xref: /openbmc/linux/net/sctp/ulpevent.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
1 /* SCTP kernel reference Implementation
2  * (C) Copyright IBM Corp. 2001, 2004
3  * Copyright (c) 1999-2000 Cisco, Inc.
4  * Copyright (c) 1999-2001 Motorola, Inc.
5  * Copyright (c) 2001 Intel Corp.
6  * Copyright (c) 2001 Nokia, Inc.
7  * Copyright (c) 2001 La Monte H.P. Yarroll
8  *
9  * These functions manipulate an sctp event.   The struct ulpevent is used
10  * to carry notifications and data to the ULP (sockets).
11  * The SCTP reference implementation is free software;
12  * you can redistribute it and/or modify it under the terms of
13  * the GNU General Public License as published by
14  * the Free Software Foundation; either version 2, or (at your option)
15  * any later version.
16  *
17  * The SCTP reference implementation is distributed in the hope that it
18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19  *                 ************************
20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21  * See the GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with GNU CC; see the file COPYING.  If not, write to
25  * the Free Software Foundation, 59 Temple Place - Suite 330,
26  * Boston, MA 02111-1307, USA.
27  *
28  * Please send any bug reports or fixes you make to the
29  * email address(es):
30  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
31  *
32  * Or submit a bug report through the following website:
33  *    http://www.sf.net/projects/lksctp
34  *
35  * Written or modified by:
36  *    Jon Grimm             <jgrimm@us.ibm.com>
37  *    La Monte H.P. Yarroll <piggy@acm.org>
38  *    Ardelle Fan	    <ardelle.fan@intel.com>
39  *    Sridhar Samudrala     <sri@us.ibm.com>
40  *
41  * Any bugs reported given to us we will try to fix... any fixes shared will
42  * be incorporated into the next SCTP release.
43  */
44 
45 #include <linux/types.h>
46 #include <linux/skbuff.h>
47 #include <net/sctp/structs.h>
48 #include <net/sctp/sctp.h>
49 #include <net/sctp/sm.h>
50 
51 static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
52 				       struct sctp_association *asoc);
53 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event);
54 static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event);
55 
56 
57 /* Initialize an ULP event from an given skb.  */
58 SCTP_STATIC void sctp_ulpevent_init(struct sctp_ulpevent *event,
59 				    int msg_flags,
60 				    unsigned int len)
61 {
62 	memset(event, 0, sizeof(struct sctp_ulpevent));
63 	event->msg_flags = msg_flags;
64 	event->rmem_len = len;
65 }
66 
67 /* Create a new sctp_ulpevent.  */
68 SCTP_STATIC struct sctp_ulpevent *sctp_ulpevent_new(int size, int msg_flags,
69 						    gfp_t gfp)
70 {
71 	struct sctp_ulpevent *event;
72 	struct sk_buff *skb;
73 
74 	skb = alloc_skb(size, gfp);
75 	if (!skb)
76 		goto fail;
77 
78 	event = sctp_skb2event(skb);
79 	sctp_ulpevent_init(event, msg_flags, skb->truesize);
80 
81 	return event;
82 
83 fail:
84 	return NULL;
85 }
86 
87 /* Is this a MSG_NOTIFICATION?  */
88 int sctp_ulpevent_is_notification(const struct sctp_ulpevent *event)
89 {
90 	return MSG_NOTIFICATION == (event->msg_flags & MSG_NOTIFICATION);
91 }
92 
93 /* Hold the association in case the msg_name needs read out of
94  * the association.
95  */
96 static inline void sctp_ulpevent_set_owner(struct sctp_ulpevent *event,
97 					   const struct sctp_association *asoc)
98 {
99 	struct sk_buff *skb;
100 
101 	/* Cast away the const, as we are just wanting to
102 	 * bump the reference count.
103 	 */
104 	sctp_association_hold((struct sctp_association *)asoc);
105 	skb = sctp_event2skb(event);
106 	event->asoc = (struct sctp_association *)asoc;
107 	atomic_add(event->rmem_len, &event->asoc->rmem_alloc);
108 	sctp_skb_set_owner_r(skb, asoc->base.sk);
109 }
110 
111 /* A simple destructor to give up the reference to the association. */
112 static inline void sctp_ulpevent_release_owner(struct sctp_ulpevent *event)
113 {
114 	struct sctp_association *asoc = event->asoc;
115 
116 	atomic_sub(event->rmem_len, &asoc->rmem_alloc);
117 	sctp_association_put(asoc);
118 }
119 
120 /* Create and initialize an SCTP_ASSOC_CHANGE event.
121  *
122  * 5.3.1.1 SCTP_ASSOC_CHANGE
123  *
124  * Communication notifications inform the ULP that an SCTP association
125  * has either begun or ended. The identifier for a new association is
126  * provided by this notification.
127  *
128  * Note: There is no field checking here.  If a field is unused it will be
129  * zero'd out.
130  */
131 struct sctp_ulpevent  *sctp_ulpevent_make_assoc_change(
132 	const struct sctp_association *asoc,
133 	__u16 flags, __u16 state, __u16 error, __u16 outbound,
134 	__u16 inbound, struct sctp_chunk *chunk, gfp_t gfp)
135 {
136 	struct sctp_ulpevent *event;
137 	struct sctp_assoc_change *sac;
138 	struct sk_buff *skb;
139 
140 	/* If the lower layer passed in the chunk, it will be
141 	 * an ABORT, so we need to include it in the sac_info.
142 	 */
143 	if (chunk) {
144 		/* Copy the chunk data to a new skb and reserve enough
145 		 * head room to use as notification.
146 		 */
147 		skb = skb_copy_expand(chunk->skb,
148 				      sizeof(struct sctp_assoc_change), 0, gfp);
149 
150 		if (!skb)
151 			goto fail;
152 
153 		/* Embed the event fields inside the cloned skb.  */
154 		event = sctp_skb2event(skb);
155 		sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
156 
157 		/* Include the notification structure */
158 		sac = (struct sctp_assoc_change *)
159 			skb_push(skb, sizeof(struct sctp_assoc_change));
160 
161 		/* Trim the buffer to the right length.  */
162 		skb_trim(skb, sizeof(struct sctp_assoc_change) +
163 			 ntohs(chunk->chunk_hdr->length) -
164 			 sizeof(sctp_chunkhdr_t));
165 	} else {
166 		event = sctp_ulpevent_new(sizeof(struct sctp_assoc_change),
167 				  MSG_NOTIFICATION, gfp);
168 		if (!event)
169 			goto fail;
170 
171 		skb = sctp_event2skb(event);
172 		sac = (struct sctp_assoc_change *) skb_put(skb,
173 					sizeof(struct sctp_assoc_change));
174 	}
175 
176 	/* Socket Extensions for SCTP
177 	 * 5.3.1.1 SCTP_ASSOC_CHANGE
178 	 *
179 	 * sac_type:
180 	 * It should be SCTP_ASSOC_CHANGE.
181 	 */
182 	sac->sac_type = SCTP_ASSOC_CHANGE;
183 
184 	/* Socket Extensions for SCTP
185 	 * 5.3.1.1 SCTP_ASSOC_CHANGE
186 	 *
187 	 * sac_state: 32 bits (signed integer)
188 	 * This field holds one of a number of values that communicate the
189 	 * event that happened to the association.
190 	 */
191 	sac->sac_state = state;
192 
193 	/* Socket Extensions for SCTP
194 	 * 5.3.1.1 SCTP_ASSOC_CHANGE
195 	 *
196 	 * sac_flags: 16 bits (unsigned integer)
197 	 * Currently unused.
198 	 */
199 	sac->sac_flags = 0;
200 
201 	/* Socket Extensions for SCTP
202 	 * 5.3.1.1 SCTP_ASSOC_CHANGE
203 	 *
204 	 * sac_length: sizeof (__u32)
205 	 * This field is the total length of the notification data, including
206 	 * the notification header.
207 	 */
208 	sac->sac_length = sizeof(struct sctp_assoc_change);
209 
210 	/* Socket Extensions for SCTP
211 	 * 5.3.1.1 SCTP_ASSOC_CHANGE
212 	 *
213 	 * sac_error:  32 bits (signed integer)
214 	 *
215 	 * If the state was reached due to a error condition (e.g.
216 	 * COMMUNICATION_LOST) any relevant error information is available in
217 	 * this field. This corresponds to the protocol error codes defined in
218 	 * [SCTP].
219 	 */
220 	sac->sac_error = error;
221 
222 	/* Socket Extensions for SCTP
223 	 * 5.3.1.1 SCTP_ASSOC_CHANGE
224 	 *
225 	 * sac_outbound_streams:  16 bits (unsigned integer)
226 	 * sac_inbound_streams:  16 bits (unsigned integer)
227 	 *
228 	 * The maximum number of streams allowed in each direction are
229 	 * available in sac_outbound_streams and sac_inbound streams.
230 	 */
231 	sac->sac_outbound_streams = outbound;
232 	sac->sac_inbound_streams = inbound;
233 
234 	/* Socket Extensions for SCTP
235 	 * 5.3.1.1 SCTP_ASSOC_CHANGE
236 	 *
237 	 * sac_assoc_id: sizeof (sctp_assoc_t)
238 	 *
239 	 * The association id field, holds the identifier for the association.
240 	 * All notifications for a given association have the same association
241 	 * identifier.  For TCP style socket, this field is ignored.
242 	 */
243 	sctp_ulpevent_set_owner(event, asoc);
244 	sac->sac_assoc_id = sctp_assoc2id(asoc);
245 
246 	return event;
247 
248 fail:
249 	return NULL;
250 }
251 
252 /* Create and initialize an SCTP_PEER_ADDR_CHANGE event.
253  *
254  * Socket Extensions for SCTP - draft-01
255  * 5.3.1.2 SCTP_PEER_ADDR_CHANGE
256  *
257  * When a destination address on a multi-homed peer encounters a change
258  * an interface details event is sent.
259  */
260 struct sctp_ulpevent *sctp_ulpevent_make_peer_addr_change(
261 	const struct sctp_association *asoc,
262 	const struct sockaddr_storage *aaddr,
263 	int flags, int state, int error, gfp_t gfp)
264 {
265 	struct sctp_ulpevent *event;
266 	struct sctp_paddr_change  *spc;
267 	struct sk_buff *skb;
268 
269 	event = sctp_ulpevent_new(sizeof(struct sctp_paddr_change),
270 				  MSG_NOTIFICATION, gfp);
271 	if (!event)
272 		goto fail;
273 
274 	skb = sctp_event2skb(event);
275 	spc = (struct sctp_paddr_change *)
276 		skb_put(skb, sizeof(struct sctp_paddr_change));
277 
278 	/* Sockets API Extensions for SCTP
279 	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
280 	 *
281 	 * spc_type:
282 	 *
283 	 *    It should be SCTP_PEER_ADDR_CHANGE.
284 	 */
285 	spc->spc_type = SCTP_PEER_ADDR_CHANGE;
286 
287 	/* Sockets API Extensions for SCTP
288 	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
289 	 *
290 	 * spc_length: sizeof (__u32)
291 	 *
292 	 * This field is the total length of the notification data, including
293 	 * the notification header.
294 	 */
295 	spc->spc_length = sizeof(struct sctp_paddr_change);
296 
297 	/* Sockets API Extensions for SCTP
298 	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
299 	 *
300 	 * spc_flags: 16 bits (unsigned integer)
301 	 * Currently unused.
302 	 */
303 	spc->spc_flags = 0;
304 
305 	/* Sockets API Extensions for SCTP
306 	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
307 	 *
308 	 * spc_state:  32 bits (signed integer)
309 	 *
310 	 * This field holds one of a number of values that communicate the
311 	 * event that happened to the address.
312 	 */
313 	spc->spc_state = state;
314 
315 	/* Sockets API Extensions for SCTP
316 	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
317 	 *
318 	 * spc_error:  32 bits (signed integer)
319 	 *
320 	 * If the state was reached due to any error condition (e.g.
321 	 * ADDRESS_UNREACHABLE) any relevant error information is available in
322 	 * this field.
323 	 */
324 	spc->spc_error = error;
325 
326 	/* Socket Extensions for SCTP
327 	 * 5.3.1.1 SCTP_ASSOC_CHANGE
328 	 *
329 	 * spc_assoc_id: sizeof (sctp_assoc_t)
330 	 *
331 	 * The association id field, holds the identifier for the association.
332 	 * All notifications for a given association have the same association
333 	 * identifier.  For TCP style socket, this field is ignored.
334 	 */
335 	sctp_ulpevent_set_owner(event, asoc);
336 	spc->spc_assoc_id = sctp_assoc2id(asoc);
337 
338 	/* Sockets API Extensions for SCTP
339 	 * Section 5.3.1.2 SCTP_PEER_ADDR_CHANGE
340 	 *
341 	 * spc_aaddr: sizeof (struct sockaddr_storage)
342 	 *
343 	 * The affected address field, holds the remote peer's address that is
344 	 * encountering the change of state.
345 	 */
346 	memcpy(&spc->spc_aaddr, aaddr, sizeof(struct sockaddr_storage));
347 
348 	/* Map ipv4 address into v4-mapped-on-v6 address.  */
349 	sctp_get_pf_specific(asoc->base.sk->sk_family)->addr_v4map(
350 					sctp_sk(asoc->base.sk),
351 					(union sctp_addr *)&spc->spc_aaddr);
352 
353 	return event;
354 
355 fail:
356 	return NULL;
357 }
358 
359 /* Create and initialize an SCTP_REMOTE_ERROR notification.
360  *
361  * Note: This assumes that the chunk->skb->data already points to the
362  * operation error payload.
363  *
364  * Socket Extensions for SCTP - draft-01
365  * 5.3.1.3 SCTP_REMOTE_ERROR
366  *
367  * A remote peer may send an Operational Error message to its peer.
368  * This message indicates a variety of error conditions on an
369  * association. The entire error TLV as it appears on the wire is
370  * included in a SCTP_REMOTE_ERROR event.  Please refer to the SCTP
371  * specification [SCTP] and any extensions for a list of possible
372  * error formats.
373  */
374 struct sctp_ulpevent *sctp_ulpevent_make_remote_error(
375 	const struct sctp_association *asoc, struct sctp_chunk *chunk,
376 	__u16 flags, gfp_t gfp)
377 {
378 	struct sctp_ulpevent *event;
379 	struct sctp_remote_error *sre;
380 	struct sk_buff *skb;
381 	sctp_errhdr_t *ch;
382 	__be16 cause;
383 	int elen;
384 
385 	ch = (sctp_errhdr_t *)(chunk->skb->data);
386 	cause = ch->cause;
387 	elen = WORD_ROUND(ntohs(ch->length)) - sizeof(sctp_errhdr_t);
388 
389 	/* Pull off the ERROR header.  */
390 	skb_pull(chunk->skb, sizeof(sctp_errhdr_t));
391 
392 	/* Copy the skb to a new skb with room for us to prepend
393 	 * notification with.
394 	 */
395 	skb = skb_copy_expand(chunk->skb, sizeof(struct sctp_remote_error),
396 			      0, gfp);
397 
398 	/* Pull off the rest of the cause TLV from the chunk.  */
399 	skb_pull(chunk->skb, elen);
400 	if (!skb)
401 		goto fail;
402 
403 	/* Embed the event fields inside the cloned skb.  */
404 	event = sctp_skb2event(skb);
405 	sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
406 
407 	sre = (struct sctp_remote_error *)
408 		skb_push(skb, sizeof(struct sctp_remote_error));
409 
410 	/* Trim the buffer to the right length.  */
411 	skb_trim(skb, sizeof(struct sctp_remote_error) + elen);
412 
413 	/* Socket Extensions for SCTP
414 	 * 5.3.1.3 SCTP_REMOTE_ERROR
415 	 *
416 	 * sre_type:
417 	 *   It should be SCTP_REMOTE_ERROR.
418 	 */
419 	sre->sre_type = SCTP_REMOTE_ERROR;
420 
421 	/*
422 	 * Socket Extensions for SCTP
423 	 * 5.3.1.3 SCTP_REMOTE_ERROR
424 	 *
425 	 * sre_flags: 16 bits (unsigned integer)
426 	 *   Currently unused.
427 	 */
428 	sre->sre_flags = 0;
429 
430 	/* Socket Extensions for SCTP
431 	 * 5.3.1.3 SCTP_REMOTE_ERROR
432 	 *
433 	 * sre_length: sizeof (__u32)
434 	 *
435 	 * This field is the total length of the notification data,
436 	 * including the notification header.
437 	 */
438 	sre->sre_length = skb->len;
439 
440 	/* Socket Extensions for SCTP
441 	 * 5.3.1.3 SCTP_REMOTE_ERROR
442 	 *
443 	 * sre_error: 16 bits (unsigned integer)
444 	 * This value represents one of the Operational Error causes defined in
445 	 * the SCTP specification, in network byte order.
446 	 */
447 	sre->sre_error = cause;
448 
449 	/* Socket Extensions for SCTP
450 	 * 5.3.1.3 SCTP_REMOTE_ERROR
451 	 *
452 	 * sre_assoc_id: sizeof (sctp_assoc_t)
453 	 *
454 	 * The association id field, holds the identifier for the association.
455 	 * All notifications for a given association have the same association
456 	 * identifier.  For TCP style socket, this field is ignored.
457 	 */
458 	sctp_ulpevent_set_owner(event, asoc);
459 	sre->sre_assoc_id = sctp_assoc2id(asoc);
460 
461 	return event;
462 
463 fail:
464 	return NULL;
465 }
466 
467 /* Create and initialize a SCTP_SEND_FAILED notification.
468  *
469  * Socket Extensions for SCTP - draft-01
470  * 5.3.1.4 SCTP_SEND_FAILED
471  */
472 struct sctp_ulpevent *sctp_ulpevent_make_send_failed(
473 	const struct sctp_association *asoc, struct sctp_chunk *chunk,
474 	__u16 flags, __u32 error, gfp_t gfp)
475 {
476 	struct sctp_ulpevent *event;
477 	struct sctp_send_failed *ssf;
478 	struct sk_buff *skb;
479 
480 	/* Pull off any padding. */
481 	int len = ntohs(chunk->chunk_hdr->length);
482 
483 	/* Make skb with more room so we can prepend notification.  */
484 	skb = skb_copy_expand(chunk->skb,
485 			      sizeof(struct sctp_send_failed), /* headroom */
486 			      0,                               /* tailroom */
487 			      gfp);
488 	if (!skb)
489 		goto fail;
490 
491 	/* Pull off the common chunk header and DATA header.  */
492 	skb_pull(skb, sizeof(struct sctp_data_chunk));
493 	len -= sizeof(struct sctp_data_chunk);
494 
495 	/* Embed the event fields inside the cloned skb.  */
496 	event = sctp_skb2event(skb);
497 	sctp_ulpevent_init(event, MSG_NOTIFICATION, skb->truesize);
498 
499 	ssf = (struct sctp_send_failed *)
500 		skb_push(skb, sizeof(struct sctp_send_failed));
501 
502 	/* Socket Extensions for SCTP
503 	 * 5.3.1.4 SCTP_SEND_FAILED
504 	 *
505 	 * ssf_type:
506 	 * It should be SCTP_SEND_FAILED.
507 	 */
508 	ssf->ssf_type = SCTP_SEND_FAILED;
509 
510 	/* Socket Extensions for SCTP
511 	 * 5.3.1.4 SCTP_SEND_FAILED
512 	 *
513 	 * ssf_flags: 16 bits (unsigned integer)
514 	 * The flag value will take one of the following values
515 	 *
516 	 * SCTP_DATA_UNSENT - Indicates that the data was never put on
517 	 *                    the wire.
518 	 *
519 	 * SCTP_DATA_SENT   - Indicates that the data was put on the wire.
520 	 *                    Note that this does not necessarily mean that the
521 	 *                    data was (or was not) successfully delivered.
522 	 */
523 	ssf->ssf_flags = flags;
524 
525 	/* Socket Extensions for SCTP
526 	 * 5.3.1.4 SCTP_SEND_FAILED
527 	 *
528 	 * ssf_length: sizeof (__u32)
529 	 * This field is the total length of the notification data, including
530 	 * the notification header.
531 	 */
532 	ssf->ssf_length = sizeof(struct sctp_send_failed) + len;
533 	skb_trim(skb, ssf->ssf_length);
534 
535 	/* Socket Extensions for SCTP
536 	 * 5.3.1.4 SCTP_SEND_FAILED
537 	 *
538 	 * ssf_error: 16 bits (unsigned integer)
539 	 * This value represents the reason why the send failed, and if set,
540 	 * will be a SCTP protocol error code as defined in [SCTP] section
541 	 * 3.3.10.
542 	 */
543 	ssf->ssf_error = error;
544 
545 	/* Socket Extensions for SCTP
546 	 * 5.3.1.4 SCTP_SEND_FAILED
547 	 *
548 	 * ssf_info: sizeof (struct sctp_sndrcvinfo)
549 	 * The original send information associated with the undelivered
550 	 * message.
551 	 */
552 	memcpy(&ssf->ssf_info, &chunk->sinfo, sizeof(struct sctp_sndrcvinfo));
553 
554 	/* Per TSVWG discussion with Randy. Allow the application to
555 	 * ressemble a fragmented message.
556 	 */
557 	ssf->ssf_info.sinfo_flags = chunk->chunk_hdr->flags;
558 
559 	/* Socket Extensions for SCTP
560 	 * 5.3.1.4 SCTP_SEND_FAILED
561 	 *
562 	 * ssf_assoc_id: sizeof (sctp_assoc_t)
563 	 * The association id field, sf_assoc_id, holds the identifier for the
564 	 * association.  All notifications for a given association have the
565 	 * same association identifier.  For TCP style socket, this field is
566 	 * ignored.
567 	 */
568 	sctp_ulpevent_set_owner(event, asoc);
569 	ssf->ssf_assoc_id = sctp_assoc2id(asoc);
570 	return event;
571 
572 fail:
573 	return NULL;
574 }
575 
576 /* Create and initialize a SCTP_SHUTDOWN_EVENT notification.
577  *
578  * Socket Extensions for SCTP - draft-01
579  * 5.3.1.5 SCTP_SHUTDOWN_EVENT
580  */
581 struct sctp_ulpevent *sctp_ulpevent_make_shutdown_event(
582 	const struct sctp_association *asoc,
583 	__u16 flags, gfp_t gfp)
584 {
585 	struct sctp_ulpevent *event;
586 	struct sctp_shutdown_event *sse;
587 	struct sk_buff *skb;
588 
589 	event = sctp_ulpevent_new(sizeof(struct sctp_shutdown_event),
590 				  MSG_NOTIFICATION, gfp);
591 	if (!event)
592 		goto fail;
593 
594 	skb = sctp_event2skb(event);
595 	sse = (struct sctp_shutdown_event *)
596 		skb_put(skb, sizeof(struct sctp_shutdown_event));
597 
598 	/* Socket Extensions for SCTP
599 	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
600 	 *
601 	 * sse_type
602 	 * It should be SCTP_SHUTDOWN_EVENT
603 	 */
604 	sse->sse_type = SCTP_SHUTDOWN_EVENT;
605 
606 	/* Socket Extensions for SCTP
607 	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
608 	 *
609 	 * sse_flags: 16 bits (unsigned integer)
610 	 * Currently unused.
611 	 */
612 	sse->sse_flags = 0;
613 
614 	/* Socket Extensions for SCTP
615 	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
616 	 *
617 	 * sse_length: sizeof (__u32)
618 	 * This field is the total length of the notification data, including
619 	 * the notification header.
620 	 */
621 	sse->sse_length = sizeof(struct sctp_shutdown_event);
622 
623 	/* Socket Extensions for SCTP
624 	 * 5.3.1.5 SCTP_SHUTDOWN_EVENT
625 	 *
626 	 * sse_assoc_id: sizeof (sctp_assoc_t)
627 	 * The association id field, holds the identifier for the association.
628 	 * All notifications for a given association have the same association
629 	 * identifier.  For TCP style socket, this field is ignored.
630 	 */
631 	sctp_ulpevent_set_owner(event, asoc);
632 	sse->sse_assoc_id = sctp_assoc2id(asoc);
633 
634 	return event;
635 
636 fail:
637 	return NULL;
638 }
639 
640 /* Create and initialize a SCTP_ADAPTATION_INDICATION notification.
641  *
642  * Socket Extensions for SCTP
643  * 5.3.1.6 SCTP_ADAPTATION_INDICATION
644  */
645 struct sctp_ulpevent *sctp_ulpevent_make_adaptation_indication(
646 	const struct sctp_association *asoc, gfp_t gfp)
647 {
648 	struct sctp_ulpevent *event;
649 	struct sctp_adaptation_event *sai;
650 	struct sk_buff *skb;
651 
652 	event = sctp_ulpevent_new(sizeof(struct sctp_adaptation_event),
653 				  MSG_NOTIFICATION, gfp);
654 	if (!event)
655 		goto fail;
656 
657 	skb = sctp_event2skb(event);
658 	sai = (struct sctp_adaptation_event *)
659 		skb_put(skb, sizeof(struct sctp_adaptation_event));
660 
661 	sai->sai_type = SCTP_ADAPTATION_INDICATION;
662 	sai->sai_flags = 0;
663 	sai->sai_length = sizeof(struct sctp_adaptation_event);
664 	sai->sai_adaptation_ind = asoc->peer.adaptation_ind;
665 	sctp_ulpevent_set_owner(event, asoc);
666 	sai->sai_assoc_id = sctp_assoc2id(asoc);
667 
668 	return event;
669 
670 fail:
671 	return NULL;
672 }
673 
674 /* A message has been received.  Package this message as a notification
675  * to pass it to the upper layers.  Go ahead and calculate the sndrcvinfo
676  * even if filtered out later.
677  *
678  * Socket Extensions for SCTP
679  * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
680  */
681 struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
682 						struct sctp_chunk *chunk,
683 						gfp_t gfp)
684 {
685 	struct sctp_ulpevent *event = NULL;
686 	struct sk_buff *skb;
687 	size_t padding, len;
688 
689 	/* Clone the original skb, sharing the data.  */
690 	skb = skb_clone(chunk->skb, gfp);
691 	if (!skb)
692 		goto fail;
693 
694 	/* First calculate the padding, so we don't inadvertently
695 	 * pass up the wrong length to the user.
696 	 *
697 	 * RFC 2960 - Section 3.2  Chunk Field Descriptions
698 	 *
699 	 * The total length of a chunk(including Type, Length and Value fields)
700 	 * MUST be a multiple of 4 bytes.  If the length of the chunk is not a
701 	 * multiple of 4 bytes, the sender MUST pad the chunk with all zero
702 	 * bytes and this padding is not included in the chunk length field.
703 	 * The sender should never pad with more than 3 bytes.  The receiver
704 	 * MUST ignore the padding bytes.
705 	 */
706 	len = ntohs(chunk->chunk_hdr->length);
707 	padding = WORD_ROUND(len) - len;
708 
709 	/* Fixup cloned skb with just this chunks data.  */
710 	skb_trim(skb, chunk->chunk_end - padding - skb->data);
711 
712 	/* Embed the event fields inside the cloned skb.  */
713 	event = sctp_skb2event(skb);
714 
715 	/* Initialize event with flags 0  and correct length
716 	 * Since this is a clone of the original skb, only account for
717 	 * the data of this chunk as other chunks will be accounted separately.
718 	 */
719 	sctp_ulpevent_init(event, 0, skb->len + sizeof(struct sk_buff));
720 
721 	sctp_ulpevent_receive_data(event, asoc);
722 
723 	event->stream = ntohs(chunk->subh.data_hdr->stream);
724 	event->ssn = ntohs(chunk->subh.data_hdr->ssn);
725 	event->ppid = chunk->subh.data_hdr->ppid;
726 	if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
727 		event->flags |= SCTP_UNORDERED;
728 		event->cumtsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
729 	}
730 	event->tsn = ntohl(chunk->subh.data_hdr->tsn);
731 	event->msg_flags |= chunk->chunk_hdr->flags;
732 	event->iif = sctp_chunk_iif(chunk);
733 
734 fail:
735 	return event;
736 }
737 
738 /* Create a partial delivery related event.
739  *
740  * 5.3.1.7 SCTP_PARTIAL_DELIVERY_EVENT
741  *
742  *   When a receiver is engaged in a partial delivery of a
743  *   message this notification will be used to indicate
744  *   various events.
745  */
746 struct sctp_ulpevent *sctp_ulpevent_make_pdapi(
747 	const struct sctp_association *asoc, __u32 indication,
748 	gfp_t gfp)
749 {
750 	struct sctp_ulpevent *event;
751 	struct sctp_pdapi_event *pd;
752 	struct sk_buff *skb;
753 
754 	event = sctp_ulpevent_new(sizeof(struct sctp_pdapi_event),
755 				  MSG_NOTIFICATION, gfp);
756 	if (!event)
757 		goto fail;
758 
759 	skb = sctp_event2skb(event);
760 	pd = (struct sctp_pdapi_event *)
761 		skb_put(skb, sizeof(struct sctp_pdapi_event));
762 
763 	/* pdapi_type
764 	 *   It should be SCTP_PARTIAL_DELIVERY_EVENT
765 	 *
766 	 * pdapi_flags: 16 bits (unsigned integer)
767 	 *   Currently unused.
768 	 */
769 	pd->pdapi_type = SCTP_PARTIAL_DELIVERY_EVENT;
770 	pd->pdapi_flags = 0;
771 
772 	/* pdapi_length: 32 bits (unsigned integer)
773 	 *
774 	 * This field is the total length of the notification data, including
775 	 * the notification header.  It will generally be sizeof (struct
776 	 * sctp_pdapi_event).
777 	 */
778 	pd->pdapi_length = sizeof(struct sctp_pdapi_event);
779 
780 	/*  pdapi_indication: 32 bits (unsigned integer)
781 	 *
782 	 * This field holds the indication being sent to the application.
783 	 */
784 	pd->pdapi_indication = indication;
785 
786 	/*  pdapi_assoc_id: sizeof (sctp_assoc_t)
787 	 *
788 	 * The association id field, holds the identifier for the association.
789 	 */
790 	sctp_ulpevent_set_owner(event, asoc);
791 	pd->pdapi_assoc_id = sctp_assoc2id(asoc);
792 
793 	return event;
794 fail:
795 	return NULL;
796 }
797 
798 /* Return the notification type, assuming this is a notification
799  * event.
800  */
801 __u16 sctp_ulpevent_get_notification_type(const struct sctp_ulpevent *event)
802 {
803 	union sctp_notification *notification;
804 	struct sk_buff *skb;
805 
806 	skb = sctp_event2skb((struct sctp_ulpevent *)event);
807 	notification = (union sctp_notification *) skb->data;
808 	return notification->sn_header.sn_type;
809 }
810 
811 /* Copy out the sndrcvinfo into a msghdr.  */
812 void sctp_ulpevent_read_sndrcvinfo(const struct sctp_ulpevent *event,
813 				   struct msghdr *msghdr)
814 {
815 	struct sctp_sndrcvinfo sinfo;
816 
817 	if (sctp_ulpevent_is_notification(event))
818 		return;
819 
820 	/* Sockets API Extensions for SCTP
821 	 * Section 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
822 	 *
823 	 * sinfo_stream: 16 bits (unsigned integer)
824 	 *
825 	 * For recvmsg() the SCTP stack places the message's stream number in
826 	 * this value.
827 	*/
828 	sinfo.sinfo_stream = event->stream;
829 	/* sinfo_ssn: 16 bits (unsigned integer)
830 	 *
831 	 * For recvmsg() this value contains the stream sequence number that
832 	 * the remote endpoint placed in the DATA chunk.  For fragmented
833 	 * messages this is the same number for all deliveries of the message
834 	 * (if more than one recvmsg() is needed to read the message).
835 	 */
836 	sinfo.sinfo_ssn = event->ssn;
837 	/* sinfo_ppid: 32 bits (unsigned integer)
838 	 *
839 	 * In recvmsg() this value is
840 	 * the same information that was passed by the upper layer in the peer
841 	 * application.  Please note that byte order issues are NOT accounted
842 	 * for and this information is passed opaquely by the SCTP stack from
843 	 * one end to the other.
844 	 */
845 	sinfo.sinfo_ppid = event->ppid;
846 	/* sinfo_flags: 16 bits (unsigned integer)
847 	 *
848 	 * This field may contain any of the following flags and is composed of
849 	 * a bitwise OR of these values.
850 	 *
851 	 * recvmsg() flags:
852 	 *
853 	 * SCTP_UNORDERED - This flag is present when the message was sent
854 	 *                 non-ordered.
855 	 */
856 	sinfo.sinfo_flags = event->flags;
857 	/* sinfo_tsn: 32 bit (unsigned integer)
858 	 *
859 	 * For the receiving side, this field holds a TSN that was
860 	 * assigned to one of the SCTP Data Chunks.
861 	 */
862 	sinfo.sinfo_tsn = event->tsn;
863 	/* sinfo_cumtsn: 32 bit (unsigned integer)
864 	 *
865 	 * This field will hold the current cumulative TSN as
866 	 * known by the underlying SCTP layer.  Note this field is
867 	 * ignored when sending and only valid for a receive
868 	 * operation when sinfo_flags are set to SCTP_UNORDERED.
869 	 */
870 	sinfo.sinfo_cumtsn = event->cumtsn;
871 	/* sinfo_assoc_id: sizeof (sctp_assoc_t)
872 	 *
873 	 * The association handle field, sinfo_assoc_id, holds the identifier
874 	 * for the association announced in the COMMUNICATION_UP notification.
875 	 * All notifications for a given association have the same identifier.
876 	 * Ignored for one-to-one style sockets.
877 	 */
878 	sinfo.sinfo_assoc_id = sctp_assoc2id(event->asoc);
879 
880 	/* context value that is set via SCTP_CONTEXT socket option. */
881 	sinfo.sinfo_context = event->asoc->default_rcv_context;
882 
883 	/* These fields are not used while receiving. */
884 	sinfo.sinfo_timetolive = 0;
885 
886 	put_cmsg(msghdr, IPPROTO_SCTP, SCTP_SNDRCV,
887 		 sizeof(struct sctp_sndrcvinfo), (void *)&sinfo);
888 }
889 
890 /* Do accounting for bytes received and hold a reference to the association
891  * for each skb.
892  */
893 static void sctp_ulpevent_receive_data(struct sctp_ulpevent *event,
894 				       struct sctp_association *asoc)
895 {
896 	struct sk_buff *skb, *frag;
897 
898 	skb = sctp_event2skb(event);
899 	/* Set the owner and charge rwnd for bytes received.  */
900 	sctp_ulpevent_set_owner(event, asoc);
901 	sctp_assoc_rwnd_decrease(asoc, skb_headlen(skb));
902 
903 	if (!skb->data_len)
904 		return;
905 
906 	/* Note:  Not clearing the entire event struct as this is just a
907 	 * fragment of the real event.  However, we still need to do rwnd
908 	 * accounting.
909 	 * In general, the skb passed from IP can have only 1 level of
910 	 * fragments. But we allow multiple levels of fragments.
911 	 */
912 	for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
913 		sctp_ulpevent_receive_data(sctp_skb2event(frag), asoc);
914 	}
915 }
916 
917 /* Do accounting for bytes just read by user and release the references to
918  * the association.
919  */
920 static void sctp_ulpevent_release_data(struct sctp_ulpevent *event)
921 {
922 	struct sk_buff *skb, *frag;
923 	unsigned int	len;
924 
925 	/* Current stack structures assume that the rcv buffer is
926 	 * per socket.   For UDP style sockets this is not true as
927 	 * multiple associations may be on a single UDP-style socket.
928 	 * Use the local private area of the skb to track the owning
929 	 * association.
930 	 */
931 
932 	skb = sctp_event2skb(event);
933 	len = skb->len;
934 
935 	if (!skb->data_len)
936 		goto done;
937 
938 	/* Don't forget the fragments. */
939 	for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
940 		/* NOTE:  skb_shinfos are recursive. Although IP returns
941 		 * skb's with only 1 level of fragments, SCTP reassembly can
942 		 * increase the levels.
943 		 */
944 		sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
945 	}
946 
947 done:
948 	sctp_assoc_rwnd_increase(event->asoc, len);
949 	sctp_ulpevent_release_owner(event);
950 }
951 
952 static void sctp_ulpevent_release_frag_data(struct sctp_ulpevent *event)
953 {
954 	struct sk_buff *skb, *frag;
955 
956 	skb = sctp_event2skb(event);
957 
958 	if (!skb->data_len)
959 		goto done;
960 
961 	/* Don't forget the fragments. */
962 	for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
963 		/* NOTE:  skb_shinfos are recursive. Although IP returns
964 		 * skb's with only 1 level of fragments, SCTP reassembly can
965 		 * increase the levels.
966 		 */
967 		sctp_ulpevent_release_frag_data(sctp_skb2event(frag));
968 	}
969 
970 done:
971 	sctp_ulpevent_release_owner(event);
972 }
973 
974 /* Free a ulpevent that has an owner.  It includes releasing the reference
975  * to the owner, updating the rwnd in case of a DATA event and freeing the
976  * skb.
977  */
978 void sctp_ulpevent_free(struct sctp_ulpevent *event)
979 {
980 	if (sctp_ulpevent_is_notification(event))
981 		sctp_ulpevent_release_owner(event);
982 	else
983 		sctp_ulpevent_release_data(event);
984 
985 	kfree_skb(sctp_event2skb(event));
986 }
987 
988 /* Purge the skb lists holding ulpevents. */
989 void sctp_queue_purge_ulpevents(struct sk_buff_head *list)
990 {
991 	struct sk_buff *skb;
992 	while ((skb = skb_dequeue(list)) != NULL)
993 		sctp_ulpevent_free(sctp_skb2event(skb));
994 }
995