xref: /openbmc/linux/net/bluetooth/hci_conn.c (revision 3949aaa6)
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_passive_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 (conn->type == SCO_LINK || conn->type == ESCO_LINK) {
126 		switch (conn->setting & SCO_AIRMODE_MASK) {
127 		case SCO_AIRMODE_CVSD:
128 		case SCO_AIRMODE_TRANSP:
129 			if (hdev->notify)
130 				hdev->notify(hdev, HCI_NOTIFY_DISABLE_SCO);
131 			break;
132 		}
133 	} else {
134 		if (hdev->notify)
135 			hdev->notify(hdev, HCI_NOTIFY_CONN_DEL);
136 	}
137 
138 	hci_conn_del_sysfs(conn);
139 
140 	debugfs_remove_recursive(conn->debugfs);
141 
142 	hci_dev_put(hdev);
143 
144 	hci_conn_put(conn);
145 }
146 
147 static void le_scan_cleanup(struct work_struct *work)
148 {
149 	struct hci_conn *conn = container_of(work, struct hci_conn,
150 					     le_scan_cleanup);
151 	struct hci_dev *hdev = conn->hdev;
152 	struct hci_conn *c = NULL;
153 
154 	BT_DBG("%s hcon %p", hdev->name, conn);
155 
156 	hci_dev_lock(hdev);
157 
158 	/* Check that the hci_conn is still around */
159 	rcu_read_lock();
160 	list_for_each_entry_rcu(c, &hdev->conn_hash.list, list) {
161 		if (c == conn)
162 			break;
163 	}
164 	rcu_read_unlock();
165 
166 	if (c == conn) {
167 		hci_connect_le_scan_cleanup(conn);
168 		hci_conn_cleanup(conn);
169 	}
170 
171 	hci_dev_unlock(hdev);
172 	hci_dev_put(hdev);
173 	hci_conn_put(conn);
174 }
175 
176 static void hci_connect_le_scan_remove(struct hci_conn *conn)
177 {
178 	BT_DBG("%s hcon %p", conn->hdev->name, conn);
179 
180 	/* We can't call hci_conn_del/hci_conn_cleanup here since that
181 	 * could deadlock with another hci_conn_del() call that's holding
182 	 * hci_dev_lock and doing cancel_delayed_work_sync(&conn->disc_work).
183 	 * Instead, grab temporary extra references to the hci_dev and
184 	 * hci_conn and perform the necessary cleanup in a separate work
185 	 * callback.
186 	 */
187 
188 	hci_dev_hold(conn->hdev);
189 	hci_conn_get(conn);
190 
191 	/* Even though we hold a reference to the hdev, many other
192 	 * things might get cleaned up meanwhile, including the hdev's
193 	 * own workqueue, so we can't use that for scheduling.
194 	 */
195 	schedule_work(&conn->le_scan_cleanup);
196 }
197 
198 static void hci_acl_create_connection(struct hci_conn *conn)
199 {
200 	struct hci_dev *hdev = conn->hdev;
201 	struct inquiry_entry *ie;
202 	struct hci_cp_create_conn cp;
203 
204 	BT_DBG("hcon %p", conn);
205 
206 	/* Many controllers disallow HCI Create Connection while it is doing
207 	 * HCI Inquiry. So we cancel the Inquiry first before issuing HCI Create
208 	 * Connection. This may cause the MGMT discovering state to become false
209 	 * without user space's request but it is okay since the MGMT Discovery
210 	 * APIs do not promise that discovery should be done forever. Instead,
211 	 * the user space monitors the status of MGMT discovering and it may
212 	 * request for discovery again when this flag becomes false.
213 	 */
214 	if (test_bit(HCI_INQUIRY, &hdev->flags)) {
215 		/* Put this connection to "pending" state so that it will be
216 		 * executed after the inquiry cancel command complete event.
217 		 */
218 		conn->state = BT_CONNECT2;
219 		hci_send_cmd(hdev, HCI_OP_INQUIRY_CANCEL, 0, NULL);
220 		return;
221 	}
222 
223 	conn->state = BT_CONNECT;
224 	conn->out = true;
225 	conn->role = HCI_ROLE_MASTER;
226 
227 	conn->attempt++;
228 
229 	conn->link_policy = hdev->link_policy;
230 
231 	memset(&cp, 0, sizeof(cp));
232 	bacpy(&cp.bdaddr, &conn->dst);
233 	cp.pscan_rep_mode = 0x02;
234 
235 	ie = hci_inquiry_cache_lookup(hdev, &conn->dst);
236 	if (ie) {
237 		if (inquiry_entry_age(ie) <= INQUIRY_ENTRY_AGE_MAX) {
238 			cp.pscan_rep_mode = ie->data.pscan_rep_mode;
239 			cp.pscan_mode     = ie->data.pscan_mode;
240 			cp.clock_offset   = ie->data.clock_offset |
241 					    cpu_to_le16(0x8000);
242 		}
243 
244 		memcpy(conn->dev_class, ie->data.dev_class, 3);
245 	}
246 
247 	cp.pkt_type = cpu_to_le16(conn->pkt_type);
248 	if (lmp_rswitch_capable(hdev) && !(hdev->link_mode & HCI_LM_MASTER))
249 		cp.role_switch = 0x01;
250 	else
251 		cp.role_switch = 0x00;
252 
253 	hci_send_cmd(hdev, HCI_OP_CREATE_CONN, sizeof(cp), &cp);
254 }
255 
256 int hci_disconnect(struct hci_conn *conn, __u8 reason)
257 {
258 	BT_DBG("hcon %p", conn);
259 
260 	/* When we are central of an established connection and it enters
261 	 * the disconnect timeout, then go ahead and try to read the
262 	 * current clock offset.  Processing of the result is done
263 	 * within the event handling and hci_clock_offset_evt function.
264 	 */
265 	if (conn->type == ACL_LINK && conn->role == HCI_ROLE_MASTER &&
266 	    (conn->state == BT_CONNECTED || conn->state == BT_CONFIG)) {
267 		struct hci_dev *hdev = conn->hdev;
268 		struct hci_cp_read_clock_offset clkoff_cp;
269 
270 		clkoff_cp.handle = cpu_to_le16(conn->handle);
271 		hci_send_cmd(hdev, HCI_OP_READ_CLOCK_OFFSET, sizeof(clkoff_cp),
272 			     &clkoff_cp);
273 	}
274 
275 	return hci_abort_conn(conn, reason);
276 }
277 
278 static void hci_add_sco(struct hci_conn *conn, __u16 handle)
279 {
280 	struct hci_dev *hdev = conn->hdev;
281 	struct hci_cp_add_sco cp;
282 
283 	BT_DBG("hcon %p", conn);
284 
285 	conn->state = BT_CONNECT;
286 	conn->out = true;
287 
288 	conn->attempt++;
289 
290 	cp.handle   = cpu_to_le16(handle);
291 	cp.pkt_type = cpu_to_le16(conn->pkt_type);
292 
293 	hci_send_cmd(hdev, HCI_OP_ADD_SCO, sizeof(cp), &cp);
294 }
295 
296 static bool find_next_esco_param(struct hci_conn *conn,
297 				 const struct sco_param *esco_param, int size)
298 {
299 	for (; conn->attempt <= size; conn->attempt++) {
300 		if (lmp_esco_2m_capable(conn->link) ||
301 		    (esco_param[conn->attempt - 1].pkt_type & ESCO_2EV3))
302 			break;
303 		BT_DBG("hcon %p skipped attempt %d, eSCO 2M not supported",
304 		       conn, conn->attempt);
305 	}
306 
307 	return conn->attempt <= size;
308 }
309 
310 static bool hci_enhanced_setup_sync_conn(struct hci_conn *conn, __u16 handle)
311 {
312 	struct hci_dev *hdev = conn->hdev;
313 	struct hci_cp_enhanced_setup_sync_conn cp;
314 	const struct sco_param *param;
315 
316 	bt_dev_dbg(hdev, "hcon %p", conn);
317 
318 	/* for offload use case, codec needs to configured before opening SCO */
319 	if (conn->codec.data_path)
320 		hci_req_configure_datapath(hdev, &conn->codec);
321 
322 	conn->state = BT_CONNECT;
323 	conn->out = true;
324 
325 	conn->attempt++;
326 
327 	memset(&cp, 0x00, sizeof(cp));
328 
329 	cp.handle   = cpu_to_le16(handle);
330 
331 	cp.tx_bandwidth   = cpu_to_le32(0x00001f40);
332 	cp.rx_bandwidth   = cpu_to_le32(0x00001f40);
333 
334 	switch (conn->codec.id) {
335 	case BT_CODEC_MSBC:
336 		if (!find_next_esco_param(conn, esco_param_msbc,
337 					  ARRAY_SIZE(esco_param_msbc)))
338 			return false;
339 
340 		param = &esco_param_msbc[conn->attempt - 1];
341 		cp.tx_coding_format.id = 0x05;
342 		cp.rx_coding_format.id = 0x05;
343 		cp.tx_codec_frame_size = __cpu_to_le16(60);
344 		cp.rx_codec_frame_size = __cpu_to_le16(60);
345 		cp.in_bandwidth = __cpu_to_le32(32000);
346 		cp.out_bandwidth = __cpu_to_le32(32000);
347 		cp.in_coding_format.id = 0x04;
348 		cp.out_coding_format.id = 0x04;
349 		cp.in_coded_data_size = __cpu_to_le16(16);
350 		cp.out_coded_data_size = __cpu_to_le16(16);
351 		cp.in_pcm_data_format = 2;
352 		cp.out_pcm_data_format = 2;
353 		cp.in_pcm_sample_payload_msb_pos = 0;
354 		cp.out_pcm_sample_payload_msb_pos = 0;
355 		cp.in_data_path = conn->codec.data_path;
356 		cp.out_data_path = conn->codec.data_path;
357 		cp.in_transport_unit_size = 1;
358 		cp.out_transport_unit_size = 1;
359 		break;
360 
361 	case BT_CODEC_TRANSPARENT:
362 		if (!find_next_esco_param(conn, esco_param_msbc,
363 					  ARRAY_SIZE(esco_param_msbc)))
364 			return false;
365 		param = &esco_param_msbc[conn->attempt - 1];
366 		cp.tx_coding_format.id = 0x03;
367 		cp.rx_coding_format.id = 0x03;
368 		cp.tx_codec_frame_size = __cpu_to_le16(60);
369 		cp.rx_codec_frame_size = __cpu_to_le16(60);
370 		cp.in_bandwidth = __cpu_to_le32(0x1f40);
371 		cp.out_bandwidth = __cpu_to_le32(0x1f40);
372 		cp.in_coding_format.id = 0x03;
373 		cp.out_coding_format.id = 0x03;
374 		cp.in_coded_data_size = __cpu_to_le16(16);
375 		cp.out_coded_data_size = __cpu_to_le16(16);
376 		cp.in_pcm_data_format = 2;
377 		cp.out_pcm_data_format = 2;
378 		cp.in_pcm_sample_payload_msb_pos = 0;
379 		cp.out_pcm_sample_payload_msb_pos = 0;
380 		cp.in_data_path = conn->codec.data_path;
381 		cp.out_data_path = conn->codec.data_path;
382 		cp.in_transport_unit_size = 1;
383 		cp.out_transport_unit_size = 1;
384 		break;
385 
386 	case BT_CODEC_CVSD:
387 		if (lmp_esco_capable(conn->link)) {
388 			if (!find_next_esco_param(conn, esco_param_cvsd,
389 						  ARRAY_SIZE(esco_param_cvsd)))
390 				return false;
391 			param = &esco_param_cvsd[conn->attempt - 1];
392 		} else {
393 			if (conn->attempt > ARRAY_SIZE(sco_param_cvsd))
394 				return false;
395 			param = &sco_param_cvsd[conn->attempt - 1];
396 		}
397 		cp.tx_coding_format.id = 2;
398 		cp.rx_coding_format.id = 2;
399 		cp.tx_codec_frame_size = __cpu_to_le16(60);
400 		cp.rx_codec_frame_size = __cpu_to_le16(60);
401 		cp.in_bandwidth = __cpu_to_le32(16000);
402 		cp.out_bandwidth = __cpu_to_le32(16000);
403 		cp.in_coding_format.id = 4;
404 		cp.out_coding_format.id = 4;
405 		cp.in_coded_data_size = __cpu_to_le16(16);
406 		cp.out_coded_data_size = __cpu_to_le16(16);
407 		cp.in_pcm_data_format = 2;
408 		cp.out_pcm_data_format = 2;
409 		cp.in_pcm_sample_payload_msb_pos = 0;
410 		cp.out_pcm_sample_payload_msb_pos = 0;
411 		cp.in_data_path = conn->codec.data_path;
412 		cp.out_data_path = conn->codec.data_path;
413 		cp.in_transport_unit_size = 16;
414 		cp.out_transport_unit_size = 16;
415 		break;
416 	default:
417 		return false;
418 	}
419 
420 	cp.retrans_effort = param->retrans_effort;
421 	cp.pkt_type = __cpu_to_le16(param->pkt_type);
422 	cp.max_latency = __cpu_to_le16(param->max_latency);
423 
424 	if (hci_send_cmd(hdev, HCI_OP_ENHANCED_SETUP_SYNC_CONN, sizeof(cp), &cp) < 0)
425 		return false;
426 
427 	return true;
428 }
429 
430 static bool hci_setup_sync_conn(struct hci_conn *conn, __u16 handle)
431 {
432 	struct hci_dev *hdev = conn->hdev;
433 	struct hci_cp_setup_sync_conn cp;
434 	const struct sco_param *param;
435 
436 	bt_dev_dbg(hdev, "hcon %p", conn);
437 
438 	conn->state = BT_CONNECT;
439 	conn->out = true;
440 
441 	conn->attempt++;
442 
443 	cp.handle   = cpu_to_le16(handle);
444 
445 	cp.tx_bandwidth   = cpu_to_le32(0x00001f40);
446 	cp.rx_bandwidth   = cpu_to_le32(0x00001f40);
447 	cp.voice_setting  = cpu_to_le16(conn->setting);
448 
449 	switch (conn->setting & SCO_AIRMODE_MASK) {
450 	case SCO_AIRMODE_TRANSP:
451 		if (!find_next_esco_param(conn, esco_param_msbc,
452 					  ARRAY_SIZE(esco_param_msbc)))
453 			return false;
454 		param = &esco_param_msbc[conn->attempt - 1];
455 		break;
456 	case SCO_AIRMODE_CVSD:
457 		if (lmp_esco_capable(conn->link)) {
458 			if (!find_next_esco_param(conn, esco_param_cvsd,
459 						  ARRAY_SIZE(esco_param_cvsd)))
460 				return false;
461 			param = &esco_param_cvsd[conn->attempt - 1];
462 		} else {
463 			if (conn->attempt > ARRAY_SIZE(sco_param_cvsd))
464 				return false;
465 			param = &sco_param_cvsd[conn->attempt - 1];
466 		}
467 		break;
468 	default:
469 		return false;
470 	}
471 
472 	cp.retrans_effort = param->retrans_effort;
473 	cp.pkt_type = __cpu_to_le16(param->pkt_type);
474 	cp.max_latency = __cpu_to_le16(param->max_latency);
475 
476 	if (hci_send_cmd(hdev, HCI_OP_SETUP_SYNC_CONN, sizeof(cp), &cp) < 0)
477 		return false;
478 
479 	return true;
480 }
481 
482 bool hci_setup_sync(struct hci_conn *conn, __u16 handle)
483 {
484 	if (enhanced_sco_capable(conn->hdev))
485 		return hci_enhanced_setup_sync_conn(conn, handle);
486 
487 	return hci_setup_sync_conn(conn, handle);
488 }
489 
490 u8 hci_le_conn_update(struct hci_conn *conn, u16 min, u16 max, u16 latency,
491 		      u16 to_multiplier)
492 {
493 	struct hci_dev *hdev = conn->hdev;
494 	struct hci_conn_params *params;
495 	struct hci_cp_le_conn_update cp;
496 
497 	hci_dev_lock(hdev);
498 
499 	params = hci_conn_params_lookup(hdev, &conn->dst, conn->dst_type);
500 	if (params) {
501 		params->conn_min_interval = min;
502 		params->conn_max_interval = max;
503 		params->conn_latency = latency;
504 		params->supervision_timeout = to_multiplier;
505 	}
506 
507 	hci_dev_unlock(hdev);
508 
509 	memset(&cp, 0, sizeof(cp));
510 	cp.handle		= cpu_to_le16(conn->handle);
511 	cp.conn_interval_min	= cpu_to_le16(min);
512 	cp.conn_interval_max	= cpu_to_le16(max);
513 	cp.conn_latency		= cpu_to_le16(latency);
514 	cp.supervision_timeout	= cpu_to_le16(to_multiplier);
515 	cp.min_ce_len		= cpu_to_le16(0x0000);
516 	cp.max_ce_len		= cpu_to_le16(0x0000);
517 
518 	hci_send_cmd(hdev, HCI_OP_LE_CONN_UPDATE, sizeof(cp), &cp);
519 
520 	if (params)
521 		return 0x01;
522 
523 	return 0x00;
524 }
525 
526 void hci_le_start_enc(struct hci_conn *conn, __le16 ediv, __le64 rand,
527 		      __u8 ltk[16], __u8 key_size)
528 {
529 	struct hci_dev *hdev = conn->hdev;
530 	struct hci_cp_le_start_enc cp;
531 
532 	BT_DBG("hcon %p", conn);
533 
534 	memset(&cp, 0, sizeof(cp));
535 
536 	cp.handle = cpu_to_le16(conn->handle);
537 	cp.rand = rand;
538 	cp.ediv = ediv;
539 	memcpy(cp.ltk, ltk, key_size);
540 
541 	hci_send_cmd(hdev, HCI_OP_LE_START_ENC, sizeof(cp), &cp);
542 }
543 
544 /* Device _must_ be locked */
545 void hci_sco_setup(struct hci_conn *conn, __u8 status)
546 {
547 	struct hci_conn *sco = conn->link;
548 
549 	if (!sco)
550 		return;
551 
552 	BT_DBG("hcon %p", conn);
553 
554 	if (!status) {
555 		if (lmp_esco_capable(conn->hdev))
556 			hci_setup_sync(sco, conn->handle);
557 		else
558 			hci_add_sco(sco, conn->handle);
559 	} else {
560 		hci_connect_cfm(sco, status);
561 		hci_conn_del(sco);
562 	}
563 }
564 
565 static void hci_conn_timeout(struct work_struct *work)
566 {
567 	struct hci_conn *conn = container_of(work, struct hci_conn,
568 					     disc_work.work);
569 	int refcnt = atomic_read(&conn->refcnt);
570 
571 	BT_DBG("hcon %p state %s", conn, state_to_string(conn->state));
572 
573 	WARN_ON(refcnt < 0);
574 
575 	/* FIXME: It was observed that in pairing failed scenario, refcnt
576 	 * drops below 0. Probably this is because l2cap_conn_del calls
577 	 * l2cap_chan_del for each channel, and inside l2cap_chan_del conn is
578 	 * dropped. After that loop hci_chan_del is called which also drops
579 	 * conn. For now make sure that ACL is alive if refcnt is higher then 0,
580 	 * otherwise drop it.
581 	 */
582 	if (refcnt > 0)
583 		return;
584 
585 	/* LE connections in scanning state need special handling */
586 	if (conn->state == BT_CONNECT && conn->type == LE_LINK &&
587 	    test_bit(HCI_CONN_SCANNING, &conn->flags)) {
588 		hci_connect_le_scan_remove(conn);
589 		return;
590 	}
591 
592 	hci_abort_conn(conn, hci_proto_disconn_ind(conn));
593 }
594 
595 /* Enter sniff mode */
596 static void hci_conn_idle(struct work_struct *work)
597 {
598 	struct hci_conn *conn = container_of(work, struct hci_conn,
599 					     idle_work.work);
600 	struct hci_dev *hdev = conn->hdev;
601 
602 	BT_DBG("hcon %p mode %d", conn, conn->mode);
603 
604 	if (!lmp_sniff_capable(hdev) || !lmp_sniff_capable(conn))
605 		return;
606 
607 	if (conn->mode != HCI_CM_ACTIVE || !(conn->link_policy & HCI_LP_SNIFF))
608 		return;
609 
610 	if (lmp_sniffsubr_capable(hdev) && lmp_sniffsubr_capable(conn)) {
611 		struct hci_cp_sniff_subrate cp;
612 		cp.handle             = cpu_to_le16(conn->handle);
613 		cp.max_latency        = cpu_to_le16(0);
614 		cp.min_remote_timeout = cpu_to_le16(0);
615 		cp.min_local_timeout  = cpu_to_le16(0);
616 		hci_send_cmd(hdev, HCI_OP_SNIFF_SUBRATE, sizeof(cp), &cp);
617 	}
618 
619 	if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->flags)) {
620 		struct hci_cp_sniff_mode cp;
621 		cp.handle       = cpu_to_le16(conn->handle);
622 		cp.max_interval = cpu_to_le16(hdev->sniff_max_interval);
623 		cp.min_interval = cpu_to_le16(hdev->sniff_min_interval);
624 		cp.attempt      = cpu_to_le16(4);
625 		cp.timeout      = cpu_to_le16(1);
626 		hci_send_cmd(hdev, HCI_OP_SNIFF_MODE, sizeof(cp), &cp);
627 	}
628 }
629 
630 static void hci_conn_auto_accept(struct work_struct *work)
631 {
632 	struct hci_conn *conn = container_of(work, struct hci_conn,
633 					     auto_accept_work.work);
634 
635 	hci_send_cmd(conn->hdev, HCI_OP_USER_CONFIRM_REPLY, sizeof(conn->dst),
636 		     &conn->dst);
637 }
638 
639 static void le_disable_advertising(struct hci_dev *hdev)
640 {
641 	if (ext_adv_capable(hdev)) {
642 		struct hci_cp_le_set_ext_adv_enable cp;
643 
644 		cp.enable = 0x00;
645 		cp.num_of_sets = 0x00;
646 
647 		hci_send_cmd(hdev, HCI_OP_LE_SET_EXT_ADV_ENABLE, sizeof(cp),
648 			     &cp);
649 	} else {
650 		u8 enable = 0x00;
651 		hci_send_cmd(hdev, HCI_OP_LE_SET_ADV_ENABLE, sizeof(enable),
652 			     &enable);
653 	}
654 }
655 
656 static void le_conn_timeout(struct work_struct *work)
657 {
658 	struct hci_conn *conn = container_of(work, struct hci_conn,
659 					     le_conn_timeout.work);
660 	struct hci_dev *hdev = conn->hdev;
661 
662 	BT_DBG("");
663 
664 	/* We could end up here due to having done directed advertising,
665 	 * so clean up the state if necessary. This should however only
666 	 * happen with broken hardware or if low duty cycle was used
667 	 * (which doesn't have a timeout of its own).
668 	 */
669 	if (conn->role == HCI_ROLE_SLAVE) {
670 		/* Disable LE Advertising */
671 		le_disable_advertising(hdev);
672 		hci_dev_lock(hdev);
673 		hci_le_conn_failed(conn, HCI_ERROR_ADVERTISING_TIMEOUT);
674 		hci_dev_unlock(hdev);
675 		return;
676 	}
677 
678 	hci_abort_conn(conn, HCI_ERROR_REMOTE_USER_TERM);
679 }
680 
681 struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
682 			      u8 role)
683 {
684 	struct hci_conn *conn;
685 
686 	BT_DBG("%s dst %pMR", hdev->name, dst);
687 
688 	conn = kzalloc(sizeof(*conn), GFP_KERNEL);
689 	if (!conn)
690 		return NULL;
691 
692 	bacpy(&conn->dst, dst);
693 	bacpy(&conn->src, &hdev->bdaddr);
694 	conn->handle = HCI_CONN_HANDLE_UNSET;
695 	conn->hdev  = hdev;
696 	conn->type  = type;
697 	conn->role  = role;
698 	conn->mode  = HCI_CM_ACTIVE;
699 	conn->state = BT_OPEN;
700 	conn->auth_type = HCI_AT_GENERAL_BONDING;
701 	conn->io_capability = hdev->io_capability;
702 	conn->remote_auth = 0xff;
703 	conn->key_type = 0xff;
704 	conn->rssi = HCI_RSSI_INVALID;
705 	conn->tx_power = HCI_TX_POWER_INVALID;
706 	conn->max_tx_power = HCI_TX_POWER_INVALID;
707 
708 	set_bit(HCI_CONN_POWER_SAVE, &conn->flags);
709 	conn->disc_timeout = HCI_DISCONN_TIMEOUT;
710 
711 	/* Set Default Authenticated payload timeout to 30s */
712 	conn->auth_payload_timeout = DEFAULT_AUTH_PAYLOAD_TIMEOUT;
713 
714 	if (conn->role == HCI_ROLE_MASTER)
715 		conn->out = true;
716 
717 	switch (type) {
718 	case ACL_LINK:
719 		conn->pkt_type = hdev->pkt_type & ACL_PTYPE_MASK;
720 		break;
721 	case LE_LINK:
722 		/* conn->src should reflect the local identity address */
723 		hci_copy_identity_address(hdev, &conn->src, &conn->src_type);
724 		break;
725 	case SCO_LINK:
726 		if (lmp_esco_capable(hdev))
727 			conn->pkt_type = (hdev->esco_type & SCO_ESCO_MASK) |
728 					(hdev->esco_type & EDR_ESCO_MASK);
729 		else
730 			conn->pkt_type = hdev->pkt_type & SCO_PTYPE_MASK;
731 		break;
732 	case ESCO_LINK:
733 		conn->pkt_type = hdev->esco_type & ~EDR_ESCO_MASK;
734 		break;
735 	}
736 
737 	skb_queue_head_init(&conn->data_q);
738 
739 	INIT_LIST_HEAD(&conn->chan_list);
740 
741 	INIT_DELAYED_WORK(&conn->disc_work, hci_conn_timeout);
742 	INIT_DELAYED_WORK(&conn->auto_accept_work, hci_conn_auto_accept);
743 	INIT_DELAYED_WORK(&conn->idle_work, hci_conn_idle);
744 	INIT_DELAYED_WORK(&conn->le_conn_timeout, le_conn_timeout);
745 	INIT_WORK(&conn->le_scan_cleanup, le_scan_cleanup);
746 
747 	atomic_set(&conn->refcnt, 0);
748 
749 	hci_dev_hold(hdev);
750 
751 	hci_conn_hash_add(hdev, conn);
752 
753 	/* The SCO and eSCO connections will only be notified when their
754 	 * setup has been completed. This is different to ACL links which
755 	 * can be notified right away.
756 	 */
757 	if (conn->type != SCO_LINK && conn->type != ESCO_LINK) {
758 		if (hdev->notify)
759 			hdev->notify(hdev, HCI_NOTIFY_CONN_ADD);
760 	}
761 
762 	hci_conn_init_sysfs(conn);
763 
764 	return conn;
765 }
766 
767 int hci_conn_del(struct hci_conn *conn)
768 {
769 	struct hci_dev *hdev = conn->hdev;
770 
771 	BT_DBG("%s hcon %p handle %d", hdev->name, conn, conn->handle);
772 
773 	cancel_delayed_work_sync(&conn->disc_work);
774 	cancel_delayed_work_sync(&conn->auto_accept_work);
775 	cancel_delayed_work_sync(&conn->idle_work);
776 
777 	if (conn->type == ACL_LINK) {
778 		struct hci_conn *sco = conn->link;
779 		if (sco)
780 			sco->link = NULL;
781 
782 		/* Unacked frames */
783 		hdev->acl_cnt += conn->sent;
784 	} else if (conn->type == LE_LINK) {
785 		cancel_delayed_work(&conn->le_conn_timeout);
786 
787 		if (hdev->le_pkts)
788 			hdev->le_cnt += conn->sent;
789 		else
790 			hdev->acl_cnt += conn->sent;
791 	} else {
792 		struct hci_conn *acl = conn->link;
793 		if (acl) {
794 			acl->link = NULL;
795 			hci_conn_drop(acl);
796 		}
797 	}
798 
799 	if (conn->amp_mgr)
800 		amp_mgr_put(conn->amp_mgr);
801 
802 	skb_queue_purge(&conn->data_q);
803 
804 	/* Remove the connection from the list and cleanup its remaining
805 	 * state. This is a separate function since for some cases like
806 	 * BT_CONNECT_SCAN we *only* want the cleanup part without the
807 	 * rest of hci_conn_del.
808 	 */
809 	hci_conn_cleanup(conn);
810 
811 	return 0;
812 }
813 
814 struct hci_dev *hci_get_route(bdaddr_t *dst, bdaddr_t *src, uint8_t src_type)
815 {
816 	int use_src = bacmp(src, BDADDR_ANY);
817 	struct hci_dev *hdev = NULL, *d;
818 
819 	BT_DBG("%pMR -> %pMR", src, dst);
820 
821 	read_lock(&hci_dev_list_lock);
822 
823 	list_for_each_entry(d, &hci_dev_list, list) {
824 		if (!test_bit(HCI_UP, &d->flags) ||
825 		    hci_dev_test_flag(d, HCI_USER_CHANNEL) ||
826 		    d->dev_type != HCI_PRIMARY)
827 			continue;
828 
829 		/* Simple routing:
830 		 *   No source address - find interface with bdaddr != dst
831 		 *   Source address    - find interface with bdaddr == src
832 		 */
833 
834 		if (use_src) {
835 			bdaddr_t id_addr;
836 			u8 id_addr_type;
837 
838 			if (src_type == BDADDR_BREDR) {
839 				if (!lmp_bredr_capable(d))
840 					continue;
841 				bacpy(&id_addr, &d->bdaddr);
842 				id_addr_type = BDADDR_BREDR;
843 			} else {
844 				if (!lmp_le_capable(d))
845 					continue;
846 
847 				hci_copy_identity_address(d, &id_addr,
848 							  &id_addr_type);
849 
850 				/* Convert from HCI to three-value type */
851 				if (id_addr_type == ADDR_LE_DEV_PUBLIC)
852 					id_addr_type = BDADDR_LE_PUBLIC;
853 				else
854 					id_addr_type = BDADDR_LE_RANDOM;
855 			}
856 
857 			if (!bacmp(&id_addr, src) && id_addr_type == src_type) {
858 				hdev = d; break;
859 			}
860 		} else {
861 			if (bacmp(&d->bdaddr, dst)) {
862 				hdev = d; break;
863 			}
864 		}
865 	}
866 
867 	if (hdev)
868 		hdev = hci_dev_hold(hdev);
869 
870 	read_unlock(&hci_dev_list_lock);
871 	return hdev;
872 }
873 EXPORT_SYMBOL(hci_get_route);
874 
875 /* This function requires the caller holds hdev->lock */
876 void hci_le_conn_failed(struct hci_conn *conn, u8 status)
877 {
878 	struct hci_dev *hdev = conn->hdev;
879 	struct hci_conn_params *params;
880 
881 	params = hci_pend_le_action_lookup(&hdev->pend_le_conns, &conn->dst,
882 					   conn->dst_type);
883 	if (params && params->conn) {
884 		hci_conn_drop(params->conn);
885 		hci_conn_put(params->conn);
886 		params->conn = NULL;
887 	}
888 
889 	conn->state = BT_CLOSED;
890 
891 	/* If the status indicates successful cancellation of
892 	 * the attempt (i.e. Unknown Connection Id) there's no point of
893 	 * notifying failure since we'll go back to keep trying to
894 	 * connect. The only exception is explicit connect requests
895 	 * where a timeout + cancel does indicate an actual failure.
896 	 */
897 	if (status != HCI_ERROR_UNKNOWN_CONN_ID ||
898 	    (params && params->explicit_connect))
899 		mgmt_connect_failed(hdev, &conn->dst, conn->type,
900 				    conn->dst_type, status);
901 
902 	hci_connect_cfm(conn, status);
903 
904 	hci_conn_del(conn);
905 
906 	/* Since we may have temporarily stopped the background scanning in
907 	 * favor of connection establishment, we should restart it.
908 	 */
909 	hci_update_passive_scan(hdev);
910 
911 	/* Enable advertising in case this was a failed connection
912 	 * attempt as a peripheral.
913 	 */
914 	hci_enable_advertising(hdev);
915 }
916 
917 static void create_le_conn_complete(struct hci_dev *hdev, void *data, int err)
918 {
919 	struct hci_conn *conn = data;
920 
921 	hci_dev_lock(hdev);
922 
923 	if (!err) {
924 		hci_connect_le_scan_cleanup(conn);
925 		goto done;
926 	}
927 
928 	bt_dev_err(hdev, "request failed to create LE connection: err %d", err);
929 
930 	if (!conn)
931 		goto done;
932 
933 	hci_le_conn_failed(conn, err);
934 
935 done:
936 	hci_dev_unlock(hdev);
937 }
938 
939 static int hci_connect_le_sync(struct hci_dev *hdev, void *data)
940 {
941 	struct hci_conn *conn = data;
942 
943 	bt_dev_dbg(hdev, "conn %p", conn);
944 
945 	return hci_le_create_conn_sync(hdev, conn);
946 }
947 
948 struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
949 				u8 dst_type, bool dst_resolved, u8 sec_level,
950 				u16 conn_timeout, u8 role)
951 {
952 	struct hci_conn *conn;
953 	struct smp_irk *irk;
954 	int err;
955 
956 	/* Let's make sure that le is enabled.*/
957 	if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) {
958 		if (lmp_le_capable(hdev))
959 			return ERR_PTR(-ECONNREFUSED);
960 
961 		return ERR_PTR(-EOPNOTSUPP);
962 	}
963 
964 	/* Since the controller supports only one LE connection attempt at a
965 	 * time, we return -EBUSY if there is any connection attempt running.
966 	 */
967 	if (hci_lookup_le_connect(hdev))
968 		return ERR_PTR(-EBUSY);
969 
970 	/* If there's already a connection object but it's not in
971 	 * scanning state it means it must already be established, in
972 	 * which case we can't do anything else except report a failure
973 	 * to connect.
974 	 */
975 	conn = hci_conn_hash_lookup_le(hdev, dst, dst_type);
976 	if (conn && !test_bit(HCI_CONN_SCANNING, &conn->flags)) {
977 		return ERR_PTR(-EBUSY);
978 	}
979 
980 	/* Check if the destination address has been resolved by the controller
981 	 * since if it did then the identity address shall be used.
982 	 */
983 	if (!dst_resolved) {
984 		/* When given an identity address with existing identity
985 		 * resolving key, the connection needs to be established
986 		 * to a resolvable random address.
987 		 *
988 		 * Storing the resolvable random address is required here
989 		 * to handle connection failures. The address will later
990 		 * be resolved back into the original identity address
991 		 * from the connect request.
992 		 */
993 		irk = hci_find_irk_by_addr(hdev, dst, dst_type);
994 		if (irk && bacmp(&irk->rpa, BDADDR_ANY)) {
995 			dst = &irk->rpa;
996 			dst_type = ADDR_LE_DEV_RANDOM;
997 		}
998 	}
999 
1000 	if (conn) {
1001 		bacpy(&conn->dst, dst);
1002 	} else {
1003 		conn = hci_conn_add(hdev, LE_LINK, dst, role);
1004 		if (!conn)
1005 			return ERR_PTR(-ENOMEM);
1006 		hci_conn_hold(conn);
1007 		conn->pending_sec_level = sec_level;
1008 	}
1009 
1010 	conn->dst_type = dst_type;
1011 	conn->sec_level = BT_SECURITY_LOW;
1012 	conn->conn_timeout = conn_timeout;
1013 
1014 	conn->state = BT_CONNECT;
1015 	clear_bit(HCI_CONN_SCANNING, &conn->flags);
1016 
1017 	err = hci_cmd_sync_queue(hdev, hci_connect_le_sync, conn,
1018 				 create_le_conn_complete);
1019 	if (err) {
1020 		hci_conn_del(conn);
1021 		return ERR_PTR(err);
1022 	}
1023 
1024 	return conn;
1025 }
1026 
1027 static bool is_connected(struct hci_dev *hdev, bdaddr_t *addr, u8 type)
1028 {
1029 	struct hci_conn *conn;
1030 
1031 	conn = hci_conn_hash_lookup_le(hdev, addr, type);
1032 	if (!conn)
1033 		return false;
1034 
1035 	if (conn->state != BT_CONNECTED)
1036 		return false;
1037 
1038 	return true;
1039 }
1040 
1041 /* This function requires the caller holds hdev->lock */
1042 static int hci_explicit_conn_params_set(struct hci_dev *hdev,
1043 					bdaddr_t *addr, u8 addr_type)
1044 {
1045 	struct hci_conn_params *params;
1046 
1047 	if (is_connected(hdev, addr, addr_type))
1048 		return -EISCONN;
1049 
1050 	params = hci_conn_params_lookup(hdev, addr, addr_type);
1051 	if (!params) {
1052 		params = hci_conn_params_add(hdev, addr, addr_type);
1053 		if (!params)
1054 			return -ENOMEM;
1055 
1056 		/* If we created new params, mark them to be deleted in
1057 		 * hci_connect_le_scan_cleanup. It's different case than
1058 		 * existing disabled params, those will stay after cleanup.
1059 		 */
1060 		params->auto_connect = HCI_AUTO_CONN_EXPLICIT;
1061 	}
1062 
1063 	/* We're trying to connect, so make sure params are at pend_le_conns */
1064 	if (params->auto_connect == HCI_AUTO_CONN_DISABLED ||
1065 	    params->auto_connect == HCI_AUTO_CONN_REPORT ||
1066 	    params->auto_connect == HCI_AUTO_CONN_EXPLICIT) {
1067 		list_del_init(&params->action);
1068 		list_add(&params->action, &hdev->pend_le_conns);
1069 	}
1070 
1071 	params->explicit_connect = true;
1072 
1073 	BT_DBG("addr %pMR (type %u) auto_connect %u", addr, addr_type,
1074 	       params->auto_connect);
1075 
1076 	return 0;
1077 }
1078 
1079 /* This function requires the caller holds hdev->lock */
1080 struct hci_conn *hci_connect_le_scan(struct hci_dev *hdev, bdaddr_t *dst,
1081 				     u8 dst_type, u8 sec_level,
1082 				     u16 conn_timeout,
1083 				     enum conn_reasons conn_reason)
1084 {
1085 	struct hci_conn *conn;
1086 
1087 	/* Let's make sure that le is enabled.*/
1088 	if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) {
1089 		if (lmp_le_capable(hdev))
1090 			return ERR_PTR(-ECONNREFUSED);
1091 
1092 		return ERR_PTR(-EOPNOTSUPP);
1093 	}
1094 
1095 	/* Some devices send ATT messages as soon as the physical link is
1096 	 * established. To be able to handle these ATT messages, the user-
1097 	 * space first establishes the connection and then starts the pairing
1098 	 * process.
1099 	 *
1100 	 * So if a hci_conn object already exists for the following connection
1101 	 * attempt, we simply update pending_sec_level and auth_type fields
1102 	 * and return the object found.
1103 	 */
1104 	conn = hci_conn_hash_lookup_le(hdev, dst, dst_type);
1105 	if (conn) {
1106 		if (conn->pending_sec_level < sec_level)
1107 			conn->pending_sec_level = sec_level;
1108 		goto done;
1109 	}
1110 
1111 	BT_DBG("requesting refresh of dst_addr");
1112 
1113 	conn = hci_conn_add(hdev, LE_LINK, dst, HCI_ROLE_MASTER);
1114 	if (!conn)
1115 		return ERR_PTR(-ENOMEM);
1116 
1117 	if (hci_explicit_conn_params_set(hdev, dst, dst_type) < 0) {
1118 		hci_conn_del(conn);
1119 		return ERR_PTR(-EBUSY);
1120 	}
1121 
1122 	conn->state = BT_CONNECT;
1123 	set_bit(HCI_CONN_SCANNING, &conn->flags);
1124 	conn->dst_type = dst_type;
1125 	conn->sec_level = BT_SECURITY_LOW;
1126 	conn->pending_sec_level = sec_level;
1127 	conn->conn_timeout = conn_timeout;
1128 	conn->conn_reason = conn_reason;
1129 
1130 	hci_update_passive_scan(hdev);
1131 
1132 done:
1133 	hci_conn_hold(conn);
1134 	return conn;
1135 }
1136 
1137 struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
1138 				 u8 sec_level, u8 auth_type,
1139 				 enum conn_reasons conn_reason)
1140 {
1141 	struct hci_conn *acl;
1142 
1143 	if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED)) {
1144 		if (lmp_bredr_capable(hdev))
1145 			return ERR_PTR(-ECONNREFUSED);
1146 
1147 		return ERR_PTR(-EOPNOTSUPP);
1148 	}
1149 
1150 	acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
1151 	if (!acl) {
1152 		acl = hci_conn_add(hdev, ACL_LINK, dst, HCI_ROLE_MASTER);
1153 		if (!acl)
1154 			return ERR_PTR(-ENOMEM);
1155 	}
1156 
1157 	hci_conn_hold(acl);
1158 
1159 	acl->conn_reason = conn_reason;
1160 	if (acl->state == BT_OPEN || acl->state == BT_CLOSED) {
1161 		acl->sec_level = BT_SECURITY_LOW;
1162 		acl->pending_sec_level = sec_level;
1163 		acl->auth_type = auth_type;
1164 		hci_acl_create_connection(acl);
1165 	}
1166 
1167 	return acl;
1168 }
1169 
1170 struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type, bdaddr_t *dst,
1171 				 __u16 setting, struct bt_codec *codec)
1172 {
1173 	struct hci_conn *acl;
1174 	struct hci_conn *sco;
1175 
1176 	acl = hci_connect_acl(hdev, dst, BT_SECURITY_LOW, HCI_AT_NO_BONDING,
1177 			      CONN_REASON_SCO_CONNECT);
1178 	if (IS_ERR(acl))
1179 		return acl;
1180 
1181 	sco = hci_conn_hash_lookup_ba(hdev, type, dst);
1182 	if (!sco) {
1183 		sco = hci_conn_add(hdev, type, dst, HCI_ROLE_MASTER);
1184 		if (!sco) {
1185 			hci_conn_drop(acl);
1186 			return ERR_PTR(-ENOMEM);
1187 		}
1188 	}
1189 
1190 	acl->link = sco;
1191 	sco->link = acl;
1192 
1193 	hci_conn_hold(sco);
1194 
1195 	sco->setting = setting;
1196 	sco->codec = *codec;
1197 
1198 	if (acl->state == BT_CONNECTED &&
1199 	    (sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
1200 		set_bit(HCI_CONN_POWER_SAVE, &acl->flags);
1201 		hci_conn_enter_active_mode(acl, BT_POWER_FORCE_ACTIVE_ON);
1202 
1203 		if (test_bit(HCI_CONN_MODE_CHANGE_PEND, &acl->flags)) {
1204 			/* defer SCO setup until mode change completed */
1205 			set_bit(HCI_CONN_SCO_SETUP_PEND, &acl->flags);
1206 			return sco;
1207 		}
1208 
1209 		hci_sco_setup(acl, 0x00);
1210 	}
1211 
1212 	return sco;
1213 }
1214 
1215 /* Check link security requirement */
1216 int hci_conn_check_link_mode(struct hci_conn *conn)
1217 {
1218 	BT_DBG("hcon %p", conn);
1219 
1220 	/* In Secure Connections Only mode, it is required that Secure
1221 	 * Connections is used and the link is encrypted with AES-CCM
1222 	 * using a P-256 authenticated combination key.
1223 	 */
1224 	if (hci_dev_test_flag(conn->hdev, HCI_SC_ONLY)) {
1225 		if (!hci_conn_sc_enabled(conn) ||
1226 		    !test_bit(HCI_CONN_AES_CCM, &conn->flags) ||
1227 		    conn->key_type != HCI_LK_AUTH_COMBINATION_P256)
1228 			return 0;
1229 	}
1230 
1231 	 /* AES encryption is required for Level 4:
1232 	  *
1233 	  * BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 3, Part C
1234 	  * page 1319:
1235 	  *
1236 	  * 128-bit equivalent strength for link and encryption keys
1237 	  * required using FIPS approved algorithms (E0 not allowed,
1238 	  * SAFER+ not allowed, and P-192 not allowed; encryption key
1239 	  * not shortened)
1240 	  */
1241 	if (conn->sec_level == BT_SECURITY_FIPS &&
1242 	    !test_bit(HCI_CONN_AES_CCM, &conn->flags)) {
1243 		bt_dev_err(conn->hdev,
1244 			   "Invalid security: Missing AES-CCM usage");
1245 		return 0;
1246 	}
1247 
1248 	if (hci_conn_ssp_enabled(conn) &&
1249 	    !test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1250 		return 0;
1251 
1252 	return 1;
1253 }
1254 
1255 /* Authenticate remote device */
1256 static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
1257 {
1258 	BT_DBG("hcon %p", conn);
1259 
1260 	if (conn->pending_sec_level > sec_level)
1261 		sec_level = conn->pending_sec_level;
1262 
1263 	if (sec_level > conn->sec_level)
1264 		conn->pending_sec_level = sec_level;
1265 	else if (test_bit(HCI_CONN_AUTH, &conn->flags))
1266 		return 1;
1267 
1268 	/* Make sure we preserve an existing MITM requirement*/
1269 	auth_type |= (conn->auth_type & 0x01);
1270 
1271 	conn->auth_type = auth_type;
1272 
1273 	if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->flags)) {
1274 		struct hci_cp_auth_requested cp;
1275 
1276 		cp.handle = cpu_to_le16(conn->handle);
1277 		hci_send_cmd(conn->hdev, HCI_OP_AUTH_REQUESTED,
1278 			     sizeof(cp), &cp);
1279 
1280 		/* If we're already encrypted set the REAUTH_PEND flag,
1281 		 * otherwise set the ENCRYPT_PEND.
1282 		 */
1283 		if (test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1284 			set_bit(HCI_CONN_REAUTH_PEND, &conn->flags);
1285 		else
1286 			set_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags);
1287 	}
1288 
1289 	return 0;
1290 }
1291 
1292 /* Encrypt the link */
1293 static void hci_conn_encrypt(struct hci_conn *conn)
1294 {
1295 	BT_DBG("hcon %p", conn);
1296 
1297 	if (!test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags)) {
1298 		struct hci_cp_set_conn_encrypt cp;
1299 		cp.handle  = cpu_to_le16(conn->handle);
1300 		cp.encrypt = 0x01;
1301 		hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT, sizeof(cp),
1302 			     &cp);
1303 	}
1304 }
1305 
1306 /* Enable security */
1307 int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type,
1308 		      bool initiator)
1309 {
1310 	BT_DBG("hcon %p", conn);
1311 
1312 	if (conn->type == LE_LINK)
1313 		return smp_conn_security(conn, sec_level);
1314 
1315 	/* For sdp we don't need the link key. */
1316 	if (sec_level == BT_SECURITY_SDP)
1317 		return 1;
1318 
1319 	/* For non 2.1 devices and low security level we don't need the link
1320 	   key. */
1321 	if (sec_level == BT_SECURITY_LOW && !hci_conn_ssp_enabled(conn))
1322 		return 1;
1323 
1324 	/* For other security levels we need the link key. */
1325 	if (!test_bit(HCI_CONN_AUTH, &conn->flags))
1326 		goto auth;
1327 
1328 	/* An authenticated FIPS approved combination key has sufficient
1329 	 * security for security level 4. */
1330 	if (conn->key_type == HCI_LK_AUTH_COMBINATION_P256 &&
1331 	    sec_level == BT_SECURITY_FIPS)
1332 		goto encrypt;
1333 
1334 	/* An authenticated combination key has sufficient security for
1335 	   security level 3. */
1336 	if ((conn->key_type == HCI_LK_AUTH_COMBINATION_P192 ||
1337 	     conn->key_type == HCI_LK_AUTH_COMBINATION_P256) &&
1338 	    sec_level == BT_SECURITY_HIGH)
1339 		goto encrypt;
1340 
1341 	/* An unauthenticated combination key has sufficient security for
1342 	   security level 1 and 2. */
1343 	if ((conn->key_type == HCI_LK_UNAUTH_COMBINATION_P192 ||
1344 	     conn->key_type == HCI_LK_UNAUTH_COMBINATION_P256) &&
1345 	    (sec_level == BT_SECURITY_MEDIUM || sec_level == BT_SECURITY_LOW))
1346 		goto encrypt;
1347 
1348 	/* A combination key has always sufficient security for the security
1349 	   levels 1 or 2. High security level requires the combination key
1350 	   is generated using maximum PIN code length (16).
1351 	   For pre 2.1 units. */
1352 	if (conn->key_type == HCI_LK_COMBINATION &&
1353 	    (sec_level == BT_SECURITY_MEDIUM || sec_level == BT_SECURITY_LOW ||
1354 	     conn->pin_length == 16))
1355 		goto encrypt;
1356 
1357 auth:
1358 	if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags))
1359 		return 0;
1360 
1361 	if (initiator)
1362 		set_bit(HCI_CONN_AUTH_INITIATOR, &conn->flags);
1363 
1364 	if (!hci_conn_auth(conn, sec_level, auth_type))
1365 		return 0;
1366 
1367 encrypt:
1368 	if (test_bit(HCI_CONN_ENCRYPT, &conn->flags)) {
1369 		/* Ensure that the encryption key size has been read,
1370 		 * otherwise stall the upper layer responses.
1371 		 */
1372 		if (!conn->enc_key_size)
1373 			return 0;
1374 
1375 		/* Nothing else needed, all requirements are met */
1376 		return 1;
1377 	}
1378 
1379 	hci_conn_encrypt(conn);
1380 	return 0;
1381 }
1382 EXPORT_SYMBOL(hci_conn_security);
1383 
1384 /* Check secure link requirement */
1385 int hci_conn_check_secure(struct hci_conn *conn, __u8 sec_level)
1386 {
1387 	BT_DBG("hcon %p", conn);
1388 
1389 	/* Accept if non-secure or higher security level is required */
1390 	if (sec_level != BT_SECURITY_HIGH && sec_level != BT_SECURITY_FIPS)
1391 		return 1;
1392 
1393 	/* Accept if secure or higher security level is already present */
1394 	if (conn->sec_level == BT_SECURITY_HIGH ||
1395 	    conn->sec_level == BT_SECURITY_FIPS)
1396 		return 1;
1397 
1398 	/* Reject not secure link */
1399 	return 0;
1400 }
1401 EXPORT_SYMBOL(hci_conn_check_secure);
1402 
1403 /* Switch role */
1404 int hci_conn_switch_role(struct hci_conn *conn, __u8 role)
1405 {
1406 	BT_DBG("hcon %p", conn);
1407 
1408 	if (role == conn->role)
1409 		return 1;
1410 
1411 	if (!test_and_set_bit(HCI_CONN_RSWITCH_PEND, &conn->flags)) {
1412 		struct hci_cp_switch_role cp;
1413 		bacpy(&cp.bdaddr, &conn->dst);
1414 		cp.role = role;
1415 		hci_send_cmd(conn->hdev, HCI_OP_SWITCH_ROLE, sizeof(cp), &cp);
1416 	}
1417 
1418 	return 0;
1419 }
1420 EXPORT_SYMBOL(hci_conn_switch_role);
1421 
1422 /* Enter active mode */
1423 void hci_conn_enter_active_mode(struct hci_conn *conn, __u8 force_active)
1424 {
1425 	struct hci_dev *hdev = conn->hdev;
1426 
1427 	BT_DBG("hcon %p mode %d", conn, conn->mode);
1428 
1429 	if (conn->mode != HCI_CM_SNIFF)
1430 		goto timer;
1431 
1432 	if (!test_bit(HCI_CONN_POWER_SAVE, &conn->flags) && !force_active)
1433 		goto timer;
1434 
1435 	if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->flags)) {
1436 		struct hci_cp_exit_sniff_mode cp;
1437 		cp.handle = cpu_to_le16(conn->handle);
1438 		hci_send_cmd(hdev, HCI_OP_EXIT_SNIFF_MODE, sizeof(cp), &cp);
1439 	}
1440 
1441 timer:
1442 	if (hdev->idle_timeout > 0)
1443 		queue_delayed_work(hdev->workqueue, &conn->idle_work,
1444 				   msecs_to_jiffies(hdev->idle_timeout));
1445 }
1446 
1447 /* Drop all connection on the device */
1448 void hci_conn_hash_flush(struct hci_dev *hdev)
1449 {
1450 	struct hci_conn_hash *h = &hdev->conn_hash;
1451 	struct hci_conn *c, *n;
1452 
1453 	BT_DBG("hdev %s", hdev->name);
1454 
1455 	list_for_each_entry_safe(c, n, &h->list, list) {
1456 		c->state = BT_CLOSED;
1457 
1458 		hci_disconn_cfm(c, HCI_ERROR_LOCAL_HOST_TERM);
1459 		hci_conn_del(c);
1460 	}
1461 }
1462 
1463 /* Check pending connect attempts */
1464 void hci_conn_check_pending(struct hci_dev *hdev)
1465 {
1466 	struct hci_conn *conn;
1467 
1468 	BT_DBG("hdev %s", hdev->name);
1469 
1470 	hci_dev_lock(hdev);
1471 
1472 	conn = hci_conn_hash_lookup_state(hdev, ACL_LINK, BT_CONNECT2);
1473 	if (conn)
1474 		hci_acl_create_connection(conn);
1475 
1476 	hci_dev_unlock(hdev);
1477 }
1478 
1479 static u32 get_link_mode(struct hci_conn *conn)
1480 {
1481 	u32 link_mode = 0;
1482 
1483 	if (conn->role == HCI_ROLE_MASTER)
1484 		link_mode |= HCI_LM_MASTER;
1485 
1486 	if (test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1487 		link_mode |= HCI_LM_ENCRYPT;
1488 
1489 	if (test_bit(HCI_CONN_AUTH, &conn->flags))
1490 		link_mode |= HCI_LM_AUTH;
1491 
1492 	if (test_bit(HCI_CONN_SECURE, &conn->flags))
1493 		link_mode |= HCI_LM_SECURE;
1494 
1495 	if (test_bit(HCI_CONN_FIPS, &conn->flags))
1496 		link_mode |= HCI_LM_FIPS;
1497 
1498 	return link_mode;
1499 }
1500 
1501 int hci_get_conn_list(void __user *arg)
1502 {
1503 	struct hci_conn *c;
1504 	struct hci_conn_list_req req, *cl;
1505 	struct hci_conn_info *ci;
1506 	struct hci_dev *hdev;
1507 	int n = 0, size, err;
1508 
1509 	if (copy_from_user(&req, arg, sizeof(req)))
1510 		return -EFAULT;
1511 
1512 	if (!req.conn_num || req.conn_num > (PAGE_SIZE * 2) / sizeof(*ci))
1513 		return -EINVAL;
1514 
1515 	size = sizeof(req) + req.conn_num * sizeof(*ci);
1516 
1517 	cl = kmalloc(size, GFP_KERNEL);
1518 	if (!cl)
1519 		return -ENOMEM;
1520 
1521 	hdev = hci_dev_get(req.dev_id);
1522 	if (!hdev) {
1523 		kfree(cl);
1524 		return -ENODEV;
1525 	}
1526 
1527 	ci = cl->conn_info;
1528 
1529 	hci_dev_lock(hdev);
1530 	list_for_each_entry(c, &hdev->conn_hash.list, list) {
1531 		bacpy(&(ci + n)->bdaddr, &c->dst);
1532 		(ci + n)->handle = c->handle;
1533 		(ci + n)->type  = c->type;
1534 		(ci + n)->out   = c->out;
1535 		(ci + n)->state = c->state;
1536 		(ci + n)->link_mode = get_link_mode(c);
1537 		if (++n >= req.conn_num)
1538 			break;
1539 	}
1540 	hci_dev_unlock(hdev);
1541 
1542 	cl->dev_id = hdev->id;
1543 	cl->conn_num = n;
1544 	size = sizeof(req) + n * sizeof(*ci);
1545 
1546 	hci_dev_put(hdev);
1547 
1548 	err = copy_to_user(arg, cl, size);
1549 	kfree(cl);
1550 
1551 	return err ? -EFAULT : 0;
1552 }
1553 
1554 int hci_get_conn_info(struct hci_dev *hdev, void __user *arg)
1555 {
1556 	struct hci_conn_info_req req;
1557 	struct hci_conn_info ci;
1558 	struct hci_conn *conn;
1559 	char __user *ptr = arg + sizeof(req);
1560 
1561 	if (copy_from_user(&req, arg, sizeof(req)))
1562 		return -EFAULT;
1563 
1564 	hci_dev_lock(hdev);
1565 	conn = hci_conn_hash_lookup_ba(hdev, req.type, &req.bdaddr);
1566 	if (conn) {
1567 		bacpy(&ci.bdaddr, &conn->dst);
1568 		ci.handle = conn->handle;
1569 		ci.type  = conn->type;
1570 		ci.out   = conn->out;
1571 		ci.state = conn->state;
1572 		ci.link_mode = get_link_mode(conn);
1573 	}
1574 	hci_dev_unlock(hdev);
1575 
1576 	if (!conn)
1577 		return -ENOENT;
1578 
1579 	return copy_to_user(ptr, &ci, sizeof(ci)) ? -EFAULT : 0;
1580 }
1581 
1582 int hci_get_auth_info(struct hci_dev *hdev, void __user *arg)
1583 {
1584 	struct hci_auth_info_req req;
1585 	struct hci_conn *conn;
1586 
1587 	if (copy_from_user(&req, arg, sizeof(req)))
1588 		return -EFAULT;
1589 
1590 	hci_dev_lock(hdev);
1591 	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &req.bdaddr);
1592 	if (conn)
1593 		req.type = conn->auth_type;
1594 	hci_dev_unlock(hdev);
1595 
1596 	if (!conn)
1597 		return -ENOENT;
1598 
1599 	return copy_to_user(arg, &req, sizeof(req)) ? -EFAULT : 0;
1600 }
1601 
1602 struct hci_chan *hci_chan_create(struct hci_conn *conn)
1603 {
1604 	struct hci_dev *hdev = conn->hdev;
1605 	struct hci_chan *chan;
1606 
1607 	BT_DBG("%s hcon %p", hdev->name, conn);
1608 
1609 	if (test_bit(HCI_CONN_DROP, &conn->flags)) {
1610 		BT_DBG("Refusing to create new hci_chan");
1611 		return NULL;
1612 	}
1613 
1614 	chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1615 	if (!chan)
1616 		return NULL;
1617 
1618 	chan->conn = hci_conn_get(conn);
1619 	skb_queue_head_init(&chan->data_q);
1620 	chan->state = BT_CONNECTED;
1621 
1622 	list_add_rcu(&chan->list, &conn->chan_list);
1623 
1624 	return chan;
1625 }
1626 
1627 void hci_chan_del(struct hci_chan *chan)
1628 {
1629 	struct hci_conn *conn = chan->conn;
1630 	struct hci_dev *hdev = conn->hdev;
1631 
1632 	BT_DBG("%s hcon %p chan %p", hdev->name, conn, chan);
1633 
1634 	list_del_rcu(&chan->list);
1635 
1636 	synchronize_rcu();
1637 
1638 	/* Prevent new hci_chan's to be created for this hci_conn */
1639 	set_bit(HCI_CONN_DROP, &conn->flags);
1640 
1641 	hci_conn_put(conn);
1642 
1643 	skb_queue_purge(&chan->data_q);
1644 	kfree(chan);
1645 }
1646 
1647 void hci_chan_list_flush(struct hci_conn *conn)
1648 {
1649 	struct hci_chan *chan, *n;
1650 
1651 	BT_DBG("hcon %p", conn);
1652 
1653 	list_for_each_entry_safe(chan, n, &conn->chan_list, list)
1654 		hci_chan_del(chan);
1655 }
1656 
1657 static struct hci_chan *__hci_chan_lookup_handle(struct hci_conn *hcon,
1658 						 __u16 handle)
1659 {
1660 	struct hci_chan *hchan;
1661 
1662 	list_for_each_entry(hchan, &hcon->chan_list, list) {
1663 		if (hchan->handle == handle)
1664 			return hchan;
1665 	}
1666 
1667 	return NULL;
1668 }
1669 
1670 struct hci_chan *hci_chan_lookup_handle(struct hci_dev *hdev, __u16 handle)
1671 {
1672 	struct hci_conn_hash *h = &hdev->conn_hash;
1673 	struct hci_conn *hcon;
1674 	struct hci_chan *hchan = NULL;
1675 
1676 	rcu_read_lock();
1677 
1678 	list_for_each_entry_rcu(hcon, &h->list, list) {
1679 		hchan = __hci_chan_lookup_handle(hcon, handle);
1680 		if (hchan)
1681 			break;
1682 	}
1683 
1684 	rcu_read_unlock();
1685 
1686 	return hchan;
1687 }
1688 
1689 u32 hci_conn_get_phy(struct hci_conn *conn)
1690 {
1691 	u32 phys = 0;
1692 
1693 	/* BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 2, Part B page 471:
1694 	 * Table 6.2: Packets defined for synchronous, asynchronous, and
1695 	 * CPB logical transport types.
1696 	 */
1697 	switch (conn->type) {
1698 	case SCO_LINK:
1699 		/* SCO logical transport (1 Mb/s):
1700 		 * HV1, HV2, HV3 and DV.
1701 		 */
1702 		phys |= BT_PHY_BR_1M_1SLOT;
1703 
1704 		break;
1705 
1706 	case ACL_LINK:
1707 		/* ACL logical transport (1 Mb/s) ptt=0:
1708 		 * DH1, DM3, DH3, DM5 and DH5.
1709 		 */
1710 		phys |= BT_PHY_BR_1M_1SLOT;
1711 
1712 		if (conn->pkt_type & (HCI_DM3 | HCI_DH3))
1713 			phys |= BT_PHY_BR_1M_3SLOT;
1714 
1715 		if (conn->pkt_type & (HCI_DM5 | HCI_DH5))
1716 			phys |= BT_PHY_BR_1M_5SLOT;
1717 
1718 		/* ACL logical transport (2 Mb/s) ptt=1:
1719 		 * 2-DH1, 2-DH3 and 2-DH5.
1720 		 */
1721 		if (!(conn->pkt_type & HCI_2DH1))
1722 			phys |= BT_PHY_EDR_2M_1SLOT;
1723 
1724 		if (!(conn->pkt_type & HCI_2DH3))
1725 			phys |= BT_PHY_EDR_2M_3SLOT;
1726 
1727 		if (!(conn->pkt_type & HCI_2DH5))
1728 			phys |= BT_PHY_EDR_2M_5SLOT;
1729 
1730 		/* ACL logical transport (3 Mb/s) ptt=1:
1731 		 * 3-DH1, 3-DH3 and 3-DH5.
1732 		 */
1733 		if (!(conn->pkt_type & HCI_3DH1))
1734 			phys |= BT_PHY_EDR_3M_1SLOT;
1735 
1736 		if (!(conn->pkt_type & HCI_3DH3))
1737 			phys |= BT_PHY_EDR_3M_3SLOT;
1738 
1739 		if (!(conn->pkt_type & HCI_3DH5))
1740 			phys |= BT_PHY_EDR_3M_5SLOT;
1741 
1742 		break;
1743 
1744 	case ESCO_LINK:
1745 		/* eSCO logical transport (1 Mb/s): EV3, EV4 and EV5 */
1746 		phys |= BT_PHY_BR_1M_1SLOT;
1747 
1748 		if (!(conn->pkt_type & (ESCO_EV4 | ESCO_EV5)))
1749 			phys |= BT_PHY_BR_1M_3SLOT;
1750 
1751 		/* eSCO logical transport (2 Mb/s): 2-EV3, 2-EV5 */
1752 		if (!(conn->pkt_type & ESCO_2EV3))
1753 			phys |= BT_PHY_EDR_2M_1SLOT;
1754 
1755 		if (!(conn->pkt_type & ESCO_2EV5))
1756 			phys |= BT_PHY_EDR_2M_3SLOT;
1757 
1758 		/* eSCO logical transport (3 Mb/s): 3-EV3, 3-EV5 */
1759 		if (!(conn->pkt_type & ESCO_3EV3))
1760 			phys |= BT_PHY_EDR_3M_1SLOT;
1761 
1762 		if (!(conn->pkt_type & ESCO_3EV5))
1763 			phys |= BT_PHY_EDR_3M_3SLOT;
1764 
1765 		break;
1766 
1767 	case LE_LINK:
1768 		if (conn->le_tx_phy & HCI_LE_SET_PHY_1M)
1769 			phys |= BT_PHY_LE_1M_TX;
1770 
1771 		if (conn->le_rx_phy & HCI_LE_SET_PHY_1M)
1772 			phys |= BT_PHY_LE_1M_RX;
1773 
1774 		if (conn->le_tx_phy & HCI_LE_SET_PHY_2M)
1775 			phys |= BT_PHY_LE_2M_TX;
1776 
1777 		if (conn->le_rx_phy & HCI_LE_SET_PHY_2M)
1778 			phys |= BT_PHY_LE_2M_RX;
1779 
1780 		if (conn->le_tx_phy & HCI_LE_SET_PHY_CODED)
1781 			phys |= BT_PHY_LE_CODED_TX;
1782 
1783 		if (conn->le_rx_phy & HCI_LE_SET_PHY_CODED)
1784 			phys |= BT_PHY_LE_CODED_RX;
1785 
1786 		break;
1787 	}
1788 
1789 	return phys;
1790 }
1791