xref: /openbmc/linux/net/sctp/stream.c (revision c8ec3743)
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 }
150 
151 static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
152 				 gfp_t gfp)
153 {
154 	struct flex_array *out;
155 	size_t elem_size = sizeof(struct sctp_stream_out);
156 
157 	out = fa_alloc(elem_size, outcnt, gfp);
158 	if (!out)
159 		return -ENOMEM;
160 
161 	if (stream->out) {
162 		fa_copy(out, stream->out, 0, min(outcnt, stream->outcnt));
163 		if (stream->out_curr) {
164 			size_t index = fa_index(stream->out, stream->out_curr,
165 						stream->outcnt);
166 
167 			BUG_ON(index == stream->outcnt);
168 			stream->out_curr = flex_array_get(out, index);
169 		}
170 		fa_free(stream->out);
171 	}
172 
173 	if (outcnt > stream->outcnt)
174 		fa_zero(out, stream->outcnt, (outcnt - stream->outcnt));
175 
176 	stream->out = out;
177 
178 	return 0;
179 }
180 
181 static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
182 				gfp_t gfp)
183 {
184 	struct flex_array *in;
185 	size_t elem_size = sizeof(struct sctp_stream_in);
186 
187 	in = fa_alloc(elem_size, incnt, gfp);
188 	if (!in)
189 		return -ENOMEM;
190 
191 	if (stream->in) {
192 		fa_copy(in, stream->in, 0, min(incnt, stream->incnt));
193 		fa_free(stream->in);
194 	}
195 
196 	if (incnt > stream->incnt)
197 		fa_zero(in, stream->incnt, (incnt - stream->incnt));
198 
199 	stream->in = in;
200 
201 	return 0;
202 }
203 
204 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
205 		     gfp_t gfp)
206 {
207 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
208 	int i, ret = 0;
209 
210 	gfp |= __GFP_NOWARN;
211 
212 	/* Initial stream->out size may be very big, so free it and alloc
213 	 * a new one with new outcnt to save memory if needed.
214 	 */
215 	if (outcnt == stream->outcnt)
216 		goto in;
217 
218 	/* Filter out chunks queued on streams that won't exist anymore */
219 	sched->unsched_all(stream);
220 	sctp_stream_outq_migrate(stream, NULL, outcnt);
221 	sched->sched_all(stream);
222 
223 	ret = sctp_stream_alloc_out(stream, outcnt, gfp);
224 	if (ret)
225 		goto out;
226 
227 	stream->outcnt = outcnt;
228 	for (i = 0; i < stream->outcnt; i++)
229 		SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
230 
231 	sched->init(stream);
232 
233 in:
234 	sctp_stream_interleave_init(stream);
235 	if (!incnt)
236 		goto out;
237 
238 	ret = sctp_stream_alloc_in(stream, incnt, gfp);
239 	if (ret) {
240 		sched->free(stream);
241 		fa_free(stream->out);
242 		stream->out = NULL;
243 		stream->outcnt = 0;
244 		goto out;
245 	}
246 
247 	stream->incnt = incnt;
248 
249 out:
250 	return ret;
251 }
252 
253 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid)
254 {
255 	struct sctp_stream_out_ext *soute;
256 
257 	soute = kzalloc(sizeof(*soute), GFP_KERNEL);
258 	if (!soute)
259 		return -ENOMEM;
260 	SCTP_SO(stream, sid)->ext = soute;
261 
262 	return sctp_sched_init_sid(stream, sid, GFP_KERNEL);
263 }
264 
265 void sctp_stream_free(struct sctp_stream *stream)
266 {
267 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
268 	int i;
269 
270 	sched->free(stream);
271 	for (i = 0; i < stream->outcnt; i++)
272 		kfree(SCTP_SO(stream, i)->ext);
273 	fa_free(stream->out);
274 	fa_free(stream->in);
275 }
276 
277 void sctp_stream_clear(struct sctp_stream *stream)
278 {
279 	int i;
280 
281 	for (i = 0; i < stream->outcnt; i++) {
282 		SCTP_SO(stream, i)->mid = 0;
283 		SCTP_SO(stream, i)->mid_uo = 0;
284 	}
285 
286 	for (i = 0; i < stream->incnt; i++)
287 		SCTP_SI(stream, i)->mid = 0;
288 }
289 
290 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
291 {
292 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
293 
294 	sched->unsched_all(stream);
295 	sctp_stream_outq_migrate(stream, new, new->outcnt);
296 	sctp_stream_free(stream);
297 
298 	stream->out = new->out;
299 	stream->in  = new->in;
300 	stream->outcnt = new->outcnt;
301 	stream->incnt  = new->incnt;
302 
303 	sched->sched_all(stream);
304 
305 	new->out = NULL;
306 	new->in  = NULL;
307 	new->outcnt = 0;
308 	new->incnt  = 0;
309 }
310 
311 static int sctp_send_reconf(struct sctp_association *asoc,
312 			    struct sctp_chunk *chunk)
313 {
314 	struct net *net = sock_net(asoc->base.sk);
315 	int retval = 0;
316 
317 	retval = sctp_primitive_RECONF(net, asoc, chunk);
318 	if (retval)
319 		sctp_chunk_free(chunk);
320 
321 	return retval;
322 }
323 
324 static bool sctp_stream_outq_is_empty(struct sctp_stream *stream,
325 				      __u16 str_nums, __be16 *str_list)
326 {
327 	struct sctp_association *asoc;
328 	__u16 i;
329 
330 	asoc = container_of(stream, struct sctp_association, stream);
331 	if (!asoc->outqueue.out_qlen)
332 		return true;
333 
334 	if (!str_nums)
335 		return false;
336 
337 	for (i = 0; i < str_nums; i++) {
338 		__u16 sid = ntohs(str_list[i]);
339 
340 		if (SCTP_SO(stream, sid)->ext &&
341 		    !list_empty(&SCTP_SO(stream, sid)->ext->outq))
342 			return false;
343 	}
344 
345 	return true;
346 }
347 
348 int sctp_send_reset_streams(struct sctp_association *asoc,
349 			    struct sctp_reset_streams *params)
350 {
351 	struct sctp_stream *stream = &asoc->stream;
352 	__u16 i, str_nums, *str_list;
353 	struct sctp_chunk *chunk;
354 	int retval = -EINVAL;
355 	__be16 *nstr_list;
356 	bool out, in;
357 
358 	if (!asoc->peer.reconf_capable ||
359 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ)) {
360 		retval = -ENOPROTOOPT;
361 		goto out;
362 	}
363 
364 	if (asoc->strreset_outstanding) {
365 		retval = -EINPROGRESS;
366 		goto out;
367 	}
368 
369 	out = params->srs_flags & SCTP_STREAM_RESET_OUTGOING;
370 	in  = params->srs_flags & SCTP_STREAM_RESET_INCOMING;
371 	if (!out && !in)
372 		goto out;
373 
374 	str_nums = params->srs_number_streams;
375 	str_list = params->srs_stream_list;
376 	if (str_nums) {
377 		int param_len = 0;
378 
379 		if (out) {
380 			for (i = 0; i < str_nums; i++)
381 				if (str_list[i] >= stream->outcnt)
382 					goto out;
383 
384 			param_len = str_nums * sizeof(__u16) +
385 				    sizeof(struct sctp_strreset_outreq);
386 		}
387 
388 		if (in) {
389 			for (i = 0; i < str_nums; i++)
390 				if (str_list[i] >= stream->incnt)
391 					goto out;
392 
393 			param_len += str_nums * sizeof(__u16) +
394 				     sizeof(struct sctp_strreset_inreq);
395 		}
396 
397 		if (param_len > SCTP_MAX_CHUNK_LEN -
398 				sizeof(struct sctp_reconf_chunk))
399 			goto out;
400 	}
401 
402 	nstr_list = kcalloc(str_nums, sizeof(__be16), GFP_KERNEL);
403 	if (!nstr_list) {
404 		retval = -ENOMEM;
405 		goto out;
406 	}
407 
408 	for (i = 0; i < str_nums; i++)
409 		nstr_list[i] = htons(str_list[i]);
410 
411 	if (out && !sctp_stream_outq_is_empty(stream, str_nums, nstr_list)) {
412 		retval = -EAGAIN;
413 		goto out;
414 	}
415 
416 	chunk = sctp_make_strreset_req(asoc, str_nums, nstr_list, out, in);
417 
418 	kfree(nstr_list);
419 
420 	if (!chunk) {
421 		retval = -ENOMEM;
422 		goto out;
423 	}
424 
425 	if (out) {
426 		if (str_nums)
427 			for (i = 0; i < str_nums; i++)
428 				SCTP_SO(stream, str_list[i])->state =
429 						       SCTP_STREAM_CLOSED;
430 		else
431 			for (i = 0; i < stream->outcnt; i++)
432 				SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
433 	}
434 
435 	asoc->strreset_chunk = chunk;
436 	sctp_chunk_hold(asoc->strreset_chunk);
437 
438 	retval = sctp_send_reconf(asoc, chunk);
439 	if (retval) {
440 		sctp_chunk_put(asoc->strreset_chunk);
441 		asoc->strreset_chunk = NULL;
442 		if (!out)
443 			goto out;
444 
445 		if (str_nums)
446 			for (i = 0; i < str_nums; i++)
447 				SCTP_SO(stream, str_list[i])->state =
448 						       SCTP_STREAM_OPEN;
449 		else
450 			for (i = 0; i < stream->outcnt; i++)
451 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
452 
453 		goto out;
454 	}
455 
456 	asoc->strreset_outstanding = out + in;
457 
458 out:
459 	return retval;
460 }
461 
462 int sctp_send_reset_assoc(struct sctp_association *asoc)
463 {
464 	struct sctp_stream *stream = &asoc->stream;
465 	struct sctp_chunk *chunk = NULL;
466 	int retval;
467 	__u16 i;
468 
469 	if (!asoc->peer.reconf_capable ||
470 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
471 		return -ENOPROTOOPT;
472 
473 	if (asoc->strreset_outstanding)
474 		return -EINPROGRESS;
475 
476 	if (!sctp_outq_is_empty(&asoc->outqueue))
477 		return -EAGAIN;
478 
479 	chunk = sctp_make_strreset_tsnreq(asoc);
480 	if (!chunk)
481 		return -ENOMEM;
482 
483 	/* Block further xmit of data until this request is completed */
484 	for (i = 0; i < stream->outcnt; i++)
485 		SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
486 
487 	asoc->strreset_chunk = chunk;
488 	sctp_chunk_hold(asoc->strreset_chunk);
489 
490 	retval = sctp_send_reconf(asoc, chunk);
491 	if (retval) {
492 		sctp_chunk_put(asoc->strreset_chunk);
493 		asoc->strreset_chunk = NULL;
494 
495 		for (i = 0; i < stream->outcnt; i++)
496 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
497 
498 		return retval;
499 	}
500 
501 	asoc->strreset_outstanding = 1;
502 
503 	return 0;
504 }
505 
506 int sctp_send_add_streams(struct sctp_association *asoc,
507 			  struct sctp_add_streams *params)
508 {
509 	struct sctp_stream *stream = &asoc->stream;
510 	struct sctp_chunk *chunk = NULL;
511 	int retval;
512 	__u32 outcnt, incnt;
513 	__u16 out, in;
514 
515 	if (!asoc->peer.reconf_capable ||
516 	    !(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ)) {
517 		retval = -ENOPROTOOPT;
518 		goto out;
519 	}
520 
521 	if (asoc->strreset_outstanding) {
522 		retval = -EINPROGRESS;
523 		goto out;
524 	}
525 
526 	out = params->sas_outstrms;
527 	in  = params->sas_instrms;
528 	outcnt = stream->outcnt + out;
529 	incnt = stream->incnt + in;
530 	if (outcnt > SCTP_MAX_STREAM || incnt > SCTP_MAX_STREAM ||
531 	    (!out && !in)) {
532 		retval = -EINVAL;
533 		goto out;
534 	}
535 
536 	if (out) {
537 		retval = sctp_stream_alloc_out(stream, outcnt, GFP_KERNEL);
538 		if (retval)
539 			goto out;
540 	}
541 
542 	chunk = sctp_make_strreset_addstrm(asoc, out, in);
543 	if (!chunk) {
544 		retval = -ENOMEM;
545 		goto out;
546 	}
547 
548 	asoc->strreset_chunk = chunk;
549 	sctp_chunk_hold(asoc->strreset_chunk);
550 
551 	retval = sctp_send_reconf(asoc, chunk);
552 	if (retval) {
553 		sctp_chunk_put(asoc->strreset_chunk);
554 		asoc->strreset_chunk = NULL;
555 		goto out;
556 	}
557 
558 	stream->outcnt = outcnt;
559 
560 	asoc->strreset_outstanding = !!out + !!in;
561 
562 out:
563 	return retval;
564 }
565 
566 static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param(
567 			struct sctp_association *asoc, __be32 resp_seq,
568 			__be16 type)
569 {
570 	struct sctp_chunk *chunk = asoc->strreset_chunk;
571 	struct sctp_reconf_chunk *hdr;
572 	union sctp_params param;
573 
574 	if (!chunk)
575 		return NULL;
576 
577 	hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
578 	sctp_walk_params(param, hdr, params) {
579 		/* sctp_strreset_tsnreq is actually the basic structure
580 		 * of all stream reconf params, so it's safe to use it
581 		 * to access request_seq.
582 		 */
583 		struct sctp_strreset_tsnreq *req = param.v;
584 
585 		if ((!resp_seq || req->request_seq == resp_seq) &&
586 		    (!type || type == req->param_hdr.type))
587 			return param.v;
588 	}
589 
590 	return NULL;
591 }
592 
593 static void sctp_update_strreset_result(struct sctp_association *asoc,
594 					__u32 result)
595 {
596 	asoc->strreset_result[1] = asoc->strreset_result[0];
597 	asoc->strreset_result[0] = result;
598 }
599 
600 struct sctp_chunk *sctp_process_strreset_outreq(
601 				struct sctp_association *asoc,
602 				union sctp_params param,
603 				struct sctp_ulpevent **evp)
604 {
605 	struct sctp_strreset_outreq *outreq = param.v;
606 	struct sctp_stream *stream = &asoc->stream;
607 	__u32 result = SCTP_STRRESET_DENIED;
608 	__be16 *str_p = NULL;
609 	__u32 request_seq;
610 	__u16 i, nums;
611 
612 	request_seq = ntohl(outreq->request_seq);
613 
614 	if (ntohl(outreq->send_reset_at_tsn) >
615 	    sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) {
616 		result = SCTP_STRRESET_IN_PROGRESS;
617 		goto err;
618 	}
619 
620 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
621 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
622 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
623 		goto err;
624 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
625 		i = asoc->strreset_inseq - request_seq - 1;
626 		result = asoc->strreset_result[i];
627 		goto err;
628 	}
629 	asoc->strreset_inseq++;
630 
631 	/* Check strreset_enable after inseq inc, as sender cannot tell
632 	 * the peer doesn't enable strreset after receiving response with
633 	 * result denied, as well as to keep consistent with bsd.
634 	 */
635 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
636 		goto out;
637 
638 	nums = (ntohs(param.p->length) - sizeof(*outreq)) / sizeof(__u16);
639 	str_p = outreq->list_of_streams;
640 	for (i = 0; i < nums; i++) {
641 		if (ntohs(str_p[i]) >= stream->incnt) {
642 			result = SCTP_STRRESET_ERR_WRONG_SSN;
643 			goto out;
644 		}
645 	}
646 
647 	if (asoc->strreset_chunk) {
648 		if (!sctp_chunk_lookup_strreset_param(
649 				asoc, outreq->response_seq,
650 				SCTP_PARAM_RESET_IN_REQUEST)) {
651 			/* same process with outstanding isn't 0 */
652 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
653 			goto out;
654 		}
655 
656 		asoc->strreset_outstanding--;
657 		asoc->strreset_outseq++;
658 
659 		if (!asoc->strreset_outstanding) {
660 			struct sctp_transport *t;
661 
662 			t = asoc->strreset_chunk->transport;
663 			if (del_timer(&t->reconf_timer))
664 				sctp_transport_put(t);
665 
666 			sctp_chunk_put(asoc->strreset_chunk);
667 			asoc->strreset_chunk = NULL;
668 		}
669 	}
670 
671 	if (nums)
672 		for (i = 0; i < nums; i++)
673 			SCTP_SI(stream, ntohs(str_p[i]))->mid = 0;
674 	else
675 		for (i = 0; i < stream->incnt; i++)
676 			SCTP_SI(stream, i)->mid = 0;
677 
678 	result = SCTP_STRRESET_PERFORMED;
679 
680 	*evp = sctp_ulpevent_make_stream_reset_event(asoc,
681 		SCTP_STREAM_RESET_INCOMING_SSN, nums, str_p, GFP_ATOMIC);
682 
683 out:
684 	sctp_update_strreset_result(asoc, result);
685 err:
686 	return sctp_make_strreset_resp(asoc, result, request_seq);
687 }
688 
689 struct sctp_chunk *sctp_process_strreset_inreq(
690 				struct sctp_association *asoc,
691 				union sctp_params param,
692 				struct sctp_ulpevent **evp)
693 {
694 	struct sctp_strreset_inreq *inreq = param.v;
695 	struct sctp_stream *stream = &asoc->stream;
696 	__u32 result = SCTP_STRRESET_DENIED;
697 	struct sctp_chunk *chunk = NULL;
698 	__u32 request_seq;
699 	__u16 i, nums;
700 	__be16 *str_p;
701 
702 	request_seq = ntohl(inreq->request_seq);
703 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
704 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
705 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
706 		goto err;
707 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
708 		i = asoc->strreset_inseq - request_seq - 1;
709 		result = asoc->strreset_result[i];
710 		if (result == SCTP_STRRESET_PERFORMED)
711 			return NULL;
712 		goto err;
713 	}
714 	asoc->strreset_inseq++;
715 
716 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
717 		goto out;
718 
719 	if (asoc->strreset_outstanding) {
720 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
721 		goto out;
722 	}
723 
724 	nums = (ntohs(param.p->length) - sizeof(*inreq)) / sizeof(__u16);
725 	str_p = inreq->list_of_streams;
726 	for (i = 0; i < nums; i++) {
727 		if (ntohs(str_p[i]) >= stream->outcnt) {
728 			result = SCTP_STRRESET_ERR_WRONG_SSN;
729 			goto out;
730 		}
731 	}
732 
733 	if (!sctp_stream_outq_is_empty(stream, nums, str_p)) {
734 		result = SCTP_STRRESET_IN_PROGRESS;
735 		asoc->strreset_inseq--;
736 		goto err;
737 	}
738 
739 	chunk = sctp_make_strreset_req(asoc, nums, str_p, 1, 0);
740 	if (!chunk)
741 		goto out;
742 
743 	if (nums)
744 		for (i = 0; i < nums; i++)
745 			SCTP_SO(stream, ntohs(str_p[i]))->state =
746 					       SCTP_STREAM_CLOSED;
747 	else
748 		for (i = 0; i < stream->outcnt; i++)
749 			SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
750 
751 	asoc->strreset_chunk = chunk;
752 	asoc->strreset_outstanding = 1;
753 	sctp_chunk_hold(asoc->strreset_chunk);
754 
755 	result = SCTP_STRRESET_PERFORMED;
756 
757 out:
758 	sctp_update_strreset_result(asoc, result);
759 err:
760 	if (!chunk)
761 		chunk =  sctp_make_strreset_resp(asoc, result, request_seq);
762 
763 	return chunk;
764 }
765 
766 struct sctp_chunk *sctp_process_strreset_tsnreq(
767 				struct sctp_association *asoc,
768 				union sctp_params param,
769 				struct sctp_ulpevent **evp)
770 {
771 	__u32 init_tsn = 0, next_tsn = 0, max_tsn_seen;
772 	struct sctp_strreset_tsnreq *tsnreq = param.v;
773 	struct sctp_stream *stream = &asoc->stream;
774 	__u32 result = SCTP_STRRESET_DENIED;
775 	__u32 request_seq;
776 	__u16 i;
777 
778 	request_seq = ntohl(tsnreq->request_seq);
779 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
780 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
781 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
782 		goto err;
783 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
784 		i = asoc->strreset_inseq - request_seq - 1;
785 		result = asoc->strreset_result[i];
786 		if (result == SCTP_STRRESET_PERFORMED) {
787 			next_tsn = asoc->ctsn_ack_point + 1;
788 			init_tsn =
789 				sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1;
790 		}
791 		goto err;
792 	}
793 
794 	if (!sctp_outq_is_empty(&asoc->outqueue)) {
795 		result = SCTP_STRRESET_IN_PROGRESS;
796 		goto err;
797 	}
798 
799 	asoc->strreset_inseq++;
800 
801 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
802 		goto out;
803 
804 	if (asoc->strreset_outstanding) {
805 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
806 		goto out;
807 	}
808 
809 	/* G4: The same processing as though a FWD-TSN chunk (as defined in
810 	 *     [RFC3758]) with all streams affected and a new cumulative TSN
811 	 *     ACK of the Receiver's Next TSN minus 1 were received MUST be
812 	 *     performed.
813 	 */
814 	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
815 	asoc->stream.si->report_ftsn(&asoc->ulpq, max_tsn_seen);
816 
817 	/* G1: Compute an appropriate value for the Receiver's Next TSN -- the
818 	 *     TSN that the peer should use to send the next DATA chunk.  The
819 	 *     value SHOULD be the smallest TSN not acknowledged by the
820 	 *     receiver of the request plus 2^31.
821 	 */
822 	init_tsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + (1 << 31);
823 	sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
824 			 init_tsn, GFP_ATOMIC);
825 
826 	/* G3: The same processing as though a SACK chunk with no gap report
827 	 *     and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
828 	 *     received MUST be performed.
829 	 */
830 	sctp_outq_free(&asoc->outqueue);
831 
832 	/* G2: Compute an appropriate value for the local endpoint's next TSN,
833 	 *     i.e., the next TSN assigned by the receiver of the SSN/TSN reset
834 	 *     chunk.  The value SHOULD be the highest TSN sent by the receiver
835 	 *     of the request plus 1.
836 	 */
837 	next_tsn = asoc->next_tsn;
838 	asoc->ctsn_ack_point = next_tsn - 1;
839 	asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
840 
841 	/* G5:  The next expected and outgoing SSNs MUST be reset to 0 for all
842 	 *      incoming and outgoing streams.
843 	 */
844 	for (i = 0; i < stream->outcnt; i++) {
845 		SCTP_SO(stream, i)->mid = 0;
846 		SCTP_SO(stream, i)->mid_uo = 0;
847 	}
848 	for (i = 0; i < stream->incnt; i++)
849 		SCTP_SI(stream, i)->mid = 0;
850 
851 	result = SCTP_STRRESET_PERFORMED;
852 
853 	*evp = sctp_ulpevent_make_assoc_reset_event(asoc, 0, init_tsn,
854 						    next_tsn, GFP_ATOMIC);
855 
856 out:
857 	sctp_update_strreset_result(asoc, result);
858 err:
859 	return sctp_make_strreset_tsnresp(asoc, result, request_seq,
860 					  next_tsn, init_tsn);
861 }
862 
863 struct sctp_chunk *sctp_process_strreset_addstrm_out(
864 				struct sctp_association *asoc,
865 				union sctp_params param,
866 				struct sctp_ulpevent **evp)
867 {
868 	struct sctp_strreset_addstrm *addstrm = param.v;
869 	struct sctp_stream *stream = &asoc->stream;
870 	__u32 result = SCTP_STRRESET_DENIED;
871 	__u32 request_seq, incnt;
872 	__u16 in, i;
873 
874 	request_seq = ntohl(addstrm->request_seq);
875 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
876 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
877 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
878 		goto err;
879 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
880 		i = asoc->strreset_inseq - request_seq - 1;
881 		result = asoc->strreset_result[i];
882 		goto err;
883 	}
884 	asoc->strreset_inseq++;
885 
886 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
887 		goto out;
888 
889 	in = ntohs(addstrm->number_of_streams);
890 	incnt = stream->incnt + in;
891 	if (!in || incnt > SCTP_MAX_STREAM)
892 		goto out;
893 
894 	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
895 		goto out;
896 
897 	if (asoc->strreset_chunk) {
898 		if (!sctp_chunk_lookup_strreset_param(
899 			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
900 			/* same process with outstanding isn't 0 */
901 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
902 			goto out;
903 		}
904 
905 		asoc->strreset_outstanding--;
906 		asoc->strreset_outseq++;
907 
908 		if (!asoc->strreset_outstanding) {
909 			struct sctp_transport *t;
910 
911 			t = asoc->strreset_chunk->transport;
912 			if (del_timer(&t->reconf_timer))
913 				sctp_transport_put(t);
914 
915 			sctp_chunk_put(asoc->strreset_chunk);
916 			asoc->strreset_chunk = NULL;
917 		}
918 	}
919 
920 	stream->incnt = incnt;
921 
922 	result = SCTP_STRRESET_PERFORMED;
923 
924 	*evp = sctp_ulpevent_make_stream_change_event(asoc,
925 		0, ntohs(addstrm->number_of_streams), 0, GFP_ATOMIC);
926 
927 out:
928 	sctp_update_strreset_result(asoc, result);
929 err:
930 	return sctp_make_strreset_resp(asoc, result, request_seq);
931 }
932 
933 struct sctp_chunk *sctp_process_strreset_addstrm_in(
934 				struct sctp_association *asoc,
935 				union sctp_params param,
936 				struct sctp_ulpevent **evp)
937 {
938 	struct sctp_strreset_addstrm *addstrm = param.v;
939 	struct sctp_stream *stream = &asoc->stream;
940 	__u32 result = SCTP_STRRESET_DENIED;
941 	struct sctp_chunk *chunk = NULL;
942 	__u32 request_seq, outcnt;
943 	__u16 out, i;
944 	int ret;
945 
946 	request_seq = ntohl(addstrm->request_seq);
947 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
948 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
949 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
950 		goto err;
951 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
952 		i = asoc->strreset_inseq - request_seq - 1;
953 		result = asoc->strreset_result[i];
954 		if (result == SCTP_STRRESET_PERFORMED)
955 			return NULL;
956 		goto err;
957 	}
958 	asoc->strreset_inseq++;
959 
960 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
961 		goto out;
962 
963 	if (asoc->strreset_outstanding) {
964 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
965 		goto out;
966 	}
967 
968 	out = ntohs(addstrm->number_of_streams);
969 	outcnt = stream->outcnt + out;
970 	if (!out || outcnt > SCTP_MAX_STREAM)
971 		goto out;
972 
973 	ret = sctp_stream_alloc_out(stream, outcnt, GFP_ATOMIC);
974 	if (ret)
975 		goto out;
976 
977 	chunk = sctp_make_strreset_addstrm(asoc, out, 0);
978 	if (!chunk)
979 		goto out;
980 
981 	asoc->strreset_chunk = chunk;
982 	asoc->strreset_outstanding = 1;
983 	sctp_chunk_hold(asoc->strreset_chunk);
984 
985 	stream->outcnt = outcnt;
986 
987 	result = SCTP_STRRESET_PERFORMED;
988 
989 out:
990 	sctp_update_strreset_result(asoc, result);
991 err:
992 	if (!chunk)
993 		chunk = sctp_make_strreset_resp(asoc, result, request_seq);
994 
995 	return chunk;
996 }
997 
998 struct sctp_chunk *sctp_process_strreset_resp(
999 				struct sctp_association *asoc,
1000 				union sctp_params param,
1001 				struct sctp_ulpevent **evp)
1002 {
1003 	struct sctp_stream *stream = &asoc->stream;
1004 	struct sctp_strreset_resp *resp = param.v;
1005 	struct sctp_transport *t;
1006 	__u16 i, nums, flags = 0;
1007 	struct sctp_paramhdr *req;
1008 	__u32 result;
1009 
1010 	req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0);
1011 	if (!req)
1012 		return NULL;
1013 
1014 	result = ntohl(resp->result);
1015 	if (result != SCTP_STRRESET_PERFORMED) {
1016 		/* if in progress, do nothing but retransmit */
1017 		if (result == SCTP_STRRESET_IN_PROGRESS)
1018 			return NULL;
1019 		else if (result == SCTP_STRRESET_DENIED)
1020 			flags = SCTP_STREAM_RESET_DENIED;
1021 		else
1022 			flags = SCTP_STREAM_RESET_FAILED;
1023 	}
1024 
1025 	if (req->type == SCTP_PARAM_RESET_OUT_REQUEST) {
1026 		struct sctp_strreset_outreq *outreq;
1027 		__be16 *str_p;
1028 
1029 		outreq = (struct sctp_strreset_outreq *)req;
1030 		str_p = outreq->list_of_streams;
1031 		nums = (ntohs(outreq->param_hdr.length) - sizeof(*outreq)) /
1032 		       sizeof(__u16);
1033 
1034 		if (result == SCTP_STRRESET_PERFORMED) {
1035 			struct sctp_stream_out *sout;
1036 			if (nums) {
1037 				for (i = 0; i < nums; i++) {
1038 					sout = SCTP_SO(stream, ntohs(str_p[i]));
1039 					sout->mid = 0;
1040 					sout->mid_uo = 0;
1041 				}
1042 			} else {
1043 				for (i = 0; i < stream->outcnt; i++) {
1044 					sout = SCTP_SO(stream, i);
1045 					sout->mid = 0;
1046 					sout->mid_uo = 0;
1047 				}
1048 			}
1049 		}
1050 
1051 		flags |= SCTP_STREAM_RESET_OUTGOING_SSN;
1052 
1053 		for (i = 0; i < stream->outcnt; i++)
1054 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1055 
1056 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
1057 			nums, str_p, GFP_ATOMIC);
1058 	} else if (req->type == SCTP_PARAM_RESET_IN_REQUEST) {
1059 		struct sctp_strreset_inreq *inreq;
1060 		__be16 *str_p;
1061 
1062 		/* if the result is performed, it's impossible for inreq */
1063 		if (result == SCTP_STRRESET_PERFORMED)
1064 			return NULL;
1065 
1066 		inreq = (struct sctp_strreset_inreq *)req;
1067 		str_p = inreq->list_of_streams;
1068 		nums = (ntohs(inreq->param_hdr.length) - sizeof(*inreq)) /
1069 		       sizeof(__u16);
1070 
1071 		flags |= SCTP_STREAM_RESET_INCOMING_SSN;
1072 
1073 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
1074 			nums, str_p, GFP_ATOMIC);
1075 	} else if (req->type == SCTP_PARAM_RESET_TSN_REQUEST) {
1076 		struct sctp_strreset_resptsn *resptsn;
1077 		__u32 stsn, rtsn;
1078 
1079 		/* check for resptsn, as sctp_verify_reconf didn't do it*/
1080 		if (ntohs(param.p->length) != sizeof(*resptsn))
1081 			return NULL;
1082 
1083 		resptsn = (struct sctp_strreset_resptsn *)resp;
1084 		stsn = ntohl(resptsn->senders_next_tsn);
1085 		rtsn = ntohl(resptsn->receivers_next_tsn);
1086 
1087 		if (result == SCTP_STRRESET_PERFORMED) {
1088 			__u32 mtsn = sctp_tsnmap_get_max_tsn_seen(
1089 						&asoc->peer.tsn_map);
1090 			LIST_HEAD(temp);
1091 
1092 			asoc->stream.si->report_ftsn(&asoc->ulpq, mtsn);
1093 
1094 			sctp_tsnmap_init(&asoc->peer.tsn_map,
1095 					 SCTP_TSN_MAP_INITIAL,
1096 					 stsn, GFP_ATOMIC);
1097 
1098 			/* Clean up sacked and abandoned queues only. As the
1099 			 * out_chunk_list may not be empty, splice it to temp,
1100 			 * then get it back after sctp_outq_free is done.
1101 			 */
1102 			list_splice_init(&asoc->outqueue.out_chunk_list, &temp);
1103 			sctp_outq_free(&asoc->outqueue);
1104 			list_splice_init(&temp, &asoc->outqueue.out_chunk_list);
1105 
1106 			asoc->next_tsn = rtsn;
1107 			asoc->ctsn_ack_point = asoc->next_tsn - 1;
1108 			asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1109 
1110 			for (i = 0; i < stream->outcnt; i++) {
1111 				SCTP_SO(stream, i)->mid = 0;
1112 				SCTP_SO(stream, i)->mid_uo = 0;
1113 			}
1114 			for (i = 0; i < stream->incnt; i++)
1115 				SCTP_SI(stream, i)->mid = 0;
1116 		}
1117 
1118 		for (i = 0; i < stream->outcnt; i++)
1119 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1120 
1121 		*evp = sctp_ulpevent_make_assoc_reset_event(asoc, flags,
1122 			stsn, rtsn, GFP_ATOMIC);
1123 	} else if (req->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS) {
1124 		struct sctp_strreset_addstrm *addstrm;
1125 		__u16 number;
1126 
1127 		addstrm = (struct sctp_strreset_addstrm *)req;
1128 		nums = ntohs(addstrm->number_of_streams);
1129 		number = stream->outcnt - nums;
1130 
1131 		if (result == SCTP_STRRESET_PERFORMED)
1132 			for (i = number; i < stream->outcnt; i++)
1133 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1134 		else
1135 			stream->outcnt = number;
1136 
1137 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1138 			0, nums, GFP_ATOMIC);
1139 	} else if (req->type == SCTP_PARAM_RESET_ADD_IN_STREAMS) {
1140 		struct sctp_strreset_addstrm *addstrm;
1141 
1142 		/* if the result is performed, it's impossible for addstrm in
1143 		 * request.
1144 		 */
1145 		if (result == SCTP_STRRESET_PERFORMED)
1146 			return NULL;
1147 
1148 		addstrm = (struct sctp_strreset_addstrm *)req;
1149 		nums = ntohs(addstrm->number_of_streams);
1150 
1151 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1152 			nums, 0, GFP_ATOMIC);
1153 	}
1154 
1155 	asoc->strreset_outstanding--;
1156 	asoc->strreset_outseq++;
1157 
1158 	/* remove everything for this reconf request */
1159 	if (!asoc->strreset_outstanding) {
1160 		t = asoc->strreset_chunk->transport;
1161 		if (del_timer(&t->reconf_timer))
1162 			sctp_transport_put(t);
1163 
1164 		sctp_chunk_put(asoc->strreset_chunk);
1165 		asoc->strreset_chunk = NULL;
1166 	}
1167 
1168 	return NULL;
1169 }
1170