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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
47bool disable_ertm;
48
49static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN | L2CAP_FEAT_UCD;
50
51static LIST_HEAD(chan_list);
52static DEFINE_RWLOCK(chan_list_lock);
53
54static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
55 u8 code, u8 ident, u16 dlen, void *data);
56static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
57 void *data);
58static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size);
59static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err);
60
61static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
62 struct sk_buff_head *skbs, u8 event);
63
64static 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
76static inline u8 bdaddr_src_type(struct hci_conn *hcon)
77{
78 return bdaddr_type(hcon->type, hcon->src_type);
79}
80
81static 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
88static 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
100static 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. */
114static 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 */
131static 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
145static 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
157static 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
171static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src,
172 u8 src_type)
173{
174 struct l2cap_chan *c;
175
176 list_for_each_entry(c, &chan_list, global_l) {
177 if (src_type == BDADDR_BREDR && c->src_type != BDADDR_BREDR)
178 continue;
179
180 if (src_type != BDADDR_BREDR && c->src_type == BDADDR_BREDR)
181 continue;
182
183 if (c->sport == psm && !bacmp(&c->src, src))
184 return c;
185 }
186 return NULL;
187}
188
189int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm)
190{
191 int err;
192
193 write_lock(&chan_list_lock);
194
195 if (psm && __l2cap_global_chan_by_addr(psm, src, chan->src_type)) {
196 err = -EADDRINUSE;
197 goto done;
198 }
199
200 if (psm) {
201 chan->psm = psm;
202 chan->sport = psm;
203 err = 0;
204 } else {
205 u16 p, start, end, incr;
206
207 if (chan->src_type == BDADDR_BREDR) {
208 start = L2CAP_PSM_DYN_START;
209 end = L2CAP_PSM_AUTO_END;
210 incr = 2;
211 } else {
212 start = L2CAP_PSM_LE_DYN_START;
213 end = L2CAP_PSM_LE_DYN_END;
214 incr = 1;
215 }
216
217 err = -EINVAL;
218 for (p = start; p <= end; p += incr)
219 if (!__l2cap_global_chan_by_addr(cpu_to_le16(p), src,
220 chan->src_type)) {
221 chan->psm = cpu_to_le16(p);
222 chan->sport = cpu_to_le16(p);
223 err = 0;
224 break;
225 }
226 }
227
228done:
229 write_unlock(&chan_list_lock);
230 return err;
231}
232EXPORT_SYMBOL_GPL(l2cap_add_psm);
233
234int l2cap_add_scid(struct l2cap_chan *chan, __u16 scid)
235{
236 write_lock(&chan_list_lock);
237
238 /* Override the defaults (which are for conn-oriented) */
239 chan->omtu = L2CAP_DEFAULT_MTU;
240 chan->chan_type = L2CAP_CHAN_FIXED;
241
242 chan->scid = scid;
243
244 write_unlock(&chan_list_lock);
245
246 return 0;
247}
248
249static u16 l2cap_alloc_cid(struct l2cap_conn *conn)
250{
251 u16 cid, dyn_end;
252
253 if (conn->hcon->type == LE_LINK)
254 dyn_end = L2CAP_CID_LE_DYN_END;
255 else
256 dyn_end = L2CAP_CID_DYN_END;
257
258 for (cid = L2CAP_CID_DYN_START; cid <= dyn_end; cid++) {
259 if (!__l2cap_get_chan_by_scid(conn, cid))
260 return cid;
261 }
262
263 return 0;
264}
265
266static void l2cap_state_change(struct l2cap_chan *chan, int state)
267{
268 BT_DBG("chan %p %s -> %s", chan, state_to_string(chan->state),
269 state_to_string(state));
270
271 chan->state = state;
272 chan->ops->state_change(chan, state, 0);
273}
274
275static inline void l2cap_state_change_and_error(struct l2cap_chan *chan,
276 int state, int err)
277{
278 chan->state = state;
279 chan->ops->state_change(chan, chan->state, err);
280}
281
282static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
283{
284 chan->ops->state_change(chan, chan->state, err);
285}
286
287static void __set_retrans_timer(struct l2cap_chan *chan)
288{
289 if (!delayed_work_pending(&chan->monitor_timer) &&
290 chan->retrans_timeout) {
291 l2cap_set_timer(chan, &chan->retrans_timer,
292 msecs_to_jiffies(chan->retrans_timeout));
293 }
294}
295
296static void __set_monitor_timer(struct l2cap_chan *chan)
297{
298 __clear_retrans_timer(chan);
299 if (chan->monitor_timeout) {
300 l2cap_set_timer(chan, &chan->monitor_timer,
301 msecs_to_jiffies(chan->monitor_timeout));
302 }
303}
304
305static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head,
306 u16 seq)
307{
308 struct sk_buff *skb;
309
310 skb_queue_walk(head, skb) {
311 if (bt_cb(skb)->l2cap.txseq == seq)
312 return skb;
313 }
314
315 return NULL;
316}
317
318/* ---- L2CAP sequence number lists ---- */
319
320/* For ERTM, ordered lists of sequence numbers must be tracked for
321 * SREJ requests that are received and for frames that are to be
322 * retransmitted. These seq_list functions implement a singly-linked
323 * list in an array, where membership in the list can also be checked
324 * in constant time. Items can also be added to the tail of the list
325 * and removed from the head in constant time, without further memory
326 * allocs or frees.
327 */
328
329static int l2cap_seq_list_init(struct l2cap_seq_list *seq_list, u16 size)
330{
331 size_t alloc_size, i;
332
333 /* Allocated size is a power of 2 to map sequence numbers
334 * (which may be up to 14 bits) in to a smaller array that is
335 * sized for the negotiated ERTM transmit windows.
336 */
337 alloc_size = roundup_pow_of_two(size);
338
339 seq_list->list = kmalloc_array(alloc_size, sizeof(u16), GFP_KERNEL);
340 if (!seq_list->list)
341 return -ENOMEM;
342
343 seq_list->mask = alloc_size - 1;
344 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
345 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
346 for (i = 0; i < alloc_size; i++)
347 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
348
349 return 0;
350}
351
352static inline void l2cap_seq_list_free(struct l2cap_seq_list *seq_list)
353{
354 kfree(seq_list->list);
355}
356
357static inline bool l2cap_seq_list_contains(struct l2cap_seq_list *seq_list,
358 u16 seq)
359{
360 /* Constant-time check for list membership */
361 return seq_list->list[seq & seq_list->mask] != L2CAP_SEQ_LIST_CLEAR;
362}
363
364static inline u16 l2cap_seq_list_pop(struct l2cap_seq_list *seq_list)
365{
366 u16 seq = seq_list->head;
367 u16 mask = seq_list->mask;
368
369 seq_list->head = seq_list->list[seq & mask];
370 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_CLEAR;
371
372 if (seq_list->head == L2CAP_SEQ_LIST_TAIL) {
373 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
374 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
375 }
376
377 return seq;
378}
379
380static void l2cap_seq_list_clear(struct l2cap_seq_list *seq_list)
381{
382 u16 i;
383
384 if (seq_list->head == L2CAP_SEQ_LIST_CLEAR)
385 return;
386
387 for (i = 0; i <= seq_list->mask; i++)
388 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
389
390 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
391 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
392}
393
394static void l2cap_seq_list_append(struct l2cap_seq_list *seq_list, u16 seq)
395{
396 u16 mask = seq_list->mask;
397
398 /* All appends happen in constant time */
399
400 if (seq_list->list[seq & mask] != L2CAP_SEQ_LIST_CLEAR)
401 return;
402
403 if (seq_list->tail == L2CAP_SEQ_LIST_CLEAR)
404 seq_list->head = seq;
405 else
406 seq_list->list[seq_list->tail & mask] = seq;
407
408 seq_list->tail = seq;
409 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_TAIL;
410}
411
412static void l2cap_chan_timeout(struct work_struct *work)
413{
414 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
415 chan_timer.work);
416 struct l2cap_conn *conn = chan->conn;
417 int reason;
418
419 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
420
421 mutex_lock(&conn->chan_lock);
422 l2cap_chan_lock(chan);
423
424 if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
425 reason = ECONNREFUSED;
426 else if (chan->state == BT_CONNECT &&
427 chan->sec_level != BT_SECURITY_SDP)
428 reason = ECONNREFUSED;
429 else
430 reason = ETIMEDOUT;
431
432 l2cap_chan_close(chan, reason);
433
434 l2cap_chan_unlock(chan);
435
436 chan->ops->close(chan);
437 mutex_unlock(&conn->chan_lock);
438
439 l2cap_chan_put(chan);
440}
441
442struct l2cap_chan *l2cap_chan_create(void)
443{
444 struct l2cap_chan *chan;
445
446 chan = kzalloc(sizeof(*chan), GFP_ATOMIC);
447 if (!chan)
448 return NULL;
449
450 mutex_init(&chan->lock);
451
452 /* Set default lock nesting level */
453 atomic_set(&chan->nesting, L2CAP_NESTING_NORMAL);
454
455 write_lock(&chan_list_lock);
456 list_add(&chan->global_l, &chan_list);
457 write_unlock(&chan_list_lock);
458
459 INIT_DELAYED_WORK(&chan->chan_timer, l2cap_chan_timeout);
460
461 chan->state = BT_OPEN;
462
463 kref_init(&chan->kref);
464
465 /* This flag is cleared in l2cap_chan_ready() */
466 set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
467
468 BT_DBG("chan %p", chan);
469
470 return chan;
471}
472EXPORT_SYMBOL_GPL(l2cap_chan_create);
473
474static void l2cap_chan_destroy(struct kref *kref)
475{
476 struct l2cap_chan *chan = container_of(kref, struct l2cap_chan, kref);
477
478 BT_DBG("chan %p", chan);
479
480 write_lock(&chan_list_lock);
481 list_del(&chan->global_l);
482 write_unlock(&chan_list_lock);
483
484 kfree(chan);
485}
486
487void l2cap_chan_hold(struct l2cap_chan *c)
488{
489 BT_DBG("chan %p orig refcnt %d", c, kref_read(&c->kref));
490
491 kref_get(&c->kref);
492}
493
494void l2cap_chan_put(struct l2cap_chan *c)
495{
496 BT_DBG("chan %p orig refcnt %d", c, kref_read(&c->kref));
497
498 kref_put(&c->kref, l2cap_chan_destroy);
499}
500EXPORT_SYMBOL_GPL(l2cap_chan_put);
501
502void l2cap_chan_set_defaults(struct l2cap_chan *chan)
503{
504 chan->fcs = L2CAP_FCS_CRC16;
505 chan->max_tx = L2CAP_DEFAULT_MAX_TX;
506 chan->tx_win = L2CAP_DEFAULT_TX_WINDOW;
507 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
508 chan->remote_max_tx = chan->max_tx;
509 chan->remote_tx_win = chan->tx_win;
510 chan->ack_win = L2CAP_DEFAULT_TX_WINDOW;
511 chan->sec_level = BT_SECURITY_LOW;
512 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
513 chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO;
514 chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO;
515 chan->conf_state = 0;
516
517 set_bit(FLAG_FORCE_ACTIVE, &chan->flags);
518}
519EXPORT_SYMBOL_GPL(l2cap_chan_set_defaults);
520
521static void l2cap_le_flowctl_init(struct l2cap_chan *chan, u16 tx_credits)
522{
523 chan->sdu = NULL;
524 chan->sdu_last_frag = NULL;
525 chan->sdu_len = 0;
526 chan->tx_credits = tx_credits;
527 /* Derive MPS from connection MTU to stop HCI fragmentation */
528 chan->mps = min_t(u16, chan->imtu, chan->conn->mtu - L2CAP_HDR_SIZE);
529 /* Give enough credits for a full packet */
530 chan->rx_credits = (chan->imtu / chan->mps) + 1;
531
532 skb_queue_head_init(&chan->tx_q);
533}
534
535void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
536{
537 BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn,
538 __le16_to_cpu(chan->psm), chan->dcid);
539
540 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
541
542 chan->conn = conn;
543
544 switch (chan->chan_type) {
545 case L2CAP_CHAN_CONN_ORIENTED:
546 /* Alloc CID for connection-oriented socket */
547 chan->scid = l2cap_alloc_cid(conn);
548 if (conn->hcon->type == ACL_LINK)
549 chan->omtu = L2CAP_DEFAULT_MTU;
550 break;
551
552 case L2CAP_CHAN_CONN_LESS:
553 /* Connectionless socket */
554 chan->scid = L2CAP_CID_CONN_LESS;
555 chan->dcid = L2CAP_CID_CONN_LESS;
556 chan->omtu = L2CAP_DEFAULT_MTU;
557 break;
558
559 case L2CAP_CHAN_FIXED:
560 /* Caller will set CID and CID specific MTU values */
561 break;
562
563 default:
564 /* Raw socket can send/recv signalling messages only */
565 chan->scid = L2CAP_CID_SIGNALING;
566 chan->dcid = L2CAP_CID_SIGNALING;
567 chan->omtu = L2CAP_DEFAULT_MTU;
568 }
569
570 chan->local_id = L2CAP_BESTEFFORT_ID;
571 chan->local_stype = L2CAP_SERV_BESTEFFORT;
572 chan->local_msdu = L2CAP_DEFAULT_MAX_SDU_SIZE;
573 chan->local_sdu_itime = L2CAP_DEFAULT_SDU_ITIME;
574 chan->local_acc_lat = L2CAP_DEFAULT_ACC_LAT;
575 chan->local_flush_to = L2CAP_EFS_DEFAULT_FLUSH_TO;
576
577 l2cap_chan_hold(chan);
578
579 /* Only keep a reference for fixed channels if they requested it */
580 if (chan->chan_type != L2CAP_CHAN_FIXED ||
581 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
582 hci_conn_hold(conn->hcon);
583
584 list_add(&chan->list, &conn->chan_l);
585}
586
587void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
588{
589 mutex_lock(&conn->chan_lock);
590 __l2cap_chan_add(conn, chan);
591 mutex_unlock(&conn->chan_lock);
592}
593
594void l2cap_chan_del(struct l2cap_chan *chan, int err)
595{
596 struct l2cap_conn *conn = chan->conn;
597
598 __clear_chan_timer(chan);
599
600 BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err,
601 state_to_string(chan->state));
602
603 chan->ops->teardown(chan, err);
604
605 if (conn) {
606 struct amp_mgr *mgr = conn->hcon->amp_mgr;
607 /* Delete from channel list */
608 list_del(&chan->list);
609
610 l2cap_chan_put(chan);
611
612 chan->conn = NULL;
613
614 /* Reference was only held for non-fixed channels or
615 * fixed channels that explicitly requested it using the
616 * FLAG_HOLD_HCI_CONN flag.
617 */
618 if (chan->chan_type != L2CAP_CHAN_FIXED ||
619 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
620 hci_conn_drop(conn->hcon);
621
622 if (mgr && mgr->bredr_chan == chan)
623 mgr->bredr_chan = NULL;
624 }
625
626 if (chan->hs_hchan) {
627 struct hci_chan *hs_hchan = chan->hs_hchan;
628
629 BT_DBG("chan %p disconnect hs_hchan %p", chan, hs_hchan);
630 amp_disconnect_logical_link(hs_hchan);
631 }
632
633 if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state))
634 return;
635
636 switch(chan->mode) {
637 case L2CAP_MODE_BASIC:
638 break;
639
640 case L2CAP_MODE_LE_FLOWCTL:
641 skb_queue_purge(&chan->tx_q);
642 break;
643
644 case L2CAP_MODE_ERTM:
645 __clear_retrans_timer(chan);
646 __clear_monitor_timer(chan);
647 __clear_ack_timer(chan);
648
649 skb_queue_purge(&chan->srej_q);
650
651 l2cap_seq_list_free(&chan->srej_list);
652 l2cap_seq_list_free(&chan->retrans_list);
653
654 /* fall through */
655
656 case L2CAP_MODE_STREAMING:
657 skb_queue_purge(&chan->tx_q);
658 break;
659 }
660
661 return;
662}
663EXPORT_SYMBOL_GPL(l2cap_chan_del);
664
665static void l2cap_conn_update_id_addr(struct work_struct *work)
666{
667 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
668 id_addr_update_work);
669 struct hci_conn *hcon = conn->hcon;
670 struct l2cap_chan *chan;
671
672 mutex_lock(&conn->chan_lock);
673
674 list_for_each_entry(chan, &conn->chan_l, list) {
675 l2cap_chan_lock(chan);
676 bacpy(&chan->dst, &hcon->dst);
677 chan->dst_type = bdaddr_dst_type(hcon);
678 l2cap_chan_unlock(chan);
679 }
680
681 mutex_unlock(&conn->chan_lock);
682}
683
684static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan)
685{
686 struct l2cap_conn *conn = chan->conn;
687 struct l2cap_le_conn_rsp rsp;
688 u16 result;
689
690 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
691 result = L2CAP_CR_LE_AUTHORIZATION;
692 else
693 result = L2CAP_CR_LE_BAD_PSM;
694
695 l2cap_state_change(chan, BT_DISCONN);
696
697 rsp.dcid = cpu_to_le16(chan->scid);
698 rsp.mtu = cpu_to_le16(chan->imtu);
699 rsp.mps = cpu_to_le16(chan->mps);
700 rsp.credits = cpu_to_le16(chan->rx_credits);
701 rsp.result = cpu_to_le16(result);
702
703 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
704 &rsp);
705}
706
707static void l2cap_chan_connect_reject(struct l2cap_chan *chan)
708{
709 struct l2cap_conn *conn = chan->conn;
710 struct l2cap_conn_rsp rsp;
711 u16 result;
712
713 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
714 result = L2CAP_CR_SEC_BLOCK;
715 else
716 result = L2CAP_CR_BAD_PSM;
717
718 l2cap_state_change(chan, BT_DISCONN);
719
720 rsp.scid = cpu_to_le16(chan->dcid);
721 rsp.dcid = cpu_to_le16(chan->scid);
722 rsp.result = cpu_to_le16(result);
723 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
724
725 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, sizeof(rsp), &rsp);
726}
727
728void l2cap_chan_close(struct l2cap_chan *chan, int reason)
729{
730 struct l2cap_conn *conn = chan->conn;
731
732 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
733
734 switch (chan->state) {
735 case BT_LISTEN:
736 chan->ops->teardown(chan, 0);
737 break;
738
739 case BT_CONNECTED:
740 case BT_CONFIG:
741 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
742 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
743 l2cap_send_disconn_req(chan, reason);
744 } else
745 l2cap_chan_del(chan, reason);
746 break;
747
748 case BT_CONNECT2:
749 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
750 if (conn->hcon->type == ACL_LINK)
751 l2cap_chan_connect_reject(chan);
752 else if (conn->hcon->type == LE_LINK)
753 l2cap_chan_le_connect_reject(chan);
754 }
755
756 l2cap_chan_del(chan, reason);
757 break;
758
759 case BT_CONNECT:
760 case BT_DISCONN:
761 l2cap_chan_del(chan, reason);
762 break;
763
764 default:
765 chan->ops->teardown(chan, 0);
766 break;
767 }
768}
769EXPORT_SYMBOL(l2cap_chan_close);
770
771static inline u8 l2cap_get_auth_type(struct l2cap_chan *chan)
772{
773 switch (chan->chan_type) {
774 case L2CAP_CHAN_RAW:
775 switch (chan->sec_level) {
776 case BT_SECURITY_HIGH:
777 case BT_SECURITY_FIPS:
778 return HCI_AT_DEDICATED_BONDING_MITM;
779 case BT_SECURITY_MEDIUM:
780 return HCI_AT_DEDICATED_BONDING;
781 default:
782 return HCI_AT_NO_BONDING;
783 }
784 break;
785 case L2CAP_CHAN_CONN_LESS:
786 if (chan->psm == cpu_to_le16(L2CAP_PSM_3DSP)) {
787 if (chan->sec_level == BT_SECURITY_LOW)
788 chan->sec_level = BT_SECURITY_SDP;
789 }
790 if (chan->sec_level == BT_SECURITY_HIGH ||
791 chan->sec_level == BT_SECURITY_FIPS)
792 return HCI_AT_NO_BONDING_MITM;
793 else
794 return HCI_AT_NO_BONDING;
795 break;
796 case L2CAP_CHAN_CONN_ORIENTED:
797 if (chan->psm == cpu_to_le16(L2CAP_PSM_SDP)) {
798 if (chan->sec_level == BT_SECURITY_LOW)
799 chan->sec_level = BT_SECURITY_SDP;
800
801 if (chan->sec_level == BT_SECURITY_HIGH ||
802 chan->sec_level == BT_SECURITY_FIPS)
803 return HCI_AT_NO_BONDING_MITM;
804 else
805 return HCI_AT_NO_BONDING;
806 }
807 /* fall through */
808 default:
809 switch (chan->sec_level) {
810 case BT_SECURITY_HIGH:
811 case BT_SECURITY_FIPS:
812 return HCI_AT_GENERAL_BONDING_MITM;
813 case BT_SECURITY_MEDIUM:
814 return HCI_AT_GENERAL_BONDING;
815 default:
816 return HCI_AT_NO_BONDING;
817 }
818 break;
819 }
820}
821
822/* Service level security */
823int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator)
824{
825 struct l2cap_conn *conn = chan->conn;
826 __u8 auth_type;
827
828 if (conn->hcon->type == LE_LINK)
829 return smp_conn_security(conn->hcon, chan->sec_level);
830
831 auth_type = l2cap_get_auth_type(chan);
832
833 return hci_conn_security(conn->hcon, chan->sec_level, auth_type,
834 initiator);
835}
836
837static u8 l2cap_get_ident(struct l2cap_conn *conn)
838{
839 u8 id;
840
841 /* Get next available identificator.
842 * 1 - 128 are used by kernel.
843 * 129 - 199 are reserved.
844 * 200 - 254 are used by utilities like l2ping, etc.
845 */
846
847 mutex_lock(&conn->ident_lock);
848
849 if (++conn->tx_ident > 128)
850 conn->tx_ident = 1;
851
852 id = conn->tx_ident;
853
854 mutex_unlock(&conn->ident_lock);
855
856 return id;
857}
858
859static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
860 void *data)
861{
862 struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data);
863 u8 flags;
864
865 BT_DBG("code 0x%2.2x", code);
866
867 if (!skb)
868 return;
869
870 /* Use NO_FLUSH if supported or we have an LE link (which does
871 * not support auto-flushing packets) */
872 if (lmp_no_flush_capable(conn->hcon->hdev) ||
873 conn->hcon->type == LE_LINK)
874 flags = ACL_START_NO_FLUSH;
875 else
876 flags = ACL_START;
877
878 bt_cb(skb)->force_active = BT_POWER_FORCE_ACTIVE_ON;
879 skb->priority = HCI_PRIO_MAX;
880
881 hci_send_acl(conn->hchan, skb, flags);
882}
883
884static bool __chan_is_moving(struct l2cap_chan *chan)
885{
886 return chan->move_state != L2CAP_MOVE_STABLE &&
887 chan->move_state != L2CAP_MOVE_WAIT_PREPARE;
888}
889
890static void l2cap_do_send(struct l2cap_chan *chan, struct sk_buff *skb)
891{
892 struct hci_conn *hcon = chan->conn->hcon;
893 u16 flags;
894
895 BT_DBG("chan %p, skb %p len %d priority %u", chan, skb, skb->len,
896 skb->priority);
897
898 if (chan->hs_hcon && !__chan_is_moving(chan)) {
899 if (chan->hs_hchan)
900 hci_send_acl(chan->hs_hchan, skb, ACL_COMPLETE);
901 else
902 kfree_skb(skb);
903
904 return;
905 }
906
907 /* Use NO_FLUSH for LE links (where this is the only option) or
908 * if the BR/EDR link supports it and flushing has not been
909 * explicitly requested (through FLAG_FLUSHABLE).
910 */
911 if (hcon->type == LE_LINK ||
912 (!test_bit(FLAG_FLUSHABLE, &chan->flags) &&
913 lmp_no_flush_capable(hcon->hdev)))
914 flags = ACL_START_NO_FLUSH;
915 else
916 flags = ACL_START;
917
918 bt_cb(skb)->force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags);
919 hci_send_acl(chan->conn->hchan, skb, flags);
920}
921
922static void __unpack_enhanced_control(u16 enh, struct l2cap_ctrl *control)
923{
924 control->reqseq = (enh & L2CAP_CTRL_REQSEQ) >> L2CAP_CTRL_REQSEQ_SHIFT;
925 control->final = (enh & L2CAP_CTRL_FINAL) >> L2CAP_CTRL_FINAL_SHIFT;
926
927 if (enh & L2CAP_CTRL_FRAME_TYPE) {
928 /* S-Frame */
929 control->sframe = 1;
930 control->poll = (enh & L2CAP_CTRL_POLL) >> L2CAP_CTRL_POLL_SHIFT;
931 control->super = (enh & L2CAP_CTRL_SUPERVISE) >> L2CAP_CTRL_SUPER_SHIFT;
932
933 control->sar = 0;
934 control->txseq = 0;
935 } else {
936 /* I-Frame */
937 control->sframe = 0;
938 control->sar = (enh & L2CAP_CTRL_SAR) >> L2CAP_CTRL_SAR_SHIFT;
939 control->txseq = (enh & L2CAP_CTRL_TXSEQ) >> L2CAP_CTRL_TXSEQ_SHIFT;
940
941 control->poll = 0;
942 control->super = 0;
943 }
944}
945
946static void __unpack_extended_control(u32 ext, struct l2cap_ctrl *control)
947{
948 control->reqseq = (ext & L2CAP_EXT_CTRL_REQSEQ) >> L2CAP_EXT_CTRL_REQSEQ_SHIFT;
949 control->final = (ext & L2CAP_EXT_CTRL_FINAL) >> L2CAP_EXT_CTRL_FINAL_SHIFT;
950
951 if (ext & L2CAP_EXT_CTRL_FRAME_TYPE) {
952 /* S-Frame */
953 control->sframe = 1;
954 control->poll = (ext & L2CAP_EXT_CTRL_POLL) >> L2CAP_EXT_CTRL_POLL_SHIFT;
955 control->super = (ext & L2CAP_EXT_CTRL_SUPERVISE) >> L2CAP_EXT_CTRL_SUPER_SHIFT;
956
957 control->sar = 0;
958 control->txseq = 0;
959 } else {
960 /* I-Frame */
961 control->sframe = 0;
962 control->sar = (ext & L2CAP_EXT_CTRL_SAR) >> L2CAP_EXT_CTRL_SAR_SHIFT;
963 control->txseq = (ext & L2CAP_EXT_CTRL_TXSEQ) >> L2CAP_EXT_CTRL_TXSEQ_SHIFT;
964
965 control->poll = 0;
966 control->super = 0;
967 }
968}
969
970static inline void __unpack_control(struct l2cap_chan *chan,
971 struct sk_buff *skb)
972{
973 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
974 __unpack_extended_control(get_unaligned_le32(skb->data),
975 &bt_cb(skb)->l2cap);
976 skb_pull(skb, L2CAP_EXT_CTRL_SIZE);
977 } else {
978 __unpack_enhanced_control(get_unaligned_le16(skb->data),
979 &bt_cb(skb)->l2cap);
980 skb_pull(skb, L2CAP_ENH_CTRL_SIZE);
981 }
982}
983
984static u32 __pack_extended_control(struct l2cap_ctrl *control)
985{
986 u32 packed;
987
988 packed = control->reqseq << L2CAP_EXT_CTRL_REQSEQ_SHIFT;
989 packed |= control->final << L2CAP_EXT_CTRL_FINAL_SHIFT;
990
991 if (control->sframe) {
992 packed |= control->poll << L2CAP_EXT_CTRL_POLL_SHIFT;
993 packed |= control->super << L2CAP_EXT_CTRL_SUPER_SHIFT;
994 packed |= L2CAP_EXT_CTRL_FRAME_TYPE;
995 } else {
996 packed |= control->sar << L2CAP_EXT_CTRL_SAR_SHIFT;
997 packed |= control->txseq << L2CAP_EXT_CTRL_TXSEQ_SHIFT;
998 }
999
1000 return packed;
1001}
1002
1003static u16 __pack_enhanced_control(struct l2cap_ctrl *control)
1004{
1005 u16 packed;
1006
1007 packed = control->reqseq << L2CAP_CTRL_REQSEQ_SHIFT;
1008 packed |= control->final << L2CAP_CTRL_FINAL_SHIFT;
1009
1010 if (control->sframe) {
1011 packed |= control->poll << L2CAP_CTRL_POLL_SHIFT;
1012 packed |= control->super << L2CAP_CTRL_SUPER_SHIFT;
1013 packed |= L2CAP_CTRL_FRAME_TYPE;
1014 } else {
1015 packed |= control->sar << L2CAP_CTRL_SAR_SHIFT;
1016 packed |= control->txseq << L2CAP_CTRL_TXSEQ_SHIFT;
1017 }
1018
1019 return packed;
1020}
1021
1022static inline void __pack_control(struct l2cap_chan *chan,
1023 struct l2cap_ctrl *control,
1024 struct sk_buff *skb)
1025{
1026 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
1027 put_unaligned_le32(__pack_extended_control(control),
1028 skb->data + L2CAP_HDR_SIZE);
1029 } else {
1030 put_unaligned_le16(__pack_enhanced_control(control),
1031 skb->data + L2CAP_HDR_SIZE);
1032 }
1033}
1034
1035static inline unsigned int __ertm_hdr_size(struct l2cap_chan *chan)
1036{
1037 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1038 return L2CAP_EXT_HDR_SIZE;
1039 else
1040 return L2CAP_ENH_HDR_SIZE;
1041}
1042
1043static struct sk_buff *l2cap_create_sframe_pdu(struct l2cap_chan *chan,
1044 u32 control)
1045{
1046 struct sk_buff *skb;
1047 struct l2cap_hdr *lh;
1048 int hlen = __ertm_hdr_size(chan);
1049
1050 if (chan->fcs == L2CAP_FCS_CRC16)
1051 hlen += L2CAP_FCS_SIZE;
1052
1053 skb = bt_skb_alloc(hlen, GFP_KERNEL);
1054
1055 if (!skb)
1056 return ERR_PTR(-ENOMEM);
1057
1058 lh = skb_put(skb, L2CAP_HDR_SIZE);
1059 lh->len = cpu_to_le16(hlen - L2CAP_HDR_SIZE);
1060 lh->cid = cpu_to_le16(chan->dcid);
1061
1062 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1063 put_unaligned_le32(control, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
1064 else
1065 put_unaligned_le16(control, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
1066
1067 if (chan->fcs == L2CAP_FCS_CRC16) {
1068 u16 fcs = crc16(0, (u8 *)skb->data, skb->len);
1069 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1070 }
1071
1072 skb->priority = HCI_PRIO_MAX;
1073 return skb;
1074}
1075
1076static void l2cap_send_sframe(struct l2cap_chan *chan,
1077 struct l2cap_ctrl *control)
1078{
1079 struct sk_buff *skb;
1080 u32 control_field;
1081
1082 BT_DBG("chan %p, control %p", chan, control);
1083
1084 if (!control->sframe)
1085 return;
1086
1087 if (__chan_is_moving(chan))
1088 return;
1089
1090 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state) &&
1091 !control->poll)
1092 control->final = 1;
1093
1094 if (control->super == L2CAP_SUPER_RR)
1095 clear_bit(CONN_RNR_SENT, &chan->conn_state);
1096 else if (control->super == L2CAP_SUPER_RNR)
1097 set_bit(CONN_RNR_SENT, &chan->conn_state);
1098
1099 if (control->super != L2CAP_SUPER_SREJ) {
1100 chan->last_acked_seq = control->reqseq;
1101 __clear_ack_timer(chan);
1102 }
1103
1104 BT_DBG("reqseq %d, final %d, poll %d, super %d", control->reqseq,
1105 control->final, control->poll, control->super);
1106
1107 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1108 control_field = __pack_extended_control(control);
1109 else
1110 control_field = __pack_enhanced_control(control);
1111
1112 skb = l2cap_create_sframe_pdu(chan, control_field);
1113 if (!IS_ERR(skb))
1114 l2cap_do_send(chan, skb);
1115}
1116
1117static void l2cap_send_rr_or_rnr(struct l2cap_chan *chan, bool poll)
1118{
1119 struct l2cap_ctrl control;
1120
1121 BT_DBG("chan %p, poll %d", chan, poll);
1122
1123 memset(&control, 0, sizeof(control));
1124 control.sframe = 1;
1125 control.poll = poll;
1126
1127 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
1128 control.super = L2CAP_SUPER_RNR;
1129 else
1130 control.super = L2CAP_SUPER_RR;
1131
1132 control.reqseq = chan->buffer_seq;
1133 l2cap_send_sframe(chan, &control);
1134}
1135
1136static inline int __l2cap_no_conn_pending(struct l2cap_chan *chan)
1137{
1138 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
1139 return true;
1140
1141 return !test_bit(CONF_CONNECT_PEND, &chan->conf_state);
1142}
1143
1144static bool __amp_capable(struct l2cap_chan *chan)
1145{
1146 struct l2cap_conn *conn = chan->conn;
1147 struct hci_dev *hdev;
1148 bool amp_available = false;
1149
1150 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
1151 return false;
1152
1153 if (!(conn->remote_fixed_chan & L2CAP_FC_A2MP))
1154 return false;
1155
1156 read_lock(&hci_dev_list_lock);
1157 list_for_each_entry(hdev, &hci_dev_list, list) {
1158 if (hdev->amp_type != AMP_TYPE_BREDR &&
1159 test_bit(HCI_UP, &hdev->flags)) {
1160 amp_available = true;
1161 break;
1162 }
1163 }
1164 read_unlock(&hci_dev_list_lock);
1165
1166 if (chan->chan_policy == BT_CHANNEL_POLICY_AMP_PREFERRED)
1167 return amp_available;
1168
1169 return false;
1170}
1171
1172static bool l2cap_check_efs(struct l2cap_chan *chan)
1173{
1174 /* Check EFS parameters */
1175 return true;
1176}
1177
1178void l2cap_send_conn_req(struct l2cap_chan *chan)
1179{
1180 struct l2cap_conn *conn = chan->conn;
1181 struct l2cap_conn_req req;
1182
1183 req.scid = cpu_to_le16(chan->scid);
1184 req.psm = chan->psm;
1185
1186 chan->ident = l2cap_get_ident(conn);
1187
1188 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
1189
1190 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_REQ, sizeof(req), &req);
1191}
1192
1193static void l2cap_send_create_chan_req(struct l2cap_chan *chan, u8 amp_id)
1194{
1195 struct l2cap_create_chan_req req;
1196 req.scid = cpu_to_le16(chan->scid);
1197 req.psm = chan->psm;
1198 req.amp_id = amp_id;
1199
1200 chan->ident = l2cap_get_ident(chan->conn);
1201
1202 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_REQ,
1203 sizeof(req), &req);
1204}
1205
1206static void l2cap_move_setup(struct l2cap_chan *chan)
1207{
1208 struct sk_buff *skb;
1209
1210 BT_DBG("chan %p", chan);
1211
1212 if (chan->mode != L2CAP_MODE_ERTM)
1213 return;
1214
1215 __clear_retrans_timer(chan);
1216 __clear_monitor_timer(chan);
1217 __clear_ack_timer(chan);
1218
1219 chan->retry_count = 0;
1220 skb_queue_walk(&chan->tx_q, skb) {
1221 if (bt_cb(skb)->l2cap.retries)
1222 bt_cb(skb)->l2cap.retries = 1;
1223 else
1224 break;
1225 }
1226
1227 chan->expected_tx_seq = chan->buffer_seq;
1228
1229 clear_bit(CONN_REJ_ACT, &chan->conn_state);
1230 clear_bit(CONN_SREJ_ACT, &chan->conn_state);
1231 l2cap_seq_list_clear(&chan->retrans_list);
1232 l2cap_seq_list_clear(&chan->srej_list);
1233 skb_queue_purge(&chan->srej_q);
1234
1235 chan->tx_state = L2CAP_TX_STATE_XMIT;
1236 chan->rx_state = L2CAP_RX_STATE_MOVE;
1237
1238 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
1239}
1240
1241static void l2cap_move_done(struct l2cap_chan *chan)
1242{
1243 u8 move_role = chan->move_role;
1244 BT_DBG("chan %p", chan);
1245
1246 chan->move_state = L2CAP_MOVE_STABLE;
1247 chan->move_role = L2CAP_MOVE_ROLE_NONE;
1248
1249 if (chan->mode != L2CAP_MODE_ERTM)
1250 return;
1251
1252 switch (move_role) {
1253 case L2CAP_MOVE_ROLE_INITIATOR:
1254 l2cap_tx(chan, NULL, NULL, L2CAP_EV_EXPLICIT_POLL);
1255 chan->rx_state = L2CAP_RX_STATE_WAIT_F;
1256 break;
1257 case L2CAP_MOVE_ROLE_RESPONDER:
1258 chan->rx_state = L2CAP_RX_STATE_WAIT_P;
1259 break;
1260 }
1261}
1262
1263static void l2cap_chan_ready(struct l2cap_chan *chan)
1264{
1265 /* The channel may have already been flagged as connected in
1266 * case of receiving data before the L2CAP info req/rsp
1267 * procedure is complete.
1268 */
1269 if (chan->state == BT_CONNECTED)
1270 return;
1271
1272 /* This clears all conf flags, including CONF_NOT_COMPLETE */
1273 chan->conf_state = 0;
1274 __clear_chan_timer(chan);
1275
1276 if (chan->mode == L2CAP_MODE_LE_FLOWCTL && !chan->tx_credits)
1277 chan->ops->suspend(chan);
1278
1279 chan->state = BT_CONNECTED;
1280
1281 chan->ops->ready(chan);
1282}
1283
1284static void l2cap_le_connect(struct l2cap_chan *chan)
1285{
1286 struct l2cap_conn *conn = chan->conn;
1287 struct l2cap_le_conn_req req;
1288
1289 if (test_and_set_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags))
1290 return;
1291
1292 l2cap_le_flowctl_init(chan, 0);
1293
1294 req.psm = chan->psm;
1295 req.scid = cpu_to_le16(chan->scid);
1296 req.mtu = cpu_to_le16(chan->imtu);
1297 req.mps = cpu_to_le16(chan->mps);
1298 req.credits = cpu_to_le16(chan->rx_credits);
1299
1300 chan->ident = l2cap_get_ident(conn);
1301
1302 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_REQ,
1303 sizeof(req), &req);
1304}
1305
1306static void l2cap_le_start(struct l2cap_chan *chan)
1307{
1308 struct l2cap_conn *conn = chan->conn;
1309
1310 if (!smp_conn_security(conn->hcon, chan->sec_level))
1311 return;
1312
1313 if (!chan->psm) {
1314 l2cap_chan_ready(chan);
1315 return;
1316 }
1317
1318 if (chan->state == BT_CONNECT)
1319 l2cap_le_connect(chan);
1320}
1321
1322static void l2cap_start_connection(struct l2cap_chan *chan)
1323{
1324 if (__amp_capable(chan)) {
1325 BT_DBG("chan %p AMP capable: discover AMPs", chan);
1326 a2mp_discover_amp(chan);
1327 } else if (chan->conn->hcon->type == LE_LINK) {
1328 l2cap_le_start(chan);
1329 } else {
1330 l2cap_send_conn_req(chan);
1331 }
1332}
1333
1334static void l2cap_request_info(struct l2cap_conn *conn)
1335{
1336 struct l2cap_info_req req;
1337
1338 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1339 return;
1340
1341 req.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
1342
1343 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
1344 conn->info_ident = l2cap_get_ident(conn);
1345
1346 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
1347
1348 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
1349 sizeof(req), &req);
1350}
1351
1352static bool l2cap_check_enc_key_size(struct hci_conn *hcon)
1353{
1354 /* The minimum encryption key size needs to be enforced by the
1355 * host stack before establishing any L2CAP connections. The
1356 * specification in theory allows a minimum of 1, but to align
1357 * BR/EDR and LE transports, a minimum of 7 is chosen.
1358 *
1359 * This check might also be called for unencrypted connections
1360 * that have no key size requirements. Ensure that the link is
1361 * actually encrypted before enforcing a key size.
1362 */
1363 return (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags) ||
1364 hcon->enc_key_size >= hcon->hdev->min_enc_key_size);
1365}
1366
1367static void l2cap_do_start(struct l2cap_chan *chan)
1368{
1369 struct l2cap_conn *conn = chan->conn;
1370
1371 if (conn->hcon->type == LE_LINK) {
1372 l2cap_le_start(chan);
1373 return;
1374 }
1375
1376 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)) {
1377 l2cap_request_info(conn);
1378 return;
1379 }
1380
1381 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE))
1382 return;
1383
1384 if (!l2cap_chan_check_security(chan, true) ||
1385 !__l2cap_no_conn_pending(chan))
1386 return;
1387
1388 if (l2cap_check_enc_key_size(conn->hcon))
1389 l2cap_start_connection(chan);
1390 else
1391 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
1392}
1393
1394static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
1395{
1396 u32 local_feat_mask = l2cap_feat_mask;
1397 if (!disable_ertm)
1398 local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
1399
1400 switch (mode) {
1401 case L2CAP_MODE_ERTM:
1402 return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
1403 case L2CAP_MODE_STREAMING:
1404 return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
1405 default:
1406 return 0x00;
1407 }
1408}
1409
1410static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err)
1411{
1412 struct l2cap_conn *conn = chan->conn;
1413 struct l2cap_disconn_req req;
1414
1415 if (!conn)
1416 return;
1417
1418 if (chan->mode == L2CAP_MODE_ERTM && chan->state == BT_CONNECTED) {
1419 __clear_retrans_timer(chan);
1420 __clear_monitor_timer(chan);
1421 __clear_ack_timer(chan);
1422 }
1423
1424 if (chan->scid == L2CAP_CID_A2MP) {
1425 l2cap_state_change(chan, BT_DISCONN);
1426 return;
1427 }
1428
1429 req.dcid = cpu_to_le16(chan->dcid);
1430 req.scid = cpu_to_le16(chan->scid);
1431 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_DISCONN_REQ,
1432 sizeof(req), &req);
1433
1434 l2cap_state_change_and_error(chan, BT_DISCONN, err);
1435}
1436
1437/* ---- L2CAP connections ---- */
1438static void l2cap_conn_start(struct l2cap_conn *conn)
1439{
1440 struct l2cap_chan *chan, *tmp;
1441
1442 BT_DBG("conn %p", conn);
1443
1444 mutex_lock(&conn->chan_lock);
1445
1446 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
1447 l2cap_chan_lock(chan);
1448
1449 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1450 l2cap_chan_ready(chan);
1451 l2cap_chan_unlock(chan);
1452 continue;
1453 }
1454
1455 if (chan->state == BT_CONNECT) {
1456 if (!l2cap_chan_check_security(chan, true) ||
1457 !__l2cap_no_conn_pending(chan)) {
1458 l2cap_chan_unlock(chan);
1459 continue;
1460 }
1461
1462 if (!l2cap_mode_supported(chan->mode, conn->feat_mask)
1463 && test_bit(CONF_STATE2_DEVICE,
1464 &chan->conf_state)) {
1465 l2cap_chan_close(chan, ECONNRESET);
1466 l2cap_chan_unlock(chan);
1467 continue;
1468 }
1469
1470 if (l2cap_check_enc_key_size(conn->hcon))
1471 l2cap_start_connection(chan);
1472 else
1473 l2cap_chan_close(chan, ECONNREFUSED);
1474
1475 } else if (chan->state == BT_CONNECT2) {
1476 struct l2cap_conn_rsp rsp;
1477 char buf[128];
1478 rsp.scid = cpu_to_le16(chan->dcid);
1479 rsp.dcid = cpu_to_le16(chan->scid);
1480
1481 if (l2cap_chan_check_security(chan, false)) {
1482 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
1483 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1484 rsp.status = cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
1485 chan->ops->defer(chan);
1486
1487 } else {
1488 l2cap_state_change(chan, BT_CONFIG);
1489 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
1490 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
1491 }
1492 } else {
1493 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1494 rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
1495 }
1496
1497 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
1498 sizeof(rsp), &rsp);
1499
1500 if (test_bit(CONF_REQ_SENT, &chan->conf_state) ||
1501 rsp.result != L2CAP_CR_SUCCESS) {
1502 l2cap_chan_unlock(chan);
1503 continue;
1504 }
1505
1506 set_bit(CONF_REQ_SENT, &chan->conf_state);
1507 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
1508 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
1509 chan->num_conf_req++;
1510 }
1511
1512 l2cap_chan_unlock(chan);
1513 }
1514
1515 mutex_unlock(&conn->chan_lock);
1516}
1517
1518static void l2cap_le_conn_ready(struct l2cap_conn *conn)
1519{
1520 struct hci_conn *hcon = conn->hcon;
1521 struct hci_dev *hdev = hcon->hdev;
1522
1523 BT_DBG("%s conn %p", hdev->name, conn);
1524
1525 /* For outgoing pairing which doesn't necessarily have an
1526 * associated socket (e.g. mgmt_pair_device).
1527 */
1528 if (hcon->out)
1529 smp_conn_security(hcon, hcon->pending_sec_level);
1530
1531 /* For LE slave connections, make sure the connection interval
1532 * is in the range of the minium and maximum interval that has
1533 * been configured for this connection. If not, then trigger
1534 * the connection update procedure.
1535 */
1536 if (hcon->role == HCI_ROLE_SLAVE &&
1537 (hcon->le_conn_interval < hcon->le_conn_min_interval ||
1538 hcon->le_conn_interval > hcon->le_conn_max_interval)) {
1539 struct l2cap_conn_param_update_req req;
1540
1541 req.min = cpu_to_le16(hcon->le_conn_min_interval);
1542 req.max = cpu_to_le16(hcon->le_conn_max_interval);
1543 req.latency = cpu_to_le16(hcon->le_conn_latency);
1544 req.to_multiplier = cpu_to_le16(hcon->le_supv_timeout);
1545
1546 l2cap_send_cmd(conn, l2cap_get_ident(conn),
1547 L2CAP_CONN_PARAM_UPDATE_REQ, sizeof(req), &req);
1548 }
1549}
1550
1551static void l2cap_conn_ready(struct l2cap_conn *conn)
1552{
1553 struct l2cap_chan *chan;
1554 struct hci_conn *hcon = conn->hcon;
1555
1556 BT_DBG("conn %p", conn);
1557
1558 if (hcon->type == ACL_LINK)
1559 l2cap_request_info(conn);
1560
1561 mutex_lock(&conn->chan_lock);
1562
1563 list_for_each_entry(chan, &conn->chan_l, list) {
1564
1565 l2cap_chan_lock(chan);
1566
1567 if (chan->scid == L2CAP_CID_A2MP) {
1568 l2cap_chan_unlock(chan);
1569 continue;
1570 }
1571
1572 if (hcon->type == LE_LINK) {
1573 l2cap_le_start(chan);
1574 } else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1575 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
1576 l2cap_chan_ready(chan);
1577 } else if (chan->state == BT_CONNECT) {
1578 l2cap_do_start(chan);
1579 }
1580
1581 l2cap_chan_unlock(chan);
1582 }
1583
1584 mutex_unlock(&conn->chan_lock);
1585
1586 if (hcon->type == LE_LINK)
1587 l2cap_le_conn_ready(conn);
1588
1589 queue_work(hcon->hdev->workqueue, &conn->pending_rx_work);
1590}
1591
1592/* Notify sockets that we cannot guaranty reliability anymore */
1593static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
1594{
1595 struct l2cap_chan *chan;
1596
1597 BT_DBG("conn %p", conn);
1598
1599 mutex_lock(&conn->chan_lock);
1600
1601 list_for_each_entry(chan, &conn->chan_l, list) {
1602 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
1603 l2cap_chan_set_err(chan, err);
1604 }
1605
1606 mutex_unlock(&conn->chan_lock);
1607}
1608
1609static void l2cap_info_timeout(struct work_struct *work)
1610{
1611 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
1612 info_timer.work);
1613
1614 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
1615 conn->info_ident = 0;
1616
1617 l2cap_conn_start(conn);
1618}
1619
1620/*
1621 * l2cap_user
1622 * External modules can register l2cap_user objects on l2cap_conn. The ->probe
1623 * callback is called during registration. The ->remove callback is called
1624 * during unregistration.
1625 * An l2cap_user object can either be explicitly unregistered or when the
1626 * underlying l2cap_conn object is deleted. This guarantees that l2cap->hcon,
1627 * l2cap->hchan, .. are valid as long as the remove callback hasn't been called.
1628 * External modules must own a reference to the l2cap_conn object if they intend
1629 * to call l2cap_unregister_user(). The l2cap_conn object might get destroyed at
1630 * any time if they don't.
1631 */
1632
1633int l2cap_register_user(struct l2cap_conn *conn, struct l2cap_user *user)
1634{
1635 struct hci_dev *hdev = conn->hcon->hdev;
1636 int ret;
1637
1638 /* We need to check whether l2cap_conn is registered. If it is not, we
1639 * must not register the l2cap_user. l2cap_conn_del() is unregisters
1640 * l2cap_conn objects, but doesn't provide its own locking. Instead, it
1641 * relies on the parent hci_conn object to be locked. This itself relies
1642 * on the hci_dev object to be locked. So we must lock the hci device
1643 * here, too. */
1644
1645 hci_dev_lock(hdev);
1646
1647 if (!list_empty(&user->list)) {
1648 ret = -EINVAL;
1649 goto out_unlock;
1650 }
1651
1652 /* conn->hchan is NULL after l2cap_conn_del() was called */
1653 if (!conn->hchan) {
1654 ret = -ENODEV;
1655 goto out_unlock;
1656 }
1657
1658 ret = user->probe(conn, user);
1659 if (ret)
1660 goto out_unlock;
1661
1662 list_add(&user->list, &conn->users);
1663 ret = 0;
1664
1665out_unlock:
1666 hci_dev_unlock(hdev);
1667 return ret;
1668}
1669EXPORT_SYMBOL(l2cap_register_user);
1670
1671void l2cap_unregister_user(struct l2cap_conn *conn, struct l2cap_user *user)
1672{
1673 struct hci_dev *hdev = conn->hcon->hdev;
1674
1675 hci_dev_lock(hdev);
1676
1677 if (list_empty(&user->list))
1678 goto out_unlock;
1679
1680 list_del_init(&user->list);
1681 user->remove(conn, user);
1682
1683out_unlock:
1684 hci_dev_unlock(hdev);
1685}
1686EXPORT_SYMBOL(l2cap_unregister_user);
1687
1688static void l2cap_unregister_all_users(struct l2cap_conn *conn)
1689{
1690 struct l2cap_user *user;
1691
1692 while (!list_empty(&conn->users)) {
1693 user = list_first_entry(&conn->users, struct l2cap_user, list);
1694 list_del_init(&user->list);
1695 user->remove(conn, user);
1696 }
1697}
1698
1699static void l2cap_conn_del(struct hci_conn *hcon, int err)
1700{
1701 struct l2cap_conn *conn = hcon->l2cap_data;
1702 struct l2cap_chan *chan, *l;
1703
1704 if (!conn)
1705 return;
1706
1707 BT_DBG("hcon %p conn %p, err %d", hcon, conn, err);
1708
1709 kfree_skb(conn->rx_skb);
1710
1711 skb_queue_purge(&conn->pending_rx);
1712
1713 /* We can not call flush_work(&conn->pending_rx_work) here since we
1714 * might block if we are running on a worker from the same workqueue
1715 * pending_rx_work is waiting on.
1716 */
1717 if (work_pending(&conn->pending_rx_work))
1718 cancel_work_sync(&conn->pending_rx_work);
1719
1720 if (work_pending(&conn->id_addr_update_work))
1721 cancel_work_sync(&conn->id_addr_update_work);
1722
1723 l2cap_unregister_all_users(conn);
1724
1725 /* Force the connection to be immediately dropped */
1726 hcon->disc_timeout = 0;
1727
1728 mutex_lock(&conn->chan_lock);
1729
1730 /* Kill channels */
1731 list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
1732 l2cap_chan_hold(chan);
1733 l2cap_chan_lock(chan);
1734
1735 l2cap_chan_del(chan, err);
1736
1737 l2cap_chan_unlock(chan);
1738
1739 chan->ops->close(chan);
1740 l2cap_chan_put(chan);
1741 }
1742
1743 mutex_unlock(&conn->chan_lock);
1744
1745 hci_chan_del(conn->hchan);
1746
1747 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1748 cancel_delayed_work_sync(&conn->info_timer);
1749
1750 hcon->l2cap_data = NULL;
1751 conn->hchan = NULL;
1752 l2cap_conn_put(conn);
1753}
1754
1755static void l2cap_conn_free(struct kref *ref)
1756{
1757 struct l2cap_conn *conn = container_of(ref, struct l2cap_conn, ref);
1758
1759 hci_conn_put(conn->hcon);
1760 kfree(conn);
1761}
1762
1763struct l2cap_conn *l2cap_conn_get(struct l2cap_conn *conn)
1764{
1765 kref_get(&conn->ref);
1766 return conn;
1767}
1768EXPORT_SYMBOL(l2cap_conn_get);
1769
1770void l2cap_conn_put(struct l2cap_conn *conn)
1771{
1772 kref_put(&conn->ref, l2cap_conn_free);
1773}
1774EXPORT_SYMBOL(l2cap_conn_put);
1775
1776/* ---- Socket interface ---- */
1777
1778/* Find socket with psm and source / destination bdaddr.
1779 * Returns closest match.
1780 */
1781static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
1782 bdaddr_t *src,
1783 bdaddr_t *dst,
1784 u8 link_type)
1785{
1786 struct l2cap_chan *c, *c1 = NULL;
1787
1788 read_lock(&chan_list_lock);
1789
1790 list_for_each_entry(c, &chan_list, global_l) {
1791 if (state && c->state != state)
1792 continue;
1793
1794 if (link_type == ACL_LINK && c->src_type != BDADDR_BREDR)
1795 continue;
1796
1797 if (link_type == LE_LINK && c->src_type == BDADDR_BREDR)
1798 continue;
1799
1800 if (c->psm == psm) {
1801 int src_match, dst_match;
1802 int src_any, dst_any;
1803
1804 /* Exact match. */
1805 src_match = !bacmp(&c->src, src);
1806 dst_match = !bacmp(&c->dst, dst);
1807 if (src_match && dst_match) {
1808 l2cap_chan_hold(c);
1809 read_unlock(&chan_list_lock);
1810 return c;
1811 }
1812
1813 /* Closest match */
1814 src_any = !bacmp(&c->src, BDADDR_ANY);
1815 dst_any = !bacmp(&c->dst, BDADDR_ANY);
1816 if ((src_match && dst_any) || (src_any && dst_match) ||
1817 (src_any && dst_any))
1818 c1 = c;
1819 }
1820 }
1821
1822 if (c1)
1823 l2cap_chan_hold(c1);
1824
1825 read_unlock(&chan_list_lock);
1826
1827 return c1;
1828}
1829
1830static void l2cap_monitor_timeout(struct work_struct *work)
1831{
1832 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
1833 monitor_timer.work);
1834
1835 BT_DBG("chan %p", chan);
1836
1837 l2cap_chan_lock(chan);
1838
1839 if (!chan->conn) {
1840 l2cap_chan_unlock(chan);
1841 l2cap_chan_put(chan);
1842 return;
1843 }
1844
1845 l2cap_tx(chan, NULL, NULL, L2CAP_EV_MONITOR_TO);
1846
1847 l2cap_chan_unlock(chan);
1848 l2cap_chan_put(chan);
1849}
1850
1851static void l2cap_retrans_timeout(struct work_struct *work)
1852{
1853 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
1854 retrans_timer.work);
1855
1856 BT_DBG("chan %p", chan);
1857
1858 l2cap_chan_lock(chan);
1859
1860 if (!chan->conn) {
1861 l2cap_chan_unlock(chan);
1862 l2cap_chan_put(chan);
1863 return;
1864 }
1865
1866 l2cap_tx(chan, NULL, NULL, L2CAP_EV_RETRANS_TO);
1867 l2cap_chan_unlock(chan);
1868 l2cap_chan_put(chan);
1869}
1870
1871static void l2cap_streaming_send(struct l2cap_chan *chan,
1872 struct sk_buff_head *skbs)
1873{
1874 struct sk_buff *skb;
1875 struct l2cap_ctrl *control;
1876
1877 BT_DBG("chan %p, skbs %p", chan, skbs);
1878
1879 if (__chan_is_moving(chan))
1880 return;
1881
1882 skb_queue_splice_tail_init(skbs, &chan->tx_q);
1883
1884 while (!skb_queue_empty(&chan->tx_q)) {
1885
1886 skb = skb_dequeue(&chan->tx_q);
1887
1888 bt_cb(skb)->l2cap.retries = 1;
1889 control = &bt_cb(skb)->l2cap;
1890
1891 control->reqseq = 0;
1892 control->txseq = chan->next_tx_seq;
1893
1894 __pack_control(chan, control, skb);
1895
1896 if (chan->fcs == L2CAP_FCS_CRC16) {
1897 u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
1898 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1899 }
1900
1901 l2cap_do_send(chan, skb);
1902
1903 BT_DBG("Sent txseq %u", control->txseq);
1904
1905 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
1906 chan->frames_sent++;
1907 }
1908}
1909
1910static int l2cap_ertm_send(struct l2cap_chan *chan)
1911{
1912 struct sk_buff *skb, *tx_skb;
1913 struct l2cap_ctrl *control;
1914 int sent = 0;
1915
1916 BT_DBG("chan %p", chan);
1917
1918 if (chan->state != BT_CONNECTED)
1919 return -ENOTCONN;
1920
1921 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
1922 return 0;
1923
1924 if (__chan_is_moving(chan))
1925 return 0;
1926
1927 while (chan->tx_send_head &&
1928 chan->unacked_frames < chan->remote_tx_win &&
1929 chan->tx_state == L2CAP_TX_STATE_XMIT) {
1930
1931 skb = chan->tx_send_head;
1932
1933 bt_cb(skb)->l2cap.retries = 1;
1934 control = &bt_cb(skb)->l2cap;
1935
1936 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
1937 control->final = 1;
1938
1939 control->reqseq = chan->buffer_seq;
1940 chan->last_acked_seq = chan->buffer_seq;
1941 control->txseq = chan->next_tx_seq;
1942
1943 __pack_control(chan, control, skb);
1944
1945 if (chan->fcs == L2CAP_FCS_CRC16) {
1946 u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
1947 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1948 }
1949
1950 /* Clone after data has been modified. Data is assumed to be
1951 read-only (for locking purposes) on cloned sk_buffs.
1952 */
1953 tx_skb = skb_clone(skb, GFP_KERNEL);
1954
1955 if (!tx_skb)
1956 break;
1957
1958 __set_retrans_timer(chan);
1959
1960 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
1961 chan->unacked_frames++;
1962 chan->frames_sent++;
1963 sent++;
1964
1965 if (skb_queue_is_last(&chan->tx_q, skb))
1966 chan->tx_send_head = NULL;
1967 else
1968 chan->tx_send_head = skb_queue_next(&chan->tx_q, skb);
1969
1970 l2cap_do_send(chan, tx_skb);
1971 BT_DBG("Sent txseq %u", control->txseq);
1972 }
1973
1974 BT_DBG("Sent %d, %u unacked, %u in ERTM queue", sent,
1975 chan->unacked_frames, skb_queue_len(&chan->tx_q));
1976
1977 return sent;
1978}
1979
1980static void l2cap_ertm_resend(struct l2cap_chan *chan)
1981{
1982 struct l2cap_ctrl control;
1983 struct sk_buff *skb;
1984 struct sk_buff *tx_skb;
1985 u16 seq;
1986
1987 BT_DBG("chan %p", chan);
1988
1989 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
1990 return;
1991
1992 if (__chan_is_moving(chan))
1993 return;
1994
1995 while (chan->retrans_list.head != L2CAP_SEQ_LIST_CLEAR) {
1996 seq = l2cap_seq_list_pop(&chan->retrans_list);
1997
1998 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, seq);
1999 if (!skb) {
2000 BT_DBG("Error: Can't retransmit seq %d, frame missing",
2001 seq);
2002 continue;
2003 }
2004
2005 bt_cb(skb)->l2cap.retries++;
2006 control = bt_cb(skb)->l2cap;
2007
2008 if (chan->max_tx != 0 &&
2009 bt_cb(skb)->l2cap.retries > chan->max_tx) {
2010 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
2011 l2cap_send_disconn_req(chan, ECONNRESET);
2012 l2cap_seq_list_clear(&chan->retrans_list);
2013 break;
2014 }
2015
2016 control.reqseq = chan->buffer_seq;
2017 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
2018 control.final = 1;
2019 else
2020 control.final = 0;
2021
2022 if (skb_cloned(skb)) {
2023 /* Cloned sk_buffs are read-only, so we need a
2024 * writeable copy
2025 */
2026 tx_skb = skb_copy(skb, GFP_KERNEL);
2027 } else {
2028 tx_skb = skb_clone(skb, GFP_KERNEL);
2029 }
2030
2031 if (!tx_skb) {
2032 l2cap_seq_list_clear(&chan->retrans_list);
2033 break;
2034 }
2035
2036 /* Update skb contents */
2037 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
2038 put_unaligned_le32(__pack_extended_control(&control),
2039 tx_skb->data + L2CAP_HDR_SIZE);
2040 } else {
2041 put_unaligned_le16(__pack_enhanced_control(&control),
2042 tx_skb->data + L2CAP_HDR_SIZE);
2043 }
2044
2045 /* Update FCS */
2046 if (chan->fcs == L2CAP_FCS_CRC16) {
2047 u16 fcs = crc16(0, (u8 *) tx_skb->data,
2048 tx_skb->len - L2CAP_FCS_SIZE);
2049 put_unaligned_le16(fcs, skb_tail_pointer(tx_skb) -
2050 L2CAP_FCS_SIZE);
2051 }
2052
2053 l2cap_do_send(chan, tx_skb);
2054
2055 BT_DBG("Resent txseq %d", control.txseq);
2056
2057 chan->last_acked_seq = chan->buffer_seq;
2058 }
2059}
2060
2061static void l2cap_retransmit(struct l2cap_chan *chan,
2062 struct l2cap_ctrl *control)
2063{
2064 BT_DBG("chan %p, control %p", chan, control);
2065
2066 l2cap_seq_list_append(&chan->retrans_list, control->reqseq);
2067 l2cap_ertm_resend(chan);
2068}
2069
2070static void l2cap_retransmit_all(struct l2cap_chan *chan,
2071 struct l2cap_ctrl *control)
2072{
2073 struct sk_buff *skb;
2074
2075 BT_DBG("chan %p, control %p", chan, control);
2076
2077 if (control->poll)
2078 set_bit(CONN_SEND_FBIT, &chan->conn_state);
2079
2080 l2cap_seq_list_clear(&chan->retrans_list);
2081
2082 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
2083 return;
2084
2085 if (chan->unacked_frames) {
2086 skb_queue_walk(&chan->tx_q, skb) {
2087 if (bt_cb(skb)->l2cap.txseq == control->reqseq ||
2088 skb == chan->tx_send_head)
2089 break;
2090 }
2091
2092 skb_queue_walk_from(&chan->tx_q, skb) {
2093 if (skb == chan->tx_send_head)
2094 break;
2095
2096 l2cap_seq_list_append(&chan->retrans_list,
2097 bt_cb(skb)->l2cap.txseq);
2098 }
2099
2100 l2cap_ertm_resend(chan);
2101 }
2102}
2103
2104static void l2cap_send_ack(struct l2cap_chan *chan)
2105{
2106 struct l2cap_ctrl control;
2107 u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
2108 chan->last_acked_seq);
2109 int threshold;
2110
2111 BT_DBG("chan %p last_acked_seq %d buffer_seq %d",
2112 chan, chan->last_acked_seq, chan->buffer_seq);
2113
2114 memset(&control, 0, sizeof(control));
2115 control.sframe = 1;
2116
2117 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
2118 chan->rx_state == L2CAP_RX_STATE_RECV) {
2119 __clear_ack_timer(chan);
2120 control.super = L2CAP_SUPER_RNR;
2121 control.reqseq = chan->buffer_seq;
2122 l2cap_send_sframe(chan, &control);
2123 } else {
2124 if (!test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) {
2125 l2cap_ertm_send(chan);
2126 /* If any i-frames were sent, they included an ack */
2127 if (chan->buffer_seq == chan->last_acked_seq)
2128 frames_to_ack = 0;
2129 }
2130
2131 /* Ack now if the window is 3/4ths full.
2132 * Calculate without mul or div
2133 */
2134 threshold = chan->ack_win;
2135 threshold += threshold << 1;
2136 threshold >>= 2;
2137
2138 BT_DBG("frames_to_ack %u, threshold %d", frames_to_ack,
2139 threshold);
2140
2141 if (frames_to_ack >= threshold) {
2142 __clear_ack_timer(chan);
2143 control.super = L2CAP_SUPER_RR;
2144 control.reqseq = chan->buffer_seq;
2145 l2cap_send_sframe(chan, &control);
2146 frames_to_ack = 0;
2147 }
2148
2149 if (frames_to_ack)
2150 __set_ack_timer(chan);
2151 }
2152}
2153
2154static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
2155 struct msghdr *msg, int len,
2156 int count, struct sk_buff *skb)
2157{
2158 struct l2cap_conn *conn = chan->conn;
2159 struct sk_buff **frag;
2160 int sent = 0;
2161
2162 if (!copy_from_iter_full(skb_put(skb, count), count, &msg->msg_iter))
2163 return -EFAULT;
2164
2165 sent += count;
2166 len -= count;
2167
2168 /* Continuation fragments (no L2CAP header) */
2169 frag = &skb_shinfo(skb)->frag_list;
2170 while (len) {
2171 struct sk_buff *tmp;
2172
2173 count = min_t(unsigned int, conn->mtu, len);
2174
2175 tmp = chan->ops->alloc_skb(chan, 0, count,
2176 msg->msg_flags & MSG_DONTWAIT);
2177 if (IS_ERR(tmp))
2178 return PTR_ERR(tmp);
2179
2180 *frag = tmp;
2181
2182 if (!copy_from_iter_full(skb_put(*frag, count), count,
2183 &msg->msg_iter))
2184 return -EFAULT;
2185
2186 sent += count;
2187 len -= count;
2188
2189 skb->len += (*frag)->len;
2190 skb->data_len += (*frag)->len;
2191
2192 frag = &(*frag)->next;
2193 }
2194
2195 return sent;
2196}
2197
2198static struct sk_buff *l2cap_create_connless_pdu(struct l2cap_chan *chan,
2199 struct msghdr *msg, size_t len)
2200{
2201 struct l2cap_conn *conn = chan->conn;
2202 struct sk_buff *skb;
2203 int err, count, hlen = L2CAP_HDR_SIZE + L2CAP_PSMLEN_SIZE;
2204 struct l2cap_hdr *lh;
2205
2206 BT_DBG("chan %p psm 0x%2.2x len %zu", chan,
2207 __le16_to_cpu(chan->psm), len);
2208
2209 count = min_t(unsigned int, (conn->mtu - hlen), len);
2210
2211 skb = chan->ops->alloc_skb(chan, hlen, 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 + L2CAP_PSMLEN_SIZE);
2220 put_unaligned(chan->psm, (__le16 *) skb_put(skb, L2CAP_PSMLEN_SIZE));
2221
2222 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2223 if (unlikely(err < 0)) {
2224 kfree_skb(skb);
2225 return ERR_PTR(err);
2226 }
2227 return skb;
2228}
2229
2230static struct sk_buff *l2cap_create_basic_pdu(struct l2cap_chan *chan,
2231 struct msghdr *msg, size_t len)
2232{
2233 struct l2cap_conn *conn = chan->conn;
2234 struct sk_buff *skb;
2235 int err, count;
2236 struct l2cap_hdr *lh;
2237
2238 BT_DBG("chan %p len %zu", chan, len);
2239
2240 count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len);
2241
2242 skb = chan->ops->alloc_skb(chan, L2CAP_HDR_SIZE, count,
2243 msg->msg_flags & MSG_DONTWAIT);
2244 if (IS_ERR(skb))
2245 return skb;
2246
2247 /* Create L2CAP header */
2248 lh = skb_put(skb, L2CAP_HDR_SIZE);
2249 lh->cid = cpu_to_le16(chan->dcid);
2250 lh->len = cpu_to_le16(len);
2251
2252 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2253 if (unlikely(err < 0)) {
2254 kfree_skb(skb);
2255 return ERR_PTR(err);
2256 }
2257 return skb;
2258}
2259
2260static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan,
2261 struct msghdr *msg, size_t len,
2262 u16 sdulen)
2263{
2264 struct l2cap_conn *conn = chan->conn;
2265 struct sk_buff *skb;
2266 int err, count, hlen;
2267 struct l2cap_hdr *lh;
2268
2269 BT_DBG("chan %p len %zu", chan, len);
2270
2271 if (!conn)
2272 return ERR_PTR(-ENOTCONN);
2273
2274 hlen = __ertm_hdr_size(chan);
2275
2276 if (sdulen)
2277 hlen += L2CAP_SDULEN_SIZE;
2278
2279 if (chan->fcs == L2CAP_FCS_CRC16)
2280 hlen += L2CAP_FCS_SIZE;
2281
2282 count = min_t(unsigned int, (conn->mtu - hlen), len);
2283
2284 skb = chan->ops->alloc_skb(chan, hlen, count,
2285 msg->msg_flags & MSG_DONTWAIT);
2286 if (IS_ERR(skb))
2287 return skb;
2288
2289 /* Create L2CAP header */
2290 lh = skb_put(skb, L2CAP_HDR_SIZE);
2291 lh->cid = cpu_to_le16(chan->dcid);
2292 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2293
2294 /* Control header is populated later */
2295 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
2296 put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
2297 else
2298 put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
2299
2300 if (sdulen)
2301 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2302
2303 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2304 if (unlikely(err < 0)) {
2305 kfree_skb(skb);
2306 return ERR_PTR(err);
2307 }
2308
2309 bt_cb(skb)->l2cap.fcs = chan->fcs;
2310 bt_cb(skb)->l2cap.retries = 0;
2311 return skb;
2312}
2313
2314static int l2cap_segment_sdu(struct l2cap_chan *chan,
2315 struct sk_buff_head *seg_queue,
2316 struct msghdr *msg, size_t len)
2317{
2318 struct sk_buff *skb;
2319 u16 sdu_len;
2320 size_t pdu_len;
2321 u8 sar;
2322
2323 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2324
2325 /* It is critical that ERTM PDUs fit in a single HCI fragment,
2326 * so fragmented skbs are not used. The HCI layer's handling
2327 * of fragmented skbs is not compatible with ERTM's queueing.
2328 */
2329
2330 /* PDU size is derived from the HCI MTU */
2331 pdu_len = chan->conn->mtu;
2332
2333 /* Constrain PDU size for BR/EDR connections */
2334 if (!chan->hs_hcon)
2335 pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD);
2336
2337 /* Adjust for largest possible L2CAP overhead. */
2338 if (chan->fcs)
2339 pdu_len -= L2CAP_FCS_SIZE;
2340
2341 pdu_len -= __ertm_hdr_size(chan);
2342
2343 /* Remote device may have requested smaller PDUs */
2344 pdu_len = min_t(size_t, pdu_len, chan->remote_mps);
2345
2346 if (len <= pdu_len) {
2347 sar = L2CAP_SAR_UNSEGMENTED;
2348 sdu_len = 0;
2349 pdu_len = len;
2350 } else {
2351 sar = L2CAP_SAR_START;
2352 sdu_len = len;
2353 }
2354
2355 while (len > 0) {
2356 skb = l2cap_create_iframe_pdu(chan, msg, pdu_len, sdu_len);
2357
2358 if (IS_ERR(skb)) {
2359 __skb_queue_purge(seg_queue);
2360 return PTR_ERR(skb);
2361 }
2362
2363 bt_cb(skb)->l2cap.sar = sar;
2364 __skb_queue_tail(seg_queue, skb);
2365
2366 len -= pdu_len;
2367 if (sdu_len)
2368 sdu_len = 0;
2369
2370 if (len <= pdu_len) {
2371 sar = L2CAP_SAR_END;
2372 pdu_len = len;
2373 } else {
2374 sar = L2CAP_SAR_CONTINUE;
2375 }
2376 }
2377
2378 return 0;
2379}
2380
2381static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan,
2382 struct msghdr *msg,
2383 size_t len, u16 sdulen)
2384{
2385 struct l2cap_conn *conn = chan->conn;
2386 struct sk_buff *skb;
2387 int err, count, hlen;
2388 struct l2cap_hdr *lh;
2389
2390 BT_DBG("chan %p len %zu", chan, len);
2391
2392 if (!conn)
2393 return ERR_PTR(-ENOTCONN);
2394
2395 hlen = L2CAP_HDR_SIZE;
2396
2397 if (sdulen)
2398 hlen += L2CAP_SDULEN_SIZE;
2399
2400 count = min_t(unsigned int, (conn->mtu - hlen), len);
2401
2402 skb = chan->ops->alloc_skb(chan, hlen, count,
2403 msg->msg_flags & MSG_DONTWAIT);
2404 if (IS_ERR(skb))
2405 return skb;
2406
2407 /* Create L2CAP header */
2408 lh = skb_put(skb, L2CAP_HDR_SIZE);
2409 lh->cid = cpu_to_le16(chan->dcid);
2410 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2411
2412 if (sdulen)
2413 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2414
2415 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2416 if (unlikely(err < 0)) {
2417 kfree_skb(skb);
2418 return ERR_PTR(err);
2419 }
2420
2421 return skb;
2422}
2423
2424static int l2cap_segment_le_sdu(struct l2cap_chan *chan,
2425 struct sk_buff_head *seg_queue,
2426 struct msghdr *msg, size_t len)
2427{
2428 struct sk_buff *skb;
2429 size_t pdu_len;
2430 u16 sdu_len;
2431
2432 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2433
2434 sdu_len = len;
2435 pdu_len = chan->remote_mps - L2CAP_SDULEN_SIZE;
2436
2437 while (len > 0) {
2438 if (len <= pdu_len)
2439 pdu_len = len;
2440
2441 skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len);
2442 if (IS_ERR(skb)) {
2443 __skb_queue_purge(seg_queue);
2444 return PTR_ERR(skb);
2445 }
2446
2447 __skb_queue_tail(seg_queue, skb);
2448
2449 len -= pdu_len;
2450
2451 if (sdu_len) {
2452 sdu_len = 0;
2453 pdu_len += L2CAP_SDULEN_SIZE;
2454 }
2455 }
2456
2457 return 0;
2458}
2459
2460static void l2cap_le_flowctl_send(struct l2cap_chan *chan)
2461{
2462 int sent = 0;
2463
2464 BT_DBG("chan %p", chan);
2465
2466 while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) {
2467 l2cap_do_send(chan, skb_dequeue(&chan->tx_q));
2468 chan->tx_credits--;
2469 sent++;
2470 }
2471
2472 BT_DBG("Sent %d credits %u queued %u", sent, chan->tx_credits,
2473 skb_queue_len(&chan->tx_q));
2474}
2475
2476int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len)
2477{
2478 struct sk_buff *skb;
2479 int err;
2480 struct sk_buff_head seg_queue;
2481
2482 if (!chan->conn)
2483 return -ENOTCONN;
2484
2485 /* Connectionless channel */
2486 if (chan->chan_type == L2CAP_CHAN_CONN_LESS) {
2487 skb = l2cap_create_connless_pdu(chan, msg, len);
2488 if (IS_ERR(skb))
2489 return PTR_ERR(skb);
2490
2491 /* Channel lock is released before requesting new skb and then
2492 * reacquired thus we need to recheck channel state.
2493 */
2494 if (chan->state != BT_CONNECTED) {
2495 kfree_skb(skb);
2496 return -ENOTCONN;
2497 }
2498
2499 l2cap_do_send(chan, skb);
2500 return len;
2501 }
2502
2503 switch (chan->mode) {
2504 case L2CAP_MODE_LE_FLOWCTL:
2505 /* Check outgoing MTU */
2506 if (len > chan->omtu)
2507 return -EMSGSIZE;
2508
2509 __skb_queue_head_init(&seg_queue);
2510
2511 err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len);
2512
2513 if (chan->state != BT_CONNECTED) {
2514 __skb_queue_purge(&seg_queue);
2515 err = -ENOTCONN;
2516 }
2517
2518 if (err)
2519 return err;
2520
2521 skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
2522
2523 l2cap_le_flowctl_send(chan);
2524
2525 if (!chan->tx_credits)
2526 chan->ops->suspend(chan);
2527
2528 err = len;
2529
2530 break;
2531
2532 case L2CAP_MODE_BASIC:
2533 /* Check outgoing MTU */
2534 if (len > chan->omtu)
2535 return -EMSGSIZE;
2536
2537 /* Create a basic PDU */
2538 skb = l2cap_create_basic_pdu(chan, msg, len);
2539 if (IS_ERR(skb))
2540 return PTR_ERR(skb);
2541
2542 /* Channel lock is released before requesting new skb and then
2543 * reacquired thus we need to recheck channel state.
2544 */
2545 if (chan->state != BT_CONNECTED) {
2546 kfree_skb(skb);
2547 return -ENOTCONN;
2548 }
2549
2550 l2cap_do_send(chan, skb);
2551 err = len;
2552 break;
2553
2554 case L2CAP_MODE_ERTM:
2555 case L2CAP_MODE_STREAMING:
2556 /* Check outgoing MTU */
2557 if (len > chan->omtu) {
2558 err = -EMSGSIZE;
2559 break;
2560 }
2561
2562 __skb_queue_head_init(&seg_queue);
2563
2564 /* Do segmentation before calling in to the state machine,
2565 * since it's possible to block while waiting for memory
2566 * allocation.
2567 */
2568 err = l2cap_segment_sdu(chan, &seg_queue, msg, len);
2569
2570 /* The channel could have been closed while segmenting,
2571 * check that it is still connected.
2572 */
2573 if (chan->state != BT_CONNECTED) {
2574 __skb_queue_purge(&seg_queue);
2575 err = -ENOTCONN;
2576 }
2577
2578 if (err)
2579 break;
2580
2581 if (chan->mode == L2CAP_MODE_ERTM)
2582 l2cap_tx(chan, NULL, &seg_queue, L2CAP_EV_DATA_REQUEST);
2583 else
2584 l2cap_streaming_send(chan, &seg_queue);
2585
2586 err = len;
2587
2588 /* If the skbs were not queued for sending, they'll still be in
2589 * seg_queue and need to be purged.
2590 */
2591 __skb_queue_purge(&seg_queue);
2592 break;
2593
2594 default:
2595 BT_DBG("bad state %1.1x", chan->mode);
2596 err = -EBADFD;
2597 }
2598
2599 return err;
2600}
2601EXPORT_SYMBOL_GPL(l2cap_chan_send);
2602
2603static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq)
2604{
2605 struct l2cap_ctrl control;
2606 u16 seq;
2607
2608 BT_DBG("chan %p, txseq %u", chan, txseq);
2609
2610 memset(&control, 0, sizeof(control));
2611 control.sframe = 1;
2612 control.super = L2CAP_SUPER_SREJ;
2613
2614 for (seq = chan->expected_tx_seq; seq != txseq;
2615 seq = __next_seq(chan, seq)) {
2616 if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) {
2617 control.reqseq = seq;
2618 l2cap_send_sframe(chan, &control);
2619 l2cap_seq_list_append(&chan->srej_list, seq);
2620 }
2621 }
2622
2623 chan->expected_tx_seq = __next_seq(chan, txseq);
2624}
2625
2626static void l2cap_send_srej_tail(struct l2cap_chan *chan)
2627{
2628 struct l2cap_ctrl control;
2629
2630 BT_DBG("chan %p", chan);
2631
2632 if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR)
2633 return;
2634
2635 memset(&control, 0, sizeof(control));
2636 control.sframe = 1;
2637 control.super = L2CAP_SUPER_SREJ;
2638 control.reqseq = chan->srej_list.tail;
2639 l2cap_send_sframe(chan, &control);
2640}
2641
2642static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq)
2643{
2644 struct l2cap_ctrl control;
2645 u16 initial_head;
2646 u16 seq;
2647
2648 BT_DBG("chan %p, txseq %u", chan, txseq);
2649
2650 memset(&control, 0, sizeof(control));
2651 control.sframe = 1;
2652 control.super = L2CAP_SUPER_SREJ;
2653
2654 /* Capture initial list head to allow only one pass through the list. */
2655 initial_head = chan->srej_list.head;
2656
2657 do {
2658 seq = l2cap_seq_list_pop(&chan->srej_list);
2659 if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR)
2660 break;
2661
2662 control.reqseq = seq;
2663 l2cap_send_sframe(chan, &control);
2664 l2cap_seq_list_append(&chan->srej_list, seq);
2665 } while (chan->srej_list.head != initial_head);
2666}
2667
2668static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq)
2669{
2670 struct sk_buff *acked_skb;
2671 u16 ackseq;
2672
2673 BT_DBG("chan %p, reqseq %u", chan, reqseq);
2674
2675 if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq)
2676 return;
2677
2678 BT_DBG("expected_ack_seq %u, unacked_frames %u",
2679 chan->expected_ack_seq, chan->unacked_frames);
2680
2681 for (ackseq = chan->expected_ack_seq; ackseq != reqseq;
2682 ackseq = __next_seq(chan, ackseq)) {
2683
2684 acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq);
2685 if (acked_skb) {
2686 skb_unlink(acked_skb, &chan->tx_q);
2687 kfree_skb(acked_skb);
2688 chan->unacked_frames--;
2689 }
2690 }
2691
2692 chan->expected_ack_seq = reqseq;
2693
2694 if (chan->unacked_frames == 0)
2695 __clear_retrans_timer(chan);
2696
2697 BT_DBG("unacked_frames %u", chan->unacked_frames);
2698}
2699
2700static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan)
2701{
2702 BT_DBG("chan %p", chan);
2703
2704 chan->expected_tx_seq = chan->buffer_seq;
2705 l2cap_seq_list_clear(&chan->srej_list);
2706 skb_queue_purge(&chan->srej_q);
2707 chan->rx_state = L2CAP_RX_STATE_RECV;
2708}
2709
2710static void l2cap_tx_state_xmit(struct l2cap_chan *chan,
2711 struct l2cap_ctrl *control,
2712 struct sk_buff_head *skbs, u8 event)
2713{
2714 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2715 event);
2716
2717 switch (event) {
2718 case L2CAP_EV_DATA_REQUEST:
2719 if (chan->tx_send_head == NULL)
2720 chan->tx_send_head = skb_peek(skbs);
2721
2722 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2723 l2cap_ertm_send(chan);
2724 break;
2725 case L2CAP_EV_LOCAL_BUSY_DETECTED:
2726 BT_DBG("Enter LOCAL_BUSY");
2727 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2728
2729 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2730 /* The SREJ_SENT state must be aborted if we are to
2731 * enter the LOCAL_BUSY state.
2732 */
2733 l2cap_abort_rx_srej_sent(chan);
2734 }
2735
2736 l2cap_send_ack(chan);
2737
2738 break;
2739 case L2CAP_EV_LOCAL_BUSY_CLEAR:
2740 BT_DBG("Exit LOCAL_BUSY");
2741 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2742
2743 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2744 struct l2cap_ctrl local_control;
2745
2746 memset(&local_control, 0, sizeof(local_control));
2747 local_control.sframe = 1;
2748 local_control.super = L2CAP_SUPER_RR;
2749 local_control.poll = 1;
2750 local_control.reqseq = chan->buffer_seq;
2751 l2cap_send_sframe(chan, &local_control);
2752
2753 chan->retry_count = 1;
2754 __set_monitor_timer(chan);
2755 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2756 }
2757 break;
2758 case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2759 l2cap_process_reqseq(chan, control->reqseq);
2760 break;
2761 case L2CAP_EV_EXPLICIT_POLL:
2762 l2cap_send_rr_or_rnr(chan, 1);
2763 chan->retry_count = 1;
2764 __set_monitor_timer(chan);
2765 __clear_ack_timer(chan);
2766 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2767 break;
2768 case L2CAP_EV_RETRANS_TO:
2769 l2cap_send_rr_or_rnr(chan, 1);
2770 chan->retry_count = 1;
2771 __set_monitor_timer(chan);
2772 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2773 break;
2774 case L2CAP_EV_RECV_FBIT:
2775 /* Nothing to process */
2776 break;
2777 default:
2778 break;
2779 }
2780}
2781
2782static void l2cap_tx_state_wait_f(struct l2cap_chan *chan,
2783 struct l2cap_ctrl *control,
2784 struct sk_buff_head *skbs, u8 event)
2785{
2786 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2787 event);
2788
2789 switch (event) {
2790 case L2CAP_EV_DATA_REQUEST:
2791 if (chan->tx_send_head == NULL)
2792 chan->tx_send_head = skb_peek(skbs);
2793 /* Queue data, but don't send. */
2794 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2795 break;
2796 case L2CAP_EV_LOCAL_BUSY_DETECTED:
2797 BT_DBG("Enter LOCAL_BUSY");
2798 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2799
2800 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2801 /* The SREJ_SENT state must be aborted if we are to
2802 * enter the LOCAL_BUSY state.
2803 */
2804 l2cap_abort_rx_srej_sent(chan);
2805 }
2806
2807 l2cap_send_ack(chan);
2808
2809 break;
2810 case L2CAP_EV_LOCAL_BUSY_CLEAR:
2811 BT_DBG("Exit LOCAL_BUSY");
2812 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2813
2814 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2815 struct l2cap_ctrl local_control;
2816 memset(&local_control, 0, sizeof(local_control));
2817 local_control.sframe = 1;
2818 local_control.super = L2CAP_SUPER_RR;
2819 local_control.poll = 1;
2820 local_control.reqseq = chan->buffer_seq;
2821 l2cap_send_sframe(chan, &local_control);
2822
2823 chan->retry_count = 1;
2824 __set_monitor_timer(chan);
2825 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2826 }
2827 break;
2828 case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2829 l2cap_process_reqseq(chan, control->reqseq);
2830
2831 /* Fall through */
2832
2833 case L2CAP_EV_RECV_FBIT:
2834 if (control && control->final) {
2835 __clear_monitor_timer(chan);
2836 if (chan->unacked_frames > 0)
2837 __set_retrans_timer(chan);
2838 chan->retry_count = 0;
2839 chan->tx_state = L2CAP_TX_STATE_XMIT;
2840 BT_DBG("recv fbit tx_state 0x2.2%x", chan->tx_state);
2841 }
2842 break;
2843 case L2CAP_EV_EXPLICIT_POLL:
2844 /* Ignore */
2845 break;
2846 case L2CAP_EV_MONITOR_TO:
2847 if (chan->max_tx == 0 || chan->retry_count < chan->max_tx) {
2848 l2cap_send_rr_or_rnr(chan, 1);
2849 __set_monitor_timer(chan);
2850 chan->retry_count++;
2851 } else {
2852 l2cap_send_disconn_req(chan, ECONNABORTED);
2853 }
2854 break;
2855 default:
2856 break;
2857 }
2858}
2859
2860static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
2861 struct sk_buff_head *skbs, u8 event)
2862{
2863 BT_DBG("chan %p, control %p, skbs %p, event %d, state %d",
2864 chan, control, skbs, event, chan->tx_state);
2865
2866 switch (chan->tx_state) {
2867 case L2CAP_TX_STATE_XMIT:
2868 l2cap_tx_state_xmit(chan, control, skbs, event);
2869 break;
2870 case L2CAP_TX_STATE_WAIT_F:
2871 l2cap_tx_state_wait_f(chan, control, skbs, event);
2872 break;
2873 default:
2874 /* Ignore event */
2875 break;
2876 }
2877}
2878
2879static void l2cap_pass_to_tx(struct l2cap_chan *chan,
2880 struct l2cap_ctrl *control)
2881{
2882 BT_DBG("chan %p, control %p", chan, control);
2883 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_REQSEQ_AND_FBIT);
2884}
2885
2886static void l2cap_pass_to_tx_fbit(struct l2cap_chan *chan,
2887 struct l2cap_ctrl *control)
2888{
2889 BT_DBG("chan %p, control %p", chan, control);
2890 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_FBIT);
2891}
2892
2893/* Copy frame to all raw sockets on that connection */
2894static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
2895{
2896 struct sk_buff *nskb;
2897 struct l2cap_chan *chan;
2898
2899 BT_DBG("conn %p", conn);
2900
2901 mutex_lock(&conn->chan_lock);
2902
2903 list_for_each_entry(chan, &conn->chan_l, list) {
2904 if (chan->chan_type != L2CAP_CHAN_RAW)
2905 continue;
2906
2907 /* Don't send frame to the channel it came from */
2908 if (bt_cb(skb)->l2cap.chan == chan)
2909 continue;
2910
2911 nskb = skb_clone(skb, GFP_KERNEL);
2912 if (!nskb)
2913 continue;
2914 if (chan->ops->recv(chan, nskb))
2915 kfree_skb(nskb);
2916 }
2917
2918 mutex_unlock(&conn->chan_lock);
2919}
2920
2921/* ---- L2CAP signalling commands ---- */
2922static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code,
2923 u8 ident, u16 dlen, void *data)
2924{
2925 struct sk_buff *skb, **frag;
2926 struct l2cap_cmd_hdr *cmd;
2927 struct l2cap_hdr *lh;
2928 int len, count;
2929
2930 BT_DBG("conn %p, code 0x%2.2x, ident 0x%2.2x, len %u",
2931 conn, code, ident, dlen);
2932
2933 if (conn->mtu < L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE)
2934 return NULL;
2935
2936 len = L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE + dlen;
2937 count = min_t(unsigned int, conn->mtu, len);
2938
2939 skb = bt_skb_alloc(count, GFP_KERNEL);
2940 if (!skb)
2941 return NULL;
2942
2943 lh = skb_put(skb, L2CAP_HDR_SIZE);
2944 lh->len = cpu_to_le16(L2CAP_CMD_HDR_SIZE + dlen);
2945
2946 if (conn->hcon->type == LE_LINK)
2947 lh->cid = cpu_to_le16(L2CAP_CID_LE_SIGNALING);
2948 else
2949 lh->cid = cpu_to_le16(L2CAP_CID_SIGNALING);
2950
2951 cmd = skb_put(skb, L2CAP_CMD_HDR_SIZE);
2952 cmd->code = code;
2953 cmd->ident = ident;
2954 cmd->len = cpu_to_le16(dlen);
2955
2956 if (dlen) {
2957 count -= L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE;
2958 skb_put_data(skb, data, count);
2959 data += count;
2960 }
2961
2962 len -= skb->len;
2963
2964 /* Continuation fragments (no L2CAP header) */
2965 frag = &skb_shinfo(skb)->frag_list;
2966 while (len) {
2967 count = min_t(unsigned int, conn->mtu, len);
2968
2969 *frag = bt_skb_alloc(count, GFP_KERNEL);
2970 if (!*frag)
2971 goto fail;
2972
2973 skb_put_data(*frag, data, count);
2974
2975 len -= count;
2976 data += count;
2977
2978 frag = &(*frag)->next;
2979 }
2980
2981 return skb;
2982
2983fail:
2984 kfree_skb(skb);
2985 return NULL;
2986}
2987
2988static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen,
2989 unsigned long *val)
2990{
2991 struct l2cap_conf_opt *opt = *ptr;
2992 int len;
2993
2994 len = L2CAP_CONF_OPT_SIZE + opt->len;
2995 *ptr += len;
2996
2997 *type = opt->type;
2998 *olen = opt->len;
2999
3000 switch (opt->len) {
3001 case 1:
3002 *val = *((u8 *) opt->val);
3003 break;
3004
3005 case 2:
3006 *val = get_unaligned_le16(opt->val);
3007 break;
3008
3009 case 4:
3010 *val = get_unaligned_le32(opt->val);
3011 break;
3012
3013 default:
3014 *val = (unsigned long) opt->val;
3015 break;
3016 }
3017
3018 BT_DBG("type 0x%2.2x len %u val 0x%lx", *type, opt->len, *val);
3019 return len;
3020}
3021
3022static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val, size_t size)
3023{
3024 struct l2cap_conf_opt *opt = *ptr;
3025
3026 BT_DBG("type 0x%2.2x len %u val 0x%lx", type, len, val);
3027
3028 if (size < L2CAP_CONF_OPT_SIZE + len)
3029 return;
3030
3031 opt->type = type;
3032 opt->len = len;
3033
3034 switch (len) {
3035 case 1:
3036 *((u8 *) opt->val) = val;
3037 break;
3038
3039 case 2:
3040 put_unaligned_le16(val, opt->val);
3041 break;
3042
3043 case 4:
3044 put_unaligned_le32(val, opt->val);
3045 break;
3046
3047 default:
3048 memcpy(opt->val, (void *) val, len);
3049 break;
3050 }
3051
3052 *ptr += L2CAP_CONF_OPT_SIZE + len;
3053}
3054
3055static void l2cap_add_opt_efs(void **ptr, struct l2cap_chan *chan, size_t size)
3056{
3057 struct l2cap_conf_efs efs;
3058
3059 switch (chan->mode) {
3060 case L2CAP_MODE_ERTM:
3061 efs.id = chan->local_id;
3062 efs.stype = chan->local_stype;
3063 efs.msdu = cpu_to_le16(chan->local_msdu);
3064 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
3065 efs.acc_lat = cpu_to_le32(L2CAP_DEFAULT_ACC_LAT);
3066 efs.flush_to = cpu_to_le32(L2CAP_EFS_DEFAULT_FLUSH_TO);
3067 break;
3068
3069 case L2CAP_MODE_STREAMING:
3070 efs.id = 1;
3071 efs.stype = L2CAP_SERV_BESTEFFORT;
3072 efs.msdu = cpu_to_le16(chan->local_msdu);
3073 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
3074 efs.acc_lat = 0;
3075 efs.flush_to = 0;
3076 break;
3077
3078 default:
3079 return;
3080 }
3081
3082 l2cap_add_conf_opt(ptr, L2CAP_CONF_EFS, sizeof(efs),
3083 (unsigned long) &efs, size);
3084}
3085
3086static void l2cap_ack_timeout(struct work_struct *work)
3087{
3088 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
3089 ack_timer.work);
3090 u16 frames_to_ack;
3091
3092 BT_DBG("chan %p", chan);
3093
3094 l2cap_chan_lock(chan);
3095
3096 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
3097 chan->last_acked_seq);
3098
3099 if (frames_to_ack)
3100 l2cap_send_rr_or_rnr(chan, 0);
3101
3102 l2cap_chan_unlock(chan);
3103 l2cap_chan_put(chan);
3104}
3105
3106int l2cap_ertm_init(struct l2cap_chan *chan)
3107{
3108 int err;
3109
3110 chan->next_tx_seq = 0;
3111 chan->expected_tx_seq = 0;
3112 chan->expected_ack_seq = 0;
3113 chan->unacked_frames = 0;
3114 chan->buffer_seq = 0;
3115 chan->frames_sent = 0;
3116 chan->last_acked_seq = 0;
3117 chan->sdu = NULL;
3118 chan->sdu_last_frag = NULL;
3119 chan->sdu_len = 0;
3120
3121 skb_queue_head_init(&chan->tx_q);
3122
3123 chan->local_amp_id = AMP_ID_BREDR;
3124 chan->move_id = AMP_ID_BREDR;
3125 chan->move_state = L2CAP_MOVE_STABLE;
3126 chan->move_role = L2CAP_MOVE_ROLE_NONE;
3127
3128 if (chan->mode != L2CAP_MODE_ERTM)
3129 return 0;
3130
3131 chan->rx_state = L2CAP_RX_STATE_RECV;
3132 chan->tx_state = L2CAP_TX_STATE_XMIT;
3133
3134 INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout);
3135 INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout);
3136 INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout);
3137
3138 skb_queue_head_init(&chan->srej_q);
3139
3140 err = l2cap_seq_list_init(&chan->srej_list, chan->tx_win);
3141 if (err < 0)
3142 return err;
3143
3144 err = l2cap_seq_list_init(&chan->retrans_list, chan->remote_tx_win);
3145 if (err < 0)
3146 l2cap_seq_list_free(&chan->srej_list);
3147
3148 return err;
3149}
3150
3151static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
3152{
3153 switch (mode) {
3154 case L2CAP_MODE_STREAMING:
3155 case L2CAP_MODE_ERTM:
3156 if (l2cap_mode_supported(mode, remote_feat_mask))
3157 return mode;
3158 /* fall through */
3159 default:
3160 return L2CAP_MODE_BASIC;
3161 }
3162}
3163
3164static inline bool __l2cap_ews_supported(struct l2cap_conn *conn)
3165{
3166 return ((conn->local_fixed_chan & L2CAP_FC_A2MP) &&
3167 (conn->feat_mask & L2CAP_FEAT_EXT_WINDOW));
3168}
3169
3170static inline bool __l2cap_efs_supported(struct l2cap_conn *conn)
3171{
3172 return ((conn->local_fixed_chan & L2CAP_FC_A2MP) &&
3173 (conn->feat_mask & L2CAP_FEAT_EXT_FLOW));
3174}
3175
3176static void __l2cap_set_ertm_timeouts(struct l2cap_chan *chan,
3177 struct l2cap_conf_rfc *rfc)
3178{
3179 if (chan->local_amp_id != AMP_ID_BREDR && chan->hs_hcon) {
3180 u64 ertm_to = chan->hs_hcon->hdev->amp_be_flush_to;
3181
3182 /* Class 1 devices have must have ERTM timeouts
3183 * exceeding the Link Supervision Timeout. The
3184 * default Link Supervision Timeout for AMP
3185 * controllers is 10 seconds.
3186 *
3187 * Class 1 devices use 0xffffffff for their
3188 * best-effort flush timeout, so the clamping logic
3189 * will result in a timeout that meets the above
3190 * requirement. ERTM timeouts are 16-bit values, so
3191 * the maximum timeout is 65.535 seconds.
3192 */
3193
3194 /* Convert timeout to milliseconds and round */
3195 ertm_to = DIV_ROUND_UP_ULL(ertm_to, 1000);
3196
3197 /* This is the recommended formula for class 2 devices
3198 * that start ERTM timers when packets are sent to the
3199 * controller.
3200 */
3201 ertm_to = 3 * ertm_to + 500;
3202
3203 if (ertm_to > 0xffff)
3204 ertm_to = 0xffff;
3205
3206 rfc->retrans_timeout = cpu_to_le16((u16) ertm_to);
3207 rfc->monitor_timeout = rfc->retrans_timeout;
3208 } else {
3209 rfc->retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO);
3210 rfc->monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO);
3211 }
3212}
3213
3214static inline void l2cap_txwin_setup(struct l2cap_chan *chan)
3215{
3216 if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW &&
3217 __l2cap_ews_supported(chan->conn)) {
3218 /* use extended control field */
3219 set_bit(FLAG_EXT_CTRL, &chan->flags);
3220 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
3221 } else {
3222 chan->tx_win = min_t(u16, chan->tx_win,
3223 L2CAP_DEFAULT_TX_WINDOW);
3224 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
3225 }
3226 chan->ack_win = chan->tx_win;
3227}
3228
3229static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
3230{
3231 struct l2cap_conf_req *req = data;
3232 struct l2cap_conf_rfc rfc = { .mode = chan->mode };
3233 void *ptr = req->data;
3234 void *endptr = data + data_size;
3235 u16 size;
3236
3237 BT_DBG("chan %p", chan);
3238
3239 if (chan->num_conf_req || chan->num_conf_rsp)
3240 goto done;
3241
3242 switch (chan->mode) {
3243 case L2CAP_MODE_STREAMING:
3244 case L2CAP_MODE_ERTM:
3245 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state))
3246 break;
3247
3248 if (__l2cap_efs_supported(chan->conn))
3249 set_bit(FLAG_EFS_ENABLE, &chan->flags);
3250
3251 /* fall through */
3252 default:
3253 chan->mode = l2cap_select_mode(rfc.mode, chan->conn->feat_mask);
3254 break;
3255 }
3256
3257done:
3258 if (chan->imtu != L2CAP_DEFAULT_MTU)
3259 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu, endptr - ptr);
3260
3261 switch (chan->mode) {
3262 case L2CAP_MODE_BASIC:
3263 if (disable_ertm)
3264 break;
3265
3266 if (!(chan->conn->feat_mask & L2CAP_FEAT_ERTM) &&
3267 !(chan->conn->feat_mask & L2CAP_FEAT_STREAMING))
3268 break;
3269
3270 rfc.mode = L2CAP_MODE_BASIC;
3271 rfc.txwin_size = 0;
3272 rfc.max_transmit = 0;
3273 rfc.retrans_timeout = 0;
3274 rfc.monitor_timeout = 0;
3275 rfc.max_pdu_size = 0;
3276
3277 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3278 (unsigned long) &rfc, endptr - ptr);
3279 break;
3280
3281 case L2CAP_MODE_ERTM:
3282 rfc.mode = L2CAP_MODE_ERTM;
3283 rfc.max_transmit = chan->max_tx;
3284
3285 __l2cap_set_ertm_timeouts(chan, &rfc);
3286
3287 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3288 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3289 L2CAP_FCS_SIZE);
3290 rfc.max_pdu_size = cpu_to_le16(size);
3291
3292 l2cap_txwin_setup(chan);
3293
3294 rfc.txwin_size = min_t(u16, chan->tx_win,
3295 L2CAP_DEFAULT_TX_WINDOW);
3296
3297 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3298 (unsigned long) &rfc, endptr - ptr);
3299
3300 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3301 l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
3302
3303 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
3304 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3305 chan->tx_win, endptr - ptr);
3306
3307 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3308 if (chan->fcs == L2CAP_FCS_NONE ||
3309 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3310 chan->fcs = L2CAP_FCS_NONE;
3311 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3312 chan->fcs, endptr - ptr);
3313 }
3314 break;
3315
3316 case L2CAP_MODE_STREAMING:
3317 l2cap_txwin_setup(chan);
3318 rfc.mode = L2CAP_MODE_STREAMING;
3319 rfc.txwin_size = 0;
3320 rfc.max_transmit = 0;
3321 rfc.retrans_timeout = 0;
3322 rfc.monitor_timeout = 0;
3323
3324 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3325 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3326 L2CAP_FCS_SIZE);
3327 rfc.max_pdu_size = cpu_to_le16(size);
3328
3329 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3330 (unsigned long) &rfc, endptr - ptr);
3331
3332 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3333 l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
3334
3335 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3336 if (chan->fcs == L2CAP_FCS_NONE ||
3337 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3338 chan->fcs = L2CAP_FCS_NONE;
3339 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3340 chan->fcs, endptr - ptr);
3341 }
3342 break;
3343 }
3344
3345 req->dcid = cpu_to_le16(chan->dcid);
3346 req->flags = cpu_to_le16(0);
3347
3348 return ptr - data;
3349}
3350
3351static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
3352{
3353 struct l2cap_conf_rsp *rsp = data;
3354 void *ptr = rsp->data;
3355 void *endptr = data + data_size;
3356 void *req = chan->conf_req;
3357 int len = chan->conf_len;
3358 int type, hint, olen;
3359 unsigned long val;
3360 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
3361 struct l2cap_conf_efs efs;
3362 u8 remote_efs = 0;
3363 u16 mtu = L2CAP_DEFAULT_MTU;
3364 u16 result = L2CAP_CONF_SUCCESS;
3365 u16 size;
3366
3367 BT_DBG("chan %p", chan);
3368
3369 while (len >= L2CAP_CONF_OPT_SIZE) {
3370 len -= l2cap_get_conf_opt(&req, &type, &olen, &val);
3371 if (len < 0)
3372 break;
3373
3374 hint = type & L2CAP_CONF_HINT;
3375 type &= L2CAP_CONF_MASK;
3376
3377 switch (type) {
3378 case L2CAP_CONF_MTU:
3379 if (olen != 2)
3380 break;
3381 mtu = val;
3382 break;
3383
3384 case L2CAP_CONF_FLUSH_TO:
3385 if (olen != 2)
3386 break;
3387 chan->flush_to = val;
3388 break;
3389
3390 case L2CAP_CONF_QOS:
3391 break;
3392
3393 case L2CAP_CONF_RFC:
3394 if (olen != sizeof(rfc))
3395 break;
3396 memcpy(&rfc, (void *) val, olen);
3397 break;
3398
3399 case L2CAP_CONF_FCS:
3400 if (olen != 1)
3401 break;
3402 if (val == L2CAP_FCS_NONE)
3403 set_bit(CONF_RECV_NO_FCS, &chan->conf_state);
3404 break;
3405
3406 case L2CAP_CONF_EFS:
3407 if (olen != sizeof(efs))
3408 break;
3409 remote_efs = 1;
3410 memcpy(&efs, (void *) val, olen);
3411 break;
3412
3413 case L2CAP_CONF_EWS:
3414 if (olen != 2)
3415 break;
3416 if (!(chan->conn->local_fixed_chan & L2CAP_FC_A2MP))
3417 return -ECONNREFUSED;
3418 set_bit(FLAG_EXT_CTRL, &chan->flags);
3419 set_bit(CONF_EWS_RECV, &chan->conf_state);
3420 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
3421 chan->remote_tx_win = val;
3422 break;
3423
3424 default:
3425 if (hint)
3426 break;
3427 result = L2CAP_CONF_UNKNOWN;
3428 *((u8 *) ptr++) = type;
3429 break;
3430 }
3431 }
3432
3433 if (chan->num_conf_rsp || chan->num_conf_req > 1)
3434 goto done;
3435
3436 switch (chan->mode) {
3437 case L2CAP_MODE_STREAMING:
3438 case L2CAP_MODE_ERTM:
3439 if (!test_bit(CONF_STATE2_DEVICE, &chan->conf_state)) {
3440 chan->mode = l2cap_select_mode(rfc.mode,
3441 chan->conn->feat_mask);
3442 break;
3443 }
3444
3445 if (remote_efs) {
3446 if (__l2cap_efs_supported(chan->conn))
3447 set_bit(FLAG_EFS_ENABLE, &chan->flags);
3448 else
3449 return -ECONNREFUSED;
3450 }
3451
3452 if (chan->mode != rfc.mode)
3453 return -ECONNREFUSED;
3454
3455 break;
3456 }
3457
3458done:
3459 if (chan->mode != rfc.mode) {
3460 result = L2CAP_CONF_UNACCEPT;
3461 rfc.mode = chan->mode;
3462
3463 if (chan->num_conf_rsp == 1)
3464 return -ECONNREFUSED;
3465
3466 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3467 (unsigned long) &rfc, endptr - ptr);
3468 }
3469
3470 if (result == L2CAP_CONF_SUCCESS) {
3471 /* Configure output options and let the other side know
3472 * which ones we don't like. */
3473
3474 if (mtu < L2CAP_DEFAULT_MIN_MTU)
3475 result = L2CAP_CONF_UNACCEPT;
3476 else {
3477 chan->omtu = mtu;
3478 set_bit(CONF_MTU_DONE, &chan->conf_state);
3479 }
3480 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->omtu, endptr - ptr);
3481
3482 if (remote_efs) {
3483 if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
3484 efs.stype != L2CAP_SERV_NOTRAFIC &&
3485 efs.stype != chan->local_stype) {
3486
3487 result = L2CAP_CONF_UNACCEPT;
3488
3489 if (chan->num_conf_req >= 1)
3490 return -ECONNREFUSED;
3491
3492 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
3493 sizeof(efs),
3494 (unsigned long) &efs, endptr - ptr);
3495 } else {
3496 /* Send PENDING Conf Rsp */
3497 result = L2CAP_CONF_PENDING;
3498 set_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
3499 }
3500 }
3501
3502 switch (rfc.mode) {
3503 case L2CAP_MODE_BASIC:
3504 chan->fcs = L2CAP_FCS_NONE;
3505 set_bit(CONF_MODE_DONE, &chan->conf_state);
3506 break;
3507
3508 case L2CAP_MODE_ERTM:
3509 if (!test_bit(CONF_EWS_RECV, &chan->conf_state))
3510 chan->remote_tx_win = rfc.txwin_size;
3511 else
3512 rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW;
3513
3514 chan->remote_max_tx = rfc.max_transmit;
3515
3516 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
3517 chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
3518 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
3519 rfc.max_pdu_size = cpu_to_le16(size);
3520 chan->remote_mps = size;
3521
3522 __l2cap_set_ertm_timeouts(chan, &rfc);
3523
3524 set_bit(CONF_MODE_DONE, &chan->conf_state);
3525
3526 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
3527 sizeof(rfc), (unsigned long) &rfc, endptr - ptr);
3528
3529 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
3530 chan->remote_id = efs.id;
3531 chan->remote_stype = efs.stype;
3532 chan->remote_msdu = le16_to_cpu(efs.msdu);
3533 chan->remote_flush_to =
3534 le32_to_cpu(efs.flush_to);
3535 chan->remote_acc_lat =
3536 le32_to_cpu(efs.acc_lat);
3537 chan->remote_sdu_itime =
3538 le32_to_cpu(efs.sdu_itime);
3539 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
3540 sizeof(efs),
3541 (unsigned long) &efs, endptr - ptr);
3542 }
3543 break;
3544
3545 case L2CAP_MODE_STREAMING:
3546 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
3547 chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
3548 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
3549 rfc.max_pdu_size = cpu_to_le16(size);
3550 chan->remote_mps = size;
3551
3552 set_bit(CONF_MODE_DONE, &chan->conf_state);
3553
3554 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3555 (unsigned long) &rfc, endptr - ptr);
3556
3557 break;
3558
3559 default:
3560 result = L2CAP_CONF_UNACCEPT;
3561
3562 memset(&rfc, 0, sizeof(rfc));
3563 rfc.mode = chan->mode;
3564 }
3565
3566 if (result == L2CAP_CONF_SUCCESS)
3567 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
3568 }
3569 rsp->scid = cpu_to_le16(chan->dcid);
3570 rsp->result = cpu_to_le16(result);
3571 rsp->flags = cpu_to_le16(0);
3572
3573 return ptr - data;
3574}
3575
3576static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len,
3577 void *data, size_t size, u16 *result)
3578{
3579 struct l2cap_conf_req *req = data;
3580 void *ptr = req->data;
3581 void *endptr = data + size;
3582 int type, olen;
3583 unsigned long val;
3584 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
3585 struct l2cap_conf_efs efs;
3586
3587 BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data);
3588
3589 while (len >= L2CAP_CONF_OPT_SIZE) {
3590 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
3591 if (len < 0)
3592 break;
3593
3594 switch (type) {
3595 case L2CAP_CONF_MTU:
3596 if (olen != 2)
3597 break;
3598 if (val < L2CAP_DEFAULT_MIN_MTU) {
3599 *result = L2CAP_CONF_UNACCEPT;
3600 chan->imtu = L2CAP_DEFAULT_MIN_MTU;
3601 } else
3602 chan->imtu = val;
3603 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu,
3604 endptr - ptr);
3605 break;
3606
3607 case L2CAP_CONF_FLUSH_TO:
3608 if (olen != 2)
3609 break;
3610 chan->flush_to = val;
3611 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, 2,
3612 chan->flush_to, endptr - ptr);
3613 break;
3614
3615 case L2CAP_CONF_RFC:
3616 if (olen != sizeof(rfc))
3617 break;
3618 memcpy(&rfc, (void *)val, olen);
3619 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state) &&
3620 rfc.mode != chan->mode)
3621 return -ECONNREFUSED;
3622 chan->fcs = 0;
3623 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3624 (unsigned long) &rfc, endptr - ptr);
3625 break;
3626
3627 case L2CAP_CONF_EWS:
3628 if (olen != 2)
3629 break;
3630 chan->ack_win = min_t(u16, val, chan->ack_win);
3631 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3632 chan->tx_win, endptr - ptr);
3633 break;
3634
3635 case L2CAP_CONF_EFS:
3636 if (olen != sizeof(efs))
3637 break;
3638 memcpy(&efs, (void *)val, olen);
3639 if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
3640 efs.stype != L2CAP_SERV_NOTRAFIC &&
3641 efs.stype != chan->local_stype)
3642 return -ECONNREFUSED;
3643 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs),
3644 (unsigned long) &efs, endptr - ptr);
3645 break;
3646
3647 case L2CAP_CONF_FCS:
3648 if (olen != 1)
3649 break;
3650 if (*result == L2CAP_CONF_PENDING)
3651 if (val == L2CAP_FCS_NONE)
3652 set_bit(CONF_RECV_NO_FCS,
3653 &chan->conf_state);
3654 break;
3655 }
3656 }
3657
3658 if (chan->mode == L2CAP_MODE_BASIC && chan->mode != rfc.mode)
3659 return -ECONNREFUSED;
3660
3661 chan->mode = rfc.mode;
3662
3663 if (*result == L2CAP_CONF_SUCCESS || *result == L2CAP_CONF_PENDING) {
3664 switch (rfc.mode) {
3665 case L2CAP_MODE_ERTM:
3666 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
3667 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
3668 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3669 if (!test_bit(FLAG_EXT_CTRL, &chan->flags))
3670 chan->ack_win = min_t(u16, chan->ack_win,
3671 rfc.txwin_size);
3672
3673 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
3674 chan->local_msdu = le16_to_cpu(efs.msdu);
3675 chan->local_sdu_itime =
3676 le32_to_cpu(efs.sdu_itime);
3677 chan->local_acc_lat = le32_to_cpu(efs.acc_lat);
3678 chan->local_flush_to =
3679 le32_to_cpu(efs.flush_to);
3680 }
3681 break;
3682
3683 case L2CAP_MODE_STREAMING:
3684 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3685 }
3686 }
3687
3688 req->dcid = cpu_to_le16(chan->dcid);
3689 req->flags = cpu_to_le16(0);
3690
3691 return ptr - data;
3692}
3693
3694static int l2cap_build_conf_rsp(struct l2cap_chan *chan, void *data,
3695 u16 result, u16 flags)
3696{
3697 struct l2cap_conf_rsp *rsp = data;
3698 void *ptr = rsp->data;
3699
3700 BT_DBG("chan %p", chan);
3701
3702 rsp->scid = cpu_to_le16(chan->dcid);
3703 rsp->result = cpu_to_le16(result);
3704 rsp->flags = cpu_to_le16(flags);
3705
3706 return ptr - data;
3707}
3708
3709void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan)
3710{
3711 struct l2cap_le_conn_rsp rsp;
3712 struct l2cap_conn *conn = chan->conn;
3713
3714 BT_DBG("chan %p", chan);
3715
3716 rsp.dcid = cpu_to_le16(chan->scid);
3717 rsp.mtu = cpu_to_le16(chan->imtu);
3718 rsp.mps = cpu_to_le16(chan->mps);
3719 rsp.credits = cpu_to_le16(chan->rx_credits);
3720 rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS);
3721
3722 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
3723 &rsp);
3724}
3725
3726void __l2cap_connect_rsp_defer(struct l2cap_chan *chan)
3727{
3728 struct l2cap_conn_rsp rsp;
3729 struct l2cap_conn *conn = chan->conn;
3730 u8 buf[128];
3731 u8 rsp_code;
3732
3733 rsp.scid = cpu_to_le16(chan->dcid);
3734 rsp.dcid = cpu_to_le16(chan->scid);
3735 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
3736 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
3737
3738 if (chan->hs_hcon)
3739 rsp_code = L2CAP_CREATE_CHAN_RSP;
3740 else
3741 rsp_code = L2CAP_CONN_RSP;
3742
3743 BT_DBG("chan %p rsp_code %u", chan, rsp_code);
3744
3745 l2cap_send_cmd(conn, chan->ident, rsp_code, sizeof(rsp), &rsp);
3746
3747 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
3748 return;
3749
3750 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
3751 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
3752 chan->num_conf_req++;
3753}
3754
3755static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len)
3756{
3757 int type, olen;
3758 unsigned long val;
3759 /* Use sane default values in case a misbehaving remote device
3760 * did not send an RFC or extended window size option.
3761 */
3762 u16 txwin_ext = chan->ack_win;
3763 struct l2cap_conf_rfc rfc = {
3764 .mode = chan->mode,
3765 .retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO),
3766 .monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO),
3767 .max_pdu_size = cpu_to_le16(chan->imtu),
3768 .txwin_size = min_t(u16, chan->ack_win, L2CAP_DEFAULT_TX_WINDOW),
3769 };
3770
3771 BT_DBG("chan %p, rsp %p, len %d", chan, rsp, len);
3772
3773 if ((chan->mode != L2CAP_MODE_ERTM) && (chan->mode != L2CAP_MODE_STREAMING))
3774 return;
3775
3776 while (len >= L2CAP_CONF_OPT_SIZE) {
3777 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
3778 if (len < 0)
3779 break;
3780
3781 switch (type) {
3782 case L2CAP_CONF_RFC:
3783 if (olen != sizeof(rfc))
3784 break;
3785 memcpy(&rfc, (void *)val, olen);
3786 break;
3787 case L2CAP_CONF_EWS:
3788 if (olen != 2)
3789 break;
3790 txwin_ext = val;
3791 break;
3792 }
3793 }
3794
3795 switch (rfc.mode) {
3796 case L2CAP_MODE_ERTM:
3797 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
3798 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
3799 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3800 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
3801 chan->ack_win = min_t(u16, chan->ack_win, txwin_ext);
3802 else
3803 chan->ack_win = min_t(u16, chan->ack_win,
3804 rfc.txwin_size);
3805 break;
3806 case L2CAP_MODE_STREAMING:
3807 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3808 }
3809}
3810
3811static inline int l2cap_command_rej(struct l2cap_conn *conn,
3812 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
3813 u8 *data)
3814{
3815 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
3816
3817 if (cmd_len < sizeof(*rej))
3818 return -EPROTO;
3819
3820 if (rej->reason != L2CAP_REJ_NOT_UNDERSTOOD)
3821 return 0;
3822
3823 if ((conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) &&
3824 cmd->ident == conn->info_ident) {
3825 cancel_delayed_work(&conn->info_timer);
3826
3827 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
3828 conn->info_ident = 0;
3829
3830 l2cap_conn_start(conn);
3831 }
3832
3833 return 0;
3834}
3835
3836static struct l2cap_chan *l2cap_connect(struct l2cap_conn *conn,
3837 struct l2cap_cmd_hdr *cmd,
3838 u8 *data, u8 rsp_code, u8 amp_id)
3839{
3840 struct l2cap_conn_req *req = (struct l2cap_conn_req *) data;
3841 struct l2cap_conn_rsp rsp;
3842 struct l2cap_chan *chan = NULL, *pchan;
3843 int result, status = L2CAP_CS_NO_INFO;
3844
3845 u16 dcid = 0, scid = __le16_to_cpu(req->scid);
3846 __le16 psm = req->psm;
3847
3848 BT_DBG("psm 0x%2.2x scid 0x%4.4x", __le16_to_cpu(psm), scid);
3849
3850 /* Check if we have socket listening on psm */
3851 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
3852 &conn->hcon->dst, ACL_LINK);
3853 if (!pchan) {
3854 result = L2CAP_CR_BAD_PSM;
3855 goto sendresp;
3856 }
3857
3858 mutex_lock(&conn->chan_lock);
3859 l2cap_chan_lock(pchan);
3860
3861 /* Check if the ACL is secure enough (if not SDP) */
3862 if (psm != cpu_to_le16(L2CAP_PSM_SDP) &&
3863 !hci_conn_check_link_mode(conn->hcon)) {
3864 conn->disc_reason = HCI_ERROR_AUTH_FAILURE;
3865 result = L2CAP_CR_SEC_BLOCK;
3866 goto response;
3867 }
3868
3869 result = L2CAP_CR_NO_MEM;
3870
3871 /* Check for valid dynamic CID range (as per Erratum 3253) */
3872 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) {
3873 result = L2CAP_CR_INVALID_SCID;
3874 goto response;
3875 }
3876
3877 /* Check if we already have channel with that dcid */
3878 if (__l2cap_get_chan_by_dcid(conn, scid)) {
3879 result = L2CAP_CR_SCID_IN_USE;
3880 goto response;
3881 }
3882
3883 chan = pchan->ops->new_connection(pchan);
3884 if (!chan)
3885 goto response;
3886
3887 /* For certain devices (ex: HID mouse), support for authentication,
3888 * pairing and bonding is optional. For such devices, inorder to avoid
3889 * the ACL alive for too long after L2CAP disconnection, reset the ACL
3890 * disc_timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect.
3891 */
3892 conn->hcon->disc_timeout = HCI_DISCONN_TIMEOUT;
3893
3894 bacpy(&chan->src, &conn->hcon->src);
3895 bacpy(&chan->dst, &conn->hcon->dst);
3896 chan->src_type = bdaddr_src_type(conn->hcon);
3897 chan->dst_type = bdaddr_dst_type(conn->hcon);
3898 chan->psm = psm;
3899 chan->dcid = scid;
3900 chan->local_amp_id = amp_id;
3901
3902 __l2cap_chan_add(conn, chan);
3903
3904 dcid = chan->scid;
3905
3906 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
3907
3908 chan->ident = cmd->ident;
3909
3910 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) {
3911 if (l2cap_chan_check_security(chan, false)) {
3912 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
3913 l2cap_state_change(chan, BT_CONNECT2);
3914 result = L2CAP_CR_PEND;
3915 status = L2CAP_CS_AUTHOR_PEND;
3916 chan->ops->defer(chan);
3917 } else {
3918 /* Force pending result for AMP controllers.
3919 * The connection will succeed after the
3920 * physical link is up.
3921 */
3922 if (amp_id == AMP_ID_BREDR) {
3923 l2cap_state_change(chan, BT_CONFIG);
3924 result = L2CAP_CR_SUCCESS;
3925 } else {
3926 l2cap_state_change(chan, BT_CONNECT2);
3927 result = L2CAP_CR_PEND;
3928 }
3929 status = L2CAP_CS_NO_INFO;
3930 }
3931 } else {
3932 l2cap_state_change(chan, BT_CONNECT2);
3933 result = L2CAP_CR_PEND;
3934 status = L2CAP_CS_AUTHEN_PEND;
3935 }
3936 } else {
3937 l2cap_state_change(chan, BT_CONNECT2);
3938 result = L2CAP_CR_PEND;
3939 status = L2CAP_CS_NO_INFO;
3940 }
3941
3942response:
3943 l2cap_chan_unlock(pchan);
3944 mutex_unlock(&conn->chan_lock);
3945 l2cap_chan_put(pchan);
3946
3947sendresp:
3948 rsp.scid = cpu_to_le16(scid);
3949 rsp.dcid = cpu_to_le16(dcid);
3950 rsp.result = cpu_to_le16(result);
3951 rsp.status = cpu_to_le16(status);
3952 l2cap_send_cmd(conn, cmd->ident, rsp_code, sizeof(rsp), &rsp);
3953
3954 if (result == L2CAP_CR_PEND && status == L2CAP_CS_NO_INFO) {
3955 struct l2cap_info_req info;
3956 info.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
3957
3958 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
3959 conn->info_ident = l2cap_get_ident(conn);
3960
3961 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
3962
3963 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
3964 sizeof(info), &info);
3965 }
3966
3967 if (chan && !test_bit(CONF_REQ_SENT, &chan->conf_state) &&
3968 result == L2CAP_CR_SUCCESS) {
3969 u8 buf[128];
3970 set_bit(CONF_REQ_SENT, &chan->conf_state);
3971 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
3972 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
3973 chan->num_conf_req++;
3974 }
3975
3976 return chan;
3977}
3978
3979static int l2cap_connect_req(struct l2cap_conn *conn,
3980 struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
3981{
3982 struct hci_dev *hdev = conn->hcon->hdev;
3983 struct hci_conn *hcon = conn->hcon;
3984
3985 if (cmd_len < sizeof(struct l2cap_conn_req))
3986 return -EPROTO;
3987
3988 hci_dev_lock(hdev);
3989 if (hci_dev_test_flag(hdev, HCI_MGMT) &&
3990 !test_and_set_bit(HCI_CONN_MGMT_CONNECTED, &hcon->flags))
3991 mgmt_device_connected(hdev, hcon, 0, NULL, 0);
3992 hci_dev_unlock(hdev);
3993
3994 l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP, 0);
3995 return 0;
3996}
3997
3998static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
3999 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4000 u8 *data)
4001{
4002 struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data;
4003 u16 scid, dcid, result, status;
4004 struct l2cap_chan *chan;
4005 u8 req[128];
4006 int err;
4007
4008 if (cmd_len < sizeof(*rsp))
4009 return -EPROTO;
4010
4011 scid = __le16_to_cpu(rsp->scid);
4012 dcid = __le16_to_cpu(rsp->dcid);
4013 result = __le16_to_cpu(rsp->result);
4014 status = __le16_to_cpu(rsp->status);
4015
4016 BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x",
4017 dcid, scid, result, status);
4018
4019 mutex_lock(&conn->chan_lock);
4020
4021 if (scid) {
4022 chan = __l2cap_get_chan_by_scid(conn, scid);
4023 if (!chan) {
4024 err = -EBADSLT;
4025 goto unlock;
4026 }
4027 } else {
4028 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
4029 if (!chan) {
4030 err = -EBADSLT;
4031 goto unlock;
4032 }
4033 }
4034
4035 err = 0;
4036
4037 l2cap_chan_lock(chan);
4038
4039 switch (result) {
4040 case L2CAP_CR_SUCCESS:
4041 l2cap_state_change(chan, BT_CONFIG);
4042 chan->ident = 0;
4043 chan->dcid = dcid;
4044 clear_bit(CONF_CONNECT_PEND, &chan->conf_state);
4045
4046 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
4047 break;
4048
4049 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4050 l2cap_build_conf_req(chan, req, sizeof(req)), req);
4051 chan->num_conf_req++;
4052 break;
4053
4054 case L2CAP_CR_PEND:
4055 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
4056 break;
4057
4058 default:
4059 l2cap_chan_del(chan, ECONNREFUSED);
4060 break;
4061 }
4062
4063 l2cap_chan_unlock(chan);
4064
4065unlock:
4066 mutex_unlock(&conn->chan_lock);
4067
4068 return err;
4069}
4070
4071static inline void set_default_fcs(struct l2cap_chan *chan)
4072{
4073 /* FCS is enabled only in ERTM or streaming mode, if one or both
4074 * sides request it.
4075 */
4076 if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING)
4077 chan->fcs = L2CAP_FCS_NONE;
4078 else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state))
4079 chan->fcs = L2CAP_FCS_CRC16;
4080}
4081
4082static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data,
4083 u8 ident, u16 flags)
4084{
4085 struct l2cap_conn *conn = chan->conn;
4086
4087 BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident,
4088 flags);
4089
4090 clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
4091 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
4092
4093 l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP,
4094 l2cap_build_conf_rsp(chan, data,
4095 L2CAP_CONF_SUCCESS, flags), data);
4096}
4097
4098static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident,
4099 u16 scid, u16 dcid)
4100{
4101 struct l2cap_cmd_rej_cid rej;
4102
4103 rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID);
4104 rej.scid = __cpu_to_le16(scid);
4105 rej.dcid = __cpu_to_le16(dcid);
4106
4107 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
4108}
4109
4110static inline int l2cap_config_req(struct l2cap_conn *conn,
4111 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4112 u8 *data)
4113{
4114 struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
4115 u16 dcid, flags;
4116 u8 rsp[64];
4117 struct l2cap_chan *chan;
4118 int len, err = 0;
4119
4120 if (cmd_len < sizeof(*req))
4121 return -EPROTO;
4122
4123 dcid = __le16_to_cpu(req->dcid);
4124 flags = __le16_to_cpu(req->flags);
4125
4126 BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags);
4127
4128 chan = l2cap_get_chan_by_scid(conn, dcid);
4129 if (!chan) {
4130 cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0);
4131 return 0;
4132 }
4133
4134 if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2) {
4135 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
4136 chan->dcid);
4137 goto unlock;
4138 }
4139
4140 /* Reject if config buffer is too small. */
4141 len = cmd_len - sizeof(*req);
4142 if (chan->conf_len + len > sizeof(chan->conf_req)) {
4143 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4144 l2cap_build_conf_rsp(chan, rsp,
4145 L2CAP_CONF_REJECT, flags), rsp);
4146 goto unlock;
4147 }
4148
4149 /* Store config. */
4150 memcpy(chan->conf_req + chan->conf_len, req->data, len);
4151 chan->conf_len += len;
4152
4153 if (flags & L2CAP_CONF_FLAG_CONTINUATION) {
4154 /* Incomplete config. Send empty response. */
4155 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4156 l2cap_build_conf_rsp(chan, rsp,
4157 L2CAP_CONF_SUCCESS, flags), rsp);
4158 goto unlock;
4159 }
4160
4161 /* Complete config. */
4162 len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp));
4163 if (len < 0) {
4164 l2cap_send_disconn_req(chan, ECONNRESET);
4165 goto unlock;
4166 }
4167
4168 chan->ident = cmd->ident;
4169 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp);
4170 chan->num_conf_rsp++;
4171
4172 /* Reset config buffer. */
4173 chan->conf_len = 0;
4174
4175 if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state))
4176 goto unlock;
4177
4178 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
4179 set_default_fcs(chan);
4180
4181 if (chan->mode == L2CAP_MODE_ERTM ||
4182 chan->mode == L2CAP_MODE_STREAMING)
4183 err = l2cap_ertm_init(chan);
4184
4185 if (err < 0)
4186 l2cap_send_disconn_req(chan, -err);
4187 else
4188 l2cap_chan_ready(chan);
4189
4190 goto unlock;
4191 }
4192
4193 if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) {
4194 u8 buf[64];
4195 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4196 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4197 chan->num_conf_req++;
4198 }
4199
4200 /* Got Conf Rsp PENDING from remote side and assume we sent
4201 Conf Rsp PENDING in the code above */
4202 if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) &&
4203 test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4204
4205 /* check compatibility */
4206
4207 /* Send rsp for BR/EDR channel */
4208 if (!chan->hs_hcon)
4209 l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags);
4210 else
4211 chan->ident = cmd->ident;
4212 }
4213
4214unlock:
4215 l2cap_chan_unlock(chan);
4216 return err;
4217}
4218
4219static inline int l2cap_config_rsp(struct l2cap_conn *conn,
4220 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4221 u8 *data)
4222{
4223 struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data;
4224 u16 scid, flags, result;
4225 struct l2cap_chan *chan;
4226 int len = cmd_len - sizeof(*rsp);
4227 int err = 0;
4228
4229 if (cmd_len < sizeof(*rsp))
4230 return -EPROTO;
4231
4232 scid = __le16_to_cpu(rsp->scid);
4233 flags = __le16_to_cpu(rsp->flags);
4234 result = __le16_to_cpu(rsp->result);
4235
4236 BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags,
4237 result, len);
4238
4239 chan = l2cap_get_chan_by_scid(conn, scid);
4240 if (!chan)
4241 return 0;
4242
4243 switch (result) {
4244 case L2CAP_CONF_SUCCESS:
4245 l2cap_conf_rfc_get(chan, rsp->data, len);
4246 clear_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4247 break;
4248
4249 case L2CAP_CONF_PENDING:
4250 set_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4251
4252 if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4253 char buf[64];
4254
4255 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4256 buf, sizeof(buf), &result);
4257 if (len < 0) {
4258 l2cap_send_disconn_req(chan, ECONNRESET);
4259 goto done;
4260 }
4261
4262 if (!chan->hs_hcon) {
4263 l2cap_send_efs_conf_rsp(chan, buf, cmd->ident,
4264 0);
4265 } else {
4266 if (l2cap_check_efs(chan)) {
4267 amp_create_logical_link(chan);
4268 chan->ident = cmd->ident;
4269 }
4270 }
4271 }
4272 goto done;
4273
4274 case L2CAP_CONF_UNACCEPT:
4275 if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) {
4276 char req[64];
4277
4278 if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) {
4279 l2cap_send_disconn_req(chan, ECONNRESET);
4280 goto done;
4281 }
4282
4283 /* throw out any old stored conf requests */
4284 result = L2CAP_CONF_SUCCESS;
4285 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4286 req, sizeof(req), &result);
4287 if (len < 0) {
4288 l2cap_send_disconn_req(chan, ECONNRESET);
4289 goto done;
4290 }
4291
4292 l2cap_send_cmd(conn, l2cap_get_ident(conn),
4293 L2CAP_CONF_REQ, len, req);
4294 chan->num_conf_req++;
4295 if (result != L2CAP_CONF_SUCCESS)
4296 goto done;
4297 break;
4298 }
4299 /* fall through */
4300
4301 default:
4302 l2cap_chan_set_err(chan, ECONNRESET);
4303
4304 __set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT);
4305 l2cap_send_disconn_req(chan, ECONNRESET);
4306 goto done;
4307 }
4308
4309 if (flags & L2CAP_CONF_FLAG_CONTINUATION)
4310 goto done;
4311
4312 set_bit(CONF_INPUT_DONE, &chan->conf_state);
4313
4314 if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) {
4315 set_default_fcs(chan);
4316
4317 if (chan->mode == L2CAP_MODE_ERTM ||
4318 chan->mode == L2CAP_MODE_STREAMING)
4319 err = l2cap_ertm_init(chan);
4320
4321 if (err < 0)
4322 l2cap_send_disconn_req(chan, -err);
4323 else
4324 l2cap_chan_ready(chan);
4325 }
4326
4327done:
4328 l2cap_chan_unlock(chan);
4329 return err;
4330}
4331
4332static inline int l2cap_disconnect_req(struct l2cap_conn *conn,
4333 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4334 u8 *data)
4335{
4336 struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data;
4337 struct l2cap_disconn_rsp rsp;
4338 u16 dcid, scid;
4339 struct l2cap_chan *chan;
4340
4341 if (cmd_len != sizeof(*req))
4342 return -EPROTO;
4343
4344 scid = __le16_to_cpu(req->scid);
4345 dcid = __le16_to_cpu(req->dcid);
4346
4347 BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
4348
4349 mutex_lock(&conn->chan_lock);
4350
4351 chan = __l2cap_get_chan_by_scid(conn, dcid);
4352 if (!chan) {
4353 mutex_unlock(&conn->chan_lock);
4354 cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid);
4355 return 0;
4356 }
4357
4358 l2cap_chan_lock(chan);
4359
4360 rsp.dcid = cpu_to_le16(chan->scid);
4361 rsp.scid = cpu_to_le16(chan->dcid);
4362 l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
4363
4364 chan->ops->set_shutdown(chan);
4365
4366 l2cap_chan_hold(chan);
4367 l2cap_chan_del(chan, ECONNRESET);
4368
4369 l2cap_chan_unlock(chan);
4370
4371 chan->ops->close(chan);
4372 l2cap_chan_put(chan);
4373
4374 mutex_unlock(&conn->chan_lock);
4375
4376 return 0;
4377}
4378
4379static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,
4380 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4381 u8 *data)
4382{
4383 struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data;
4384 u16 dcid, scid;
4385 struct l2cap_chan *chan;
4386
4387 if (cmd_len != sizeof(*rsp))
4388 return -EPROTO;
4389
4390 scid = __le16_to_cpu(rsp->scid);
4391 dcid = __le16_to_cpu(rsp->dcid);
4392
4393 BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
4394
4395 mutex_lock(&conn->chan_lock);
4396
4397 chan = __l2cap_get_chan_by_scid(conn, scid);
4398 if (!chan) {
4399 mutex_unlock(&conn->chan_lock);
4400 return 0;
4401 }
4402
4403 l2cap_chan_lock(chan);
4404
4405 if (chan->state != BT_DISCONN) {
4406 l2cap_chan_unlock(chan);
4407 mutex_unlock(&conn->chan_lock);
4408 return 0;
4409 }
4410
4411 l2cap_chan_hold(chan);
4412 l2cap_chan_del(chan, 0);
4413
4414 l2cap_chan_unlock(chan);
4415
4416 chan->ops->close(chan);
4417 l2cap_chan_put(chan);
4418
4419 mutex_unlock(&conn->chan_lock);
4420
4421 return 0;
4422}
4423
4424static inline int l2cap_information_req(struct l2cap_conn *conn,
4425 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4426 u8 *data)
4427{
4428 struct l2cap_info_req *req = (struct l2cap_info_req *) data;
4429 u16 type;
4430
4431 if (cmd_len != sizeof(*req))
4432 return -EPROTO;
4433
4434 type = __le16_to_cpu(req->type);
4435
4436 BT_DBG("type 0x%4.4x", type);
4437
4438 if (type == L2CAP_IT_FEAT_MASK) {
4439 u8 buf[8];
4440 u32 feat_mask = l2cap_feat_mask;
4441 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4442 rsp->type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
4443 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4444 if (!disable_ertm)
4445 feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING
4446 | L2CAP_FEAT_FCS;
4447 if (conn->local_fixed_chan & L2CAP_FC_A2MP)
4448 feat_mask |= L2CAP_FEAT_EXT_FLOW
4449 | L2CAP_FEAT_EXT_WINDOW;
4450
4451 put_unaligned_le32(feat_mask, rsp->data);
4452 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4453 buf);
4454 } else if (type == L2CAP_IT_FIXED_CHAN) {
4455 u8 buf[12];
4456 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4457
4458 rsp->type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4459 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4460 rsp->data[0] = conn->local_fixed_chan;
4461 memset(rsp->data + 1, 0, 7);
4462 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4463 buf);
4464 } else {
4465 struct l2cap_info_rsp rsp;
4466 rsp.type = cpu_to_le16(type);
4467 rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP);
4468 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp),
4469 &rsp);
4470 }
4471
4472 return 0;
4473}
4474
4475static inline int l2cap_information_rsp(struct l2cap_conn *conn,
4476 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4477 u8 *data)
4478{
4479 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data;
4480 u16 type, result;
4481
4482 if (cmd_len < sizeof(*rsp))
4483 return -EPROTO;
4484
4485 type = __le16_to_cpu(rsp->type);
4486 result = __le16_to_cpu(rsp->result);
4487
4488 BT_DBG("type 0x%4.4x result 0x%2.2x", type, result);
4489
4490 /* L2CAP Info req/rsp are unbound to channels, add extra checks */
4491 if (cmd->ident != conn->info_ident ||
4492 conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
4493 return 0;
4494
4495 cancel_delayed_work(&conn->info_timer);
4496
4497 if (result != L2CAP_IR_SUCCESS) {
4498 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4499 conn->info_ident = 0;
4500
4501 l2cap_conn_start(conn);
4502
4503 return 0;
4504 }
4505
4506 switch (type) {
4507 case L2CAP_IT_FEAT_MASK:
4508 conn->feat_mask = get_unaligned_le32(rsp->data);
4509
4510 if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) {
4511 struct l2cap_info_req req;
4512 req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4513
4514 conn->info_ident = l2cap_get_ident(conn);
4515
4516 l2cap_send_cmd(conn, conn->info_ident,
4517 L2CAP_INFO_REQ, sizeof(req), &req);
4518 } else {
4519 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4520 conn->info_ident = 0;
4521
4522 l2cap_conn_start(conn);
4523 }
4524 break;
4525
4526 case L2CAP_IT_FIXED_CHAN:
4527 conn->remote_fixed_chan = rsp->data[0];
4528 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4529 conn->info_ident = 0;
4530
4531 l2cap_conn_start(conn);
4532 break;
4533 }
4534
4535 return 0;
4536}
4537
4538static int l2cap_create_channel_req(struct l2cap_conn *conn,
4539 struct l2cap_cmd_hdr *cmd,
4540 u16 cmd_len, void *data)
4541{
4542 struct l2cap_create_chan_req *req = data;
4543 struct l2cap_create_chan_rsp rsp;
4544 struct l2cap_chan *chan;
4545 struct hci_dev *hdev;
4546 u16 psm, scid;
4547
4548 if (cmd_len != sizeof(*req))
4549 return -EPROTO;
4550
4551 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
4552 return -EINVAL;
4553
4554 psm = le16_to_cpu(req->psm);
4555 scid = le16_to_cpu(req->scid);
4556
4557 BT_DBG("psm 0x%2.2x, scid 0x%4.4x, amp_id %d", psm, scid, req->amp_id);
4558
4559 /* For controller id 0 make BR/EDR connection */
4560 if (req->amp_id == AMP_ID_BREDR) {
4561 l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP,
4562 req->amp_id);
4563 return 0;
4564 }
4565
4566 /* Validate AMP controller id */
4567 hdev = hci_dev_get(req->amp_id);
4568 if (!hdev)
4569 goto error;
4570
4571 if (hdev->dev_type != HCI_AMP || !test_bit(HCI_UP, &hdev->flags)) {
4572 hci_dev_put(hdev);
4573 goto error;
4574 }
4575
4576 chan = l2cap_connect(conn, cmd, data, L2CAP_CREATE_CHAN_RSP,
4577 req->amp_id);
4578 if (chan) {
4579 struct amp_mgr *mgr = conn->hcon->amp_mgr;
4580 struct hci_conn *hs_hcon;
4581
4582 hs_hcon = hci_conn_hash_lookup_ba(hdev, AMP_LINK,
4583 &conn->hcon->dst);
4584 if (!hs_hcon) {
4585 hci_dev_put(hdev);
4586 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
4587 chan->dcid);
4588 return 0;
4589 }
4590
4591 BT_DBG("mgr %p bredr_chan %p hs_hcon %p", mgr, chan, hs_hcon);
4592
4593 mgr->bredr_chan = chan;
4594 chan->hs_hcon = hs_hcon;
4595 chan->fcs = L2CAP_FCS_NONE;
4596 conn->mtu = hdev->block_mtu;
4597 }
4598
4599 hci_dev_put(hdev);
4600
4601 return 0;
4602
4603error:
4604 rsp.dcid = 0;
4605 rsp.scid = cpu_to_le16(scid);
4606 rsp.result = cpu_to_le16(L2CAP_CR_BAD_AMP);
4607 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
4608
4609 l2cap_send_cmd(conn, cmd->ident, L2CAP_CREATE_CHAN_RSP,
4610 sizeof(rsp), &rsp);
4611
4612 return 0;
4613}
4614
4615static void l2cap_send_move_chan_req(struct l2cap_chan *chan, u8 dest_amp_id)
4616{
4617 struct l2cap_move_chan_req req;
4618 u8 ident;
4619
4620 BT_DBG("chan %p, dest_amp_id %d", chan, dest_amp_id);
4621
4622 ident = l2cap_get_ident(chan->conn);
4623 chan->ident = ident;
4624
4625 req.icid = cpu_to_le16(chan->scid);
4626 req.dest_amp_id = dest_amp_id;
4627
4628 l2cap_send_cmd(chan->conn, ident, L2CAP_MOVE_CHAN_REQ, sizeof(req),
4629 &req);
4630
4631 __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
4632}
4633
4634static void l2cap_send_move_chan_rsp(struct l2cap_chan *chan, u16 result)
4635{
4636 struct l2cap_move_chan_rsp rsp;
4637
4638 BT_DBG("chan %p, result 0x%4.4x", chan, result);
4639
4640 rsp.icid = cpu_to_le16(chan->dcid);
4641 rsp.result = cpu_to_le16(result);
4642
4643 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_RSP,
4644 sizeof(rsp), &rsp);
4645}
4646
4647static void l2cap_send_move_chan_cfm(struct l2cap_chan *chan, u16 result)
4648{
4649 struct l2cap_move_chan_cfm cfm;
4650
4651 BT_DBG("chan %p, result 0x%4.4x", chan, result);
4652
4653 chan->ident = l2cap_get_ident(chan->conn);
4654
4655 cfm.icid = cpu_to_le16(chan->scid);
4656 cfm.result = cpu_to_le16(result);
4657
4658 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_MOVE_CHAN_CFM,
4659 sizeof(cfm), &cfm);
4660
4661 __set_chan_timer(chan, L2CAP_MOVE_TIMEOUT);
4662}
4663
4664static void l2cap_send_move_chan_cfm_icid(struct l2cap_conn *conn, u16 icid)
4665{
4666 struct l2cap_move_chan_cfm cfm;
4667
4668 BT_DBG("conn %p, icid 0x%4.4x", conn, icid);
4669
4670 cfm.icid = cpu_to_le16(icid);
4671 cfm.result = cpu_to_le16(L2CAP_MC_UNCONFIRMED);
4672
4673 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_MOVE_CHAN_CFM,
4674 sizeof(cfm), &cfm);
4675}
4676
4677static void l2cap_send_move_chan_cfm_rsp(struct l2cap_conn *conn, u8 ident,
4678 u16 icid)
4679{
4680 struct l2cap_move_chan_cfm_rsp rsp;
4681
4682 BT_DBG("icid 0x%4.4x", icid);
4683
4684 rsp.icid = cpu_to_le16(icid);
4685 l2cap_send_cmd(conn, ident, L2CAP_MOVE_CHAN_CFM_RSP, sizeof(rsp), &rsp);
4686}
4687
4688static void __release_logical_link(struct l2cap_chan *chan)
4689{
4690 chan->hs_hchan = NULL;
4691 chan->hs_hcon = NULL;
4692
4693 /* Placeholder - release the logical link */
4694}
4695
4696static void l2cap_logical_fail(struct l2cap_chan *chan)
4697{
4698 /* Logical link setup failed */
4699 if (chan->state != BT_CONNECTED) {
4700 /* Create channel failure, disconnect */
4701 l2cap_send_disconn_req(chan, ECONNRESET);
4702 return;
4703 }
4704
4705 switch (chan->move_role) {
4706 case L2CAP_MOVE_ROLE_RESPONDER:
4707 l2cap_move_done(chan);
4708 l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_SUPP);
4709 break;
4710 case L2CAP_MOVE_ROLE_INITIATOR:
4711 if (chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_COMP ||
4712 chan->move_state == L2CAP_MOVE_WAIT_LOGICAL_CFM) {
4713 /* Remote has only sent pending or
4714 * success responses, clean up
4715 */
4716 l2cap_move_done(chan);
4717 }
4718
4719 /* Other amp move states imply that the move
4720 * has already aborted
4721 */
4722 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
4723 break;
4724 }
4725}
4726
4727static void l2cap_logical_finish_create(struct l2cap_chan *chan,
4728 struct hci_chan *hchan)
4729{
4730 struct l2cap_conf_rsp rsp;
4731
4732 chan->hs_hchan = hchan;
4733 chan->hs_hcon->l2cap_data = chan->conn;
4734
4735 l2cap_send_efs_conf_rsp(chan, &rsp, chan->ident, 0);
4736
4737 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
4738 int err;
4739
4740 set_default_fcs(chan);
4741
4742 err = l2cap_ertm_init(chan);
4743 if (err < 0)
4744 l2cap_send_disconn_req(chan, -err);
4745 else
4746 l2cap_chan_ready(chan);
4747 }
4748}
4749
4750static void l2cap_logical_finish_move(struct l2cap_chan *chan,
4751 struct hci_chan *hchan)
4752{
4753 chan->hs_hcon = hchan->conn;
4754 chan->hs_hcon->l2cap_data = chan->conn;
4755
4756 BT_DBG("move_state %d", chan->move_state);
4757
4758 switch (chan->move_state) {
4759 case L2CAP_MOVE_WAIT_LOGICAL_COMP:
4760 /* Move confirm will be sent after a success
4761 * response is received
4762 */
4763 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
4764 break;
4765 case L2CAP_MOVE_WAIT_LOGICAL_CFM:
4766 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
4767 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
4768 } else if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
4769 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
4770 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
4771 } else if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) {
4772 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
4773 l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS);
4774 }
4775 break;
4776 default:
4777 /* Move was not in expected state, free the channel */
4778 __release_logical_link(chan);
4779
4780 chan->move_state = L2CAP_MOVE_STABLE;
4781 }
4782}
4783
4784/* Call with chan locked */
4785void l2cap_logical_cfm(struct l2cap_chan *chan, struct hci_chan *hchan,
4786 u8 status)
4787{
4788 BT_DBG("chan %p, hchan %p, status %d", chan, hchan, status);
4789
4790 if (status) {
4791 l2cap_logical_fail(chan);
4792 __release_logical_link(chan);
4793 return;
4794 }
4795
4796 if (chan->state != BT_CONNECTED) {
4797 /* Ignore logical link if channel is on BR/EDR */
4798 if (chan->local_amp_id != AMP_ID_BREDR)
4799 l2cap_logical_finish_create(chan, hchan);
4800 } else {
4801 l2cap_logical_finish_move(chan, hchan);
4802 }
4803}
4804
4805void l2cap_move_start(struct l2cap_chan *chan)
4806{
4807 BT_DBG("chan %p", chan);
4808
4809 if (chan->local_amp_id == AMP_ID_BREDR) {
4810 if (chan->chan_policy != BT_CHANNEL_POLICY_AMP_PREFERRED)
4811 return;
4812 chan->move_role = L2CAP_MOVE_ROLE_INITIATOR;
4813 chan->move_state = L2CAP_MOVE_WAIT_PREPARE;
4814 /* Placeholder - start physical link setup */
4815 } else {
4816 chan->move_role = L2CAP_MOVE_ROLE_INITIATOR;
4817 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
4818 chan->move_id = 0;
4819 l2cap_move_setup(chan);
4820 l2cap_send_move_chan_req(chan, 0);
4821 }
4822}
4823
4824static void l2cap_do_create(struct l2cap_chan *chan, int result,
4825 u8 local_amp_id, u8 remote_amp_id)
4826{
4827 BT_DBG("chan %p state %s %u -> %u", chan, state_to_string(chan->state),
4828 local_amp_id, remote_amp_id);
4829
4830 chan->fcs = L2CAP_FCS_NONE;
4831
4832 /* Outgoing channel on AMP */
4833 if (chan->state == BT_CONNECT) {
4834 if (result == L2CAP_CR_SUCCESS) {
4835 chan->local_amp_id = local_amp_id;
4836 l2cap_send_create_chan_req(chan, remote_amp_id);
4837 } else {
4838 /* Revert to BR/EDR connect */
4839 l2cap_send_conn_req(chan);
4840 }
4841
4842 return;
4843 }
4844
4845 /* Incoming channel on AMP */
4846 if (__l2cap_no_conn_pending(chan)) {
4847 struct l2cap_conn_rsp rsp;
4848 char buf[128];
4849 rsp.scid = cpu_to_le16(chan->dcid);
4850 rsp.dcid = cpu_to_le16(chan->scid);
4851
4852 if (result == L2CAP_CR_SUCCESS) {
4853 /* Send successful response */
4854 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
4855 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
4856 } else {
4857 /* Send negative response */
4858 rsp.result = cpu_to_le16(L2CAP_CR_NO_MEM);
4859 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
4860 }
4861
4862 l2cap_send_cmd(chan->conn, chan->ident, L2CAP_CREATE_CHAN_RSP,
4863 sizeof(rsp), &rsp);
4864
4865 if (result == L2CAP_CR_SUCCESS) {
4866 l2cap_state_change(chan, BT_CONFIG);
4867 set_bit(CONF_REQ_SENT, &chan->conf_state);
4868 l2cap_send_cmd(chan->conn, l2cap_get_ident(chan->conn),
4869 L2CAP_CONF_REQ,
4870 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4871 chan->num_conf_req++;
4872 }
4873 }
4874}
4875
4876static void l2cap_do_move_initiate(struct l2cap_chan *chan, u8 local_amp_id,
4877 u8 remote_amp_id)
4878{
4879 l2cap_move_setup(chan);
4880 chan->move_id = local_amp_id;
4881 chan->move_state = L2CAP_MOVE_WAIT_RSP;
4882
4883 l2cap_send_move_chan_req(chan, remote_amp_id);
4884}
4885
4886static void l2cap_do_move_respond(struct l2cap_chan *chan, int result)
4887{
4888 struct hci_chan *hchan = NULL;
4889
4890 /* Placeholder - get hci_chan for logical link */
4891
4892 if (hchan) {
4893 if (hchan->state == BT_CONNECTED) {
4894 /* Logical link is ready to go */
4895 chan->hs_hcon = hchan->conn;
4896 chan->hs_hcon->l2cap_data = chan->conn;
4897 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
4898 l2cap_send_move_chan_rsp(chan, L2CAP_MR_SUCCESS);
4899
4900 l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
4901 } else {
4902 /* Wait for logical link to be ready */
4903 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
4904 }
4905 } else {
4906 /* Logical link not available */
4907 l2cap_send_move_chan_rsp(chan, L2CAP_MR_NOT_ALLOWED);
4908 }
4909}
4910
4911static void l2cap_do_move_cancel(struct l2cap_chan *chan, int result)
4912{
4913 if (chan->move_role == L2CAP_MOVE_ROLE_RESPONDER) {
4914 u8 rsp_result;
4915 if (result == -EINVAL)
4916 rsp_result = L2CAP_MR_BAD_ID;
4917 else
4918 rsp_result = L2CAP_MR_NOT_ALLOWED;
4919
4920 l2cap_send_move_chan_rsp(chan, rsp_result);
4921 }
4922
4923 chan->move_role = L2CAP_MOVE_ROLE_NONE;
4924 chan->move_state = L2CAP_MOVE_STABLE;
4925
4926 /* Restart data transmission */
4927 l2cap_ertm_send(chan);
4928}
4929
4930/* Invoke with locked chan */
4931void __l2cap_physical_cfm(struct l2cap_chan *chan, int result)
4932{
4933 u8 local_amp_id = chan->local_amp_id;
4934 u8 remote_amp_id = chan->remote_amp_id;
4935
4936 BT_DBG("chan %p, result %d, local_amp_id %d, remote_amp_id %d",
4937 chan, result, local_amp_id, remote_amp_id);
4938
4939 if (chan->state == BT_DISCONN || chan->state == BT_CLOSED) {
4940 l2cap_chan_unlock(chan);
4941 return;
4942 }
4943
4944 if (chan->state != BT_CONNECTED) {
4945 l2cap_do_create(chan, result, local_amp_id, remote_amp_id);
4946 } else if (result != L2CAP_MR_SUCCESS) {
4947 l2cap_do_move_cancel(chan, result);
4948 } else {
4949 switch (chan->move_role) {
4950 case L2CAP_MOVE_ROLE_INITIATOR:
4951 l2cap_do_move_initiate(chan, local_amp_id,
4952 remote_amp_id);
4953 break;
4954 case L2CAP_MOVE_ROLE_RESPONDER:
4955 l2cap_do_move_respond(chan, result);
4956 break;
4957 default:
4958 l2cap_do_move_cancel(chan, result);
4959 break;
4960 }
4961 }
4962}
4963
4964static inline int l2cap_move_channel_req(struct l2cap_conn *conn,
4965 struct l2cap_cmd_hdr *cmd,
4966 u16 cmd_len, void *data)
4967{
4968 struct l2cap_move_chan_req *req = data;
4969 struct l2cap_move_chan_rsp rsp;
4970 struct l2cap_chan *chan;
4971 u16 icid = 0;
4972 u16 result = L2CAP_MR_NOT_ALLOWED;
4973
4974 if (cmd_len != sizeof(*req))
4975 return -EPROTO;
4976
4977 icid = le16_to_cpu(req->icid);
4978
4979 BT_DBG("icid 0x%4.4x, dest_amp_id %d", icid, req->dest_amp_id);
4980
4981 if (!(conn->local_fixed_chan & L2CAP_FC_A2MP))
4982 return -EINVAL;
4983
4984 chan = l2cap_get_chan_by_dcid(conn, icid);
4985 if (!chan) {
4986 rsp.icid = cpu_to_le16(icid);
4987 rsp.result = cpu_to_le16(L2CAP_MR_NOT_ALLOWED);
4988 l2cap_send_cmd(conn, cmd->ident, L2CAP_MOVE_CHAN_RSP,
4989 sizeof(rsp), &rsp);
4990 return 0;
4991 }
4992
4993 chan->ident = cmd->ident;
4994
4995 if (chan->scid < L2CAP_CID_DYN_START ||
4996 chan->chan_policy == BT_CHANNEL_POLICY_BREDR_ONLY ||
4997 (chan->mode != L2CAP_MODE_ERTM &&
4998 chan->mode != L2CAP_MODE_STREAMING)) {
4999 result = L2CAP_MR_NOT_ALLOWED;
5000 goto send_move_response;
5001 }
5002
5003 if (chan->local_amp_id == req->dest_amp_id) {
5004 result = L2CAP_MR_SAME_ID;
5005 goto send_move_response;
5006 }
5007
5008 if (req->dest_amp_id != AMP_ID_BREDR) {
5009 struct hci_dev *hdev;
5010 hdev = hci_dev_get(req->dest_amp_id);
5011 if (!hdev || hdev->dev_type != HCI_AMP ||
5012 !test_bit(HCI_UP, &hdev->flags)) {
5013 if (hdev)
5014 hci_dev_put(hdev);
5015
5016 result = L2CAP_MR_BAD_ID;
5017 goto send_move_response;
5018 }
5019 hci_dev_put(hdev);
5020 }
5021
5022 /* Detect a move collision. Only send a collision response
5023 * if this side has "lost", otherwise proceed with the move.
5024 * The winner has the larger bd_addr.
5025 */
5026 if ((__chan_is_moving(chan) ||
5027 chan->move_role != L2CAP_MOVE_ROLE_NONE) &&
5028 bacmp(&conn->hcon->src, &conn->hcon->dst) > 0) {
5029 result = L2CAP_MR_COLLISION;
5030 goto send_move_response;
5031 }
5032
5033 chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
5034 l2cap_move_setup(chan);
5035 chan->move_id = req->dest_amp_id;
5036 icid = chan->dcid;
5037
5038 if (req->dest_amp_id == AMP_ID_BREDR) {
5039 /* Moving to BR/EDR */
5040 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5041 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
5042 result = L2CAP_MR_PEND;
5043 } else {
5044 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM;
5045 result = L2CAP_MR_SUCCESS;
5046 }
5047 } else {
5048 chan->move_state = L2CAP_MOVE_WAIT_PREPARE;
5049 /* Placeholder - uncomment when amp functions are available */
5050 /*amp_accept_physical(chan, req->dest_amp_id);*/
5051 result = L2CAP_MR_PEND;
5052 }
5053
5054send_move_response:
5055 l2cap_send_move_chan_rsp(chan, result);
5056
5057 l2cap_chan_unlock(chan);
5058
5059 return 0;
5060}
5061
5062static void l2cap_move_continue(struct l2cap_conn *conn, u16 icid, u16 result)
5063{
5064 struct l2cap_chan *chan;
5065 struct hci_chan *hchan = NULL;
5066
5067 chan = l2cap_get_chan_by_scid(conn, icid);
5068 if (!chan) {
5069 l2cap_send_move_chan_cfm_icid(conn, icid);
5070 return;
5071 }
5072
5073 __clear_chan_timer(chan);
5074 if (result == L2CAP_MR_PEND)
5075 __set_chan_timer(chan, L2CAP_MOVE_ERTX_TIMEOUT);
5076
5077 switch (chan->move_state) {
5078 case L2CAP_MOVE_WAIT_LOGICAL_COMP:
5079 /* Move confirm will be sent when logical link
5080 * is complete.
5081 */
5082 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
5083 break;
5084 case L2CAP_MOVE_WAIT_RSP_SUCCESS:
5085 if (result == L2CAP_MR_PEND) {
5086 break;
5087 } else if (test_bit(CONN_LOCAL_BUSY,
5088 &chan->conn_state)) {
5089 chan->move_state = L2CAP_MOVE_WAIT_LOCAL_BUSY;
5090 } else {
5091 /* Logical link is up or moving to BR/EDR,
5092 * proceed with move
5093 */
5094 chan->move_state = L2CAP_MOVE_WAIT_CONFIRM_RSP;
5095 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
5096 }
5097 break;
5098 case L2CAP_MOVE_WAIT_RSP:
5099 /* Moving to AMP */
5100 if (result == L2CAP_MR_SUCCESS) {
5101 /* Remote is ready, send confirm immediately
5102 * after logical link is ready
5103 */
5104 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_CFM;
5105 } else {
5106 /* Both logical link and move success
5107 * are required to confirm
5108 */
5109 chan->move_state = L2CAP_MOVE_WAIT_LOGICAL_COMP;
5110 }
5111
5112 /* Placeholder - get hci_chan for logical link */
5113 if (!hchan) {
5114 /* Logical link not available */
5115 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5116 break;
5117 }
5118
5119 /* If the logical link is not yet connected, do not
5120 * send confirmation.
5121 */
5122 if (hchan->state != BT_CONNECTED)
5123 break;
5124
5125 /* Logical link is already ready to go */
5126
5127 chan->hs_hcon = hchan->conn;
5128 chan->hs_hcon->l2cap_data = chan->conn;
5129
5130 if (result == L2CAP_MR_SUCCESS) {
5131 /* Can confirm now */
5132 l2cap_send_move_chan_cfm(chan, L2CAP_MC_CONFIRMED);
5133 } else {
5134 /* Now only need move success
5135 * to confirm
5136 */
5137 chan->move_state = L2CAP_MOVE_WAIT_RSP_SUCCESS;
5138 }
5139
5140 l2cap_logical_cfm(chan, hchan, L2CAP_MR_SUCCESS);
5141 break;
5142 default:
5143 /* Any other amp move state means the move failed. */
5144 chan->move_id = chan->local_amp_id;
5145 l2cap_move_done(chan);
5146 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5147 }
5148
5149 l2cap_chan_unlock(chan);
5150}
5151
5152static void l2cap_move_fail(struct l2cap_conn *conn, u8 ident, u16 icid,
5153 u16 result)
5154{
5155 struct l2cap_chan *chan;
5156
5157 chan = l2cap_get_chan_by_ident(conn, ident);
5158 if (!chan) {
5159 /* Could not locate channel, icid is best guess */
5160 l2cap_send_move_chan_cfm_icid(conn, icid);
5161 return;
5162 }
5163
5164 __clear_chan_timer(chan);
5165
5166 if (chan->move_role == L2CAP_MOVE_ROLE_INITIATOR) {
5167 if (result == L2CAP_MR_COLLISION) {
5168 chan->move_role = L2CAP_MOVE_ROLE_RESPONDER;
5169 } else {
5170 /* Cleanup - cancel move */
5171 chan->move_id = chan->local_amp_id;
5172 l2cap_move_done(chan);
5173 }
5174 }
5175
5176 l2cap_send_move_chan_cfm(chan, L2CAP_MC_UNCONFIRMED);
5177
5178 l2cap_chan_unlock(chan);
5179}
5180
5181static int l2cap_move_channel_rsp(struct l2cap_conn *conn,
5182 struct l2cap_cmd_hdr *cmd,
5183 u16 cmd_len, void *data)
5184{
5185 struct l2cap_move_chan_rsp *rsp = data;
5186 u16 icid, result;
5187
5188 if (cmd_len != sizeof(*rsp))
5189 return -EPROTO;
5190
5191 icid = le16_to_cpu(rsp->icid);
5192 result = le16_to_cpu(rsp->result);
5193
5194 BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
5195
5196 if (result == L2CAP_MR_SUCCESS || result == L2CAP_MR_PEND)
5197 l2cap_move_continue(conn, icid, result);
5198 else
5199 l2cap_move_fail(conn, cmd->ident, icid, result);
5200
5201 return 0;
5202}
5203
5204static int l2cap_move_channel_confirm(struct l2cap_conn *conn,
5205 struct l2cap_cmd_hdr *cmd,
5206 u16 cmd_len, void *data)
5207{
5208 struct l2cap_move_chan_cfm *cfm = data;
5209 struct l2cap_chan *chan;
5210 u16 icid, result;
5211
5212 if (cmd_len != sizeof(*cfm))
5213 return -EPROTO;
5214
5215 icid = le16_to_cpu(cfm->icid);
5216 result = le16_to_cpu(cfm->result);
5217
5218 BT_DBG("icid 0x%4.4x, result 0x%4.4x", icid, result);
5219
5220 chan = l2cap_get_chan_by_dcid(conn, icid);
5221 if (!chan) {
5222 /* Spec requires a response even if the icid was not found */
5223 l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
5224 return 0;
5225 }
5226
5227 if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM) {
5228 if (result == L2CAP_MC_CONFIRMED) {
5229 chan->local_amp_id = chan->move_id;
5230 if (chan->local_amp_id == AMP_ID_BREDR)
5231 __release_logical_link(chan);
5232 } else {
5233 chan->move_id = chan->local_amp_id;
5234 }
5235
5236 l2cap_move_done(chan);
5237 }
5238
5239 l2cap_send_move_chan_cfm_rsp(conn, cmd->ident, icid);
5240
5241 l2cap_chan_unlock(chan);
5242
5243 return 0;
5244}
5245
5246static inline int l2cap_move_channel_confirm_rsp(struct l2cap_conn *conn,
5247 struct l2cap_cmd_hdr *cmd,
5248 u16 cmd_len, void *data)
5249{
5250 struct l2cap_move_chan_cfm_rsp *rsp = data;
5251 struct l2cap_chan *chan;
5252 u16 icid;
5253
5254 if (cmd_len != sizeof(*rsp))
5255 return -EPROTO;
5256
5257 icid = le16_to_cpu(rsp->icid);
5258
5259 BT_DBG("icid 0x%4.4x", icid);
5260
5261 chan = l2cap_get_chan_by_scid(conn, icid);
5262 if (!chan)
5263 return 0;
5264
5265 __clear_chan_timer(chan);
5266
5267 if (chan->move_state == L2CAP_MOVE_WAIT_CONFIRM_RSP) {
5268 chan->local_amp_id = chan->move_id;
5269
5270 if (chan->local_amp_id == AMP_ID_BREDR && chan->hs_hchan)
5271 __release_logical_link(chan);
5272
5273 l2cap_move_done(chan);
5274 }
5275
5276 l2cap_chan_unlock(chan);
5277
5278 return 0;
5279}
5280
5281static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
5282 struct l2cap_cmd_hdr *cmd,
5283 u16 cmd_len, u8 *data)
5284{
5285 struct hci_conn *hcon = conn->hcon;
5286 struct l2cap_conn_param_update_req *req;
5287 struct l2cap_conn_param_update_rsp rsp;
5288 u16 min, max, latency, to_multiplier;
5289 int err;
5290
5291 if (hcon->role != HCI_ROLE_MASTER)
5292 return -EINVAL;
5293
5294 if (cmd_len != sizeof(struct l2cap_conn_param_update_req))
5295 return -EPROTO;
5296
5297 req = (struct l2cap_conn_param_update_req *) data;
5298 min = __le16_to_cpu(req->min);
5299 max = __le16_to_cpu(req->max);
5300 latency = __le16_to_cpu(req->latency);
5301 to_multiplier = __le16_to_cpu(req->to_multiplier);
5302
5303 BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x",
5304 min, max, latency, to_multiplier);
5305
5306 memset(&rsp, 0, sizeof(rsp));
5307
5308 err = hci_check_conn_params(min, max, latency, to_multiplier);
5309 if (err)
5310 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
5311 else
5312 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED);
5313
5314 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP,
5315 sizeof(rsp), &rsp);
5316
5317 if (!err) {
5318 u8 store_hint;
5319
5320 store_hint = hci_le_conn_update(hcon, min, max, latency,
5321 to_multiplier);
5322 mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type,
5323 store_hint, min, max, latency,
5324 to_multiplier);
5325
5326 }
5327
5328 return 0;
5329}
5330
5331static int l2cap_le_connect_rsp(struct l2cap_conn *conn,
5332 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5333 u8 *data)
5334{
5335 struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data;
5336 struct hci_conn *hcon = conn->hcon;
5337 u16 dcid, mtu, mps, credits, result;
5338 struct l2cap_chan *chan;
5339 int err, sec_level;
5340
5341 if (cmd_len < sizeof(*rsp))
5342 return -EPROTO;
5343
5344 dcid = __le16_to_cpu(rsp->dcid);
5345 mtu = __le16_to_cpu(rsp->mtu);
5346 mps = __le16_to_cpu(rsp->mps);
5347 credits = __le16_to_cpu(rsp->credits);
5348 result = __le16_to_cpu(rsp->result);
5349
5350 if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 ||
5351 dcid < L2CAP_CID_DYN_START ||
5352 dcid > L2CAP_CID_LE_DYN_END))
5353 return -EPROTO;
5354
5355 BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x",
5356 dcid, mtu, mps, credits, result);
5357
5358 mutex_lock(&conn->chan_lock);
5359
5360 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
5361 if (!chan) {
5362 err = -EBADSLT;
5363 goto unlock;
5364 }
5365
5366 err = 0;
5367
5368 l2cap_chan_lock(chan);
5369
5370 switch (result) {
5371 case L2CAP_CR_LE_SUCCESS:
5372 if (__l2cap_get_chan_by_dcid(conn, dcid)) {
5373 err = -EBADSLT;
5374 break;
5375 }
5376
5377 chan->ident = 0;
5378 chan->dcid = dcid;
5379 chan->omtu = mtu;
5380 chan->remote_mps = mps;
5381 chan->tx_credits = credits;
5382 l2cap_chan_ready(chan);
5383 break;
5384
5385 case L2CAP_CR_LE_AUTHENTICATION:
5386 case L2CAP_CR_LE_ENCRYPTION:
5387 /* If we already have MITM protection we can't do
5388 * anything.
5389 */
5390 if (hcon->sec_level > BT_SECURITY_MEDIUM) {
5391 l2cap_chan_del(chan, ECONNREFUSED);
5392 break;
5393 }
5394
5395 sec_level = hcon->sec_level + 1;
5396 if (chan->sec_level < sec_level)
5397 chan->sec_level = sec_level;
5398
5399 /* We'll need to send a new Connect Request */
5400 clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags);
5401
5402 smp_conn_security(hcon, chan->sec_level);
5403 break;
5404
5405 default:
5406 l2cap_chan_del(chan, ECONNREFUSED);
5407 break;
5408 }
5409
5410 l2cap_chan_unlock(chan);
5411
5412unlock:
5413 mutex_unlock(&conn->chan_lock);
5414
5415 return err;
5416}
5417
5418static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
5419 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5420 u8 *data)
5421{
5422 int err = 0;
5423
5424 switch (cmd->code) {
5425 case L2CAP_COMMAND_REJ:
5426 l2cap_command_rej(conn, cmd, cmd_len, data);
5427 break;
5428
5429 case L2CAP_CONN_REQ:
5430 err = l2cap_connect_req(conn, cmd, cmd_len, data);
5431 break;
5432
5433 case L2CAP_CONN_RSP:
5434 case L2CAP_CREATE_CHAN_RSP:
5435 l2cap_connect_create_rsp(conn, cmd, cmd_len, data);
5436 break;
5437
5438 case L2CAP_CONF_REQ:
5439 err = l2cap_config_req(conn, cmd, cmd_len, data);
5440 break;
5441
5442 case L2CAP_CONF_RSP:
5443 l2cap_config_rsp(conn, cmd, cmd_len, data);
5444 break;
5445
5446 case L2CAP_DISCONN_REQ:
5447 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
5448 break;
5449
5450 case L2CAP_DISCONN_RSP:
5451 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
5452 break;
5453
5454 case L2CAP_ECHO_REQ:
5455 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data);
5456 break;
5457
5458 case L2CAP_ECHO_RSP:
5459 break;
5460
5461 case L2CAP_INFO_REQ:
5462 err = l2cap_information_req(conn, cmd, cmd_len, data);
5463 break;
5464
5465 case L2CAP_INFO_RSP:
5466 l2cap_information_rsp(conn, cmd, cmd_len, data);
5467 break;
5468
5469 case L2CAP_CREATE_CHAN_REQ:
5470 err = l2cap_create_channel_req(conn, cmd, cmd_len, data);
5471 break;
5472
5473 case L2CAP_MOVE_CHAN_REQ:
5474 err = l2cap_move_channel_req(conn, cmd, cmd_len, data);
5475 break;
5476
5477 case L2CAP_MOVE_CHAN_RSP:
5478 l2cap_move_channel_rsp(conn, cmd, cmd_len, data);
5479 break;
5480
5481 case L2CAP_MOVE_CHAN_CFM:
5482 err = l2cap_move_channel_confirm(conn, cmd, cmd_len, data);
5483 break;
5484
5485 case L2CAP_MOVE_CHAN_CFM_RSP:
5486 l2cap_move_channel_confirm_rsp(conn, cmd, cmd_len, data);
5487 break;
5488
5489 default:
5490 BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code);
5491 err = -EINVAL;
5492 break;
5493 }
5494
5495 return err;
5496}
5497
5498static int l2cap_le_connect_req(struct l2cap_conn *conn,
5499 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5500 u8 *data)
5501{
5502 struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data;
5503 struct l2cap_le_conn_rsp rsp;
5504 struct l2cap_chan *chan, *pchan;
5505 u16 dcid, scid, credits, mtu, mps;
5506 __le16 psm;
5507 u8 result;
5508
5509 if (cmd_len != sizeof(*req))
5510 return -EPROTO;
5511
5512 scid = __le16_to_cpu(req->scid);
5513 mtu = __le16_to_cpu(req->mtu);
5514 mps = __le16_to_cpu(req->mps);
5515 psm = req->psm;
5516 dcid = 0;
5517 credits = 0;
5518
5519 if (mtu < 23 || mps < 23)
5520 return -EPROTO;
5521
5522 BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
5523 scid, mtu, mps);
5524
5525 /* Check if we have socket listening on psm */
5526 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
5527 &conn->hcon->dst, LE_LINK);
5528 if (!pchan) {
5529 result = L2CAP_CR_LE_BAD_PSM;
5530 chan = NULL;
5531 goto response;
5532 }
5533
5534 mutex_lock(&conn->chan_lock);
5535 l2cap_chan_lock(pchan);
5536
5537 if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
5538 SMP_ALLOW_STK)) {
5539 result = L2CAP_CR_LE_AUTHENTICATION;
5540 chan = NULL;
5541 goto response_unlock;
5542 }
5543
5544 /* Check for valid dynamic CID range */
5545 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
5546 result = L2CAP_CR_LE_INVALID_SCID;
5547 chan = NULL;
5548 goto response_unlock;
5549 }
5550
5551 /* Check if we already have channel with that dcid */
5552 if (__l2cap_get_chan_by_dcid(conn, scid)) {
5553 result = L2CAP_CR_LE_SCID_IN_USE;
5554 chan = NULL;
5555 goto response_unlock;
5556 }
5557
5558 chan = pchan->ops->new_connection(pchan);
5559 if (!chan) {
5560 result = L2CAP_CR_LE_NO_MEM;
5561 goto response_unlock;
5562 }
5563
5564 bacpy(&chan->src, &conn->hcon->src);
5565 bacpy(&chan->dst, &conn->hcon->dst);
5566 chan->src_type = bdaddr_src_type(conn->hcon);
5567 chan->dst_type = bdaddr_dst_type(conn->hcon);
5568 chan->psm = psm;
5569 chan->dcid = scid;
5570 chan->omtu = mtu;
5571 chan->remote_mps = mps;
5572
5573 __l2cap_chan_add(conn, chan);
5574
5575 l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits));
5576
5577 dcid = chan->scid;
5578 credits = chan->rx_credits;
5579
5580 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
5581
5582 chan->ident = cmd->ident;
5583
5584 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
5585 l2cap_state_change(chan, BT_CONNECT2);
5586 /* The following result value is actually not defined
5587 * for LE CoC but we use it to let the function know
5588 * that it should bail out after doing its cleanup
5589 * instead of sending a response.
5590 */
5591 result = L2CAP_CR_PEND;
5592 chan->ops->defer(chan);
5593 } else {
5594 l2cap_chan_ready(chan);
5595 result = L2CAP_CR_LE_SUCCESS;
5596 }
5597
5598response_unlock:
5599 l2cap_chan_unlock(pchan);
5600 mutex_unlock(&conn->chan_lock);
5601 l2cap_chan_put(pchan);
5602
5603 if (result == L2CAP_CR_PEND)
5604 return 0;
5605
5606response:
5607 if (chan) {
5608 rsp.mtu = cpu_to_le16(chan->imtu);
5609 rsp.mps = cpu_to_le16(chan->mps);
5610 } else {
5611 rsp.mtu = 0;
5612 rsp.mps = 0;
5613 }
5614
5615 rsp.dcid = cpu_to_le16(dcid);
5616 rsp.credits = cpu_to_le16(credits);
5617 rsp.result = cpu_to_le16(result);
5618
5619 l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp);
5620
5621 return 0;
5622}
5623
5624static inline int l2cap_le_credits(struct l2cap_conn *conn,
5625 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5626 u8 *data)
5627{
5628 struct l2cap_le_credits *pkt;
5629 struct l2cap_chan *chan;
5630 u16 cid, credits, max_credits;
5631
5632 if (cmd_len != sizeof(*pkt))
5633 return -EPROTO;
5634
5635 pkt = (struct l2cap_le_credits *) data;
5636 cid = __le16_to_cpu(pkt->cid);
5637 credits = __le16_to_cpu(pkt->credits);
5638
5639 BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits);
5640
5641 chan = l2cap_get_chan_by_dcid(conn, cid);
5642 if (!chan)
5643 return -EBADSLT;
5644
5645 max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits;
5646 if (credits > max_credits) {
5647 BT_ERR("LE credits overflow");
5648 l2cap_send_disconn_req(chan, ECONNRESET);
5649 l2cap_chan_unlock(chan);
5650
5651 /* Return 0 so that we don't trigger an unnecessary
5652 * command reject packet.
5653 */
5654 return 0;
5655 }
5656
5657 chan->tx_credits += credits;
5658
5659 /* Resume sending */
5660 l2cap_le_flowctl_send(chan);
5661
5662 if (chan->tx_credits)
5663 chan->ops->resume(chan);
5664
5665 l2cap_chan_unlock(chan);
5666
5667 return 0;
5668}
5669
5670static inline int l2cap_le_command_rej(struct l2cap_conn *conn,
5671 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5672 u8 *data)
5673{
5674 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
5675 struct l2cap_chan *chan;
5676
5677 if (cmd_len < sizeof(*rej))
5678 return -EPROTO;
5679
5680 mutex_lock(&conn->chan_lock);
5681
5682 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
5683 if (!chan)
5684 goto done;
5685
5686 l2cap_chan_lock(chan);
5687 l2cap_chan_del(chan, ECONNREFUSED);
5688 l2cap_chan_unlock(chan);
5689
5690done:
5691 mutex_unlock(&conn->chan_lock);
5692 return 0;
5693}
5694
5695static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
5696 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5697 u8 *data)
5698{
5699 int err = 0;
5700
5701 switch (cmd->code) {
5702 case L2CAP_COMMAND_REJ:
5703 l2cap_le_command_rej(conn, cmd, cmd_len, data);
5704 break;
5705
5706 case L2CAP_CONN_PARAM_UPDATE_REQ:
5707 err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data);
5708 break;
5709
5710 case L2CAP_CONN_PARAM_UPDATE_RSP:
5711 break;
5712
5713 case L2CAP_LE_CONN_RSP:
5714 l2cap_le_connect_rsp(conn, cmd, cmd_len, data);
5715 break;
5716
5717 case L2CAP_LE_CONN_REQ:
5718 err = l2cap_le_connect_req(conn, cmd, cmd_len, data);
5719 break;
5720
5721 case L2CAP_LE_CREDITS:
5722 err = l2cap_le_credits(conn, cmd, cmd_len, data);
5723 break;
5724
5725 case L2CAP_DISCONN_REQ:
5726 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
5727 break;
5728
5729 case L2CAP_DISCONN_RSP:
5730 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
5731 break;
5732
5733 default:
5734 BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code);
5735 err = -EINVAL;
5736 break;
5737 }
5738
5739 return err;
5740}
5741
5742static inline void l2cap_le_sig_channel(struct l2cap_conn *conn,
5743 struct sk_buff *skb)
5744{
5745 struct hci_conn *hcon = conn->hcon;
5746 struct l2cap_cmd_hdr *cmd;
5747 u16 len;
5748 int err;
5749
5750 if (hcon->type != LE_LINK)
5751 goto drop;
5752
5753 if (skb->len < L2CAP_CMD_HDR_SIZE)
5754 goto drop;
5755
5756 cmd = (void *) skb->data;
5757 skb_pull(skb, L2CAP_CMD_HDR_SIZE);
5758
5759 len = le16_to_cpu(cmd->len);
5760
5761 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident);
5762
5763 if (len != skb->len || !cmd->ident) {
5764 BT_DBG("corrupted command");
5765 goto drop;
5766 }
5767
5768 err = l2cap_le_sig_cmd(conn, cmd, len, skb->data);
5769 if (err) {
5770 struct l2cap_cmd_rej_unk rej;
5771
5772 BT_ERR("Wrong link type (%d)", err);
5773
5774 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
5775 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ,
5776 sizeof(rej), &rej);
5777 }
5778
5779drop:
5780 kfree_skb(skb);
5781}
5782
5783static inline void l2cap_sig_channel(struct l2cap_conn *conn,
5784 struct sk_buff *skb)
5785{
5786 struct hci_conn *hcon = conn->hcon;
5787 u8 *data = skb->data;
5788 int len = skb->len;
5789 struct l2cap_cmd_hdr cmd;
5790 int err;
5791
5792 l2cap_raw_recv(conn, skb);
5793
5794 if (hcon->type != ACL_LINK)
5795 goto drop;
5796
5797 while (len >= L2CAP_CMD_HDR_SIZE) {
5798 u16 cmd_len;
5799 memcpy(&cmd, data, L2CAP_CMD_HDR_SIZE);
5800 data += L2CAP_CMD_HDR_SIZE;
5801 len -= L2CAP_CMD_HDR_SIZE;
5802
5803 cmd_len = le16_to_cpu(cmd.len);
5804
5805 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd.code, cmd_len,
5806 cmd.ident);
5807
5808 if (cmd_len > len || !cmd.ident) {
5809 BT_DBG("corrupted command");
5810 break;
5811 }
5812
5813 err = l2cap_bredr_sig_cmd(conn, &cmd, cmd_len, data);
5814 if (err) {
5815 struct l2cap_cmd_rej_unk rej;
5816
5817 BT_ERR("Wrong link type (%d)", err);
5818
5819 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
5820 l2cap_send_cmd(conn, cmd.ident, L2CAP_COMMAND_REJ,
5821 sizeof(rej), &rej);
5822 }
5823
5824 data += cmd_len;
5825 len -= cmd_len;
5826 }
5827
5828drop:
5829 kfree_skb(skb);
5830}
5831
5832static int l2cap_check_fcs(struct l2cap_chan *chan, struct sk_buff *skb)
5833{
5834 u16 our_fcs, rcv_fcs;
5835 int hdr_size;
5836
5837 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
5838 hdr_size = L2CAP_EXT_HDR_SIZE;
5839 else
5840 hdr_size = L2CAP_ENH_HDR_SIZE;
5841
5842 if (chan->fcs == L2CAP_FCS_CRC16) {
5843 skb_trim(skb, skb->len - L2CAP_FCS_SIZE);
5844 rcv_fcs = get_unaligned_le16(skb->data + skb->len);
5845 our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size);
5846
5847 if (our_fcs != rcv_fcs)
5848 return -EBADMSG;
5849 }
5850 return 0;
5851}
5852
5853static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan)
5854{
5855 struct l2cap_ctrl control;
5856
5857 BT_DBG("chan %p", chan);
5858
5859 memset(&control, 0, sizeof(control));
5860 control.sframe = 1;
5861 control.final = 1;
5862 control.reqseq = chan->buffer_seq;
5863 set_bit(CONN_SEND_FBIT, &chan->conn_state);
5864
5865 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5866 control.super = L2CAP_SUPER_RNR;
5867 l2cap_send_sframe(chan, &control);
5868 }
5869
5870 if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) &&
5871 chan->unacked_frames > 0)
5872 __set_retrans_timer(chan);
5873
5874 /* Send pending iframes */
5875 l2cap_ertm_send(chan);
5876
5877 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
5878 test_bit(CONN_SEND_FBIT, &chan->conn_state)) {
5879 /* F-bit wasn't sent in an s-frame or i-frame yet, so
5880 * send it now.
5881 */
5882 control.super = L2CAP_SUPER_RR;
5883 l2cap_send_sframe(chan, &control);
5884 }
5885}
5886
5887static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag,
5888 struct sk_buff **last_frag)
5889{
5890 /* skb->len reflects data in skb as well as all fragments
5891 * skb->data_len reflects only data in fragments
5892 */
5893 if (!skb_has_frag_list(skb))
5894 skb_shinfo(skb)->frag_list = new_frag;
5895
5896 new_frag->next = NULL;
5897
5898 (*last_frag)->next = new_frag;
5899 *last_frag = new_frag;
5900
5901 skb->len += new_frag->len;
5902 skb->data_len += new_frag->len;
5903 skb->truesize += new_frag->truesize;
5904}
5905
5906static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb,
5907 struct l2cap_ctrl *control)
5908{
5909 int err = -EINVAL;
5910
5911 switch (control->sar) {
5912 case L2CAP_SAR_UNSEGMENTED:
5913 if (chan->sdu)
5914 break;
5915
5916 err = chan->ops->recv(chan, skb);
5917 break;
5918
5919 case L2CAP_SAR_START:
5920 if (chan->sdu)
5921 break;
5922
5923 if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE))
5924 break;
5925
5926 chan->sdu_len = get_unaligned_le16(skb->data);
5927 skb_pull(skb, L2CAP_SDULEN_SIZE);
5928
5929 if (chan->sdu_len > chan->imtu) {
5930 err = -EMSGSIZE;
5931 break;
5932 }
5933
5934 if (skb->len >= chan->sdu_len)
5935 break;
5936
5937 chan->sdu = skb;
5938 chan->sdu_last_frag = skb;
5939
5940 skb = NULL;
5941 err = 0;
5942 break;
5943
5944 case L2CAP_SAR_CONTINUE:
5945 if (!chan->sdu)
5946 break;
5947
5948 append_skb_frag(chan->sdu, skb,
5949 &chan->sdu_last_frag);
5950 skb = NULL;
5951
5952 if (chan->sdu->len >= chan->sdu_len)
5953 break;
5954
5955 err = 0;
5956 break;
5957
5958 case L2CAP_SAR_END:
5959 if (!chan->sdu)
5960 break;
5961
5962 append_skb_frag(chan->sdu, skb,
5963 &chan->sdu_last_frag);
5964 skb = NULL;
5965
5966 if (chan->sdu->len != chan->sdu_len)
5967 break;
5968
5969 err = chan->ops->recv(chan, chan->sdu);
5970
5971 if (!err) {
5972 /* Reassembly complete */
5973 chan->sdu = NULL;
5974 chan->sdu_last_frag = NULL;
5975 chan->sdu_len = 0;
5976 }
5977 break;
5978 }
5979
5980 if (err) {
5981 kfree_skb(skb);
5982 kfree_skb(chan->sdu);
5983 chan->sdu = NULL;
5984 chan->sdu_last_frag = NULL;
5985 chan->sdu_len = 0;
5986 }
5987
5988 return err;
5989}
5990
5991static int l2cap_resegment(struct l2cap_chan *chan)
5992{
5993 /* Placeholder */
5994 return 0;
5995}
5996
5997void l2cap_chan_busy(struct l2cap_chan *chan, int busy)
5998{
5999 u8 event;
6000
6001 if (chan->mode != L2CAP_MODE_ERTM)
6002 return;
6003
6004 event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR;
6005 l2cap_tx(chan, NULL, NULL, event);
6006}
6007
6008static int l2cap_rx_queued_iframes(struct l2cap_chan *chan)
6009{
6010 int err = 0;
6011 /* Pass sequential frames to l2cap_reassemble_sdu()
6012 * until a gap is encountered.
6013 */
6014
6015 BT_DBG("chan %p", chan);
6016
6017 while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6018 struct sk_buff *skb;
6019 BT_DBG("Searching for skb with txseq %d (queue len %d)",
6020 chan->buffer_seq, skb_queue_len(&chan->srej_q));
6021
6022 skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq);
6023
6024 if (!skb)
6025 break;
6026
6027 skb_unlink(skb, &chan->srej_q);
6028 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
6029 err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap);
6030 if (err)
6031 break;
6032 }
6033
6034 if (skb_queue_empty(&chan->srej_q)) {
6035 chan->rx_state = L2CAP_RX_STATE_RECV;
6036 l2cap_send_ack(chan);
6037 }
6038
6039 return err;
6040}
6041
6042static void l2cap_handle_srej(struct l2cap_chan *chan,
6043 struct l2cap_ctrl *control)
6044{
6045 struct sk_buff *skb;
6046
6047 BT_DBG("chan %p, control %p", chan, control);
6048
6049 if (control->reqseq == chan->next_tx_seq) {
6050 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
6051 l2cap_send_disconn_req(chan, ECONNRESET);
6052 return;
6053 }
6054
6055 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
6056
6057 if (skb == NULL) {
6058 BT_DBG("Seq %d not available for retransmission",
6059 control->reqseq);
6060 return;
6061 }
6062
6063 if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) {
6064 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
6065 l2cap_send_disconn_req(chan, ECONNRESET);
6066 return;
6067 }
6068
6069 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6070
6071 if (control->poll) {
6072 l2cap_pass_to_tx(chan, control);
6073
6074 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6075 l2cap_retransmit(chan, control);
6076 l2cap_ertm_send(chan);
6077
6078 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
6079 set_bit(CONN_SREJ_ACT, &chan->conn_state);
6080 chan->srej_save_reqseq = control->reqseq;
6081 }
6082 } else {
6083 l2cap_pass_to_tx_fbit(chan, control);
6084
6085 if (control->final) {
6086 if (chan->srej_save_reqseq != control->reqseq ||
6087 !test_and_clear_bit(CONN_SREJ_ACT,
6088 &chan->conn_state))
6089 l2cap_retransmit(chan, control);
6090 } else {
6091 l2cap_retransmit(chan, control);
6092 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
6093 set_bit(CONN_SREJ_ACT, &chan->conn_state);
6094 chan->srej_save_reqseq = control->reqseq;
6095 }
6096 }
6097 }
6098}
6099
6100static void l2cap_handle_rej(struct l2cap_chan *chan,
6101 struct l2cap_ctrl *control)
6102{
6103 struct sk_buff *skb;
6104
6105 BT_DBG("chan %p, control %p", chan, control);
6106
6107 if (control->reqseq == chan->next_tx_seq) {
6108 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
6109 l2cap_send_disconn_req(chan, ECONNRESET);
6110 return;
6111 }
6112
6113 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
6114
6115 if (chan->max_tx && skb &&
6116 bt_cb(skb)->l2cap.retries >= chan->max_tx) {
6117 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
6118 l2cap_send_disconn_req(chan, ECONNRESET);
6119 return;
6120 }
6121
6122 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6123
6124 l2cap_pass_to_tx(chan, control);
6125
6126 if (control->final) {
6127 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state))
6128 l2cap_retransmit_all(chan, control);
6129 } else {
6130 l2cap_retransmit_all(chan, control);
6131 l2cap_ertm_send(chan);
6132 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F)
6133 set_bit(CONN_REJ_ACT, &chan->conn_state);
6134 }
6135}
6136
6137static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq)
6138{
6139 BT_DBG("chan %p, txseq %d", chan, txseq);
6140
6141 BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq,
6142 chan->expected_tx_seq);
6143
6144 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
6145 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
6146 chan->tx_win) {
6147 /* See notes below regarding "double poll" and
6148 * invalid packets.
6149 */
6150 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
6151 BT_DBG("Invalid/Ignore - after SREJ");
6152 return L2CAP_TXSEQ_INVALID_IGNORE;
6153 } else {
6154 BT_DBG("Invalid - in window after SREJ sent");
6155 return L2CAP_TXSEQ_INVALID;
6156 }
6157 }
6158
6159 if (chan->srej_list.head == txseq) {
6160 BT_DBG("Expected SREJ");
6161 return L2CAP_TXSEQ_EXPECTED_SREJ;
6162 }
6163
6164 if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) {
6165 BT_DBG("Duplicate SREJ - txseq already stored");
6166 return L2CAP_TXSEQ_DUPLICATE_SREJ;
6167 }
6168
6169 if (l2cap_seq_list_contains(&chan->srej_list, txseq)) {
6170 BT_DBG("Unexpected SREJ - not requested");
6171 return L2CAP_TXSEQ_UNEXPECTED_SREJ;
6172 }
6173 }
6174
6175 if (chan->expected_tx_seq == txseq) {
6176 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
6177 chan->tx_win) {
6178 BT_DBG("Invalid - txseq outside tx window");
6179 return L2CAP_TXSEQ_INVALID;
6180 } else {
6181 BT_DBG("Expected");
6182 return L2CAP_TXSEQ_EXPECTED;
6183 }
6184 }
6185
6186 if (__seq_offset(chan, txseq, chan->last_acked_seq) <
6187 __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) {
6188 BT_DBG("Duplicate - expected_tx_seq later than txseq");
6189 return L2CAP_TXSEQ_DUPLICATE;
6190 }
6191
6192 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) {
6193 /* A source of invalid packets is a "double poll" condition,
6194 * where delays cause us to send multiple poll packets. If
6195 * the remote stack receives and processes both polls,
6196 * sequence numbers can wrap around in such a way that a
6197 * resent frame has a sequence number that looks like new data
6198 * with a sequence gap. This would trigger an erroneous SREJ
6199 * request.
6200 *
6201 * Fortunately, this is impossible with a tx window that's
6202 * less than half of the maximum sequence number, which allows
6203 * invalid frames to be safely ignored.
6204 *
6205 * With tx window sizes greater than half of the tx window
6206 * maximum, the frame is invalid and cannot be ignored. This
6207 * causes a disconnect.
6208 */
6209
6210 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
6211 BT_DBG("Invalid/Ignore - txseq outside tx window");
6212 return L2CAP_TXSEQ_INVALID_IGNORE;
6213 } else {
6214 BT_DBG("Invalid - txseq outside tx window");
6215 return L2CAP_TXSEQ_INVALID;
6216 }
6217 } else {
6218 BT_DBG("Unexpected - txseq indicates missing frames");
6219 return L2CAP_TXSEQ_UNEXPECTED;
6220 }
6221}
6222
6223static int l2cap_rx_state_recv(struct l2cap_chan *chan,
6224 struct l2cap_ctrl *control,
6225 struct sk_buff *skb, u8 event)
6226{
6227 int err = 0;
6228 bool skb_in_use = false;
6229
6230 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6231 event);
6232
6233 switch (event) {
6234 case L2CAP_EV_RECV_IFRAME:
6235 switch (l2cap_classify_txseq(chan, control->txseq)) {
6236 case L2CAP_TXSEQ_EXPECTED:
6237 l2cap_pass_to_tx(chan, control);
6238
6239 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6240 BT_DBG("Busy, discarding expected seq %d",
6241 control->txseq);
6242 break;
6243 }
6244
6245 chan->expected_tx_seq = __next_seq(chan,
6246 control->txseq);
6247
6248 chan->buffer_seq = chan->expected_tx_seq;
6249 skb_in_use = true;
6250
6251 err = l2cap_reassemble_sdu(chan, skb, control);
6252 if (err)
6253 break;
6254
6255 if (control->final) {
6256 if (!test_and_clear_bit(CONN_REJ_ACT,
6257 &chan->conn_state)) {
6258 control->final = 0;
6259 l2cap_retransmit_all(chan, control);
6260 l2cap_ertm_send(chan);
6261 }
6262 }
6263
6264 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
6265 l2cap_send_ack(chan);
6266 break;
6267 case L2CAP_TXSEQ_UNEXPECTED:
6268 l2cap_pass_to_tx(chan, control);
6269
6270 /* Can't issue SREJ frames in the local busy state.
6271 * Drop this frame, it will be seen as missing
6272 * when local busy is exited.
6273 */
6274 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6275 BT_DBG("Busy, discarding unexpected seq %d",
6276 control->txseq);
6277 break;
6278 }
6279
6280 /* There was a gap in the sequence, so an SREJ
6281 * must be sent for each missing frame. The
6282 * current frame is stored for later use.
6283 */
6284 skb_queue_tail(&chan->srej_q, skb);
6285 skb_in_use = true;
6286 BT_DBG("Queued %p (queue len %d)", skb,
6287 skb_queue_len(&chan->srej_q));
6288
6289 clear_bit(CONN_SREJ_ACT, &chan->conn_state);
6290 l2cap_seq_list_clear(&chan->srej_list);
6291 l2cap_send_srej(chan, control->txseq);
6292
6293 chan->rx_state = L2CAP_RX_STATE_SREJ_SENT;
6294 break;
6295 case L2CAP_TXSEQ_DUPLICATE:
6296 l2cap_pass_to_tx(chan, control);
6297 break;
6298 case L2CAP_TXSEQ_INVALID_IGNORE:
6299 break;
6300 case L2CAP_TXSEQ_INVALID:
6301 default:
6302 l2cap_send_disconn_req(chan, ECONNRESET);
6303 break;
6304 }
6305 break;
6306 case L2CAP_EV_RECV_RR:
6307 l2cap_pass_to_tx(chan, control);
6308 if (control->final) {
6309 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6310
6311 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state) &&
6312 !__chan_is_moving(chan)) {
6313 control->final = 0;
6314 l2cap_retransmit_all(chan, control);
6315 }
6316
6317 l2cap_ertm_send(chan);
6318 } else if (control->poll) {
6319 l2cap_send_i_or_rr_or_rnr(chan);
6320 } else {
6321 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6322 &chan->conn_state) &&
6323 chan->unacked_frames)
6324 __set_retrans_timer(chan);
6325
6326 l2cap_ertm_send(chan);
6327 }
6328 break;
6329 case L2CAP_EV_RECV_RNR:
6330 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6331 l2cap_pass_to_tx(chan, control);
6332 if (control && control->poll) {
6333 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6334 l2cap_send_rr_or_rnr(chan, 0);
6335 }
6336 __clear_retrans_timer(chan);
6337 l2cap_seq_list_clear(&chan->retrans_list);
6338 break;
6339 case L2CAP_EV_RECV_REJ:
6340 l2cap_handle_rej(chan, control);
6341 break;
6342 case L2CAP_EV_RECV_SREJ:
6343 l2cap_handle_srej(chan, control);
6344 break;
6345 default:
6346 break;
6347 }
6348
6349 if (skb && !skb_in_use) {
6350 BT_DBG("Freeing %p", skb);
6351 kfree_skb(skb);
6352 }
6353
6354 return err;
6355}
6356
6357static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan,
6358 struct l2cap_ctrl *control,
6359 struct sk_buff *skb, u8 event)
6360{
6361 int err = 0;
6362 u16 txseq = control->txseq;
6363 bool skb_in_use = false;
6364
6365 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6366 event);
6367
6368 switch (event) {
6369 case L2CAP_EV_RECV_IFRAME:
6370 switch (l2cap_classify_txseq(chan, txseq)) {
6371 case L2CAP_TXSEQ_EXPECTED:
6372 /* Keep frame for reassembly later */
6373 l2cap_pass_to_tx(chan, control);
6374 skb_queue_tail(&chan->srej_q, skb);
6375 skb_in_use = true;
6376 BT_DBG("Queued %p (queue len %d)", skb,
6377 skb_queue_len(&chan->srej_q));
6378
6379 chan->expected_tx_seq = __next_seq(chan, txseq);
6380 break;
6381 case L2CAP_TXSEQ_EXPECTED_SREJ:
6382 l2cap_seq_list_pop(&chan->srej_list);
6383
6384 l2cap_pass_to_tx(chan, control);
6385 skb_queue_tail(&chan->srej_q, skb);
6386 skb_in_use = true;
6387 BT_DBG("Queued %p (queue len %d)", skb,
6388 skb_queue_len(&chan->srej_q));
6389
6390 err = l2cap_rx_queued_iframes(chan);
6391 if (err)
6392 break;
6393
6394 break;
6395 case L2CAP_TXSEQ_UNEXPECTED:
6396 /* Got a frame that can't be reassembled yet.
6397 * Save it for later, and send SREJs to cover
6398 * the missing frames.
6399 */
6400 skb_queue_tail(&chan->srej_q, skb);
6401 skb_in_use = true;
6402 BT_DBG("Queued %p (queue len %d)", skb,
6403 skb_queue_len(&chan->srej_q));
6404
6405 l2cap_pass_to_tx(chan, control);
6406 l2cap_send_srej(chan, control->txseq);
6407 break;
6408 case L2CAP_TXSEQ_UNEXPECTED_SREJ:
6409 /* This frame was requested with an SREJ, but
6410 * some expected retransmitted frames are
6411 * missing. Request retransmission of missing
6412 * SREJ'd frames.
6413 */
6414 skb_queue_tail(&chan->srej_q, skb);
6415 skb_in_use = true;
6416 BT_DBG("Queued %p (queue len %d)", skb,
6417 skb_queue_len(&chan->srej_q));
6418
6419 l2cap_pass_to_tx(chan, control);
6420 l2cap_send_srej_list(chan, control->txseq);
6421 break;
6422 case L2CAP_TXSEQ_DUPLICATE_SREJ:
6423 /* We've already queued this frame. Drop this copy. */
6424 l2cap_pass_to_tx(chan, control);
6425 break;
6426 case L2CAP_TXSEQ_DUPLICATE:
6427 /* Expecting a later sequence number, so this frame
6428 * was already received. Ignore it completely.
6429 */
6430 break;
6431 case L2CAP_TXSEQ_INVALID_IGNORE:
6432 break;
6433 case L2CAP_TXSEQ_INVALID:
6434 default:
6435 l2cap_send_disconn_req(chan, ECONNRESET);
6436 break;
6437 }
6438 break;
6439 case L2CAP_EV_RECV_RR:
6440 l2cap_pass_to_tx(chan, control);
6441 if (control->final) {
6442 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6443
6444 if (!test_and_clear_bit(CONN_REJ_ACT,
6445 &chan->conn_state)) {
6446 control->final = 0;
6447 l2cap_retransmit_all(chan, control);
6448 }
6449
6450 l2cap_ertm_send(chan);
6451 } else if (control->poll) {
6452 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6453 &chan->conn_state) &&
6454 chan->unacked_frames) {
6455 __set_retrans_timer(chan);
6456 }
6457
6458 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6459 l2cap_send_srej_tail(chan);
6460 } else {
6461 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6462 &chan->conn_state) &&
6463 chan->unacked_frames)
6464 __set_retrans_timer(chan);
6465
6466 l2cap_send_ack(chan);
6467 }
6468 break;
6469 case L2CAP_EV_RECV_RNR:
6470 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6471 l2cap_pass_to_tx(chan, control);
6472 if (control->poll) {
6473 l2cap_send_srej_tail(chan);
6474 } else {
6475 struct l2cap_ctrl rr_control;
6476 memset(&rr_control, 0, sizeof(rr_control));
6477 rr_control.sframe = 1;
6478 rr_control.super = L2CAP_SUPER_RR;
6479 rr_control.reqseq = chan->buffer_seq;
6480 l2cap_send_sframe(chan, &rr_control);
6481 }
6482
6483 break;
6484 case L2CAP_EV_RECV_REJ:
6485 l2cap_handle_rej(chan, control);
6486 break;
6487 case L2CAP_EV_RECV_SREJ:
6488 l2cap_handle_srej(chan, control);
6489 break;
6490 }
6491
6492 if (skb && !skb_in_use) {
6493 BT_DBG("Freeing %p", skb);
6494 kfree_skb(skb);
6495 }
6496
6497 return err;
6498}
6499
6500static int l2cap_finish_move(struct l2cap_chan *chan)
6501{
6502 BT_DBG("chan %p", chan);
6503
6504 chan->rx_state = L2CAP_RX_STATE_RECV;
6505
6506 if (chan->hs_hcon)
6507 chan->conn->mtu = chan->hs_hcon->hdev->block_mtu;
6508 else
6509 chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
6510
6511 return l2cap_resegment(chan);
6512}
6513
6514static int l2cap_rx_state_wait_p(struct l2cap_chan *chan,
6515 struct l2cap_ctrl *control,
6516 struct sk_buff *skb, u8 event)
6517{
6518 int err;
6519
6520 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6521 event);
6522
6523 if (!control->poll)
6524 return -EPROTO;
6525
6526 l2cap_process_reqseq(chan, control->reqseq);
6527
6528 if (!skb_queue_empty(&chan->tx_q))
6529 chan->tx_send_head = skb_peek(&chan->tx_q);
6530 else
6531 chan->tx_send_head = NULL;
6532
6533 /* Rewind next_tx_seq to the point expected
6534 * by the receiver.
6535 */
6536 chan->next_tx_seq = control->reqseq;
6537 chan->unacked_frames = 0;
6538
6539 err = l2cap_finish_move(chan);
6540 if (err)
6541 return err;
6542
6543 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6544 l2cap_send_i_or_rr_or_rnr(chan);
6545
6546 if (event == L2CAP_EV_RECV_IFRAME)
6547 return -EPROTO;
6548
6549 return l2cap_rx_state_recv(chan, control, NULL, event);
6550}
6551
6552static int l2cap_rx_state_wait_f(struct l2cap_chan *chan,
6553 struct l2cap_ctrl *control,
6554 struct sk_buff *skb, u8 event)
6555{
6556 int err;
6557
6558 if (!control->final)
6559 return -EPROTO;
6560
6561 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6562
6563 chan->rx_state = L2CAP_RX_STATE_RECV;
6564 l2cap_process_reqseq(chan, control->reqseq);
6565
6566 if (!skb_queue_empty(&chan->tx_q))
6567 chan->tx_send_head = skb_peek(&chan->tx_q);
6568 else
6569 chan->tx_send_head = NULL;
6570
6571 /* Rewind next_tx_seq to the point expected
6572 * by the receiver.
6573 */
6574 chan->next_tx_seq = control->reqseq;
6575 chan->unacked_frames = 0;
6576
6577 if (chan->hs_hcon)
6578 chan->conn->mtu = chan->hs_hcon->hdev->block_mtu;
6579 else
6580 chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
6581
6582 err = l2cap_resegment(chan);
6583
6584 if (!err)
6585 err = l2cap_rx_state_recv(chan, control, skb, event);
6586
6587 return err;
6588}
6589
6590static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq)
6591{
6592 /* Make sure reqseq is for a packet that has been sent but not acked */
6593 u16 unacked;
6594
6595 unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq);
6596 return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked;
6597}
6598
6599static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
6600 struct sk_buff *skb, u8 event)
6601{
6602 int err = 0;
6603
6604 BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan,
6605 control, skb, event, chan->rx_state);
6606
6607 if (__valid_reqseq(chan, control->reqseq)) {
6608 switch (chan->rx_state) {
6609 case L2CAP_RX_STATE_RECV:
6610 err = l2cap_rx_state_recv(chan, control, skb, event);
6611 break;
6612 case L2CAP_RX_STATE_SREJ_SENT:
6613 err = l2cap_rx_state_srej_sent(chan, control, skb,
6614 event);
6615 break;
6616 case L2CAP_RX_STATE_WAIT_P:
6617 err = l2cap_rx_state_wait_p(chan, control, skb, event);
6618 break;
6619 case L2CAP_RX_STATE_WAIT_F:
6620 err = l2cap_rx_state_wait_f(chan, control, skb, event);
6621 break;
6622 default:
6623 /* shut it down */
6624 break;
6625 }
6626 } else {
6627 BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d",
6628 control->reqseq, chan->next_tx_seq,
6629 chan->expected_ack_seq);
6630 l2cap_send_disconn_req(chan, ECONNRESET);
6631 }
6632
6633 return err;
6634}
6635
6636static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
6637 struct sk_buff *skb)
6638{
6639 BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb,
6640 chan->rx_state);
6641
6642 if (l2cap_classify_txseq(chan, control->txseq) ==
6643 L2CAP_TXSEQ_EXPECTED) {
6644 l2cap_pass_to_tx(chan, control);
6645
6646 BT_DBG("buffer_seq %d->%d", chan->buffer_seq,
6647 __next_seq(chan, chan->buffer_seq));
6648
6649 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
6650
6651 l2cap_reassemble_sdu(chan, skb, control);
6652 } else {
6653 if (chan->sdu) {
6654 kfree_skb(chan->sdu);
6655 chan->sdu = NULL;
6656 }
6657 chan->sdu_last_frag = NULL;
6658 chan->sdu_len = 0;
6659
6660 if (skb) {
6661 BT_DBG("Freeing %p", skb);
6662 kfree_skb(skb);
6663 }
6664 }
6665
6666 chan->last_acked_seq = control->txseq;
6667 chan->expected_tx_seq = __next_seq(chan, control->txseq);
6668
6669 return 0;
6670}
6671
6672static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
6673{
6674 struct l2cap_ctrl *control = &bt_cb(skb)->l2cap;
6675 u16 len;
6676 u8 event;
6677
6678 __unpack_control(chan, skb);
6679
6680 len = skb->len;
6681
6682 /*
6683 * We can just drop the corrupted I-frame here.
6684 * Receiver will miss it and start proper recovery
6685 * procedures and ask for retransmission.
6686 */
6687 if (l2cap_check_fcs(chan, skb))
6688 goto drop;
6689
6690 if (!control->sframe && control->sar == L2CAP_SAR_START)
6691 len -= L2CAP_SDULEN_SIZE;
6692
6693 if (chan->fcs == L2CAP_FCS_CRC16)
6694 len -= L2CAP_FCS_SIZE;
6695
6696 if (len > chan->mps) {
6697 l2cap_send_disconn_req(chan, ECONNRESET);
6698 goto drop;
6699 }
6700
6701 if ((chan->mode == L2CAP_MODE_ERTM ||
6702 chan->mode == L2CAP_MODE_STREAMING) && sk_filter(chan->data, skb))
6703 goto drop;
6704
6705 if (!control->sframe) {
6706 int err;
6707
6708 BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d",
6709 control->sar, control->reqseq, control->final,
6710 control->txseq);
6711
6712 /* Validate F-bit - F=0 always valid, F=1 only
6713 * valid in TX WAIT_F
6714 */
6715 if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F)
6716 goto drop;
6717
6718 if (chan->mode != L2CAP_MODE_STREAMING) {
6719 event = L2CAP_EV_RECV_IFRAME;
6720 err = l2cap_rx(chan, control, skb, event);
6721 } else {
6722 err = l2cap_stream_rx(chan, control, skb);
6723 }
6724
6725 if (err)
6726 l2cap_send_disconn_req(chan, ECONNRESET);
6727 } else {
6728 const u8 rx_func_to_event[4] = {
6729 L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ,
6730 L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ
6731 };
6732
6733 /* Only I-frames are expected in streaming mode */
6734 if (chan->mode == L2CAP_MODE_STREAMING)
6735 goto drop;
6736
6737 BT_DBG("sframe reqseq %d, final %d, poll %d, super %d",
6738 control->reqseq, control->final, control->poll,
6739 control->super);
6740
6741 if (len != 0) {
6742 BT_ERR("Trailing bytes: %d in sframe", len);
6743 l2cap_send_disconn_req(chan, ECONNRESET);
6744 goto drop;
6745 }
6746
6747 /* Validate F and P bits */
6748 if (control->final && (control->poll ||
6749 chan->tx_state != L2CAP_TX_STATE_WAIT_F))
6750 goto drop;
6751
6752 event = rx_func_to_event[control->super];
6753 if (l2cap_rx(chan, control, skb, event))
6754 l2cap_send_disconn_req(chan, ECONNRESET);
6755 }
6756
6757 return 0;
6758
6759drop:
6760 kfree_skb(skb);
6761 return 0;
6762}
6763
6764static void l2cap_chan_le_send_credits(struct l2cap_chan *chan)
6765{
6766 struct l2cap_conn *conn = chan->conn;
6767 struct l2cap_le_credits pkt;
6768 u16 return_credits;
6769
6770 return_credits = ((chan->imtu / chan->mps) + 1) - chan->rx_credits;
6771
6772 if (!return_credits)
6773 return;
6774
6775 BT_DBG("chan %p returning %u credits to sender", chan, return_credits);
6776
6777 chan->rx_credits += return_credits;
6778
6779 pkt.cid = cpu_to_le16(chan->scid);
6780 pkt.credits = cpu_to_le16(return_credits);
6781
6782 chan->ident = l2cap_get_ident(conn);
6783
6784 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt);
6785}
6786
6787static int l2cap_le_recv(struct l2cap_chan *chan, struct sk_buff *skb)
6788{
6789 int err;
6790
6791 BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len);
6792
6793 /* Wait recv to confirm reception before updating the credits */
6794 err = chan->ops->recv(chan, skb);
6795
6796 /* Update credits whenever an SDU is received */
6797 l2cap_chan_le_send_credits(chan);
6798
6799 return err;
6800}
6801
6802static int l2cap_le_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
6803{
6804 int err;
6805
6806 if (!chan->rx_credits) {
6807 BT_ERR("No credits to receive LE L2CAP data");
6808 l2cap_send_disconn_req(chan, ECONNRESET);
6809 return -ENOBUFS;
6810 }
6811
6812 if (chan->imtu < skb->len) {
6813 BT_ERR("Too big LE L2CAP PDU");
6814 return -ENOBUFS;
6815 }
6816
6817 chan->rx_credits--;
6818 BT_DBG("rx_credits %u -> %u", chan->rx_credits + 1, chan->rx_credits);
6819
6820 /* Update if remote had run out of credits, this should only happens
6821 * if the remote is not using the entire MPS.
6822 */
6823 if (!chan->rx_credits)
6824 l2cap_chan_le_send_credits(chan);
6825
6826 err = 0;
6827
6828 if (!chan->sdu) {
6829 u16 sdu_len;
6830
6831 sdu_len = get_unaligned_le16(skb->data);
6832 skb_pull(skb, L2CAP_SDULEN_SIZE);
6833
6834 BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u",
6835 sdu_len, skb->len, chan->imtu);
6836
6837 if (sdu_len > chan->imtu) {
6838 BT_ERR("Too big LE L2CAP SDU length received");
6839 err = -EMSGSIZE;
6840 goto failed;
6841 }
6842
6843 if (skb->len > sdu_len) {
6844 BT_ERR("Too much LE L2CAP data received");
6845 err = -EINVAL;
6846 goto failed;
6847 }
6848
6849 if (skb->len == sdu_len)
6850 return l2cap_le_recv(chan, skb);
6851
6852 chan->sdu = skb;
6853 chan->sdu_len = sdu_len;
6854 chan->sdu_last_frag = skb;
6855
6856 /* Detect if remote is not able to use the selected MPS */
6857 if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) {
6858 u16 mps_len = skb->len + L2CAP_SDULEN_SIZE;
6859
6860 /* Adjust the number of credits */
6861 BT_DBG("chan->mps %u -> %u", chan->mps, mps_len);
6862 chan->mps = mps_len;
6863 l2cap_chan_le_send_credits(chan);
6864 }
6865
6866 return 0;
6867 }
6868
6869 BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u",
6870 chan->sdu->len, skb->len, chan->sdu_len);
6871
6872 if (chan->sdu->len + skb->len > chan->sdu_len) {
6873 BT_ERR("Too much LE L2CAP data received");
6874 err = -EINVAL;
6875 goto failed;
6876 }
6877
6878 append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag);
6879 skb = NULL;
6880
6881 if (chan->sdu->len == chan->sdu_len) {
6882 err = l2cap_le_recv(chan, chan->sdu);
6883 if (!err) {
6884 chan->sdu = NULL;
6885 chan->sdu_last_frag = NULL;
6886 chan->sdu_len = 0;
6887 }
6888 }
6889
6890failed:
6891 if (err) {
6892 kfree_skb(skb);
6893 kfree_skb(chan->sdu);
6894 chan->sdu = NULL;
6895 chan->sdu_last_frag = NULL;
6896 chan->sdu_len = 0;
6897 }
6898
6899 /* We can't return an error here since we took care of the skb
6900 * freeing internally. An error return would cause the caller to
6901 * do a double-free of the skb.
6902 */
6903 return 0;
6904}
6905
6906static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,
6907 struct sk_buff *skb)
6908{
6909 struct l2cap_chan *chan;
6910
6911 chan = l2cap_get_chan_by_scid(conn, cid);
6912 if (!chan) {
6913 if (cid == L2CAP_CID_A2MP) {
6914 chan = a2mp_channel_create(conn, skb);
6915 if (!chan) {
6916 kfree_skb(skb);
6917 return;
6918 }
6919
6920 l2cap_chan_lock(chan);
6921 } else {
6922 BT_DBG("unknown cid 0x%4.4x", cid);
6923 /* Drop packet and return */
6924 kfree_skb(skb);
6925 return;
6926 }
6927 }
6928
6929 BT_DBG("chan %p, len %d", chan, skb->len);
6930
6931 /* If we receive data on a fixed channel before the info req/rsp
6932 * procdure is done simply assume that the channel is supported
6933 * and mark it as ready.
6934 */
6935 if (chan->chan_type == L2CAP_CHAN_FIXED)
6936 l2cap_chan_ready(chan);
6937
6938 if (chan->state != BT_CONNECTED)
6939 goto drop;
6940
6941 switch (chan->mode) {
6942 case L2CAP_MODE_LE_FLOWCTL:
6943 if (l2cap_le_data_rcv(chan, skb) < 0)
6944 goto drop;
6945
6946 goto done;
6947
6948 case L2CAP_MODE_BASIC:
6949 /* If socket recv buffers overflows we drop data here
6950 * which is *bad* because L2CAP has to be reliable.
6951 * But we don't have any other choice. L2CAP doesn't
6952 * provide flow control mechanism. */
6953
6954 if (chan->imtu < skb->len) {
6955 BT_ERR("Dropping L2CAP data: receive buffer overflow");
6956 goto drop;
6957 }
6958
6959 if (!chan->ops->recv(chan, skb))
6960 goto done;
6961 break;
6962
6963 case L2CAP_MODE_ERTM:
6964 case L2CAP_MODE_STREAMING:
6965 l2cap_data_rcv(chan, skb);
6966 goto done;
6967
6968 default:
6969 BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode);
6970 break;
6971 }
6972
6973drop:
6974 kfree_skb(skb);
6975
6976done:
6977 l2cap_chan_unlock(chan);
6978}
6979
6980static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm,
6981 struct sk_buff *skb)
6982{
6983 struct hci_conn *hcon = conn->hcon;
6984 struct l2cap_chan *chan;
6985
6986 if (hcon->type != ACL_LINK)
6987 goto free_skb;
6988
6989 chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst,
6990 ACL_LINK);
6991 if (!chan)
6992 goto free_skb;
6993
6994 BT_DBG("chan %p, len %d", chan, skb->len);
6995
6996 if (chan->state != BT_BOUND && chan->state != BT_CONNECTED)
6997 goto drop;
6998
6999 if (chan->imtu < skb->len)
7000 goto drop;
7001
7002 /* Store remote BD_ADDR and PSM for msg_name */
7003 bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst);
7004 bt_cb(skb)->l2cap.psm = psm;
7005
7006 if (!chan->ops->recv(chan, skb)) {
7007 l2cap_chan_put(chan);
7008 return;
7009 }
7010
7011drop:
7012 l2cap_chan_put(chan);
7013free_skb:
7014 kfree_skb(skb);
7015}
7016
7017static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
7018{
7019 struct l2cap_hdr *lh = (void *) skb->data;
7020 struct hci_conn *hcon = conn->hcon;
7021 u16 cid, len;
7022 __le16 psm;
7023
7024 if (hcon->state != BT_CONNECTED) {
7025 BT_DBG("queueing pending rx skb");
7026 skb_queue_tail(&conn->pending_rx, skb);
7027 return;
7028 }
7029
7030 skb_pull(skb, L2CAP_HDR_SIZE);
7031 cid = __le16_to_cpu(lh->cid);
7032 len = __le16_to_cpu(lh->len);
7033
7034 if (len != skb->len) {
7035 kfree_skb(skb);
7036 return;
7037 }
7038
7039 /* Since we can't actively block incoming LE connections we must
7040 * at least ensure that we ignore incoming data from them.
7041 */
7042 if (hcon->type == LE_LINK &&
7043 hci_bdaddr_list_lookup(&hcon->hdev->blacklist, &hcon->dst,
7044 bdaddr_dst_type(hcon))) {
7045 kfree_skb(skb);
7046 return;
7047 }
7048
7049 BT_DBG("len %d, cid 0x%4.4x", len, cid);
7050
7051 switch (cid) {
7052 case L2CAP_CID_SIGNALING:
7053 l2cap_sig_channel(conn, skb);
7054 break;
7055
7056 case L2CAP_CID_CONN_LESS:
7057 psm = get_unaligned((__le16 *) skb->data);
7058 skb_pull(skb, L2CAP_PSMLEN_SIZE);
7059 l2cap_conless_channel(conn, psm, skb);
7060 break;
7061
7062 case L2CAP_CID_LE_SIGNALING:
7063 l2cap_le_sig_channel(conn, skb);
7064 break;
7065
7066 default:
7067 l2cap_data_channel(conn, cid, skb);
7068 break;
7069 }
7070}
7071
7072static void process_pending_rx(struct work_struct *work)
7073{
7074 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
7075 pending_rx_work);
7076 struct sk_buff *skb;
7077
7078 BT_DBG("");
7079
7080 while ((skb = skb_dequeue(&conn->pending_rx)))
7081 l2cap_recv_frame(conn, skb);
7082}
7083
7084static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon)
7085{
7086 struct l2cap_conn *conn = hcon->l2cap_data;
7087 struct hci_chan *hchan;
7088
7089 if (conn)
7090 return conn;
7091
7092 hchan = hci_chan_create(hcon);
7093 if (!hchan)
7094 return NULL;
7095
7096 conn = kzalloc(sizeof(*conn), GFP_KERNEL);
7097 if (!conn) {
7098 hci_chan_del(hchan);
7099 return NULL;
7100 }
7101
7102 kref_init(&conn->ref);
7103 hcon->l2cap_data = conn;
7104 conn->hcon = hci_conn_get(hcon);
7105 conn->hchan = hchan;
7106
7107 BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan);
7108
7109 switch (hcon->type) {
7110 case LE_LINK:
7111 if (hcon->hdev->le_mtu) {
7112 conn->mtu = hcon->hdev->le_mtu;
7113 break;
7114 }
7115 /* fall through */
7116 default:
7117 conn->mtu = hcon->hdev->acl_mtu;
7118 break;
7119 }
7120
7121 conn->feat_mask = 0;
7122
7123 conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS;
7124
7125 if (hcon->type == ACL_LINK &&
7126 hci_dev_test_flag(hcon->hdev, HCI_HS_ENABLED))
7127 conn->local_fixed_chan |= L2CAP_FC_A2MP;
7128
7129 if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) &&
7130 (bredr_sc_enabled(hcon->hdev) ||
7131 hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP)))
7132 conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR;
7133
7134 mutex_init(&conn->ident_lock);
7135 mutex_init(&conn->chan_lock);
7136
7137 INIT_LIST_HEAD(&conn->chan_l);
7138 INIT_LIST_HEAD(&conn->users);
7139
7140 INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout);
7141
7142 skb_queue_head_init(&conn->pending_rx);
7143 INIT_WORK(&conn->pending_rx_work, process_pending_rx);
7144 INIT_WORK(&conn->id_addr_update_work, l2cap_conn_update_id_addr);
7145
7146 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
7147
7148 return conn;
7149}
7150
7151static bool is_valid_psm(u16 psm, u8 dst_type) {
7152 if (!psm)
7153 return false;
7154
7155 if (bdaddr_type_is_le(dst_type))
7156 return (psm <= 0x00ff);
7157
7158 /* PSM must be odd and lsb of upper byte must be 0 */
7159 return ((psm & 0x0101) == 0x0001);
7160}
7161
7162int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
7163 bdaddr_t *dst, u8 dst_type)
7164{
7165 struct l2cap_conn *conn;
7166 struct hci_conn *hcon;
7167 struct hci_dev *hdev;
7168 int err;
7169
7170 BT_DBG("%pMR -> %pMR (type %u) psm 0x%2.2x", &chan->src, dst,
7171 dst_type, __le16_to_cpu(psm));
7172
7173 hdev = hci_get_route(dst, &chan->src, chan->src_type);
7174 if (!hdev)
7175 return -EHOSTUNREACH;
7176
7177 hci_dev_lock(hdev);
7178
7179 if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid &&
7180 chan->chan_type != L2CAP_CHAN_RAW) {
7181 err = -EINVAL;
7182 goto done;
7183 }
7184
7185 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) {
7186 err = -EINVAL;
7187 goto done;
7188 }
7189
7190 if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) {
7191 err = -EINVAL;
7192 goto done;
7193 }
7194
7195 switch (chan->mode) {
7196 case L2CAP_MODE_BASIC:
7197 break;
7198 case L2CAP_MODE_LE_FLOWCTL:
7199 break;
7200 case L2CAP_MODE_ERTM:
7201 case L2CAP_MODE_STREAMING:
7202 if (!disable_ertm)
7203 break;
7204 /* fall through */
7205 default:
7206 err = -EOPNOTSUPP;
7207 goto done;
7208 }
7209
7210 switch (chan->state) {
7211 case BT_CONNECT:
7212 case BT_CONNECT2:
7213 case BT_CONFIG:
7214 /* Already connecting */
7215 err = 0;
7216 goto done;
7217
7218 case BT_CONNECTED:
7219 /* Already connected */
7220 err = -EISCONN;
7221 goto done;
7222
7223 case BT_OPEN:
7224 case BT_BOUND:
7225 /* Can connect */
7226 break;
7227
7228 default:
7229 err = -EBADFD;
7230 goto done;
7231 }
7232
7233 /* Set destination address and psm */
7234 bacpy(&chan->dst, dst);
7235 chan->dst_type = dst_type;
7236
7237 chan->psm = psm;
7238 chan->dcid = cid;
7239
7240 if (bdaddr_type_is_le(dst_type)) {
7241 /* Convert from L2CAP channel address type to HCI address type
7242 */
7243 if (dst_type == BDADDR_LE_PUBLIC)
7244 dst_type = ADDR_LE_DEV_PUBLIC;
7245 else
7246 dst_type = ADDR_LE_DEV_RANDOM;
7247
7248 if (hci_dev_test_flag(hdev, HCI_ADVERTISING))
7249 hcon = hci_connect_le(hdev, dst, dst_type,
7250 chan->sec_level,
7251 HCI_LE_CONN_TIMEOUT,
7252 HCI_ROLE_SLAVE, NULL);
7253 else
7254 hcon = hci_connect_le_scan(hdev, dst, dst_type,
7255 chan->sec_level,
7256 HCI_LE_CONN_TIMEOUT);
7257
7258 } else {
7259 u8 auth_type = l2cap_get_auth_type(chan);
7260 hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type);
7261 }
7262
7263 if (IS_ERR(hcon)) {
7264 err = PTR_ERR(hcon);
7265 goto done;
7266 }
7267
7268 conn = l2cap_conn_add(hcon);
7269 if (!conn) {
7270 hci_conn_drop(hcon);
7271 err = -ENOMEM;
7272 goto done;
7273 }
7274
7275 mutex_lock(&conn->chan_lock);
7276 l2cap_chan_lock(chan);
7277
7278 if (cid && __l2cap_get_chan_by_dcid(conn, cid)) {
7279 hci_conn_drop(hcon);
7280 err = -EBUSY;
7281 goto chan_unlock;
7282 }
7283
7284 /* Update source addr of the socket */
7285 bacpy(&chan->src, &hcon->src);
7286 chan->src_type = bdaddr_src_type(hcon);
7287
7288 __l2cap_chan_add(conn, chan);
7289
7290 /* l2cap_chan_add takes its own ref so we can drop this one */
7291 hci_conn_drop(hcon);
7292
7293 l2cap_state_change(chan, BT_CONNECT);
7294 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
7295
7296 /* Release chan->sport so that it can be reused by other
7297 * sockets (as it's only used for listening sockets).
7298 */
7299 write_lock(&chan_list_lock);
7300 chan->sport = 0;
7301 write_unlock(&chan_list_lock);
7302
7303 if (hcon->state == BT_CONNECTED) {
7304 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
7305 __clear_chan_timer(chan);
7306 if (l2cap_chan_check_security(chan, true))
7307 l2cap_state_change(chan, BT_CONNECTED);
7308 } else
7309 l2cap_do_start(chan);
7310 }
7311
7312 err = 0;
7313
7314chan_unlock:
7315 l2cap_chan_unlock(chan);
7316 mutex_unlock(&conn->chan_lock);
7317done:
7318 hci_dev_unlock(hdev);
7319 hci_dev_put(hdev);
7320 return err;
7321}
7322EXPORT_SYMBOL_GPL(l2cap_chan_connect);
7323
7324/* ---- L2CAP interface with lower layer (HCI) ---- */
7325
7326int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr)
7327{
7328 int exact = 0, lm1 = 0, lm2 = 0;
7329 struct l2cap_chan *c;
7330
7331 BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr);
7332
7333 /* Find listening sockets and check their link_mode */
7334 read_lock(&chan_list_lock);
7335 list_for_each_entry(c, &chan_list, global_l) {
7336 if (c->state != BT_LISTEN)
7337 continue;
7338
7339 if (!bacmp(&c->src, &hdev->bdaddr)) {
7340 lm1 |= HCI_LM_ACCEPT;
7341 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
7342 lm1 |= HCI_LM_MASTER;
7343 exact++;
7344 } else if (!bacmp(&c->src, BDADDR_ANY)) {
7345 lm2 |= HCI_LM_ACCEPT;
7346 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
7347 lm2 |= HCI_LM_MASTER;
7348 }
7349 }
7350 read_unlock(&chan_list_lock);
7351
7352 return exact ? lm1 : lm2;
7353}
7354
7355/* Find the next fixed channel in BT_LISTEN state, continue iteration
7356 * from an existing channel in the list or from the beginning of the
7357 * global list (by passing NULL as first parameter).
7358 */
7359static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c,
7360 struct hci_conn *hcon)
7361{
7362 u8 src_type = bdaddr_src_type(hcon);
7363
7364 read_lock(&chan_list_lock);
7365
7366 if (c)
7367 c = list_next_entry(c, global_l);
7368 else
7369 c = list_entry(chan_list.next, typeof(*c), global_l);
7370
7371 list_for_each_entry_from(c, &chan_list, global_l) {
7372 if (c->chan_type != L2CAP_CHAN_FIXED)
7373 continue;
7374 if (c->state != BT_LISTEN)
7375 continue;
7376 if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY))
7377 continue;
7378 if (src_type != c->src_type)
7379 continue;
7380
7381 l2cap_chan_hold(c);
7382 read_unlock(&chan_list_lock);
7383 return c;
7384 }
7385
7386 read_unlock(&chan_list_lock);
7387
7388 return NULL;
7389}
7390
7391static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status)
7392{
7393 struct hci_dev *hdev = hcon->hdev;
7394 struct l2cap_conn *conn;
7395 struct l2cap_chan *pchan;
7396 u8 dst_type;
7397
7398 if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
7399 return;
7400
7401 BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status);
7402
7403 if (status) {
7404 l2cap_conn_del(hcon, bt_to_errno(status));
7405 return;
7406 }
7407
7408 conn = l2cap_conn_add(hcon);
7409 if (!conn)
7410 return;
7411
7412 dst_type = bdaddr_dst_type(hcon);
7413
7414 /* If device is blocked, do not create channels for it */
7415 if (hci_bdaddr_list_lookup(&hdev->blacklist, &hcon->dst, dst_type))
7416 return;
7417
7418 /* Find fixed channels and notify them of the new connection. We
7419 * use multiple individual lookups, continuing each time where
7420 * we left off, because the list lock would prevent calling the
7421 * potentially sleeping l2cap_chan_lock() function.
7422 */
7423 pchan = l2cap_global_fixed_chan(NULL, hcon);
7424 while (pchan) {
7425 struct l2cap_chan *chan, *next;
7426
7427 /* Client fixed channels should override server ones */
7428 if (__l2cap_get_chan_by_dcid(conn, pchan->scid))
7429 goto next;
7430
7431 l2cap_chan_lock(pchan);
7432 chan = pchan->ops->new_connection(pchan);
7433 if (chan) {
7434 bacpy(&chan->src, &hcon->src);
7435 bacpy(&chan->dst, &hcon->dst);
7436 chan->src_type = bdaddr_src_type(hcon);
7437 chan->dst_type = dst_type;
7438
7439 __l2cap_chan_add(conn, chan);
7440 }
7441
7442 l2cap_chan_unlock(pchan);
7443next:
7444 next = l2cap_global_fixed_chan(pchan, hcon);
7445 l2cap_chan_put(pchan);
7446 pchan = next;
7447 }
7448
7449 l2cap_conn_ready(conn);
7450}
7451
7452int l2cap_disconn_ind(struct hci_conn *hcon)
7453{
7454 struct l2cap_conn *conn = hcon->l2cap_data;
7455
7456 BT_DBG("hcon %p", hcon);
7457
7458 if (!conn)
7459 return HCI_ERROR_REMOTE_USER_TERM;
7460 return conn->disc_reason;
7461}
7462
7463static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)
7464{
7465 if (hcon->type != ACL_LINK && hcon->type != LE_LINK)
7466 return;
7467
7468 BT_DBG("hcon %p reason %d", hcon, reason);
7469
7470 l2cap_conn_del(hcon, bt_to_errno(reason));
7471}
7472
7473static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt)
7474{
7475 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
7476 return;
7477
7478 if (encrypt == 0x00) {
7479 if (chan->sec_level == BT_SECURITY_MEDIUM) {
7480 __set_chan_timer(chan, L2CAP_ENC_TIMEOUT);
7481 } else if (chan->sec_level == BT_SECURITY_HIGH ||
7482 chan->sec_level == BT_SECURITY_FIPS)
7483 l2cap_chan_close(chan, ECONNREFUSED);
7484 } else {
7485 if (chan->sec_level == BT_SECURITY_MEDIUM)
7486 __clear_chan_timer(chan);
7487 }
7488}
7489
7490static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
7491{
7492 struct l2cap_conn *conn = hcon->l2cap_data;
7493 struct l2cap_chan *chan;
7494
7495 if (!conn)
7496 return;
7497
7498 BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt);
7499
7500 mutex_lock(&conn->chan_lock);
7501
7502 list_for_each_entry(chan, &conn->chan_l, list) {
7503 l2cap_chan_lock(chan);
7504
7505 BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid,
7506 state_to_string(chan->state));
7507
7508 if (chan->scid == L2CAP_CID_A2MP) {
7509 l2cap_chan_unlock(chan);
7510 continue;
7511 }
7512
7513 if (!status && encrypt)
7514 chan->sec_level = hcon->sec_level;
7515
7516 if (!__l2cap_no_conn_pending(chan)) {
7517 l2cap_chan_unlock(chan);
7518 continue;
7519 }
7520
7521 if (!status && (chan->state == BT_CONNECTED ||
7522 chan->state == BT_CONFIG)) {
7523 chan->ops->resume(chan);
7524 l2cap_check_encryption(chan, encrypt);
7525 l2cap_chan_unlock(chan);
7526 continue;
7527 }
7528
7529 if (chan->state == BT_CONNECT) {
7530 if (!status && l2cap_check_enc_key_size(hcon))
7531 l2cap_start_connection(chan);
7532 else
7533 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
7534 } else if (chan->state == BT_CONNECT2 &&
7535 chan->mode != L2CAP_MODE_LE_FLOWCTL) {
7536 struct l2cap_conn_rsp rsp;
7537 __u16 res, stat;
7538
7539 if (!status && l2cap_check_enc_key_size(hcon)) {
7540 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
7541 res = L2CAP_CR_PEND;
7542 stat = L2CAP_CS_AUTHOR_PEND;
7543 chan->ops->defer(chan);
7544 } else {
7545 l2cap_state_change(chan, BT_CONFIG);
7546 res = L2CAP_CR_SUCCESS;
7547 stat = L2CAP_CS_NO_INFO;
7548 }
7549 } else {
7550 l2cap_state_change(chan, BT_DISCONN);
7551 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
7552 res = L2CAP_CR_SEC_BLOCK;
7553 stat = L2CAP_CS_NO_INFO;
7554 }
7555
7556 rsp.scid = cpu_to_le16(chan->dcid);
7557 rsp.dcid = cpu_to_le16(chan->scid);
7558 rsp.result = cpu_to_le16(res);
7559 rsp.status = cpu_to_le16(stat);
7560 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
7561 sizeof(rsp), &rsp);
7562
7563 if (!test_bit(CONF_REQ_SENT, &chan->conf_state) &&
7564 res == L2CAP_CR_SUCCESS) {
7565 char buf[128];
7566 set_bit(CONF_REQ_SENT, &chan->conf_state);
7567 l2cap_send_cmd(conn, l2cap_get_ident(conn),
7568 L2CAP_CONF_REQ,
7569 l2cap_build_conf_req(chan, buf, sizeof(buf)),
7570 buf);
7571 chan->num_conf_req++;
7572 }
7573 }
7574
7575 l2cap_chan_unlock(chan);
7576 }
7577
7578 mutex_unlock(&conn->chan_lock);
7579}
7580
7581void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
7582{
7583 struct l2cap_conn *conn = hcon->l2cap_data;
7584 struct l2cap_hdr *hdr;
7585 int len;
7586
7587 /* For AMP controller do not create l2cap conn */
7588 if (!conn && hcon->hdev->dev_type != HCI_PRIMARY)
7589 goto drop;
7590
7591 if (!conn)
7592 conn = l2cap_conn_add(hcon);
7593
7594 if (!conn)
7595 goto drop;
7596
7597 BT_DBG("conn %p len %d flags 0x%x", conn, skb->len, flags);
7598
7599 switch (flags) {
7600 case ACL_START:
7601 case ACL_START_NO_FLUSH:
7602 case ACL_COMPLETE:
7603 if (conn->rx_len) {
7604 BT_ERR("Unexpected start frame (len %d)", skb->len);
7605 kfree_skb(conn->rx_skb);
7606 conn->rx_skb = NULL;
7607 conn->rx_len = 0;
7608 l2cap_conn_unreliable(conn, ECOMM);
7609 }
7610
7611 /* Start fragment always begin with Basic L2CAP header */
7612 if (skb->len < L2CAP_HDR_SIZE) {
7613 BT_ERR("Frame is too short (len %d)", skb->len);
7614 l2cap_conn_unreliable(conn, ECOMM);
7615 goto drop;
7616 }
7617
7618 hdr = (struct l2cap_hdr *) skb->data;
7619 len = __le16_to_cpu(hdr->len) + L2CAP_HDR_SIZE;
7620
7621 if (len == skb->len) {
7622 /* Complete frame received */
7623 l2cap_recv_frame(conn, skb);
7624 return;
7625 }
7626
7627 BT_DBG("Start: total len %d, frag len %d", len, skb->len);
7628
7629 if (skb->len > len) {
7630 BT_ERR("Frame is too long (len %d, expected len %d)",
7631 skb->len, len);
7632 l2cap_conn_unreliable(conn, ECOMM);
7633 goto drop;
7634 }
7635
7636 /* Allocate skb for the complete frame (with header) */
7637 conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL);
7638 if (!conn->rx_skb)
7639 goto drop;
7640
7641 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len),
7642 skb->len);
7643 conn->rx_len = len - skb->len;
7644 break;
7645
7646 case ACL_CONT:
7647 BT_DBG("Cont: frag len %d (expecting %d)", skb->len, conn->rx_len);
7648
7649 if (!conn->rx_len) {
7650 BT_ERR("Unexpected continuation frame (len %d)", skb->len);
7651 l2cap_conn_unreliable(conn, ECOMM);
7652 goto drop;
7653 }
7654
7655 if (skb->len > conn->rx_len) {
7656 BT_ERR("Fragment is too long (len %d, expected %d)",
7657 skb->len, conn->rx_len);
7658 kfree_skb(conn->rx_skb);
7659 conn->rx_skb = NULL;
7660 conn->rx_len = 0;
7661 l2cap_conn_unreliable(conn, ECOMM);
7662 goto drop;
7663 }
7664
7665 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len),
7666 skb->len);
7667 conn->rx_len -= skb->len;
7668
7669 if (!conn->rx_len) {
7670 /* Complete frame received. l2cap_recv_frame
7671 * takes ownership of the skb so set the global
7672 * rx_skb pointer to NULL first.
7673 */
7674 struct sk_buff *rx_skb = conn->rx_skb;
7675 conn->rx_skb = NULL;
7676 l2cap_recv_frame(conn, rx_skb);
7677 }
7678 break;
7679 }
7680
7681drop:
7682 kfree_skb(skb);
7683}
7684
7685static struct hci_cb l2cap_cb = {
7686 .name = "L2CAP",
7687 .connect_cfm = l2cap_connect_cfm,
7688 .disconn_cfm = l2cap_disconn_cfm,
7689 .security_cfm = l2cap_security_cfm,
7690};
7691
7692static int l2cap_debugfs_show(struct seq_file *f, void *p)
7693{
7694 struct l2cap_chan *c;
7695
7696 read_lock(&chan_list_lock);
7697
7698 list_for_each_entry(c, &chan_list, global_l) {
7699 seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n",
7700 &c->src, c->src_type, &c->dst, c->dst_type,
7701 c->state, __le16_to_cpu(c->psm),
7702 c->scid, c->dcid, c->imtu, c->omtu,
7703 c->sec_level, c->mode);
7704 }
7705
7706 read_unlock(&chan_list_lock);
7707
7708 return 0;
7709}
7710
7711DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs);
7712
7713static struct dentry *l2cap_debugfs;
7714
7715int __init l2cap_init(void)
7716{
7717 int err;
7718
7719 err = l2cap_init_sockets();
7720 if (err < 0)
7721 return err;
7722
7723 hci_register_cb(&l2cap_cb);
7724
7725 if (IS_ERR_OR_NULL(bt_debugfs))
7726 return 0;
7727
7728 l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs,
7729 NULL, &l2cap_debugfs_fops);
7730
7731 return 0;
7732}
7733
7734void l2cap_exit(void)
7735{
7736 debugfs_remove(l2cap_debugfs);
7737 hci_unregister_cb(&l2cap_cb);
7738 l2cap_cleanup_sockets();
7739}
7740
7741module_param(disable_ertm, bool, 0644);
7742MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode");
1/*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2000-2001 Qualcomm Incorporated
4 Copyright (C) 2009-2010 Gustavo F. Padovan <gustavo@padovan.org>
5 Copyright (C) 2010 Google Inc.
6 Copyright (C) 2011 ProFUSION Embedded Systems
7 Copyright (c) 2012 Code Aurora Forum. All rights reserved.
8
9 Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
10
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License version 2 as
13 published by the Free Software Foundation;
14
15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
16 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
18 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
19 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
20 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
21 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
22 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23
24 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
25 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
26 SOFTWARE IS DISCLAIMED.
27*/
28
29/* Bluetooth L2CAP core. */
30
31#include <linux/module.h>
32
33#include <linux/debugfs.h>
34#include <linux/crc16.h>
35#include <linux/filter.h>
36
37#include <net/bluetooth/bluetooth.h>
38#include <net/bluetooth/hci_core.h>
39#include <net/bluetooth/l2cap.h>
40
41#include "smp.h"
42
43#define LE_FLOWCTL_MAX_CREDITS 65535
44
45bool disable_ertm;
46bool enable_ecred = IS_ENABLED(CONFIG_BT_LE_L2CAP_ECRED);
47
48static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN | L2CAP_FEAT_UCD;
49
50static LIST_HEAD(chan_list);
51static DEFINE_RWLOCK(chan_list_lock);
52
53static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
54 u8 code, u8 ident, u16 dlen, void *data);
55static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
56 void *data);
57static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size);
58static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err);
59
60static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
61 struct sk_buff_head *skbs, u8 event);
62static void l2cap_retrans_timeout(struct work_struct *work);
63static void l2cap_monitor_timeout(struct work_struct *work);
64static void l2cap_ack_timeout(struct work_struct *work);
65
66static inline u8 bdaddr_type(u8 link_type, u8 bdaddr_type)
67{
68 if (link_type == LE_LINK) {
69 if (bdaddr_type == ADDR_LE_DEV_PUBLIC)
70 return BDADDR_LE_PUBLIC;
71 else
72 return BDADDR_LE_RANDOM;
73 }
74
75 return BDADDR_BREDR;
76}
77
78static inline u8 bdaddr_src_type(struct hci_conn *hcon)
79{
80 return bdaddr_type(hcon->type, hcon->src_type);
81}
82
83static inline u8 bdaddr_dst_type(struct hci_conn *hcon)
84{
85 return bdaddr_type(hcon->type, hcon->dst_type);
86}
87
88/* ---- L2CAP channels ---- */
89
90static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
91 u16 cid)
92{
93 struct l2cap_chan *c;
94
95 list_for_each_entry(c, &conn->chan_l, list) {
96 if (c->dcid == cid)
97 return c;
98 }
99 return NULL;
100}
101
102static struct l2cap_chan *__l2cap_get_chan_by_scid(struct l2cap_conn *conn,
103 u16 cid)
104{
105 struct l2cap_chan *c;
106
107 list_for_each_entry(c, &conn->chan_l, list) {
108 if (c->scid == cid)
109 return c;
110 }
111 return NULL;
112}
113
114/* Find channel with given SCID.
115 * Returns a reference locked channel.
116 */
117static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn,
118 u16 cid)
119{
120 struct l2cap_chan *c;
121
122 mutex_lock(&conn->chan_lock);
123 c = __l2cap_get_chan_by_scid(conn, cid);
124 if (c) {
125 /* Only lock if chan reference is not 0 */
126 c = l2cap_chan_hold_unless_zero(c);
127 if (c)
128 l2cap_chan_lock(c);
129 }
130 mutex_unlock(&conn->chan_lock);
131
132 return c;
133}
134
135/* Find channel with given DCID.
136 * Returns a reference locked channel.
137 */
138static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
139 u16 cid)
140{
141 struct l2cap_chan *c;
142
143 mutex_lock(&conn->chan_lock);
144 c = __l2cap_get_chan_by_dcid(conn, cid);
145 if (c) {
146 /* Only lock if chan reference is not 0 */
147 c = l2cap_chan_hold_unless_zero(c);
148 if (c)
149 l2cap_chan_lock(c);
150 }
151 mutex_unlock(&conn->chan_lock);
152
153 return c;
154}
155
156static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn,
157 u8 ident)
158{
159 struct l2cap_chan *c;
160
161 list_for_each_entry(c, &conn->chan_l, list) {
162 if (c->ident == ident)
163 return c;
164 }
165 return NULL;
166}
167
168static struct l2cap_chan *__l2cap_global_chan_by_addr(__le16 psm, bdaddr_t *src,
169 u8 src_type)
170{
171 struct l2cap_chan *c;
172
173 list_for_each_entry(c, &chan_list, global_l) {
174 if (src_type == BDADDR_BREDR && c->src_type != BDADDR_BREDR)
175 continue;
176
177 if (src_type != BDADDR_BREDR && c->src_type == BDADDR_BREDR)
178 continue;
179
180 if (c->sport == psm && !bacmp(&c->src, src))
181 return c;
182 }
183 return NULL;
184}
185
186int l2cap_add_psm(struct l2cap_chan *chan, bdaddr_t *src, __le16 psm)
187{
188 int err;
189
190 write_lock(&chan_list_lock);
191
192 if (psm && __l2cap_global_chan_by_addr(psm, src, chan->src_type)) {
193 err = -EADDRINUSE;
194 goto done;
195 }
196
197 if (psm) {
198 chan->psm = psm;
199 chan->sport = psm;
200 err = 0;
201 } else {
202 u16 p, start, end, incr;
203
204 if (chan->src_type == BDADDR_BREDR) {
205 start = L2CAP_PSM_DYN_START;
206 end = L2CAP_PSM_AUTO_END;
207 incr = 2;
208 } else {
209 start = L2CAP_PSM_LE_DYN_START;
210 end = L2CAP_PSM_LE_DYN_END;
211 incr = 1;
212 }
213
214 err = -EINVAL;
215 for (p = start; p <= end; p += incr)
216 if (!__l2cap_global_chan_by_addr(cpu_to_le16(p), src,
217 chan->src_type)) {
218 chan->psm = cpu_to_le16(p);
219 chan->sport = cpu_to_le16(p);
220 err = 0;
221 break;
222 }
223 }
224
225done:
226 write_unlock(&chan_list_lock);
227 return err;
228}
229EXPORT_SYMBOL_GPL(l2cap_add_psm);
230
231int l2cap_add_scid(struct l2cap_chan *chan, __u16 scid)
232{
233 write_lock(&chan_list_lock);
234
235 /* Override the defaults (which are for conn-oriented) */
236 chan->omtu = L2CAP_DEFAULT_MTU;
237 chan->chan_type = L2CAP_CHAN_FIXED;
238
239 chan->scid = scid;
240
241 write_unlock(&chan_list_lock);
242
243 return 0;
244}
245
246static u16 l2cap_alloc_cid(struct l2cap_conn *conn)
247{
248 u16 cid, dyn_end;
249
250 if (conn->hcon->type == LE_LINK)
251 dyn_end = L2CAP_CID_LE_DYN_END;
252 else
253 dyn_end = L2CAP_CID_DYN_END;
254
255 for (cid = L2CAP_CID_DYN_START; cid <= dyn_end; cid++) {
256 if (!__l2cap_get_chan_by_scid(conn, cid))
257 return cid;
258 }
259
260 return 0;
261}
262
263static void l2cap_state_change(struct l2cap_chan *chan, int state)
264{
265 BT_DBG("chan %p %s -> %s", chan, state_to_string(chan->state),
266 state_to_string(state));
267
268 chan->state = state;
269 chan->ops->state_change(chan, state, 0);
270}
271
272static inline void l2cap_state_change_and_error(struct l2cap_chan *chan,
273 int state, int err)
274{
275 chan->state = state;
276 chan->ops->state_change(chan, chan->state, err);
277}
278
279static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
280{
281 chan->ops->state_change(chan, chan->state, err);
282}
283
284static void __set_retrans_timer(struct l2cap_chan *chan)
285{
286 if (!delayed_work_pending(&chan->monitor_timer) &&
287 chan->retrans_timeout) {
288 l2cap_set_timer(chan, &chan->retrans_timer,
289 msecs_to_jiffies(chan->retrans_timeout));
290 }
291}
292
293static void __set_monitor_timer(struct l2cap_chan *chan)
294{
295 __clear_retrans_timer(chan);
296 if (chan->monitor_timeout) {
297 l2cap_set_timer(chan, &chan->monitor_timer,
298 msecs_to_jiffies(chan->monitor_timeout));
299 }
300}
301
302static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head,
303 u16 seq)
304{
305 struct sk_buff *skb;
306
307 skb_queue_walk(head, skb) {
308 if (bt_cb(skb)->l2cap.txseq == seq)
309 return skb;
310 }
311
312 return NULL;
313}
314
315/* ---- L2CAP sequence number lists ---- */
316
317/* For ERTM, ordered lists of sequence numbers must be tracked for
318 * SREJ requests that are received and for frames that are to be
319 * retransmitted. These seq_list functions implement a singly-linked
320 * list in an array, where membership in the list can also be checked
321 * in constant time. Items can also be added to the tail of the list
322 * and removed from the head in constant time, without further memory
323 * allocs or frees.
324 */
325
326static int l2cap_seq_list_init(struct l2cap_seq_list *seq_list, u16 size)
327{
328 size_t alloc_size, i;
329
330 /* Allocated size is a power of 2 to map sequence numbers
331 * (which may be up to 14 bits) in to a smaller array that is
332 * sized for the negotiated ERTM transmit windows.
333 */
334 alloc_size = roundup_pow_of_two(size);
335
336 seq_list->list = kmalloc_array(alloc_size, sizeof(u16), GFP_KERNEL);
337 if (!seq_list->list)
338 return -ENOMEM;
339
340 seq_list->mask = alloc_size - 1;
341 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
342 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
343 for (i = 0; i < alloc_size; i++)
344 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
345
346 return 0;
347}
348
349static inline void l2cap_seq_list_free(struct l2cap_seq_list *seq_list)
350{
351 kfree(seq_list->list);
352}
353
354static inline bool l2cap_seq_list_contains(struct l2cap_seq_list *seq_list,
355 u16 seq)
356{
357 /* Constant-time check for list membership */
358 return seq_list->list[seq & seq_list->mask] != L2CAP_SEQ_LIST_CLEAR;
359}
360
361static inline u16 l2cap_seq_list_pop(struct l2cap_seq_list *seq_list)
362{
363 u16 seq = seq_list->head;
364 u16 mask = seq_list->mask;
365
366 seq_list->head = seq_list->list[seq & mask];
367 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_CLEAR;
368
369 if (seq_list->head == L2CAP_SEQ_LIST_TAIL) {
370 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
371 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
372 }
373
374 return seq;
375}
376
377static void l2cap_seq_list_clear(struct l2cap_seq_list *seq_list)
378{
379 u16 i;
380
381 if (seq_list->head == L2CAP_SEQ_LIST_CLEAR)
382 return;
383
384 for (i = 0; i <= seq_list->mask; i++)
385 seq_list->list[i] = L2CAP_SEQ_LIST_CLEAR;
386
387 seq_list->head = L2CAP_SEQ_LIST_CLEAR;
388 seq_list->tail = L2CAP_SEQ_LIST_CLEAR;
389}
390
391static void l2cap_seq_list_append(struct l2cap_seq_list *seq_list, u16 seq)
392{
393 u16 mask = seq_list->mask;
394
395 /* All appends happen in constant time */
396
397 if (seq_list->list[seq & mask] != L2CAP_SEQ_LIST_CLEAR)
398 return;
399
400 if (seq_list->tail == L2CAP_SEQ_LIST_CLEAR)
401 seq_list->head = seq;
402 else
403 seq_list->list[seq_list->tail & mask] = seq;
404
405 seq_list->tail = seq;
406 seq_list->list[seq & mask] = L2CAP_SEQ_LIST_TAIL;
407}
408
409static void l2cap_chan_timeout(struct work_struct *work)
410{
411 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
412 chan_timer.work);
413 struct l2cap_conn *conn = chan->conn;
414 int reason;
415
416 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
417
418 if (!conn)
419 return;
420
421 mutex_lock(&conn->chan_lock);
422 /* __set_chan_timer() calls l2cap_chan_hold(chan) while scheduling
423 * this work. No need to call l2cap_chan_hold(chan) here again.
424 */
425 l2cap_chan_lock(chan);
426
427 if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
428 reason = ECONNREFUSED;
429 else if (chan->state == BT_CONNECT &&
430 chan->sec_level != BT_SECURITY_SDP)
431 reason = ECONNREFUSED;
432 else
433 reason = ETIMEDOUT;
434
435 l2cap_chan_close(chan, reason);
436
437 chan->ops->close(chan);
438
439 l2cap_chan_unlock(chan);
440 l2cap_chan_put(chan);
441
442 mutex_unlock(&conn->chan_lock);
443}
444
445struct l2cap_chan *l2cap_chan_create(void)
446{
447 struct l2cap_chan *chan;
448
449 chan = kzalloc(sizeof(*chan), GFP_ATOMIC);
450 if (!chan)
451 return NULL;
452
453 skb_queue_head_init(&chan->tx_q);
454 skb_queue_head_init(&chan->srej_q);
455 mutex_init(&chan->lock);
456
457 /* Set default lock nesting level */
458 atomic_set(&chan->nesting, L2CAP_NESTING_NORMAL);
459
460 /* Available receive buffer space is initially unknown */
461 chan->rx_avail = -1;
462
463 write_lock(&chan_list_lock);
464 list_add(&chan->global_l, &chan_list);
465 write_unlock(&chan_list_lock);
466
467 INIT_DELAYED_WORK(&chan->chan_timer, l2cap_chan_timeout);
468 INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout);
469 INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout);
470 INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout);
471
472 chan->state = BT_OPEN;
473
474 kref_init(&chan->kref);
475
476 /* This flag is cleared in l2cap_chan_ready() */
477 set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
478
479 BT_DBG("chan %p", chan);
480
481 return chan;
482}
483EXPORT_SYMBOL_GPL(l2cap_chan_create);
484
485static void l2cap_chan_destroy(struct kref *kref)
486{
487 struct l2cap_chan *chan = container_of(kref, struct l2cap_chan, kref);
488
489 BT_DBG("chan %p", chan);
490
491 write_lock(&chan_list_lock);
492 list_del(&chan->global_l);
493 write_unlock(&chan_list_lock);
494
495 kfree(chan);
496}
497
498void l2cap_chan_hold(struct l2cap_chan *c)
499{
500 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
501
502 kref_get(&c->kref);
503}
504
505struct l2cap_chan *l2cap_chan_hold_unless_zero(struct l2cap_chan *c)
506{
507 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
508
509 if (!kref_get_unless_zero(&c->kref))
510 return NULL;
511
512 return c;
513}
514
515void l2cap_chan_put(struct l2cap_chan *c)
516{
517 BT_DBG("chan %p orig refcnt %u", c, kref_read(&c->kref));
518
519 kref_put(&c->kref, l2cap_chan_destroy);
520}
521EXPORT_SYMBOL_GPL(l2cap_chan_put);
522
523void l2cap_chan_set_defaults(struct l2cap_chan *chan)
524{
525 chan->fcs = L2CAP_FCS_CRC16;
526 chan->max_tx = L2CAP_DEFAULT_MAX_TX;
527 chan->tx_win = L2CAP_DEFAULT_TX_WINDOW;
528 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
529 chan->remote_max_tx = chan->max_tx;
530 chan->remote_tx_win = chan->tx_win;
531 chan->ack_win = L2CAP_DEFAULT_TX_WINDOW;
532 chan->sec_level = BT_SECURITY_LOW;
533 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
534 chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO;
535 chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO;
536
537 chan->conf_state = 0;
538 set_bit(CONF_NOT_COMPLETE, &chan->conf_state);
539
540 set_bit(FLAG_FORCE_ACTIVE, &chan->flags);
541}
542EXPORT_SYMBOL_GPL(l2cap_chan_set_defaults);
543
544static __u16 l2cap_le_rx_credits(struct l2cap_chan *chan)
545{
546 size_t sdu_len = chan->sdu ? chan->sdu->len : 0;
547
548 if (chan->mps == 0)
549 return 0;
550
551 /* If we don't know the available space in the receiver buffer, give
552 * enough credits for a full packet.
553 */
554 if (chan->rx_avail == -1)
555 return (chan->imtu / chan->mps) + 1;
556
557 /* If we know how much space is available in the receive buffer, give
558 * out as many credits as would fill the buffer.
559 */
560 if (chan->rx_avail <= sdu_len)
561 return 0;
562
563 return DIV_ROUND_UP(chan->rx_avail - sdu_len, chan->mps);
564}
565
566static void l2cap_le_flowctl_init(struct l2cap_chan *chan, u16 tx_credits)
567{
568 chan->sdu = NULL;
569 chan->sdu_last_frag = NULL;
570 chan->sdu_len = 0;
571 chan->tx_credits = tx_credits;
572 /* Derive MPS from connection MTU to stop HCI fragmentation */
573 chan->mps = min_t(u16, chan->imtu, chan->conn->mtu - L2CAP_HDR_SIZE);
574 chan->rx_credits = l2cap_le_rx_credits(chan);
575
576 skb_queue_head_init(&chan->tx_q);
577}
578
579static void l2cap_ecred_init(struct l2cap_chan *chan, u16 tx_credits)
580{
581 l2cap_le_flowctl_init(chan, tx_credits);
582
583 /* L2CAP implementations shall support a minimum MPS of 64 octets */
584 if (chan->mps < L2CAP_ECRED_MIN_MPS) {
585 chan->mps = L2CAP_ECRED_MIN_MPS;
586 chan->rx_credits = l2cap_le_rx_credits(chan);
587 }
588}
589
590void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
591{
592 BT_DBG("conn %p, psm 0x%2.2x, dcid 0x%4.4x", conn,
593 __le16_to_cpu(chan->psm), chan->dcid);
594
595 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
596
597 chan->conn = conn;
598
599 switch (chan->chan_type) {
600 case L2CAP_CHAN_CONN_ORIENTED:
601 /* Alloc CID for connection-oriented socket */
602 chan->scid = l2cap_alloc_cid(conn);
603 if (conn->hcon->type == ACL_LINK)
604 chan->omtu = L2CAP_DEFAULT_MTU;
605 break;
606
607 case L2CAP_CHAN_CONN_LESS:
608 /* Connectionless socket */
609 chan->scid = L2CAP_CID_CONN_LESS;
610 chan->dcid = L2CAP_CID_CONN_LESS;
611 chan->omtu = L2CAP_DEFAULT_MTU;
612 break;
613
614 case L2CAP_CHAN_FIXED:
615 /* Caller will set CID and CID specific MTU values */
616 break;
617
618 default:
619 /* Raw socket can send/recv signalling messages only */
620 chan->scid = L2CAP_CID_SIGNALING;
621 chan->dcid = L2CAP_CID_SIGNALING;
622 chan->omtu = L2CAP_DEFAULT_MTU;
623 }
624
625 chan->local_id = L2CAP_BESTEFFORT_ID;
626 chan->local_stype = L2CAP_SERV_BESTEFFORT;
627 chan->local_msdu = L2CAP_DEFAULT_MAX_SDU_SIZE;
628 chan->local_sdu_itime = L2CAP_DEFAULT_SDU_ITIME;
629 chan->local_acc_lat = L2CAP_DEFAULT_ACC_LAT;
630 chan->local_flush_to = L2CAP_EFS_DEFAULT_FLUSH_TO;
631
632 l2cap_chan_hold(chan);
633
634 /* Only keep a reference for fixed channels if they requested it */
635 if (chan->chan_type != L2CAP_CHAN_FIXED ||
636 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
637 hci_conn_hold(conn->hcon);
638
639 /* Append to the list since the order matters for ECRED */
640 list_add_tail(&chan->list, &conn->chan_l);
641}
642
643void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
644{
645 mutex_lock(&conn->chan_lock);
646 __l2cap_chan_add(conn, chan);
647 mutex_unlock(&conn->chan_lock);
648}
649
650void l2cap_chan_del(struct l2cap_chan *chan, int err)
651{
652 struct l2cap_conn *conn = chan->conn;
653
654 __clear_chan_timer(chan);
655
656 BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err,
657 state_to_string(chan->state));
658
659 chan->ops->teardown(chan, err);
660
661 if (conn) {
662 /* Delete from channel list */
663 list_del(&chan->list);
664
665 l2cap_chan_put(chan);
666
667 chan->conn = NULL;
668
669 /* Reference was only held for non-fixed channels or
670 * fixed channels that explicitly requested it using the
671 * FLAG_HOLD_HCI_CONN flag.
672 */
673 if (chan->chan_type != L2CAP_CHAN_FIXED ||
674 test_bit(FLAG_HOLD_HCI_CONN, &chan->flags))
675 hci_conn_drop(conn->hcon);
676 }
677
678 if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state))
679 return;
680
681 switch (chan->mode) {
682 case L2CAP_MODE_BASIC:
683 break;
684
685 case L2CAP_MODE_LE_FLOWCTL:
686 case L2CAP_MODE_EXT_FLOWCTL:
687 skb_queue_purge(&chan->tx_q);
688 break;
689
690 case L2CAP_MODE_ERTM:
691 __clear_retrans_timer(chan);
692 __clear_monitor_timer(chan);
693 __clear_ack_timer(chan);
694
695 skb_queue_purge(&chan->srej_q);
696
697 l2cap_seq_list_free(&chan->srej_list);
698 l2cap_seq_list_free(&chan->retrans_list);
699 fallthrough;
700
701 case L2CAP_MODE_STREAMING:
702 skb_queue_purge(&chan->tx_q);
703 break;
704 }
705}
706EXPORT_SYMBOL_GPL(l2cap_chan_del);
707
708static void __l2cap_chan_list_id(struct l2cap_conn *conn, u16 id,
709 l2cap_chan_func_t func, void *data)
710{
711 struct l2cap_chan *chan, *l;
712
713 list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
714 if (chan->ident == id)
715 func(chan, data);
716 }
717}
718
719static void __l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
720 void *data)
721{
722 struct l2cap_chan *chan;
723
724 list_for_each_entry(chan, &conn->chan_l, list) {
725 func(chan, data);
726 }
727}
728
729void l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
730 void *data)
731{
732 if (!conn)
733 return;
734
735 mutex_lock(&conn->chan_lock);
736 __l2cap_chan_list(conn, func, data);
737 mutex_unlock(&conn->chan_lock);
738}
739
740EXPORT_SYMBOL_GPL(l2cap_chan_list);
741
742static void l2cap_conn_update_id_addr(struct work_struct *work)
743{
744 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
745 id_addr_timer.work);
746 struct hci_conn *hcon = conn->hcon;
747 struct l2cap_chan *chan;
748
749 mutex_lock(&conn->chan_lock);
750
751 list_for_each_entry(chan, &conn->chan_l, list) {
752 l2cap_chan_lock(chan);
753 bacpy(&chan->dst, &hcon->dst);
754 chan->dst_type = bdaddr_dst_type(hcon);
755 l2cap_chan_unlock(chan);
756 }
757
758 mutex_unlock(&conn->chan_lock);
759}
760
761static void l2cap_chan_le_connect_reject(struct l2cap_chan *chan)
762{
763 struct l2cap_conn *conn = chan->conn;
764 struct l2cap_le_conn_rsp rsp;
765 u16 result;
766
767 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
768 result = L2CAP_CR_LE_AUTHORIZATION;
769 else
770 result = L2CAP_CR_LE_BAD_PSM;
771
772 l2cap_state_change(chan, BT_DISCONN);
773
774 rsp.dcid = cpu_to_le16(chan->scid);
775 rsp.mtu = cpu_to_le16(chan->imtu);
776 rsp.mps = cpu_to_le16(chan->mps);
777 rsp.credits = cpu_to_le16(chan->rx_credits);
778 rsp.result = cpu_to_le16(result);
779
780 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
781 &rsp);
782}
783
784static void l2cap_chan_ecred_connect_reject(struct l2cap_chan *chan)
785{
786 l2cap_state_change(chan, BT_DISCONN);
787
788 __l2cap_ecred_conn_rsp_defer(chan);
789}
790
791static void l2cap_chan_connect_reject(struct l2cap_chan *chan)
792{
793 struct l2cap_conn *conn = chan->conn;
794 struct l2cap_conn_rsp rsp;
795 u16 result;
796
797 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
798 result = L2CAP_CR_SEC_BLOCK;
799 else
800 result = L2CAP_CR_BAD_PSM;
801
802 l2cap_state_change(chan, BT_DISCONN);
803
804 rsp.scid = cpu_to_le16(chan->dcid);
805 rsp.dcid = cpu_to_le16(chan->scid);
806 rsp.result = cpu_to_le16(result);
807 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
808
809 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP, sizeof(rsp), &rsp);
810}
811
812void l2cap_chan_close(struct l2cap_chan *chan, int reason)
813{
814 struct l2cap_conn *conn = chan->conn;
815
816 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
817
818 switch (chan->state) {
819 case BT_LISTEN:
820 chan->ops->teardown(chan, 0);
821 break;
822
823 case BT_CONNECTED:
824 case BT_CONFIG:
825 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
826 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
827 l2cap_send_disconn_req(chan, reason);
828 } else
829 l2cap_chan_del(chan, reason);
830 break;
831
832 case BT_CONNECT2:
833 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) {
834 if (conn->hcon->type == ACL_LINK)
835 l2cap_chan_connect_reject(chan);
836 else if (conn->hcon->type == LE_LINK) {
837 switch (chan->mode) {
838 case L2CAP_MODE_LE_FLOWCTL:
839 l2cap_chan_le_connect_reject(chan);
840 break;
841 case L2CAP_MODE_EXT_FLOWCTL:
842 l2cap_chan_ecred_connect_reject(chan);
843 return;
844 }
845 }
846 }
847
848 l2cap_chan_del(chan, reason);
849 break;
850
851 case BT_CONNECT:
852 case BT_DISCONN:
853 l2cap_chan_del(chan, reason);
854 break;
855
856 default:
857 chan->ops->teardown(chan, 0);
858 break;
859 }
860}
861EXPORT_SYMBOL(l2cap_chan_close);
862
863static inline u8 l2cap_get_auth_type(struct l2cap_chan *chan)
864{
865 switch (chan->chan_type) {
866 case L2CAP_CHAN_RAW:
867 switch (chan->sec_level) {
868 case BT_SECURITY_HIGH:
869 case BT_SECURITY_FIPS:
870 return HCI_AT_DEDICATED_BONDING_MITM;
871 case BT_SECURITY_MEDIUM:
872 return HCI_AT_DEDICATED_BONDING;
873 default:
874 return HCI_AT_NO_BONDING;
875 }
876 break;
877 case L2CAP_CHAN_CONN_LESS:
878 if (chan->psm == cpu_to_le16(L2CAP_PSM_3DSP)) {
879 if (chan->sec_level == BT_SECURITY_LOW)
880 chan->sec_level = BT_SECURITY_SDP;
881 }
882 if (chan->sec_level == BT_SECURITY_HIGH ||
883 chan->sec_level == BT_SECURITY_FIPS)
884 return HCI_AT_NO_BONDING_MITM;
885 else
886 return HCI_AT_NO_BONDING;
887 break;
888 case L2CAP_CHAN_CONN_ORIENTED:
889 if (chan->psm == cpu_to_le16(L2CAP_PSM_SDP)) {
890 if (chan->sec_level == BT_SECURITY_LOW)
891 chan->sec_level = BT_SECURITY_SDP;
892
893 if (chan->sec_level == BT_SECURITY_HIGH ||
894 chan->sec_level == BT_SECURITY_FIPS)
895 return HCI_AT_NO_BONDING_MITM;
896 else
897 return HCI_AT_NO_BONDING;
898 }
899 fallthrough;
900
901 default:
902 switch (chan->sec_level) {
903 case BT_SECURITY_HIGH:
904 case BT_SECURITY_FIPS:
905 return HCI_AT_GENERAL_BONDING_MITM;
906 case BT_SECURITY_MEDIUM:
907 return HCI_AT_GENERAL_BONDING;
908 default:
909 return HCI_AT_NO_BONDING;
910 }
911 break;
912 }
913}
914
915/* Service level security */
916int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator)
917{
918 struct l2cap_conn *conn = chan->conn;
919 __u8 auth_type;
920
921 if (conn->hcon->type == LE_LINK)
922 return smp_conn_security(conn->hcon, chan->sec_level);
923
924 auth_type = l2cap_get_auth_type(chan);
925
926 return hci_conn_security(conn->hcon, chan->sec_level, auth_type,
927 initiator);
928}
929
930static u8 l2cap_get_ident(struct l2cap_conn *conn)
931{
932 u8 id;
933
934 /* Get next available identificator.
935 * 1 - 128 are used by kernel.
936 * 129 - 199 are reserved.
937 * 200 - 254 are used by utilities like l2ping, etc.
938 */
939
940 mutex_lock(&conn->ident_lock);
941
942 if (++conn->tx_ident > 128)
943 conn->tx_ident = 1;
944
945 id = conn->tx_ident;
946
947 mutex_unlock(&conn->ident_lock);
948
949 return id;
950}
951
952static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len,
953 void *data)
954{
955 struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data);
956 u8 flags;
957
958 BT_DBG("code 0x%2.2x", code);
959
960 if (!skb)
961 return;
962
963 /* Use NO_FLUSH if supported or we have an LE link (which does
964 * not support auto-flushing packets) */
965 if (lmp_no_flush_capable(conn->hcon->hdev) ||
966 conn->hcon->type == LE_LINK)
967 flags = ACL_START_NO_FLUSH;
968 else
969 flags = ACL_START;
970
971 bt_cb(skb)->force_active = BT_POWER_FORCE_ACTIVE_ON;
972 skb->priority = HCI_PRIO_MAX;
973
974 hci_send_acl(conn->hchan, skb, flags);
975}
976
977static void l2cap_do_send(struct l2cap_chan *chan, struct sk_buff *skb)
978{
979 struct hci_conn *hcon = chan->conn->hcon;
980 u16 flags;
981
982 BT_DBG("chan %p, skb %p len %d priority %u", chan, skb, skb->len,
983 skb->priority);
984
985 /* Use NO_FLUSH for LE links (where this is the only option) or
986 * if the BR/EDR link supports it and flushing has not been
987 * explicitly requested (through FLAG_FLUSHABLE).
988 */
989 if (hcon->type == LE_LINK ||
990 (!test_bit(FLAG_FLUSHABLE, &chan->flags) &&
991 lmp_no_flush_capable(hcon->hdev)))
992 flags = ACL_START_NO_FLUSH;
993 else
994 flags = ACL_START;
995
996 bt_cb(skb)->force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags);
997 hci_send_acl(chan->conn->hchan, skb, flags);
998}
999
1000static void __unpack_enhanced_control(u16 enh, struct l2cap_ctrl *control)
1001{
1002 control->reqseq = (enh & L2CAP_CTRL_REQSEQ) >> L2CAP_CTRL_REQSEQ_SHIFT;
1003 control->final = (enh & L2CAP_CTRL_FINAL) >> L2CAP_CTRL_FINAL_SHIFT;
1004
1005 if (enh & L2CAP_CTRL_FRAME_TYPE) {
1006 /* S-Frame */
1007 control->sframe = 1;
1008 control->poll = (enh & L2CAP_CTRL_POLL) >> L2CAP_CTRL_POLL_SHIFT;
1009 control->super = (enh & L2CAP_CTRL_SUPERVISE) >> L2CAP_CTRL_SUPER_SHIFT;
1010
1011 control->sar = 0;
1012 control->txseq = 0;
1013 } else {
1014 /* I-Frame */
1015 control->sframe = 0;
1016 control->sar = (enh & L2CAP_CTRL_SAR) >> L2CAP_CTRL_SAR_SHIFT;
1017 control->txseq = (enh & L2CAP_CTRL_TXSEQ) >> L2CAP_CTRL_TXSEQ_SHIFT;
1018
1019 control->poll = 0;
1020 control->super = 0;
1021 }
1022}
1023
1024static void __unpack_extended_control(u32 ext, struct l2cap_ctrl *control)
1025{
1026 control->reqseq = (ext & L2CAP_EXT_CTRL_REQSEQ) >> L2CAP_EXT_CTRL_REQSEQ_SHIFT;
1027 control->final = (ext & L2CAP_EXT_CTRL_FINAL) >> L2CAP_EXT_CTRL_FINAL_SHIFT;
1028
1029 if (ext & L2CAP_EXT_CTRL_FRAME_TYPE) {
1030 /* S-Frame */
1031 control->sframe = 1;
1032 control->poll = (ext & L2CAP_EXT_CTRL_POLL) >> L2CAP_EXT_CTRL_POLL_SHIFT;
1033 control->super = (ext & L2CAP_EXT_CTRL_SUPERVISE) >> L2CAP_EXT_CTRL_SUPER_SHIFT;
1034
1035 control->sar = 0;
1036 control->txseq = 0;
1037 } else {
1038 /* I-Frame */
1039 control->sframe = 0;
1040 control->sar = (ext & L2CAP_EXT_CTRL_SAR) >> L2CAP_EXT_CTRL_SAR_SHIFT;
1041 control->txseq = (ext & L2CAP_EXT_CTRL_TXSEQ) >> L2CAP_EXT_CTRL_TXSEQ_SHIFT;
1042
1043 control->poll = 0;
1044 control->super = 0;
1045 }
1046}
1047
1048static inline void __unpack_control(struct l2cap_chan *chan,
1049 struct sk_buff *skb)
1050{
1051 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
1052 __unpack_extended_control(get_unaligned_le32(skb->data),
1053 &bt_cb(skb)->l2cap);
1054 skb_pull(skb, L2CAP_EXT_CTRL_SIZE);
1055 } else {
1056 __unpack_enhanced_control(get_unaligned_le16(skb->data),
1057 &bt_cb(skb)->l2cap);
1058 skb_pull(skb, L2CAP_ENH_CTRL_SIZE);
1059 }
1060}
1061
1062static u32 __pack_extended_control(struct l2cap_ctrl *control)
1063{
1064 u32 packed;
1065
1066 packed = control->reqseq << L2CAP_EXT_CTRL_REQSEQ_SHIFT;
1067 packed |= control->final << L2CAP_EXT_CTRL_FINAL_SHIFT;
1068
1069 if (control->sframe) {
1070 packed |= control->poll << L2CAP_EXT_CTRL_POLL_SHIFT;
1071 packed |= control->super << L2CAP_EXT_CTRL_SUPER_SHIFT;
1072 packed |= L2CAP_EXT_CTRL_FRAME_TYPE;
1073 } else {
1074 packed |= control->sar << L2CAP_EXT_CTRL_SAR_SHIFT;
1075 packed |= control->txseq << L2CAP_EXT_CTRL_TXSEQ_SHIFT;
1076 }
1077
1078 return packed;
1079}
1080
1081static u16 __pack_enhanced_control(struct l2cap_ctrl *control)
1082{
1083 u16 packed;
1084
1085 packed = control->reqseq << L2CAP_CTRL_REQSEQ_SHIFT;
1086 packed |= control->final << L2CAP_CTRL_FINAL_SHIFT;
1087
1088 if (control->sframe) {
1089 packed |= control->poll << L2CAP_CTRL_POLL_SHIFT;
1090 packed |= control->super << L2CAP_CTRL_SUPER_SHIFT;
1091 packed |= L2CAP_CTRL_FRAME_TYPE;
1092 } else {
1093 packed |= control->sar << L2CAP_CTRL_SAR_SHIFT;
1094 packed |= control->txseq << L2CAP_CTRL_TXSEQ_SHIFT;
1095 }
1096
1097 return packed;
1098}
1099
1100static inline void __pack_control(struct l2cap_chan *chan,
1101 struct l2cap_ctrl *control,
1102 struct sk_buff *skb)
1103{
1104 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
1105 put_unaligned_le32(__pack_extended_control(control),
1106 skb->data + L2CAP_HDR_SIZE);
1107 } else {
1108 put_unaligned_le16(__pack_enhanced_control(control),
1109 skb->data + L2CAP_HDR_SIZE);
1110 }
1111}
1112
1113static inline unsigned int __ertm_hdr_size(struct l2cap_chan *chan)
1114{
1115 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1116 return L2CAP_EXT_HDR_SIZE;
1117 else
1118 return L2CAP_ENH_HDR_SIZE;
1119}
1120
1121static struct sk_buff *l2cap_create_sframe_pdu(struct l2cap_chan *chan,
1122 u32 control)
1123{
1124 struct sk_buff *skb;
1125 struct l2cap_hdr *lh;
1126 int hlen = __ertm_hdr_size(chan);
1127
1128 if (chan->fcs == L2CAP_FCS_CRC16)
1129 hlen += L2CAP_FCS_SIZE;
1130
1131 skb = bt_skb_alloc(hlen, GFP_KERNEL);
1132
1133 if (!skb)
1134 return ERR_PTR(-ENOMEM);
1135
1136 lh = skb_put(skb, L2CAP_HDR_SIZE);
1137 lh->len = cpu_to_le16(hlen - L2CAP_HDR_SIZE);
1138 lh->cid = cpu_to_le16(chan->dcid);
1139
1140 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1141 put_unaligned_le32(control, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
1142 else
1143 put_unaligned_le16(control, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
1144
1145 if (chan->fcs == L2CAP_FCS_CRC16) {
1146 u16 fcs = crc16(0, (u8 *)skb->data, skb->len);
1147 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1148 }
1149
1150 skb->priority = HCI_PRIO_MAX;
1151 return skb;
1152}
1153
1154static void l2cap_send_sframe(struct l2cap_chan *chan,
1155 struct l2cap_ctrl *control)
1156{
1157 struct sk_buff *skb;
1158 u32 control_field;
1159
1160 BT_DBG("chan %p, control %p", chan, control);
1161
1162 if (!control->sframe)
1163 return;
1164
1165 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state) &&
1166 !control->poll)
1167 control->final = 1;
1168
1169 if (control->super == L2CAP_SUPER_RR)
1170 clear_bit(CONN_RNR_SENT, &chan->conn_state);
1171 else if (control->super == L2CAP_SUPER_RNR)
1172 set_bit(CONN_RNR_SENT, &chan->conn_state);
1173
1174 if (control->super != L2CAP_SUPER_SREJ) {
1175 chan->last_acked_seq = control->reqseq;
1176 __clear_ack_timer(chan);
1177 }
1178
1179 BT_DBG("reqseq %d, final %d, poll %d, super %d", control->reqseq,
1180 control->final, control->poll, control->super);
1181
1182 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
1183 control_field = __pack_extended_control(control);
1184 else
1185 control_field = __pack_enhanced_control(control);
1186
1187 skb = l2cap_create_sframe_pdu(chan, control_field);
1188 if (!IS_ERR(skb))
1189 l2cap_do_send(chan, skb);
1190}
1191
1192static void l2cap_send_rr_or_rnr(struct l2cap_chan *chan, bool poll)
1193{
1194 struct l2cap_ctrl control;
1195
1196 BT_DBG("chan %p, poll %d", chan, poll);
1197
1198 memset(&control, 0, sizeof(control));
1199 control.sframe = 1;
1200 control.poll = poll;
1201
1202 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
1203 control.super = L2CAP_SUPER_RNR;
1204 else
1205 control.super = L2CAP_SUPER_RR;
1206
1207 control.reqseq = chan->buffer_seq;
1208 l2cap_send_sframe(chan, &control);
1209}
1210
1211static inline int __l2cap_no_conn_pending(struct l2cap_chan *chan)
1212{
1213 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
1214 return true;
1215
1216 return !test_bit(CONF_CONNECT_PEND, &chan->conf_state);
1217}
1218
1219void l2cap_send_conn_req(struct l2cap_chan *chan)
1220{
1221 struct l2cap_conn *conn = chan->conn;
1222 struct l2cap_conn_req req;
1223
1224 req.scid = cpu_to_le16(chan->scid);
1225 req.psm = chan->psm;
1226
1227 chan->ident = l2cap_get_ident(conn);
1228
1229 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
1230
1231 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_REQ, sizeof(req), &req);
1232}
1233
1234static void l2cap_chan_ready(struct l2cap_chan *chan)
1235{
1236 /* The channel may have already been flagged as connected in
1237 * case of receiving data before the L2CAP info req/rsp
1238 * procedure is complete.
1239 */
1240 if (chan->state == BT_CONNECTED)
1241 return;
1242
1243 /* This clears all conf flags, including CONF_NOT_COMPLETE */
1244 chan->conf_state = 0;
1245 __clear_chan_timer(chan);
1246
1247 switch (chan->mode) {
1248 case L2CAP_MODE_LE_FLOWCTL:
1249 case L2CAP_MODE_EXT_FLOWCTL:
1250 if (!chan->tx_credits)
1251 chan->ops->suspend(chan);
1252 break;
1253 }
1254
1255 chan->state = BT_CONNECTED;
1256
1257 chan->ops->ready(chan);
1258}
1259
1260static void l2cap_le_connect(struct l2cap_chan *chan)
1261{
1262 struct l2cap_conn *conn = chan->conn;
1263 struct l2cap_le_conn_req req;
1264
1265 if (test_and_set_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags))
1266 return;
1267
1268 if (!chan->imtu)
1269 chan->imtu = chan->conn->mtu;
1270
1271 l2cap_le_flowctl_init(chan, 0);
1272
1273 memset(&req, 0, sizeof(req));
1274 req.psm = chan->psm;
1275 req.scid = cpu_to_le16(chan->scid);
1276 req.mtu = cpu_to_le16(chan->imtu);
1277 req.mps = cpu_to_le16(chan->mps);
1278 req.credits = cpu_to_le16(chan->rx_credits);
1279
1280 chan->ident = l2cap_get_ident(conn);
1281
1282 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_REQ,
1283 sizeof(req), &req);
1284}
1285
1286struct l2cap_ecred_conn_data {
1287 struct {
1288 struct l2cap_ecred_conn_req_hdr req;
1289 __le16 scid[5];
1290 } __packed pdu;
1291 struct l2cap_chan *chan;
1292 struct pid *pid;
1293 int count;
1294};
1295
1296static void l2cap_ecred_defer_connect(struct l2cap_chan *chan, void *data)
1297{
1298 struct l2cap_ecred_conn_data *conn = data;
1299 struct pid *pid;
1300
1301 if (chan == conn->chan)
1302 return;
1303
1304 if (!test_and_clear_bit(FLAG_DEFER_SETUP, &chan->flags))
1305 return;
1306
1307 pid = chan->ops->get_peer_pid(chan);
1308
1309 /* Only add deferred channels with the same PID/PSM */
1310 if (conn->pid != pid || chan->psm != conn->chan->psm || chan->ident ||
1311 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
1312 return;
1313
1314 if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
1315 return;
1316
1317 l2cap_ecred_init(chan, 0);
1318
1319 /* Set the same ident so we can match on the rsp */
1320 chan->ident = conn->chan->ident;
1321
1322 /* Include all channels deferred */
1323 conn->pdu.scid[conn->count] = cpu_to_le16(chan->scid);
1324
1325 conn->count++;
1326}
1327
1328static void l2cap_ecred_connect(struct l2cap_chan *chan)
1329{
1330 struct l2cap_conn *conn = chan->conn;
1331 struct l2cap_ecred_conn_data data;
1332
1333 if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
1334 return;
1335
1336 if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
1337 return;
1338
1339 l2cap_ecred_init(chan, 0);
1340
1341 memset(&data, 0, sizeof(data));
1342 data.pdu.req.psm = chan->psm;
1343 data.pdu.req.mtu = cpu_to_le16(chan->imtu);
1344 data.pdu.req.mps = cpu_to_le16(chan->mps);
1345 data.pdu.req.credits = cpu_to_le16(chan->rx_credits);
1346 data.pdu.scid[0] = cpu_to_le16(chan->scid);
1347
1348 chan->ident = l2cap_get_ident(conn);
1349
1350 data.count = 1;
1351 data.chan = chan;
1352 data.pid = chan->ops->get_peer_pid(chan);
1353
1354 __l2cap_chan_list(conn, l2cap_ecred_defer_connect, &data);
1355
1356 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_CONN_REQ,
1357 sizeof(data.pdu.req) + data.count * sizeof(__le16),
1358 &data.pdu);
1359}
1360
1361static void l2cap_le_start(struct l2cap_chan *chan)
1362{
1363 struct l2cap_conn *conn = chan->conn;
1364
1365 if (!smp_conn_security(conn->hcon, chan->sec_level))
1366 return;
1367
1368 if (!chan->psm) {
1369 l2cap_chan_ready(chan);
1370 return;
1371 }
1372
1373 if (chan->state == BT_CONNECT) {
1374 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL)
1375 l2cap_ecred_connect(chan);
1376 else
1377 l2cap_le_connect(chan);
1378 }
1379}
1380
1381static void l2cap_start_connection(struct l2cap_chan *chan)
1382{
1383 if (chan->conn->hcon->type == LE_LINK) {
1384 l2cap_le_start(chan);
1385 } else {
1386 l2cap_send_conn_req(chan);
1387 }
1388}
1389
1390static void l2cap_request_info(struct l2cap_conn *conn)
1391{
1392 struct l2cap_info_req req;
1393
1394 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1395 return;
1396
1397 req.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
1398
1399 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
1400 conn->info_ident = l2cap_get_ident(conn);
1401
1402 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
1403
1404 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
1405 sizeof(req), &req);
1406}
1407
1408static bool l2cap_check_enc_key_size(struct hci_conn *hcon)
1409{
1410 /* The minimum encryption key size needs to be enforced by the
1411 * host stack before establishing any L2CAP connections. The
1412 * specification in theory allows a minimum of 1, but to align
1413 * BR/EDR and LE transports, a minimum of 7 is chosen.
1414 *
1415 * This check might also be called for unencrypted connections
1416 * that have no key size requirements. Ensure that the link is
1417 * actually encrypted before enforcing a key size.
1418 */
1419 int min_key_size = hcon->hdev->min_enc_key_size;
1420
1421 /* On FIPS security level, key size must be 16 bytes */
1422 if (hcon->sec_level == BT_SECURITY_FIPS)
1423 min_key_size = 16;
1424
1425 return (!test_bit(HCI_CONN_ENCRYPT, &hcon->flags) ||
1426 hcon->enc_key_size >= min_key_size);
1427}
1428
1429static void l2cap_do_start(struct l2cap_chan *chan)
1430{
1431 struct l2cap_conn *conn = chan->conn;
1432
1433 if (conn->hcon->type == LE_LINK) {
1434 l2cap_le_start(chan);
1435 return;
1436 }
1437
1438 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)) {
1439 l2cap_request_info(conn);
1440 return;
1441 }
1442
1443 if (!(conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE))
1444 return;
1445
1446 if (!l2cap_chan_check_security(chan, true) ||
1447 !__l2cap_no_conn_pending(chan))
1448 return;
1449
1450 if (l2cap_check_enc_key_size(conn->hcon))
1451 l2cap_start_connection(chan);
1452 else
1453 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
1454}
1455
1456static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
1457{
1458 u32 local_feat_mask = l2cap_feat_mask;
1459 if (!disable_ertm)
1460 local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
1461
1462 switch (mode) {
1463 case L2CAP_MODE_ERTM:
1464 return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
1465 case L2CAP_MODE_STREAMING:
1466 return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
1467 default:
1468 return 0x00;
1469 }
1470}
1471
1472static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err)
1473{
1474 struct l2cap_conn *conn = chan->conn;
1475 struct l2cap_disconn_req req;
1476
1477 if (!conn)
1478 return;
1479
1480 if (chan->mode == L2CAP_MODE_ERTM && chan->state == BT_CONNECTED) {
1481 __clear_retrans_timer(chan);
1482 __clear_monitor_timer(chan);
1483 __clear_ack_timer(chan);
1484 }
1485
1486 req.dcid = cpu_to_le16(chan->dcid);
1487 req.scid = cpu_to_le16(chan->scid);
1488 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_DISCONN_REQ,
1489 sizeof(req), &req);
1490
1491 l2cap_state_change_and_error(chan, BT_DISCONN, err);
1492}
1493
1494/* ---- L2CAP connections ---- */
1495static void l2cap_conn_start(struct l2cap_conn *conn)
1496{
1497 struct l2cap_chan *chan, *tmp;
1498
1499 BT_DBG("conn %p", conn);
1500
1501 mutex_lock(&conn->chan_lock);
1502
1503 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
1504 l2cap_chan_lock(chan);
1505
1506 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1507 l2cap_chan_ready(chan);
1508 l2cap_chan_unlock(chan);
1509 continue;
1510 }
1511
1512 if (chan->state == BT_CONNECT) {
1513 if (!l2cap_chan_check_security(chan, true) ||
1514 !__l2cap_no_conn_pending(chan)) {
1515 l2cap_chan_unlock(chan);
1516 continue;
1517 }
1518
1519 if (!l2cap_mode_supported(chan->mode, conn->feat_mask)
1520 && test_bit(CONF_STATE2_DEVICE,
1521 &chan->conf_state)) {
1522 l2cap_chan_close(chan, ECONNRESET);
1523 l2cap_chan_unlock(chan);
1524 continue;
1525 }
1526
1527 if (l2cap_check_enc_key_size(conn->hcon))
1528 l2cap_start_connection(chan);
1529 else
1530 l2cap_chan_close(chan, ECONNREFUSED);
1531
1532 } else if (chan->state == BT_CONNECT2) {
1533 struct l2cap_conn_rsp rsp;
1534 char buf[128];
1535 rsp.scid = cpu_to_le16(chan->dcid);
1536 rsp.dcid = cpu_to_le16(chan->scid);
1537
1538 if (l2cap_chan_check_security(chan, false)) {
1539 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
1540 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1541 rsp.status = cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
1542 chan->ops->defer(chan);
1543
1544 } else {
1545 l2cap_state_change(chan, BT_CONFIG);
1546 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
1547 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
1548 }
1549 } else {
1550 rsp.result = cpu_to_le16(L2CAP_CR_PEND);
1551 rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
1552 }
1553
1554 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
1555 sizeof(rsp), &rsp);
1556
1557 if (test_bit(CONF_REQ_SENT, &chan->conf_state) ||
1558 rsp.result != L2CAP_CR_SUCCESS) {
1559 l2cap_chan_unlock(chan);
1560 continue;
1561 }
1562
1563 set_bit(CONF_REQ_SENT, &chan->conf_state);
1564 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
1565 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
1566 chan->num_conf_req++;
1567 }
1568
1569 l2cap_chan_unlock(chan);
1570 }
1571
1572 mutex_unlock(&conn->chan_lock);
1573}
1574
1575static void l2cap_le_conn_ready(struct l2cap_conn *conn)
1576{
1577 struct hci_conn *hcon = conn->hcon;
1578 struct hci_dev *hdev = hcon->hdev;
1579
1580 BT_DBG("%s conn %p", hdev->name, conn);
1581
1582 /* For outgoing pairing which doesn't necessarily have an
1583 * associated socket (e.g. mgmt_pair_device).
1584 */
1585 if (hcon->out)
1586 smp_conn_security(hcon, hcon->pending_sec_level);
1587
1588 /* For LE peripheral connections, make sure the connection interval
1589 * is in the range of the minimum and maximum interval that has
1590 * been configured for this connection. If not, then trigger
1591 * the connection update procedure.
1592 */
1593 if (hcon->role == HCI_ROLE_SLAVE &&
1594 (hcon->le_conn_interval < hcon->le_conn_min_interval ||
1595 hcon->le_conn_interval > hcon->le_conn_max_interval)) {
1596 struct l2cap_conn_param_update_req req;
1597
1598 req.min = cpu_to_le16(hcon->le_conn_min_interval);
1599 req.max = cpu_to_le16(hcon->le_conn_max_interval);
1600 req.latency = cpu_to_le16(hcon->le_conn_latency);
1601 req.to_multiplier = cpu_to_le16(hcon->le_supv_timeout);
1602
1603 l2cap_send_cmd(conn, l2cap_get_ident(conn),
1604 L2CAP_CONN_PARAM_UPDATE_REQ, sizeof(req), &req);
1605 }
1606}
1607
1608static void l2cap_conn_ready(struct l2cap_conn *conn)
1609{
1610 struct l2cap_chan *chan;
1611 struct hci_conn *hcon = conn->hcon;
1612
1613 BT_DBG("conn %p", conn);
1614
1615 if (hcon->type == ACL_LINK)
1616 l2cap_request_info(conn);
1617
1618 mutex_lock(&conn->chan_lock);
1619
1620 list_for_each_entry(chan, &conn->chan_l, list) {
1621
1622 l2cap_chan_lock(chan);
1623
1624 if (hcon->type == LE_LINK) {
1625 l2cap_le_start(chan);
1626 } else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1627 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
1628 l2cap_chan_ready(chan);
1629 } else if (chan->state == BT_CONNECT) {
1630 l2cap_do_start(chan);
1631 }
1632
1633 l2cap_chan_unlock(chan);
1634 }
1635
1636 mutex_unlock(&conn->chan_lock);
1637
1638 if (hcon->type == LE_LINK)
1639 l2cap_le_conn_ready(conn);
1640
1641 queue_work(hcon->hdev->workqueue, &conn->pending_rx_work);
1642}
1643
1644/* Notify sockets that we cannot guaranty reliability anymore */
1645static void l2cap_conn_unreliable(struct l2cap_conn *conn, int err)
1646{
1647 struct l2cap_chan *chan;
1648
1649 BT_DBG("conn %p", conn);
1650
1651 mutex_lock(&conn->chan_lock);
1652
1653 list_for_each_entry(chan, &conn->chan_l, list) {
1654 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
1655 l2cap_chan_set_err(chan, err);
1656 }
1657
1658 mutex_unlock(&conn->chan_lock);
1659}
1660
1661static void l2cap_info_timeout(struct work_struct *work)
1662{
1663 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
1664 info_timer.work);
1665
1666 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
1667 conn->info_ident = 0;
1668
1669 l2cap_conn_start(conn);
1670}
1671
1672/*
1673 * l2cap_user
1674 * External modules can register l2cap_user objects on l2cap_conn. The ->probe
1675 * callback is called during registration. The ->remove callback is called
1676 * during unregistration.
1677 * An l2cap_user object can either be explicitly unregistered or when the
1678 * underlying l2cap_conn object is deleted. This guarantees that l2cap->hcon,
1679 * l2cap->hchan, .. are valid as long as the remove callback hasn't been called.
1680 * External modules must own a reference to the l2cap_conn object if they intend
1681 * to call l2cap_unregister_user(). The l2cap_conn object might get destroyed at
1682 * any time if they don't.
1683 */
1684
1685int l2cap_register_user(struct l2cap_conn *conn, struct l2cap_user *user)
1686{
1687 struct hci_dev *hdev = conn->hcon->hdev;
1688 int ret;
1689
1690 /* We need to check whether l2cap_conn is registered. If it is not, we
1691 * must not register the l2cap_user. l2cap_conn_del() is unregisters
1692 * l2cap_conn objects, but doesn't provide its own locking. Instead, it
1693 * relies on the parent hci_conn object to be locked. This itself relies
1694 * on the hci_dev object to be locked. So we must lock the hci device
1695 * here, too. */
1696
1697 hci_dev_lock(hdev);
1698
1699 if (!list_empty(&user->list)) {
1700 ret = -EINVAL;
1701 goto out_unlock;
1702 }
1703
1704 /* conn->hchan is NULL after l2cap_conn_del() was called */
1705 if (!conn->hchan) {
1706 ret = -ENODEV;
1707 goto out_unlock;
1708 }
1709
1710 ret = user->probe(conn, user);
1711 if (ret)
1712 goto out_unlock;
1713
1714 list_add(&user->list, &conn->users);
1715 ret = 0;
1716
1717out_unlock:
1718 hci_dev_unlock(hdev);
1719 return ret;
1720}
1721EXPORT_SYMBOL(l2cap_register_user);
1722
1723void l2cap_unregister_user(struct l2cap_conn *conn, struct l2cap_user *user)
1724{
1725 struct hci_dev *hdev = conn->hcon->hdev;
1726
1727 hci_dev_lock(hdev);
1728
1729 if (list_empty(&user->list))
1730 goto out_unlock;
1731
1732 list_del_init(&user->list);
1733 user->remove(conn, user);
1734
1735out_unlock:
1736 hci_dev_unlock(hdev);
1737}
1738EXPORT_SYMBOL(l2cap_unregister_user);
1739
1740static void l2cap_unregister_all_users(struct l2cap_conn *conn)
1741{
1742 struct l2cap_user *user;
1743
1744 while (!list_empty(&conn->users)) {
1745 user = list_first_entry(&conn->users, struct l2cap_user, list);
1746 list_del_init(&user->list);
1747 user->remove(conn, user);
1748 }
1749}
1750
1751static void l2cap_conn_del(struct hci_conn *hcon, int err)
1752{
1753 struct l2cap_conn *conn = hcon->l2cap_data;
1754 struct l2cap_chan *chan, *l;
1755
1756 if (!conn)
1757 return;
1758
1759 BT_DBG("hcon %p conn %p, err %d", hcon, conn, err);
1760
1761 kfree_skb(conn->rx_skb);
1762
1763 skb_queue_purge(&conn->pending_rx);
1764
1765 /* We can not call flush_work(&conn->pending_rx_work) here since we
1766 * might block if we are running on a worker from the same workqueue
1767 * pending_rx_work is waiting on.
1768 */
1769 if (work_pending(&conn->pending_rx_work))
1770 cancel_work_sync(&conn->pending_rx_work);
1771
1772 cancel_delayed_work_sync(&conn->id_addr_timer);
1773
1774 l2cap_unregister_all_users(conn);
1775
1776 /* Force the connection to be immediately dropped */
1777 hcon->disc_timeout = 0;
1778
1779 mutex_lock(&conn->chan_lock);
1780
1781 /* Kill channels */
1782 list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
1783 l2cap_chan_hold(chan);
1784 l2cap_chan_lock(chan);
1785
1786 l2cap_chan_del(chan, err);
1787
1788 chan->ops->close(chan);
1789
1790 l2cap_chan_unlock(chan);
1791 l2cap_chan_put(chan);
1792 }
1793
1794 mutex_unlock(&conn->chan_lock);
1795
1796 hci_chan_del(conn->hchan);
1797
1798 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT)
1799 cancel_delayed_work_sync(&conn->info_timer);
1800
1801 hcon->l2cap_data = NULL;
1802 conn->hchan = NULL;
1803 l2cap_conn_put(conn);
1804}
1805
1806static void l2cap_conn_free(struct kref *ref)
1807{
1808 struct l2cap_conn *conn = container_of(ref, struct l2cap_conn, ref);
1809
1810 hci_conn_put(conn->hcon);
1811 kfree(conn);
1812}
1813
1814struct l2cap_conn *l2cap_conn_get(struct l2cap_conn *conn)
1815{
1816 kref_get(&conn->ref);
1817 return conn;
1818}
1819EXPORT_SYMBOL(l2cap_conn_get);
1820
1821void l2cap_conn_put(struct l2cap_conn *conn)
1822{
1823 kref_put(&conn->ref, l2cap_conn_free);
1824}
1825EXPORT_SYMBOL(l2cap_conn_put);
1826
1827/* ---- Socket interface ---- */
1828
1829/* Find socket with psm and source / destination bdaddr.
1830 * Returns closest match.
1831 */
1832static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
1833 bdaddr_t *src,
1834 bdaddr_t *dst,
1835 u8 link_type)
1836{
1837 struct l2cap_chan *c, *tmp, *c1 = NULL;
1838
1839 read_lock(&chan_list_lock);
1840
1841 list_for_each_entry_safe(c, tmp, &chan_list, global_l) {
1842 if (state && c->state != state)
1843 continue;
1844
1845 if (link_type == ACL_LINK && c->src_type != BDADDR_BREDR)
1846 continue;
1847
1848 if (link_type == LE_LINK && c->src_type == BDADDR_BREDR)
1849 continue;
1850
1851 if (c->chan_type != L2CAP_CHAN_FIXED && c->psm == psm) {
1852 int src_match, dst_match;
1853 int src_any, dst_any;
1854
1855 /* Exact match. */
1856 src_match = !bacmp(&c->src, src);
1857 dst_match = !bacmp(&c->dst, dst);
1858 if (src_match && dst_match) {
1859 if (!l2cap_chan_hold_unless_zero(c))
1860 continue;
1861
1862 read_unlock(&chan_list_lock);
1863 return c;
1864 }
1865
1866 /* Closest match */
1867 src_any = !bacmp(&c->src, BDADDR_ANY);
1868 dst_any = !bacmp(&c->dst, BDADDR_ANY);
1869 if ((src_match && dst_any) || (src_any && dst_match) ||
1870 (src_any && dst_any))
1871 c1 = c;
1872 }
1873 }
1874
1875 if (c1)
1876 c1 = l2cap_chan_hold_unless_zero(c1);
1877
1878 read_unlock(&chan_list_lock);
1879
1880 return c1;
1881}
1882
1883static void l2cap_monitor_timeout(struct work_struct *work)
1884{
1885 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
1886 monitor_timer.work);
1887
1888 BT_DBG("chan %p", chan);
1889
1890 l2cap_chan_lock(chan);
1891
1892 if (!chan->conn) {
1893 l2cap_chan_unlock(chan);
1894 l2cap_chan_put(chan);
1895 return;
1896 }
1897
1898 l2cap_tx(chan, NULL, NULL, L2CAP_EV_MONITOR_TO);
1899
1900 l2cap_chan_unlock(chan);
1901 l2cap_chan_put(chan);
1902}
1903
1904static void l2cap_retrans_timeout(struct work_struct *work)
1905{
1906 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
1907 retrans_timer.work);
1908
1909 BT_DBG("chan %p", chan);
1910
1911 l2cap_chan_lock(chan);
1912
1913 if (!chan->conn) {
1914 l2cap_chan_unlock(chan);
1915 l2cap_chan_put(chan);
1916 return;
1917 }
1918
1919 l2cap_tx(chan, NULL, NULL, L2CAP_EV_RETRANS_TO);
1920 l2cap_chan_unlock(chan);
1921 l2cap_chan_put(chan);
1922}
1923
1924static void l2cap_streaming_send(struct l2cap_chan *chan,
1925 struct sk_buff_head *skbs)
1926{
1927 struct sk_buff *skb;
1928 struct l2cap_ctrl *control;
1929
1930 BT_DBG("chan %p, skbs %p", chan, skbs);
1931
1932 skb_queue_splice_tail_init(skbs, &chan->tx_q);
1933
1934 while (!skb_queue_empty(&chan->tx_q)) {
1935
1936 skb = skb_dequeue(&chan->tx_q);
1937
1938 bt_cb(skb)->l2cap.retries = 1;
1939 control = &bt_cb(skb)->l2cap;
1940
1941 control->reqseq = 0;
1942 control->txseq = chan->next_tx_seq;
1943
1944 __pack_control(chan, control, skb);
1945
1946 if (chan->fcs == L2CAP_FCS_CRC16) {
1947 u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
1948 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1949 }
1950
1951 l2cap_do_send(chan, skb);
1952
1953 BT_DBG("Sent txseq %u", control->txseq);
1954
1955 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
1956 chan->frames_sent++;
1957 }
1958}
1959
1960static int l2cap_ertm_send(struct l2cap_chan *chan)
1961{
1962 struct sk_buff *skb, *tx_skb;
1963 struct l2cap_ctrl *control;
1964 int sent = 0;
1965
1966 BT_DBG("chan %p", chan);
1967
1968 if (chan->state != BT_CONNECTED)
1969 return -ENOTCONN;
1970
1971 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
1972 return 0;
1973
1974 while (chan->tx_send_head &&
1975 chan->unacked_frames < chan->remote_tx_win &&
1976 chan->tx_state == L2CAP_TX_STATE_XMIT) {
1977
1978 skb = chan->tx_send_head;
1979
1980 bt_cb(skb)->l2cap.retries = 1;
1981 control = &bt_cb(skb)->l2cap;
1982
1983 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
1984 control->final = 1;
1985
1986 control->reqseq = chan->buffer_seq;
1987 chan->last_acked_seq = chan->buffer_seq;
1988 control->txseq = chan->next_tx_seq;
1989
1990 __pack_control(chan, control, skb);
1991
1992 if (chan->fcs == L2CAP_FCS_CRC16) {
1993 u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
1994 put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
1995 }
1996
1997 /* Clone after data has been modified. Data is assumed to be
1998 read-only (for locking purposes) on cloned sk_buffs.
1999 */
2000 tx_skb = skb_clone(skb, GFP_KERNEL);
2001
2002 if (!tx_skb)
2003 break;
2004
2005 __set_retrans_timer(chan);
2006
2007 chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
2008 chan->unacked_frames++;
2009 chan->frames_sent++;
2010 sent++;
2011
2012 if (skb_queue_is_last(&chan->tx_q, skb))
2013 chan->tx_send_head = NULL;
2014 else
2015 chan->tx_send_head = skb_queue_next(&chan->tx_q, skb);
2016
2017 l2cap_do_send(chan, tx_skb);
2018 BT_DBG("Sent txseq %u", control->txseq);
2019 }
2020
2021 BT_DBG("Sent %d, %u unacked, %u in ERTM queue", sent,
2022 chan->unacked_frames, skb_queue_len(&chan->tx_q));
2023
2024 return sent;
2025}
2026
2027static void l2cap_ertm_resend(struct l2cap_chan *chan)
2028{
2029 struct l2cap_ctrl control;
2030 struct sk_buff *skb;
2031 struct sk_buff *tx_skb;
2032 u16 seq;
2033
2034 BT_DBG("chan %p", chan);
2035
2036 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
2037 return;
2038
2039 while (chan->retrans_list.head != L2CAP_SEQ_LIST_CLEAR) {
2040 seq = l2cap_seq_list_pop(&chan->retrans_list);
2041
2042 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, seq);
2043 if (!skb) {
2044 BT_DBG("Error: Can't retransmit seq %d, frame missing",
2045 seq);
2046 continue;
2047 }
2048
2049 bt_cb(skb)->l2cap.retries++;
2050 control = bt_cb(skb)->l2cap;
2051
2052 if (chan->max_tx != 0 &&
2053 bt_cb(skb)->l2cap.retries > chan->max_tx) {
2054 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
2055 l2cap_send_disconn_req(chan, ECONNRESET);
2056 l2cap_seq_list_clear(&chan->retrans_list);
2057 break;
2058 }
2059
2060 control.reqseq = chan->buffer_seq;
2061 if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
2062 control.final = 1;
2063 else
2064 control.final = 0;
2065
2066 if (skb_cloned(skb)) {
2067 /* Cloned sk_buffs are read-only, so we need a
2068 * writeable copy
2069 */
2070 tx_skb = skb_copy(skb, GFP_KERNEL);
2071 } else {
2072 tx_skb = skb_clone(skb, GFP_KERNEL);
2073 }
2074
2075 if (!tx_skb) {
2076 l2cap_seq_list_clear(&chan->retrans_list);
2077 break;
2078 }
2079
2080 /* Update skb contents */
2081 if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
2082 put_unaligned_le32(__pack_extended_control(&control),
2083 tx_skb->data + L2CAP_HDR_SIZE);
2084 } else {
2085 put_unaligned_le16(__pack_enhanced_control(&control),
2086 tx_skb->data + L2CAP_HDR_SIZE);
2087 }
2088
2089 /* Update FCS */
2090 if (chan->fcs == L2CAP_FCS_CRC16) {
2091 u16 fcs = crc16(0, (u8 *) tx_skb->data,
2092 tx_skb->len - L2CAP_FCS_SIZE);
2093 put_unaligned_le16(fcs, skb_tail_pointer(tx_skb) -
2094 L2CAP_FCS_SIZE);
2095 }
2096
2097 l2cap_do_send(chan, tx_skb);
2098
2099 BT_DBG("Resent txseq %d", control.txseq);
2100
2101 chan->last_acked_seq = chan->buffer_seq;
2102 }
2103}
2104
2105static void l2cap_retransmit(struct l2cap_chan *chan,
2106 struct l2cap_ctrl *control)
2107{
2108 BT_DBG("chan %p, control %p", chan, control);
2109
2110 l2cap_seq_list_append(&chan->retrans_list, control->reqseq);
2111 l2cap_ertm_resend(chan);
2112}
2113
2114static void l2cap_retransmit_all(struct l2cap_chan *chan,
2115 struct l2cap_ctrl *control)
2116{
2117 struct sk_buff *skb;
2118
2119 BT_DBG("chan %p, control %p", chan, control);
2120
2121 if (control->poll)
2122 set_bit(CONN_SEND_FBIT, &chan->conn_state);
2123
2124 l2cap_seq_list_clear(&chan->retrans_list);
2125
2126 if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
2127 return;
2128
2129 if (chan->unacked_frames) {
2130 skb_queue_walk(&chan->tx_q, skb) {
2131 if (bt_cb(skb)->l2cap.txseq == control->reqseq ||
2132 skb == chan->tx_send_head)
2133 break;
2134 }
2135
2136 skb_queue_walk_from(&chan->tx_q, skb) {
2137 if (skb == chan->tx_send_head)
2138 break;
2139
2140 l2cap_seq_list_append(&chan->retrans_list,
2141 bt_cb(skb)->l2cap.txseq);
2142 }
2143
2144 l2cap_ertm_resend(chan);
2145 }
2146}
2147
2148static void l2cap_send_ack(struct l2cap_chan *chan)
2149{
2150 struct l2cap_ctrl control;
2151 u16 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
2152 chan->last_acked_seq);
2153 int threshold;
2154
2155 BT_DBG("chan %p last_acked_seq %d buffer_seq %d",
2156 chan, chan->last_acked_seq, chan->buffer_seq);
2157
2158 memset(&control, 0, sizeof(control));
2159 control.sframe = 1;
2160
2161 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
2162 chan->rx_state == L2CAP_RX_STATE_RECV) {
2163 __clear_ack_timer(chan);
2164 control.super = L2CAP_SUPER_RNR;
2165 control.reqseq = chan->buffer_seq;
2166 l2cap_send_sframe(chan, &control);
2167 } else {
2168 if (!test_bit(CONN_REMOTE_BUSY, &chan->conn_state)) {
2169 l2cap_ertm_send(chan);
2170 /* If any i-frames were sent, they included an ack */
2171 if (chan->buffer_seq == chan->last_acked_seq)
2172 frames_to_ack = 0;
2173 }
2174
2175 /* Ack now if the window is 3/4ths full.
2176 * Calculate without mul or div
2177 */
2178 threshold = chan->ack_win;
2179 threshold += threshold << 1;
2180 threshold >>= 2;
2181
2182 BT_DBG("frames_to_ack %u, threshold %d", frames_to_ack,
2183 threshold);
2184
2185 if (frames_to_ack >= threshold) {
2186 __clear_ack_timer(chan);
2187 control.super = L2CAP_SUPER_RR;
2188 control.reqseq = chan->buffer_seq;
2189 l2cap_send_sframe(chan, &control);
2190 frames_to_ack = 0;
2191 }
2192
2193 if (frames_to_ack)
2194 __set_ack_timer(chan);
2195 }
2196}
2197
2198static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
2199 struct msghdr *msg, int len,
2200 int count, struct sk_buff *skb)
2201{
2202 struct l2cap_conn *conn = chan->conn;
2203 struct sk_buff **frag;
2204 int sent = 0;
2205
2206 if (!copy_from_iter_full(skb_put(skb, count), count, &msg->msg_iter))
2207 return -EFAULT;
2208
2209 sent += count;
2210 len -= count;
2211
2212 /* Continuation fragments (no L2CAP header) */
2213 frag = &skb_shinfo(skb)->frag_list;
2214 while (len) {
2215 struct sk_buff *tmp;
2216
2217 count = min_t(unsigned int, conn->mtu, len);
2218
2219 tmp = chan->ops->alloc_skb(chan, 0, count,
2220 msg->msg_flags & MSG_DONTWAIT);
2221 if (IS_ERR(tmp))
2222 return PTR_ERR(tmp);
2223
2224 *frag = tmp;
2225
2226 if (!copy_from_iter_full(skb_put(*frag, count), count,
2227 &msg->msg_iter))
2228 return -EFAULT;
2229
2230 sent += count;
2231 len -= count;
2232
2233 skb->len += (*frag)->len;
2234 skb->data_len += (*frag)->len;
2235
2236 frag = &(*frag)->next;
2237 }
2238
2239 return sent;
2240}
2241
2242static struct sk_buff *l2cap_create_connless_pdu(struct l2cap_chan *chan,
2243 struct msghdr *msg, size_t len)
2244{
2245 struct l2cap_conn *conn = chan->conn;
2246 struct sk_buff *skb;
2247 int err, count, hlen = L2CAP_HDR_SIZE + L2CAP_PSMLEN_SIZE;
2248 struct l2cap_hdr *lh;
2249
2250 BT_DBG("chan %p psm 0x%2.2x len %zu", chan,
2251 __le16_to_cpu(chan->psm), len);
2252
2253 count = min_t(unsigned int, (conn->mtu - hlen), len);
2254
2255 skb = chan->ops->alloc_skb(chan, hlen, count,
2256 msg->msg_flags & MSG_DONTWAIT);
2257 if (IS_ERR(skb))
2258 return skb;
2259
2260 /* Create L2CAP header */
2261 lh = skb_put(skb, L2CAP_HDR_SIZE);
2262 lh->cid = cpu_to_le16(chan->dcid);
2263 lh->len = cpu_to_le16(len + L2CAP_PSMLEN_SIZE);
2264 put_unaligned(chan->psm, (__le16 *) skb_put(skb, L2CAP_PSMLEN_SIZE));
2265
2266 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2267 if (unlikely(err < 0)) {
2268 kfree_skb(skb);
2269 return ERR_PTR(err);
2270 }
2271 return skb;
2272}
2273
2274static struct sk_buff *l2cap_create_basic_pdu(struct l2cap_chan *chan,
2275 struct msghdr *msg, size_t len)
2276{
2277 struct l2cap_conn *conn = chan->conn;
2278 struct sk_buff *skb;
2279 int err, count;
2280 struct l2cap_hdr *lh;
2281
2282 BT_DBG("chan %p len %zu", chan, len);
2283
2284 count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len);
2285
2286 skb = chan->ops->alloc_skb(chan, L2CAP_HDR_SIZE, count,
2287 msg->msg_flags & MSG_DONTWAIT);
2288 if (IS_ERR(skb))
2289 return skb;
2290
2291 /* Create L2CAP header */
2292 lh = skb_put(skb, L2CAP_HDR_SIZE);
2293 lh->cid = cpu_to_le16(chan->dcid);
2294 lh->len = cpu_to_le16(len);
2295
2296 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2297 if (unlikely(err < 0)) {
2298 kfree_skb(skb);
2299 return ERR_PTR(err);
2300 }
2301 return skb;
2302}
2303
2304static struct sk_buff *l2cap_create_iframe_pdu(struct l2cap_chan *chan,
2305 struct msghdr *msg, size_t len,
2306 u16 sdulen)
2307{
2308 struct l2cap_conn *conn = chan->conn;
2309 struct sk_buff *skb;
2310 int err, count, hlen;
2311 struct l2cap_hdr *lh;
2312
2313 BT_DBG("chan %p len %zu", chan, len);
2314
2315 if (!conn)
2316 return ERR_PTR(-ENOTCONN);
2317
2318 hlen = __ertm_hdr_size(chan);
2319
2320 if (sdulen)
2321 hlen += L2CAP_SDULEN_SIZE;
2322
2323 if (chan->fcs == L2CAP_FCS_CRC16)
2324 hlen += L2CAP_FCS_SIZE;
2325
2326 count = min_t(unsigned int, (conn->mtu - hlen), len);
2327
2328 skb = chan->ops->alloc_skb(chan, hlen, count,
2329 msg->msg_flags & MSG_DONTWAIT);
2330 if (IS_ERR(skb))
2331 return skb;
2332
2333 /* Create L2CAP header */
2334 lh = skb_put(skb, L2CAP_HDR_SIZE);
2335 lh->cid = cpu_to_le16(chan->dcid);
2336 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2337
2338 /* Control header is populated later */
2339 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
2340 put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
2341 else
2342 put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
2343
2344 if (sdulen)
2345 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2346
2347 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2348 if (unlikely(err < 0)) {
2349 kfree_skb(skb);
2350 return ERR_PTR(err);
2351 }
2352
2353 bt_cb(skb)->l2cap.fcs = chan->fcs;
2354 bt_cb(skb)->l2cap.retries = 0;
2355 return skb;
2356}
2357
2358static int l2cap_segment_sdu(struct l2cap_chan *chan,
2359 struct sk_buff_head *seg_queue,
2360 struct msghdr *msg, size_t len)
2361{
2362 struct sk_buff *skb;
2363 u16 sdu_len;
2364 size_t pdu_len;
2365 u8 sar;
2366
2367 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2368
2369 /* It is critical that ERTM PDUs fit in a single HCI fragment,
2370 * so fragmented skbs are not used. The HCI layer's handling
2371 * of fragmented skbs is not compatible with ERTM's queueing.
2372 */
2373
2374 /* PDU size is derived from the HCI MTU */
2375 pdu_len = chan->conn->mtu;
2376
2377 /* Constrain PDU size for BR/EDR connections */
2378 pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD);
2379
2380 /* Adjust for largest possible L2CAP overhead. */
2381 if (chan->fcs)
2382 pdu_len -= L2CAP_FCS_SIZE;
2383
2384 pdu_len -= __ertm_hdr_size(chan);
2385
2386 /* Remote device may have requested smaller PDUs */
2387 pdu_len = min_t(size_t, pdu_len, chan->remote_mps);
2388
2389 if (len <= pdu_len) {
2390 sar = L2CAP_SAR_UNSEGMENTED;
2391 sdu_len = 0;
2392 pdu_len = len;
2393 } else {
2394 sar = L2CAP_SAR_START;
2395 sdu_len = len;
2396 }
2397
2398 while (len > 0) {
2399 skb = l2cap_create_iframe_pdu(chan, msg, pdu_len, sdu_len);
2400
2401 if (IS_ERR(skb)) {
2402 __skb_queue_purge(seg_queue);
2403 return PTR_ERR(skb);
2404 }
2405
2406 bt_cb(skb)->l2cap.sar = sar;
2407 __skb_queue_tail(seg_queue, skb);
2408
2409 len -= pdu_len;
2410 if (sdu_len)
2411 sdu_len = 0;
2412
2413 if (len <= pdu_len) {
2414 sar = L2CAP_SAR_END;
2415 pdu_len = len;
2416 } else {
2417 sar = L2CAP_SAR_CONTINUE;
2418 }
2419 }
2420
2421 return 0;
2422}
2423
2424static struct sk_buff *l2cap_create_le_flowctl_pdu(struct l2cap_chan *chan,
2425 struct msghdr *msg,
2426 size_t len, u16 sdulen)
2427{
2428 struct l2cap_conn *conn = chan->conn;
2429 struct sk_buff *skb;
2430 int err, count, hlen;
2431 struct l2cap_hdr *lh;
2432
2433 BT_DBG("chan %p len %zu", chan, len);
2434
2435 if (!conn)
2436 return ERR_PTR(-ENOTCONN);
2437
2438 hlen = L2CAP_HDR_SIZE;
2439
2440 if (sdulen)
2441 hlen += L2CAP_SDULEN_SIZE;
2442
2443 count = min_t(unsigned int, (conn->mtu - hlen), len);
2444
2445 skb = chan->ops->alloc_skb(chan, hlen, count,
2446 msg->msg_flags & MSG_DONTWAIT);
2447 if (IS_ERR(skb))
2448 return skb;
2449
2450 /* Create L2CAP header */
2451 lh = skb_put(skb, L2CAP_HDR_SIZE);
2452 lh->cid = cpu_to_le16(chan->dcid);
2453 lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
2454
2455 if (sdulen)
2456 put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
2457
2458 err = l2cap_skbuff_fromiovec(chan, msg, len, count, skb);
2459 if (unlikely(err < 0)) {
2460 kfree_skb(skb);
2461 return ERR_PTR(err);
2462 }
2463
2464 return skb;
2465}
2466
2467static int l2cap_segment_le_sdu(struct l2cap_chan *chan,
2468 struct sk_buff_head *seg_queue,
2469 struct msghdr *msg, size_t len)
2470{
2471 struct sk_buff *skb;
2472 size_t pdu_len;
2473 u16 sdu_len;
2474
2475 BT_DBG("chan %p, msg %p, len %zu", chan, msg, len);
2476
2477 sdu_len = len;
2478 pdu_len = chan->remote_mps - L2CAP_SDULEN_SIZE;
2479
2480 while (len > 0) {
2481 if (len <= pdu_len)
2482 pdu_len = len;
2483
2484 skb = l2cap_create_le_flowctl_pdu(chan, msg, pdu_len, sdu_len);
2485 if (IS_ERR(skb)) {
2486 __skb_queue_purge(seg_queue);
2487 return PTR_ERR(skb);
2488 }
2489
2490 __skb_queue_tail(seg_queue, skb);
2491
2492 len -= pdu_len;
2493
2494 if (sdu_len) {
2495 sdu_len = 0;
2496 pdu_len += L2CAP_SDULEN_SIZE;
2497 }
2498 }
2499
2500 return 0;
2501}
2502
2503static void l2cap_le_flowctl_send(struct l2cap_chan *chan)
2504{
2505 int sent = 0;
2506
2507 BT_DBG("chan %p", chan);
2508
2509 while (chan->tx_credits && !skb_queue_empty(&chan->tx_q)) {
2510 l2cap_do_send(chan, skb_dequeue(&chan->tx_q));
2511 chan->tx_credits--;
2512 sent++;
2513 }
2514
2515 BT_DBG("Sent %d credits %u queued %u", sent, chan->tx_credits,
2516 skb_queue_len(&chan->tx_q));
2517}
2518
2519int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len)
2520{
2521 struct sk_buff *skb;
2522 int err;
2523 struct sk_buff_head seg_queue;
2524
2525 if (!chan->conn)
2526 return -ENOTCONN;
2527
2528 /* Connectionless channel */
2529 if (chan->chan_type == L2CAP_CHAN_CONN_LESS) {
2530 skb = l2cap_create_connless_pdu(chan, msg, len);
2531 if (IS_ERR(skb))
2532 return PTR_ERR(skb);
2533
2534 l2cap_do_send(chan, skb);
2535 return len;
2536 }
2537
2538 switch (chan->mode) {
2539 case L2CAP_MODE_LE_FLOWCTL:
2540 case L2CAP_MODE_EXT_FLOWCTL:
2541 /* Check outgoing MTU */
2542 if (len > chan->omtu)
2543 return -EMSGSIZE;
2544
2545 __skb_queue_head_init(&seg_queue);
2546
2547 err = l2cap_segment_le_sdu(chan, &seg_queue, msg, len);
2548
2549 if (chan->state != BT_CONNECTED) {
2550 __skb_queue_purge(&seg_queue);
2551 err = -ENOTCONN;
2552 }
2553
2554 if (err)
2555 return err;
2556
2557 skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
2558
2559 l2cap_le_flowctl_send(chan);
2560
2561 if (!chan->tx_credits)
2562 chan->ops->suspend(chan);
2563
2564 err = len;
2565
2566 break;
2567
2568 case L2CAP_MODE_BASIC:
2569 /* Check outgoing MTU */
2570 if (len > chan->omtu)
2571 return -EMSGSIZE;
2572
2573 /* Create a basic PDU */
2574 skb = l2cap_create_basic_pdu(chan, msg, len);
2575 if (IS_ERR(skb))
2576 return PTR_ERR(skb);
2577
2578 l2cap_do_send(chan, skb);
2579 err = len;
2580 break;
2581
2582 case L2CAP_MODE_ERTM:
2583 case L2CAP_MODE_STREAMING:
2584 /* Check outgoing MTU */
2585 if (len > chan->omtu) {
2586 err = -EMSGSIZE;
2587 break;
2588 }
2589
2590 __skb_queue_head_init(&seg_queue);
2591
2592 /* Do segmentation before calling in to the state machine,
2593 * since it's possible to block while waiting for memory
2594 * allocation.
2595 */
2596 err = l2cap_segment_sdu(chan, &seg_queue, msg, len);
2597
2598 if (err)
2599 break;
2600
2601 if (chan->mode == L2CAP_MODE_ERTM)
2602 l2cap_tx(chan, NULL, &seg_queue, L2CAP_EV_DATA_REQUEST);
2603 else
2604 l2cap_streaming_send(chan, &seg_queue);
2605
2606 err = len;
2607
2608 /* If the skbs were not queued for sending, they'll still be in
2609 * seg_queue and need to be purged.
2610 */
2611 __skb_queue_purge(&seg_queue);
2612 break;
2613
2614 default:
2615 BT_DBG("bad state %1.1x", chan->mode);
2616 err = -EBADFD;
2617 }
2618
2619 return err;
2620}
2621EXPORT_SYMBOL_GPL(l2cap_chan_send);
2622
2623static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq)
2624{
2625 struct l2cap_ctrl control;
2626 u16 seq;
2627
2628 BT_DBG("chan %p, txseq %u", chan, txseq);
2629
2630 memset(&control, 0, sizeof(control));
2631 control.sframe = 1;
2632 control.super = L2CAP_SUPER_SREJ;
2633
2634 for (seq = chan->expected_tx_seq; seq != txseq;
2635 seq = __next_seq(chan, seq)) {
2636 if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) {
2637 control.reqseq = seq;
2638 l2cap_send_sframe(chan, &control);
2639 l2cap_seq_list_append(&chan->srej_list, seq);
2640 }
2641 }
2642
2643 chan->expected_tx_seq = __next_seq(chan, txseq);
2644}
2645
2646static void l2cap_send_srej_tail(struct l2cap_chan *chan)
2647{
2648 struct l2cap_ctrl control;
2649
2650 BT_DBG("chan %p", chan);
2651
2652 if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR)
2653 return;
2654
2655 memset(&control, 0, sizeof(control));
2656 control.sframe = 1;
2657 control.super = L2CAP_SUPER_SREJ;
2658 control.reqseq = chan->srej_list.tail;
2659 l2cap_send_sframe(chan, &control);
2660}
2661
2662static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq)
2663{
2664 struct l2cap_ctrl control;
2665 u16 initial_head;
2666 u16 seq;
2667
2668 BT_DBG("chan %p, txseq %u", chan, txseq);
2669
2670 memset(&control, 0, sizeof(control));
2671 control.sframe = 1;
2672 control.super = L2CAP_SUPER_SREJ;
2673
2674 /* Capture initial list head to allow only one pass through the list. */
2675 initial_head = chan->srej_list.head;
2676
2677 do {
2678 seq = l2cap_seq_list_pop(&chan->srej_list);
2679 if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR)
2680 break;
2681
2682 control.reqseq = seq;
2683 l2cap_send_sframe(chan, &control);
2684 l2cap_seq_list_append(&chan->srej_list, seq);
2685 } while (chan->srej_list.head != initial_head);
2686}
2687
2688static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq)
2689{
2690 struct sk_buff *acked_skb;
2691 u16 ackseq;
2692
2693 BT_DBG("chan %p, reqseq %u", chan, reqseq);
2694
2695 if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq)
2696 return;
2697
2698 BT_DBG("expected_ack_seq %u, unacked_frames %u",
2699 chan->expected_ack_seq, chan->unacked_frames);
2700
2701 for (ackseq = chan->expected_ack_seq; ackseq != reqseq;
2702 ackseq = __next_seq(chan, ackseq)) {
2703
2704 acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq);
2705 if (acked_skb) {
2706 skb_unlink(acked_skb, &chan->tx_q);
2707 kfree_skb(acked_skb);
2708 chan->unacked_frames--;
2709 }
2710 }
2711
2712 chan->expected_ack_seq = reqseq;
2713
2714 if (chan->unacked_frames == 0)
2715 __clear_retrans_timer(chan);
2716
2717 BT_DBG("unacked_frames %u", chan->unacked_frames);
2718}
2719
2720static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan)
2721{
2722 BT_DBG("chan %p", chan);
2723
2724 chan->expected_tx_seq = chan->buffer_seq;
2725 l2cap_seq_list_clear(&chan->srej_list);
2726 skb_queue_purge(&chan->srej_q);
2727 chan->rx_state = L2CAP_RX_STATE_RECV;
2728}
2729
2730static void l2cap_tx_state_xmit(struct l2cap_chan *chan,
2731 struct l2cap_ctrl *control,
2732 struct sk_buff_head *skbs, u8 event)
2733{
2734 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2735 event);
2736
2737 switch (event) {
2738 case L2CAP_EV_DATA_REQUEST:
2739 if (chan->tx_send_head == NULL)
2740 chan->tx_send_head = skb_peek(skbs);
2741
2742 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2743 l2cap_ertm_send(chan);
2744 break;
2745 case L2CAP_EV_LOCAL_BUSY_DETECTED:
2746 BT_DBG("Enter LOCAL_BUSY");
2747 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2748
2749 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2750 /* The SREJ_SENT state must be aborted if we are to
2751 * enter the LOCAL_BUSY state.
2752 */
2753 l2cap_abort_rx_srej_sent(chan);
2754 }
2755
2756 l2cap_send_ack(chan);
2757
2758 break;
2759 case L2CAP_EV_LOCAL_BUSY_CLEAR:
2760 BT_DBG("Exit LOCAL_BUSY");
2761 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2762
2763 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2764 struct l2cap_ctrl local_control;
2765
2766 memset(&local_control, 0, sizeof(local_control));
2767 local_control.sframe = 1;
2768 local_control.super = L2CAP_SUPER_RR;
2769 local_control.poll = 1;
2770 local_control.reqseq = chan->buffer_seq;
2771 l2cap_send_sframe(chan, &local_control);
2772
2773 chan->retry_count = 1;
2774 __set_monitor_timer(chan);
2775 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2776 }
2777 break;
2778 case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2779 l2cap_process_reqseq(chan, control->reqseq);
2780 break;
2781 case L2CAP_EV_EXPLICIT_POLL:
2782 l2cap_send_rr_or_rnr(chan, 1);
2783 chan->retry_count = 1;
2784 __set_monitor_timer(chan);
2785 __clear_ack_timer(chan);
2786 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2787 break;
2788 case L2CAP_EV_RETRANS_TO:
2789 l2cap_send_rr_or_rnr(chan, 1);
2790 chan->retry_count = 1;
2791 __set_monitor_timer(chan);
2792 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2793 break;
2794 case L2CAP_EV_RECV_FBIT:
2795 /* Nothing to process */
2796 break;
2797 default:
2798 break;
2799 }
2800}
2801
2802static void l2cap_tx_state_wait_f(struct l2cap_chan *chan,
2803 struct l2cap_ctrl *control,
2804 struct sk_buff_head *skbs, u8 event)
2805{
2806 BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
2807 event);
2808
2809 switch (event) {
2810 case L2CAP_EV_DATA_REQUEST:
2811 if (chan->tx_send_head == NULL)
2812 chan->tx_send_head = skb_peek(skbs);
2813 /* Queue data, but don't send. */
2814 skb_queue_splice_tail_init(skbs, &chan->tx_q);
2815 break;
2816 case L2CAP_EV_LOCAL_BUSY_DETECTED:
2817 BT_DBG("Enter LOCAL_BUSY");
2818 set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2819
2820 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
2821 /* The SREJ_SENT state must be aborted if we are to
2822 * enter the LOCAL_BUSY state.
2823 */
2824 l2cap_abort_rx_srej_sent(chan);
2825 }
2826
2827 l2cap_send_ack(chan);
2828
2829 break;
2830 case L2CAP_EV_LOCAL_BUSY_CLEAR:
2831 BT_DBG("Exit LOCAL_BUSY");
2832 clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
2833
2834 if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
2835 struct l2cap_ctrl local_control;
2836 memset(&local_control, 0, sizeof(local_control));
2837 local_control.sframe = 1;
2838 local_control.super = L2CAP_SUPER_RR;
2839 local_control.poll = 1;
2840 local_control.reqseq = chan->buffer_seq;
2841 l2cap_send_sframe(chan, &local_control);
2842
2843 chan->retry_count = 1;
2844 __set_monitor_timer(chan);
2845 chan->tx_state = L2CAP_TX_STATE_WAIT_F;
2846 }
2847 break;
2848 case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
2849 l2cap_process_reqseq(chan, control->reqseq);
2850 fallthrough;
2851
2852 case L2CAP_EV_RECV_FBIT:
2853 if (control && control->final) {
2854 __clear_monitor_timer(chan);
2855 if (chan->unacked_frames > 0)
2856 __set_retrans_timer(chan);
2857 chan->retry_count = 0;
2858 chan->tx_state = L2CAP_TX_STATE_XMIT;
2859 BT_DBG("recv fbit tx_state 0x2.2%x", chan->tx_state);
2860 }
2861 break;
2862 case L2CAP_EV_EXPLICIT_POLL:
2863 /* Ignore */
2864 break;
2865 case L2CAP_EV_MONITOR_TO:
2866 if (chan->max_tx == 0 || chan->retry_count < chan->max_tx) {
2867 l2cap_send_rr_or_rnr(chan, 1);
2868 __set_monitor_timer(chan);
2869 chan->retry_count++;
2870 } else {
2871 l2cap_send_disconn_req(chan, ECONNABORTED);
2872 }
2873 break;
2874 default:
2875 break;
2876 }
2877}
2878
2879static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
2880 struct sk_buff_head *skbs, u8 event)
2881{
2882 BT_DBG("chan %p, control %p, skbs %p, event %d, state %d",
2883 chan, control, skbs, event, chan->tx_state);
2884
2885 switch (chan->tx_state) {
2886 case L2CAP_TX_STATE_XMIT:
2887 l2cap_tx_state_xmit(chan, control, skbs, event);
2888 break;
2889 case L2CAP_TX_STATE_WAIT_F:
2890 l2cap_tx_state_wait_f(chan, control, skbs, event);
2891 break;
2892 default:
2893 /* Ignore event */
2894 break;
2895 }
2896}
2897
2898static void l2cap_pass_to_tx(struct l2cap_chan *chan,
2899 struct l2cap_ctrl *control)
2900{
2901 BT_DBG("chan %p, control %p", chan, control);
2902 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_REQSEQ_AND_FBIT);
2903}
2904
2905static void l2cap_pass_to_tx_fbit(struct l2cap_chan *chan,
2906 struct l2cap_ctrl *control)
2907{
2908 BT_DBG("chan %p, control %p", chan, control);
2909 l2cap_tx(chan, control, NULL, L2CAP_EV_RECV_FBIT);
2910}
2911
2912/* Copy frame to all raw sockets on that connection */
2913static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
2914{
2915 struct sk_buff *nskb;
2916 struct l2cap_chan *chan;
2917
2918 BT_DBG("conn %p", conn);
2919
2920 mutex_lock(&conn->chan_lock);
2921
2922 list_for_each_entry(chan, &conn->chan_l, list) {
2923 if (chan->chan_type != L2CAP_CHAN_RAW)
2924 continue;
2925
2926 /* Don't send frame to the channel it came from */
2927 if (bt_cb(skb)->l2cap.chan == chan)
2928 continue;
2929
2930 nskb = skb_clone(skb, GFP_KERNEL);
2931 if (!nskb)
2932 continue;
2933 if (chan->ops->recv(chan, nskb))
2934 kfree_skb(nskb);
2935 }
2936
2937 mutex_unlock(&conn->chan_lock);
2938}
2939
2940/* ---- L2CAP signalling commands ---- */
2941static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn, u8 code,
2942 u8 ident, u16 dlen, void *data)
2943{
2944 struct sk_buff *skb, **frag;
2945 struct l2cap_cmd_hdr *cmd;
2946 struct l2cap_hdr *lh;
2947 int len, count;
2948
2949 BT_DBG("conn %p, code 0x%2.2x, ident 0x%2.2x, len %u",
2950 conn, code, ident, dlen);
2951
2952 if (conn->mtu < L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE)
2953 return NULL;
2954
2955 len = L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE + dlen;
2956 count = min_t(unsigned int, conn->mtu, len);
2957
2958 skb = bt_skb_alloc(count, GFP_KERNEL);
2959 if (!skb)
2960 return NULL;
2961
2962 lh = skb_put(skb, L2CAP_HDR_SIZE);
2963 lh->len = cpu_to_le16(L2CAP_CMD_HDR_SIZE + dlen);
2964
2965 if (conn->hcon->type == LE_LINK)
2966 lh->cid = cpu_to_le16(L2CAP_CID_LE_SIGNALING);
2967 else
2968 lh->cid = cpu_to_le16(L2CAP_CID_SIGNALING);
2969
2970 cmd = skb_put(skb, L2CAP_CMD_HDR_SIZE);
2971 cmd->code = code;
2972 cmd->ident = ident;
2973 cmd->len = cpu_to_le16(dlen);
2974
2975 if (dlen) {
2976 count -= L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE;
2977 skb_put_data(skb, data, count);
2978 data += count;
2979 }
2980
2981 len -= skb->len;
2982
2983 /* Continuation fragments (no L2CAP header) */
2984 frag = &skb_shinfo(skb)->frag_list;
2985 while (len) {
2986 count = min_t(unsigned int, conn->mtu, len);
2987
2988 *frag = bt_skb_alloc(count, GFP_KERNEL);
2989 if (!*frag)
2990 goto fail;
2991
2992 skb_put_data(*frag, data, count);
2993
2994 len -= count;
2995 data += count;
2996
2997 frag = &(*frag)->next;
2998 }
2999
3000 return skb;
3001
3002fail:
3003 kfree_skb(skb);
3004 return NULL;
3005}
3006
3007static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen,
3008 unsigned long *val)
3009{
3010 struct l2cap_conf_opt *opt = *ptr;
3011 int len;
3012
3013 len = L2CAP_CONF_OPT_SIZE + opt->len;
3014 *ptr += len;
3015
3016 *type = opt->type;
3017 *olen = opt->len;
3018
3019 switch (opt->len) {
3020 case 1:
3021 *val = *((u8 *) opt->val);
3022 break;
3023
3024 case 2:
3025 *val = get_unaligned_le16(opt->val);
3026 break;
3027
3028 case 4:
3029 *val = get_unaligned_le32(opt->val);
3030 break;
3031
3032 default:
3033 *val = (unsigned long) opt->val;
3034 break;
3035 }
3036
3037 BT_DBG("type 0x%2.2x len %u val 0x%lx", *type, opt->len, *val);
3038 return len;
3039}
3040
3041static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val, size_t size)
3042{
3043 struct l2cap_conf_opt *opt = *ptr;
3044
3045 BT_DBG("type 0x%2.2x len %u val 0x%lx", type, len, val);
3046
3047 if (size < L2CAP_CONF_OPT_SIZE + len)
3048 return;
3049
3050 opt->type = type;
3051 opt->len = len;
3052
3053 switch (len) {
3054 case 1:
3055 *((u8 *) opt->val) = val;
3056 break;
3057
3058 case 2:
3059 put_unaligned_le16(val, opt->val);
3060 break;
3061
3062 case 4:
3063 put_unaligned_le32(val, opt->val);
3064 break;
3065
3066 default:
3067 memcpy(opt->val, (void *) val, len);
3068 break;
3069 }
3070
3071 *ptr += L2CAP_CONF_OPT_SIZE + len;
3072}
3073
3074static void l2cap_add_opt_efs(void **ptr, struct l2cap_chan *chan, size_t size)
3075{
3076 struct l2cap_conf_efs efs;
3077
3078 switch (chan->mode) {
3079 case L2CAP_MODE_ERTM:
3080 efs.id = chan->local_id;
3081 efs.stype = chan->local_stype;
3082 efs.msdu = cpu_to_le16(chan->local_msdu);
3083 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
3084 efs.acc_lat = cpu_to_le32(L2CAP_DEFAULT_ACC_LAT);
3085 efs.flush_to = cpu_to_le32(L2CAP_EFS_DEFAULT_FLUSH_TO);
3086 break;
3087
3088 case L2CAP_MODE_STREAMING:
3089 efs.id = 1;
3090 efs.stype = L2CAP_SERV_BESTEFFORT;
3091 efs.msdu = cpu_to_le16(chan->local_msdu);
3092 efs.sdu_itime = cpu_to_le32(chan->local_sdu_itime);
3093 efs.acc_lat = 0;
3094 efs.flush_to = 0;
3095 break;
3096
3097 default:
3098 return;
3099 }
3100
3101 l2cap_add_conf_opt(ptr, L2CAP_CONF_EFS, sizeof(efs),
3102 (unsigned long) &efs, size);
3103}
3104
3105static void l2cap_ack_timeout(struct work_struct *work)
3106{
3107 struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
3108 ack_timer.work);
3109 u16 frames_to_ack;
3110
3111 BT_DBG("chan %p", chan);
3112
3113 l2cap_chan_lock(chan);
3114
3115 frames_to_ack = __seq_offset(chan, chan->buffer_seq,
3116 chan->last_acked_seq);
3117
3118 if (frames_to_ack)
3119 l2cap_send_rr_or_rnr(chan, 0);
3120
3121 l2cap_chan_unlock(chan);
3122 l2cap_chan_put(chan);
3123}
3124
3125int l2cap_ertm_init(struct l2cap_chan *chan)
3126{
3127 int err;
3128
3129 chan->next_tx_seq = 0;
3130 chan->expected_tx_seq = 0;
3131 chan->expected_ack_seq = 0;
3132 chan->unacked_frames = 0;
3133 chan->buffer_seq = 0;
3134 chan->frames_sent = 0;
3135 chan->last_acked_seq = 0;
3136 chan->sdu = NULL;
3137 chan->sdu_last_frag = NULL;
3138 chan->sdu_len = 0;
3139
3140 skb_queue_head_init(&chan->tx_q);
3141
3142 if (chan->mode != L2CAP_MODE_ERTM)
3143 return 0;
3144
3145 chan->rx_state = L2CAP_RX_STATE_RECV;
3146 chan->tx_state = L2CAP_TX_STATE_XMIT;
3147
3148 skb_queue_head_init(&chan->srej_q);
3149
3150 err = l2cap_seq_list_init(&chan->srej_list, chan->tx_win);
3151 if (err < 0)
3152 return err;
3153
3154 err = l2cap_seq_list_init(&chan->retrans_list, chan->remote_tx_win);
3155 if (err < 0)
3156 l2cap_seq_list_free(&chan->srej_list);
3157
3158 return err;
3159}
3160
3161static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
3162{
3163 switch (mode) {
3164 case L2CAP_MODE_STREAMING:
3165 case L2CAP_MODE_ERTM:
3166 if (l2cap_mode_supported(mode, remote_feat_mask))
3167 return mode;
3168 fallthrough;
3169 default:
3170 return L2CAP_MODE_BASIC;
3171 }
3172}
3173
3174static inline bool __l2cap_ews_supported(struct l2cap_conn *conn)
3175{
3176 return (conn->feat_mask & L2CAP_FEAT_EXT_WINDOW);
3177}
3178
3179static inline bool __l2cap_efs_supported(struct l2cap_conn *conn)
3180{
3181 return (conn->feat_mask & L2CAP_FEAT_EXT_FLOW);
3182}
3183
3184static void __l2cap_set_ertm_timeouts(struct l2cap_chan *chan,
3185 struct l2cap_conf_rfc *rfc)
3186{
3187 rfc->retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO);
3188 rfc->monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO);
3189}
3190
3191static inline void l2cap_txwin_setup(struct l2cap_chan *chan)
3192{
3193 if (chan->tx_win > L2CAP_DEFAULT_TX_WINDOW &&
3194 __l2cap_ews_supported(chan->conn)) {
3195 /* use extended control field */
3196 set_bit(FLAG_EXT_CTRL, &chan->flags);
3197 chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW;
3198 } else {
3199 chan->tx_win = min_t(u16, chan->tx_win,
3200 L2CAP_DEFAULT_TX_WINDOW);
3201 chan->tx_win_max = L2CAP_DEFAULT_TX_WINDOW;
3202 }
3203 chan->ack_win = chan->tx_win;
3204}
3205
3206static void l2cap_mtu_auto(struct l2cap_chan *chan)
3207{
3208 struct hci_conn *conn = chan->conn->hcon;
3209
3210 chan->imtu = L2CAP_DEFAULT_MIN_MTU;
3211
3212 /* The 2-DH1 packet has between 2 and 56 information bytes
3213 * (including the 2-byte payload header)
3214 */
3215 if (!(conn->pkt_type & HCI_2DH1))
3216 chan->imtu = 54;
3217
3218 /* The 3-DH1 packet has between 2 and 85 information bytes
3219 * (including the 2-byte payload header)
3220 */
3221 if (!(conn->pkt_type & HCI_3DH1))
3222 chan->imtu = 83;
3223
3224 /* The 2-DH3 packet has between 2 and 369 information bytes
3225 * (including the 2-byte payload header)
3226 */
3227 if (!(conn->pkt_type & HCI_2DH3))
3228 chan->imtu = 367;
3229
3230 /* The 3-DH3 packet has between 2 and 554 information bytes
3231 * (including the 2-byte payload header)
3232 */
3233 if (!(conn->pkt_type & HCI_3DH3))
3234 chan->imtu = 552;
3235
3236 /* The 2-DH5 packet has between 2 and 681 information bytes
3237 * (including the 2-byte payload header)
3238 */
3239 if (!(conn->pkt_type & HCI_2DH5))
3240 chan->imtu = 679;
3241
3242 /* The 3-DH5 packet has between 2 and 1023 information bytes
3243 * (including the 2-byte payload header)
3244 */
3245 if (!(conn->pkt_type & HCI_3DH5))
3246 chan->imtu = 1021;
3247}
3248
3249static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
3250{
3251 struct l2cap_conf_req *req = data;
3252 struct l2cap_conf_rfc rfc = { .mode = chan->mode };
3253 void *ptr = req->data;
3254 void *endptr = data + data_size;
3255 u16 size;
3256
3257 BT_DBG("chan %p", chan);
3258
3259 if (chan->num_conf_req || chan->num_conf_rsp)
3260 goto done;
3261
3262 switch (chan->mode) {
3263 case L2CAP_MODE_STREAMING:
3264 case L2CAP_MODE_ERTM:
3265 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state))
3266 break;
3267
3268 if (__l2cap_efs_supported(chan->conn))
3269 set_bit(FLAG_EFS_ENABLE, &chan->flags);
3270
3271 fallthrough;
3272 default:
3273 chan->mode = l2cap_select_mode(rfc.mode, chan->conn->feat_mask);
3274 break;
3275 }
3276
3277done:
3278 if (chan->imtu != L2CAP_DEFAULT_MTU) {
3279 if (!chan->imtu)
3280 l2cap_mtu_auto(chan);
3281 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu,
3282 endptr - ptr);
3283 }
3284
3285 switch (chan->mode) {
3286 case L2CAP_MODE_BASIC:
3287 if (disable_ertm)
3288 break;
3289
3290 if (!(chan->conn->feat_mask & L2CAP_FEAT_ERTM) &&
3291 !(chan->conn->feat_mask & L2CAP_FEAT_STREAMING))
3292 break;
3293
3294 rfc.mode = L2CAP_MODE_BASIC;
3295 rfc.txwin_size = 0;
3296 rfc.max_transmit = 0;
3297 rfc.retrans_timeout = 0;
3298 rfc.monitor_timeout = 0;
3299 rfc.max_pdu_size = 0;
3300
3301 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3302 (unsigned long) &rfc, endptr - ptr);
3303 break;
3304
3305 case L2CAP_MODE_ERTM:
3306 rfc.mode = L2CAP_MODE_ERTM;
3307 rfc.max_transmit = chan->max_tx;
3308
3309 __l2cap_set_ertm_timeouts(chan, &rfc);
3310
3311 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3312 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3313 L2CAP_FCS_SIZE);
3314 rfc.max_pdu_size = cpu_to_le16(size);
3315
3316 l2cap_txwin_setup(chan);
3317
3318 rfc.txwin_size = min_t(u16, chan->tx_win,
3319 L2CAP_DEFAULT_TX_WINDOW);
3320
3321 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3322 (unsigned long) &rfc, endptr - ptr);
3323
3324 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3325 l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
3326
3327 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
3328 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3329 chan->tx_win, endptr - ptr);
3330
3331 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3332 if (chan->fcs == L2CAP_FCS_NONE ||
3333 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3334 chan->fcs = L2CAP_FCS_NONE;
3335 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3336 chan->fcs, endptr - ptr);
3337 }
3338 break;
3339
3340 case L2CAP_MODE_STREAMING:
3341 l2cap_txwin_setup(chan);
3342 rfc.mode = L2CAP_MODE_STREAMING;
3343 rfc.txwin_size = 0;
3344 rfc.max_transmit = 0;
3345 rfc.retrans_timeout = 0;
3346 rfc.monitor_timeout = 0;
3347
3348 size = min_t(u16, L2CAP_DEFAULT_MAX_PDU_SIZE, chan->conn->mtu -
3349 L2CAP_EXT_HDR_SIZE - L2CAP_SDULEN_SIZE -
3350 L2CAP_FCS_SIZE);
3351 rfc.max_pdu_size = cpu_to_le16(size);
3352
3353 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3354 (unsigned long) &rfc, endptr - ptr);
3355
3356 if (test_bit(FLAG_EFS_ENABLE, &chan->flags))
3357 l2cap_add_opt_efs(&ptr, chan, endptr - ptr);
3358
3359 if (chan->conn->feat_mask & L2CAP_FEAT_FCS)
3360 if (chan->fcs == L2CAP_FCS_NONE ||
3361 test_bit(CONF_RECV_NO_FCS, &chan->conf_state)) {
3362 chan->fcs = L2CAP_FCS_NONE;
3363 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1,
3364 chan->fcs, endptr - ptr);
3365 }
3366 break;
3367 }
3368
3369 req->dcid = cpu_to_le16(chan->dcid);
3370 req->flags = cpu_to_le16(0);
3371
3372 return ptr - data;
3373}
3374
3375static int l2cap_parse_conf_req(struct l2cap_chan *chan, void *data, size_t data_size)
3376{
3377 struct l2cap_conf_rsp *rsp = data;
3378 void *ptr = rsp->data;
3379 void *endptr = data + data_size;
3380 void *req = chan->conf_req;
3381 int len = chan->conf_len;
3382 int type, hint, olen;
3383 unsigned long val;
3384 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
3385 struct l2cap_conf_efs efs;
3386 u8 remote_efs = 0;
3387 u16 mtu = L2CAP_DEFAULT_MTU;
3388 u16 result = L2CAP_CONF_SUCCESS;
3389 u16 size;
3390
3391 BT_DBG("chan %p", chan);
3392
3393 while (len >= L2CAP_CONF_OPT_SIZE) {
3394 len -= l2cap_get_conf_opt(&req, &type, &olen, &val);
3395 if (len < 0)
3396 break;
3397
3398 hint = type & L2CAP_CONF_HINT;
3399 type &= L2CAP_CONF_MASK;
3400
3401 switch (type) {
3402 case L2CAP_CONF_MTU:
3403 if (olen != 2)
3404 break;
3405 mtu = val;
3406 break;
3407
3408 case L2CAP_CONF_FLUSH_TO:
3409 if (olen != 2)
3410 break;
3411 chan->flush_to = val;
3412 break;
3413
3414 case L2CAP_CONF_QOS:
3415 break;
3416
3417 case L2CAP_CONF_RFC:
3418 if (olen != sizeof(rfc))
3419 break;
3420 memcpy(&rfc, (void *) val, olen);
3421 break;
3422
3423 case L2CAP_CONF_FCS:
3424 if (olen != 1)
3425 break;
3426 if (val == L2CAP_FCS_NONE)
3427 set_bit(CONF_RECV_NO_FCS, &chan->conf_state);
3428 break;
3429
3430 case L2CAP_CONF_EFS:
3431 if (olen != sizeof(efs))
3432 break;
3433 remote_efs = 1;
3434 memcpy(&efs, (void *) val, olen);
3435 break;
3436
3437 case L2CAP_CONF_EWS:
3438 if (olen != 2)
3439 break;
3440 return -ECONNREFUSED;
3441
3442 default:
3443 if (hint)
3444 break;
3445 result = L2CAP_CONF_UNKNOWN;
3446 l2cap_add_conf_opt(&ptr, (u8)type, sizeof(u8), type, endptr - ptr);
3447 break;
3448 }
3449 }
3450
3451 if (chan->num_conf_rsp || chan->num_conf_req > 1)
3452 goto done;
3453
3454 switch (chan->mode) {
3455 case L2CAP_MODE_STREAMING:
3456 case L2CAP_MODE_ERTM:
3457 if (!test_bit(CONF_STATE2_DEVICE, &chan->conf_state)) {
3458 chan->mode = l2cap_select_mode(rfc.mode,
3459 chan->conn->feat_mask);
3460 break;
3461 }
3462
3463 if (remote_efs) {
3464 if (__l2cap_efs_supported(chan->conn))
3465 set_bit(FLAG_EFS_ENABLE, &chan->flags);
3466 else
3467 return -ECONNREFUSED;
3468 }
3469
3470 if (chan->mode != rfc.mode)
3471 return -ECONNREFUSED;
3472
3473 break;
3474 }
3475
3476done:
3477 if (chan->mode != rfc.mode) {
3478 result = L2CAP_CONF_UNACCEPT;
3479 rfc.mode = chan->mode;
3480
3481 if (chan->num_conf_rsp == 1)
3482 return -ECONNREFUSED;
3483
3484 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3485 (unsigned long) &rfc, endptr - ptr);
3486 }
3487
3488 if (result == L2CAP_CONF_SUCCESS) {
3489 /* Configure output options and let the other side know
3490 * which ones we don't like. */
3491
3492 if (mtu < L2CAP_DEFAULT_MIN_MTU)
3493 result = L2CAP_CONF_UNACCEPT;
3494 else {
3495 chan->omtu = mtu;
3496 set_bit(CONF_MTU_DONE, &chan->conf_state);
3497 }
3498 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->omtu, endptr - ptr);
3499
3500 if (remote_efs) {
3501 if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
3502 efs.stype != L2CAP_SERV_NOTRAFIC &&
3503 efs.stype != chan->local_stype) {
3504
3505 result = L2CAP_CONF_UNACCEPT;
3506
3507 if (chan->num_conf_req >= 1)
3508 return -ECONNREFUSED;
3509
3510 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
3511 sizeof(efs),
3512 (unsigned long) &efs, endptr - ptr);
3513 } else {
3514 /* Send PENDING Conf Rsp */
3515 result = L2CAP_CONF_PENDING;
3516 set_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
3517 }
3518 }
3519
3520 switch (rfc.mode) {
3521 case L2CAP_MODE_BASIC:
3522 chan->fcs = L2CAP_FCS_NONE;
3523 set_bit(CONF_MODE_DONE, &chan->conf_state);
3524 break;
3525
3526 case L2CAP_MODE_ERTM:
3527 if (!test_bit(CONF_EWS_RECV, &chan->conf_state))
3528 chan->remote_tx_win = rfc.txwin_size;
3529 else
3530 rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW;
3531
3532 chan->remote_max_tx = rfc.max_transmit;
3533
3534 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
3535 chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
3536 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
3537 rfc.max_pdu_size = cpu_to_le16(size);
3538 chan->remote_mps = size;
3539
3540 __l2cap_set_ertm_timeouts(chan, &rfc);
3541
3542 set_bit(CONF_MODE_DONE, &chan->conf_state);
3543
3544 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
3545 sizeof(rfc), (unsigned long) &rfc, endptr - ptr);
3546
3547 if (remote_efs &&
3548 test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
3549 chan->remote_id = efs.id;
3550 chan->remote_stype = efs.stype;
3551 chan->remote_msdu = le16_to_cpu(efs.msdu);
3552 chan->remote_flush_to =
3553 le32_to_cpu(efs.flush_to);
3554 chan->remote_acc_lat =
3555 le32_to_cpu(efs.acc_lat);
3556 chan->remote_sdu_itime =
3557 le32_to_cpu(efs.sdu_itime);
3558 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
3559 sizeof(efs),
3560 (unsigned long) &efs, endptr - ptr);
3561 }
3562 break;
3563
3564 case L2CAP_MODE_STREAMING:
3565 size = min_t(u16, le16_to_cpu(rfc.max_pdu_size),
3566 chan->conn->mtu - L2CAP_EXT_HDR_SIZE -
3567 L2CAP_SDULEN_SIZE - L2CAP_FCS_SIZE);
3568 rfc.max_pdu_size = cpu_to_le16(size);
3569 chan->remote_mps = size;
3570
3571 set_bit(CONF_MODE_DONE, &chan->conf_state);
3572
3573 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3574 (unsigned long) &rfc, endptr - ptr);
3575
3576 break;
3577
3578 default:
3579 result = L2CAP_CONF_UNACCEPT;
3580
3581 memset(&rfc, 0, sizeof(rfc));
3582 rfc.mode = chan->mode;
3583 }
3584
3585 if (result == L2CAP_CONF_SUCCESS)
3586 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
3587 }
3588 rsp->scid = cpu_to_le16(chan->dcid);
3589 rsp->result = cpu_to_le16(result);
3590 rsp->flags = cpu_to_le16(0);
3591
3592 return ptr - data;
3593}
3594
3595static int l2cap_parse_conf_rsp(struct l2cap_chan *chan, void *rsp, int len,
3596 void *data, size_t size, u16 *result)
3597{
3598 struct l2cap_conf_req *req = data;
3599 void *ptr = req->data;
3600 void *endptr = data + size;
3601 int type, olen;
3602 unsigned long val;
3603 struct l2cap_conf_rfc rfc = { .mode = L2CAP_MODE_BASIC };
3604 struct l2cap_conf_efs efs;
3605
3606 BT_DBG("chan %p, rsp %p, len %d, req %p", chan, rsp, len, data);
3607
3608 while (len >= L2CAP_CONF_OPT_SIZE) {
3609 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
3610 if (len < 0)
3611 break;
3612
3613 switch (type) {
3614 case L2CAP_CONF_MTU:
3615 if (olen != 2)
3616 break;
3617 if (val < L2CAP_DEFAULT_MIN_MTU) {
3618 *result = L2CAP_CONF_UNACCEPT;
3619 chan->imtu = L2CAP_DEFAULT_MIN_MTU;
3620 } else
3621 chan->imtu = val;
3622 l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu,
3623 endptr - ptr);
3624 break;
3625
3626 case L2CAP_CONF_FLUSH_TO:
3627 if (olen != 2)
3628 break;
3629 chan->flush_to = val;
3630 l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, 2,
3631 chan->flush_to, endptr - ptr);
3632 break;
3633
3634 case L2CAP_CONF_RFC:
3635 if (olen != sizeof(rfc))
3636 break;
3637 memcpy(&rfc, (void *)val, olen);
3638 if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state) &&
3639 rfc.mode != chan->mode)
3640 return -ECONNREFUSED;
3641 chan->fcs = 0;
3642 l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
3643 (unsigned long) &rfc, endptr - ptr);
3644 break;
3645
3646 case L2CAP_CONF_EWS:
3647 if (olen != 2)
3648 break;
3649 chan->ack_win = min_t(u16, val, chan->ack_win);
3650 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2,
3651 chan->tx_win, endptr - ptr);
3652 break;
3653
3654 case L2CAP_CONF_EFS:
3655 if (olen != sizeof(efs))
3656 break;
3657 memcpy(&efs, (void *)val, olen);
3658 if (chan->local_stype != L2CAP_SERV_NOTRAFIC &&
3659 efs.stype != L2CAP_SERV_NOTRAFIC &&
3660 efs.stype != chan->local_stype)
3661 return -ECONNREFUSED;
3662 l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs),
3663 (unsigned long) &efs, endptr - ptr);
3664 break;
3665
3666 case L2CAP_CONF_FCS:
3667 if (olen != 1)
3668 break;
3669 if (*result == L2CAP_CONF_PENDING)
3670 if (val == L2CAP_FCS_NONE)
3671 set_bit(CONF_RECV_NO_FCS,
3672 &chan->conf_state);
3673 break;
3674 }
3675 }
3676
3677 if (chan->mode == L2CAP_MODE_BASIC && chan->mode != rfc.mode)
3678 return -ECONNREFUSED;
3679
3680 chan->mode = rfc.mode;
3681
3682 if (*result == L2CAP_CONF_SUCCESS || *result == L2CAP_CONF_PENDING) {
3683 switch (rfc.mode) {
3684 case L2CAP_MODE_ERTM:
3685 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
3686 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
3687 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3688 if (!test_bit(FLAG_EXT_CTRL, &chan->flags))
3689 chan->ack_win = min_t(u16, chan->ack_win,
3690 rfc.txwin_size);
3691
3692 if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
3693 chan->local_msdu = le16_to_cpu(efs.msdu);
3694 chan->local_sdu_itime =
3695 le32_to_cpu(efs.sdu_itime);
3696 chan->local_acc_lat = le32_to_cpu(efs.acc_lat);
3697 chan->local_flush_to =
3698 le32_to_cpu(efs.flush_to);
3699 }
3700 break;
3701
3702 case L2CAP_MODE_STREAMING:
3703 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3704 }
3705 }
3706
3707 req->dcid = cpu_to_le16(chan->dcid);
3708 req->flags = cpu_to_le16(0);
3709
3710 return ptr - data;
3711}
3712
3713static int l2cap_build_conf_rsp(struct l2cap_chan *chan, void *data,
3714 u16 result, u16 flags)
3715{
3716 struct l2cap_conf_rsp *rsp = data;
3717 void *ptr = rsp->data;
3718
3719 BT_DBG("chan %p", chan);
3720
3721 rsp->scid = cpu_to_le16(chan->dcid);
3722 rsp->result = cpu_to_le16(result);
3723 rsp->flags = cpu_to_le16(flags);
3724
3725 return ptr - data;
3726}
3727
3728void __l2cap_le_connect_rsp_defer(struct l2cap_chan *chan)
3729{
3730 struct l2cap_le_conn_rsp rsp;
3731 struct l2cap_conn *conn = chan->conn;
3732
3733 BT_DBG("chan %p", chan);
3734
3735 rsp.dcid = cpu_to_le16(chan->scid);
3736 rsp.mtu = cpu_to_le16(chan->imtu);
3737 rsp.mps = cpu_to_le16(chan->mps);
3738 rsp.credits = cpu_to_le16(chan->rx_credits);
3739 rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS);
3740
3741 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CONN_RSP, sizeof(rsp),
3742 &rsp);
3743}
3744
3745static void l2cap_ecred_list_defer(struct l2cap_chan *chan, void *data)
3746{
3747 int *result = data;
3748
3749 if (*result || test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
3750 return;
3751
3752 switch (chan->state) {
3753 case BT_CONNECT2:
3754 /* If channel still pending accept add to result */
3755 (*result)++;
3756 return;
3757 case BT_CONNECTED:
3758 return;
3759 default:
3760 /* If not connected or pending accept it has been refused */
3761 *result = -ECONNREFUSED;
3762 return;
3763 }
3764}
3765
3766struct l2cap_ecred_rsp_data {
3767 struct {
3768 struct l2cap_ecred_conn_rsp_hdr rsp;
3769 __le16 scid[L2CAP_ECRED_MAX_CID];
3770 } __packed pdu;
3771 int count;
3772};
3773
3774static void l2cap_ecred_rsp_defer(struct l2cap_chan *chan, void *data)
3775{
3776 struct l2cap_ecred_rsp_data *rsp = data;
3777 struct l2cap_ecred_conn_rsp *rsp_flex =
3778 container_of(&rsp->pdu.rsp, struct l2cap_ecred_conn_rsp, hdr);
3779
3780 /* Check if channel for outgoing connection or if it wasn't deferred
3781 * since in those cases it must be skipped.
3782 */
3783 if (test_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags) ||
3784 !test_and_clear_bit(FLAG_DEFER_SETUP, &chan->flags))
3785 return;
3786
3787 /* Reset ident so only one response is sent */
3788 chan->ident = 0;
3789
3790 /* Include all channels pending with the same ident */
3791 if (!rsp->pdu.rsp.result)
3792 rsp_flex->dcid[rsp->count++] = cpu_to_le16(chan->scid);
3793 else
3794 l2cap_chan_del(chan, ECONNRESET);
3795}
3796
3797void __l2cap_ecred_conn_rsp_defer(struct l2cap_chan *chan)
3798{
3799 struct l2cap_conn *conn = chan->conn;
3800 struct l2cap_ecred_rsp_data data;
3801 u16 id = chan->ident;
3802 int result = 0;
3803
3804 if (!id)
3805 return;
3806
3807 BT_DBG("chan %p id %d", chan, id);
3808
3809 memset(&data, 0, sizeof(data));
3810
3811 data.pdu.rsp.mtu = cpu_to_le16(chan->imtu);
3812 data.pdu.rsp.mps = cpu_to_le16(chan->mps);
3813 data.pdu.rsp.credits = cpu_to_le16(chan->rx_credits);
3814 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_SUCCESS);
3815
3816 /* Verify that all channels are ready */
3817 __l2cap_chan_list_id(conn, id, l2cap_ecred_list_defer, &result);
3818
3819 if (result > 0)
3820 return;
3821
3822 if (result < 0)
3823 data.pdu.rsp.result = cpu_to_le16(L2CAP_CR_LE_AUTHORIZATION);
3824
3825 /* Build response */
3826 __l2cap_chan_list_id(conn, id, l2cap_ecred_rsp_defer, &data);
3827
3828 l2cap_send_cmd(conn, id, L2CAP_ECRED_CONN_RSP,
3829 sizeof(data.pdu.rsp) + (data.count * sizeof(__le16)),
3830 &data.pdu);
3831}
3832
3833void __l2cap_connect_rsp_defer(struct l2cap_chan *chan)
3834{
3835 struct l2cap_conn_rsp rsp;
3836 struct l2cap_conn *conn = chan->conn;
3837 u8 buf[128];
3838 u8 rsp_code;
3839
3840 rsp.scid = cpu_to_le16(chan->dcid);
3841 rsp.dcid = cpu_to_le16(chan->scid);
3842 rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
3843 rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
3844 rsp_code = L2CAP_CONN_RSP;
3845
3846 BT_DBG("chan %p rsp_code %u", chan, rsp_code);
3847
3848 l2cap_send_cmd(conn, chan->ident, rsp_code, sizeof(rsp), &rsp);
3849
3850 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
3851 return;
3852
3853 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
3854 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
3855 chan->num_conf_req++;
3856}
3857
3858static void l2cap_conf_rfc_get(struct l2cap_chan *chan, void *rsp, int len)
3859{
3860 int type, olen;
3861 unsigned long val;
3862 /* Use sane default values in case a misbehaving remote device
3863 * did not send an RFC or extended window size option.
3864 */
3865 u16 txwin_ext = chan->ack_win;
3866 struct l2cap_conf_rfc rfc = {
3867 .mode = chan->mode,
3868 .retrans_timeout = cpu_to_le16(L2CAP_DEFAULT_RETRANS_TO),
3869 .monitor_timeout = cpu_to_le16(L2CAP_DEFAULT_MONITOR_TO),
3870 .max_pdu_size = cpu_to_le16(chan->imtu),
3871 .txwin_size = min_t(u16, chan->ack_win, L2CAP_DEFAULT_TX_WINDOW),
3872 };
3873
3874 BT_DBG("chan %p, rsp %p, len %d", chan, rsp, len);
3875
3876 if ((chan->mode != L2CAP_MODE_ERTM) && (chan->mode != L2CAP_MODE_STREAMING))
3877 return;
3878
3879 while (len >= L2CAP_CONF_OPT_SIZE) {
3880 len -= l2cap_get_conf_opt(&rsp, &type, &olen, &val);
3881 if (len < 0)
3882 break;
3883
3884 switch (type) {
3885 case L2CAP_CONF_RFC:
3886 if (olen != sizeof(rfc))
3887 break;
3888 memcpy(&rfc, (void *)val, olen);
3889 break;
3890 case L2CAP_CONF_EWS:
3891 if (olen != 2)
3892 break;
3893 txwin_ext = val;
3894 break;
3895 }
3896 }
3897
3898 switch (rfc.mode) {
3899 case L2CAP_MODE_ERTM:
3900 chan->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
3901 chan->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
3902 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3903 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
3904 chan->ack_win = min_t(u16, chan->ack_win, txwin_ext);
3905 else
3906 chan->ack_win = min_t(u16, chan->ack_win,
3907 rfc.txwin_size);
3908 break;
3909 case L2CAP_MODE_STREAMING:
3910 chan->mps = le16_to_cpu(rfc.max_pdu_size);
3911 }
3912}
3913
3914static inline int l2cap_command_rej(struct l2cap_conn *conn,
3915 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
3916 u8 *data)
3917{
3918 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
3919
3920 if (cmd_len < sizeof(*rej))
3921 return -EPROTO;
3922
3923 if (rej->reason != L2CAP_REJ_NOT_UNDERSTOOD)
3924 return 0;
3925
3926 if ((conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_SENT) &&
3927 cmd->ident == conn->info_ident) {
3928 cancel_delayed_work(&conn->info_timer);
3929
3930 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
3931 conn->info_ident = 0;
3932
3933 l2cap_conn_start(conn);
3934 }
3935
3936 return 0;
3937}
3938
3939static void l2cap_connect(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd,
3940 u8 *data, u8 rsp_code)
3941{
3942 struct l2cap_conn_req *req = (struct l2cap_conn_req *) data;
3943 struct l2cap_conn_rsp rsp;
3944 struct l2cap_chan *chan = NULL, *pchan = NULL;
3945 int result, status = L2CAP_CS_NO_INFO;
3946
3947 u16 dcid = 0, scid = __le16_to_cpu(req->scid);
3948 __le16 psm = req->psm;
3949
3950 BT_DBG("psm 0x%2.2x scid 0x%4.4x", __le16_to_cpu(psm), scid);
3951
3952 /* Check if we have socket listening on psm */
3953 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
3954 &conn->hcon->dst, ACL_LINK);
3955 if (!pchan) {
3956 result = L2CAP_CR_BAD_PSM;
3957 goto response;
3958 }
3959
3960 mutex_lock(&conn->chan_lock);
3961 l2cap_chan_lock(pchan);
3962
3963 /* Check if the ACL is secure enough (if not SDP) */
3964 if (psm != cpu_to_le16(L2CAP_PSM_SDP) &&
3965 !hci_conn_check_link_mode(conn->hcon)) {
3966 conn->disc_reason = HCI_ERROR_AUTH_FAILURE;
3967 result = L2CAP_CR_SEC_BLOCK;
3968 goto response;
3969 }
3970
3971 result = L2CAP_CR_NO_MEM;
3972
3973 /* Check for valid dynamic CID range (as per Erratum 3253) */
3974 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) {
3975 result = L2CAP_CR_INVALID_SCID;
3976 goto response;
3977 }
3978
3979 /* Check if we already have channel with that dcid */
3980 if (__l2cap_get_chan_by_dcid(conn, scid)) {
3981 result = L2CAP_CR_SCID_IN_USE;
3982 goto response;
3983 }
3984
3985 chan = pchan->ops->new_connection(pchan);
3986 if (!chan)
3987 goto response;
3988
3989 /* For certain devices (ex: HID mouse), support for authentication,
3990 * pairing and bonding is optional. For such devices, inorder to avoid
3991 * the ACL alive for too long after L2CAP disconnection, reset the ACL
3992 * disc_timeout back to HCI_DISCONN_TIMEOUT during L2CAP connect.
3993 */
3994 conn->hcon->disc_timeout = HCI_DISCONN_TIMEOUT;
3995
3996 bacpy(&chan->src, &conn->hcon->src);
3997 bacpy(&chan->dst, &conn->hcon->dst);
3998 chan->src_type = bdaddr_src_type(conn->hcon);
3999 chan->dst_type = bdaddr_dst_type(conn->hcon);
4000 chan->psm = psm;
4001 chan->dcid = scid;
4002
4003 __l2cap_chan_add(conn, chan);
4004
4005 dcid = chan->scid;
4006
4007 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
4008
4009 chan->ident = cmd->ident;
4010
4011 if (conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE) {
4012 if (l2cap_chan_check_security(chan, false)) {
4013 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
4014 l2cap_state_change(chan, BT_CONNECT2);
4015 result = L2CAP_CR_PEND;
4016 status = L2CAP_CS_AUTHOR_PEND;
4017 chan->ops->defer(chan);
4018 } else {
4019 l2cap_state_change(chan, BT_CONFIG);
4020 result = L2CAP_CR_SUCCESS;
4021 status = L2CAP_CS_NO_INFO;
4022 }
4023 } else {
4024 l2cap_state_change(chan, BT_CONNECT2);
4025 result = L2CAP_CR_PEND;
4026 status = L2CAP_CS_AUTHEN_PEND;
4027 }
4028 } else {
4029 l2cap_state_change(chan, BT_CONNECT2);
4030 result = L2CAP_CR_PEND;
4031 status = L2CAP_CS_NO_INFO;
4032 }
4033
4034response:
4035 rsp.scid = cpu_to_le16(scid);
4036 rsp.dcid = cpu_to_le16(dcid);
4037 rsp.result = cpu_to_le16(result);
4038 rsp.status = cpu_to_le16(status);
4039 l2cap_send_cmd(conn, cmd->ident, rsp_code, sizeof(rsp), &rsp);
4040
4041 if (!pchan)
4042 return;
4043
4044 if (result == L2CAP_CR_PEND && status == L2CAP_CS_NO_INFO) {
4045 struct l2cap_info_req info;
4046 info.type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
4047
4048 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_SENT;
4049 conn->info_ident = l2cap_get_ident(conn);
4050
4051 schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
4052
4053 l2cap_send_cmd(conn, conn->info_ident, L2CAP_INFO_REQ,
4054 sizeof(info), &info);
4055 }
4056
4057 if (chan && !test_bit(CONF_REQ_SENT, &chan->conf_state) &&
4058 result == L2CAP_CR_SUCCESS) {
4059 u8 buf[128];
4060 set_bit(CONF_REQ_SENT, &chan->conf_state);
4061 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4062 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4063 chan->num_conf_req++;
4064 }
4065
4066 l2cap_chan_unlock(pchan);
4067 mutex_unlock(&conn->chan_lock);
4068 l2cap_chan_put(pchan);
4069}
4070
4071static int l2cap_connect_req(struct l2cap_conn *conn,
4072 struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
4073{
4074 if (cmd_len < sizeof(struct l2cap_conn_req))
4075 return -EPROTO;
4076
4077 l2cap_connect(conn, cmd, data, L2CAP_CONN_RSP);
4078 return 0;
4079}
4080
4081static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
4082 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4083 u8 *data)
4084{
4085 struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data;
4086 u16 scid, dcid, result, status;
4087 struct l2cap_chan *chan;
4088 u8 req[128];
4089 int err;
4090
4091 if (cmd_len < sizeof(*rsp))
4092 return -EPROTO;
4093
4094 scid = __le16_to_cpu(rsp->scid);
4095 dcid = __le16_to_cpu(rsp->dcid);
4096 result = __le16_to_cpu(rsp->result);
4097 status = __le16_to_cpu(rsp->status);
4098
4099 if (result == L2CAP_CR_SUCCESS && (dcid < L2CAP_CID_DYN_START ||
4100 dcid > L2CAP_CID_DYN_END))
4101 return -EPROTO;
4102
4103 BT_DBG("dcid 0x%4.4x scid 0x%4.4x result 0x%2.2x status 0x%2.2x",
4104 dcid, scid, result, status);
4105
4106 mutex_lock(&conn->chan_lock);
4107
4108 if (scid) {
4109 chan = __l2cap_get_chan_by_scid(conn, scid);
4110 if (!chan) {
4111 err = -EBADSLT;
4112 goto unlock;
4113 }
4114 } else {
4115 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
4116 if (!chan) {
4117 err = -EBADSLT;
4118 goto unlock;
4119 }
4120 }
4121
4122 chan = l2cap_chan_hold_unless_zero(chan);
4123 if (!chan) {
4124 err = -EBADSLT;
4125 goto unlock;
4126 }
4127
4128 err = 0;
4129
4130 l2cap_chan_lock(chan);
4131
4132 switch (result) {
4133 case L2CAP_CR_SUCCESS:
4134 if (__l2cap_get_chan_by_dcid(conn, dcid)) {
4135 err = -EBADSLT;
4136 break;
4137 }
4138
4139 l2cap_state_change(chan, BT_CONFIG);
4140 chan->ident = 0;
4141 chan->dcid = dcid;
4142 clear_bit(CONF_CONNECT_PEND, &chan->conf_state);
4143
4144 if (test_and_set_bit(CONF_REQ_SENT, &chan->conf_state))
4145 break;
4146
4147 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4148 l2cap_build_conf_req(chan, req, sizeof(req)), req);
4149 chan->num_conf_req++;
4150 break;
4151
4152 case L2CAP_CR_PEND:
4153 set_bit(CONF_CONNECT_PEND, &chan->conf_state);
4154 break;
4155
4156 default:
4157 l2cap_chan_del(chan, ECONNREFUSED);
4158 break;
4159 }
4160
4161 l2cap_chan_unlock(chan);
4162 l2cap_chan_put(chan);
4163
4164unlock:
4165 mutex_unlock(&conn->chan_lock);
4166
4167 return err;
4168}
4169
4170static inline void set_default_fcs(struct l2cap_chan *chan)
4171{
4172 /* FCS is enabled only in ERTM or streaming mode, if one or both
4173 * sides request it.
4174 */
4175 if (chan->mode != L2CAP_MODE_ERTM && chan->mode != L2CAP_MODE_STREAMING)
4176 chan->fcs = L2CAP_FCS_NONE;
4177 else if (!test_bit(CONF_RECV_NO_FCS, &chan->conf_state))
4178 chan->fcs = L2CAP_FCS_CRC16;
4179}
4180
4181static void l2cap_send_efs_conf_rsp(struct l2cap_chan *chan, void *data,
4182 u8 ident, u16 flags)
4183{
4184 struct l2cap_conn *conn = chan->conn;
4185
4186 BT_DBG("conn %p chan %p ident %d flags 0x%4.4x", conn, chan, ident,
4187 flags);
4188
4189 clear_bit(CONF_LOC_CONF_PEND, &chan->conf_state);
4190 set_bit(CONF_OUTPUT_DONE, &chan->conf_state);
4191
4192 l2cap_send_cmd(conn, ident, L2CAP_CONF_RSP,
4193 l2cap_build_conf_rsp(chan, data,
4194 L2CAP_CONF_SUCCESS, flags), data);
4195}
4196
4197static void cmd_reject_invalid_cid(struct l2cap_conn *conn, u8 ident,
4198 u16 scid, u16 dcid)
4199{
4200 struct l2cap_cmd_rej_cid rej;
4201
4202 rej.reason = cpu_to_le16(L2CAP_REJ_INVALID_CID);
4203 rej.scid = __cpu_to_le16(scid);
4204 rej.dcid = __cpu_to_le16(dcid);
4205
4206 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
4207}
4208
4209static inline int l2cap_config_req(struct l2cap_conn *conn,
4210 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4211 u8 *data)
4212{
4213 struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
4214 u16 dcid, flags;
4215 u8 rsp[64];
4216 struct l2cap_chan *chan;
4217 int len, err = 0;
4218
4219 if (cmd_len < sizeof(*req))
4220 return -EPROTO;
4221
4222 dcid = __le16_to_cpu(req->dcid);
4223 flags = __le16_to_cpu(req->flags);
4224
4225 BT_DBG("dcid 0x%4.4x flags 0x%2.2x", dcid, flags);
4226
4227 chan = l2cap_get_chan_by_scid(conn, dcid);
4228 if (!chan) {
4229 cmd_reject_invalid_cid(conn, cmd->ident, dcid, 0);
4230 return 0;
4231 }
4232
4233 if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2 &&
4234 chan->state != BT_CONNECTED) {
4235 cmd_reject_invalid_cid(conn, cmd->ident, chan->scid,
4236 chan->dcid);
4237 goto unlock;
4238 }
4239
4240 /* Reject if config buffer is too small. */
4241 len = cmd_len - sizeof(*req);
4242 if (chan->conf_len + len > sizeof(chan->conf_req)) {
4243 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4244 l2cap_build_conf_rsp(chan, rsp,
4245 L2CAP_CONF_REJECT, flags), rsp);
4246 goto unlock;
4247 }
4248
4249 /* Store config. */
4250 memcpy(chan->conf_req + chan->conf_len, req->data, len);
4251 chan->conf_len += len;
4252
4253 if (flags & L2CAP_CONF_FLAG_CONTINUATION) {
4254 /* Incomplete config. Send empty response. */
4255 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
4256 l2cap_build_conf_rsp(chan, rsp,
4257 L2CAP_CONF_SUCCESS, flags), rsp);
4258 goto unlock;
4259 }
4260
4261 /* Complete config. */
4262 len = l2cap_parse_conf_req(chan, rsp, sizeof(rsp));
4263 if (len < 0) {
4264 l2cap_send_disconn_req(chan, ECONNRESET);
4265 goto unlock;
4266 }
4267
4268 chan->ident = cmd->ident;
4269 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp);
4270 if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP)
4271 chan->num_conf_rsp++;
4272
4273 /* Reset config buffer. */
4274 chan->conf_len = 0;
4275
4276 if (!test_bit(CONF_OUTPUT_DONE, &chan->conf_state))
4277 goto unlock;
4278
4279 if (test_bit(CONF_INPUT_DONE, &chan->conf_state)) {
4280 set_default_fcs(chan);
4281
4282 if (chan->mode == L2CAP_MODE_ERTM ||
4283 chan->mode == L2CAP_MODE_STREAMING)
4284 err = l2cap_ertm_init(chan);
4285
4286 if (err < 0)
4287 l2cap_send_disconn_req(chan, -err);
4288 else
4289 l2cap_chan_ready(chan);
4290
4291 goto unlock;
4292 }
4293
4294 if (!test_and_set_bit(CONF_REQ_SENT, &chan->conf_state)) {
4295 u8 buf[64];
4296 l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
4297 l2cap_build_conf_req(chan, buf, sizeof(buf)), buf);
4298 chan->num_conf_req++;
4299 }
4300
4301 /* Got Conf Rsp PENDING from remote side and assume we sent
4302 Conf Rsp PENDING in the code above */
4303 if (test_bit(CONF_REM_CONF_PEND, &chan->conf_state) &&
4304 test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4305
4306 /* check compatibility */
4307
4308 /* Send rsp for BR/EDR channel */
4309 l2cap_send_efs_conf_rsp(chan, rsp, cmd->ident, flags);
4310 }
4311
4312unlock:
4313 l2cap_chan_unlock(chan);
4314 l2cap_chan_put(chan);
4315 return err;
4316}
4317
4318static inline int l2cap_config_rsp(struct l2cap_conn *conn,
4319 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4320 u8 *data)
4321{
4322 struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data;
4323 u16 scid, flags, result;
4324 struct l2cap_chan *chan;
4325 int len = cmd_len - sizeof(*rsp);
4326 int err = 0;
4327
4328 if (cmd_len < sizeof(*rsp))
4329 return -EPROTO;
4330
4331 scid = __le16_to_cpu(rsp->scid);
4332 flags = __le16_to_cpu(rsp->flags);
4333 result = __le16_to_cpu(rsp->result);
4334
4335 BT_DBG("scid 0x%4.4x flags 0x%2.2x result 0x%2.2x len %d", scid, flags,
4336 result, len);
4337
4338 chan = l2cap_get_chan_by_scid(conn, scid);
4339 if (!chan)
4340 return 0;
4341
4342 switch (result) {
4343 case L2CAP_CONF_SUCCESS:
4344 l2cap_conf_rfc_get(chan, rsp->data, len);
4345 clear_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4346 break;
4347
4348 case L2CAP_CONF_PENDING:
4349 set_bit(CONF_REM_CONF_PEND, &chan->conf_state);
4350
4351 if (test_bit(CONF_LOC_CONF_PEND, &chan->conf_state)) {
4352 char buf[64];
4353
4354 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4355 buf, sizeof(buf), &result);
4356 if (len < 0) {
4357 l2cap_send_disconn_req(chan, ECONNRESET);
4358 goto done;
4359 }
4360
4361 l2cap_send_efs_conf_rsp(chan, buf, cmd->ident, 0);
4362 }
4363 goto done;
4364
4365 case L2CAP_CONF_UNKNOWN:
4366 case L2CAP_CONF_UNACCEPT:
4367 if (chan->num_conf_rsp <= L2CAP_CONF_MAX_CONF_RSP) {
4368 char req[64];
4369
4370 if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) {
4371 l2cap_send_disconn_req(chan, ECONNRESET);
4372 goto done;
4373 }
4374
4375 /* throw out any old stored conf requests */
4376 result = L2CAP_CONF_SUCCESS;
4377 len = l2cap_parse_conf_rsp(chan, rsp->data, len,
4378 req, sizeof(req), &result);
4379 if (len < 0) {
4380 l2cap_send_disconn_req(chan, ECONNRESET);
4381 goto done;
4382 }
4383
4384 l2cap_send_cmd(conn, l2cap_get_ident(conn),
4385 L2CAP_CONF_REQ, len, req);
4386 chan->num_conf_req++;
4387 if (result != L2CAP_CONF_SUCCESS)
4388 goto done;
4389 break;
4390 }
4391 fallthrough;
4392
4393 default:
4394 l2cap_chan_set_err(chan, ECONNRESET);
4395
4396 __set_chan_timer(chan, L2CAP_DISC_REJ_TIMEOUT);
4397 l2cap_send_disconn_req(chan, ECONNRESET);
4398 goto done;
4399 }
4400
4401 if (flags & L2CAP_CONF_FLAG_CONTINUATION)
4402 goto done;
4403
4404 set_bit(CONF_INPUT_DONE, &chan->conf_state);
4405
4406 if (test_bit(CONF_OUTPUT_DONE, &chan->conf_state)) {
4407 set_default_fcs(chan);
4408
4409 if (chan->mode == L2CAP_MODE_ERTM ||
4410 chan->mode == L2CAP_MODE_STREAMING)
4411 err = l2cap_ertm_init(chan);
4412
4413 if (err < 0)
4414 l2cap_send_disconn_req(chan, -err);
4415 else
4416 l2cap_chan_ready(chan);
4417 }
4418
4419done:
4420 l2cap_chan_unlock(chan);
4421 l2cap_chan_put(chan);
4422 return err;
4423}
4424
4425static inline int l2cap_disconnect_req(struct l2cap_conn *conn,
4426 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4427 u8 *data)
4428{
4429 struct l2cap_disconn_req *req = (struct l2cap_disconn_req *) data;
4430 struct l2cap_disconn_rsp rsp;
4431 u16 dcid, scid;
4432 struct l2cap_chan *chan;
4433
4434 if (cmd_len != sizeof(*req))
4435 return -EPROTO;
4436
4437 scid = __le16_to_cpu(req->scid);
4438 dcid = __le16_to_cpu(req->dcid);
4439
4440 BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
4441
4442 chan = l2cap_get_chan_by_scid(conn, dcid);
4443 if (!chan) {
4444 cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid);
4445 return 0;
4446 }
4447
4448 rsp.dcid = cpu_to_le16(chan->scid);
4449 rsp.scid = cpu_to_le16(chan->dcid);
4450 l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
4451
4452 chan->ops->set_shutdown(chan);
4453
4454 l2cap_chan_unlock(chan);
4455 mutex_lock(&conn->chan_lock);
4456 l2cap_chan_lock(chan);
4457 l2cap_chan_del(chan, ECONNRESET);
4458 mutex_unlock(&conn->chan_lock);
4459
4460 chan->ops->close(chan);
4461
4462 l2cap_chan_unlock(chan);
4463 l2cap_chan_put(chan);
4464
4465 return 0;
4466}
4467
4468static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,
4469 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4470 u8 *data)
4471{
4472 struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data;
4473 u16 dcid, scid;
4474 struct l2cap_chan *chan;
4475
4476 if (cmd_len != sizeof(*rsp))
4477 return -EPROTO;
4478
4479 scid = __le16_to_cpu(rsp->scid);
4480 dcid = __le16_to_cpu(rsp->dcid);
4481
4482 BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
4483
4484 chan = l2cap_get_chan_by_scid(conn, scid);
4485 if (!chan) {
4486 return 0;
4487 }
4488
4489 if (chan->state != BT_DISCONN) {
4490 l2cap_chan_unlock(chan);
4491 l2cap_chan_put(chan);
4492 return 0;
4493 }
4494
4495 l2cap_chan_unlock(chan);
4496 mutex_lock(&conn->chan_lock);
4497 l2cap_chan_lock(chan);
4498 l2cap_chan_del(chan, 0);
4499 mutex_unlock(&conn->chan_lock);
4500
4501 chan->ops->close(chan);
4502
4503 l2cap_chan_unlock(chan);
4504 l2cap_chan_put(chan);
4505
4506 return 0;
4507}
4508
4509static inline int l2cap_information_req(struct l2cap_conn *conn,
4510 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4511 u8 *data)
4512{
4513 struct l2cap_info_req *req = (struct l2cap_info_req *) data;
4514 u16 type;
4515
4516 if (cmd_len != sizeof(*req))
4517 return -EPROTO;
4518
4519 type = __le16_to_cpu(req->type);
4520
4521 BT_DBG("type 0x%4.4x", type);
4522
4523 if (type == L2CAP_IT_FEAT_MASK) {
4524 u8 buf[8];
4525 u32 feat_mask = l2cap_feat_mask;
4526 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4527 rsp->type = cpu_to_le16(L2CAP_IT_FEAT_MASK);
4528 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4529 if (!disable_ertm)
4530 feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING
4531 | L2CAP_FEAT_FCS;
4532
4533 put_unaligned_le32(feat_mask, rsp->data);
4534 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4535 buf);
4536 } else if (type == L2CAP_IT_FIXED_CHAN) {
4537 u8 buf[12];
4538 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
4539
4540 rsp->type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4541 rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
4542 rsp->data[0] = conn->local_fixed_chan;
4543 memset(rsp->data + 1, 0, 7);
4544 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(buf),
4545 buf);
4546 } else {
4547 struct l2cap_info_rsp rsp;
4548 rsp.type = cpu_to_le16(type);
4549 rsp.result = cpu_to_le16(L2CAP_IR_NOTSUPP);
4550 l2cap_send_cmd(conn, cmd->ident, L2CAP_INFO_RSP, sizeof(rsp),
4551 &rsp);
4552 }
4553
4554 return 0;
4555}
4556
4557static inline int l2cap_information_rsp(struct l2cap_conn *conn,
4558 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4559 u8 *data)
4560{
4561 struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data;
4562 u16 type, result;
4563
4564 if (cmd_len < sizeof(*rsp))
4565 return -EPROTO;
4566
4567 type = __le16_to_cpu(rsp->type);
4568 result = __le16_to_cpu(rsp->result);
4569
4570 BT_DBG("type 0x%4.4x result 0x%2.2x", type, result);
4571
4572 /* L2CAP Info req/rsp are unbound to channels, add extra checks */
4573 if (cmd->ident != conn->info_ident ||
4574 conn->info_state & L2CAP_INFO_FEAT_MASK_REQ_DONE)
4575 return 0;
4576
4577 cancel_delayed_work(&conn->info_timer);
4578
4579 if (result != L2CAP_IR_SUCCESS) {
4580 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4581 conn->info_ident = 0;
4582
4583 l2cap_conn_start(conn);
4584
4585 return 0;
4586 }
4587
4588 switch (type) {
4589 case L2CAP_IT_FEAT_MASK:
4590 conn->feat_mask = get_unaligned_le32(rsp->data);
4591
4592 if (conn->feat_mask & L2CAP_FEAT_FIXED_CHAN) {
4593 struct l2cap_info_req req;
4594 req.type = cpu_to_le16(L2CAP_IT_FIXED_CHAN);
4595
4596 conn->info_ident = l2cap_get_ident(conn);
4597
4598 l2cap_send_cmd(conn, conn->info_ident,
4599 L2CAP_INFO_REQ, sizeof(req), &req);
4600 } else {
4601 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4602 conn->info_ident = 0;
4603
4604 l2cap_conn_start(conn);
4605 }
4606 break;
4607
4608 case L2CAP_IT_FIXED_CHAN:
4609 conn->remote_fixed_chan = rsp->data[0];
4610 conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
4611 conn->info_ident = 0;
4612
4613 l2cap_conn_start(conn);
4614 break;
4615 }
4616
4617 return 0;
4618}
4619
4620static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
4621 struct l2cap_cmd_hdr *cmd,
4622 u16 cmd_len, u8 *data)
4623{
4624 struct hci_conn *hcon = conn->hcon;
4625 struct l2cap_conn_param_update_req *req;
4626 struct l2cap_conn_param_update_rsp rsp;
4627 u16 min, max, latency, to_multiplier;
4628 int err;
4629
4630 if (hcon->role != HCI_ROLE_MASTER)
4631 return -EINVAL;
4632
4633 if (cmd_len != sizeof(struct l2cap_conn_param_update_req))
4634 return -EPROTO;
4635
4636 req = (struct l2cap_conn_param_update_req *) data;
4637 min = __le16_to_cpu(req->min);
4638 max = __le16_to_cpu(req->max);
4639 latency = __le16_to_cpu(req->latency);
4640 to_multiplier = __le16_to_cpu(req->to_multiplier);
4641
4642 BT_DBG("min 0x%4.4x max 0x%4.4x latency: 0x%4.4x Timeout: 0x%4.4x",
4643 min, max, latency, to_multiplier);
4644
4645 memset(&rsp, 0, sizeof(rsp));
4646
4647 err = hci_check_conn_params(min, max, latency, to_multiplier);
4648 if (err)
4649 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
4650 else
4651 rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_ACCEPTED);
4652
4653 l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP,
4654 sizeof(rsp), &rsp);
4655
4656 if (!err) {
4657 u8 store_hint;
4658
4659 store_hint = hci_le_conn_update(hcon, min, max, latency,
4660 to_multiplier);
4661 mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type,
4662 store_hint, min, max, latency,
4663 to_multiplier);
4664
4665 }
4666
4667 return 0;
4668}
4669
4670static int l2cap_le_connect_rsp(struct l2cap_conn *conn,
4671 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4672 u8 *data)
4673{
4674 struct l2cap_le_conn_rsp *rsp = (struct l2cap_le_conn_rsp *) data;
4675 struct hci_conn *hcon = conn->hcon;
4676 u16 dcid, mtu, mps, credits, result;
4677 struct l2cap_chan *chan;
4678 int err, sec_level;
4679
4680 if (cmd_len < sizeof(*rsp))
4681 return -EPROTO;
4682
4683 dcid = __le16_to_cpu(rsp->dcid);
4684 mtu = __le16_to_cpu(rsp->mtu);
4685 mps = __le16_to_cpu(rsp->mps);
4686 credits = __le16_to_cpu(rsp->credits);
4687 result = __le16_to_cpu(rsp->result);
4688
4689 if (result == L2CAP_CR_LE_SUCCESS && (mtu < 23 || mps < 23 ||
4690 dcid < L2CAP_CID_DYN_START ||
4691 dcid > L2CAP_CID_LE_DYN_END))
4692 return -EPROTO;
4693
4694 BT_DBG("dcid 0x%4.4x mtu %u mps %u credits %u result 0x%2.2x",
4695 dcid, mtu, mps, credits, result);
4696
4697 mutex_lock(&conn->chan_lock);
4698
4699 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
4700 if (!chan) {
4701 err = -EBADSLT;
4702 goto unlock;
4703 }
4704
4705 err = 0;
4706
4707 l2cap_chan_lock(chan);
4708
4709 switch (result) {
4710 case L2CAP_CR_LE_SUCCESS:
4711 if (__l2cap_get_chan_by_dcid(conn, dcid)) {
4712 err = -EBADSLT;
4713 break;
4714 }
4715
4716 chan->ident = 0;
4717 chan->dcid = dcid;
4718 chan->omtu = mtu;
4719 chan->remote_mps = mps;
4720 chan->tx_credits = credits;
4721 l2cap_chan_ready(chan);
4722 break;
4723
4724 case L2CAP_CR_LE_AUTHENTICATION:
4725 case L2CAP_CR_LE_ENCRYPTION:
4726 /* If we already have MITM protection we can't do
4727 * anything.
4728 */
4729 if (hcon->sec_level > BT_SECURITY_MEDIUM) {
4730 l2cap_chan_del(chan, ECONNREFUSED);
4731 break;
4732 }
4733
4734 sec_level = hcon->sec_level + 1;
4735 if (chan->sec_level < sec_level)
4736 chan->sec_level = sec_level;
4737
4738 /* We'll need to send a new Connect Request */
4739 clear_bit(FLAG_LE_CONN_REQ_SENT, &chan->flags);
4740
4741 smp_conn_security(hcon, chan->sec_level);
4742 break;
4743
4744 default:
4745 l2cap_chan_del(chan, ECONNREFUSED);
4746 break;
4747 }
4748
4749 l2cap_chan_unlock(chan);
4750
4751unlock:
4752 mutex_unlock(&conn->chan_lock);
4753
4754 return err;
4755}
4756
4757static inline int l2cap_bredr_sig_cmd(struct l2cap_conn *conn,
4758 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4759 u8 *data)
4760{
4761 int err = 0;
4762
4763 switch (cmd->code) {
4764 case L2CAP_COMMAND_REJ:
4765 l2cap_command_rej(conn, cmd, cmd_len, data);
4766 break;
4767
4768 case L2CAP_CONN_REQ:
4769 err = l2cap_connect_req(conn, cmd, cmd_len, data);
4770 break;
4771
4772 case L2CAP_CONN_RSP:
4773 l2cap_connect_create_rsp(conn, cmd, cmd_len, data);
4774 break;
4775
4776 case L2CAP_CONF_REQ:
4777 err = l2cap_config_req(conn, cmd, cmd_len, data);
4778 break;
4779
4780 case L2CAP_CONF_RSP:
4781 l2cap_config_rsp(conn, cmd, cmd_len, data);
4782 break;
4783
4784 case L2CAP_DISCONN_REQ:
4785 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
4786 break;
4787
4788 case L2CAP_DISCONN_RSP:
4789 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
4790 break;
4791
4792 case L2CAP_ECHO_REQ:
4793 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECHO_RSP, cmd_len, data);
4794 break;
4795
4796 case L2CAP_ECHO_RSP:
4797 break;
4798
4799 case L2CAP_INFO_REQ:
4800 err = l2cap_information_req(conn, cmd, cmd_len, data);
4801 break;
4802
4803 case L2CAP_INFO_RSP:
4804 l2cap_information_rsp(conn, cmd, cmd_len, data);
4805 break;
4806
4807 default:
4808 BT_ERR("Unknown BR/EDR signaling command 0x%2.2x", cmd->code);
4809 err = -EINVAL;
4810 break;
4811 }
4812
4813 return err;
4814}
4815
4816static int l2cap_le_connect_req(struct l2cap_conn *conn,
4817 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4818 u8 *data)
4819{
4820 struct l2cap_le_conn_req *req = (struct l2cap_le_conn_req *) data;
4821 struct l2cap_le_conn_rsp rsp;
4822 struct l2cap_chan *chan, *pchan;
4823 u16 dcid, scid, credits, mtu, mps;
4824 __le16 psm;
4825 u8 result;
4826
4827 if (cmd_len != sizeof(*req))
4828 return -EPROTO;
4829
4830 scid = __le16_to_cpu(req->scid);
4831 mtu = __le16_to_cpu(req->mtu);
4832 mps = __le16_to_cpu(req->mps);
4833 psm = req->psm;
4834 dcid = 0;
4835 credits = 0;
4836
4837 if (mtu < 23 || mps < 23)
4838 return -EPROTO;
4839
4840 BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
4841 scid, mtu, mps);
4842
4843 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
4844 * page 1059:
4845 *
4846 * Valid range: 0x0001-0x00ff
4847 *
4848 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
4849 */
4850 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
4851 result = L2CAP_CR_LE_BAD_PSM;
4852 chan = NULL;
4853 goto response;
4854 }
4855
4856 /* Check if we have socket listening on psm */
4857 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
4858 &conn->hcon->dst, LE_LINK);
4859 if (!pchan) {
4860 result = L2CAP_CR_LE_BAD_PSM;
4861 chan = NULL;
4862 goto response;
4863 }
4864
4865 mutex_lock(&conn->chan_lock);
4866 l2cap_chan_lock(pchan);
4867
4868 if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
4869 SMP_ALLOW_STK)) {
4870 result = L2CAP_CR_LE_AUTHENTICATION;
4871 chan = NULL;
4872 goto response_unlock;
4873 }
4874
4875 /* Check for valid dynamic CID range */
4876 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
4877 result = L2CAP_CR_LE_INVALID_SCID;
4878 chan = NULL;
4879 goto response_unlock;
4880 }
4881
4882 /* Check if we already have channel with that dcid */
4883 if (__l2cap_get_chan_by_dcid(conn, scid)) {
4884 result = L2CAP_CR_LE_SCID_IN_USE;
4885 chan = NULL;
4886 goto response_unlock;
4887 }
4888
4889 chan = pchan->ops->new_connection(pchan);
4890 if (!chan) {
4891 result = L2CAP_CR_LE_NO_MEM;
4892 goto response_unlock;
4893 }
4894
4895 bacpy(&chan->src, &conn->hcon->src);
4896 bacpy(&chan->dst, &conn->hcon->dst);
4897 chan->src_type = bdaddr_src_type(conn->hcon);
4898 chan->dst_type = bdaddr_dst_type(conn->hcon);
4899 chan->psm = psm;
4900 chan->dcid = scid;
4901 chan->omtu = mtu;
4902 chan->remote_mps = mps;
4903
4904 __l2cap_chan_add(conn, chan);
4905
4906 l2cap_le_flowctl_init(chan, __le16_to_cpu(req->credits));
4907
4908 dcid = chan->scid;
4909 credits = chan->rx_credits;
4910
4911 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
4912
4913 chan->ident = cmd->ident;
4914
4915 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
4916 l2cap_state_change(chan, BT_CONNECT2);
4917 /* The following result value is actually not defined
4918 * for LE CoC but we use it to let the function know
4919 * that it should bail out after doing its cleanup
4920 * instead of sending a response.
4921 */
4922 result = L2CAP_CR_PEND;
4923 chan->ops->defer(chan);
4924 } else {
4925 l2cap_chan_ready(chan);
4926 result = L2CAP_CR_LE_SUCCESS;
4927 }
4928
4929response_unlock:
4930 l2cap_chan_unlock(pchan);
4931 mutex_unlock(&conn->chan_lock);
4932 l2cap_chan_put(pchan);
4933
4934 if (result == L2CAP_CR_PEND)
4935 return 0;
4936
4937response:
4938 if (chan) {
4939 rsp.mtu = cpu_to_le16(chan->imtu);
4940 rsp.mps = cpu_to_le16(chan->mps);
4941 } else {
4942 rsp.mtu = 0;
4943 rsp.mps = 0;
4944 }
4945
4946 rsp.dcid = cpu_to_le16(dcid);
4947 rsp.credits = cpu_to_le16(credits);
4948 rsp.result = cpu_to_le16(result);
4949
4950 l2cap_send_cmd(conn, cmd->ident, L2CAP_LE_CONN_RSP, sizeof(rsp), &rsp);
4951
4952 return 0;
4953}
4954
4955static inline int l2cap_le_credits(struct l2cap_conn *conn,
4956 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
4957 u8 *data)
4958{
4959 struct l2cap_le_credits *pkt;
4960 struct l2cap_chan *chan;
4961 u16 cid, credits, max_credits;
4962
4963 if (cmd_len != sizeof(*pkt))
4964 return -EPROTO;
4965
4966 pkt = (struct l2cap_le_credits *) data;
4967 cid = __le16_to_cpu(pkt->cid);
4968 credits = __le16_to_cpu(pkt->credits);
4969
4970 BT_DBG("cid 0x%4.4x credits 0x%4.4x", cid, credits);
4971
4972 chan = l2cap_get_chan_by_dcid(conn, cid);
4973 if (!chan)
4974 return -EBADSLT;
4975
4976 max_credits = LE_FLOWCTL_MAX_CREDITS - chan->tx_credits;
4977 if (credits > max_credits) {
4978 BT_ERR("LE credits overflow");
4979 l2cap_send_disconn_req(chan, ECONNRESET);
4980
4981 /* Return 0 so that we don't trigger an unnecessary
4982 * command reject packet.
4983 */
4984 goto unlock;
4985 }
4986
4987 chan->tx_credits += credits;
4988
4989 /* Resume sending */
4990 l2cap_le_flowctl_send(chan);
4991
4992 if (chan->tx_credits)
4993 chan->ops->resume(chan);
4994
4995unlock:
4996 l2cap_chan_unlock(chan);
4997 l2cap_chan_put(chan);
4998
4999 return 0;
5000}
5001
5002static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
5003 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5004 u8 *data)
5005{
5006 struct l2cap_ecred_conn_req *req = (void *) data;
5007 DEFINE_RAW_FLEX(struct l2cap_ecred_conn_rsp, pdu, dcid, L2CAP_ECRED_MAX_CID);
5008 struct l2cap_chan *chan, *pchan;
5009 u16 mtu, mps;
5010 __le16 psm;
5011 u8 result, len = 0;
5012 int i, num_scid;
5013 bool defer = false;
5014
5015 if (!enable_ecred)
5016 return -EINVAL;
5017
5018 if (cmd_len < sizeof(*req) || (cmd_len - sizeof(*req)) % sizeof(u16)) {
5019 result = L2CAP_CR_LE_INVALID_PARAMS;
5020 goto response;
5021 }
5022
5023 cmd_len -= sizeof(*req);
5024 num_scid = cmd_len / sizeof(u16);
5025
5026 if (num_scid > L2CAP_ECRED_MAX_CID) {
5027 result = L2CAP_CR_LE_INVALID_PARAMS;
5028 goto response;
5029 }
5030
5031 mtu = __le16_to_cpu(req->mtu);
5032 mps = __le16_to_cpu(req->mps);
5033
5034 if (mtu < L2CAP_ECRED_MIN_MTU || mps < L2CAP_ECRED_MIN_MPS) {
5035 result = L2CAP_CR_LE_UNACCEPT_PARAMS;
5036 goto response;
5037 }
5038
5039 psm = req->psm;
5040
5041 /* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
5042 * page 1059:
5043 *
5044 * Valid range: 0x0001-0x00ff
5045 *
5046 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
5047 */
5048 if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
5049 result = L2CAP_CR_LE_BAD_PSM;
5050 goto response;
5051 }
5052
5053 BT_DBG("psm 0x%2.2x mtu %u mps %u", __le16_to_cpu(psm), mtu, mps);
5054
5055 memset(pdu, 0, sizeof(*pdu));
5056
5057 /* Check if we have socket listening on psm */
5058 pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
5059 &conn->hcon->dst, LE_LINK);
5060 if (!pchan) {
5061 result = L2CAP_CR_LE_BAD_PSM;
5062 goto response;
5063 }
5064
5065 mutex_lock(&conn->chan_lock);
5066 l2cap_chan_lock(pchan);
5067
5068 if (!smp_sufficient_security(conn->hcon, pchan->sec_level,
5069 SMP_ALLOW_STK)) {
5070 result = L2CAP_CR_LE_AUTHENTICATION;
5071 goto unlock;
5072 }
5073
5074 result = L2CAP_CR_LE_SUCCESS;
5075
5076 for (i = 0; i < num_scid; i++) {
5077 u16 scid = __le16_to_cpu(req->scid[i]);
5078
5079 BT_DBG("scid[%d] 0x%4.4x", i, scid);
5080
5081 pdu->dcid[i] = 0x0000;
5082 len += sizeof(*pdu->dcid);
5083
5084 /* Check for valid dynamic CID range */
5085 if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_LE_DYN_END) {
5086 result = L2CAP_CR_LE_INVALID_SCID;
5087 continue;
5088 }
5089
5090 /* Check if we already have channel with that dcid */
5091 if (__l2cap_get_chan_by_dcid(conn, scid)) {
5092 result = L2CAP_CR_LE_SCID_IN_USE;
5093 continue;
5094 }
5095
5096 chan = pchan->ops->new_connection(pchan);
5097 if (!chan) {
5098 result = L2CAP_CR_LE_NO_MEM;
5099 continue;
5100 }
5101
5102 bacpy(&chan->src, &conn->hcon->src);
5103 bacpy(&chan->dst, &conn->hcon->dst);
5104 chan->src_type = bdaddr_src_type(conn->hcon);
5105 chan->dst_type = bdaddr_dst_type(conn->hcon);
5106 chan->psm = psm;
5107 chan->dcid = scid;
5108 chan->omtu = mtu;
5109 chan->remote_mps = mps;
5110
5111 __l2cap_chan_add(conn, chan);
5112
5113 l2cap_ecred_init(chan, __le16_to_cpu(req->credits));
5114
5115 /* Init response */
5116 if (!pdu->credits) {
5117 pdu->mtu = cpu_to_le16(chan->imtu);
5118 pdu->mps = cpu_to_le16(chan->mps);
5119 pdu->credits = cpu_to_le16(chan->rx_credits);
5120 }
5121
5122 pdu->dcid[i] = cpu_to_le16(chan->scid);
5123
5124 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
5125
5126 chan->ident = cmd->ident;
5127 chan->mode = L2CAP_MODE_EXT_FLOWCTL;
5128
5129 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
5130 l2cap_state_change(chan, BT_CONNECT2);
5131 defer = true;
5132 chan->ops->defer(chan);
5133 } else {
5134 l2cap_chan_ready(chan);
5135 }
5136 }
5137
5138unlock:
5139 l2cap_chan_unlock(pchan);
5140 mutex_unlock(&conn->chan_lock);
5141 l2cap_chan_put(pchan);
5142
5143response:
5144 pdu->result = cpu_to_le16(result);
5145
5146 if (defer)
5147 return 0;
5148
5149 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_CONN_RSP,
5150 sizeof(*pdu) + len, pdu);
5151
5152 return 0;
5153}
5154
5155static inline int l2cap_ecred_conn_rsp(struct l2cap_conn *conn,
5156 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5157 u8 *data)
5158{
5159 struct l2cap_ecred_conn_rsp *rsp = (void *) data;
5160 struct hci_conn *hcon = conn->hcon;
5161 u16 mtu, mps, credits, result;
5162 struct l2cap_chan *chan, *tmp;
5163 int err = 0, sec_level;
5164 int i = 0;
5165
5166 if (cmd_len < sizeof(*rsp))
5167 return -EPROTO;
5168
5169 mtu = __le16_to_cpu(rsp->mtu);
5170 mps = __le16_to_cpu(rsp->mps);
5171 credits = __le16_to_cpu(rsp->credits);
5172 result = __le16_to_cpu(rsp->result);
5173
5174 BT_DBG("mtu %u mps %u credits %u result 0x%4.4x", mtu, mps, credits,
5175 result);
5176
5177 mutex_lock(&conn->chan_lock);
5178
5179 cmd_len -= sizeof(*rsp);
5180
5181 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
5182 u16 dcid;
5183
5184 if (chan->ident != cmd->ident ||
5185 chan->mode != L2CAP_MODE_EXT_FLOWCTL ||
5186 chan->state == BT_CONNECTED)
5187 continue;
5188
5189 l2cap_chan_lock(chan);
5190
5191 /* Check that there is a dcid for each pending channel */
5192 if (cmd_len < sizeof(dcid)) {
5193 l2cap_chan_del(chan, ECONNREFUSED);
5194 l2cap_chan_unlock(chan);
5195 continue;
5196 }
5197
5198 dcid = __le16_to_cpu(rsp->dcid[i++]);
5199 cmd_len -= sizeof(u16);
5200
5201 BT_DBG("dcid[%d] 0x%4.4x", i, dcid);
5202
5203 /* Check if dcid is already in use */
5204 if (dcid && __l2cap_get_chan_by_dcid(conn, dcid)) {
5205 /* If a device receives a
5206 * L2CAP_CREDIT_BASED_CONNECTION_RSP packet with an
5207 * already-assigned Destination CID, then both the
5208 * original channel and the new channel shall be
5209 * immediately discarded and not used.
5210 */
5211 l2cap_chan_del(chan, ECONNREFUSED);
5212 l2cap_chan_unlock(chan);
5213 chan = __l2cap_get_chan_by_dcid(conn, dcid);
5214 l2cap_chan_lock(chan);
5215 l2cap_chan_del(chan, ECONNRESET);
5216 l2cap_chan_unlock(chan);
5217 continue;
5218 }
5219
5220 switch (result) {
5221 case L2CAP_CR_LE_AUTHENTICATION:
5222 case L2CAP_CR_LE_ENCRYPTION:
5223 /* If we already have MITM protection we can't do
5224 * anything.
5225 */
5226 if (hcon->sec_level > BT_SECURITY_MEDIUM) {
5227 l2cap_chan_del(chan, ECONNREFUSED);
5228 break;
5229 }
5230
5231 sec_level = hcon->sec_level + 1;
5232 if (chan->sec_level < sec_level)
5233 chan->sec_level = sec_level;
5234
5235 /* We'll need to send a new Connect Request */
5236 clear_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags);
5237
5238 smp_conn_security(hcon, chan->sec_level);
5239 break;
5240
5241 case L2CAP_CR_LE_BAD_PSM:
5242 l2cap_chan_del(chan, ECONNREFUSED);
5243 break;
5244
5245 default:
5246 /* If dcid was not set it means channels was refused */
5247 if (!dcid) {
5248 l2cap_chan_del(chan, ECONNREFUSED);
5249 break;
5250 }
5251
5252 chan->ident = 0;
5253 chan->dcid = dcid;
5254 chan->omtu = mtu;
5255 chan->remote_mps = mps;
5256 chan->tx_credits = credits;
5257 l2cap_chan_ready(chan);
5258 break;
5259 }
5260
5261 l2cap_chan_unlock(chan);
5262 }
5263
5264 mutex_unlock(&conn->chan_lock);
5265
5266 return err;
5267}
5268
5269static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn,
5270 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5271 u8 *data)
5272{
5273 struct l2cap_ecred_reconf_req *req = (void *) data;
5274 struct l2cap_ecred_reconf_rsp rsp;
5275 u16 mtu, mps, result;
5276 struct l2cap_chan *chan;
5277 int i, num_scid;
5278
5279 if (!enable_ecred)
5280 return -EINVAL;
5281
5282 if (cmd_len < sizeof(*req) || cmd_len - sizeof(*req) % sizeof(u16)) {
5283 result = L2CAP_CR_LE_INVALID_PARAMS;
5284 goto respond;
5285 }
5286
5287 mtu = __le16_to_cpu(req->mtu);
5288 mps = __le16_to_cpu(req->mps);
5289
5290 BT_DBG("mtu %u mps %u", mtu, mps);
5291
5292 if (mtu < L2CAP_ECRED_MIN_MTU) {
5293 result = L2CAP_RECONF_INVALID_MTU;
5294 goto respond;
5295 }
5296
5297 if (mps < L2CAP_ECRED_MIN_MPS) {
5298 result = L2CAP_RECONF_INVALID_MPS;
5299 goto respond;
5300 }
5301
5302 cmd_len -= sizeof(*req);
5303 num_scid = cmd_len / sizeof(u16);
5304 result = L2CAP_RECONF_SUCCESS;
5305
5306 for (i = 0; i < num_scid; i++) {
5307 u16 scid;
5308
5309 scid = __le16_to_cpu(req->scid[i]);
5310 if (!scid)
5311 return -EPROTO;
5312
5313 chan = __l2cap_get_chan_by_dcid(conn, scid);
5314 if (!chan)
5315 continue;
5316
5317 /* If the MTU value is decreased for any of the included
5318 * channels, then the receiver shall disconnect all
5319 * included channels.
5320 */
5321 if (chan->omtu > mtu) {
5322 BT_ERR("chan %p decreased MTU %u -> %u", chan,
5323 chan->omtu, mtu);
5324 result = L2CAP_RECONF_INVALID_MTU;
5325 }
5326
5327 chan->omtu = mtu;
5328 chan->remote_mps = mps;
5329 }
5330
5331respond:
5332 rsp.result = cpu_to_le16(result);
5333
5334 l2cap_send_cmd(conn, cmd->ident, L2CAP_ECRED_RECONF_RSP, sizeof(rsp),
5335 &rsp);
5336
5337 return 0;
5338}
5339
5340static inline int l2cap_ecred_reconf_rsp(struct l2cap_conn *conn,
5341 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5342 u8 *data)
5343{
5344 struct l2cap_chan *chan, *tmp;
5345 struct l2cap_ecred_conn_rsp *rsp = (void *) data;
5346 u16 result;
5347
5348 if (cmd_len < sizeof(*rsp))
5349 return -EPROTO;
5350
5351 result = __le16_to_cpu(rsp->result);
5352
5353 BT_DBG("result 0x%4.4x", rsp->result);
5354
5355 if (!result)
5356 return 0;
5357
5358 list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
5359 if (chan->ident != cmd->ident)
5360 continue;
5361
5362 l2cap_chan_del(chan, ECONNRESET);
5363 }
5364
5365 return 0;
5366}
5367
5368static inline int l2cap_le_command_rej(struct l2cap_conn *conn,
5369 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5370 u8 *data)
5371{
5372 struct l2cap_cmd_rej_unk *rej = (struct l2cap_cmd_rej_unk *) data;
5373 struct l2cap_chan *chan;
5374
5375 if (cmd_len < sizeof(*rej))
5376 return -EPROTO;
5377
5378 mutex_lock(&conn->chan_lock);
5379
5380 chan = __l2cap_get_chan_by_ident(conn, cmd->ident);
5381 if (!chan)
5382 goto done;
5383
5384 chan = l2cap_chan_hold_unless_zero(chan);
5385 if (!chan)
5386 goto done;
5387
5388 l2cap_chan_lock(chan);
5389 l2cap_chan_del(chan, ECONNREFUSED);
5390 l2cap_chan_unlock(chan);
5391 l2cap_chan_put(chan);
5392
5393done:
5394 mutex_unlock(&conn->chan_lock);
5395 return 0;
5396}
5397
5398static inline int l2cap_le_sig_cmd(struct l2cap_conn *conn,
5399 struct l2cap_cmd_hdr *cmd, u16 cmd_len,
5400 u8 *data)
5401{
5402 int err = 0;
5403
5404 switch (cmd->code) {
5405 case L2CAP_COMMAND_REJ:
5406 l2cap_le_command_rej(conn, cmd, cmd_len, data);
5407 break;
5408
5409 case L2CAP_CONN_PARAM_UPDATE_REQ:
5410 err = l2cap_conn_param_update_req(conn, cmd, cmd_len, data);
5411 break;
5412
5413 case L2CAP_CONN_PARAM_UPDATE_RSP:
5414 break;
5415
5416 case L2CAP_LE_CONN_RSP:
5417 l2cap_le_connect_rsp(conn, cmd, cmd_len, data);
5418 break;
5419
5420 case L2CAP_LE_CONN_REQ:
5421 err = l2cap_le_connect_req(conn, cmd, cmd_len, data);
5422 break;
5423
5424 case L2CAP_LE_CREDITS:
5425 err = l2cap_le_credits(conn, cmd, cmd_len, data);
5426 break;
5427
5428 case L2CAP_ECRED_CONN_REQ:
5429 err = l2cap_ecred_conn_req(conn, cmd, cmd_len, data);
5430 break;
5431
5432 case L2CAP_ECRED_CONN_RSP:
5433 err = l2cap_ecred_conn_rsp(conn, cmd, cmd_len, data);
5434 break;
5435
5436 case L2CAP_ECRED_RECONF_REQ:
5437 err = l2cap_ecred_reconf_req(conn, cmd, cmd_len, data);
5438 break;
5439
5440 case L2CAP_ECRED_RECONF_RSP:
5441 err = l2cap_ecred_reconf_rsp(conn, cmd, cmd_len, data);
5442 break;
5443
5444 case L2CAP_DISCONN_REQ:
5445 err = l2cap_disconnect_req(conn, cmd, cmd_len, data);
5446 break;
5447
5448 case L2CAP_DISCONN_RSP:
5449 l2cap_disconnect_rsp(conn, cmd, cmd_len, data);
5450 break;
5451
5452 default:
5453 BT_ERR("Unknown LE signaling command 0x%2.2x", cmd->code);
5454 err = -EINVAL;
5455 break;
5456 }
5457
5458 return err;
5459}
5460
5461static inline void l2cap_le_sig_channel(struct l2cap_conn *conn,
5462 struct sk_buff *skb)
5463{
5464 struct hci_conn *hcon = conn->hcon;
5465 struct l2cap_cmd_hdr *cmd;
5466 u16 len;
5467 int err;
5468
5469 if (hcon->type != LE_LINK)
5470 goto drop;
5471
5472 if (skb->len < L2CAP_CMD_HDR_SIZE)
5473 goto drop;
5474
5475 cmd = (void *) skb->data;
5476 skb_pull(skb, L2CAP_CMD_HDR_SIZE);
5477
5478 len = le16_to_cpu(cmd->len);
5479
5480 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len, cmd->ident);
5481
5482 if (len != skb->len || !cmd->ident) {
5483 BT_DBG("corrupted command");
5484 goto drop;
5485 }
5486
5487 err = l2cap_le_sig_cmd(conn, cmd, len, skb->data);
5488 if (err) {
5489 struct l2cap_cmd_rej_unk rej;
5490
5491 BT_ERR("Wrong link type (%d)", err);
5492
5493 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
5494 l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ,
5495 sizeof(rej), &rej);
5496 }
5497
5498drop:
5499 kfree_skb(skb);
5500}
5501
5502static inline void l2cap_sig_send_rej(struct l2cap_conn *conn, u16 ident)
5503{
5504 struct l2cap_cmd_rej_unk rej;
5505
5506 rej.reason = cpu_to_le16(L2CAP_REJ_NOT_UNDERSTOOD);
5507 l2cap_send_cmd(conn, ident, L2CAP_COMMAND_REJ, sizeof(rej), &rej);
5508}
5509
5510static inline void l2cap_sig_channel(struct l2cap_conn *conn,
5511 struct sk_buff *skb)
5512{
5513 struct hci_conn *hcon = conn->hcon;
5514 struct l2cap_cmd_hdr *cmd;
5515 int err;
5516
5517 l2cap_raw_recv(conn, skb);
5518
5519 if (hcon->type != ACL_LINK)
5520 goto drop;
5521
5522 while (skb->len >= L2CAP_CMD_HDR_SIZE) {
5523 u16 len;
5524
5525 cmd = (void *) skb->data;
5526 skb_pull(skb, L2CAP_CMD_HDR_SIZE);
5527
5528 len = le16_to_cpu(cmd->len);
5529
5530 BT_DBG("code 0x%2.2x len %d id 0x%2.2x", cmd->code, len,
5531 cmd->ident);
5532
5533 if (len > skb->len || !cmd->ident) {
5534 BT_DBG("corrupted command");
5535 l2cap_sig_send_rej(conn, cmd->ident);
5536 skb_pull(skb, len > skb->len ? skb->len : len);
5537 continue;
5538 }
5539
5540 err = l2cap_bredr_sig_cmd(conn, cmd, len, skb->data);
5541 if (err) {
5542 BT_ERR("Wrong link type (%d)", err);
5543 l2cap_sig_send_rej(conn, cmd->ident);
5544 }
5545
5546 skb_pull(skb, len);
5547 }
5548
5549 if (skb->len > 0) {
5550 BT_DBG("corrupted command");
5551 l2cap_sig_send_rej(conn, 0);
5552 }
5553
5554drop:
5555 kfree_skb(skb);
5556}
5557
5558static int l2cap_check_fcs(struct l2cap_chan *chan, struct sk_buff *skb)
5559{
5560 u16 our_fcs, rcv_fcs;
5561 int hdr_size;
5562
5563 if (test_bit(FLAG_EXT_CTRL, &chan->flags))
5564 hdr_size = L2CAP_EXT_HDR_SIZE;
5565 else
5566 hdr_size = L2CAP_ENH_HDR_SIZE;
5567
5568 if (chan->fcs == L2CAP_FCS_CRC16) {
5569 skb_trim(skb, skb->len - L2CAP_FCS_SIZE);
5570 rcv_fcs = get_unaligned_le16(skb->data + skb->len);
5571 our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size);
5572
5573 if (our_fcs != rcv_fcs)
5574 return -EBADMSG;
5575 }
5576 return 0;
5577}
5578
5579static void l2cap_send_i_or_rr_or_rnr(struct l2cap_chan *chan)
5580{
5581 struct l2cap_ctrl control;
5582
5583 BT_DBG("chan %p", chan);
5584
5585 memset(&control, 0, sizeof(control));
5586 control.sframe = 1;
5587 control.final = 1;
5588 control.reqseq = chan->buffer_seq;
5589 set_bit(CONN_SEND_FBIT, &chan->conn_state);
5590
5591 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5592 control.super = L2CAP_SUPER_RNR;
5593 l2cap_send_sframe(chan, &control);
5594 }
5595
5596 if (test_and_clear_bit(CONN_REMOTE_BUSY, &chan->conn_state) &&
5597 chan->unacked_frames > 0)
5598 __set_retrans_timer(chan);
5599
5600 /* Send pending iframes */
5601 l2cap_ertm_send(chan);
5602
5603 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state) &&
5604 test_bit(CONN_SEND_FBIT, &chan->conn_state)) {
5605 /* F-bit wasn't sent in an s-frame or i-frame yet, so
5606 * send it now.
5607 */
5608 control.super = L2CAP_SUPER_RR;
5609 l2cap_send_sframe(chan, &control);
5610 }
5611}
5612
5613static void append_skb_frag(struct sk_buff *skb, struct sk_buff *new_frag,
5614 struct sk_buff **last_frag)
5615{
5616 /* skb->len reflects data in skb as well as all fragments
5617 * skb->data_len reflects only data in fragments
5618 */
5619 if (!skb_has_frag_list(skb))
5620 skb_shinfo(skb)->frag_list = new_frag;
5621
5622 new_frag->next = NULL;
5623
5624 (*last_frag)->next = new_frag;
5625 *last_frag = new_frag;
5626
5627 skb->len += new_frag->len;
5628 skb->data_len += new_frag->len;
5629 skb->truesize += new_frag->truesize;
5630}
5631
5632static int l2cap_reassemble_sdu(struct l2cap_chan *chan, struct sk_buff *skb,
5633 struct l2cap_ctrl *control)
5634{
5635 int err = -EINVAL;
5636
5637 switch (control->sar) {
5638 case L2CAP_SAR_UNSEGMENTED:
5639 if (chan->sdu)
5640 break;
5641
5642 err = chan->ops->recv(chan, skb);
5643 break;
5644
5645 case L2CAP_SAR_START:
5646 if (chan->sdu)
5647 break;
5648
5649 if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE))
5650 break;
5651
5652 chan->sdu_len = get_unaligned_le16(skb->data);
5653 skb_pull(skb, L2CAP_SDULEN_SIZE);
5654
5655 if (chan->sdu_len > chan->imtu) {
5656 err = -EMSGSIZE;
5657 break;
5658 }
5659
5660 if (skb->len >= chan->sdu_len)
5661 break;
5662
5663 chan->sdu = skb;
5664 chan->sdu_last_frag = skb;
5665
5666 skb = NULL;
5667 err = 0;
5668 break;
5669
5670 case L2CAP_SAR_CONTINUE:
5671 if (!chan->sdu)
5672 break;
5673
5674 append_skb_frag(chan->sdu, skb,
5675 &chan->sdu_last_frag);
5676 skb = NULL;
5677
5678 if (chan->sdu->len >= chan->sdu_len)
5679 break;
5680
5681 err = 0;
5682 break;
5683
5684 case L2CAP_SAR_END:
5685 if (!chan->sdu)
5686 break;
5687
5688 append_skb_frag(chan->sdu, skb,
5689 &chan->sdu_last_frag);
5690 skb = NULL;
5691
5692 if (chan->sdu->len != chan->sdu_len)
5693 break;
5694
5695 err = chan->ops->recv(chan, chan->sdu);
5696
5697 if (!err) {
5698 /* Reassembly complete */
5699 chan->sdu = NULL;
5700 chan->sdu_last_frag = NULL;
5701 chan->sdu_len = 0;
5702 }
5703 break;
5704 }
5705
5706 if (err) {
5707 kfree_skb(skb);
5708 kfree_skb(chan->sdu);
5709 chan->sdu = NULL;
5710 chan->sdu_last_frag = NULL;
5711 chan->sdu_len = 0;
5712 }
5713
5714 return err;
5715}
5716
5717static int l2cap_resegment(struct l2cap_chan *chan)
5718{
5719 /* Placeholder */
5720 return 0;
5721}
5722
5723void l2cap_chan_busy(struct l2cap_chan *chan, int busy)
5724{
5725 u8 event;
5726
5727 if (chan->mode != L2CAP_MODE_ERTM)
5728 return;
5729
5730 event = busy ? L2CAP_EV_LOCAL_BUSY_DETECTED : L2CAP_EV_LOCAL_BUSY_CLEAR;
5731 l2cap_tx(chan, NULL, NULL, event);
5732}
5733
5734static int l2cap_rx_queued_iframes(struct l2cap_chan *chan)
5735{
5736 int err = 0;
5737 /* Pass sequential frames to l2cap_reassemble_sdu()
5738 * until a gap is encountered.
5739 */
5740
5741 BT_DBG("chan %p", chan);
5742
5743 while (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5744 struct sk_buff *skb;
5745 BT_DBG("Searching for skb with txseq %d (queue len %d)",
5746 chan->buffer_seq, skb_queue_len(&chan->srej_q));
5747
5748 skb = l2cap_ertm_seq_in_queue(&chan->srej_q, chan->buffer_seq);
5749
5750 if (!skb)
5751 break;
5752
5753 skb_unlink(skb, &chan->srej_q);
5754 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
5755 err = l2cap_reassemble_sdu(chan, skb, &bt_cb(skb)->l2cap);
5756 if (err)
5757 break;
5758 }
5759
5760 if (skb_queue_empty(&chan->srej_q)) {
5761 chan->rx_state = L2CAP_RX_STATE_RECV;
5762 l2cap_send_ack(chan);
5763 }
5764
5765 return err;
5766}
5767
5768static void l2cap_handle_srej(struct l2cap_chan *chan,
5769 struct l2cap_ctrl *control)
5770{
5771 struct sk_buff *skb;
5772
5773 BT_DBG("chan %p, control %p", chan, control);
5774
5775 if (control->reqseq == chan->next_tx_seq) {
5776 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
5777 l2cap_send_disconn_req(chan, ECONNRESET);
5778 return;
5779 }
5780
5781 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
5782
5783 if (skb == NULL) {
5784 BT_DBG("Seq %d not available for retransmission",
5785 control->reqseq);
5786 return;
5787 }
5788
5789 if (chan->max_tx != 0 && bt_cb(skb)->l2cap.retries >= chan->max_tx) {
5790 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
5791 l2cap_send_disconn_req(chan, ECONNRESET);
5792 return;
5793 }
5794
5795 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
5796
5797 if (control->poll) {
5798 l2cap_pass_to_tx(chan, control);
5799
5800 set_bit(CONN_SEND_FBIT, &chan->conn_state);
5801 l2cap_retransmit(chan, control);
5802 l2cap_ertm_send(chan);
5803
5804 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
5805 set_bit(CONN_SREJ_ACT, &chan->conn_state);
5806 chan->srej_save_reqseq = control->reqseq;
5807 }
5808 } else {
5809 l2cap_pass_to_tx_fbit(chan, control);
5810
5811 if (control->final) {
5812 if (chan->srej_save_reqseq != control->reqseq ||
5813 !test_and_clear_bit(CONN_SREJ_ACT,
5814 &chan->conn_state))
5815 l2cap_retransmit(chan, control);
5816 } else {
5817 l2cap_retransmit(chan, control);
5818 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F) {
5819 set_bit(CONN_SREJ_ACT, &chan->conn_state);
5820 chan->srej_save_reqseq = control->reqseq;
5821 }
5822 }
5823 }
5824}
5825
5826static void l2cap_handle_rej(struct l2cap_chan *chan,
5827 struct l2cap_ctrl *control)
5828{
5829 struct sk_buff *skb;
5830
5831 BT_DBG("chan %p, control %p", chan, control);
5832
5833 if (control->reqseq == chan->next_tx_seq) {
5834 BT_DBG("Invalid reqseq %d, disconnecting", control->reqseq);
5835 l2cap_send_disconn_req(chan, ECONNRESET);
5836 return;
5837 }
5838
5839 skb = l2cap_ertm_seq_in_queue(&chan->tx_q, control->reqseq);
5840
5841 if (chan->max_tx && skb &&
5842 bt_cb(skb)->l2cap.retries >= chan->max_tx) {
5843 BT_DBG("Retry limit exceeded (%d)", chan->max_tx);
5844 l2cap_send_disconn_req(chan, ECONNRESET);
5845 return;
5846 }
5847
5848 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
5849
5850 l2cap_pass_to_tx(chan, control);
5851
5852 if (control->final) {
5853 if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state))
5854 l2cap_retransmit_all(chan, control);
5855 } else {
5856 l2cap_retransmit_all(chan, control);
5857 l2cap_ertm_send(chan);
5858 if (chan->tx_state == L2CAP_TX_STATE_WAIT_F)
5859 set_bit(CONN_REJ_ACT, &chan->conn_state);
5860 }
5861}
5862
5863static u8 l2cap_classify_txseq(struct l2cap_chan *chan, u16 txseq)
5864{
5865 BT_DBG("chan %p, txseq %d", chan, txseq);
5866
5867 BT_DBG("last_acked_seq %d, expected_tx_seq %d", chan->last_acked_seq,
5868 chan->expected_tx_seq);
5869
5870 if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
5871 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
5872 chan->tx_win) {
5873 /* See notes below regarding "double poll" and
5874 * invalid packets.
5875 */
5876 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
5877 BT_DBG("Invalid/Ignore - after SREJ");
5878 return L2CAP_TXSEQ_INVALID_IGNORE;
5879 } else {
5880 BT_DBG("Invalid - in window after SREJ sent");
5881 return L2CAP_TXSEQ_INVALID;
5882 }
5883 }
5884
5885 if (chan->srej_list.head == txseq) {
5886 BT_DBG("Expected SREJ");
5887 return L2CAP_TXSEQ_EXPECTED_SREJ;
5888 }
5889
5890 if (l2cap_ertm_seq_in_queue(&chan->srej_q, txseq)) {
5891 BT_DBG("Duplicate SREJ - txseq already stored");
5892 return L2CAP_TXSEQ_DUPLICATE_SREJ;
5893 }
5894
5895 if (l2cap_seq_list_contains(&chan->srej_list, txseq)) {
5896 BT_DBG("Unexpected SREJ - not requested");
5897 return L2CAP_TXSEQ_UNEXPECTED_SREJ;
5898 }
5899 }
5900
5901 if (chan->expected_tx_seq == txseq) {
5902 if (__seq_offset(chan, txseq, chan->last_acked_seq) >=
5903 chan->tx_win) {
5904 BT_DBG("Invalid - txseq outside tx window");
5905 return L2CAP_TXSEQ_INVALID;
5906 } else {
5907 BT_DBG("Expected");
5908 return L2CAP_TXSEQ_EXPECTED;
5909 }
5910 }
5911
5912 if (__seq_offset(chan, txseq, chan->last_acked_seq) <
5913 __seq_offset(chan, chan->expected_tx_seq, chan->last_acked_seq)) {
5914 BT_DBG("Duplicate - expected_tx_seq later than txseq");
5915 return L2CAP_TXSEQ_DUPLICATE;
5916 }
5917
5918 if (__seq_offset(chan, txseq, chan->last_acked_seq) >= chan->tx_win) {
5919 /* A source of invalid packets is a "double poll" condition,
5920 * where delays cause us to send multiple poll packets. If
5921 * the remote stack receives and processes both polls,
5922 * sequence numbers can wrap around in such a way that a
5923 * resent frame has a sequence number that looks like new data
5924 * with a sequence gap. This would trigger an erroneous SREJ
5925 * request.
5926 *
5927 * Fortunately, this is impossible with a tx window that's
5928 * less than half of the maximum sequence number, which allows
5929 * invalid frames to be safely ignored.
5930 *
5931 * With tx window sizes greater than half of the tx window
5932 * maximum, the frame is invalid and cannot be ignored. This
5933 * causes a disconnect.
5934 */
5935
5936 if (chan->tx_win <= ((chan->tx_win_max + 1) >> 1)) {
5937 BT_DBG("Invalid/Ignore - txseq outside tx window");
5938 return L2CAP_TXSEQ_INVALID_IGNORE;
5939 } else {
5940 BT_DBG("Invalid - txseq outside tx window");
5941 return L2CAP_TXSEQ_INVALID;
5942 }
5943 } else {
5944 BT_DBG("Unexpected - txseq indicates missing frames");
5945 return L2CAP_TXSEQ_UNEXPECTED;
5946 }
5947}
5948
5949static int l2cap_rx_state_recv(struct l2cap_chan *chan,
5950 struct l2cap_ctrl *control,
5951 struct sk_buff *skb, u8 event)
5952{
5953 struct l2cap_ctrl local_control;
5954 int err = 0;
5955 bool skb_in_use = false;
5956
5957 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
5958 event);
5959
5960 switch (event) {
5961 case L2CAP_EV_RECV_IFRAME:
5962 switch (l2cap_classify_txseq(chan, control->txseq)) {
5963 case L2CAP_TXSEQ_EXPECTED:
5964 l2cap_pass_to_tx(chan, control);
5965
5966 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
5967 BT_DBG("Busy, discarding expected seq %d",
5968 control->txseq);
5969 break;
5970 }
5971
5972 chan->expected_tx_seq = __next_seq(chan,
5973 control->txseq);
5974
5975 chan->buffer_seq = chan->expected_tx_seq;
5976 skb_in_use = true;
5977
5978 /* l2cap_reassemble_sdu may free skb, hence invalidate
5979 * control, so make a copy in advance to use it after
5980 * l2cap_reassemble_sdu returns and to avoid the race
5981 * condition, for example:
5982 *
5983 * The current thread calls:
5984 * l2cap_reassemble_sdu
5985 * chan->ops->recv == l2cap_sock_recv_cb
5986 * __sock_queue_rcv_skb
5987 * Another thread calls:
5988 * bt_sock_recvmsg
5989 * skb_recv_datagram
5990 * skb_free_datagram
5991 * Then the current thread tries to access control, but
5992 * it was freed by skb_free_datagram.
5993 */
5994 local_control = *control;
5995 err = l2cap_reassemble_sdu(chan, skb, control);
5996 if (err)
5997 break;
5998
5999 if (local_control.final) {
6000 if (!test_and_clear_bit(CONN_REJ_ACT,
6001 &chan->conn_state)) {
6002 local_control.final = 0;
6003 l2cap_retransmit_all(chan, &local_control);
6004 l2cap_ertm_send(chan);
6005 }
6006 }
6007
6008 if (!test_bit(CONN_LOCAL_BUSY, &chan->conn_state))
6009 l2cap_send_ack(chan);
6010 break;
6011 case L2CAP_TXSEQ_UNEXPECTED:
6012 l2cap_pass_to_tx(chan, control);
6013
6014 /* Can't issue SREJ frames in the local busy state.
6015 * Drop this frame, it will be seen as missing
6016 * when local busy is exited.
6017 */
6018 if (test_bit(CONN_LOCAL_BUSY, &chan->conn_state)) {
6019 BT_DBG("Busy, discarding unexpected seq %d",
6020 control->txseq);
6021 break;
6022 }
6023
6024 /* There was a gap in the sequence, so an SREJ
6025 * must be sent for each missing frame. The
6026 * current frame is stored for later use.
6027 */
6028 skb_queue_tail(&chan->srej_q, skb);
6029 skb_in_use = true;
6030 BT_DBG("Queued %p (queue len %d)", skb,
6031 skb_queue_len(&chan->srej_q));
6032
6033 clear_bit(CONN_SREJ_ACT, &chan->conn_state);
6034 l2cap_seq_list_clear(&chan->srej_list);
6035 l2cap_send_srej(chan, control->txseq);
6036
6037 chan->rx_state = L2CAP_RX_STATE_SREJ_SENT;
6038 break;
6039 case L2CAP_TXSEQ_DUPLICATE:
6040 l2cap_pass_to_tx(chan, control);
6041 break;
6042 case L2CAP_TXSEQ_INVALID_IGNORE:
6043 break;
6044 case L2CAP_TXSEQ_INVALID:
6045 default:
6046 l2cap_send_disconn_req(chan, ECONNRESET);
6047 break;
6048 }
6049 break;
6050 case L2CAP_EV_RECV_RR:
6051 l2cap_pass_to_tx(chan, control);
6052 if (control->final) {
6053 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6054
6055 if (!test_and_clear_bit(CONN_REJ_ACT,
6056 &chan->conn_state)) {
6057 control->final = 0;
6058 l2cap_retransmit_all(chan, control);
6059 }
6060
6061 l2cap_ertm_send(chan);
6062 } else if (control->poll) {
6063 l2cap_send_i_or_rr_or_rnr(chan);
6064 } else {
6065 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6066 &chan->conn_state) &&
6067 chan->unacked_frames)
6068 __set_retrans_timer(chan);
6069
6070 l2cap_ertm_send(chan);
6071 }
6072 break;
6073 case L2CAP_EV_RECV_RNR:
6074 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6075 l2cap_pass_to_tx(chan, control);
6076 if (control && control->poll) {
6077 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6078 l2cap_send_rr_or_rnr(chan, 0);
6079 }
6080 __clear_retrans_timer(chan);
6081 l2cap_seq_list_clear(&chan->retrans_list);
6082 break;
6083 case L2CAP_EV_RECV_REJ:
6084 l2cap_handle_rej(chan, control);
6085 break;
6086 case L2CAP_EV_RECV_SREJ:
6087 l2cap_handle_srej(chan, control);
6088 break;
6089 default:
6090 break;
6091 }
6092
6093 if (skb && !skb_in_use) {
6094 BT_DBG("Freeing %p", skb);
6095 kfree_skb(skb);
6096 }
6097
6098 return err;
6099}
6100
6101static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan,
6102 struct l2cap_ctrl *control,
6103 struct sk_buff *skb, u8 event)
6104{
6105 int err = 0;
6106 u16 txseq = control->txseq;
6107 bool skb_in_use = false;
6108
6109 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6110 event);
6111
6112 switch (event) {
6113 case L2CAP_EV_RECV_IFRAME:
6114 switch (l2cap_classify_txseq(chan, txseq)) {
6115 case L2CAP_TXSEQ_EXPECTED:
6116 /* Keep frame for reassembly later */
6117 l2cap_pass_to_tx(chan, control);
6118 skb_queue_tail(&chan->srej_q, skb);
6119 skb_in_use = true;
6120 BT_DBG("Queued %p (queue len %d)", skb,
6121 skb_queue_len(&chan->srej_q));
6122
6123 chan->expected_tx_seq = __next_seq(chan, txseq);
6124 break;
6125 case L2CAP_TXSEQ_EXPECTED_SREJ:
6126 l2cap_seq_list_pop(&chan->srej_list);
6127
6128 l2cap_pass_to_tx(chan, control);
6129 skb_queue_tail(&chan->srej_q, skb);
6130 skb_in_use = true;
6131 BT_DBG("Queued %p (queue len %d)", skb,
6132 skb_queue_len(&chan->srej_q));
6133
6134 err = l2cap_rx_queued_iframes(chan);
6135 if (err)
6136 break;
6137
6138 break;
6139 case L2CAP_TXSEQ_UNEXPECTED:
6140 /* Got a frame that can't be reassembled yet.
6141 * Save it for later, and send SREJs to cover
6142 * the missing frames.
6143 */
6144 skb_queue_tail(&chan->srej_q, skb);
6145 skb_in_use = true;
6146 BT_DBG("Queued %p (queue len %d)", skb,
6147 skb_queue_len(&chan->srej_q));
6148
6149 l2cap_pass_to_tx(chan, control);
6150 l2cap_send_srej(chan, control->txseq);
6151 break;
6152 case L2CAP_TXSEQ_UNEXPECTED_SREJ:
6153 /* This frame was requested with an SREJ, but
6154 * some expected retransmitted frames are
6155 * missing. Request retransmission of missing
6156 * SREJ'd frames.
6157 */
6158 skb_queue_tail(&chan->srej_q, skb);
6159 skb_in_use = true;
6160 BT_DBG("Queued %p (queue len %d)", skb,
6161 skb_queue_len(&chan->srej_q));
6162
6163 l2cap_pass_to_tx(chan, control);
6164 l2cap_send_srej_list(chan, control->txseq);
6165 break;
6166 case L2CAP_TXSEQ_DUPLICATE_SREJ:
6167 /* We've already queued this frame. Drop this copy. */
6168 l2cap_pass_to_tx(chan, control);
6169 break;
6170 case L2CAP_TXSEQ_DUPLICATE:
6171 /* Expecting a later sequence number, so this frame
6172 * was already received. Ignore it completely.
6173 */
6174 break;
6175 case L2CAP_TXSEQ_INVALID_IGNORE:
6176 break;
6177 case L2CAP_TXSEQ_INVALID:
6178 default:
6179 l2cap_send_disconn_req(chan, ECONNRESET);
6180 break;
6181 }
6182 break;
6183 case L2CAP_EV_RECV_RR:
6184 l2cap_pass_to_tx(chan, control);
6185 if (control->final) {
6186 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6187
6188 if (!test_and_clear_bit(CONN_REJ_ACT,
6189 &chan->conn_state)) {
6190 control->final = 0;
6191 l2cap_retransmit_all(chan, control);
6192 }
6193
6194 l2cap_ertm_send(chan);
6195 } else if (control->poll) {
6196 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6197 &chan->conn_state) &&
6198 chan->unacked_frames) {
6199 __set_retrans_timer(chan);
6200 }
6201
6202 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6203 l2cap_send_srej_tail(chan);
6204 } else {
6205 if (test_and_clear_bit(CONN_REMOTE_BUSY,
6206 &chan->conn_state) &&
6207 chan->unacked_frames)
6208 __set_retrans_timer(chan);
6209
6210 l2cap_send_ack(chan);
6211 }
6212 break;
6213 case L2CAP_EV_RECV_RNR:
6214 set_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6215 l2cap_pass_to_tx(chan, control);
6216 if (control->poll) {
6217 l2cap_send_srej_tail(chan);
6218 } else {
6219 struct l2cap_ctrl rr_control;
6220 memset(&rr_control, 0, sizeof(rr_control));
6221 rr_control.sframe = 1;
6222 rr_control.super = L2CAP_SUPER_RR;
6223 rr_control.reqseq = chan->buffer_seq;
6224 l2cap_send_sframe(chan, &rr_control);
6225 }
6226
6227 break;
6228 case L2CAP_EV_RECV_REJ:
6229 l2cap_handle_rej(chan, control);
6230 break;
6231 case L2CAP_EV_RECV_SREJ:
6232 l2cap_handle_srej(chan, control);
6233 break;
6234 }
6235
6236 if (skb && !skb_in_use) {
6237 BT_DBG("Freeing %p", skb);
6238 kfree_skb(skb);
6239 }
6240
6241 return err;
6242}
6243
6244static int l2cap_finish_move(struct l2cap_chan *chan)
6245{
6246 BT_DBG("chan %p", chan);
6247
6248 chan->rx_state = L2CAP_RX_STATE_RECV;
6249 chan->conn->mtu = chan->conn->hcon->mtu;
6250
6251 return l2cap_resegment(chan);
6252}
6253
6254static int l2cap_rx_state_wait_p(struct l2cap_chan *chan,
6255 struct l2cap_ctrl *control,
6256 struct sk_buff *skb, u8 event)
6257{
6258 int err;
6259
6260 BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
6261 event);
6262
6263 if (!control->poll)
6264 return -EPROTO;
6265
6266 l2cap_process_reqseq(chan, control->reqseq);
6267
6268 if (!skb_queue_empty(&chan->tx_q))
6269 chan->tx_send_head = skb_peek(&chan->tx_q);
6270 else
6271 chan->tx_send_head = NULL;
6272
6273 /* Rewind next_tx_seq to the point expected
6274 * by the receiver.
6275 */
6276 chan->next_tx_seq = control->reqseq;
6277 chan->unacked_frames = 0;
6278
6279 err = l2cap_finish_move(chan);
6280 if (err)
6281 return err;
6282
6283 set_bit(CONN_SEND_FBIT, &chan->conn_state);
6284 l2cap_send_i_or_rr_or_rnr(chan);
6285
6286 if (event == L2CAP_EV_RECV_IFRAME)
6287 return -EPROTO;
6288
6289 return l2cap_rx_state_recv(chan, control, NULL, event);
6290}
6291
6292static int l2cap_rx_state_wait_f(struct l2cap_chan *chan,
6293 struct l2cap_ctrl *control,
6294 struct sk_buff *skb, u8 event)
6295{
6296 int err;
6297
6298 if (!control->final)
6299 return -EPROTO;
6300
6301 clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
6302
6303 chan->rx_state = L2CAP_RX_STATE_RECV;
6304 l2cap_process_reqseq(chan, control->reqseq);
6305
6306 if (!skb_queue_empty(&chan->tx_q))
6307 chan->tx_send_head = skb_peek(&chan->tx_q);
6308 else
6309 chan->tx_send_head = NULL;
6310
6311 /* Rewind next_tx_seq to the point expected
6312 * by the receiver.
6313 */
6314 chan->next_tx_seq = control->reqseq;
6315 chan->unacked_frames = 0;
6316 chan->conn->mtu = chan->conn->hcon->mtu;
6317
6318 err = l2cap_resegment(chan);
6319
6320 if (!err)
6321 err = l2cap_rx_state_recv(chan, control, skb, event);
6322
6323 return err;
6324}
6325
6326static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq)
6327{
6328 /* Make sure reqseq is for a packet that has been sent but not acked */
6329 u16 unacked;
6330
6331 unacked = __seq_offset(chan, chan->next_tx_seq, chan->expected_ack_seq);
6332 return __seq_offset(chan, chan->next_tx_seq, reqseq) <= unacked;
6333}
6334
6335static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
6336 struct sk_buff *skb, u8 event)
6337{
6338 int err = 0;
6339
6340 BT_DBG("chan %p, control %p, skb %p, event %d, state %d", chan,
6341 control, skb, event, chan->rx_state);
6342
6343 if (__valid_reqseq(chan, control->reqseq)) {
6344 switch (chan->rx_state) {
6345 case L2CAP_RX_STATE_RECV:
6346 err = l2cap_rx_state_recv(chan, control, skb, event);
6347 break;
6348 case L2CAP_RX_STATE_SREJ_SENT:
6349 err = l2cap_rx_state_srej_sent(chan, control, skb,
6350 event);
6351 break;
6352 case L2CAP_RX_STATE_WAIT_P:
6353 err = l2cap_rx_state_wait_p(chan, control, skb, event);
6354 break;
6355 case L2CAP_RX_STATE_WAIT_F:
6356 err = l2cap_rx_state_wait_f(chan, control, skb, event);
6357 break;
6358 default:
6359 /* shut it down */
6360 break;
6361 }
6362 } else {
6363 BT_DBG("Invalid reqseq %d (next_tx_seq %d, expected_ack_seq %d",
6364 control->reqseq, chan->next_tx_seq,
6365 chan->expected_ack_seq);
6366 l2cap_send_disconn_req(chan, ECONNRESET);
6367 }
6368
6369 return err;
6370}
6371
6372static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
6373 struct sk_buff *skb)
6374{
6375 /* l2cap_reassemble_sdu may free skb, hence invalidate control, so store
6376 * the txseq field in advance to use it after l2cap_reassemble_sdu
6377 * returns and to avoid the race condition, for example:
6378 *
6379 * The current thread calls:
6380 * l2cap_reassemble_sdu
6381 * chan->ops->recv == l2cap_sock_recv_cb
6382 * __sock_queue_rcv_skb
6383 * Another thread calls:
6384 * bt_sock_recvmsg
6385 * skb_recv_datagram
6386 * skb_free_datagram
6387 * Then the current thread tries to access control, but it was freed by
6388 * skb_free_datagram.
6389 */
6390 u16 txseq = control->txseq;
6391
6392 BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb,
6393 chan->rx_state);
6394
6395 if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) {
6396 l2cap_pass_to_tx(chan, control);
6397
6398 BT_DBG("buffer_seq %u->%u", chan->buffer_seq,
6399 __next_seq(chan, chan->buffer_seq));
6400
6401 chan->buffer_seq = __next_seq(chan, chan->buffer_seq);
6402
6403 l2cap_reassemble_sdu(chan, skb, control);
6404 } else {
6405 if (chan->sdu) {
6406 kfree_skb(chan->sdu);
6407 chan->sdu = NULL;
6408 }
6409 chan->sdu_last_frag = NULL;
6410 chan->sdu_len = 0;
6411
6412 if (skb) {
6413 BT_DBG("Freeing %p", skb);
6414 kfree_skb(skb);
6415 }
6416 }
6417
6418 chan->last_acked_seq = txseq;
6419 chan->expected_tx_seq = __next_seq(chan, txseq);
6420
6421 return 0;
6422}
6423
6424static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
6425{
6426 struct l2cap_ctrl *control = &bt_cb(skb)->l2cap;
6427 u16 len;
6428 u8 event;
6429
6430 __unpack_control(chan, skb);
6431
6432 len = skb->len;
6433
6434 /*
6435 * We can just drop the corrupted I-frame here.
6436 * Receiver will miss it and start proper recovery
6437 * procedures and ask for retransmission.
6438 */
6439 if (l2cap_check_fcs(chan, skb))
6440 goto drop;
6441
6442 if (!control->sframe && control->sar == L2CAP_SAR_START)
6443 len -= L2CAP_SDULEN_SIZE;
6444
6445 if (chan->fcs == L2CAP_FCS_CRC16)
6446 len -= L2CAP_FCS_SIZE;
6447
6448 if (len > chan->mps) {
6449 l2cap_send_disconn_req(chan, ECONNRESET);
6450 goto drop;
6451 }
6452
6453 if (chan->ops->filter) {
6454 if (chan->ops->filter(chan, skb))
6455 goto drop;
6456 }
6457
6458 if (!control->sframe) {
6459 int err;
6460
6461 BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d",
6462 control->sar, control->reqseq, control->final,
6463 control->txseq);
6464
6465 /* Validate F-bit - F=0 always valid, F=1 only
6466 * valid in TX WAIT_F
6467 */
6468 if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F)
6469 goto drop;
6470
6471 if (chan->mode != L2CAP_MODE_STREAMING) {
6472 event = L2CAP_EV_RECV_IFRAME;
6473 err = l2cap_rx(chan, control, skb, event);
6474 } else {
6475 err = l2cap_stream_rx(chan, control, skb);
6476 }
6477
6478 if (err)
6479 l2cap_send_disconn_req(chan, ECONNRESET);
6480 } else {
6481 const u8 rx_func_to_event[4] = {
6482 L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ,
6483 L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ
6484 };
6485
6486 /* Only I-frames are expected in streaming mode */
6487 if (chan->mode == L2CAP_MODE_STREAMING)
6488 goto drop;
6489
6490 BT_DBG("sframe reqseq %d, final %d, poll %d, super %d",
6491 control->reqseq, control->final, control->poll,
6492 control->super);
6493
6494 if (len != 0) {
6495 BT_ERR("Trailing bytes: %d in sframe", len);
6496 l2cap_send_disconn_req(chan, ECONNRESET);
6497 goto drop;
6498 }
6499
6500 /* Validate F and P bits */
6501 if (control->final && (control->poll ||
6502 chan->tx_state != L2CAP_TX_STATE_WAIT_F))
6503 goto drop;
6504
6505 event = rx_func_to_event[control->super];
6506 if (l2cap_rx(chan, control, skb, event))
6507 l2cap_send_disconn_req(chan, ECONNRESET);
6508 }
6509
6510 return 0;
6511
6512drop:
6513 kfree_skb(skb);
6514 return 0;
6515}
6516
6517static void l2cap_chan_le_send_credits(struct l2cap_chan *chan)
6518{
6519 struct l2cap_conn *conn = chan->conn;
6520 struct l2cap_le_credits pkt;
6521 u16 return_credits = l2cap_le_rx_credits(chan);
6522
6523 if (chan->rx_credits >= return_credits)
6524 return;
6525
6526 return_credits -= chan->rx_credits;
6527
6528 BT_DBG("chan %p returning %u credits to sender", chan, return_credits);
6529
6530 chan->rx_credits += return_credits;
6531
6532 pkt.cid = cpu_to_le16(chan->scid);
6533 pkt.credits = cpu_to_le16(return_credits);
6534
6535 chan->ident = l2cap_get_ident(conn);
6536
6537 l2cap_send_cmd(conn, chan->ident, L2CAP_LE_CREDITS, sizeof(pkt), &pkt);
6538}
6539
6540void l2cap_chan_rx_avail(struct l2cap_chan *chan, ssize_t rx_avail)
6541{
6542 if (chan->rx_avail == rx_avail)
6543 return;
6544
6545 BT_DBG("chan %p has %zd bytes avail for rx", chan, rx_avail);
6546
6547 chan->rx_avail = rx_avail;
6548
6549 if (chan->state == BT_CONNECTED)
6550 l2cap_chan_le_send_credits(chan);
6551}
6552
6553static int l2cap_ecred_recv(struct l2cap_chan *chan, struct sk_buff *skb)
6554{
6555 int err;
6556
6557 BT_DBG("SDU reassemble complete: chan %p skb->len %u", chan, skb->len);
6558
6559 /* Wait recv to confirm reception before updating the credits */
6560 err = chan->ops->recv(chan, skb);
6561
6562 if (err < 0 && chan->rx_avail != -1) {
6563 BT_ERR("Queueing received LE L2CAP data failed");
6564 l2cap_send_disconn_req(chan, ECONNRESET);
6565 return err;
6566 }
6567
6568 /* Update credits whenever an SDU is received */
6569 l2cap_chan_le_send_credits(chan);
6570
6571 return err;
6572}
6573
6574static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
6575{
6576 int err;
6577
6578 if (!chan->rx_credits) {
6579 BT_ERR("No credits to receive LE L2CAP data");
6580 l2cap_send_disconn_req(chan, ECONNRESET);
6581 return -ENOBUFS;
6582 }
6583
6584 if (chan->imtu < skb->len) {
6585 BT_ERR("Too big LE L2CAP PDU");
6586 return -ENOBUFS;
6587 }
6588
6589 chan->rx_credits--;
6590 BT_DBG("chan %p: rx_credits %u -> %u",
6591 chan, chan->rx_credits + 1, chan->rx_credits);
6592
6593 /* Update if remote had run out of credits, this should only happens
6594 * if the remote is not using the entire MPS.
6595 */
6596 if (!chan->rx_credits)
6597 l2cap_chan_le_send_credits(chan);
6598
6599 err = 0;
6600
6601 if (!chan->sdu) {
6602 u16 sdu_len;
6603
6604 sdu_len = get_unaligned_le16(skb->data);
6605 skb_pull(skb, L2CAP_SDULEN_SIZE);
6606
6607 BT_DBG("Start of new SDU. sdu_len %u skb->len %u imtu %u",
6608 sdu_len, skb->len, chan->imtu);
6609
6610 if (sdu_len > chan->imtu) {
6611 BT_ERR("Too big LE L2CAP SDU length received");
6612 err = -EMSGSIZE;
6613 goto failed;
6614 }
6615
6616 if (skb->len > sdu_len) {
6617 BT_ERR("Too much LE L2CAP data received");
6618 err = -EINVAL;
6619 goto failed;
6620 }
6621
6622 if (skb->len == sdu_len)
6623 return l2cap_ecred_recv(chan, skb);
6624
6625 chan->sdu = skb;
6626 chan->sdu_len = sdu_len;
6627 chan->sdu_last_frag = skb;
6628
6629 /* Detect if remote is not able to use the selected MPS */
6630 if (skb->len + L2CAP_SDULEN_SIZE < chan->mps) {
6631 u16 mps_len = skb->len + L2CAP_SDULEN_SIZE;
6632
6633 /* Adjust the number of credits */
6634 BT_DBG("chan->mps %u -> %u", chan->mps, mps_len);
6635 chan->mps = mps_len;
6636 l2cap_chan_le_send_credits(chan);
6637 }
6638
6639 return 0;
6640 }
6641
6642 BT_DBG("SDU fragment. chan->sdu->len %u skb->len %u chan->sdu_len %u",
6643 chan->sdu->len, skb->len, chan->sdu_len);
6644
6645 if (chan->sdu->len + skb->len > chan->sdu_len) {
6646 BT_ERR("Too much LE L2CAP data received");
6647 err = -EINVAL;
6648 goto failed;
6649 }
6650
6651 append_skb_frag(chan->sdu, skb, &chan->sdu_last_frag);
6652 skb = NULL;
6653
6654 if (chan->sdu->len == chan->sdu_len) {
6655 err = l2cap_ecred_recv(chan, chan->sdu);
6656 if (!err) {
6657 chan->sdu = NULL;
6658 chan->sdu_last_frag = NULL;
6659 chan->sdu_len = 0;
6660 }
6661 }
6662
6663failed:
6664 if (err) {
6665 kfree_skb(skb);
6666 kfree_skb(chan->sdu);
6667 chan->sdu = NULL;
6668 chan->sdu_last_frag = NULL;
6669 chan->sdu_len = 0;
6670 }
6671
6672 /* We can't return an error here since we took care of the skb
6673 * freeing internally. An error return would cause the caller to
6674 * do a double-free of the skb.
6675 */
6676 return 0;
6677}
6678
6679static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,
6680 struct sk_buff *skb)
6681{
6682 struct l2cap_chan *chan;
6683
6684 chan = l2cap_get_chan_by_scid(conn, cid);
6685 if (!chan) {
6686 BT_DBG("unknown cid 0x%4.4x", cid);
6687 /* Drop packet and return */
6688 kfree_skb(skb);
6689 return;
6690 }
6691
6692 BT_DBG("chan %p, len %d", chan, skb->len);
6693
6694 /* If we receive data on a fixed channel before the info req/rsp
6695 * procedure is done simply assume that the channel is supported
6696 * and mark it as ready.
6697 */
6698 if (chan->chan_type == L2CAP_CHAN_FIXED)
6699 l2cap_chan_ready(chan);
6700
6701 if (chan->state != BT_CONNECTED)
6702 goto drop;
6703
6704 switch (chan->mode) {
6705 case L2CAP_MODE_LE_FLOWCTL:
6706 case L2CAP_MODE_EXT_FLOWCTL:
6707 if (l2cap_ecred_data_rcv(chan, skb) < 0)
6708 goto drop;
6709
6710 goto done;
6711
6712 case L2CAP_MODE_BASIC:
6713 /* If socket recv buffers overflows we drop data here
6714 * which is *bad* because L2CAP has to be reliable.
6715 * But we don't have any other choice. L2CAP doesn't
6716 * provide flow control mechanism. */
6717
6718 if (chan->imtu < skb->len) {
6719 BT_ERR("Dropping L2CAP data: receive buffer overflow");
6720 goto drop;
6721 }
6722
6723 if (!chan->ops->recv(chan, skb))
6724 goto done;
6725 break;
6726
6727 case L2CAP_MODE_ERTM:
6728 case L2CAP_MODE_STREAMING:
6729 l2cap_data_rcv(chan, skb);
6730 goto done;
6731
6732 default:
6733 BT_DBG("chan %p: bad mode 0x%2.2x", chan, chan->mode);
6734 break;
6735 }
6736
6737drop:
6738 kfree_skb(skb);
6739
6740done:
6741 l2cap_chan_unlock(chan);
6742 l2cap_chan_put(chan);
6743}
6744
6745static void l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm,
6746 struct sk_buff *skb)
6747{
6748 struct hci_conn *hcon = conn->hcon;
6749 struct l2cap_chan *chan;
6750
6751 if (hcon->type != ACL_LINK)
6752 goto free_skb;
6753
6754 chan = l2cap_global_chan_by_psm(0, psm, &hcon->src, &hcon->dst,
6755 ACL_LINK);
6756 if (!chan)
6757 goto free_skb;
6758
6759 BT_DBG("chan %p, len %d", chan, skb->len);
6760
6761 l2cap_chan_lock(chan);
6762
6763 if (chan->state != BT_BOUND && chan->state != BT_CONNECTED)
6764 goto drop;
6765
6766 if (chan->imtu < skb->len)
6767 goto drop;
6768
6769 /* Store remote BD_ADDR and PSM for msg_name */
6770 bacpy(&bt_cb(skb)->l2cap.bdaddr, &hcon->dst);
6771 bt_cb(skb)->l2cap.psm = psm;
6772
6773 if (!chan->ops->recv(chan, skb)) {
6774 l2cap_chan_unlock(chan);
6775 l2cap_chan_put(chan);
6776 return;
6777 }
6778
6779drop:
6780 l2cap_chan_unlock(chan);
6781 l2cap_chan_put(chan);
6782free_skb:
6783 kfree_skb(skb);
6784}
6785
6786static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb)
6787{
6788 struct l2cap_hdr *lh = (void *) skb->data;
6789 struct hci_conn *hcon = conn->hcon;
6790 u16 cid, len;
6791 __le16 psm;
6792
6793 if (hcon->state != BT_CONNECTED) {
6794 BT_DBG("queueing pending rx skb");
6795 skb_queue_tail(&conn->pending_rx, skb);
6796 return;
6797 }
6798
6799 skb_pull(skb, L2CAP_HDR_SIZE);
6800 cid = __le16_to_cpu(lh->cid);
6801 len = __le16_to_cpu(lh->len);
6802
6803 if (len != skb->len) {
6804 kfree_skb(skb);
6805 return;
6806 }
6807
6808 /* Since we can't actively block incoming LE connections we must
6809 * at least ensure that we ignore incoming data from them.
6810 */
6811 if (hcon->type == LE_LINK &&
6812 hci_bdaddr_list_lookup(&hcon->hdev->reject_list, &hcon->dst,
6813 bdaddr_dst_type(hcon))) {
6814 kfree_skb(skb);
6815 return;
6816 }
6817
6818 BT_DBG("len %d, cid 0x%4.4x", len, cid);
6819
6820 switch (cid) {
6821 case L2CAP_CID_SIGNALING:
6822 l2cap_sig_channel(conn, skb);
6823 break;
6824
6825 case L2CAP_CID_CONN_LESS:
6826 psm = get_unaligned((__le16 *) skb->data);
6827 skb_pull(skb, L2CAP_PSMLEN_SIZE);
6828 l2cap_conless_channel(conn, psm, skb);
6829 break;
6830
6831 case L2CAP_CID_LE_SIGNALING:
6832 l2cap_le_sig_channel(conn, skb);
6833 break;
6834
6835 default:
6836 l2cap_data_channel(conn, cid, skb);
6837 break;
6838 }
6839}
6840
6841static void process_pending_rx(struct work_struct *work)
6842{
6843 struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
6844 pending_rx_work);
6845 struct sk_buff *skb;
6846
6847 BT_DBG("");
6848
6849 while ((skb = skb_dequeue(&conn->pending_rx)))
6850 l2cap_recv_frame(conn, skb);
6851}
6852
6853static struct l2cap_conn *l2cap_conn_add(struct hci_conn *hcon)
6854{
6855 struct l2cap_conn *conn = hcon->l2cap_data;
6856 struct hci_chan *hchan;
6857
6858 if (conn)
6859 return conn;
6860
6861 hchan = hci_chan_create(hcon);
6862 if (!hchan)
6863 return NULL;
6864
6865 conn = kzalloc(sizeof(*conn), GFP_KERNEL);
6866 if (!conn) {
6867 hci_chan_del(hchan);
6868 return NULL;
6869 }
6870
6871 kref_init(&conn->ref);
6872 hcon->l2cap_data = conn;
6873 conn->hcon = hci_conn_get(hcon);
6874 conn->hchan = hchan;
6875
6876 BT_DBG("hcon %p conn %p hchan %p", hcon, conn, hchan);
6877
6878 conn->mtu = hcon->mtu;
6879 conn->feat_mask = 0;
6880
6881 conn->local_fixed_chan = L2CAP_FC_SIG_BREDR | L2CAP_FC_CONNLESS;
6882
6883 if (hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED) &&
6884 (bredr_sc_enabled(hcon->hdev) ||
6885 hci_dev_test_flag(hcon->hdev, HCI_FORCE_BREDR_SMP)))
6886 conn->local_fixed_chan |= L2CAP_FC_SMP_BREDR;
6887
6888 mutex_init(&conn->ident_lock);
6889 mutex_init(&conn->chan_lock);
6890
6891 INIT_LIST_HEAD(&conn->chan_l);
6892 INIT_LIST_HEAD(&conn->users);
6893
6894 INIT_DELAYED_WORK(&conn->info_timer, l2cap_info_timeout);
6895
6896 skb_queue_head_init(&conn->pending_rx);
6897 INIT_WORK(&conn->pending_rx_work, process_pending_rx);
6898 INIT_DELAYED_WORK(&conn->id_addr_timer, l2cap_conn_update_id_addr);
6899
6900 conn->disc_reason = HCI_ERROR_REMOTE_USER_TERM;
6901
6902 return conn;
6903}
6904
6905static bool is_valid_psm(u16 psm, u8 dst_type)
6906{
6907 if (!psm)
6908 return false;
6909
6910 if (bdaddr_type_is_le(dst_type))
6911 return (psm <= 0x00ff);
6912
6913 /* PSM must be odd and lsb of upper byte must be 0 */
6914 return ((psm & 0x0101) == 0x0001);
6915}
6916
6917struct l2cap_chan_data {
6918 struct l2cap_chan *chan;
6919 struct pid *pid;
6920 int count;
6921};
6922
6923static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data)
6924{
6925 struct l2cap_chan_data *d = data;
6926 struct pid *pid;
6927
6928 if (chan == d->chan)
6929 return;
6930
6931 if (!test_bit(FLAG_DEFER_SETUP, &chan->flags))
6932 return;
6933
6934 pid = chan->ops->get_peer_pid(chan);
6935
6936 /* Only count deferred channels with the same PID/PSM */
6937 if (d->pid != pid || chan->psm != d->chan->psm || chan->ident ||
6938 chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
6939 return;
6940
6941 d->count++;
6942}
6943
6944int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
6945 bdaddr_t *dst, u8 dst_type, u16 timeout)
6946{
6947 struct l2cap_conn *conn;
6948 struct hci_conn *hcon;
6949 struct hci_dev *hdev;
6950 int err;
6951
6952 BT_DBG("%pMR -> %pMR (type %u) psm 0x%4.4x mode 0x%2.2x", &chan->src,
6953 dst, dst_type, __le16_to_cpu(psm), chan->mode);
6954
6955 hdev = hci_get_route(dst, &chan->src, chan->src_type);
6956 if (!hdev)
6957 return -EHOSTUNREACH;
6958
6959 hci_dev_lock(hdev);
6960
6961 if (!is_valid_psm(__le16_to_cpu(psm), dst_type) && !cid &&
6962 chan->chan_type != L2CAP_CHAN_RAW) {
6963 err = -EINVAL;
6964 goto done;
6965 }
6966
6967 if (chan->chan_type == L2CAP_CHAN_CONN_ORIENTED && !psm) {
6968 err = -EINVAL;
6969 goto done;
6970 }
6971
6972 if (chan->chan_type == L2CAP_CHAN_FIXED && !cid) {
6973 err = -EINVAL;
6974 goto done;
6975 }
6976
6977 switch (chan->mode) {
6978 case L2CAP_MODE_BASIC:
6979 break;
6980 case L2CAP_MODE_LE_FLOWCTL:
6981 break;
6982 case L2CAP_MODE_EXT_FLOWCTL:
6983 if (!enable_ecred) {
6984 err = -EOPNOTSUPP;
6985 goto done;
6986 }
6987 break;
6988 case L2CAP_MODE_ERTM:
6989 case L2CAP_MODE_STREAMING:
6990 if (!disable_ertm)
6991 break;
6992 fallthrough;
6993 default:
6994 err = -EOPNOTSUPP;
6995 goto done;
6996 }
6997
6998 switch (chan->state) {
6999 case BT_CONNECT:
7000 case BT_CONNECT2:
7001 case BT_CONFIG:
7002 /* Already connecting */
7003 err = 0;
7004 goto done;
7005
7006 case BT_CONNECTED:
7007 /* Already connected */
7008 err = -EISCONN;
7009 goto done;
7010
7011 case BT_OPEN:
7012 case BT_BOUND:
7013 /* Can connect */
7014 break;
7015
7016 default:
7017 err = -EBADFD;
7018 goto done;
7019 }
7020
7021 /* Set destination address and psm */
7022 bacpy(&chan->dst, dst);
7023 chan->dst_type = dst_type;
7024
7025 chan->psm = psm;
7026 chan->dcid = cid;
7027
7028 if (bdaddr_type_is_le(dst_type)) {
7029 /* Convert from L2CAP channel address type to HCI address type
7030 */
7031 if (dst_type == BDADDR_LE_PUBLIC)
7032 dst_type = ADDR_LE_DEV_PUBLIC;
7033 else
7034 dst_type = ADDR_LE_DEV_RANDOM;
7035
7036 if (hci_dev_test_flag(hdev, HCI_ADVERTISING))
7037 hcon = hci_connect_le(hdev, dst, dst_type, false,
7038 chan->sec_level, timeout,
7039 HCI_ROLE_SLAVE, 0, 0);
7040 else
7041 hcon = hci_connect_le_scan(hdev, dst, dst_type,
7042 chan->sec_level, timeout,
7043 CONN_REASON_L2CAP_CHAN);
7044
7045 } else {
7046 u8 auth_type = l2cap_get_auth_type(chan);
7047 hcon = hci_connect_acl(hdev, dst, chan->sec_level, auth_type,
7048 CONN_REASON_L2CAP_CHAN, timeout);
7049 }
7050
7051 if (IS_ERR(hcon)) {
7052 err = PTR_ERR(hcon);
7053 goto done;
7054 }
7055
7056 conn = l2cap_conn_add(hcon);
7057 if (!conn) {
7058 hci_conn_drop(hcon);
7059 err = -ENOMEM;
7060 goto done;
7061 }
7062
7063 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) {
7064 struct l2cap_chan_data data;
7065
7066 data.chan = chan;
7067 data.pid = chan->ops->get_peer_pid(chan);
7068 data.count = 1;
7069
7070 l2cap_chan_list(conn, l2cap_chan_by_pid, &data);
7071
7072 /* Check if there isn't too many channels being connected */
7073 if (data.count > L2CAP_ECRED_CONN_SCID_MAX) {
7074 hci_conn_drop(hcon);
7075 err = -EPROTO;
7076 goto done;
7077 }
7078 }
7079
7080 mutex_lock(&conn->chan_lock);
7081 l2cap_chan_lock(chan);
7082
7083 if (cid && __l2cap_get_chan_by_dcid(conn, cid)) {
7084 hci_conn_drop(hcon);
7085 err = -EBUSY;
7086 goto chan_unlock;
7087 }
7088
7089 /* Update source addr of the socket */
7090 bacpy(&chan->src, &hcon->src);
7091 chan->src_type = bdaddr_src_type(hcon);
7092
7093 __l2cap_chan_add(conn, chan);
7094
7095 /* l2cap_chan_add takes its own ref so we can drop this one */
7096 hci_conn_drop(hcon);
7097
7098 l2cap_state_change(chan, BT_CONNECT);
7099 __set_chan_timer(chan, chan->ops->get_sndtimeo(chan));
7100
7101 /* Release chan->sport so that it can be reused by other
7102 * sockets (as it's only used for listening sockets).
7103 */
7104 write_lock(&chan_list_lock);
7105 chan->sport = 0;
7106 write_unlock(&chan_list_lock);
7107
7108 if (hcon->state == BT_CONNECTED) {
7109 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
7110 __clear_chan_timer(chan);
7111 if (l2cap_chan_check_security(chan, true))
7112 l2cap_state_change(chan, BT_CONNECTED);
7113 } else
7114 l2cap_do_start(chan);
7115 }
7116
7117 err = 0;
7118
7119chan_unlock:
7120 l2cap_chan_unlock(chan);
7121 mutex_unlock(&conn->chan_lock);
7122done:
7123 hci_dev_unlock(hdev);
7124 hci_dev_put(hdev);
7125 return err;
7126}
7127EXPORT_SYMBOL_GPL(l2cap_chan_connect);
7128
7129static void l2cap_ecred_reconfigure(struct l2cap_chan *chan)
7130{
7131 struct l2cap_conn *conn = chan->conn;
7132 DEFINE_RAW_FLEX(struct l2cap_ecred_reconf_req, pdu, scid, 1);
7133
7134 pdu->mtu = cpu_to_le16(chan->imtu);
7135 pdu->mps = cpu_to_le16(chan->mps);
7136 pdu->scid[0] = cpu_to_le16(chan->scid);
7137
7138 chan->ident = l2cap_get_ident(conn);
7139
7140 l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ,
7141 sizeof(pdu), &pdu);
7142}
7143
7144int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu)
7145{
7146 if (chan->imtu > mtu)
7147 return -EINVAL;
7148
7149 BT_DBG("chan %p mtu 0x%4.4x", chan, mtu);
7150
7151 chan->imtu = mtu;
7152
7153 l2cap_ecred_reconfigure(chan);
7154
7155 return 0;
7156}
7157
7158/* ---- L2CAP interface with lower layer (HCI) ---- */
7159
7160int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr)
7161{
7162 int exact = 0, lm1 = 0, lm2 = 0;
7163 struct l2cap_chan *c;
7164
7165 BT_DBG("hdev %s, bdaddr %pMR", hdev->name, bdaddr);
7166
7167 /* Find listening sockets and check their link_mode */
7168 read_lock(&chan_list_lock);
7169 list_for_each_entry(c, &chan_list, global_l) {
7170 if (c->state != BT_LISTEN)
7171 continue;
7172
7173 if (!bacmp(&c->src, &hdev->bdaddr)) {
7174 lm1 |= HCI_LM_ACCEPT;
7175 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
7176 lm1 |= HCI_LM_MASTER;
7177 exact++;
7178 } else if (!bacmp(&c->src, BDADDR_ANY)) {
7179 lm2 |= HCI_LM_ACCEPT;
7180 if (test_bit(FLAG_ROLE_SWITCH, &c->flags))
7181 lm2 |= HCI_LM_MASTER;
7182 }
7183 }
7184 read_unlock(&chan_list_lock);
7185
7186 return exact ? lm1 : lm2;
7187}
7188
7189/* Find the next fixed channel in BT_LISTEN state, continue iteration
7190 * from an existing channel in the list or from the beginning of the
7191 * global list (by passing NULL as first parameter).
7192 */
7193static struct l2cap_chan *l2cap_global_fixed_chan(struct l2cap_chan *c,
7194 struct hci_conn *hcon)
7195{
7196 u8 src_type = bdaddr_src_type(hcon);
7197
7198 read_lock(&chan_list_lock);
7199
7200 if (c)
7201 c = list_next_entry(c, global_l);
7202 else
7203 c = list_entry(chan_list.next, typeof(*c), global_l);
7204
7205 list_for_each_entry_from(c, &chan_list, global_l) {
7206 if (c->chan_type != L2CAP_CHAN_FIXED)
7207 continue;
7208 if (c->state != BT_LISTEN)
7209 continue;
7210 if (bacmp(&c->src, &hcon->src) && bacmp(&c->src, BDADDR_ANY))
7211 continue;
7212 if (src_type != c->src_type)
7213 continue;
7214
7215 c = l2cap_chan_hold_unless_zero(c);
7216 read_unlock(&chan_list_lock);
7217 return c;
7218 }
7219
7220 read_unlock(&chan_list_lock);
7221
7222 return NULL;
7223}
7224
7225static bool l2cap_match(struct hci_conn *hcon)
7226{
7227 return hcon->type == ACL_LINK || hcon->type == LE_LINK;
7228}
7229
7230static void l2cap_connect_cfm(struct hci_conn *hcon, u8 status)
7231{
7232 struct hci_dev *hdev = hcon->hdev;
7233 struct l2cap_conn *conn;
7234 struct l2cap_chan *pchan;
7235 u8 dst_type;
7236
7237 BT_DBG("hcon %p bdaddr %pMR status %d", hcon, &hcon->dst, status);
7238
7239 if (status) {
7240 l2cap_conn_del(hcon, bt_to_errno(status));
7241 return;
7242 }
7243
7244 conn = l2cap_conn_add(hcon);
7245 if (!conn)
7246 return;
7247
7248 dst_type = bdaddr_dst_type(hcon);
7249
7250 /* If device is blocked, do not create channels for it */
7251 if (hci_bdaddr_list_lookup(&hdev->reject_list, &hcon->dst, dst_type))
7252 return;
7253
7254 /* Find fixed channels and notify them of the new connection. We
7255 * use multiple individual lookups, continuing each time where
7256 * we left off, because the list lock would prevent calling the
7257 * potentially sleeping l2cap_chan_lock() function.
7258 */
7259 pchan = l2cap_global_fixed_chan(NULL, hcon);
7260 while (pchan) {
7261 struct l2cap_chan *chan, *next;
7262
7263 /* Client fixed channels should override server ones */
7264 if (__l2cap_get_chan_by_dcid(conn, pchan->scid))
7265 goto next;
7266
7267 l2cap_chan_lock(pchan);
7268 chan = pchan->ops->new_connection(pchan);
7269 if (chan) {
7270 bacpy(&chan->src, &hcon->src);
7271 bacpy(&chan->dst, &hcon->dst);
7272 chan->src_type = bdaddr_src_type(hcon);
7273 chan->dst_type = dst_type;
7274
7275 __l2cap_chan_add(conn, chan);
7276 }
7277
7278 l2cap_chan_unlock(pchan);
7279next:
7280 next = l2cap_global_fixed_chan(pchan, hcon);
7281 l2cap_chan_put(pchan);
7282 pchan = next;
7283 }
7284
7285 l2cap_conn_ready(conn);
7286}
7287
7288int l2cap_disconn_ind(struct hci_conn *hcon)
7289{
7290 struct l2cap_conn *conn = hcon->l2cap_data;
7291
7292 BT_DBG("hcon %p", hcon);
7293
7294 if (!conn)
7295 return HCI_ERROR_REMOTE_USER_TERM;
7296 return conn->disc_reason;
7297}
7298
7299static void l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)
7300{
7301 BT_DBG("hcon %p reason %d", hcon, reason);
7302
7303 l2cap_conn_del(hcon, bt_to_errno(reason));
7304}
7305
7306static inline void l2cap_check_encryption(struct l2cap_chan *chan, u8 encrypt)
7307{
7308 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED)
7309 return;
7310
7311 if (encrypt == 0x00) {
7312 if (chan->sec_level == BT_SECURITY_MEDIUM) {
7313 __set_chan_timer(chan, L2CAP_ENC_TIMEOUT);
7314 } else if (chan->sec_level == BT_SECURITY_HIGH ||
7315 chan->sec_level == BT_SECURITY_FIPS)
7316 l2cap_chan_close(chan, ECONNREFUSED);
7317 } else {
7318 if (chan->sec_level == BT_SECURITY_MEDIUM)
7319 __clear_chan_timer(chan);
7320 }
7321}
7322
7323static void l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
7324{
7325 struct l2cap_conn *conn = hcon->l2cap_data;
7326 struct l2cap_chan *chan;
7327
7328 if (!conn)
7329 return;
7330
7331 BT_DBG("conn %p status 0x%2.2x encrypt %u", conn, status, encrypt);
7332
7333 mutex_lock(&conn->chan_lock);
7334
7335 list_for_each_entry(chan, &conn->chan_l, list) {
7336 l2cap_chan_lock(chan);
7337
7338 BT_DBG("chan %p scid 0x%4.4x state %s", chan, chan->scid,
7339 state_to_string(chan->state));
7340
7341 if (!status && encrypt)
7342 chan->sec_level = hcon->sec_level;
7343
7344 if (!__l2cap_no_conn_pending(chan)) {
7345 l2cap_chan_unlock(chan);
7346 continue;
7347 }
7348
7349 if (!status && (chan->state == BT_CONNECTED ||
7350 chan->state == BT_CONFIG)) {
7351 chan->ops->resume(chan);
7352 l2cap_check_encryption(chan, encrypt);
7353 l2cap_chan_unlock(chan);
7354 continue;
7355 }
7356
7357 if (chan->state == BT_CONNECT) {
7358 if (!status && l2cap_check_enc_key_size(hcon))
7359 l2cap_start_connection(chan);
7360 else
7361 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
7362 } else if (chan->state == BT_CONNECT2 &&
7363 !(chan->mode == L2CAP_MODE_EXT_FLOWCTL ||
7364 chan->mode == L2CAP_MODE_LE_FLOWCTL)) {
7365 struct l2cap_conn_rsp rsp;
7366 __u16 res, stat;
7367
7368 if (!status && l2cap_check_enc_key_size(hcon)) {
7369 if (test_bit(FLAG_DEFER_SETUP, &chan->flags)) {
7370 res = L2CAP_CR_PEND;
7371 stat = L2CAP_CS_AUTHOR_PEND;
7372 chan->ops->defer(chan);
7373 } else {
7374 l2cap_state_change(chan, BT_CONFIG);
7375 res = L2CAP_CR_SUCCESS;
7376 stat = L2CAP_CS_NO_INFO;
7377 }
7378 } else {
7379 l2cap_state_change(chan, BT_DISCONN);
7380 __set_chan_timer(chan, L2CAP_DISC_TIMEOUT);
7381 res = L2CAP_CR_SEC_BLOCK;
7382 stat = L2CAP_CS_NO_INFO;
7383 }
7384
7385 rsp.scid = cpu_to_le16(chan->dcid);
7386 rsp.dcid = cpu_to_le16(chan->scid);
7387 rsp.result = cpu_to_le16(res);
7388 rsp.status = cpu_to_le16(stat);
7389 l2cap_send_cmd(conn, chan->ident, L2CAP_CONN_RSP,
7390 sizeof(rsp), &rsp);
7391
7392 if (!test_bit(CONF_REQ_SENT, &chan->conf_state) &&
7393 res == L2CAP_CR_SUCCESS) {
7394 char buf[128];
7395 set_bit(CONF_REQ_SENT, &chan->conf_state);
7396 l2cap_send_cmd(conn, l2cap_get_ident(conn),
7397 L2CAP_CONF_REQ,
7398 l2cap_build_conf_req(chan, buf, sizeof(buf)),
7399 buf);
7400 chan->num_conf_req++;
7401 }
7402 }
7403
7404 l2cap_chan_unlock(chan);
7405 }
7406
7407 mutex_unlock(&conn->chan_lock);
7408}
7409
7410/* Append fragment into frame respecting the maximum len of rx_skb */
7411static int l2cap_recv_frag(struct l2cap_conn *conn, struct sk_buff *skb,
7412 u16 len)
7413{
7414 if (!conn->rx_skb) {
7415 /* Allocate skb for the complete frame (with header) */
7416 conn->rx_skb = bt_skb_alloc(len, GFP_KERNEL);
7417 if (!conn->rx_skb)
7418 return -ENOMEM;
7419 /* Init rx_len */
7420 conn->rx_len = len;
7421 }
7422
7423 /* Copy as much as the rx_skb can hold */
7424 len = min_t(u16, len, skb->len);
7425 skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, len), len);
7426 skb_pull(skb, len);
7427 conn->rx_len -= len;
7428
7429 return len;
7430}
7431
7432static int l2cap_recv_len(struct l2cap_conn *conn, struct sk_buff *skb)
7433{
7434 struct sk_buff *rx_skb;
7435 int len;
7436
7437 /* Append just enough to complete the header */
7438 len = l2cap_recv_frag(conn, skb, L2CAP_LEN_SIZE - conn->rx_skb->len);
7439
7440 /* If header could not be read just continue */
7441 if (len < 0 || conn->rx_skb->len < L2CAP_LEN_SIZE)
7442 return len;
7443
7444 rx_skb = conn->rx_skb;
7445 len = get_unaligned_le16(rx_skb->data);
7446
7447 /* Check if rx_skb has enough space to received all fragments */
7448 if (len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE) <= skb_tailroom(rx_skb)) {
7449 /* Update expected len */
7450 conn->rx_len = len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE);
7451 return L2CAP_LEN_SIZE;
7452 }
7453
7454 /* Reset conn->rx_skb since it will need to be reallocated in order to
7455 * fit all fragments.
7456 */
7457 conn->rx_skb = NULL;
7458
7459 /* Reallocates rx_skb using the exact expected length */
7460 len = l2cap_recv_frag(conn, rx_skb,
7461 len + (L2CAP_HDR_SIZE - L2CAP_LEN_SIZE));
7462 kfree_skb(rx_skb);
7463
7464 return len;
7465}
7466
7467static void l2cap_recv_reset(struct l2cap_conn *conn)
7468{
7469 kfree_skb(conn->rx_skb);
7470 conn->rx_skb = NULL;
7471 conn->rx_len = 0;
7472}
7473
7474void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
7475{
7476 struct l2cap_conn *conn = hcon->l2cap_data;
7477 int len;
7478
7479 if (!conn)
7480 conn = l2cap_conn_add(hcon);
7481
7482 if (!conn)
7483 goto drop;
7484
7485 BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags);
7486
7487 switch (flags) {
7488 case ACL_START:
7489 case ACL_START_NO_FLUSH:
7490 case ACL_COMPLETE:
7491 if (conn->rx_skb) {
7492 BT_ERR("Unexpected start frame (len %d)", skb->len);
7493 l2cap_recv_reset(conn);
7494 l2cap_conn_unreliable(conn, ECOMM);
7495 }
7496
7497 /* Start fragment may not contain the L2CAP length so just
7498 * copy the initial byte when that happens and use conn->mtu as
7499 * expected length.
7500 */
7501 if (skb->len < L2CAP_LEN_SIZE) {
7502 l2cap_recv_frag(conn, skb, conn->mtu);
7503 break;
7504 }
7505
7506 len = get_unaligned_le16(skb->data) + L2CAP_HDR_SIZE;
7507
7508 if (len == skb->len) {
7509 /* Complete frame received */
7510 l2cap_recv_frame(conn, skb);
7511 return;
7512 }
7513
7514 BT_DBG("Start: total len %d, frag len %u", len, skb->len);
7515
7516 if (skb->len > len) {
7517 BT_ERR("Frame is too long (len %u, expected len %d)",
7518 skb->len, len);
7519 l2cap_conn_unreliable(conn, ECOMM);
7520 goto drop;
7521 }
7522
7523 /* Append fragment into frame (with header) */
7524 if (l2cap_recv_frag(conn, skb, len) < 0)
7525 goto drop;
7526
7527 break;
7528
7529 case ACL_CONT:
7530 BT_DBG("Cont: frag len %u (expecting %u)", skb->len, conn->rx_len);
7531
7532 if (!conn->rx_skb) {
7533 BT_ERR("Unexpected continuation frame (len %d)", skb->len);
7534 l2cap_conn_unreliable(conn, ECOMM);
7535 goto drop;
7536 }
7537
7538 /* Complete the L2CAP length if it has not been read */
7539 if (conn->rx_skb->len < L2CAP_LEN_SIZE) {
7540 if (l2cap_recv_len(conn, skb) < 0) {
7541 l2cap_conn_unreliable(conn, ECOMM);
7542 goto drop;
7543 }
7544
7545 /* Header still could not be read just continue */
7546 if (conn->rx_skb->len < L2CAP_LEN_SIZE)
7547 break;
7548 }
7549
7550 if (skb->len > conn->rx_len) {
7551 BT_ERR("Fragment is too long (len %u, expected %u)",
7552 skb->len, conn->rx_len);
7553 l2cap_recv_reset(conn);
7554 l2cap_conn_unreliable(conn, ECOMM);
7555 goto drop;
7556 }
7557
7558 /* Append fragment into frame (with header) */
7559 l2cap_recv_frag(conn, skb, skb->len);
7560
7561 if (!conn->rx_len) {
7562 /* Complete frame received. l2cap_recv_frame
7563 * takes ownership of the skb so set the global
7564 * rx_skb pointer to NULL first.
7565 */
7566 struct sk_buff *rx_skb = conn->rx_skb;
7567 conn->rx_skb = NULL;
7568 l2cap_recv_frame(conn, rx_skb);
7569 }
7570 break;
7571 }
7572
7573drop:
7574 kfree_skb(skb);
7575}
7576
7577static struct hci_cb l2cap_cb = {
7578 .name = "L2CAP",
7579 .match = l2cap_match,
7580 .connect_cfm = l2cap_connect_cfm,
7581 .disconn_cfm = l2cap_disconn_cfm,
7582 .security_cfm = l2cap_security_cfm,
7583};
7584
7585static int l2cap_debugfs_show(struct seq_file *f, void *p)
7586{
7587 struct l2cap_chan *c;
7588
7589 read_lock(&chan_list_lock);
7590
7591 list_for_each_entry(c, &chan_list, global_l) {
7592 seq_printf(f, "%pMR (%u) %pMR (%u) %d %d 0x%4.4x 0x%4.4x %d %d %d %d\n",
7593 &c->src, c->src_type, &c->dst, c->dst_type,
7594 c->state, __le16_to_cpu(c->psm),
7595 c->scid, c->dcid, c->imtu, c->omtu,
7596 c->sec_level, c->mode);
7597 }
7598
7599 read_unlock(&chan_list_lock);
7600
7601 return 0;
7602}
7603
7604DEFINE_SHOW_ATTRIBUTE(l2cap_debugfs);
7605
7606static struct dentry *l2cap_debugfs;
7607
7608int __init l2cap_init(void)
7609{
7610 int err;
7611
7612 err = l2cap_init_sockets();
7613 if (err < 0)
7614 return err;
7615
7616 hci_register_cb(&l2cap_cb);
7617
7618 if (IS_ERR_OR_NULL(bt_debugfs))
7619 return 0;
7620
7621 l2cap_debugfs = debugfs_create_file("l2cap", 0444, bt_debugfs,
7622 NULL, &l2cap_debugfs_fops);
7623
7624 return 0;
7625}
7626
7627void l2cap_exit(void)
7628{
7629 debugfs_remove(l2cap_debugfs);
7630 hci_unregister_cb(&l2cap_cb);
7631 l2cap_cleanup_sockets();
7632}
7633
7634module_param(disable_ertm, bool, 0644);
7635MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode");
7636
7637module_param(enable_ecred, bool, 0644);
7638MODULE_PARM_DESC(enable_ecred, "Enable enhanced credit flow control mode");