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 #include "a2mp.h"
43 #include "amp.h"
44
45 #define LE_FLOWCTL_MAX_CREDITS 65535
46
47 bool disable_ertm;
48 bool enable_ecred;
49
50 static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN | L2CAP_FEAT_UCD;
51
52 static LIST_HEAD(chan_list);
53 static DEFINE_RWLOCK(chan_list_lock);
54
55 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
56 u8 code, u8 ident, u16 dlen, void *data);
57 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
58 void *data);
59 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size);
60 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err);
61
62 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
63 struct sk_buff_head *skbs, u8 event);
64 static void l2cap_retrans_timeout(struct work_struct *work);
65 static void l2cap_monitor_timeout(struct work_struct *work);
66 static void l2cap_ack_timeout(struct work_struct *work);
67
bdaddr_type(u8 link_type,u8 bdaddr_type)68 static inline u8 bdaddr_type(u8 link_type, u8 bdaddr_type)
69 {
70 if (link_type == LE_LINK) {
71 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
72 return BDADDR_LE_PUBLIC;
73 else
74 return BDADDR_LE_RANDOM;
75 }
76
77 return BDADDR_BREDR;
78 }
79
bdaddr_src_type(struct hci_conn * hcon)80 static inline u8 bdaddr_src_type(struct hci_conn *hcon)
81 {
82 return bdaddr_type(hcon->type, hcon->src_type);
83 }
84
bdaddr_dst_type(struct hci_conn * hcon)85 static inline u8 bdaddr_dst_type(struct hci_conn *hcon)
86 {
87 return bdaddr_type(hcon->type, hcon->dst_type);
88 }
89
90 /* ---- L2CAP channels ---- */
91
__l2cap_get_chan_by_dcid(struct l2cap_conn * conn,u16 cid)92 static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
93 u16 cid)
94 {
95 struct l2cap_chan *c;
96
97 list_for_each_entry(c, &conn->chan_l, list) {
98 if (c->dcid == cid)
99 return c;
100 }
101 return NULL;
102 }
103
__l2cap_get_chan_by_scid(struct l2cap_conn * conn,u16 cid)104 static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn,
105 u16 cid)
106 {
107 struct l2cap_chan *c;
108
109 list_for_each_entry(c, &conn->chan_l, list) {
110 if (c->scid == cid)
111 return c;
112 }
113 return NULL;
114 }
115
116 /* Find channel with given SCID.
117 * Returns a reference locked channel.
118 */
l2cap_get_chan_by_scid(struct l2cap_conn * conn,u16 cid)119 static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn,
120 u16 cid)
121 {
122 struct l2cap_chan *c;
123
124 mutex_lock(&conn->chan_lock);
125 c = __l2cap_get_chan_by_scid(conn, cid);
126 if (c) {
127 /* Only lock if chan reference is not 0 */
128 c = l2cap_chan_hold_unless_zero(c);
129 if (c)
130 l2cap_chan_lock(c);
131 }
132 mutex_unlock(&conn->chan_lock);
133
134 return c;
135 }
136
137 /* Find channel with given DCID.
138 * Returns a reference locked channel.
139 */
l2cap_get_chan_by_dcid(struct l2cap_conn * conn,u16 cid)140 static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
141 u16 cid)
142 {
143 struct l2cap_chan *c;
144
145 mutex_lock(&conn->chan_lock);
146 c = __l2cap_get_chan_by_dcid(conn, cid);
147 if (c) {
148 /* Only lock if chan reference is not 0 */
149 c = l2cap_chan_hold_unless_zero(c);
150 if (c)
151 l2cap_chan_lock(c);
152 }
153 mutex_unlock(&conn->chan_lock);
154
155 return c;
156 }
157
__l2cap_get_chan_by_ident(struct l2cap_conn * conn,u8 ident)158 static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn,
159 u8 ident)
160 {
161 struct l2cap_chan *c;
162
163 list_for_each_entry(c, &conn->chan_l, list) {
164 if (c->ident == ident)
165 return c;
166 }
167 return NULL;
168 }
169
l2cap_get_chan_by_ident(struct l2cap_conn * conn,u8 ident)170 static struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn,
171 u8 ident)
172 {
173 struct l2cap_chan *c;
174
175 mutex_lock(&conn->chan_lock);
176 c = __l2cap_get_chan_by_ident(conn, ident);
177 if (c) {
178 /* Only lock if chan reference is not 0 */
179 c = l2cap_chan_hold_unless_zero(c);
180 if (c)
181 l2cap_chan_lock(c);
182 }
183 mutex_unlock(&conn->chan_lock);
184
185 return c;
186 }
187
__l2cap_global_chan_by_addr(__le16 psm,bdaddr_t * src,u8 src_type)188 static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src,
189 u8 src_type)
190 {
191 struct l2cap_chan *c;
192
193 list_for_each_entry(c, &chan_list, global_l) {
194 if (src_type == BDADDR_BREDR && c->src_type != BDADDR_BREDR)
195 continue;
196
197 if (src_type != BDADDR_BREDR && c->src_type == BDADDR_BREDR)
198 continue;
199
200 if (c->sport == psm && !bacmp(&c->src, src))
201 return c;
202 }
203 return NULL;
204 }
205
l2cap_add_psm(struct l2cap_chan * chan,bdaddr_t * src,__le16 psm)206 int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm)
207 {
208 int err;
209
210 write_lock(&chan_list_lock);
211
212 if (psm && __l2cap_global_chan_by_addr(psm, src, chan->src_type)) {
213 err = -EADDRINUSE;
214 goto done;
215 }
216
217 if (psm) {
218 chan->psm = psm;
219 chan->sport = psm;
220 err = 0;
221 } else {
222 u16 p, start, end, incr;
223
224 if (chan->src_type == BDADDR_BREDR) {
225 start = L2CAP_PSM_DYN_START;
226 end = L2CAP_PSM_AUTO_END;
227 incr = 2;
228 } else {
229 start = L2CAP_PSM_LE_DYN_START;
230 end = L2CAP_PSM_LE_DYN_END;
231 incr = 1;
232 }
233
234 err = -EINVAL;
235 for (p = start; p <= end; p += incr)
236 if (!__l2cap_global_chan_by_addr(cpu_to_le16(p), src,
237 chan->src_type)) {
238 chan->psm = cpu_to_le16(p);
239 chan->sport = cpu_to_le16(p);
240 err = 0;
241 break;
242 }
243 }
244
245 done:
246 write_unlock(&chan_list_lock);
247 return err;
248 }
249 EXPORT_SYMBOL_GPL(l2cap_add_psm);
250
l2cap_add_scid(struct l2cap_chan * chan,__u16 scid)251 int l2cap_add_scid(struct l2cap_chan *chan, __u16 scid)
252 {
253 write_lock(&chan_list_lock);
254
255 /* Override the defaults (which are for conn-oriented) */
256 chan->omtu = L2CAP_DEFAULT_MTU;
257 chan->chan_type = L2CAP_CHAN_FIXED;
258
259 chan->scid = scid;
260
261 write_unlock(&chan_list_lock);
262
263 return 0;
264 }
265
l2cap_alloc_cid(struct l2cap_conn * conn)266 static u16 l2cap_alloc_cid(struct l2cap_conn *conn)
267 {
268 u16 cid, dyn_end;
269
270 if (conn->hcon->type == LE_LINK)
271 dyn_end = L2CAP_CID_LE_DYN_END;
272 else
273 dyn_end = L2CAP_CID_DYN_END;
274
275 for (cid = L2CAP_CID_DYN_START; cid <= dyn_end; cid++) {
276 if (!__l2cap_get_chan_by_scid(conn, cid))
277 return cid;
278 }
279
280 return 0;
281 }
282
l2cap_state_change(struct l2cap_chan * chan,int state)283 static void l2cap_state_change(struct l2cap_chan *chan, int state)
284 {
285 BT_DBG("chan %p %s -> %s", chan, state_to_string(chan->state),
286 state_to_string(state));
287
288 chan->state = state;
289 chan->ops->state_change(chan, state, 0);
290 }
291
l2cap_state_change_and_error(struct l2cap_chan * chan,int state,int err)292 static inline void l2cap_state_change_and_error(struct l2cap_chan *chan,
293 int state, int err)
294 {
295 chan->state = state;
296 chan->ops->state_change(chan, chan->state, err);
297 }
298
l2cap_chan_set_err(struct l2cap_chan * chan,int err)299 static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
300 {
301 chan->ops->state_change(chan, chan->state, err);
302 }
303
__set_retrans_timer(struct l2cap_chan * chan)304 static void __set_retrans_timer(struct l2cap_chan *chan)
305 {
306 if (!delayed_work_pending(&chan->monitor_timer) &&
307 chan->retrans_timeout) {
308 l2cap_set_timer(chan, &chan->retrans_timer,
309 msecs_to_jiffies(chan->retrans_timeout));
310 }
311 }
312
__set_monitor_timer(struct l2cap_chan * chan)313 static void __set_monitor_timer(struct l2cap_chan *chan)
314 {
315 __clear_retrans_timer(chan);
316 if (chan->monitor_timeout) {
317 l2cap_set_timer(chan, &chan->monitor_timer,
318 msecs_to_jiffies(chan->monitor_timeout));
319 }
320 }
321
l2cap_ertm_seq_in_queue(struct sk_buff_head * head,u16 seq)322 static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head,
323 u16 seq)
324 {
325 struct sk_buff *skb;
326
327 skb_queue_walk(head, skb) {
328 if (bt_cb(skb)->l2cap.txseq == seq)
329 return skb;
330 }
331
332 return NULL;
333 }
334
335 /* ---- L2CAP sequence number lists ---- */
336
337 /* For ERTM, ordered lists of sequence numbers must be tracked for
338 * SREJ requests that are received and for frames that are to be
339 * retransmitted. These seq_list functions implement a singly-linked
340 * list in an array, where membership in the list can also be checked
341 * in constant time. Items can also be added to the tail of the list
342 * and removed from the head in constant time, without further memory
343 * allocs or frees.
344 */
345
l2cap_seq_list_init(struct l2cap_seq_list * seq_list,u16 size)346 static int l2cap_seq_list_init(struct l2cap_seq_list *seq_list, u16 size)
347 {
348 size_t alloc_size, i;
349
350 /* Allocated size is a power of 2 to map sequence numbers
351 * (which may be up to 14 bits) in to a smaller array that is
352 * sized for the negotiated ERTM transmit windows.
353 */
354 alloc_size = roundup_pow_of_two(size);
355
356 seq_list->list = kmalloc_array(alloc_size, sizeof(u16), GFP_KERNEL);
357 if (!seq_list->list)
358 return -ENOMEM;
359
360 seq_list->mask = alloc_size - 1;
361 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
362 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
363 for (i = 0; i < alloc_size; i++)
364 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
365
366 return 0;
367 }
368
l2cap_seq_list_free(struct l2cap_seq_list * seq_list)369 static inline void l2cap_seq_list_free(struct l2cap_seq_list *seq_list)
370 {
371 kfree(seq_list->list);
372 }
373
l2cap_seq_list_contains(struct l2cap_seq_list * seq_list,u16 seq)374 static inline bool l2cap_seq_list_contains(struct l2cap_seq_list *seq_list,
375 u16 seq)
376 {
377 /* Constant-time check for list membership */
378 return seq_list->list[seq & seq_list->mask] != L2CAP_SEQ_LIST_CLEAR;
379 }
380
l2cap_seq_list_pop(struct l2cap_seq_list * seq_list)381 static inline u16 l2cap_seq_list_pop(struct l2cap_seq_list *seq_list)
382 {
383 u16 seq = seq_list->head;
384 u16 mask = seq_list->mask;
385
386 seq_list->head = seq_list->list[seq & mask];
387 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_CLEAR;
388
389 if (seq_list->head == L2CAP_SEQ_LIST_TAIL) {
390 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
391 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
392 }
393
394 return seq;
395 }
396
l2cap_seq_list_clear(struct l2cap_seq_list * seq_list)397 static void l2cap_seq_list_clear(struct l2cap_seq_list *seq_list)
398 {
399 u16 i;
400
401 if (seq_list->head == L2CAP_SEQ_LIST_CLEAR)
402 return;
403
404 for (i = 0; i <= seq_list->mask; i++)
405 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
406
407 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
408 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
409 }
410
l2cap_seq_list_append(struct l2cap_seq_list * seq_list,u16 seq)411 static void l2cap_seq_list_append(struct l2cap_seq_list *seq_list, u16 seq)
412 {
413 u16 mask = seq_list->mask;
414
415 /* All appends happen in constant time */
416
417 if (seq_list->list[seq & mask] != L2CAP_SEQ_LIST_CLEAR)
418 return;
419
420 if (seq_list->tail == L2CAP_SEQ_LIST_CLEAR)
421 seq_list->head = seq;
422 else
423 seq_list->list[seq_list->tail & mask] = seq;
424
425 seq_list->tail = seq;
426 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_TAIL;
427 }
428
l2cap_chan_timeout(struct work_struct * work)429 static void l2cap_chan_timeout(struct work_struct *work)
430 {
431 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
432 chan_timer.work);
433 struct l2cap_conn *conn = chan->conn;
434 int reason;
435
436 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
437
438 if (!conn)
439 return;
440
441 mutex_lock(&conn->chan_lock);
442 /* __set_chan_timer() calls l2cap_chan_hold(chan) while scheduling
443 * this work. No need to call l2cap_chan_hold(chan) here again.
444 */
445 l2cap_chan_lock(chan);
446
447 if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
448 reason = ECONNREFUSED;
449 else if (chan->state == BT_CONNECT &&
450 chan->sec_level != BT_SECURITY_SDP)
451 reason = ECONNREFUSED;
452 else
453 reason = ETIMEDOUT;
454
455 l2cap_chan_close(chan, reason);
456
457 chan->ops->close(chan);
458
459 l2cap_chan_unlock(chan);
460 l2cap_chan_put(chan);
461
462 mutex_unlock(&conn->chan_lock);
463 }
464
l2cap_chan_create(void)465 struct l2cap_chan *l2cap_chan_create(void)
466 {
467 struct l2cap_chan *chan;
468
469 chan = kzalloc(sizeof(*chan), GFP_ATOMIC);
470 if (!chan)
471 return NULL;
472
473 skb_queue_head_init(&chan->tx_q);
474 skb_queue_head_init(&chan->srej_q);
475 mutex_init(&chan->lock);
476
477 /* Set default lock nesting level */
478 atomic_set(&chan->nesting, L2CAP_NESTING_NORMAL);
479
480 write_lock(&chan_list_lock);
481 list_add(&chan->global_l, &chan_list);
482 write_unlock(&chan_list_lock);
483
484 INIT_DELAYED_WORK(&chan->chan_timer, l2cap_chan_timeout);
485 INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout);
486 INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout);
487 INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout);
488
489 chan->state = BT_OPEN;
490
491 kref_init(&chan->kref);
492
493 /* This flag is cleared in l2cap_chan_ready() */
494 set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
495
496 BT_DBG("chan %p", chan);
497
498 return chan;
499 }
500 EXPORT_SYMBOL_GPL(l2cap_chan_create);
501
l2cap_chan_destroy(struct kref * kref)502 static void l2cap_chan_destroy(struct kref *kref)
503 {
504 struct l2cap_chan *chan = container_of(kref, struct l2cap_chan, kref);
505
506 BT_DBG("chan %p", chan);
507
508 write_lock(&chan_list_lock);
509 list_del(&chan->global_l);
510 write_unlock(&chan_list_lock);
511
512 kfree(chan);
513 }
514
l2cap_chan_hold(struct l2cap_chan * c)515 void l2cap_chan_hold(struct l2cap_chan *c)
516 {
517 BT_DBG("chan %p orig refcnt %d", c, kref_read(&c->kref));
518
519 kref_get(&c->kref);
520 }
521
l2cap_chan_hold_unless_zero(struct l2cap_chan * c)522 struct l2cap_chan *l2cap_chan_hold_unless_zero(struct l2cap_chan *c)
523 {
524 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
525
526 if (!kref_get_unless_zero(&c->kref))
527 return NULL;
528
529 return c;
530 }
531
l2cap_chan_put(struct l2cap_chan * c)532 void l2cap_chan_put(struct l2cap_chan *c)
533 {
534 BT_DBG("chan %p orig refcnt %d", c, kref_read(&c->kref));
535
536 kref_put(&c->kref, l2cap_chan_destroy);
537 }
538 EXPORT_SYMBOL_GPL(l2cap_chan_put);
539
l2cap_chan_set_defaults(struct l2cap_chan * chan)540 void l2cap_chan_set_defaults(struct l2cap_chan *chan)
541 {
542 chan->fcs = L2CAP_FCS_CRC16;
543 chan->max_tx = L2CAP_DEFAULT_MAX_TX;
544 chan->tx_win = L2CAP_DEFAULT_TX_WINDOW;
545 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
546 chan->remote_max_tx = chan->max_tx;
547 chan->remote_tx_win = chan->tx_win;
548 chan->ack_win = L2CAP_DEFAULT_TX_WINDOW;
549 chan->sec_level = BT_SECURITY_LOW;
550 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
551 chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO;
552 chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO;
553
554 chan->conf_state = 0;
555 set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
556
557 set_bit(FLAG_FORCE_ACTIVE, &chan->flags);
558 }
559 EXPORT_SYMBOL_GPL(l2cap_chan_set_defaults);
560
l2cap_le_flowctl_init(struct l2cap_chan * chan,u16 tx_credits)561 static void l2cap_le_flowctl_init(struct l2cap_chan *chan, u16 tx_credits)
562 {
563 chan->sdu = NULL;
564 chan->sdu_last_frag = NULL;
565 chan->sdu_len = 0;
566 chan->tx_credits = tx_credits;
567 /* Derive MPS from connection MTU to stop HCI fragmentation */
568 chan->mps = min_t(u16, chan->imtu, chan->conn->mtu - L2CAP_HDR_SIZE);
569 /* Give enough credits for a full packet */
570 chan->rx_credits = (chan->imtu / chan->mps) + 1;
571
572 skb_queue_head_init(&chan->tx_q);
573 }
574
l2cap_ecred_init(struct l2cap_chan * chan,u16 tx_credits)575 static void l2cap_ecred_init(struct l2cap_chan *chan, u16 tx_credits)
576 {
577 l2cap_le_flowctl_init(chan, tx_credits);
578
579 /* L2CAP implementations shall support a minimum MPS of 64 octets */
580 if (chan->mps < L2CAP_ECRED_MIN_MPS) {
581 chan->mps = L2CAP_ECRED_MIN_MPS;
582 chan->rx_credits = (chan->imtu / chan->mps) + 1;
583 }
584 }
585
__l2cap_chan_add(struct l2cap_conn * conn,struct l2cap_chan * chan)586 void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
587 {
588 BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn,
589 __le16_to_cpu(chan->psm), chan->dcid);
590
591 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
592
593 chan->conn = conn;
594
595 switch (chan->chan_type) {
596 case L2CAP_CHAN_CONN_ORIENTED:
597 /* Alloc CID for connection-oriented socket */
598 chan->scid = l2cap_alloc_cid(conn);
599 if (conn->hcon->type == ACL_LINK)
600 chan->omtu = L2CAP_DEFAULT_MTU;
601 break;
602
603 case L2CAP_CHAN_CONN_LESS:
604 /* Connectionless socket */
605 chan->scid = L2CAP_CID_CONN_LESS;
606 chan->dcid = L2CAP_CID_CONN_LESS;
607 chan->omtu = L2CAP_DEFAULT_MTU;
608 break;
609
610 case L2CAP_CHAN_FIXED:
611 /* Caller will set CID and CID specific MTU values */
612 break;
613
614 default:
615 /* Raw socket can send/recv signalling messages only */
616 chan->scid = L2CAP_CID_SIGNALING;
617 chan->dcid = L2CAP_CID_SIGNALING;
618 chan->omtu = L2CAP_DEFAULT_MTU;
619 }
620
621 chan->local_id = L2CAP_BESTEFFORT_ID;
622 chan->local_stype = L2CAP_SERV_BESTEFFORT;
623 chan->local_msdu = L2CAP_DEFAULT_MAX_SDU_SIZE;
624 chan->local_sdu_itime = L2CAP_DEFAULT_SDU_ITIME;
625 chan->local_acc_lat = L2CAP_DEFAULT_ACC_LAT;
626 chan->local_flush_to = L2CAP_EFS_DEFAULT_FLUSH_TO;
627
628 l2cap_chan_hold(chan);
629
630 /* Only keep a reference for fixed channels if they requested it */
631 if (chan->chan_type != L2CAP_CHAN_FIXED ||
632 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
633 hci_conn_hold(conn->hcon);
634
635 list_add(&chan->list, &conn->chan_l);
636 }
637
l2cap_chan_add(struct l2cap_conn * conn,struct l2cap_chan * chan)638 void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
639 {
640 mutex_lock(&conn->chan_lock);
641 __l2cap_chan_add(conn, chan);
642 mutex_unlock(&conn->chan_lock);
643 }
644
l2cap_chan_del(struct l2cap_chan * chan,int err)645 void l2cap_chan_del(struct l2cap_chan *chan, int err)
646 {
647 struct l2cap_conn *conn = chan->conn;
648
649 __clear_chan_timer(chan);
650
651 BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err,
652 state_to_string(chan->state));
653
654 chan->ops->teardown(chan, err);
655
656 if (conn) {
657 struct amp_mgr *mgr = conn->hcon->amp_mgr;
658 /* Delete from channel list */
659 list_del(&chan->list);
660
661 l2cap_chan_put(chan);
662
663 chan->conn = NULL;
664
665 /* Reference was only held for non-fixed channels or
666 * fixed channels that explicitly requested it using the
667 * FLAG_HOLD_HCI_CONN flag.
668 */
669 if (chan->chan_type != L2CAP_CHAN_FIXED ||
670 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
671 hci_conn_drop(conn->hcon);
672
673 if (mgr && mgr->bredr_chan == chan)
674 mgr->bredr_chan = NULL;
675 }
676
677 if (chan->hs_hchan) {
678 struct hci_chan *hs_hchan = chan->hs_hchan;
679
680 BT_DBG("chan %p disconnect hs_hchan %p", chan, hs_hchan);
681 amp_disconnect_logical_link(hs_hchan);
682 }
683
684 if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state))
685 return;
686
687 switch(chan->mode) {
688 case L2CAP_MODE_BASIC:
689 break;
690
691 case L2CAP_MODE_LE_FLOWCTL:
692 case L2CAP_MODE_EXT_FLOWCTL:
693 skb_queue_purge(&chan->tx_q);
694 break;
695
696 case L2CAP_MODE_ERTM:
697 __clear_retrans_timer(chan);
698 __clear_monitor_timer(chan);
699 __clear_ack_timer(chan);
700
701 skb_queue_purge(&chan->srej_q);
702
703 l2cap_seq_list_free(&chan->srej_list);
704 l2cap_seq_list_free(&chan->retrans_list);
705 fallthrough;
706
707 case L2CAP_MODE_STREAMING:
708 skb_queue_purge(&chan->tx_q);
709 break;
710 }
711
712 return;
713 }
714 EXPORT_SYMBOL_GPL(l2cap_chan_del);
715
__l2cap_chan_list_id(struct l2cap_conn * conn,u16 id,l2cap_chan_func_t func,void * data)716 static void __l2cap_chan_list_id(struct l2cap_conn *conn, u16 id,
717 l2cap_chan_func_t func, void *data)
718 {
719 struct l2cap_chan *chan, *l;
720
721 list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
722 if (chan->ident == id)
723 func(chan, data);
724 }
725 }
726
__l2cap_chan_list(struct l2cap_conn * conn,l2cap_chan_func_t func,void * data)727 static void __l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
728 void *data)
729 {
730 struct l2cap_chan *chan;
731
732 list_for_each_entry(chan, &conn->chan_l, list) {
733 func(chan, data);
734 }
735 }
736
l2cap_chan_list(struct l2cap_conn * conn,l2cap_chan_func_t func,void * data)737 void l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
738 void *data)
739 {
740 if (!conn)
741 return;
742
743 mutex_lock(&conn->chan_lock);
744 __l2cap_chan_list(conn, func, data);
745 mutex_unlock(&conn->chan_lock);
746 }
747
748 EXPORT_SYMBOL_GPL(l2cap_chan_list);
749
l2cap_conn_update_id_addr(struct work_struct * work)750 static void l2cap_conn_update_id_addr(struct work_struct *work)
751 {
752 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
753 id_addr_update_work);
754 struct hci_conn *hcon = conn->hcon;
755 struct l2cap_chan *chan;
756
757 mutex_lock(&conn->chan_lock);
758
759 list_for_each_entry(chan, &conn->chan_l, list) {
760 l2cap_chan_lock(chan);
761 bacpy(&chan->dst, &hcon->dst);
762 chan->dst_type = bdaddr_dst_type(hcon);
763 l2cap_chan_unlock(chan);
764 }
765
766 mutex_unlock(&conn->chan_lock);
767 }
768
l2cap_chan_le_connect_reject(struct l2cap_chan * chan)769 static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan)
770 {
771 struct l2cap_conn *conn = chan->conn;
772 struct l2cap_le_conn_rsp rsp;
773 u16 result;
774
775 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
776 result = L2CAP_CR_LE_AUTHORIZATION;
777 else
778 result = L2CAP_CR_LE_BAD_PSM;
779
780 l2cap_state_change(chan, BT_DISCONN);
781
782 rsp.dcid = cpu_to_le16(chan->scid);
783 rsp.mtu = cpu_to_le16(chan->imtu);
784 rsp.mps = cpu_to_le16(chan->mps);
785 rsp.credits = cpu_to_le16(chan->rx_credits);
786 rsp.result = cpu_to_le16(result);
787
788 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
789 &rsp);
790 }
791
l2cap_chan_ecred_connect_reject(struct l2cap_chan * chan)792 static void l2cap_chan_ecred_connect_reject(struct l2cap_chan *chan)
793 {
794 l2cap_state_change(chan, BT_DISCONN);
795
796 __l2cap_ecred_conn_rsp_defer(chan);
797 }
798
l2cap_chan_connect_reject(struct l2cap_chan * chan)799 static void l2cap_chan_connect_reject(struct l2cap_chan *chan)
800 {
801 struct l2cap_conn *conn = chan->conn;
802 struct l2cap_conn_rsp rsp;
803 u16 result;
804
805 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
806 result = L2CAP_CR_SEC_BLOCK;
807 else
808 result = L2CAP_CR_BAD_PSM;
809
810 l2cap_state_change(chan, BT_DISCONN);
811
812 rsp.scid = cpu_to_le16(chan->dcid);
813 rsp.dcid = cpu_to_le16(chan->scid);
814 rsp.result = cpu_to_le16(result);
815 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
816
817 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, sizeof(rsp), &rsp);
818 }
819
l2cap_chan_close(struct l2cap_chan * chan,int reason)820 void l2cap_chan_close(struct l2cap_chan *chan, int reason)
821 {
822 struct l2cap_conn *conn = chan->conn;
823
824 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
825
826 switch (chan->state) {
827 case BT_LISTEN:
828 chan->ops->teardown(chan, 0);
829 break;
830
831 case BT_CONNECTED:
832 case BT_CONFIG:
833 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
834 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
835 l2cap_send_disconn_req(chan, reason);
836 } else
837 l2cap_chan_del(chan, reason);
838 break;
839
840 case BT_CONNECT2:
841 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
842 if (conn->hcon->type == ACL_LINK)
843 l2cap_chan_connect_reject(chan);
844 else if (conn->hcon->type == LE_LINK) {
845 switch (chan->mode) {
846 case L2CAP_MODE_LE_FLOWCTL:
847 l2cap_chan_le_connect_reject(chan);
848 break;
849 case L2CAP_MODE_EXT_FLOWCTL:
850 l2cap_chan_ecred_connect_reject(chan);
851 return;
852 }
853 }
854 }
855
856 l2cap_chan_del(chan, reason);
857 break;
858
859 case BT_CONNECT:
860 case BT_DISCONN:
861 l2cap_chan_del(chan, reason);
862 break;
863
864 default:
865 chan->ops->teardown(chan, 0);
866 break;
867 }
868 }
869 EXPORT_SYMBOL(l2cap_chan_close);
870
l2cap_get_auth_type(struct l2cap_chan * chan)871 static inline u8 l2cap_get_auth_type(struct l2cap_chan *chan)
872 {
873 switch (chan->chan_type) {
874 case L2CAP_CHAN_RAW:
875 switch (chan->sec_level) {
876 case BT_SECURITY_HIGH:
877 case BT_SECURITY_FIPS:
878 return HCI_AT_DEDICATED_BONDING_MITM;
879 case BT_SECURITY_MEDIUM:
880 return HCI_AT_DEDICATED_BONDING;
881 default:
882 return HCI_AT_NO_BONDING;
883 }
884 break;
885 case L2CAP_CHAN_CONN_LESS:
886 if (chan->psm == cpu_to_le16(L2CAP_PSM_3DSP)) {
887 if (chan->sec_level == BT_SECURITY_LOW)
888 chan->sec_level = BT_SECURITY_SDP;
889 }
890 if (chan->sec_level == BT_SECURITY_HIGH ||
891 chan->sec_level == BT_SECURITY_FIPS)
892 return HCI_AT_NO_BONDING_MITM;
893 else
894 return HCI_AT_NO_BONDING;
895 break;
896 case L2CAP_CHAN_CONN_ORIENTED:
897 if (chan->psm == cpu_to_le16(L2CAP_PSM_SDP)) {
898 if (chan->sec_level == BT_SECURITY_LOW)
899 chan->sec_level = BT_SECURITY_SDP;
900
901 if (chan->sec_level == BT_SECURITY_HIGH ||
902 chan->sec_level == BT_SECURITY_FIPS)
903 return HCI_AT_NO_BONDING_MITM;
904 else
905 return HCI_AT_NO_BONDING;
906 }
907 fallthrough;
908
909 default:
910 switch (chan->sec_level) {
911 case BT_SECURITY_HIGH:
912 case BT_SECURITY_FIPS:
913 return HCI_AT_GENERAL_BONDING_MITM;
914 case BT_SECURITY_MEDIUM:
915 return HCI_AT_GENERAL_BONDING;
916 default:
917 return HCI_AT_NO_BONDING;
918 }
919 break;
920 }
921 }
922
923 /* Service level security */
l2cap_chan_check_security(struct l2cap_chan * chan,bool initiator)924 int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator)
925 {
926 struct l2cap_conn *conn = chan->conn;
927 __u8 auth_type;
928
929 if (conn->hcon->type == LE_LINK)
930 return smp_conn_security(conn->hcon, chan->sec_level);
931
932 auth_type = l2cap_get_auth_type(chan);
933
934 return hci_conn_security(conn->hcon, chan->sec_level, auth_type,
935 initiator);
936 }
937
l2cap_get_ident(struct l2cap_conn * conn)938 static u8 l2cap_get_ident(struct l2cap_conn *conn)
939 {
940 u8 id;
941
942 /* Get next available identificator.
943 * 1 - 128 are used by kernel.
944 * 129 - 199 are reserved.
945 * 200 - 254 are used by utilities like l2ping, etc.
946 */
947
948 mutex_lock(&conn->ident_lock);
949
950 if (++conn->tx_ident > 128)
951 conn->tx_ident = 1;
952
953 id = conn->tx_ident;
954
955 mutex_unlock(&conn->ident_lock);
956
957 return id;
958 }
959
l2cap_send_cmd(struct l2cap_conn * conn,u8 ident,u8 code,u16 len,void * data)960 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
961 void *data)
962 {
963 struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data);
964 u8 flags;
965
966 BT_DBG("code 0x%2.2x", code);
967
968 if (!skb)
969 return;
970
971 /* Use NO_FLUSH if supported or we have an LE link (which does
972 * not support auto-flushing packets) */
973 if (lmp_no_flush_capable(conn->hcon->hdev) ||
974 conn->hcon->type == LE_LINK)
975 flags = ACL_START_NO_FLUSH;
976 else
977 flags = ACL_START;
978
979 bt_cb(skb)->force_active = BT_POWER_FORCE_ACTIVE_ON;
980 skb->priority = HCI_PRIO_MAX;
981
982 hci_send_acl(conn->hchan, skb, flags);
983 }
984
__chan_is_moving(struct l2cap_chan * chan)985 static bool __chan_is_moving(struct l2cap_chan *chan)
986 {
987 return chan->move_state != L2CAP_MOVE_STABLE &&
988 chan->move_state != L2CAP_MOVE_WAIT_PREPARE;
989 }
990
l2cap_do_send(struct l2cap_chan * chan,struct sk_buff * skb)991 static void l2cap_do_send(struct l2cap_chan *chan, struct sk_buff *skb)
992 {
993 struct hci_conn *hcon = chan->conn->hcon;
994 u16 flags;
995
996 BT_DBG("chan %p, skb %p len %d priority %u", chan, skb, skb->len,
997 skb->priority);
998
999 if (chan->hs_hcon && !__chan_is_moving(chan)) {
1000 if (chan->hs_hchan)
1001 hci_send_acl(chan->hs_hchan, skb, ACL_COMPLETE);
1002 else
1003 kfree_skb(skb);
1004
1005 return;
1006 }
1007
1008 /* Use NO_FLUSH for LE links (where this is the only option) or
1009 * if the BR/EDR link supports it and flushing has not been
1010 * explicitly requested (through FLAG_FLUSHABLE).
1011 */
1012 if (hcon->type == LE_LINK ||
1013 (!test_bit(FLAG_FLUSHABLE, &chan->flags) &&
1014 lmp_no_flush_capable(hcon->hdev)))
1015 flags = ACL_START_NO_FLUSH;
1016 else
1017 flags = ACL_START;
1018
1019 bt_cb(skb)->force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags);
1020 hci_send_acl(chan->conn->hchan, skb, flags);
1021 }
1022
__unpack_enhanced_control(u16 enh,struct l2cap_ctrl * control)1023 static void __unpack_enhanced_control(u16 enh, struct l2cap_ctrl *control)
1024 {
1025 control->reqseq = (enh & L2CAP_CTRL_REQSEQ) >> L2CAP_CTRL_REQSEQ_SHIFT;
1026 control->final = (enh & L2CAP_CTRL_FINAL) >> L2CAP_CTRL_FINAL_SHIFT;
1027
1028 if (enh & L2CAP_CTRL_FRAME_TYPE) {
1029 /* S-Frame */
1030 control->sframe = 1;
1031 control->poll = (enh & L2CAP_CTRL_POLL) >> L2CAP_CTRL_POLL_SHIFT;
1032 control->super = (enh & L2CAP_CTRL_SUPERVISE) >> L2CAP_CTRL_SUPER_SHIFT;
1033
1034 control->sar = 0;
1035 control->txseq = 0;
1036 } else {
1037 /* I-Frame */
1038 control->sframe = 0;
1039 control->sar = (enh & L2CAP_CTRL_SAR) >> L2CAP_CTRL_SAR_SHIFT;
1040 control->txseq = (enh & L2CAP_CTRL_TXSEQ) >> L2CAP_CTRL_TXSEQ_SHIFT;
1041
1042 control->poll = 0;
1043 control->super = 0;
1044 }
1045 }
1046
__unpack_extended_control(u32 ext,struct l2cap_ctrl * control)1047 static void __unpack_extended_control(u32 ext, struct l2cap_ctrl *control)
1048 {
1049 control->reqseq = (ext & L2CAP_EXT_CTRL_REQSEQ) >> L2CAP_EXT_CTRL_REQSEQ_SHIFT;
1050 control->final = (ext & L2CAP_EXT_CTRL_FINAL) >> L2CAP_EXT_CTRL_FINAL_SHIFT;
1051
1052 if (ext & L2CAP_EXT_CTRL_FRAME_TYPE) {
1053 /* S-Frame */
1054 control->sframe = 1;
1055 control->poll = (ext & L2CAP_EXT_CTRL_POLL) >> L2CAP_EXT_CTRL_POLL_SHIFT;
1056 control->super = (ext & L2CAP_EXT_CTRL_SUPERVISE) >> L2CAP_EXT_CTRL_SUPER_SHIFT;
1057
1058 control->sar = 0;
1059 control->txseq = 0;
1060 } else {
1061 /* I-Frame */
1062 control->sframe = 0;
1063 control->sar = (ext & L2CAP_EXT_CTRL_SAR) >> L2CAP_EXT_CTRL_SAR_SHIFT;
1064 control->txseq = (ext & L2CAP_EXT_CTRL_TXSEQ) >> L2CAP_EXT_CTRL_TXSEQ_SHIFT;
1065
1066 control->poll = 0;
1067 control->super = 0;
1068 }
1069 }
1070
__unpack_control(struct l2cap_chan * chan,struct sk_buff * skb)1071 static inline void __unpack_control(struct l2cap_chan *chan,
1072 struct sk_buff *skb)
1073 {
1074 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
1075 __unpack_extended_control(get_unaligned_le32(skb->data),
1076 &bt_cb(skb)->l2cap);
1077 skb_pull(skb, L2CAP_EXT_CTRL_SIZE);
1078 } else {
1079 __unpack_enhanced_control(get_unaligned_le16(skb->data),
1080 &bt_cb(skb)->l2cap);
1081 skb_pull(skb, L2CAP_ENH_CTRL_SIZE);
1082 }
1083 }
1084
__pack_extended_control(struct l2cap_ctrl * control)1085 static u32 __pack_extended_control(struct l2cap_ctrl *control)
1086 {
1087 u32 packed;
1088
1089 packed = control->reqseq << L2CAP_EXT_CTRL_REQSEQ_SHIFT;
1090 packed |= control->final << L2CAP_EXT_CTRL_FINAL_SHIFT;
1091
1092 if (control->sframe) {
1093 packed |= control->poll << L2CAP_EXT_CTRL_POLL_SHIFT;
1094 packed |= control->super << L2CAP_EXT_CTRL_SUPER_SHIFT;
1095 packed |= L2CAP_EXT_CTRL_FRAME_TYPE;
1096 } else {
1097 packed |= control->sar << L2CAP_EXT_CTRL_SAR_SHIFT;
1098 packed |= control->txseq << L2CAP_EXT_CTRL_TXSEQ_SHIFT;
1099 }
1100
1101 return packed;
1102 }
1103
__pack_enhanced_control(struct l2cap_ctrl * control)1104 static u16 __pack_enhanced_control(struct l2cap_ctrl *control)
1105 {
1106 u16 packed;
1107
1108 packed = control->reqseq << L2CAP_CTRL_REQSEQ_SHIFT;
1109 packed |= control->final << L2CAP_CTRL_FINAL_SHIFT;
1110
1111 if (control->sframe) {
1112 packed |= control->poll << L2CAP_CTRL_POLL_SHIFT;
1113 packed |= control->super << L2CAP_CTRL_SUPER_SHIFT;
1114 packed |= L2CAP_CTRL_FRAME_TYPE;
1115 } else {
1116 packed |= control->sar << L2CAP_CTRL_SAR_SHIFT;
1117 packed |= control->txseq << L2CAP_CTRL_TXSEQ_SHIFT;
1118 }
1119
1120 return packed;
1121 }
1122
__pack_control(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb)1123 static inline void __pack_control(struct l2cap_chan *chan,
1124 struct l2cap_ctrl *control,
1125 struct sk_buff *skb)
1126 {
1127 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
1128 put_unaligned_le32(__pack_extended_control(control),
1129 skb->data + L2CAP_HDR_SIZE);
1130 } else {
1131 put_unaligned_le16(__pack_enhanced_control(control),
1132 skb->data + L2CAP_HDR_SIZE);
1133 }
1134 }
1135
__ertm_hdr_size(struct l2cap_chan * chan)1136 static inline unsigned int __ertm_hdr_size(struct l2cap_chan *chan)
1137 {
1138 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1139 return L2CAP_EXT_HDR_SIZE;
1140 else
1141 return L2CAP_ENH_HDR_SIZE;
1142 }
1143
l2cap_create_sframe_pdu(struct l2cap_chan * chan,u32 control)1144 static struct sk_buff *l2cap_create_sframe_pdu(struct l2cap_chan *chan,
1145 u32 control)
1146 {
1147 struct sk_buff *skb;
1148 struct l2cap_hdr *lh;
1149 int hlen = __ertm_hdr_size(chan);
1150
1151 if (chan->fcs == L2CAP_FCS_CRC16)
1152 hlen += L2CAP_FCS_SIZE;
1153
1154 skb = bt_skb_alloc(hlen, GFP_KERNEL);
1155
1156 if (!skb)
1157 return ERR_PTR(-ENOMEM);
1158
1159 lh = skb_put(skb, L2CAP_HDR_SIZE);
1160 lh->len = cpu_to_le16(hlen - L2CAP_HDR_SIZE);
1161 lh->cid = cpu_to_le16(chan->dcid);
1162
1163 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1164 put_unaligned_le32(control, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
1165 else
1166 put_unaligned_le16(control, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
1167
1168 if (chan->fcs == L2CAP_FCS_CRC16) {
1169 u16 fcs = crc16(0, (u8 *)skb->data, skb->len);
1170 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1171 }
1172
1173 skb->priority = HCI_PRIO_MAX;
1174 return skb;
1175 }
1176
l2cap_send_sframe(struct l2cap_chan * chan,struct l2cap_ctrl * control)1177 static void l2cap_send_sframe(struct l2cap_chan *chan,
1178 struct l2cap_ctrl *control)
1179 {
1180 struct sk_buff *skb;
1181 u32 control_field;
1182
1183 BT_DBG("chan %p, control %p", chan, control);
1184
1185 if (!control->sframe)
1186 return;
1187
1188 if (__chan_is_moving(chan))
1189 return;
1190
1191 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state) &&
1192 !control->poll)
1193 control->final = 1;
1194
1195 if (control->super == L2CAP_SUPER_RR)
1196 clear_bit(CONN_RNR_SENT, &chan->conn_state);
1197 else if (control->super == L2CAP_SUPER_RNR)
1198 set_bit(CONN_RNR_SENT, &chan->conn_state);
1199
1200 if (control->super != L2CAP_SUPER_SREJ) {
1201 chan->last_acked_seq = control->reqseq;
1202 __clear_ack_timer(chan);
1203 }
1204
1205 BT_DBG("reqseq %d, final %d, poll %d, super %d", control->reqseq,
1206 control->final, control->poll, control->super);
1207
1208 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1209 control_field = __pack_extended_control(control);
1210 else
1211 control_field = __pack_enhanced_control(control);
1212
1213 skb = l2cap_create_sframe_pdu(chan, control_field);
1214 if (!IS_ERR(skb))
1215 l2cap_do_send(chan, skb);
1216 }
1217
l2cap_send_rr_or_rnr(struct l2cap_chan * chan,bool poll)1218 static void l2cap_send_rr_or_rnr(struct l2cap_chan *chan, bool poll)
1219 {
1220 struct l2cap_ctrl control;
1221
1222 BT_DBG("chan %p, poll %d", chan, poll);
1223
1224 memset(&control, 0, sizeof(control));
1225 control.sframe = 1;
1226 control.poll = poll;
1227
1228 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
1229 control.super = L2CAP_SUPER_RNR;
1230 else
1231 control.super = L2CAP_SUPER_RR;
1232
1233 control.reqseq = chan->buffer_seq;
1234 l2cap_send_sframe(chan, &control);
1235 }
1236
__l2cap_no_conn_pending(struct l2cap_chan * chan)1237 static inline int __l2cap_no_conn_pending(struct l2cap_chan *chan)
1238 {
1239 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
1240 return true;
1241
1242 return !test_bit(CONF_CONNECT_PEND, &chan->conf_state);
1243 }
1244
__amp_capable(struct l2cap_chan * chan)1245 static bool __amp_capable(struct l2cap_chan *chan)
1246 {
1247 struct l2cap_conn *conn = chan->conn;
1248 struct hci_dev *hdev;
1249 bool amp_available = false;
1250
1251 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
1252 return false;
1253
1254 if (!(conn->remote_fixed_chan & L2CAP_FC_A2MP))
1255 return false;
1256
1257 read_lock(&hci_dev_list_lock);
1258 list_for_each_entry(hdev, &hci_dev_list, list) {
1259 if (hdev->amp_type != AMP_TYPE_BREDR &&
1260 test_bit(HCI_UP, &hdev->flags)) {
1261 amp_available = true;
1262 break;
1263 }
1264 }
1265 read_unlock(&hci_dev_list_lock);
1266
1267 if (chan->chan_policy == BT_CHANNEL_POLICY_AMP_PREFERRED)
1268 return amp_available;
1269
1270 return false;
1271 }
1272
l2cap_check_efs(struct l2cap_chan * chan)1273 static bool l2cap_check_efs(struct l2cap_chan *chan)
1274 {
1275 /* Check EFS parameters */
1276 return true;
1277 }
1278
l2cap_send_conn_req(struct l2cap_chan * chan)1279 void l2cap_send_conn_req(struct l2cap_chan *chan)
1280 {
1281 struct l2cap_conn *conn = chan->conn;
1282 struct l2cap_conn_req req;
1283
1284 req.scid = cpu_to_le16(chan->scid);
1285 req.psm = chan->psm;
1286
1287 chan->ident = l2cap_get_ident(conn);
1288
1289 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
1290
1291 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_REQ, sizeof(req), &req);
1292 }
1293
l2cap_send_create_chan_req(struct l2cap_chan * chan,u8 amp_id)1294 static void l2cap_send_create_chan_req(struct l2cap_chan *chan, u8 amp_id)
1295 {
1296 struct l2cap_create_chan_req req;
1297 req.scid = cpu_to_le16(chan->scid);
1298 req.psm = chan->psm;
1299 req.amp_id = amp_id;
1300
1301 chan->ident = l2cap_get_ident(chan->conn);
1302
1303 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_REQ,
1304 sizeof(req), &req);
1305 }
1306
l2cap_move_setup(struct l2cap_chan * chan)1307 static void l2cap_move_setup(struct l2cap_chan *chan)
1308 {
1309 struct sk_buff *skb;
1310
1311 BT_DBG("chan %p", chan);
1312
1313 if (chan->mode != L2CAP_MODE_ERTM)
1314 return;
1315
1316 __clear_retrans_timer(chan);
1317 __clear_monitor_timer(chan);
1318 __clear_ack_timer(chan);
1319
1320 chan->retry_count = 0;
1321 skb_queue_walk(&chan->tx_q, skb) {
1322 if (bt_cb(skb)->l2cap.retries)
1323 bt_cb(skb)->l2cap.retries = 1;
1324 else
1325 break;
1326 }
1327
1328 chan->expected_tx_seq = chan->buffer_seq;
1329
1330 clear_bit(CONN_REJ_ACT, &chan->conn_state);
1331 clear_bit(CONN_SREJ_ACT, &chan->conn_state);
1332 l2cap_seq_list_clear(&chan->retrans_list);
1333 l2cap_seq_list_clear(&chan->srej_list);
1334 skb_queue_purge(&chan->srej_q);
1335
1336 chan->tx_state = L2CAP_TX_STATE_XMIT;
1337 chan->rx_state = L2CAP_RX_STATE_MOVE;
1338
1339 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
1340 }
1341
l2cap_move_done(struct l2cap_chan * chan)1342 static void l2cap_move_done(struct l2cap_chan *chan)
1343 {
1344 u8 move_role = chan->move_role;
1345 BT_DBG("chan %p", chan);
1346
1347 chan->move_state = L2CAP_MOVE_STABLE;
1348 chan->move_role = L2CAP_MOVE_ROLE_NONE;
1349
1350 if (chan->mode != L2CAP_MODE_ERTM)
1351 return;
1352
1353 switch (move_role) {
1354 case L2CAP_MOVE_ROLE_INITIATOR:
1355 l2cap_tx(chan, NULL, NULL, L2CAP_EV_EXPLICIT_POLL);
1356 chan->rx_state = L2CAP_RX_STATE_WAIT_F;
1357 break;
1358 case L2CAP_MOVE_ROLE_RESPONDER:
1359 chan->rx_state = L2CAP_RX_STATE_WAIT_P;
1360 break;
1361 }
1362 }
1363
l2cap_chan_ready(struct l2cap_chan * chan)1364 static void l2cap_chan_ready(struct l2cap_chan *chan)
1365 {
1366 /* The channel may have already been flagged as connected in
1367 * case of receiving data before the L2CAP info req/rsp
1368 * procedure is complete.
1369 */
1370 if (chan->state == BT_CONNECTED)
1371 return;
1372
1373 /* This clears all conf flags, including CONF_NOT_COMPLETE */
1374 chan->conf_state = 0;
1375 __clear_chan_timer(chan);
1376
1377 switch (chan->mode) {
1378 case L2CAP_MODE_LE_FLOWCTL:
1379 case L2CAP_MODE_EXT_FLOWCTL:
1380 if (!chan->tx_credits)
1381 chan->ops->suspend(chan);
1382 break;
1383 }
1384
1385 chan->state = BT_CONNECTED;
1386
1387 chan->ops->ready(chan);
1388 }
1389
l2cap_le_connect(struct l2cap_chan * chan)1390 static void l2cap_le_connect(struct l2cap_chan *chan)
1391 {
1392 struct l2cap_conn *conn = chan->conn;
1393 struct l2cap_le_conn_req req;
1394
1395 if (test_and_set_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags))
1396 return;
1397
1398 if (!chan->imtu)
1399 chan->imtu = chan->conn->mtu;
1400
1401 l2cap_le_flowctl_init(chan, 0);
1402
1403 req.psm = chan->psm;
1404 req.scid = cpu_to_le16(chan->scid);
1405 req.mtu = cpu_to_le16(chan->imtu);
1406 req.mps = cpu_to_le16(chan->mps);
1407 req.credits = cpu_to_le16(chan->rx_credits);
1408
1409 chan->ident = l2cap_get_ident(conn);
1410
1411 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_REQ,
1412 sizeof(req), &req);
1413 }
1414
1415 struct l2cap_ecred_conn_data {
1416 struct {
1417 struct l2cap_ecred_conn_req req;
1418 __le16 scid[5];
1419 } __packed pdu;
1420 struct l2cap_chan *chan;
1421 struct pid *pid;
1422 int count;
1423 };
1424
l2cap_ecred_defer_connect(struct l2cap_chan * chan,void * data)1425 static void l2cap_ecred_defer_connect(struct l2cap_chan *chan, void *data)
1426 {
1427 struct l2cap_ecred_conn_data *conn = data;
1428 struct pid *pid;
1429
1430 if (chan == conn->chan)
1431 return;
1432
1433 if (!test_and_clear_bit(FLAG_DEFER_SETUP, &chan->flags))
1434 return;
1435
1436 pid = chan->ops->get_peer_pid(chan);
1437
1438 /* Only add deferred channels with the same PID/PSM */
1439 if (conn->pid != pid || chan->psm != conn->chan->psm || chan->ident ||
1440 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
1441 return;
1442
1443 if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
1444 return;
1445
1446 l2cap_ecred_init(chan, 0);
1447
1448 /* Set the same ident so we can match on the rsp */
1449 chan->ident = conn->chan->ident;
1450
1451 /* Include all channels deferred */
1452 conn->pdu.scid[conn->count] = cpu_to_le16(chan->scid);
1453
1454 conn->count++;
1455 }
1456
l2cap_ecred_connect(struct l2cap_chan * chan)1457 static void l2cap_ecred_connect(struct l2cap_chan *chan)
1458 {
1459 struct l2cap_conn *conn = chan->conn;
1460 struct l2cap_ecred_conn_data data;
1461
1462 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
1463 return;
1464
1465 if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
1466 return;
1467
1468 l2cap_ecred_init(chan, 0);
1469
1470 memset(&data, 0, sizeof(data));
1471 data.pdu.req.psm = chan->psm;
1472 data.pdu.req.mtu = cpu_to_le16(chan->imtu);
1473 data.pdu.req.mps = cpu_to_le16(chan->mps);
1474 data.pdu.req.credits = cpu_to_le16(chan->rx_credits);
1475 data.pdu.scid[0] = cpu_to_le16(chan->scid);
1476
1477 chan->ident = l2cap_get_ident(conn);
1478 data.pid = chan->ops->get_peer_pid(chan);
1479
1480 data.count = 1;
1481 data.chan = chan;
1482 data.pid = chan->ops->get_peer_pid(chan);
1483
1484 __l2cap_chan_list(conn, l2cap_ecred_defer_connect, &data);
1485
1486 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_CONN_REQ,
1487 sizeof(data.pdu.req) + data.count * sizeof(__le16),
1488 &data.pdu);
1489 }
1490
l2cap_le_start(struct l2cap_chan * chan)1491 static void l2cap_le_start(struct l2cap_chan *chan)
1492 {
1493 struct l2cap_conn *conn = chan->conn;
1494
1495 if (!smp_conn_security(conn->hcon, chan->sec_level))
1496 return;
1497
1498 if (!chan->psm) {
1499 l2cap_chan_ready(chan);
1500 return;
1501 }
1502
1503 if (chan->state == BT_CONNECT) {
1504 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL)
1505 l2cap_ecred_connect(chan);
1506 else
1507 l2cap_le_connect(chan);
1508 }
1509 }
1510
l2cap_start_connection(struct l2cap_chan * chan)1511 static void l2cap_start_connection(struct l2cap_chan *chan)
1512 {
1513 if (__amp_capable(chan)) {
1514 BT_DBG("chan %p AMP capable: discover AMPs", chan);
1515 a2mp_discover_amp(chan);
1516 } else if (chan->conn->hcon->type == LE_LINK) {
1517 l2cap_le_start(chan);
1518 } else {
1519 l2cap_send_conn_req(chan);
1520 }
1521 }
1522
l2cap_request_info(struct l2cap_conn * conn)1523 static void l2cap_request_info(struct l2cap_conn *conn)
1524 {
1525 struct l2cap_info_req req;
1526
1527 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1528 return;
1529
1530 req.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
1531
1532 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
1533 conn->info_ident = l2cap_get_ident(conn);
1534
1535 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
1536
1537 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
1538 sizeof(req), &req);
1539 }
1540
l2cap_check_enc_key_size(struct hci_conn * hcon)1541 static bool l2cap_check_enc_key_size(struct hci_conn *hcon)
1542 {
1543 /* The minimum encryption key size needs to be enforced by the
1544 * host stack before establishing any L2CAP connections. The
1545 * specification in theory allows a minimum of 1, but to align
1546 * BR/EDR and LE transports, a minimum of 7 is chosen.
1547 *
1548 * This check might also be called for unencrypted connections
1549 * that have no key size requirements. Ensure that the link is
1550 * actually encrypted before enforcing a key size.
1551 */
1552 return (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags) ||
1553 hcon->enc_key_size >= hcon->hdev->min_enc_key_size);
1554 }
1555
l2cap_do_start(struct l2cap_chan * chan)1556 static void l2cap_do_start(struct l2cap_chan *chan)
1557 {
1558 struct l2cap_conn *conn = chan->conn;
1559
1560 if (conn->hcon->type == LE_LINK) {
1561 l2cap_le_start(chan);
1562 return;
1563 }
1564
1565 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)) {
1566 l2cap_request_info(conn);
1567 return;
1568 }
1569
1570 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE))
1571 return;
1572
1573 if (!l2cap_chan_check_security(chan, true) ||
1574 !__l2cap_no_conn_pending(chan))
1575 return;
1576
1577 if (l2cap_check_enc_key_size(conn->hcon))
1578 l2cap_start_connection(chan);
1579 else
1580 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
1581 }
1582
l2cap_mode_supported(__u8 mode,__u32 feat_mask)1583 static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
1584 {
1585 u32 local_feat_mask = l2cap_feat_mask;
1586 if (!disable_ertm)
1587 local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
1588
1589 switch (mode) {
1590 case L2CAP_MODE_ERTM:
1591 return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
1592 case L2CAP_MODE_STREAMING:
1593 return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
1594 default:
1595 return 0x00;
1596 }
1597 }
1598
l2cap_send_disconn_req(struct l2cap_chan * chan,int err)1599 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err)
1600 {
1601 struct l2cap_conn *conn = chan->conn;
1602 struct l2cap_disconn_req req;
1603
1604 if (!conn)
1605 return;
1606
1607 if (chan->mode == L2CAP_MODE_ERTM && chan->state == BT_CONNECTED) {
1608 __clear_retrans_timer(chan);
1609 __clear_monitor_timer(chan);
1610 __clear_ack_timer(chan);
1611 }
1612
1613 if (chan->scid == L2CAP_CID_A2MP) {
1614 l2cap_state_change(chan, BT_DISCONN);
1615 return;
1616 }
1617
1618 req.dcid = cpu_to_le16(chan->dcid);
1619 req.scid = cpu_to_le16(chan->scid);
1620 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_DISCONN_REQ,
1621 sizeof(req), &req);
1622
1623 l2cap_state_change_and_error(chan, BT_DISCONN, err);
1624 }
1625
1626 /* ---- L2CAP connections ---- */
l2cap_conn_start(struct l2cap_conn * conn)1627 static void l2cap_conn_start(struct l2cap_conn *conn)
1628 {
1629 struct l2cap_chan *chan, *tmp;
1630
1631 BT_DBG("conn %p", conn);
1632
1633 mutex_lock(&conn->chan_lock);
1634
1635 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
1636 l2cap_chan_lock(chan);
1637
1638 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1639 l2cap_chan_ready(chan);
1640 l2cap_chan_unlock(chan);
1641 continue;
1642 }
1643
1644 if (chan->state == BT_CONNECT) {
1645 if (!l2cap_chan_check_security(chan, true) ||
1646 !__l2cap_no_conn_pending(chan)) {
1647 l2cap_chan_unlock(chan);
1648 continue;
1649 }
1650
1651 if (!l2cap_mode_supported(chan->mode, conn->feat_mask)
1652 && test_bit(CONF_STATE2_DEVICE,
1653 &chan->conf_state)) {
1654 l2cap_chan_close(chan, ECONNRESET);
1655 l2cap_chan_unlock(chan);
1656 continue;
1657 }
1658
1659 if (l2cap_check_enc_key_size(conn->hcon))
1660 l2cap_start_connection(chan);
1661 else
1662 l2cap_chan_close(chan, ECONNREFUSED);
1663
1664 } else if (chan->state == BT_CONNECT2) {
1665 struct l2cap_conn_rsp rsp;
1666 char buf[128];
1667 rsp.scid = cpu_to_le16(chan->dcid);
1668 rsp.dcid = cpu_to_le16(chan->scid);
1669
1670 if (l2cap_chan_check_security(chan, false)) {
1671 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
1672 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1673 rsp.status = cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
1674 chan->ops->defer(chan);
1675
1676 } else {
1677 l2cap_state_change(chan, BT_CONFIG);
1678 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
1679 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
1680 }
1681 } else {
1682 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1683 rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
1684 }
1685
1686 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
1687 sizeof(rsp), &rsp);
1688
1689 if (test_bit(CONF_REQ_SENT, &chan->conf_state) ||
1690 rsp.result != L2CAP_CR_SUCCESS) {
1691 l2cap_chan_unlock(chan);
1692 continue;
1693 }
1694
1695 set_bit(CONF_REQ_SENT, &chan->conf_state);
1696 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
1697 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
1698 chan->num_conf_req++;
1699 }
1700
1701 l2cap_chan_unlock(chan);
1702 }
1703
1704 mutex_unlock(&conn->chan_lock);
1705 }
1706
l2cap_le_conn_ready(struct l2cap_conn * conn)1707 static void l2cap_le_conn_ready(struct l2cap_conn *conn)
1708 {
1709 struct hci_conn *hcon = conn->hcon;
1710 struct hci_dev *hdev = hcon->hdev;
1711
1712 BT_DBG("%s conn %p", hdev->name, conn);
1713
1714 /* For outgoing pairing which doesn't necessarily have an
1715 * associated socket (e.g. mgmt_pair_device).
1716 */
1717 if (hcon->out)
1718 smp_conn_security(hcon, hcon->pending_sec_level);
1719
1720 /* For LE peripheral connections, make sure the connection interval
1721 * is in the range of the minimum and maximum interval that has
1722 * been configured for this connection. If not, then trigger
1723 * the connection update procedure.
1724 */
1725 if (hcon->role == HCI_ROLE_SLAVE &&
1726 (hcon->le_conn_interval < hcon->le_conn_min_interval ||
1727 hcon->le_conn_interval > hcon->le_conn_max_interval)) {
1728 struct l2cap_conn_param_update_req req;
1729
1730 req.min = cpu_to_le16(hcon->le_conn_min_interval);
1731 req.max = cpu_to_le16(hcon->le_conn_max_interval);
1732 req.latency = cpu_to_le16(hcon->le_conn_latency);
1733 req.to_multiplier = cpu_to_le16(hcon->le_supv_timeout);
1734
1735 l2cap_send_cmd(conn, l2cap_get_ident(conn),
1736 L2CAP_CONN_PARAM_UPDATE_REQ, sizeof(req), &req);
1737 }
1738 }
1739
l2cap_conn_ready(struct l2cap_conn * conn)1740 static void l2cap_conn_ready(struct l2cap_conn *conn)
1741 {
1742 struct l2cap_chan *chan;
1743 struct hci_conn *hcon = conn->hcon;
1744
1745 BT_DBG("conn %p", conn);
1746
1747 if (hcon->type == ACL_LINK)
1748 l2cap_request_info(conn);
1749
1750 mutex_lock(&conn->chan_lock);
1751
1752 list_for_each_entry(chan, &conn->chan_l, list) {
1753
1754 l2cap_chan_lock(chan);
1755
1756 if (chan->scid == L2CAP_CID_A2MP) {
1757 l2cap_chan_unlock(chan);
1758 continue;
1759 }
1760
1761 if (hcon->type == LE_LINK) {
1762 l2cap_le_start(chan);
1763 } else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1764 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
1765 l2cap_chan_ready(chan);
1766 } else if (chan->state == BT_CONNECT) {
1767 l2cap_do_start(chan);
1768 }
1769
1770 l2cap_chan_unlock(chan);
1771 }
1772
1773 mutex_unlock(&conn->chan_lock);
1774
1775 if (hcon->type == LE_LINK)
1776 l2cap_le_conn_ready(conn);
1777
1778 queue_work(hcon->hdev->workqueue, &conn->pending_rx_work);
1779 }
1780
1781 /* Notify sockets that we cannot guaranty reliability anymore */
l2cap_conn_unreliable(struct l2cap_conn * conn,int err)1782 static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
1783 {
1784 struct l2cap_chan *chan;
1785
1786 BT_DBG("conn %p", conn);
1787
1788 mutex_lock(&conn->chan_lock);
1789
1790 list_for_each_entry(chan, &conn->chan_l, list) {
1791 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
1792 l2cap_chan_set_err(chan, err);
1793 }
1794
1795 mutex_unlock(&conn->chan_lock);
1796 }
1797
l2cap_info_timeout(struct work_struct * work)1798 static void l2cap_info_timeout(struct work_struct *work)
1799 {
1800 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
1801 info_timer.work);
1802
1803 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
1804 conn->info_ident = 0;
1805
1806 l2cap_conn_start(conn);
1807 }
1808
1809 /*
1810 * l2cap_user
1811 * External modules can register l2cap_user objects on l2cap_conn. The ->probe
1812 * callback is called during registration. The ->remove callback is called
1813 * during unregistration.
1814 * An l2cap_user object can either be explicitly unregistered or when the
1815 * underlying l2cap_conn object is deleted. This guarantees that l2cap->hcon,
1816 * l2cap->hchan, .. are valid as long as the remove callback hasn't been called.
1817 * External modules must own a reference to the l2cap_conn object if they intend
1818 * to call l2cap_unregister_user(). The l2cap_conn object might get destroyed at
1819 * any time if they don't.
1820 */
1821
l2cap_register_user(struct l2cap_conn * conn,struct l2cap_user * user)1822 int l2cap_register_user(struct l2cap_conn *conn, struct l2cap_user *user)
1823 {
1824 struct hci_dev *hdev = conn->hcon->hdev;
1825 int ret;
1826
1827 /* We need to check whether l2cap_conn is registered. If it is not, we
1828 * must not register the l2cap_user. l2cap_conn_del() is unregisters
1829 * l2cap_conn objects, but doesn't provide its own locking. Instead, it
1830 * relies on the parent hci_conn object to be locked. This itself relies
1831 * on the hci_dev object to be locked. So we must lock the hci device
1832 * here, too. */
1833
1834 hci_dev_lock(hdev);
1835
1836 if (!list_empty(&user->list)) {
1837 ret = -EINVAL;
1838 goto out_unlock;
1839 }
1840
1841 /* conn->hchan is NULL after l2cap_conn_del() was called */
1842 if (!conn->hchan) {
1843 ret = -ENODEV;
1844 goto out_unlock;
1845 }
1846
1847 ret = user->probe(conn, user);
1848 if (ret)
1849 goto out_unlock;
1850
1851 list_add(&user->list, &conn->users);
1852 ret = 0;
1853
1854 out_unlock:
1855 hci_dev_unlock(hdev);
1856 return ret;
1857 }
1858 EXPORT_SYMBOL(l2cap_register_user);
1859
l2cap_unregister_user(struct l2cap_conn * conn,struct l2cap_user * user)1860 void l2cap_unregister_user(struct l2cap_conn *conn, struct l2cap_user *user)
1861 {
1862 struct hci_dev *hdev = conn->hcon->hdev;
1863
1864 hci_dev_lock(hdev);
1865
1866 if (list_empty(&user->list))
1867 goto out_unlock;
1868
1869 list_del_init(&user->list);
1870 user->remove(conn, user);
1871
1872 out_unlock:
1873 hci_dev_unlock(hdev);
1874 }
1875 EXPORT_SYMBOL(l2cap_unregister_user);
1876
l2cap_unregister_all_users(struct l2cap_conn * conn)1877 static void l2cap_unregister_all_users(struct l2cap_conn *conn)
1878 {
1879 struct l2cap_user *user;
1880
1881 while (!list_empty(&conn->users)) {
1882 user = list_first_entry(&conn->users, struct l2cap_user, list);
1883 list_del_init(&user->list);
1884 user->remove(conn, user);
1885 }
1886 }
1887
l2cap_conn_del(struct hci_conn * hcon,int err)1888 static void l2cap_conn_del(struct hci_conn *hcon, int err)
1889 {
1890 struct l2cap_conn *conn = hcon->l2cap_data;
1891 struct l2cap_chan *chan, *l;
1892
1893 if (!conn)
1894 return;
1895
1896 BT_DBG("hcon %p conn %p, err %d", hcon, conn, err);
1897
1898 kfree_skb(conn->rx_skb);
1899
1900 skb_queue_purge(&conn->pending_rx);
1901
1902 /* We can not call flush_work(&conn->pending_rx_work) here since we
1903 * might block if we are running on a worker from the same workqueue
1904 * pending_rx_work is waiting on.
1905 */
1906 if (work_pending(&conn->pending_rx_work))
1907 cancel_work_sync(&conn->pending_rx_work);
1908
1909 if (work_pending(&conn->id_addr_update_work))
1910 cancel_work_sync(&conn->id_addr_update_work);
1911
1912 l2cap_unregister_all_users(conn);
1913
1914 /* Force the connection to be immediately dropped */
1915 hcon->disc_timeout = 0;
1916
1917 mutex_lock(&conn->chan_lock);
1918
1919 /* Kill channels */
1920 list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
1921 l2cap_chan_hold(chan);
1922 l2cap_chan_lock(chan);
1923
1924 l2cap_chan_del(chan, err);
1925
1926 chan->ops->close(chan);
1927
1928 l2cap_chan_unlock(chan);
1929 l2cap_chan_put(chan);
1930 }
1931
1932 mutex_unlock(&conn->chan_lock);
1933
1934 hci_chan_del(conn->hchan);
1935
1936 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1937 cancel_delayed_work_sync(&conn->info_timer);
1938
1939 hcon->l2cap_data = NULL;
1940 conn->hchan = NULL;
1941 l2cap_conn_put(conn);
1942 }
1943
l2cap_conn_free(struct kref * ref)1944 static void l2cap_conn_free(struct kref *ref)
1945 {
1946 struct l2cap_conn *conn = container_of(ref, struct l2cap_conn, ref);
1947
1948 hci_conn_put(conn->hcon);
1949 kfree(conn);
1950 }
1951
l2cap_conn_get(struct l2cap_conn * conn)1952 struct l2cap_conn *l2cap_conn_get(struct l2cap_conn *conn)
1953 {
1954 kref_get(&conn->ref);
1955 return conn;
1956 }
1957 EXPORT_SYMBOL(l2cap_conn_get);
1958
l2cap_conn_put(struct l2cap_conn * conn)1959 void l2cap_conn_put(struct l2cap_conn *conn)
1960 {
1961 kref_put(&conn->ref, l2cap_conn_free);
1962 }
1963 EXPORT_SYMBOL(l2cap_conn_put);
1964
1965 /* ---- Socket interface ---- */
1966
1967 /* Find socket with psm and source / destination bdaddr.
1968 * Returns closest match.
1969 */
l2cap_global_chan_by_psm(int state,__le16 psm,bdaddr_t * src,bdaddr_t * dst,u8 link_type)1970 static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
1971 bdaddr_t *src,
1972 bdaddr_t *dst,
1973 u8 link_type)
1974 {
1975 struct l2cap_chan *c, *tmp, *c1 = NULL;
1976
1977 read_lock(&chan_list_lock);
1978
1979 list_for_each_entry_safe(c, tmp, &chan_list, global_l) {
1980 if (state && c->state != state)
1981 continue;
1982
1983 if (link_type == ACL_LINK && c->src_type != BDADDR_BREDR)
1984 continue;
1985
1986 if (link_type == LE_LINK && c->src_type == BDADDR_BREDR)
1987 continue;
1988
1989 if (c->chan_type != L2CAP_CHAN_FIXED && c->psm == psm) {
1990 int src_match, dst_match;
1991 int src_any, dst_any;
1992
1993 /* Exact match. */
1994 src_match = !bacmp(&c->src, src);
1995 dst_match = !bacmp(&c->dst, dst);
1996 if (src_match && dst_match) {
1997 if (!l2cap_chan_hold_unless_zero(c))
1998 continue;
1999
2000 read_unlock(&chan_list_lock);
2001 return c;
2002 }
2003
2004 /* Closest match */
2005 src_any = !bacmp(&c->src, BDADDR_ANY);
2006 dst_any = !bacmp(&c->dst, BDADDR_ANY);
2007 if ((src_match && dst_any) || (src_any && dst_match) ||
2008 (src_any && dst_any))
2009 c1 = c;
2010 }
2011 }
2012
2013 if (c1)
2014 c1 = l2cap_chan_hold_unless_zero(c1);
2015
2016 read_unlock(&chan_list_lock);
2017
2018 return c1;
2019 }
2020
l2cap_monitor_timeout(struct work_struct * work)2021 static void l2cap_monitor_timeout(struct work_struct *work)
2022 {
2023 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
2024 monitor_timer.work);
2025
2026 BT_DBG("chan %p", chan);
2027
2028 l2cap_chan_lock(chan);
2029
2030 if (!chan->conn) {
2031 l2cap_chan_unlock(chan);
2032 l2cap_chan_put(chan);
2033 return;
2034 }
2035
2036 l2cap_tx(chan, NULL, NULL, L2CAP_EV_MONITOR_TO);
2037
2038 l2cap_chan_unlock(chan);
2039 l2cap_chan_put(chan);
2040 }
2041
l2cap_retrans_timeout(struct work_struct * work)2042 static void l2cap_retrans_timeout(struct work_struct *work)
2043 {
2044 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
2045 retrans_timer.work);
2046
2047 BT_DBG("chan %p", chan);
2048
2049 l2cap_chan_lock(chan);
2050
2051 if (!chan->conn) {
2052 l2cap_chan_unlock(chan);
2053 l2cap_chan_put(chan);
2054 return;
2055 }
2056
2057 l2cap_tx(chan, NULL, NULL, L2CAP_EV_RETRANS_TO);
2058 l2cap_chan_unlock(chan);
2059 l2cap_chan_put(chan);
2060 }
2061
l2cap_streaming_send(struct l2cap_chan * chan,struct sk_buff_head * skbs)2062 static void l2cap_streaming_send(struct l2cap_chan *chan,
2063 struct sk_buff_head *skbs)
2064 {
2065 struct sk_buff *skb;
2066 struct l2cap_ctrl *control;
2067
2068 BT_DBG("chan %p, skbs %p", chan, skbs);
2069
2070 if (__chan_is_moving(chan))
2071 return;
2072
2073 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2074
2075 while (!skb_queue_empty(&chan->tx_q)) {
2076
2077 skb = skb_dequeue(&chan->tx_q);
2078
2079 bt_cb(skb)->l2cap.retries = 1;
2080 control = &bt_cb(skb)->l2cap;
2081
2082 control->reqseq = 0;
2083 control->txseq = chan->next_tx_seq;
2084
2085 __pack_control(chan, control, skb);
2086
2087 if (chan->fcs == L2CAP_FCS_CRC16) {
2088 u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
2089 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
2090 }
2091
2092 l2cap_do_send(chan, skb);
2093
2094 BT_DBG("Sent txseq %u", control->txseq);
2095
2096 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
2097 chan->frames_sent++;
2098 }
2099 }
2100
l2cap_ertm_send(struct l2cap_chan * chan)2101 static int l2cap_ertm_send(struct l2cap_chan *chan)
2102 {
2103 struct sk_buff *skb, *tx_skb;
2104 struct l2cap_ctrl *control;
2105 int sent = 0;
2106
2107 BT_DBG("chan %p", chan);
2108
2109 if (chan->state != BT_CONNECTED)
2110 return -ENOTCONN;
2111
2112 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
2113 return 0;
2114
2115 if (__chan_is_moving(chan))
2116 return 0;
2117
2118 while (chan->tx_send_head &&
2119 chan->unacked_frames < chan->remote_tx_win &&
2120 chan->tx_state == L2CAP_TX_STATE_XMIT) {
2121
2122 skb = chan->tx_send_head;
2123
2124 bt_cb(skb)->l2cap.retries = 1;
2125 control = &bt_cb(skb)->l2cap;
2126
2127 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
2128 control->final = 1;
2129
2130 control->reqseq = chan->buffer_seq;
2131 chan->last_acked_seq = chan->buffer_seq;
2132 control->txseq = chan->next_tx_seq;
2133
2134 __pack_control(chan, control, skb);
2135
2136 if (chan->fcs == L2CAP_FCS_CRC16) {
2137 u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
2138 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
2139 }
2140
2141 /* Clone after data has been modified. Data is assumed to be
2142 read-only (for locking purposes) on cloned sk_buffs.
2143 */
2144 tx_skb = skb_clone(skb, GFP_KERNEL);
2145
2146 if (!tx_skb)
2147 break;
2148
2149 __set_retrans_timer(chan);
2150
2151 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
2152 chan->unacked_frames++;
2153 chan->frames_sent++;
2154 sent++;
2155
2156 if (skb_queue_is_last(&chan->tx_q, skb))
2157 chan->tx_send_head = NULL;
2158 else
2159 chan->tx_send_head = skb_queue_next(&chan->tx_q, skb);
2160
2161 l2cap_do_send(chan, tx_skb);
2162 BT_DBG("Sent txseq %u", control->txseq);
2163 }
2164
2165 BT_DBG("Sent %d, %u unacked, %u in ERTM queue", sent,
2166 chan->unacked_frames, skb_queue_len(&chan->tx_q));
2167
2168 return sent;
2169 }
2170
l2cap_ertm_resend(struct l2cap_chan * chan)2171 static void l2cap_ertm_resend(struct l2cap_chan *chan)
2172 {
2173 struct l2cap_ctrl control;
2174 struct sk_buff *skb;
2175 struct sk_buff *tx_skb;
2176 u16 seq;
2177
2178 BT_DBG("chan %p", chan);
2179
2180 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
2181 return;
2182
2183 if (__chan_is_moving(chan))
2184 return;
2185
2186 while (chan->retrans_list.head != L2CAP_SEQ_LIST_CLEAR) {
2187 seq = l2cap_seq_list_pop(&chan->retrans_list);
2188
2189 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, seq);
2190 if (!skb) {
2191 BT_DBG("Error: Can't retransmit seq %d, frame missing",
2192 seq);
2193 continue;
2194 }
2195
2196 bt_cb(skb)->l2cap.retries++;
2197 control = bt_cb(skb)->l2cap;
2198
2199 if (chan->max_tx != 0 &&
2200 bt_cb(skb)->l2cap.retries > chan->max_tx) {
2201 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
2202 l2cap_send_disconn_req(chan, ECONNRESET);
2203 l2cap_seq_list_clear(&chan->retrans_list);
2204 break;
2205 }
2206
2207 control.reqseq = chan->buffer_seq;
2208 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
2209 control.final = 1;
2210 else
2211 control.final = 0;
2212
2213 if (skb_cloned(skb)) {
2214 /* Cloned sk_buffs are read-only, so we need a
2215 * writeable copy
2216 */
2217 tx_skb = skb_copy(skb, GFP_KERNEL);
2218 } else {
2219 tx_skb = skb_clone(skb, GFP_KERNEL);
2220 }
2221
2222 if (!tx_skb) {
2223 l2cap_seq_list_clear(&chan->retrans_list);
2224 break;
2225 }
2226
2227 /* Update skb contents */
2228 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
2229 put_unaligned_le32(__pack_extended_control(&control),
2230 tx_skb->data + L2CAP_HDR_SIZE);
2231 } else {
2232 put_unaligned_le16(__pack_enhanced_control(&control),
2233 tx_skb->data + L2CAP_HDR_SIZE);
2234 }
2235
2236 /* Update FCS */
2237 if (chan->fcs == L2CAP_FCS_CRC16) {
2238 u16 fcs = crc16(0, (u8 *) tx_skb->data,
2239 tx_skb->len - L2CAP_FCS_SIZE);
2240 put_unaligned_le16(fcs, skb_tail_pointer(tx_skb) -
2241 L2CAP_FCS_SIZE);
2242 }
2243
2244 l2cap_do_send(chan, tx_skb);
2245
2246 BT_DBG("Resent txseq %d", control.txseq);
2247
2248 chan->last_acked_seq = chan->buffer_seq;
2249 }
2250 }
2251
l2cap_retransmit(struct l2cap_chan * chan,struct l2cap_ctrl * control)2252 static void l2cap_retransmit(struct l2cap_chan *chan,
2253 struct l2cap_ctrl *control)
2254 {
2255 BT_DBG("chan %p, control %p", chan, control);
2256
2257 l2cap_seq_list_append(&chan->retrans_list, control->reqseq);
2258 l2cap_ertm_resend(chan);
2259 }
2260
l2cap_retransmit_all(struct l2cap_chan * chan,struct l2cap_ctrl * control)2261 static void l2cap_retransmit_all(struct l2cap_chan *chan,
2262 struct l2cap_ctrl *control)
2263 {
2264 struct sk_buff *skb;
2265
2266 BT_DBG("chan %p, control %p", chan, control);
2267
2268 if (control->poll)
2269 set_bit(CONN_SEND_FBIT, &chan->conn_state);
2270
2271 l2cap_seq_list_clear(&chan->retrans_list);
2272
2273 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
2274 return;
2275
2276 if (chan->unacked_frames) {
2277 skb_queue_walk(&chan->tx_q, skb) {
2278 if (bt_cb(skb)->l2cap.txseq == control->reqseq ||
2279 skb == chan->tx_send_head)
2280 break;
2281 }
2282
2283 skb_queue_walk_from(&chan->tx_q, skb) {
2284 if (skb == chan->tx_send_head)
2285 break;
2286
2287 l2cap_seq_list_append(&chan->retrans_list,
2288 bt_cb(skb)->l2cap.txseq);
2289 }
2290
2291 l2cap_ertm_resend(chan);
2292 }
2293 }
2294
l2cap_send_ack(struct l2cap_chan * chan)2295 static void l2cap_send_ack(struct l2cap_chan *chan)
2296 {
2297 struct l2cap_ctrl control;
2298 u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
2299 chan->last_acked_seq);
2300 int threshold;
2301
2302 BT_DBG("chan %p last_acked_seq %d buffer_seq %d",
2303 chan, chan->last_acked_seq, chan->buffer_seq);
2304
2305 memset(&control, 0, sizeof(control));
2306 control.sframe = 1;
2307
2308 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
2309 chan->rx_state == L2CAP_RX_STATE_RECV) {
2310 __clear_ack_timer(chan);
2311 control.super = L2CAP_SUPER_RNR;
2312 control.reqseq = chan->buffer_seq;
2313 l2cap_send_sframe(chan, &control);
2314 } else {
2315 if (!test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) {
2316 l2cap_ertm_send(chan);
2317 /* If any i-frames were sent, they included an ack */
2318 if (chan->buffer_seq == chan->last_acked_seq)
2319 frames_to_ack = 0;
2320 }
2321
2322 /* Ack now if the window is 3/4ths full.
2323 * Calculate without mul or div
2324 */
2325 threshold = chan->ack_win;
2326 threshold += threshold << 1;
2327 threshold >>= 2;
2328
2329 BT_DBG("frames_to_ack %u, threshold %d", frames_to_ack,
2330 threshold);
2331
2332 if (frames_to_ack >= threshold) {
2333 __clear_ack_timer(chan);
2334 control.super = L2CAP_SUPER_RR;
2335 control.reqseq = chan->buffer_seq;
2336 l2cap_send_sframe(chan, &control);
2337 frames_to_ack = 0;
2338 }
2339
2340 if (frames_to_ack)
2341 __set_ack_timer(chan);
2342 }
2343 }
2344
l2cap_skbuff_fromiovec(struct l2cap_chan * chan,struct msghdr * msg,int len,int count,struct sk_buff * skb)2345 static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
2346 struct msghdr *msg, int len,
2347 int count, struct sk_buff *skb)
2348 {
2349 struct l2cap_conn *conn = chan->conn;
2350 struct sk_buff **frag;
2351 int sent = 0;
2352
2353 if (!copy_from_iter_full(skb_put(skb, count), count, &msg->msg_iter))
2354 return -EFAULT;
2355
2356 sent += count;
2357 len -= count;
2358
2359 /* Continuation fragments (no L2CAP header) */
2360 frag = &skb_shinfo(skb)->frag_list;
2361 while (len) {
2362 struct sk_buff *tmp;
2363
2364 count = min_t(unsigned int, conn->mtu, len);
2365
2366 tmp = chan->ops->alloc_skb(chan, 0, count,
2367 msg->msg_flags & MSG_DONTWAIT);
2368 if (IS_ERR(tmp))
2369 return PTR_ERR(tmp);
2370
2371 *frag = tmp;
2372
2373 if (!copy_from_iter_full(skb_put(*frag, count), count,
2374 &msg->msg_iter))
2375 return -EFAULT;
2376
2377 sent += count;
2378 len -= count;
2379
2380 skb->len += (*frag)->len;
2381 skb->data_len += (*frag)->len;
2382
2383 frag = &(*frag)->next;
2384 }
2385
2386 return sent;
2387 }
2388
l2cap_create_connless_pdu(struct l2cap_chan * chan,struct msghdr * msg,size_t len)2389 static struct sk_buff *l2cap_create_connless_pdu(struct l2cap_chan *chan,
2390 struct msghdr *msg, size_t len)
2391 {
2392 struct l2cap_conn *conn = chan->conn;
2393 struct sk_buff *skb;
2394 int err, count, hlen = L2CAP_HDR_SIZE + L2CAP_PSMLEN_SIZE;
2395 struct l2cap_hdr *lh;
2396
2397 BT_DBG("chan %p psm 0x%2.2x len %zu", chan,
2398 __le16_to_cpu(chan->psm), len);
2399
2400 count = min_t(unsigned int, (conn->mtu - hlen), len);
2401
2402 skb = chan->ops->alloc_skb(chan, hlen, count,
2403 msg->msg_flags & MSG_DONTWAIT);
2404 if (IS_ERR(skb))
2405 return skb;
2406
2407 /* Create L2CAP header */
2408 lh = skb_put(skb, L2CAP_HDR_SIZE);
2409 lh->cid = cpu_to_le16(chan->dcid);
2410 lh->len = cpu_to_le16(len + L2CAP_PSMLEN_SIZE);
2411 put_unaligned(chan->psm, (__le16 *) skb_put(skb, L2CAP_PSMLEN_SIZE));
2412
2413 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2414 if (unlikely(err < 0)) {
2415 kfree_skb(skb);
2416 return ERR_PTR(err);
2417 }
2418 return skb;
2419 }
2420
l2cap_create_basic_pdu(struct l2cap_chan * chan,struct msghdr * msg,size_t len)2421 static struct sk_buff *l2cap_create_basic_pdu(struct l2cap_chan *chan,
2422 struct msghdr *msg, size_t len)
2423 {
2424 struct l2cap_conn *conn = chan->conn;
2425 struct sk_buff *skb;
2426 int err, count;
2427 struct l2cap_hdr *lh;
2428
2429 BT_DBG("chan %p len %zu", chan, len);
2430
2431 count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len);
2432
2433 skb = chan->ops->alloc_skb(chan, L2CAP_HDR_SIZE, count,
2434 msg->msg_flags & MSG_DONTWAIT);
2435 if (IS_ERR(skb))
2436 return skb;
2437
2438 /* Create L2CAP header */
2439 lh = skb_put(skb, L2CAP_HDR_SIZE);
2440 lh->cid = cpu_to_le16(chan->dcid);
2441 lh->len = cpu_to_le16(len);
2442
2443 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2444 if (unlikely(err < 0)) {
2445 kfree_skb(skb);
2446 return ERR_PTR(err);
2447 }
2448 return skb;
2449 }
2450
l2cap_create_iframe_pdu(struct l2cap_chan * chan,struct msghdr * msg,size_t len,u16 sdulen)2451 static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan,
2452 struct msghdr *msg, size_t len,
2453 u16 sdulen)
2454 {
2455 struct l2cap_conn *conn = chan->conn;
2456 struct sk_buff *skb;
2457 int err, count, hlen;
2458 struct l2cap_hdr *lh;
2459
2460 BT_DBG("chan %p len %zu", chan, len);
2461
2462 if (!conn)
2463 return ERR_PTR(-ENOTCONN);
2464
2465 hlen = __ertm_hdr_size(chan);
2466
2467 if (sdulen)
2468 hlen += L2CAP_SDULEN_SIZE;
2469
2470 if (chan->fcs == L2CAP_FCS_CRC16)
2471 hlen += L2CAP_FCS_SIZE;
2472
2473 count = min_t(unsigned int, (conn->mtu - hlen), len);
2474
2475 skb = chan->ops->alloc_skb(chan, hlen, count,
2476 msg->msg_flags & MSG_DONTWAIT);
2477 if (IS_ERR(skb))
2478 return skb;
2479
2480 /* Create L2CAP header */
2481 lh = skb_put(skb, L2CAP_HDR_SIZE);
2482 lh->cid = cpu_to_le16(chan->dcid);
2483 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2484
2485 /* Control header is populated later */
2486 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
2487 put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
2488 else
2489 put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
2490
2491 if (sdulen)
2492 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2493
2494 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2495 if (unlikely(err < 0)) {
2496 kfree_skb(skb);
2497 return ERR_PTR(err);
2498 }
2499
2500 bt_cb(skb)->l2cap.fcs = chan->fcs;
2501 bt_cb(skb)->l2cap.retries = 0;
2502 return skb;
2503 }
2504
l2cap_segment_sdu(struct l2cap_chan * chan,struct sk_buff_head * seg_queue,struct msghdr * msg,size_t len)2505 static int l2cap_segment_sdu(struct l2cap_chan *chan,
2506 struct sk_buff_head *seg_queue,
2507 struct msghdr *msg, size_t len)
2508 {
2509 struct sk_buff *skb;
2510 u16 sdu_len;
2511 size_t pdu_len;
2512 u8 sar;
2513
2514 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2515
2516 /* It is critical that ERTM PDUs fit in a single HCI fragment,
2517 * so fragmented skbs are not used. The HCI layer's handling
2518 * of fragmented skbs is not compatible with ERTM's queueing.
2519 */
2520
2521 /* PDU size is derived from the HCI MTU */
2522 pdu_len = chan->conn->mtu;
2523
2524 /* Constrain PDU size for BR/EDR connections */
2525 if (!chan->hs_hcon)
2526 pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD);
2527
2528 /* Adjust for largest possible L2CAP overhead. */
2529 if (chan->fcs)
2530 pdu_len -= L2CAP_FCS_SIZE;
2531
2532 pdu_len -= __ertm_hdr_size(chan);
2533
2534 /* Remote device may have requested smaller PDUs */
2535 pdu_len = min_t(size_t, pdu_len, chan->remote_mps);
2536
2537 if (len <= pdu_len) {
2538 sar = L2CAP_SAR_UNSEGMENTED;
2539 sdu_len = 0;
2540 pdu_len = len;
2541 } else {
2542 sar = L2CAP_SAR_START;
2543 sdu_len = len;
2544 }
2545
2546 while (len > 0) {
2547 skb = l2cap_create_iframe_pdu(chan, msg, pdu_len, sdu_len);
2548
2549 if (IS_ERR(skb)) {
2550 __skb_queue_purge(seg_queue);
2551 return PTR_ERR(skb);
2552 }
2553
2554 bt_cb(skb)->l2cap.sar = sar;
2555 __skb_queue_tail(seg_queue, skb);
2556
2557 len -= pdu_len;
2558 if (sdu_len)
2559 sdu_len = 0;
2560
2561 if (len <= pdu_len) {
2562 sar = L2CAP_SAR_END;
2563 pdu_len = len;
2564 } else {
2565 sar = L2CAP_SAR_CONTINUE;
2566 }
2567 }
2568
2569 return 0;
2570 }
2571
l2cap_create_le_flowctl_pdu(struct l2cap_chan * chan,struct msghdr * msg,size_t len,u16 sdulen)2572 static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan,
2573 struct msghdr *msg,
2574 size_t len, u16 sdulen)
2575 {
2576 struct l2cap_conn *conn = chan->conn;
2577 struct sk_buff *skb;
2578 int err, count, hlen;
2579 struct l2cap_hdr *lh;
2580
2581 BT_DBG("chan %p len %zu", chan, len);
2582
2583 if (!conn)
2584 return ERR_PTR(-ENOTCONN);
2585
2586 hlen = L2CAP_HDR_SIZE;
2587
2588 if (sdulen)
2589 hlen += L2CAP_SDULEN_SIZE;
2590
2591 count = min_t(unsigned int, (conn->mtu - hlen), len);
2592
2593 skb = chan->ops->alloc_skb(chan, hlen, count,
2594 msg->msg_flags & MSG_DONTWAIT);
2595 if (IS_ERR(skb))
2596 return skb;
2597
2598 /* Create L2CAP header */
2599 lh = skb_put(skb, L2CAP_HDR_SIZE);
2600 lh->cid = cpu_to_le16(chan->dcid);
2601 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2602
2603 if (sdulen)
2604 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2605
2606 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2607 if (unlikely(err < 0)) {
2608 kfree_skb(skb);
2609 return ERR_PTR(err);
2610 }
2611
2612 return skb;
2613 }
2614
l2cap_segment_le_sdu(struct l2cap_chan * chan,struct sk_buff_head * seg_queue,struct msghdr * msg,size_t len)2615 static int l2cap_segment_le_sdu(struct l2cap_chan *chan,
2616 struct sk_buff_head *seg_queue,
2617 struct msghdr *msg, size_t len)
2618 {
2619 struct sk_buff *skb;
2620 size_t pdu_len;
2621 u16 sdu_len;
2622
2623 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2624
2625 sdu_len = len;
2626 pdu_len = chan->remote_mps - L2CAP_SDULEN_SIZE;
2627
2628 while (len > 0) {
2629 if (len <= pdu_len)
2630 pdu_len = len;
2631
2632 skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len);
2633 if (IS_ERR(skb)) {
2634 __skb_queue_purge(seg_queue);
2635 return PTR_ERR(skb);
2636 }
2637
2638 __skb_queue_tail(seg_queue, skb);
2639
2640 len -= pdu_len;
2641
2642 if (sdu_len) {
2643 sdu_len = 0;
2644 pdu_len += L2CAP_SDULEN_SIZE;
2645 }
2646 }
2647
2648 return 0;
2649 }
2650
l2cap_le_flowctl_send(struct l2cap_chan * chan)2651 static void l2cap_le_flowctl_send(struct l2cap_chan *chan)
2652 {
2653 int sent = 0;
2654
2655 BT_DBG("chan %p", chan);
2656
2657 while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) {
2658 l2cap_do_send(chan, skb_dequeue(&chan->tx_q));
2659 chan->tx_credits--;
2660 sent++;
2661 }
2662
2663 BT_DBG("Sent %d credits %u queued %u", sent, chan->tx_credits,
2664 skb_queue_len(&chan->tx_q));
2665 }
2666
l2cap_chan_send(struct l2cap_chan * chan,struct msghdr * msg,size_t len)2667 int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len)
2668 {
2669 struct sk_buff *skb;
2670 int err;
2671 struct sk_buff_head seg_queue;
2672
2673 if (!chan->conn)
2674 return -ENOTCONN;
2675
2676 /* Connectionless channel */
2677 if (chan->chan_type == L2CAP_CHAN_CONN_LESS) {
2678 skb = l2cap_create_connless_pdu(chan, msg, len);
2679 if (IS_ERR(skb))
2680 return PTR_ERR(skb);
2681
2682 l2cap_do_send(chan, skb);
2683 return len;
2684 }
2685
2686 switch (chan->mode) {
2687 case L2CAP_MODE_LE_FLOWCTL:
2688 case L2CAP_MODE_EXT_FLOWCTL:
2689 /* Check outgoing MTU */
2690 if (len > chan->omtu)
2691 return -EMSGSIZE;
2692
2693 __skb_queue_head_init(&seg_queue);
2694
2695 err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len);
2696
2697 if (chan->state != BT_CONNECTED) {
2698 __skb_queue_purge(&seg_queue);
2699 err = -ENOTCONN;
2700 }
2701
2702 if (err)
2703 return err;
2704
2705 skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
2706
2707 l2cap_le_flowctl_send(chan);
2708
2709 if (!chan->tx_credits)
2710 chan->ops->suspend(chan);
2711
2712 err = len;
2713
2714 break;
2715
2716 case L2CAP_MODE_BASIC:
2717 /* Check outgoing MTU */
2718 if (len > chan->omtu)
2719 return -EMSGSIZE;
2720
2721 /* Create a basic PDU */
2722 skb = l2cap_create_basic_pdu(chan, msg, len);
2723 if (IS_ERR(skb))
2724 return PTR_ERR(skb);
2725
2726 l2cap_do_send(chan, skb);
2727 err = len;
2728 break;
2729
2730 case L2CAP_MODE_ERTM:
2731 case L2CAP_MODE_STREAMING:
2732 /* Check outgoing MTU */
2733 if (len > chan->omtu) {
2734 err = -EMSGSIZE;
2735 break;
2736 }
2737
2738 __skb_queue_head_init(&seg_queue);
2739
2740 /* Do segmentation before calling in to the state machine,
2741 * since it's possible to block while waiting for memory
2742 * allocation.
2743 */
2744 err = l2cap_segment_sdu(chan, &seg_queue, msg, len);
2745
2746 if (err)
2747 break;
2748
2749 if (chan->mode == L2CAP_MODE_ERTM)
2750 l2cap_tx(chan, NULL, &seg_queue, L2CAP_EV_DATA_REQUEST);
2751 else
2752 l2cap_streaming_send(chan, &seg_queue);
2753
2754 err = len;
2755
2756 /* If the skbs were not queued for sending, they'll still be in
2757 * seg_queue and need to be purged.
2758 */
2759 __skb_queue_purge(&seg_queue);
2760 break;
2761
2762 default:
2763 BT_DBG("bad state %1.1x", chan->mode);
2764 err = -EBADFD;
2765 }
2766
2767 return err;
2768 }
2769 EXPORT_SYMBOL_GPL(l2cap_chan_send);
2770
l2cap_send_srej(struct l2cap_chan * chan,u16 txseq)2771 static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq)
2772 {
2773 struct l2cap_ctrl control;
2774 u16 seq;
2775
2776 BT_DBG("chan %p, txseq %u", chan, txseq);
2777
2778 memset(&control, 0, sizeof(control));
2779 control.sframe = 1;
2780 control.super = L2CAP_SUPER_SREJ;
2781
2782 for (seq = chan->expected_tx_seq; seq != txseq;
2783 seq = __next_seq(chan, seq)) {
2784 if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) {
2785 control.reqseq = seq;
2786 l2cap_send_sframe(chan, &control);
2787 l2cap_seq_list_append(&chan->srej_list, seq);
2788 }
2789 }
2790
2791 chan->expected_tx_seq = __next_seq(chan, txseq);
2792 }
2793
l2cap_send_srej_tail(struct l2cap_chan * chan)2794 static void l2cap_send_srej_tail(struct l2cap_chan *chan)
2795 {
2796 struct l2cap_ctrl control;
2797
2798 BT_DBG("chan %p", chan);
2799
2800 if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR)
2801 return;
2802
2803 memset(&control, 0, sizeof(control));
2804 control.sframe = 1;
2805 control.super = L2CAP_SUPER_SREJ;
2806 control.reqseq = chan->srej_list.tail;
2807 l2cap_send_sframe(chan, &control);
2808 }
2809
l2cap_send_srej_list(struct l2cap_chan * chan,u16 txseq)2810 static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq)
2811 {
2812 struct l2cap_ctrl control;
2813 u16 initial_head;
2814 u16 seq;
2815
2816 BT_DBG("chan %p, txseq %u", chan, txseq);
2817
2818 memset(&control, 0, sizeof(control));
2819 control.sframe = 1;
2820 control.super = L2CAP_SUPER_SREJ;
2821
2822 /* Capture initial list head to allow only one pass through the list. */
2823 initial_head = chan->srej_list.head;
2824
2825 do {
2826 seq = l2cap_seq_list_pop(&chan->srej_list);
2827 if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR)
2828 break;
2829
2830 control.reqseq = seq;
2831 l2cap_send_sframe(chan, &control);
2832 l2cap_seq_list_append(&chan->srej_list, seq);
2833 } while (chan->srej_list.head != initial_head);
2834 }
2835
l2cap_process_reqseq(struct l2cap_chan * chan,u16 reqseq)2836 static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq)
2837 {
2838 struct sk_buff *acked_skb;
2839 u16 ackseq;
2840
2841 BT_DBG("chan %p, reqseq %u", chan, reqseq);
2842
2843 if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq)
2844 return;
2845
2846 BT_DBG("expected_ack_seq %u, unacked_frames %u",
2847 chan->expected_ack_seq, chan->unacked_frames);
2848
2849 for (ackseq = chan->expected_ack_seq; ackseq != reqseq;
2850 ackseq = __next_seq(chan, ackseq)) {
2851
2852 acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq);
2853 if (acked_skb) {
2854 skb_unlink(acked_skb, &chan->tx_q);
2855 kfree_skb(acked_skb);
2856 chan->unacked_frames--;
2857 }
2858 }
2859
2860 chan->expected_ack_seq = reqseq;
2861
2862 if (chan->unacked_frames == 0)
2863 __clear_retrans_timer(chan);
2864
2865 BT_DBG("unacked_frames %u", chan->unacked_frames);
2866 }
2867
l2cap_abort_rx_srej_sent(struct l2cap_chan * chan)2868 static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan)
2869 {
2870 BT_DBG("chan %p", chan);
2871
2872 chan->expected_tx_seq = chan->buffer_seq;
2873 l2cap_seq_list_clear(&chan->srej_list);
2874 skb_queue_purge(&chan->srej_q);
2875 chan->rx_state = L2CAP_RX_STATE_RECV;
2876 }
2877
l2cap_tx_state_xmit(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff_head * skbs,u8 event)2878 static void l2cap_tx_state_xmit(struct l2cap_chan *chan,
2879 struct l2cap_ctrl *control,
2880 struct sk_buff_head *skbs, u8 event)
2881 {
2882 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2883 event);
2884
2885 switch (event) {
2886 case L2CAP_EV_DATA_REQUEST:
2887 if (chan->tx_send_head == NULL)
2888 chan->tx_send_head = skb_peek(skbs);
2889
2890 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2891 l2cap_ertm_send(chan);
2892 break;
2893 case L2CAP_EV_LOCAL_BUSY_DETECTED:
2894 BT_DBG("Enter LOCAL_BUSY");
2895 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2896
2897 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2898 /* The SREJ_SENT state must be aborted if we are to
2899 * enter the LOCAL_BUSY state.
2900 */
2901 l2cap_abort_rx_srej_sent(chan);
2902 }
2903
2904 l2cap_send_ack(chan);
2905
2906 break;
2907 case L2CAP_EV_LOCAL_BUSY_CLEAR:
2908 BT_DBG("Exit LOCAL_BUSY");
2909 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2910
2911 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2912 struct l2cap_ctrl local_control;
2913
2914 memset(&local_control, 0, sizeof(local_control));
2915 local_control.sframe = 1;
2916 local_control.super = L2CAP_SUPER_RR;
2917 local_control.poll = 1;
2918 local_control.reqseq = chan->buffer_seq;
2919 l2cap_send_sframe(chan, &local_control);
2920
2921 chan->retry_count = 1;
2922 __set_monitor_timer(chan);
2923 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2924 }
2925 break;
2926 case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2927 l2cap_process_reqseq(chan, control->reqseq);
2928 break;
2929 case L2CAP_EV_EXPLICIT_POLL:
2930 l2cap_send_rr_or_rnr(chan, 1);
2931 chan->retry_count = 1;
2932 __set_monitor_timer(chan);
2933 __clear_ack_timer(chan);
2934 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2935 break;
2936 case L2CAP_EV_RETRANS_TO:
2937 l2cap_send_rr_or_rnr(chan, 1);
2938 chan->retry_count = 1;
2939 __set_monitor_timer(chan);
2940 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2941 break;
2942 case L2CAP_EV_RECV_FBIT:
2943 /* Nothing to process */
2944 break;
2945 default:
2946 break;
2947 }
2948 }
2949
l2cap_tx_state_wait_f(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff_head * skbs,u8 event)2950 static void l2cap_tx_state_wait_f(struct l2cap_chan *chan,
2951 struct l2cap_ctrl *control,
2952 struct sk_buff_head *skbs, u8 event)
2953 {
2954 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2955 event);
2956
2957 switch (event) {
2958 case L2CAP_EV_DATA_REQUEST:
2959 if (chan->tx_send_head == NULL)
2960 chan->tx_send_head = skb_peek(skbs);
2961 /* Queue data, but don't send. */
2962 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2963 break;
2964 case L2CAP_EV_LOCAL_BUSY_DETECTED:
2965 BT_DBG("Enter LOCAL_BUSY");
2966 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2967
2968 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2969 /* The SREJ_SENT state must be aborted if we are to
2970 * enter the LOCAL_BUSY state.
2971 */
2972 l2cap_abort_rx_srej_sent(chan);
2973 }
2974
2975 l2cap_send_ack(chan);
2976
2977 break;
2978 case L2CAP_EV_LOCAL_BUSY_CLEAR:
2979 BT_DBG("Exit LOCAL_BUSY");
2980 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2981
2982 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2983 struct l2cap_ctrl local_control;
2984 memset(&local_control, 0, sizeof(local_control));
2985 local_control.sframe = 1;
2986 local_control.super = L2CAP_SUPER_RR;
2987 local_control.poll = 1;
2988 local_control.reqseq = chan->buffer_seq;
2989 l2cap_send_sframe(chan, &local_control);
2990
2991 chan->retry_count = 1;
2992 __set_monitor_timer(chan);
2993 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2994 }
2995 break;
2996 case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2997 l2cap_process_reqseq(chan, control->reqseq);
2998 fallthrough;
2999
3000 case L2CAP_EV_RECV_FBIT:
3001 if (control && control->final) {
3002 __clear_monitor_timer(chan);
3003 if (chan->unacked_frames > 0)
3004 __set_retrans_timer(chan);
3005 chan->retry_count = 0;
3006 chan->tx_state = L2CAP_TX_STATE_XMIT;
3007 BT_DBG("recv fbit tx_state 0x2.2%x", chan->tx_state);
3008 }
3009 break;
3010 case L2CAP_EV_EXPLICIT_POLL:
3011 /* Ignore */
3012 break;
3013 case L2CAP_EV_MONITOR_TO:
3014 if (chan->max_tx == 0 || chan->retry_count < chan->max_tx) {
3015 l2cap_send_rr_or_rnr(chan, 1);
3016 __set_monitor_timer(chan);
3017 chan->retry_count++;
3018 } else {
3019 l2cap_send_disconn_req(chan, ECONNABORTED);
3020 }
3021 break;
3022 default:
3023 break;
3024 }
3025 }
3026
l2cap_tx(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff_head * skbs,u8 event)3027 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
3028 struct sk_buff_head *skbs, u8 event)
3029 {
3030 BT_DBG("chan %p, control %p, skbs %p, event %d, state %d",
3031 chan, control, skbs, event, chan->tx_state);
3032
3033 switch (chan->tx_state) {
3034 case L2CAP_TX_STATE_XMIT:
3035 l2cap_tx_state_xmit(chan, control, skbs, event);
3036 break;
3037 case L2CAP_TX_STATE_WAIT_F:
3038 l2cap_tx_state_wait_f(chan, control, skbs, event);
3039 break;
3040 default:
3041 /* Ignore event */
3042 break;
3043 }
3044 }
3045
l2cap_pass_to_tx(struct l2cap_chan * chan,struct l2cap_ctrl * control)3046 static void l2cap_pass_to_tx(struct l2cap_chan *chan,
3047 struct l2cap_ctrl *control)
3048 {
3049 BT_DBG("chan %p, control %p", chan, control);
3050 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_REQSEQ_AND_FBIT);
3051 }
3052
l2cap_pass_to_tx_fbit(struct l2cap_chan * chan,struct l2cap_ctrl * control)3053 static void l2cap_pass_to_tx_fbit(struct l2cap_chan *chan,
3054 struct l2cap_ctrl *control)
3055 {
3056 BT_DBG("chan %p, control %p", chan, control);
3057 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_FBIT);
3058 }
3059
3060 /* Copy frame to all raw sockets on that connection */
l2cap_raw_recv(struct l2cap_conn * conn,struct sk_buff * skb)3061 static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
3062 {
3063 struct sk_buff *nskb;
3064 struct l2cap_chan *chan;
3065
3066 BT_DBG("conn %p", conn);
3067
3068 mutex_lock(&conn->chan_lock);
3069
3070 list_for_each_entry(chan, &conn->chan_l, list) {
3071 if (chan->chan_type != L2CAP_CHAN_RAW)
3072 continue;
3073
3074 /* Don't send frame to the channel it came from */
3075 if (bt_cb(skb)->l2cap.chan == chan)
3076 continue;
3077
3078 nskb = skb_clone(skb, GFP_KERNEL);
3079 if (!nskb)
3080 continue;
3081 if (chan->ops->recv(chan, nskb))
3082 kfree_skb(nskb);
3083 }
3084
3085 mutex_unlock(&conn->chan_lock);
3086 }
3087
3088 /* ---- L2CAP signalling commands ---- */
l2cap_build_cmd(struct l2cap_conn * conn,u8 code,u8 ident,u16 dlen,void * data)3089 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code,
3090 u8 ident, u16 dlen, void *data)
3091 {
3092 struct sk_buff *skb, **frag;
3093 struct l2cap_cmd_hdr *cmd;
3094 struct l2cap_hdr *lh;
3095 int len, count;
3096
3097 BT_DBG("conn %p, code 0x%2.2x, ident 0x%2.2x, len %u",
3098 conn, code, ident, dlen);
3099
3100 if (conn->mtu < L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE)
3101 return NULL;
3102
3103 len = L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE + dlen;
3104 count = min_t(unsigned int, conn->mtu, len);
3105
3106 skb = bt_skb_alloc(count, GFP_KERNEL);
3107 if (!skb)
3108 return NULL;
3109
3110 lh = skb_put(skb, L2CAP_HDR_SIZE);
3111 lh->len = cpu_to_le16(L2CAP_CMD_HDR_SIZE + dlen);
3112
3113 if (conn->hcon->type == LE_LINK)
3114 lh->cid = cpu_to_le16(L2CAP_CID_LE_SIGNALING);
3115 else
3116 lh->cid = cpu_to_le16(L2CAP_CID_SIGNALING);
3117
3118 cmd = skb_put(skb, L2CAP_CMD_HDR_SIZE);
3119 cmd->code = code;
3120 cmd->ident = ident;
3121 cmd->len = cpu_to_le16(dlen);
3122
3123 if (dlen) {
3124 count -= L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE;
3125 skb_put_data(skb, data, count);
3126 data += count;
3127 }
3128
3129 len -= skb->len;
3130
3131 /* Continuation fragments (no L2CAP header) */
3132 frag = &skb_shinfo(skb)->frag_list;
3133 while (len) {
3134 count = min_t(unsigned int, conn->mtu, len);
3135
3136 *frag = bt_skb_alloc(count, GFP_KERNEL);
3137 if (!*frag)
3138 goto fail;
3139
3140 skb_put_data(*frag, data, count);
3141
3142 len -= count;
3143 data += count;
3144
3145 frag = &(*frag)->next;
3146 }
3147
3148 return skb;
3149
3150 fail:
3151 kfree_skb(skb);
3152 return NULL;
3153 }
3154
l2cap_get_conf_opt(void ** ptr,int * type,int * olen,unsigned long * val)3155 static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen,
3156 unsigned long *val)
3157 {
3158 struct l2cap_conf_opt *opt = *ptr;
3159 int len;
3160
3161 len = L2CAP_CONF_OPT_SIZE + opt->len;
3162 *ptr += len;
3163
3164 *type = opt->type;
3165 *olen = opt->len;
3166
3167 switch (opt->len) {
3168 case 1:
3169 *val = *((u8 *) opt->val);
3170 break;
3171
3172 case 2:
3173 *val = get_unaligned_le16(opt->val);
3174 break;
3175
3176 case 4:
3177 *val = get_unaligned_le32(opt->val);
3178 break;
3179
3180 default:
3181 *val = (unsigned long) opt->val;
3182 break;
3183 }
3184
3185 BT_DBG("type 0x%2.2x len %u val 0x%lx", *type, opt->len, *val);
3186 return len;
3187 }
3188
l2cap_add_conf_opt(void ** ptr,u8 type,u8 len,unsigned long val,size_t size)3189 static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val, size_t size)
3190 {
3191 struct l2cap_conf_opt *opt = *ptr;
3192
3193 BT_DBG("type 0x%2.2x len %u val 0x%lx", type, len, val);
3194
3195 if (size < L2CAP_CONF_OPT_SIZE + len)
3196 return;
3197
3198 opt->type = type;
3199 opt->len = len;
3200
3201 switch (len) {
3202 case 1:
3203 *((u8 *) opt->val) = val;
3204 break;
3205
3206 case 2:
3207 put_unaligned_le16(val, opt->val);
3208 break;
3209
3210 case 4:
3211 put_unaligned_le32(val, opt->val);
3212 break;
3213
3214 default:
3215 memcpy(opt->val, (void *) val, len);
3216 break;
3217 }
3218
3219 *ptr += L2CAP_CONF_OPT_SIZE + len;
3220 }
3221
l2cap_add_opt_efs(void ** ptr,struct l2cap_chan * chan,size_t size)3222 static void l2cap_add_opt_efs(void **ptr, struct l2cap_chan *chan, size_t size)
3223 {
3224 struct l2cap_conf_efs efs;
3225
3226 switch (chan->mode) {
3227 case L2CAP_MODE_ERTM:
3228 efs.id = chan->local_id;
3229 efs.stype = chan->local_stype;
3230 efs.msdu = cpu_to_le16(chan->local_msdu);
3231 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
3232 efs.acc_lat = cpu_to_le32(L2CAP_DEFAULT_ACC_LAT);
3233 efs.flush_to = cpu_to_le32(L2CAP_EFS_DEFAULT_FLUSH_TO);
3234 break;
3235
3236 case L2CAP_MODE_STREAMING:
3237 efs.id = 1;
3238 efs.stype = L2CAP_SERV_BESTEFFORT;
3239 efs.msdu = cpu_to_le16(chan->local_msdu);
3240 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
3241 efs.acc_lat = 0;
3242 efs.flush_to = 0;
3243 break;
3244
3245 default:
3246 return;
3247 }
3248
3249 l2cap_add_conf_opt(ptr, L2CAP_CONF_EFS, sizeof(efs),
3250 (unsigned long) &efs, size);
3251 }
3252
l2cap_ack_timeout(struct work_struct * work)3253 static void l2cap_ack_timeout(struct work_struct *work)
3254 {
3255 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
3256 ack_timer.work);
3257 u16 frames_to_ack;
3258
3259 BT_DBG("chan %p", chan);
3260
3261 l2cap_chan_lock(chan);
3262
3263 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
3264 chan->last_acked_seq);
3265
3266 if (frames_to_ack)
3267 l2cap_send_rr_or_rnr(chan, 0);
3268
3269 l2cap_chan_unlock(chan);
3270 l2cap_chan_put(chan);
3271 }
3272
l2cap_ertm_init(struct l2cap_chan * chan)3273 int l2cap_ertm_init(struct l2cap_chan *chan)
3274 {
3275 int err;
3276
3277 chan->next_tx_seq = 0;
3278 chan->expected_tx_seq = 0;
3279 chan->expected_ack_seq = 0;
3280 chan->unacked_frames = 0;
3281 chan->buffer_seq = 0;
3282 chan->frames_sent = 0;
3283 chan->last_acked_seq = 0;
3284 chan->sdu = NULL;
3285 chan->sdu_last_frag = NULL;
3286 chan->sdu_len = 0;
3287
3288 skb_queue_head_init(&chan->tx_q);
3289
3290 chan->local_amp_id = AMP_ID_BREDR;
3291 chan->move_id = AMP_ID_BREDR;
3292 chan->move_state = L2CAP_MOVE_STABLE;
3293 chan->move_role = L2CAP_MOVE_ROLE_NONE;
3294
3295 if (chan->mode != L2CAP_MODE_ERTM)
3296 return 0;
3297
3298 chan->rx_state = L2CAP_RX_STATE_RECV;
3299 chan->tx_state = L2CAP_TX_STATE_XMIT;
3300
3301 skb_queue_head_init(&chan->srej_q);
3302
3303 err = l2cap_seq_list_init(&chan->srej_list, chan->tx_win);
3304 if (err < 0)
3305 return err;
3306
3307 err = l2cap_seq_list_init(&chan->retrans_list, chan->remote_tx_win);
3308 if (err < 0)
3309 l2cap_seq_list_free(&chan->srej_list);
3310
3311 return err;
3312 }
3313
l2cap_select_mode(__u8 mode,__u16 remote_feat_mask)3314 static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
3315 {
3316 switch (mode) {
3317 case L2CAP_MODE_STREAMING:
3318 case L2CAP_MODE_ERTM:
3319 if (l2cap_mode_supported(mode, remote_feat_mask))
3320 return mode;
3321 fallthrough;
3322 default:
3323 return L2CAP_MODE_BASIC;
3324 }
3325 }
3326
__l2cap_ews_supported(struct l2cap_conn * conn)3327 static inline bool __l2cap_ews_supported(struct l2cap_conn *conn)
3328 {
3329 return ((conn->local_fixed_chan & L2CAP_FC_A2MP) &&
3330 (conn->feat_mask & L2CAP_FEAT_EXT_WINDOW));
3331 }
3332
__l2cap_efs_supported(struct l2cap_conn * conn)3333 static inline bool __l2cap_efs_supported(struct l2cap_conn *conn)
3334 {
3335 return ((conn->local_fixed_chan & L2CAP_FC_A2MP) &&
3336 (conn->feat_mask & L2CAP_FEAT_EXT_FLOW));
3337 }
3338
__l2cap_set_ertm_timeouts(struct l2cap_chan * chan,struct l2cap_conf_rfc * rfc)3339 static void __l2cap_set_ertm_timeouts(struct l2cap_chan *chan,
3340 struct l2cap_conf_rfc *rfc)
3341 {
3342 if (chan->local_amp_id != AMP_ID_BREDR && chan->hs_hcon) {
3343 u64 ertm_to = chan->hs_hcon->hdev->amp_be_flush_to;
3344
3345 /* Class 1 devices have must have ERTM timeouts
3346 * exceeding the Link Supervision Timeout. The
3347 * default Link Supervision Timeout for AMP
3348 * controllers is 10 seconds.
3349 *
3350 * Class 1 devices use 0xffffffff for their
3351 * best-effort flush timeout, so the clamping logic
3352 * will result in a timeout that meets the above
3353 * requirement. ERTM timeouts are 16-bit values, so
3354 * the maximum timeout is 65.535 seconds.
3355 */
3356
3357 /* Convert timeout to milliseconds and round */
3358 ertm_to = DIV_ROUND_UP_ULL(ertm_to, 1000);
3359
3360 /* This is the recommended formula for class 2 devices
3361 * that start ERTM timers when packets are sent to the
3362 * controller.
3363 */
3364 ertm_to = 3 * ertm_to + 500;
3365
3366 if (ertm_to > 0xffff)
3367 ertm_to = 0xffff;
3368
3369 rfc->retrans_timeout = cpu_to_le16((u16) ertm_to);
3370 rfc->monitor_timeout = rfc->retrans_timeout;
3371 } else {
3372 rfc->retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO);
3373 rfc->monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO);
3374 }
3375 }
3376
l2cap_txwin_setup(struct l2cap_chan * chan)3377 static inline void l2cap_txwin_setup(struct l2cap_chan *chan)
3378 {
3379 if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW &&
3380 __l2cap_ews_supported(chan->conn)) {
3381 /* use extended control field */
3382 set_bit(FLAG_EXT_CTRL, &chan->flags);
3383 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
3384 } else {
3385 chan->tx_win = min_t(u16, chan->tx_win,
3386 L2CAP_DEFAULT_TX_WINDOW);
3387 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
3388 }
3389 chan->ack_win = chan->tx_win;
3390 }
3391
l2cap_mtu_auto(struct l2cap_chan * chan)3392 static void l2cap_mtu_auto(struct l2cap_chan *chan)
3393 {
3394 struct hci_conn *conn = chan->conn->hcon;
3395
3396 chan->imtu = L2CAP_DEFAULT_MIN_MTU;
3397
3398 /* The 2-DH1 packet has between 2 and 56 information bytes
3399 * (including the 2-byte payload header)
3400 */
3401 if (!(conn->pkt_type & HCI_2DH1))
3402 chan->imtu = 54;
3403
3404 /* The 3-DH1 packet has between 2 and 85 information bytes
3405 * (including the 2-byte payload header)
3406 */
3407 if (!(conn->pkt_type & HCI_3DH1))
3408 chan->imtu = 83;
3409
3410 /* The 2-DH3 packet has between 2 and 369 information bytes
3411 * (including the 2-byte payload header)
3412 */
3413 if (!(conn->pkt_type & HCI_2DH3))
3414 chan->imtu = 367;
3415
3416 /* The 3-DH3 packet has between 2 and 554 information bytes
3417 * (including the 2-byte payload header)
3418 */
3419 if (!(conn->pkt_type & HCI_3DH3))
3420 chan->imtu = 552;
3421
3422 /* The 2-DH5 packet has between 2 and 681 information bytes
3423 * (including the 2-byte payload header)
3424 */
3425 if (!(conn->pkt_type & HCI_2DH5))
3426 chan->imtu = 679;
3427
3428 /* The 3-DH5 packet has between 2 and 1023 information bytes
3429 * (including the 2-byte payload header)
3430 */
3431 if (!(conn->pkt_type & HCI_3DH5))
3432 chan->imtu = 1021;
3433 }
3434
l2cap_build_conf_req(struct l2cap_chan * chan,void * data,size_t data_size)3435 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
3436 {
3437 struct l2cap_conf_req *req = data;
3438 struct l2cap_conf_rfc rfc = { .mode = chan->mode };
3439 void *ptr = req->data;
3440 void *endptr = data + data_size;
3441 u16 size;
3442
3443 BT_DBG("chan %p", chan);
3444
3445 if (chan->num_conf_req || chan->num_conf_rsp)
3446 goto done;
3447
3448 switch (chan->mode) {
3449 case L2CAP_MODE_STREAMING:
3450 case L2CAP_MODE_ERTM:
3451 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state))
3452 break;
3453
3454 if (__l2cap_efs_supported(chan->conn))
3455 set_bit(FLAG_EFS_ENABLE, &chan->flags);
3456
3457 fallthrough;
3458 default:
3459 chan->mode = l2cap_select_mode(rfc.mode, chan->conn->feat_mask);
3460 break;
3461 }
3462
3463 done:
3464 if (chan->imtu != L2CAP_DEFAULT_MTU) {
3465 if (!chan->imtu)
3466 l2cap_mtu_auto(chan);
3467 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu,
3468 endptr - ptr);
3469 }
3470
3471 switch (chan->mode) {
3472 case L2CAP_MODE_BASIC:
3473 if (disable_ertm)
3474 break;
3475
3476 if (!(chan->conn->feat_mask & L2CAP_FEAT_ERTM) &&
3477 !(chan->conn->feat_mask & L2CAP_FEAT_STREAMING))
3478 break;
3479
3480 rfc.mode = L2CAP_MODE_BASIC;
3481 rfc.txwin_size = 0;
3482 rfc.max_transmit = 0;
3483 rfc.retrans_timeout = 0;
3484 rfc.monitor_timeout = 0;
3485 rfc.max_pdu_size = 0;
3486
3487 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3488 (unsigned long) &rfc, endptr - ptr);
3489 break;
3490
3491 case L2CAP_MODE_ERTM:
3492 rfc.mode = L2CAP_MODE_ERTM;
3493 rfc.max_transmit = chan->max_tx;
3494
3495 __l2cap_set_ertm_timeouts(chan, &rfc);
3496
3497 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3498 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3499 L2CAP_FCS_SIZE);
3500 rfc.max_pdu_size = cpu_to_le16(size);
3501
3502 l2cap_txwin_setup(chan);
3503
3504 rfc.txwin_size = min_t(u16, chan->tx_win,
3505 L2CAP_DEFAULT_TX_WINDOW);
3506
3507 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3508 (unsigned long) &rfc, endptr - ptr);
3509
3510 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3511 l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
3512
3513 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
3514 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3515 chan->tx_win, endptr - ptr);
3516
3517 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3518 if (chan->fcs == L2CAP_FCS_NONE ||
3519 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3520 chan->fcs = L2CAP_FCS_NONE;
3521 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3522 chan->fcs, endptr - ptr);
3523 }
3524 break;
3525
3526 case L2CAP_MODE_STREAMING:
3527 l2cap_txwin_setup(chan);
3528 rfc.mode = L2CAP_MODE_STREAMING;
3529 rfc.txwin_size = 0;
3530 rfc.max_transmit = 0;
3531 rfc.retrans_timeout = 0;
3532 rfc.monitor_timeout = 0;
3533
3534 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3535 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3536 L2CAP_FCS_SIZE);
3537 rfc.max_pdu_size = cpu_to_le16(size);
3538
3539 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3540 (unsigned long) &rfc, endptr - ptr);
3541
3542 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3543 l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
3544
3545 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3546 if (chan->fcs == L2CAP_FCS_NONE ||
3547 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3548 chan->fcs = L2CAP_FCS_NONE;
3549 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3550 chan->fcs, endptr - ptr);
3551 }
3552 break;
3553 }
3554
3555 req->dcid = cpu_to_le16(chan->dcid);
3556 req->flags = cpu_to_le16(0);
3557
3558 return ptr - data;
3559 }
3560
l2cap_parse_conf_req(struct l2cap_chan * chan,void * data,size_t data_size)3561 static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
3562 {
3563 struct l2cap_conf_rsp *rsp = data;
3564 void *ptr = rsp->data;
3565 void *endptr = data + data_size;
3566 void *req = chan->conf_req;
3567 int len = chan->conf_len;
3568 int type, hint, olen;
3569 unsigned long val;
3570 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
3571 struct l2cap_conf_efs efs;
3572 u8 remote_efs = 0;
3573 u16 mtu = L2CAP_DEFAULT_MTU;
3574 u16 result = L2CAP_CONF_SUCCESS;
3575 u16 size;
3576
3577 BT_DBG("chan %p", chan);
3578
3579 while (len >= L2CAP_CONF_OPT_SIZE) {
3580 len -= l2cap_get_conf_opt(&req, &type, &olen, &val);
3581 if (len < 0)
3582 break;
3583
3584 hint = type & L2CAP_CONF_HINT;
3585 type &= L2CAP_CONF_MASK;
3586
3587 switch (type) {
3588 case L2CAP_CONF_MTU:
3589 if (olen != 2)
3590 break;
3591 mtu = val;
3592 break;
3593
3594 case L2CAP_CONF_FLUSH_TO:
3595 if (olen != 2)
3596 break;
3597 chan->flush_to = val;
3598 break;
3599
3600 case L2CAP_CONF_QOS:
3601 break;
3602
3603 case L2CAP_CONF_RFC:
3604 if (olen != sizeof(rfc))
3605 break;
3606 memcpy(&rfc, (void *) val, olen);
3607 break;
3608
3609 case L2CAP_CONF_FCS:
3610 if (olen != 1)
3611 break;
3612 if (val == L2CAP_FCS_NONE)
3613 set_bit(CONF_RECV_NO_FCS, &chan->conf_state);
3614 break;
3615
3616 case L2CAP_CONF_EFS:
3617 if (olen != sizeof(efs))
3618 break;
3619 remote_efs = 1;
3620 memcpy(&efs, (void *) val, olen);
3621 break;
3622
3623 case L2CAP_CONF_EWS:
3624 if (olen != 2)
3625 break;
3626 if (!(chan->conn->local_fixed_chan & L2CAP_FC_A2MP))
3627 return -ECONNREFUSED;
3628 set_bit(FLAG_EXT_CTRL, &chan->flags);
3629 set_bit(CONF_EWS_RECV, &chan->conf_state);
3630 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
3631 chan->remote_tx_win = val;
3632 break;
3633
3634 default:
3635 if (hint)
3636 break;
3637 result = L2CAP_CONF_UNKNOWN;
3638 *((u8 *) ptr++) = type;
3639 break;
3640 }
3641 }
3642
3643 if (chan->num_conf_rsp || chan->num_conf_req > 1)
3644 goto done;
3645
3646 switch (chan->mode) {
3647 case L2CAP_MODE_STREAMING:
3648 case L2CAP_MODE_ERTM:
3649 if (!test_bit(CONF_STATE2_DEVICE, &chan->conf_state)) {
3650 chan->mode = l2cap_select_mode(rfc.mode,
3651 chan->conn->feat_mask);
3652 break;
3653 }
3654
3655 if (remote_efs) {
3656 if (__l2cap_efs_supported(chan->conn))
3657 set_bit(FLAG_EFS_ENABLE, &chan->flags);
3658 else
3659 return -ECONNREFUSED;
3660 }
3661
3662 if (chan->mode != rfc.mode)
3663 return -ECONNREFUSED;
3664
3665 break;
3666 }
3667
3668 done:
3669 if (chan->mode != rfc.mode) {
3670 result = L2CAP_CONF_UNACCEPT;
3671 rfc.mode = chan->mode;
3672
3673 if (chan->num_conf_rsp == 1)
3674 return -ECONNREFUSED;
3675
3676 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3677 (unsigned long) &rfc, endptr - ptr);
3678 }
3679
3680 if (result == L2CAP_CONF_SUCCESS) {
3681 /* Configure output options and let the other side know
3682 * which ones we don't like. */
3683
3684 if (mtu < L2CAP_DEFAULT_MIN_MTU)
3685 result = L2CAP_CONF_UNACCEPT;
3686 else {
3687 chan->omtu = mtu;
3688 set_bit(CONF_MTU_DONE, &chan->conf_state);
3689 }
3690 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->omtu, endptr - ptr);
3691
3692 if (remote_efs) {
3693 if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
3694 efs.stype != L2CAP_SERV_NOTRAFIC &&
3695 efs.stype != chan->local_stype) {
3696
3697 result = L2CAP_CONF_UNACCEPT;
3698
3699 if (chan->num_conf_req >= 1)
3700 return -ECONNREFUSED;
3701
3702 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
3703 sizeof(efs),
3704 (unsigned long) &efs, endptr - ptr);
3705 } else {
3706 /* Send PENDING Conf Rsp */
3707 result = L2CAP_CONF_PENDING;
3708 set_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
3709 }
3710 }
3711
3712 switch (rfc.mode) {
3713 case L2CAP_MODE_BASIC:
3714 chan->fcs = L2CAP_FCS_NONE;
3715 set_bit(CONF_MODE_DONE, &chan->conf_state);
3716 break;
3717
3718 case L2CAP_MODE_ERTM:
3719 if (!test_bit(CONF_EWS_RECV, &chan->conf_state))
3720 chan->remote_tx_win = rfc.txwin_size;
3721 else
3722 rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW;
3723
3724 chan->remote_max_tx = rfc.max_transmit;
3725
3726 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
3727 chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
3728 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
3729 rfc.max_pdu_size = cpu_to_le16(size);
3730 chan->remote_mps = size;
3731
3732 __l2cap_set_ertm_timeouts(chan, &rfc);
3733
3734 set_bit(CONF_MODE_DONE, &chan->conf_state);
3735
3736 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
3737 sizeof(rfc), (unsigned long) &rfc, endptr - ptr);
3738
3739 if (remote_efs &&
3740 test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
3741 chan->remote_id = efs.id;
3742 chan->remote_stype = efs.stype;
3743 chan->remote_msdu = le16_to_cpu(efs.msdu);
3744 chan->remote_flush_to =
3745 le32_to_cpu(efs.flush_to);
3746 chan->remote_acc_lat =
3747 le32_to_cpu(efs.acc_lat);
3748 chan->remote_sdu_itime =
3749 le32_to_cpu(efs.sdu_itime);
3750 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
3751 sizeof(efs),
3752 (unsigned long) &efs, endptr - ptr);
3753 }
3754 break;
3755
3756 case L2CAP_MODE_STREAMING:
3757 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
3758 chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
3759 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
3760 rfc.max_pdu_size = cpu_to_le16(size);
3761 chan->remote_mps = size;
3762
3763 set_bit(CONF_MODE_DONE, &chan->conf_state);
3764
3765 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3766 (unsigned long) &rfc, endptr - ptr);
3767
3768 break;
3769
3770 default:
3771 result = L2CAP_CONF_UNACCEPT;
3772
3773 memset(&rfc, 0, sizeof(rfc));
3774 rfc.mode = chan->mode;
3775 }
3776
3777 if (result == L2CAP_CONF_SUCCESS)
3778 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
3779 }
3780 rsp->scid = cpu_to_le16(chan->dcid);
3781 rsp->result = cpu_to_le16(result);
3782 rsp->flags = cpu_to_le16(0);
3783
3784 return ptr - data;
3785 }
3786
l2cap_parse_conf_rsp(struct l2cap_chan * chan,void * rsp,int len,void * data,size_t size,u16 * result)3787 static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len,
3788 void *data, size_t size, u16 *result)
3789 {
3790 struct l2cap_conf_req *req = data;
3791 void *ptr = req->data;
3792 void *endptr = data + size;
3793 int type, olen;
3794 unsigned long val;
3795 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
3796 struct l2cap_conf_efs efs;
3797
3798 BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data);
3799
3800 while (len >= L2CAP_CONF_OPT_SIZE) {
3801 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
3802 if (len < 0)
3803 break;
3804
3805 switch (type) {
3806 case L2CAP_CONF_MTU:
3807 if (olen != 2)
3808 break;
3809 if (val < L2CAP_DEFAULT_MIN_MTU) {
3810 *result = L2CAP_CONF_UNACCEPT;
3811 chan->imtu = L2CAP_DEFAULT_MIN_MTU;
3812 } else
3813 chan->imtu = val;
3814 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu,
3815 endptr - ptr);
3816 break;
3817
3818 case L2CAP_CONF_FLUSH_TO:
3819 if (olen != 2)
3820 break;
3821 chan->flush_to = val;
3822 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, 2,
3823 chan->flush_to, endptr - ptr);
3824 break;
3825
3826 case L2CAP_CONF_RFC:
3827 if (olen != sizeof(rfc))
3828 break;
3829 memcpy(&rfc, (void *)val, olen);
3830 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state) &&
3831 rfc.mode != chan->mode)
3832 return -ECONNREFUSED;
3833 chan->fcs = 0;
3834 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3835 (unsigned long) &rfc, endptr - ptr);
3836 break;
3837
3838 case L2CAP_CONF_EWS:
3839 if (olen != 2)
3840 break;
3841 chan->ack_win = min_t(u16, val, chan->ack_win);
3842 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3843 chan->tx_win, endptr - ptr);
3844 break;
3845
3846 case L2CAP_CONF_EFS:
3847 if (olen != sizeof(efs))
3848 break;
3849 memcpy(&efs, (void *)val, olen);
3850 if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
3851 efs.stype != L2CAP_SERV_NOTRAFIC &&
3852 efs.stype != chan->local_stype)
3853 return -ECONNREFUSED;
3854 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs),
3855 (unsigned long) &efs, endptr - ptr);
3856 break;
3857
3858 case L2CAP_CONF_FCS:
3859 if (olen != 1)
3860 break;
3861 if (*result == L2CAP_CONF_PENDING)
3862 if (val == L2CAP_FCS_NONE)
3863 set_bit(CONF_RECV_NO_FCS,
3864 &chan->conf_state);
3865 break;
3866 }
3867 }
3868
3869 if (chan->mode == L2CAP_MODE_BASIC && chan->mode != rfc.mode)
3870 return -ECONNREFUSED;
3871
3872 chan->mode = rfc.mode;
3873
3874 if (*result == L2CAP_CONF_SUCCESS || *result == L2CAP_CONF_PENDING) {
3875 switch (rfc.mode) {
3876 case L2CAP_MODE_ERTM:
3877 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
3878 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
3879 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3880 if (!test_bit(FLAG_EXT_CTRL, &chan->flags))
3881 chan->ack_win = min_t(u16, chan->ack_win,
3882 rfc.txwin_size);
3883
3884 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
3885 chan->local_msdu = le16_to_cpu(efs.msdu);
3886 chan->local_sdu_itime =
3887 le32_to_cpu(efs.sdu_itime);
3888 chan->local_acc_lat = le32_to_cpu(efs.acc_lat);
3889 chan->local_flush_to =
3890 le32_to_cpu(efs.flush_to);
3891 }
3892 break;
3893
3894 case L2CAP_MODE_STREAMING:
3895 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3896 }
3897 }
3898
3899 req->dcid = cpu_to_le16(chan->dcid);
3900 req->flags = cpu_to_le16(0);
3901
3902 return ptr - data;
3903 }
3904
l2cap_build_conf_rsp(struct l2cap_chan * chan,void * data,u16 result,u16 flags)3905 static int l2cap_build_conf_rsp(struct l2cap_chan *chan, void *data,
3906 u16 result, u16 flags)
3907 {
3908 struct l2cap_conf_rsp *rsp = data;
3909 void *ptr = rsp->data;
3910
3911 BT_DBG("chan %p", chan);
3912
3913 rsp->scid = cpu_to_le16(chan->dcid);
3914 rsp->result = cpu_to_le16(result);
3915 rsp->flags = cpu_to_le16(flags);
3916
3917 return ptr - data;
3918 }
3919
__l2cap_le_connect_rsp_defer(struct l2cap_chan * chan)3920 void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan)
3921 {
3922 struct l2cap_le_conn_rsp rsp;
3923 struct l2cap_conn *conn = chan->conn;
3924
3925 BT_DBG("chan %p", chan);
3926
3927 rsp.dcid = cpu_to_le16(chan->scid);
3928 rsp.mtu = cpu_to_le16(chan->imtu);
3929 rsp.mps = cpu_to_le16(chan->mps);
3930 rsp.credits = cpu_to_le16(chan->rx_credits);
3931 rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS);
3932
3933 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
3934 &rsp);
3935 }
3936
l2cap_ecred_list_defer(struct l2cap_chan * chan,void * data)3937 static void l2cap_ecred_list_defer(struct l2cap_chan *chan, void *data)
3938 {
3939 int *result = data;
3940
3941 if (*result || test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
3942 return;
3943
3944 switch (chan->state) {
3945 case BT_CONNECT2:
3946 /* If channel still pending accept add to result */
3947 (*result)++;
3948 return;
3949 case BT_CONNECTED:
3950 return;
3951 default:
3952 /* If not connected or pending accept it has been refused */
3953 *result = -ECONNREFUSED;
3954 return;
3955 }
3956 }
3957
3958 struct l2cap_ecred_rsp_data {
3959 struct {
3960 struct l2cap_ecred_conn_rsp rsp;
3961 __le16 scid[L2CAP_ECRED_MAX_CID];
3962 } __packed pdu;
3963 int count;
3964 };
3965
l2cap_ecred_rsp_defer(struct l2cap_chan * chan,void * data)3966 static void l2cap_ecred_rsp_defer(struct l2cap_chan *chan, void *data)
3967 {
3968 struct l2cap_ecred_rsp_data *rsp = data;
3969
3970 if (test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
3971 return;
3972
3973 /* Reset ident so only one response is sent */
3974 chan->ident = 0;
3975
3976 /* Include all channels pending with the same ident */
3977 if (!rsp->pdu.rsp.result)
3978 rsp->pdu.rsp.dcid[rsp->count++] = cpu_to_le16(chan->scid);
3979 else
3980 l2cap_chan_del(chan, ECONNRESET);
3981 }
3982
__l2cap_ecred_conn_rsp_defer(struct l2cap_chan * chan)3983 void __l2cap_ecred_conn_rsp_defer(struct l2cap_chan *chan)
3984 {
3985 struct l2cap_conn *conn = chan->conn;
3986 struct l2cap_ecred_rsp_data data;
3987 u16 id = chan->ident;
3988 int result = 0;
3989
3990 if (!id)
3991 return;
3992
3993 BT_DBG("chan %p id %d", chan, id);
3994
3995 memset(&data, 0, sizeof(data));
3996
3997 data.pdu.rsp.mtu = cpu_to_le16(chan->imtu);
3998 data.pdu.rsp.mps = cpu_to_le16(chan->mps);
3999 data.pdu.rsp.credits = cpu_to_le16(chan->rx_credits);
4000 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS);
4001
4002 /* Verify that all channels are ready */
4003 __l2cap_chan_list_id(conn, id, l2cap_ecred_list_defer, &result);
4004
4005 if (result > 0)
4006 return;
4007
4008 if (result < 0)
4009 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_AUTHORIZATION);
4010
4011 /* Build response */
4012 __l2cap_chan_list_id(conn, id, l2cap_ecred_rsp_defer, &data);
4013
4014 l2cap_send_cmd(conn, id, L2CAP_ECRED_CONN_RSP,
4015 sizeof(data.pdu.rsp) + (data.count * sizeof(__le16)),
4016 &data.pdu);
4017 }
4018
__l2cap_connect_rsp_defer(struct l2cap_chan * chan)4019 void __l2cap_connect_rsp_defer(struct l2cap_chan *chan)
4020 {
4021 struct l2cap_conn_rsp rsp;
4022 struct l2cap_conn *conn = chan->conn;
4023 u8 buf[128];
4024 u8 rsp_code;
4025
4026 rsp.scid = cpu_to_le16(chan->dcid);
4027 rsp.dcid = cpu_to_le16(chan->scid);
4028 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
4029 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
4030
4031 if (chan->hs_hcon)
4032 rsp_code = L2CAP_CREATE_CHAN_RSP;
4033 else
4034 rsp_code = L2CAP_CONN_RSP;
4035
4036 BT_DBG("chan %p rsp_code %u", chan, rsp_code);
4037
4038 l2cap_send_cmd(conn, chan->ident, rsp_code, sizeof(rsp), &rsp);
4039
4040 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
4041 return;
4042
4043 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4044 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4045 chan->num_conf_req++;
4046 }
4047
l2cap_conf_rfc_get(struct l2cap_chan * chan,void * rsp,int len)4048 static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len)
4049 {
4050 int type, olen;
4051 unsigned long val;
4052 /* Use sane default values in case a misbehaving remote device
4053 * did not send an RFC or extended window size option.
4054 */
4055 u16 txwin_ext = chan->ack_win;
4056 struct l2cap_conf_rfc rfc = {
4057 .mode = chan->mode,
4058 .retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO),
4059 .monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO),
4060 .max_pdu_size = cpu_to_le16(chan->imtu),
4061 .txwin_size = min_t(u16, chan->ack_win, L2CAP_DEFAULT_TX_WINDOW),
4062 };
4063
4064 BT_DBG("chan %p, rsp %p, len %d", chan, rsp, len);
4065
4066 if ((chan->mode != L2CAP_MODE_ERTM) && (chan->mode != L2CAP_MODE_STREAMING))
4067 return;
4068
4069 while (len >= L2CAP_CONF_OPT_SIZE) {
4070 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
4071 if (len < 0)
4072 break;
4073
4074 switch (type) {
4075 case L2CAP_CONF_RFC:
4076 if (olen != sizeof(rfc))
4077 break;
4078 memcpy(&rfc, (void *)val, olen);
4079 break;
4080 case L2CAP_CONF_EWS:
4081 if (olen != 2)
4082 break;
4083 txwin_ext = val;
4084 break;
4085 }
4086 }
4087
4088 switch (rfc.mode) {
4089 case L2CAP_MODE_ERTM:
4090 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
4091 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
4092 chan->mps = le16_to_cpu(rfc.max_pdu_size);
4093 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
4094 chan->ack_win = min_t(u16, chan->ack_win, txwin_ext);
4095 else
4096 chan->ack_win = min_t(u16, chan->ack_win,
4097 rfc.txwin_size);
4098 break;
4099 case L2CAP_MODE_STREAMING:
4100 chan->mps = le16_to_cpu(rfc.max_pdu_size);
4101 }
4102 }
4103
l2cap_command_rej(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4104 static inline int l2cap_command_rej(struct l2cap_conn *conn,
4105 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4106 u8 *data)
4107 {
4108 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
4109
4110 if (cmd_len < sizeof(*rej))
4111 return -EPROTO;
4112
4113 if (rej->reason != L2CAP_REJ_NOT_UNDERSTOOD)
4114 return 0;
4115
4116 if ((conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) &&
4117 cmd->ident == conn->info_ident) {
4118 cancel_delayed_work(&conn->info_timer);
4119
4120 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4121 conn->info_ident = 0;
4122
4123 l2cap_conn_start(conn);
4124 }
4125
4126 return 0;
4127 }
4128
l2cap_connect(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u8 * data,u8 rsp_code,u8 amp_id)4129 static struct l2cap_chan *l2cap_connect(struct l2cap_conn *conn,
4130 struct l2cap_cmd_hdr *cmd,
4131 u8 *data, u8 rsp_code, u8 amp_id)
4132 {
4133 struct l2cap_conn_req *req = (struct l2cap_conn_req *) data;
4134 struct l2cap_conn_rsp rsp;
4135 struct l2cap_chan *chan = NULL, *pchan;
4136 int result, status = L2CAP_CS_NO_INFO;
4137
4138 u16 dcid = 0, scid = __le16_to_cpu(req->scid);
4139 __le16 psm = req->psm;
4140
4141 BT_DBG("psm 0x%2.2x scid 0x%4.4x", __le16_to_cpu(psm), scid);
4142
4143 /* Check if we have socket listening on psm */
4144 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
4145 &conn->hcon->dst, ACL_LINK);
4146 if (!pchan) {
4147 result = L2CAP_CR_BAD_PSM;
4148 goto sendresp;
4149 }
4150
4151 mutex_lock(&conn->chan_lock);
4152 l2cap_chan_lock(pchan);
4153
4154 /* Check if the ACL is secure enough (if not SDP) */
4155 if (psm != cpu_to_le16(L2CAP_PSM_SDP) &&
4156 !hci_conn_check_link_mode(conn->hcon)) {
4157 conn->disc_reason = HCI_ERROR_AUTH_FAILURE;
4158 result = L2CAP_CR_SEC_BLOCK;
4159 goto response;
4160 }
4161
4162 result = L2CAP_CR_NO_MEM;
4163
4164 /* Check for valid dynamic CID range (as per Erratum 3253) */
4165 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) {
4166 result = L2CAP_CR_INVALID_SCID;
4167 goto response;
4168 }
4169
4170 /* Check if we already have channel with that dcid */
4171 if (__l2cap_get_chan_by_dcid(conn, scid)) {
4172 result = L2CAP_CR_SCID_IN_USE;
4173 goto response;
4174 }
4175
4176 chan = pchan->ops->new_connection(pchan);
4177 if (!chan)
4178 goto response;
4179
4180 /* For certain devices (ex: HID mouse), support for authentication,
4181 * pairing and bonding is optional. For such devices, inorder to avoid
4182 * the ACL alive for too long after L2CAP disconnection, reset the ACL
4183 * disc_timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect.
4184 */
4185 conn->hcon->disc_timeout = HCI_DISCONN_TIMEOUT;
4186
4187 bacpy(&chan->src, &conn->hcon->src);
4188 bacpy(&chan->dst, &conn->hcon->dst);
4189 chan->src_type = bdaddr_src_type(conn->hcon);
4190 chan->dst_type = bdaddr_dst_type(conn->hcon);
4191 chan->psm = psm;
4192 chan->dcid = scid;
4193 chan->local_amp_id = amp_id;
4194
4195 __l2cap_chan_add(conn, chan);
4196
4197 dcid = chan->scid;
4198
4199 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
4200
4201 chan->ident = cmd->ident;
4202
4203 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) {
4204 if (l2cap_chan_check_security(chan, false)) {
4205 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
4206 l2cap_state_change(chan, BT_CONNECT2);
4207 result = L2CAP_CR_PEND;
4208 status = L2CAP_CS_AUTHOR_PEND;
4209 chan->ops->defer(chan);
4210 } else {
4211 /* Force pending result for AMP controllers.
4212 * The connection will succeed after the
4213 * physical link is up.
4214 */
4215 if (amp_id == AMP_ID_BREDR) {
4216 l2cap_state_change(chan, BT_CONFIG);
4217 result = L2CAP_CR_SUCCESS;
4218 } else {
4219 l2cap_state_change(chan, BT_CONNECT2);
4220 result = L2CAP_CR_PEND;
4221 }
4222 status = L2CAP_CS_NO_INFO;
4223 }
4224 } else {
4225 l2cap_state_change(chan, BT_CONNECT2);
4226 result = L2CAP_CR_PEND;
4227 status = L2CAP_CS_AUTHEN_PEND;
4228 }
4229 } else {
4230 l2cap_state_change(chan, BT_CONNECT2);
4231 result = L2CAP_CR_PEND;
4232 status = L2CAP_CS_NO_INFO;
4233 }
4234
4235 response:
4236 l2cap_chan_unlock(pchan);
4237 mutex_unlock(&conn->chan_lock);
4238 l2cap_chan_put(pchan);
4239
4240 sendresp:
4241 rsp.scid = cpu_to_le16(scid);
4242 rsp.dcid = cpu_to_le16(dcid);
4243 rsp.result = cpu_to_le16(result);
4244 rsp.status = cpu_to_le16(status);
4245 l2cap_send_cmd(conn, cmd->ident, rsp_code, sizeof(rsp), &rsp);
4246
4247 if (result == L2CAP_CR_PEND && status == L2CAP_CS_NO_INFO) {
4248 struct l2cap_info_req info;
4249 info.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
4250
4251 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
4252 conn->info_ident = l2cap_get_ident(conn);
4253
4254 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
4255
4256 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
4257 sizeof(info), &info);
4258 }
4259
4260 if (chan && !test_bit(CONF_REQ_SENT, &chan->conf_state) &&
4261 result == L2CAP_CR_SUCCESS) {
4262 u8 buf[128];
4263 set_bit(CONF_REQ_SENT, &chan->conf_state);
4264 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4265 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4266 chan->num_conf_req++;
4267 }
4268
4269 return chan;
4270 }
4271
l2cap_connect_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4272 static int l2cap_connect_req(struct l2cap_conn *conn,
4273 struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
4274 {
4275 struct hci_dev *hdev = conn->hcon->hdev;
4276 struct hci_conn *hcon = conn->hcon;
4277
4278 if (cmd_len < sizeof(struct l2cap_conn_req))
4279 return -EPROTO;
4280
4281 hci_dev_lock(hdev);
4282 if (hci_dev_test_flag(hdev, HCI_MGMT) &&
4283 !test_and_set_bit(HCI_CONN_MGMT_CONNECTED, &hcon->flags))
4284 mgmt_device_connected(hdev, hcon, 0, NULL, 0);
4285 hci_dev_unlock(hdev);
4286
4287 l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP, 0);
4288 return 0;
4289 }
4290
l2cap_connect_create_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4291 static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
4292 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4293 u8 *data)
4294 {
4295 struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data;
4296 u16 scid, dcid, result, status;
4297 struct l2cap_chan *chan;
4298 u8 req[128];
4299 int err;
4300
4301 if (cmd_len < sizeof(*rsp))
4302 return -EPROTO;
4303
4304 scid = __le16_to_cpu(rsp->scid);
4305 dcid = __le16_to_cpu(rsp->dcid);
4306 result = __le16_to_cpu(rsp->result);
4307 status = __le16_to_cpu(rsp->status);
4308
4309 if (result == L2CAP_CR_SUCCESS && (dcid < L2CAP_CID_DYN_START ||
4310 dcid > L2CAP_CID_DYN_END))
4311 return -EPROTO;
4312
4313 BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x",
4314 dcid, scid, result, status);
4315
4316 mutex_lock(&conn->chan_lock);
4317
4318 if (scid) {
4319 chan = __l2cap_get_chan_by_scid(conn, scid);
4320 if (!chan) {
4321 err = -EBADSLT;
4322 goto unlock;
4323 }
4324 } else {
4325 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
4326 if (!chan) {
4327 err = -EBADSLT;
4328 goto unlock;
4329 }
4330 }
4331
4332 chan = l2cap_chan_hold_unless_zero(chan);
4333 if (!chan) {
4334 err = -EBADSLT;
4335 goto unlock;
4336 }
4337
4338 err = 0;
4339
4340 l2cap_chan_lock(chan);
4341
4342 switch (result) {
4343 case L2CAP_CR_SUCCESS:
4344 if (__l2cap_get_chan_by_dcid(conn, dcid)) {
4345 err = -EBADSLT;
4346 break;
4347 }
4348
4349 l2cap_state_change(chan, BT_CONFIG);
4350 chan->ident = 0;
4351 chan->dcid = dcid;
4352 clear_bit(CONF_CONNECT_PEND, &chan->conf_state);
4353
4354 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
4355 break;
4356
4357 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4358 l2cap_build_conf_req(chan, req, sizeof(req)), req);
4359 chan->num_conf_req++;
4360 break;
4361
4362 case L2CAP_CR_PEND:
4363 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
4364 break;
4365
4366 default:
4367 l2cap_chan_del(chan, ECONNREFUSED);
4368 break;
4369 }
4370
4371 l2cap_chan_unlock(chan);
4372 l2cap_chan_put(chan);
4373
4374 unlock:
4375 mutex_unlock(&conn->chan_lock);
4376
4377 return err;
4378 }
4379
set_default_fcs(struct l2cap_chan * chan)4380 static inline void set_default_fcs(struct l2cap_chan *chan)
4381 {
4382 /* FCS is enabled only in ERTM or streaming mode, if one or both
4383 * sides request it.
4384 */
4385 if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING)
4386 chan->fcs = L2CAP_FCS_NONE;
4387 else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state))
4388 chan->fcs = L2CAP_FCS_CRC16;
4389 }
4390
l2cap_send_efs_conf_rsp(struct l2cap_chan * chan,void * data,u8 ident,u16 flags)4391 static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data,
4392 u8 ident, u16 flags)
4393 {
4394 struct l2cap_conn *conn = chan->conn;
4395
4396 BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident,
4397 flags);
4398
4399 clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
4400 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
4401
4402 l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP,
4403 l2cap_build_conf_rsp(chan, data,
4404 L2CAP_CONF_SUCCESS, flags), data);
4405 }
4406
cmd_reject_invalid_cid(struct l2cap_conn * conn,u8 ident,u16 scid,u16 dcid)4407 static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident,
4408 u16 scid, u16 dcid)
4409 {
4410 struct l2cap_cmd_rej_cid rej;
4411
4412 rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID);
4413 rej.scid = __cpu_to_le16(scid);
4414 rej.dcid = __cpu_to_le16(dcid);
4415
4416 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
4417 }
4418
l2cap_config_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4419 static inline int l2cap_config_req(struct l2cap_conn *conn,
4420 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4421 u8 *data)
4422 {
4423 struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
4424 u16 dcid, flags;
4425 u8 rsp[64];
4426 struct l2cap_chan *chan;
4427 int len, err = 0;
4428
4429 if (cmd_len < sizeof(*req))
4430 return -EPROTO;
4431
4432 dcid = __le16_to_cpu(req->dcid);
4433 flags = __le16_to_cpu(req->flags);
4434
4435 BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags);
4436
4437 chan = l2cap_get_chan_by_scid(conn, dcid);
4438 if (!chan) {
4439 cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0);
4440 return 0;
4441 }
4442
4443 if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2 &&
4444 chan->state != BT_CONNECTED) {
4445 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
4446 chan->dcid);
4447 goto unlock;
4448 }
4449
4450 /* Reject if config buffer is too small. */
4451 len = cmd_len - sizeof(*req);
4452 if (chan->conf_len + len > sizeof(chan->conf_req)) {
4453 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4454 l2cap_build_conf_rsp(chan, rsp,
4455 L2CAP_CONF_REJECT, flags), rsp);
4456 goto unlock;
4457 }
4458
4459 /* Store config. */
4460 memcpy(chan->conf_req + chan->conf_len, req->data, len);
4461 chan->conf_len += len;
4462
4463 if (flags & L2CAP_CONF_FLAG_CONTINUATION) {
4464 /* Incomplete config. Send empty response. */
4465 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4466 l2cap_build_conf_rsp(chan, rsp,
4467 L2CAP_CONF_SUCCESS, flags), rsp);
4468 goto unlock;
4469 }
4470
4471 /* Complete config. */
4472 len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp));
4473 if (len < 0) {
4474 l2cap_send_disconn_req(chan, ECONNRESET);
4475 goto unlock;
4476 }
4477
4478 chan->ident = cmd->ident;
4479 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp);
4480 if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP)
4481 chan->num_conf_rsp++;
4482
4483 /* Reset config buffer. */
4484 chan->conf_len = 0;
4485
4486 if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state))
4487 goto unlock;
4488
4489 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
4490 set_default_fcs(chan);
4491
4492 if (chan->mode == L2CAP_MODE_ERTM ||
4493 chan->mode == L2CAP_MODE_STREAMING)
4494 err = l2cap_ertm_init(chan);
4495
4496 if (err < 0)
4497 l2cap_send_disconn_req(chan, -err);
4498 else
4499 l2cap_chan_ready(chan);
4500
4501 goto unlock;
4502 }
4503
4504 if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) {
4505 u8 buf[64];
4506 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4507 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4508 chan->num_conf_req++;
4509 }
4510
4511 /* Got Conf Rsp PENDING from remote side and assume we sent
4512 Conf Rsp PENDING in the code above */
4513 if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) &&
4514 test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4515
4516 /* check compatibility */
4517
4518 /* Send rsp for BR/EDR channel */
4519 if (!chan->hs_hcon)
4520 l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags);
4521 else
4522 chan->ident = cmd->ident;
4523 }
4524
4525 unlock:
4526 l2cap_chan_unlock(chan);
4527 l2cap_chan_put(chan);
4528 return err;
4529 }
4530
l2cap_config_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4531 static inline int l2cap_config_rsp(struct l2cap_conn *conn,
4532 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4533 u8 *data)
4534 {
4535 struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data;
4536 u16 scid, flags, result;
4537 struct l2cap_chan *chan;
4538 int len = cmd_len - sizeof(*rsp);
4539 int err = 0;
4540
4541 if (cmd_len < sizeof(*rsp))
4542 return -EPROTO;
4543
4544 scid = __le16_to_cpu(rsp->scid);
4545 flags = __le16_to_cpu(rsp->flags);
4546 result = __le16_to_cpu(rsp->result);
4547
4548 BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags,
4549 result, len);
4550
4551 chan = l2cap_get_chan_by_scid(conn, scid);
4552 if (!chan)
4553 return 0;
4554
4555 switch (result) {
4556 case L2CAP_CONF_SUCCESS:
4557 l2cap_conf_rfc_get(chan, rsp->data, len);
4558 clear_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4559 break;
4560
4561 case L2CAP_CONF_PENDING:
4562 set_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4563
4564 if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4565 char buf[64];
4566
4567 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4568 buf, sizeof(buf), &result);
4569 if (len < 0) {
4570 l2cap_send_disconn_req(chan, ECONNRESET);
4571 goto done;
4572 }
4573
4574 if (!chan->hs_hcon) {
4575 l2cap_send_efs_conf_rsp(chan, buf, cmd->ident,
4576 0);
4577 } else {
4578 if (l2cap_check_efs(chan)) {
4579 amp_create_logical_link(chan);
4580 chan->ident = cmd->ident;
4581 }
4582 }
4583 }
4584 goto done;
4585
4586 case L2CAP_CONF_UNACCEPT:
4587 if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) {
4588 char req[64];
4589
4590 if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) {
4591 l2cap_send_disconn_req(chan, ECONNRESET);
4592 goto done;
4593 }
4594
4595 /* throw out any old stored conf requests */
4596 result = L2CAP_CONF_SUCCESS;
4597 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4598 req, sizeof(req), &result);
4599 if (len < 0) {
4600 l2cap_send_disconn_req(chan, ECONNRESET);
4601 goto done;
4602 }
4603
4604 l2cap_send_cmd(conn, l2cap_get_ident(conn),
4605 L2CAP_CONF_REQ, len, req);
4606 chan->num_conf_req++;
4607 if (result != L2CAP_CONF_SUCCESS)
4608 goto done;
4609 break;
4610 }
4611 fallthrough;
4612
4613 default:
4614 l2cap_chan_set_err(chan, ECONNRESET);
4615
4616 __set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT);
4617 l2cap_send_disconn_req(chan, ECONNRESET);
4618 goto done;
4619 }
4620
4621 if (flags & L2CAP_CONF_FLAG_CONTINUATION)
4622 goto done;
4623
4624 set_bit(CONF_INPUT_DONE, &chan->conf_state);
4625
4626 if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) {
4627 set_default_fcs(chan);
4628
4629 if (chan->mode == L2CAP_MODE_ERTM ||
4630 chan->mode == L2CAP_MODE_STREAMING)
4631 err = l2cap_ertm_init(chan);
4632
4633 if (err < 0)
4634 l2cap_send_disconn_req(chan, -err);
4635 else
4636 l2cap_chan_ready(chan);
4637 }
4638
4639 done:
4640 l2cap_chan_unlock(chan);
4641 l2cap_chan_put(chan);
4642 return err;
4643 }
4644
l2cap_disconnect_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4645 static inline int l2cap_disconnect_req(struct l2cap_conn *conn,
4646 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4647 u8 *data)
4648 {
4649 struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data;
4650 struct l2cap_disconn_rsp rsp;
4651 u16 dcid, scid;
4652 struct l2cap_chan *chan;
4653
4654 if (cmd_len != sizeof(*req))
4655 return -EPROTO;
4656
4657 scid = __le16_to_cpu(req->scid);
4658 dcid = __le16_to_cpu(req->dcid);
4659
4660 BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
4661
4662 chan = l2cap_get_chan_by_scid(conn, dcid);
4663 if (!chan) {
4664 cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid);
4665 return 0;
4666 }
4667
4668 rsp.dcid = cpu_to_le16(chan->scid);
4669 rsp.scid = cpu_to_le16(chan->dcid);
4670 l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
4671
4672 chan->ops->set_shutdown(chan);
4673
4674 l2cap_chan_unlock(chan);
4675 mutex_lock(&conn->chan_lock);
4676 l2cap_chan_lock(chan);
4677 l2cap_chan_del(chan, ECONNRESET);
4678 mutex_unlock(&conn->chan_lock);
4679
4680 chan->ops->close(chan);
4681
4682 l2cap_chan_unlock(chan);
4683 l2cap_chan_put(chan);
4684
4685 return 0;
4686 }
4687
l2cap_disconnect_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4688 static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,
4689 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4690 u8 *data)
4691 {
4692 struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data;
4693 u16 dcid, scid;
4694 struct l2cap_chan *chan;
4695
4696 if (cmd_len != sizeof(*rsp))
4697 return -EPROTO;
4698
4699 scid = __le16_to_cpu(rsp->scid);
4700 dcid = __le16_to_cpu(rsp->dcid);
4701
4702 BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
4703
4704 chan = l2cap_get_chan_by_scid(conn, scid);
4705 if (!chan) {
4706 return 0;
4707 }
4708
4709 if (chan->state != BT_DISCONN) {
4710 l2cap_chan_unlock(chan);
4711 l2cap_chan_put(chan);
4712 return 0;
4713 }
4714
4715 l2cap_chan_unlock(chan);
4716 mutex_lock(&conn->chan_lock);
4717 l2cap_chan_lock(chan);
4718 l2cap_chan_del(chan, 0);
4719 mutex_unlock(&conn->chan_lock);
4720
4721 chan->ops->close(chan);
4722
4723 l2cap_chan_unlock(chan);
4724 l2cap_chan_put(chan);
4725
4726 return 0;
4727 }
4728
l2cap_information_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4729 static inline int l2cap_information_req(struct l2cap_conn *conn,
4730 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4731 u8 *data)
4732 {
4733 struct l2cap_info_req *req = (struct l2cap_info_req *) data;
4734 u16 type;
4735
4736 if (cmd_len != sizeof(*req))
4737 return -EPROTO;
4738
4739 type = __le16_to_cpu(req->type);
4740
4741 BT_DBG("type 0x%4.4x", type);
4742
4743 if (type == L2CAP_IT_FEAT_MASK) {
4744 u8 buf[8];
4745 u32 feat_mask = l2cap_feat_mask;
4746 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4747 rsp->type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
4748 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4749 if (!disable_ertm)
4750 feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING
4751 | L2CAP_FEAT_FCS;
4752 if (conn->local_fixed_chan & L2CAP_FC_A2MP)
4753 feat_mask |= L2CAP_FEAT_EXT_FLOW
4754 | L2CAP_FEAT_EXT_WINDOW;
4755
4756 put_unaligned_le32(feat_mask, rsp->data);
4757 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4758 buf);
4759 } else if (type == L2CAP_IT_FIXED_CHAN) {
4760 u8 buf[12];
4761 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4762
4763 rsp->type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4764 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4765 rsp->data[0] = conn->local_fixed_chan;
4766 memset(rsp->data + 1, 0, 7);
4767 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4768 buf);
4769 } else {
4770 struct l2cap_info_rsp rsp;
4771 rsp.type = cpu_to_le16(type);
4772 rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP);
4773 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp),
4774 &rsp);
4775 }
4776
4777 return 0;
4778 }
4779
l2cap_information_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4780 static inline int l2cap_information_rsp(struct l2cap_conn *conn,
4781 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4782 u8 *data)
4783 {
4784 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data;
4785 u16 type, result;
4786
4787 if (cmd_len < sizeof(*rsp))
4788 return -EPROTO;
4789
4790 type = __le16_to_cpu(rsp->type);
4791 result = __le16_to_cpu(rsp->result);
4792
4793 BT_DBG("type 0x%4.4x result 0x%2.2x", type, result);
4794
4795 /* L2CAP Info req/rsp are unbound to channels, add extra checks */
4796 if (cmd->ident != conn->info_ident ||
4797 conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
4798 return 0;
4799
4800 cancel_delayed_work(&conn->info_timer);
4801
4802 if (result != L2CAP_IR_SUCCESS) {
4803 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4804 conn->info_ident = 0;
4805
4806 l2cap_conn_start(conn);
4807
4808 return 0;
4809 }
4810
4811 switch (type) {
4812 case L2CAP_IT_FEAT_MASK:
4813 conn->feat_mask = get_unaligned_le32(rsp->data);
4814
4815 if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) {
4816 struct l2cap_info_req req;
4817 req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4818
4819 conn->info_ident = l2cap_get_ident(conn);
4820
4821 l2cap_send_cmd(conn, conn->info_ident,
4822 L2CAP_INFO_REQ, sizeof(req), &req);
4823 } else {
4824 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4825 conn->info_ident = 0;
4826
4827 l2cap_conn_start(conn);
4828 }
4829 break;
4830
4831 case L2CAP_IT_FIXED_CHAN:
4832 conn->remote_fixed_chan = rsp->data[0];
4833 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4834 conn->info_ident = 0;
4835
4836 l2cap_conn_start(conn);
4837 break;
4838 }
4839
4840 return 0;
4841 }
4842
l2cap_create_channel_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,void * data)4843 static int l2cap_create_channel_req(struct l2cap_conn *conn,
4844 struct l2cap_cmd_hdr *cmd,
4845 u16 cmd_len, void *data)
4846 {
4847 struct l2cap_create_chan_req *req = data;
4848 struct l2cap_create_chan_rsp rsp;
4849 struct l2cap_chan *chan;
4850 struct hci_dev *hdev;
4851 u16 psm, scid;
4852
4853 if (cmd_len != sizeof(*req))
4854 return -EPROTO;
4855
4856 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
4857 return -EINVAL;
4858
4859 psm = le16_to_cpu(req->psm);
4860 scid = le16_to_cpu(req->scid);
4861
4862 BT_DBG("psm 0x%2.2x, scid 0x%4.4x, amp_id %d", psm, scid, req->amp_id);
4863
4864 /* For controller id 0 make BR/EDR connection */
4865 if (req->amp_id == AMP_ID_BREDR) {
4866 l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP,
4867 req->amp_id);
4868 return 0;
4869 }
4870
4871 /* Validate AMP controller id */
4872 hdev = hci_dev_get(req->amp_id);
4873 if (!hdev)
4874 goto error;
4875
4876 if (hdev->dev_type != HCI_AMP || !test_bit(HCI_UP, &hdev->flags)) {
4877 hci_dev_put(hdev);
4878 goto error;
4879 }
4880
4881 chan = l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP,
4882 req->amp_id);
4883 if (chan) {
4884 struct amp_mgr *mgr = conn->hcon->amp_mgr;
4885 struct hci_conn *hs_hcon;
4886
4887 hs_hcon = hci_conn_hash_lookup_ba(hdev, AMP_LINK,
4888 &conn->hcon->dst);
4889 if (!hs_hcon) {
4890 hci_dev_put(hdev);
4891 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
4892 chan->dcid);
4893 return 0;
4894 }
4895
4896 BT_DBG("mgr %p bredr_chan %p hs_hcon %p", mgr, chan, hs_hcon);
4897
4898 mgr->bredr_chan = chan;
4899 chan->hs_hcon = hs_hcon;
4900 chan->fcs = L2CAP_FCS_NONE;
4901 conn->mtu = hdev->block_mtu;
4902 }
4903
4904 hci_dev_put(hdev);
4905
4906 return 0;
4907
4908 error:
4909 rsp.dcid = 0;
4910 rsp.scid = cpu_to_le16(scid);
4911 rsp.result = cpu_to_le16(L2CAP_CR_BAD_AMP);
4912 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
4913
4914 l2cap_send_cmd(conn, cmd->ident, L2CAP_CREATE_CHAN_RSP,
4915 sizeof(rsp), &rsp);
4916
4917 return 0;
4918 }
4919
l2cap_send_move_chan_req(struct l2cap_chan * chan,u8 dest_amp_id)4920 static void l2cap_send_move_chan_req(struct l2cap_chan *chan, u8 dest_amp_id)
4921 {
4922 struct l2cap_move_chan_req req;
4923 u8 ident;
4924
4925 BT_DBG("chan %p, dest_amp_id %d", chan, dest_amp_id);
4926
4927 ident = l2cap_get_ident(chan->conn);
4928 chan->ident = ident;
4929
4930 req.icid = cpu_to_le16(chan->scid);
4931 req.dest_amp_id = dest_amp_id;
4932
4933 l2cap_send_cmd(chan->conn, ident, L2CAP_MOVE_CHAN_REQ, sizeof(req),
4934 &req);
4935
4936 __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
4937 }
4938
l2cap_send_move_chan_rsp(struct l2cap_chan * chan,u16 result)4939 static void l2cap_send_move_chan_rsp(struct l2cap_chan *chan, u16 result)
4940 {
4941 struct l2cap_move_chan_rsp rsp;
4942
4943 BT_DBG("chan %p, result 0x%4.4x", chan, result);
4944
4945 rsp.icid = cpu_to_le16(chan->dcid);
4946 rsp.result = cpu_to_le16(result);
4947
4948 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_RSP,
4949 sizeof(rsp), &rsp);
4950 }
4951
l2cap_send_move_chan_cfm(struct l2cap_chan * chan,u16 result)4952 static void l2cap_send_move_chan_cfm(struct l2cap_chan *chan, u16 result)
4953 {
4954 struct l2cap_move_chan_cfm cfm;
4955
4956 BT_DBG("chan %p, result 0x%4.4x", chan, result);
4957
4958 chan->ident = l2cap_get_ident(chan->conn);
4959
4960 cfm.icid = cpu_to_le16(chan->scid);
4961 cfm.result = cpu_to_le16(result);
4962
4963 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_CFM,
4964 sizeof(cfm), &cfm);
4965
4966 __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
4967 }
4968
l2cap_send_move_chan_cfm_icid(struct l2cap_conn * conn,u16 icid)4969 static void l2cap_send_move_chan_cfm_icid(struct l2cap_conn *conn, u16 icid)
4970 {
4971 struct l2cap_move_chan_cfm cfm;
4972
4973 BT_DBG("conn %p, icid 0x%4.4x", conn, icid);
4974
4975 cfm.icid = cpu_to_le16(icid);
4976 cfm.result = cpu_to_le16(L2CAP_MC_UNCONFIRMED);
4977
4978 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_MOVE_CHAN_CFM,
4979 sizeof(cfm), &cfm);
4980 }
4981
l2cap_send_move_chan_cfm_rsp(struct l2cap_conn * conn,u8 ident,u16 icid)4982 static void l2cap_send_move_chan_cfm_rsp(struct l2cap_conn *conn, u8 ident,
4983 u16 icid)
4984 {
4985 struct l2cap_move_chan_cfm_rsp rsp;
4986
4987 BT_DBG("icid 0x%4.4x", icid);
4988
4989 rsp.icid = cpu_to_le16(icid);
4990 l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_CFM_RSP, sizeof(rsp), &rsp);
4991 }
4992
__release_logical_link(struct l2cap_chan * chan)4993 static void __release_logical_link(struct l2cap_chan *chan)
4994 {
4995 chan->hs_hchan = NULL;
4996 chan->hs_hcon = NULL;
4997
4998 /* Placeholder - release the logical link */
4999 }
5000
l2cap_logical_fail(struct l2cap_chan * chan)5001 static void l2cap_logical_fail(struct l2cap_chan *chan)
5002 {
5003 /* Logical link setup failed */
5004 if (chan->state != BT_CONNECTED) {
5005 /* Create channel failure, disconnect */
5006 l2cap_send_disconn_req(chan, ECONNRESET);
5007 return;
5008 }
5009
5010 switch (chan->move_role) {
5011 case L2CAP_MOVE_ROLE_RESPONDER:
5012 l2cap_move_done(chan);
5013 l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_SUPP);
5014 break;
5015 case L2CAP_MOVE_ROLE_INITIATOR:
5016 if (chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_COMP ||
5017 chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_CFM) {
5018 /* Remote has only sent pending or
5019 * success responses, clean up
5020 */
5021 l2cap_move_done(chan);
5022 }
5023
5024 /* Other amp move states imply that the move
5025 * has already aborted
5026 */
5027 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5028 break;
5029 }
5030 }
5031
l2cap_logical_finish_create(struct l2cap_chan * chan,struct hci_chan * hchan)5032 static void l2cap_logical_finish_create(struct l2cap_chan *chan,
5033 struct hci_chan *hchan)
5034 {
5035 struct l2cap_conf_rsp rsp;
5036
5037 chan->hs_hchan = hchan;
5038 chan->hs_hcon->l2cap_data = chan->conn;
5039
5040 l2cap_send_efs_conf_rsp(chan, &rsp, chan->ident, 0);
5041
5042 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
5043 int err;
5044
5045 set_default_fcs(chan);
5046
5047 err = l2cap_ertm_init(chan);
5048 if (err < 0)
5049 l2cap_send_disconn_req(chan, -err);
5050 else
5051 l2cap_chan_ready(chan);
5052 }
5053 }
5054
l2cap_logical_finish_move(struct l2cap_chan * chan,struct hci_chan * hchan)5055 static void l2cap_logical_finish_move(struct l2cap_chan *chan,
5056 struct hci_chan *hchan)
5057 {
5058 chan->hs_hcon = hchan->conn;
5059 chan->hs_hcon->l2cap_data = chan->conn;
5060
5061 BT_DBG("move_state %d", chan->move_state);
5062
5063 switch (chan->move_state) {
5064 case L2CAP_MOVE_WAIT_LOGICAL_COMP:
5065 /* Move confirm will be sent after a success
5066 * response is received
5067 */
5068 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
5069 break;
5070 case L2CAP_MOVE_WAIT_LOGICAL_CFM:
5071 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5072 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
5073 } else if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
5074 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
5075 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
5076 } else if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) {
5077 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
5078 l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS);
5079 }
5080 break;
5081 default:
5082 /* Move was not in expected state, free the channel */
5083 __release_logical_link(chan);
5084
5085 chan->move_state = L2CAP_MOVE_STABLE;
5086 }
5087 }
5088
5089 /* Call with chan locked */
l2cap_logical_cfm(struct l2cap_chan * chan,struct hci_chan * hchan,u8 status)5090 void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan,
5091 u8 status)
5092 {
5093 BT_DBG("chan %p, hchan %p, status %d", chan, hchan, status);
5094
5095 if (status) {
5096 l2cap_logical_fail(chan);
5097 __release_logical_link(chan);
5098 return;
5099 }
5100
5101 if (chan->state != BT_CONNECTED) {
5102 /* Ignore logical link if channel is on BR/EDR */
5103 if (chan->local_amp_id != AMP_ID_BREDR)
5104 l2cap_logical_finish_create(chan, hchan);
5105 } else {
5106 l2cap_logical_finish_move(chan, hchan);
5107 }
5108 }
5109
l2cap_move_start(struct l2cap_chan * chan)5110 void l2cap_move_start(struct l2cap_chan *chan)
5111 {
5112 BT_DBG("chan %p", chan);
5113
5114 if (chan->local_amp_id == AMP_ID_BREDR) {
5115 if (chan->chan_policy != BT_CHANNEL_POLICY_AMP_PREFERRED)
5116 return;
5117 chan->move_role = L2CAP_MOVE_ROLE_INITIATOR;
5118 chan->move_state = L2CAP_MOVE_WAIT_PREPARE;
5119 /* Placeholder - start physical link setup */
5120 } else {
5121 chan->move_role = L2CAP_MOVE_ROLE_INITIATOR;
5122 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
5123 chan->move_id = 0;
5124 l2cap_move_setup(chan);
5125 l2cap_send_move_chan_req(chan, 0);
5126 }
5127 }
5128
l2cap_do_create(struct l2cap_chan * chan,int result,u8 local_amp_id,u8 remote_amp_id)5129 static void l2cap_do_create(struct l2cap_chan *chan, int result,
5130 u8 local_amp_id, u8 remote_amp_id)
5131 {
5132 BT_DBG("chan %p state %s %u -> %u", chan, state_to_string(chan->state),
5133 local_amp_id, remote_amp_id);
5134
5135 chan->fcs = L2CAP_FCS_NONE;
5136
5137 /* Outgoing channel on AMP */
5138 if (chan->state == BT_CONNECT) {
5139 if (result == L2CAP_CR_SUCCESS) {
5140 chan->local_amp_id = local_amp_id;
5141 l2cap_send_create_chan_req(chan, remote_amp_id);
5142 } else {
5143 /* Revert to BR/EDR connect */
5144 l2cap_send_conn_req(chan);
5145 }
5146
5147 return;
5148 }
5149
5150 /* Incoming channel on AMP */
5151 if (__l2cap_no_conn_pending(chan)) {
5152 struct l2cap_conn_rsp rsp;
5153 char buf[128];
5154 rsp.scid = cpu_to_le16(chan->dcid);
5155 rsp.dcid = cpu_to_le16(chan->scid);
5156
5157 if (result == L2CAP_CR_SUCCESS) {
5158 /* Send successful response */
5159 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
5160 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
5161 } else {
5162 /* Send negative response */
5163 rsp.result = cpu_to_le16(L2CAP_CR_NO_MEM);
5164 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
5165 }
5166
5167 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_RSP,
5168 sizeof(rsp), &rsp);
5169
5170 if (result == L2CAP_CR_SUCCESS) {
5171 l2cap_state_change(chan, BT_CONFIG);
5172 set_bit(CONF_REQ_SENT, &chan->conf_state);
5173 l2cap_send_cmd(chan->conn, l2cap_get_ident(chan->conn),
5174 L2CAP_CONF_REQ,
5175 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
5176 chan->num_conf_req++;
5177 }
5178 }
5179 }
5180
l2cap_do_move_initiate(struct l2cap_chan * chan,u8 local_amp_id,u8 remote_amp_id)5181 static void l2cap_do_move_initiate(struct l2cap_chan *chan, u8 local_amp_id,
5182 u8 remote_amp_id)
5183 {
5184 l2cap_move_setup(chan);
5185 chan->move_id = local_amp_id;
5186 chan->move_state = L2CAP_MOVE_WAIT_RSP;
5187
5188 l2cap_send_move_chan_req(chan, remote_amp_id);
5189 }
5190
l2cap_do_move_respond(struct l2cap_chan * chan,int result)5191 static void l2cap_do_move_respond(struct l2cap_chan *chan, int result)
5192 {
5193 struct hci_chan *hchan = NULL;
5194
5195 /* Placeholder - get hci_chan for logical link */
5196
5197 if (hchan) {
5198 if (hchan->state == BT_CONNECTED) {
5199 /* Logical link is ready to go */
5200 chan->hs_hcon = hchan->conn;
5201 chan->hs_hcon->l2cap_data = chan->conn;
5202 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
5203 l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS);
5204
5205 l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
5206 } else {
5207 /* Wait for logical link to be ready */
5208 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
5209 }
5210 } else {
5211 /* Logical link not available */
5212 l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_ALLOWED);
5213 }
5214 }
5215
l2cap_do_move_cancel(struct l2cap_chan * chan,int result)5216 static void l2cap_do_move_cancel(struct l2cap_chan *chan, int result)
5217 {
5218 if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) {
5219 u8 rsp_result;
5220 if (result == -EINVAL)
5221 rsp_result = L2CAP_MR_BAD_ID;
5222 else
5223 rsp_result = L2CAP_MR_NOT_ALLOWED;
5224
5225 l2cap_send_move_chan_rsp(chan, rsp_result);
5226 }
5227
5228 chan->move_role = L2CAP_MOVE_ROLE_NONE;
5229 chan->move_state = L2CAP_MOVE_STABLE;
5230
5231 /* Restart data transmission */
5232 l2cap_ertm_send(chan);
5233 }
5234
5235 /* Invoke with locked chan */
__l2cap_physical_cfm(struct l2cap_chan * chan,int result)5236 void __l2cap_physical_cfm(struct l2cap_chan *chan, int result)
5237 {
5238 u8 local_amp_id = chan->local_amp_id;
5239 u8 remote_amp_id = chan->remote_amp_id;
5240
5241 BT_DBG("chan %p, result %d, local_amp_id %d, remote_amp_id %d",
5242 chan, result, local_amp_id, remote_amp_id);
5243
5244 if (chan->state == BT_DISCONN || chan->state == BT_CLOSED)
5245 return;
5246
5247 if (chan->state != BT_CONNECTED) {
5248 l2cap_do_create(chan, result, local_amp_id, remote_amp_id);
5249 } else if (result != L2CAP_MR_SUCCESS) {
5250 l2cap_do_move_cancel(chan, result);
5251 } else {
5252 switch (chan->move_role) {
5253 case L2CAP_MOVE_ROLE_INITIATOR:
5254 l2cap_do_move_initiate(chan, local_amp_id,
5255 remote_amp_id);
5256 break;
5257 case L2CAP_MOVE_ROLE_RESPONDER:
5258 l2cap_do_move_respond(chan, result);
5259 break;
5260 default:
5261 l2cap_do_move_cancel(chan, result);
5262 break;
5263 }
5264 }
5265 }
5266
l2cap_move_channel_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,void * data)5267 static inline int l2cap_move_channel_req(struct l2cap_conn *conn,
5268 struct l2cap_cmd_hdr *cmd,
5269 u16 cmd_len, void *data)
5270 {
5271 struct l2cap_move_chan_req *req = data;
5272 struct l2cap_move_chan_rsp rsp;
5273 struct l2cap_chan *chan;
5274 u16 icid = 0;
5275 u16 result = L2CAP_MR_NOT_ALLOWED;
5276
5277 if (cmd_len != sizeof(*req))
5278 return -EPROTO;
5279
5280 icid = le16_to_cpu(req->icid);
5281
5282 BT_DBG("icid 0x%4.4x, dest_amp_id %d", icid, req->dest_amp_id);
5283
5284 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
5285 return -EINVAL;
5286
5287 chan = l2cap_get_chan_by_dcid(conn, icid);
5288 if (!chan) {
5289 rsp.icid = cpu_to_le16(icid);
5290 rsp.result = cpu_to_le16(L2CAP_MR_NOT_ALLOWED);
5291 l2cap_send_cmd(conn, cmd->ident, L2CAP_MOVE_CHAN_RSP,
5292 sizeof(rsp), &rsp);
5293 return 0;
5294 }
5295
5296 chan->ident = cmd->ident;
5297
5298 if (chan->scid < L2CAP_CID_DYN_START ||
5299 chan->chan_policy == BT_CHANNEL_POLICY_BREDR_ONLY ||
5300 (chan->mode != L2CAP_MODE_ERTM &&
5301 chan->mode != L2CAP_MODE_STREAMING)) {
5302 result = L2CAP_MR_NOT_ALLOWED;
5303 goto send_move_response;
5304 }
5305
5306 if (chan->local_amp_id == req->dest_amp_id) {
5307 result = L2CAP_MR_SAME_ID;
5308 goto send_move_response;
5309 }
5310
5311 if (req->dest_amp_id != AMP_ID_BREDR) {
5312 struct hci_dev *hdev;
5313 hdev = hci_dev_get(req->dest_amp_id);
5314 if (!hdev || hdev->dev_type != HCI_AMP ||
5315 !test_bit(HCI_UP, &hdev->flags)) {
5316 if (hdev)
5317 hci_dev_put(hdev);
5318
5319 result = L2CAP_MR_BAD_ID;
5320 goto send_move_response;
5321 }
5322 hci_dev_put(hdev);
5323 }
5324
5325 /* Detect a move collision. Only send a collision response
5326 * if this side has "lost", otherwise proceed with the move.
5327 * The winner has the larger bd_addr.
5328 */
5329 if ((__chan_is_moving(chan) ||
5330 chan->move_role != L2CAP_MOVE_ROLE_NONE) &&
5331 bacmp(&conn->hcon->src, &conn->hcon->dst) > 0) {
5332 result = L2CAP_MR_COLLISION;
5333 goto send_move_response;
5334 }
5335
5336 chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
5337 l2cap_move_setup(chan);
5338 chan->move_id = req->dest_amp_id;
5339
5340 if (req->dest_amp_id == AMP_ID_BREDR) {
5341 /* Moving to BR/EDR */
5342 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5343 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
5344 result = L2CAP_MR_PEND;
5345 } else {
5346 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
5347 result = L2CAP_MR_SUCCESS;
5348 }
5349 } else {
5350 chan->move_state = L2CAP_MOVE_WAIT_PREPARE;
5351 /* Placeholder - uncomment when amp functions are available */
5352 /*amp_accept_physical(chan, req->dest_amp_id);*/
5353 result = L2CAP_MR_PEND;
5354 }
5355
5356 send_move_response:
5357 l2cap_send_move_chan_rsp(chan, result);
5358
5359 l2cap_chan_unlock(chan);
5360 l2cap_chan_put(chan);
5361
5362 return 0;
5363 }
5364
l2cap_move_continue(struct l2cap_conn * conn,u16 icid,u16 result)5365 static void l2cap_move_continue(struct l2cap_conn *conn, u16 icid, u16 result)
5366 {
5367 struct l2cap_chan *chan;
5368 struct hci_chan *hchan = NULL;
5369
5370 chan = l2cap_get_chan_by_scid(conn, icid);
5371 if (!chan) {
5372 l2cap_send_move_chan_cfm_icid(conn, icid);
5373 return;
5374 }
5375
5376 __clear_chan_timer(chan);
5377 if (result == L2CAP_MR_PEND)
5378 __set_chan_timer(chan, L2CAP_MOVE_ERTX_TIMEOUT);
5379
5380 switch (chan->move_state) {
5381 case L2CAP_MOVE_WAIT_LOGICAL_COMP:
5382 /* Move confirm will be sent when logical link
5383 * is complete.
5384 */
5385 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
5386 break;
5387 case L2CAP_MOVE_WAIT_RSP_SUCCESS:
5388 if (result == L2CAP_MR_PEND) {
5389 break;
5390 } else if (test_bit(CONN_LOCAL_BUSY,
5391 &chan->conn_state)) {
5392 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
5393 } else {
5394 /* Logical link is up or moving to BR/EDR,
5395 * proceed with move
5396 */
5397 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
5398 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
5399 }
5400 break;
5401 case L2CAP_MOVE_WAIT_RSP:
5402 /* Moving to AMP */
5403 if (result == L2CAP_MR_SUCCESS) {
5404 /* Remote is ready, send confirm immediately
5405 * after logical link is ready
5406 */
5407 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
5408 } else {
5409 /* Both logical link and move success
5410 * are required to confirm
5411 */
5412 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_COMP;
5413 }
5414
5415 /* Placeholder - get hci_chan for logical link */
5416 if (!hchan) {
5417 /* Logical link not available */
5418 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5419 break;
5420 }
5421
5422 /* If the logical link is not yet connected, do not
5423 * send confirmation.
5424 */
5425 if (hchan->state != BT_CONNECTED)
5426 break;
5427
5428 /* Logical link is already ready to go */
5429
5430 chan->hs_hcon = hchan->conn;
5431 chan->hs_hcon->l2cap_data = chan->conn;
5432
5433 if (result == L2CAP_MR_SUCCESS) {
5434 /* Can confirm now */
5435 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
5436 } else {
5437 /* Now only need move success
5438 * to confirm
5439 */
5440 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
5441 }
5442
5443 l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
5444 break;
5445 default:
5446 /* Any other amp move state means the move failed. */
5447 chan->move_id = chan->local_amp_id;
5448 l2cap_move_done(chan);
5449 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5450 }
5451
5452 l2cap_chan_unlock(chan);
5453 l2cap_chan_put(chan);
5454 }
5455
l2cap_move_fail(struct l2cap_conn * conn,u8 ident,u16 icid,u16 result)5456 static void l2cap_move_fail(struct l2cap_conn *conn, u8 ident, u16 icid,
5457 u16 result)
5458 {
5459 struct l2cap_chan *chan;
5460
5461 chan = l2cap_get_chan_by_ident(conn, ident);
5462 if (!chan) {
5463 /* Could not locate channel, icid is best guess */
5464 l2cap_send_move_chan_cfm_icid(conn, icid);
5465 return;
5466 }
5467
5468 __clear_chan_timer(chan);
5469
5470 if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
5471 if (result == L2CAP_MR_COLLISION) {
5472 chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
5473 } else {
5474 /* Cleanup - cancel move */
5475 chan->move_id = chan->local_amp_id;
5476 l2cap_move_done(chan);
5477 }
5478 }
5479
5480 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5481
5482 l2cap_chan_unlock(chan);
5483 l2cap_chan_put(chan);
5484 }
5485
l2cap_move_channel_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,void * data)5486 static int l2cap_move_channel_rsp(struct l2cap_conn *conn,
5487 struct l2cap_cmd_hdr *cmd,
5488 u16 cmd_len, void *data)
5489 {
5490 struct l2cap_move_chan_rsp *rsp = data;
5491 u16 icid, result;
5492
5493 if (cmd_len != sizeof(*rsp))
5494 return -EPROTO;
5495
5496 icid = le16_to_cpu(rsp->icid);
5497 result = le16_to_cpu(rsp->result);
5498
5499 BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
5500
5501 if (result == L2CAP_MR_SUCCESS || result == L2CAP_MR_PEND)
5502 l2cap_move_continue(conn, icid, result);
5503 else
5504 l2cap_move_fail(conn, cmd->ident, icid, result);
5505
5506 return 0;
5507 }
5508
l2cap_move_channel_confirm(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,void * data)5509 static int l2cap_move_channel_confirm(struct l2cap_conn *conn,
5510 struct l2cap_cmd_hdr *cmd,
5511 u16 cmd_len, void *data)
5512 {
5513 struct l2cap_move_chan_cfm *cfm = data;
5514 struct l2cap_chan *chan;
5515 u16 icid, result;
5516
5517 if (cmd_len != sizeof(*cfm))
5518 return -EPROTO;
5519
5520 icid = le16_to_cpu(cfm->icid);
5521 result = le16_to_cpu(cfm->result);
5522
5523 BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
5524
5525 chan = l2cap_get_chan_by_dcid(conn, icid);
5526 if (!chan) {
5527 /* Spec requires a response even if the icid was not found */
5528 l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
5529 return 0;
5530 }
5531
5532 if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM) {
5533 if (result == L2CAP_MC_CONFIRMED) {
5534 chan->local_amp_id = chan->move_id;
5535 if (chan->local_amp_id == AMP_ID_BREDR)
5536 __release_logical_link(chan);
5537 } else {
5538 chan->move_id = chan->local_amp_id;
5539 }
5540
5541 l2cap_move_done(chan);
5542 }
5543
5544 l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
5545
5546 l2cap_chan_unlock(chan);
5547 l2cap_chan_put(chan);
5548
5549 return 0;
5550 }
5551
l2cap_move_channel_confirm_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,void * data)5552 static inline int l2cap_move_channel_confirm_rsp(struct l2cap_conn *conn,
5553 struct l2cap_cmd_hdr *cmd,
5554 u16 cmd_len, void *data)
5555 {
5556 struct l2cap_move_chan_cfm_rsp *rsp = data;
5557 struct l2cap_chan *chan;
5558 u16 icid;
5559
5560 if (cmd_len != sizeof(*rsp))
5561 return -EPROTO;
5562
5563 icid = le16_to_cpu(rsp->icid);
5564
5565 BT_DBG("icid 0x%4.4x", icid);
5566
5567 chan = l2cap_get_chan_by_scid(conn, icid);
5568 if (!chan)
5569 return 0;
5570
5571 __clear_chan_timer(chan);
5572
5573 if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM_RSP) {
5574 chan->local_amp_id = chan->move_id;
5575
5576 if (chan->local_amp_id == AMP_ID_BREDR && chan->hs_hchan)
5577 __release_logical_link(chan);
5578
5579 l2cap_move_done(chan);
5580 }
5581
5582 l2cap_chan_unlock(chan);
5583 l2cap_chan_put(chan);
5584
5585 return 0;
5586 }
5587
l2cap_conn_param_update_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5588 static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
5589 struct l2cap_cmd_hdr *cmd,
5590 u16 cmd_len, u8 *data)
5591 {
5592 struct hci_conn *hcon = conn->hcon;
5593 struct l2cap_conn_param_update_req *req;
5594 struct l2cap_conn_param_update_rsp rsp;
5595 u16 min, max, latency, to_multiplier;
5596 int err;
5597
5598 if (hcon->role != HCI_ROLE_MASTER)
5599 return -EINVAL;
5600
5601 if (cmd_len != sizeof(struct l2cap_conn_param_update_req))
5602 return -EPROTO;
5603
5604 req = (struct l2cap_conn_param_update_req *) data;
5605 min = __le16_to_cpu(req->min);
5606 max = __le16_to_cpu(req->max);
5607 latency = __le16_to_cpu(req->latency);
5608 to_multiplier = __le16_to_cpu(req->to_multiplier);
5609
5610 BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x",
5611 min, max, latency, to_multiplier);
5612
5613 memset(&rsp, 0, sizeof(rsp));
5614
5615 err = hci_check_conn_params(min, max, latency, to_multiplier);
5616 if (err)
5617 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
5618 else
5619 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED);
5620
5621 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP,
5622 sizeof(rsp), &rsp);
5623
5624 if (!err) {
5625 u8 store_hint;
5626
5627 store_hint = hci_le_conn_update(hcon, min, max, latency,
5628 to_multiplier);
5629 mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type,
5630 store_hint, min, max, latency,
5631 to_multiplier);
5632
5633 }
5634
5635 return 0;
5636 }
5637
l2cap_le_connect_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5638 static int l2cap_le_connect_rsp(struct l2cap_conn *conn,
5639 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5640 u8 *data)
5641 {
5642 struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data;
5643 struct hci_conn *hcon = conn->hcon;
5644 u16 dcid, mtu, mps, credits, result;
5645 struct l2cap_chan *chan;
5646 int err, sec_level;
5647
5648 if (cmd_len < sizeof(*rsp))
5649 return -EPROTO;
5650
5651 dcid = __le16_to_cpu(rsp->dcid);
5652 mtu = __le16_to_cpu(rsp->mtu);
5653 mps = __le16_to_cpu(rsp->mps);
5654 credits = __le16_to_cpu(rsp->credits);
5655 result = __le16_to_cpu(rsp->result);
5656
5657 if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 ||
5658 dcid < L2CAP_CID_DYN_START ||
5659 dcid > L2CAP_CID_LE_DYN_END))
5660 return -EPROTO;
5661
5662 BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x",
5663 dcid, mtu, mps, credits, result);
5664
5665 mutex_lock(&conn->chan_lock);
5666
5667 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
5668 if (!chan) {
5669 err = -EBADSLT;
5670 goto unlock;
5671 }
5672
5673 err = 0;
5674
5675 l2cap_chan_lock(chan);
5676
5677 switch (result) {
5678 case L2CAP_CR_LE_SUCCESS:
5679 if (__l2cap_get_chan_by_dcid(conn, dcid)) {
5680 err = -EBADSLT;
5681 break;
5682 }
5683
5684 chan->ident = 0;
5685 chan->dcid = dcid;
5686 chan->omtu = mtu;
5687 chan->remote_mps = mps;
5688 chan->tx_credits = credits;
5689 l2cap_chan_ready(chan);
5690 break;
5691
5692 case L2CAP_CR_LE_AUTHENTICATION:
5693 case L2CAP_CR_LE_ENCRYPTION:
5694 /* If we already have MITM protection we can't do
5695 * anything.
5696 */
5697 if (hcon->sec_level > BT_SECURITY_MEDIUM) {
5698 l2cap_chan_del(chan, ECONNREFUSED);
5699 break;
5700 }
5701
5702 sec_level = hcon->sec_level + 1;
5703 if (chan->sec_level < sec_level)
5704 chan->sec_level = sec_level;
5705
5706 /* We'll need to send a new Connect Request */
5707 clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags);
5708
5709 smp_conn_security(hcon, chan->sec_level);
5710 break;
5711
5712 default:
5713 l2cap_chan_del(chan, ECONNREFUSED);
5714 break;
5715 }
5716
5717 l2cap_chan_unlock(chan);
5718
5719 unlock:
5720 mutex_unlock(&conn->chan_lock);
5721
5722 return err;
5723 }
5724
l2cap_bredr_sig_cmd(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5725 static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
5726 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5727 u8 *data)
5728 {
5729 int err = 0;
5730
5731 switch (cmd->code) {
5732 case L2CAP_COMMAND_REJ:
5733 l2cap_command_rej(conn, cmd, cmd_len, data);
5734 break;
5735
5736 case L2CAP_CONN_REQ:
5737 err = l2cap_connect_req(conn, cmd, cmd_len, data);
5738 break;
5739
5740 case L2CAP_CONN_RSP:
5741 case L2CAP_CREATE_CHAN_RSP:
5742 l2cap_connect_create_rsp(conn, cmd, cmd_len, data);
5743 break;
5744
5745 case L2CAP_CONF_REQ:
5746 err = l2cap_config_req(conn, cmd, cmd_len, data);
5747 break;
5748
5749 case L2CAP_CONF_RSP:
5750 l2cap_config_rsp(conn, cmd, cmd_len, data);
5751 break;
5752
5753 case L2CAP_DISCONN_REQ:
5754 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
5755 break;
5756
5757 case L2CAP_DISCONN_RSP:
5758 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
5759 break;
5760
5761 case L2CAP_ECHO_REQ:
5762 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data);
5763 break;
5764
5765 case L2CAP_ECHO_RSP:
5766 break;
5767
5768 case L2CAP_INFO_REQ:
5769 err = l2cap_information_req(conn, cmd, cmd_len, data);
5770 break;
5771
5772 case L2CAP_INFO_RSP:
5773 l2cap_information_rsp(conn, cmd, cmd_len, data);
5774 break;
5775
5776 case L2CAP_CREATE_CHAN_REQ:
5777 err = l2cap_create_channel_req(conn, cmd, cmd_len, data);
5778 break;
5779
5780 case L2CAP_MOVE_CHAN_REQ:
5781 err = l2cap_move_channel_req(conn, cmd, cmd_len, data);
5782 break;
5783
5784 case L2CAP_MOVE_CHAN_RSP:
5785 l2cap_move_channel_rsp(conn, cmd, cmd_len, data);
5786 break;
5787
5788 case L2CAP_MOVE_CHAN_CFM:
5789 err = l2cap_move_channel_confirm(conn, cmd, cmd_len, data);
5790 break;
5791
5792 case L2CAP_MOVE_CHAN_CFM_RSP:
5793 l2cap_move_channel_confirm_rsp(conn, cmd, cmd_len, data);
5794 break;
5795
5796 default:
5797 BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code);
5798 err = -EINVAL;
5799 break;
5800 }
5801
5802 return err;
5803 }
5804
l2cap_le_connect_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5805 static int l2cap_le_connect_req(struct l2cap_conn *conn,
5806 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5807 u8 *data)
5808 {
5809 struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data;
5810 struct l2cap_le_conn_rsp rsp;
5811 struct l2cap_chan *chan, *pchan;
5812 u16 dcid, scid, credits, mtu, mps;
5813 __le16 psm;
5814 u8 result;
5815
5816 if (cmd_len != sizeof(*req))
5817 return -EPROTO;
5818
5819 scid = __le16_to_cpu(req->scid);
5820 mtu = __le16_to_cpu(req->mtu);
5821 mps = __le16_to_cpu(req->mps);
5822 psm = req->psm;
5823 dcid = 0;
5824 credits = 0;
5825
5826 if (mtu < 23 || mps < 23)
5827 return -EPROTO;
5828
5829 BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
5830 scid, mtu, mps);
5831
5832 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
5833 * page 1059:
5834 *
5835 * Valid range: 0x0001-0x00ff
5836 *
5837 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
5838 */
5839 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
5840 result = L2CAP_CR_LE_BAD_PSM;
5841 chan = NULL;
5842 goto response;
5843 }
5844
5845 /* Check if we have socket listening on psm */
5846 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
5847 &conn->hcon->dst, LE_LINK);
5848 if (!pchan) {
5849 result = L2CAP_CR_LE_BAD_PSM;
5850 chan = NULL;
5851 goto response;
5852 }
5853
5854 mutex_lock(&conn->chan_lock);
5855 l2cap_chan_lock(pchan);
5856
5857 if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
5858 SMP_ALLOW_STK)) {
5859 result = L2CAP_CR_LE_AUTHENTICATION;
5860 chan = NULL;
5861 goto response_unlock;
5862 }
5863
5864 /* Check for valid dynamic CID range */
5865 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
5866 result = L2CAP_CR_LE_INVALID_SCID;
5867 chan = NULL;
5868 goto response_unlock;
5869 }
5870
5871 /* Check if we already have channel with that dcid */
5872 if (__l2cap_get_chan_by_dcid(conn, scid)) {
5873 result = L2CAP_CR_LE_SCID_IN_USE;
5874 chan = NULL;
5875 goto response_unlock;
5876 }
5877
5878 chan = pchan->ops->new_connection(pchan);
5879 if (!chan) {
5880 result = L2CAP_CR_LE_NO_MEM;
5881 goto response_unlock;
5882 }
5883
5884 bacpy(&chan->src, &conn->hcon->src);
5885 bacpy(&chan->dst, &conn->hcon->dst);
5886 chan->src_type = bdaddr_src_type(conn->hcon);
5887 chan->dst_type = bdaddr_dst_type(conn->hcon);
5888 chan->psm = psm;
5889 chan->dcid = scid;
5890 chan->omtu = mtu;
5891 chan->remote_mps = mps;
5892
5893 __l2cap_chan_add(conn, chan);
5894
5895 l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits));
5896
5897 dcid = chan->scid;
5898 credits = chan->rx_credits;
5899
5900 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
5901
5902 chan->ident = cmd->ident;
5903
5904 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
5905 l2cap_state_change(chan, BT_CONNECT2);
5906 /* The following result value is actually not defined
5907 * for LE CoC but we use it to let the function know
5908 * that it should bail out after doing its cleanup
5909 * instead of sending a response.
5910 */
5911 result = L2CAP_CR_PEND;
5912 chan->ops->defer(chan);
5913 } else {
5914 l2cap_chan_ready(chan);
5915 result = L2CAP_CR_LE_SUCCESS;
5916 }
5917
5918 response_unlock:
5919 l2cap_chan_unlock(pchan);
5920 mutex_unlock(&conn->chan_lock);
5921 l2cap_chan_put(pchan);
5922
5923 if (result == L2CAP_CR_PEND)
5924 return 0;
5925
5926 response:
5927 if (chan) {
5928 rsp.mtu = cpu_to_le16(chan->imtu);
5929 rsp.mps = cpu_to_le16(chan->mps);
5930 } else {
5931 rsp.mtu = 0;
5932 rsp.mps = 0;
5933 }
5934
5935 rsp.dcid = cpu_to_le16(dcid);
5936 rsp.credits = cpu_to_le16(credits);
5937 rsp.result = cpu_to_le16(result);
5938
5939 l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp);
5940
5941 return 0;
5942 }
5943
l2cap_le_credits(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5944 static inline int l2cap_le_credits(struct l2cap_conn *conn,
5945 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5946 u8 *data)
5947 {
5948 struct l2cap_le_credits *pkt;
5949 struct l2cap_chan *chan;
5950 u16 cid, credits, max_credits;
5951
5952 if (cmd_len != sizeof(*pkt))
5953 return -EPROTO;
5954
5955 pkt = (struct l2cap_le_credits *) data;
5956 cid = __le16_to_cpu(pkt->cid);
5957 credits = __le16_to_cpu(pkt->credits);
5958
5959 BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits);
5960
5961 chan = l2cap_get_chan_by_dcid(conn, cid);
5962 if (!chan)
5963 return -EBADSLT;
5964
5965 max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits;
5966 if (credits > max_credits) {
5967 BT_ERR("LE credits overflow");
5968 l2cap_send_disconn_req(chan, ECONNRESET);
5969
5970 /* Return 0 so that we don't trigger an unnecessary
5971 * command reject packet.
5972 */
5973 goto unlock;
5974 }
5975
5976 chan->tx_credits += credits;
5977
5978 /* Resume sending */
5979 l2cap_le_flowctl_send(chan);
5980
5981 if (chan->tx_credits)
5982 chan->ops->resume(chan);
5983
5984 unlock:
5985 l2cap_chan_unlock(chan);
5986 l2cap_chan_put(chan);
5987
5988 return 0;
5989 }
5990
l2cap_ecred_conn_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5991 static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
5992 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5993 u8 *data)
5994 {
5995 struct l2cap_ecred_conn_req *req = (void *) data;
5996 struct {
5997 struct l2cap_ecred_conn_rsp rsp;
5998 __le16 dcid[L2CAP_ECRED_MAX_CID];
5999 } __packed pdu;
6000 struct l2cap_chan *chan, *pchan;
6001 u16 mtu, mps;
6002 __le16 psm;
6003 u8 result, len = 0;
6004 int i, num_scid;
6005 bool defer = false;
6006
6007 if (!enable_ecred)
6008 return -EINVAL;
6009
6010 if (cmd_len < sizeof(*req) || (cmd_len - sizeof(*req)) % sizeof(u16)) {
6011 result = L2CAP_CR_LE_INVALID_PARAMS;
6012 goto response;
6013 }
6014
6015 cmd_len -= sizeof(*req);
6016 num_scid = cmd_len / sizeof(u16);
6017
6018 if (num_scid > ARRAY_SIZE(pdu.dcid)) {
6019 result = L2CAP_CR_LE_INVALID_PARAMS;
6020 goto response;
6021 }
6022
6023 mtu = __le16_to_cpu(req->mtu);
6024 mps = __le16_to_cpu(req->mps);
6025
6026 if (mtu < L2CAP_ECRED_MIN_MTU || mps < L2CAP_ECRED_MIN_MPS) {
6027 result = L2CAP_CR_LE_UNACCEPT_PARAMS;
6028 goto response;
6029 }
6030
6031 psm = req->psm;
6032
6033 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
6034 * page 1059:
6035 *
6036 * Valid range: 0x0001-0x00ff
6037 *
6038 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
6039 */
6040 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
6041 result = L2CAP_CR_LE_BAD_PSM;
6042 goto response;
6043 }
6044
6045 BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps);
6046
6047 memset(&pdu, 0, sizeof(pdu));
6048
6049 /* Check if we have socket listening on psm */
6050 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
6051 &conn->hcon->dst, LE_LINK);
6052 if (!pchan) {
6053 result = L2CAP_CR_LE_BAD_PSM;
6054 goto response;
6055 }
6056
6057 mutex_lock(&conn->chan_lock);
6058 l2cap_chan_lock(pchan);
6059
6060 if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
6061 SMP_ALLOW_STK)) {
6062 result = L2CAP_CR_LE_AUTHENTICATION;
6063 goto unlock;
6064 }
6065
6066 result = L2CAP_CR_LE_SUCCESS;
6067
6068 for (i = 0; i < num_scid; i++) {
6069 u16 scid = __le16_to_cpu(req->scid[i]);
6070
6071 BT_DBG("scid[%d] 0x%4.4x", i, scid);
6072
6073 pdu.dcid[i] = 0x0000;
6074 len += sizeof(*pdu.dcid);
6075
6076 /* Check for valid dynamic CID range */
6077 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
6078 result = L2CAP_CR_LE_INVALID_SCID;
6079 continue;
6080 }
6081
6082 /* Check if we already have channel with that dcid */
6083 if (__l2cap_get_chan_by_dcid(conn, scid)) {
6084 result = L2CAP_CR_LE_SCID_IN_USE;
6085 continue;
6086 }
6087
6088 chan = pchan->ops->new_connection(pchan);
6089 if (!chan) {
6090 result = L2CAP_CR_LE_NO_MEM;
6091 continue;
6092 }
6093
6094 bacpy(&chan->src, &conn->hcon->src);
6095 bacpy(&chan->dst, &conn->hcon->dst);
6096 chan->src_type = bdaddr_src_type(conn->hcon);
6097 chan->dst_type = bdaddr_dst_type(conn->hcon);
6098 chan->psm = psm;
6099 chan->dcid = scid;
6100 chan->omtu = mtu;
6101 chan->remote_mps = mps;
6102
6103 __l2cap_chan_add(conn, chan);
6104
6105 l2cap_ecred_init(chan, __le16_to_cpu(req->credits));
6106
6107 /* Init response */
6108 if (!pdu.rsp.credits) {
6109 pdu.rsp.mtu = cpu_to_le16(chan->imtu);
6110 pdu.rsp.mps = cpu_to_le16(chan->mps);
6111 pdu.rsp.credits = cpu_to_le16(chan->rx_credits);
6112 }
6113
6114 pdu.dcid[i] = cpu_to_le16(chan->scid);
6115
6116 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
6117
6118 chan->ident = cmd->ident;
6119 chan->mode = L2CAP_MODE_EXT_FLOWCTL;
6120
6121 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
6122 l2cap_state_change(chan, BT_CONNECT2);
6123 defer = true;
6124 chan->ops->defer(chan);
6125 } else {
6126 l2cap_chan_ready(chan);
6127 }
6128 }
6129
6130 unlock:
6131 l2cap_chan_unlock(pchan);
6132 mutex_unlock(&conn->chan_lock);
6133 l2cap_chan_put(pchan);
6134
6135 response:
6136 pdu.rsp.result = cpu_to_le16(result);
6137
6138 if (defer)
6139 return 0;
6140
6141 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_CONN_RSP,
6142 sizeof(pdu.rsp) + len, &pdu);
6143
6144 return 0;
6145 }
6146
l2cap_ecred_conn_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)6147 static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn,
6148 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
6149 u8 *data)
6150 {
6151 struct l2cap_ecred_conn_rsp *rsp = (void *) data;
6152 struct hci_conn *hcon = conn->hcon;
6153 u16 mtu, mps, credits, result;
6154 struct l2cap_chan *chan, *tmp;
6155 int err = 0, sec_level;
6156 int i = 0;
6157
6158 if (cmd_len < sizeof(*rsp))
6159 return -EPROTO;
6160
6161 mtu = __le16_to_cpu(rsp->mtu);
6162 mps = __le16_to_cpu(rsp->mps);
6163 credits = __le16_to_cpu(rsp->credits);
6164 result = __le16_to_cpu(rsp->result);
6165
6166 BT_DBG("mtu %u mps %u credits %u result 0x%4.4x", mtu, mps, credits,
6167 result);
6168
6169 mutex_lock(&conn->chan_lock);
6170
6171 cmd_len -= sizeof(*rsp);
6172
6173 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
6174 u16 dcid;
6175
6176 if (chan->ident != cmd->ident ||
6177 chan->mode != L2CAP_MODE_EXT_FLOWCTL ||
6178 chan->state == BT_CONNECTED)
6179 continue;
6180
6181 l2cap_chan_lock(chan);
6182
6183 /* Check that there is a dcid for each pending channel */
6184 if (cmd_len < sizeof(dcid)) {
6185 l2cap_chan_del(chan, ECONNREFUSED);
6186 l2cap_chan_unlock(chan);
6187 continue;
6188 }
6189
6190 dcid = __le16_to_cpu(rsp->dcid[i++]);
6191 cmd_len -= sizeof(u16);
6192
6193 BT_DBG("dcid[%d] 0x%4.4x", i, dcid);
6194
6195 /* Check if dcid is already in use */
6196 if (dcid && __l2cap_get_chan_by_dcid(conn, dcid)) {
6197 /* If a device receives a
6198 * L2CAP_CREDIT_BASED_CONNECTION_RSP packet with an
6199 * already-assigned Destination CID, then both the
6200 * original channel and the new channel shall be
6201 * immediately discarded and not used.
6202 */
6203 l2cap_chan_del(chan, ECONNREFUSED);
6204 l2cap_chan_unlock(chan);
6205 chan = __l2cap_get_chan_by_dcid(conn, dcid);
6206 l2cap_chan_lock(chan);
6207 l2cap_chan_del(chan, ECONNRESET);
6208 l2cap_chan_unlock(chan);
6209 continue;
6210 }
6211
6212 switch (result) {
6213 case L2CAP_CR_LE_AUTHENTICATION:
6214 case L2CAP_CR_LE_ENCRYPTION:
6215 /* If we already have MITM protection we can't do
6216 * anything.
6217 */
6218 if (hcon->sec_level > BT_SECURITY_MEDIUM) {
6219 l2cap_chan_del(chan, ECONNREFUSED);
6220 break;
6221 }
6222
6223 sec_level = hcon->sec_level + 1;
6224 if (chan->sec_level < sec_level)
6225 chan->sec_level = sec_level;
6226
6227 /* We'll need to send a new Connect Request */
6228 clear_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags);
6229
6230 smp_conn_security(hcon, chan->sec_level);
6231 break;
6232
6233 case L2CAP_CR_LE_BAD_PSM:
6234 l2cap_chan_del(chan, ECONNREFUSED);
6235 break;
6236
6237 default:
6238 /* If dcid was not set it means channels was refused */
6239 if (!dcid) {
6240 l2cap_chan_del(chan, ECONNREFUSED);
6241 break;
6242 }
6243
6244 chan->ident = 0;
6245 chan->dcid = dcid;
6246 chan->omtu = mtu;
6247 chan->remote_mps = mps;
6248 chan->tx_credits = credits;
6249 l2cap_chan_ready(chan);
6250 break;
6251 }
6252
6253 l2cap_chan_unlock(chan);
6254 }
6255
6256 mutex_unlock(&conn->chan_lock);
6257
6258 return err;
6259 }
6260
l2cap_ecred_reconf_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)6261 static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn,
6262 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
6263 u8 *data)
6264 {
6265 struct l2cap_ecred_reconf_req *req = (void *) data;
6266 struct l2cap_ecred_reconf_rsp rsp;
6267 u16 mtu, mps, result;
6268 struct l2cap_chan *chan;
6269 int i, num_scid;
6270
6271 if (!enable_ecred)
6272 return -EINVAL;
6273
6274 if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) {
6275 result = L2CAP_CR_LE_INVALID_PARAMS;
6276 goto respond;
6277 }
6278
6279 mtu = __le16_to_cpu(req->mtu);
6280 mps = __le16_to_cpu(req->mps);
6281
6282 BT_DBG("mtu %u mps %u", mtu, mps);
6283
6284 if (mtu < L2CAP_ECRED_MIN_MTU) {
6285 result = L2CAP_RECONF_INVALID_MTU;
6286 goto respond;
6287 }
6288
6289 if (mps < L2CAP_ECRED_MIN_MPS) {
6290 result = L2CAP_RECONF_INVALID_MPS;
6291 goto respond;
6292 }
6293
6294 cmd_len -= sizeof(*req);
6295 num_scid = cmd_len / sizeof(u16);
6296 result = L2CAP_RECONF_SUCCESS;
6297
6298 for (i = 0; i < num_scid; i++) {
6299 u16 scid;
6300
6301 scid = __le16_to_cpu(req->scid[i]);
6302 if (!scid)
6303 return -EPROTO;
6304
6305 chan = __l2cap_get_chan_by_dcid(conn, scid);
6306 if (!chan)
6307 continue;
6308
6309 /* If the MTU value is decreased for any of the included
6310 * channels, then the receiver shall disconnect all
6311 * included channels.
6312 */
6313 if (chan->omtu > mtu) {
6314 BT_ERR("chan %p decreased MTU %u -> %u", chan,
6315 chan->omtu, mtu);
6316 result = L2CAP_RECONF_INVALID_MTU;
6317 }
6318
6319 chan->omtu = mtu;
6320 chan->remote_mps = mps;
6321 }
6322
6323 respond:
6324 rsp.result = cpu_to_le16(result);
6325
6326 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_RECONF_RSP, sizeof(rsp),
6327 &rsp);
6328
6329 return 0;
6330 }
6331
l2cap_ecred_reconf_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)6332 static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn,
6333 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
6334 u8 *data)
6335 {
6336 struct l2cap_chan *chan, *tmp;
6337 struct l2cap_ecred_conn_rsp *rsp = (void *) data;
6338 u16 result;
6339
6340 if (cmd_len < sizeof(*rsp))
6341 return -EPROTO;
6342
6343 result = __le16_to_cpu(rsp->result);
6344
6345 BT_DBG("result 0x%4.4x", rsp->result);
6346
6347 if (!result)
6348 return 0;
6349
6350 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
6351 if (chan->ident != cmd->ident)
6352 continue;
6353
6354 l2cap_chan_del(chan, ECONNRESET);
6355 }
6356
6357 return 0;
6358 }
6359
l2cap_le_command_rej(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)6360 static inline int l2cap_le_command_rej(struct l2cap_conn *conn,
6361 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
6362 u8 *data)
6363 {
6364 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
6365 struct l2cap_chan *chan;
6366
6367 if (cmd_len < sizeof(*rej))
6368 return -EPROTO;
6369
6370 mutex_lock(&conn->chan_lock);
6371
6372 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
6373 if (!chan)
6374 goto done;
6375
6376 chan = l2cap_chan_hold_unless_zero(chan);
6377 if (!chan)
6378 goto done;
6379
6380 l2cap_chan_lock(chan);
6381 l2cap_chan_del(chan, ECONNREFUSED);
6382 l2cap_chan_unlock(chan);
6383 l2cap_chan_put(chan);
6384
6385 done:
6386 mutex_unlock(&conn->chan_lock);
6387 return 0;
6388 }
6389
l2cap_le_sig_cmd(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)6390 static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
6391 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
6392 u8 *data)
6393 {
6394 int err = 0;
6395
6396 switch (cmd->code) {
6397 case L2CAP_COMMAND_REJ:
6398 l2cap_le_command_rej(conn, cmd, cmd_len, data);
6399 break;
6400
6401 case L2CAP_CONN_PARAM_UPDATE_REQ:
6402 err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data);
6403 break;
6404
6405 case L2CAP_CONN_PARAM_UPDATE_RSP:
6406 break;
6407
6408 case L2CAP_LE_CONN_RSP:
6409 l2cap_le_connect_rsp(conn, cmd, cmd_len, data);
6410 break;
6411
6412 case L2CAP_LE_CONN_REQ:
6413 err = l2cap_le_connect_req(conn, cmd, cmd_len, data);
6414 break;
6415
6416 case L2CAP_LE_CREDITS:
6417 err = l2cap_le_credits(conn, cmd, cmd_len, data);
6418 break;
6419
6420 case L2CAP_ECRED_CONN_REQ:
6421 err = l2cap_ecred_conn_req(conn, cmd, cmd_len, data);
6422 break;
6423
6424 case L2CAP_ECRED_CONN_RSP:
6425 err = l2cap_ecred_conn_rsp(conn, cmd, cmd_len, data);
6426 break;
6427
6428 case L2CAP_ECRED_RECONF_REQ:
6429 err = l2cap_ecred_reconf_req(conn, cmd, cmd_len, data);
6430 break;
6431
6432 case L2CAP_ECRED_RECONF_RSP:
6433 err = l2cap_ecred_reconf_rsp(conn, cmd, cmd_len, data);
6434 break;
6435
6436 case L2CAP_DISCONN_REQ:
6437 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
6438 break;
6439
6440 case L2CAP_DISCONN_RSP:
6441 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
6442 break;
6443
6444 default:
6445 BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code);
6446 err = -EINVAL;
6447 break;
6448 }
6449
6450 return err;
6451 }
6452
l2cap_le_sig_channel(struct l2cap_conn * conn,struct sk_buff * skb)6453 static inline void l2cap_le_sig_channel(struct l2cap_conn *conn,
6454 struct sk_buff *skb)
6455 {
6456 struct hci_conn *hcon = conn->hcon;
6457 struct l2cap_cmd_hdr *cmd;
6458 u16 len;
6459 int err;
6460
6461 if (hcon->type != LE_LINK)
6462 goto drop;
6463
6464 if (skb->len < L2CAP_CMD_HDR_SIZE)
6465 goto drop;
6466
6467 cmd = (void *) skb->data;
6468 skb_pull(skb, L2CAP_CMD_HDR_SIZE);
6469
6470 len = le16_to_cpu(cmd->len);
6471
6472 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident);
6473
6474 if (len != skb->len || !cmd->ident) {
6475 BT_DBG("corrupted command");
6476 goto drop;
6477 }
6478
6479 err = l2cap_le_sig_cmd(conn, cmd, len, skb->data);
6480 if (err) {
6481 struct l2cap_cmd_rej_unk rej;
6482
6483 BT_ERR("Wrong link type (%d)", err);
6484
6485 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
6486 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ,
6487 sizeof(rej), &rej);
6488 }
6489
6490 drop:
6491 kfree_skb(skb);
6492 }
6493
l2cap_sig_send_rej(struct l2cap_conn * conn,u16 ident)6494 static inline void l2cap_sig_send_rej(struct l2cap_conn *conn, u16 ident)
6495 {
6496 struct l2cap_cmd_rej_unk rej;
6497
6498 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
6499 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
6500 }
6501
l2cap_sig_channel(struct l2cap_conn * conn,struct sk_buff * skb)6502 static inline void l2cap_sig_channel(struct l2cap_conn *conn,
6503 struct sk_buff *skb)
6504 {
6505 struct hci_conn *hcon = conn->hcon;
6506 struct l2cap_cmd_hdr *cmd;
6507 int err;
6508
6509 l2cap_raw_recv(conn, skb);
6510
6511 if (hcon->type != ACL_LINK)
6512 goto drop;
6513
6514 while (skb->len >= L2CAP_CMD_HDR_SIZE) {
6515 u16 len;
6516
6517 cmd = (void *) skb->data;
6518 skb_pull(skb, L2CAP_CMD_HDR_SIZE);
6519
6520 len = le16_to_cpu(cmd->len);
6521
6522 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len,
6523 cmd->ident);
6524
6525 if (len > skb->len || !cmd->ident) {
6526 BT_DBG("corrupted command");
6527 l2cap_sig_send_rej(conn, cmd->ident);
6528 break;
6529 }
6530
6531 err = l2cap_bredr_sig_cmd(conn, cmd, len, skb->data);
6532 if (err) {
6533 BT_ERR("Wrong link type (%d)", err);
6534 l2cap_sig_send_rej(conn, cmd->ident);
6535 }
6536
6537 skb_pull(skb, len);
6538 }
6539
6540 if (skb->len > 0) {
6541 BT_DBG("corrupted command");
6542 l2cap_sig_send_rej(conn, 0);
6543 }
6544
6545 drop:
6546 kfree_skb(skb);
6547 }
6548
l2cap_check_fcs(struct l2cap_chan * chan,struct sk_buff * skb)6549 static int l2cap_check_fcs(struct l2cap_chan *chan, struct sk_buff *skb)
6550 {
6551 u16 our_fcs, rcv_fcs;
6552 int hdr_size;
6553
6554 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
6555 hdr_size = L2CAP_EXT_HDR_SIZE;
6556 else
6557 hdr_size = L2CAP_ENH_HDR_SIZE;
6558
6559 if (chan->fcs == L2CAP_FCS_CRC16) {
6560 skb_trim(skb, skb->len - L2CAP_FCS_SIZE);
6561 rcv_fcs = get_unaligned_le16(skb->data + skb->len);
6562 our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size);
6563
6564 if (our_fcs != rcv_fcs)
6565 return -EBADMSG;
6566 }
6567 return 0;
6568 }
6569
l2cap_send_i_or_rr_or_rnr(struct l2cap_chan * chan)6570 static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan)
6571 {
6572 struct l2cap_ctrl control;
6573
6574 BT_DBG("chan %p", chan);
6575
6576 memset(&control, 0, sizeof(control));
6577 control.sframe = 1;
6578 control.final = 1;
6579 control.reqseq = chan->buffer_seq;
6580 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6581
6582 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6583 control.super = L2CAP_SUPER_RNR;
6584 l2cap_send_sframe(chan, &control);
6585 }
6586
6587 if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) &&
6588 chan->unacked_frames > 0)
6589 __set_retrans_timer(chan);
6590
6591 /* Send pending iframes */
6592 l2cap_ertm_send(chan);
6593
6594 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
6595 test_bit(CONN_SEND_FBIT, &chan->conn_state)) {
6596 /* F-bit wasn't sent in an s-frame or i-frame yet, so
6597 * send it now.
6598 */
6599 control.super = L2CAP_SUPER_RR;
6600 l2cap_send_sframe(chan, &control);
6601 }
6602 }
6603
append_skb_frag(struct sk_buff * skb,struct sk_buff * new_frag,struct sk_buff ** last_frag)6604 static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag,
6605 struct sk_buff **last_frag)
6606 {
6607 /* skb->len reflects data in skb as well as all fragments
6608 * skb->data_len reflects only data in fragments
6609 */
6610 if (!skb_has_frag_list(skb))
6611 skb_shinfo(skb)->frag_list = new_frag;
6612
6613 new_frag->next = NULL;
6614
6615 (*last_frag)->next = new_frag;
6616 *last_frag = new_frag;
6617
6618 skb->len += new_frag->len;
6619 skb->data_len += new_frag->len;
6620 skb->truesize += new_frag->truesize;
6621 }
6622
l2cap_reassemble_sdu(struct l2cap_chan * chan,struct sk_buff * skb,struct l2cap_ctrl * control)6623 static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb,
6624 struct l2cap_ctrl *control)
6625 {
6626 int err = -EINVAL;
6627
6628 switch (control->sar) {
6629 case L2CAP_SAR_UNSEGMENTED:
6630 if (chan->sdu)
6631 break;
6632
6633 err = chan->ops->recv(chan, skb);
6634 break;
6635
6636 case L2CAP_SAR_START:
6637 if (chan->sdu)
6638 break;
6639
6640 if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE))
6641 break;
6642
6643 chan->sdu_len = get_unaligned_le16(skb->data);
6644 skb_pull(skb, L2CAP_SDULEN_SIZE);
6645
6646 if (chan->sdu_len > chan->imtu) {
6647 err = -EMSGSIZE;
6648 break;
6649 }
6650
6651 if (skb->len >= chan->sdu_len)
6652 break;
6653
6654 chan->sdu = skb;
6655 chan->sdu_last_frag = skb;
6656
6657 skb = NULL;
6658 err = 0;
6659 break;
6660
6661 case L2CAP_SAR_CONTINUE:
6662 if (!chan->sdu)
6663 break;
6664
6665 append_skb_frag(chan->sdu, skb,
6666 &chan->sdu_last_frag);
6667 skb = NULL;
6668
6669 if (chan->sdu->len >= chan->sdu_len)
6670 break;
6671
6672 err = 0;
6673 break;
6674
6675 case L2CAP_SAR_END:
6676 if (!chan->sdu)
6677 break;
6678
6679 append_skb_frag(chan->sdu, skb,
6680 &chan->sdu_last_frag);
6681 skb = NULL;
6682
6683 if (chan->sdu->len != chan->sdu_len)
6684 break;
6685
6686 err = chan->ops->recv(chan, chan->sdu);
6687
6688 if (!err) {
6689 /* Reassembly complete */
6690 chan->sdu = NULL;
6691 chan->sdu_last_frag = NULL;
6692 chan->sdu_len = 0;
6693 }
6694 break;
6695 }
6696
6697 if (err) {
6698 kfree_skb(skb);
6699 kfree_skb(chan->sdu);
6700 chan->sdu = NULL;
6701 chan->sdu_last_frag = NULL;
6702 chan->sdu_len = 0;
6703 }
6704
6705 return err;
6706 }
6707
l2cap_resegment(struct l2cap_chan * chan)6708 static int l2cap_resegment(struct l2cap_chan *chan)
6709 {
6710 /* Placeholder */
6711 return 0;
6712 }
6713
l2cap_chan_busy(struct l2cap_chan * chan,int busy)6714 void l2cap_chan_busy(struct l2cap_chan *chan, int busy)
6715 {
6716 u8 event;
6717
6718 if (chan->mode != L2CAP_MODE_ERTM)
6719 return;
6720
6721 event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR;
6722 l2cap_tx(chan, NULL, NULL, event);
6723 }
6724
l2cap_rx_queued_iframes(struct l2cap_chan * chan)6725 static int l2cap_rx_queued_iframes(struct l2cap_chan *chan)
6726 {
6727 int err = 0;
6728 /* Pass sequential frames to l2cap_reassemble_sdu()
6729 * until a gap is encountered.
6730 */
6731
6732 BT_DBG("chan %p", chan);
6733
6734 while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6735 struct sk_buff *skb;
6736 BT_DBG("Searching for skb with txseq %d (queue len %d)",
6737 chan->buffer_seq, skb_queue_len(&chan->srej_q));
6738
6739 skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq);
6740
6741 if (!skb)
6742 break;
6743
6744 skb_unlink(skb, &chan->srej_q);
6745 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
6746 err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap);
6747 if (err)
6748 break;
6749 }
6750
6751 if (skb_queue_empty(&chan->srej_q)) {
6752 chan->rx_state = L2CAP_RX_STATE_RECV;
6753 l2cap_send_ack(chan);
6754 }
6755
6756 return err;
6757 }
6758
l2cap_handle_srej(struct l2cap_chan * chan,struct l2cap_ctrl * control)6759 static void l2cap_handle_srej(struct l2cap_chan *chan,
6760 struct l2cap_ctrl *control)
6761 {
6762 struct sk_buff *skb;
6763
6764 BT_DBG("chan %p, control %p", chan, control);
6765
6766 if (control->reqseq == chan->next_tx_seq) {
6767 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
6768 l2cap_send_disconn_req(chan, ECONNRESET);
6769 return;
6770 }
6771
6772 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
6773
6774 if (skb == NULL) {
6775 BT_DBG("Seq %d not available for retransmission",
6776 control->reqseq);
6777 return;
6778 }
6779
6780 if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) {
6781 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
6782 l2cap_send_disconn_req(chan, ECONNRESET);
6783 return;
6784 }
6785
6786 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6787
6788 if (control->poll) {
6789 l2cap_pass_to_tx(chan, control);
6790
6791 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6792 l2cap_retransmit(chan, control);
6793 l2cap_ertm_send(chan);
6794
6795 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
6796 set_bit(CONN_SREJ_ACT, &chan->conn_state);
6797 chan->srej_save_reqseq = control->reqseq;
6798 }
6799 } else {
6800 l2cap_pass_to_tx_fbit(chan, control);
6801
6802 if (control->final) {
6803 if (chan->srej_save_reqseq != control->reqseq ||
6804 !test_and_clear_bit(CONN_SREJ_ACT,
6805 &chan->conn_state))
6806 l2cap_retransmit(chan, control);
6807 } else {
6808 l2cap_retransmit(chan, control);
6809 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
6810 set_bit(CONN_SREJ_ACT, &chan->conn_state);
6811 chan->srej_save_reqseq = control->reqseq;
6812 }
6813 }
6814 }
6815 }
6816
l2cap_handle_rej(struct l2cap_chan * chan,struct l2cap_ctrl * control)6817 static void l2cap_handle_rej(struct l2cap_chan *chan,
6818 struct l2cap_ctrl *control)
6819 {
6820 struct sk_buff *skb;
6821
6822 BT_DBG("chan %p, control %p", chan, control);
6823
6824 if (control->reqseq == chan->next_tx_seq) {
6825 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
6826 l2cap_send_disconn_req(chan, ECONNRESET);
6827 return;
6828 }
6829
6830 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
6831
6832 if (chan->max_tx && skb &&
6833 bt_cb(skb)->l2cap.retries >= chan->max_tx) {
6834 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
6835 l2cap_send_disconn_req(chan, ECONNRESET);
6836 return;
6837 }
6838
6839 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6840
6841 l2cap_pass_to_tx(chan, control);
6842
6843 if (control->final) {
6844 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state))
6845 l2cap_retransmit_all(chan, control);
6846 } else {
6847 l2cap_retransmit_all(chan, control);
6848 l2cap_ertm_send(chan);
6849 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F)
6850 set_bit(CONN_REJ_ACT, &chan->conn_state);
6851 }
6852 }
6853
l2cap_classify_txseq(struct l2cap_chan * chan,u16 txseq)6854 static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq)
6855 {
6856 BT_DBG("chan %p, txseq %d", chan, txseq);
6857
6858 BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq,
6859 chan->expected_tx_seq);
6860
6861 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
6862 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
6863 chan->tx_win) {
6864 /* See notes below regarding "double poll" and
6865 * invalid packets.
6866 */
6867 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
6868 BT_DBG("Invalid/Ignore - after SREJ");
6869 return L2CAP_TXSEQ_INVALID_IGNORE;
6870 } else {
6871 BT_DBG("Invalid - in window after SREJ sent");
6872 return L2CAP_TXSEQ_INVALID;
6873 }
6874 }
6875
6876 if (chan->srej_list.head == txseq) {
6877 BT_DBG("Expected SREJ");
6878 return L2CAP_TXSEQ_EXPECTED_SREJ;
6879 }
6880
6881 if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) {
6882 BT_DBG("Duplicate SREJ - txseq already stored");
6883 return L2CAP_TXSEQ_DUPLICATE_SREJ;
6884 }
6885
6886 if (l2cap_seq_list_contains(&chan->srej_list, txseq)) {
6887 BT_DBG("Unexpected SREJ - not requested");
6888 return L2CAP_TXSEQ_UNEXPECTED_SREJ;
6889 }
6890 }
6891
6892 if (chan->expected_tx_seq == txseq) {
6893 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
6894 chan->tx_win) {
6895 BT_DBG("Invalid - txseq outside tx window");
6896 return L2CAP_TXSEQ_INVALID;
6897 } else {
6898 BT_DBG("Expected");
6899 return L2CAP_TXSEQ_EXPECTED;
6900 }
6901 }
6902
6903 if (__seq_offset(chan, txseq, chan->last_acked_seq) <
6904 __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) {
6905 BT_DBG("Duplicate - expected_tx_seq later than txseq");
6906 return L2CAP_TXSEQ_DUPLICATE;
6907 }
6908
6909 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) {
6910 /* A source of invalid packets is a "double poll" condition,
6911 * where delays cause us to send multiple poll packets. If
6912 * the remote stack receives and processes both polls,
6913 * sequence numbers can wrap around in such a way that a
6914 * resent frame has a sequence number that looks like new data
6915 * with a sequence gap. This would trigger an erroneous SREJ
6916 * request.
6917 *
6918 * Fortunately, this is impossible with a tx window that's
6919 * less than half of the maximum sequence number, which allows
6920 * invalid frames to be safely ignored.
6921 *
6922 * With tx window sizes greater than half of the tx window
6923 * maximum, the frame is invalid and cannot be ignored. This
6924 * causes a disconnect.
6925 */
6926
6927 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
6928 BT_DBG("Invalid/Ignore - txseq outside tx window");
6929 return L2CAP_TXSEQ_INVALID_IGNORE;
6930 } else {
6931 BT_DBG("Invalid - txseq outside tx window");
6932 return L2CAP_TXSEQ_INVALID;
6933 }
6934 } else {
6935 BT_DBG("Unexpected - txseq indicates missing frames");
6936 return L2CAP_TXSEQ_UNEXPECTED;
6937 }
6938 }
6939
l2cap_rx_state_recv(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)6940 static int l2cap_rx_state_recv(struct l2cap_chan *chan,
6941 struct l2cap_ctrl *control,
6942 struct sk_buff *skb, u8 event)
6943 {
6944 struct l2cap_ctrl local_control;
6945 int err = 0;
6946 bool skb_in_use = false;
6947
6948 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6949 event);
6950
6951 switch (event) {
6952 case L2CAP_EV_RECV_IFRAME:
6953 switch (l2cap_classify_txseq(chan, control->txseq)) {
6954 case L2CAP_TXSEQ_EXPECTED:
6955 l2cap_pass_to_tx(chan, control);
6956
6957 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6958 BT_DBG("Busy, discarding expected seq %d",
6959 control->txseq);
6960 break;
6961 }
6962
6963 chan->expected_tx_seq = __next_seq(chan,
6964 control->txseq);
6965
6966 chan->buffer_seq = chan->expected_tx_seq;
6967 skb_in_use = true;
6968
6969 /* l2cap_reassemble_sdu may free skb, hence invalidate
6970 * control, so make a copy in advance to use it after
6971 * l2cap_reassemble_sdu returns and to avoid the race
6972 * condition, for example:
6973 *
6974 * The current thread calls:
6975 * l2cap_reassemble_sdu
6976 * chan->ops->recv == l2cap_sock_recv_cb
6977 * __sock_queue_rcv_skb
6978 * Another thread calls:
6979 * bt_sock_recvmsg
6980 * skb_recv_datagram
6981 * skb_free_datagram
6982 * Then the current thread tries to access control, but
6983 * it was freed by skb_free_datagram.
6984 */
6985 local_control = *control;
6986 err = l2cap_reassemble_sdu(chan, skb, control);
6987 if (err)
6988 break;
6989
6990 if (local_control.final) {
6991 if (!test_and_clear_bit(CONN_REJ_ACT,
6992 &chan->conn_state)) {
6993 local_control.final = 0;
6994 l2cap_retransmit_all(chan, &local_control);
6995 l2cap_ertm_send(chan);
6996 }
6997 }
6998
6999 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
7000 l2cap_send_ack(chan);
7001 break;
7002 case L2CAP_TXSEQ_UNEXPECTED:
7003 l2cap_pass_to_tx(chan, control);
7004
7005 /* Can't issue SREJ frames in the local busy state.
7006 * Drop this frame, it will be seen as missing
7007 * when local busy is exited.
7008 */
7009 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
7010 BT_DBG("Busy, discarding unexpected seq %d",
7011 control->txseq);
7012 break;
7013 }
7014
7015 /* There was a gap in the sequence, so an SREJ
7016 * must be sent for each missing frame. The
7017 * current frame is stored for later use.
7018 */
7019 skb_queue_tail(&chan->srej_q, skb);
7020 skb_in_use = true;
7021 BT_DBG("Queued %p (queue len %d)", skb,
7022 skb_queue_len(&chan->srej_q));
7023
7024 clear_bit(CONN_SREJ_ACT, &chan->conn_state);
7025 l2cap_seq_list_clear(&chan->srej_list);
7026 l2cap_send_srej(chan, control->txseq);
7027
7028 chan->rx_state = L2CAP_RX_STATE_SREJ_SENT;
7029 break;
7030 case L2CAP_TXSEQ_DUPLICATE:
7031 l2cap_pass_to_tx(chan, control);
7032 break;
7033 case L2CAP_TXSEQ_INVALID_IGNORE:
7034 break;
7035 case L2CAP_TXSEQ_INVALID:
7036 default:
7037 l2cap_send_disconn_req(chan, ECONNRESET);
7038 break;
7039 }
7040 break;
7041 case L2CAP_EV_RECV_RR:
7042 l2cap_pass_to_tx(chan, control);
7043 if (control->final) {
7044 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
7045
7046 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state) &&
7047 !__chan_is_moving(chan)) {
7048 control->final = 0;
7049 l2cap_retransmit_all(chan, control);
7050 }
7051
7052 l2cap_ertm_send(chan);
7053 } else if (control->poll) {
7054 l2cap_send_i_or_rr_or_rnr(chan);
7055 } else {
7056 if (test_and_clear_bit(CONN_REMOTE_BUSY,
7057 &chan->conn_state) &&
7058 chan->unacked_frames)
7059 __set_retrans_timer(chan);
7060
7061 l2cap_ertm_send(chan);
7062 }
7063 break;
7064 case L2CAP_EV_RECV_RNR:
7065 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
7066 l2cap_pass_to_tx(chan, control);
7067 if (control && control->poll) {
7068 set_bit(CONN_SEND_FBIT, &chan->conn_state);
7069 l2cap_send_rr_or_rnr(chan, 0);
7070 }
7071 __clear_retrans_timer(chan);
7072 l2cap_seq_list_clear(&chan->retrans_list);
7073 break;
7074 case L2CAP_EV_RECV_REJ:
7075 l2cap_handle_rej(chan, control);
7076 break;
7077 case L2CAP_EV_RECV_SREJ:
7078 l2cap_handle_srej(chan, control);
7079 break;
7080 default:
7081 break;
7082 }
7083
7084 if (skb && !skb_in_use) {
7085 BT_DBG("Freeing %p", skb);
7086 kfree_skb(skb);
7087 }
7088
7089 return err;
7090 }
7091
l2cap_rx_state_srej_sent(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)7092 static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan,
7093 struct l2cap_ctrl *control,
7094 struct sk_buff *skb, u8 event)
7095 {
7096 int err = 0;
7097 u16 txseq = control->txseq;
7098 bool skb_in_use = false;
7099
7100 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
7101 event);
7102
7103 switch (event) {
7104 case L2CAP_EV_RECV_IFRAME:
7105 switch (l2cap_classify_txseq(chan, txseq)) {
7106 case L2CAP_TXSEQ_EXPECTED:
7107 /* Keep frame for reassembly later */
7108 l2cap_pass_to_tx(chan, control);
7109 skb_queue_tail(&chan->srej_q, skb);
7110 skb_in_use = true;
7111 BT_DBG("Queued %p (queue len %d)", skb,
7112 skb_queue_len(&chan->srej_q));
7113
7114 chan->expected_tx_seq = __next_seq(chan, txseq);
7115 break;
7116 case L2CAP_TXSEQ_EXPECTED_SREJ:
7117 l2cap_seq_list_pop(&chan->srej_list);
7118
7119 l2cap_pass_to_tx(chan, control);
7120 skb_queue_tail(&chan->srej_q, skb);
7121 skb_in_use = true;
7122 BT_DBG("Queued %p (queue len %d)", skb,
7123 skb_queue_len(&chan->srej_q));
7124
7125 err = l2cap_rx_queued_iframes(chan);
7126 if (err)
7127 break;
7128
7129 break;
7130 case L2CAP_TXSEQ_UNEXPECTED:
7131 /* Got a frame that can't be reassembled yet.
7132 * Save it for later, and send SREJs to cover
7133 * the missing frames.
7134 */
7135 skb_queue_tail(&chan->srej_q, skb);
7136 skb_in_use = true;
7137 BT_DBG("Queued %p (queue len %d)", skb,
7138 skb_queue_len(&chan->srej_q));
7139
7140 l2cap_pass_to_tx(chan, control);
7141 l2cap_send_srej(chan, control->txseq);
7142 break;
7143 case L2CAP_TXSEQ_UNEXPECTED_SREJ:
7144 /* This frame was requested with an SREJ, but
7145 * some expected retransmitted frames are
7146 * missing. Request retransmission of missing
7147 * SREJ'd frames.
7148 */
7149 skb_queue_tail(&chan->srej_q, skb);
7150 skb_in_use = true;
7151 BT_DBG("Queued %p (queue len %d)", skb,
7152 skb_queue_len(&chan->srej_q));
7153
7154 l2cap_pass_to_tx(chan, control);
7155 l2cap_send_srej_list(chan, control->txseq);
7156 break;
7157 case L2CAP_TXSEQ_DUPLICATE_SREJ:
7158 /* We've already queued this frame. Drop this copy. */
7159 l2cap_pass_to_tx(chan, control);
7160 break;
7161 case L2CAP_TXSEQ_DUPLICATE:
7162 /* Expecting a later sequence number, so this frame
7163 * was already received. Ignore it completely.
7164 */
7165 break;
7166 case L2CAP_TXSEQ_INVALID_IGNORE:
7167 break;
7168 case L2CAP_TXSEQ_INVALID:
7169 default:
7170 l2cap_send_disconn_req(chan, ECONNRESET);
7171 break;
7172 }
7173 break;
7174 case L2CAP_EV_RECV_RR:
7175 l2cap_pass_to_tx(chan, control);
7176 if (control->final) {
7177 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
7178
7179 if (!test_and_clear_bit(CONN_REJ_ACT,
7180 &chan->conn_state)) {
7181 control->final = 0;
7182 l2cap_retransmit_all(chan, control);
7183 }
7184
7185 l2cap_ertm_send(chan);
7186 } else if (control->poll) {
7187 if (test_and_clear_bit(CONN_REMOTE_BUSY,
7188 &chan->conn_state) &&
7189 chan->unacked_frames) {
7190 __set_retrans_timer(chan);
7191 }
7192
7193 set_bit(CONN_SEND_FBIT, &chan->conn_state);
7194 l2cap_send_srej_tail(chan);
7195 } else {
7196 if (test_and_clear_bit(CONN_REMOTE_BUSY,
7197 &chan->conn_state) &&
7198 chan->unacked_frames)
7199 __set_retrans_timer(chan);
7200
7201 l2cap_send_ack(chan);
7202 }
7203 break;
7204 case L2CAP_EV_RECV_RNR:
7205 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
7206 l2cap_pass_to_tx(chan, control);
7207 if (control->poll) {
7208 l2cap_send_srej_tail(chan);
7209 } else {
7210 struct l2cap_ctrl rr_control;
7211 memset(&rr_control, 0, sizeof(rr_control));
7212 rr_control.sframe = 1;
7213 rr_control.super = L2CAP_SUPER_RR;
7214 rr_control.reqseq = chan->buffer_seq;
7215 l2cap_send_sframe(chan, &rr_control);
7216 }
7217
7218 break;
7219 case L2CAP_EV_RECV_REJ:
7220 l2cap_handle_rej(chan, control);
7221 break;
7222 case L2CAP_EV_RECV_SREJ:
7223 l2cap_handle_srej(chan, control);
7224 break;
7225 }
7226
7227 if (skb && !skb_in_use) {
7228 BT_DBG("Freeing %p", skb);
7229 kfree_skb(skb);
7230 }
7231
7232 return err;
7233 }
7234
l2cap_finish_move(struct l2cap_chan * chan)7235 static int l2cap_finish_move(struct l2cap_chan *chan)
7236 {
7237 BT_DBG("chan %p", chan);
7238
7239 chan->rx_state = L2CAP_RX_STATE_RECV;
7240
7241 if (chan->hs_hcon)
7242 chan->conn->mtu = chan->hs_hcon->hdev->block_mtu;
7243 else
7244 chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
7245
7246 return l2cap_resegment(chan);
7247 }
7248
l2cap_rx_state_wait_p(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)7249 static int l2cap_rx_state_wait_p(struct l2cap_chan *chan,
7250 struct l2cap_ctrl *control,
7251 struct sk_buff *skb, u8 event)
7252 {
7253 int err;
7254
7255 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
7256 event);
7257
7258 if (!control->poll)
7259 return -EPROTO;
7260
7261 l2cap_process_reqseq(chan, control->reqseq);
7262
7263 if (!skb_queue_empty(&chan->tx_q))
7264 chan->tx_send_head = skb_peek(&chan->tx_q);
7265 else
7266 chan->tx_send_head = NULL;
7267
7268 /* Rewind next_tx_seq to the point expected
7269 * by the receiver.
7270 */
7271 chan->next_tx_seq = control->reqseq;
7272 chan->unacked_frames = 0;
7273
7274 err = l2cap_finish_move(chan);
7275 if (err)
7276 return err;
7277
7278 set_bit(CONN_SEND_FBIT, &chan->conn_state);
7279 l2cap_send_i_or_rr_or_rnr(chan);
7280
7281 if (event == L2CAP_EV_RECV_IFRAME)
7282 return -EPROTO;
7283
7284 return l2cap_rx_state_recv(chan, control, NULL, event);
7285 }
7286
l2cap_rx_state_wait_f(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)7287 static int l2cap_rx_state_wait_f(struct l2cap_chan *chan,
7288 struct l2cap_ctrl *control,
7289 struct sk_buff *skb, u8 event)
7290 {
7291 int err;
7292
7293 if (!control->final)
7294 return -EPROTO;
7295
7296 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
7297
7298 chan->rx_state = L2CAP_RX_STATE_RECV;
7299 l2cap_process_reqseq(chan, control->reqseq);
7300
7301 if (!skb_queue_empty(&chan->tx_q))
7302 chan->tx_send_head = skb_peek(&chan->tx_q);
7303 else
7304 chan->tx_send_head = NULL;
7305
7306 /* Rewind next_tx_seq to the point expected
7307 * by the receiver.
7308 */
7309 chan->next_tx_seq = control->reqseq;
7310 chan->unacked_frames = 0;
7311
7312 if (chan->hs_hcon)
7313 chan->conn->mtu = chan->hs_hcon->hdev->block_mtu;
7314 else
7315 chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
7316
7317 err = l2cap_resegment(chan);
7318
7319 if (!err)
7320 err = l2cap_rx_state_recv(chan, control, skb, event);
7321
7322 return err;
7323 }
7324
__valid_reqseq(struct l2cap_chan * chan,u16 reqseq)7325 static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq)
7326 {
7327 /* Make sure reqseq is for a packet that has been sent but not acked */
7328 u16 unacked;
7329
7330 unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq);
7331 return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked;
7332 }
7333
l2cap_rx(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)7334 static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
7335 struct sk_buff *skb, u8 event)
7336 {
7337 int err = 0;
7338
7339 BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan,
7340 control, skb, event, chan->rx_state);
7341
7342 if (__valid_reqseq(chan, control->reqseq)) {
7343 switch (chan->rx_state) {
7344 case L2CAP_RX_STATE_RECV:
7345 err = l2cap_rx_state_recv(chan, control, skb, event);
7346 break;
7347 case L2CAP_RX_STATE_SREJ_SENT:
7348 err = l2cap_rx_state_srej_sent(chan, control, skb,
7349 event);
7350 break;
7351 case L2CAP_RX_STATE_WAIT_P:
7352 err = l2cap_rx_state_wait_p(chan, control, skb, event);
7353 break;
7354 case L2CAP_RX_STATE_WAIT_F:
7355 err = l2cap_rx_state_wait_f(chan, control, skb, event);
7356 break;
7357 default:
7358 /* shut it down */
7359 break;
7360 }
7361 } else {
7362 BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d",
7363 control->reqseq, chan->next_tx_seq,
7364 chan->expected_ack_seq);
7365 l2cap_send_disconn_req(chan, ECONNRESET);
7366 }
7367
7368 return err;
7369 }
7370
l2cap_stream_rx(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb)7371 static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
7372 struct sk_buff *skb)
7373 {
7374 /* l2cap_reassemble_sdu may free skb, hence invalidate control, so store
7375 * the txseq field in advance to use it after l2cap_reassemble_sdu
7376 * returns and to avoid the race condition, for example:
7377 *
7378 * The current thread calls:
7379 * l2cap_reassemble_sdu
7380 * chan->ops->recv == l2cap_sock_recv_cb
7381 * __sock_queue_rcv_skb
7382 * Another thread calls:
7383 * bt_sock_recvmsg
7384 * skb_recv_datagram
7385 * skb_free_datagram
7386 * Then the current thread tries to access control, but it was freed by
7387 * skb_free_datagram.
7388 */
7389 u16 txseq = control->txseq;
7390
7391 BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb,
7392 chan->rx_state);
7393
7394 if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) {
7395 l2cap_pass_to_tx(chan, control);
7396
7397 BT_DBG("buffer_seq %d->%d", chan->buffer_seq,
7398 __next_seq(chan, chan->buffer_seq));
7399
7400 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
7401
7402 l2cap_reassemble_sdu(chan, skb, control);
7403 } else {
7404 if (chan->sdu) {
7405 kfree_skb(chan->sdu);
7406 chan->sdu = NULL;
7407 }
7408 chan->sdu_last_frag = NULL;
7409 chan->sdu_len = 0;
7410
7411 if (skb) {
7412 BT_DBG("Freeing %p", skb);
7413 kfree_skb(skb);
7414 }
7415 }
7416
7417 chan->last_acked_seq = txseq;
7418 chan->expected_tx_seq = __next_seq(chan, txseq);
7419
7420 return 0;
7421 }
7422
l2cap_data_rcv(struct l2cap_chan * chan,struct sk_buff * skb)7423 static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
7424 {
7425 struct l2cap_ctrl *control = &bt_cb(skb)->l2cap;
7426 u16 len;
7427 u8 event;
7428
7429 __unpack_control(chan, skb);
7430
7431 len = skb->len;
7432
7433 /*
7434 * We can just drop the corrupted I-frame here.
7435 * Receiver will miss it and start proper recovery
7436 * procedures and ask for retransmission.
7437 */
7438 if (l2cap_check_fcs(chan, skb))
7439 goto drop;
7440
7441 if (!control->sframe && control->sar == L2CAP_SAR_START)
7442 len -= L2CAP_SDULEN_SIZE;
7443
7444 if (chan->fcs == L2CAP_FCS_CRC16)
7445 len -= L2CAP_FCS_SIZE;
7446
7447 if (len > chan->mps) {
7448 l2cap_send_disconn_req(chan, ECONNRESET);
7449 goto drop;
7450 }
7451
7452 if (chan->ops->filter) {
7453 if (chan->ops->filter(chan, skb))
7454 goto drop;
7455 }
7456
7457 if (!control->sframe) {
7458 int err;
7459
7460 BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d",
7461 control->sar, control->reqseq, control->final,
7462 control->txseq);
7463
7464 /* Validate F-bit - F=0 always valid, F=1 only
7465 * valid in TX WAIT_F
7466 */
7467 if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F)
7468 goto drop;
7469
7470 if (chan->mode != L2CAP_MODE_STREAMING) {
7471 event = L2CAP_EV_RECV_IFRAME;
7472 err = l2cap_rx(chan, control, skb, event);
7473 } else {
7474 err = l2cap_stream_rx(chan, control, skb);
7475 }
7476
7477 if (err)
7478 l2cap_send_disconn_req(chan, ECONNRESET);
7479 } else {
7480 const u8 rx_func_to_event[4] = {
7481 L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ,
7482 L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ
7483 };
7484
7485 /* Only I-frames are expected in streaming mode */
7486 if (chan->mode == L2CAP_MODE_STREAMING)
7487 goto drop;
7488
7489 BT_DBG("sframe reqseq %d, final %d, poll %d, super %d",
7490 control->reqseq, control->final, control->poll,
7491 control->super);
7492
7493 if (len != 0) {
7494 BT_ERR("Trailing bytes: %d in sframe", len);
7495 l2cap_send_disconn_req(chan, ECONNRESET);
7496 goto drop;
7497 }
7498
7499 /* Validate F and P bits */
7500 if (control->final && (control->poll ||
7501 chan->tx_state != L2CAP_TX_STATE_WAIT_F))
7502 goto drop;
7503
7504 event = rx_func_to_event[control->super];
7505 if (l2cap_rx(chan, control, skb, event))
7506 l2cap_send_disconn_req(chan, ECONNRESET);
7507 }
7508
7509 return 0;
7510
7511 drop:
7512 kfree_skb(skb);
7513 return 0;
7514 }
7515
l2cap_chan_le_send_credits(struct l2cap_chan * chan)7516 static void l2cap_chan_le_send_credits(struct l2cap_chan *chan)
7517 {
7518 struct l2cap_conn *conn = chan->conn;
7519 struct l2cap_le_credits pkt;
7520 u16 return_credits;
7521
7522 return_credits = (chan->imtu / chan->mps) + 1;
7523
7524 if (chan->rx_credits >= return_credits)
7525 return;
7526
7527 return_credits -= chan->rx_credits;
7528
7529 BT_DBG("chan %p returning %u credits to sender", chan, return_credits);
7530
7531 chan->rx_credits += return_credits;
7532
7533 pkt.cid = cpu_to_le16(chan->scid);
7534 pkt.credits = cpu_to_le16(return_credits);
7535
7536 chan->ident = l2cap_get_ident(conn);
7537
7538 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt);
7539 }
7540
l2cap_ecred_recv(struct l2cap_chan * chan,struct sk_buff * skb)7541 static int l2cap_ecred_recv(struct l2cap_chan *chan, struct sk_buff *skb)
7542 {
7543 int err;
7544
7545 BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len);
7546
7547 /* Wait recv to confirm reception before updating the credits */
7548 err = chan->ops->recv(chan, skb);
7549
7550 /* Update credits whenever an SDU is received */
7551 l2cap_chan_le_send_credits(chan);
7552
7553 return err;
7554 }
7555
l2cap_ecred_data_rcv(struct l2cap_chan * chan,struct sk_buff * skb)7556 static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
7557 {
7558 int err;
7559
7560 if (!chan->rx_credits) {
7561 BT_ERR("No credits to receive LE L2CAP data");
7562 l2cap_send_disconn_req(chan, ECONNRESET);
7563 return -ENOBUFS;
7564 }
7565
7566 if (chan->imtu < skb->len) {
7567 BT_ERR("Too big LE L2CAP PDU");
7568 return -ENOBUFS;
7569 }
7570
7571 chan->rx_credits--;
7572 BT_DBG("rx_credits %u -> %u", chan->rx_credits + 1, chan->rx_credits);
7573
7574 /* Update if remote had run out of credits, this should only happens
7575 * if the remote is not using the entire MPS.
7576 */
7577 if (!chan->rx_credits)
7578 l2cap_chan_le_send_credits(chan);
7579
7580 err = 0;
7581
7582 if (!chan->sdu) {
7583 u16 sdu_len;
7584
7585 sdu_len = get_unaligned_le16(skb->data);
7586 skb_pull(skb, L2CAP_SDULEN_SIZE);
7587
7588 BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u",
7589 sdu_len, skb->len, chan->imtu);
7590
7591 if (sdu_len > chan->imtu) {
7592 BT_ERR("Too big LE L2CAP SDU length received");
7593 err = -EMSGSIZE;
7594 goto failed;
7595 }
7596
7597 if (skb->len > sdu_len) {
7598 BT_ERR("Too much LE L2CAP data received");
7599 err = -EINVAL;
7600 goto failed;
7601 }
7602
7603 if (skb->len == sdu_len)
7604 return l2cap_ecred_recv(chan, skb);
7605
7606 chan->sdu = skb;
7607 chan->sdu_len = sdu_len;
7608 chan->sdu_last_frag = skb;
7609
7610 /* Detect if remote is not able to use the selected MPS */
7611 if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) {
7612 u16 mps_len = skb->len + L2CAP_SDULEN_SIZE;
7613
7614 /* Adjust the number of credits */
7615 BT_DBG("chan->mps %u -> %u", chan->mps, mps_len);
7616 chan->mps = mps_len;
7617 l2cap_chan_le_send_credits(chan);
7618 }
7619
7620 return 0;
7621 }
7622
7623 BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u",
7624 chan->sdu->len, skb->len, chan->sdu_len);
7625
7626 if (chan->sdu->len + skb->len > chan->sdu_len) {
7627 BT_ERR("Too much LE L2CAP data received");
7628 err = -EINVAL;
7629 goto failed;
7630 }
7631
7632 append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag);
7633 skb = NULL;
7634
7635 if (chan->sdu->len == chan->sdu_len) {
7636 err = l2cap_ecred_recv(chan, chan->sdu);
7637 if (!err) {
7638 chan->sdu = NULL;
7639 chan->sdu_last_frag = NULL;
7640 chan->sdu_len = 0;
7641 }
7642 }
7643
7644 failed:
7645 if (err) {
7646 kfree_skb(skb);
7647 kfree_skb(chan->sdu);
7648 chan->sdu = NULL;
7649 chan->sdu_last_frag = NULL;
7650 chan->sdu_len = 0;
7651 }
7652
7653 /* We can't return an error here since we took care of the skb
7654 * freeing internally. An error return would cause the caller to
7655 * do a double-free of the skb.
7656 */
7657 return 0;
7658 }
7659
l2cap_data_channel(struct l2cap_conn * conn,u16 cid,struct sk_buff * skb)7660 static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,
7661 struct sk_buff *skb)
7662 {
7663 struct l2cap_chan *chan;
7664
7665 chan = l2cap_get_chan_by_scid(conn, cid);
7666 if (!chan) {
7667 if (cid == L2CAP_CID_A2MP) {
7668 chan = a2mp_channel_create(conn, skb);
7669 if (!chan) {
7670 kfree_skb(skb);
7671 return;
7672 }
7673
7674 l2cap_chan_hold(chan);
7675 l2cap_chan_lock(chan);
7676 } else {
7677 BT_DBG("unknown cid 0x%4.4x", cid);
7678 /* Drop packet and return */
7679 kfree_skb(skb);
7680 return;
7681 }
7682 }
7683
7684 BT_DBG("chan %p, len %d", chan, skb->len);
7685
7686 /* If we receive data on a fixed channel before the info req/rsp
7687 * procedure is done simply assume that the channel is supported
7688 * and mark it as ready.
7689 */
7690 if (chan->chan_type == L2CAP_CHAN_FIXED)
7691 l2cap_chan_ready(chan);
7692
7693 if (chan->state != BT_CONNECTED)
7694 goto drop;
7695
7696 switch (chan->mode) {
7697 case L2CAP_MODE_LE_FLOWCTL:
7698 case L2CAP_MODE_EXT_FLOWCTL:
7699 if (l2cap_ecred_data_rcv(chan, skb) < 0)
7700 goto drop;
7701
7702 goto done;
7703
7704 case L2CAP_MODE_BASIC:
7705 /* If socket recv buffers overflows we drop data here
7706 * which is *bad* because L2CAP has to be reliable.
7707 * But we don't have any other choice. L2CAP doesn't
7708 * provide flow control mechanism. */
7709
7710 if (chan->imtu < skb->len) {
7711 BT_ERR("Dropping L2CAP data: receive buffer overflow");
7712 goto drop;
7713 }
7714
7715 if (!chan->ops->recv(chan, skb))
7716 goto done;
7717 break;
7718
7719 case L2CAP_MODE_ERTM:
7720 case L2CAP_MODE_STREAMING:
7721 l2cap_data_rcv(chan, skb);
7722 goto done;
7723
7724 default:
7725 BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode);
7726 break;
7727 }
7728
7729 drop:
7730 kfree_skb(skb);
7731
7732 done:
7733 l2cap_chan_unlock(chan);
7734 l2cap_chan_put(chan);
7735 }
7736
l2cap_conless_channel(struct l2cap_conn * conn,__le16 psm,struct sk_buff * skb)7737 static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm,
7738 struct sk_buff *skb)
7739 {
7740 struct hci_conn *hcon = conn->hcon;
7741 struct l2cap_chan *chan;
7742
7743 if (hcon->type != ACL_LINK)
7744 goto free_skb;
7745
7746 chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst,
7747 ACL_LINK);
7748 if (!chan)
7749 goto free_skb;
7750
7751 BT_DBG("chan %p, len %d", chan, skb->len);
7752
7753 if (chan->state != BT_BOUND && chan->state != BT_CONNECTED)
7754 goto drop;
7755
7756 if (chan->imtu < skb->len)
7757 goto drop;
7758
7759 /* Store remote BD_ADDR and PSM for msg_name */
7760 bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst);
7761 bt_cb(skb)->l2cap.psm = psm;
7762
7763 if (!chan->ops->recv(chan, skb)) {
7764 l2cap_chan_put(chan);
7765 return;
7766 }
7767
7768 drop:
7769 l2cap_chan_put(chan);
7770 free_skb:
7771 kfree_skb(skb);
7772 }
7773
l2cap_recv_frame(struct l2cap_conn * conn,struct sk_buff * skb)7774 static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
7775 {
7776 struct l2cap_hdr *lh = (void *) skb->data;
7777 struct hci_conn *hcon = conn->hcon;
7778 u16 cid, len;
7779 __le16 psm;
7780
7781 if (hcon->state != BT_CONNECTED) {
7782 BT_DBG("queueing pending rx skb");
7783 skb_queue_tail(&conn->pending_rx, skb);
7784 return;
7785 }
7786
7787 skb_pull(skb, L2CAP_HDR_SIZE);
7788 cid = __le16_to_cpu(lh->cid);
7789 len = __le16_to_cpu(lh->len);
7790
7791 if (len != skb->len) {
7792 kfree_skb(skb);
7793 return;
7794 }
7795
7796 /* Since we can't actively block incoming LE connections we must
7797 * at least ensure that we ignore incoming data from them.
7798 */
7799 if (hcon->type == LE_LINK &&
7800 hci_bdaddr_list_lookup(&hcon->hdev->reject_list, &hcon->dst,
7801 bdaddr_dst_type(hcon))) {
7802 kfree_skb(skb);
7803 return;
7804 }
7805
7806 BT_DBG("len %d, cid 0x%4.4x", len, cid);
7807
7808 switch (cid) {
7809 case L2CAP_CID_SIGNALING:
7810 l2cap_sig_channel(conn, skb);
7811 break;
7812
7813 case L2CAP_CID_CONN_LESS:
7814 psm = get_unaligned((__le16 *) skb->data);
7815 skb_pull(skb, L2CAP_PSMLEN_SIZE);
7816 l2cap_conless_channel(conn, psm, skb);
7817 break;
7818
7819 case L2CAP_CID_LE_SIGNALING:
7820 l2cap_le_sig_channel(conn, skb);
7821 break;
7822
7823 default:
7824 l2cap_data_channel(conn, cid, skb);
7825 break;
7826 }
7827 }
7828
process_pending_rx(struct work_struct * work)7829 static void process_pending_rx(struct work_struct *work)
7830 {
7831 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
7832 pending_rx_work);
7833 struct sk_buff *skb;
7834
7835 BT_DBG("");
7836
7837 while ((skb = skb_dequeue(&conn->pending_rx)))
7838 l2cap_recv_frame(conn, skb);
7839 }
7840
l2cap_conn_add(struct hci_conn * hcon)7841 static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon)
7842 {
7843 struct l2cap_conn *conn = hcon->l2cap_data;
7844 struct hci_chan *hchan;
7845
7846 if (conn)
7847 return conn;
7848
7849 hchan = hci_chan_create(hcon);
7850 if (!hchan)
7851 return NULL;
7852
7853 conn = kzalloc(sizeof(*conn), GFP_KERNEL);
7854 if (!conn) {
7855 hci_chan_del(hchan);
7856 return NULL;
7857 }
7858
7859 kref_init(&conn->ref);
7860 hcon->l2cap_data = conn;
7861 conn->hcon = hci_conn_get(hcon);
7862 conn->hchan = hchan;
7863
7864 BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan);
7865
7866 switch (hcon->type) {
7867 case LE_LINK:
7868 if (hcon->hdev->le_mtu) {
7869 conn->mtu = hcon->hdev->le_mtu;
7870 break;
7871 }
7872 fallthrough;
7873 default:
7874 conn->mtu = hcon->hdev->acl_mtu;
7875 break;
7876 }
7877
7878 conn->feat_mask = 0;
7879
7880 conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS;
7881
7882 if (hcon->type == ACL_LINK &&
7883 hci_dev_test_flag(hcon->hdev, HCI_HS_ENABLED))
7884 conn->local_fixed_chan |= L2CAP_FC_A2MP;
7885
7886 if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) &&
7887 (bredr_sc_enabled(hcon->hdev) ||
7888 hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP)))
7889 conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR;
7890
7891 mutex_init(&conn->ident_lock);
7892 mutex_init(&conn->chan_lock);
7893
7894 INIT_LIST_HEAD(&conn->chan_l);
7895 INIT_LIST_HEAD(&conn->users);
7896
7897 INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout);
7898
7899 skb_queue_head_init(&conn->pending_rx);
7900 INIT_WORK(&conn->pending_rx_work, process_pending_rx);
7901 INIT_WORK(&conn->id_addr_update_work, l2cap_conn_update_id_addr);
7902
7903 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
7904
7905 return conn;
7906 }
7907
is_valid_psm(u16 psm,u8 dst_type)7908 static bool is_valid_psm(u16 psm, u8 dst_type) {
7909 if (!psm)
7910 return false;
7911
7912 if (bdaddr_type_is_le(dst_type))
7913 return (psm <= 0x00ff);
7914
7915 /* PSM must be odd and lsb of upper byte must be 0 */
7916 return ((psm & 0x0101) == 0x0001);
7917 }
7918
7919 struct l2cap_chan_data {
7920 struct l2cap_chan *chan;
7921 struct pid *pid;
7922 int count;
7923 };
7924
l2cap_chan_by_pid(struct l2cap_chan * chan,void * data)7925 static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data)
7926 {
7927 struct l2cap_chan_data *d = data;
7928 struct pid *pid;
7929
7930 if (chan == d->chan)
7931 return;
7932
7933 if (!test_bit(FLAG_DEFER_SETUP, &chan->flags))
7934 return;
7935
7936 pid = chan->ops->get_peer_pid(chan);
7937
7938 /* Only count deferred channels with the same PID/PSM */
7939 if (d->pid != pid || chan->psm != d->chan->psm || chan->ident ||
7940 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
7941 return;
7942
7943 d->count++;
7944 }
7945
l2cap_chan_connect(struct l2cap_chan * chan,__le16 psm,u16 cid,bdaddr_t * dst,u8 dst_type)7946 int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
7947 bdaddr_t *dst, u8 dst_type)
7948 {
7949 struct l2cap_conn *conn;
7950 struct hci_conn *hcon;
7951 struct hci_dev *hdev;
7952 int err;
7953
7954 BT_DBG("%pMR -> %pMR (type %u) psm 0x%4.4x mode 0x%2.2x", &chan->src,
7955 dst, dst_type, __le16_to_cpu(psm), chan->mode);
7956
7957 hdev = hci_get_route(dst, &chan->src, chan->src_type);
7958 if (!hdev)
7959 return -EHOSTUNREACH;
7960
7961 hci_dev_lock(hdev);
7962
7963 if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid &&
7964 chan->chan_type != L2CAP_CHAN_RAW) {
7965 err = -EINVAL;
7966 goto done;
7967 }
7968
7969 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) {
7970 err = -EINVAL;
7971 goto done;
7972 }
7973
7974 if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) {
7975 err = -EINVAL;
7976 goto done;
7977 }
7978
7979 switch (chan->mode) {
7980 case L2CAP_MODE_BASIC:
7981 break;
7982 case L2CAP_MODE_LE_FLOWCTL:
7983 break;
7984 case L2CAP_MODE_EXT_FLOWCTL:
7985 if (!enable_ecred) {
7986 err = -EOPNOTSUPP;
7987 goto done;
7988 }
7989 break;
7990 case L2CAP_MODE_ERTM:
7991 case L2CAP_MODE_STREAMING:
7992 if (!disable_ertm)
7993 break;
7994 fallthrough;
7995 default:
7996 err = -EOPNOTSUPP;
7997 goto done;
7998 }
7999
8000 switch (chan->state) {
8001 case BT_CONNECT:
8002 case BT_CONNECT2:
8003 case BT_CONFIG:
8004 /* Already connecting */
8005 err = 0;
8006 goto done;
8007
8008 case BT_CONNECTED:
8009 /* Already connected */
8010 err = -EISCONN;
8011 goto done;
8012
8013 case BT_OPEN:
8014 case BT_BOUND:
8015 /* Can connect */
8016 break;
8017
8018 default:
8019 err = -EBADFD;
8020 goto done;
8021 }
8022
8023 /* Set destination address and psm */
8024 bacpy(&chan->dst, dst);
8025 chan->dst_type = dst_type;
8026
8027 chan->psm = psm;
8028 chan->dcid = cid;
8029
8030 if (bdaddr_type_is_le(dst_type)) {
8031 /* Convert from L2CAP channel address type to HCI address type
8032 */
8033 if (dst_type == BDADDR_LE_PUBLIC)
8034 dst_type = ADDR_LE_DEV_PUBLIC;
8035 else
8036 dst_type = ADDR_LE_DEV_RANDOM;
8037
8038 if (hci_dev_test_flag(hdev, HCI_ADVERTISING))
8039 hcon = hci_connect_le(hdev, dst, dst_type,
8040 chan->sec_level,
8041 HCI_LE_CONN_TIMEOUT,
8042 HCI_ROLE_SLAVE, NULL);
8043 else
8044 hcon = hci_connect_le_scan(hdev, dst, dst_type,
8045 chan->sec_level,
8046 HCI_LE_CONN_TIMEOUT,
8047 CONN_REASON_L2CAP_CHAN);
8048
8049 } else {
8050 u8 auth_type = l2cap_get_auth_type(chan);
8051 hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type,
8052 CONN_REASON_L2CAP_CHAN);
8053 }
8054
8055 if (IS_ERR(hcon)) {
8056 err = PTR_ERR(hcon);
8057 goto done;
8058 }
8059
8060 conn = l2cap_conn_add(hcon);
8061 if (!conn) {
8062 hci_conn_drop(hcon);
8063 err = -ENOMEM;
8064 goto done;
8065 }
8066
8067 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) {
8068 struct l2cap_chan_data data;
8069
8070 data.chan = chan;
8071 data.pid = chan->ops->get_peer_pid(chan);
8072 data.count = 1;
8073
8074 l2cap_chan_list(conn, l2cap_chan_by_pid, &data);
8075
8076 /* Check if there isn't too many channels being connected */
8077 if (data.count > L2CAP_ECRED_CONN_SCID_MAX) {
8078 hci_conn_drop(hcon);
8079 err = -EPROTO;
8080 goto done;
8081 }
8082 }
8083
8084 mutex_lock(&conn->chan_lock);
8085 l2cap_chan_lock(chan);
8086
8087 if (cid && __l2cap_get_chan_by_dcid(conn, cid)) {
8088 hci_conn_drop(hcon);
8089 err = -EBUSY;
8090 goto chan_unlock;
8091 }
8092
8093 /* Update source addr of the socket */
8094 bacpy(&chan->src, &hcon->src);
8095 chan->src_type = bdaddr_src_type(hcon);
8096
8097 __l2cap_chan_add(conn, chan);
8098
8099 /* l2cap_chan_add takes its own ref so we can drop this one */
8100 hci_conn_drop(hcon);
8101
8102 l2cap_state_change(chan, BT_CONNECT);
8103 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
8104
8105 /* Release chan->sport so that it can be reused by other
8106 * sockets (as it's only used for listening sockets).
8107 */
8108 write_lock(&chan_list_lock);
8109 chan->sport = 0;
8110 write_unlock(&chan_list_lock);
8111
8112 if (hcon->state == BT_CONNECTED) {
8113 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
8114 __clear_chan_timer(chan);
8115 if (l2cap_chan_check_security(chan, true))
8116 l2cap_state_change(chan, BT_CONNECTED);
8117 } else
8118 l2cap_do_start(chan);
8119 }
8120
8121 err = 0;
8122
8123 chan_unlock:
8124 l2cap_chan_unlock(chan);
8125 mutex_unlock(&conn->chan_lock);
8126 done:
8127 hci_dev_unlock(hdev);
8128 hci_dev_put(hdev);
8129 return err;
8130 }
8131 EXPORT_SYMBOL_GPL(l2cap_chan_connect);
8132
l2cap_ecred_reconfigure(struct l2cap_chan * chan)8133 static void l2cap_ecred_reconfigure(struct l2cap_chan *chan)
8134 {
8135 struct l2cap_conn *conn = chan->conn;
8136 struct {
8137 struct l2cap_ecred_reconf_req req;
8138 __le16 scid;
8139 } pdu;
8140
8141 pdu.req.mtu = cpu_to_le16(chan->imtu);
8142 pdu.req.mps = cpu_to_le16(chan->mps);
8143 pdu.scid = cpu_to_le16(chan->scid);
8144
8145 chan->ident = l2cap_get_ident(conn);
8146
8147 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ,
8148 sizeof(pdu), &pdu);
8149 }
8150
l2cap_chan_reconfigure(struct l2cap_chan * chan,__u16 mtu)8151 int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu)
8152 {
8153 if (chan->imtu > mtu)
8154 return -EINVAL;
8155
8156 BT_DBG("chan %p mtu 0x%4.4x", chan, mtu);
8157
8158 chan->imtu = mtu;
8159
8160 l2cap_ecred_reconfigure(chan);
8161
8162 return 0;
8163 }
8164
8165 /* ---- L2CAP interface with lower layer (HCI) ---- */
8166
l2cap_connect_ind(struct hci_dev * hdev,bdaddr_t * bdaddr)8167 int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr)
8168 {
8169 int exact = 0, lm1 = 0, lm2 = 0;
8170 struct l2cap_chan *c;
8171
8172 BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr);
8173
8174 /* Find listening sockets and check their link_mode */
8175 read_lock(&chan_list_lock);
8176 list_for_each_entry(c, &chan_list, global_l) {
8177 if (c->state != BT_LISTEN)
8178 continue;
8179
8180 if (!bacmp(&c->src, &hdev->bdaddr)) {
8181 lm1 |= HCI_LM_ACCEPT;
8182 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
8183 lm1 |= HCI_LM_MASTER;
8184 exact++;
8185 } else if (!bacmp(&c->src, BDADDR_ANY)) {
8186 lm2 |= HCI_LM_ACCEPT;
8187 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
8188 lm2 |= HCI_LM_MASTER;
8189 }
8190 }
8191 read_unlock(&chan_list_lock);
8192
8193 return exact ? lm1 : lm2;
8194 }
8195
8196 /* Find the next fixed channel in BT_LISTEN state, continue iteration
8197 * from an existing channel in the list or from the beginning of the
8198 * global list (by passing NULL as first parameter).
8199 */
l2cap_global_fixed_chan(struct l2cap_chan * c,struct hci_conn * hcon)8200 static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c,
8201 struct hci_conn *hcon)
8202 {
8203 u8 src_type = bdaddr_src_type(hcon);
8204
8205 read_lock(&chan_list_lock);
8206
8207 if (c)
8208 c = list_next_entry(c, global_l);
8209 else
8210 c = list_entry(chan_list.next, typeof(*c), global_l);
8211
8212 list_for_each_entry_from(c, &chan_list, global_l) {
8213 if (c->chan_type != L2CAP_CHAN_FIXED)
8214 continue;
8215 if (c->state != BT_LISTEN)
8216 continue;
8217 if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY))
8218 continue;
8219 if (src_type != c->src_type)
8220 continue;
8221
8222 c = l2cap_chan_hold_unless_zero(c);
8223 read_unlock(&chan_list_lock);
8224 return c;
8225 }
8226
8227 read_unlock(&chan_list_lock);
8228
8229 return NULL;
8230 }
8231
l2cap_connect_cfm(struct hci_conn * hcon,u8 status)8232 static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status)
8233 {
8234 struct hci_dev *hdev = hcon->hdev;
8235 struct l2cap_conn *conn;
8236 struct l2cap_chan *pchan;
8237 u8 dst_type;
8238
8239 if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
8240 return;
8241
8242 BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status);
8243
8244 if (status) {
8245 l2cap_conn_del(hcon, bt_to_errno(status));
8246 return;
8247 }
8248
8249 conn = l2cap_conn_add(hcon);
8250 if (!conn)
8251 return;
8252
8253 dst_type = bdaddr_dst_type(hcon);
8254
8255 /* If device is blocked, do not create channels for it */
8256 if (hci_bdaddr_list_lookup(&hdev->reject_list, &hcon->dst, dst_type))
8257 return;
8258
8259 /* Find fixed channels and notify them of the new connection. We
8260 * use multiple individual lookups, continuing each time where
8261 * we left off, because the list lock would prevent calling the
8262 * potentially sleeping l2cap_chan_lock() function.
8263 */
8264 pchan = l2cap_global_fixed_chan(NULL, hcon);
8265 while (pchan) {
8266 struct l2cap_chan *chan, *next;
8267
8268 /* Client fixed channels should override server ones */
8269 if (__l2cap_get_chan_by_dcid(conn, pchan->scid))
8270 goto next;
8271
8272 l2cap_chan_lock(pchan);
8273 chan = pchan->ops->new_connection(pchan);
8274 if (chan) {
8275 bacpy(&chan->src, &hcon->src);
8276 bacpy(&chan->dst, &hcon->dst);
8277 chan->src_type = bdaddr_src_type(hcon);
8278 chan->dst_type = dst_type;
8279
8280 __l2cap_chan_add(conn, chan);
8281 }
8282
8283 l2cap_chan_unlock(pchan);
8284 next:
8285 next = l2cap_global_fixed_chan(pchan, hcon);
8286 l2cap_chan_put(pchan);
8287 pchan = next;
8288 }
8289
8290 l2cap_conn_ready(conn);
8291 }
8292
l2cap_disconn_ind(struct hci_conn * hcon)8293 int l2cap_disconn_ind(struct hci_conn *hcon)
8294 {
8295 struct l2cap_conn *conn = hcon->l2cap_data;
8296
8297 BT_DBG("hcon %p", hcon);
8298
8299 if (!conn)
8300 return HCI_ERROR_REMOTE_USER_TERM;
8301 return conn->disc_reason;
8302 }
8303
l2cap_disconn_cfm(struct hci_conn * hcon,u8 reason)8304 static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)
8305 {
8306 if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
8307 return;
8308
8309 BT_DBG("hcon %p reason %d", hcon, reason);
8310
8311 l2cap_conn_del(hcon, bt_to_errno(reason));
8312 }
8313
l2cap_check_encryption(struct l2cap_chan * chan,u8 encrypt)8314 static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt)
8315 {
8316 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
8317 return;
8318
8319 if (encrypt == 0x00) {
8320 if (chan->sec_level == BT_SECURITY_MEDIUM) {
8321 __set_chan_timer(chan, L2CAP_ENC_TIMEOUT);
8322 } else if (chan->sec_level == BT_SECURITY_HIGH ||
8323 chan->sec_level == BT_SECURITY_FIPS)
8324 l2cap_chan_close(chan, ECONNREFUSED);
8325 } else {
8326 if (chan->sec_level == BT_SECURITY_MEDIUM)
8327 __clear_chan_timer(chan);
8328 }
8329 }
8330
l2cap_security_cfm(struct hci_conn * hcon,u8 status,u8 encrypt)8331 static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
8332 {
8333 struct l2cap_conn *conn = hcon->l2cap_data;
8334 struct l2cap_chan *chan;
8335
8336 if (!conn)
8337 return;
8338
8339 BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt);
8340
8341 mutex_lock(&conn->chan_lock);
8342
8343 list_for_each_entry(chan, &conn->chan_l, list) {
8344 l2cap_chan_lock(chan);
8345
8346 BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid,
8347 state_to_string(chan->state));
8348
8349 if (chan->scid == L2CAP_CID_A2MP) {
8350 l2cap_chan_unlock(chan);
8351 continue;
8352 }
8353
8354 if (!status && encrypt)
8355 chan->sec_level = hcon->sec_level;
8356
8357 if (!__l2cap_no_conn_pending(chan)) {
8358 l2cap_chan_unlock(chan);
8359 continue;
8360 }
8361
8362 if (!status && (chan->state == BT_CONNECTED ||
8363 chan->state == BT_CONFIG)) {
8364 chan->ops->resume(chan);
8365 l2cap_check_encryption(chan, encrypt);
8366 l2cap_chan_unlock(chan);
8367 continue;
8368 }
8369
8370 if (chan->state == BT_CONNECT) {
8371 if (!status && l2cap_check_enc_key_size(hcon))
8372 l2cap_start_connection(chan);
8373 else
8374 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
8375 } else if (chan->state == BT_CONNECT2 &&
8376 !(chan->mode == L2CAP_MODE_EXT_FLOWCTL ||
8377 chan->mode == L2CAP_MODE_LE_FLOWCTL)) {
8378 struct l2cap_conn_rsp rsp;
8379 __u16 res, stat;
8380
8381 if (!status && l2cap_check_enc_key_size(hcon)) {
8382 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
8383 res = L2CAP_CR_PEND;
8384 stat = L2CAP_CS_AUTHOR_PEND;
8385 chan->ops->defer(chan);
8386 } else {
8387 l2cap_state_change(chan, BT_CONFIG);
8388 res = L2CAP_CR_SUCCESS;
8389 stat = L2CAP_CS_NO_INFO;
8390 }
8391 } else {
8392 l2cap_state_change(chan, BT_DISCONN);
8393 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
8394 res = L2CAP_CR_SEC_BLOCK;
8395 stat = L2CAP_CS_NO_INFO;
8396 }
8397
8398 rsp.scid = cpu_to_le16(chan->dcid);
8399 rsp.dcid = cpu_to_le16(chan->scid);
8400 rsp.result = cpu_to_le16(res);
8401 rsp.status = cpu_to_le16(stat);
8402 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
8403 sizeof(rsp), &rsp);
8404
8405 if (!test_bit(CONF_REQ_SENT, &chan->conf_state) &&
8406 res == L2CAP_CR_SUCCESS) {
8407 char buf[128];
8408 set_bit(CONF_REQ_SENT, &chan->conf_state);
8409 l2cap_send_cmd(conn, l2cap_get_ident(conn),
8410 L2CAP_CONF_REQ,
8411 l2cap_build_conf_req(chan, buf, sizeof(buf)),
8412 buf);
8413 chan->num_conf_req++;
8414 }
8415 }
8416
8417 l2cap_chan_unlock(chan);
8418 }
8419
8420 mutex_unlock(&conn->chan_lock);
8421 }
8422
l2cap_recv_acldata(struct hci_conn * hcon,struct sk_buff * skb,u16 flags)8423 void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
8424 {
8425 struct l2cap_conn *conn = hcon->l2cap_data;
8426 struct l2cap_hdr *hdr;
8427 int len;
8428
8429 /* For AMP controller do not create l2cap conn */
8430 if (!conn && hcon->hdev->dev_type != HCI_PRIMARY)
8431 goto drop;
8432
8433 if (!conn)
8434 conn = l2cap_conn_add(hcon);
8435
8436 if (!conn)
8437 goto drop;
8438
8439 BT_DBG("conn %p len %d flags 0x%x", conn, skb->len, flags);
8440
8441 switch (flags) {
8442 case ACL_START:
8443 case ACL_START_NO_FLUSH:
8444 case ACL_COMPLETE:
8445 if (conn->rx_len) {
8446 BT_ERR("Unexpected start frame (len %d)", skb->len);
8447 kfree_skb(conn->rx_skb);
8448 conn->rx_skb = NULL;
8449 conn->rx_len = 0;
8450 l2cap_conn_unreliable(conn, ECOMM);
8451 }
8452
8453 /* Start fragment always begin with Basic L2CAP header */
8454 if (skb->len < L2CAP_HDR_SIZE) {
8455 BT_ERR("Frame is too short (len %d)", skb->len);
8456 l2cap_conn_unreliable(conn, ECOMM);
8457 goto drop;
8458 }
8459
8460 hdr = (struct l2cap_hdr *) skb->data;
8461 len = __le16_to_cpu(hdr->len) + L2CAP_HDR_SIZE;
8462
8463 if (len == skb->len) {
8464 /* Complete frame received */
8465 l2cap_recv_frame(conn, skb);
8466 return;
8467 }
8468
8469 BT_DBG("Start: total len %d, frag len %d", len, skb->len);
8470
8471 if (skb->len > len) {
8472 BT_ERR("Frame is too long (len %d, expected len %d)",
8473 skb->len, len);
8474 l2cap_conn_unreliable(conn, ECOMM);
8475 goto drop;
8476 }
8477
8478 /* Allocate skb for the complete frame (with header) */
8479 conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL);
8480 if (!conn->rx_skb)
8481 goto drop;
8482
8483 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len),
8484 skb->len);
8485 conn->rx_len = len - skb->len;
8486 break;
8487
8488 case ACL_CONT:
8489 BT_DBG("Cont: frag len %d (expecting %d)", skb->len, conn->rx_len);
8490
8491 if (!conn->rx_len) {
8492 BT_ERR("Unexpected continuation frame (len %d)", skb->len);
8493 l2cap_conn_unreliable(conn, ECOMM);
8494 goto drop;
8495 }
8496
8497 if (skb->len > conn->rx_len) {
8498 BT_ERR("Fragment is too long (len %d, expected %d)",
8499 skb->len, conn->rx_len);
8500 kfree_skb(conn->rx_skb);
8501 conn->rx_skb = NULL;
8502 conn->rx_len = 0;
8503 l2cap_conn_unreliable(conn, ECOMM);
8504 goto drop;
8505 }
8506
8507 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len),
8508 skb->len);
8509 conn->rx_len -= skb->len;
8510
8511 if (!conn->rx_len) {
8512 /* Complete frame received. l2cap_recv_frame
8513 * takes ownership of the skb so set the global
8514 * rx_skb pointer to NULL first.
8515 */
8516 struct sk_buff *rx_skb = conn->rx_skb;
8517 conn->rx_skb = NULL;
8518 l2cap_recv_frame(conn, rx_skb);
8519 }
8520 break;
8521 }
8522
8523 drop:
8524 kfree_skb(skb);
8525 }
8526
8527 static struct hci_cb l2cap_cb = {
8528 .name = "L2CAP",
8529 .connect_cfm = l2cap_connect_cfm,
8530 .disconn_cfm = l2cap_disconn_cfm,
8531 .security_cfm = l2cap_security_cfm,
8532 };
8533
l2cap_debugfs_show(struct seq_file * f,void * p)8534 static int l2cap_debugfs_show(struct seq_file *f, void *p)
8535 {
8536 struct l2cap_chan *c;
8537
8538 read_lock(&chan_list_lock);
8539
8540 list_for_each_entry(c, &chan_list, global_l) {
8541 seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n",
8542 &c->src, c->src_type, &c->dst, c->dst_type,
8543 c->state, __le16_to_cpu(c->psm),
8544 c->scid, c->dcid, c->imtu, c->omtu,
8545 c->sec_level, c->mode);
8546 }
8547
8548 read_unlock(&chan_list_lock);
8549
8550 return 0;
8551 }
8552
8553 DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs);
8554
8555 static struct dentry *l2cap_debugfs;
8556
l2cap_init(void)8557 int __init l2cap_init(void)
8558 {
8559 int err;
8560
8561 err = l2cap_init_sockets();
8562 if (err < 0)
8563 return err;
8564
8565 hci_register_cb(&l2cap_cb);
8566
8567 if (IS_ERR_OR_NULL(bt_debugfs))
8568 return 0;
8569
8570 l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs,
8571 NULL, &l2cap_debugfs_fops);
8572
8573 return 0;
8574 }
8575
l2cap_exit(void)8576 void l2cap_exit(void)
8577 {
8578 debugfs_remove(l2cap_debugfs);
8579 hci_unregister_cb(&l2cap_cb);
8580 l2cap_cleanup_sockets();
8581 }
8582
8583 module_param(disable_ertm, bool, 0644);
8584 MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode");
8585
8586 module_param(enable_ecred, bool, 0644);
8587 MODULE_PARM_DESC(enable_ecred, "Enable enhanced credit flow control mode");
8588