add Android process finder feature

android_wrapper.go

@@ -11,6 +11,21 @@ type DialerController interface {
 	ProtectFd(int) bool
 }
 
+// ProcessFinder is an interface for Android process finding functionality.
+// Apps should implement FindProcessByConnection()
+// and pass the implementation to RegisterProcessFinder() before starting the core.
+type ProcessFinder interface {
+	// FindProcessByConnection finds the UID of the process that owns the given connection.
+	//
+	// network: Protocol type: "tcp" or "udp"
+	// srcIP: Source IP address
+	// srcPort: Source port
+	// destIP: Destination IP address
+	// destPort: Destination port
+	// Returns the UID of the owning process, or -1 if not found.
+	FindProcessByConnection(network, srcIP string, srcPort int, destIP string, destPort int) int
+}
+
 func InitDns(controller DialerController, server string) {
 	dns.InitDns(server, func(fd uintptr) {
 		controller.ProtectFd(int(fd))
@@ -32,3 +47,18 @@ func RegisterListenerController(controller DialerController) {
 		controller.ProtectFd(int(fd))
 	})
 }
+
+// RegisterProcessFinder registers an Android process finder with Xray-core,
+// enabling per-app routing based on UID. Must be called before starting the
+// core for process-based routing rules to work.
+// Pass nil to unregister a previously registered finder.
+func RegisterProcessFinder(finder ProcessFinder) {
+	if finder == nil {
+		c.RegisterProcessFinder(nil)
+		return
+	}
+
+	c.RegisterProcessFinder(func(network, srcIP string, srcPort int, destIP string, destPort int) int {
+		return finder.FindProcessByConnection(network, srcIP, srcPort, destIP, destPort)
+	})
+}

controller/controller_android.go

@@ -3,8 +3,10 @@
 package controller
 
 import (
+	"fmt"
 	"syscall"
 
+	corenet "github.com/xtls/xray-core/common/net"
 	xinternet "github.com/xtls/xray-core/transport/internet"
 )
 
@@ -23,3 +25,23 @@ func RegisterListenerController(controller func(fd uintptr)) {
 		return conn.Control(controller)
 	})
 }
+
+// RegisterProcessFinder registers an Android process finder with Xray-core,
+// enabling per-app routing based on UID. Must be called before starting the
+// core for process-based routing rules to work.
+// Pass nil to unregister a previously registered finder.
+func RegisterProcessFinder(finder func(network, srcIP string, srcPort int, destIP string, destPort int) int) {
+	if finder == nil {
+		corenet.RegisterAndroidProcessFinder(nil)
+		return
+	}
+
+	corenet.RegisterAndroidProcessFinder(func(network, srcIP string, srcPort uint16, destIP string, destPort uint16) (int, string, string, error) {
+		if destPort == 0 || destIP == "" {
+			return 0, "", "", fmt.Errorf("process finder: no destination for %s %s:%d", network, srcIP, srcPort)
+		}
+
+		uid := finder(network, srcIP, int(srcPort), destIP, int(destPort))
+		return uid, fmt.Sprintf("%d", uid), "", nil
+	})
+}