2008-02-01 Tatsuhiro Tsujikawa <tujikawa at rednoah dot com>

	Added DHT functionality, compatible with mainline.
	DHT is disabled by default. To enable it, give --enable-dht to 
aria2c.
	You may need to specify entry point to DHT network using
	--dht-entry-point. DHT uses UDP port to listen incoming message.
	Use --dht-listen-port to specify port number. Make sure that 
your
	firewall configuration can pass through UDP traffic to the port.
	The routing table is saved in $HOME/.aria2/dht.dat.
	* src/DHT*
	* src/BNode.{h, cc}
	* src/PeerInteractionCommand.cc: enable DHT functionality for a
	particular torrent.
	* src/Data.cc: Rewritten ctor.
	* src/OptionHandlerFactory.cc: Added --enable-dht, 
--dht-listen-port,
	--dht-entry-point.
	* src/DefaultBtInteractive.cc: Send port message if dht is 
enabled.
	* src/RequestGroup.cc: Initialize DHT functionality. When 
download
	ends, remove BtContext from DHTPeerAnnounceStorage.
	* src/BtPortMessage.{h, cc}: Rewritten.
	* src/message.h
	* src/OptionHandlerImpl.cc
	* src/option_processing.cc: Added --enable-dht, 
--dht-listen-port,
	--dht-entry-point.
	* src/Dictionary.{h, cc} (remove): New function.
	* src/prefs.h
	* src/DefaultBtMessageFactory.h
	* src/BtHandshakeMessage.cc
	* src/ActivePeerConnectionCommand.cc
	* src/SocketCore.{h, cc}: Added datagram socket support.
	* src/DefaultBtMessageFactory.cc
	* src/BtSetup.cc: Add BtContext to DHTPeerAnnounceStorage here.
	Create DHT commands.
	* src/BtMessageFactory.h
	* src/PeerMessageUtil.{h, cc}

1 files changed, 150 insertions, 0 deletions

diff --git a/src/DHTAbstractNodeLookupTask.cc b/src/DHTAbstractNodeLookupTask.cc
new file mode 100644
index 00000000..9bc8ddf8
--- /dev/null
+++ b/src/DHTAbstractNodeLookupTask.cc
@@ -0,0 +1,150 @@
+/* <!-- copyright */
+/*
+ * aria2 - The high speed download utility
+ *
+ * Copyright (C) 2006 Tatsuhiro Tsujikawa
+ *
+ * This program 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 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * In addition, as a special exception, the copyright holders give
+ * permission to link the code of portions of this program with the
+ * OpenSSL library under certain conditions as described in each
+ * individual source file, and distribute linked combinations
+ * including the two.
+ * You must obey the GNU General Public License in all respects
+ * for all of the code used other than OpenSSL.  If you modify
+ * file(s) with this exception, you may extend this exception to your
+ * version of the file(s), but you are not obligated to do so.  If you
+ * do not wish to do so, delete this exception statement from your
+ * version.  If you delete this exception statement from all source
+ * files in the program, then also delete it here.
+ */
+/* copyright --> */
+#include "DHTAbstractNodeLookupTask.h"
+#include "DHTRoutingTable.h"
+#include "DHTMessageDispatcher.h"
+#include "DHTMessageFactory.h"
+#include "DHTMessage.h"
+#include "DHTNode.h"
+#include "DHTNodeLookupEntry.h"
+#include "DHTMessageCallbackImpl.h"
+#include "DHTBucket.h"
+#include "LogFactory.h"
+#include "Util.h"
+#include "DHTIDCloser.h"
+
+DHTAbstractNodeLookupTask::DHTAbstractNodeLookupTask(const unsigned char* targetID):
+  _inFlightMessage(0)
+{
+  memcpy(_targetID, targetID, DHT_ID_LENGTH);
+}
+
+void DHTAbstractNodeLookupTask::onReceived(const DHTMessageHandle& message)
+{
+  --_inFlightMessage;
+  onReceivedInternal(message);
+  DHTNodeLookupEntries newEntries = toEntries(getNodesFromMessage(message));
+  size_t count = 0;
+  for(DHTNodeLookupEntries::const_iterator i = newEntries.begin();
+      i != newEntries.end(); ++i) {
+    if(memcmp(_localNode->getID(), (*i)->_node->getID(), DHT_ID_LENGTH) != 0) {
+      _entries.push_front(*i);
+      ++count;
+    }
+  }
+  _logger->debug("%u node lookup entries added.", count);
+  stable_sort(_entries.begin(), _entries.end(), DHTIDCloser(_targetID));
+  _entries.erase(unique(_entries.begin(), _entries.end()), _entries.end());
+  _logger->debug("%u node lookup entries are unique.", _entries.size());
+  if(_entries.size() > DHTBucket::K) {
+    _entries.erase(_entries.begin()+DHTBucket::K, _entries.end());
+  }
+  if(needsAdditionalOutgoingMessage()) {
+    sendMessage();
+  }
+  if(_inFlightMessage == 0) {
+    _logger->debug("Finished node_lookup for node ID %s",
+		   Util::toHex(_targetID, DHT_ID_LENGTH).c_str());
+    onFinish();
+    updateBucket();
+    _finished = true;
+  }
+}
+
+void DHTAbstractNodeLookupTask::onTimeout(const DHTNodeHandle& node)
+{
+  _logger->debug("node lookup message timeout for node ID=%s",
+		 Util::toHex(node->getID(), DHT_ID_LENGTH).c_str());
+  --_inFlightMessage;
+  for(DHTNodeLookupEntries::iterator i = _entries.begin(); i != _entries.end(); ++i) {
+    if((*i)->_node == node) {
+      _entries.erase(i);
+      break;
+    }
+  }
+  if(needsAdditionalOutgoingMessage()) {
+    sendMessage();
+  }
+  if(_inFlightMessage == 0) {
+    _logger->debug("Finished node_lookup for node ID %s",
+		   Util::toHex(_targetID, DHT_ID_LENGTH).c_str());
+    onFinish();
+    updateBucket();
+    _finished = true;
+  }  
+}
+
+void DHTAbstractNodeLookupTask::sendMessage()
+{
+  for(DHTNodeLookupEntries::iterator i = _entries.begin(); i != _entries.end() && _inFlightMessage < ALPHA; ++i) {
+    if((*i)->_used == false) {
+      ++_inFlightMessage;
+      (*i)->_used = true;
+      DHTMessageHandle m = createMessage((*i)->_node);
+      _dispatcher->addMessageToQueue(m, new DHTMessageCallbackImpl(this));
+    }
+  }
+}
+
+void DHTAbstractNodeLookupTask::updateBucket()
+{
+  // TODO we have to something here?
+}
+
+void DHTAbstractNodeLookupTask::startup()
+{
+  _entries = toEntries(_routingTable->getClosestKNodes(_targetID));
+  if(_entries.empty()) {
+    _finished = true;
+  } else {
+    // TODO use RTT here
+    _inFlightMessage = 0;
+    sendMessage();
+    if(_inFlightMessage == 0) {
+      _logger->debug("No message was sent in this lookup stage. Finished.");
+      _finished = true;
+    }
+  }
+}
+
+DHTNodeLookupEntries DHTAbstractNodeLookupTask::toEntries(const DHTNodes& nodes) const
+{
+  DHTNodeLookupEntries entries;
+  for(DHTNodes::const_iterator i = nodes.begin(); i != nodes.end(); ++i) {
+    DHTNodeLookupEntryHandle e = new DHTNodeLookupEntry(*i);
+    entries.push_back(e);
+  }
+  return entries;
+}