1 /*
2 * Copyright (c) 1995, 2010, 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 java.net;
27
28 import java.io.IOException;
29 import java.io.InputStream;
30 import java.io.OutputStream;
31 import java.io.FileDescriptor;
32
33 import sun.net.ConnectionResetException;
34 import sun.net.NetHooks;
35
36 /**
37 * Default Socket Implementation. This implementation does
38 * not implement any security checks.
39 * Note this class should <b>NOT</b> be public.
40 *
41 * @author Steven B. Byrne
42 */
43 abstract class AbstractPlainSocketImpl extends SocketImpl
44 {
45 /* instance variable for SO_TIMEOUT */
46 int timeout; // timeout in millisec
47 // traffic class
48 private int trafficClass;
49
50 private boolean shut_rd = false;
51 private boolean shut_wr = false;
52
53 private SocketInputStream socketInputStream = null;
54
55 /* number of threads using the FileDescriptor */
56 protected int fdUseCount = 0;
57
58 /* lock when increment/decrementing fdUseCount */
59 protected final Object fdLock = new Object();
60
61 /* indicates a close is pending on the file descriptor */
62 protected boolean closePending = false;
63
64 /* indicates connection reset state */
65 private int CONNECTION_NOT_RESET = 0;
66 private int CONNECTION_RESET_PENDING = 1;
67 private int CONNECTION_RESET = 2;
68 private int resetState;
69 private final Object resetLock = new Object();
70
71 /**
72 * Load net library into runtime.
73 */
74 static {
75 java.security.AccessController.doPrivileged(
76 new sun.security.action.LoadLibraryAction("net"));
77 }
78
79 /**
80 * Creates a socket with a boolean that specifies whether this
81 * is a stream socket (true) or an unconnected UDP socket (false).
82 */
83 protected synchronized void create(boolean stream) throws IOException {
84 fd = new FileDescriptor();
85 socketCreate(stream);
86 if (socket != null)
87 socket.setCreated();
88 if (serverSocket != null)
89 serverSocket.setCreated();
90 }
91
92 /**
93 * Creates a socket and connects it to the specified port on
94 * the specified host.
95 * @param host the specified host
96 * @param port the specified port
97 */
98 protected void connect(String host, int port)
99 throws UnknownHostException, IOException
100 {
101 boolean connected = false;
102 try {
103 InetAddress address = InetAddress.getByName(host);
104 this.port = port;
105 this.address = address;
106
107 connectToAddress(address, port, timeout);
108 connected = true;
109 } finally {
110 if (!connected) {
111 try {
112 close();
113 } catch (IOException ioe) {
114 /* Do nothing. If connect threw an exception then
115 it will be passed up the call stack */
116 }
117 }
118 }
119 }
120
121 /**
122 * Creates a socket and connects it to the specified address on
123 * the specified port.
124 * @param address the address
125 * @param port the specified port
126 */
127 protected void connect(InetAddress address, int port) throws IOException {
128 this.port = port;
129 this.address = address;
130
131 try {
132 connectToAddress(address, port, timeout);
133 return;
134 } catch (IOException e) {
135 // everything failed
136 close();
137 throw e;
138 }
139 }
140
141 /**
142 * Creates a socket and connects it to the specified address on
143 * the specified port.
144 * @param address the address
145 * @param timeout the timeout value in milliseconds, or zero for no timeout.
146 * @throws IOException if connection fails
147 * @throws IllegalArgumentException if address is null or is a
148 * SocketAddress subclass not supported by this socket
149 * @since 1.4
150 */
151 protected void connect(SocketAddress address, int timeout)
152 throws IOException {
153 boolean connected = false;
154 try {
155 if (address == null || !(address instanceof InetSocketAddress))
156 throw new IllegalArgumentException("unsupported address type");
157 InetSocketAddress addr = (InetSocketAddress) address;
158 if (addr.isUnresolved())
159 throw new UnknownHostException(addr.getHostName());
160 this.port = addr.getPort();
161 this.address = addr.getAddress();
162
163 connectToAddress(this.address, port, timeout);
164 connected = true;
165 } finally {
166 if (!connected) {
167 try {
168 close();
169 } catch (IOException ioe) {
170 /* Do nothing. If connect threw an exception then
171 it will be passed up the call stack */
172 }
173 }
174 }
175 }
176
177 private void connectToAddress(InetAddress address, int port, int timeout) throws IOException {
178 if (address.isAnyLocalAddress()) {
179 doConnect(InetAddress.getLocalHost(), port, timeout);
180 } else {
181 doConnect(address, port, timeout);
182 }
183 }
184
185 public void setOption(int opt, Object val) throws SocketException {
186 if (isClosedOrPending()) {
187 throw new SocketException("Socket Closed");
188 }
189 boolean on = true;
190 switch (opt) {
191 /* check type safety b4 going native. These should never
192 * fail, since only java.Socket* has access to
193 * PlainSocketImpl.setOption().
194 */
195 case SO_LINGER:
196 if (val == null || (!(val instanceof Integer) && !(val instanceof Boolean)))
197 throw new SocketException("Bad parameter for option");
198 if (val instanceof Boolean) {
199 /* true only if disabling - enabling should be Integer */
200 on = false;
201 }
202 break;
203 case SO_TIMEOUT:
204 if (val == null || (!(val instanceof Integer)))
205 throw new SocketException("Bad parameter for SO_TIMEOUT");
206 int tmp = ((Integer) val).intValue();
207 if (tmp < 0)
208 throw new IllegalArgumentException("timeout < 0");
209 timeout = tmp;
210 break;
211 case IP_TOS:
212 if (val == null || !(val instanceof Integer)) {
213 throw new SocketException("bad argument for IP_TOS");
214 }
215 trafficClass = ((Integer)val).intValue();
216 break;
217 case SO_BINDADDR:
218 throw new SocketException("Cannot re-bind socket");
219 case TCP_NODELAY:
220 if (val == null || !(val instanceof Boolean))
221 throw new SocketException("bad parameter for TCP_NODELAY");
222 on = ((Boolean)val).booleanValue();
223 break;
224 case SO_SNDBUF:
225 case SO_RCVBUF:
226 if (val == null || !(val instanceof Integer) ||
227 !(((Integer)val).intValue() > 0)) {
228 throw new SocketException("bad parameter for SO_SNDBUF " +
229 "or SO_RCVBUF");
230 }
231 break;
232 case SO_KEEPALIVE:
233 if (val == null || !(val instanceof Boolean))
234 throw new SocketException("bad parameter for SO_KEEPALIVE");
235 on = ((Boolean)val).booleanValue();
236 break;
237 case SO_OOBINLINE:
238 if (val == null || !(val instanceof Boolean))
239 throw new SocketException("bad parameter for SO_OOBINLINE");
240 on = ((Boolean)val).booleanValue();
241 break;
242 case SO_REUSEADDR:
243 if (val == null || !(val instanceof Boolean))
244 throw new SocketException("bad parameter for SO_REUSEADDR");
245 on = ((Boolean)val).booleanValue();
246 break;
247 default:
248 throw new SocketException("unrecognized TCP option: " + opt);
249 }
250 socketSetOption(opt, on, val);
251 }
252 public Object getOption(int opt) throws SocketException {
253 if (isClosedOrPending()) {
254 throw new SocketException("Socket Closed");
255 }
256 if (opt == SO_TIMEOUT) {
257 return new Integer(timeout);
258 }
259 int ret = 0;
260 /*
261 * The native socketGetOption() knows about 3 options.
262 * The 32 bit value it returns will be interpreted according
263 * to what we're asking. A return of -1 means it understands
264 * the option but its turned off. It will raise a SocketException
265 * if "opt" isn't one it understands.
266 */
267
268 switch (opt) {
269 case TCP_NODELAY:
270 ret = socketGetOption(opt, null);
271 return Boolean.valueOf(ret != -1);
272 case SO_OOBINLINE:
273 ret = socketGetOption(opt, null);
274 return Boolean.valueOf(ret != -1);
275 case SO_LINGER:
276 ret = socketGetOption(opt, null);
277 return (ret == -1) ? Boolean.FALSE: (Object)(new Integer(ret));
278 case SO_REUSEADDR:
279 ret = socketGetOption(opt, null);
280 return Boolean.valueOf(ret != -1);
281 case SO_BINDADDR:
282 InetAddressContainer in = new InetAddressContainer();
283 ret = socketGetOption(opt, in);
284 return in.addr;
285 case SO_SNDBUF:
286 case SO_RCVBUF:
287 ret = socketGetOption(opt, null);
288 return new Integer(ret);
289 case IP_TOS:
290 ret = socketGetOption(opt, null);
291 if (ret == -1) { // ipv6 tos
292 return new Integer(trafficClass);
293 } else {
294 return new Integer(ret);
295 }
296 case SO_KEEPALIVE:
297 ret = socketGetOption(opt, null);
298 return Boolean.valueOf(ret != -1);
299 // should never get here
300 default:
301 return null;
302 }
303 }
304
305 /**
306 * The workhorse of the connection operation. Tries several times to
307 * establish a connection to the given <host, port>. If unsuccessful,
308 * throws an IOException indicating what went wrong.
309 */
310
311 synchronized void doConnect(InetAddress address, int port, int timeout) throws IOException {
312 synchronized (fdLock) {
313 if (!closePending && (socket == null || !socket.isBound())) {
314 NetHooks.beforeTcpConnect(fd, address, port);
315 }
316 }
317 try {
318 acquireFD();
319 try {
320 socketConnect(address, port, timeout);
321 /* socket may have been closed during poll/select */
322 synchronized (fdLock) {
323 if (closePending) {
324 throw new SocketException ("Socket closed");
325 }
326 }
327 // If we have a ref. to the Socket, then sets the flags
328 // created, bound & connected to true.
329 // This is normally done in Socket.connect() but some
330 // subclasses of Socket may call impl.connect() directly!
331 if (socket != null) {
332 socket.setBound();
333 socket.setConnected();
334 }
335 } finally {
336 releaseFD();
337 }
338 } catch (IOException e) {
339 close();
340 throw e;
341 }
342 }
343
344 /**
345 * Binds the socket to the specified address of the specified local port.
346 * @param address the address
347 * @param port the port
348 */
349 protected synchronized void bind(InetAddress address, int lport)
350 throws IOException
351 {
352 synchronized (fdLock) {
353 if (!closePending && (socket == null || !socket.isBound())) {
354 NetHooks.beforeTcpBind(fd, address, lport);
355 }
356 }
357 socketBind(address, lport);
358 if (socket != null)
359 socket.setBound();
360 if (serverSocket != null)
361 serverSocket.setBound();
362 }
363
364 /**
365 * Listens, for a specified amount of time, for connections.
366 * @param count the amount of time to listen for connections
367 */
368 protected synchronized void listen(int count) throws IOException {
369 socketListen(count);
370 }
371
372 /**
373 * Accepts connections.
374 * @param s the connection
375 */
376 protected void accept(SocketImpl s) throws IOException {
377 acquireFD();
378 try {
379 socketAccept(s);
380 } finally {
381 releaseFD();
382 }
383 }
384
385 /**
386 * Gets an InputStream for this socket.
387 */
388 protected synchronized InputStream getInputStream() throws IOException {
389 if (isClosedOrPending()) {
390 throw new IOException("Socket Closed");
391 }
392 if (shut_rd) {
393 throw new IOException("Socket input is shutdown");
394 }
395 if (socketInputStream == null) {
396 socketInputStream = new SocketInputStream(this);
397 }
398 return socketInputStream;
399 }
400
401 void setInputStream(SocketInputStream in) {
402 socketInputStream = in;
403 }
404
405 /**
406 * Gets an OutputStream for this socket.
407 */
408 protected synchronized OutputStream getOutputStream() throws IOException {
409 if (isClosedOrPending()) {
410 throw new IOException("Socket Closed");
411 }
412 if (shut_wr) {
413 throw new IOException("Socket output is shutdown");
414 }
415 return new SocketOutputStream(this);
416 }
417
418 void setFileDescriptor(FileDescriptor fd) {
419 this.fd = fd;
420 }
421
422 void setAddress(InetAddress address) {
423 this.address = address;
424 }
425
426 void setPort(int port) {
427 this.port = port;
428 }
429
430 void setLocalPort(int localport) {
431 this.localport = localport;
432 }
433
434 /**
435 * Returns the number of bytes that can be read without blocking.
436 */
437 protected synchronized int available() throws IOException {
438 if (isClosedOrPending()) {
439 throw new IOException("Stream closed.");
440 }
441
442 /*
443 * If connection has been reset then return 0 to indicate
444 * there are no buffered bytes.
445 */
446 if (isConnectionReset()) {
447 return 0;
448 }
449
450 /*
451 * If no bytes available and we were previously notified
452 * of a connection reset then we move to the reset state.
453 *
454 * If are notified of a connection reset then check
455 * again if there are bytes buffered on the socket.
456 */
457 int n = 0;
458 try {
459 n = socketAvailable();
460 if (n == 0 && isConnectionResetPending()) {
461 setConnectionReset();
462 }
463 } catch (ConnectionResetException exc1) {
464 setConnectionResetPending();
465 try {
466 n = socketAvailable();
467 if (n == 0) {
468 setConnectionReset();
469 }
470 } catch (ConnectionResetException exc2) {
471 }
472 }
473 return n;
474 }
475
476 /**
477 * Closes the socket.
478 */
479 protected void close() throws IOException {
480 synchronized(fdLock) {
481 if (fd != null) {
482 if (fdUseCount == 0) {
483 if (closePending) {
484 return;
485 }
486 closePending = true;
487 /*
488 * We close the FileDescriptor in two-steps - first the
489 * "pre-close" which closes the socket but doesn't
490 * release the underlying file descriptor. This operation
491 * may be lengthy due to untransmitted data and a long
492 * linger interval. Once the pre-close is done we do the
493 * actual socket to release the fd.
494 */
495 try {
496 socketPreClose();
497 } finally {
498 socketClose();
499 }
500 fd = null;
501 return;
502 } else {
503 /*
504 * If a thread has acquired the fd and a close
505 * isn't pending then use a deferred close.
506 * Also decrement fdUseCount to signal the last
507 * thread that releases the fd to close it.
508 */
509 if (!closePending) {
510 closePending = true;
511 fdUseCount--;
512 socketPreClose();
513 }
514 }
515 }
516 }
517 }
518
519 void reset() throws IOException {
520 if (fd != null) {
521 socketClose();
522 }
523 fd = null;
524 super.reset();
525 }
526
527
528 /**
529 * Shutdown read-half of the socket connection;
530 */
531 protected void shutdownInput() throws IOException {
532 if (fd != null) {
533 socketShutdown(SHUT_RD);
534 if (socketInputStream != null) {
535 socketInputStream.setEOF(true);
536 }
537 shut_rd = true;
538 }
539 }
540
541 /**
542 * Shutdown write-half of the socket connection;
543 */
544 protected void shutdownOutput() throws IOException {
545 if (fd != null) {
546 socketShutdown(SHUT_WR);
547 shut_wr = true;
548 }
549 }
550
551 protected boolean supportsUrgentData () {
552 return true;
553 }
554
555 protected void sendUrgentData (int data) throws IOException {
556 if (fd == null) {
557 throw new IOException("Socket Closed");
558 }
559 socketSendUrgentData (data);
560 }
561
562 /**
563 * Cleans up if the user forgets to close it.
564 */
565 protected void finalize() throws IOException {
566 close();
567 }
568
569 /*
570 * "Acquires" and returns the FileDescriptor for this impl
571 *
572 * A corresponding releaseFD is required to "release" the
573 * FileDescriptor.
574 */
575 FileDescriptor acquireFD() {
576 synchronized (fdLock) {
577 fdUseCount++;
578 return fd;
579 }
580 }
581
582 /*
583 * "Release" the FileDescriptor for this impl.
584 *
585 * If the use count goes to -1 then the socket is closed.
586 */
587 void releaseFD() {
588 synchronized (fdLock) {
589 fdUseCount--;
590 if (fdUseCount == -1) {
591 if (fd != null) {
592 try {
593 socketClose();
594 } catch (IOException e) {
595 } finally {
596 fd = null;
597 }
598 }
599 }
600 }
601 }
602
603 public boolean isConnectionReset() {
604 synchronized (resetLock) {
605 return (resetState == CONNECTION_RESET);
606 }
607 }
608
609 public boolean isConnectionResetPending() {
610 synchronized (resetLock) {
611 return (resetState == CONNECTION_RESET_PENDING);
612 }
613 }
614
615 public void setConnectionReset() {
616 synchronized (resetLock) {
617 resetState = CONNECTION_RESET;
618 }
619 }
620
621 public void setConnectionResetPending() {
622 synchronized (resetLock) {
623 if (resetState == CONNECTION_NOT_RESET) {
624 resetState = CONNECTION_RESET_PENDING;
625 }
626 }
627
628 }
629
630 /*
631 * Return true if already closed or close is pending
632 */
633 public boolean isClosedOrPending() {
634 /*
635 * Lock on fdLock to ensure that we wait if a
636 * close is in progress.
637 */
638 synchronized (fdLock) {
639 if (closePending || (fd == null)) {
640 return true;
641 } else {
642 return false;
643 }
644 }
645 }
646
647 /*
648 * Return the current value of SO_TIMEOUT
649 */
650 public int getTimeout() {
651 return timeout;
652 }
653
654 /*
655 * "Pre-close" a socket by dup'ing the file descriptor - this enables
656 * the socket to be closed without releasing the file descriptor.
657 */
658 private void socketPreClose() throws IOException {
659 socketClose0(true);
660 }
661
662 /*
663 * Close the socket (and release the file descriptor).
664 */
665 protected void socketClose() throws IOException {
666 socketClose0(false);
667 }
668
669 abstract void socketCreate(boolean isServer) throws IOException;
670 abstract void socketConnect(InetAddress address, int port, int timeout)
671 throws IOException;
672 abstract void socketBind(InetAddress address, int port)
673 throws IOException;
674 abstract void socketListen(int count)
675 throws IOException;
676 abstract void socketAccept(SocketImpl s)
677 throws IOException;
678 abstract int socketAvailable()
679 throws IOException;
680 abstract void socketClose0(boolean useDeferredClose)
681 throws IOException;
682 abstract void socketShutdown(int howto)
683 throws IOException;
684 abstract void socketSetOption(int cmd, boolean on, Object value)
685 throws SocketException;
686 abstract int socketGetOption(int opt, Object iaContainerObj) throws SocketException;
687 abstract void socketSendUrgentData(int data)
688 throws IOException;
689
690 public final static int SHUT_RD = 0;
691 public final static int SHUT_WR = 1;
692 }
693
694 class InetAddressContainer {
695 InetAddress addr;
696 }