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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 */
hci_connect_le_scan_cleanup(struct hci_conn * conn)63 static void hci_connect_le_scan_cleanup(struct hci_conn *conn)
64 {
65 	struct hci_conn_params *params;
66 	struct hci_dev *hdev = conn->hdev;
67 	struct smp_irk *irk;
68 	bdaddr_t *bdaddr;
69 	u8 bdaddr_type;
70 
71 	bdaddr = &conn->dst;
72 	bdaddr_type = conn->dst_type;
73 
74 	/* Check if we need to convert to identity address */
75 	irk = hci_get_irk(hdev, bdaddr, bdaddr_type);
76 	if (irk) {
77 		bdaddr = &irk->bdaddr;
78 		bdaddr_type = irk->addr_type;
79 	}
80 
81 	params = hci_pend_le_action_lookup(&hdev->pend_le_conns, bdaddr,
82 					   bdaddr_type);
83 	if (!params || !params->explicit_connect)
84 		return;
85 
86 	/* The connection attempt was doing scan for new RPA, and is
87 	 * in scan phase. If params are not associated with any other
88 	 * autoconnect action, remove them completely. If they are, just unmark
89 	 * them as waiting for connection, by clearing explicit_connect field.
90 	 */
91 	params->explicit_connect = false;
92 
93 	list_del_init(&params->action);
94 
95 	switch (params->auto_connect) {
96 	case HCI_AUTO_CONN_EXPLICIT:
97 		hci_conn_params_del(hdev, bdaddr, bdaddr_type);
98 		/* return instead of break to avoid duplicate scan update */
99 		return;
100 	case HCI_AUTO_CONN_DIRECT:
101 	case HCI_AUTO_CONN_ALWAYS:
102 		list_add(&params->action, &hdev->pend_le_conns);
103 		break;
104 	case HCI_AUTO_CONN_REPORT:
105 		list_add(&params->action, &hdev->pend_le_reports);
106 		break;
107 	default:
108 		break;
109 	}
110 
111 	hci_update_background_scan(hdev);
112 }
113 
hci_conn_cleanup(struct hci_conn * conn)114 static void hci_conn_cleanup(struct hci_conn *conn)
115 {
116 	struct hci_dev *hdev = conn->hdev;
117 
118 	if (test_bit(HCI_CONN_PARAM_REMOVAL_PEND, &conn->flags))
119 		hci_conn_params_del(conn->hdev, &conn->dst, conn->dst_type);
120 
121 	hci_chan_list_flush(conn);
122 
123 	hci_conn_hash_del(hdev, conn);
124 
125 	if (hdev->notify)
126 		hdev->notify(hdev, HCI_NOTIFY_CONN_DEL);
127 
128 	hci_conn_del_sysfs(conn);
129 
130 	debugfs_remove_recursive(conn->debugfs);
131 
132 	hci_dev_put(hdev);
133 
134 	hci_conn_put(conn);
135 }
136 
le_scan_cleanup(struct work_struct * work)137 static void le_scan_cleanup(struct work_struct *work)
138 {
139 	struct hci_conn *conn = container_of(work, struct hci_conn,
140 					     le_scan_cleanup);
141 	struct hci_dev *hdev = conn->hdev;
142 	struct hci_conn *c = NULL;
143 
144 	BT_DBG("%s hcon %p", hdev->name, conn);
145 
146 	hci_dev_lock(hdev);
147 
148 	/* Check that the hci_conn is still around */
149 	rcu_read_lock();
150 	list_for_each_entry_rcu(c, &hdev->conn_hash.list, list) {
151 		if (c == conn)
152 			break;
153 	}
154 	rcu_read_unlock();
155 
156 	if (c == conn) {
157 		hci_connect_le_scan_cleanup(conn);
158 		hci_conn_cleanup(conn);
159 	}
160 
161 	hci_dev_unlock(hdev);
162 	hci_dev_put(hdev);
163 	hci_conn_put(conn);
164 }
165 
hci_connect_le_scan_remove(struct hci_conn * conn)166 static void hci_connect_le_scan_remove(struct hci_conn *conn)
167 {
168 	BT_DBG("%s hcon %p", conn->hdev->name, conn);
169 
170 	/* We can't call hci_conn_del/hci_conn_cleanup here since that
171 	 * could deadlock with another hci_conn_del() call that's holding
172 	 * hci_dev_lock and doing cancel_delayed_work_sync(&conn->disc_work).
173 	 * Instead, grab temporary extra references to the hci_dev and
174 	 * hci_conn and perform the necessary cleanup in a separate work
175 	 * callback.
176 	 */
177 
178 	hci_dev_hold(conn->hdev);
179 	hci_conn_get(conn);
180 
181 	schedule_work(&conn->le_scan_cleanup);
182 }
183 
hci_acl_create_connection(struct hci_conn * conn)184 static void hci_acl_create_connection(struct hci_conn *conn)
185 {
186 	struct hci_dev *hdev = conn->hdev;
187 	struct inquiry_entry *ie;
188 	struct hci_cp_create_conn cp;
189 
190 	BT_DBG("hcon %p", conn);
191 
192 	conn->state = BT_CONNECT;
193 	conn->out = true;
194 	conn->role = HCI_ROLE_MASTER;
195 
196 	conn->attempt++;
197 
198 	conn->link_policy = hdev->link_policy;
199 
200 	memset(&cp, 0, sizeof(cp));
201 	bacpy(&cp.bdaddr, &conn->dst);
202 	cp.pscan_rep_mode = 0x02;
203 
204 	ie = hci_inquiry_cache_lookup(hdev, &conn->dst);
205 	if (ie) {
206 		if (inquiry_entry_age(ie) <= INQUIRY_ENTRY_AGE_MAX) {
207 			cp.pscan_rep_mode = ie->data.pscan_rep_mode;
208 			cp.pscan_mode     = ie->data.pscan_mode;
209 			cp.clock_offset   = ie->data.clock_offset |
210 					    cpu_to_le16(0x8000);
211 		}
212 
213 		memcpy(conn->dev_class, ie->data.dev_class, 3);
214 		if (ie->data.ssp_mode > 0)
215 			set_bit(HCI_CONN_SSP_ENABLED, &conn->flags);
216 	}
217 
218 	cp.pkt_type = cpu_to_le16(conn->pkt_type);
219 	if (lmp_rswitch_capable(hdev) && !(hdev->link_mode & HCI_LM_MASTER))
220 		cp.role_switch = 0x01;
221 	else
222 		cp.role_switch = 0x00;
223 
224 	hci_send_cmd(hdev, HCI_OP_CREATE_CONN, sizeof(cp), &cp);
225 }
226 
hci_disconnect(struct hci_conn * conn,__u8 reason)227 int hci_disconnect(struct hci_conn *conn, __u8 reason)
228 {
229 	BT_DBG("hcon %p", conn);
230 
231 	/* When we are master of an established connection and it enters
232 	 * the disconnect timeout, then go ahead and try to read the
233 	 * current clock offset.  Processing of the result is done
234 	 * within the event handling and hci_clock_offset_evt function.
235 	 */
236 	if (conn->type == ACL_LINK && conn->role == HCI_ROLE_MASTER &&
237 	    (conn->state == BT_CONNECTED || conn->state == BT_CONFIG)) {
238 		struct hci_dev *hdev = conn->hdev;
239 		struct hci_cp_read_clock_offset clkoff_cp;
240 
241 		clkoff_cp.handle = cpu_to_le16(conn->handle);
242 		hci_send_cmd(hdev, HCI_OP_READ_CLOCK_OFFSET, sizeof(clkoff_cp),
243 			     &clkoff_cp);
244 	}
245 
246 	return hci_abort_conn(conn, reason);
247 }
248 
hci_add_sco(struct hci_conn * conn,__u16 handle)249 static void hci_add_sco(struct hci_conn *conn, __u16 handle)
250 {
251 	struct hci_dev *hdev = conn->hdev;
252 	struct hci_cp_add_sco cp;
253 
254 	BT_DBG("hcon %p", conn);
255 
256 	conn->state = BT_CONNECT;
257 	conn->out = true;
258 
259 	conn->attempt++;
260 
261 	cp.handle   = cpu_to_le16(handle);
262 	cp.pkt_type = cpu_to_le16(conn->pkt_type);
263 
264 	hci_send_cmd(hdev, HCI_OP_ADD_SCO, sizeof(cp), &cp);
265 }
266 
hci_setup_sync(struct hci_conn * conn,__u16 handle)267 bool hci_setup_sync(struct hci_conn *conn, __u16 handle)
268 {
269 	struct hci_dev *hdev = conn->hdev;
270 	struct hci_cp_setup_sync_conn cp;
271 	const struct sco_param *param;
272 
273 	BT_DBG("hcon %p", conn);
274 
275 	conn->state = BT_CONNECT;
276 	conn->out = true;
277 
278 	conn->attempt++;
279 
280 	cp.handle   = cpu_to_le16(handle);
281 
282 	cp.tx_bandwidth   = cpu_to_le32(0x00001f40);
283 	cp.rx_bandwidth   = cpu_to_le32(0x00001f40);
284 	cp.voice_setting  = cpu_to_le16(conn->setting);
285 
286 	switch (conn->setting & SCO_AIRMODE_MASK) {
287 	case SCO_AIRMODE_TRANSP:
288 		if (conn->attempt > ARRAY_SIZE(esco_param_msbc))
289 			return false;
290 		param = &esco_param_msbc[conn->attempt - 1];
291 		break;
292 	case SCO_AIRMODE_CVSD:
293 		if (lmp_esco_capable(conn->link)) {
294 			if (conn->attempt > ARRAY_SIZE(esco_param_cvsd))
295 				return false;
296 			param = &esco_param_cvsd[conn->attempt - 1];
297 		} else {
298 			if (conn->attempt > ARRAY_SIZE(sco_param_cvsd))
299 				return false;
300 			param = &sco_param_cvsd[conn->attempt - 1];
301 		}
302 		break;
303 	default:
304 		return false;
305 	}
306 
307 	cp.retrans_effort = param->retrans_effort;
308 	cp.pkt_type = __cpu_to_le16(param->pkt_type);
309 	cp.max_latency = __cpu_to_le16(param->max_latency);
310 
311 	if (hci_send_cmd(hdev, HCI_OP_SETUP_SYNC_CONN, sizeof(cp), &cp) < 0)
312 		return false;
313 
314 	return true;
315 }
316 
hci_le_conn_update(struct hci_conn * conn,u16 min,u16 max,u16 latency,u16 to_multiplier)317 u8 hci_le_conn_update(struct hci_conn *conn, u16 min, u16 max, u16 latency,
318 		      u16 to_multiplier)
319 {
320 	struct hci_dev *hdev = conn->hdev;
321 	struct hci_conn_params *params;
322 	struct hci_cp_le_conn_update cp;
323 
324 	hci_dev_lock(hdev);
325 
326 	params = hci_conn_params_lookup(hdev, &conn->dst, conn->dst_type);
327 	if (params) {
328 		params->conn_min_interval = min;
329 		params->conn_max_interval = max;
330 		params->conn_latency = latency;
331 		params->supervision_timeout = to_multiplier;
332 	}
333 
334 	hci_dev_unlock(hdev);
335 
336 	memset(&cp, 0, sizeof(cp));
337 	cp.handle		= cpu_to_le16(conn->handle);
338 	cp.conn_interval_min	= cpu_to_le16(min);
339 	cp.conn_interval_max	= cpu_to_le16(max);
340 	cp.conn_latency		= cpu_to_le16(latency);
341 	cp.supervision_timeout	= cpu_to_le16(to_multiplier);
342 	cp.min_ce_len		= cpu_to_le16(0x0000);
343 	cp.max_ce_len		= cpu_to_le16(0x0000);
344 
345 	hci_send_cmd(hdev, HCI_OP_LE_CONN_UPDATE, sizeof(cp), &cp);
346 
347 	if (params)
348 		return 0x01;
349 
350 	return 0x00;
351 }
352 
hci_le_start_enc(struct hci_conn * conn,__le16 ediv,__le64 rand,__u8 ltk[16],__u8 key_size)353 void hci_le_start_enc(struct hci_conn *conn, __le16 ediv, __le64 rand,
354 		      __u8 ltk[16], __u8 key_size)
355 {
356 	struct hci_dev *hdev = conn->hdev;
357 	struct hci_cp_le_start_enc cp;
358 
359 	BT_DBG("hcon %p", conn);
360 
361 	memset(&cp, 0, sizeof(cp));
362 
363 	cp.handle = cpu_to_le16(conn->handle);
364 	cp.rand = rand;
365 	cp.ediv = ediv;
366 	memcpy(cp.ltk, ltk, key_size);
367 
368 	hci_send_cmd(hdev, HCI_OP_LE_START_ENC, sizeof(cp), &cp);
369 }
370 
371 /* Device _must_ be locked */
hci_sco_setup(struct hci_conn * conn,__u8 status)372 void hci_sco_setup(struct hci_conn *conn, __u8 status)
373 {
374 	struct hci_conn *sco = conn->link;
375 
376 	if (!sco)
377 		return;
378 
379 	BT_DBG("hcon %p", conn);
380 
381 	if (!status) {
382 		if (lmp_esco_capable(conn->hdev))
383 			hci_setup_sync(sco, conn->handle);
384 		else
385 			hci_add_sco(sco, conn->handle);
386 	} else {
387 		hci_connect_cfm(sco, status);
388 		hci_conn_del(sco);
389 	}
390 }
391 
hci_conn_timeout(struct work_struct * work)392 static void hci_conn_timeout(struct work_struct *work)
393 {
394 	struct hci_conn *conn = container_of(work, struct hci_conn,
395 					     disc_work.work);
396 	int refcnt = atomic_read(&conn->refcnt);
397 
398 	BT_DBG("hcon %p state %s", conn, state_to_string(conn->state));
399 
400 	WARN_ON(refcnt < 0);
401 
402 	/* FIXME: It was observed that in pairing failed scenario, refcnt
403 	 * drops below 0. Probably this is because l2cap_conn_del calls
404 	 * l2cap_chan_del for each channel, and inside l2cap_chan_del conn is
405 	 * dropped. After that loop hci_chan_del is called which also drops
406 	 * conn. For now make sure that ACL is alive if refcnt is higher then 0,
407 	 * otherwise drop it.
408 	 */
409 	if (refcnt > 0)
410 		return;
411 
412 	/* LE connections in scanning state need special handling */
413 	if (conn->state == BT_CONNECT && conn->type == LE_LINK &&
414 	    test_bit(HCI_CONN_SCANNING, &conn->flags)) {
415 		hci_connect_le_scan_remove(conn);
416 		return;
417 	}
418 
419 	hci_abort_conn(conn, hci_proto_disconn_ind(conn));
420 }
421 
422 /* Enter sniff mode */
hci_conn_idle(struct work_struct * work)423 static void hci_conn_idle(struct work_struct *work)
424 {
425 	struct hci_conn *conn = container_of(work, struct hci_conn,
426 					     idle_work.work);
427 	struct hci_dev *hdev = conn->hdev;
428 
429 	BT_DBG("hcon %p mode %d", conn, conn->mode);
430 
431 	if (!lmp_sniff_capable(hdev) || !lmp_sniff_capable(conn))
432 		return;
433 
434 	if (conn->mode != HCI_CM_ACTIVE || !(conn->link_policy & HCI_LP_SNIFF))
435 		return;
436 
437 	if (lmp_sniffsubr_capable(hdev) && lmp_sniffsubr_capable(conn)) {
438 		struct hci_cp_sniff_subrate cp;
439 		cp.handle             = cpu_to_le16(conn->handle);
440 		cp.max_latency        = cpu_to_le16(0);
441 		cp.min_remote_timeout = cpu_to_le16(0);
442 		cp.min_local_timeout  = cpu_to_le16(0);
443 		hci_send_cmd(hdev, HCI_OP_SNIFF_SUBRATE, sizeof(cp), &cp);
444 	}
445 
446 	if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->flags)) {
447 		struct hci_cp_sniff_mode cp;
448 		cp.handle       = cpu_to_le16(conn->handle);
449 		cp.max_interval = cpu_to_le16(hdev->sniff_max_interval);
450 		cp.min_interval = cpu_to_le16(hdev->sniff_min_interval);
451 		cp.attempt      = cpu_to_le16(4);
452 		cp.timeout      = cpu_to_le16(1);
453 		hci_send_cmd(hdev, HCI_OP_SNIFF_MODE, sizeof(cp), &cp);
454 	}
455 }
456 
hci_conn_auto_accept(struct work_struct * work)457 static void hci_conn_auto_accept(struct work_struct *work)
458 {
459 	struct hci_conn *conn = container_of(work, struct hci_conn,
460 					     auto_accept_work.work);
461 
462 	hci_send_cmd(conn->hdev, HCI_OP_USER_CONFIRM_REPLY, sizeof(conn->dst),
463 		     &conn->dst);
464 }
465 
le_conn_timeout(struct work_struct * work)466 static void le_conn_timeout(struct work_struct *work)
467 {
468 	struct hci_conn *conn = container_of(work, struct hci_conn,
469 					     le_conn_timeout.work);
470 	struct hci_dev *hdev = conn->hdev;
471 
472 	BT_DBG("");
473 
474 	/* We could end up here due to having done directed advertising,
475 	 * so clean up the state if necessary. This should however only
476 	 * happen with broken hardware or if low duty cycle was used
477 	 * (which doesn't have a timeout of its own).
478 	 */
479 	if (conn->role == HCI_ROLE_SLAVE) {
480 		u8 enable = 0x00;
481 		hci_send_cmd(hdev, HCI_OP_LE_SET_ADV_ENABLE, sizeof(enable),
482 			     &enable);
483 		hci_le_conn_failed(conn, HCI_ERROR_ADVERTISING_TIMEOUT);
484 		return;
485 	}
486 
487 	hci_abort_conn(conn, HCI_ERROR_REMOTE_USER_TERM);
488 }
489 
hci_conn_add(struct hci_dev * hdev,int type,bdaddr_t * dst,u8 role)490 struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst,
491 			      u8 role)
492 {
493 	struct hci_conn *conn;
494 
495 	BT_DBG("%s dst %pMR", hdev->name, dst);
496 
497 	conn = kzalloc(sizeof(*conn), GFP_KERNEL);
498 	if (!conn)
499 		return NULL;
500 
501 	bacpy(&conn->dst, dst);
502 	bacpy(&conn->src, &hdev->bdaddr);
503 	conn->hdev  = hdev;
504 	conn->type  = type;
505 	conn->role  = role;
506 	conn->mode  = HCI_CM_ACTIVE;
507 	conn->state = BT_OPEN;
508 	conn->auth_type = HCI_AT_GENERAL_BONDING;
509 	conn->io_capability = hdev->io_capability;
510 	conn->remote_auth = 0xff;
511 	conn->key_type = 0xff;
512 	conn->rssi = HCI_RSSI_INVALID;
513 	conn->tx_power = HCI_TX_POWER_INVALID;
514 	conn->max_tx_power = HCI_TX_POWER_INVALID;
515 
516 	set_bit(HCI_CONN_POWER_SAVE, &conn->flags);
517 	conn->disc_timeout = HCI_DISCONN_TIMEOUT;
518 
519 	if (conn->role == HCI_ROLE_MASTER)
520 		conn->out = true;
521 
522 	switch (type) {
523 	case ACL_LINK:
524 		conn->pkt_type = hdev->pkt_type & ACL_PTYPE_MASK;
525 		break;
526 	case LE_LINK:
527 		/* conn->src should reflect the local identity address */
528 		hci_copy_identity_address(hdev, &conn->src, &conn->src_type);
529 		break;
530 	case SCO_LINK:
531 		if (lmp_esco_capable(hdev))
532 			conn->pkt_type = (hdev->esco_type & SCO_ESCO_MASK) |
533 					(hdev->esco_type & EDR_ESCO_MASK);
534 		else
535 			conn->pkt_type = hdev->pkt_type & SCO_PTYPE_MASK;
536 		break;
537 	case ESCO_LINK:
538 		conn->pkt_type = hdev->esco_type & ~EDR_ESCO_MASK;
539 		break;
540 	}
541 
542 	skb_queue_head_init(&conn->data_q);
543 
544 	INIT_LIST_HEAD(&conn->chan_list);
545 
546 	INIT_DELAYED_WORK(&conn->disc_work, hci_conn_timeout);
547 	INIT_DELAYED_WORK(&conn->auto_accept_work, hci_conn_auto_accept);
548 	INIT_DELAYED_WORK(&conn->idle_work, hci_conn_idle);
549 	INIT_DELAYED_WORK(&conn->le_conn_timeout, le_conn_timeout);
550 	INIT_WORK(&conn->le_scan_cleanup, le_scan_cleanup);
551 
552 	atomic_set(&conn->refcnt, 0);
553 
554 	hci_dev_hold(hdev);
555 
556 	hci_conn_hash_add(hdev, conn);
557 	if (hdev->notify)
558 		hdev->notify(hdev, HCI_NOTIFY_CONN_ADD);
559 
560 	hci_conn_init_sysfs(conn);
561 
562 	return conn;
563 }
564 
hci_conn_del(struct hci_conn * conn)565 int hci_conn_del(struct hci_conn *conn)
566 {
567 	struct hci_dev *hdev = conn->hdev;
568 
569 	BT_DBG("%s hcon %p handle %d", hdev->name, conn, conn->handle);
570 
571 	cancel_delayed_work_sync(&conn->disc_work);
572 	cancel_delayed_work_sync(&conn->auto_accept_work);
573 	cancel_delayed_work_sync(&conn->idle_work);
574 
575 	if (conn->type == ACL_LINK) {
576 		struct hci_conn *sco = conn->link;
577 		if (sco)
578 			sco->link = NULL;
579 
580 		/* Unacked frames */
581 		hdev->acl_cnt += conn->sent;
582 	} else if (conn->type == LE_LINK) {
583 		cancel_delayed_work(&conn->le_conn_timeout);
584 
585 		if (hdev->le_pkts)
586 			hdev->le_cnt += conn->sent;
587 		else
588 			hdev->acl_cnt += conn->sent;
589 	} else {
590 		struct hci_conn *acl = conn->link;
591 		if (acl) {
592 			acl->link = NULL;
593 			hci_conn_drop(acl);
594 		}
595 	}
596 
597 	if (conn->amp_mgr)
598 		amp_mgr_put(conn->amp_mgr);
599 
600 	skb_queue_purge(&conn->data_q);
601 
602 	/* Remove the connection from the list and cleanup its remaining
603 	 * state. This is a separate function since for some cases like
604 	 * BT_CONNECT_SCAN we *only* want the cleanup part without the
605 	 * rest of hci_conn_del.
606 	 */
607 	hci_conn_cleanup(conn);
608 
609 	return 0;
610 }
611 
hci_get_route(bdaddr_t * dst,bdaddr_t * src)612 struct hci_dev *hci_get_route(bdaddr_t *dst, bdaddr_t *src)
613 {
614 	int use_src = bacmp(src, BDADDR_ANY);
615 	struct hci_dev *hdev = NULL, *d;
616 
617 	BT_DBG("%pMR -> %pMR", src, dst);
618 
619 	read_lock(&hci_dev_list_lock);
620 
621 	list_for_each_entry(d, &hci_dev_list, list) {
622 		if (!test_bit(HCI_UP, &d->flags) ||
623 		    hci_dev_test_flag(d, HCI_USER_CHANNEL) ||
624 		    d->dev_type != HCI_BREDR)
625 			continue;
626 
627 		/* Simple routing:
628 		 *   No source address - find interface with bdaddr != dst
629 		 *   Source address    - find interface with bdaddr == src
630 		 */
631 
632 		if (use_src) {
633 			if (!bacmp(&d->bdaddr, src)) {
634 				hdev = d; break;
635 			}
636 		} else {
637 			if (bacmp(&d->bdaddr, dst)) {
638 				hdev = d; break;
639 			}
640 		}
641 	}
642 
643 	if (hdev)
644 		hdev = hci_dev_hold(hdev);
645 
646 	read_unlock(&hci_dev_list_lock);
647 	return hdev;
648 }
649 EXPORT_SYMBOL(hci_get_route);
650 
651 /* This function requires the caller holds hdev->lock */
hci_le_conn_failed(struct hci_conn * conn,u8 status)652 void hci_le_conn_failed(struct hci_conn *conn, u8 status)
653 {
654 	struct hci_dev *hdev = conn->hdev;
655 	struct hci_conn_params *params;
656 
657 	params = hci_pend_le_action_lookup(&hdev->pend_le_conns, &conn->dst,
658 					   conn->dst_type);
659 	if (params && params->conn) {
660 		hci_conn_drop(params->conn);
661 		hci_conn_put(params->conn);
662 		params->conn = NULL;
663 	}
664 
665 	conn->state = BT_CLOSED;
666 
667 	mgmt_connect_failed(hdev, &conn->dst, conn->type, conn->dst_type,
668 			    status);
669 
670 	hci_connect_cfm(conn, status);
671 
672 	hci_conn_del(conn);
673 
674 	/* Since we may have temporarily stopped the background scanning in
675 	 * favor of connection establishment, we should restart it.
676 	 */
677 	hci_update_background_scan(hdev);
678 
679 	/* Re-enable advertising in case this was a failed connection
680 	 * attempt as a peripheral.
681 	 */
682 	mgmt_reenable_advertising(hdev);
683 }
684 
create_le_conn_complete(struct hci_dev * hdev,u8 status,u16 opcode)685 static void create_le_conn_complete(struct hci_dev *hdev, u8 status, u16 opcode)
686 {
687 	struct hci_conn *conn;
688 
689 	hci_dev_lock(hdev);
690 
691 	conn = hci_lookup_le_connect(hdev);
692 
693 	if (!status) {
694 		hci_connect_le_scan_cleanup(conn);
695 		goto done;
696 	}
697 
698 	BT_ERR("HCI request failed to create LE connection: status 0x%2.2x",
699 	       status);
700 
701 	if (!conn)
702 		goto done;
703 
704 	hci_le_conn_failed(conn, status);
705 
706 done:
707 	hci_dev_unlock(hdev);
708 }
709 
hci_req_add_le_create_conn(struct hci_request * req,struct hci_conn * conn,bdaddr_t * direct_rpa)710 static void hci_req_add_le_create_conn(struct hci_request *req,
711 				       struct hci_conn *conn,
712 				       bdaddr_t *direct_rpa)
713 {
714 	struct hci_cp_le_create_conn cp;
715 	struct hci_dev *hdev = conn->hdev;
716 	u8 own_addr_type;
717 
718 	memset(&cp, 0, sizeof(cp));
719 
720 	/* If direct address was provided we use it instead of current
721 	 * address.
722 	 */
723 	if (direct_rpa) {
724 		if (bacmp(&req->hdev->random_addr, direct_rpa))
725 			hci_req_add(req, HCI_OP_LE_SET_RANDOM_ADDR, 6,
726 								direct_rpa);
727 
728 		/* direct address is always RPA */
729 		own_addr_type = ADDR_LE_DEV_RANDOM;
730 	} else {
731 		/* Update random address, but set require_privacy to false so
732 		 * that we never connect with an non-resolvable address.
733 		 */
734 		if (hci_update_random_address(req, false, &own_addr_type))
735 			return;
736 	}
737 
738 	/* Set window to be the same value as the interval to enable
739 	 * continuous scanning.
740 	 */
741 	cp.scan_interval = cpu_to_le16(hdev->le_scan_interval);
742 	cp.scan_window = cp.scan_interval;
743 
744 	bacpy(&cp.peer_addr, &conn->dst);
745 	cp.peer_addr_type = conn->dst_type;
746 	cp.own_address_type = own_addr_type;
747 	cp.conn_interval_min = cpu_to_le16(conn->le_conn_min_interval);
748 	cp.conn_interval_max = cpu_to_le16(conn->le_conn_max_interval);
749 	cp.conn_latency = cpu_to_le16(conn->le_conn_latency);
750 	cp.supervision_timeout = cpu_to_le16(conn->le_supv_timeout);
751 	cp.min_ce_len = cpu_to_le16(0x0000);
752 	cp.max_ce_len = cpu_to_le16(0x0000);
753 
754 	hci_req_add(req, HCI_OP_LE_CREATE_CONN, sizeof(cp), &cp);
755 
756 	conn->state = BT_CONNECT;
757 	clear_bit(HCI_CONN_SCANNING, &conn->flags);
758 }
759 
hci_req_directed_advertising(struct hci_request * req,struct hci_conn * conn)760 static void hci_req_directed_advertising(struct hci_request *req,
761 					 struct hci_conn *conn)
762 {
763 	struct hci_dev *hdev = req->hdev;
764 	struct hci_cp_le_set_adv_param cp;
765 	u8 own_addr_type;
766 	u8 enable;
767 
768 	/* Clear the HCI_LE_ADV bit temporarily so that the
769 	 * hci_update_random_address knows that it's safe to go ahead
770 	 * and write a new random address. The flag will be set back on
771 	 * as soon as the SET_ADV_ENABLE HCI command completes.
772 	 */
773 	hci_dev_clear_flag(hdev, HCI_LE_ADV);
774 
775 	/* Set require_privacy to false so that the remote device has a
776 	 * chance of identifying us.
777 	 */
778 	if (hci_update_random_address(req, false, &own_addr_type) < 0)
779 		return;
780 
781 	memset(&cp, 0, sizeof(cp));
782 	cp.type = LE_ADV_DIRECT_IND;
783 	cp.own_address_type = own_addr_type;
784 	cp.direct_addr_type = conn->dst_type;
785 	bacpy(&cp.direct_addr, &conn->dst);
786 	cp.channel_map = hdev->le_adv_channel_map;
787 
788 	hci_req_add(req, HCI_OP_LE_SET_ADV_PARAM, sizeof(cp), &cp);
789 
790 	enable = 0x01;
791 	hci_req_add(req, HCI_OP_LE_SET_ADV_ENABLE, sizeof(enable), &enable);
792 
793 	conn->state = BT_CONNECT;
794 }
795 
hci_connect_le(struct hci_dev * hdev,bdaddr_t * dst,u8 dst_type,u8 sec_level,u16 conn_timeout,u8 role,bdaddr_t * direct_rpa)796 struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
797 				u8 dst_type, u8 sec_level, u16 conn_timeout,
798 				u8 role, bdaddr_t *direct_rpa)
799 {
800 	struct hci_conn_params *params;
801 	struct hci_conn *conn, *conn_unfinished;
802 	struct smp_irk *irk;
803 	struct hci_request req;
804 	int err;
805 
806 	/* Let's make sure that le is enabled.*/
807 	if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) {
808 		if (lmp_le_capable(hdev))
809 			return ERR_PTR(-ECONNREFUSED);
810 
811 		return ERR_PTR(-EOPNOTSUPP);
812 	}
813 
814 	/* Some devices send ATT messages as soon as the physical link is
815 	 * established. To be able to handle these ATT messages, the user-
816 	 * space first establishes the connection and then starts the pairing
817 	 * process.
818 	 *
819 	 * So if a hci_conn object already exists for the following connection
820 	 * attempt, we simply update pending_sec_level and auth_type fields
821 	 * and return the object found.
822 	 */
823 	conn = hci_conn_hash_lookup_le(hdev, dst, dst_type);
824 	conn_unfinished = NULL;
825 	if (conn) {
826 		if (conn->state == BT_CONNECT &&
827 		    test_bit(HCI_CONN_SCANNING, &conn->flags)) {
828 			BT_DBG("will continue unfinished conn %pMR", dst);
829 			conn_unfinished = conn;
830 		} else {
831 			if (conn->pending_sec_level < sec_level)
832 				conn->pending_sec_level = sec_level;
833 			goto done;
834 		}
835 	}
836 
837 	/* Since the controller supports only one LE connection attempt at a
838 	 * time, we return -EBUSY if there is any connection attempt running.
839 	 */
840 	if (hci_lookup_le_connect(hdev))
841 		return ERR_PTR(-EBUSY);
842 
843 	/* When given an identity address with existing identity
844 	 * resolving key, the connection needs to be established
845 	 * to a resolvable random address.
846 	 *
847 	 * Storing the resolvable random address is required here
848 	 * to handle connection failures. The address will later
849 	 * be resolved back into the original identity address
850 	 * from the connect request.
851 	 */
852 	irk = hci_find_irk_by_addr(hdev, dst, dst_type);
853 	if (irk && bacmp(&irk->rpa, BDADDR_ANY)) {
854 		dst = &irk->rpa;
855 		dst_type = ADDR_LE_DEV_RANDOM;
856 	}
857 
858 	if (conn_unfinished) {
859 		conn = conn_unfinished;
860 		bacpy(&conn->dst, dst);
861 	} else {
862 		conn = hci_conn_add(hdev, LE_LINK, dst, role);
863 	}
864 
865 	if (!conn)
866 		return ERR_PTR(-ENOMEM);
867 
868 	conn->dst_type = dst_type;
869 	conn->sec_level = BT_SECURITY_LOW;
870 	conn->conn_timeout = conn_timeout;
871 
872 	if (!conn_unfinished)
873 		conn->pending_sec_level = sec_level;
874 
875 	hci_req_init(&req, hdev);
876 
877 	/* Disable advertising if we're active. For master role
878 	 * connections most controllers will refuse to connect if
879 	 * advertising is enabled, and for slave role connections we
880 	 * anyway have to disable it in order to start directed
881 	 * advertising.
882 	 */
883 	if (hci_dev_test_flag(hdev, HCI_LE_ADV)) {
884 		u8 enable = 0x00;
885 		hci_req_add(&req, HCI_OP_LE_SET_ADV_ENABLE, sizeof(enable),
886 			    &enable);
887 	}
888 
889 	/* If requested to connect as slave use directed advertising */
890 	if (conn->role == HCI_ROLE_SLAVE) {
891 		/* If we're active scanning most controllers are unable
892 		 * to initiate advertising. Simply reject the attempt.
893 		 */
894 		if (hci_dev_test_flag(hdev, HCI_LE_SCAN) &&
895 		    hdev->le_scan_type == LE_SCAN_ACTIVE) {
896 			skb_queue_purge(&req.cmd_q);
897 			hci_conn_del(conn);
898 			return ERR_PTR(-EBUSY);
899 		}
900 
901 		hci_req_directed_advertising(&req, conn);
902 		goto create_conn;
903 	}
904 
905 	params = hci_conn_params_lookup(hdev, &conn->dst, conn->dst_type);
906 	if (params) {
907 		conn->le_conn_min_interval = params->conn_min_interval;
908 		conn->le_conn_max_interval = params->conn_max_interval;
909 		conn->le_conn_latency = params->conn_latency;
910 		conn->le_supv_timeout = params->supervision_timeout;
911 	} else {
912 		conn->le_conn_min_interval = hdev->le_conn_min_interval;
913 		conn->le_conn_max_interval = hdev->le_conn_max_interval;
914 		conn->le_conn_latency = hdev->le_conn_latency;
915 		conn->le_supv_timeout = hdev->le_supv_timeout;
916 	}
917 
918 	/* If controller is scanning, we stop it since some controllers are
919 	 * not able to scan and connect at the same time. Also set the
920 	 * HCI_LE_SCAN_INTERRUPTED flag so that the command complete
921 	 * handler for scan disabling knows to set the correct discovery
922 	 * state.
923 	 */
924 	if (hci_dev_test_flag(hdev, HCI_LE_SCAN)) {
925 		hci_req_add_le_scan_disable(&req);
926 		hci_dev_set_flag(hdev, HCI_LE_SCAN_INTERRUPTED);
927 	}
928 
929 	hci_req_add_le_create_conn(&req, conn, direct_rpa);
930 
931 create_conn:
932 	err = hci_req_run(&req, create_le_conn_complete);
933 	if (err) {
934 		hci_conn_del(conn);
935 		return ERR_PTR(err);
936 	}
937 
938 done:
939 	/* If this is continuation of connect started by hci_connect_le_scan,
940 	 * it already called hci_conn_hold and calling it again would mess the
941 	 * counter.
942 	 */
943 	if (!conn_unfinished)
944 		hci_conn_hold(conn);
945 
946 	return conn;
947 }
948 
hci_connect_le_scan_complete(struct hci_dev * hdev,u8 status,u16 opcode)949 static void hci_connect_le_scan_complete(struct hci_dev *hdev, u8 status,
950 					 u16 opcode)
951 {
952 	struct hci_conn *conn;
953 
954 	if (!status)
955 		return;
956 
957 	BT_ERR("Failed to add device to auto conn whitelist: status 0x%2.2x",
958 	       status);
959 
960 	hci_dev_lock(hdev);
961 
962 	conn = hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT);
963 	if (conn)
964 		hci_le_conn_failed(conn, status);
965 
966 	hci_dev_unlock(hdev);
967 }
968 
is_connected(struct hci_dev * hdev,bdaddr_t * addr,u8 type)969 static bool is_connected(struct hci_dev *hdev, bdaddr_t *addr, u8 type)
970 {
971 	struct hci_conn *conn;
972 
973 	conn = hci_conn_hash_lookup_le(hdev, addr, type);
974 	if (!conn)
975 		return false;
976 
977 	if (conn->state != BT_CONNECTED)
978 		return false;
979 
980 	return true;
981 }
982 
983 /* This function requires the caller holds hdev->lock */
hci_explicit_conn_params_set(struct hci_request * req,bdaddr_t * addr,u8 addr_type)984 static int hci_explicit_conn_params_set(struct hci_request *req,
985 					bdaddr_t *addr, u8 addr_type)
986 {
987 	struct hci_dev *hdev = req->hdev;
988 	struct hci_conn_params *params;
989 
990 	if (is_connected(hdev, addr, addr_type))
991 		return -EISCONN;
992 
993 	params = hci_conn_params_lookup(hdev, addr, addr_type);
994 	if (!params) {
995 		params = hci_conn_params_add(hdev, addr, addr_type);
996 		if (!params)
997 			return -ENOMEM;
998 
999 		/* If we created new params, mark them to be deleted in
1000 		 * hci_connect_le_scan_cleanup. It's different case than
1001 		 * existing disabled params, those will stay after cleanup.
1002 		 */
1003 		params->auto_connect = HCI_AUTO_CONN_EXPLICIT;
1004 	}
1005 
1006 	/* We're trying to connect, so make sure params are at pend_le_conns */
1007 	if (params->auto_connect == HCI_AUTO_CONN_DISABLED ||
1008 	    params->auto_connect == HCI_AUTO_CONN_REPORT ||
1009 	    params->auto_connect == HCI_AUTO_CONN_EXPLICIT) {
1010 		list_del_init(&params->action);
1011 		list_add(&params->action, &hdev->pend_le_conns);
1012 	}
1013 
1014 	params->explicit_connect = true;
1015 	__hci_update_background_scan(req);
1016 
1017 	BT_DBG("addr %pMR (type %u) auto_connect %u", addr, addr_type,
1018 	       params->auto_connect);
1019 
1020 	return 0;
1021 }
1022 
1023 /* This function requires the caller holds hdev->lock */
hci_connect_le_scan(struct hci_dev * hdev,bdaddr_t * dst,u8 dst_type,u8 sec_level,u16 conn_timeout,u8 role)1024 struct hci_conn *hci_connect_le_scan(struct hci_dev *hdev, bdaddr_t *dst,
1025 				     u8 dst_type, u8 sec_level,
1026 				     u16 conn_timeout, u8 role)
1027 {
1028 	struct hci_conn *conn;
1029 	struct hci_request req;
1030 	int err;
1031 
1032 	/* Let's make sure that le is enabled.*/
1033 	if (!hci_dev_test_flag(hdev, HCI_LE_ENABLED)) {
1034 		if (lmp_le_capable(hdev))
1035 			return ERR_PTR(-ECONNREFUSED);
1036 
1037 		return ERR_PTR(-EOPNOTSUPP);
1038 	}
1039 
1040 	/* Some devices send ATT messages as soon as the physical link is
1041 	 * established. To be able to handle these ATT messages, the user-
1042 	 * space first establishes the connection and then starts the pairing
1043 	 * process.
1044 	 *
1045 	 * So if a hci_conn object already exists for the following connection
1046 	 * attempt, we simply update pending_sec_level and auth_type fields
1047 	 * and return the object found.
1048 	 */
1049 	conn = hci_conn_hash_lookup_le(hdev, dst, dst_type);
1050 	if (conn) {
1051 		if (conn->pending_sec_level < sec_level)
1052 			conn->pending_sec_level = sec_level;
1053 		goto done;
1054 	}
1055 
1056 	BT_DBG("requesting refresh of dst_addr");
1057 
1058 	conn = hci_conn_add(hdev, LE_LINK, dst, role);
1059 	if (!conn)
1060 		return ERR_PTR(-ENOMEM);
1061 
1062 	hci_req_init(&req, hdev);
1063 
1064 	if (hci_explicit_conn_params_set(&req, dst, dst_type) < 0)
1065 		return ERR_PTR(-EBUSY);
1066 
1067 	conn->state = BT_CONNECT;
1068 	set_bit(HCI_CONN_SCANNING, &conn->flags);
1069 
1070 	err = hci_req_run(&req, hci_connect_le_scan_complete);
1071 	if (err && err != -ENODATA) {
1072 		hci_conn_del(conn);
1073 		return ERR_PTR(err);
1074 	}
1075 
1076 	conn->dst_type = dst_type;
1077 	conn->sec_level = BT_SECURITY_LOW;
1078 	conn->pending_sec_level = sec_level;
1079 	conn->conn_timeout = conn_timeout;
1080 
1081 done:
1082 	hci_conn_hold(conn);
1083 	return conn;
1084 }
1085 
hci_connect_acl(struct hci_dev * hdev,bdaddr_t * dst,u8 sec_level,u8 auth_type)1086 struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
1087 				 u8 sec_level, u8 auth_type)
1088 {
1089 	struct hci_conn *acl;
1090 
1091 	if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED)) {
1092 		if (lmp_bredr_capable(hdev))
1093 			return ERR_PTR(-ECONNREFUSED);
1094 
1095 		return ERR_PTR(-EOPNOTSUPP);
1096 	}
1097 
1098 	acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
1099 	if (!acl) {
1100 		acl = hci_conn_add(hdev, ACL_LINK, dst, HCI_ROLE_MASTER);
1101 		if (!acl)
1102 			return ERR_PTR(-ENOMEM);
1103 	}
1104 
1105 	hci_conn_hold(acl);
1106 
1107 	if (acl->state == BT_OPEN || acl->state == BT_CLOSED) {
1108 		acl->sec_level = BT_SECURITY_LOW;
1109 		acl->pending_sec_level = sec_level;
1110 		acl->auth_type = auth_type;
1111 		hci_acl_create_connection(acl);
1112 	}
1113 
1114 	return acl;
1115 }
1116 
hci_connect_sco(struct hci_dev * hdev,int type,bdaddr_t * dst,__u16 setting)1117 struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type, bdaddr_t *dst,
1118 				 __u16 setting)
1119 {
1120 	struct hci_conn *acl;
1121 	struct hci_conn *sco;
1122 
1123 	acl = hci_connect_acl(hdev, dst, BT_SECURITY_LOW, HCI_AT_NO_BONDING);
1124 	if (IS_ERR(acl))
1125 		return acl;
1126 
1127 	sco = hci_conn_hash_lookup_ba(hdev, type, dst);
1128 	if (!sco) {
1129 		sco = hci_conn_add(hdev, type, dst, HCI_ROLE_MASTER);
1130 		if (!sco) {
1131 			hci_conn_drop(acl);
1132 			return ERR_PTR(-ENOMEM);
1133 		}
1134 	}
1135 
1136 	acl->link = sco;
1137 	sco->link = acl;
1138 
1139 	hci_conn_hold(sco);
1140 
1141 	sco->setting = setting;
1142 
1143 	if (acl->state == BT_CONNECTED &&
1144 	    (sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
1145 		set_bit(HCI_CONN_POWER_SAVE, &acl->flags);
1146 		hci_conn_enter_active_mode(acl, BT_POWER_FORCE_ACTIVE_ON);
1147 
1148 		if (test_bit(HCI_CONN_MODE_CHANGE_PEND, &acl->flags)) {
1149 			/* defer SCO setup until mode change completed */
1150 			set_bit(HCI_CONN_SCO_SETUP_PEND, &acl->flags);
1151 			return sco;
1152 		}
1153 
1154 		hci_sco_setup(acl, 0x00);
1155 	}
1156 
1157 	return sco;
1158 }
1159 
1160 /* Check link security requirement */
hci_conn_check_link_mode(struct hci_conn * conn)1161 int hci_conn_check_link_mode(struct hci_conn *conn)
1162 {
1163 	BT_DBG("hcon %p", conn);
1164 
1165 	/* In Secure Connections Only mode, it is required that Secure
1166 	 * Connections is used and the link is encrypted with AES-CCM
1167 	 * using a P-256 authenticated combination key.
1168 	 */
1169 	if (hci_dev_test_flag(conn->hdev, HCI_SC_ONLY)) {
1170 		if (!hci_conn_sc_enabled(conn) ||
1171 		    !test_bit(HCI_CONN_AES_CCM, &conn->flags) ||
1172 		    conn->key_type != HCI_LK_AUTH_COMBINATION_P256)
1173 			return 0;
1174 	}
1175 
1176 	 /* AES encryption is required for Level 4:
1177 	  *
1178 	  * BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 3, Part C
1179 	  * page 1319:
1180 	  *
1181 	  * 128-bit equivalent strength for link and encryption keys
1182 	  * required using FIPS approved algorithms (E0 not allowed,
1183 	  * SAFER+ not allowed, and P-192 not allowed; encryption key
1184 	  * not shortened)
1185 	  */
1186 	if (conn->sec_level == BT_SECURITY_FIPS &&
1187 	    !test_bit(HCI_CONN_AES_CCM, &conn->flags)) {
1188 		bt_dev_err(conn->hdev,
1189 			   "Invalid security: Missing AES-CCM usage");
1190 		return 0;
1191 	}
1192 
1193 	if (hci_conn_ssp_enabled(conn) &&
1194 	    !test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1195 		return 0;
1196 
1197 	return 1;
1198 }
1199 
1200 /* Authenticate remote device */
hci_conn_auth(struct hci_conn * conn,__u8 sec_level,__u8 auth_type)1201 static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
1202 {
1203 	BT_DBG("hcon %p", conn);
1204 
1205 	if (conn->pending_sec_level > sec_level)
1206 		sec_level = conn->pending_sec_level;
1207 
1208 	if (sec_level > conn->sec_level)
1209 		conn->pending_sec_level = sec_level;
1210 	else if (test_bit(HCI_CONN_AUTH, &conn->flags))
1211 		return 1;
1212 
1213 	/* Make sure we preserve an existing MITM requirement*/
1214 	auth_type |= (conn->auth_type & 0x01);
1215 
1216 	conn->auth_type = auth_type;
1217 
1218 	if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->flags)) {
1219 		struct hci_cp_auth_requested cp;
1220 
1221 		cp.handle = cpu_to_le16(conn->handle);
1222 		hci_send_cmd(conn->hdev, HCI_OP_AUTH_REQUESTED,
1223 			     sizeof(cp), &cp);
1224 
1225 		/* If we're already encrypted set the REAUTH_PEND flag,
1226 		 * otherwise set the ENCRYPT_PEND.
1227 		 */
1228 		if (test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1229 			set_bit(HCI_CONN_REAUTH_PEND, &conn->flags);
1230 		else
1231 			set_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags);
1232 	}
1233 
1234 	return 0;
1235 }
1236 
1237 /* Encrypt the the link */
hci_conn_encrypt(struct hci_conn * conn)1238 static void hci_conn_encrypt(struct hci_conn *conn)
1239 {
1240 	BT_DBG("hcon %p", conn);
1241 
1242 	if (!test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags)) {
1243 		struct hci_cp_set_conn_encrypt cp;
1244 		cp.handle  = cpu_to_le16(conn->handle);
1245 		cp.encrypt = 0x01;
1246 		hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT, sizeof(cp),
1247 			     &cp);
1248 	}
1249 }
1250 
1251 /* Enable security */
hci_conn_security(struct hci_conn * conn,__u8 sec_level,__u8 auth_type,bool initiator)1252 int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type,
1253 		      bool initiator)
1254 {
1255 	BT_DBG("hcon %p", conn);
1256 
1257 	if (conn->type == LE_LINK)
1258 		return smp_conn_security(conn, sec_level);
1259 
1260 	/* For sdp we don't need the link key. */
1261 	if (sec_level == BT_SECURITY_SDP)
1262 		return 1;
1263 
1264 	/* For non 2.1 devices and low security level we don't need the link
1265 	   key. */
1266 	if (sec_level == BT_SECURITY_LOW && !hci_conn_ssp_enabled(conn))
1267 		return 1;
1268 
1269 	/* For other security levels we need the link key. */
1270 	if (!test_bit(HCI_CONN_AUTH, &conn->flags))
1271 		goto auth;
1272 
1273 	/* An authenticated FIPS approved combination key has sufficient
1274 	 * security for security level 4. */
1275 	if (conn->key_type == HCI_LK_AUTH_COMBINATION_P256 &&
1276 	    sec_level == BT_SECURITY_FIPS)
1277 		goto encrypt;
1278 
1279 	/* An authenticated combination key has sufficient security for
1280 	   security level 3. */
1281 	if ((conn->key_type == HCI_LK_AUTH_COMBINATION_P192 ||
1282 	     conn->key_type == HCI_LK_AUTH_COMBINATION_P256) &&
1283 	    sec_level == BT_SECURITY_HIGH)
1284 		goto encrypt;
1285 
1286 	/* An unauthenticated combination key has sufficient security for
1287 	   security level 1 and 2. */
1288 	if ((conn->key_type == HCI_LK_UNAUTH_COMBINATION_P192 ||
1289 	     conn->key_type == HCI_LK_UNAUTH_COMBINATION_P256) &&
1290 	    (sec_level == BT_SECURITY_MEDIUM || sec_level == BT_SECURITY_LOW))
1291 		goto encrypt;
1292 
1293 	/* A combination key has always sufficient security for the security
1294 	   levels 1 or 2. High security level requires the combination key
1295 	   is generated using maximum PIN code length (16).
1296 	   For pre 2.1 units. */
1297 	if (conn->key_type == HCI_LK_COMBINATION &&
1298 	    (sec_level == BT_SECURITY_MEDIUM || sec_level == BT_SECURITY_LOW ||
1299 	     conn->pin_length == 16))
1300 		goto encrypt;
1301 
1302 auth:
1303 	if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags))
1304 		return 0;
1305 
1306 	if (initiator)
1307 		set_bit(HCI_CONN_AUTH_INITIATOR, &conn->flags);
1308 
1309 	if (!hci_conn_auth(conn, sec_level, auth_type))
1310 		return 0;
1311 
1312 encrypt:
1313 	if (test_bit(HCI_CONN_ENCRYPT, &conn->flags)) {
1314 		/* Ensure that the encryption key size has been read,
1315 		 * otherwise stall the upper layer responses.
1316 		 */
1317 		if (!conn->enc_key_size)
1318 			return 0;
1319 
1320 		/* Nothing else needed, all requirements are met */
1321 		return 1;
1322 	}
1323 
1324 	hci_conn_encrypt(conn);
1325 	return 0;
1326 }
1327 EXPORT_SYMBOL(hci_conn_security);
1328 
1329 /* Check secure link requirement */
hci_conn_check_secure(struct hci_conn * conn,__u8 sec_level)1330 int hci_conn_check_secure(struct hci_conn *conn, __u8 sec_level)
1331 {
1332 	BT_DBG("hcon %p", conn);
1333 
1334 	/* Accept if non-secure or higher security level is required */
1335 	if (sec_level != BT_SECURITY_HIGH && sec_level != BT_SECURITY_FIPS)
1336 		return 1;
1337 
1338 	/* Accept if secure or higher security level is already present */
1339 	if (conn->sec_level == BT_SECURITY_HIGH ||
1340 	    conn->sec_level == BT_SECURITY_FIPS)
1341 		return 1;
1342 
1343 	/* Reject not secure link */
1344 	return 0;
1345 }
1346 EXPORT_SYMBOL(hci_conn_check_secure);
1347 
1348 /* Switch role */
hci_conn_switch_role(struct hci_conn * conn,__u8 role)1349 int hci_conn_switch_role(struct hci_conn *conn, __u8 role)
1350 {
1351 	BT_DBG("hcon %p", conn);
1352 
1353 	if (role == conn->role)
1354 		return 1;
1355 
1356 	if (!test_and_set_bit(HCI_CONN_RSWITCH_PEND, &conn->flags)) {
1357 		struct hci_cp_switch_role cp;
1358 		bacpy(&cp.bdaddr, &conn->dst);
1359 		cp.role = role;
1360 		hci_send_cmd(conn->hdev, HCI_OP_SWITCH_ROLE, sizeof(cp), &cp);
1361 	}
1362 
1363 	return 0;
1364 }
1365 EXPORT_SYMBOL(hci_conn_switch_role);
1366 
1367 /* Enter active mode */
hci_conn_enter_active_mode(struct hci_conn * conn,__u8 force_active)1368 void hci_conn_enter_active_mode(struct hci_conn *conn, __u8 force_active)
1369 {
1370 	struct hci_dev *hdev = conn->hdev;
1371 
1372 	BT_DBG("hcon %p mode %d", conn, conn->mode);
1373 
1374 	if (conn->mode != HCI_CM_SNIFF)
1375 		goto timer;
1376 
1377 	if (!test_bit(HCI_CONN_POWER_SAVE, &conn->flags) && !force_active)
1378 		goto timer;
1379 
1380 	if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->flags)) {
1381 		struct hci_cp_exit_sniff_mode cp;
1382 		cp.handle = cpu_to_le16(conn->handle);
1383 		hci_send_cmd(hdev, HCI_OP_EXIT_SNIFF_MODE, sizeof(cp), &cp);
1384 	}
1385 
1386 timer:
1387 	if (hdev->idle_timeout > 0)
1388 		queue_delayed_work(hdev->workqueue, &conn->idle_work,
1389 				   msecs_to_jiffies(hdev->idle_timeout));
1390 }
1391 
1392 /* Drop all connection on the device */
hci_conn_hash_flush(struct hci_dev * hdev)1393 void hci_conn_hash_flush(struct hci_dev *hdev)
1394 {
1395 	struct hci_conn_hash *h = &hdev->conn_hash;
1396 	struct hci_conn *c, *n;
1397 
1398 	BT_DBG("hdev %s", hdev->name);
1399 
1400 	list_for_each_entry_safe(c, n, &h->list, list) {
1401 		c->state = BT_CLOSED;
1402 
1403 		hci_disconn_cfm(c, HCI_ERROR_LOCAL_HOST_TERM);
1404 		hci_conn_del(c);
1405 	}
1406 }
1407 
1408 /* Check pending connect attempts */
hci_conn_check_pending(struct hci_dev * hdev)1409 void hci_conn_check_pending(struct hci_dev *hdev)
1410 {
1411 	struct hci_conn *conn;
1412 
1413 	BT_DBG("hdev %s", hdev->name);
1414 
1415 	hci_dev_lock(hdev);
1416 
1417 	conn = hci_conn_hash_lookup_state(hdev, ACL_LINK, BT_CONNECT2);
1418 	if (conn)
1419 		hci_acl_create_connection(conn);
1420 
1421 	hci_dev_unlock(hdev);
1422 }
1423 
get_link_mode(struct hci_conn * conn)1424 static u32 get_link_mode(struct hci_conn *conn)
1425 {
1426 	u32 link_mode = 0;
1427 
1428 	if (conn->role == HCI_ROLE_MASTER)
1429 		link_mode |= HCI_LM_MASTER;
1430 
1431 	if (test_bit(HCI_CONN_ENCRYPT, &conn->flags))
1432 		link_mode |= HCI_LM_ENCRYPT;
1433 
1434 	if (test_bit(HCI_CONN_AUTH, &conn->flags))
1435 		link_mode |= HCI_LM_AUTH;
1436 
1437 	if (test_bit(HCI_CONN_SECURE, &conn->flags))
1438 		link_mode |= HCI_LM_SECURE;
1439 
1440 	if (test_bit(HCI_CONN_FIPS, &conn->flags))
1441 		link_mode |= HCI_LM_FIPS;
1442 
1443 	return link_mode;
1444 }
1445 
hci_get_conn_list(void __user * arg)1446 int hci_get_conn_list(void __user *arg)
1447 {
1448 	struct hci_conn *c;
1449 	struct hci_conn_list_req req, *cl;
1450 	struct hci_conn_info *ci;
1451 	struct hci_dev *hdev;
1452 	int n = 0, size, err;
1453 
1454 	if (copy_from_user(&req, arg, sizeof(req)))
1455 		return -EFAULT;
1456 
1457 	if (!req.conn_num || req.conn_num > (PAGE_SIZE * 2) / sizeof(*ci))
1458 		return -EINVAL;
1459 
1460 	size = sizeof(req) + req.conn_num * sizeof(*ci);
1461 
1462 	cl = kmalloc(size, GFP_KERNEL);
1463 	if (!cl)
1464 		return -ENOMEM;
1465 
1466 	hdev = hci_dev_get(req.dev_id);
1467 	if (!hdev) {
1468 		kfree(cl);
1469 		return -ENODEV;
1470 	}
1471 
1472 	ci = cl->conn_info;
1473 
1474 	hci_dev_lock(hdev);
1475 	list_for_each_entry(c, &hdev->conn_hash.list, list) {
1476 		bacpy(&(ci + n)->bdaddr, &c->dst);
1477 		(ci + n)->handle = c->handle;
1478 		(ci + n)->type  = c->type;
1479 		(ci + n)->out   = c->out;
1480 		(ci + n)->state = c->state;
1481 		(ci + n)->link_mode = get_link_mode(c);
1482 		if (++n >= req.conn_num)
1483 			break;
1484 	}
1485 	hci_dev_unlock(hdev);
1486 
1487 	cl->dev_id = hdev->id;
1488 	cl->conn_num = n;
1489 	size = sizeof(req) + n * sizeof(*ci);
1490 
1491 	hci_dev_put(hdev);
1492 
1493 	err = copy_to_user(arg, cl, size);
1494 	kfree(cl);
1495 
1496 	return err ? -EFAULT : 0;
1497 }
1498 
hci_get_conn_info(struct hci_dev * hdev,void __user * arg)1499 int hci_get_conn_info(struct hci_dev *hdev, void __user *arg)
1500 {
1501 	struct hci_conn_info_req req;
1502 	struct hci_conn_info ci;
1503 	struct hci_conn *conn;
1504 	char __user *ptr = arg + sizeof(req);
1505 
1506 	if (copy_from_user(&req, arg, sizeof(req)))
1507 		return -EFAULT;
1508 
1509 	hci_dev_lock(hdev);
1510 	conn = hci_conn_hash_lookup_ba(hdev, req.type, &req.bdaddr);
1511 	if (conn) {
1512 		bacpy(&ci.bdaddr, &conn->dst);
1513 		ci.handle = conn->handle;
1514 		ci.type  = conn->type;
1515 		ci.out   = conn->out;
1516 		ci.state = conn->state;
1517 		ci.link_mode = get_link_mode(conn);
1518 	}
1519 	hci_dev_unlock(hdev);
1520 
1521 	if (!conn)
1522 		return -ENOENT;
1523 
1524 	return copy_to_user(ptr, &ci, sizeof(ci)) ? -EFAULT : 0;
1525 }
1526 
hci_get_auth_info(struct hci_dev * hdev,void __user * arg)1527 int hci_get_auth_info(struct hci_dev *hdev, void __user *arg)
1528 {
1529 	struct hci_auth_info_req req;
1530 	struct hci_conn *conn;
1531 
1532 	if (copy_from_user(&req, arg, sizeof(req)))
1533 		return -EFAULT;
1534 
1535 	hci_dev_lock(hdev);
1536 	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &req.bdaddr);
1537 	if (conn)
1538 		req.type = conn->auth_type;
1539 	hci_dev_unlock(hdev);
1540 
1541 	if (!conn)
1542 		return -ENOENT;
1543 
1544 	return copy_to_user(arg, &req, sizeof(req)) ? -EFAULT : 0;
1545 }
1546 
hci_chan_create(struct hci_conn * conn)1547 struct hci_chan *hci_chan_create(struct hci_conn *conn)
1548 {
1549 	struct hci_dev *hdev = conn->hdev;
1550 	struct hci_chan *chan;
1551 
1552 	BT_DBG("%s hcon %p", hdev->name, conn);
1553 
1554 	if (test_bit(HCI_CONN_DROP, &conn->flags)) {
1555 		BT_DBG("Refusing to create new hci_chan");
1556 		return NULL;
1557 	}
1558 
1559 	chan = kzalloc(sizeof(*chan), GFP_KERNEL);
1560 	if (!chan)
1561 		return NULL;
1562 
1563 	chan->conn = hci_conn_get(conn);
1564 	skb_queue_head_init(&chan->data_q);
1565 	chan->state = BT_CONNECTED;
1566 
1567 	list_add_rcu(&chan->list, &conn->chan_list);
1568 
1569 	return chan;
1570 }
1571 
hci_chan_del(struct hci_chan * chan)1572 void hci_chan_del(struct hci_chan *chan)
1573 {
1574 	struct hci_conn *conn = chan->conn;
1575 	struct hci_dev *hdev = conn->hdev;
1576 
1577 	BT_DBG("%s hcon %p chan %p", hdev->name, conn, chan);
1578 
1579 	list_del_rcu(&chan->list);
1580 
1581 	synchronize_rcu();
1582 
1583 	/* Prevent new hci_chan's to be created for this hci_conn */
1584 	set_bit(HCI_CONN_DROP, &conn->flags);
1585 
1586 	hci_conn_put(conn);
1587 
1588 	skb_queue_purge(&chan->data_q);
1589 	kfree(chan);
1590 }
1591 
hci_chan_list_flush(struct hci_conn * conn)1592 void hci_chan_list_flush(struct hci_conn *conn)
1593 {
1594 	struct hci_chan *chan, *n;
1595 
1596 	BT_DBG("hcon %p", conn);
1597 
1598 	list_for_each_entry_safe(chan, n, &conn->chan_list, list)
1599 		hci_chan_del(chan);
1600 }
1601 
__hci_chan_lookup_handle(struct hci_conn * hcon,__u16 handle)1602 static struct hci_chan *__hci_chan_lookup_handle(struct hci_conn *hcon,
1603 						 __u16 handle)
1604 {
1605 	struct hci_chan *hchan;
1606 
1607 	list_for_each_entry(hchan, &hcon->chan_list, list) {
1608 		if (hchan->handle == handle)
1609 			return hchan;
1610 	}
1611 
1612 	return NULL;
1613 }
1614 
hci_chan_lookup_handle(struct hci_dev * hdev,__u16 handle)1615 struct hci_chan *hci_chan_lookup_handle(struct hci_dev *hdev, __u16 handle)
1616 {
1617 	struct hci_conn_hash *h = &hdev->conn_hash;
1618 	struct hci_conn *hcon;
1619 	struct hci_chan *hchan = NULL;
1620 
1621 	rcu_read_lock();
1622 
1623 	list_for_each_entry_rcu(hcon, &h->list, list) {
1624 		hchan = __hci_chan_lookup_handle(hcon, handle);
1625 		if (hchan)
1626 			break;
1627 	}
1628 
1629 	rcu_read_unlock();
1630 
1631 	return hchan;
1632 }
1633