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