通過特定的網絡適配器發送 HttpWebRequest

Question

我有兩個無線網絡適配器連接到我的計算機，每個都連接到不同的網絡。 我想構建一種代理服務器，我的瀏覽器將連接到它，它將從不同的適配器發送 HTTP 請求，因此網頁上的加載時間會更短。 你們知道如何決定從哪個網絡適配器發送 HttpWebRequest 嗎？

謝謝：）

更新

我使用了這段代碼：

public static IPEndPoint BindIPEndPointCallback(ServicePoint servicePoint, IPEndPoint remoteEndPoint, int retryCount)
{
    List<IPEndPoint> ipep = new List<IPEndPoint>();
    foreach (var i in System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces())
    {
        foreach (var ua in i.GetIPProperties().UnicastAddresses)
            ipep.Add(new IPEndPoint(ua.Address, 0));
    }
    return new IPEndPoint(ipep[1].Address, ipep[1].Port);
}

private void button1_Click(object sender, EventArgs e)
{
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://whatismyip.com");
    request.ServicePoint.BindIPEndPointDelegate = new BindIPEndPoint(BindIPEndPointCallback);
    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
    StreamReader sr = new StreamReader(response.GetResponseStream());
    string x = sr.ReadToEnd();
}

但是，即使更改了我從 WhatIsMyIp 獲得的 IP 發送的 IPEndPoint 仍然是一樣的.. 有什么幫助嗎？

Answer 1

BindIPEndPointDelegate很可能就是您想要的。 它允許您強制將特定的本地 IP 作為發送 HttpWebRequest 的端點。

Answer 2

這個例子對我有用：

using System;
using System.Net;

class Program
{
    public static void Main ()
    {
        foreach (var ip in Dns.GetHostAddresses (Dns.GetHostName ())) 
        {
            Console.WriteLine ("Request from: " + ip);
            var request = (HttpWebRequest)HttpWebRequest.Create ("http://ns1.vianett.no/");
            request.ServicePoint.BindIPEndPointDelegate = delegate {
                return new IPEndPoint (ip, 0);
            };
            var response = (HttpWebResponse)request.GetResponse ();
            Console.WriteLine ("Actual IP: " + response.GetResponseHeader ("X-YourIP"));
            response.Close ();
        }
    }
}

Answer 3

這是因為 WebRequest 使用 ServicePointManager，它緩存了用於單個 URI 的實際 ServicePoint。 因此，在您的情況下，BindIPEndPointDelegate 僅調用一次，並且所有后續 CreateRequest 都重用相同的綁定接口。 這是一個實際有效的 TcpClient 低級示例：

        foreach (var iface in NetworkInterface.GetAllNetworkInterfaces())
        {
            if (iface.OperationalStatus == OperationalStatus.Up && iface.NetworkInterfaceType != NetworkInterfaceType.Loopback)
            {
                Console.WriteLine("Interface: {0}\t{1}\t{2}", iface.Name, iface.NetworkInterfaceType, iface.OperationalStatus);
                foreach (var ua in iface.GetIPProperties().UnicastAddresses)
                {
                    Console.WriteLine("Address: " + ua.Address);
                    try
                    {
                        using (var client = new TcpClient(new IPEndPoint(ua.Address, 0)))
                        {
                            client.Connect("ns1.vianett.no", 80);
                            var buf = Encoding.UTF8.GetBytes("GET / HTTP/1.1\r\nConnection: close\r\nHost: ns1.vianett.no\r\n\r\n");
                            client.GetStream().Write(buf, 0, buf.Length);
                            var sr = new StreamReader(client.GetStream());
                            var all = sr.ReadToEnd();
                            var match = Regex.Match(all, "(?mi)^X-YourIP: (?'a'.+)$");
                            Console.WriteLine("Your address is " + (match.Success ? match.Groups["a"].Value : all));
                        }
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }
                }
            }
        }