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[thirdparty/kernel/linux.git] / net / bluetooth / l2cap_core.c
1 /*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2000-2001 Qualcomm Incorporated
4 Copyright (C) 2009-2010 Gustavo F. Padovan <gustavo@padovan.org>
5 Copyright (C) 2010 Google Inc.
6 Copyright (C) 2011 ProFUSION Embedded Systems
7 Copyright (c) 2012 Code Aurora Forum. All rights reserved.
8
9 Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
10
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License version 2 as
13 published by the Free Software Foundation;
14
15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
16 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
18 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
19 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
20 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
21 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
22 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23
24 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
25 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
26 SOFTWARE IS DISCLAIMED.
27 */
28
29 /* Bluetooth L2CAP core. */
30
31 #include <linux/module.h>
32
33 #include <linux/debugfs.h>
34 #include <linux/crc16.h>
35 #include <linux/filter.h>
36
37 #include <net/bluetooth/bluetooth.h>
38 #include <net/bluetooth/hci_core.h>
39 #include <net/bluetooth/l2cap.h>
40
41 #include "smp.h"
42 #include "a2mp.h"
43 #include "amp.h"
44
45 #define LE_FLOWCTL_MAX_CREDITS 65535
46
47 bool disable_ertm;
48
49 static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN | L2CAP_FEAT_UCD;
50
51 static LIST_HEAD(chan_list);
52 static DEFINE_RWLOCK(chan_list_lock);
53
54 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
55 u8 code, u8 ident, u16 dlen, void *data);
56 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
57 void *data);
58 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size);
59 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err);
60
61 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
62 struct sk_buff_head *skbs, u8 event);
63
64 static inline u8 bdaddr_type(u8 link_type, u8 bdaddr_type)
65 {
66 if (link_type == LE_LINK) {
67 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
68 return BDADDR_LE_PUBLIC;
69 else
70 return BDADDR_LE_RANDOM;
71 }
72
73 return BDADDR_BREDR;
74 }
75
76 static inline u8 bdaddr_src_type(struct hci_conn *hcon)
77 {
78 return bdaddr_type(hcon->type, hcon->src_type);
79 }
80
81 static inline u8 bdaddr_dst_type(struct hci_conn *hcon)
82 {
83 return bdaddr_type(hcon->type, hcon->dst_type);
84 }
85
86 /* ---- L2CAP channels ---- */
87
88 static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
89 u16 cid)
90 {
91 struct l2cap_chan *c;
92
93 list_for_each_entry(c, &conn->chan_l, list) {
94 if (c->dcid == cid)
95 return c;
96 }
97 return NULL;
98 }
99
100 static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn,
101 u16 cid)
102 {
103 struct l2cap_chan *c;
104
105 list_for_each_entry(c, &conn->chan_l, list) {
106 if (c->scid == cid)
107 return c;
108 }
109 return NULL;
110 }
111
112 /* Find channel with given SCID.
113 * Returns locked channel. */
114 static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn,
115 u16 cid)
116 {
117 struct l2cap_chan *c;
118
119 mutex_lock(&conn->chan_lock);
120 c = __l2cap_get_chan_by_scid(conn, cid);
121 if (c)
122 l2cap_chan_lock(c);
123 mutex_unlock(&conn->chan_lock);
124
125 return c;
126 }
127
128 /* Find channel with given DCID.
129 * Returns locked channel.
130 */
131 static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
132 u16 cid)
133 {
134 struct l2cap_chan *c;
135
136 mutex_lock(&conn->chan_lock);
137 c = __l2cap_get_chan_by_dcid(conn, cid);
138 if (c)
139 l2cap_chan_lock(c);
140 mutex_unlock(&conn->chan_lock);
141
142 return c;
143 }
144
145 static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn,
146 u8 ident)
147 {
148 struct l2cap_chan *c;
149
150 list_for_each_entry(c, &conn->chan_l, list) {
151 if (c->ident == ident)
152 return c;
153 }
154 return NULL;
155 }
156
157 static struct l2cap_chan *l2cap_get_chan_by_ident(struct l2cap_conn *conn,
158 u8 ident)
159 {
160 struct l2cap_chan *c;
161
162 mutex_lock(&conn->chan_lock);
163 c = __l2cap_get_chan_by_ident(conn, ident);
164 if (c)
165 l2cap_chan_lock(c);
166 mutex_unlock(&conn->chan_lock);
167
168 return c;
169 }
170
171 static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src)
172 {
173 struct l2cap_chan *c;
174
175 list_for_each_entry(c, &chan_list, global_l) {
176 if (c->sport == psm && !bacmp(&c->src, src))
177 return c;
178 }
179 return NULL;
180 }
181
182 int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm)
183 {
184 int err;
185
186 write_lock(&chan_list_lock);
187
188 if (psm && __l2cap_global_chan_by_addr(psm, src)) {
189 err = -EADDRINUSE;
190 goto done;
191 }
192
193 if (psm) {
194 chan->psm = psm;
195 chan->sport = psm;
196 err = 0;
197 } else {
198 u16 p, start, end, incr;
199
200 if (chan->src_type == BDADDR_BREDR) {
201 start = L2CAP_PSM_DYN_START;
202 end = L2CAP_PSM_AUTO_END;
203 incr = 2;
204 } else {
205 start = L2CAP_PSM_LE_DYN_START;
206 end = L2CAP_PSM_LE_DYN_END;
207 incr = 1;
208 }
209
210 err = -EINVAL;
211 for (p = start; p <= end; p += incr)
212 if (!__l2cap_global_chan_by_addr(cpu_to_le16(p), src)) {
213 chan->psm = cpu_to_le16(p);
214 chan->sport = cpu_to_le16(p);
215 err = 0;
216 break;
217 }
218 }
219
220 done:
221 write_unlock(&chan_list_lock);
222 return err;
223 }
224 EXPORT_SYMBOL_GPL(l2cap_add_psm);
225
226 int l2cap_add_scid(struct l2cap_chan *chan, __u16 scid)
227 {
228 write_lock(&chan_list_lock);
229
230 /* Override the defaults (which are for conn-oriented) */
231 chan->omtu = L2CAP_DEFAULT_MTU;
232 chan->chan_type = L2CAP_CHAN_FIXED;
233
234 chan->scid = scid;
235
236 write_unlock(&chan_list_lock);
237
238 return 0;
239 }
240
241 static u16 l2cap_alloc_cid(struct l2cap_conn *conn)
242 {
243 u16 cid, dyn_end;
244
245 if (conn->hcon->type == LE_LINK)
246 dyn_end = L2CAP_CID_LE_DYN_END;
247 else
248 dyn_end = L2CAP_CID_DYN_END;
249
250 for (cid = L2CAP_CID_DYN_START; cid <= dyn_end; cid++) {
251 if (!__l2cap_get_chan_by_scid(conn, cid))
252 return cid;
253 }
254
255 return 0;
256 }
257
258 static void l2cap_state_change(struct l2cap_chan *chan, int state)
259 {
260 BT_DBG("chan %p %s -> %s", chan, state_to_string(chan->state),
261 state_to_string(state));
262
263 chan->state = state;
264 chan->ops->state_change(chan, state, 0);
265 }
266
267 static inline void l2cap_state_change_and_error(struct l2cap_chan *chan,
268 int state, int err)
269 {
270 chan->state = state;
271 chan->ops->state_change(chan, chan->state, err);
272 }
273
274 static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
275 {
276 chan->ops->state_change(chan, chan->state, err);
277 }
278
279 static void __set_retrans_timer(struct l2cap_chan *chan)
280 {
281 if (!delayed_work_pending(&chan->monitor_timer) &&
282 chan->retrans_timeout) {
283 l2cap_set_timer(chan, &chan->retrans_timer,
284 msecs_to_jiffies(chan->retrans_timeout));
285 }
286 }
287
288 static void __set_monitor_timer(struct l2cap_chan *chan)
289 {
290 __clear_retrans_timer(chan);
291 if (chan->monitor_timeout) {
292 l2cap_set_timer(chan, &chan->monitor_timer,
293 msecs_to_jiffies(chan->monitor_timeout));
294 }
295 }
296
297 static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head,
298 u16 seq)
299 {
300 struct sk_buff *skb;
301
302 skb_queue_walk(head, skb) {
303 if (bt_cb(skb)->l2cap.txseq == seq)
304 return skb;
305 }
306
307 return NULL;
308 }
309
310 /* ---- L2CAP sequence number lists ---- */
311
312 /* For ERTM, ordered lists of sequence numbers must be tracked for
313 * SREJ requests that are received and for frames that are to be
314 * retransmitted. These seq_list functions implement a singly-linked
315 * list in an array, where membership in the list can also be checked
316 * in constant time. Items can also be added to the tail of the list
317 * and removed from the head in constant time, without further memory
318 * allocs or frees.
319 */
320
321 static int l2cap_seq_list_init(struct l2cap_seq_list *seq_list, u16 size)
322 {
323 size_t alloc_size, i;
324
325 /* Allocated size is a power of 2 to map sequence numbers
326 * (which may be up to 14 bits) in to a smaller array that is
327 * sized for the negotiated ERTM transmit windows.
328 */
329 alloc_size = roundup_pow_of_two(size);
330
331 seq_list->list = kmalloc_array(alloc_size, sizeof(u16), GFP_KERNEL);
332 if (!seq_list->list)
333 return -ENOMEM;
334
335 seq_list->mask = alloc_size - 1;
336 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
337 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
338 for (i = 0; i < alloc_size; i++)
339 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
340
341 return 0;
342 }
343
344 static inline void l2cap_seq_list_free(struct l2cap_seq_list *seq_list)
345 {
346 kfree(seq_list->list);
347 }
348
349 static inline bool l2cap_seq_list_contains(struct l2cap_seq_list *seq_list,
350 u16 seq)
351 {
352 /* Constant-time check for list membership */
353 return seq_list->list[seq & seq_list->mask] != L2CAP_SEQ_LIST_CLEAR;
354 }
355
356 static inline u16 l2cap_seq_list_pop(struct l2cap_seq_list *seq_list)
357 {
358 u16 seq = seq_list->head;
359 u16 mask = seq_list->mask;
360
361 seq_list->head = seq_list->list[seq & mask];
362 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_CLEAR;
363
364 if (seq_list->head == L2CAP_SEQ_LIST_TAIL) {
365 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
366 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
367 }
368
369 return seq;
370 }
371
372 static void l2cap_seq_list_clear(struct l2cap_seq_list *seq_list)
373 {
374 u16 i;
375
376 if (seq_list->head == L2CAP_SEQ_LIST_CLEAR)
377 return;
378
379 for (i = 0; i <= seq_list->mask; i++)
380 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
381
382 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
383 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
384 }
385
386 static void l2cap_seq_list_append(struct l2cap_seq_list *seq_list, u16 seq)
387 {
388 u16 mask = seq_list->mask;
389
390 /* All appends happen in constant time */
391
392 if (seq_list->list[seq & mask] != L2CAP_SEQ_LIST_CLEAR)
393 return;
394
395 if (seq_list->tail == L2CAP_SEQ_LIST_CLEAR)
396 seq_list->head = seq;
397 else
398 seq_list->list[seq_list->tail & mask] = seq;
399
400 seq_list->tail = seq;
401 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_TAIL;
402 }
403
404 static void l2cap_chan_timeout(struct work_struct *work)
405 {
406 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
407 chan_timer.work);
408 struct l2cap_conn *conn = chan->conn;
409 int reason;
410
411 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
412
413 mutex_lock(&conn->chan_lock);
414 l2cap_chan_lock(chan);
415
416 if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
417 reason = ECONNREFUSED;
418 else if (chan->state == BT_CONNECT &&
419 chan->sec_level != BT_SECURITY_SDP)
420 reason = ECONNREFUSED;
421 else
422 reason = ETIMEDOUT;
423
424 l2cap_chan_close(chan, reason);
425
426 l2cap_chan_unlock(chan);
427
428 chan->ops->close(chan);
429 mutex_unlock(&conn->chan_lock);
430
431 l2cap_chan_put(chan);
432 }
433
434 struct l2cap_chan *l2cap_chan_create(void)
435 {
436 struct l2cap_chan *chan;
437
438 chan = kzalloc(sizeof(*chan), GFP_ATOMIC);
439 if (!chan)
440 return NULL;
441
442 mutex_init(&chan->lock);
443
444 /* Set default lock nesting level */
445 atomic_set(&chan->nesting, L2CAP_NESTING_NORMAL);
446
447 write_lock(&chan_list_lock);
448 list_add(&chan->global_l, &chan_list);
449 write_unlock(&chan_list_lock);
450
451 INIT_DELAYED_WORK(&chan->chan_timer, l2cap_chan_timeout);
452
453 chan->state = BT_OPEN;
454
455 kref_init(&chan->kref);
456
457 /* This flag is cleared in l2cap_chan_ready() */
458 set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
459
460 BT_DBG("chan %p", chan);
461
462 return chan;
463 }
464 EXPORT_SYMBOL_GPL(l2cap_chan_create);
465
466 static void l2cap_chan_destroy(struct kref *kref)
467 {
468 struct l2cap_chan *chan = container_of(kref, struct l2cap_chan, kref);
469
470 BT_DBG("chan %p", chan);
471
472 write_lock(&chan_list_lock);
473 list_del(&chan->global_l);
474 write_unlock(&chan_list_lock);
475
476 kfree(chan);
477 }
478
479 void l2cap_chan_hold(struct l2cap_chan *c)
480 {
481 BT_DBG("chan %p orig refcnt %d", c, kref_read(&c->kref));
482
483 kref_get(&c->kref);
484 }
485
486 void l2cap_chan_put(struct l2cap_chan *c)
487 {
488 BT_DBG("chan %p orig refcnt %d", c, kref_read(&c->kref));
489
490 kref_put(&c->kref, l2cap_chan_destroy);
491 }
492 EXPORT_SYMBOL_GPL(l2cap_chan_put);
493
494 void l2cap_chan_set_defaults(struct l2cap_chan *chan)
495 {
496 chan->fcs = L2CAP_FCS_CRC16;
497 chan->max_tx = L2CAP_DEFAULT_MAX_TX;
498 chan->tx_win = L2CAP_DEFAULT_TX_WINDOW;
499 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
500 chan->remote_max_tx = chan->max_tx;
501 chan->remote_tx_win = chan->tx_win;
502 chan->ack_win = L2CAP_DEFAULT_TX_WINDOW;
503 chan->sec_level = BT_SECURITY_LOW;
504 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
505 chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO;
506 chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO;
507 chan->conf_state = 0;
508
509 set_bit(FLAG_FORCE_ACTIVE, &chan->flags);
510 }
511 EXPORT_SYMBOL_GPL(l2cap_chan_set_defaults);
512
513 static void l2cap_le_flowctl_init(struct l2cap_chan *chan, u16 tx_credits)
514 {
515 chan->sdu = NULL;
516 chan->sdu_last_frag = NULL;
517 chan->sdu_len = 0;
518 chan->tx_credits = tx_credits;
519 /* Derive MPS from connection MTU to stop HCI fragmentation */
520 chan->mps = min_t(u16, chan->imtu, chan->conn->mtu - L2CAP_HDR_SIZE);
521 /* Give enough credits for a full packet */
522 chan->rx_credits = (chan->imtu / chan->mps) + 1;
523
524 skb_queue_head_init(&chan->tx_q);
525 }
526
527 void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
528 {
529 BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn,
530 __le16_to_cpu(chan->psm), chan->dcid);
531
532 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
533
534 chan->conn = conn;
535
536 switch (chan->chan_type) {
537 case L2CAP_CHAN_CONN_ORIENTED:
538 /* Alloc CID for connection-oriented socket */
539 chan->scid = l2cap_alloc_cid(conn);
540 if (conn->hcon->type == ACL_LINK)
541 chan->omtu = L2CAP_DEFAULT_MTU;
542 break;
543
544 case L2CAP_CHAN_CONN_LESS:
545 /* Connectionless socket */
546 chan->scid = L2CAP_CID_CONN_LESS;
547 chan->dcid = L2CAP_CID_CONN_LESS;
548 chan->omtu = L2CAP_DEFAULT_MTU;
549 break;
550
551 case L2CAP_CHAN_FIXED:
552 /* Caller will set CID and CID specific MTU values */
553 break;
554
555 default:
556 /* Raw socket can send/recv signalling messages only */
557 chan->scid = L2CAP_CID_SIGNALING;
558 chan->dcid = L2CAP_CID_SIGNALING;
559 chan->omtu = L2CAP_DEFAULT_MTU;
560 }
561
562 chan->local_id = L2CAP_BESTEFFORT_ID;
563 chan->local_stype = L2CAP_SERV_BESTEFFORT;
564 chan->local_msdu = L2CAP_DEFAULT_MAX_SDU_SIZE;
565 chan->local_sdu_itime = L2CAP_DEFAULT_SDU_ITIME;
566 chan->local_acc_lat = L2CAP_DEFAULT_ACC_LAT;
567 chan->local_flush_to = L2CAP_EFS_DEFAULT_FLUSH_TO;
568
569 l2cap_chan_hold(chan);
570
571 /* Only keep a reference for fixed channels if they requested it */
572 if (chan->chan_type != L2CAP_CHAN_FIXED ||
573 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
574 hci_conn_hold(conn->hcon);
575
576 list_add(&chan->list, &conn->chan_l);
577 }
578
579 void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
580 {
581 mutex_lock(&conn->chan_lock);
582 __l2cap_chan_add(conn, chan);
583 mutex_unlock(&conn->chan_lock);
584 }
585
586 void l2cap_chan_del(struct l2cap_chan *chan, int err)
587 {
588 struct l2cap_conn *conn = chan->conn;
589
590 __clear_chan_timer(chan);
591
592 BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err,
593 state_to_string(chan->state));
594
595 chan->ops->teardown(chan, err);
596
597 if (conn) {
598 struct amp_mgr *mgr = conn->hcon->amp_mgr;
599 /* Delete from channel list */
600 list_del(&chan->list);
601
602 l2cap_chan_put(chan);
603
604 chan->conn = NULL;
605
606 /* Reference was only held for non-fixed channels or
607 * fixed channels that explicitly requested it using the
608 * FLAG_HOLD_HCI_CONN flag.
609 */
610 if (chan->chan_type != L2CAP_CHAN_FIXED ||
611 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
612 hci_conn_drop(conn->hcon);
613
614 if (mgr && mgr->bredr_chan == chan)
615 mgr->bredr_chan = NULL;
616 }
617
618 if (chan->hs_hchan) {
619 struct hci_chan *hs_hchan = chan->hs_hchan;
620
621 BT_DBG("chan %p disconnect hs_hchan %p", chan, hs_hchan);
622 amp_disconnect_logical_link(hs_hchan);
623 }
624
625 if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state))
626 return;
627
628 switch(chan->mode) {
629 case L2CAP_MODE_BASIC:
630 break;
631
632 case L2CAP_MODE_LE_FLOWCTL:
633 skb_queue_purge(&chan->tx_q);
634 break;
635
636 case L2CAP_MODE_ERTM:
637 __clear_retrans_timer(chan);
638 __clear_monitor_timer(chan);
639 __clear_ack_timer(chan);
640
641 skb_queue_purge(&chan->srej_q);
642
643 l2cap_seq_list_free(&chan->srej_list);
644 l2cap_seq_list_free(&chan->retrans_list);
645
646 /* fall through */
647
648 case L2CAP_MODE_STREAMING:
649 skb_queue_purge(&chan->tx_q);
650 break;
651 }
652
653 return;
654 }
655 EXPORT_SYMBOL_GPL(l2cap_chan_del);
656
657 static void l2cap_conn_update_id_addr(struct work_struct *work)
658 {
659 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
660 id_addr_update_work);
661 struct hci_conn *hcon = conn->hcon;
662 struct l2cap_chan *chan;
663
664 mutex_lock(&conn->chan_lock);
665
666 list_for_each_entry(chan, &conn->chan_l, list) {
667 l2cap_chan_lock(chan);
668 bacpy(&chan->dst, &hcon->dst);
669 chan->dst_type = bdaddr_dst_type(hcon);
670 l2cap_chan_unlock(chan);
671 }
672
673 mutex_unlock(&conn->chan_lock);
674 }
675
676 static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan)
677 {
678 struct l2cap_conn *conn = chan->conn;
679 struct l2cap_le_conn_rsp rsp;
680 u16 result;
681
682 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
683 result = L2CAP_CR_LE_AUTHORIZATION;
684 else
685 result = L2CAP_CR_LE_BAD_PSM;
686
687 l2cap_state_change(chan, BT_DISCONN);
688
689 rsp.dcid = cpu_to_le16(chan->scid);
690 rsp.mtu = cpu_to_le16(chan->imtu);
691 rsp.mps = cpu_to_le16(chan->mps);
692 rsp.credits = cpu_to_le16(chan->rx_credits);
693 rsp.result = cpu_to_le16(result);
694
695 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
696 &rsp);
697 }
698
699 static void l2cap_chan_connect_reject(struct l2cap_chan *chan)
700 {
701 struct l2cap_conn *conn = chan->conn;
702 struct l2cap_conn_rsp rsp;
703 u16 result;
704
705 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
706 result = L2CAP_CR_SEC_BLOCK;
707 else
708 result = L2CAP_CR_BAD_PSM;
709
710 l2cap_state_change(chan, BT_DISCONN);
711
712 rsp.scid = cpu_to_le16(chan->dcid);
713 rsp.dcid = cpu_to_le16(chan->scid);
714 rsp.result = cpu_to_le16(result);
715 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
716
717 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, sizeof(rsp), &rsp);
718 }
719
720 void l2cap_chan_close(struct l2cap_chan *chan, int reason)
721 {
722 struct l2cap_conn *conn = chan->conn;
723
724 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
725
726 switch (chan->state) {
727 case BT_LISTEN:
728 chan->ops->teardown(chan, 0);
729 break;
730
731 case BT_CONNECTED:
732 case BT_CONFIG:
733 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
734 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
735 l2cap_send_disconn_req(chan, reason);
736 } else
737 l2cap_chan_del(chan, reason);
738 break;
739
740 case BT_CONNECT2:
741 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
742 if (conn->hcon->type == ACL_LINK)
743 l2cap_chan_connect_reject(chan);
744 else if (conn->hcon->type == LE_LINK)
745 l2cap_chan_le_connect_reject(chan);
746 }
747
748 l2cap_chan_del(chan, reason);
749 break;
750
751 case BT_CONNECT:
752 case BT_DISCONN:
753 l2cap_chan_del(chan, reason);
754 break;
755
756 default:
757 chan->ops->teardown(chan, 0);
758 break;
759 }
760 }
761 EXPORT_SYMBOL(l2cap_chan_close);
762
763 static inline u8 l2cap_get_auth_type(struct l2cap_chan *chan)
764 {
765 switch (chan->chan_type) {
766 case L2CAP_CHAN_RAW:
767 switch (chan->sec_level) {
768 case BT_SECURITY_HIGH:
769 case BT_SECURITY_FIPS:
770 return HCI_AT_DEDICATED_BONDING_MITM;
771 case BT_SECURITY_MEDIUM:
772 return HCI_AT_DEDICATED_BONDING;
773 default:
774 return HCI_AT_NO_BONDING;
775 }
776 break;
777 case L2CAP_CHAN_CONN_LESS:
778 if (chan->psm == cpu_to_le16(L2CAP_PSM_3DSP)) {
779 if (chan->sec_level == BT_SECURITY_LOW)
780 chan->sec_level = BT_SECURITY_SDP;
781 }
782 if (chan->sec_level == BT_SECURITY_HIGH ||
783 chan->sec_level == BT_SECURITY_FIPS)
784 return HCI_AT_NO_BONDING_MITM;
785 else
786 return HCI_AT_NO_BONDING;
787 break;
788 case L2CAP_CHAN_CONN_ORIENTED:
789 if (chan->psm == cpu_to_le16(L2CAP_PSM_SDP)) {
790 if (chan->sec_level == BT_SECURITY_LOW)
791 chan->sec_level = BT_SECURITY_SDP;
792
793 if (chan->sec_level == BT_SECURITY_HIGH ||
794 chan->sec_level == BT_SECURITY_FIPS)
795 return HCI_AT_NO_BONDING_MITM;
796 else
797 return HCI_AT_NO_BONDING;
798 }
799 /* fall through */
800 default:
801 switch (chan->sec_level) {
802 case BT_SECURITY_HIGH:
803 case BT_SECURITY_FIPS:
804 return HCI_AT_GENERAL_BONDING_MITM;
805 case BT_SECURITY_MEDIUM:
806 return HCI_AT_GENERAL_BONDING;
807 default:
808 return HCI_AT_NO_BONDING;
809 }
810 break;
811 }
812 }
813
814 /* Service level security */
815 int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator)
816 {
817 struct l2cap_conn *conn = chan->conn;
818 __u8 auth_type;
819
820 if (conn->hcon->type == LE_LINK)
821 return smp_conn_security(conn->hcon, chan->sec_level);
822
823 auth_type = l2cap_get_auth_type(chan);
824
825 return hci_conn_security(conn->hcon, chan->sec_level, auth_type,
826 initiator);
827 }
828
829 static u8 l2cap_get_ident(struct l2cap_conn *conn)
830 {
831 u8 id;
832
833 /* Get next available identificator.
834 * 1 - 128 are used by kernel.
835 * 129 - 199 are reserved.
836 * 200 - 254 are used by utilities like l2ping, etc.
837 */
838
839 mutex_lock(&conn->ident_lock);
840
841 if (++conn->tx_ident > 128)
842 conn->tx_ident = 1;
843
844 id = conn->tx_ident;
845
846 mutex_unlock(&conn->ident_lock);
847
848 return id;
849 }
850
851 static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
852 void *data)
853 {
854 struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data);
855 u8 flags;
856
857 BT_DBG("code 0x%2.2x", code);
858
859 if (!skb)
860 return;
861
862 /* Use NO_FLUSH if supported or we have an LE link (which does
863 * not support auto-flushing packets) */
864 if (lmp_no_flush_capable(conn->hcon->hdev) ||
865 conn->hcon->type == LE_LINK)
866 flags = ACL_START_NO_FLUSH;
867 else
868 flags = ACL_START;
869
870 bt_cb(skb)->force_active = BT_POWER_FORCE_ACTIVE_ON;
871 skb->priority = HCI_PRIO_MAX;
872
873 hci_send_acl(conn->hchan, skb, flags);
874 }
875
876 static bool __chan_is_moving(struct l2cap_chan *chan)
877 {
878 return chan->move_state != L2CAP_MOVE_STABLE &&
879 chan->move_state != L2CAP_MOVE_WAIT_PREPARE;
880 }
881
882 static void l2cap_do_send(struct l2cap_chan *chan, struct sk_buff *skb)
883 {
884 struct hci_conn *hcon = chan->conn->hcon;
885 u16 flags;
886
887 BT_DBG("chan %p, skb %p len %d priority %u", chan, skb, skb->len,
888 skb->priority);
889
890 if (chan->hs_hcon && !__chan_is_moving(chan)) {
891 if (chan->hs_hchan)
892 hci_send_acl(chan->hs_hchan, skb, ACL_COMPLETE);
893 else
894 kfree_skb(skb);
895
896 return;
897 }
898
899 /* Use NO_FLUSH for LE links (where this is the only option) or
900 * if the BR/EDR link supports it and flushing has not been
901 * explicitly requested (through FLAG_FLUSHABLE).
902 */
903 if (hcon->type == LE_LINK ||
904 (!test_bit(FLAG_FLUSHABLE, &chan->flags) &&
905 lmp_no_flush_capable(hcon->hdev)))
906 flags = ACL_START_NO_FLUSH;
907 else
908 flags = ACL_START;
909
910 bt_cb(skb)->force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags);
911 hci_send_acl(chan->conn->hchan, skb, flags);
912 }
913
914 static void __unpack_enhanced_control(u16 enh, struct l2cap_ctrl *control)
915 {
916 control->reqseq = (enh & L2CAP_CTRL_REQSEQ) >> L2CAP_CTRL_REQSEQ_SHIFT;
917 control->final = (enh & L2CAP_CTRL_FINAL) >> L2CAP_CTRL_FINAL_SHIFT;
918
919 if (enh & L2CAP_CTRL_FRAME_TYPE) {
920 /* S-Frame */
921 control->sframe = 1;
922 control->poll = (enh & L2CAP_CTRL_POLL) >> L2CAP_CTRL_POLL_SHIFT;
923 control->super = (enh & L2CAP_CTRL_SUPERVISE) >> L2CAP_CTRL_SUPER_SHIFT;
924
925 control->sar = 0;
926 control->txseq = 0;
927 } else {
928 /* I-Frame */
929 control->sframe = 0;
930 control->sar = (enh & L2CAP_CTRL_SAR) >> L2CAP_CTRL_SAR_SHIFT;
931 control->txseq = (enh & L2CAP_CTRL_TXSEQ) >> L2CAP_CTRL_TXSEQ_SHIFT;
932
933 control->poll = 0;
934 control->super = 0;
935 }
936 }
937
938 static void __unpack_extended_control(u32 ext, struct l2cap_ctrl *control)
939 {
940 control->reqseq = (ext & L2CAP_EXT_CTRL_REQSEQ) >> L2CAP_EXT_CTRL_REQSEQ_SHIFT;
941 control->final = (ext & L2CAP_EXT_CTRL_FINAL) >> L2CAP_EXT_CTRL_FINAL_SHIFT;
942
943 if (ext & L2CAP_EXT_CTRL_FRAME_TYPE) {
944 /* S-Frame */
945 control->sframe = 1;
946 control->poll = (ext & L2CAP_EXT_CTRL_POLL) >> L2CAP_EXT_CTRL_POLL_SHIFT;
947 control->super = (ext & L2CAP_EXT_CTRL_SUPERVISE) >> L2CAP_EXT_CTRL_SUPER_SHIFT;
948
949 control->sar = 0;
950 control->txseq = 0;
951 } else {
952 /* I-Frame */
953 control->sframe = 0;
954 control->sar = (ext & L2CAP_EXT_CTRL_SAR) >> L2CAP_EXT_CTRL_SAR_SHIFT;
955 control->txseq = (ext & L2CAP_EXT_CTRL_TXSEQ) >> L2CAP_EXT_CTRL_TXSEQ_SHIFT;
956
957 control->poll = 0;
958 control->super = 0;
959 }
960 }
961
962 static inline void __unpack_control(struct l2cap_chan *chan,
963 struct sk_buff *skb)
964 {
965 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
966 __unpack_extended_control(get_unaligned_le32(skb->data),
967 &bt_cb(skb)->l2cap);
968 skb_pull(skb, L2CAP_EXT_CTRL_SIZE);
969 } else {
970 __unpack_enhanced_control(get_unaligned_le16(skb->data),
971 &bt_cb(skb)->l2cap);
972 skb_pull(skb, L2CAP_ENH_CTRL_SIZE);
973 }
974 }
975
976 static u32 __pack_extended_control(struct l2cap_ctrl *control)
977 {
978 u32 packed;
979
980 packed = control->reqseq << L2CAP_EXT_CTRL_REQSEQ_SHIFT;
981 packed |= control->final << L2CAP_EXT_CTRL_FINAL_SHIFT;
982
983 if (control->sframe) {
984 packed |= control->poll << L2CAP_EXT_CTRL_POLL_SHIFT;
985 packed |= control->super << L2CAP_EXT_CTRL_SUPER_SHIFT;
986 packed |= L2CAP_EXT_CTRL_FRAME_TYPE;
987 } else {
988 packed |= control->sar << L2CAP_EXT_CTRL_SAR_SHIFT;
989 packed |= control->txseq << L2CAP_EXT_CTRL_TXSEQ_SHIFT;
990 }
991
992 return packed;
993 }
994
995 static u16 __pack_enhanced_control(struct l2cap_ctrl *control)
996 {
997 u16 packed;
998
999 packed = control->reqseq << L2CAP_CTRL_REQSEQ_SHIFT;
1000 packed |= control->final << L2CAP_CTRL_FINAL_SHIFT;
1001
1002 if (control->sframe) {
1003 packed |= control->poll << L2CAP_CTRL_POLL_SHIFT;
1004 packed |= control->super << L2CAP_CTRL_SUPER_SHIFT;
1005 packed |= L2CAP_CTRL_FRAME_TYPE;
1006 } else {
1007 packed |= control->sar << L2CAP_CTRL_SAR_SHIFT;
1008 packed |= control->txseq << L2CAP_CTRL_TXSEQ_SHIFT;
1009 }
1010
1011 return packed;
1012 }
1013
1014 static inline void __pack_control(struct l2cap_chan *chan,
1015 struct l2cap_ctrl *control,
1016 struct sk_buff *skb)
1017 {
1018 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
1019 put_unaligned_le32(__pack_extended_control(control),
1020 skb->data + L2CAP_HDR_SIZE);
1021 } else {
1022 put_unaligned_le16(__pack_enhanced_control(control),
1023 skb->data + L2CAP_HDR_SIZE);
1024 }
1025 }
1026
1027 static inline unsigned int __ertm_hdr_size(struct l2cap_chan *chan)
1028 {
1029 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1030 return L2CAP_EXT_HDR_SIZE;
1031 else
1032 return L2CAP_ENH_HDR_SIZE;
1033 }
1034
1035 static struct sk_buff *l2cap_create_sframe_pdu(struct l2cap_chan *chan,
1036 u32 control)
1037 {
1038 struct sk_buff *skb;
1039 struct l2cap_hdr *lh;
1040 int hlen = __ertm_hdr_size(chan);
1041
1042 if (chan->fcs == L2CAP_FCS_CRC16)
1043 hlen += L2CAP_FCS_SIZE;
1044
1045 skb = bt_skb_alloc(hlen, GFP_KERNEL);
1046
1047 if (!skb)
1048 return ERR_PTR(-ENOMEM);
1049
1050 lh = skb_put(skb, L2CAP_HDR_SIZE);
1051 lh->len = cpu_to_le16(hlen - L2CAP_HDR_SIZE);
1052 lh->cid = cpu_to_le16(chan->dcid);
1053
1054 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1055 put_unaligned_le32(control, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
1056 else
1057 put_unaligned_le16(control, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
1058
1059 if (chan->fcs == L2CAP_FCS_CRC16) {
1060 u16 fcs = crc16(0, (u8 *)skb->data, skb->len);
1061 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1062 }
1063
1064 skb->priority = HCI_PRIO_MAX;
1065 return skb;
1066 }
1067
1068 static void l2cap_send_sframe(struct l2cap_chan *chan,
1069 struct l2cap_ctrl *control)
1070 {
1071 struct sk_buff *skb;
1072 u32 control_field;
1073
1074 BT_DBG("chan %p, control %p", chan, control);
1075
1076 if (!control->sframe)
1077 return;
1078
1079 if (__chan_is_moving(chan))
1080 return;
1081
1082 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state) &&
1083 !control->poll)
1084 control->final = 1;
1085
1086 if (control->super == L2CAP_SUPER_RR)
1087 clear_bit(CONN_RNR_SENT, &chan->conn_state);
1088 else if (control->super == L2CAP_SUPER_RNR)
1089 set_bit(CONN_RNR_SENT, &chan->conn_state);
1090
1091 if (control->super != L2CAP_SUPER_SREJ) {
1092 chan->last_acked_seq = control->reqseq;
1093 __clear_ack_timer(chan);
1094 }
1095
1096 BT_DBG("reqseq %d, final %d, poll %d, super %d", control->reqseq,
1097 control->final, control->poll, control->super);
1098
1099 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1100 control_field = __pack_extended_control(control);
1101 else
1102 control_field = __pack_enhanced_control(control);
1103
1104 skb = l2cap_create_sframe_pdu(chan, control_field);
1105 if (!IS_ERR(skb))
1106 l2cap_do_send(chan, skb);
1107 }
1108
1109 static void l2cap_send_rr_or_rnr(struct l2cap_chan *chan, bool poll)
1110 {
1111 struct l2cap_ctrl control;
1112
1113 BT_DBG("chan %p, poll %d", chan, poll);
1114
1115 memset(&control, 0, sizeof(control));
1116 control.sframe = 1;
1117 control.poll = poll;
1118
1119 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
1120 control.super = L2CAP_SUPER_RNR;
1121 else
1122 control.super = L2CAP_SUPER_RR;
1123
1124 control.reqseq = chan->buffer_seq;
1125 l2cap_send_sframe(chan, &control);
1126 }
1127
1128 static inline int __l2cap_no_conn_pending(struct l2cap_chan *chan)
1129 {
1130 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
1131 return true;
1132
1133 return !test_bit(CONF_CONNECT_PEND, &chan->conf_state);
1134 }
1135
1136 static bool __amp_capable(struct l2cap_chan *chan)
1137 {
1138 struct l2cap_conn *conn = chan->conn;
1139 struct hci_dev *hdev;
1140 bool amp_available = false;
1141
1142 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
1143 return false;
1144
1145 if (!(conn->remote_fixed_chan & L2CAP_FC_A2MP))
1146 return false;
1147
1148 read_lock(&hci_dev_list_lock);
1149 list_for_each_entry(hdev, &hci_dev_list, list) {
1150 if (hdev->amp_type != AMP_TYPE_BREDR &&
1151 test_bit(HCI_UP, &hdev->flags)) {
1152 amp_available = true;
1153 break;
1154 }
1155 }
1156 read_unlock(&hci_dev_list_lock);
1157
1158 if (chan->chan_policy == BT_CHANNEL_POLICY_AMP_PREFERRED)
1159 return amp_available;
1160
1161 return false;
1162 }
1163
1164 static bool l2cap_check_efs(struct l2cap_chan *chan)
1165 {
1166 /* Check EFS parameters */
1167 return true;
1168 }
1169
1170 void l2cap_send_conn_req(struct l2cap_chan *chan)
1171 {
1172 struct l2cap_conn *conn = chan->conn;
1173 struct l2cap_conn_req req;
1174
1175 req.scid = cpu_to_le16(chan->scid);
1176 req.psm = chan->psm;
1177
1178 chan->ident = l2cap_get_ident(conn);
1179
1180 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
1181
1182 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_REQ, sizeof(req), &req);
1183 }
1184
1185 static void l2cap_send_create_chan_req(struct l2cap_chan *chan, u8 amp_id)
1186 {
1187 struct l2cap_create_chan_req req;
1188 req.scid = cpu_to_le16(chan->scid);
1189 req.psm = chan->psm;
1190 req.amp_id = amp_id;
1191
1192 chan->ident = l2cap_get_ident(chan->conn);
1193
1194 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_REQ,
1195 sizeof(req), &req);
1196 }
1197
1198 static void l2cap_move_setup(struct l2cap_chan *chan)
1199 {
1200 struct sk_buff *skb;
1201
1202 BT_DBG("chan %p", chan);
1203
1204 if (chan->mode != L2CAP_MODE_ERTM)
1205 return;
1206
1207 __clear_retrans_timer(chan);
1208 __clear_monitor_timer(chan);
1209 __clear_ack_timer(chan);
1210
1211 chan->retry_count = 0;
1212 skb_queue_walk(&chan->tx_q, skb) {
1213 if (bt_cb(skb)->l2cap.retries)
1214 bt_cb(skb)->l2cap.retries = 1;
1215 else
1216 break;
1217 }
1218
1219 chan->expected_tx_seq = chan->buffer_seq;
1220
1221 clear_bit(CONN_REJ_ACT, &chan->conn_state);
1222 clear_bit(CONN_SREJ_ACT, &chan->conn_state);
1223 l2cap_seq_list_clear(&chan->retrans_list);
1224 l2cap_seq_list_clear(&chan->srej_list);
1225 skb_queue_purge(&chan->srej_q);
1226
1227 chan->tx_state = L2CAP_TX_STATE_XMIT;
1228 chan->rx_state = L2CAP_RX_STATE_MOVE;
1229
1230 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
1231 }
1232
1233 static void l2cap_move_done(struct l2cap_chan *chan)
1234 {
1235 u8 move_role = chan->move_role;
1236 BT_DBG("chan %p", chan);
1237
1238 chan->move_state = L2CAP_MOVE_STABLE;
1239 chan->move_role = L2CAP_MOVE_ROLE_NONE;
1240
1241 if (chan->mode != L2CAP_MODE_ERTM)
1242 return;
1243
1244 switch (move_role) {
1245 case L2CAP_MOVE_ROLE_INITIATOR:
1246 l2cap_tx(chan, NULL, NULL, L2CAP_EV_EXPLICIT_POLL);
1247 chan->rx_state = L2CAP_RX_STATE_WAIT_F;
1248 break;
1249 case L2CAP_MOVE_ROLE_RESPONDER:
1250 chan->rx_state = L2CAP_RX_STATE_WAIT_P;
1251 break;
1252 }
1253 }
1254
1255 static void l2cap_chan_ready(struct l2cap_chan *chan)
1256 {
1257 /* The channel may have already been flagged as connected in
1258 * case of receiving data before the L2CAP info req/rsp
1259 * procedure is complete.
1260 */
1261 if (chan->state == BT_CONNECTED)
1262 return;
1263
1264 /* This clears all conf flags, including CONF_NOT_COMPLETE */
1265 chan->conf_state = 0;
1266 __clear_chan_timer(chan);
1267
1268 if (chan->mode == L2CAP_MODE_LE_FLOWCTL && !chan->tx_credits)
1269 chan->ops->suspend(chan);
1270
1271 chan->state = BT_CONNECTED;
1272
1273 chan->ops->ready(chan);
1274 }
1275
1276 static void l2cap_le_connect(struct l2cap_chan *chan)
1277 {
1278 struct l2cap_conn *conn = chan->conn;
1279 struct l2cap_le_conn_req req;
1280
1281 if (test_and_set_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags))
1282 return;
1283
1284 l2cap_le_flowctl_init(chan, 0);
1285
1286 req.psm = chan->psm;
1287 req.scid = cpu_to_le16(chan->scid);
1288 req.mtu = cpu_to_le16(chan->imtu);
1289 req.mps = cpu_to_le16(chan->mps);
1290 req.credits = cpu_to_le16(chan->rx_credits);
1291
1292 chan->ident = l2cap_get_ident(conn);
1293
1294 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_REQ,
1295 sizeof(req), &req);
1296 }
1297
1298 static void l2cap_le_start(struct l2cap_chan *chan)
1299 {
1300 struct l2cap_conn *conn = chan->conn;
1301
1302 if (!smp_conn_security(conn->hcon, chan->sec_level))
1303 return;
1304
1305 if (!chan->psm) {
1306 l2cap_chan_ready(chan);
1307 return;
1308 }
1309
1310 if (chan->state == BT_CONNECT)
1311 l2cap_le_connect(chan);
1312 }
1313
1314 static void l2cap_start_connection(struct l2cap_chan *chan)
1315 {
1316 if (__amp_capable(chan)) {
1317 BT_DBG("chan %p AMP capable: discover AMPs", chan);
1318 a2mp_discover_amp(chan);
1319 } else if (chan->conn->hcon->type == LE_LINK) {
1320 l2cap_le_start(chan);
1321 } else {
1322 l2cap_send_conn_req(chan);
1323 }
1324 }
1325
1326 static void l2cap_request_info(struct l2cap_conn *conn)
1327 {
1328 struct l2cap_info_req req;
1329
1330 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1331 return;
1332
1333 req.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
1334
1335 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
1336 conn->info_ident = l2cap_get_ident(conn);
1337
1338 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
1339
1340 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
1341 sizeof(req), &req);
1342 }
1343
1344 static void l2cap_do_start(struct l2cap_chan *chan)
1345 {
1346 struct l2cap_conn *conn = chan->conn;
1347
1348 if (conn->hcon->type == LE_LINK) {
1349 l2cap_le_start(chan);
1350 return;
1351 }
1352
1353 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)) {
1354 l2cap_request_info(conn);
1355 return;
1356 }
1357
1358 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE))
1359 return;
1360
1361 if (l2cap_chan_check_security(chan, true) &&
1362 __l2cap_no_conn_pending(chan))
1363 l2cap_start_connection(chan);
1364 }
1365
1366 static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
1367 {
1368 u32 local_feat_mask = l2cap_feat_mask;
1369 if (!disable_ertm)
1370 local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
1371
1372 switch (mode) {
1373 case L2CAP_MODE_ERTM:
1374 return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
1375 case L2CAP_MODE_STREAMING:
1376 return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
1377 default:
1378 return 0x00;
1379 }
1380 }
1381
1382 static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err)
1383 {
1384 struct l2cap_conn *conn = chan->conn;
1385 struct l2cap_disconn_req req;
1386
1387 if (!conn)
1388 return;
1389
1390 if (chan->mode == L2CAP_MODE_ERTM && chan->state == BT_CONNECTED) {
1391 __clear_retrans_timer(chan);
1392 __clear_monitor_timer(chan);
1393 __clear_ack_timer(chan);
1394 }
1395
1396 if (chan->scid == L2CAP_CID_A2MP) {
1397 l2cap_state_change(chan, BT_DISCONN);
1398 return;
1399 }
1400
1401 req.dcid = cpu_to_le16(chan->dcid);
1402 req.scid = cpu_to_le16(chan->scid);
1403 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_DISCONN_REQ,
1404 sizeof(req), &req);
1405
1406 l2cap_state_change_and_error(chan, BT_DISCONN, err);
1407 }
1408
1409 /* ---- L2CAP connections ---- */
1410 static void l2cap_conn_start(struct l2cap_conn *conn)
1411 {
1412 struct l2cap_chan *chan, *tmp;
1413
1414 BT_DBG("conn %p", conn);
1415
1416 mutex_lock(&conn->chan_lock);
1417
1418 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
1419 l2cap_chan_lock(chan);
1420
1421 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1422 l2cap_chan_ready(chan);
1423 l2cap_chan_unlock(chan);
1424 continue;
1425 }
1426
1427 if (chan->state == BT_CONNECT) {
1428 if (!l2cap_chan_check_security(chan, true) ||
1429 !__l2cap_no_conn_pending(chan)) {
1430 l2cap_chan_unlock(chan);
1431 continue;
1432 }
1433
1434 if (!l2cap_mode_supported(chan->mode, conn->feat_mask)
1435 && test_bit(CONF_STATE2_DEVICE,
1436 &chan->conf_state)) {
1437 l2cap_chan_close(chan, ECONNRESET);
1438 l2cap_chan_unlock(chan);
1439 continue;
1440 }
1441
1442 l2cap_start_connection(chan);
1443
1444 } else if (chan->state == BT_CONNECT2) {
1445 struct l2cap_conn_rsp rsp;
1446 char buf[128];
1447 rsp.scid = cpu_to_le16(chan->dcid);
1448 rsp.dcid = cpu_to_le16(chan->scid);
1449
1450 if (l2cap_chan_check_security(chan, false)) {
1451 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
1452 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1453 rsp.status = cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
1454 chan->ops->defer(chan);
1455
1456 } else {
1457 l2cap_state_change(chan, BT_CONFIG);
1458 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
1459 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
1460 }
1461 } else {
1462 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1463 rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
1464 }
1465
1466 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
1467 sizeof(rsp), &rsp);
1468
1469 if (test_bit(CONF_REQ_SENT, &chan->conf_state) ||
1470 rsp.result != L2CAP_CR_SUCCESS) {
1471 l2cap_chan_unlock(chan);
1472 continue;
1473 }
1474
1475 set_bit(CONF_REQ_SENT, &chan->conf_state);
1476 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
1477 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
1478 chan->num_conf_req++;
1479 }
1480
1481 l2cap_chan_unlock(chan);
1482 }
1483
1484 mutex_unlock(&conn->chan_lock);
1485 }
1486
1487 static void l2cap_le_conn_ready(struct l2cap_conn *conn)
1488 {
1489 struct hci_conn *hcon = conn->hcon;
1490 struct hci_dev *hdev = hcon->hdev;
1491
1492 BT_DBG("%s conn %p", hdev->name, conn);
1493
1494 /* For outgoing pairing which doesn't necessarily have an
1495 * associated socket (e.g. mgmt_pair_device).
1496 */
1497 if (hcon->out)
1498 smp_conn_security(hcon, hcon->pending_sec_level);
1499
1500 /* For LE slave connections, make sure the connection interval
1501 * is in the range of the minium and maximum interval that has
1502 * been configured for this connection. If not, then trigger
1503 * the connection update procedure.
1504 */
1505 if (hcon->role == HCI_ROLE_SLAVE &&
1506 (hcon->le_conn_interval < hcon->le_conn_min_interval ||
1507 hcon->le_conn_interval > hcon->le_conn_max_interval)) {
1508 struct l2cap_conn_param_update_req req;
1509
1510 req.min = cpu_to_le16(hcon->le_conn_min_interval);
1511 req.max = cpu_to_le16(hcon->le_conn_max_interval);
1512 req.latency = cpu_to_le16(hcon->le_conn_latency);
1513 req.to_multiplier = cpu_to_le16(hcon->le_supv_timeout);
1514
1515 l2cap_send_cmd(conn, l2cap_get_ident(conn),
1516 L2CAP_CONN_PARAM_UPDATE_REQ, sizeof(req), &req);
1517 }
1518 }
1519
1520 static void l2cap_conn_ready(struct l2cap_conn *conn)
1521 {
1522 struct l2cap_chan *chan;
1523 struct hci_conn *hcon = conn->hcon;
1524
1525 BT_DBG("conn %p", conn);
1526
1527 if (hcon->type == ACL_LINK)
1528 l2cap_request_info(conn);
1529
1530 mutex_lock(&conn->chan_lock);
1531
1532 list_for_each_entry(chan, &conn->chan_l, list) {
1533
1534 l2cap_chan_lock(chan);
1535
1536 if (chan->scid == L2CAP_CID_A2MP) {
1537 l2cap_chan_unlock(chan);
1538 continue;
1539 }
1540
1541 if (hcon->type == LE_LINK) {
1542 l2cap_le_start(chan);
1543 } else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1544 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
1545 l2cap_chan_ready(chan);
1546 } else if (chan->state == BT_CONNECT) {
1547 l2cap_do_start(chan);
1548 }
1549
1550 l2cap_chan_unlock(chan);
1551 }
1552
1553 mutex_unlock(&conn->chan_lock);
1554
1555 if (hcon->type == LE_LINK)
1556 l2cap_le_conn_ready(conn);
1557
1558 queue_work(hcon->hdev->workqueue, &conn->pending_rx_work);
1559 }
1560
1561 /* Notify sockets that we cannot guaranty reliability anymore */
1562 static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
1563 {
1564 struct l2cap_chan *chan;
1565
1566 BT_DBG("conn %p", conn);
1567
1568 mutex_lock(&conn->chan_lock);
1569
1570 list_for_each_entry(chan, &conn->chan_l, list) {
1571 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
1572 l2cap_chan_set_err(chan, err);
1573 }
1574
1575 mutex_unlock(&conn->chan_lock);
1576 }
1577
1578 static void l2cap_info_timeout(struct work_struct *work)
1579 {
1580 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
1581 info_timer.work);
1582
1583 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
1584 conn->info_ident = 0;
1585
1586 l2cap_conn_start(conn);
1587 }
1588
1589 /*
1590 * l2cap_user
1591 * External modules can register l2cap_user objects on l2cap_conn. The ->probe
1592 * callback is called during registration. The ->remove callback is called
1593 * during unregistration.
1594 * An l2cap_user object can either be explicitly unregistered or when the
1595 * underlying l2cap_conn object is deleted. This guarantees that l2cap->hcon,
1596 * l2cap->hchan, .. are valid as long as the remove callback hasn't been called.
1597 * External modules must own a reference to the l2cap_conn object if they intend
1598 * to call l2cap_unregister_user(). The l2cap_conn object might get destroyed at
1599 * any time if they don't.
1600 */
1601
1602 int l2cap_register_user(struct l2cap_conn *conn, struct l2cap_user *user)
1603 {
1604 struct hci_dev *hdev = conn->hcon->hdev;
1605 int ret;
1606
1607 /* We need to check whether l2cap_conn is registered. If it is not, we
1608 * must not register the l2cap_user. l2cap_conn_del() is unregisters
1609 * l2cap_conn objects, but doesn't provide its own locking. Instead, it
1610 * relies on the parent hci_conn object to be locked. This itself relies
1611 * on the hci_dev object to be locked. So we must lock the hci device
1612 * here, too. */
1613
1614 hci_dev_lock(hdev);
1615
1616 if (!list_empty(&user->list)) {
1617 ret = -EINVAL;
1618 goto out_unlock;
1619 }
1620
1621 /* conn->hchan is NULL after l2cap_conn_del() was called */
1622 if (!conn->hchan) {
1623 ret = -ENODEV;
1624 goto out_unlock;
1625 }
1626
1627 ret = user->probe(conn, user);
1628 if (ret)
1629 goto out_unlock;
1630
1631 list_add(&user->list, &conn->users);
1632 ret = 0;
1633
1634 out_unlock:
1635 hci_dev_unlock(hdev);
1636 return ret;
1637 }
1638 EXPORT_SYMBOL(l2cap_register_user);
1639
1640 void l2cap_unregister_user(struct l2cap_conn *conn, struct l2cap_user *user)
1641 {
1642 struct hci_dev *hdev = conn->hcon->hdev;
1643
1644 hci_dev_lock(hdev);
1645
1646 if (list_empty(&user->list))
1647 goto out_unlock;
1648
1649 list_del_init(&user->list);
1650 user->remove(conn, user);
1651
1652 out_unlock:
1653 hci_dev_unlock(hdev);
1654 }
1655 EXPORT_SYMBOL(l2cap_unregister_user);
1656
1657 static void l2cap_unregister_all_users(struct l2cap_conn *conn)
1658 {
1659 struct l2cap_user *user;
1660
1661 while (!list_empty(&conn->users)) {
1662 user = list_first_entry(&conn->users, struct l2cap_user, list);
1663 list_del_init(&user->list);
1664 user->remove(conn, user);
1665 }
1666 }
1667
1668 static void l2cap_conn_del(struct hci_conn *hcon, int err)
1669 {
1670 struct l2cap_conn *conn = hcon->l2cap_data;
1671 struct l2cap_chan *chan, *l;
1672
1673 if (!conn)
1674 return;
1675
1676 BT_DBG("hcon %p conn %p, err %d", hcon, conn, err);
1677
1678 kfree_skb(conn->rx_skb);
1679
1680 skb_queue_purge(&conn->pending_rx);
1681
1682 /* We can not call flush_work(&conn->pending_rx_work) here since we
1683 * might block if we are running on a worker from the same workqueue
1684 * pending_rx_work is waiting on.
1685 */
1686 if (work_pending(&conn->pending_rx_work))
1687 cancel_work_sync(&conn->pending_rx_work);
1688
1689 if (work_pending(&conn->id_addr_update_work))
1690 cancel_work_sync(&conn->id_addr_update_work);
1691
1692 l2cap_unregister_all_users(conn);
1693
1694 /* Force the connection to be immediately dropped */
1695 hcon->disc_timeout = 0;
1696
1697 mutex_lock(&conn->chan_lock);
1698
1699 /* Kill channels */
1700 list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
1701 l2cap_chan_hold(chan);
1702 l2cap_chan_lock(chan);
1703
1704 l2cap_chan_del(chan, err);
1705
1706 l2cap_chan_unlock(chan);
1707
1708 chan->ops->close(chan);
1709 l2cap_chan_put(chan);
1710 }
1711
1712 mutex_unlock(&conn->chan_lock);
1713
1714 hci_chan_del(conn->hchan);
1715
1716 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1717 cancel_delayed_work_sync(&conn->info_timer);
1718
1719 hcon->l2cap_data = NULL;
1720 conn->hchan = NULL;
1721 l2cap_conn_put(conn);
1722 }
1723
1724 static void l2cap_conn_free(struct kref *ref)
1725 {
1726 struct l2cap_conn *conn = container_of(ref, struct l2cap_conn, ref);
1727
1728 hci_conn_put(conn->hcon);
1729 kfree(conn);
1730 }
1731
1732 struct l2cap_conn *l2cap_conn_get(struct l2cap_conn *conn)
1733 {
1734 kref_get(&conn->ref);
1735 return conn;
1736 }
1737 EXPORT_SYMBOL(l2cap_conn_get);
1738
1739 void l2cap_conn_put(struct l2cap_conn *conn)
1740 {
1741 kref_put(&conn->ref, l2cap_conn_free);
1742 }
1743 EXPORT_SYMBOL(l2cap_conn_put);
1744
1745 /* ---- Socket interface ---- */
1746
1747 /* Find socket with psm and source / destination bdaddr.
1748 * Returns closest match.
1749 */
1750 static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
1751 bdaddr_t *src,
1752 bdaddr_t *dst,
1753 u8 link_type)
1754 {
1755 struct l2cap_chan *c, *c1 = NULL;
1756
1757 read_lock(&chan_list_lock);
1758
1759 list_for_each_entry(c, &chan_list, global_l) {
1760 if (state && c->state != state)
1761 continue;
1762
1763 if (link_type == ACL_LINK && c->src_type != BDADDR_BREDR)
1764 continue;
1765
1766 if (link_type == LE_LINK && c->src_type == BDADDR_BREDR)
1767 continue;
1768
1769 if (c->psm == psm) {
1770 int src_match, dst_match;
1771 int src_any, dst_any;
1772
1773 /* Exact match. */
1774 src_match = !bacmp(&c->src, src);
1775 dst_match = !bacmp(&c->dst, dst);
1776 if (src_match && dst_match) {
1777 l2cap_chan_hold(c);
1778 read_unlock(&chan_list_lock);
1779 return c;
1780 }
1781
1782 /* Closest match */
1783 src_any = !bacmp(&c->src, BDADDR_ANY);
1784 dst_any = !bacmp(&c->dst, BDADDR_ANY);
1785 if ((src_match && dst_any) || (src_any && dst_match) ||
1786 (src_any && dst_any))
1787 c1 = c;
1788 }
1789 }
1790
1791 if (c1)
1792 l2cap_chan_hold(c1);
1793
1794 read_unlock(&chan_list_lock);
1795
1796 return c1;
1797 }
1798
1799 static void l2cap_monitor_timeout(struct work_struct *work)
1800 {
1801 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
1802 monitor_timer.work);
1803
1804 BT_DBG("chan %p", chan);
1805
1806 l2cap_chan_lock(chan);
1807
1808 if (!chan->conn) {
1809 l2cap_chan_unlock(chan);
1810 l2cap_chan_put(chan);
1811 return;
1812 }
1813
1814 l2cap_tx(chan, NULL, NULL, L2CAP_EV_MONITOR_TO);
1815
1816 l2cap_chan_unlock(chan);
1817 l2cap_chan_put(chan);
1818 }
1819
1820 static void l2cap_retrans_timeout(struct work_struct *work)
1821 {
1822 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
1823 retrans_timer.work);
1824
1825 BT_DBG("chan %p", chan);
1826
1827 l2cap_chan_lock(chan);
1828
1829 if (!chan->conn) {
1830 l2cap_chan_unlock(chan);
1831 l2cap_chan_put(chan);
1832 return;
1833 }
1834
1835 l2cap_tx(chan, NULL, NULL, L2CAP_EV_RETRANS_TO);
1836 l2cap_chan_unlock(chan);
1837 l2cap_chan_put(chan);
1838 }
1839
1840 static void l2cap_streaming_send(struct l2cap_chan *chan,
1841 struct sk_buff_head *skbs)
1842 {
1843 struct sk_buff *skb;
1844 struct l2cap_ctrl *control;
1845
1846 BT_DBG("chan %p, skbs %p", chan, skbs);
1847
1848 if (__chan_is_moving(chan))
1849 return;
1850
1851 skb_queue_splice_tail_init(skbs, &chan->tx_q);
1852
1853 while (!skb_queue_empty(&chan->tx_q)) {
1854
1855 skb = skb_dequeue(&chan->tx_q);
1856
1857 bt_cb(skb)->l2cap.retries = 1;
1858 control = &bt_cb(skb)->l2cap;
1859
1860 control->reqseq = 0;
1861 control->txseq = chan->next_tx_seq;
1862
1863 __pack_control(chan, control, skb);
1864
1865 if (chan->fcs == L2CAP_FCS_CRC16) {
1866 u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
1867 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1868 }
1869
1870 l2cap_do_send(chan, skb);
1871
1872 BT_DBG("Sent txseq %u", control->txseq);
1873
1874 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
1875 chan->frames_sent++;
1876 }
1877 }
1878
1879 static int l2cap_ertm_send(struct l2cap_chan *chan)
1880 {
1881 struct sk_buff *skb, *tx_skb;
1882 struct l2cap_ctrl *control;
1883 int sent = 0;
1884
1885 BT_DBG("chan %p", chan);
1886
1887 if (chan->state != BT_CONNECTED)
1888 return -ENOTCONN;
1889
1890 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
1891 return 0;
1892
1893 if (__chan_is_moving(chan))
1894 return 0;
1895
1896 while (chan->tx_send_head &&
1897 chan->unacked_frames < chan->remote_tx_win &&
1898 chan->tx_state == L2CAP_TX_STATE_XMIT) {
1899
1900 skb = chan->tx_send_head;
1901
1902 bt_cb(skb)->l2cap.retries = 1;
1903 control = &bt_cb(skb)->l2cap;
1904
1905 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
1906 control->final = 1;
1907
1908 control->reqseq = chan->buffer_seq;
1909 chan->last_acked_seq = chan->buffer_seq;
1910 control->txseq = chan->next_tx_seq;
1911
1912 __pack_control(chan, control, skb);
1913
1914 if (chan->fcs == L2CAP_FCS_CRC16) {
1915 u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
1916 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1917 }
1918
1919 /* Clone after data has been modified. Data is assumed to be
1920 read-only (for locking purposes) on cloned sk_buffs.
1921 */
1922 tx_skb = skb_clone(skb, GFP_KERNEL);
1923
1924 if (!tx_skb)
1925 break;
1926
1927 __set_retrans_timer(chan);
1928
1929 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
1930 chan->unacked_frames++;
1931 chan->frames_sent++;
1932 sent++;
1933
1934 if (skb_queue_is_last(&chan->tx_q, skb))
1935 chan->tx_send_head = NULL;
1936 else
1937 chan->tx_send_head = skb_queue_next(&chan->tx_q, skb);
1938
1939 l2cap_do_send(chan, tx_skb);
1940 BT_DBG("Sent txseq %u", control->txseq);
1941 }
1942
1943 BT_DBG("Sent %d, %u unacked, %u in ERTM queue", sent,
1944 chan->unacked_frames, skb_queue_len(&chan->tx_q));
1945
1946 return sent;
1947 }
1948
1949 static void l2cap_ertm_resend(struct l2cap_chan *chan)
1950 {
1951 struct l2cap_ctrl control;
1952 struct sk_buff *skb;
1953 struct sk_buff *tx_skb;
1954 u16 seq;
1955
1956 BT_DBG("chan %p", chan);
1957
1958 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
1959 return;
1960
1961 if (__chan_is_moving(chan))
1962 return;
1963
1964 while (chan->retrans_list.head != L2CAP_SEQ_LIST_CLEAR) {
1965 seq = l2cap_seq_list_pop(&chan->retrans_list);
1966
1967 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, seq);
1968 if (!skb) {
1969 BT_DBG("Error: Can't retransmit seq %d, frame missing",
1970 seq);
1971 continue;
1972 }
1973
1974 bt_cb(skb)->l2cap.retries++;
1975 control = bt_cb(skb)->l2cap;
1976
1977 if (chan->max_tx != 0 &&
1978 bt_cb(skb)->l2cap.retries > chan->max_tx) {
1979 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
1980 l2cap_send_disconn_req(chan, ECONNRESET);
1981 l2cap_seq_list_clear(&chan->retrans_list);
1982 break;
1983 }
1984
1985 control.reqseq = chan->buffer_seq;
1986 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
1987 control.final = 1;
1988 else
1989 control.final = 0;
1990
1991 if (skb_cloned(skb)) {
1992 /* Cloned sk_buffs are read-only, so we need a
1993 * writeable copy
1994 */
1995 tx_skb = skb_copy(skb, GFP_KERNEL);
1996 } else {
1997 tx_skb = skb_clone(skb, GFP_KERNEL);
1998 }
1999
2000 if (!tx_skb) {
2001 l2cap_seq_list_clear(&chan->retrans_list);
2002 break;
2003 }
2004
2005 /* Update skb contents */
2006 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
2007 put_unaligned_le32(__pack_extended_control(&control),
2008 tx_skb->data + L2CAP_HDR_SIZE);
2009 } else {
2010 put_unaligned_le16(__pack_enhanced_control(&control),
2011 tx_skb->data + L2CAP_HDR_SIZE);
2012 }
2013
2014 /* Update FCS */
2015 if (chan->fcs == L2CAP_FCS_CRC16) {
2016 u16 fcs = crc16(0, (u8 *) tx_skb->data,
2017 tx_skb->len - L2CAP_FCS_SIZE);
2018 put_unaligned_le16(fcs, skb_tail_pointer(tx_skb) -
2019 L2CAP_FCS_SIZE);
2020 }
2021
2022 l2cap_do_send(chan, tx_skb);
2023
2024 BT_DBG("Resent txseq %d", control.txseq);
2025
2026 chan->last_acked_seq = chan->buffer_seq;
2027 }
2028 }
2029
2030 static void l2cap_retransmit(struct l2cap_chan *chan,
2031 struct l2cap_ctrl *control)
2032 {
2033 BT_DBG("chan %p, control %p", chan, control);
2034
2035 l2cap_seq_list_append(&chan->retrans_list, control->reqseq);
2036 l2cap_ertm_resend(chan);
2037 }
2038
2039 static void l2cap_retransmit_all(struct l2cap_chan *chan,
2040 struct l2cap_ctrl *control)
2041 {
2042 struct sk_buff *skb;
2043
2044 BT_DBG("chan %p, control %p", chan, control);
2045
2046 if (control->poll)
2047 set_bit(CONN_SEND_FBIT, &chan->conn_state);
2048
2049 l2cap_seq_list_clear(&chan->retrans_list);
2050
2051 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
2052 return;
2053
2054 if (chan->unacked_frames) {
2055 skb_queue_walk(&chan->tx_q, skb) {
2056 if (bt_cb(skb)->l2cap.txseq == control->reqseq ||
2057 skb == chan->tx_send_head)
2058 break;
2059 }
2060
2061 skb_queue_walk_from(&chan->tx_q, skb) {
2062 if (skb == chan->tx_send_head)
2063 break;
2064
2065 l2cap_seq_list_append(&chan->retrans_list,
2066 bt_cb(skb)->l2cap.txseq);
2067 }
2068
2069 l2cap_ertm_resend(chan);
2070 }
2071 }
2072
2073 static void l2cap_send_ack(struct l2cap_chan *chan)
2074 {
2075 struct l2cap_ctrl control;
2076 u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
2077 chan->last_acked_seq);
2078 int threshold;
2079
2080 BT_DBG("chan %p last_acked_seq %d buffer_seq %d",
2081 chan, chan->last_acked_seq, chan->buffer_seq);
2082
2083 memset(&control, 0, sizeof(control));
2084 control.sframe = 1;
2085
2086 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
2087 chan->rx_state == L2CAP_RX_STATE_RECV) {
2088 __clear_ack_timer(chan);
2089 control.super = L2CAP_SUPER_RNR;
2090 control.reqseq = chan->buffer_seq;
2091 l2cap_send_sframe(chan, &control);
2092 } else {
2093 if (!test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) {
2094 l2cap_ertm_send(chan);
2095 /* If any i-frames were sent, they included an ack */
2096 if (chan->buffer_seq == chan->last_acked_seq)
2097 frames_to_ack = 0;
2098 }
2099
2100 /* Ack now if the window is 3/4ths full.
2101 * Calculate without mul or div
2102 */
2103 threshold = chan->ack_win;
2104 threshold += threshold << 1;
2105 threshold >>= 2;
2106
2107 BT_DBG("frames_to_ack %u, threshold %d", frames_to_ack,
2108 threshold);
2109
2110 if (frames_to_ack >= threshold) {
2111 __clear_ack_timer(chan);
2112 control.super = L2CAP_SUPER_RR;
2113 control.reqseq = chan->buffer_seq;
2114 l2cap_send_sframe(chan, &control);
2115 frames_to_ack = 0;
2116 }
2117
2118 if (frames_to_ack)
2119 __set_ack_timer(chan);
2120 }
2121 }
2122
2123 static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
2124 struct msghdr *msg, int len,
2125 int count, struct sk_buff *skb)
2126 {
2127 struct l2cap_conn *conn = chan->conn;
2128 struct sk_buff **frag;
2129 int sent = 0;
2130
2131 if (!copy_from_iter_full(skb_put(skb, count), count, &msg->msg_iter))
2132 return -EFAULT;
2133
2134 sent += count;
2135 len -= count;
2136
2137 /* Continuation fragments (no L2CAP header) */
2138 frag = &skb_shinfo(skb)->frag_list;
2139 while (len) {
2140 struct sk_buff *tmp;
2141
2142 count = min_t(unsigned int, conn->mtu, len);
2143
2144 tmp = chan->ops->alloc_skb(chan, 0, count,
2145 msg->msg_flags & MSG_DONTWAIT);
2146 if (IS_ERR(tmp))
2147 return PTR_ERR(tmp);
2148
2149 *frag = tmp;
2150
2151 if (!copy_from_iter_full(skb_put(*frag, count), count,
2152 &msg->msg_iter))
2153 return -EFAULT;
2154
2155 sent += count;
2156 len -= count;
2157
2158 skb->len += (*frag)->len;
2159 skb->data_len += (*frag)->len;
2160
2161 frag = &(*frag)->next;
2162 }
2163
2164 return sent;
2165 }
2166
2167 static struct sk_buff *l2cap_create_connless_pdu(struct l2cap_chan *chan,
2168 struct msghdr *msg, size_t len)
2169 {
2170 struct l2cap_conn *conn = chan->conn;
2171 struct sk_buff *skb;
2172 int err, count, hlen = L2CAP_HDR_SIZE + L2CAP_PSMLEN_SIZE;
2173 struct l2cap_hdr *lh;
2174
2175 BT_DBG("chan %p psm 0x%2.2x len %zu", chan,
2176 __le16_to_cpu(chan->psm), len);
2177
2178 count = min_t(unsigned int, (conn->mtu - hlen), len);
2179
2180 skb = chan->ops->alloc_skb(chan, hlen, count,
2181 msg->msg_flags & MSG_DONTWAIT);
2182 if (IS_ERR(skb))
2183 return skb;
2184
2185 /* Create L2CAP header */
2186 lh = skb_put(skb, L2CAP_HDR_SIZE);
2187 lh->cid = cpu_to_le16(chan->dcid);
2188 lh->len = cpu_to_le16(len + L2CAP_PSMLEN_SIZE);
2189 put_unaligned(chan->psm, (__le16 *) skb_put(skb, L2CAP_PSMLEN_SIZE));
2190
2191 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2192 if (unlikely(err < 0)) {
2193 kfree_skb(skb);
2194 return ERR_PTR(err);
2195 }
2196 return skb;
2197 }
2198
2199 static struct sk_buff *l2cap_create_basic_pdu(struct l2cap_chan *chan,
2200 struct msghdr *msg, size_t len)
2201 {
2202 struct l2cap_conn *conn = chan->conn;
2203 struct sk_buff *skb;
2204 int err, count;
2205 struct l2cap_hdr *lh;
2206
2207 BT_DBG("chan %p len %zu", chan, len);
2208
2209 count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len);
2210
2211 skb = chan->ops->alloc_skb(chan, L2CAP_HDR_SIZE, count,
2212 msg->msg_flags & MSG_DONTWAIT);
2213 if (IS_ERR(skb))
2214 return skb;
2215
2216 /* Create L2CAP header */
2217 lh = skb_put(skb, L2CAP_HDR_SIZE);
2218 lh->cid = cpu_to_le16(chan->dcid);
2219 lh->len = cpu_to_le16(len);
2220
2221 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2222 if (unlikely(err < 0)) {
2223 kfree_skb(skb);
2224 return ERR_PTR(err);
2225 }
2226 return skb;
2227 }
2228
2229 static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan,
2230 struct msghdr *msg, size_t len,
2231 u16 sdulen)
2232 {
2233 struct l2cap_conn *conn = chan->conn;
2234 struct sk_buff *skb;
2235 int err, count, hlen;
2236 struct l2cap_hdr *lh;
2237
2238 BT_DBG("chan %p len %zu", chan, len);
2239
2240 if (!conn)
2241 return ERR_PTR(-ENOTCONN);
2242
2243 hlen = __ertm_hdr_size(chan);
2244
2245 if (sdulen)
2246 hlen += L2CAP_SDULEN_SIZE;
2247
2248 if (chan->fcs == L2CAP_FCS_CRC16)
2249 hlen += L2CAP_FCS_SIZE;
2250
2251 count = min_t(unsigned int, (conn->mtu - hlen), len);
2252
2253 skb = chan->ops->alloc_skb(chan, hlen, count,
2254 msg->msg_flags & MSG_DONTWAIT);
2255 if (IS_ERR(skb))
2256 return skb;
2257
2258 /* Create L2CAP header */
2259 lh = skb_put(skb, L2CAP_HDR_SIZE);
2260 lh->cid = cpu_to_le16(chan->dcid);
2261 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2262
2263 /* Control header is populated later */
2264 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
2265 put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
2266 else
2267 put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
2268
2269 if (sdulen)
2270 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2271
2272 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2273 if (unlikely(err < 0)) {
2274 kfree_skb(skb);
2275 return ERR_PTR(err);
2276 }
2277
2278 bt_cb(skb)->l2cap.fcs = chan->fcs;
2279 bt_cb(skb)->l2cap.retries = 0;
2280 return skb;
2281 }
2282
2283 static int l2cap_segment_sdu(struct l2cap_chan *chan,
2284 struct sk_buff_head *seg_queue,
2285 struct msghdr *msg, size_t len)
2286 {
2287 struct sk_buff *skb;
2288 u16 sdu_len;
2289 size_t pdu_len;
2290 u8 sar;
2291
2292 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2293
2294 /* It is critical that ERTM PDUs fit in a single HCI fragment,
2295 * so fragmented skbs are not used. The HCI layer's handling
2296 * of fragmented skbs is not compatible with ERTM's queueing.
2297 */
2298
2299 /* PDU size is derived from the HCI MTU */
2300 pdu_len = chan->conn->mtu;
2301
2302 /* Constrain PDU size for BR/EDR connections */
2303 if (!chan->hs_hcon)
2304 pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD);
2305
2306 /* Adjust for largest possible L2CAP overhead. */
2307 if (chan->fcs)
2308 pdu_len -= L2CAP_FCS_SIZE;
2309
2310 pdu_len -= __ertm_hdr_size(chan);
2311
2312 /* Remote device may have requested smaller PDUs */
2313 pdu_len = min_t(size_t, pdu_len, chan->remote_mps);
2314
2315 if (len <= pdu_len) {
2316 sar = L2CAP_SAR_UNSEGMENTED;
2317 sdu_len = 0;
2318 pdu_len = len;
2319 } else {
2320 sar = L2CAP_SAR_START;
2321 sdu_len = len;
2322 }
2323
2324 while (len > 0) {
2325 skb = l2cap_create_iframe_pdu(chan, msg, pdu_len, sdu_len);
2326
2327 if (IS_ERR(skb)) {
2328 __skb_queue_purge(seg_queue);
2329 return PTR_ERR(skb);
2330 }
2331
2332 bt_cb(skb)->l2cap.sar = sar;
2333 __skb_queue_tail(seg_queue, skb);
2334
2335 len -= pdu_len;
2336 if (sdu_len)
2337 sdu_len = 0;
2338
2339 if (len <= pdu_len) {
2340 sar = L2CAP_SAR_END;
2341 pdu_len = len;
2342 } else {
2343 sar = L2CAP_SAR_CONTINUE;
2344 }
2345 }
2346
2347 return 0;
2348 }
2349
2350 static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan,
2351 struct msghdr *msg,
2352 size_t len, u16 sdulen)
2353 {
2354 struct l2cap_conn *conn = chan->conn;
2355 struct sk_buff *skb;
2356 int err, count, hlen;
2357 struct l2cap_hdr *lh;
2358
2359 BT_DBG("chan %p len %zu", chan, len);
2360
2361 if (!conn)
2362 return ERR_PTR(-ENOTCONN);
2363
2364 hlen = L2CAP_HDR_SIZE;
2365
2366 if (sdulen)
2367 hlen += L2CAP_SDULEN_SIZE;
2368
2369 count = min_t(unsigned int, (conn->mtu - hlen), len);
2370
2371 skb = chan->ops->alloc_skb(chan, hlen, count,
2372 msg->msg_flags & MSG_DONTWAIT);
2373 if (IS_ERR(skb))
2374 return skb;
2375
2376 /* Create L2CAP header */
2377 lh = skb_put(skb, L2CAP_HDR_SIZE);
2378 lh->cid = cpu_to_le16(chan->dcid);
2379 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2380
2381 if (sdulen)
2382 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2383
2384 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2385 if (unlikely(err < 0)) {
2386 kfree_skb(skb);
2387 return ERR_PTR(err);
2388 }
2389
2390 return skb;
2391 }
2392
2393 static int l2cap_segment_le_sdu(struct l2cap_chan *chan,
2394 struct sk_buff_head *seg_queue,
2395 struct msghdr *msg, size_t len)
2396 {
2397 struct sk_buff *skb;
2398 size_t pdu_len;
2399 u16 sdu_len;
2400
2401 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2402
2403 sdu_len = len;
2404 pdu_len = chan->remote_mps - L2CAP_SDULEN_SIZE;
2405
2406 while (len > 0) {
2407 if (len <= pdu_len)
2408 pdu_len = len;
2409
2410 skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len);
2411 if (IS_ERR(skb)) {
2412 __skb_queue_purge(seg_queue);
2413 return PTR_ERR(skb);
2414 }
2415
2416 __skb_queue_tail(seg_queue, skb);
2417
2418 len -= pdu_len;
2419
2420 if (sdu_len) {
2421 sdu_len = 0;
2422 pdu_len += L2CAP_SDULEN_SIZE;
2423 }
2424 }
2425
2426 return 0;
2427 }
2428
2429 static void l2cap_le_flowctl_send(struct l2cap_chan *chan)
2430 {
2431 int sent = 0;
2432
2433 BT_DBG("chan %p", chan);
2434
2435 while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) {
2436 l2cap_do_send(chan, skb_dequeue(&chan->tx_q));
2437 chan->tx_credits--;
2438 sent++;
2439 }
2440
2441 BT_DBG("Sent %d credits %u queued %u", sent, chan->tx_credits,
2442 skb_queue_len(&chan->tx_q));
2443 }
2444
2445 int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len)
2446 {
2447 struct sk_buff *skb;
2448 int err;
2449 struct sk_buff_head seg_queue;
2450
2451 if (!chan->conn)
2452 return -ENOTCONN;
2453
2454 /* Connectionless channel */
2455 if (chan->chan_type == L2CAP_CHAN_CONN_LESS) {
2456 skb = l2cap_create_connless_pdu(chan, msg, len);
2457 if (IS_ERR(skb))
2458 return PTR_ERR(skb);
2459
2460 /* Channel lock is released before requesting new skb and then
2461 * reacquired thus we need to recheck channel state.
2462 */
2463 if (chan->state != BT_CONNECTED) {
2464 kfree_skb(skb);
2465 return -ENOTCONN;
2466 }
2467
2468 l2cap_do_send(chan, skb);
2469 return len;
2470 }
2471
2472 switch (chan->mode) {
2473 case L2CAP_MODE_LE_FLOWCTL:
2474 /* Check outgoing MTU */
2475 if (len > chan->omtu)
2476 return -EMSGSIZE;
2477
2478 __skb_queue_head_init(&seg_queue);
2479
2480 err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len);
2481
2482 if (chan->state != BT_CONNECTED) {
2483 __skb_queue_purge(&seg_queue);
2484 err = -ENOTCONN;
2485 }
2486
2487 if (err)
2488 return err;
2489
2490 skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
2491
2492 l2cap_le_flowctl_send(chan);
2493
2494 if (!chan->tx_credits)
2495 chan->ops->suspend(chan);
2496
2497 err = len;
2498
2499 break;
2500
2501 case L2CAP_MODE_BASIC:
2502 /* Check outgoing MTU */
2503 if (len > chan->omtu)
2504 return -EMSGSIZE;
2505
2506 /* Create a basic PDU */
2507 skb = l2cap_create_basic_pdu(chan, msg, len);
2508 if (IS_ERR(skb))
2509 return PTR_ERR(skb);
2510
2511 /* Channel lock is released before requesting new skb and then
2512 * reacquired thus we need to recheck channel state.
2513 */
2514 if (chan->state != BT_CONNECTED) {
2515 kfree_skb(skb);
2516 return -ENOTCONN;
2517 }
2518
2519 l2cap_do_send(chan, skb);
2520 err = len;
2521 break;
2522
2523 case L2CAP_MODE_ERTM:
2524 case L2CAP_MODE_STREAMING:
2525 /* Check outgoing MTU */
2526 if (len > chan->omtu) {
2527 err = -EMSGSIZE;
2528 break;
2529 }
2530
2531 __skb_queue_head_init(&seg_queue);
2532
2533 /* Do segmentation before calling in to the state machine,
2534 * since it's possible to block while waiting for memory
2535 * allocation.
2536 */
2537 err = l2cap_segment_sdu(chan, &seg_queue, msg, len);
2538
2539 /* The channel could have been closed while segmenting,
2540 * check that it is still connected.
2541 */
2542 if (chan->state != BT_CONNECTED) {
2543 __skb_queue_purge(&seg_queue);
2544 err = -ENOTCONN;
2545 }
2546
2547 if (err)
2548 break;
2549
2550 if (chan->mode == L2CAP_MODE_ERTM)
2551 l2cap_tx(chan, NULL, &seg_queue, L2CAP_EV_DATA_REQUEST);
2552 else
2553 l2cap_streaming_send(chan, &seg_queue);
2554
2555 err = len;
2556
2557 /* If the skbs were not queued for sending, they'll still be in
2558 * seg_queue and need to be purged.
2559 */
2560 __skb_queue_purge(&seg_queue);
2561 break;
2562
2563 default:
2564 BT_DBG("bad state %1.1x", chan->mode);
2565 err = -EBADFD;
2566 }
2567
2568 return err;
2569 }
2570 EXPORT_SYMBOL_GPL(l2cap_chan_send);
2571
2572 static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq)
2573 {
2574 struct l2cap_ctrl control;
2575 u16 seq;
2576
2577 BT_DBG("chan %p, txseq %u", chan, txseq);
2578
2579 memset(&control, 0, sizeof(control));
2580 control.sframe = 1;
2581 control.super = L2CAP_SUPER_SREJ;
2582
2583 for (seq = chan->expected_tx_seq; seq != txseq;
2584 seq = __next_seq(chan, seq)) {
2585 if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) {
2586 control.reqseq = seq;
2587 l2cap_send_sframe(chan, &control);
2588 l2cap_seq_list_append(&chan->srej_list, seq);
2589 }
2590 }
2591
2592 chan->expected_tx_seq = __next_seq(chan, txseq);
2593 }
2594
2595 static void l2cap_send_srej_tail(struct l2cap_chan *chan)
2596 {
2597 struct l2cap_ctrl control;
2598
2599 BT_DBG("chan %p", chan);
2600
2601 if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR)
2602 return;
2603
2604 memset(&control, 0, sizeof(control));
2605 control.sframe = 1;
2606 control.super = L2CAP_SUPER_SREJ;
2607 control.reqseq = chan->srej_list.tail;
2608 l2cap_send_sframe(chan, &control);
2609 }
2610
2611 static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq)
2612 {
2613 struct l2cap_ctrl control;
2614 u16 initial_head;
2615 u16 seq;
2616
2617 BT_DBG("chan %p, txseq %u", chan, txseq);
2618
2619 memset(&control, 0, sizeof(control));
2620 control.sframe = 1;
2621 control.super = L2CAP_SUPER_SREJ;
2622
2623 /* Capture initial list head to allow only one pass through the list. */
2624 initial_head = chan->srej_list.head;
2625
2626 do {
2627 seq = l2cap_seq_list_pop(&chan->srej_list);
2628 if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR)
2629 break;
2630
2631 control.reqseq = seq;
2632 l2cap_send_sframe(chan, &control);
2633 l2cap_seq_list_append(&chan->srej_list, seq);
2634 } while (chan->srej_list.head != initial_head);
2635 }
2636
2637 static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq)
2638 {
2639 struct sk_buff *acked_skb;
2640 u16 ackseq;
2641
2642 BT_DBG("chan %p, reqseq %u", chan, reqseq);
2643
2644 if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq)
2645 return;
2646
2647 BT_DBG("expected_ack_seq %u, unacked_frames %u",
2648 chan->expected_ack_seq, chan->unacked_frames);
2649
2650 for (ackseq = chan->expected_ack_seq; ackseq != reqseq;
2651 ackseq = __next_seq(chan, ackseq)) {
2652
2653 acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq);
2654 if (acked_skb) {
2655 skb_unlink(acked_skb, &chan->tx_q);
2656 kfree_skb(acked_skb);
2657 chan->unacked_frames--;
2658 }
2659 }
2660
2661 chan->expected_ack_seq = reqseq;
2662
2663 if (chan->unacked_frames == 0)
2664 __clear_retrans_timer(chan);
2665
2666 BT_DBG("unacked_frames %u", chan->unacked_frames);
2667 }
2668
2669 static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan)
2670 {
2671 BT_DBG("chan %p", chan);
2672
2673 chan->expected_tx_seq = chan->buffer_seq;
2674 l2cap_seq_list_clear(&chan->srej_list);
2675 skb_queue_purge(&chan->srej_q);
2676 chan->rx_state = L2CAP_RX_STATE_RECV;
2677 }
2678
2679 static void l2cap_tx_state_xmit(struct l2cap_chan *chan,
2680 struct l2cap_ctrl *control,
2681 struct sk_buff_head *skbs, u8 event)
2682 {
2683 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2684 event);
2685
2686 switch (event) {
2687 case L2CAP_EV_DATA_REQUEST:
2688 if (chan->tx_send_head == NULL)
2689 chan->tx_send_head = skb_peek(skbs);
2690
2691 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2692 l2cap_ertm_send(chan);
2693 break;
2694 case L2CAP_EV_LOCAL_BUSY_DETECTED:
2695 BT_DBG("Enter LOCAL_BUSY");
2696 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2697
2698 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2699 /* The SREJ_SENT state must be aborted if we are to
2700 * enter the LOCAL_BUSY state.
2701 */
2702 l2cap_abort_rx_srej_sent(chan);
2703 }
2704
2705 l2cap_send_ack(chan);
2706
2707 break;
2708 case L2CAP_EV_LOCAL_BUSY_CLEAR:
2709 BT_DBG("Exit LOCAL_BUSY");
2710 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2711
2712 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2713 struct l2cap_ctrl local_control;
2714
2715 memset(&local_control, 0, sizeof(local_control));
2716 local_control.sframe = 1;
2717 local_control.super = L2CAP_SUPER_RR;
2718 local_control.poll = 1;
2719 local_control.reqseq = chan->buffer_seq;
2720 l2cap_send_sframe(chan, &local_control);
2721
2722 chan->retry_count = 1;
2723 __set_monitor_timer(chan);
2724 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2725 }
2726 break;
2727 case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2728 l2cap_process_reqseq(chan, control->reqseq);
2729 break;
2730 case L2CAP_EV_EXPLICIT_POLL:
2731 l2cap_send_rr_or_rnr(chan, 1);
2732 chan->retry_count = 1;
2733 __set_monitor_timer(chan);
2734 __clear_ack_timer(chan);
2735 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2736 break;
2737 case L2CAP_EV_RETRANS_TO:
2738 l2cap_send_rr_or_rnr(chan, 1);
2739 chan->retry_count = 1;
2740 __set_monitor_timer(chan);
2741 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2742 break;
2743 case L2CAP_EV_RECV_FBIT:
2744 /* Nothing to process */
2745 break;
2746 default:
2747 break;
2748 }
2749 }
2750
2751 static void l2cap_tx_state_wait_f(struct l2cap_chan *chan,
2752 struct l2cap_ctrl *control,
2753 struct sk_buff_head *skbs, u8 event)
2754 {
2755 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2756 event);
2757
2758 switch (event) {
2759 case L2CAP_EV_DATA_REQUEST:
2760 if (chan->tx_send_head == NULL)
2761 chan->tx_send_head = skb_peek(skbs);
2762 /* Queue data, but don't send. */
2763 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2764 break;
2765 case L2CAP_EV_LOCAL_BUSY_DETECTED:
2766 BT_DBG("Enter LOCAL_BUSY");
2767 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2768
2769 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2770 /* The SREJ_SENT state must be aborted if we are to
2771 * enter the LOCAL_BUSY state.
2772 */
2773 l2cap_abort_rx_srej_sent(chan);
2774 }
2775
2776 l2cap_send_ack(chan);
2777
2778 break;
2779 case L2CAP_EV_LOCAL_BUSY_CLEAR:
2780 BT_DBG("Exit LOCAL_BUSY");
2781 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2782
2783 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2784 struct l2cap_ctrl local_control;
2785 memset(&local_control, 0, sizeof(local_control));
2786 local_control.sframe = 1;
2787 local_control.super = L2CAP_SUPER_RR;
2788 local_control.poll = 1;
2789 local_control.reqseq = chan->buffer_seq;
2790 l2cap_send_sframe(chan, &local_control);
2791
2792 chan->retry_count = 1;
2793 __set_monitor_timer(chan);
2794 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2795 }
2796 break;
2797 case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2798 l2cap_process_reqseq(chan, control->reqseq);
2799
2800 /* Fall through */
2801
2802 case L2CAP_EV_RECV_FBIT:
2803 if (control && control->final) {
2804 __clear_monitor_timer(chan);
2805 if (chan->unacked_frames > 0)
2806 __set_retrans_timer(chan);
2807 chan->retry_count = 0;
2808 chan->tx_state = L2CAP_TX_STATE_XMIT;
2809 BT_DBG("recv fbit tx_state 0x2.2%x", chan->tx_state);
2810 }
2811 break;
2812 case L2CAP_EV_EXPLICIT_POLL:
2813 /* Ignore */
2814 break;
2815 case L2CAP_EV_MONITOR_TO:
2816 if (chan->max_tx == 0 || chan->retry_count < chan->max_tx) {
2817 l2cap_send_rr_or_rnr(chan, 1);
2818 __set_monitor_timer(chan);
2819 chan->retry_count++;
2820 } else {
2821 l2cap_send_disconn_req(chan, ECONNABORTED);
2822 }
2823 break;
2824 default:
2825 break;
2826 }
2827 }
2828
2829 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
2830 struct sk_buff_head *skbs, u8 event)
2831 {
2832 BT_DBG("chan %p, control %p, skbs %p, event %d, state %d",
2833 chan, control, skbs, event, chan->tx_state);
2834
2835 switch (chan->tx_state) {
2836 case L2CAP_TX_STATE_XMIT:
2837 l2cap_tx_state_xmit(chan, control, skbs, event);
2838 break;
2839 case L2CAP_TX_STATE_WAIT_F:
2840 l2cap_tx_state_wait_f(chan, control, skbs, event);
2841 break;
2842 default:
2843 /* Ignore event */
2844 break;
2845 }
2846 }
2847
2848 static void l2cap_pass_to_tx(struct l2cap_chan *chan,
2849 struct l2cap_ctrl *control)
2850 {
2851 BT_DBG("chan %p, control %p", chan, control);
2852 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_REQSEQ_AND_FBIT);
2853 }
2854
2855 static void l2cap_pass_to_tx_fbit(struct l2cap_chan *chan,
2856 struct l2cap_ctrl *control)
2857 {
2858 BT_DBG("chan %p, control %p", chan, control);
2859 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_FBIT);
2860 }
2861
2862 /* Copy frame to all raw sockets on that connection */
2863 static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
2864 {
2865 struct sk_buff *nskb;
2866 struct l2cap_chan *chan;
2867
2868 BT_DBG("conn %p", conn);
2869
2870 mutex_lock(&conn->chan_lock);
2871
2872 list_for_each_entry(chan, &conn->chan_l, list) {
2873 if (chan->chan_type != L2CAP_CHAN_RAW)
2874 continue;
2875
2876 /* Don't send frame to the channel it came from */
2877 if (bt_cb(skb)->l2cap.chan == chan)
2878 continue;
2879
2880 nskb = skb_clone(skb, GFP_KERNEL);
2881 if (!nskb)
2882 continue;
2883 if (chan->ops->recv(chan, nskb))
2884 kfree_skb(nskb);
2885 }
2886
2887 mutex_unlock(&conn->chan_lock);
2888 }
2889
2890 /* ---- L2CAP signalling commands ---- */
2891 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code,
2892 u8 ident, u16 dlen, void *data)
2893 {
2894 struct sk_buff *skb, **frag;
2895 struct l2cap_cmd_hdr *cmd;
2896 struct l2cap_hdr *lh;
2897 int len, count;
2898
2899 BT_DBG("conn %p, code 0x%2.2x, ident 0x%2.2x, len %u",
2900 conn, code, ident, dlen);
2901
2902 if (conn->mtu < L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE)
2903 return NULL;
2904
2905 len = L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE + dlen;
2906 count = min_t(unsigned int, conn->mtu, len);
2907
2908 skb = bt_skb_alloc(count, GFP_KERNEL);
2909 if (!skb)
2910 return NULL;
2911
2912 lh = skb_put(skb, L2CAP_HDR_SIZE);
2913 lh->len = cpu_to_le16(L2CAP_CMD_HDR_SIZE + dlen);
2914
2915 if (conn->hcon->type == LE_LINK)
2916 lh->cid = cpu_to_le16(L2CAP_CID_LE_SIGNALING);
2917 else
2918 lh->cid = cpu_to_le16(L2CAP_CID_SIGNALING);
2919
2920 cmd = skb_put(skb, L2CAP_CMD_HDR_SIZE);
2921 cmd->code = code;
2922 cmd->ident = ident;
2923 cmd->len = cpu_to_le16(dlen);
2924
2925 if (dlen) {
2926 count -= L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE;
2927 skb_put_data(skb, data, count);
2928 data += count;
2929 }
2930
2931 len -= skb->len;
2932
2933 /* Continuation fragments (no L2CAP header) */
2934 frag = &skb_shinfo(skb)->frag_list;
2935 while (len) {
2936 count = min_t(unsigned int, conn->mtu, len);
2937
2938 *frag = bt_skb_alloc(count, GFP_KERNEL);
2939 if (!*frag)
2940 goto fail;
2941
2942 skb_put_data(*frag, data, count);
2943
2944 len -= count;
2945 data += count;
2946
2947 frag = &(*frag)->next;
2948 }
2949
2950 return skb;
2951
2952 fail:
2953 kfree_skb(skb);
2954 return NULL;
2955 }
2956
2957 static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen,
2958 unsigned long *val)
2959 {
2960 struct l2cap_conf_opt *opt = *ptr;
2961 int len;
2962
2963 len = L2CAP_CONF_OPT_SIZE + opt->len;
2964 *ptr += len;
2965
2966 *type = opt->type;
2967 *olen = opt->len;
2968
2969 switch (opt->len) {
2970 case 1:
2971 *val = *((u8 *) opt->val);
2972 break;
2973
2974 case 2:
2975 *val = get_unaligned_le16(opt->val);
2976 break;
2977
2978 case 4:
2979 *val = get_unaligned_le32(opt->val);
2980 break;
2981
2982 default:
2983 *val = (unsigned long) opt->val;
2984 break;
2985 }
2986
2987 BT_DBG("type 0x%2.2x len %u val 0x%lx", *type, opt->len, *val);
2988 return len;
2989 }
2990
2991 static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val, size_t size)
2992 {
2993 struct l2cap_conf_opt *opt = *ptr;
2994
2995 BT_DBG("type 0x%2.2x len %u val 0x%lx", type, len, val);
2996
2997 if (size < L2CAP_CONF_OPT_SIZE + len)
2998 return;
2999
3000 opt->type = type;
3001 opt->len = len;
3002
3003 switch (len) {
3004 case 1:
3005 *((u8 *) opt->val) = val;
3006 break;
3007
3008 case 2:
3009 put_unaligned_le16(val, opt->val);
3010 break;
3011
3012 case 4:
3013 put_unaligned_le32(val, opt->val);
3014 break;
3015
3016 default:
3017 memcpy(opt->val, (void *) val, len);
3018 break;
3019 }
3020
3021 *ptr += L2CAP_CONF_OPT_SIZE + len;
3022 }
3023
3024 static void l2cap_add_opt_efs(void **ptr, struct l2cap_chan *chan, size_t size)
3025 {
3026 struct l2cap_conf_efs efs;
3027
3028 switch (chan->mode) {
3029 case L2CAP_MODE_ERTM:
3030 efs.id = chan->local_id;
3031 efs.stype = chan->local_stype;
3032 efs.msdu = cpu_to_le16(chan->local_msdu);
3033 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
3034 efs.acc_lat = cpu_to_le32(L2CAP_DEFAULT_ACC_LAT);
3035 efs.flush_to = cpu_to_le32(L2CAP_EFS_DEFAULT_FLUSH_TO);
3036 break;
3037
3038 case L2CAP_MODE_STREAMING:
3039 efs.id = 1;
3040 efs.stype = L2CAP_SERV_BESTEFFORT;
3041 efs.msdu = cpu_to_le16(chan->local_msdu);
3042 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
3043 efs.acc_lat = 0;
3044 efs.flush_to = 0;
3045 break;
3046
3047 default:
3048 return;
3049 }
3050
3051 l2cap_add_conf_opt(ptr, L2CAP_CONF_EFS, sizeof(efs),
3052 (unsigned long) &efs, size);
3053 }
3054
3055 static void l2cap_ack_timeout(struct work_struct *work)
3056 {
3057 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
3058 ack_timer.work);
3059 u16 frames_to_ack;
3060
3061 BT_DBG("chan %p", chan);
3062
3063 l2cap_chan_lock(chan);
3064
3065 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
3066 chan->last_acked_seq);
3067
3068 if (frames_to_ack)
3069 l2cap_send_rr_or_rnr(chan, 0);
3070
3071 l2cap_chan_unlock(chan);
3072 l2cap_chan_put(chan);
3073 }
3074
3075 int l2cap_ertm_init(struct l2cap_chan *chan)
3076 {
3077 int err;
3078
3079 chan->next_tx_seq = 0;
3080 chan->expected_tx_seq = 0;
3081 chan->expected_ack_seq = 0;
3082 chan->unacked_frames = 0;
3083 chan->buffer_seq = 0;
3084 chan->frames_sent = 0;
3085 chan->last_acked_seq = 0;
3086 chan->sdu = NULL;
3087 chan->sdu_last_frag = NULL;
3088 chan->sdu_len = 0;
3089
3090 skb_queue_head_init(&chan->tx_q);
3091
3092 chan->local_amp_id = AMP_ID_BREDR;
3093 chan->move_id = AMP_ID_BREDR;
3094 chan->move_state = L2CAP_MOVE_STABLE;
3095 chan->move_role = L2CAP_MOVE_ROLE_NONE;
3096
3097 if (chan->mode != L2CAP_MODE_ERTM)
3098 return 0;
3099
3100 chan->rx_state = L2CAP_RX_STATE_RECV;
3101 chan->tx_state = L2CAP_TX_STATE_XMIT;
3102
3103 INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout);
3104 INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout);
3105 INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout);
3106
3107 skb_queue_head_init(&chan->srej_q);
3108
3109 err = l2cap_seq_list_init(&chan->srej_list, chan->tx_win);
3110 if (err < 0)
3111 return err;
3112
3113 err = l2cap_seq_list_init(&chan->retrans_list, chan->remote_tx_win);
3114 if (err < 0)
3115 l2cap_seq_list_free(&chan->srej_list);
3116
3117 return err;
3118 }
3119
3120 static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
3121 {
3122 switch (mode) {
3123 case L2CAP_MODE_STREAMING:
3124 case L2CAP_MODE_ERTM:
3125 if (l2cap_mode_supported(mode, remote_feat_mask))
3126 return mode;
3127 /* fall through */
3128 default:
3129 return L2CAP_MODE_BASIC;
3130 }
3131 }
3132
3133 static inline bool __l2cap_ews_supported(struct l2cap_conn *conn)
3134 {
3135 return ((conn->local_fixed_chan & L2CAP_FC_A2MP) &&
3136 (conn->feat_mask & L2CAP_FEAT_EXT_WINDOW));
3137 }
3138
3139 static inline bool __l2cap_efs_supported(struct l2cap_conn *conn)
3140 {
3141 return ((conn->local_fixed_chan & L2CAP_FC_A2MP) &&
3142 (conn->feat_mask & L2CAP_FEAT_EXT_FLOW));
3143 }
3144
3145 static void __l2cap_set_ertm_timeouts(struct l2cap_chan *chan,
3146 struct l2cap_conf_rfc *rfc)
3147 {
3148 if (chan->local_amp_id != AMP_ID_BREDR && chan->hs_hcon) {
3149 u64 ertm_to = chan->hs_hcon->hdev->amp_be_flush_to;
3150
3151 /* Class 1 devices have must have ERTM timeouts
3152 * exceeding the Link Supervision Timeout. The
3153 * default Link Supervision Timeout for AMP
3154 * controllers is 10 seconds.
3155 *
3156 * Class 1 devices use 0xffffffff for their
3157 * best-effort flush timeout, so the clamping logic
3158 * will result in a timeout that meets the above
3159 * requirement. ERTM timeouts are 16-bit values, so
3160 * the maximum timeout is 65.535 seconds.
3161 */
3162
3163 /* Convert timeout to milliseconds and round */
3164 ertm_to = DIV_ROUND_UP_ULL(ertm_to, 1000);
3165
3166 /* This is the recommended formula for class 2 devices
3167 * that start ERTM timers when packets are sent to the
3168 * controller.
3169 */
3170 ertm_to = 3 * ertm_to + 500;
3171
3172 if (ertm_to > 0xffff)
3173 ertm_to = 0xffff;
3174
3175 rfc->retrans_timeout = cpu_to_le16((u16) ertm_to);
3176 rfc->monitor_timeout = rfc->retrans_timeout;
3177 } else {
3178 rfc->retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO);
3179 rfc->monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO);
3180 }
3181 }
3182
3183 static inline void l2cap_txwin_setup(struct l2cap_chan *chan)
3184 {
3185 if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW &&
3186 __l2cap_ews_supported(chan->conn)) {
3187 /* use extended control field */
3188 set_bit(FLAG_EXT_CTRL, &chan->flags);
3189 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
3190 } else {
3191 chan->tx_win = min_t(u16, chan->tx_win,
3192 L2CAP_DEFAULT_TX_WINDOW);
3193 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
3194 }
3195 chan->ack_win = chan->tx_win;
3196 }
3197
3198 static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
3199 {
3200 struct l2cap_conf_req *req = data;
3201 struct l2cap_conf_rfc rfc = { .mode = chan->mode };
3202 void *ptr = req->data;
3203 void *endptr = data + data_size;
3204 u16 size;
3205
3206 BT_DBG("chan %p", chan);
3207
3208 if (chan->num_conf_req || chan->num_conf_rsp)
3209 goto done;
3210
3211 switch (chan->mode) {
3212 case L2CAP_MODE_STREAMING:
3213 case L2CAP_MODE_ERTM:
3214 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state))
3215 break;
3216
3217 if (__l2cap_efs_supported(chan->conn))
3218 set_bit(FLAG_EFS_ENABLE, &chan->flags);
3219
3220 /* fall through */
3221 default:
3222 chan->mode = l2cap_select_mode(rfc.mode, chan->conn->feat_mask);
3223 break;
3224 }
3225
3226 done:
3227 if (chan->imtu != L2CAP_DEFAULT_MTU)
3228 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu, endptr - ptr);
3229
3230 switch (chan->mode) {
3231 case L2CAP_MODE_BASIC:
3232 if (disable_ertm)
3233 break;
3234
3235 if (!(chan->conn->feat_mask & L2CAP_FEAT_ERTM) &&
3236 !(chan->conn->feat_mask & L2CAP_FEAT_STREAMING))
3237 break;
3238
3239 rfc.mode = L2CAP_MODE_BASIC;
3240 rfc.txwin_size = 0;
3241 rfc.max_transmit = 0;
3242 rfc.retrans_timeout = 0;
3243 rfc.monitor_timeout = 0;
3244 rfc.max_pdu_size = 0;
3245
3246 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3247 (unsigned long) &rfc, endptr - ptr);
3248 break;
3249
3250 case L2CAP_MODE_ERTM:
3251 rfc.mode = L2CAP_MODE_ERTM;
3252 rfc.max_transmit = chan->max_tx;
3253
3254 __l2cap_set_ertm_timeouts(chan, &rfc);
3255
3256 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3257 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3258 L2CAP_FCS_SIZE);
3259 rfc.max_pdu_size = cpu_to_le16(size);
3260
3261 l2cap_txwin_setup(chan);
3262
3263 rfc.txwin_size = min_t(u16, chan->tx_win,
3264 L2CAP_DEFAULT_TX_WINDOW);
3265
3266 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3267 (unsigned long) &rfc, endptr - ptr);
3268
3269 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3270 l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
3271
3272 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
3273 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3274 chan->tx_win, endptr - ptr);
3275
3276 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3277 if (chan->fcs == L2CAP_FCS_NONE ||
3278 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3279 chan->fcs = L2CAP_FCS_NONE;
3280 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3281 chan->fcs, endptr - ptr);
3282 }
3283 break;
3284
3285 case L2CAP_MODE_STREAMING:
3286 l2cap_txwin_setup(chan);
3287 rfc.mode = L2CAP_MODE_STREAMING;
3288 rfc.txwin_size = 0;
3289 rfc.max_transmit = 0;
3290 rfc.retrans_timeout = 0;
3291 rfc.monitor_timeout = 0;
3292
3293 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3294 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3295 L2CAP_FCS_SIZE);
3296 rfc.max_pdu_size = cpu_to_le16(size);
3297
3298 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3299 (unsigned long) &rfc, endptr - ptr);
3300
3301 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3302 l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
3303
3304 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3305 if (chan->fcs == L2CAP_FCS_NONE ||
3306 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3307 chan->fcs = L2CAP_FCS_NONE;
3308 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3309 chan->fcs, endptr - ptr);
3310 }
3311 break;
3312 }
3313
3314 req->dcid = cpu_to_le16(chan->dcid);
3315 req->flags = cpu_to_le16(0);
3316
3317 return ptr - data;
3318 }
3319
3320 static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
3321 {
3322 struct l2cap_conf_rsp *rsp = data;
3323 void *ptr = rsp->data;
3324 void *endptr = data + data_size;
3325 void *req = chan->conf_req;
3326 int len = chan->conf_len;
3327 int type, hint, olen;
3328 unsigned long val;
3329 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
3330 struct l2cap_conf_efs efs;
3331 u8 remote_efs = 0;
3332 u16 mtu = L2CAP_DEFAULT_MTU;
3333 u16 result = L2CAP_CONF_SUCCESS;
3334 u16 size;
3335
3336 BT_DBG("chan %p", chan);
3337
3338 while (len >= L2CAP_CONF_OPT_SIZE) {
3339 len -= l2cap_get_conf_opt(&req, &type, &olen, &val);
3340 if (len < 0)
3341 break;
3342
3343 hint = type & L2CAP_CONF_HINT;
3344 type &= L2CAP_CONF_MASK;
3345
3346 switch (type) {
3347 case L2CAP_CONF_MTU:
3348 if (olen != 2)
3349 break;
3350 mtu = val;
3351 break;
3352
3353 case L2CAP_CONF_FLUSH_TO:
3354 if (olen != 2)
3355 break;
3356 chan->flush_to = val;
3357 break;
3358
3359 case L2CAP_CONF_QOS:
3360 break;
3361
3362 case L2CAP_CONF_RFC:
3363 if (olen != sizeof(rfc))
3364 break;
3365 memcpy(&rfc, (void *) val, olen);
3366 break;
3367
3368 case L2CAP_CONF_FCS:
3369 if (olen != 1)
3370 break;
3371 if (val == L2CAP_FCS_NONE)
3372 set_bit(CONF_RECV_NO_FCS, &chan->conf_state);
3373 break;
3374
3375 case L2CAP_CONF_EFS:
3376 if (olen != sizeof(efs))
3377 break;
3378 remote_efs = 1;
3379 memcpy(&efs, (void *) val, olen);
3380 break;
3381
3382 case L2CAP_CONF_EWS:
3383 if (olen != 2)
3384 break;
3385 if (!(chan->conn->local_fixed_chan & L2CAP_FC_A2MP))
3386 return -ECONNREFUSED;
3387 set_bit(FLAG_EXT_CTRL, &chan->flags);
3388 set_bit(CONF_EWS_RECV, &chan->conf_state);
3389 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
3390 chan->remote_tx_win = val;
3391 break;
3392
3393 default:
3394 if (hint)
3395 break;
3396 result = L2CAP_CONF_UNKNOWN;
3397 *((u8 *) ptr++) = type;
3398 break;
3399 }
3400 }
3401
3402 if (chan->num_conf_rsp || chan->num_conf_req > 1)
3403 goto done;
3404
3405 switch (chan->mode) {
3406 case L2CAP_MODE_STREAMING:
3407 case L2CAP_MODE_ERTM:
3408 if (!test_bit(CONF_STATE2_DEVICE, &chan->conf_state)) {
3409 chan->mode = l2cap_select_mode(rfc.mode,
3410 chan->conn->feat_mask);
3411 break;
3412 }
3413
3414 if (remote_efs) {
3415 if (__l2cap_efs_supported(chan->conn))
3416 set_bit(FLAG_EFS_ENABLE, &chan->flags);
3417 else
3418 return -ECONNREFUSED;
3419 }
3420
3421 if (chan->mode != rfc.mode)
3422 return -ECONNREFUSED;
3423
3424 break;
3425 }
3426
3427 done:
3428 if (chan->mode != rfc.mode) {
3429 result = L2CAP_CONF_UNACCEPT;
3430 rfc.mode = chan->mode;
3431
3432 if (chan->num_conf_rsp == 1)
3433 return -ECONNREFUSED;
3434
3435 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3436 (unsigned long) &rfc, endptr - ptr);
3437 }
3438
3439 if (result == L2CAP_CONF_SUCCESS) {
3440 /* Configure output options and let the other side know
3441 * which ones we don't like. */
3442
3443 if (mtu < L2CAP_DEFAULT_MIN_MTU)
3444 result = L2CAP_CONF_UNACCEPT;
3445 else {
3446 chan->omtu = mtu;
3447 set_bit(CONF_MTU_DONE, &chan->conf_state);
3448 }
3449 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->omtu, endptr - ptr);
3450
3451 if (remote_efs) {
3452 if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
3453 efs.stype != L2CAP_SERV_NOTRAFIC &&
3454 efs.stype != chan->local_stype) {
3455
3456 result = L2CAP_CONF_UNACCEPT;
3457
3458 if (chan->num_conf_req >= 1)
3459 return -ECONNREFUSED;
3460
3461 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
3462 sizeof(efs),
3463 (unsigned long) &efs, endptr - ptr);
3464 } else {
3465 /* Send PENDING Conf Rsp */
3466 result = L2CAP_CONF_PENDING;
3467 set_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
3468 }
3469 }
3470
3471 switch (rfc.mode) {
3472 case L2CAP_MODE_BASIC:
3473 chan->fcs = L2CAP_FCS_NONE;
3474 set_bit(CONF_MODE_DONE, &chan->conf_state);
3475 break;
3476
3477 case L2CAP_MODE_ERTM:
3478 if (!test_bit(CONF_EWS_RECV, &chan->conf_state))
3479 chan->remote_tx_win = rfc.txwin_size;
3480 else
3481 rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW;
3482
3483 chan->remote_max_tx = rfc.max_transmit;
3484
3485 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
3486 chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
3487 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
3488 rfc.max_pdu_size = cpu_to_le16(size);
3489 chan->remote_mps = size;
3490
3491 __l2cap_set_ertm_timeouts(chan, &rfc);
3492
3493 set_bit(CONF_MODE_DONE, &chan->conf_state);
3494
3495 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
3496 sizeof(rfc), (unsigned long) &rfc, endptr - ptr);
3497
3498 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
3499 chan->remote_id = efs.id;
3500 chan->remote_stype = efs.stype;
3501 chan->remote_msdu = le16_to_cpu(efs.msdu);
3502 chan->remote_flush_to =
3503 le32_to_cpu(efs.flush_to);
3504 chan->remote_acc_lat =
3505 le32_to_cpu(efs.acc_lat);
3506 chan->remote_sdu_itime =
3507 le32_to_cpu(efs.sdu_itime);
3508 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
3509 sizeof(efs),
3510 (unsigned long) &efs, endptr - ptr);
3511 }
3512 break;
3513
3514 case L2CAP_MODE_STREAMING:
3515 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
3516 chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
3517 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
3518 rfc.max_pdu_size = cpu_to_le16(size);
3519 chan->remote_mps = size;
3520
3521 set_bit(CONF_MODE_DONE, &chan->conf_state);
3522
3523 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3524 (unsigned long) &rfc, endptr - ptr);
3525
3526 break;
3527
3528 default:
3529 result = L2CAP_CONF_UNACCEPT;
3530
3531 memset(&rfc, 0, sizeof(rfc));
3532 rfc.mode = chan->mode;
3533 }
3534
3535 if (result == L2CAP_CONF_SUCCESS)
3536 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
3537 }
3538 rsp->scid = cpu_to_le16(chan->dcid);
3539 rsp->result = cpu_to_le16(result);
3540 rsp->flags = cpu_to_le16(0);
3541
3542 return ptr - data;
3543 }
3544
3545 static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len,
3546 void *data, size_t size, u16 *result)
3547 {
3548 struct l2cap_conf_req *req = data;
3549 void *ptr = req->data;
3550 void *endptr = data + size;
3551 int type, olen;
3552 unsigned long val;
3553 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
3554 struct l2cap_conf_efs efs;
3555
3556 BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data);
3557
3558 while (len >= L2CAP_CONF_OPT_SIZE) {
3559 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
3560 if (len < 0)
3561 break;
3562
3563 switch (type) {
3564 case L2CAP_CONF_MTU:
3565 if (olen != 2)
3566 break;
3567 if (val < L2CAP_DEFAULT_MIN_MTU) {
3568 *result = L2CAP_CONF_UNACCEPT;
3569 chan->imtu = L2CAP_DEFAULT_MIN_MTU;
3570 } else
3571 chan->imtu = val;
3572 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu,
3573 endptr - ptr);
3574 break;
3575
3576 case L2CAP_CONF_FLUSH_TO:
3577 if (olen != 2)
3578 break;
3579 chan->flush_to = val;
3580 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, 2,
3581 chan->flush_to, endptr - ptr);
3582 break;
3583
3584 case L2CAP_CONF_RFC:
3585 if (olen != sizeof(rfc))
3586 break;
3587 memcpy(&rfc, (void *)val, olen);
3588 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state) &&
3589 rfc.mode != chan->mode)
3590 return -ECONNREFUSED;
3591 chan->fcs = 0;
3592 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3593 (unsigned long) &rfc, endptr - ptr);
3594 break;
3595
3596 case L2CAP_CONF_EWS:
3597 if (olen != 2)
3598 break;
3599 chan->ack_win = min_t(u16, val, chan->ack_win);
3600 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3601 chan->tx_win, endptr - ptr);
3602 break;
3603
3604 case L2CAP_CONF_EFS:
3605 if (olen != sizeof(efs))
3606 break;
3607 memcpy(&efs, (void *)val, olen);
3608 if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
3609 efs.stype != L2CAP_SERV_NOTRAFIC &&
3610 efs.stype != chan->local_stype)
3611 return -ECONNREFUSED;
3612 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs),
3613 (unsigned long) &efs, endptr - ptr);
3614 break;
3615
3616 case L2CAP_CONF_FCS:
3617 if (olen != 1)
3618 break;
3619 if (*result == L2CAP_CONF_PENDING)
3620 if (val == L2CAP_FCS_NONE)
3621 set_bit(CONF_RECV_NO_FCS,
3622 &chan->conf_state);
3623 break;
3624 }
3625 }
3626
3627 if (chan->mode == L2CAP_MODE_BASIC && chan->mode != rfc.mode)
3628 return -ECONNREFUSED;
3629
3630 chan->mode = rfc.mode;
3631
3632 if (*result == L2CAP_CONF_SUCCESS || *result == L2CAP_CONF_PENDING) {
3633 switch (rfc.mode) {
3634 case L2CAP_MODE_ERTM:
3635 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
3636 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
3637 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3638 if (!test_bit(FLAG_EXT_CTRL, &chan->flags))
3639 chan->ack_win = min_t(u16, chan->ack_win,
3640 rfc.txwin_size);
3641
3642 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
3643 chan->local_msdu = le16_to_cpu(efs.msdu);
3644 chan->local_sdu_itime =
3645 le32_to_cpu(efs.sdu_itime);
3646 chan->local_acc_lat = le32_to_cpu(efs.acc_lat);
3647 chan->local_flush_to =
3648 le32_to_cpu(efs.flush_to);
3649 }
3650 break;
3651
3652 case L2CAP_MODE_STREAMING:
3653 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3654 }
3655 }
3656
3657 req->dcid = cpu_to_le16(chan->dcid);
3658 req->flags = cpu_to_le16(0);
3659
3660 return ptr - data;
3661 }
3662
3663 static int l2cap_build_conf_rsp(struct l2cap_chan *chan, void *data,
3664 u16 result, u16 flags)
3665 {
3666 struct l2cap_conf_rsp *rsp = data;
3667 void *ptr = rsp->data;
3668
3669 BT_DBG("chan %p", chan);
3670
3671 rsp->scid = cpu_to_le16(chan->dcid);
3672 rsp->result = cpu_to_le16(result);
3673 rsp->flags = cpu_to_le16(flags);
3674
3675 return ptr - data;
3676 }
3677
3678 void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan)
3679 {
3680 struct l2cap_le_conn_rsp rsp;
3681 struct l2cap_conn *conn = chan->conn;
3682
3683 BT_DBG("chan %p", chan);
3684
3685 rsp.dcid = cpu_to_le16(chan->scid);
3686 rsp.mtu = cpu_to_le16(chan->imtu);
3687 rsp.mps = cpu_to_le16(chan->mps);
3688 rsp.credits = cpu_to_le16(chan->rx_credits);
3689 rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS);
3690
3691 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
3692 &rsp);
3693 }
3694
3695 void __l2cap_connect_rsp_defer(struct l2cap_chan *chan)
3696 {
3697 struct l2cap_conn_rsp rsp;
3698 struct l2cap_conn *conn = chan->conn;
3699 u8 buf[128];
3700 u8 rsp_code;
3701
3702 rsp.scid = cpu_to_le16(chan->dcid);
3703 rsp.dcid = cpu_to_le16(chan->scid);
3704 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
3705 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
3706
3707 if (chan->hs_hcon)
3708 rsp_code = L2CAP_CREATE_CHAN_RSP;
3709 else
3710 rsp_code = L2CAP_CONN_RSP;
3711
3712 BT_DBG("chan %p rsp_code %u", chan, rsp_code);
3713
3714 l2cap_send_cmd(conn, chan->ident, rsp_code, sizeof(rsp), &rsp);
3715
3716 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
3717 return;
3718
3719 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
3720 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
3721 chan->num_conf_req++;
3722 }
3723
3724 static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len)
3725 {
3726 int type, olen;
3727 unsigned long val;
3728 /* Use sane default values in case a misbehaving remote device
3729 * did not send an RFC or extended window size option.
3730 */
3731 u16 txwin_ext = chan->ack_win;
3732 struct l2cap_conf_rfc rfc = {
3733 .mode = chan->mode,
3734 .retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO),
3735 .monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO),
3736 .max_pdu_size = cpu_to_le16(chan->imtu),
3737 .txwin_size = min_t(u16, chan->ack_win, L2CAP_DEFAULT_TX_WINDOW),
3738 };
3739
3740 BT_DBG("chan %p, rsp %p, len %d", chan, rsp, len);
3741
3742 if ((chan->mode != L2CAP_MODE_ERTM) && (chan->mode != L2CAP_MODE_STREAMING))
3743 return;
3744
3745 while (len >= L2CAP_CONF_OPT_SIZE) {
3746 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
3747 if (len < 0)
3748 break;
3749
3750 switch (type) {
3751 case L2CAP_CONF_RFC:
3752 if (olen != sizeof(rfc))
3753 break;
3754 memcpy(&rfc, (void *)val, olen);
3755 break;
3756 case L2CAP_CONF_EWS:
3757 if (olen != 2)
3758 break;
3759 txwin_ext = val;
3760 break;
3761 }
3762 }
3763
3764 switch (rfc.mode) {
3765 case L2CAP_MODE_ERTM:
3766 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
3767 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
3768 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3769 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
3770 chan->ack_win = min_t(u16, chan->ack_win, txwin_ext);
3771 else
3772 chan->ack_win = min_t(u16, chan->ack_win,
3773 rfc.txwin_size);
3774 break;
3775 case L2CAP_MODE_STREAMING:
3776 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3777 }
3778 }
3779
3780 static inline int l2cap_command_rej(struct l2cap_conn *conn,
3781 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
3782 u8 *data)
3783 {
3784 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
3785
3786 if (cmd_len < sizeof(*rej))
3787 return -EPROTO;
3788
3789 if (rej->reason != L2CAP_REJ_NOT_UNDERSTOOD)
3790 return 0;
3791
3792 if ((conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) &&
3793 cmd->ident == conn->info_ident) {
3794 cancel_delayed_work(&conn->info_timer);
3795
3796 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
3797 conn->info_ident = 0;
3798
3799 l2cap_conn_start(conn);
3800 }
3801
3802 return 0;
3803 }
3804
3805 static struct l2cap_chan *l2cap_connect(struct l2cap_conn *conn,
3806 struct l2cap_cmd_hdr *cmd,
3807 u8 *data, u8 rsp_code, u8 amp_id)
3808 {
3809 struct l2cap_conn_req *req = (struct l2cap_conn_req *) data;
3810 struct l2cap_conn_rsp rsp;
3811 struct l2cap_chan *chan = NULL, *pchan;
3812 int result, status = L2CAP_CS_NO_INFO;
3813
3814 u16 dcid = 0, scid = __le16_to_cpu(req->scid);
3815 __le16 psm = req->psm;
3816
3817 BT_DBG("psm 0x%2.2x scid 0x%4.4x", __le16_to_cpu(psm), scid);
3818
3819 /* Check if we have socket listening on psm */
3820 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
3821 &conn->hcon->dst, ACL_LINK);
3822 if (!pchan) {
3823 result = L2CAP_CR_BAD_PSM;
3824 goto sendresp;
3825 }
3826
3827 mutex_lock(&conn->chan_lock);
3828 l2cap_chan_lock(pchan);
3829
3830 /* Check if the ACL is secure enough (if not SDP) */
3831 if (psm != cpu_to_le16(L2CAP_PSM_SDP) &&
3832 !hci_conn_check_link_mode(conn->hcon)) {
3833 conn->disc_reason = HCI_ERROR_AUTH_FAILURE;
3834 result = L2CAP_CR_SEC_BLOCK;
3835 goto response;
3836 }
3837
3838 result = L2CAP_CR_NO_MEM;
3839
3840 /* Check for valid dynamic CID range (as per Erratum 3253) */
3841 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) {
3842 result = L2CAP_CR_INVALID_SCID;
3843 goto response;
3844 }
3845
3846 /* Check if we already have channel with that dcid */
3847 if (__l2cap_get_chan_by_dcid(conn, scid)) {
3848 result = L2CAP_CR_SCID_IN_USE;
3849 goto response;
3850 }
3851
3852 chan = pchan->ops->new_connection(pchan);
3853 if (!chan)
3854 goto response;
3855
3856 /* For certain devices (ex: HID mouse), support for authentication,
3857 * pairing and bonding is optional. For such devices, inorder to avoid
3858 * the ACL alive for too long after L2CAP disconnection, reset the ACL
3859 * disc_timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect.
3860 */
3861 conn->hcon->disc_timeout = HCI_DISCONN_TIMEOUT;
3862
3863 bacpy(&chan->src, &conn->hcon->src);
3864 bacpy(&chan->dst, &conn->hcon->dst);
3865 chan->src_type = bdaddr_src_type(conn->hcon);
3866 chan->dst_type = bdaddr_dst_type(conn->hcon);
3867 chan->psm = psm;
3868 chan->dcid = scid;
3869 chan->local_amp_id = amp_id;
3870
3871 __l2cap_chan_add(conn, chan);
3872
3873 dcid = chan->scid;
3874
3875 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
3876
3877 chan->ident = cmd->ident;
3878
3879 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) {
3880 if (l2cap_chan_check_security(chan, false)) {
3881 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
3882 l2cap_state_change(chan, BT_CONNECT2);
3883 result = L2CAP_CR_PEND;
3884 status = L2CAP_CS_AUTHOR_PEND;
3885 chan->ops->defer(chan);
3886 } else {
3887 /* Force pending result for AMP controllers.
3888 * The connection will succeed after the
3889 * physical link is up.
3890 */
3891 if (amp_id == AMP_ID_BREDR) {
3892 l2cap_state_change(chan, BT_CONFIG);
3893 result = L2CAP_CR_SUCCESS;
3894 } else {
3895 l2cap_state_change(chan, BT_CONNECT2);
3896 result = L2CAP_CR_PEND;
3897 }
3898 status = L2CAP_CS_NO_INFO;
3899 }
3900 } else {
3901 l2cap_state_change(chan, BT_CONNECT2);
3902 result = L2CAP_CR_PEND;
3903 status = L2CAP_CS_AUTHEN_PEND;
3904 }
3905 } else {
3906 l2cap_state_change(chan, BT_CONNECT2);
3907 result = L2CAP_CR_PEND;
3908 status = L2CAP_CS_NO_INFO;
3909 }
3910
3911 response:
3912 l2cap_chan_unlock(pchan);
3913 mutex_unlock(&conn->chan_lock);
3914 l2cap_chan_put(pchan);
3915
3916 sendresp:
3917 rsp.scid = cpu_to_le16(scid);
3918 rsp.dcid = cpu_to_le16(dcid);
3919 rsp.result = cpu_to_le16(result);
3920 rsp.status = cpu_to_le16(status);
3921 l2cap_send_cmd(conn, cmd->ident, rsp_code, sizeof(rsp), &rsp);
3922
3923 if (result == L2CAP_CR_PEND && status == L2CAP_CS_NO_INFO) {
3924 struct l2cap_info_req info;
3925 info.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
3926
3927 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
3928 conn->info_ident = l2cap_get_ident(conn);
3929
3930 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
3931
3932 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
3933 sizeof(info), &info);
3934 }
3935
3936 if (chan && !test_bit(CONF_REQ_SENT, &chan->conf_state) &&
3937 result == L2CAP_CR_SUCCESS) {
3938 u8 buf[128];
3939 set_bit(CONF_REQ_SENT, &chan->conf_state);
3940 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
3941 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
3942 chan->num_conf_req++;
3943 }
3944
3945 return chan;
3946 }
3947
3948 static int l2cap_connect_req(struct l2cap_conn *conn,
3949 struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
3950 {
3951 struct hci_dev *hdev = conn->hcon->hdev;
3952 struct hci_conn *hcon = conn->hcon;
3953
3954 if (cmd_len < sizeof(struct l2cap_conn_req))
3955 return -EPROTO;
3956
3957 hci_dev_lock(hdev);
3958 if (hci_dev_test_flag(hdev, HCI_MGMT) &&
3959 !test_and_set_bit(HCI_CONN_MGMT_CONNECTED, &hcon->flags))
3960 mgmt_device_connected(hdev, hcon, 0, NULL, 0);
3961 hci_dev_unlock(hdev);
3962
3963 l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP, 0);
3964 return 0;
3965 }
3966
3967 static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
3968 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
3969 u8 *data)
3970 {
3971 struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data;
3972 u16 scid, dcid, result, status;
3973 struct l2cap_chan *chan;
3974 u8 req[128];
3975 int err;
3976
3977 if (cmd_len < sizeof(*rsp))
3978 return -EPROTO;
3979
3980 scid = __le16_to_cpu(rsp->scid);
3981 dcid = __le16_to_cpu(rsp->dcid);
3982 result = __le16_to_cpu(rsp->result);
3983 status = __le16_to_cpu(rsp->status);
3984
3985 BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x",
3986 dcid, scid, result, status);
3987
3988 mutex_lock(&conn->chan_lock);
3989
3990 if (scid) {
3991 chan = __l2cap_get_chan_by_scid(conn, scid);
3992 if (!chan) {
3993 err = -EBADSLT;
3994 goto unlock;
3995 }
3996 } else {
3997 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
3998 if (!chan) {
3999 err = -EBADSLT;
4000 goto unlock;
4001 }
4002 }
4003
4004 err = 0;
4005
4006 l2cap_chan_lock(chan);
4007
4008 switch (result) {
4009 case L2CAP_CR_SUCCESS:
4010 l2cap_state_change(chan, BT_CONFIG);
4011 chan->ident = 0;
4012 chan->dcid = dcid;
4013 clear_bit(CONF_CONNECT_PEND, &chan->conf_state);
4014
4015 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
4016 break;
4017
4018 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4019 l2cap_build_conf_req(chan, req, sizeof(req)), req);
4020 chan->num_conf_req++;
4021 break;
4022
4023 case L2CAP_CR_PEND:
4024 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
4025 break;
4026
4027 default:
4028 l2cap_chan_del(chan, ECONNREFUSED);
4029 break;
4030 }
4031
4032 l2cap_chan_unlock(chan);
4033
4034 unlock:
4035 mutex_unlock(&conn->chan_lock);
4036
4037 return err;
4038 }
4039
4040 static inline void set_default_fcs(struct l2cap_chan *chan)
4041 {
4042 /* FCS is enabled only in ERTM or streaming mode, if one or both
4043 * sides request it.
4044 */
4045 if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING)
4046 chan->fcs = L2CAP_FCS_NONE;
4047 else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state))
4048 chan->fcs = L2CAP_FCS_CRC16;
4049 }
4050
4051 static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data,
4052 u8 ident, u16 flags)
4053 {
4054 struct l2cap_conn *conn = chan->conn;
4055
4056 BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident,
4057 flags);
4058
4059 clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
4060 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
4061
4062 l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP,
4063 l2cap_build_conf_rsp(chan, data,
4064 L2CAP_CONF_SUCCESS, flags), data);
4065 }
4066
4067 static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident,
4068 u16 scid, u16 dcid)
4069 {
4070 struct l2cap_cmd_rej_cid rej;
4071
4072 rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID);
4073 rej.scid = __cpu_to_le16(scid);
4074 rej.dcid = __cpu_to_le16(dcid);
4075
4076 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
4077 }
4078
4079 static inline int l2cap_config_req(struct l2cap_conn *conn,
4080 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4081 u8 *data)
4082 {
4083 struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
4084 u16 dcid, flags;
4085 u8 rsp[64];
4086 struct l2cap_chan *chan;
4087 int len, err = 0;
4088
4089 if (cmd_len < sizeof(*req))
4090 return -EPROTO;
4091
4092 dcid = __le16_to_cpu(req->dcid);
4093 flags = __le16_to_cpu(req->flags);
4094
4095 BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags);
4096
4097 chan = l2cap_get_chan_by_scid(conn, dcid);
4098 if (!chan) {
4099 cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0);
4100 return 0;
4101 }
4102
4103 if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2) {
4104 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
4105 chan->dcid);
4106 goto unlock;
4107 }
4108
4109 /* Reject if config buffer is too small. */
4110 len = cmd_len - sizeof(*req);
4111 if (chan->conf_len + len > sizeof(chan->conf_req)) {
4112 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4113 l2cap_build_conf_rsp(chan, rsp,
4114 L2CAP_CONF_REJECT, flags), rsp);
4115 goto unlock;
4116 }
4117
4118 /* Store config. */
4119 memcpy(chan->conf_req + chan->conf_len, req->data, len);
4120 chan->conf_len += len;
4121
4122 if (flags & L2CAP_CONF_FLAG_CONTINUATION) {
4123 /* Incomplete config. Send empty response. */
4124 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4125 l2cap_build_conf_rsp(chan, rsp,
4126 L2CAP_CONF_SUCCESS, flags), rsp);
4127 goto unlock;
4128 }
4129
4130 /* Complete config. */
4131 len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp));
4132 if (len < 0) {
4133 l2cap_send_disconn_req(chan, ECONNRESET);
4134 goto unlock;
4135 }
4136
4137 chan->ident = cmd->ident;
4138 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp);
4139 chan->num_conf_rsp++;
4140
4141 /* Reset config buffer. */
4142 chan->conf_len = 0;
4143
4144 if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state))
4145 goto unlock;
4146
4147 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
4148 set_default_fcs(chan);
4149
4150 if (chan->mode == L2CAP_MODE_ERTM ||
4151 chan->mode == L2CAP_MODE_STREAMING)
4152 err = l2cap_ertm_init(chan);
4153
4154 if (err < 0)
4155 l2cap_send_disconn_req(chan, -err);
4156 else
4157 l2cap_chan_ready(chan);
4158
4159 goto unlock;
4160 }
4161
4162 if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) {
4163 u8 buf[64];
4164 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4165 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4166 chan->num_conf_req++;
4167 }
4168
4169 /* Got Conf Rsp PENDING from remote side and assume we sent
4170 Conf Rsp PENDING in the code above */
4171 if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) &&
4172 test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4173
4174 /* check compatibility */
4175
4176 /* Send rsp for BR/EDR channel */
4177 if (!chan->hs_hcon)
4178 l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags);
4179 else
4180 chan->ident = cmd->ident;
4181 }
4182
4183 unlock:
4184 l2cap_chan_unlock(chan);
4185 return err;
4186 }
4187
4188 static inline int l2cap_config_rsp(struct l2cap_conn *conn,
4189 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4190 u8 *data)
4191 {
4192 struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data;
4193 u16 scid, flags, result;
4194 struct l2cap_chan *chan;
4195 int len = cmd_len - sizeof(*rsp);
4196 int err = 0;
4197
4198 if (cmd_len < sizeof(*rsp))
4199 return -EPROTO;
4200
4201 scid = __le16_to_cpu(rsp->scid);
4202 flags = __le16_to_cpu(rsp->flags);
4203 result = __le16_to_cpu(rsp->result);
4204
4205 BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags,
4206 result, len);
4207
4208 chan = l2cap_get_chan_by_scid(conn, scid);
4209 if (!chan)
4210 return 0;
4211
4212 switch (result) {
4213 case L2CAP_CONF_SUCCESS:
4214 l2cap_conf_rfc_get(chan, rsp->data, len);
4215 clear_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4216 break;
4217
4218 case L2CAP_CONF_PENDING:
4219 set_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4220
4221 if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4222 char buf[64];
4223
4224 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4225 buf, sizeof(buf), &result);
4226 if (len < 0) {
4227 l2cap_send_disconn_req(chan, ECONNRESET);
4228 goto done;
4229 }
4230
4231 if (!chan->hs_hcon) {
4232 l2cap_send_efs_conf_rsp(chan, buf, cmd->ident,
4233 0);
4234 } else {
4235 if (l2cap_check_efs(chan)) {
4236 amp_create_logical_link(chan);
4237 chan->ident = cmd->ident;
4238 }
4239 }
4240 }
4241 goto done;
4242
4243 case L2CAP_CONF_UNACCEPT:
4244 if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) {
4245 char req[64];
4246
4247 if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) {
4248 l2cap_send_disconn_req(chan, ECONNRESET);
4249 goto done;
4250 }
4251
4252 /* throw out any old stored conf requests */
4253 result = L2CAP_CONF_SUCCESS;
4254 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4255 req, sizeof(req), &result);
4256 if (len < 0) {
4257 l2cap_send_disconn_req(chan, ECONNRESET);
4258 goto done;
4259 }
4260
4261 l2cap_send_cmd(conn, l2cap_get_ident(conn),
4262 L2CAP_CONF_REQ, len, req);
4263 chan->num_conf_req++;
4264 if (result != L2CAP_CONF_SUCCESS)
4265 goto done;
4266 break;
4267 }
4268 /* fall through */
4269
4270 default:
4271 l2cap_chan_set_err(chan, ECONNRESET);
4272
4273 __set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT);
4274 l2cap_send_disconn_req(chan, ECONNRESET);
4275 goto done;
4276 }
4277
4278 if (flags & L2CAP_CONF_FLAG_CONTINUATION)
4279 goto done;
4280
4281 set_bit(CONF_INPUT_DONE, &chan->conf_state);
4282
4283 if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) {
4284 set_default_fcs(chan);
4285
4286 if (chan->mode == L2CAP_MODE_ERTM ||
4287 chan->mode == L2CAP_MODE_STREAMING)
4288 err = l2cap_ertm_init(chan);
4289
4290 if (err < 0)
4291 l2cap_send_disconn_req(chan, -err);
4292 else
4293 l2cap_chan_ready(chan);
4294 }
4295
4296 done:
4297 l2cap_chan_unlock(chan);
4298 return err;
4299 }
4300
4301 static inline int l2cap_disconnect_req(struct l2cap_conn *conn,
4302 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4303 u8 *data)
4304 {
4305 struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data;
4306 struct l2cap_disconn_rsp rsp;
4307 u16 dcid, scid;
4308 struct l2cap_chan *chan;
4309
4310 if (cmd_len != sizeof(*req))
4311 return -EPROTO;
4312
4313 scid = __le16_to_cpu(req->scid);
4314 dcid = __le16_to_cpu(req->dcid);
4315
4316 BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
4317
4318 mutex_lock(&conn->chan_lock);
4319
4320 chan = __l2cap_get_chan_by_scid(conn, dcid);
4321 if (!chan) {
4322 mutex_unlock(&conn->chan_lock);
4323 cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid);
4324 return 0;
4325 }
4326
4327 l2cap_chan_lock(chan);
4328
4329 rsp.dcid = cpu_to_le16(chan->scid);
4330 rsp.scid = cpu_to_le16(chan->dcid);
4331 l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
4332
4333 chan->ops->set_shutdown(chan);
4334
4335 l2cap_chan_hold(chan);
4336 l2cap_chan_del(chan, ECONNRESET);
4337
4338 l2cap_chan_unlock(chan);
4339
4340 chan->ops->close(chan);
4341 l2cap_chan_put(chan);
4342
4343 mutex_unlock(&conn->chan_lock);
4344
4345 return 0;
4346 }
4347
4348 static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,
4349 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4350 u8 *data)
4351 {
4352 struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data;
4353 u16 dcid, scid;
4354 struct l2cap_chan *chan;
4355
4356 if (cmd_len != sizeof(*rsp))
4357 return -EPROTO;
4358
4359 scid = __le16_to_cpu(rsp->scid);
4360 dcid = __le16_to_cpu(rsp->dcid);
4361
4362 BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
4363
4364 mutex_lock(&conn->chan_lock);
4365
4366 chan = __l2cap_get_chan_by_scid(conn, scid);
4367 if (!chan) {
4368 mutex_unlock(&conn->chan_lock);
4369 return 0;
4370 }
4371
4372 l2cap_chan_lock(chan);
4373
4374 l2cap_chan_hold(chan);
4375 l2cap_chan_del(chan, 0);
4376
4377 l2cap_chan_unlock(chan);
4378
4379 chan->ops->close(chan);
4380 l2cap_chan_put(chan);
4381
4382 mutex_unlock(&conn->chan_lock);
4383
4384 return 0;
4385 }
4386
4387 static inline int l2cap_information_req(struct l2cap_conn *conn,
4388 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4389 u8 *data)
4390 {
4391 struct l2cap_info_req *req = (struct l2cap_info_req *) data;
4392 u16 type;
4393
4394 if (cmd_len != sizeof(*req))
4395 return -EPROTO;
4396
4397 type = __le16_to_cpu(req->type);
4398
4399 BT_DBG("type 0x%4.4x", type);
4400
4401 if (type == L2CAP_IT_FEAT_MASK) {
4402 u8 buf[8];
4403 u32 feat_mask = l2cap_feat_mask;
4404 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4405 rsp->type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
4406 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4407 if (!disable_ertm)
4408 feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING
4409 | L2CAP_FEAT_FCS;
4410 if (conn->local_fixed_chan & L2CAP_FC_A2MP)
4411 feat_mask |= L2CAP_FEAT_EXT_FLOW
4412 | L2CAP_FEAT_EXT_WINDOW;
4413
4414 put_unaligned_le32(feat_mask, rsp->data);
4415 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4416 buf);
4417 } else if (type == L2CAP_IT_FIXED_CHAN) {
4418 u8 buf[12];
4419 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4420
4421 rsp->type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4422 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4423 rsp->data[0] = conn->local_fixed_chan;
4424 memset(rsp->data + 1, 0, 7);
4425 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4426 buf);
4427 } else {
4428 struct l2cap_info_rsp rsp;
4429 rsp.type = cpu_to_le16(type);
4430 rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP);
4431 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp),
4432 &rsp);
4433 }
4434
4435 return 0;
4436 }
4437
4438 static inline int l2cap_information_rsp(struct l2cap_conn *conn,
4439 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4440 u8 *data)
4441 {
4442 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data;
4443 u16 type, result;
4444
4445 if (cmd_len < sizeof(*rsp))
4446 return -EPROTO;
4447
4448 type = __le16_to_cpu(rsp->type);
4449 result = __le16_to_cpu(rsp->result);
4450
4451 BT_DBG("type 0x%4.4x result 0x%2.2x", type, result);
4452
4453 /* L2CAP Info req/rsp are unbound to channels, add extra checks */
4454 if (cmd->ident != conn->info_ident ||
4455 conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
4456 return 0;
4457
4458 cancel_delayed_work(&conn->info_timer);
4459
4460 if (result != L2CAP_IR_SUCCESS) {
4461 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4462 conn->info_ident = 0;
4463
4464 l2cap_conn_start(conn);
4465
4466 return 0;
4467 }
4468
4469 switch (type) {
4470 case L2CAP_IT_FEAT_MASK:
4471 conn->feat_mask = get_unaligned_le32(rsp->data);
4472
4473 if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) {
4474 struct l2cap_info_req req;
4475 req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4476
4477 conn->info_ident = l2cap_get_ident(conn);
4478
4479 l2cap_send_cmd(conn, conn->info_ident,
4480 L2CAP_INFO_REQ, sizeof(req), &req);
4481 } else {
4482 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4483 conn->info_ident = 0;
4484
4485 l2cap_conn_start(conn);
4486 }
4487 break;
4488
4489 case L2CAP_IT_FIXED_CHAN:
4490 conn->remote_fixed_chan = rsp->data[0];
4491 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4492 conn->info_ident = 0;
4493
4494 l2cap_conn_start(conn);
4495 break;
4496 }
4497
4498 return 0;
4499 }
4500
4501 static int l2cap_create_channel_req(struct l2cap_conn *conn,
4502 struct l2cap_cmd_hdr *cmd,
4503 u16 cmd_len, void *data)
4504 {
4505 struct l2cap_create_chan_req *req = data;
4506 struct l2cap_create_chan_rsp rsp;
4507 struct l2cap_chan *chan;
4508 struct hci_dev *hdev;
4509 u16 psm, scid;
4510
4511 if (cmd_len != sizeof(*req))
4512 return -EPROTO;
4513
4514 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
4515 return -EINVAL;
4516
4517 psm = le16_to_cpu(req->psm);
4518 scid = le16_to_cpu(req->scid);
4519
4520 BT_DBG("psm 0x%2.2x, scid 0x%4.4x, amp_id %d", psm, scid, req->amp_id);
4521
4522 /* For controller id 0 make BR/EDR connection */
4523 if (req->amp_id == AMP_ID_BREDR) {
4524 l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP,
4525 req->amp_id);
4526 return 0;
4527 }
4528
4529 /* Validate AMP controller id */
4530 hdev = hci_dev_get(req->amp_id);
4531 if (!hdev)
4532 goto error;
4533
4534 if (hdev->dev_type != HCI_AMP || !test_bit(HCI_UP, &hdev->flags)) {
4535 hci_dev_put(hdev);
4536 goto error;
4537 }
4538
4539 chan = l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP,
4540 req->amp_id);
4541 if (chan) {
4542 struct amp_mgr *mgr = conn->hcon->amp_mgr;
4543 struct hci_conn *hs_hcon;
4544
4545 hs_hcon = hci_conn_hash_lookup_ba(hdev, AMP_LINK,
4546 &conn->hcon->dst);
4547 if (!hs_hcon) {
4548 hci_dev_put(hdev);
4549 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
4550 chan->dcid);
4551 return 0;
4552 }
4553
4554 BT_DBG("mgr %p bredr_chan %p hs_hcon %p", mgr, chan, hs_hcon);
4555
4556 mgr->bredr_chan = chan;
4557 chan->hs_hcon = hs_hcon;
4558 chan->fcs = L2CAP_FCS_NONE;
4559 conn->mtu = hdev->block_mtu;
4560 }
4561
4562 hci_dev_put(hdev);
4563
4564 return 0;
4565
4566 error:
4567 rsp.dcid = 0;
4568 rsp.scid = cpu_to_le16(scid);
4569 rsp.result = cpu_to_le16(L2CAP_CR_BAD_AMP);
4570 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
4571
4572 l2cap_send_cmd(conn, cmd->ident, L2CAP_CREATE_CHAN_RSP,
4573 sizeof(rsp), &rsp);
4574
4575 return 0;
4576 }
4577
4578 static void l2cap_send_move_chan_req(struct l2cap_chan *chan, u8 dest_amp_id)
4579 {
4580 struct l2cap_move_chan_req req;
4581 u8 ident;
4582
4583 BT_DBG("chan %p, dest_amp_id %d", chan, dest_amp_id);
4584
4585 ident = l2cap_get_ident(chan->conn);
4586 chan->ident = ident;
4587
4588 req.icid = cpu_to_le16(chan->scid);
4589 req.dest_amp_id = dest_amp_id;
4590
4591 l2cap_send_cmd(chan->conn, ident, L2CAP_MOVE_CHAN_REQ, sizeof(req),
4592 &req);
4593
4594 __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
4595 }
4596
4597 static void l2cap_send_move_chan_rsp(struct l2cap_chan *chan, u16 result)
4598 {
4599 struct l2cap_move_chan_rsp rsp;
4600
4601 BT_DBG("chan %p, result 0x%4.4x", chan, result);
4602
4603 rsp.icid = cpu_to_le16(chan->dcid);
4604 rsp.result = cpu_to_le16(result);
4605
4606 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_RSP,
4607 sizeof(rsp), &rsp);
4608 }
4609
4610 static void l2cap_send_move_chan_cfm(struct l2cap_chan *chan, u16 result)
4611 {
4612 struct l2cap_move_chan_cfm cfm;
4613
4614 BT_DBG("chan %p, result 0x%4.4x", chan, result);
4615
4616 chan->ident = l2cap_get_ident(chan->conn);
4617
4618 cfm.icid = cpu_to_le16(chan->scid);
4619 cfm.result = cpu_to_le16(result);
4620
4621 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_CFM,
4622 sizeof(cfm), &cfm);
4623
4624 __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
4625 }
4626
4627 static void l2cap_send_move_chan_cfm_icid(struct l2cap_conn *conn, u16 icid)
4628 {
4629 struct l2cap_move_chan_cfm cfm;
4630
4631 BT_DBG("conn %p, icid 0x%4.4x", conn, icid);
4632
4633 cfm.icid = cpu_to_le16(icid);
4634 cfm.result = cpu_to_le16(L2CAP_MC_UNCONFIRMED);
4635
4636 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_MOVE_CHAN_CFM,
4637 sizeof(cfm), &cfm);
4638 }
4639
4640 static void l2cap_send_move_chan_cfm_rsp(struct l2cap_conn *conn, u8 ident,
4641 u16 icid)
4642 {
4643 struct l2cap_move_chan_cfm_rsp rsp;
4644
4645 BT_DBG("icid 0x%4.4x", icid);
4646
4647 rsp.icid = cpu_to_le16(icid);
4648 l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_CFM_RSP, sizeof(rsp), &rsp);
4649 }
4650
4651 static void __release_logical_link(struct l2cap_chan *chan)
4652 {
4653 chan->hs_hchan = NULL;
4654 chan->hs_hcon = NULL;
4655
4656 /* Placeholder - release the logical link */
4657 }
4658
4659 static void l2cap_logical_fail(struct l2cap_chan *chan)
4660 {
4661 /* Logical link setup failed */
4662 if (chan->state != BT_CONNECTED) {
4663 /* Create channel failure, disconnect */
4664 l2cap_send_disconn_req(chan, ECONNRESET);
4665 return;
4666 }
4667
4668 switch (chan->move_role) {
4669 case L2CAP_MOVE_ROLE_RESPONDER:
4670 l2cap_move_done(chan);
4671 l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_SUPP);
4672 break;
4673 case L2CAP_MOVE_ROLE_INITIATOR:
4674 if (chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_COMP ||
4675 chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_CFM) {
4676 /* Remote has only sent pending or
4677 * success responses, clean up
4678 */
4679 l2cap_move_done(chan);
4680 }
4681
4682 /* Other amp move states imply that the move
4683 * has already aborted
4684 */
4685 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
4686 break;
4687 }
4688 }
4689
4690 static void l2cap_logical_finish_create(struct l2cap_chan *chan,
4691 struct hci_chan *hchan)
4692 {
4693 struct l2cap_conf_rsp rsp;
4694
4695 chan->hs_hchan = hchan;
4696 chan->hs_hcon->l2cap_data = chan->conn;
4697
4698 l2cap_send_efs_conf_rsp(chan, &rsp, chan->ident, 0);
4699
4700 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
4701 int err;
4702
4703 set_default_fcs(chan);
4704
4705 err = l2cap_ertm_init(chan);
4706 if (err < 0)
4707 l2cap_send_disconn_req(chan, -err);
4708 else
4709 l2cap_chan_ready(chan);
4710 }
4711 }
4712
4713 static void l2cap_logical_finish_move(struct l2cap_chan *chan,
4714 struct hci_chan *hchan)
4715 {
4716 chan->hs_hcon = hchan->conn;
4717 chan->hs_hcon->l2cap_data = chan->conn;
4718
4719 BT_DBG("move_state %d", chan->move_state);
4720
4721 switch (chan->move_state) {
4722 case L2CAP_MOVE_WAIT_LOGICAL_COMP:
4723 /* Move confirm will be sent after a success
4724 * response is received
4725 */
4726 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
4727 break;
4728 case L2CAP_MOVE_WAIT_LOGICAL_CFM:
4729 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
4730 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
4731 } else if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
4732 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
4733 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
4734 } else if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) {
4735 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
4736 l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS);
4737 }
4738 break;
4739 default:
4740 /* Move was not in expected state, free the channel */
4741 __release_logical_link(chan);
4742
4743 chan->move_state = L2CAP_MOVE_STABLE;
4744 }
4745 }
4746
4747 /* Call with chan locked */
4748 void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan,
4749 u8 status)
4750 {
4751 BT_DBG("chan %p, hchan %p, status %d", chan, hchan, status);
4752
4753 if (status) {
4754 l2cap_logical_fail(chan);
4755 __release_logical_link(chan);
4756 return;
4757 }
4758
4759 if (chan->state != BT_CONNECTED) {
4760 /* Ignore logical link if channel is on BR/EDR */
4761 if (chan->local_amp_id != AMP_ID_BREDR)
4762 l2cap_logical_finish_create(chan, hchan);
4763 } else {
4764 l2cap_logical_finish_move(chan, hchan);
4765 }
4766 }
4767
4768 void l2cap_move_start(struct l2cap_chan *chan)
4769 {
4770 BT_DBG("chan %p", chan);
4771
4772 if (chan->local_amp_id == AMP_ID_BREDR) {
4773 if (chan->chan_policy != BT_CHANNEL_POLICY_AMP_PREFERRED)
4774 return;
4775 chan->move_role = L2CAP_MOVE_ROLE_INITIATOR;
4776 chan->move_state = L2CAP_MOVE_WAIT_PREPARE;
4777 /* Placeholder - start physical link setup */
4778 } else {
4779 chan->move_role = L2CAP_MOVE_ROLE_INITIATOR;
4780 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
4781 chan->move_id = 0;
4782 l2cap_move_setup(chan);
4783 l2cap_send_move_chan_req(chan, 0);
4784 }
4785 }
4786
4787 static void l2cap_do_create(struct l2cap_chan *chan, int result,
4788 u8 local_amp_id, u8 remote_amp_id)
4789 {
4790 BT_DBG("chan %p state %s %u -> %u", chan, state_to_string(chan->state),
4791 local_amp_id, remote_amp_id);
4792
4793 chan->fcs = L2CAP_FCS_NONE;
4794
4795 /* Outgoing channel on AMP */
4796 if (chan->state == BT_CONNECT) {
4797 if (result == L2CAP_CR_SUCCESS) {
4798 chan->local_amp_id = local_amp_id;
4799 l2cap_send_create_chan_req(chan, remote_amp_id);
4800 } else {
4801 /* Revert to BR/EDR connect */
4802 l2cap_send_conn_req(chan);
4803 }
4804
4805 return;
4806 }
4807
4808 /* Incoming channel on AMP */
4809 if (__l2cap_no_conn_pending(chan)) {
4810 struct l2cap_conn_rsp rsp;
4811 char buf[128];
4812 rsp.scid = cpu_to_le16(chan->dcid);
4813 rsp.dcid = cpu_to_le16(chan->scid);
4814
4815 if (result == L2CAP_CR_SUCCESS) {
4816 /* Send successful response */
4817 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
4818 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
4819 } else {
4820 /* Send negative response */
4821 rsp.result = cpu_to_le16(L2CAP_CR_NO_MEM);
4822 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
4823 }
4824
4825 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_RSP,
4826 sizeof(rsp), &rsp);
4827
4828 if (result == L2CAP_CR_SUCCESS) {
4829 l2cap_state_change(chan, BT_CONFIG);
4830 set_bit(CONF_REQ_SENT, &chan->conf_state);
4831 l2cap_send_cmd(chan->conn, l2cap_get_ident(chan->conn),
4832 L2CAP_CONF_REQ,
4833 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4834 chan->num_conf_req++;
4835 }
4836 }
4837 }
4838
4839 static void l2cap_do_move_initiate(struct l2cap_chan *chan, u8 local_amp_id,
4840 u8 remote_amp_id)
4841 {
4842 l2cap_move_setup(chan);
4843 chan->move_id = local_amp_id;
4844 chan->move_state = L2CAP_MOVE_WAIT_RSP;
4845
4846 l2cap_send_move_chan_req(chan, remote_amp_id);
4847 }
4848
4849 static void l2cap_do_move_respond(struct l2cap_chan *chan, int result)
4850 {
4851 struct hci_chan *hchan = NULL;
4852
4853 /* Placeholder - get hci_chan for logical link */
4854
4855 if (hchan) {
4856 if (hchan->state == BT_CONNECTED) {
4857 /* Logical link is ready to go */
4858 chan->hs_hcon = hchan->conn;
4859 chan->hs_hcon->l2cap_data = chan->conn;
4860 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
4861 l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS);
4862
4863 l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
4864 } else {
4865 /* Wait for logical link to be ready */
4866 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
4867 }
4868 } else {
4869 /* Logical link not available */
4870 l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_ALLOWED);
4871 }
4872 }
4873
4874 static void l2cap_do_move_cancel(struct l2cap_chan *chan, int result)
4875 {
4876 if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) {
4877 u8 rsp_result;
4878 if (result == -EINVAL)
4879 rsp_result = L2CAP_MR_BAD_ID;
4880 else
4881 rsp_result = L2CAP_MR_NOT_ALLOWED;
4882
4883 l2cap_send_move_chan_rsp(chan, rsp_result);
4884 }
4885
4886 chan->move_role = L2CAP_MOVE_ROLE_NONE;
4887 chan->move_state = L2CAP_MOVE_STABLE;
4888
4889 /* Restart data transmission */
4890 l2cap_ertm_send(chan);
4891 }
4892
4893 /* Invoke with locked chan */
4894 void __l2cap_physical_cfm(struct l2cap_chan *chan, int result)
4895 {
4896 u8 local_amp_id = chan->local_amp_id;
4897 u8 remote_amp_id = chan->remote_amp_id;
4898
4899 BT_DBG("chan %p, result %d, local_amp_id %d, remote_amp_id %d",
4900 chan, result, local_amp_id, remote_amp_id);
4901
4902 if (chan->state == BT_DISCONN || chan->state == BT_CLOSED) {
4903 l2cap_chan_unlock(chan);
4904 return;
4905 }
4906
4907 if (chan->state != BT_CONNECTED) {
4908 l2cap_do_create(chan, result, local_amp_id, remote_amp_id);
4909 } else if (result != L2CAP_MR_SUCCESS) {
4910 l2cap_do_move_cancel(chan, result);
4911 } else {
4912 switch (chan->move_role) {
4913 case L2CAP_MOVE_ROLE_INITIATOR:
4914 l2cap_do_move_initiate(chan, local_amp_id,
4915 remote_amp_id);
4916 break;
4917 case L2CAP_MOVE_ROLE_RESPONDER:
4918 l2cap_do_move_respond(chan, result);
4919 break;
4920 default:
4921 l2cap_do_move_cancel(chan, result);
4922 break;
4923 }
4924 }
4925 }
4926
4927 static inline int l2cap_move_channel_req(struct l2cap_conn *conn,
4928 struct l2cap_cmd_hdr *cmd,
4929 u16 cmd_len, void *data)
4930 {
4931 struct l2cap_move_chan_req *req = data;
4932 struct l2cap_move_chan_rsp rsp;
4933 struct l2cap_chan *chan;
4934 u16 icid = 0;
4935 u16 result = L2CAP_MR_NOT_ALLOWED;
4936
4937 if (cmd_len != sizeof(*req))
4938 return -EPROTO;
4939
4940 icid = le16_to_cpu(req->icid);
4941
4942 BT_DBG("icid 0x%4.4x, dest_amp_id %d", icid, req->dest_amp_id);
4943
4944 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
4945 return -EINVAL;
4946
4947 chan = l2cap_get_chan_by_dcid(conn, icid);
4948 if (!chan) {
4949 rsp.icid = cpu_to_le16(icid);
4950 rsp.result = cpu_to_le16(L2CAP_MR_NOT_ALLOWED);
4951 l2cap_send_cmd(conn, cmd->ident, L2CAP_MOVE_CHAN_RSP,
4952 sizeof(rsp), &rsp);
4953 return 0;
4954 }
4955
4956 chan->ident = cmd->ident;
4957
4958 if (chan->scid < L2CAP_CID_DYN_START ||
4959 chan->chan_policy == BT_CHANNEL_POLICY_BREDR_ONLY ||
4960 (chan->mode != L2CAP_MODE_ERTM &&
4961 chan->mode != L2CAP_MODE_STREAMING)) {
4962 result = L2CAP_MR_NOT_ALLOWED;
4963 goto send_move_response;
4964 }
4965
4966 if (chan->local_amp_id == req->dest_amp_id) {
4967 result = L2CAP_MR_SAME_ID;
4968 goto send_move_response;
4969 }
4970
4971 if (req->dest_amp_id != AMP_ID_BREDR) {
4972 struct hci_dev *hdev;
4973 hdev = hci_dev_get(req->dest_amp_id);
4974 if (!hdev || hdev->dev_type != HCI_AMP ||
4975 !test_bit(HCI_UP, &hdev->flags)) {
4976 if (hdev)
4977 hci_dev_put(hdev);
4978
4979 result = L2CAP_MR_BAD_ID;
4980 goto send_move_response;
4981 }
4982 hci_dev_put(hdev);
4983 }
4984
4985 /* Detect a move collision. Only send a collision response
4986 * if this side has "lost", otherwise proceed with the move.
4987 * The winner has the larger bd_addr.
4988 */
4989 if ((__chan_is_moving(chan) ||
4990 chan->move_role != L2CAP_MOVE_ROLE_NONE) &&
4991 bacmp(&conn->hcon->src, &conn->hcon->dst) > 0) {
4992 result = L2CAP_MR_COLLISION;
4993 goto send_move_response;
4994 }
4995
4996 chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
4997 l2cap_move_setup(chan);
4998 chan->move_id = req->dest_amp_id;
4999 icid = chan->dcid;
5000
5001 if (req->dest_amp_id == AMP_ID_BREDR) {
5002 /* Moving to BR/EDR */
5003 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5004 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
5005 result = L2CAP_MR_PEND;
5006 } else {
5007 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
5008 result = L2CAP_MR_SUCCESS;
5009 }
5010 } else {
5011 chan->move_state = L2CAP_MOVE_WAIT_PREPARE;
5012 /* Placeholder - uncomment when amp functions are available */
5013 /*amp_accept_physical(chan, req->dest_amp_id);*/
5014 result = L2CAP_MR_PEND;
5015 }
5016
5017 send_move_response:
5018 l2cap_send_move_chan_rsp(chan, result);
5019
5020 l2cap_chan_unlock(chan);
5021
5022 return 0;
5023 }
5024
5025 static void l2cap_move_continue(struct l2cap_conn *conn, u16 icid, u16 result)
5026 {
5027 struct l2cap_chan *chan;
5028 struct hci_chan *hchan = NULL;
5029
5030 chan = l2cap_get_chan_by_scid(conn, icid);
5031 if (!chan) {
5032 l2cap_send_move_chan_cfm_icid(conn, icid);
5033 return;
5034 }
5035
5036 __clear_chan_timer(chan);
5037 if (result == L2CAP_MR_PEND)
5038 __set_chan_timer(chan, L2CAP_MOVE_ERTX_TIMEOUT);
5039
5040 switch (chan->move_state) {
5041 case L2CAP_MOVE_WAIT_LOGICAL_COMP:
5042 /* Move confirm will be sent when logical link
5043 * is complete.
5044 */
5045 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
5046 break;
5047 case L2CAP_MOVE_WAIT_RSP_SUCCESS:
5048 if (result == L2CAP_MR_PEND) {
5049 break;
5050 } else if (test_bit(CONN_LOCAL_BUSY,
5051 &chan->conn_state)) {
5052 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
5053 } else {
5054 /* Logical link is up or moving to BR/EDR,
5055 * proceed with move
5056 */
5057 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
5058 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
5059 }
5060 break;
5061 case L2CAP_MOVE_WAIT_RSP:
5062 /* Moving to AMP */
5063 if (result == L2CAP_MR_SUCCESS) {
5064 /* Remote is ready, send confirm immediately
5065 * after logical link is ready
5066 */
5067 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
5068 } else {
5069 /* Both logical link and move success
5070 * are required to confirm
5071 */
5072 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_COMP;
5073 }
5074
5075 /* Placeholder - get hci_chan for logical link */
5076 if (!hchan) {
5077 /* Logical link not available */
5078 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5079 break;
5080 }
5081
5082 /* If the logical link is not yet connected, do not
5083 * send confirmation.
5084 */
5085 if (hchan->state != BT_CONNECTED)
5086 break;
5087
5088 /* Logical link is already ready to go */
5089
5090 chan->hs_hcon = hchan->conn;
5091 chan->hs_hcon->l2cap_data = chan->conn;
5092
5093 if (result == L2CAP_MR_SUCCESS) {
5094 /* Can confirm now */
5095 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
5096 } else {
5097 /* Now only need move success
5098 * to confirm
5099 */
5100 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
5101 }
5102
5103 l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
5104 break;
5105 default:
5106 /* Any other amp move state means the move failed. */
5107 chan->move_id = chan->local_amp_id;
5108 l2cap_move_done(chan);
5109 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5110 }
5111
5112 l2cap_chan_unlock(chan);
5113 }
5114
5115 static void l2cap_move_fail(struct l2cap_conn *conn, u8 ident, u16 icid,
5116 u16 result)
5117 {
5118 struct l2cap_chan *chan;
5119
5120 chan = l2cap_get_chan_by_ident(conn, ident);
5121 if (!chan) {
5122 /* Could not locate channel, icid is best guess */
5123 l2cap_send_move_chan_cfm_icid(conn, icid);
5124 return;
5125 }
5126
5127 __clear_chan_timer(chan);
5128
5129 if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
5130 if (result == L2CAP_MR_COLLISION) {
5131 chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
5132 } else {
5133 /* Cleanup - cancel move */
5134 chan->move_id = chan->local_amp_id;
5135 l2cap_move_done(chan);
5136 }
5137 }
5138
5139 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5140
5141 l2cap_chan_unlock(chan);
5142 }
5143
5144 static int l2cap_move_channel_rsp(struct l2cap_conn *conn,
5145 struct l2cap_cmd_hdr *cmd,
5146 u16 cmd_len, void *data)
5147 {
5148 struct l2cap_move_chan_rsp *rsp = data;
5149 u16 icid, result;
5150
5151 if (cmd_len != sizeof(*rsp))
5152 return -EPROTO;
5153
5154 icid = le16_to_cpu(rsp->icid);
5155 result = le16_to_cpu(rsp->result);
5156
5157 BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
5158
5159 if (result == L2CAP_MR_SUCCESS || result == L2CAP_MR_PEND)
5160 l2cap_move_continue(conn, icid, result);
5161 else
5162 l2cap_move_fail(conn, cmd->ident, icid, result);
5163
5164 return 0;
5165 }
5166
5167 static int l2cap_move_channel_confirm(struct l2cap_conn *conn,
5168 struct l2cap_cmd_hdr *cmd,
5169 u16 cmd_len, void *data)
5170 {
5171 struct l2cap_move_chan_cfm *cfm = data;
5172 struct l2cap_chan *chan;
5173 u16 icid, result;
5174
5175 if (cmd_len != sizeof(*cfm))
5176 return -EPROTO;
5177
5178 icid = le16_to_cpu(cfm->icid);
5179 result = le16_to_cpu(cfm->result);
5180
5181 BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
5182
5183 chan = l2cap_get_chan_by_dcid(conn, icid);
5184 if (!chan) {
5185 /* Spec requires a response even if the icid was not found */
5186 l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
5187 return 0;
5188 }
5189
5190 if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM) {
5191 if (result == L2CAP_MC_CONFIRMED) {
5192 chan->local_amp_id = chan->move_id;
5193 if (chan->local_amp_id == AMP_ID_BREDR)
5194 __release_logical_link(chan);
5195 } else {
5196 chan->move_id = chan->local_amp_id;
5197 }
5198
5199 l2cap_move_done(chan);
5200 }
5201
5202 l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
5203
5204 l2cap_chan_unlock(chan);
5205
5206 return 0;
5207 }
5208
5209 static inline int l2cap_move_channel_confirm_rsp(struct l2cap_conn *conn,
5210 struct l2cap_cmd_hdr *cmd,
5211 u16 cmd_len, void *data)
5212 {
5213 struct l2cap_move_chan_cfm_rsp *rsp = data;
5214 struct l2cap_chan *chan;
5215 u16 icid;
5216
5217 if (cmd_len != sizeof(*rsp))
5218 return -EPROTO;
5219
5220 icid = le16_to_cpu(rsp->icid);
5221
5222 BT_DBG("icid 0x%4.4x", icid);
5223
5224 chan = l2cap_get_chan_by_scid(conn, icid);
5225 if (!chan)
5226 return 0;
5227
5228 __clear_chan_timer(chan);
5229
5230 if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM_RSP) {
5231 chan->local_amp_id = chan->move_id;
5232
5233 if (chan->local_amp_id == AMP_ID_BREDR && chan->hs_hchan)
5234 __release_logical_link(chan);
5235
5236 l2cap_move_done(chan);
5237 }
5238
5239 l2cap_chan_unlock(chan);
5240
5241 return 0;
5242 }
5243
5244 static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
5245 struct l2cap_cmd_hdr *cmd,
5246 u16 cmd_len, u8 *data)
5247 {
5248 struct hci_conn *hcon = conn->hcon;
5249 struct l2cap_conn_param_update_req *req;
5250 struct l2cap_conn_param_update_rsp rsp;
5251 u16 min, max, latency, to_multiplier;
5252 int err;
5253
5254 if (hcon->role != HCI_ROLE_MASTER)
5255 return -EINVAL;
5256
5257 if (cmd_len != sizeof(struct l2cap_conn_param_update_req))
5258 return -EPROTO;
5259
5260 req = (struct l2cap_conn_param_update_req *) data;
5261 min = __le16_to_cpu(req->min);
5262 max = __le16_to_cpu(req->max);
5263 latency = __le16_to_cpu(req->latency);
5264 to_multiplier = __le16_to_cpu(req->to_multiplier);
5265
5266 BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x",
5267 min, max, latency, to_multiplier);
5268
5269 memset(&rsp, 0, sizeof(rsp));
5270
5271 err = hci_check_conn_params(min, max, latency, to_multiplier);
5272 if (err)
5273 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
5274 else
5275 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED);
5276
5277 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP,
5278 sizeof(rsp), &rsp);
5279
5280 if (!err) {
5281 u8 store_hint;
5282
5283 store_hint = hci_le_conn_update(hcon, min, max, latency,
5284 to_multiplier);
5285 mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type,
5286 store_hint, min, max, latency,
5287 to_multiplier);
5288
5289 }
5290
5291 return 0;
5292 }
5293
5294 static int l2cap_le_connect_rsp(struct l2cap_conn *conn,
5295 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5296 u8 *data)
5297 {
5298 struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data;
5299 struct hci_conn *hcon = conn->hcon;
5300 u16 dcid, mtu, mps, credits, result;
5301 struct l2cap_chan *chan;
5302 int err, sec_level;
5303
5304 if (cmd_len < sizeof(*rsp))
5305 return -EPROTO;
5306
5307 dcid = __le16_to_cpu(rsp->dcid);
5308 mtu = __le16_to_cpu(rsp->mtu);
5309 mps = __le16_to_cpu(rsp->mps);
5310 credits = __le16_to_cpu(rsp->credits);
5311 result = __le16_to_cpu(rsp->result);
5312
5313 if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 ||
5314 dcid < L2CAP_CID_DYN_START ||
5315 dcid > L2CAP_CID_LE_DYN_END))
5316 return -EPROTO;
5317
5318 BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x",
5319 dcid, mtu, mps, credits, result);
5320
5321 mutex_lock(&conn->chan_lock);
5322
5323 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
5324 if (!chan) {
5325 err = -EBADSLT;
5326 goto unlock;
5327 }
5328
5329 err = 0;
5330
5331 l2cap_chan_lock(chan);
5332
5333 switch (result) {
5334 case L2CAP_CR_LE_SUCCESS:
5335 if (__l2cap_get_chan_by_dcid(conn, dcid)) {
5336 err = -EBADSLT;
5337 break;
5338 }
5339
5340 chan->ident = 0;
5341 chan->dcid = dcid;
5342 chan->omtu = mtu;
5343 chan->remote_mps = mps;
5344 chan->tx_credits = credits;
5345 l2cap_chan_ready(chan);
5346 break;
5347
5348 case L2CAP_CR_LE_AUTHENTICATION:
5349 case L2CAP_CR_LE_ENCRYPTION:
5350 /* If we already have MITM protection we can't do
5351 * anything.
5352 */
5353 if (hcon->sec_level > BT_SECURITY_MEDIUM) {
5354 l2cap_chan_del(chan, ECONNREFUSED);
5355 break;
5356 }
5357
5358 sec_level = hcon->sec_level + 1;
5359 if (chan->sec_level < sec_level)
5360 chan->sec_level = sec_level;
5361
5362 /* We'll need to send a new Connect Request */
5363 clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags);
5364
5365 smp_conn_security(hcon, chan->sec_level);
5366 break;
5367
5368 default:
5369 l2cap_chan_del(chan, ECONNREFUSED);
5370 break;
5371 }
5372
5373 l2cap_chan_unlock(chan);
5374
5375 unlock:
5376 mutex_unlock(&conn->chan_lock);
5377
5378 return err;
5379 }
5380
5381 static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
5382 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5383 u8 *data)
5384 {
5385 int err = 0;
5386
5387 switch (cmd->code) {
5388 case L2CAP_COMMAND_REJ:
5389 l2cap_command_rej(conn, cmd, cmd_len, data);
5390 break;
5391
5392 case L2CAP_CONN_REQ:
5393 err = l2cap_connect_req(conn, cmd, cmd_len, data);
5394 break;
5395
5396 case L2CAP_CONN_RSP:
5397 case L2CAP_CREATE_CHAN_RSP:
5398 l2cap_connect_create_rsp(conn, cmd, cmd_len, data);
5399 break;
5400
5401 case L2CAP_CONF_REQ:
5402 err = l2cap_config_req(conn, cmd, cmd_len, data);
5403 break;
5404
5405 case L2CAP_CONF_RSP:
5406 l2cap_config_rsp(conn, cmd, cmd_len, data);
5407 break;
5408
5409 case L2CAP_DISCONN_REQ:
5410 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
5411 break;
5412
5413 case L2CAP_DISCONN_RSP:
5414 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
5415 break;
5416
5417 case L2CAP_ECHO_REQ:
5418 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data);
5419 break;
5420
5421 case L2CAP_ECHO_RSP:
5422 break;
5423
5424 case L2CAP_INFO_REQ:
5425 err = l2cap_information_req(conn, cmd, cmd_len, data);
5426 break;
5427
5428 case L2CAP_INFO_RSP:
5429 l2cap_information_rsp(conn, cmd, cmd_len, data);
5430 break;
5431
5432 case L2CAP_CREATE_CHAN_REQ:
5433 err = l2cap_create_channel_req(conn, cmd, cmd_len, data);
5434 break;
5435
5436 case L2CAP_MOVE_CHAN_REQ:
5437 err = l2cap_move_channel_req(conn, cmd, cmd_len, data);
5438 break;
5439
5440 case L2CAP_MOVE_CHAN_RSP:
5441 l2cap_move_channel_rsp(conn, cmd, cmd_len, data);
5442 break;
5443
5444 case L2CAP_MOVE_CHAN_CFM:
5445 err = l2cap_move_channel_confirm(conn, cmd, cmd_len, data);
5446 break;
5447
5448 case L2CAP_MOVE_CHAN_CFM_RSP:
5449 l2cap_move_channel_confirm_rsp(conn, cmd, cmd_len, data);
5450 break;
5451
5452 default:
5453 BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code);
5454 err = -EINVAL;
5455 break;
5456 }
5457
5458 return err;
5459 }
5460
5461 static int l2cap_le_connect_req(struct l2cap_conn *conn,
5462 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5463 u8 *data)
5464 {
5465 struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data;
5466 struct l2cap_le_conn_rsp rsp;
5467 struct l2cap_chan *chan, *pchan;
5468 u16 dcid, scid, credits, mtu, mps;
5469 __le16 psm;
5470 u8 result;
5471
5472 if (cmd_len != sizeof(*req))
5473 return -EPROTO;
5474
5475 scid = __le16_to_cpu(req->scid);
5476 mtu = __le16_to_cpu(req->mtu);
5477 mps = __le16_to_cpu(req->mps);
5478 psm = req->psm;
5479 dcid = 0;
5480 credits = 0;
5481
5482 if (mtu < 23 || mps < 23)
5483 return -EPROTO;
5484
5485 BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
5486 scid, mtu, mps);
5487
5488 /* Check if we have socket listening on psm */
5489 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
5490 &conn->hcon->dst, LE_LINK);
5491 if (!pchan) {
5492 result = L2CAP_CR_LE_BAD_PSM;
5493 chan = NULL;
5494 goto response;
5495 }
5496
5497 mutex_lock(&conn->chan_lock);
5498 l2cap_chan_lock(pchan);
5499
5500 if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
5501 SMP_ALLOW_STK)) {
5502 result = L2CAP_CR_LE_AUTHENTICATION;
5503 chan = NULL;
5504 goto response_unlock;
5505 }
5506
5507 /* Check for valid dynamic CID range */
5508 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
5509 result = L2CAP_CR_LE_INVALID_SCID;
5510 chan = NULL;
5511 goto response_unlock;
5512 }
5513
5514 /* Check if we already have channel with that dcid */
5515 if (__l2cap_get_chan_by_dcid(conn, scid)) {
5516 result = L2CAP_CR_LE_SCID_IN_USE;
5517 chan = NULL;
5518 goto response_unlock;
5519 }
5520
5521 chan = pchan->ops->new_connection(pchan);
5522 if (!chan) {
5523 result = L2CAP_CR_LE_NO_MEM;
5524 goto response_unlock;
5525 }
5526
5527 bacpy(&chan->src, &conn->hcon->src);
5528 bacpy(&chan->dst, &conn->hcon->dst);
5529 chan->src_type = bdaddr_src_type(conn->hcon);
5530 chan->dst_type = bdaddr_dst_type(conn->hcon);
5531 chan->psm = psm;
5532 chan->dcid = scid;
5533 chan->omtu = mtu;
5534 chan->remote_mps = mps;
5535
5536 __l2cap_chan_add(conn, chan);
5537
5538 l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits));
5539
5540 dcid = chan->scid;
5541 credits = chan->rx_credits;
5542
5543 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
5544
5545 chan->ident = cmd->ident;
5546
5547 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
5548 l2cap_state_change(chan, BT_CONNECT2);
5549 /* The following result value is actually not defined
5550 * for LE CoC but we use it to let the function know
5551 * that it should bail out after doing its cleanup
5552 * instead of sending a response.
5553 */
5554 result = L2CAP_CR_PEND;
5555 chan->ops->defer(chan);
5556 } else {
5557 l2cap_chan_ready(chan);
5558 result = L2CAP_CR_LE_SUCCESS;
5559 }
5560
5561 response_unlock:
5562 l2cap_chan_unlock(pchan);
5563 mutex_unlock(&conn->chan_lock);
5564 l2cap_chan_put(pchan);
5565
5566 if (result == L2CAP_CR_PEND)
5567 return 0;
5568
5569 response:
5570 if (chan) {
5571 rsp.mtu = cpu_to_le16(chan->imtu);
5572 rsp.mps = cpu_to_le16(chan->mps);
5573 } else {
5574 rsp.mtu = 0;
5575 rsp.mps = 0;
5576 }
5577
5578 rsp.dcid = cpu_to_le16(dcid);
5579 rsp.credits = cpu_to_le16(credits);
5580 rsp.result = cpu_to_le16(result);
5581
5582 l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp);
5583
5584 return 0;
5585 }
5586
5587 static inline int l2cap_le_credits(struct l2cap_conn *conn,
5588 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5589 u8 *data)
5590 {
5591 struct l2cap_le_credits *pkt;
5592 struct l2cap_chan *chan;
5593 u16 cid, credits, max_credits;
5594
5595 if (cmd_len != sizeof(*pkt))
5596 return -EPROTO;
5597
5598 pkt = (struct l2cap_le_credits *) data;
5599 cid = __le16_to_cpu(pkt->cid);
5600 credits = __le16_to_cpu(pkt->credits);
5601
5602 BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits);
5603
5604 chan = l2cap_get_chan_by_dcid(conn, cid);
5605 if (!chan)
5606 return -EBADSLT;
5607
5608 max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits;
5609 if (credits > max_credits) {
5610 BT_ERR("LE credits overflow");
5611 l2cap_send_disconn_req(chan, ECONNRESET);
5612 l2cap_chan_unlock(chan);
5613
5614 /* Return 0 so that we don't trigger an unnecessary
5615 * command reject packet.
5616 */
5617 return 0;
5618 }
5619
5620 chan->tx_credits += credits;
5621
5622 /* Resume sending */
5623 l2cap_le_flowctl_send(chan);
5624
5625 if (chan->tx_credits)
5626 chan->ops->resume(chan);
5627
5628 l2cap_chan_unlock(chan);
5629
5630 return 0;
5631 }
5632
5633 static inline int l2cap_le_command_rej(struct l2cap_conn *conn,
5634 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5635 u8 *data)
5636 {
5637 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
5638 struct l2cap_chan *chan;
5639
5640 if (cmd_len < sizeof(*rej))
5641 return -EPROTO;
5642
5643 mutex_lock(&conn->chan_lock);
5644
5645 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
5646 if (!chan)
5647 goto done;
5648
5649 l2cap_chan_lock(chan);
5650 l2cap_chan_del(chan, ECONNREFUSED);
5651 l2cap_chan_unlock(chan);
5652
5653 done:
5654 mutex_unlock(&conn->chan_lock);
5655 return 0;
5656 }
5657
5658 static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
5659 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5660 u8 *data)
5661 {
5662 int err = 0;
5663
5664 switch (cmd->code) {
5665 case L2CAP_COMMAND_REJ:
5666 l2cap_le_command_rej(conn, cmd, cmd_len, data);
5667 break;
5668
5669 case L2CAP_CONN_PARAM_UPDATE_REQ:
5670 err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data);
5671 break;
5672
5673 case L2CAP_CONN_PARAM_UPDATE_RSP:
5674 break;
5675
5676 case L2CAP_LE_CONN_RSP:
5677 l2cap_le_connect_rsp(conn, cmd, cmd_len, data);
5678 break;
5679
5680 case L2CAP_LE_CONN_REQ:
5681 err = l2cap_le_connect_req(conn, cmd, cmd_len, data);
5682 break;
5683
5684 case L2CAP_LE_CREDITS:
5685 err = l2cap_le_credits(conn, cmd, cmd_len, data);
5686 break;
5687
5688 case L2CAP_DISCONN_REQ:
5689 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
5690 break;
5691
5692 case L2CAP_DISCONN_RSP:
5693 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
5694 break;
5695
5696 default:
5697 BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code);
5698 err = -EINVAL;
5699 break;
5700 }
5701
5702 return err;
5703 }
5704
5705 static inline void l2cap_le_sig_channel(struct l2cap_conn *conn,
5706 struct sk_buff *skb)
5707 {
5708 struct hci_conn *hcon = conn->hcon;
5709 struct l2cap_cmd_hdr *cmd;
5710 u16 len;
5711 int err;
5712
5713 if (hcon->type != LE_LINK)
5714 goto drop;
5715
5716 if (skb->len < L2CAP_CMD_HDR_SIZE)
5717 goto drop;
5718
5719 cmd = (void *) skb->data;
5720 skb_pull(skb, L2CAP_CMD_HDR_SIZE);
5721
5722 len = le16_to_cpu(cmd->len);
5723
5724 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident);
5725
5726 if (len != skb->len || !cmd->ident) {
5727 BT_DBG("corrupted command");
5728 goto drop;
5729 }
5730
5731 err = l2cap_le_sig_cmd(conn, cmd, len, skb->data);
5732 if (err) {
5733 struct l2cap_cmd_rej_unk rej;
5734
5735 BT_ERR("Wrong link type (%d)", err);
5736
5737 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
5738 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ,
5739 sizeof(rej), &rej);
5740 }
5741
5742 drop:
5743 kfree_skb(skb);
5744 }
5745
5746 static inline void l2cap_sig_channel(struct l2cap_conn *conn,
5747 struct sk_buff *skb)
5748 {
5749 struct hci_conn *hcon = conn->hcon;
5750 u8 *data = skb->data;
5751 int len = skb->len;
5752 struct l2cap_cmd_hdr cmd;
5753 int err;
5754
5755 l2cap_raw_recv(conn, skb);
5756
5757 if (hcon->type != ACL_LINK)
5758 goto drop;
5759
5760 while (len >= L2CAP_CMD_HDR_SIZE) {
5761 u16 cmd_len;
5762 memcpy(&cmd, data, L2CAP_CMD_HDR_SIZE);
5763 data += L2CAP_CMD_HDR_SIZE;
5764 len -= L2CAP_CMD_HDR_SIZE;
5765
5766 cmd_len = le16_to_cpu(cmd.len);
5767
5768 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd.code, cmd_len,
5769 cmd.ident);
5770
5771 if (cmd_len > len || !cmd.ident) {
5772 BT_DBG("corrupted command");
5773 break;
5774 }
5775
5776 err = l2cap_bredr_sig_cmd(conn, &cmd, cmd_len, data);
5777 if (err) {
5778 struct l2cap_cmd_rej_unk rej;
5779
5780 BT_ERR("Wrong link type (%d)", err);
5781
5782 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
5783 l2cap_send_cmd(conn, cmd.ident, L2CAP_COMMAND_REJ,
5784 sizeof(rej), &rej);
5785 }
5786
5787 data += cmd_len;
5788 len -= cmd_len;
5789 }
5790
5791 drop:
5792 kfree_skb(skb);
5793 }
5794
5795 static int l2cap_check_fcs(struct l2cap_chan *chan, struct sk_buff *skb)
5796 {
5797 u16 our_fcs, rcv_fcs;
5798 int hdr_size;
5799
5800 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
5801 hdr_size = L2CAP_EXT_HDR_SIZE;
5802 else
5803 hdr_size = L2CAP_ENH_HDR_SIZE;
5804
5805 if (chan->fcs == L2CAP_FCS_CRC16) {
5806 skb_trim(skb, skb->len - L2CAP_FCS_SIZE);
5807 rcv_fcs = get_unaligned_le16(skb->data + skb->len);
5808 our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size);
5809
5810 if (our_fcs != rcv_fcs)
5811 return -EBADMSG;
5812 }
5813 return 0;
5814 }
5815
5816 static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan)
5817 {
5818 struct l2cap_ctrl control;
5819
5820 BT_DBG("chan %p", chan);
5821
5822 memset(&control, 0, sizeof(control));
5823 control.sframe = 1;
5824 control.final = 1;
5825 control.reqseq = chan->buffer_seq;
5826 set_bit(CONN_SEND_FBIT, &chan->conn_state);
5827
5828 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5829 control.super = L2CAP_SUPER_RNR;
5830 l2cap_send_sframe(chan, &control);
5831 }
5832
5833 if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) &&
5834 chan->unacked_frames > 0)
5835 __set_retrans_timer(chan);
5836
5837 /* Send pending iframes */
5838 l2cap_ertm_send(chan);
5839
5840 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
5841 test_bit(CONN_SEND_FBIT, &chan->conn_state)) {
5842 /* F-bit wasn't sent in an s-frame or i-frame yet, so
5843 * send it now.
5844 */
5845 control.super = L2CAP_SUPER_RR;
5846 l2cap_send_sframe(chan, &control);
5847 }
5848 }
5849
5850 static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag,
5851 struct sk_buff **last_frag)
5852 {
5853 /* skb->len reflects data in skb as well as all fragments
5854 * skb->data_len reflects only data in fragments
5855 */
5856 if (!skb_has_frag_list(skb))
5857 skb_shinfo(skb)->frag_list = new_frag;
5858
5859 new_frag->next = NULL;
5860
5861 (*last_frag)->next = new_frag;
5862 *last_frag = new_frag;
5863
5864 skb->len += new_frag->len;
5865 skb->data_len += new_frag->len;
5866 skb->truesize += new_frag->truesize;
5867 }
5868
5869 static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb,
5870 struct l2cap_ctrl *control)
5871 {
5872 int err = -EINVAL;
5873
5874 switch (control->sar) {
5875 case L2CAP_SAR_UNSEGMENTED:
5876 if (chan->sdu)
5877 break;
5878
5879 err = chan->ops->recv(chan, skb);
5880 break;
5881
5882 case L2CAP_SAR_START:
5883 if (chan->sdu)
5884 break;
5885
5886 if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE))
5887 break;
5888
5889 chan->sdu_len = get_unaligned_le16(skb->data);
5890 skb_pull(skb, L2CAP_SDULEN_SIZE);
5891
5892 if (chan->sdu_len > chan->imtu) {
5893 err = -EMSGSIZE;
5894 break;
5895 }
5896
5897 if (skb->len >= chan->sdu_len)
5898 break;
5899
5900 chan->sdu = skb;
5901 chan->sdu_last_frag = skb;
5902
5903 skb = NULL;
5904 err = 0;
5905 break;
5906
5907 case L2CAP_SAR_CONTINUE:
5908 if (!chan->sdu)
5909 break;
5910
5911 append_skb_frag(chan->sdu, skb,
5912 &chan->sdu_last_frag);
5913 skb = NULL;
5914
5915 if (chan->sdu->len >= chan->sdu_len)
5916 break;
5917
5918 err = 0;
5919 break;
5920
5921 case L2CAP_SAR_END:
5922 if (!chan->sdu)
5923 break;
5924
5925 append_skb_frag(chan->sdu, skb,
5926 &chan->sdu_last_frag);
5927 skb = NULL;
5928
5929 if (chan->sdu->len != chan->sdu_len)
5930 break;
5931
5932 err = chan->ops->recv(chan, chan->sdu);
5933
5934 if (!err) {
5935 /* Reassembly complete */
5936 chan->sdu = NULL;
5937 chan->sdu_last_frag = NULL;
5938 chan->sdu_len = 0;
5939 }
5940 break;
5941 }
5942
5943 if (err) {
5944 kfree_skb(skb);
5945 kfree_skb(chan->sdu);
5946 chan->sdu = NULL;
5947 chan->sdu_last_frag = NULL;
5948 chan->sdu_len = 0;
5949 }
5950
5951 return err;
5952 }
5953
5954 static int l2cap_resegment(struct l2cap_chan *chan)
5955 {
5956 /* Placeholder */
5957 return 0;
5958 }
5959
5960 void l2cap_chan_busy(struct l2cap_chan *chan, int busy)
5961 {
5962 u8 event;
5963
5964 if (chan->mode != L2CAP_MODE_ERTM)
5965 return;
5966
5967 event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR;
5968 l2cap_tx(chan, NULL, NULL, event);
5969 }
5970
5971 static int l2cap_rx_queued_iframes(struct l2cap_chan *chan)
5972 {
5973 int err = 0;
5974 /* Pass sequential frames to l2cap_reassemble_sdu()
5975 * until a gap is encountered.
5976 */
5977
5978 BT_DBG("chan %p", chan);
5979
5980 while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5981 struct sk_buff *skb;
5982 BT_DBG("Searching for skb with txseq %d (queue len %d)",
5983 chan->buffer_seq, skb_queue_len(&chan->srej_q));
5984
5985 skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq);
5986
5987 if (!skb)
5988 break;
5989
5990 skb_unlink(skb, &chan->srej_q);
5991 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
5992 err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap);
5993 if (err)
5994 break;
5995 }
5996
5997 if (skb_queue_empty(&chan->srej_q)) {
5998 chan->rx_state = L2CAP_RX_STATE_RECV;
5999 l2cap_send_ack(chan);
6000 }
6001
6002 return err;
6003 }
6004
6005 static void l2cap_handle_srej(struct l2cap_chan *chan,
6006 struct l2cap_ctrl *control)
6007 {
6008 struct sk_buff *skb;
6009
6010 BT_DBG("chan %p, control %p", chan, control);
6011
6012 if (control->reqseq == chan->next_tx_seq) {
6013 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
6014 l2cap_send_disconn_req(chan, ECONNRESET);
6015 return;
6016 }
6017
6018 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
6019
6020 if (skb == NULL) {
6021 BT_DBG("Seq %d not available for retransmission",
6022 control->reqseq);
6023 return;
6024 }
6025
6026 if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) {
6027 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
6028 l2cap_send_disconn_req(chan, ECONNRESET);
6029 return;
6030 }
6031
6032 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6033
6034 if (control->poll) {
6035 l2cap_pass_to_tx(chan, control);
6036
6037 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6038 l2cap_retransmit(chan, control);
6039 l2cap_ertm_send(chan);
6040
6041 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
6042 set_bit(CONN_SREJ_ACT, &chan->conn_state);
6043 chan->srej_save_reqseq = control->reqseq;
6044 }
6045 } else {
6046 l2cap_pass_to_tx_fbit(chan, control);
6047
6048 if (control->final) {
6049 if (chan->srej_save_reqseq != control->reqseq ||
6050 !test_and_clear_bit(CONN_SREJ_ACT,
6051 &chan->conn_state))
6052 l2cap_retransmit(chan, control);
6053 } else {
6054 l2cap_retransmit(chan, control);
6055 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
6056 set_bit(CONN_SREJ_ACT, &chan->conn_state);
6057 chan->srej_save_reqseq = control->reqseq;
6058 }
6059 }
6060 }
6061 }
6062
6063 static void l2cap_handle_rej(struct l2cap_chan *chan,
6064 struct l2cap_ctrl *control)
6065 {
6066 struct sk_buff *skb;
6067
6068 BT_DBG("chan %p, control %p", chan, control);
6069
6070 if (control->reqseq == chan->next_tx_seq) {
6071 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
6072 l2cap_send_disconn_req(chan, ECONNRESET);
6073 return;
6074 }
6075
6076 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
6077
6078 if (chan->max_tx && skb &&
6079 bt_cb(skb)->l2cap.retries >= chan->max_tx) {
6080 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
6081 l2cap_send_disconn_req(chan, ECONNRESET);
6082 return;
6083 }
6084
6085 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6086
6087 l2cap_pass_to_tx(chan, control);
6088
6089 if (control->final) {
6090 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state))
6091 l2cap_retransmit_all(chan, control);
6092 } else {
6093 l2cap_retransmit_all(chan, control);
6094 l2cap_ertm_send(chan);
6095 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F)
6096 set_bit(CONN_REJ_ACT, &chan->conn_state);
6097 }
6098 }
6099
6100 static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq)
6101 {
6102 BT_DBG("chan %p, txseq %d", chan, txseq);
6103
6104 BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq,
6105 chan->expected_tx_seq);
6106
6107 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
6108 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
6109 chan->tx_win) {
6110 /* See notes below regarding "double poll" and
6111 * invalid packets.
6112 */
6113 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
6114 BT_DBG("Invalid/Ignore - after SREJ");
6115 return L2CAP_TXSEQ_INVALID_IGNORE;
6116 } else {
6117 BT_DBG("Invalid - in window after SREJ sent");
6118 return L2CAP_TXSEQ_INVALID;
6119 }
6120 }
6121
6122 if (chan->srej_list.head == txseq) {
6123 BT_DBG("Expected SREJ");
6124 return L2CAP_TXSEQ_EXPECTED_SREJ;
6125 }
6126
6127 if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) {
6128 BT_DBG("Duplicate SREJ - txseq already stored");
6129 return L2CAP_TXSEQ_DUPLICATE_SREJ;
6130 }
6131
6132 if (l2cap_seq_list_contains(&chan->srej_list, txseq)) {
6133 BT_DBG("Unexpected SREJ - not requested");
6134 return L2CAP_TXSEQ_UNEXPECTED_SREJ;
6135 }
6136 }
6137
6138 if (chan->expected_tx_seq == txseq) {
6139 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
6140 chan->tx_win) {
6141 BT_DBG("Invalid - txseq outside tx window");
6142 return L2CAP_TXSEQ_INVALID;
6143 } else {
6144 BT_DBG("Expected");
6145 return L2CAP_TXSEQ_EXPECTED;
6146 }
6147 }
6148
6149 if (__seq_offset(chan, txseq, chan->last_acked_seq) <
6150 __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) {
6151 BT_DBG("Duplicate - expected_tx_seq later than txseq");
6152 return L2CAP_TXSEQ_DUPLICATE;
6153 }
6154
6155 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) {
6156 /* A source of invalid packets is a "double poll" condition,
6157 * where delays cause us to send multiple poll packets. If
6158 * the remote stack receives and processes both polls,
6159 * sequence numbers can wrap around in such a way that a
6160 * resent frame has a sequence number that looks like new data
6161 * with a sequence gap. This would trigger an erroneous SREJ
6162 * request.
6163 *
6164 * Fortunately, this is impossible with a tx window that's
6165 * less than half of the maximum sequence number, which allows
6166 * invalid frames to be safely ignored.
6167 *
6168 * With tx window sizes greater than half of the tx window
6169 * maximum, the frame is invalid and cannot be ignored. This
6170 * causes a disconnect.
6171 */
6172
6173 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
6174 BT_DBG("Invalid/Ignore - txseq outside tx window");
6175 return L2CAP_TXSEQ_INVALID_IGNORE;
6176 } else {
6177 BT_DBG("Invalid - txseq outside tx window");
6178 return L2CAP_TXSEQ_INVALID;
6179 }
6180 } else {
6181 BT_DBG("Unexpected - txseq indicates missing frames");
6182 return L2CAP_TXSEQ_UNEXPECTED;
6183 }
6184 }
6185
6186 static int l2cap_rx_state_recv(struct l2cap_chan *chan,
6187 struct l2cap_ctrl *control,
6188 struct sk_buff *skb, u8 event)
6189 {
6190 int err = 0;
6191 bool skb_in_use = false;
6192
6193 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6194 event);
6195
6196 switch (event) {
6197 case L2CAP_EV_RECV_IFRAME:
6198 switch (l2cap_classify_txseq(chan, control->txseq)) {
6199 case L2CAP_TXSEQ_EXPECTED:
6200 l2cap_pass_to_tx(chan, control);
6201
6202 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6203 BT_DBG("Busy, discarding expected seq %d",
6204 control->txseq);
6205 break;
6206 }
6207
6208 chan->expected_tx_seq = __next_seq(chan,
6209 control->txseq);
6210
6211 chan->buffer_seq = chan->expected_tx_seq;
6212 skb_in_use = true;
6213
6214 err = l2cap_reassemble_sdu(chan, skb, control);
6215 if (err)
6216 break;
6217
6218 if (control->final) {
6219 if (!test_and_clear_bit(CONN_REJ_ACT,
6220 &chan->conn_state)) {
6221 control->final = 0;
6222 l2cap_retransmit_all(chan, control);
6223 l2cap_ertm_send(chan);
6224 }
6225 }
6226
6227 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
6228 l2cap_send_ack(chan);
6229 break;
6230 case L2CAP_TXSEQ_UNEXPECTED:
6231 l2cap_pass_to_tx(chan, control);
6232
6233 /* Can't issue SREJ frames in the local busy state.
6234 * Drop this frame, it will be seen as missing
6235 * when local busy is exited.
6236 */
6237 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6238 BT_DBG("Busy, discarding unexpected seq %d",
6239 control->txseq);
6240 break;
6241 }
6242
6243 /* There was a gap in the sequence, so an SREJ
6244 * must be sent for each missing frame. The
6245 * current frame is stored for later use.
6246 */
6247 skb_queue_tail(&chan->srej_q, skb);
6248 skb_in_use = true;
6249 BT_DBG("Queued %p (queue len %d)", skb,
6250 skb_queue_len(&chan->srej_q));
6251
6252 clear_bit(CONN_SREJ_ACT, &chan->conn_state);
6253 l2cap_seq_list_clear(&chan->srej_list);
6254 l2cap_send_srej(chan, control->txseq);
6255
6256 chan->rx_state = L2CAP_RX_STATE_SREJ_SENT;
6257 break;
6258 case L2CAP_TXSEQ_DUPLICATE:
6259 l2cap_pass_to_tx(chan, control);
6260 break;
6261 case L2CAP_TXSEQ_INVALID_IGNORE:
6262 break;
6263 case L2CAP_TXSEQ_INVALID:
6264 default:
6265 l2cap_send_disconn_req(chan, ECONNRESET);
6266 break;
6267 }
6268 break;
6269 case L2CAP_EV_RECV_RR:
6270 l2cap_pass_to_tx(chan, control);
6271 if (control->final) {
6272 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6273
6274 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state) &&
6275 !__chan_is_moving(chan)) {
6276 control->final = 0;
6277 l2cap_retransmit_all(chan, control);
6278 }
6279
6280 l2cap_ertm_send(chan);
6281 } else if (control->poll) {
6282 l2cap_send_i_or_rr_or_rnr(chan);
6283 } else {
6284 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6285 &chan->conn_state) &&
6286 chan->unacked_frames)
6287 __set_retrans_timer(chan);
6288
6289 l2cap_ertm_send(chan);
6290 }
6291 break;
6292 case L2CAP_EV_RECV_RNR:
6293 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6294 l2cap_pass_to_tx(chan, control);
6295 if (control && control->poll) {
6296 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6297 l2cap_send_rr_or_rnr(chan, 0);
6298 }
6299 __clear_retrans_timer(chan);
6300 l2cap_seq_list_clear(&chan->retrans_list);
6301 break;
6302 case L2CAP_EV_RECV_REJ:
6303 l2cap_handle_rej(chan, control);
6304 break;
6305 case L2CAP_EV_RECV_SREJ:
6306 l2cap_handle_srej(chan, control);
6307 break;
6308 default:
6309 break;
6310 }
6311
6312 if (skb && !skb_in_use) {
6313 BT_DBG("Freeing %p", skb);
6314 kfree_skb(skb);
6315 }
6316
6317 return err;
6318 }
6319
6320 static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan,
6321 struct l2cap_ctrl *control,
6322 struct sk_buff *skb, u8 event)
6323 {
6324 int err = 0;
6325 u16 txseq = control->txseq;
6326 bool skb_in_use = false;
6327
6328 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6329 event);
6330
6331 switch (event) {
6332 case L2CAP_EV_RECV_IFRAME:
6333 switch (l2cap_classify_txseq(chan, txseq)) {
6334 case L2CAP_TXSEQ_EXPECTED:
6335 /* Keep frame for reassembly later */
6336 l2cap_pass_to_tx(chan, control);
6337 skb_queue_tail(&chan->srej_q, skb);
6338 skb_in_use = true;
6339 BT_DBG("Queued %p (queue len %d)", skb,
6340 skb_queue_len(&chan->srej_q));
6341
6342 chan->expected_tx_seq = __next_seq(chan, txseq);
6343 break;
6344 case L2CAP_TXSEQ_EXPECTED_SREJ:
6345 l2cap_seq_list_pop(&chan->srej_list);
6346
6347 l2cap_pass_to_tx(chan, control);
6348 skb_queue_tail(&chan->srej_q, skb);
6349 skb_in_use = true;
6350 BT_DBG("Queued %p (queue len %d)", skb,
6351 skb_queue_len(&chan->srej_q));
6352
6353 err = l2cap_rx_queued_iframes(chan);
6354 if (err)
6355 break;
6356
6357 break;
6358 case L2CAP_TXSEQ_UNEXPECTED:
6359 /* Got a frame that can't be reassembled yet.
6360 * Save it for later, and send SREJs to cover
6361 * the missing frames.
6362 */
6363 skb_queue_tail(&chan->srej_q, skb);
6364 skb_in_use = true;
6365 BT_DBG("Queued %p (queue len %d)", skb,
6366 skb_queue_len(&chan->srej_q));
6367
6368 l2cap_pass_to_tx(chan, control);
6369 l2cap_send_srej(chan, control->txseq);
6370 break;
6371 case L2CAP_TXSEQ_UNEXPECTED_SREJ:
6372 /* This frame was requested with an SREJ, but
6373 * some expected retransmitted frames are
6374 * missing. Request retransmission of missing
6375 * SREJ'd frames.
6376 */
6377 skb_queue_tail(&chan->srej_q, skb);
6378 skb_in_use = true;
6379 BT_DBG("Queued %p (queue len %d)", skb,
6380 skb_queue_len(&chan->srej_q));
6381
6382 l2cap_pass_to_tx(chan, control);
6383 l2cap_send_srej_list(chan, control->txseq);
6384 break;
6385 case L2CAP_TXSEQ_DUPLICATE_SREJ:
6386 /* We've already queued this frame. Drop this copy. */
6387 l2cap_pass_to_tx(chan, control);
6388 break;
6389 case L2CAP_TXSEQ_DUPLICATE:
6390 /* Expecting a later sequence number, so this frame
6391 * was already received. Ignore it completely.
6392 */
6393 break;
6394 case L2CAP_TXSEQ_INVALID_IGNORE:
6395 break;
6396 case L2CAP_TXSEQ_INVALID:
6397 default:
6398 l2cap_send_disconn_req(chan, ECONNRESET);
6399 break;
6400 }
6401 break;
6402 case L2CAP_EV_RECV_RR:
6403 l2cap_pass_to_tx(chan, control);
6404 if (control->final) {
6405 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6406
6407 if (!test_and_clear_bit(CONN_REJ_ACT,
6408 &chan->conn_state)) {
6409 control->final = 0;
6410 l2cap_retransmit_all(chan, control);
6411 }
6412
6413 l2cap_ertm_send(chan);
6414 } else if (control->poll) {
6415 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6416 &chan->conn_state) &&
6417 chan->unacked_frames) {
6418 __set_retrans_timer(chan);
6419 }
6420
6421 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6422 l2cap_send_srej_tail(chan);
6423 } else {
6424 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6425 &chan->conn_state) &&
6426 chan->unacked_frames)
6427 __set_retrans_timer(chan);
6428
6429 l2cap_send_ack(chan);
6430 }
6431 break;
6432 case L2CAP_EV_RECV_RNR:
6433 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6434 l2cap_pass_to_tx(chan, control);
6435 if (control->poll) {
6436 l2cap_send_srej_tail(chan);
6437 } else {
6438 struct l2cap_ctrl rr_control;
6439 memset(&rr_control, 0, sizeof(rr_control));
6440 rr_control.sframe = 1;
6441 rr_control.super = L2CAP_SUPER_RR;
6442 rr_control.reqseq = chan->buffer_seq;
6443 l2cap_send_sframe(chan, &rr_control);
6444 }
6445
6446 break;
6447 case L2CAP_EV_RECV_REJ:
6448 l2cap_handle_rej(chan, control);
6449 break;
6450 case L2CAP_EV_RECV_SREJ:
6451 l2cap_handle_srej(chan, control);
6452 break;
6453 }
6454
6455 if (skb && !skb_in_use) {
6456 BT_DBG("Freeing %p", skb);
6457 kfree_skb(skb);
6458 }
6459
6460 return err;
6461 }
6462
6463 static int l2cap_finish_move(struct l2cap_chan *chan)
6464 {
6465 BT_DBG("chan %p", chan);
6466
6467 chan->rx_state = L2CAP_RX_STATE_RECV;
6468
6469 if (chan->hs_hcon)
6470 chan->conn->mtu = chan->hs_hcon->hdev->block_mtu;
6471 else
6472 chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
6473
6474 return l2cap_resegment(chan);
6475 }
6476
6477 static int l2cap_rx_state_wait_p(struct l2cap_chan *chan,
6478 struct l2cap_ctrl *control,
6479 struct sk_buff *skb, u8 event)
6480 {
6481 int err;
6482
6483 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6484 event);
6485
6486 if (!control->poll)
6487 return -EPROTO;
6488
6489 l2cap_process_reqseq(chan, control->reqseq);
6490
6491 if (!skb_queue_empty(&chan->tx_q))
6492 chan->tx_send_head = skb_peek(&chan->tx_q);
6493 else
6494 chan->tx_send_head = NULL;
6495
6496 /* Rewind next_tx_seq to the point expected
6497 * by the receiver.
6498 */
6499 chan->next_tx_seq = control->reqseq;
6500 chan->unacked_frames = 0;
6501
6502 err = l2cap_finish_move(chan);
6503 if (err)
6504 return err;
6505
6506 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6507 l2cap_send_i_or_rr_or_rnr(chan);
6508
6509 if (event == L2CAP_EV_RECV_IFRAME)
6510 return -EPROTO;
6511
6512 return l2cap_rx_state_recv(chan, control, NULL, event);
6513 }
6514
6515 static int l2cap_rx_state_wait_f(struct l2cap_chan *chan,
6516 struct l2cap_ctrl *control,
6517 struct sk_buff *skb, u8 event)
6518 {
6519 int err;
6520
6521 if (!control->final)
6522 return -EPROTO;
6523
6524 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6525
6526 chan->rx_state = L2CAP_RX_STATE_RECV;
6527 l2cap_process_reqseq(chan, control->reqseq);
6528
6529 if (!skb_queue_empty(&chan->tx_q))
6530 chan->tx_send_head = skb_peek(&chan->tx_q);
6531 else
6532 chan->tx_send_head = NULL;
6533
6534 /* Rewind next_tx_seq to the point expected
6535 * by the receiver.
6536 */
6537 chan->next_tx_seq = control->reqseq;
6538 chan->unacked_frames = 0;
6539
6540 if (chan->hs_hcon)
6541 chan->conn->mtu = chan->hs_hcon->hdev->block_mtu;
6542 else
6543 chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
6544
6545 err = l2cap_resegment(chan);
6546
6547 if (!err)
6548 err = l2cap_rx_state_recv(chan, control, skb, event);
6549
6550 return err;
6551 }
6552
6553 static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq)
6554 {
6555 /* Make sure reqseq is for a packet that has been sent but not acked */
6556 u16 unacked;
6557
6558 unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq);
6559 return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked;
6560 }
6561
6562 static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
6563 struct sk_buff *skb, u8 event)
6564 {
6565 int err = 0;
6566
6567 BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan,
6568 control, skb, event, chan->rx_state);
6569
6570 if (__valid_reqseq(chan, control->reqseq)) {
6571 switch (chan->rx_state) {
6572 case L2CAP_RX_STATE_RECV:
6573 err = l2cap_rx_state_recv(chan, control, skb, event);
6574 break;
6575 case L2CAP_RX_STATE_SREJ_SENT:
6576 err = l2cap_rx_state_srej_sent(chan, control, skb,
6577 event);
6578 break;
6579 case L2CAP_RX_STATE_WAIT_P:
6580 err = l2cap_rx_state_wait_p(chan, control, skb, event);
6581 break;
6582 case L2CAP_RX_STATE_WAIT_F:
6583 err = l2cap_rx_state_wait_f(chan, control, skb, event);
6584 break;
6585 default:
6586 /* shut it down */
6587 break;
6588 }
6589 } else {
6590 BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d",
6591 control->reqseq, chan->next_tx_seq,
6592 chan->expected_ack_seq);
6593 l2cap_send_disconn_req(chan, ECONNRESET);
6594 }
6595
6596 return err;
6597 }
6598
6599 static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
6600 struct sk_buff *skb)
6601 {
6602 BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb,
6603 chan->rx_state);
6604
6605 if (l2cap_classify_txseq(chan, control->txseq) ==
6606 L2CAP_TXSEQ_EXPECTED) {
6607 l2cap_pass_to_tx(chan, control);
6608
6609 BT_DBG("buffer_seq %d->%d", chan->buffer_seq,
6610 __next_seq(chan, chan->buffer_seq));
6611
6612 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
6613
6614 l2cap_reassemble_sdu(chan, skb, control);
6615 } else {
6616 if (chan->sdu) {
6617 kfree_skb(chan->sdu);
6618 chan->sdu = NULL;
6619 }
6620 chan->sdu_last_frag = NULL;
6621 chan->sdu_len = 0;
6622
6623 if (skb) {
6624 BT_DBG("Freeing %p", skb);
6625 kfree_skb(skb);
6626 }
6627 }
6628
6629 chan->last_acked_seq = control->txseq;
6630 chan->expected_tx_seq = __next_seq(chan, control->txseq);
6631
6632 return 0;
6633 }
6634
6635 static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
6636 {
6637 struct l2cap_ctrl *control = &bt_cb(skb)->l2cap;
6638 u16 len;
6639 u8 event;
6640
6641 __unpack_control(chan, skb);
6642
6643 len = skb->len;
6644
6645 /*
6646 * We can just drop the corrupted I-frame here.
6647 * Receiver will miss it and start proper recovery
6648 * procedures and ask for retransmission.
6649 */
6650 if (l2cap_check_fcs(chan, skb))
6651 goto drop;
6652
6653 if (!control->sframe && control->sar == L2CAP_SAR_START)
6654 len -= L2CAP_SDULEN_SIZE;
6655
6656 if (chan->fcs == L2CAP_FCS_CRC16)
6657 len -= L2CAP_FCS_SIZE;
6658
6659 if (len > chan->mps) {
6660 l2cap_send_disconn_req(chan, ECONNRESET);
6661 goto drop;
6662 }
6663
6664 if ((chan->mode == L2CAP_MODE_ERTM ||
6665 chan->mode == L2CAP_MODE_STREAMING) && sk_filter(chan->data, skb))
6666 goto drop;
6667
6668 if (!control->sframe) {
6669 int err;
6670
6671 BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d",
6672 control->sar, control->reqseq, control->final,
6673 control->txseq);
6674
6675 /* Validate F-bit - F=0 always valid, F=1 only
6676 * valid in TX WAIT_F
6677 */
6678 if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F)
6679 goto drop;
6680
6681 if (chan->mode != L2CAP_MODE_STREAMING) {
6682 event = L2CAP_EV_RECV_IFRAME;
6683 err = l2cap_rx(chan, control, skb, event);
6684 } else {
6685 err = l2cap_stream_rx(chan, control, skb);
6686 }
6687
6688 if (err)
6689 l2cap_send_disconn_req(chan, ECONNRESET);
6690 } else {
6691 const u8 rx_func_to_event[4] = {
6692 L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ,
6693 L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ
6694 };
6695
6696 /* Only I-frames are expected in streaming mode */
6697 if (chan->mode == L2CAP_MODE_STREAMING)
6698 goto drop;
6699
6700 BT_DBG("sframe reqseq %d, final %d, poll %d, super %d",
6701 control->reqseq, control->final, control->poll,
6702 control->super);
6703
6704 if (len != 0) {
6705 BT_ERR("Trailing bytes: %d in sframe", len);
6706 l2cap_send_disconn_req(chan, ECONNRESET);
6707 goto drop;
6708 }
6709
6710 /* Validate F and P bits */
6711 if (control->final && (control->poll ||
6712 chan->tx_state != L2CAP_TX_STATE_WAIT_F))
6713 goto drop;
6714
6715 event = rx_func_to_event[control->super];
6716 if (l2cap_rx(chan, control, skb, event))
6717 l2cap_send_disconn_req(chan, ECONNRESET);
6718 }
6719
6720 return 0;
6721
6722 drop:
6723 kfree_skb(skb);
6724 return 0;
6725 }
6726
6727 static void l2cap_chan_le_send_credits(struct l2cap_chan *chan)
6728 {
6729 struct l2cap_conn *conn = chan->conn;
6730 struct l2cap_le_credits pkt;
6731 u16 return_credits;
6732
6733 return_credits = ((chan->imtu / chan->mps) + 1) - chan->rx_credits;
6734
6735 if (!return_credits)
6736 return;
6737
6738 BT_DBG("chan %p returning %u credits to sender", chan, return_credits);
6739
6740 chan->rx_credits += return_credits;
6741
6742 pkt.cid = cpu_to_le16(chan->scid);
6743 pkt.credits = cpu_to_le16(return_credits);
6744
6745 chan->ident = l2cap_get_ident(conn);
6746
6747 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt);
6748 }
6749
6750 static int l2cap_le_recv(struct l2cap_chan *chan, struct sk_buff *skb)
6751 {
6752 int err;
6753
6754 BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len);
6755
6756 /* Wait recv to confirm reception before updating the credits */
6757 err = chan->ops->recv(chan, skb);
6758
6759 /* Update credits whenever an SDU is received */
6760 l2cap_chan_le_send_credits(chan);
6761
6762 return err;
6763 }
6764
6765 static int l2cap_le_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
6766 {
6767 int err;
6768
6769 if (!chan->rx_credits) {
6770 BT_ERR("No credits to receive LE L2CAP data");
6771 l2cap_send_disconn_req(chan, ECONNRESET);
6772 return -ENOBUFS;
6773 }
6774
6775 if (chan->imtu < skb->len) {
6776 BT_ERR("Too big LE L2CAP PDU");
6777 return -ENOBUFS;
6778 }
6779
6780 chan->rx_credits--;
6781 BT_DBG("rx_credits %u -> %u", chan->rx_credits + 1, chan->rx_credits);
6782
6783 /* Update if remote had run out of credits, this should only happens
6784 * if the remote is not using the entire MPS.
6785 */
6786 if (!chan->rx_credits)
6787 l2cap_chan_le_send_credits(chan);
6788
6789 err = 0;
6790
6791 if (!chan->sdu) {
6792 u16 sdu_len;
6793
6794 sdu_len = get_unaligned_le16(skb->data);
6795 skb_pull(skb, L2CAP_SDULEN_SIZE);
6796
6797 BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u",
6798 sdu_len, skb->len, chan->imtu);
6799
6800 if (sdu_len > chan->imtu) {
6801 BT_ERR("Too big LE L2CAP SDU length received");
6802 err = -EMSGSIZE;
6803 goto failed;
6804 }
6805
6806 if (skb->len > sdu_len) {
6807 BT_ERR("Too much LE L2CAP data received");
6808 err = -EINVAL;
6809 goto failed;
6810 }
6811
6812 if (skb->len == sdu_len)
6813 return l2cap_le_recv(chan, skb);
6814
6815 chan->sdu = skb;
6816 chan->sdu_len = sdu_len;
6817 chan->sdu_last_frag = skb;
6818
6819 /* Detect if remote is not able to use the selected MPS */
6820 if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) {
6821 u16 mps_len = skb->len + L2CAP_SDULEN_SIZE;
6822
6823 /* Adjust the number of credits */
6824 BT_DBG("chan->mps %u -> %u", chan->mps, mps_len);
6825 chan->mps = mps_len;
6826 l2cap_chan_le_send_credits(chan);
6827 }
6828
6829 return 0;
6830 }
6831
6832 BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u",
6833 chan->sdu->len, skb->len, chan->sdu_len);
6834
6835 if (chan->sdu->len + skb->len > chan->sdu_len) {
6836 BT_ERR("Too much LE L2CAP data received");
6837 err = -EINVAL;
6838 goto failed;
6839 }
6840
6841 append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag);
6842 skb = NULL;
6843
6844 if (chan->sdu->len == chan->sdu_len) {
6845 err = l2cap_le_recv(chan, chan->sdu);
6846 if (!err) {
6847 chan->sdu = NULL;
6848 chan->sdu_last_frag = NULL;
6849 chan->sdu_len = 0;
6850 }
6851 }
6852
6853 failed:
6854 if (err) {
6855 kfree_skb(skb);
6856 kfree_skb(chan->sdu);
6857 chan->sdu = NULL;
6858 chan->sdu_last_frag = NULL;
6859 chan->sdu_len = 0;
6860 }
6861
6862 /* We can't return an error here since we took care of the skb
6863 * freeing internally. An error return would cause the caller to
6864 * do a double-free of the skb.
6865 */
6866 return 0;
6867 }
6868
6869 static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,
6870 struct sk_buff *skb)
6871 {
6872 struct l2cap_chan *chan;
6873
6874 chan = l2cap_get_chan_by_scid(conn, cid);
6875 if (!chan) {
6876 if (cid == L2CAP_CID_A2MP) {
6877 chan = a2mp_channel_create(conn, skb);
6878 if (!chan) {
6879 kfree_skb(skb);
6880 return;
6881 }
6882
6883 l2cap_chan_lock(chan);
6884 } else {
6885 BT_DBG("unknown cid 0x%4.4x", cid);
6886 /* Drop packet and return */
6887 kfree_skb(skb);
6888 return;
6889 }
6890 }
6891
6892 BT_DBG("chan %p, len %d", chan, skb->len);
6893
6894 /* If we receive data on a fixed channel before the info req/rsp
6895 * procdure is done simply assume that the channel is supported
6896 * and mark it as ready.
6897 */
6898 if (chan->chan_type == L2CAP_CHAN_FIXED)
6899 l2cap_chan_ready(chan);
6900
6901 if (chan->state != BT_CONNECTED)
6902 goto drop;
6903
6904 switch (chan->mode) {
6905 case L2CAP_MODE_LE_FLOWCTL:
6906 if (l2cap_le_data_rcv(chan, skb) < 0)
6907 goto drop;
6908
6909 goto done;
6910
6911 case L2CAP_MODE_BASIC:
6912 /* If socket recv buffers overflows we drop data here
6913 * which is *bad* because L2CAP has to be reliable.
6914 * But we don't have any other choice. L2CAP doesn't
6915 * provide flow control mechanism. */
6916
6917 if (chan->imtu < skb->len) {
6918 BT_ERR("Dropping L2CAP data: receive buffer overflow");
6919 goto drop;
6920 }
6921
6922 if (!chan->ops->recv(chan, skb))
6923 goto done;
6924 break;
6925
6926 case L2CAP_MODE_ERTM:
6927 case L2CAP_MODE_STREAMING:
6928 l2cap_data_rcv(chan, skb);
6929 goto done;
6930
6931 default:
6932 BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode);
6933 break;
6934 }
6935
6936 drop:
6937 kfree_skb(skb);
6938
6939 done:
6940 l2cap_chan_unlock(chan);
6941 }
6942
6943 static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm,
6944 struct sk_buff *skb)
6945 {
6946 struct hci_conn *hcon = conn->hcon;
6947 struct l2cap_chan *chan;
6948
6949 if (hcon->type != ACL_LINK)
6950 goto free_skb;
6951
6952 chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst,
6953 ACL_LINK);
6954 if (!chan)
6955 goto free_skb;
6956
6957 BT_DBG("chan %p, len %d", chan, skb->len);
6958
6959 if (chan->state != BT_BOUND && chan->state != BT_CONNECTED)
6960 goto drop;
6961
6962 if (chan->imtu < skb->len)
6963 goto drop;
6964
6965 /* Store remote BD_ADDR and PSM for msg_name */
6966 bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst);
6967 bt_cb(skb)->l2cap.psm = psm;
6968
6969 if (!chan->ops->recv(chan, skb)) {
6970 l2cap_chan_put(chan);
6971 return;
6972 }
6973
6974 drop:
6975 l2cap_chan_put(chan);
6976 free_skb:
6977 kfree_skb(skb);
6978 }
6979
6980 static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
6981 {
6982 struct l2cap_hdr *lh = (void *) skb->data;
6983 struct hci_conn *hcon = conn->hcon;
6984 u16 cid, len;
6985 __le16 psm;
6986
6987 if (hcon->state != BT_CONNECTED) {
6988 BT_DBG("queueing pending rx skb");
6989 skb_queue_tail(&conn->pending_rx, skb);
6990 return;
6991 }
6992
6993 skb_pull(skb, L2CAP_HDR_SIZE);
6994 cid = __le16_to_cpu(lh->cid);
6995 len = __le16_to_cpu(lh->len);
6996
6997 if (len != skb->len) {
6998 kfree_skb(skb);
6999 return;
7000 }
7001
7002 /* Since we can't actively block incoming LE connections we must
7003 * at least ensure that we ignore incoming data from them.
7004 */
7005 if (hcon->type == LE_LINK &&
7006 hci_bdaddr_list_lookup(&hcon->hdev->blacklist, &hcon->dst,
7007 bdaddr_dst_type(hcon))) {
7008 kfree_skb(skb);
7009 return;
7010 }
7011
7012 BT_DBG("len %d, cid 0x%4.4x", len, cid);
7013
7014 switch (cid) {
7015 case L2CAP_CID_SIGNALING:
7016 l2cap_sig_channel(conn, skb);
7017 break;
7018
7019 case L2CAP_CID_CONN_LESS:
7020 psm = get_unaligned((__le16 *) skb->data);
7021 skb_pull(skb, L2CAP_PSMLEN_SIZE);
7022 l2cap_conless_channel(conn, psm, skb);
7023 break;
7024
7025 case L2CAP_CID_LE_SIGNALING:
7026 l2cap_le_sig_channel(conn, skb);
7027 break;
7028
7029 default:
7030 l2cap_data_channel(conn, cid, skb);
7031 break;
7032 }
7033 }
7034
7035 static void process_pending_rx(struct work_struct *work)
7036 {
7037 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
7038 pending_rx_work);
7039 struct sk_buff *skb;
7040
7041 BT_DBG("");
7042
7043 while ((skb = skb_dequeue(&conn->pending_rx)))
7044 l2cap_recv_frame(conn, skb);
7045 }
7046
7047 static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon)
7048 {
7049 struct l2cap_conn *conn = hcon->l2cap_data;
7050 struct hci_chan *hchan;
7051
7052 if (conn)
7053 return conn;
7054
7055 hchan = hci_chan_create(hcon);
7056 if (!hchan)
7057 return NULL;
7058
7059 conn = kzalloc(sizeof(*conn), GFP_KERNEL);
7060 if (!conn) {
7061 hci_chan_del(hchan);
7062 return NULL;
7063 }
7064
7065 kref_init(&conn->ref);
7066 hcon->l2cap_data = conn;
7067 conn->hcon = hci_conn_get(hcon);
7068 conn->hchan = hchan;
7069
7070 BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan);
7071
7072 switch (hcon->type) {
7073 case LE_LINK:
7074 if (hcon->hdev->le_mtu) {
7075 conn->mtu = hcon->hdev->le_mtu;
7076 break;
7077 }
7078 /* fall through */
7079 default:
7080 conn->mtu = hcon->hdev->acl_mtu;
7081 break;
7082 }
7083
7084 conn->feat_mask = 0;
7085
7086 conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS;
7087
7088 if (hcon->type == ACL_LINK &&
7089 hci_dev_test_flag(hcon->hdev, HCI_HS_ENABLED))
7090 conn->local_fixed_chan |= L2CAP_FC_A2MP;
7091
7092 if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) &&
7093 (bredr_sc_enabled(hcon->hdev) ||
7094 hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP)))
7095 conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR;
7096
7097 mutex_init(&conn->ident_lock);
7098 mutex_init(&conn->chan_lock);
7099
7100 INIT_LIST_HEAD(&conn->chan_l);
7101 INIT_LIST_HEAD(&conn->users);
7102
7103 INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout);
7104
7105 skb_queue_head_init(&conn->pending_rx);
7106 INIT_WORK(&conn->pending_rx_work, process_pending_rx);
7107 INIT_WORK(&conn->id_addr_update_work, l2cap_conn_update_id_addr);
7108
7109 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
7110
7111 return conn;
7112 }
7113
7114 static bool is_valid_psm(u16 psm, u8 dst_type) {
7115 if (!psm)
7116 return false;
7117
7118 if (bdaddr_type_is_le(dst_type))
7119 return (psm <= 0x00ff);
7120
7121 /* PSM must be odd and lsb of upper byte must be 0 */
7122 return ((psm & 0x0101) == 0x0001);
7123 }
7124
7125 int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
7126 bdaddr_t *dst, u8 dst_type)
7127 {
7128 struct l2cap_conn *conn;
7129 struct hci_conn *hcon;
7130 struct hci_dev *hdev;
7131 int err;
7132
7133 BT_DBG("%pMR -> %pMR (type %u) psm 0x%2.2x", &chan->src, dst,
7134 dst_type, __le16_to_cpu(psm));
7135
7136 hdev = hci_get_route(dst, &chan->src, chan->src_type);
7137 if (!hdev)
7138 return -EHOSTUNREACH;
7139
7140 hci_dev_lock(hdev);
7141
7142 if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid &&
7143 chan->chan_type != L2CAP_CHAN_RAW) {
7144 err = -EINVAL;
7145 goto done;
7146 }
7147
7148 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) {
7149 err = -EINVAL;
7150 goto done;
7151 }
7152
7153 if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) {
7154 err = -EINVAL;
7155 goto done;
7156 }
7157
7158 switch (chan->mode) {
7159 case L2CAP_MODE_BASIC:
7160 break;
7161 case L2CAP_MODE_LE_FLOWCTL:
7162 break;
7163 case L2CAP_MODE_ERTM:
7164 case L2CAP_MODE_STREAMING:
7165 if (!disable_ertm)
7166 break;
7167 /* fall through */
7168 default:
7169 err = -EOPNOTSUPP;
7170 goto done;
7171 }
7172
7173 switch (chan->state) {
7174 case BT_CONNECT:
7175 case BT_CONNECT2:
7176 case BT_CONFIG:
7177 /* Already connecting */
7178 err = 0;
7179 goto done;
7180
7181 case BT_CONNECTED:
7182 /* Already connected */
7183 err = -EISCONN;
7184 goto done;
7185
7186 case BT_OPEN:
7187 case BT_BOUND:
7188 /* Can connect */
7189 break;
7190
7191 default:
7192 err = -EBADFD;
7193 goto done;
7194 }
7195
7196 /* Set destination address and psm */
7197 bacpy(&chan->dst, dst);
7198 chan->dst_type = dst_type;
7199
7200 chan->psm = psm;
7201 chan->dcid = cid;
7202
7203 if (bdaddr_type_is_le(dst_type)) {
7204 /* Convert from L2CAP channel address type to HCI address type
7205 */
7206 if (dst_type == BDADDR_LE_PUBLIC)
7207 dst_type = ADDR_LE_DEV_PUBLIC;
7208 else
7209 dst_type = ADDR_LE_DEV_RANDOM;
7210
7211 if (hci_dev_test_flag(hdev, HCI_ADVERTISING))
7212 hcon = hci_connect_le(hdev, dst, dst_type,
7213 chan->sec_level,
7214 HCI_LE_CONN_TIMEOUT,
7215 HCI_ROLE_SLAVE, NULL);
7216 else
7217 hcon = hci_connect_le_scan(hdev, dst, dst_type,
7218 chan->sec_level,
7219 HCI_LE_CONN_TIMEOUT);
7220
7221 } else {
7222 u8 auth_type = l2cap_get_auth_type(chan);
7223 hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type);
7224 }
7225
7226 if (IS_ERR(hcon)) {
7227 err = PTR_ERR(hcon);
7228 goto done;
7229 }
7230
7231 conn = l2cap_conn_add(hcon);
7232 if (!conn) {
7233 hci_conn_drop(hcon);
7234 err = -ENOMEM;
7235 goto done;
7236 }
7237
7238 mutex_lock(&conn->chan_lock);
7239 l2cap_chan_lock(chan);
7240
7241 if (cid && __l2cap_get_chan_by_dcid(conn, cid)) {
7242 hci_conn_drop(hcon);
7243 err = -EBUSY;
7244 goto chan_unlock;
7245 }
7246
7247 /* Update source addr of the socket */
7248 bacpy(&chan->src, &hcon->src);
7249 chan->src_type = bdaddr_src_type(hcon);
7250
7251 __l2cap_chan_add(conn, chan);
7252
7253 /* l2cap_chan_add takes its own ref so we can drop this one */
7254 hci_conn_drop(hcon);
7255
7256 l2cap_state_change(chan, BT_CONNECT);
7257 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
7258
7259 /* Release chan->sport so that it can be reused by other
7260 * sockets (as it's only used for listening sockets).
7261 */
7262 write_lock(&chan_list_lock);
7263 chan->sport = 0;
7264 write_unlock(&chan_list_lock);
7265
7266 if (hcon->state == BT_CONNECTED) {
7267 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
7268 __clear_chan_timer(chan);
7269 if (l2cap_chan_check_security(chan, true))
7270 l2cap_state_change(chan, BT_CONNECTED);
7271 } else
7272 l2cap_do_start(chan);
7273 }
7274
7275 err = 0;
7276
7277 chan_unlock:
7278 l2cap_chan_unlock(chan);
7279 mutex_unlock(&conn->chan_lock);
7280 done:
7281 hci_dev_unlock(hdev);
7282 hci_dev_put(hdev);
7283 return err;
7284 }
7285 EXPORT_SYMBOL_GPL(l2cap_chan_connect);
7286
7287 /* ---- L2CAP interface with lower layer (HCI) ---- */
7288
7289 int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr)
7290 {
7291 int exact = 0, lm1 = 0, lm2 = 0;
7292 struct l2cap_chan *c;
7293
7294 BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr);
7295
7296 /* Find listening sockets and check their link_mode */
7297 read_lock(&chan_list_lock);
7298 list_for_each_entry(c, &chan_list, global_l) {
7299 if (c->state != BT_LISTEN)
7300 continue;
7301
7302 if (!bacmp(&c->src, &hdev->bdaddr)) {
7303 lm1 |= HCI_LM_ACCEPT;
7304 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
7305 lm1 |= HCI_LM_MASTER;
7306 exact++;
7307 } else if (!bacmp(&c->src, BDADDR_ANY)) {
7308 lm2 |= HCI_LM_ACCEPT;
7309 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
7310 lm2 |= HCI_LM_MASTER;
7311 }
7312 }
7313 read_unlock(&chan_list_lock);
7314
7315 return exact ? lm1 : lm2;
7316 }
7317
7318 /* Find the next fixed channel in BT_LISTEN state, continue iteration
7319 * from an existing channel in the list or from the beginning of the
7320 * global list (by passing NULL as first parameter).
7321 */
7322 static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c,
7323 struct hci_conn *hcon)
7324 {
7325 u8 src_type = bdaddr_src_type(hcon);
7326
7327 read_lock(&chan_list_lock);
7328
7329 if (c)
7330 c = list_next_entry(c, global_l);
7331 else
7332 c = list_entry(chan_list.next, typeof(*c), global_l);
7333
7334 list_for_each_entry_from(c, &chan_list, global_l) {
7335 if (c->chan_type != L2CAP_CHAN_FIXED)
7336 continue;
7337 if (c->state != BT_LISTEN)
7338 continue;
7339 if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY))
7340 continue;
7341 if (src_type != c->src_type)
7342 continue;
7343
7344 l2cap_chan_hold(c);
7345 read_unlock(&chan_list_lock);
7346 return c;
7347 }
7348
7349 read_unlock(&chan_list_lock);
7350
7351 return NULL;
7352 }
7353
7354 static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status)
7355 {
7356 struct hci_dev *hdev = hcon->hdev;
7357 struct l2cap_conn *conn;
7358 struct l2cap_chan *pchan;
7359 u8 dst_type;
7360
7361 if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
7362 return;
7363
7364 BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status);
7365
7366 if (status) {
7367 l2cap_conn_del(hcon, bt_to_errno(status));
7368 return;
7369 }
7370
7371 conn = l2cap_conn_add(hcon);
7372 if (!conn)
7373 return;
7374
7375 dst_type = bdaddr_dst_type(hcon);
7376
7377 /* If device is blocked, do not create channels for it */
7378 if (hci_bdaddr_list_lookup(&hdev->blacklist, &hcon->dst, dst_type))
7379 return;
7380
7381 /* Find fixed channels and notify them of the new connection. We
7382 * use multiple individual lookups, continuing each time where
7383 * we left off, because the list lock would prevent calling the
7384 * potentially sleeping l2cap_chan_lock() function.
7385 */
7386 pchan = l2cap_global_fixed_chan(NULL, hcon);
7387 while (pchan) {
7388 struct l2cap_chan *chan, *next;
7389
7390 /* Client fixed channels should override server ones */
7391 if (__l2cap_get_chan_by_dcid(conn, pchan->scid))
7392 goto next;
7393
7394 l2cap_chan_lock(pchan);
7395 chan = pchan->ops->new_connection(pchan);
7396 if (chan) {
7397 bacpy(&chan->src, &hcon->src);
7398 bacpy(&chan->dst, &hcon->dst);
7399 chan->src_type = bdaddr_src_type(hcon);
7400 chan->dst_type = dst_type;
7401
7402 __l2cap_chan_add(conn, chan);
7403 }
7404
7405 l2cap_chan_unlock(pchan);
7406 next:
7407 next = l2cap_global_fixed_chan(pchan, hcon);
7408 l2cap_chan_put(pchan);
7409 pchan = next;
7410 }
7411
7412 l2cap_conn_ready(conn);
7413 }
7414
7415 int l2cap_disconn_ind(struct hci_conn *hcon)
7416 {
7417 struct l2cap_conn *conn = hcon->l2cap_data;
7418
7419 BT_DBG("hcon %p", hcon);
7420
7421 if (!conn)
7422 return HCI_ERROR_REMOTE_USER_TERM;
7423 return conn->disc_reason;
7424 }
7425
7426 static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)
7427 {
7428 if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
7429 return;
7430
7431 BT_DBG("hcon %p reason %d", hcon, reason);
7432
7433 l2cap_conn_del(hcon, bt_to_errno(reason));
7434 }
7435
7436 static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt)
7437 {
7438 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
7439 return;
7440
7441 if (encrypt == 0x00) {
7442 if (chan->sec_level == BT_SECURITY_MEDIUM) {
7443 __set_chan_timer(chan, L2CAP_ENC_TIMEOUT);
7444 } else if (chan->sec_level == BT_SECURITY_HIGH ||
7445 chan->sec_level == BT_SECURITY_FIPS)
7446 l2cap_chan_close(chan, ECONNREFUSED);
7447 } else {
7448 if (chan->sec_level == BT_SECURITY_MEDIUM)
7449 __clear_chan_timer(chan);
7450 }
7451 }
7452
7453 static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
7454 {
7455 struct l2cap_conn *conn = hcon->l2cap_data;
7456 struct l2cap_chan *chan;
7457
7458 if (!conn)
7459 return;
7460
7461 BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt);
7462
7463 mutex_lock(&conn->chan_lock);
7464
7465 list_for_each_entry(chan, &conn->chan_l, list) {
7466 l2cap_chan_lock(chan);
7467
7468 BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid,
7469 state_to_string(chan->state));
7470
7471 if (chan->scid == L2CAP_CID_A2MP) {
7472 l2cap_chan_unlock(chan);
7473 continue;
7474 }
7475
7476 if (!status && encrypt)
7477 chan->sec_level = hcon->sec_level;
7478
7479 if (!__l2cap_no_conn_pending(chan)) {
7480 l2cap_chan_unlock(chan);
7481 continue;
7482 }
7483
7484 if (!status && (chan->state == BT_CONNECTED ||
7485 chan->state == BT_CONFIG)) {
7486 chan->ops->resume(chan);
7487 l2cap_check_encryption(chan, encrypt);
7488 l2cap_chan_unlock(chan);
7489 continue;
7490 }
7491
7492 if (chan->state == BT_CONNECT) {
7493 if (!status)
7494 l2cap_start_connection(chan);
7495 else
7496 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
7497 } else if (chan->state == BT_CONNECT2 &&
7498 chan->mode != L2CAP_MODE_LE_FLOWCTL) {
7499 struct l2cap_conn_rsp rsp;
7500 __u16 res, stat;
7501
7502 if (!status) {
7503 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
7504 res = L2CAP_CR_PEND;
7505 stat = L2CAP_CS_AUTHOR_PEND;
7506 chan->ops->defer(chan);
7507 } else {
7508 l2cap_state_change(chan, BT_CONFIG);
7509 res = L2CAP_CR_SUCCESS;
7510 stat = L2CAP_CS_NO_INFO;
7511 }
7512 } else {
7513 l2cap_state_change(chan, BT_DISCONN);
7514 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
7515 res = L2CAP_CR_SEC_BLOCK;
7516 stat = L2CAP_CS_NO_INFO;
7517 }
7518
7519 rsp.scid = cpu_to_le16(chan->dcid);
7520 rsp.dcid = cpu_to_le16(chan->scid);
7521 rsp.result = cpu_to_le16(res);
7522 rsp.status = cpu_to_le16(stat);
7523 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
7524 sizeof(rsp), &rsp);
7525
7526 if (!test_bit(CONF_REQ_SENT, &chan->conf_state) &&
7527 res == L2CAP_CR_SUCCESS) {
7528 char buf[128];
7529 set_bit(CONF_REQ_SENT, &chan->conf_state);
7530 l2cap_send_cmd(conn, l2cap_get_ident(conn),
7531 L2CAP_CONF_REQ,
7532 l2cap_build_conf_req(chan, buf, sizeof(buf)),
7533 buf);
7534 chan->num_conf_req++;
7535 }
7536 }
7537
7538 l2cap_chan_unlock(chan);
7539 }
7540
7541 mutex_unlock(&conn->chan_lock);
7542 }
7543
7544 void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
7545 {
7546 struct l2cap_conn *conn = hcon->l2cap_data;
7547 struct l2cap_hdr *hdr;
7548 int len;
7549
7550 /* For AMP controller do not create l2cap conn */
7551 if (!conn && hcon->hdev->dev_type != HCI_PRIMARY)
7552 goto drop;
7553
7554 if (!conn)
7555 conn = l2cap_conn_add(hcon);
7556
7557 if (!conn)
7558 goto drop;
7559
7560 BT_DBG("conn %p len %d flags 0x%x", conn, skb->len, flags);
7561
7562 switch (flags) {
7563 case ACL_START:
7564 case ACL_START_NO_FLUSH:
7565 case ACL_COMPLETE:
7566 if (conn->rx_len) {
7567 BT_ERR("Unexpected start frame (len %d)", skb->len);
7568 kfree_skb(conn->rx_skb);
7569 conn->rx_skb = NULL;
7570 conn->rx_len = 0;
7571 l2cap_conn_unreliable(conn, ECOMM);
7572 }
7573
7574 /* Start fragment always begin with Basic L2CAP header */
7575 if (skb->len < L2CAP_HDR_SIZE) {
7576 BT_ERR("Frame is too short (len %d)", skb->len);
7577 l2cap_conn_unreliable(conn, ECOMM);
7578 goto drop;
7579 }
7580
7581 hdr = (struct l2cap_hdr *) skb->data;
7582 len = __le16_to_cpu(hdr->len) + L2CAP_HDR_SIZE;
7583
7584 if (len == skb->len) {
7585 /* Complete frame received */
7586 l2cap_recv_frame(conn, skb);
7587 return;
7588 }
7589
7590 BT_DBG("Start: total len %d, frag len %d", len, skb->len);
7591
7592 if (skb->len > len) {
7593 BT_ERR("Frame is too long (len %d, expected len %d)",
7594 skb->len, len);
7595 l2cap_conn_unreliable(conn, ECOMM);
7596 goto drop;
7597 }
7598
7599 /* Allocate skb for the complete frame (with header) */
7600 conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL);
7601 if (!conn->rx_skb)
7602 goto drop;
7603
7604 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len),
7605 skb->len);
7606 conn->rx_len = len - skb->len;
7607 break;
7608
7609 case ACL_CONT:
7610 BT_DBG("Cont: frag len %d (expecting %d)", skb->len, conn->rx_len);
7611
7612 if (!conn->rx_len) {
7613 BT_ERR("Unexpected continuation frame (len %d)", skb->len);
7614 l2cap_conn_unreliable(conn, ECOMM);
7615 goto drop;
7616 }
7617
7618 if (skb->len > conn->rx_len) {
7619 BT_ERR("Fragment is too long (len %d, expected %d)",
7620 skb->len, conn->rx_len);
7621 kfree_skb(conn->rx_skb);
7622 conn->rx_skb = NULL;
7623 conn->rx_len = 0;
7624 l2cap_conn_unreliable(conn, ECOMM);
7625 goto drop;
7626 }
7627
7628 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len),
7629 skb->len);
7630 conn->rx_len -= skb->len;
7631
7632 if (!conn->rx_len) {
7633 /* Complete frame received. l2cap_recv_frame
7634 * takes ownership of the skb so set the global
7635 * rx_skb pointer to NULL first.
7636 */
7637 struct sk_buff *rx_skb = conn->rx_skb;
7638 conn->rx_skb = NULL;
7639 l2cap_recv_frame(conn, rx_skb);
7640 }
7641 break;
7642 }
7643
7644 drop:
7645 kfree_skb(skb);
7646 }
7647
7648 static struct hci_cb l2cap_cb = {
7649 .name = "L2CAP",
7650 .connect_cfm = l2cap_connect_cfm,
7651 .disconn_cfm = l2cap_disconn_cfm,
7652 .security_cfm = l2cap_security_cfm,
7653 };
7654
7655 static int l2cap_debugfs_show(struct seq_file *f, void *p)
7656 {
7657 struct l2cap_chan *c;
7658
7659 read_lock(&chan_list_lock);
7660
7661 list_for_each_entry(c, &chan_list, global_l) {
7662 seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n",
7663 &c->src, c->src_type, &c->dst, c->dst_type,
7664 c->state, __le16_to_cpu(c->psm),
7665 c->scid, c->dcid, c->imtu, c->omtu,
7666 c->sec_level, c->mode);
7667 }
7668
7669 read_unlock(&chan_list_lock);
7670
7671 return 0;
7672 }
7673
7674 DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs);
7675
7676 static struct dentry *l2cap_debugfs;
7677
7678 int __init l2cap_init(void)
7679 {
7680 int err;
7681
7682 err = l2cap_init_sockets();
7683 if (err < 0)
7684 return err;
7685
7686 hci_register_cb(&l2cap_cb);
7687
7688 if (IS_ERR_OR_NULL(bt_debugfs))
7689 return 0;
7690
7691 l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs,
7692 NULL, &l2cap_debugfs_fops);
7693
7694 return 0;
7695 }
7696
7697 void l2cap_exit(void)
7698 {
7699 debugfs_remove(l2cap_debugfs);
7700 hci_unregister_cb(&l2cap_cb);
7701 l2cap_cleanup_sockets();
7702 }
7703
7704 module_param(disable_ertm, bool, 0644);
7705 MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode");
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