use IP_PMTUDISC_PROBE instead of IP_PMTUDISC_DO on Linux (#4729)

marten-seemann · marten-seemann · commit 34157e6455b0 · 2024-11-26T12:04:36.000+08:00
diff --git a/sys_conn_df_linux.go b/sys_conn_df_linux.go
@@ -16,8 +16,8 @@ func setDF(rawConn syscall.RawConn) (bool, error) {
 	// and the datagram will not be fragmented
 	var errDFIPv4, errDFIPv6 error
 	if err := rawConn.Control(func(fd uintptr) {
-		errDFIPv4 = unix.SetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_MTU_DISCOVER, unix.IP_PMTUDISC_DO)
-		errDFIPv6 = unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_MTU_DISCOVER, unix.IPV6_PMTUDISC_DO)
+		errDFIPv4 = unix.SetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_MTU_DISCOVER, unix.IP_PMTUDISC_PROBE)
+		errDFIPv6 = unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_MTU_DISCOVER, unix.IPV6_PMTUDISC_PROBE)
 	}); err != nil {
 		return false, err
 	}
