Sockopt: Use Windows syscall (XTLS#4581)

(cherry picked from commit 78a1e37)

Author: xqzr

transport/internet/sockopt_windows.go

@@ -13,9 +13,6 @@ const (
 	TCP_FASTOPEN    = 15
 	IP_UNICAST_IF   = 31
 	IPV6_UNICAST_IF = 31
-	IP_MULTICAST_IF = 9
-	IPV6_MULTICAST_IF = 9
-	IPV6_V6ONLY = 27
 )
 
 func setTFO(fd syscall.Handle, tfo int) error {
@@ -44,14 +41,14 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IP, IP_UNICAST_IF, int(idx)); err != nil {
 				return errors.New("failed to set IP_UNICAST_IF").Base(err)
 			}
-			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IP, IP_MULTICAST_IF, int(idx)); err != nil {
+			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IP, syscall.IP_MULTICAST_IF, int(idx)); err != nil {
 				return errors.New("failed to set IP_MULTICAST_IF").Base(err)
 			}
 		} else {
 			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IPV6, IPV6_UNICAST_IF, inf.Index); err != nil {
 				return errors.New("failed to set IPV6_UNICAST_IF").Base(err)
 			}
-			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IPV6, IPV6_MULTICAST_IF, inf.Index); err != nil {
+			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IPV6, syscall.IPV6_MULTICAST_IF, inf.Index); err != nil {
 				return errors.New("failed to set IPV6_MULTICAST_IF").Base(err)
 			}
 		}
@@ -92,7 +89,7 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 	}
 
 	if config.V6Only {
-		if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IPV6, IPV6_V6ONLY, 1); err != nil {
+		if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IPV6, syscall.IPV6_V6ONLY, 1); err != nil {
 			return errors.New("failed to set IPV6_V6ONLY").Base(err)
 		}
 	}