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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 
sctp_make_idatafrag_empty(const struct sctp_association * asoc,const struct sctp_sndrcvinfo * sinfo,int len,__u8 flags,gfp_t gfp)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 
sctp_chunk_assign_mid(struct sctp_chunk * chunk)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 
sctp_validate_data(struct sctp_chunk * chunk)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 
sctp_validate_idata(struct sctp_chunk * chunk)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 
sctp_intl_store_reasm(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)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 
sctp_intl_retrieve_partial(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)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(sock_net(ulpq->asoc->base.sk),
245 					     &ulpq->reasm, first_frag,
246 					     last_frag);
247 	if (retval) {
248 		sin->fsn = next_fsn;
249 		if (is_last) {
250 			retval->msg_flags |= MSG_EOR;
251 			sin->pd_mode = 0;
252 		}
253 	}
254 
255 	return retval;
256 }
257 
sctp_intl_retrieve_reassembled(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)258 static struct sctp_ulpevent *sctp_intl_retrieve_reassembled(
259 						struct sctp_ulpq *ulpq,
260 						struct sctp_ulpevent *event)
261 {
262 	struct sctp_association *asoc = ulpq->asoc;
263 	struct sk_buff *pos, *first_frag = NULL;
264 	struct sctp_ulpevent *retval = NULL;
265 	struct sk_buff *pd_first = NULL;
266 	struct sk_buff *pd_last = NULL;
267 	struct sctp_stream_in *sin;
268 	__u32 next_fsn = 0;
269 	__u32 pd_point = 0;
270 	__u32 pd_len = 0;
271 	__u32 mid = 0;
272 
273 	sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
274 
275 	skb_queue_walk(&ulpq->reasm, pos) {
276 		struct sctp_ulpevent *cevent = sctp_skb2event(pos);
277 
278 		if (cevent->stream < event->stream)
279 			continue;
280 		if (cevent->stream > event->stream)
281 			break;
282 
283 		if (MID_lt(cevent->mid, event->mid))
284 			continue;
285 		if (MID_lt(event->mid, cevent->mid))
286 			break;
287 
288 		switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
289 		case SCTP_DATA_FIRST_FRAG:
290 			if (cevent->mid == sin->mid) {
291 				pd_first = pos;
292 				pd_last = pos;
293 				pd_len = pos->len;
294 			}
295 
296 			first_frag = pos;
297 			next_fsn = 0;
298 			mid = cevent->mid;
299 			break;
300 
301 		case SCTP_DATA_MIDDLE_FRAG:
302 			if (first_frag && cevent->mid == mid &&
303 			    cevent->fsn == next_fsn) {
304 				next_fsn++;
305 				if (pd_first) {
306 					pd_last = pos;
307 					pd_len += pos->len;
308 				}
309 			} else {
310 				first_frag = NULL;
311 			}
312 			break;
313 
314 		case SCTP_DATA_LAST_FRAG:
315 			if (first_frag && cevent->mid == mid &&
316 			    cevent->fsn == next_fsn)
317 				goto found;
318 			else
319 				first_frag = NULL;
320 			break;
321 		}
322 	}
323 
324 	if (!pd_first)
325 		goto out;
326 
327 	pd_point = sctp_sk(asoc->base.sk)->pd_point;
328 	if (pd_point && pd_point <= pd_len) {
329 		retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
330 						     &ulpq->reasm,
331 						     pd_first, pd_last);
332 		if (retval) {
333 			sin->fsn = next_fsn;
334 			sin->pd_mode = 1;
335 		}
336 	}
337 	goto out;
338 
339 found:
340 	retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
341 					     &ulpq->reasm,
342 					     first_frag, pos);
343 	if (retval)
344 		retval->msg_flags |= MSG_EOR;
345 
346 out:
347 	return retval;
348 }
349 
sctp_intl_reasm(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)350 static struct sctp_ulpevent *sctp_intl_reasm(struct sctp_ulpq *ulpq,
351 					     struct sctp_ulpevent *event)
352 {
353 	struct sctp_ulpevent *retval = NULL;
354 	struct sctp_stream_in *sin;
355 
356 	if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
357 		event->msg_flags |= MSG_EOR;
358 		return event;
359 	}
360 
361 	sctp_intl_store_reasm(ulpq, event);
362 
363 	sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
364 	if (sin->pd_mode && event->mid == sin->mid &&
365 	    event->fsn == sin->fsn)
366 		retval = sctp_intl_retrieve_partial(ulpq, event);
367 
368 	if (!retval)
369 		retval = sctp_intl_retrieve_reassembled(ulpq, event);
370 
371 	return retval;
372 }
373 
sctp_intl_store_ordered(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)374 static void sctp_intl_store_ordered(struct sctp_ulpq *ulpq,
375 				    struct sctp_ulpevent *event)
376 {
377 	struct sctp_ulpevent *cevent;
378 	struct sk_buff *pos, *loc;
379 
380 	pos = skb_peek_tail(&ulpq->lobby);
381 	if (!pos) {
382 		__skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
383 		return;
384 	}
385 
386 	cevent = (struct sctp_ulpevent *)pos->cb;
387 	if (event->stream == cevent->stream &&
388 	    MID_lt(cevent->mid, event->mid)) {
389 		__skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
390 		return;
391 	}
392 
393 	if (event->stream > cevent->stream) {
394 		__skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
395 		return;
396 	}
397 
398 	loc = NULL;
399 	skb_queue_walk(&ulpq->lobby, pos) {
400 		cevent = (struct sctp_ulpevent *)pos->cb;
401 
402 		if (cevent->stream > event->stream) {
403 			loc = pos;
404 			break;
405 		}
406 		if (cevent->stream == event->stream &&
407 		    MID_lt(event->mid, cevent->mid)) {
408 			loc = pos;
409 			break;
410 		}
411 	}
412 
413 	if (!loc)
414 		__skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
415 	else
416 		__skb_queue_before(&ulpq->lobby, loc, sctp_event2skb(event));
417 }
418 
sctp_intl_retrieve_ordered(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)419 static void sctp_intl_retrieve_ordered(struct sctp_ulpq *ulpq,
420 				       struct sctp_ulpevent *event)
421 {
422 	struct sk_buff_head *event_list;
423 	struct sctp_stream *stream;
424 	struct sk_buff *pos, *tmp;
425 	__u16 sid = event->stream;
426 
427 	stream  = &ulpq->asoc->stream;
428 	event_list = (struct sk_buff_head *)sctp_event2skb(event)->prev;
429 
430 	sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
431 		struct sctp_ulpevent *cevent = (struct sctp_ulpevent *)pos->cb;
432 
433 		if (cevent->stream > sid)
434 			break;
435 
436 		if (cevent->stream < sid)
437 			continue;
438 
439 		if (cevent->mid != sctp_mid_peek(stream, in, sid))
440 			break;
441 
442 		sctp_mid_next(stream, in, sid);
443 
444 		__skb_unlink(pos, &ulpq->lobby);
445 
446 		__skb_queue_tail(event_list, pos);
447 	}
448 }
449 
sctp_intl_order(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)450 static struct sctp_ulpevent *sctp_intl_order(struct sctp_ulpq *ulpq,
451 					     struct sctp_ulpevent *event)
452 {
453 	struct sctp_stream *stream;
454 	__u16 sid;
455 
456 	stream  = &ulpq->asoc->stream;
457 	sid = event->stream;
458 
459 	if (event->mid != sctp_mid_peek(stream, in, sid)) {
460 		sctp_intl_store_ordered(ulpq, event);
461 		return NULL;
462 	}
463 
464 	sctp_mid_next(stream, in, sid);
465 
466 	sctp_intl_retrieve_ordered(ulpq, event);
467 
468 	return event;
469 }
470 
sctp_enqueue_event(struct sctp_ulpq * ulpq,struct sk_buff_head * skb_list)471 static int sctp_enqueue_event(struct sctp_ulpq *ulpq,
472 			      struct sk_buff_head *skb_list)
473 {
474 	struct sock *sk = ulpq->asoc->base.sk;
475 	struct sctp_sock *sp = sctp_sk(sk);
476 	struct sctp_ulpevent *event;
477 	struct sk_buff *skb;
478 
479 	skb = __skb_peek(skb_list);
480 	event = sctp_skb2event(skb);
481 
482 	if (sk->sk_shutdown & RCV_SHUTDOWN &&
483 	    (sk->sk_shutdown & SEND_SHUTDOWN ||
484 	     !sctp_ulpevent_is_notification(event)))
485 		goto out_free;
486 
487 	if (!sctp_ulpevent_is_notification(event)) {
488 		sk_mark_napi_id(sk, skb);
489 		sk_incoming_cpu_update(sk);
490 	}
491 
492 	if (!sctp_ulpevent_is_enabled(event, ulpq->asoc->subscribe))
493 		goto out_free;
494 
495 	if (skb_list)
496 		skb_queue_splice_tail_init(skb_list,
497 					   &sk->sk_receive_queue);
498 	else
499 		__skb_queue_tail(&sk->sk_receive_queue, skb);
500 
501 	if (!sp->data_ready_signalled) {
502 		sp->data_ready_signalled = 1;
503 		sk->sk_data_ready(sk);
504 	}
505 
506 	return 1;
507 
508 out_free:
509 	if (skb_list)
510 		sctp_queue_purge_ulpevents(skb_list);
511 	else
512 		sctp_ulpevent_free(event);
513 
514 	return 0;
515 }
516 
sctp_intl_store_reasm_uo(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)517 static void sctp_intl_store_reasm_uo(struct sctp_ulpq *ulpq,
518 				     struct sctp_ulpevent *event)
519 {
520 	struct sctp_ulpevent *cevent;
521 	struct sk_buff *pos;
522 
523 	pos = skb_peek_tail(&ulpq->reasm_uo);
524 	if (!pos) {
525 		__skb_queue_tail(&ulpq->reasm_uo, sctp_event2skb(event));
526 		return;
527 	}
528 
529 	cevent = sctp_skb2event(pos);
530 
531 	if (event->stream == cevent->stream &&
532 	    event->mid == cevent->mid &&
533 	    (cevent->msg_flags & SCTP_DATA_FIRST_FRAG ||
534 	     (!(event->msg_flags & SCTP_DATA_FIRST_FRAG) &&
535 	      event->fsn > cevent->fsn))) {
536 		__skb_queue_tail(&ulpq->reasm_uo, sctp_event2skb(event));
537 		return;
538 	}
539 
540 	if ((event->stream == cevent->stream &&
541 	     MID_lt(cevent->mid, event->mid)) ||
542 	    event->stream > cevent->stream) {
543 		__skb_queue_tail(&ulpq->reasm_uo, sctp_event2skb(event));
544 		return;
545 	}
546 
547 	skb_queue_walk(&ulpq->reasm_uo, pos) {
548 		cevent = sctp_skb2event(pos);
549 
550 		if (event->stream < cevent->stream ||
551 		    (event->stream == cevent->stream &&
552 		     MID_lt(event->mid, cevent->mid)))
553 			break;
554 
555 		if (event->stream == cevent->stream &&
556 		    event->mid == cevent->mid &&
557 		    !(cevent->msg_flags & SCTP_DATA_FIRST_FRAG) &&
558 		    (event->msg_flags & SCTP_DATA_FIRST_FRAG ||
559 		     event->fsn < cevent->fsn))
560 			break;
561 	}
562 
563 	__skb_queue_before(&ulpq->reasm_uo, pos, sctp_event2skb(event));
564 }
565 
sctp_intl_retrieve_partial_uo(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)566 static struct sctp_ulpevent *sctp_intl_retrieve_partial_uo(
567 						struct sctp_ulpq *ulpq,
568 						struct sctp_ulpevent *event)
569 {
570 	struct sk_buff *first_frag = NULL;
571 	struct sk_buff *last_frag = NULL;
572 	struct sctp_ulpevent *retval;
573 	struct sctp_stream_in *sin;
574 	struct sk_buff *pos;
575 	__u32 next_fsn = 0;
576 	int is_last = 0;
577 
578 	sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
579 
580 	skb_queue_walk(&ulpq->reasm_uo, pos) {
581 		struct sctp_ulpevent *cevent = sctp_skb2event(pos);
582 
583 		if (cevent->stream < event->stream)
584 			continue;
585 		if (cevent->stream > event->stream)
586 			break;
587 
588 		if (MID_lt(cevent->mid, sin->mid_uo))
589 			continue;
590 		if (MID_lt(sin->mid_uo, cevent->mid))
591 			break;
592 
593 		switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
594 		case SCTP_DATA_FIRST_FRAG:
595 			goto out;
596 		case SCTP_DATA_MIDDLE_FRAG:
597 			if (!first_frag) {
598 				if (cevent->fsn == sin->fsn_uo) {
599 					first_frag = pos;
600 					last_frag = pos;
601 					next_fsn = cevent->fsn + 1;
602 				}
603 			} else if (cevent->fsn == next_fsn) {
604 				last_frag = pos;
605 				next_fsn++;
606 			} else {
607 				goto out;
608 			}
609 			break;
610 		case SCTP_DATA_LAST_FRAG:
611 			if (!first_frag) {
612 				if (cevent->fsn == sin->fsn_uo) {
613 					first_frag = pos;
614 					last_frag = pos;
615 					next_fsn = 0;
616 					is_last = 1;
617 				}
618 			} else if (cevent->fsn == next_fsn) {
619 				last_frag = pos;
620 				next_fsn = 0;
621 				is_last = 1;
622 			}
623 			goto out;
624 		default:
625 			goto out;
626 		}
627 	}
628 
629 out:
630 	if (!first_frag)
631 		return NULL;
632 
633 	retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
634 					     &ulpq->reasm_uo, first_frag,
635 					     last_frag);
636 	if (retval) {
637 		sin->fsn_uo = next_fsn;
638 		if (is_last) {
639 			retval->msg_flags |= MSG_EOR;
640 			sin->pd_mode_uo = 0;
641 		}
642 	}
643 
644 	return retval;
645 }
646 
sctp_intl_retrieve_reassembled_uo(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)647 static struct sctp_ulpevent *sctp_intl_retrieve_reassembled_uo(
648 						struct sctp_ulpq *ulpq,
649 						struct sctp_ulpevent *event)
650 {
651 	struct sctp_association *asoc = ulpq->asoc;
652 	struct sk_buff *pos, *first_frag = NULL;
653 	struct sctp_ulpevent *retval = NULL;
654 	struct sk_buff *pd_first = NULL;
655 	struct sk_buff *pd_last = NULL;
656 	struct sctp_stream_in *sin;
657 	__u32 next_fsn = 0;
658 	__u32 pd_point = 0;
659 	__u32 pd_len = 0;
660 	__u32 mid = 0;
661 
662 	sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
663 
664 	skb_queue_walk(&ulpq->reasm_uo, pos) {
665 		struct sctp_ulpevent *cevent = sctp_skb2event(pos);
666 
667 		if (cevent->stream < event->stream)
668 			continue;
669 		if (cevent->stream > event->stream)
670 			break;
671 
672 		if (MID_lt(cevent->mid, event->mid))
673 			continue;
674 		if (MID_lt(event->mid, cevent->mid))
675 			break;
676 
677 		switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
678 		case SCTP_DATA_FIRST_FRAG:
679 			if (!sin->pd_mode_uo) {
680 				sin->mid_uo = cevent->mid;
681 				pd_first = pos;
682 				pd_last = pos;
683 				pd_len = pos->len;
684 			}
685 
686 			first_frag = pos;
687 			next_fsn = 0;
688 			mid = cevent->mid;
689 			break;
690 
691 		case SCTP_DATA_MIDDLE_FRAG:
692 			if (first_frag && cevent->mid == mid &&
693 			    cevent->fsn == next_fsn) {
694 				next_fsn++;
695 				if (pd_first) {
696 					pd_last = pos;
697 					pd_len += pos->len;
698 				}
699 			} else {
700 				first_frag = NULL;
701 			}
702 			break;
703 
704 		case SCTP_DATA_LAST_FRAG:
705 			if (first_frag && cevent->mid == mid &&
706 			    cevent->fsn == next_fsn)
707 				goto found;
708 			else
709 				first_frag = NULL;
710 			break;
711 		}
712 	}
713 
714 	if (!pd_first)
715 		goto out;
716 
717 	pd_point = sctp_sk(asoc->base.sk)->pd_point;
718 	if (pd_point && pd_point <= pd_len) {
719 		retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
720 						     &ulpq->reasm_uo,
721 						     pd_first, pd_last);
722 		if (retval) {
723 			sin->fsn_uo = next_fsn;
724 			sin->pd_mode_uo = 1;
725 		}
726 	}
727 	goto out;
728 
729 found:
730 	retval = sctp_make_reassembled_event(sock_net(asoc->base.sk),
731 					     &ulpq->reasm_uo,
732 					     first_frag, pos);
733 	if (retval)
734 		retval->msg_flags |= MSG_EOR;
735 
736 out:
737 	return retval;
738 }
739 
sctp_intl_reasm_uo(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)740 static struct sctp_ulpevent *sctp_intl_reasm_uo(struct sctp_ulpq *ulpq,
741 						struct sctp_ulpevent *event)
742 {
743 	struct sctp_ulpevent *retval = NULL;
744 	struct sctp_stream_in *sin;
745 
746 	if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
747 		event->msg_flags |= MSG_EOR;
748 		return event;
749 	}
750 
751 	sctp_intl_store_reasm_uo(ulpq, event);
752 
753 	sin = sctp_stream_in(&ulpq->asoc->stream, event->stream);
754 	if (sin->pd_mode_uo && event->mid == sin->mid_uo &&
755 	    event->fsn == sin->fsn_uo)
756 		retval = sctp_intl_retrieve_partial_uo(ulpq, event);
757 
758 	if (!retval)
759 		retval = sctp_intl_retrieve_reassembled_uo(ulpq, event);
760 
761 	return retval;
762 }
763 
sctp_intl_retrieve_first_uo(struct sctp_ulpq * ulpq)764 static struct sctp_ulpevent *sctp_intl_retrieve_first_uo(struct sctp_ulpq *ulpq)
765 {
766 	struct sctp_stream_in *csin, *sin = NULL;
767 	struct sk_buff *first_frag = NULL;
768 	struct sk_buff *last_frag = NULL;
769 	struct sctp_ulpevent *retval;
770 	struct sk_buff *pos;
771 	__u32 next_fsn = 0;
772 	__u16 sid = 0;
773 
774 	skb_queue_walk(&ulpq->reasm_uo, pos) {
775 		struct sctp_ulpevent *cevent = sctp_skb2event(pos);
776 
777 		csin = sctp_stream_in(&ulpq->asoc->stream, cevent->stream);
778 		if (csin->pd_mode_uo)
779 			continue;
780 
781 		switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
782 		case SCTP_DATA_FIRST_FRAG:
783 			if (first_frag)
784 				goto out;
785 			first_frag = pos;
786 			last_frag = pos;
787 			next_fsn = 0;
788 			sin = csin;
789 			sid = cevent->stream;
790 			sin->mid_uo = cevent->mid;
791 			break;
792 		case SCTP_DATA_MIDDLE_FRAG:
793 			if (!first_frag)
794 				break;
795 			if (cevent->stream == sid &&
796 			    cevent->mid == sin->mid_uo &&
797 			    cevent->fsn == next_fsn) {
798 				next_fsn++;
799 				last_frag = pos;
800 			} else {
801 				goto out;
802 			}
803 			break;
804 		case SCTP_DATA_LAST_FRAG:
805 			if (first_frag)
806 				goto out;
807 			break;
808 		default:
809 			break;
810 		}
811 	}
812 
813 	if (!first_frag)
814 		return NULL;
815 
816 out:
817 	retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
818 					     &ulpq->reasm_uo, first_frag,
819 					     last_frag);
820 	if (retval) {
821 		sin->fsn_uo = next_fsn;
822 		sin->pd_mode_uo = 1;
823 	}
824 
825 	return retval;
826 }
827 
sctp_ulpevent_idata(struct sctp_ulpq * ulpq,struct sctp_chunk * chunk,gfp_t gfp)828 static int sctp_ulpevent_idata(struct sctp_ulpq *ulpq,
829 			       struct sctp_chunk *chunk, gfp_t gfp)
830 {
831 	struct sctp_ulpevent *event;
832 	struct sk_buff_head temp;
833 	int event_eor = 0;
834 
835 	event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp);
836 	if (!event)
837 		return -ENOMEM;
838 
839 	event->mid = ntohl(chunk->subh.idata_hdr->mid);
840 	if (event->msg_flags & SCTP_DATA_FIRST_FRAG)
841 		event->ppid = chunk->subh.idata_hdr->ppid;
842 	else
843 		event->fsn = ntohl(chunk->subh.idata_hdr->fsn);
844 
845 	if (!(event->msg_flags & SCTP_DATA_UNORDERED)) {
846 		event = sctp_intl_reasm(ulpq, event);
847 		if (event) {
848 			skb_queue_head_init(&temp);
849 			__skb_queue_tail(&temp, sctp_event2skb(event));
850 
851 			if (event->msg_flags & MSG_EOR)
852 				event = sctp_intl_order(ulpq, event);
853 		}
854 	} else {
855 		event = sctp_intl_reasm_uo(ulpq, event);
856 		if (event) {
857 			skb_queue_head_init(&temp);
858 			__skb_queue_tail(&temp, sctp_event2skb(event));
859 		}
860 	}
861 
862 	if (event) {
863 		event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0;
864 		sctp_enqueue_event(ulpq, &temp);
865 	}
866 
867 	return event_eor;
868 }
869 
sctp_intl_retrieve_first(struct sctp_ulpq * ulpq)870 static struct sctp_ulpevent *sctp_intl_retrieve_first(struct sctp_ulpq *ulpq)
871 {
872 	struct sctp_stream_in *csin, *sin = NULL;
873 	struct sk_buff *first_frag = NULL;
874 	struct sk_buff *last_frag = NULL;
875 	struct sctp_ulpevent *retval;
876 	struct sk_buff *pos;
877 	__u32 next_fsn = 0;
878 	__u16 sid = 0;
879 
880 	skb_queue_walk(&ulpq->reasm, pos) {
881 		struct sctp_ulpevent *cevent = sctp_skb2event(pos);
882 
883 		csin = sctp_stream_in(&ulpq->asoc->stream, cevent->stream);
884 		if (csin->pd_mode)
885 			continue;
886 
887 		switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
888 		case SCTP_DATA_FIRST_FRAG:
889 			if (first_frag)
890 				goto out;
891 			if (cevent->mid == csin->mid) {
892 				first_frag = pos;
893 				last_frag = pos;
894 				next_fsn = 0;
895 				sin = csin;
896 				sid = cevent->stream;
897 			}
898 			break;
899 		case SCTP_DATA_MIDDLE_FRAG:
900 			if (!first_frag)
901 				break;
902 			if (cevent->stream == sid &&
903 			    cevent->mid == sin->mid &&
904 			    cevent->fsn == next_fsn) {
905 				next_fsn++;
906 				last_frag = pos;
907 			} else {
908 				goto out;
909 			}
910 			break;
911 		case SCTP_DATA_LAST_FRAG:
912 			if (first_frag)
913 				goto out;
914 			break;
915 		default:
916 			break;
917 		}
918 	}
919 
920 	if (!first_frag)
921 		return NULL;
922 
923 out:
924 	retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
925 					     &ulpq->reasm, first_frag,
926 					     last_frag);
927 	if (retval) {
928 		sin->fsn = next_fsn;
929 		sin->pd_mode = 1;
930 	}
931 
932 	return retval;
933 }
934 
sctp_intl_start_pd(struct sctp_ulpq * ulpq,gfp_t gfp)935 static void sctp_intl_start_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
936 {
937 	struct sctp_ulpevent *event;
938 	struct sk_buff_head temp;
939 
940 	if (!skb_queue_empty(&ulpq->reasm)) {
941 		do {
942 			event = sctp_intl_retrieve_first(ulpq);
943 			if (event) {
944 				skb_queue_head_init(&temp);
945 				__skb_queue_tail(&temp, sctp_event2skb(event));
946 				sctp_enqueue_event(ulpq, &temp);
947 			}
948 		} while (event);
949 	}
950 
951 	if (!skb_queue_empty(&ulpq->reasm_uo)) {
952 		do {
953 			event = sctp_intl_retrieve_first_uo(ulpq);
954 			if (event) {
955 				skb_queue_head_init(&temp);
956 				__skb_queue_tail(&temp, sctp_event2skb(event));
957 				sctp_enqueue_event(ulpq, &temp);
958 			}
959 		} while (event);
960 	}
961 }
962 
sctp_renege_events(struct sctp_ulpq * ulpq,struct sctp_chunk * chunk,gfp_t gfp)963 static void sctp_renege_events(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
964 			       gfp_t gfp)
965 {
966 	struct sctp_association *asoc = ulpq->asoc;
967 	__u32 freed = 0;
968 	__u16 needed;
969 
970 	needed = ntohs(chunk->chunk_hdr->length) -
971 		 sizeof(struct sctp_idata_chunk);
972 
973 	if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
974 		freed = sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed);
975 		if (freed < needed)
976 			freed += sctp_ulpq_renege_list(ulpq, &ulpq->reasm,
977 						       needed);
978 		if (freed < needed)
979 			freed += sctp_ulpq_renege_list(ulpq, &ulpq->reasm_uo,
980 						       needed);
981 	}
982 
983 	if (freed >= needed && sctp_ulpevent_idata(ulpq, chunk, gfp) <= 0)
984 		sctp_intl_start_pd(ulpq, gfp);
985 
986 	sk_mem_reclaim(asoc->base.sk);
987 }
988 
sctp_intl_stream_abort_pd(struct sctp_ulpq * ulpq,__u16 sid,__u32 mid,__u16 flags,gfp_t gfp)989 static void sctp_intl_stream_abort_pd(struct sctp_ulpq *ulpq, __u16 sid,
990 				      __u32 mid, __u16 flags, gfp_t gfp)
991 {
992 	struct sock *sk = ulpq->asoc->base.sk;
993 	struct sctp_ulpevent *ev = NULL;
994 
995 	if (!sctp_ulpevent_type_enabled(ulpq->asoc->subscribe,
996 					SCTP_PARTIAL_DELIVERY_EVENT))
997 		return;
998 
999 	ev = sctp_ulpevent_make_pdapi(ulpq->asoc, SCTP_PARTIAL_DELIVERY_ABORTED,
1000 				      sid, mid, flags, gfp);
1001 	if (ev) {
1002 		struct sctp_sock *sp = sctp_sk(sk);
1003 
1004 		__skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
1005 
1006 		if (!sp->data_ready_signalled) {
1007 			sp->data_ready_signalled = 1;
1008 			sk->sk_data_ready(sk);
1009 		}
1010 	}
1011 }
1012 
sctp_intl_reap_ordered(struct sctp_ulpq * ulpq,__u16 sid)1013 static void sctp_intl_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid)
1014 {
1015 	struct sctp_stream *stream = &ulpq->asoc->stream;
1016 	struct sctp_ulpevent *cevent, *event = NULL;
1017 	struct sk_buff_head *lobby = &ulpq->lobby;
1018 	struct sk_buff *pos, *tmp;
1019 	struct sk_buff_head temp;
1020 	__u16 csid;
1021 	__u32 cmid;
1022 
1023 	skb_queue_head_init(&temp);
1024 	sctp_skb_for_each(pos, lobby, tmp) {
1025 		cevent = (struct sctp_ulpevent *)pos->cb;
1026 		csid = cevent->stream;
1027 		cmid = cevent->mid;
1028 
1029 		if (csid > sid)
1030 			break;
1031 
1032 		if (csid < sid)
1033 			continue;
1034 
1035 		if (!MID_lt(cmid, sctp_mid_peek(stream, in, csid)))
1036 			break;
1037 
1038 		__skb_unlink(pos, lobby);
1039 		if (!event)
1040 			event = sctp_skb2event(pos);
1041 
1042 		__skb_queue_tail(&temp, pos);
1043 	}
1044 
1045 	if (!event && pos != (struct sk_buff *)lobby) {
1046 		cevent = (struct sctp_ulpevent *)pos->cb;
1047 		csid = cevent->stream;
1048 		cmid = cevent->mid;
1049 
1050 		if (csid == sid && cmid == sctp_mid_peek(stream, in, csid)) {
1051 			sctp_mid_next(stream, in, csid);
1052 			__skb_unlink(pos, lobby);
1053 			__skb_queue_tail(&temp, pos);
1054 			event = sctp_skb2event(pos);
1055 		}
1056 	}
1057 
1058 	if (event) {
1059 		sctp_intl_retrieve_ordered(ulpq, event);
1060 		sctp_enqueue_event(ulpq, &temp);
1061 	}
1062 }
1063 
sctp_intl_abort_pd(struct sctp_ulpq * ulpq,gfp_t gfp)1064 static void sctp_intl_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
1065 {
1066 	struct sctp_stream *stream = &ulpq->asoc->stream;
1067 	__u16 sid;
1068 
1069 	for (sid = 0; sid < stream->incnt; sid++) {
1070 		struct sctp_stream_in *sin = SCTP_SI(stream, sid);
1071 		__u32 mid;
1072 
1073 		if (sin->pd_mode_uo) {
1074 			sin->pd_mode_uo = 0;
1075 
1076 			mid = sin->mid_uo;
1077 			sctp_intl_stream_abort_pd(ulpq, sid, mid, 0x1, gfp);
1078 		}
1079 
1080 		if (sin->pd_mode) {
1081 			sin->pd_mode = 0;
1082 
1083 			mid = sin->mid;
1084 			sctp_intl_stream_abort_pd(ulpq, sid, mid, 0, gfp);
1085 			sctp_mid_skip(stream, in, sid, mid);
1086 
1087 			sctp_intl_reap_ordered(ulpq, sid);
1088 		}
1089 	}
1090 
1091 	/* intl abort pd happens only when all data needs to be cleaned */
1092 	sctp_ulpq_flush(ulpq);
1093 }
1094 
sctp_get_skip_pos(struct sctp_ifwdtsn_skip * skiplist,int nskips,__be16 stream,__u8 flags)1095 static inline int sctp_get_skip_pos(struct sctp_ifwdtsn_skip *skiplist,
1096 				    int nskips, __be16 stream, __u8 flags)
1097 {
1098 	int i;
1099 
1100 	for (i = 0; i < nskips; i++)
1101 		if (skiplist[i].stream == stream &&
1102 		    skiplist[i].flags == flags)
1103 			return i;
1104 
1105 	return i;
1106 }
1107 
1108 #define SCTP_FTSN_U_BIT	0x1
sctp_generate_iftsn(struct sctp_outq * q,__u32 ctsn)1109 static void sctp_generate_iftsn(struct sctp_outq *q, __u32 ctsn)
1110 {
1111 	struct sctp_ifwdtsn_skip ftsn_skip_arr[10];
1112 	struct sctp_association *asoc = q->asoc;
1113 	struct sctp_chunk *ftsn_chunk = NULL;
1114 	struct list_head *lchunk, *temp;
1115 	int nskips = 0, skip_pos;
1116 	struct sctp_chunk *chunk;
1117 	__u32 tsn;
1118 
1119 	if (!asoc->peer.prsctp_capable)
1120 		return;
1121 
1122 	if (TSN_lt(asoc->adv_peer_ack_point, ctsn))
1123 		asoc->adv_peer_ack_point = ctsn;
1124 
1125 	list_for_each_safe(lchunk, temp, &q->abandoned) {
1126 		chunk = list_entry(lchunk, struct sctp_chunk, transmitted_list);
1127 		tsn = ntohl(chunk->subh.data_hdr->tsn);
1128 
1129 		if (TSN_lte(tsn, ctsn)) {
1130 			list_del_init(lchunk);
1131 			sctp_chunk_free(chunk);
1132 		} else if (TSN_lte(tsn, asoc->adv_peer_ack_point + 1)) {
1133 			__be16 sid = chunk->subh.idata_hdr->stream;
1134 			__be32 mid = chunk->subh.idata_hdr->mid;
1135 			__u8 flags = 0;
1136 
1137 			if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
1138 				flags |= SCTP_FTSN_U_BIT;
1139 
1140 			asoc->adv_peer_ack_point = tsn;
1141 			skip_pos = sctp_get_skip_pos(&ftsn_skip_arr[0], nskips,
1142 						     sid, flags);
1143 			ftsn_skip_arr[skip_pos].stream = sid;
1144 			ftsn_skip_arr[skip_pos].reserved = 0;
1145 			ftsn_skip_arr[skip_pos].flags = flags;
1146 			ftsn_skip_arr[skip_pos].mid = mid;
1147 			if (skip_pos == nskips)
1148 				nskips++;
1149 			if (nskips == 10)
1150 				break;
1151 		} else {
1152 			break;
1153 		}
1154 	}
1155 
1156 	if (asoc->adv_peer_ack_point > ctsn)
1157 		ftsn_chunk = sctp_make_ifwdtsn(asoc, asoc->adv_peer_ack_point,
1158 					       nskips, &ftsn_skip_arr[0]);
1159 
1160 	if (ftsn_chunk) {
1161 		list_add_tail(&ftsn_chunk->list, &q->control_chunk_list);
1162 		SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_OUTCTRLCHUNKS);
1163 	}
1164 }
1165 
1166 #define _sctp_walk_ifwdtsn(pos, chunk, end) \
1167 	for (pos = chunk->subh.ifwdtsn_hdr->skip; \
1168 	     (void *)pos < (void *)chunk->subh.ifwdtsn_hdr->skip + (end); pos++)
1169 
1170 #define sctp_walk_ifwdtsn(pos, ch) \
1171 	_sctp_walk_ifwdtsn((pos), (ch), ntohs((ch)->chunk_hdr->length) - \
1172 					sizeof(struct sctp_ifwdtsn_chunk))
1173 
sctp_validate_fwdtsn(struct sctp_chunk * chunk)1174 static bool sctp_validate_fwdtsn(struct sctp_chunk *chunk)
1175 {
1176 	struct sctp_fwdtsn_skip *skip;
1177 	__u16 incnt;
1178 
1179 	if (chunk->chunk_hdr->type != SCTP_CID_FWD_TSN)
1180 		return false;
1181 
1182 	incnt = chunk->asoc->stream.incnt;
1183 	sctp_walk_fwdtsn(skip, chunk)
1184 		if (ntohs(skip->stream) >= incnt)
1185 			return false;
1186 
1187 	return true;
1188 }
1189 
sctp_validate_iftsn(struct sctp_chunk * chunk)1190 static bool sctp_validate_iftsn(struct sctp_chunk *chunk)
1191 {
1192 	struct sctp_ifwdtsn_skip *skip;
1193 	__u16 incnt;
1194 
1195 	if (chunk->chunk_hdr->type != SCTP_CID_I_FWD_TSN)
1196 		return false;
1197 
1198 	incnt = chunk->asoc->stream.incnt;
1199 	sctp_walk_ifwdtsn(skip, chunk)
1200 		if (ntohs(skip->stream) >= incnt)
1201 			return false;
1202 
1203 	return true;
1204 }
1205 
sctp_report_fwdtsn(struct sctp_ulpq * ulpq,__u32 ftsn)1206 static void sctp_report_fwdtsn(struct sctp_ulpq *ulpq, __u32 ftsn)
1207 {
1208 	/* Move the Cumulattive TSN Ack ahead. */
1209 	sctp_tsnmap_skip(&ulpq->asoc->peer.tsn_map, ftsn);
1210 	/* purge the fragmentation queue */
1211 	sctp_ulpq_reasm_flushtsn(ulpq, ftsn);
1212 	/* Abort any in progress partial delivery. */
1213 	sctp_ulpq_abort_pd(ulpq, GFP_ATOMIC);
1214 }
1215 
sctp_intl_reasm_flushtsn(struct sctp_ulpq * ulpq,__u32 ftsn)1216 static void sctp_intl_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 ftsn)
1217 {
1218 	struct sk_buff *pos, *tmp;
1219 
1220 	skb_queue_walk_safe(&ulpq->reasm, 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);
1226 			sctp_ulpevent_free(event);
1227 		}
1228 	}
1229 
1230 	skb_queue_walk_safe(&ulpq->reasm_uo, pos, tmp) {
1231 		struct sctp_ulpevent *event = sctp_skb2event(pos);
1232 		__u32 tsn = event->tsn;
1233 
1234 		if (TSN_lte(tsn, ftsn)) {
1235 			__skb_unlink(pos, &ulpq->reasm_uo);
1236 			sctp_ulpevent_free(event);
1237 		}
1238 	}
1239 }
1240 
sctp_report_iftsn(struct sctp_ulpq * ulpq,__u32 ftsn)1241 static void sctp_report_iftsn(struct sctp_ulpq *ulpq, __u32 ftsn)
1242 {
1243 	/* Move the Cumulattive TSN Ack ahead. */
1244 	sctp_tsnmap_skip(&ulpq->asoc->peer.tsn_map, ftsn);
1245 	/* purge the fragmentation queue */
1246 	sctp_intl_reasm_flushtsn(ulpq, ftsn);
1247 	/* abort only when it's for all data */
1248 	if (ftsn == sctp_tsnmap_get_max_tsn_seen(&ulpq->asoc->peer.tsn_map))
1249 		sctp_intl_abort_pd(ulpq, GFP_ATOMIC);
1250 }
1251 
sctp_handle_fwdtsn(struct sctp_ulpq * ulpq,struct sctp_chunk * chunk)1252 static void sctp_handle_fwdtsn(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk)
1253 {
1254 	struct sctp_fwdtsn_skip *skip;
1255 
1256 	/* Walk through all the skipped SSNs */
1257 	sctp_walk_fwdtsn(skip, chunk)
1258 		sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
1259 }
1260 
sctp_intl_skip(struct sctp_ulpq * ulpq,__u16 sid,__u32 mid,__u8 flags)1261 static void sctp_intl_skip(struct sctp_ulpq *ulpq, __u16 sid, __u32 mid,
1262 			   __u8 flags)
1263 {
1264 	struct sctp_stream_in *sin = sctp_stream_in(&ulpq->asoc->stream, sid);
1265 	struct sctp_stream *stream  = &ulpq->asoc->stream;
1266 
1267 	if (flags & SCTP_FTSN_U_BIT) {
1268 		if (sin->pd_mode_uo && MID_lt(sin->mid_uo, mid)) {
1269 			sin->pd_mode_uo = 0;
1270 			sctp_intl_stream_abort_pd(ulpq, sid, mid, 0x1,
1271 						  GFP_ATOMIC);
1272 		}
1273 		return;
1274 	}
1275 
1276 	if (MID_lt(mid, sctp_mid_peek(stream, in, sid)))
1277 		return;
1278 
1279 	if (sin->pd_mode) {
1280 		sin->pd_mode = 0;
1281 		sctp_intl_stream_abort_pd(ulpq, sid, mid, 0x0, GFP_ATOMIC);
1282 	}
1283 
1284 	sctp_mid_skip(stream, in, sid, mid);
1285 
1286 	sctp_intl_reap_ordered(ulpq, sid);
1287 }
1288 
sctp_handle_iftsn(struct sctp_ulpq * ulpq,struct sctp_chunk * chunk)1289 static void sctp_handle_iftsn(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk)
1290 {
1291 	struct sctp_ifwdtsn_skip *skip;
1292 
1293 	/* Walk through all the skipped MIDs and abort stream pd if possible */
1294 	sctp_walk_ifwdtsn(skip, chunk)
1295 		sctp_intl_skip(ulpq, ntohs(skip->stream),
1296 			       ntohl(skip->mid), skip->flags);
1297 }
1298 
do_ulpq_tail_event(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)1299 static int do_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event)
1300 {
1301 	struct sk_buff_head temp;
1302 
1303 	skb_queue_head_init(&temp);
1304 	__skb_queue_tail(&temp, sctp_event2skb(event));
1305 	return sctp_ulpq_tail_event(ulpq, &temp);
1306 }
1307 
1308 static struct sctp_stream_interleave sctp_stream_interleave_0 = {
1309 	.data_chunk_len		= sizeof(struct sctp_data_chunk),
1310 	.ftsn_chunk_len		= sizeof(struct sctp_fwdtsn_chunk),
1311 	/* DATA process functions */
1312 	.make_datafrag		= sctp_make_datafrag_empty,
1313 	.assign_number		= sctp_chunk_assign_ssn,
1314 	.validate_data		= sctp_validate_data,
1315 	.ulpevent_data		= sctp_ulpq_tail_data,
1316 	.enqueue_event		= do_ulpq_tail_event,
1317 	.renege_events		= sctp_ulpq_renege,
1318 	.start_pd		= sctp_ulpq_partial_delivery,
1319 	.abort_pd		= sctp_ulpq_abort_pd,
1320 	/* FORWARD-TSN process functions */
1321 	.generate_ftsn		= sctp_generate_fwdtsn,
1322 	.validate_ftsn		= sctp_validate_fwdtsn,
1323 	.report_ftsn		= sctp_report_fwdtsn,
1324 	.handle_ftsn		= sctp_handle_fwdtsn,
1325 };
1326 
do_sctp_enqueue_event(struct sctp_ulpq * ulpq,struct sctp_ulpevent * event)1327 static int do_sctp_enqueue_event(struct sctp_ulpq *ulpq,
1328 				 struct sctp_ulpevent *event)
1329 {
1330 	struct sk_buff_head temp;
1331 
1332 	skb_queue_head_init(&temp);
1333 	__skb_queue_tail(&temp, sctp_event2skb(event));
1334 	return sctp_enqueue_event(ulpq, &temp);
1335 }
1336 
1337 static struct sctp_stream_interleave sctp_stream_interleave_1 = {
1338 	.data_chunk_len		= sizeof(struct sctp_idata_chunk),
1339 	.ftsn_chunk_len		= sizeof(struct sctp_ifwdtsn_chunk),
1340 	/* I-DATA process functions */
1341 	.make_datafrag		= sctp_make_idatafrag_empty,
1342 	.assign_number		= sctp_chunk_assign_mid,
1343 	.validate_data		= sctp_validate_idata,
1344 	.ulpevent_data		= sctp_ulpevent_idata,
1345 	.enqueue_event		= do_sctp_enqueue_event,
1346 	.renege_events		= sctp_renege_events,
1347 	.start_pd		= sctp_intl_start_pd,
1348 	.abort_pd		= sctp_intl_abort_pd,
1349 	/* I-FORWARD-TSN process functions */
1350 	.generate_ftsn		= sctp_generate_iftsn,
1351 	.validate_ftsn		= sctp_validate_iftsn,
1352 	.report_ftsn		= sctp_report_iftsn,
1353 	.handle_ftsn		= sctp_handle_iftsn,
1354 };
1355 
sctp_stream_interleave_init(struct sctp_stream * stream)1356 void sctp_stream_interleave_init(struct sctp_stream *stream)
1357 {
1358 	struct sctp_association *asoc;
1359 
1360 	asoc = container_of(stream, struct sctp_association, stream);
1361 	stream->si = asoc->peer.intl_capable ? &sctp_stream_interleave_1
1362 					     : &sctp_stream_interleave_0;
1363 }
1364