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[thirdparty/kernel/linux.git] / net / bluetooth / l2cap_core.c
1 /*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2000-2001 Qualcomm Incorporated
4 Copyright (C) 2009-2010 Gustavo F. Padovan <gustavo@padovan.org>
5 Copyright (C) 2010 Google Inc.
6 Copyright (C) 2011 ProFUSION Embedded Systems
7 Copyright (c) 2012 Code Aurora Forum. All rights reserved.
8
9 Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
10
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License version 2 as
13 published by the Free Software Foundation;
14
15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
16 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
18 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
19 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
20 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
21 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
22 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23
24 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
25 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
26 SOFTWARE IS DISCLAIMED.
27 */
28
29 /* Bluetooth L2CAP core. */
30
31 #include <linux/module.h>
32
33 #include <linux/debugfs.h>
34 #include <linux/crc16.h>
35 #include <linux/filter.h>
36
37 #include <net/bluetooth/bluetooth.h>
38 #include <net/bluetooth/hci_core.h>
39 #include <net/bluetooth/l2cap.h>
40
41 #include "smp.h"
42
43 #define LE_FLOWCTL_MAX_CREDITS 65535
44
45 bool disable_ertm;
46 bool enable_ecred = IS_ENABLED(CONFIG_BT_LE_L2CAP_ECRED);
47
48 static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN | L2CAP_FEAT_UCD;
49
50 static LIST_HEAD(chan_list);
51 static DEFINE_RWLOCK(chan_list_lock);
52
53 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
54 u8 code, u8 ident, u16 dlen, void *data);
55 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
56 void *data);
57 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size);
58 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err);
59
60 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
61 struct sk_buff_head *skbs, u8 event);
62 static void l2cap_retrans_timeout(struct work_struct *work);
63 static void l2cap_monitor_timeout(struct work_struct *work);
64 static void l2cap_ack_timeout(struct work_struct *work);
65
66 static inline u8 bdaddr_type(u8 link_type, u8 bdaddr_type)
67 {
68 if (link_type == LE_LINK) {
69 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
70 return BDADDR_LE_PUBLIC;
71 else
72 return BDADDR_LE_RANDOM;
73 }
74
75 return BDADDR_BREDR;
76 }
77
78 static inline u8 bdaddr_src_type(struct hci_conn *hcon)
79 {
80 return bdaddr_type(hcon->type, hcon->src_type);
81 }
82
83 static inline u8 bdaddr_dst_type(struct hci_conn *hcon)
84 {
85 return bdaddr_type(hcon->type, hcon->dst_type);
86 }
87
88 /* ---- L2CAP channels ---- */
89
90 static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
91 u16 cid)
92 {
93 struct l2cap_chan *c;
94
95 list_for_each_entry(c, &conn->chan_l, list) {
96 if (c->dcid == cid)
97 return c;
98 }
99 return NULL;
100 }
101
102 static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn,
103 u16 cid)
104 {
105 struct l2cap_chan *c;
106
107 list_for_each_entry(c, &conn->chan_l, list) {
108 if (c->scid == cid)
109 return c;
110 }
111 return NULL;
112 }
113
114 /* Find channel with given SCID.
115 * Returns a reference locked channel.
116 */
117 static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn,
118 u16 cid)
119 {
120 struct l2cap_chan *c;
121
122 mutex_lock(&conn->chan_lock);
123 c = __l2cap_get_chan_by_scid(conn, cid);
124 if (c) {
125 /* Only lock if chan reference is not 0 */
126 c = l2cap_chan_hold_unless_zero(c);
127 if (c)
128 l2cap_chan_lock(c);
129 }
130 mutex_unlock(&conn->chan_lock);
131
132 return c;
133 }
134
135 /* Find channel with given DCID.
136 * Returns a reference locked channel.
137 */
138 static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
139 u16 cid)
140 {
141 struct l2cap_chan *c;
142
143 mutex_lock(&conn->chan_lock);
144 c = __l2cap_get_chan_by_dcid(conn, cid);
145 if (c) {
146 /* Only lock if chan reference is not 0 */
147 c = l2cap_chan_hold_unless_zero(c);
148 if (c)
149 l2cap_chan_lock(c);
150 }
151 mutex_unlock(&conn->chan_lock);
152
153 return c;
154 }
155
156 static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn,
157 u8 ident)
158 {
159 struct l2cap_chan *c;
160
161 list_for_each_entry(c, &conn->chan_l, list) {
162 if (c->ident == ident)
163 return c;
164 }
165 return NULL;
166 }
167
168 static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src,
169 u8 src_type)
170 {
171 struct l2cap_chan *c;
172
173 list_for_each_entry(c, &chan_list, global_l) {
174 if (src_type == BDADDR_BREDR && c->src_type != BDADDR_BREDR)
175 continue;
176
177 if (src_type != BDADDR_BREDR && c->src_type == BDADDR_BREDR)
178 continue;
179
180 if (c->sport == psm && !bacmp(&c->src, src))
181 return c;
182 }
183 return NULL;
184 }
185
186 int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm)
187 {
188 int err;
189
190 write_lock(&chan_list_lock);
191
192 if (psm && __l2cap_global_chan_by_addr(psm, src, chan->src_type)) {
193 err = -EADDRINUSE;
194 goto done;
195 }
196
197 if (psm) {
198 chan->psm = psm;
199 chan->sport = psm;
200 err = 0;
201 } else {
202 u16 p, start, end, incr;
203
204 if (chan->src_type == BDADDR_BREDR) {
205 start = L2CAP_PSM_DYN_START;
206 end = L2CAP_PSM_AUTO_END;
207 incr = 2;
208 } else {
209 start = L2CAP_PSM_LE_DYN_START;
210 end = L2CAP_PSM_LE_DYN_END;
211 incr = 1;
212 }
213
214 err = -EINVAL;
215 for (p = start; p <= end; p += incr)
216 if (!__l2cap_global_chan_by_addr(cpu_to_le16(p), src,
217 chan->src_type)) {
218 chan->psm = cpu_to_le16(p);
219 chan->sport = cpu_to_le16(p);
220 err = 0;
221 break;
222 }
223 }
224
225 done:
226 write_unlock(&chan_list_lock);
227 return err;
228 }
229 EXPORT_SYMBOL_GPL(l2cap_add_psm);
230
231 int l2cap_add_scid(struct l2cap_chan *chan, __u16 scid)
232 {
233 write_lock(&chan_list_lock);
234
235 /* Override the defaults (which are for conn-oriented) */
236 chan->omtu = L2CAP_DEFAULT_MTU;
237 chan->chan_type = L2CAP_CHAN_FIXED;
238
239 chan->scid = scid;
240
241 write_unlock(&chan_list_lock);
242
243 return 0;
244 }
245
246 static u16 l2cap_alloc_cid(struct l2cap_conn *conn)
247 {
248 u16 cid, dyn_end;
249
250 if (conn->hcon->type == LE_LINK)
251 dyn_end = L2CAP_CID_LE_DYN_END;
252 else
253 dyn_end = L2CAP_CID_DYN_END;
254
255 for (cid = L2CAP_CID_DYN_START; cid <= dyn_end; cid++) {
256 if (!__l2cap_get_chan_by_scid(conn, cid))
257 return cid;
258 }
259
260 return 0;
261 }
262
263 static void l2cap_state_change(struct l2cap_chan *chan, int state)
264 {
265 BT_DBG("chan %p %s -> %s", chan, state_to_string(chan->state),
266 state_to_string(state));
267
268 chan->state = state;
269 chan->ops->state_change(chan, state, 0);
270 }
271
272 static inline void l2cap_state_change_and_error(struct l2cap_chan *chan,
273 int state, int err)
274 {
275 chan->state = state;
276 chan->ops->state_change(chan, chan->state, err);
277 }
278
279 static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
280 {
281 chan->ops->state_change(chan, chan->state, err);
282 }
283
284 static void __set_retrans_timer(struct l2cap_chan *chan)
285 {
286 if (!delayed_work_pending(&chan->monitor_timer) &&
287 chan->retrans_timeout) {
288 l2cap_set_timer(chan, &chan->retrans_timer,
289 msecs_to_jiffies(chan->retrans_timeout));
290 }
291 }
292
293 static void __set_monitor_timer(struct l2cap_chan *chan)
294 {
295 __clear_retrans_timer(chan);
296 if (chan->monitor_timeout) {
297 l2cap_set_timer(chan, &chan->monitor_timer,
298 msecs_to_jiffies(chan->monitor_timeout));
299 }
300 }
301
302 static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head,
303 u16 seq)
304 {
305 struct sk_buff *skb;
306
307 skb_queue_walk(head, skb) {
308 if (bt_cb(skb)->l2cap.txseq == seq)
309 return skb;
310 }
311
312 return NULL;
313 }
314
315 /* ---- L2CAP sequence number lists ---- */
316
317 /* For ERTM, ordered lists of sequence numbers must be tracked for
318 * SREJ requests that are received and for frames that are to be
319 * retransmitted. These seq_list functions implement a singly-linked
320 * list in an array, where membership in the list can also be checked
321 * in constant time. Items can also be added to the tail of the list
322 * and removed from the head in constant time, without further memory
323 * allocs or frees.
324 */
325
326 static int l2cap_seq_list_init(struct l2cap_seq_list *seq_list, u16 size)
327 {
328 size_t alloc_size, i;
329
330 /* Allocated size is a power of 2 to map sequence numbers
331 * (which may be up to 14 bits) in to a smaller array that is
332 * sized for the negotiated ERTM transmit windows.
333 */
334 alloc_size = roundup_pow_of_two(size);
335
336 seq_list->list = kmalloc_array(alloc_size, sizeof(u16), GFP_KERNEL);
337 if (!seq_list->list)
338 return -ENOMEM;
339
340 seq_list->mask = alloc_size - 1;
341 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
342 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
343 for (i = 0; i < alloc_size; i++)
344 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
345
346 return 0;
347 }
348
349 static inline void l2cap_seq_list_free(struct l2cap_seq_list *seq_list)
350 {
351 kfree(seq_list->list);
352 }
353
354 static inline bool l2cap_seq_list_contains(struct l2cap_seq_list *seq_list,
355 u16 seq)
356 {
357 /* Constant-time check for list membership */
358 return seq_list->list[seq & seq_list->mask] != L2CAP_SEQ_LIST_CLEAR;
359 }
360
361 static inline u16 l2cap_seq_list_pop(struct l2cap_seq_list *seq_list)
362 {
363 u16 seq = seq_list->head;
364 u16 mask = seq_list->mask;
365
366 seq_list->head = seq_list->list[seq & mask];
367 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_CLEAR;
368
369 if (seq_list->head == L2CAP_SEQ_LIST_TAIL) {
370 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
371 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
372 }
373
374 return seq;
375 }
376
377 static void l2cap_seq_list_clear(struct l2cap_seq_list *seq_list)
378 {
379 u16 i;
380
381 if (seq_list->head == L2CAP_SEQ_LIST_CLEAR)
382 return;
383
384 for (i = 0; i <= seq_list->mask; i++)
385 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
386
387 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
388 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
389 }
390
391 static void l2cap_seq_list_append(struct l2cap_seq_list *seq_list, u16 seq)
392 {
393 u16 mask = seq_list->mask;
394
395 /* All appends happen in constant time */
396
397 if (seq_list->list[seq & mask] != L2CAP_SEQ_LIST_CLEAR)
398 return;
399
400 if (seq_list->tail == L2CAP_SEQ_LIST_CLEAR)
401 seq_list->head = seq;
402 else
403 seq_list->list[seq_list->tail & mask] = seq;
404
405 seq_list->tail = seq;
406 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_TAIL;
407 }
408
409 static void l2cap_chan_timeout(struct work_struct *work)
410 {
411 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
412 chan_timer.work);
413 struct l2cap_conn *conn = chan->conn;
414 int reason;
415
416 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
417
418 if (!conn)
419 return;
420
421 mutex_lock(&conn->chan_lock);
422 /* __set_chan_timer() calls l2cap_chan_hold(chan) while scheduling
423 * this work. No need to call l2cap_chan_hold(chan) here again.
424 */
425 l2cap_chan_lock(chan);
426
427 if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
428 reason = ECONNREFUSED;
429 else if (chan->state == BT_CONNECT &&
430 chan->sec_level != BT_SECURITY_SDP)
431 reason = ECONNREFUSED;
432 else
433 reason = ETIMEDOUT;
434
435 l2cap_chan_close(chan, reason);
436
437 chan->ops->close(chan);
438
439 l2cap_chan_unlock(chan);
440 l2cap_chan_put(chan);
441
442 mutex_unlock(&conn->chan_lock);
443 }
444
445 struct l2cap_chan *l2cap_chan_create(void)
446 {
447 struct l2cap_chan *chan;
448
449 chan = kzalloc(sizeof(*chan), GFP_ATOMIC);
450 if (!chan)
451 return NULL;
452
453 skb_queue_head_init(&chan->tx_q);
454 skb_queue_head_init(&chan->srej_q);
455 mutex_init(&chan->lock);
456
457 /* Set default lock nesting level */
458 atomic_set(&chan->nesting, L2CAP_NESTING_NORMAL);
459
460 /* Available receive buffer space is initially unknown */
461 chan->rx_avail = -1;
462
463 write_lock(&chan_list_lock);
464 list_add(&chan->global_l, &chan_list);
465 write_unlock(&chan_list_lock);
466
467 INIT_DELAYED_WORK(&chan->chan_timer, l2cap_chan_timeout);
468 INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout);
469 INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout);
470 INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout);
471
472 chan->state = BT_OPEN;
473
474 kref_init(&chan->kref);
475
476 /* This flag is cleared in l2cap_chan_ready() */
477 set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
478
479 BT_DBG("chan %p", chan);
480
481 return chan;
482 }
483 EXPORT_SYMBOL_GPL(l2cap_chan_create);
484
485 static void l2cap_chan_destroy(struct kref *kref)
486 {
487 struct l2cap_chan *chan = container_of(kref, struct l2cap_chan, kref);
488
489 BT_DBG("chan %p", chan);
490
491 write_lock(&chan_list_lock);
492 list_del(&chan->global_l);
493 write_unlock(&chan_list_lock);
494
495 kfree(chan);
496 }
497
498 void l2cap_chan_hold(struct l2cap_chan *c)
499 {
500 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
501
502 kref_get(&c->kref);
503 }
504
505 struct l2cap_chan *l2cap_chan_hold_unless_zero(struct l2cap_chan *c)
506 {
507 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
508
509 if (!kref_get_unless_zero(&c->kref))
510 return NULL;
511
512 return c;
513 }
514
515 void l2cap_chan_put(struct l2cap_chan *c)
516 {
517 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
518
519 kref_put(&c->kref, l2cap_chan_destroy);
520 }
521 EXPORT_SYMBOL_GPL(l2cap_chan_put);
522
523 void l2cap_chan_set_defaults(struct l2cap_chan *chan)
524 {
525 chan->fcs = L2CAP_FCS_CRC16;
526 chan->max_tx = L2CAP_DEFAULT_MAX_TX;
527 chan->tx_win = L2CAP_DEFAULT_TX_WINDOW;
528 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
529 chan->remote_max_tx = chan->max_tx;
530 chan->remote_tx_win = chan->tx_win;
531 chan->ack_win = L2CAP_DEFAULT_TX_WINDOW;
532 chan->sec_level = BT_SECURITY_LOW;
533 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
534 chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO;
535 chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO;
536
537 chan->conf_state = 0;
538 set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
539
540 set_bit(FLAG_FORCE_ACTIVE, &chan->flags);
541 }
542 EXPORT_SYMBOL_GPL(l2cap_chan_set_defaults);
543
544 static __u16 l2cap_le_rx_credits(struct l2cap_chan *chan)
545 {
546 size_t sdu_len = chan->sdu ? chan->sdu->len : 0;
547
548 if (chan->mps == 0)
549 return 0;
550
551 /* If we don't know the available space in the receiver buffer, give
552 * enough credits for a full packet.
553 */
554 if (chan->rx_avail == -1)
555 return (chan->imtu / chan->mps) + 1;
556
557 /* If we know how much space is available in the receive buffer, give
558 * out as many credits as would fill the buffer.
559 */
560 if (chan->rx_avail <= sdu_len)
561 return 0;
562
563 return DIV_ROUND_UP(chan->rx_avail - sdu_len, chan->mps);
564 }
565
566 static void l2cap_le_flowctl_init(struct l2cap_chan *chan, u16 tx_credits)
567 {
568 chan->sdu = NULL;
569 chan->sdu_last_frag = NULL;
570 chan->sdu_len = 0;
571 chan->tx_credits = tx_credits;
572 /* Derive MPS from connection MTU to stop HCI fragmentation */
573 chan->mps = min_t(u16, chan->imtu, chan->conn->mtu - L2CAP_HDR_SIZE);
574 chan->rx_credits = l2cap_le_rx_credits(chan);
575
576 skb_queue_head_init(&chan->tx_q);
577 }
578
579 static void l2cap_ecred_init(struct l2cap_chan *chan, u16 tx_credits)
580 {
581 l2cap_le_flowctl_init(chan, tx_credits);
582
583 /* L2CAP implementations shall support a minimum MPS of 64 octets */
584 if (chan->mps < L2CAP_ECRED_MIN_MPS) {
585 chan->mps = L2CAP_ECRED_MIN_MPS;
586 chan->rx_credits = l2cap_le_rx_credits(chan);
587 }
588 }
589
590 void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
591 {
592 BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn,
593 __le16_to_cpu(chan->psm), chan->dcid);
594
595 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
596
597 chan->conn = conn;
598
599 switch (chan->chan_type) {
600 case L2CAP_CHAN_CONN_ORIENTED:
601 /* Alloc CID for connection-oriented socket */
602 chan->scid = l2cap_alloc_cid(conn);
603 if (conn->hcon->type == ACL_LINK)
604 chan->omtu = L2CAP_DEFAULT_MTU;
605 break;
606
607 case L2CAP_CHAN_CONN_LESS:
608 /* Connectionless socket */
609 chan->scid = L2CAP_CID_CONN_LESS;
610 chan->dcid = L2CAP_CID_CONN_LESS;
611 chan->omtu = L2CAP_DEFAULT_MTU;
612 break;
613
614 case L2CAP_CHAN_FIXED:
615 /* Caller will set CID and CID specific MTU values */
616 break;
617
618 default:
619 /* Raw socket can send/recv signalling messages only */
620 chan->scid = L2CAP_CID_SIGNALING;
621 chan->dcid = L2CAP_CID_SIGNALING;
622 chan->omtu = L2CAP_DEFAULT_MTU;
623 }
624
625 chan->local_id = L2CAP_BESTEFFORT_ID;
626 chan->local_stype = L2CAP_SERV_BESTEFFORT;
627 chan->local_msdu = L2CAP_DEFAULT_MAX_SDU_SIZE;
628 chan->local_sdu_itime = L2CAP_DEFAULT_SDU_ITIME;
629 chan->local_acc_lat = L2CAP_DEFAULT_ACC_LAT;
630 chan->local_flush_to = L2CAP_EFS_DEFAULT_FLUSH_TO;
631
632 l2cap_chan_hold(chan);
633
634 /* Only keep a reference for fixed channels if they requested it */
635 if (chan->chan_type != L2CAP_CHAN_FIXED ||
636 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
637 hci_conn_hold(conn->hcon);
638
639 list_add(&chan->list, &conn->chan_l);
640 }
641
642 void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
643 {
644 mutex_lock(&conn->chan_lock);
645 __l2cap_chan_add(conn, chan);
646 mutex_unlock(&conn->chan_lock);
647 }
648
649 void l2cap_chan_del(struct l2cap_chan *chan, int err)
650 {
651 struct l2cap_conn *conn = chan->conn;
652
653 __clear_chan_timer(chan);
654
655 BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err,
656 state_to_string(chan->state));
657
658 chan->ops->teardown(chan, err);
659
660 if (conn) {
661 /* Delete from channel list */
662 list_del(&chan->list);
663
664 l2cap_chan_put(chan);
665
666 chan->conn = NULL;
667
668 /* Reference was only held for non-fixed channels or
669 * fixed channels that explicitly requested it using the
670 * FLAG_HOLD_HCI_CONN flag.
671 */
672 if (chan->chan_type != L2CAP_CHAN_FIXED ||
673 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
674 hci_conn_drop(conn->hcon);
675 }
676
677 if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state))
678 return;
679
680 switch (chan->mode) {
681 case L2CAP_MODE_BASIC:
682 break;
683
684 case L2CAP_MODE_LE_FLOWCTL:
685 case L2CAP_MODE_EXT_FLOWCTL:
686 skb_queue_purge(&chan->tx_q);
687 break;
688
689 case L2CAP_MODE_ERTM:
690 __clear_retrans_timer(chan);
691 __clear_monitor_timer(chan);
692 __clear_ack_timer(chan);
693
694 skb_queue_purge(&chan->srej_q);
695
696 l2cap_seq_list_free(&chan->srej_list);
697 l2cap_seq_list_free(&chan->retrans_list);
698 fallthrough;
699
700 case L2CAP_MODE_STREAMING:
701 skb_queue_purge(&chan->tx_q);
702 break;
703 }
704 }
705 EXPORT_SYMBOL_GPL(l2cap_chan_del);
706
707 static void __l2cap_chan_list_id(struct l2cap_conn *conn, u16 id,
708 l2cap_chan_func_t func, void *data)
709 {
710 struct l2cap_chan *chan, *l;
711
712 list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
713 if (chan->ident == id)
714 func(chan, data);
715 }
716 }
717
718 static void __l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
719 void *data)
720 {
721 struct l2cap_chan *chan;
722
723 list_for_each_entry(chan, &conn->chan_l, list) {
724 func(chan, data);
725 }
726 }
727
728 void l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
729 void *data)
730 {
731 if (!conn)
732 return;
733
734 mutex_lock(&conn->chan_lock);
735 __l2cap_chan_list(conn, func, data);
736 mutex_unlock(&conn->chan_lock);
737 }
738
739 EXPORT_SYMBOL_GPL(l2cap_chan_list);
740
741 static void l2cap_conn_update_id_addr(struct work_struct *work)
742 {
743 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
744 id_addr_timer.work);
745 struct hci_conn *hcon = conn->hcon;
746 struct l2cap_chan *chan;
747
748 mutex_lock(&conn->chan_lock);
749
750 list_for_each_entry(chan, &conn->chan_l, list) {
751 l2cap_chan_lock(chan);
752 bacpy(&chan->dst, &hcon->dst);
753 chan->dst_type = bdaddr_dst_type(hcon);
754 l2cap_chan_unlock(chan);
755 }
756
757 mutex_unlock(&conn->chan_lock);
758 }
759
760 static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan)
761 {
762 struct l2cap_conn *conn = chan->conn;
763 struct l2cap_le_conn_rsp rsp;
764 u16 result;
765
766 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
767 result = L2CAP_CR_LE_AUTHORIZATION;
768 else
769 result = L2CAP_CR_LE_BAD_PSM;
770
771 l2cap_state_change(chan, BT_DISCONN);
772
773 rsp.dcid = cpu_to_le16(chan->scid);
774 rsp.mtu = cpu_to_le16(chan->imtu);
775 rsp.mps = cpu_to_le16(chan->mps);
776 rsp.credits = cpu_to_le16(chan->rx_credits);
777 rsp.result = cpu_to_le16(result);
778
779 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
780 &rsp);
781 }
782
783 static void l2cap_chan_ecred_connect_reject(struct l2cap_chan *chan)
784 {
785 l2cap_state_change(chan, BT_DISCONN);
786
787 __l2cap_ecred_conn_rsp_defer(chan);
788 }
789
790 static void l2cap_chan_connect_reject(struct l2cap_chan *chan)
791 {
792 struct l2cap_conn *conn = chan->conn;
793 struct l2cap_conn_rsp rsp;
794 u16 result;
795
796 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
797 result = L2CAP_CR_SEC_BLOCK;
798 else
799 result = L2CAP_CR_BAD_PSM;
800
801 l2cap_state_change(chan, BT_DISCONN);
802
803 rsp.scid = cpu_to_le16(chan->dcid);
804 rsp.dcid = cpu_to_le16(chan->scid);
805 rsp.result = cpu_to_le16(result);
806 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
807
808 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, sizeof(rsp), &rsp);
809 }
810
811 void l2cap_chan_close(struct l2cap_chan *chan, int reason)
812 {
813 struct l2cap_conn *conn = chan->conn;
814
815 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
816
817 switch (chan->state) {
818 case BT_LISTEN:
819 chan->ops->teardown(chan, 0);
820 break;
821
822 case BT_CONNECTED:
823 case BT_CONFIG:
824 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
825 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
826 l2cap_send_disconn_req(chan, reason);
827 } else
828 l2cap_chan_del(chan, reason);
829 break;
830
831 case BT_CONNECT2:
832 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
833 if (conn->hcon->type == ACL_LINK)
834 l2cap_chan_connect_reject(chan);
835 else if (conn->hcon->type == LE_LINK) {
836 switch (chan->mode) {
837 case L2CAP_MODE_LE_FLOWCTL:
838 l2cap_chan_le_connect_reject(chan);
839 break;
840 case L2CAP_MODE_EXT_FLOWCTL:
841 l2cap_chan_ecred_connect_reject(chan);
842 return;
843 }
844 }
845 }
846
847 l2cap_chan_del(chan, reason);
848 break;
849
850 case BT_CONNECT:
851 case BT_DISCONN:
852 l2cap_chan_del(chan, reason);
853 break;
854
855 default:
856 chan->ops->teardown(chan, 0);
857 break;
858 }
859 }
860 EXPORT_SYMBOL(l2cap_chan_close);
861
862 static inline u8 l2cap_get_auth_type(struct l2cap_chan *chan)
863 {
864 switch (chan->chan_type) {
865 case L2CAP_CHAN_RAW:
866 switch (chan->sec_level) {
867 case BT_SECURITY_HIGH:
868 case BT_SECURITY_FIPS:
869 return HCI_AT_DEDICATED_BONDING_MITM;
870 case BT_SECURITY_MEDIUM:
871 return HCI_AT_DEDICATED_BONDING;
872 default:
873 return HCI_AT_NO_BONDING;
874 }
875 break;
876 case L2CAP_CHAN_CONN_LESS:
877 if (chan->psm == cpu_to_le16(L2CAP_PSM_3DSP)) {
878 if (chan->sec_level == BT_SECURITY_LOW)
879 chan->sec_level = BT_SECURITY_SDP;
880 }
881 if (chan->sec_level == BT_SECURITY_HIGH ||
882 chan->sec_level == BT_SECURITY_FIPS)
883 return HCI_AT_NO_BONDING_MITM;
884 else
885 return HCI_AT_NO_BONDING;
886 break;
887 case L2CAP_CHAN_CONN_ORIENTED:
888 if (chan->psm == cpu_to_le16(L2CAP_PSM_SDP)) {
889 if (chan->sec_level == BT_SECURITY_LOW)
890 chan->sec_level = BT_SECURITY_SDP;
891
892 if (chan->sec_level == BT_SECURITY_HIGH ||
893 chan->sec_level == BT_SECURITY_FIPS)
894 return HCI_AT_NO_BONDING_MITM;
895 else
896 return HCI_AT_NO_BONDING;
897 }
898 fallthrough;
899
900 default:
901 switch (chan->sec_level) {
902 case BT_SECURITY_HIGH:
903 case BT_SECURITY_FIPS:
904 return HCI_AT_GENERAL_BONDING_MITM;
905 case BT_SECURITY_MEDIUM:
906 return HCI_AT_GENERAL_BONDING;
907 default:
908 return HCI_AT_NO_BONDING;
909 }
910 break;
911 }
912 }
913
914 /* Service level security */
915 int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator)
916 {
917 struct l2cap_conn *conn = chan->conn;
918 __u8 auth_type;
919
920 if (conn->hcon->type == LE_LINK)
921 return smp_conn_security(conn->hcon, chan->sec_level);
922
923 auth_type = l2cap_get_auth_type(chan);
924
925 return hci_conn_security(conn->hcon, chan->sec_level, auth_type,
926 initiator);
927 }
928
929 static u8 l2cap_get_ident(struct l2cap_conn *conn)
930 {
931 u8 id;
932
933 /* Get next available identificator.
934 * 1 - 128 are used by kernel.
935 * 129 - 199 are reserved.
936 * 200 - 254 are used by utilities like l2ping, etc.
937 */
938
939 mutex_lock(&conn->ident_lock);
940
941 if (++conn->tx_ident > 128)
942 conn->tx_ident = 1;
943
944 id = conn->tx_ident;
945
946 mutex_unlock(&conn->ident_lock);
947
948 return id;
949 }
950
951 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
952 void *data)
953 {
954 struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data);
955 u8 flags;
956
957 BT_DBG("code 0x%2.2x", code);
958
959 if (!skb)
960 return;
961
962 /* Use NO_FLUSH if supported or we have an LE link (which does
963 * not support auto-flushing packets) */
964 if (lmp_no_flush_capable(conn->hcon->hdev) ||
965 conn->hcon->type == LE_LINK)
966 flags = ACL_START_NO_FLUSH;
967 else
968 flags = ACL_START;
969
970 bt_cb(skb)->force_active = BT_POWER_FORCE_ACTIVE_ON;
971 skb->priority = HCI_PRIO_MAX;
972
973 hci_send_acl(conn->hchan, skb, flags);
974 }
975
976 static void l2cap_do_send(struct l2cap_chan *chan, struct sk_buff *skb)
977 {
978 struct hci_conn *hcon = chan->conn->hcon;
979 u16 flags;
980
981 BT_DBG("chan %p, skb %p len %d priority %u", chan, skb, skb->len,
982 skb->priority);
983
984 /* Use NO_FLUSH for LE links (where this is the only option) or
985 * if the BR/EDR link supports it and flushing has not been
986 * explicitly requested (through FLAG_FLUSHABLE).
987 */
988 if (hcon->type == LE_LINK ||
989 (!test_bit(FLAG_FLUSHABLE, &chan->flags) &&
990 lmp_no_flush_capable(hcon->hdev)))
991 flags = ACL_START_NO_FLUSH;
992 else
993 flags = ACL_START;
994
995 bt_cb(skb)->force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags);
996 hci_send_acl(chan->conn->hchan, skb, flags);
997 }
998
999 static void __unpack_enhanced_control(u16 enh, struct l2cap_ctrl *control)
1000 {
1001 control->reqseq = (enh & L2CAP_CTRL_REQSEQ) >> L2CAP_CTRL_REQSEQ_SHIFT;
1002 control->final = (enh & L2CAP_CTRL_FINAL) >> L2CAP_CTRL_FINAL_SHIFT;
1003
1004 if (enh & L2CAP_CTRL_FRAME_TYPE) {
1005 /* S-Frame */
1006 control->sframe = 1;
1007 control->poll = (enh & L2CAP_CTRL_POLL) >> L2CAP_CTRL_POLL_SHIFT;
1008 control->super = (enh & L2CAP_CTRL_SUPERVISE) >> L2CAP_CTRL_SUPER_SHIFT;
1009
1010 control->sar = 0;
1011 control->txseq = 0;
1012 } else {
1013 /* I-Frame */
1014 control->sframe = 0;
1015 control->sar = (enh & L2CAP_CTRL_SAR) >> L2CAP_CTRL_SAR_SHIFT;
1016 control->txseq = (enh & L2CAP_CTRL_TXSEQ) >> L2CAP_CTRL_TXSEQ_SHIFT;
1017
1018 control->poll = 0;
1019 control->super = 0;
1020 }
1021 }
1022
1023 static void __unpack_extended_control(u32 ext, struct l2cap_ctrl *control)
1024 {
1025 control->reqseq = (ext & L2CAP_EXT_CTRL_REQSEQ) >> L2CAP_EXT_CTRL_REQSEQ_SHIFT;
1026 control->final = (ext & L2CAP_EXT_CTRL_FINAL) >> L2CAP_EXT_CTRL_FINAL_SHIFT;
1027
1028 if (ext & L2CAP_EXT_CTRL_FRAME_TYPE) {
1029 /* S-Frame */
1030 control->sframe = 1;
1031 control->poll = (ext & L2CAP_EXT_CTRL_POLL) >> L2CAP_EXT_CTRL_POLL_SHIFT;
1032 control->super = (ext & L2CAP_EXT_CTRL_SUPERVISE) >> L2CAP_EXT_CTRL_SUPER_SHIFT;
1033
1034 control->sar = 0;
1035 control->txseq = 0;
1036 } else {
1037 /* I-Frame */
1038 control->sframe = 0;
1039 control->sar = (ext & L2CAP_EXT_CTRL_SAR) >> L2CAP_EXT_CTRL_SAR_SHIFT;
1040 control->txseq = (ext & L2CAP_EXT_CTRL_TXSEQ) >> L2CAP_EXT_CTRL_TXSEQ_SHIFT;
1041
1042 control->poll = 0;
1043 control->super = 0;
1044 }
1045 }
1046
1047 static inline void __unpack_control(struct l2cap_chan *chan,
1048 struct sk_buff *skb)
1049 {
1050 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
1051 __unpack_extended_control(get_unaligned_le32(skb->data),
1052 &bt_cb(skb)->l2cap);
1053 skb_pull(skb, L2CAP_EXT_CTRL_SIZE);
1054 } else {
1055 __unpack_enhanced_control(get_unaligned_le16(skb->data),
1056 &bt_cb(skb)->l2cap);
1057 skb_pull(skb, L2CAP_ENH_CTRL_SIZE);
1058 }
1059 }
1060
1061 static u32 __pack_extended_control(struct l2cap_ctrl *control)
1062 {
1063 u32 packed;
1064
1065 packed = control->reqseq << L2CAP_EXT_CTRL_REQSEQ_SHIFT;
1066 packed |= control->final << L2CAP_EXT_CTRL_FINAL_SHIFT;
1067
1068 if (control->sframe) {
1069 packed |= control->poll << L2CAP_EXT_CTRL_POLL_SHIFT;
1070 packed |= control->super << L2CAP_EXT_CTRL_SUPER_SHIFT;
1071 packed |= L2CAP_EXT_CTRL_FRAME_TYPE;
1072 } else {
1073 packed |= control->sar << L2CAP_EXT_CTRL_SAR_SHIFT;
1074 packed |= control->txseq << L2CAP_EXT_CTRL_TXSEQ_SHIFT;
1075 }
1076
1077 return packed;
1078 }
1079
1080 static u16 __pack_enhanced_control(struct l2cap_ctrl *control)
1081 {
1082 u16 packed;
1083
1084 packed = control->reqseq << L2CAP_CTRL_REQSEQ_SHIFT;
1085 packed |= control->final << L2CAP_CTRL_FINAL_SHIFT;
1086
1087 if (control->sframe) {
1088 packed |= control->poll << L2CAP_CTRL_POLL_SHIFT;
1089 packed |= control->super << L2CAP_CTRL_SUPER_SHIFT;
1090 packed |= L2CAP_CTRL_FRAME_TYPE;
1091 } else {
1092 packed |= control->sar << L2CAP_CTRL_SAR_SHIFT;
1093 packed |= control->txseq << L2CAP_CTRL_TXSEQ_SHIFT;
1094 }
1095
1096 return packed;
1097 }
1098
1099 static inline void __pack_control(struct l2cap_chan *chan,
1100 struct l2cap_ctrl *control,
1101 struct sk_buff *skb)
1102 {
1103 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
1104 put_unaligned_le32(__pack_extended_control(control),
1105 skb->data + L2CAP_HDR_SIZE);
1106 } else {
1107 put_unaligned_le16(__pack_enhanced_control(control),
1108 skb->data + L2CAP_HDR_SIZE);
1109 }
1110 }
1111
1112 static inline unsigned int __ertm_hdr_size(struct l2cap_chan *chan)
1113 {
1114 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1115 return L2CAP_EXT_HDR_SIZE;
1116 else
1117 return L2CAP_ENH_HDR_SIZE;
1118 }
1119
1120 static struct sk_buff *l2cap_create_sframe_pdu(struct l2cap_chan *chan,
1121 u32 control)
1122 {
1123 struct sk_buff *skb;
1124 struct l2cap_hdr *lh;
1125 int hlen = __ertm_hdr_size(chan);
1126
1127 if (chan->fcs == L2CAP_FCS_CRC16)
1128 hlen += L2CAP_FCS_SIZE;
1129
1130 skb = bt_skb_alloc(hlen, GFP_KERNEL);
1131
1132 if (!skb)
1133 return ERR_PTR(-ENOMEM);
1134
1135 lh = skb_put(skb, L2CAP_HDR_SIZE);
1136 lh->len = cpu_to_le16(hlen - L2CAP_HDR_SIZE);
1137 lh->cid = cpu_to_le16(chan->dcid);
1138
1139 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1140 put_unaligned_le32(control, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
1141 else
1142 put_unaligned_le16(control, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
1143
1144 if (chan->fcs == L2CAP_FCS_CRC16) {
1145 u16 fcs = crc16(0, (u8 *)skb->data, skb->len);
1146 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1147 }
1148
1149 skb->priority = HCI_PRIO_MAX;
1150 return skb;
1151 }
1152
1153 static void l2cap_send_sframe(struct l2cap_chan *chan,
1154 struct l2cap_ctrl *control)
1155 {
1156 struct sk_buff *skb;
1157 u32 control_field;
1158
1159 BT_DBG("chan %p, control %p", chan, control);
1160
1161 if (!control->sframe)
1162 return;
1163
1164 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state) &&
1165 !control->poll)
1166 control->final = 1;
1167
1168 if (control->super == L2CAP_SUPER_RR)
1169 clear_bit(CONN_RNR_SENT, &chan->conn_state);
1170 else if (control->super == L2CAP_SUPER_RNR)
1171 set_bit(CONN_RNR_SENT, &chan->conn_state);
1172
1173 if (control->super != L2CAP_SUPER_SREJ) {
1174 chan->last_acked_seq = control->reqseq;
1175 __clear_ack_timer(chan);
1176 }
1177
1178 BT_DBG("reqseq %d, final %d, poll %d, super %d", control->reqseq,
1179 control->final, control->poll, control->super);
1180
1181 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1182 control_field = __pack_extended_control(control);
1183 else
1184 control_field = __pack_enhanced_control(control);
1185
1186 skb = l2cap_create_sframe_pdu(chan, control_field);
1187 if (!IS_ERR(skb))
1188 l2cap_do_send(chan, skb);
1189 }
1190
1191 static void l2cap_send_rr_or_rnr(struct l2cap_chan *chan, bool poll)
1192 {
1193 struct l2cap_ctrl control;
1194
1195 BT_DBG("chan %p, poll %d", chan, poll);
1196
1197 memset(&control, 0, sizeof(control));
1198 control.sframe = 1;
1199 control.poll = poll;
1200
1201 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
1202 control.super = L2CAP_SUPER_RNR;
1203 else
1204 control.super = L2CAP_SUPER_RR;
1205
1206 control.reqseq = chan->buffer_seq;
1207 l2cap_send_sframe(chan, &control);
1208 }
1209
1210 static inline int __l2cap_no_conn_pending(struct l2cap_chan *chan)
1211 {
1212 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
1213 return true;
1214
1215 return !test_bit(CONF_CONNECT_PEND, &chan->conf_state);
1216 }
1217
1218 void l2cap_send_conn_req(struct l2cap_chan *chan)
1219 {
1220 struct l2cap_conn *conn = chan->conn;
1221 struct l2cap_conn_req req;
1222
1223 req.scid = cpu_to_le16(chan->scid);
1224 req.psm = chan->psm;
1225
1226 chan->ident = l2cap_get_ident(conn);
1227
1228 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
1229
1230 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_REQ, sizeof(req), &req);
1231 }
1232
1233 static void l2cap_chan_ready(struct l2cap_chan *chan)
1234 {
1235 /* The channel may have already been flagged as connected in
1236 * case of receiving data before the L2CAP info req/rsp
1237 * procedure is complete.
1238 */
1239 if (chan->state == BT_CONNECTED)
1240 return;
1241
1242 /* This clears all conf flags, including CONF_NOT_COMPLETE */
1243 chan->conf_state = 0;
1244 __clear_chan_timer(chan);
1245
1246 switch (chan->mode) {
1247 case L2CAP_MODE_LE_FLOWCTL:
1248 case L2CAP_MODE_EXT_FLOWCTL:
1249 if (!chan->tx_credits)
1250 chan->ops->suspend(chan);
1251 break;
1252 }
1253
1254 chan->state = BT_CONNECTED;
1255
1256 chan->ops->ready(chan);
1257 }
1258
1259 static void l2cap_le_connect(struct l2cap_chan *chan)
1260 {
1261 struct l2cap_conn *conn = chan->conn;
1262 struct l2cap_le_conn_req req;
1263
1264 if (test_and_set_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags))
1265 return;
1266
1267 if (!chan->imtu)
1268 chan->imtu = chan->conn->mtu;
1269
1270 l2cap_le_flowctl_init(chan, 0);
1271
1272 memset(&req, 0, sizeof(req));
1273 req.psm = chan->psm;
1274 req.scid = cpu_to_le16(chan->scid);
1275 req.mtu = cpu_to_le16(chan->imtu);
1276 req.mps = cpu_to_le16(chan->mps);
1277 req.credits = cpu_to_le16(chan->rx_credits);
1278
1279 chan->ident = l2cap_get_ident(conn);
1280
1281 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_REQ,
1282 sizeof(req), &req);
1283 }
1284
1285 struct l2cap_ecred_conn_data {
1286 struct {
1287 struct l2cap_ecred_conn_req_hdr req;
1288 __le16 scid[5];
1289 } __packed pdu;
1290 struct l2cap_chan *chan;
1291 struct pid *pid;
1292 int count;
1293 };
1294
1295 static void l2cap_ecred_defer_connect(struct l2cap_chan *chan, void *data)
1296 {
1297 struct l2cap_ecred_conn_data *conn = data;
1298 struct pid *pid;
1299
1300 if (chan == conn->chan)
1301 return;
1302
1303 if (!test_and_clear_bit(FLAG_DEFER_SETUP, &chan->flags))
1304 return;
1305
1306 pid = chan->ops->get_peer_pid(chan);
1307
1308 /* Only add deferred channels with the same PID/PSM */
1309 if (conn->pid != pid || chan->psm != conn->chan->psm || chan->ident ||
1310 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
1311 return;
1312
1313 if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
1314 return;
1315
1316 l2cap_ecred_init(chan, 0);
1317
1318 /* Set the same ident so we can match on the rsp */
1319 chan->ident = conn->chan->ident;
1320
1321 /* Include all channels deferred */
1322 conn->pdu.scid[conn->count] = cpu_to_le16(chan->scid);
1323
1324 conn->count++;
1325 }
1326
1327 static void l2cap_ecred_connect(struct l2cap_chan *chan)
1328 {
1329 struct l2cap_conn *conn = chan->conn;
1330 struct l2cap_ecred_conn_data data;
1331
1332 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
1333 return;
1334
1335 if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
1336 return;
1337
1338 l2cap_ecred_init(chan, 0);
1339
1340 memset(&data, 0, sizeof(data));
1341 data.pdu.req.psm = chan->psm;
1342 data.pdu.req.mtu = cpu_to_le16(chan->imtu);
1343 data.pdu.req.mps = cpu_to_le16(chan->mps);
1344 data.pdu.req.credits = cpu_to_le16(chan->rx_credits);
1345 data.pdu.scid[0] = cpu_to_le16(chan->scid);
1346
1347 chan->ident = l2cap_get_ident(conn);
1348
1349 data.count = 1;
1350 data.chan = chan;
1351 data.pid = chan->ops->get_peer_pid(chan);
1352
1353 __l2cap_chan_list(conn, l2cap_ecred_defer_connect, &data);
1354
1355 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_CONN_REQ,
1356 sizeof(data.pdu.req) + data.count * sizeof(__le16),
1357 &data.pdu);
1358 }
1359
1360 static void l2cap_le_start(struct l2cap_chan *chan)
1361 {
1362 struct l2cap_conn *conn = chan->conn;
1363
1364 if (!smp_conn_security(conn->hcon, chan->sec_level))
1365 return;
1366
1367 if (!chan->psm) {
1368 l2cap_chan_ready(chan);
1369 return;
1370 }
1371
1372 if (chan->state == BT_CONNECT) {
1373 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL)
1374 l2cap_ecred_connect(chan);
1375 else
1376 l2cap_le_connect(chan);
1377 }
1378 }
1379
1380 static void l2cap_start_connection(struct l2cap_chan *chan)
1381 {
1382 if (chan->conn->hcon->type == LE_LINK) {
1383 l2cap_le_start(chan);
1384 } else {
1385 l2cap_send_conn_req(chan);
1386 }
1387 }
1388
1389 static void l2cap_request_info(struct l2cap_conn *conn)
1390 {
1391 struct l2cap_info_req req;
1392
1393 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1394 return;
1395
1396 req.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
1397
1398 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
1399 conn->info_ident = l2cap_get_ident(conn);
1400
1401 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
1402
1403 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
1404 sizeof(req), &req);
1405 }
1406
1407 static bool l2cap_check_enc_key_size(struct hci_conn *hcon)
1408 {
1409 /* The minimum encryption key size needs to be enforced by the
1410 * host stack before establishing any L2CAP connections. The
1411 * specification in theory allows a minimum of 1, but to align
1412 * BR/EDR and LE transports, a minimum of 7 is chosen.
1413 *
1414 * This check might also be called for unencrypted connections
1415 * that have no key size requirements. Ensure that the link is
1416 * actually encrypted before enforcing a key size.
1417 */
1418 int min_key_size = hcon->hdev->min_enc_key_size;
1419
1420 /* On FIPS security level, key size must be 16 bytes */
1421 if (hcon->sec_level == BT_SECURITY_FIPS)
1422 min_key_size = 16;
1423
1424 return (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags) ||
1425 hcon->enc_key_size >= min_key_size);
1426 }
1427
1428 static void l2cap_do_start(struct l2cap_chan *chan)
1429 {
1430 struct l2cap_conn *conn = chan->conn;
1431
1432 if (conn->hcon->type == LE_LINK) {
1433 l2cap_le_start(chan);
1434 return;
1435 }
1436
1437 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)) {
1438 l2cap_request_info(conn);
1439 return;
1440 }
1441
1442 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE))
1443 return;
1444
1445 if (!l2cap_chan_check_security(chan, true) ||
1446 !__l2cap_no_conn_pending(chan))
1447 return;
1448
1449 if (l2cap_check_enc_key_size(conn->hcon))
1450 l2cap_start_connection(chan);
1451 else
1452 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
1453 }
1454
1455 static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
1456 {
1457 u32 local_feat_mask = l2cap_feat_mask;
1458 if (!disable_ertm)
1459 local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
1460
1461 switch (mode) {
1462 case L2CAP_MODE_ERTM:
1463 return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
1464 case L2CAP_MODE_STREAMING:
1465 return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
1466 default:
1467 return 0x00;
1468 }
1469 }
1470
1471 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err)
1472 {
1473 struct l2cap_conn *conn = chan->conn;
1474 struct l2cap_disconn_req req;
1475
1476 if (!conn)
1477 return;
1478
1479 if (chan->mode == L2CAP_MODE_ERTM && chan->state == BT_CONNECTED) {
1480 __clear_retrans_timer(chan);
1481 __clear_monitor_timer(chan);
1482 __clear_ack_timer(chan);
1483 }
1484
1485 req.dcid = cpu_to_le16(chan->dcid);
1486 req.scid = cpu_to_le16(chan->scid);
1487 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_DISCONN_REQ,
1488 sizeof(req), &req);
1489
1490 l2cap_state_change_and_error(chan, BT_DISCONN, err);
1491 }
1492
1493 /* ---- L2CAP connections ---- */
1494 static void l2cap_conn_start(struct l2cap_conn *conn)
1495 {
1496 struct l2cap_chan *chan, *tmp;
1497
1498 BT_DBG("conn %p", conn);
1499
1500 mutex_lock(&conn->chan_lock);
1501
1502 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
1503 l2cap_chan_lock(chan);
1504
1505 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1506 l2cap_chan_ready(chan);
1507 l2cap_chan_unlock(chan);
1508 continue;
1509 }
1510
1511 if (chan->state == BT_CONNECT) {
1512 if (!l2cap_chan_check_security(chan, true) ||
1513 !__l2cap_no_conn_pending(chan)) {
1514 l2cap_chan_unlock(chan);
1515 continue;
1516 }
1517
1518 if (!l2cap_mode_supported(chan->mode, conn->feat_mask)
1519 && test_bit(CONF_STATE2_DEVICE,
1520 &chan->conf_state)) {
1521 l2cap_chan_close(chan, ECONNRESET);
1522 l2cap_chan_unlock(chan);
1523 continue;
1524 }
1525
1526 if (l2cap_check_enc_key_size(conn->hcon))
1527 l2cap_start_connection(chan);
1528 else
1529 l2cap_chan_close(chan, ECONNREFUSED);
1530
1531 } else if (chan->state == BT_CONNECT2) {
1532 struct l2cap_conn_rsp rsp;
1533 char buf[128];
1534 rsp.scid = cpu_to_le16(chan->dcid);
1535 rsp.dcid = cpu_to_le16(chan->scid);
1536
1537 if (l2cap_chan_check_security(chan, false)) {
1538 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
1539 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1540 rsp.status = cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
1541 chan->ops->defer(chan);
1542
1543 } else {
1544 l2cap_state_change(chan, BT_CONFIG);
1545 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
1546 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
1547 }
1548 } else {
1549 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1550 rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
1551 }
1552
1553 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
1554 sizeof(rsp), &rsp);
1555
1556 if (test_bit(CONF_REQ_SENT, &chan->conf_state) ||
1557 rsp.result != L2CAP_CR_SUCCESS) {
1558 l2cap_chan_unlock(chan);
1559 continue;
1560 }
1561
1562 set_bit(CONF_REQ_SENT, &chan->conf_state);
1563 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
1564 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
1565 chan->num_conf_req++;
1566 }
1567
1568 l2cap_chan_unlock(chan);
1569 }
1570
1571 mutex_unlock(&conn->chan_lock);
1572 }
1573
1574 static void l2cap_le_conn_ready(struct l2cap_conn *conn)
1575 {
1576 struct hci_conn *hcon = conn->hcon;
1577 struct hci_dev *hdev = hcon->hdev;
1578
1579 BT_DBG("%s conn %p", hdev->name, conn);
1580
1581 /* For outgoing pairing which doesn't necessarily have an
1582 * associated socket (e.g. mgmt_pair_device).
1583 */
1584 if (hcon->out)
1585 smp_conn_security(hcon, hcon->pending_sec_level);
1586
1587 /* For LE peripheral connections, make sure the connection interval
1588 * is in the range of the minimum and maximum interval that has
1589 * been configured for this connection. If not, then trigger
1590 * the connection update procedure.
1591 */
1592 if (hcon->role == HCI_ROLE_SLAVE &&
1593 (hcon->le_conn_interval < hcon->le_conn_min_interval ||
1594 hcon->le_conn_interval > hcon->le_conn_max_interval)) {
1595 struct l2cap_conn_param_update_req req;
1596
1597 req.min = cpu_to_le16(hcon->le_conn_min_interval);
1598 req.max = cpu_to_le16(hcon->le_conn_max_interval);
1599 req.latency = cpu_to_le16(hcon->le_conn_latency);
1600 req.to_multiplier = cpu_to_le16(hcon->le_supv_timeout);
1601
1602 l2cap_send_cmd(conn, l2cap_get_ident(conn),
1603 L2CAP_CONN_PARAM_UPDATE_REQ, sizeof(req), &req);
1604 }
1605 }
1606
1607 static void l2cap_conn_ready(struct l2cap_conn *conn)
1608 {
1609 struct l2cap_chan *chan;
1610 struct hci_conn *hcon = conn->hcon;
1611
1612 BT_DBG("conn %p", conn);
1613
1614 if (hcon->type == ACL_LINK)
1615 l2cap_request_info(conn);
1616
1617 mutex_lock(&conn->chan_lock);
1618
1619 list_for_each_entry(chan, &conn->chan_l, list) {
1620
1621 l2cap_chan_lock(chan);
1622
1623 if (hcon->type == LE_LINK) {
1624 l2cap_le_start(chan);
1625 } else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1626 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
1627 l2cap_chan_ready(chan);
1628 } else if (chan->state == BT_CONNECT) {
1629 l2cap_do_start(chan);
1630 }
1631
1632 l2cap_chan_unlock(chan);
1633 }
1634
1635 mutex_unlock(&conn->chan_lock);
1636
1637 if (hcon->type == LE_LINK)
1638 l2cap_le_conn_ready(conn);
1639
1640 queue_work(hcon->hdev->workqueue, &conn->pending_rx_work);
1641 }
1642
1643 /* Notify sockets that we cannot guaranty reliability anymore */
1644 static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
1645 {
1646 struct l2cap_chan *chan;
1647
1648 BT_DBG("conn %p", conn);
1649
1650 mutex_lock(&conn->chan_lock);
1651
1652 list_for_each_entry(chan, &conn->chan_l, list) {
1653 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
1654 l2cap_chan_set_err(chan, err);
1655 }
1656
1657 mutex_unlock(&conn->chan_lock);
1658 }
1659
1660 static void l2cap_info_timeout(struct work_struct *work)
1661 {
1662 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
1663 info_timer.work);
1664
1665 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
1666 conn->info_ident = 0;
1667
1668 l2cap_conn_start(conn);
1669 }
1670
1671 /*
1672 * l2cap_user
1673 * External modules can register l2cap_user objects on l2cap_conn. The ->probe
1674 * callback is called during registration. The ->remove callback is called
1675 * during unregistration.
1676 * An l2cap_user object can either be explicitly unregistered or when the
1677 * underlying l2cap_conn object is deleted. This guarantees that l2cap->hcon,
1678 * l2cap->hchan, .. are valid as long as the remove callback hasn't been called.
1679 * External modules must own a reference to the l2cap_conn object if they intend
1680 * to call l2cap_unregister_user(). The l2cap_conn object might get destroyed at
1681 * any time if they don't.
1682 */
1683
1684 int l2cap_register_user(struct l2cap_conn *conn, struct l2cap_user *user)
1685 {
1686 struct hci_dev *hdev = conn->hcon->hdev;
1687 int ret;
1688
1689 /* We need to check whether l2cap_conn is registered. If it is not, we
1690 * must not register the l2cap_user. l2cap_conn_del() is unregisters
1691 * l2cap_conn objects, but doesn't provide its own locking. Instead, it
1692 * relies on the parent hci_conn object to be locked. This itself relies
1693 * on the hci_dev object to be locked. So we must lock the hci device
1694 * here, too. */
1695
1696 hci_dev_lock(hdev);
1697
1698 if (!list_empty(&user->list)) {
1699 ret = -EINVAL;
1700 goto out_unlock;
1701 }
1702
1703 /* conn->hchan is NULL after l2cap_conn_del() was called */
1704 if (!conn->hchan) {
1705 ret = -ENODEV;
1706 goto out_unlock;
1707 }
1708
1709 ret = user->probe(conn, user);
1710 if (ret)
1711 goto out_unlock;
1712
1713 list_add(&user->list, &conn->users);
1714 ret = 0;
1715
1716 out_unlock:
1717 hci_dev_unlock(hdev);
1718 return ret;
1719 }
1720 EXPORT_SYMBOL(l2cap_register_user);
1721
1722 void l2cap_unregister_user(struct l2cap_conn *conn, struct l2cap_user *user)
1723 {
1724 struct hci_dev *hdev = conn->hcon->hdev;
1725
1726 hci_dev_lock(hdev);
1727
1728 if (list_empty(&user->list))
1729 goto out_unlock;
1730
1731 list_del_init(&user->list);
1732 user->remove(conn, user);
1733
1734 out_unlock:
1735 hci_dev_unlock(hdev);
1736 }
1737 EXPORT_SYMBOL(l2cap_unregister_user);
1738
1739 static void l2cap_unregister_all_users(struct l2cap_conn *conn)
1740 {
1741 struct l2cap_user *user;
1742
1743 while (!list_empty(&conn->users)) {
1744 user = list_first_entry(&conn->users, struct l2cap_user, list);
1745 list_del_init(&user->list);
1746 user->remove(conn, user);
1747 }
1748 }
1749
1750 static void l2cap_conn_del(struct hci_conn *hcon, int err)
1751 {
1752 struct l2cap_conn *conn = hcon->l2cap_data;
1753 struct l2cap_chan *chan, *l;
1754
1755 if (!conn)
1756 return;
1757
1758 BT_DBG("hcon %p conn %p, err %d", hcon, conn, err);
1759
1760 kfree_skb(conn->rx_skb);
1761
1762 skb_queue_purge(&conn->pending_rx);
1763
1764 /* We can not call flush_work(&conn->pending_rx_work) here since we
1765 * might block if we are running on a worker from the same workqueue
1766 * pending_rx_work is waiting on.
1767 */
1768 if (work_pending(&conn->pending_rx_work))
1769 cancel_work_sync(&conn->pending_rx_work);
1770
1771 cancel_delayed_work_sync(&conn->id_addr_timer);
1772
1773 l2cap_unregister_all_users(conn);
1774
1775 /* Force the connection to be immediately dropped */
1776 hcon->disc_timeout = 0;
1777
1778 mutex_lock(&conn->chan_lock);
1779
1780 /* Kill channels */
1781 list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
1782 l2cap_chan_hold(chan);
1783 l2cap_chan_lock(chan);
1784
1785 l2cap_chan_del(chan, err);
1786
1787 chan->ops->close(chan);
1788
1789 l2cap_chan_unlock(chan);
1790 l2cap_chan_put(chan);
1791 }
1792
1793 mutex_unlock(&conn->chan_lock);
1794
1795 hci_chan_del(conn->hchan);
1796
1797 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1798 cancel_delayed_work_sync(&conn->info_timer);
1799
1800 hcon->l2cap_data = NULL;
1801 conn->hchan = NULL;
1802 l2cap_conn_put(conn);
1803 }
1804
1805 static void l2cap_conn_free(struct kref *ref)
1806 {
1807 struct l2cap_conn *conn = container_of(ref, struct l2cap_conn, ref);
1808
1809 hci_conn_put(conn->hcon);
1810 kfree(conn);
1811 }
1812
1813 struct l2cap_conn *l2cap_conn_get(struct l2cap_conn *conn)
1814 {
1815 kref_get(&conn->ref);
1816 return conn;
1817 }
1818 EXPORT_SYMBOL(l2cap_conn_get);
1819
1820 void l2cap_conn_put(struct l2cap_conn *conn)
1821 {
1822 kref_put(&conn->ref, l2cap_conn_free);
1823 }
1824 EXPORT_SYMBOL(l2cap_conn_put);
1825
1826 /* ---- Socket interface ---- */
1827
1828 /* Find socket with psm and source / destination bdaddr.
1829 * Returns closest match.
1830 */
1831 static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
1832 bdaddr_t *src,
1833 bdaddr_t *dst,
1834 u8 link_type)
1835 {
1836 struct l2cap_chan *c, *tmp, *c1 = NULL;
1837
1838 read_lock(&chan_list_lock);
1839
1840 list_for_each_entry_safe(c, tmp, &chan_list, global_l) {
1841 if (state && c->state != state)
1842 continue;
1843
1844 if (link_type == ACL_LINK && c->src_type != BDADDR_BREDR)
1845 continue;
1846
1847 if (link_type == LE_LINK && c->src_type == BDADDR_BREDR)
1848 continue;
1849
1850 if (c->chan_type != L2CAP_CHAN_FIXED && c->psm == psm) {
1851 int src_match, dst_match;
1852 int src_any, dst_any;
1853
1854 /* Exact match. */
1855 src_match = !bacmp(&c->src, src);
1856 dst_match = !bacmp(&c->dst, dst);
1857 if (src_match && dst_match) {
1858 if (!l2cap_chan_hold_unless_zero(c))
1859 continue;
1860
1861 read_unlock(&chan_list_lock);
1862 return c;
1863 }
1864
1865 /* Closest match */
1866 src_any = !bacmp(&c->src, BDADDR_ANY);
1867 dst_any = !bacmp(&c->dst, BDADDR_ANY);
1868 if ((src_match && dst_any) || (src_any && dst_match) ||
1869 (src_any && dst_any))
1870 c1 = c;
1871 }
1872 }
1873
1874 if (c1)
1875 c1 = l2cap_chan_hold_unless_zero(c1);
1876
1877 read_unlock(&chan_list_lock);
1878
1879 return c1;
1880 }
1881
1882 static void l2cap_monitor_timeout(struct work_struct *work)
1883 {
1884 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
1885 monitor_timer.work);
1886
1887 BT_DBG("chan %p", chan);
1888
1889 l2cap_chan_lock(chan);
1890
1891 if (!chan->conn) {
1892 l2cap_chan_unlock(chan);
1893 l2cap_chan_put(chan);
1894 return;
1895 }
1896
1897 l2cap_tx(chan, NULL, NULL, L2CAP_EV_MONITOR_TO);
1898
1899 l2cap_chan_unlock(chan);
1900 l2cap_chan_put(chan);
1901 }
1902
1903 static void l2cap_retrans_timeout(struct work_struct *work)
1904 {
1905 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
1906 retrans_timer.work);
1907
1908 BT_DBG("chan %p", chan);
1909
1910 l2cap_chan_lock(chan);
1911
1912 if (!chan->conn) {
1913 l2cap_chan_unlock(chan);
1914 l2cap_chan_put(chan);
1915 return;
1916 }
1917
1918 l2cap_tx(chan, NULL, NULL, L2CAP_EV_RETRANS_TO);
1919 l2cap_chan_unlock(chan);
1920 l2cap_chan_put(chan);
1921 }
1922
1923 static void l2cap_streaming_send(struct l2cap_chan *chan,
1924 struct sk_buff_head *skbs)
1925 {
1926 struct sk_buff *skb;
1927 struct l2cap_ctrl *control;
1928
1929 BT_DBG("chan %p, skbs %p", chan, skbs);
1930
1931 skb_queue_splice_tail_init(skbs, &chan->tx_q);
1932
1933 while (!skb_queue_empty(&chan->tx_q)) {
1934
1935 skb = skb_dequeue(&chan->tx_q);
1936
1937 bt_cb(skb)->l2cap.retries = 1;
1938 control = &bt_cb(skb)->l2cap;
1939
1940 control->reqseq = 0;
1941 control->txseq = chan->next_tx_seq;
1942
1943 __pack_control(chan, control, skb);
1944
1945 if (chan->fcs == L2CAP_FCS_CRC16) {
1946 u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
1947 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1948 }
1949
1950 l2cap_do_send(chan, skb);
1951
1952 BT_DBG("Sent txseq %u", control->txseq);
1953
1954 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
1955 chan->frames_sent++;
1956 }
1957 }
1958
1959 static int l2cap_ertm_send(struct l2cap_chan *chan)
1960 {
1961 struct sk_buff *skb, *tx_skb;
1962 struct l2cap_ctrl *control;
1963 int sent = 0;
1964
1965 BT_DBG("chan %p", chan);
1966
1967 if (chan->state != BT_CONNECTED)
1968 return -ENOTCONN;
1969
1970 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
1971 return 0;
1972
1973 while (chan->tx_send_head &&
1974 chan->unacked_frames < chan->remote_tx_win &&
1975 chan->tx_state == L2CAP_TX_STATE_XMIT) {
1976
1977 skb = chan->tx_send_head;
1978
1979 bt_cb(skb)->l2cap.retries = 1;
1980 control = &bt_cb(skb)->l2cap;
1981
1982 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
1983 control->final = 1;
1984
1985 control->reqseq = chan->buffer_seq;
1986 chan->last_acked_seq = chan->buffer_seq;
1987 control->txseq = chan->next_tx_seq;
1988
1989 __pack_control(chan, control, skb);
1990
1991 if (chan->fcs == L2CAP_FCS_CRC16) {
1992 u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
1993 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1994 }
1995
1996 /* Clone after data has been modified. Data is assumed to be
1997 read-only (for locking purposes) on cloned sk_buffs.
1998 */
1999 tx_skb = skb_clone(skb, GFP_KERNEL);
2000
2001 if (!tx_skb)
2002 break;
2003
2004 __set_retrans_timer(chan);
2005
2006 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
2007 chan->unacked_frames++;
2008 chan->frames_sent++;
2009 sent++;
2010
2011 if (skb_queue_is_last(&chan->tx_q, skb))
2012 chan->tx_send_head = NULL;
2013 else
2014 chan->tx_send_head = skb_queue_next(&chan->tx_q, skb);
2015
2016 l2cap_do_send(chan, tx_skb);
2017 BT_DBG("Sent txseq %u", control->txseq);
2018 }
2019
2020 BT_DBG("Sent %d, %u unacked, %u in ERTM queue", sent,
2021 chan->unacked_frames, skb_queue_len(&chan->tx_q));
2022
2023 return sent;
2024 }
2025
2026 static void l2cap_ertm_resend(struct l2cap_chan *chan)
2027 {
2028 struct l2cap_ctrl control;
2029 struct sk_buff *skb;
2030 struct sk_buff *tx_skb;
2031 u16 seq;
2032
2033 BT_DBG("chan %p", chan);
2034
2035 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
2036 return;
2037
2038 while (chan->retrans_list.head != L2CAP_SEQ_LIST_CLEAR) {
2039 seq = l2cap_seq_list_pop(&chan->retrans_list);
2040
2041 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, seq);
2042 if (!skb) {
2043 BT_DBG("Error: Can't retransmit seq %d, frame missing",
2044 seq);
2045 continue;
2046 }
2047
2048 bt_cb(skb)->l2cap.retries++;
2049 control = bt_cb(skb)->l2cap;
2050
2051 if (chan->max_tx != 0 &&
2052 bt_cb(skb)->l2cap.retries > chan->max_tx) {
2053 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
2054 l2cap_send_disconn_req(chan, ECONNRESET);
2055 l2cap_seq_list_clear(&chan->retrans_list);
2056 break;
2057 }
2058
2059 control.reqseq = chan->buffer_seq;
2060 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
2061 control.final = 1;
2062 else
2063 control.final = 0;
2064
2065 if (skb_cloned(skb)) {
2066 /* Cloned sk_buffs are read-only, so we need a
2067 * writeable copy
2068 */
2069 tx_skb = skb_copy(skb, GFP_KERNEL);
2070 } else {
2071 tx_skb = skb_clone(skb, GFP_KERNEL);
2072 }
2073
2074 if (!tx_skb) {
2075 l2cap_seq_list_clear(&chan->retrans_list);
2076 break;
2077 }
2078
2079 /* Update skb contents */
2080 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
2081 put_unaligned_le32(__pack_extended_control(&control),
2082 tx_skb->data + L2CAP_HDR_SIZE);
2083 } else {
2084 put_unaligned_le16(__pack_enhanced_control(&control),
2085 tx_skb->data + L2CAP_HDR_SIZE);
2086 }
2087
2088 /* Update FCS */
2089 if (chan->fcs == L2CAP_FCS_CRC16) {
2090 u16 fcs = crc16(0, (u8 *) tx_skb->data,
2091 tx_skb->len - L2CAP_FCS_SIZE);
2092 put_unaligned_le16(fcs, skb_tail_pointer(tx_skb) -
2093 L2CAP_FCS_SIZE);
2094 }
2095
2096 l2cap_do_send(chan, tx_skb);
2097
2098 BT_DBG("Resent txseq %d", control.txseq);
2099
2100 chan->last_acked_seq = chan->buffer_seq;
2101 }
2102 }
2103
2104 static void l2cap_retransmit(struct l2cap_chan *chan,
2105 struct l2cap_ctrl *control)
2106 {
2107 BT_DBG("chan %p, control %p", chan, control);
2108
2109 l2cap_seq_list_append(&chan->retrans_list, control->reqseq);
2110 l2cap_ertm_resend(chan);
2111 }
2112
2113 static void l2cap_retransmit_all(struct l2cap_chan *chan,
2114 struct l2cap_ctrl *control)
2115 {
2116 struct sk_buff *skb;
2117
2118 BT_DBG("chan %p, control %p", chan, control);
2119
2120 if (control->poll)
2121 set_bit(CONN_SEND_FBIT, &chan->conn_state);
2122
2123 l2cap_seq_list_clear(&chan->retrans_list);
2124
2125 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
2126 return;
2127
2128 if (chan->unacked_frames) {
2129 skb_queue_walk(&chan->tx_q, skb) {
2130 if (bt_cb(skb)->l2cap.txseq == control->reqseq ||
2131 skb == chan->tx_send_head)
2132 break;
2133 }
2134
2135 skb_queue_walk_from(&chan->tx_q, skb) {
2136 if (skb == chan->tx_send_head)
2137 break;
2138
2139 l2cap_seq_list_append(&chan->retrans_list,
2140 bt_cb(skb)->l2cap.txseq);
2141 }
2142
2143 l2cap_ertm_resend(chan);
2144 }
2145 }
2146
2147 static void l2cap_send_ack(struct l2cap_chan *chan)
2148 {
2149 struct l2cap_ctrl control;
2150 u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
2151 chan->last_acked_seq);
2152 int threshold;
2153
2154 BT_DBG("chan %p last_acked_seq %d buffer_seq %d",
2155 chan, chan->last_acked_seq, chan->buffer_seq);
2156
2157 memset(&control, 0, sizeof(control));
2158 control.sframe = 1;
2159
2160 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
2161 chan->rx_state == L2CAP_RX_STATE_RECV) {
2162 __clear_ack_timer(chan);
2163 control.super = L2CAP_SUPER_RNR;
2164 control.reqseq = chan->buffer_seq;
2165 l2cap_send_sframe(chan, &control);
2166 } else {
2167 if (!test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) {
2168 l2cap_ertm_send(chan);
2169 /* If any i-frames were sent, they included an ack */
2170 if (chan->buffer_seq == chan->last_acked_seq)
2171 frames_to_ack = 0;
2172 }
2173
2174 /* Ack now if the window is 3/4ths full.
2175 * Calculate without mul or div
2176 */
2177 threshold = chan->ack_win;
2178 threshold += threshold << 1;
2179 threshold >>= 2;
2180
2181 BT_DBG("frames_to_ack %u, threshold %d", frames_to_ack,
2182 threshold);
2183
2184 if (frames_to_ack >= threshold) {
2185 __clear_ack_timer(chan);
2186 control.super = L2CAP_SUPER_RR;
2187 control.reqseq = chan->buffer_seq;
2188 l2cap_send_sframe(chan, &control);
2189 frames_to_ack = 0;
2190 }
2191
2192 if (frames_to_ack)
2193 __set_ack_timer(chan);
2194 }
2195 }
2196
2197 static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
2198 struct msghdr *msg, int len,
2199 int count, struct sk_buff *skb)
2200 {
2201 struct l2cap_conn *conn = chan->conn;
2202 struct sk_buff **frag;
2203 int sent = 0;
2204
2205 if (!copy_from_iter_full(skb_put(skb, count), count, &msg->msg_iter))
2206 return -EFAULT;
2207
2208 sent += count;
2209 len -= count;
2210
2211 /* Continuation fragments (no L2CAP header) */
2212 frag = &skb_shinfo(skb)->frag_list;
2213 while (len) {
2214 struct sk_buff *tmp;
2215
2216 count = min_t(unsigned int, conn->mtu, len);
2217
2218 tmp = chan->ops->alloc_skb(chan, 0, count,
2219 msg->msg_flags & MSG_DONTWAIT);
2220 if (IS_ERR(tmp))
2221 return PTR_ERR(tmp);
2222
2223 *frag = tmp;
2224
2225 if (!copy_from_iter_full(skb_put(*frag, count), count,
2226 &msg->msg_iter))
2227 return -EFAULT;
2228
2229 sent += count;
2230 len -= count;
2231
2232 skb->len += (*frag)->len;
2233 skb->data_len += (*frag)->len;
2234
2235 frag = &(*frag)->next;
2236 }
2237
2238 return sent;
2239 }
2240
2241 static struct sk_buff *l2cap_create_connless_pdu(struct l2cap_chan *chan,
2242 struct msghdr *msg, size_t len)
2243 {
2244 struct l2cap_conn *conn = chan->conn;
2245 struct sk_buff *skb;
2246 int err, count, hlen = L2CAP_HDR_SIZE + L2CAP_PSMLEN_SIZE;
2247 struct l2cap_hdr *lh;
2248
2249 BT_DBG("chan %p psm 0x%2.2x len %zu", chan,
2250 __le16_to_cpu(chan->psm), len);
2251
2252 count = min_t(unsigned int, (conn->mtu - hlen), len);
2253
2254 skb = chan->ops->alloc_skb(chan, hlen, count,
2255 msg->msg_flags & MSG_DONTWAIT);
2256 if (IS_ERR(skb))
2257 return skb;
2258
2259 /* Create L2CAP header */
2260 lh = skb_put(skb, L2CAP_HDR_SIZE);
2261 lh->cid = cpu_to_le16(chan->dcid);
2262 lh->len = cpu_to_le16(len + L2CAP_PSMLEN_SIZE);
2263 put_unaligned(chan->psm, (__le16 *) skb_put(skb, L2CAP_PSMLEN_SIZE));
2264
2265 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2266 if (unlikely(err < 0)) {
2267 kfree_skb(skb);
2268 return ERR_PTR(err);
2269 }
2270 return skb;
2271 }
2272
2273 static struct sk_buff *l2cap_create_basic_pdu(struct l2cap_chan *chan,
2274 struct msghdr *msg, size_t len)
2275 {
2276 struct l2cap_conn *conn = chan->conn;
2277 struct sk_buff *skb;
2278 int err, count;
2279 struct l2cap_hdr *lh;
2280
2281 BT_DBG("chan %p len %zu", chan, len);
2282
2283 count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len);
2284
2285 skb = chan->ops->alloc_skb(chan, L2CAP_HDR_SIZE, count,
2286 msg->msg_flags & MSG_DONTWAIT);
2287 if (IS_ERR(skb))
2288 return skb;
2289
2290 /* Create L2CAP header */
2291 lh = skb_put(skb, L2CAP_HDR_SIZE);
2292 lh->cid = cpu_to_le16(chan->dcid);
2293 lh->len = cpu_to_le16(len);
2294
2295 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2296 if (unlikely(err < 0)) {
2297 kfree_skb(skb);
2298 return ERR_PTR(err);
2299 }
2300 return skb;
2301 }
2302
2303 static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan,
2304 struct msghdr *msg, size_t len,
2305 u16 sdulen)
2306 {
2307 struct l2cap_conn *conn = chan->conn;
2308 struct sk_buff *skb;
2309 int err, count, hlen;
2310 struct l2cap_hdr *lh;
2311
2312 BT_DBG("chan %p len %zu", chan, len);
2313
2314 if (!conn)
2315 return ERR_PTR(-ENOTCONN);
2316
2317 hlen = __ertm_hdr_size(chan);
2318
2319 if (sdulen)
2320 hlen += L2CAP_SDULEN_SIZE;
2321
2322 if (chan->fcs == L2CAP_FCS_CRC16)
2323 hlen += L2CAP_FCS_SIZE;
2324
2325 count = min_t(unsigned int, (conn->mtu - hlen), len);
2326
2327 skb = chan->ops->alloc_skb(chan, hlen, count,
2328 msg->msg_flags & MSG_DONTWAIT);
2329 if (IS_ERR(skb))
2330 return skb;
2331
2332 /* Create L2CAP header */
2333 lh = skb_put(skb, L2CAP_HDR_SIZE);
2334 lh->cid = cpu_to_le16(chan->dcid);
2335 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2336
2337 /* Control header is populated later */
2338 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
2339 put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
2340 else
2341 put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
2342
2343 if (sdulen)
2344 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2345
2346 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2347 if (unlikely(err < 0)) {
2348 kfree_skb(skb);
2349 return ERR_PTR(err);
2350 }
2351
2352 bt_cb(skb)->l2cap.fcs = chan->fcs;
2353 bt_cb(skb)->l2cap.retries = 0;
2354 return skb;
2355 }
2356
2357 static int l2cap_segment_sdu(struct l2cap_chan *chan,
2358 struct sk_buff_head *seg_queue,
2359 struct msghdr *msg, size_t len)
2360 {
2361 struct sk_buff *skb;
2362 u16 sdu_len;
2363 size_t pdu_len;
2364 u8 sar;
2365
2366 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2367
2368 /* It is critical that ERTM PDUs fit in a single HCI fragment,
2369 * so fragmented skbs are not used. The HCI layer's handling
2370 * of fragmented skbs is not compatible with ERTM's queueing.
2371 */
2372
2373 /* PDU size is derived from the HCI MTU */
2374 pdu_len = chan->conn->mtu;
2375
2376 /* Constrain PDU size for BR/EDR connections */
2377 pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD);
2378
2379 /* Adjust for largest possible L2CAP overhead. */
2380 if (chan->fcs)
2381 pdu_len -= L2CAP_FCS_SIZE;
2382
2383 pdu_len -= __ertm_hdr_size(chan);
2384
2385 /* Remote device may have requested smaller PDUs */
2386 pdu_len = min_t(size_t, pdu_len, chan->remote_mps);
2387
2388 if (len <= pdu_len) {
2389 sar = L2CAP_SAR_UNSEGMENTED;
2390 sdu_len = 0;
2391 pdu_len = len;
2392 } else {
2393 sar = L2CAP_SAR_START;
2394 sdu_len = len;
2395 }
2396
2397 while (len > 0) {
2398 skb = l2cap_create_iframe_pdu(chan, msg, pdu_len, sdu_len);
2399
2400 if (IS_ERR(skb)) {
2401 __skb_queue_purge(seg_queue);
2402 return PTR_ERR(skb);
2403 }
2404
2405 bt_cb(skb)->l2cap.sar = sar;
2406 __skb_queue_tail(seg_queue, skb);
2407
2408 len -= pdu_len;
2409 if (sdu_len)
2410 sdu_len = 0;
2411
2412 if (len <= pdu_len) {
2413 sar = L2CAP_SAR_END;
2414 pdu_len = len;
2415 } else {
2416 sar = L2CAP_SAR_CONTINUE;
2417 }
2418 }
2419
2420 return 0;
2421 }
2422
2423 static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan,
2424 struct msghdr *msg,
2425 size_t len, u16 sdulen)
2426 {
2427 struct l2cap_conn *conn = chan->conn;
2428 struct sk_buff *skb;
2429 int err, count, hlen;
2430 struct l2cap_hdr *lh;
2431
2432 BT_DBG("chan %p len %zu", chan, len);
2433
2434 if (!conn)
2435 return ERR_PTR(-ENOTCONN);
2436
2437 hlen = L2CAP_HDR_SIZE;
2438
2439 if (sdulen)
2440 hlen += L2CAP_SDULEN_SIZE;
2441
2442 count = min_t(unsigned int, (conn->mtu - hlen), len);
2443
2444 skb = chan->ops->alloc_skb(chan, hlen, count,
2445 msg->msg_flags & MSG_DONTWAIT);
2446 if (IS_ERR(skb))
2447 return skb;
2448
2449 /* Create L2CAP header */
2450 lh = skb_put(skb, L2CAP_HDR_SIZE);
2451 lh->cid = cpu_to_le16(chan->dcid);
2452 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2453
2454 if (sdulen)
2455 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2456
2457 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2458 if (unlikely(err < 0)) {
2459 kfree_skb(skb);
2460 return ERR_PTR(err);
2461 }
2462
2463 return skb;
2464 }
2465
2466 static int l2cap_segment_le_sdu(struct l2cap_chan *chan,
2467 struct sk_buff_head *seg_queue,
2468 struct msghdr *msg, size_t len)
2469 {
2470 struct sk_buff *skb;
2471 size_t pdu_len;
2472 u16 sdu_len;
2473
2474 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2475
2476 sdu_len = len;
2477 pdu_len = chan->remote_mps - L2CAP_SDULEN_SIZE;
2478
2479 while (len > 0) {
2480 if (len <= pdu_len)
2481 pdu_len = len;
2482
2483 skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len);
2484 if (IS_ERR(skb)) {
2485 __skb_queue_purge(seg_queue);
2486 return PTR_ERR(skb);
2487 }
2488
2489 __skb_queue_tail(seg_queue, skb);
2490
2491 len -= pdu_len;
2492
2493 if (sdu_len) {
2494 sdu_len = 0;
2495 pdu_len += L2CAP_SDULEN_SIZE;
2496 }
2497 }
2498
2499 return 0;
2500 }
2501
2502 static void l2cap_le_flowctl_send(struct l2cap_chan *chan)
2503 {
2504 int sent = 0;
2505
2506 BT_DBG("chan %p", chan);
2507
2508 while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) {
2509 l2cap_do_send(chan, skb_dequeue(&chan->tx_q));
2510 chan->tx_credits--;
2511 sent++;
2512 }
2513
2514 BT_DBG("Sent %d credits %u queued %u", sent, chan->tx_credits,
2515 skb_queue_len(&chan->tx_q));
2516 }
2517
2518 int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len)
2519 {
2520 struct sk_buff *skb;
2521 int err;
2522 struct sk_buff_head seg_queue;
2523
2524 if (!chan->conn)
2525 return -ENOTCONN;
2526
2527 /* Connectionless channel */
2528 if (chan->chan_type == L2CAP_CHAN_CONN_LESS) {
2529 skb = l2cap_create_connless_pdu(chan, msg, len);
2530 if (IS_ERR(skb))
2531 return PTR_ERR(skb);
2532
2533 l2cap_do_send(chan, skb);
2534 return len;
2535 }
2536
2537 switch (chan->mode) {
2538 case L2CAP_MODE_LE_FLOWCTL:
2539 case L2CAP_MODE_EXT_FLOWCTL:
2540 /* Check outgoing MTU */
2541 if (len > chan->omtu)
2542 return -EMSGSIZE;
2543
2544 __skb_queue_head_init(&seg_queue);
2545
2546 err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len);
2547
2548 if (chan->state != BT_CONNECTED) {
2549 __skb_queue_purge(&seg_queue);
2550 err = -ENOTCONN;
2551 }
2552
2553 if (err)
2554 return err;
2555
2556 skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
2557
2558 l2cap_le_flowctl_send(chan);
2559
2560 if (!chan->tx_credits)
2561 chan->ops->suspend(chan);
2562
2563 err = len;
2564
2565 break;
2566
2567 case L2CAP_MODE_BASIC:
2568 /* Check outgoing MTU */
2569 if (len > chan->omtu)
2570 return -EMSGSIZE;
2571
2572 /* Create a basic PDU */
2573 skb = l2cap_create_basic_pdu(chan, msg, len);
2574 if (IS_ERR(skb))
2575 return PTR_ERR(skb);
2576
2577 l2cap_do_send(chan, skb);
2578 err = len;
2579 break;
2580
2581 case L2CAP_MODE_ERTM:
2582 case L2CAP_MODE_STREAMING:
2583 /* Check outgoing MTU */
2584 if (len > chan->omtu) {
2585 err = -EMSGSIZE;
2586 break;
2587 }
2588
2589 __skb_queue_head_init(&seg_queue);
2590
2591 /* Do segmentation before calling in to the state machine,
2592 * since it's possible to block while waiting for memory
2593 * allocation.
2594 */
2595 err = l2cap_segment_sdu(chan, &seg_queue, msg, len);
2596
2597 if (err)
2598 break;
2599
2600 if (chan->mode == L2CAP_MODE_ERTM)
2601 l2cap_tx(chan, NULL, &seg_queue, L2CAP_EV_DATA_REQUEST);
2602 else
2603 l2cap_streaming_send(chan, &seg_queue);
2604
2605 err = len;
2606
2607 /* If the skbs were not queued for sending, they'll still be in
2608 * seg_queue and need to be purged.
2609 */
2610 __skb_queue_purge(&seg_queue);
2611 break;
2612
2613 default:
2614 BT_DBG("bad state %1.1x", chan->mode);
2615 err = -EBADFD;
2616 }
2617
2618 return err;
2619 }
2620 EXPORT_SYMBOL_GPL(l2cap_chan_send);
2621
2622 static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq)
2623 {
2624 struct l2cap_ctrl control;
2625 u16 seq;
2626
2627 BT_DBG("chan %p, txseq %u", chan, txseq);
2628
2629 memset(&control, 0, sizeof(control));
2630 control.sframe = 1;
2631 control.super = L2CAP_SUPER_SREJ;
2632
2633 for (seq = chan->expected_tx_seq; seq != txseq;
2634 seq = __next_seq(chan, seq)) {
2635 if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) {
2636 control.reqseq = seq;
2637 l2cap_send_sframe(chan, &control);
2638 l2cap_seq_list_append(&chan->srej_list, seq);
2639 }
2640 }
2641
2642 chan->expected_tx_seq = __next_seq(chan, txseq);
2643 }
2644
2645 static void l2cap_send_srej_tail(struct l2cap_chan *chan)
2646 {
2647 struct l2cap_ctrl control;
2648
2649 BT_DBG("chan %p", chan);
2650
2651 if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR)
2652 return;
2653
2654 memset(&control, 0, sizeof(control));
2655 control.sframe = 1;
2656 control.super = L2CAP_SUPER_SREJ;
2657 control.reqseq = chan->srej_list.tail;
2658 l2cap_send_sframe(chan, &control);
2659 }
2660
2661 static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq)
2662 {
2663 struct l2cap_ctrl control;
2664 u16 initial_head;
2665 u16 seq;
2666
2667 BT_DBG("chan %p, txseq %u", chan, txseq);
2668
2669 memset(&control, 0, sizeof(control));
2670 control.sframe = 1;
2671 control.super = L2CAP_SUPER_SREJ;
2672
2673 /* Capture initial list head to allow only one pass through the list. */
2674 initial_head = chan->srej_list.head;
2675
2676 do {
2677 seq = l2cap_seq_list_pop(&chan->srej_list);
2678 if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR)
2679 break;
2680
2681 control.reqseq = seq;
2682 l2cap_send_sframe(chan, &control);
2683 l2cap_seq_list_append(&chan->srej_list, seq);
2684 } while (chan->srej_list.head != initial_head);
2685 }
2686
2687 static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq)
2688 {
2689 struct sk_buff *acked_skb;
2690 u16 ackseq;
2691
2692 BT_DBG("chan %p, reqseq %u", chan, reqseq);
2693
2694 if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq)
2695 return;
2696
2697 BT_DBG("expected_ack_seq %u, unacked_frames %u",
2698 chan->expected_ack_seq, chan->unacked_frames);
2699
2700 for (ackseq = chan->expected_ack_seq; ackseq != reqseq;
2701 ackseq = __next_seq(chan, ackseq)) {
2702
2703 acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq);
2704 if (acked_skb) {
2705 skb_unlink(acked_skb, &chan->tx_q);
2706 kfree_skb(acked_skb);
2707 chan->unacked_frames--;
2708 }
2709 }
2710
2711 chan->expected_ack_seq = reqseq;
2712
2713 if (chan->unacked_frames == 0)
2714 __clear_retrans_timer(chan);
2715
2716 BT_DBG("unacked_frames %u", chan->unacked_frames);
2717 }
2718
2719 static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan)
2720 {
2721 BT_DBG("chan %p", chan);
2722
2723 chan->expected_tx_seq = chan->buffer_seq;
2724 l2cap_seq_list_clear(&chan->srej_list);
2725 skb_queue_purge(&chan->srej_q);
2726 chan->rx_state = L2CAP_RX_STATE_RECV;
2727 }
2728
2729 static void l2cap_tx_state_xmit(struct l2cap_chan *chan,
2730 struct l2cap_ctrl *control,
2731 struct sk_buff_head *skbs, u8 event)
2732 {
2733 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2734 event);
2735
2736 switch (event) {
2737 case L2CAP_EV_DATA_REQUEST:
2738 if (chan->tx_send_head == NULL)
2739 chan->tx_send_head = skb_peek(skbs);
2740
2741 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2742 l2cap_ertm_send(chan);
2743 break;
2744 case L2CAP_EV_LOCAL_BUSY_DETECTED:
2745 BT_DBG("Enter LOCAL_BUSY");
2746 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2747
2748 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2749 /* The SREJ_SENT state must be aborted if we are to
2750 * enter the LOCAL_BUSY state.
2751 */
2752 l2cap_abort_rx_srej_sent(chan);
2753 }
2754
2755 l2cap_send_ack(chan);
2756
2757 break;
2758 case L2CAP_EV_LOCAL_BUSY_CLEAR:
2759 BT_DBG("Exit LOCAL_BUSY");
2760 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2761
2762 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2763 struct l2cap_ctrl local_control;
2764
2765 memset(&local_control, 0, sizeof(local_control));
2766 local_control.sframe = 1;
2767 local_control.super = L2CAP_SUPER_RR;
2768 local_control.poll = 1;
2769 local_control.reqseq = chan->buffer_seq;
2770 l2cap_send_sframe(chan, &local_control);
2771
2772 chan->retry_count = 1;
2773 __set_monitor_timer(chan);
2774 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2775 }
2776 break;
2777 case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2778 l2cap_process_reqseq(chan, control->reqseq);
2779 break;
2780 case L2CAP_EV_EXPLICIT_POLL:
2781 l2cap_send_rr_or_rnr(chan, 1);
2782 chan->retry_count = 1;
2783 __set_monitor_timer(chan);
2784 __clear_ack_timer(chan);
2785 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2786 break;
2787 case L2CAP_EV_RETRANS_TO:
2788 l2cap_send_rr_or_rnr(chan, 1);
2789 chan->retry_count = 1;
2790 __set_monitor_timer(chan);
2791 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2792 break;
2793 case L2CAP_EV_RECV_FBIT:
2794 /* Nothing to process */
2795 break;
2796 default:
2797 break;
2798 }
2799 }
2800
2801 static void l2cap_tx_state_wait_f(struct l2cap_chan *chan,
2802 struct l2cap_ctrl *control,
2803 struct sk_buff_head *skbs, u8 event)
2804 {
2805 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2806 event);
2807
2808 switch (event) {
2809 case L2CAP_EV_DATA_REQUEST:
2810 if (chan->tx_send_head == NULL)
2811 chan->tx_send_head = skb_peek(skbs);
2812 /* Queue data, but don't send. */
2813 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2814 break;
2815 case L2CAP_EV_LOCAL_BUSY_DETECTED:
2816 BT_DBG("Enter LOCAL_BUSY");
2817 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2818
2819 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2820 /* The SREJ_SENT state must be aborted if we are to
2821 * enter the LOCAL_BUSY state.
2822 */
2823 l2cap_abort_rx_srej_sent(chan);
2824 }
2825
2826 l2cap_send_ack(chan);
2827
2828 break;
2829 case L2CAP_EV_LOCAL_BUSY_CLEAR:
2830 BT_DBG("Exit LOCAL_BUSY");
2831 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2832
2833 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2834 struct l2cap_ctrl local_control;
2835 memset(&local_control, 0, sizeof(local_control));
2836 local_control.sframe = 1;
2837 local_control.super = L2CAP_SUPER_RR;
2838 local_control.poll = 1;
2839 local_control.reqseq = chan->buffer_seq;
2840 l2cap_send_sframe(chan, &local_control);
2841
2842 chan->retry_count = 1;
2843 __set_monitor_timer(chan);
2844 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2845 }
2846 break;
2847 case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2848 l2cap_process_reqseq(chan, control->reqseq);
2849 fallthrough;
2850
2851 case L2CAP_EV_RECV_FBIT:
2852 if (control && control->final) {
2853 __clear_monitor_timer(chan);
2854 if (chan->unacked_frames > 0)
2855 __set_retrans_timer(chan);
2856 chan->retry_count = 0;
2857 chan->tx_state = L2CAP_TX_STATE_XMIT;
2858 BT_DBG("recv fbit tx_state 0x2.2%x", chan->tx_state);
2859 }
2860 break;
2861 case L2CAP_EV_EXPLICIT_POLL:
2862 /* Ignore */
2863 break;
2864 case L2CAP_EV_MONITOR_TO:
2865 if (chan->max_tx == 0 || chan->retry_count < chan->max_tx) {
2866 l2cap_send_rr_or_rnr(chan, 1);
2867 __set_monitor_timer(chan);
2868 chan->retry_count++;
2869 } else {
2870 l2cap_send_disconn_req(chan, ECONNABORTED);
2871 }
2872 break;
2873 default:
2874 break;
2875 }
2876 }
2877
2878 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
2879 struct sk_buff_head *skbs, u8 event)
2880 {
2881 BT_DBG("chan %p, control %p, skbs %p, event %d, state %d",
2882 chan, control, skbs, event, chan->tx_state);
2883
2884 switch (chan->tx_state) {
2885 case L2CAP_TX_STATE_XMIT:
2886 l2cap_tx_state_xmit(chan, control, skbs, event);
2887 break;
2888 case L2CAP_TX_STATE_WAIT_F:
2889 l2cap_tx_state_wait_f(chan, control, skbs, event);
2890 break;
2891 default:
2892 /* Ignore event */
2893 break;
2894 }
2895 }
2896
2897 static void l2cap_pass_to_tx(struct l2cap_chan *chan,
2898 struct l2cap_ctrl *control)
2899 {
2900 BT_DBG("chan %p, control %p", chan, control);
2901 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_REQSEQ_AND_FBIT);
2902 }
2903
2904 static void l2cap_pass_to_tx_fbit(struct l2cap_chan *chan,
2905 struct l2cap_ctrl *control)
2906 {
2907 BT_DBG("chan %p, control %p", chan, control);
2908 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_FBIT);
2909 }
2910
2911 /* Copy frame to all raw sockets on that connection */
2912 static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
2913 {
2914 struct sk_buff *nskb;
2915 struct l2cap_chan *chan;
2916
2917 BT_DBG("conn %p", conn);
2918
2919 mutex_lock(&conn->chan_lock);
2920
2921 list_for_each_entry(chan, &conn->chan_l, list) {
2922 if (chan->chan_type != L2CAP_CHAN_RAW)
2923 continue;
2924
2925 /* Don't send frame to the channel it came from */
2926 if (bt_cb(skb)->l2cap.chan == chan)
2927 continue;
2928
2929 nskb = skb_clone(skb, GFP_KERNEL);
2930 if (!nskb)
2931 continue;
2932 if (chan->ops->recv(chan, nskb))
2933 kfree_skb(nskb);
2934 }
2935
2936 mutex_unlock(&conn->chan_lock);
2937 }
2938
2939 /* ---- L2CAP signalling commands ---- */
2940 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code,
2941 u8 ident, u16 dlen, void *data)
2942 {
2943 struct sk_buff *skb, **frag;
2944 struct l2cap_cmd_hdr *cmd;
2945 struct l2cap_hdr *lh;
2946 int len, count;
2947
2948 BT_DBG("conn %p, code 0x%2.2x, ident 0x%2.2x, len %u",
2949 conn, code, ident, dlen);
2950
2951 if (conn->mtu < L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE)
2952 return NULL;
2953
2954 len = L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE + dlen;
2955 count = min_t(unsigned int, conn->mtu, len);
2956
2957 skb = bt_skb_alloc(count, GFP_KERNEL);
2958 if (!skb)
2959 return NULL;
2960
2961 lh = skb_put(skb, L2CAP_HDR_SIZE);
2962 lh->len = cpu_to_le16(L2CAP_CMD_HDR_SIZE + dlen);
2963
2964 if (conn->hcon->type == LE_LINK)
2965 lh->cid = cpu_to_le16(L2CAP_CID_LE_SIGNALING);
2966 else
2967 lh->cid = cpu_to_le16(L2CAP_CID_SIGNALING);
2968
2969 cmd = skb_put(skb, L2CAP_CMD_HDR_SIZE);
2970 cmd->code = code;
2971 cmd->ident = ident;
2972 cmd->len = cpu_to_le16(dlen);
2973
2974 if (dlen) {
2975 count -= L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE;
2976 skb_put_data(skb, data, count);
2977 data += count;
2978 }
2979
2980 len -= skb->len;
2981
2982 /* Continuation fragments (no L2CAP header) */
2983 frag = &skb_shinfo(skb)->frag_list;
2984 while (len) {
2985 count = min_t(unsigned int, conn->mtu, len);
2986
2987 *frag = bt_skb_alloc(count, GFP_KERNEL);
2988 if (!*frag)
2989 goto fail;
2990
2991 skb_put_data(*frag, data, count);
2992
2993 len -= count;
2994 data += count;
2995
2996 frag = &(*frag)->next;
2997 }
2998
2999 return skb;
3000
3001 fail:
3002 kfree_skb(skb);
3003 return NULL;
3004 }
3005
3006 static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen,
3007 unsigned long *val)
3008 {
3009 struct l2cap_conf_opt *opt = *ptr;
3010 int len;
3011
3012 len = L2CAP_CONF_OPT_SIZE + opt->len;
3013 *ptr += len;
3014
3015 *type = opt->type;
3016 *olen = opt->len;
3017
3018 switch (opt->len) {
3019 case 1:
3020 *val = *((u8 *) opt->val);
3021 break;
3022
3023 case 2:
3024 *val = get_unaligned_le16(opt->val);
3025 break;
3026
3027 case 4:
3028 *val = get_unaligned_le32(opt->val);
3029 break;
3030
3031 default:
3032 *val = (unsigned long) opt->val;
3033 break;
3034 }
3035
3036 BT_DBG("type 0x%2.2x len %u val 0x%lx", *type, opt->len, *val);
3037 return len;
3038 }
3039
3040 static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val, size_t size)
3041 {
3042 struct l2cap_conf_opt *opt = *ptr;
3043
3044 BT_DBG("type 0x%2.2x len %u val 0x%lx", type, len, val);
3045
3046 if (size < L2CAP_CONF_OPT_SIZE + len)
3047 return;
3048
3049 opt->type = type;
3050 opt->len = len;
3051
3052 switch (len) {
3053 case 1:
3054 *((u8 *) opt->val) = val;
3055 break;
3056
3057 case 2:
3058 put_unaligned_le16(val, opt->val);
3059 break;
3060
3061 case 4:
3062 put_unaligned_le32(val, opt->val);
3063 break;
3064
3065 default:
3066 memcpy(opt->val, (void *) val, len);
3067 break;
3068 }
3069
3070 *ptr += L2CAP_CONF_OPT_SIZE + len;
3071 }
3072
3073 static void l2cap_add_opt_efs(void **ptr, struct l2cap_chan *chan, size_t size)
3074 {
3075 struct l2cap_conf_efs efs;
3076
3077 switch (chan->mode) {
3078 case L2CAP_MODE_ERTM:
3079 efs.id = chan->local_id;
3080 efs.stype = chan->local_stype;
3081 efs.msdu = cpu_to_le16(chan->local_msdu);
3082 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
3083 efs.acc_lat = cpu_to_le32(L2CAP_DEFAULT_ACC_LAT);
3084 efs.flush_to = cpu_to_le32(L2CAP_EFS_DEFAULT_FLUSH_TO);
3085 break;
3086
3087 case L2CAP_MODE_STREAMING:
3088 efs.id = 1;
3089 efs.stype = L2CAP_SERV_BESTEFFORT;
3090 efs.msdu = cpu_to_le16(chan->local_msdu);
3091 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
3092 efs.acc_lat = 0;
3093 efs.flush_to = 0;
3094 break;
3095
3096 default:
3097 return;
3098 }
3099
3100 l2cap_add_conf_opt(ptr, L2CAP_CONF_EFS, sizeof(efs),
3101 (unsigned long) &efs, size);
3102 }
3103
3104 static void l2cap_ack_timeout(struct work_struct *work)
3105 {
3106 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
3107 ack_timer.work);
3108 u16 frames_to_ack;
3109
3110 BT_DBG("chan %p", chan);
3111
3112 l2cap_chan_lock(chan);
3113
3114 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
3115 chan->last_acked_seq);
3116
3117 if (frames_to_ack)
3118 l2cap_send_rr_or_rnr(chan, 0);
3119
3120 l2cap_chan_unlock(chan);
3121 l2cap_chan_put(chan);
3122 }
3123
3124 int l2cap_ertm_init(struct l2cap_chan *chan)
3125 {
3126 int err;
3127
3128 chan->next_tx_seq = 0;
3129 chan->expected_tx_seq = 0;
3130 chan->expected_ack_seq = 0;
3131 chan->unacked_frames = 0;
3132 chan->buffer_seq = 0;
3133 chan->frames_sent = 0;
3134 chan->last_acked_seq = 0;
3135 chan->sdu = NULL;
3136 chan->sdu_last_frag = NULL;
3137 chan->sdu_len = 0;
3138
3139 skb_queue_head_init(&chan->tx_q);
3140
3141 if (chan->mode != L2CAP_MODE_ERTM)
3142 return 0;
3143
3144 chan->rx_state = L2CAP_RX_STATE_RECV;
3145 chan->tx_state = L2CAP_TX_STATE_XMIT;
3146
3147 skb_queue_head_init(&chan->srej_q);
3148
3149 err = l2cap_seq_list_init(&chan->srej_list, chan->tx_win);
3150 if (err < 0)
3151 return err;
3152
3153 err = l2cap_seq_list_init(&chan->retrans_list, chan->remote_tx_win);
3154 if (err < 0)
3155 l2cap_seq_list_free(&chan->srej_list);
3156
3157 return err;
3158 }
3159
3160 static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
3161 {
3162 switch (mode) {
3163 case L2CAP_MODE_STREAMING:
3164 case L2CAP_MODE_ERTM:
3165 if (l2cap_mode_supported(mode, remote_feat_mask))
3166 return mode;
3167 fallthrough;
3168 default:
3169 return L2CAP_MODE_BASIC;
3170 }
3171 }
3172
3173 static inline bool __l2cap_ews_supported(struct l2cap_conn *conn)
3174 {
3175 return (conn->feat_mask & L2CAP_FEAT_EXT_WINDOW);
3176 }
3177
3178 static inline bool __l2cap_efs_supported(struct l2cap_conn *conn)
3179 {
3180 return (conn->feat_mask & L2CAP_FEAT_EXT_FLOW);
3181 }
3182
3183 static void __l2cap_set_ertm_timeouts(struct l2cap_chan *chan,
3184 struct l2cap_conf_rfc *rfc)
3185 {
3186 rfc->retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO);
3187 rfc->monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO);
3188 }
3189
3190 static inline void l2cap_txwin_setup(struct l2cap_chan *chan)
3191 {
3192 if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW &&
3193 __l2cap_ews_supported(chan->conn)) {
3194 /* use extended control field */
3195 set_bit(FLAG_EXT_CTRL, &chan->flags);
3196 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
3197 } else {
3198 chan->tx_win = min_t(u16, chan->tx_win,
3199 L2CAP_DEFAULT_TX_WINDOW);
3200 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
3201 }
3202 chan->ack_win = chan->tx_win;
3203 }
3204
3205 static void l2cap_mtu_auto(struct l2cap_chan *chan)
3206 {
3207 struct hci_conn *conn = chan->conn->hcon;
3208
3209 chan->imtu = L2CAP_DEFAULT_MIN_MTU;
3210
3211 /* The 2-DH1 packet has between 2 and 56 information bytes
3212 * (including the 2-byte payload header)
3213 */
3214 if (!(conn->pkt_type & HCI_2DH1))
3215 chan->imtu = 54;
3216
3217 /* The 3-DH1 packet has between 2 and 85 information bytes
3218 * (including the 2-byte payload header)
3219 */
3220 if (!(conn->pkt_type & HCI_3DH1))
3221 chan->imtu = 83;
3222
3223 /* The 2-DH3 packet has between 2 and 369 information bytes
3224 * (including the 2-byte payload header)
3225 */
3226 if (!(conn->pkt_type & HCI_2DH3))
3227 chan->imtu = 367;
3228
3229 /* The 3-DH3 packet has between 2 and 554 information bytes
3230 * (including the 2-byte payload header)
3231 */
3232 if (!(conn->pkt_type & HCI_3DH3))
3233 chan->imtu = 552;
3234
3235 /* The 2-DH5 packet has between 2 and 681 information bytes
3236 * (including the 2-byte payload header)
3237 */
3238 if (!(conn->pkt_type & HCI_2DH5))
3239 chan->imtu = 679;
3240
3241 /* The 3-DH5 packet has between 2 and 1023 information bytes
3242 * (including the 2-byte payload header)
3243 */
3244 if (!(conn->pkt_type & HCI_3DH5))
3245 chan->imtu = 1021;
3246 }
3247
3248 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
3249 {
3250 struct l2cap_conf_req *req = data;
3251 struct l2cap_conf_rfc rfc = { .mode = chan->mode };
3252 void *ptr = req->data;
3253 void *endptr = data + data_size;
3254 u16 size;
3255
3256 BT_DBG("chan %p", chan);
3257
3258 if (chan->num_conf_req || chan->num_conf_rsp)
3259 goto done;
3260
3261 switch (chan->mode) {
3262 case L2CAP_MODE_STREAMING:
3263 case L2CAP_MODE_ERTM:
3264 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state))
3265 break;
3266
3267 if (__l2cap_efs_supported(chan->conn))
3268 set_bit(FLAG_EFS_ENABLE, &chan->flags);
3269
3270 fallthrough;
3271 default:
3272 chan->mode = l2cap_select_mode(rfc.mode, chan->conn->feat_mask);
3273 break;
3274 }
3275
3276 done:
3277 if (chan->imtu != L2CAP_DEFAULT_MTU) {
3278 if (!chan->imtu)
3279 l2cap_mtu_auto(chan);
3280 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu,
3281 endptr - ptr);
3282 }
3283
3284 switch (chan->mode) {
3285 case L2CAP_MODE_BASIC:
3286 if (disable_ertm)
3287 break;
3288
3289 if (!(chan->conn->feat_mask & L2CAP_FEAT_ERTM) &&
3290 !(chan->conn->feat_mask & L2CAP_FEAT_STREAMING))
3291 break;
3292
3293 rfc.mode = L2CAP_MODE_BASIC;
3294 rfc.txwin_size = 0;
3295 rfc.max_transmit = 0;
3296 rfc.retrans_timeout = 0;
3297 rfc.monitor_timeout = 0;
3298 rfc.max_pdu_size = 0;
3299
3300 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3301 (unsigned long) &rfc, endptr - ptr);
3302 break;
3303
3304 case L2CAP_MODE_ERTM:
3305 rfc.mode = L2CAP_MODE_ERTM;
3306 rfc.max_transmit = chan->max_tx;
3307
3308 __l2cap_set_ertm_timeouts(chan, &rfc);
3309
3310 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3311 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3312 L2CAP_FCS_SIZE);
3313 rfc.max_pdu_size = cpu_to_le16(size);
3314
3315 l2cap_txwin_setup(chan);
3316
3317 rfc.txwin_size = min_t(u16, chan->tx_win,
3318 L2CAP_DEFAULT_TX_WINDOW);
3319
3320 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3321 (unsigned long) &rfc, endptr - ptr);
3322
3323 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3324 l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
3325
3326 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
3327 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3328 chan->tx_win, endptr - ptr);
3329
3330 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3331 if (chan->fcs == L2CAP_FCS_NONE ||
3332 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3333 chan->fcs = L2CAP_FCS_NONE;
3334 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3335 chan->fcs, endptr - ptr);
3336 }
3337 break;
3338
3339 case L2CAP_MODE_STREAMING:
3340 l2cap_txwin_setup(chan);
3341 rfc.mode = L2CAP_MODE_STREAMING;
3342 rfc.txwin_size = 0;
3343 rfc.max_transmit = 0;
3344 rfc.retrans_timeout = 0;
3345 rfc.monitor_timeout = 0;
3346
3347 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3348 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3349 L2CAP_FCS_SIZE);
3350 rfc.max_pdu_size = cpu_to_le16(size);
3351
3352 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3353 (unsigned long) &rfc, endptr - ptr);
3354
3355 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3356 l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
3357
3358 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3359 if (chan->fcs == L2CAP_FCS_NONE ||
3360 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3361 chan->fcs = L2CAP_FCS_NONE;
3362 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3363 chan->fcs, endptr - ptr);
3364 }
3365 break;
3366 }
3367
3368 req->dcid = cpu_to_le16(chan->dcid);
3369 req->flags = cpu_to_le16(0);
3370
3371 return ptr - data;
3372 }
3373
3374 static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
3375 {
3376 struct l2cap_conf_rsp *rsp = data;
3377 void *ptr = rsp->data;
3378 void *endptr = data + data_size;
3379 void *req = chan->conf_req;
3380 int len = chan->conf_len;
3381 int type, hint, olen;
3382 unsigned long val;
3383 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
3384 struct l2cap_conf_efs efs;
3385 u8 remote_efs = 0;
3386 u16 mtu = L2CAP_DEFAULT_MTU;
3387 u16 result = L2CAP_CONF_SUCCESS;
3388 u16 size;
3389
3390 BT_DBG("chan %p", chan);
3391
3392 while (len >= L2CAP_CONF_OPT_SIZE) {
3393 len -= l2cap_get_conf_opt(&req, &type, &olen, &val);
3394 if (len < 0)
3395 break;
3396
3397 hint = type & L2CAP_CONF_HINT;
3398 type &= L2CAP_CONF_MASK;
3399
3400 switch (type) {
3401 case L2CAP_CONF_MTU:
3402 if (olen != 2)
3403 break;
3404 mtu = val;
3405 break;
3406
3407 case L2CAP_CONF_FLUSH_TO:
3408 if (olen != 2)
3409 break;
3410 chan->flush_to = val;
3411 break;
3412
3413 case L2CAP_CONF_QOS:
3414 break;
3415
3416 case L2CAP_CONF_RFC:
3417 if (olen != sizeof(rfc))
3418 break;
3419 memcpy(&rfc, (void *) val, olen);
3420 break;
3421
3422 case L2CAP_CONF_FCS:
3423 if (olen != 1)
3424 break;
3425 if (val == L2CAP_FCS_NONE)
3426 set_bit(CONF_RECV_NO_FCS, &chan->conf_state);
3427 break;
3428
3429 case L2CAP_CONF_EFS:
3430 if (olen != sizeof(efs))
3431 break;
3432 remote_efs = 1;
3433 memcpy(&efs, (void *) val, olen);
3434 break;
3435
3436 case L2CAP_CONF_EWS:
3437 if (olen != 2)
3438 break;
3439 return -ECONNREFUSED;
3440
3441 default:
3442 if (hint)
3443 break;
3444 result = L2CAP_CONF_UNKNOWN;
3445 l2cap_add_conf_opt(&ptr, (u8)type, sizeof(u8), type, endptr - ptr);
3446 break;
3447 }
3448 }
3449
3450 if (chan->num_conf_rsp || chan->num_conf_req > 1)
3451 goto done;
3452
3453 switch (chan->mode) {
3454 case L2CAP_MODE_STREAMING:
3455 case L2CAP_MODE_ERTM:
3456 if (!test_bit(CONF_STATE2_DEVICE, &chan->conf_state)) {
3457 chan->mode = l2cap_select_mode(rfc.mode,
3458 chan->conn->feat_mask);
3459 break;
3460 }
3461
3462 if (remote_efs) {
3463 if (__l2cap_efs_supported(chan->conn))
3464 set_bit(FLAG_EFS_ENABLE, &chan->flags);
3465 else
3466 return -ECONNREFUSED;
3467 }
3468
3469 if (chan->mode != rfc.mode)
3470 return -ECONNREFUSED;
3471
3472 break;
3473 }
3474
3475 done:
3476 if (chan->mode != rfc.mode) {
3477 result = L2CAP_CONF_UNACCEPT;
3478 rfc.mode = chan->mode;
3479
3480 if (chan->num_conf_rsp == 1)
3481 return -ECONNREFUSED;
3482
3483 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3484 (unsigned long) &rfc, endptr - ptr);
3485 }
3486
3487 if (result == L2CAP_CONF_SUCCESS) {
3488 /* Configure output options and let the other side know
3489 * which ones we don't like. */
3490
3491 if (mtu < L2CAP_DEFAULT_MIN_MTU)
3492 result = L2CAP_CONF_UNACCEPT;
3493 else {
3494 chan->omtu = mtu;
3495 set_bit(CONF_MTU_DONE, &chan->conf_state);
3496 }
3497 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->omtu, endptr - ptr);
3498
3499 if (remote_efs) {
3500 if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
3501 efs.stype != L2CAP_SERV_NOTRAFIC &&
3502 efs.stype != chan->local_stype) {
3503
3504 result = L2CAP_CONF_UNACCEPT;
3505
3506 if (chan->num_conf_req >= 1)
3507 return -ECONNREFUSED;
3508
3509 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
3510 sizeof(efs),
3511 (unsigned long) &efs, endptr - ptr);
3512 } else {
3513 /* Send PENDING Conf Rsp */
3514 result = L2CAP_CONF_PENDING;
3515 set_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
3516 }
3517 }
3518
3519 switch (rfc.mode) {
3520 case L2CAP_MODE_BASIC:
3521 chan->fcs = L2CAP_FCS_NONE;
3522 set_bit(CONF_MODE_DONE, &chan->conf_state);
3523 break;
3524
3525 case L2CAP_MODE_ERTM:
3526 if (!test_bit(CONF_EWS_RECV, &chan->conf_state))
3527 chan->remote_tx_win = rfc.txwin_size;
3528 else
3529 rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW;
3530
3531 chan->remote_max_tx = rfc.max_transmit;
3532
3533 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
3534 chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
3535 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
3536 rfc.max_pdu_size = cpu_to_le16(size);
3537 chan->remote_mps = size;
3538
3539 __l2cap_set_ertm_timeouts(chan, &rfc);
3540
3541 set_bit(CONF_MODE_DONE, &chan->conf_state);
3542
3543 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
3544 sizeof(rfc), (unsigned long) &rfc, endptr - ptr);
3545
3546 if (remote_efs &&
3547 test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
3548 chan->remote_id = efs.id;
3549 chan->remote_stype = efs.stype;
3550 chan->remote_msdu = le16_to_cpu(efs.msdu);
3551 chan->remote_flush_to =
3552 le32_to_cpu(efs.flush_to);
3553 chan->remote_acc_lat =
3554 le32_to_cpu(efs.acc_lat);
3555 chan->remote_sdu_itime =
3556 le32_to_cpu(efs.sdu_itime);
3557 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
3558 sizeof(efs),
3559 (unsigned long) &efs, endptr - ptr);
3560 }
3561 break;
3562
3563 case L2CAP_MODE_STREAMING:
3564 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
3565 chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
3566 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
3567 rfc.max_pdu_size = cpu_to_le16(size);
3568 chan->remote_mps = size;
3569
3570 set_bit(CONF_MODE_DONE, &chan->conf_state);
3571
3572 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3573 (unsigned long) &rfc, endptr - ptr);
3574
3575 break;
3576
3577 default:
3578 result = L2CAP_CONF_UNACCEPT;
3579
3580 memset(&rfc, 0, sizeof(rfc));
3581 rfc.mode = chan->mode;
3582 }
3583
3584 if (result == L2CAP_CONF_SUCCESS)
3585 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
3586 }
3587 rsp->scid = cpu_to_le16(chan->dcid);
3588 rsp->result = cpu_to_le16(result);
3589 rsp->flags = cpu_to_le16(0);
3590
3591 return ptr - data;
3592 }
3593
3594 static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len,
3595 void *data, size_t size, u16 *result)
3596 {
3597 struct l2cap_conf_req *req = data;
3598 void *ptr = req->data;
3599 void *endptr = data + size;
3600 int type, olen;
3601 unsigned long val;
3602 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
3603 struct l2cap_conf_efs efs;
3604
3605 BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data);
3606
3607 while (len >= L2CAP_CONF_OPT_SIZE) {
3608 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
3609 if (len < 0)
3610 break;
3611
3612 switch (type) {
3613 case L2CAP_CONF_MTU:
3614 if (olen != 2)
3615 break;
3616 if (val < L2CAP_DEFAULT_MIN_MTU) {
3617 *result = L2CAP_CONF_UNACCEPT;
3618 chan->imtu = L2CAP_DEFAULT_MIN_MTU;
3619 } else
3620 chan->imtu = val;
3621 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu,
3622 endptr - ptr);
3623 break;
3624
3625 case L2CAP_CONF_FLUSH_TO:
3626 if (olen != 2)
3627 break;
3628 chan->flush_to = val;
3629 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, 2,
3630 chan->flush_to, endptr - ptr);
3631 break;
3632
3633 case L2CAP_CONF_RFC:
3634 if (olen != sizeof(rfc))
3635 break;
3636 memcpy(&rfc, (void *)val, olen);
3637 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state) &&
3638 rfc.mode != chan->mode)
3639 return -ECONNREFUSED;
3640 chan->fcs = 0;
3641 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3642 (unsigned long) &rfc, endptr - ptr);
3643 break;
3644
3645 case L2CAP_CONF_EWS:
3646 if (olen != 2)
3647 break;
3648 chan->ack_win = min_t(u16, val, chan->ack_win);
3649 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3650 chan->tx_win, endptr - ptr);
3651 break;
3652
3653 case L2CAP_CONF_EFS:
3654 if (olen != sizeof(efs))
3655 break;
3656 memcpy(&efs, (void *)val, olen);
3657 if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
3658 efs.stype != L2CAP_SERV_NOTRAFIC &&
3659 efs.stype != chan->local_stype)
3660 return -ECONNREFUSED;
3661 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs),
3662 (unsigned long) &efs, endptr - ptr);
3663 break;
3664
3665 case L2CAP_CONF_FCS:
3666 if (olen != 1)
3667 break;
3668 if (*result == L2CAP_CONF_PENDING)
3669 if (val == L2CAP_FCS_NONE)
3670 set_bit(CONF_RECV_NO_FCS,
3671 &chan->conf_state);
3672 break;
3673 }
3674 }
3675
3676 if (chan->mode == L2CAP_MODE_BASIC && chan->mode != rfc.mode)
3677 return -ECONNREFUSED;
3678
3679 chan->mode = rfc.mode;
3680
3681 if (*result == L2CAP_CONF_SUCCESS || *result == L2CAP_CONF_PENDING) {
3682 switch (rfc.mode) {
3683 case L2CAP_MODE_ERTM:
3684 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
3685 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
3686 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3687 if (!test_bit(FLAG_EXT_CTRL, &chan->flags))
3688 chan->ack_win = min_t(u16, chan->ack_win,
3689 rfc.txwin_size);
3690
3691 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
3692 chan->local_msdu = le16_to_cpu(efs.msdu);
3693 chan->local_sdu_itime =
3694 le32_to_cpu(efs.sdu_itime);
3695 chan->local_acc_lat = le32_to_cpu(efs.acc_lat);
3696 chan->local_flush_to =
3697 le32_to_cpu(efs.flush_to);
3698 }
3699 break;
3700
3701 case L2CAP_MODE_STREAMING:
3702 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3703 }
3704 }
3705
3706 req->dcid = cpu_to_le16(chan->dcid);
3707 req->flags = cpu_to_le16(0);
3708
3709 return ptr - data;
3710 }
3711
3712 static int l2cap_build_conf_rsp(struct l2cap_chan *chan, void *data,
3713 u16 result, u16 flags)
3714 {
3715 struct l2cap_conf_rsp *rsp = data;
3716 void *ptr = rsp->data;
3717
3718 BT_DBG("chan %p", chan);
3719
3720 rsp->scid = cpu_to_le16(chan->dcid);
3721 rsp->result = cpu_to_le16(result);
3722 rsp->flags = cpu_to_le16(flags);
3723
3724 return ptr - data;
3725 }
3726
3727 void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan)
3728 {
3729 struct l2cap_le_conn_rsp rsp;
3730 struct l2cap_conn *conn = chan->conn;
3731
3732 BT_DBG("chan %p", chan);
3733
3734 rsp.dcid = cpu_to_le16(chan->scid);
3735 rsp.mtu = cpu_to_le16(chan->imtu);
3736 rsp.mps = cpu_to_le16(chan->mps);
3737 rsp.credits = cpu_to_le16(chan->rx_credits);
3738 rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS);
3739
3740 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
3741 &rsp);
3742 }
3743
3744 static void l2cap_ecred_list_defer(struct l2cap_chan *chan, void *data)
3745 {
3746 int *result = data;
3747
3748 if (*result || test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
3749 return;
3750
3751 switch (chan->state) {
3752 case BT_CONNECT2:
3753 /* If channel still pending accept add to result */
3754 (*result)++;
3755 return;
3756 case BT_CONNECTED:
3757 return;
3758 default:
3759 /* If not connected or pending accept it has been refused */
3760 *result = -ECONNREFUSED;
3761 return;
3762 }
3763 }
3764
3765 struct l2cap_ecred_rsp_data {
3766 struct {
3767 struct l2cap_ecred_conn_rsp_hdr rsp;
3768 __le16 scid[L2CAP_ECRED_MAX_CID];
3769 } __packed pdu;
3770 int count;
3771 };
3772
3773 static void l2cap_ecred_rsp_defer(struct l2cap_chan *chan, void *data)
3774 {
3775 struct l2cap_ecred_rsp_data *rsp = data;
3776 struct l2cap_ecred_conn_rsp *rsp_flex =
3777 container_of(&rsp->pdu.rsp, struct l2cap_ecred_conn_rsp, hdr);
3778
3779 if (test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
3780 return;
3781
3782 /* Reset ident so only one response is sent */
3783 chan->ident = 0;
3784
3785 /* Include all channels pending with the same ident */
3786 if (!rsp->pdu.rsp.result)
3787 rsp_flex->dcid[rsp->count++] = cpu_to_le16(chan->scid);
3788 else
3789 l2cap_chan_del(chan, ECONNRESET);
3790 }
3791
3792 void __l2cap_ecred_conn_rsp_defer(struct l2cap_chan *chan)
3793 {
3794 struct l2cap_conn *conn = chan->conn;
3795 struct l2cap_ecred_rsp_data data;
3796 u16 id = chan->ident;
3797 int result = 0;
3798
3799 if (!id)
3800 return;
3801
3802 BT_DBG("chan %p id %d", chan, id);
3803
3804 memset(&data, 0, sizeof(data));
3805
3806 data.pdu.rsp.mtu = cpu_to_le16(chan->imtu);
3807 data.pdu.rsp.mps = cpu_to_le16(chan->mps);
3808 data.pdu.rsp.credits = cpu_to_le16(chan->rx_credits);
3809 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS);
3810
3811 /* Verify that all channels are ready */
3812 __l2cap_chan_list_id(conn, id, l2cap_ecred_list_defer, &result);
3813
3814 if (result > 0)
3815 return;
3816
3817 if (result < 0)
3818 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_AUTHORIZATION);
3819
3820 /* Build response */
3821 __l2cap_chan_list_id(conn, id, l2cap_ecred_rsp_defer, &data);
3822
3823 l2cap_send_cmd(conn, id, L2CAP_ECRED_CONN_RSP,
3824 sizeof(data.pdu.rsp) + (data.count * sizeof(__le16)),
3825 &data.pdu);
3826 }
3827
3828 void __l2cap_connect_rsp_defer(struct l2cap_chan *chan)
3829 {
3830 struct l2cap_conn_rsp rsp;
3831 struct l2cap_conn *conn = chan->conn;
3832 u8 buf[128];
3833 u8 rsp_code;
3834
3835 rsp.scid = cpu_to_le16(chan->dcid);
3836 rsp.dcid = cpu_to_le16(chan->scid);
3837 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
3838 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
3839 rsp_code = L2CAP_CONN_RSP;
3840
3841 BT_DBG("chan %p rsp_code %u", chan, rsp_code);
3842
3843 l2cap_send_cmd(conn, chan->ident, rsp_code, sizeof(rsp), &rsp);
3844
3845 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
3846 return;
3847
3848 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
3849 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
3850 chan->num_conf_req++;
3851 }
3852
3853 static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len)
3854 {
3855 int type, olen;
3856 unsigned long val;
3857 /* Use sane default values in case a misbehaving remote device
3858 * did not send an RFC or extended window size option.
3859 */
3860 u16 txwin_ext = chan->ack_win;
3861 struct l2cap_conf_rfc rfc = {
3862 .mode = chan->mode,
3863 .retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO),
3864 .monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO),
3865 .max_pdu_size = cpu_to_le16(chan->imtu),
3866 .txwin_size = min_t(u16, chan->ack_win, L2CAP_DEFAULT_TX_WINDOW),
3867 };
3868
3869 BT_DBG("chan %p, rsp %p, len %d", chan, rsp, len);
3870
3871 if ((chan->mode != L2CAP_MODE_ERTM) && (chan->mode != L2CAP_MODE_STREAMING))
3872 return;
3873
3874 while (len >= L2CAP_CONF_OPT_SIZE) {
3875 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
3876 if (len < 0)
3877 break;
3878
3879 switch (type) {
3880 case L2CAP_CONF_RFC:
3881 if (olen != sizeof(rfc))
3882 break;
3883 memcpy(&rfc, (void *)val, olen);
3884 break;
3885 case L2CAP_CONF_EWS:
3886 if (olen != 2)
3887 break;
3888 txwin_ext = val;
3889 break;
3890 }
3891 }
3892
3893 switch (rfc.mode) {
3894 case L2CAP_MODE_ERTM:
3895 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
3896 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
3897 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3898 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
3899 chan->ack_win = min_t(u16, chan->ack_win, txwin_ext);
3900 else
3901 chan->ack_win = min_t(u16, chan->ack_win,
3902 rfc.txwin_size);
3903 break;
3904 case L2CAP_MODE_STREAMING:
3905 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3906 }
3907 }
3908
3909 static inline int l2cap_command_rej(struct l2cap_conn *conn,
3910 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
3911 u8 *data)
3912 {
3913 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
3914
3915 if (cmd_len < sizeof(*rej))
3916 return -EPROTO;
3917
3918 if (rej->reason != L2CAP_REJ_NOT_UNDERSTOOD)
3919 return 0;
3920
3921 if ((conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) &&
3922 cmd->ident == conn->info_ident) {
3923 cancel_delayed_work(&conn->info_timer);
3924
3925 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
3926 conn->info_ident = 0;
3927
3928 l2cap_conn_start(conn);
3929 }
3930
3931 return 0;
3932 }
3933
3934 static void l2cap_connect(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd,
3935 u8 *data, u8 rsp_code)
3936 {
3937 struct l2cap_conn_req *req = (struct l2cap_conn_req *) data;
3938 struct l2cap_conn_rsp rsp;
3939 struct l2cap_chan *chan = NULL, *pchan = NULL;
3940 int result, status = L2CAP_CS_NO_INFO;
3941
3942 u16 dcid = 0, scid = __le16_to_cpu(req->scid);
3943 __le16 psm = req->psm;
3944
3945 BT_DBG("psm 0x%2.2x scid 0x%4.4x", __le16_to_cpu(psm), scid);
3946
3947 /* Check if we have socket listening on psm */
3948 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
3949 &conn->hcon->dst, ACL_LINK);
3950 if (!pchan) {
3951 result = L2CAP_CR_BAD_PSM;
3952 goto response;
3953 }
3954
3955 mutex_lock(&conn->chan_lock);
3956 l2cap_chan_lock(pchan);
3957
3958 /* Check if the ACL is secure enough (if not SDP) */
3959 if (psm != cpu_to_le16(L2CAP_PSM_SDP) &&
3960 !hci_conn_check_link_mode(conn->hcon)) {
3961 conn->disc_reason = HCI_ERROR_AUTH_FAILURE;
3962 result = L2CAP_CR_SEC_BLOCK;
3963 goto response;
3964 }
3965
3966 result = L2CAP_CR_NO_MEM;
3967
3968 /* Check for valid dynamic CID range (as per Erratum 3253) */
3969 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) {
3970 result = L2CAP_CR_INVALID_SCID;
3971 goto response;
3972 }
3973
3974 /* Check if we already have channel with that dcid */
3975 if (__l2cap_get_chan_by_dcid(conn, scid)) {
3976 result = L2CAP_CR_SCID_IN_USE;
3977 goto response;
3978 }
3979
3980 chan = pchan->ops->new_connection(pchan);
3981 if (!chan)
3982 goto response;
3983
3984 /* For certain devices (ex: HID mouse), support for authentication,
3985 * pairing and bonding is optional. For such devices, inorder to avoid
3986 * the ACL alive for too long after L2CAP disconnection, reset the ACL
3987 * disc_timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect.
3988 */
3989 conn->hcon->disc_timeout = HCI_DISCONN_TIMEOUT;
3990
3991 bacpy(&chan->src, &conn->hcon->src);
3992 bacpy(&chan->dst, &conn->hcon->dst);
3993 chan->src_type = bdaddr_src_type(conn->hcon);
3994 chan->dst_type = bdaddr_dst_type(conn->hcon);
3995 chan->psm = psm;
3996 chan->dcid = scid;
3997
3998 __l2cap_chan_add(conn, chan);
3999
4000 dcid = chan->scid;
4001
4002 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
4003
4004 chan->ident = cmd->ident;
4005
4006 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) {
4007 if (l2cap_chan_check_security(chan, false)) {
4008 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
4009 l2cap_state_change(chan, BT_CONNECT2);
4010 result = L2CAP_CR_PEND;
4011 status = L2CAP_CS_AUTHOR_PEND;
4012 chan->ops->defer(chan);
4013 } else {
4014 l2cap_state_change(chan, BT_CONNECT2);
4015 result = L2CAP_CR_PEND;
4016 status = L2CAP_CS_NO_INFO;
4017 }
4018 } else {
4019 l2cap_state_change(chan, BT_CONNECT2);
4020 result = L2CAP_CR_PEND;
4021 status = L2CAP_CS_AUTHEN_PEND;
4022 }
4023 } else {
4024 l2cap_state_change(chan, BT_CONNECT2);
4025 result = L2CAP_CR_PEND;
4026 status = L2CAP_CS_NO_INFO;
4027 }
4028
4029 response:
4030 rsp.scid = cpu_to_le16(scid);
4031 rsp.dcid = cpu_to_le16(dcid);
4032 rsp.result = cpu_to_le16(result);
4033 rsp.status = cpu_to_le16(status);
4034 l2cap_send_cmd(conn, cmd->ident, rsp_code, sizeof(rsp), &rsp);
4035
4036 if (!pchan)
4037 return;
4038
4039 if (result == L2CAP_CR_PEND && status == L2CAP_CS_NO_INFO) {
4040 struct l2cap_info_req info;
4041 info.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
4042
4043 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
4044 conn->info_ident = l2cap_get_ident(conn);
4045
4046 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
4047
4048 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
4049 sizeof(info), &info);
4050 }
4051
4052 if (chan && !test_bit(CONF_REQ_SENT, &chan->conf_state) &&
4053 result == L2CAP_CR_SUCCESS) {
4054 u8 buf[128];
4055 set_bit(CONF_REQ_SENT, &chan->conf_state);
4056 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4057 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4058 chan->num_conf_req++;
4059 }
4060
4061 l2cap_chan_unlock(pchan);
4062 mutex_unlock(&conn->chan_lock);
4063 l2cap_chan_put(pchan);
4064 }
4065
4066 static int l2cap_connect_req(struct l2cap_conn *conn,
4067 struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
4068 {
4069 struct hci_dev *hdev = conn->hcon->hdev;
4070 struct hci_conn *hcon = conn->hcon;
4071
4072 if (cmd_len < sizeof(struct l2cap_conn_req))
4073 return -EPROTO;
4074
4075 hci_dev_lock(hdev);
4076 if (hci_dev_test_flag(hdev, HCI_MGMT))
4077 mgmt_device_connected(hdev, hcon, NULL, 0);
4078 hci_dev_unlock(hdev);
4079
4080 l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP);
4081 return 0;
4082 }
4083
4084 static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
4085 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4086 u8 *data)
4087 {
4088 struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data;
4089 u16 scid, dcid, result, status;
4090 struct l2cap_chan *chan;
4091 u8 req[128];
4092 int err;
4093
4094 if (cmd_len < sizeof(*rsp))
4095 return -EPROTO;
4096
4097 scid = __le16_to_cpu(rsp->scid);
4098 dcid = __le16_to_cpu(rsp->dcid);
4099 result = __le16_to_cpu(rsp->result);
4100 status = __le16_to_cpu(rsp->status);
4101
4102 if (result == L2CAP_CR_SUCCESS && (dcid < L2CAP_CID_DYN_START ||
4103 dcid > L2CAP_CID_DYN_END))
4104 return -EPROTO;
4105
4106 BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x",
4107 dcid, scid, result, status);
4108
4109 mutex_lock(&conn->chan_lock);
4110
4111 if (scid) {
4112 chan = __l2cap_get_chan_by_scid(conn, scid);
4113 if (!chan) {
4114 err = -EBADSLT;
4115 goto unlock;
4116 }
4117 } else {
4118 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
4119 if (!chan) {
4120 err = -EBADSLT;
4121 goto unlock;
4122 }
4123 }
4124
4125 chan = l2cap_chan_hold_unless_zero(chan);
4126 if (!chan) {
4127 err = -EBADSLT;
4128 goto unlock;
4129 }
4130
4131 err = 0;
4132
4133 l2cap_chan_lock(chan);
4134
4135 switch (result) {
4136 case L2CAP_CR_SUCCESS:
4137 if (__l2cap_get_chan_by_dcid(conn, dcid)) {
4138 err = -EBADSLT;
4139 break;
4140 }
4141
4142 l2cap_state_change(chan, BT_CONFIG);
4143 chan->ident = 0;
4144 chan->dcid = dcid;
4145 clear_bit(CONF_CONNECT_PEND, &chan->conf_state);
4146
4147 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
4148 break;
4149
4150 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4151 l2cap_build_conf_req(chan, req, sizeof(req)), req);
4152 chan->num_conf_req++;
4153 break;
4154
4155 case L2CAP_CR_PEND:
4156 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
4157 break;
4158
4159 default:
4160 l2cap_chan_del(chan, ECONNREFUSED);
4161 break;
4162 }
4163
4164 l2cap_chan_unlock(chan);
4165 l2cap_chan_put(chan);
4166
4167 unlock:
4168 mutex_unlock(&conn->chan_lock);
4169
4170 return err;
4171 }
4172
4173 static inline void set_default_fcs(struct l2cap_chan *chan)
4174 {
4175 /* FCS is enabled only in ERTM or streaming mode, if one or both
4176 * sides request it.
4177 */
4178 if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING)
4179 chan->fcs = L2CAP_FCS_NONE;
4180 else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state))
4181 chan->fcs = L2CAP_FCS_CRC16;
4182 }
4183
4184 static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data,
4185 u8 ident, u16 flags)
4186 {
4187 struct l2cap_conn *conn = chan->conn;
4188
4189 BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident,
4190 flags);
4191
4192 clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
4193 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
4194
4195 l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP,
4196 l2cap_build_conf_rsp(chan, data,
4197 L2CAP_CONF_SUCCESS, flags), data);
4198 }
4199
4200 static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident,
4201 u16 scid, u16 dcid)
4202 {
4203 struct l2cap_cmd_rej_cid rej;
4204
4205 rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID);
4206 rej.scid = __cpu_to_le16(scid);
4207 rej.dcid = __cpu_to_le16(dcid);
4208
4209 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
4210 }
4211
4212 static inline int l2cap_config_req(struct l2cap_conn *conn,
4213 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4214 u8 *data)
4215 {
4216 struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
4217 u16 dcid, flags;
4218 u8 rsp[64];
4219 struct l2cap_chan *chan;
4220 int len, err = 0;
4221
4222 if (cmd_len < sizeof(*req))
4223 return -EPROTO;
4224
4225 dcid = __le16_to_cpu(req->dcid);
4226 flags = __le16_to_cpu(req->flags);
4227
4228 BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags);
4229
4230 chan = l2cap_get_chan_by_scid(conn, dcid);
4231 if (!chan) {
4232 cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0);
4233 return 0;
4234 }
4235
4236 if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2 &&
4237 chan->state != BT_CONNECTED) {
4238 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
4239 chan->dcid);
4240 goto unlock;
4241 }
4242
4243 /* Reject if config buffer is too small. */
4244 len = cmd_len - sizeof(*req);
4245 if (chan->conf_len + len > sizeof(chan->conf_req)) {
4246 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4247 l2cap_build_conf_rsp(chan, rsp,
4248 L2CAP_CONF_REJECT, flags), rsp);
4249 goto unlock;
4250 }
4251
4252 /* Store config. */
4253 memcpy(chan->conf_req + chan->conf_len, req->data, len);
4254 chan->conf_len += len;
4255
4256 if (flags & L2CAP_CONF_FLAG_CONTINUATION) {
4257 /* Incomplete config. Send empty response. */
4258 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4259 l2cap_build_conf_rsp(chan, rsp,
4260 L2CAP_CONF_SUCCESS, flags), rsp);
4261 goto unlock;
4262 }
4263
4264 /* Complete config. */
4265 len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp));
4266 if (len < 0) {
4267 l2cap_send_disconn_req(chan, ECONNRESET);
4268 goto unlock;
4269 }
4270
4271 chan->ident = cmd->ident;
4272 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp);
4273 if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP)
4274 chan->num_conf_rsp++;
4275
4276 /* Reset config buffer. */
4277 chan->conf_len = 0;
4278
4279 if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state))
4280 goto unlock;
4281
4282 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
4283 set_default_fcs(chan);
4284
4285 if (chan->mode == L2CAP_MODE_ERTM ||
4286 chan->mode == L2CAP_MODE_STREAMING)
4287 err = l2cap_ertm_init(chan);
4288
4289 if (err < 0)
4290 l2cap_send_disconn_req(chan, -err);
4291 else
4292 l2cap_chan_ready(chan);
4293
4294 goto unlock;
4295 }
4296
4297 if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) {
4298 u8 buf[64];
4299 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4300 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4301 chan->num_conf_req++;
4302 }
4303
4304 /* Got Conf Rsp PENDING from remote side and assume we sent
4305 Conf Rsp PENDING in the code above */
4306 if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) &&
4307 test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4308
4309 /* check compatibility */
4310
4311 /* Send rsp for BR/EDR channel */
4312 l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags);
4313 }
4314
4315 unlock:
4316 l2cap_chan_unlock(chan);
4317 l2cap_chan_put(chan);
4318 return err;
4319 }
4320
4321 static inline int l2cap_config_rsp(struct l2cap_conn *conn,
4322 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4323 u8 *data)
4324 {
4325 struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data;
4326 u16 scid, flags, result;
4327 struct l2cap_chan *chan;
4328 int len = cmd_len - sizeof(*rsp);
4329 int err = 0;
4330
4331 if (cmd_len < sizeof(*rsp))
4332 return -EPROTO;
4333
4334 scid = __le16_to_cpu(rsp->scid);
4335 flags = __le16_to_cpu(rsp->flags);
4336 result = __le16_to_cpu(rsp->result);
4337
4338 BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags,
4339 result, len);
4340
4341 chan = l2cap_get_chan_by_scid(conn, scid);
4342 if (!chan)
4343 return 0;
4344
4345 switch (result) {
4346 case L2CAP_CONF_SUCCESS:
4347 l2cap_conf_rfc_get(chan, rsp->data, len);
4348 clear_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4349 break;
4350
4351 case L2CAP_CONF_PENDING:
4352 set_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4353
4354 if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4355 char buf[64];
4356
4357 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4358 buf, sizeof(buf), &result);
4359 if (len < 0) {
4360 l2cap_send_disconn_req(chan, ECONNRESET);
4361 goto done;
4362 }
4363
4364 l2cap_send_efs_conf_rsp(chan, buf, cmd->ident, 0);
4365 }
4366 goto done;
4367
4368 case L2CAP_CONF_UNKNOWN:
4369 case L2CAP_CONF_UNACCEPT:
4370 if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) {
4371 char req[64];
4372
4373 if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) {
4374 l2cap_send_disconn_req(chan, ECONNRESET);
4375 goto done;
4376 }
4377
4378 /* throw out any old stored conf requests */
4379 result = L2CAP_CONF_SUCCESS;
4380 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4381 req, sizeof(req), &result);
4382 if (len < 0) {
4383 l2cap_send_disconn_req(chan, ECONNRESET);
4384 goto done;
4385 }
4386
4387 l2cap_send_cmd(conn, l2cap_get_ident(conn),
4388 L2CAP_CONF_REQ, len, req);
4389 chan->num_conf_req++;
4390 if (result != L2CAP_CONF_SUCCESS)
4391 goto done;
4392 break;
4393 }
4394 fallthrough;
4395
4396 default:
4397 l2cap_chan_set_err(chan, ECONNRESET);
4398
4399 __set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT);
4400 l2cap_send_disconn_req(chan, ECONNRESET);
4401 goto done;
4402 }
4403
4404 if (flags & L2CAP_CONF_FLAG_CONTINUATION)
4405 goto done;
4406
4407 set_bit(CONF_INPUT_DONE, &chan->conf_state);
4408
4409 if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) {
4410 set_default_fcs(chan);
4411
4412 if (chan->mode == L2CAP_MODE_ERTM ||
4413 chan->mode == L2CAP_MODE_STREAMING)
4414 err = l2cap_ertm_init(chan);
4415
4416 if (err < 0)
4417 l2cap_send_disconn_req(chan, -err);
4418 else
4419 l2cap_chan_ready(chan);
4420 }
4421
4422 done:
4423 l2cap_chan_unlock(chan);
4424 l2cap_chan_put(chan);
4425 return err;
4426 }
4427
4428 static inline int l2cap_disconnect_req(struct l2cap_conn *conn,
4429 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4430 u8 *data)
4431 {
4432 struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data;
4433 struct l2cap_disconn_rsp rsp;
4434 u16 dcid, scid;
4435 struct l2cap_chan *chan;
4436
4437 if (cmd_len != sizeof(*req))
4438 return -EPROTO;
4439
4440 scid = __le16_to_cpu(req->scid);
4441 dcid = __le16_to_cpu(req->dcid);
4442
4443 BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
4444
4445 chan = l2cap_get_chan_by_scid(conn, dcid);
4446 if (!chan) {
4447 cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid);
4448 return 0;
4449 }
4450
4451 rsp.dcid = cpu_to_le16(chan->scid);
4452 rsp.scid = cpu_to_le16(chan->dcid);
4453 l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
4454
4455 chan->ops->set_shutdown(chan);
4456
4457 l2cap_chan_unlock(chan);
4458 mutex_lock(&conn->chan_lock);
4459 l2cap_chan_lock(chan);
4460 l2cap_chan_del(chan, ECONNRESET);
4461 mutex_unlock(&conn->chan_lock);
4462
4463 chan->ops->close(chan);
4464
4465 l2cap_chan_unlock(chan);
4466 l2cap_chan_put(chan);
4467
4468 return 0;
4469 }
4470
4471 static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,
4472 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4473 u8 *data)
4474 {
4475 struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data;
4476 u16 dcid, scid;
4477 struct l2cap_chan *chan;
4478
4479 if (cmd_len != sizeof(*rsp))
4480 return -EPROTO;
4481
4482 scid = __le16_to_cpu(rsp->scid);
4483 dcid = __le16_to_cpu(rsp->dcid);
4484
4485 BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
4486
4487 chan = l2cap_get_chan_by_scid(conn, scid);
4488 if (!chan) {
4489 return 0;
4490 }
4491
4492 if (chan->state != BT_DISCONN) {
4493 l2cap_chan_unlock(chan);
4494 l2cap_chan_put(chan);
4495 return 0;
4496 }
4497
4498 l2cap_chan_unlock(chan);
4499 mutex_lock(&conn->chan_lock);
4500 l2cap_chan_lock(chan);
4501 l2cap_chan_del(chan, 0);
4502 mutex_unlock(&conn->chan_lock);
4503
4504 chan->ops->close(chan);
4505
4506 l2cap_chan_unlock(chan);
4507 l2cap_chan_put(chan);
4508
4509 return 0;
4510 }
4511
4512 static inline int l2cap_information_req(struct l2cap_conn *conn,
4513 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4514 u8 *data)
4515 {
4516 struct l2cap_info_req *req = (struct l2cap_info_req *) data;
4517 u16 type;
4518
4519 if (cmd_len != sizeof(*req))
4520 return -EPROTO;
4521
4522 type = __le16_to_cpu(req->type);
4523
4524 BT_DBG("type 0x%4.4x", type);
4525
4526 if (type == L2CAP_IT_FEAT_MASK) {
4527 u8 buf[8];
4528 u32 feat_mask = l2cap_feat_mask;
4529 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4530 rsp->type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
4531 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4532 if (!disable_ertm)
4533 feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING
4534 | L2CAP_FEAT_FCS;
4535
4536 put_unaligned_le32(feat_mask, rsp->data);
4537 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4538 buf);
4539 } else if (type == L2CAP_IT_FIXED_CHAN) {
4540 u8 buf[12];
4541 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4542
4543 rsp->type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4544 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4545 rsp->data[0] = conn->local_fixed_chan;
4546 memset(rsp->data + 1, 0, 7);
4547 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4548 buf);
4549 } else {
4550 struct l2cap_info_rsp rsp;
4551 rsp.type = cpu_to_le16(type);
4552 rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP);
4553 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp),
4554 &rsp);
4555 }
4556
4557 return 0;
4558 }
4559
4560 static inline int l2cap_information_rsp(struct l2cap_conn *conn,
4561 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4562 u8 *data)
4563 {
4564 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data;
4565 u16 type, result;
4566
4567 if (cmd_len < sizeof(*rsp))
4568 return -EPROTO;
4569
4570 type = __le16_to_cpu(rsp->type);
4571 result = __le16_to_cpu(rsp->result);
4572
4573 BT_DBG("type 0x%4.4x result 0x%2.2x", type, result);
4574
4575 /* L2CAP Info req/rsp are unbound to channels, add extra checks */
4576 if (cmd->ident != conn->info_ident ||
4577 conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
4578 return 0;
4579
4580 cancel_delayed_work(&conn->info_timer);
4581
4582 if (result != L2CAP_IR_SUCCESS) {
4583 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4584 conn->info_ident = 0;
4585
4586 l2cap_conn_start(conn);
4587
4588 return 0;
4589 }
4590
4591 switch (type) {
4592 case L2CAP_IT_FEAT_MASK:
4593 conn->feat_mask = get_unaligned_le32(rsp->data);
4594
4595 if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) {
4596 struct l2cap_info_req req;
4597 req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4598
4599 conn->info_ident = l2cap_get_ident(conn);
4600
4601 l2cap_send_cmd(conn, conn->info_ident,
4602 L2CAP_INFO_REQ, sizeof(req), &req);
4603 } else {
4604 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4605 conn->info_ident = 0;
4606
4607 l2cap_conn_start(conn);
4608 }
4609 break;
4610
4611 case L2CAP_IT_FIXED_CHAN:
4612 conn->remote_fixed_chan = rsp->data[0];
4613 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4614 conn->info_ident = 0;
4615
4616 l2cap_conn_start(conn);
4617 break;
4618 }
4619
4620 return 0;
4621 }
4622
4623 static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
4624 struct l2cap_cmd_hdr *cmd,
4625 u16 cmd_len, u8 *data)
4626 {
4627 struct hci_conn *hcon = conn->hcon;
4628 struct l2cap_conn_param_update_req *req;
4629 struct l2cap_conn_param_update_rsp rsp;
4630 u16 min, max, latency, to_multiplier;
4631 int err;
4632
4633 if (hcon->role != HCI_ROLE_MASTER)
4634 return -EINVAL;
4635
4636 if (cmd_len != sizeof(struct l2cap_conn_param_update_req))
4637 return -EPROTO;
4638
4639 req = (struct l2cap_conn_param_update_req *) data;
4640 min = __le16_to_cpu(req->min);
4641 max = __le16_to_cpu(req->max);
4642 latency = __le16_to_cpu(req->latency);
4643 to_multiplier = __le16_to_cpu(req->to_multiplier);
4644
4645 BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x",
4646 min, max, latency, to_multiplier);
4647
4648 memset(&rsp, 0, sizeof(rsp));
4649
4650 if (max > hcon->le_conn_max_interval) {
4651 BT_DBG("requested connection interval exceeds current bounds.");
4652 err = -EINVAL;
4653 } else {
4654 err = hci_check_conn_params(min, max, latency, to_multiplier);
4655 }
4656
4657 if (err)
4658 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
4659 else
4660 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED);
4661
4662 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP,
4663 sizeof(rsp), &rsp);
4664
4665 if (!err) {
4666 u8 store_hint;
4667
4668 store_hint = hci_le_conn_update(hcon, min, max, latency,
4669 to_multiplier);
4670 mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type,
4671 store_hint, min, max, latency,
4672 to_multiplier);
4673
4674 }
4675
4676 return 0;
4677 }
4678
4679 static int l2cap_le_connect_rsp(struct l2cap_conn *conn,
4680 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4681 u8 *data)
4682 {
4683 struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data;
4684 struct hci_conn *hcon = conn->hcon;
4685 u16 dcid, mtu, mps, credits, result;
4686 struct l2cap_chan *chan;
4687 int err, sec_level;
4688
4689 if (cmd_len < sizeof(*rsp))
4690 return -EPROTO;
4691
4692 dcid = __le16_to_cpu(rsp->dcid);
4693 mtu = __le16_to_cpu(rsp->mtu);
4694 mps = __le16_to_cpu(rsp->mps);
4695 credits = __le16_to_cpu(rsp->credits);
4696 result = __le16_to_cpu(rsp->result);
4697
4698 if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 ||
4699 dcid < L2CAP_CID_DYN_START ||
4700 dcid > L2CAP_CID_LE_DYN_END))
4701 return -EPROTO;
4702
4703 BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x",
4704 dcid, mtu, mps, credits, result);
4705
4706 mutex_lock(&conn->chan_lock);
4707
4708 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
4709 if (!chan) {
4710 err = -EBADSLT;
4711 goto unlock;
4712 }
4713
4714 err = 0;
4715
4716 l2cap_chan_lock(chan);
4717
4718 switch (result) {
4719 case L2CAP_CR_LE_SUCCESS:
4720 if (__l2cap_get_chan_by_dcid(conn, dcid)) {
4721 err = -EBADSLT;
4722 break;
4723 }
4724
4725 chan->ident = 0;
4726 chan->dcid = dcid;
4727 chan->omtu = mtu;
4728 chan->remote_mps = mps;
4729 chan->tx_credits = credits;
4730 l2cap_chan_ready(chan);
4731 break;
4732
4733 case L2CAP_CR_LE_AUTHENTICATION:
4734 case L2CAP_CR_LE_ENCRYPTION:
4735 /* If we already have MITM protection we can't do
4736 * anything.
4737 */
4738 if (hcon->sec_level > BT_SECURITY_MEDIUM) {
4739 l2cap_chan_del(chan, ECONNREFUSED);
4740 break;
4741 }
4742
4743 sec_level = hcon->sec_level + 1;
4744 if (chan->sec_level < sec_level)
4745 chan->sec_level = sec_level;
4746
4747 /* We'll need to send a new Connect Request */
4748 clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags);
4749
4750 smp_conn_security(hcon, chan->sec_level);
4751 break;
4752
4753 default:
4754 l2cap_chan_del(chan, ECONNREFUSED);
4755 break;
4756 }
4757
4758 l2cap_chan_unlock(chan);
4759
4760 unlock:
4761 mutex_unlock(&conn->chan_lock);
4762
4763 return err;
4764 }
4765
4766 static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
4767 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4768 u8 *data)
4769 {
4770 int err = 0;
4771
4772 switch (cmd->code) {
4773 case L2CAP_COMMAND_REJ:
4774 l2cap_command_rej(conn, cmd, cmd_len, data);
4775 break;
4776
4777 case L2CAP_CONN_REQ:
4778 err = l2cap_connect_req(conn, cmd, cmd_len, data);
4779 break;
4780
4781 case L2CAP_CONN_RSP:
4782 l2cap_connect_create_rsp(conn, cmd, cmd_len, data);
4783 break;
4784
4785 case L2CAP_CONF_REQ:
4786 err = l2cap_config_req(conn, cmd, cmd_len, data);
4787 break;
4788
4789 case L2CAP_CONF_RSP:
4790 l2cap_config_rsp(conn, cmd, cmd_len, data);
4791 break;
4792
4793 case L2CAP_DISCONN_REQ:
4794 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
4795 break;
4796
4797 case L2CAP_DISCONN_RSP:
4798 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
4799 break;
4800
4801 case L2CAP_ECHO_REQ:
4802 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data);
4803 break;
4804
4805 case L2CAP_ECHO_RSP:
4806 break;
4807
4808 case L2CAP_INFO_REQ:
4809 err = l2cap_information_req(conn, cmd, cmd_len, data);
4810 break;
4811
4812 case L2CAP_INFO_RSP:
4813 l2cap_information_rsp(conn, cmd, cmd_len, data);
4814 break;
4815
4816 default:
4817 BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code);
4818 err = -EINVAL;
4819 break;
4820 }
4821
4822 return err;
4823 }
4824
4825 static int l2cap_le_connect_req(struct l2cap_conn *conn,
4826 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4827 u8 *data)
4828 {
4829 struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data;
4830 struct l2cap_le_conn_rsp rsp;
4831 struct l2cap_chan *chan, *pchan;
4832 u16 dcid, scid, credits, mtu, mps;
4833 __le16 psm;
4834 u8 result;
4835
4836 if (cmd_len != sizeof(*req))
4837 return -EPROTO;
4838
4839 scid = __le16_to_cpu(req->scid);
4840 mtu = __le16_to_cpu(req->mtu);
4841 mps = __le16_to_cpu(req->mps);
4842 psm = req->psm;
4843 dcid = 0;
4844 credits = 0;
4845
4846 if (mtu < 23 || mps < 23)
4847 return -EPROTO;
4848
4849 BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
4850 scid, mtu, mps);
4851
4852 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
4853 * page 1059:
4854 *
4855 * Valid range: 0x0001-0x00ff
4856 *
4857 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
4858 */
4859 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
4860 result = L2CAP_CR_LE_BAD_PSM;
4861 chan = NULL;
4862 goto response;
4863 }
4864
4865 /* Check if we have socket listening on psm */
4866 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
4867 &conn->hcon->dst, LE_LINK);
4868 if (!pchan) {
4869 result = L2CAP_CR_LE_BAD_PSM;
4870 chan = NULL;
4871 goto response;
4872 }
4873
4874 mutex_lock(&conn->chan_lock);
4875 l2cap_chan_lock(pchan);
4876
4877 if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
4878 SMP_ALLOW_STK)) {
4879 result = L2CAP_CR_LE_AUTHENTICATION;
4880 chan = NULL;
4881 goto response_unlock;
4882 }
4883
4884 /* Check for valid dynamic CID range */
4885 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
4886 result = L2CAP_CR_LE_INVALID_SCID;
4887 chan = NULL;
4888 goto response_unlock;
4889 }
4890
4891 /* Check if we already have channel with that dcid */
4892 if (__l2cap_get_chan_by_dcid(conn, scid)) {
4893 result = L2CAP_CR_LE_SCID_IN_USE;
4894 chan = NULL;
4895 goto response_unlock;
4896 }
4897
4898 chan = pchan->ops->new_connection(pchan);
4899 if (!chan) {
4900 result = L2CAP_CR_LE_NO_MEM;
4901 goto response_unlock;
4902 }
4903
4904 bacpy(&chan->src, &conn->hcon->src);
4905 bacpy(&chan->dst, &conn->hcon->dst);
4906 chan->src_type = bdaddr_src_type(conn->hcon);
4907 chan->dst_type = bdaddr_dst_type(conn->hcon);
4908 chan->psm = psm;
4909 chan->dcid = scid;
4910 chan->omtu = mtu;
4911 chan->remote_mps = mps;
4912
4913 __l2cap_chan_add(conn, chan);
4914
4915 l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits));
4916
4917 dcid = chan->scid;
4918 credits = chan->rx_credits;
4919
4920 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
4921
4922 chan->ident = cmd->ident;
4923
4924 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
4925 l2cap_state_change(chan, BT_CONNECT2);
4926 /* The following result value is actually not defined
4927 * for LE CoC but we use it to let the function know
4928 * that it should bail out after doing its cleanup
4929 * instead of sending a response.
4930 */
4931 result = L2CAP_CR_PEND;
4932 chan->ops->defer(chan);
4933 } else {
4934 l2cap_chan_ready(chan);
4935 result = L2CAP_CR_LE_SUCCESS;
4936 }
4937
4938 response_unlock:
4939 l2cap_chan_unlock(pchan);
4940 mutex_unlock(&conn->chan_lock);
4941 l2cap_chan_put(pchan);
4942
4943 if (result == L2CAP_CR_PEND)
4944 return 0;
4945
4946 response:
4947 if (chan) {
4948 rsp.mtu = cpu_to_le16(chan->imtu);
4949 rsp.mps = cpu_to_le16(chan->mps);
4950 } else {
4951 rsp.mtu = 0;
4952 rsp.mps = 0;
4953 }
4954
4955 rsp.dcid = cpu_to_le16(dcid);
4956 rsp.credits = cpu_to_le16(credits);
4957 rsp.result = cpu_to_le16(result);
4958
4959 l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp);
4960
4961 return 0;
4962 }
4963
4964 static inline int l2cap_le_credits(struct l2cap_conn *conn,
4965 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4966 u8 *data)
4967 {
4968 struct l2cap_le_credits *pkt;
4969 struct l2cap_chan *chan;
4970 u16 cid, credits, max_credits;
4971
4972 if (cmd_len != sizeof(*pkt))
4973 return -EPROTO;
4974
4975 pkt = (struct l2cap_le_credits *) data;
4976 cid = __le16_to_cpu(pkt->cid);
4977 credits = __le16_to_cpu(pkt->credits);
4978
4979 BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits);
4980
4981 chan = l2cap_get_chan_by_dcid(conn, cid);
4982 if (!chan)
4983 return -EBADSLT;
4984
4985 max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits;
4986 if (credits > max_credits) {
4987 BT_ERR("LE credits overflow");
4988 l2cap_send_disconn_req(chan, ECONNRESET);
4989
4990 /* Return 0 so that we don't trigger an unnecessary
4991 * command reject packet.
4992 */
4993 goto unlock;
4994 }
4995
4996 chan->tx_credits += credits;
4997
4998 /* Resume sending */
4999 l2cap_le_flowctl_send(chan);
5000
5001 if (chan->tx_credits)
5002 chan->ops->resume(chan);
5003
5004 unlock:
5005 l2cap_chan_unlock(chan);
5006 l2cap_chan_put(chan);
5007
5008 return 0;
5009 }
5010
5011 static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
5012 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5013 u8 *data)
5014 {
5015 struct l2cap_ecred_conn_req *req = (void *) data;
5016 DEFINE_RAW_FLEX(struct l2cap_ecred_conn_rsp, pdu, dcid, L2CAP_ECRED_MAX_CID);
5017 struct l2cap_chan *chan, *pchan;
5018 u16 mtu, mps;
5019 __le16 psm;
5020 u8 result, len = 0;
5021 int i, num_scid;
5022 bool defer = false;
5023
5024 if (!enable_ecred)
5025 return -EINVAL;
5026
5027 if (cmd_len < sizeof(*req) || (cmd_len - sizeof(*req)) % sizeof(u16)) {
5028 result = L2CAP_CR_LE_INVALID_PARAMS;
5029 goto response;
5030 }
5031
5032 cmd_len -= sizeof(*req);
5033 num_scid = cmd_len / sizeof(u16);
5034
5035 if (num_scid > L2CAP_ECRED_MAX_CID) {
5036 result = L2CAP_CR_LE_INVALID_PARAMS;
5037 goto response;
5038 }
5039
5040 mtu = __le16_to_cpu(req->mtu);
5041 mps = __le16_to_cpu(req->mps);
5042
5043 if (mtu < L2CAP_ECRED_MIN_MTU || mps < L2CAP_ECRED_MIN_MPS) {
5044 result = L2CAP_CR_LE_UNACCEPT_PARAMS;
5045 goto response;
5046 }
5047
5048 psm = req->psm;
5049
5050 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
5051 * page 1059:
5052 *
5053 * Valid range: 0x0001-0x00ff
5054 *
5055 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
5056 */
5057 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
5058 result = L2CAP_CR_LE_BAD_PSM;
5059 goto response;
5060 }
5061
5062 BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps);
5063
5064 memset(pdu, 0, sizeof(*pdu));
5065
5066 /* Check if we have socket listening on psm */
5067 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
5068 &conn->hcon->dst, LE_LINK);
5069 if (!pchan) {
5070 result = L2CAP_CR_LE_BAD_PSM;
5071 goto response;
5072 }
5073
5074 mutex_lock(&conn->chan_lock);
5075 l2cap_chan_lock(pchan);
5076
5077 if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
5078 SMP_ALLOW_STK)) {
5079 result = L2CAP_CR_LE_AUTHENTICATION;
5080 goto unlock;
5081 }
5082
5083 result = L2CAP_CR_LE_SUCCESS;
5084
5085 for (i = 0; i < num_scid; i++) {
5086 u16 scid = __le16_to_cpu(req->scid[i]);
5087
5088 BT_DBG("scid[%d] 0x%4.4x", i, scid);
5089
5090 pdu->dcid[i] = 0x0000;
5091 len += sizeof(*pdu->dcid);
5092
5093 /* Check for valid dynamic CID range */
5094 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
5095 result = L2CAP_CR_LE_INVALID_SCID;
5096 continue;
5097 }
5098
5099 /* Check if we already have channel with that dcid */
5100 if (__l2cap_get_chan_by_dcid(conn, scid)) {
5101 result = L2CAP_CR_LE_SCID_IN_USE;
5102 continue;
5103 }
5104
5105 chan = pchan->ops->new_connection(pchan);
5106 if (!chan) {
5107 result = L2CAP_CR_LE_NO_MEM;
5108 continue;
5109 }
5110
5111 bacpy(&chan->src, &conn->hcon->src);
5112 bacpy(&chan->dst, &conn->hcon->dst);
5113 chan->src_type = bdaddr_src_type(conn->hcon);
5114 chan->dst_type = bdaddr_dst_type(conn->hcon);
5115 chan->psm = psm;
5116 chan->dcid = scid;
5117 chan->omtu = mtu;
5118 chan->remote_mps = mps;
5119
5120 __l2cap_chan_add(conn, chan);
5121
5122 l2cap_ecred_init(chan, __le16_to_cpu(req->credits));
5123
5124 /* Init response */
5125 if (!pdu->credits) {
5126 pdu->mtu = cpu_to_le16(chan->imtu);
5127 pdu->mps = cpu_to_le16(chan->mps);
5128 pdu->credits = cpu_to_le16(chan->rx_credits);
5129 }
5130
5131 pdu->dcid[i] = cpu_to_le16(chan->scid);
5132
5133 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
5134
5135 chan->ident = cmd->ident;
5136 chan->mode = L2CAP_MODE_EXT_FLOWCTL;
5137
5138 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
5139 l2cap_state_change(chan, BT_CONNECT2);
5140 defer = true;
5141 chan->ops->defer(chan);
5142 } else {
5143 l2cap_chan_ready(chan);
5144 }
5145 }
5146
5147 unlock:
5148 l2cap_chan_unlock(pchan);
5149 mutex_unlock(&conn->chan_lock);
5150 l2cap_chan_put(pchan);
5151
5152 response:
5153 pdu->result = cpu_to_le16(result);
5154
5155 if (defer)
5156 return 0;
5157
5158 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_CONN_RSP,
5159 sizeof(*pdu) + len, pdu);
5160
5161 return 0;
5162 }
5163
5164 static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn,
5165 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5166 u8 *data)
5167 {
5168 struct l2cap_ecred_conn_rsp *rsp = (void *) data;
5169 struct hci_conn *hcon = conn->hcon;
5170 u16 mtu, mps, credits, result;
5171 struct l2cap_chan *chan, *tmp;
5172 int err = 0, sec_level;
5173 int i = 0;
5174
5175 if (cmd_len < sizeof(*rsp))
5176 return -EPROTO;
5177
5178 mtu = __le16_to_cpu(rsp->mtu);
5179 mps = __le16_to_cpu(rsp->mps);
5180 credits = __le16_to_cpu(rsp->credits);
5181 result = __le16_to_cpu(rsp->result);
5182
5183 BT_DBG("mtu %u mps %u credits %u result 0x%4.4x", mtu, mps, credits,
5184 result);
5185
5186 mutex_lock(&conn->chan_lock);
5187
5188 cmd_len -= sizeof(*rsp);
5189
5190 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
5191 u16 dcid;
5192
5193 if (chan->ident != cmd->ident ||
5194 chan->mode != L2CAP_MODE_EXT_FLOWCTL ||
5195 chan->state == BT_CONNECTED)
5196 continue;
5197
5198 l2cap_chan_lock(chan);
5199
5200 /* Check that there is a dcid for each pending channel */
5201 if (cmd_len < sizeof(dcid)) {
5202 l2cap_chan_del(chan, ECONNREFUSED);
5203 l2cap_chan_unlock(chan);
5204 continue;
5205 }
5206
5207 dcid = __le16_to_cpu(rsp->dcid[i++]);
5208 cmd_len -= sizeof(u16);
5209
5210 BT_DBG("dcid[%d] 0x%4.4x", i, dcid);
5211
5212 /* Check if dcid is already in use */
5213 if (dcid && __l2cap_get_chan_by_dcid(conn, dcid)) {
5214 /* If a device receives a
5215 * L2CAP_CREDIT_BASED_CONNECTION_RSP packet with an
5216 * already-assigned Destination CID, then both the
5217 * original channel and the new channel shall be
5218 * immediately discarded and not used.
5219 */
5220 l2cap_chan_del(chan, ECONNREFUSED);
5221 l2cap_chan_unlock(chan);
5222 chan = __l2cap_get_chan_by_dcid(conn, dcid);
5223 l2cap_chan_lock(chan);
5224 l2cap_chan_del(chan, ECONNRESET);
5225 l2cap_chan_unlock(chan);
5226 continue;
5227 }
5228
5229 switch (result) {
5230 case L2CAP_CR_LE_AUTHENTICATION:
5231 case L2CAP_CR_LE_ENCRYPTION:
5232 /* If we already have MITM protection we can't do
5233 * anything.
5234 */
5235 if (hcon->sec_level > BT_SECURITY_MEDIUM) {
5236 l2cap_chan_del(chan, ECONNREFUSED);
5237 break;
5238 }
5239
5240 sec_level = hcon->sec_level + 1;
5241 if (chan->sec_level < sec_level)
5242 chan->sec_level = sec_level;
5243
5244 /* We'll need to send a new Connect Request */
5245 clear_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags);
5246
5247 smp_conn_security(hcon, chan->sec_level);
5248 break;
5249
5250 case L2CAP_CR_LE_BAD_PSM:
5251 l2cap_chan_del(chan, ECONNREFUSED);
5252 break;
5253
5254 default:
5255 /* If dcid was not set it means channels was refused */
5256 if (!dcid) {
5257 l2cap_chan_del(chan, ECONNREFUSED);
5258 break;
5259 }
5260
5261 chan->ident = 0;
5262 chan->dcid = dcid;
5263 chan->omtu = mtu;
5264 chan->remote_mps = mps;
5265 chan->tx_credits = credits;
5266 l2cap_chan_ready(chan);
5267 break;
5268 }
5269
5270 l2cap_chan_unlock(chan);
5271 }
5272
5273 mutex_unlock(&conn->chan_lock);
5274
5275 return err;
5276 }
5277
5278 static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn,
5279 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5280 u8 *data)
5281 {
5282 struct l2cap_ecred_reconf_req *req = (void *) data;
5283 struct l2cap_ecred_reconf_rsp rsp;
5284 u16 mtu, mps, result;
5285 struct l2cap_chan *chan;
5286 int i, num_scid;
5287
5288 if (!enable_ecred)
5289 return -EINVAL;
5290
5291 if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) {
5292 result = L2CAP_CR_LE_INVALID_PARAMS;
5293 goto respond;
5294 }
5295
5296 mtu = __le16_to_cpu(req->mtu);
5297 mps = __le16_to_cpu(req->mps);
5298
5299 BT_DBG("mtu %u mps %u", mtu, mps);
5300
5301 if (mtu < L2CAP_ECRED_MIN_MTU) {
5302 result = L2CAP_RECONF_INVALID_MTU;
5303 goto respond;
5304 }
5305
5306 if (mps < L2CAP_ECRED_MIN_MPS) {
5307 result = L2CAP_RECONF_INVALID_MPS;
5308 goto respond;
5309 }
5310
5311 cmd_len -= sizeof(*req);
5312 num_scid = cmd_len / sizeof(u16);
5313 result = L2CAP_RECONF_SUCCESS;
5314
5315 for (i = 0; i < num_scid; i++) {
5316 u16 scid;
5317
5318 scid = __le16_to_cpu(req->scid[i]);
5319 if (!scid)
5320 return -EPROTO;
5321
5322 chan = __l2cap_get_chan_by_dcid(conn, scid);
5323 if (!chan)
5324 continue;
5325
5326 /* If the MTU value is decreased for any of the included
5327 * channels, then the receiver shall disconnect all
5328 * included channels.
5329 */
5330 if (chan->omtu > mtu) {
5331 BT_ERR("chan %p decreased MTU %u -> %u", chan,
5332 chan->omtu, mtu);
5333 result = L2CAP_RECONF_INVALID_MTU;
5334 }
5335
5336 chan->omtu = mtu;
5337 chan->remote_mps = mps;
5338 }
5339
5340 respond:
5341 rsp.result = cpu_to_le16(result);
5342
5343 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_RECONF_RSP, sizeof(rsp),
5344 &rsp);
5345
5346 return 0;
5347 }
5348
5349 static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn,
5350 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5351 u8 *data)
5352 {
5353 struct l2cap_chan *chan, *tmp;
5354 struct l2cap_ecred_conn_rsp *rsp = (void *) data;
5355 u16 result;
5356
5357 if (cmd_len < sizeof(*rsp))
5358 return -EPROTO;
5359
5360 result = __le16_to_cpu(rsp->result);
5361
5362 BT_DBG("result 0x%4.4x", rsp->result);
5363
5364 if (!result)
5365 return 0;
5366
5367 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
5368 if (chan->ident != cmd->ident)
5369 continue;
5370
5371 l2cap_chan_del(chan, ECONNRESET);
5372 }
5373
5374 return 0;
5375 }
5376
5377 static inline int l2cap_le_command_rej(struct l2cap_conn *conn,
5378 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5379 u8 *data)
5380 {
5381 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
5382 struct l2cap_chan *chan;
5383
5384 if (cmd_len < sizeof(*rej))
5385 return -EPROTO;
5386
5387 mutex_lock(&conn->chan_lock);
5388
5389 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
5390 if (!chan)
5391 goto done;
5392
5393 chan = l2cap_chan_hold_unless_zero(chan);
5394 if (!chan)
5395 goto done;
5396
5397 l2cap_chan_lock(chan);
5398 l2cap_chan_del(chan, ECONNREFUSED);
5399 l2cap_chan_unlock(chan);
5400 l2cap_chan_put(chan);
5401
5402 done:
5403 mutex_unlock(&conn->chan_lock);
5404 return 0;
5405 }
5406
5407 static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
5408 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5409 u8 *data)
5410 {
5411 int err = 0;
5412
5413 switch (cmd->code) {
5414 case L2CAP_COMMAND_REJ:
5415 l2cap_le_command_rej(conn, cmd, cmd_len, data);
5416 break;
5417
5418 case L2CAP_CONN_PARAM_UPDATE_REQ:
5419 err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data);
5420 break;
5421
5422 case L2CAP_CONN_PARAM_UPDATE_RSP:
5423 break;
5424
5425 case L2CAP_LE_CONN_RSP:
5426 l2cap_le_connect_rsp(conn, cmd, cmd_len, data);
5427 break;
5428
5429 case L2CAP_LE_CONN_REQ:
5430 err = l2cap_le_connect_req(conn, cmd, cmd_len, data);
5431 break;
5432
5433 case L2CAP_LE_CREDITS:
5434 err = l2cap_le_credits(conn, cmd, cmd_len, data);
5435 break;
5436
5437 case L2CAP_ECRED_CONN_REQ:
5438 err = l2cap_ecred_conn_req(conn, cmd, cmd_len, data);
5439 break;
5440
5441 case L2CAP_ECRED_CONN_RSP:
5442 err = l2cap_ecred_conn_rsp(conn, cmd, cmd_len, data);
5443 break;
5444
5445 case L2CAP_ECRED_RECONF_REQ:
5446 err = l2cap_ecred_reconf_req(conn, cmd, cmd_len, data);
5447 break;
5448
5449 case L2CAP_ECRED_RECONF_RSP:
5450 err = l2cap_ecred_reconf_rsp(conn, cmd, cmd_len, data);
5451 break;
5452
5453 case L2CAP_DISCONN_REQ:
5454 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
5455 break;
5456
5457 case L2CAP_DISCONN_RSP:
5458 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
5459 break;
5460
5461 default:
5462 BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code);
5463 err = -EINVAL;
5464 break;
5465 }
5466
5467 return err;
5468 }
5469
5470 static inline void l2cap_le_sig_channel(struct l2cap_conn *conn,
5471 struct sk_buff *skb)
5472 {
5473 struct hci_conn *hcon = conn->hcon;
5474 struct l2cap_cmd_hdr *cmd;
5475 u16 len;
5476 int err;
5477
5478 if (hcon->type != LE_LINK)
5479 goto drop;
5480
5481 if (skb->len < L2CAP_CMD_HDR_SIZE)
5482 goto drop;
5483
5484 cmd = (void *) skb->data;
5485 skb_pull(skb, L2CAP_CMD_HDR_SIZE);
5486
5487 len = le16_to_cpu(cmd->len);
5488
5489 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident);
5490
5491 if (len != skb->len || !cmd->ident) {
5492 BT_DBG("corrupted command");
5493 goto drop;
5494 }
5495
5496 err = l2cap_le_sig_cmd(conn, cmd, len, skb->data);
5497 if (err) {
5498 struct l2cap_cmd_rej_unk rej;
5499
5500 BT_ERR("Wrong link type (%d)", err);
5501
5502 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
5503 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ,
5504 sizeof(rej), &rej);
5505 }
5506
5507 drop:
5508 kfree_skb(skb);
5509 }
5510
5511 static inline void l2cap_sig_send_rej(struct l2cap_conn *conn, u16 ident)
5512 {
5513 struct l2cap_cmd_rej_unk rej;
5514
5515 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
5516 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
5517 }
5518
5519 static inline void l2cap_sig_channel(struct l2cap_conn *conn,
5520 struct sk_buff *skb)
5521 {
5522 struct hci_conn *hcon = conn->hcon;
5523 struct l2cap_cmd_hdr *cmd;
5524 int err;
5525
5526 l2cap_raw_recv(conn, skb);
5527
5528 if (hcon->type != ACL_LINK)
5529 goto drop;
5530
5531 while (skb->len >= L2CAP_CMD_HDR_SIZE) {
5532 u16 len;
5533
5534 cmd = (void *) skb->data;
5535 skb_pull(skb, L2CAP_CMD_HDR_SIZE);
5536
5537 len = le16_to_cpu(cmd->len);
5538
5539 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len,
5540 cmd->ident);
5541
5542 if (len > skb->len || !cmd->ident) {
5543 BT_DBG("corrupted command");
5544 l2cap_sig_send_rej(conn, cmd->ident);
5545 skb_pull(skb, len > skb->len ? skb->len : len);
5546 continue;
5547 }
5548
5549 err = l2cap_bredr_sig_cmd(conn, cmd, len, skb->data);
5550 if (err) {
5551 BT_ERR("Wrong link type (%d)", err);
5552 l2cap_sig_send_rej(conn, cmd->ident);
5553 }
5554
5555 skb_pull(skb, len);
5556 }
5557
5558 if (skb->len > 0) {
5559 BT_DBG("corrupted command");
5560 l2cap_sig_send_rej(conn, 0);
5561 }
5562
5563 drop:
5564 kfree_skb(skb);
5565 }
5566
5567 static int l2cap_check_fcs(struct l2cap_chan *chan, struct sk_buff *skb)
5568 {
5569 u16 our_fcs, rcv_fcs;
5570 int hdr_size;
5571
5572 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
5573 hdr_size = L2CAP_EXT_HDR_SIZE;
5574 else
5575 hdr_size = L2CAP_ENH_HDR_SIZE;
5576
5577 if (chan->fcs == L2CAP_FCS_CRC16) {
5578 skb_trim(skb, skb->len - L2CAP_FCS_SIZE);
5579 rcv_fcs = get_unaligned_le16(skb->data + skb->len);
5580 our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size);
5581
5582 if (our_fcs != rcv_fcs)
5583 return -EBADMSG;
5584 }
5585 return 0;
5586 }
5587
5588 static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan)
5589 {
5590 struct l2cap_ctrl control;
5591
5592 BT_DBG("chan %p", chan);
5593
5594 memset(&control, 0, sizeof(control));
5595 control.sframe = 1;
5596 control.final = 1;
5597 control.reqseq = chan->buffer_seq;
5598 set_bit(CONN_SEND_FBIT, &chan->conn_state);
5599
5600 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5601 control.super = L2CAP_SUPER_RNR;
5602 l2cap_send_sframe(chan, &control);
5603 }
5604
5605 if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) &&
5606 chan->unacked_frames > 0)
5607 __set_retrans_timer(chan);
5608
5609 /* Send pending iframes */
5610 l2cap_ertm_send(chan);
5611
5612 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
5613 test_bit(CONN_SEND_FBIT, &chan->conn_state)) {
5614 /* F-bit wasn't sent in an s-frame or i-frame yet, so
5615 * send it now.
5616 */
5617 control.super = L2CAP_SUPER_RR;
5618 l2cap_send_sframe(chan, &control);
5619 }
5620 }
5621
5622 static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag,
5623 struct sk_buff **last_frag)
5624 {
5625 /* skb->len reflects data in skb as well as all fragments
5626 * skb->data_len reflects only data in fragments
5627 */
5628 if (!skb_has_frag_list(skb))
5629 skb_shinfo(skb)->frag_list = new_frag;
5630
5631 new_frag->next = NULL;
5632
5633 (*last_frag)->next = new_frag;
5634 *last_frag = new_frag;
5635
5636 skb->len += new_frag->len;
5637 skb->data_len += new_frag->len;
5638 skb->truesize += new_frag->truesize;
5639 }
5640
5641 static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb,
5642 struct l2cap_ctrl *control)
5643 {
5644 int err = -EINVAL;
5645
5646 switch (control->sar) {
5647 case L2CAP_SAR_UNSEGMENTED:
5648 if (chan->sdu)
5649 break;
5650
5651 err = chan->ops->recv(chan, skb);
5652 break;
5653
5654 case L2CAP_SAR_START:
5655 if (chan->sdu)
5656 break;
5657
5658 if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE))
5659 break;
5660
5661 chan->sdu_len = get_unaligned_le16(skb->data);
5662 skb_pull(skb, L2CAP_SDULEN_SIZE);
5663
5664 if (chan->sdu_len > chan->imtu) {
5665 err = -EMSGSIZE;
5666 break;
5667 }
5668
5669 if (skb->len >= chan->sdu_len)
5670 break;
5671
5672 chan->sdu = skb;
5673 chan->sdu_last_frag = skb;
5674
5675 skb = NULL;
5676 err = 0;
5677 break;
5678
5679 case L2CAP_SAR_CONTINUE:
5680 if (!chan->sdu)
5681 break;
5682
5683 append_skb_frag(chan->sdu, skb,
5684 &chan->sdu_last_frag);
5685 skb = NULL;
5686
5687 if (chan->sdu->len >= chan->sdu_len)
5688 break;
5689
5690 err = 0;
5691 break;
5692
5693 case L2CAP_SAR_END:
5694 if (!chan->sdu)
5695 break;
5696
5697 append_skb_frag(chan->sdu, skb,
5698 &chan->sdu_last_frag);
5699 skb = NULL;
5700
5701 if (chan->sdu->len != chan->sdu_len)
5702 break;
5703
5704 err = chan->ops->recv(chan, chan->sdu);
5705
5706 if (!err) {
5707 /* Reassembly complete */
5708 chan->sdu = NULL;
5709 chan->sdu_last_frag = NULL;
5710 chan->sdu_len = 0;
5711 }
5712 break;
5713 }
5714
5715 if (err) {
5716 kfree_skb(skb);
5717 kfree_skb(chan->sdu);
5718 chan->sdu = NULL;
5719 chan->sdu_last_frag = NULL;
5720 chan->sdu_len = 0;
5721 }
5722
5723 return err;
5724 }
5725
5726 static int l2cap_resegment(struct l2cap_chan *chan)
5727 {
5728 /* Placeholder */
5729 return 0;
5730 }
5731
5732 void l2cap_chan_busy(struct l2cap_chan *chan, int busy)
5733 {
5734 u8 event;
5735
5736 if (chan->mode != L2CAP_MODE_ERTM)
5737 return;
5738
5739 event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR;
5740 l2cap_tx(chan, NULL, NULL, event);
5741 }
5742
5743 static int l2cap_rx_queued_iframes(struct l2cap_chan *chan)
5744 {
5745 int err = 0;
5746 /* Pass sequential frames to l2cap_reassemble_sdu()
5747 * until a gap is encountered.
5748 */
5749
5750 BT_DBG("chan %p", chan);
5751
5752 while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5753 struct sk_buff *skb;
5754 BT_DBG("Searching for skb with txseq %d (queue len %d)",
5755 chan->buffer_seq, skb_queue_len(&chan->srej_q));
5756
5757 skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq);
5758
5759 if (!skb)
5760 break;
5761
5762 skb_unlink(skb, &chan->srej_q);
5763 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
5764 err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap);
5765 if (err)
5766 break;
5767 }
5768
5769 if (skb_queue_empty(&chan->srej_q)) {
5770 chan->rx_state = L2CAP_RX_STATE_RECV;
5771 l2cap_send_ack(chan);
5772 }
5773
5774 return err;
5775 }
5776
5777 static void l2cap_handle_srej(struct l2cap_chan *chan,
5778 struct l2cap_ctrl *control)
5779 {
5780 struct sk_buff *skb;
5781
5782 BT_DBG("chan %p, control %p", chan, control);
5783
5784 if (control->reqseq == chan->next_tx_seq) {
5785 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
5786 l2cap_send_disconn_req(chan, ECONNRESET);
5787 return;
5788 }
5789
5790 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
5791
5792 if (skb == NULL) {
5793 BT_DBG("Seq %d not available for retransmission",
5794 control->reqseq);
5795 return;
5796 }
5797
5798 if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) {
5799 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
5800 l2cap_send_disconn_req(chan, ECONNRESET);
5801 return;
5802 }
5803
5804 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
5805
5806 if (control->poll) {
5807 l2cap_pass_to_tx(chan, control);
5808
5809 set_bit(CONN_SEND_FBIT, &chan->conn_state);
5810 l2cap_retransmit(chan, control);
5811 l2cap_ertm_send(chan);
5812
5813 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
5814 set_bit(CONN_SREJ_ACT, &chan->conn_state);
5815 chan->srej_save_reqseq = control->reqseq;
5816 }
5817 } else {
5818 l2cap_pass_to_tx_fbit(chan, control);
5819
5820 if (control->final) {
5821 if (chan->srej_save_reqseq != control->reqseq ||
5822 !test_and_clear_bit(CONN_SREJ_ACT,
5823 &chan->conn_state))
5824 l2cap_retransmit(chan, control);
5825 } else {
5826 l2cap_retransmit(chan, control);
5827 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
5828 set_bit(CONN_SREJ_ACT, &chan->conn_state);
5829 chan->srej_save_reqseq = control->reqseq;
5830 }
5831 }
5832 }
5833 }
5834
5835 static void l2cap_handle_rej(struct l2cap_chan *chan,
5836 struct l2cap_ctrl *control)
5837 {
5838 struct sk_buff *skb;
5839
5840 BT_DBG("chan %p, control %p", chan, control);
5841
5842 if (control->reqseq == chan->next_tx_seq) {
5843 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
5844 l2cap_send_disconn_req(chan, ECONNRESET);
5845 return;
5846 }
5847
5848 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
5849
5850 if (chan->max_tx && skb &&
5851 bt_cb(skb)->l2cap.retries >= chan->max_tx) {
5852 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
5853 l2cap_send_disconn_req(chan, ECONNRESET);
5854 return;
5855 }
5856
5857 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
5858
5859 l2cap_pass_to_tx(chan, control);
5860
5861 if (control->final) {
5862 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state))
5863 l2cap_retransmit_all(chan, control);
5864 } else {
5865 l2cap_retransmit_all(chan, control);
5866 l2cap_ertm_send(chan);
5867 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F)
5868 set_bit(CONN_REJ_ACT, &chan->conn_state);
5869 }
5870 }
5871
5872 static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq)
5873 {
5874 BT_DBG("chan %p, txseq %d", chan, txseq);
5875
5876 BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq,
5877 chan->expected_tx_seq);
5878
5879 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
5880 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
5881 chan->tx_win) {
5882 /* See notes below regarding "double poll" and
5883 * invalid packets.
5884 */
5885 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
5886 BT_DBG("Invalid/Ignore - after SREJ");
5887 return L2CAP_TXSEQ_INVALID_IGNORE;
5888 } else {
5889 BT_DBG("Invalid - in window after SREJ sent");
5890 return L2CAP_TXSEQ_INVALID;
5891 }
5892 }
5893
5894 if (chan->srej_list.head == txseq) {
5895 BT_DBG("Expected SREJ");
5896 return L2CAP_TXSEQ_EXPECTED_SREJ;
5897 }
5898
5899 if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) {
5900 BT_DBG("Duplicate SREJ - txseq already stored");
5901 return L2CAP_TXSEQ_DUPLICATE_SREJ;
5902 }
5903
5904 if (l2cap_seq_list_contains(&chan->srej_list, txseq)) {
5905 BT_DBG("Unexpected SREJ - not requested");
5906 return L2CAP_TXSEQ_UNEXPECTED_SREJ;
5907 }
5908 }
5909
5910 if (chan->expected_tx_seq == txseq) {
5911 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
5912 chan->tx_win) {
5913 BT_DBG("Invalid - txseq outside tx window");
5914 return L2CAP_TXSEQ_INVALID;
5915 } else {
5916 BT_DBG("Expected");
5917 return L2CAP_TXSEQ_EXPECTED;
5918 }
5919 }
5920
5921 if (__seq_offset(chan, txseq, chan->last_acked_seq) <
5922 __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) {
5923 BT_DBG("Duplicate - expected_tx_seq later than txseq");
5924 return L2CAP_TXSEQ_DUPLICATE;
5925 }
5926
5927 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) {
5928 /* A source of invalid packets is a "double poll" condition,
5929 * where delays cause us to send multiple poll packets. If
5930 * the remote stack receives and processes both polls,
5931 * sequence numbers can wrap around in such a way that a
5932 * resent frame has a sequence number that looks like new data
5933 * with a sequence gap. This would trigger an erroneous SREJ
5934 * request.
5935 *
5936 * Fortunately, this is impossible with a tx window that's
5937 * less than half of the maximum sequence number, which allows
5938 * invalid frames to be safely ignored.
5939 *
5940 * With tx window sizes greater than half of the tx window
5941 * maximum, the frame is invalid and cannot be ignored. This
5942 * causes a disconnect.
5943 */
5944
5945 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
5946 BT_DBG("Invalid/Ignore - txseq outside tx window");
5947 return L2CAP_TXSEQ_INVALID_IGNORE;
5948 } else {
5949 BT_DBG("Invalid - txseq outside tx window");
5950 return L2CAP_TXSEQ_INVALID;
5951 }
5952 } else {
5953 BT_DBG("Unexpected - txseq indicates missing frames");
5954 return L2CAP_TXSEQ_UNEXPECTED;
5955 }
5956 }
5957
5958 static int l2cap_rx_state_recv(struct l2cap_chan *chan,
5959 struct l2cap_ctrl *control,
5960 struct sk_buff *skb, u8 event)
5961 {
5962 struct l2cap_ctrl local_control;
5963 int err = 0;
5964 bool skb_in_use = false;
5965
5966 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
5967 event);
5968
5969 switch (event) {
5970 case L2CAP_EV_RECV_IFRAME:
5971 switch (l2cap_classify_txseq(chan, control->txseq)) {
5972 case L2CAP_TXSEQ_EXPECTED:
5973 l2cap_pass_to_tx(chan, control);
5974
5975 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5976 BT_DBG("Busy, discarding expected seq %d",
5977 control->txseq);
5978 break;
5979 }
5980
5981 chan->expected_tx_seq = __next_seq(chan,
5982 control->txseq);
5983
5984 chan->buffer_seq = chan->expected_tx_seq;
5985 skb_in_use = true;
5986
5987 /* l2cap_reassemble_sdu may free skb, hence invalidate
5988 * control, so make a copy in advance to use it after
5989 * l2cap_reassemble_sdu returns and to avoid the race
5990 * condition, for example:
5991 *
5992 * The current thread calls:
5993 * l2cap_reassemble_sdu
5994 * chan->ops->recv == l2cap_sock_recv_cb
5995 * __sock_queue_rcv_skb
5996 * Another thread calls:
5997 * bt_sock_recvmsg
5998 * skb_recv_datagram
5999 * skb_free_datagram
6000 * Then the current thread tries to access control, but
6001 * it was freed by skb_free_datagram.
6002 */
6003 local_control = *control;
6004 err = l2cap_reassemble_sdu(chan, skb, control);
6005 if (err)
6006 break;
6007
6008 if (local_control.final) {
6009 if (!test_and_clear_bit(CONN_REJ_ACT,
6010 &chan->conn_state)) {
6011 local_control.final = 0;
6012 l2cap_retransmit_all(chan, &local_control);
6013 l2cap_ertm_send(chan);
6014 }
6015 }
6016
6017 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
6018 l2cap_send_ack(chan);
6019 break;
6020 case L2CAP_TXSEQ_UNEXPECTED:
6021 l2cap_pass_to_tx(chan, control);
6022
6023 /* Can't issue SREJ frames in the local busy state.
6024 * Drop this frame, it will be seen as missing
6025 * when local busy is exited.
6026 */
6027 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6028 BT_DBG("Busy, discarding unexpected seq %d",
6029 control->txseq);
6030 break;
6031 }
6032
6033 /* There was a gap in the sequence, so an SREJ
6034 * must be sent for each missing frame. The
6035 * current frame is stored for later use.
6036 */
6037 skb_queue_tail(&chan->srej_q, skb);
6038 skb_in_use = true;
6039 BT_DBG("Queued %p (queue len %d)", skb,
6040 skb_queue_len(&chan->srej_q));
6041
6042 clear_bit(CONN_SREJ_ACT, &chan->conn_state);
6043 l2cap_seq_list_clear(&chan->srej_list);
6044 l2cap_send_srej(chan, control->txseq);
6045
6046 chan->rx_state = L2CAP_RX_STATE_SREJ_SENT;
6047 break;
6048 case L2CAP_TXSEQ_DUPLICATE:
6049 l2cap_pass_to_tx(chan, control);
6050 break;
6051 case L2CAP_TXSEQ_INVALID_IGNORE:
6052 break;
6053 case L2CAP_TXSEQ_INVALID:
6054 default:
6055 l2cap_send_disconn_req(chan, ECONNRESET);
6056 break;
6057 }
6058 break;
6059 case L2CAP_EV_RECV_RR:
6060 l2cap_pass_to_tx(chan, control);
6061 if (control->final) {
6062 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6063
6064 if (!test_and_clear_bit(CONN_REJ_ACT,
6065 &chan->conn_state)) {
6066 control->final = 0;
6067 l2cap_retransmit_all(chan, control);
6068 }
6069
6070 l2cap_ertm_send(chan);
6071 } else if (control->poll) {
6072 l2cap_send_i_or_rr_or_rnr(chan);
6073 } else {
6074 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6075 &chan->conn_state) &&
6076 chan->unacked_frames)
6077 __set_retrans_timer(chan);
6078
6079 l2cap_ertm_send(chan);
6080 }
6081 break;
6082 case L2CAP_EV_RECV_RNR:
6083 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6084 l2cap_pass_to_tx(chan, control);
6085 if (control && control->poll) {
6086 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6087 l2cap_send_rr_or_rnr(chan, 0);
6088 }
6089 __clear_retrans_timer(chan);
6090 l2cap_seq_list_clear(&chan->retrans_list);
6091 break;
6092 case L2CAP_EV_RECV_REJ:
6093 l2cap_handle_rej(chan, control);
6094 break;
6095 case L2CAP_EV_RECV_SREJ:
6096 l2cap_handle_srej(chan, control);
6097 break;
6098 default:
6099 break;
6100 }
6101
6102 if (skb && !skb_in_use) {
6103 BT_DBG("Freeing %p", skb);
6104 kfree_skb(skb);
6105 }
6106
6107 return err;
6108 }
6109
6110 static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan,
6111 struct l2cap_ctrl *control,
6112 struct sk_buff *skb, u8 event)
6113 {
6114 int err = 0;
6115 u16 txseq = control->txseq;
6116 bool skb_in_use = false;
6117
6118 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6119 event);
6120
6121 switch (event) {
6122 case L2CAP_EV_RECV_IFRAME:
6123 switch (l2cap_classify_txseq(chan, txseq)) {
6124 case L2CAP_TXSEQ_EXPECTED:
6125 /* Keep frame for reassembly later */
6126 l2cap_pass_to_tx(chan, control);
6127 skb_queue_tail(&chan->srej_q, skb);
6128 skb_in_use = true;
6129 BT_DBG("Queued %p (queue len %d)", skb,
6130 skb_queue_len(&chan->srej_q));
6131
6132 chan->expected_tx_seq = __next_seq(chan, txseq);
6133 break;
6134 case L2CAP_TXSEQ_EXPECTED_SREJ:
6135 l2cap_seq_list_pop(&chan->srej_list);
6136
6137 l2cap_pass_to_tx(chan, control);
6138 skb_queue_tail(&chan->srej_q, skb);
6139 skb_in_use = true;
6140 BT_DBG("Queued %p (queue len %d)", skb,
6141 skb_queue_len(&chan->srej_q));
6142
6143 err = l2cap_rx_queued_iframes(chan);
6144 if (err)
6145 break;
6146
6147 break;
6148 case L2CAP_TXSEQ_UNEXPECTED:
6149 /* Got a frame that can't be reassembled yet.
6150 * Save it for later, and send SREJs to cover
6151 * the missing frames.
6152 */
6153 skb_queue_tail(&chan->srej_q, skb);
6154 skb_in_use = true;
6155 BT_DBG("Queued %p (queue len %d)", skb,
6156 skb_queue_len(&chan->srej_q));
6157
6158 l2cap_pass_to_tx(chan, control);
6159 l2cap_send_srej(chan, control->txseq);
6160 break;
6161 case L2CAP_TXSEQ_UNEXPECTED_SREJ:
6162 /* This frame was requested with an SREJ, but
6163 * some expected retransmitted frames are
6164 * missing. Request retransmission of missing
6165 * SREJ'd frames.
6166 */
6167 skb_queue_tail(&chan->srej_q, skb);
6168 skb_in_use = true;
6169 BT_DBG("Queued %p (queue len %d)", skb,
6170 skb_queue_len(&chan->srej_q));
6171
6172 l2cap_pass_to_tx(chan, control);
6173 l2cap_send_srej_list(chan, control->txseq);
6174 break;
6175 case L2CAP_TXSEQ_DUPLICATE_SREJ:
6176 /* We've already queued this frame. Drop this copy. */
6177 l2cap_pass_to_tx(chan, control);
6178 break;
6179 case L2CAP_TXSEQ_DUPLICATE:
6180 /* Expecting a later sequence number, so this frame
6181 * was already received. Ignore it completely.
6182 */
6183 break;
6184 case L2CAP_TXSEQ_INVALID_IGNORE:
6185 break;
6186 case L2CAP_TXSEQ_INVALID:
6187 default:
6188 l2cap_send_disconn_req(chan, ECONNRESET);
6189 break;
6190 }
6191 break;
6192 case L2CAP_EV_RECV_RR:
6193 l2cap_pass_to_tx(chan, control);
6194 if (control->final) {
6195 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6196
6197 if (!test_and_clear_bit(CONN_REJ_ACT,
6198 &chan->conn_state)) {
6199 control->final = 0;
6200 l2cap_retransmit_all(chan, control);
6201 }
6202
6203 l2cap_ertm_send(chan);
6204 } else if (control->poll) {
6205 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6206 &chan->conn_state) &&
6207 chan->unacked_frames) {
6208 __set_retrans_timer(chan);
6209 }
6210
6211 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6212 l2cap_send_srej_tail(chan);
6213 } else {
6214 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6215 &chan->conn_state) &&
6216 chan->unacked_frames)
6217 __set_retrans_timer(chan);
6218
6219 l2cap_send_ack(chan);
6220 }
6221 break;
6222 case L2CAP_EV_RECV_RNR:
6223 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6224 l2cap_pass_to_tx(chan, control);
6225 if (control->poll) {
6226 l2cap_send_srej_tail(chan);
6227 } else {
6228 struct l2cap_ctrl rr_control;
6229 memset(&rr_control, 0, sizeof(rr_control));
6230 rr_control.sframe = 1;
6231 rr_control.super = L2CAP_SUPER_RR;
6232 rr_control.reqseq = chan->buffer_seq;
6233 l2cap_send_sframe(chan, &rr_control);
6234 }
6235
6236 break;
6237 case L2CAP_EV_RECV_REJ:
6238 l2cap_handle_rej(chan, control);
6239 break;
6240 case L2CAP_EV_RECV_SREJ:
6241 l2cap_handle_srej(chan, control);
6242 break;
6243 }
6244
6245 if (skb && !skb_in_use) {
6246 BT_DBG("Freeing %p", skb);
6247 kfree_skb(skb);
6248 }
6249
6250 return err;
6251 }
6252
6253 static int l2cap_finish_move(struct l2cap_chan *chan)
6254 {
6255 BT_DBG("chan %p", chan);
6256
6257 chan->rx_state = L2CAP_RX_STATE_RECV;
6258 chan->conn->mtu = chan->conn->hcon->mtu;
6259
6260 return l2cap_resegment(chan);
6261 }
6262
6263 static int l2cap_rx_state_wait_p(struct l2cap_chan *chan,
6264 struct l2cap_ctrl *control,
6265 struct sk_buff *skb, u8 event)
6266 {
6267 int err;
6268
6269 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6270 event);
6271
6272 if (!control->poll)
6273 return -EPROTO;
6274
6275 l2cap_process_reqseq(chan, control->reqseq);
6276
6277 if (!skb_queue_empty(&chan->tx_q))
6278 chan->tx_send_head = skb_peek(&chan->tx_q);
6279 else
6280 chan->tx_send_head = NULL;
6281
6282 /* Rewind next_tx_seq to the point expected
6283 * by the receiver.
6284 */
6285 chan->next_tx_seq = control->reqseq;
6286 chan->unacked_frames = 0;
6287
6288 err = l2cap_finish_move(chan);
6289 if (err)
6290 return err;
6291
6292 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6293 l2cap_send_i_or_rr_or_rnr(chan);
6294
6295 if (event == L2CAP_EV_RECV_IFRAME)
6296 return -EPROTO;
6297
6298 return l2cap_rx_state_recv(chan, control, NULL, event);
6299 }
6300
6301 static int l2cap_rx_state_wait_f(struct l2cap_chan *chan,
6302 struct l2cap_ctrl *control,
6303 struct sk_buff *skb, u8 event)
6304 {
6305 int err;
6306
6307 if (!control->final)
6308 return -EPROTO;
6309
6310 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6311
6312 chan->rx_state = L2CAP_RX_STATE_RECV;
6313 l2cap_process_reqseq(chan, control->reqseq);
6314
6315 if (!skb_queue_empty(&chan->tx_q))
6316 chan->tx_send_head = skb_peek(&chan->tx_q);
6317 else
6318 chan->tx_send_head = NULL;
6319
6320 /* Rewind next_tx_seq to the point expected
6321 * by the receiver.
6322 */
6323 chan->next_tx_seq = control->reqseq;
6324 chan->unacked_frames = 0;
6325 chan->conn->mtu = chan->conn->hcon->mtu;
6326
6327 err = l2cap_resegment(chan);
6328
6329 if (!err)
6330 err = l2cap_rx_state_recv(chan, control, skb, event);
6331
6332 return err;
6333 }
6334
6335 static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq)
6336 {
6337 /* Make sure reqseq is for a packet that has been sent but not acked */
6338 u16 unacked;
6339
6340 unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq);
6341 return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked;
6342 }
6343
6344 static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
6345 struct sk_buff *skb, u8 event)
6346 {
6347 int err = 0;
6348
6349 BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan,
6350 control, skb, event, chan->rx_state);
6351
6352 if (__valid_reqseq(chan, control->reqseq)) {
6353 switch (chan->rx_state) {
6354 case L2CAP_RX_STATE_RECV:
6355 err = l2cap_rx_state_recv(chan, control, skb, event);
6356 break;
6357 case L2CAP_RX_STATE_SREJ_SENT:
6358 err = l2cap_rx_state_srej_sent(chan, control, skb,
6359 event);
6360 break;
6361 case L2CAP_RX_STATE_WAIT_P:
6362 err = l2cap_rx_state_wait_p(chan, control, skb, event);
6363 break;
6364 case L2CAP_RX_STATE_WAIT_F:
6365 err = l2cap_rx_state_wait_f(chan, control, skb, event);
6366 break;
6367 default:
6368 /* shut it down */
6369 break;
6370 }
6371 } else {
6372 BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d",
6373 control->reqseq, chan->next_tx_seq,
6374 chan->expected_ack_seq);
6375 l2cap_send_disconn_req(chan, ECONNRESET);
6376 }
6377
6378 return err;
6379 }
6380
6381 static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
6382 struct sk_buff *skb)
6383 {
6384 /* l2cap_reassemble_sdu may free skb, hence invalidate control, so store
6385 * the txseq field in advance to use it after l2cap_reassemble_sdu
6386 * returns and to avoid the race condition, for example:
6387 *
6388 * The current thread calls:
6389 * l2cap_reassemble_sdu
6390 * chan->ops->recv == l2cap_sock_recv_cb
6391 * __sock_queue_rcv_skb
6392 * Another thread calls:
6393 * bt_sock_recvmsg
6394 * skb_recv_datagram
6395 * skb_free_datagram
6396 * Then the current thread tries to access control, but it was freed by
6397 * skb_free_datagram.
6398 */
6399 u16 txseq = control->txseq;
6400
6401 BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb,
6402 chan->rx_state);
6403
6404 if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) {
6405 l2cap_pass_to_tx(chan, control);
6406
6407 BT_DBG("buffer_seq %u->%u", chan->buffer_seq,
6408 __next_seq(chan, chan->buffer_seq));
6409
6410 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
6411
6412 l2cap_reassemble_sdu(chan, skb, control);
6413 } else {
6414 if (chan->sdu) {
6415 kfree_skb(chan->sdu);
6416 chan->sdu = NULL;
6417 }
6418 chan->sdu_last_frag = NULL;
6419 chan->sdu_len = 0;
6420
6421 if (skb) {
6422 BT_DBG("Freeing %p", skb);
6423 kfree_skb(skb);
6424 }
6425 }
6426
6427 chan->last_acked_seq = txseq;
6428 chan->expected_tx_seq = __next_seq(chan, txseq);
6429
6430 return 0;
6431 }
6432
6433 static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
6434 {
6435 struct l2cap_ctrl *control = &bt_cb(skb)->l2cap;
6436 u16 len;
6437 u8 event;
6438
6439 __unpack_control(chan, skb);
6440
6441 len = skb->len;
6442
6443 /*
6444 * We can just drop the corrupted I-frame here.
6445 * Receiver will miss it and start proper recovery
6446 * procedures and ask for retransmission.
6447 */
6448 if (l2cap_check_fcs(chan, skb))
6449 goto drop;
6450
6451 if (!control->sframe && control->sar == L2CAP_SAR_START)
6452 len -= L2CAP_SDULEN_SIZE;
6453
6454 if (chan->fcs == L2CAP_FCS_CRC16)
6455 len -= L2CAP_FCS_SIZE;
6456
6457 if (len > chan->mps) {
6458 l2cap_send_disconn_req(chan, ECONNRESET);
6459 goto drop;
6460 }
6461
6462 if (chan->ops->filter) {
6463 if (chan->ops->filter(chan, skb))
6464 goto drop;
6465 }
6466
6467 if (!control->sframe) {
6468 int err;
6469
6470 BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d",
6471 control->sar, control->reqseq, control->final,
6472 control->txseq);
6473
6474 /* Validate F-bit - F=0 always valid, F=1 only
6475 * valid in TX WAIT_F
6476 */
6477 if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F)
6478 goto drop;
6479
6480 if (chan->mode != L2CAP_MODE_STREAMING) {
6481 event = L2CAP_EV_RECV_IFRAME;
6482 err = l2cap_rx(chan, control, skb, event);
6483 } else {
6484 err = l2cap_stream_rx(chan, control, skb);
6485 }
6486
6487 if (err)
6488 l2cap_send_disconn_req(chan, ECONNRESET);
6489 } else {
6490 const u8 rx_func_to_event[4] = {
6491 L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ,
6492 L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ
6493 };
6494
6495 /* Only I-frames are expected in streaming mode */
6496 if (chan->mode == L2CAP_MODE_STREAMING)
6497 goto drop;
6498
6499 BT_DBG("sframe reqseq %d, final %d, poll %d, super %d",
6500 control->reqseq, control->final, control->poll,
6501 control->super);
6502
6503 if (len != 0) {
6504 BT_ERR("Trailing bytes: %d in sframe", len);
6505 l2cap_send_disconn_req(chan, ECONNRESET);
6506 goto drop;
6507 }
6508
6509 /* Validate F and P bits */
6510 if (control->final && (control->poll ||
6511 chan->tx_state != L2CAP_TX_STATE_WAIT_F))
6512 goto drop;
6513
6514 event = rx_func_to_event[control->super];
6515 if (l2cap_rx(chan, control, skb, event))
6516 l2cap_send_disconn_req(chan, ECONNRESET);
6517 }
6518
6519 return 0;
6520
6521 drop:
6522 kfree_skb(skb);
6523 return 0;
6524 }
6525
6526 static void l2cap_chan_le_send_credits(struct l2cap_chan *chan)
6527 {
6528 struct l2cap_conn *conn = chan->conn;
6529 struct l2cap_le_credits pkt;
6530 u16 return_credits = l2cap_le_rx_credits(chan);
6531
6532 if (chan->rx_credits >= return_credits)
6533 return;
6534
6535 return_credits -= chan->rx_credits;
6536
6537 BT_DBG("chan %p returning %u credits to sender", chan, return_credits);
6538
6539 chan->rx_credits += return_credits;
6540
6541 pkt.cid = cpu_to_le16(chan->scid);
6542 pkt.credits = cpu_to_le16(return_credits);
6543
6544 chan->ident = l2cap_get_ident(conn);
6545
6546 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt);
6547 }
6548
6549 void l2cap_chan_rx_avail(struct l2cap_chan *chan, ssize_t rx_avail)
6550 {
6551 if (chan->rx_avail == rx_avail)
6552 return;
6553
6554 BT_DBG("chan %p has %zd bytes avail for rx", chan, rx_avail);
6555
6556 chan->rx_avail = rx_avail;
6557
6558 if (chan->state == BT_CONNECTED)
6559 l2cap_chan_le_send_credits(chan);
6560 }
6561
6562 static int l2cap_ecred_recv(struct l2cap_chan *chan, struct sk_buff *skb)
6563 {
6564 int err;
6565
6566 BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len);
6567
6568 /* Wait recv to confirm reception before updating the credits */
6569 err = chan->ops->recv(chan, skb);
6570
6571 if (err < 0 && chan->rx_avail != -1) {
6572 BT_ERR("Queueing received LE L2CAP data failed");
6573 l2cap_send_disconn_req(chan, ECONNRESET);
6574 return err;
6575 }
6576
6577 /* Update credits whenever an SDU is received */
6578 l2cap_chan_le_send_credits(chan);
6579
6580 return err;
6581 }
6582
6583 static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
6584 {
6585 int err;
6586
6587 if (!chan->rx_credits) {
6588 BT_ERR("No credits to receive LE L2CAP data");
6589 l2cap_send_disconn_req(chan, ECONNRESET);
6590 return -ENOBUFS;
6591 }
6592
6593 if (chan->imtu < skb->len) {
6594 BT_ERR("Too big LE L2CAP PDU");
6595 return -ENOBUFS;
6596 }
6597
6598 chan->rx_credits--;
6599 BT_DBG("chan %p: rx_credits %u -> %u",
6600 chan, chan->rx_credits + 1, chan->rx_credits);
6601
6602 /* Update if remote had run out of credits, this should only happens
6603 * if the remote is not using the entire MPS.
6604 */
6605 if (!chan->rx_credits)
6606 l2cap_chan_le_send_credits(chan);
6607
6608 err = 0;
6609
6610 if (!chan->sdu) {
6611 u16 sdu_len;
6612
6613 sdu_len = get_unaligned_le16(skb->data);
6614 skb_pull(skb, L2CAP_SDULEN_SIZE);
6615
6616 BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u",
6617 sdu_len, skb->len, chan->imtu);
6618
6619 if (sdu_len > chan->imtu) {
6620 BT_ERR("Too big LE L2CAP SDU length received");
6621 err = -EMSGSIZE;
6622 goto failed;
6623 }
6624
6625 if (skb->len > sdu_len) {
6626 BT_ERR("Too much LE L2CAP data received");
6627 err = -EINVAL;
6628 goto failed;
6629 }
6630
6631 if (skb->len == sdu_len)
6632 return l2cap_ecred_recv(chan, skb);
6633
6634 chan->sdu = skb;
6635 chan->sdu_len = sdu_len;
6636 chan->sdu_last_frag = skb;
6637
6638 /* Detect if remote is not able to use the selected MPS */
6639 if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) {
6640 u16 mps_len = skb->len + L2CAP_SDULEN_SIZE;
6641
6642 /* Adjust the number of credits */
6643 BT_DBG("chan->mps %u -> %u", chan->mps, mps_len);
6644 chan->mps = mps_len;
6645 l2cap_chan_le_send_credits(chan);
6646 }
6647
6648 return 0;
6649 }
6650
6651 BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u",
6652 chan->sdu->len, skb->len, chan->sdu_len);
6653
6654 if (chan->sdu->len + skb->len > chan->sdu_len) {
6655 BT_ERR("Too much LE L2CAP data received");
6656 err = -EINVAL;
6657 goto failed;
6658 }
6659
6660 append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag);
6661 skb = NULL;
6662
6663 if (chan->sdu->len == chan->sdu_len) {
6664 err = l2cap_ecred_recv(chan, chan->sdu);
6665 if (!err) {
6666 chan->sdu = NULL;
6667 chan->sdu_last_frag = NULL;
6668 chan->sdu_len = 0;
6669 }
6670 }
6671
6672 failed:
6673 if (err) {
6674 kfree_skb(skb);
6675 kfree_skb(chan->sdu);
6676 chan->sdu = NULL;
6677 chan->sdu_last_frag = NULL;
6678 chan->sdu_len = 0;
6679 }
6680
6681 /* We can't return an error here since we took care of the skb
6682 * freeing internally. An error return would cause the caller to
6683 * do a double-free of the skb.
6684 */
6685 return 0;
6686 }
6687
6688 static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,
6689 struct sk_buff *skb)
6690 {
6691 struct l2cap_chan *chan;
6692
6693 chan = l2cap_get_chan_by_scid(conn, cid);
6694 if (!chan) {
6695 BT_DBG("unknown cid 0x%4.4x", cid);
6696 /* Drop packet and return */
6697 kfree_skb(skb);
6698 return;
6699 }
6700
6701 BT_DBG("chan %p, len %d", chan, skb->len);
6702
6703 /* If we receive data on a fixed channel before the info req/rsp
6704 * procedure is done simply assume that the channel is supported
6705 * and mark it as ready.
6706 */
6707 if (chan->chan_type == L2CAP_CHAN_FIXED)
6708 l2cap_chan_ready(chan);
6709
6710 if (chan->state != BT_CONNECTED)
6711 goto drop;
6712
6713 switch (chan->mode) {
6714 case L2CAP_MODE_LE_FLOWCTL:
6715 case L2CAP_MODE_EXT_FLOWCTL:
6716 if (l2cap_ecred_data_rcv(chan, skb) < 0)
6717 goto drop;
6718
6719 goto done;
6720
6721 case L2CAP_MODE_BASIC:
6722 /* If socket recv buffers overflows we drop data here
6723 * which is *bad* because L2CAP has to be reliable.
6724 * But we don't have any other choice. L2CAP doesn't
6725 * provide flow control mechanism. */
6726
6727 if (chan->imtu < skb->len) {
6728 BT_ERR("Dropping L2CAP data: receive buffer overflow");
6729 goto drop;
6730 }
6731
6732 if (!chan->ops->recv(chan, skb))
6733 goto done;
6734 break;
6735
6736 case L2CAP_MODE_ERTM:
6737 case L2CAP_MODE_STREAMING:
6738 l2cap_data_rcv(chan, skb);
6739 goto done;
6740
6741 default:
6742 BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode);
6743 break;
6744 }
6745
6746 drop:
6747 kfree_skb(skb);
6748
6749 done:
6750 l2cap_chan_unlock(chan);
6751 l2cap_chan_put(chan);
6752 }
6753
6754 static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm,
6755 struct sk_buff *skb)
6756 {
6757 struct hci_conn *hcon = conn->hcon;
6758 struct l2cap_chan *chan;
6759
6760 if (hcon->type != ACL_LINK)
6761 goto free_skb;
6762
6763 chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst,
6764 ACL_LINK);
6765 if (!chan)
6766 goto free_skb;
6767
6768 BT_DBG("chan %p, len %d", chan, skb->len);
6769
6770 if (chan->state != BT_BOUND && chan->state != BT_CONNECTED)
6771 goto drop;
6772
6773 if (chan->imtu < skb->len)
6774 goto drop;
6775
6776 /* Store remote BD_ADDR and PSM for msg_name */
6777 bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst);
6778 bt_cb(skb)->l2cap.psm = psm;
6779
6780 if (!chan->ops->recv(chan, skb)) {
6781 l2cap_chan_put(chan);
6782 return;
6783 }
6784
6785 drop:
6786 l2cap_chan_put(chan);
6787 free_skb:
6788 kfree_skb(skb);
6789 }
6790
6791 static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
6792 {
6793 struct l2cap_hdr *lh = (void *) skb->data;
6794 struct hci_conn *hcon = conn->hcon;
6795 u16 cid, len;
6796 __le16 psm;
6797
6798 if (hcon->state != BT_CONNECTED) {
6799 BT_DBG("queueing pending rx skb");
6800 skb_queue_tail(&conn->pending_rx, skb);
6801 return;
6802 }
6803
6804 skb_pull(skb, L2CAP_HDR_SIZE);
6805 cid = __le16_to_cpu(lh->cid);
6806 len = __le16_to_cpu(lh->len);
6807
6808 if (len != skb->len) {
6809 kfree_skb(skb);
6810 return;
6811 }
6812
6813 /* Since we can't actively block incoming LE connections we must
6814 * at least ensure that we ignore incoming data from them.
6815 */
6816 if (hcon->type == LE_LINK &&
6817 hci_bdaddr_list_lookup(&hcon->hdev->reject_list, &hcon->dst,
6818 bdaddr_dst_type(hcon))) {
6819 kfree_skb(skb);
6820 return;
6821 }
6822
6823 BT_DBG("len %d, cid 0x%4.4x", len, cid);
6824
6825 switch (cid) {
6826 case L2CAP_CID_SIGNALING:
6827 l2cap_sig_channel(conn, skb);
6828 break;
6829
6830 case L2CAP_CID_CONN_LESS:
6831 psm = get_unaligned((__le16 *) skb->data);
6832 skb_pull(skb, L2CAP_PSMLEN_SIZE);
6833 l2cap_conless_channel(conn, psm, skb);
6834 break;
6835
6836 case L2CAP_CID_LE_SIGNALING:
6837 l2cap_le_sig_channel(conn, skb);
6838 break;
6839
6840 default:
6841 l2cap_data_channel(conn, cid, skb);
6842 break;
6843 }
6844 }
6845
6846 static void process_pending_rx(struct work_struct *work)
6847 {
6848 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
6849 pending_rx_work);
6850 struct sk_buff *skb;
6851
6852 BT_DBG("");
6853
6854 while ((skb = skb_dequeue(&conn->pending_rx)))
6855 l2cap_recv_frame(conn, skb);
6856 }
6857
6858 static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon)
6859 {
6860 struct l2cap_conn *conn = hcon->l2cap_data;
6861 struct hci_chan *hchan;
6862
6863 if (conn)
6864 return conn;
6865
6866 hchan = hci_chan_create(hcon);
6867 if (!hchan)
6868 return NULL;
6869
6870 conn = kzalloc(sizeof(*conn), GFP_KERNEL);
6871 if (!conn) {
6872 hci_chan_del(hchan);
6873 return NULL;
6874 }
6875
6876 kref_init(&conn->ref);
6877 hcon->l2cap_data = conn;
6878 conn->hcon = hci_conn_get(hcon);
6879 conn->hchan = hchan;
6880
6881 BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan);
6882
6883 conn->mtu = hcon->mtu;
6884 conn->feat_mask = 0;
6885
6886 conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS;
6887
6888 if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) &&
6889 (bredr_sc_enabled(hcon->hdev) ||
6890 hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP)))
6891 conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR;
6892
6893 mutex_init(&conn->ident_lock);
6894 mutex_init(&conn->chan_lock);
6895
6896 INIT_LIST_HEAD(&conn->chan_l);
6897 INIT_LIST_HEAD(&conn->users);
6898
6899 INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout);
6900
6901 skb_queue_head_init(&conn->pending_rx);
6902 INIT_WORK(&conn->pending_rx_work, process_pending_rx);
6903 INIT_DELAYED_WORK(&conn->id_addr_timer, l2cap_conn_update_id_addr);
6904
6905 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
6906
6907 return conn;
6908 }
6909
6910 static bool is_valid_psm(u16 psm, u8 dst_type)
6911 {
6912 if (!psm)
6913 return false;
6914
6915 if (bdaddr_type_is_le(dst_type))
6916 return (psm <= 0x00ff);
6917
6918 /* PSM must be odd and lsb of upper byte must be 0 */
6919 return ((psm & 0x0101) == 0x0001);
6920 }
6921
6922 struct l2cap_chan_data {
6923 struct l2cap_chan *chan;
6924 struct pid *pid;
6925 int count;
6926 };
6927
6928 static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data)
6929 {
6930 struct l2cap_chan_data *d = data;
6931 struct pid *pid;
6932
6933 if (chan == d->chan)
6934 return;
6935
6936 if (!test_bit(FLAG_DEFER_SETUP, &chan->flags))
6937 return;
6938
6939 pid = chan->ops->get_peer_pid(chan);
6940
6941 /* Only count deferred channels with the same PID/PSM */
6942 if (d->pid != pid || chan->psm != d->chan->psm || chan->ident ||
6943 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
6944 return;
6945
6946 d->count++;
6947 }
6948
6949 int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
6950 bdaddr_t *dst, u8 dst_type, u16 timeout)
6951 {
6952 struct l2cap_conn *conn;
6953 struct hci_conn *hcon;
6954 struct hci_dev *hdev;
6955 int err;
6956
6957 BT_DBG("%pMR -> %pMR (type %u) psm 0x%4.4x mode 0x%2.2x", &chan->src,
6958 dst, dst_type, __le16_to_cpu(psm), chan->mode);
6959
6960 hdev = hci_get_route(dst, &chan->src, chan->src_type);
6961 if (!hdev)
6962 return -EHOSTUNREACH;
6963
6964 hci_dev_lock(hdev);
6965
6966 if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid &&
6967 chan->chan_type != L2CAP_CHAN_RAW) {
6968 err = -EINVAL;
6969 goto done;
6970 }
6971
6972 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) {
6973 err = -EINVAL;
6974 goto done;
6975 }
6976
6977 if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) {
6978 err = -EINVAL;
6979 goto done;
6980 }
6981
6982 switch (chan->mode) {
6983 case L2CAP_MODE_BASIC:
6984 break;
6985 case L2CAP_MODE_LE_FLOWCTL:
6986 break;
6987 case L2CAP_MODE_EXT_FLOWCTL:
6988 if (!enable_ecred) {
6989 err = -EOPNOTSUPP;
6990 goto done;
6991 }
6992 break;
6993 case L2CAP_MODE_ERTM:
6994 case L2CAP_MODE_STREAMING:
6995 if (!disable_ertm)
6996 break;
6997 fallthrough;
6998 default:
6999 err = -EOPNOTSUPP;
7000 goto done;
7001 }
7002
7003 switch (chan->state) {
7004 case BT_CONNECT:
7005 case BT_CONNECT2:
7006 case BT_CONFIG:
7007 /* Already connecting */
7008 err = 0;
7009 goto done;
7010
7011 case BT_CONNECTED:
7012 /* Already connected */
7013 err = -EISCONN;
7014 goto done;
7015
7016 case BT_OPEN:
7017 case BT_BOUND:
7018 /* Can connect */
7019 break;
7020
7021 default:
7022 err = -EBADFD;
7023 goto done;
7024 }
7025
7026 /* Set destination address and psm */
7027 bacpy(&chan->dst, dst);
7028 chan->dst_type = dst_type;
7029
7030 chan->psm = psm;
7031 chan->dcid = cid;
7032
7033 if (bdaddr_type_is_le(dst_type)) {
7034 /* Convert from L2CAP channel address type to HCI address type
7035 */
7036 if (dst_type == BDADDR_LE_PUBLIC)
7037 dst_type = ADDR_LE_DEV_PUBLIC;
7038 else
7039 dst_type = ADDR_LE_DEV_RANDOM;
7040
7041 if (hci_dev_test_flag(hdev, HCI_ADVERTISING))
7042 hcon = hci_connect_le(hdev, dst, dst_type, false,
7043 chan->sec_level, timeout,
7044 HCI_ROLE_SLAVE, 0, 0);
7045 else
7046 hcon = hci_connect_le_scan(hdev, dst, dst_type,
7047 chan->sec_level, timeout,
7048 CONN_REASON_L2CAP_CHAN);
7049
7050 } else {
7051 u8 auth_type = l2cap_get_auth_type(chan);
7052 hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type,
7053 CONN_REASON_L2CAP_CHAN, timeout);
7054 }
7055
7056 if (IS_ERR(hcon)) {
7057 err = PTR_ERR(hcon);
7058 goto done;
7059 }
7060
7061 conn = l2cap_conn_add(hcon);
7062 if (!conn) {
7063 hci_conn_drop(hcon);
7064 err = -ENOMEM;
7065 goto done;
7066 }
7067
7068 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) {
7069 struct l2cap_chan_data data;
7070
7071 data.chan = chan;
7072 data.pid = chan->ops->get_peer_pid(chan);
7073 data.count = 1;
7074
7075 l2cap_chan_list(conn, l2cap_chan_by_pid, &data);
7076
7077 /* Check if there isn't too many channels being connected */
7078 if (data.count > L2CAP_ECRED_CONN_SCID_MAX) {
7079 hci_conn_drop(hcon);
7080 err = -EPROTO;
7081 goto done;
7082 }
7083 }
7084
7085 mutex_lock(&conn->chan_lock);
7086 l2cap_chan_lock(chan);
7087
7088 if (cid && __l2cap_get_chan_by_dcid(conn, cid)) {
7089 hci_conn_drop(hcon);
7090 err = -EBUSY;
7091 goto chan_unlock;
7092 }
7093
7094 /* Update source addr of the socket */
7095 bacpy(&chan->src, &hcon->src);
7096 chan->src_type = bdaddr_src_type(hcon);
7097
7098 __l2cap_chan_add(conn, chan);
7099
7100 /* l2cap_chan_add takes its own ref so we can drop this one */
7101 hci_conn_drop(hcon);
7102
7103 l2cap_state_change(chan, BT_CONNECT);
7104 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
7105
7106 /* Release chan->sport so that it can be reused by other
7107 * sockets (as it's only used for listening sockets).
7108 */
7109 write_lock(&chan_list_lock);
7110 chan->sport = 0;
7111 write_unlock(&chan_list_lock);
7112
7113 if (hcon->state == BT_CONNECTED) {
7114 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
7115 __clear_chan_timer(chan);
7116 if (l2cap_chan_check_security(chan, true))
7117 l2cap_state_change(chan, BT_CONNECTED);
7118 } else
7119 l2cap_do_start(chan);
7120 }
7121
7122 err = 0;
7123
7124 chan_unlock:
7125 l2cap_chan_unlock(chan);
7126 mutex_unlock(&conn->chan_lock);
7127 done:
7128 hci_dev_unlock(hdev);
7129 hci_dev_put(hdev);
7130 return err;
7131 }
7132 EXPORT_SYMBOL_GPL(l2cap_chan_connect);
7133
7134 static void l2cap_ecred_reconfigure(struct l2cap_chan *chan)
7135 {
7136 struct l2cap_conn *conn = chan->conn;
7137 DEFINE_RAW_FLEX(struct l2cap_ecred_reconf_req, pdu, scid, 1);
7138
7139 pdu->mtu = cpu_to_le16(chan->imtu);
7140 pdu->mps = cpu_to_le16(chan->mps);
7141 pdu->scid[0] = cpu_to_le16(chan->scid);
7142
7143 chan->ident = l2cap_get_ident(conn);
7144
7145 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ,
7146 sizeof(pdu), &pdu);
7147 }
7148
7149 int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu)
7150 {
7151 if (chan->imtu > mtu)
7152 return -EINVAL;
7153
7154 BT_DBG("chan %p mtu 0x%4.4x", chan, mtu);
7155
7156 chan->imtu = mtu;
7157
7158 l2cap_ecred_reconfigure(chan);
7159
7160 return 0;
7161 }
7162
7163 /* ---- L2CAP interface with lower layer (HCI) ---- */
7164
7165 int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr)
7166 {
7167 int exact = 0, lm1 = 0, lm2 = 0;
7168 struct l2cap_chan *c;
7169
7170 BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr);
7171
7172 /* Find listening sockets and check their link_mode */
7173 read_lock(&chan_list_lock);
7174 list_for_each_entry(c, &chan_list, global_l) {
7175 if (c->state != BT_LISTEN)
7176 continue;
7177
7178 if (!bacmp(&c->src, &hdev->bdaddr)) {
7179 lm1 |= HCI_LM_ACCEPT;
7180 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
7181 lm1 |= HCI_LM_MASTER;
7182 exact++;
7183 } else if (!bacmp(&c->src, BDADDR_ANY)) {
7184 lm2 |= HCI_LM_ACCEPT;
7185 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
7186 lm2 |= HCI_LM_MASTER;
7187 }
7188 }
7189 read_unlock(&chan_list_lock);
7190
7191 return exact ? lm1 : lm2;
7192 }
7193
7194 /* Find the next fixed channel in BT_LISTEN state, continue iteration
7195 * from an existing channel in the list or from the beginning of the
7196 * global list (by passing NULL as first parameter).
7197 */
7198 static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c,
7199 struct hci_conn *hcon)
7200 {
7201 u8 src_type = bdaddr_src_type(hcon);
7202
7203 read_lock(&chan_list_lock);
7204
7205 if (c)
7206 c = list_next_entry(c, global_l);
7207 else
7208 c = list_entry(chan_list.next, typeof(*c), global_l);
7209
7210 list_for_each_entry_from(c, &chan_list, global_l) {
7211 if (c->chan_type != L2CAP_CHAN_FIXED)
7212 continue;
7213 if (c->state != BT_LISTEN)
7214 continue;
7215 if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY))
7216 continue;
7217 if (src_type != c->src_type)
7218 continue;
7219
7220 c = l2cap_chan_hold_unless_zero(c);
7221 read_unlock(&chan_list_lock);
7222 return c;
7223 }
7224
7225 read_unlock(&chan_list_lock);
7226
7227 return NULL;
7228 }
7229
7230 static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status)
7231 {
7232 struct hci_dev *hdev = hcon->hdev;
7233 struct l2cap_conn *conn;
7234 struct l2cap_chan *pchan;
7235 u8 dst_type;
7236
7237 if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
7238 return;
7239
7240 BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status);
7241
7242 if (status) {
7243 l2cap_conn_del(hcon, bt_to_errno(status));
7244 return;
7245 }
7246
7247 conn = l2cap_conn_add(hcon);
7248 if (!conn)
7249 return;
7250
7251 dst_type = bdaddr_dst_type(hcon);
7252
7253 /* If device is blocked, do not create channels for it */
7254 if (hci_bdaddr_list_lookup(&hdev->reject_list, &hcon->dst, dst_type))
7255 return;
7256
7257 /* Find fixed channels and notify them of the new connection. We
7258 * use multiple individual lookups, continuing each time where
7259 * we left off, because the list lock would prevent calling the
7260 * potentially sleeping l2cap_chan_lock() function.
7261 */
7262 pchan = l2cap_global_fixed_chan(NULL, hcon);
7263 while (pchan) {
7264 struct l2cap_chan *chan, *next;
7265
7266 /* Client fixed channels should override server ones */
7267 if (__l2cap_get_chan_by_dcid(conn, pchan->scid))
7268 goto next;
7269
7270 l2cap_chan_lock(pchan);
7271 chan = pchan->ops->new_connection(pchan);
7272 if (chan) {
7273 bacpy(&chan->src, &hcon->src);
7274 bacpy(&chan->dst, &hcon->dst);
7275 chan->src_type = bdaddr_src_type(hcon);
7276 chan->dst_type = dst_type;
7277
7278 __l2cap_chan_add(conn, chan);
7279 }
7280
7281 l2cap_chan_unlock(pchan);
7282 next:
7283 next = l2cap_global_fixed_chan(pchan, hcon);
7284 l2cap_chan_put(pchan);
7285 pchan = next;
7286 }
7287
7288 l2cap_conn_ready(conn);
7289 }
7290
7291 int l2cap_disconn_ind(struct hci_conn *hcon)
7292 {
7293 struct l2cap_conn *conn = hcon->l2cap_data;
7294
7295 BT_DBG("hcon %p", hcon);
7296
7297 if (!conn)
7298 return HCI_ERROR_REMOTE_USER_TERM;
7299 return conn->disc_reason;
7300 }
7301
7302 static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)
7303 {
7304 if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
7305 return;
7306
7307 BT_DBG("hcon %p reason %d", hcon, reason);
7308
7309 l2cap_conn_del(hcon, bt_to_errno(reason));
7310 }
7311
7312 static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt)
7313 {
7314 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
7315 return;
7316
7317 if (encrypt == 0x00) {
7318 if (chan->sec_level == BT_SECURITY_MEDIUM) {
7319 __set_chan_timer(chan, L2CAP_ENC_TIMEOUT);
7320 } else if (chan->sec_level == BT_SECURITY_HIGH ||
7321 chan->sec_level == BT_SECURITY_FIPS)
7322 l2cap_chan_close(chan, ECONNREFUSED);
7323 } else {
7324 if (chan->sec_level == BT_SECURITY_MEDIUM)
7325 __clear_chan_timer(chan);
7326 }
7327 }
7328
7329 static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
7330 {
7331 struct l2cap_conn *conn = hcon->l2cap_data;
7332 struct l2cap_chan *chan;
7333
7334 if (!conn)
7335 return;
7336
7337 BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt);
7338
7339 mutex_lock(&conn->chan_lock);
7340
7341 list_for_each_entry(chan, &conn->chan_l, list) {
7342 l2cap_chan_lock(chan);
7343
7344 BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid,
7345 state_to_string(chan->state));
7346
7347 if (!status && encrypt)
7348 chan->sec_level = hcon->sec_level;
7349
7350 if (!__l2cap_no_conn_pending(chan)) {
7351 l2cap_chan_unlock(chan);
7352 continue;
7353 }
7354
7355 if (!status && (chan->state == BT_CONNECTED ||
7356 chan->state == BT_CONFIG)) {
7357 chan->ops->resume(chan);
7358 l2cap_check_encryption(chan, encrypt);
7359 l2cap_chan_unlock(chan);
7360 continue;
7361 }
7362
7363 if (chan->state == BT_CONNECT) {
7364 if (!status && l2cap_check_enc_key_size(hcon))
7365 l2cap_start_connection(chan);
7366 else
7367 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
7368 } else if (chan->state == BT_CONNECT2 &&
7369 !(chan->mode == L2CAP_MODE_EXT_FLOWCTL ||
7370 chan->mode == L2CAP_MODE_LE_FLOWCTL)) {
7371 struct l2cap_conn_rsp rsp;
7372 __u16 res, stat;
7373
7374 if (!status && l2cap_check_enc_key_size(hcon)) {
7375 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
7376 res = L2CAP_CR_PEND;
7377 stat = L2CAP_CS_AUTHOR_PEND;
7378 chan->ops->defer(chan);
7379 } else {
7380 l2cap_state_change(chan, BT_CONFIG);
7381 res = L2CAP_CR_SUCCESS;
7382 stat = L2CAP_CS_NO_INFO;
7383 }
7384 } else {
7385 l2cap_state_change(chan, BT_DISCONN);
7386 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
7387 res = L2CAP_CR_SEC_BLOCK;
7388 stat = L2CAP_CS_NO_INFO;
7389 }
7390
7391 rsp.scid = cpu_to_le16(chan->dcid);
7392 rsp.dcid = cpu_to_le16(chan->scid);
7393 rsp.result = cpu_to_le16(res);
7394 rsp.status = cpu_to_le16(stat);
7395 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
7396 sizeof(rsp), &rsp);
7397
7398 if (!test_bit(CONF_REQ_SENT, &chan->conf_state) &&
7399 res == L2CAP_CR_SUCCESS) {
7400 char buf[128];
7401 set_bit(CONF_REQ_SENT, &chan->conf_state);
7402 l2cap_send_cmd(conn, l2cap_get_ident(conn),
7403 L2CAP_CONF_REQ,
7404 l2cap_build_conf_req(chan, buf, sizeof(buf)),
7405 buf);
7406 chan->num_conf_req++;
7407 }
7408 }
7409
7410 l2cap_chan_unlock(chan);
7411 }
7412
7413 mutex_unlock(&conn->chan_lock);
7414 }
7415
7416 /* Append fragment into frame respecting the maximum len of rx_skb */
7417 static int l2cap_recv_frag(struct l2cap_conn *conn, struct sk_buff *skb,
7418 u16 len)
7419 {
7420 if (!conn->rx_skb) {
7421 /* Allocate skb for the complete frame (with header) */
7422 conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL);
7423 if (!conn->rx_skb)
7424 return -ENOMEM;
7425 /* Init rx_len */
7426 conn->rx_len = len;
7427 }
7428
7429 /* Copy as much as the rx_skb can hold */
7430 len = min_t(u16, len, skb->len);
7431 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, len), len);
7432 skb_pull(skb, len);
7433 conn->rx_len -= len;
7434
7435 return len;
7436 }
7437
7438 static int l2cap_recv_len(struct l2cap_conn *conn, struct sk_buff *skb)
7439 {
7440 struct sk_buff *rx_skb;
7441 int len;
7442
7443 /* Append just enough to complete the header */
7444 len = l2cap_recv_frag(conn, skb, L2CAP_LEN_SIZE - conn->rx_skb->len);
7445
7446 /* If header could not be read just continue */
7447 if (len < 0 || conn->rx_skb->len < L2CAP_LEN_SIZE)
7448 return len;
7449
7450 rx_skb = conn->rx_skb;
7451 len = get_unaligned_le16(rx_skb->data);
7452
7453 /* Check if rx_skb has enough space to received all fragments */
7454 if (len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE) <= skb_tailroom(rx_skb)) {
7455 /* Update expected len */
7456 conn->rx_len = len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE);
7457 return L2CAP_LEN_SIZE;
7458 }
7459
7460 /* Reset conn->rx_skb since it will need to be reallocated in order to
7461 * fit all fragments.
7462 */
7463 conn->rx_skb = NULL;
7464
7465 /* Reallocates rx_skb using the exact expected length */
7466 len = l2cap_recv_frag(conn, rx_skb,
7467 len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE));
7468 kfree_skb(rx_skb);
7469
7470 return len;
7471 }
7472
7473 static void l2cap_recv_reset(struct l2cap_conn *conn)
7474 {
7475 kfree_skb(conn->rx_skb);
7476 conn->rx_skb = NULL;
7477 conn->rx_len = 0;
7478 }
7479
7480 void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
7481 {
7482 struct l2cap_conn *conn = hcon->l2cap_data;
7483 int len;
7484
7485 if (!conn)
7486 conn = l2cap_conn_add(hcon);
7487
7488 if (!conn)
7489 goto drop;
7490
7491 BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags);
7492
7493 switch (flags) {
7494 case ACL_START:
7495 case ACL_START_NO_FLUSH:
7496 case ACL_COMPLETE:
7497 if (conn->rx_skb) {
7498 BT_ERR("Unexpected start frame (len %d)", skb->len);
7499 l2cap_recv_reset(conn);
7500 l2cap_conn_unreliable(conn, ECOMM);
7501 }
7502
7503 /* Start fragment may not contain the L2CAP length so just
7504 * copy the initial byte when that happens and use conn->mtu as
7505 * expected length.
7506 */
7507 if (skb->len < L2CAP_LEN_SIZE) {
7508 l2cap_recv_frag(conn, skb, conn->mtu);
7509 break;
7510 }
7511
7512 len = get_unaligned_le16(skb->data) + L2CAP_HDR_SIZE;
7513
7514 if (len == skb->len) {
7515 /* Complete frame received */
7516 l2cap_recv_frame(conn, skb);
7517 return;
7518 }
7519
7520 BT_DBG("Start: total len %d, frag len %u", len, skb->len);
7521
7522 if (skb->len > len) {
7523 BT_ERR("Frame is too long (len %u, expected len %d)",
7524 skb->len, len);
7525 l2cap_conn_unreliable(conn, ECOMM);
7526 goto drop;
7527 }
7528
7529 /* Append fragment into frame (with header) */
7530 if (l2cap_recv_frag(conn, skb, len) < 0)
7531 goto drop;
7532
7533 break;
7534
7535 case ACL_CONT:
7536 BT_DBG("Cont: frag len %u (expecting %u)", skb->len, conn->rx_len);
7537
7538 if (!conn->rx_skb) {
7539 BT_ERR("Unexpected continuation frame (len %d)", skb->len);
7540 l2cap_conn_unreliable(conn, ECOMM);
7541 goto drop;
7542 }
7543
7544 /* Complete the L2CAP length if it has not been read */
7545 if (conn->rx_skb->len < L2CAP_LEN_SIZE) {
7546 if (l2cap_recv_len(conn, skb) < 0) {
7547 l2cap_conn_unreliable(conn, ECOMM);
7548 goto drop;
7549 }
7550
7551 /* Header still could not be read just continue */
7552 if (conn->rx_skb->len < L2CAP_LEN_SIZE)
7553 break;
7554 }
7555
7556 if (skb->len > conn->rx_len) {
7557 BT_ERR("Fragment is too long (len %u, expected %u)",
7558 skb->len, conn->rx_len);
7559 l2cap_recv_reset(conn);
7560 l2cap_conn_unreliable(conn, ECOMM);
7561 goto drop;
7562 }
7563
7564 /* Append fragment into frame (with header) */
7565 l2cap_recv_frag(conn, skb, skb->len);
7566
7567 if (!conn->rx_len) {
7568 /* Complete frame received. l2cap_recv_frame
7569 * takes ownership of the skb so set the global
7570 * rx_skb pointer to NULL first.
7571 */
7572 struct sk_buff *rx_skb = conn->rx_skb;
7573 conn->rx_skb = NULL;
7574 l2cap_recv_frame(conn, rx_skb);
7575 }
7576 break;
7577 }
7578
7579 drop:
7580 kfree_skb(skb);
7581 }
7582
7583 static struct hci_cb l2cap_cb = {
7584 .name = "L2CAP",
7585 .connect_cfm = l2cap_connect_cfm,
7586 .disconn_cfm = l2cap_disconn_cfm,
7587 .security_cfm = l2cap_security_cfm,
7588 };
7589
7590 static int l2cap_debugfs_show(struct seq_file *f, void *p)
7591 {
7592 struct l2cap_chan *c;
7593
7594 read_lock(&chan_list_lock);
7595
7596 list_for_each_entry(c, &chan_list, global_l) {
7597 seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n",
7598 &c->src, c->src_type, &c->dst, c->dst_type,
7599 c->state, __le16_to_cpu(c->psm),
7600 c->scid, c->dcid, c->imtu, c->omtu,
7601 c->sec_level, c->mode);
7602 }
7603
7604 read_unlock(&chan_list_lock);
7605
7606 return 0;
7607 }
7608
7609 DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs);
7610
7611 static struct dentry *l2cap_debugfs;
7612
7613 int __init l2cap_init(void)
7614 {
7615 int err;
7616
7617 err = l2cap_init_sockets();
7618 if (err < 0)
7619 return err;
7620
7621 hci_register_cb(&l2cap_cb);
7622
7623 if (IS_ERR_OR_NULL(bt_debugfs))
7624 return 0;
7625
7626 l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs,
7627 NULL, &l2cap_debugfs_fops);
7628
7629 return 0;
7630 }
7631
7632 void l2cap_exit(void)
7633 {
7634 debugfs_remove(l2cap_debugfs);
7635 hci_unregister_cb(&l2cap_cb);
7636 l2cap_cleanup_sockets();
7637 }
7638
7639 module_param(disable_ertm, bool, 0644);
7640 MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode");
7641
7642 module_param(enable_ecred, bool, 0644);
7643 MODULE_PARM_DESC(enable_ecred, "Enable enhanced credit flow control mode");
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