使用chrome或fiddler截取WebSocket数据包

使用chrome截取WebSocket数据包

先找到一个使用websocket通讯的网站作为测试，比如：
http://www.websocket.org/echo.html

使用chrome的Chrome Developer tools

Chrome Developer tools直接可以在Network下面的WS标签中找到WebSocket的链接，直接点击即可查看。

可以看更多的详情：
chrome://net-internals/#events

使用fiddler

Fiddler则需要添加自定义的规则，操作如下
打开Fiddler -> Rules -> Customize Rules，会打开 FiddlerScript
然后编辑如下规则：

import System.Threading;

// ...

class Handlers
{
    // ...
    static function Main()
    {
        // ...
        //
        // Print Web Socket frame every 2 seconds
        //
        printSocketTimer =
            new System.Threading.Timer(PrintSocketMessage, null, 0, 2000);
    }
    // Create a first-in, first-out queue
    static var socketMessages = new System.Collections.Queue();
    static var printSocketTimer = null;
    static var requestBodyBuilder = new System.Text.StringBuilder();
    static var requestUrlBuilder = new System.Text.StringBuilder();
    static var requestPayloadIsJson = false;
    static var requestPartCount = 0;
    //
    // Listen to WebSocketMessage event, and add the socket messages
    // to the static queue.
    //
    static function OnWebSocketMessage(oMsg: WebSocketMessage)
    {
        Monitor.Enter(socketMessages);
        socketMessages.Enqueue(oMsg);
        Monitor.Exit(socketMessages);
    }
    //
    // Take socket messages from the static queue, and generate fake
    // HTTP requests that will be caught by Fiddler. 
    //
    static function PrintSocketMessage(stateInfo: Object)
    {
        Monitor.Enter(socketMessages);
        while (socketMessages.Count > 0)
        {
            var oMsg = socketMessages.Dequeue();

            ExtractSocketMessage(oMsg);
        }
        Monitor.Exit(socketMessages);
    }
    //
    // Build web socket message information in JSON format, and send this JSON
    // information in a fake HTTP request that will be caught by Fiddler
    //
    // If a frame is split in multiple messages, following function will combine
    // them into one 
    //
    static function ExtractSocketMessage(oMsg: WebSocketMessage)
    {
        if (oMsg.FrameType != WebSocketFrameTypes.Continuation)
        {
            var messageID = String.Format(
                "{0}.{1}", oMsg.IsOutbound ? "Client" : "Server", oMsg.ID);
            var wsSession = GetWsSession(oMsg);
            requestUrlBuilder.AppendFormat("{0}.{1}", wsSession, messageID);
            requestBodyBuilder.Append("{");
            requestBodyBuilder.AppendFormat("\"doneTime\": \"{0}\",", 
                oMsg.Timers.dtDoneRead.ToString("hh:mm:ss.fff"));
            requestBodyBuilder.AppendFormat("\"messageType\": \"{0}\",", 
                oMsg.FrameType);
            requestBodyBuilder.AppendFormat("\"messageID\": \"{0}\",", messageID);
            requestBodyBuilder.AppendFormat("\"wsSession\": \"{0}\",", wsSession);
            requestBodyBuilder.Append("\"payload\": ");
            var payloadString = oMsg.PayloadAsString();
          if (oMsg.FrameType == WebSocketFrameTypes.Binary)
            {
                payloadString = HexToString(payloadString); 
            }

            if (payloadString.StartsWith("{"))
            {
                requestPayloadIsJson = true;
            }
            else
            {
                requestBodyBuilder.Append("\"");
            }
            requestBodyBuilder.AppendFormat("{0}", payloadString);
        }
        else
        {
            var payloadString = HexToString(oMsg.PayloadAsString());
            requestBodyBuilder.AppendFormat("{0}", payloadString);
        }
        requestPartCount++;
        if (oMsg.IsFinalFrame)
        {
            if (!requestPayloadIsJson)
            {
                requestBodyBuilder.Append("\"");
            }
            requestBodyBuilder.AppendFormat(", \"requestPartCount\": \"{0}\"",
                requestPartCount);
            requestBodyBuilder.Append("}");

            SendRequest(requestUrlBuilder.ToString(), requestBodyBuilder.ToString());
            requestBodyBuilder.Clear();
            requestUrlBuilder.Clear();
            requestPayloadIsJson = false;
            requestPartCount = 0;
        }
    }
    //
    // Generate fake HTTP request with JSON data that will be caught by Fiddler
    // We can inspect this request in "Inspectors" tab -> "JSON" sub-tab
    //
    static function SendRequest(urlPath: String, message: String)
    {
        var request = String.Format(
            "POST http://fakewebsocket/{0} HTTP/1.1\n" +
            "User-Agent: Fiddler\n" +
            "Content-Type: application/json; charset=utf-8\n" +
            "Host: fakewebsocket\n" +
            "Content-Length: {1}\n\n{2}",
            urlPath, message.Length, message);
            FiddlerApplication.oProxy.SendRequest(request, null);
    }

    //
    // Unfortunately, WebSocketMessage class does not have a member for 
    // Web Socket session number. Therefore, we are extracting session number
    // from its string output.
    //
    static function GetWsSession(oMsg: WebSocketMessage)
    {
        var message = oMsg.ToString();
        var index = message.IndexOf(".");
        var wsSession = message.Substring(0, index);
        return wsSession;
    }
    //
    // Extract Hex to String.
    // E.g., 7B-22-48-22-3A-22-54-72-61-6E to {"H":"TransportHub","M":"
    //
    static function HexToString(sourceHex: String)
    {
        sourceHex = sourceHex.Replace("-", "");
        var sb = new System.Text.StringBuilder();
        for (var i = 0; i < sourceHex.Length; i += 2)
        {
            var hs = sourceHex.Substring(i, 2);
            sb.Append(Convert.ToChar(Convert.ToUInt32(hs, 16)));
        }
        var ascii = sb.ToString();
        return ascii;

    }
}

参考

http://www.codeproject.com/Articles/718660/Debug-Inspect-WebSocket-traffic-with-Fiddler