xref: /openbmc/linux/net/sctp/stream.c (revision 95777591)
1 /* SCTP kernel 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  *
7  * This file is part of the SCTP kernel implementation
8  *
9  * This file contains sctp stream maniuplation primitives and helpers.
10  *
11  * This SCTP 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  * This SCTP 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, see
25  * <http://www.gnu.org/licenses/>.
26  *
27  * Please send any bug reports or fixes you make to the
28  * email address(es):
29  *    lksctp developers <linux-sctp@vger.kernel.org>
30  *
31  * Written or modified by:
32  *    Xin Long <lucien.xin@gmail.com>
33  */
34 
35 #include <linux/list.h>
36 #include <net/sctp/sctp.h>
37 #include <net/sctp/sm.h>
38 #include <net/sctp/stream_sched.h>
39 
40 static struct flex_array *fa_alloc(size_t elem_size, size_t elem_count,
41 				   gfp_t gfp)
42 {
43 	struct flex_array *result;
44 	int err;
45 
46 	result = flex_array_alloc(elem_size, elem_count, gfp);
47 	if (result) {
48 		err = flex_array_prealloc(result, 0, elem_count, gfp);
49 		if (err) {
50 			flex_array_free(result);
51 			result = NULL;
52 		}
53 	}
54 
55 	return result;
56 }
57 
58 static void fa_free(struct flex_array *fa)
59 {
60 	if (fa)
61 		flex_array_free(fa);
62 }
63 
64 static void fa_copy(struct flex_array *fa, struct flex_array *from,
65 		    size_t index, size_t count)
66 {
67 	void *elem;
68 
69 	while (count--) {
70 		elem = flex_array_get(from, index);
71 		flex_array_put(fa, index, elem, 0);
72 		index++;
73 	}
74 }
75 
76 static void fa_zero(struct flex_array *fa, size_t index, size_t count)
77 {
78 	void *elem;
79 
80 	while (count--) {
81 		elem = flex_array_get(fa, index);
82 		memset(elem, 0, fa->element_size);
83 		index++;
84 	}
85 }
86 
87 static size_t fa_index(struct flex_array *fa, void *elem, size_t count)
88 {
89 	size_t index = 0;
90 
91 	while (count--) {
92 		if (elem == flex_array_get(fa, index))
93 			break;
94 		index++;
95 	}
96 
97 	return index;
98 }
99 
100 /* Migrates chunks from stream queues to new stream queues if needed,
101  * but not across associations. Also, removes those chunks to streams
102  * higher than the new max.
103  */
104 static void sctp_stream_outq_migrate(struct sctp_stream *stream,
105 				     struct sctp_stream *new, __u16 outcnt)
106 {
107 	struct sctp_association *asoc;
108 	struct sctp_chunk *ch, *temp;
109 	struct sctp_outq *outq;
110 	int i;
111 
112 	asoc = container_of(stream, struct sctp_association, stream);
113 	outq = &asoc->outqueue;
114 
115 	list_for_each_entry_safe(ch, temp, &outq->out_chunk_list, list) {
116 		__u16 sid = sctp_chunk_stream_no(ch);
117 
118 		if (sid < outcnt)
119 			continue;
120 
121 		sctp_sched_dequeue_common(outq, ch);
122 		/* No need to call dequeue_done here because
123 		 * the chunks are not scheduled by now.
124 		 */
125 
126 		/* Mark as failed send. */
127 		sctp_chunk_fail(ch, (__force __u32)SCTP_ERROR_INV_STRM);
128 		if (asoc->peer.prsctp_capable &&
129 		    SCTP_PR_PRIO_ENABLED(ch->sinfo.sinfo_flags))
130 			asoc->sent_cnt_removable--;
131 
132 		sctp_chunk_free(ch);
133 	}
134 
135 	if (new) {
136 		/* Here we actually move the old ext stuff into the new
137 		 * buffer, because we want to keep it. Then
138 		 * sctp_stream_update will swap ->out pointers.
139 		 */
140 		for (i = 0; i < outcnt; i++) {
141 			kfree(SCTP_SO(new, i)->ext);
142 			SCTP_SO(new, i)->ext = SCTP_SO(stream, i)->ext;
143 			SCTP_SO(stream, i)->ext = NULL;
144 		}
145 	}
146 
147 	for (i = outcnt; i < stream->outcnt; i++) {
148 		kfree(SCTP_SO(stream, i)->ext);
149 		SCTP_SO(stream, i)->ext = NULL;
150 	}
151 }
152 
153 static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
154 				 gfp_t gfp)
155 {
156 	struct flex_array *out;
157 	size_t elem_size = sizeof(struct sctp_stream_out);
158 
159 	out = fa_alloc(elem_size, outcnt, gfp);
160 	if (!out)
161 		return -ENOMEM;
162 
163 	if (stream->out) {
164 		fa_copy(out, stream->out, 0, min(outcnt, stream->outcnt));
165 		if (stream->out_curr) {
166 			size_t index = fa_index(stream->out, stream->out_curr,
167 						stream->outcnt);
168 
169 			BUG_ON(index == stream->outcnt);
170 			stream->out_curr = flex_array_get(out, index);
171 		}
172 		fa_free(stream->out);
173 	}
174 
175 	if (outcnt > stream->outcnt)
176 		fa_zero(out, stream->outcnt, (outcnt - stream->outcnt));
177 
178 	stream->out = out;
179 
180 	return 0;
181 }
182 
183 static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
184 				gfp_t gfp)
185 {
186 	struct flex_array *in;
187 	size_t elem_size = sizeof(struct sctp_stream_in);
188 
189 	in = fa_alloc(elem_size, incnt, gfp);
190 	if (!in)
191 		return -ENOMEM;
192 
193 	if (stream->in) {
194 		fa_copy(in, stream->in, 0, min(incnt, stream->incnt));
195 		fa_free(stream->in);
196 	}
197 
198 	if (incnt > stream->incnt)
199 		fa_zero(in, stream->incnt, (incnt - stream->incnt));
200 
201 	stream->in = in;
202 
203 	return 0;
204 }
205 
206 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
207 		     gfp_t gfp)
208 {
209 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
210 	int i, ret = 0;
211 
212 	gfp |= __GFP_NOWARN;
213 
214 	/* Initial stream->out size may be very big, so free it and alloc
215 	 * a new one with new outcnt to save memory if needed.
216 	 */
217 	if (outcnt == stream->outcnt)
218 		goto in;
219 
220 	/* Filter out chunks queued on streams that won't exist anymore */
221 	sched->unsched_all(stream);
222 	sctp_stream_outq_migrate(stream, NULL, outcnt);
223 	sched->sched_all(stream);
224 
225 	ret = sctp_stream_alloc_out(stream, outcnt, gfp);
226 	if (ret)
227 		goto out;
228 
229 	stream->outcnt = outcnt;
230 	for (i = 0; i < stream->outcnt; i++)
231 		SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
232 
233 	sched->init(stream);
234 
235 in:
236 	sctp_stream_interleave_init(stream);
237 	if (!incnt)
238 		goto out;
239 
240 	ret = sctp_stream_alloc_in(stream, incnt, gfp);
241 	if (ret) {
242 		sched->free(stream);
243 		fa_free(stream->out);
244 		stream->out = NULL;
245 		stream->outcnt = 0;
246 		goto out;
247 	}
248 
249 	stream->incnt = incnt;
250 
251 out:
252 	return ret;
253 }
254 
255 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid)
256 {
257 	struct sctp_stream_out_ext *soute;
258 
259 	soute = kzalloc(sizeof(*soute), GFP_KERNEL);
260 	if (!soute)
261 		return -ENOMEM;
262 	SCTP_SO(stream, sid)->ext = soute;
263 
264 	return sctp_sched_init_sid(stream, sid, GFP_KERNEL);
265 }
266 
267 void sctp_stream_free(struct sctp_stream *stream)
268 {
269 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
270 	int i;
271 
272 	sched->free(stream);
273 	for (i = 0; i < stream->outcnt; i++)
274 		kfree(SCTP_SO(stream, i)->ext);
275 	fa_free(stream->out);
276 	fa_free(stream->in);
277 }
278 
279 void sctp_stream_clear(struct sctp_stream *stream)
280 {
281 	int i;
282 
283 	for (i = 0; i < stream->outcnt; i++) {
284 		SCTP_SO(stream, i)->mid = 0;
285 		SCTP_SO(stream, i)->mid_uo = 0;
286 	}
287 
288 	for (i = 0; i < stream->incnt; i++)
289 		SCTP_SI(stream, i)->mid = 0;
290 }
291 
292 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
293 {
294 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
295 
296 	sched->unsched_all(stream);
297 	sctp_stream_outq_migrate(stream, new, new->outcnt);
298 	sctp_stream_free(stream);
299 
300 	stream->out = new->out;
301 	stream->in  = new->in;
302 	stream->outcnt = new->outcnt;
303 	stream->incnt  = new->incnt;
304 
305 	sched->sched_all(stream);
306 
307 	new->out = NULL;
308 	new->in  = NULL;
309 	new->outcnt = 0;
310 	new->incnt  = 0;
311 }
312 
313 static int sctp_send_reconf(struct sctp_association *asoc,
314 			    struct sctp_chunk *chunk)
315 {
316 	struct net *net = sock_net(asoc->base.sk);
317 	int retval = 0;
318 
319 	retval = sctp_primitive_RECONF(net, asoc, chunk);
320 	if (retval)
321 		sctp_chunk_free(chunk);
322 
323 	return retval;
324 }
325 
326 static bool sctp_stream_outq_is_empty(struct sctp_stream *stream,
327 				      __u16 str_nums, __be16 *str_list)
328 {
329 	struct sctp_association *asoc;
330 	__u16 i;
331 
332 	asoc = container_of(stream, struct sctp_association, stream);
333 	if (!asoc->outqueue.out_qlen)
334 		return true;
335 
336 	if (!str_nums)
337 		return false;
338 
339 	for (i = 0; i < str_nums; i++) {
340 		__u16 sid = ntohs(str_list[i]);
341 
342 		if (SCTP_SO(stream, sid)->ext &&
343 		    !list_empty(&SCTP_SO(stream, sid)->ext->outq))
344 			return false;
345 	}
346 
347 	return true;
348 }
349 
350 int sctp_send_reset_streams(struct sctp_association *asoc,
351 			    struct sctp_reset_streams *params)
352 {
353 	struct sctp_stream *stream = &asoc->stream;
354 	__u16 i, str_nums, *str_list;
355 	struct sctp_chunk *chunk;
356 	int retval = -EINVAL;
357 	__be16 *nstr_list;
358 	bool out, in;
359 
360 	if (!asoc->peer.reconf_capable ||
361 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ)) {
362 		retval = -ENOPROTOOPT;
363 		goto out;
364 	}
365 
366 	if (asoc->strreset_outstanding) {
367 		retval = -EINPROGRESS;
368 		goto out;
369 	}
370 
371 	out = params->srs_flags & SCTP_STREAM_RESET_OUTGOING;
372 	in  = params->srs_flags & SCTP_STREAM_RESET_INCOMING;
373 	if (!out && !in)
374 		goto out;
375 
376 	str_nums = params->srs_number_streams;
377 	str_list = params->srs_stream_list;
378 	if (str_nums) {
379 		int param_len = 0;
380 
381 		if (out) {
382 			for (i = 0; i < str_nums; i++)
383 				if (str_list[i] >= stream->outcnt)
384 					goto out;
385 
386 			param_len = str_nums * sizeof(__u16) +
387 				    sizeof(struct sctp_strreset_outreq);
388 		}
389 
390 		if (in) {
391 			for (i = 0; i < str_nums; i++)
392 				if (str_list[i] >= stream->incnt)
393 					goto out;
394 
395 			param_len += str_nums * sizeof(__u16) +
396 				     sizeof(struct sctp_strreset_inreq);
397 		}
398 
399 		if (param_len > SCTP_MAX_CHUNK_LEN -
400 				sizeof(struct sctp_reconf_chunk))
401 			goto out;
402 	}
403 
404 	nstr_list = kcalloc(str_nums, sizeof(__be16), GFP_KERNEL);
405 	if (!nstr_list) {
406 		retval = -ENOMEM;
407 		goto out;
408 	}
409 
410 	for (i = 0; i < str_nums; i++)
411 		nstr_list[i] = htons(str_list[i]);
412 
413 	if (out && !sctp_stream_outq_is_empty(stream, str_nums, nstr_list)) {
414 		retval = -EAGAIN;
415 		goto out;
416 	}
417 
418 	chunk = sctp_make_strreset_req(asoc, str_nums, nstr_list, out, in);
419 
420 	kfree(nstr_list);
421 
422 	if (!chunk) {
423 		retval = -ENOMEM;
424 		goto out;
425 	}
426 
427 	if (out) {
428 		if (str_nums)
429 			for (i = 0; i < str_nums; i++)
430 				SCTP_SO(stream, str_list[i])->state =
431 						       SCTP_STREAM_CLOSED;
432 		else
433 			for (i = 0; i < stream->outcnt; i++)
434 				SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
435 	}
436 
437 	asoc->strreset_chunk = chunk;
438 	sctp_chunk_hold(asoc->strreset_chunk);
439 
440 	retval = sctp_send_reconf(asoc, chunk);
441 	if (retval) {
442 		sctp_chunk_put(asoc->strreset_chunk);
443 		asoc->strreset_chunk = NULL;
444 		if (!out)
445 			goto out;
446 
447 		if (str_nums)
448 			for (i = 0; i < str_nums; i++)
449 				SCTP_SO(stream, str_list[i])->state =
450 						       SCTP_STREAM_OPEN;
451 		else
452 			for (i = 0; i < stream->outcnt; i++)
453 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
454 
455 		goto out;
456 	}
457 
458 	asoc->strreset_outstanding = out + in;
459 
460 out:
461 	return retval;
462 }
463 
464 int sctp_send_reset_assoc(struct sctp_association *asoc)
465 {
466 	struct sctp_stream *stream = &asoc->stream;
467 	struct sctp_chunk *chunk = NULL;
468 	int retval;
469 	__u16 i;
470 
471 	if (!asoc->peer.reconf_capable ||
472 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
473 		return -ENOPROTOOPT;
474 
475 	if (asoc->strreset_outstanding)
476 		return -EINPROGRESS;
477 
478 	if (!sctp_outq_is_empty(&asoc->outqueue))
479 		return -EAGAIN;
480 
481 	chunk = sctp_make_strreset_tsnreq(asoc);
482 	if (!chunk)
483 		return -ENOMEM;
484 
485 	/* Block further xmit of data until this request is completed */
486 	for (i = 0; i < stream->outcnt; i++)
487 		SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
488 
489 	asoc->strreset_chunk = chunk;
490 	sctp_chunk_hold(asoc->strreset_chunk);
491 
492 	retval = sctp_send_reconf(asoc, chunk);
493 	if (retval) {
494 		sctp_chunk_put(asoc->strreset_chunk);
495 		asoc->strreset_chunk = NULL;
496 
497 		for (i = 0; i < stream->outcnt; i++)
498 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
499 
500 		return retval;
501 	}
502 
503 	asoc->strreset_outstanding = 1;
504 
505 	return 0;
506 }
507 
508 int sctp_send_add_streams(struct sctp_association *asoc,
509 			  struct sctp_add_streams *params)
510 {
511 	struct sctp_stream *stream = &asoc->stream;
512 	struct sctp_chunk *chunk = NULL;
513 	int retval;
514 	__u32 outcnt, incnt;
515 	__u16 out, in;
516 
517 	if (!asoc->peer.reconf_capable ||
518 	    !(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ)) {
519 		retval = -ENOPROTOOPT;
520 		goto out;
521 	}
522 
523 	if (asoc->strreset_outstanding) {
524 		retval = -EINPROGRESS;
525 		goto out;
526 	}
527 
528 	out = params->sas_outstrms;
529 	in  = params->sas_instrms;
530 	outcnt = stream->outcnt + out;
531 	incnt = stream->incnt + in;
532 	if (outcnt > SCTP_MAX_STREAM || incnt > SCTP_MAX_STREAM ||
533 	    (!out && !in)) {
534 		retval = -EINVAL;
535 		goto out;
536 	}
537 
538 	if (out) {
539 		retval = sctp_stream_alloc_out(stream, outcnt, GFP_KERNEL);
540 		if (retval)
541 			goto out;
542 	}
543 
544 	chunk = sctp_make_strreset_addstrm(asoc, out, in);
545 	if (!chunk) {
546 		retval = -ENOMEM;
547 		goto out;
548 	}
549 
550 	asoc->strreset_chunk = chunk;
551 	sctp_chunk_hold(asoc->strreset_chunk);
552 
553 	retval = sctp_send_reconf(asoc, chunk);
554 	if (retval) {
555 		sctp_chunk_put(asoc->strreset_chunk);
556 		asoc->strreset_chunk = NULL;
557 		goto out;
558 	}
559 
560 	stream->outcnt = outcnt;
561 
562 	asoc->strreset_outstanding = !!out + !!in;
563 
564 out:
565 	return retval;
566 }
567 
568 static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param(
569 			struct sctp_association *asoc, __be32 resp_seq,
570 			__be16 type)
571 {
572 	struct sctp_chunk *chunk = asoc->strreset_chunk;
573 	struct sctp_reconf_chunk *hdr;
574 	union sctp_params param;
575 
576 	if (!chunk)
577 		return NULL;
578 
579 	hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
580 	sctp_walk_params(param, hdr, params) {
581 		/* sctp_strreset_tsnreq is actually the basic structure
582 		 * of all stream reconf params, so it's safe to use it
583 		 * to access request_seq.
584 		 */
585 		struct sctp_strreset_tsnreq *req = param.v;
586 
587 		if ((!resp_seq || req->request_seq == resp_seq) &&
588 		    (!type || type == req->param_hdr.type))
589 			return param.v;
590 	}
591 
592 	return NULL;
593 }
594 
595 static void sctp_update_strreset_result(struct sctp_association *asoc,
596 					__u32 result)
597 {
598 	asoc->strreset_result[1] = asoc->strreset_result[0];
599 	asoc->strreset_result[0] = result;
600 }
601 
602 struct sctp_chunk *sctp_process_strreset_outreq(
603 				struct sctp_association *asoc,
604 				union sctp_params param,
605 				struct sctp_ulpevent **evp)
606 {
607 	struct sctp_strreset_outreq *outreq = param.v;
608 	struct sctp_stream *stream = &asoc->stream;
609 	__u32 result = SCTP_STRRESET_DENIED;
610 	__be16 *str_p = NULL;
611 	__u32 request_seq;
612 	__u16 i, nums;
613 
614 	request_seq = ntohl(outreq->request_seq);
615 
616 	if (ntohl(outreq->send_reset_at_tsn) >
617 	    sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) {
618 		result = SCTP_STRRESET_IN_PROGRESS;
619 		goto err;
620 	}
621 
622 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
623 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
624 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
625 		goto err;
626 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
627 		i = asoc->strreset_inseq - request_seq - 1;
628 		result = asoc->strreset_result[i];
629 		goto err;
630 	}
631 	asoc->strreset_inseq++;
632 
633 	/* Check strreset_enable after inseq inc, as sender cannot tell
634 	 * the peer doesn't enable strreset after receiving response with
635 	 * result denied, as well as to keep consistent with bsd.
636 	 */
637 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
638 		goto out;
639 
640 	nums = (ntohs(param.p->length) - sizeof(*outreq)) / sizeof(__u16);
641 	str_p = outreq->list_of_streams;
642 	for (i = 0; i < nums; i++) {
643 		if (ntohs(str_p[i]) >= stream->incnt) {
644 			result = SCTP_STRRESET_ERR_WRONG_SSN;
645 			goto out;
646 		}
647 	}
648 
649 	if (asoc->strreset_chunk) {
650 		if (!sctp_chunk_lookup_strreset_param(
651 				asoc, outreq->response_seq,
652 				SCTP_PARAM_RESET_IN_REQUEST)) {
653 			/* same process with outstanding isn't 0 */
654 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
655 			goto out;
656 		}
657 
658 		asoc->strreset_outstanding--;
659 		asoc->strreset_outseq++;
660 
661 		if (!asoc->strreset_outstanding) {
662 			struct sctp_transport *t;
663 
664 			t = asoc->strreset_chunk->transport;
665 			if (del_timer(&t->reconf_timer))
666 				sctp_transport_put(t);
667 
668 			sctp_chunk_put(asoc->strreset_chunk);
669 			asoc->strreset_chunk = NULL;
670 		}
671 	}
672 
673 	if (nums)
674 		for (i = 0; i < nums; i++)
675 			SCTP_SI(stream, ntohs(str_p[i]))->mid = 0;
676 	else
677 		for (i = 0; i < stream->incnt; i++)
678 			SCTP_SI(stream, i)->mid = 0;
679 
680 	result = SCTP_STRRESET_PERFORMED;
681 
682 	*evp = sctp_ulpevent_make_stream_reset_event(asoc,
683 		SCTP_STREAM_RESET_INCOMING_SSN, nums, str_p, GFP_ATOMIC);
684 
685 out:
686 	sctp_update_strreset_result(asoc, result);
687 err:
688 	return sctp_make_strreset_resp(asoc, result, request_seq);
689 }
690 
691 struct sctp_chunk *sctp_process_strreset_inreq(
692 				struct sctp_association *asoc,
693 				union sctp_params param,
694 				struct sctp_ulpevent **evp)
695 {
696 	struct sctp_strreset_inreq *inreq = param.v;
697 	struct sctp_stream *stream = &asoc->stream;
698 	__u32 result = SCTP_STRRESET_DENIED;
699 	struct sctp_chunk *chunk = NULL;
700 	__u32 request_seq;
701 	__u16 i, nums;
702 	__be16 *str_p;
703 
704 	request_seq = ntohl(inreq->request_seq);
705 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
706 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
707 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
708 		goto err;
709 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
710 		i = asoc->strreset_inseq - request_seq - 1;
711 		result = asoc->strreset_result[i];
712 		if (result == SCTP_STRRESET_PERFORMED)
713 			return NULL;
714 		goto err;
715 	}
716 	asoc->strreset_inseq++;
717 
718 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
719 		goto out;
720 
721 	if (asoc->strreset_outstanding) {
722 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
723 		goto out;
724 	}
725 
726 	nums = (ntohs(param.p->length) - sizeof(*inreq)) / sizeof(__u16);
727 	str_p = inreq->list_of_streams;
728 	for (i = 0; i < nums; i++) {
729 		if (ntohs(str_p[i]) >= stream->outcnt) {
730 			result = SCTP_STRRESET_ERR_WRONG_SSN;
731 			goto out;
732 		}
733 	}
734 
735 	if (!sctp_stream_outq_is_empty(stream, nums, str_p)) {
736 		result = SCTP_STRRESET_IN_PROGRESS;
737 		asoc->strreset_inseq--;
738 		goto err;
739 	}
740 
741 	chunk = sctp_make_strreset_req(asoc, nums, str_p, 1, 0);
742 	if (!chunk)
743 		goto out;
744 
745 	if (nums)
746 		for (i = 0; i < nums; i++)
747 			SCTP_SO(stream, ntohs(str_p[i]))->state =
748 					       SCTP_STREAM_CLOSED;
749 	else
750 		for (i = 0; i < stream->outcnt; i++)
751 			SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
752 
753 	asoc->strreset_chunk = chunk;
754 	asoc->strreset_outstanding = 1;
755 	sctp_chunk_hold(asoc->strreset_chunk);
756 
757 	result = SCTP_STRRESET_PERFORMED;
758 
759 out:
760 	sctp_update_strreset_result(asoc, result);
761 err:
762 	if (!chunk)
763 		chunk =  sctp_make_strreset_resp(asoc, result, request_seq);
764 
765 	return chunk;
766 }
767 
768 struct sctp_chunk *sctp_process_strreset_tsnreq(
769 				struct sctp_association *asoc,
770 				union sctp_params param,
771 				struct sctp_ulpevent **evp)
772 {
773 	__u32 init_tsn = 0, next_tsn = 0, max_tsn_seen;
774 	struct sctp_strreset_tsnreq *tsnreq = param.v;
775 	struct sctp_stream *stream = &asoc->stream;
776 	__u32 result = SCTP_STRRESET_DENIED;
777 	__u32 request_seq;
778 	__u16 i;
779 
780 	request_seq = ntohl(tsnreq->request_seq);
781 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
782 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
783 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
784 		goto err;
785 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
786 		i = asoc->strreset_inseq - request_seq - 1;
787 		result = asoc->strreset_result[i];
788 		if (result == SCTP_STRRESET_PERFORMED) {
789 			next_tsn = asoc->ctsn_ack_point + 1;
790 			init_tsn =
791 				sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1;
792 		}
793 		goto err;
794 	}
795 
796 	if (!sctp_outq_is_empty(&asoc->outqueue)) {
797 		result = SCTP_STRRESET_IN_PROGRESS;
798 		goto err;
799 	}
800 
801 	asoc->strreset_inseq++;
802 
803 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
804 		goto out;
805 
806 	if (asoc->strreset_outstanding) {
807 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
808 		goto out;
809 	}
810 
811 	/* G4: The same processing as though a FWD-TSN chunk (as defined in
812 	 *     [RFC3758]) with all streams affected and a new cumulative TSN
813 	 *     ACK of the Receiver's Next TSN minus 1 were received MUST be
814 	 *     performed.
815 	 */
816 	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
817 	asoc->stream.si->report_ftsn(&asoc->ulpq, max_tsn_seen);
818 
819 	/* G1: Compute an appropriate value for the Receiver's Next TSN -- the
820 	 *     TSN that the peer should use to send the next DATA chunk.  The
821 	 *     value SHOULD be the smallest TSN not acknowledged by the
822 	 *     receiver of the request plus 2^31.
823 	 */
824 	init_tsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + (1 << 31);
825 	sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
826 			 init_tsn, GFP_ATOMIC);
827 
828 	/* G3: The same processing as though a SACK chunk with no gap report
829 	 *     and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
830 	 *     received MUST be performed.
831 	 */
832 	sctp_outq_free(&asoc->outqueue);
833 
834 	/* G2: Compute an appropriate value for the local endpoint's next TSN,
835 	 *     i.e., the next TSN assigned by the receiver of the SSN/TSN reset
836 	 *     chunk.  The value SHOULD be the highest TSN sent by the receiver
837 	 *     of the request plus 1.
838 	 */
839 	next_tsn = asoc->next_tsn;
840 	asoc->ctsn_ack_point = next_tsn - 1;
841 	asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
842 
843 	/* G5:  The next expected and outgoing SSNs MUST be reset to 0 for all
844 	 *      incoming and outgoing streams.
845 	 */
846 	for (i = 0; i < stream->outcnt; i++) {
847 		SCTP_SO(stream, i)->mid = 0;
848 		SCTP_SO(stream, i)->mid_uo = 0;
849 	}
850 	for (i = 0; i < stream->incnt; i++)
851 		SCTP_SI(stream, i)->mid = 0;
852 
853 	result = SCTP_STRRESET_PERFORMED;
854 
855 	*evp = sctp_ulpevent_make_assoc_reset_event(asoc, 0, init_tsn,
856 						    next_tsn, GFP_ATOMIC);
857 
858 out:
859 	sctp_update_strreset_result(asoc, result);
860 err:
861 	return sctp_make_strreset_tsnresp(asoc, result, request_seq,
862 					  next_tsn, init_tsn);
863 }
864 
865 struct sctp_chunk *sctp_process_strreset_addstrm_out(
866 				struct sctp_association *asoc,
867 				union sctp_params param,
868 				struct sctp_ulpevent **evp)
869 {
870 	struct sctp_strreset_addstrm *addstrm = param.v;
871 	struct sctp_stream *stream = &asoc->stream;
872 	__u32 result = SCTP_STRRESET_DENIED;
873 	__u32 request_seq, incnt;
874 	__u16 in, i;
875 
876 	request_seq = ntohl(addstrm->request_seq);
877 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
878 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
879 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
880 		goto err;
881 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
882 		i = asoc->strreset_inseq - request_seq - 1;
883 		result = asoc->strreset_result[i];
884 		goto err;
885 	}
886 	asoc->strreset_inseq++;
887 
888 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
889 		goto out;
890 
891 	in = ntohs(addstrm->number_of_streams);
892 	incnt = stream->incnt + in;
893 	if (!in || incnt > SCTP_MAX_STREAM)
894 		goto out;
895 
896 	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
897 		goto out;
898 
899 	if (asoc->strreset_chunk) {
900 		if (!sctp_chunk_lookup_strreset_param(
901 			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
902 			/* same process with outstanding isn't 0 */
903 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
904 			goto out;
905 		}
906 
907 		asoc->strreset_outstanding--;
908 		asoc->strreset_outseq++;
909 
910 		if (!asoc->strreset_outstanding) {
911 			struct sctp_transport *t;
912 
913 			t = asoc->strreset_chunk->transport;
914 			if (del_timer(&t->reconf_timer))
915 				sctp_transport_put(t);
916 
917 			sctp_chunk_put(asoc->strreset_chunk);
918 			asoc->strreset_chunk = NULL;
919 		}
920 	}
921 
922 	stream->incnt = incnt;
923 
924 	result = SCTP_STRRESET_PERFORMED;
925 
926 	*evp = sctp_ulpevent_make_stream_change_event(asoc,
927 		0, ntohs(addstrm->number_of_streams), 0, GFP_ATOMIC);
928 
929 out:
930 	sctp_update_strreset_result(asoc, result);
931 err:
932 	return sctp_make_strreset_resp(asoc, result, request_seq);
933 }
934 
935 struct sctp_chunk *sctp_process_strreset_addstrm_in(
936 				struct sctp_association *asoc,
937 				union sctp_params param,
938 				struct sctp_ulpevent **evp)
939 {
940 	struct sctp_strreset_addstrm *addstrm = param.v;
941 	struct sctp_stream *stream = &asoc->stream;
942 	__u32 result = SCTP_STRRESET_DENIED;
943 	struct sctp_chunk *chunk = NULL;
944 	__u32 request_seq, outcnt;
945 	__u16 out, i;
946 	int ret;
947 
948 	request_seq = ntohl(addstrm->request_seq);
949 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
950 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
951 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
952 		goto err;
953 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
954 		i = asoc->strreset_inseq - request_seq - 1;
955 		result = asoc->strreset_result[i];
956 		if (result == SCTP_STRRESET_PERFORMED)
957 			return NULL;
958 		goto err;
959 	}
960 	asoc->strreset_inseq++;
961 
962 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
963 		goto out;
964 
965 	if (asoc->strreset_outstanding) {
966 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
967 		goto out;
968 	}
969 
970 	out = ntohs(addstrm->number_of_streams);
971 	outcnt = stream->outcnt + out;
972 	if (!out || outcnt > SCTP_MAX_STREAM)
973 		goto out;
974 
975 	ret = sctp_stream_alloc_out(stream, outcnt, GFP_ATOMIC);
976 	if (ret)
977 		goto out;
978 
979 	chunk = sctp_make_strreset_addstrm(asoc, out, 0);
980 	if (!chunk)
981 		goto out;
982 
983 	asoc->strreset_chunk = chunk;
984 	asoc->strreset_outstanding = 1;
985 	sctp_chunk_hold(asoc->strreset_chunk);
986 
987 	stream->outcnt = outcnt;
988 
989 	result = SCTP_STRRESET_PERFORMED;
990 
991 out:
992 	sctp_update_strreset_result(asoc, result);
993 err:
994 	if (!chunk)
995 		chunk = sctp_make_strreset_resp(asoc, result, request_seq);
996 
997 	return chunk;
998 }
999 
1000 struct sctp_chunk *sctp_process_strreset_resp(
1001 				struct sctp_association *asoc,
1002 				union sctp_params param,
1003 				struct sctp_ulpevent **evp)
1004 {
1005 	struct sctp_stream *stream = &asoc->stream;
1006 	struct sctp_strreset_resp *resp = param.v;
1007 	struct sctp_transport *t;
1008 	__u16 i, nums, flags = 0;
1009 	struct sctp_paramhdr *req;
1010 	__u32 result;
1011 
1012 	req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0);
1013 	if (!req)
1014 		return NULL;
1015 
1016 	result = ntohl(resp->result);
1017 	if (result != SCTP_STRRESET_PERFORMED) {
1018 		/* if in progress, do nothing but retransmit */
1019 		if (result == SCTP_STRRESET_IN_PROGRESS)
1020 			return NULL;
1021 		else if (result == SCTP_STRRESET_DENIED)
1022 			flags = SCTP_STREAM_RESET_DENIED;
1023 		else
1024 			flags = SCTP_STREAM_RESET_FAILED;
1025 	}
1026 
1027 	if (req->type == SCTP_PARAM_RESET_OUT_REQUEST) {
1028 		struct sctp_strreset_outreq *outreq;
1029 		__be16 *str_p;
1030 
1031 		outreq = (struct sctp_strreset_outreq *)req;
1032 		str_p = outreq->list_of_streams;
1033 		nums = (ntohs(outreq->param_hdr.length) - sizeof(*outreq)) /
1034 		       sizeof(__u16);
1035 
1036 		if (result == SCTP_STRRESET_PERFORMED) {
1037 			struct sctp_stream_out *sout;
1038 			if (nums) {
1039 				for (i = 0; i < nums; i++) {
1040 					sout = SCTP_SO(stream, ntohs(str_p[i]));
1041 					sout->mid = 0;
1042 					sout->mid_uo = 0;
1043 				}
1044 			} else {
1045 				for (i = 0; i < stream->outcnt; i++) {
1046 					sout = SCTP_SO(stream, i);
1047 					sout->mid = 0;
1048 					sout->mid_uo = 0;
1049 				}
1050 			}
1051 		}
1052 
1053 		flags |= SCTP_STREAM_RESET_OUTGOING_SSN;
1054 
1055 		for (i = 0; i < stream->outcnt; i++)
1056 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1057 
1058 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
1059 			nums, str_p, GFP_ATOMIC);
1060 	} else if (req->type == SCTP_PARAM_RESET_IN_REQUEST) {
1061 		struct sctp_strreset_inreq *inreq;
1062 		__be16 *str_p;
1063 
1064 		/* if the result is performed, it's impossible for inreq */
1065 		if (result == SCTP_STRRESET_PERFORMED)
1066 			return NULL;
1067 
1068 		inreq = (struct sctp_strreset_inreq *)req;
1069 		str_p = inreq->list_of_streams;
1070 		nums = (ntohs(inreq->param_hdr.length) - sizeof(*inreq)) /
1071 		       sizeof(__u16);
1072 
1073 		flags |= SCTP_STREAM_RESET_INCOMING_SSN;
1074 
1075 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
1076 			nums, str_p, GFP_ATOMIC);
1077 	} else if (req->type == SCTP_PARAM_RESET_TSN_REQUEST) {
1078 		struct sctp_strreset_resptsn *resptsn;
1079 		__u32 stsn, rtsn;
1080 
1081 		/* check for resptsn, as sctp_verify_reconf didn't do it*/
1082 		if (ntohs(param.p->length) != sizeof(*resptsn))
1083 			return NULL;
1084 
1085 		resptsn = (struct sctp_strreset_resptsn *)resp;
1086 		stsn = ntohl(resptsn->senders_next_tsn);
1087 		rtsn = ntohl(resptsn->receivers_next_tsn);
1088 
1089 		if (result == SCTP_STRRESET_PERFORMED) {
1090 			__u32 mtsn = sctp_tsnmap_get_max_tsn_seen(
1091 						&asoc->peer.tsn_map);
1092 			LIST_HEAD(temp);
1093 
1094 			asoc->stream.si->report_ftsn(&asoc->ulpq, mtsn);
1095 
1096 			sctp_tsnmap_init(&asoc->peer.tsn_map,
1097 					 SCTP_TSN_MAP_INITIAL,
1098 					 stsn, GFP_ATOMIC);
1099 
1100 			/* Clean up sacked and abandoned queues only. As the
1101 			 * out_chunk_list may not be empty, splice it to temp,
1102 			 * then get it back after sctp_outq_free is done.
1103 			 */
1104 			list_splice_init(&asoc->outqueue.out_chunk_list, &temp);
1105 			sctp_outq_free(&asoc->outqueue);
1106 			list_splice_init(&temp, &asoc->outqueue.out_chunk_list);
1107 
1108 			asoc->next_tsn = rtsn;
1109 			asoc->ctsn_ack_point = asoc->next_tsn - 1;
1110 			asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1111 
1112 			for (i = 0; i < stream->outcnt; i++) {
1113 				SCTP_SO(stream, i)->mid = 0;
1114 				SCTP_SO(stream, i)->mid_uo = 0;
1115 			}
1116 			for (i = 0; i < stream->incnt; i++)
1117 				SCTP_SI(stream, i)->mid = 0;
1118 		}
1119 
1120 		for (i = 0; i < stream->outcnt; i++)
1121 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1122 
1123 		*evp = sctp_ulpevent_make_assoc_reset_event(asoc, flags,
1124 			stsn, rtsn, GFP_ATOMIC);
1125 	} else if (req->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS) {
1126 		struct sctp_strreset_addstrm *addstrm;
1127 		__u16 number;
1128 
1129 		addstrm = (struct sctp_strreset_addstrm *)req;
1130 		nums = ntohs(addstrm->number_of_streams);
1131 		number = stream->outcnt - nums;
1132 
1133 		if (result == SCTP_STRRESET_PERFORMED)
1134 			for (i = number; i < stream->outcnt; i++)
1135 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1136 		else
1137 			stream->outcnt = number;
1138 
1139 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1140 			0, nums, GFP_ATOMIC);
1141 	} else if (req->type == SCTP_PARAM_RESET_ADD_IN_STREAMS) {
1142 		struct sctp_strreset_addstrm *addstrm;
1143 
1144 		/* if the result is performed, it's impossible for addstrm in
1145 		 * request.
1146 		 */
1147 		if (result == SCTP_STRRESET_PERFORMED)
1148 			return NULL;
1149 
1150 		addstrm = (struct sctp_strreset_addstrm *)req;
1151 		nums = ntohs(addstrm->number_of_streams);
1152 
1153 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1154 			nums, 0, GFP_ATOMIC);
1155 	}
1156 
1157 	asoc->strreset_outstanding--;
1158 	asoc->strreset_outseq++;
1159 
1160 	/* remove everything for this reconf request */
1161 	if (!asoc->strreset_outstanding) {
1162 		t = asoc->strreset_chunk->transport;
1163 		if (del_timer(&t->reconf_timer))
1164 			sctp_transport_put(t);
1165 
1166 		sctp_chunk_put(asoc->strreset_chunk);
1167 		asoc->strreset_chunk = NULL;
1168 	}
1169 
1170 	return NULL;
1171 }
1172