Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6] / net / bluetooth / hci_conn.c
1 /*
2    BlueZ - Bluetooth protocol stack for Linux
3    Copyright (C) 2000-2001 Qualcomm Incorporated
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/module.h>
28
29 #include <linux/types.h>
30 #include <linux/errno.h>
31 #include <linux/kernel.h>
32 #include <linux/slab.h>
33 #include <linux/poll.h>
34 #include <linux/fcntl.h>
35 #include <linux/init.h>
36 #include <linux/skbuff.h>
37 #include <linux/interrupt.h>
38 #include <linux/notifier.h>
39 #include <net/sock.h>
40
41 #include <asm/system.h>
42 #include <asm/uaccess.h>
43 #include <asm/unaligned.h>
44
45 #include <net/bluetooth/bluetooth.h>
46 #include <net/bluetooth/hci_core.h>
47
48 void hci_acl_connect(struct hci_conn *conn)
49 {
50         struct hci_dev *hdev = conn->hdev;
51         struct inquiry_entry *ie;
52         struct hci_cp_create_conn cp;
53
54         BT_DBG("%p", conn);
55
56         conn->state = BT_CONNECT;
57         conn->out = 1;
58
59         conn->link_mode = HCI_LM_MASTER;
60
61         conn->attempt++;
62
63         conn->link_policy = hdev->link_policy;
64
65         memset(&cp, 0, sizeof(cp));
66         bacpy(&cp.bdaddr, &conn->dst);
67         cp.pscan_rep_mode = 0x02;
68
69         if ((ie = hci_inquiry_cache_lookup(hdev, &conn->dst))) {
70                 if (inquiry_entry_age(ie) <= INQUIRY_ENTRY_AGE_MAX) {
71                         cp.pscan_rep_mode = ie->data.pscan_rep_mode;
72                         cp.pscan_mode     = ie->data.pscan_mode;
73                         cp.clock_offset   = ie->data.clock_offset |
74                                                         cpu_to_le16(0x8000);
75                 }
76
77                 memcpy(conn->dev_class, ie->data.dev_class, 3);
78                 conn->ssp_mode = ie->data.ssp_mode;
79         }
80
81         cp.pkt_type = cpu_to_le16(conn->pkt_type);
82         if (lmp_rswitch_capable(hdev) && !(hdev->link_mode & HCI_LM_MASTER))
83                 cp.role_switch = 0x01;
84         else
85                 cp.role_switch = 0x00;
86
87         hci_send_cmd(hdev, HCI_OP_CREATE_CONN, sizeof(cp), &cp);
88 }
89
90 static void hci_acl_connect_cancel(struct hci_conn *conn)
91 {
92         struct hci_cp_create_conn_cancel cp;
93
94         BT_DBG("%p", conn);
95
96         if (conn->hdev->hci_ver < 2)
97                 return;
98
99         bacpy(&cp.bdaddr, &conn->dst);
100         hci_send_cmd(conn->hdev, HCI_OP_CREATE_CONN_CANCEL, sizeof(cp), &cp);
101 }
102
103 void hci_acl_disconn(struct hci_conn *conn, __u8 reason)
104 {
105         struct hci_cp_disconnect cp;
106
107         BT_DBG("%p", conn);
108
109         conn->state = BT_DISCONN;
110
111         cp.handle = cpu_to_le16(conn->handle);
112         cp.reason = reason;
113         hci_send_cmd(conn->hdev, HCI_OP_DISCONNECT, sizeof(cp), &cp);
114 }
115
116 void hci_add_sco(struct hci_conn *conn, __u16 handle)
117 {
118         struct hci_dev *hdev = conn->hdev;
119         struct hci_cp_add_sco cp;
120
121         BT_DBG("%p", conn);
122
123         conn->state = BT_CONNECT;
124         conn->out = 1;
125
126         conn->attempt++;
127
128         cp.handle   = cpu_to_le16(handle);
129         cp.pkt_type = cpu_to_le16(conn->pkt_type);
130
131         hci_send_cmd(hdev, HCI_OP_ADD_SCO, sizeof(cp), &cp);
132 }
133
134 void hci_setup_sync(struct hci_conn *conn, __u16 handle)
135 {
136         struct hci_dev *hdev = conn->hdev;
137         struct hci_cp_setup_sync_conn cp;
138
139         BT_DBG("%p", conn);
140
141         conn->state = BT_CONNECT;
142         conn->out = 1;
143
144         conn->attempt++;
145
146         cp.handle   = cpu_to_le16(handle);
147         cp.pkt_type = cpu_to_le16(conn->pkt_type);
148
149         cp.tx_bandwidth   = cpu_to_le32(0x00001f40);
150         cp.rx_bandwidth   = cpu_to_le32(0x00001f40);
151         cp.max_latency    = cpu_to_le16(0xffff);
152         cp.voice_setting  = cpu_to_le16(hdev->voice_setting);
153         cp.retrans_effort = 0xff;
154
155         hci_send_cmd(hdev, HCI_OP_SETUP_SYNC_CONN, sizeof(cp), &cp);
156 }
157
158 static void hci_conn_timeout(unsigned long arg)
159 {
160         struct hci_conn *conn = (void *) arg;
161         struct hci_dev *hdev = conn->hdev;
162         __u8 reason;
163
164         BT_DBG("conn %p state %d", conn, conn->state);
165
166         if (atomic_read(&conn->refcnt))
167                 return;
168
169         hci_dev_lock(hdev);
170
171         switch (conn->state) {
172         case BT_CONNECT:
173         case BT_CONNECT2:
174                 if (conn->type == ACL_LINK && conn->out)
175                         hci_acl_connect_cancel(conn);
176                 break;
177         case BT_CONFIG:
178         case BT_CONNECTED:
179                 reason = hci_proto_disconn_ind(conn);
180                 hci_acl_disconn(conn, reason);
181                 break;
182         default:
183                 conn->state = BT_CLOSED;
184                 break;
185         }
186
187         hci_dev_unlock(hdev);
188 }
189
190 static void hci_conn_idle(unsigned long arg)
191 {
192         struct hci_conn *conn = (void *) arg;
193
194         BT_DBG("conn %p mode %d", conn, conn->mode);
195
196         hci_conn_enter_sniff_mode(conn);
197 }
198
199 struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst)
200 {
201         struct hci_conn *conn;
202
203         BT_DBG("%s dst %s", hdev->name, batostr(dst));
204
205         conn = kzalloc(sizeof(struct hci_conn), GFP_ATOMIC);
206         if (!conn)
207                 return NULL;
208
209         bacpy(&conn->dst, dst);
210         conn->hdev  = hdev;
211         conn->type  = type;
212         conn->mode  = HCI_CM_ACTIVE;
213         conn->state = BT_OPEN;
214
215         conn->power_save = 1;
216         conn->disc_timeout = HCI_DISCONN_TIMEOUT;
217
218         switch (type) {
219         case ACL_LINK:
220                 conn->pkt_type = hdev->pkt_type & ACL_PTYPE_MASK;
221                 break;
222         case SCO_LINK:
223                 if (lmp_esco_capable(hdev))
224                         conn->pkt_type = (hdev->esco_type & SCO_ESCO_MASK) |
225                                         (hdev->esco_type & EDR_ESCO_MASK);
226                 else
227                         conn->pkt_type = hdev->pkt_type & SCO_PTYPE_MASK;
228                 break;
229         case ESCO_LINK:
230                 conn->pkt_type = hdev->esco_type & ~EDR_ESCO_MASK;
231                 break;
232         }
233
234         skb_queue_head_init(&conn->data_q);
235
236         setup_timer(&conn->disc_timer, hci_conn_timeout, (unsigned long)conn);
237         setup_timer(&conn->idle_timer, hci_conn_idle, (unsigned long)conn);
238
239         atomic_set(&conn->refcnt, 0);
240
241         hci_dev_hold(hdev);
242
243         tasklet_disable(&hdev->tx_task);
244
245         hci_conn_hash_add(hdev, conn);
246         if (hdev->notify)
247                 hdev->notify(hdev, HCI_NOTIFY_CONN_ADD);
248
249         hci_conn_init_sysfs(conn);
250
251         tasklet_enable(&hdev->tx_task);
252
253         return conn;
254 }
255
256 int hci_conn_del(struct hci_conn *conn)
257 {
258         struct hci_dev *hdev = conn->hdev;
259
260         BT_DBG("%s conn %p handle %d", hdev->name, conn, conn->handle);
261
262         del_timer(&conn->idle_timer);
263
264         del_timer(&conn->disc_timer);
265
266         if (conn->type == ACL_LINK) {
267                 struct hci_conn *sco = conn->link;
268                 if (sco)
269                         sco->link = NULL;
270
271                 /* Unacked frames */
272                 hdev->acl_cnt += conn->sent;
273         } else {
274                 struct hci_conn *acl = conn->link;
275                 if (acl) {
276                         acl->link = NULL;
277                         hci_conn_put(acl);
278                 }
279         }
280
281         tasklet_disable(&hdev->tx_task);
282
283         hci_conn_hash_del(hdev, conn);
284         if (hdev->notify)
285                 hdev->notify(hdev, HCI_NOTIFY_CONN_DEL);
286
287         tasklet_enable(&hdev->tx_task);
288
289         skb_queue_purge(&conn->data_q);
290
291         hci_conn_del_sysfs(conn);
292
293         hci_dev_put(hdev);
294
295         return 0;
296 }
297
298 struct hci_dev *hci_get_route(bdaddr_t *dst, bdaddr_t *src)
299 {
300         int use_src = bacmp(src, BDADDR_ANY);
301         struct hci_dev *hdev = NULL;
302         struct list_head *p;
303
304         BT_DBG("%s -> %s", batostr(src), batostr(dst));
305
306         read_lock_bh(&hci_dev_list_lock);
307
308         list_for_each(p, &hci_dev_list) {
309                 struct hci_dev *d = list_entry(p, struct hci_dev, list);
310
311                 if (!test_bit(HCI_UP, &d->flags) || test_bit(HCI_RAW, &d->flags))
312                         continue;
313
314                 /* Simple routing:
315                  *   No source address - find interface with bdaddr != dst
316                  *   Source address    - find interface with bdaddr == src
317                  */
318
319                 if (use_src) {
320                         if (!bacmp(&d->bdaddr, src)) {
321                                 hdev = d; break;
322                         }
323                 } else {
324                         if (bacmp(&d->bdaddr, dst)) {
325                                 hdev = d; break;
326                         }
327                 }
328         }
329
330         if (hdev)
331                 hdev = hci_dev_hold(hdev);
332
333         read_unlock_bh(&hci_dev_list_lock);
334         return hdev;
335 }
336 EXPORT_SYMBOL(hci_get_route);
337
338 /* Create SCO or ACL connection.
339  * Device _must_ be locked */
340 struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8 sec_level, __u8 auth_type)
341 {
342         struct hci_conn *acl;
343         struct hci_conn *sco;
344
345         BT_DBG("%s dst %s", hdev->name, batostr(dst));
346
347         if (!(acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst))) {
348                 if (!(acl = hci_conn_add(hdev, ACL_LINK, dst)))
349                         return NULL;
350         }
351
352         hci_conn_hold(acl);
353
354         if (acl->state == BT_OPEN || acl->state == BT_CLOSED) {
355                 acl->sec_level = sec_level;
356                 acl->auth_type = auth_type;
357                 hci_acl_connect(acl);
358         }
359
360         if (type == ACL_LINK)
361                 return acl;
362
363         if (!(sco = hci_conn_hash_lookup_ba(hdev, type, dst))) {
364                 if (!(sco = hci_conn_add(hdev, type, dst))) {
365                         hci_conn_put(acl);
366                         return NULL;
367                 }
368         }
369
370         acl->link = sco;
371         sco->link = acl;
372
373         hci_conn_hold(sco);
374
375         if (acl->state == BT_CONNECTED &&
376                         (sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
377                 if (lmp_esco_capable(hdev))
378                         hci_setup_sync(sco, acl->handle);
379                 else
380                         hci_add_sco(sco, acl->handle);
381         }
382
383         return sco;
384 }
385 EXPORT_SYMBOL(hci_connect);
386
387 /* Check link security requirement */
388 int hci_conn_check_link_mode(struct hci_conn *conn)
389 {
390         BT_DBG("conn %p", conn);
391
392         if (conn->ssp_mode > 0 && conn->hdev->ssp_mode > 0 &&
393                                         !(conn->link_mode & HCI_LM_ENCRYPT))
394                 return 0;
395
396         return 1;
397 }
398 EXPORT_SYMBOL(hci_conn_check_link_mode);
399
400 /* Authenticate remote device */
401 static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
402 {
403         BT_DBG("conn %p", conn);
404
405         if (sec_level > conn->sec_level)
406                 conn->sec_level = sec_level;
407         else if (conn->link_mode & HCI_LM_AUTH)
408                 return 1;
409
410         conn->auth_type = auth_type;
411
412         if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->pend)) {
413                 struct hci_cp_auth_requested cp;
414                 cp.handle = cpu_to_le16(conn->handle);
415                 hci_send_cmd(conn->hdev, HCI_OP_AUTH_REQUESTED,
416                                                         sizeof(cp), &cp);
417         }
418
419         return 0;
420 }
421
422 /* Enable security */
423 int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
424 {
425         BT_DBG("conn %p", conn);
426
427         if (sec_level == BT_SECURITY_SDP)
428                 return 1;
429
430         if (sec_level == BT_SECURITY_LOW &&
431                                 (!conn->ssp_mode || !conn->hdev->ssp_mode))
432                 return 1;
433
434         if (conn->link_mode & HCI_LM_ENCRYPT)
435                 return hci_conn_auth(conn, sec_level, auth_type);
436
437         if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &conn->pend))
438                 return 0;
439
440         if (hci_conn_auth(conn, sec_level, auth_type)) {
441                 struct hci_cp_set_conn_encrypt cp;
442                 cp.handle  = cpu_to_le16(conn->handle);
443                 cp.encrypt = 1;
444                 hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT,
445                                                         sizeof(cp), &cp);
446         }
447
448         return 0;
449 }
450 EXPORT_SYMBOL(hci_conn_security);
451
452 /* Change link key */
453 int hci_conn_change_link_key(struct hci_conn *conn)
454 {
455         BT_DBG("conn %p", conn);
456
457         if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->pend)) {
458                 struct hci_cp_change_conn_link_key cp;
459                 cp.handle = cpu_to_le16(conn->handle);
460                 hci_send_cmd(conn->hdev, HCI_OP_CHANGE_CONN_LINK_KEY,
461                                                         sizeof(cp), &cp);
462         }
463
464         return 0;
465 }
466 EXPORT_SYMBOL(hci_conn_change_link_key);
467
468 /* Switch role */
469 int hci_conn_switch_role(struct hci_conn *conn, __u8 role)
470 {
471         BT_DBG("conn %p", conn);
472
473         if (!role && conn->link_mode & HCI_LM_MASTER)
474                 return 1;
475
476         if (!test_and_set_bit(HCI_CONN_RSWITCH_PEND, &conn->pend)) {
477                 struct hci_cp_switch_role cp;
478                 bacpy(&cp.bdaddr, &conn->dst);
479                 cp.role = role;
480                 hci_send_cmd(conn->hdev, HCI_OP_SWITCH_ROLE, sizeof(cp), &cp);
481         }
482
483         return 0;
484 }
485 EXPORT_SYMBOL(hci_conn_switch_role);
486
487 /* Enter active mode */
488 void hci_conn_enter_active_mode(struct hci_conn *conn)
489 {
490         struct hci_dev *hdev = conn->hdev;
491
492         BT_DBG("conn %p mode %d", conn, conn->mode);
493
494         if (test_bit(HCI_RAW, &hdev->flags))
495                 return;
496
497         if (conn->mode != HCI_CM_SNIFF || !conn->power_save)
498                 goto timer;
499
500         if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->pend)) {
501                 struct hci_cp_exit_sniff_mode cp;
502                 cp.handle = cpu_to_le16(conn->handle);
503                 hci_send_cmd(hdev, HCI_OP_EXIT_SNIFF_MODE, sizeof(cp), &cp);
504         }
505
506 timer:
507         if (hdev->idle_timeout > 0)
508                 mod_timer(&conn->idle_timer,
509                         jiffies + msecs_to_jiffies(hdev->idle_timeout));
510 }
511
512 /* Enter sniff mode */
513 void hci_conn_enter_sniff_mode(struct hci_conn *conn)
514 {
515         struct hci_dev *hdev = conn->hdev;
516
517         BT_DBG("conn %p mode %d", conn, conn->mode);
518
519         if (test_bit(HCI_RAW, &hdev->flags))
520                 return;
521
522         if (!lmp_sniff_capable(hdev) || !lmp_sniff_capable(conn))
523                 return;
524
525         if (conn->mode != HCI_CM_ACTIVE || !(conn->link_policy & HCI_LP_SNIFF))
526                 return;
527
528         if (lmp_sniffsubr_capable(hdev) && lmp_sniffsubr_capable(conn)) {
529                 struct hci_cp_sniff_subrate cp;
530                 cp.handle             = cpu_to_le16(conn->handle);
531                 cp.max_latency        = cpu_to_le16(0);
532                 cp.min_remote_timeout = cpu_to_le16(0);
533                 cp.min_local_timeout  = cpu_to_le16(0);
534                 hci_send_cmd(hdev, HCI_OP_SNIFF_SUBRATE, sizeof(cp), &cp);
535         }
536
537         if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->pend)) {
538                 struct hci_cp_sniff_mode cp;
539                 cp.handle       = cpu_to_le16(conn->handle);
540                 cp.max_interval = cpu_to_le16(hdev->sniff_max_interval);
541                 cp.min_interval = cpu_to_le16(hdev->sniff_min_interval);
542                 cp.attempt      = cpu_to_le16(4);
543                 cp.timeout      = cpu_to_le16(1);
544                 hci_send_cmd(hdev, HCI_OP_SNIFF_MODE, sizeof(cp), &cp);
545         }
546 }
547
548 /* Drop all connection on the device */
549 void hci_conn_hash_flush(struct hci_dev *hdev)
550 {
551         struct hci_conn_hash *h = &hdev->conn_hash;
552         struct list_head *p;
553
554         BT_DBG("hdev %s", hdev->name);
555
556         p = h->list.next;
557         while (p != &h->list) {
558                 struct hci_conn *c;
559
560                 c = list_entry(p, struct hci_conn, list);
561                 p = p->next;
562
563                 c->state = BT_CLOSED;
564
565                 hci_proto_disconn_cfm(c, 0x16);
566                 hci_conn_del(c);
567         }
568 }
569
570 /* Check pending connect attempts */
571 void hci_conn_check_pending(struct hci_dev *hdev)
572 {
573         struct hci_conn *conn;
574
575         BT_DBG("hdev %s", hdev->name);
576
577         hci_dev_lock(hdev);
578
579         conn = hci_conn_hash_lookup_state(hdev, ACL_LINK, BT_CONNECT2);
580         if (conn)
581                 hci_acl_connect(conn);
582
583         hci_dev_unlock(hdev);
584 }
585
586 int hci_get_conn_list(void __user *arg)
587 {
588         struct hci_conn_list_req req, *cl;
589         struct hci_conn_info *ci;
590         struct hci_dev *hdev;
591         struct list_head *p;
592         int n = 0, size, err;
593
594         if (copy_from_user(&req, arg, sizeof(req)))
595                 return -EFAULT;
596
597         if (!req.conn_num || req.conn_num > (PAGE_SIZE * 2) / sizeof(*ci))
598                 return -EINVAL;
599
600         size = sizeof(req) + req.conn_num * sizeof(*ci);
601
602         if (!(cl = kmalloc(size, GFP_KERNEL)))
603                 return -ENOMEM;
604
605         if (!(hdev = hci_dev_get(req.dev_id))) {
606                 kfree(cl);
607                 return -ENODEV;
608         }
609
610         ci = cl->conn_info;
611
612         hci_dev_lock_bh(hdev);
613         list_for_each(p, &hdev->conn_hash.list) {
614                 register struct hci_conn *c;
615                 c = list_entry(p, struct hci_conn, list);
616
617                 bacpy(&(ci + n)->bdaddr, &c->dst);
618                 (ci + n)->handle = c->handle;
619                 (ci + n)->type  = c->type;
620                 (ci + n)->out   = c->out;
621                 (ci + n)->state = c->state;
622                 (ci + n)->link_mode = c->link_mode;
623                 if (++n >= req.conn_num)
624                         break;
625         }
626         hci_dev_unlock_bh(hdev);
627
628         cl->dev_id = hdev->id;
629         cl->conn_num = n;
630         size = sizeof(req) + n * sizeof(*ci);
631
632         hci_dev_put(hdev);
633
634         err = copy_to_user(arg, cl, size);
635         kfree(cl);
636
637         return err ? -EFAULT : 0;
638 }
639
640 int hci_get_conn_info(struct hci_dev *hdev, void __user *arg)
641 {
642         struct hci_conn_info_req req;
643         struct hci_conn_info ci;
644         struct hci_conn *conn;
645         char __user *ptr = arg + sizeof(req);
646
647         if (copy_from_user(&req, arg, sizeof(req)))
648                 return -EFAULT;
649
650         hci_dev_lock_bh(hdev);
651         conn = hci_conn_hash_lookup_ba(hdev, req.type, &req.bdaddr);
652         if (conn) {
653                 bacpy(&ci.bdaddr, &conn->dst);
654                 ci.handle = conn->handle;
655                 ci.type  = conn->type;
656                 ci.out   = conn->out;
657                 ci.state = conn->state;
658                 ci.link_mode = conn->link_mode;
659         }
660         hci_dev_unlock_bh(hdev);
661
662         if (!conn)
663                 return -ENOENT;
664
665         return copy_to_user(ptr, &ci, sizeof(ci)) ? -EFAULT : 0;
666 }
667
668 int hci_get_auth_info(struct hci_dev *hdev, void __user *arg)
669 {
670         struct hci_auth_info_req req;
671         struct hci_conn *conn;
672
673         if (copy_from_user(&req, arg, sizeof(req)))
674                 return -EFAULT;
675
676         hci_dev_lock_bh(hdev);
677         conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &req.bdaddr);
678         if (conn)
679                 req.type = conn->auth_type;
680         hci_dev_unlock_bh(hdev);
681
682         if (!conn)
683                 return -ENOENT;
684
685         return copy_to_user(arg, &req, sizeof(req)) ? -EFAULT : 0;
686 }