xref: /openbmc/linux/net/nfc/llcp_core.c (revision 0545810f)
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 	local->rx_pending = NULL;
161 	del_timer_sync(&local->sdreq_timer);
162 	cancel_work_sync(&local->sdreq_timeout_work);
163 	nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);
164 }
165 
166 static void local_release(struct kref *ref)
167 {
168 	struct nfc_llcp_local *local;
169 
170 	local = container_of(ref, struct nfc_llcp_local, ref);
171 
172 	list_del(&local->list);
173 	local_cleanup(local);
174 	kfree(local);
175 }
176 
177 int nfc_llcp_local_put(struct nfc_llcp_local *local)
178 {
179 	if (local == NULL)
180 		return 0;
181 
182 	return kref_put(&local->ref, local_release);
183 }
184 
185 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
186 					       u8 ssap, u8 dsap)
187 {
188 	struct sock *sk;
189 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
190 
191 	pr_debug("ssap dsap %d %d\n", ssap, dsap);
192 
193 	if (ssap == 0 && dsap == 0)
194 		return NULL;
195 
196 	read_lock(&local->sockets.lock);
197 
198 	llcp_sock = NULL;
199 
200 	sk_for_each(sk, &local->sockets.head) {
201 		tmp_sock = nfc_llcp_sock(sk);
202 
203 		if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
204 			llcp_sock = tmp_sock;
205 			break;
206 		}
207 	}
208 
209 	read_unlock(&local->sockets.lock);
210 
211 	if (llcp_sock == NULL)
212 		return NULL;
213 
214 	sock_hold(&llcp_sock->sk);
215 
216 	return llcp_sock;
217 }
218 
219 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
220 {
221 	sock_put(&sock->sk);
222 }
223 
224 static void nfc_llcp_timeout_work(struct work_struct *work)
225 {
226 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
227 						    timeout_work);
228 
229 	nfc_dep_link_down(local->dev);
230 }
231 
232 static void nfc_llcp_symm_timer(struct timer_list *t)
233 {
234 	struct nfc_llcp_local *local = from_timer(local, t, link_timer);
235 
236 	pr_err("SYMM timeout\n");
237 
238 	schedule_work(&local->timeout_work);
239 }
240 
241 static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
242 {
243 	unsigned long time;
244 	HLIST_HEAD(nl_sdres_list);
245 	struct hlist_node *n;
246 	struct nfc_llcp_sdp_tlv *sdp;
247 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
248 						    sdreq_timeout_work);
249 
250 	mutex_lock(&local->sdreq_lock);
251 
252 	time = jiffies - msecs_to_jiffies(3 * local->remote_lto);
253 
254 	hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) {
255 		if (time_after(sdp->time, time))
256 			continue;
257 
258 		sdp->sap = LLCP_SDP_UNBOUND;
259 
260 		hlist_del(&sdp->node);
261 
262 		hlist_add_head(&sdp->node, &nl_sdres_list);
263 	}
264 
265 	if (!hlist_empty(&local->pending_sdreqs))
266 		mod_timer(&local->sdreq_timer,
267 			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
268 
269 	mutex_unlock(&local->sdreq_lock);
270 
271 	if (!hlist_empty(&nl_sdres_list))
272 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
273 }
274 
275 static void nfc_llcp_sdreq_timer(struct timer_list *t)
276 {
277 	struct nfc_llcp_local *local = from_timer(local, t, sdreq_timer);
278 
279 	schedule_work(&local->sdreq_timeout_work);
280 }
281 
282 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
283 {
284 	struct nfc_llcp_local *local;
285 
286 	list_for_each_entry(local, &llcp_devices, list)
287 		if (local->dev == dev)
288 			return local;
289 
290 	pr_debug("No device found\n");
291 
292 	return NULL;
293 }
294 
295 static char *wks[] = {
296 	NULL,
297 	NULL, /* SDP */
298 	"urn:nfc:sn:ip",
299 	"urn:nfc:sn:obex",
300 	"urn:nfc:sn:snep",
301 };
302 
303 static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len)
304 {
305 	int sap, num_wks;
306 
307 	pr_debug("%s\n", service_name);
308 
309 	if (service_name == NULL)
310 		return -EINVAL;
311 
312 	num_wks = ARRAY_SIZE(wks);
313 
314 	for (sap = 0; sap < num_wks; sap++) {
315 		if (wks[sap] == NULL)
316 			continue;
317 
318 		if (strncmp(wks[sap], service_name, service_name_len) == 0)
319 			return sap;
320 	}
321 
322 	return -EINVAL;
323 }
324 
325 static
326 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
327 					    const u8 *sn, size_t sn_len)
328 {
329 	struct sock *sk;
330 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
331 
332 	pr_debug("sn %zd %p\n", sn_len, sn);
333 
334 	if (sn == NULL || sn_len == 0)
335 		return NULL;
336 
337 	read_lock(&local->sockets.lock);
338 
339 	llcp_sock = NULL;
340 
341 	sk_for_each(sk, &local->sockets.head) {
342 		tmp_sock = nfc_llcp_sock(sk);
343 
344 		pr_debug("llcp sock %p\n", tmp_sock);
345 
346 		if (tmp_sock->sk.sk_type == SOCK_STREAM &&
347 		    tmp_sock->sk.sk_state != LLCP_LISTEN)
348 			continue;
349 
350 		if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
351 		    tmp_sock->sk.sk_state != LLCP_BOUND)
352 			continue;
353 
354 		if (tmp_sock->service_name == NULL ||
355 		    tmp_sock->service_name_len == 0)
356 			continue;
357 
358 		if (tmp_sock->service_name_len != sn_len)
359 			continue;
360 
361 		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
362 			llcp_sock = tmp_sock;
363 			break;
364 		}
365 	}
366 
367 	read_unlock(&local->sockets.lock);
368 
369 	pr_debug("Found llcp sock %p\n", llcp_sock);
370 
371 	return llcp_sock;
372 }
373 
374 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
375 			 struct nfc_llcp_sock *sock)
376 {
377 	mutex_lock(&local->sdp_lock);
378 
379 	if (sock->service_name != NULL && sock->service_name_len > 0) {
380 		int ssap = nfc_llcp_wks_sap(sock->service_name,
381 					    sock->service_name_len);
382 
383 		if (ssap > 0) {
384 			pr_debug("WKS %d\n", ssap);
385 
386 			/* This is a WKS, let's check if it's free */
387 			if (test_bit(ssap, &local->local_wks)) {
388 				mutex_unlock(&local->sdp_lock);
389 
390 				return LLCP_SAP_MAX;
391 			}
392 
393 			set_bit(ssap, &local->local_wks);
394 			mutex_unlock(&local->sdp_lock);
395 
396 			return ssap;
397 		}
398 
399 		/*
400 		 * Check if there already is a non WKS socket bound
401 		 * to this service name.
402 		 */
403 		if (nfc_llcp_sock_from_sn(local, sock->service_name,
404 					  sock->service_name_len) != NULL) {
405 			mutex_unlock(&local->sdp_lock);
406 
407 			return LLCP_SAP_MAX;
408 		}
409 
410 		mutex_unlock(&local->sdp_lock);
411 
412 		return LLCP_SDP_UNBOUND;
413 
414 	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
415 		if (!test_bit(sock->ssap, &local->local_wks)) {
416 			set_bit(sock->ssap, &local->local_wks);
417 			mutex_unlock(&local->sdp_lock);
418 
419 			return sock->ssap;
420 		}
421 	}
422 
423 	mutex_unlock(&local->sdp_lock);
424 
425 	return LLCP_SAP_MAX;
426 }
427 
428 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
429 {
430 	u8 local_ssap;
431 
432 	mutex_lock(&local->sdp_lock);
433 
434 	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
435 	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
436 		mutex_unlock(&local->sdp_lock);
437 		return LLCP_SAP_MAX;
438 	}
439 
440 	set_bit(local_ssap, &local->local_sap);
441 
442 	mutex_unlock(&local->sdp_lock);
443 
444 	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
445 }
446 
447 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
448 {
449 	u8 local_ssap;
450 	unsigned long *sdp;
451 
452 	if (ssap < LLCP_WKS_NUM_SAP) {
453 		local_ssap = ssap;
454 		sdp = &local->local_wks;
455 	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
456 		atomic_t *client_cnt;
457 
458 		local_ssap = ssap - LLCP_WKS_NUM_SAP;
459 		sdp = &local->local_sdp;
460 		client_cnt = &local->local_sdp_cnt[local_ssap];
461 
462 		pr_debug("%d clients\n", atomic_read(client_cnt));
463 
464 		mutex_lock(&local->sdp_lock);
465 
466 		if (atomic_dec_and_test(client_cnt)) {
467 			struct nfc_llcp_sock *l_sock;
468 
469 			pr_debug("No more clients for SAP %d\n", ssap);
470 
471 			clear_bit(local_ssap, sdp);
472 
473 			/* Find the listening sock and set it back to UNBOUND */
474 			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
475 			if (l_sock) {
476 				l_sock->ssap = LLCP_SDP_UNBOUND;
477 				nfc_llcp_sock_put(l_sock);
478 			}
479 		}
480 
481 		mutex_unlock(&local->sdp_lock);
482 
483 		return;
484 	} else if (ssap < LLCP_MAX_SAP) {
485 		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
486 		sdp = &local->local_sap;
487 	} else {
488 		return;
489 	}
490 
491 	mutex_lock(&local->sdp_lock);
492 
493 	clear_bit(local_ssap, sdp);
494 
495 	mutex_unlock(&local->sdp_lock);
496 }
497 
498 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
499 {
500 	u8 ssap;
501 
502 	mutex_lock(&local->sdp_lock);
503 
504 	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
505 	if (ssap == LLCP_SDP_NUM_SAP) {
506 		mutex_unlock(&local->sdp_lock);
507 
508 		return LLCP_SAP_MAX;
509 	}
510 
511 	pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
512 
513 	set_bit(ssap, &local->local_sdp);
514 
515 	mutex_unlock(&local->sdp_lock);
516 
517 	return LLCP_WKS_NUM_SAP + ssap;
518 }
519 
520 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
521 {
522 	u8 *gb_cur, version, version_length;
523 	u8 lto_length, wks_length, miux_length;
524 	const u8 *version_tlv = NULL, *lto_tlv = NULL,
525 	   *wks_tlv = NULL, *miux_tlv = NULL;
526 	__be16 wks = cpu_to_be16(local->local_wks);
527 	u8 gb_len = 0;
528 	int ret = 0;
529 
530 	version = LLCP_VERSION_11;
531 	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
532 					 1, &version_length);
533 	if (!version_tlv) {
534 		ret = -ENOMEM;
535 		goto out;
536 	}
537 	gb_len += version_length;
538 
539 	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
540 	if (!lto_tlv) {
541 		ret = -ENOMEM;
542 		goto out;
543 	}
544 	gb_len += lto_length;
545 
546 	pr_debug("Local wks 0x%lx\n", local->local_wks);
547 	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
548 	if (!wks_tlv) {
549 		ret = -ENOMEM;
550 		goto out;
551 	}
552 	gb_len += wks_length;
553 
554 	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
555 				      &miux_length);
556 	if (!miux_tlv) {
557 		ret = -ENOMEM;
558 		goto out;
559 	}
560 	gb_len += miux_length;
561 
562 	gb_len += ARRAY_SIZE(llcp_magic);
563 
564 	if (gb_len > NFC_MAX_GT_LEN) {
565 		ret = -EINVAL;
566 		goto out;
567 	}
568 
569 	gb_cur = local->gb;
570 
571 	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
572 	gb_cur += ARRAY_SIZE(llcp_magic);
573 
574 	memcpy(gb_cur, version_tlv, version_length);
575 	gb_cur += version_length;
576 
577 	memcpy(gb_cur, lto_tlv, lto_length);
578 	gb_cur += lto_length;
579 
580 	memcpy(gb_cur, wks_tlv, wks_length);
581 	gb_cur += wks_length;
582 
583 	memcpy(gb_cur, miux_tlv, miux_length);
584 	gb_cur += miux_length;
585 
586 	local->gb_len = gb_len;
587 
588 out:
589 	kfree(version_tlv);
590 	kfree(lto_tlv);
591 	kfree(wks_tlv);
592 	kfree(miux_tlv);
593 
594 	return ret;
595 }
596 
597 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
598 {
599 	struct nfc_llcp_local *local;
600 
601 	local = nfc_llcp_find_local(dev);
602 	if (local == NULL) {
603 		*general_bytes_len = 0;
604 		return NULL;
605 	}
606 
607 	nfc_llcp_build_gb(local);
608 
609 	*general_bytes_len = local->gb_len;
610 
611 	return local->gb;
612 }
613 
614 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, const u8 *gb, u8 gb_len)
615 {
616 	struct nfc_llcp_local *local;
617 
618 	if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
619 		return -EINVAL;
620 
621 	local = nfc_llcp_find_local(dev);
622 	if (local == NULL) {
623 		pr_err("No LLCP device\n");
624 		return -ENODEV;
625 	}
626 
627 	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
628 	memcpy(local->remote_gb, gb, gb_len);
629 	local->remote_gb_len = gb_len;
630 
631 	if (memcmp(local->remote_gb, llcp_magic, 3)) {
632 		pr_err("MAC does not support LLCP\n");
633 		return -EINVAL;
634 	}
635 
636 	return nfc_llcp_parse_gb_tlv(local,
637 				     &local->remote_gb[3],
638 				     local->remote_gb_len - 3);
639 }
640 
641 static u8 nfc_llcp_dsap(const struct sk_buff *pdu)
642 {
643 	return (pdu->data[0] & 0xfc) >> 2;
644 }
645 
646 static u8 nfc_llcp_ptype(const struct sk_buff *pdu)
647 {
648 	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
649 }
650 
651 static u8 nfc_llcp_ssap(const struct sk_buff *pdu)
652 {
653 	return pdu->data[1] & 0x3f;
654 }
655 
656 static u8 nfc_llcp_ns(const struct sk_buff *pdu)
657 {
658 	return pdu->data[2] >> 4;
659 }
660 
661 static u8 nfc_llcp_nr(const struct sk_buff *pdu)
662 {
663 	return pdu->data[2] & 0xf;
664 }
665 
666 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
667 {
668 	pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
669 	sock->send_n = (sock->send_n + 1) % 16;
670 	sock->recv_ack_n = (sock->recv_n - 1) % 16;
671 }
672 
673 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
674 			       struct sk_buff *skb, u8 direction)
675 {
676 	struct sk_buff *skb_copy = NULL, *nskb;
677 	struct sock *sk;
678 	u8 *data;
679 
680 	read_lock(&local->raw_sockets.lock);
681 
682 	sk_for_each(sk, &local->raw_sockets.head) {
683 		if (sk->sk_state != LLCP_BOUND)
684 			continue;
685 
686 		if (skb_copy == NULL) {
687 			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
688 						      GFP_ATOMIC, true);
689 
690 			if (skb_copy == NULL)
691 				continue;
692 
693 			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
694 
695 			data[0] = local->dev ? local->dev->idx : 0xFF;
696 			data[1] = direction & 0x01;
697 			data[1] |= (RAW_PAYLOAD_LLCP << 1);
698 		}
699 
700 		nskb = skb_clone(skb_copy, GFP_ATOMIC);
701 		if (!nskb)
702 			continue;
703 
704 		if (sock_queue_rcv_skb(sk, nskb))
705 			kfree_skb(nskb);
706 	}
707 
708 	read_unlock(&local->raw_sockets.lock);
709 
710 	kfree_skb(skb_copy);
711 }
712 
713 static void nfc_llcp_tx_work(struct work_struct *work)
714 {
715 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
716 						    tx_work);
717 	struct sk_buff *skb;
718 	struct sock *sk;
719 	struct nfc_llcp_sock *llcp_sock;
720 
721 	skb = skb_dequeue(&local->tx_queue);
722 	if (skb != NULL) {
723 		sk = skb->sk;
724 		llcp_sock = nfc_llcp_sock(sk);
725 
726 		if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
727 			kfree_skb(skb);
728 			nfc_llcp_send_symm(local->dev);
729 		} else if (llcp_sock && !llcp_sock->remote_ready) {
730 			skb_queue_head(&local->tx_queue, skb);
731 			nfc_llcp_send_symm(local->dev);
732 		} else {
733 			struct sk_buff *copy_skb = NULL;
734 			u8 ptype = nfc_llcp_ptype(skb);
735 			int ret;
736 
737 			pr_debug("Sending pending skb\n");
738 			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
739 					     16, 1, skb->data, skb->len, true);
740 
741 			if (ptype == LLCP_PDU_I)
742 				copy_skb = skb_copy(skb, GFP_ATOMIC);
743 
744 			__net_timestamp(skb);
745 
746 			nfc_llcp_send_to_raw_sock(local, skb,
747 						  NFC_DIRECTION_TX);
748 
749 			ret = nfc_data_exchange(local->dev, local->target_idx,
750 						skb, nfc_llcp_recv, local);
751 
752 			if (ret) {
753 				kfree_skb(copy_skb);
754 				goto out;
755 			}
756 
757 			if (ptype == LLCP_PDU_I && copy_skb)
758 				skb_queue_tail(&llcp_sock->tx_pending_queue,
759 					       copy_skb);
760 		}
761 	} else {
762 		nfc_llcp_send_symm(local->dev);
763 	}
764 
765 out:
766 	mod_timer(&local->link_timer,
767 		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
768 }
769 
770 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
771 							  u8 ssap)
772 {
773 	struct sock *sk;
774 	struct nfc_llcp_sock *llcp_sock;
775 
776 	read_lock(&local->connecting_sockets.lock);
777 
778 	sk_for_each(sk, &local->connecting_sockets.head) {
779 		llcp_sock = nfc_llcp_sock(sk);
780 
781 		if (llcp_sock->ssap == ssap) {
782 			sock_hold(&llcp_sock->sk);
783 			goto out;
784 		}
785 	}
786 
787 	llcp_sock = NULL;
788 
789 out:
790 	read_unlock(&local->connecting_sockets.lock);
791 
792 	return llcp_sock;
793 }
794 
795 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
796 						  const u8 *sn, size_t sn_len)
797 {
798 	struct nfc_llcp_sock *llcp_sock;
799 
800 	llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
801 
802 	if (llcp_sock == NULL)
803 		return NULL;
804 
805 	sock_hold(&llcp_sock->sk);
806 
807 	return llcp_sock;
808 }
809 
810 static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
811 {
812 	u8 type, length;
813 	const u8 *tlv = &skb->data[2];
814 	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
815 
816 	while (offset < tlv_array_len) {
817 		type = tlv[0];
818 		length = tlv[1];
819 
820 		pr_debug("type 0x%x length %d\n", type, length);
821 
822 		if (type == LLCP_TLV_SN) {
823 			*sn_len = length;
824 			return &tlv[2];
825 		}
826 
827 		offset += length + 2;
828 		tlv += length + 2;
829 	}
830 
831 	return NULL;
832 }
833 
834 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
835 			     struct sk_buff *skb)
836 {
837 	struct nfc_llcp_sock *llcp_sock;
838 	struct nfc_llcp_ui_cb *ui_cb;
839 	u8 dsap, ssap;
840 
841 	dsap = nfc_llcp_dsap(skb);
842 	ssap = nfc_llcp_ssap(skb);
843 
844 	ui_cb = nfc_llcp_ui_skb_cb(skb);
845 	ui_cb->dsap = dsap;
846 	ui_cb->ssap = ssap;
847 
848 	pr_debug("%d %d\n", dsap, ssap);
849 
850 	/* We're looking for a bound socket, not a client one */
851 	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
852 	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
853 		return;
854 
855 	/* There is no sequence with UI frames */
856 	skb_pull(skb, LLCP_HEADER_SIZE);
857 	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
858 		/*
859 		 * UI frames will be freed from the socket layer, so we
860 		 * need to keep them alive until someone receives them.
861 		 */
862 		skb_get(skb);
863 	} else {
864 		pr_err("Receive queue is full\n");
865 	}
866 
867 	nfc_llcp_sock_put(llcp_sock);
868 }
869 
870 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
871 				  const struct sk_buff *skb)
872 {
873 	struct sock *new_sk, *parent;
874 	struct nfc_llcp_sock *sock, *new_sock;
875 	u8 dsap, ssap, reason;
876 
877 	dsap = nfc_llcp_dsap(skb);
878 	ssap = nfc_llcp_ssap(skb);
879 
880 	pr_debug("%d %d\n", dsap, ssap);
881 
882 	if (dsap != LLCP_SAP_SDP) {
883 		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
884 		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
885 			reason = LLCP_DM_NOBOUND;
886 			goto fail;
887 		}
888 	} else {
889 		const u8 *sn;
890 		size_t sn_len;
891 
892 		sn = nfc_llcp_connect_sn(skb, &sn_len);
893 		if (sn == NULL) {
894 			reason = LLCP_DM_NOBOUND;
895 			goto fail;
896 		}
897 
898 		pr_debug("Service name length %zu\n", sn_len);
899 
900 		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
901 		if (sock == NULL) {
902 			reason = LLCP_DM_NOBOUND;
903 			goto fail;
904 		}
905 	}
906 
907 	lock_sock(&sock->sk);
908 
909 	parent = &sock->sk;
910 
911 	if (sk_acceptq_is_full(parent)) {
912 		reason = LLCP_DM_REJ;
913 		release_sock(&sock->sk);
914 		sock_put(&sock->sk);
915 		goto fail;
916 	}
917 
918 	if (sock->ssap == LLCP_SDP_UNBOUND) {
919 		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
920 
921 		pr_debug("First client, reserving %d\n", ssap);
922 
923 		if (ssap == LLCP_SAP_MAX) {
924 			reason = LLCP_DM_REJ;
925 			release_sock(&sock->sk);
926 			sock_put(&sock->sk);
927 			goto fail;
928 		}
929 
930 		sock->ssap = ssap;
931 	}
932 
933 	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
934 	if (new_sk == NULL) {
935 		reason = LLCP_DM_REJ;
936 		release_sock(&sock->sk);
937 		sock_put(&sock->sk);
938 		goto fail;
939 	}
940 
941 	new_sock = nfc_llcp_sock(new_sk);
942 	new_sock->dev = local->dev;
943 	new_sock->local = nfc_llcp_local_get(local);
944 	new_sock->rw = sock->rw;
945 	new_sock->miux = sock->miux;
946 	new_sock->nfc_protocol = sock->nfc_protocol;
947 	new_sock->dsap = ssap;
948 	new_sock->target_idx = local->target_idx;
949 	new_sock->parent = parent;
950 	new_sock->ssap = sock->ssap;
951 	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
952 		atomic_t *client_count;
953 
954 		pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
955 
956 		client_count =
957 			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
958 
959 		atomic_inc(client_count);
960 		new_sock->reserved_ssap = sock->ssap;
961 	}
962 
963 	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
964 				      skb->len - LLCP_HEADER_SIZE);
965 
966 	pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
967 
968 	nfc_llcp_sock_link(&local->sockets, new_sk);
969 
970 	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
971 
972 	nfc_get_device(local->dev->idx);
973 
974 	new_sk->sk_state = LLCP_CONNECTED;
975 
976 	/* Wake the listening processes */
977 	parent->sk_data_ready(parent);
978 
979 	/* Send CC */
980 	nfc_llcp_send_cc(new_sock);
981 
982 	release_sock(&sock->sk);
983 	sock_put(&sock->sk);
984 
985 	return;
986 
987 fail:
988 	/* Send DM */
989 	nfc_llcp_send_dm(local, dsap, ssap, reason);
990 }
991 
992 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
993 {
994 	int nr_frames = 0;
995 	struct nfc_llcp_local *local = sock->local;
996 
997 	pr_debug("Remote ready %d tx queue len %d remote rw %d",
998 		 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
999 		 sock->remote_rw);
1000 
1001 	/* Try to queue some I frames for transmission */
1002 	while (sock->remote_ready &&
1003 	       skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {
1004 		struct sk_buff *pdu;
1005 
1006 		pdu = skb_dequeue(&sock->tx_queue);
1007 		if (pdu == NULL)
1008 			break;
1009 
1010 		/* Update N(S)/N(R) */
1011 		nfc_llcp_set_nrns(sock, pdu);
1012 
1013 		skb_queue_tail(&local->tx_queue, pdu);
1014 		nr_frames++;
1015 	}
1016 
1017 	return nr_frames;
1018 }
1019 
1020 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
1021 			       struct sk_buff *skb)
1022 {
1023 	struct nfc_llcp_sock *llcp_sock;
1024 	struct sock *sk;
1025 	u8 dsap, ssap, ptype, ns, nr;
1026 
1027 	ptype = nfc_llcp_ptype(skb);
1028 	dsap = nfc_llcp_dsap(skb);
1029 	ssap = nfc_llcp_ssap(skb);
1030 	ns = nfc_llcp_ns(skb);
1031 	nr = nfc_llcp_nr(skb);
1032 
1033 	pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
1034 
1035 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1036 	if (llcp_sock == NULL) {
1037 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1038 		return;
1039 	}
1040 
1041 	sk = &llcp_sock->sk;
1042 	lock_sock(sk);
1043 	if (sk->sk_state == LLCP_CLOSED) {
1044 		release_sock(sk);
1045 		nfc_llcp_sock_put(llcp_sock);
1046 	}
1047 
1048 	/* Pass the payload upstream */
1049 	if (ptype == LLCP_PDU_I) {
1050 		pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
1051 
1052 		if (ns == llcp_sock->recv_n)
1053 			llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
1054 		else
1055 			pr_err("Received out of sequence I PDU\n");
1056 
1057 		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
1058 		if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
1059 			/*
1060 			 * I frames will be freed from the socket layer, so we
1061 			 * need to keep them alive until someone receives them.
1062 			 */
1063 			skb_get(skb);
1064 		} else {
1065 			pr_err("Receive queue is full\n");
1066 		}
1067 	}
1068 
1069 	/* Remove skbs from the pending queue */
1070 	if (llcp_sock->send_ack_n != nr) {
1071 		struct sk_buff *s, *tmp;
1072 		u8 n;
1073 
1074 		llcp_sock->send_ack_n = nr;
1075 
1076 		/* Remove and free all skbs until ns == nr */
1077 		skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
1078 			n = nfc_llcp_ns(s);
1079 
1080 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1081 			kfree_skb(s);
1082 
1083 			if (n == nr)
1084 				break;
1085 		}
1086 
1087 		/* Re-queue the remaining skbs for transmission */
1088 		skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1089 					    s, tmp) {
1090 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1091 			skb_queue_head(&local->tx_queue, s);
1092 		}
1093 	}
1094 
1095 	if (ptype == LLCP_PDU_RR)
1096 		llcp_sock->remote_ready = true;
1097 	else if (ptype == LLCP_PDU_RNR)
1098 		llcp_sock->remote_ready = false;
1099 
1100 	if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1101 		nfc_llcp_send_rr(llcp_sock);
1102 
1103 	release_sock(sk);
1104 	nfc_llcp_sock_put(llcp_sock);
1105 }
1106 
1107 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1108 			       const struct sk_buff *skb)
1109 {
1110 	struct nfc_llcp_sock *llcp_sock;
1111 	struct sock *sk;
1112 	u8 dsap, ssap;
1113 
1114 	dsap = nfc_llcp_dsap(skb);
1115 	ssap = nfc_llcp_ssap(skb);
1116 
1117 	if ((dsap == 0) && (ssap == 0)) {
1118 		pr_debug("Connection termination");
1119 		nfc_dep_link_down(local->dev);
1120 		return;
1121 	}
1122 
1123 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1124 	if (llcp_sock == NULL) {
1125 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1126 		return;
1127 	}
1128 
1129 	sk = &llcp_sock->sk;
1130 	lock_sock(sk);
1131 
1132 	nfc_llcp_socket_purge(llcp_sock);
1133 
1134 	if (sk->sk_state == LLCP_CLOSED) {
1135 		release_sock(sk);
1136 		nfc_llcp_sock_put(llcp_sock);
1137 	}
1138 
1139 	if (sk->sk_state == LLCP_CONNECTED) {
1140 		nfc_put_device(local->dev);
1141 		sk->sk_state = LLCP_CLOSED;
1142 		sk->sk_state_change(sk);
1143 	}
1144 
1145 	nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1146 
1147 	release_sock(sk);
1148 	nfc_llcp_sock_put(llcp_sock);
1149 }
1150 
1151 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local,
1152 			     const struct sk_buff *skb)
1153 {
1154 	struct nfc_llcp_sock *llcp_sock;
1155 	struct sock *sk;
1156 	u8 dsap, ssap;
1157 
1158 	dsap = nfc_llcp_dsap(skb);
1159 	ssap = nfc_llcp_ssap(skb);
1160 
1161 	llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1162 	if (llcp_sock == NULL) {
1163 		pr_err("Invalid CC\n");
1164 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1165 
1166 		return;
1167 	}
1168 
1169 	sk = &llcp_sock->sk;
1170 
1171 	/* Unlink from connecting and link to the client array */
1172 	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1173 	nfc_llcp_sock_link(&local->sockets, sk);
1174 	llcp_sock->dsap = ssap;
1175 
1176 	nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1177 				      skb->len - LLCP_HEADER_SIZE);
1178 
1179 	sk->sk_state = LLCP_CONNECTED;
1180 	sk->sk_state_change(sk);
1181 
1182 	nfc_llcp_sock_put(llcp_sock);
1183 }
1184 
1185 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local,
1186 			     const struct sk_buff *skb)
1187 {
1188 	struct nfc_llcp_sock *llcp_sock;
1189 	struct sock *sk;
1190 	u8 dsap, ssap, reason;
1191 
1192 	dsap = nfc_llcp_dsap(skb);
1193 	ssap = nfc_llcp_ssap(skb);
1194 	reason = skb->data[2];
1195 
1196 	pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1197 
1198 	switch (reason) {
1199 	case LLCP_DM_NOBOUND:
1200 	case LLCP_DM_REJ:
1201 		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1202 		break;
1203 
1204 	default:
1205 		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1206 		break;
1207 	}
1208 
1209 	if (llcp_sock == NULL) {
1210 		pr_debug("Already closed\n");
1211 		return;
1212 	}
1213 
1214 	sk = &llcp_sock->sk;
1215 
1216 	sk->sk_err = ENXIO;
1217 	sk->sk_state = LLCP_CLOSED;
1218 	sk->sk_state_change(sk);
1219 
1220 	nfc_llcp_sock_put(llcp_sock);
1221 }
1222 
1223 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1224 			      const struct sk_buff *skb)
1225 {
1226 	struct nfc_llcp_sock *llcp_sock;
1227 	u8 dsap, ssap, type, length, tid, sap;
1228 	const u8 *tlv;
1229 	u16 tlv_len, offset;
1230 	const 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 		skb_put_data(new_skb, 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 	if (err < 0) {
1501 		pr_err("LLCP PDU receive err %d\n", err);
1502 		return;
1503 	}
1504 
1505 	__nfc_llcp_recv(local, skb);
1506 }
1507 
1508 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1509 {
1510 	struct nfc_llcp_local *local;
1511 
1512 	local = nfc_llcp_find_local(dev);
1513 	if (local == NULL) {
1514 		kfree_skb(skb);
1515 		return -ENODEV;
1516 	}
1517 
1518 	__nfc_llcp_recv(local, skb);
1519 
1520 	return 0;
1521 }
1522 
1523 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1524 {
1525 	struct nfc_llcp_local *local;
1526 
1527 	local = nfc_llcp_find_local(dev);
1528 	if (local == NULL)
1529 		return;
1530 
1531 	local->remote_miu = LLCP_DEFAULT_MIU;
1532 	local->remote_lto = LLCP_DEFAULT_LTO;
1533 
1534 	/* Close and purge all existing sockets */
1535 	nfc_llcp_socket_release(local, true, 0);
1536 }
1537 
1538 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1539 			u8 comm_mode, u8 rf_mode)
1540 {
1541 	struct nfc_llcp_local *local;
1542 
1543 	pr_debug("rf mode %d\n", rf_mode);
1544 
1545 	local = nfc_llcp_find_local(dev);
1546 	if (local == NULL)
1547 		return;
1548 
1549 	local->target_idx = target_idx;
1550 	local->comm_mode = comm_mode;
1551 	local->rf_mode = rf_mode;
1552 
1553 	if (rf_mode == NFC_RF_INITIATOR) {
1554 		pr_debug("Queueing Tx work\n");
1555 
1556 		schedule_work(&local->tx_work);
1557 	} else {
1558 		mod_timer(&local->link_timer,
1559 			  jiffies + msecs_to_jiffies(local->remote_lto));
1560 	}
1561 }
1562 
1563 int nfc_llcp_register_device(struct nfc_dev *ndev)
1564 {
1565 	struct nfc_llcp_local *local;
1566 
1567 	local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1568 	if (local == NULL)
1569 		return -ENOMEM;
1570 
1571 	local->dev = ndev;
1572 	INIT_LIST_HEAD(&local->list);
1573 	kref_init(&local->ref);
1574 	mutex_init(&local->sdp_lock);
1575 	timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0);
1576 
1577 	skb_queue_head_init(&local->tx_queue);
1578 	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1579 
1580 	local->rx_pending = NULL;
1581 	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1582 
1583 	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1584 
1585 	rwlock_init(&local->sockets.lock);
1586 	rwlock_init(&local->connecting_sockets.lock);
1587 	rwlock_init(&local->raw_sockets.lock);
1588 
1589 	local->lto = 150; /* 1500 ms */
1590 	local->rw = LLCP_MAX_RW;
1591 	local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1592 	local->local_wks = 0x1; /* LLC Link Management */
1593 
1594 	nfc_llcp_build_gb(local);
1595 
1596 	local->remote_miu = LLCP_DEFAULT_MIU;
1597 	local->remote_lto = LLCP_DEFAULT_LTO;
1598 
1599 	mutex_init(&local->sdreq_lock);
1600 	INIT_HLIST_HEAD(&local->pending_sdreqs);
1601 	timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0);
1602 	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
1603 
1604 	list_add(&local->list, &llcp_devices);
1605 
1606 	return 0;
1607 }
1608 
1609 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1610 {
1611 	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
1612 
1613 	if (local == NULL) {
1614 		pr_debug("No such device\n");
1615 		return;
1616 	}
1617 
1618 	local_cleanup(local);
1619 
1620 	nfc_llcp_local_put(local);
1621 }
1622 
1623 int __init nfc_llcp_init(void)
1624 {
1625 	return nfc_llcp_sock_init();
1626 }
1627 
1628 void nfc_llcp_exit(void)
1629 {
1630 	nfc_llcp_sock_exit();
1631 }
1632