xref: /openbmc/linux/net/nfc/llcp_core.c (revision b7b3c35e)
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 (local->local_wks & BIT(ssap)) {
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_DISC && sk != NULL &&
741 			    sk->sk_state == LLCP_DISCONNECTING) {
742 				nfc_llcp_sock_unlink(&local->sockets, sk);
743 				sock_orphan(sk);
744 				sock_put(sk);
745 			}
746 
747 			if (ptype == LLCP_PDU_I)
748 				copy_skb = skb_copy(skb, GFP_ATOMIC);
749 
750 			__net_timestamp(skb);
751 
752 			nfc_llcp_send_to_raw_sock(local, skb,
753 						  NFC_DIRECTION_TX);
754 
755 			ret = nfc_data_exchange(local->dev, local->target_idx,
756 						skb, nfc_llcp_recv, local);
757 
758 			if (ret) {
759 				kfree_skb(copy_skb);
760 				goto out;
761 			}
762 
763 			if (ptype == LLCP_PDU_I && copy_skb)
764 				skb_queue_tail(&llcp_sock->tx_pending_queue,
765 					       copy_skb);
766 		}
767 	} else {
768 		nfc_llcp_send_symm(local->dev);
769 	}
770 
771 out:
772 	mod_timer(&local->link_timer,
773 		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
774 }
775 
776 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
777 							  u8 ssap)
778 {
779 	struct sock *sk;
780 	struct nfc_llcp_sock *llcp_sock;
781 
782 	read_lock(&local->connecting_sockets.lock);
783 
784 	sk_for_each(sk, &local->connecting_sockets.head) {
785 		llcp_sock = nfc_llcp_sock(sk);
786 
787 		if (llcp_sock->ssap == ssap) {
788 			sock_hold(&llcp_sock->sk);
789 			goto out;
790 		}
791 	}
792 
793 	llcp_sock = NULL;
794 
795 out:
796 	read_unlock(&local->connecting_sockets.lock);
797 
798 	return llcp_sock;
799 }
800 
801 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
802 						  const u8 *sn, size_t sn_len)
803 {
804 	struct nfc_llcp_sock *llcp_sock;
805 
806 	llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
807 
808 	if (llcp_sock == NULL)
809 		return NULL;
810 
811 	sock_hold(&llcp_sock->sk);
812 
813 	return llcp_sock;
814 }
815 
816 static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
817 {
818 	u8 type, length;
819 	const u8 *tlv = &skb->data[2];
820 	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
821 
822 	while (offset < tlv_array_len) {
823 		type = tlv[0];
824 		length = tlv[1];
825 
826 		pr_debug("type 0x%x length %d\n", type, length);
827 
828 		if (type == LLCP_TLV_SN) {
829 			*sn_len = length;
830 			return &tlv[2];
831 		}
832 
833 		offset += length + 2;
834 		tlv += length + 2;
835 	}
836 
837 	return NULL;
838 }
839 
840 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
841 			     struct sk_buff *skb)
842 {
843 	struct nfc_llcp_sock *llcp_sock;
844 	struct nfc_llcp_ui_cb *ui_cb;
845 	u8 dsap, ssap;
846 
847 	dsap = nfc_llcp_dsap(skb);
848 	ssap = nfc_llcp_ssap(skb);
849 
850 	ui_cb = nfc_llcp_ui_skb_cb(skb);
851 	ui_cb->dsap = dsap;
852 	ui_cb->ssap = ssap;
853 
854 	pr_debug("%d %d\n", dsap, ssap);
855 
856 	/* We're looking for a bound socket, not a client one */
857 	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
858 	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
859 		return;
860 
861 	/* There is no sequence with UI frames */
862 	skb_pull(skb, LLCP_HEADER_SIZE);
863 	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
864 		/*
865 		 * UI frames will be freed from the socket layer, so we
866 		 * need to keep them alive until someone receives them.
867 		 */
868 		skb_get(skb);
869 	} else {
870 		pr_err("Receive queue is full\n");
871 	}
872 
873 	nfc_llcp_sock_put(llcp_sock);
874 }
875 
876 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
877 				  const struct sk_buff *skb)
878 {
879 	struct sock *new_sk, *parent;
880 	struct nfc_llcp_sock *sock, *new_sock;
881 	u8 dsap, ssap, reason;
882 
883 	dsap = nfc_llcp_dsap(skb);
884 	ssap = nfc_llcp_ssap(skb);
885 
886 	pr_debug("%d %d\n", dsap, ssap);
887 
888 	if (dsap != LLCP_SAP_SDP) {
889 		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
890 		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
891 			reason = LLCP_DM_NOBOUND;
892 			goto fail;
893 		}
894 	} else {
895 		const u8 *sn;
896 		size_t sn_len;
897 
898 		sn = nfc_llcp_connect_sn(skb, &sn_len);
899 		if (sn == NULL) {
900 			reason = LLCP_DM_NOBOUND;
901 			goto fail;
902 		}
903 
904 		pr_debug("Service name length %zu\n", sn_len);
905 
906 		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
907 		if (sock == NULL) {
908 			reason = LLCP_DM_NOBOUND;
909 			goto fail;
910 		}
911 	}
912 
913 	lock_sock(&sock->sk);
914 
915 	parent = &sock->sk;
916 
917 	if (sk_acceptq_is_full(parent)) {
918 		reason = LLCP_DM_REJ;
919 		release_sock(&sock->sk);
920 		sock_put(&sock->sk);
921 		goto fail;
922 	}
923 
924 	if (sock->ssap == LLCP_SDP_UNBOUND) {
925 		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
926 
927 		pr_debug("First client, reserving %d\n", ssap);
928 
929 		if (ssap == LLCP_SAP_MAX) {
930 			reason = LLCP_DM_REJ;
931 			release_sock(&sock->sk);
932 			sock_put(&sock->sk);
933 			goto fail;
934 		}
935 
936 		sock->ssap = ssap;
937 	}
938 
939 	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
940 	if (new_sk == NULL) {
941 		reason = LLCP_DM_REJ;
942 		release_sock(&sock->sk);
943 		sock_put(&sock->sk);
944 		goto fail;
945 	}
946 
947 	new_sock = nfc_llcp_sock(new_sk);
948 	new_sock->dev = local->dev;
949 	new_sock->local = nfc_llcp_local_get(local);
950 	new_sock->rw = sock->rw;
951 	new_sock->miux = sock->miux;
952 	new_sock->nfc_protocol = sock->nfc_protocol;
953 	new_sock->dsap = ssap;
954 	new_sock->target_idx = local->target_idx;
955 	new_sock->parent = parent;
956 	new_sock->ssap = sock->ssap;
957 	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
958 		atomic_t *client_count;
959 
960 		pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
961 
962 		client_count =
963 			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
964 
965 		atomic_inc(client_count);
966 		new_sock->reserved_ssap = sock->ssap;
967 	}
968 
969 	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
970 				      skb->len - LLCP_HEADER_SIZE);
971 
972 	pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
973 
974 	nfc_llcp_sock_link(&local->sockets, new_sk);
975 
976 	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
977 
978 	nfc_get_device(local->dev->idx);
979 
980 	new_sk->sk_state = LLCP_CONNECTED;
981 
982 	/* Wake the listening processes */
983 	parent->sk_data_ready(parent);
984 
985 	/* Send CC */
986 	nfc_llcp_send_cc(new_sock);
987 
988 	release_sock(&sock->sk);
989 	sock_put(&sock->sk);
990 
991 	return;
992 
993 fail:
994 	/* Send DM */
995 	nfc_llcp_send_dm(local, dsap, ssap, reason);
996 }
997 
998 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
999 {
1000 	int nr_frames = 0;
1001 	struct nfc_llcp_local *local = sock->local;
1002 
1003 	pr_debug("Remote ready %d tx queue len %d remote rw %d",
1004 		 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
1005 		 sock->remote_rw);
1006 
1007 	/* Try to queue some I frames for transmission */
1008 	while (sock->remote_ready &&
1009 	       skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {
1010 		struct sk_buff *pdu;
1011 
1012 		pdu = skb_dequeue(&sock->tx_queue);
1013 		if (pdu == NULL)
1014 			break;
1015 
1016 		/* Update N(S)/N(R) */
1017 		nfc_llcp_set_nrns(sock, pdu);
1018 
1019 		skb_queue_tail(&local->tx_queue, pdu);
1020 		nr_frames++;
1021 	}
1022 
1023 	return nr_frames;
1024 }
1025 
1026 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
1027 			       struct sk_buff *skb)
1028 {
1029 	struct nfc_llcp_sock *llcp_sock;
1030 	struct sock *sk;
1031 	u8 dsap, ssap, ptype, ns, nr;
1032 
1033 	ptype = nfc_llcp_ptype(skb);
1034 	dsap = nfc_llcp_dsap(skb);
1035 	ssap = nfc_llcp_ssap(skb);
1036 	ns = nfc_llcp_ns(skb);
1037 	nr = nfc_llcp_nr(skb);
1038 
1039 	pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
1040 
1041 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1042 	if (llcp_sock == NULL) {
1043 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1044 		return;
1045 	}
1046 
1047 	sk = &llcp_sock->sk;
1048 	lock_sock(sk);
1049 	if (sk->sk_state == LLCP_CLOSED) {
1050 		release_sock(sk);
1051 		nfc_llcp_sock_put(llcp_sock);
1052 	}
1053 
1054 	/* Pass the payload upstream */
1055 	if (ptype == LLCP_PDU_I) {
1056 		pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
1057 
1058 		if (ns == llcp_sock->recv_n)
1059 			llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
1060 		else
1061 			pr_err("Received out of sequence I PDU\n");
1062 
1063 		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
1064 		if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
1065 			/*
1066 			 * I frames will be freed from the socket layer, so we
1067 			 * need to keep them alive until someone receives them.
1068 			 */
1069 			skb_get(skb);
1070 		} else {
1071 			pr_err("Receive queue is full\n");
1072 		}
1073 	}
1074 
1075 	/* Remove skbs from the pending queue */
1076 	if (llcp_sock->send_ack_n != nr) {
1077 		struct sk_buff *s, *tmp;
1078 		u8 n;
1079 
1080 		llcp_sock->send_ack_n = nr;
1081 
1082 		/* Remove and free all skbs until ns == nr */
1083 		skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
1084 			n = nfc_llcp_ns(s);
1085 
1086 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1087 			kfree_skb(s);
1088 
1089 			if (n == nr)
1090 				break;
1091 		}
1092 
1093 		/* Re-queue the remaining skbs for transmission */
1094 		skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1095 					    s, tmp) {
1096 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1097 			skb_queue_head(&local->tx_queue, s);
1098 		}
1099 	}
1100 
1101 	if (ptype == LLCP_PDU_RR)
1102 		llcp_sock->remote_ready = true;
1103 	else if (ptype == LLCP_PDU_RNR)
1104 		llcp_sock->remote_ready = false;
1105 
1106 	if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1107 		nfc_llcp_send_rr(llcp_sock);
1108 
1109 	release_sock(sk);
1110 	nfc_llcp_sock_put(llcp_sock);
1111 }
1112 
1113 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1114 			       const struct sk_buff *skb)
1115 {
1116 	struct nfc_llcp_sock *llcp_sock;
1117 	struct sock *sk;
1118 	u8 dsap, ssap;
1119 
1120 	dsap = nfc_llcp_dsap(skb);
1121 	ssap = nfc_llcp_ssap(skb);
1122 
1123 	if ((dsap == 0) && (ssap == 0)) {
1124 		pr_debug("Connection termination");
1125 		nfc_dep_link_down(local->dev);
1126 		return;
1127 	}
1128 
1129 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1130 	if (llcp_sock == NULL) {
1131 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1132 		return;
1133 	}
1134 
1135 	sk = &llcp_sock->sk;
1136 	lock_sock(sk);
1137 
1138 	nfc_llcp_socket_purge(llcp_sock);
1139 
1140 	if (sk->sk_state == LLCP_CLOSED) {
1141 		release_sock(sk);
1142 		nfc_llcp_sock_put(llcp_sock);
1143 	}
1144 
1145 	if (sk->sk_state == LLCP_CONNECTED) {
1146 		nfc_put_device(local->dev);
1147 		sk->sk_state = LLCP_CLOSED;
1148 		sk->sk_state_change(sk);
1149 	}
1150 
1151 	nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1152 
1153 	release_sock(sk);
1154 	nfc_llcp_sock_put(llcp_sock);
1155 }
1156 
1157 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local,
1158 			     const struct sk_buff *skb)
1159 {
1160 	struct nfc_llcp_sock *llcp_sock;
1161 	struct sock *sk;
1162 	u8 dsap, ssap;
1163 
1164 	dsap = nfc_llcp_dsap(skb);
1165 	ssap = nfc_llcp_ssap(skb);
1166 
1167 	llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1168 	if (llcp_sock == NULL) {
1169 		pr_err("Invalid CC\n");
1170 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1171 
1172 		return;
1173 	}
1174 
1175 	sk = &llcp_sock->sk;
1176 
1177 	/* Unlink from connecting and link to the client array */
1178 	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1179 	nfc_llcp_sock_link(&local->sockets, sk);
1180 	llcp_sock->dsap = ssap;
1181 
1182 	nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1183 				      skb->len - LLCP_HEADER_SIZE);
1184 
1185 	sk->sk_state = LLCP_CONNECTED;
1186 	sk->sk_state_change(sk);
1187 
1188 	nfc_llcp_sock_put(llcp_sock);
1189 }
1190 
1191 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local,
1192 			     const struct sk_buff *skb)
1193 {
1194 	struct nfc_llcp_sock *llcp_sock;
1195 	struct sock *sk;
1196 	u8 dsap, ssap, reason;
1197 
1198 	dsap = nfc_llcp_dsap(skb);
1199 	ssap = nfc_llcp_ssap(skb);
1200 	reason = skb->data[2];
1201 
1202 	pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1203 
1204 	switch (reason) {
1205 	case LLCP_DM_NOBOUND:
1206 	case LLCP_DM_REJ:
1207 		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1208 		break;
1209 
1210 	default:
1211 		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1212 		break;
1213 	}
1214 
1215 	if (llcp_sock == NULL) {
1216 		pr_debug("Already closed\n");
1217 		return;
1218 	}
1219 
1220 	sk = &llcp_sock->sk;
1221 
1222 	sk->sk_err = ENXIO;
1223 	sk->sk_state = LLCP_CLOSED;
1224 	sk->sk_state_change(sk);
1225 
1226 	nfc_llcp_sock_put(llcp_sock);
1227 }
1228 
1229 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1230 			      const struct sk_buff *skb)
1231 {
1232 	struct nfc_llcp_sock *llcp_sock;
1233 	u8 dsap, ssap, type, length, tid, sap;
1234 	const u8 *tlv;
1235 	u16 tlv_len, offset;
1236 	const char *service_name;
1237 	size_t service_name_len;
1238 	struct nfc_llcp_sdp_tlv *sdp;
1239 	HLIST_HEAD(llc_sdres_list);
1240 	size_t sdres_tlvs_len;
1241 	HLIST_HEAD(nl_sdres_list);
1242 
1243 	dsap = nfc_llcp_dsap(skb);
1244 	ssap = nfc_llcp_ssap(skb);
1245 
1246 	pr_debug("%d %d\n", dsap, ssap);
1247 
1248 	if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1249 		pr_err("Wrong SNL SAP\n");
1250 		return;
1251 	}
1252 
1253 	tlv = &skb->data[LLCP_HEADER_SIZE];
1254 	tlv_len = skb->len - LLCP_HEADER_SIZE;
1255 	offset = 0;
1256 	sdres_tlvs_len = 0;
1257 
1258 	while (offset < tlv_len) {
1259 		type = tlv[0];
1260 		length = tlv[1];
1261 
1262 		switch (type) {
1263 		case LLCP_TLV_SDREQ:
1264 			tid = tlv[2];
1265 			service_name = (char *) &tlv[3];
1266 			service_name_len = length - 1;
1267 
1268 			pr_debug("Looking for %.16s\n", service_name);
1269 
1270 			if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1271 			    !strncmp(service_name, "urn:nfc:sn:sdp",
1272 				     service_name_len)) {
1273 				sap = 1;
1274 				goto add_snl;
1275 			}
1276 
1277 			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1278 							  service_name_len);
1279 			if (!llcp_sock) {
1280 				sap = 0;
1281 				goto add_snl;
1282 			}
1283 
1284 			/*
1285 			 * We found a socket but its ssap has not been reserved
1286 			 * yet. We need to assign it for good and send a reply.
1287 			 * The ssap will be freed when the socket is closed.
1288 			 */
1289 			if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1290 				atomic_t *client_count;
1291 
1292 				sap = nfc_llcp_reserve_sdp_ssap(local);
1293 
1294 				pr_debug("Reserving %d\n", sap);
1295 
1296 				if (sap == LLCP_SAP_MAX) {
1297 					sap = 0;
1298 					goto add_snl;
1299 				}
1300 
1301 				client_count =
1302 					&local->local_sdp_cnt[sap -
1303 							      LLCP_WKS_NUM_SAP];
1304 
1305 				atomic_inc(client_count);
1306 
1307 				llcp_sock->ssap = sap;
1308 				llcp_sock->reserved_ssap = sap;
1309 			} else {
1310 				sap = llcp_sock->ssap;
1311 			}
1312 
1313 			pr_debug("%p %d\n", llcp_sock, sap);
1314 
1315 add_snl:
1316 			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
1317 			if (sdp == NULL)
1318 				goto exit;
1319 
1320 			sdres_tlvs_len += sdp->tlv_len;
1321 			hlist_add_head(&sdp->node, &llc_sdres_list);
1322 			break;
1323 
1324 		case LLCP_TLV_SDRES:
1325 			mutex_lock(&local->sdreq_lock);
1326 
1327 			pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]);
1328 
1329 			hlist_for_each_entry(sdp, &local->pending_sdreqs, node) {
1330 				if (sdp->tid != tlv[2])
1331 					continue;
1332 
1333 				sdp->sap = tlv[3];
1334 
1335 				pr_debug("Found: uri=%s, sap=%d\n",
1336 					 sdp->uri, sdp->sap);
1337 
1338 				hlist_del(&sdp->node);
1339 
1340 				hlist_add_head(&sdp->node, &nl_sdres_list);
1341 
1342 				break;
1343 			}
1344 
1345 			mutex_unlock(&local->sdreq_lock);
1346 			break;
1347 
1348 		default:
1349 			pr_err("Invalid SNL tlv value 0x%x\n", type);
1350 			break;
1351 		}
1352 
1353 		offset += length + 2;
1354 		tlv += length + 2;
1355 	}
1356 
1357 exit:
1358 	if (!hlist_empty(&nl_sdres_list))
1359 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
1360 
1361 	if (!hlist_empty(&llc_sdres_list))
1362 		nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);
1363 }
1364 
1365 static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
1366 {
1367 	u8 ptype;
1368 	u16 pdu_len;
1369 	struct sk_buff *new_skb;
1370 
1371 	if (skb->len <= LLCP_HEADER_SIZE) {
1372 		pr_err("Malformed AGF PDU\n");
1373 		return;
1374 	}
1375 
1376 	skb_pull(skb, LLCP_HEADER_SIZE);
1377 
1378 	while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) {
1379 		pdu_len = skb->data[0] << 8 | skb->data[1];
1380 
1381 		skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE);
1382 
1383 		if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) {
1384 			pr_err("Malformed AGF PDU\n");
1385 			return;
1386 		}
1387 
1388 		ptype = nfc_llcp_ptype(skb);
1389 
1390 		if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF)
1391 			goto next;
1392 
1393 		new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
1394 		if (new_skb == NULL) {
1395 			pr_err("Could not allocate PDU\n");
1396 			return;
1397 		}
1398 
1399 		skb_put_data(new_skb, skb->data, pdu_len);
1400 
1401 		nfc_llcp_rx_skb(local, new_skb);
1402 
1403 		kfree_skb(new_skb);
1404 next:
1405 		skb_pull(skb, pdu_len);
1406 	}
1407 }
1408 
1409 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
1410 {
1411 	u8 dsap, ssap, ptype;
1412 
1413 	ptype = nfc_llcp_ptype(skb);
1414 	dsap = nfc_llcp_dsap(skb);
1415 	ssap = nfc_llcp_ssap(skb);
1416 
1417 	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1418 
1419 	if (ptype != LLCP_PDU_SYMM)
1420 		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
1421 				     skb->data, skb->len, true);
1422 
1423 	switch (ptype) {
1424 	case LLCP_PDU_SYMM:
1425 		pr_debug("SYMM\n");
1426 		break;
1427 
1428 	case LLCP_PDU_UI:
1429 		pr_debug("UI\n");
1430 		nfc_llcp_recv_ui(local, skb);
1431 		break;
1432 
1433 	case LLCP_PDU_CONNECT:
1434 		pr_debug("CONNECT\n");
1435 		nfc_llcp_recv_connect(local, skb);
1436 		break;
1437 
1438 	case LLCP_PDU_DISC:
1439 		pr_debug("DISC\n");
1440 		nfc_llcp_recv_disc(local, skb);
1441 		break;
1442 
1443 	case LLCP_PDU_CC:
1444 		pr_debug("CC\n");
1445 		nfc_llcp_recv_cc(local, skb);
1446 		break;
1447 
1448 	case LLCP_PDU_DM:
1449 		pr_debug("DM\n");
1450 		nfc_llcp_recv_dm(local, skb);
1451 		break;
1452 
1453 	case LLCP_PDU_SNL:
1454 		pr_debug("SNL\n");
1455 		nfc_llcp_recv_snl(local, skb);
1456 		break;
1457 
1458 	case LLCP_PDU_I:
1459 	case LLCP_PDU_RR:
1460 	case LLCP_PDU_RNR:
1461 		pr_debug("I frame\n");
1462 		nfc_llcp_recv_hdlc(local, skb);
1463 		break;
1464 
1465 	case LLCP_PDU_AGF:
1466 		pr_debug("AGF frame\n");
1467 		nfc_llcp_recv_agf(local, skb);
1468 		break;
1469 	}
1470 }
1471 
1472 static void nfc_llcp_rx_work(struct work_struct *work)
1473 {
1474 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1475 						    rx_work);
1476 	struct sk_buff *skb;
1477 
1478 	skb = local->rx_pending;
1479 	if (skb == NULL) {
1480 		pr_debug("No pending SKB\n");
1481 		return;
1482 	}
1483 
1484 	__net_timestamp(skb);
1485 
1486 	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);
1487 
1488 	nfc_llcp_rx_skb(local, skb);
1489 
1490 	schedule_work(&local->tx_work);
1491 	kfree_skb(local->rx_pending);
1492 	local->rx_pending = NULL;
1493 }
1494 
1495 static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
1496 {
1497 	local->rx_pending = skb;
1498 	del_timer(&local->link_timer);
1499 	schedule_work(&local->rx_work);
1500 }
1501 
1502 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1503 {
1504 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1505 
1506 	if (err < 0) {
1507 		pr_err("LLCP PDU receive err %d\n", err);
1508 		return;
1509 	}
1510 
1511 	__nfc_llcp_recv(local, skb);
1512 }
1513 
1514 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1515 {
1516 	struct nfc_llcp_local *local;
1517 
1518 	local = nfc_llcp_find_local(dev);
1519 	if (local == NULL) {
1520 		kfree_skb(skb);
1521 		return -ENODEV;
1522 	}
1523 
1524 	__nfc_llcp_recv(local, skb);
1525 
1526 	return 0;
1527 }
1528 
1529 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1530 {
1531 	struct nfc_llcp_local *local;
1532 
1533 	local = nfc_llcp_find_local(dev);
1534 	if (local == NULL)
1535 		return;
1536 
1537 	local->remote_miu = LLCP_DEFAULT_MIU;
1538 	local->remote_lto = LLCP_DEFAULT_LTO;
1539 
1540 	/* Close and purge all existing sockets */
1541 	nfc_llcp_socket_release(local, true, 0);
1542 }
1543 
1544 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1545 			u8 comm_mode, u8 rf_mode)
1546 {
1547 	struct nfc_llcp_local *local;
1548 
1549 	pr_debug("rf mode %d\n", rf_mode);
1550 
1551 	local = nfc_llcp_find_local(dev);
1552 	if (local == NULL)
1553 		return;
1554 
1555 	local->target_idx = target_idx;
1556 	local->comm_mode = comm_mode;
1557 	local->rf_mode = rf_mode;
1558 
1559 	if (rf_mode == NFC_RF_INITIATOR) {
1560 		pr_debug("Queueing Tx work\n");
1561 
1562 		schedule_work(&local->tx_work);
1563 	} else {
1564 		mod_timer(&local->link_timer,
1565 			  jiffies + msecs_to_jiffies(local->remote_lto));
1566 	}
1567 }
1568 
1569 int nfc_llcp_register_device(struct nfc_dev *ndev)
1570 {
1571 	struct nfc_llcp_local *local;
1572 
1573 	local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1574 	if (local == NULL)
1575 		return -ENOMEM;
1576 
1577 	local->dev = ndev;
1578 	INIT_LIST_HEAD(&local->list);
1579 	kref_init(&local->ref);
1580 	mutex_init(&local->sdp_lock);
1581 	timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0);
1582 
1583 	skb_queue_head_init(&local->tx_queue);
1584 	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1585 
1586 	local->rx_pending = NULL;
1587 	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1588 
1589 	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1590 
1591 	rwlock_init(&local->sockets.lock);
1592 	rwlock_init(&local->connecting_sockets.lock);
1593 	rwlock_init(&local->raw_sockets.lock);
1594 
1595 	local->lto = 150; /* 1500 ms */
1596 	local->rw = LLCP_MAX_RW;
1597 	local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1598 	local->local_wks = 0x1; /* LLC Link Management */
1599 
1600 	nfc_llcp_build_gb(local);
1601 
1602 	local->remote_miu = LLCP_DEFAULT_MIU;
1603 	local->remote_lto = LLCP_DEFAULT_LTO;
1604 
1605 	mutex_init(&local->sdreq_lock);
1606 	INIT_HLIST_HEAD(&local->pending_sdreqs);
1607 	timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0);
1608 	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
1609 
1610 	list_add(&local->list, &llcp_devices);
1611 
1612 	return 0;
1613 }
1614 
1615 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1616 {
1617 	struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
1618 
1619 	if (local == NULL) {
1620 		pr_debug("No such device\n");
1621 		return;
1622 	}
1623 
1624 	local_cleanup(local);
1625 
1626 	nfc_llcp_local_put(local);
1627 }
1628 
1629 int __init nfc_llcp_init(void)
1630 {
1631 	return nfc_llcp_sock_init();
1632 }
1633 
1634 void nfc_llcp_exit(void)
1635 {
1636 	nfc_llcp_sock_exit();
1637 }
1638