fix(send-through): limit sendThrough to remote egress outbounds

v2rayN/Directory.Packages.props

@@ -12,6 +12,7 @@
     <PackageVersion Include="ReactiveUI.Avalonia" Version="11.4.12" />
     <PackageVersion Include="CliWrap" Version="3.10.1" />
     <PackageVersion Include="Downloader" Version="5.1.0" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
     <PackageVersion Include="H.NotifyIcon.Wpf" Version="2.4.1" />
     <PackageVersion Include="MaterialDesignThemes" Version="5.3.1" />
     <PackageVersion Include="MessageBox.Avalonia" Version="3.3.1.1" />
@@ -26,7 +27,9 @@
     <PackageVersion Include="sqlite-net-pcl" Version="1.9.172" />
     <PackageVersion Include="TaskScheduler" Version="2.12.2" />
     <PackageVersion Include="WebDav.Client" Version="2.9.0" />
+    <PackageVersion Include="xunit" Version="2.9.3" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.4" />
     <PackageVersion Include="YamlDotNet" Version="16.3.0" />
     <PackageVersion Include="ZXing.Net.Bindings.SkiaSharp" Version="0.16.14" />
   </ItemGroup>
-</Project>
+</Project>

v2rayN/ServiceLib.Tests/CoreConfigV2rayServiceTests.cs

@@ -0,0 +1,228 @@
+using System.Text.Json.Nodes;
+using ServiceLib;
+using ServiceLib.Enums;
+using ServiceLib.Models;
+using ServiceLib.Services.CoreConfig;
+using Xunit;
+
+namespace ServiceLib.Tests;
+
+public class CoreConfigV2rayServiceTests
+{
+    private const string SendThrough = "198.51.100.10";
+
+    [Fact]
+    public void GenerateClientConfigContent_OnlyAppliesSendThroughToRemoteProxyOutbounds()
+    {
+        var node = CreateProxyNode("proxy-1", "198.51.100.1", 443);
+        var service = new CoreConfigV2rayService(CreateContext(node));
+
+        var result = service.GenerateClientConfigContent();
+
+        Assert.True(result.Success);
+
+        var outbounds = GetOutbounds(result.Data?.ToString());
+        var proxyOutbound = outbounds.Single(outbound => outbound["tag"]!.GetValue<string>() == Global.ProxyTag);
+        var directOutbound = outbounds.Single(outbound => outbound["tag"]!.GetValue<string>() == Global.DirectTag);
+        var blockOutbound = outbounds.Single(outbound => outbound["tag"]!.GetValue<string>() == Global.BlockTag);
+
+        Assert.Equal(SendThrough, proxyOutbound["sendThrough"]?.GetValue<string>());
+        Assert.Null(directOutbound["sendThrough"]);
+        Assert.Null(blockOutbound["sendThrough"]);
+    }
+
+    [Fact]
+    public void GenerateClientConfigContent_OnlyAppliesSendThroughToChainExitOutbounds()
+    {
+        var exitNode = CreateProxyNode("exit", "198.51.100.2", 443);
+        var entryNode = CreateProxyNode("entry", "198.51.100.3", 443);
+        var chainNode = CreateChainNode("chain", exitNode, entryNode);
+
+        var service = new CoreConfigV2rayService(CreateContext(
+            chainNode,
+            allProxiesMap: new Dictionary<string, ProfileItem>
+            {
+                [exitNode.IndexId] = exitNode,
+                [entryNode.IndexId] = entryNode,
+            }));
+
+        var result = service.GenerateClientConfigContent();
+
+        Assert.True(result.Success);
+
+        var outbounds = GetOutbounds(result.Data?.ToString())
+            .Where(outbound => outbound["protocol"]?.GetValue<string>() is not ("freedom" or "blackhole" or "dns"))
+            .ToList();
+
+        var sendThroughOutbounds = outbounds
+            .Where(outbound => outbound["sendThrough"]?.GetValue<string>() == SendThrough)
+            .ToList();
+        var chainedOutbounds = outbounds
+            .Where(outbound => outbound["streamSettings"]?["sockopt"]?["dialerProxy"] is not null)
+            .ToList();
+
+        Assert.Single(sendThroughOutbounds);
+        Assert.All(chainedOutbounds, outbound => Assert.Null(outbound["sendThrough"]));
+    }
+
+    [Fact]
+    public void GenerateClientConfigContent_DoesNotApplySendThroughToTunRelayLoopbackOutbound()
+    {
+        var node = CreateProxyNode("proxy-1", "198.51.100.4", 443);
+        var config = CreateConfig();
+        config.TunModeItem.EnableLegacyProtect = false;
+
+        var service = new CoreConfigV2rayService(CreateContext(
+            node,
+            config,
+            isTunEnabled: true,
+            tunProtectSsPort: 10811,
+            proxyRelaySsPort: 10812));
+
+        var result = service.GenerateClientConfigContent();
+
+        Assert.True(result.Success);
+
+        var outbounds = GetOutbounds(result.Data?.ToString());
+        Assert.DoesNotContain(outbounds, outbound => outbound["sendThrough"]?.GetValue<string>() == SendThrough);
+    }
+
+    private static CoreConfigContext CreateContext(
+        ProfileItem node,
+        Config? config = null,
+        Dictionary<string, ProfileItem>? allProxiesMap = null,
+        bool isTunEnabled = false,
+        int tunProtectSsPort = 0,
+        int proxyRelaySsPort = 0)
+    {
+        return new CoreConfigContext
+        {
+            Node = node,
+            RunCoreType = ECoreType.Xray,
+            AppConfig = config ?? CreateConfig(),
+            AllProxiesMap = allProxiesMap ?? new(),
+            SimpleDnsItem = new SimpleDNSItem(),
+            IsTunEnabled = isTunEnabled,
+            TunProtectSsPort = tunProtectSsPort,
+            ProxyRelaySsPort = proxyRelaySsPort,
+        };
+    }
+
+    private static Config CreateConfig()
+    {
+        return new Config
+        {
+            IndexId = string.Empty,
+            SubIndexId = string.Empty,
+            CoreBasicItem = new()
+            {
+                LogEnabled = false,
+                Loglevel = "warning",
+                MuxEnabled = false,
+                DefAllowInsecure = false,
+                DefFingerprint = Global.Fingerprints.First(),
+                DefUserAgent = string.Empty,
+                SendThrough = SendThrough,
+                EnableFragment = false,
+                EnableCacheFile4Sbox = true,
+            },
+            TunModeItem = new()
+            {
+                EnableTun = false,
+                AutoRoute = true,
+                StrictRoute = true,
+                Stack = string.Empty,
+                Mtu = 9000,
+                EnableIPv6Address = false,
+                IcmpRouting = Global.TunIcmpRoutingPolicies.First(),
+                EnableLegacyProtect = false,
+            },
+            KcpItem = new(),
+            GrpcItem = new(),
+            RoutingBasicItem = new()
+            {
+                DomainStrategy = Global.DomainStrategies.First(),
+                DomainStrategy4Singbox = Global.DomainStrategies4Sbox.First(),
+                RoutingIndexId = string.Empty,
+            },
+            GuiItem = new(),
+            MsgUIItem = new(),
+            UiItem = new()
+            {
+                CurrentLanguage = "en",
+                CurrentFontFamily = string.Empty,
+                MainColumnItem = [],
+                WindowSizeItem = [],
+            },
+            ConstItem = new(),
+            SpeedTestItem = new(),
+            Mux4RayItem = new()
+            {
+                Concurrency = 8,
+                XudpConcurrency = 8,
+                XudpProxyUDP443 = "reject",
+            },
+            Mux4SboxItem = new()
+            {
+                Protocol = string.Empty,
+            },
+            HysteriaItem = new(),
+            ClashUIItem = new()
+            {
+                ConnectionsColumnItem = [],
+            },
+            SystemProxyItem = new(),
+            WebDavItem = new(),
+            CheckUpdateItem = new(),
+            Fragment4RayItem = null,
+            Inbound = [new InItem
+            {
+                Protocol = EInboundProtocol.socks.ToString(),
+                LocalPort = 10808,
+                UdpEnabled = true,
+                SniffingEnabled = true,
+                RouteOnly = false,
+            }],
+            GlobalHotkeys = [],
+            CoreTypeItem = [],
+            SimpleDNSItem = new(),
+        };
+    }
+
+    private static ProfileItem CreateProxyNode(string indexId, string address, int port)
+    {
+        return new ProfileItem
+        {
+            IndexId = indexId,
+            Remarks = indexId,
+            ConfigType = EConfigType.SOCKS,
+            CoreType = ECoreType.Xray,
+            Address = address,
+            Port = port,
+        };
+    }
+
+    private static ProfileItem CreateChainNode(string indexId, params ProfileItem[] nodes)
+    {
+        var chainNode = new ProfileItem
+        {
+            IndexId = indexId,
+            Remarks = indexId,
+            ConfigType = EConfigType.ProxyChain,
+            CoreType = ECoreType.Xray,
+        };
+        chainNode.SetProtocolExtra(new ProtocolExtraItem
+        {
+            ChildItems = string.Join(',', nodes.Select(node => node.IndexId)),
+        });
+        return chainNode;
+    }
+
+    private static List<JsonObject> GetOutbounds(string? json)
+    {
+        var root = JsonNode.Parse(json ?? throw new InvalidOperationException("Config JSON is missing"))?.AsObject()
+            ?? throw new InvalidOperationException("Failed to parse config JSON");
+        return root["outbounds"]?.AsArray().Select(node => node!.AsObject()).ToList()
+            ?? throw new InvalidOperationException("Config JSON does not contain outbounds");
+    }
+}

v2rayN/ServiceLib.Tests/ServiceLib.Tests.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="xunit" />
+    <PackageReference Include="xunit.runner.visualstudio">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ServiceLib\ServiceLib.csproj" />
+  </ItemGroup>
+
+</Project>

v2rayN/ServiceLib/Resx/ResUI.Designer.cs

@@ -4014,15 +4014,6 @@ namespace ServiceLib.Resx {
             }
         }
         
-        /// <summary>
-        ///   查找类似 e.g. 192.168.1.10 的本地化字符串。
-        /// </summary>
-        public static string TbSettingsSendThroughHint {
-            get {
-                return ResourceManager.GetString("TbSettingsSendThroughHint", resourceCulture);
-            }
-        }
-        
         /// <summary>
         ///   查找类似 Local outbound address (SendThrough) 的本地化字符串。
         /// </summary>

v2rayN/ServiceLib/Resx/ResUI.resx

@@ -1323,9 +1323,6 @@
   <data name="TbSettingsSendThrough" xml:space="preserve">
     <value>Local outbound address (SendThrough)</value>
   </data>
-  <data name="TbSettingsSendThroughHint" xml:space="preserve">
-    <value>e.g. 192.168.1.10</value>
-  </data>
   <data name="TbSettingsSendThroughTip" xml:space="preserve">
     <value>Only applies to Xray. Fill in a local IPv4 address; leave empty to disable.</value>
   </data>

v2rayN/ServiceLib/Resx/ResUI.zh-Hans.resx

@@ -1320,9 +1320,6 @@
   <data name="TbSettingsSendThrough" xml:space="preserve">
     <value>本地出站地址 (SendThrough)</value>
   </data>
-  <data name="TbSettingsSendThroughHint" xml:space="preserve">
-    <value>例如 192.168.1.10</value>
-  </data>
   <data name="TbSettingsSendThroughTip" xml:space="preserve">
     <value>仅对 Xray 生效，填写本机 IPv4；留空则不设置。</value>
   </data>

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

@@ -415,7 +415,37 @@ public partial class CoreConfigV2rayService(CoreConfigContext context)
         var sendThrough = _config.CoreBasicItem.SendThrough?.TrimEx();
         foreach (var outbound in _coreConfig.outbounds ?? [])
         {
-            outbound.sendThrough = sendThrough.IsNullOrEmpty() ? null : sendThrough;
+            outbound.sendThrough = ShouldApplySendThrough(outbound, sendThrough) ? sendThrough : null;
         }
     }
+
+    private static bool ShouldApplySendThrough(Outbounds4Ray outbound, string? sendThrough)
+    {
+        if (sendThrough.IsNullOrEmpty())
+        {
+            return false;
+        }
+
+        if (outbound.protocol is "freedom" or "blackhole" or "dns" or "loopback")
+        {
+            return false;
+        }
+
+        if (outbound.streamSettings?.sockopt?.dialerProxy.IsNullOrEmpty() == false)
+        {
+            return false;
+        }
+
+        var outboundAddress = outbound.settings?.servers?.FirstOrDefault()?.address
+            ?? outbound.settings?.vnext?.FirstOrDefault()?.address
+            ?? outbound.settings?.address?.ToString()
+            ?? string.Empty;
+
+        if (outboundAddress.Equals("localhost", StringComparison.OrdinalIgnoreCase))
+        {
+            return false;
+        }
+
+        return !IPAddress.TryParse(outboundAddress, out var address) || !IPAddress.IsLoopback(address);
+    }
 }

v2rayN/v2rayN.Desktop/Views/OptionSettingWindow.axaml

@@ -338,7 +338,7 @@
                             Grid.Column="1"
                             Width="200"
                             Margin="{StaticResource Margin4}"
-                            Watermark="{x:Static resx:ResUI.TbSettingsSendThroughHint}" />
+                            Watermark="0.0.0.0" />
                         <TextBlock
                             Grid.Row="21"
                             Grid.Column="2"

v2rayN/v2rayN.sln

@@ -32,6 +32,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "GitHub Action", "GitHub Act
 		..\.github\workflows\winget-publish.yml = ..\.github\workflows\winget-publish.yml
 	EndProjectSection
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ServiceLib.Tests", "ServiceLib.Tests\ServiceLib.Tests.csproj", "{E0B6C5C7-ED48-42EB-947A-877779E9F555}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -58,6 +60,10 @@ Global
 		{CB3DE54F-3A26-AE02-1299-311132C32156}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{CB3DE54F-3A26-AE02-1299-311132C32156}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{CB3DE54F-3A26-AE02-1299-311132C32156}.Release|Any CPU.Build.0 = Release|Any CPU
+		{E0B6C5C7-ED48-42EB-947A-877779E9F555}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{E0B6C5C7-ED48-42EB-947A-877779E9F555}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{E0B6C5C7-ED48-42EB-947A-877779E9F555}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{E0B6C5C7-ED48-42EB-947A-877779E9F555}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

v2rayN/v2rayN/Views/OptionSettingWindow.xaml

@@ -406,7 +406,7 @@
                             Width="200"
                             Margin="{StaticResource Margin8}"
                             Style="{StaticResource DefTextBox}"
-                            materialDesign:HintAssist.Hint="{x:Static resx:ResUI.TbSettingsSendThroughHint}" />
+                            materialDesign:HintAssist.Hint="0.0.0.0" />
                         <TextBlock
                             Grid.Row="21"
                             Grid.Column="2"