webScoket 和 C# 建立Socket连接
最近使用的web项目中,需要服务器直接触发前端显示效果。
所以研究了一下websocket:
名词解释:
WebSocket
WebSocket协议是一种双向通信协议,它建立在TCP之上,同http一样通过TCP来传输数据,但是它和http最大的不同有两点:
1.WebSocket是一种双向通信协议,在建立连接后,WebSocket服务器和Browser/UA都能主动的向对方发送或接收数据,就像Socket一样,不同的是WebSocket是一种建立在Web基础上的一种简单模拟Socket的协议;
2.WebSocket需要通过握手连接,类似于TCP它也需要客户端和服务器端进行握手连接,连接成功后才能相互通信。
当Web应用程序调用new WebSocket(url)接口时,Browser就开始了与地址为url的WebServer建立握手连接的过程。
客户端向服务器发送请求:
GET /chat HTTP/1.1
Host: server.example.com
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key:dGhlIHNhbXBsZSBub25jZQ==
Origin: http://example.com
Sec-WebSocket-Protocol: chat,superchat
Sec-WebSocket-Version: 13
服务器端返回内容:
HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: xsOSgr30aKL2GNZKNHKmeT1qYjA=
请求中的【Sec-WebSocket-Key】是随机发送的。而服务器返回的【Sec-WebSocket-Accept】是将【Sec-WebSocket-Key】加上一个固定字符串【258EAFA5-E914-47DA-95CA-C5AB0DC85B11】,并使用SHA-1加密后,再进行BASE-64编码生成的。
一个简单的DEMO:
前端页面:
<!DOCTYPE html> <html> <head> <title>Web Socket Client</title> </head> <body style="padding:10px;"> <h1>聊天室</h1> <div style="margin:5px 0px;"> Address: <div><input id="address" type="text" value="ws://127.0.0.1:1818" style="width:400px;" /></div> </div> <div style="margin:5px 0px;"> Name: <div><input id="name" type="text" value="Byron" style="width:400px;" /></div> </div> <div> <button id="connect" onclick="connect();">connect server</button> <button id="disconnect" onclick="quit();">disconnect</button> <button id="clear" onclick="clearMsg();">clear</button> </div> <h5 style="margin:4px 0px;">Message:</h5> <div id="message" style="border:solid 1px #333; padding:4px; width:400px; overflow:auto; background-color:#404040; height:300px; margin-bottom:8px; font-size:14px;"> </div> <input id="text" type="text" onkeypress="enter(event);" style="width:340px" /> <button id="send" onclick="send();">send</button> <script type="text/javascript"> var name=document.getElementById('name').value; var msgContainer=document.getElementById('message'); var text=document.getElementById('text'); function connect () { var address=document.getElementById('address').value; ws=new WebSocket(address); ws.onopen=function(e){ var msg=document.createElement('div'); msg.style.color='#0f0'; msg.innerHTML="Server > connection open."; msgContainer.appendChild(msg); ws.send('{'+document.getElementById('name').value+'}'); }; ws.onmessage=function(e){ var msg=document.createElement('div'); msg.style.color='#fff'; msg.innerHTML=e.data; msgContainer.appendChild(msg); }; ws.onerror=function(e){ var msg=document.createElement('div'); msg.style.color='#0f0'; msg.innerHTML='Server > '+e.data; msgContainer.appendChild(msg); }; ws.onclose=function(e){ var msg=document.createElement('div'); msg.style.color='#0f0'; msg.innerHTML="Server > connection closed by server."; msgContainer.appendChild(msg); }; text.focus(); } function quit(){ if(ws){ ws.close(); var msg=document.createElement('div'); msg.style.color='#0f0'; msg.innerHTML='Server > connection closed.'; msgContainer.appendChild(msg); ws=null; } } function send(){ ws.send(text.value); setTimeout(function(){ msgContainer.scrollTop=msgContainer.getBoundingClientRect().height; },100); text.value=''; text.focus(); } function clearMsg(){ msgContainer.innerHTML=""; } function enter(event){ if(event.keyCode==13){ send(); } } </script> </body> </html>
后台代码(C#):
class Program { private static Socket listener; private static Hashtable ht; static void Main(string[] args) { int port = 1818;//监听端口为1818端口 ht = new Hashtable();//用于存放客户端的连接socket byte[] buffer = new byte[1024]; var localEP = new IPEndPoint(IPAddress.Any, port); listener = new Socket(localEP.Address.AddressFamily, SocketType.Stream, ProtocolType.Tcp); try { listener.Bind(localEP); listener.Listen(10); Console.WriteLine("等待客户端连接...."); while (true) { Socket clientSocket = listener.Accept(); //接收到客户端的连接 var th = new Thread(new ParameterizedThreadStart(Receive)); th.Start(clientSocket); } } catch (Exception e) { Console.WriteLine(e.ToString()); } } /// <summary> /// 线程调用 /// </summary> private static void Receive(object o)//Socket clientSocket) { Socket clientSocket = (Socket)o; clientSocket.Blocking = true; IPEndPoint clientipe = (IPEndPoint)clientSocket.RemoteEndPoint; // Console.WriteLine("[" + clientipe.Address.ToString() + "] Connected"); var key = string.Format("{0}-X-Q-X-{1}", clientipe.Address.ToString(), clientipe.Port); if (!ht.ContainsKey(key)) { //将ip地址设置为hashTable的key值 若hashTable中存在该ip地址则不再ht中添加socket以免发送重复数据 ht.Add(key, clientSocket); } Console.WriteLine("接收到了客户端:ip" + clientSocket.RemoteEndPoint.ToString() + "的连接"); byte[] buffer = new byte[1024]; int length = clientSocket.Receive(buffer); clientSocket.Send(PackHandShakeData(GetSecKeyAccetp(buffer, length))); Console.WriteLine("已经发送握手协议了...."); //接收用户姓名信息 length = clientSocket.Receive(buffer); string xm = AnalyticData(buffer, length); clientSocket.Send(PackData("连接时间:" + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"))); try { while (true) { var errLs = new List<object>(); //接受客户端数据 Console.WriteLine("等待客户端数据...."); try { length = clientSocket.Receive(buffer);//接受客户端信息 } catch (SocketException e) { //去除字典 Console.WriteLine(e.Message); try { foreach (DictionaryEntry de in ht) { if (de.Value == clientSocket) { ht.Remove(de.Key); } } } catch (Exception ex) { Console.WriteLine(ex.Message); } } string clientMsg = AnalyticData(buffer, length); Console.WriteLine("接受到客户端数据:" + clientMsg); //发送数据 string sendMsg = "" + clientMsg; Console.WriteLine("发送数据:“" + sendMsg + "” 至客户端...."); //遍历hashTable中的数据获取Socket发送数据 foreach (DictionaryEntry de in ht) { try { var sc = (Socket)de.Value; sc.Send(PackData(clientSocket.RemoteEndPoint.ToString() + xm + "说:" + sendMsg)); } catch (Exception e) { Console.WriteLine("Num:{0} err:{1}", ht.Count, e); errLs.Add(de.Key); } } if (errLs != null && errLs.Any()) { foreach (var item in errLs) { ht.Remove(item); } } Thread.Sleep(1000); } } catch (SocketException e) { //去除字典 Console.WriteLine(e.Message); } catch (System.ObjectDisposedException e) { //去除字典 Console.WriteLine(e.Message); } catch (Exception e) { Console.WriteLine(e.Message); } } /// <summary> /// 打包握手信息 /// </summary> /// <param name="secKeyAccept">Sec-WebSocket-Accept</param> /// <returns>数据包</returns> private static byte[] PackHandShakeData(string secKeyAccept) { var responseBuilder = new StringBuilder(); responseBuilder.Append("HTTP/1.1 101 Switching Protocols" + Environment.NewLine); responseBuilder.Append("Upgrade: websocket" + Environment.NewLine); responseBuilder.Append("Connection: Upgrade" + Environment.NewLine); responseBuilder.Append("Sec-WebSocket-Accept: " + secKeyAccept + Environment.NewLine + Environment.NewLine); //如果把上一行换成下面两行,才是thewebsocketprotocol-17协议,但居然握手不成功,目前仍没弄明白! //responseBuilder.Append("Sec-WebSocket-Accept: " + secKeyAccept + Environment.NewLine); //responseBuilder.Append("Sec-WebSocket-Protocol: chat" + Environment.NewLine); return Encoding.UTF8.GetBytes(responseBuilder.ToString()); } /// <summary> /// 生成Sec-WebSocket-Accept /// </summary> /// <param name="handShakeText">客户端握手信息</param> /// <returns>Sec-WebSocket-Accept</returns> private static string GetSecKeyAccetp(byte[] handShakeBytes, int bytesLength) { string handShakeText = Encoding.UTF8.GetString(handShakeBytes, 0, bytesLength); string key = string.Empty; Regex r = new Regex(@"Sec\-WebSocket\-Key:(.*?)\r\n"); Match m = r.Match(handShakeText); if (m.Groups.Count != 0) { key = Regex.Replace(m.Value, @"Sec\-WebSocket\-Key:(.*?)\r\n", "$1").Trim(); } byte[] encryptionString = SHA1.Create().ComputeHash(Encoding.ASCII.GetBytes(key + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11")); return Convert.ToBase64String(encryptionString); } /// <summary> /// 解析客户端数据包 /// </summary> /// <param name="recBytes">服务器接收的数据包</param> /// <param name="recByteLength">有效数据长度</param> /// <returns></returns> private static string AnalyticData(byte[] recBytes, int recByteLength) { if (recByteLength < 2) { return string.Empty; } bool fin = (recBytes[0] & 0x80) == 0x80; // 1bit,1表示最后一帧 if (!fin) { return string.Empty;// 超过一帧暂不处理 } bool mask_flag = (recBytes[1] & 0x80) == 0x80; // 是否包含掩码 if (!mask_flag) { return string.Empty;// 不包含掩码的暂不处理 } int payload_len = recBytes[1] & 0x7F; // 数据长度 byte[] masks = new byte[4]; byte[] payload_data; if (payload_len == 126) { Array.Copy(recBytes, 4, masks, 0, 4); payload_len = (UInt16)(recBytes[2] << 8 | recBytes[3]); payload_data = new byte[payload_len]; Array.Copy(recBytes, 8, payload_data, 0, payload_len); } else if (payload_len == 127) { Array.Copy(recBytes, 10, masks, 0, 4); byte[] uInt64Bytes = new byte[8]; for (int i = 0; i < 8; i++) { uInt64Bytes[i] = recBytes[9 - i]; } UInt64 len = BitConverter.ToUInt64(uInt64Bytes, 0); payload_data = new byte[len]; for (UInt64 i = 0; i < len; i++) { payload_data[i] = recBytes[i + 14]; } } else { Array.Copy(recBytes, 2, masks, 0, 4); payload_data = new byte[payload_len]; Array.Copy(recBytes, 6, payload_data, 0, payload_len); } for (var i = 0; i < payload_len; i++) { payload_data[i] = (byte)(payload_data[i] ^ masks[i % 4]); } return Encoding.UTF8.GetString(payload_data); } /// <summary> /// 打包服务器数据 /// </summary> /// <param name="message">数据</param> /// <returns>数据包</returns> private static byte[] PackData(string message) { byte[] contentBytes = null; byte[] temp = Encoding.UTF8.GetBytes(message); if (temp.Length < 126) { contentBytes = new byte[temp.Length + 2]; contentBytes[0] = 0x81; contentBytes[1] = (byte)temp.Length; Array.Copy(temp, 0, contentBytes, 2, temp.Length); } else if (temp.Length < 0xFFFF) { contentBytes = new byte[temp.Length + 4]; contentBytes[0] = 0x81; contentBytes[1] = 126; contentBytes[2] = (byte)(temp.Length & 0xFF); contentBytes[3] = (byte)(temp.Length >> 8 & 0xFF); Array.Copy(temp, 0, contentBytes, 4, temp.Length); } else { // 暂不处理超长内容 } return contentBytes; } }