単体テストにパケットキャプチャを組み込む α版

NUnitやVisual Studioのテストプロジェクトなどの単体テスト(Unit Test)で、ネットワークのやり取りをテスト条件に加えたかったので、
http://d.hatena.ne.jp/TripleX/20070527
http://msdn2.microsoft.com/ja-jp/library/bew39x2a(VS.80).aspx
このあたりを参考にして、パケットキャプチャを作ってみた。
まだ、きちんとテストしていないので使うときはat your own riskで。

using System;

using System.Collections.Generic;

using System.Text;

using System.Threading;

using System.Net;

using System.Net.Sockets;
namespace PacketUnit

{

    public class StateObject

    {

        // Client socket.

        public Socket workSocket = null;

        // Size of receive buffer.

        public const int BufferSize = 8192;

        // Receive buffer.

        public byte[] buffer = new byte[BufferSize];

        // Received data string.

        //public StringBuilder sb = new StringBuilder();
        public List bytesReceived = new List();
        public bool closed = false;

    }
    public class CaptureCore

    {

        private string ipAddress;

        public string IpAddress

        {

            get { return this.ipAddress; }

            set { this.ipAddress = value; }

        }
        private byte[] bytesCaputured;

        public byte[] BytesCaputured

        {

            get { return this.bytesCaputured; }

        }
        private StateObject state;

        private Socket socket;
        public void StartCapture()

        {

            bytesCaputured = null;
            socket = new Socket(AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.IP);

            socket.Bind(new IPEndPoint(IPAddress.Parse(this.IpAddress),0));
            byte[] byTrue = new byte[4] { 1, 0, 0, 0 };//この設定値の理由は不明

            byte[] byOut = new byte[4];//この設定値の理由は不明
            socket.SetSocketOption(SocketOptionLevel.IP,

                                   SocketOptionName.HeaderIncluded,

                                   true);
            socket.IOControl(IOControlCode.ReceiveAll,

                            byTrue,

                            byOut);
            state = new StateObject();

            state.workSocket = socket;

            socket.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,

                                    new AsyncCallback(ReceiveCallback), state);

            

        }
        public void EndCapture()

        {

            state.closed = true;

            bytesCaputured = state.bytesReceived.ToArray();

        }
        private static void ReceiveCallback(IAsyncResult ar)

        {

            StateObject currentstate = (StateObject)ar.AsyncState;

            Socket currentsocket = currentstate.workSocket;
            int bytesRead = currentsocket.EndReceive(ar);
            if (bytesRead > 0)

            {

                // There might be more data, so store the data received so far.

                //state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));

                for(int i = 0; i < bytesRead; i++)

                {

                    currentstate.bytesReceived.Add(currentstate.buffer[i]);

                }
                // Get the rest of the data.

                if (!currentstate.closed)

                {

                    currentsocket.BeginReceive(currentstate.buffer, 0, StateObject.BufferSize, 0,

                         new AsyncCallback(ReceiveCallback), currentstate);

                }

            }


        }
    }

}

使い方

capture.StartCapture();

//

SomeNetworkOperations();

//

capture.EndCapture();

string captured = ToHexString(capture.BytesCaputured);

string expected = ToHexString(Encoding.ASCII.GetBytes("text to test"));

Assert.IsTrue(captured.IndexOf(expected) > -1);

private string ToHexString(byte[] bytes)

{

    StringBuilder sb = new StringBuilder();

    foreach (byte b in bytes)

    {

        sb.Append(Convert.ToString(b, 16));

    }

    return sb.ToString();

}