xref: /linux/net/nfc/llcp_core.c (revision cbe0e415089636170aa6eb540ca4af5dc9842a60)
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 /* Protects llcp_devices list */
21 static DEFINE_SPINLOCK(llcp_devices_lock);
22 
23 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb);
24 
25 void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)
26 {
27 	write_lock(&l->lock);
28 	sk_add_node(sk, &l->head);
29 	write_unlock(&l->lock);
30 }
31 
32 void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
33 {
34 	write_lock(&l->lock);
35 	sk_del_node_init(sk);
36 	write_unlock(&l->lock);
37 }
38 
39 void nfc_llcp_socket_remote_param_init(struct nfc_llcp_sock *sock)
40 {
41 	sock->remote_rw = LLCP_DEFAULT_RW;
42 	sock->remote_miu = LLCP_MAX_MIU + 1;
43 }
44 
45 static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock)
46 {
47 	struct nfc_llcp_local *local = sock->local;
48 	struct sk_buff *s, *tmp;
49 
50 	skb_queue_purge(&sock->tx_queue);
51 	skb_queue_purge(&sock->tx_pending_queue);
52 
53 	if (local == NULL)
54 		return;
55 
56 	/* Search for local pending SKBs that are related to this socket */
57 	skb_queue_walk_safe(&local->tx_queue, s, tmp) {
58 		if (s->sk != &sock->sk)
59 			continue;
60 
61 		skb_unlink(s, &local->tx_queue);
62 		kfree_skb(s);
63 	}
64 }
65 
66 static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device,
67 				    int err)
68 {
69 	struct sock *sk;
70 	struct hlist_node *tmp;
71 	struct nfc_llcp_sock *llcp_sock;
72 
73 	skb_queue_purge(&local->tx_queue);
74 
75 	write_lock(&local->sockets.lock);
76 
77 	sk_for_each_safe(sk, tmp, &local->sockets.head) {
78 		llcp_sock = nfc_llcp_sock(sk);
79 
80 		bh_lock_sock(sk);
81 
82 		nfc_llcp_socket_purge(llcp_sock);
83 
84 		if (sk->sk_state == LLCP_CONNECTED)
85 			nfc_put_device(llcp_sock->dev);
86 
87 		if (sk->sk_state == LLCP_LISTEN) {
88 			struct nfc_llcp_sock *lsk, *n;
89 			struct sock *accept_sk;
90 
91 			list_for_each_entry_safe(lsk, n,
92 						 &llcp_sock->accept_queue,
93 						 accept_queue) {
94 				accept_sk = &lsk->sk;
95 				bh_lock_sock(accept_sk);
96 
97 				nfc_llcp_accept_unlink(accept_sk);
98 
99 				if (err)
100 					accept_sk->sk_err = err;
101 				accept_sk->sk_state = LLCP_CLOSED;
102 				accept_sk->sk_state_change(sk);
103 
104 				bh_unlock_sock(accept_sk);
105 			}
106 		}
107 
108 		if (err)
109 			sk->sk_err = err;
110 		sk->sk_state = LLCP_CLOSED;
111 		sk->sk_state_change(sk);
112 
113 		bh_unlock_sock(sk);
114 
115 		sk_del_node_init(sk);
116 	}
117 
118 	write_unlock(&local->sockets.lock);
119 
120 	/* If we still have a device, we keep the RAW sockets alive */
121 	if (device == true)
122 		return;
123 
124 	write_lock(&local->raw_sockets.lock);
125 
126 	sk_for_each_safe(sk, tmp, &local->raw_sockets.head) {
127 		llcp_sock = nfc_llcp_sock(sk);
128 
129 		bh_lock_sock(sk);
130 
131 		nfc_llcp_socket_purge(llcp_sock);
132 
133 		if (err)
134 			sk->sk_err = err;
135 		sk->sk_state = LLCP_CLOSED;
136 		sk->sk_state_change(sk);
137 
138 		bh_unlock_sock(sk);
139 
140 		sk_del_node_init(sk);
141 	}
142 
143 	write_unlock(&local->raw_sockets.lock);
144 }
145 
146 static struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
147 {
148 	kref_get(&local->ref);
149 
150 	return local;
151 }
152 
153 static void local_cleanup(struct nfc_llcp_local *local)
154 {
155 	nfc_llcp_socket_release(local, false, ENXIO);
156 	del_timer_sync(&local->link_timer);
157 	skb_queue_purge(&local->tx_queue);
158 	cancel_work_sync(&local->tx_work);
159 	cancel_work_sync(&local->rx_work);
160 	cancel_work_sync(&local->timeout_work);
161 	kfree_skb(local->rx_pending);
162 	local->rx_pending = NULL;
163 	del_timer_sync(&local->sdreq_timer);
164 	cancel_work_sync(&local->sdreq_timeout_work);
165 	nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);
166 }
167 
168 static void local_release(struct kref *ref)
169 {
170 	struct nfc_llcp_local *local;
171 
172 	local = container_of(ref, struct nfc_llcp_local, ref);
173 
174 	local_cleanup(local);
175 	kfree(local);
176 }
177 
178 int nfc_llcp_local_put(struct nfc_llcp_local *local)
179 {
180 	if (local == NULL)
181 		return 0;
182 
183 	return kref_put(&local->ref, local_release);
184 }
185 
186 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
187 					       u8 ssap, u8 dsap)
188 {
189 	struct sock *sk;
190 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
191 
192 	pr_debug("ssap dsap %d %d\n", ssap, dsap);
193 
194 	if (ssap == 0 && dsap == 0)
195 		return NULL;
196 
197 	read_lock(&local->sockets.lock);
198 
199 	llcp_sock = NULL;
200 
201 	sk_for_each(sk, &local->sockets.head) {
202 		tmp_sock = nfc_llcp_sock(sk);
203 
204 		if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
205 			llcp_sock = tmp_sock;
206 			sock_hold(&llcp_sock->sk);
207 			break;
208 		}
209 	}
210 
211 	read_unlock(&local->sockets.lock);
212 
213 	return llcp_sock;
214 }
215 
216 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
217 {
218 	sock_put(&sock->sk);
219 }
220 
221 static void nfc_llcp_timeout_work(struct work_struct *work)
222 {
223 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
224 						    timeout_work);
225 
226 	nfc_dep_link_down(local->dev);
227 }
228 
229 static void nfc_llcp_symm_timer(struct timer_list *t)
230 {
231 	struct nfc_llcp_local *local = from_timer(local, t, link_timer);
232 
233 	pr_err("SYMM timeout\n");
234 
235 	schedule_work(&local->timeout_work);
236 }
237 
238 static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
239 {
240 	unsigned long time;
241 	HLIST_HEAD(nl_sdres_list);
242 	struct hlist_node *n;
243 	struct nfc_llcp_sdp_tlv *sdp;
244 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
245 						    sdreq_timeout_work);
246 
247 	mutex_lock(&local->sdreq_lock);
248 
249 	time = jiffies - msecs_to_jiffies(3 * local->remote_lto);
250 
251 	hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) {
252 		if (time_after(sdp->time, time))
253 			continue;
254 
255 		sdp->sap = LLCP_SDP_UNBOUND;
256 
257 		hlist_del(&sdp->node);
258 
259 		hlist_add_head(&sdp->node, &nl_sdres_list);
260 	}
261 
262 	if (!hlist_empty(&local->pending_sdreqs))
263 		mod_timer(&local->sdreq_timer,
264 			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
265 
266 	mutex_unlock(&local->sdreq_lock);
267 
268 	if (!hlist_empty(&nl_sdres_list))
269 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
270 }
271 
272 static void nfc_llcp_sdreq_timer(struct timer_list *t)
273 {
274 	struct nfc_llcp_local *local = from_timer(local, t, sdreq_timer);
275 
276 	schedule_work(&local->sdreq_timeout_work);
277 }
278 
279 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
280 {
281 	struct nfc_llcp_local *local;
282 	struct nfc_llcp_local *res = NULL;
283 
284 	spin_lock(&llcp_devices_lock);
285 	list_for_each_entry(local, &llcp_devices, list)
286 		if (local->dev == dev) {
287 			res = nfc_llcp_local_get(local);
288 			break;
289 		}
290 	spin_unlock(&llcp_devices_lock);
291 
292 	return res;
293 }
294 
295 static struct nfc_llcp_local *nfc_llcp_remove_local(struct nfc_dev *dev)
296 {
297 	struct nfc_llcp_local *local, *tmp;
298 
299 	spin_lock(&llcp_devices_lock);
300 	list_for_each_entry_safe(local, tmp, &llcp_devices, list)
301 		if (local->dev == dev) {
302 			list_del(&local->list);
303 			spin_unlock(&llcp_devices_lock);
304 			return local;
305 		}
306 	spin_unlock(&llcp_devices_lock);
307 
308 	pr_warn("Shutting down device not found\n");
309 
310 	return NULL;
311 }
312 
313 static char *wks[] = {
314 	NULL,
315 	NULL, /* SDP */
316 	"urn:nfc:sn:ip",
317 	"urn:nfc:sn:obex",
318 	"urn:nfc:sn:snep",
319 };
320 
321 static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len)
322 {
323 	int sap, num_wks;
324 
325 	pr_debug("%s\n", service_name);
326 
327 	if (service_name == NULL)
328 		return -EINVAL;
329 
330 	num_wks = ARRAY_SIZE(wks);
331 
332 	for (sap = 0; sap < num_wks; sap++) {
333 		if (wks[sap] == NULL)
334 			continue;
335 
336 		if (strncmp(wks[sap], service_name, service_name_len) == 0)
337 			return sap;
338 	}
339 
340 	return -EINVAL;
341 }
342 
343 static
344 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
345 					    const u8 *sn, size_t sn_len,
346 					    bool needref)
347 {
348 	struct sock *sk;
349 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
350 
351 	pr_debug("sn %zd %p\n", sn_len, sn);
352 
353 	if (sn == NULL || sn_len == 0)
354 		return NULL;
355 
356 	read_lock(&local->sockets.lock);
357 
358 	llcp_sock = NULL;
359 
360 	sk_for_each(sk, &local->sockets.head) {
361 		tmp_sock = nfc_llcp_sock(sk);
362 
363 		pr_debug("llcp sock %p\n", tmp_sock);
364 
365 		if (tmp_sock->sk.sk_type == SOCK_STREAM &&
366 		    tmp_sock->sk.sk_state != LLCP_LISTEN)
367 			continue;
368 
369 		if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
370 		    tmp_sock->sk.sk_state != LLCP_BOUND)
371 			continue;
372 
373 		if (tmp_sock->service_name == NULL ||
374 		    tmp_sock->service_name_len == 0)
375 			continue;
376 
377 		if (tmp_sock->service_name_len != sn_len)
378 			continue;
379 
380 		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
381 			llcp_sock = tmp_sock;
382 			if (needref)
383 				sock_hold(&llcp_sock->sk);
384 			break;
385 		}
386 	}
387 
388 	read_unlock(&local->sockets.lock);
389 
390 	pr_debug("Found llcp sock %p\n", llcp_sock);
391 
392 	return llcp_sock;
393 }
394 
395 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
396 			 struct nfc_llcp_sock *sock)
397 {
398 	mutex_lock(&local->sdp_lock);
399 
400 	if (sock->service_name != NULL && sock->service_name_len > 0) {
401 		int ssap = nfc_llcp_wks_sap(sock->service_name,
402 					    sock->service_name_len);
403 
404 		if (ssap > 0) {
405 			pr_debug("WKS %d\n", ssap);
406 
407 			/* This is a WKS, let's check if it's free */
408 			if (test_bit(ssap, &local->local_wks)) {
409 				mutex_unlock(&local->sdp_lock);
410 
411 				return LLCP_SAP_MAX;
412 			}
413 
414 			set_bit(ssap, &local->local_wks);
415 			mutex_unlock(&local->sdp_lock);
416 
417 			return ssap;
418 		}
419 
420 		/*
421 		 * Check if there already is a non WKS socket bound
422 		 * to this service name.
423 		 */
424 		if (nfc_llcp_sock_from_sn(local, sock->service_name,
425 					  sock->service_name_len,
426 					  false) != NULL) {
427 			mutex_unlock(&local->sdp_lock);
428 
429 			return LLCP_SAP_MAX;
430 		}
431 
432 		mutex_unlock(&local->sdp_lock);
433 
434 		return LLCP_SDP_UNBOUND;
435 
436 	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
437 		if (!test_bit(sock->ssap, &local->local_wks)) {
438 			set_bit(sock->ssap, &local->local_wks);
439 			mutex_unlock(&local->sdp_lock);
440 
441 			return sock->ssap;
442 		}
443 	}
444 
445 	mutex_unlock(&local->sdp_lock);
446 
447 	return LLCP_SAP_MAX;
448 }
449 
450 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
451 {
452 	u8 local_ssap;
453 
454 	mutex_lock(&local->sdp_lock);
455 
456 	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
457 	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
458 		mutex_unlock(&local->sdp_lock);
459 		return LLCP_SAP_MAX;
460 	}
461 
462 	set_bit(local_ssap, &local->local_sap);
463 
464 	mutex_unlock(&local->sdp_lock);
465 
466 	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
467 }
468 
469 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
470 {
471 	u8 local_ssap;
472 	unsigned long *sdp;
473 
474 	if (ssap < LLCP_WKS_NUM_SAP) {
475 		local_ssap = ssap;
476 		sdp = &local->local_wks;
477 	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
478 		atomic_t *client_cnt;
479 
480 		local_ssap = ssap - LLCP_WKS_NUM_SAP;
481 		sdp = &local->local_sdp;
482 		client_cnt = &local->local_sdp_cnt[local_ssap];
483 
484 		pr_debug("%d clients\n", atomic_read(client_cnt));
485 
486 		mutex_lock(&local->sdp_lock);
487 
488 		if (atomic_dec_and_test(client_cnt)) {
489 			struct nfc_llcp_sock *l_sock;
490 
491 			pr_debug("No more clients for SAP %d\n", ssap);
492 
493 			clear_bit(local_ssap, sdp);
494 
495 			/* Find the listening sock and set it back to UNBOUND */
496 			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
497 			if (l_sock) {
498 				l_sock->ssap = LLCP_SDP_UNBOUND;
499 				nfc_llcp_sock_put(l_sock);
500 			}
501 		}
502 
503 		mutex_unlock(&local->sdp_lock);
504 
505 		return;
506 	} else if (ssap < LLCP_MAX_SAP) {
507 		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
508 		sdp = &local->local_sap;
509 	} else {
510 		return;
511 	}
512 
513 	mutex_lock(&local->sdp_lock);
514 
515 	clear_bit(local_ssap, sdp);
516 
517 	mutex_unlock(&local->sdp_lock);
518 }
519 
520 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
521 {
522 	u8 ssap;
523 
524 	mutex_lock(&local->sdp_lock);
525 
526 	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
527 	if (ssap == LLCP_SDP_NUM_SAP) {
528 		mutex_unlock(&local->sdp_lock);
529 
530 		return LLCP_SAP_MAX;
531 	}
532 
533 	pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
534 
535 	set_bit(ssap, &local->local_sdp);
536 
537 	mutex_unlock(&local->sdp_lock);
538 
539 	return LLCP_WKS_NUM_SAP + ssap;
540 }
541 
542 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
543 {
544 	u8 *gb_cur, version, version_length;
545 	u8 lto_length, wks_length, miux_length;
546 	const u8 *version_tlv = NULL, *lto_tlv = NULL,
547 	   *wks_tlv = NULL, *miux_tlv = NULL;
548 	__be16 wks = cpu_to_be16(local->local_wks);
549 	u8 gb_len = 0;
550 	int ret = 0;
551 
552 	version = LLCP_VERSION_11;
553 	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
554 					 1, &version_length);
555 	if (!version_tlv) {
556 		ret = -ENOMEM;
557 		goto out;
558 	}
559 	gb_len += version_length;
560 
561 	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
562 	if (!lto_tlv) {
563 		ret = -ENOMEM;
564 		goto out;
565 	}
566 	gb_len += lto_length;
567 
568 	pr_debug("Local wks 0x%lx\n", local->local_wks);
569 	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
570 	if (!wks_tlv) {
571 		ret = -ENOMEM;
572 		goto out;
573 	}
574 	gb_len += wks_length;
575 
576 	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
577 				      &miux_length);
578 	if (!miux_tlv) {
579 		ret = -ENOMEM;
580 		goto out;
581 	}
582 	gb_len += miux_length;
583 
584 	gb_len += ARRAY_SIZE(llcp_magic);
585 
586 	if (gb_len > NFC_MAX_GT_LEN) {
587 		ret = -EINVAL;
588 		goto out;
589 	}
590 
591 	gb_cur = local->gb;
592 
593 	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
594 	gb_cur += ARRAY_SIZE(llcp_magic);
595 
596 	memcpy(gb_cur, version_tlv, version_length);
597 	gb_cur += version_length;
598 
599 	memcpy(gb_cur, lto_tlv, lto_length);
600 	gb_cur += lto_length;
601 
602 	memcpy(gb_cur, wks_tlv, wks_length);
603 	gb_cur += wks_length;
604 
605 	memcpy(gb_cur, miux_tlv, miux_length);
606 	gb_cur += miux_length;
607 
608 	local->gb_len = gb_len;
609 
610 out:
611 	kfree(version_tlv);
612 	kfree(lto_tlv);
613 	kfree(wks_tlv);
614 	kfree(miux_tlv);
615 
616 	return ret;
617 }
618 
619 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
620 {
621 	struct nfc_llcp_local *local;
622 
623 	local = nfc_llcp_find_local(dev);
624 	if (local == NULL) {
625 		*general_bytes_len = 0;
626 		return NULL;
627 	}
628 
629 	nfc_llcp_build_gb(local);
630 
631 	*general_bytes_len = local->gb_len;
632 
633 	nfc_llcp_local_put(local);
634 
635 	return local->gb;
636 }
637 
638 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, const u8 *gb, u8 gb_len)
639 {
640 	struct nfc_llcp_local *local;
641 	int err;
642 
643 	if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
644 		return -EINVAL;
645 
646 	local = nfc_llcp_find_local(dev);
647 	if (local == NULL) {
648 		pr_err("No LLCP device\n");
649 		return -ENODEV;
650 	}
651 
652 	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
653 	memcpy(local->remote_gb, gb, gb_len);
654 	local->remote_gb_len = gb_len;
655 
656 	if (memcmp(local->remote_gb, llcp_magic, 3)) {
657 		pr_err("MAC does not support LLCP\n");
658 		err = -EINVAL;
659 		goto out;
660 	}
661 
662 	err = nfc_llcp_parse_gb_tlv(local,
663 				     &local->remote_gb[3],
664 				     local->remote_gb_len - 3);
665 out:
666 	nfc_llcp_local_put(local);
667 	return err;
668 }
669 
670 static u8 nfc_llcp_dsap(const struct sk_buff *pdu)
671 {
672 	return (pdu->data[0] & 0xfc) >> 2;
673 }
674 
675 static u8 nfc_llcp_ptype(const struct sk_buff *pdu)
676 {
677 	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
678 }
679 
680 static u8 nfc_llcp_ssap(const struct sk_buff *pdu)
681 {
682 	return pdu->data[1] & 0x3f;
683 }
684 
685 static u8 nfc_llcp_ns(const struct sk_buff *pdu)
686 {
687 	return pdu->data[2] >> 4;
688 }
689 
690 static u8 nfc_llcp_nr(const struct sk_buff *pdu)
691 {
692 	return pdu->data[2] & 0xf;
693 }
694 
695 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
696 {
697 	pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
698 	sock->send_n = (sock->send_n + 1) % 16;
699 	sock->recv_ack_n = (sock->recv_n - 1) % 16;
700 }
701 
702 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
703 			       struct sk_buff *skb, u8 direction)
704 {
705 	struct sk_buff *skb_copy = NULL, *nskb;
706 	struct sock *sk;
707 	u8 *data;
708 
709 	read_lock(&local->raw_sockets.lock);
710 
711 	sk_for_each(sk, &local->raw_sockets.head) {
712 		if (sk->sk_state != LLCP_BOUND)
713 			continue;
714 
715 		if (skb_copy == NULL) {
716 			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
717 						      GFP_ATOMIC, true);
718 
719 			if (skb_copy == NULL)
720 				continue;
721 
722 			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
723 
724 			data[0] = local->dev ? local->dev->idx : 0xFF;
725 			data[1] = direction & 0x01;
726 			data[1] |= (RAW_PAYLOAD_LLCP << 1);
727 		}
728 
729 		nskb = skb_clone(skb_copy, GFP_ATOMIC);
730 		if (!nskb)
731 			continue;
732 
733 		if (sock_queue_rcv_skb(sk, nskb))
734 			kfree_skb(nskb);
735 	}
736 
737 	read_unlock(&local->raw_sockets.lock);
738 
739 	kfree_skb(skb_copy);
740 }
741 
742 static void nfc_llcp_tx_work(struct work_struct *work)
743 {
744 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
745 						    tx_work);
746 	struct sk_buff *skb;
747 	struct sock *sk;
748 	struct nfc_llcp_sock *llcp_sock;
749 
750 	skb = skb_dequeue(&local->tx_queue);
751 	if (skb != NULL) {
752 		sk = skb->sk;
753 		llcp_sock = nfc_llcp_sock(sk);
754 
755 		if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
756 			kfree_skb(skb);
757 			nfc_llcp_send_symm(local->dev);
758 		} else if (llcp_sock && !llcp_sock->remote_ready) {
759 			skb_queue_head(&local->tx_queue, skb);
760 			nfc_llcp_send_symm(local->dev);
761 		} else {
762 			struct sk_buff *copy_skb = NULL;
763 			u8 ptype = nfc_llcp_ptype(skb);
764 			int ret;
765 
766 			pr_debug("Sending pending skb\n");
767 			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
768 					     16, 1, skb->data, skb->len, true);
769 
770 			if (ptype == LLCP_PDU_I)
771 				copy_skb = skb_copy(skb, GFP_ATOMIC);
772 
773 			__net_timestamp(skb);
774 
775 			nfc_llcp_send_to_raw_sock(local, skb,
776 						  NFC_DIRECTION_TX);
777 
778 			ret = nfc_data_exchange(local->dev, local->target_idx,
779 						skb, nfc_llcp_recv, local);
780 
781 			if (ret) {
782 				kfree_skb(copy_skb);
783 				goto out;
784 			}
785 
786 			if (ptype == LLCP_PDU_I && copy_skb)
787 				skb_queue_tail(&llcp_sock->tx_pending_queue,
788 					       copy_skb);
789 		}
790 	} else {
791 		nfc_llcp_send_symm(local->dev);
792 	}
793 
794 out:
795 	mod_timer(&local->link_timer,
796 		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
797 }
798 
799 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
800 							  u8 ssap)
801 {
802 	struct sock *sk;
803 	struct nfc_llcp_sock *llcp_sock;
804 
805 	read_lock(&local->connecting_sockets.lock);
806 
807 	sk_for_each(sk, &local->connecting_sockets.head) {
808 		llcp_sock = nfc_llcp_sock(sk);
809 
810 		if (llcp_sock->ssap == ssap) {
811 			sock_hold(&llcp_sock->sk);
812 			goto out;
813 		}
814 	}
815 
816 	llcp_sock = NULL;
817 
818 out:
819 	read_unlock(&local->connecting_sockets.lock);
820 
821 	return llcp_sock;
822 }
823 
824 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
825 						  const u8 *sn, size_t sn_len)
826 {
827 	return nfc_llcp_sock_from_sn(local, sn, sn_len, true);
828 }
829 
830 static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
831 {
832 	u8 type, length;
833 	const u8 *tlv = &skb->data[2];
834 	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
835 
836 	while (offset < tlv_array_len) {
837 		type = tlv[0];
838 		length = tlv[1];
839 
840 		pr_debug("type 0x%x length %d\n", type, length);
841 
842 		if (type == LLCP_TLV_SN) {
843 			*sn_len = length;
844 			return &tlv[2];
845 		}
846 
847 		offset += length + 2;
848 		tlv += length + 2;
849 	}
850 
851 	return NULL;
852 }
853 
854 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
855 			     struct sk_buff *skb)
856 {
857 	struct nfc_llcp_sock *llcp_sock;
858 	struct nfc_llcp_ui_cb *ui_cb;
859 	u8 dsap, ssap;
860 
861 	dsap = nfc_llcp_dsap(skb);
862 	ssap = nfc_llcp_ssap(skb);
863 
864 	ui_cb = nfc_llcp_ui_skb_cb(skb);
865 	ui_cb->dsap = dsap;
866 	ui_cb->ssap = ssap;
867 
868 	pr_debug("%d %d\n", dsap, ssap);
869 
870 	/* We're looking for a bound socket, not a client one */
871 	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
872 	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
873 		return;
874 
875 	/* There is no sequence with UI frames */
876 	skb_pull(skb, LLCP_HEADER_SIZE);
877 	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
878 		/*
879 		 * UI frames will be freed from the socket layer, so we
880 		 * need to keep them alive until someone receives them.
881 		 */
882 		skb_get(skb);
883 	} else {
884 		pr_err("Receive queue is full\n");
885 	}
886 
887 	nfc_llcp_sock_put(llcp_sock);
888 }
889 
890 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
891 				  const struct sk_buff *skb)
892 {
893 	struct sock *new_sk, *parent;
894 	struct nfc_llcp_sock *sock, *new_sock;
895 	u8 dsap, ssap, reason;
896 
897 	dsap = nfc_llcp_dsap(skb);
898 	ssap = nfc_llcp_ssap(skb);
899 
900 	pr_debug("%d %d\n", dsap, ssap);
901 
902 	if (dsap != LLCP_SAP_SDP) {
903 		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
904 		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
905 			reason = LLCP_DM_NOBOUND;
906 			goto fail;
907 		}
908 	} else {
909 		const u8 *sn;
910 		size_t sn_len;
911 
912 		sn = nfc_llcp_connect_sn(skb, &sn_len);
913 		if (sn == NULL) {
914 			reason = LLCP_DM_NOBOUND;
915 			goto fail;
916 		}
917 
918 		pr_debug("Service name length %zu\n", sn_len);
919 
920 		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
921 		if (sock == NULL) {
922 			reason = LLCP_DM_NOBOUND;
923 			goto fail;
924 		}
925 	}
926 
927 	lock_sock(&sock->sk);
928 
929 	parent = &sock->sk;
930 
931 	if (sk_acceptq_is_full(parent)) {
932 		reason = LLCP_DM_REJ;
933 		release_sock(&sock->sk);
934 		sock_put(&sock->sk);
935 		goto fail;
936 	}
937 
938 	if (sock->ssap == LLCP_SDP_UNBOUND) {
939 		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
940 
941 		pr_debug("First client, reserving %d\n", ssap);
942 
943 		if (ssap == LLCP_SAP_MAX) {
944 			reason = LLCP_DM_REJ;
945 			release_sock(&sock->sk);
946 			sock_put(&sock->sk);
947 			goto fail;
948 		}
949 
950 		sock->ssap = ssap;
951 	}
952 
953 	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
954 	if (new_sk == NULL) {
955 		reason = LLCP_DM_REJ;
956 		release_sock(&sock->sk);
957 		sock_put(&sock->sk);
958 		goto fail;
959 	}
960 
961 	new_sock = nfc_llcp_sock(new_sk);
962 	new_sock->dev = local->dev;
963 	new_sock->local = nfc_llcp_local_get(local);
964 	new_sock->rw = sock->rw;
965 	new_sock->miux = sock->miux;
966 	new_sock->nfc_protocol = sock->nfc_protocol;
967 	new_sock->dsap = ssap;
968 	new_sock->target_idx = local->target_idx;
969 	new_sock->parent = parent;
970 	new_sock->ssap = sock->ssap;
971 	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
972 		atomic_t *client_count;
973 
974 		pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
975 
976 		client_count =
977 			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
978 
979 		atomic_inc(client_count);
980 		new_sock->reserved_ssap = sock->ssap;
981 	}
982 
983 	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
984 				      skb->len - LLCP_HEADER_SIZE);
985 
986 	pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
987 
988 	nfc_llcp_sock_link(&local->sockets, new_sk);
989 
990 	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
991 
992 	nfc_get_device(local->dev->idx);
993 
994 	new_sk->sk_state = LLCP_CONNECTED;
995 
996 	/* Wake the listening processes */
997 	parent->sk_data_ready(parent);
998 
999 	/* Send CC */
1000 	nfc_llcp_send_cc(new_sock);
1001 
1002 	release_sock(&sock->sk);
1003 	sock_put(&sock->sk);
1004 
1005 	return;
1006 
1007 fail:
1008 	/* Send DM */
1009 	nfc_llcp_send_dm(local, dsap, ssap, reason);
1010 }
1011 
1012 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
1013 {
1014 	int nr_frames = 0;
1015 	struct nfc_llcp_local *local = sock->local;
1016 
1017 	pr_debug("Remote ready %d tx queue len %d remote rw %d",
1018 		 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
1019 		 sock->remote_rw);
1020 
1021 	/* Try to queue some I frames for transmission */
1022 	while (sock->remote_ready &&
1023 	       skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {
1024 		struct sk_buff *pdu;
1025 
1026 		pdu = skb_dequeue(&sock->tx_queue);
1027 		if (pdu == NULL)
1028 			break;
1029 
1030 		/* Update N(S)/N(R) */
1031 		nfc_llcp_set_nrns(sock, pdu);
1032 
1033 		skb_queue_tail(&local->tx_queue, pdu);
1034 		nr_frames++;
1035 	}
1036 
1037 	return nr_frames;
1038 }
1039 
1040 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
1041 			       struct sk_buff *skb)
1042 {
1043 	struct nfc_llcp_sock *llcp_sock;
1044 	struct sock *sk;
1045 	u8 dsap, ssap, ptype, ns, nr;
1046 
1047 	ptype = nfc_llcp_ptype(skb);
1048 	dsap = nfc_llcp_dsap(skb);
1049 	ssap = nfc_llcp_ssap(skb);
1050 	ns = nfc_llcp_ns(skb);
1051 	nr = nfc_llcp_nr(skb);
1052 
1053 	pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
1054 
1055 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1056 	if (llcp_sock == NULL) {
1057 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1058 		return;
1059 	}
1060 
1061 	sk = &llcp_sock->sk;
1062 	lock_sock(sk);
1063 	if (sk->sk_state == LLCP_CLOSED) {
1064 		release_sock(sk);
1065 		nfc_llcp_sock_put(llcp_sock);
1066 	}
1067 
1068 	/* Pass the payload upstream */
1069 	if (ptype == LLCP_PDU_I) {
1070 		pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
1071 
1072 		if (ns == llcp_sock->recv_n)
1073 			llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
1074 		else
1075 			pr_err("Received out of sequence I PDU\n");
1076 
1077 		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
1078 		if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
1079 			/*
1080 			 * I frames will be freed from the socket layer, so we
1081 			 * need to keep them alive until someone receives them.
1082 			 */
1083 			skb_get(skb);
1084 		} else {
1085 			pr_err("Receive queue is full\n");
1086 		}
1087 	}
1088 
1089 	/* Remove skbs from the pending queue */
1090 	if (llcp_sock->send_ack_n != nr) {
1091 		struct sk_buff *s, *tmp;
1092 		u8 n;
1093 
1094 		llcp_sock->send_ack_n = nr;
1095 
1096 		/* Remove and free all skbs until ns == nr */
1097 		skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
1098 			n = nfc_llcp_ns(s);
1099 
1100 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1101 			kfree_skb(s);
1102 
1103 			if (n == nr)
1104 				break;
1105 		}
1106 
1107 		/* Re-queue the remaining skbs for transmission */
1108 		skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1109 					    s, tmp) {
1110 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1111 			skb_queue_head(&local->tx_queue, s);
1112 		}
1113 	}
1114 
1115 	if (ptype == LLCP_PDU_RR)
1116 		llcp_sock->remote_ready = true;
1117 	else if (ptype == LLCP_PDU_RNR)
1118 		llcp_sock->remote_ready = false;
1119 
1120 	if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1121 		nfc_llcp_send_rr(llcp_sock);
1122 
1123 	release_sock(sk);
1124 	nfc_llcp_sock_put(llcp_sock);
1125 }
1126 
1127 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1128 			       const struct sk_buff *skb)
1129 {
1130 	struct nfc_llcp_sock *llcp_sock;
1131 	struct sock *sk;
1132 	u8 dsap, ssap;
1133 
1134 	dsap = nfc_llcp_dsap(skb);
1135 	ssap = nfc_llcp_ssap(skb);
1136 
1137 	if ((dsap == 0) && (ssap == 0)) {
1138 		pr_debug("Connection termination");
1139 		nfc_dep_link_down(local->dev);
1140 		return;
1141 	}
1142 
1143 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1144 	if (llcp_sock == NULL) {
1145 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1146 		return;
1147 	}
1148 
1149 	sk = &llcp_sock->sk;
1150 	lock_sock(sk);
1151 
1152 	nfc_llcp_socket_purge(llcp_sock);
1153 
1154 	if (sk->sk_state == LLCP_CLOSED) {
1155 		release_sock(sk);
1156 		nfc_llcp_sock_put(llcp_sock);
1157 	}
1158 
1159 	if (sk->sk_state == LLCP_CONNECTED) {
1160 		nfc_put_device(local->dev);
1161 		sk->sk_state = LLCP_CLOSED;
1162 		sk->sk_state_change(sk);
1163 	}
1164 
1165 	nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1166 
1167 	release_sock(sk);
1168 	nfc_llcp_sock_put(llcp_sock);
1169 }
1170 
1171 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local,
1172 			     const struct sk_buff *skb)
1173 {
1174 	struct nfc_llcp_sock *llcp_sock;
1175 	struct sock *sk;
1176 	u8 dsap, ssap;
1177 
1178 	dsap = nfc_llcp_dsap(skb);
1179 	ssap = nfc_llcp_ssap(skb);
1180 
1181 	llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1182 	if (llcp_sock == NULL) {
1183 		pr_err("Invalid CC\n");
1184 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1185 
1186 		return;
1187 	}
1188 
1189 	sk = &llcp_sock->sk;
1190 
1191 	/* Unlink from connecting and link to the client array */
1192 	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1193 	nfc_llcp_sock_link(&local->sockets, sk);
1194 	llcp_sock->dsap = ssap;
1195 
1196 	nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1197 				      skb->len - LLCP_HEADER_SIZE);
1198 
1199 	sk->sk_state = LLCP_CONNECTED;
1200 	sk->sk_state_change(sk);
1201 
1202 	nfc_llcp_sock_put(llcp_sock);
1203 }
1204 
1205 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local,
1206 			     const struct sk_buff *skb)
1207 {
1208 	struct nfc_llcp_sock *llcp_sock;
1209 	struct sock *sk;
1210 	u8 dsap, ssap, reason;
1211 
1212 	dsap = nfc_llcp_dsap(skb);
1213 	ssap = nfc_llcp_ssap(skb);
1214 	reason = skb->data[2];
1215 
1216 	pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1217 
1218 	switch (reason) {
1219 	case LLCP_DM_NOBOUND:
1220 	case LLCP_DM_REJ:
1221 		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1222 		break;
1223 
1224 	default:
1225 		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1226 		break;
1227 	}
1228 
1229 	if (llcp_sock == NULL) {
1230 		pr_debug("Already closed\n");
1231 		return;
1232 	}
1233 
1234 	sk = &llcp_sock->sk;
1235 
1236 	sk->sk_err = ENXIO;
1237 	sk->sk_state = LLCP_CLOSED;
1238 	sk->sk_state_change(sk);
1239 
1240 	nfc_llcp_sock_put(llcp_sock);
1241 }
1242 
1243 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1244 			      const struct sk_buff *skb)
1245 {
1246 	struct nfc_llcp_sock *llcp_sock;
1247 	u8 dsap, ssap, type, length, tid, sap;
1248 	const u8 *tlv;
1249 	u16 tlv_len, offset;
1250 	const char *service_name;
1251 	size_t service_name_len;
1252 	struct nfc_llcp_sdp_tlv *sdp;
1253 	HLIST_HEAD(llc_sdres_list);
1254 	size_t sdres_tlvs_len;
1255 	HLIST_HEAD(nl_sdres_list);
1256 
1257 	dsap = nfc_llcp_dsap(skb);
1258 	ssap = nfc_llcp_ssap(skb);
1259 
1260 	pr_debug("%d %d\n", dsap, ssap);
1261 
1262 	if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1263 		pr_err("Wrong SNL SAP\n");
1264 		return;
1265 	}
1266 
1267 	tlv = &skb->data[LLCP_HEADER_SIZE];
1268 	tlv_len = skb->len - LLCP_HEADER_SIZE;
1269 	offset = 0;
1270 	sdres_tlvs_len = 0;
1271 
1272 	while (offset < tlv_len) {
1273 		type = tlv[0];
1274 		length = tlv[1];
1275 
1276 		switch (type) {
1277 		case LLCP_TLV_SDREQ:
1278 			tid = tlv[2];
1279 			service_name = (char *) &tlv[3];
1280 			service_name_len = length - 1;
1281 
1282 			pr_debug("Looking for %.16s\n", service_name);
1283 
1284 			if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1285 			    !strncmp(service_name, "urn:nfc:sn:sdp",
1286 				     service_name_len)) {
1287 				sap = 1;
1288 				goto add_snl;
1289 			}
1290 
1291 			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1292 							  service_name_len,
1293 							  true);
1294 			if (!llcp_sock) {
1295 				sap = 0;
1296 				goto add_snl;
1297 			}
1298 
1299 			/*
1300 			 * We found a socket but its ssap has not been reserved
1301 			 * yet. We need to assign it for good and send a reply.
1302 			 * The ssap will be freed when the socket is closed.
1303 			 */
1304 			if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1305 				atomic_t *client_count;
1306 
1307 				sap = nfc_llcp_reserve_sdp_ssap(local);
1308 
1309 				pr_debug("Reserving %d\n", sap);
1310 
1311 				if (sap == LLCP_SAP_MAX) {
1312 					sap = 0;
1313 					nfc_llcp_sock_put(llcp_sock);
1314 					goto add_snl;
1315 				}
1316 
1317 				client_count =
1318 					&local->local_sdp_cnt[sap -
1319 							      LLCP_WKS_NUM_SAP];
1320 
1321 				atomic_inc(client_count);
1322 
1323 				llcp_sock->ssap = sap;
1324 				llcp_sock->reserved_ssap = sap;
1325 			} else {
1326 				sap = llcp_sock->ssap;
1327 			}
1328 
1329 			pr_debug("%p %d\n", llcp_sock, sap);
1330 
1331 			nfc_llcp_sock_put(llcp_sock);
1332 add_snl:
1333 			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
1334 			if (sdp == NULL)
1335 				goto exit;
1336 
1337 			sdres_tlvs_len += sdp->tlv_len;
1338 			hlist_add_head(&sdp->node, &llc_sdres_list);
1339 			break;
1340 
1341 		case LLCP_TLV_SDRES:
1342 			mutex_lock(&local->sdreq_lock);
1343 
1344 			pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]);
1345 
1346 			hlist_for_each_entry(sdp, &local->pending_sdreqs, node) {
1347 				if (sdp->tid != tlv[2])
1348 					continue;
1349 
1350 				sdp->sap = tlv[3];
1351 
1352 				pr_debug("Found: uri=%s, sap=%d\n",
1353 					 sdp->uri, sdp->sap);
1354 
1355 				hlist_del(&sdp->node);
1356 
1357 				hlist_add_head(&sdp->node, &nl_sdres_list);
1358 
1359 				break;
1360 			}
1361 
1362 			mutex_unlock(&local->sdreq_lock);
1363 			break;
1364 
1365 		default:
1366 			pr_err("Invalid SNL tlv value 0x%x\n", type);
1367 			break;
1368 		}
1369 
1370 		offset += length + 2;
1371 		tlv += length + 2;
1372 	}
1373 
1374 exit:
1375 	if (!hlist_empty(&nl_sdres_list))
1376 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
1377 
1378 	if (!hlist_empty(&llc_sdres_list))
1379 		nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);
1380 }
1381 
1382 static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
1383 {
1384 	u8 ptype;
1385 	u16 pdu_len;
1386 	struct sk_buff *new_skb;
1387 
1388 	if (skb->len <= LLCP_HEADER_SIZE) {
1389 		pr_err("Malformed AGF PDU\n");
1390 		return;
1391 	}
1392 
1393 	skb_pull(skb, LLCP_HEADER_SIZE);
1394 
1395 	while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) {
1396 		pdu_len = skb->data[0] << 8 | skb->data[1];
1397 
1398 		skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE);
1399 
1400 		if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) {
1401 			pr_err("Malformed AGF PDU\n");
1402 			return;
1403 		}
1404 
1405 		ptype = nfc_llcp_ptype(skb);
1406 
1407 		if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF)
1408 			goto next;
1409 
1410 		new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
1411 		if (new_skb == NULL) {
1412 			pr_err("Could not allocate PDU\n");
1413 			return;
1414 		}
1415 
1416 		skb_put_data(new_skb, skb->data, pdu_len);
1417 
1418 		nfc_llcp_rx_skb(local, new_skb);
1419 
1420 		kfree_skb(new_skb);
1421 next:
1422 		skb_pull(skb, pdu_len);
1423 	}
1424 }
1425 
1426 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
1427 {
1428 	u8 dsap, ssap, ptype;
1429 
1430 	ptype = nfc_llcp_ptype(skb);
1431 	dsap = nfc_llcp_dsap(skb);
1432 	ssap = nfc_llcp_ssap(skb);
1433 
1434 	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1435 
1436 	if (ptype != LLCP_PDU_SYMM)
1437 		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
1438 				     skb->data, skb->len, true);
1439 
1440 	switch (ptype) {
1441 	case LLCP_PDU_SYMM:
1442 		pr_debug("SYMM\n");
1443 		break;
1444 
1445 	case LLCP_PDU_UI:
1446 		pr_debug("UI\n");
1447 		nfc_llcp_recv_ui(local, skb);
1448 		break;
1449 
1450 	case LLCP_PDU_CONNECT:
1451 		pr_debug("CONNECT\n");
1452 		nfc_llcp_recv_connect(local, skb);
1453 		break;
1454 
1455 	case LLCP_PDU_DISC:
1456 		pr_debug("DISC\n");
1457 		nfc_llcp_recv_disc(local, skb);
1458 		break;
1459 
1460 	case LLCP_PDU_CC:
1461 		pr_debug("CC\n");
1462 		nfc_llcp_recv_cc(local, skb);
1463 		break;
1464 
1465 	case LLCP_PDU_DM:
1466 		pr_debug("DM\n");
1467 		nfc_llcp_recv_dm(local, skb);
1468 		break;
1469 
1470 	case LLCP_PDU_SNL:
1471 		pr_debug("SNL\n");
1472 		nfc_llcp_recv_snl(local, skb);
1473 		break;
1474 
1475 	case LLCP_PDU_I:
1476 	case LLCP_PDU_RR:
1477 	case LLCP_PDU_RNR:
1478 		pr_debug("I frame\n");
1479 		nfc_llcp_recv_hdlc(local, skb);
1480 		break;
1481 
1482 	case LLCP_PDU_AGF:
1483 		pr_debug("AGF frame\n");
1484 		nfc_llcp_recv_agf(local, skb);
1485 		break;
1486 	}
1487 }
1488 
1489 static void nfc_llcp_rx_work(struct work_struct *work)
1490 {
1491 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1492 						    rx_work);
1493 	struct sk_buff *skb;
1494 
1495 	skb = local->rx_pending;
1496 	if (skb == NULL) {
1497 		pr_debug("No pending SKB\n");
1498 		return;
1499 	}
1500 
1501 	__net_timestamp(skb);
1502 
1503 	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);
1504 
1505 	nfc_llcp_rx_skb(local, skb);
1506 
1507 	schedule_work(&local->tx_work);
1508 	kfree_skb(local->rx_pending);
1509 	local->rx_pending = NULL;
1510 }
1511 
1512 static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
1513 {
1514 	local->rx_pending = skb;
1515 	del_timer(&local->link_timer);
1516 	schedule_work(&local->rx_work);
1517 }
1518 
1519 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1520 {
1521 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1522 
1523 	if (err < 0) {
1524 		pr_err("LLCP PDU receive err %d\n", err);
1525 		return;
1526 	}
1527 
1528 	__nfc_llcp_recv(local, skb);
1529 }
1530 
1531 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1532 {
1533 	struct nfc_llcp_local *local;
1534 
1535 	local = nfc_llcp_find_local(dev);
1536 	if (local == NULL) {
1537 		kfree_skb(skb);
1538 		return -ENODEV;
1539 	}
1540 
1541 	__nfc_llcp_recv(local, skb);
1542 
1543 	nfc_llcp_local_put(local);
1544 
1545 	return 0;
1546 }
1547 
1548 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1549 {
1550 	struct nfc_llcp_local *local;
1551 
1552 	local = nfc_llcp_find_local(dev);
1553 	if (local == NULL)
1554 		return;
1555 
1556 	local->remote_miu = LLCP_DEFAULT_MIU;
1557 	local->remote_lto = LLCP_DEFAULT_LTO;
1558 
1559 	/* Close and purge all existing sockets */
1560 	nfc_llcp_socket_release(local, true, 0);
1561 
1562 	nfc_llcp_local_put(local);
1563 }
1564 
1565 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1566 			u8 comm_mode, u8 rf_mode)
1567 {
1568 	struct nfc_llcp_local *local;
1569 
1570 	pr_debug("rf mode %d\n", rf_mode);
1571 
1572 	local = nfc_llcp_find_local(dev);
1573 	if (local == NULL)
1574 		return;
1575 
1576 	local->target_idx = target_idx;
1577 	local->comm_mode = comm_mode;
1578 	local->rf_mode = rf_mode;
1579 
1580 	if (rf_mode == NFC_RF_INITIATOR) {
1581 		pr_debug("Queueing Tx work\n");
1582 
1583 		schedule_work(&local->tx_work);
1584 	} else {
1585 		mod_timer(&local->link_timer,
1586 			  jiffies + msecs_to_jiffies(local->remote_lto));
1587 	}
1588 
1589 	nfc_llcp_local_put(local);
1590 }
1591 
1592 int nfc_llcp_register_device(struct nfc_dev *ndev)
1593 {
1594 	struct nfc_llcp_local *local;
1595 
1596 	local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1597 	if (local == NULL)
1598 		return -ENOMEM;
1599 
1600 	local->dev = ndev;
1601 	INIT_LIST_HEAD(&local->list);
1602 	kref_init(&local->ref);
1603 	mutex_init(&local->sdp_lock);
1604 	timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0);
1605 
1606 	skb_queue_head_init(&local->tx_queue);
1607 	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1608 
1609 	local->rx_pending = NULL;
1610 	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1611 
1612 	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1613 
1614 	rwlock_init(&local->sockets.lock);
1615 	rwlock_init(&local->connecting_sockets.lock);
1616 	rwlock_init(&local->raw_sockets.lock);
1617 
1618 	local->lto = 150; /* 1500 ms */
1619 	local->rw = LLCP_MAX_RW;
1620 	local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1621 	local->local_wks = 0x1; /* LLC Link Management */
1622 
1623 	nfc_llcp_build_gb(local);
1624 
1625 	local->remote_miu = LLCP_DEFAULT_MIU;
1626 	local->remote_lto = LLCP_DEFAULT_LTO;
1627 
1628 	mutex_init(&local->sdreq_lock);
1629 	INIT_HLIST_HEAD(&local->pending_sdreqs);
1630 	timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0);
1631 	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
1632 
1633 	spin_lock(&llcp_devices_lock);
1634 	list_add(&local->list, &llcp_devices);
1635 	spin_unlock(&llcp_devices_lock);
1636 
1637 	return 0;
1638 }
1639 
1640 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1641 {
1642 	struct nfc_llcp_local *local = nfc_llcp_remove_local(dev);
1643 
1644 	if (local == NULL) {
1645 		pr_debug("No such device\n");
1646 		return;
1647 	}
1648 
1649 	local_cleanup(local);
1650 
1651 	nfc_llcp_local_put(local);
1652 }
1653 
1654 int __init nfc_llcp_init(void)
1655 {
1656 	return nfc_llcp_sock_init();
1657 }
1658 
1659 void nfc_llcp_exit(void)
1660 {
1661 	nfc_llcp_sock_exit();
1662 }
1663