xref: /linux/net/bluetooth/hci_conn.c (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
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_sync_conn_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_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 static 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 	/* If the status indicates successful cancellation of
890 	 * the attempt (i.e. Unknown Connection Id) there's no point of
891 	 * notifying failure since we'll go back to keep trying to
892 	 * connect. The only exception is explicit connect requests
893 	 * where a timeout + cancel does indicate an actual failure.
894 	 */
895 	if (status != HCI_ERROR_UNKNOWN_CONN_ID ||
896 	    (params && params->explicit_connect))
897 		mgmt_connect_failed(hdev, &conn->dst, conn->type,
898 				    conn->dst_type, status);
899 
900 	/* Since we may have temporarily stopped the background scanning in
901 	 * favor of connection establishment, we should restart it.
902 	 */
903 	hci_update_passive_scan(hdev);
904 
905 	/* Enable advertising in case this was a failed connection
906 	 * attempt as a peripheral.
907 	 */
908 	hci_enable_advertising(hdev);
909 }
910 
911 /* This function requires the caller holds hdev->lock */
912 void hci_conn_failed(struct hci_conn *conn, u8 status)
913 {
914 	struct hci_dev *hdev = conn->hdev;
915 
916 	bt_dev_dbg(hdev, "status 0x%2.2x", status);
917 
918 	switch (conn->type) {
919 	case LE_LINK:
920 		hci_le_conn_failed(conn, status);
921 		break;
922 	case ACL_LINK:
923 		mgmt_connect_failed(hdev, &conn->dst, conn->type,
924 				    conn->dst_type, status);
925 		break;
926 	}
927 
928 	conn->state = BT_CLOSED;
929 	hci_connect_cfm(conn, status);
930 	hci_conn_del(conn);
931 }
932 
933 static void create_le_conn_complete(struct hci_dev *hdev, void *data, int err)
934 {
935 	struct hci_conn *conn = data;
936 
937 	hci_dev_lock(hdev);
938 
939 	if (!err) {
940 		hci_connect_le_scan_cleanup(conn);
941 		goto done;
942 	}
943 
944 	bt_dev_err(hdev, "request failed to create LE connection: err %d", err);
945 
946 	/* Check if connection is still pending */
947 	if (conn != hci_lookup_le_connect(hdev))
948 		goto done;
949 
950 	hci_conn_failed(conn, err);
951 
952 done:
953 	hci_dev_unlock(hdev);
954 }
955 
956 static int hci_connect_le_sync(struct hci_dev *hdev, void *data)
957 {
958 	struct hci_conn *conn = data;
959 
960 	bt_dev_dbg(hdev, "conn %p", conn);
961 
962 	return hci_le_create_conn_sync(hdev, conn);
963 }
964 
965 struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
966 				u8 dst_type, bool dst_resolved, u8 sec_level,
967 				u16 conn_timeout, u8 role)
968 {
969 	struct hci_conn *conn;
970 	struct smp_irk *irk;
971 	int err;
972 
973 	/* Let's make sure that le is enabled.*/
974 	if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) {
975 		if (lmp_le_capable(hdev))
976 			return ERR_PTR(-ECONNREFUSED);
977 
978 		return ERR_PTR(-EOPNOTSUPP);
979 	}
980 
981 	/* Since the controller supports only one LE connection attempt at a
982 	 * time, we return -EBUSY if there is any connection attempt running.
983 	 */
984 	if (hci_lookup_le_connect(hdev))
985 		return ERR_PTR(-EBUSY);
986 
987 	/* If there's already a connection object but it's not in
988 	 * scanning state it means it must already be established, in
989 	 * which case we can't do anything else except report a failure
990 	 * to connect.
991 	 */
992 	conn = hci_conn_hash_lookup_le(hdev, dst, dst_type);
993 	if (conn && !test_bit(HCI_CONN_SCANNING, &conn->flags)) {
994 		return ERR_PTR(-EBUSY);
995 	}
996 
997 	/* Check if the destination address has been resolved by the controller
998 	 * since if it did then the identity address shall be used.
999 	 */
1000 	if (!dst_resolved) {
1001 		/* When given an identity address with existing identity
1002 		 * resolving key, the connection needs to be established
1003 		 * to a resolvable random address.
1004 		 *
1005 		 * Storing the resolvable random address is required here
1006 		 * to handle connection failures. The address will later
1007 		 * be resolved back into the original identity address
1008 		 * from the connect request.
1009 		 */
1010 		irk = hci_find_irk_by_addr(hdev, dst, dst_type);
1011 		if (irk && bacmp(&irk->rpa, BDADDR_ANY)) {
1012 			dst = &irk->rpa;
1013 			dst_type = ADDR_LE_DEV_RANDOM;
1014 		}
1015 	}
1016 
1017 	if (conn) {
1018 		bacpy(&conn->dst, dst);
1019 	} else {
1020 		conn = hci_conn_add(hdev, LE_LINK, dst, role);
1021 		if (!conn)
1022 			return ERR_PTR(-ENOMEM);
1023 		hci_conn_hold(conn);
1024 		conn->pending_sec_level = sec_level;
1025 	}
1026 
1027 	conn->dst_type = dst_type;
1028 	conn->sec_level = BT_SECURITY_LOW;
1029 	conn->conn_timeout = conn_timeout;
1030 
1031 	conn->state = BT_CONNECT;
1032 	clear_bit(HCI_CONN_SCANNING, &conn->flags);
1033 
1034 	err = hci_cmd_sync_queue(hdev, hci_connect_le_sync, conn,
1035 				 create_le_conn_complete);
1036 	if (err) {
1037 		hci_conn_del(conn);
1038 		return ERR_PTR(err);
1039 	}
1040 
1041 	return conn;
1042 }
1043 
1044 static bool is_connected(struct hci_dev *hdev, bdaddr_t *addr, u8 type)
1045 {
1046 	struct hci_conn *conn;
1047 
1048 	conn = hci_conn_hash_lookup_le(hdev, addr, type);
1049 	if (!conn)
1050 		return false;
1051 
1052 	if (conn->state != BT_CONNECTED)
1053 		return false;
1054 
1055 	return true;
1056 }
1057 
1058 /* This function requires the caller holds hdev->lock */
1059 static int hci_explicit_conn_params_set(struct hci_dev *hdev,
1060 					bdaddr_t *addr, u8 addr_type)
1061 {
1062 	struct hci_conn_params *params;
1063 
1064 	if (is_connected(hdev, addr, addr_type))
1065 		return -EISCONN;
1066 
1067 	params = hci_conn_params_lookup(hdev, addr, addr_type);
1068 	if (!params) {
1069 		params = hci_conn_params_add(hdev, addr, addr_type);
1070 		if (!params)
1071 			return -ENOMEM;
1072 
1073 		/* If we created new params, mark them to be deleted in
1074 		 * hci_connect_le_scan_cleanup. It's different case than
1075 		 * existing disabled params, those will stay after cleanup.
1076 		 */
1077 		params->auto_connect = HCI_AUTO_CONN_EXPLICIT;
1078 	}
1079 
1080 	/* We're trying to connect, so make sure params are at pend_le_conns */
1081 	if (params->auto_connect == HCI_AUTO_CONN_DISABLED ||
1082 	    params->auto_connect == HCI_AUTO_CONN_REPORT ||
1083 	    params->auto_connect == HCI_AUTO_CONN_EXPLICIT) {
1084 		list_del_init(&params->action);
1085 		list_add(&params->action, &hdev->pend_le_conns);
1086 	}
1087 
1088 	params->explicit_connect = true;
1089 
1090 	BT_DBG("addr %pMR (type %u) auto_connect %u", addr, addr_type,
1091 	       params->auto_connect);
1092 
1093 	return 0;
1094 }
1095 
1096 /* This function requires the caller holds hdev->lock */
1097 struct hci_conn *hci_connect_le_scan(struct hci_dev *hdev, bdaddr_t *dst,
1098 				     u8 dst_type, u8 sec_level,
1099 				     u16 conn_timeout,
1100 				     enum conn_reasons conn_reason)
1101 {
1102 	struct hci_conn *conn;
1103 
1104 	/* Let's make sure that le is enabled.*/
1105 	if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) {
1106 		if (lmp_le_capable(hdev))
1107 			return ERR_PTR(-ECONNREFUSED);
1108 
1109 		return ERR_PTR(-EOPNOTSUPP);
1110 	}
1111 
1112 	/* Some devices send ATT messages as soon as the physical link is
1113 	 * established. To be able to handle these ATT messages, the user-
1114 	 * space first establishes the connection and then starts the pairing
1115 	 * process.
1116 	 *
1117 	 * So if a hci_conn object already exists for the following connection
1118 	 * attempt, we simply update pending_sec_level and auth_type fields
1119 	 * and return the object found.
1120 	 */
1121 	conn = hci_conn_hash_lookup_le(hdev, dst, dst_type);
1122 	if (conn) {
1123 		if (conn->pending_sec_level < sec_level)
1124 			conn->pending_sec_level = sec_level;
1125 		goto done;
1126 	}
1127 
1128 	BT_DBG("requesting refresh of dst_addr");
1129 
1130 	conn = hci_conn_add(hdev, LE_LINK, dst, HCI_ROLE_MASTER);
1131 	if (!conn)
1132 		return ERR_PTR(-ENOMEM);
1133 
1134 	if (hci_explicit_conn_params_set(hdev, dst, dst_type) < 0) {
1135 		hci_conn_del(conn);
1136 		return ERR_PTR(-EBUSY);
1137 	}
1138 
1139 	conn->state = BT_CONNECT;
1140 	set_bit(HCI_CONN_SCANNING, &conn->flags);
1141 	conn->dst_type = dst_type;
1142 	conn->sec_level = BT_SECURITY_LOW;
1143 	conn->pending_sec_level = sec_level;
1144 	conn->conn_timeout = conn_timeout;
1145 	conn->conn_reason = conn_reason;
1146 
1147 	hci_update_passive_scan(hdev);
1148 
1149 done:
1150 	hci_conn_hold(conn);
1151 	return conn;
1152 }
1153 
1154 struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
1155 				 u8 sec_level, u8 auth_type,
1156 				 enum conn_reasons conn_reason)
1157 {
1158 	struct hci_conn *acl;
1159 
1160 	if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED)) {
1161 		if (lmp_bredr_capable(hdev))
1162 			return ERR_PTR(-ECONNREFUSED);
1163 
1164 		return ERR_PTR(-EOPNOTSUPP);
1165 	}
1166 
1167 	acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
1168 	if (!acl) {
1169 		acl = hci_conn_add(hdev, ACL_LINK, dst, HCI_ROLE_MASTER);
1170 		if (!acl)
1171 			return ERR_PTR(-ENOMEM);
1172 	}
1173 
1174 	hci_conn_hold(acl);
1175 
1176 	acl->conn_reason = conn_reason;
1177 	if (acl->state == BT_OPEN || acl->state == BT_CLOSED) {
1178 		acl->sec_level = BT_SECURITY_LOW;
1179 		acl->pending_sec_level = sec_level;
1180 		acl->auth_type = auth_type;
1181 		hci_acl_create_connection(acl);
1182 	}
1183 
1184 	return acl;
1185 }
1186 
1187 struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type, bdaddr_t *dst,
1188 				 __u16 setting, struct bt_codec *codec)
1189 {
1190 	struct hci_conn *acl;
1191 	struct hci_conn *sco;
1192 
1193 	acl = hci_connect_acl(hdev, dst, BT_SECURITY_LOW, HCI_AT_NO_BONDING,
1194 			      CONN_REASON_SCO_CONNECT);
1195 	if (IS_ERR(acl))
1196 		return acl;
1197 
1198 	sco = hci_conn_hash_lookup_ba(hdev, type, dst);
1199 	if (!sco) {
1200 		sco = hci_conn_add(hdev, type, dst, HCI_ROLE_MASTER);
1201 		if (!sco) {
1202 			hci_conn_drop(acl);
1203 			return ERR_PTR(-ENOMEM);
1204 		}
1205 	}
1206 
1207 	acl->link = sco;
1208 	sco->link = acl;
1209 
1210 	hci_conn_hold(sco);
1211 
1212 	sco->setting = setting;
1213 	sco->codec = *codec;
1214 
1215 	if (acl->state == BT_CONNECTED &&
1216 	    (sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
1217 		set_bit(HCI_CONN_POWER_SAVE, &acl->flags);
1218 		hci_conn_enter_active_mode(acl, BT_POWER_FORCE_ACTIVE_ON);
1219 
1220 		if (test_bit(HCI_CONN_MODE_CHANGE_PEND, &acl->flags)) {
1221 			/* defer SCO setup until mode change completed */
1222 			set_bit(HCI_CONN_SCO_SETUP_PEND, &acl->flags);
1223 			return sco;
1224 		}
1225 
1226 		hci_sco_setup(acl, 0x00);
1227 	}
1228 
1229 	return sco;
1230 }
1231 
1232 /* Check link security requirement */
1233 int hci_conn_check_link_mode(struct hci_conn *conn)
1234 {
1235 	BT_DBG("hcon %p", conn);
1236 
1237 	/* In Secure Connections Only mode, it is required that Secure
1238 	 * Connections is used and the link is encrypted with AES-CCM
1239 	 * using a P-256 authenticated combination key.
1240 	 */
1241 	if (hci_dev_test_flag(conn->hdev, HCI_SC_ONLY)) {
1242 		if (!hci_conn_sc_enabled(conn) ||
1243 		    !test_bit(HCI_CONN_AES_CCM, &conn->flags) ||
1244 		    conn->key_type != HCI_LK_AUTH_COMBINATION_P256)
1245 			return 0;
1246 	}
1247 
1248 	 /* AES encryption is required for Level 4:
1249 	  *
1250 	  * BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 3, Part C
1251 	  * page 1319:
1252 	  *
1253 	  * 128-bit equivalent strength for link and encryption keys
1254 	  * required using FIPS approved algorithms (E0 not allowed,
1255 	  * SAFER+ not allowed, and P-192 not allowed; encryption key
1256 	  * not shortened)
1257 	  */
1258 	if (conn->sec_level == BT_SECURITY_FIPS &&
1259 	    !test_bit(HCI_CONN_AES_CCM, &conn->flags)) {
1260 		bt_dev_err(conn->hdev,
1261 			   "Invalid security: Missing AES-CCM usage");
1262 		return 0;
1263 	}
1264 
1265 	if (hci_conn_ssp_enabled(conn) &&
1266 	    !test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1267 		return 0;
1268 
1269 	return 1;
1270 }
1271 
1272 /* Authenticate remote device */
1273 static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
1274 {
1275 	BT_DBG("hcon %p", conn);
1276 
1277 	if (conn->pending_sec_level > sec_level)
1278 		sec_level = conn->pending_sec_level;
1279 
1280 	if (sec_level > conn->sec_level)
1281 		conn->pending_sec_level = sec_level;
1282 	else if (test_bit(HCI_CONN_AUTH, &conn->flags))
1283 		return 1;
1284 
1285 	/* Make sure we preserve an existing MITM requirement*/
1286 	auth_type |= (conn->auth_type & 0x01);
1287 
1288 	conn->auth_type = auth_type;
1289 
1290 	if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->flags)) {
1291 		struct hci_cp_auth_requested cp;
1292 
1293 		cp.handle = cpu_to_le16(conn->handle);
1294 		hci_send_cmd(conn->hdev, HCI_OP_AUTH_REQUESTED,
1295 			     sizeof(cp), &cp);
1296 
1297 		/* If we're already encrypted set the REAUTH_PEND flag,
1298 		 * otherwise set the ENCRYPT_PEND.
1299 		 */
1300 		if (test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1301 			set_bit(HCI_CONN_REAUTH_PEND, &conn->flags);
1302 		else
1303 			set_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags);
1304 	}
1305 
1306 	return 0;
1307 }
1308 
1309 /* Encrypt the link */
1310 static void hci_conn_encrypt(struct hci_conn *conn)
1311 {
1312 	BT_DBG("hcon %p", conn);
1313 
1314 	if (!test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags)) {
1315 		struct hci_cp_set_conn_encrypt cp;
1316 		cp.handle  = cpu_to_le16(conn->handle);
1317 		cp.encrypt = 0x01;
1318 		hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT, sizeof(cp),
1319 			     &cp);
1320 	}
1321 }
1322 
1323 /* Enable security */
1324 int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type,
1325 		      bool initiator)
1326 {
1327 	BT_DBG("hcon %p", conn);
1328 
1329 	if (conn->type == LE_LINK)
1330 		return smp_conn_security(conn, sec_level);
1331 
1332 	/* For sdp we don't need the link key. */
1333 	if (sec_level == BT_SECURITY_SDP)
1334 		return 1;
1335 
1336 	/* For non 2.1 devices and low security level we don't need the link
1337 	   key. */
1338 	if (sec_level == BT_SECURITY_LOW && !hci_conn_ssp_enabled(conn))
1339 		return 1;
1340 
1341 	/* For other security levels we need the link key. */
1342 	if (!test_bit(HCI_CONN_AUTH, &conn->flags))
1343 		goto auth;
1344 
1345 	/* An authenticated FIPS approved combination key has sufficient
1346 	 * security for security level 4. */
1347 	if (conn->key_type == HCI_LK_AUTH_COMBINATION_P256 &&
1348 	    sec_level == BT_SECURITY_FIPS)
1349 		goto encrypt;
1350 
1351 	/* An authenticated combination key has sufficient security for
1352 	   security level 3. */
1353 	if ((conn->key_type == HCI_LK_AUTH_COMBINATION_P192 ||
1354 	     conn->key_type == HCI_LK_AUTH_COMBINATION_P256) &&
1355 	    sec_level == BT_SECURITY_HIGH)
1356 		goto encrypt;
1357 
1358 	/* An unauthenticated combination key has sufficient security for
1359 	   security level 1 and 2. */
1360 	if ((conn->key_type == HCI_LK_UNAUTH_COMBINATION_P192 ||
1361 	     conn->key_type == HCI_LK_UNAUTH_COMBINATION_P256) &&
1362 	    (sec_level == BT_SECURITY_MEDIUM || sec_level == BT_SECURITY_LOW))
1363 		goto encrypt;
1364 
1365 	/* A combination key has always sufficient security for the security
1366 	   levels 1 or 2. High security level requires the combination key
1367 	   is generated using maximum PIN code length (16).
1368 	   For pre 2.1 units. */
1369 	if (conn->key_type == HCI_LK_COMBINATION &&
1370 	    (sec_level == BT_SECURITY_MEDIUM || sec_level == BT_SECURITY_LOW ||
1371 	     conn->pin_length == 16))
1372 		goto encrypt;
1373 
1374 auth:
1375 	if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags))
1376 		return 0;
1377 
1378 	if (initiator)
1379 		set_bit(HCI_CONN_AUTH_INITIATOR, &conn->flags);
1380 
1381 	if (!hci_conn_auth(conn, sec_level, auth_type))
1382 		return 0;
1383 
1384 encrypt:
1385 	if (test_bit(HCI_CONN_ENCRYPT, &conn->flags)) {
1386 		/* Ensure that the encryption key size has been read,
1387 		 * otherwise stall the upper layer responses.
1388 		 */
1389 		if (!conn->enc_key_size)
1390 			return 0;
1391 
1392 		/* Nothing else needed, all requirements are met */
1393 		return 1;
1394 	}
1395 
1396 	hci_conn_encrypt(conn);
1397 	return 0;
1398 }
1399 EXPORT_SYMBOL(hci_conn_security);
1400 
1401 /* Check secure link requirement */
1402 int hci_conn_check_secure(struct hci_conn *conn, __u8 sec_level)
1403 {
1404 	BT_DBG("hcon %p", conn);
1405 
1406 	/* Accept if non-secure or higher security level is required */
1407 	if (sec_level != BT_SECURITY_HIGH && sec_level != BT_SECURITY_FIPS)
1408 		return 1;
1409 
1410 	/* Accept if secure or higher security level is already present */
1411 	if (conn->sec_level == BT_SECURITY_HIGH ||
1412 	    conn->sec_level == BT_SECURITY_FIPS)
1413 		return 1;
1414 
1415 	/* Reject not secure link */
1416 	return 0;
1417 }
1418 EXPORT_SYMBOL(hci_conn_check_secure);
1419 
1420 /* Switch role */
1421 int hci_conn_switch_role(struct hci_conn *conn, __u8 role)
1422 {
1423 	BT_DBG("hcon %p", conn);
1424 
1425 	if (role == conn->role)
1426 		return 1;
1427 
1428 	if (!test_and_set_bit(HCI_CONN_RSWITCH_PEND, &conn->flags)) {
1429 		struct hci_cp_switch_role cp;
1430 		bacpy(&cp.bdaddr, &conn->dst);
1431 		cp.role = role;
1432 		hci_send_cmd(conn->hdev, HCI_OP_SWITCH_ROLE, sizeof(cp), &cp);
1433 	}
1434 
1435 	return 0;
1436 }
1437 EXPORT_SYMBOL(hci_conn_switch_role);
1438 
1439 /* Enter active mode */
1440 void hci_conn_enter_active_mode(struct hci_conn *conn, __u8 force_active)
1441 {
1442 	struct hci_dev *hdev = conn->hdev;
1443 
1444 	BT_DBG("hcon %p mode %d", conn, conn->mode);
1445 
1446 	if (conn->mode != HCI_CM_SNIFF)
1447 		goto timer;
1448 
1449 	if (!test_bit(HCI_CONN_POWER_SAVE, &conn->flags) && !force_active)
1450 		goto timer;
1451 
1452 	if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->flags)) {
1453 		struct hci_cp_exit_sniff_mode cp;
1454 		cp.handle = cpu_to_le16(conn->handle);
1455 		hci_send_cmd(hdev, HCI_OP_EXIT_SNIFF_MODE, sizeof(cp), &cp);
1456 	}
1457 
1458 timer:
1459 	if (hdev->idle_timeout > 0)
1460 		queue_delayed_work(hdev->workqueue, &conn->idle_work,
1461 				   msecs_to_jiffies(hdev->idle_timeout));
1462 }
1463 
1464 /* Drop all connection on the device */
1465 void hci_conn_hash_flush(struct hci_dev *hdev)
1466 {
1467 	struct hci_conn_hash *h = &hdev->conn_hash;
1468 	struct hci_conn *c, *n;
1469 
1470 	BT_DBG("hdev %s", hdev->name);
1471 
1472 	list_for_each_entry_safe(c, n, &h->list, list) {
1473 		c->state = BT_CLOSED;
1474 
1475 		hci_disconn_cfm(c, HCI_ERROR_LOCAL_HOST_TERM);
1476 		hci_conn_del(c);
1477 	}
1478 }
1479 
1480 /* Check pending connect attempts */
1481 void hci_conn_check_pending(struct hci_dev *hdev)
1482 {
1483 	struct hci_conn *conn;
1484 
1485 	BT_DBG("hdev %s", hdev->name);
1486 
1487 	hci_dev_lock(hdev);
1488 
1489 	conn = hci_conn_hash_lookup_state(hdev, ACL_LINK, BT_CONNECT2);
1490 	if (conn)
1491 		hci_acl_create_connection(conn);
1492 
1493 	hci_dev_unlock(hdev);
1494 }
1495 
1496 static u32 get_link_mode(struct hci_conn *conn)
1497 {
1498 	u32 link_mode = 0;
1499 
1500 	if (conn->role == HCI_ROLE_MASTER)
1501 		link_mode |= HCI_LM_MASTER;
1502 
1503 	if (test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1504 		link_mode |= HCI_LM_ENCRYPT;
1505 
1506 	if (test_bit(HCI_CONN_AUTH, &conn->flags))
1507 		link_mode |= HCI_LM_AUTH;
1508 
1509 	if (test_bit(HCI_CONN_SECURE, &conn->flags))
1510 		link_mode |= HCI_LM_SECURE;
1511 
1512 	if (test_bit(HCI_CONN_FIPS, &conn->flags))
1513 		link_mode |= HCI_LM_FIPS;
1514 
1515 	return link_mode;
1516 }
1517 
1518 int hci_get_conn_list(void __user *arg)
1519 {
1520 	struct hci_conn *c;
1521 	struct hci_conn_list_req req, *cl;
1522 	struct hci_conn_info *ci;
1523 	struct hci_dev *hdev;
1524 	int n = 0, size, err;
1525 
1526 	if (copy_from_user(&req, arg, sizeof(req)))
1527 		return -EFAULT;
1528 
1529 	if (!req.conn_num || req.conn_num > (PAGE_SIZE * 2) / sizeof(*ci))
1530 		return -EINVAL;
1531 
1532 	size = sizeof(req) + req.conn_num * sizeof(*ci);
1533 
1534 	cl = kmalloc(size, GFP_KERNEL);
1535 	if (!cl)
1536 		return -ENOMEM;
1537 
1538 	hdev = hci_dev_get(req.dev_id);
1539 	if (!hdev) {
1540 		kfree(cl);
1541 		return -ENODEV;
1542 	}
1543 
1544 	ci = cl->conn_info;
1545 
1546 	hci_dev_lock(hdev);
1547 	list_for_each_entry(c, &hdev->conn_hash.list, list) {
1548 		bacpy(&(ci + n)->bdaddr, &c->dst);
1549 		(ci + n)->handle = c->handle;
1550 		(ci + n)->type  = c->type;
1551 		(ci + n)->out   = c->out;
1552 		(ci + n)->state = c->state;
1553 		(ci + n)->link_mode = get_link_mode(c);
1554 		if (++n >= req.conn_num)
1555 			break;
1556 	}
1557 	hci_dev_unlock(hdev);
1558 
1559 	cl->dev_id = hdev->id;
1560 	cl->conn_num = n;
1561 	size = sizeof(req) + n * sizeof(*ci);
1562 
1563 	hci_dev_put(hdev);
1564 
1565 	err = copy_to_user(arg, cl, size);
1566 	kfree(cl);
1567 
1568 	return err ? -EFAULT : 0;
1569 }
1570 
1571 int hci_get_conn_info(struct hci_dev *hdev, void __user *arg)
1572 {
1573 	struct hci_conn_info_req req;
1574 	struct hci_conn_info ci;
1575 	struct hci_conn *conn;
1576 	char __user *ptr = arg + sizeof(req);
1577 
1578 	if (copy_from_user(&req, arg, sizeof(req)))
1579 		return -EFAULT;
1580 
1581 	hci_dev_lock(hdev);
1582 	conn = hci_conn_hash_lookup_ba(hdev, req.type, &req.bdaddr);
1583 	if (conn) {
1584 		bacpy(&ci.bdaddr, &conn->dst);
1585 		ci.handle = conn->handle;
1586 		ci.type  = conn->type;
1587 		ci.out   = conn->out;
1588 		ci.state = conn->state;
1589 		ci.link_mode = get_link_mode(conn);
1590 	}
1591 	hci_dev_unlock(hdev);
1592 
1593 	if (!conn)
1594 		return -ENOENT;
1595 
1596 	return copy_to_user(ptr, &ci, sizeof(ci)) ? -EFAULT : 0;
1597 }
1598 
1599 int hci_get_auth_info(struct hci_dev *hdev, void __user *arg)
1600 {
1601 	struct hci_auth_info_req req;
1602 	struct hci_conn *conn;
1603 
1604 	if (copy_from_user(&req, arg, sizeof(req)))
1605 		return -EFAULT;
1606 
1607 	hci_dev_lock(hdev);
1608 	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &req.bdaddr);
1609 	if (conn)
1610 		req.type = conn->auth_type;
1611 	hci_dev_unlock(hdev);
1612 
1613 	if (!conn)
1614 		return -ENOENT;
1615 
1616 	return copy_to_user(arg, &req, sizeof(req)) ? -EFAULT : 0;
1617 }
1618 
1619 struct hci_chan *hci_chan_create(struct hci_conn *conn)
1620 {
1621 	struct hci_dev *hdev = conn->hdev;
1622 	struct hci_chan *chan;
1623 
1624 	BT_DBG("%s hcon %p", hdev->name, conn);
1625 
1626 	if (test_bit(HCI_CONN_DROP, &conn->flags)) {
1627 		BT_DBG("Refusing to create new hci_chan");
1628 		return NULL;
1629 	}
1630 
1631 	chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1632 	if (!chan)
1633 		return NULL;
1634 
1635 	chan->conn = hci_conn_get(conn);
1636 	skb_queue_head_init(&chan->data_q);
1637 	chan->state = BT_CONNECTED;
1638 
1639 	list_add_rcu(&chan->list, &conn->chan_list);
1640 
1641 	return chan;
1642 }
1643 
1644 void hci_chan_del(struct hci_chan *chan)
1645 {
1646 	struct hci_conn *conn = chan->conn;
1647 	struct hci_dev *hdev = conn->hdev;
1648 
1649 	BT_DBG("%s hcon %p chan %p", hdev->name, conn, chan);
1650 
1651 	list_del_rcu(&chan->list);
1652 
1653 	synchronize_rcu();
1654 
1655 	/* Prevent new hci_chan's to be created for this hci_conn */
1656 	set_bit(HCI_CONN_DROP, &conn->flags);
1657 
1658 	hci_conn_put(conn);
1659 
1660 	skb_queue_purge(&chan->data_q);
1661 	kfree(chan);
1662 }
1663 
1664 void hci_chan_list_flush(struct hci_conn *conn)
1665 {
1666 	struct hci_chan *chan, *n;
1667 
1668 	BT_DBG("hcon %p", conn);
1669 
1670 	list_for_each_entry_safe(chan, n, &conn->chan_list, list)
1671 		hci_chan_del(chan);
1672 }
1673 
1674 static struct hci_chan *__hci_chan_lookup_handle(struct hci_conn *hcon,
1675 						 __u16 handle)
1676 {
1677 	struct hci_chan *hchan;
1678 
1679 	list_for_each_entry(hchan, &hcon->chan_list, list) {
1680 		if (hchan->handle == handle)
1681 			return hchan;
1682 	}
1683 
1684 	return NULL;
1685 }
1686 
1687 struct hci_chan *hci_chan_lookup_handle(struct hci_dev *hdev, __u16 handle)
1688 {
1689 	struct hci_conn_hash *h = &hdev->conn_hash;
1690 	struct hci_conn *hcon;
1691 	struct hci_chan *hchan = NULL;
1692 
1693 	rcu_read_lock();
1694 
1695 	list_for_each_entry_rcu(hcon, &h->list, list) {
1696 		hchan = __hci_chan_lookup_handle(hcon, handle);
1697 		if (hchan)
1698 			break;
1699 	}
1700 
1701 	rcu_read_unlock();
1702 
1703 	return hchan;
1704 }
1705 
1706 u32 hci_conn_get_phy(struct hci_conn *conn)
1707 {
1708 	u32 phys = 0;
1709 
1710 	/* BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 2, Part B page 471:
1711 	 * Table 6.2: Packets defined for synchronous, asynchronous, and
1712 	 * CPB logical transport types.
1713 	 */
1714 	switch (conn->type) {
1715 	case SCO_LINK:
1716 		/* SCO logical transport (1 Mb/s):
1717 		 * HV1, HV2, HV3 and DV.
1718 		 */
1719 		phys |= BT_PHY_BR_1M_1SLOT;
1720 
1721 		break;
1722 
1723 	case ACL_LINK:
1724 		/* ACL logical transport (1 Mb/s) ptt=0:
1725 		 * DH1, DM3, DH3, DM5 and DH5.
1726 		 */
1727 		phys |= BT_PHY_BR_1M_1SLOT;
1728 
1729 		if (conn->pkt_type & (HCI_DM3 | HCI_DH3))
1730 			phys |= BT_PHY_BR_1M_3SLOT;
1731 
1732 		if (conn->pkt_type & (HCI_DM5 | HCI_DH5))
1733 			phys |= BT_PHY_BR_1M_5SLOT;
1734 
1735 		/* ACL logical transport (2 Mb/s) ptt=1:
1736 		 * 2-DH1, 2-DH3 and 2-DH5.
1737 		 */
1738 		if (!(conn->pkt_type & HCI_2DH1))
1739 			phys |= BT_PHY_EDR_2M_1SLOT;
1740 
1741 		if (!(conn->pkt_type & HCI_2DH3))
1742 			phys |= BT_PHY_EDR_2M_3SLOT;
1743 
1744 		if (!(conn->pkt_type & HCI_2DH5))
1745 			phys |= BT_PHY_EDR_2M_5SLOT;
1746 
1747 		/* ACL logical transport (3 Mb/s) ptt=1:
1748 		 * 3-DH1, 3-DH3 and 3-DH5.
1749 		 */
1750 		if (!(conn->pkt_type & HCI_3DH1))
1751 			phys |= BT_PHY_EDR_3M_1SLOT;
1752 
1753 		if (!(conn->pkt_type & HCI_3DH3))
1754 			phys |= BT_PHY_EDR_3M_3SLOT;
1755 
1756 		if (!(conn->pkt_type & HCI_3DH5))
1757 			phys |= BT_PHY_EDR_3M_5SLOT;
1758 
1759 		break;
1760 
1761 	case ESCO_LINK:
1762 		/* eSCO logical transport (1 Mb/s): EV3, EV4 and EV5 */
1763 		phys |= BT_PHY_BR_1M_1SLOT;
1764 
1765 		if (!(conn->pkt_type & (ESCO_EV4 | ESCO_EV5)))
1766 			phys |= BT_PHY_BR_1M_3SLOT;
1767 
1768 		/* eSCO logical transport (2 Mb/s): 2-EV3, 2-EV5 */
1769 		if (!(conn->pkt_type & ESCO_2EV3))
1770 			phys |= BT_PHY_EDR_2M_1SLOT;
1771 
1772 		if (!(conn->pkt_type & ESCO_2EV5))
1773 			phys |= BT_PHY_EDR_2M_3SLOT;
1774 
1775 		/* eSCO logical transport (3 Mb/s): 3-EV3, 3-EV5 */
1776 		if (!(conn->pkt_type & ESCO_3EV3))
1777 			phys |= BT_PHY_EDR_3M_1SLOT;
1778 
1779 		if (!(conn->pkt_type & ESCO_3EV5))
1780 			phys |= BT_PHY_EDR_3M_3SLOT;
1781 
1782 		break;
1783 
1784 	case LE_LINK:
1785 		if (conn->le_tx_phy & HCI_LE_SET_PHY_1M)
1786 			phys |= BT_PHY_LE_1M_TX;
1787 
1788 		if (conn->le_rx_phy & HCI_LE_SET_PHY_1M)
1789 			phys |= BT_PHY_LE_1M_RX;
1790 
1791 		if (conn->le_tx_phy & HCI_LE_SET_PHY_2M)
1792 			phys |= BT_PHY_LE_2M_TX;
1793 
1794 		if (conn->le_rx_phy & HCI_LE_SET_PHY_2M)
1795 			phys |= BT_PHY_LE_2M_RX;
1796 
1797 		if (conn->le_tx_phy & HCI_LE_SET_PHY_CODED)
1798 			phys |= BT_PHY_LE_CODED_TX;
1799 
1800 		if (conn->le_rx_phy & HCI_LE_SET_PHY_CODED)
1801 			phys |= BT_PHY_LE_CODED_RX;
1802 
1803 		break;
1804 	}
1805 
1806 	return phys;
1807 }
1808