1 /*

     2  * Copyright (c) 2019, 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 jdk.dns.client.internal;

    27 

    28 final class PortConfig {

    29     /**

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

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

    32      * of the OS are returned.

    33      */

    34     private static int defaultUpper, defaultLower;

    35     private static final int upper, lower;

    36 

    37     private PortConfig() {

    38     }

    39 

    40     static {

    41         String os = System.getProperty("os.name");

    42         if (os.startsWith("Linux")) {

    43             defaultLower = 32768;

    44             defaultUpper = 61000;

    45         } else if (os.startsWith("SunOS")) {

    46             defaultLower = 32768;

    47             defaultUpper = 65535;

    48         } else if (os.contains("OS X")) {

    49             defaultLower = 49152;

    50             defaultUpper = 65535;

    51         } else if (os.startsWith("AIX")) {

    52             // The ephemeral port is OS version dependent on AIX:

    53             // http://publib.boulder.ibm.com/infocenter/aix/v7r1/topic/com.ibm.aix.rsct315.admin/bl503_ephport.htm

    54             // However, on AIX 5.3 / 6.1 / 7.1 we always see the

    55             // settings below by using:

    56             // /usr/sbin/no -a | fgrep ephemeral

    57             defaultLower = 32768;

    58             defaultUpper = 65535;

    59         } else {

    60             throw new InternalError(

    61                     "sun.net.PortConfig: unknown OS");

    62         }

    63 

    64         lower = defaultLower;

    65         upper = defaultUpper;

    66     }

    67 

    68     public static int getLower() {

    69         return lower;

    70     }

    71 

    72     public static int getUpper() {

    73         return upper;

    74     }

    75 }