1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3 * (C) Copyright Red Hat Inc. 2017
4 *
5 * This file is part of the SCTP kernel implementation
6 *
7 * These functions implement sctp stream message interleaving, mostly
8 * including I-DATA and I-FORWARD-TSN chunks process.
9 *
10 * Please send any bug reports or fixes you make to the
11 * email addresched(es):
12 * lksctp developers <linux-sctp@vger.kernel.org>
13 *
14 * Written or modified by:
15 * Xin Long <lucien.xin@gmail.com>
16 */
17
18 #include <net/busy_poll.h>
19 #include <net/sctp/sctp.h>
20 #include <net/sctp/sm.h>
21 #include <net/sctp/ulpevent.h>
22 #include <linux/sctp.h>
23
24 static struct sctp_chunk *sctp_make_idatafrag_empty(
25 const struct sctp_association *asoc,
26 const struct sctp_sndrcvinfo *sinfo,
27 int len, __u8 flags, gfp_t gfp)
28 {
29 struct sctp_chunk *retval;
30 struct sctp_idatahdr dp;
31
32 memset(&dp, 0, sizeof(dp));
33 dp.stream = htons(sinfo->sinfo_stream);
34
35 if (sinfo->sinfo_flags & SCTP_UNORDERED)
36 flags |= SCTP_DATA_UNORDERED;
37
38 retval = sctp_make_idata(asoc, flags, sizeof(dp) + len, gfp);
39 if (!retval)
40 return NULL;
41
42 retval->subh.idata_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
43 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
44
45 return retval;
46 }
47
48 static void sctp_chunk_assign_mid(struct sctp_chunk *chunk)
49 {
50 struct sctp_stream *stream;
51 struct sctp_chunk *lchunk;
52 __u32 cfsn = 0;
53 __u16 sid;
54
55 if (chunk->has_mid)
56 return;
57
58 sid = sctp_chunk_stream_no(chunk);
59 stream = &chunk->asoc->stream;
60
61 list_for_each_entry(lchunk, &chunk->msg->chunks, frag_list) {
62 struct sctp_idatahdr *hdr;
63 __u32 mid;
64
65 lchunk->has_mid = 1;
66
67 hdr = lchunk->subh.idata_hdr;
68
69 if (lchunk->chunk_hdr->flags & SCTP_DATA_FIRST_FRAG)
70 hdr->ppid = lchunk->sinfo.sinfo_ppid;
71 else
72 hdr->fsn = htonl(cfsn++);
73
74 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
75 mid = lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG ?
76 sctp_mid_uo_next(stream, out, sid) :
77 sctp_mid_uo_peek(stream, out, sid);
78 } else {
79 mid = lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG ?
80 sctp_mid_next(stream, out, sid) :
81 sctp_mid_peek(stream, out, sid);
82 }
83 hdr->mid = htonl(mid);
84 }
85 }
86
87 static bool sctp_validate_data(struct sctp_chunk *chunk)
88 {
89 struct sctp_stream *stream;
90 __u16 sid, ssn;
91
92 if (chunk->chunk_hdr->type != SCTP_CID_DATA)
93 return false;
94
95 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
96 return true;
97
98 stream = &chunk->asoc->stream;
99 sid = sctp_chunk_stream_no(chunk);
100 ssn = ntohs(chunk->subh.data_hdr->ssn);
101
102 return !SSN_lt(ssn, sctp_ssn_peek(stream, in, sid));
103 }
104
105 static bool sctp_validate_idata(struct sctp_chunk *chunk)
106 {
107 struct sctp_stream *stream;
108 __u32 mid;
109 __u16 sid;
110
111 if (chunk->chunk_hdr->type != SCTP_CID_I_DATA)
112 return false;
113
114 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
115 return true;
116
117 stream = &chunk->asoc->stream;
118 sid = sctp_chunk_stream_no(chunk);
119 mid = ntohl(chunk->subh.idata_hdr->mid);
120
121 return !MID_lt(mid, sctp_mid_peek(stream, in, sid));
122 }
123
124 static void sctp_intl_store_reasm(struct sctp_ulpq *ulpq,
125 struct sctp_ulpevent *event)
126 {
127 struct sctp_ulpevent *cevent;
128 struct sk_buff *pos, *loc;
129
130 pos = skb_peek_tail(&ulpq->reasm);
131 if (!pos) {
132 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
133 return;
134 }
135
136 cevent = sctp_skb2event(pos);
137
138 if (event->stream == cevent->stream &&
139 event->mid == cevent->mid &&
140 (cevent->msg_flags & SCTP_DATA_FIRST_FRAG ||
141 (!(event->msg_flags & SCTP_DATA_FIRST_FRAG) &&
142 event->fsn > cevent->fsn))) {
143 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
144 return;
145 }
146
147 if ((event->stream == cevent->stream &&
148 MID_lt(cevent->mid, event->mid)) ||
149 event->stream > cevent->stream) {
150 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
151 return;
152 }
153
154 loc = NULL;
155 skb_queue_walk(&ulpq->reasm, pos) {
156 cevent = sctp_skb2event(pos);
157
158 if (event->stream < cevent->stream ||
159 (event->stream == cevent->stream &&
160 MID_lt(event->mid, cevent->mid))) {
161 loc = pos;
162 break;
163 }
164 if (event->stream == cevent->stream &&
165 event->mid == cevent->mid &&
166 !(cevent->msg_flags & SCTP_DATA_FIRST_FRAG) &&
167 (event->msg_flags & SCTP_DATA_FIRST_FRAG ||
168 event->fsn < cevent->fsn)) {
169 loc = pos;
170 break;
171 }
172 }
173
174 if (!loc)
175 __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
176 else
177 __skb_queue_before(&ulpq->reasm, loc, sctp_event2skb(event));
178 }
179
180 static struct sctp_ulpevent *sctp_intl_retrieve_partial(
181 struct sctp_ulpq *ulpq,
182 struct sctp_ulpevent *event)
183 {
184 struct sk_buff *first_frag = NULL;
185 struct sk_buff *last_frag = NULL;
186 struct sctp_ulpevent *retval;
187 struct sctp_stream_in *sin;
188 struct sk_buff *pos;
189 __u32 next_fsn = 0;
190 int is_last = 0;
191
192 sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
193
194 skb_queue_walk(&ulpq->reasm, pos) {
195 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
196
197 if (cevent->stream < event->stream)
198 continue;
199
200 if (cevent->stream > event->stream ||
201 cevent->mid != sin->mid)
202 break;
203
204 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
205 case SCTP_DATA_FIRST_FRAG:
206 goto out;
207 case SCTP_DATA_MIDDLE_FRAG:
208 if (!first_frag) {
209 if (cevent->fsn == sin->fsn) {
210 first_frag = pos;
211 last_frag = pos;
212 next_fsn = cevent->fsn + 1;
213 }
214 } else if (cevent->fsn == next_fsn) {
215 last_frag = pos;
216 next_fsn++;
217 } else {
218 goto out;
219 }
220 break;
221 case SCTP_DATA_LAST_FRAG:
222 if (!first_frag) {
223 if (cevent->fsn == sin->fsn) {
224 first_frag = pos;
225 last_frag = pos;
226 next_fsn = 0;
227 is_last = 1;
228 }
229 } else if (cevent->fsn == next_fsn) {
230 last_frag = pos;
231 next_fsn = 0;
232 is_last = 1;
233 }
234 goto out;
235 default:
236 goto out;
237 }
238 }
239
240 out:
241 if (!first_frag)
242 return NULL;
243
244 retval = sctp_make_reassembled_event(ulpq->asoc->base.net, &ulpq->reasm,
245 first_frag, last_frag);
246 if (retval) {
247 sin->fsn = next_fsn;
248 if (is_last) {
249 retval->msg_flags |= MSG_EOR;
250 sin->pd_mode = 0;
251 }
252 }
253
254 return retval;
255 }
256
257 static struct sctp_ulpevent *sctp_intl_retrieve_reassembled(
258 struct sctp_ulpq *ulpq,
259 struct sctp_ulpevent *event)
260 {
261 struct sctp_association *asoc = ulpq->asoc;
262 struct sk_buff *pos, *first_frag = NULL;
263 struct sctp_ulpevent *retval = NULL;
264 struct sk_buff *pd_first = NULL;
265 struct sk_buff *pd_last = NULL;
266 struct sctp_stream_in *sin;
267 __u32 next_fsn = 0;
268 __u32 pd_point = 0;
269 __u32 pd_len = 0;
270 __u32 mid = 0;
271
272 sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
273
274 skb_queue_walk(&ulpq->reasm, pos) {
275 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
276
277 if (cevent->stream < event->stream)
278 continue;
279 if (cevent->stream > event->stream)
280 break;
281
282 if (MID_lt(cevent->mid, event->mid))
283 continue;
284 if (MID_lt(event->mid, cevent->mid))
285 break;
286
287 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
288 case SCTP_DATA_FIRST_FRAG:
289 if (cevent->mid == sin->mid) {
290 pd_first = pos;
291 pd_last = pos;
292 pd_len = pos->len;
293 }
294
295 first_frag = pos;
296 next_fsn = 0;
297 mid = cevent->mid;
298 break;
299
300 case SCTP_DATA_MIDDLE_FRAG:
301 if (first_frag && cevent->mid == mid &&
302 cevent->fsn == next_fsn) {
303 next_fsn++;
304 if (pd_first) {
305 pd_last = pos;
306 pd_len += pos->len;
307 }
308 } else {
309 first_frag = NULL;
310 }
311 break;
312
313 case SCTP_DATA_LAST_FRAG:
314 if (first_frag && cevent->mid == mid &&
315 cevent->fsn == next_fsn)
316 goto found;
317 else
318 first_frag = NULL;
319 break;
320 }
321 }
322
323 if (!pd_first)
324 goto out;
325
326 pd_point = sctp_sk(asoc->base.sk)->pd_point;
327 if (pd_point && pd_point <= pd_len) {
328 retval = sctp_make_reassembled_event(asoc->base.net,
329 &ulpq->reasm,
330 pd_first, pd_last);
331 if (retval) {
332 sin->fsn = next_fsn;
333 sin->pd_mode = 1;
334 }
335 }
336 goto out;
337
338 found:
339 retval = sctp_make_reassembled_event(asoc->base.net, &ulpq->reasm,
340 first_frag, pos);
341 if (retval)
342 retval->msg_flags |= MSG_EOR;
343
344 out:
345 return retval;
346 }
347
348 static struct sctp_ulpevent *sctp_intl_reasm(struct sctp_ulpq *ulpq,
349 struct sctp_ulpevent *event)
350 {
351 struct sctp_ulpevent *retval = NULL;
352 struct sctp_stream_in *sin;
353
354 if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
355 event->msg_flags |= MSG_EOR;
356 return event;
357 }
358
359 sctp_intl_store_reasm(ulpq, event);
360
361 sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
362 if (sin->pd_mode && event->mid == sin->mid &&
363 event->fsn == sin->fsn)
364 retval = sctp_intl_retrieve_partial(ulpq, event);
365
366 if (!retval)
367 retval = sctp_intl_retrieve_reassembled(ulpq, event);
368
369 return retval;
370 }
371
372 static void sctp_intl_store_ordered(struct sctp_ulpq *ulpq,
373 struct sctp_ulpevent *event)
374 {
375 struct sctp_ulpevent *cevent;
376 struct sk_buff *pos, *loc;
377
378 pos = skb_peek_tail(&ulpq->lobby);
379 if (!pos) {
380 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
381 return;
382 }
383
384 cevent = (struct sctp_ulpevent *)pos->cb;
385 if (event->stream == cevent->stream &&
386 MID_lt(cevent->mid, event->mid)) {
387 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
388 return;
389 }
390
391 if (event->stream > cevent->stream) {
392 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
393 return;
394 }
395
396 loc = NULL;
397 skb_queue_walk(&ulpq->lobby, pos) {
398 cevent = (struct sctp_ulpevent *)pos->cb;
399
400 if (cevent->stream > event->stream) {
401 loc = pos;
402 break;
403 }
404 if (cevent->stream == event->stream &&
405 MID_lt(event->mid, cevent->mid)) {
406 loc = pos;
407 break;
408 }
409 }
410
411 if (!loc)
412 __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
413 else
414 __skb_queue_before(&ulpq->lobby, loc, sctp_event2skb(event));
415 }
416
417 static void sctp_intl_retrieve_ordered(struct sctp_ulpq *ulpq,
418 struct sctp_ulpevent *event)
419 {
420 struct sk_buff_head *event_list;
421 struct sctp_stream *stream;
422 struct sk_buff *pos, *tmp;
423 __u16 sid = event->stream;
424
425 stream = &ulpq->asoc->stream;
426 event_list = (struct sk_buff_head *)sctp_event2skb(event)->prev;
427
428 sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
429 struct sctp_ulpevent *cevent = (struct sctp_ulpevent *)pos->cb;
430
431 if (cevent->stream > sid)
432 break;
433
434 if (cevent->stream < sid)
435 continue;
436
437 if (cevent->mid != sctp_mid_peek(stream, in, sid))
438 break;
439
440 sctp_mid_next(stream, in, sid);
441
442 __skb_unlink(pos, &ulpq->lobby);
443
444 __skb_queue_tail(event_list, pos);
445 }
446 }
447
448 static struct sctp_ulpevent *sctp_intl_order(struct sctp_ulpq *ulpq,
449 struct sctp_ulpevent *event)
450 {
451 struct sctp_stream *stream;
452 __u16 sid;
453
454 stream = &ulpq->asoc->stream;
455 sid = event->stream;
456
457 if (event->mid != sctp_mid_peek(stream, in, sid)) {
458 sctp_intl_store_ordered(ulpq, event);
459 return NULL;
460 }
461
462 sctp_mid_next(stream, in, sid);
463
464 sctp_intl_retrieve_ordered(ulpq, event);
465
466 return event;
467 }
468
469 static int sctp_enqueue_event(struct sctp_ulpq *ulpq,
470 struct sk_buff_head *skb_list)
471 {
472 struct sock *sk = ulpq->asoc->base.sk;
473 struct sctp_sock *sp = sctp_sk(sk);
474 struct sctp_ulpevent *event;
475 struct sk_buff *skb;
476
477 skb = __skb_peek(skb_list);
478 event = sctp_skb2event(skb);
479
480 if (sk->sk_shutdown & RCV_SHUTDOWN &&
481 (sk->sk_shutdown & SEND_SHUTDOWN ||
482 !sctp_ulpevent_is_notification(event)))
483 goto out_free;
484
485 if (!sctp_ulpevent_is_notification(event)) {
486 sk_mark_napi_id(sk, skb);
487 sk_incoming_cpu_update(sk);
488 }
489
490 if (!sctp_ulpevent_is_enabled(event, ulpq->asoc->subscribe))
491 goto out_free;
492
493 skb_queue_splice_tail_init(skb_list,
494 &sk->sk_receive_queue);
495
496 if (!sp->data_ready_signalled) {
497 sp->data_ready_signalled = 1;
498 sk->sk_data_ready(sk);
499 }
500
501 return 1;
502
503 out_free:
504 sctp_queue_purge_ulpevents(skb_list);
505
506 return 0;
507 }
508
509 static void sctp_intl_store_reasm_uo(struct sctp_ulpq *ulpq,
510 struct sctp_ulpevent *event)
511 {
512 struct sctp_ulpevent *cevent;
513 struct sk_buff *pos;
514
515 pos = skb_peek_tail(&ulpq->reasm_uo);
516 if (!pos) {
517 __skb_queue_tail(&ulpq->reasm_uo, sctp_event2skb(event));
518 return;
519 }
520
521 cevent = sctp_skb2event(pos);
522
523 if (event->stream == cevent->stream &&
524 event->mid == cevent->mid &&
525 (cevent->msg_flags & SCTP_DATA_FIRST_FRAG ||
526 (!(event->msg_flags & SCTP_DATA_FIRST_FRAG) &&
527 event->fsn > cevent->fsn))) {
528 __skb_queue_tail(&ulpq->reasm_uo, sctp_event2skb(event));
529 return;
530 }
531
532 if ((event->stream == cevent->stream &&
533 MID_lt(cevent->mid, event->mid)) ||
534 event->stream > cevent->stream) {
535 __skb_queue_tail(&ulpq->reasm_uo, sctp_event2skb(event));
536 return;
537 }
538
539 skb_queue_walk(&ulpq->reasm_uo, pos) {
540 cevent = sctp_skb2event(pos);
541
542 if (event->stream < cevent->stream ||
543 (event->stream == cevent->stream &&
544 MID_lt(event->mid, cevent->mid)))
545 break;
546
547 if (event->stream == cevent->stream &&
548 event->mid == cevent->mid &&
549 !(cevent->msg_flags & SCTP_DATA_FIRST_FRAG) &&
550 (event->msg_flags & SCTP_DATA_FIRST_FRAG ||
551 event->fsn < cevent->fsn))
552 break;
553 }
554
555 __skb_queue_before(&ulpq->reasm_uo, pos, sctp_event2skb(event));
556 }
557
558 static struct sctp_ulpevent *sctp_intl_retrieve_partial_uo(
559 struct sctp_ulpq *ulpq,
560 struct sctp_ulpevent *event)
561 {
562 struct sk_buff *first_frag = NULL;
563 struct sk_buff *last_frag = NULL;
564 struct sctp_ulpevent *retval;
565 struct sctp_stream_in *sin;
566 struct sk_buff *pos;
567 __u32 next_fsn = 0;
568 int is_last = 0;
569
570 sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
571
572 skb_queue_walk(&ulpq->reasm_uo, pos) {
573 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
574
575 if (cevent->stream < event->stream)
576 continue;
577 if (cevent->stream > event->stream)
578 break;
579
580 if (MID_lt(cevent->mid, sin->mid_uo))
581 continue;
582 if (MID_lt(sin->mid_uo, cevent->mid))
583 break;
584
585 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
586 case SCTP_DATA_FIRST_FRAG:
587 goto out;
588 case SCTP_DATA_MIDDLE_FRAG:
589 if (!first_frag) {
590 if (cevent->fsn == sin->fsn_uo) {
591 first_frag = pos;
592 last_frag = pos;
593 next_fsn = cevent->fsn + 1;
594 }
595 } else if (cevent->fsn == next_fsn) {
596 last_frag = pos;
597 next_fsn++;
598 } else {
599 goto out;
600 }
601 break;
602 case SCTP_DATA_LAST_FRAG:
603 if (!first_frag) {
604 if (cevent->fsn == sin->fsn_uo) {
605 first_frag = pos;
606 last_frag = pos;
607 next_fsn = 0;
608 is_last = 1;
609 }
610 } else if (cevent->fsn == next_fsn) {
611 last_frag = pos;
612 next_fsn = 0;
613 is_last = 1;
614 }
615 goto out;
616 default:
617 goto out;
618 }
619 }
620
621 out:
622 if (!first_frag)
623 return NULL;
624
625 retval = sctp_make_reassembled_event(ulpq->asoc->base.net,
626 &ulpq->reasm_uo, first_frag,
627 last_frag);
628 if (retval) {
629 sin->fsn_uo = next_fsn;
630 if (is_last) {
631 retval->msg_flags |= MSG_EOR;
632 sin->pd_mode_uo = 0;
633 }
634 }
635
636 return retval;
637 }
638
639 static struct sctp_ulpevent *sctp_intl_retrieve_reassembled_uo(
640 struct sctp_ulpq *ulpq,
641 struct sctp_ulpevent *event)
642 {
643 struct sctp_association *asoc = ulpq->asoc;
644 struct sk_buff *pos, *first_frag = NULL;
645 struct sctp_ulpevent *retval = NULL;
646 struct sk_buff *pd_first = NULL;
647 struct sk_buff *pd_last = NULL;
648 struct sctp_stream_in *sin;
649 __u32 next_fsn = 0;
650 __u32 pd_point = 0;
651 __u32 pd_len = 0;
652 __u32 mid = 0;
653
654 sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
655
656 skb_queue_walk(&ulpq->reasm_uo, pos) {
657 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
658
659 if (cevent->stream < event->stream)
660 continue;
661 if (cevent->stream > event->stream)
662 break;
663
664 if (MID_lt(cevent->mid, event->mid))
665 continue;
666 if (MID_lt(event->mid, cevent->mid))
667 break;
668
669 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
670 case SCTP_DATA_FIRST_FRAG:
671 if (!sin->pd_mode_uo) {
672 sin->mid_uo = cevent->mid;
673 pd_first = pos;
674 pd_last = pos;
675 pd_len = pos->len;
676 }
677
678 first_frag = pos;
679 next_fsn = 0;
680 mid = cevent->mid;
681 break;
682
683 case SCTP_DATA_MIDDLE_FRAG:
684 if (first_frag && cevent->mid == mid &&
685 cevent->fsn == next_fsn) {
686 next_fsn++;
687 if (pd_first) {
688 pd_last = pos;
689 pd_len += pos->len;
690 }
691 } else {
692 first_frag = NULL;
693 }
694 break;
695
696 case SCTP_DATA_LAST_FRAG:
697 if (first_frag && cevent->mid == mid &&
698 cevent->fsn == next_fsn)
699 goto found;
700 else
701 first_frag = NULL;
702 break;
703 }
704 }
705
706 if (!pd_first)
707 goto out;
708
709 pd_point = sctp_sk(asoc->base.sk)->pd_point;
710 if (pd_point && pd_point <= pd_len) {
711 retval = sctp_make_reassembled_event(asoc->base.net,
712 &ulpq->reasm_uo,
713 pd_first, pd_last);
714 if (retval) {
715 sin->fsn_uo = next_fsn;
716 sin->pd_mode_uo = 1;
717 }
718 }
719 goto out;
720
721 found:
722 retval = sctp_make_reassembled_event(asoc->base.net, &ulpq->reasm_uo,
723 first_frag, pos);
724 if (retval)
725 retval->msg_flags |= MSG_EOR;
726
727 out:
728 return retval;
729 }
730
731 static struct sctp_ulpevent *sctp_intl_reasm_uo(struct sctp_ulpq *ulpq,
732 struct sctp_ulpevent *event)
733 {
734 struct sctp_ulpevent *retval = NULL;
735 struct sctp_stream_in *sin;
736
737 if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
738 event->msg_flags |= MSG_EOR;
739 return event;
740 }
741
742 sctp_intl_store_reasm_uo(ulpq, event);
743
744 sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
745 if (sin->pd_mode_uo && event->mid == sin->mid_uo &&
746 event->fsn == sin->fsn_uo)
747 retval = sctp_intl_retrieve_partial_uo(ulpq, event);
748
749 if (!retval)
750 retval = sctp_intl_retrieve_reassembled_uo(ulpq, event);
751
752 return retval;
753 }
754
755 static struct sctp_ulpevent *sctp_intl_retrieve_first_uo(struct sctp_ulpq *ulpq)
756 {
757 struct sctp_stream_in *csin, *sin = NULL;
758 struct sk_buff *first_frag = NULL;
759 struct sk_buff *last_frag = NULL;
760 struct sctp_ulpevent *retval;
761 struct sk_buff *pos;
762 __u32 next_fsn = 0;
763 __u16 sid = 0;
764
765 skb_queue_walk(&ulpq->reasm_uo, pos) {
766 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
767
768 csin = sctp_stream_in(&ulpq->asoc->stream, cevent->stream);
769 if (csin->pd_mode_uo)
770 continue;
771
772 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
773 case SCTP_DATA_FIRST_FRAG:
774 if (first_frag)
775 goto out;
776 first_frag = pos;
777 last_frag = pos;
778 next_fsn = 0;
779 sin = csin;
780 sid = cevent->stream;
781 sin->mid_uo = cevent->mid;
782 break;
783 case SCTP_DATA_MIDDLE_FRAG:
784 if (!first_frag)
785 break;
786 if (cevent->stream == sid &&
787 cevent->mid == sin->mid_uo &&
788 cevent->fsn == next_fsn) {
789 next_fsn++;
790 last_frag = pos;
791 } else {
792 goto out;
793 }
794 break;
795 case SCTP_DATA_LAST_FRAG:
796 if (first_frag)
797 goto out;
798 break;
799 default:
800 break;
801 }
802 }
803
804 if (!first_frag)
805 return NULL;
806
807 out:
808 retval = sctp_make_reassembled_event(ulpq->asoc->base.net,
809 &ulpq->reasm_uo, first_frag,
810 last_frag);
811 if (retval) {
812 sin->fsn_uo = next_fsn;
813 sin->pd_mode_uo = 1;
814 }
815
816 return retval;
817 }
818
819 static int sctp_ulpevent_idata(struct sctp_ulpq *ulpq,
820 struct sctp_chunk *chunk, gfp_t gfp)
821 {
822 struct sctp_ulpevent *event;
823 struct sk_buff_head temp;
824 int event_eor = 0;
825
826 event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp);
827 if (!event)
828 return -ENOMEM;
829
830 event->mid = ntohl(chunk->subh.idata_hdr->mid);
831 if (event->msg_flags & SCTP_DATA_FIRST_FRAG)
832 event->ppid = chunk->subh.idata_hdr->ppid;
833 else
834 event->fsn = ntohl(chunk->subh.idata_hdr->fsn);
835
836 if (!(event->msg_flags & SCTP_DATA_UNORDERED)) {
837 event = sctp_intl_reasm(ulpq, event);
838 if (event) {
839 skb_queue_head_init(&temp);
840 __skb_queue_tail(&temp, sctp_event2skb(event));
841
842 if (event->msg_flags & MSG_EOR)
843 event = sctp_intl_order(ulpq, event);
844 }
845 } else {
846 event = sctp_intl_reasm_uo(ulpq, event);
847 if (event) {
848 skb_queue_head_init(&temp);
849 __skb_queue_tail(&temp, sctp_event2skb(event));
850 }
851 }
852
853 if (event) {
854 event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0;
855 sctp_enqueue_event(ulpq, &temp);
856 }
857
858 return event_eor;
859 }
860
861 static struct sctp_ulpevent *sctp_intl_retrieve_first(struct sctp_ulpq *ulpq)
862 {
863 struct sctp_stream_in *csin, *sin = NULL;
864 struct sk_buff *first_frag = NULL;
865 struct sk_buff *last_frag = NULL;
866 struct sctp_ulpevent *retval;
867 struct sk_buff *pos;
868 __u32 next_fsn = 0;
869 __u16 sid = 0;
870
871 skb_queue_walk(&ulpq->reasm, pos) {
872 struct sctp_ulpevent *cevent = sctp_skb2event(pos);
873
874 csin = sctp_stream_in(&ulpq->asoc->stream, cevent->stream);
875 if (csin->pd_mode)
876 continue;
877
878 switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
879 case SCTP_DATA_FIRST_FRAG:
880 if (first_frag)
881 goto out;
882 if (cevent->mid == csin->mid) {
883 first_frag = pos;
884 last_frag = pos;
885 next_fsn = 0;
886 sin = csin;
887 sid = cevent->stream;
888 }
889 break;
890 case SCTP_DATA_MIDDLE_FRAG:
891 if (!first_frag)
892 break;
893 if (cevent->stream == sid &&
894 cevent->mid == sin->mid &&
895 cevent->fsn == next_fsn) {
896 next_fsn++;
897 last_frag = pos;
898 } else {
899 goto out;
900 }
901 break;
902 case SCTP_DATA_LAST_FRAG:
903 if (first_frag)
904 goto out;
905 break;
906 default:
907 break;
908 }
909 }
910
911 if (!first_frag)
912 return NULL;
913
914 out:
915 retval = sctp_make_reassembled_event(ulpq->asoc->base.net,
916 &ulpq->reasm, first_frag,
917 last_frag);
918 if (retval) {
919 sin->fsn = next_fsn;
920 sin->pd_mode = 1;
921 }
922
923 return retval;
924 }
925
926 static void sctp_intl_start_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
927 {
928 struct sctp_ulpevent *event;
929 struct sk_buff_head temp;
930
931 if (!skb_queue_empty(&ulpq->reasm)) {
932 do {
933 event = sctp_intl_retrieve_first(ulpq);
934 if (event) {
935 skb_queue_head_init(&temp);
936 __skb_queue_tail(&temp, sctp_event2skb(event));
937 sctp_enqueue_event(ulpq, &temp);
938 }
939 } while (event);
940 }
941
942 if (!skb_queue_empty(&ulpq->reasm_uo)) {
943 do {
944 event = sctp_intl_retrieve_first_uo(ulpq);
945 if (event) {
946 skb_queue_head_init(&temp);
947 __skb_queue_tail(&temp, sctp_event2skb(event));
948 sctp_enqueue_event(ulpq, &temp);
949 }
950 } while (event);
951 }
952 }
953
954 static void sctp_renege_events(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
955 gfp_t gfp)
956 {
957 struct sctp_association *asoc = ulpq->asoc;
958 __u32 freed = 0;
959 __u16 needed;
960
961 needed = ntohs(chunk->chunk_hdr->length) -
962 sizeof(struct sctp_idata_chunk);
963
964 if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
965 freed = sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed);
966 if (freed < needed)
967 freed += sctp_ulpq_renege_list(ulpq, &ulpq->reasm,
968 needed);
969 if (freed < needed)
970 freed += sctp_ulpq_renege_list(ulpq, &ulpq->reasm_uo,
971 needed);
972 }
973
974 if (freed >= needed && sctp_ulpevent_idata(ulpq, chunk, gfp) <= 0)
975 sctp_intl_start_pd(ulpq, gfp);
976 }
977
978 static void sctp_intl_stream_abort_pd(struct sctp_ulpq *ulpq, __u16 sid,
979 __u32 mid, __u16 flags, gfp_t gfp)
980 {
981 struct sock *sk = ulpq->asoc->base.sk;
982 struct sctp_ulpevent *ev = NULL;
983
984 if (!sctp_ulpevent_type_enabled(ulpq->asoc->subscribe,
985 SCTP_PARTIAL_DELIVERY_EVENT))
986 return;
987
988 ev = sctp_ulpevent_make_pdapi(ulpq->asoc, SCTP_PARTIAL_DELIVERY_ABORTED,
989 sid, mid, flags, gfp);
990 if (ev) {
991 struct sctp_sock *sp = sctp_sk(sk);
992
993 __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
994
995 if (!sp->data_ready_signalled) {
996 sp->data_ready_signalled = 1;
997 sk->sk_data_ready(sk);
998 }
999 }
1000 }
1001
1002 static void sctp_intl_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid)
1003 {
1004 struct sctp_stream *stream = &ulpq->asoc->stream;
1005 struct sctp_ulpevent *cevent, *event = NULL;
1006 struct sk_buff_head *lobby = &ulpq->lobby;
1007 struct sk_buff *pos, *tmp;
1008 struct sk_buff_head temp;
1009 __u16 csid;
1010 __u32 cmid;
1011
1012 skb_queue_head_init(&temp);
1013 sctp_skb_for_each(pos, lobby, tmp) {
1014 cevent = (struct sctp_ulpevent *)pos->cb;
1015 csid = cevent->stream;
1016 cmid = cevent->mid;
1017
1018 if (csid > sid)
1019 break;
1020
1021 if (csid < sid)
1022 continue;
1023
1024 if (!MID_lt(cmid, sctp_mid_peek(stream, in, csid)))
1025 break;
1026
1027 __skb_unlink(pos, lobby);
1028 if (!event)
1029 event = sctp_skb2event(pos);
1030
1031 __skb_queue_tail(&temp, pos);
1032 }
1033
1034 if (!event && pos != (struct sk_buff *)lobby) {
1035 cevent = (struct sctp_ulpevent *)pos->cb;
1036 csid = cevent->stream;
1037 cmid = cevent->mid;
1038
1039 if (csid == sid && cmid == sctp_mid_peek(stream, in, csid)) {
1040 sctp_mid_next(stream, in, csid);
1041 __skb_unlink(pos, lobby);
1042 __skb_queue_tail(&temp, pos);
1043 event = sctp_skb2event(pos);
1044 }
1045 }
1046
1047 if (event) {
1048 sctp_intl_retrieve_ordered(ulpq, event);
1049 sctp_enqueue_event(ulpq, &temp);
1050 }
1051 }
1052
1053 static void sctp_intl_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
1054 {
1055 struct sctp_stream *stream = &ulpq->asoc->stream;
1056 __u16 sid;
1057
1058 for (sid = 0; sid < stream->incnt; sid++) {
1059 struct sctp_stream_in *sin = SCTP_SI(stream, sid);
1060 __u32 mid;
1061
1062 if (sin->pd_mode_uo) {
1063 sin->pd_mode_uo = 0;
1064
1065 mid = sin->mid_uo;
1066 sctp_intl_stream_abort_pd(ulpq, sid, mid, 0x1, gfp);
1067 }
1068
1069 if (sin->pd_mode) {
1070 sin->pd_mode = 0;
1071
1072 mid = sin->mid;
1073 sctp_intl_stream_abort_pd(ulpq, sid, mid, 0, gfp);
1074 sctp_mid_skip(stream, in, sid, mid);
1075
1076 sctp_intl_reap_ordered(ulpq, sid);
1077 }
1078 }
1079
1080 /* intl abort pd happens only when all data needs to be cleaned */
1081 sctp_ulpq_flush(ulpq);
1082 }
1083
1084 static inline int sctp_get_skip_pos(struct sctp_ifwdtsn_skip *skiplist,
1085 int nskips, __be16 stream, __u8 flags)
1086 {
1087 int i;
1088
1089 for (i = 0; i < nskips; i++)
1090 if (skiplist[i].stream == stream &&
1091 skiplist[i].flags == flags)
1092 return i;
1093
1094 return i;
1095 }
1096
1097 #define SCTP_FTSN_U_BIT 0x1
1098 static void sctp_generate_iftsn(struct sctp_outq *q, __u32 ctsn)
1099 {
1100 struct sctp_ifwdtsn_skip ftsn_skip_arr[10];
1101 struct sctp_association *asoc = q->asoc;
1102 struct sctp_chunk *ftsn_chunk = NULL;
1103 struct list_head *lchunk, *temp;
1104 int nskips = 0, skip_pos;
1105 struct sctp_chunk *chunk;
1106 __u32 tsn;
1107
1108 if (!asoc->peer.prsctp_capable)
1109 return;
1110
1111 if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1112 asoc->adv_peer_ack_point = ctsn;
1113
1114 list_for_each_safe(lchunk, temp, &q->abandoned) {
1115 chunk = list_entry(lchunk, struct sctp_chunk, transmitted_list);
1116 tsn = ntohl(chunk->subh.data_hdr->tsn);
1117
1118 if (TSN_lte(tsn, ctsn)) {
1119 list_del_init(lchunk);
1120 sctp_chunk_free(chunk);
1121 } else if (TSN_lte(tsn, asoc->adv_peer_ack_point + 1)) {
1122 __be16 sid = chunk->subh.idata_hdr->stream;
1123 __be32 mid = chunk->subh.idata_hdr->mid;
1124 __u8 flags = 0;
1125
1126 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
1127 flags |= SCTP_FTSN_U_BIT;
1128
1129 asoc->adv_peer_ack_point = tsn;
1130 skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], nskips,
1131 sid, flags);
1132 ftsn_skip_arr[skip_pos].stream = sid;
1133 ftsn_skip_arr[skip_pos].reserved = 0;
1134 ftsn_skip_arr[skip_pos].flags = flags;
1135 ftsn_skip_arr[skip_pos].mid = mid;
1136 if (skip_pos == nskips)
1137 nskips++;
1138 if (nskips == 10)
1139 break;
1140 } else {
1141 break;
1142 }
1143 }
1144
1145 if (asoc->adv_peer_ack_point > ctsn)
1146 ftsn_chunk = sctp_make_ifwdtsn(asoc, asoc->adv_peer_ack_point,
1147 nskips, &ftsn_skip_arr[0]);
1148
1149 if (ftsn_chunk) {
1150 list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
1151 SCTP_INC_STATS(asoc->base.net, SCTP_MIB_OUTCTRLCHUNKS);
1152 }
1153 }
1154
1155 #define _sctp_walk_ifwdtsn(pos, chunk, end) \
1156 for (pos = (void *)(chunk->subh.ifwdtsn_hdr + 1); \
1157 (void *)pos <= (void *)(chunk->subh.ifwdtsn_hdr + 1) + (end) - \
1158 sizeof(struct sctp_ifwdtsn_skip); pos++)
1159
1160 #define sctp_walk_ifwdtsn(pos, ch) \
1161 _sctp_walk_ifwdtsn((pos), (ch), ntohs((ch)->chunk_hdr->length) - \
1162 sizeof(struct sctp_ifwdtsn_chunk))
1163
1164 static bool sctp_validate_fwdtsn(struct sctp_chunk *chunk)
1165 {
1166 struct sctp_fwdtsn_skip *skip;
1167 __u16 incnt;
1168
1169 if (chunk->chunk_hdr->type != SCTP_CID_FWD_TSN)
1170 return false;
1171
1172 incnt = chunk->asoc->stream.incnt;
1173 sctp_walk_fwdtsn(skip, chunk)
1174 if (ntohs(skip->stream) >= incnt)
1175 return false;
1176
1177 return true;
1178 }
1179
1180 static bool sctp_validate_iftsn(struct sctp_chunk *chunk)
1181 {
1182 struct sctp_ifwdtsn_skip *skip;
1183 __u16 incnt;
1184
1185 if (chunk->chunk_hdr->type != SCTP_CID_I_FWD_TSN)
1186 return false;
1187
1188 incnt = chunk->asoc->stream.incnt;
1189 sctp_walk_ifwdtsn(skip, chunk)
1190 if (ntohs(skip->stream) >= incnt)
1191 return false;
1192
1193 return true;
1194 }
1195
1196 static void sctp_report_fwdtsn(struct sctp_ulpq *ulpq, __u32 ftsn)
1197 {
1198 /* Move the Cumulattive TSN Ack ahead. */
1199 sctp_tsnmap_skip(&ulpq->asoc->peer.tsn_map, ftsn);
1200 /* purge the fragmentation queue */
1201 sctp_ulpq_reasm_flushtsn(ulpq, ftsn);
1202 /* Abort any in progress partial delivery. */
1203 sctp_ulpq_abort_pd(ulpq, GFP_ATOMIC);
1204 }
1205
1206 static void sctp_intl_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 ftsn)
1207 {
1208 struct sk_buff *pos, *tmp;
1209
1210 skb_queue_walk_safe(&ulpq->reasm, pos, tmp) {
1211 struct sctp_ulpevent *event = sctp_skb2event(pos);
1212 __u32 tsn = event->tsn;
1213
1214 if (TSN_lte(tsn, ftsn)) {
1215 __skb_unlink(pos, &ulpq->reasm);
1216 sctp_ulpevent_free(event);
1217 }
1218 }
1219
1220 skb_queue_walk_safe(&ulpq->reasm_uo, pos, tmp) {
1221 struct sctp_ulpevent *event = sctp_skb2event(pos);
1222 __u32 tsn = event->tsn;
1223
1224 if (TSN_lte(tsn, ftsn)) {
1225 __skb_unlink(pos, &ulpq->reasm_uo);
1226 sctp_ulpevent_free(event);
1227 }
1228 }
1229 }
1230
1231 static void sctp_report_iftsn(struct sctp_ulpq *ulpq, __u32 ftsn)
1232 {
1233 /* Move the Cumulattive TSN Ack ahead. */
1234 sctp_tsnmap_skip(&ulpq->asoc->peer.tsn_map, ftsn);
1235 /* purge the fragmentation queue */
1236 sctp_intl_reasm_flushtsn(ulpq, ftsn);
1237 /* abort only when it's for all data */
1238 if (ftsn == sctp_tsnmap_get_max_tsn_seen(&ulpq->asoc->peer.tsn_map))
1239 sctp_intl_abort_pd(ulpq, GFP_ATOMIC);
1240 }
1241
1242 static void sctp_handle_fwdtsn(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk)
1243 {
1244 struct sctp_fwdtsn_skip *skip;
1245
1246 /* Walk through all the skipped SSNs */
1247 sctp_walk_fwdtsn(skip, chunk)
1248 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
1249 }
1250
1251 static void sctp_intl_skip(struct sctp_ulpq *ulpq, __u16 sid, __u32 mid,
1252 __u8 flags)
1253 {
1254 struct sctp_stream_in *sin = sctp_stream_in(&ulpq->asoc->stream, sid);
1255 struct sctp_stream *stream = &ulpq->asoc->stream;
1256
1257 if (flags & SCTP_FTSN_U_BIT) {
1258 if (sin->pd_mode_uo && MID_lt(sin->mid_uo, mid)) {
1259 sin->pd_mode_uo = 0;
1260 sctp_intl_stream_abort_pd(ulpq, sid, mid, 0x1,
1261 GFP_ATOMIC);
1262 }
1263 return;
1264 }
1265
1266 if (MID_lt(mid, sctp_mid_peek(stream, in, sid)))
1267 return;
1268
1269 if (sin->pd_mode) {
1270 sin->pd_mode = 0;
1271 sctp_intl_stream_abort_pd(ulpq, sid, mid, 0x0, GFP_ATOMIC);
1272 }
1273
1274 sctp_mid_skip(stream, in, sid, mid);
1275
1276 sctp_intl_reap_ordered(ulpq, sid);
1277 }
1278
1279 static void sctp_handle_iftsn(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk)
1280 {
1281 struct sctp_ifwdtsn_skip *skip;
1282
1283 /* Walk through all the skipped MIDs and abort stream pd if possible */
1284 sctp_walk_ifwdtsn(skip, chunk)
1285 sctp_intl_skip(ulpq, ntohs(skip->stream),
1286 ntohl(skip->mid), skip->flags);
1287 }
1288
1289 static int do_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event)
1290 {
1291 struct sk_buff_head temp;
1292
1293 skb_queue_head_init(&temp);
1294 __skb_queue_tail(&temp, sctp_event2skb(event));
1295 return sctp_ulpq_tail_event(ulpq, &temp);
1296 }
1297
1298 static struct sctp_stream_interleave sctp_stream_interleave_0 = {
1299 .data_chunk_len = sizeof(struct sctp_data_chunk),
1300 .ftsn_chunk_len = sizeof(struct sctp_fwdtsn_chunk),
1301 /* DATA process functions */
1302 .make_datafrag = sctp_make_datafrag_empty,
1303 .assign_number = sctp_chunk_assign_ssn,
1304 .validate_data = sctp_validate_data,
1305 .ulpevent_data = sctp_ulpq_tail_data,
1306 .enqueue_event = do_ulpq_tail_event,
1307 .renege_events = sctp_ulpq_renege,
1308 .start_pd = sctp_ulpq_partial_delivery,
1309 .abort_pd = sctp_ulpq_abort_pd,
1310 /* FORWARD-TSN process functions */
1311 .generate_ftsn = sctp_generate_fwdtsn,
1312 .validate_ftsn = sctp_validate_fwdtsn,
1313 .report_ftsn = sctp_report_fwdtsn,
1314 .handle_ftsn = sctp_handle_fwdtsn,
1315 };
1316
1317 static int do_sctp_enqueue_event(struct sctp_ulpq *ulpq,
1318 struct sctp_ulpevent *event)
1319 {
1320 struct sk_buff_head temp;
1321
1322 skb_queue_head_init(&temp);
1323 __skb_queue_tail(&temp, sctp_event2skb(event));
1324 return sctp_enqueue_event(ulpq, &temp);
1325 }
1326
1327 static struct sctp_stream_interleave sctp_stream_interleave_1 = {
1328 .data_chunk_len = sizeof(struct sctp_idata_chunk),
1329 .ftsn_chunk_len = sizeof(struct sctp_ifwdtsn_chunk),
1330 /* I-DATA process functions */
1331 .make_datafrag = sctp_make_idatafrag_empty,
1332 .assign_number = sctp_chunk_assign_mid,
1333 .validate_data = sctp_validate_idata,
1334 .ulpevent_data = sctp_ulpevent_idata,
1335 .enqueue_event = do_sctp_enqueue_event,
1336 .renege_events = sctp_renege_events,
1337 .start_pd = sctp_intl_start_pd,
1338 .abort_pd = sctp_intl_abort_pd,
1339 /* I-FORWARD-TSN process functions */
1340 .generate_ftsn = sctp_generate_iftsn,
1341 .validate_ftsn = sctp_validate_iftsn,
1342 .report_ftsn = sctp_report_iftsn,
1343 .handle_ftsn = sctp_handle_iftsn,
1344 };
1345
1346 void sctp_stream_interleave_init(struct sctp_stream *stream)
1347 {
1348 struct sctp_association *asoc;
1349
1350 asoc = container_of(stream, struct sctp_association, stream);
1351 stream->si = asoc->peer.intl_capable ? &sctp_stream_interleave_1
1352 : &sctp_stream_interleave_0;
1353 }
1354
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