xref: /linux/net/nfc/llcp_core.c (revision fba2689ee77e63b05e203b3f26079ef915e55660)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2011  Intel Corporation. All rights reserved.
4  * Copyright (C) 2014 Marvell International Ltd.
5  */
6 
7 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
8 
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/list.h>
12 #include <linux/nfc.h>
13 
14 #include "nfc.h"
15 #include "llcp.h"
16 
17 static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
18 
19 static LIST_HEAD(llcp_devices);
20 
21 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb);
22 
23 void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)
24 {
25 	write_lock(&l->lock);
26 	sk_add_node(sk, &l->head);
27 	write_unlock(&l->lock);
28 }
29 
30 void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
31 {
32 	write_lock(&l->lock);
33 	sk_del_node_init(sk);
34 	write_unlock(&l->lock);
35 }
36 
37 void nfc_llcp_socket_remote_param_init(struct nfc_llcp_sock *sock)
38 {
39 	sock->remote_rw = LLCP_DEFAULT_RW;
40 	sock->remote_miu = LLCP_MAX_MIU + 1;
41 }
42 
43 static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock)
44 {
45 	struct nfc_llcp_local *local = sock->local;
46 	struct sk_buff *s, *tmp;
47 
48 	skb_queue_purge(&sock->tx_queue);
49 	skb_queue_purge(&sock->tx_pending_queue);
50 
51 	if (local == NULL)
52 		return;
53 
54 	/* Search for local pending SKBs that are related to this socket */
55 	skb_queue_walk_safe(&local->tx_queue, s, tmp) {
56 		if (s->sk != &sock->sk)
57 			continue;
58 
59 		skb_unlink(s, &local->tx_queue);
60 		kfree_skb(s);
61 	}
62 }
63 
64 static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device,
65 				    int err)
66 {
67 	struct sock *sk;
68 	struct hlist_node *tmp;
69 	struct nfc_llcp_sock *llcp_sock;
70 
71 	skb_queue_purge(&local->tx_queue);
72 
73 	write_lock(&local->sockets.lock);
74 
75 	sk_for_each_safe(sk, tmp, &local->sockets.head) {
76 		llcp_sock = nfc_llcp_sock(sk);
77 
78 		bh_lock_sock(sk);
79 
80 		nfc_llcp_socket_purge(llcp_sock);
81 
82 		if (sk->sk_state == LLCP_CONNECTED)
83 			nfc_put_device(llcp_sock->dev);
84 
85 		if (sk->sk_state == LLCP_LISTEN) {
86 			struct nfc_llcp_sock *lsk, *n;
87 			struct sock *accept_sk;
88 
89 			list_for_each_entry_safe(lsk, n,
90 						 &llcp_sock->accept_queue,
91 						 accept_queue) {
92 				accept_sk = &lsk->sk;
93 				bh_lock_sock(accept_sk);
94 
95 				nfc_llcp_accept_unlink(accept_sk);
96 
97 				if (err)
98 					accept_sk->sk_err = err;
99 				accept_sk->sk_state = LLCP_CLOSED;
100 				accept_sk->sk_state_change(sk);
101 
102 				bh_unlock_sock(accept_sk);
103 			}
104 		}
105 
106 		if (err)
107 			sk->sk_err = err;
108 		sk->sk_state = LLCP_CLOSED;
109 		sk->sk_state_change(sk);
110 
111 		bh_unlock_sock(sk);
112 
113 		sk_del_node_init(sk);
114 	}
115 
116 	write_unlock(&local->sockets.lock);
117 
118 	/* If we still have a device, we keep the RAW sockets alive */
119 	if (device == true)
120 		return;
121 
122 	write_lock(&local->raw_sockets.lock);
123 
124 	sk_for_each_safe(sk, tmp, &local->raw_sockets.head) {
125 		llcp_sock = nfc_llcp_sock(sk);
126 
127 		bh_lock_sock(sk);
128 
129 		nfc_llcp_socket_purge(llcp_sock);
130 
131 		if (err)
132 			sk->sk_err = err;
133 		sk->sk_state = LLCP_CLOSED;
134 		sk->sk_state_change(sk);
135 
136 		bh_unlock_sock(sk);
137 
138 		sk_del_node_init(sk);
139 	}
140 
141 	write_unlock(&local->raw_sockets.lock);
142 }
143 
144 struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
145 {
146 	kref_get(&local->ref);
147 
148 	return local;
149 }
150 
151 static void local_cleanup(struct nfc_llcp_local *local)
152 {
153 	nfc_llcp_socket_release(local, false, ENXIO);
154 	del_timer_sync(&local->link_timer);
155 	skb_queue_purge(&local->tx_queue);
156 	cancel_work_sync(&local->tx_work);
157 	cancel_work_sync(&local->rx_work);
158 	cancel_work_sync(&local->timeout_work);
159 	kfree_skb(local->rx_pending);
160 	del_timer_sync(&local->sdreq_timer);
161 	cancel_work_sync(&local->sdreq_timeout_work);
162 	nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);
163 }
164 
165 static void local_release(struct kref *ref)
166 {
167 	struct nfc_llcp_local *local;
168 
169 	local = container_of(ref, struct nfc_llcp_local, ref);
170 
171 	list_del(&local->list);
172 	local_cleanup(local);
173 	kfree(local);
174 }
175 
176 int nfc_llcp_local_put(struct nfc_llcp_local *local)
177 {
178 	if (local == NULL)
179 		return 0;
180 
181 	return kref_put(&local->ref, local_release);
182 }
183 
184 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
185 					       u8 ssap, u8 dsap)
186 {
187 	struct sock *sk;
188 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
189 
190 	pr_debug("ssap dsap %d %d\n", ssap, dsap);
191 
192 	if (ssap == 0 && dsap == 0)
193 		return NULL;
194 
195 	read_lock(&local->sockets.lock);
196 
197 	llcp_sock = NULL;
198 
199 	sk_for_each(sk, &local->sockets.head) {
200 		tmp_sock = nfc_llcp_sock(sk);
201 
202 		if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
203 			llcp_sock = tmp_sock;
204 			break;
205 		}
206 	}
207 
208 	read_unlock(&local->sockets.lock);
209 
210 	if (llcp_sock == NULL)
211 		return NULL;
212 
213 	sock_hold(&llcp_sock->sk);
214 
215 	return llcp_sock;
216 }
217 
218 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
219 {
220 	sock_put(&sock->sk);
221 }
222 
223 static void nfc_llcp_timeout_work(struct work_struct *work)
224 {
225 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
226 						    timeout_work);
227 
228 	nfc_dep_link_down(local->dev);
229 }
230 
231 static void nfc_llcp_symm_timer(struct timer_list *t)
232 {
233 	struct nfc_llcp_local *local = from_timer(local, t, link_timer);
234 
235 	pr_err("SYMM timeout\n");
236 
237 	schedule_work(&local->timeout_work);
238 }
239 
240 static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
241 {
242 	unsigned long time;
243 	HLIST_HEAD(nl_sdres_list);
244 	struct hlist_node *n;
245 	struct nfc_llcp_sdp_tlv *sdp;
246 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
247 						    sdreq_timeout_work);
248 
249 	mutex_lock(&local->sdreq_lock);
250 
251 	time = jiffies - msecs_to_jiffies(3 * local->remote_lto);
252 
253 	hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) {
254 		if (time_after(sdp->time, time))
255 			continue;
256 
257 		sdp->sap = LLCP_SDP_UNBOUND;
258 
259 		hlist_del(&sdp->node);
260 
261 		hlist_add_head(&sdp->node, &nl_sdres_list);
262 	}
263 
264 	if (!hlist_empty(&local->pending_sdreqs))
265 		mod_timer(&local->sdreq_timer,
266 			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
267 
268 	mutex_unlock(&local->sdreq_lock);
269 
270 	if (!hlist_empty(&nl_sdres_list))
271 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
272 }
273 
274 static void nfc_llcp_sdreq_timer(struct timer_list *t)
275 {
276 	struct nfc_llcp_local *local = from_timer(local, t, sdreq_timer);
277 
278 	schedule_work(&local->sdreq_timeout_work);
279 }
280 
281 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
282 {
283 	struct nfc_llcp_local *local;
284 
285 	list_for_each_entry(local, &llcp_devices, list)
286 		if (local->dev == dev)
287 			return local;
288 
289 	pr_debug("No device found\n");
290 
291 	return NULL;
292 }
293 
294 static char *wks[] = {
295 	NULL,
296 	NULL, /* SDP */
297 	"urn:nfc:sn:ip",
298 	"urn:nfc:sn:obex",
299 	"urn:nfc:sn:snep",
300 };
301 
302 static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len)
303 {
304 	int sap, num_wks;
305 
306 	pr_debug("%s\n", service_name);
307 
308 	if (service_name == NULL)
309 		return -EINVAL;
310 
311 	num_wks = ARRAY_SIZE(wks);
312 
313 	for (sap = 0; sap < num_wks; sap++) {
314 		if (wks[sap] == NULL)
315 			continue;
316 
317 		if (strncmp(wks[sap], service_name, service_name_len) == 0)
318 			return sap;
319 	}
320 
321 	return -EINVAL;
322 }
323 
324 static
325 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
326 					    const u8 *sn, size_t sn_len)
327 {
328 	struct sock *sk;
329 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
330 
331 	pr_debug("sn %zd %p\n", sn_len, sn);
332 
333 	if (sn == NULL || sn_len == 0)
334 		return NULL;
335 
336 	read_lock(&local->sockets.lock);
337 
338 	llcp_sock = NULL;
339 
340 	sk_for_each(sk, &local->sockets.head) {
341 		tmp_sock = nfc_llcp_sock(sk);
342 
343 		pr_debug("llcp sock %p\n", tmp_sock);
344 
345 		if (tmp_sock->sk.sk_type == SOCK_STREAM &&
346 		    tmp_sock->sk.sk_state != LLCP_LISTEN)
347 			continue;
348 
349 		if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
350 		    tmp_sock->sk.sk_state != LLCP_BOUND)
351 			continue;
352 
353 		if (tmp_sock->service_name == NULL ||
354 		    tmp_sock->service_name_len == 0)
355 			continue;
356 
357 		if (tmp_sock->service_name_len != sn_len)
358 			continue;
359 
360 		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
361 			llcp_sock = tmp_sock;
362 			break;
363 		}
364 	}
365 
366 	read_unlock(&local->sockets.lock);
367 
368 	pr_debug("Found llcp sock %p\n", llcp_sock);
369 
370 	return llcp_sock;
371 }
372 
373 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
374 			 struct nfc_llcp_sock *sock)
375 {
376 	mutex_lock(&local->sdp_lock);
377 
378 	if (sock->service_name != NULL && sock->service_name_len > 0) {
379 		int ssap = nfc_llcp_wks_sap(sock->service_name,
380 					    sock->service_name_len);
381 
382 		if (ssap > 0) {
383 			pr_debug("WKS %d\n", ssap);
384 
385 			/* This is a WKS, let's check if it's free */
386 			if (test_bit(ssap, &local->local_wks)) {
387 				mutex_unlock(&local->sdp_lock);
388 
389 				return LLCP_SAP_MAX;
390 			}
391 
392 			set_bit(ssap, &local->local_wks);
393 			mutex_unlock(&local->sdp_lock);
394 
395 			return ssap;
396 		}
397 
398 		/*
399 		 * Check if there already is a non WKS socket bound
400 		 * to this service name.
401 		 */
402 		if (nfc_llcp_sock_from_sn(local, sock->service_name,
403 					  sock->service_name_len) != NULL) {
404 			mutex_unlock(&local->sdp_lock);
405 
406 			return LLCP_SAP_MAX;
407 		}
408 
409 		mutex_unlock(&local->sdp_lock);
410 
411 		return LLCP_SDP_UNBOUND;
412 
413 	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
414 		if (!test_bit(sock->ssap, &local->local_wks)) {
415 			set_bit(sock->ssap, &local->local_wks);
416 			mutex_unlock(&local->sdp_lock);
417 
418 			return sock->ssap;
419 		}
420 	}
421 
422 	mutex_unlock(&local->sdp_lock);
423 
424 	return LLCP_SAP_MAX;
425 }
426 
427 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
428 {
429 	u8 local_ssap;
430 
431 	mutex_lock(&local->sdp_lock);
432 
433 	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
434 	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
435 		mutex_unlock(&local->sdp_lock);
436 		return LLCP_SAP_MAX;
437 	}
438 
439 	set_bit(local_ssap, &local->local_sap);
440 
441 	mutex_unlock(&local->sdp_lock);
442 
443 	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
444 }
445 
446 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
447 {
448 	u8 local_ssap;
449 	unsigned long *sdp;
450 
451 	if (ssap < LLCP_WKS_NUM_SAP) {
452 		local_ssap = ssap;
453 		sdp = &local->local_wks;
454 	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
455 		atomic_t *client_cnt;
456 
457 		local_ssap = ssap - LLCP_WKS_NUM_SAP;
458 		sdp = &local->local_sdp;
459 		client_cnt = &local->local_sdp_cnt[local_ssap];
460 
461 		pr_debug("%d clients\n", atomic_read(client_cnt));
462 
463 		mutex_lock(&local->sdp_lock);
464 
465 		if (atomic_dec_and_test(client_cnt)) {
466 			struct nfc_llcp_sock *l_sock;
467 
468 			pr_debug("No more clients for SAP %d\n", ssap);
469 
470 			clear_bit(local_ssap, sdp);
471 
472 			/* Find the listening sock and set it back to UNBOUND */
473 			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
474 			if (l_sock) {
475 				l_sock->ssap = LLCP_SDP_UNBOUND;
476 				nfc_llcp_sock_put(l_sock);
477 			}
478 		}
479 
480 		mutex_unlock(&local->sdp_lock);
481 
482 		return;
483 	} else if (ssap < LLCP_MAX_SAP) {
484 		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
485 		sdp = &local->local_sap;
486 	} else {
487 		return;
488 	}
489 
490 	mutex_lock(&local->sdp_lock);
491 
492 	clear_bit(local_ssap, sdp);
493 
494 	mutex_unlock(&local->sdp_lock);
495 }
496 
497 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
498 {
499 	u8 ssap;
500 
501 	mutex_lock(&local->sdp_lock);
502 
503 	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
504 	if (ssap == LLCP_SDP_NUM_SAP) {
505 		mutex_unlock(&local->sdp_lock);
506 
507 		return LLCP_SAP_MAX;
508 	}
509 
510 	pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
511 
512 	set_bit(ssap, &local->local_sdp);
513 
514 	mutex_unlock(&local->sdp_lock);
515 
516 	return LLCP_WKS_NUM_SAP + ssap;
517 }
518 
519 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
520 {
521 	u8 *gb_cur, version, version_length;
522 	u8 lto_length, wks_length, miux_length;
523 	const u8 *version_tlv = NULL, *lto_tlv = NULL,
524 	   *wks_tlv = NULL, *miux_tlv = NULL;
525 	__be16 wks = cpu_to_be16(local->local_wks);
526 	u8 gb_len = 0;
527 	int ret = 0;
528 
529 	version = LLCP_VERSION_11;
530 	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
531 					 1, &version_length);
532 	if (!version_tlv) {
533 		ret = -ENOMEM;
534 		goto out;
535 	}
536 	gb_len += version_length;
537 
538 	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
539 	if (!lto_tlv) {
540 		ret = -ENOMEM;
541 		goto out;
542 	}
543 	gb_len += lto_length;
544 
545 	pr_debug("Local wks 0x%lx\n", local->local_wks);
546 	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
547 	if (!wks_tlv) {
548 		ret = -ENOMEM;
549 		goto out;
550 	}
551 	gb_len += wks_length;
552 
553 	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
554 				      &miux_length);
555 	if (!miux_tlv) {
556 		ret = -ENOMEM;
557 		goto out;
558 	}
559 	gb_len += miux_length;
560 
561 	gb_len += ARRAY_SIZE(llcp_magic);
562 
563 	if (gb_len > NFC_MAX_GT_LEN) {
564 		ret = -EINVAL;
565 		goto out;
566 	}
567 
568 	gb_cur = local->gb;
569 
570 	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
571 	gb_cur += ARRAY_SIZE(llcp_magic);
572 
573 	memcpy(gb_cur, version_tlv, version_length);
574 	gb_cur += version_length;
575 
576 	memcpy(gb_cur, lto_tlv, lto_length);
577 	gb_cur += lto_length;
578 
579 	memcpy(gb_cur, wks_tlv, wks_length);
580 	gb_cur += wks_length;
581 
582 	memcpy(gb_cur, miux_tlv, miux_length);
583 	gb_cur += miux_length;
584 
585 	local->gb_len = gb_len;
586 
587 out:
588 	kfree(version_tlv);
589 	kfree(lto_tlv);
590 	kfree(wks_tlv);
591 	kfree(miux_tlv);
592 
593 	return ret;
594 }
595 
596 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
597 {
598 	struct nfc_llcp_local *local;
599 
600 	local = nfc_llcp_find_local(dev);
601 	if (local == NULL) {
602 		*general_bytes_len = 0;
603 		return NULL;
604 	}
605 
606 	nfc_llcp_build_gb(local);
607 
608 	*general_bytes_len = local->gb_len;
609 
610 	return local->gb;
611 }
612 
613 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, const u8 *gb, u8 gb_len)
614 {
615 	struct nfc_llcp_local *local;
616 
617 	if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
618 		return -EINVAL;
619 
620 	local = nfc_llcp_find_local(dev);
621 	if (local == NULL) {
622 		pr_err("No LLCP device\n");
623 		return -ENODEV;
624 	}
625 
626 	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
627 	memcpy(local->remote_gb, gb, gb_len);
628 	local->remote_gb_len = gb_len;
629 
630 	if (memcmp(local->remote_gb, llcp_magic, 3)) {
631 		pr_err("MAC does not support LLCP\n");
632 		return -EINVAL;
633 	}
634 
635 	return nfc_llcp_parse_gb_tlv(local,
636 				     &local->remote_gb[3],
637 				     local->remote_gb_len - 3);
638 }
639 
640 static u8 nfc_llcp_dsap(const struct sk_buff *pdu)
641 {
642 	return (pdu->data[0] & 0xfc) >> 2;
643 }
644 
645 static u8 nfc_llcp_ptype(const struct sk_buff *pdu)
646 {
647 	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
648 }
649 
650 static u8 nfc_llcp_ssap(const struct sk_buff *pdu)
651 {
652 	return pdu->data[1] & 0x3f;
653 }
654 
655 static u8 nfc_llcp_ns(const struct sk_buff *pdu)
656 {
657 	return pdu->data[2] >> 4;
658 }
659 
660 static u8 nfc_llcp_nr(const struct sk_buff *pdu)
661 {
662 	return pdu->data[2] & 0xf;
663 }
664 
665 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
666 {
667 	pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
668 	sock->send_n = (sock->send_n + 1) % 16;
669 	sock->recv_ack_n = (sock->recv_n - 1) % 16;
670 }
671 
672 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
673 			       struct sk_buff *skb, u8 direction)
674 {
675 	struct sk_buff *skb_copy = NULL, *nskb;
676 	struct sock *sk;
677 	u8 *data;
678 
679 	read_lock(&local->raw_sockets.lock);
680 
681 	sk_for_each(sk, &local->raw_sockets.head) {
682 		if (sk->sk_state != LLCP_BOUND)
683 			continue;
684 
685 		if (skb_copy == NULL) {
686 			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
687 						      GFP_ATOMIC, true);
688 
689 			if (skb_copy == NULL)
690 				continue;
691 
692 			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
693 
694 			data[0] = local->dev ? local->dev->idx : 0xFF;
695 			data[1] = direction & 0x01;
696 			data[1] |= (RAW_PAYLOAD_LLCP << 1);
697 		}
698 
699 		nskb = skb_clone(skb_copy, GFP_ATOMIC);
700 		if (!nskb)
701 			continue;
702 
703 		if (sock_queue_rcv_skb(sk, nskb))
704 			kfree_skb(nskb);
705 	}
706 
707 	read_unlock(&local->raw_sockets.lock);
708 
709 	kfree_skb(skb_copy);
710 }
711 
712 static void nfc_llcp_tx_work(struct work_struct *work)
713 {
714 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
715 						    tx_work);
716 	struct sk_buff *skb;
717 	struct sock *sk;
718 	struct nfc_llcp_sock *llcp_sock;
719 
720 	skb = skb_dequeue(&local->tx_queue);
721 	if (skb != NULL) {
722 		sk = skb->sk;
723 		llcp_sock = nfc_llcp_sock(sk);
724 
725 		if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
726 			kfree_skb(skb);
727 			nfc_llcp_send_symm(local->dev);
728 		} else if (llcp_sock && !llcp_sock->remote_ready) {
729 			skb_queue_head(&local->tx_queue, skb);
730 			nfc_llcp_send_symm(local->dev);
731 		} else {
732 			struct sk_buff *copy_skb = NULL;
733 			u8 ptype = nfc_llcp_ptype(skb);
734 			int ret;
735 
736 			pr_debug("Sending pending skb\n");
737 			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
738 					     16, 1, skb->data, skb->len, true);
739 
740 			if (ptype == LLCP_PDU_I)
741 				copy_skb = skb_copy(skb, GFP_ATOMIC);
742 
743 			__net_timestamp(skb);
744 
745 			nfc_llcp_send_to_raw_sock(local, skb,
746 						  NFC_DIRECTION_TX);
747 
748 			ret = nfc_data_exchange(local->dev, local->target_idx,
749 						skb, nfc_llcp_recv, local);
750 
751 			if (ret) {
752 				kfree_skb(copy_skb);
753 				goto out;
754 			}
755 
756 			if (ptype == LLCP_PDU_I && copy_skb)
757 				skb_queue_tail(&llcp_sock->tx_pending_queue,
758 					       copy_skb);
759 		}
760 	} else {
761 		nfc_llcp_send_symm(local->dev);
762 	}
763 
764 out:
765 	mod_timer(&local->link_timer,
766 		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
767 }
768 
769 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
770 							  u8 ssap)
771 {
772 	struct sock *sk;
773 	struct nfc_llcp_sock *llcp_sock;
774 
775 	read_lock(&local->connecting_sockets.lock);
776 
777 	sk_for_each(sk, &local->connecting_sockets.head) {
778 		llcp_sock = nfc_llcp_sock(sk);
779 
780 		if (llcp_sock->ssap == ssap) {
781 			sock_hold(&llcp_sock->sk);
782 			goto out;
783 		}
784 	}
785 
786 	llcp_sock = NULL;
787 
788 out:
789 	read_unlock(&local->connecting_sockets.lock);
790 
791 	return llcp_sock;
792 }
793 
794 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
795 						  const u8 *sn, size_t sn_len)
796 {
797 	struct nfc_llcp_sock *llcp_sock;
798 
799 	llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
800 
801 	if (llcp_sock == NULL)
802 		return NULL;
803 
804 	sock_hold(&llcp_sock->sk);
805 
806 	return llcp_sock;
807 }
808 
809 static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
810 {
811 	u8 type, length;
812 	const u8 *tlv = &skb->data[2];
813 	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
814 
815 	while (offset < tlv_array_len) {
816 		type = tlv[0];
817 		length = tlv[1];
818 
819 		pr_debug("type 0x%x length %d\n", type, length);
820 
821 		if (type == LLCP_TLV_SN) {
822 			*sn_len = length;
823 			return &tlv[2];
824 		}
825 
826 		offset += length + 2;
827 		tlv += length + 2;
828 	}
829 
830 	return NULL;
831 }
832 
833 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
834 			     struct sk_buff *skb)
835 {
836 	struct nfc_llcp_sock *llcp_sock;
837 	struct nfc_llcp_ui_cb *ui_cb;
838 	u8 dsap, ssap;
839 
840 	dsap = nfc_llcp_dsap(skb);
841 	ssap = nfc_llcp_ssap(skb);
842 
843 	ui_cb = nfc_llcp_ui_skb_cb(skb);
844 	ui_cb->dsap = dsap;
845 	ui_cb->ssap = ssap;
846 
847 	pr_debug("%d %d\n", dsap, ssap);
848 
849 	/* We're looking for a bound socket, not a client one */
850 	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
851 	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
852 		return;
853 
854 	/* There is no sequence with UI frames */
855 	skb_pull(skb, LLCP_HEADER_SIZE);
856 	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
857 		/*
858 		 * UI frames will be freed from the socket layer, so we
859 		 * need to keep them alive until someone receives them.
860 		 */
861 		skb_get(skb);
862 	} else {
863 		pr_err("Receive queue is full\n");
864 	}
865 
866 	nfc_llcp_sock_put(llcp_sock);
867 }
868 
869 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
870 				  const struct sk_buff *skb)
871 {
872 	struct sock *new_sk, *parent;
873 	struct nfc_llcp_sock *sock, *new_sock;
874 	u8 dsap, ssap, reason;
875 
876 	dsap = nfc_llcp_dsap(skb);
877 	ssap = nfc_llcp_ssap(skb);
878 
879 	pr_debug("%d %d\n", dsap, ssap);
880 
881 	if (dsap != LLCP_SAP_SDP) {
882 		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
883 		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
884 			reason = LLCP_DM_NOBOUND;
885 			goto fail;
886 		}
887 	} else {
888 		const u8 *sn;
889 		size_t sn_len;
890 
891 		sn = nfc_llcp_connect_sn(skb, &sn_len);
892 		if (sn == NULL) {
893 			reason = LLCP_DM_NOBOUND;
894 			goto fail;
895 		}
896 
897 		pr_debug("Service name length %zu\n", sn_len);
898 
899 		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
900 		if (sock == NULL) {
901 			reason = LLCP_DM_NOBOUND;
902 			goto fail;
903 		}
904 	}
905 
906 	lock_sock(&sock->sk);
907 
908 	parent = &sock->sk;
909 
910 	if (sk_acceptq_is_full(parent)) {
911 		reason = LLCP_DM_REJ;
912 		release_sock(&sock->sk);
913 		sock_put(&sock->sk);
914 		goto fail;
915 	}
916 
917 	if (sock->ssap == LLCP_SDP_UNBOUND) {
918 		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
919 
920 		pr_debug("First client, reserving %d\n", ssap);
921 
922 		if (ssap == LLCP_SAP_MAX) {
923 			reason = LLCP_DM_REJ;
924 			release_sock(&sock->sk);
925 			sock_put(&sock->sk);
926 			goto fail;
927 		}
928 
929 		sock->ssap = ssap;
930 	}
931 
932 	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
933 	if (new_sk == NULL) {
934 		reason = LLCP_DM_REJ;
935 		release_sock(&sock->sk);
936 		sock_put(&sock->sk);
937 		goto fail;
938 	}
939 
940 	new_sock = nfc_llcp_sock(new_sk);
941 	new_sock->dev = local->dev;
942 	new_sock->local = nfc_llcp_local_get(local);
943 	new_sock->rw = sock->rw;
944 	new_sock->miux = sock->miux;
945 	new_sock->nfc_protocol = sock->nfc_protocol;
946 	new_sock->dsap = ssap;
947 	new_sock->target_idx = local->target_idx;
948 	new_sock->parent = parent;
949 	new_sock->ssap = sock->ssap;
950 	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
951 		atomic_t *client_count;
952 
953 		pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
954 
955 		client_count =
956 			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
957 
958 		atomic_inc(client_count);
959 		new_sock->reserved_ssap = sock->ssap;
960 	}
961 
962 	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
963 				      skb->len - LLCP_HEADER_SIZE);
964 
965 	pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
966 
967 	nfc_llcp_sock_link(&local->sockets, new_sk);
968 
969 	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
970 
971 	nfc_get_device(local->dev->idx);
972 
973 	new_sk->sk_state = LLCP_CONNECTED;
974 
975 	/* Wake the listening processes */
976 	parent->sk_data_ready(parent);
977 
978 	/* Send CC */
979 	nfc_llcp_send_cc(new_sock);
980 
981 	release_sock(&sock->sk);
982 	sock_put(&sock->sk);
983 
984 	return;
985 
986 fail:
987 	/* Send DM */
988 	nfc_llcp_send_dm(local, dsap, ssap, reason);
989 }
990 
991 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
992 {
993 	int nr_frames = 0;
994 	struct nfc_llcp_local *local = sock->local;
995 
996 	pr_debug("Remote ready %d tx queue len %d remote rw %d",
997 		 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
998 		 sock->remote_rw);
999 
1000 	/* Try to queue some I frames for transmission */
1001 	while (sock->remote_ready &&
1002 	       skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {
1003 		struct sk_buff *pdu;
1004 
1005 		pdu = skb_dequeue(&sock->tx_queue);
1006 		if (pdu == NULL)
1007 			break;
1008 
1009 		/* Update N(S)/N(R) */
1010 		nfc_llcp_set_nrns(sock, pdu);
1011 
1012 		skb_queue_tail(&local->tx_queue, pdu);
1013 		nr_frames++;
1014 	}
1015 
1016 	return nr_frames;
1017 }
1018 
1019 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
1020 			       struct sk_buff *skb)
1021 {
1022 	struct nfc_llcp_sock *llcp_sock;
1023 	struct sock *sk;
1024 	u8 dsap, ssap, ptype, ns, nr;
1025 
1026 	ptype = nfc_llcp_ptype(skb);
1027 	dsap = nfc_llcp_dsap(skb);
1028 	ssap = nfc_llcp_ssap(skb);
1029 	ns = nfc_llcp_ns(skb);
1030 	nr = nfc_llcp_nr(skb);
1031 
1032 	pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
1033 
1034 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1035 	if (llcp_sock == NULL) {
1036 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1037 		return;
1038 	}
1039 
1040 	sk = &llcp_sock->sk;
1041 	lock_sock(sk);
1042 	if (sk->sk_state == LLCP_CLOSED) {
1043 		release_sock(sk);
1044 		nfc_llcp_sock_put(llcp_sock);
1045 	}
1046 
1047 	/* Pass the payload upstream */
1048 	if (ptype == LLCP_PDU_I) {
1049 		pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
1050 
1051 		if (ns == llcp_sock->recv_n)
1052 			llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
1053 		else
1054 			pr_err("Received out of sequence I PDU\n");
1055 
1056 		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
1057 		if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
1058 			/*
1059 			 * I frames will be freed from the socket layer, so we
1060 			 * need to keep them alive until someone receives them.
1061 			 */
1062 			skb_get(skb);
1063 		} else {
1064 			pr_err("Receive queue is full\n");
1065 		}
1066 	}
1067 
1068 	/* Remove skbs from the pending queue */
1069 	if (llcp_sock->send_ack_n != nr) {
1070 		struct sk_buff *s, *tmp;
1071 		u8 n;
1072 
1073 		llcp_sock->send_ack_n = nr;
1074 
1075 		/* Remove and free all skbs until ns == nr */
1076 		skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
1077 			n = nfc_llcp_ns(s);
1078 
1079 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1080 			kfree_skb(s);
1081 
1082 			if (n == nr)
1083 				break;
1084 		}
1085 
1086 		/* Re-queue the remaining skbs for transmission */
1087 		skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1088 					    s, tmp) {
1089 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1090 			skb_queue_head(&local->tx_queue, s);
1091 		}
1092 	}
1093 
1094 	if (ptype == LLCP_PDU_RR)
1095 		llcp_sock->remote_ready = true;
1096 	else if (ptype == LLCP_PDU_RNR)
1097 		llcp_sock->remote_ready = false;
1098 
1099 	if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1100 		nfc_llcp_send_rr(llcp_sock);
1101 
1102 	release_sock(sk);
1103 	nfc_llcp_sock_put(llcp_sock);
1104 }
1105 
1106 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1107 			       const struct sk_buff *skb)
1108 {
1109 	struct nfc_llcp_sock *llcp_sock;
1110 	struct sock *sk;
1111 	u8 dsap, ssap;
1112 
1113 	dsap = nfc_llcp_dsap(skb);
1114 	ssap = nfc_llcp_ssap(skb);
1115 
1116 	if ((dsap == 0) && (ssap == 0)) {
1117 		pr_debug("Connection termination");
1118 		nfc_dep_link_down(local->dev);
1119 		return;
1120 	}
1121 
1122 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1123 	if (llcp_sock == NULL) {
1124 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1125 		return;
1126 	}
1127 
1128 	sk = &llcp_sock->sk;
1129 	lock_sock(sk);
1130 
1131 	nfc_llcp_socket_purge(llcp_sock);
1132 
1133 	if (sk->sk_state == LLCP_CLOSED) {
1134 		release_sock(sk);
1135 		nfc_llcp_sock_put(llcp_sock);
1136 	}
1137 
1138 	if (sk->sk_state == LLCP_CONNECTED) {
1139 		nfc_put_device(local->dev);
1140 		sk->sk_state = LLCP_CLOSED;
1141 		sk->sk_state_change(sk);
1142 	}
1143 
1144 	nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1145 
1146 	release_sock(sk);
1147 	nfc_llcp_sock_put(llcp_sock);
1148 }
1149 
1150 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local,
1151 			     const struct sk_buff *skb)
1152 {
1153 	struct nfc_llcp_sock *llcp_sock;
1154 	struct sock *sk;
1155 	u8 dsap, ssap;
1156 
1157 	dsap = nfc_llcp_dsap(skb);
1158 	ssap = nfc_llcp_ssap(skb);
1159 
1160 	llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1161 	if (llcp_sock == NULL) {
1162 		pr_err("Invalid CC\n");
1163 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1164 
1165 		return;
1166 	}
1167 
1168 	sk = &llcp_sock->sk;
1169 
1170 	/* Unlink from connecting and link to the client array */
1171 	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1172 	nfc_llcp_sock_link(&local->sockets, sk);
1173 	llcp_sock->dsap = ssap;
1174 
1175 	nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1176 				      skb->len - LLCP_HEADER_SIZE);
1177 
1178 	sk->sk_state = LLCP_CONNECTED;
1179 	sk->sk_state_change(sk);
1180 
1181 	nfc_llcp_sock_put(llcp_sock);
1182 }
1183 
1184 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local,
1185 			     const struct sk_buff *skb)
1186 {
1187 	struct nfc_llcp_sock *llcp_sock;
1188 	struct sock *sk;
1189 	u8 dsap, ssap, reason;
1190 
1191 	dsap = nfc_llcp_dsap(skb);
1192 	ssap = nfc_llcp_ssap(skb);
1193 	reason = skb->data[2];
1194 
1195 	pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1196 
1197 	switch (reason) {
1198 	case LLCP_DM_NOBOUND:
1199 	case LLCP_DM_REJ:
1200 		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1201 		break;
1202 
1203 	default:
1204 		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1205 		break;
1206 	}
1207 
1208 	if (llcp_sock == NULL) {
1209 		pr_debug("Already closed\n");
1210 		return;
1211 	}
1212 
1213 	sk = &llcp_sock->sk;
1214 
1215 	sk->sk_err = ENXIO;
1216 	sk->sk_state = LLCP_CLOSED;
1217 	sk->sk_state_change(sk);
1218 
1219 	nfc_llcp_sock_put(llcp_sock);
1220 }
1221 
1222 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1223 			      const struct sk_buff *skb)
1224 {
1225 	struct nfc_llcp_sock *llcp_sock;
1226 	u8 dsap, ssap, type, length, tid, sap;
1227 	const u8 *tlv;
1228 	u16 tlv_len, offset;
1229 	const char *service_name;
1230 	size_t service_name_len;
1231 	struct nfc_llcp_sdp_tlv *sdp;
1232 	HLIST_HEAD(llc_sdres_list);
1233 	size_t sdres_tlvs_len;
1234 	HLIST_HEAD(nl_sdres_list);
1235 
1236 	dsap = nfc_llcp_dsap(skb);
1237 	ssap = nfc_llcp_ssap(skb);
1238 
1239 	pr_debug("%d %d\n", dsap, ssap);
1240 
1241 	if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1242 		pr_err("Wrong SNL SAP\n");
1243 		return;
1244 	}
1245 
1246 	tlv = &skb->data[LLCP_HEADER_SIZE];
1247 	tlv_len = skb->len - LLCP_HEADER_SIZE;
1248 	offset = 0;
1249 	sdres_tlvs_len = 0;
1250 
1251 	while (offset < tlv_len) {
1252 		type = tlv[0];
1253 		length = tlv[1];
1254 
1255 		switch (type) {
1256 		case LLCP_TLV_SDREQ:
1257 			tid = tlv[2];
1258 			service_name = (char *) &tlv[3];
1259 			service_name_len = length - 1;
1260 
1261 			pr_debug("Looking for %.16s\n", service_name);
1262 
1263 			if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1264 			    !strncmp(service_name, "urn:nfc:sn:sdp",
1265 				     service_name_len)) {
1266 				sap = 1;
1267 				goto add_snl;
1268 			}
1269 
1270 			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1271 							  service_name_len);
1272 			if (!llcp_sock) {
1273 				sap = 0;
1274 				goto add_snl;
1275 			}
1276 
1277 			/*
1278 			 * We found a socket but its ssap has not been reserved
1279 			 * yet. We need to assign it for good and send a reply.
1280 			 * The ssap will be freed when the socket is closed.
1281 			 */
1282 			if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1283 				atomic_t *client_count;
1284 
1285 				sap = nfc_llcp_reserve_sdp_ssap(local);
1286 
1287 				pr_debug("Reserving %d\n", sap);
1288 
1289 				if (sap == LLCP_SAP_MAX) {
1290 					sap = 0;
1291 					goto add_snl;
1292 				}
1293 
1294 				client_count =
1295 					&local->local_sdp_cnt[sap -
1296 							      LLCP_WKS_NUM_SAP];
1297 
1298 				atomic_inc(client_count);
1299 
1300 				llcp_sock->ssap = sap;
1301 				llcp_sock->reserved_ssap = sap;
1302 			} else {
1303 				sap = llcp_sock->ssap;
1304 			}
1305 
1306 			pr_debug("%p %d\n", llcp_sock, sap);
1307 
1308 add_snl:
1309 			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
1310 			if (sdp == NULL)
1311 				goto exit;
1312 
1313 			sdres_tlvs_len += sdp->tlv_len;
1314 			hlist_add_head(&sdp->node, &llc_sdres_list);
1315 			break;
1316 
1317 		case LLCP_TLV_SDRES:
1318 			mutex_lock(&local->sdreq_lock);
1319 
1320 			pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]);
1321 
1322 			hlist_for_each_entry(sdp, &local->pending_sdreqs, node) {
1323 				if (sdp->tid != tlv[2])
1324 					continue;
1325 
1326 				sdp->sap = tlv[3];
1327 
1328 				pr_debug("Found: uri=%s, sap=%d\n",
1329 					 sdp->uri, sdp->sap);
1330 
1331 				hlist_del(&sdp->node);
1332 
1333 				hlist_add_head(&sdp->node, &nl_sdres_list);
1334 
1335 				break;
1336 			}
1337 
1338 			mutex_unlock(&local->sdreq_lock);
1339 			break;
1340 
1341 		default:
1342 			pr_err("Invalid SNL tlv value 0x%x\n", type);
1343 			break;
1344 		}
1345 
1346 		offset += length + 2;
1347 		tlv += length + 2;
1348 	}
1349 
1350 exit:
1351 	if (!hlist_empty(&nl_sdres_list))
1352 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
1353 
1354 	if (!hlist_empty(&llc_sdres_list))
1355 		nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);
1356 }
1357 
1358 static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
1359 {
1360 	u8 ptype;
1361 	u16 pdu_len;
1362 	struct sk_buff *new_skb;
1363 
1364 	if (skb->len <= LLCP_HEADER_SIZE) {
1365 		pr_err("Malformed AGF PDU\n");
1366 		return;
1367 	}
1368 
1369 	skb_pull(skb, LLCP_HEADER_SIZE);
1370 
1371 	while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) {
1372 		pdu_len = skb->data[0] << 8 | skb->data[1];
1373 
1374 		skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE);
1375 
1376 		if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) {
1377 			pr_err("Malformed AGF PDU\n");
1378 			return;
1379 		}
1380 
1381 		ptype = nfc_llcp_ptype(skb);
1382 
1383 		if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF)
1384 			goto next;
1385 
1386 		new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
1387 		if (new_skb == NULL) {
1388 			pr_err("Could not allocate PDU\n");
1389 			return;
1390 		}
1391 
1392 		skb_put_data(new_skb, skb->data, pdu_len);
1393 
1394 		nfc_llcp_rx_skb(local, new_skb);
1395 
1396 		kfree_skb(new_skb);
1397 next:
1398 		skb_pull(skb, pdu_len);
1399 	}
1400 }
1401 
1402 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
1403 {
1404 	u8 dsap, ssap, ptype;
1405 
1406 	ptype = nfc_llcp_ptype(skb);
1407 	dsap = nfc_llcp_dsap(skb);
1408 	ssap = nfc_llcp_ssap(skb);
1409 
1410 	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1411 
1412 	if (ptype != LLCP_PDU_SYMM)
1413 		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
1414 				     skb->data, skb->len, true);
1415 
1416 	switch (ptype) {
1417 	case LLCP_PDU_SYMM:
1418 		pr_debug("SYMM\n");
1419 		break;
1420 
1421 	case LLCP_PDU_UI:
1422 		pr_debug("UI\n");
1423 		nfc_llcp_recv_ui(local, skb);
1424 		break;
1425 
1426 	case LLCP_PDU_CONNECT:
1427 		pr_debug("CONNECT\n");
1428 		nfc_llcp_recv_connect(local, skb);
1429 		break;
1430 
1431 	case LLCP_PDU_DISC:
1432 		pr_debug("DISC\n");
1433 		nfc_llcp_recv_disc(local, skb);
1434 		break;
1435 
1436 	case LLCP_PDU_CC:
1437 		pr_debug("CC\n");
1438 		nfc_llcp_recv_cc(local, skb);
1439 		break;
1440 
1441 	case LLCP_PDU_DM:
1442 		pr_debug("DM\n");
1443 		nfc_llcp_recv_dm(local, skb);
1444 		break;
1445 
1446 	case LLCP_PDU_SNL:
1447 		pr_debug("SNL\n");
1448 		nfc_llcp_recv_snl(local, skb);
1449 		break;
1450 
1451 	case LLCP_PDU_I:
1452 	case LLCP_PDU_RR:
1453 	case LLCP_PDU_RNR:
1454 		pr_debug("I frame\n");
1455 		nfc_llcp_recv_hdlc(local, skb);
1456 		break;
1457 
1458 	case LLCP_PDU_AGF:
1459 		pr_debug("AGF frame\n");
1460 		nfc_llcp_recv_agf(local, skb);
1461 		break;
1462 	}
1463 }
1464 
1465 static void nfc_llcp_rx_work(struct work_struct *work)
1466 {
1467 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1468 						    rx_work);
1469 	struct sk_buff *skb;
1470 
1471 	skb = local->rx_pending;
1472 	if (skb == NULL) {
1473 		pr_debug("No pending SKB\n");
1474 		return;
1475 	}
1476 
1477 	__net_timestamp(skb);
1478 
1479 	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);
1480 
1481 	nfc_llcp_rx_skb(local, skb);
1482 
1483 	schedule_work(&local->tx_work);
1484 	kfree_skb(local->rx_pending);
1485 	local->rx_pending = NULL;
1486 }
1487 
1488 static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
1489 {
1490 	local->rx_pending = skb;
1491 	del_timer(&local->link_timer);
1492 	schedule_work(&local->rx_work);
1493 }
1494 
1495 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1496 {
1497 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1498 
1499 	if (err < 0) {
1500 		pr_err("LLCP PDU receive err %d\n", err);
1501 		return;
1502 	}
1503 
1504 	__nfc_llcp_recv(local, skb);
1505 }
1506 
1507 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1508 {
1509 	struct nfc_llcp_local *local;
1510 
1511 	local = nfc_llcp_find_local(dev);
1512 	if (local == NULL) {
1513 		kfree_skb(skb);
1514 		return -ENODEV;
1515 	}
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 	timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0);
1575 
1576 	skb_queue_head_init(&local->tx_queue);
1577 	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1578 
1579 	local->rx_pending = NULL;
1580 	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1581 
1582 	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1583 
1584 	rwlock_init(&local->sockets.lock);
1585 	rwlock_init(&local->connecting_sockets.lock);
1586 	rwlock_init(&local->raw_sockets.lock);
1587 
1588 	local->lto = 150; /* 1500 ms */
1589 	local->rw = LLCP_MAX_RW;
1590 	local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1591 	local->local_wks = 0x1; /* LLC Link Management */
1592 
1593 	nfc_llcp_build_gb(local);
1594 
1595 	local->remote_miu = LLCP_DEFAULT_MIU;
1596 	local->remote_lto = LLCP_DEFAULT_LTO;
1597 
1598 	mutex_init(&local->sdreq_lock);
1599 	INIT_HLIST_HEAD(&local->pending_sdreqs);
1600 	timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0);
1601 	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
1602 
1603 	list_add(&local->list, &llcp_devices);
1604 
1605 	return 0;
1606 }
1607 
1608 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1609 {
1610 	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
1611 
1612 	if (local == NULL) {
1613 		pr_debug("No such device\n");
1614 		return;
1615 	}
1616 
1617 	local_cleanup(local);
1618 
1619 	nfc_llcp_local_put(local);
1620 }
1621 
1622 int __init nfc_llcp_init(void)
1623 {
1624 	return nfc_llcp_sock_init();
1625 }
1626 
1627 void nfc_llcp_exit(void)
1628 {
1629 	nfc_llcp_sock_exit();
1630 }
1631