1 /*
2 * Copyright (c) 1995, 2011, 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 import sun.net.ResourceManager;
36
37 /**
38 * Default Socket Implementation. This implementation does
39 * not implement any security checks.
40 * Note this class should <b>NOT</b> be public.
41 *
42 * @author Steven B. Byrne
43 */
44 abstract class AbstractPlainSocketImpl extends SocketImpl
45 {
46 /* instance variable for SO_TIMEOUT */
47 int timeout; // timeout in millisec
48 // traffic class
49 private int trafficClass;
50
51 private boolean shut_rd = false;
52 private boolean shut_wr = false;
53
54 private SocketInputStream socketInputStream = null;
55
56 /* number of threads using the FileDescriptor */
57 protected int fdUseCount = 0;
58
59 /* lock when increment/decrementing fdUseCount */
60 protected final Object fdLock = new Object();
61
62 /* indicates a close is pending on the file descriptor */
63 protected boolean closePending = false;
64
65 /* indicates connection reset state */
66 private int CONNECTION_NOT_RESET = 0;
67 private int CONNECTION_RESET_PENDING = 1;
68 private int CONNECTION_RESET = 2;
69 private int resetState;
70 private final Object resetLock = new Object();
71
72 /* whether this Socket is a stream (TCP) socket or not (UDP)
73 */
74 protected boolean stream;
75
76 /**
77 * Load net library into runtime.
78 */
79 static {
80 java.security.AccessController.doPrivileged(
81 new java.security.PrivilegedAction<Void>() {
82 public Void run() {
83 System.loadLibrary("net");
84 return null;
85 }
86 });
87 }
88
89 /**
90 * Creates a socket with a boolean that specifies whether this
91 * is a stream socket (true) or an unconnected UDP socket (false).
92 */
93 protected synchronized void create(boolean stream) throws IOException {
94 this.stream = stream;
95 if (!stream) {
96 ResourceManager.beforeUdpCreate();
97 // only create the fd after we know we will be able to create the socket
98 fd = new FileDescriptor();
99 try {
100 socketCreate(false);
101 } catch (IOException ioe) {
102 ResourceManager.afterUdpClose();
103 fd = null;
104 throw ioe;
105 }
106 } else {
107 fd = new FileDescriptor();
108 socketCreate(true);
109 }
110 if (socket != null)
111 socket.setCreated();
112 if (serverSocket != null)
113 serverSocket.setCreated();
114 }
115
116 /**
117 * Creates a socket and connects it to the specified port on
118 * the specified host.
119 * @param host the specified host
120 * @param port the specified port
121 */
122 protected void connect(String host, int port)
123 throws UnknownHostException, IOException
124 {
125 boolean connected = false;
126 try {
127 InetAddress address = InetAddress.getByName(host);
128 this.port = port;
129 this.address = address;
130
131 connectToAddress(address, port, timeout);
132 connected = true;
133 } finally {
134 if (!connected) {
135 try {
136 close();
137 } catch (IOException ioe) {
138 /* Do nothing. If connect threw an exception then
139 it will be passed up the call stack */
140 }
141 }
142 }
143 }
144
145 /**
146 * Creates a socket and connects it to the specified address on
147 * the specified port.
148 * @param address the address
149 * @param port the specified port
150 */
151 protected void connect(InetAddress address, int port) throws IOException {
152 this.port = port;
153 this.address = address;
154
155 try {
156 connectToAddress(address, port, timeout);
157 return;
158 } catch (IOException e) {
159 // everything failed
160 close();
161 throw e;
162 }
163 }
164
165 /**
166 * Creates a socket and connects it to the specified address on
167 * the specified port.
168 * @param address the address
169 * @param timeout the timeout value in milliseconds, or zero for no timeout.
170 * @throws IOException if connection fails
171 * @throws IllegalArgumentException if address is null or is a
172 * SocketAddress subclass not supported by this socket
173 * @since 1.4
174 */
175 protected void connect(SocketAddress address, int timeout)
176 throws IOException {
177 boolean connected = false;
178 try {
179 if (address == null || !(address instanceof InetSocketAddress))
180 throw new IllegalArgumentException("unsupported address type");
181 InetSocketAddress addr = (InetSocketAddress) address;
182 if (addr.isUnresolved())
183 throw new UnknownHostException(addr.getHostName());
184 this.port = addr.getPort();
185 this.address = addr.getAddress();
186
187 connectToAddress(this.address, port, timeout);
188 connected = true;
189 } finally {
190 if (!connected) {
191 try {
192 close();
193 } catch (IOException ioe) {
194 /* Do nothing. If connect threw an exception then
195 it will be passed up the call stack */
196 }
197 }
198 }
199 }
200
201 private void connectToAddress(InetAddress address, int port, int timeout) throws IOException {
202 if (address.isAnyLocalAddress()) {
203 doConnect(InetAddress.getLocalHost(), port, timeout);
204 } else {
205 doConnect(address, port, timeout);
206 }
207 }
208
209 public void setOption(int opt, Object val) throws SocketException {
210 if (isClosedOrPending()) {
211 throw new SocketException("Socket Closed");
212 }
213 boolean on = true;
214 switch (opt) {
215 /* check type safety b4 going native. These should never
216 * fail, since only java.Socket* has access to
217 * PlainSocketImpl.setOption().
218 */
219 case SO_LINGER:
220 if (val == null || (!(val instanceof Integer) && !(val instanceof Boolean)))
221 throw new SocketException("Bad parameter for option");
222 if (val instanceof Boolean) {
223 /* true only if disabling - enabling should be Integer */
224 on = false;
225 }
226 break;
227 case SO_TIMEOUT:
228 if (val == null || (!(val instanceof Integer)))
229 throw new SocketException("Bad parameter for SO_TIMEOUT");
230 int tmp = ((Integer) val).intValue();
231 if (tmp < 0)
232 throw new IllegalArgumentException("timeout < 0");
233 timeout = tmp;
234 break;
235 case IP_TOS:
236 if (val == null || !(val instanceof Integer)) {
237 throw new SocketException("bad argument for IP_TOS");
238 }
239 trafficClass = ((Integer)val).intValue();
240 break;
241 case SO_BINDADDR:
242 throw new SocketException("Cannot re-bind socket");
243 case TCP_NODELAY:
244 if (val == null || !(val instanceof Boolean))
245 throw new SocketException("bad parameter for TCP_NODELAY");
246 on = ((Boolean)val).booleanValue();
247 break;
248 case SO_SNDBUF:
249 case SO_RCVBUF:
250 if (val == null || !(val instanceof Integer) ||
251 !(((Integer)val).intValue() > 0)) {
252 throw new SocketException("bad parameter for SO_SNDBUF " +
253 "or SO_RCVBUF");
254 }
255 break;
256 case SO_KEEPALIVE:
257 if (val == null || !(val instanceof Boolean))
258 throw new SocketException("bad parameter for SO_KEEPALIVE");
259 on = ((Boolean)val).booleanValue();
260 break;
261 case SO_OOBINLINE:
262 if (val == null || !(val instanceof Boolean))
263 throw new SocketException("bad parameter for SO_OOBINLINE");
264 on = ((Boolean)val).booleanValue();
265 break;
266 case SO_REUSEADDR:
267 if (val == null || !(val instanceof Boolean))
268 throw new SocketException("bad parameter for SO_REUSEADDR");
269 on = ((Boolean)val).booleanValue();
270 break;
271 default:
272 throw new SocketException("unrecognized TCP option: " + opt);
273 }
274 socketSetOption(opt, on, val);
275 }
276 public Object getOption(int opt) throws SocketException {
277 if (isClosedOrPending()) {
278 throw new SocketException("Socket Closed");
279 }
280 if (opt == SO_TIMEOUT) {
281 return new Integer(timeout);
282 }
283 int ret = 0;
284 /*
285 * The native socketGetOption() knows about 3 options.
286 * The 32 bit value it returns will be interpreted according
287 * to what we're asking. A return of -1 means it understands
288 * the option but its turned off. It will raise a SocketException
289 * if "opt" isn't one it understands.
290 */
291
292 switch (opt) {
293 case TCP_NODELAY:
294 ret = socketGetOption(opt, null);
295 return Boolean.valueOf(ret != -1);
296 case SO_OOBINLINE:
297 ret = socketGetOption(opt, null);
298 return Boolean.valueOf(ret != -1);
299 case SO_LINGER:
300 ret = socketGetOption(opt, null);
301 return (ret == -1) ? Boolean.FALSE: (Object)(new Integer(ret));
302 case SO_REUSEADDR:
303 ret = socketGetOption(opt, null);
304 return Boolean.valueOf(ret != -1);
305 case SO_BINDADDR:
306 InetAddressContainer in = new InetAddressContainer();
307 ret = socketGetOption(opt, in);
308 return in.addr;
309 case SO_SNDBUF:
310 case SO_RCVBUF:
311 ret = socketGetOption(opt, null);
312 return new Integer(ret);
313 case IP_TOS:
314 ret = socketGetOption(opt, null);
315 if (ret == -1) { // ipv6 tos
316 return new Integer(trafficClass);
317 } else {
318 return new Integer(ret);
319 }
320 case SO_KEEPALIVE:
321 ret = socketGetOption(opt, null);
322 return Boolean.valueOf(ret != -1);
323 // should never get here
324 default:
325 return null;
326 }
327 }
328
329 /**
330 * The workhorse of the connection operation. Tries several times to
331 * establish a connection to the given <host, port>. If unsuccessful,
332 * throws an IOException indicating what went wrong.
333 */
334
335 synchronized void doConnect(InetAddress address, int port, int timeout) throws IOException {
336 synchronized (fdLock) {
337 if (!closePending && (socket == null || !socket.isBound())) {
338 NetHooks.beforeTcpConnect(fd, address, port);
339 }
340 }
341 try {
342 acquireFD();
343 try {
344 socketConnect(address, port, timeout);
345 /* socket may have been closed during poll/select */
346 synchronized (fdLock) {
347 if (closePending) {
348 throw new SocketException ("Socket closed");
349 }
350 }
351 // If we have a ref. to the Socket, then sets the flags
352 // created, bound & connected to true.
353 // This is normally done in Socket.connect() but some
354 // subclasses of Socket may call impl.connect() directly!
355 if (socket != null) {
356 socket.setBound();
357 socket.setConnected();
358 }
359 } finally {
360 releaseFD();
361 }
362 } catch (IOException e) {
363 close();
364 throw e;
365 }
366 }
367
368 /**
369 * Binds the socket to the specified address of the specified local port.
370 * @param address the address
371 * @param port the port
372 */
373 protected synchronized void bind(InetAddress address, int lport)
374 throws IOException
375 {
376 synchronized (fdLock) {
377 if (!closePending && (socket == null || !socket.isBound())) {
378 NetHooks.beforeTcpBind(fd, address, lport);
379 }
380 }
381 socketBind(address, lport);
382 if (socket != null)
383 socket.setBound();
384 if (serverSocket != null)
385 serverSocket.setBound();
386 }
387
388 /**
389 * Listens, for a specified amount of time, for connections.
390 * @param count the amount of time to listen for connections
391 */
392 protected synchronized void listen(int count) throws IOException {
393 socketListen(count);
394 }
395
396 /**
397 * Accepts connections.
398 * @param s the connection
399 */
400 protected void accept(SocketImpl s) throws IOException {
401 acquireFD();
402 try {
403 socketAccept(s);
404 } finally {
405 releaseFD();
406 }
407 }
408
409 /**
410 * Gets an InputStream for this socket.
411 */
412 protected synchronized InputStream getInputStream() throws IOException {
413 if (isClosedOrPending()) {
414 throw new IOException("Socket Closed");
415 }
416 if (shut_rd) {
417 throw new IOException("Socket input is shutdown");
418 }
419 if (socketInputStream == null) {
420 socketInputStream = new SocketInputStream(this);
421 }
422 return socketInputStream;
423 }
424
425 void setInputStream(SocketInputStream in) {
426 socketInputStream = in;
427 }
428
429 /**
430 * Gets an OutputStream for this socket.
431 */
432 protected synchronized OutputStream getOutputStream() throws IOException {
433 if (isClosedOrPending()) {
434 throw new IOException("Socket Closed");
435 }
436 if (shut_wr) {
437 throw new IOException("Socket output is shutdown");
438 }
439 return new SocketOutputStream(this);
440 }
441
442 void setFileDescriptor(FileDescriptor fd) {
443 this.fd = fd;
444 }
445
446 void setAddress(InetAddress address) {
447 this.address = address;
448 }
449
450 void setPort(int port) {
451 this.port = port;
452 }
453
454 void setLocalPort(int localport) {
455 this.localport = localport;
456 }
457
458 /**
459 * Returns the number of bytes that can be read without blocking.
460 */
461 protected synchronized int available() throws IOException {
462 if (isClosedOrPending()) {
463 throw new IOException("Stream closed.");
464 }
465
466 /*
467 * If connection has been reset or shut down for input, then return 0
468 * to indicate there are no buffered bytes.
469 */
470 if (isConnectionReset() || shut_rd) {
471 return 0;
472 }
473
474 /*
475 * If no bytes available and we were previously notified
476 * of a connection reset then we move to the reset state.
477 *
478 * If are notified of a connection reset then check
479 * again if there are bytes buffered on the socket.
480 */
481 int n = 0;
482 try {
483 n = socketAvailable();
484 if (n == 0 && isConnectionResetPending()) {
485 setConnectionReset();
486 }
487 } catch (ConnectionResetException exc1) {
488 setConnectionResetPending();
489 try {
490 n = socketAvailable();
491 if (n == 0) {
492 setConnectionReset();
493 }
494 } catch (ConnectionResetException exc2) {
495 }
496 }
497 return n;
498 }
499
500 /**
501 * Closes the socket.
502 */
503 protected void close() throws IOException {
504 synchronized(fdLock) {
505 if (fd != null) {
506 if (!stream) {
507 ResourceManager.afterUdpClose();
508 }
509 if (fdUseCount == 0) {
510 if (closePending) {
511 return;
512 }
513 closePending = true;
514 /*
515 * We close the FileDescriptor in two-steps - first the
516 * "pre-close" which closes the socket but doesn't
517 * release the underlying file descriptor. This operation
518 * may be lengthy due to untransmitted data and a long
519 * linger interval. Once the pre-close is done we do the
520 * actual socket to release the fd.
521 */
522 try {
523 socketPreClose();
524 } finally {
525 socketClose();
526 }
527 fd = null;
528 return;
529 } else {
530 /*
531 * If a thread has acquired the fd and a close
532 * isn't pending then use a deferred close.
533 * Also decrement fdUseCount to signal the last
534 * thread that releases the fd to close it.
535 */
536 if (!closePending) {
537 closePending = true;
538 fdUseCount--;
539 socketPreClose();
540 }
541 }
542 }
543 }
544 }
545
546 void reset() throws IOException {
547 if (fd != null) {
548 socketClose();
549 }
550 fd = null;
551 super.reset();
552 }
553
554
555 /**
556 * Shutdown read-half of the socket connection;
557 */
558 protected void shutdownInput() throws IOException {
559 if (fd != null) {
560 socketShutdown(SHUT_RD);
561 if (socketInputStream != null) {
562 socketInputStream.setEOF(true);
563 }
564 shut_rd = true;
565 }
566 }
567
568 /**
569 * Shutdown write-half of the socket connection;
570 */
571 protected void shutdownOutput() throws IOException {
572 if (fd != null) {
573 socketShutdown(SHUT_WR);
574 shut_wr = true;
575 }
576 }
577
578 protected boolean supportsUrgentData () {
579 return true;
580 }
581
582 protected void sendUrgentData (int data) throws IOException {
583 if (fd == null) {
584 throw new IOException("Socket Closed");
585 }
586 socketSendUrgentData (data);
587 }
588
589 /**
590 * Cleans up if the user forgets to close it.
591 */
592 protected void finalize() throws IOException {
593 close();
594 }
595
596 /*
597 * "Acquires" and returns the FileDescriptor for this impl
598 *
599 * A corresponding releaseFD is required to "release" the
600 * FileDescriptor.
601 */
602 FileDescriptor acquireFD() {
603 synchronized (fdLock) {
604 fdUseCount++;
605 return fd;
606 }
607 }
608
609 /*
610 * "Release" the FileDescriptor for this impl.
611 *
612 * If the use count goes to -1 then the socket is closed.
613 */
614 void releaseFD() {
615 synchronized (fdLock) {
616 fdUseCount--;
617 if (fdUseCount == -1) {
618 if (fd != null) {
619 try {
620 socketClose();
621 } catch (IOException e) {
622 } finally {
623 fd = null;
624 }
625 }
626 }
627 }
628 }
629
630 public boolean isConnectionReset() {
631 synchronized (resetLock) {
632 return (resetState == CONNECTION_RESET);
633 }
634 }
635
636 public boolean isConnectionResetPending() {
637 synchronized (resetLock) {
638 return (resetState == CONNECTION_RESET_PENDING);
639 }
640 }
641
642 public void setConnectionReset() {
643 synchronized (resetLock) {
644 resetState = CONNECTION_RESET;
645 }
646 }
647
648 public void setConnectionResetPending() {
649 synchronized (resetLock) {
650 if (resetState == CONNECTION_NOT_RESET) {
651 resetState = CONNECTION_RESET_PENDING;
652 }
653 }
654
655 }
656
657 /*
658 * Return true if already closed or close is pending
659 */
660 public boolean isClosedOrPending() {
661 /*
662 * Lock on fdLock to ensure that we wait if a
663 * close is in progress.
664 */
665 synchronized (fdLock) {
666 if (closePending || (fd == null)) {
667 return true;
668 } else {
669 return false;
670 }
671 }
672 }
673
674 /*
675 * Return the current value of SO_TIMEOUT
676 */
677 public int getTimeout() {
678 return timeout;
679 }
680
681 /*
682 * "Pre-close" a socket by dup'ing the file descriptor - this enables
683 * the socket to be closed without releasing the file descriptor.
684 */
685 private void socketPreClose() throws IOException {
686 socketClose0(true);
687 }
688
689 /*
690 * Close the socket (and release the file descriptor).
691 */
692 protected void socketClose() throws IOException {
693 socketClose0(false);
694 }
695
696 abstract void socketCreate(boolean isServer) throws IOException;
697 abstract void socketConnect(InetAddress address, int port, int timeout)
698 throws IOException;
699 abstract void socketBind(InetAddress address, int port)
700 throws IOException;
701 abstract void socketListen(int count)
702 throws IOException;
703 abstract void socketAccept(SocketImpl s)
704 throws IOException;
705 abstract int socketAvailable()
706 throws IOException;
707 abstract void socketClose0(boolean useDeferredClose)
708 throws IOException;
709 abstract void socketShutdown(int howto)
710 throws IOException;
711 abstract void socketSetOption(int cmd, boolean on, Object value)
712 throws SocketException;
713 abstract int socketGetOption(int opt, Object iaContainerObj) throws SocketException;
714 abstract void socketSendUrgentData(int data)
715 throws IOException;
716
717 public final static int SHUT_RD = 0;
718 public final static int SHUT_WR = 1;
719 }
720
721 class InetAddressContainer {
722 InetAddress addr;
723 }