xref: /openbmc/linux/net/sctp/stream.c (revision 9a6b55ac)
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 /* Migrates chunks from stream queues to new stream queues if needed,
26  * but not across associations. Also, removes those chunks to streams
27  * higher than the new max.
28  */
29 static void sctp_stream_outq_migrate(struct sctp_stream *stream,
30 				     struct sctp_stream *new, __u16 outcnt)
31 {
32 	struct sctp_association *asoc;
33 	struct sctp_chunk *ch, *temp;
34 	struct sctp_outq *outq;
35 	int i;
36 
37 	asoc = container_of(stream, struct sctp_association, stream);
38 	outq = &asoc->outqueue;
39 
40 	list_for_each_entry_safe(ch, temp, &outq->out_chunk_list, list) {
41 		__u16 sid = sctp_chunk_stream_no(ch);
42 
43 		if (sid < outcnt)
44 			continue;
45 
46 		sctp_sched_dequeue_common(outq, ch);
47 		/* No need to call dequeue_done here because
48 		 * the chunks are not scheduled by now.
49 		 */
50 
51 		/* Mark as failed send. */
52 		sctp_chunk_fail(ch, (__force __u32)SCTP_ERROR_INV_STRM);
53 		if (asoc->peer.prsctp_capable &&
54 		    SCTP_PR_PRIO_ENABLED(ch->sinfo.sinfo_flags))
55 			asoc->sent_cnt_removable--;
56 
57 		sctp_chunk_free(ch);
58 	}
59 
60 	if (new) {
61 		/* Here we actually move the old ext stuff into the new
62 		 * buffer, because we want to keep it. Then
63 		 * sctp_stream_update will swap ->out pointers.
64 		 */
65 		for (i = 0; i < outcnt; i++) {
66 			kfree(SCTP_SO(new, i)->ext);
67 			SCTP_SO(new, i)->ext = SCTP_SO(stream, i)->ext;
68 			SCTP_SO(stream, i)->ext = NULL;
69 		}
70 	}
71 
72 	for (i = outcnt; i < stream->outcnt; i++) {
73 		kfree(SCTP_SO(stream, i)->ext);
74 		SCTP_SO(stream, i)->ext = NULL;
75 	}
76 }
77 
78 static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
79 				 gfp_t gfp)
80 {
81 	int ret;
82 
83 	if (outcnt <= stream->outcnt)
84 		return 0;
85 
86 	ret = genradix_prealloc(&stream->out, outcnt, gfp);
87 	if (ret)
88 		return ret;
89 
90 	stream->outcnt = outcnt;
91 	return 0;
92 }
93 
94 static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
95 				gfp_t gfp)
96 {
97 	int ret;
98 
99 	if (incnt <= stream->incnt)
100 		return 0;
101 
102 	ret = genradix_prealloc(&stream->in, incnt, gfp);
103 	if (ret)
104 		return ret;
105 
106 	stream->incnt = incnt;
107 	return 0;
108 }
109 
110 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
111 		     gfp_t gfp)
112 {
113 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
114 	int i, ret = 0;
115 
116 	gfp |= __GFP_NOWARN;
117 
118 	/* Initial stream->out size may be very big, so free it and alloc
119 	 * a new one with new outcnt to save memory if needed.
120 	 */
121 	if (outcnt == stream->outcnt)
122 		goto handle_in;
123 
124 	/* Filter out chunks queued on streams that won't exist anymore */
125 	sched->unsched_all(stream);
126 	sctp_stream_outq_migrate(stream, NULL, outcnt);
127 	sched->sched_all(stream);
128 
129 	ret = sctp_stream_alloc_out(stream, outcnt, gfp);
130 	if (ret)
131 		goto out_err;
132 
133 	for (i = 0; i < stream->outcnt; i++)
134 		SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
135 
136 handle_in:
137 	sctp_stream_interleave_init(stream);
138 	if (!incnt)
139 		goto out;
140 
141 	ret = sctp_stream_alloc_in(stream, incnt, gfp);
142 	if (ret)
143 		goto in_err;
144 
145 	goto out;
146 
147 in_err:
148 	sched->free(stream);
149 	genradix_free(&stream->in);
150 out_err:
151 	genradix_free(&stream->out);
152 	stream->outcnt = 0;
153 out:
154 	return ret;
155 }
156 
157 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid)
158 {
159 	struct sctp_stream_out_ext *soute;
160 	int ret;
161 
162 	soute = kzalloc(sizeof(*soute), GFP_KERNEL);
163 	if (!soute)
164 		return -ENOMEM;
165 	SCTP_SO(stream, sid)->ext = soute;
166 
167 	ret = sctp_sched_init_sid(stream, sid, GFP_KERNEL);
168 	if (ret) {
169 		kfree(SCTP_SO(stream, sid)->ext);
170 		SCTP_SO(stream, sid)->ext = NULL;
171 	}
172 
173 	return ret;
174 }
175 
176 void sctp_stream_free(struct sctp_stream *stream)
177 {
178 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
179 	int i;
180 
181 	sched->free(stream);
182 	for (i = 0; i < stream->outcnt; i++)
183 		kfree(SCTP_SO(stream, i)->ext);
184 	genradix_free(&stream->out);
185 	genradix_free(&stream->in);
186 }
187 
188 void sctp_stream_clear(struct sctp_stream *stream)
189 {
190 	int i;
191 
192 	for (i = 0; i < stream->outcnt; i++) {
193 		SCTP_SO(stream, i)->mid = 0;
194 		SCTP_SO(stream, i)->mid_uo = 0;
195 	}
196 
197 	for (i = 0; i < stream->incnt; i++)
198 		SCTP_SI(stream, i)->mid = 0;
199 }
200 
201 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
202 {
203 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
204 
205 	sched->unsched_all(stream);
206 	sctp_stream_outq_migrate(stream, new, new->outcnt);
207 	sctp_stream_free(stream);
208 
209 	stream->out = new->out;
210 	stream->in  = new->in;
211 	stream->outcnt = new->outcnt;
212 	stream->incnt  = new->incnt;
213 
214 	sched->sched_all(stream);
215 
216 	new->out.tree.root = NULL;
217 	new->in.tree.root  = NULL;
218 	new->outcnt = 0;
219 	new->incnt  = 0;
220 }
221 
222 static int sctp_send_reconf(struct sctp_association *asoc,
223 			    struct sctp_chunk *chunk)
224 {
225 	struct net *net = sock_net(asoc->base.sk);
226 	int retval = 0;
227 
228 	retval = sctp_primitive_RECONF(net, asoc, chunk);
229 	if (retval)
230 		sctp_chunk_free(chunk);
231 
232 	return retval;
233 }
234 
235 static bool sctp_stream_outq_is_empty(struct sctp_stream *stream,
236 				      __u16 str_nums, __be16 *str_list)
237 {
238 	struct sctp_association *asoc;
239 	__u16 i;
240 
241 	asoc = container_of(stream, struct sctp_association, stream);
242 	if (!asoc->outqueue.out_qlen)
243 		return true;
244 
245 	if (!str_nums)
246 		return false;
247 
248 	for (i = 0; i < str_nums; i++) {
249 		__u16 sid = ntohs(str_list[i]);
250 
251 		if (SCTP_SO(stream, sid)->ext &&
252 		    !list_empty(&SCTP_SO(stream, sid)->ext->outq))
253 			return false;
254 	}
255 
256 	return true;
257 }
258 
259 int sctp_send_reset_streams(struct sctp_association *asoc,
260 			    struct sctp_reset_streams *params)
261 {
262 	struct sctp_stream *stream = &asoc->stream;
263 	__u16 i, str_nums, *str_list;
264 	struct sctp_chunk *chunk;
265 	int retval = -EINVAL;
266 	__be16 *nstr_list;
267 	bool out, in;
268 
269 	if (!asoc->peer.reconf_capable ||
270 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ)) {
271 		retval = -ENOPROTOOPT;
272 		goto out;
273 	}
274 
275 	if (asoc->strreset_outstanding) {
276 		retval = -EINPROGRESS;
277 		goto out;
278 	}
279 
280 	out = params->srs_flags & SCTP_STREAM_RESET_OUTGOING;
281 	in  = params->srs_flags & SCTP_STREAM_RESET_INCOMING;
282 	if (!out && !in)
283 		goto out;
284 
285 	str_nums = params->srs_number_streams;
286 	str_list = params->srs_stream_list;
287 	if (str_nums) {
288 		int param_len = 0;
289 
290 		if (out) {
291 			for (i = 0; i < str_nums; i++)
292 				if (str_list[i] >= stream->outcnt)
293 					goto out;
294 
295 			param_len = str_nums * sizeof(__u16) +
296 				    sizeof(struct sctp_strreset_outreq);
297 		}
298 
299 		if (in) {
300 			for (i = 0; i < str_nums; i++)
301 				if (str_list[i] >= stream->incnt)
302 					goto out;
303 
304 			param_len += str_nums * sizeof(__u16) +
305 				     sizeof(struct sctp_strreset_inreq);
306 		}
307 
308 		if (param_len > SCTP_MAX_CHUNK_LEN -
309 				sizeof(struct sctp_reconf_chunk))
310 			goto out;
311 	}
312 
313 	nstr_list = kcalloc(str_nums, sizeof(__be16), GFP_KERNEL);
314 	if (!nstr_list) {
315 		retval = -ENOMEM;
316 		goto out;
317 	}
318 
319 	for (i = 0; i < str_nums; i++)
320 		nstr_list[i] = htons(str_list[i]);
321 
322 	if (out && !sctp_stream_outq_is_empty(stream, str_nums, nstr_list)) {
323 		kfree(nstr_list);
324 		retval = -EAGAIN;
325 		goto out;
326 	}
327 
328 	chunk = sctp_make_strreset_req(asoc, str_nums, nstr_list, out, in);
329 
330 	kfree(nstr_list);
331 
332 	if (!chunk) {
333 		retval = -ENOMEM;
334 		goto out;
335 	}
336 
337 	if (out) {
338 		if (str_nums)
339 			for (i = 0; i < str_nums; i++)
340 				SCTP_SO(stream, str_list[i])->state =
341 						       SCTP_STREAM_CLOSED;
342 		else
343 			for (i = 0; i < stream->outcnt; i++)
344 				SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
345 	}
346 
347 	asoc->strreset_chunk = chunk;
348 	sctp_chunk_hold(asoc->strreset_chunk);
349 
350 	retval = sctp_send_reconf(asoc, chunk);
351 	if (retval) {
352 		sctp_chunk_put(asoc->strreset_chunk);
353 		asoc->strreset_chunk = NULL;
354 		if (!out)
355 			goto out;
356 
357 		if (str_nums)
358 			for (i = 0; i < str_nums; i++)
359 				SCTP_SO(stream, str_list[i])->state =
360 						       SCTP_STREAM_OPEN;
361 		else
362 			for (i = 0; i < stream->outcnt; i++)
363 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
364 
365 		goto out;
366 	}
367 
368 	asoc->strreset_outstanding = out + in;
369 
370 out:
371 	return retval;
372 }
373 
374 int sctp_send_reset_assoc(struct sctp_association *asoc)
375 {
376 	struct sctp_stream *stream = &asoc->stream;
377 	struct sctp_chunk *chunk = NULL;
378 	int retval;
379 	__u16 i;
380 
381 	if (!asoc->peer.reconf_capable ||
382 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
383 		return -ENOPROTOOPT;
384 
385 	if (asoc->strreset_outstanding)
386 		return -EINPROGRESS;
387 
388 	if (!sctp_outq_is_empty(&asoc->outqueue))
389 		return -EAGAIN;
390 
391 	chunk = sctp_make_strreset_tsnreq(asoc);
392 	if (!chunk)
393 		return -ENOMEM;
394 
395 	/* Block further xmit of data until this request is completed */
396 	for (i = 0; i < stream->outcnt; i++)
397 		SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
398 
399 	asoc->strreset_chunk = chunk;
400 	sctp_chunk_hold(asoc->strreset_chunk);
401 
402 	retval = sctp_send_reconf(asoc, chunk);
403 	if (retval) {
404 		sctp_chunk_put(asoc->strreset_chunk);
405 		asoc->strreset_chunk = NULL;
406 
407 		for (i = 0; i < stream->outcnt; i++)
408 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
409 
410 		return retval;
411 	}
412 
413 	asoc->strreset_outstanding = 1;
414 
415 	return 0;
416 }
417 
418 int sctp_send_add_streams(struct sctp_association *asoc,
419 			  struct sctp_add_streams *params)
420 {
421 	struct sctp_stream *stream = &asoc->stream;
422 	struct sctp_chunk *chunk = NULL;
423 	int retval;
424 	__u32 outcnt, incnt;
425 	__u16 out, in;
426 
427 	if (!asoc->peer.reconf_capable ||
428 	    !(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ)) {
429 		retval = -ENOPROTOOPT;
430 		goto out;
431 	}
432 
433 	if (asoc->strreset_outstanding) {
434 		retval = -EINPROGRESS;
435 		goto out;
436 	}
437 
438 	out = params->sas_outstrms;
439 	in  = params->sas_instrms;
440 	outcnt = stream->outcnt + out;
441 	incnt = stream->incnt + in;
442 	if (outcnt > SCTP_MAX_STREAM || incnt > SCTP_MAX_STREAM ||
443 	    (!out && !in)) {
444 		retval = -EINVAL;
445 		goto out;
446 	}
447 
448 	if (out) {
449 		retval = sctp_stream_alloc_out(stream, outcnt, GFP_KERNEL);
450 		if (retval)
451 			goto out;
452 	}
453 
454 	chunk = sctp_make_strreset_addstrm(asoc, out, in);
455 	if (!chunk) {
456 		retval = -ENOMEM;
457 		goto out;
458 	}
459 
460 	asoc->strreset_chunk = chunk;
461 	sctp_chunk_hold(asoc->strreset_chunk);
462 
463 	retval = sctp_send_reconf(asoc, chunk);
464 	if (retval) {
465 		sctp_chunk_put(asoc->strreset_chunk);
466 		asoc->strreset_chunk = NULL;
467 		goto out;
468 	}
469 
470 	asoc->strreset_outstanding = !!out + !!in;
471 
472 out:
473 	return retval;
474 }
475 
476 static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param(
477 			struct sctp_association *asoc, __be32 resp_seq,
478 			__be16 type)
479 {
480 	struct sctp_chunk *chunk = asoc->strreset_chunk;
481 	struct sctp_reconf_chunk *hdr;
482 	union sctp_params param;
483 
484 	if (!chunk)
485 		return NULL;
486 
487 	hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
488 	sctp_walk_params(param, hdr, params) {
489 		/* sctp_strreset_tsnreq is actually the basic structure
490 		 * of all stream reconf params, so it's safe to use it
491 		 * to access request_seq.
492 		 */
493 		struct sctp_strreset_tsnreq *req = param.v;
494 
495 		if ((!resp_seq || req->request_seq == resp_seq) &&
496 		    (!type || type == req->param_hdr.type))
497 			return param.v;
498 	}
499 
500 	return NULL;
501 }
502 
503 static void sctp_update_strreset_result(struct sctp_association *asoc,
504 					__u32 result)
505 {
506 	asoc->strreset_result[1] = asoc->strreset_result[0];
507 	asoc->strreset_result[0] = result;
508 }
509 
510 struct sctp_chunk *sctp_process_strreset_outreq(
511 				struct sctp_association *asoc,
512 				union sctp_params param,
513 				struct sctp_ulpevent **evp)
514 {
515 	struct sctp_strreset_outreq *outreq = param.v;
516 	struct sctp_stream *stream = &asoc->stream;
517 	__u32 result = SCTP_STRRESET_DENIED;
518 	__be16 *str_p = NULL;
519 	__u32 request_seq;
520 	__u16 i, nums;
521 
522 	request_seq = ntohl(outreq->request_seq);
523 
524 	if (ntohl(outreq->send_reset_at_tsn) >
525 	    sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) {
526 		result = SCTP_STRRESET_IN_PROGRESS;
527 		goto err;
528 	}
529 
530 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
531 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
532 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
533 		goto err;
534 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
535 		i = asoc->strreset_inseq - request_seq - 1;
536 		result = asoc->strreset_result[i];
537 		goto err;
538 	}
539 	asoc->strreset_inseq++;
540 
541 	/* Check strreset_enable after inseq inc, as sender cannot tell
542 	 * the peer doesn't enable strreset after receiving response with
543 	 * result denied, as well as to keep consistent with bsd.
544 	 */
545 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
546 		goto out;
547 
548 	nums = (ntohs(param.p->length) - sizeof(*outreq)) / sizeof(__u16);
549 	str_p = outreq->list_of_streams;
550 	for (i = 0; i < nums; i++) {
551 		if (ntohs(str_p[i]) >= stream->incnt) {
552 			result = SCTP_STRRESET_ERR_WRONG_SSN;
553 			goto out;
554 		}
555 	}
556 
557 	if (asoc->strreset_chunk) {
558 		if (!sctp_chunk_lookup_strreset_param(
559 				asoc, outreq->response_seq,
560 				SCTP_PARAM_RESET_IN_REQUEST)) {
561 			/* same process with outstanding isn't 0 */
562 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
563 			goto out;
564 		}
565 
566 		asoc->strreset_outstanding--;
567 		asoc->strreset_outseq++;
568 
569 		if (!asoc->strreset_outstanding) {
570 			struct sctp_transport *t;
571 
572 			t = asoc->strreset_chunk->transport;
573 			if (del_timer(&t->reconf_timer))
574 				sctp_transport_put(t);
575 
576 			sctp_chunk_put(asoc->strreset_chunk);
577 			asoc->strreset_chunk = NULL;
578 		}
579 	}
580 
581 	if (nums)
582 		for (i = 0; i < nums; i++)
583 			SCTP_SI(stream, ntohs(str_p[i]))->mid = 0;
584 	else
585 		for (i = 0; i < stream->incnt; i++)
586 			SCTP_SI(stream, i)->mid = 0;
587 
588 	result = SCTP_STRRESET_PERFORMED;
589 
590 	*evp = sctp_ulpevent_make_stream_reset_event(asoc,
591 		SCTP_STREAM_RESET_INCOMING_SSN, nums, str_p, GFP_ATOMIC);
592 
593 out:
594 	sctp_update_strreset_result(asoc, result);
595 err:
596 	return sctp_make_strreset_resp(asoc, result, request_seq);
597 }
598 
599 struct sctp_chunk *sctp_process_strreset_inreq(
600 				struct sctp_association *asoc,
601 				union sctp_params param,
602 				struct sctp_ulpevent **evp)
603 {
604 	struct sctp_strreset_inreq *inreq = param.v;
605 	struct sctp_stream *stream = &asoc->stream;
606 	__u32 result = SCTP_STRRESET_DENIED;
607 	struct sctp_chunk *chunk = NULL;
608 	__u32 request_seq;
609 	__u16 i, nums;
610 	__be16 *str_p;
611 
612 	request_seq = ntohl(inreq->request_seq);
613 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
614 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
615 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
616 		goto err;
617 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
618 		i = asoc->strreset_inseq - request_seq - 1;
619 		result = asoc->strreset_result[i];
620 		if (result == SCTP_STRRESET_PERFORMED)
621 			return NULL;
622 		goto err;
623 	}
624 	asoc->strreset_inseq++;
625 
626 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
627 		goto out;
628 
629 	if (asoc->strreset_outstanding) {
630 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
631 		goto out;
632 	}
633 
634 	nums = (ntohs(param.p->length) - sizeof(*inreq)) / sizeof(__u16);
635 	str_p = inreq->list_of_streams;
636 	for (i = 0; i < nums; i++) {
637 		if (ntohs(str_p[i]) >= stream->outcnt) {
638 			result = SCTP_STRRESET_ERR_WRONG_SSN;
639 			goto out;
640 		}
641 	}
642 
643 	if (!sctp_stream_outq_is_empty(stream, nums, str_p)) {
644 		result = SCTP_STRRESET_IN_PROGRESS;
645 		asoc->strreset_inseq--;
646 		goto err;
647 	}
648 
649 	chunk = sctp_make_strreset_req(asoc, nums, str_p, 1, 0);
650 	if (!chunk)
651 		goto out;
652 
653 	if (nums)
654 		for (i = 0; i < nums; i++)
655 			SCTP_SO(stream, ntohs(str_p[i]))->state =
656 					       SCTP_STREAM_CLOSED;
657 	else
658 		for (i = 0; i < stream->outcnt; i++)
659 			SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
660 
661 	asoc->strreset_chunk = chunk;
662 	asoc->strreset_outstanding = 1;
663 	sctp_chunk_hold(asoc->strreset_chunk);
664 
665 	result = SCTP_STRRESET_PERFORMED;
666 
667 out:
668 	sctp_update_strreset_result(asoc, result);
669 err:
670 	if (!chunk)
671 		chunk =  sctp_make_strreset_resp(asoc, result, request_seq);
672 
673 	return chunk;
674 }
675 
676 struct sctp_chunk *sctp_process_strreset_tsnreq(
677 				struct sctp_association *asoc,
678 				union sctp_params param,
679 				struct sctp_ulpevent **evp)
680 {
681 	__u32 init_tsn = 0, next_tsn = 0, max_tsn_seen;
682 	struct sctp_strreset_tsnreq *tsnreq = param.v;
683 	struct sctp_stream *stream = &asoc->stream;
684 	__u32 result = SCTP_STRRESET_DENIED;
685 	__u32 request_seq;
686 	__u16 i;
687 
688 	request_seq = ntohl(tsnreq->request_seq);
689 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
690 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
691 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
692 		goto err;
693 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
694 		i = asoc->strreset_inseq - request_seq - 1;
695 		result = asoc->strreset_result[i];
696 		if (result == SCTP_STRRESET_PERFORMED) {
697 			next_tsn = asoc->ctsn_ack_point + 1;
698 			init_tsn =
699 				sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1;
700 		}
701 		goto err;
702 	}
703 
704 	if (!sctp_outq_is_empty(&asoc->outqueue)) {
705 		result = SCTP_STRRESET_IN_PROGRESS;
706 		goto err;
707 	}
708 
709 	asoc->strreset_inseq++;
710 
711 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
712 		goto out;
713 
714 	if (asoc->strreset_outstanding) {
715 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
716 		goto out;
717 	}
718 
719 	/* G4: The same processing as though a FWD-TSN chunk (as defined in
720 	 *     [RFC3758]) with all streams affected and a new cumulative TSN
721 	 *     ACK of the Receiver's Next TSN minus 1 were received MUST be
722 	 *     performed.
723 	 */
724 	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
725 	asoc->stream.si->report_ftsn(&asoc->ulpq, max_tsn_seen);
726 
727 	/* G1: Compute an appropriate value for the Receiver's Next TSN -- the
728 	 *     TSN that the peer should use to send the next DATA chunk.  The
729 	 *     value SHOULD be the smallest TSN not acknowledged by the
730 	 *     receiver of the request plus 2^31.
731 	 */
732 	init_tsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + (1 << 31);
733 	sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
734 			 init_tsn, GFP_ATOMIC);
735 
736 	/* G3: The same processing as though a SACK chunk with no gap report
737 	 *     and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
738 	 *     received MUST be performed.
739 	 */
740 	sctp_outq_free(&asoc->outqueue);
741 
742 	/* G2: Compute an appropriate value for the local endpoint's next TSN,
743 	 *     i.e., the next TSN assigned by the receiver of the SSN/TSN reset
744 	 *     chunk.  The value SHOULD be the highest TSN sent by the receiver
745 	 *     of the request plus 1.
746 	 */
747 	next_tsn = asoc->next_tsn;
748 	asoc->ctsn_ack_point = next_tsn - 1;
749 	asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
750 
751 	/* G5:  The next expected and outgoing SSNs MUST be reset to 0 for all
752 	 *      incoming and outgoing streams.
753 	 */
754 	for (i = 0; i < stream->outcnt; i++) {
755 		SCTP_SO(stream, i)->mid = 0;
756 		SCTP_SO(stream, i)->mid_uo = 0;
757 	}
758 	for (i = 0; i < stream->incnt; i++)
759 		SCTP_SI(stream, i)->mid = 0;
760 
761 	result = SCTP_STRRESET_PERFORMED;
762 
763 	*evp = sctp_ulpevent_make_assoc_reset_event(asoc, 0, init_tsn,
764 						    next_tsn, GFP_ATOMIC);
765 
766 out:
767 	sctp_update_strreset_result(asoc, result);
768 err:
769 	return sctp_make_strreset_tsnresp(asoc, result, request_seq,
770 					  next_tsn, init_tsn);
771 }
772 
773 struct sctp_chunk *sctp_process_strreset_addstrm_out(
774 				struct sctp_association *asoc,
775 				union sctp_params param,
776 				struct sctp_ulpevent **evp)
777 {
778 	struct sctp_strreset_addstrm *addstrm = param.v;
779 	struct sctp_stream *stream = &asoc->stream;
780 	__u32 result = SCTP_STRRESET_DENIED;
781 	__u32 request_seq, incnt;
782 	__u16 in, i;
783 
784 	request_seq = ntohl(addstrm->request_seq);
785 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
786 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
787 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
788 		goto err;
789 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
790 		i = asoc->strreset_inseq - request_seq - 1;
791 		result = asoc->strreset_result[i];
792 		goto err;
793 	}
794 	asoc->strreset_inseq++;
795 
796 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
797 		goto out;
798 
799 	in = ntohs(addstrm->number_of_streams);
800 	incnt = stream->incnt + in;
801 	if (!in || incnt > SCTP_MAX_STREAM)
802 		goto out;
803 
804 	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
805 		goto out;
806 
807 	if (asoc->strreset_chunk) {
808 		if (!sctp_chunk_lookup_strreset_param(
809 			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
810 			/* same process with outstanding isn't 0 */
811 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
812 			goto out;
813 		}
814 
815 		asoc->strreset_outstanding--;
816 		asoc->strreset_outseq++;
817 
818 		if (!asoc->strreset_outstanding) {
819 			struct sctp_transport *t;
820 
821 			t = asoc->strreset_chunk->transport;
822 			if (del_timer(&t->reconf_timer))
823 				sctp_transport_put(t);
824 
825 			sctp_chunk_put(asoc->strreset_chunk);
826 			asoc->strreset_chunk = NULL;
827 		}
828 	}
829 
830 	stream->incnt = incnt;
831 
832 	result = SCTP_STRRESET_PERFORMED;
833 
834 	*evp = sctp_ulpevent_make_stream_change_event(asoc,
835 		0, ntohs(addstrm->number_of_streams), 0, GFP_ATOMIC);
836 
837 out:
838 	sctp_update_strreset_result(asoc, result);
839 err:
840 	return sctp_make_strreset_resp(asoc, result, request_seq);
841 }
842 
843 struct sctp_chunk *sctp_process_strreset_addstrm_in(
844 				struct sctp_association *asoc,
845 				union sctp_params param,
846 				struct sctp_ulpevent **evp)
847 {
848 	struct sctp_strreset_addstrm *addstrm = param.v;
849 	struct sctp_stream *stream = &asoc->stream;
850 	__u32 result = SCTP_STRRESET_DENIED;
851 	struct sctp_chunk *chunk = NULL;
852 	__u32 request_seq, outcnt;
853 	__u16 out, i;
854 	int ret;
855 
856 	request_seq = ntohl(addstrm->request_seq);
857 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
858 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
859 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
860 		goto err;
861 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
862 		i = asoc->strreset_inseq - request_seq - 1;
863 		result = asoc->strreset_result[i];
864 		if (result == SCTP_STRRESET_PERFORMED)
865 			return NULL;
866 		goto err;
867 	}
868 	asoc->strreset_inseq++;
869 
870 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
871 		goto out;
872 
873 	if (asoc->strreset_outstanding) {
874 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
875 		goto out;
876 	}
877 
878 	out = ntohs(addstrm->number_of_streams);
879 	outcnt = stream->outcnt + out;
880 	if (!out || outcnt > SCTP_MAX_STREAM)
881 		goto out;
882 
883 	ret = sctp_stream_alloc_out(stream, outcnt, GFP_ATOMIC);
884 	if (ret)
885 		goto out;
886 
887 	chunk = sctp_make_strreset_addstrm(asoc, out, 0);
888 	if (!chunk)
889 		goto out;
890 
891 	asoc->strreset_chunk = chunk;
892 	asoc->strreset_outstanding = 1;
893 	sctp_chunk_hold(asoc->strreset_chunk);
894 
895 	stream->outcnt = outcnt;
896 
897 	result = SCTP_STRRESET_PERFORMED;
898 
899 out:
900 	sctp_update_strreset_result(asoc, result);
901 err:
902 	if (!chunk)
903 		chunk = sctp_make_strreset_resp(asoc, result, request_seq);
904 
905 	return chunk;
906 }
907 
908 struct sctp_chunk *sctp_process_strreset_resp(
909 				struct sctp_association *asoc,
910 				union sctp_params param,
911 				struct sctp_ulpevent **evp)
912 {
913 	struct sctp_stream *stream = &asoc->stream;
914 	struct sctp_strreset_resp *resp = param.v;
915 	struct sctp_transport *t;
916 	__u16 i, nums, flags = 0;
917 	struct sctp_paramhdr *req;
918 	__u32 result;
919 
920 	req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0);
921 	if (!req)
922 		return NULL;
923 
924 	result = ntohl(resp->result);
925 	if (result != SCTP_STRRESET_PERFORMED) {
926 		/* if in progress, do nothing but retransmit */
927 		if (result == SCTP_STRRESET_IN_PROGRESS)
928 			return NULL;
929 		else if (result == SCTP_STRRESET_DENIED)
930 			flags = SCTP_STREAM_RESET_DENIED;
931 		else
932 			flags = SCTP_STREAM_RESET_FAILED;
933 	}
934 
935 	if (req->type == SCTP_PARAM_RESET_OUT_REQUEST) {
936 		struct sctp_strreset_outreq *outreq;
937 		__be16 *str_p;
938 
939 		outreq = (struct sctp_strreset_outreq *)req;
940 		str_p = outreq->list_of_streams;
941 		nums = (ntohs(outreq->param_hdr.length) - sizeof(*outreq)) /
942 		       sizeof(__u16);
943 
944 		if (result == SCTP_STRRESET_PERFORMED) {
945 			struct sctp_stream_out *sout;
946 			if (nums) {
947 				for (i = 0; i < nums; i++) {
948 					sout = SCTP_SO(stream, ntohs(str_p[i]));
949 					sout->mid = 0;
950 					sout->mid_uo = 0;
951 				}
952 			} else {
953 				for (i = 0; i < stream->outcnt; i++) {
954 					sout = SCTP_SO(stream, i);
955 					sout->mid = 0;
956 					sout->mid_uo = 0;
957 				}
958 			}
959 		}
960 
961 		flags |= SCTP_STREAM_RESET_OUTGOING_SSN;
962 
963 		for (i = 0; i < stream->outcnt; i++)
964 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
965 
966 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
967 			nums, str_p, GFP_ATOMIC);
968 	} else if (req->type == SCTP_PARAM_RESET_IN_REQUEST) {
969 		struct sctp_strreset_inreq *inreq;
970 		__be16 *str_p;
971 
972 		/* if the result is performed, it's impossible for inreq */
973 		if (result == SCTP_STRRESET_PERFORMED)
974 			return NULL;
975 
976 		inreq = (struct sctp_strreset_inreq *)req;
977 		str_p = inreq->list_of_streams;
978 		nums = (ntohs(inreq->param_hdr.length) - sizeof(*inreq)) /
979 		       sizeof(__u16);
980 
981 		flags |= SCTP_STREAM_RESET_INCOMING_SSN;
982 
983 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
984 			nums, str_p, GFP_ATOMIC);
985 	} else if (req->type == SCTP_PARAM_RESET_TSN_REQUEST) {
986 		struct sctp_strreset_resptsn *resptsn;
987 		__u32 stsn, rtsn;
988 
989 		/* check for resptsn, as sctp_verify_reconf didn't do it*/
990 		if (ntohs(param.p->length) != sizeof(*resptsn))
991 			return NULL;
992 
993 		resptsn = (struct sctp_strreset_resptsn *)resp;
994 		stsn = ntohl(resptsn->senders_next_tsn);
995 		rtsn = ntohl(resptsn->receivers_next_tsn);
996 
997 		if (result == SCTP_STRRESET_PERFORMED) {
998 			__u32 mtsn = sctp_tsnmap_get_max_tsn_seen(
999 						&asoc->peer.tsn_map);
1000 			LIST_HEAD(temp);
1001 
1002 			asoc->stream.si->report_ftsn(&asoc->ulpq, mtsn);
1003 
1004 			sctp_tsnmap_init(&asoc->peer.tsn_map,
1005 					 SCTP_TSN_MAP_INITIAL,
1006 					 stsn, GFP_ATOMIC);
1007 
1008 			/* Clean up sacked and abandoned queues only. As the
1009 			 * out_chunk_list may not be empty, splice it to temp,
1010 			 * then get it back after sctp_outq_free is done.
1011 			 */
1012 			list_splice_init(&asoc->outqueue.out_chunk_list, &temp);
1013 			sctp_outq_free(&asoc->outqueue);
1014 			list_splice_init(&temp, &asoc->outqueue.out_chunk_list);
1015 
1016 			asoc->next_tsn = rtsn;
1017 			asoc->ctsn_ack_point = asoc->next_tsn - 1;
1018 			asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1019 
1020 			for (i = 0; i < stream->outcnt; i++) {
1021 				SCTP_SO(stream, i)->mid = 0;
1022 				SCTP_SO(stream, i)->mid_uo = 0;
1023 			}
1024 			for (i = 0; i < stream->incnt; i++)
1025 				SCTP_SI(stream, i)->mid = 0;
1026 		}
1027 
1028 		for (i = 0; i < stream->outcnt; i++)
1029 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1030 
1031 		*evp = sctp_ulpevent_make_assoc_reset_event(asoc, flags,
1032 			stsn, rtsn, GFP_ATOMIC);
1033 	} else if (req->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS) {
1034 		struct sctp_strreset_addstrm *addstrm;
1035 		__u16 number;
1036 
1037 		addstrm = (struct sctp_strreset_addstrm *)req;
1038 		nums = ntohs(addstrm->number_of_streams);
1039 		number = stream->outcnt - nums;
1040 
1041 		if (result == SCTP_STRRESET_PERFORMED)
1042 			for (i = number; i < stream->outcnt; i++)
1043 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1044 		else
1045 			stream->outcnt = number;
1046 
1047 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1048 			0, nums, GFP_ATOMIC);
1049 	} else if (req->type == SCTP_PARAM_RESET_ADD_IN_STREAMS) {
1050 		struct sctp_strreset_addstrm *addstrm;
1051 
1052 		/* if the result is performed, it's impossible for addstrm in
1053 		 * request.
1054 		 */
1055 		if (result == SCTP_STRRESET_PERFORMED)
1056 			return NULL;
1057 
1058 		addstrm = (struct sctp_strreset_addstrm *)req;
1059 		nums = ntohs(addstrm->number_of_streams);
1060 
1061 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1062 			nums, 0, GFP_ATOMIC);
1063 	}
1064 
1065 	asoc->strreset_outstanding--;
1066 	asoc->strreset_outseq++;
1067 
1068 	/* remove everything for this reconf request */
1069 	if (!asoc->strreset_outstanding) {
1070 		t = asoc->strreset_chunk->transport;
1071 		if (del_timer(&t->reconf_timer))
1072 			sctp_transport_put(t);
1073 
1074 		sctp_chunk_put(asoc->strreset_chunk);
1075 		asoc->strreset_chunk = NULL;
1076 	}
1077 
1078 	return NULL;
1079 }
1080