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 if (cmd_len < sizeof(struct l2cap_conn_req))
4276 return -EPROTO;
4277
4278 l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP, 0);
4279 return 0;
4280 }
4281
l2cap_connect_create_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4282 static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
4283 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4284 u8 *data)
4285 {
4286 struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data;
4287 u16 scid, dcid, result, status;
4288 struct l2cap_chan *chan;
4289 u8 req[128];
4290 int err;
4291
4292 if (cmd_len < sizeof(*rsp))
4293 return -EPROTO;
4294
4295 scid = __le16_to_cpu(rsp->scid);
4296 dcid = __le16_to_cpu(rsp->dcid);
4297 result = __le16_to_cpu(rsp->result);
4298 status = __le16_to_cpu(rsp->status);
4299
4300 if (result == L2CAP_CR_SUCCESS && (dcid < L2CAP_CID_DYN_START ||
4301 dcid > L2CAP_CID_DYN_END))
4302 return -EPROTO;
4303
4304 BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x",
4305 dcid, scid, result, status);
4306
4307 mutex_lock(&conn->chan_lock);
4308
4309 if (scid) {
4310 chan = __l2cap_get_chan_by_scid(conn, scid);
4311 if (!chan) {
4312 err = -EBADSLT;
4313 goto unlock;
4314 }
4315 } else {
4316 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
4317 if (!chan) {
4318 err = -EBADSLT;
4319 goto unlock;
4320 }
4321 }
4322
4323 chan = l2cap_chan_hold_unless_zero(chan);
4324 if (!chan) {
4325 err = -EBADSLT;
4326 goto unlock;
4327 }
4328
4329 err = 0;
4330
4331 l2cap_chan_lock(chan);
4332
4333 switch (result) {
4334 case L2CAP_CR_SUCCESS:
4335 if (__l2cap_get_chan_by_dcid(conn, dcid)) {
4336 err = -EBADSLT;
4337 break;
4338 }
4339
4340 l2cap_state_change(chan, BT_CONFIG);
4341 chan->ident = 0;
4342 chan->dcid = dcid;
4343 clear_bit(CONF_CONNECT_PEND, &chan->conf_state);
4344
4345 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
4346 break;
4347
4348 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4349 l2cap_build_conf_req(chan, req, sizeof(req)), req);
4350 chan->num_conf_req++;
4351 break;
4352
4353 case L2CAP_CR_PEND:
4354 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
4355 break;
4356
4357 default:
4358 l2cap_chan_del(chan, ECONNREFUSED);
4359 break;
4360 }
4361
4362 l2cap_chan_unlock(chan);
4363 l2cap_chan_put(chan);
4364
4365 unlock:
4366 mutex_unlock(&conn->chan_lock);
4367
4368 return err;
4369 }
4370
set_default_fcs(struct l2cap_chan * chan)4371 static inline void set_default_fcs(struct l2cap_chan *chan)
4372 {
4373 /* FCS is enabled only in ERTM or streaming mode, if one or both
4374 * sides request it.
4375 */
4376 if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING)
4377 chan->fcs = L2CAP_FCS_NONE;
4378 else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state))
4379 chan->fcs = L2CAP_FCS_CRC16;
4380 }
4381
l2cap_send_efs_conf_rsp(struct l2cap_chan * chan,void * data,u8 ident,u16 flags)4382 static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data,
4383 u8 ident, u16 flags)
4384 {
4385 struct l2cap_conn *conn = chan->conn;
4386
4387 BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident,
4388 flags);
4389
4390 clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
4391 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
4392
4393 l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP,
4394 l2cap_build_conf_rsp(chan, data,
4395 L2CAP_CONF_SUCCESS, flags), data);
4396 }
4397
cmd_reject_invalid_cid(struct l2cap_conn * conn,u8 ident,u16 scid,u16 dcid)4398 static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident,
4399 u16 scid, u16 dcid)
4400 {
4401 struct l2cap_cmd_rej_cid rej;
4402
4403 rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID);
4404 rej.scid = __cpu_to_le16(scid);
4405 rej.dcid = __cpu_to_le16(dcid);
4406
4407 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
4408 }
4409
l2cap_config_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4410 static inline int l2cap_config_req(struct l2cap_conn *conn,
4411 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4412 u8 *data)
4413 {
4414 struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
4415 u16 dcid, flags;
4416 u8 rsp[64];
4417 struct l2cap_chan *chan;
4418 int len, err = 0;
4419
4420 if (cmd_len < sizeof(*req))
4421 return -EPROTO;
4422
4423 dcid = __le16_to_cpu(req->dcid);
4424 flags = __le16_to_cpu(req->flags);
4425
4426 BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags);
4427
4428 chan = l2cap_get_chan_by_scid(conn, dcid);
4429 if (!chan) {
4430 cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0);
4431 return 0;
4432 }
4433
4434 if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2 &&
4435 chan->state != BT_CONNECTED) {
4436 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
4437 chan->dcid);
4438 goto unlock;
4439 }
4440
4441 /* Reject if config buffer is too small. */
4442 len = cmd_len - sizeof(*req);
4443 if (chan->conf_len + len > sizeof(chan->conf_req)) {
4444 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4445 l2cap_build_conf_rsp(chan, rsp,
4446 L2CAP_CONF_REJECT, flags), rsp);
4447 goto unlock;
4448 }
4449
4450 /* Store config. */
4451 memcpy(chan->conf_req + chan->conf_len, req->data, len);
4452 chan->conf_len += len;
4453
4454 if (flags & L2CAP_CONF_FLAG_CONTINUATION) {
4455 /* Incomplete config. Send empty response. */
4456 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4457 l2cap_build_conf_rsp(chan, rsp,
4458 L2CAP_CONF_SUCCESS, flags), rsp);
4459 goto unlock;
4460 }
4461
4462 /* Complete config. */
4463 len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp));
4464 if (len < 0) {
4465 l2cap_send_disconn_req(chan, ECONNRESET);
4466 goto unlock;
4467 }
4468
4469 chan->ident = cmd->ident;
4470 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp);
4471 if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP)
4472 chan->num_conf_rsp++;
4473
4474 /* Reset config buffer. */
4475 chan->conf_len = 0;
4476
4477 if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state))
4478 goto unlock;
4479
4480 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
4481 set_default_fcs(chan);
4482
4483 if (chan->mode == L2CAP_MODE_ERTM ||
4484 chan->mode == L2CAP_MODE_STREAMING)
4485 err = l2cap_ertm_init(chan);
4486
4487 if (err < 0)
4488 l2cap_send_disconn_req(chan, -err);
4489 else
4490 l2cap_chan_ready(chan);
4491
4492 goto unlock;
4493 }
4494
4495 if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) {
4496 u8 buf[64];
4497 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4498 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4499 chan->num_conf_req++;
4500 }
4501
4502 /* Got Conf Rsp PENDING from remote side and assume we sent
4503 Conf Rsp PENDING in the code above */
4504 if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) &&
4505 test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4506
4507 /* check compatibility */
4508
4509 /* Send rsp for BR/EDR channel */
4510 if (!chan->hs_hcon)
4511 l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags);
4512 else
4513 chan->ident = cmd->ident;
4514 }
4515
4516 unlock:
4517 l2cap_chan_unlock(chan);
4518 l2cap_chan_put(chan);
4519 return err;
4520 }
4521
l2cap_config_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4522 static inline int l2cap_config_rsp(struct l2cap_conn *conn,
4523 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4524 u8 *data)
4525 {
4526 struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data;
4527 u16 scid, flags, result;
4528 struct l2cap_chan *chan;
4529 int len = cmd_len - sizeof(*rsp);
4530 int err = 0;
4531
4532 if (cmd_len < sizeof(*rsp))
4533 return -EPROTO;
4534
4535 scid = __le16_to_cpu(rsp->scid);
4536 flags = __le16_to_cpu(rsp->flags);
4537 result = __le16_to_cpu(rsp->result);
4538
4539 BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags,
4540 result, len);
4541
4542 chan = l2cap_get_chan_by_scid(conn, scid);
4543 if (!chan)
4544 return 0;
4545
4546 switch (result) {
4547 case L2CAP_CONF_SUCCESS:
4548 l2cap_conf_rfc_get(chan, rsp->data, len);
4549 clear_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4550 break;
4551
4552 case L2CAP_CONF_PENDING:
4553 set_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4554
4555 if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4556 char buf[64];
4557
4558 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4559 buf, sizeof(buf), &result);
4560 if (len < 0) {
4561 l2cap_send_disconn_req(chan, ECONNRESET);
4562 goto done;
4563 }
4564
4565 if (!chan->hs_hcon) {
4566 l2cap_send_efs_conf_rsp(chan, buf, cmd->ident,
4567 0);
4568 } else {
4569 if (l2cap_check_efs(chan)) {
4570 amp_create_logical_link(chan);
4571 chan->ident = cmd->ident;
4572 }
4573 }
4574 }
4575 goto done;
4576
4577 case L2CAP_CONF_UNACCEPT:
4578 if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) {
4579 char req[64];
4580
4581 if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) {
4582 l2cap_send_disconn_req(chan, ECONNRESET);
4583 goto done;
4584 }
4585
4586 /* throw out any old stored conf requests */
4587 result = L2CAP_CONF_SUCCESS;
4588 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4589 req, sizeof(req), &result);
4590 if (len < 0) {
4591 l2cap_send_disconn_req(chan, ECONNRESET);
4592 goto done;
4593 }
4594
4595 l2cap_send_cmd(conn, l2cap_get_ident(conn),
4596 L2CAP_CONF_REQ, len, req);
4597 chan->num_conf_req++;
4598 if (result != L2CAP_CONF_SUCCESS)
4599 goto done;
4600 break;
4601 }
4602 fallthrough;
4603
4604 default:
4605 l2cap_chan_set_err(chan, ECONNRESET);
4606
4607 __set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT);
4608 l2cap_send_disconn_req(chan, ECONNRESET);
4609 goto done;
4610 }
4611
4612 if (flags & L2CAP_CONF_FLAG_CONTINUATION)
4613 goto done;
4614
4615 set_bit(CONF_INPUT_DONE, &chan->conf_state);
4616
4617 if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) {
4618 set_default_fcs(chan);
4619
4620 if (chan->mode == L2CAP_MODE_ERTM ||
4621 chan->mode == L2CAP_MODE_STREAMING)
4622 err = l2cap_ertm_init(chan);
4623
4624 if (err < 0)
4625 l2cap_send_disconn_req(chan, -err);
4626 else
4627 l2cap_chan_ready(chan);
4628 }
4629
4630 done:
4631 l2cap_chan_unlock(chan);
4632 l2cap_chan_put(chan);
4633 return err;
4634 }
4635
l2cap_disconnect_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4636 static inline int l2cap_disconnect_req(struct l2cap_conn *conn,
4637 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4638 u8 *data)
4639 {
4640 struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data;
4641 struct l2cap_disconn_rsp rsp;
4642 u16 dcid, scid;
4643 struct l2cap_chan *chan;
4644
4645 if (cmd_len != sizeof(*req))
4646 return -EPROTO;
4647
4648 scid = __le16_to_cpu(req->scid);
4649 dcid = __le16_to_cpu(req->dcid);
4650
4651 BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
4652
4653 chan = l2cap_get_chan_by_scid(conn, dcid);
4654 if (!chan) {
4655 cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid);
4656 return 0;
4657 }
4658
4659 rsp.dcid = cpu_to_le16(chan->scid);
4660 rsp.scid = cpu_to_le16(chan->dcid);
4661 l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
4662
4663 chan->ops->set_shutdown(chan);
4664
4665 l2cap_chan_unlock(chan);
4666 mutex_lock(&conn->chan_lock);
4667 l2cap_chan_lock(chan);
4668 l2cap_chan_del(chan, ECONNRESET);
4669 mutex_unlock(&conn->chan_lock);
4670
4671 chan->ops->close(chan);
4672
4673 l2cap_chan_unlock(chan);
4674 l2cap_chan_put(chan);
4675
4676 return 0;
4677 }
4678
l2cap_disconnect_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4679 static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,
4680 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4681 u8 *data)
4682 {
4683 struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data;
4684 u16 dcid, scid;
4685 struct l2cap_chan *chan;
4686
4687 if (cmd_len != sizeof(*rsp))
4688 return -EPROTO;
4689
4690 scid = __le16_to_cpu(rsp->scid);
4691 dcid = __le16_to_cpu(rsp->dcid);
4692
4693 BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
4694
4695 chan = l2cap_get_chan_by_scid(conn, scid);
4696 if (!chan) {
4697 return 0;
4698 }
4699
4700 if (chan->state != BT_DISCONN) {
4701 l2cap_chan_unlock(chan);
4702 l2cap_chan_put(chan);
4703 return 0;
4704 }
4705
4706 l2cap_chan_unlock(chan);
4707 mutex_lock(&conn->chan_lock);
4708 l2cap_chan_lock(chan);
4709 l2cap_chan_del(chan, 0);
4710 mutex_unlock(&conn->chan_lock);
4711
4712 chan->ops->close(chan);
4713
4714 l2cap_chan_unlock(chan);
4715 l2cap_chan_put(chan);
4716
4717 return 0;
4718 }
4719
l2cap_information_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4720 static inline int l2cap_information_req(struct l2cap_conn *conn,
4721 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4722 u8 *data)
4723 {
4724 struct l2cap_info_req *req = (struct l2cap_info_req *) data;
4725 u16 type;
4726
4727 if (cmd_len != sizeof(*req))
4728 return -EPROTO;
4729
4730 type = __le16_to_cpu(req->type);
4731
4732 BT_DBG("type 0x%4.4x", type);
4733
4734 if (type == L2CAP_IT_FEAT_MASK) {
4735 u8 buf[8];
4736 u32 feat_mask = l2cap_feat_mask;
4737 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4738 rsp->type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
4739 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4740 if (!disable_ertm)
4741 feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING
4742 | L2CAP_FEAT_FCS;
4743 if (conn->local_fixed_chan & L2CAP_FC_A2MP)
4744 feat_mask |= L2CAP_FEAT_EXT_FLOW
4745 | L2CAP_FEAT_EXT_WINDOW;
4746
4747 put_unaligned_le32(feat_mask, rsp->data);
4748 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4749 buf);
4750 } else if (type == L2CAP_IT_FIXED_CHAN) {
4751 u8 buf[12];
4752 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4753
4754 rsp->type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4755 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4756 rsp->data[0] = conn->local_fixed_chan;
4757 memset(rsp->data + 1, 0, 7);
4758 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4759 buf);
4760 } else {
4761 struct l2cap_info_rsp rsp;
4762 rsp.type = cpu_to_le16(type);
4763 rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP);
4764 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp),
4765 &rsp);
4766 }
4767
4768 return 0;
4769 }
4770
l2cap_information_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)4771 static inline int l2cap_information_rsp(struct l2cap_conn *conn,
4772 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4773 u8 *data)
4774 {
4775 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data;
4776 u16 type, result;
4777
4778 if (cmd_len < sizeof(*rsp))
4779 return -EPROTO;
4780
4781 type = __le16_to_cpu(rsp->type);
4782 result = __le16_to_cpu(rsp->result);
4783
4784 BT_DBG("type 0x%4.4x result 0x%2.2x", type, result);
4785
4786 /* L2CAP Info req/rsp are unbound to channels, add extra checks */
4787 if (cmd->ident != conn->info_ident ||
4788 conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
4789 return 0;
4790
4791 cancel_delayed_work(&conn->info_timer);
4792
4793 if (result != L2CAP_IR_SUCCESS) {
4794 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4795 conn->info_ident = 0;
4796
4797 l2cap_conn_start(conn);
4798
4799 return 0;
4800 }
4801
4802 switch (type) {
4803 case L2CAP_IT_FEAT_MASK:
4804 conn->feat_mask = get_unaligned_le32(rsp->data);
4805
4806 if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) {
4807 struct l2cap_info_req req;
4808 req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4809
4810 conn->info_ident = l2cap_get_ident(conn);
4811
4812 l2cap_send_cmd(conn, conn->info_ident,
4813 L2CAP_INFO_REQ, sizeof(req), &req);
4814 } else {
4815 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4816 conn->info_ident = 0;
4817
4818 l2cap_conn_start(conn);
4819 }
4820 break;
4821
4822 case L2CAP_IT_FIXED_CHAN:
4823 conn->remote_fixed_chan = rsp->data[0];
4824 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4825 conn->info_ident = 0;
4826
4827 l2cap_conn_start(conn);
4828 break;
4829 }
4830
4831 return 0;
4832 }
4833
l2cap_create_channel_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,void * data)4834 static int l2cap_create_channel_req(struct l2cap_conn *conn,
4835 struct l2cap_cmd_hdr *cmd,
4836 u16 cmd_len, void *data)
4837 {
4838 struct l2cap_create_chan_req *req = data;
4839 struct l2cap_create_chan_rsp rsp;
4840 struct l2cap_chan *chan;
4841 struct hci_dev *hdev;
4842 u16 psm, scid;
4843
4844 if (cmd_len != sizeof(*req))
4845 return -EPROTO;
4846
4847 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
4848 return -EINVAL;
4849
4850 psm = le16_to_cpu(req->psm);
4851 scid = le16_to_cpu(req->scid);
4852
4853 BT_DBG("psm 0x%2.2x, scid 0x%4.4x, amp_id %d", psm, scid, req->amp_id);
4854
4855 /* For controller id 0 make BR/EDR connection */
4856 if (req->amp_id == AMP_ID_BREDR) {
4857 l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP,
4858 req->amp_id);
4859 return 0;
4860 }
4861
4862 /* Validate AMP controller id */
4863 hdev = hci_dev_get(req->amp_id);
4864 if (!hdev)
4865 goto error;
4866
4867 if (hdev->dev_type != HCI_AMP || !test_bit(HCI_UP, &hdev->flags)) {
4868 hci_dev_put(hdev);
4869 goto error;
4870 }
4871
4872 chan = l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP,
4873 req->amp_id);
4874 if (chan) {
4875 struct amp_mgr *mgr = conn->hcon->amp_mgr;
4876 struct hci_conn *hs_hcon;
4877
4878 hs_hcon = hci_conn_hash_lookup_ba(hdev, AMP_LINK,
4879 &conn->hcon->dst);
4880 if (!hs_hcon) {
4881 hci_dev_put(hdev);
4882 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
4883 chan->dcid);
4884 return 0;
4885 }
4886
4887 BT_DBG("mgr %p bredr_chan %p hs_hcon %p", mgr, chan, hs_hcon);
4888
4889 mgr->bredr_chan = chan;
4890 chan->hs_hcon = hs_hcon;
4891 chan->fcs = L2CAP_FCS_NONE;
4892 conn->mtu = hdev->block_mtu;
4893 }
4894
4895 hci_dev_put(hdev);
4896
4897 return 0;
4898
4899 error:
4900 rsp.dcid = 0;
4901 rsp.scid = cpu_to_le16(scid);
4902 rsp.result = cpu_to_le16(L2CAP_CR_BAD_AMP);
4903 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
4904
4905 l2cap_send_cmd(conn, cmd->ident, L2CAP_CREATE_CHAN_RSP,
4906 sizeof(rsp), &rsp);
4907
4908 return 0;
4909 }
4910
l2cap_send_move_chan_req(struct l2cap_chan * chan,u8 dest_amp_id)4911 static void l2cap_send_move_chan_req(struct l2cap_chan *chan, u8 dest_amp_id)
4912 {
4913 struct l2cap_move_chan_req req;
4914 u8 ident;
4915
4916 BT_DBG("chan %p, dest_amp_id %d", chan, dest_amp_id);
4917
4918 ident = l2cap_get_ident(chan->conn);
4919 chan->ident = ident;
4920
4921 req.icid = cpu_to_le16(chan->scid);
4922 req.dest_amp_id = dest_amp_id;
4923
4924 l2cap_send_cmd(chan->conn, ident, L2CAP_MOVE_CHAN_REQ, sizeof(req),
4925 &req);
4926
4927 __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
4928 }
4929
l2cap_send_move_chan_rsp(struct l2cap_chan * chan,u16 result)4930 static void l2cap_send_move_chan_rsp(struct l2cap_chan *chan, u16 result)
4931 {
4932 struct l2cap_move_chan_rsp rsp;
4933
4934 BT_DBG("chan %p, result 0x%4.4x", chan, result);
4935
4936 rsp.icid = cpu_to_le16(chan->dcid);
4937 rsp.result = cpu_to_le16(result);
4938
4939 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_RSP,
4940 sizeof(rsp), &rsp);
4941 }
4942
l2cap_send_move_chan_cfm(struct l2cap_chan * chan,u16 result)4943 static void l2cap_send_move_chan_cfm(struct l2cap_chan *chan, u16 result)
4944 {
4945 struct l2cap_move_chan_cfm cfm;
4946
4947 BT_DBG("chan %p, result 0x%4.4x", chan, result);
4948
4949 chan->ident = l2cap_get_ident(chan->conn);
4950
4951 cfm.icid = cpu_to_le16(chan->scid);
4952 cfm.result = cpu_to_le16(result);
4953
4954 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_CFM,
4955 sizeof(cfm), &cfm);
4956
4957 __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
4958 }
4959
l2cap_send_move_chan_cfm_icid(struct l2cap_conn * conn,u16 icid)4960 static void l2cap_send_move_chan_cfm_icid(struct l2cap_conn *conn, u16 icid)
4961 {
4962 struct l2cap_move_chan_cfm cfm;
4963
4964 BT_DBG("conn %p, icid 0x%4.4x", conn, icid);
4965
4966 cfm.icid = cpu_to_le16(icid);
4967 cfm.result = cpu_to_le16(L2CAP_MC_UNCONFIRMED);
4968
4969 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_MOVE_CHAN_CFM,
4970 sizeof(cfm), &cfm);
4971 }
4972
l2cap_send_move_chan_cfm_rsp(struct l2cap_conn * conn,u8 ident,u16 icid)4973 static void l2cap_send_move_chan_cfm_rsp(struct l2cap_conn *conn, u8 ident,
4974 u16 icid)
4975 {
4976 struct l2cap_move_chan_cfm_rsp rsp;
4977
4978 BT_DBG("icid 0x%4.4x", icid);
4979
4980 rsp.icid = cpu_to_le16(icid);
4981 l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_CFM_RSP, sizeof(rsp), &rsp);
4982 }
4983
__release_logical_link(struct l2cap_chan * chan)4984 static void __release_logical_link(struct l2cap_chan *chan)
4985 {
4986 chan->hs_hchan = NULL;
4987 chan->hs_hcon = NULL;
4988
4989 /* Placeholder - release the logical link */
4990 }
4991
l2cap_logical_fail(struct l2cap_chan * chan)4992 static void l2cap_logical_fail(struct l2cap_chan *chan)
4993 {
4994 /* Logical link setup failed */
4995 if (chan->state != BT_CONNECTED) {
4996 /* Create channel failure, disconnect */
4997 l2cap_send_disconn_req(chan, ECONNRESET);
4998 return;
4999 }
5000
5001 switch (chan->move_role) {
5002 case L2CAP_MOVE_ROLE_RESPONDER:
5003 l2cap_move_done(chan);
5004 l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_SUPP);
5005 break;
5006 case L2CAP_MOVE_ROLE_INITIATOR:
5007 if (chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_COMP ||
5008 chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_CFM) {
5009 /* Remote has only sent pending or
5010 * success responses, clean up
5011 */
5012 l2cap_move_done(chan);
5013 }
5014
5015 /* Other amp move states imply that the move
5016 * has already aborted
5017 */
5018 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5019 break;
5020 }
5021 }
5022
l2cap_logical_finish_create(struct l2cap_chan * chan,struct hci_chan * hchan)5023 static void l2cap_logical_finish_create(struct l2cap_chan *chan,
5024 struct hci_chan *hchan)
5025 {
5026 struct l2cap_conf_rsp rsp;
5027
5028 chan->hs_hchan = hchan;
5029 chan->hs_hcon->l2cap_data = chan->conn;
5030
5031 l2cap_send_efs_conf_rsp(chan, &rsp, chan->ident, 0);
5032
5033 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
5034 int err;
5035
5036 set_default_fcs(chan);
5037
5038 err = l2cap_ertm_init(chan);
5039 if (err < 0)
5040 l2cap_send_disconn_req(chan, -err);
5041 else
5042 l2cap_chan_ready(chan);
5043 }
5044 }
5045
l2cap_logical_finish_move(struct l2cap_chan * chan,struct hci_chan * hchan)5046 static void l2cap_logical_finish_move(struct l2cap_chan *chan,
5047 struct hci_chan *hchan)
5048 {
5049 chan->hs_hcon = hchan->conn;
5050 chan->hs_hcon->l2cap_data = chan->conn;
5051
5052 BT_DBG("move_state %d", chan->move_state);
5053
5054 switch (chan->move_state) {
5055 case L2CAP_MOVE_WAIT_LOGICAL_COMP:
5056 /* Move confirm will be sent after a success
5057 * response is received
5058 */
5059 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
5060 break;
5061 case L2CAP_MOVE_WAIT_LOGICAL_CFM:
5062 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5063 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
5064 } else if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
5065 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
5066 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
5067 } else if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) {
5068 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
5069 l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS);
5070 }
5071 break;
5072 default:
5073 /* Move was not in expected state, free the channel */
5074 __release_logical_link(chan);
5075
5076 chan->move_state = L2CAP_MOVE_STABLE;
5077 }
5078 }
5079
5080 /* Call with chan locked */
l2cap_logical_cfm(struct l2cap_chan * chan,struct hci_chan * hchan,u8 status)5081 void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan,
5082 u8 status)
5083 {
5084 BT_DBG("chan %p, hchan %p, status %d", chan, hchan, status);
5085
5086 if (status) {
5087 l2cap_logical_fail(chan);
5088 __release_logical_link(chan);
5089 return;
5090 }
5091
5092 if (chan->state != BT_CONNECTED) {
5093 /* Ignore logical link if channel is on BR/EDR */
5094 if (chan->local_amp_id != AMP_ID_BREDR)
5095 l2cap_logical_finish_create(chan, hchan);
5096 } else {
5097 l2cap_logical_finish_move(chan, hchan);
5098 }
5099 }
5100
l2cap_move_start(struct l2cap_chan * chan)5101 void l2cap_move_start(struct l2cap_chan *chan)
5102 {
5103 BT_DBG("chan %p", chan);
5104
5105 if (chan->local_amp_id == AMP_ID_BREDR) {
5106 if (chan->chan_policy != BT_CHANNEL_POLICY_AMP_PREFERRED)
5107 return;
5108 chan->move_role = L2CAP_MOVE_ROLE_INITIATOR;
5109 chan->move_state = L2CAP_MOVE_WAIT_PREPARE;
5110 /* Placeholder - start physical link setup */
5111 } else {
5112 chan->move_role = L2CAP_MOVE_ROLE_INITIATOR;
5113 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
5114 chan->move_id = 0;
5115 l2cap_move_setup(chan);
5116 l2cap_send_move_chan_req(chan, 0);
5117 }
5118 }
5119
l2cap_do_create(struct l2cap_chan * chan,int result,u8 local_amp_id,u8 remote_amp_id)5120 static void l2cap_do_create(struct l2cap_chan *chan, int result,
5121 u8 local_amp_id, u8 remote_amp_id)
5122 {
5123 BT_DBG("chan %p state %s %u -> %u", chan, state_to_string(chan->state),
5124 local_amp_id, remote_amp_id);
5125
5126 chan->fcs = L2CAP_FCS_NONE;
5127
5128 /* Outgoing channel on AMP */
5129 if (chan->state == BT_CONNECT) {
5130 if (result == L2CAP_CR_SUCCESS) {
5131 chan->local_amp_id = local_amp_id;
5132 l2cap_send_create_chan_req(chan, remote_amp_id);
5133 } else {
5134 /* Revert to BR/EDR connect */
5135 l2cap_send_conn_req(chan);
5136 }
5137
5138 return;
5139 }
5140
5141 /* Incoming channel on AMP */
5142 if (__l2cap_no_conn_pending(chan)) {
5143 struct l2cap_conn_rsp rsp;
5144 char buf[128];
5145 rsp.scid = cpu_to_le16(chan->dcid);
5146 rsp.dcid = cpu_to_le16(chan->scid);
5147
5148 if (result == L2CAP_CR_SUCCESS) {
5149 /* Send successful response */
5150 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
5151 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
5152 } else {
5153 /* Send negative response */
5154 rsp.result = cpu_to_le16(L2CAP_CR_NO_MEM);
5155 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
5156 }
5157
5158 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_RSP,
5159 sizeof(rsp), &rsp);
5160
5161 if (result == L2CAP_CR_SUCCESS) {
5162 l2cap_state_change(chan, BT_CONFIG);
5163 set_bit(CONF_REQ_SENT, &chan->conf_state);
5164 l2cap_send_cmd(chan->conn, l2cap_get_ident(chan->conn),
5165 L2CAP_CONF_REQ,
5166 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
5167 chan->num_conf_req++;
5168 }
5169 }
5170 }
5171
l2cap_do_move_initiate(struct l2cap_chan * chan,u8 local_amp_id,u8 remote_amp_id)5172 static void l2cap_do_move_initiate(struct l2cap_chan *chan, u8 local_amp_id,
5173 u8 remote_amp_id)
5174 {
5175 l2cap_move_setup(chan);
5176 chan->move_id = local_amp_id;
5177 chan->move_state = L2CAP_MOVE_WAIT_RSP;
5178
5179 l2cap_send_move_chan_req(chan, remote_amp_id);
5180 }
5181
l2cap_do_move_respond(struct l2cap_chan * chan,int result)5182 static void l2cap_do_move_respond(struct l2cap_chan *chan, int result)
5183 {
5184 struct hci_chan *hchan = NULL;
5185
5186 /* Placeholder - get hci_chan for logical link */
5187
5188 if (hchan) {
5189 if (hchan->state == BT_CONNECTED) {
5190 /* Logical link is ready to go */
5191 chan->hs_hcon = hchan->conn;
5192 chan->hs_hcon->l2cap_data = chan->conn;
5193 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
5194 l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS);
5195
5196 l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
5197 } else {
5198 /* Wait for logical link to be ready */
5199 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
5200 }
5201 } else {
5202 /* Logical link not available */
5203 l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_ALLOWED);
5204 }
5205 }
5206
l2cap_do_move_cancel(struct l2cap_chan * chan,int result)5207 static void l2cap_do_move_cancel(struct l2cap_chan *chan, int result)
5208 {
5209 if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) {
5210 u8 rsp_result;
5211 if (result == -EINVAL)
5212 rsp_result = L2CAP_MR_BAD_ID;
5213 else
5214 rsp_result = L2CAP_MR_NOT_ALLOWED;
5215
5216 l2cap_send_move_chan_rsp(chan, rsp_result);
5217 }
5218
5219 chan->move_role = L2CAP_MOVE_ROLE_NONE;
5220 chan->move_state = L2CAP_MOVE_STABLE;
5221
5222 /* Restart data transmission */
5223 l2cap_ertm_send(chan);
5224 }
5225
5226 /* Invoke with locked chan */
__l2cap_physical_cfm(struct l2cap_chan * chan,int result)5227 void __l2cap_physical_cfm(struct l2cap_chan *chan, int result)
5228 {
5229 u8 local_amp_id = chan->local_amp_id;
5230 u8 remote_amp_id = chan->remote_amp_id;
5231
5232 BT_DBG("chan %p, result %d, local_amp_id %d, remote_amp_id %d",
5233 chan, result, local_amp_id, remote_amp_id);
5234
5235 if (chan->state == BT_DISCONN || chan->state == BT_CLOSED)
5236 return;
5237
5238 if (chan->state != BT_CONNECTED) {
5239 l2cap_do_create(chan, result, local_amp_id, remote_amp_id);
5240 } else if (result != L2CAP_MR_SUCCESS) {
5241 l2cap_do_move_cancel(chan, result);
5242 } else {
5243 switch (chan->move_role) {
5244 case L2CAP_MOVE_ROLE_INITIATOR:
5245 l2cap_do_move_initiate(chan, local_amp_id,
5246 remote_amp_id);
5247 break;
5248 case L2CAP_MOVE_ROLE_RESPONDER:
5249 l2cap_do_move_respond(chan, result);
5250 break;
5251 default:
5252 l2cap_do_move_cancel(chan, result);
5253 break;
5254 }
5255 }
5256 }
5257
l2cap_move_channel_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,void * data)5258 static inline int l2cap_move_channel_req(struct l2cap_conn *conn,
5259 struct l2cap_cmd_hdr *cmd,
5260 u16 cmd_len, void *data)
5261 {
5262 struct l2cap_move_chan_req *req = data;
5263 struct l2cap_move_chan_rsp rsp;
5264 struct l2cap_chan *chan;
5265 u16 icid = 0;
5266 u16 result = L2CAP_MR_NOT_ALLOWED;
5267
5268 if (cmd_len != sizeof(*req))
5269 return -EPROTO;
5270
5271 icid = le16_to_cpu(req->icid);
5272
5273 BT_DBG("icid 0x%4.4x, dest_amp_id %d", icid, req->dest_amp_id);
5274
5275 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
5276 return -EINVAL;
5277
5278 chan = l2cap_get_chan_by_dcid(conn, icid);
5279 if (!chan) {
5280 rsp.icid = cpu_to_le16(icid);
5281 rsp.result = cpu_to_le16(L2CAP_MR_NOT_ALLOWED);
5282 l2cap_send_cmd(conn, cmd->ident, L2CAP_MOVE_CHAN_RSP,
5283 sizeof(rsp), &rsp);
5284 return 0;
5285 }
5286
5287 chan->ident = cmd->ident;
5288
5289 if (chan->scid < L2CAP_CID_DYN_START ||
5290 chan->chan_policy == BT_CHANNEL_POLICY_BREDR_ONLY ||
5291 (chan->mode != L2CAP_MODE_ERTM &&
5292 chan->mode != L2CAP_MODE_STREAMING)) {
5293 result = L2CAP_MR_NOT_ALLOWED;
5294 goto send_move_response;
5295 }
5296
5297 if (chan->local_amp_id == req->dest_amp_id) {
5298 result = L2CAP_MR_SAME_ID;
5299 goto send_move_response;
5300 }
5301
5302 if (req->dest_amp_id != AMP_ID_BREDR) {
5303 struct hci_dev *hdev;
5304 hdev = hci_dev_get(req->dest_amp_id);
5305 if (!hdev || hdev->dev_type != HCI_AMP ||
5306 !test_bit(HCI_UP, &hdev->flags)) {
5307 if (hdev)
5308 hci_dev_put(hdev);
5309
5310 result = L2CAP_MR_BAD_ID;
5311 goto send_move_response;
5312 }
5313 hci_dev_put(hdev);
5314 }
5315
5316 /* Detect a move collision. Only send a collision response
5317 * if this side has "lost", otherwise proceed with the move.
5318 * The winner has the larger bd_addr.
5319 */
5320 if ((__chan_is_moving(chan) ||
5321 chan->move_role != L2CAP_MOVE_ROLE_NONE) &&
5322 bacmp(&conn->hcon->src, &conn->hcon->dst) > 0) {
5323 result = L2CAP_MR_COLLISION;
5324 goto send_move_response;
5325 }
5326
5327 chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
5328 l2cap_move_setup(chan);
5329 chan->move_id = req->dest_amp_id;
5330
5331 if (req->dest_amp_id == AMP_ID_BREDR) {
5332 /* Moving to BR/EDR */
5333 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5334 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
5335 result = L2CAP_MR_PEND;
5336 } else {
5337 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
5338 result = L2CAP_MR_SUCCESS;
5339 }
5340 } else {
5341 chan->move_state = L2CAP_MOVE_WAIT_PREPARE;
5342 /* Placeholder - uncomment when amp functions are available */
5343 /*amp_accept_physical(chan, req->dest_amp_id);*/
5344 result = L2CAP_MR_PEND;
5345 }
5346
5347 send_move_response:
5348 l2cap_send_move_chan_rsp(chan, result);
5349
5350 l2cap_chan_unlock(chan);
5351 l2cap_chan_put(chan);
5352
5353 return 0;
5354 }
5355
l2cap_move_continue(struct l2cap_conn * conn,u16 icid,u16 result)5356 static void l2cap_move_continue(struct l2cap_conn *conn, u16 icid, u16 result)
5357 {
5358 struct l2cap_chan *chan;
5359 struct hci_chan *hchan = NULL;
5360
5361 chan = l2cap_get_chan_by_scid(conn, icid);
5362 if (!chan) {
5363 l2cap_send_move_chan_cfm_icid(conn, icid);
5364 return;
5365 }
5366
5367 __clear_chan_timer(chan);
5368 if (result == L2CAP_MR_PEND)
5369 __set_chan_timer(chan, L2CAP_MOVE_ERTX_TIMEOUT);
5370
5371 switch (chan->move_state) {
5372 case L2CAP_MOVE_WAIT_LOGICAL_COMP:
5373 /* Move confirm will be sent when logical link
5374 * is complete.
5375 */
5376 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
5377 break;
5378 case L2CAP_MOVE_WAIT_RSP_SUCCESS:
5379 if (result == L2CAP_MR_PEND) {
5380 break;
5381 } else if (test_bit(CONN_LOCAL_BUSY,
5382 &chan->conn_state)) {
5383 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
5384 } else {
5385 /* Logical link is up or moving to BR/EDR,
5386 * proceed with move
5387 */
5388 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
5389 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
5390 }
5391 break;
5392 case L2CAP_MOVE_WAIT_RSP:
5393 /* Moving to AMP */
5394 if (result == L2CAP_MR_SUCCESS) {
5395 /* Remote is ready, send confirm immediately
5396 * after logical link is ready
5397 */
5398 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
5399 } else {
5400 /* Both logical link and move success
5401 * are required to confirm
5402 */
5403 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_COMP;
5404 }
5405
5406 /* Placeholder - get hci_chan for logical link */
5407 if (!hchan) {
5408 /* Logical link not available */
5409 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5410 break;
5411 }
5412
5413 /* If the logical link is not yet connected, do not
5414 * send confirmation.
5415 */
5416 if (hchan->state != BT_CONNECTED)
5417 break;
5418
5419 /* Logical link is already ready to go */
5420
5421 chan->hs_hcon = hchan->conn;
5422 chan->hs_hcon->l2cap_data = chan->conn;
5423
5424 if (result == L2CAP_MR_SUCCESS) {
5425 /* Can confirm now */
5426 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
5427 } else {
5428 /* Now only need move success
5429 * to confirm
5430 */
5431 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
5432 }
5433
5434 l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
5435 break;
5436 default:
5437 /* Any other amp move state means the move failed. */
5438 chan->move_id = chan->local_amp_id;
5439 l2cap_move_done(chan);
5440 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5441 }
5442
5443 l2cap_chan_unlock(chan);
5444 l2cap_chan_put(chan);
5445 }
5446
l2cap_move_fail(struct l2cap_conn * conn,u8 ident,u16 icid,u16 result)5447 static void l2cap_move_fail(struct l2cap_conn *conn, u8 ident, u16 icid,
5448 u16 result)
5449 {
5450 struct l2cap_chan *chan;
5451
5452 chan = l2cap_get_chan_by_ident(conn, ident);
5453 if (!chan) {
5454 /* Could not locate channel, icid is best guess */
5455 l2cap_send_move_chan_cfm_icid(conn, icid);
5456 return;
5457 }
5458
5459 __clear_chan_timer(chan);
5460
5461 if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
5462 if (result == L2CAP_MR_COLLISION) {
5463 chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
5464 } else {
5465 /* Cleanup - cancel move */
5466 chan->move_id = chan->local_amp_id;
5467 l2cap_move_done(chan);
5468 }
5469 }
5470
5471 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5472
5473 l2cap_chan_unlock(chan);
5474 l2cap_chan_put(chan);
5475 }
5476
l2cap_move_channel_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,void * data)5477 static int l2cap_move_channel_rsp(struct l2cap_conn *conn,
5478 struct l2cap_cmd_hdr *cmd,
5479 u16 cmd_len, void *data)
5480 {
5481 struct l2cap_move_chan_rsp *rsp = data;
5482 u16 icid, result;
5483
5484 if (cmd_len != sizeof(*rsp))
5485 return -EPROTO;
5486
5487 icid = le16_to_cpu(rsp->icid);
5488 result = le16_to_cpu(rsp->result);
5489
5490 BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
5491
5492 if (result == L2CAP_MR_SUCCESS || result == L2CAP_MR_PEND)
5493 l2cap_move_continue(conn, icid, result);
5494 else
5495 l2cap_move_fail(conn, cmd->ident, icid, result);
5496
5497 return 0;
5498 }
5499
l2cap_move_channel_confirm(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,void * data)5500 static int l2cap_move_channel_confirm(struct l2cap_conn *conn,
5501 struct l2cap_cmd_hdr *cmd,
5502 u16 cmd_len, void *data)
5503 {
5504 struct l2cap_move_chan_cfm *cfm = data;
5505 struct l2cap_chan *chan;
5506 u16 icid, result;
5507
5508 if (cmd_len != sizeof(*cfm))
5509 return -EPROTO;
5510
5511 icid = le16_to_cpu(cfm->icid);
5512 result = le16_to_cpu(cfm->result);
5513
5514 BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
5515
5516 chan = l2cap_get_chan_by_dcid(conn, icid);
5517 if (!chan) {
5518 /* Spec requires a response even if the icid was not found */
5519 l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
5520 return 0;
5521 }
5522
5523 if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM) {
5524 if (result == L2CAP_MC_CONFIRMED) {
5525 chan->local_amp_id = chan->move_id;
5526 if (chan->local_amp_id == AMP_ID_BREDR)
5527 __release_logical_link(chan);
5528 } else {
5529 chan->move_id = chan->local_amp_id;
5530 }
5531
5532 l2cap_move_done(chan);
5533 }
5534
5535 l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
5536
5537 l2cap_chan_unlock(chan);
5538 l2cap_chan_put(chan);
5539
5540 return 0;
5541 }
5542
l2cap_move_channel_confirm_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,void * data)5543 static inline int l2cap_move_channel_confirm_rsp(struct l2cap_conn *conn,
5544 struct l2cap_cmd_hdr *cmd,
5545 u16 cmd_len, void *data)
5546 {
5547 struct l2cap_move_chan_cfm_rsp *rsp = data;
5548 struct l2cap_chan *chan;
5549 u16 icid;
5550
5551 if (cmd_len != sizeof(*rsp))
5552 return -EPROTO;
5553
5554 icid = le16_to_cpu(rsp->icid);
5555
5556 BT_DBG("icid 0x%4.4x", icid);
5557
5558 chan = l2cap_get_chan_by_scid(conn, icid);
5559 if (!chan)
5560 return 0;
5561
5562 __clear_chan_timer(chan);
5563
5564 if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM_RSP) {
5565 chan->local_amp_id = chan->move_id;
5566
5567 if (chan->local_amp_id == AMP_ID_BREDR && chan->hs_hchan)
5568 __release_logical_link(chan);
5569
5570 l2cap_move_done(chan);
5571 }
5572
5573 l2cap_chan_unlock(chan);
5574 l2cap_chan_put(chan);
5575
5576 return 0;
5577 }
5578
l2cap_conn_param_update_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5579 static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
5580 struct l2cap_cmd_hdr *cmd,
5581 u16 cmd_len, u8 *data)
5582 {
5583 struct hci_conn *hcon = conn->hcon;
5584 struct l2cap_conn_param_update_req *req;
5585 struct l2cap_conn_param_update_rsp rsp;
5586 u16 min, max, latency, to_multiplier;
5587 int err;
5588
5589 if (hcon->role != HCI_ROLE_MASTER)
5590 return -EINVAL;
5591
5592 if (cmd_len != sizeof(struct l2cap_conn_param_update_req))
5593 return -EPROTO;
5594
5595 req = (struct l2cap_conn_param_update_req *) data;
5596 min = __le16_to_cpu(req->min);
5597 max = __le16_to_cpu(req->max);
5598 latency = __le16_to_cpu(req->latency);
5599 to_multiplier = __le16_to_cpu(req->to_multiplier);
5600
5601 BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x",
5602 min, max, latency, to_multiplier);
5603
5604 memset(&rsp, 0, sizeof(rsp));
5605
5606 err = hci_check_conn_params(min, max, latency, to_multiplier);
5607 if (err)
5608 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
5609 else
5610 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED);
5611
5612 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP,
5613 sizeof(rsp), &rsp);
5614
5615 if (!err) {
5616 u8 store_hint;
5617
5618 store_hint = hci_le_conn_update(hcon, min, max, latency,
5619 to_multiplier);
5620 mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type,
5621 store_hint, min, max, latency,
5622 to_multiplier);
5623
5624 }
5625
5626 return 0;
5627 }
5628
l2cap_le_connect_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5629 static int l2cap_le_connect_rsp(struct l2cap_conn *conn,
5630 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5631 u8 *data)
5632 {
5633 struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data;
5634 struct hci_conn *hcon = conn->hcon;
5635 u16 dcid, mtu, mps, credits, result;
5636 struct l2cap_chan *chan;
5637 int err, sec_level;
5638
5639 if (cmd_len < sizeof(*rsp))
5640 return -EPROTO;
5641
5642 dcid = __le16_to_cpu(rsp->dcid);
5643 mtu = __le16_to_cpu(rsp->mtu);
5644 mps = __le16_to_cpu(rsp->mps);
5645 credits = __le16_to_cpu(rsp->credits);
5646 result = __le16_to_cpu(rsp->result);
5647
5648 if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 ||
5649 dcid < L2CAP_CID_DYN_START ||
5650 dcid > L2CAP_CID_LE_DYN_END))
5651 return -EPROTO;
5652
5653 BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x",
5654 dcid, mtu, mps, credits, result);
5655
5656 mutex_lock(&conn->chan_lock);
5657
5658 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
5659 if (!chan) {
5660 err = -EBADSLT;
5661 goto unlock;
5662 }
5663
5664 err = 0;
5665
5666 l2cap_chan_lock(chan);
5667
5668 switch (result) {
5669 case L2CAP_CR_LE_SUCCESS:
5670 if (__l2cap_get_chan_by_dcid(conn, dcid)) {
5671 err = -EBADSLT;
5672 break;
5673 }
5674
5675 chan->ident = 0;
5676 chan->dcid = dcid;
5677 chan->omtu = mtu;
5678 chan->remote_mps = mps;
5679 chan->tx_credits = credits;
5680 l2cap_chan_ready(chan);
5681 break;
5682
5683 case L2CAP_CR_LE_AUTHENTICATION:
5684 case L2CAP_CR_LE_ENCRYPTION:
5685 /* If we already have MITM protection we can't do
5686 * anything.
5687 */
5688 if (hcon->sec_level > BT_SECURITY_MEDIUM) {
5689 l2cap_chan_del(chan, ECONNREFUSED);
5690 break;
5691 }
5692
5693 sec_level = hcon->sec_level + 1;
5694 if (chan->sec_level < sec_level)
5695 chan->sec_level = sec_level;
5696
5697 /* We'll need to send a new Connect Request */
5698 clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags);
5699
5700 smp_conn_security(hcon, chan->sec_level);
5701 break;
5702
5703 default:
5704 l2cap_chan_del(chan, ECONNREFUSED);
5705 break;
5706 }
5707
5708 l2cap_chan_unlock(chan);
5709
5710 unlock:
5711 mutex_unlock(&conn->chan_lock);
5712
5713 return err;
5714 }
5715
l2cap_bredr_sig_cmd(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5716 static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
5717 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5718 u8 *data)
5719 {
5720 int err = 0;
5721
5722 switch (cmd->code) {
5723 case L2CAP_COMMAND_REJ:
5724 l2cap_command_rej(conn, cmd, cmd_len, data);
5725 break;
5726
5727 case L2CAP_CONN_REQ:
5728 err = l2cap_connect_req(conn, cmd, cmd_len, data);
5729 break;
5730
5731 case L2CAP_CONN_RSP:
5732 case L2CAP_CREATE_CHAN_RSP:
5733 l2cap_connect_create_rsp(conn, cmd, cmd_len, data);
5734 break;
5735
5736 case L2CAP_CONF_REQ:
5737 err = l2cap_config_req(conn, cmd, cmd_len, data);
5738 break;
5739
5740 case L2CAP_CONF_RSP:
5741 l2cap_config_rsp(conn, cmd, cmd_len, data);
5742 break;
5743
5744 case L2CAP_DISCONN_REQ:
5745 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
5746 break;
5747
5748 case L2CAP_DISCONN_RSP:
5749 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
5750 break;
5751
5752 case L2CAP_ECHO_REQ:
5753 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data);
5754 break;
5755
5756 case L2CAP_ECHO_RSP:
5757 break;
5758
5759 case L2CAP_INFO_REQ:
5760 err = l2cap_information_req(conn, cmd, cmd_len, data);
5761 break;
5762
5763 case L2CAP_INFO_RSP:
5764 l2cap_information_rsp(conn, cmd, cmd_len, data);
5765 break;
5766
5767 case L2CAP_CREATE_CHAN_REQ:
5768 err = l2cap_create_channel_req(conn, cmd, cmd_len, data);
5769 break;
5770
5771 case L2CAP_MOVE_CHAN_REQ:
5772 err = l2cap_move_channel_req(conn, cmd, cmd_len, data);
5773 break;
5774
5775 case L2CAP_MOVE_CHAN_RSP:
5776 l2cap_move_channel_rsp(conn, cmd, cmd_len, data);
5777 break;
5778
5779 case L2CAP_MOVE_CHAN_CFM:
5780 err = l2cap_move_channel_confirm(conn, cmd, cmd_len, data);
5781 break;
5782
5783 case L2CAP_MOVE_CHAN_CFM_RSP:
5784 l2cap_move_channel_confirm_rsp(conn, cmd, cmd_len, data);
5785 break;
5786
5787 default:
5788 BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code);
5789 err = -EINVAL;
5790 break;
5791 }
5792
5793 return err;
5794 }
5795
l2cap_le_connect_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5796 static int l2cap_le_connect_req(struct l2cap_conn *conn,
5797 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5798 u8 *data)
5799 {
5800 struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data;
5801 struct l2cap_le_conn_rsp rsp;
5802 struct l2cap_chan *chan, *pchan;
5803 u16 dcid, scid, credits, mtu, mps;
5804 __le16 psm;
5805 u8 result;
5806
5807 if (cmd_len != sizeof(*req))
5808 return -EPROTO;
5809
5810 scid = __le16_to_cpu(req->scid);
5811 mtu = __le16_to_cpu(req->mtu);
5812 mps = __le16_to_cpu(req->mps);
5813 psm = req->psm;
5814 dcid = 0;
5815 credits = 0;
5816
5817 if (mtu < 23 || mps < 23)
5818 return -EPROTO;
5819
5820 BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
5821 scid, mtu, mps);
5822
5823 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
5824 * page 1059:
5825 *
5826 * Valid range: 0x0001-0x00ff
5827 *
5828 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
5829 */
5830 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
5831 result = L2CAP_CR_LE_BAD_PSM;
5832 chan = NULL;
5833 goto response;
5834 }
5835
5836 /* Check if we have socket listening on psm */
5837 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
5838 &conn->hcon->dst, LE_LINK);
5839 if (!pchan) {
5840 result = L2CAP_CR_LE_BAD_PSM;
5841 chan = NULL;
5842 goto response;
5843 }
5844
5845 mutex_lock(&conn->chan_lock);
5846 l2cap_chan_lock(pchan);
5847
5848 if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
5849 SMP_ALLOW_STK)) {
5850 result = L2CAP_CR_LE_AUTHENTICATION;
5851 chan = NULL;
5852 goto response_unlock;
5853 }
5854
5855 /* Check for valid dynamic CID range */
5856 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
5857 result = L2CAP_CR_LE_INVALID_SCID;
5858 chan = NULL;
5859 goto response_unlock;
5860 }
5861
5862 /* Check if we already have channel with that dcid */
5863 if (__l2cap_get_chan_by_dcid(conn, scid)) {
5864 result = L2CAP_CR_LE_SCID_IN_USE;
5865 chan = NULL;
5866 goto response_unlock;
5867 }
5868
5869 chan = pchan->ops->new_connection(pchan);
5870 if (!chan) {
5871 result = L2CAP_CR_LE_NO_MEM;
5872 goto response_unlock;
5873 }
5874
5875 bacpy(&chan->src, &conn->hcon->src);
5876 bacpy(&chan->dst, &conn->hcon->dst);
5877 chan->src_type = bdaddr_src_type(conn->hcon);
5878 chan->dst_type = bdaddr_dst_type(conn->hcon);
5879 chan->psm = psm;
5880 chan->dcid = scid;
5881 chan->omtu = mtu;
5882 chan->remote_mps = mps;
5883
5884 __l2cap_chan_add(conn, chan);
5885
5886 l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits));
5887
5888 dcid = chan->scid;
5889 credits = chan->rx_credits;
5890
5891 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
5892
5893 chan->ident = cmd->ident;
5894
5895 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
5896 l2cap_state_change(chan, BT_CONNECT2);
5897 /* The following result value is actually not defined
5898 * for LE CoC but we use it to let the function know
5899 * that it should bail out after doing its cleanup
5900 * instead of sending a response.
5901 */
5902 result = L2CAP_CR_PEND;
5903 chan->ops->defer(chan);
5904 } else {
5905 l2cap_chan_ready(chan);
5906 result = L2CAP_CR_LE_SUCCESS;
5907 }
5908
5909 response_unlock:
5910 l2cap_chan_unlock(pchan);
5911 mutex_unlock(&conn->chan_lock);
5912 l2cap_chan_put(pchan);
5913
5914 if (result == L2CAP_CR_PEND)
5915 return 0;
5916
5917 response:
5918 if (chan) {
5919 rsp.mtu = cpu_to_le16(chan->imtu);
5920 rsp.mps = cpu_to_le16(chan->mps);
5921 } else {
5922 rsp.mtu = 0;
5923 rsp.mps = 0;
5924 }
5925
5926 rsp.dcid = cpu_to_le16(dcid);
5927 rsp.credits = cpu_to_le16(credits);
5928 rsp.result = cpu_to_le16(result);
5929
5930 l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp);
5931
5932 return 0;
5933 }
5934
l2cap_le_credits(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5935 static inline int l2cap_le_credits(struct l2cap_conn *conn,
5936 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5937 u8 *data)
5938 {
5939 struct l2cap_le_credits *pkt;
5940 struct l2cap_chan *chan;
5941 u16 cid, credits, max_credits;
5942
5943 if (cmd_len != sizeof(*pkt))
5944 return -EPROTO;
5945
5946 pkt = (struct l2cap_le_credits *) data;
5947 cid = __le16_to_cpu(pkt->cid);
5948 credits = __le16_to_cpu(pkt->credits);
5949
5950 BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits);
5951
5952 chan = l2cap_get_chan_by_dcid(conn, cid);
5953 if (!chan)
5954 return -EBADSLT;
5955
5956 max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits;
5957 if (credits > max_credits) {
5958 BT_ERR("LE credits overflow");
5959 l2cap_send_disconn_req(chan, ECONNRESET);
5960
5961 /* Return 0 so that we don't trigger an unnecessary
5962 * command reject packet.
5963 */
5964 goto unlock;
5965 }
5966
5967 chan->tx_credits += credits;
5968
5969 /* Resume sending */
5970 l2cap_le_flowctl_send(chan);
5971
5972 if (chan->tx_credits)
5973 chan->ops->resume(chan);
5974
5975 unlock:
5976 l2cap_chan_unlock(chan);
5977 l2cap_chan_put(chan);
5978
5979 return 0;
5980 }
5981
l2cap_ecred_conn_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)5982 static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
5983 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5984 u8 *data)
5985 {
5986 struct l2cap_ecred_conn_req *req = (void *) data;
5987 struct {
5988 struct l2cap_ecred_conn_rsp rsp;
5989 __le16 dcid[L2CAP_ECRED_MAX_CID];
5990 } __packed pdu;
5991 struct l2cap_chan *chan, *pchan;
5992 u16 mtu, mps;
5993 __le16 psm;
5994 u8 result, len = 0;
5995 int i, num_scid;
5996 bool defer = false;
5997
5998 if (!enable_ecred)
5999 return -EINVAL;
6000
6001 if (cmd_len < sizeof(*req) || (cmd_len - sizeof(*req)) % sizeof(u16)) {
6002 result = L2CAP_CR_LE_INVALID_PARAMS;
6003 goto response;
6004 }
6005
6006 cmd_len -= sizeof(*req);
6007 num_scid = cmd_len / sizeof(u16);
6008
6009 if (num_scid > ARRAY_SIZE(pdu.dcid)) {
6010 result = L2CAP_CR_LE_INVALID_PARAMS;
6011 goto response;
6012 }
6013
6014 mtu = __le16_to_cpu(req->mtu);
6015 mps = __le16_to_cpu(req->mps);
6016
6017 if (mtu < L2CAP_ECRED_MIN_MTU || mps < L2CAP_ECRED_MIN_MPS) {
6018 result = L2CAP_CR_LE_UNACCEPT_PARAMS;
6019 goto response;
6020 }
6021
6022 psm = req->psm;
6023
6024 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
6025 * page 1059:
6026 *
6027 * Valid range: 0x0001-0x00ff
6028 *
6029 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
6030 */
6031 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
6032 result = L2CAP_CR_LE_BAD_PSM;
6033 goto response;
6034 }
6035
6036 BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps);
6037
6038 memset(&pdu, 0, sizeof(pdu));
6039
6040 /* Check if we have socket listening on psm */
6041 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
6042 &conn->hcon->dst, LE_LINK);
6043 if (!pchan) {
6044 result = L2CAP_CR_LE_BAD_PSM;
6045 goto response;
6046 }
6047
6048 mutex_lock(&conn->chan_lock);
6049 l2cap_chan_lock(pchan);
6050
6051 if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
6052 SMP_ALLOW_STK)) {
6053 result = L2CAP_CR_LE_AUTHENTICATION;
6054 goto unlock;
6055 }
6056
6057 result = L2CAP_CR_LE_SUCCESS;
6058
6059 for (i = 0; i < num_scid; i++) {
6060 u16 scid = __le16_to_cpu(req->scid[i]);
6061
6062 BT_DBG("scid[%d] 0x%4.4x", i, scid);
6063
6064 pdu.dcid[i] = 0x0000;
6065 len += sizeof(*pdu.dcid);
6066
6067 /* Check for valid dynamic CID range */
6068 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
6069 result = L2CAP_CR_LE_INVALID_SCID;
6070 continue;
6071 }
6072
6073 /* Check if we already have channel with that dcid */
6074 if (__l2cap_get_chan_by_dcid(conn, scid)) {
6075 result = L2CAP_CR_LE_SCID_IN_USE;
6076 continue;
6077 }
6078
6079 chan = pchan->ops->new_connection(pchan);
6080 if (!chan) {
6081 result = L2CAP_CR_LE_NO_MEM;
6082 continue;
6083 }
6084
6085 bacpy(&chan->src, &conn->hcon->src);
6086 bacpy(&chan->dst, &conn->hcon->dst);
6087 chan->src_type = bdaddr_src_type(conn->hcon);
6088 chan->dst_type = bdaddr_dst_type(conn->hcon);
6089 chan->psm = psm;
6090 chan->dcid = scid;
6091 chan->omtu = mtu;
6092 chan->remote_mps = mps;
6093
6094 __l2cap_chan_add(conn, chan);
6095
6096 l2cap_ecred_init(chan, __le16_to_cpu(req->credits));
6097
6098 /* Init response */
6099 if (!pdu.rsp.credits) {
6100 pdu.rsp.mtu = cpu_to_le16(chan->imtu);
6101 pdu.rsp.mps = cpu_to_le16(chan->mps);
6102 pdu.rsp.credits = cpu_to_le16(chan->rx_credits);
6103 }
6104
6105 pdu.dcid[i] = cpu_to_le16(chan->scid);
6106
6107 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
6108
6109 chan->ident = cmd->ident;
6110 chan->mode = L2CAP_MODE_EXT_FLOWCTL;
6111
6112 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
6113 l2cap_state_change(chan, BT_CONNECT2);
6114 defer = true;
6115 chan->ops->defer(chan);
6116 } else {
6117 l2cap_chan_ready(chan);
6118 }
6119 }
6120
6121 unlock:
6122 l2cap_chan_unlock(pchan);
6123 mutex_unlock(&conn->chan_lock);
6124 l2cap_chan_put(pchan);
6125
6126 response:
6127 pdu.rsp.result = cpu_to_le16(result);
6128
6129 if (defer)
6130 return 0;
6131
6132 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_CONN_RSP,
6133 sizeof(pdu.rsp) + len, &pdu);
6134
6135 return 0;
6136 }
6137
l2cap_ecred_conn_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)6138 static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn,
6139 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
6140 u8 *data)
6141 {
6142 struct l2cap_ecred_conn_rsp *rsp = (void *) data;
6143 struct hci_conn *hcon = conn->hcon;
6144 u16 mtu, mps, credits, result;
6145 struct l2cap_chan *chan, *tmp;
6146 int err = 0, sec_level;
6147 int i = 0;
6148
6149 if (cmd_len < sizeof(*rsp))
6150 return -EPROTO;
6151
6152 mtu = __le16_to_cpu(rsp->mtu);
6153 mps = __le16_to_cpu(rsp->mps);
6154 credits = __le16_to_cpu(rsp->credits);
6155 result = __le16_to_cpu(rsp->result);
6156
6157 BT_DBG("mtu %u mps %u credits %u result 0x%4.4x", mtu, mps, credits,
6158 result);
6159
6160 mutex_lock(&conn->chan_lock);
6161
6162 cmd_len -= sizeof(*rsp);
6163
6164 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
6165 u16 dcid;
6166
6167 if (chan->ident != cmd->ident ||
6168 chan->mode != L2CAP_MODE_EXT_FLOWCTL ||
6169 chan->state == BT_CONNECTED)
6170 continue;
6171
6172 l2cap_chan_lock(chan);
6173
6174 /* Check that there is a dcid for each pending channel */
6175 if (cmd_len < sizeof(dcid)) {
6176 l2cap_chan_del(chan, ECONNREFUSED);
6177 l2cap_chan_unlock(chan);
6178 continue;
6179 }
6180
6181 dcid = __le16_to_cpu(rsp->dcid[i++]);
6182 cmd_len -= sizeof(u16);
6183
6184 BT_DBG("dcid[%d] 0x%4.4x", i, dcid);
6185
6186 /* Check if dcid is already in use */
6187 if (dcid && __l2cap_get_chan_by_dcid(conn, dcid)) {
6188 /* If a device receives a
6189 * L2CAP_CREDIT_BASED_CONNECTION_RSP packet with an
6190 * already-assigned Destination CID, then both the
6191 * original channel and the new channel shall be
6192 * immediately discarded and not used.
6193 */
6194 l2cap_chan_del(chan, ECONNREFUSED);
6195 l2cap_chan_unlock(chan);
6196 chan = __l2cap_get_chan_by_dcid(conn, dcid);
6197 l2cap_chan_lock(chan);
6198 l2cap_chan_del(chan, ECONNRESET);
6199 l2cap_chan_unlock(chan);
6200 continue;
6201 }
6202
6203 switch (result) {
6204 case L2CAP_CR_LE_AUTHENTICATION:
6205 case L2CAP_CR_LE_ENCRYPTION:
6206 /* If we already have MITM protection we can't do
6207 * anything.
6208 */
6209 if (hcon->sec_level > BT_SECURITY_MEDIUM) {
6210 l2cap_chan_del(chan, ECONNREFUSED);
6211 break;
6212 }
6213
6214 sec_level = hcon->sec_level + 1;
6215 if (chan->sec_level < sec_level)
6216 chan->sec_level = sec_level;
6217
6218 /* We'll need to send a new Connect Request */
6219 clear_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags);
6220
6221 smp_conn_security(hcon, chan->sec_level);
6222 break;
6223
6224 case L2CAP_CR_LE_BAD_PSM:
6225 l2cap_chan_del(chan, ECONNREFUSED);
6226 break;
6227
6228 default:
6229 /* If dcid was not set it means channels was refused */
6230 if (!dcid) {
6231 l2cap_chan_del(chan, ECONNREFUSED);
6232 break;
6233 }
6234
6235 chan->ident = 0;
6236 chan->dcid = dcid;
6237 chan->omtu = mtu;
6238 chan->remote_mps = mps;
6239 chan->tx_credits = credits;
6240 l2cap_chan_ready(chan);
6241 break;
6242 }
6243
6244 l2cap_chan_unlock(chan);
6245 }
6246
6247 mutex_unlock(&conn->chan_lock);
6248
6249 return err;
6250 }
6251
l2cap_ecred_reconf_req(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)6252 static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn,
6253 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
6254 u8 *data)
6255 {
6256 struct l2cap_ecred_reconf_req *req = (void *) data;
6257 struct l2cap_ecred_reconf_rsp rsp;
6258 u16 mtu, mps, result;
6259 struct l2cap_chan *chan;
6260 int i, num_scid;
6261
6262 if (!enable_ecred)
6263 return -EINVAL;
6264
6265 if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) {
6266 result = L2CAP_CR_LE_INVALID_PARAMS;
6267 goto respond;
6268 }
6269
6270 mtu = __le16_to_cpu(req->mtu);
6271 mps = __le16_to_cpu(req->mps);
6272
6273 BT_DBG("mtu %u mps %u", mtu, mps);
6274
6275 if (mtu < L2CAP_ECRED_MIN_MTU) {
6276 result = L2CAP_RECONF_INVALID_MTU;
6277 goto respond;
6278 }
6279
6280 if (mps < L2CAP_ECRED_MIN_MPS) {
6281 result = L2CAP_RECONF_INVALID_MPS;
6282 goto respond;
6283 }
6284
6285 cmd_len -= sizeof(*req);
6286 num_scid = cmd_len / sizeof(u16);
6287 result = L2CAP_RECONF_SUCCESS;
6288
6289 for (i = 0; i < num_scid; i++) {
6290 u16 scid;
6291
6292 scid = __le16_to_cpu(req->scid[i]);
6293 if (!scid)
6294 return -EPROTO;
6295
6296 chan = __l2cap_get_chan_by_dcid(conn, scid);
6297 if (!chan)
6298 continue;
6299
6300 /* If the MTU value is decreased for any of the included
6301 * channels, then the receiver shall disconnect all
6302 * included channels.
6303 */
6304 if (chan->omtu > mtu) {
6305 BT_ERR("chan %p decreased MTU %u -> %u", chan,
6306 chan->omtu, mtu);
6307 result = L2CAP_RECONF_INVALID_MTU;
6308 }
6309
6310 chan->omtu = mtu;
6311 chan->remote_mps = mps;
6312 }
6313
6314 respond:
6315 rsp.result = cpu_to_le16(result);
6316
6317 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_RECONF_RSP, sizeof(rsp),
6318 &rsp);
6319
6320 return 0;
6321 }
6322
l2cap_ecred_reconf_rsp(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)6323 static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn,
6324 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
6325 u8 *data)
6326 {
6327 struct l2cap_chan *chan, *tmp;
6328 struct l2cap_ecred_conn_rsp *rsp = (void *) data;
6329 u16 result;
6330
6331 if (cmd_len < sizeof(*rsp))
6332 return -EPROTO;
6333
6334 result = __le16_to_cpu(rsp->result);
6335
6336 BT_DBG("result 0x%4.4x", rsp->result);
6337
6338 if (!result)
6339 return 0;
6340
6341 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
6342 if (chan->ident != cmd->ident)
6343 continue;
6344
6345 l2cap_chan_del(chan, ECONNRESET);
6346 }
6347
6348 return 0;
6349 }
6350
l2cap_le_command_rej(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)6351 static inline int l2cap_le_command_rej(struct l2cap_conn *conn,
6352 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
6353 u8 *data)
6354 {
6355 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
6356 struct l2cap_chan *chan;
6357
6358 if (cmd_len < sizeof(*rej))
6359 return -EPROTO;
6360
6361 mutex_lock(&conn->chan_lock);
6362
6363 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
6364 if (!chan)
6365 goto done;
6366
6367 chan = l2cap_chan_hold_unless_zero(chan);
6368 if (!chan)
6369 goto done;
6370
6371 l2cap_chan_lock(chan);
6372 l2cap_chan_del(chan, ECONNREFUSED);
6373 l2cap_chan_unlock(chan);
6374 l2cap_chan_put(chan);
6375
6376 done:
6377 mutex_unlock(&conn->chan_lock);
6378 return 0;
6379 }
6380
l2cap_le_sig_cmd(struct l2cap_conn * conn,struct l2cap_cmd_hdr * cmd,u16 cmd_len,u8 * data)6381 static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
6382 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
6383 u8 *data)
6384 {
6385 int err = 0;
6386
6387 switch (cmd->code) {
6388 case L2CAP_COMMAND_REJ:
6389 l2cap_le_command_rej(conn, cmd, cmd_len, data);
6390 break;
6391
6392 case L2CAP_CONN_PARAM_UPDATE_REQ:
6393 err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data);
6394 break;
6395
6396 case L2CAP_CONN_PARAM_UPDATE_RSP:
6397 break;
6398
6399 case L2CAP_LE_CONN_RSP:
6400 l2cap_le_connect_rsp(conn, cmd, cmd_len, data);
6401 break;
6402
6403 case L2CAP_LE_CONN_REQ:
6404 err = l2cap_le_connect_req(conn, cmd, cmd_len, data);
6405 break;
6406
6407 case L2CAP_LE_CREDITS:
6408 err = l2cap_le_credits(conn, cmd, cmd_len, data);
6409 break;
6410
6411 case L2CAP_ECRED_CONN_REQ:
6412 err = l2cap_ecred_conn_req(conn, cmd, cmd_len, data);
6413 break;
6414
6415 case L2CAP_ECRED_CONN_RSP:
6416 err = l2cap_ecred_conn_rsp(conn, cmd, cmd_len, data);
6417 break;
6418
6419 case L2CAP_ECRED_RECONF_REQ:
6420 err = l2cap_ecred_reconf_req(conn, cmd, cmd_len, data);
6421 break;
6422
6423 case L2CAP_ECRED_RECONF_RSP:
6424 err = l2cap_ecred_reconf_rsp(conn, cmd, cmd_len, data);
6425 break;
6426
6427 case L2CAP_DISCONN_REQ:
6428 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
6429 break;
6430
6431 case L2CAP_DISCONN_RSP:
6432 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
6433 break;
6434
6435 default:
6436 BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code);
6437 err = -EINVAL;
6438 break;
6439 }
6440
6441 return err;
6442 }
6443
l2cap_le_sig_channel(struct l2cap_conn * conn,struct sk_buff * skb)6444 static inline void l2cap_le_sig_channel(struct l2cap_conn *conn,
6445 struct sk_buff *skb)
6446 {
6447 struct hci_conn *hcon = conn->hcon;
6448 struct l2cap_cmd_hdr *cmd;
6449 u16 len;
6450 int err;
6451
6452 if (hcon->type != LE_LINK)
6453 goto drop;
6454
6455 if (skb->len < L2CAP_CMD_HDR_SIZE)
6456 goto drop;
6457
6458 cmd = (void *) skb->data;
6459 skb_pull(skb, L2CAP_CMD_HDR_SIZE);
6460
6461 len = le16_to_cpu(cmd->len);
6462
6463 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident);
6464
6465 if (len != skb->len || !cmd->ident) {
6466 BT_DBG("corrupted command");
6467 goto drop;
6468 }
6469
6470 err = l2cap_le_sig_cmd(conn, cmd, len, skb->data);
6471 if (err) {
6472 struct l2cap_cmd_rej_unk rej;
6473
6474 BT_ERR("Wrong link type (%d)", err);
6475
6476 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
6477 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ,
6478 sizeof(rej), &rej);
6479 }
6480
6481 drop:
6482 kfree_skb(skb);
6483 }
6484
l2cap_sig_send_rej(struct l2cap_conn * conn,u16 ident)6485 static inline void l2cap_sig_send_rej(struct l2cap_conn *conn, u16 ident)
6486 {
6487 struct l2cap_cmd_rej_unk rej;
6488
6489 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
6490 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
6491 }
6492
l2cap_sig_channel(struct l2cap_conn * conn,struct sk_buff * skb)6493 static inline void l2cap_sig_channel(struct l2cap_conn *conn,
6494 struct sk_buff *skb)
6495 {
6496 struct hci_conn *hcon = conn->hcon;
6497 struct l2cap_cmd_hdr *cmd;
6498 int err;
6499
6500 l2cap_raw_recv(conn, skb);
6501
6502 if (hcon->type != ACL_LINK)
6503 goto drop;
6504
6505 while (skb->len >= L2CAP_CMD_HDR_SIZE) {
6506 u16 len;
6507
6508 cmd = (void *) skb->data;
6509 skb_pull(skb, L2CAP_CMD_HDR_SIZE);
6510
6511 len = le16_to_cpu(cmd->len);
6512
6513 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len,
6514 cmd->ident);
6515
6516 if (len > skb->len || !cmd->ident) {
6517 BT_DBG("corrupted command");
6518 l2cap_sig_send_rej(conn, cmd->ident);
6519 skb_pull(skb, len > skb->len ? skb->len : len);
6520 continue;
6521 }
6522
6523 err = l2cap_bredr_sig_cmd(conn, cmd, len, skb->data);
6524 if (err) {
6525 BT_ERR("Wrong link type (%d)", err);
6526 l2cap_sig_send_rej(conn, cmd->ident);
6527 }
6528
6529 skb_pull(skb, len);
6530 }
6531
6532 if (skb->len > 0) {
6533 BT_DBG("corrupted command");
6534 l2cap_sig_send_rej(conn, 0);
6535 }
6536
6537 drop:
6538 kfree_skb(skb);
6539 }
6540
l2cap_check_fcs(struct l2cap_chan * chan,struct sk_buff * skb)6541 static int l2cap_check_fcs(struct l2cap_chan *chan, struct sk_buff *skb)
6542 {
6543 u16 our_fcs, rcv_fcs;
6544 int hdr_size;
6545
6546 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
6547 hdr_size = L2CAP_EXT_HDR_SIZE;
6548 else
6549 hdr_size = L2CAP_ENH_HDR_SIZE;
6550
6551 if (chan->fcs == L2CAP_FCS_CRC16) {
6552 skb_trim(skb, skb->len - L2CAP_FCS_SIZE);
6553 rcv_fcs = get_unaligned_le16(skb->data + skb->len);
6554 our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size);
6555
6556 if (our_fcs != rcv_fcs)
6557 return -EBADMSG;
6558 }
6559 return 0;
6560 }
6561
l2cap_send_i_or_rr_or_rnr(struct l2cap_chan * chan)6562 static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan)
6563 {
6564 struct l2cap_ctrl control;
6565
6566 BT_DBG("chan %p", chan);
6567
6568 memset(&control, 0, sizeof(control));
6569 control.sframe = 1;
6570 control.final = 1;
6571 control.reqseq = chan->buffer_seq;
6572 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6573
6574 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6575 control.super = L2CAP_SUPER_RNR;
6576 l2cap_send_sframe(chan, &control);
6577 }
6578
6579 if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) &&
6580 chan->unacked_frames > 0)
6581 __set_retrans_timer(chan);
6582
6583 /* Send pending iframes */
6584 l2cap_ertm_send(chan);
6585
6586 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
6587 test_bit(CONN_SEND_FBIT, &chan->conn_state)) {
6588 /* F-bit wasn't sent in an s-frame or i-frame yet, so
6589 * send it now.
6590 */
6591 control.super = L2CAP_SUPER_RR;
6592 l2cap_send_sframe(chan, &control);
6593 }
6594 }
6595
append_skb_frag(struct sk_buff * skb,struct sk_buff * new_frag,struct sk_buff ** last_frag)6596 static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag,
6597 struct sk_buff **last_frag)
6598 {
6599 /* skb->len reflects data in skb as well as all fragments
6600 * skb->data_len reflects only data in fragments
6601 */
6602 if (!skb_has_frag_list(skb))
6603 skb_shinfo(skb)->frag_list = new_frag;
6604
6605 new_frag->next = NULL;
6606
6607 (*last_frag)->next = new_frag;
6608 *last_frag = new_frag;
6609
6610 skb->len += new_frag->len;
6611 skb->data_len += new_frag->len;
6612 skb->truesize += new_frag->truesize;
6613 }
6614
l2cap_reassemble_sdu(struct l2cap_chan * chan,struct sk_buff * skb,struct l2cap_ctrl * control)6615 static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb,
6616 struct l2cap_ctrl *control)
6617 {
6618 int err = -EINVAL;
6619
6620 switch (control->sar) {
6621 case L2CAP_SAR_UNSEGMENTED:
6622 if (chan->sdu)
6623 break;
6624
6625 err = chan->ops->recv(chan, skb);
6626 break;
6627
6628 case L2CAP_SAR_START:
6629 if (chan->sdu)
6630 break;
6631
6632 if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE))
6633 break;
6634
6635 chan->sdu_len = get_unaligned_le16(skb->data);
6636 skb_pull(skb, L2CAP_SDULEN_SIZE);
6637
6638 if (chan->sdu_len > chan->imtu) {
6639 err = -EMSGSIZE;
6640 break;
6641 }
6642
6643 if (skb->len >= chan->sdu_len)
6644 break;
6645
6646 chan->sdu = skb;
6647 chan->sdu_last_frag = skb;
6648
6649 skb = NULL;
6650 err = 0;
6651 break;
6652
6653 case L2CAP_SAR_CONTINUE:
6654 if (!chan->sdu)
6655 break;
6656
6657 append_skb_frag(chan->sdu, skb,
6658 &chan->sdu_last_frag);
6659 skb = NULL;
6660
6661 if (chan->sdu->len >= chan->sdu_len)
6662 break;
6663
6664 err = 0;
6665 break;
6666
6667 case L2CAP_SAR_END:
6668 if (!chan->sdu)
6669 break;
6670
6671 append_skb_frag(chan->sdu, skb,
6672 &chan->sdu_last_frag);
6673 skb = NULL;
6674
6675 if (chan->sdu->len != chan->sdu_len)
6676 break;
6677
6678 err = chan->ops->recv(chan, chan->sdu);
6679
6680 if (!err) {
6681 /* Reassembly complete */
6682 chan->sdu = NULL;
6683 chan->sdu_last_frag = NULL;
6684 chan->sdu_len = 0;
6685 }
6686 break;
6687 }
6688
6689 if (err) {
6690 kfree_skb(skb);
6691 kfree_skb(chan->sdu);
6692 chan->sdu = NULL;
6693 chan->sdu_last_frag = NULL;
6694 chan->sdu_len = 0;
6695 }
6696
6697 return err;
6698 }
6699
l2cap_resegment(struct l2cap_chan * chan)6700 static int l2cap_resegment(struct l2cap_chan *chan)
6701 {
6702 /* Placeholder */
6703 return 0;
6704 }
6705
l2cap_chan_busy(struct l2cap_chan * chan,int busy)6706 void l2cap_chan_busy(struct l2cap_chan *chan, int busy)
6707 {
6708 u8 event;
6709
6710 if (chan->mode != L2CAP_MODE_ERTM)
6711 return;
6712
6713 event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR;
6714 l2cap_tx(chan, NULL, NULL, event);
6715 }
6716
l2cap_rx_queued_iframes(struct l2cap_chan * chan)6717 static int l2cap_rx_queued_iframes(struct l2cap_chan *chan)
6718 {
6719 int err = 0;
6720 /* Pass sequential frames to l2cap_reassemble_sdu()
6721 * until a gap is encountered.
6722 */
6723
6724 BT_DBG("chan %p", chan);
6725
6726 while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6727 struct sk_buff *skb;
6728 BT_DBG("Searching for skb with txseq %d (queue len %d)",
6729 chan->buffer_seq, skb_queue_len(&chan->srej_q));
6730
6731 skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq);
6732
6733 if (!skb)
6734 break;
6735
6736 skb_unlink(skb, &chan->srej_q);
6737 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
6738 err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap);
6739 if (err)
6740 break;
6741 }
6742
6743 if (skb_queue_empty(&chan->srej_q)) {
6744 chan->rx_state = L2CAP_RX_STATE_RECV;
6745 l2cap_send_ack(chan);
6746 }
6747
6748 return err;
6749 }
6750
l2cap_handle_srej(struct l2cap_chan * chan,struct l2cap_ctrl * control)6751 static void l2cap_handle_srej(struct l2cap_chan *chan,
6752 struct l2cap_ctrl *control)
6753 {
6754 struct sk_buff *skb;
6755
6756 BT_DBG("chan %p, control %p", chan, control);
6757
6758 if (control->reqseq == chan->next_tx_seq) {
6759 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
6760 l2cap_send_disconn_req(chan, ECONNRESET);
6761 return;
6762 }
6763
6764 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
6765
6766 if (skb == NULL) {
6767 BT_DBG("Seq %d not available for retransmission",
6768 control->reqseq);
6769 return;
6770 }
6771
6772 if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) {
6773 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
6774 l2cap_send_disconn_req(chan, ECONNRESET);
6775 return;
6776 }
6777
6778 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6779
6780 if (control->poll) {
6781 l2cap_pass_to_tx(chan, control);
6782
6783 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6784 l2cap_retransmit(chan, control);
6785 l2cap_ertm_send(chan);
6786
6787 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
6788 set_bit(CONN_SREJ_ACT, &chan->conn_state);
6789 chan->srej_save_reqseq = control->reqseq;
6790 }
6791 } else {
6792 l2cap_pass_to_tx_fbit(chan, control);
6793
6794 if (control->final) {
6795 if (chan->srej_save_reqseq != control->reqseq ||
6796 !test_and_clear_bit(CONN_SREJ_ACT,
6797 &chan->conn_state))
6798 l2cap_retransmit(chan, control);
6799 } else {
6800 l2cap_retransmit(chan, control);
6801 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
6802 set_bit(CONN_SREJ_ACT, &chan->conn_state);
6803 chan->srej_save_reqseq = control->reqseq;
6804 }
6805 }
6806 }
6807 }
6808
l2cap_handle_rej(struct l2cap_chan * chan,struct l2cap_ctrl * control)6809 static void l2cap_handle_rej(struct l2cap_chan *chan,
6810 struct l2cap_ctrl *control)
6811 {
6812 struct sk_buff *skb;
6813
6814 BT_DBG("chan %p, control %p", chan, control);
6815
6816 if (control->reqseq == chan->next_tx_seq) {
6817 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
6818 l2cap_send_disconn_req(chan, ECONNRESET);
6819 return;
6820 }
6821
6822 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
6823
6824 if (chan->max_tx && skb &&
6825 bt_cb(skb)->l2cap.retries >= chan->max_tx) {
6826 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
6827 l2cap_send_disconn_req(chan, ECONNRESET);
6828 return;
6829 }
6830
6831 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6832
6833 l2cap_pass_to_tx(chan, control);
6834
6835 if (control->final) {
6836 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state))
6837 l2cap_retransmit_all(chan, control);
6838 } else {
6839 l2cap_retransmit_all(chan, control);
6840 l2cap_ertm_send(chan);
6841 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F)
6842 set_bit(CONN_REJ_ACT, &chan->conn_state);
6843 }
6844 }
6845
l2cap_classify_txseq(struct l2cap_chan * chan,u16 txseq)6846 static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq)
6847 {
6848 BT_DBG("chan %p, txseq %d", chan, txseq);
6849
6850 BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq,
6851 chan->expected_tx_seq);
6852
6853 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
6854 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
6855 chan->tx_win) {
6856 /* See notes below regarding "double poll" and
6857 * invalid packets.
6858 */
6859 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
6860 BT_DBG("Invalid/Ignore - after SREJ");
6861 return L2CAP_TXSEQ_INVALID_IGNORE;
6862 } else {
6863 BT_DBG("Invalid - in window after SREJ sent");
6864 return L2CAP_TXSEQ_INVALID;
6865 }
6866 }
6867
6868 if (chan->srej_list.head == txseq) {
6869 BT_DBG("Expected SREJ");
6870 return L2CAP_TXSEQ_EXPECTED_SREJ;
6871 }
6872
6873 if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) {
6874 BT_DBG("Duplicate SREJ - txseq already stored");
6875 return L2CAP_TXSEQ_DUPLICATE_SREJ;
6876 }
6877
6878 if (l2cap_seq_list_contains(&chan->srej_list, txseq)) {
6879 BT_DBG("Unexpected SREJ - not requested");
6880 return L2CAP_TXSEQ_UNEXPECTED_SREJ;
6881 }
6882 }
6883
6884 if (chan->expected_tx_seq == txseq) {
6885 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
6886 chan->tx_win) {
6887 BT_DBG("Invalid - txseq outside tx window");
6888 return L2CAP_TXSEQ_INVALID;
6889 } else {
6890 BT_DBG("Expected");
6891 return L2CAP_TXSEQ_EXPECTED;
6892 }
6893 }
6894
6895 if (__seq_offset(chan, txseq, chan->last_acked_seq) <
6896 __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) {
6897 BT_DBG("Duplicate - expected_tx_seq later than txseq");
6898 return L2CAP_TXSEQ_DUPLICATE;
6899 }
6900
6901 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) {
6902 /* A source of invalid packets is a "double poll" condition,
6903 * where delays cause us to send multiple poll packets. If
6904 * the remote stack receives and processes both polls,
6905 * sequence numbers can wrap around in such a way that a
6906 * resent frame has a sequence number that looks like new data
6907 * with a sequence gap. This would trigger an erroneous SREJ
6908 * request.
6909 *
6910 * Fortunately, this is impossible with a tx window that's
6911 * less than half of the maximum sequence number, which allows
6912 * invalid frames to be safely ignored.
6913 *
6914 * With tx window sizes greater than half of the tx window
6915 * maximum, the frame is invalid and cannot be ignored. This
6916 * causes a disconnect.
6917 */
6918
6919 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
6920 BT_DBG("Invalid/Ignore - txseq outside tx window");
6921 return L2CAP_TXSEQ_INVALID_IGNORE;
6922 } else {
6923 BT_DBG("Invalid - txseq outside tx window");
6924 return L2CAP_TXSEQ_INVALID;
6925 }
6926 } else {
6927 BT_DBG("Unexpected - txseq indicates missing frames");
6928 return L2CAP_TXSEQ_UNEXPECTED;
6929 }
6930 }
6931
l2cap_rx_state_recv(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)6932 static int l2cap_rx_state_recv(struct l2cap_chan *chan,
6933 struct l2cap_ctrl *control,
6934 struct sk_buff *skb, u8 event)
6935 {
6936 struct l2cap_ctrl local_control;
6937 int err = 0;
6938 bool skb_in_use = false;
6939
6940 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6941 event);
6942
6943 switch (event) {
6944 case L2CAP_EV_RECV_IFRAME:
6945 switch (l2cap_classify_txseq(chan, control->txseq)) {
6946 case L2CAP_TXSEQ_EXPECTED:
6947 l2cap_pass_to_tx(chan, control);
6948
6949 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6950 BT_DBG("Busy, discarding expected seq %d",
6951 control->txseq);
6952 break;
6953 }
6954
6955 chan->expected_tx_seq = __next_seq(chan,
6956 control->txseq);
6957
6958 chan->buffer_seq = chan->expected_tx_seq;
6959 skb_in_use = true;
6960
6961 /* l2cap_reassemble_sdu may free skb, hence invalidate
6962 * control, so make a copy in advance to use it after
6963 * l2cap_reassemble_sdu returns and to avoid the race
6964 * condition, for example:
6965 *
6966 * The current thread calls:
6967 * l2cap_reassemble_sdu
6968 * chan->ops->recv == l2cap_sock_recv_cb
6969 * __sock_queue_rcv_skb
6970 * Another thread calls:
6971 * bt_sock_recvmsg
6972 * skb_recv_datagram
6973 * skb_free_datagram
6974 * Then the current thread tries to access control, but
6975 * it was freed by skb_free_datagram.
6976 */
6977 local_control = *control;
6978 err = l2cap_reassemble_sdu(chan, skb, control);
6979 if (err)
6980 break;
6981
6982 if (local_control.final) {
6983 if (!test_and_clear_bit(CONN_REJ_ACT,
6984 &chan->conn_state)) {
6985 local_control.final = 0;
6986 l2cap_retransmit_all(chan, &local_control);
6987 l2cap_ertm_send(chan);
6988 }
6989 }
6990
6991 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
6992 l2cap_send_ack(chan);
6993 break;
6994 case L2CAP_TXSEQ_UNEXPECTED:
6995 l2cap_pass_to_tx(chan, control);
6996
6997 /* Can't issue SREJ frames in the local busy state.
6998 * Drop this frame, it will be seen as missing
6999 * when local busy is exited.
7000 */
7001 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
7002 BT_DBG("Busy, discarding unexpected seq %d",
7003 control->txseq);
7004 break;
7005 }
7006
7007 /* There was a gap in the sequence, so an SREJ
7008 * must be sent for each missing frame. The
7009 * current frame is stored for later use.
7010 */
7011 skb_queue_tail(&chan->srej_q, skb);
7012 skb_in_use = true;
7013 BT_DBG("Queued %p (queue len %d)", skb,
7014 skb_queue_len(&chan->srej_q));
7015
7016 clear_bit(CONN_SREJ_ACT, &chan->conn_state);
7017 l2cap_seq_list_clear(&chan->srej_list);
7018 l2cap_send_srej(chan, control->txseq);
7019
7020 chan->rx_state = L2CAP_RX_STATE_SREJ_SENT;
7021 break;
7022 case L2CAP_TXSEQ_DUPLICATE:
7023 l2cap_pass_to_tx(chan, control);
7024 break;
7025 case L2CAP_TXSEQ_INVALID_IGNORE:
7026 break;
7027 case L2CAP_TXSEQ_INVALID:
7028 default:
7029 l2cap_send_disconn_req(chan, ECONNRESET);
7030 break;
7031 }
7032 break;
7033 case L2CAP_EV_RECV_RR:
7034 l2cap_pass_to_tx(chan, control);
7035 if (control->final) {
7036 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
7037
7038 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state) &&
7039 !__chan_is_moving(chan)) {
7040 control->final = 0;
7041 l2cap_retransmit_all(chan, control);
7042 }
7043
7044 l2cap_ertm_send(chan);
7045 } else if (control->poll) {
7046 l2cap_send_i_or_rr_or_rnr(chan);
7047 } else {
7048 if (test_and_clear_bit(CONN_REMOTE_BUSY,
7049 &chan->conn_state) &&
7050 chan->unacked_frames)
7051 __set_retrans_timer(chan);
7052
7053 l2cap_ertm_send(chan);
7054 }
7055 break;
7056 case L2CAP_EV_RECV_RNR:
7057 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
7058 l2cap_pass_to_tx(chan, control);
7059 if (control && control->poll) {
7060 set_bit(CONN_SEND_FBIT, &chan->conn_state);
7061 l2cap_send_rr_or_rnr(chan, 0);
7062 }
7063 __clear_retrans_timer(chan);
7064 l2cap_seq_list_clear(&chan->retrans_list);
7065 break;
7066 case L2CAP_EV_RECV_REJ:
7067 l2cap_handle_rej(chan, control);
7068 break;
7069 case L2CAP_EV_RECV_SREJ:
7070 l2cap_handle_srej(chan, control);
7071 break;
7072 default:
7073 break;
7074 }
7075
7076 if (skb && !skb_in_use) {
7077 BT_DBG("Freeing %p", skb);
7078 kfree_skb(skb);
7079 }
7080
7081 return err;
7082 }
7083
l2cap_rx_state_srej_sent(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)7084 static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan,
7085 struct l2cap_ctrl *control,
7086 struct sk_buff *skb, u8 event)
7087 {
7088 int err = 0;
7089 u16 txseq = control->txseq;
7090 bool skb_in_use = false;
7091
7092 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
7093 event);
7094
7095 switch (event) {
7096 case L2CAP_EV_RECV_IFRAME:
7097 switch (l2cap_classify_txseq(chan, txseq)) {
7098 case L2CAP_TXSEQ_EXPECTED:
7099 /* Keep frame for reassembly later */
7100 l2cap_pass_to_tx(chan, control);
7101 skb_queue_tail(&chan->srej_q, skb);
7102 skb_in_use = true;
7103 BT_DBG("Queued %p (queue len %d)", skb,
7104 skb_queue_len(&chan->srej_q));
7105
7106 chan->expected_tx_seq = __next_seq(chan, txseq);
7107 break;
7108 case L2CAP_TXSEQ_EXPECTED_SREJ:
7109 l2cap_seq_list_pop(&chan->srej_list);
7110
7111 l2cap_pass_to_tx(chan, control);
7112 skb_queue_tail(&chan->srej_q, skb);
7113 skb_in_use = true;
7114 BT_DBG("Queued %p (queue len %d)", skb,
7115 skb_queue_len(&chan->srej_q));
7116
7117 err = l2cap_rx_queued_iframes(chan);
7118 if (err)
7119 break;
7120
7121 break;
7122 case L2CAP_TXSEQ_UNEXPECTED:
7123 /* Got a frame that can't be reassembled yet.
7124 * Save it for later, and send SREJs to cover
7125 * the missing frames.
7126 */
7127 skb_queue_tail(&chan->srej_q, skb);
7128 skb_in_use = true;
7129 BT_DBG("Queued %p (queue len %d)", skb,
7130 skb_queue_len(&chan->srej_q));
7131
7132 l2cap_pass_to_tx(chan, control);
7133 l2cap_send_srej(chan, control->txseq);
7134 break;
7135 case L2CAP_TXSEQ_UNEXPECTED_SREJ:
7136 /* This frame was requested with an SREJ, but
7137 * some expected retransmitted frames are
7138 * missing. Request retransmission of missing
7139 * SREJ'd frames.
7140 */
7141 skb_queue_tail(&chan->srej_q, skb);
7142 skb_in_use = true;
7143 BT_DBG("Queued %p (queue len %d)", skb,
7144 skb_queue_len(&chan->srej_q));
7145
7146 l2cap_pass_to_tx(chan, control);
7147 l2cap_send_srej_list(chan, control->txseq);
7148 break;
7149 case L2CAP_TXSEQ_DUPLICATE_SREJ:
7150 /* We've already queued this frame. Drop this copy. */
7151 l2cap_pass_to_tx(chan, control);
7152 break;
7153 case L2CAP_TXSEQ_DUPLICATE:
7154 /* Expecting a later sequence number, so this frame
7155 * was already received. Ignore it completely.
7156 */
7157 break;
7158 case L2CAP_TXSEQ_INVALID_IGNORE:
7159 break;
7160 case L2CAP_TXSEQ_INVALID:
7161 default:
7162 l2cap_send_disconn_req(chan, ECONNRESET);
7163 break;
7164 }
7165 break;
7166 case L2CAP_EV_RECV_RR:
7167 l2cap_pass_to_tx(chan, control);
7168 if (control->final) {
7169 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
7170
7171 if (!test_and_clear_bit(CONN_REJ_ACT,
7172 &chan->conn_state)) {
7173 control->final = 0;
7174 l2cap_retransmit_all(chan, control);
7175 }
7176
7177 l2cap_ertm_send(chan);
7178 } else if (control->poll) {
7179 if (test_and_clear_bit(CONN_REMOTE_BUSY,
7180 &chan->conn_state) &&
7181 chan->unacked_frames) {
7182 __set_retrans_timer(chan);
7183 }
7184
7185 set_bit(CONN_SEND_FBIT, &chan->conn_state);
7186 l2cap_send_srej_tail(chan);
7187 } else {
7188 if (test_and_clear_bit(CONN_REMOTE_BUSY,
7189 &chan->conn_state) &&
7190 chan->unacked_frames)
7191 __set_retrans_timer(chan);
7192
7193 l2cap_send_ack(chan);
7194 }
7195 break;
7196 case L2CAP_EV_RECV_RNR:
7197 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
7198 l2cap_pass_to_tx(chan, control);
7199 if (control->poll) {
7200 l2cap_send_srej_tail(chan);
7201 } else {
7202 struct l2cap_ctrl rr_control;
7203 memset(&rr_control, 0, sizeof(rr_control));
7204 rr_control.sframe = 1;
7205 rr_control.super = L2CAP_SUPER_RR;
7206 rr_control.reqseq = chan->buffer_seq;
7207 l2cap_send_sframe(chan, &rr_control);
7208 }
7209
7210 break;
7211 case L2CAP_EV_RECV_REJ:
7212 l2cap_handle_rej(chan, control);
7213 break;
7214 case L2CAP_EV_RECV_SREJ:
7215 l2cap_handle_srej(chan, control);
7216 break;
7217 }
7218
7219 if (skb && !skb_in_use) {
7220 BT_DBG("Freeing %p", skb);
7221 kfree_skb(skb);
7222 }
7223
7224 return err;
7225 }
7226
l2cap_finish_move(struct l2cap_chan * chan)7227 static int l2cap_finish_move(struct l2cap_chan *chan)
7228 {
7229 BT_DBG("chan %p", chan);
7230
7231 chan->rx_state = L2CAP_RX_STATE_RECV;
7232
7233 if (chan->hs_hcon)
7234 chan->conn->mtu = chan->hs_hcon->hdev->block_mtu;
7235 else
7236 chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
7237
7238 return l2cap_resegment(chan);
7239 }
7240
l2cap_rx_state_wait_p(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)7241 static int l2cap_rx_state_wait_p(struct l2cap_chan *chan,
7242 struct l2cap_ctrl *control,
7243 struct sk_buff *skb, u8 event)
7244 {
7245 int err;
7246
7247 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
7248 event);
7249
7250 if (!control->poll)
7251 return -EPROTO;
7252
7253 l2cap_process_reqseq(chan, control->reqseq);
7254
7255 if (!skb_queue_empty(&chan->tx_q))
7256 chan->tx_send_head = skb_peek(&chan->tx_q);
7257 else
7258 chan->tx_send_head = NULL;
7259
7260 /* Rewind next_tx_seq to the point expected
7261 * by the receiver.
7262 */
7263 chan->next_tx_seq = control->reqseq;
7264 chan->unacked_frames = 0;
7265
7266 err = l2cap_finish_move(chan);
7267 if (err)
7268 return err;
7269
7270 set_bit(CONN_SEND_FBIT, &chan->conn_state);
7271 l2cap_send_i_or_rr_or_rnr(chan);
7272
7273 if (event == L2CAP_EV_RECV_IFRAME)
7274 return -EPROTO;
7275
7276 return l2cap_rx_state_recv(chan, control, NULL, event);
7277 }
7278
l2cap_rx_state_wait_f(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)7279 static int l2cap_rx_state_wait_f(struct l2cap_chan *chan,
7280 struct l2cap_ctrl *control,
7281 struct sk_buff *skb, u8 event)
7282 {
7283 int err;
7284
7285 if (!control->final)
7286 return -EPROTO;
7287
7288 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
7289
7290 chan->rx_state = L2CAP_RX_STATE_RECV;
7291 l2cap_process_reqseq(chan, control->reqseq);
7292
7293 if (!skb_queue_empty(&chan->tx_q))
7294 chan->tx_send_head = skb_peek(&chan->tx_q);
7295 else
7296 chan->tx_send_head = NULL;
7297
7298 /* Rewind next_tx_seq to the point expected
7299 * by the receiver.
7300 */
7301 chan->next_tx_seq = control->reqseq;
7302 chan->unacked_frames = 0;
7303
7304 if (chan->hs_hcon)
7305 chan->conn->mtu = chan->hs_hcon->hdev->block_mtu;
7306 else
7307 chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
7308
7309 err = l2cap_resegment(chan);
7310
7311 if (!err)
7312 err = l2cap_rx_state_recv(chan, control, skb, event);
7313
7314 return err;
7315 }
7316
__valid_reqseq(struct l2cap_chan * chan,u16 reqseq)7317 static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq)
7318 {
7319 /* Make sure reqseq is for a packet that has been sent but not acked */
7320 u16 unacked;
7321
7322 unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq);
7323 return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked;
7324 }
7325
l2cap_rx(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb,u8 event)7326 static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
7327 struct sk_buff *skb, u8 event)
7328 {
7329 int err = 0;
7330
7331 BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan,
7332 control, skb, event, chan->rx_state);
7333
7334 if (__valid_reqseq(chan, control->reqseq)) {
7335 switch (chan->rx_state) {
7336 case L2CAP_RX_STATE_RECV:
7337 err = l2cap_rx_state_recv(chan, control, skb, event);
7338 break;
7339 case L2CAP_RX_STATE_SREJ_SENT:
7340 err = l2cap_rx_state_srej_sent(chan, control, skb,
7341 event);
7342 break;
7343 case L2CAP_RX_STATE_WAIT_P:
7344 err = l2cap_rx_state_wait_p(chan, control, skb, event);
7345 break;
7346 case L2CAP_RX_STATE_WAIT_F:
7347 err = l2cap_rx_state_wait_f(chan, control, skb, event);
7348 break;
7349 default:
7350 /* shut it down */
7351 break;
7352 }
7353 } else {
7354 BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d",
7355 control->reqseq, chan->next_tx_seq,
7356 chan->expected_ack_seq);
7357 l2cap_send_disconn_req(chan, ECONNRESET);
7358 }
7359
7360 return err;
7361 }
7362
l2cap_stream_rx(struct l2cap_chan * chan,struct l2cap_ctrl * control,struct sk_buff * skb)7363 static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
7364 struct sk_buff *skb)
7365 {
7366 /* l2cap_reassemble_sdu may free skb, hence invalidate control, so store
7367 * the txseq field in advance to use it after l2cap_reassemble_sdu
7368 * returns and to avoid the race condition, for example:
7369 *
7370 * The current thread calls:
7371 * l2cap_reassemble_sdu
7372 * chan->ops->recv == l2cap_sock_recv_cb
7373 * __sock_queue_rcv_skb
7374 * Another thread calls:
7375 * bt_sock_recvmsg
7376 * skb_recv_datagram
7377 * skb_free_datagram
7378 * Then the current thread tries to access control, but it was freed by
7379 * skb_free_datagram.
7380 */
7381 u16 txseq = control->txseq;
7382
7383 BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb,
7384 chan->rx_state);
7385
7386 if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) {
7387 l2cap_pass_to_tx(chan, control);
7388
7389 BT_DBG("buffer_seq %d->%d", chan->buffer_seq,
7390 __next_seq(chan, chan->buffer_seq));
7391
7392 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
7393
7394 l2cap_reassemble_sdu(chan, skb, control);
7395 } else {
7396 if (chan->sdu) {
7397 kfree_skb(chan->sdu);
7398 chan->sdu = NULL;
7399 }
7400 chan->sdu_last_frag = NULL;
7401 chan->sdu_len = 0;
7402
7403 if (skb) {
7404 BT_DBG("Freeing %p", skb);
7405 kfree_skb(skb);
7406 }
7407 }
7408
7409 chan->last_acked_seq = txseq;
7410 chan->expected_tx_seq = __next_seq(chan, txseq);
7411
7412 return 0;
7413 }
7414
l2cap_data_rcv(struct l2cap_chan * chan,struct sk_buff * skb)7415 static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
7416 {
7417 struct l2cap_ctrl *control = &bt_cb(skb)->l2cap;
7418 u16 len;
7419 u8 event;
7420
7421 __unpack_control(chan, skb);
7422
7423 len = skb->len;
7424
7425 /*
7426 * We can just drop the corrupted I-frame here.
7427 * Receiver will miss it and start proper recovery
7428 * procedures and ask for retransmission.
7429 */
7430 if (l2cap_check_fcs(chan, skb))
7431 goto drop;
7432
7433 if (!control->sframe && control->sar == L2CAP_SAR_START)
7434 len -= L2CAP_SDULEN_SIZE;
7435
7436 if (chan->fcs == L2CAP_FCS_CRC16)
7437 len -= L2CAP_FCS_SIZE;
7438
7439 if (len > chan->mps) {
7440 l2cap_send_disconn_req(chan, ECONNRESET);
7441 goto drop;
7442 }
7443
7444 if (chan->ops->filter) {
7445 if (chan->ops->filter(chan, skb))
7446 goto drop;
7447 }
7448
7449 if (!control->sframe) {
7450 int err;
7451
7452 BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d",
7453 control->sar, control->reqseq, control->final,
7454 control->txseq);
7455
7456 /* Validate F-bit - F=0 always valid, F=1 only
7457 * valid in TX WAIT_F
7458 */
7459 if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F)
7460 goto drop;
7461
7462 if (chan->mode != L2CAP_MODE_STREAMING) {
7463 event = L2CAP_EV_RECV_IFRAME;
7464 err = l2cap_rx(chan, control, skb, event);
7465 } else {
7466 err = l2cap_stream_rx(chan, control, skb);
7467 }
7468
7469 if (err)
7470 l2cap_send_disconn_req(chan, ECONNRESET);
7471 } else {
7472 const u8 rx_func_to_event[4] = {
7473 L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ,
7474 L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ
7475 };
7476
7477 /* Only I-frames are expected in streaming mode */
7478 if (chan->mode == L2CAP_MODE_STREAMING)
7479 goto drop;
7480
7481 BT_DBG("sframe reqseq %d, final %d, poll %d, super %d",
7482 control->reqseq, control->final, control->poll,
7483 control->super);
7484
7485 if (len != 0) {
7486 BT_ERR("Trailing bytes: %d in sframe", len);
7487 l2cap_send_disconn_req(chan, ECONNRESET);
7488 goto drop;
7489 }
7490
7491 /* Validate F and P bits */
7492 if (control->final && (control->poll ||
7493 chan->tx_state != L2CAP_TX_STATE_WAIT_F))
7494 goto drop;
7495
7496 event = rx_func_to_event[control->super];
7497 if (l2cap_rx(chan, control, skb, event))
7498 l2cap_send_disconn_req(chan, ECONNRESET);
7499 }
7500
7501 return 0;
7502
7503 drop:
7504 kfree_skb(skb);
7505 return 0;
7506 }
7507
l2cap_chan_le_send_credits(struct l2cap_chan * chan)7508 static void l2cap_chan_le_send_credits(struct l2cap_chan *chan)
7509 {
7510 struct l2cap_conn *conn = chan->conn;
7511 struct l2cap_le_credits pkt;
7512 u16 return_credits;
7513
7514 return_credits = (chan->imtu / chan->mps) + 1;
7515
7516 if (chan->rx_credits >= return_credits)
7517 return;
7518
7519 return_credits -= chan->rx_credits;
7520
7521 BT_DBG("chan %p returning %u credits to sender", chan, return_credits);
7522
7523 chan->rx_credits += return_credits;
7524
7525 pkt.cid = cpu_to_le16(chan->scid);
7526 pkt.credits = cpu_to_le16(return_credits);
7527
7528 chan->ident = l2cap_get_ident(conn);
7529
7530 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt);
7531 }
7532
l2cap_ecred_recv(struct l2cap_chan * chan,struct sk_buff * skb)7533 static int l2cap_ecred_recv(struct l2cap_chan *chan, struct sk_buff *skb)
7534 {
7535 int err;
7536
7537 BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len);
7538
7539 /* Wait recv to confirm reception before updating the credits */
7540 err = chan->ops->recv(chan, skb);
7541
7542 /* Update credits whenever an SDU is received */
7543 l2cap_chan_le_send_credits(chan);
7544
7545 return err;
7546 }
7547
l2cap_ecred_data_rcv(struct l2cap_chan * chan,struct sk_buff * skb)7548 static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
7549 {
7550 int err;
7551
7552 if (!chan->rx_credits) {
7553 BT_ERR("No credits to receive LE L2CAP data");
7554 l2cap_send_disconn_req(chan, ECONNRESET);
7555 return -ENOBUFS;
7556 }
7557
7558 if (chan->imtu < skb->len) {
7559 BT_ERR("Too big LE L2CAP PDU");
7560 return -ENOBUFS;
7561 }
7562
7563 chan->rx_credits--;
7564 BT_DBG("rx_credits %u -> %u", chan->rx_credits + 1, chan->rx_credits);
7565
7566 /* Update if remote had run out of credits, this should only happens
7567 * if the remote is not using the entire MPS.
7568 */
7569 if (!chan->rx_credits)
7570 l2cap_chan_le_send_credits(chan);
7571
7572 err = 0;
7573
7574 if (!chan->sdu) {
7575 u16 sdu_len;
7576
7577 sdu_len = get_unaligned_le16(skb->data);
7578 skb_pull(skb, L2CAP_SDULEN_SIZE);
7579
7580 BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u",
7581 sdu_len, skb->len, chan->imtu);
7582
7583 if (sdu_len > chan->imtu) {
7584 BT_ERR("Too big LE L2CAP SDU length received");
7585 err = -EMSGSIZE;
7586 goto failed;
7587 }
7588
7589 if (skb->len > sdu_len) {
7590 BT_ERR("Too much LE L2CAP data received");
7591 err = -EINVAL;
7592 goto failed;
7593 }
7594
7595 if (skb->len == sdu_len)
7596 return l2cap_ecred_recv(chan, skb);
7597
7598 chan->sdu = skb;
7599 chan->sdu_len = sdu_len;
7600 chan->sdu_last_frag = skb;
7601
7602 /* Detect if remote is not able to use the selected MPS */
7603 if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) {
7604 u16 mps_len = skb->len + L2CAP_SDULEN_SIZE;
7605
7606 /* Adjust the number of credits */
7607 BT_DBG("chan->mps %u -> %u", chan->mps, mps_len);
7608 chan->mps = mps_len;
7609 l2cap_chan_le_send_credits(chan);
7610 }
7611
7612 return 0;
7613 }
7614
7615 BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u",
7616 chan->sdu->len, skb->len, chan->sdu_len);
7617
7618 if (chan->sdu->len + skb->len > chan->sdu_len) {
7619 BT_ERR("Too much LE L2CAP data received");
7620 err = -EINVAL;
7621 goto failed;
7622 }
7623
7624 append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag);
7625 skb = NULL;
7626
7627 if (chan->sdu->len == chan->sdu_len) {
7628 err = l2cap_ecred_recv(chan, chan->sdu);
7629 if (!err) {
7630 chan->sdu = NULL;
7631 chan->sdu_last_frag = NULL;
7632 chan->sdu_len = 0;
7633 }
7634 }
7635
7636 failed:
7637 if (err) {
7638 kfree_skb(skb);
7639 kfree_skb(chan->sdu);
7640 chan->sdu = NULL;
7641 chan->sdu_last_frag = NULL;
7642 chan->sdu_len = 0;
7643 }
7644
7645 /* We can't return an error here since we took care of the skb
7646 * freeing internally. An error return would cause the caller to
7647 * do a double-free of the skb.
7648 */
7649 return 0;
7650 }
7651
l2cap_data_channel(struct l2cap_conn * conn,u16 cid,struct sk_buff * skb)7652 static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,
7653 struct sk_buff *skb)
7654 {
7655 struct l2cap_chan *chan;
7656
7657 chan = l2cap_get_chan_by_scid(conn, cid);
7658 if (!chan) {
7659 if (cid == L2CAP_CID_A2MP) {
7660 chan = a2mp_channel_create(conn, skb);
7661 if (!chan) {
7662 kfree_skb(skb);
7663 return;
7664 }
7665
7666 l2cap_chan_hold(chan);
7667 l2cap_chan_lock(chan);
7668 } else {
7669 BT_DBG("unknown cid 0x%4.4x", cid);
7670 /* Drop packet and return */
7671 kfree_skb(skb);
7672 return;
7673 }
7674 }
7675
7676 BT_DBG("chan %p, len %d", chan, skb->len);
7677
7678 /* If we receive data on a fixed channel before the info req/rsp
7679 * procedure is done simply assume that the channel is supported
7680 * and mark it as ready.
7681 */
7682 if (chan->chan_type == L2CAP_CHAN_FIXED)
7683 l2cap_chan_ready(chan);
7684
7685 if (chan->state != BT_CONNECTED)
7686 goto drop;
7687
7688 switch (chan->mode) {
7689 case L2CAP_MODE_LE_FLOWCTL:
7690 case L2CAP_MODE_EXT_FLOWCTL:
7691 if (l2cap_ecred_data_rcv(chan, skb) < 0)
7692 goto drop;
7693
7694 goto done;
7695
7696 case L2CAP_MODE_BASIC:
7697 /* If socket recv buffers overflows we drop data here
7698 * which is *bad* because L2CAP has to be reliable.
7699 * But we don't have any other choice. L2CAP doesn't
7700 * provide flow control mechanism. */
7701
7702 if (chan->imtu < skb->len) {
7703 BT_ERR("Dropping L2CAP data: receive buffer overflow");
7704 goto drop;
7705 }
7706
7707 if (!chan->ops->recv(chan, skb))
7708 goto done;
7709 break;
7710
7711 case L2CAP_MODE_ERTM:
7712 case L2CAP_MODE_STREAMING:
7713 l2cap_data_rcv(chan, skb);
7714 goto done;
7715
7716 default:
7717 BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode);
7718 break;
7719 }
7720
7721 drop:
7722 kfree_skb(skb);
7723
7724 done:
7725 l2cap_chan_unlock(chan);
7726 l2cap_chan_put(chan);
7727 }
7728
l2cap_conless_channel(struct l2cap_conn * conn,__le16 psm,struct sk_buff * skb)7729 static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm,
7730 struct sk_buff *skb)
7731 {
7732 struct hci_conn *hcon = conn->hcon;
7733 struct l2cap_chan *chan;
7734
7735 if (hcon->type != ACL_LINK)
7736 goto free_skb;
7737
7738 chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst,
7739 ACL_LINK);
7740 if (!chan)
7741 goto free_skb;
7742
7743 BT_DBG("chan %p, len %d", chan, skb->len);
7744
7745 if (chan->state != BT_BOUND && chan->state != BT_CONNECTED)
7746 goto drop;
7747
7748 if (chan->imtu < skb->len)
7749 goto drop;
7750
7751 /* Store remote BD_ADDR and PSM for msg_name */
7752 bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst);
7753 bt_cb(skb)->l2cap.psm = psm;
7754
7755 if (!chan->ops->recv(chan, skb)) {
7756 l2cap_chan_put(chan);
7757 return;
7758 }
7759
7760 drop:
7761 l2cap_chan_put(chan);
7762 free_skb:
7763 kfree_skb(skb);
7764 }
7765
l2cap_recv_frame(struct l2cap_conn * conn,struct sk_buff * skb)7766 static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
7767 {
7768 struct l2cap_hdr *lh = (void *) skb->data;
7769 struct hci_conn *hcon = conn->hcon;
7770 u16 cid, len;
7771 __le16 psm;
7772
7773 if (hcon->state != BT_CONNECTED) {
7774 BT_DBG("queueing pending rx skb");
7775 skb_queue_tail(&conn->pending_rx, skb);
7776 return;
7777 }
7778
7779 skb_pull(skb, L2CAP_HDR_SIZE);
7780 cid = __le16_to_cpu(lh->cid);
7781 len = __le16_to_cpu(lh->len);
7782
7783 if (len != skb->len) {
7784 kfree_skb(skb);
7785 return;
7786 }
7787
7788 /* Since we can't actively block incoming LE connections we must
7789 * at least ensure that we ignore incoming data from them.
7790 */
7791 if (hcon->type == LE_LINK &&
7792 hci_bdaddr_list_lookup(&hcon->hdev->reject_list, &hcon->dst,
7793 bdaddr_dst_type(hcon))) {
7794 kfree_skb(skb);
7795 return;
7796 }
7797
7798 BT_DBG("len %d, cid 0x%4.4x", len, cid);
7799
7800 switch (cid) {
7801 case L2CAP_CID_SIGNALING:
7802 l2cap_sig_channel(conn, skb);
7803 break;
7804
7805 case L2CAP_CID_CONN_LESS:
7806 psm = get_unaligned((__le16 *) skb->data);
7807 skb_pull(skb, L2CAP_PSMLEN_SIZE);
7808 l2cap_conless_channel(conn, psm, skb);
7809 break;
7810
7811 case L2CAP_CID_LE_SIGNALING:
7812 l2cap_le_sig_channel(conn, skb);
7813 break;
7814
7815 default:
7816 l2cap_data_channel(conn, cid, skb);
7817 break;
7818 }
7819 }
7820
process_pending_rx(struct work_struct * work)7821 static void process_pending_rx(struct work_struct *work)
7822 {
7823 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
7824 pending_rx_work);
7825 struct sk_buff *skb;
7826
7827 BT_DBG("");
7828
7829 while ((skb = skb_dequeue(&conn->pending_rx)))
7830 l2cap_recv_frame(conn, skb);
7831 }
7832
l2cap_conn_add(struct hci_conn * hcon)7833 static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon)
7834 {
7835 struct l2cap_conn *conn = hcon->l2cap_data;
7836 struct hci_chan *hchan;
7837
7838 if (conn)
7839 return conn;
7840
7841 hchan = hci_chan_create(hcon);
7842 if (!hchan)
7843 return NULL;
7844
7845 conn = kzalloc(sizeof(*conn), GFP_KERNEL);
7846 if (!conn) {
7847 hci_chan_del(hchan);
7848 return NULL;
7849 }
7850
7851 kref_init(&conn->ref);
7852 hcon->l2cap_data = conn;
7853 conn->hcon = hci_conn_get(hcon);
7854 conn->hchan = hchan;
7855
7856 BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan);
7857
7858 switch (hcon->type) {
7859 case LE_LINK:
7860 if (hcon->hdev->le_mtu) {
7861 conn->mtu = hcon->hdev->le_mtu;
7862 break;
7863 }
7864 fallthrough;
7865 default:
7866 conn->mtu = hcon->hdev->acl_mtu;
7867 break;
7868 }
7869
7870 conn->feat_mask = 0;
7871
7872 conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS;
7873
7874 if (hcon->type == ACL_LINK &&
7875 hci_dev_test_flag(hcon->hdev, HCI_HS_ENABLED))
7876 conn->local_fixed_chan |= L2CAP_FC_A2MP;
7877
7878 if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) &&
7879 (bredr_sc_enabled(hcon->hdev) ||
7880 hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP)))
7881 conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR;
7882
7883 mutex_init(&conn->ident_lock);
7884 mutex_init(&conn->chan_lock);
7885
7886 INIT_LIST_HEAD(&conn->chan_l);
7887 INIT_LIST_HEAD(&conn->users);
7888
7889 INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout);
7890
7891 skb_queue_head_init(&conn->pending_rx);
7892 INIT_WORK(&conn->pending_rx_work, process_pending_rx);
7893 INIT_WORK(&conn->id_addr_update_work, l2cap_conn_update_id_addr);
7894
7895 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
7896
7897 return conn;
7898 }
7899
is_valid_psm(u16 psm,u8 dst_type)7900 static bool is_valid_psm(u16 psm, u8 dst_type) {
7901 if (!psm)
7902 return false;
7903
7904 if (bdaddr_type_is_le(dst_type))
7905 return (psm <= 0x00ff);
7906
7907 /* PSM must be odd and lsb of upper byte must be 0 */
7908 return ((psm & 0x0101) == 0x0001);
7909 }
7910
7911 struct l2cap_chan_data {
7912 struct l2cap_chan *chan;
7913 struct pid *pid;
7914 int count;
7915 };
7916
l2cap_chan_by_pid(struct l2cap_chan * chan,void * data)7917 static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data)
7918 {
7919 struct l2cap_chan_data *d = data;
7920 struct pid *pid;
7921
7922 if (chan == d->chan)
7923 return;
7924
7925 if (!test_bit(FLAG_DEFER_SETUP, &chan->flags))
7926 return;
7927
7928 pid = chan->ops->get_peer_pid(chan);
7929
7930 /* Only count deferred channels with the same PID/PSM */
7931 if (d->pid != pid || chan->psm != d->chan->psm || chan->ident ||
7932 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
7933 return;
7934
7935 d->count++;
7936 }
7937
l2cap_chan_connect(struct l2cap_chan * chan,__le16 psm,u16 cid,bdaddr_t * dst,u8 dst_type)7938 int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
7939 bdaddr_t *dst, u8 dst_type)
7940 {
7941 struct l2cap_conn *conn;
7942 struct hci_conn *hcon;
7943 struct hci_dev *hdev;
7944 int err;
7945
7946 BT_DBG("%pMR -> %pMR (type %u) psm 0x%4.4x mode 0x%2.2x", &chan->src,
7947 dst, dst_type, __le16_to_cpu(psm), chan->mode);
7948
7949 hdev = hci_get_route(dst, &chan->src, chan->src_type);
7950 if (!hdev)
7951 return -EHOSTUNREACH;
7952
7953 hci_dev_lock(hdev);
7954
7955 if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid &&
7956 chan->chan_type != L2CAP_CHAN_RAW) {
7957 err = -EINVAL;
7958 goto done;
7959 }
7960
7961 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) {
7962 err = -EINVAL;
7963 goto done;
7964 }
7965
7966 if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) {
7967 err = -EINVAL;
7968 goto done;
7969 }
7970
7971 switch (chan->mode) {
7972 case L2CAP_MODE_BASIC:
7973 break;
7974 case L2CAP_MODE_LE_FLOWCTL:
7975 break;
7976 case L2CAP_MODE_EXT_FLOWCTL:
7977 if (!enable_ecred) {
7978 err = -EOPNOTSUPP;
7979 goto done;
7980 }
7981 break;
7982 case L2CAP_MODE_ERTM:
7983 case L2CAP_MODE_STREAMING:
7984 if (!disable_ertm)
7985 break;
7986 fallthrough;
7987 default:
7988 err = -EOPNOTSUPP;
7989 goto done;
7990 }
7991
7992 switch (chan->state) {
7993 case BT_CONNECT:
7994 case BT_CONNECT2:
7995 case BT_CONFIG:
7996 /* Already connecting */
7997 err = 0;
7998 goto done;
7999
8000 case BT_CONNECTED:
8001 /* Already connected */
8002 err = -EISCONN;
8003 goto done;
8004
8005 case BT_OPEN:
8006 case BT_BOUND:
8007 /* Can connect */
8008 break;
8009
8010 default:
8011 err = -EBADFD;
8012 goto done;
8013 }
8014
8015 /* Set destination address and psm */
8016 bacpy(&chan->dst, dst);
8017 chan->dst_type = dst_type;
8018
8019 chan->psm = psm;
8020 chan->dcid = cid;
8021
8022 if (bdaddr_type_is_le(dst_type)) {
8023 /* Convert from L2CAP channel address type to HCI address type
8024 */
8025 if (dst_type == BDADDR_LE_PUBLIC)
8026 dst_type = ADDR_LE_DEV_PUBLIC;
8027 else
8028 dst_type = ADDR_LE_DEV_RANDOM;
8029
8030 if (hci_dev_test_flag(hdev, HCI_ADVERTISING))
8031 hcon = hci_connect_le(hdev, dst, dst_type,
8032 chan->sec_level,
8033 HCI_LE_CONN_TIMEOUT,
8034 HCI_ROLE_SLAVE, NULL);
8035 else
8036 hcon = hci_connect_le_scan(hdev, dst, dst_type,
8037 chan->sec_level,
8038 HCI_LE_CONN_TIMEOUT,
8039 CONN_REASON_L2CAP_CHAN);
8040
8041 } else {
8042 u8 auth_type = l2cap_get_auth_type(chan);
8043 hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type,
8044 CONN_REASON_L2CAP_CHAN);
8045 }
8046
8047 if (IS_ERR(hcon)) {
8048 err = PTR_ERR(hcon);
8049 goto done;
8050 }
8051
8052 conn = l2cap_conn_add(hcon);
8053 if (!conn) {
8054 hci_conn_drop(hcon);
8055 err = -ENOMEM;
8056 goto done;
8057 }
8058
8059 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) {
8060 struct l2cap_chan_data data;
8061
8062 data.chan = chan;
8063 data.pid = chan->ops->get_peer_pid(chan);
8064 data.count = 1;
8065
8066 l2cap_chan_list(conn, l2cap_chan_by_pid, &data);
8067
8068 /* Check if there isn't too many channels being connected */
8069 if (data.count > L2CAP_ECRED_CONN_SCID_MAX) {
8070 hci_conn_drop(hcon);
8071 err = -EPROTO;
8072 goto done;
8073 }
8074 }
8075
8076 mutex_lock(&conn->chan_lock);
8077 l2cap_chan_lock(chan);
8078
8079 if (cid && __l2cap_get_chan_by_dcid(conn, cid)) {
8080 hci_conn_drop(hcon);
8081 err = -EBUSY;
8082 goto chan_unlock;
8083 }
8084
8085 /* Update source addr of the socket */
8086 bacpy(&chan->src, &hcon->src);
8087 chan->src_type = bdaddr_src_type(hcon);
8088
8089 __l2cap_chan_add(conn, chan);
8090
8091 /* l2cap_chan_add takes its own ref so we can drop this one */
8092 hci_conn_drop(hcon);
8093
8094 l2cap_state_change(chan, BT_CONNECT);
8095 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
8096
8097 /* Release chan->sport so that it can be reused by other
8098 * sockets (as it's only used for listening sockets).
8099 */
8100 write_lock(&chan_list_lock);
8101 chan->sport = 0;
8102 write_unlock(&chan_list_lock);
8103
8104 if (hcon->state == BT_CONNECTED) {
8105 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
8106 __clear_chan_timer(chan);
8107 if (l2cap_chan_check_security(chan, true))
8108 l2cap_state_change(chan, BT_CONNECTED);
8109 } else
8110 l2cap_do_start(chan);
8111 }
8112
8113 err = 0;
8114
8115 chan_unlock:
8116 l2cap_chan_unlock(chan);
8117 mutex_unlock(&conn->chan_lock);
8118 done:
8119 hci_dev_unlock(hdev);
8120 hci_dev_put(hdev);
8121 return err;
8122 }
8123 EXPORT_SYMBOL_GPL(l2cap_chan_connect);
8124
l2cap_ecred_reconfigure(struct l2cap_chan * chan)8125 static void l2cap_ecred_reconfigure(struct l2cap_chan *chan)
8126 {
8127 struct l2cap_conn *conn = chan->conn;
8128 struct {
8129 struct l2cap_ecred_reconf_req req;
8130 __le16 scid;
8131 } pdu;
8132
8133 pdu.req.mtu = cpu_to_le16(chan->imtu);
8134 pdu.req.mps = cpu_to_le16(chan->mps);
8135 pdu.scid = cpu_to_le16(chan->scid);
8136
8137 chan->ident = l2cap_get_ident(conn);
8138
8139 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ,
8140 sizeof(pdu), &pdu);
8141 }
8142
l2cap_chan_reconfigure(struct l2cap_chan * chan,__u16 mtu)8143 int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu)
8144 {
8145 if (chan->imtu > mtu)
8146 return -EINVAL;
8147
8148 BT_DBG("chan %p mtu 0x%4.4x", chan, mtu);
8149
8150 chan->imtu = mtu;
8151
8152 l2cap_ecred_reconfigure(chan);
8153
8154 return 0;
8155 }
8156
8157 /* ---- L2CAP interface with lower layer (HCI) ---- */
8158
l2cap_connect_ind(struct hci_dev * hdev,bdaddr_t * bdaddr)8159 int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr)
8160 {
8161 int exact = 0, lm1 = 0, lm2 = 0;
8162 struct l2cap_chan *c;
8163
8164 BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr);
8165
8166 /* Find listening sockets and check their link_mode */
8167 read_lock(&chan_list_lock);
8168 list_for_each_entry(c, &chan_list, global_l) {
8169 if (c->state != BT_LISTEN)
8170 continue;
8171
8172 if (!bacmp(&c->src, &hdev->bdaddr)) {
8173 lm1 |= HCI_LM_ACCEPT;
8174 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
8175 lm1 |= HCI_LM_MASTER;
8176 exact++;
8177 } else if (!bacmp(&c->src, BDADDR_ANY)) {
8178 lm2 |= HCI_LM_ACCEPT;
8179 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
8180 lm2 |= HCI_LM_MASTER;
8181 }
8182 }
8183 read_unlock(&chan_list_lock);
8184
8185 return exact ? lm1 : lm2;
8186 }
8187
8188 /* Find the next fixed channel in BT_LISTEN state, continue iteration
8189 * from an existing channel in the list or from the beginning of the
8190 * global list (by passing NULL as first parameter).
8191 */
l2cap_global_fixed_chan(struct l2cap_chan * c,struct hci_conn * hcon)8192 static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c,
8193 struct hci_conn *hcon)
8194 {
8195 u8 src_type = bdaddr_src_type(hcon);
8196
8197 read_lock(&chan_list_lock);
8198
8199 if (c)
8200 c = list_next_entry(c, global_l);
8201 else
8202 c = list_entry(chan_list.next, typeof(*c), global_l);
8203
8204 list_for_each_entry_from(c, &chan_list, global_l) {
8205 if (c->chan_type != L2CAP_CHAN_FIXED)
8206 continue;
8207 if (c->state != BT_LISTEN)
8208 continue;
8209 if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY))
8210 continue;
8211 if (src_type != c->src_type)
8212 continue;
8213
8214 c = l2cap_chan_hold_unless_zero(c);
8215 read_unlock(&chan_list_lock);
8216 return c;
8217 }
8218
8219 read_unlock(&chan_list_lock);
8220
8221 return NULL;
8222 }
8223
l2cap_connect_cfm(struct hci_conn * hcon,u8 status)8224 static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status)
8225 {
8226 struct hci_dev *hdev = hcon->hdev;
8227 struct l2cap_conn *conn;
8228 struct l2cap_chan *pchan;
8229 u8 dst_type;
8230
8231 if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
8232 return;
8233
8234 BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status);
8235
8236 if (status) {
8237 l2cap_conn_del(hcon, bt_to_errno(status));
8238 return;
8239 }
8240
8241 conn = l2cap_conn_add(hcon);
8242 if (!conn)
8243 return;
8244
8245 dst_type = bdaddr_dst_type(hcon);
8246
8247 /* If device is blocked, do not create channels for it */
8248 if (hci_bdaddr_list_lookup(&hdev->reject_list, &hcon->dst, dst_type))
8249 return;
8250
8251 /* Find fixed channels and notify them of the new connection. We
8252 * use multiple individual lookups, continuing each time where
8253 * we left off, because the list lock would prevent calling the
8254 * potentially sleeping l2cap_chan_lock() function.
8255 */
8256 pchan = l2cap_global_fixed_chan(NULL, hcon);
8257 while (pchan) {
8258 struct l2cap_chan *chan, *next;
8259
8260 /* Client fixed channels should override server ones */
8261 if (__l2cap_get_chan_by_dcid(conn, pchan->scid))
8262 goto next;
8263
8264 l2cap_chan_lock(pchan);
8265 chan = pchan->ops->new_connection(pchan);
8266 if (chan) {
8267 bacpy(&chan->src, &hcon->src);
8268 bacpy(&chan->dst, &hcon->dst);
8269 chan->src_type = bdaddr_src_type(hcon);
8270 chan->dst_type = dst_type;
8271
8272 __l2cap_chan_add(conn, chan);
8273 }
8274
8275 l2cap_chan_unlock(pchan);
8276 next:
8277 next = l2cap_global_fixed_chan(pchan, hcon);
8278 l2cap_chan_put(pchan);
8279 pchan = next;
8280 }
8281
8282 l2cap_conn_ready(conn);
8283 }
8284
l2cap_disconn_ind(struct hci_conn * hcon)8285 int l2cap_disconn_ind(struct hci_conn *hcon)
8286 {
8287 struct l2cap_conn *conn = hcon->l2cap_data;
8288
8289 BT_DBG("hcon %p", hcon);
8290
8291 if (!conn)
8292 return HCI_ERROR_REMOTE_USER_TERM;
8293 return conn->disc_reason;
8294 }
8295
l2cap_disconn_cfm(struct hci_conn * hcon,u8 reason)8296 static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)
8297 {
8298 if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
8299 return;
8300
8301 BT_DBG("hcon %p reason %d", hcon, reason);
8302
8303 l2cap_conn_del(hcon, bt_to_errno(reason));
8304 }
8305
l2cap_check_encryption(struct l2cap_chan * chan,u8 encrypt)8306 static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt)
8307 {
8308 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
8309 return;
8310
8311 if (encrypt == 0x00) {
8312 if (chan->sec_level == BT_SECURITY_MEDIUM) {
8313 __set_chan_timer(chan, L2CAP_ENC_TIMEOUT);
8314 } else if (chan->sec_level == BT_SECURITY_HIGH ||
8315 chan->sec_level == BT_SECURITY_FIPS)
8316 l2cap_chan_close(chan, ECONNREFUSED);
8317 } else {
8318 if (chan->sec_level == BT_SECURITY_MEDIUM)
8319 __clear_chan_timer(chan);
8320 }
8321 }
8322
l2cap_security_cfm(struct hci_conn * hcon,u8 status,u8 encrypt)8323 static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
8324 {
8325 struct l2cap_conn *conn = hcon->l2cap_data;
8326 struct l2cap_chan *chan;
8327
8328 if (!conn)
8329 return;
8330
8331 BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt);
8332
8333 mutex_lock(&conn->chan_lock);
8334
8335 list_for_each_entry(chan, &conn->chan_l, list) {
8336 l2cap_chan_lock(chan);
8337
8338 BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid,
8339 state_to_string(chan->state));
8340
8341 if (chan->scid == L2CAP_CID_A2MP) {
8342 l2cap_chan_unlock(chan);
8343 continue;
8344 }
8345
8346 if (!status && encrypt)
8347 chan->sec_level = hcon->sec_level;
8348
8349 if (!__l2cap_no_conn_pending(chan)) {
8350 l2cap_chan_unlock(chan);
8351 continue;
8352 }
8353
8354 if (!status && (chan->state == BT_CONNECTED ||
8355 chan->state == BT_CONFIG)) {
8356 chan->ops->resume(chan);
8357 l2cap_check_encryption(chan, encrypt);
8358 l2cap_chan_unlock(chan);
8359 continue;
8360 }
8361
8362 if (chan->state == BT_CONNECT) {
8363 if (!status && l2cap_check_enc_key_size(hcon))
8364 l2cap_start_connection(chan);
8365 else
8366 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
8367 } else if (chan->state == BT_CONNECT2 &&
8368 !(chan->mode == L2CAP_MODE_EXT_FLOWCTL ||
8369 chan->mode == L2CAP_MODE_LE_FLOWCTL)) {
8370 struct l2cap_conn_rsp rsp;
8371 __u16 res, stat;
8372
8373 if (!status && l2cap_check_enc_key_size(hcon)) {
8374 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
8375 res = L2CAP_CR_PEND;
8376 stat = L2CAP_CS_AUTHOR_PEND;
8377 chan->ops->defer(chan);
8378 } else {
8379 l2cap_state_change(chan, BT_CONFIG);
8380 res = L2CAP_CR_SUCCESS;
8381 stat = L2CAP_CS_NO_INFO;
8382 }
8383 } else {
8384 l2cap_state_change(chan, BT_DISCONN);
8385 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
8386 res = L2CAP_CR_SEC_BLOCK;
8387 stat = L2CAP_CS_NO_INFO;
8388 }
8389
8390 rsp.scid = cpu_to_le16(chan->dcid);
8391 rsp.dcid = cpu_to_le16(chan->scid);
8392 rsp.result = cpu_to_le16(res);
8393 rsp.status = cpu_to_le16(stat);
8394 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
8395 sizeof(rsp), &rsp);
8396
8397 if (!test_bit(CONF_REQ_SENT, &chan->conf_state) &&
8398 res == L2CAP_CR_SUCCESS) {
8399 char buf[128];
8400 set_bit(CONF_REQ_SENT, &chan->conf_state);
8401 l2cap_send_cmd(conn, l2cap_get_ident(conn),
8402 L2CAP_CONF_REQ,
8403 l2cap_build_conf_req(chan, buf, sizeof(buf)),
8404 buf);
8405 chan->num_conf_req++;
8406 }
8407 }
8408
8409 l2cap_chan_unlock(chan);
8410 }
8411
8412 mutex_unlock(&conn->chan_lock);
8413 }
8414
l2cap_recv_acldata(struct hci_conn * hcon,struct sk_buff * skb,u16 flags)8415 void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
8416 {
8417 struct l2cap_conn *conn = hcon->l2cap_data;
8418 struct l2cap_hdr *hdr;
8419 int len;
8420
8421 /* For AMP controller do not create l2cap conn */
8422 if (!conn && hcon->hdev->dev_type != HCI_PRIMARY)
8423 goto drop;
8424
8425 if (!conn)
8426 conn = l2cap_conn_add(hcon);
8427
8428 if (!conn)
8429 goto drop;
8430
8431 BT_DBG("conn %p len %d flags 0x%x", conn, skb->len, flags);
8432
8433 switch (flags) {
8434 case ACL_START:
8435 case ACL_START_NO_FLUSH:
8436 case ACL_COMPLETE:
8437 if (conn->rx_len) {
8438 BT_ERR("Unexpected start frame (len %d)", skb->len);
8439 kfree_skb(conn->rx_skb);
8440 conn->rx_skb = NULL;
8441 conn->rx_len = 0;
8442 l2cap_conn_unreliable(conn, ECOMM);
8443 }
8444
8445 /* Start fragment always begin with Basic L2CAP header */
8446 if (skb->len < L2CAP_HDR_SIZE) {
8447 BT_ERR("Frame is too short (len %d)", skb->len);
8448 l2cap_conn_unreliable(conn, ECOMM);
8449 goto drop;
8450 }
8451
8452 hdr = (struct l2cap_hdr *) skb->data;
8453 len = __le16_to_cpu(hdr->len) + L2CAP_HDR_SIZE;
8454
8455 if (len == skb->len) {
8456 /* Complete frame received */
8457 l2cap_recv_frame(conn, skb);
8458 return;
8459 }
8460
8461 BT_DBG("Start: total len %d, frag len %d", len, skb->len);
8462
8463 if (skb->len > len) {
8464 BT_ERR("Frame is too long (len %d, expected len %d)",
8465 skb->len, len);
8466 l2cap_conn_unreliable(conn, ECOMM);
8467 goto drop;
8468 }
8469
8470 /* Allocate skb for the complete frame (with header) */
8471 conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL);
8472 if (!conn->rx_skb)
8473 goto drop;
8474
8475 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len),
8476 skb->len);
8477 conn->rx_len = len - skb->len;
8478 break;
8479
8480 case ACL_CONT:
8481 BT_DBG("Cont: frag len %d (expecting %d)", skb->len, conn->rx_len);
8482
8483 if (!conn->rx_len) {
8484 BT_ERR("Unexpected continuation frame (len %d)", skb->len);
8485 l2cap_conn_unreliable(conn, ECOMM);
8486 goto drop;
8487 }
8488
8489 if (skb->len > conn->rx_len) {
8490 BT_ERR("Fragment is too long (len %d, expected %d)",
8491 skb->len, conn->rx_len);
8492 kfree_skb(conn->rx_skb);
8493 conn->rx_skb = NULL;
8494 conn->rx_len = 0;
8495 l2cap_conn_unreliable(conn, ECOMM);
8496 goto drop;
8497 }
8498
8499 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len),
8500 skb->len);
8501 conn->rx_len -= skb->len;
8502
8503 if (!conn->rx_len) {
8504 /* Complete frame received. l2cap_recv_frame
8505 * takes ownership of the skb so set the global
8506 * rx_skb pointer to NULL first.
8507 */
8508 struct sk_buff *rx_skb = conn->rx_skb;
8509 conn->rx_skb = NULL;
8510 l2cap_recv_frame(conn, rx_skb);
8511 }
8512 break;
8513 }
8514
8515 drop:
8516 kfree_skb(skb);
8517 }
8518
8519 static struct hci_cb l2cap_cb = {
8520 .name = "L2CAP",
8521 .connect_cfm = l2cap_connect_cfm,
8522 .disconn_cfm = l2cap_disconn_cfm,
8523 .security_cfm = l2cap_security_cfm,
8524 };
8525
l2cap_debugfs_show(struct seq_file * f,void * p)8526 static int l2cap_debugfs_show(struct seq_file *f, void *p)
8527 {
8528 struct l2cap_chan *c;
8529
8530 read_lock(&chan_list_lock);
8531
8532 list_for_each_entry(c, &chan_list, global_l) {
8533 seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n",
8534 &c->src, c->src_type, &c->dst, c->dst_type,
8535 c->state, __le16_to_cpu(c->psm),
8536 c->scid, c->dcid, c->imtu, c->omtu,
8537 c->sec_level, c->mode);
8538 }
8539
8540 read_unlock(&chan_list_lock);
8541
8542 return 0;
8543 }
8544
8545 DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs);
8546
8547 static struct dentry *l2cap_debugfs;
8548
l2cap_init(void)8549 int __init l2cap_init(void)
8550 {
8551 int err;
8552
8553 err = l2cap_init_sockets();
8554 if (err < 0)
8555 return err;
8556
8557 hci_register_cb(&l2cap_cb);
8558
8559 if (IS_ERR_OR_NULL(bt_debugfs))
8560 return 0;
8561
8562 l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs,
8563 NULL, &l2cap_debugfs_fops);
8564
8565 return 0;
8566 }
8567
l2cap_exit(void)8568 void l2cap_exit(void)
8569 {
8570 debugfs_remove(l2cap_debugfs);
8571 hci_unregister_cb(&l2cap_cb);
8572 l2cap_cleanup_sockets();
8573 }
8574
8575 module_param(disable_ertm, bool, 0644);
8576 MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode");
8577
8578 module_param(enable_ecred, bool, 0644);
8579 MODULE_PARM_DESC(enable_ecred, "Enable enhanced credit flow control mode");
8580