xref: /linux/net/sctp/stream.c (revision 1b78070aaef63512688aebfbc82365ef9d6660f1)
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 #define SCTP_STRRESET_MASK(type) \
26 	BIT(ntohs(type) - ntohs(SCTP_PARAM_RESET_OUT_REQUEST))
27 #define SCTP_STRRESET_TEST(asoc, type) \
28 	((asoc)->strreset_outstanding & SCTP_STRRESET_MASK(type))
29 #define SCTP_STRRESET_SET(asoc, type) \
30 	((asoc)->strreset_outstanding |= SCTP_STRRESET_MASK(type))
31 #define SCTP_STRRESET_CLEAR(asoc, type) \
32 	((asoc)->strreset_outstanding &= ~SCTP_STRRESET_MASK(type))
33 
34 static void sctp_stream_shrink_out(struct sctp_stream *stream, __u16 outcnt)
35 {
36 	struct sctp_association *asoc;
37 	struct sctp_chunk *ch, *temp;
38 	struct sctp_outq *outq;
39 
40 	asoc = container_of(stream, struct sctp_association, stream);
41 	outq = &asoc->outqueue;
42 
43 	list_for_each_entry_safe(ch, temp, &outq->out_chunk_list, list) {
44 		__u16 sid = sctp_chunk_stream_no(ch);
45 
46 		if (sid < outcnt)
47 			continue;
48 
49 		sctp_sched_dequeue_common(outq, ch);
50 		/* No need to call dequeue_done here because
51 		 * the chunks are not scheduled by now.
52 		 */
53 
54 		/* Mark as failed send. */
55 		sctp_chunk_fail(ch, (__force __u32)SCTP_ERROR_INV_STRM);
56 		if (asoc->peer.prsctp_capable &&
57 		    SCTP_PR_PRIO_ENABLED(ch->sinfo.sinfo_flags))
58 			asoc->sent_cnt_removable--;
59 
60 		sctp_chunk_free(ch);
61 	}
62 }
63 
64 static void sctp_stream_free_ext(struct sctp_stream *stream, __u16 sid)
65 {
66 	const struct sctp_sched_ops *sched;
67 
68 	if (!SCTP_SO(stream, sid)->ext)
69 		return;
70 
71 	sched = sctp_sched_ops_from_stream(stream);
72 	sched->free_sid(stream, sid);
73 	kfree(SCTP_SO(stream, sid)->ext);
74 	SCTP_SO(stream, sid)->ext = NULL;
75 }
76 
77 /* Migrates chunks from stream queues to new stream queues if needed,
78  * but not across associations. Also, removes those chunks to streams
79  * higher than the new max.
80  */
81 static void sctp_stream_outq_migrate(struct sctp_stream *stream,
82 				     struct sctp_stream *new, __u16 outcnt)
83 {
84 	int i;
85 
86 	if (stream->outcnt > outcnt)
87 		sctp_stream_shrink_out(stream, outcnt);
88 
89 	if (new) {
90 		/* Here we actually move the old ext stuff into the new
91 		 * buffer, because we want to keep it. Then
92 		 * sctp_stream_update will swap ->out pointers.
93 		 */
94 		for (i = 0; i < outcnt; i++) {
95 			sctp_stream_free_ext(new, i);
96 			SCTP_SO(new, i)->ext = SCTP_SO(stream, i)->ext;
97 			SCTP_SO(stream, i)->ext = NULL;
98 		}
99 	}
100 
101 	for (i = outcnt; i < stream->outcnt; i++)
102 		sctp_stream_free_ext(stream, i);
103 }
104 
105 static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
106 				 gfp_t gfp)
107 {
108 	int ret;
109 
110 	if (outcnt <= stream->outcnt)
111 		goto out;
112 
113 	ret = genradix_prealloc(&stream->out, outcnt, gfp);
114 	if (ret)
115 		return ret;
116 
117 out:
118 	stream->outcnt = outcnt;
119 	return 0;
120 }
121 
122 static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
123 				gfp_t gfp)
124 {
125 	int ret;
126 
127 	if (incnt <= stream->incnt)
128 		goto out;
129 
130 	ret = genradix_prealloc(&stream->in, incnt, gfp);
131 	if (ret)
132 		return ret;
133 
134 out:
135 	stream->incnt = incnt;
136 	return 0;
137 }
138 
139 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
140 		     gfp_t gfp)
141 {
142 	const struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
143 	int i, ret = 0;
144 
145 	gfp |= __GFP_NOWARN;
146 
147 	/* Initial stream->out size may be very big, so free it and alloc
148 	 * a new one with new outcnt to save memory if needed.
149 	 */
150 	if (outcnt == stream->outcnt)
151 		goto handle_in;
152 
153 	/* Filter out chunks queued on streams that won't exist anymore */
154 	sched->unsched_all(stream);
155 	sctp_stream_outq_migrate(stream, NULL, outcnt);
156 	sched->sched_all(stream);
157 
158 	ret = sctp_stream_alloc_out(stream, outcnt, gfp);
159 	if (ret)
160 		return ret;
161 
162 	for (i = 0; i < stream->outcnt; i++)
163 		SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
164 
165 handle_in:
166 	sctp_stream_interleave_init(stream);
167 	if (!incnt)
168 		return 0;
169 
170 	return sctp_stream_alloc_in(stream, incnt, gfp);
171 }
172 
173 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid)
174 {
175 	struct sctp_stream_out_ext *soute;
176 	int ret;
177 
178 	soute = kzalloc_obj(*soute);
179 	if (!soute)
180 		return -ENOMEM;
181 	SCTP_SO(stream, sid)->ext = soute;
182 
183 	ret = sctp_sched_init_sid(stream, sid, GFP_KERNEL);
184 	if (ret) {
185 		kfree(SCTP_SO(stream, sid)->ext);
186 		SCTP_SO(stream, sid)->ext = NULL;
187 	}
188 
189 	return ret;
190 }
191 
192 void sctp_stream_free(struct sctp_stream *stream)
193 {
194 	const struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
195 	int i;
196 
197 	sched->unsched_all(stream);
198 	for (i = 0; i < stream->outcnt; i++)
199 		sctp_stream_free_ext(stream, i);
200 	genradix_free(&stream->out);
201 	genradix_free(&stream->in);
202 }
203 
204 void sctp_stream_clear(struct sctp_stream *stream)
205 {
206 	int i;
207 
208 	for (i = 0; i < stream->outcnt; i++) {
209 		SCTP_SO(stream, i)->mid = 0;
210 		SCTP_SO(stream, i)->mid_uo = 0;
211 	}
212 
213 	for (i = 0; i < stream->incnt; i++)
214 		SCTP_SI(stream, i)->mid = 0;
215 }
216 
217 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
218 {
219 	const struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
220 
221 	sched->unsched_all(stream);
222 	sctp_stream_outq_migrate(stream, new, new->outcnt);
223 	sctp_stream_free(stream);
224 
225 	stream->out = new->out;
226 	stream->in  = new->in;
227 	stream->outcnt = new->outcnt;
228 	stream->incnt  = new->incnt;
229 
230 	sched->sched_all(stream);
231 
232 	new->out.tree.root = NULL;
233 	new->in.tree.root  = NULL;
234 	new->outcnt = 0;
235 	new->incnt  = 0;
236 }
237 
238 static int sctp_send_reconf(struct sctp_association *asoc,
239 			    struct sctp_chunk *chunk)
240 {
241 	int retval = 0;
242 
243 	retval = sctp_primitive_RECONF(asoc->base.net, asoc, chunk);
244 	if (retval)
245 		sctp_chunk_free(chunk);
246 
247 	return retval;
248 }
249 
250 static bool sctp_stream_outq_is_empty(struct sctp_stream *stream,
251 				      __u16 str_nums, __be16 *str_list)
252 {
253 	struct sctp_association *asoc;
254 	__u16 i;
255 
256 	asoc = container_of(stream, struct sctp_association, stream);
257 	if (!asoc->outqueue.out_qlen)
258 		return true;
259 
260 	if (!str_nums)
261 		return false;
262 
263 	for (i = 0; i < str_nums; i++) {
264 		__u16 sid = ntohs(str_list[i]);
265 
266 		if (SCTP_SO(stream, sid)->ext &&
267 		    !list_empty(&SCTP_SO(stream, sid)->ext->outq))
268 			return false;
269 	}
270 
271 	return true;
272 }
273 
274 int sctp_send_reset_streams(struct sctp_association *asoc,
275 			    struct sctp_reset_streams *params)
276 {
277 	struct sctp_stream *stream = &asoc->stream;
278 	__u16 i, str_nums, *str_list;
279 	struct sctp_chunk *chunk;
280 	int retval = -EINVAL;
281 	__be16 *nstr_list;
282 	bool out, in;
283 
284 	if (!asoc->peer.reconf_capable ||
285 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ)) {
286 		retval = -ENOPROTOOPT;
287 		goto out;
288 	}
289 
290 	if (asoc->strreset_outstanding) {
291 		retval = -EINPROGRESS;
292 		goto out;
293 	}
294 
295 	out = params->srs_flags & SCTP_STREAM_RESET_OUTGOING;
296 	in  = params->srs_flags & SCTP_STREAM_RESET_INCOMING;
297 	if (!out && !in)
298 		goto out;
299 
300 	str_nums = params->srs_number_streams;
301 	str_list = params->srs_stream_list;
302 	if (str_nums) {
303 		int param_len = 0;
304 
305 		if (out) {
306 			for (i = 0; i < str_nums; i++)
307 				if (str_list[i] >= stream->outcnt)
308 					goto out;
309 
310 			param_len = str_nums * sizeof(__u16) +
311 				    sizeof(struct sctp_strreset_outreq);
312 		}
313 
314 		if (in) {
315 			for (i = 0; i < str_nums; i++)
316 				if (str_list[i] >= stream->incnt)
317 					goto out;
318 
319 			param_len += str_nums * sizeof(__u16) +
320 				     (out ? sizeof(struct sctp_strreset_inreq)
321 					  : sizeof(struct sctp_strreset_outreq));
322 		}
323 
324 		if (param_len > SCTP_MAX_CHUNK_LEN -
325 				sizeof(struct sctp_reconf_chunk))
326 			goto out;
327 	}
328 
329 	nstr_list = kcalloc(str_nums, sizeof(__be16), GFP_KERNEL);
330 	if (!nstr_list) {
331 		retval = -ENOMEM;
332 		goto out;
333 	}
334 
335 	for (i = 0; i < str_nums; i++)
336 		nstr_list[i] = htons(str_list[i]);
337 
338 	if (out && !sctp_stream_outq_is_empty(stream, str_nums, nstr_list)) {
339 		kfree(nstr_list);
340 		retval = -EAGAIN;
341 		goto out;
342 	}
343 
344 	chunk = sctp_make_strreset_req(asoc, str_nums, nstr_list, out, in);
345 
346 	kfree(nstr_list);
347 
348 	if (!chunk) {
349 		retval = -ENOMEM;
350 		goto out;
351 	}
352 
353 	if (out) {
354 		if (str_nums)
355 			for (i = 0; i < str_nums; i++)
356 				SCTP_SO(stream, str_list[i])->state =
357 						       SCTP_STREAM_CLOSED;
358 		else
359 			for (i = 0; i < stream->outcnt; i++)
360 				SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
361 	}
362 
363 	asoc->strreset_chunk = chunk;
364 	sctp_chunk_hold(asoc->strreset_chunk);
365 
366 	retval = sctp_send_reconf(asoc, chunk);
367 	if (retval) {
368 		sctp_chunk_put(asoc->strreset_chunk);
369 		asoc->strreset_chunk = NULL;
370 		if (!out)
371 			goto out;
372 
373 		if (str_nums)
374 			for (i = 0; i < str_nums; i++)
375 				SCTP_SO(stream, str_list[i])->state =
376 						       SCTP_STREAM_OPEN;
377 		else
378 			for (i = 0; i < stream->outcnt; i++)
379 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
380 
381 		goto out;
382 	}
383 
384 	if (out)
385 		SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_OUT_REQUEST);
386 	if (in)
387 		SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_IN_REQUEST);
388 
389 out:
390 	return retval;
391 }
392 
393 int sctp_send_reset_assoc(struct sctp_association *asoc)
394 {
395 	struct sctp_stream *stream = &asoc->stream;
396 	struct sctp_chunk *chunk = NULL;
397 	int retval;
398 	__u16 i;
399 
400 	if (!asoc->peer.reconf_capable ||
401 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
402 		return -ENOPROTOOPT;
403 
404 	if (asoc->strreset_outstanding)
405 		return -EINPROGRESS;
406 
407 	if (!sctp_outq_is_empty(&asoc->outqueue))
408 		return -EAGAIN;
409 
410 	chunk = sctp_make_strreset_tsnreq(asoc);
411 	if (!chunk)
412 		return -ENOMEM;
413 
414 	/* Block further xmit of data until this request is completed */
415 	for (i = 0; i < stream->outcnt; i++)
416 		SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
417 
418 	asoc->strreset_chunk = chunk;
419 	sctp_chunk_hold(asoc->strreset_chunk);
420 
421 	retval = sctp_send_reconf(asoc, chunk);
422 	if (retval) {
423 		sctp_chunk_put(asoc->strreset_chunk);
424 		asoc->strreset_chunk = NULL;
425 
426 		for (i = 0; i < stream->outcnt; i++)
427 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
428 
429 		return retval;
430 	}
431 
432 	SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_TSN_REQUEST);
433 
434 	return 0;
435 }
436 
437 int sctp_send_add_streams(struct sctp_association *asoc,
438 			  struct sctp_add_streams *params)
439 {
440 	struct sctp_stream *stream = &asoc->stream;
441 	struct sctp_chunk *chunk = NULL;
442 	int retval;
443 	__u32 outcnt, incnt;
444 	__u16 out, in;
445 
446 	if (!asoc->peer.reconf_capable ||
447 	    !(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ)) {
448 		retval = -ENOPROTOOPT;
449 		goto out;
450 	}
451 
452 	if (asoc->strreset_outstanding) {
453 		retval = -EINPROGRESS;
454 		goto out;
455 	}
456 
457 	out = params->sas_outstrms;
458 	in  = params->sas_instrms;
459 	outcnt = stream->outcnt + out;
460 	incnt = stream->incnt + in;
461 	if (outcnt > SCTP_MAX_STREAM || incnt > SCTP_MAX_STREAM ||
462 	    (!out && !in)) {
463 		retval = -EINVAL;
464 		goto out;
465 	}
466 
467 	if (out) {
468 		retval = sctp_stream_alloc_out(stream, outcnt, GFP_KERNEL);
469 		if (retval)
470 			goto out;
471 	}
472 
473 	chunk = sctp_make_strreset_addstrm(asoc, out, in);
474 	if (!chunk) {
475 		retval = -ENOMEM;
476 		goto out;
477 	}
478 
479 	asoc->strreset_chunk = chunk;
480 	sctp_chunk_hold(asoc->strreset_chunk);
481 
482 	retval = sctp_send_reconf(asoc, chunk);
483 	if (retval) {
484 		sctp_chunk_put(asoc->strreset_chunk);
485 		asoc->strreset_chunk = NULL;
486 		goto out;
487 	}
488 
489 	if (out)
490 		SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_ADD_OUT_STREAMS);
491 	if (in)
492 		SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_ADD_IN_STREAMS);
493 
494 out:
495 	return retval;
496 }
497 
498 static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param(
499 			struct sctp_association *asoc, __be32 resp_seq,
500 			__be16 type, bool match_seq)
501 {
502 	struct sctp_chunk *chunk = asoc->strreset_chunk;
503 	struct sctp_reconf_chunk *hdr;
504 	union sctp_params param;
505 
506 	if (!chunk || !chunk->transport)
507 		return NULL;
508 
509 	hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
510 	sctp_walk_params(param, hdr) {
511 		/* sctp_strreset_tsnreq is actually the basic structure
512 		 * of all stream reconf params, so it's safe to use it
513 		 * to access request_seq.
514 		 */
515 		struct sctp_strreset_tsnreq *req = param.v;
516 
517 		if ((!match_seq || req->request_seq == resp_seq) &&
518 		    (!type || type == req->param_hdr.type))
519 			return param.v;
520 	}
521 
522 	return NULL;
523 }
524 
525 static void sctp_update_strreset_result(struct sctp_association *asoc,
526 					__u32 result)
527 {
528 	asoc->strreset_result[1] = asoc->strreset_result[0];
529 	asoc->strreset_result[0] = result;
530 }
531 
532 struct sctp_chunk *sctp_process_strreset_outreq(
533 				struct sctp_association *asoc,
534 				union sctp_params param,
535 				struct sctp_ulpevent **evp)
536 {
537 	struct sctp_strreset_outreq *outreq = param.v;
538 	struct sctp_stream *stream = &asoc->stream;
539 	__u32 result = SCTP_STRRESET_DENIED;
540 	__be16 *str_p = NULL;
541 	__u32 request_seq;
542 	__u16 i, nums;
543 
544 	request_seq = ntohl(outreq->request_seq);
545 
546 	if (ntohl(outreq->send_reset_at_tsn) >
547 	    sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) {
548 		result = SCTP_STRRESET_IN_PROGRESS;
549 		goto err;
550 	}
551 
552 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
553 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
554 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
555 		goto err;
556 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
557 		i = asoc->strreset_inseq - request_seq - 1;
558 		result = asoc->strreset_result[i];
559 		goto err;
560 	}
561 	asoc->strreset_inseq++;
562 
563 	/* Check strreset_enable after inseq inc, as sender cannot tell
564 	 * the peer doesn't enable strreset after receiving response with
565 	 * result denied, as well as to keep consistent with bsd.
566 	 */
567 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
568 		goto out;
569 
570 	nums = (ntohs(param.p->length) - sizeof(*outreq)) / sizeof(__u16);
571 	str_p = outreq->list_of_streams;
572 	for (i = 0; i < nums; i++) {
573 		if (ntohs(str_p[i]) >= stream->incnt) {
574 			result = SCTP_STRRESET_ERR_WRONG_SSN;
575 			goto out;
576 		}
577 	}
578 
579 	if (asoc->strreset_chunk) {
580 		if (!sctp_chunk_lookup_strreset_param(
581 				asoc, outreq->response_seq,
582 				SCTP_PARAM_RESET_IN_REQUEST, true) ||
583 		    !SCTP_STRRESET_TEST(asoc, SCTP_PARAM_RESET_IN_REQUEST)) {
584 			/* same process with outstanding isn't 0 */
585 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
586 			goto out;
587 		}
588 
589 		SCTP_STRRESET_CLEAR(asoc, SCTP_PARAM_RESET_IN_REQUEST);
590 		asoc->strreset_outseq++;
591 
592 		if (!asoc->strreset_outstanding) {
593 			struct sctp_transport *t;
594 
595 			t = asoc->strreset_chunk->transport;
596 			if (timer_delete(&t->reconf_timer))
597 				sctp_transport_put(t);
598 
599 			sctp_chunk_put(asoc->strreset_chunk);
600 			asoc->strreset_chunk = NULL;
601 		}
602 	}
603 
604 	if (nums)
605 		for (i = 0; i < nums; i++)
606 			SCTP_SI(stream, ntohs(str_p[i]))->mid = 0;
607 	else
608 		for (i = 0; i < stream->incnt; i++)
609 			SCTP_SI(stream, i)->mid = 0;
610 
611 	result = SCTP_STRRESET_PERFORMED;
612 
613 	*evp = sctp_ulpevent_make_stream_reset_event(asoc,
614 		SCTP_STREAM_RESET_INCOMING_SSN, nums, str_p, GFP_ATOMIC);
615 
616 out:
617 	sctp_update_strreset_result(asoc, result);
618 err:
619 	return sctp_make_strreset_resp(asoc, result, request_seq);
620 }
621 
622 struct sctp_chunk *sctp_process_strreset_inreq(
623 				struct sctp_association *asoc,
624 				union sctp_params param,
625 				struct sctp_ulpevent **evp)
626 {
627 	struct sctp_strreset_inreq *inreq = param.v;
628 	struct sctp_stream *stream = &asoc->stream;
629 	__u32 result = SCTP_STRRESET_DENIED;
630 	struct sctp_chunk *chunk = NULL;
631 	__u32 request_seq;
632 	__u16 i, nums;
633 	__be16 *str_p;
634 
635 	request_seq = ntohl(inreq->request_seq);
636 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
637 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
638 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
639 		goto err;
640 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
641 		i = asoc->strreset_inseq - request_seq - 1;
642 		result = asoc->strreset_result[i];
643 		if (result == SCTP_STRRESET_PERFORMED)
644 			return NULL;
645 		goto err;
646 	}
647 	asoc->strreset_inseq++;
648 
649 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
650 		goto out;
651 
652 	if (asoc->strreset_outstanding) {
653 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
654 		goto out;
655 	}
656 
657 	nums = (ntohs(param.p->length) - sizeof(*inreq)) / sizeof(__u16);
658 	str_p = inreq->list_of_streams;
659 	if (nums * sizeof(__u16) + sizeof(struct sctp_strreset_outreq) >
660 	    SCTP_MAX_CHUNK_LEN - sizeof(struct sctp_reconf_chunk))
661 		goto out;
662 	for (i = 0; i < nums; i++) {
663 		if (ntohs(str_p[i]) >= stream->outcnt) {
664 			result = SCTP_STRRESET_ERR_WRONG_SSN;
665 			goto out;
666 		}
667 	}
668 
669 	if (!sctp_stream_outq_is_empty(stream, nums, str_p)) {
670 		result = SCTP_STRRESET_IN_PROGRESS;
671 		asoc->strreset_inseq--;
672 		goto err;
673 	}
674 
675 	chunk = sctp_make_strreset_req(asoc, nums, str_p, 1, 0);
676 	if (!chunk)
677 		goto out;
678 
679 	if (nums)
680 		for (i = 0; i < nums; i++)
681 			SCTP_SO(stream, ntohs(str_p[i]))->state =
682 					       SCTP_STREAM_CLOSED;
683 	else
684 		for (i = 0; i < stream->outcnt; i++)
685 			SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
686 
687 	asoc->strreset_chunk = chunk;
688 	SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_OUT_REQUEST);
689 	sctp_chunk_hold(asoc->strreset_chunk);
690 
691 	result = SCTP_STRRESET_PERFORMED;
692 
693 out:
694 	sctp_update_strreset_result(asoc, result);
695 err:
696 	if (!chunk)
697 		chunk =  sctp_make_strreset_resp(asoc, result, request_seq);
698 
699 	return chunk;
700 }
701 
702 struct sctp_chunk *sctp_process_strreset_tsnreq(
703 				struct sctp_association *asoc,
704 				union sctp_params param,
705 				struct sctp_ulpevent **evp)
706 {
707 	__u32 init_tsn = 0, next_tsn = 0, max_tsn_seen;
708 	struct sctp_strreset_tsnreq *tsnreq = param.v;
709 	struct sctp_stream *stream = &asoc->stream;
710 	__u32 result = SCTP_STRRESET_DENIED;
711 	__u32 request_seq;
712 	__u16 i;
713 
714 	request_seq = ntohl(tsnreq->request_seq);
715 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
716 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
717 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
718 		goto err;
719 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
720 		i = asoc->strreset_inseq - request_seq - 1;
721 		result = asoc->strreset_result[i];
722 		if (result == SCTP_STRRESET_PERFORMED) {
723 			next_tsn = asoc->ctsn_ack_point + 1;
724 			init_tsn =
725 				sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1;
726 		}
727 		goto err;
728 	}
729 
730 	if (!sctp_outq_is_empty(&asoc->outqueue)) {
731 		result = SCTP_STRRESET_IN_PROGRESS;
732 		goto err;
733 	}
734 
735 	asoc->strreset_inseq++;
736 
737 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
738 		goto out;
739 
740 	if (asoc->strreset_outstanding) {
741 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
742 		goto out;
743 	}
744 
745 	/* G4: The same processing as though a FWD-TSN chunk (as defined in
746 	 *     [RFC3758]) with all streams affected and a new cumulative TSN
747 	 *     ACK of the Receiver's Next TSN minus 1 were received MUST be
748 	 *     performed.
749 	 */
750 	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
751 	asoc->stream.si->report_ftsn(&asoc->ulpq, max_tsn_seen);
752 
753 	/* G1: Compute an appropriate value for the Receiver's Next TSN -- the
754 	 *     TSN that the peer should use to send the next DATA chunk.  The
755 	 *     value SHOULD be the smallest TSN not acknowledged by the
756 	 *     receiver of the request plus 2^31.
757 	 */
758 	init_tsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + (1U << 31);
759 	sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
760 			 init_tsn, GFP_ATOMIC);
761 
762 	/* G3: The same processing as though a SACK chunk with no gap report
763 	 *     and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
764 	 *     received MUST be performed.
765 	 */
766 	sctp_outq_free(&asoc->outqueue);
767 
768 	/* G2: Compute an appropriate value for the local endpoint's next TSN,
769 	 *     i.e., the next TSN assigned by the receiver of the SSN/TSN reset
770 	 *     chunk.  The value SHOULD be the highest TSN sent by the receiver
771 	 *     of the request plus 1.
772 	 */
773 	next_tsn = asoc->next_tsn;
774 	asoc->ctsn_ack_point = next_tsn - 1;
775 	asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
776 
777 	/* G5:  The next expected and outgoing SSNs MUST be reset to 0 for all
778 	 *      incoming and outgoing streams.
779 	 */
780 	for (i = 0; i < stream->outcnt; i++) {
781 		SCTP_SO(stream, i)->mid = 0;
782 		SCTP_SO(stream, i)->mid_uo = 0;
783 	}
784 	for (i = 0; i < stream->incnt; i++)
785 		SCTP_SI(stream, i)->mid = 0;
786 
787 	result = SCTP_STRRESET_PERFORMED;
788 
789 	*evp = sctp_ulpevent_make_assoc_reset_event(asoc, 0, init_tsn,
790 						    next_tsn, GFP_ATOMIC);
791 
792 out:
793 	sctp_update_strreset_result(asoc, result);
794 err:
795 	return sctp_make_strreset_tsnresp(asoc, result, request_seq,
796 					  next_tsn, init_tsn);
797 }
798 
799 struct sctp_chunk *sctp_process_strreset_addstrm_out(
800 				struct sctp_association *asoc,
801 				union sctp_params param,
802 				struct sctp_ulpevent **evp)
803 {
804 	struct sctp_strreset_addstrm *addstrm = param.v;
805 	struct sctp_stream *stream = &asoc->stream;
806 	__u32 result = SCTP_STRRESET_DENIED;
807 	__u32 request_seq, incnt;
808 	__u16 in, i;
809 
810 	request_seq = ntohl(addstrm->request_seq);
811 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
812 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
813 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
814 		goto err;
815 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
816 		i = asoc->strreset_inseq - request_seq - 1;
817 		result = asoc->strreset_result[i];
818 		goto err;
819 	}
820 	asoc->strreset_inseq++;
821 
822 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
823 		goto out;
824 
825 	in = ntohs(addstrm->number_of_streams);
826 	incnt = stream->incnt + in;
827 	if (!in || incnt > SCTP_MAX_STREAM)
828 		goto out;
829 
830 	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
831 		goto out;
832 
833 	if (asoc->strreset_chunk) {
834 		if (!sctp_chunk_lookup_strreset_param(
835 			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS, false) ||
836 		    !SCTP_STRRESET_TEST(asoc, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
837 			/* same process with outstanding isn't 0 */
838 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
839 			goto out;
840 		}
841 
842 		SCTP_STRRESET_CLEAR(asoc, SCTP_PARAM_RESET_ADD_IN_STREAMS);
843 		asoc->strreset_outseq++;
844 
845 		if (!asoc->strreset_outstanding) {
846 			struct sctp_transport *t;
847 
848 			t = asoc->strreset_chunk->transport;
849 			if (timer_delete(&t->reconf_timer))
850 				sctp_transport_put(t);
851 
852 			sctp_chunk_put(asoc->strreset_chunk);
853 			asoc->strreset_chunk = NULL;
854 		}
855 	}
856 
857 	stream->incnt = incnt;
858 
859 	result = SCTP_STRRESET_PERFORMED;
860 
861 	*evp = sctp_ulpevent_make_stream_change_event(asoc,
862 		0, ntohs(addstrm->number_of_streams), 0, GFP_ATOMIC);
863 
864 out:
865 	sctp_update_strreset_result(asoc, result);
866 err:
867 	return sctp_make_strreset_resp(asoc, result, request_seq);
868 }
869 
870 struct sctp_chunk *sctp_process_strreset_addstrm_in(
871 				struct sctp_association *asoc,
872 				union sctp_params param,
873 				struct sctp_ulpevent **evp)
874 {
875 	struct sctp_strreset_addstrm *addstrm = param.v;
876 	struct sctp_stream *stream = &asoc->stream;
877 	__u32 result = SCTP_STRRESET_DENIED;
878 	struct sctp_chunk *chunk = NULL;
879 	__u32 request_seq, outcnt;
880 	__u16 out, i;
881 	int ret;
882 
883 	request_seq = ntohl(addstrm->request_seq);
884 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
885 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
886 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
887 		goto err;
888 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
889 		i = asoc->strreset_inseq - request_seq - 1;
890 		result = asoc->strreset_result[i];
891 		if (result == SCTP_STRRESET_PERFORMED)
892 			return NULL;
893 		goto err;
894 	}
895 	asoc->strreset_inseq++;
896 
897 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
898 		goto out;
899 
900 	if (asoc->strreset_outstanding) {
901 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
902 		goto out;
903 	}
904 
905 	out = ntohs(addstrm->number_of_streams);
906 	outcnt = stream->outcnt + out;
907 	if (!out || outcnt > SCTP_MAX_STREAM)
908 		goto out;
909 
910 	ret = sctp_stream_alloc_out(stream, outcnt, GFP_ATOMIC);
911 	if (ret)
912 		goto out;
913 
914 	chunk = sctp_make_strreset_addstrm(asoc, out, 0);
915 	if (!chunk)
916 		goto out;
917 
918 	asoc->strreset_chunk = chunk;
919 	SCTP_STRRESET_SET(asoc, SCTP_PARAM_RESET_ADD_OUT_STREAMS);
920 	sctp_chunk_hold(asoc->strreset_chunk);
921 
922 	stream->outcnt = outcnt;
923 
924 	result = SCTP_STRRESET_PERFORMED;
925 
926 out:
927 	sctp_update_strreset_result(asoc, result);
928 err:
929 	if (!chunk)
930 		chunk = sctp_make_strreset_resp(asoc, result, request_seq);
931 
932 	return chunk;
933 }
934 
935 struct sctp_chunk *sctp_process_strreset_resp(
936 				struct sctp_association *asoc,
937 				union sctp_params param,
938 				struct sctp_ulpevent **evp)
939 {
940 	struct sctp_stream *stream = &asoc->stream;
941 	struct sctp_strreset_resp *resp = param.v;
942 	struct sctp_transport *t;
943 	__u16 i, nums, flags = 0;
944 	struct sctp_paramhdr *req;
945 	__u32 result;
946 
947 	req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0,
948 					       true);
949 	if (!req || !SCTP_STRRESET_TEST(asoc, req->type))
950 		return NULL;
951 
952 	result = ntohl(resp->result);
953 	if (result != SCTP_STRRESET_PERFORMED) {
954 		/* if in progress, do nothing but retransmit */
955 		if (result == SCTP_STRRESET_IN_PROGRESS)
956 			return NULL;
957 		else if (result == SCTP_STRRESET_DENIED)
958 			flags = SCTP_STREAM_RESET_DENIED;
959 		else
960 			flags = SCTP_STREAM_RESET_FAILED;
961 	}
962 
963 	if (req->type == SCTP_PARAM_RESET_OUT_REQUEST) {
964 		struct sctp_strreset_outreq *outreq;
965 		__be16 *str_p;
966 
967 		outreq = (struct sctp_strreset_outreq *)req;
968 		str_p = outreq->list_of_streams;
969 		nums = (ntohs(outreq->param_hdr.length) - sizeof(*outreq)) /
970 		       sizeof(__u16);
971 
972 		if (result == SCTP_STRRESET_PERFORMED) {
973 			struct sctp_stream_out *sout;
974 			if (nums) {
975 				for (i = 0; i < nums; i++) {
976 					sout = SCTP_SO(stream, ntohs(str_p[i]));
977 					sout->mid = 0;
978 					sout->mid_uo = 0;
979 				}
980 			} else {
981 				for (i = 0; i < stream->outcnt; i++) {
982 					sout = SCTP_SO(stream, i);
983 					sout->mid = 0;
984 					sout->mid_uo = 0;
985 				}
986 			}
987 		}
988 
989 		flags |= SCTP_STREAM_RESET_OUTGOING_SSN;
990 
991 		for (i = 0; i < stream->outcnt; i++)
992 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
993 
994 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
995 			nums, str_p, GFP_ATOMIC);
996 	} else if (req->type == SCTP_PARAM_RESET_IN_REQUEST) {
997 		struct sctp_strreset_inreq *inreq;
998 		__be16 *str_p;
999 
1000 		/* if the result is performed, it's impossible for inreq */
1001 		if (result == SCTP_STRRESET_PERFORMED)
1002 			return NULL;
1003 
1004 		inreq = (struct sctp_strreset_inreq *)req;
1005 		str_p = inreq->list_of_streams;
1006 		nums = (ntohs(inreq->param_hdr.length) - sizeof(*inreq)) /
1007 		       sizeof(__u16);
1008 
1009 		flags |= SCTP_STREAM_RESET_INCOMING_SSN;
1010 
1011 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
1012 			nums, str_p, GFP_ATOMIC);
1013 	} else if (req->type == SCTP_PARAM_RESET_TSN_REQUEST) {
1014 		struct sctp_strreset_resptsn *resptsn;
1015 		__u32 stsn, rtsn;
1016 
1017 		/* check for resptsn, as sctp_verify_reconf didn't do it*/
1018 		if (ntohs(param.p->length) != sizeof(*resptsn))
1019 			return NULL;
1020 
1021 		resptsn = (struct sctp_strreset_resptsn *)resp;
1022 		stsn = ntohl(resptsn->senders_next_tsn);
1023 		rtsn = ntohl(resptsn->receivers_next_tsn);
1024 
1025 		if (result == SCTP_STRRESET_PERFORMED) {
1026 			__u32 mtsn = sctp_tsnmap_get_max_tsn_seen(
1027 						&asoc->peer.tsn_map);
1028 			LIST_HEAD(temp);
1029 
1030 			asoc->stream.si->report_ftsn(&asoc->ulpq, mtsn);
1031 
1032 			sctp_tsnmap_init(&asoc->peer.tsn_map,
1033 					 SCTP_TSN_MAP_INITIAL,
1034 					 stsn, GFP_ATOMIC);
1035 
1036 			/* Clean up sacked and abandoned queues only. As the
1037 			 * out_chunk_list may not be empty, splice it to temp,
1038 			 * then get it back after sctp_outq_free is done.
1039 			 */
1040 			list_splice_init(&asoc->outqueue.out_chunk_list, &temp);
1041 			sctp_outq_free(&asoc->outqueue);
1042 			list_splice_init(&temp, &asoc->outqueue.out_chunk_list);
1043 
1044 			asoc->next_tsn = rtsn;
1045 			asoc->ctsn_ack_point = asoc->next_tsn - 1;
1046 			asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1047 
1048 			for (i = 0; i < stream->outcnt; i++) {
1049 				SCTP_SO(stream, i)->mid = 0;
1050 				SCTP_SO(stream, i)->mid_uo = 0;
1051 			}
1052 			for (i = 0; i < stream->incnt; i++)
1053 				SCTP_SI(stream, i)->mid = 0;
1054 		}
1055 
1056 		for (i = 0; i < stream->outcnt; i++)
1057 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1058 
1059 		*evp = sctp_ulpevent_make_assoc_reset_event(asoc, flags,
1060 			stsn, rtsn, GFP_ATOMIC);
1061 	} else if (req->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS) {
1062 		struct sctp_strreset_addstrm *addstrm;
1063 		const struct sctp_sched_ops *sched;
1064 		__u16 number;
1065 
1066 		addstrm = (struct sctp_strreset_addstrm *)req;
1067 		nums = ntohs(addstrm->number_of_streams);
1068 		number = stream->outcnt - nums;
1069 
1070 		if (result == SCTP_STRRESET_PERFORMED) {
1071 			for (i = number; i < stream->outcnt; i++)
1072 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1073 		} else {
1074 			sched = sctp_sched_ops_from_stream(stream);
1075 			sched->unsched_all(stream);
1076 			sctp_stream_outq_migrate(stream, NULL, number);
1077 			sched->sched_all(stream);
1078 			stream->outcnt = number;
1079 		}
1080 
1081 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1082 			0, nums, GFP_ATOMIC);
1083 	} else if (req->type == SCTP_PARAM_RESET_ADD_IN_STREAMS) {
1084 		struct sctp_strreset_addstrm *addstrm;
1085 
1086 		/* if the result is performed, it's impossible for addstrm in
1087 		 * request.
1088 		 */
1089 		if (result == SCTP_STRRESET_PERFORMED)
1090 			return NULL;
1091 
1092 		addstrm = (struct sctp_strreset_addstrm *)req;
1093 		nums = ntohs(addstrm->number_of_streams);
1094 
1095 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1096 			nums, 0, GFP_ATOMIC);
1097 	}
1098 
1099 	SCTP_STRRESET_CLEAR(asoc, req->type);
1100 	asoc->strreset_outseq++;
1101 
1102 	/* remove everything for this reconf request */
1103 	if (!asoc->strreset_outstanding) {
1104 		t = asoc->strreset_chunk->transport;
1105 		if (timer_delete(&t->reconf_timer))
1106 			sctp_transport_put(t);
1107 
1108 		sctp_chunk_put(asoc->strreset_chunk);
1109 		asoc->strreset_chunk = NULL;
1110 	}
1111 
1112 	return NULL;
1113 }
1114