xref: /openbmc/linux/net/sctp/stream.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3  * (C) Copyright IBM Corp. 2001, 2004
4  * Copyright (c) 1999-2000 Cisco, Inc.
5  * Copyright (c) 1999-2001 Motorola, Inc.
6  * Copyright (c) 2001 Intel Corp.
7  *
8  * This file is part of the SCTP kernel implementation
9  *
10  * This file contains sctp stream maniuplation primitives and helpers.
11  *
12  * Please send any bug reports or fixes you make to the
13  * email address(es):
14  *    lksctp developers <linux-sctp@vger.kernel.org>
15  *
16  * Written or modified by:
17  *    Xin Long <lucien.xin@gmail.com>
18  */
19 
20 #include <linux/list.h>
21 #include <net/sctp/sctp.h>
22 #include <net/sctp/sm.h>
23 #include <net/sctp/stream_sched.h>
24 
25 static void sctp_stream_shrink_out(struct sctp_stream *stream, __u16 outcnt)
26 {
27 	struct sctp_association *asoc;
28 	struct sctp_chunk *ch, *temp;
29 	struct sctp_outq *outq;
30 
31 	asoc = container_of(stream, struct sctp_association, stream);
32 	outq = &asoc->outqueue;
33 
34 	list_for_each_entry_safe(ch, temp, &outq->out_chunk_list, list) {
35 		__u16 sid = sctp_chunk_stream_no(ch);
36 
37 		if (sid < outcnt)
38 			continue;
39 
40 		sctp_sched_dequeue_common(outq, ch);
41 		/* No need to call dequeue_done here because
42 		 * the chunks are not scheduled by now.
43 		 */
44 
45 		/* Mark as failed send. */
46 		sctp_chunk_fail(ch, (__force __u32)SCTP_ERROR_INV_STRM);
47 		if (asoc->peer.prsctp_capable &&
48 		    SCTP_PR_PRIO_ENABLED(ch->sinfo.sinfo_flags))
49 			asoc->sent_cnt_removable--;
50 
51 		sctp_chunk_free(ch);
52 	}
53 }
54 
55 /* Migrates chunks from stream queues to new stream queues if needed,
56  * but not across associations. Also, removes those chunks to streams
57  * higher than the new max.
58  */
59 static void sctp_stream_outq_migrate(struct sctp_stream *stream,
60 				     struct sctp_stream *new, __u16 outcnt)
61 {
62 	int i;
63 
64 	if (stream->outcnt > outcnt)
65 		sctp_stream_shrink_out(stream, outcnt);
66 
67 	if (new) {
68 		/* Here we actually move the old ext stuff into the new
69 		 * buffer, because we want to keep it. Then
70 		 * sctp_stream_update will swap ->out pointers.
71 		 */
72 		for (i = 0; i < outcnt; i++) {
73 			kfree(SCTP_SO(new, i)->ext);
74 			SCTP_SO(new, i)->ext = SCTP_SO(stream, i)->ext;
75 			SCTP_SO(stream, i)->ext = NULL;
76 		}
77 	}
78 
79 	for (i = outcnt; i < stream->outcnt; i++) {
80 		kfree(SCTP_SO(stream, i)->ext);
81 		SCTP_SO(stream, i)->ext = NULL;
82 	}
83 }
84 
85 static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
86 				 gfp_t gfp)
87 {
88 	int ret;
89 
90 	if (outcnt <= stream->outcnt)
91 		goto out;
92 
93 	ret = genradix_prealloc(&stream->out, outcnt, gfp);
94 	if (ret)
95 		return ret;
96 
97 out:
98 	stream->outcnt = outcnt;
99 	return 0;
100 }
101 
102 static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
103 				gfp_t gfp)
104 {
105 	int ret;
106 
107 	if (incnt <= stream->incnt)
108 		goto out;
109 
110 	ret = genradix_prealloc(&stream->in, incnt, gfp);
111 	if (ret)
112 		return ret;
113 
114 out:
115 	stream->incnt = incnt;
116 	return 0;
117 }
118 
119 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
120 		     gfp_t gfp)
121 {
122 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
123 	int i, ret = 0;
124 
125 	gfp |= __GFP_NOWARN;
126 
127 	/* Initial stream->out size may be very big, so free it and alloc
128 	 * a new one with new outcnt to save memory if needed.
129 	 */
130 	if (outcnt == stream->outcnt)
131 		goto handle_in;
132 
133 	/* Filter out chunks queued on streams that won't exist anymore */
134 	sched->unsched_all(stream);
135 	sctp_stream_outq_migrate(stream, NULL, outcnt);
136 	sched->sched_all(stream);
137 
138 	ret = sctp_stream_alloc_out(stream, outcnt, gfp);
139 	if (ret)
140 		goto out_err;
141 
142 	for (i = 0; i < stream->outcnt; i++)
143 		SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
144 
145 handle_in:
146 	sctp_stream_interleave_init(stream);
147 	if (!incnt)
148 		goto out;
149 
150 	ret = sctp_stream_alloc_in(stream, incnt, gfp);
151 	if (ret)
152 		goto in_err;
153 
154 	goto out;
155 
156 in_err:
157 	sched->free(stream);
158 	genradix_free(&stream->in);
159 out_err:
160 	genradix_free(&stream->out);
161 	stream->outcnt = 0;
162 out:
163 	return ret;
164 }
165 
166 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid)
167 {
168 	struct sctp_stream_out_ext *soute;
169 	int ret;
170 
171 	soute = kzalloc(sizeof(*soute), GFP_KERNEL);
172 	if (!soute)
173 		return -ENOMEM;
174 	SCTP_SO(stream, sid)->ext = soute;
175 
176 	ret = sctp_sched_init_sid(stream, sid, GFP_KERNEL);
177 	if (ret) {
178 		kfree(SCTP_SO(stream, sid)->ext);
179 		SCTP_SO(stream, sid)->ext = NULL;
180 	}
181 
182 	return ret;
183 }
184 
185 void sctp_stream_free(struct sctp_stream *stream)
186 {
187 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
188 	int i;
189 
190 	sched->free(stream);
191 	for (i = 0; i < stream->outcnt; i++)
192 		kfree(SCTP_SO(stream, i)->ext);
193 	genradix_free(&stream->out);
194 	genradix_free(&stream->in);
195 }
196 
197 void sctp_stream_clear(struct sctp_stream *stream)
198 {
199 	int i;
200 
201 	for (i = 0; i < stream->outcnt; i++) {
202 		SCTP_SO(stream, i)->mid = 0;
203 		SCTP_SO(stream, i)->mid_uo = 0;
204 	}
205 
206 	for (i = 0; i < stream->incnt; i++)
207 		SCTP_SI(stream, i)->mid = 0;
208 }
209 
210 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
211 {
212 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
213 
214 	sched->unsched_all(stream);
215 	sctp_stream_outq_migrate(stream, new, new->outcnt);
216 	sctp_stream_free(stream);
217 
218 	stream->out = new->out;
219 	stream->in  = new->in;
220 	stream->outcnt = new->outcnt;
221 	stream->incnt  = new->incnt;
222 
223 	sched->sched_all(stream);
224 
225 	new->out.tree.root = NULL;
226 	new->in.tree.root  = NULL;
227 	new->outcnt = 0;
228 	new->incnt  = 0;
229 }
230 
231 static int sctp_send_reconf(struct sctp_association *asoc,
232 			    struct sctp_chunk *chunk)
233 {
234 	int retval = 0;
235 
236 	retval = sctp_primitive_RECONF(asoc->base.net, asoc, chunk);
237 	if (retval)
238 		sctp_chunk_free(chunk);
239 
240 	return retval;
241 }
242 
243 static bool sctp_stream_outq_is_empty(struct sctp_stream *stream,
244 				      __u16 str_nums, __be16 *str_list)
245 {
246 	struct sctp_association *asoc;
247 	__u16 i;
248 
249 	asoc = container_of(stream, struct sctp_association, stream);
250 	if (!asoc->outqueue.out_qlen)
251 		return true;
252 
253 	if (!str_nums)
254 		return false;
255 
256 	for (i = 0; i < str_nums; i++) {
257 		__u16 sid = ntohs(str_list[i]);
258 
259 		if (SCTP_SO(stream, sid)->ext &&
260 		    !list_empty(&SCTP_SO(stream, sid)->ext->outq))
261 			return false;
262 	}
263 
264 	return true;
265 }
266 
267 int sctp_send_reset_streams(struct sctp_association *asoc,
268 			    struct sctp_reset_streams *params)
269 {
270 	struct sctp_stream *stream = &asoc->stream;
271 	__u16 i, str_nums, *str_list;
272 	struct sctp_chunk *chunk;
273 	int retval = -EINVAL;
274 	__be16 *nstr_list;
275 	bool out, in;
276 
277 	if (!asoc->peer.reconf_capable ||
278 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ)) {
279 		retval = -ENOPROTOOPT;
280 		goto out;
281 	}
282 
283 	if (asoc->strreset_outstanding) {
284 		retval = -EINPROGRESS;
285 		goto out;
286 	}
287 
288 	out = params->srs_flags & SCTP_STREAM_RESET_OUTGOING;
289 	in  = params->srs_flags & SCTP_STREAM_RESET_INCOMING;
290 	if (!out && !in)
291 		goto out;
292 
293 	str_nums = params->srs_number_streams;
294 	str_list = params->srs_stream_list;
295 	if (str_nums) {
296 		int param_len = 0;
297 
298 		if (out) {
299 			for (i = 0; i < str_nums; i++)
300 				if (str_list[i] >= stream->outcnt)
301 					goto out;
302 
303 			param_len = str_nums * sizeof(__u16) +
304 				    sizeof(struct sctp_strreset_outreq);
305 		}
306 
307 		if (in) {
308 			for (i = 0; i < str_nums; i++)
309 				if (str_list[i] >= stream->incnt)
310 					goto out;
311 
312 			param_len += str_nums * sizeof(__u16) +
313 				     sizeof(struct sctp_strreset_inreq);
314 		}
315 
316 		if (param_len > SCTP_MAX_CHUNK_LEN -
317 				sizeof(struct sctp_reconf_chunk))
318 			goto out;
319 	}
320 
321 	nstr_list = kcalloc(str_nums, sizeof(__be16), GFP_KERNEL);
322 	if (!nstr_list) {
323 		retval = -ENOMEM;
324 		goto out;
325 	}
326 
327 	for (i = 0; i < str_nums; i++)
328 		nstr_list[i] = htons(str_list[i]);
329 
330 	if (out && !sctp_stream_outq_is_empty(stream, str_nums, nstr_list)) {
331 		kfree(nstr_list);
332 		retval = -EAGAIN;
333 		goto out;
334 	}
335 
336 	chunk = sctp_make_strreset_req(asoc, str_nums, nstr_list, out, in);
337 
338 	kfree(nstr_list);
339 
340 	if (!chunk) {
341 		retval = -ENOMEM;
342 		goto out;
343 	}
344 
345 	if (out) {
346 		if (str_nums)
347 			for (i = 0; i < str_nums; i++)
348 				SCTP_SO(stream, str_list[i])->state =
349 						       SCTP_STREAM_CLOSED;
350 		else
351 			for (i = 0; i < stream->outcnt; i++)
352 				SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
353 	}
354 
355 	asoc->strreset_chunk = chunk;
356 	sctp_chunk_hold(asoc->strreset_chunk);
357 
358 	retval = sctp_send_reconf(asoc, chunk);
359 	if (retval) {
360 		sctp_chunk_put(asoc->strreset_chunk);
361 		asoc->strreset_chunk = NULL;
362 		if (!out)
363 			goto out;
364 
365 		if (str_nums)
366 			for (i = 0; i < str_nums; i++)
367 				SCTP_SO(stream, str_list[i])->state =
368 						       SCTP_STREAM_OPEN;
369 		else
370 			for (i = 0; i < stream->outcnt; i++)
371 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
372 
373 		goto out;
374 	}
375 
376 	asoc->strreset_outstanding = out + in;
377 
378 out:
379 	return retval;
380 }
381 
382 int sctp_send_reset_assoc(struct sctp_association *asoc)
383 {
384 	struct sctp_stream *stream = &asoc->stream;
385 	struct sctp_chunk *chunk = NULL;
386 	int retval;
387 	__u16 i;
388 
389 	if (!asoc->peer.reconf_capable ||
390 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
391 		return -ENOPROTOOPT;
392 
393 	if (asoc->strreset_outstanding)
394 		return -EINPROGRESS;
395 
396 	if (!sctp_outq_is_empty(&asoc->outqueue))
397 		return -EAGAIN;
398 
399 	chunk = sctp_make_strreset_tsnreq(asoc);
400 	if (!chunk)
401 		return -ENOMEM;
402 
403 	/* Block further xmit of data until this request is completed */
404 	for (i = 0; i < stream->outcnt; i++)
405 		SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
406 
407 	asoc->strreset_chunk = chunk;
408 	sctp_chunk_hold(asoc->strreset_chunk);
409 
410 	retval = sctp_send_reconf(asoc, chunk);
411 	if (retval) {
412 		sctp_chunk_put(asoc->strreset_chunk);
413 		asoc->strreset_chunk = NULL;
414 
415 		for (i = 0; i < stream->outcnt; i++)
416 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
417 
418 		return retval;
419 	}
420 
421 	asoc->strreset_outstanding = 1;
422 
423 	return 0;
424 }
425 
426 int sctp_send_add_streams(struct sctp_association *asoc,
427 			  struct sctp_add_streams *params)
428 {
429 	struct sctp_stream *stream = &asoc->stream;
430 	struct sctp_chunk *chunk = NULL;
431 	int retval;
432 	__u32 outcnt, incnt;
433 	__u16 out, in;
434 
435 	if (!asoc->peer.reconf_capable ||
436 	    !(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ)) {
437 		retval = -ENOPROTOOPT;
438 		goto out;
439 	}
440 
441 	if (asoc->strreset_outstanding) {
442 		retval = -EINPROGRESS;
443 		goto out;
444 	}
445 
446 	out = params->sas_outstrms;
447 	in  = params->sas_instrms;
448 	outcnt = stream->outcnt + out;
449 	incnt = stream->incnt + in;
450 	if (outcnt > SCTP_MAX_STREAM || incnt > SCTP_MAX_STREAM ||
451 	    (!out && !in)) {
452 		retval = -EINVAL;
453 		goto out;
454 	}
455 
456 	if (out) {
457 		retval = sctp_stream_alloc_out(stream, outcnt, GFP_KERNEL);
458 		if (retval)
459 			goto out;
460 	}
461 
462 	chunk = sctp_make_strreset_addstrm(asoc, out, in);
463 	if (!chunk) {
464 		retval = -ENOMEM;
465 		goto out;
466 	}
467 
468 	asoc->strreset_chunk = chunk;
469 	sctp_chunk_hold(asoc->strreset_chunk);
470 
471 	retval = sctp_send_reconf(asoc, chunk);
472 	if (retval) {
473 		sctp_chunk_put(asoc->strreset_chunk);
474 		asoc->strreset_chunk = NULL;
475 		goto out;
476 	}
477 
478 	asoc->strreset_outstanding = !!out + !!in;
479 
480 out:
481 	return retval;
482 }
483 
484 static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param(
485 			struct sctp_association *asoc, __be32 resp_seq,
486 			__be16 type)
487 {
488 	struct sctp_chunk *chunk = asoc->strreset_chunk;
489 	struct sctp_reconf_chunk *hdr;
490 	union sctp_params param;
491 
492 	if (!chunk)
493 		return NULL;
494 
495 	hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
496 	sctp_walk_params(param, hdr, params) {
497 		/* sctp_strreset_tsnreq is actually the basic structure
498 		 * of all stream reconf params, so it's safe to use it
499 		 * to access request_seq.
500 		 */
501 		struct sctp_strreset_tsnreq *req = param.v;
502 
503 		if ((!resp_seq || req->request_seq == resp_seq) &&
504 		    (!type || type == req->param_hdr.type))
505 			return param.v;
506 	}
507 
508 	return NULL;
509 }
510 
511 static void sctp_update_strreset_result(struct sctp_association *asoc,
512 					__u32 result)
513 {
514 	asoc->strreset_result[1] = asoc->strreset_result[0];
515 	asoc->strreset_result[0] = result;
516 }
517 
518 struct sctp_chunk *sctp_process_strreset_outreq(
519 				struct sctp_association *asoc,
520 				union sctp_params param,
521 				struct sctp_ulpevent **evp)
522 {
523 	struct sctp_strreset_outreq *outreq = param.v;
524 	struct sctp_stream *stream = &asoc->stream;
525 	__u32 result = SCTP_STRRESET_DENIED;
526 	__be16 *str_p = NULL;
527 	__u32 request_seq;
528 	__u16 i, nums;
529 
530 	request_seq = ntohl(outreq->request_seq);
531 
532 	if (ntohl(outreq->send_reset_at_tsn) >
533 	    sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) {
534 		result = SCTP_STRRESET_IN_PROGRESS;
535 		goto err;
536 	}
537 
538 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
539 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
540 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
541 		goto err;
542 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
543 		i = asoc->strreset_inseq - request_seq - 1;
544 		result = asoc->strreset_result[i];
545 		goto err;
546 	}
547 	asoc->strreset_inseq++;
548 
549 	/* Check strreset_enable after inseq inc, as sender cannot tell
550 	 * the peer doesn't enable strreset after receiving response with
551 	 * result denied, as well as to keep consistent with bsd.
552 	 */
553 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
554 		goto out;
555 
556 	nums = (ntohs(param.p->length) - sizeof(*outreq)) / sizeof(__u16);
557 	str_p = outreq->list_of_streams;
558 	for (i = 0; i < nums; i++) {
559 		if (ntohs(str_p[i]) >= stream->incnt) {
560 			result = SCTP_STRRESET_ERR_WRONG_SSN;
561 			goto out;
562 		}
563 	}
564 
565 	if (asoc->strreset_chunk) {
566 		if (!sctp_chunk_lookup_strreset_param(
567 				asoc, outreq->response_seq,
568 				SCTP_PARAM_RESET_IN_REQUEST)) {
569 			/* same process with outstanding isn't 0 */
570 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
571 			goto out;
572 		}
573 
574 		asoc->strreset_outstanding--;
575 		asoc->strreset_outseq++;
576 
577 		if (!asoc->strreset_outstanding) {
578 			struct sctp_transport *t;
579 
580 			t = asoc->strreset_chunk->transport;
581 			if (del_timer(&t->reconf_timer))
582 				sctp_transport_put(t);
583 
584 			sctp_chunk_put(asoc->strreset_chunk);
585 			asoc->strreset_chunk = NULL;
586 		}
587 	}
588 
589 	if (nums)
590 		for (i = 0; i < nums; i++)
591 			SCTP_SI(stream, ntohs(str_p[i]))->mid = 0;
592 	else
593 		for (i = 0; i < stream->incnt; i++)
594 			SCTP_SI(stream, i)->mid = 0;
595 
596 	result = SCTP_STRRESET_PERFORMED;
597 
598 	*evp = sctp_ulpevent_make_stream_reset_event(asoc,
599 		SCTP_STREAM_RESET_INCOMING_SSN, nums, str_p, GFP_ATOMIC);
600 
601 out:
602 	sctp_update_strreset_result(asoc, result);
603 err:
604 	return sctp_make_strreset_resp(asoc, result, request_seq);
605 }
606 
607 struct sctp_chunk *sctp_process_strreset_inreq(
608 				struct sctp_association *asoc,
609 				union sctp_params param,
610 				struct sctp_ulpevent **evp)
611 {
612 	struct sctp_strreset_inreq *inreq = param.v;
613 	struct sctp_stream *stream = &asoc->stream;
614 	__u32 result = SCTP_STRRESET_DENIED;
615 	struct sctp_chunk *chunk = NULL;
616 	__u32 request_seq;
617 	__u16 i, nums;
618 	__be16 *str_p;
619 
620 	request_seq = ntohl(inreq->request_seq);
621 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
622 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
623 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
624 		goto err;
625 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
626 		i = asoc->strreset_inseq - request_seq - 1;
627 		result = asoc->strreset_result[i];
628 		if (result == SCTP_STRRESET_PERFORMED)
629 			return NULL;
630 		goto err;
631 	}
632 	asoc->strreset_inseq++;
633 
634 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
635 		goto out;
636 
637 	if (asoc->strreset_outstanding) {
638 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
639 		goto out;
640 	}
641 
642 	nums = (ntohs(param.p->length) - sizeof(*inreq)) / sizeof(__u16);
643 	str_p = inreq->list_of_streams;
644 	for (i = 0; i < nums; i++) {
645 		if (ntohs(str_p[i]) >= stream->outcnt) {
646 			result = SCTP_STRRESET_ERR_WRONG_SSN;
647 			goto out;
648 		}
649 	}
650 
651 	if (!sctp_stream_outq_is_empty(stream, nums, str_p)) {
652 		result = SCTP_STRRESET_IN_PROGRESS;
653 		asoc->strreset_inseq--;
654 		goto err;
655 	}
656 
657 	chunk = sctp_make_strreset_req(asoc, nums, str_p, 1, 0);
658 	if (!chunk)
659 		goto out;
660 
661 	if (nums)
662 		for (i = 0; i < nums; i++)
663 			SCTP_SO(stream, ntohs(str_p[i]))->state =
664 					       SCTP_STREAM_CLOSED;
665 	else
666 		for (i = 0; i < stream->outcnt; i++)
667 			SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
668 
669 	asoc->strreset_chunk = chunk;
670 	asoc->strreset_outstanding = 1;
671 	sctp_chunk_hold(asoc->strreset_chunk);
672 
673 	result = SCTP_STRRESET_PERFORMED;
674 
675 out:
676 	sctp_update_strreset_result(asoc, result);
677 err:
678 	if (!chunk)
679 		chunk =  sctp_make_strreset_resp(asoc, result, request_seq);
680 
681 	return chunk;
682 }
683 
684 struct sctp_chunk *sctp_process_strreset_tsnreq(
685 				struct sctp_association *asoc,
686 				union sctp_params param,
687 				struct sctp_ulpevent **evp)
688 {
689 	__u32 init_tsn = 0, next_tsn = 0, max_tsn_seen;
690 	struct sctp_strreset_tsnreq *tsnreq = param.v;
691 	struct sctp_stream *stream = &asoc->stream;
692 	__u32 result = SCTP_STRRESET_DENIED;
693 	__u32 request_seq;
694 	__u16 i;
695 
696 	request_seq = ntohl(tsnreq->request_seq);
697 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
698 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
699 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
700 		goto err;
701 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
702 		i = asoc->strreset_inseq - request_seq - 1;
703 		result = asoc->strreset_result[i];
704 		if (result == SCTP_STRRESET_PERFORMED) {
705 			next_tsn = asoc->ctsn_ack_point + 1;
706 			init_tsn =
707 				sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1;
708 		}
709 		goto err;
710 	}
711 
712 	if (!sctp_outq_is_empty(&asoc->outqueue)) {
713 		result = SCTP_STRRESET_IN_PROGRESS;
714 		goto err;
715 	}
716 
717 	asoc->strreset_inseq++;
718 
719 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
720 		goto out;
721 
722 	if (asoc->strreset_outstanding) {
723 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
724 		goto out;
725 	}
726 
727 	/* G4: The same processing as though a FWD-TSN chunk (as defined in
728 	 *     [RFC3758]) with all streams affected and a new cumulative TSN
729 	 *     ACK of the Receiver's Next TSN minus 1 were received MUST be
730 	 *     performed.
731 	 */
732 	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
733 	asoc->stream.si->report_ftsn(&asoc->ulpq, max_tsn_seen);
734 
735 	/* G1: Compute an appropriate value for the Receiver's Next TSN -- the
736 	 *     TSN that the peer should use to send the next DATA chunk.  The
737 	 *     value SHOULD be the smallest TSN not acknowledged by the
738 	 *     receiver of the request plus 2^31.
739 	 */
740 	init_tsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + (1 << 31);
741 	sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
742 			 init_tsn, GFP_ATOMIC);
743 
744 	/* G3: The same processing as though a SACK chunk with no gap report
745 	 *     and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
746 	 *     received MUST be performed.
747 	 */
748 	sctp_outq_free(&asoc->outqueue);
749 
750 	/* G2: Compute an appropriate value for the local endpoint's next TSN,
751 	 *     i.e., the next TSN assigned by the receiver of the SSN/TSN reset
752 	 *     chunk.  The value SHOULD be the highest TSN sent by the receiver
753 	 *     of the request plus 1.
754 	 */
755 	next_tsn = asoc->next_tsn;
756 	asoc->ctsn_ack_point = next_tsn - 1;
757 	asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
758 
759 	/* G5:  The next expected and outgoing SSNs MUST be reset to 0 for all
760 	 *      incoming and outgoing streams.
761 	 */
762 	for (i = 0; i < stream->outcnt; i++) {
763 		SCTP_SO(stream, i)->mid = 0;
764 		SCTP_SO(stream, i)->mid_uo = 0;
765 	}
766 	for (i = 0; i < stream->incnt; i++)
767 		SCTP_SI(stream, i)->mid = 0;
768 
769 	result = SCTP_STRRESET_PERFORMED;
770 
771 	*evp = sctp_ulpevent_make_assoc_reset_event(asoc, 0, init_tsn,
772 						    next_tsn, GFP_ATOMIC);
773 
774 out:
775 	sctp_update_strreset_result(asoc, result);
776 err:
777 	return sctp_make_strreset_tsnresp(asoc, result, request_seq,
778 					  next_tsn, init_tsn);
779 }
780 
781 struct sctp_chunk *sctp_process_strreset_addstrm_out(
782 				struct sctp_association *asoc,
783 				union sctp_params param,
784 				struct sctp_ulpevent **evp)
785 {
786 	struct sctp_strreset_addstrm *addstrm = param.v;
787 	struct sctp_stream *stream = &asoc->stream;
788 	__u32 result = SCTP_STRRESET_DENIED;
789 	__u32 request_seq, incnt;
790 	__u16 in, i;
791 
792 	request_seq = ntohl(addstrm->request_seq);
793 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
794 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
795 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
796 		goto err;
797 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
798 		i = asoc->strreset_inseq - request_seq - 1;
799 		result = asoc->strreset_result[i];
800 		goto err;
801 	}
802 	asoc->strreset_inseq++;
803 
804 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
805 		goto out;
806 
807 	in = ntohs(addstrm->number_of_streams);
808 	incnt = stream->incnt + in;
809 	if (!in || incnt > SCTP_MAX_STREAM)
810 		goto out;
811 
812 	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
813 		goto out;
814 
815 	if (asoc->strreset_chunk) {
816 		if (!sctp_chunk_lookup_strreset_param(
817 			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
818 			/* same process with outstanding isn't 0 */
819 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
820 			goto out;
821 		}
822 
823 		asoc->strreset_outstanding--;
824 		asoc->strreset_outseq++;
825 
826 		if (!asoc->strreset_outstanding) {
827 			struct sctp_transport *t;
828 
829 			t = asoc->strreset_chunk->transport;
830 			if (del_timer(&t->reconf_timer))
831 				sctp_transport_put(t);
832 
833 			sctp_chunk_put(asoc->strreset_chunk);
834 			asoc->strreset_chunk = NULL;
835 		}
836 	}
837 
838 	stream->incnt = incnt;
839 
840 	result = SCTP_STRRESET_PERFORMED;
841 
842 	*evp = sctp_ulpevent_make_stream_change_event(asoc,
843 		0, ntohs(addstrm->number_of_streams), 0, GFP_ATOMIC);
844 
845 out:
846 	sctp_update_strreset_result(asoc, result);
847 err:
848 	return sctp_make_strreset_resp(asoc, result, request_seq);
849 }
850 
851 struct sctp_chunk *sctp_process_strreset_addstrm_in(
852 				struct sctp_association *asoc,
853 				union sctp_params param,
854 				struct sctp_ulpevent **evp)
855 {
856 	struct sctp_strreset_addstrm *addstrm = param.v;
857 	struct sctp_stream *stream = &asoc->stream;
858 	__u32 result = SCTP_STRRESET_DENIED;
859 	struct sctp_chunk *chunk = NULL;
860 	__u32 request_seq, outcnt;
861 	__u16 out, i;
862 	int ret;
863 
864 	request_seq = ntohl(addstrm->request_seq);
865 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
866 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
867 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
868 		goto err;
869 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
870 		i = asoc->strreset_inseq - request_seq - 1;
871 		result = asoc->strreset_result[i];
872 		if (result == SCTP_STRRESET_PERFORMED)
873 			return NULL;
874 		goto err;
875 	}
876 	asoc->strreset_inseq++;
877 
878 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
879 		goto out;
880 
881 	if (asoc->strreset_outstanding) {
882 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
883 		goto out;
884 	}
885 
886 	out = ntohs(addstrm->number_of_streams);
887 	outcnt = stream->outcnt + out;
888 	if (!out || outcnt > SCTP_MAX_STREAM)
889 		goto out;
890 
891 	ret = sctp_stream_alloc_out(stream, outcnt, GFP_ATOMIC);
892 	if (ret)
893 		goto out;
894 
895 	chunk = sctp_make_strreset_addstrm(asoc, out, 0);
896 	if (!chunk)
897 		goto out;
898 
899 	asoc->strreset_chunk = chunk;
900 	asoc->strreset_outstanding = 1;
901 	sctp_chunk_hold(asoc->strreset_chunk);
902 
903 	stream->outcnt = outcnt;
904 
905 	result = SCTP_STRRESET_PERFORMED;
906 
907 out:
908 	sctp_update_strreset_result(asoc, result);
909 err:
910 	if (!chunk)
911 		chunk = sctp_make_strreset_resp(asoc, result, request_seq);
912 
913 	return chunk;
914 }
915 
916 struct sctp_chunk *sctp_process_strreset_resp(
917 				struct sctp_association *asoc,
918 				union sctp_params param,
919 				struct sctp_ulpevent **evp)
920 {
921 	struct sctp_stream *stream = &asoc->stream;
922 	struct sctp_strreset_resp *resp = param.v;
923 	struct sctp_transport *t;
924 	__u16 i, nums, flags = 0;
925 	struct sctp_paramhdr *req;
926 	__u32 result;
927 
928 	req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0);
929 	if (!req)
930 		return NULL;
931 
932 	result = ntohl(resp->result);
933 	if (result != SCTP_STRRESET_PERFORMED) {
934 		/* if in progress, do nothing but retransmit */
935 		if (result == SCTP_STRRESET_IN_PROGRESS)
936 			return NULL;
937 		else if (result == SCTP_STRRESET_DENIED)
938 			flags = SCTP_STREAM_RESET_DENIED;
939 		else
940 			flags = SCTP_STREAM_RESET_FAILED;
941 	}
942 
943 	if (req->type == SCTP_PARAM_RESET_OUT_REQUEST) {
944 		struct sctp_strreset_outreq *outreq;
945 		__be16 *str_p;
946 
947 		outreq = (struct sctp_strreset_outreq *)req;
948 		str_p = outreq->list_of_streams;
949 		nums = (ntohs(outreq->param_hdr.length) - sizeof(*outreq)) /
950 		       sizeof(__u16);
951 
952 		if (result == SCTP_STRRESET_PERFORMED) {
953 			struct sctp_stream_out *sout;
954 			if (nums) {
955 				for (i = 0; i < nums; i++) {
956 					sout = SCTP_SO(stream, ntohs(str_p[i]));
957 					sout->mid = 0;
958 					sout->mid_uo = 0;
959 				}
960 			} else {
961 				for (i = 0; i < stream->outcnt; i++) {
962 					sout = SCTP_SO(stream, i);
963 					sout->mid = 0;
964 					sout->mid_uo = 0;
965 				}
966 			}
967 		}
968 
969 		flags |= SCTP_STREAM_RESET_OUTGOING_SSN;
970 
971 		for (i = 0; i < stream->outcnt; i++)
972 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
973 
974 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
975 			nums, str_p, GFP_ATOMIC);
976 	} else if (req->type == SCTP_PARAM_RESET_IN_REQUEST) {
977 		struct sctp_strreset_inreq *inreq;
978 		__be16 *str_p;
979 
980 		/* if the result is performed, it's impossible for inreq */
981 		if (result == SCTP_STRRESET_PERFORMED)
982 			return NULL;
983 
984 		inreq = (struct sctp_strreset_inreq *)req;
985 		str_p = inreq->list_of_streams;
986 		nums = (ntohs(inreq->param_hdr.length) - sizeof(*inreq)) /
987 		       sizeof(__u16);
988 
989 		flags |= SCTP_STREAM_RESET_INCOMING_SSN;
990 
991 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
992 			nums, str_p, GFP_ATOMIC);
993 	} else if (req->type == SCTP_PARAM_RESET_TSN_REQUEST) {
994 		struct sctp_strreset_resptsn *resptsn;
995 		__u32 stsn, rtsn;
996 
997 		/* check for resptsn, as sctp_verify_reconf didn't do it*/
998 		if (ntohs(param.p->length) != sizeof(*resptsn))
999 			return NULL;
1000 
1001 		resptsn = (struct sctp_strreset_resptsn *)resp;
1002 		stsn = ntohl(resptsn->senders_next_tsn);
1003 		rtsn = ntohl(resptsn->receivers_next_tsn);
1004 
1005 		if (result == SCTP_STRRESET_PERFORMED) {
1006 			__u32 mtsn = sctp_tsnmap_get_max_tsn_seen(
1007 						&asoc->peer.tsn_map);
1008 			LIST_HEAD(temp);
1009 
1010 			asoc->stream.si->report_ftsn(&asoc->ulpq, mtsn);
1011 
1012 			sctp_tsnmap_init(&asoc->peer.tsn_map,
1013 					 SCTP_TSN_MAP_INITIAL,
1014 					 stsn, GFP_ATOMIC);
1015 
1016 			/* Clean up sacked and abandoned queues only. As the
1017 			 * out_chunk_list may not be empty, splice it to temp,
1018 			 * then get it back after sctp_outq_free is done.
1019 			 */
1020 			list_splice_init(&asoc->outqueue.out_chunk_list, &temp);
1021 			sctp_outq_free(&asoc->outqueue);
1022 			list_splice_init(&temp, &asoc->outqueue.out_chunk_list);
1023 
1024 			asoc->next_tsn = rtsn;
1025 			asoc->ctsn_ack_point = asoc->next_tsn - 1;
1026 			asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1027 
1028 			for (i = 0; i < stream->outcnt; i++) {
1029 				SCTP_SO(stream, i)->mid = 0;
1030 				SCTP_SO(stream, i)->mid_uo = 0;
1031 			}
1032 			for (i = 0; i < stream->incnt; i++)
1033 				SCTP_SI(stream, i)->mid = 0;
1034 		}
1035 
1036 		for (i = 0; i < stream->outcnt; i++)
1037 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1038 
1039 		*evp = sctp_ulpevent_make_assoc_reset_event(asoc, flags,
1040 			stsn, rtsn, GFP_ATOMIC);
1041 	} else if (req->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS) {
1042 		struct sctp_strreset_addstrm *addstrm;
1043 		__u16 number;
1044 
1045 		addstrm = (struct sctp_strreset_addstrm *)req;
1046 		nums = ntohs(addstrm->number_of_streams);
1047 		number = stream->outcnt - nums;
1048 
1049 		if (result == SCTP_STRRESET_PERFORMED) {
1050 			for (i = number; i < stream->outcnt; i++)
1051 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1052 		} else {
1053 			sctp_stream_shrink_out(stream, number);
1054 			stream->outcnt = number;
1055 		}
1056 
1057 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1058 			0, nums, GFP_ATOMIC);
1059 	} else if (req->type == SCTP_PARAM_RESET_ADD_IN_STREAMS) {
1060 		struct sctp_strreset_addstrm *addstrm;
1061 
1062 		/* if the result is performed, it's impossible for addstrm in
1063 		 * request.
1064 		 */
1065 		if (result == SCTP_STRRESET_PERFORMED)
1066 			return NULL;
1067 
1068 		addstrm = (struct sctp_strreset_addstrm *)req;
1069 		nums = ntohs(addstrm->number_of_streams);
1070 
1071 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1072 			nums, 0, GFP_ATOMIC);
1073 	}
1074 
1075 	asoc->strreset_outstanding--;
1076 	asoc->strreset_outseq++;
1077 
1078 	/* remove everything for this reconf request */
1079 	if (!asoc->strreset_outstanding) {
1080 		t = asoc->strreset_chunk->transport;
1081 		if (del_timer(&t->reconf_timer))
1082 			sctp_transport_put(t);
1083 
1084 		sctp_chunk_put(asoc->strreset_chunk);
1085 		asoc->strreset_chunk = NULL;
1086 	}
1087 
1088 	return NULL;
1089 }
1090