1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * Copyright (c) 1995, 2013, Oracle and/or its affiliates. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. Oracle designates this 9 * particular file as subject to the "Classpath" exception as provided 10 * by Oracle in the LICENSE file that accompanied this code. 11 * 12 * This code is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 * version 2 for more details (a copy is included in the LICENSE file that 16 * accompanied this code). 17 * 18 * You should have received a copy of the GNU General Public License version 19 * 2 along with this work; if not, write to the Free Software Foundation, 20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 21 * 22 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 23 * or visit www.oracle.com if you need additional information or have any 24 * questions. 25 */ 26 27 package java.net; 28 29 import java.io.IOException; 30 import java.io.InputStream; 31 import java.io.OutputStream; 32 import java.io.FileDescriptor; 33 34 /** 35 * The abstract class {@code SocketImpl} is a common superclass 36 * of all classes that actually implement sockets. It is used to 37 * create both client and server sockets. 38 * <p> 39 * A "plain" socket implements these methods exactly as 40 * described, without attempting to go through a firewall or proxy. 41 * 42 * @author unascribed 43 * @since JDK1.0 44 */ 45 public abstract class SocketImpl implements SocketOptions { 46 /** 47 * The actual Socket object. 48 */ 49 Socket socket = null; 50 ServerSocket serverSocket = null; 51 52 /** 53 * The file descriptor object for this socket. 54 */ 55 protected FileDescriptor fd; 56 57 /** 58 * The IP address of the remote end of this socket. 59 */ 60 protected InetAddress address; 61 62 /** 63 * The port number on the remote host to which this socket is connected. 64 */ 65 protected int port; 66 67 /** 68 * The local port number to which this socket is connected. 69 */ 70 protected int localport; 71 72 /** 73 * Creates either a stream or a datagram socket. 74 * 75 * @param stream if {@code true}, create a stream socket; 76 * otherwise, create a datagram socket. 77 * @exception IOException if an I/O error occurs while creating the 78 * socket. 79 */ create(boolean stream)80 protected abstract void create(boolean stream) throws IOException; 81 82 /** 83 * Connects this socket to the specified port on the named host. 84 * 85 * @param host the name of the remote host. 86 * @param port the port number. 87 * @exception IOException if an I/O error occurs when connecting to the 88 * remote host. 89 */ connect(String host, int port)90 protected abstract void connect(String host, int port) throws IOException; 91 92 /** 93 * Connects this socket to the specified port number on the specified host. 94 * 95 * @param address the IP address of the remote host. 96 * @param port the port number. 97 * @exception IOException if an I/O error occurs when attempting a 98 * connection. 99 */ connect(InetAddress address, int port)100 protected abstract void connect(InetAddress address, int port) throws IOException; 101 102 /** 103 * Connects this socket to the specified port number on the specified host. 104 * A timeout of zero is interpreted as an infinite timeout. The connection 105 * will then block until established or an error occurs. 106 * 107 * @param address the Socket address of the remote host. 108 * @param timeout the timeout value, in milliseconds, or zero for no timeout. 109 * @exception IOException if an I/O error occurs when attempting a 110 * connection. 111 * @since 1.4 112 */ connect(SocketAddress address, int timeout)113 protected abstract void connect(SocketAddress address, int timeout) throws IOException; 114 115 /** 116 * Binds this socket to the specified local IP address and port number. 117 * 118 * @param host an IP address that belongs to a local interface. 119 * @param port the port number. 120 * @exception IOException if an I/O error occurs when binding this socket. 121 */ bind(InetAddress host, int port)122 protected abstract void bind(InetAddress host, int port) throws IOException; 123 124 /** 125 * Sets the maximum queue length for incoming connection indications 126 * (a request to connect) to the {@code count} argument. If a 127 * connection indication arrives when the queue is full, the 128 * connection is refused. 129 * 130 * @param backlog the maximum length of the queue. 131 * @exception IOException if an I/O error occurs when creating the queue. 132 */ listen(int backlog)133 protected abstract void listen(int backlog) throws IOException; 134 135 /** 136 * Accepts a connection. 137 * 138 * @param s the accepted connection. 139 * @exception IOException if an I/O error occurs when accepting the 140 * connection. 141 */ accept(SocketImpl s)142 protected abstract void accept(SocketImpl s) throws IOException; 143 144 /** 145 * Returns an input stream for this socket. 146 * 147 * @return a stream for reading from this socket. 148 * @exception IOException if an I/O error occurs when creating the 149 * input stream. 150 */ getInputStream()151 protected abstract InputStream getInputStream() throws IOException; 152 153 /** 154 * Returns an output stream for this socket. 155 * 156 * @return an output stream for writing to this socket. 157 * @exception IOException if an I/O error occurs when creating the 158 * output stream. 159 */ getOutputStream()160 protected abstract OutputStream getOutputStream() throws IOException; 161 162 /** 163 * Returns the number of bytes that can be read from this socket 164 * without blocking. 165 * 166 * @return the number of bytes that can be read from this socket 167 * without blocking. 168 * @exception IOException if an I/O error occurs when determining the 169 * number of bytes available. 170 */ available()171 protected abstract int available() throws IOException; 172 173 /** 174 * Closes this socket. 175 * 176 * @exception IOException if an I/O error occurs when closing this socket. 177 */ close()178 protected abstract void close() throws IOException; 179 180 /** 181 * Places the input stream for this socket at "end of stream". 182 * Any data sent to this socket is acknowledged and then 183 * silently discarded. 184 * 185 * If you read from a socket input stream after invoking this method on the 186 * socket, the stream's {@code available} method will return 0, and its 187 * {@code read} methods will return {@code -1} (end of stream). 188 * 189 * @exception IOException if an I/O error occurs when shutting down this 190 * socket. 191 * @see java.net.Socket#shutdownOutput() 192 * @see java.net.Socket#close() 193 * @see java.net.Socket#setSoLinger(boolean, int) 194 * @since 1.3 195 */ shutdownInput()196 protected void shutdownInput() throws IOException { 197 throw new IOException("Method not implemented!"); 198 } 199 200 /** 201 * Disables the output stream for this socket. 202 * For a TCP socket, any previously written data will be sent 203 * followed by TCP's normal connection termination sequence. 204 * 205 * If you write to a socket output stream after invoking 206 * shutdownOutput() on the socket, the stream will throw 207 * an IOException. 208 * 209 * @exception IOException if an I/O error occurs when shutting down this 210 * socket. 211 * @see java.net.Socket#shutdownInput() 212 * @see java.net.Socket#close() 213 * @see java.net.Socket#setSoLinger(boolean, int) 214 * @since 1.3 215 */ shutdownOutput()216 protected void shutdownOutput() throws IOException { 217 throw new IOException("Method not implemented!"); 218 } 219 220 /** 221 * Returns the value of this socket's {@code fd} field. 222 * 223 * @return the value of this socket's {@code fd} field. 224 * @see java.net.SocketImpl#fd 225 */ getFileDescriptor()226 protected FileDescriptor getFileDescriptor() { 227 return fd; 228 } 229 230 // Android-added: getFD$() for testing. 231 /** 232 * @hide used by java.nio tests 233 */ getFD$()234 public FileDescriptor getFD$() { 235 return fd; 236 } 237 238 /** 239 * Returns the value of this socket's {@code address} field. 240 * 241 * @return the value of this socket's {@code address} field. 242 * @see java.net.SocketImpl#address 243 */ getInetAddress()244 protected InetAddress getInetAddress() { 245 return address; 246 } 247 248 /** 249 * Returns the value of this socket's {@code port} field. 250 * 251 * @return the value of this socket's {@code port} field. 252 * @see java.net.SocketImpl#port 253 */ getPort()254 protected int getPort() { 255 return port; 256 } 257 258 /** 259 * Returns whether or not this SocketImpl supports sending 260 * urgent data. By default, false is returned 261 * unless the method is overridden in a sub-class 262 * 263 * @return true if urgent data supported 264 * @see java.net.SocketImpl#address 265 * @since 1.4 266 */ supportsUrgentData()267 protected boolean supportsUrgentData () { 268 return false; // must be overridden in sub-class 269 } 270 271 /** 272 * Send one byte of urgent data on the socket. 273 * The byte to be sent is the low eight bits of the parameter 274 * @param data The byte of data to send 275 * @exception IOException if there is an error 276 * sending the data. 277 * @since 1.4 278 */ sendUrgentData(int data)279 protected abstract void sendUrgentData (int data) throws IOException; 280 281 /** 282 * Returns the value of this socket's {@code localport} field. 283 * 284 * @return the value of this socket's {@code localport} field. 285 * @see java.net.SocketImpl#localport 286 */ getLocalPort()287 protected int getLocalPort() { 288 return localport; 289 } 290 setSocket(Socket soc)291 void setSocket(Socket soc) { 292 this.socket = soc; 293 } 294 getSocket()295 Socket getSocket() { 296 return socket; 297 } 298 setServerSocket(ServerSocket soc)299 void setServerSocket(ServerSocket soc) { 300 this.serverSocket = soc; 301 } 302 getServerSocket()303 ServerSocket getServerSocket() { 304 return serverSocket; 305 } 306 307 /** 308 * Returns the address and port of this socket as a {@code String}. 309 * 310 * @return a string representation of this socket. 311 */ toString()312 public String toString() { 313 return "Socket[addr=" + getInetAddress() + 314 ",port=" + getPort() + ",localport=" + getLocalPort() + "]"; 315 } 316 reset()317 void reset() throws IOException { 318 address = null; 319 port = 0; 320 localport = 0; 321 } 322 323 /** 324 * Sets performance preferences for this socket. 325 * 326 * <p> Sockets use the TCP/IP protocol by default. Some implementations 327 * may offer alternative protocols which have different performance 328 * characteristics than TCP/IP. This method allows the application to 329 * express its own preferences as to how these tradeoffs should be made 330 * when the implementation chooses from the available protocols. 331 * 332 * <p> Performance preferences are described by three integers 333 * whose values indicate the relative importance of short connection time, 334 * low latency, and high bandwidth. The absolute values of the integers 335 * are irrelevant; in order to choose a protocol the values are simply 336 * compared, with larger values indicating stronger preferences. Negative 337 * values represent a lower priority than positive values. If the 338 * application prefers short connection time over both low latency and high 339 * bandwidth, for example, then it could invoke this method with the values 340 * {@code (1, 0, 0)}. If the application prefers high bandwidth above low 341 * latency, and low latency above short connection time, then it could 342 * invoke this method with the values {@code (0, 1, 2)}. 343 * 344 * By default, this method does nothing, unless it is overridden in a 345 * a sub-class. 346 * 347 * @param connectionTime 348 * An {@code int} expressing the relative importance of a short 349 * connection time 350 * 351 * @param latency 352 * An {@code int} expressing the relative importance of low 353 * latency 354 * 355 * @param bandwidth 356 * An {@code int} expressing the relative importance of high 357 * bandwidth 358 * 359 * @since 1.5 360 */ setPerformancePreferences(int connectionTime, int latency, int bandwidth)361 protected void setPerformancePreferences(int connectionTime, 362 int latency, 363 int bandwidth) 364 { 365 /* Not implemented yet */ 366 } 367 setOption(SocketOption<T> name, T value)368 <T> void setOption(SocketOption<T> name, T value) throws IOException { 369 if (name == StandardSocketOptions.SO_KEEPALIVE) { 370 setOption(SocketOptions.SO_KEEPALIVE, value); 371 } else if (name == StandardSocketOptions.SO_SNDBUF) { 372 setOption(SocketOptions.SO_SNDBUF, value); 373 } else if (name == StandardSocketOptions.SO_RCVBUF) { 374 setOption(SocketOptions.SO_RCVBUF, value); 375 } else if (name == StandardSocketOptions.SO_REUSEADDR) { 376 setOption(SocketOptions.SO_REUSEADDR, value); 377 } else if (name == StandardSocketOptions.SO_LINGER) { 378 setOption(SocketOptions.SO_LINGER, value); 379 } else if (name == StandardSocketOptions.IP_TOS) { 380 setOption(SocketOptions.IP_TOS, value); 381 } else if (name == StandardSocketOptions.TCP_NODELAY) { 382 setOption(SocketOptions.TCP_NODELAY, value); 383 } else { 384 throw new UnsupportedOperationException("unsupported option"); 385 } 386 } 387 getOption(SocketOption<T> name)388 <T> T getOption(SocketOption<T> name) throws IOException { 389 if (name == StandardSocketOptions.SO_KEEPALIVE) { 390 return (T)getOption(SocketOptions.SO_KEEPALIVE); 391 } else if (name == StandardSocketOptions.SO_SNDBUF) { 392 return (T)getOption(SocketOptions.SO_SNDBUF); 393 } else if (name == StandardSocketOptions.SO_RCVBUF) { 394 return (T)getOption(SocketOptions.SO_RCVBUF); 395 } else if (name == StandardSocketOptions.SO_REUSEADDR) { 396 return (T)getOption(SocketOptions.SO_REUSEADDR); 397 } else if (name == StandardSocketOptions.SO_LINGER) { 398 return (T)getOption(SocketOptions.SO_LINGER); 399 } else if (name == StandardSocketOptions.IP_TOS) { 400 return (T)getOption(SocketOptions.IP_TOS); 401 } else if (name == StandardSocketOptions.TCP_NODELAY) { 402 return (T)getOption(SocketOptions.TCP_NODELAY); 403 } else { 404 throw new UnsupportedOperationException("unsupported option"); 405 } 406 } 407 } 408