using linker.libs; using linker.libs.extends; using Microsoft.Win32.SafeHandles; using System.Net; using System.Runtime.InteropServices; using System.Text; namespace linker.tun { internal sealed class LinkerLinuxTunDevice : ILinkerTunDevice { private string name = string.Empty; public string Name => name; public bool Running => fs != null; private string interfaceLinux = string.Empty; private FileStream fs = null; private SafeFileHandle safeFileHandle; private IPAddress address; private byte prefixLength = 24; public LinkerLinuxTunDevice(string name) { this.name = name; } public bool SetUp(IPAddress address, IPAddress gateway, byte prefixLength, out string error) { error = string.Empty; this.address = address; this.prefixLength = prefixLength; if (Running) { error = ($"Adapter already exists"); return false; } if (Create(out error) == false) { return false; } if (Open(out error) == false) { Shutdown(); return false; } interfaceLinux = GetLinuxInterfaceNum(); return true; } private bool Create(out string error) { error = string.Empty; CommandHelper.Linux(string.Empty, new string[] { $"ip tuntap add mode tun dev {Name}", $"ip addr del {address}/{prefixLength} dev {Name}", $"ip addr add {address}/{prefixLength} dev {Name}", $"ip link set dev {Name} up" }); string str = CommandHelper.Linux(string.Empty, new string[] { $"ifconfig" }); if (str.Contains(Name) == false) { error = CommandHelper.Linux(string.Empty, new string[] { $"ip tuntap add mode tun dev {Name}" }); return false; } return true; } private bool Open(out string error) { error = string.Empty; SafeFileHandle _safeFileHandle = File.OpenHandle("/dev/net/tun", FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite, FileOptions.Asynchronous); if (_safeFileHandle.IsInvalid) { _safeFileHandle?.Dispose(); Shutdown(); error = $"open file /dev/net/tun fail {Marshal.GetLastWin32Error()}"; return false; } byte[] ifreqFREG0 = Encoding.ASCII.GetBytes(this.Name); Array.Resize(ref ifreqFREG0, 16); byte[] ifreqFREG1 = { 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; byte[] ifreq = BytesPlusBytes(ifreqFREG0, ifreqFREG1); int ioctl = Ioctl(_safeFileHandle, 1074025674, ifreq); if (ioctl != 0) { _safeFileHandle?.Dispose(); Shutdown(); error = $"Ioctl fail : {ioctl}，{Marshal.GetLastWin32Error()}"; return false; } safeFileHandle = _safeFileHandle; fs = new FileStream(safeFileHandle, FileAccess.ReadWrite, 1500); return true; } public void Shutdown() { try { safeFileHandle?.Dispose(); safeFileHandle = null; fs?.Flush(); fs?.Close(); fs?.Dispose(); fs = null; } catch (Exception) { } interfaceLinux = string.Empty; CommandHelper.Linux(string.Empty, new string[] {$"ip tuntap del mode tun dev {Name}" }); } public void SetMtu(int value) { CommandHelper.Linux(string.Empty, new string[] { $"ip link set dev {Name} mtu {value}" }); } public void SetNat() { IPAddress network = NetworkHelper.ToNetworkIp(address, NetworkHelper.MaskValue(prefixLength)); CommandHelper.Linux(string.Empty, new string[] { $"sysctl -w net.ipv4.ip_forward=1", $"iptables -t nat -A POSTROUTING ! -o {Name} -s {network}/{prefixLength} -j MASQUERADE", }); } public void RemoveNat() { IPAddress network = NetworkHelper.ToNetworkIp(address, NetworkHelper.MaskValue(prefixLength)); string iptableLineNumbers = CommandHelper.Linux(string.Empty, new string[] { $"iptables -t nat -L --line-numbers | grep {network}/{prefixLength} | cut -d' ' -f1" }); if (string.IsNullOrWhiteSpace(iptableLineNumbers) == false) { string[] commands = iptableLineNumbers.Split(Environment.NewLine) .Where(c => string.IsNullOrWhiteSpace(c) == false) .Select(c => $"iptables -t nat -D POSTROUTING {c}").ToArray(); CommandHelper.Linux(string.Empty, commands); } } public void AddRoute(LinkerTunDeviceRouteItem[] ips, IPAddress ip) { string[] commands = ips.Select(item => { uint maskValue = NetworkHelper.MaskValue(item.Mask); IPAddress _ip = NetworkHelper.ToNetworkIp(item.Address, maskValue); return $"ip route add {_ip}/{item.Mask} via {ip} dev {Name} metric 1 "; }).ToArray(); if (commands.Length > 0) { CommandHelper.Linux(string.Empty, commands); } } public void DelRoute(LinkerTunDeviceRouteItem[] ip) { string[] commands = ip.Select(item => { uint maskValue = NetworkHelper.MaskValue(item.Mask); IPAddress _ip = NetworkHelper.ToNetworkIp(item.Address, maskValue); return $"ip route del {_ip}/{item.Mask}"; }).ToArray(); CommandHelper.Linux(string.Empty, commands); } private byte[] buffer = new byte[2 * 1024]; private object writeLockObj = new object(); public ReadOnlyMemory Read() { try { int length = fs.Read(buffer.AsSpan(4)); length.ToBytes(buffer); return buffer.AsMemory(0, length + 4); } catch (Exception) { } return Helper.EmptyArray; } public bool Write(ReadOnlyMemory buffer) { lock (writeLockObj) { try { fs.Write(buffer.Span); fs.Flush(); return true; } catch (Exception) { } return false; } } private string GetLinuxInterfaceNum() { string output = CommandHelper.Linux(string.Empty, new string[] { "ip route" }); foreach (var item in output.Split(Environment.NewLine)) { if (item.StartsWith("default via")) { var strs = item.Split(' '); for (int i = 0; i < strs.Length; i++) { if (strs[i] == "dev") { return strs[i + 1]; } } } } return string.Empty; } public const int O_ACCMODE = 0x00000003; public const int O_RDONLY = 0x00000000; public const int O_WRONLY = 0x00000001; public const int O_RDWR = 0x00000002; public const int O_CREAT = 0x00000040; public const int O_EXCL = 0x00000080; public const int O_NOCTTY = 0x00000100; public const int O_TRUNC = 0x00000200; public const int O_APPEND = 0x00000400; public const int O_NONBLOCK = 0x00000800; public const int O_NDELAY = 0x00000800; public const int O_SYNC = 0x00101000; public const int O_ASYNC = 0x00002000; [DllImport("libc.so.6", EntryPoint = "open", SetLastError = true)] public static extern int Open(string fileName, int mode); [DllImport("libc.so.6", EntryPoint = "ioctl", SetLastError = true)] public static extern int Ioctl(int fd, UInt32 request, byte[] dat); [DllImport("libc.so.6", EntryPoint = "read", SetLastError = true)] internal static extern int Read(int handle, byte[] data, int length); [DllImport("libc.so.6", EntryPoint = "write", SetLastError = true)] internal static extern int Write(int handle, byte[] data, int length); [DllImport("libc.so.6", EntryPoint = "ioctl", SetLastError = true)] private static extern int Ioctl(SafeHandle device, UInt32 request, byte[] dat); private byte[] BytesPlusBytes(byte[] A, byte[] B) { byte[] ret = new byte[A.Length + B.Length - 1 + 1]; int k = 0; for (var i = 0; i <= A.Length - 1; i++) ret[i] = A[i]; k = A.Length; for (var i = k; i <= ret.Length - 1; i++) ret[i] = B[i - k]; return ret; } } }