xref: /openbmc/linux/net/sctp/stream.c (revision aeb64ff3)
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 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;
132 
133 	for (i = 0; i < stream->outcnt; i++)
134 		SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
135 
136 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 		sched->free(stream);
144 		genradix_free(&stream->out);
145 		stream->outcnt = 0;
146 		goto out;
147 	}
148 
149 out:
150 	return ret;
151 }
152 
153 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid)
154 {
155 	struct sctp_stream_out_ext *soute;
156 	int ret;
157 
158 	soute = kzalloc(sizeof(*soute), GFP_KERNEL);
159 	if (!soute)
160 		return -ENOMEM;
161 	SCTP_SO(stream, sid)->ext = soute;
162 
163 	ret = sctp_sched_init_sid(stream, sid, GFP_KERNEL);
164 	if (ret) {
165 		kfree(SCTP_SO(stream, sid)->ext);
166 		SCTP_SO(stream, sid)->ext = NULL;
167 	}
168 
169 	return ret;
170 }
171 
172 void sctp_stream_free(struct sctp_stream *stream)
173 {
174 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
175 	int i;
176 
177 	sched->free(stream);
178 	for (i = 0; i < stream->outcnt; i++)
179 		kfree(SCTP_SO(stream, i)->ext);
180 	genradix_free(&stream->out);
181 	genradix_free(&stream->in);
182 }
183 
184 void sctp_stream_clear(struct sctp_stream *stream)
185 {
186 	int i;
187 
188 	for (i = 0; i < stream->outcnt; i++) {
189 		SCTP_SO(stream, i)->mid = 0;
190 		SCTP_SO(stream, i)->mid_uo = 0;
191 	}
192 
193 	for (i = 0; i < stream->incnt; i++)
194 		SCTP_SI(stream, i)->mid = 0;
195 }
196 
197 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
198 {
199 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
200 
201 	sched->unsched_all(stream);
202 	sctp_stream_outq_migrate(stream, new, new->outcnt);
203 	sctp_stream_free(stream);
204 
205 	stream->out = new->out;
206 	stream->in  = new->in;
207 	stream->outcnt = new->outcnt;
208 	stream->incnt  = new->incnt;
209 
210 	sched->sched_all(stream);
211 
212 	new->out.tree.root = NULL;
213 	new->in.tree.root  = NULL;
214 	new->outcnt = 0;
215 	new->incnt  = 0;
216 }
217 
218 static int sctp_send_reconf(struct sctp_association *asoc,
219 			    struct sctp_chunk *chunk)
220 {
221 	struct net *net = sock_net(asoc->base.sk);
222 	int retval = 0;
223 
224 	retval = sctp_primitive_RECONF(net, asoc, chunk);
225 	if (retval)
226 		sctp_chunk_free(chunk);
227 
228 	return retval;
229 }
230 
231 static bool sctp_stream_outq_is_empty(struct sctp_stream *stream,
232 				      __u16 str_nums, __be16 *str_list)
233 {
234 	struct sctp_association *asoc;
235 	__u16 i;
236 
237 	asoc = container_of(stream, struct sctp_association, stream);
238 	if (!asoc->outqueue.out_qlen)
239 		return true;
240 
241 	if (!str_nums)
242 		return false;
243 
244 	for (i = 0; i < str_nums; i++) {
245 		__u16 sid = ntohs(str_list[i]);
246 
247 		if (SCTP_SO(stream, sid)->ext &&
248 		    !list_empty(&SCTP_SO(stream, sid)->ext->outq))
249 			return false;
250 	}
251 
252 	return true;
253 }
254 
255 int sctp_send_reset_streams(struct sctp_association *asoc,
256 			    struct sctp_reset_streams *params)
257 {
258 	struct sctp_stream *stream = &asoc->stream;
259 	__u16 i, str_nums, *str_list;
260 	struct sctp_chunk *chunk;
261 	int retval = -EINVAL;
262 	__be16 *nstr_list;
263 	bool out, in;
264 
265 	if (!asoc->peer.reconf_capable ||
266 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ)) {
267 		retval = -ENOPROTOOPT;
268 		goto out;
269 	}
270 
271 	if (asoc->strreset_outstanding) {
272 		retval = -EINPROGRESS;
273 		goto out;
274 	}
275 
276 	out = params->srs_flags & SCTP_STREAM_RESET_OUTGOING;
277 	in  = params->srs_flags & SCTP_STREAM_RESET_INCOMING;
278 	if (!out && !in)
279 		goto out;
280 
281 	str_nums = params->srs_number_streams;
282 	str_list = params->srs_stream_list;
283 	if (str_nums) {
284 		int param_len = 0;
285 
286 		if (out) {
287 			for (i = 0; i < str_nums; i++)
288 				if (str_list[i] >= stream->outcnt)
289 					goto out;
290 
291 			param_len = str_nums * sizeof(__u16) +
292 				    sizeof(struct sctp_strreset_outreq);
293 		}
294 
295 		if (in) {
296 			for (i = 0; i < str_nums; i++)
297 				if (str_list[i] >= stream->incnt)
298 					goto out;
299 
300 			param_len += str_nums * sizeof(__u16) +
301 				     sizeof(struct sctp_strreset_inreq);
302 		}
303 
304 		if (param_len > SCTP_MAX_CHUNK_LEN -
305 				sizeof(struct sctp_reconf_chunk))
306 			goto out;
307 	}
308 
309 	nstr_list = kcalloc(str_nums, sizeof(__be16), GFP_KERNEL);
310 	if (!nstr_list) {
311 		retval = -ENOMEM;
312 		goto out;
313 	}
314 
315 	for (i = 0; i < str_nums; i++)
316 		nstr_list[i] = htons(str_list[i]);
317 
318 	if (out && !sctp_stream_outq_is_empty(stream, str_nums, nstr_list)) {
319 		kfree(nstr_list);
320 		retval = -EAGAIN;
321 		goto out;
322 	}
323 
324 	chunk = sctp_make_strreset_req(asoc, str_nums, nstr_list, out, in);
325 
326 	kfree(nstr_list);
327 
328 	if (!chunk) {
329 		retval = -ENOMEM;
330 		goto out;
331 	}
332 
333 	if (out) {
334 		if (str_nums)
335 			for (i = 0; i < str_nums; i++)
336 				SCTP_SO(stream, str_list[i])->state =
337 						       SCTP_STREAM_CLOSED;
338 		else
339 			for (i = 0; i < stream->outcnt; i++)
340 				SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
341 	}
342 
343 	asoc->strreset_chunk = chunk;
344 	sctp_chunk_hold(asoc->strreset_chunk);
345 
346 	retval = sctp_send_reconf(asoc, chunk);
347 	if (retval) {
348 		sctp_chunk_put(asoc->strreset_chunk);
349 		asoc->strreset_chunk = NULL;
350 		if (!out)
351 			goto out;
352 
353 		if (str_nums)
354 			for (i = 0; i < str_nums; i++)
355 				SCTP_SO(stream, str_list[i])->state =
356 						       SCTP_STREAM_OPEN;
357 		else
358 			for (i = 0; i < stream->outcnt; i++)
359 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
360 
361 		goto out;
362 	}
363 
364 	asoc->strreset_outstanding = out + in;
365 
366 out:
367 	return retval;
368 }
369 
370 int sctp_send_reset_assoc(struct sctp_association *asoc)
371 {
372 	struct sctp_stream *stream = &asoc->stream;
373 	struct sctp_chunk *chunk = NULL;
374 	int retval;
375 	__u16 i;
376 
377 	if (!asoc->peer.reconf_capable ||
378 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
379 		return -ENOPROTOOPT;
380 
381 	if (asoc->strreset_outstanding)
382 		return -EINPROGRESS;
383 
384 	if (!sctp_outq_is_empty(&asoc->outqueue))
385 		return -EAGAIN;
386 
387 	chunk = sctp_make_strreset_tsnreq(asoc);
388 	if (!chunk)
389 		return -ENOMEM;
390 
391 	/* Block further xmit of data until this request is completed */
392 	for (i = 0; i < stream->outcnt; i++)
393 		SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
394 
395 	asoc->strreset_chunk = chunk;
396 	sctp_chunk_hold(asoc->strreset_chunk);
397 
398 	retval = sctp_send_reconf(asoc, chunk);
399 	if (retval) {
400 		sctp_chunk_put(asoc->strreset_chunk);
401 		asoc->strreset_chunk = NULL;
402 
403 		for (i = 0; i < stream->outcnt; i++)
404 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
405 
406 		return retval;
407 	}
408 
409 	asoc->strreset_outstanding = 1;
410 
411 	return 0;
412 }
413 
414 int sctp_send_add_streams(struct sctp_association *asoc,
415 			  struct sctp_add_streams *params)
416 {
417 	struct sctp_stream *stream = &asoc->stream;
418 	struct sctp_chunk *chunk = NULL;
419 	int retval;
420 	__u32 outcnt, incnt;
421 	__u16 out, in;
422 
423 	if (!asoc->peer.reconf_capable ||
424 	    !(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ)) {
425 		retval = -ENOPROTOOPT;
426 		goto out;
427 	}
428 
429 	if (asoc->strreset_outstanding) {
430 		retval = -EINPROGRESS;
431 		goto out;
432 	}
433 
434 	out = params->sas_outstrms;
435 	in  = params->sas_instrms;
436 	outcnt = stream->outcnt + out;
437 	incnt = stream->incnt + in;
438 	if (outcnt > SCTP_MAX_STREAM || incnt > SCTP_MAX_STREAM ||
439 	    (!out && !in)) {
440 		retval = -EINVAL;
441 		goto out;
442 	}
443 
444 	if (out) {
445 		retval = sctp_stream_alloc_out(stream, outcnt, GFP_KERNEL);
446 		if (retval)
447 			goto out;
448 	}
449 
450 	chunk = sctp_make_strreset_addstrm(asoc, out, in);
451 	if (!chunk) {
452 		retval = -ENOMEM;
453 		goto out;
454 	}
455 
456 	asoc->strreset_chunk = chunk;
457 	sctp_chunk_hold(asoc->strreset_chunk);
458 
459 	retval = sctp_send_reconf(asoc, chunk);
460 	if (retval) {
461 		sctp_chunk_put(asoc->strreset_chunk);
462 		asoc->strreset_chunk = NULL;
463 		goto out;
464 	}
465 
466 	asoc->strreset_outstanding = !!out + !!in;
467 
468 out:
469 	return retval;
470 }
471 
472 static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param(
473 			struct sctp_association *asoc, __be32 resp_seq,
474 			__be16 type)
475 {
476 	struct sctp_chunk *chunk = asoc->strreset_chunk;
477 	struct sctp_reconf_chunk *hdr;
478 	union sctp_params param;
479 
480 	if (!chunk)
481 		return NULL;
482 
483 	hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
484 	sctp_walk_params(param, hdr, params) {
485 		/* sctp_strreset_tsnreq is actually the basic structure
486 		 * of all stream reconf params, so it's safe to use it
487 		 * to access request_seq.
488 		 */
489 		struct sctp_strreset_tsnreq *req = param.v;
490 
491 		if ((!resp_seq || req->request_seq == resp_seq) &&
492 		    (!type || type == req->param_hdr.type))
493 			return param.v;
494 	}
495 
496 	return NULL;
497 }
498 
499 static void sctp_update_strreset_result(struct sctp_association *asoc,
500 					__u32 result)
501 {
502 	asoc->strreset_result[1] = asoc->strreset_result[0];
503 	asoc->strreset_result[0] = result;
504 }
505 
506 struct sctp_chunk *sctp_process_strreset_outreq(
507 				struct sctp_association *asoc,
508 				union sctp_params param,
509 				struct sctp_ulpevent **evp)
510 {
511 	struct sctp_strreset_outreq *outreq = param.v;
512 	struct sctp_stream *stream = &asoc->stream;
513 	__u32 result = SCTP_STRRESET_DENIED;
514 	__be16 *str_p = NULL;
515 	__u32 request_seq;
516 	__u16 i, nums;
517 
518 	request_seq = ntohl(outreq->request_seq);
519 
520 	if (ntohl(outreq->send_reset_at_tsn) >
521 	    sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) {
522 		result = SCTP_STRRESET_IN_PROGRESS;
523 		goto err;
524 	}
525 
526 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
527 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
528 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
529 		goto err;
530 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
531 		i = asoc->strreset_inseq - request_seq - 1;
532 		result = asoc->strreset_result[i];
533 		goto err;
534 	}
535 	asoc->strreset_inseq++;
536 
537 	/* Check strreset_enable after inseq inc, as sender cannot tell
538 	 * the peer doesn't enable strreset after receiving response with
539 	 * result denied, as well as to keep consistent with bsd.
540 	 */
541 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
542 		goto out;
543 
544 	nums = (ntohs(param.p->length) - sizeof(*outreq)) / sizeof(__u16);
545 	str_p = outreq->list_of_streams;
546 	for (i = 0; i < nums; i++) {
547 		if (ntohs(str_p[i]) >= stream->incnt) {
548 			result = SCTP_STRRESET_ERR_WRONG_SSN;
549 			goto out;
550 		}
551 	}
552 
553 	if (asoc->strreset_chunk) {
554 		if (!sctp_chunk_lookup_strreset_param(
555 				asoc, outreq->response_seq,
556 				SCTP_PARAM_RESET_IN_REQUEST)) {
557 			/* same process with outstanding isn't 0 */
558 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
559 			goto out;
560 		}
561 
562 		asoc->strreset_outstanding--;
563 		asoc->strreset_outseq++;
564 
565 		if (!asoc->strreset_outstanding) {
566 			struct sctp_transport *t;
567 
568 			t = asoc->strreset_chunk->transport;
569 			if (del_timer(&t->reconf_timer))
570 				sctp_transport_put(t);
571 
572 			sctp_chunk_put(asoc->strreset_chunk);
573 			asoc->strreset_chunk = NULL;
574 		}
575 	}
576 
577 	if (nums)
578 		for (i = 0; i < nums; i++)
579 			SCTP_SI(stream, ntohs(str_p[i]))->mid = 0;
580 	else
581 		for (i = 0; i < stream->incnt; i++)
582 			SCTP_SI(stream, i)->mid = 0;
583 
584 	result = SCTP_STRRESET_PERFORMED;
585 
586 	*evp = sctp_ulpevent_make_stream_reset_event(asoc,
587 		SCTP_STREAM_RESET_INCOMING_SSN, nums, str_p, GFP_ATOMIC);
588 
589 out:
590 	sctp_update_strreset_result(asoc, result);
591 err:
592 	return sctp_make_strreset_resp(asoc, result, request_seq);
593 }
594 
595 struct sctp_chunk *sctp_process_strreset_inreq(
596 				struct sctp_association *asoc,
597 				union sctp_params param,
598 				struct sctp_ulpevent **evp)
599 {
600 	struct sctp_strreset_inreq *inreq = param.v;
601 	struct sctp_stream *stream = &asoc->stream;
602 	__u32 result = SCTP_STRRESET_DENIED;
603 	struct sctp_chunk *chunk = NULL;
604 	__u32 request_seq;
605 	__u16 i, nums;
606 	__be16 *str_p;
607 
608 	request_seq = ntohl(inreq->request_seq);
609 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
610 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
611 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
612 		goto err;
613 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
614 		i = asoc->strreset_inseq - request_seq - 1;
615 		result = asoc->strreset_result[i];
616 		if (result == SCTP_STRRESET_PERFORMED)
617 			return NULL;
618 		goto err;
619 	}
620 	asoc->strreset_inseq++;
621 
622 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
623 		goto out;
624 
625 	if (asoc->strreset_outstanding) {
626 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
627 		goto out;
628 	}
629 
630 	nums = (ntohs(param.p->length) - sizeof(*inreq)) / sizeof(__u16);
631 	str_p = inreq->list_of_streams;
632 	for (i = 0; i < nums; i++) {
633 		if (ntohs(str_p[i]) >= stream->outcnt) {
634 			result = SCTP_STRRESET_ERR_WRONG_SSN;
635 			goto out;
636 		}
637 	}
638 
639 	if (!sctp_stream_outq_is_empty(stream, nums, str_p)) {
640 		result = SCTP_STRRESET_IN_PROGRESS;
641 		asoc->strreset_inseq--;
642 		goto err;
643 	}
644 
645 	chunk = sctp_make_strreset_req(asoc, nums, str_p, 1, 0);
646 	if (!chunk)
647 		goto out;
648 
649 	if (nums)
650 		for (i = 0; i < nums; i++)
651 			SCTP_SO(stream, ntohs(str_p[i]))->state =
652 					       SCTP_STREAM_CLOSED;
653 	else
654 		for (i = 0; i < stream->outcnt; i++)
655 			SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
656 
657 	asoc->strreset_chunk = chunk;
658 	asoc->strreset_outstanding = 1;
659 	sctp_chunk_hold(asoc->strreset_chunk);
660 
661 	result = SCTP_STRRESET_PERFORMED;
662 
663 out:
664 	sctp_update_strreset_result(asoc, result);
665 err:
666 	if (!chunk)
667 		chunk =  sctp_make_strreset_resp(asoc, result, request_seq);
668 
669 	return chunk;
670 }
671 
672 struct sctp_chunk *sctp_process_strreset_tsnreq(
673 				struct sctp_association *asoc,
674 				union sctp_params param,
675 				struct sctp_ulpevent **evp)
676 {
677 	__u32 init_tsn = 0, next_tsn = 0, max_tsn_seen;
678 	struct sctp_strreset_tsnreq *tsnreq = param.v;
679 	struct sctp_stream *stream = &asoc->stream;
680 	__u32 result = SCTP_STRRESET_DENIED;
681 	__u32 request_seq;
682 	__u16 i;
683 
684 	request_seq = ntohl(tsnreq->request_seq);
685 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
686 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
687 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
688 		goto err;
689 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
690 		i = asoc->strreset_inseq - request_seq - 1;
691 		result = asoc->strreset_result[i];
692 		if (result == SCTP_STRRESET_PERFORMED) {
693 			next_tsn = asoc->ctsn_ack_point + 1;
694 			init_tsn =
695 				sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1;
696 		}
697 		goto err;
698 	}
699 
700 	if (!sctp_outq_is_empty(&asoc->outqueue)) {
701 		result = SCTP_STRRESET_IN_PROGRESS;
702 		goto err;
703 	}
704 
705 	asoc->strreset_inseq++;
706 
707 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
708 		goto out;
709 
710 	if (asoc->strreset_outstanding) {
711 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
712 		goto out;
713 	}
714 
715 	/* G4: The same processing as though a FWD-TSN chunk (as defined in
716 	 *     [RFC3758]) with all streams affected and a new cumulative TSN
717 	 *     ACK of the Receiver's Next TSN minus 1 were received MUST be
718 	 *     performed.
719 	 */
720 	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
721 	asoc->stream.si->report_ftsn(&asoc->ulpq, max_tsn_seen);
722 
723 	/* G1: Compute an appropriate value for the Receiver's Next TSN -- the
724 	 *     TSN that the peer should use to send the next DATA chunk.  The
725 	 *     value SHOULD be the smallest TSN not acknowledged by the
726 	 *     receiver of the request plus 2^31.
727 	 */
728 	init_tsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + (1 << 31);
729 	sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
730 			 init_tsn, GFP_ATOMIC);
731 
732 	/* G3: The same processing as though a SACK chunk with no gap report
733 	 *     and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
734 	 *     received MUST be performed.
735 	 */
736 	sctp_outq_free(&asoc->outqueue);
737 
738 	/* G2: Compute an appropriate value for the local endpoint's next TSN,
739 	 *     i.e., the next TSN assigned by the receiver of the SSN/TSN reset
740 	 *     chunk.  The value SHOULD be the highest TSN sent by the receiver
741 	 *     of the request plus 1.
742 	 */
743 	next_tsn = asoc->next_tsn;
744 	asoc->ctsn_ack_point = next_tsn - 1;
745 	asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
746 
747 	/* G5:  The next expected and outgoing SSNs MUST be reset to 0 for all
748 	 *      incoming and outgoing streams.
749 	 */
750 	for (i = 0; i < stream->outcnt; i++) {
751 		SCTP_SO(stream, i)->mid = 0;
752 		SCTP_SO(stream, i)->mid_uo = 0;
753 	}
754 	for (i = 0; i < stream->incnt; i++)
755 		SCTP_SI(stream, i)->mid = 0;
756 
757 	result = SCTP_STRRESET_PERFORMED;
758 
759 	*evp = sctp_ulpevent_make_assoc_reset_event(asoc, 0, init_tsn,
760 						    next_tsn, GFP_ATOMIC);
761 
762 out:
763 	sctp_update_strreset_result(asoc, result);
764 err:
765 	return sctp_make_strreset_tsnresp(asoc, result, request_seq,
766 					  next_tsn, init_tsn);
767 }
768 
769 struct sctp_chunk *sctp_process_strreset_addstrm_out(
770 				struct sctp_association *asoc,
771 				union sctp_params param,
772 				struct sctp_ulpevent **evp)
773 {
774 	struct sctp_strreset_addstrm *addstrm = param.v;
775 	struct sctp_stream *stream = &asoc->stream;
776 	__u32 result = SCTP_STRRESET_DENIED;
777 	__u32 request_seq, incnt;
778 	__u16 in, i;
779 
780 	request_seq = ntohl(addstrm->request_seq);
781 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
782 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
783 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
784 		goto err;
785 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
786 		i = asoc->strreset_inseq - request_seq - 1;
787 		result = asoc->strreset_result[i];
788 		goto err;
789 	}
790 	asoc->strreset_inseq++;
791 
792 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
793 		goto out;
794 
795 	in = ntohs(addstrm->number_of_streams);
796 	incnt = stream->incnt + in;
797 	if (!in || incnt > SCTP_MAX_STREAM)
798 		goto out;
799 
800 	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
801 		goto out;
802 
803 	if (asoc->strreset_chunk) {
804 		if (!sctp_chunk_lookup_strreset_param(
805 			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
806 			/* same process with outstanding isn't 0 */
807 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
808 			goto out;
809 		}
810 
811 		asoc->strreset_outstanding--;
812 		asoc->strreset_outseq++;
813 
814 		if (!asoc->strreset_outstanding) {
815 			struct sctp_transport *t;
816 
817 			t = asoc->strreset_chunk->transport;
818 			if (del_timer(&t->reconf_timer))
819 				sctp_transport_put(t);
820 
821 			sctp_chunk_put(asoc->strreset_chunk);
822 			asoc->strreset_chunk = NULL;
823 		}
824 	}
825 
826 	stream->incnt = incnt;
827 
828 	result = SCTP_STRRESET_PERFORMED;
829 
830 	*evp = sctp_ulpevent_make_stream_change_event(asoc,
831 		0, ntohs(addstrm->number_of_streams), 0, GFP_ATOMIC);
832 
833 out:
834 	sctp_update_strreset_result(asoc, result);
835 err:
836 	return sctp_make_strreset_resp(asoc, result, request_seq);
837 }
838 
839 struct sctp_chunk *sctp_process_strreset_addstrm_in(
840 				struct sctp_association *asoc,
841 				union sctp_params param,
842 				struct sctp_ulpevent **evp)
843 {
844 	struct sctp_strreset_addstrm *addstrm = param.v;
845 	struct sctp_stream *stream = &asoc->stream;
846 	__u32 result = SCTP_STRRESET_DENIED;
847 	struct sctp_chunk *chunk = NULL;
848 	__u32 request_seq, outcnt;
849 	__u16 out, i;
850 	int ret;
851 
852 	request_seq = ntohl(addstrm->request_seq);
853 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
854 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
855 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
856 		goto err;
857 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
858 		i = asoc->strreset_inseq - request_seq - 1;
859 		result = asoc->strreset_result[i];
860 		if (result == SCTP_STRRESET_PERFORMED)
861 			return NULL;
862 		goto err;
863 	}
864 	asoc->strreset_inseq++;
865 
866 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
867 		goto out;
868 
869 	if (asoc->strreset_outstanding) {
870 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
871 		goto out;
872 	}
873 
874 	out = ntohs(addstrm->number_of_streams);
875 	outcnt = stream->outcnt + out;
876 	if (!out || outcnt > SCTP_MAX_STREAM)
877 		goto out;
878 
879 	ret = sctp_stream_alloc_out(stream, outcnt, GFP_ATOMIC);
880 	if (ret)
881 		goto out;
882 
883 	chunk = sctp_make_strreset_addstrm(asoc, out, 0);
884 	if (!chunk)
885 		goto out;
886 
887 	asoc->strreset_chunk = chunk;
888 	asoc->strreset_outstanding = 1;
889 	sctp_chunk_hold(asoc->strreset_chunk);
890 
891 	stream->outcnt = outcnt;
892 
893 	result = SCTP_STRRESET_PERFORMED;
894 
895 out:
896 	sctp_update_strreset_result(asoc, result);
897 err:
898 	if (!chunk)
899 		chunk = sctp_make_strreset_resp(asoc, result, request_seq);
900 
901 	return chunk;
902 }
903 
904 struct sctp_chunk *sctp_process_strreset_resp(
905 				struct sctp_association *asoc,
906 				union sctp_params param,
907 				struct sctp_ulpevent **evp)
908 {
909 	struct sctp_stream *stream = &asoc->stream;
910 	struct sctp_strreset_resp *resp = param.v;
911 	struct sctp_transport *t;
912 	__u16 i, nums, flags = 0;
913 	struct sctp_paramhdr *req;
914 	__u32 result;
915 
916 	req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0);
917 	if (!req)
918 		return NULL;
919 
920 	result = ntohl(resp->result);
921 	if (result != SCTP_STRRESET_PERFORMED) {
922 		/* if in progress, do nothing but retransmit */
923 		if (result == SCTP_STRRESET_IN_PROGRESS)
924 			return NULL;
925 		else if (result == SCTP_STRRESET_DENIED)
926 			flags = SCTP_STREAM_RESET_DENIED;
927 		else
928 			flags = SCTP_STREAM_RESET_FAILED;
929 	}
930 
931 	if (req->type == SCTP_PARAM_RESET_OUT_REQUEST) {
932 		struct sctp_strreset_outreq *outreq;
933 		__be16 *str_p;
934 
935 		outreq = (struct sctp_strreset_outreq *)req;
936 		str_p = outreq->list_of_streams;
937 		nums = (ntohs(outreq->param_hdr.length) - sizeof(*outreq)) /
938 		       sizeof(__u16);
939 
940 		if (result == SCTP_STRRESET_PERFORMED) {
941 			struct sctp_stream_out *sout;
942 			if (nums) {
943 				for (i = 0; i < nums; i++) {
944 					sout = SCTP_SO(stream, ntohs(str_p[i]));
945 					sout->mid = 0;
946 					sout->mid_uo = 0;
947 				}
948 			} else {
949 				for (i = 0; i < stream->outcnt; i++) {
950 					sout = SCTP_SO(stream, i);
951 					sout->mid = 0;
952 					sout->mid_uo = 0;
953 				}
954 			}
955 		}
956 
957 		flags |= SCTP_STREAM_RESET_OUTGOING_SSN;
958 
959 		for (i = 0; i < stream->outcnt; i++)
960 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
961 
962 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
963 			nums, str_p, GFP_ATOMIC);
964 	} else if (req->type == SCTP_PARAM_RESET_IN_REQUEST) {
965 		struct sctp_strreset_inreq *inreq;
966 		__be16 *str_p;
967 
968 		/* if the result is performed, it's impossible for inreq */
969 		if (result == SCTP_STRRESET_PERFORMED)
970 			return NULL;
971 
972 		inreq = (struct sctp_strreset_inreq *)req;
973 		str_p = inreq->list_of_streams;
974 		nums = (ntohs(inreq->param_hdr.length) - sizeof(*inreq)) /
975 		       sizeof(__u16);
976 
977 		flags |= SCTP_STREAM_RESET_INCOMING_SSN;
978 
979 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
980 			nums, str_p, GFP_ATOMIC);
981 	} else if (req->type == SCTP_PARAM_RESET_TSN_REQUEST) {
982 		struct sctp_strreset_resptsn *resptsn;
983 		__u32 stsn, rtsn;
984 
985 		/* check for resptsn, as sctp_verify_reconf didn't do it*/
986 		if (ntohs(param.p->length) != sizeof(*resptsn))
987 			return NULL;
988 
989 		resptsn = (struct sctp_strreset_resptsn *)resp;
990 		stsn = ntohl(resptsn->senders_next_tsn);
991 		rtsn = ntohl(resptsn->receivers_next_tsn);
992 
993 		if (result == SCTP_STRRESET_PERFORMED) {
994 			__u32 mtsn = sctp_tsnmap_get_max_tsn_seen(
995 						&asoc->peer.tsn_map);
996 			LIST_HEAD(temp);
997 
998 			asoc->stream.si->report_ftsn(&asoc->ulpq, mtsn);
999 
1000 			sctp_tsnmap_init(&asoc->peer.tsn_map,
1001 					 SCTP_TSN_MAP_INITIAL,
1002 					 stsn, GFP_ATOMIC);
1003 
1004 			/* Clean up sacked and abandoned queues only. As the
1005 			 * out_chunk_list may not be empty, splice it to temp,
1006 			 * then get it back after sctp_outq_free is done.
1007 			 */
1008 			list_splice_init(&asoc->outqueue.out_chunk_list, &temp);
1009 			sctp_outq_free(&asoc->outqueue);
1010 			list_splice_init(&temp, &asoc->outqueue.out_chunk_list);
1011 
1012 			asoc->next_tsn = rtsn;
1013 			asoc->ctsn_ack_point = asoc->next_tsn - 1;
1014 			asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1015 
1016 			for (i = 0; i < stream->outcnt; i++) {
1017 				SCTP_SO(stream, i)->mid = 0;
1018 				SCTP_SO(stream, i)->mid_uo = 0;
1019 			}
1020 			for (i = 0; i < stream->incnt; i++)
1021 				SCTP_SI(stream, i)->mid = 0;
1022 		}
1023 
1024 		for (i = 0; i < stream->outcnt; i++)
1025 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1026 
1027 		*evp = sctp_ulpevent_make_assoc_reset_event(asoc, flags,
1028 			stsn, rtsn, GFP_ATOMIC);
1029 	} else if (req->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS) {
1030 		struct sctp_strreset_addstrm *addstrm;
1031 		__u16 number;
1032 
1033 		addstrm = (struct sctp_strreset_addstrm *)req;
1034 		nums = ntohs(addstrm->number_of_streams);
1035 		number = stream->outcnt - nums;
1036 
1037 		if (result == SCTP_STRRESET_PERFORMED)
1038 			for (i = number; i < stream->outcnt; i++)
1039 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1040 		else
1041 			stream->outcnt = number;
1042 
1043 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1044 			0, nums, GFP_ATOMIC);
1045 	} else if (req->type == SCTP_PARAM_RESET_ADD_IN_STREAMS) {
1046 		struct sctp_strreset_addstrm *addstrm;
1047 
1048 		/* if the result is performed, it's impossible for addstrm in
1049 		 * request.
1050 		 */
1051 		if (result == SCTP_STRRESET_PERFORMED)
1052 			return NULL;
1053 
1054 		addstrm = (struct sctp_strreset_addstrm *)req;
1055 		nums = ntohs(addstrm->number_of_streams);
1056 
1057 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1058 			nums, 0, GFP_ATOMIC);
1059 	}
1060 
1061 	asoc->strreset_outstanding--;
1062 	asoc->strreset_outseq++;
1063 
1064 	/* remove everything for this reconf request */
1065 	if (!asoc->strreset_outstanding) {
1066 		t = asoc->strreset_chunk->transport;
1067 		if (del_timer(&t->reconf_timer))
1068 			sctp_transport_put(t);
1069 
1070 		sctp_chunk_put(asoc->strreset_chunk);
1071 		asoc->strreset_chunk = NULL;
1072 	}
1073 
1074 	return NULL;
1075 }
1076