update news & events

TWASys-App/Models/ServerInfo/NetUtils.cs

@@ -0,0 +1,123 @@
+using System.Net;
+using System.Net.NetworkInformation;
+using System.Net.Sockets;
+
+namespace TWASys_App.Models.ServerInfo
+{
+    public class NetUtils
+    {
+        public static string? GetPrimaryPrivateIPv4String()
+        {
+            if (!Socket.OSSupportsIPv4) return null;
+            try
+            {
+                using var s = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
+                s.Connect(new IPEndPoint(IPAddress.Parse("8.8.8.8"), 53));
+                return (s.LocalEndPoint as IPEndPoint)?.Address.ToString();
+            }
+            catch
+            {
+                // fallback: liệt kê NIC
+                return GetAllPrivateIPsStrings().FirstOrDefault(ip => ip.Contains('.'));
+            }
+        }
+
+        public static string? GetPrimaryPrivateIPv6String()
+        {
+            if (!Socket.OSSupportsIPv6) return null;
+            try
+            {
+                using var s = new Socket(AddressFamily.InterNetworkV6, SocketType.Dgram, ProtocolType.Udp);
+                s.Connect(new IPEndPoint(IPAddress.Parse("2001:4860:4860::8888"), 53));
+                var ip = (s.LocalEndPoint as IPEndPoint)?.Address;
+                return ip is null ? null : FormatIPv6WithScope(ip);
+            }
+            catch
+            {
+                var ip = FirstIPv6_ByEnum();
+                return ip is null ? null : FormatIPv6WithScope(ip);
+            }
+        }
+
+        public static IEnumerable<string> GetAllPrivateIPsStrings()
+        {
+            foreach (var ni in NetworkInterface.GetAllNetworkInterfaces())
+            {
+                if (ni.OperationalStatus != OperationalStatus.Up) continue;
+                if (ni.NetworkInterfaceType is NetworkInterfaceType.Loopback or NetworkInterfaceType.Tunnel) continue;
+
+                var idx = ni.GetIPProperties().GetIPv6Properties()?.Index;
+
+                foreach (var ua in ni.GetIPProperties().UnicastAddresses)
+                {
+                    var ip = ua.Address;
+                    if (IPAddress.IsLoopback(ip)) continue;
+
+                    if (ip.AddressFamily == AddressFamily.InterNetwork)
+                    {
+                        if (IsPrivateIPv4(ip)) yield return ip.ToString();
+                    }
+                    else if (ip.AddressFamily == AddressFamily.InterNetworkV6)
+                    {
+                        if (IsPrivateIPv6(ip)) yield return FormatIPv6WithScope(ip, idx);
+                    }
+                }
+            }
+        }
+
+        // ---------- PUBLIC IP (string) ----------
+        public static async Task<string?> GetPublicIPv4Async(CancellationToken ct = default) =>
+            await FetchFirstAsync(new[] { "https://api.ipify.org", "https://checkip.amazonaws.com", "https://ipv4.icanhazip.com" }, ct);
+
+        public static async Task<string?> GetPublicIPv6Async(CancellationToken ct = default) =>
+            await FetchFirstAsync(new[] { "https://api6.ipify.org", "https://ipv6.icanhazip.com", "https://ifconfig.co/ip" }, ct);
+
+        public static async Task<string?> GetPublicIpAsync(bool preferIPv6 = false, CancellationToken ct = default) =>
+            preferIPv6 ? await GetPublicIPv6Async(ct) ?? await GetPublicIPv4Async(ct)
+                       : await GetPublicIPv4Async(ct) ?? await GetPublicIPv6Async(ct);
+
+        // ---------- helpers ----------
+        static async Task<string?> FetchFirstAsync(IEnumerable<string> urls, CancellationToken ct)
+        {
+            using var http = new HttpClient { Timeout = TimeSpan.FromSeconds(3) };
+            foreach (var u in urls)
+                try
+                {
+                    var s = (await http.GetStringAsync(u, ct)).Trim();
+                    if (!string.IsNullOrWhiteSpace(s)) return s;
+                }
+                catch { /* thử URL kế */ }
+            return null;
+        }
+
+        static IPAddress? FirstIPv6_ByEnum() =>
+            NetworkInterface.GetAllNetworkInterfaces()
+                .Where(n => n.OperationalStatus == OperationalStatus.Up &&
+                            n.NetworkInterfaceType != NetworkInterfaceType.Loopback &&
+                            n.NetworkInterfaceType != NetworkInterfaceType.Tunnel)
+                .SelectMany(n => n.GetIPProperties().UnicastAddresses)
+                .Select(u => u.Address)
+                .FirstOrDefault(ip => ip.AddressFamily == AddressFamily.InterNetworkV6);
+
+        static bool IsPrivateIPv4(IPAddress ip)
+        {
+            var b = ip.GetAddressBytes();
+            return b[0] == 10 || (b[0] == 172 && b[1] is >= 16 and <= 31) || (b[0] == 192 && b[1] == 168);
+        }
+        static bool IsPrivateIPv6(IPAddress ip)
+        {
+            var b = ip.GetAddressBytes();
+            return ((b[0] & 0xFE) == 0xFC) || (b[0] == 0xFE && (b[1] & 0xC0) == 0x80); // fc00::/7, fe80::/10
+        }
+
+        // KHÔNG đụng IPAddress.ScopeId. Nếu link-local, thêm scope = index của NIC.
+        static string FormatIPv6WithScope(IPAddress ip, int? nicIndex = null)
+        {
+            if (ip.AddressFamily != AddressFamily.InterNetworkV6) return ip.ToString();
+            var b = ip.GetAddressBytes();
+            bool linkLocal = b[0] == 0xFE && (b[1] & 0xC0) == 0x80;
+            if (linkLocal && nicIndex is int idx) return $"{ip}%{idx}";
+            return ip.ToString();
+        }
+    }
+}