xref: /linux/net/nfc/llcp_core.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * Copyright (C) 2011  Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the
16  * Free Software Foundation, Inc.,
17  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18  */
19 
20 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
21 
22 #include <linux/init.h>
23 #include <linux/kernel.h>
24 #include <linux/list.h>
25 #include <linux/nfc.h>
26 
27 #include "nfc.h"
28 #include "llcp.h"
29 
30 static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
31 
32 static struct list_head llcp_devices;
33 
34 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb);
35 
36 void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)
37 {
38 	write_lock(&l->lock);
39 	sk_add_node(sk, &l->head);
40 	write_unlock(&l->lock);
41 }
42 
43 void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
44 {
45 	write_lock(&l->lock);
46 	sk_del_node_init(sk);
47 	write_unlock(&l->lock);
48 }
49 
50 void nfc_llcp_socket_remote_param_init(struct nfc_llcp_sock *sock)
51 {
52 	sock->remote_rw = LLCP_DEFAULT_RW;
53 	sock->remote_miu = LLCP_MAX_MIU + 1;
54 }
55 
56 static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock)
57 {
58 	struct nfc_llcp_local *local = sock->local;
59 	struct sk_buff *s, *tmp;
60 
61 	pr_debug("%p\n", &sock->sk);
62 
63 	skb_queue_purge(&sock->tx_queue);
64 	skb_queue_purge(&sock->tx_pending_queue);
65 
66 	if (local == NULL)
67 		return;
68 
69 	/* Search for local pending SKBs that are related to this socket */
70 	skb_queue_walk_safe(&local->tx_queue, s, tmp) {
71 		if (s->sk != &sock->sk)
72 			continue;
73 
74 		skb_unlink(s, &local->tx_queue);
75 		kfree_skb(s);
76 	}
77 }
78 
79 static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device,
80 				    int err)
81 {
82 	struct sock *sk;
83 	struct hlist_node *tmp;
84 	struct nfc_llcp_sock *llcp_sock;
85 
86 	skb_queue_purge(&local->tx_queue);
87 
88 	write_lock(&local->sockets.lock);
89 
90 	sk_for_each_safe(sk, tmp, &local->sockets.head) {
91 		llcp_sock = nfc_llcp_sock(sk);
92 
93 		bh_lock_sock(sk);
94 
95 		nfc_llcp_socket_purge(llcp_sock);
96 
97 		if (sk->sk_state == LLCP_CONNECTED)
98 			nfc_put_device(llcp_sock->dev);
99 
100 		if (sk->sk_state == LLCP_LISTEN) {
101 			struct nfc_llcp_sock *lsk, *n;
102 			struct sock *accept_sk;
103 
104 			list_for_each_entry_safe(lsk, n,
105 						 &llcp_sock->accept_queue,
106 						 accept_queue) {
107 				accept_sk = &lsk->sk;
108 				bh_lock_sock(accept_sk);
109 
110 				nfc_llcp_accept_unlink(accept_sk);
111 
112 				if (err)
113 					accept_sk->sk_err = err;
114 				accept_sk->sk_state = LLCP_CLOSED;
115 				accept_sk->sk_state_change(sk);
116 
117 				bh_unlock_sock(accept_sk);
118 			}
119 		}
120 
121 		if (err)
122 			sk->sk_err = err;
123 		sk->sk_state = LLCP_CLOSED;
124 		sk->sk_state_change(sk);
125 
126 		bh_unlock_sock(sk);
127 
128 		sk_del_node_init(sk);
129 	}
130 
131 	write_unlock(&local->sockets.lock);
132 
133 	/* If we still have a device, we keep the RAW sockets alive */
134 	if (device == true)
135 		return;
136 
137 	write_lock(&local->raw_sockets.lock);
138 
139 	sk_for_each_safe(sk, tmp, &local->raw_sockets.head) {
140 		llcp_sock = nfc_llcp_sock(sk);
141 
142 		bh_lock_sock(sk);
143 
144 		nfc_llcp_socket_purge(llcp_sock);
145 
146 		if (err)
147 			sk->sk_err = err;
148 		sk->sk_state = LLCP_CLOSED;
149 		sk->sk_state_change(sk);
150 
151 		bh_unlock_sock(sk);
152 
153 		sk_del_node_init(sk);
154 	}
155 
156 	write_unlock(&local->raw_sockets.lock);
157 }
158 
159 struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
160 {
161 	kref_get(&local->ref);
162 
163 	return local;
164 }
165 
166 static void local_cleanup(struct nfc_llcp_local *local)
167 {
168 	nfc_llcp_socket_release(local, false, ENXIO);
169 	del_timer_sync(&local->link_timer);
170 	skb_queue_purge(&local->tx_queue);
171 	cancel_work_sync(&local->tx_work);
172 	cancel_work_sync(&local->rx_work);
173 	cancel_work_sync(&local->timeout_work);
174 	kfree_skb(local->rx_pending);
175 	del_timer_sync(&local->sdreq_timer);
176 	cancel_work_sync(&local->sdreq_timeout_work);
177 	nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);
178 }
179 
180 static void local_release(struct kref *ref)
181 {
182 	struct nfc_llcp_local *local;
183 
184 	local = container_of(ref, struct nfc_llcp_local, ref);
185 
186 	list_del(&local->list);
187 	local_cleanup(local);
188 	kfree(local);
189 }
190 
191 int nfc_llcp_local_put(struct nfc_llcp_local *local)
192 {
193 	if (local == NULL)
194 		return 0;
195 
196 	return kref_put(&local->ref, local_release);
197 }
198 
199 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
200 					       u8 ssap, u8 dsap)
201 {
202 	struct sock *sk;
203 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
204 
205 	pr_debug("ssap dsap %d %d\n", ssap, dsap);
206 
207 	if (ssap == 0 && dsap == 0)
208 		return NULL;
209 
210 	read_lock(&local->sockets.lock);
211 
212 	llcp_sock = NULL;
213 
214 	sk_for_each(sk, &local->sockets.head) {
215 		tmp_sock = nfc_llcp_sock(sk);
216 
217 		if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
218 			llcp_sock = tmp_sock;
219 			break;
220 		}
221 	}
222 
223 	read_unlock(&local->sockets.lock);
224 
225 	if (llcp_sock == NULL)
226 		return NULL;
227 
228 	sock_hold(&llcp_sock->sk);
229 
230 	return llcp_sock;
231 }
232 
233 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
234 {
235 	sock_put(&sock->sk);
236 }
237 
238 static void nfc_llcp_timeout_work(struct work_struct *work)
239 {
240 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
241 						    timeout_work);
242 
243 	nfc_dep_link_down(local->dev);
244 }
245 
246 static void nfc_llcp_symm_timer(unsigned long data)
247 {
248 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
249 
250 	pr_err("SYMM timeout\n");
251 
252 	schedule_work(&local->timeout_work);
253 }
254 
255 static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
256 {
257 	unsigned long time;
258 	HLIST_HEAD(nl_sdres_list);
259 	struct hlist_node *n;
260 	struct nfc_llcp_sdp_tlv *sdp;
261 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
262 						    sdreq_timeout_work);
263 
264 	mutex_lock(&local->sdreq_lock);
265 
266 	time = jiffies - msecs_to_jiffies(3 * local->remote_lto);
267 
268 	hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) {
269 		if (time_after(sdp->time, time))
270 			continue;
271 
272 		sdp->sap = LLCP_SDP_UNBOUND;
273 
274 		hlist_del(&sdp->node);
275 
276 		hlist_add_head(&sdp->node, &nl_sdres_list);
277 	}
278 
279 	if (!hlist_empty(&local->pending_sdreqs))
280 		mod_timer(&local->sdreq_timer,
281 			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
282 
283 	mutex_unlock(&local->sdreq_lock);
284 
285 	if (!hlist_empty(&nl_sdres_list))
286 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
287 }
288 
289 static void nfc_llcp_sdreq_timer(unsigned long data)
290 {
291 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
292 
293 	schedule_work(&local->sdreq_timeout_work);
294 }
295 
296 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
297 {
298 	struct nfc_llcp_local *local, *n;
299 
300 	list_for_each_entry_safe(local, n, &llcp_devices, list)
301 		if (local->dev == dev)
302 			return local;
303 
304 	pr_debug("No device found\n");
305 
306 	return NULL;
307 }
308 
309 static char *wks[] = {
310 	NULL,
311 	NULL, /* SDP */
312 	"urn:nfc:sn:ip",
313 	"urn:nfc:sn:obex",
314 	"urn:nfc:sn:snep",
315 };
316 
317 static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
318 {
319 	int sap, num_wks;
320 
321 	pr_debug("%s\n", service_name);
322 
323 	if (service_name == NULL)
324 		return -EINVAL;
325 
326 	num_wks = ARRAY_SIZE(wks);
327 
328 	for (sap = 0; sap < num_wks; sap++) {
329 		if (wks[sap] == NULL)
330 			continue;
331 
332 		if (strncmp(wks[sap], service_name, service_name_len) == 0)
333 			return sap;
334 	}
335 
336 	return -EINVAL;
337 }
338 
339 static
340 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
341 					    u8 *sn, size_t sn_len)
342 {
343 	struct sock *sk;
344 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
345 
346 	pr_debug("sn %zd %p\n", sn_len, sn);
347 
348 	if (sn == NULL || sn_len == 0)
349 		return NULL;
350 
351 	read_lock(&local->sockets.lock);
352 
353 	llcp_sock = NULL;
354 
355 	sk_for_each(sk, &local->sockets.head) {
356 		tmp_sock = nfc_llcp_sock(sk);
357 
358 		pr_debug("llcp sock %p\n", tmp_sock);
359 
360 		if (tmp_sock->sk.sk_type == SOCK_STREAM &&
361 		    tmp_sock->sk.sk_state != LLCP_LISTEN)
362 			continue;
363 
364 		if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
365 		    tmp_sock->sk.sk_state != LLCP_BOUND)
366 			continue;
367 
368 		if (tmp_sock->service_name == NULL ||
369 		    tmp_sock->service_name_len == 0)
370 			continue;
371 
372 		if (tmp_sock->service_name_len != sn_len)
373 			continue;
374 
375 		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
376 			llcp_sock = tmp_sock;
377 			break;
378 		}
379 	}
380 
381 	read_unlock(&local->sockets.lock);
382 
383 	pr_debug("Found llcp sock %p\n", llcp_sock);
384 
385 	return llcp_sock;
386 }
387 
388 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
389 			 struct nfc_llcp_sock *sock)
390 {
391 	mutex_lock(&local->sdp_lock);
392 
393 	if (sock->service_name != NULL && sock->service_name_len > 0) {
394 		int ssap = nfc_llcp_wks_sap(sock->service_name,
395 					    sock->service_name_len);
396 
397 		if (ssap > 0) {
398 			pr_debug("WKS %d\n", ssap);
399 
400 			/* This is a WKS, let's check if it's free */
401 			if (local->local_wks & BIT(ssap)) {
402 				mutex_unlock(&local->sdp_lock);
403 
404 				return LLCP_SAP_MAX;
405 			}
406 
407 			set_bit(ssap, &local->local_wks);
408 			mutex_unlock(&local->sdp_lock);
409 
410 			return ssap;
411 		}
412 
413 		/*
414 		 * Check if there already is a non WKS socket bound
415 		 * to this service name.
416 		 */
417 		if (nfc_llcp_sock_from_sn(local, sock->service_name,
418 					  sock->service_name_len) != NULL) {
419 			mutex_unlock(&local->sdp_lock);
420 
421 			return LLCP_SAP_MAX;
422 		}
423 
424 		mutex_unlock(&local->sdp_lock);
425 
426 		return LLCP_SDP_UNBOUND;
427 
428 	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
429 		if (!test_bit(sock->ssap, &local->local_wks)) {
430 			set_bit(sock->ssap, &local->local_wks);
431 			mutex_unlock(&local->sdp_lock);
432 
433 			return sock->ssap;
434 		}
435 	}
436 
437 	mutex_unlock(&local->sdp_lock);
438 
439 	return LLCP_SAP_MAX;
440 }
441 
442 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
443 {
444 	u8 local_ssap;
445 
446 	mutex_lock(&local->sdp_lock);
447 
448 	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
449 	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
450 		mutex_unlock(&local->sdp_lock);
451 		return LLCP_SAP_MAX;
452 	}
453 
454 	set_bit(local_ssap, &local->local_sap);
455 
456 	mutex_unlock(&local->sdp_lock);
457 
458 	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
459 }
460 
461 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
462 {
463 	u8 local_ssap;
464 	unsigned long *sdp;
465 
466 	if (ssap < LLCP_WKS_NUM_SAP) {
467 		local_ssap = ssap;
468 		sdp = &local->local_wks;
469 	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
470 		atomic_t *client_cnt;
471 
472 		local_ssap = ssap - LLCP_WKS_NUM_SAP;
473 		sdp = &local->local_sdp;
474 		client_cnt = &local->local_sdp_cnt[local_ssap];
475 
476 		pr_debug("%d clients\n", atomic_read(client_cnt));
477 
478 		mutex_lock(&local->sdp_lock);
479 
480 		if (atomic_dec_and_test(client_cnt)) {
481 			struct nfc_llcp_sock *l_sock;
482 
483 			pr_debug("No more clients for SAP %d\n", ssap);
484 
485 			clear_bit(local_ssap, sdp);
486 
487 			/* Find the listening sock and set it back to UNBOUND */
488 			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
489 			if (l_sock) {
490 				l_sock->ssap = LLCP_SDP_UNBOUND;
491 				nfc_llcp_sock_put(l_sock);
492 			}
493 		}
494 
495 		mutex_unlock(&local->sdp_lock);
496 
497 		return;
498 	} else if (ssap < LLCP_MAX_SAP) {
499 		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
500 		sdp = &local->local_sap;
501 	} else {
502 		return;
503 	}
504 
505 	mutex_lock(&local->sdp_lock);
506 
507 	clear_bit(local_ssap, sdp);
508 
509 	mutex_unlock(&local->sdp_lock);
510 }
511 
512 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
513 {
514 	u8 ssap;
515 
516 	mutex_lock(&local->sdp_lock);
517 
518 	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
519 	if (ssap == LLCP_SDP_NUM_SAP) {
520 		mutex_unlock(&local->sdp_lock);
521 
522 		return LLCP_SAP_MAX;
523 	}
524 
525 	pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
526 
527 	set_bit(ssap, &local->local_sdp);
528 
529 	mutex_unlock(&local->sdp_lock);
530 
531 	return LLCP_WKS_NUM_SAP + ssap;
532 }
533 
534 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
535 {
536 	u8 *gb_cur, *version_tlv, version, version_length;
537 	u8 *lto_tlv, lto_length;
538 	u8 *wks_tlv, wks_length;
539 	u8 *miux_tlv, miux_length;
540 	__be16 wks = cpu_to_be16(local->local_wks);
541 	u8 gb_len = 0;
542 	int ret = 0;
543 
544 	version = LLCP_VERSION_11;
545 	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
546 					 1, &version_length);
547 	gb_len += version_length;
548 
549 	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
550 	gb_len += lto_length;
551 
552 	pr_debug("Local wks 0x%lx\n", local->local_wks);
553 	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
554 	gb_len += wks_length;
555 
556 	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
557 				      &miux_length);
558 	gb_len += miux_length;
559 
560 	gb_len += ARRAY_SIZE(llcp_magic);
561 
562 	if (gb_len > NFC_MAX_GT_LEN) {
563 		ret = -EINVAL;
564 		goto out;
565 	}
566 
567 	gb_cur = local->gb;
568 
569 	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
570 	gb_cur += ARRAY_SIZE(llcp_magic);
571 
572 	memcpy(gb_cur, version_tlv, version_length);
573 	gb_cur += version_length;
574 
575 	memcpy(gb_cur, lto_tlv, lto_length);
576 	gb_cur += lto_length;
577 
578 	memcpy(gb_cur, wks_tlv, wks_length);
579 	gb_cur += wks_length;
580 
581 	memcpy(gb_cur, miux_tlv, miux_length);
582 	gb_cur += miux_length;
583 
584 	local->gb_len = gb_len;
585 
586 out:
587 	kfree(version_tlv);
588 	kfree(lto_tlv);
589 	kfree(wks_tlv);
590 	kfree(miux_tlv);
591 
592 	return ret;
593 }
594 
595 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
596 {
597 	struct nfc_llcp_local *local;
598 
599 	local = nfc_llcp_find_local(dev);
600 	if (local == NULL) {
601 		*general_bytes_len = 0;
602 		return NULL;
603 	}
604 
605 	nfc_llcp_build_gb(local);
606 
607 	*general_bytes_len = local->gb_len;
608 
609 	return local->gb;
610 }
611 
612 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
613 {
614 	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
615 
616 	if (local == NULL) {
617 		pr_err("No LLCP device\n");
618 		return -ENODEV;
619 	}
620 	if (gb_len < 3)
621 		return -EINVAL;
622 
623 	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
624 	memcpy(local->remote_gb, gb, gb_len);
625 	local->remote_gb_len = gb_len;
626 
627 	if (memcmp(local->remote_gb, llcp_magic, 3)) {
628 		pr_err("MAC does not support LLCP\n");
629 		return -EINVAL;
630 	}
631 
632 	return nfc_llcp_parse_gb_tlv(local,
633 				     &local->remote_gb[3],
634 				     local->remote_gb_len - 3);
635 }
636 
637 static u8 nfc_llcp_dsap(struct sk_buff *pdu)
638 {
639 	return (pdu->data[0] & 0xfc) >> 2;
640 }
641 
642 static u8 nfc_llcp_ptype(struct sk_buff *pdu)
643 {
644 	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
645 }
646 
647 static u8 nfc_llcp_ssap(struct sk_buff *pdu)
648 {
649 	return pdu->data[1] & 0x3f;
650 }
651 
652 static u8 nfc_llcp_ns(struct sk_buff *pdu)
653 {
654 	return pdu->data[2] >> 4;
655 }
656 
657 static u8 nfc_llcp_nr(struct sk_buff *pdu)
658 {
659 	return pdu->data[2] & 0xf;
660 }
661 
662 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
663 {
664 	pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
665 	sock->send_n = (sock->send_n + 1) % 16;
666 	sock->recv_ack_n = (sock->recv_n - 1) % 16;
667 }
668 
669 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
670 			       struct sk_buff *skb, u8 direction)
671 {
672 	struct sk_buff *skb_copy = NULL, *nskb;
673 	struct sock *sk;
674 	u8 *data;
675 
676 	read_lock(&local->raw_sockets.lock);
677 
678 	sk_for_each(sk, &local->raw_sockets.head) {
679 		if (sk->sk_state != LLCP_BOUND)
680 			continue;
681 
682 		if (skb_copy == NULL) {
683 			skb_copy = __pskb_copy(skb, NFC_LLCP_RAW_HEADER_SIZE,
684 					       GFP_ATOMIC);
685 
686 			if (skb_copy == NULL)
687 				continue;
688 
689 			data = skb_push(skb_copy, NFC_LLCP_RAW_HEADER_SIZE);
690 
691 			data[0] = local->dev ? local->dev->idx : 0xFF;
692 			data[1] = direction;
693 		}
694 
695 		nskb = skb_clone(skb_copy, GFP_ATOMIC);
696 		if (!nskb)
697 			continue;
698 
699 		if (sock_queue_rcv_skb(sk, nskb))
700 			kfree_skb(nskb);
701 	}
702 
703 	read_unlock(&local->raw_sockets.lock);
704 
705 	kfree_skb(skb_copy);
706 }
707 
708 static void nfc_llcp_tx_work(struct work_struct *work)
709 {
710 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
711 						    tx_work);
712 	struct sk_buff *skb;
713 	struct sock *sk;
714 	struct nfc_llcp_sock *llcp_sock;
715 
716 	skb = skb_dequeue(&local->tx_queue);
717 	if (skb != NULL) {
718 		sk = skb->sk;
719 		llcp_sock = nfc_llcp_sock(sk);
720 
721 		if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
722 			kfree_skb(skb);
723 			nfc_llcp_send_symm(local->dev);
724 		} else if (llcp_sock && !llcp_sock->remote_ready) {
725 			skb_queue_head(&local->tx_queue, skb);
726 			nfc_llcp_send_symm(local->dev);
727 		} else {
728 			struct sk_buff *copy_skb = NULL;
729 			u8 ptype = nfc_llcp_ptype(skb);
730 			int ret;
731 
732 			pr_debug("Sending pending skb\n");
733 			print_hex_dump(KERN_DEBUG, "LLCP Tx: ",
734 				       DUMP_PREFIX_OFFSET, 16, 1,
735 				       skb->data, skb->len, true);
736 
737 			if (ptype == LLCP_PDU_DISC && sk != NULL &&
738 			    sk->sk_state == LLCP_DISCONNECTING) {
739 				nfc_llcp_sock_unlink(&local->sockets, sk);
740 				sock_orphan(sk);
741 				sock_put(sk);
742 			}
743 
744 			if (ptype == LLCP_PDU_I)
745 				copy_skb = skb_copy(skb, GFP_ATOMIC);
746 
747 			__net_timestamp(skb);
748 
749 			nfc_llcp_send_to_raw_sock(local, skb,
750 						  NFC_LLCP_DIRECTION_TX);
751 
752 			ret = nfc_data_exchange(local->dev, local->target_idx,
753 						skb, nfc_llcp_recv, local);
754 
755 			if (ret) {
756 				kfree_skb(copy_skb);
757 				goto out;
758 			}
759 
760 			if (ptype == LLCP_PDU_I && copy_skb)
761 				skb_queue_tail(&llcp_sock->tx_pending_queue,
762 					       copy_skb);
763 		}
764 	} else {
765 		nfc_llcp_send_symm(local->dev);
766 	}
767 
768 out:
769 	mod_timer(&local->link_timer,
770 		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
771 }
772 
773 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
774 							  u8 ssap)
775 {
776 	struct sock *sk;
777 	struct nfc_llcp_sock *llcp_sock;
778 
779 	read_lock(&local->connecting_sockets.lock);
780 
781 	sk_for_each(sk, &local->connecting_sockets.head) {
782 		llcp_sock = nfc_llcp_sock(sk);
783 
784 		if (llcp_sock->ssap == ssap) {
785 			sock_hold(&llcp_sock->sk);
786 			goto out;
787 		}
788 	}
789 
790 	llcp_sock = NULL;
791 
792 out:
793 	read_unlock(&local->connecting_sockets.lock);
794 
795 	return llcp_sock;
796 }
797 
798 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
799 						  u8 *sn, size_t sn_len)
800 {
801 	struct nfc_llcp_sock *llcp_sock;
802 
803 	llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
804 
805 	if (llcp_sock == NULL)
806 		return NULL;
807 
808 	sock_hold(&llcp_sock->sk);
809 
810 	return llcp_sock;
811 }
812 
813 static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len)
814 {
815 	u8 *tlv = &skb->data[2], type, length;
816 	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
817 
818 	while (offset < tlv_array_len) {
819 		type = tlv[0];
820 		length = tlv[1];
821 
822 		pr_debug("type 0x%x length %d\n", type, length);
823 
824 		if (type == LLCP_TLV_SN) {
825 			*sn_len = length;
826 			return &tlv[2];
827 		}
828 
829 		offset += length + 2;
830 		tlv += length + 2;
831 	}
832 
833 	return NULL;
834 }
835 
836 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
837 			     struct sk_buff *skb)
838 {
839 	struct nfc_llcp_sock *llcp_sock;
840 	struct nfc_llcp_ui_cb *ui_cb;
841 	u8 dsap, ssap;
842 
843 	dsap = nfc_llcp_dsap(skb);
844 	ssap = nfc_llcp_ssap(skb);
845 
846 	ui_cb = nfc_llcp_ui_skb_cb(skb);
847 	ui_cb->dsap = dsap;
848 	ui_cb->ssap = ssap;
849 
850 	pr_debug("%d %d\n", dsap, ssap);
851 
852 	/* We're looking for a bound socket, not a client one */
853 	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
854 	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
855 		return;
856 
857 	/* There is no sequence with UI frames */
858 	skb_pull(skb, LLCP_HEADER_SIZE);
859 	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
860 		/*
861 		 * UI frames will be freed from the socket layer, so we
862 		 * need to keep them alive until someone receives them.
863 		 */
864 		skb_get(skb);
865 	} else {
866 		pr_err("Receive queue is full\n");
867 	}
868 
869 	nfc_llcp_sock_put(llcp_sock);
870 }
871 
872 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
873 				  struct sk_buff *skb)
874 {
875 	struct sock *new_sk, *parent;
876 	struct nfc_llcp_sock *sock, *new_sock;
877 	u8 dsap, ssap, reason;
878 
879 	dsap = nfc_llcp_dsap(skb);
880 	ssap = nfc_llcp_ssap(skb);
881 
882 	pr_debug("%d %d\n", dsap, ssap);
883 
884 	if (dsap != LLCP_SAP_SDP) {
885 		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
886 		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
887 			reason = LLCP_DM_NOBOUND;
888 			goto fail;
889 		}
890 	} else {
891 		u8 *sn;
892 		size_t sn_len;
893 
894 		sn = nfc_llcp_connect_sn(skb, &sn_len);
895 		if (sn == NULL) {
896 			reason = LLCP_DM_NOBOUND;
897 			goto fail;
898 		}
899 
900 		pr_debug("Service name length %zu\n", sn_len);
901 
902 		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
903 		if (sock == NULL) {
904 			reason = LLCP_DM_NOBOUND;
905 			goto fail;
906 		}
907 	}
908 
909 	lock_sock(&sock->sk);
910 
911 	parent = &sock->sk;
912 
913 	if (sk_acceptq_is_full(parent)) {
914 		reason = LLCP_DM_REJ;
915 		release_sock(&sock->sk);
916 		sock_put(&sock->sk);
917 		goto fail;
918 	}
919 
920 	if (sock->ssap == LLCP_SDP_UNBOUND) {
921 		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
922 
923 		pr_debug("First client, reserving %d\n", ssap);
924 
925 		if (ssap == LLCP_SAP_MAX) {
926 			reason = LLCP_DM_REJ;
927 			release_sock(&sock->sk);
928 			sock_put(&sock->sk);
929 			goto fail;
930 		}
931 
932 		sock->ssap = ssap;
933 	}
934 
935 	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC);
936 	if (new_sk == NULL) {
937 		reason = LLCP_DM_REJ;
938 		release_sock(&sock->sk);
939 		sock_put(&sock->sk);
940 		goto fail;
941 	}
942 
943 	new_sock = nfc_llcp_sock(new_sk);
944 	new_sock->dev = local->dev;
945 	new_sock->local = nfc_llcp_local_get(local);
946 	new_sock->rw = sock->rw;
947 	new_sock->miux = sock->miux;
948 	new_sock->remote_miu = local->remote_miu;
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, 0);
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(KERN_DEBUG, "LLCP Rx: ", DUMP_PREFIX_OFFSET,
1415 			       16, 1, 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_LLCP_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 		return -ENODEV;
1516 
1517 	__nfc_llcp_recv(local, skb);
1518 
1519 	return 0;
1520 }
1521 
1522 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1523 {
1524 	struct nfc_llcp_local *local;
1525 
1526 	local = nfc_llcp_find_local(dev);
1527 	if (local == NULL)
1528 		return;
1529 
1530 	local->remote_miu = LLCP_DEFAULT_MIU;
1531 	local->remote_lto = LLCP_DEFAULT_LTO;
1532 
1533 	/* Close and purge all existing sockets */
1534 	nfc_llcp_socket_release(local, true, 0);
1535 }
1536 
1537 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1538 			u8 comm_mode, u8 rf_mode)
1539 {
1540 	struct nfc_llcp_local *local;
1541 
1542 	pr_debug("rf mode %d\n", rf_mode);
1543 
1544 	local = nfc_llcp_find_local(dev);
1545 	if (local == NULL)
1546 		return;
1547 
1548 	local->target_idx = target_idx;
1549 	local->comm_mode = comm_mode;
1550 	local->rf_mode = rf_mode;
1551 
1552 	if (rf_mode == NFC_RF_INITIATOR) {
1553 		pr_debug("Queueing Tx work\n");
1554 
1555 		schedule_work(&local->tx_work);
1556 	} else {
1557 		mod_timer(&local->link_timer,
1558 			  jiffies + msecs_to_jiffies(local->remote_lto));
1559 	}
1560 }
1561 
1562 int nfc_llcp_register_device(struct nfc_dev *ndev)
1563 {
1564 	struct nfc_llcp_local *local;
1565 
1566 	local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1567 	if (local == NULL)
1568 		return -ENOMEM;
1569 
1570 	local->dev = ndev;
1571 	INIT_LIST_HEAD(&local->list);
1572 	kref_init(&local->ref);
1573 	mutex_init(&local->sdp_lock);
1574 	init_timer(&local->link_timer);
1575 	local->link_timer.data = (unsigned long) local;
1576 	local->link_timer.function = nfc_llcp_symm_timer;
1577 
1578 	skb_queue_head_init(&local->tx_queue);
1579 	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1580 
1581 	local->rx_pending = NULL;
1582 	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1583 
1584 	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1585 
1586 	rwlock_init(&local->sockets.lock);
1587 	rwlock_init(&local->connecting_sockets.lock);
1588 	rwlock_init(&local->raw_sockets.lock);
1589 
1590 	local->lto = 150; /* 1500 ms */
1591 	local->rw = LLCP_MAX_RW;
1592 	local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1593 	local->local_wks = 0x1; /* LLC Link Management */
1594 
1595 	nfc_llcp_build_gb(local);
1596 
1597 	local->remote_miu = LLCP_DEFAULT_MIU;
1598 	local->remote_lto = LLCP_DEFAULT_LTO;
1599 
1600 	mutex_init(&local->sdreq_lock);
1601 	INIT_HLIST_HEAD(&local->pending_sdreqs);
1602 	init_timer(&local->sdreq_timer);
1603 	local->sdreq_timer.data = (unsigned long) local;
1604 	local->sdreq_timer.function = nfc_llcp_sdreq_timer;
1605 	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
1606 
1607 	list_add(&local->list, &llcp_devices);
1608 
1609 	return 0;
1610 }
1611 
1612 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1613 {
1614 	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
1615 
1616 	if (local == NULL) {
1617 		pr_debug("No such device\n");
1618 		return;
1619 	}
1620 
1621 	local_cleanup(local);
1622 
1623 	nfc_llcp_local_put(local);
1624 }
1625 
1626 int __init nfc_llcp_init(void)
1627 {
1628 	INIT_LIST_HEAD(&llcp_devices);
1629 
1630 	return nfc_llcp_sock_init();
1631 }
1632 
1633 void nfc_llcp_exit(void)
1634 {
1635 	nfc_llcp_sock_exit();
1636 }
1637