ia64/linux-2.6.18-xen.hg

view net/sctp/ulpqueue.c @ 871:9cbcc9008446

xen/x86: don't initialize cpu_data[]'s apicid field on generic code

Afaict, this is not only redundant with the intialization done in
drivers/xen/core/smpboot.c, but actually results - at least for
secondary CPUs - in the Xen-specific value written to be later
overwritten with whatever the generic code determines (with no
guarantee that the two values are identical).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu May 14 10:09:15 2009 +0100 (2009-05-14)
parents 831230e53067
children
line source
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 * This abstraction carries sctp events to the ULP (sockets).
10 *
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 * Sridhar Samudrala <sri@us.ibm.com>
39 *
40 * Any bugs reported given to us we will try to fix... any fixes shared will
41 * be incorporated into the next SCTP release.
42 */
44 #include <linux/types.h>
45 #include <linux/skbuff.h>
46 #include <net/sock.h>
47 #include <net/sctp/structs.h>
48 #include <net/sctp/sctp.h>
49 #include <net/sctp/sm.h>
51 /* Forward declarations for internal helpers. */
52 static struct sctp_ulpevent * sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
53 struct sctp_ulpevent *);
54 static struct sctp_ulpevent * sctp_ulpq_order(struct sctp_ulpq *,
55 struct sctp_ulpevent *);
57 /* 1st Level Abstractions */
59 /* Initialize a ULP queue from a block of memory. */
60 struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq,
61 struct sctp_association *asoc)
62 {
63 memset(ulpq, 0, sizeof(struct sctp_ulpq));
65 ulpq->asoc = asoc;
66 skb_queue_head_init(&ulpq->reasm);
67 skb_queue_head_init(&ulpq->lobby);
68 ulpq->pd_mode = 0;
69 ulpq->malloced = 0;
71 return ulpq;
72 }
75 /* Flush the reassembly and ordering queues. */
76 static void sctp_ulpq_flush(struct sctp_ulpq *ulpq)
77 {
78 struct sk_buff *skb;
79 struct sctp_ulpevent *event;
81 while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) {
82 event = sctp_skb2event(skb);
83 sctp_ulpevent_free(event);
84 }
86 while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) {
87 event = sctp_skb2event(skb);
88 sctp_ulpevent_free(event);
89 }
91 }
93 /* Dispose of a ulpqueue. */
94 void sctp_ulpq_free(struct sctp_ulpq *ulpq)
95 {
96 sctp_ulpq_flush(ulpq);
97 if (ulpq->malloced)
98 kfree(ulpq);
99 }
101 /* Process an incoming DATA chunk. */
102 int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
103 gfp_t gfp)
104 {
105 struct sk_buff_head temp;
106 sctp_data_chunk_t *hdr;
107 struct sctp_ulpevent *event;
109 hdr = (sctp_data_chunk_t *) chunk->chunk_hdr;
111 /* Create an event from the incoming chunk. */
112 event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp);
113 if (!event)
114 return -ENOMEM;
116 /* Do reassembly if needed. */
117 event = sctp_ulpq_reasm(ulpq, event);
119 /* Do ordering if needed. */
120 if ((event) && (event->msg_flags & MSG_EOR)){
121 /* Create a temporary list to collect chunks on. */
122 skb_queue_head_init(&temp);
123 __skb_queue_tail(&temp, sctp_event2skb(event));
125 event = sctp_ulpq_order(ulpq, event);
126 }
128 /* Send event to the ULP. 'event' is the sctp_ulpevent for
129 * very first SKB on the 'temp' list.
130 */
131 if (event)
132 sctp_ulpq_tail_event(ulpq, event);
134 return 0;
135 }
137 /* Add a new event for propagation to the ULP. */
138 /* Clear the partial delivery mode for this socket. Note: This
139 * assumes that no association is currently in partial delivery mode.
140 */
141 int sctp_clear_pd(struct sock *sk)
142 {
143 struct sctp_sock *sp = sctp_sk(sk);
145 sp->pd_mode = 0;
146 if (!skb_queue_empty(&sp->pd_lobby)) {
147 struct list_head *list;
148 sctp_skb_list_tail(&sp->pd_lobby, &sk->sk_receive_queue);
149 list = (struct list_head *)&sctp_sk(sk)->pd_lobby;
150 INIT_LIST_HEAD(list);
151 return 1;
152 }
153 return 0;
154 }
156 /* Clear the pd_mode and restart any pending messages waiting for delivery. */
157 static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq)
158 {
159 ulpq->pd_mode = 0;
160 return sctp_clear_pd(ulpq->asoc->base.sk);
161 }
163 /* If the SKB of 'event' is on a list, it is the first such member
164 * of that list.
165 */
166 int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event)
167 {
168 struct sock *sk = ulpq->asoc->base.sk;
169 struct sk_buff_head *queue, *skb_list;
170 struct sk_buff *skb = sctp_event2skb(event);
171 int clear_pd = 0;
173 skb_list = (struct sk_buff_head *) skb->prev;
175 /* If the socket is just going to throw this away, do not
176 * even try to deliver it.
177 */
178 if (sock_flag(sk, SOCK_DEAD) || (sk->sk_shutdown & RCV_SHUTDOWN))
179 goto out_free;
181 /* Check if the user wishes to receive this event. */
182 if (!sctp_ulpevent_is_enabled(event, &sctp_sk(sk)->subscribe))
183 goto out_free;
185 /* If we are in partial delivery mode, post to the lobby until
186 * partial delivery is cleared, unless, of course _this_ is
187 * the association the cause of the partial delivery.
188 */
190 if (!sctp_sk(sk)->pd_mode) {
191 queue = &sk->sk_receive_queue;
192 } else if (ulpq->pd_mode) {
193 if (event->msg_flags & MSG_NOTIFICATION)
194 queue = &sctp_sk(sk)->pd_lobby;
195 else {
196 clear_pd = event->msg_flags & MSG_EOR;
197 queue = &sk->sk_receive_queue;
198 }
199 } else
200 queue = &sctp_sk(sk)->pd_lobby;
203 /* If we are harvesting multiple skbs they will be
204 * collected on a list.
205 */
206 if (skb_list)
207 sctp_skb_list_tail(skb_list, queue);
208 else
209 __skb_queue_tail(queue, skb);
211 /* Did we just complete partial delivery and need to get
212 * rolling again? Move pending data to the receive
213 * queue.
214 */
215 if (clear_pd)
216 sctp_ulpq_clear_pd(ulpq);
218 if (queue == &sk->sk_receive_queue)
219 sk->sk_data_ready(sk, 0);
220 return 1;
222 out_free:
223 if (skb_list)
224 sctp_queue_purge_ulpevents(skb_list);
225 else
226 sctp_ulpevent_free(event);
228 return 0;
229 }
231 /* 2nd Level Abstractions */
233 /* Helper function to store chunks that need to be reassembled. */
234 static inline void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq,
235 struct sctp_ulpevent *event)
236 {
237 struct sk_buff *pos;
238 struct sctp_ulpevent *cevent;
239 __u32 tsn, ctsn;
241 tsn = event->tsn;
243 /* See if it belongs at the end. */
244 pos = skb_peek_tail(&ulpq->reasm);
245 if (!pos) {
246 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
247 return;
248 }
250 /* Short circuit just dropping it at the end. */
251 cevent = sctp_skb2event(pos);
252 ctsn = cevent->tsn;
253 if (TSN_lt(ctsn, tsn)) {
254 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
255 return;
256 }
258 /* Find the right place in this list. We store them by TSN. */
259 skb_queue_walk(&ulpq->reasm, pos) {
260 cevent = sctp_skb2event(pos);
261 ctsn = cevent->tsn;
263 if (TSN_lt(tsn, ctsn))
264 break;
265 }
267 /* Insert before pos. */
268 __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->reasm);
270 }
272 /* Helper function to return an event corresponding to the reassembled
273 * datagram.
274 * This routine creates a re-assembled skb given the first and last skb's
275 * as stored in the reassembly queue. The skb's may be non-linear if the sctp
276 * payload was fragmented on the way and ip had to reassemble them.
277 * We add the rest of skb's to the first skb's fraglist.
278 */
279 static struct sctp_ulpevent *sctp_make_reassembled_event(struct sk_buff_head *queue, struct sk_buff *f_frag, struct sk_buff *l_frag)
280 {
281 struct sk_buff *pos;
282 struct sk_buff *new = NULL;
283 struct sctp_ulpevent *event;
284 struct sk_buff *pnext, *last;
285 struct sk_buff *list = skb_shinfo(f_frag)->frag_list;
287 /* Store the pointer to the 2nd skb */
288 if (f_frag == l_frag)
289 pos = NULL;
290 else
291 pos = f_frag->next;
293 /* Get the last skb in the f_frag's frag_list if present. */
294 for (last = list; list; last = list, list = list->next);
296 /* Add the list of remaining fragments to the first fragments
297 * frag_list.
298 */
299 if (last)
300 last->next = pos;
301 else {
302 if (skb_cloned(f_frag)) {
303 /* This is a cloned skb, we can't just modify
304 * the frag_list. We need a new skb to do that.
305 * Instead of calling skb_unshare(), we'll do it
306 * ourselves since we need to delay the free.
307 */
308 new = skb_copy(f_frag, GFP_ATOMIC);
309 if (!new)
310 return NULL; /* try again later */
312 new->sk = f_frag->sk;
314 skb_shinfo(new)->frag_list = pos;
315 } else
316 skb_shinfo(f_frag)->frag_list = pos;
317 }
319 /* Remove the first fragment from the reassembly queue. */
320 __skb_unlink(f_frag, queue);
322 /* if we did unshare, then free the old skb and re-assign */
323 if (new) {
324 kfree_skb(f_frag);
325 f_frag = new;
326 }
328 while (pos) {
330 pnext = pos->next;
332 /* Update the len and data_len fields of the first fragment. */
333 f_frag->len += pos->len;
334 f_frag->data_len += pos->len;
336 /* Remove the fragment from the reassembly queue. */
337 __skb_unlink(pos, queue);
339 /* Break if we have reached the last fragment. */
340 if (pos == l_frag)
341 break;
342 pos->next = pnext;
343 pos = pnext;
344 };
346 event = sctp_skb2event(f_frag);
347 SCTP_INC_STATS(SCTP_MIB_REASMUSRMSGS);
349 return event;
350 }
353 /* Helper function to check if an incoming chunk has filled up the last
354 * missing fragment in a SCTP datagram and return the corresponding event.
355 */
356 static inline struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq)
357 {
358 struct sk_buff *pos;
359 struct sctp_ulpevent *cevent;
360 struct sk_buff *first_frag = NULL;
361 __u32 ctsn, next_tsn;
362 struct sctp_ulpevent *retval = NULL;
364 /* Initialized to 0 just to avoid compiler warning message. Will
365 * never be used with this value. It is referenced only after it
366 * is set when we find the first fragment of a message.
367 */
368 next_tsn = 0;
370 /* The chunks are held in the reasm queue sorted by TSN.
371 * Walk through the queue sequentially and look for a sequence of
372 * fragmented chunks that complete a datagram.
373 * 'first_frag' and next_tsn are reset when we find a chunk which
374 * is the first fragment of a datagram. Once these 2 fields are set
375 * we expect to find the remaining middle fragments and the last
376 * fragment in order. If not, first_frag is reset to NULL and we
377 * start the next pass when we find another first fragment.
378 */
379 skb_queue_walk(&ulpq->reasm, pos) {
380 cevent = sctp_skb2event(pos);
381 ctsn = cevent->tsn;
383 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
384 case SCTP_DATA_FIRST_FRAG:
385 first_frag = pos;
386 next_tsn = ctsn + 1;
387 break;
389 case SCTP_DATA_MIDDLE_FRAG:
390 if ((first_frag) && (ctsn == next_tsn))
391 next_tsn++;
392 else
393 first_frag = NULL;
394 break;
396 case SCTP_DATA_LAST_FRAG:
397 if (first_frag && (ctsn == next_tsn))
398 goto found;
399 else
400 first_frag = NULL;
401 break;
402 };
404 }
405 done:
406 return retval;
407 found:
408 retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, pos);
409 if (retval)
410 retval->msg_flags |= MSG_EOR;
411 goto done;
412 }
414 /* Retrieve the next set of fragments of a partial message. */
415 static inline struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq)
416 {
417 struct sk_buff *pos, *last_frag, *first_frag;
418 struct sctp_ulpevent *cevent;
419 __u32 ctsn, next_tsn;
420 int is_last;
421 struct sctp_ulpevent *retval;
423 /* The chunks are held in the reasm queue sorted by TSN.
424 * Walk through the queue sequentially and look for the first
425 * sequence of fragmented chunks.
426 */
428 if (skb_queue_empty(&ulpq->reasm))
429 return NULL;
431 last_frag = first_frag = NULL;
432 retval = NULL;
433 next_tsn = 0;
434 is_last = 0;
436 skb_queue_walk(&ulpq->reasm, pos) {
437 cevent = sctp_skb2event(pos);
438 ctsn = cevent->tsn;
440 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
441 case SCTP_DATA_MIDDLE_FRAG:
442 if (!first_frag) {
443 first_frag = pos;
444 next_tsn = ctsn + 1;
445 last_frag = pos;
446 } else if (next_tsn == ctsn)
447 next_tsn++;
448 else
449 goto done;
450 break;
451 case SCTP_DATA_LAST_FRAG:
452 if (!first_frag)
453 first_frag = pos;
454 else if (ctsn != next_tsn)
455 goto done;
456 last_frag = pos;
457 is_last = 1;
458 goto done;
459 default:
460 return NULL;
461 };
462 }
464 /* We have the reassembled event. There is no need to look
465 * further.
466 */
467 done:
468 retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, last_frag);
469 if (retval && is_last)
470 retval->msg_flags |= MSG_EOR;
472 return retval;
473 }
476 /* Helper function to reassemble chunks. Hold chunks on the reasm queue that
477 * need reassembling.
478 */
479 static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
480 struct sctp_ulpevent *event)
481 {
482 struct sctp_ulpevent *retval = NULL;
484 /* Check if this is part of a fragmented message. */
485 if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
486 event->msg_flags |= MSG_EOR;
487 return event;
488 }
490 sctp_ulpq_store_reasm(ulpq, event);
491 if (!ulpq->pd_mode)
492 retval = sctp_ulpq_retrieve_reassembled(ulpq);
493 else {
494 __u32 ctsn, ctsnap;
496 /* Do not even bother unless this is the next tsn to
497 * be delivered.
498 */
499 ctsn = event->tsn;
500 ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map);
501 if (TSN_lte(ctsn, ctsnap))
502 retval = sctp_ulpq_retrieve_partial(ulpq);
503 }
505 return retval;
506 }
508 /* Retrieve the first part (sequential fragments) for partial delivery. */
509 static inline struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq)
510 {
511 struct sk_buff *pos, *last_frag, *first_frag;
512 struct sctp_ulpevent *cevent;
513 __u32 ctsn, next_tsn;
514 struct sctp_ulpevent *retval;
516 /* The chunks are held in the reasm queue sorted by TSN.
517 * Walk through the queue sequentially and look for a sequence of
518 * fragmented chunks that start a datagram.
519 */
521 if (skb_queue_empty(&ulpq->reasm))
522 return NULL;
524 last_frag = first_frag = NULL;
525 retval = NULL;
526 next_tsn = 0;
528 skb_queue_walk(&ulpq->reasm, pos) {
529 cevent = sctp_skb2event(pos);
530 ctsn = cevent->tsn;
532 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
533 case SCTP_DATA_FIRST_FRAG:
534 if (!first_frag) {
535 first_frag = pos;
536 next_tsn = ctsn + 1;
537 last_frag = pos;
538 } else
539 goto done;
540 break;
542 case SCTP_DATA_MIDDLE_FRAG:
543 if (!first_frag)
544 return NULL;
545 if (ctsn == next_tsn) {
546 next_tsn++;
547 last_frag = pos;
548 } else
549 goto done;
550 break;
551 default:
552 return NULL;
553 };
554 }
556 /* We have the reassembled event. There is no need to look
557 * further.
558 */
559 done:
560 retval = sctp_make_reassembled_event(&ulpq->reasm, first_frag, last_frag);
561 return retval;
562 }
564 /* Helper function to gather skbs that have possibly become
565 * ordered by an an incoming chunk.
566 */
567 static inline void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq,
568 struct sctp_ulpevent *event)
569 {
570 struct sk_buff_head *event_list;
571 struct sk_buff *pos, *tmp;
572 struct sctp_ulpevent *cevent;
573 struct sctp_stream *in;
574 __u16 sid, csid;
575 __u16 ssn, cssn;
577 sid = event->stream;
578 ssn = event->ssn;
579 in = &ulpq->asoc->ssnmap->in;
581 event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev;
583 /* We are holding the chunks by stream, by SSN. */
584 sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
585 cevent = (struct sctp_ulpevent *) pos->cb;
586 csid = cevent->stream;
587 cssn = cevent->ssn;
589 /* Have we gone too far? */
590 if (csid > sid)
591 break;
593 /* Have we not gone far enough? */
594 if (csid < sid)
595 continue;
597 if (cssn != sctp_ssn_peek(in, sid))
598 break;
600 /* Found it, so mark in the ssnmap. */
601 sctp_ssn_next(in, sid);
603 __skb_unlink(pos, &ulpq->lobby);
605 /* Attach all gathered skbs to the event. */
606 __skb_queue_tail(event_list, pos);
607 }
608 }
610 /* Helper function to store chunks needing ordering. */
611 static inline void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq,
612 struct sctp_ulpevent *event)
613 {
614 struct sk_buff *pos;
615 struct sctp_ulpevent *cevent;
616 __u16 sid, csid;
617 __u16 ssn, cssn;
619 pos = skb_peek_tail(&ulpq->lobby);
620 if (!pos) {
621 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
622 return;
623 }
625 sid = event->stream;
626 ssn = event->ssn;
628 cevent = (struct sctp_ulpevent *) pos->cb;
629 csid = cevent->stream;
630 cssn = cevent->ssn;
631 if (sid > csid) {
632 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
633 return;
634 }
636 if ((sid == csid) && SSN_lt(cssn, ssn)) {
637 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
638 return;
639 }
641 /* Find the right place in this list. We store them by
642 * stream ID and then by SSN.
643 */
644 skb_queue_walk(&ulpq->lobby, pos) {
645 cevent = (struct sctp_ulpevent *) pos->cb;
646 csid = cevent->stream;
647 cssn = cevent->ssn;
649 if (csid > sid)
650 break;
651 if (csid == sid && SSN_lt(ssn, cssn))
652 break;
653 }
656 /* Insert before pos. */
657 __skb_insert(sctp_event2skb(event), pos->prev, pos, &ulpq->lobby);
659 }
661 static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq,
662 struct sctp_ulpevent *event)
663 {
664 __u16 sid, ssn;
665 struct sctp_stream *in;
667 /* Check if this message needs ordering. */
668 if (SCTP_DATA_UNORDERED & event->msg_flags)
669 return event;
671 /* Note: The stream ID must be verified before this routine. */
672 sid = event->stream;
673 ssn = event->ssn;
674 in = &ulpq->asoc->ssnmap->in;
676 /* Is this the expected SSN for this stream ID? */
677 if (ssn != sctp_ssn_peek(in, sid)) {
678 /* We've received something out of order, so find where it
679 * needs to be placed. We order by stream and then by SSN.
680 */
681 sctp_ulpq_store_ordered(ulpq, event);
682 return NULL;
683 }
685 /* Mark that the next chunk has been found. */
686 sctp_ssn_next(in, sid);
688 /* Go find any other chunks that were waiting for
689 * ordering.
690 */
691 sctp_ulpq_retrieve_ordered(ulpq, event);
693 return event;
694 }
696 /* Helper function to gather skbs that have possibly become
697 * ordered by forward tsn skipping their dependencies.
698 */
699 static inline void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq)
700 {
701 struct sk_buff *pos, *tmp;
702 struct sctp_ulpevent *cevent;
703 struct sctp_ulpevent *event;
704 struct sctp_stream *in;
705 struct sk_buff_head temp;
706 __u16 csid, cssn;
708 in = &ulpq->asoc->ssnmap->in;
710 /* We are holding the chunks by stream, by SSN. */
711 skb_queue_head_init(&temp);
712 event = NULL;
713 sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
714 cevent = (struct sctp_ulpevent *) pos->cb;
715 csid = cevent->stream;
716 cssn = cevent->ssn;
718 if (cssn != sctp_ssn_peek(in, csid))
719 break;
721 /* Found it, so mark in the ssnmap. */
722 sctp_ssn_next(in, csid);
724 __skb_unlink(pos, &ulpq->lobby);
725 if (!event) {
726 /* Create a temporary list to collect chunks on. */
727 event = sctp_skb2event(pos);
728 __skb_queue_tail(&temp, sctp_event2skb(event));
729 } else {
730 /* Attach all gathered skbs to the event. */
731 __skb_queue_tail(&temp, pos);
732 }
733 }
735 /* Send event to the ULP. 'event' is the sctp_ulpevent for
736 * very first SKB on the 'temp' list.
737 */
738 if (event)
739 sctp_ulpq_tail_event(ulpq, event);
740 }
742 /* Skip over an SSN. */
743 void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn)
744 {
745 struct sctp_stream *in;
747 /* Note: The stream ID must be verified before this routine. */
748 in = &ulpq->asoc->ssnmap->in;
750 /* Is this an old SSN? If so ignore. */
751 if (SSN_lt(ssn, sctp_ssn_peek(in, sid)))
752 return;
754 /* Mark that we are no longer expecting this SSN or lower. */
755 sctp_ssn_skip(in, sid, ssn);
757 /* Go find any other chunks that were waiting for
758 * ordering and deliver them if needed.
759 */
760 sctp_ulpq_reap_ordered(ulpq);
761 return;
762 }
764 /* Renege 'needed' bytes from the ordering queue. */
765 static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed)
766 {
767 __u16 freed = 0;
768 __u32 tsn;
769 struct sk_buff *skb;
770 struct sctp_ulpevent *event;
771 struct sctp_tsnmap *tsnmap;
773 tsnmap = &ulpq->asoc->peer.tsn_map;
775 while ((skb = __skb_dequeue_tail(&ulpq->lobby)) != NULL) {
776 freed += skb_headlen(skb);
777 event = sctp_skb2event(skb);
778 tsn = event->tsn;
780 sctp_ulpevent_free(event);
781 sctp_tsnmap_renege(tsnmap, tsn);
782 if (freed >= needed)
783 return freed;
784 }
786 return freed;
787 }
789 /* Renege 'needed' bytes from the reassembly queue. */
790 static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed)
791 {
792 __u16 freed = 0;
793 __u32 tsn;
794 struct sk_buff *skb;
795 struct sctp_ulpevent *event;
796 struct sctp_tsnmap *tsnmap;
798 tsnmap = &ulpq->asoc->peer.tsn_map;
800 /* Walk backwards through the list, reneges the newest tsns. */
801 while ((skb = __skb_dequeue_tail(&ulpq->reasm)) != NULL) {
802 freed += skb_headlen(skb);
803 event = sctp_skb2event(skb);
804 tsn = event->tsn;
806 sctp_ulpevent_free(event);
807 sctp_tsnmap_renege(tsnmap, tsn);
808 if (freed >= needed)
809 return freed;
810 }
812 return freed;
813 }
815 /* Partial deliver the first message as there is pressure on rwnd. */
816 void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq,
817 struct sctp_chunk *chunk,
818 gfp_t gfp)
819 {
820 struct sctp_ulpevent *event;
821 struct sctp_association *asoc;
823 asoc = ulpq->asoc;
825 /* Are we already in partial delivery mode? */
826 if (!sctp_sk(asoc->base.sk)->pd_mode) {
828 /* Is partial delivery possible? */
829 event = sctp_ulpq_retrieve_first(ulpq);
830 /* Send event to the ULP. */
831 if (event) {
832 sctp_ulpq_tail_event(ulpq, event);
833 sctp_sk(asoc->base.sk)->pd_mode = 1;
834 ulpq->pd_mode = 1;
835 return;
836 }
837 }
838 }
840 /* Renege some packets to make room for an incoming chunk. */
841 void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
842 gfp_t gfp)
843 {
844 struct sctp_association *asoc;
845 __u16 needed, freed;
847 asoc = ulpq->asoc;
849 if (chunk) {
850 needed = ntohs(chunk->chunk_hdr->length);
851 needed -= sizeof(sctp_data_chunk_t);
852 } else
853 needed = SCTP_DEFAULT_MAXWINDOW;
855 freed = 0;
857 if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
858 freed = sctp_ulpq_renege_order(ulpq, needed);
859 if (freed < needed) {
860 freed += sctp_ulpq_renege_frags(ulpq, needed - freed);
861 }
862 }
863 /* If able to free enough room, accept this chunk. */
864 if (chunk && (freed >= needed)) {
865 __u32 tsn;
866 tsn = ntohl(chunk->subh.data_hdr->tsn);
867 sctp_tsnmap_mark(&asoc->peer.tsn_map, tsn);
868 sctp_ulpq_tail_data(ulpq, chunk, gfp);
870 sctp_ulpq_partial_delivery(ulpq, chunk, gfp);
871 }
873 return;
874 }
878 /* Notify the application if an association is aborted and in
879 * partial delivery mode. Send up any pending received messages.
880 */
881 void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
882 {
883 struct sctp_ulpevent *ev = NULL;
884 struct sock *sk;
886 if (!ulpq->pd_mode)
887 return;
889 sk = ulpq->asoc->base.sk;
890 if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT,
891 &sctp_sk(sk)->subscribe))
892 ev = sctp_ulpevent_make_pdapi(ulpq->asoc,
893 SCTP_PARTIAL_DELIVERY_ABORTED,
894 gfp);
895 if (ev)
896 __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
898 /* If there is data waiting, send it up the socket now. */
899 if (sctp_ulpq_clear_pd(ulpq) || ev)
900 sk->sk_data_ready(sk, 0);
901 }