xref: /linux/net/bluetooth/hidp/core.c (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
1 /*
2    HIDP implementation for Linux Bluetooth stack (BlueZ).
3    Copyright (C) 2003-2004 Marcel Holtmann <marcel@holtmann.org>
4    Copyright (C) 2013 David Herrmann <dh.herrmann@gmail.com>
5 
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License version 2 as
8    published by the Free Software Foundation;
9 
10    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
11    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
12    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
13    IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
14    CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
15    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 
19    ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
20    COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
21    SOFTWARE IS DISCLAIMED.
22 */
23 
24 #include <linux/kref.h>
25 #include <linux/module.h>
26 #include <linux/file.h>
27 #include <linux/kthread.h>
28 #include <linux/hidraw.h>
29 
30 #include <net/bluetooth/bluetooth.h>
31 #include <net/bluetooth/hci_core.h>
32 #include <net/bluetooth/l2cap.h>
33 
34 #include "hidp.h"
35 
36 #define VERSION "1.2"
37 
38 static DECLARE_RWSEM(hidp_session_sem);
39 static DECLARE_WAIT_QUEUE_HEAD(hidp_session_wq);
40 static LIST_HEAD(hidp_session_list);
41 
42 static unsigned char hidp_keycode[256] = {
43 	  0,   0,   0,   0,  30,  48,  46,  32,  18,  33,  34,  35,  23,  36,
44 	 37,  38,  50,  49,  24,  25,  16,  19,  31,  20,  22,  47,  17,  45,
45 	 21,  44,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11,  28,   1,
46 	 14,  15,  57,  12,  13,  26,  27,  43,  43,  39,  40,  41,  51,  52,
47 	 53,  58,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  87,  88,
48 	 99,  70, 119, 110, 102, 104, 111, 107, 109, 106, 105, 108, 103,  69,
49 	 98,  55,  74,  78,  96,  79,  80,  81,  75,  76,  77,  71,  72,  73,
50 	 82,  83,  86, 127, 116, 117, 183, 184, 185, 186, 187, 188, 189, 190,
51 	191, 192, 193, 194, 134, 138, 130, 132, 128, 129, 131, 137, 133, 135,
52 	136, 113, 115, 114,   0,   0,   0, 121,   0,  89,  93, 124,  92,  94,
53 	 95,   0,   0,   0, 122, 123,  90,  91,  85,   0,   0,   0,   0,   0,
54 	  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
55 	  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
56 	  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
57 	  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
58 	  0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,
59 	 29,  42,  56, 125,  97,  54, 100, 126, 164, 166, 165, 163, 161, 115,
60 	114, 113, 150, 158, 159, 128, 136, 177, 178, 176, 142, 152, 173, 140
61 };
62 
63 static unsigned char hidp_mkeyspat[] = { 0x01, 0x01, 0x01, 0x01, 0x01, 0x01 };
64 
65 static int hidp_session_probe(struct l2cap_conn *conn,
66 			      struct l2cap_user *user);
67 static void hidp_session_remove(struct l2cap_conn *conn,
68 				struct l2cap_user *user);
69 static int hidp_session_thread(void *arg);
70 static void hidp_session_terminate(struct hidp_session *s);
71 
72 static void hidp_copy_session(struct hidp_session *session, struct hidp_conninfo *ci)
73 {
74 	u32 valid_flags = 0;
75 	memset(ci, 0, sizeof(*ci));
76 	bacpy(&ci->bdaddr, &session->bdaddr);
77 
78 	ci->flags = session->flags & valid_flags;
79 	ci->state = BT_CONNECTED;
80 
81 	if (session->input) {
82 		ci->vendor  = session->input->id.vendor;
83 		ci->product = session->input->id.product;
84 		ci->version = session->input->id.version;
85 		if (session->input->name)
86 			strscpy(ci->name, session->input->name, 128);
87 		else
88 			strscpy(ci->name, "HID Boot Device", 128);
89 	} else if (session->hid) {
90 		ci->vendor  = session->hid->vendor;
91 		ci->product = session->hid->product;
92 		ci->version = session->hid->version;
93 		strscpy(ci->name, session->hid->name, 128);
94 	}
95 }
96 
97 /* assemble skb, queue message on @transmit and wake up the session thread */
98 static int hidp_send_message(struct hidp_session *session, struct socket *sock,
99 			     struct sk_buff_head *transmit, unsigned char hdr,
100 			     const unsigned char *data, int size)
101 {
102 	struct sk_buff *skb;
103 	struct sock *sk = sock->sk;
104 	int ret;
105 
106 	BT_DBG("session %p data %p size %d", session, data, size);
107 
108 	if (atomic_read(&session->terminate))
109 		return -EIO;
110 
111 	skb = alloc_skb(size + 1, GFP_ATOMIC);
112 	if (!skb) {
113 		BT_ERR("Can't allocate memory for new frame");
114 		return -ENOMEM;
115 	}
116 
117 	skb_put_u8(skb, hdr);
118 	if (data && size > 0) {
119 		skb_put_data(skb, data, size);
120 		ret = size;
121 	} else {
122 		ret = 0;
123 	}
124 
125 	skb_queue_tail(transmit, skb);
126 	wake_up_interruptible(sk_sleep(sk));
127 
128 	return ret;
129 }
130 
131 static int hidp_send_ctrl_message(struct hidp_session *session,
132 				  unsigned char hdr, const unsigned char *data,
133 				  int size)
134 {
135 	return hidp_send_message(session, session->ctrl_sock,
136 				 &session->ctrl_transmit, hdr, data, size);
137 }
138 
139 static int hidp_send_intr_message(struct hidp_session *session,
140 				  unsigned char hdr, const unsigned char *data,
141 				  int size)
142 {
143 	return hidp_send_message(session, session->intr_sock,
144 				 &session->intr_transmit, hdr, data, size);
145 }
146 
147 static int hidp_input_event(struct input_dev *dev, unsigned int type,
148 			    unsigned int code, int value)
149 {
150 	struct hidp_session *session = input_get_drvdata(dev);
151 	unsigned char newleds;
152 	unsigned char hdr, data[2];
153 
154 	BT_DBG("session %p type %d code %d value %d",
155 	       session, type, code, value);
156 
157 	if (type != EV_LED)
158 		return -1;
159 
160 	newleds = (!!test_bit(LED_KANA,    dev->led) << 3) |
161 		  (!!test_bit(LED_COMPOSE, dev->led) << 3) |
162 		  (!!test_bit(LED_SCROLLL, dev->led) << 2) |
163 		  (!!test_bit(LED_CAPSL,   dev->led) << 1) |
164 		  (!!test_bit(LED_NUML,    dev->led) << 0);
165 
166 	if (session->leds == newleds)
167 		return 0;
168 
169 	session->leds = newleds;
170 
171 	hdr = HIDP_TRANS_DATA | HIDP_DATA_RTYPE_OUPUT;
172 	data[0] = 0x01;
173 	data[1] = newleds;
174 
175 	return hidp_send_intr_message(session, hdr, data, 2);
176 }
177 
178 static void hidp_input_report(struct hidp_session *session, struct sk_buff *skb)
179 {
180 	struct input_dev *dev = session->input;
181 	unsigned char *keys = session->keys;
182 	unsigned char *udata = skb->data + 1;
183 	signed char *sdata = skb->data + 1;
184 	int i, size = skb->len - 1;
185 
186 	switch (skb->data[0]) {
187 	case 0x01:	/* Keyboard report */
188 		for (i = 0; i < 8; i++)
189 			input_report_key(dev, hidp_keycode[i + 224], (udata[0] >> i) & 1);
190 
191 		/* If all the key codes have been set to 0x01, it means
192 		 * too many keys were pressed at the same time. */
193 		if (!memcmp(udata + 2, hidp_mkeyspat, 6))
194 			break;
195 
196 		for (i = 2; i < 8; i++) {
197 			if (keys[i] > 3 && memscan(udata + 2, keys[i], 6) == udata + 8) {
198 				if (hidp_keycode[keys[i]])
199 					input_report_key(dev, hidp_keycode[keys[i]], 0);
200 				else
201 					BT_ERR("Unknown key (scancode %#x) released.", keys[i]);
202 			}
203 
204 			if (udata[i] > 3 && memscan(keys + 2, udata[i], 6) == keys + 8) {
205 				if (hidp_keycode[udata[i]])
206 					input_report_key(dev, hidp_keycode[udata[i]], 1);
207 				else
208 					BT_ERR("Unknown key (scancode %#x) pressed.", udata[i]);
209 			}
210 		}
211 
212 		memcpy(keys, udata, 8);
213 		break;
214 
215 	case 0x02:	/* Mouse report */
216 		input_report_key(dev, BTN_LEFT,   sdata[0] & 0x01);
217 		input_report_key(dev, BTN_RIGHT,  sdata[0] & 0x02);
218 		input_report_key(dev, BTN_MIDDLE, sdata[0] & 0x04);
219 		input_report_key(dev, BTN_SIDE,   sdata[0] & 0x08);
220 		input_report_key(dev, BTN_EXTRA,  sdata[0] & 0x10);
221 
222 		input_report_rel(dev, REL_X, sdata[1]);
223 		input_report_rel(dev, REL_Y, sdata[2]);
224 
225 		if (size > 3)
226 			input_report_rel(dev, REL_WHEEL, sdata[3]);
227 		break;
228 	}
229 
230 	input_sync(dev);
231 }
232 
233 static int hidp_get_raw_report(struct hid_device *hid,
234 		unsigned char report_number,
235 		unsigned char *data, size_t count,
236 		unsigned char report_type)
237 {
238 	struct hidp_session *session = hid->driver_data;
239 	struct sk_buff *skb;
240 	size_t len;
241 	int numbered_reports = hid->report_enum[report_type].numbered;
242 	int ret;
243 
244 	if (atomic_read(&session->terminate))
245 		return -EIO;
246 
247 	switch (report_type) {
248 	case HID_FEATURE_REPORT:
249 		report_type = HIDP_TRANS_GET_REPORT | HIDP_DATA_RTYPE_FEATURE;
250 		break;
251 	case HID_INPUT_REPORT:
252 		report_type = HIDP_TRANS_GET_REPORT | HIDP_DATA_RTYPE_INPUT;
253 		break;
254 	case HID_OUTPUT_REPORT:
255 		report_type = HIDP_TRANS_GET_REPORT | HIDP_DATA_RTYPE_OUPUT;
256 		break;
257 	default:
258 		return -EINVAL;
259 	}
260 
261 	if (mutex_lock_interruptible(&session->report_mutex))
262 		return -ERESTARTSYS;
263 
264 	/* Set up our wait, and send the report request to the device. */
265 	session->waiting_report_type = report_type & HIDP_DATA_RTYPE_MASK;
266 	session->waiting_report_number = numbered_reports ? report_number : -1;
267 	set_bit(HIDP_WAITING_FOR_RETURN, &session->flags);
268 	data[0] = report_number;
269 	ret = hidp_send_ctrl_message(session, report_type, data, 1);
270 	if (ret < 0)
271 		goto err;
272 
273 	/* Wait for the return of the report. The returned report
274 	   gets put in session->report_return.  */
275 	while (test_bit(HIDP_WAITING_FOR_RETURN, &session->flags) &&
276 	       !atomic_read(&session->terminate)) {
277 		int res;
278 
279 		res = wait_event_interruptible_timeout(session->report_queue,
280 			!test_bit(HIDP_WAITING_FOR_RETURN, &session->flags)
281 				|| atomic_read(&session->terminate),
282 			5*HZ);
283 		if (res == 0) {
284 			/* timeout */
285 			ret = -EIO;
286 			goto err;
287 		}
288 		if (res < 0) {
289 			/* signal */
290 			ret = -ERESTARTSYS;
291 			goto err;
292 		}
293 	}
294 
295 	skb = session->report_return;
296 	if (skb) {
297 		len = skb->len < count ? skb->len : count;
298 		memcpy(data, skb->data, len);
299 
300 		kfree_skb(skb);
301 		session->report_return = NULL;
302 	} else {
303 		/* Device returned a HANDSHAKE, indicating  protocol error. */
304 		len = -EIO;
305 	}
306 
307 	clear_bit(HIDP_WAITING_FOR_RETURN, &session->flags);
308 	mutex_unlock(&session->report_mutex);
309 
310 	return len;
311 
312 err:
313 	clear_bit(HIDP_WAITING_FOR_RETURN, &session->flags);
314 	mutex_unlock(&session->report_mutex);
315 	return ret;
316 }
317 
318 static int hidp_set_raw_report(struct hid_device *hid, unsigned char reportnum,
319 			       unsigned char *data, size_t count,
320 			       unsigned char report_type)
321 {
322 	struct hidp_session *session = hid->driver_data;
323 	int ret;
324 
325 	switch (report_type) {
326 	case HID_FEATURE_REPORT:
327 		report_type = HIDP_TRANS_SET_REPORT | HIDP_DATA_RTYPE_FEATURE;
328 		break;
329 	case HID_INPUT_REPORT:
330 		report_type = HIDP_TRANS_SET_REPORT | HIDP_DATA_RTYPE_INPUT;
331 		break;
332 	case HID_OUTPUT_REPORT:
333 		report_type = HIDP_TRANS_SET_REPORT | HIDP_DATA_RTYPE_OUPUT;
334 		break;
335 	default:
336 		return -EINVAL;
337 	}
338 
339 	if (mutex_lock_interruptible(&session->report_mutex))
340 		return -ERESTARTSYS;
341 
342 	/* Set up our wait, and send the report request to the device. */
343 	data[0] = reportnum;
344 	set_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags);
345 	ret = hidp_send_ctrl_message(session, report_type, data, count);
346 	if (ret < 0)
347 		goto err;
348 
349 	/* Wait for the ACK from the device. */
350 	while (test_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags) &&
351 	       !atomic_read(&session->terminate)) {
352 		int res;
353 
354 		res = wait_event_interruptible_timeout(session->report_queue,
355 			!test_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags)
356 				|| atomic_read(&session->terminate),
357 			10*HZ);
358 		if (res == 0) {
359 			/* timeout */
360 			ret = -EIO;
361 			goto err;
362 		}
363 		if (res < 0) {
364 			/* signal */
365 			ret = -ERESTARTSYS;
366 			goto err;
367 		}
368 	}
369 
370 	if (!session->output_report_success) {
371 		ret = -EIO;
372 		goto err;
373 	}
374 
375 	ret = count;
376 
377 err:
378 	clear_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags);
379 	mutex_unlock(&session->report_mutex);
380 	return ret;
381 }
382 
383 static int hidp_output_report(struct hid_device *hid, __u8 *data, size_t count)
384 {
385 	struct hidp_session *session = hid->driver_data;
386 
387 	return hidp_send_intr_message(session,
388 				      HIDP_TRANS_DATA | HIDP_DATA_RTYPE_OUPUT,
389 				      data, count);
390 }
391 
392 static int hidp_raw_request(struct hid_device *hid, unsigned char reportnum,
393 			    __u8 *buf, size_t len, unsigned char rtype,
394 			    int reqtype)
395 {
396 	switch (reqtype) {
397 	case HID_REQ_GET_REPORT:
398 		return hidp_get_raw_report(hid, reportnum, buf, len, rtype);
399 	case HID_REQ_SET_REPORT:
400 		return hidp_set_raw_report(hid, reportnum, buf, len, rtype);
401 	default:
402 		return -EIO;
403 	}
404 }
405 
406 static void hidp_idle_timeout(struct timer_list *t)
407 {
408 	struct hidp_session *session = from_timer(session, t, timer);
409 
410 	/* The HIDP user-space API only contains calls to add and remove
411 	 * devices. There is no way to forward events of any kind. Therefore,
412 	 * we have to forcefully disconnect a device on idle-timeouts. This is
413 	 * unfortunate and weird API design, but it is spec-compliant and
414 	 * required for backwards-compatibility. Hence, on idle-timeout, we
415 	 * signal driver-detach events, so poll() will be woken up with an
416 	 * error-condition on both sockets.
417 	 */
418 
419 	session->intr_sock->sk->sk_err = EUNATCH;
420 	session->ctrl_sock->sk->sk_err = EUNATCH;
421 	wake_up_interruptible(sk_sleep(session->intr_sock->sk));
422 	wake_up_interruptible(sk_sleep(session->ctrl_sock->sk));
423 
424 	hidp_session_terminate(session);
425 }
426 
427 static void hidp_set_timer(struct hidp_session *session)
428 {
429 	if (session->idle_to > 0)
430 		mod_timer(&session->timer, jiffies + HZ * session->idle_to);
431 }
432 
433 static void hidp_del_timer(struct hidp_session *session)
434 {
435 	if (session->idle_to > 0)
436 		del_timer_sync(&session->timer);
437 }
438 
439 static void hidp_process_report(struct hidp_session *session, int type,
440 				const u8 *data, unsigned int len, int intr)
441 {
442 	if (len > HID_MAX_BUFFER_SIZE)
443 		len = HID_MAX_BUFFER_SIZE;
444 
445 	memcpy(session->input_buf, data, len);
446 	hid_input_report(session->hid, type, session->input_buf, len, intr);
447 }
448 
449 static void hidp_process_handshake(struct hidp_session *session,
450 					unsigned char param)
451 {
452 	BT_DBG("session %p param 0x%02x", session, param);
453 	session->output_report_success = 0; /* default condition */
454 
455 	switch (param) {
456 	case HIDP_HSHK_SUCCESSFUL:
457 		/* FIXME: Call into SET_ GET_ handlers here */
458 		session->output_report_success = 1;
459 		break;
460 
461 	case HIDP_HSHK_NOT_READY:
462 	case HIDP_HSHK_ERR_INVALID_REPORT_ID:
463 	case HIDP_HSHK_ERR_UNSUPPORTED_REQUEST:
464 	case HIDP_HSHK_ERR_INVALID_PARAMETER:
465 		if (test_and_clear_bit(HIDP_WAITING_FOR_RETURN, &session->flags))
466 			wake_up_interruptible(&session->report_queue);
467 
468 		/* FIXME: Call into SET_ GET_ handlers here */
469 		break;
470 
471 	case HIDP_HSHK_ERR_UNKNOWN:
472 		break;
473 
474 	case HIDP_HSHK_ERR_FATAL:
475 		/* Device requests a reboot, as this is the only way this error
476 		 * can be recovered. */
477 		hidp_send_ctrl_message(session,
478 			HIDP_TRANS_HID_CONTROL | HIDP_CTRL_SOFT_RESET, NULL, 0);
479 		break;
480 
481 	default:
482 		hidp_send_ctrl_message(session,
483 			HIDP_TRANS_HANDSHAKE | HIDP_HSHK_ERR_INVALID_PARAMETER, NULL, 0);
484 		break;
485 	}
486 
487 	/* Wake up the waiting thread. */
488 	if (test_and_clear_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags))
489 		wake_up_interruptible(&session->report_queue);
490 }
491 
492 static void hidp_process_hid_control(struct hidp_session *session,
493 					unsigned char param)
494 {
495 	BT_DBG("session %p param 0x%02x", session, param);
496 
497 	if (param == HIDP_CTRL_VIRTUAL_CABLE_UNPLUG) {
498 		/* Flush the transmit queues */
499 		skb_queue_purge(&session->ctrl_transmit);
500 		skb_queue_purge(&session->intr_transmit);
501 
502 		hidp_session_terminate(session);
503 	}
504 }
505 
506 /* Returns true if the passed-in skb should be freed by the caller. */
507 static int hidp_process_data(struct hidp_session *session, struct sk_buff *skb,
508 				unsigned char param)
509 {
510 	int done_with_skb = 1;
511 	BT_DBG("session %p skb %p len %u param 0x%02x", session, skb, skb->len, param);
512 
513 	switch (param) {
514 	case HIDP_DATA_RTYPE_INPUT:
515 		hidp_set_timer(session);
516 
517 		if (session->input)
518 			hidp_input_report(session, skb);
519 
520 		if (session->hid)
521 			hidp_process_report(session, HID_INPUT_REPORT,
522 					    skb->data, skb->len, 0);
523 		break;
524 
525 	case HIDP_DATA_RTYPE_OTHER:
526 	case HIDP_DATA_RTYPE_OUPUT:
527 	case HIDP_DATA_RTYPE_FEATURE:
528 		break;
529 
530 	default:
531 		hidp_send_ctrl_message(session,
532 			HIDP_TRANS_HANDSHAKE | HIDP_HSHK_ERR_INVALID_PARAMETER, NULL, 0);
533 	}
534 
535 	if (test_bit(HIDP_WAITING_FOR_RETURN, &session->flags) &&
536 				param == session->waiting_report_type) {
537 		if (session->waiting_report_number < 0 ||
538 		    session->waiting_report_number == skb->data[0]) {
539 			/* hidp_get_raw_report() is waiting on this report. */
540 			session->report_return = skb;
541 			done_with_skb = 0;
542 			clear_bit(HIDP_WAITING_FOR_RETURN, &session->flags);
543 			wake_up_interruptible(&session->report_queue);
544 		}
545 	}
546 
547 	return done_with_skb;
548 }
549 
550 static void hidp_recv_ctrl_frame(struct hidp_session *session,
551 					struct sk_buff *skb)
552 {
553 	unsigned char hdr, type, param;
554 	int free_skb = 1;
555 
556 	BT_DBG("session %p skb %p len %u", session, skb, skb->len);
557 
558 	hdr = skb->data[0];
559 	skb_pull(skb, 1);
560 
561 	type = hdr & HIDP_HEADER_TRANS_MASK;
562 	param = hdr & HIDP_HEADER_PARAM_MASK;
563 
564 	switch (type) {
565 	case HIDP_TRANS_HANDSHAKE:
566 		hidp_process_handshake(session, param);
567 		break;
568 
569 	case HIDP_TRANS_HID_CONTROL:
570 		hidp_process_hid_control(session, param);
571 		break;
572 
573 	case HIDP_TRANS_DATA:
574 		free_skb = hidp_process_data(session, skb, param);
575 		break;
576 
577 	default:
578 		hidp_send_ctrl_message(session,
579 			HIDP_TRANS_HANDSHAKE | HIDP_HSHK_ERR_UNSUPPORTED_REQUEST, NULL, 0);
580 		break;
581 	}
582 
583 	if (free_skb)
584 		kfree_skb(skb);
585 }
586 
587 static void hidp_recv_intr_frame(struct hidp_session *session,
588 				struct sk_buff *skb)
589 {
590 	unsigned char hdr;
591 
592 	BT_DBG("session %p skb %p len %u", session, skb, skb->len);
593 
594 	hdr = skb->data[0];
595 	skb_pull(skb, 1);
596 
597 	if (hdr == (HIDP_TRANS_DATA | HIDP_DATA_RTYPE_INPUT)) {
598 		hidp_set_timer(session);
599 
600 		if (session->input)
601 			hidp_input_report(session, skb);
602 
603 		if (session->hid) {
604 			hidp_process_report(session, HID_INPUT_REPORT,
605 					    skb->data, skb->len, 1);
606 			BT_DBG("report len %d", skb->len);
607 		}
608 	} else {
609 		BT_DBG("Unsupported protocol header 0x%02x", hdr);
610 	}
611 
612 	kfree_skb(skb);
613 }
614 
615 static int hidp_send_frame(struct socket *sock, unsigned char *data, int len)
616 {
617 	struct kvec iv = { data, len };
618 	struct msghdr msg;
619 
620 	BT_DBG("sock %p data %p len %d", sock, data, len);
621 
622 	if (!len)
623 		return 0;
624 
625 	memset(&msg, 0, sizeof(msg));
626 
627 	return kernel_sendmsg(sock, &msg, &iv, 1, len);
628 }
629 
630 /* dequeue message from @transmit and send via @sock */
631 static void hidp_process_transmit(struct hidp_session *session,
632 				  struct sk_buff_head *transmit,
633 				  struct socket *sock)
634 {
635 	struct sk_buff *skb;
636 	int ret;
637 
638 	BT_DBG("session %p", session);
639 
640 	while ((skb = skb_dequeue(transmit))) {
641 		ret = hidp_send_frame(sock, skb->data, skb->len);
642 		if (ret == -EAGAIN) {
643 			skb_queue_head(transmit, skb);
644 			break;
645 		} else if (ret < 0) {
646 			hidp_session_terminate(session);
647 			kfree_skb(skb);
648 			break;
649 		}
650 
651 		hidp_set_timer(session);
652 		kfree_skb(skb);
653 	}
654 }
655 
656 static int hidp_setup_input(struct hidp_session *session,
657 				const struct hidp_connadd_req *req)
658 {
659 	struct input_dev *input;
660 	int i;
661 
662 	input = input_allocate_device();
663 	if (!input)
664 		return -ENOMEM;
665 
666 	session->input = input;
667 
668 	input_set_drvdata(input, session);
669 
670 	input->name = "Bluetooth HID Boot Protocol Device";
671 
672 	input->id.bustype = BUS_BLUETOOTH;
673 	input->id.vendor  = req->vendor;
674 	input->id.product = req->product;
675 	input->id.version = req->version;
676 
677 	if (req->subclass & 0x40) {
678 		set_bit(EV_KEY, input->evbit);
679 		set_bit(EV_LED, input->evbit);
680 		set_bit(EV_REP, input->evbit);
681 
682 		set_bit(LED_NUML,    input->ledbit);
683 		set_bit(LED_CAPSL,   input->ledbit);
684 		set_bit(LED_SCROLLL, input->ledbit);
685 		set_bit(LED_COMPOSE, input->ledbit);
686 		set_bit(LED_KANA,    input->ledbit);
687 
688 		for (i = 0; i < sizeof(hidp_keycode); i++)
689 			set_bit(hidp_keycode[i], input->keybit);
690 		clear_bit(0, input->keybit);
691 	}
692 
693 	if (req->subclass & 0x80) {
694 		input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
695 		input->keybit[BIT_WORD(BTN_MOUSE)] = BIT_MASK(BTN_LEFT) |
696 			BIT_MASK(BTN_RIGHT) | BIT_MASK(BTN_MIDDLE);
697 		input->relbit[0] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
698 		input->keybit[BIT_WORD(BTN_MOUSE)] |= BIT_MASK(BTN_SIDE) |
699 			BIT_MASK(BTN_EXTRA);
700 		input->relbit[0] |= BIT_MASK(REL_WHEEL);
701 	}
702 
703 	input->dev.parent = &session->conn->hcon->dev;
704 
705 	input->event = hidp_input_event;
706 
707 	return 0;
708 }
709 
710 static int hidp_open(struct hid_device *hid)
711 {
712 	return 0;
713 }
714 
715 static void hidp_close(struct hid_device *hid)
716 {
717 }
718 
719 static int hidp_parse(struct hid_device *hid)
720 {
721 	struct hidp_session *session = hid->driver_data;
722 
723 	return hid_parse_report(session->hid, session->rd_data,
724 			session->rd_size);
725 }
726 
727 static int hidp_start(struct hid_device *hid)
728 {
729 	return 0;
730 }
731 
732 static void hidp_stop(struct hid_device *hid)
733 {
734 	struct hidp_session *session = hid->driver_data;
735 
736 	skb_queue_purge(&session->ctrl_transmit);
737 	skb_queue_purge(&session->intr_transmit);
738 
739 	hid->claimed = 0;
740 }
741 
742 static const struct hid_ll_driver hidp_hid_driver = {
743 	.parse = hidp_parse,
744 	.start = hidp_start,
745 	.stop = hidp_stop,
746 	.open  = hidp_open,
747 	.close = hidp_close,
748 	.raw_request = hidp_raw_request,
749 	.output_report = hidp_output_report,
750 };
751 
752 /* This function sets up the hid device. It does not add it
753    to the HID system. That is done in hidp_add_connection(). */
754 static int hidp_setup_hid(struct hidp_session *session,
755 				const struct hidp_connadd_req *req)
756 {
757 	struct hid_device *hid;
758 	int err;
759 
760 	session->rd_data = memdup_user(req->rd_data, req->rd_size);
761 	if (IS_ERR(session->rd_data))
762 		return PTR_ERR(session->rd_data);
763 
764 	session->rd_size = req->rd_size;
765 
766 	hid = hid_allocate_device();
767 	if (IS_ERR(hid)) {
768 		err = PTR_ERR(hid);
769 		goto fault;
770 	}
771 
772 	session->hid = hid;
773 
774 	hid->driver_data = session;
775 
776 	hid->bus     = BUS_BLUETOOTH;
777 	hid->vendor  = req->vendor;
778 	hid->product = req->product;
779 	hid->version = req->version;
780 	hid->country = req->country;
781 
782 	strscpy(hid->name, req->name, sizeof(hid->name));
783 
784 	snprintf(hid->phys, sizeof(hid->phys), "%pMR",
785 		 &l2cap_pi(session->ctrl_sock->sk)->chan->src);
786 
787 	/* NOTE: Some device modules depend on the dst address being stored in
788 	 * uniq. Please be aware of this before making changes to this behavior.
789 	 */
790 	snprintf(hid->uniq, sizeof(hid->uniq), "%pMR",
791 		 &l2cap_pi(session->ctrl_sock->sk)->chan->dst);
792 
793 	hid->dev.parent = &session->conn->hcon->dev;
794 	hid->ll_driver = &hidp_hid_driver;
795 
796 	/* True if device is blocked in drivers/hid/hid-quirks.c */
797 	if (hid_ignore(hid)) {
798 		hid_destroy_device(session->hid);
799 		session->hid = NULL;
800 		return -ENODEV;
801 	}
802 
803 	return 0;
804 
805 fault:
806 	kfree(session->rd_data);
807 	session->rd_data = NULL;
808 
809 	return err;
810 }
811 
812 /* initialize session devices */
813 static int hidp_session_dev_init(struct hidp_session *session,
814 				 const struct hidp_connadd_req *req)
815 {
816 	int ret;
817 
818 	if (req->rd_size > 0) {
819 		ret = hidp_setup_hid(session, req);
820 		if (ret && ret != -ENODEV)
821 			return ret;
822 	}
823 
824 	if (!session->hid) {
825 		ret = hidp_setup_input(session, req);
826 		if (ret < 0)
827 			return ret;
828 	}
829 
830 	return 0;
831 }
832 
833 /* destroy session devices */
834 static void hidp_session_dev_destroy(struct hidp_session *session)
835 {
836 	if (session->hid)
837 		put_device(&session->hid->dev);
838 	else if (session->input)
839 		input_put_device(session->input);
840 
841 	kfree(session->rd_data);
842 	session->rd_data = NULL;
843 }
844 
845 /* add HID/input devices to their underlying bus systems */
846 static int hidp_session_dev_add(struct hidp_session *session)
847 {
848 	int ret;
849 
850 	/* Both HID and input systems drop a ref-count when unregistering the
851 	 * device but they don't take a ref-count when registering them. Work
852 	 * around this by explicitly taking a refcount during registration
853 	 * which is dropped automatically by unregistering the devices. */
854 
855 	if (session->hid) {
856 		ret = hid_add_device(session->hid);
857 		if (ret)
858 			return ret;
859 		get_device(&session->hid->dev);
860 	} else if (session->input) {
861 		ret = input_register_device(session->input);
862 		if (ret)
863 			return ret;
864 		input_get_device(session->input);
865 	}
866 
867 	return 0;
868 }
869 
870 /* remove HID/input devices from their bus systems */
871 static void hidp_session_dev_del(struct hidp_session *session)
872 {
873 	if (session->hid)
874 		hid_destroy_device(session->hid);
875 	else if (session->input)
876 		input_unregister_device(session->input);
877 }
878 
879 /*
880  * Asynchronous device registration
881  * HID device drivers might want to perform I/O during initialization to
882  * detect device types. Therefore, call device registration in a separate
883  * worker so the HIDP thread can schedule I/O operations.
884  * Note that this must be called after the worker thread was initialized
885  * successfully. This will then add the devices and increase session state
886  * on success, otherwise it will terminate the session thread.
887  */
888 static void hidp_session_dev_work(struct work_struct *work)
889 {
890 	struct hidp_session *session = container_of(work,
891 						    struct hidp_session,
892 						    dev_init);
893 	int ret;
894 
895 	ret = hidp_session_dev_add(session);
896 	if (!ret)
897 		atomic_inc(&session->state);
898 	else
899 		hidp_session_terminate(session);
900 }
901 
902 /*
903  * Create new session object
904  * Allocate session object, initialize static fields, copy input data into the
905  * object and take a reference to all sub-objects.
906  * This returns 0 on success and puts a pointer to the new session object in
907  * \out. Otherwise, an error code is returned.
908  * The new session object has an initial ref-count of 1.
909  */
910 static int hidp_session_new(struct hidp_session **out, const bdaddr_t *bdaddr,
911 			    struct socket *ctrl_sock,
912 			    struct socket *intr_sock,
913 			    const struct hidp_connadd_req *req,
914 			    struct l2cap_conn *conn)
915 {
916 	struct hidp_session *session;
917 	int ret;
918 	struct bt_sock *ctrl, *intr;
919 
920 	ctrl = bt_sk(ctrl_sock->sk);
921 	intr = bt_sk(intr_sock->sk);
922 
923 	session = kzalloc(sizeof(*session), GFP_KERNEL);
924 	if (!session)
925 		return -ENOMEM;
926 
927 	/* object and runtime management */
928 	kref_init(&session->ref);
929 	atomic_set(&session->state, HIDP_SESSION_IDLING);
930 	init_waitqueue_head(&session->state_queue);
931 	session->flags = req->flags & BIT(HIDP_BLUETOOTH_VENDOR_ID);
932 
933 	/* connection management */
934 	bacpy(&session->bdaddr, bdaddr);
935 	session->conn = l2cap_conn_get(conn);
936 	session->user.probe = hidp_session_probe;
937 	session->user.remove = hidp_session_remove;
938 	INIT_LIST_HEAD(&session->user.list);
939 	session->ctrl_sock = ctrl_sock;
940 	session->intr_sock = intr_sock;
941 	skb_queue_head_init(&session->ctrl_transmit);
942 	skb_queue_head_init(&session->intr_transmit);
943 	session->ctrl_mtu = min_t(uint, l2cap_pi(ctrl)->chan->omtu,
944 					l2cap_pi(ctrl)->chan->imtu);
945 	session->intr_mtu = min_t(uint, l2cap_pi(intr)->chan->omtu,
946 					l2cap_pi(intr)->chan->imtu);
947 	session->idle_to = req->idle_to;
948 
949 	/* device management */
950 	INIT_WORK(&session->dev_init, hidp_session_dev_work);
951 	timer_setup(&session->timer, hidp_idle_timeout, 0);
952 
953 	/* session data */
954 	mutex_init(&session->report_mutex);
955 	init_waitqueue_head(&session->report_queue);
956 
957 	ret = hidp_session_dev_init(session, req);
958 	if (ret)
959 		goto err_free;
960 
961 	get_file(session->intr_sock->file);
962 	get_file(session->ctrl_sock->file);
963 	*out = session;
964 	return 0;
965 
966 err_free:
967 	l2cap_conn_put(session->conn);
968 	kfree(session);
969 	return ret;
970 }
971 
972 /* increase ref-count of the given session by one */
973 static void hidp_session_get(struct hidp_session *session)
974 {
975 	kref_get(&session->ref);
976 }
977 
978 /* release callback */
979 static void session_free(struct kref *ref)
980 {
981 	struct hidp_session *session = container_of(ref, struct hidp_session,
982 						    ref);
983 
984 	hidp_session_dev_destroy(session);
985 	skb_queue_purge(&session->ctrl_transmit);
986 	skb_queue_purge(&session->intr_transmit);
987 	fput(session->intr_sock->file);
988 	fput(session->ctrl_sock->file);
989 	l2cap_conn_put(session->conn);
990 	kfree(session);
991 }
992 
993 /* decrease ref-count of the given session by one */
994 static void hidp_session_put(struct hidp_session *session)
995 {
996 	kref_put(&session->ref, session_free);
997 }
998 
999 /*
1000  * Search the list of active sessions for a session with target address
1001  * \bdaddr. You must hold at least a read-lock on \hidp_session_sem. As long as
1002  * you do not release this lock, the session objects cannot vanish and you can
1003  * safely take a reference to the session yourself.
1004  */
1005 static struct hidp_session *__hidp_session_find(const bdaddr_t *bdaddr)
1006 {
1007 	struct hidp_session *session;
1008 
1009 	list_for_each_entry(session, &hidp_session_list, list) {
1010 		if (!bacmp(bdaddr, &session->bdaddr))
1011 			return session;
1012 	}
1013 
1014 	return NULL;
1015 }
1016 
1017 /*
1018  * Same as __hidp_session_find() but no locks must be held. This also takes a
1019  * reference of the returned session (if non-NULL) so you must drop this
1020  * reference if you no longer use the object.
1021  */
1022 static struct hidp_session *hidp_session_find(const bdaddr_t *bdaddr)
1023 {
1024 	struct hidp_session *session;
1025 
1026 	down_read(&hidp_session_sem);
1027 
1028 	session = __hidp_session_find(bdaddr);
1029 	if (session)
1030 		hidp_session_get(session);
1031 
1032 	up_read(&hidp_session_sem);
1033 
1034 	return session;
1035 }
1036 
1037 /*
1038  * Start session synchronously
1039  * This starts a session thread and waits until initialization
1040  * is done or returns an error if it couldn't be started.
1041  * If this returns 0 the session thread is up and running. You must call
1042  * hipd_session_stop_sync() before deleting any runtime resources.
1043  */
1044 static int hidp_session_start_sync(struct hidp_session *session)
1045 {
1046 	unsigned int vendor, product;
1047 
1048 	if (session->hid) {
1049 		vendor  = session->hid->vendor;
1050 		product = session->hid->product;
1051 	} else if (session->input) {
1052 		vendor  = session->input->id.vendor;
1053 		product = session->input->id.product;
1054 	} else {
1055 		vendor = 0x0000;
1056 		product = 0x0000;
1057 	}
1058 
1059 	session->task = kthread_run(hidp_session_thread, session,
1060 				    "khidpd_%04x%04x", vendor, product);
1061 	if (IS_ERR(session->task))
1062 		return PTR_ERR(session->task);
1063 
1064 	while (atomic_read(&session->state) <= HIDP_SESSION_IDLING)
1065 		wait_event(session->state_queue,
1066 			   atomic_read(&session->state) > HIDP_SESSION_IDLING);
1067 
1068 	return 0;
1069 }
1070 
1071 /*
1072  * Terminate session thread
1073  * Wake up session thread and notify it to stop. This is asynchronous and
1074  * returns immediately. Call this whenever a runtime error occurs and you want
1075  * the session to stop.
1076  * Note: wake_up_interruptible() performs any necessary memory-barriers for us.
1077  */
1078 static void hidp_session_terminate(struct hidp_session *session)
1079 {
1080 	atomic_inc(&session->terminate);
1081 	/*
1082 	 * See the comment preceding the call to wait_woken()
1083 	 * in hidp_session_run().
1084 	 */
1085 	wake_up_interruptible(&hidp_session_wq);
1086 }
1087 
1088 /*
1089  * Probe HIDP session
1090  * This is called from the l2cap_conn core when our l2cap_user object is bound
1091  * to the hci-connection. We get the session via the \user object and can now
1092  * start the session thread, link it into the global session list and
1093  * schedule HID/input device registration.
1094  * The global session-list owns its own reference to the session object so you
1095  * can drop your own reference after registering the l2cap_user object.
1096  */
1097 static int hidp_session_probe(struct l2cap_conn *conn,
1098 			      struct l2cap_user *user)
1099 {
1100 	struct hidp_session *session = container_of(user,
1101 						    struct hidp_session,
1102 						    user);
1103 	struct hidp_session *s;
1104 	int ret;
1105 
1106 	down_write(&hidp_session_sem);
1107 
1108 	/* check that no other session for this device exists */
1109 	s = __hidp_session_find(&session->bdaddr);
1110 	if (s) {
1111 		ret = -EEXIST;
1112 		goto out_unlock;
1113 	}
1114 
1115 	if (session->input) {
1116 		ret = hidp_session_dev_add(session);
1117 		if (ret)
1118 			goto out_unlock;
1119 	}
1120 
1121 	ret = hidp_session_start_sync(session);
1122 	if (ret)
1123 		goto out_del;
1124 
1125 	/* HID device registration is async to allow I/O during probe */
1126 	if (session->input)
1127 		atomic_inc(&session->state);
1128 	else
1129 		schedule_work(&session->dev_init);
1130 
1131 	hidp_session_get(session);
1132 	list_add(&session->list, &hidp_session_list);
1133 	ret = 0;
1134 	goto out_unlock;
1135 
1136 out_del:
1137 	if (session->input)
1138 		hidp_session_dev_del(session);
1139 out_unlock:
1140 	up_write(&hidp_session_sem);
1141 	return ret;
1142 }
1143 
1144 /*
1145  * Remove HIDP session
1146  * Called from the l2cap_conn core when either we explicitly unregistered
1147  * the l2cap_user object or if the underlying connection is shut down.
1148  * We signal the hidp-session thread to shut down, unregister the HID/input
1149  * devices and unlink the session from the global list.
1150  * This drops the reference to the session that is owned by the global
1151  * session-list.
1152  * Note: We _must_ not synchronosly wait for the session-thread to shut down.
1153  * This is, because the session-thread might be waiting for an HCI lock that is
1154  * held while we are called. Therefore, we only unregister the devices and
1155  * notify the session-thread to terminate. The thread itself owns a reference
1156  * to the session object so it can safely shut down.
1157  */
1158 static void hidp_session_remove(struct l2cap_conn *conn,
1159 				struct l2cap_user *user)
1160 {
1161 	struct hidp_session *session = container_of(user,
1162 						    struct hidp_session,
1163 						    user);
1164 
1165 	down_write(&hidp_session_sem);
1166 
1167 	hidp_session_terminate(session);
1168 
1169 	cancel_work_sync(&session->dev_init);
1170 	if (session->input ||
1171 	    atomic_read(&session->state) > HIDP_SESSION_PREPARING)
1172 		hidp_session_dev_del(session);
1173 
1174 	list_del(&session->list);
1175 
1176 	up_write(&hidp_session_sem);
1177 
1178 	hidp_session_put(session);
1179 }
1180 
1181 /*
1182  * Session Worker
1183  * This performs the actual main-loop of the HIDP worker. We first check
1184  * whether the underlying connection is still alive, then parse all pending
1185  * messages and finally send all outstanding messages.
1186  */
1187 static void hidp_session_run(struct hidp_session *session)
1188 {
1189 	struct sock *ctrl_sk = session->ctrl_sock->sk;
1190 	struct sock *intr_sk = session->intr_sock->sk;
1191 	struct sk_buff *skb;
1192 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
1193 
1194 	add_wait_queue(&hidp_session_wq, &wait);
1195 	for (;;) {
1196 		/*
1197 		 * This thread can be woken up two ways:
1198 		 *  - You call hidp_session_terminate() which sets the
1199 		 *    session->terminate flag and wakes this thread up.
1200 		 *  - Via modifying the socket state of ctrl/intr_sock. This
1201 		 *    thread is woken up by ->sk_state_changed().
1202 		 */
1203 
1204 		if (atomic_read(&session->terminate))
1205 			break;
1206 
1207 		if (ctrl_sk->sk_state != BT_CONNECTED ||
1208 		    intr_sk->sk_state != BT_CONNECTED)
1209 			break;
1210 
1211 		/* parse incoming intr-skbs */
1212 		while ((skb = skb_dequeue(&intr_sk->sk_receive_queue))) {
1213 			skb_orphan(skb);
1214 			if (!skb_linearize(skb))
1215 				hidp_recv_intr_frame(session, skb);
1216 			else
1217 				kfree_skb(skb);
1218 		}
1219 
1220 		/* send pending intr-skbs */
1221 		hidp_process_transmit(session, &session->intr_transmit,
1222 				      session->intr_sock);
1223 
1224 		/* parse incoming ctrl-skbs */
1225 		while ((skb = skb_dequeue(&ctrl_sk->sk_receive_queue))) {
1226 			skb_orphan(skb);
1227 			if (!skb_linearize(skb))
1228 				hidp_recv_ctrl_frame(session, skb);
1229 			else
1230 				kfree_skb(skb);
1231 		}
1232 
1233 		/* send pending ctrl-skbs */
1234 		hidp_process_transmit(session, &session->ctrl_transmit,
1235 				      session->ctrl_sock);
1236 
1237 		/*
1238 		 * wait_woken() performs the necessary memory barriers
1239 		 * for us; see the header comment for this primitive.
1240 		 */
1241 		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
1242 	}
1243 	remove_wait_queue(&hidp_session_wq, &wait);
1244 
1245 	atomic_inc(&session->terminate);
1246 }
1247 
1248 static int hidp_session_wake_function(wait_queue_entry_t *wait,
1249 				      unsigned int mode,
1250 				      int sync, void *key)
1251 {
1252 	wake_up_interruptible(&hidp_session_wq);
1253 	return false;
1254 }
1255 
1256 /*
1257  * HIDP session thread
1258  * This thread runs the I/O for a single HIDP session. Startup is synchronous
1259  * which allows us to take references to ourself here instead of doing that in
1260  * the caller.
1261  * When we are ready to run we notify the caller and call hidp_session_run().
1262  */
1263 static int hidp_session_thread(void *arg)
1264 {
1265 	struct hidp_session *session = arg;
1266 	DEFINE_WAIT_FUNC(ctrl_wait, hidp_session_wake_function);
1267 	DEFINE_WAIT_FUNC(intr_wait, hidp_session_wake_function);
1268 
1269 	BT_DBG("session %p", session);
1270 
1271 	/* initialize runtime environment */
1272 	hidp_session_get(session);
1273 	__module_get(THIS_MODULE);
1274 	set_user_nice(current, -15);
1275 	hidp_set_timer(session);
1276 
1277 	add_wait_queue(sk_sleep(session->ctrl_sock->sk), &ctrl_wait);
1278 	add_wait_queue(sk_sleep(session->intr_sock->sk), &intr_wait);
1279 	/* This memory barrier is paired with wq_has_sleeper(). See
1280 	 * sock_poll_wait() for more information why this is needed. */
1281 	smp_mb__before_atomic();
1282 
1283 	/* notify synchronous startup that we're ready */
1284 	atomic_inc(&session->state);
1285 	wake_up(&session->state_queue);
1286 
1287 	/* run session */
1288 	hidp_session_run(session);
1289 
1290 	/* cleanup runtime environment */
1291 	remove_wait_queue(sk_sleep(session->intr_sock->sk), &intr_wait);
1292 	remove_wait_queue(sk_sleep(session->ctrl_sock->sk), &ctrl_wait);
1293 	wake_up_interruptible(&session->report_queue);
1294 	hidp_del_timer(session);
1295 
1296 	/*
1297 	 * If we stopped ourself due to any internal signal, we should try to
1298 	 * unregister our own session here to avoid having it linger until the
1299 	 * parent l2cap_conn dies or user-space cleans it up.
1300 	 * This does not deadlock as we don't do any synchronous shutdown.
1301 	 * Instead, this call has the same semantics as if user-space tried to
1302 	 * delete the session.
1303 	 */
1304 	l2cap_unregister_user(session->conn, &session->user);
1305 	hidp_session_put(session);
1306 
1307 	module_put_and_kthread_exit(0);
1308 	return 0;
1309 }
1310 
1311 static int hidp_verify_sockets(struct socket *ctrl_sock,
1312 			       struct socket *intr_sock)
1313 {
1314 	struct l2cap_chan *ctrl_chan, *intr_chan;
1315 	struct bt_sock *ctrl, *intr;
1316 	struct hidp_session *session;
1317 
1318 	if (!l2cap_is_socket(ctrl_sock) || !l2cap_is_socket(intr_sock))
1319 		return -EINVAL;
1320 
1321 	ctrl_chan = l2cap_pi(ctrl_sock->sk)->chan;
1322 	intr_chan = l2cap_pi(intr_sock->sk)->chan;
1323 
1324 	if (bacmp(&ctrl_chan->src, &intr_chan->src) ||
1325 	    bacmp(&ctrl_chan->dst, &intr_chan->dst))
1326 		return -ENOTUNIQ;
1327 
1328 	ctrl = bt_sk(ctrl_sock->sk);
1329 	intr = bt_sk(intr_sock->sk);
1330 
1331 	if (ctrl->sk.sk_state != BT_CONNECTED ||
1332 	    intr->sk.sk_state != BT_CONNECTED)
1333 		return -EBADFD;
1334 
1335 	/* early session check, we check again during session registration */
1336 	session = hidp_session_find(&ctrl_chan->dst);
1337 	if (session) {
1338 		hidp_session_put(session);
1339 		return -EEXIST;
1340 	}
1341 
1342 	return 0;
1343 }
1344 
1345 int hidp_connection_add(const struct hidp_connadd_req *req,
1346 			struct socket *ctrl_sock,
1347 			struct socket *intr_sock)
1348 {
1349 	u32 valid_flags = BIT(HIDP_VIRTUAL_CABLE_UNPLUG) |
1350 			  BIT(HIDP_BOOT_PROTOCOL_MODE);
1351 	struct hidp_session *session;
1352 	struct l2cap_conn *conn;
1353 	struct l2cap_chan *chan;
1354 	int ret;
1355 
1356 	ret = hidp_verify_sockets(ctrl_sock, intr_sock);
1357 	if (ret)
1358 		return ret;
1359 
1360 	if (req->flags & ~valid_flags)
1361 		return -EINVAL;
1362 
1363 	chan = l2cap_pi(ctrl_sock->sk)->chan;
1364 	conn = NULL;
1365 	l2cap_chan_lock(chan);
1366 	if (chan->conn)
1367 		conn = l2cap_conn_get(chan->conn);
1368 	l2cap_chan_unlock(chan);
1369 
1370 	if (!conn)
1371 		return -EBADFD;
1372 
1373 	ret = hidp_session_new(&session, &chan->dst, ctrl_sock,
1374 			       intr_sock, req, conn);
1375 	if (ret)
1376 		goto out_conn;
1377 
1378 	ret = l2cap_register_user(conn, &session->user);
1379 	if (ret)
1380 		goto out_session;
1381 
1382 	ret = 0;
1383 
1384 out_session:
1385 	hidp_session_put(session);
1386 out_conn:
1387 	l2cap_conn_put(conn);
1388 	return ret;
1389 }
1390 
1391 int hidp_connection_del(struct hidp_conndel_req *req)
1392 {
1393 	u32 valid_flags = BIT(HIDP_VIRTUAL_CABLE_UNPLUG);
1394 	struct hidp_session *session;
1395 
1396 	if (req->flags & ~valid_flags)
1397 		return -EINVAL;
1398 
1399 	session = hidp_session_find(&req->bdaddr);
1400 	if (!session)
1401 		return -ENOENT;
1402 
1403 	if (req->flags & BIT(HIDP_VIRTUAL_CABLE_UNPLUG))
1404 		hidp_send_ctrl_message(session,
1405 				       HIDP_TRANS_HID_CONTROL |
1406 				         HIDP_CTRL_VIRTUAL_CABLE_UNPLUG,
1407 				       NULL, 0);
1408 	else
1409 		l2cap_unregister_user(session->conn, &session->user);
1410 
1411 	hidp_session_put(session);
1412 
1413 	return 0;
1414 }
1415 
1416 int hidp_get_connlist(struct hidp_connlist_req *req)
1417 {
1418 	struct hidp_session *session;
1419 	int err = 0, n = 0;
1420 
1421 	BT_DBG("");
1422 
1423 	down_read(&hidp_session_sem);
1424 
1425 	list_for_each_entry(session, &hidp_session_list, list) {
1426 		struct hidp_conninfo ci;
1427 
1428 		hidp_copy_session(session, &ci);
1429 
1430 		if (copy_to_user(req->ci, &ci, sizeof(ci))) {
1431 			err = -EFAULT;
1432 			break;
1433 		}
1434 
1435 		if (++n >= req->cnum)
1436 			break;
1437 
1438 		req->ci++;
1439 	}
1440 	req->cnum = n;
1441 
1442 	up_read(&hidp_session_sem);
1443 	return err;
1444 }
1445 
1446 int hidp_get_conninfo(struct hidp_conninfo *ci)
1447 {
1448 	struct hidp_session *session;
1449 
1450 	session = hidp_session_find(&ci->bdaddr);
1451 	if (session) {
1452 		hidp_copy_session(session, ci);
1453 		hidp_session_put(session);
1454 	}
1455 
1456 	return session ? 0 : -ENOENT;
1457 }
1458 
1459 static int __init hidp_init(void)
1460 {
1461 	BT_INFO("HIDP (Human Interface Emulation) ver %s", VERSION);
1462 
1463 	return hidp_init_sockets();
1464 }
1465 
1466 static void __exit hidp_exit(void)
1467 {
1468 	hidp_cleanup_sockets();
1469 }
1470 
1471 module_init(hidp_init);
1472 module_exit(hidp_exit);
1473 
1474 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
1475 MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>");
1476 MODULE_DESCRIPTION("Bluetooth HIDP ver " VERSION);
1477 MODULE_VERSION(VERSION);
1478 MODULE_LICENSE("GPL");
1479 MODULE_ALIAS("bt-proto-6");
1480