (GNUNET_YES ==
          GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey))
      {
        pos = pos->next;
        continue;               /* Ignore bloomfiltered peers */
      }
      if (0 == selected--)
        return pos;
      pos = pos->next;
    }
  }
  GNUNET_break (0);
  return NULL;
}


/**
 * 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 msg_ctx Context of the route request
 *
 * @return GNUNET_YES if this response was cached, GNUNET_NO if not
 */
static int
cache_response (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);
    GNUNET_assert (source_info != NULL);
    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);
    }
    if (source_info->delete_task != GNUNET_SCHEDULER_NO_TASK)
    {
      GNUNET_SCHEDULER_cancel (source_info->delete_task);
      source_info->delete_task = GNUNET_SCHEDULER_NO_TASK;
    }
    if (source_info->find_peers_responded != NULL)
      GNUNET_CONTAINER_bloomfilter_free (source_info->find_peers_responded);
    GNUNET_free (source_info);
    current_size = GNUNET_CONTAINER_multihashmap_size (forward_list.hashmap);
  }

  /** Non-local request and have too many outstanding forwards, discard! */
  if ((current_size >= MAX_OUTSTANDING_FORWARDS) && (msg_ctx->client == NULL))
    return GNUNET_NO;

  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.abs_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 (DHT_FORWARD_TIMEOUT, &remove_forward_entry,
                                    source_info);
  source_info->find_peers_responded =
      GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K);
  source_info->source = msg_ctx->peer;
  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.abs_value);
  source_info->uid = msg_ctx->unique_id;
#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
 * @param msg_ctx the context containing all pertinent information about the message
 */
static void
route_message (const struct GNUNET_MessageHeader *msg,
               struct DHT_MessageContext *msg_ctx)
{
  int i;
  struct PeerInfo *selected;
  unsigned int target_forward_count;
  unsigned int forward_count;
  struct RecentRequest *recent_req;
  char *stat_forward_count;
  char *temp_stat_str;

  increment_stats (STAT_ROUTES);
  target_forward_count =
      get_forward_count (msg_ctx->hop_count, msg_ctx->replication);
  GNUNET_asprintf (&stat_forward_count, "# forward counts of %d",
                   target_forward_count);
  increment_stats (stat_forward_count);
  GNUNET_free (stat_forward_count);
  if (msg_ctx->bloom == NULL)
    msg_ctx->bloom =
        GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K);

  if (GNUNET_CONTAINER_heap_get_size (recent_heap) >= DHT_MAX_RECENT)
  {
    recent_req = GNUNET_CONTAINER_heap_peek (recent_heap);
    GNUNET_assert (recent_req != NULL);
    GNUNET_SCHEDULER_cancel (recent_req->remove_task);
    GNUNET_CONTAINER_heap_remove_node (recent_req->heap_node);
    GNUNET_CONTAINER_bloomfilter_free (recent_req->bloom);
    GNUNET_free (recent_req);
  }

  recent_req = GNUNET_malloc (sizeof (struct RecentRequest));
  recent_req->uid = msg_ctx->unique_id;
  memcpy (&recent_req->key, &msg_ctx->key, sizeof (GNUNET_HashCode));
  recent_req->heap_node =
    GNUNET_CONTAINER_heap_insert (recent_heap, recent_req,
				  GNUNET_TIME_absolute_get ().abs_value);
  recent_req->bloom =
    GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K);

  forward_count = 0;
  for (i = 0; i < target_forward_count; i++)
  {
    selected = select_peer (&msg_ctx->key, msg_ctx->bloom, msg_ctx->hop_count);
    if (selected == NULL)
      break;    
    forward_count++;
    if (GNUNET_CRYPTO_hash_matching_bits
	(&selected->id.hashPubKey,
	 &msg_ctx->key) >=
	GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey,
					  &msg_ctx->key))
      GNUNET_asprintf (&temp_stat_str,
		       "# requests routed to close(r) peer hop %u",
		       msg_ctx->hop_count);
    else
      GNUNET_asprintf (&temp_stat_str,
		       "# requests routed to less close peer hop %u",
		       msg_ctx->hop_count);
    if (temp_stat_str != NULL)
    {
      increment_stats (temp_stat_str);
      GNUNET_free (temp_stat_str);
    }
    GNUNET_CONTAINER_bloomfilter_add (msg_ctx->bloom,
				      &selected->id.hashPubKey);
    forward_message (msg, selected, msg_ctx);    
  }

  if (msg_ctx->bloom != NULL)
  {
    GNUNET_CONTAINER_bloomfilter_or2 (recent_req->bloom, msg_ctx->bloom,
                                      DHT_BLOOM_SIZE);
    GNUNET_CONTAINER_bloomfilter_free (msg_ctx->bloom);
    msg_ctx->bloom = NULL;
  }
}


/**
 * Main function that handles whether or not to route a message to other
 * peers.
 *
 * @param msg the message to be routed
 * @param msg_ctx the context containing all pertinent information about the message
 */
static void
demultiplex_message (const struct GNUNET_MessageHeader *msg,
                     struct DHT_MessageContext *msg_ctx)
{
  /* FIXME: Should we use closest excluding those we won't route to (the bloomfilter problem)? */
  msg_ctx->closest = am_closest_peer (&msg_ctx->key, msg_ctx->bloom);

  switch (ntohs (msg->type))
  {
  case GNUNET_MESSAGE_TYPE_DHT_GET:    /* Add to hashmap of requests seen, search for data (always) */
    cache_response (msg_ctx);
    handle_dht_get (msg, msg_ctx);
    break;
  case GNUNET_MESSAGE_TYPE_DHT_PUT:    /* Check if closest, if so insert data. */
    increment_stats (STAT_PUTS);
    handle_dht_put (msg, msg_ctx);
    break;
  case GNUNET_MESSAGE_TYPE_DHT_FIND_PEER:      /* Check if closest and not started by us, check options, add to requests seen */
    increment_stats (STAT_FIND_PEER);
    if (((msg_ctx->hop_count > 0) &&
         (0 !=
          memcmp (&msg_ctx->peer, &my_identity,
                  sizeof (struct GNUNET_PeerIdentity)))) ||
        (msg_ctx->client != NULL))
    {
      cache_response (msg_ctx);
      if ((msg_ctx->closest == GNUNET_YES) ||
          (msg_ctx->msg_options == GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE))
        handle_dht_find_peer (msg, msg_ctx);
    }
    else
      route_message (msg, msg_ctx);
    break;
  default:
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "`%s': Message type (%d) not handled, forwarding anyway!\n",
                "DHT", ntohs (msg->type));
    route_message (msg, msg_ctx);
  }
}


/**
 * 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 (NULL != ghh)
  {
    GNUNET_TRANSPORT_get_hello_cancel (ghh);
    ghh = NULL;
  }
  if (transport_handle != NULL)
  {
    GNUNET_free_non_null (my_hello);
    GNUNET_TRANSPORT_disconnect (transport_handle);
    transport_handle = NULL;
  }
  GDS_NEIGHBOURS_done ();
  GDS_NSE_done ();
  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 (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);
    datacache = NULL;
  }
  if (stats != NULL)
  {
    GNUNET_STATISTICS_destroy (stats, GNUNET_YES);
    stats = NULL;
  }
  if (block_context != NULL)
  {
    GNUNET_BLOCK_context_destroy (block_context);
    block_context = NULL;
  }
}



/**
 * Process dht 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)
{
  struct GNUNET_TIME_Relative next_send_time;
  unsigned long long temp_config_num;

  cfg = c;
  datacache = GNUNET_DATACACHE_create (cfg, "dhtcache");
  coreAPI = GNUNET_CORE_connect (cfg,   /* Main configuration */
                                 DEFAULT_CORE_QUEUE_SIZE,       /* queue size */
                                 NULL,  /* Closure passed to DHT functions */
                                 &core_init,    /* Call core_init once connected */
                                 &handle_core_connect,  /* Handle connects */
                                 &handle_core_disconnect,       /* 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 (cfg, NULL, NULL, NULL, NULL, NULL);
  if (transport_handle != NULL)
    ghh = GNUNET_TRANSPORT_get_hello (transport_handle, &process_hello, NULL);
  else
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "Failed to connect to transport service!\n");
  block_context = GNUNET_BLOCK_context_create (cfg);
  lowest_bucket = MAX_BUCKETS - 1;
  all_known_peers = GNUNET_CONTAINER_multihashmap_create (MAX_BUCKETS / 8);
  GNUNET_assert (all_known_peers != NULL);

  if (GNUNET_OK ==
      GNUNET_CONFIGURATION_get_value_number (cfg, "DHT", "bucket_size",
                                             &temp_config_num))
  {
    bucket_size = (unsigned int) temp_config_num;
  }

  stats = GNUNET_STATISTICS_create ("dht", cfg);
  next_send_time.rel_value =
    DHT_MINIMUM_FIND_PEER_INTERVAL.rel_value +
    GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_STRONG,
			      (DHT_MAXIMUM_FIND_PEER_INTERVAL.rel_value /
			       2) -
			      DHT_MINIMUM_FIND_PEER_INTERVAL.rel_value);
  find_peer_context.start = GNUNET_TIME_absolute_get ();
  GNUNET_SCHEDULER_add_delayed (next_send_time, &send_find_peer_message,
				&find_peer_context);  

  /* 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 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)
{
  int ret;
  struct RecentRequest *recent_req;

  recent_heap =
    GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
  recent_find_peer_requests =
      GNUNET_CONTAINER_multihashmap_create (MAX_BUCKETS / 8);
  ret =
      (GNUNET_OK ==
       GNUNET_SERVICE_run (argc, argv, "dht", GNUNET_SERVICE_OPTION_NONE, &run,
                           NULL)) ? 0 : 1;
  while (GNUNET_CONTAINER_heap_get_size (recent_heap) > 0)
  {
    recent_req = GNUNET_CONTAINER_heap_peek (recent_heap);
    GNUNET_assert (recent_req != NULL);
    GNUNET_CONTAINER_heap_remove_node (recent_req->heap_node);
    GNUNET_CONTAINER_bloomfilter_free (recent_req->bloom);
    GNUNET_free (recent_req);
  }
  GNUNET_CONTAINER_heap_destroy (recent_heap);
  recent_heap = NULL;
  GNUNET_CONTAINER_multihashmap_destroy (recent_find_peer_requests);
  recent_find_peer_requests = NULL;
  return ret;
}

/* end of gnunet-service-dht.c */