/// <summary>
/// 将客户端传递的 IP 地址与端口转换为 <see cref="IPEndPoint"/> 类型。
/// </summary>
private IPEndPoint ConvertClientAddress(GetPeersInfoInput apiInput)
{
if (IPAddress.TryParse(apiInput.Ip, out IPAddress ipAddress))
{
return(new IPEndPoint(ipAddress, apiInput.Port));
}
return(null);
}
public AnnounceInputParameters(GetPeersInfoInput apiInput)
{
Error = new BDictionary();
ClientAddress = ConvertClientAddress(apiInput);
InfoHash = ConvertInfoHash(apiInput);
Event = ConvertTorrentEvent(apiInput);
PeerId = apiInput.Peer_Id;
Uploaded = apiInput.Uploaded;
Downloaded = apiInput.Downloaded;
Left = apiInput.Left;
IsEnableCompact = apiInput.Compact == 1;
PeerWantCount = apiInput.NumWant ?? 30;
}
public async Task GetPeersInfo(GetPeersInfoInput input)
{
// 如果 BT 客户端没有传递 IP，则通过 Context 获得。
if (string.IsNullOrEmpty(input.Ip))
{
input.Ip = _httpContextAccessor.HttpContext.Connection.RemoteIpAddress.MapToIPv4().ToString();
}
// 本机测试用。
input.Ip = "127.0.0.1";
AnnounceInputParameters inputPara = input;
var resultDict = new BDictionary();
// 如果产生了错误，则不执行其他操作，直接返回结果。
if (inputPara.Error.Count == 0)
{
_bitTorrentManager.UpdatePeer(input.Info_Hash, inputPara);
_bitTorrentManager.ClearZombiePeers(input.Info_Hash, TimeSpan.FromMinutes(10));
var peers = _bitTorrentManager.GetPeers(input.Info_Hash);
HandlePeersData(resultDict, peers, inputPara);
// 构建剩余字段信息
// 客户端等待时间
resultDict.Add(TrackerServerConsts.IntervalKey, new BNumber((int)TimeSpan.FromSeconds(30).TotalSeconds));
// 最小等待间隔
resultDict.Add(TrackerServerConsts.MinIntervalKey, new BNumber((int)TimeSpan.FromSeconds(30).TotalSeconds));
// Tracker 服务器的 Id
resultDict.Add(TrackerServerConsts.TrackerIdKey, new BString("Tracker-DEMO"));
// 已完成的 Peer 数量
resultDict.Add(TrackerServerConsts.CompleteKey, new BNumber(_bitTorrentManager.GetComplete(input.Info_Hash)));
// 非做种状态的 Peer 数量
resultDict.Add(TrackerServerConsts.IncompleteKey, new BNumber(_bitTorrentManager.GetInComplete(input.Info_Hash)));
}
else
{
resultDict = inputPara.Error;
}
// 写入响应结果。
var resultDictBytes = resultDict.EncodeAsBytes();
var response = _httpContextAccessor.HttpContext.Response;
response.ContentType = "text/plain";
response.StatusCode = 200;
response.ContentLength = resultDictBytes.Length;
await response.Body.WriteAsync(resultDictBytes);
}
/// <summary>
/// 将 info_hash 参数从 URL 编码转换为标准的字符串。
/// </summary>
private string ConvertInfoHash(GetPeersInfoInput apiInput)
{
var infoHashBytes = HttpUtility.UrlDecodeToBytes(apiInput.Info_Hash);
if (infoHashBytes == null)
{
Error.Add(TrackerServerConsts.FailureKey, new BString("info_hash 参数不能为空."));
return(null);
}
if (infoHashBytes.Length != 20)
{
Error.Add(TrackerServerConsts.FailureKey, new BString($"info_hash 参数的长度 {{{infoHashBytes.Length}}} 不符合 BT 协议规范."));
}
return(BitConverter.ToString(infoHashBytes));
}
/// <summary>
/// 将客户端传递的字符串 Event 转换为 <see cref="TorrentEvent"/> 枚举。
/// </summary>
private TorrentEvent ConvertTorrentEvent(GetPeersInfoInput apiInput)
{
switch (apiInput.Event)
{
case "started":
return(TorrentEvent.Started);
case "stopped":
return(TorrentEvent.Stopped);
case "completed":
return(TorrentEvent.Completed);
default:
return(TorrentEvent.None);
}
}