1 /*
   2  * Copyright (c) 2013, 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 sun.net;
  27 
  28 import sun.security.action.GetPropertyAction;
  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 static final int upper, lower;
  40 
  41     private PortConfig() {}
  42 
  43     static {
  44         jdk.internal.access.SharedSecrets.getJavaLangAccess().loadLibrary("net");
  45         String os = GetPropertyAction.privilegedGetProperty("os.name");
  46         if (os.startsWith("Linux")) {
  47             defaultLower = 32768;
  48             defaultUpper = 61000;
  49         } else if (os.startsWith("SunOS")) {
  50             defaultLower = 32768;
  51             defaultUpper = 65535;
  52         } else if (os.contains("OS X")) {
  53             defaultLower = 49152;
  54             defaultUpper = 65535;
  55         } else if (os.startsWith("AIX")) {
  56             // The ephemeral port is OS version dependent on AIX:
  57             // http://publib.boulder.ibm.com/infocenter/aix/v7r1/topic/com.ibm.aix.rsct315.admin/bl503_ephport.htm
  58             // However, on AIX 5.3 / 6.1 / 7.1 we always see the
  59             // settings below by using:
  60             // /usr/sbin/no -a | fgrep ephemeral
  61             defaultLower = 32768;
  62             defaultUpper = 65535;
  63         } else {
  64             throw new InternalError(
  65                 "sun.net.PortConfig: unknown OS");
  66         }
  67 
  68         int v = getLower0();
  69         if (v == -1) {
  70             v = defaultLower;
  71         }
  72         lower = v;
  73 
  74         v = getUpper0();
  75         if (v == -1) {
  76             v = defaultUpper;
  77         }
  78         upper = v;
  79     }
  80 
  81     static native int getLower0();
  82     static native int getUpper0();
  83 
  84     public static int getLower() {
  85         return lower;
  86     }
  87 
  88     public static int getUpper() {
  89         return upper;
  90     }
  91 }