1 /*
   2  * Copyright (c) 2014, 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.net;
  27 
  28 import java.io.FileDescriptor;
  29 import java.net.SocketException;
  30 import java.net.SocketOption;
  31 import java.security.AccessController;
  32 import java.security.PrivilegedAction;
  33 import java.util.Collections;
  34 import java.util.Set;
  35 import jdk.internal.misc.JavaIOFileDescriptorAccess;
  36 import jdk.internal.misc.SharedSecrets;
  37 
  38 /**
  39  * Defines extended socket options, beyond those defined in
  40  * {@link java.net.StandardSocketOptions}. These options may be platform
  41  * specific.
  42  *
  43  * @since 1.8
  44  */
  45 public final class ExtendedSocketOptions {
  46 
  47     private static class ExtSocketOption<T> implements SocketOption<T> {
  48         private final String name;
  49         private final Class<T> type;
  50         ExtSocketOption(String name, Class<T> type) {
  51             this.name = name;
  52             this.type = type;
  53         }
  54         @Override public String name() { return name; }
  55         @Override public Class<T> type() { return type; }
  56         @Override public String toString() { return name; }
  57     }
  58 
  59     private ExtendedSocketOptions() { }
  60 
  61     /**
  62      * Service level properties. When a security manager is installed,
  63      * setting or getting this option requires a {@link NetworkPermission}
  64      * {@code ("setOption.SO_FLOW_SLA")} or {@code "getOption.SO_FLOW_SLA"}
  65      * respectively.
  66      */
  67     public static final SocketOption<SocketFlow> SO_FLOW_SLA = new
  68         ExtSocketOption<SocketFlow>("SO_FLOW_SLA", SocketFlow.class);
  69 
  70 
  71     /**
  72      * SO_QUICKACK.
  73      *
  74      * The value of this socket option is a {@code Boolean} that represents
  75      * whether the option is enabled or disabled. The socket option is specific
  76      * to stream-oriented sockets using the TCP/IP protocol.
  77      *
  78      * The exact semantics of this socket option are socket type and system
  79      * dependent.
  80      *
  81      * This socket option usually enable TCP_QUICKACK mode if set or disable
  82      * TCP_QUICKACK mode if cleared.
  83      *
  84      * When TCP_QUICKACK is enabled, acks are sent immediately, rather than
  85      * delayed if needed in accordance to normal TCP operation.This flag is not
  86      * permanent, it only enables a switch to or from TCP_QUICKACK mode.
  87      *
  88      * Subsequent operation of the TCP protocol will once again enter/leave
  89      * TCP_QUICKACK mode depending on internal protocol processing and factors
  90      * such as delayed ack timeouts occurring and data transfer.
  91      *
  92      * @since 10
  93      */
  94     public static final SocketOption<Boolean> SO_QUICKACK
  95             = new ExtSocketOption<Boolean>("SO_QUICKACK", Boolean.class);
  96     
  97     private static final PlatformSocketOptions platformSocketOptions =
  98             PlatformSocketOptions.get();
  99 
 100     private static final boolean flowSupported =
 101             platformSocketOptions.flowSupported();
 102     private static final boolean quickAckSupported =
 103             platformSocketOptions.quickAckSupported();
 104 
 105     private static final Set<SocketOption<?>> extendedOptions = options();
 106 
 107     static Set<SocketOption<?>> options() {
 108         if (flowSupported) {
 109             if (quickAckSupported) {
 110                 return Set.of(SO_FLOW_SLA, SO_QUICKACK);
 111             } else {
 112                 return Set.of(SO_FLOW_SLA);
 113             }
 114         } else if (quickAckSupported) {
 115             return Set.of(SO_QUICKACK);
 116         } else {
 117             return Collections.<SocketOption<?>>emptySet();
 118         }
 119     }
 120 
 121     static {
 122         // Registers the extended socket options with the base module.
 123         sun.net.ext.ExtendedSocketOptions.register(
 124                 new sun.net.ext.ExtendedSocketOptions(extendedOptions) {
 125 
 126             @Override
 127             public void setOption(FileDescriptor fd,
 128                                   SocketOption<?> option,
 129                                   Object value)
 130                 throws SocketException
 131             {
 132                 SecurityManager sm = System.getSecurityManager();
 133                 if (sm != null)
 134                     sm.checkPermission(new NetworkPermission("setOption." + option.name()));
 135 
 136                 if (fd == null || !fd.valid())
 137                     throw new SocketException("socket closed");
 138 
 139                 if (option == SO_FLOW_SLA) {
 140                     assert flowSupported;
 141                     SocketFlow flow = checkValueType(value, option.type());
 142                     setFlowOption(fd, flow);
 143                 } else if (option == SO_QUICKACK) {
 144                     assert quickAckSupported;
 145                     setQuickAckOption(fd, (boolean)value);
 146                 } else {
 147                     throw new InternalError("Unexpected option " + option);
 148                 }
 149             }
 150 
 151             @Override
 152             public Object getOption(FileDescriptor fd,
 153                                     SocketOption<?> option)
 154                 throws SocketException
 155             {
 156                 SecurityManager sm = System.getSecurityManager();
 157                 if (sm != null)
 158                     sm.checkPermission(new NetworkPermission("getOption." + option.name()));
 159 
 160                 if (fd == null || !fd.valid())
 161                     throw new SocketException("socket closed");
 162 
 163                 if (option == SO_FLOW_SLA) {
 164                     assert flowSupported;
 165                     SocketFlow flow = SocketFlow.create();
 166                     getFlowOption(fd, flow);
 167                     return flow;
 168                 } else if (option == SO_QUICKACK) {
 169                     return getQuickAckOption(fd);
 170                 } else {
 171                     throw new InternalError("Unexpected option " + option);
 172                 }
 173             }
 174         });
 175     }
 176 
 177     @SuppressWarnings("unchecked")
 178     private static <T> T checkValueType(Object value, Class<?> type) {
 179         if (!type.isAssignableFrom(value.getClass())) {
 180             String s = "Found: " + value.getClass() + ", Expected: " + type;
 181             throw new IllegalArgumentException(s);
 182         }
 183         return (T) value;
 184     }
 185 
 186     private static final JavaIOFileDescriptorAccess fdAccess =
 187             SharedSecrets.getJavaIOFileDescriptorAccess();
 188 
 189     private static void setFlowOption(FileDescriptor fd, SocketFlow f)
 190         throws SocketException
 191     {
 192         int status = platformSocketOptions.setFlowOption(fdAccess.get(fd),
 193                                                          f.priority(),
 194                                                          f.bandwidth());
 195         f.status(status);  // augment the given flow with the status
 196     }
 197 
 198     private static void getFlowOption(FileDescriptor fd, SocketFlow f)
 199             throws SocketException {
 200         int status = platformSocketOptions.getFlowOption(fdAccess.get(fd), f);
 201         f.status(status);  // augment the given flow with the status
 202     }
 203 
 204     private static void setQuickAckOption(FileDescriptor fd, boolean on)
 205             throws SocketException {
 206         platformSocketOptions.setQuickAck(fdAccess.get(fd), on == true ? 1 : 0);
 207     }
 208 
 209     private static Object getQuickAckOption(FileDescriptor fd)
 210             throws SocketException {
 211         return platformSocketOptions.getQuickAck(fdAccess.get(fd));
 212     }
 213     
 214     static class PlatformSocketOptions {
 215 
 216         protected PlatformSocketOptions() {}
 217 
 218         @SuppressWarnings("unchecked")
 219         private static PlatformSocketOptions newInstance(String cn) {
 220             Class<PlatformSocketOptions> c;
 221             try {
 222                 c = (Class<PlatformSocketOptions>)Class.forName(cn);
 223                 return c.getConstructor(new Class<?>[] { }).newInstance();
 224             } catch (ReflectiveOperationException x) {
 225                 throw new AssertionError(x);
 226             }
 227         }
 228 
 229         private static PlatformSocketOptions create() {
 230             String osname = AccessController.doPrivileged(
 231                     new PrivilegedAction<String>() {
 232                         public String run() {
 233                             return System.getProperty("os.name");
 234                         }
 235                     });
 236             if ("SunOS".equals(osname)) {
 237                 return newInstance("jdk.net.SolarisSocketOptions");
 238             } else if ("Linux".equals(osname)) {
 239                 return newInstance("jdk.net.LinuxSocketOptions");
 240             } else {
 241                 return new PlatformSocketOptions();
 242             }
 243         }
 244 
 245         private static final PlatformSocketOptions instance = create();
 246 
 247         static PlatformSocketOptions get() {
 248             return instance;
 249         }
 250 
 251         int setFlowOption(int fd, int priority, long bandwidth)
 252             throws SocketException
 253         {
 254             throw new UnsupportedOperationException("unsupported socket option");
 255         }
 256 
 257         int getFlowOption(int fd, SocketFlow f) throws SocketException {
 258             throw new UnsupportedOperationException("unsupported socket option");
 259         }
 260 
 261         boolean flowSupported() {
 262             return false;
 263         }
 264         
 265         void setQuickAck(int fd, int on) throws SocketException {
 266             throw new UnsupportedOperationException("unsupported socket option");
 267         }
 268 
 269         Object getQuickAck(int fd) throws SocketException {
 270             throw new UnsupportedOperationException("unsupported socket option");
 271         }
 272 
 273         boolean quickAckSupported() {
 274             return false;
 275         }
 276     }
 277 }