see if timing is cause
[oweals/gnunet.git] / src / dht / gnunet-service-dht.c
index 613f610ac505c05c90c72f8f827009ab0514f927..77073904f63bcd58d18fca82c17c2cad42a4bfbf 100644 (file)
 #include "gnunet_core_service.h"
 #include "gnunet_signal_lib.h"
 #include "gnunet_util_lib.h"
-#include "gnunet_datastore_service.h"
+#include "gnunet_datacache_lib.h"
+#include "gnunet_transport_service.h"
+#include "gnunet_hello_lib.h"
 #include "dht.h"
 
 /**
- * Handle to the datastore service (for inserting/retrieving data)
+ * Handle to the datacache service (for inserting/retrieving data)
  */
-static struct GNUNET_DATASTORE_Handle *datastore;
+struct GNUNET_DATACACHE_Handle *datacache;
 
 /**
  * The main scheduler to use for the DHT service
@@ -62,38 +64,136 @@ static struct GNUNET_TIME_Relative client_transmit_timeout;
  */
 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;
 
+/**
+ * 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;
 
+
+/**
+ * Linked list of messages to send to clients.
+ */
+struct PendingMessage
+{
+  /**
+   * Pointer to next item in the list
+   */
+  struct PendingMessage *next;
+
+  /**
+   * Actual message to be sent
+   */
+  struct GNUNET_MessageHeader *msg;
+
+};
+
+/**
+ * Struct containing information about a client,
+ * handle to connect to it, and any pending messages
+ * that need to be sent to it.
+ */
 struct ClientList
 {
   /**
-   * This is a linked list
+   * Linked list of active clients
    */
   struct ClientList *next;
 
   /**
-   * The client in question
+   * The handle to this client
+   */
+  struct GNUNET_SERVER_Client *client_handle;
+
+  /**
+   * Handle to the current transmission request, NULL
+   * if none pending.
+   */
+  struct GNUNET_CONNECTION_TransmitHandle *transmit_handle;
+
+  /**
+   * Linked list of pending messages for this client
+   */
+  struct PendingMessage *pending_head;
+
+};
+
+/**
+ * Context for handling results from a get request.
+ */
+struct DatacacheGetContext
+{
+  /**
+   * The client to send the result to.
+   */
+  struct ClientList *client;
+
+  /**
+   * The unique id of this request
+   */
+  unsigned long long unique_id;
+};
+
+/**
+ * Context containing information about a DHT message received.
+ */
+struct DHT_MessageContext
+{
+  /**
+   * The client this request was received from.
+   */
+  struct ClientList *client;
+
+  /**
+   * The key this request was about
+   */
+  GNUNET_HashCode *key;
+
+  /**
+   * The unique identifier of this request
+   */
+  unsigned long long unique_id;
+
+  /**
+   * Desired replication level
    */
-  struct GNUNET_SERVER_Client *client;
+  size_t replication;
+
+  /**
+   * Any message options for this request
+   */
+  size_t msg_options;
 };
 
 /**
- * Server handler for handling locally received dht requests
+ * List of active clients.
+ */
+static struct ClientList *client_list;
+
+
+/**
+ * Server handlers for handling locally received dht requests
  */
 static void
-handle_dht_start_message(void *cls, struct GNUNET_SERVER_Client * client,
-                         const struct GNUNET_MessageHeader *message);
+handle_dht_start_message (void *cls, struct GNUNET_SERVER_Client *client,
+                          const struct GNUNET_MessageHeader *message);
 
 static void
-handle_dht_stop_message(void *cls, struct GNUNET_SERVER_Client * client,
+handle_dht_stop_message (void *cls, struct GNUNET_SERVER_Client *client,
                          const struct GNUNET_MessageHeader *message);
 
 static struct GNUNET_SERVER_MessageHandler plugin_handlers[] = {
@@ -107,28 +207,29 @@ static struct GNUNET_SERVER_MessageHandler plugin_handlers[] = {
  * Core handler for p2p dht get requests.
  */
 static int handle_dht_p2p_get (void *cls,
-                             const struct GNUNET_PeerIdentity * peer,
-                             const struct GNUNET_MessageHeader * message,
-                             struct GNUNET_TIME_Relative latency,
-                             uint32_t distance);
+                               const struct GNUNET_PeerIdentity *peer,
+                               const struct GNUNET_MessageHeader *message,
+                               struct GNUNET_TIME_Relative latency,
+                               uint32_t distance);
 
 /**
  * Core handler for p2p dht put requests.
  */
 static int handle_dht_p2p_put (void *cls,
-                             const struct GNUNET_PeerIdentity * peer,
-                             const struct GNUNET_MessageHeader * message,
-                             struct GNUNET_TIME_Relative latency,
-                             uint32_t distance);
+                               const struct GNUNET_PeerIdentity *peer,
+                               const struct GNUNET_MessageHeader *message,
+                               struct GNUNET_TIME_Relative latency,
+                               uint32_t distance);
 
 /**
  * Core handler for p2p dht find peer requests.
  */
 static int handle_dht_p2p_find_peer (void *cls,
-                             const struct GNUNET_PeerIdentity * peer,
-                             const struct GNUNET_MessageHeader * message,
-                             struct GNUNET_TIME_Relative latency,
-                             uint32_t distance);
+                                     const struct GNUNET_PeerIdentity *peer,
+                                     const struct GNUNET_MessageHeader
+                                     *message,
+                                     struct GNUNET_TIME_Relative latency,
+                                     uint32_t distance);
 
 static struct GNUNET_CORE_MessageHandler core_handlers[] = {
   {&handle_dht_p2p_get, GNUNET_MESSAGE_TYPE_DHT_GET, 0},
@@ -137,205 +238,547 @@ static struct GNUNET_CORE_MessageHandler core_handlers[] = {
   {NULL, 0, 0}
 };
 
+/**
+ * Forward declaration.
+ */
+static size_t send_generic_reply (void *cls, size_t size, void *buf);
+
+/**
+ * Task run to check for messages that need to be sent to a client.
+ *
+ * @param cls a ClientList, containing the client and any messages to be sent to it
+ * @param tc reason this was called
+ */
+static void
+process_pending_messages (void *cls,
+                          const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct ClientList *client = cls;
+
+  if (client->pending_head == NULL)     /* No messages queued */
+    {
+#if DEBUG_DHT
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "`%s': Have no pending messages for client.\n", "DHT");
+#endif
+      return;
+    }
+
+  if (client->transmit_handle == NULL)  /* No current pending messages, we can try to send! */
+    client->transmit_handle =
+      GNUNET_SERVER_notify_transmit_ready (client->client_handle,
+                                           ntohs (client->pending_head->msg->
+                                                  size),
+                                           GNUNET_TIME_relative_multiply
+                                           (GNUNET_TIME_UNIT_SECONDS, 5),
+                                           &send_generic_reply, client);
+  else
+    {
+#if DEBUG_DHT
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "`%s': Transmit handle is non-null.\n", "DHT");
+#endif
+    }
+}
+
+/**
+ * Callback called as a result of issuing a GNUNET_SERVER_notify_transmit_ready
+ * request.  A ClientList is passed as closure, take the head of the list
+ * and copy it into buf, which has the result of sending the message to the
+ * client.
+ *
+ * @param cls closure to this call
+ * @param size maximum number of bytes available to send
+ * @param buf where to copy the actual message to
+ *
+ * @return the number of bytes actually copied, 0 indicates failure
+ */
+static size_t
+send_generic_reply (void *cls, size_t size, void *buf)
+{
+  struct ClientList *client = cls;
+  struct PendingMessage *reply = client->pending_head;
+  int ret;
+
+  client->transmit_handle = NULL;
+  if (buf == NULL)              /* Message timed out, that's crappy... */
+    {
+#if DEBUG_DHT
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s': buffer was NULL\n", "DHT");
+#endif
+      client->pending_head = reply->next;
+      GNUNET_free (reply->msg);
+      GNUNET_free (reply);
+      return 0;
+    }
+
+  if (size >= ntohs (reply->msg->size))
+    {
+#if DEBUG_DHT
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "`%s': Copying reply to buffer, REALLY SENT\n", "DHT");
+#endif
+      memcpy (buf, reply->msg, ntohs (reply->msg->size));
+
+      ret = ntohs (reply->msg->size);
+    }
+  else
+    ret = 0;
+
+  client->pending_head = reply->next;
+  GNUNET_free (reply->msg);
+  GNUNET_free (reply);
+
+  GNUNET_SCHEDULER_add_now (sched, &process_pending_messages, client);
+  return ret;
+}
+
+/**
+ * Add a PendingMessage to the clients list of messages to be sent
+ *
+ * @param client the active client to send the message to
+ * @param pending_message the actual message to send
+ */
+static void
+add_pending_message (struct ClientList *client,
+                     struct PendingMessage *pending_message)
+{
+  struct PendingMessage *pos;
+  struct PendingMessage *prev;
+
+  pos = client->pending_head;
+
+#if DEBUG_DHT
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "`%s': Adding pending message for client.\n", "DHT");
+#endif
+
+  if (pos == NULL)
+    {
+      client->pending_head = pending_message;
+    }
+  else                          /* This means another request is already queued, rely on send_reply to process all pending messages */
+    {
+      while (pos != NULL)       /* Find end of list */
+        {
+          prev = pos;
+          pos = pos->next;
+        }
+
+      GNUNET_assert (prev != NULL);
+      prev->next = pending_message;
+    }
+
+  GNUNET_SCHEDULER_add_now (sched, &process_pending_messages, client);
+
+}
+
+/**
+ * Called when a reply needs to be sent to a client, either as
+ * a result it found to a GET or FIND PEER request.
+ *
+ * @param client the client to send the reply to
+ * @param message the encapsulated message to send
+ * @param uid the unique identifier of this request
+ */
+static void
+send_reply_to_client (struct ClientList *client,
+                      struct GNUNET_MessageHeader *message,
+                      unsigned long long uid)
+{
+  struct GNUNET_DHT_Message *reply;
+  struct PendingMessage *pending_message;
+
+  size_t msize;
+  size_t tsize;
+#if DEBUG_DHT
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "`%s': Sending reply to client.\n", "DHT");
+#endif
+  msize = ntohs (message->size);
+  tsize = sizeof (struct GNUNET_DHT_Message) + msize;
+  reply = GNUNET_malloc (tsize);
+  reply->header.type = htons (GNUNET_MESSAGE_TYPE_DHT);
+  reply->header.size = htons (tsize);
+  if (uid != 0)
+    reply->unique = htons (GNUNET_YES);
+  reply->unique_id = GNUNET_htonll (uid);
+  memcpy (&reply[1], message, msize);
+
+  pending_message = GNUNET_malloc (sizeof (struct PendingMessage));
+  pending_message->msg = &reply->header;
+
+  add_pending_message (client, pending_message);
+}
 
 
+/**
+ * Iterator for local get request results,
+ *
+ * @param cls closure for iterator, a DatacacheGetContext
+ * @param exp when does this value expire?
+ * @param key the key this data is stored under
+ * @param size the size of the data identified by key
+ * @param data the actual data
+ * @param type the type of the data
+ *
+ * @return GNUNET_OK to continue iteration, anything else
+ * to stop iteration.
+ */
+static int
+datacache_get_iterator (void *cls,
+                        struct GNUNET_TIME_Absolute exp,
+                        const GNUNET_HashCode * key,
+                        uint32_t size, const char *data, uint32_t type)
+{
+  struct DatacacheGetContext *datacache_get_ctx = cls;
+  struct GNUNET_DHT_GetResultMessage *get_result;
+#if DEBUG_DHT
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "`%s': Received `%s' response from datacache\n", "DHT", "GET");
+#endif
+  get_result =
+    GNUNET_malloc (sizeof (struct GNUNET_DHT_GetResultMessage) + size);
+  get_result->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_GET_RESULT);
+  get_result->header.size =
+    htons (sizeof (struct GNUNET_DHT_GetResultMessage) + size);
+  get_result->data_size = htons (size);
+  get_result->expiration = exp;
+  memcpy (&get_result->key, key, sizeof (GNUNET_HashCode));
+  get_result->type = htons (type);
+  memcpy (&get_result[1], data, size);
+
+  send_reply_to_client (datacache_get_ctx->client, &get_result->header,
+                        datacache_get_ctx->unique_id);
+
+  GNUNET_free (get_result);
+  return GNUNET_OK;
+}
+
 /**
  * Server handler for initiating local dht get requests
+ *
+ * @param cls closure for service
+ * @param get_msg the actual get message
+ * @param message_context struct containing pertinent information about the get request
+ *
  */
-static void handle_dht_get (void *cls, struct GNUNET_DHT_GetMessage *get_msg, GNUNET_HashCode *key)
+static void
+handle_dht_get (void *cls, struct GNUNET_DHT_GetMessage *get_msg,
+                struct DHT_MessageContext *message_context)
 {
+#if DEBUG_DHT
   GNUNET_HashCode get_key;
+#endif
   size_t get_type;
+  unsigned int results;
+  struct DatacacheGetContext *datacache_get_context;
 
-  GNUNET_assert(ntohs(get_msg->header.size) >= sizeof(struct GNUNET_DHT_GetMessage));
-  get_type = ntohs(get_msg->type);
+  GNUNET_assert (ntohs (get_msg->header.size) >=
+                 sizeof (struct GNUNET_DHT_GetMessage));
+  get_type = ntohs (get_msg->type);
 
 #if DEBUG_DHT
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Received `%s' request from client, message type %d, key %s\n", "DHT", "GET", get_type, GNUNET_h2s(&get_key));
+              "`%s': Received `%s' request from client, message type %d, key %s, uid %llu\n",
+              "DHT", "GET", get_type, GNUNET_h2s (&get_key),
+              message_context->unique_id);
 #endif
 
+  datacache_get_context = GNUNET_malloc (sizeof (struct DatacacheGetContext));
+  datacache_get_context->client = message_context->client;
+  datacache_get_context->unique_id = message_context->unique_id;
+
+  results = 0;
+  if (datacache != NULL)
+    results =
+      GNUNET_DATACACHE_get (datacache, message_context->key, get_type,
+                            &datacache_get_iterator, datacache_get_context);
+
+#if DEBUG_DHT
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "`%s': Found %d results for local `%s' request\n", "DHT",
+              results, "GET");
+#endif
+  GNUNET_free (datacache_get_context);
   /* FIXME: Implement get functionality here */
 }
 
 
 /**
  * Server handler for initiating local dht find peer requests
+ *
+ * @param cls closure for service
+ * @param find_msg the actual find peer message
+ * @param message_context struct containing pertinent information about the request
+ *
  */
-static void handle_dht_find_peer (void *cls, struct GNUNET_DHT_FindPeerMessage *find_msg, GNUNET_HashCode *key)
+static void
+handle_dht_find_peer (void *cls, struct GNUNET_DHT_FindPeerMessage *find_msg,
+                      struct DHT_MessageContext *message_context)
 {
+  struct GNUNET_DHT_FindPeerResultMessage *find_peer_result;
+  size_t hello_size;
+  size_t tsize;
+#if DEBUG_DHT
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "`%s': Received `%s' request from client, key %s (msg size %d, we expected %d)\n",
+              "DHT", "FIND PEER", GNUNET_h2s (message_context->key),
+              ntohs (find_msg->header.size),
+              sizeof (struct GNUNET_DHT_FindPeerMessage));
+#endif
 
-  GNUNET_assert(ntohs(find_msg->header.size) == sizeof(struct GNUNET_DHT_FindPeerMessage));
+  GNUNET_assert (ntohs (find_msg->header.size) >=
+                 sizeof (struct GNUNET_DHT_FindPeerMessage));
 
+  if (my_hello == NULL)
+  {
 #if DEBUG_DHT
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Received `%s' request from client, key %s\n", "DHT", "FIND PEER", GNUNET_h2s(key));
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "`%s': Our HELLO is null, can't return.\n",
+                "DHT");
 #endif
 
+    return;
+  }
+
+  /* Simplistic find_peer functionality, always return our hello */
+  hello_size = ntohs(my_hello->size);
+  tsize = hello_size + sizeof (struct GNUNET_DHT_FindPeerResultMessage);
+  find_peer_result = GNUNET_malloc (tsize);
+  find_peer_result->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_FIND_PEER_RESULT);
+  find_peer_result->header.size = htons (tsize);
+  find_peer_result->data_size = htons (hello_size);
+  memcpy(&find_peer_result->peer, &my_identity, sizeof(struct GNUNET_PeerIdentity));
+  memcpy (&find_peer_result[1], &my_hello, hello_size);
+
+  send_reply_to_client(message_context->client, &find_peer_result->header, message_context->unique_id);
+  GNUNET_free(find_peer_result);
   /* FIXME: Implement find peer functionality here */
 }
 
 
 /**
  * Server handler for initiating local dht put requests
+ *
+ * @param cls closure for service
+ * @param put_msg the actual put message
+ * @param message_context struct containing pertinent information about the request
  */
-static void handle_dht_put (void *cls, struct GNUNET_DHT_PutMessage *put_msg, GNUNET_HashCode *key)
+static void
+handle_dht_put (void *cls, struct GNUNET_DHT_PutMessage *put_msg,
+                struct DHT_MessageContext *message_context)
 {
   size_t put_type;
   size_t data_size;
-  char *data;
 
-  GNUNET_assert(ntohs(put_msg->header.size) >= sizeof(struct GNUNET_DHT_PutMessage));
+  GNUNET_assert (ntohs (put_msg->header.size) >=
+                 sizeof (struct GNUNET_DHT_PutMessage));
 
-  put_type = ntohs(put_msg->type);
-  data_size = ntohs(put_msg->data_size);
+  put_type = ntohs (put_msg->type);
+  data_size = ntohs (put_msg->data_size);
 #if DEBUG_DHT
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': %s msg total size is %d, data size %d, struct size %d\n", "DHT", "PUT", ntohs(put_msg->header.size), data_size, sizeof(struct GNUNET_DHT_PutMessage));
+              "`%s': %s msg total size is %d, data size %d, struct size %d\n",
+              "DHT", "PUT", ntohs (put_msg->header.size), data_size,
+              sizeof (struct GNUNET_DHT_PutMessage));
 #endif
-  GNUNET_assert(ntohs(put_msg->header.size) == sizeof(struct GNUNET_DHT_PutMessage) + data_size);
-  data = GNUNET_malloc(data_size);
-  memcpy(data, &put_msg[1], data_size);
+  GNUNET_assert (ntohs (put_msg->header.size) ==
+                 sizeof (struct GNUNET_DHT_PutMessage) + data_size);
 
 #if DEBUG_DHT
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Received `%s' request from client, message type %d, key %s\n", "DHT", "PUT", put_type, GNUNET_h2s(key));
+              "`%s': Received `%s' request from client, message type %d, key %s\n",
+              "DHT", "PUT", put_type, GNUNET_h2s (message_context->key));
 #endif
 
-
+  /**
+   * Simplest DHT functionality, store any message we receive a put request for.
+   */
+  if (datacache != NULL)
+    GNUNET_DATACACHE_put (datacache, message_context->key, data_size,
+                          (char *) &put_msg[1], put_type,
+                          put_msg->expiration);
   /**
    * FIXME: Implement dht put request functionality here!
    */
 
-  GNUNET_free(data);
 }
 
+
 /**
- * Context for sending receipt confirmations. Not used yet.
+ * Find a client if it exists, add it otherwise.
+ *
+ * @param client the server handle to the client
+ *
+ * @return the client if found, a new client otherwise
  */
-struct SendConfirmationContext
+static struct ClientList *
+find_active_client (struct GNUNET_SERVER_Client *client)
 {
-  /**
-   * The message to send.
-   */
-  struct GNUNET_DHT_StopMessage *message;
+  struct ClientList *pos = client_list;
+  struct ClientList *ret;
 
-  /**
-   * Transmit handle.
-   */
-  struct GNUNET_CONNECTION_TransmitHandle * transmit_handle;
-};
+  while (pos != NULL)
+    {
+      if (pos->client_handle == client)
+        return pos;
+      pos = pos->next;
+    }
 
-static size_t send_confirmation (void *cls,
-                          size_t size, void *buf)
-{
-  struct GNUNET_DHT_StopMessage *confirmation_message = cls;
+  ret = GNUNET_malloc (sizeof (struct ClientList));
+  ret->client_handle = client;
+  ret->next = client_list;
+  client_list = ret;
+  ret->pending_head = NULL;
 
-  if (buf == NULL) /* Message timed out, that's crappy... */
-  {
-    GNUNET_free(confirmation_message);
-    return 0;
-  }
-
-  if (size >= ntohs(confirmation_message->header.size))
-  {
-    memcpy(buf, confirmation_message, ntohs(confirmation_message->header.size));
-    return ntohs(confirmation_message->header.size);
-  }
-  else
-    return 0;
+  return ret;
 }
 
+/**
+ * Construct a message receipt confirmation for a particular uid.
+ * Receipt confirmations are used for any requests that don't expect
+ * a reply otherwise (i.e. put requests, stop requests).
+ *
+ * @param client the handle for the client
+ * @param uid the unique identifier of this message
+ */
 static void
-send_client_receipt_confirmation(struct GNUNET_SERVER_Client *client, uint64_t uid)
+send_client_receipt_confirmation (struct GNUNET_SERVER_Client *client,
+                                  uint64_t uid)
 {
   struct GNUNET_DHT_StopMessage *confirm_message;
+  struct ClientList *active_client;
+  struct PendingMessage *pending_message;
 
 #if DEBUG_DHT
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Sending receipt confirmation for uid %llu\n", "DHT", uid);
+              "`%s': Sending receipt confirmation for uid %llu\n", "DHT",
+              uid);
 #endif
-  confirm_message = GNUNET_malloc(sizeof(struct GNUNET_DHT_StopMessage));
-  confirm_message->header.type = htons(GNUNET_MESSAGE_TYPE_DHT_STOP);
-  confirm_message->header.size = htons(sizeof(struct GNUNET_DHT_StopMessage));
-  confirm_message->unique_id = GNUNET_htonll(uid);
+  confirm_message = GNUNET_malloc (sizeof (struct GNUNET_DHT_StopMessage));
+  confirm_message->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_STOP);
+  confirm_message->header.size =
+    htons (sizeof (struct GNUNET_DHT_StopMessage));
+  confirm_message->unique_id = GNUNET_htonll (uid);
 
-  GNUNET_SERVER_notify_transmit_ready (client,
-                                       sizeof(struct GNUNET_DHT_StopMessage),
-                                       GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5),
-                                       &send_confirmation, confirm_message);
+  active_client = find_active_client (client);
+  pending_message = GNUNET_malloc (sizeof (struct PendingMessage));
+  pending_message->msg = &confirm_message->header;
+
+  add_pending_message (active_client, pending_message);
 
 }
 
+/**
+ * Handler for any generic DHT messages, calls the appropriate handler
+ * depending on message type, sends confirmation if responses aren't otherwise
+ * expected.
+ *
+ * @param cls closure for the service
+ * @param client the client we received this message from
+ * @param message the actual message received
+ */
 static void
-handle_dht_start_message(void *cls, struct GNUNET_SERVER_Client * client,
-                         const struct GNUNET_MessageHeader *message)
+handle_dht_start_message (void *cls, struct GNUNET_SERVER_Client *client,
+                          const struct GNUNET_MessageHeader *message)
 {
-  struct GNUNET_DHT_Message *dht_msg = (struct GNUNET_DHT_Message *)message;
+  struct GNUNET_DHT_Message *dht_msg = (struct GNUNET_DHT_Message *) message;
   struct GNUNET_MessageHeader *enc_msg;
+  struct DHT_MessageContext *message_context;
+
   size_t enc_type;
 
-  enc_msg = (struct GNUNET_MessageHeader *)&dht_msg[1];
-  enc_type = ntohs(enc_msg->type);
+  enc_msg = (struct GNUNET_MessageHeader *) &dht_msg[1];
+  enc_type = ntohs (enc_msg->type);
 
 
 #if DEBUG_DHT
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Received `%s' request from client, message type %d, key %s, uid %llu\n", "DHT", "GENERIC", enc_type, GNUNET_h2s(&dht_msg->key), GNUNET_ntohll(dht_msg->unique_id));
+              "`%s': Received `%s' request from client, message type %d, key %s, uid %llu\n",
+              "DHT", "GENERIC", enc_type, GNUNET_h2s (&dht_msg->key),
+              GNUNET_ntohll (dht_msg->unique_id));
 #endif
 
-  /* FIXME: Implement demultiplexing functionality here */
+  message_context = GNUNET_malloc (sizeof (struct DHT_MessageContext));
+  message_context->client = find_active_client (client);
+  message_context->key = &dht_msg->key;
+  message_context->unique_id = GNUNET_ntohll (dht_msg->unique_id);
+  message_context->replication = ntohs (dht_msg->desired_replication_level);
+  message_context->msg_options = ntohs (dht_msg->options);
+
   switch (enc_type)
     {
     case GNUNET_MESSAGE_TYPE_DHT_GET:
-      handle_dht_get(cls, (struct GNUNET_DHT_GetMessage *)enc_msg, &dht_msg->key);
+      handle_dht_get (cls, (struct GNUNET_DHT_GetMessage *) enc_msg,
+                      message_context);
       break;
     case GNUNET_MESSAGE_TYPE_DHT_PUT:
-      handle_dht_put(cls, (struct GNUNET_DHT_PutMessage *)enc_msg, &dht_msg->key);
-      send_client_receipt_confirmation(client, GNUNET_ntohll(dht_msg->unique_id));
+      handle_dht_put (cls, (struct GNUNET_DHT_PutMessage *) enc_msg,
+                      message_context);
+      send_client_receipt_confirmation (client,
+                                        GNUNET_ntohll (dht_msg->unique_id));
       break;
     case GNUNET_MESSAGE_TYPE_DHT_FIND_PEER:
-      handle_dht_find_peer(cls, (struct GNUNET_DHT_FindPeerMessage *)enc_msg, &dht_msg->key);
+      handle_dht_find_peer (cls,
+                            (struct GNUNET_DHT_FindPeerMessage *) enc_msg,
+                            message_context);
       break;
     default:
-#if DEBUG_DHT
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                   "`%s': Message type (%d) not handled\n", "DHT", enc_type);
-#endif
     }
 
-  GNUNET_SERVER_receive_done(client, GNUNET_OK);
+  GNUNET_free (message_context);
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
 
 }
 
-
+/**
+ * Handler for any generic DHT stop messages, calls the appropriate handler
+ * depending on message type, sends confirmation by default (stop messages
+ * do not otherwise expect replies)
+ *
+ * @param cls closure for the service
+ * @param client the client we received this message from
+ * @param message the actual message received
+ *
+ * TODO: add demultiplexing for stop message types.
+ */
 static void
-handle_dht_stop_message(void *cls, struct GNUNET_SERVER_Client * client,
-                        const struct GNUNET_MessageHeader *message)
+handle_dht_stop_message (void *cls, struct GNUNET_SERVER_Client *client,
+                         const struct GNUNET_MessageHeader *message)
 {
-  struct GNUNET_DHT_StopMessage * dht_stop_msg = (struct GNUNET_DHT_StopMessage *)message;
+  struct GNUNET_DHT_StopMessage *dht_stop_msg =
+    (struct GNUNET_DHT_StopMessage *) message;
 
 #if DEBUG_DHT
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Received `%s' request from client, uid %llu\n", "DHT", "GENERIC STOP", GNUNET_ntohll(dht_stop_msg->unique_id));
+              "`%s': Received `%s' request from client, uid %llu\n", "DHT",
+              "GENERIC STOP", GNUNET_ntohll (dht_stop_msg->unique_id));
 #endif
-  send_client_receipt_confirmation(client, GNUNET_ntohll(dht_stop_msg->unique_id));
-  GNUNET_SERVER_receive_done(client, GNUNET_OK);
+
+  /* TODO: Put in demultiplexing here */
+
+  send_client_receipt_confirmation (client,
+                                    GNUNET_ntohll (dht_stop_msg->unique_id));
+  GNUNET_SERVER_receive_done (client, GNUNET_OK);
 }
 
 
 /**
  * Core handler for p2p dht get requests.
  */
-static int handle_dht_p2p_get (void *cls,
-                               const struct GNUNET_PeerIdentity * peer,
-                               const struct GNUNET_MessageHeader * message,
-                               struct GNUNET_TIME_Relative latency,
-                               uint32_t distance)
+static int
+handle_dht_p2p_get (void *cls,
+                    const struct GNUNET_PeerIdentity *peer,
+                    const struct GNUNET_MessageHeader *message,
+                    struct GNUNET_TIME_Relative latency, uint32_t distance)
 {
 #if DEBUG_DHT
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Received `%s' request from another peer\n", "DHT", "GET");
+              "`%s': Received `%s' request from another peer\n", "DHT",
+              "GET");
 #endif
 
   return GNUNET_YES;
@@ -344,15 +787,16 @@ static int handle_dht_p2p_get (void *cls,
 /**
  * Core handler for p2p dht put requests.
  */
-static int handle_dht_p2p_put (void *cls,
-                             const struct GNUNET_PeerIdentity * peer,
-                             const struct GNUNET_MessageHeader * message,
-                             struct GNUNET_TIME_Relative latency,
-                             uint32_t distance)
+static int
+handle_dht_p2p_put (void *cls,
+                    const struct GNUNET_PeerIdentity *peer,
+                    const struct GNUNET_MessageHeader *message,
+                    struct GNUNET_TIME_Relative latency, uint32_t distance)
 {
 #if DEBUG_DHT
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Received `%s' request from another peer\n", "DHT", "PUT");
+              "`%s': Received `%s' request from another peer\n", "DHT",
+              "PUT");
 #endif
 
   return GNUNET_YES;
@@ -361,20 +805,45 @@ static int handle_dht_p2p_put (void *cls,
 /**
  * Core handler for p2p dht find peer requests.
  */
-static int handle_dht_p2p_find_peer (void *cls,
-                             const struct GNUNET_PeerIdentity * peer,
-                             const struct GNUNET_MessageHeader * message,
-                             struct GNUNET_TIME_Relative latency,
-                             uint32_t distance)
+static int
+handle_dht_p2p_find_peer (void *cls,
+                          const struct GNUNET_PeerIdentity *peer,
+                          const struct GNUNET_MessageHeader *message,
+                          struct GNUNET_TIME_Relative latency,
+                          uint32_t distance)
 {
 #if DEBUG_DHT
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "`%s': Received `%s' request from another peer\n", "DHT", "FIND PEER");
+              "`%s': Received `%s' request from another peer\n", "DHT",
+              "FIND PEER");
 #endif
 
   return GNUNET_YES;
 }
 
+
+/**
+ * Receive the HELLO from transport service,
+ * free current and replace if necessary.
+ *
+ * @param cls NULL
+ * @param message HELLO message of peer
+ */
+static void
+process_hello (void *cls, const struct GNUNET_MessageHeader *message)
+{
+#if DEBUG_DHT
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Received our `%s' from transport service\n",
+              "HELLO");
+#endif
+
+  GNUNET_assert (message != NULL);
+  GNUNET_free_non_null(my_hello);
+  my_hello = GNUNET_malloc(ntohs(message->size));
+  memcpy(my_hello, message, ntohs(message->size));
+}
+
 /**
  * Task run during shutdown.
  *
@@ -382,35 +851,57 @@ static int handle_dht_p2p_find_peer (void *cls,
  * @param tc unused
  */
 static void
-shutdown_task (void *cls,
-               const struct GNUNET_SCHEDULER_TaskContext *tc)
+shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 {
-  GNUNET_CORE_disconnect (coreAPI);
+  if (transport_handle != NULL)
+  {
+    GNUNET_free_non_null(my_hello);
+    GNUNET_TRANSPORT_get_hello_cancel(transport_handle, &process_hello, NULL);
+    GNUNET_TRANSPORT_disconnect(transport_handle);
+  }
+  if (coreAPI != NULL)
+    GNUNET_CORE_disconnect (coreAPI);
 }
 
+
 /**
  * To be called on core init/fail.
+ *
+ * @param cls service closure
+ * @param server handle to the server for this service
+ * @param identity the public identity of this peer
+ * @param publicKey the public key of this peer
  */
-void core_init (void *cls,
-                struct GNUNET_CORE_Handle * server,
-                const struct GNUNET_PeerIdentity *identity,
-                const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded * publicKey)
+void
+core_init (void *cls,
+           struct GNUNET_CORE_Handle *server,
+           const struct GNUNET_PeerIdentity *identity,
+           const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *publicKey)
 {
 
   if (server == NULL)
     {
-      GNUNET_SCHEDULER_cancel(sched, cleanup_task);
-      GNUNET_SCHEDULER_add_now(sched, &shutdown_task, NULL);
+#if DEBUG_DHT
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "%s: Connection to core FAILED!\n", "dht",
+              GNUNET_i2s (identity));
+#endif
+      GNUNET_SCHEDULER_cancel (sched, cleanup_task);
+      GNUNET_SCHEDULER_add_now (sched, &shutdown_task, NULL);
       return;
     }
 #if DEBUG_DHT
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "%s: Core connection initialized, I am peer: %s\n", "dht", GNUNET_i2s(identity));
+              "%s: Core connection initialized, I am peer: %s\n", "dht",
+              GNUNET_i2s (identity));
 #endif
-  memcpy(&my_identity, identity, sizeof(struct GNUNET_PeerIdentity));
+  /* Copy our identity so we can use it */
+  memcpy (&my_identity, identity, sizeof (struct GNUNET_PeerIdentity));
+  /* Set the server to local variable */
   coreAPI = server;
 }
 
+
 /**
  * Process dht requests.
  *
@@ -428,34 +919,41 @@ run (void *cls,
   sched = scheduler;
   cfg = c;
 
-  datastore = GNUNET_DATASTORE_connect(c, scheduler);
+  datacache = GNUNET_DATACACHE_create (sched, cfg, "dhtcache");
 
-  client_transmit_timeout = GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 5);
+  client_transmit_timeout =
+    GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5);
   GNUNET_SERVER_add_handlers (server, plugin_handlers);
 
-  coreAPI =
-  GNUNET_CORE_connect (sched, /* Main scheduler */
-                       cfg,   /* Main configuration */
-                       client_transmit_timeout, /* Delay for connecting */
-                       NULL, /* FIXME: anything we want to pass around? */
-                       &core_init, /* Call core_init once connected */
-                       NULL, /* Don't care about pre-connects */
-                       NULL, /* Don't care about connects */
-                       NULL, /* Don't care about disconnects */
-                       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 */
+  coreAPI = GNUNET_CORE_connect (sched, /* Main scheduler */
+                                 cfg,   /* Main configuration */
+                                 client_transmit_timeout,       /* Delay for connecting */
+                                 NULL,  /* FIXME: anything we want to pass around? */
+                                 &core_init,    /* Call core_init once connected */
+                                 NULL,  /* Don't care about pre-connects */
+                                 NULL,  /* Don't care about connects */
+                                 NULL,  /* Don't care about disconnects */
+                                 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 */
+
+  transport_handle = GNUNET_TRANSPORT_connect(sched, cfg, NULL, NULL, NULL, NULL);
+
+  if (transport_handle != NULL)
+    GNUNET_TRANSPORT_get_hello (transport_handle, &process_hello, NULL);
+  else
+    GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Failed to connect to transport service!\n");
+
 
   if (coreAPI == NULL)
     return;
 
   /* Scheduled the task to clean up when shutdown is called */
   cleanup_task = GNUNET_SCHEDULER_add_delayed (sched,
-                                GNUNET_TIME_UNIT_FOREVER_REL,
-                                &shutdown_task,
-                                NULL);
+                                               GNUNET_TIME_UNIT_FOREVER_REL,
+                                               &shutdown_task, NULL);
 }