/// <summary>
/// Return IP and Port of remote connection.
/// </summary>
/// <param name="socket"></param>
/// <returns></returns>
public PeerDetails GetConnectingPeerDetails(Socket socket)
{
PeerDetails peerDetails = new PeerDetails
{
ip = ((IPEndPoint)(socket.RemoteEndPoint)).Address.ToString(),
port = ((IPEndPoint)(socket.RemoteEndPoint)).Port
};
return(peerDetails);
}
/// <summary>
/// Decode peer list sent by remote tracker.
/// </summary>
/// <param name="peers"></param>
/// <param name="offset"></param>
/// <returns></returns>
internal List <PeerDetails> GetCompactPeerList(byte[] peers, int offset)
{
List <PeerDetails> peerList = new List <PeerDetails>();
for (var num = offset; num < peers.Length; num += 6)
{
PeerDetails peer = new PeerDetails
{
infoHash = InfoHash,
peerID = String.Empty,
ip = $"{peers[num]}.{peers[num + 1]}.{peers[num + 2]}.{peers[num + 3]}"
};
peer.port = ((int)peers[num + 4] * 256) + peers[num + 5];
if (peer.ip != Ip) // Ignore self in peers list
{
Log.Logger.Trace($"(Tracker) Peer {peer.ip} Port {peer.port} found.");
peerList.Add(peer);
}
}
return(peerList);
}
private readonly Bencode _Bencode; // Bencode encode/decode
/// <summary>
/// Decodes the announce request BEncoded response recieved from a tracker.
/// </summary>
/// <param name="announceResponse">Announce response.</param>
/// <param name="decodedResponse">Response.</param>
private void DecodeAnnounceResponse(Tracker tracker, byte[] announceResponse, ref AnnounceResponse decodedResponse)
{
if (announceResponse.Length != 0)
{
BNodeBase decodedAnnounce = _Bencode.Decode(announceResponse);
decodedResponse.statusMessage = _Bencode.GetDictionaryEntryString(decodedAnnounce, "failure reason");
if (decodedResponse.statusMessage != "")
{
decodedResponse.failure = true;
return; // If failure present then ignore rest of reply.
}
int.TryParse(_Bencode.GetDictionaryEntryString(decodedAnnounce, "complete"), out decodedResponse.complete);
int.TryParse(_Bencode.GetDictionaryEntryString(decodedAnnounce, "incomplete"), out decodedResponse.incomplete);
BNodeBase field = _Bencode.GetDictionaryEntry(decodedAnnounce, "peers");
if (field != null)
{
decodedResponse.peerList = new List <PeerDetails>();
if (field is BNodeString bNodeString) // Compact peer list reply
{
decodedResponse.peerList = tracker.GetCompactPeerList((bNodeString).str, 0);
}
else if (field is BNodeList bNodeList) // Non-compact peer list reply
{
foreach (var listItem in (bNodeList).list)
{
if (listItem is BNodeDictionary bNodeDictionary)
{
PeerDetails peer = new PeerDetails
{
infoHash = tracker.InfoHash
};
BNodeBase peerDictionaryItem = (bNodeDictionary);
BNodeBase peerField = _Bencode.GetDictionaryEntry(peerDictionaryItem, "ip");
if (peerField != null)
{
peer.ip = Encoding.ASCII.GetString(((BitTorrentLibrary.BNodeString)peerField).str);
}
if (peer.ip.Contains(":"))
{
peer.ip = peer.ip.Substring(peer.ip.LastIndexOf(":", StringComparison.Ordinal) + 1);
}
peerField = _Bencode.GetDictionaryEntry(peerDictionaryItem, "port");
if (peerField != null)
{
peer.port = int.Parse(Encoding.ASCII.GetString(((BitTorrentLibrary.BNodeNumber)peerField).number));
}
if (peer.ip != tracker.Ip) // Ignore self in peers list
{
Log.Logger.Trace($"(Tracker) Peer {peer.ip} Port {peer.port} found.");
decodedResponse.peerList.Add(peer);
}
}
}
}
}
int.TryParse(_Bencode.GetDictionaryEntryString(decodedAnnounce, "interval"), out decodedResponse.interval);
int.TryParse(_Bencode.GetDictionaryEntryString(decodedAnnounce, "min interval"), out decodedResponse.minInterval);
decodedResponse.trackerID = _Bencode.GetDictionaryEntryString(decodedAnnounce, "tracker id");
decodedResponse.statusMessage = _Bencode.GetDictionaryEntryString(decodedAnnounce, "warning message");
decodedResponse.announceCount++;
}
}