Add DefaultGateway

examples/vpn/client1-server-client2-override-gateway/client1.json

@@ -0,0 +1,53 @@
+{
+  "log": {
+    "level": "error"
+  },
+  "dns": {
+    "servers": [
+      {
+        "type": "local",
+        "tag": "default"
+      }
+    ]
+  },
+  "endpoints": [
+    {
+      "type": "vpn-client",
+      "tag": "vpn",
+      "address": "10.0.0.2",
+      "key": "1c9b2ccf-b0c0-4c26-868d-a55a4edad3fe",
+      "outbound": {
+        "type": "vless",
+        "tag": "vless-out",
+        "server": "0.0.0.0",
+        "server_port": 8000,
+        "uuid": "9b65b7e1-04c8-4717-8f45-2aa61fd25937",
+        "network": "tcp"
+      }
+    }
+  ],
+  "inbounds": [
+    {
+      "type": "mixed",
+      "tag": "mixed-in",
+      "listen_port": 7897
+    }
+  ],
+  "outbounds": [
+    {
+      "type": "direct",
+      "tag": "direct-out"
+    }
+  ],
+  "route": {
+    "rules": [
+      {
+        "domain_suffix": ".internal",
+        "outbound": "vpn",
+        "override_gateway": "10.0.0.3"
+      }
+    ],
+    "final": "direct-out",
+    "auto_detect_interface": true
+  }
+}

examples/vpn/client1-server-client2-override-gateway/client2.json

@@ -0,0 +1,40 @@
+{
+  "log": {
+    "level": "error"
+  },
+  "dns": {
+    "servers": [
+      {
+        "type": "local",
+        "tag": "default"
+      }
+    ]
+  },
+  "endpoints": [
+    {
+      "type": "vpn-client",
+      "tag": "vpn",
+      "address": "10.0.0.3",
+      "key": "3d74d616-2502-4c17-9cc3-92c366550f4f",
+      "outbound": {
+        "type": "vless",
+        "tag": "vless-out",
+        "server": "0.0.0.0",
+        "server_port": 8000,
+        "uuid": "9b65b7e1-04c8-4717-8f45-2aa61fd25937",
+        "network": "tcp"
+      }
+    }
+  ],
+  "outbounds": [
+    {
+      "type": "direct",
+      "tag": "direct-out"
+    }
+  ],
+  "route": {
+    "final": "direct-out",
+    "default_domain_resolver": "default",
+    "auto_detect_interface": true
+  }
+}

examples/vpn/client1-server-client2-override-gateway/server.json

@@ -0,0 +1,61 @@
+{
+  "log": {
+    "level": "error"
+  },
+  "dns": {
+    "servers": [
+      {
+        "type": "local",
+        "tag": "default"
+      }
+    ]
+  },
+  "endpoints": [
+    {
+      "type": "vpn-server",
+      "tag": "vpn",
+      "address": "10.0.0.1",
+      "users": [
+        {
+          "address": "10.0.0.2",
+          "key": "1c9b2ccf-b0c0-4c26-868d-a55a4edad3fe"
+        },
+        {
+          "address": "10.0.0.3",
+          "key": "3d74d616-2502-4c17-9cc3-92c366550f4f"
+        }
+      ],
+      "inbounds": [
+        {
+          "type": "vless",
+          "tag": "vless-in",
+          "listen": "0.0.0.0",
+          "listen_port": 8000,
+          "users": [
+            {
+              "name": "vless",
+              "uuid": "9b65b7e1-04c8-4717-8f45-2aa61fd25937"
+            }
+          ]
+        }
+      ]
+    }
+  ],
+  "outbounds": [
+    {
+      "type": "direct",
+      "tag": "direct-out"
+    }
+  ],
+  "route": {
+    "rules": [
+      {
+        "source_ip_cidr": "10.0.0.0/24",
+        "outbound": "vpn"
+      }
+    ],
+    "final": "direct-out",
+    "default_domain_resolver": "default",
+    "auto_detect_interface": true
+  }
+}

examples/vpn/client1-server-client2/client1.json

@@ -16,6 +16,7 @@
       "tag": "vpn",
       "address": "10.0.0.2",
       "key": "1c9b2ccf-b0c0-4c26-868d-a55a4edad3fe",
+      "default_gateway": "10.0.0.3",
       "outbound": {
         "type": "vless",
         "tag": "vless-out",
@@ -40,13 +41,7 @@
     }
   ],
   "route": {
-    "rules": [
+    "final": "vpn",
-      {
-        "outbound": "vpn",
-        "override_gateway": "10.0.0.3"
-      }
-    ],
-    "final": "direct-out",
     "auto_detect_interface": true
   }
 }

examples/vpn/proxy_client-server-vpn_client/server.json

@@ -15,6 +15,7 @@
       "type": "vpn-server",
       "tag": "vpn",
       "address": "10.0.0.1",
+      "default_gateway": "10.0.0.2",
       "users": [
         {
           "address": "10.0.0.2",
@@ -47,8 +48,7 @@
     "rules": [
       {
         "inbound": "vless-in",
-        "outbound": "vpn",
+        "outbound": "vpn"
-        "override_gateway": "10.0.0.2"
       }
     ],
     "final": "direct-out",

examples/vpn/server-client/server.json

@@ -15,6 +15,7 @@
       "type": "vpn-server",
       "tag": "vpn",
       "address": "10.0.0.1",
+      "default_gateway": "10.0.0.2",
       "users": [
         {
           "address": "10.0.0.2",
@@ -51,13 +52,7 @@
     }
   ],
   "route": {
-    "rules": [
+    "final": "vpn",
-      {
-        "outbound": "vpn",
-        "override_gateway": "10.0.0.2"
-      }
-    ],
-    "final": "direct-out",
     "default_domain_resolver": "default",
     "auto_detect_interface": true
   }

protocol/vpn/client.go

@@ -29,13 +29,14 @@ func RegisterClientEndpoint(registry *endpoint.Registry) {
 
 type ClientEndpoint struct {
 	outbound.Adapter
-	ctx       context.Context
+	ctx            context.Context
-	outbound  adapter.Outbound
+	outbound       adapter.Outbound
-	router    adapter.ConnectionRouterEx
+	router         adapter.ConnectionRouterEx
-	logger    logger.ContextLogger
+	logger         logger.ContextLogger
-	address   IPv4
+	address        IPv4
-	key       uuid.UUID
+	key            uuid.UUID
-	uotClient *uot.Client
+	defaultGateway IPv4
+	uotClient      *uot.Client
 }
 
 func NewClientEndpoint(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.VPNClientEndpointOptions) (adapter.Endpoint, error) {
@@ -47,13 +48,21 @@ func NewClientEndpoint(ctx context.Context, router adapter.Router, logger log.Co
 	if err != nil {
 		return nil, err
 	}
+	defaultGateway := Loopback.As4()
+	if options.DefaultGateway.IsValid() {
+		if !options.DefaultGateway.Is4() {
+			return nil, E.New("invalid default_gateway: ", options.DefaultGateway)
+		}
+		defaultGateway = options.DefaultGateway.As4()
+	}
 	client := &ClientEndpoint{
-		Adapter: outbound.NewAdapter(C.TypeVPNClient, tag, []string{N.NetworkTCP, N.NetworkUDP}, []string{}),
+		Adapter:        outbound.NewAdapter(C.TypeVPNClient, tag, []string{N.NetworkTCP, N.NetworkUDP}, []string{}),
-		ctx:     ctx,
+		ctx:            ctx,
-		router:  sbUot.NewRouter(router, logger),
+		router:         sbUot.NewRouter(router, logger),
-		logger:  logger,
+		logger:         logger,
-		address: address.As4(),
+		address:        address.As4(),
-		key:     key,
+		key:            key,
+		defaultGateway: defaultGateway,
 	}
 	outboundRegistry := service.FromContext[adapter.OutboundRegistry](ctx)
 	outbound, err := outboundRegistry.CreateOutbound(ctx, router, logger, options.Outbound.Tag, options.Outbound.Type, options.Outbound.Options)
@@ -102,7 +111,7 @@ func (c *ClientEndpoint) DialContext(ctx context.Context, network string, destin
 	if err != nil {
 		return nil, err
 	}
-	gateway := Loopback.As4()
+	gateway := c.defaultGateway
 	if metadata := adapter.ContextFrom(ctx); metadata != nil {
 		if metadata.Gateway != nil {
 			gateway = metadata.Gateway.As4()

protocol/vpn/server.go

@@ -29,15 +29,16 @@ func RegisterServerEndpoint(registry *endpoint.Registry) {
 
 type ServerEndpoint struct {
 	outbound.Adapter
-	logger    logger.ContextLogger
+	logger         logger.ContextLogger
-	inbounds  []adapter.Inbound
+	inbounds       []adapter.Inbound
-	router    adapter.ConnectionRouterEx
+	router         adapter.ConnectionRouterEx
-	address   IPv4
+	address        IPv4
-	addresses map[uuid.UUID]IPv4
+	addresses      map[uuid.UUID]IPv4
-	keys      map[IPv4]uuid.UUID
+	keys           map[IPv4]uuid.UUID
-	conns     map[IPv4]chan net.Conn
+	conns          map[IPv4]chan net.Conn
-	timeout   time.Duration
+	timeout        time.Duration
-	uotClient *uot.Client
+	defaultGateway *netip.Addr
+	uotClient      *uot.Client
 }
 
 func NewServerEndpoint(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.VPNServerEndpointOptions) (adapter.Endpoint, error) {
@@ -51,6 +52,13 @@ func NewServerEndpoint(ctx context.Context, router adapter.Router, logger log.Co
 		router:  sbUot.NewRouter(router, logger),
 		address: address.As4(),
 	}
+	if options.DefaultGateway.IsValid() {
+		if !options.DefaultGateway.Is4() {
+			return nil, E.New("invalid default_gateway: ", options.DefaultGateway)
+		}
+		defaultGateway := options.DefaultGateway
+		server.defaultGateway = &defaultGateway
+	}
 	router = NewRouter(router, logger, server.connHandler)
 	inboundRegistry := service.FromContext[adapter.InboundRegistry](ctx)
 	inbounds := make([]adapter.Inbound, len(options.Inbounds))
@@ -124,6 +132,8 @@ func (s *ServerEndpoint) DialContext(ctx context.Context, network string, destin
 				Addr: Loopback,
 				Port: destination.Port,
 			}
+		} else if s.defaultGateway != nil {
+			gateway = s.defaultGateway
 		} else {
 			return nil, E.New("missing gateway")
 		}