xref: /linux/net/bluetooth/hidp/core.c (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
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 			strlcpy(ci->name, session->input->name, 128);
87 		else
88 			strlcpy(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 		strlcpy(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(&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 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 EXPORT_SYMBOL_GPL(hidp_hid_driver);
752 
753 /* This function sets up the hid device. It does not add it
754    to the HID system. That is done in hidp_add_connection(). */
755 static int hidp_setup_hid(struct hidp_session *session,
756 				const struct hidp_connadd_req *req)
757 {
758 	struct hid_device *hid;
759 	int err;
760 
761 	session->rd_data = memdup_user(req->rd_data, req->rd_size);
762 	if (IS_ERR(session->rd_data))
763 		return PTR_ERR(session->rd_data);
764 
765 	session->rd_size = req->rd_size;
766 
767 	hid = hid_allocate_device();
768 	if (IS_ERR(hid)) {
769 		err = PTR_ERR(hid);
770 		goto fault;
771 	}
772 
773 	session->hid = hid;
774 
775 	hid->driver_data = session;
776 
777 	hid->bus     = BUS_BLUETOOTH;
778 	hid->vendor  = req->vendor;
779 	hid->product = req->product;
780 	hid->version = req->version;
781 	hid->country = req->country;
782 
783 	strscpy(hid->name, req->name, sizeof(hid->name));
784 
785 	snprintf(hid->phys, sizeof(hid->phys), "%pMR",
786 		 &l2cap_pi(session->ctrl_sock->sk)->chan->src);
787 
788 	/* NOTE: Some device modules depend on the dst address being stored in
789 	 * uniq. Please be aware of this before making changes to this behavior.
790 	 */
791 	snprintf(hid->uniq, sizeof(hid->uniq), "%pMR",
792 		 &l2cap_pi(session->ctrl_sock->sk)->chan->dst);
793 
794 	hid->dev.parent = &session->conn->hcon->dev;
795 	hid->ll_driver = &hidp_hid_driver;
796 
797 	/* True if device is blocked in drivers/hid/hid-quirks.c */
798 	if (hid_ignore(hid)) {
799 		hid_destroy_device(session->hid);
800 		session->hid = NULL;
801 		return -ENODEV;
802 	}
803 
804 	return 0;
805 
806 fault:
807 	kfree(session->rd_data);
808 	session->rd_data = NULL;
809 
810 	return err;
811 }
812 
813 /* initialize session devices */
814 static int hidp_session_dev_init(struct hidp_session *session,
815 				 const struct hidp_connadd_req *req)
816 {
817 	int ret;
818 
819 	if (req->rd_size > 0) {
820 		ret = hidp_setup_hid(session, req);
821 		if (ret && ret != -ENODEV)
822 			return ret;
823 	}
824 
825 	if (!session->hid) {
826 		ret = hidp_setup_input(session, req);
827 		if (ret < 0)
828 			return ret;
829 	}
830 
831 	return 0;
832 }
833 
834 /* destroy session devices */
835 static void hidp_session_dev_destroy(struct hidp_session *session)
836 {
837 	if (session->hid)
838 		put_device(&session->hid->dev);
839 	else if (session->input)
840 		input_put_device(session->input);
841 
842 	kfree(session->rd_data);
843 	session->rd_data = NULL;
844 }
845 
846 /* add HID/input devices to their underlying bus systems */
847 static int hidp_session_dev_add(struct hidp_session *session)
848 {
849 	int ret;
850 
851 	/* Both HID and input systems drop a ref-count when unregistering the
852 	 * device but they don't take a ref-count when registering them. Work
853 	 * around this by explicitly taking a refcount during registration
854 	 * which is dropped automatically by unregistering the devices. */
855 
856 	if (session->hid) {
857 		ret = hid_add_device(session->hid);
858 		if (ret)
859 			return ret;
860 		get_device(&session->hid->dev);
861 	} else if (session->input) {
862 		ret = input_register_device(session->input);
863 		if (ret)
864 			return ret;
865 		input_get_device(session->input);
866 	}
867 
868 	return 0;
869 }
870 
871 /* remove HID/input devices from their bus systems */
872 static void hidp_session_dev_del(struct hidp_session *session)
873 {
874 	if (session->hid)
875 		hid_destroy_device(session->hid);
876 	else if (session->input)
877 		input_unregister_device(session->input);
878 }
879 
880 /*
881  * Asynchronous device registration
882  * HID device drivers might want to perform I/O during initialization to
883  * detect device types. Therefore, call device registration in a separate
884  * worker so the HIDP thread can schedule I/O operations.
885  * Note that this must be called after the worker thread was initialized
886  * successfully. This will then add the devices and increase session state
887  * on success, otherwise it will terminate the session thread.
888  */
889 static void hidp_session_dev_work(struct work_struct *work)
890 {
891 	struct hidp_session *session = container_of(work,
892 						    struct hidp_session,
893 						    dev_init);
894 	int ret;
895 
896 	ret = hidp_session_dev_add(session);
897 	if (!ret)
898 		atomic_inc(&session->state);
899 	else
900 		hidp_session_terminate(session);
901 }
902 
903 /*
904  * Create new session object
905  * Allocate session object, initialize static fields, copy input data into the
906  * object and take a reference to all sub-objects.
907  * This returns 0 on success and puts a pointer to the new session object in
908  * \out. Otherwise, an error code is returned.
909  * The new session object has an initial ref-count of 1.
910  */
911 static int hidp_session_new(struct hidp_session **out, const bdaddr_t *bdaddr,
912 			    struct socket *ctrl_sock,
913 			    struct socket *intr_sock,
914 			    const struct hidp_connadd_req *req,
915 			    struct l2cap_conn *conn)
916 {
917 	struct hidp_session *session;
918 	int ret;
919 	struct bt_sock *ctrl, *intr;
920 
921 	ctrl = bt_sk(ctrl_sock->sk);
922 	intr = bt_sk(intr_sock->sk);
923 
924 	session = kzalloc(sizeof(*session), GFP_KERNEL);
925 	if (!session)
926 		return -ENOMEM;
927 
928 	/* object and runtime management */
929 	kref_init(&session->ref);
930 	atomic_set(&session->state, HIDP_SESSION_IDLING);
931 	init_waitqueue_head(&session->state_queue);
932 	session->flags = req->flags & BIT(HIDP_BLUETOOTH_VENDOR_ID);
933 
934 	/* connection management */
935 	bacpy(&session->bdaddr, bdaddr);
936 	session->conn = l2cap_conn_get(conn);
937 	session->user.probe = hidp_session_probe;
938 	session->user.remove = hidp_session_remove;
939 	INIT_LIST_HEAD(&session->user.list);
940 	session->ctrl_sock = ctrl_sock;
941 	session->intr_sock = intr_sock;
942 	skb_queue_head_init(&session->ctrl_transmit);
943 	skb_queue_head_init(&session->intr_transmit);
944 	session->ctrl_mtu = min_t(uint, l2cap_pi(ctrl)->chan->omtu,
945 					l2cap_pi(ctrl)->chan->imtu);
946 	session->intr_mtu = min_t(uint, l2cap_pi(intr)->chan->omtu,
947 					l2cap_pi(intr)->chan->imtu);
948 	session->idle_to = req->idle_to;
949 
950 	/* device management */
951 	INIT_WORK(&session->dev_init, hidp_session_dev_work);
952 	timer_setup(&session->timer, hidp_idle_timeout, 0);
953 
954 	/* session data */
955 	mutex_init(&session->report_mutex);
956 	init_waitqueue_head(&session->report_queue);
957 
958 	ret = hidp_session_dev_init(session, req);
959 	if (ret)
960 		goto err_free;
961 
962 	get_file(session->intr_sock->file);
963 	get_file(session->ctrl_sock->file);
964 	*out = session;
965 	return 0;
966 
967 err_free:
968 	l2cap_conn_put(session->conn);
969 	kfree(session);
970 	return ret;
971 }
972 
973 /* increase ref-count of the given session by one */
974 static void hidp_session_get(struct hidp_session *session)
975 {
976 	kref_get(&session->ref);
977 }
978 
979 /* release callback */
980 static void session_free(struct kref *ref)
981 {
982 	struct hidp_session *session = container_of(ref, struct hidp_session,
983 						    ref);
984 
985 	hidp_session_dev_destroy(session);
986 	skb_queue_purge(&session->ctrl_transmit);
987 	skb_queue_purge(&session->intr_transmit);
988 	fput(session->intr_sock->file);
989 	fput(session->ctrl_sock->file);
990 	l2cap_conn_put(session->conn);
991 	kfree(session);
992 }
993 
994 /* decrease ref-count of the given session by one */
995 static void hidp_session_put(struct hidp_session *session)
996 {
997 	kref_put(&session->ref, session_free);
998 }
999 
1000 /*
1001  * Search the list of active sessions for a session with target address
1002  * \bdaddr. You must hold at least a read-lock on \hidp_session_sem. As long as
1003  * you do not release this lock, the session objects cannot vanish and you can
1004  * safely take a reference to the session yourself.
1005  */
1006 static struct hidp_session *__hidp_session_find(const bdaddr_t *bdaddr)
1007 {
1008 	struct hidp_session *session;
1009 
1010 	list_for_each_entry(session, &hidp_session_list, list) {
1011 		if (!bacmp(bdaddr, &session->bdaddr))
1012 			return session;
1013 	}
1014 
1015 	return NULL;
1016 }
1017 
1018 /*
1019  * Same as __hidp_session_find() but no locks must be held. This also takes a
1020  * reference of the returned session (if non-NULL) so you must drop this
1021  * reference if you no longer use the object.
1022  */
1023 static struct hidp_session *hidp_session_find(const bdaddr_t *bdaddr)
1024 {
1025 	struct hidp_session *session;
1026 
1027 	down_read(&hidp_session_sem);
1028 
1029 	session = __hidp_session_find(bdaddr);
1030 	if (session)
1031 		hidp_session_get(session);
1032 
1033 	up_read(&hidp_session_sem);
1034 
1035 	return session;
1036 }
1037 
1038 /*
1039  * Start session synchronously
1040  * This starts a session thread and waits until initialization
1041  * is done or returns an error if it couldn't be started.
1042  * If this returns 0 the session thread is up and running. You must call
1043  * hipd_session_stop_sync() before deleting any runtime resources.
1044  */
1045 static int hidp_session_start_sync(struct hidp_session *session)
1046 {
1047 	unsigned int vendor, product;
1048 
1049 	if (session->hid) {
1050 		vendor  = session->hid->vendor;
1051 		product = session->hid->product;
1052 	} else if (session->input) {
1053 		vendor  = session->input->id.vendor;
1054 		product = session->input->id.product;
1055 	} else {
1056 		vendor = 0x0000;
1057 		product = 0x0000;
1058 	}
1059 
1060 	session->task = kthread_run(hidp_session_thread, session,
1061 				    "khidpd_%04x%04x", vendor, product);
1062 	if (IS_ERR(session->task))
1063 		return PTR_ERR(session->task);
1064 
1065 	while (atomic_read(&session->state) <= HIDP_SESSION_IDLING)
1066 		wait_event(session->state_queue,
1067 			   atomic_read(&session->state) > HIDP_SESSION_IDLING);
1068 
1069 	return 0;
1070 }
1071 
1072 /*
1073  * Terminate session thread
1074  * Wake up session thread and notify it to stop. This is asynchronous and
1075  * returns immediately. Call this whenever a runtime error occurs and you want
1076  * the session to stop.
1077  * Note: wake_up_interruptible() performs any necessary memory-barriers for us.
1078  */
1079 static void hidp_session_terminate(struct hidp_session *session)
1080 {
1081 	atomic_inc(&session->terminate);
1082 	/*
1083 	 * See the comment preceding the call to wait_woken()
1084 	 * in hidp_session_run().
1085 	 */
1086 	wake_up_interruptible(&hidp_session_wq);
1087 }
1088 
1089 /*
1090  * Probe HIDP session
1091  * This is called from the l2cap_conn core when our l2cap_user object is bound
1092  * to the hci-connection. We get the session via the \user object and can now
1093  * start the session thread, link it into the global session list and
1094  * schedule HID/input device registration.
1095  * The global session-list owns its own reference to the session object so you
1096  * can drop your own reference after registering the l2cap_user object.
1097  */
1098 static int hidp_session_probe(struct l2cap_conn *conn,
1099 			      struct l2cap_user *user)
1100 {
1101 	struct hidp_session *session = container_of(user,
1102 						    struct hidp_session,
1103 						    user);
1104 	struct hidp_session *s;
1105 	int ret;
1106 
1107 	down_write(&hidp_session_sem);
1108 
1109 	/* check that no other session for this device exists */
1110 	s = __hidp_session_find(&session->bdaddr);
1111 	if (s) {
1112 		ret = -EEXIST;
1113 		goto out_unlock;
1114 	}
1115 
1116 	if (session->input) {
1117 		ret = hidp_session_dev_add(session);
1118 		if (ret)
1119 			goto out_unlock;
1120 	}
1121 
1122 	ret = hidp_session_start_sync(session);
1123 	if (ret)
1124 		goto out_del;
1125 
1126 	/* HID device registration is async to allow I/O during probe */
1127 	if (session->input)
1128 		atomic_inc(&session->state);
1129 	else
1130 		schedule_work(&session->dev_init);
1131 
1132 	hidp_session_get(session);
1133 	list_add(&session->list, &hidp_session_list);
1134 	ret = 0;
1135 	goto out_unlock;
1136 
1137 out_del:
1138 	if (session->input)
1139 		hidp_session_dev_del(session);
1140 out_unlock:
1141 	up_write(&hidp_session_sem);
1142 	return ret;
1143 }
1144 
1145 /*
1146  * Remove HIDP session
1147  * Called from the l2cap_conn core when either we explicitly unregistered
1148  * the l2cap_user object or if the underlying connection is shut down.
1149  * We signal the hidp-session thread to shut down, unregister the HID/input
1150  * devices and unlink the session from the global list.
1151  * This drops the reference to the session that is owned by the global
1152  * session-list.
1153  * Note: We _must_ not synchronosly wait for the session-thread to shut down.
1154  * This is, because the session-thread might be waiting for an HCI lock that is
1155  * held while we are called. Therefore, we only unregister the devices and
1156  * notify the session-thread to terminate. The thread itself owns a reference
1157  * to the session object so it can safely shut down.
1158  */
1159 static void hidp_session_remove(struct l2cap_conn *conn,
1160 				struct l2cap_user *user)
1161 {
1162 	struct hidp_session *session = container_of(user,
1163 						    struct hidp_session,
1164 						    user);
1165 
1166 	down_write(&hidp_session_sem);
1167 
1168 	hidp_session_terminate(session);
1169 
1170 	cancel_work_sync(&session->dev_init);
1171 	if (session->input ||
1172 	    atomic_read(&session->state) > HIDP_SESSION_PREPARING)
1173 		hidp_session_dev_del(session);
1174 
1175 	list_del(&session->list);
1176 
1177 	up_write(&hidp_session_sem);
1178 
1179 	hidp_session_put(session);
1180 }
1181 
1182 /*
1183  * Session Worker
1184  * This performs the actual main-loop of the HIDP worker. We first check
1185  * whether the underlying connection is still alive, then parse all pending
1186  * messages and finally send all outstanding messages.
1187  */
1188 static void hidp_session_run(struct hidp_session *session)
1189 {
1190 	struct sock *ctrl_sk = session->ctrl_sock->sk;
1191 	struct sock *intr_sk = session->intr_sock->sk;
1192 	struct sk_buff *skb;
1193 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
1194 
1195 	add_wait_queue(&hidp_session_wq, &wait);
1196 	for (;;) {
1197 		/*
1198 		 * This thread can be woken up two ways:
1199 		 *  - You call hidp_session_terminate() which sets the
1200 		 *    session->terminate flag and wakes this thread up.
1201 		 *  - Via modifying the socket state of ctrl/intr_sock. This
1202 		 *    thread is woken up by ->sk_state_changed().
1203 		 */
1204 
1205 		if (atomic_read(&session->terminate))
1206 			break;
1207 
1208 		if (ctrl_sk->sk_state != BT_CONNECTED ||
1209 		    intr_sk->sk_state != BT_CONNECTED)
1210 			break;
1211 
1212 		/* parse incoming intr-skbs */
1213 		while ((skb = skb_dequeue(&intr_sk->sk_receive_queue))) {
1214 			skb_orphan(skb);
1215 			if (!skb_linearize(skb))
1216 				hidp_recv_intr_frame(session, skb);
1217 			else
1218 				kfree_skb(skb);
1219 		}
1220 
1221 		/* send pending intr-skbs */
1222 		hidp_process_transmit(session, &session->intr_transmit,
1223 				      session->intr_sock);
1224 
1225 		/* parse incoming ctrl-skbs */
1226 		while ((skb = skb_dequeue(&ctrl_sk->sk_receive_queue))) {
1227 			skb_orphan(skb);
1228 			if (!skb_linearize(skb))
1229 				hidp_recv_ctrl_frame(session, skb);
1230 			else
1231 				kfree_skb(skb);
1232 		}
1233 
1234 		/* send pending ctrl-skbs */
1235 		hidp_process_transmit(session, &session->ctrl_transmit,
1236 				      session->ctrl_sock);
1237 
1238 		/*
1239 		 * wait_woken() performs the necessary memory barriers
1240 		 * for us; see the header comment for this primitive.
1241 		 */
1242 		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
1243 	}
1244 	remove_wait_queue(&hidp_session_wq, &wait);
1245 
1246 	atomic_inc(&session->terminate);
1247 }
1248 
1249 static int hidp_session_wake_function(wait_queue_entry_t *wait,
1250 				      unsigned int mode,
1251 				      int sync, void *key)
1252 {
1253 	wake_up_interruptible(&hidp_session_wq);
1254 	return false;
1255 }
1256 
1257 /*
1258  * HIDP session thread
1259  * This thread runs the I/O for a single HIDP session. Startup is synchronous
1260  * which allows us to take references to ourself here instead of doing that in
1261  * the caller.
1262  * When we are ready to run we notify the caller and call hidp_session_run().
1263  */
1264 static int hidp_session_thread(void *arg)
1265 {
1266 	struct hidp_session *session = arg;
1267 	DEFINE_WAIT_FUNC(ctrl_wait, hidp_session_wake_function);
1268 	DEFINE_WAIT_FUNC(intr_wait, hidp_session_wake_function);
1269 
1270 	BT_DBG("session %p", session);
1271 
1272 	/* initialize runtime environment */
1273 	hidp_session_get(session);
1274 	__module_get(THIS_MODULE);
1275 	set_user_nice(current, -15);
1276 	hidp_set_timer(session);
1277 
1278 	add_wait_queue(sk_sleep(session->ctrl_sock->sk), &ctrl_wait);
1279 	add_wait_queue(sk_sleep(session->intr_sock->sk), &intr_wait);
1280 	/* This memory barrier is paired with wq_has_sleeper(). See
1281 	 * sock_poll_wait() for more information why this is needed. */
1282 	smp_mb__before_atomic();
1283 
1284 	/* notify synchronous startup that we're ready */
1285 	atomic_inc(&session->state);
1286 	wake_up(&session->state_queue);
1287 
1288 	/* run session */
1289 	hidp_session_run(session);
1290 
1291 	/* cleanup runtime environment */
1292 	remove_wait_queue(sk_sleep(session->intr_sock->sk), &intr_wait);
1293 	remove_wait_queue(sk_sleep(session->ctrl_sock->sk), &ctrl_wait);
1294 	wake_up_interruptible(&session->report_queue);
1295 	hidp_del_timer(session);
1296 
1297 	/*
1298 	 * If we stopped ourself due to any internal signal, we should try to
1299 	 * unregister our own session here to avoid having it linger until the
1300 	 * parent l2cap_conn dies or user-space cleans it up.
1301 	 * This does not deadlock as we don't do any synchronous shutdown.
1302 	 * Instead, this call has the same semantics as if user-space tried to
1303 	 * delete the session.
1304 	 */
1305 	l2cap_unregister_user(session->conn, &session->user);
1306 	hidp_session_put(session);
1307 
1308 	module_put_and_kthread_exit(0);
1309 	return 0;
1310 }
1311 
1312 static int hidp_verify_sockets(struct socket *ctrl_sock,
1313 			       struct socket *intr_sock)
1314 {
1315 	struct l2cap_chan *ctrl_chan, *intr_chan;
1316 	struct bt_sock *ctrl, *intr;
1317 	struct hidp_session *session;
1318 
1319 	if (!l2cap_is_socket(ctrl_sock) || !l2cap_is_socket(intr_sock))
1320 		return -EINVAL;
1321 
1322 	ctrl_chan = l2cap_pi(ctrl_sock->sk)->chan;
1323 	intr_chan = l2cap_pi(intr_sock->sk)->chan;
1324 
1325 	if (bacmp(&ctrl_chan->src, &intr_chan->src) ||
1326 	    bacmp(&ctrl_chan->dst, &intr_chan->dst))
1327 		return -ENOTUNIQ;
1328 
1329 	ctrl = bt_sk(ctrl_sock->sk);
1330 	intr = bt_sk(intr_sock->sk);
1331 
1332 	if (ctrl->sk.sk_state != BT_CONNECTED ||
1333 	    intr->sk.sk_state != BT_CONNECTED)
1334 		return -EBADFD;
1335 
1336 	/* early session check, we check again during session registration */
1337 	session = hidp_session_find(&ctrl_chan->dst);
1338 	if (session) {
1339 		hidp_session_put(session);
1340 		return -EEXIST;
1341 	}
1342 
1343 	return 0;
1344 }
1345 
1346 int hidp_connection_add(const struct hidp_connadd_req *req,
1347 			struct socket *ctrl_sock,
1348 			struct socket *intr_sock)
1349 {
1350 	u32 valid_flags = BIT(HIDP_VIRTUAL_CABLE_UNPLUG) |
1351 			  BIT(HIDP_BOOT_PROTOCOL_MODE);
1352 	struct hidp_session *session;
1353 	struct l2cap_conn *conn;
1354 	struct l2cap_chan *chan;
1355 	int ret;
1356 
1357 	ret = hidp_verify_sockets(ctrl_sock, intr_sock);
1358 	if (ret)
1359 		return ret;
1360 
1361 	if (req->flags & ~valid_flags)
1362 		return -EINVAL;
1363 
1364 	chan = l2cap_pi(ctrl_sock->sk)->chan;
1365 	conn = NULL;
1366 	l2cap_chan_lock(chan);
1367 	if (chan->conn)
1368 		conn = l2cap_conn_get(chan->conn);
1369 	l2cap_chan_unlock(chan);
1370 
1371 	if (!conn)
1372 		return -EBADFD;
1373 
1374 	ret = hidp_session_new(&session, &chan->dst, ctrl_sock,
1375 			       intr_sock, req, conn);
1376 	if (ret)
1377 		goto out_conn;
1378 
1379 	ret = l2cap_register_user(conn, &session->user);
1380 	if (ret)
1381 		goto out_session;
1382 
1383 	ret = 0;
1384 
1385 out_session:
1386 	hidp_session_put(session);
1387 out_conn:
1388 	l2cap_conn_put(conn);
1389 	return ret;
1390 }
1391 
1392 int hidp_connection_del(struct hidp_conndel_req *req)
1393 {
1394 	u32 valid_flags = BIT(HIDP_VIRTUAL_CABLE_UNPLUG);
1395 	struct hidp_session *session;
1396 
1397 	if (req->flags & ~valid_flags)
1398 		return -EINVAL;
1399 
1400 	session = hidp_session_find(&req->bdaddr);
1401 	if (!session)
1402 		return -ENOENT;
1403 
1404 	if (req->flags & BIT(HIDP_VIRTUAL_CABLE_UNPLUG))
1405 		hidp_send_ctrl_message(session,
1406 				       HIDP_TRANS_HID_CONTROL |
1407 				         HIDP_CTRL_VIRTUAL_CABLE_UNPLUG,
1408 				       NULL, 0);
1409 	else
1410 		l2cap_unregister_user(session->conn, &session->user);
1411 
1412 	hidp_session_put(session);
1413 
1414 	return 0;
1415 }
1416 
1417 int hidp_get_connlist(struct hidp_connlist_req *req)
1418 {
1419 	struct hidp_session *session;
1420 	int err = 0, n = 0;
1421 
1422 	BT_DBG("");
1423 
1424 	down_read(&hidp_session_sem);
1425 
1426 	list_for_each_entry(session, &hidp_session_list, list) {
1427 		struct hidp_conninfo ci;
1428 
1429 		hidp_copy_session(session, &ci);
1430 
1431 		if (copy_to_user(req->ci, &ci, sizeof(ci))) {
1432 			err = -EFAULT;
1433 			break;
1434 		}
1435 
1436 		if (++n >= req->cnum)
1437 			break;
1438 
1439 		req->ci++;
1440 	}
1441 	req->cnum = n;
1442 
1443 	up_read(&hidp_session_sem);
1444 	return err;
1445 }
1446 
1447 int hidp_get_conninfo(struct hidp_conninfo *ci)
1448 {
1449 	struct hidp_session *session;
1450 
1451 	session = hidp_session_find(&ci->bdaddr);
1452 	if (session) {
1453 		hidp_copy_session(session, ci);
1454 		hidp_session_put(session);
1455 	}
1456 
1457 	return session ? 0 : -ENOENT;
1458 }
1459 
1460 static int __init hidp_init(void)
1461 {
1462 	BT_INFO("HIDP (Human Interface Emulation) ver %s", VERSION);
1463 
1464 	return hidp_init_sockets();
1465 }
1466 
1467 static void __exit hidp_exit(void)
1468 {
1469 	hidp_cleanup_sockets();
1470 }
1471 
1472 module_init(hidp_init);
1473 module_exit(hidp_exit);
1474 
1475 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
1476 MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>");
1477 MODULE_DESCRIPTION("Bluetooth HIDP ver " VERSION);
1478 MODULE_VERSION(VERSION);
1479 MODULE_LICENSE("GPL");
1480 MODULE_ALIAS("bt-proto-6");
1481