xref: /linux/net/nfc/llcp_core.c (revision f3539c12d8196ce0a1993364d30b3a18908470d1)
1 /*
2  * Copyright (C) 2011  Intel Corporation. All rights reserved.
3  * Copyright (C) 2014 Marvell International Ltd.
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
20 
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/list.h>
24 #include <linux/nfc.h>
25 
26 #include "nfc.h"
27 #include "llcp.h"
28 
29 static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
30 
31 static LIST_HEAD(llcp_devices);
32 
33 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb);
34 
35 void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)
36 {
37 	write_lock(&l->lock);
38 	sk_add_node(sk, &l->head);
39 	write_unlock(&l->lock);
40 }
41 
42 void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
43 {
44 	write_lock(&l->lock);
45 	sk_del_node_init(sk);
46 	write_unlock(&l->lock);
47 }
48 
49 void nfc_llcp_socket_remote_param_init(struct nfc_llcp_sock *sock)
50 {
51 	sock->remote_rw = LLCP_DEFAULT_RW;
52 	sock->remote_miu = LLCP_MAX_MIU + 1;
53 }
54 
55 static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock)
56 {
57 	struct nfc_llcp_local *local = sock->local;
58 	struct sk_buff *s, *tmp;
59 
60 	pr_debug("%p\n", &sock->sk);
61 
62 	skb_queue_purge(&sock->tx_queue);
63 	skb_queue_purge(&sock->tx_pending_queue);
64 
65 	if (local == NULL)
66 		return;
67 
68 	/* Search for local pending SKBs that are related to this socket */
69 	skb_queue_walk_safe(&local->tx_queue, s, tmp) {
70 		if (s->sk != &sock->sk)
71 			continue;
72 
73 		skb_unlink(s, &local->tx_queue);
74 		kfree_skb(s);
75 	}
76 }
77 
78 static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device,
79 				    int err)
80 {
81 	struct sock *sk;
82 	struct hlist_node *tmp;
83 	struct nfc_llcp_sock *llcp_sock;
84 
85 	skb_queue_purge(&local->tx_queue);
86 
87 	write_lock(&local->sockets.lock);
88 
89 	sk_for_each_safe(sk, tmp, &local->sockets.head) {
90 		llcp_sock = nfc_llcp_sock(sk);
91 
92 		bh_lock_sock(sk);
93 
94 		nfc_llcp_socket_purge(llcp_sock);
95 
96 		if (sk->sk_state == LLCP_CONNECTED)
97 			nfc_put_device(llcp_sock->dev);
98 
99 		if (sk->sk_state == LLCP_LISTEN) {
100 			struct nfc_llcp_sock *lsk, *n;
101 			struct sock *accept_sk;
102 
103 			list_for_each_entry_safe(lsk, n,
104 						 &llcp_sock->accept_queue,
105 						 accept_queue) {
106 				accept_sk = &lsk->sk;
107 				bh_lock_sock(accept_sk);
108 
109 				nfc_llcp_accept_unlink(accept_sk);
110 
111 				if (err)
112 					accept_sk->sk_err = err;
113 				accept_sk->sk_state = LLCP_CLOSED;
114 				accept_sk->sk_state_change(sk);
115 
116 				bh_unlock_sock(accept_sk);
117 			}
118 		}
119 
120 		if (err)
121 			sk->sk_err = err;
122 		sk->sk_state = LLCP_CLOSED;
123 		sk->sk_state_change(sk);
124 
125 		bh_unlock_sock(sk);
126 
127 		sk_del_node_init(sk);
128 	}
129 
130 	write_unlock(&local->sockets.lock);
131 
132 	/* If we still have a device, we keep the RAW sockets alive */
133 	if (device == true)
134 		return;
135 
136 	write_lock(&local->raw_sockets.lock);
137 
138 	sk_for_each_safe(sk, tmp, &local->raw_sockets.head) {
139 		llcp_sock = nfc_llcp_sock(sk);
140 
141 		bh_lock_sock(sk);
142 
143 		nfc_llcp_socket_purge(llcp_sock);
144 
145 		if (err)
146 			sk->sk_err = err;
147 		sk->sk_state = LLCP_CLOSED;
148 		sk->sk_state_change(sk);
149 
150 		bh_unlock_sock(sk);
151 
152 		sk_del_node_init(sk);
153 	}
154 
155 	write_unlock(&local->raw_sockets.lock);
156 }
157 
158 struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
159 {
160 	kref_get(&local->ref);
161 
162 	return local;
163 }
164 
165 static void local_cleanup(struct nfc_llcp_local *local)
166 {
167 	nfc_llcp_socket_release(local, false, ENXIO);
168 	del_timer_sync(&local->link_timer);
169 	skb_queue_purge(&local->tx_queue);
170 	cancel_work_sync(&local->tx_work);
171 	cancel_work_sync(&local->rx_work);
172 	cancel_work_sync(&local->timeout_work);
173 	kfree_skb(local->rx_pending);
174 	del_timer_sync(&local->sdreq_timer);
175 	cancel_work_sync(&local->sdreq_timeout_work);
176 	nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);
177 }
178 
179 static void local_release(struct kref *ref)
180 {
181 	struct nfc_llcp_local *local;
182 
183 	local = container_of(ref, struct nfc_llcp_local, ref);
184 
185 	list_del(&local->list);
186 	local_cleanup(local);
187 	kfree(local);
188 }
189 
190 int nfc_llcp_local_put(struct nfc_llcp_local *local)
191 {
192 	if (local == NULL)
193 		return 0;
194 
195 	return kref_put(&local->ref, local_release);
196 }
197 
198 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
199 					       u8 ssap, u8 dsap)
200 {
201 	struct sock *sk;
202 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
203 
204 	pr_debug("ssap dsap %d %d\n", ssap, dsap);
205 
206 	if (ssap == 0 && dsap == 0)
207 		return NULL;
208 
209 	read_lock(&local->sockets.lock);
210 
211 	llcp_sock = NULL;
212 
213 	sk_for_each(sk, &local->sockets.head) {
214 		tmp_sock = nfc_llcp_sock(sk);
215 
216 		if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
217 			llcp_sock = tmp_sock;
218 			break;
219 		}
220 	}
221 
222 	read_unlock(&local->sockets.lock);
223 
224 	if (llcp_sock == NULL)
225 		return NULL;
226 
227 	sock_hold(&llcp_sock->sk);
228 
229 	return llcp_sock;
230 }
231 
232 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
233 {
234 	sock_put(&sock->sk);
235 }
236 
237 static void nfc_llcp_timeout_work(struct work_struct *work)
238 {
239 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
240 						    timeout_work);
241 
242 	nfc_dep_link_down(local->dev);
243 }
244 
245 static void nfc_llcp_symm_timer(unsigned long data)
246 {
247 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
248 
249 	pr_err("SYMM timeout\n");
250 
251 	schedule_work(&local->timeout_work);
252 }
253 
254 static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
255 {
256 	unsigned long time;
257 	HLIST_HEAD(nl_sdres_list);
258 	struct hlist_node *n;
259 	struct nfc_llcp_sdp_tlv *sdp;
260 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
261 						    sdreq_timeout_work);
262 
263 	mutex_lock(&local->sdreq_lock);
264 
265 	time = jiffies - msecs_to_jiffies(3 * local->remote_lto);
266 
267 	hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) {
268 		if (time_after(sdp->time, time))
269 			continue;
270 
271 		sdp->sap = LLCP_SDP_UNBOUND;
272 
273 		hlist_del(&sdp->node);
274 
275 		hlist_add_head(&sdp->node, &nl_sdres_list);
276 	}
277 
278 	if (!hlist_empty(&local->pending_sdreqs))
279 		mod_timer(&local->sdreq_timer,
280 			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
281 
282 	mutex_unlock(&local->sdreq_lock);
283 
284 	if (!hlist_empty(&nl_sdres_list))
285 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
286 }
287 
288 static void nfc_llcp_sdreq_timer(unsigned long data)
289 {
290 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
291 
292 	schedule_work(&local->sdreq_timeout_work);
293 }
294 
295 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
296 {
297 	struct nfc_llcp_local *local;
298 
299 	list_for_each_entry(local, &llcp_devices, list)
300 		if (local->dev == dev)
301 			return local;
302 
303 	pr_debug("No device found\n");
304 
305 	return NULL;
306 }
307 
308 static char *wks[] = {
309 	NULL,
310 	NULL, /* SDP */
311 	"urn:nfc:sn:ip",
312 	"urn:nfc:sn:obex",
313 	"urn:nfc:sn:snep",
314 };
315 
316 static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
317 {
318 	int sap, num_wks;
319 
320 	pr_debug("%s\n", service_name);
321 
322 	if (service_name == NULL)
323 		return -EINVAL;
324 
325 	num_wks = ARRAY_SIZE(wks);
326 
327 	for (sap = 0; sap < num_wks; sap++) {
328 		if (wks[sap] == NULL)
329 			continue;
330 
331 		if (strncmp(wks[sap], service_name, service_name_len) == 0)
332 			return sap;
333 	}
334 
335 	return -EINVAL;
336 }
337 
338 static
339 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
340 					    u8 *sn, size_t sn_len)
341 {
342 	struct sock *sk;
343 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
344 
345 	pr_debug("sn %zd %p\n", sn_len, sn);
346 
347 	if (sn == NULL || sn_len == 0)
348 		return NULL;
349 
350 	read_lock(&local->sockets.lock);
351 
352 	llcp_sock = NULL;
353 
354 	sk_for_each(sk, &local->sockets.head) {
355 		tmp_sock = nfc_llcp_sock(sk);
356 
357 		pr_debug("llcp sock %p\n", tmp_sock);
358 
359 		if (tmp_sock->sk.sk_type == SOCK_STREAM &&
360 		    tmp_sock->sk.sk_state != LLCP_LISTEN)
361 			continue;
362 
363 		if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
364 		    tmp_sock->sk.sk_state != LLCP_BOUND)
365 			continue;
366 
367 		if (tmp_sock->service_name == NULL ||
368 		    tmp_sock->service_name_len == 0)
369 			continue;
370 
371 		if (tmp_sock->service_name_len != sn_len)
372 			continue;
373 
374 		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
375 			llcp_sock = tmp_sock;
376 			break;
377 		}
378 	}
379 
380 	read_unlock(&local->sockets.lock);
381 
382 	pr_debug("Found llcp sock %p\n", llcp_sock);
383 
384 	return llcp_sock;
385 }
386 
387 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
388 			 struct nfc_llcp_sock *sock)
389 {
390 	mutex_lock(&local->sdp_lock);
391 
392 	if (sock->service_name != NULL && sock->service_name_len > 0) {
393 		int ssap = nfc_llcp_wks_sap(sock->service_name,
394 					    sock->service_name_len);
395 
396 		if (ssap > 0) {
397 			pr_debug("WKS %d\n", ssap);
398 
399 			/* This is a WKS, let's check if it's free */
400 			if (local->local_wks & BIT(ssap)) {
401 				mutex_unlock(&local->sdp_lock);
402 
403 				return LLCP_SAP_MAX;
404 			}
405 
406 			set_bit(ssap, &local->local_wks);
407 			mutex_unlock(&local->sdp_lock);
408 
409 			return ssap;
410 		}
411 
412 		/*
413 		 * Check if there already is a non WKS socket bound
414 		 * to this service name.
415 		 */
416 		if (nfc_llcp_sock_from_sn(local, sock->service_name,
417 					  sock->service_name_len) != NULL) {
418 			mutex_unlock(&local->sdp_lock);
419 
420 			return LLCP_SAP_MAX;
421 		}
422 
423 		mutex_unlock(&local->sdp_lock);
424 
425 		return LLCP_SDP_UNBOUND;
426 
427 	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
428 		if (!test_bit(sock->ssap, &local->local_wks)) {
429 			set_bit(sock->ssap, &local->local_wks);
430 			mutex_unlock(&local->sdp_lock);
431 
432 			return sock->ssap;
433 		}
434 	}
435 
436 	mutex_unlock(&local->sdp_lock);
437 
438 	return LLCP_SAP_MAX;
439 }
440 
441 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
442 {
443 	u8 local_ssap;
444 
445 	mutex_lock(&local->sdp_lock);
446 
447 	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
448 	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
449 		mutex_unlock(&local->sdp_lock);
450 		return LLCP_SAP_MAX;
451 	}
452 
453 	set_bit(local_ssap, &local->local_sap);
454 
455 	mutex_unlock(&local->sdp_lock);
456 
457 	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
458 }
459 
460 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
461 {
462 	u8 local_ssap;
463 	unsigned long *sdp;
464 
465 	if (ssap < LLCP_WKS_NUM_SAP) {
466 		local_ssap = ssap;
467 		sdp = &local->local_wks;
468 	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
469 		atomic_t *client_cnt;
470 
471 		local_ssap = ssap - LLCP_WKS_NUM_SAP;
472 		sdp = &local->local_sdp;
473 		client_cnt = &local->local_sdp_cnt[local_ssap];
474 
475 		pr_debug("%d clients\n", atomic_read(client_cnt));
476 
477 		mutex_lock(&local->sdp_lock);
478 
479 		if (atomic_dec_and_test(client_cnt)) {
480 			struct nfc_llcp_sock *l_sock;
481 
482 			pr_debug("No more clients for SAP %d\n", ssap);
483 
484 			clear_bit(local_ssap, sdp);
485 
486 			/* Find the listening sock and set it back to UNBOUND */
487 			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
488 			if (l_sock) {
489 				l_sock->ssap = LLCP_SDP_UNBOUND;
490 				nfc_llcp_sock_put(l_sock);
491 			}
492 		}
493 
494 		mutex_unlock(&local->sdp_lock);
495 
496 		return;
497 	} else if (ssap < LLCP_MAX_SAP) {
498 		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
499 		sdp = &local->local_sap;
500 	} else {
501 		return;
502 	}
503 
504 	mutex_lock(&local->sdp_lock);
505 
506 	clear_bit(local_ssap, sdp);
507 
508 	mutex_unlock(&local->sdp_lock);
509 }
510 
511 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
512 {
513 	u8 ssap;
514 
515 	mutex_lock(&local->sdp_lock);
516 
517 	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
518 	if (ssap == LLCP_SDP_NUM_SAP) {
519 		mutex_unlock(&local->sdp_lock);
520 
521 		return LLCP_SAP_MAX;
522 	}
523 
524 	pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
525 
526 	set_bit(ssap, &local->local_sdp);
527 
528 	mutex_unlock(&local->sdp_lock);
529 
530 	return LLCP_WKS_NUM_SAP + ssap;
531 }
532 
533 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
534 {
535 	u8 *gb_cur, *version_tlv, version, version_length;
536 	u8 *lto_tlv, lto_length;
537 	u8 *wks_tlv, wks_length;
538 	u8 *miux_tlv, miux_length;
539 	__be16 wks = cpu_to_be16(local->local_wks);
540 	u8 gb_len = 0;
541 	int ret = 0;
542 
543 	version = LLCP_VERSION_11;
544 	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
545 					 1, &version_length);
546 	gb_len += version_length;
547 
548 	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
549 	gb_len += lto_length;
550 
551 	pr_debug("Local wks 0x%lx\n", local->local_wks);
552 	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
553 	gb_len += wks_length;
554 
555 	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
556 				      &miux_length);
557 	gb_len += miux_length;
558 
559 	gb_len += ARRAY_SIZE(llcp_magic);
560 
561 	if (gb_len > NFC_MAX_GT_LEN) {
562 		ret = -EINVAL;
563 		goto out;
564 	}
565 
566 	gb_cur = local->gb;
567 
568 	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
569 	gb_cur += ARRAY_SIZE(llcp_magic);
570 
571 	memcpy(gb_cur, version_tlv, version_length);
572 	gb_cur += version_length;
573 
574 	memcpy(gb_cur, lto_tlv, lto_length);
575 	gb_cur += lto_length;
576 
577 	memcpy(gb_cur, wks_tlv, wks_length);
578 	gb_cur += wks_length;
579 
580 	memcpy(gb_cur, miux_tlv, miux_length);
581 	gb_cur += miux_length;
582 
583 	local->gb_len = gb_len;
584 
585 out:
586 	kfree(version_tlv);
587 	kfree(lto_tlv);
588 	kfree(wks_tlv);
589 	kfree(miux_tlv);
590 
591 	return ret;
592 }
593 
594 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
595 {
596 	struct nfc_llcp_local *local;
597 
598 	local = nfc_llcp_find_local(dev);
599 	if (local == NULL) {
600 		*general_bytes_len = 0;
601 		return NULL;
602 	}
603 
604 	nfc_llcp_build_gb(local);
605 
606 	*general_bytes_len = local->gb_len;
607 
608 	return local->gb;
609 }
610 
611 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
612 {
613 	struct nfc_llcp_local *local;
614 
615 	if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
616 		return -EINVAL;
617 
618 	local = nfc_llcp_find_local(dev);
619 	if (local == NULL) {
620 		pr_err("No LLCP device\n");
621 		return -ENODEV;
622 	}
623 
624 	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
625 	memcpy(local->remote_gb, gb, gb_len);
626 	local->remote_gb_len = gb_len;
627 
628 	if (memcmp(local->remote_gb, llcp_magic, 3)) {
629 		pr_err("MAC does not support LLCP\n");
630 		return -EINVAL;
631 	}
632 
633 	return nfc_llcp_parse_gb_tlv(local,
634 				     &local->remote_gb[3],
635 				     local->remote_gb_len - 3);
636 }
637 
638 static u8 nfc_llcp_dsap(struct sk_buff *pdu)
639 {
640 	return (pdu->data[0] & 0xfc) >> 2;
641 }
642 
643 static u8 nfc_llcp_ptype(struct sk_buff *pdu)
644 {
645 	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
646 }
647 
648 static u8 nfc_llcp_ssap(struct sk_buff *pdu)
649 {
650 	return pdu->data[1] & 0x3f;
651 }
652 
653 static u8 nfc_llcp_ns(struct sk_buff *pdu)
654 {
655 	return pdu->data[2] >> 4;
656 }
657 
658 static u8 nfc_llcp_nr(struct sk_buff *pdu)
659 {
660 	return pdu->data[2] & 0xf;
661 }
662 
663 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
664 {
665 	pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
666 	sock->send_n = (sock->send_n + 1) % 16;
667 	sock->recv_ack_n = (sock->recv_n - 1) % 16;
668 }
669 
670 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
671 			       struct sk_buff *skb, u8 direction)
672 {
673 	struct sk_buff *skb_copy = NULL, *nskb;
674 	struct sock *sk;
675 	u8 *data;
676 
677 	read_lock(&local->raw_sockets.lock);
678 
679 	sk_for_each(sk, &local->raw_sockets.head) {
680 		if (sk->sk_state != LLCP_BOUND)
681 			continue;
682 
683 		if (skb_copy == NULL) {
684 			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
685 						      GFP_ATOMIC, true);
686 
687 			if (skb_copy == NULL)
688 				continue;
689 
690 			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
691 
692 			data[0] = local->dev ? local->dev->idx : 0xFF;
693 			data[1] = direction & 0x01;
694 			data[1] |= (RAW_PAYLOAD_LLCP << 1);
695 		}
696 
697 		nskb = skb_clone(skb_copy, GFP_ATOMIC);
698 		if (!nskb)
699 			continue;
700 
701 		if (sock_queue_rcv_skb(sk, nskb))
702 			kfree_skb(nskb);
703 	}
704 
705 	read_unlock(&local->raw_sockets.lock);
706 
707 	kfree_skb(skb_copy);
708 }
709 
710 static void nfc_llcp_tx_work(struct work_struct *work)
711 {
712 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
713 						    tx_work);
714 	struct sk_buff *skb;
715 	struct sock *sk;
716 	struct nfc_llcp_sock *llcp_sock;
717 
718 	skb = skb_dequeue(&local->tx_queue);
719 	if (skb != NULL) {
720 		sk = skb->sk;
721 		llcp_sock = nfc_llcp_sock(sk);
722 
723 		if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
724 			kfree_skb(skb);
725 			nfc_llcp_send_symm(local->dev);
726 		} else if (llcp_sock && !llcp_sock->remote_ready) {
727 			skb_queue_head(&local->tx_queue, skb);
728 			nfc_llcp_send_symm(local->dev);
729 		} else {
730 			struct sk_buff *copy_skb = NULL;
731 			u8 ptype = nfc_llcp_ptype(skb);
732 			int ret;
733 
734 			pr_debug("Sending pending skb\n");
735 			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
736 					     16, 1, skb->data, skb->len, true);
737 
738 			if (ptype == LLCP_PDU_DISC && sk != NULL &&
739 			    sk->sk_state == LLCP_DISCONNECTING) {
740 				nfc_llcp_sock_unlink(&local->sockets, sk);
741 				sock_orphan(sk);
742 				sock_put(sk);
743 			}
744 
745 			if (ptype == LLCP_PDU_I)
746 				copy_skb = skb_copy(skb, GFP_ATOMIC);
747 
748 			__net_timestamp(skb);
749 
750 			nfc_llcp_send_to_raw_sock(local, skb,
751 						  NFC_DIRECTION_TX);
752 
753 			ret = nfc_data_exchange(local->dev, local->target_idx,
754 						skb, nfc_llcp_recv, local);
755 
756 			if (ret) {
757 				kfree_skb(copy_skb);
758 				goto out;
759 			}
760 
761 			if (ptype == LLCP_PDU_I && copy_skb)
762 				skb_queue_tail(&llcp_sock->tx_pending_queue,
763 					       copy_skb);
764 		}
765 	} else {
766 		nfc_llcp_send_symm(local->dev);
767 	}
768 
769 out:
770 	mod_timer(&local->link_timer,
771 		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
772 }
773 
774 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
775 							  u8 ssap)
776 {
777 	struct sock *sk;
778 	struct nfc_llcp_sock *llcp_sock;
779 
780 	read_lock(&local->connecting_sockets.lock);
781 
782 	sk_for_each(sk, &local->connecting_sockets.head) {
783 		llcp_sock = nfc_llcp_sock(sk);
784 
785 		if (llcp_sock->ssap == ssap) {
786 			sock_hold(&llcp_sock->sk);
787 			goto out;
788 		}
789 	}
790 
791 	llcp_sock = NULL;
792 
793 out:
794 	read_unlock(&local->connecting_sockets.lock);
795 
796 	return llcp_sock;
797 }
798 
799 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
800 						  u8 *sn, size_t sn_len)
801 {
802 	struct nfc_llcp_sock *llcp_sock;
803 
804 	llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
805 
806 	if (llcp_sock == NULL)
807 		return NULL;
808 
809 	sock_hold(&llcp_sock->sk);
810 
811 	return llcp_sock;
812 }
813 
814 static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len)
815 {
816 	u8 *tlv = &skb->data[2], type, length;
817 	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
818 
819 	while (offset < tlv_array_len) {
820 		type = tlv[0];
821 		length = tlv[1];
822 
823 		pr_debug("type 0x%x length %d\n", type, length);
824 
825 		if (type == LLCP_TLV_SN) {
826 			*sn_len = length;
827 			return &tlv[2];
828 		}
829 
830 		offset += length + 2;
831 		tlv += length + 2;
832 	}
833 
834 	return NULL;
835 }
836 
837 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
838 			     struct sk_buff *skb)
839 {
840 	struct nfc_llcp_sock *llcp_sock;
841 	struct nfc_llcp_ui_cb *ui_cb;
842 	u8 dsap, ssap;
843 
844 	dsap = nfc_llcp_dsap(skb);
845 	ssap = nfc_llcp_ssap(skb);
846 
847 	ui_cb = nfc_llcp_ui_skb_cb(skb);
848 	ui_cb->dsap = dsap;
849 	ui_cb->ssap = ssap;
850 
851 	pr_debug("%d %d\n", dsap, ssap);
852 
853 	/* We're looking for a bound socket, not a client one */
854 	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
855 	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
856 		return;
857 
858 	/* There is no sequence with UI frames */
859 	skb_pull(skb, LLCP_HEADER_SIZE);
860 	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
861 		/*
862 		 * UI frames will be freed from the socket layer, so we
863 		 * need to keep them alive until someone receives them.
864 		 */
865 		skb_get(skb);
866 	} else {
867 		pr_err("Receive queue is full\n");
868 	}
869 
870 	nfc_llcp_sock_put(llcp_sock);
871 }
872 
873 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
874 				  struct sk_buff *skb)
875 {
876 	struct sock *new_sk, *parent;
877 	struct nfc_llcp_sock *sock, *new_sock;
878 	u8 dsap, ssap, reason;
879 
880 	dsap = nfc_llcp_dsap(skb);
881 	ssap = nfc_llcp_ssap(skb);
882 
883 	pr_debug("%d %d\n", dsap, ssap);
884 
885 	if (dsap != LLCP_SAP_SDP) {
886 		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
887 		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
888 			reason = LLCP_DM_NOBOUND;
889 			goto fail;
890 		}
891 	} else {
892 		u8 *sn;
893 		size_t sn_len;
894 
895 		sn = nfc_llcp_connect_sn(skb, &sn_len);
896 		if (sn == NULL) {
897 			reason = LLCP_DM_NOBOUND;
898 			goto fail;
899 		}
900 
901 		pr_debug("Service name length %zu\n", sn_len);
902 
903 		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
904 		if (sock == NULL) {
905 			reason = LLCP_DM_NOBOUND;
906 			goto fail;
907 		}
908 	}
909 
910 	lock_sock(&sock->sk);
911 
912 	parent = &sock->sk;
913 
914 	if (sk_acceptq_is_full(parent)) {
915 		reason = LLCP_DM_REJ;
916 		release_sock(&sock->sk);
917 		sock_put(&sock->sk);
918 		goto fail;
919 	}
920 
921 	if (sock->ssap == LLCP_SDP_UNBOUND) {
922 		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
923 
924 		pr_debug("First client, reserving %d\n", ssap);
925 
926 		if (ssap == LLCP_SAP_MAX) {
927 			reason = LLCP_DM_REJ;
928 			release_sock(&sock->sk);
929 			sock_put(&sock->sk);
930 			goto fail;
931 		}
932 
933 		sock->ssap = ssap;
934 	}
935 
936 	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
937 	if (new_sk == NULL) {
938 		reason = LLCP_DM_REJ;
939 		release_sock(&sock->sk);
940 		sock_put(&sock->sk);
941 		goto fail;
942 	}
943 
944 	new_sock = nfc_llcp_sock(new_sk);
945 	new_sock->dev = local->dev;
946 	new_sock->local = nfc_llcp_local_get(local);
947 	new_sock->rw = sock->rw;
948 	new_sock->miux = sock->miux;
949 	new_sock->nfc_protocol = sock->nfc_protocol;
950 	new_sock->dsap = ssap;
951 	new_sock->target_idx = local->target_idx;
952 	new_sock->parent = parent;
953 	new_sock->ssap = sock->ssap;
954 	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
955 		atomic_t *client_count;
956 
957 		pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
958 
959 		client_count =
960 			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
961 
962 		atomic_inc(client_count);
963 		new_sock->reserved_ssap = sock->ssap;
964 	}
965 
966 	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
967 				      skb->len - LLCP_HEADER_SIZE);
968 
969 	pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
970 
971 	nfc_llcp_sock_link(&local->sockets, new_sk);
972 
973 	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
974 
975 	nfc_get_device(local->dev->idx);
976 
977 	new_sk->sk_state = LLCP_CONNECTED;
978 
979 	/* Wake the listening processes */
980 	parent->sk_data_ready(parent);
981 
982 	/* Send CC */
983 	nfc_llcp_send_cc(new_sock);
984 
985 	release_sock(&sock->sk);
986 	sock_put(&sock->sk);
987 
988 	return;
989 
990 fail:
991 	/* Send DM */
992 	nfc_llcp_send_dm(local, dsap, ssap, reason);
993 }
994 
995 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
996 {
997 	int nr_frames = 0;
998 	struct nfc_llcp_local *local = sock->local;
999 
1000 	pr_debug("Remote ready %d tx queue len %d remote rw %d",
1001 		 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
1002 		 sock->remote_rw);
1003 
1004 	/* Try to queue some I frames for transmission */
1005 	while (sock->remote_ready &&
1006 	       skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {
1007 		struct sk_buff *pdu;
1008 
1009 		pdu = skb_dequeue(&sock->tx_queue);
1010 		if (pdu == NULL)
1011 			break;
1012 
1013 		/* Update N(S)/N(R) */
1014 		nfc_llcp_set_nrns(sock, pdu);
1015 
1016 		skb_queue_tail(&local->tx_queue, pdu);
1017 		nr_frames++;
1018 	}
1019 
1020 	return nr_frames;
1021 }
1022 
1023 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
1024 			       struct sk_buff *skb)
1025 {
1026 	struct nfc_llcp_sock *llcp_sock;
1027 	struct sock *sk;
1028 	u8 dsap, ssap, ptype, ns, nr;
1029 
1030 	ptype = nfc_llcp_ptype(skb);
1031 	dsap = nfc_llcp_dsap(skb);
1032 	ssap = nfc_llcp_ssap(skb);
1033 	ns = nfc_llcp_ns(skb);
1034 	nr = nfc_llcp_nr(skb);
1035 
1036 	pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
1037 
1038 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1039 	if (llcp_sock == NULL) {
1040 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1041 		return;
1042 	}
1043 
1044 	sk = &llcp_sock->sk;
1045 	lock_sock(sk);
1046 	if (sk->sk_state == LLCP_CLOSED) {
1047 		release_sock(sk);
1048 		nfc_llcp_sock_put(llcp_sock);
1049 	}
1050 
1051 	/* Pass the payload upstream */
1052 	if (ptype == LLCP_PDU_I) {
1053 		pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
1054 
1055 		if (ns == llcp_sock->recv_n)
1056 			llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
1057 		else
1058 			pr_err("Received out of sequence I PDU\n");
1059 
1060 		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
1061 		if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
1062 			/*
1063 			 * I frames will be freed from the socket layer, so we
1064 			 * need to keep them alive until someone receives them.
1065 			 */
1066 			skb_get(skb);
1067 		} else {
1068 			pr_err("Receive queue is full\n");
1069 		}
1070 	}
1071 
1072 	/* Remove skbs from the pending queue */
1073 	if (llcp_sock->send_ack_n != nr) {
1074 		struct sk_buff *s, *tmp;
1075 		u8 n;
1076 
1077 		llcp_sock->send_ack_n = nr;
1078 
1079 		/* Remove and free all skbs until ns == nr */
1080 		skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
1081 			n = nfc_llcp_ns(s);
1082 
1083 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1084 			kfree_skb(s);
1085 
1086 			if (n == nr)
1087 				break;
1088 		}
1089 
1090 		/* Re-queue the remaining skbs for transmission */
1091 		skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1092 					    s, tmp) {
1093 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1094 			skb_queue_head(&local->tx_queue, s);
1095 		}
1096 	}
1097 
1098 	if (ptype == LLCP_PDU_RR)
1099 		llcp_sock->remote_ready = true;
1100 	else if (ptype == LLCP_PDU_RNR)
1101 		llcp_sock->remote_ready = false;
1102 
1103 	if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1104 		nfc_llcp_send_rr(llcp_sock);
1105 
1106 	release_sock(sk);
1107 	nfc_llcp_sock_put(llcp_sock);
1108 }
1109 
1110 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1111 			       struct sk_buff *skb)
1112 {
1113 	struct nfc_llcp_sock *llcp_sock;
1114 	struct sock *sk;
1115 	u8 dsap, ssap;
1116 
1117 	dsap = nfc_llcp_dsap(skb);
1118 	ssap = nfc_llcp_ssap(skb);
1119 
1120 	if ((dsap == 0) && (ssap == 0)) {
1121 		pr_debug("Connection termination");
1122 		nfc_dep_link_down(local->dev);
1123 		return;
1124 	}
1125 
1126 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1127 	if (llcp_sock == NULL) {
1128 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1129 		return;
1130 	}
1131 
1132 	sk = &llcp_sock->sk;
1133 	lock_sock(sk);
1134 
1135 	nfc_llcp_socket_purge(llcp_sock);
1136 
1137 	if (sk->sk_state == LLCP_CLOSED) {
1138 		release_sock(sk);
1139 		nfc_llcp_sock_put(llcp_sock);
1140 	}
1141 
1142 	if (sk->sk_state == LLCP_CONNECTED) {
1143 		nfc_put_device(local->dev);
1144 		sk->sk_state = LLCP_CLOSED;
1145 		sk->sk_state_change(sk);
1146 	}
1147 
1148 	nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1149 
1150 	release_sock(sk);
1151 	nfc_llcp_sock_put(llcp_sock);
1152 }
1153 
1154 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb)
1155 {
1156 	struct nfc_llcp_sock *llcp_sock;
1157 	struct sock *sk;
1158 	u8 dsap, ssap;
1159 
1160 	dsap = nfc_llcp_dsap(skb);
1161 	ssap = nfc_llcp_ssap(skb);
1162 
1163 	llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1164 	if (llcp_sock == NULL) {
1165 		pr_err("Invalid CC\n");
1166 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1167 
1168 		return;
1169 	}
1170 
1171 	sk = &llcp_sock->sk;
1172 
1173 	/* Unlink from connecting and link to the client array */
1174 	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1175 	nfc_llcp_sock_link(&local->sockets, sk);
1176 	llcp_sock->dsap = ssap;
1177 
1178 	nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1179 				      skb->len - LLCP_HEADER_SIZE);
1180 
1181 	sk->sk_state = LLCP_CONNECTED;
1182 	sk->sk_state_change(sk);
1183 
1184 	nfc_llcp_sock_put(llcp_sock);
1185 }
1186 
1187 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, struct sk_buff *skb)
1188 {
1189 	struct nfc_llcp_sock *llcp_sock;
1190 	struct sock *sk;
1191 	u8 dsap, ssap, reason;
1192 
1193 	dsap = nfc_llcp_dsap(skb);
1194 	ssap = nfc_llcp_ssap(skb);
1195 	reason = skb->data[2];
1196 
1197 	pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1198 
1199 	switch (reason) {
1200 	case LLCP_DM_NOBOUND:
1201 	case LLCP_DM_REJ:
1202 		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1203 		break;
1204 
1205 	default:
1206 		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1207 		break;
1208 	}
1209 
1210 	if (llcp_sock == NULL) {
1211 		pr_debug("Already closed\n");
1212 		return;
1213 	}
1214 
1215 	sk = &llcp_sock->sk;
1216 
1217 	sk->sk_err = ENXIO;
1218 	sk->sk_state = LLCP_CLOSED;
1219 	sk->sk_state_change(sk);
1220 
1221 	nfc_llcp_sock_put(llcp_sock);
1222 }
1223 
1224 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1225 			      struct sk_buff *skb)
1226 {
1227 	struct nfc_llcp_sock *llcp_sock;
1228 	u8 dsap, ssap, *tlv, type, length, tid, sap;
1229 	u16 tlv_len, offset;
1230 	char *service_name;
1231 	size_t service_name_len;
1232 	struct nfc_llcp_sdp_tlv *sdp;
1233 	HLIST_HEAD(llc_sdres_list);
1234 	size_t sdres_tlvs_len;
1235 	HLIST_HEAD(nl_sdres_list);
1236 
1237 	dsap = nfc_llcp_dsap(skb);
1238 	ssap = nfc_llcp_ssap(skb);
1239 
1240 	pr_debug("%d %d\n", dsap, ssap);
1241 
1242 	if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1243 		pr_err("Wrong SNL SAP\n");
1244 		return;
1245 	}
1246 
1247 	tlv = &skb->data[LLCP_HEADER_SIZE];
1248 	tlv_len = skb->len - LLCP_HEADER_SIZE;
1249 	offset = 0;
1250 	sdres_tlvs_len = 0;
1251 
1252 	while (offset < tlv_len) {
1253 		type = tlv[0];
1254 		length = tlv[1];
1255 
1256 		switch (type) {
1257 		case LLCP_TLV_SDREQ:
1258 			tid = tlv[2];
1259 			service_name = (char *) &tlv[3];
1260 			service_name_len = length - 1;
1261 
1262 			pr_debug("Looking for %.16s\n", service_name);
1263 
1264 			if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1265 			    !strncmp(service_name, "urn:nfc:sn:sdp",
1266 				     service_name_len)) {
1267 				sap = 1;
1268 				goto add_snl;
1269 			}
1270 
1271 			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1272 							  service_name_len);
1273 			if (!llcp_sock) {
1274 				sap = 0;
1275 				goto add_snl;
1276 			}
1277 
1278 			/*
1279 			 * We found a socket but its ssap has not been reserved
1280 			 * yet. We need to assign it for good and send a reply.
1281 			 * The ssap will be freed when the socket is closed.
1282 			 */
1283 			if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1284 				atomic_t *client_count;
1285 
1286 				sap = nfc_llcp_reserve_sdp_ssap(local);
1287 
1288 				pr_debug("Reserving %d\n", sap);
1289 
1290 				if (sap == LLCP_SAP_MAX) {
1291 					sap = 0;
1292 					goto add_snl;
1293 				}
1294 
1295 				client_count =
1296 					&local->local_sdp_cnt[sap -
1297 							      LLCP_WKS_NUM_SAP];
1298 
1299 				atomic_inc(client_count);
1300 
1301 				llcp_sock->ssap = sap;
1302 				llcp_sock->reserved_ssap = sap;
1303 			} else {
1304 				sap = llcp_sock->ssap;
1305 			}
1306 
1307 			pr_debug("%p %d\n", llcp_sock, sap);
1308 
1309 add_snl:
1310 			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
1311 			if (sdp == NULL)
1312 				goto exit;
1313 
1314 			sdres_tlvs_len += sdp->tlv_len;
1315 			hlist_add_head(&sdp->node, &llc_sdres_list);
1316 			break;
1317 
1318 		case LLCP_TLV_SDRES:
1319 			mutex_lock(&local->sdreq_lock);
1320 
1321 			pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]);
1322 
1323 			hlist_for_each_entry(sdp, &local->pending_sdreqs, node) {
1324 				if (sdp->tid != tlv[2])
1325 					continue;
1326 
1327 				sdp->sap = tlv[3];
1328 
1329 				pr_debug("Found: uri=%s, sap=%d\n",
1330 					 sdp->uri, sdp->sap);
1331 
1332 				hlist_del(&sdp->node);
1333 
1334 				hlist_add_head(&sdp->node, &nl_sdres_list);
1335 
1336 				break;
1337 			}
1338 
1339 			mutex_unlock(&local->sdreq_lock);
1340 			break;
1341 
1342 		default:
1343 			pr_err("Invalid SNL tlv value 0x%x\n", type);
1344 			break;
1345 		}
1346 
1347 		offset += length + 2;
1348 		tlv += length + 2;
1349 	}
1350 
1351 exit:
1352 	if (!hlist_empty(&nl_sdres_list))
1353 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
1354 
1355 	if (!hlist_empty(&llc_sdres_list))
1356 		nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);
1357 }
1358 
1359 static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
1360 {
1361 	u8 ptype;
1362 	u16 pdu_len;
1363 	struct sk_buff *new_skb;
1364 
1365 	if (skb->len <= LLCP_HEADER_SIZE) {
1366 		pr_err("Malformed AGF PDU\n");
1367 		return;
1368 	}
1369 
1370 	skb_pull(skb, LLCP_HEADER_SIZE);
1371 
1372 	while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) {
1373 		pdu_len = skb->data[0] << 8 | skb->data[1];
1374 
1375 		skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE);
1376 
1377 		if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) {
1378 			pr_err("Malformed AGF PDU\n");
1379 			return;
1380 		}
1381 
1382 		ptype = nfc_llcp_ptype(skb);
1383 
1384 		if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF)
1385 			goto next;
1386 
1387 		new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
1388 		if (new_skb == NULL) {
1389 			pr_err("Could not allocate PDU\n");
1390 			return;
1391 		}
1392 
1393 		memcpy(skb_put(new_skb, pdu_len), skb->data, pdu_len);
1394 
1395 		nfc_llcp_rx_skb(local, new_skb);
1396 
1397 		kfree_skb(new_skb);
1398 next:
1399 		skb_pull(skb, pdu_len);
1400 	}
1401 }
1402 
1403 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
1404 {
1405 	u8 dsap, ssap, ptype;
1406 
1407 	ptype = nfc_llcp_ptype(skb);
1408 	dsap = nfc_llcp_dsap(skb);
1409 	ssap = nfc_llcp_ssap(skb);
1410 
1411 	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1412 
1413 	if (ptype != LLCP_PDU_SYMM)
1414 		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
1415 				     skb->data, skb->len, true);
1416 
1417 	switch (ptype) {
1418 	case LLCP_PDU_SYMM:
1419 		pr_debug("SYMM\n");
1420 		break;
1421 
1422 	case LLCP_PDU_UI:
1423 		pr_debug("UI\n");
1424 		nfc_llcp_recv_ui(local, skb);
1425 		break;
1426 
1427 	case LLCP_PDU_CONNECT:
1428 		pr_debug("CONNECT\n");
1429 		nfc_llcp_recv_connect(local, skb);
1430 		break;
1431 
1432 	case LLCP_PDU_DISC:
1433 		pr_debug("DISC\n");
1434 		nfc_llcp_recv_disc(local, skb);
1435 		break;
1436 
1437 	case LLCP_PDU_CC:
1438 		pr_debug("CC\n");
1439 		nfc_llcp_recv_cc(local, skb);
1440 		break;
1441 
1442 	case LLCP_PDU_DM:
1443 		pr_debug("DM\n");
1444 		nfc_llcp_recv_dm(local, skb);
1445 		break;
1446 
1447 	case LLCP_PDU_SNL:
1448 		pr_debug("SNL\n");
1449 		nfc_llcp_recv_snl(local, skb);
1450 		break;
1451 
1452 	case LLCP_PDU_I:
1453 	case LLCP_PDU_RR:
1454 	case LLCP_PDU_RNR:
1455 		pr_debug("I frame\n");
1456 		nfc_llcp_recv_hdlc(local, skb);
1457 		break;
1458 
1459 	case LLCP_PDU_AGF:
1460 		pr_debug("AGF frame\n");
1461 		nfc_llcp_recv_agf(local, skb);
1462 		break;
1463 	}
1464 }
1465 
1466 static void nfc_llcp_rx_work(struct work_struct *work)
1467 {
1468 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1469 						    rx_work);
1470 	struct sk_buff *skb;
1471 
1472 	skb = local->rx_pending;
1473 	if (skb == NULL) {
1474 		pr_debug("No pending SKB\n");
1475 		return;
1476 	}
1477 
1478 	__net_timestamp(skb);
1479 
1480 	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);
1481 
1482 	nfc_llcp_rx_skb(local, skb);
1483 
1484 	schedule_work(&local->tx_work);
1485 	kfree_skb(local->rx_pending);
1486 	local->rx_pending = NULL;
1487 }
1488 
1489 static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
1490 {
1491 	local->rx_pending = skb;
1492 	del_timer(&local->link_timer);
1493 	schedule_work(&local->rx_work);
1494 }
1495 
1496 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1497 {
1498 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1499 
1500 	pr_debug("Received an LLCP PDU\n");
1501 	if (err < 0) {
1502 		pr_err("err %d\n", err);
1503 		return;
1504 	}
1505 
1506 	__nfc_llcp_recv(local, skb);
1507 }
1508 
1509 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1510 {
1511 	struct nfc_llcp_local *local;
1512 
1513 	local = nfc_llcp_find_local(dev);
1514 	if (local == NULL) {
1515 		kfree_skb(skb);
1516 		return -ENODEV;
1517 	}
1518 
1519 	__nfc_llcp_recv(local, skb);
1520 
1521 	return 0;
1522 }
1523 
1524 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1525 {
1526 	struct nfc_llcp_local *local;
1527 
1528 	local = nfc_llcp_find_local(dev);
1529 	if (local == NULL)
1530 		return;
1531 
1532 	local->remote_miu = LLCP_DEFAULT_MIU;
1533 	local->remote_lto = LLCP_DEFAULT_LTO;
1534 
1535 	/* Close and purge all existing sockets */
1536 	nfc_llcp_socket_release(local, true, 0);
1537 }
1538 
1539 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1540 			u8 comm_mode, u8 rf_mode)
1541 {
1542 	struct nfc_llcp_local *local;
1543 
1544 	pr_debug("rf mode %d\n", rf_mode);
1545 
1546 	local = nfc_llcp_find_local(dev);
1547 	if (local == NULL)
1548 		return;
1549 
1550 	local->target_idx = target_idx;
1551 	local->comm_mode = comm_mode;
1552 	local->rf_mode = rf_mode;
1553 
1554 	if (rf_mode == NFC_RF_INITIATOR) {
1555 		pr_debug("Queueing Tx work\n");
1556 
1557 		schedule_work(&local->tx_work);
1558 	} else {
1559 		mod_timer(&local->link_timer,
1560 			  jiffies + msecs_to_jiffies(local->remote_lto));
1561 	}
1562 }
1563 
1564 int nfc_llcp_register_device(struct nfc_dev *ndev)
1565 {
1566 	struct nfc_llcp_local *local;
1567 
1568 	local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1569 	if (local == NULL)
1570 		return -ENOMEM;
1571 
1572 	local->dev = ndev;
1573 	INIT_LIST_HEAD(&local->list);
1574 	kref_init(&local->ref);
1575 	mutex_init(&local->sdp_lock);
1576 	init_timer(&local->link_timer);
1577 	local->link_timer.data = (unsigned long) local;
1578 	local->link_timer.function = nfc_llcp_symm_timer;
1579 
1580 	skb_queue_head_init(&local->tx_queue);
1581 	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1582 
1583 	local->rx_pending = NULL;
1584 	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1585 
1586 	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1587 
1588 	rwlock_init(&local->sockets.lock);
1589 	rwlock_init(&local->connecting_sockets.lock);
1590 	rwlock_init(&local->raw_sockets.lock);
1591 
1592 	local->lto = 150; /* 1500 ms */
1593 	local->rw = LLCP_MAX_RW;
1594 	local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1595 	local->local_wks = 0x1; /* LLC Link Management */
1596 
1597 	nfc_llcp_build_gb(local);
1598 
1599 	local->remote_miu = LLCP_DEFAULT_MIU;
1600 	local->remote_lto = LLCP_DEFAULT_LTO;
1601 
1602 	mutex_init(&local->sdreq_lock);
1603 	INIT_HLIST_HEAD(&local->pending_sdreqs);
1604 	init_timer(&local->sdreq_timer);
1605 	local->sdreq_timer.data = (unsigned long) local;
1606 	local->sdreq_timer.function = nfc_llcp_sdreq_timer;
1607 	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
1608 
1609 	list_add(&local->list, &llcp_devices);
1610 
1611 	return 0;
1612 }
1613 
1614 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1615 {
1616 	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
1617 
1618 	if (local == NULL) {
1619 		pr_debug("No such device\n");
1620 		return;
1621 	}
1622 
1623 	local_cleanup(local);
1624 
1625 	nfc_llcp_local_put(local);
1626 }
1627 
1628 int __init nfc_llcp_init(void)
1629 {
1630 	return nfc_llcp_sock_init();
1631 }
1632 
1633 void nfc_llcp_exit(void)
1634 {
1635 	nfc_llcp_sock_exit();
1636 }
1637