1 /*
2 * Copyright (c) 2009, 2017, 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 package com.sun.nio.sctp;
26
27 import java.net.SocketAddress;
28 import java.net.InetAddress;
29 import java.io.IOException;
30 import java.util.Set;
31 import java.nio.ByteBuffer;
32 import java.nio.channels.spi.AbstractSelectableChannel;
33 import java.nio.channels.spi.SelectorProvider;
34 import java.nio.channels.ClosedChannelException;
35 import java.nio.channels.SelectionKey;
36
37 /**
38 * A selectable channel for message-oriented connected SCTP sockets.
39 *
40 * <P> An SCTP channel can only control one SCTP association.
41 * An {@code SCTPChannel} is created by invoking one of the
42 * {@link #open open} methods of this class. A newly-created channel is open but
43 * not yet connected, that is, there is no association setup with a remote peer.
44 * An attempt to invoke an I/O operation upon an unconnected
45 * channel will cause a {@link java.nio.channels.NotYetConnectedException} to be
46 * thrown. An association can be setup by connecting the channel using one of
47 * its {@link #connect connect} methods. Once connected, the channel remains
48 * connected until it is closed. Whether or not a channel is connected may be
49 * determined by invoking {@link #getRemoteAddresses getRemoteAddresses}.
50 *
51 * <p> SCTP channels support <i>non-blocking connection:</i> A
52 * channel may be created and the process of establishing the link to
53 * the remote socket may be initiated via the {@link #connect connect} method
54 * for later completion by the {@link #finishConnect finishConnect} method.
55 * Whether or not a connection operation is in progress may be determined by
56 * invoking the {@link #isConnectionPending isConnectionPending} method.
57 *
58 * <p> Socket options are configured using the
59 * {@link #setOption(SctpSocketOption,Object) setOption} method. An SCTP
60 * channel support the following options:
61 * <blockquote>
62 * <table class="striped"><caption style="display:none">Socket options</caption>
63 * <tr>
64 * <th>Option Name</th>
65 * <th>Description</th>
66 * </tr>
67 * <tr>
68 * <td> {@link SctpStandardSocketOptions#SCTP_DISABLE_FRAGMENTS
69 * SCTP_DISABLE_FRAGMENTS} </td>
70 * <td> Enables or disables message fragmentation </td>
71 * </tr>
72 * <tr>
73 * <td> {@link SctpStandardSocketOptions#SCTP_EXPLICIT_COMPLETE
74 * SCTP_EXPLICIT_COMPLETE} </td>
75 * <td> Enables or disables explicit message completion </td>
76 * </tr>
77 * <tr>
78 * <td> {@link SctpStandardSocketOptions#SCTP_FRAGMENT_INTERLEAVE
79 * SCTP_FRAGMENT_INTERLEAVE} </td>
80 * <td> Controls how the presentation of messages occur for the message
81 * receiver </td>
82 * </tr>
83 * <tr>
84 * <td> {@link SctpStandardSocketOptions#SCTP_INIT_MAXSTREAMS
85 * SCTP_INIT_MAXSTREAMS} </td>
86 * <td> The maximum number of streams requested by the local endpoint during
87 * association initialization </td>
88 * </tr>
89 * <tr>
90 * <td> {@link SctpStandardSocketOptions#SCTP_NODELAY SCTP_NODELAY} </td>
91 * <td> Enables or disable a Nagle-like algorithm </td>
92 * </tr>
93 * <tr>
94 * <td> {@link SctpStandardSocketOptions#SCTP_PRIMARY_ADDR
95 * SCTP_PRIMARY_ADDR} </td>
96 * <td> Requests that the local SCTP stack use the given peer address as the
97 * association primary </td>
98 * </tr>
99 * <tr>
100 * <td> {@link SctpStandardSocketOptions#SCTP_SET_PEER_PRIMARY_ADDR
101 * SCTP_SET_PEER_PRIMARY_ADDR} </td>
102 * <td> Requests that the peer mark the enclosed address as the association
103 * primary </td>
104 * </tr>
105 * <tr>
106 * <td> {@link SctpStandardSocketOptions#SO_SNDBUF
107 * SO_SNDBUF} </td>
108 * <td> The size of the socket send buffer </td>
109 * </tr>
110 * <tr>
111 * <td> {@link SctpStandardSocketOptions#SO_RCVBUF
112 * SO_RCVBUF} </td>
113 * <td> The size of the socket receive buffer </td>
114 * </tr>
115 * <tr>
116 * <td> {@link SctpStandardSocketOptions#SO_LINGER
117 * SO_LINGER} </td>
118 * <td> Linger on close if data is present (when configured in blocking mode
119 * only) </td>
120 * </tr>
121 * </table>
122 * </blockquote>
123 * Additional (implementation specific) options may also be supported. The list
124 * of options supported is obtained by invoking the {@link #supportedOptions()
125 * supportedOptions} method.
126 *
127 * <p> SCTP channels are safe for use by multiple concurrent threads.
128 * They support concurrent reading and writing, though at most one thread may be
129 * reading and at most one thread may be writing at any given time. The
130 * {@link #connect connect} and {@link #finishConnect
131 * finishConnect} methods are mutually synchronized against each other, and
132 * an attempt to initiate a send or receive operation while an invocation of one
133 * of these methods is in progress will block until that invocation is complete.
134 *
135 * @since 1.7
136 */
137 public abstract class SctpChannel
138 extends AbstractSelectableChannel
139 {
140 /**
141 * Initializes a new instance of this class.
142 *
143 * @param provider
144 * The selector provider for this channel
145 */
146 protected SctpChannel(SelectorProvider provider) {
147 super(provider);
148 }
149
150 /**
151 * Opens an SCTP channel.
152 *
153 * <P> The new channel is unbound and unconnected.
154 *
155 * @return A new SCTP channel
156 *
157 * @throws UnsupportedOperationException
158 * If the SCTP protocol is not supported
159 *
160 * @throws IOException
161 * If an I/O error occurs
162 */
163 public static SctpChannel open() throws
164 IOException {
165 return new sun.nio.ch.sctp.SctpChannelImpl((SelectorProvider)null);
166 }
167
168 /**
169 * Opens an SCTP channel and connects it to a remote address.
170 *
171 * <P> This is a convenience method and is equivalent to evaluating the
172 * following expression:
173 * <blockquote><pre>
174 * open().connect(remote, maxOutStreams, maxInStreams);
175 * </pre></blockquote>
176 *
177 * @param remote
178 * The remote address to which the new channel is to be connected
179 *
180 * @param maxOutStreams
181 * The number of streams that the application wishes to be able
182 * to send to. Must be non negative and no larger than {@code 65536}.
183 * {@code 0} to use the endpoints default value.
184 *
185 * @param maxInStreams
186 * The maximum number of inbound streams the application is prepared
187 * to support. Must be non negative and no larger than {@code 65536}.
188 * {@code 0} to use the endpoints default value.
189 *
190 * @return A new SCTP channel connected to the given address
191 *
192 * @throws java.nio.channels.AsynchronousCloseException
193 * If another thread closes this channel
194 * while the connect operation is in progress
195 *
196 * @throws java.nio.channels.ClosedByInterruptException
197 * If another thread interrupts the current thread
198 * while the connect operation is in progress, thereby
199 * closing the channel and setting the current thread's
200 * interrupt status
201 *
202 * @throws java.nio.channels.UnresolvedAddressException
203 * If the given remote address is not fully resolved
204 *
205 * @throws java.nio.channels.UnsupportedAddressTypeException
206 * If the type of the given remote address is not supported
207 *
208 * @throws SecurityException
209 * If a security manager has been installed
210 * and it does not permit access to the given remote peer
211 *
212 * @throws UnsupportedOperationException
213 * If the SCTP protocol is not supported
214 *
215 * @throws IOException
216 * If some other I/O error occurs
217 */
218 public static SctpChannel open(SocketAddress remote, int maxOutStreams,
219 int maxInStreams) throws IOException {
220 SctpChannel ssc = SctpChannel.open();
221 ssc.connect(remote, maxOutStreams, maxInStreams);
222 return ssc;
223 }
224
225 /**
226 * Returns the association on this channel's socket.
227 *
228 * @return the association, or {@code null} if the channel's socket is not
229 * connected.
230 *
231 * @throws ClosedChannelException
232 * If the channel is closed
233 *
234 * @throws IOException
235 * If some other I/O error occurs
236 */
237 public abstract Association association() throws IOException;
238
239 /**
240 * Binds the channel's socket to a local address.
241 *
242 * <P> This method is used to establish a relationship between the socket
243 * and the local addresses. Once a relationship is established then
244 * the socket remains bound until the channel is closed. This relationship
245 * may not necesssarily be with the address {@code local} as it may be removed
246 * by {@link #unbindAddress unbindAddress}, but there will always be at least
247 * one local address bound to the channel's socket once an invocation of
248 * this method successfully completes.
249 *
250 * <P> Once the channel's socket has been successfully bound to a specific
251 * address, that is not automatically assigned, more addresses
252 * may be bound to it using {@link #bindAddress bindAddress}, or removed
253 * using {@link #unbindAddress unbindAddress}.
254 *
255 * @param local
256 * The local address to bind the socket, or {@code null} to
257 * bind the socket to an automatically assigned socket address
258 *
259 * @return This channel
260 *
261 * @throws java.nio.channels.AlreadyConnectedException
262 * If this channel is already connected
263 *
264 * @throws java.nio.channels.ClosedChannelException
265 * If this channel is closed
266 *
267 * @throws java.nio.channels.ConnectionPendingException
268 * If a non-blocking connection operation is already in progress on this channel
269 *
270 * @throws java.nio.channels.AlreadyBoundException
271 * If this channel is already bound
272 *
273 * @throws java.nio.channels.UnsupportedAddressTypeException
274 * If the type of the given address is not supported
275 *
276 * @throws IOException
277 * If some other I/O error occurs
278 *
279 * @throws SecurityException
280 * If a security manager has been installed and its
281 * {@link SecurityManager#checkListen checkListen} method denies
282 * the operation
283 */
284 public abstract SctpChannel bind(SocketAddress local)
285 throws IOException;
286
287 /**
288 * Adds the given address to the bound addresses for the channel's
289 * socket.
290 *
291 * <P> The given address must not be the {@link
292 * java.net.InetAddress#isAnyLocalAddress wildcard} address.
293 * The channel must be first bound using {@link #bind bind} before
294 * invoking this method, otherwise {@link
295 * java.nio.channels.NotYetBoundException} is thrown. The {@link #bind bind}
296 * method takes a {@code SocketAddress} as its argument which typically
297 * contains a port number as well as an address. Addresses subquently bound
298 * using this method are simply addresses as the SCTP port number remains
299 * the same for the lifetime of the channel.
300 *
301 * <P> Adding addresses to a connected association is optional functionality.
302 * If the endpoint supports dynamic address reconfiguration then it may
303 * send the appropriate message to the peer to change the peers address
304 * lists.
305 *
306 * @param address
307 * The address to add to the bound addresses for the socket
308 *
309 * @return This channel
310 *
311 * @throws java.nio.channels.ClosedChannelException
312 * If this channel is closed
313 *
314 * @throws java.nio.channels.ConnectionPendingException
315 * If a non-blocking connection operation is already in progress on
316 * this channel
317 *
318 * @throws java.nio.channels.NotYetBoundException
319 * If this channel is not yet bound
320 *
321 * @throws java.nio.channels.AlreadyBoundException
322 * If this channel is already bound to the given address
323 *
324 * @throws IllegalArgumentException
325 * If address is {@code null} or the {@link
326 * java.net.InetAddress#isAnyLocalAddress wildcard} address
327 *
328 * @throws IOException
329 * If some other I/O error occurs
330 */
331 public abstract SctpChannel bindAddress(InetAddress address)
332 throws IOException;
333
334 /**
335 * Removes the given address from the bound addresses for the channel's
336 * socket.
337 *
338 * <P> The given address must not be the {@link
339 * java.net.InetAddress#isAnyLocalAddress wildcard} address.
340 * The channel must be first bound using {@link #bind bind} before
341 * invoking this method, otherwise {@link java.nio.channels.NotYetBoundException}
342 * is thrown. If this method is invoked on a channel that does not have
343 * {@code address} as one of its bound addresses or that has only one
344 * local address bound to it, then this method throws
345 * {@link IllegalUnbindException}.
346 * The initial address that the channel's socket is bound to using {@link
347 * #bind bind} may be removed from the bound addresses for the channel's socket.
348 *
349 * <P> Removing addresses from a connected association is optional
350 * functionality. If the endpoint supports dynamic address reconfiguration
351 * then it may send the appropriate message to the peer to change the peers
352 * address lists.
353 *
354 * @param address
355 * The address to remove from the bound addresses for the socket
356 *
357 * @return This channel
358 *
359 * @throws java.nio.channels.ClosedChannelException
360 * If this channel is closed
361 *
362 * @throws java.nio.channels.ConnectionPendingException
363 * If a non-blocking connection operation is already in progress on
364 * this channel
365 *
366 * @throws java.nio.channels.NotYetBoundException
367 * If this channel is not yet bound
368 *
369 * @throws IllegalArgumentException
370 * If address is {@code null} or the {@link
371 * java.net.InetAddress#isAnyLocalAddress wildcard} address
372 *
373 * @throws IllegalUnbindException
374 * If {@code address} is not bound to the channel's socket. or
375 * the channel has only one address bound to it
376 *
377 * @throws IOException
378 * If some other I/O error occurs
379 */
380 public abstract SctpChannel unbindAddress(InetAddress address)
381 throws IOException;
382
383 /**
384 * Connects this channel's socket.
385 *
386 * <P> If this channel is in non-blocking mode then an invocation of this
387 * method initiates a non-blocking connection operation. If the connection
388 * is established immediately, as can happen with a local connection, then
389 * this method returns {@code true}. Otherwise this method returns
390 * {@code false} and the connection operation must later be completed by
391 * invoking the {@link #finishConnect finishConnect} method.
392 *
393 * <P> If this channel is in blocking mode then an invocation of this
394 * method will block until the connection is established or an I/O error
395 * occurs.
396 *
397 * <P> If a security manager has been installed then this method verifies
398 * that its {@link java.lang.SecurityManager#checkConnect checkConnect}
399 * method permits connecting to the address and port number of the given
400 * remote peer.
401 *
402 * <p> This method may be invoked at any time. If a {@link #send send} or
403 * {@link #receive receive} operation upon this channel is invoked while an
404 * invocation of this method is in progress then that operation will first
405 * block until this invocation is complete. If a connection attempt is
406 * initiated but fails, that is, if an invocation of this method throws a
407 * checked exception, then the channel will be closed.
408 *
409 * @param remote
410 * The remote peer to which this channel is to be connected
411 *
412 * @return {@code true} if a connection was established, {@code false} if
413 * this channel is in non-blocking mode and the connection
414 * operation is in progress
415 *
416 * @throws java.nio.channels.AlreadyConnectedException
417 * If this channel is already connected
418 *
419 * @throws java.nio.channels.ConnectionPendingException
420 * If a non-blocking connection operation is already in progress on
421 * this channel
422 *
423 * @throws java.nio.channels.ClosedChannelException
424 * If this channel is closed
425 *
426 * @throws java.nio.channels.AsynchronousCloseException
427 * If another thread closes this channel
428 * while the connect operation is in progress
429 *
430 * @throws java.nio.channels.ClosedByInterruptException
431 * If another thread interrupts the current thread
432 * while the connect operation is in progress, thereby
433 * closing the channel and setting the current thread's
434 * interrupt status
435 *
436 * @throws java.nio.channels.UnresolvedAddressException
437 * If the given remote address is not fully resolved
438 *
439 * @throws java.nio.channels.UnsupportedAddressTypeException
440 * If the type of the given remote address is not supported
441 *
442 * @throws SecurityException
443 * If a security manager has been installed
444 * and it does not permit access to the given remote peer
445 *
446 * @throws IOException
447 * If some other I/O error occurs
448 */
449 public abstract boolean connect(SocketAddress remote) throws IOException;
450
451 /**
452 * Connects this channel's socket.
453 *
454 * <P> This is a convience method and is equivalent to evaluating the
455 * following expression:
456 * <blockquote><pre>
457 * setOption(SctpStandardSocketOptions.SCTP_INIT_MAXSTREAMS, SctpStandardSocketOption.InitMaxStreams.create(maxInStreams, maxOutStreams))
458 * .connect(remote);
459 * </pre></blockquote>
460 *
461 * <P> The {@code maxOutStreams} and {@code maxInStreams} parameters
462 * represent the maximum number of streams that the application wishes to be
463 * able to send to and receive from. They are negotiated with the remote
464 * peer and may be limited by the operating system.
465 *
466 * @param remote
467 * The remote peer to which this channel is to be connected
468 *
469 * @param maxOutStreams
470 * Must be non negative and no larger than {@code 65536}.
471 * {@code 0} to use the endpoints default value.
472 *
473 * @param maxInStreams
474 * Must be non negative and no larger than {@code 65536}.
475 * {@code 0} to use the endpoints default value.
476 *
477 * @return {@code true} if a connection was established, {@code false} if
478 * this channel is in non-blocking mode and the connection operation
479 * is in progress
480 *
481 * @throws java.nio.channels.AlreadyConnectedException
482 * If this channel is already connected
483 *
484 * @throws java.nio.channels.ConnectionPendingException
485 * If a non-blocking connection operation is already in progress on
486 * this channel
487 *
488 * @throws java.nio.channels.ClosedChannelException
489 * If this channel is closed
490 *
491 * @throws java.nio.channels.AsynchronousCloseException
492 * If another thread closes this channel
493 * while the connect operation is in progress
494 *
495 * @throws java.nio.channels.ClosedByInterruptException
496 * If another thread interrupts the current thread
497 * while the connect operation is in progress, thereby
498 * closing the channel and setting the current thread's
499 * interrupt status
500 *
501 * @throws java.nio.channels.UnresolvedAddressException
502 * If the given remote address is not fully resolved
503 *
504 * @throws java.nio.channels.UnsupportedAddressTypeException
505 * If the type of the given remote address is not supported
506 *
507 * @throws SecurityException
508 * If a security manager has been installed
509 * and it does not permit access to the given remote peer
510 *
511 * @throws IOException
512 * If some other I/O error occurs
513 */
514 public abstract boolean connect(SocketAddress remote,
515 int maxOutStreams,
516 int maxInStreams)
517 throws IOException;
518
519 /**
520 * Tells whether or not a connection operation is in progress on this channel.
521 *
522 * @return {@code true} if, and only if, a connection operation has been initiated
523 * on this channel but not yet completed by invoking the
524 * {@link #finishConnect} method
525 */
526 public abstract boolean isConnectionPending();
527
528 /**
529 * Finishes the process of connecting an SCTP channel.
530 *
531 * <P> A non-blocking connection operation is initiated by placing a socket
532 * channel in non-blocking mode and then invoking one of its {@link #connect
533 * connect} methods. Once the connection is established, or the attempt has
534 * failed, the channel will become connectable and this method may
535 * be invoked to complete the connection sequence. If the connection
536 * operation failed then invoking this method will cause an appropriate
537 * {@link java.io.IOException} to be thrown.
538 *
539 * <P> If this channel is already connected then this method will not block
540 * and will immediately return {@code true}. If this channel is in
541 * non-blocking mode then this method will return {@code false} if the
542 * connection process is not yet complete. If this channel is in blocking
543 * mode then this method will block until the connection either completes
544 * or fails, and will always either return {@code true} or throw a checked
545 * exception describing the failure.
546 *
547 * <P> This method may be invoked at any time. If a {@link #send send} or {@link #receive receive}
548 * operation upon this channel is invoked while an invocation of this
549 * method is in progress then that operation will first block until this
550 * invocation is complete. If a connection attempt fails, that is, if an
551 * invocation of this method throws a checked exception, then the channel
552 * will be closed.
553 *
554 * @return {@code true} if, and only if, this channel's socket is now
555 * connected
556 *
557 * @throws java.nio.channels.NoConnectionPendingException
558 * If this channel is not connected and a connection operation
559 * has not been initiated
560 *
561 * @throws java.nio.channels.ClosedChannelException
562 * If this channel is closed
563 *
564 * @throws java.nio.channels.AsynchronousCloseException
565 * If another thread closes this channel
566 * while the connect operation is in progress
567 *
568 * @throws java.nio.channels.ClosedByInterruptException
569 * If another thread interrupts the current thread
570 * while the connect operation is in progress, thereby
571 * closing the channel and setting the current thread's
572 * interrupt status
573 *
574 * @throws IOException
575 * If some other I/O error occurs
576 */
577 public abstract boolean finishConnect() throws IOException;
578
579 /**
580 * Returns all of the socket addresses to which this channel's socket is
581 * bound.
582 *
583 * @return All the socket addresses that this channel's socket is
584 * bound to, or an empty {@code Set} if the channel's socket is not
585 * bound
586 *
587 * @throws ClosedChannelException
588 * If the channel is closed
589 *
590 * @throws IOException
591 * If an I/O error occurs
592 */
593 public abstract Set<SocketAddress> getAllLocalAddresses()
594 throws IOException;
595
596 /**
597 * Returns all of the remote addresses to which this channel's socket
598 * is connected.
599 *
600 * <P> If the channel is connected to a remote peer that is bound to
601 * multiple addresses then it is these addresses that the channel's socket
602 * is connected.
603 *
604 * @return All of the remote addresses to which this channel's socket
605 * is connected, or an empty {@code Set} if the channel's socket is
606 * not connected
607 *
608 * @throws ClosedChannelException
609 * If the channel is closed
610 *
611 * @throws IOException
612 * If an I/O error occurs
613 */
614 public abstract Set<SocketAddress> getRemoteAddresses()
615 throws IOException;
616
617 /**
618 * Shutdown a connection without closing the channel.
619 *
620 * <P> Sends a shutdown command to the remote peer, effectively preventing
621 * any new data from being written to the socket by either peer. Further
622 * sends will throw {@link java.nio.channels.ClosedChannelException}. The
623 * channel remains open to allow the for any data (and notifications) to be
624 * received that may have been sent by the peer before it received the
625 * shutdown command. If the channel is already shutdown then invoking this
626 * method has no effect.
627 *
628 * @return This channel
629 *
630 * @throws java.nio.channels.NotYetConnectedException
631 * If this channel is not yet connected
632 *
633 * @throws java.nio.channels.ClosedChannelException
634 * If this channel is closed
635 *
636 * @throws IOException
637 * If some other I/O error occurs
638 */
639 public abstract SctpChannel shutdown() throws IOException;
640
641 /**
642 * Returns the value of a socket option.
643 *
644 * @param <T>
645 * The type of the socket option value
646 *
647 * @param name
648 * The socket option
649 *
650 * @return The value of the socket option. A value of {@code null} may be
651 * a valid value for some socket options.
652 *
653 * @throws UnsupportedOperationException
654 * If the socket option is not supported by this channel
655 *
656 * @throws ClosedChannelException
657 * If this channel is closed
658 *
659 * @throws IOException
660 * If an I/O error occurs
661 *
662 * @see SctpStandardSocketOptions
663 */
664 public abstract <T> T getOption(SctpSocketOption<T> name)
665 throws IOException;
666
667 /**
668 * Sets the value of a socket option.
669 *
670 * @param <T>
671 * The type of the socket option value
672 *
673 * @param name
674 * The socket option
675 *
676 * @param value
677 * The value of the socket option. A value of {@code null} may be
678 * a valid value for some socket options.
679 *
680 * @return This channel
681 *
682 * @throws UnsupportedOperationException
683 * If the socket option is not supported by this channel
684 *
685 * @throws IllegalArgumentException
686 * If the value is not a valid value for this socket option
687 *
688 * @throws ClosedChannelException
689 * If this channel is closed
690 *
691 * @throws IOException
692 * If an I/O error occurs
693 *
694 * @see SctpStandardSocketOptions
695 */
696 public abstract <T> SctpChannel setOption(SctpSocketOption<T> name, T value)
697 throws IOException;
698
699 /**
700 * Returns a set of the socket options supported by this channel.
701 *
702 * <P> This method will continue to return the set of options even after the
703 * channel has been closed.
704 *
705 * @return A set of the socket options supported by this channel
706 */
707 public abstract Set<SctpSocketOption<?>> supportedOptions();
708
709 /**
710 * Returns an operation set identifying this channel's supported operations.
711 *
712 * <P> SCTP channels support connecting, reading, and writing, so this
713 * method returns {@code (}{@link SelectionKey#OP_CONNECT}
714 * {@code |} {@link SelectionKey#OP_READ} {@code |} {@link
715 * SelectionKey#OP_WRITE}{@code )}.
716 *
717 * @return The valid-operation set
718 */
719 @Override
720 public final int validOps() {
721 return (SelectionKey.OP_READ |
722 SelectionKey.OP_WRITE |
723 SelectionKey.OP_CONNECT);
724 }
725
726 /**
727 * Receives a message into the given buffer and/or handles a notification.
728 *
729 * <P> If a message or notification is immediately available, or if this
730 * channel is in blocking mode and one eventually becomes available, then
731 * the message or notification is returned or handled, respectively. If this
732 * channel is in non-blocking mode and a message or notification is not
733 * immediately available then this method immediately returns {@code null}.
734 *
735 * <P> If this method receives a message it is copied into the given byte
736 * buffer. The message is transferred into the given byte buffer starting at
737 * its current position and the buffers position is incremented by the
738 * number of bytes read. If there are fewer bytes remaining in the buffer
739 * than are required to hold the message, or the underlying input buffer
740 * does not contain the complete message, then an invocation of {@link
741 * MessageInfo#isComplete isComplete} on the returned {@code
742 * MessageInfo} will return {@code false}, and more invocations of this
743 * method will be necessary to completely consume the messgae. Only
744 * one message at a time will be partially delivered in any stream. The
745 * socket option {@link SctpStandardSocketOptions#SCTP_FRAGMENT_INTERLEAVE
746 * SCTP_FRAGMENT_INTERLEAVE} controls various aspects of what interlacing of
747 * messages occurs.
748 *
749 * <P> If this method receives a notification then the appropriate method of
750 * the given handler, if there is one, is invoked. If the handler returns
751 * {@link HandlerResult#CONTINUE CONTINUE} then this method will try to
752 * receive another message/notification, otherwise, if {@link
753 * HandlerResult#RETURN RETURN} is returned this method will return {@code
754 * null}. If an uncaught exception is thrown by the handler it will be
755 * propagated up the stack through this method.
756 *
757 * <P> This method may be invoked at any time. If another thread has
758 * already initiated a receive operation upon this channel, then an
759 * invocation of this method will block until the first operation is
760 * complete. The given handler is invoked without holding any locks used
761 * to enforce the above synchronization policy, that way handlers
762 * will not stall other threads from receiving. A handler should not invoke
763 * the {@code receive} method of this channel, if it does an
764 * {@link IllegalReceiveException} will be thrown.
765 *
766 * @param <T>
767 * The type of the attachment
768 *
769 * @param dst
770 * The buffer into which message bytes are to be transferred
771 *
772 * @param attachment
773 * The object to attach to the receive operation; can be
774 * {@code null}
775 *
776 * @param handler
777 * A handler to handle notifications from the SCTP stack, or {@code
778 * null} to ignore any notifications.
779 *
780 * @return The {@code MessageInfo}, {@code null} if this channel is in
781 * non-blocking mode and no messages are immediately available or
782 * the notification handler returns {@link HandlerResult#RETURN
783 * RETURN} after handling a notification
784 *
785 * @throws java.nio.channels.ClosedChannelException
786 * If this channel is closed
787 *
788 * @throws java.nio.channels.AsynchronousCloseException
789 * If another thread closes this channel
790 * while the read operation is in progress
791 *
792 * @throws java.nio.channels.ClosedByInterruptException
793 * If another thread interrupts the current thread
794 * while the read operation is in progress, thereby
795 * closing the channel and setting the current thread's
796 * interrupt status
797 *
798 * @throws java.nio.channels.NotYetConnectedException
799 * If this channel is not yet connected
800 *
801 * @throws IllegalReceiveException
802 * If the given handler invokes the {@code receive} method of this
803 * channel
804 *
805 * @throws IOException
806 * If some other I/O error occurs
807 */
808 public abstract <T> MessageInfo receive(ByteBuffer dst,
809 T attachment,
810 NotificationHandler<T> handler)
811 throws IOException;
812
813 /**
814 * Sends a message via this channel.
815 *
816 * <P> If this channel is in non-blocking mode and there is sufficient room
817 * in the underlying output buffer, or if this channel is in blocking mode
818 * and sufficient room becomes available, then the remaining bytes in the
819 * given byte buffer are transmitted as a single message. Sending a message
820 * is atomic unless explicit message completion {@link
821 * SctpStandardSocketOptions#SCTP_EXPLICIT_COMPLETE SCTP_EXPLICIT_COMPLETE}
822 * socket option is enabled on this channel's socket.
823 *
824 * <P> The message is transferred from the byte buffer as if by a regular
825 * {@link java.nio.channels.WritableByteChannel#write(java.nio.ByteBuffer)
826 * write} operation.
827 *
828 * <P> The bytes will be written to the stream number that is specified by
829 * {@link MessageInfo#streamNumber streamNumber} in the given {@code
830 * messageInfo}.
831 *
832 * <P> This method may be invoked at any time. If another thread has already
833 * initiated a send operation upon this channel, then an invocation of
834 * this method will block until the first operation is complete.
835 *
836 * @param src
837 * The buffer containing the message to be sent
838 *
839 * @param messageInfo
840 * Ancillary data about the message to be sent
841 *
842 * @return The number of bytes sent, which will be either the number of
843 * bytes that were remaining in the messages buffer when this method
844 * was invoked or, if this channel is non-blocking, may be zero if
845 * there was insufficient room for the message in the underlying
846 * output buffer
847 *
848 * @throws InvalidStreamException
849 * If {@code streamNumner} is negative or greater than or equal to
850 * the maximum number of outgoing streams
851 *
852 * @throws java.nio.channels.ClosedChannelException
853 * If this channel is closed
854 *
855 * @throws java.nio.channels.AsynchronousCloseException
856 * If another thread closes this channel
857 * while the read operation is in progress
858 *
859 * @throws java.nio.channels.ClosedByInterruptException
860 * If another thread interrupts the current thread
861 * while the read operation is in progress, thereby
862 * closing the channel and setting the current thread's
863 * interrupt status
864 *
865 * @throws java.nio.channels.NotYetConnectedException
866 * If this channel is not yet connected
867 *
868 * @throws IOException
869 * If some other I/O error occurs
870 */
871 public abstract int send(ByteBuffer src, MessageInfo messageInfo)
872 throws IOException;
873 }