1 /*

     2  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package sun.net;

    27 

    28 import java.security.AccessController;

    29 

    30 /**

    31  * Determines the ephemeral port range in use on this system.

    32  * If this cannot be determined, then the default settings

    33  * of the OS are returned.

    34  */

    35 

    36 public final class PortConfig {

    37 

    38     private static int defaultUpper, defaultLower;

    39     private final static int upper, lower;

    40 

    41     static {

    42         AccessController.doPrivileged(

    43             new java.security.PrivilegedAction<Void>() {

    44                 public Void run() {

    45                     System.loadLibrary("net");

    46                     return null;

    47                 }

    48             });

    49 

    50         int v = getLower0();

    51         if (v == -1) {

    52             v = defaultLower;

    53         }

    54         lower = v;

    55 

    56         v = getUpper0();

    57         if (v == -1) {

    58             v = defaultUpper;

    59         }

    60         upper = v;

    61     }

    62 

    63     static native int getLower0();

    64     static native int getUpper0();

    65 

    66     public static int getLower() {

    67         return lower;

    68     }

    69 

    70     public static int getUpper() {

    71         return upper;

    72     }

    73 }