xref: /openbmc/linux/net/sctp/stream.c (revision f9a82c48)
1 /* SCTP kernel implementation
2  * (C) Copyright IBM Corp. 2001, 2004
3  * Copyright (c) 1999-2000 Cisco, Inc.
4  * Copyright (c) 1999-2001 Motorola, Inc.
5  * Copyright (c) 2001 Intel Corp.
6  *
7  * This file is part of the SCTP kernel implementation
8  *
9  * This file contains sctp stream maniuplation primitives and helpers.
10  *
11  * This SCTP implementation is free software;
12  * you can redistribute it and/or modify it under the terms of
13  * the GNU General Public License as published by
14  * the Free Software Foundation; either version 2, or (at your option)
15  * any later version.
16  *
17  * This SCTP implementation is distributed in the hope that it
18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19  *                 ************************
20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21  * See the GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with GNU CC; see the file COPYING.  If not, see
25  * <http://www.gnu.org/licenses/>.
26  *
27  * Please send any bug reports or fixes you make to the
28  * email address(es):
29  *    lksctp developers <linux-sctp@vger.kernel.org>
30  *
31  * Written or modified by:
32  *    Xin Long <lucien.xin@gmail.com>
33  */
34 
35 #include <linux/list.h>
36 #include <net/sctp/sctp.h>
37 #include <net/sctp/sm.h>
38 #include <net/sctp/stream_sched.h>
39 
40 /* Migrates chunks from stream queues to new stream queues if needed,
41  * but not across associations. Also, removes those chunks to streams
42  * higher than the new max.
43  */
44 static void sctp_stream_outq_migrate(struct sctp_stream *stream,
45 				     struct sctp_stream *new, __u16 outcnt)
46 {
47 	struct sctp_association *asoc;
48 	struct sctp_chunk *ch, *temp;
49 	struct sctp_outq *outq;
50 	int i;
51 
52 	asoc = container_of(stream, struct sctp_association, stream);
53 	outq = &asoc->outqueue;
54 
55 	list_for_each_entry_safe(ch, temp, &outq->out_chunk_list, list) {
56 		__u16 sid = sctp_chunk_stream_no(ch);
57 
58 		if (sid < outcnt)
59 			continue;
60 
61 		sctp_sched_dequeue_common(outq, ch);
62 		/* No need to call dequeue_done here because
63 		 * the chunks are not scheduled by now.
64 		 */
65 
66 		/* Mark as failed send. */
67 		sctp_chunk_fail(ch, (__force __u32)SCTP_ERROR_INV_STRM);
68 		if (asoc->peer.prsctp_capable &&
69 		    SCTP_PR_PRIO_ENABLED(ch->sinfo.sinfo_flags))
70 			asoc->sent_cnt_removable--;
71 
72 		sctp_chunk_free(ch);
73 	}
74 
75 	if (new) {
76 		/* Here we actually move the old ext stuff into the new
77 		 * buffer, because we want to keep it. Then
78 		 * sctp_stream_update will swap ->out pointers.
79 		 */
80 		for (i = 0; i < outcnt; i++) {
81 			kfree(SCTP_SO(new, i)->ext);
82 			SCTP_SO(new, i)->ext = SCTP_SO(stream, i)->ext;
83 			SCTP_SO(stream, i)->ext = NULL;
84 		}
85 	}
86 
87 	for (i = outcnt; i < stream->outcnt; i++) {
88 		kfree(SCTP_SO(stream, i)->ext);
89 		SCTP_SO(stream, i)->ext = NULL;
90 	}
91 }
92 
93 static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
94 				 gfp_t gfp)
95 {
96 	int ret;
97 
98 	if (outcnt <= stream->outcnt)
99 		return 0;
100 
101 	ret = genradix_prealloc(&stream->out, outcnt, gfp);
102 	if (ret)
103 		return ret;
104 
105 	stream->outcnt = outcnt;
106 	return 0;
107 }
108 
109 static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
110 				gfp_t gfp)
111 {
112 	int ret;
113 
114 	if (incnt <= stream->incnt)
115 		return 0;
116 
117 	ret = genradix_prealloc(&stream->in, incnt, gfp);
118 	if (ret)
119 		return ret;
120 
121 	stream->incnt = incnt;
122 	return 0;
123 }
124 
125 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
126 		     gfp_t gfp)
127 {
128 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
129 	int i, ret = 0;
130 
131 	gfp |= __GFP_NOWARN;
132 
133 	/* Initial stream->out size may be very big, so free it and alloc
134 	 * a new one with new outcnt to save memory if needed.
135 	 */
136 	if (outcnt == stream->outcnt)
137 		goto in;
138 
139 	/* Filter out chunks queued on streams that won't exist anymore */
140 	sched->unsched_all(stream);
141 	sctp_stream_outq_migrate(stream, NULL, outcnt);
142 	sched->sched_all(stream);
143 
144 	ret = sctp_stream_alloc_out(stream, outcnt, gfp);
145 	if (ret)
146 		goto out;
147 
148 	for (i = 0; i < stream->outcnt; i++)
149 		SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
150 
151 in:
152 	sctp_stream_interleave_init(stream);
153 	if (!incnt)
154 		goto out;
155 
156 	ret = sctp_stream_alloc_in(stream, incnt, gfp);
157 	if (ret) {
158 		sched->free(stream);
159 		genradix_free(&stream->out);
160 		stream->outcnt = 0;
161 		goto out;
162 	}
163 
164 out:
165 	return ret;
166 }
167 
168 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid)
169 {
170 	struct sctp_stream_out_ext *soute;
171 
172 	soute = kzalloc(sizeof(*soute), GFP_KERNEL);
173 	if (!soute)
174 		return -ENOMEM;
175 	SCTP_SO(stream, sid)->ext = soute;
176 
177 	return sctp_sched_init_sid(stream, sid, GFP_KERNEL);
178 }
179 
180 void sctp_stream_free(struct sctp_stream *stream)
181 {
182 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
183 	int i;
184 
185 	sched->free(stream);
186 	for (i = 0; i < stream->outcnt; i++)
187 		kfree(SCTP_SO(stream, i)->ext);
188 	genradix_free(&stream->out);
189 	genradix_free(&stream->in);
190 }
191 
192 void sctp_stream_clear(struct sctp_stream *stream)
193 {
194 	int i;
195 
196 	for (i = 0; i < stream->outcnt; i++) {
197 		SCTP_SO(stream, i)->mid = 0;
198 		SCTP_SO(stream, i)->mid_uo = 0;
199 	}
200 
201 	for (i = 0; i < stream->incnt; i++)
202 		SCTP_SI(stream, i)->mid = 0;
203 }
204 
205 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
206 {
207 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
208 
209 	sched->unsched_all(stream);
210 	sctp_stream_outq_migrate(stream, new, new->outcnt);
211 	sctp_stream_free(stream);
212 
213 	stream->out = new->out;
214 	stream->in  = new->in;
215 	stream->outcnt = new->outcnt;
216 	stream->incnt  = new->incnt;
217 
218 	sched->sched_all(stream);
219 
220 	new->out.tree.root = NULL;
221 	new->in.tree.root  = NULL;
222 	new->outcnt = 0;
223 	new->incnt  = 0;
224 }
225 
226 static int sctp_send_reconf(struct sctp_association *asoc,
227 			    struct sctp_chunk *chunk)
228 {
229 	struct net *net = sock_net(asoc->base.sk);
230 	int retval = 0;
231 
232 	retval = sctp_primitive_RECONF(net, asoc, chunk);
233 	if (retval)
234 		sctp_chunk_free(chunk);
235 
236 	return retval;
237 }
238 
239 static bool sctp_stream_outq_is_empty(struct sctp_stream *stream,
240 				      __u16 str_nums, __be16 *str_list)
241 {
242 	struct sctp_association *asoc;
243 	__u16 i;
244 
245 	asoc = container_of(stream, struct sctp_association, stream);
246 	if (!asoc->outqueue.out_qlen)
247 		return true;
248 
249 	if (!str_nums)
250 		return false;
251 
252 	for (i = 0; i < str_nums; i++) {
253 		__u16 sid = ntohs(str_list[i]);
254 
255 		if (SCTP_SO(stream, sid)->ext &&
256 		    !list_empty(&SCTP_SO(stream, sid)->ext->outq))
257 			return false;
258 	}
259 
260 	return true;
261 }
262 
263 int sctp_send_reset_streams(struct sctp_association *asoc,
264 			    struct sctp_reset_streams *params)
265 {
266 	struct sctp_stream *stream = &asoc->stream;
267 	__u16 i, str_nums, *str_list;
268 	struct sctp_chunk *chunk;
269 	int retval = -EINVAL;
270 	__be16 *nstr_list;
271 	bool out, in;
272 
273 	if (!asoc->peer.reconf_capable ||
274 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ)) {
275 		retval = -ENOPROTOOPT;
276 		goto out;
277 	}
278 
279 	if (asoc->strreset_outstanding) {
280 		retval = -EINPROGRESS;
281 		goto out;
282 	}
283 
284 	out = params->srs_flags & SCTP_STREAM_RESET_OUTGOING;
285 	in  = params->srs_flags & SCTP_STREAM_RESET_INCOMING;
286 	if (!out && !in)
287 		goto out;
288 
289 	str_nums = params->srs_number_streams;
290 	str_list = params->srs_stream_list;
291 	if (str_nums) {
292 		int param_len = 0;
293 
294 		if (out) {
295 			for (i = 0; i < str_nums; i++)
296 				if (str_list[i] >= stream->outcnt)
297 					goto out;
298 
299 			param_len = str_nums * sizeof(__u16) +
300 				    sizeof(struct sctp_strreset_outreq);
301 		}
302 
303 		if (in) {
304 			for (i = 0; i < str_nums; i++)
305 				if (str_list[i] >= stream->incnt)
306 					goto out;
307 
308 			param_len += str_nums * sizeof(__u16) +
309 				     sizeof(struct sctp_strreset_inreq);
310 		}
311 
312 		if (param_len > SCTP_MAX_CHUNK_LEN -
313 				sizeof(struct sctp_reconf_chunk))
314 			goto out;
315 	}
316 
317 	nstr_list = kcalloc(str_nums, sizeof(__be16), GFP_KERNEL);
318 	if (!nstr_list) {
319 		retval = -ENOMEM;
320 		goto out;
321 	}
322 
323 	for (i = 0; i < str_nums; i++)
324 		nstr_list[i] = htons(str_list[i]);
325 
326 	if (out && !sctp_stream_outq_is_empty(stream, str_nums, nstr_list)) {
327 		retval = -EAGAIN;
328 		goto out;
329 	}
330 
331 	chunk = sctp_make_strreset_req(asoc, str_nums, nstr_list, out, in);
332 
333 	kfree(nstr_list);
334 
335 	if (!chunk) {
336 		retval = -ENOMEM;
337 		goto out;
338 	}
339 
340 	if (out) {
341 		if (str_nums)
342 			for (i = 0; i < str_nums; i++)
343 				SCTP_SO(stream, str_list[i])->state =
344 						       SCTP_STREAM_CLOSED;
345 		else
346 			for (i = 0; i < stream->outcnt; i++)
347 				SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
348 	}
349 
350 	asoc->strreset_chunk = chunk;
351 	sctp_chunk_hold(asoc->strreset_chunk);
352 
353 	retval = sctp_send_reconf(asoc, chunk);
354 	if (retval) {
355 		sctp_chunk_put(asoc->strreset_chunk);
356 		asoc->strreset_chunk = NULL;
357 		if (!out)
358 			goto out;
359 
360 		if (str_nums)
361 			for (i = 0; i < str_nums; i++)
362 				SCTP_SO(stream, str_list[i])->state =
363 						       SCTP_STREAM_OPEN;
364 		else
365 			for (i = 0; i < stream->outcnt; i++)
366 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
367 
368 		goto out;
369 	}
370 
371 	asoc->strreset_outstanding = out + in;
372 
373 out:
374 	return retval;
375 }
376 
377 int sctp_send_reset_assoc(struct sctp_association *asoc)
378 {
379 	struct sctp_stream *stream = &asoc->stream;
380 	struct sctp_chunk *chunk = NULL;
381 	int retval;
382 	__u16 i;
383 
384 	if (!asoc->peer.reconf_capable ||
385 	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
386 		return -ENOPROTOOPT;
387 
388 	if (asoc->strreset_outstanding)
389 		return -EINPROGRESS;
390 
391 	if (!sctp_outq_is_empty(&asoc->outqueue))
392 		return -EAGAIN;
393 
394 	chunk = sctp_make_strreset_tsnreq(asoc);
395 	if (!chunk)
396 		return -ENOMEM;
397 
398 	/* Block further xmit of data until this request is completed */
399 	for (i = 0; i < stream->outcnt; i++)
400 		SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
401 
402 	asoc->strreset_chunk = chunk;
403 	sctp_chunk_hold(asoc->strreset_chunk);
404 
405 	retval = sctp_send_reconf(asoc, chunk);
406 	if (retval) {
407 		sctp_chunk_put(asoc->strreset_chunk);
408 		asoc->strreset_chunk = NULL;
409 
410 		for (i = 0; i < stream->outcnt; i++)
411 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
412 
413 		return retval;
414 	}
415 
416 	asoc->strreset_outstanding = 1;
417 
418 	return 0;
419 }
420 
421 int sctp_send_add_streams(struct sctp_association *asoc,
422 			  struct sctp_add_streams *params)
423 {
424 	struct sctp_stream *stream = &asoc->stream;
425 	struct sctp_chunk *chunk = NULL;
426 	int retval;
427 	__u32 outcnt, incnt;
428 	__u16 out, in;
429 
430 	if (!asoc->peer.reconf_capable ||
431 	    !(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ)) {
432 		retval = -ENOPROTOOPT;
433 		goto out;
434 	}
435 
436 	if (asoc->strreset_outstanding) {
437 		retval = -EINPROGRESS;
438 		goto out;
439 	}
440 
441 	out = params->sas_outstrms;
442 	in  = params->sas_instrms;
443 	outcnt = stream->outcnt + out;
444 	incnt = stream->incnt + in;
445 	if (outcnt > SCTP_MAX_STREAM || incnt > SCTP_MAX_STREAM ||
446 	    (!out && !in)) {
447 		retval = -EINVAL;
448 		goto out;
449 	}
450 
451 	if (out) {
452 		retval = sctp_stream_alloc_out(stream, outcnt, GFP_KERNEL);
453 		if (retval)
454 			goto out;
455 	}
456 
457 	chunk = sctp_make_strreset_addstrm(asoc, out, in);
458 	if (!chunk) {
459 		retval = -ENOMEM;
460 		goto out;
461 	}
462 
463 	asoc->strreset_chunk = chunk;
464 	sctp_chunk_hold(asoc->strreset_chunk);
465 
466 	retval = sctp_send_reconf(asoc, chunk);
467 	if (retval) {
468 		sctp_chunk_put(asoc->strreset_chunk);
469 		asoc->strreset_chunk = NULL;
470 		goto out;
471 	}
472 
473 	asoc->strreset_outstanding = !!out + !!in;
474 
475 out:
476 	return retval;
477 }
478 
479 static struct sctp_paramhdr *sctp_chunk_lookup_strreset_param(
480 			struct sctp_association *asoc, __be32 resp_seq,
481 			__be16 type)
482 {
483 	struct sctp_chunk *chunk = asoc->strreset_chunk;
484 	struct sctp_reconf_chunk *hdr;
485 	union sctp_params param;
486 
487 	if (!chunk)
488 		return NULL;
489 
490 	hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
491 	sctp_walk_params(param, hdr, params) {
492 		/* sctp_strreset_tsnreq is actually the basic structure
493 		 * of all stream reconf params, so it's safe to use it
494 		 * to access request_seq.
495 		 */
496 		struct sctp_strreset_tsnreq *req = param.v;
497 
498 		if ((!resp_seq || req->request_seq == resp_seq) &&
499 		    (!type || type == req->param_hdr.type))
500 			return param.v;
501 	}
502 
503 	return NULL;
504 }
505 
506 static void sctp_update_strreset_result(struct sctp_association *asoc,
507 					__u32 result)
508 {
509 	asoc->strreset_result[1] = asoc->strreset_result[0];
510 	asoc->strreset_result[0] = result;
511 }
512 
513 struct sctp_chunk *sctp_process_strreset_outreq(
514 				struct sctp_association *asoc,
515 				union sctp_params param,
516 				struct sctp_ulpevent **evp)
517 {
518 	struct sctp_strreset_outreq *outreq = param.v;
519 	struct sctp_stream *stream = &asoc->stream;
520 	__u32 result = SCTP_STRRESET_DENIED;
521 	__be16 *str_p = NULL;
522 	__u32 request_seq;
523 	__u16 i, nums;
524 
525 	request_seq = ntohl(outreq->request_seq);
526 
527 	if (ntohl(outreq->send_reset_at_tsn) >
528 	    sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) {
529 		result = SCTP_STRRESET_IN_PROGRESS;
530 		goto err;
531 	}
532 
533 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
534 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
535 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
536 		goto err;
537 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
538 		i = asoc->strreset_inseq - request_seq - 1;
539 		result = asoc->strreset_result[i];
540 		goto err;
541 	}
542 	asoc->strreset_inseq++;
543 
544 	/* Check strreset_enable after inseq inc, as sender cannot tell
545 	 * the peer doesn't enable strreset after receiving response with
546 	 * result denied, as well as to keep consistent with bsd.
547 	 */
548 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
549 		goto out;
550 
551 	nums = (ntohs(param.p->length) - sizeof(*outreq)) / sizeof(__u16);
552 	str_p = outreq->list_of_streams;
553 	for (i = 0; i < nums; i++) {
554 		if (ntohs(str_p[i]) >= stream->incnt) {
555 			result = SCTP_STRRESET_ERR_WRONG_SSN;
556 			goto out;
557 		}
558 	}
559 
560 	if (asoc->strreset_chunk) {
561 		if (!sctp_chunk_lookup_strreset_param(
562 				asoc, outreq->response_seq,
563 				SCTP_PARAM_RESET_IN_REQUEST)) {
564 			/* same process with outstanding isn't 0 */
565 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
566 			goto out;
567 		}
568 
569 		asoc->strreset_outstanding--;
570 		asoc->strreset_outseq++;
571 
572 		if (!asoc->strreset_outstanding) {
573 			struct sctp_transport *t;
574 
575 			t = asoc->strreset_chunk->transport;
576 			if (del_timer(&t->reconf_timer))
577 				sctp_transport_put(t);
578 
579 			sctp_chunk_put(asoc->strreset_chunk);
580 			asoc->strreset_chunk = NULL;
581 		}
582 	}
583 
584 	if (nums)
585 		for (i = 0; i < nums; i++)
586 			SCTP_SI(stream, ntohs(str_p[i]))->mid = 0;
587 	else
588 		for (i = 0; i < stream->incnt; i++)
589 			SCTP_SI(stream, i)->mid = 0;
590 
591 	result = SCTP_STRRESET_PERFORMED;
592 
593 	*evp = sctp_ulpevent_make_stream_reset_event(asoc,
594 		SCTP_STREAM_RESET_INCOMING_SSN, nums, str_p, GFP_ATOMIC);
595 
596 out:
597 	sctp_update_strreset_result(asoc, result);
598 err:
599 	return sctp_make_strreset_resp(asoc, result, request_seq);
600 }
601 
602 struct sctp_chunk *sctp_process_strreset_inreq(
603 				struct sctp_association *asoc,
604 				union sctp_params param,
605 				struct sctp_ulpevent **evp)
606 {
607 	struct sctp_strreset_inreq *inreq = param.v;
608 	struct sctp_stream *stream = &asoc->stream;
609 	__u32 result = SCTP_STRRESET_DENIED;
610 	struct sctp_chunk *chunk = NULL;
611 	__u32 request_seq;
612 	__u16 i, nums;
613 	__be16 *str_p;
614 
615 	request_seq = ntohl(inreq->request_seq);
616 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
617 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
618 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
619 		goto err;
620 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
621 		i = asoc->strreset_inseq - request_seq - 1;
622 		result = asoc->strreset_result[i];
623 		if (result == SCTP_STRRESET_PERFORMED)
624 			return NULL;
625 		goto err;
626 	}
627 	asoc->strreset_inseq++;
628 
629 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
630 		goto out;
631 
632 	if (asoc->strreset_outstanding) {
633 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
634 		goto out;
635 	}
636 
637 	nums = (ntohs(param.p->length) - sizeof(*inreq)) / sizeof(__u16);
638 	str_p = inreq->list_of_streams;
639 	for (i = 0; i < nums; i++) {
640 		if (ntohs(str_p[i]) >= stream->outcnt) {
641 			result = SCTP_STRRESET_ERR_WRONG_SSN;
642 			goto out;
643 		}
644 	}
645 
646 	if (!sctp_stream_outq_is_empty(stream, nums, str_p)) {
647 		result = SCTP_STRRESET_IN_PROGRESS;
648 		asoc->strreset_inseq--;
649 		goto err;
650 	}
651 
652 	chunk = sctp_make_strreset_req(asoc, nums, str_p, 1, 0);
653 	if (!chunk)
654 		goto out;
655 
656 	if (nums)
657 		for (i = 0; i < nums; i++)
658 			SCTP_SO(stream, ntohs(str_p[i]))->state =
659 					       SCTP_STREAM_CLOSED;
660 	else
661 		for (i = 0; i < stream->outcnt; i++)
662 			SCTP_SO(stream, i)->state = SCTP_STREAM_CLOSED;
663 
664 	asoc->strreset_chunk = chunk;
665 	asoc->strreset_outstanding = 1;
666 	sctp_chunk_hold(asoc->strreset_chunk);
667 
668 	result = SCTP_STRRESET_PERFORMED;
669 
670 out:
671 	sctp_update_strreset_result(asoc, result);
672 err:
673 	if (!chunk)
674 		chunk =  sctp_make_strreset_resp(asoc, result, request_seq);
675 
676 	return chunk;
677 }
678 
679 struct sctp_chunk *sctp_process_strreset_tsnreq(
680 				struct sctp_association *asoc,
681 				union sctp_params param,
682 				struct sctp_ulpevent **evp)
683 {
684 	__u32 init_tsn = 0, next_tsn = 0, max_tsn_seen;
685 	struct sctp_strreset_tsnreq *tsnreq = param.v;
686 	struct sctp_stream *stream = &asoc->stream;
687 	__u32 result = SCTP_STRRESET_DENIED;
688 	__u32 request_seq;
689 	__u16 i;
690 
691 	request_seq = ntohl(tsnreq->request_seq);
692 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
693 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
694 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
695 		goto err;
696 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
697 		i = asoc->strreset_inseq - request_seq - 1;
698 		result = asoc->strreset_result[i];
699 		if (result == SCTP_STRRESET_PERFORMED) {
700 			next_tsn = asoc->ctsn_ack_point + 1;
701 			init_tsn =
702 				sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1;
703 		}
704 		goto err;
705 	}
706 
707 	if (!sctp_outq_is_empty(&asoc->outqueue)) {
708 		result = SCTP_STRRESET_IN_PROGRESS;
709 		goto err;
710 	}
711 
712 	asoc->strreset_inseq++;
713 
714 	if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
715 		goto out;
716 
717 	if (asoc->strreset_outstanding) {
718 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
719 		goto out;
720 	}
721 
722 	/* G4: The same processing as though a FWD-TSN chunk (as defined in
723 	 *     [RFC3758]) with all streams affected and a new cumulative TSN
724 	 *     ACK of the Receiver's Next TSN minus 1 were received MUST be
725 	 *     performed.
726 	 */
727 	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
728 	asoc->stream.si->report_ftsn(&asoc->ulpq, max_tsn_seen);
729 
730 	/* G1: Compute an appropriate value for the Receiver's Next TSN -- the
731 	 *     TSN that the peer should use to send the next DATA chunk.  The
732 	 *     value SHOULD be the smallest TSN not acknowledged by the
733 	 *     receiver of the request plus 2^31.
734 	 */
735 	init_tsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + (1 << 31);
736 	sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
737 			 init_tsn, GFP_ATOMIC);
738 
739 	/* G3: The same processing as though a SACK chunk with no gap report
740 	 *     and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
741 	 *     received MUST be performed.
742 	 */
743 	sctp_outq_free(&asoc->outqueue);
744 
745 	/* G2: Compute an appropriate value for the local endpoint's next TSN,
746 	 *     i.e., the next TSN assigned by the receiver of the SSN/TSN reset
747 	 *     chunk.  The value SHOULD be the highest TSN sent by the receiver
748 	 *     of the request plus 1.
749 	 */
750 	next_tsn = asoc->next_tsn;
751 	asoc->ctsn_ack_point = next_tsn - 1;
752 	asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
753 
754 	/* G5:  The next expected and outgoing SSNs MUST be reset to 0 for all
755 	 *      incoming and outgoing streams.
756 	 */
757 	for (i = 0; i < stream->outcnt; i++) {
758 		SCTP_SO(stream, i)->mid = 0;
759 		SCTP_SO(stream, i)->mid_uo = 0;
760 	}
761 	for (i = 0; i < stream->incnt; i++)
762 		SCTP_SI(stream, i)->mid = 0;
763 
764 	result = SCTP_STRRESET_PERFORMED;
765 
766 	*evp = sctp_ulpevent_make_assoc_reset_event(asoc, 0, init_tsn,
767 						    next_tsn, GFP_ATOMIC);
768 
769 out:
770 	sctp_update_strreset_result(asoc, result);
771 err:
772 	return sctp_make_strreset_tsnresp(asoc, result, request_seq,
773 					  next_tsn, init_tsn);
774 }
775 
776 struct sctp_chunk *sctp_process_strreset_addstrm_out(
777 				struct sctp_association *asoc,
778 				union sctp_params param,
779 				struct sctp_ulpevent **evp)
780 {
781 	struct sctp_strreset_addstrm *addstrm = param.v;
782 	struct sctp_stream *stream = &asoc->stream;
783 	__u32 result = SCTP_STRRESET_DENIED;
784 	__u32 request_seq, incnt;
785 	__u16 in, i;
786 
787 	request_seq = ntohl(addstrm->request_seq);
788 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
789 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
790 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
791 		goto err;
792 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
793 		i = asoc->strreset_inseq - request_seq - 1;
794 		result = asoc->strreset_result[i];
795 		goto err;
796 	}
797 	asoc->strreset_inseq++;
798 
799 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
800 		goto out;
801 
802 	in = ntohs(addstrm->number_of_streams);
803 	incnt = stream->incnt + in;
804 	if (!in || incnt > SCTP_MAX_STREAM)
805 		goto out;
806 
807 	if (sctp_stream_alloc_in(stream, incnt, GFP_ATOMIC))
808 		goto out;
809 
810 	if (asoc->strreset_chunk) {
811 		if (!sctp_chunk_lookup_strreset_param(
812 			asoc, 0, SCTP_PARAM_RESET_ADD_IN_STREAMS)) {
813 			/* same process with outstanding isn't 0 */
814 			result = SCTP_STRRESET_ERR_IN_PROGRESS;
815 			goto out;
816 		}
817 
818 		asoc->strreset_outstanding--;
819 		asoc->strreset_outseq++;
820 
821 		if (!asoc->strreset_outstanding) {
822 			struct sctp_transport *t;
823 
824 			t = asoc->strreset_chunk->transport;
825 			if (del_timer(&t->reconf_timer))
826 				sctp_transport_put(t);
827 
828 			sctp_chunk_put(asoc->strreset_chunk);
829 			asoc->strreset_chunk = NULL;
830 		}
831 	}
832 
833 	stream->incnt = incnt;
834 
835 	result = SCTP_STRRESET_PERFORMED;
836 
837 	*evp = sctp_ulpevent_make_stream_change_event(asoc,
838 		0, ntohs(addstrm->number_of_streams), 0, GFP_ATOMIC);
839 
840 out:
841 	sctp_update_strreset_result(asoc, result);
842 err:
843 	return sctp_make_strreset_resp(asoc, result, request_seq);
844 }
845 
846 struct sctp_chunk *sctp_process_strreset_addstrm_in(
847 				struct sctp_association *asoc,
848 				union sctp_params param,
849 				struct sctp_ulpevent **evp)
850 {
851 	struct sctp_strreset_addstrm *addstrm = param.v;
852 	struct sctp_stream *stream = &asoc->stream;
853 	__u32 result = SCTP_STRRESET_DENIED;
854 	struct sctp_chunk *chunk = NULL;
855 	__u32 request_seq, outcnt;
856 	__u16 out, i;
857 	int ret;
858 
859 	request_seq = ntohl(addstrm->request_seq);
860 	if (TSN_lt(asoc->strreset_inseq, request_seq) ||
861 	    TSN_lt(request_seq, asoc->strreset_inseq - 2)) {
862 		result = SCTP_STRRESET_ERR_BAD_SEQNO;
863 		goto err;
864 	} else if (TSN_lt(request_seq, asoc->strreset_inseq)) {
865 		i = asoc->strreset_inseq - request_seq - 1;
866 		result = asoc->strreset_result[i];
867 		if (result == SCTP_STRRESET_PERFORMED)
868 			return NULL;
869 		goto err;
870 	}
871 	asoc->strreset_inseq++;
872 
873 	if (!(asoc->strreset_enable & SCTP_ENABLE_CHANGE_ASSOC_REQ))
874 		goto out;
875 
876 	if (asoc->strreset_outstanding) {
877 		result = SCTP_STRRESET_ERR_IN_PROGRESS;
878 		goto out;
879 	}
880 
881 	out = ntohs(addstrm->number_of_streams);
882 	outcnt = stream->outcnt + out;
883 	if (!out || outcnt > SCTP_MAX_STREAM)
884 		goto out;
885 
886 	ret = sctp_stream_alloc_out(stream, outcnt, GFP_ATOMIC);
887 	if (ret)
888 		goto out;
889 
890 	chunk = sctp_make_strreset_addstrm(asoc, out, 0);
891 	if (!chunk)
892 		goto out;
893 
894 	asoc->strreset_chunk = chunk;
895 	asoc->strreset_outstanding = 1;
896 	sctp_chunk_hold(asoc->strreset_chunk);
897 
898 	stream->outcnt = outcnt;
899 
900 	result = SCTP_STRRESET_PERFORMED;
901 
902 out:
903 	sctp_update_strreset_result(asoc, result);
904 err:
905 	if (!chunk)
906 		chunk = sctp_make_strreset_resp(asoc, result, request_seq);
907 
908 	return chunk;
909 }
910 
911 struct sctp_chunk *sctp_process_strreset_resp(
912 				struct sctp_association *asoc,
913 				union sctp_params param,
914 				struct sctp_ulpevent **evp)
915 {
916 	struct sctp_stream *stream = &asoc->stream;
917 	struct sctp_strreset_resp *resp = param.v;
918 	struct sctp_transport *t;
919 	__u16 i, nums, flags = 0;
920 	struct sctp_paramhdr *req;
921 	__u32 result;
922 
923 	req = sctp_chunk_lookup_strreset_param(asoc, resp->response_seq, 0);
924 	if (!req)
925 		return NULL;
926 
927 	result = ntohl(resp->result);
928 	if (result != SCTP_STRRESET_PERFORMED) {
929 		/* if in progress, do nothing but retransmit */
930 		if (result == SCTP_STRRESET_IN_PROGRESS)
931 			return NULL;
932 		else if (result == SCTP_STRRESET_DENIED)
933 			flags = SCTP_STREAM_RESET_DENIED;
934 		else
935 			flags = SCTP_STREAM_RESET_FAILED;
936 	}
937 
938 	if (req->type == SCTP_PARAM_RESET_OUT_REQUEST) {
939 		struct sctp_strreset_outreq *outreq;
940 		__be16 *str_p;
941 
942 		outreq = (struct sctp_strreset_outreq *)req;
943 		str_p = outreq->list_of_streams;
944 		nums = (ntohs(outreq->param_hdr.length) - sizeof(*outreq)) /
945 		       sizeof(__u16);
946 
947 		if (result == SCTP_STRRESET_PERFORMED) {
948 			struct sctp_stream_out *sout;
949 			if (nums) {
950 				for (i = 0; i < nums; i++) {
951 					sout = SCTP_SO(stream, ntohs(str_p[i]));
952 					sout->mid = 0;
953 					sout->mid_uo = 0;
954 				}
955 			} else {
956 				for (i = 0; i < stream->outcnt; i++) {
957 					sout = SCTP_SO(stream, i);
958 					sout->mid = 0;
959 					sout->mid_uo = 0;
960 				}
961 			}
962 		}
963 
964 		flags |= SCTP_STREAM_RESET_OUTGOING_SSN;
965 
966 		for (i = 0; i < stream->outcnt; i++)
967 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
968 
969 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
970 			nums, str_p, GFP_ATOMIC);
971 	} else if (req->type == SCTP_PARAM_RESET_IN_REQUEST) {
972 		struct sctp_strreset_inreq *inreq;
973 		__be16 *str_p;
974 
975 		/* if the result is performed, it's impossible for inreq */
976 		if (result == SCTP_STRRESET_PERFORMED)
977 			return NULL;
978 
979 		inreq = (struct sctp_strreset_inreq *)req;
980 		str_p = inreq->list_of_streams;
981 		nums = (ntohs(inreq->param_hdr.length) - sizeof(*inreq)) /
982 		       sizeof(__u16);
983 
984 		flags |= SCTP_STREAM_RESET_INCOMING_SSN;
985 
986 		*evp = sctp_ulpevent_make_stream_reset_event(asoc, flags,
987 			nums, str_p, GFP_ATOMIC);
988 	} else if (req->type == SCTP_PARAM_RESET_TSN_REQUEST) {
989 		struct sctp_strreset_resptsn *resptsn;
990 		__u32 stsn, rtsn;
991 
992 		/* check for resptsn, as sctp_verify_reconf didn't do it*/
993 		if (ntohs(param.p->length) != sizeof(*resptsn))
994 			return NULL;
995 
996 		resptsn = (struct sctp_strreset_resptsn *)resp;
997 		stsn = ntohl(resptsn->senders_next_tsn);
998 		rtsn = ntohl(resptsn->receivers_next_tsn);
999 
1000 		if (result == SCTP_STRRESET_PERFORMED) {
1001 			__u32 mtsn = sctp_tsnmap_get_max_tsn_seen(
1002 						&asoc->peer.tsn_map);
1003 			LIST_HEAD(temp);
1004 
1005 			asoc->stream.si->report_ftsn(&asoc->ulpq, mtsn);
1006 
1007 			sctp_tsnmap_init(&asoc->peer.tsn_map,
1008 					 SCTP_TSN_MAP_INITIAL,
1009 					 stsn, GFP_ATOMIC);
1010 
1011 			/* Clean up sacked and abandoned queues only. As the
1012 			 * out_chunk_list may not be empty, splice it to temp,
1013 			 * then get it back after sctp_outq_free is done.
1014 			 */
1015 			list_splice_init(&asoc->outqueue.out_chunk_list, &temp);
1016 			sctp_outq_free(&asoc->outqueue);
1017 			list_splice_init(&temp, &asoc->outqueue.out_chunk_list);
1018 
1019 			asoc->next_tsn = rtsn;
1020 			asoc->ctsn_ack_point = asoc->next_tsn - 1;
1021 			asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1022 
1023 			for (i = 0; i < stream->outcnt; i++) {
1024 				SCTP_SO(stream, i)->mid = 0;
1025 				SCTP_SO(stream, i)->mid_uo = 0;
1026 			}
1027 			for (i = 0; i < stream->incnt; i++)
1028 				SCTP_SI(stream, i)->mid = 0;
1029 		}
1030 
1031 		for (i = 0; i < stream->outcnt; i++)
1032 			SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1033 
1034 		*evp = sctp_ulpevent_make_assoc_reset_event(asoc, flags,
1035 			stsn, rtsn, GFP_ATOMIC);
1036 	} else if (req->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS) {
1037 		struct sctp_strreset_addstrm *addstrm;
1038 		__u16 number;
1039 
1040 		addstrm = (struct sctp_strreset_addstrm *)req;
1041 		nums = ntohs(addstrm->number_of_streams);
1042 		number = stream->outcnt - nums;
1043 
1044 		if (result == SCTP_STRRESET_PERFORMED)
1045 			for (i = number; i < stream->outcnt; i++)
1046 				SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;
1047 		else
1048 			stream->outcnt = number;
1049 
1050 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1051 			0, nums, GFP_ATOMIC);
1052 	} else if (req->type == SCTP_PARAM_RESET_ADD_IN_STREAMS) {
1053 		struct sctp_strreset_addstrm *addstrm;
1054 
1055 		/* if the result is performed, it's impossible for addstrm in
1056 		 * request.
1057 		 */
1058 		if (result == SCTP_STRRESET_PERFORMED)
1059 			return NULL;
1060 
1061 		addstrm = (struct sctp_strreset_addstrm *)req;
1062 		nums = ntohs(addstrm->number_of_streams);
1063 
1064 		*evp = sctp_ulpevent_make_stream_change_event(asoc, flags,
1065 			nums, 0, GFP_ATOMIC);
1066 	}
1067 
1068 	asoc->strreset_outstanding--;
1069 	asoc->strreset_outseq++;
1070 
1071 	/* remove everything for this reconf request */
1072 	if (!asoc->strreset_outstanding) {
1073 		t = asoc->strreset_chunk->transport;
1074 		if (del_timer(&t->reconf_timer))
1075 			sctp_transport_put(t);
1076 
1077 		sctp_chunk_put(asoc->strreset_chunk);
1078 		asoc->strreset_chunk = NULL;
1079 	}
1080 
1081 	return NULL;
1082 }
1083