xref: /openbmc/linux/net/bluetooth/hci_conn.c (revision f79e4d5f)
1 /*
2    BlueZ - Bluetooth protocol stack for Linux
3    Copyright (c) 2000-2001, 2010, Code Aurora Forum. All rights reserved.
4 
5    Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
6 
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License version 2 as
9    published by the Free Software Foundation;
10 
11    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
12    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
13    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
14    IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
15    CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
16    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 
20    ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
21    COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
22    SOFTWARE IS DISCLAIMED.
23 */
24 
25 /* Bluetooth HCI connection handling. */
26 
27 #include <linux/export.h>
28 #include <linux/debugfs.h>
29 
30 #include <net/bluetooth/bluetooth.h>
31 #include <net/bluetooth/hci_core.h>
32 #include <net/bluetooth/l2cap.h>
33 
34 #include "hci_request.h"
35 #include "smp.h"
36 #include "a2mp.h"
37 
38 struct sco_param {
39 	u16 pkt_type;
40 	u16 max_latency;
41 	u8  retrans_effort;
42 };
43 
44 static const struct sco_param esco_param_cvsd[] = {
45 	{ EDR_ESCO_MASK & ~ESCO_2EV3, 0x000a,	0x01 }, /* S3 */
46 	{ EDR_ESCO_MASK & ~ESCO_2EV3, 0x0007,	0x01 }, /* S2 */
47 	{ EDR_ESCO_MASK | ESCO_EV3,   0x0007,	0x01 }, /* S1 */
48 	{ EDR_ESCO_MASK | ESCO_HV3,   0xffff,	0x01 }, /* D1 */
49 	{ EDR_ESCO_MASK | ESCO_HV1,   0xffff,	0x01 }, /* D0 */
50 };
51 
52 static const struct sco_param sco_param_cvsd[] = {
53 	{ EDR_ESCO_MASK | ESCO_HV3,   0xffff,	0xff }, /* D1 */
54 	{ EDR_ESCO_MASK | ESCO_HV1,   0xffff,	0xff }, /* D0 */
55 };
56 
57 static const struct sco_param esco_param_msbc[] = {
58 	{ EDR_ESCO_MASK & ~ESCO_2EV3, 0x000d,	0x02 }, /* T2 */
59 	{ EDR_ESCO_MASK | ESCO_EV3,   0x0008,	0x02 }, /* T1 */
60 };
61 
62 /* This function requires the caller holds hdev->lock */
63 static void hci_connect_le_scan_cleanup(struct hci_conn *conn)
64 {
65 	struct hci_conn_params *params;
66 	struct hci_dev *hdev = conn->hdev;
67 	struct smp_irk *irk;
68 	bdaddr_t *bdaddr;
69 	u8 bdaddr_type;
70 
71 	bdaddr = &conn->dst;
72 	bdaddr_type = conn->dst_type;
73 
74 	/* Check if we need to convert to identity address */
75 	irk = hci_get_irk(hdev, bdaddr, bdaddr_type);
76 	if (irk) {
77 		bdaddr = &irk->bdaddr;
78 		bdaddr_type = irk->addr_type;
79 	}
80 
81 	params = hci_pend_le_action_lookup(&hdev->pend_le_conns, bdaddr,
82 					   bdaddr_type);
83 	if (!params || !params->explicit_connect)
84 		return;
85 
86 	/* The connection attempt was doing scan for new RPA, and is
87 	 * in scan phase. If params are not associated with any other
88 	 * autoconnect action, remove them completely. If they are, just unmark
89 	 * them as waiting for connection, by clearing explicit_connect field.
90 	 */
91 	params->explicit_connect = false;
92 
93 	list_del_init(&params->action);
94 
95 	switch (params->auto_connect) {
96 	case HCI_AUTO_CONN_EXPLICIT:
97 		hci_conn_params_del(hdev, bdaddr, bdaddr_type);
98 		/* return instead of break to avoid duplicate scan update */
99 		return;
100 	case HCI_AUTO_CONN_DIRECT:
101 	case HCI_AUTO_CONN_ALWAYS:
102 		list_add(&params->action, &hdev->pend_le_conns);
103 		break;
104 	case HCI_AUTO_CONN_REPORT:
105 		list_add(&params->action, &hdev->pend_le_reports);
106 		break;
107 	default:
108 		break;
109 	}
110 
111 	hci_update_background_scan(hdev);
112 }
113 
114 static void hci_conn_cleanup(struct hci_conn *conn)
115 {
116 	struct hci_dev *hdev = conn->hdev;
117 
118 	if (test_bit(HCI_CONN_PARAM_REMOVAL_PEND, &conn->flags))
119 		hci_conn_params_del(conn->hdev, &conn->dst, conn->dst_type);
120 
121 	hci_chan_list_flush(conn);
122 
123 	hci_conn_hash_del(hdev, conn);
124 
125 	if (hdev->notify)
126 		hdev->notify(hdev, HCI_NOTIFY_CONN_DEL);
127 
128 	hci_conn_del_sysfs(conn);
129 
130 	debugfs_remove_recursive(conn->debugfs);
131 
132 	hci_dev_put(hdev);
133 
134 	hci_conn_put(conn);
135 }
136 
137 static void le_scan_cleanup(struct work_struct *work)
138 {
139 	struct hci_conn *conn = container_of(work, struct hci_conn,
140 					     le_scan_cleanup);
141 	struct hci_dev *hdev = conn->hdev;
142 	struct hci_conn *c = NULL;
143 
144 	BT_DBG("%s hcon %p", hdev->name, conn);
145 
146 	hci_dev_lock(hdev);
147 
148 	/* Check that the hci_conn is still around */
149 	rcu_read_lock();
150 	list_for_each_entry_rcu(c, &hdev->conn_hash.list, list) {
151 		if (c == conn)
152 			break;
153 	}
154 	rcu_read_unlock();
155 
156 	if (c == conn) {
157 		hci_connect_le_scan_cleanup(conn);
158 		hci_conn_cleanup(conn);
159 	}
160 
161 	hci_dev_unlock(hdev);
162 	hci_dev_put(hdev);
163 	hci_conn_put(conn);
164 }
165 
166 static void hci_connect_le_scan_remove(struct hci_conn *conn)
167 {
168 	BT_DBG("%s hcon %p", conn->hdev->name, conn);
169 
170 	/* We can't call hci_conn_del/hci_conn_cleanup here since that
171 	 * could deadlock with another hci_conn_del() call that's holding
172 	 * hci_dev_lock and doing cancel_delayed_work_sync(&conn->disc_work).
173 	 * Instead, grab temporary extra references to the hci_dev and
174 	 * hci_conn and perform the necessary cleanup in a separate work
175 	 * callback.
176 	 */
177 
178 	hci_dev_hold(conn->hdev);
179 	hci_conn_get(conn);
180 
181 	/* Even though we hold a reference to the hdev, many other
182 	 * things might get cleaned up meanwhile, including the hdev's
183 	 * own workqueue, so we can't use that for scheduling.
184 	 */
185 	schedule_work(&conn->le_scan_cleanup);
186 }
187 
188 static void hci_acl_create_connection(struct hci_conn *conn)
189 {
190 	struct hci_dev *hdev = conn->hdev;
191 	struct inquiry_entry *ie;
192 	struct hci_cp_create_conn cp;
193 
194 	BT_DBG("hcon %p", conn);
195 
196 	conn->state = BT_CONNECT;
197 	conn->out = true;
198 	conn->role = HCI_ROLE_MASTER;
199 
200 	conn->attempt++;
201 
202 	conn->link_policy = hdev->link_policy;
203 
204 	memset(&cp, 0, sizeof(cp));
205 	bacpy(&cp.bdaddr, &conn->dst);
206 	cp.pscan_rep_mode = 0x02;
207 
208 	ie = hci_inquiry_cache_lookup(hdev, &conn->dst);
209 	if (ie) {
210 		if (inquiry_entry_age(ie) <= INQUIRY_ENTRY_AGE_MAX) {
211 			cp.pscan_rep_mode = ie->data.pscan_rep_mode;
212 			cp.pscan_mode     = ie->data.pscan_mode;
213 			cp.clock_offset   = ie->data.clock_offset |
214 					    cpu_to_le16(0x8000);
215 		}
216 
217 		memcpy(conn->dev_class, ie->data.dev_class, 3);
218 		if (ie->data.ssp_mode > 0)
219 			set_bit(HCI_CONN_SSP_ENABLED, &conn->flags);
220 	}
221 
222 	cp.pkt_type = cpu_to_le16(conn->pkt_type);
223 	if (lmp_rswitch_capable(hdev) && !(hdev->link_mode & HCI_LM_MASTER))
224 		cp.role_switch = 0x01;
225 	else
226 		cp.role_switch = 0x00;
227 
228 	hci_send_cmd(hdev, HCI_OP_CREATE_CONN, sizeof(cp), &cp);
229 }
230 
231 int hci_disconnect(struct hci_conn *conn, __u8 reason)
232 {
233 	BT_DBG("hcon %p", conn);
234 
235 	/* When we are master of an established connection and it enters
236 	 * the disconnect timeout, then go ahead and try to read the
237 	 * current clock offset.  Processing of the result is done
238 	 * within the event handling and hci_clock_offset_evt function.
239 	 */
240 	if (conn->type == ACL_LINK && conn->role == HCI_ROLE_MASTER &&
241 	    (conn->state == BT_CONNECTED || conn->state == BT_CONFIG)) {
242 		struct hci_dev *hdev = conn->hdev;
243 		struct hci_cp_read_clock_offset clkoff_cp;
244 
245 		clkoff_cp.handle = cpu_to_le16(conn->handle);
246 		hci_send_cmd(hdev, HCI_OP_READ_CLOCK_OFFSET, sizeof(clkoff_cp),
247 			     &clkoff_cp);
248 	}
249 
250 	return hci_abort_conn(conn, reason);
251 }
252 
253 static void hci_add_sco(struct hci_conn *conn, __u16 handle)
254 {
255 	struct hci_dev *hdev = conn->hdev;
256 	struct hci_cp_add_sco cp;
257 
258 	BT_DBG("hcon %p", conn);
259 
260 	conn->state = BT_CONNECT;
261 	conn->out = true;
262 
263 	conn->attempt++;
264 
265 	cp.handle   = cpu_to_le16(handle);
266 	cp.pkt_type = cpu_to_le16(conn->pkt_type);
267 
268 	hci_send_cmd(hdev, HCI_OP_ADD_SCO, sizeof(cp), &cp);
269 }
270 
271 bool hci_setup_sync(struct hci_conn *conn, __u16 handle)
272 {
273 	struct hci_dev *hdev = conn->hdev;
274 	struct hci_cp_setup_sync_conn cp;
275 	const struct sco_param *param;
276 
277 	BT_DBG("hcon %p", conn);
278 
279 	conn->state = BT_CONNECT;
280 	conn->out = true;
281 
282 	conn->attempt++;
283 
284 	cp.handle   = cpu_to_le16(handle);
285 
286 	cp.tx_bandwidth   = cpu_to_le32(0x00001f40);
287 	cp.rx_bandwidth   = cpu_to_le32(0x00001f40);
288 	cp.voice_setting  = cpu_to_le16(conn->setting);
289 
290 	switch (conn->setting & SCO_AIRMODE_MASK) {
291 	case SCO_AIRMODE_TRANSP:
292 		if (conn->attempt > ARRAY_SIZE(esco_param_msbc))
293 			return false;
294 		param = &esco_param_msbc[conn->attempt - 1];
295 		break;
296 	case SCO_AIRMODE_CVSD:
297 		if (lmp_esco_capable(conn->link)) {
298 			if (conn->attempt > ARRAY_SIZE(esco_param_cvsd))
299 				return false;
300 			param = &esco_param_cvsd[conn->attempt - 1];
301 		} else {
302 			if (conn->attempt > ARRAY_SIZE(sco_param_cvsd))
303 				return false;
304 			param = &sco_param_cvsd[conn->attempt - 1];
305 		}
306 		break;
307 	default:
308 		return false;
309 	}
310 
311 	cp.retrans_effort = param->retrans_effort;
312 	cp.pkt_type = __cpu_to_le16(param->pkt_type);
313 	cp.max_latency = __cpu_to_le16(param->max_latency);
314 
315 	if (hci_send_cmd(hdev, HCI_OP_SETUP_SYNC_CONN, sizeof(cp), &cp) < 0)
316 		return false;
317 
318 	return true;
319 }
320 
321 u8 hci_le_conn_update(struct hci_conn *conn, u16 min, u16 max, u16 latency,
322 		      u16 to_multiplier)
323 {
324 	struct hci_dev *hdev = conn->hdev;
325 	struct hci_conn_params *params;
326 	struct hci_cp_le_conn_update cp;
327 
328 	hci_dev_lock(hdev);
329 
330 	params = hci_conn_params_lookup(hdev, &conn->dst, conn->dst_type);
331 	if (params) {
332 		params->conn_min_interval = min;
333 		params->conn_max_interval = max;
334 		params->conn_latency = latency;
335 		params->supervision_timeout = to_multiplier;
336 	}
337 
338 	hci_dev_unlock(hdev);
339 
340 	memset(&cp, 0, sizeof(cp));
341 	cp.handle		= cpu_to_le16(conn->handle);
342 	cp.conn_interval_min	= cpu_to_le16(min);
343 	cp.conn_interval_max	= cpu_to_le16(max);
344 	cp.conn_latency		= cpu_to_le16(latency);
345 	cp.supervision_timeout	= cpu_to_le16(to_multiplier);
346 	cp.min_ce_len		= cpu_to_le16(0x0000);
347 	cp.max_ce_len		= cpu_to_le16(0x0000);
348 
349 	hci_send_cmd(hdev, HCI_OP_LE_CONN_UPDATE, sizeof(cp), &cp);
350 
351 	if (params)
352 		return 0x01;
353 
354 	return 0x00;
355 }
356 
357 void hci_le_start_enc(struct hci_conn *conn, __le16 ediv, __le64 rand,
358 		      __u8 ltk[16], __u8 key_size)
359 {
360 	struct hci_dev *hdev = conn->hdev;
361 	struct hci_cp_le_start_enc cp;
362 
363 	BT_DBG("hcon %p", conn);
364 
365 	memset(&cp, 0, sizeof(cp));
366 
367 	cp.handle = cpu_to_le16(conn->handle);
368 	cp.rand = rand;
369 	cp.ediv = ediv;
370 	memcpy(cp.ltk, ltk, key_size);
371 
372 	hci_send_cmd(hdev, HCI_OP_LE_START_ENC, sizeof(cp), &cp);
373 }
374 
375 /* Device _must_ be locked */
376 void hci_sco_setup(struct hci_conn *conn, __u8 status)
377 {
378 	struct hci_conn *sco = conn->link;
379 
380 	if (!sco)
381 		return;
382 
383 	BT_DBG("hcon %p", conn);
384 
385 	if (!status) {
386 		if (lmp_esco_capable(conn->hdev))
387 			hci_setup_sync(sco, conn->handle);
388 		else
389 			hci_add_sco(sco, conn->handle);
390 	} else {
391 		hci_connect_cfm(sco, status);
392 		hci_conn_del(sco);
393 	}
394 }
395 
396 static void hci_conn_timeout(struct work_struct *work)
397 {
398 	struct hci_conn *conn = container_of(work, struct hci_conn,
399 					     disc_work.work);
400 	int refcnt = atomic_read(&conn->refcnt);
401 
402 	BT_DBG("hcon %p state %s", conn, state_to_string(conn->state));
403 
404 	WARN_ON(refcnt < 0);
405 
406 	/* FIXME: It was observed that in pairing failed scenario, refcnt
407 	 * drops below 0. Probably this is because l2cap_conn_del calls
408 	 * l2cap_chan_del for each channel, and inside l2cap_chan_del conn is
409 	 * dropped. After that loop hci_chan_del is called which also drops
410 	 * conn. For now make sure that ACL is alive if refcnt is higher then 0,
411 	 * otherwise drop it.
412 	 */
413 	if (refcnt > 0)
414 		return;
415 
416 	/* LE connections in scanning state need special handling */
417 	if (conn->state == BT_CONNECT && conn->type == LE_LINK &&
418 	    test_bit(HCI_CONN_SCANNING, &conn->flags)) {
419 		hci_connect_le_scan_remove(conn);
420 		return;
421 	}
422 
423 	hci_abort_conn(conn, hci_proto_disconn_ind(conn));
424 }
425 
426 /* Enter sniff mode */
427 static void hci_conn_idle(struct work_struct *work)
428 {
429 	struct hci_conn *conn = container_of(work, struct hci_conn,
430 					     idle_work.work);
431 	struct hci_dev *hdev = conn->hdev;
432 
433 	BT_DBG("hcon %p mode %d", conn, conn->mode);
434 
435 	if (!lmp_sniff_capable(hdev) || !lmp_sniff_capable(conn))
436 		return;
437 
438 	if (conn->mode != HCI_CM_ACTIVE || !(conn->link_policy & HCI_LP_SNIFF))
439 		return;
440 
441 	if (lmp_sniffsubr_capable(hdev) && lmp_sniffsubr_capable(conn)) {
442 		struct hci_cp_sniff_subrate cp;
443 		cp.handle             = cpu_to_le16(conn->handle);
444 		cp.max_latency        = cpu_to_le16(0);
445 		cp.min_remote_timeout = cpu_to_le16(0);
446 		cp.min_local_timeout  = cpu_to_le16(0);
447 		hci_send_cmd(hdev, HCI_OP_SNIFF_SUBRATE, sizeof(cp), &cp);
448 	}
449 
450 	if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->flags)) {
451 		struct hci_cp_sniff_mode cp;
452 		cp.handle       = cpu_to_le16(conn->handle);
453 		cp.max_interval = cpu_to_le16(hdev->sniff_max_interval);
454 		cp.min_interval = cpu_to_le16(hdev->sniff_min_interval);
455 		cp.attempt      = cpu_to_le16(4);
456 		cp.timeout      = cpu_to_le16(1);
457 		hci_send_cmd(hdev, HCI_OP_SNIFF_MODE, sizeof(cp), &cp);
458 	}
459 }
460 
461 static void hci_conn_auto_accept(struct work_struct *work)
462 {
463 	struct hci_conn *conn = container_of(work, struct hci_conn,
464 					     auto_accept_work.work);
465 
466 	hci_send_cmd(conn->hdev, HCI_OP_USER_CONFIRM_REPLY, sizeof(conn->dst),
467 		     &conn->dst);
468 }
469 
470 static void le_conn_timeout(struct work_struct *work)
471 {
472 	struct hci_conn *conn = container_of(work, struct hci_conn,
473 					     le_conn_timeout.work);
474 	struct hci_dev *hdev = conn->hdev;
475 
476 	BT_DBG("");
477 
478 	/* We could end up here due to having done directed advertising,
479 	 * so clean up the state if necessary. This should however only
480 	 * happen with broken hardware or if low duty cycle was used
481 	 * (which doesn't have a timeout of its own).
482 	 */
483 	if (conn->role == HCI_ROLE_SLAVE) {
484 		u8 enable = 0x00;
485 		hci_send_cmd(hdev, HCI_OP_LE_SET_ADV_ENABLE, sizeof(enable),
486 			     &enable);
487 		hci_le_conn_failed(conn, HCI_ERROR_ADVERTISING_TIMEOUT);
488 		return;
489 	}
490 
491 	hci_abort_conn(conn, HCI_ERROR_REMOTE_USER_TERM);
492 }
493 
494 struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
495 			      u8 role)
496 {
497 	struct hci_conn *conn;
498 
499 	BT_DBG("%s dst %pMR", hdev->name, dst);
500 
501 	conn = kzalloc(sizeof(*conn), GFP_KERNEL);
502 	if (!conn)
503 		return NULL;
504 
505 	bacpy(&conn->dst, dst);
506 	bacpy(&conn->src, &hdev->bdaddr);
507 	conn->hdev  = hdev;
508 	conn->type  = type;
509 	conn->role  = role;
510 	conn->mode  = HCI_CM_ACTIVE;
511 	conn->state = BT_OPEN;
512 	conn->auth_type = HCI_AT_GENERAL_BONDING;
513 	conn->io_capability = hdev->io_capability;
514 	conn->remote_auth = 0xff;
515 	conn->key_type = 0xff;
516 	conn->rssi = HCI_RSSI_INVALID;
517 	conn->tx_power = HCI_TX_POWER_INVALID;
518 	conn->max_tx_power = HCI_TX_POWER_INVALID;
519 
520 	set_bit(HCI_CONN_POWER_SAVE, &conn->flags);
521 	conn->disc_timeout = HCI_DISCONN_TIMEOUT;
522 
523 	if (conn->role == HCI_ROLE_MASTER)
524 		conn->out = true;
525 
526 	switch (type) {
527 	case ACL_LINK:
528 		conn->pkt_type = hdev->pkt_type & ACL_PTYPE_MASK;
529 		break;
530 	case LE_LINK:
531 		/* conn->src should reflect the local identity address */
532 		hci_copy_identity_address(hdev, &conn->src, &conn->src_type);
533 		break;
534 	case SCO_LINK:
535 		if (lmp_esco_capable(hdev))
536 			conn->pkt_type = (hdev->esco_type & SCO_ESCO_MASK) |
537 					(hdev->esco_type & EDR_ESCO_MASK);
538 		else
539 			conn->pkt_type = hdev->pkt_type & SCO_PTYPE_MASK;
540 		break;
541 	case ESCO_LINK:
542 		conn->pkt_type = hdev->esco_type & ~EDR_ESCO_MASK;
543 		break;
544 	}
545 
546 	skb_queue_head_init(&conn->data_q);
547 
548 	INIT_LIST_HEAD(&conn->chan_list);
549 
550 	INIT_DELAYED_WORK(&conn->disc_work, hci_conn_timeout);
551 	INIT_DELAYED_WORK(&conn->auto_accept_work, hci_conn_auto_accept);
552 	INIT_DELAYED_WORK(&conn->idle_work, hci_conn_idle);
553 	INIT_DELAYED_WORK(&conn->le_conn_timeout, le_conn_timeout);
554 	INIT_WORK(&conn->le_scan_cleanup, le_scan_cleanup);
555 
556 	atomic_set(&conn->refcnt, 0);
557 
558 	hci_dev_hold(hdev);
559 
560 	hci_conn_hash_add(hdev, conn);
561 	if (hdev->notify)
562 		hdev->notify(hdev, HCI_NOTIFY_CONN_ADD);
563 
564 	hci_conn_init_sysfs(conn);
565 
566 	return conn;
567 }
568 
569 int hci_conn_del(struct hci_conn *conn)
570 {
571 	struct hci_dev *hdev = conn->hdev;
572 
573 	BT_DBG("%s hcon %p handle %d", hdev->name, conn, conn->handle);
574 
575 	cancel_delayed_work_sync(&conn->disc_work);
576 	cancel_delayed_work_sync(&conn->auto_accept_work);
577 	cancel_delayed_work_sync(&conn->idle_work);
578 
579 	if (conn->type == ACL_LINK) {
580 		struct hci_conn *sco = conn->link;
581 		if (sco)
582 			sco->link = NULL;
583 
584 		/* Unacked frames */
585 		hdev->acl_cnt += conn->sent;
586 	} else if (conn->type == LE_LINK) {
587 		cancel_delayed_work(&conn->le_conn_timeout);
588 
589 		if (hdev->le_pkts)
590 			hdev->le_cnt += conn->sent;
591 		else
592 			hdev->acl_cnt += conn->sent;
593 	} else {
594 		struct hci_conn *acl = conn->link;
595 		if (acl) {
596 			acl->link = NULL;
597 			hci_conn_drop(acl);
598 		}
599 	}
600 
601 	if (conn->amp_mgr)
602 		amp_mgr_put(conn->amp_mgr);
603 
604 	skb_queue_purge(&conn->data_q);
605 
606 	/* Remove the connection from the list and cleanup its remaining
607 	 * state. This is a separate function since for some cases like
608 	 * BT_CONNECT_SCAN we *only* want the cleanup part without the
609 	 * rest of hci_conn_del.
610 	 */
611 	hci_conn_cleanup(conn);
612 
613 	return 0;
614 }
615 
616 struct hci_dev *hci_get_route(bdaddr_t *dst, bdaddr_t *src, uint8_t src_type)
617 {
618 	int use_src = bacmp(src, BDADDR_ANY);
619 	struct hci_dev *hdev = NULL, *d;
620 
621 	BT_DBG("%pMR -> %pMR", src, dst);
622 
623 	read_lock(&hci_dev_list_lock);
624 
625 	list_for_each_entry(d, &hci_dev_list, list) {
626 		if (!test_bit(HCI_UP, &d->flags) ||
627 		    hci_dev_test_flag(d, HCI_USER_CHANNEL) ||
628 		    d->dev_type != HCI_PRIMARY)
629 			continue;
630 
631 		/* Simple routing:
632 		 *   No source address - find interface with bdaddr != dst
633 		 *   Source address    - find interface with bdaddr == src
634 		 */
635 
636 		if (use_src) {
637 			bdaddr_t id_addr;
638 			u8 id_addr_type;
639 
640 			if (src_type == BDADDR_BREDR) {
641 				if (!lmp_bredr_capable(d))
642 					continue;
643 				bacpy(&id_addr, &d->bdaddr);
644 				id_addr_type = BDADDR_BREDR;
645 			} else {
646 				if (!lmp_le_capable(d))
647 					continue;
648 
649 				hci_copy_identity_address(d, &id_addr,
650 							  &id_addr_type);
651 
652 				/* Convert from HCI to three-value type */
653 				if (id_addr_type == ADDR_LE_DEV_PUBLIC)
654 					id_addr_type = BDADDR_LE_PUBLIC;
655 				else
656 					id_addr_type = BDADDR_LE_RANDOM;
657 			}
658 
659 			if (!bacmp(&id_addr, src) && id_addr_type == src_type) {
660 				hdev = d; break;
661 			}
662 		} else {
663 			if (bacmp(&d->bdaddr, dst)) {
664 				hdev = d; break;
665 			}
666 		}
667 	}
668 
669 	if (hdev)
670 		hdev = hci_dev_hold(hdev);
671 
672 	read_unlock(&hci_dev_list_lock);
673 	return hdev;
674 }
675 EXPORT_SYMBOL(hci_get_route);
676 
677 /* This function requires the caller holds hdev->lock */
678 void hci_le_conn_failed(struct hci_conn *conn, u8 status)
679 {
680 	struct hci_dev *hdev = conn->hdev;
681 	struct hci_conn_params *params;
682 
683 	params = hci_pend_le_action_lookup(&hdev->pend_le_conns, &conn->dst,
684 					   conn->dst_type);
685 	if (params && params->conn) {
686 		hci_conn_drop(params->conn);
687 		hci_conn_put(params->conn);
688 		params->conn = NULL;
689 	}
690 
691 	conn->state = BT_CLOSED;
692 
693 	/* If the status indicates successful cancellation of
694 	 * the attempt (i.e. Unkown Connection Id) there's no point of
695 	 * notifying failure since we'll go back to keep trying to
696 	 * connect. The only exception is explicit connect requests
697 	 * where a timeout + cancel does indicate an actual failure.
698 	 */
699 	if (status != HCI_ERROR_UNKNOWN_CONN_ID ||
700 	    (params && params->explicit_connect))
701 		mgmt_connect_failed(hdev, &conn->dst, conn->type,
702 				    conn->dst_type, status);
703 
704 	hci_connect_cfm(conn, status);
705 
706 	hci_conn_del(conn);
707 
708 	/* Since we may have temporarily stopped the background scanning in
709 	 * favor of connection establishment, we should restart it.
710 	 */
711 	hci_update_background_scan(hdev);
712 
713 	/* Re-enable advertising in case this was a failed connection
714 	 * attempt as a peripheral.
715 	 */
716 	hci_req_reenable_advertising(hdev);
717 }
718 
719 static void create_le_conn_complete(struct hci_dev *hdev, u8 status, u16 opcode)
720 {
721 	struct hci_conn *conn;
722 
723 	hci_dev_lock(hdev);
724 
725 	conn = hci_lookup_le_connect(hdev);
726 
727 	if (!status) {
728 		hci_connect_le_scan_cleanup(conn);
729 		goto done;
730 	}
731 
732 	bt_dev_err(hdev, "request failed to create LE connection: "
733 		   "status 0x%2.2x", status);
734 
735 	if (!conn)
736 		goto done;
737 
738 	hci_le_conn_failed(conn, status);
739 
740 done:
741 	hci_dev_unlock(hdev);
742 }
743 
744 static bool conn_use_rpa(struct hci_conn *conn)
745 {
746 	struct hci_dev *hdev = conn->hdev;
747 
748 	return hci_dev_test_flag(hdev, HCI_PRIVACY);
749 }
750 
751 static void hci_req_add_le_create_conn(struct hci_request *req,
752 				       struct hci_conn *conn,
753 				       bdaddr_t *direct_rpa)
754 {
755 	struct hci_cp_le_create_conn cp;
756 	struct hci_dev *hdev = conn->hdev;
757 	u8 own_addr_type;
758 
759 	/* If direct address was provided we use it instead of current
760 	 * address.
761 	 */
762 	if (direct_rpa) {
763 		if (bacmp(&req->hdev->random_addr, direct_rpa))
764 			hci_req_add(req, HCI_OP_LE_SET_RANDOM_ADDR, 6,
765 								direct_rpa);
766 
767 		/* direct address is always RPA */
768 		own_addr_type = ADDR_LE_DEV_RANDOM;
769 	} else {
770 		/* Update random address, but set require_privacy to false so
771 		 * that we never connect with an non-resolvable address.
772 		 */
773 		if (hci_update_random_address(req, false, conn_use_rpa(conn),
774 					      &own_addr_type))
775 			return;
776 	}
777 
778 	memset(&cp, 0, sizeof(cp));
779 
780 	/* Set window to be the same value as the interval to enable
781 	 * continuous scanning.
782 	 */
783 	cp.scan_interval = cpu_to_le16(hdev->le_scan_interval);
784 	cp.scan_window = cp.scan_interval;
785 
786 	bacpy(&cp.peer_addr, &conn->dst);
787 	cp.peer_addr_type = conn->dst_type;
788 	cp.own_address_type = own_addr_type;
789 	cp.conn_interval_min = cpu_to_le16(conn->le_conn_min_interval);
790 	cp.conn_interval_max = cpu_to_le16(conn->le_conn_max_interval);
791 	cp.conn_latency = cpu_to_le16(conn->le_conn_latency);
792 	cp.supervision_timeout = cpu_to_le16(conn->le_supv_timeout);
793 	cp.min_ce_len = cpu_to_le16(0x0000);
794 	cp.max_ce_len = cpu_to_le16(0x0000);
795 
796 	hci_req_add(req, HCI_OP_LE_CREATE_CONN, sizeof(cp), &cp);
797 
798 	conn->state = BT_CONNECT;
799 	clear_bit(HCI_CONN_SCANNING, &conn->flags);
800 }
801 
802 static void hci_req_directed_advertising(struct hci_request *req,
803 					 struct hci_conn *conn)
804 {
805 	struct hci_dev *hdev = req->hdev;
806 	struct hci_cp_le_set_adv_param cp;
807 	u8 own_addr_type;
808 	u8 enable;
809 
810 	/* Clear the HCI_LE_ADV bit temporarily so that the
811 	 * hci_update_random_address knows that it's safe to go ahead
812 	 * and write a new random address. The flag will be set back on
813 	 * as soon as the SET_ADV_ENABLE HCI command completes.
814 	 */
815 	hci_dev_clear_flag(hdev, HCI_LE_ADV);
816 
817 	/* Set require_privacy to false so that the remote device has a
818 	 * chance of identifying us.
819 	 */
820 	if (hci_update_random_address(req, false, conn_use_rpa(conn),
821 				      &own_addr_type) < 0)
822 		return;
823 
824 	memset(&cp, 0, sizeof(cp));
825 	cp.type = LE_ADV_DIRECT_IND;
826 	cp.own_address_type = own_addr_type;
827 	cp.direct_addr_type = conn->dst_type;
828 	bacpy(&cp.direct_addr, &conn->dst);
829 	cp.channel_map = hdev->le_adv_channel_map;
830 
831 	hci_req_add(req, HCI_OP_LE_SET_ADV_PARAM, sizeof(cp), &cp);
832 
833 	enable = 0x01;
834 	hci_req_add(req, HCI_OP_LE_SET_ADV_ENABLE, sizeof(enable), &enable);
835 
836 	conn->state = BT_CONNECT;
837 }
838 
839 struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
840 				u8 dst_type, u8 sec_level, u16 conn_timeout,
841 				u8 role, bdaddr_t *direct_rpa)
842 {
843 	struct hci_conn_params *params;
844 	struct hci_conn *conn;
845 	struct smp_irk *irk;
846 	struct hci_request req;
847 	int err;
848 
849 	/* Let's make sure that le is enabled.*/
850 	if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) {
851 		if (lmp_le_capable(hdev))
852 			return ERR_PTR(-ECONNREFUSED);
853 
854 		return ERR_PTR(-EOPNOTSUPP);
855 	}
856 
857 	/* Since the controller supports only one LE connection attempt at a
858 	 * time, we return -EBUSY if there is any connection attempt running.
859 	 */
860 	if (hci_lookup_le_connect(hdev))
861 		return ERR_PTR(-EBUSY);
862 
863 	/* If there's already a connection object but it's not in
864 	 * scanning state it means it must already be established, in
865 	 * which case we can't do anything else except report a failure
866 	 * to connect.
867 	 */
868 	conn = hci_conn_hash_lookup_le(hdev, dst, dst_type);
869 	if (conn && !test_bit(HCI_CONN_SCANNING, &conn->flags)) {
870 		return ERR_PTR(-EBUSY);
871 	}
872 
873 	/* When given an identity address with existing identity
874 	 * resolving key, the connection needs to be established
875 	 * to a resolvable random address.
876 	 *
877 	 * Storing the resolvable random address is required here
878 	 * to handle connection failures. The address will later
879 	 * be resolved back into the original identity address
880 	 * from the connect request.
881 	 */
882 	irk = hci_find_irk_by_addr(hdev, dst, dst_type);
883 	if (irk && bacmp(&irk->rpa, BDADDR_ANY)) {
884 		dst = &irk->rpa;
885 		dst_type = ADDR_LE_DEV_RANDOM;
886 	}
887 
888 	if (conn) {
889 		bacpy(&conn->dst, dst);
890 	} else {
891 		conn = hci_conn_add(hdev, LE_LINK, dst, role);
892 		if (!conn)
893 			return ERR_PTR(-ENOMEM);
894 		hci_conn_hold(conn);
895 		conn->pending_sec_level = sec_level;
896 	}
897 
898 	conn->dst_type = dst_type;
899 	conn->sec_level = BT_SECURITY_LOW;
900 	conn->conn_timeout = conn_timeout;
901 
902 	hci_req_init(&req, hdev);
903 
904 	/* Disable advertising if we're active. For master role
905 	 * connections most controllers will refuse to connect if
906 	 * advertising is enabled, and for slave role connections we
907 	 * anyway have to disable it in order to start directed
908 	 * advertising.
909 	 */
910 	if (hci_dev_test_flag(hdev, HCI_LE_ADV)) {
911 		u8 enable = 0x00;
912 		hci_req_add(&req, HCI_OP_LE_SET_ADV_ENABLE, sizeof(enable),
913 			    &enable);
914 	}
915 
916 	/* If requested to connect as slave use directed advertising */
917 	if (conn->role == HCI_ROLE_SLAVE) {
918 		/* If we're active scanning most controllers are unable
919 		 * to initiate advertising. Simply reject the attempt.
920 		 */
921 		if (hci_dev_test_flag(hdev, HCI_LE_SCAN) &&
922 		    hdev->le_scan_type == LE_SCAN_ACTIVE) {
923 			hci_req_purge(&req);
924 			hci_conn_del(conn);
925 			return ERR_PTR(-EBUSY);
926 		}
927 
928 		hci_req_directed_advertising(&req, conn);
929 		goto create_conn;
930 	}
931 
932 	params = hci_conn_params_lookup(hdev, &conn->dst, conn->dst_type);
933 	if (params) {
934 		conn->le_conn_min_interval = params->conn_min_interval;
935 		conn->le_conn_max_interval = params->conn_max_interval;
936 		conn->le_conn_latency = params->conn_latency;
937 		conn->le_supv_timeout = params->supervision_timeout;
938 	} else {
939 		conn->le_conn_min_interval = hdev->le_conn_min_interval;
940 		conn->le_conn_max_interval = hdev->le_conn_max_interval;
941 		conn->le_conn_latency = hdev->le_conn_latency;
942 		conn->le_supv_timeout = hdev->le_supv_timeout;
943 	}
944 
945 	/* If controller is scanning, we stop it since some controllers are
946 	 * not able to scan and connect at the same time. Also set the
947 	 * HCI_LE_SCAN_INTERRUPTED flag so that the command complete
948 	 * handler for scan disabling knows to set the correct discovery
949 	 * state.
950 	 */
951 	if (hci_dev_test_flag(hdev, HCI_LE_SCAN)) {
952 		hci_req_add_le_scan_disable(&req);
953 		hci_dev_set_flag(hdev, HCI_LE_SCAN_INTERRUPTED);
954 	}
955 
956 	hci_req_add_le_create_conn(&req, conn, direct_rpa);
957 
958 create_conn:
959 	err = hci_req_run(&req, create_le_conn_complete);
960 	if (err) {
961 		hci_conn_del(conn);
962 		return ERR_PTR(err);
963 	}
964 
965 	return conn;
966 }
967 
968 static bool is_connected(struct hci_dev *hdev, bdaddr_t *addr, u8 type)
969 {
970 	struct hci_conn *conn;
971 
972 	conn = hci_conn_hash_lookup_le(hdev, addr, type);
973 	if (!conn)
974 		return false;
975 
976 	if (conn->state != BT_CONNECTED)
977 		return false;
978 
979 	return true;
980 }
981 
982 /* This function requires the caller holds hdev->lock */
983 static int hci_explicit_conn_params_set(struct hci_dev *hdev,
984 					bdaddr_t *addr, u8 addr_type)
985 {
986 	struct hci_conn_params *params;
987 
988 	if (is_connected(hdev, addr, addr_type))
989 		return -EISCONN;
990 
991 	params = hci_conn_params_lookup(hdev, addr, addr_type);
992 	if (!params) {
993 		params = hci_conn_params_add(hdev, addr, addr_type);
994 		if (!params)
995 			return -ENOMEM;
996 
997 		/* If we created new params, mark them to be deleted in
998 		 * hci_connect_le_scan_cleanup. It's different case than
999 		 * existing disabled params, those will stay after cleanup.
1000 		 */
1001 		params->auto_connect = HCI_AUTO_CONN_EXPLICIT;
1002 	}
1003 
1004 	/* We're trying to connect, so make sure params are at pend_le_conns */
1005 	if (params->auto_connect == HCI_AUTO_CONN_DISABLED ||
1006 	    params->auto_connect == HCI_AUTO_CONN_REPORT ||
1007 	    params->auto_connect == HCI_AUTO_CONN_EXPLICIT) {
1008 		list_del_init(&params->action);
1009 		list_add(&params->action, &hdev->pend_le_conns);
1010 	}
1011 
1012 	params->explicit_connect = true;
1013 
1014 	BT_DBG("addr %pMR (type %u) auto_connect %u", addr, addr_type,
1015 	       params->auto_connect);
1016 
1017 	return 0;
1018 }
1019 
1020 /* This function requires the caller holds hdev->lock */
1021 struct hci_conn *hci_connect_le_scan(struct hci_dev *hdev, bdaddr_t *dst,
1022 				     u8 dst_type, u8 sec_level,
1023 				     u16 conn_timeout)
1024 {
1025 	struct hci_conn *conn;
1026 
1027 	/* Let's make sure that le is enabled.*/
1028 	if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) {
1029 		if (lmp_le_capable(hdev))
1030 			return ERR_PTR(-ECONNREFUSED);
1031 
1032 		return ERR_PTR(-EOPNOTSUPP);
1033 	}
1034 
1035 	/* Some devices send ATT messages as soon as the physical link is
1036 	 * established. To be able to handle these ATT messages, the user-
1037 	 * space first establishes the connection and then starts the pairing
1038 	 * process.
1039 	 *
1040 	 * So if a hci_conn object already exists for the following connection
1041 	 * attempt, we simply update pending_sec_level and auth_type fields
1042 	 * and return the object found.
1043 	 */
1044 	conn = hci_conn_hash_lookup_le(hdev, dst, dst_type);
1045 	if (conn) {
1046 		if (conn->pending_sec_level < sec_level)
1047 			conn->pending_sec_level = sec_level;
1048 		goto done;
1049 	}
1050 
1051 	BT_DBG("requesting refresh of dst_addr");
1052 
1053 	conn = hci_conn_add(hdev, LE_LINK, dst, HCI_ROLE_MASTER);
1054 	if (!conn)
1055 		return ERR_PTR(-ENOMEM);
1056 
1057 	if (hci_explicit_conn_params_set(hdev, dst, dst_type) < 0)
1058 		return ERR_PTR(-EBUSY);
1059 
1060 	conn->state = BT_CONNECT;
1061 	set_bit(HCI_CONN_SCANNING, &conn->flags);
1062 	conn->dst_type = dst_type;
1063 	conn->sec_level = BT_SECURITY_LOW;
1064 	conn->pending_sec_level = sec_level;
1065 	conn->conn_timeout = conn_timeout;
1066 
1067 	hci_update_background_scan(hdev);
1068 
1069 done:
1070 	hci_conn_hold(conn);
1071 	return conn;
1072 }
1073 
1074 struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
1075 				 u8 sec_level, u8 auth_type)
1076 {
1077 	struct hci_conn *acl;
1078 
1079 	if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED)) {
1080 		if (lmp_bredr_capable(hdev))
1081 			return ERR_PTR(-ECONNREFUSED);
1082 
1083 		return ERR_PTR(-EOPNOTSUPP);
1084 	}
1085 
1086 	acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
1087 	if (!acl) {
1088 		acl = hci_conn_add(hdev, ACL_LINK, dst, HCI_ROLE_MASTER);
1089 		if (!acl)
1090 			return ERR_PTR(-ENOMEM);
1091 	}
1092 
1093 	hci_conn_hold(acl);
1094 
1095 	if (acl->state == BT_OPEN || acl->state == BT_CLOSED) {
1096 		acl->sec_level = BT_SECURITY_LOW;
1097 		acl->pending_sec_level = sec_level;
1098 		acl->auth_type = auth_type;
1099 		hci_acl_create_connection(acl);
1100 	}
1101 
1102 	return acl;
1103 }
1104 
1105 struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type, bdaddr_t *dst,
1106 				 __u16 setting)
1107 {
1108 	struct hci_conn *acl;
1109 	struct hci_conn *sco;
1110 
1111 	acl = hci_connect_acl(hdev, dst, BT_SECURITY_LOW, HCI_AT_NO_BONDING);
1112 	if (IS_ERR(acl))
1113 		return acl;
1114 
1115 	sco = hci_conn_hash_lookup_ba(hdev, type, dst);
1116 	if (!sco) {
1117 		sco = hci_conn_add(hdev, type, dst, HCI_ROLE_MASTER);
1118 		if (!sco) {
1119 			hci_conn_drop(acl);
1120 			return ERR_PTR(-ENOMEM);
1121 		}
1122 	}
1123 
1124 	acl->link = sco;
1125 	sco->link = acl;
1126 
1127 	hci_conn_hold(sco);
1128 
1129 	sco->setting = setting;
1130 
1131 	if (acl->state == BT_CONNECTED &&
1132 	    (sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
1133 		set_bit(HCI_CONN_POWER_SAVE, &acl->flags);
1134 		hci_conn_enter_active_mode(acl, BT_POWER_FORCE_ACTIVE_ON);
1135 
1136 		if (test_bit(HCI_CONN_MODE_CHANGE_PEND, &acl->flags)) {
1137 			/* defer SCO setup until mode change completed */
1138 			set_bit(HCI_CONN_SCO_SETUP_PEND, &acl->flags);
1139 			return sco;
1140 		}
1141 
1142 		hci_sco_setup(acl, 0x00);
1143 	}
1144 
1145 	return sco;
1146 }
1147 
1148 /* Check link security requirement */
1149 int hci_conn_check_link_mode(struct hci_conn *conn)
1150 {
1151 	BT_DBG("hcon %p", conn);
1152 
1153 	/* In Secure Connections Only mode, it is required that Secure
1154 	 * Connections is used and the link is encrypted with AES-CCM
1155 	 * using a P-256 authenticated combination key.
1156 	 */
1157 	if (hci_dev_test_flag(conn->hdev, HCI_SC_ONLY)) {
1158 		if (!hci_conn_sc_enabled(conn) ||
1159 		    !test_bit(HCI_CONN_AES_CCM, &conn->flags) ||
1160 		    conn->key_type != HCI_LK_AUTH_COMBINATION_P256)
1161 			return 0;
1162 	}
1163 
1164 	if (hci_conn_ssp_enabled(conn) &&
1165 	    !test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1166 		return 0;
1167 
1168 	return 1;
1169 }
1170 
1171 /* Authenticate remote device */
1172 static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
1173 {
1174 	BT_DBG("hcon %p", conn);
1175 
1176 	if (conn->pending_sec_level > sec_level)
1177 		sec_level = conn->pending_sec_level;
1178 
1179 	if (sec_level > conn->sec_level)
1180 		conn->pending_sec_level = sec_level;
1181 	else if (test_bit(HCI_CONN_AUTH, &conn->flags))
1182 		return 1;
1183 
1184 	/* Make sure we preserve an existing MITM requirement*/
1185 	auth_type |= (conn->auth_type & 0x01);
1186 
1187 	conn->auth_type = auth_type;
1188 
1189 	if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->flags)) {
1190 		struct hci_cp_auth_requested cp;
1191 
1192 		cp.handle = cpu_to_le16(conn->handle);
1193 		hci_send_cmd(conn->hdev, HCI_OP_AUTH_REQUESTED,
1194 			     sizeof(cp), &cp);
1195 
1196 		/* If we're already encrypted set the REAUTH_PEND flag,
1197 		 * otherwise set the ENCRYPT_PEND.
1198 		 */
1199 		if (test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1200 			set_bit(HCI_CONN_REAUTH_PEND, &conn->flags);
1201 		else
1202 			set_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags);
1203 	}
1204 
1205 	return 0;
1206 }
1207 
1208 /* Encrypt the the link */
1209 static void hci_conn_encrypt(struct hci_conn *conn)
1210 {
1211 	BT_DBG("hcon %p", conn);
1212 
1213 	if (!test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags)) {
1214 		struct hci_cp_set_conn_encrypt cp;
1215 		cp.handle  = cpu_to_le16(conn->handle);
1216 		cp.encrypt = 0x01;
1217 		hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT, sizeof(cp),
1218 			     &cp);
1219 	}
1220 }
1221 
1222 /* Enable security */
1223 int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type,
1224 		      bool initiator)
1225 {
1226 	BT_DBG("hcon %p", conn);
1227 
1228 	if (conn->type == LE_LINK)
1229 		return smp_conn_security(conn, sec_level);
1230 
1231 	/* For sdp we don't need the link key. */
1232 	if (sec_level == BT_SECURITY_SDP)
1233 		return 1;
1234 
1235 	/* For non 2.1 devices and low security level we don't need the link
1236 	   key. */
1237 	if (sec_level == BT_SECURITY_LOW && !hci_conn_ssp_enabled(conn))
1238 		return 1;
1239 
1240 	/* For other security levels we need the link key. */
1241 	if (!test_bit(HCI_CONN_AUTH, &conn->flags))
1242 		goto auth;
1243 
1244 	/* An authenticated FIPS approved combination key has sufficient
1245 	 * security for security level 4. */
1246 	if (conn->key_type == HCI_LK_AUTH_COMBINATION_P256 &&
1247 	    sec_level == BT_SECURITY_FIPS)
1248 		goto encrypt;
1249 
1250 	/* An authenticated combination key has sufficient security for
1251 	   security level 3. */
1252 	if ((conn->key_type == HCI_LK_AUTH_COMBINATION_P192 ||
1253 	     conn->key_type == HCI_LK_AUTH_COMBINATION_P256) &&
1254 	    sec_level == BT_SECURITY_HIGH)
1255 		goto encrypt;
1256 
1257 	/* An unauthenticated combination key has sufficient security for
1258 	   security level 1 and 2. */
1259 	if ((conn->key_type == HCI_LK_UNAUTH_COMBINATION_P192 ||
1260 	     conn->key_type == HCI_LK_UNAUTH_COMBINATION_P256) &&
1261 	    (sec_level == BT_SECURITY_MEDIUM || sec_level == BT_SECURITY_LOW))
1262 		goto encrypt;
1263 
1264 	/* A combination key has always sufficient security for the security
1265 	   levels 1 or 2. High security level requires the combination key
1266 	   is generated using maximum PIN code length (16).
1267 	   For pre 2.1 units. */
1268 	if (conn->key_type == HCI_LK_COMBINATION &&
1269 	    (sec_level == BT_SECURITY_MEDIUM || sec_level == BT_SECURITY_LOW ||
1270 	     conn->pin_length == 16))
1271 		goto encrypt;
1272 
1273 auth:
1274 	if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags))
1275 		return 0;
1276 
1277 	if (initiator)
1278 		set_bit(HCI_CONN_AUTH_INITIATOR, &conn->flags);
1279 
1280 	if (!hci_conn_auth(conn, sec_level, auth_type))
1281 		return 0;
1282 
1283 encrypt:
1284 	if (test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1285 		return 1;
1286 
1287 	hci_conn_encrypt(conn);
1288 	return 0;
1289 }
1290 EXPORT_SYMBOL(hci_conn_security);
1291 
1292 /* Check secure link requirement */
1293 int hci_conn_check_secure(struct hci_conn *conn, __u8 sec_level)
1294 {
1295 	BT_DBG("hcon %p", conn);
1296 
1297 	/* Accept if non-secure or higher security level is required */
1298 	if (sec_level != BT_SECURITY_HIGH && sec_level != BT_SECURITY_FIPS)
1299 		return 1;
1300 
1301 	/* Accept if secure or higher security level is already present */
1302 	if (conn->sec_level == BT_SECURITY_HIGH ||
1303 	    conn->sec_level == BT_SECURITY_FIPS)
1304 		return 1;
1305 
1306 	/* Reject not secure link */
1307 	return 0;
1308 }
1309 EXPORT_SYMBOL(hci_conn_check_secure);
1310 
1311 /* Switch role */
1312 int hci_conn_switch_role(struct hci_conn *conn, __u8 role)
1313 {
1314 	BT_DBG("hcon %p", conn);
1315 
1316 	if (role == conn->role)
1317 		return 1;
1318 
1319 	if (!test_and_set_bit(HCI_CONN_RSWITCH_PEND, &conn->flags)) {
1320 		struct hci_cp_switch_role cp;
1321 		bacpy(&cp.bdaddr, &conn->dst);
1322 		cp.role = role;
1323 		hci_send_cmd(conn->hdev, HCI_OP_SWITCH_ROLE, sizeof(cp), &cp);
1324 	}
1325 
1326 	return 0;
1327 }
1328 EXPORT_SYMBOL(hci_conn_switch_role);
1329 
1330 /* Enter active mode */
1331 void hci_conn_enter_active_mode(struct hci_conn *conn, __u8 force_active)
1332 {
1333 	struct hci_dev *hdev = conn->hdev;
1334 
1335 	BT_DBG("hcon %p mode %d", conn, conn->mode);
1336 
1337 	if (conn->mode != HCI_CM_SNIFF)
1338 		goto timer;
1339 
1340 	if (!test_bit(HCI_CONN_POWER_SAVE, &conn->flags) && !force_active)
1341 		goto timer;
1342 
1343 	if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->flags)) {
1344 		struct hci_cp_exit_sniff_mode cp;
1345 		cp.handle = cpu_to_le16(conn->handle);
1346 		hci_send_cmd(hdev, HCI_OP_EXIT_SNIFF_MODE, sizeof(cp), &cp);
1347 	}
1348 
1349 timer:
1350 	if (hdev->idle_timeout > 0)
1351 		queue_delayed_work(hdev->workqueue, &conn->idle_work,
1352 				   msecs_to_jiffies(hdev->idle_timeout));
1353 }
1354 
1355 /* Drop all connection on the device */
1356 void hci_conn_hash_flush(struct hci_dev *hdev)
1357 {
1358 	struct hci_conn_hash *h = &hdev->conn_hash;
1359 	struct hci_conn *c, *n;
1360 
1361 	BT_DBG("hdev %s", hdev->name);
1362 
1363 	list_for_each_entry_safe(c, n, &h->list, list) {
1364 		c->state = BT_CLOSED;
1365 
1366 		hci_disconn_cfm(c, HCI_ERROR_LOCAL_HOST_TERM);
1367 		hci_conn_del(c);
1368 	}
1369 }
1370 
1371 /* Check pending connect attempts */
1372 void hci_conn_check_pending(struct hci_dev *hdev)
1373 {
1374 	struct hci_conn *conn;
1375 
1376 	BT_DBG("hdev %s", hdev->name);
1377 
1378 	hci_dev_lock(hdev);
1379 
1380 	conn = hci_conn_hash_lookup_state(hdev, ACL_LINK, BT_CONNECT2);
1381 	if (conn)
1382 		hci_acl_create_connection(conn);
1383 
1384 	hci_dev_unlock(hdev);
1385 }
1386 
1387 static u32 get_link_mode(struct hci_conn *conn)
1388 {
1389 	u32 link_mode = 0;
1390 
1391 	if (conn->role == HCI_ROLE_MASTER)
1392 		link_mode |= HCI_LM_MASTER;
1393 
1394 	if (test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1395 		link_mode |= HCI_LM_ENCRYPT;
1396 
1397 	if (test_bit(HCI_CONN_AUTH, &conn->flags))
1398 		link_mode |= HCI_LM_AUTH;
1399 
1400 	if (test_bit(HCI_CONN_SECURE, &conn->flags))
1401 		link_mode |= HCI_LM_SECURE;
1402 
1403 	if (test_bit(HCI_CONN_FIPS, &conn->flags))
1404 		link_mode |= HCI_LM_FIPS;
1405 
1406 	return link_mode;
1407 }
1408 
1409 int hci_get_conn_list(void __user *arg)
1410 {
1411 	struct hci_conn *c;
1412 	struct hci_conn_list_req req, *cl;
1413 	struct hci_conn_info *ci;
1414 	struct hci_dev *hdev;
1415 	int n = 0, size, err;
1416 
1417 	if (copy_from_user(&req, arg, sizeof(req)))
1418 		return -EFAULT;
1419 
1420 	if (!req.conn_num || req.conn_num > (PAGE_SIZE * 2) / sizeof(*ci))
1421 		return -EINVAL;
1422 
1423 	size = sizeof(req) + req.conn_num * sizeof(*ci);
1424 
1425 	cl = kmalloc(size, GFP_KERNEL);
1426 	if (!cl)
1427 		return -ENOMEM;
1428 
1429 	hdev = hci_dev_get(req.dev_id);
1430 	if (!hdev) {
1431 		kfree(cl);
1432 		return -ENODEV;
1433 	}
1434 
1435 	ci = cl->conn_info;
1436 
1437 	hci_dev_lock(hdev);
1438 	list_for_each_entry(c, &hdev->conn_hash.list, list) {
1439 		bacpy(&(ci + n)->bdaddr, &c->dst);
1440 		(ci + n)->handle = c->handle;
1441 		(ci + n)->type  = c->type;
1442 		(ci + n)->out   = c->out;
1443 		(ci + n)->state = c->state;
1444 		(ci + n)->link_mode = get_link_mode(c);
1445 		if (++n >= req.conn_num)
1446 			break;
1447 	}
1448 	hci_dev_unlock(hdev);
1449 
1450 	cl->dev_id = hdev->id;
1451 	cl->conn_num = n;
1452 	size = sizeof(req) + n * sizeof(*ci);
1453 
1454 	hci_dev_put(hdev);
1455 
1456 	err = copy_to_user(arg, cl, size);
1457 	kfree(cl);
1458 
1459 	return err ? -EFAULT : 0;
1460 }
1461 
1462 int hci_get_conn_info(struct hci_dev *hdev, void __user *arg)
1463 {
1464 	struct hci_conn_info_req req;
1465 	struct hci_conn_info ci;
1466 	struct hci_conn *conn;
1467 	char __user *ptr = arg + sizeof(req);
1468 
1469 	if (copy_from_user(&req, arg, sizeof(req)))
1470 		return -EFAULT;
1471 
1472 	hci_dev_lock(hdev);
1473 	conn = hci_conn_hash_lookup_ba(hdev, req.type, &req.bdaddr);
1474 	if (conn) {
1475 		bacpy(&ci.bdaddr, &conn->dst);
1476 		ci.handle = conn->handle;
1477 		ci.type  = conn->type;
1478 		ci.out   = conn->out;
1479 		ci.state = conn->state;
1480 		ci.link_mode = get_link_mode(conn);
1481 	}
1482 	hci_dev_unlock(hdev);
1483 
1484 	if (!conn)
1485 		return -ENOENT;
1486 
1487 	return copy_to_user(ptr, &ci, sizeof(ci)) ? -EFAULT : 0;
1488 }
1489 
1490 int hci_get_auth_info(struct hci_dev *hdev, void __user *arg)
1491 {
1492 	struct hci_auth_info_req req;
1493 	struct hci_conn *conn;
1494 
1495 	if (copy_from_user(&req, arg, sizeof(req)))
1496 		return -EFAULT;
1497 
1498 	hci_dev_lock(hdev);
1499 	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &req.bdaddr);
1500 	if (conn)
1501 		req.type = conn->auth_type;
1502 	hci_dev_unlock(hdev);
1503 
1504 	if (!conn)
1505 		return -ENOENT;
1506 
1507 	return copy_to_user(arg, &req, sizeof(req)) ? -EFAULT : 0;
1508 }
1509 
1510 struct hci_chan *hci_chan_create(struct hci_conn *conn)
1511 {
1512 	struct hci_dev *hdev = conn->hdev;
1513 	struct hci_chan *chan;
1514 
1515 	BT_DBG("%s hcon %p", hdev->name, conn);
1516 
1517 	if (test_bit(HCI_CONN_DROP, &conn->flags)) {
1518 		BT_DBG("Refusing to create new hci_chan");
1519 		return NULL;
1520 	}
1521 
1522 	chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1523 	if (!chan)
1524 		return NULL;
1525 
1526 	chan->conn = hci_conn_get(conn);
1527 	skb_queue_head_init(&chan->data_q);
1528 	chan->state = BT_CONNECTED;
1529 
1530 	list_add_rcu(&chan->list, &conn->chan_list);
1531 
1532 	return chan;
1533 }
1534 
1535 void hci_chan_del(struct hci_chan *chan)
1536 {
1537 	struct hci_conn *conn = chan->conn;
1538 	struct hci_dev *hdev = conn->hdev;
1539 
1540 	BT_DBG("%s hcon %p chan %p", hdev->name, conn, chan);
1541 
1542 	list_del_rcu(&chan->list);
1543 
1544 	synchronize_rcu();
1545 
1546 	/* Prevent new hci_chan's to be created for this hci_conn */
1547 	set_bit(HCI_CONN_DROP, &conn->flags);
1548 
1549 	hci_conn_put(conn);
1550 
1551 	skb_queue_purge(&chan->data_q);
1552 	kfree(chan);
1553 }
1554 
1555 void hci_chan_list_flush(struct hci_conn *conn)
1556 {
1557 	struct hci_chan *chan, *n;
1558 
1559 	BT_DBG("hcon %p", conn);
1560 
1561 	list_for_each_entry_safe(chan, n, &conn->chan_list, list)
1562 		hci_chan_del(chan);
1563 }
1564 
1565 static struct hci_chan *__hci_chan_lookup_handle(struct hci_conn *hcon,
1566 						 __u16 handle)
1567 {
1568 	struct hci_chan *hchan;
1569 
1570 	list_for_each_entry(hchan, &hcon->chan_list, list) {
1571 		if (hchan->handle == handle)
1572 			return hchan;
1573 	}
1574 
1575 	return NULL;
1576 }
1577 
1578 struct hci_chan *hci_chan_lookup_handle(struct hci_dev *hdev, __u16 handle)
1579 {
1580 	struct hci_conn_hash *h = &hdev->conn_hash;
1581 	struct hci_conn *hcon;
1582 	struct hci_chan *hchan = NULL;
1583 
1584 	rcu_read_lock();
1585 
1586 	list_for_each_entry_rcu(hcon, &h->list, list) {
1587 		hchan = __hci_chan_lookup_handle(hcon, handle);
1588 		if (hchan)
1589 			break;
1590 	}
1591 
1592 	rcu_read_unlock();
1593 
1594 	return hchan;
1595 }
1596