twisterp2pbittorrentblockchainnetworkipv6microbloggingdecentralizedsocial-networkdhttwister-coretwisterarmyp2p-networktwister-servertwister-ipv6
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
132 lines
5.3 KiB
132 lines
5.3 KiB
11 years ago
|
<?xml version="1.0" encoding="utf-8" ?>
|
||
|
|
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
||
|
|
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
|
||
|
|
<head>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
||
|
|
<meta name="generator" content="Docutils 0.10: http://docutils.sourceforge.net/" />
|
||
|
|
<title></title>
|
||
|
|
<meta name="author" content="Arvid Norberg, arvid@rasterbar.com" />
|
||
|
|
<link rel="stylesheet" type="text/css" href="../../css/base.css" />
|
||
|
|
<link rel="stylesheet" type="text/css" href="../../css/rst.css" />
|
||
|
|
<script type="text/javascript">
|
||
|
|
/* <![CDATA[ */
|
||
|
|
(function() {
|
||
|
|
var s = document.createElement('script'), t = document.getElementsByTagName('script')[0];
|
||
|
|
s.type = 'text/javascript';
|
||
|
|
s.async = true;
|
||
|
|
s.src = 'http://api.flattr.com/js/0.6/load.js?mode=auto';
|
||
|
|
t.parentNode.insertBefore(s, t);
|
||
|
|
})();
|
||
|
|
/* ]]> */
|
||
|
|
</script>
|
||
|
|
<link rel="stylesheet" href="style.css" type="text/css" />
|
||
|
|
<style type="text/css">
|
||
|
|
/* Hides from IE-mac \*/
|
||
|
|
* html pre { height: 1%; }
|
||
|
|
/* End hide from IE-mac */
|
||
|
|
</style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<div class="document">
|
||
|
|
<div id="container">
|
||
|
|
<div id="headerNav">
|
||
|
|
<ul>
|
||
|
|
<li class="first"><a href="/">Home</a></li>
|
||
|
|
<li><a href="../../products.html">Products</a></li>
|
||
|
|
<li><a href="../../contact.html">Contact</a></li>
|
||
|
|
</ul>
|
||
|
|
</div>
|
||
|
|
<div id="header">
|
||
|
|
<h1><span>Rasterbar Software</span></h1>
|
||
|
|
<h2><span>Software developement and consulting</span></h2>
|
||
|
|
</div>
|
||
|
|
<div id="main">
|
||
|
|
|
||
|
|
<table class="docinfo" frame="void" rules="none">
|
||
|
|
<col class="docinfo-name" />
|
||
|
|
<col class="docinfo-content" />
|
||
|
|
<tbody valign="top">
|
||
|
|
<tr><th class="docinfo-name">Author:</th>
|
||
|
|
<td>Arvid Norberg, <a class="last reference external" href="mailto:arvid@rasterbar.com">arvid@rasterbar.com</a></td></tr>
|
||
|
|
</tbody>
|
||
|
|
</table>
|
||
|
|
<div class="section" id="mainline-dht-extensions">
|
||
|
|
<h1>Mainline DHT extensions</h1>
|
||
|
|
<p>libtorrent implements a few extensions to the Mainline DHT protocol.</p>
|
||
|
|
<div class="section" id="get-peers-response">
|
||
|
|
<h2>get_peers response</h2>
|
||
|
|
<p>libtorrent always responds with <tt class="docutils literal">nodes</tt> to a get_peers request. If it has
|
||
|
|
peers for the specified info-hash, it will return <tt class="docutils literal">values</tt> as well. This is
|
||
|
|
because just because some peer announced to us, doesn't mean that we are
|
||
|
|
among the 8 closest nodes of the info hash. libtorrent also keeps traversing
|
||
|
|
nodes using get_peers until it has found the 8 closest ones, and then announces
|
||
|
|
to those nodes.</p>
|
||
|
|
</div>
|
||
|
|
<div class="section" id="forward-compatibility">
|
||
|
|
<h2>forward compatibility</h2>
|
||
|
|
<p>In order to support future DHT messages, any message which is not recognized
|
||
|
|
but has either an <tt class="docutils literal">info_hash</tt> or <tt class="docutils literal">target</tt> argument is interpreted as
|
||
|
|
find node for that target. i.e. it returns nodes. This allows future messages
|
||
|
|
to be properly forwarded by clients that don't understand them instead of
|
||
|
|
being blocked.</p>
|
||
|
|
</div>
|
||
|
|
<div class="section" id="client-identification">
|
||
|
|
<h2>client identification</h2>
|
||
|
|
<p>In each DHT packet, an extra key is inserted named "v". This is a string
|
||
|
|
describing the client and version used. This can help alot when debugging
|
||
|
|
and finding errors in client implementations. The string is encoded as four
|
||
|
|
characters, two characters describing the client and two characters interpreted
|
||
|
|
as a binary number describing the client version.</p>
|
||
|
|
<p>Currently known clients:</p>
|
||
|
|
<table border="1" class="docutils">
|
||
|
|
<colgroup>
|
||
|
|
<col width="65%" />
|
||
|
|
<col width="35%" />
|
||
|
|
</colgroup>
|
||
|
|
<tbody valign="top">
|
||
|
|
<tr><td>uTorrent</td>
|
||
|
|
<td><tt class="docutils literal">UT</tt></td>
|
||
|
|
</tr>
|
||
|
|
<tr><td>libtorrent</td>
|
||
|
|
<td><tt class="docutils literal">LT</tt></td>
|
||
|
|
</tr>
|
||
|
|
<tr><td>MooPolice</td>
|
||
|
|
<td><tt class="docutils literal">MP</tt></td>
|
||
|
|
</tr>
|
||
|
|
<tr><td>GetRight</td>
|
||
|
|
<td><tt class="docutils literal">GR</tt></td>
|
||
|
|
</tr>
|
||
|
|
</tbody>
|
||
|
|
</table>
|
||
|
|
</div>
|
||
|
|
<div class="section" id="ipv6-support">
|
||
|
|
<h2>IPv6 support</h2>
|
||
|
|
<p><strong>This extension is superseeded by</strong> <a class="reference external" href="http://bittorrent.org/beps/bep_0032.html">BEP 32</a>.</p>
|
||
|
|
<p>The DHT messages that don't support IPv6 are the <tt class="docutils literal">nodes</tt> replies.
|
||
|
|
They encode all the contacts as 6 bytes packed together in sequence in a
|
||
|
|
string. The problem is that IPv6 endpoints cannot be encoded as 6 bytes, but
|
||
|
|
needs 18 bytes. The extension libtorrent applies is to add another key, called
|
||
|
|
<tt class="docutils literal">nodes2</tt>.</p>
|
||
|
|
<p><tt class="docutils literal">nodes2</tt> may be present in replies that contains a <tt class="docutils literal">nodes</tt> key. It is encoded
|
||
|
|
as a list of strings. Each string represents one contact and is encoded as 20
|
||
|
|
bytes node-id and then a variable length encoded IP address (6 bytes in IPv4 case
|
||
|
|
and 18 bytes in IPv6 case).</p>
|
||
|
|
<p>As an optimization, libtorrent does not include the extra key in case there are
|
||
|
|
only IPv4 nodes present.</p>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<div id="footer">
|
||
|
|
<span>Copyright © 2005 Rasterbar Software.</span>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<script src="http://www.google-analytics.com/urchin.js" type="text/javascript">
|
||
|
|
</script>
|
||
|
|
<script type="text/javascript">
|
||
|
|
_uacct = "UA-1599045-1";
|
||
|
|
urchinTracker();
|
||
|
|
</script>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|