套接字在讀取之前關閉

我正在嘗試使用我的 Socket 包裝器連接到指定的 whois 服務器以接收一些資訊（是的，我知道 TcpClient 存在）。為此，我做了兩節課。一 - SocketClient - 接受 Socket 并具有處理所有連接內容的方法。（我沒有包括 IDisposable 實作）

 public class SocketClient : ISocketClient
{
    private const int HEADER_SIZE = 4;
    private Socket _socket;
    private bool disposedValue;

    public SocketClient(Socket socket) { _socket = socket; }

    public virtual Stream Connect(IPEndPoint endPoint)
    {
        _socket.Connect(endPoint);
        return new NetworkStream(_socket);
    }
    public void Send(Stream networkStream, string message, Encoding encoding)
    {
        var bodyBytes = encoding.GetBytes(message);
        var headerBytes = BitConverter.GetBytes(IPAddress.HostToNetworkOrder(bodyBytes.Length   HEADER_SIZE));
        networkStream.Write(headerBytes, 0, HEADER_SIZE);
        networkStream.Write(bodyBytes, 0, bodyBytes.Length);
    }
    public string Receive(Stream networkStream)
    {
        var header = ReadStream(networkStream, HEADER_SIZE);
        var bodyLength = IPAddress.NetworkToHostOrder(BitConverter.ToInt32(header)) -HEADER_SIZE;
        var bodyBytes = ReadStream(networkStream, bodyLength); //Here exception is thrown
        return Encoding.UTF8.GetString(bodyBytes);
    }
    static byte[] ReadStream(Stream networkStream, int bytesToRead)
    {
        var buffer = new byte[bytesToRead];
        var bytesRead = 0;
        while (bytesRead < bytesToRead)
        {
            var bytesReceived = networkStream.Read(buffer, bytesRead, bytesToRead - bytesRead);
            if (bytesReceived == 0)
                throw new SocketIsClosedException("Tried to read from closed socket.");
            bytesRead  = bytesReceived;
        }
        return buffer;
    }

第二 - WhoisResolver - 接受 SocketClient 并使用它來發送和接收 whois 資訊。

 public class WhoisResolver :  IWhoisResolver
{
    private ISocketClient _socketClient;
    private bool disposedValue;

    public WhoisResolver(ISocketClient socketClient)
    {
        _socketClient = socketClient;
    }
    public  string? Lookup(string fullDomainName, string whoisServerAddress, int whoisServerPort = 43)
    {
        try
        {
            var ip = Dns.GetHostAddresses(whoisServerAddress).First();
            var stream = _socketClient.Connect(new IPEndPoint(ip, whoisServerPort));
            _socketClient.Send(stream, $"{fullDomainName}\r\n",System.Text.Encoding.ASCII); //Here socket is still open
            var response = _socketClient.Receive(stream);
            _socketClient.Disconnect(false);
            return response;
        }catch 
        {
            return null;
        }
    }
}

這是我如何使用它：

        var whoisServer = "whois.crsnic.net";
        var domainName = "testdomain";
        var tld = "net";
        var socketClient = new SocketClient(new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp));
        var resolver = new WhoisResolver(socketClient);

        var result =  resolver.Lookup($"{domainName}.{tld}", whoisServer);

每次我的程式嘗試從流中讀取時，我都會隨機得到兩種例外：

- 無法從傳輸連接讀取資料：現有連接被遠程主機強行關閉。

-試圖從關閉的套接字中讀取。

當我使用帶有緩沖流和流讀取器/寫入器的 TcpClient 時，一切正常。

uj5u.com熱心網友回復：

如上面的評論所述，問題在于閱讀訊息長度的方式。我認為訊息頭是前 4 個位元組，但是當我閱讀它時，它的訊息長度超過了 20000000 個位元組。似乎很明顯，但例外情況非常具有誤導性。

標籤：C＃ asp.net 核心 插座 联网 .net-6.0

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