Tail Fragmentation (#9476)

v2rayN/ServiceLib/Services/CoreConfig/Singbox/SingboxRoutingService.cs

@@ -96,6 +96,15 @@ public partial class CoreConfigSingboxService
                         new() { protocol = ["dns"] },
                     ],
                 });
+                if (_config.CoreBasicItem.EnableFinalFragment)
+                {
+                    _coreConfig.route.rules.Add(new()
+                    {
+                        protocol = ["tls"],
+                        action = "route-options",
+                        tls_record_fragment = true,
+                    });
+                }
             }
             else
             {
@@ -104,6 +113,14 @@ public partial class CoreConfigSingboxService
                     port = [53],
                     action = "hijack-dns",
                 });
+                if (_config.CoreBasicItem.EnableFinalFragment)
+                {
+                    _coreConfig.route.rules.Add(new()
+                    {
+                        action = "route-options",
+                        tls_record_fragment = true,
+                    });
+                }
             }
 
             var hostsDomains = new List<string>();

v2rayN/ServiceLib/Services/CoreConfig/V2ray/CoreConfigV2rayService.cs

@@ -60,6 +60,10 @@ public partial class CoreConfigV2rayService(CoreConfigContext context)
             {
                 ApplyOutboundFragment();
             }
+            if (_config.CoreBasicItem.EnableFinalFragment)
+            {
+                ApplyFinalFragment();
+            }
             ApplyOutboundBindInterface();
             ApplyOutboundSendThrough();
 
@@ -204,6 +208,10 @@ public partial class CoreConfigV2rayService(CoreConfigContext context)
             {
                 ApplyOutboundFragment();
             }
+            if (_config.CoreBasicItem.EnableFinalFragment)
+            {
+                ApplyFinalFragment();
+            }
             ApplyOutboundBindInterface();
             ApplyOutboundSendThrough();
             //ret.Msg =string.Format(ResUI.SuccessfulConfiguration"), node.getSummary());
@@ -276,6 +284,10 @@ public partial class CoreConfigV2rayService(CoreConfigContext context)
             {
                 ApplyOutboundFragment();
             }
+            if (_config.CoreBasicItem.EnableFinalFragment)
+            {
+                ApplyFinalFragment();
+            }
             ApplyOutboundBindInterface();
             ApplyOutboundSendThrough();
 

v2rayN/ServiceLib/Services/CoreConfig/V2ray/V2rayOutboundService.cs

@@ -826,29 +826,7 @@ public partial class CoreConfigV2rayService
                                              && (n.streamSettings?.sockopt?.dialerProxy?.IsNullOrEmpty() ?? true))
                 .ToList();
 
-        var configPackets = _config.Fragment4RayItem?.Packets ?? "tlshello";
-        var configLength = _config.Fragment4RayItem?.Length ?? "50-100";
-        var configDelay = _config.Fragment4RayItem?.Interval ?? "10-20";
-
-        var fragmentMask = new Mask4Ray
-        {
-            type = "fragment",
-            settings = new MaskSettings4Ray
-            {
-                packets = configPackets,
-                length = configLength,
-                delay = configDelay,
-            }
-        };
-        var noiseMask = new Mask4Ray
-        {
-            type = "noise",
-            settings = new MaskSettings4Ray
-            {
-                length = "10-20",
-                delay = "10-16",
-            }
-        };
+        var (fragmentMask, noiseMask) = BuildFragmentsMasks();
 
         foreach (var outbound in actOutboundWithTlsList)
         {
@@ -882,4 +860,67 @@ public partial class CoreConfigV2rayService
             outbound.streamSettings.finalmask = finalMaskJsonObj;
         }
     }
+
+    private void ApplyFinalFragment()
+    {
+        var (fragmentMask, noiseMask) = BuildFragmentsMasks();
+        var actOutboundList = _coreConfig.outbounds.Where(n => n.tag.StartsWith(Global.ProxyTag)).ToList();
+
+        var fragmentFreedom = new Outbounds4Ray()
+        {
+            tag = $"{Global.ProxyTag}-fragment-freedom",
+            protocol = "freedom",
+            streamSettings = new StreamSettings4Ray
+            {
+                finalmask = new Finalmask4Ray
+                {
+                    tcp = [fragmentMask],
+                    udp = [noiseMask],
+                }
+            }
+        };
+
+        foreach (var outbound in actOutboundList)
+        {
+            var index = _coreConfig.outbounds.IndexOf(outbound);
+            var originalTag = outbound.tag;
+            var afterTag = $"fragment-{originalTag}";
+            var cloneFragmentFreedom = JsonUtils.DeepCopy(fragmentFreedom);
+            cloneFragmentFreedom.tag = originalTag;
+            cloneFragmentFreedom.streamSettings.sockopt ??= new();
+            cloneFragmentFreedom.streamSettings.sockopt.dialerProxy = afterTag;
+
+            outbound.tag = afterTag;
+            _coreConfig.outbounds.Insert(index, cloneFragmentFreedom);
+        }
+    }
+
+    private (Mask4Ray tcpFragment, Mask4Ray udpNoise) BuildFragmentsMasks()
+    {
+        var configPackets = _config.Fragment4RayItem?.Packets ?? "tlshello";
+        var configLength = _config.Fragment4RayItem?.Length ?? "50-100";
+        var configDelay = _config.Fragment4RayItem?.Interval ?? "10-20";
+
+        var fragmentMask = new Mask4Ray
+        {
+            type = "fragment",
+            settings = new MaskSettings4Ray
+            {
+                packets = configPackets,
+                length = configLength,
+                delay = configDelay,
+            }
+        };
+        var noiseMask = new Mask4Ray
+        {
+            type = "noise",
+            settings = new MaskSettings4Ray
+            {
+                length = "10-20",
+                delay = "10-16",
+            }
+        };
+
+        return (fragmentMask, noiseMask);
+    }
 }