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     private PortConfig() {}
  42 
  43     static {
  44         AccessController.doPrivileged(
  45             new java.security.PrivilegedAction<Void>() {
  46                 public Void run() {
  47                     System.loadLibrary("net");
  48                     String os = System.getProperty("os.name");
  49                     if (os.startsWith("Linux")) {
  50                         defaultLower = 32768;
  51                         defaultUpper = 61000;
  52                     } else if (os.startsWith("SunOS")) {
  53                         defaultLower = 32768;
  54                         defaultUpper = 65535;
  55                     } else if (os.contains("OS X")) {
  56                         defaultLower = 49152;
  57                         defaultUpper = 65535;
  58                     } else {
  59                         throw new InternalError(
  60                             "sun.net.PortConfig: unknown OS");
  61                     }
  62                     return null;
  63                 }
  64             });
  65 
  66         int v = getLower0();
  67         if (v == -1) {
  68             v = defaultLower;
  69         }
  70         lower = v;
  71 
  72         v = getUpper0();
  73         if (v == -1) {
  74             v = defaultUpper;
  75         }
  76         upper = v;
  77     }
  78 
  79     static native int getLower0();
  80     static native int getUpper0();
  81 
  82     public static int getLower() {
  83         return lower;
  84     }
  85 
  86     public static int getUpper() {
  87         return upper;
  88     }
  89 }