使用 c# 套接字放置的服务器响应

Question

我有以下服务器代码：

class Program
{

    
    static void Main(string[] args)
    {
        Socket server = new Socket(AddressFamily.InterNetwork, 
        SocketType.Stream, ProtocolType.Tcp);
        server.Bind(new IPEndPoint(IPAddress.Any, 8000));

        server.Listen();


        while (true)
        {
            Socket client = server.Accept();
            StreamReader streamReader = new StreamReader(new 
            NetworkStream(client));
            StringBuilder buffer = new StringBuilder();
            string eof = new string(new char[] { (char)10, (char)13, 
            (char)10 });

            while (!buffer.ToString().Contains(eof))
            buffer = buffer.Append((char)streamReader.Read());

            Console.WriteLine(buffer);
            StreamWriter streamWriter = new StreamWriter(new 
            NetworkStream(client));

            streamWriter.WriteLine();
            streamWriter.Flush();


        }

    }

    static string createResponse()
    {
        string s = @"
        HTTP/1.1 200 OK
        Date: " + DateTime.Now + @"
        Server: Custom
        Connection: keep-alive
        Allow: OPTIONS, GET, PUT
        Access-Control-Allow-Origin: *
        Access-Control-Allow-Methods GET, POST, PUT, DELETE, HEAD, OPTIONS
        Access-Control-Allow-Headers: *
        Access-Control-Allow-Credentials: true";

        return s;
    }
}

并遵循客户端代码（javascript）：

function connect() {
    fetch('http://127.0.0.1:8000', 
    {
        method: 'put',
        headers: {
            "Content-Type" : "text/html"
        },
        body: "Test"
    });

}

我在服务器中得到以下输出：

OPTIONS / HTTP/1.1
Host: 127.0.0.1:8000
Connection: keep-alive
Accept: */*
Access-Control-Request-Method: PUT
Access-Control-Request-Headers: content-type
Origin: null
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.69 Safari/537.36
Sec-Fetch-Mode: cors
Sec-Fetch-Site: cross-site
Sec-Fetch-Dest: empty
Accept-Encoding: gzip, deflate, br
Accept-Language: de-DE,de;q=0.9,en-US;q=0.8,en;q=0.7

但是我在任何地方都找不到正文，甚至在收到的客户端标头中找不到内容类型/长度 - 为什么？我到底做错了什么？在发送服务器标头后，我尝试将流位置设置为零（尽管这根本没有意义，因为它是网络流），但正如预期的那样，它引发了错误。关于 PUT 方法，HTTP 协议究竟是如何工作的？为了在服务器和客户端之间建立正确的交换，服务器需要提供什么？

Answer 1

感谢上帝，这里有解决方案：

class Program
    {

        static void Main(string[] args)
        {
            Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            server.Bind(new IPEndPoint(IPAddress.Any, 8000));

            server.Listen(int.MaxValue);


            while (true)
            {
                Socket client = server.Accept();
                StreamReader streamReader = new StreamReader(new NetworkStream(client));
                StringBuilder buffer = new StringBuilder();
                string eof = new string(new char[] { (char)10, (char)13, (char)10 });

                while (!buffer.ToString().Contains(eof))
                    buffer = buffer.Append((char)streamReader.Read());



                StreamWriter streamWriter = new StreamWriter(new NetworkStream(client));
                streamWriter.WriteLine(createCORSHeader());
                streamWriter.Flush();


                int contentLength = 0;

                var lines = buffer.ToString().Split('\n');
                for (int i = 0; i < lines.Length; i++)
                {
                    var keyValuePair = lines[i].Split(':');
                    if (keyValuePair.Length < 2)
                        continue;

                    var key = keyValuePair[0];
                    var val = keyValuePair[0 + 1].Substring(1, keyValuePair[1].Length - 1);

                    if (key.Equals("Content-Length"))
                        contentLength = int.Parse(val);
                }


                buffer.Clear();

                for (int i = 0; i < contentLength; i++)
                    buffer.Append((char)streamReader.Read());



                File.AppendAllText("protokoll.txt", "[" + DateTime.Now + "]\t" + buffer.ToString() + Environment.NewLine);


                streamWriter.WriteLine(createPUTResponse());
                streamWriter.Flush();


                client.Close();

                Console.WriteLine("Done.");
            }

        }

        static string createCORSHeader()
        {
            string s = @"
HTTP/1.1 204 No Content
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: POST, GET, OPTIONS, PUT
Access-Control-Allow-Headers: X-PINGOTHER, Content-Type
Access-Control-Max-Age: 86400
Vary: Accept-Encoding, Origin
Keep-Alive: timeout=2, max=100
Connection: Keep-Alive
";

            return s;
        }


        static string createPUTResponse()
        {
            string s = @"
HTTP/1.1 204 No Content
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: POST, GET, OPTIONS, PUT
Access-Control-Allow-Headers: X-PINGOTHER, Content-Type
Access-Control-Max-Age: 86400
Vary: Accept-Encoding, Origin
Keep-Alive: timeout=2, max=100
Connection: Keep-Alive
";

            return s;
        }
    }