public BEncodedDictionary GetMetaData(InfoHash hash, out bool netError)
{
netError = false;
WireMessage message;
ExtHandShack exths;
long metadataSize;
int piecesNum;
byte ut_metadata;
try
{
//连接
if (!client.ConnectAsync(EndPoint.Address, EndPoint.Port).Wait(5000))
{
netError = true;
Trace.WriteLine("Connect Timeout", "Socket");
return(null);
}
stream = client.GetStream();
//发送握手
message = new HandShack(hash);
SendMessage(message);
//接受握手
message = ReceiveMessage <HandShack>(1);
if (!message.Legal || !(message as HandShack).SupportExtend)
{
netError = true;
Trace.WriteLine(EndPoint, "HandShack Fail");
return(null);
}
//发送拓展握手
message = new ExtHandShack()
{
SupportUtMetadata = true
};
SendMessage(message);
//接受拓展
exths = ReceiveMessage <ExtHandShack>();
if (!exths.Legal || !exths.CanGetMetadate || exths.MetadataSize > MaxMetadataSize || exths.MetadataSize <= 0)
{
netError = true;
Trace.WriteLine(EndPoint, "ExtendHandShack Fail");
return(null);
}
metadataSize = exths.MetadataSize;
ut_metadata = exths.UtMetadata;
piecesNum = (int)Math.Ceiling(metadataSize / (decimal)PieceLength);
//开始接受pieces
var rtask = ReceivePiecesAsync(metadataSize, piecesNum);
//开始发送piece请求
for (int i = 0; i < piecesNum; i++)
{
message = new ExtQueryPiece(ut_metadata, i);
SendMessage(message);
}
//等待pieces接收完毕
rtask.Wait();
var rawBytes = rtask.Result;
if (rawBytes == null)
{
return(null);
}
//检查hash值是否正确
using (var sha1 = new System.Security.Cryptography.SHA1CryptoServiceProvider())
{
byte[] infohash = sha1.ComputeHash(rawBytes);
if (!infohash.SequenceEqual(hash.Hash))
{
Trace.WriteLine(EndPoint, "Hash Wrong");
return(null);
}
}
return(BEncodedDictionary.DecodeTorrent(rawBytes));
}
catch (AggregateException ex)
{
throw ex.InnerException;
}
finally
{
client?.Close();
}
}
public async Task <(BEncodedDictionary, bool)> GetMetaDataAsync(InfoHash hash)
{
try
{
//连接
Task connectTask = client.ConnectAsync(EndPoint.Address, EndPoint.Port), waitTask = Task.Delay(5000);
await Task.WhenAny(waitTask, connectTask);
if (!connectTask.IsCompleted || connectTask.Status != TaskStatus.RanToCompletion)
{
return(null, true);
}
stream = client.GetStream();
//发送握手
WireMessage message = new HandShack(hash);
await SendMessageAsync(message);
//接受握手
message = await ReceiveMessageAsync <HandShack>(1);
if (!message.Legal || !((HandShack)message).SupportExtend)
{
return(null, true);
}
//发送拓展握手
message = new ExtHandShack()
{
SupportUtMetadata = true
};
await SendMessageAsync(message);
//接受拓展
var exths = await ReceiveMessageAsync <ExtHandShack>();
if (!exths.Legal || !exths.CanGetMetadate || exths.MetadataSize > MaxMetadataSize || exths.MetadataSize <= 0)
{
return(null, true);
}
var metadataSize = exths.MetadataSize;
var utMetadata = exths.UtMetadata;
var piecesNum = (int)Math.Ceiling(metadataSize / (decimal)PieceLength);
var metaTask = ReceivePiecesAsync(metadataSize, piecesNum);
//开始发送piece请求
for (int i = 0; i < piecesNum; i++)
{
message = new ExtQueryPiece(utMetadata, i);
await SendMessageAsync(message);
}
//等待pieces接收完毕
var metadata = await metaTask;
if (metadata == null)
{
return(null, false);
}
//检查hash值是否正确
using (var sha1 = new System.Security.Cryptography.SHA1CryptoServiceProvider())
{
byte[] infohash = sha1.ComputeHash(metadata);
if (infohash.SequenceEqual(hash.Hash))
{
return(BEncodedDictionary.DecodeTorrent(metadata), false);
}
return(null, false);
}
}
catch (AggregateException ex)
{
throw ex.InnerException;
}
finally
{
client?.Close();
}
}
