remove SHA-512 code, use libgcrypt implementation
[oweals/gnunet.git] / src / dht / dht_api.c
index 1dbf32ea8feb581c94f28247357bac3b828aed51..17a21568197d450841debff7a6e95edab88131bb 100644 (file)
@@ -4,7 +4,7 @@
 
      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 2, or (at your
+     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
@@ -23,7 +23,6 @@
  * @brief library to access the DHT service
  * @author Christian Grothoff
  * @author Nathan Evans
- *
  */
 
 #include "platform.h"
 #include "gnunet_dht_service.h"
 #include "dht.h"
 
-#define DEBUG_DHT_API GNUNET_YES
-
-#define DEFAULT_DHT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
+#define DEBUG_DHT_API GNUNET_NO
 
+/**
+ * Entry in our list of messages to be (re-)transmitted.
+ */
 struct PendingMessage
 {
   /**
-   * Message that is pending
+   * This is a doubly-linked list.
    */
-  struct GNUNET_MessageHeader *msg;
+  struct PendingMessage *prev;
 
   /**
-   * Timeout for this message
+   * This is a doubly-linked list.
    */
-  struct GNUNET_TIME_Relative timeout;
+  struct PendingMessage *next;
 
   /**
-   * Continuation to call on message send
-   * or message receipt confirmation
+   * Message that is pending, allocated at the end
+   * of this struct.
+   */
+  const struct GNUNET_MessageHeader *msg;
+  
+  /**
+   * Handle to the DHT API context.
+   */
+  struct GNUNET_DHT_Handle *handle;
+                       
+  /**
+   * Continuation to call when the request has been
+   * transmitted (for the first time) to the service; can be NULL.
    */
   GNUNET_SCHEDULER_Task cont;
 
   /**
-   * Continuation closure
+   * Closure for 'cont'.
    */
   void *cont_cls;
 
   /**
-   * Whether or not to await verification the message
-   * was received by the service
+   * Timeout task for this message
    */
-  size_t is_unique;
+  GNUNET_SCHEDULER_TaskIdentifier timeout_task;
 
   /**
    * Unique ID for this request
    */
   uint64_t unique_id;
 
-};
-
-struct GNUNET_DHT_GetContext
-{
   /**
-   * Iterator to call on data receipt
+   * Free the saved message once sent, set to GNUNET_YES for messages
+   * that do not receive responses; GNUNET_NO if this pending message
+   * is aliased from a 'struct GNUNET_DHT_RouteHandle' and will be freed
+   * from there.
    */
-  GNUNET_DHT_GetIterator iter;
+  int free_on_send;
 
   /**
-   * Closure for the iterator callback
+   * GNUNET_YES if this message is in our pending queue right now.
    */
-  void *iter_cls;
+  int in_pending_queue;
 
 };
 
-struct GNUNET_DHT_FindPeerContext
-{
-  /**
-   * Iterator to call on data receipt
-   */
-  GNUNET_DHT_FindPeerProcessor proc;
-
-  /**
-   * Closure for the iterator callback
-   */
-  void *proc_cls;
-
-};
 
 /**
- * Handle to control a unique operation (one that is
- * expected to return results)
+ * Handle to a route request
  */
 struct GNUNET_DHT_RouteHandle
 {
 
-  /**
-   * Unique identifier for this request (for key collisions)
-   */
-  uint64_t uid;
-
-  /**
-   * Key that this get request is for
-   */
-  GNUNET_HashCode key;
-
   /**
    * Iterator to call on data receipt
    */
@@ -138,67 +123,24 @@ struct GNUNET_DHT_RouteHandle
    * Main handle to this DHT api
    */
   struct GNUNET_DHT_Handle *dht_handle;
-};
-
-/**
- * Handle for a non unique request, holds callback
- * which needs to be called before we allow other
- * messages to be processed and sent to the DHT service
- */
-struct GNUNET_DHT_NonUniqueHandle
-{
-  /**
-   * Key that this get request is for
-   */
-  GNUNET_HashCode key;
-
-  /**
-   * Type of data get request was for
-   */
-  uint32_t type;
-
-  /**
-   * Continuation to call on service
-   * confirmation of message receipt.
-   */
-  GNUNET_SCHEDULER_Task cont;
 
   /**
-   * Send continuation cls
+   * The actual message sent for this request,
+   * used for retransmitting requests on service
+   * failure/reconnect.  Freed on route_stop.
    */
-  void *cont_cls;
-};
+  struct PendingMessage *message;
 
-/**
- * Handle to control a get operation.
- */
-struct GNUNET_DHT_GetHandle
-{
   /**
-   * Handle to the actual route operation for the get
+   * Key that this get request is for
    */
-  struct GNUNET_DHT_RouteHandle *route_handle;
+  GNUNET_HashCode key;
 
   /**
-   * The context of the get request
+   * Unique identifier for this request (for key collisions). FIXME: redundant!?
    */
-  struct GNUNET_DHT_GetContext get_context;
-};
-
-/**
- * Handle to control a find peer operation.
- */
-struct GNUNET_DHT_FindPeerHandle
-{
-  /**
-     * Handle to the actual route operation for the request
-     */
-  struct GNUNET_DHT_RouteHandle *route_handle;
+  uint64_t uid;
 
-    /**
-     * The context of the get request
-     */
-  struct GNUNET_DHT_FindPeerContext find_peer_context;
 };
 
 
@@ -223,467 +165,479 @@ struct GNUNET_DHT_Handle
   struct GNUNET_CLIENT_Connection *client;
 
   /**
-   * Currently pending transmission request.
+   * Currently pending transmission request (or NULL).
    */
   struct GNUNET_CLIENT_TransmitHandle *th;
 
   /**
-   * Message we are currently sending, only allow
-   * a single message to be queued.  If not unique
-   * (typically a put request), await a confirmation
-   * from the service that the message was received.
-   * If unique, just fire and forget.
+   * Head of linked list of messages we would like to transmit.
    */
-  struct PendingMessage *current;
+  struct PendingMessage *pending_head;
 
   /**
-   * Hash map containing the current outstanding unique requests
+   * Tail of linked list of messages we would like to transmit.
    */
-  struct GNUNET_CONTAINER_MultiHashMap *outstanding_requests;
+  struct PendingMessage *pending_tail;
 
   /**
-   * Non unique handle.  If set don't schedule another non
-   * unique request.
+   * Hash map containing the current outstanding unique requests
+   * (values are of type 'struct GNUNET_DHT_RouteHandle').
    */
-  struct GNUNET_DHT_NonUniqueHandle *non_unique_request;
+  struct GNUNET_CONTAINER_MultiHashMap *active_requests;
 
   /**
-   * Kill off the connection and any pending messages.
+   * Generator for unique ids.
    */
-  int do_destroy;
+  uint64_t uid_gen;
 
 };
 
-static struct GNUNET_TIME_Relative default_request_timeout;
-
-/* Forward declaration */
-static void process_pending_message (struct GNUNET_DHT_Handle *handle);
 
-static GNUNET_HashCode *
-hash_from_uid (uint64_t uid)
-{
-  int count;
-  int remaining;
-  GNUNET_HashCode *hash;
-  hash = GNUNET_malloc (sizeof (GNUNET_HashCode));
-  count = 0;
-
-  while (count < sizeof (GNUNET_HashCode))
-    {
-      remaining = sizeof (GNUNET_HashCode) - count;
-      if (remaining > sizeof (uid))
-        remaining = sizeof (uid);
-
-      memcpy (hash, &uid, remaining);
-      count += remaining;
-    }
+/**
+ * Transmit the next pending message, called by notify_transmit_ready
+ */
+static size_t
+transmit_pending (void *cls,
+                 size_t size, 
+                 void *buf);
 
-  return hash;
-}
 
 /**
  * Handler for messages received from the DHT service
  * a demultiplexer which handles numerous message types
  *
  */
-void
-service_message_handler (void *cls, const struct GNUNET_MessageHeader *msg)
-{
-  struct GNUNET_DHT_Handle *handle = cls;
-  struct GNUNET_DHT_Message *dht_msg;
-  struct GNUNET_DHT_StopMessage *stop_msg;
-  struct GNUNET_MessageHeader *enc_msg;
-  struct GNUNET_DHT_RouteHandle *route_handle;
-  uint64_t uid;
-  GNUNET_HashCode *uid_hash;
-  size_t enc_size;
-  /* TODO: find out message type, handle callbacks for different types of messages.
-   * Should be a non unique acknowledgment, or unique result. */
-
-  if (msg == NULL)
-    {
-#if DEBUG_DHT_API
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "`%s': Received NULL from server, connection down?\n",
-                  "DHT API");
-#endif
-      return;
-    }
+static void
+service_message_handler (void *cls,
+                         const struct GNUNET_MessageHeader *msg);
 
-  switch (ntohs (msg->type))
-    {
-    case GNUNET_MESSAGE_TYPE_DHT:
-      {
-        dht_msg = (struct GNUNET_DHT_Message *) msg;
-        uid = GNUNET_ntohll (dht_msg->unique_id);
-#if DEBUG_DHT_API
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    "`%s': Received response to message (uid %llu)\n",
-                    "DHT API", uid);
-#endif
-        if (ntohs (dht_msg->unique))
-          {
-            uid_hash = hash_from_uid (uid);
-            route_handle =
-              GNUNET_CONTAINER_multihashmap_get (handle->outstanding_requests,
-                                                 uid_hash);
-            GNUNET_free (uid_hash);
-            if (route_handle == NULL)   /* We have no recollection of this request */
-              {
-#if DEBUG_DHT_API
-                GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                            "`%s': Received response to message (uid %llu), but have no recollection of it!\n",
-                            "DHT API", uid);
-#endif
-              }
-            else
-              {
-                enc_size =
-                  ntohs (dht_msg->header.size) -
-                  sizeof (struct GNUNET_DHT_Message);
-                GNUNET_assert (enc_size > 0);
-                enc_msg = (struct GNUNET_MessageHeader *) &dht_msg[1];
-                route_handle->iter (route_handle->iter_cls, enc_msg);
-
-              }
-          }
-        break;
-      }
-    case GNUNET_MESSAGE_TYPE_DHT_STOP:
-      {
-        stop_msg = (struct GNUNET_DHT_StopMessage *) msg;
-        uid = GNUNET_ntohll (stop_msg->unique_id);
-#if DEBUG_DHT_API
-        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                    "`%s': Received response to message (uid %llu), current uid %llu\n",
-                    "DHT API", uid, handle->current->unique_id);
-#endif
-        if (handle->current->unique_id == uid)
-          {
-#if DEBUG_DHT_API
-            GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                        "`%s': Have pending confirmation for this message!\n",
-                        "DHT API", uid);
-#endif
-            if (handle->current->cont != NULL)
-              GNUNET_SCHEDULER_add_continuation (handle->sched,
-                                                 handle->current->cont,
-                                                 handle->current->cont_cls,
-                                                 GNUNET_SCHEDULER_REASON_PREREQ_DONE);
-
-            GNUNET_free (handle->current->msg);
-            GNUNET_free (handle->current);
-            handle->current = NULL;
-          }
-        break;
-      }
-    default:
-      {
-        GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                    "`%s': Received unknown message type %d\n", "DHT API",
-                    ntohs (msg->type));
-      }
-    }
-  GNUNET_CLIENT_receive (handle->client,
-                         &service_message_handler,
-                         handle, GNUNET_TIME_UNIT_FOREVER_REL);
 
-}
 
 
 /**
- * Initialize the connection with the DHT service.
+ * Try to (re)connect to the DHT service.
  *
- * @param sched scheduler to use
- * @param cfg configuration to use
- * @param ht_len size of the internal hash table to use for
- *               processing multiple GET/FIND requests in parallel
- *
- * @return handle to the DHT service, or NULL on error
+ * @return GNUNET_YES on success, GNUNET_NO on failure.
  */
-struct GNUNET_DHT_Handle *
-GNUNET_DHT_connect (struct GNUNET_SCHEDULER_Handle *sched,
-                    const struct GNUNET_CONFIGURATION_Handle *cfg,
-                    unsigned int ht_len)
+static int
+try_connect (struct GNUNET_DHT_Handle *handle)
 {
-  struct GNUNET_DHT_Handle *handle;
-
-  handle = GNUNET_malloc (sizeof (struct GNUNET_DHT_Handle));
-
-  default_request_timeout =
-    GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5);
-  handle->cfg = cfg;
-  handle->sched = sched;
-
-  handle->current = NULL;
-  handle->do_destroy = GNUNET_NO;
-  handle->th = NULL;
-
-  handle->client = GNUNET_CLIENT_connect (sched, "dht", cfg);
-  handle->outstanding_requests =
-    GNUNET_CONTAINER_multihashmap_create (ht_len);
-
+  if (handle->client != NULL)
+    return GNUNET_OK;
+  handle->client = GNUNET_CLIENT_connect (handle->sched, "dht", handle->cfg);
   if (handle->client == NULL)
-    {
-      GNUNET_free (handle);
-      return NULL;
+    { 
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                 _("Failed to connect to the DHT service!\n"));
+      return GNUNET_NO;
     }
-#if DEBUG_DHT_API
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Connection to service in progress\n", "DHT API");
-#endif
+             "Starting to process replies from DHT\n");
   GNUNET_CLIENT_receive (handle->client,
                          &service_message_handler,
-                         handle, GNUNET_TIME_UNIT_FOREVER_REL);
-
-  return handle;
+                         handle, 
+                        GNUNET_TIME_UNIT_FOREVER_REL);
+  return GNUNET_YES;
 }
 
 
 /**
- * Shutdown connection with the DHT service.
+ * Add the request corresponding to the given route handle
+ * to the pending queue (if it is not already in there).
  *
- * @param handle handle of the DHT connection to stop
+ * @param cls the 'struct GNUNET_DHT_Handle*'
+ * @param key key for the request (not used)
+ * @param value the 'struct GNUNET_DHT_RouteHandle*'
+ * @return GNUNET_YES (always)
  */
-void
-GNUNET_DHT_disconnect (struct GNUNET_DHT_Handle *handle)
+static int
+add_request_to_pending (void *cls,
+                       const GNUNET_HashCode *key,
+                       void *value)
 {
-#if DEBUG_DHT_API
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Called GNUNET_DHT_disconnect\n", "DHT API");
-#endif
-  GNUNET_assert (handle != NULL);
+  struct GNUNET_DHT_Handle *handle = cls;
+  struct GNUNET_DHT_RouteHandle *rh = value;
 
-  if (handle->th != NULL)       /* We have a live transmit request in the Aether */
+  if (GNUNET_NO == rh->message->in_pending_queue)
     {
-      GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
-      handle->th = NULL;
+      GNUNET_CONTAINER_DLL_insert (handle->pending_head,
+                                  handle->pending_tail,
+                                  rh->message);
+      rh->message->in_pending_queue = GNUNET_YES;
     }
-  if (handle->current != NULL)  /* We are trying to send something now, clean it up */
-    GNUNET_free (handle->current);
+  return GNUNET_YES;
+}
 
-  if (handle->client != NULL)   /* Finally, disconnect from the service */
+
+/**
+ * Re-connect to the DHT, re-issue all pending requests if needed.
+ */
+static void
+reconnect (struct GNUNET_DHT_Handle *handle)
+{
+  if (handle->client != NULL)
     {
-      GNUNET_CLIENT_disconnect (handle->client, GNUNET_NO);
+      GNUNET_CLIENT_disconnect (handle->client, 
+                               GNUNET_NO);
       handle->client = NULL;
     }
-
-  GNUNET_free (handle);
+  if (GNUNET_YES != try_connect (handle))
+    return;
+  GNUNET_CONTAINER_multihashmap_iterate (handle->active_requests,
+                                        &add_request_to_pending,
+                                        handle);
+  if (handle->pending_head == NULL)
+    return;
+  GNUNET_CLIENT_notify_transmit_ready (handle->client,
+                                      ntohs(handle->pending_head->msg->size),
+                                      GNUNET_TIME_UNIT_FOREVER_REL,
+                                      GNUNET_NO,
+                                      &transmit_pending,
+                                      handle);
+                                      
 }
 
 
 /**
- * Send complete (or failed), schedule next (or don't)
+ * Try to send messages from list of messages to send
  */
 static void
-finish (struct GNUNET_DHT_Handle *handle, int code)
+process_pending_messages (struct GNUNET_DHT_Handle *handle)
 {
-  /* TODO: if code is not GNUNET_OK, do something! */
-  struct PendingMessage *pos = handle->current;
-#if DEBUG_DHT_API
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s': Finish called!\n", "DHT API");
-#endif
-  GNUNET_assert (pos != NULL);
+  struct PendingMessage *head;
 
-  if (pos->is_unique)
+  if (GNUNET_YES != try_connect (handle))
+    return;      
+  if (handle->th != NULL)
+    return;
+  if (NULL == (head = handle->pending_head))
+    return;
+  handle->th = GNUNET_CLIENT_notify_transmit_ready (handle->client,
+                                                   ntohs (head->msg->size),
+                                                   GNUNET_TIME_UNIT_FOREVER_REL, 
+                                                   GNUNET_YES,
+                                                   &transmit_pending,
+                                                   handle);
+  if (NULL == handle->th)    
     {
-      if (pos->cont != NULL)
-        {
-          if (code == GNUNET_SYSERR)
-            GNUNET_SCHEDULER_add_continuation (handle->sched, pos->cont,
-                                               pos->cont_cls,
-                                               GNUNET_SCHEDULER_REASON_TIMEOUT);
-          else
-            GNUNET_SCHEDULER_add_continuation (handle->sched, pos->cont,
-                                               pos->cont_cls,
-                                               GNUNET_SCHEDULER_REASON_PREREQ_DONE);
-        }
-
-      GNUNET_free (pos->msg);
-      handle->current = NULL;
-      GNUNET_free (pos);
+      reconnect (handle);
+      return;
     }
-  /* Otherwise we need to wait for a response to this message! */
 }
 
+
 /**
  * Transmit the next pending message, called by notify_transmit_ready
  */
 static size_t
-transmit_pending (void *cls, size_t size, void *buf)
+transmit_pending (void *cls,
+                 size_t size, 
+                 void *buf)
 {
   struct GNUNET_DHT_Handle *handle = cls;
+  struct PendingMessage *head;
   size_t tsize;
 
-#if DEBUG_DHT_API
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': In transmit_pending\n", "DHT API");
-#endif
+  handle->th = NULL;
   if (buf == NULL)
     {
-#if DEBUG_DHT_API
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "`%s': In transmit_pending buf is NULL\n", "DHT API");
-#endif
-      /* FIXME: free associated resources or summat */
-      finish (handle, GNUNET_SYSERR);
+      reconnect (handle);
       return 0;
     }
-
-  handle->th = NULL;
-
-  if (handle->current != NULL)
+  if (NULL == (head = handle->pending_head))
+    return 0;
+  
+  tsize = ntohs (head->msg->size);
+  if (size < tsize)
     {
-      tsize = ntohs (handle->current->msg->size);
-      if (size >= tsize)
-        {
-#if DEBUG_DHT_API
-          GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                      "`%s': Sending message size %d\n", "DHT API", tsize);
-#endif
-          memcpy (buf, handle->current->msg, tsize);
-          finish (handle, GNUNET_OK);
-          return tsize;
-        }
-      else
-        {
-          return 0;
-        }
+      process_pending_messages (handle);
+      return 0;
     }
-  /* Have no pending request */
-  return 0;
+  memcpy (buf, head->msg, tsize);
+  GNUNET_CONTAINER_DLL_remove (handle->pending_head,
+                              handle->pending_tail,
+                              head);
+  if (head->timeout_task != GNUNET_SCHEDULER_NO_TASK)
+    {
+      GNUNET_SCHEDULER_cancel (handle->sched,
+                              head->timeout_task);
+      head->timeout_task = GNUNET_SCHEDULER_NO_TASK;
+    }
+  if (NULL != head->cont)
+    {
+      GNUNET_SCHEDULER_add_continuation (handle->sched,
+                                         head->cont,
+                                         head->cont_cls,
+                                         GNUNET_SCHEDULER_REASON_PREREQ_DONE);
+      head->cont = NULL;
+      head->cont_cls = NULL;
+    }
+  head->in_pending_queue = GNUNET_NO;
+  if (GNUNET_YES == head->free_on_send)
+    GNUNET_free (head);
+  process_pending_messages (handle);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Forwarded request of %u bytes to DHT service\n",
+             (unsigned int) tsize);
+  return tsize;
 }
 
 
+
+
 /**
- * Try to (re)connect to the dht service.
- *
- * @return GNUNET_YES on success, GNUNET_NO on failure.
+ * Process a given reply that might match the given
+ * request.
  */
 static int
-try_connect (struct GNUNET_DHT_Handle *handle)
+process_reply (void *cls,
+              const GNUNET_HashCode *key,
+              void *value)
 {
-  if (handle->client != NULL)
-    return GNUNET_OK;
-  handle->client = GNUNET_CLIENT_connect (handle->sched, "dht", handle->cfg);
-  if (handle->client != NULL)
-    return GNUNET_YES;
-#if DEBUG_STATISTICS
+  const struct GNUNET_DHT_RouteResultMessage *dht_msg = cls;
+  struct GNUNET_DHT_RouteHandle *rh = value;
+  const struct GNUNET_MessageHeader *enc_msg;
+  size_t enc_size;
+  uint64_t uid;
+  const struct GNUNET_PeerIdentity **get_path;
+  const struct GNUNET_PeerIdentity **put_path;
+  const struct GNUNET_PeerIdentity *pos;
+  uint16_t gpl;
+  uint16_t ppl;
+  unsigned int i;
+
+  uid = GNUNET_ntohll (dht_msg->unique_id);
+  if (uid != rh->uid)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Reply UID did not match request UID\n");
+      return GNUNET_YES;
+    }
+  enc_size = ntohs (dht_msg->header.size) - sizeof (struct GNUNET_DHT_RouteResultMessage);
+  if (enc_size < sizeof (struct GNUNET_MessageHeader))
+    {
+      GNUNET_break (0);
+      return GNUNET_NO;
+    }
+  pos = (const struct GNUNET_PeerIdentity *) &dht_msg[1];
+  ppl = ntohs (dht_msg->put_path_length);
+  gpl = ntohs (dht_msg->get_path_length);
+  if ( (ppl + gpl) * sizeof (struct GNUNET_PeerIdentity) > enc_size)
+    {
+      GNUNET_break (0);
+      return GNUNET_NO;
+    }
+  if (ppl > 0)
+    {
+      put_path = GNUNET_malloc ((ppl+1) * sizeof (struct GNUNET_PeerIdentity*));
+      for (i=0;i<ppl;i++)
+       {
+         put_path[i] = pos;
+         pos++;
+       }
+      put_path[ppl] = NULL;
+    }
+  else
+    put_path = NULL;
+  if (gpl > 0)
+    {
+      get_path = GNUNET_malloc ((gpl+1) * sizeof (struct GNUNET_PeerIdentity*));
+      for (i=0;i<gpl;i++)
+       {
+         get_path[i] = pos;
+         pos++;
+       }
+      get_path[gpl] = NULL;
+    }
+  else
+    get_path = NULL;
+  enc_size -= (ppl + gpl) * sizeof (struct GNUNET_PeerIdentity);
+  enc_msg = (const struct GNUNET_MessageHeader *) pos;
+  if (enc_size != ntohs (enc_msg->size))
+    {
+      GNUNET_break (0);
+      GNUNET_free_non_null (get_path);
+      GNUNET_free_non_null (put_path);
+      return GNUNET_NO;
+    }
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              _("Failed to connect to the dht service!\n"));
-#endif
-  return GNUNET_NO;
+             "Processing reply.\n");
+  rh->iter (rh->iter_cls, 
+           &rh->key,
+           get_path,
+           put_path,
+           enc_msg);
+  GNUNET_free_non_null (get_path);
+  GNUNET_free_non_null (put_path);
+  return GNUNET_YES;
 }
 
 
 /**
- * Try to send messages from list of messages to send
+ * Handler for messages received from the DHT service
+ * a demultiplexer which handles numerous message types
+ *
+ * @param cls the 'struct GNUNET_DHT_Handle'
+ * @param msg the incoming message
  */
 static void
-process_pending_message (struct GNUNET_DHT_Handle *handle)
+service_message_handler (void *cls,
+                         const struct GNUNET_MessageHeader *msg)
 {
+  struct GNUNET_DHT_Handle *handle = cls;
+  const struct GNUNET_DHT_RouteResultMessage *dht_msg;
 
-  if (handle->current == NULL)
-    return;                     /* action already pending */
-  if (GNUNET_YES != try_connect (handle))
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "%s called\n",
+             __FUNCTION__);  
+  if (msg == NULL)
     {
-      finish (handle, GNUNET_SYSERR);
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                 "Error receiving data from DHT service, reconnecting\n");
+      reconnect (handle);
       return;
     }
-
-  /* TODO: set do_destroy somewhere's, see what needs to happen in that case! */
-  if (handle->do_destroy)
+  if (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE_RESULT)
     {
-      //GNUNET_DHT_disconnect (handle); /* FIXME: replace with proper disconnect stuffs */
+      GNUNET_break (0);
+      reconnect (handle);
+      return;
     }
-
-
-  if (NULL ==
-      (handle->th = GNUNET_CLIENT_notify_transmit_ready (handle->client,
-                                                         ntohs (handle->
-                                                                current->msg->
-                                                                size),
-                                                         handle->current->
-                                                         timeout, GNUNET_YES,
-                                                         &transmit_pending,
-                                                         handle)))
+  if (ntohs (msg->size) < sizeof (struct GNUNET_DHT_RouteResultMessage))
     {
-#if DEBUG_DHT_API
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "Failed to transmit request to dht service.\n");
-#endif
-      finish (handle, GNUNET_SYSERR);
+      GNUNET_break (0);
+      reconnect (handle);
+      return;
     }
-#if DEBUG_DHT_API
+  dht_msg = (const struct GNUNET_DHT_RouteResultMessage *) msg;
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Scheduled sending message of size %d to service\n",
-              "DHT API", ntohs (handle->current->msg->size));
-#endif
+             "Comparing reply `%s' against %u pending requests.\n",
+             GNUNET_h2s (&dht_msg->key),
+             GNUNET_CONTAINER_multihashmap_size (handle->active_requests));
+  GNUNET_CONTAINER_multihashmap_get_multiple (handle->active_requests,
+                                             &dht_msg->key,
+                                             &process_reply,
+                                             (void*) dht_msg);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "Continuing to process replies from DHT\n");
+  GNUNET_CLIENT_receive (handle->client,
+                         &service_message_handler,
+                         handle, GNUNET_TIME_UNIT_FOREVER_REL);
+
 }
 
+
 /**
- * Iterator called on each result obtained from a generic route
- * operation
+ * Initialize the connection with the DHT service.
+ *
+ * @param sched scheduler to use
+ * @param cfg configuration to use
+ * @param ht_len size of the internal hash table to use for
+ *               processing multiple GET/FIND requests in parallel
+ *
+ * @return handle to the DHT service, or NULL on error
  */
-void
-get_reply_iterator (void *cls, const struct GNUNET_MessageHeader *reply)
+struct GNUNET_DHT_Handle *
+GNUNET_DHT_connect (struct GNUNET_SCHEDULER_Handle *sched,
+                    const struct GNUNET_CONFIGURATION_Handle *cfg,
+                    unsigned int ht_len)
 {
-  struct GNUNET_DHT_GetHandle *get_handle = cls;
-  struct GNUNET_DHT_GetResultMessage *result;
-  size_t data_size;
-  char *result_data;
-
-  if (ntohs (reply->type) != GNUNET_MESSAGE_TYPE_DHT_GET_RESULT)
-    return;
+  struct GNUNET_DHT_Handle *handle;
 
-  GNUNET_assert (ntohs (reply->size) >=
-                 sizeof (struct GNUNET_DHT_GetResultMessage));
-  result = (struct GNUNET_DHT_GetResultMessage *) reply;
-  data_size = ntohs (result->data_size);
-  GNUNET_assert (ntohs (reply->size) ==
-                 sizeof (struct GNUNET_DHT_GetResultMessage) + data_size);
-  result_data = (char *) &result[1];    /* Set data pointer to end of message */
-
-  get_handle->get_context.iter (get_handle->get_context.iter_cls,
-                                result->expiration, &result->key,
-                                ntohs (result->type), data_size, result_data);
+  handle = GNUNET_malloc (sizeof (struct GNUNET_DHT_Handle));
+  handle->cfg = cfg;
+  handle->sched = sched;
+  handle->uid_gen = GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_WEAK, UINT64_MAX);
+  handle->active_requests = GNUNET_CONTAINER_multihashmap_create (ht_len);
+  if (GNUNET_NO == try_connect (handle))
+    {
+      GNUNET_DHT_disconnect (handle);
+      return NULL;
+    }
+  return handle;
 }
 
 
 /**
- * Iterator called on each result obtained from a generic route
- * operation
+ * Shutdown connection with the DHT service.
+ *
+ * @param handle handle of the DHT connection to stop
  */
 void
-find_peer_reply_iterator (void *cls, const struct GNUNET_MessageHeader *reply)
+GNUNET_DHT_disconnect (struct GNUNET_DHT_Handle *handle)
 {
-  struct GNUNET_DHT_FindPeerHandle *find_peer_handle = cls;
-  struct GNUNET_DHT_FindPeerResultMessage *result;
-  size_t data_size;
-  struct GNUNET_MessageHeader *result_data;
+  struct PendingMessage *pm;
 
-  if (ntohs (reply->type) != GNUNET_MESSAGE_TYPE_DHT_FIND_PEER_RESULT)
-    return;
+  GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size(handle->active_requests));
+  if (handle->th != NULL)
+    {
+      GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
+      handle->th = NULL;
+    }
+  while (NULL != (pm = handle->pending_head))
+    {
+      GNUNET_CONTAINER_DLL_remove (handle->pending_head,
+                                  handle->pending_tail,
+                                  pm);
+      GNUNET_assert (GNUNET_YES == pm->free_on_send);
+      if (GNUNET_SCHEDULER_NO_TASK != pm->timeout_task)
+       GNUNET_SCHEDULER_cancel (handle->sched,
+                                pm->timeout_task);
+      if (NULL != pm->cont)
+       GNUNET_SCHEDULER_add_continuation (handle->sched,
+                                          pm->cont,
+                                          pm->cont_cls,
+                                          GNUNET_SCHEDULER_REASON_TIMEOUT);
+      pm->in_pending_queue = GNUNET_NO;
+      GNUNET_free (pm);
+    }
+  if (handle->client != NULL)
+    {
+      GNUNET_CLIENT_disconnect (handle->client, GNUNET_YES);
+      handle->client = NULL;
+    }  
+  GNUNET_CONTAINER_multihashmap_destroy(handle->active_requests);
+  GNUNET_free (handle);
+}
 
-  GNUNET_assert (ntohs (reply->size) >=
-                 sizeof (struct GNUNET_DHT_FindPeerResultMessage));
-  result = (struct GNUNET_DHT_FindPeerResultMessage *) reply;
-  data_size = ntohs (result->data_size);
-  GNUNET_assert (ntohs (reply->size) ==
-                 sizeof (struct GNUNET_DHT_GetResultMessage) + data_size);
 
-  if (data_size > 0)
-    result_data = (struct GNUNET_MessageHeader *) &result[1];   /* Set data pointer to end of message */
-  else
-    result_data = NULL;
 
-  find_peer_handle->find_peer_context.proc (find_peer_handle->
-                                            find_peer_context.proc_cls,
-                                            &result->peer, result_data);
+
+/* ***** Special low-level API providing generic routing abstraction ***** */
+
+
+/**
+ * Timeout for the transmission of a fire&forget-request.  Clean it up.
+ *
+ * @param cls the 'struct PendingMessage'
+ * @param tc scheduler context
+ */
+static void
+timeout_route_request (void *cls,
+                      const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct PendingMessage *pending = cls;
+  struct GNUNET_DHT_Handle *handle;
+
+  if (pending->free_on_send != GNUNET_YES)
+    {
+      /* timeouts should only apply to fire & forget requests! */
+      GNUNET_break (0);
+      return;
+    }
+  handle = pending->handle;
+  GNUNET_CONTAINER_DLL_remove (handle->pending_head,
+                              handle->pending_tail,
+                              pending);
+  if (pending->cont != NULL)
+    pending->cont (pending->cont_cls,
+                  tc);
+  GNUNET_free (pending);
 }
 
+
 /**
- * Perform an asynchronous FIND_PEER operation on the DHT.
+ * Initiate a generic DHT route operation.
  *
  * @param handle handle to the DHT service
  * @param key the key to look up
@@ -696,387 +650,266 @@ find_peer_reply_iterator (void *cls, const struct GNUNET_MessageHeader *reply)
  * @param iter_cls closure for iter
  * @param timeout when to abort with an error if we fail to get
  *                a confirmation for the request (when necessary) or how long
- *                to wait for tramission to the service
- * @param cont continuation to call when done;
- *             reason will be TIMEOUT on error,
- *             reason will be PREREQ_DONE on success
+ *                to wait for tramission to the service; only applies
+ *                if 'iter' is NULL
+ * @param cont continuation to call when the request has been transmitted
+ *             the first time to the service
  * @param cont_cls closure for cont
- *
  * @return handle to stop the request, NULL if the request is "fire and forget"
  */
 struct GNUNET_DHT_RouteHandle *
 GNUNET_DHT_route_start (struct GNUNET_DHT_Handle *handle,
-                        const GNUNET_HashCode * key,
-                        unsigned int desired_replication_level,
+                        const GNUNET_HashCode *key,
+                        uint32_t desired_replication_level,
                         enum GNUNET_DHT_RouteOption options,
                         const struct GNUNET_MessageHeader *enc,
                         struct GNUNET_TIME_Relative timeout,
                         GNUNET_DHT_ReplyProcessor iter,
                         void *iter_cls,
-                        GNUNET_SCHEDULER_Task cont, void *cont_cls)
+                       GNUNET_SCHEDULER_Task cont,
+                       void *cont_cls)
 {
-  struct GNUNET_DHT_RouteHandle *route_handle;
   struct PendingMessage *pending;
-  struct GNUNET_DHT_Message *message;
-  size_t is_unique;
-  size_t msize;
-  GNUNET_HashCode *uid_key;
-  uint64_t uid;
-
-  is_unique = GNUNET_YES;
-  if (iter == NULL)
-    is_unique = GNUNET_NO;
-
-  route_handle = NULL;
-  uid_key = NULL;
+  struct GNUNET_DHT_RouteMessage *message;
+  struct GNUNET_DHT_RouteHandle *route_handle;
+  uint16_t msize;
+  uint16_t esize;
 
-  do
+  esize = ntohs (enc->size);
+  if (sizeof (struct GNUNET_DHT_RouteMessage) + esize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
     {
-      GNUNET_free_non_null (uid_key);
-      uid = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, -1);
-      uid_key = hash_from_uid (uid);
+      GNUNET_break (0);
+      return NULL;
     }
-  while (GNUNET_CONTAINER_multihashmap_contains
-         (handle->outstanding_requests, uid_key) == GNUNET_YES);
-
-  if (is_unique)
+  msize = sizeof (struct GNUNET_DHT_RouteMessage) + esize;
+  pending = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
+  message = (struct GNUNET_DHT_RouteMessage*) &pending[1];
+  pending->msg = &message->header;
+  pending->handle = handle;
+  pending->cont = cont;
+  pending->cont_cls = cont_cls;
+  
+  message->header.size = htons (msize);
+  message->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE);
+  message->key = *key;
+  message->options = htonl ((uint32_t) options);
+  message->desired_replication_level = htonl (desired_replication_level);
+  handle->uid_gen++;
+  message->unique_id = GNUNET_htonll (handle->uid_gen);
+  memcpy (&message[1], enc, esize);
+
+  if (iter != NULL)
     {
       route_handle = GNUNET_malloc (sizeof (struct GNUNET_DHT_RouteHandle));
-      memcpy (&route_handle->key, key, sizeof (GNUNET_HashCode));
+      route_handle->key = *key;
       route_handle->iter = iter;
       route_handle->iter_cls = iter_cls;
       route_handle->dht_handle = handle;
-      route_handle->uid = uid;
-#if DEBUG_DHT_API
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "`%s': Unique ID is %llu\n", "DHT API", uid);
-#endif
-      /**
-       * Store based on random identifier!
-       */
-      GNUNET_CONTAINER_multihashmap_put (handle->outstanding_requests,
-                                         uid_key, route_handle,
+      route_handle->uid = handle->uid_gen;
+      route_handle->message = pending;
+      GNUNET_CONTAINER_multihashmap_put (handle->active_requests,
+                                         key,
+                                        route_handle,
                                          GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
-      msize = sizeof (struct GNUNET_DHT_Message) + ntohs (enc->size);
-
     }
   else
     {
-      msize = sizeof (struct GNUNET_DHT_Message) + ntohs (enc->size);
+      route_handle = NULL;
+      pending->free_on_send = GNUNET_YES;
+      pending->timeout_task = GNUNET_SCHEDULER_add_delayed (handle->sched,
+                                                           timeout,
+                                                           &timeout_route_request,
+                                                           pending);
     }
-
-  GNUNET_free (uid_key);
-  message = GNUNET_malloc (msize);
-  message->header.size = htons (msize);
-  message->header.type = htons (GNUNET_MESSAGE_TYPE_DHT);
-  memcpy (&message->key, key, sizeof (GNUNET_HashCode));
-  message->options = htons (options);
-  message->desired_replication_level = htons (options);
-  message->unique = htons (is_unique);
-  message->unique_id = GNUNET_htonll (uid);
-  memcpy (&message[1], enc, ntohs (enc->size));
-
-  pending = GNUNET_malloc (sizeof (struct PendingMessage));
-  pending->msg = &message->header;
-  pending->timeout = timeout;
-  pending->cont = cont;
-  pending->cont_cls = cont_cls;
-  pending->is_unique = is_unique;
-  pending->unique_id = uid;
-
-  GNUNET_assert (handle->current == NULL);
-
-  handle->current = pending;
-
-  process_pending_message (handle);
-
+  GNUNET_CONTAINER_DLL_insert (handle->pending_head,
+                              handle->pending_tail,
+                              pending);
+  pending->in_pending_queue = GNUNET_YES;
+  process_pending_messages (handle);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+             "DHT route start request processed, returning %p\n",
+             route_handle);
   return route_handle;
 }
 
-void
-GNUNET_DHT_route_stop (struct GNUNET_DHT_RouteHandle *route_handle,
-                       GNUNET_SCHEDULER_Task cont, void *cont_cls);
-
-/**
- * Perform an asynchronous GET operation on the DHT identified.
- *
- * @param handle handle to the DHT service
- * @param timeout how long to wait for transmission of this request to the service
- * @param type expected type of the response object
- * @param key the key to look up
- * @param iter function to call on each result
- * @param iter_cls closure for iter
- * @param cont continuation to call once message sent
- * @param cont_cls closure for continuation
- *
- * @return handle to stop the async get
- */
-struct GNUNET_DHT_GetHandle *
-GNUNET_DHT_get_start (struct GNUNET_DHT_Handle *handle,
-                      struct GNUNET_TIME_Relative timeout,
-                      uint32_t type,
-                      const GNUNET_HashCode * key,
-                      GNUNET_DHT_GetIterator iter,
-                      void *iter_cls,
-                      GNUNET_SCHEDULER_Task cont, void *cont_cls)
-{
-  struct GNUNET_DHT_GetHandle *get_handle;
-  struct GNUNET_DHT_GetMessage *get_msg;
-
-  if (handle->current != NULL)  /* Can't send right now, we have a pending message... */
-    return NULL;
-
-  get_handle = GNUNET_malloc (sizeof (struct GNUNET_DHT_GetHandle));
-  get_handle->get_context.iter = iter;
-  get_handle->get_context.iter_cls = iter_cls;
-
-#if DEBUG_DHT_API
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Inserting pending get request with key %s\n", "DHT API",
-              GNUNET_h2s (key));
-#endif
-
-  get_msg = GNUNET_malloc (sizeof (struct GNUNET_DHT_GetMessage));
-  get_msg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_GET);
-  get_msg->header.size = htons (sizeof (struct GNUNET_DHT_GetMessage));
-  get_msg->type = htonl (type);
-
-  get_handle->route_handle =
-    GNUNET_DHT_route_start (handle, key, 0, 0, &get_msg->header, timeout,
-                            &get_reply_iterator, get_handle, cont, cont_cls);
-  return get_handle;
-}
 
 /**
  * Stop a previously issued routing request
  *
  * @param route_handle handle to the request to stop
- * @param cont continuation to call once this message is sent to the service or times out
- * @param cont_cls closure for the continuation
- *
  */
 void
-GNUNET_DHT_route_stop (struct GNUNET_DHT_RouteHandle *route_handle,
-                       GNUNET_SCHEDULER_Task cont, void *cont_cls)
+GNUNET_DHT_route_stop (struct GNUNET_DHT_RouteHandle *route_handle)
 {
+  struct GNUNET_DHT_Handle *handle;
   struct PendingMessage *pending;
   struct GNUNET_DHT_StopMessage *message;
   size_t msize;
-  GNUNET_HashCode *uid_key;
-
-  msize = sizeof (struct GNUNET_DHT_StopMessage);
 
-  message = GNUNET_malloc (msize);
-  message->header.size = htons (msize);
-  message->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_STOP);
-#if DEBUG_DHT_API
+  handle = route_handle->dht_handle;
+  if (GNUNET_NO == route_handle->message->in_pending_queue)
+    {
+      /* need to send stop message */
+      msize = sizeof (struct GNUNET_DHT_StopMessage);
+      pending = GNUNET_malloc (sizeof (struct PendingMessage) + 
+                              msize);
+      message = (struct GNUNET_DHT_StopMessage*) &pending[1];
+      pending->msg = &message->header;
+      message->header.size = htons (msize);
+      message->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE_STOP);
+      message->unique_id = GNUNET_htonll (route_handle->uid);
+      message->key = route_handle->key;
+      pending->handle = handle;
+      pending->free_on_send = GNUNET_YES;
+      pending->in_pending_queue = GNUNET_YES;      
+      GNUNET_CONTAINER_DLL_insert (handle->pending_head,
+                                  handle->pending_tail,
+                                  pending);
+      process_pending_messages (handle);
+    }
+  else
+    {
+      /* simply remove pending request from message queue before
+        transmission, no need to transmit STOP request! */
+      GNUNET_CONTAINER_DLL_remove (handle->pending_head,
+                                  handle->pending_tail,
+                                  route_handle->message);
+    }
+  GNUNET_assert (GNUNET_YES ==
+                GNUNET_CONTAINER_multihashmap_remove (route_handle->dht_handle->active_requests,
+                                                      &route_handle->key,
+                                                      route_handle));
+  GNUNET_free(route_handle->message);
+  GNUNET_free(route_handle);
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Remove outstanding request for uid %llu\n", "DHT API",
-              route_handle->uid);
-#endif
-  message->unique_id = GNUNET_htonll (route_handle->uid);
-
-  GNUNET_assert (route_handle->dht_handle->current == NULL);
-
-  pending = GNUNET_malloc (sizeof (struct PendingMessage));
-  pending->msg = (struct GNUNET_MessageHeader *) message;
-  pending->timeout = DEFAULT_DHT_TIMEOUT;
-  pending->cont = cont;
-  pending->cont_cls = cont_cls;
-  pending->is_unique = GNUNET_NO;
-  pending->unique_id = route_handle->uid;
-
-  GNUNET_assert (route_handle->dht_handle->current == NULL);
-
-  route_handle->dht_handle->current = pending;
+             "DHT route stop request processed\n");
+}
 
-  process_pending_message (route_handle->dht_handle);
 
-  uid_key = hash_from_uid (route_handle->uid);
 
-  if (GNUNET_CONTAINER_multihashmap_remove
-      (route_handle->dht_handle->outstanding_requests, uid_key,
-       route_handle) != GNUNET_YES)
-    {
-#if DEBUG_DHT_API
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                  "`%s': Remove outstanding request from hashmap failed for key %s, uid %llu\n",
-                  "DHT API", GNUNET_h2s (uid_key), route_handle->uid);
-#endif
-    }
-  GNUNET_free (uid_key);
-  return;
-}
+/* ***** Special API for controlling DHT routing maintenance ******* */
 
 
 /**
- * Stop async DHT-get.
+ * Send a control message to the DHT.
  *
- * @param get_handle handle to the GET operation to stop
- * @param cont continuation to call once this message is sent to the service or times out
- * @param cont_cls closure for the continuation
+ * @param handle handle to the DHT service
+ * @param command command
+ * @param variable variable to the command
+ * @param cont continuation to call when done (transmitting request to service)
+ * @param cont_cls closure for cont
  */
-void
-GNUNET_DHT_get_stop (struct GNUNET_DHT_GetHandle *get_handle,
-                     GNUNET_SCHEDULER_Task cont, void *cont_cls)
+static void
+send_control_message (struct GNUNET_DHT_Handle *handle,
+                     uint16_t command,
+                     uint16_t variable,
+                     GNUNET_SCHEDULER_Task cont,
+                     void *cont_cls)
 {
-#if DEBUG_DHT_API
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Removing pending get request with key %s, uid %llu\n",
-              "DHT API", GNUNET_h2s (&get_handle->route_handle->key),
-              get_handle->route_handle->uid);
-#endif
-  GNUNET_DHT_route_stop (get_handle->route_handle, cont, cont_cls);
-  GNUNET_free (get_handle);
+  struct GNUNET_DHT_ControlMessage *msg;
+  struct PendingMessage *pending;
 
+  pending = GNUNET_malloc (sizeof (struct PendingMessage) + 
+                          sizeof(struct GNUNET_DHT_ControlMessage)); 
+  msg = (struct GNUNET_DHT_ControlMessage*) &pending[1];
+  pending->msg = &msg->header;
+  msg->header.size = htons (sizeof(struct GNUNET_DHT_ControlMessage));
+  msg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_CONTROL);
+  msg->command = htons (command);
+  msg->variable = htons (variable);
+  pending->free_on_send = GNUNET_YES;
+  pending->cont = cont;
+  pending->cont_cls = cont_cls;
+  pending->in_pending_queue = GNUNET_YES;      
+  GNUNET_CONTAINER_DLL_insert (handle->pending_head,
+                              handle->pending_tail,
+                              pending);
+  process_pending_messages (handle);
 }
 
 
 /**
- * Perform an asynchronous FIND PEER operation on the DHT.
+ * Send a message to the DHT telling it to issue a single find
+ * peer request using the peers unique identifier as key.  This
+ * is used to fill the routing table, and is normally controlled
+ * by the DHT itself.  However, for testing and perhaps more
+ * close control over the DHT, this can be explicitly managed.
  *
  * @param handle handle to the DHT service
- * @param timeout timeout for this request to be sent to the
- *        service
- * @param options routing options for this message
- * @param message a message to inject at found peers (may be null)
- * @param key the key to look up
- * @param proc function to call on each result
- * @param proc_cls closure for proc
- * @param cont continuation to call once message sent
- * @param cont_cls closure for continuation
- *
- * @return handle to stop the async get, NULL on error
+ * @param cont continuation to call when done (transmitting request to service)
+ * @param cont_cls closure for cont
  */
-struct GNUNET_DHT_FindPeerHandle *
-GNUNET_DHT_find_peer_start (struct GNUNET_DHT_Handle *handle,
-                            struct GNUNET_TIME_Relative timeout,
-                            enum GNUNET_DHT_RouteOption options,
-                            struct GNUNET_MessageHeader *message,
-                            const GNUNET_HashCode * key,
-                            GNUNET_DHT_FindPeerProcessor proc,
-                            void *proc_cls,
-                            GNUNET_SCHEDULER_Task cont, void *cont_cls)
+void
+GNUNET_DHT_find_peers (struct GNUNET_DHT_Handle *handle,
+                      GNUNET_SCHEDULER_Task cont,
+                      void *cont_cls)
 {
-  struct GNUNET_DHT_FindPeerHandle *find_peer_handle;
-  struct GNUNET_DHT_FindPeerMessage *find_peer_msg;
-  size_t msize;
-
-  if (handle->current != NULL)  /* Can't send right now, we have a pending message... */
-    return NULL;
-
-  if (message != NULL)
-    msize = ntohs (message->size);
-  else
-    msize = 0;
-
-  find_peer_handle =
-    GNUNET_malloc (sizeof (struct GNUNET_DHT_FindPeerHandle));
-  find_peer_handle->find_peer_context.proc = proc;
-  find_peer_handle->find_peer_context.proc_cls = proc_cls;
-
-#if DEBUG_DHT_API
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Inserting pending `%s' request with key %s\n", "DHT API",
-              "FIND PEER", GNUNET_h2s (key));
-#endif
+  send_control_message (handle,
+                       GNUNET_MESSAGE_TYPE_DHT_FIND_PEER, 0,
+                       cont, cont_cls);
+}
 
-  find_peer_msg =
-    GNUNET_malloc (sizeof (struct GNUNET_DHT_FindPeerMessage) + msize);
-  find_peer_msg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_FIND_PEER);
-  find_peer_msg->header.size =
-    htons (sizeof (struct GNUNET_DHT_FindPeerMessage));
-  find_peer_msg->msg_len = msize;
 
-  if (message != NULL)
-    {
-      memcpy (&find_peer_msg[1], message, msize);
-    }
 
-  find_peer_handle->route_handle =
-    GNUNET_DHT_route_start (handle, key, 0, options, &find_peer_msg->header,
-                            timeout, &find_peer_reply_iterator,
-                            find_peer_handle, cont, cont_cls);
-  return find_peer_handle;
-}
+#if HAVE_MALICIOUS
 
 /**
- * Stop async find peer.  Frees associated resources.
+ * Send a message to the DHT telling it to start issuing random GET
+ * requests every 'frequency' milliseconds.
  *
- * @param find_peer_handle GET operation to stop.
- * @param cont continuation to call once this message is sent to the service or times out
- * @param cont_cls closure for the continuation
+ * @param handle handle to the DHT service
+ * @param frequency delay between sending malicious messages
  */
 void
-GNUNET_DHT_find_peer_stop (struct GNUNET_DHT_FindPeerHandle *find_peer_handle,
-                           GNUNET_SCHEDULER_Task cont, void *cont_cls)
+GNUNET_DHT_set_malicious_getter (struct GNUNET_DHT_Handle *handle,
+                                struct GNUNET_TIME_Relative frequency)
 {
-#if DEBUG_DHT_API
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Removing pending `%s' request with key %s, uid %llu\n",
-              "DHT API", "FIND PEER",
-              GNUNET_h2s (&find_peer_handle->route_handle->key),
-              find_peer_handle->route_handle->uid);
-#endif
-  GNUNET_DHT_route_stop (find_peer_handle->route_handle, cont, cont_cls);
-  GNUNET_free (find_peer_handle);
-
+  if (frequency.value > UINT16_MAX)
+    {
+      GNUNET_break (0);
+      return;
+    }
+  send_control_message (handle,
+                       GNUNET_MESSAGE_TYPE_DHT_MALICIOUS_GET, frequency.value,
+                       NULL, NULL);
 }
 
-
 /**
- * Perform a PUT operation storing data in the DHT.
- *
- * @param h handle to DHT service
- * @param key the key to store under
- * @param type type of the value
- * @param size number of bytes in data; must be less than 64k
- * @param data the data to store
- * @param exp desired expiration time for the value
- * @param cont continuation to call when done;
- *             reason will be TIMEOUT on error,
- *             reason will be PREREQ_DONE on success
- * @param cont_cls closure for cont
+ * Send a message to the DHT telling it to start issuing random PUT
+ * requests every 'frequency' milliseconds.
  *
- * @return GNUNET_YES if put message is queued for transmission
+ * @param handle handle to the DHT service
+ * @param frequency delay between sending malicious messages
  */
-void
-GNUNET_DHT_put (struct GNUNET_DHT_Handle *handle,
-                const GNUNET_HashCode * key,
-                uint32_t type,
-                uint32_t size,
-                const char *data,
-                struct GNUNET_TIME_Absolute exp,
-                struct GNUNET_TIME_Relative timeout,
-                GNUNET_SCHEDULER_Task cont, void *cont_cls)
+void 
+GNUNET_DHT_set_malicious_putter (struct GNUNET_DHT_Handle *handle, 
+                                struct GNUNET_TIME_Relative frequency)
 {
-  struct GNUNET_DHT_PutMessage *put_msg;
-  size_t msize;
-
-  if (handle->current != NULL)
+  if (frequency.value > UINT16_MAX)
     {
-      GNUNET_SCHEDULER_add_continuation (handle->sched, cont, cont_cls,
-                                         GNUNET_SCHEDULER_REASON_TIMEOUT);
+      GNUNET_break (0);
       return;
     }
+  send_control_message (handle,
+                       GNUNET_MESSAGE_TYPE_DHT_MALICIOUS_PUT, frequency.value,
+                       NULL, NULL);
+}
 
-#if DEBUG_DHT_API
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Inserting pending put request with key %s\n", "DHT API",
-              GNUNET_h2s (key));
-#endif
 
-  msize = sizeof (struct GNUNET_DHT_PutMessage) + size;
-  put_msg = GNUNET_malloc (msize);
-  put_msg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_PUT);
-  put_msg->header.size = htons (msize);
-  put_msg->type = htonl (type);
-  put_msg->data_size = htons (size);
-  put_msg->expiration = exp;
-  memcpy (&put_msg[1], data, size);
+/**
+ * Send a message to the DHT telling it to start dropping
+ * all requests received.
+ *
+ * @param handle handle to the DHT service
+ */
+void 
+GNUNET_DHT_set_malicious_dropper (struct GNUNET_DHT_Handle *handle)
+{
+  send_control_message (handle,
+                       GNUNET_MESSAGE_TYPE_DHT_MALICIOUS_DROP, 0,
+                       NULL, NULL);
+}
 
-  GNUNET_DHT_route_start (handle, key, 0, 0, &put_msg->header, timeout, NULL,
-                          NULL, cont, cont_cls);
+#endif
 
-  GNUNET_free (put_msg);
-}
+/* end of dht_api.c */