从一个网卡获取所有网络数据包并将其发送到第二个网卡？ [英] Get all network packets from one network card and send it to the second network card?

问题描述

嗨

我的系统上有两张网卡。

我想写C＃中的一个程序。

第一个网卡接收数据包并将它们发送到第二个网卡。

我写了一个接收第一个数据包网卡的程序。我写了一个程序代码：

Hi
I have two network cards on your system.
I want to write a program in C#.
The first network card receive the packets and sends them to a second network card.
I have written a program that receives the first packet network card.I have written a program code:

private Socket mainSocket;
        private byte[] byteData = new byte[4096];
        private bool bContinueCapturing = false;
 
        private delegate void AddTreeNode(TreeNode node);
 
        public Form1()
        {
            InitializeComponent();
        }
 
        private void Form1_Load(object sender, EventArgs e)
        {
            string strIP = null;
 
            IPHostEntry HosyEntry = Dns.GetHostEntry((Dns.GetHostName()));
            if (HosyEntry.AddressList.Length > 0)
            {
                foreach (IPAddress ip in HosyEntry.AddressList)
                {
                    strIP = ip.ToString();
                    cmbInterfaces.Items.Add(strIP);
                }
            }
        }
 
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (bContinueCapturing)
            {
                mainSocket.Close();
            }
        }
 
        private void btnStart_Click(object sender, EventArgs e)
        {
             
            if (cmbInterfaces.Text == "")
            {
                MessageBox.Show("Select an Interface to capture the packets.", "sniffer",
                    MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }
            try
            {
                if (!bContinueCapturing)
                {
 
                    btnStart.Text = "&Stop";
 
                    bContinueCapturing = true;
 
                    mainSocket = new Socket(AddressFamily.InterNetwork,
                        SocketType.Raw, ProtocolType.IP);
 
                    mainSocket.Bind(new IPEndPoint(IPAddress.Parse(cmbInterfaces.Text), 0));
 
                    mainSocket.SetSocketOption(SocketOptionLevel.IP,
                                               SocketOptionName.HeaderIncluded,
                                               true);
 
                    byte[] byTrue = new byte[4] { 1, 0, 0, 0 };
                    byte[] byOut = new byte[4] { 1, 0, 0, 0 };
 
                    mainSocket.IOControl(IOControlCode.ReceiveAll,
                                         byTrue,
                                         byOut);
                     
                    mainSocket.Receive(byteData);
                     
                    mainSocket.BeginReceive(byteData, 0, byteData.Length, SocketFlags.None, new AsyncCallback(OnReceive), null);
                }
                else
                {
                    btnStart.Text = "&Start";
                    bContinueCapturing = false;
                    mainSocket.Close();
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "sniffer", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
 
        private void OnReceive(IAsyncResult ar)
        {
             
            try
            {
                 
                int nReceived = mainSocket.EndReceive(ar);
 
                if (bContinueCapturing)
                {
                    byteData = new byte[4096];
                    mainSocket.BeginReceive(byteData, 0, byteData.Length, SocketFlags.None,
                        new AsyncCallback(OnReceive), null);
                }
            }
            catch (ObjectDisposedException)
            {
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "sniffer", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
 
    }

我想编写一个程序来发送收到第二张网卡的数据包。

请帮帮我。

I want to write a program that sends packets received a second network card.
Please help me.

推荐答案

根据SA的评论，你真的必须有充分的理由手动尝试这样的事情



我可能错了，但是，它只有在你有两个不同的网络范围时才能工作，每个网络绑定一个地址到每个网卡 - 监听网卡很容易



- 所以假设你有10.0.0.250绑定到NIC 1，你将收听来自端口的传入流量



NIC 2例如可能在网络192.168.2.x中，假设您的机器是192.168.2.49 - 所以，如何将发送路由到192.168.2.100端口12345是强制使用正确的本地端点： -

As per SA's comments, you'd really have to have a good reason to attempt something like this manually

I may be wrong, but, it can only work if you have two different 'network ranges', with one address from each network bound to each NIC - the listen NIC is easy

- so lets say you have 10.0.0.250 bound to NIC 1, which you will listen to incoming traffic from on a port

NIC 2 for example may be in network 192.168.2.x, lets say your machine is 192.168.2.49 - so, how you route the send to 192.168.2.100 port 12345 is by forcing use of the correct local endpoint :-

var localEndPoint = new IPEndPoint(IPAddress.Parse("192.168.2.49"), port: 0);
var tcpSendClient = new TcpClient(localEndPoint);
tcpSendClient.Connect("192.168.2.100", 12345);

在端点上使用'端口0'表示192.168.2.49表示输出/出站端口是动态的 - 通过指定端点192.168.2.49绕过自动路由

by using 'port 0' in the Endpoint for the 192.168.2.49 means the output/outbound port is dynamic - by specifying the endpoint 192.168.2.49 you circumvent automatic routing

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