将.NET System.Int64转换为IP地址

Question

我在Windbg中有以下System.Net.IPAddress对象，并希望将m_address（4294967295 m_address）字段转换为相应的点四进制表示法。我怎样才能做到这一点？我看到m_ToString的值为00000000。这个字符串是如何获得的？

Name:        System.Net.IPAddress
MethodTable: 71c3d860
EEClass:     71a299f0
Size:        40(0x28) bytes
File:        C:WindowsMicrosoft.NetassemblyGAC_MSILSystemv4.0_4.0.0.0__b77a5c561934e089System.dll
Fields:
      MT    Field   Offset                 Type VT     Attr    Value Name
727e821c  40018b1        4         System.Int64  1 instance 4294967295 m_Address
727f2248  40018b2       14        System.String  0 instance 00000000 m_ToString
71c42030  40018b6       1c         System.Int32  1 instance        2 m_Family
727e1994  40018b7       18      System.UInt16[]  0 instance 022c20a8 m_Numbers
727e821c  40018b8        c         System.Int64  1 instance 0 m_ScopeId
727f3aa4  40018b9       20         System.Int32  1 instance        0 m_HashCode
71c3d860  40018ad      7ec System.Net.IPAddress  0   static 022c1ff8 Any
71c3d860  40018ae      7f0 System.Net.IPAddress  0   static 022c203c Loopback
71c3d860  40018af      7f4 System.Net.IPAddress  0   static 022c2080 Broadcast
71c3d860  40018b0      7f8 System.Net.IPAddress  0   static 022c2080 None
71c3d860  40018b3      7fc System.Net.IPAddress  0   static 022c20c4 IPv6Any
71c3d860  40018b4      800 System.Net.IPAddress  0   static 022c2108 IPv6Loopback
71c3d860  40018b5      804 System.Net.IPAddress  0   static 022c214c IPv6None

因此，在断点处，m_Address字段似乎没有地址。在执行UdpClient.Receive方法之后。我得到以下内容。

0:000> !DumpObj /d 024a20f8
Name:        System.Net.IPAddress
MethodTable: 71c3d860
EEClass:     71a299f0
Size:        40(0x28) bytes
File:        C:WindowsMicrosoft.NetassemblyGAC_MSILSystemv4.0_4.0.0.0__b77a5c561934e089System.dll
Fields:
      MT    Field   Offset                 Type VT     Attr    Value Name
727e821c  40018b1        4         System.Int64  1 instance 100731402 m_Address
727f2248  40018b2       14        System.String  0 instance 024a2198 m_ToString
71c42030  40018b6       1c         System.Int32  1 instance        2 m_Family
727e1994  40018b7       18      System.UInt16[]  0 instance 024a2120 m_Numbers
727e821c  40018b8        c         System.Int64  1 instance 0 m_ScopeId
727f3aa4  40018b9       20         System.Int32  1 instance        0 m_HashCode
71c3d860  40018ad      7ec System.Net.IPAddress  0   static 022c1ff8 Any
71c3d860  40018ae      7f0 System.Net.IPAddress  0   static 022c203c Loopback
71c3d860  40018af      7f4 System.Net.IPAddress  0   static 022c2080 Broadcast
71c3d860  40018b0      7f8 System.Net.IPAddress  0   static 022c2080 None
71c3d860  40018b3      7fc System.Net.IPAddress  0   static 022c20c4 IPv6Any
71c3d860  40018b4      800 System.Net.IPAddress  0   static 022c2108 IPv6Loopback
71c3d860  40018b5      804 System.Net.IPAddress  0   static 022c214c IPv6None
0:000> !DumpObj /d 024a2198
Name:        System.String
MethodTable: 727f2248
EEClass:     72423444
Size:        32(0x20) bytes
File:        C:WindowsMicrosoft.NetassemblyGAC_32mscorlibv4.0_4.0.0.0__b77a5c561934e089mscorlib.dll
String:      10.10.1.6
Fields:
      MT    Field   Offset                 Type VT     Attr    Value Name
727f3aa4  40000aa        4         System.Int32  1 instance        9 m_stringLength
727f2c40  40000ab        8          System.Char  1 instance       31 m_firstChar
727f2248  40000ac        c        System.String  0   shared   static Empty

但问题仍然存在，将Int64转换为IP地址的数学公式是什么？

Answer 1

IP地址是4个8位八位字节。

例如，big-endian格式的值0x2414188f将是IP地址"143.24.20.36"。

605296783==0x2414188f

0x2414188f==1001000001010000011000001000111

00100100。00010100。00011000。10001111

因为这是Big Endian，你需要颠倒字节的顺序，这样

00100100==36

00010100==20

00011000==24

10001111==143

换句话说，取Int64值（也称为long）。将其转换为二进制表示形式（byte[]）。读取中的第一个字节并将其转换为int。这将是ip地址的第四个（最后一个）八位字节。读取第二个字节转换为int，这是ip的第三个八位字节。读取第三个字节—这是第二个八位字节。读取最后一个字节—这是第一个八位字节。

我现在没有我的IDE，但这应该可以做到

var bytes = BitConverter.GetBytes(value);
var fourthOctet = BitConverter.ToInt32(bytes,0);
var thirdOctet = BitConverter.ToInt32(bytes,1);
var secondOctet = BitConverter.ToInt32(bytes,2);
var firstOctet = BitConverter.ToInt32(bytes,3);

Answer 2

using System;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
namespace SOFAcrobatics
{
    public static class Launcher
    {
        public static void Main ()
        {
            Console.WriteLine(Launcher.IPv4ToQuadNotation(new IPAddress(4294967295)));
            // outputs 255.255.255.255
            Console.ReadKey(true);
        }
        public static String IPv4ToQuadNotation (IPAddress ip)
        {
            String output = String.Empty;
            foreach (Match m in Regex.Matches(ip.Address.ToString("X8"), @"[A-F0-9]{2}"))
            {
                output += (Int32.Parse(m.Value, NumberStyles.HexNumber) + ".");
            }
            return output.Substring(0, (output.Length - 1));
        }
    }
}