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 186 * shutdownInput() on the socket, the stream will return EOF. 187 * 188 * @exception IOException if an I/O error occurs when shutting down this 189 * socket. 190 * @see java.net.Socket#shutdownOutput() 191 * @see java.net.Socket#close() 192 * @see java.net.Socket#setSoLinger(boolean, int) 193 * @since 1.3 194 */ shutdownInput()195 protected void shutdownInput() throws IOException { 196 throw new IOException("Method not implemented!"); 197 } 198 199 /** 200 * Disables the output stream for this socket. 201 * For a TCP socket, any previously written data will be sent 202 * followed by TCP's normal connection termination sequence. 203 * 204 * If you write to a socket output stream after invoking 205 * shutdownOutput() on the socket, the stream will throw 206 * an IOException. 207 * 208 * @exception IOException if an I/O error occurs when shutting down this 209 * socket. 210 * @see java.net.Socket#shutdownInput() 211 * @see java.net.Socket#close() 212 * @see java.net.Socket#setSoLinger(boolean, int) 213 * @since 1.3 214 */ shutdownOutput()215 protected void shutdownOutput() throws IOException { 216 throw new IOException("Method not implemented!"); 217 } 218 219 /** 220 * Returns the value of this socket's {@code fd} field. 221 * 222 * @return the value of this socket's {@code fd} field. 223 * @see java.net.SocketImpl#fd 224 */ getFileDescriptor()225 protected FileDescriptor getFileDescriptor() { 226 return fd; 227 } 228 229 /** 230 * @hide used by java.nio tests 231 */ getFD$()232 public FileDescriptor getFD$() { 233 return fd; 234 } 235 236 /** 237 * Returns the value of this socket's {@code address} field. 238 * 239 * @return the value of this socket's {@code address} field. 240 * @see java.net.SocketImpl#address 241 */ getInetAddress()242 protected InetAddress getInetAddress() { 243 return address; 244 } 245 246 /** 247 * Returns the value of this socket's {@code port} field. 248 * 249 * @return the value of this socket's {@code port} field. 250 * @see java.net.SocketImpl#port 251 */ getPort()252 protected int getPort() { 253 return port; 254 } 255 256 /** 257 * Returns whether or not this SocketImpl supports sending 258 * urgent data. By default, false is returned 259 * unless the method is overridden in a sub-class 260 * 261 * @return true if urgent data supported 262 * @see java.net.SocketImpl#address 263 * @since 1.4 264 */ supportsUrgentData()265 protected boolean supportsUrgentData () { 266 return false; // must be overridden in sub-class 267 } 268 269 /** 270 * Send one byte of urgent data on the socket. 271 * The byte to be sent is the low eight bits of the parameter 272 * @param data The byte of data to send 273 * @exception IOException if there is an error 274 * sending the data. 275 * @since 1.4 276 */ sendUrgentData(int data)277 protected abstract void sendUrgentData (int data) throws IOException; 278 279 /** 280 * Returns the value of this socket's {@code localport} field. 281 * 282 * @return the value of this socket's {@code localport} field. 283 * @see java.net.SocketImpl#localport 284 */ getLocalPort()285 protected int getLocalPort() { 286 return localport; 287 } 288 setSocket(Socket soc)289 void setSocket(Socket soc) { 290 this.socket = soc; 291 } 292 getSocket()293 Socket getSocket() { 294 return socket; 295 } 296 setServerSocket(ServerSocket soc)297 void setServerSocket(ServerSocket soc) { 298 this.serverSocket = soc; 299 } 300 getServerSocket()301 ServerSocket getServerSocket() { 302 return serverSocket; 303 } 304 305 /** 306 * Returns the address and port of this socket as a {@code String}. 307 * 308 * @return a string representation of this socket. 309 */ toString()310 public String toString() { 311 return "Socket[addr=" + getInetAddress() + 312 ",port=" + getPort() + ",localport=" + getLocalPort() + "]"; 313 } 314 reset()315 void reset() throws IOException { 316 address = null; 317 port = 0; 318 localport = 0; 319 } 320 321 /** 322 * Sets performance preferences for this socket. 323 * 324 * <p> Sockets use the TCP/IP protocol by default. Some implementations 325 * may offer alternative protocols which have different performance 326 * characteristics than TCP/IP. This method allows the application to 327 * express its own preferences as to how these tradeoffs should be made 328 * when the implementation chooses from the available protocols. 329 * 330 * <p> Performance preferences are described by three integers 331 * whose values indicate the relative importance of short connection time, 332 * low latency, and high bandwidth. The absolute values of the integers 333 * are irrelevant; in order to choose a protocol the values are simply 334 * compared, with larger values indicating stronger preferences. Negative 335 * values represent a lower priority than positive values. If the 336 * application prefers short connection time over both low latency and high 337 * bandwidth, for example, then it could invoke this method with the values 338 * {@code (1, 0, 0)}. If the application prefers high bandwidth above low 339 * latency, and low latency above short connection time, then it could 340 * invoke this method with the values {@code (0, 1, 2)}. 341 * 342 * By default, this method does nothing, unless it is overridden in a 343 * a sub-class. 344 * 345 * @param connectionTime 346 * An {@code int} expressing the relative importance of a short 347 * connection time 348 * 349 * @param latency 350 * An {@code int} expressing the relative importance of low 351 * latency 352 * 353 * @param bandwidth 354 * An {@code int} expressing the relative importance of high 355 * bandwidth 356 * 357 * @since 1.5 358 */ setPerformancePreferences(int connectionTime, int latency, int bandwidth)359 protected void setPerformancePreferences(int connectionTime, 360 int latency, 361 int bandwidth) 362 { 363 /* Not implemented yet */ 364 } 365 setOption(SocketOption<T> name, T value)366 <T> void setOption(SocketOption<T> name, T value) throws IOException { 367 if (name == StandardSocketOptions.SO_KEEPALIVE) { 368 setOption(SocketOptions.SO_KEEPALIVE, value); 369 } else if (name == StandardSocketOptions.SO_SNDBUF) { 370 setOption(SocketOptions.SO_SNDBUF, value); 371 } else if (name == StandardSocketOptions.SO_RCVBUF) { 372 setOption(SocketOptions.SO_RCVBUF, value); 373 } else if (name == StandardSocketOptions.SO_REUSEADDR) { 374 setOption(SocketOptions.SO_REUSEADDR, value); 375 } else if (name == StandardSocketOptions.SO_LINGER) { 376 setOption(SocketOptions.SO_LINGER, value); 377 } else if (name == StandardSocketOptions.IP_TOS) { 378 setOption(SocketOptions.IP_TOS, value); 379 } else if (name == StandardSocketOptions.TCP_NODELAY) { 380 setOption(SocketOptions.TCP_NODELAY, value); 381 } else { 382 throw new UnsupportedOperationException("unsupported option"); 383 } 384 } 385 getOption(SocketOption<T> name)386 <T> T getOption(SocketOption<T> name) throws IOException { 387 if (name == StandardSocketOptions.SO_KEEPALIVE) { 388 return (T)getOption(SocketOptions.SO_KEEPALIVE); 389 } else if (name == StandardSocketOptions.SO_SNDBUF) { 390 return (T)getOption(SocketOptions.SO_SNDBUF); 391 } else if (name == StandardSocketOptions.SO_RCVBUF) { 392 return (T)getOption(SocketOptions.SO_RCVBUF); 393 } else if (name == StandardSocketOptions.SO_REUSEADDR) { 394 return (T)getOption(SocketOptions.SO_REUSEADDR); 395 } else if (name == StandardSocketOptions.SO_LINGER) { 396 return (T)getOption(SocketOptions.SO_LINGER); 397 } else if (name == StandardSocketOptions.IP_TOS) { 398 return (T)getOption(SocketOptions.IP_TOS); 399 } else if (name == StandardSocketOptions.TCP_NODELAY) { 400 return (T)getOption(SocketOptions.TCP_NODELAY); 401 } else { 402 throw new UnsupportedOperationException("unsupported option"); 403 } 404 } 405 } 406