ClashDotNetFramework-src/NetFilterHelper/Utils/SystemHelper.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace NetFilterHelper.Utils
{
    public class SystemHelper
    {
        /// <summary>
        /// The function determines whether the current operating system is a 
        /// 64-bit operating system.
        /// </summary>
        /// <returns>
        /// The function returns true if the operating system is 64-bit; 
        /// otherwise, it returns false.
        /// </returns>
        public static bool Is64BitOperatingSystem()
        {
            if (IntPtr.Size == 8)  // 64-bit programs run only on Win64
            {
                return true;
            }
            else  // 32-bit programs run on both 32-bit and 64-bit Windows
            {
                // Detect whether the current process is a 32-bit process 
                // running on a 64-bit system.
                bool flag;
                return ((DoesWin32MethodExist("kernel32.dll", "IsWow64Process") &&
                    IsWow64Process(GetCurrentProcess(), out flag)) && flag);
            }
        }

        /// <summary>
        /// The function determins whether a method exists in the export 
        /// table of a certain module.
        /// </summary>
        /// <param name="moduleName">The name of the module</param>
        /// <param name="methodName">The name of the method</param>
        /// <returns>
        /// The function returns true if the method specified by methodName 
        /// exists in the export table of the module specified by moduleName.
        /// </returns>
        static bool DoesWin32MethodExist(string moduleName, string methodName)
        {
            IntPtr moduleHandle = GetModuleHandle(moduleName);
            if (moduleHandle == IntPtr.Zero)
            {
                return false;
            }
            return (GetProcAddress(moduleHandle, methodName) != IntPtr.Zero);
        }

        [DllImport("kernel32.dll")]
        static extern IntPtr GetCurrentProcess();

        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        static extern IntPtr GetModuleHandle(string moduleName);

        [DllImport("kernel32", CharSet = CharSet.Auto, SetLastError = true)]
        static extern IntPtr GetProcAddress(IntPtr hModule,
            [MarshalAs(UnmanagedType.LPStr)] string procName);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        [return: MarshalAs(UnmanagedType.Bool)]
        static extern bool IsWow64Process(IntPtr hProcess, out bool wow64Process);

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool Wow64DisableWow64FsRedirection(ref IntPtr ptr);

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool Wow64RevertWow64FsRedirection(IntPtr ptr);
    }
}