xref: /linux/net/nfc/netlink.c (revision 800c5eb7b5eba6cb2a32738d763fd59f0fbcdde4)
1 /*
2  * Copyright (C) 2011 Instituto Nokia de Tecnologia
3  *
4  * Authors:
5  *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
6  *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the
20  * Free Software Foundation, Inc.,
21  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22  */
23 
24 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
25 
26 #include <net/genetlink.h>
27 #include <linux/nfc.h>
28 #include <linux/slab.h>
29 
30 #include "nfc.h"
31 
32 static struct genl_multicast_group nfc_genl_event_mcgrp = {
33 	.name = NFC_GENL_MCAST_EVENT_NAME,
34 };
35 
36 struct genl_family nfc_genl_family = {
37 	.id = GENL_ID_GENERATE,
38 	.hdrsize = 0,
39 	.name = NFC_GENL_NAME,
40 	.version = NFC_GENL_VERSION,
41 	.maxattr = NFC_ATTR_MAX,
42 };
43 
44 static const struct nla_policy nfc_genl_policy[NFC_ATTR_MAX + 1] = {
45 	[NFC_ATTR_DEVICE_INDEX] = { .type = NLA_U32 },
46 	[NFC_ATTR_DEVICE_NAME] = { .type = NLA_STRING,
47 				.len = NFC_DEVICE_NAME_MAXSIZE },
48 	[NFC_ATTR_PROTOCOLS] = { .type = NLA_U32 },
49 	[NFC_ATTR_COMM_MODE] = { .type = NLA_U8 },
50 	[NFC_ATTR_RF_MODE] = { .type = NLA_U8 },
51 };
52 
53 static int nfc_genl_send_target(struct sk_buff *msg, struct nfc_target *target,
54 					struct netlink_callback *cb, int flags)
55 {
56 	void *hdr;
57 
58 	hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
59 				&nfc_genl_family, flags, NFC_CMD_GET_TARGET);
60 	if (!hdr)
61 		return -EMSGSIZE;
62 
63 	genl_dump_check_consistent(cb, hdr, &nfc_genl_family);
64 
65 	NLA_PUT_U32(msg, NFC_ATTR_TARGET_INDEX, target->idx);
66 	NLA_PUT_U32(msg, NFC_ATTR_PROTOCOLS,
67 				target->supported_protocols);
68 	NLA_PUT_U16(msg, NFC_ATTR_TARGET_SENS_RES, target->sens_res);
69 	NLA_PUT_U8(msg, NFC_ATTR_TARGET_SEL_RES, target->sel_res);
70 	if (target->nfcid1_len > 0)
71 		NLA_PUT(msg, NFC_ATTR_TARGET_NFCID1, target->nfcid1_len,
72 				target->nfcid1);
73 	if (target->sensb_res_len > 0)
74 		NLA_PUT(msg, NFC_ATTR_TARGET_SENSB_RES, target->sensb_res_len,
75 				target->sensb_res);
76 	if (target->sensf_res_len > 0)
77 		NLA_PUT(msg, NFC_ATTR_TARGET_SENSF_RES, target->sensf_res_len,
78 				target->sensf_res);
79 
80 	return genlmsg_end(msg, hdr);
81 
82 nla_put_failure:
83 	genlmsg_cancel(msg, hdr);
84 	return -EMSGSIZE;
85 }
86 
87 static struct nfc_dev *__get_device_from_cb(struct netlink_callback *cb)
88 {
89 	struct nfc_dev *dev;
90 	int rc;
91 	u32 idx;
92 
93 	rc = nlmsg_parse(cb->nlh, GENL_HDRLEN + nfc_genl_family.hdrsize,
94 						nfc_genl_family.attrbuf,
95 						nfc_genl_family.maxattr,
96 						nfc_genl_policy);
97 	if (rc < 0)
98 		return ERR_PTR(rc);
99 
100 	if (!nfc_genl_family.attrbuf[NFC_ATTR_DEVICE_INDEX])
101 		return ERR_PTR(-EINVAL);
102 
103 	idx = nla_get_u32(nfc_genl_family.attrbuf[NFC_ATTR_DEVICE_INDEX]);
104 
105 	dev = nfc_get_device(idx);
106 	if (!dev)
107 		return ERR_PTR(-ENODEV);
108 
109 	return dev;
110 }
111 
112 static int nfc_genl_dump_targets(struct sk_buff *skb,
113 				struct netlink_callback *cb)
114 {
115 	int i = cb->args[0];
116 	struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
117 	int rc;
118 
119 	if (!dev) {
120 		dev = __get_device_from_cb(cb);
121 		if (IS_ERR(dev))
122 			return PTR_ERR(dev);
123 
124 		cb->args[1] = (long) dev;
125 	}
126 
127 	spin_lock_bh(&dev->targets_lock);
128 
129 	cb->seq = dev->targets_generation;
130 
131 	while (i < dev->n_targets) {
132 		rc = nfc_genl_send_target(skb, &dev->targets[i], cb,
133 								NLM_F_MULTI);
134 		if (rc < 0)
135 			break;
136 
137 		i++;
138 	}
139 
140 	spin_unlock_bh(&dev->targets_lock);
141 
142 	cb->args[0] = i;
143 
144 	return skb->len;
145 }
146 
147 static int nfc_genl_dump_targets_done(struct netlink_callback *cb)
148 {
149 	struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
150 
151 	if (dev)
152 		nfc_put_device(dev);
153 
154 	return 0;
155 }
156 
157 int nfc_genl_targets_found(struct nfc_dev *dev)
158 {
159 	struct sk_buff *msg;
160 	void *hdr;
161 
162 	dev->genl_data.poll_req_pid = 0;
163 
164 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
165 	if (!msg)
166 		return -ENOMEM;
167 
168 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
169 				NFC_EVENT_TARGETS_FOUND);
170 	if (!hdr)
171 		goto free_msg;
172 
173 	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
174 
175 	genlmsg_end(msg, hdr);
176 
177 	return genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);
178 
179 nla_put_failure:
180 	genlmsg_cancel(msg, hdr);
181 free_msg:
182 	nlmsg_free(msg);
183 	return -EMSGSIZE;
184 }
185 
186 int nfc_genl_device_added(struct nfc_dev *dev)
187 {
188 	struct sk_buff *msg;
189 	void *hdr;
190 
191 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
192 	if (!msg)
193 		return -ENOMEM;
194 
195 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
196 				NFC_EVENT_DEVICE_ADDED);
197 	if (!hdr)
198 		goto free_msg;
199 
200 	NLA_PUT_STRING(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev));
201 	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
202 	NLA_PUT_U32(msg, NFC_ATTR_PROTOCOLS, dev->supported_protocols);
203 
204 	genlmsg_end(msg, hdr);
205 
206 	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);
207 
208 	return 0;
209 
210 nla_put_failure:
211 	genlmsg_cancel(msg, hdr);
212 free_msg:
213 	nlmsg_free(msg);
214 	return -EMSGSIZE;
215 }
216 
217 int nfc_genl_device_removed(struct nfc_dev *dev)
218 {
219 	struct sk_buff *msg;
220 	void *hdr;
221 
222 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
223 	if (!msg)
224 		return -ENOMEM;
225 
226 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
227 				NFC_EVENT_DEVICE_REMOVED);
228 	if (!hdr)
229 		goto free_msg;
230 
231 	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
232 
233 	genlmsg_end(msg, hdr);
234 
235 	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);
236 
237 	return 0;
238 
239 nla_put_failure:
240 	genlmsg_cancel(msg, hdr);
241 free_msg:
242 	nlmsg_free(msg);
243 	return -EMSGSIZE;
244 }
245 
246 static int nfc_genl_send_device(struct sk_buff *msg, struct nfc_dev *dev,
247 						u32 pid, u32 seq,
248 						struct netlink_callback *cb,
249 						int flags)
250 {
251 	void *hdr;
252 
253 	hdr = genlmsg_put(msg, pid, seq, &nfc_genl_family, flags,
254 							NFC_CMD_GET_DEVICE);
255 	if (!hdr)
256 		return -EMSGSIZE;
257 
258 	if (cb)
259 		genl_dump_check_consistent(cb, hdr, &nfc_genl_family);
260 
261 	NLA_PUT_STRING(msg, NFC_ATTR_DEVICE_NAME, nfc_device_name(dev));
262 	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
263 	NLA_PUT_U32(msg, NFC_ATTR_PROTOCOLS, dev->supported_protocols);
264 
265 	return genlmsg_end(msg, hdr);
266 
267 nla_put_failure:
268 	genlmsg_cancel(msg, hdr);
269 	return -EMSGSIZE;
270 }
271 
272 static int nfc_genl_dump_devices(struct sk_buff *skb,
273 				struct netlink_callback *cb)
274 {
275 	struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];
276 	struct nfc_dev *dev = (struct nfc_dev *) cb->args[1];
277 	bool first_call = false;
278 
279 	if (!iter) {
280 		first_call = true;
281 		iter = kmalloc(sizeof(struct class_dev_iter), GFP_KERNEL);
282 		if (!iter)
283 			return -ENOMEM;
284 		cb->args[0] = (long) iter;
285 	}
286 
287 	mutex_lock(&nfc_devlist_mutex);
288 
289 	cb->seq = nfc_devlist_generation;
290 
291 	if (first_call) {
292 		nfc_device_iter_init(iter);
293 		dev = nfc_device_iter_next(iter);
294 	}
295 
296 	while (dev) {
297 		int rc;
298 
299 		rc = nfc_genl_send_device(skb, dev, NETLINK_CB(cb->skb).pid,
300 							cb->nlh->nlmsg_seq,
301 							cb, NLM_F_MULTI);
302 		if (rc < 0)
303 			break;
304 
305 		dev = nfc_device_iter_next(iter);
306 	}
307 
308 	mutex_unlock(&nfc_devlist_mutex);
309 
310 	cb->args[1] = (long) dev;
311 
312 	return skb->len;
313 }
314 
315 static int nfc_genl_dump_devices_done(struct netlink_callback *cb)
316 {
317 	struct class_dev_iter *iter = (struct class_dev_iter *) cb->args[0];
318 
319 	nfc_device_iter_exit(iter);
320 	kfree(iter);
321 
322 	return 0;
323 }
324 
325 int nfc_genl_dep_link_up_event(struct nfc_dev *dev, u32 target_idx,
326 						u8 comm_mode, u8 rf_mode)
327 {
328 	struct sk_buff *msg;
329 	void *hdr;
330 
331 	pr_debug("DEP link is up\n");
332 
333 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
334 	if (!msg)
335 		return -ENOMEM;
336 
337 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
338 				NFC_CMD_DEP_LINK_UP);
339 	if (!hdr)
340 		goto free_msg;
341 
342 	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
343 	if (rf_mode == NFC_RF_INITIATOR)
344 		NLA_PUT_U32(msg, NFC_ATTR_TARGET_INDEX, target_idx);
345 	NLA_PUT_U8(msg, NFC_ATTR_COMM_MODE, comm_mode);
346 	NLA_PUT_U8(msg, NFC_ATTR_RF_MODE, rf_mode);
347 
348 	genlmsg_end(msg, hdr);
349 
350 	dev->dep_link_up = true;
351 
352 	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);
353 
354 	return 0;
355 
356 nla_put_failure:
357 	genlmsg_cancel(msg, hdr);
358 free_msg:
359 	nlmsg_free(msg);
360 	return -EMSGSIZE;
361 }
362 
363 int nfc_genl_dep_link_down_event(struct nfc_dev *dev)
364 {
365 	struct sk_buff *msg;
366 	void *hdr;
367 
368 	pr_debug("DEP link is down\n");
369 
370 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
371 	if (!msg)
372 		return -ENOMEM;
373 
374 	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
375 				NFC_CMD_DEP_LINK_DOWN);
376 	if (!hdr)
377 		goto free_msg;
378 
379 	NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
380 
381 	genlmsg_end(msg, hdr);
382 
383 	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);
384 
385 	return 0;
386 
387 nla_put_failure:
388 	genlmsg_cancel(msg, hdr);
389 free_msg:
390 	nlmsg_free(msg);
391 	return -EMSGSIZE;
392 }
393 
394 static int nfc_genl_get_device(struct sk_buff *skb, struct genl_info *info)
395 {
396 	struct sk_buff *msg;
397 	struct nfc_dev *dev;
398 	u32 idx;
399 	int rc = -ENOBUFS;
400 
401 	if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
402 		return -EINVAL;
403 
404 	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
405 
406 	dev = nfc_get_device(idx);
407 	if (!dev)
408 		return -ENODEV;
409 
410 	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
411 	if (!msg) {
412 		rc = -ENOMEM;
413 		goto out_putdev;
414 	}
415 
416 	rc = nfc_genl_send_device(msg, dev, info->snd_pid, info->snd_seq,
417 								NULL, 0);
418 	if (rc < 0)
419 		goto out_free;
420 
421 	nfc_put_device(dev);
422 
423 	return genlmsg_reply(msg, info);
424 
425 out_free:
426 	nlmsg_free(msg);
427 out_putdev:
428 	nfc_put_device(dev);
429 	return rc;
430 }
431 
432 static int nfc_genl_dev_up(struct sk_buff *skb, struct genl_info *info)
433 {
434 	struct nfc_dev *dev;
435 	int rc;
436 	u32 idx;
437 
438 	if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
439 		return -EINVAL;
440 
441 	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
442 
443 	dev = nfc_get_device(idx);
444 	if (!dev)
445 		return -ENODEV;
446 
447 	rc = nfc_dev_up(dev);
448 
449 	nfc_put_device(dev);
450 	return rc;
451 }
452 
453 static int nfc_genl_dev_down(struct sk_buff *skb, struct genl_info *info)
454 {
455 	struct nfc_dev *dev;
456 	int rc;
457 	u32 idx;
458 
459 	if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
460 		return -EINVAL;
461 
462 	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
463 
464 	dev = nfc_get_device(idx);
465 	if (!dev)
466 		return -ENODEV;
467 
468 	rc = nfc_dev_down(dev);
469 
470 	nfc_put_device(dev);
471 	return rc;
472 }
473 
474 static int nfc_genl_start_poll(struct sk_buff *skb, struct genl_info *info)
475 {
476 	struct nfc_dev *dev;
477 	int rc;
478 	u32 idx;
479 	u32 protocols;
480 
481 	pr_debug("Poll start\n");
482 
483 	if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
484 		!info->attrs[NFC_ATTR_PROTOCOLS])
485 		return -EINVAL;
486 
487 	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
488 	protocols = nla_get_u32(info->attrs[NFC_ATTR_PROTOCOLS]);
489 
490 	dev = nfc_get_device(idx);
491 	if (!dev)
492 		return -ENODEV;
493 
494 	mutex_lock(&dev->genl_data.genl_data_mutex);
495 
496 	rc = nfc_start_poll(dev, protocols);
497 	if (!rc)
498 		dev->genl_data.poll_req_pid = info->snd_pid;
499 
500 	mutex_unlock(&dev->genl_data.genl_data_mutex);
501 
502 	nfc_put_device(dev);
503 	return rc;
504 }
505 
506 static int nfc_genl_stop_poll(struct sk_buff *skb, struct genl_info *info)
507 {
508 	struct nfc_dev *dev;
509 	int rc;
510 	u32 idx;
511 
512 	if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
513 		return -EINVAL;
514 
515 	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
516 
517 	dev = nfc_get_device(idx);
518 	if (!dev)
519 		return -ENODEV;
520 
521 	mutex_lock(&dev->genl_data.genl_data_mutex);
522 
523 	if (dev->genl_data.poll_req_pid != info->snd_pid) {
524 		rc = -EBUSY;
525 		goto out;
526 	}
527 
528 	rc = nfc_stop_poll(dev);
529 	dev->genl_data.poll_req_pid = 0;
530 
531 out:
532 	mutex_unlock(&dev->genl_data.genl_data_mutex);
533 	nfc_put_device(dev);
534 	return rc;
535 }
536 
537 static int nfc_genl_dep_link_up(struct sk_buff *skb, struct genl_info *info)
538 {
539 	struct nfc_dev *dev;
540 	int rc, tgt_idx;
541 	u32 idx;
542 	u8 comm, rf;
543 
544 	pr_debug("DEP link up\n");
545 
546 	if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
547 			!info->attrs[NFC_ATTR_COMM_MODE] ||
548 			!info->attrs[NFC_ATTR_RF_MODE])
549 		return -EINVAL;
550 
551 	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
552 	if (!info->attrs[NFC_ATTR_TARGET_INDEX])
553 		tgt_idx = NFC_TARGET_IDX_ANY;
554 	else
555 		tgt_idx = nla_get_u32(info->attrs[NFC_ATTR_TARGET_INDEX]);
556 
557 	comm = nla_get_u8(info->attrs[NFC_ATTR_COMM_MODE]);
558 	rf = nla_get_u8(info->attrs[NFC_ATTR_RF_MODE]);
559 
560 	if (comm != NFC_COMM_ACTIVE && comm != NFC_COMM_PASSIVE)
561 		return -EINVAL;
562 
563 	if (rf != NFC_RF_INITIATOR && comm != NFC_RF_TARGET)
564 		return -EINVAL;
565 
566 	dev = nfc_get_device(idx);
567 	if (!dev)
568 		return -ENODEV;
569 
570 	rc = nfc_dep_link_up(dev, tgt_idx, comm, rf);
571 
572 	nfc_put_device(dev);
573 
574 	return rc;
575 }
576 
577 static int nfc_genl_dep_link_down(struct sk_buff *skb, struct genl_info *info)
578 {
579 	struct nfc_dev *dev;
580 	int rc;
581 	u32 idx;
582 
583 	if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
584 		return -EINVAL;
585 
586 	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
587 
588 	dev = nfc_get_device(idx);
589 	if (!dev)
590 		return -ENODEV;
591 
592 	rc = nfc_dep_link_down(dev);
593 
594 	nfc_put_device(dev);
595 	return rc;
596 }
597 
598 static struct genl_ops nfc_genl_ops[] = {
599 	{
600 		.cmd = NFC_CMD_GET_DEVICE,
601 		.doit = nfc_genl_get_device,
602 		.dumpit = nfc_genl_dump_devices,
603 		.done = nfc_genl_dump_devices_done,
604 		.policy = nfc_genl_policy,
605 	},
606 	{
607 		.cmd = NFC_CMD_DEV_UP,
608 		.doit = nfc_genl_dev_up,
609 		.policy = nfc_genl_policy,
610 	},
611 	{
612 		.cmd = NFC_CMD_DEV_DOWN,
613 		.doit = nfc_genl_dev_down,
614 		.policy = nfc_genl_policy,
615 	},
616 	{
617 		.cmd = NFC_CMD_START_POLL,
618 		.doit = nfc_genl_start_poll,
619 		.policy = nfc_genl_policy,
620 	},
621 	{
622 		.cmd = NFC_CMD_STOP_POLL,
623 		.doit = nfc_genl_stop_poll,
624 		.policy = nfc_genl_policy,
625 	},
626 	{
627 		.cmd = NFC_CMD_DEP_LINK_UP,
628 		.doit = nfc_genl_dep_link_up,
629 		.policy = nfc_genl_policy,
630 	},
631 	{
632 		.cmd = NFC_CMD_DEP_LINK_DOWN,
633 		.doit = nfc_genl_dep_link_down,
634 		.policy = nfc_genl_policy,
635 	},
636 	{
637 		.cmd = NFC_CMD_GET_TARGET,
638 		.dumpit = nfc_genl_dump_targets,
639 		.done = nfc_genl_dump_targets_done,
640 		.policy = nfc_genl_policy,
641 	},
642 };
643 
644 static int nfc_genl_rcv_nl_event(struct notifier_block *this,
645 						unsigned long event, void *ptr)
646 {
647 	struct netlink_notify *n = ptr;
648 	struct class_dev_iter iter;
649 	struct nfc_dev *dev;
650 
651 	if (event != NETLINK_URELEASE || n->protocol != NETLINK_GENERIC)
652 		goto out;
653 
654 	pr_debug("NETLINK_URELEASE event from id %d\n", n->pid);
655 
656 	nfc_device_iter_init(&iter);
657 	dev = nfc_device_iter_next(&iter);
658 
659 	while (dev) {
660 		if (dev->genl_data.poll_req_pid == n->pid) {
661 			nfc_stop_poll(dev);
662 			dev->genl_data.poll_req_pid = 0;
663 		}
664 		dev = nfc_device_iter_next(&iter);
665 	}
666 
667 	nfc_device_iter_exit(&iter);
668 
669 out:
670 	return NOTIFY_DONE;
671 }
672 
673 void nfc_genl_data_init(struct nfc_genl_data *genl_data)
674 {
675 	genl_data->poll_req_pid = 0;
676 	mutex_init(&genl_data->genl_data_mutex);
677 }
678 
679 void nfc_genl_data_exit(struct nfc_genl_data *genl_data)
680 {
681 	mutex_destroy(&genl_data->genl_data_mutex);
682 }
683 
684 static struct notifier_block nl_notifier = {
685 	.notifier_call  = nfc_genl_rcv_nl_event,
686 };
687 
688 /**
689  * nfc_genl_init() - Initialize netlink interface
690  *
691  * This initialization function registers the nfc netlink family.
692  */
693 int __init nfc_genl_init(void)
694 {
695 	int rc;
696 
697 	rc = genl_register_family_with_ops(&nfc_genl_family, nfc_genl_ops,
698 					ARRAY_SIZE(nfc_genl_ops));
699 	if (rc)
700 		return rc;
701 
702 	rc = genl_register_mc_group(&nfc_genl_family, &nfc_genl_event_mcgrp);
703 
704 	netlink_register_notifier(&nl_notifier);
705 
706 	return rc;
707 }
708 
709 /**
710  * nfc_genl_exit() - Deinitialize netlink interface
711  *
712  * This exit function unregisters the nfc netlink family.
713  */
714 void nfc_genl_exit(void)
715 {
716 	netlink_unregister_notifier(&nl_notifier);
717 	genl_unregister_family(&nfc_genl_family);
718 }
719