Add 'preferInterfaceName' parameter to BindToInterface0

Author: nekohasekai

common/control/bind.go

@@ -10,7 +10,7 @@ import (
 
 func BindToInterface(finder InterfaceFinder, interfaceName string, interfaceIndex int) Func {
 	return func(network, address string, conn syscall.RawConn) error {
-		return BindToInterface0(finder, conn, network, address, interfaceName, interfaceIndex)
+		return BindToInterface0(finder, conn, network, address, interfaceName, interfaceIndex, false)
 	}
 }
 
@@ -20,16 +20,16 @@ func BindToInterfaceFunc(finder InterfaceFinder, block func(network string, addr
 		if err != nil {
 			return err
 		}
-		return BindToInterface0(finder, conn, network, address, interfaceName, interfaceIndex)
+		return BindToInterface0(finder, conn, network, address, interfaceName, interfaceIndex, false)
 	}
 }
 
-func BindToInterface0(finder InterfaceFinder, conn syscall.RawConn, network string, address string, interfaceName string, interfaceIndex int) error {
+func BindToInterface0(finder InterfaceFinder, conn syscall.RawConn, network string, address string, interfaceName string, interfaceIndex int, preferInterfaceName bool) error {
 	if interfaceName == "" && interfaceIndex == -1 {
 		return E.New("interface not found: ", interfaceName)
 	}
 	if addr := M.ParseSocksaddr(address).Addr; addr.IsValid() && N.IsVirtual(addr) {
 		return nil
 	}
-	return bindToInterface(conn, network, address, finder, interfaceName, interfaceIndex)
+	return bindToInterface(conn, network, address, finder, interfaceName, interfaceIndex, preferInterfaceName)
 }

common/control/bind_darwin.go

@@ -7,7 +7,7 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-func bindToInterface(conn syscall.RawConn, network string, address string, finder InterfaceFinder, interfaceName string, interfaceIndex int) error {
+func bindToInterface(conn syscall.RawConn, network string, address string, finder InterfaceFinder, interfaceName string, interfaceIndex int, preferInterfaceName bool) error {
 	return Raw(conn, func(fd uintptr) error {
 		var err error
 		if interfaceIndex == -1 {

common/control/bind_linux.go

@@ -12,18 +12,19 @@ import (
 
 var ifIndexDisabled atomic.Bool
 
-func bindToInterface(conn syscall.RawConn, network string, address string, finder InterfaceFinder, interfaceName string, interfaceIndex int) error {
+func bindToInterface(conn syscall.RawConn, network string, address string, finder InterfaceFinder, interfaceName string, interfaceIndex int, preferInterfaceName bool) error {
 	return Raw(conn, func(fd uintptr) error {
-		var err error
-		if !ifIndexDisabled.Load() {
-			if interfaceIndex == -1 {
-				if finder == nil {
-					return os.ErrInvalid
-				}
-				interfaceIndex, err = finder.InterfaceIndexByName(interfaceName)
-				if err != nil {
-					return err
-				}
+		if interfaceIndex != -1 {
+			return unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_BINDTOIFINDEX, interfaceIndex)
+		}
+		if interfaceName == "" {
+			return os.ErrInvalid
+		}
+		if !preferInterfaceName && finder != nil && !ifIndexDisabled.Load() {
+			var err error
+			interfaceIndex, err = finder.InterfaceIndexByName(interfaceName)
+			if err != nil {
+				return err
 			}
 			err = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_BINDTOIFINDEX, interfaceIndex)
 			if err == nil {
@@ -34,15 +35,6 @@ func bindToInterface(conn syscall.RawConn, network string, address string, finde
 				return err
 			}
 		}
-		if interfaceName == "" {
-			if finder == nil {
-				return os.ErrInvalid
-			}
-			interfaceName, err = finder.InterfaceNameByIndex(interfaceIndex)
-			if err != nil {
-				return err
-			}
-		}
 		return unix.BindToDevice(int(fd), interfaceName)
 	})
 }

common/control/bind_other.go

@@ -4,6 +4,6 @@ package control
 
 import "syscall"
 
-func bindToInterface(conn syscall.RawConn, network string, address string, finder InterfaceFinder, interfaceName string, interfaceIndex int) error {
+func bindToInterface(conn syscall.RawConn, network string, address string, finder InterfaceFinder, interfaceName string, interfaceIndex int, preferInterfaceName bool) error {
 	return nil
 }

common/control/bind_windows.go

@@ -9,7 +9,7 @@ import (
 	M "github.com/sagernet/sing/common/metadata"
 )
 
-func bindToInterface(conn syscall.RawConn, network string, address string, finder InterfaceFinder, interfaceName string, interfaceIndex int) error {
+func bindToInterface(conn syscall.RawConn, network string, address string, finder InterfaceFinder, interfaceName string, interfaceIndex int, preferInterfaceName bool) error {
 	return Raw(conn, func(fd uintptr) error {
 		var err error
 		if interfaceIndex == -1 {