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 	/* Since using nfc_llcp_local may result in usage of nfc_dev, whenever
149 	 * we hold a reference to local, we also need to hold a reference to
150 	 * the device to avoid UAF.
151 	 */
152 	if (!nfc_get_device(local->dev->idx))
153 		return NULL;
154 
155 	kref_get(&local->ref);
156 
157 	return local;
158 }
159 
160 static void local_cleanup(struct nfc_llcp_local *local)
161 {
162 	nfc_llcp_socket_release(local, false, ENXIO);
163 	timer_delete_sync(&local->link_timer);
164 	skb_queue_purge(&local->tx_queue);
165 	cancel_work_sync(&local->tx_work);
166 	cancel_work_sync(&local->rx_work);
167 	cancel_work_sync(&local->timeout_work);
168 	kfree_skb(local->rx_pending);
169 	local->rx_pending = NULL;
170 	timer_delete_sync(&local->sdreq_timer);
171 	cancel_work_sync(&local->sdreq_timeout_work);
172 	nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);
173 }
174 
175 static void local_release(struct kref *ref)
176 {
177 	struct nfc_llcp_local *local;
178 
179 	local = container_of(ref, struct nfc_llcp_local, ref);
180 
181 	local_cleanup(local);
182 	kfree(local);
183 }
184 
185 int nfc_llcp_local_put(struct nfc_llcp_local *local)
186 {
187 	struct nfc_dev *dev;
188 	int ret;
189 
190 	if (local == NULL)
191 		return 0;
192 
193 	dev = local->dev;
194 
195 	ret = kref_put(&local->ref, local_release);
196 	nfc_put_device(dev);
197 
198 	return ret;
199 }
200 
201 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
202 					       u8 ssap, u8 dsap)
203 {
204 	struct sock *sk;
205 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
206 
207 	pr_debug("ssap dsap %d %d\n", ssap, dsap);
208 
209 	if (ssap == 0 && dsap == 0)
210 		return NULL;
211 
212 	read_lock(&local->sockets.lock);
213 
214 	llcp_sock = NULL;
215 
216 	sk_for_each(sk, &local->sockets.head) {
217 		tmp_sock = nfc_llcp_sock(sk);
218 
219 		if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
220 			llcp_sock = tmp_sock;
221 			sock_hold(&llcp_sock->sk);
222 			break;
223 		}
224 	}
225 
226 	read_unlock(&local->sockets.lock);
227 
228 	return llcp_sock;
229 }
230 
231 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
232 {
233 	sock_put(&sock->sk);
234 }
235 
236 static void nfc_llcp_timeout_work(struct work_struct *work)
237 {
238 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
239 						    timeout_work);
240 
241 	nfc_dep_link_down(local->dev);
242 }
243 
244 static void nfc_llcp_symm_timer(struct timer_list *t)
245 {
246 	struct nfc_llcp_local *local = timer_container_of(local, t,
247 							  link_timer);
248 
249 	pr_err("SYMM timeout\n");
250 
251 	schedule_work(&local->timeout_work);
252 }
253 
254 static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
255 {
256 	unsigned long time;
257 	HLIST_HEAD(nl_sdres_list);
258 	struct hlist_node *n;
259 	struct nfc_llcp_sdp_tlv *sdp;
260 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
261 						    sdreq_timeout_work);
262 
263 	mutex_lock(&local->sdreq_lock);
264 
265 	time = jiffies - msecs_to_jiffies(3 * local->remote_lto);
266 
267 	hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) {
268 		if (time_after(sdp->time, time))
269 			continue;
270 
271 		sdp->sap = LLCP_SDP_UNBOUND;
272 
273 		hlist_del(&sdp->node);
274 
275 		hlist_add_head(&sdp->node, &nl_sdres_list);
276 	}
277 
278 	if (!hlist_empty(&local->pending_sdreqs))
279 		mod_timer(&local->sdreq_timer,
280 			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
281 
282 	mutex_unlock(&local->sdreq_lock);
283 
284 	if (!hlist_empty(&nl_sdres_list))
285 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
286 }
287 
288 static void nfc_llcp_sdreq_timer(struct timer_list *t)
289 {
290 	struct nfc_llcp_local *local = timer_container_of(local, t,
291 							  sdreq_timer);
292 
293 	schedule_work(&local->sdreq_timeout_work);
294 }
295 
296 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
297 {
298 	struct nfc_llcp_local *local;
299 	struct nfc_llcp_local *res = NULL;
300 
301 	spin_lock(&llcp_devices_lock);
302 	list_for_each_entry(local, &llcp_devices, list)
303 		if (local->dev == dev) {
304 			res = nfc_llcp_local_get(local);
305 			break;
306 		}
307 	spin_unlock(&llcp_devices_lock);
308 
309 	return res;
310 }
311 
312 static struct nfc_llcp_local *nfc_llcp_remove_local(struct nfc_dev *dev)
313 {
314 	struct nfc_llcp_local *local, *tmp;
315 
316 	spin_lock(&llcp_devices_lock);
317 	list_for_each_entry_safe(local, tmp, &llcp_devices, list)
318 		if (local->dev == dev) {
319 			list_del(&local->list);
320 			spin_unlock(&llcp_devices_lock);
321 			return local;
322 		}
323 	spin_unlock(&llcp_devices_lock);
324 
325 	pr_warn("Shutting down device not found\n");
326 
327 	return NULL;
328 }
329 
330 static char *wks[] = {
331 	NULL,
332 	NULL, /* SDP */
333 	"urn:nfc:sn:ip",
334 	"urn:nfc:sn:obex",
335 	"urn:nfc:sn:snep",
336 };
337 
338 static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len)
339 {
340 	int sap, num_wks;
341 
342 	pr_debug("%s\n", service_name);
343 
344 	if (service_name == NULL)
345 		return -EINVAL;
346 
347 	num_wks = ARRAY_SIZE(wks);
348 
349 	for (sap = 0; sap < num_wks; sap++) {
350 		if (wks[sap] == NULL)
351 			continue;
352 
353 		if (strncmp(wks[sap], service_name, service_name_len) == 0)
354 			return sap;
355 	}
356 
357 	return -EINVAL;
358 }
359 
360 static
361 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
362 					    const u8 *sn, size_t sn_len,
363 					    bool needref)
364 {
365 	struct sock *sk;
366 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
367 
368 	pr_debug("sn %zd %p\n", sn_len, sn);
369 
370 	if (sn == NULL || sn_len == 0)
371 		return NULL;
372 
373 	read_lock(&local->sockets.lock);
374 
375 	llcp_sock = NULL;
376 
377 	sk_for_each(sk, &local->sockets.head) {
378 		tmp_sock = nfc_llcp_sock(sk);
379 
380 		pr_debug("llcp sock %p\n", tmp_sock);
381 
382 		if (tmp_sock->sk.sk_type == SOCK_STREAM &&
383 		    tmp_sock->sk.sk_state != LLCP_LISTEN)
384 			continue;
385 
386 		if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
387 		    tmp_sock->sk.sk_state != LLCP_BOUND)
388 			continue;
389 
390 		if (tmp_sock->service_name == NULL ||
391 		    tmp_sock->service_name_len == 0)
392 			continue;
393 
394 		if (tmp_sock->service_name_len != sn_len)
395 			continue;
396 
397 		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
398 			llcp_sock = tmp_sock;
399 			if (needref)
400 				sock_hold(&llcp_sock->sk);
401 			break;
402 		}
403 	}
404 
405 	read_unlock(&local->sockets.lock);
406 
407 	pr_debug("Found llcp sock %p\n", llcp_sock);
408 
409 	return llcp_sock;
410 }
411 
412 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
413 			 struct nfc_llcp_sock *sock)
414 {
415 	mutex_lock(&local->sdp_lock);
416 
417 	if (sock->service_name != NULL && sock->service_name_len > 0) {
418 		int ssap = nfc_llcp_wks_sap(sock->service_name,
419 					    sock->service_name_len);
420 
421 		if (ssap > 0) {
422 			pr_debug("WKS %d\n", ssap);
423 
424 			/* This is a WKS, let's check if it's free */
425 			if (test_bit(ssap, &local->local_wks)) {
426 				mutex_unlock(&local->sdp_lock);
427 
428 				return LLCP_SAP_MAX;
429 			}
430 
431 			set_bit(ssap, &local->local_wks);
432 			mutex_unlock(&local->sdp_lock);
433 
434 			return ssap;
435 		}
436 
437 		/*
438 		 * Check if there already is a non WKS socket bound
439 		 * to this service name.
440 		 */
441 		if (nfc_llcp_sock_from_sn(local, sock->service_name,
442 					  sock->service_name_len,
443 					  false) != NULL) {
444 			mutex_unlock(&local->sdp_lock);
445 
446 			return LLCP_SAP_MAX;
447 		}
448 
449 		mutex_unlock(&local->sdp_lock);
450 
451 		return LLCP_SDP_UNBOUND;
452 
453 	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
454 		if (!test_bit(sock->ssap, &local->local_wks)) {
455 			set_bit(sock->ssap, &local->local_wks);
456 			mutex_unlock(&local->sdp_lock);
457 
458 			return sock->ssap;
459 		}
460 	}
461 
462 	mutex_unlock(&local->sdp_lock);
463 
464 	return LLCP_SAP_MAX;
465 }
466 
467 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
468 {
469 	u8 local_ssap;
470 
471 	mutex_lock(&local->sdp_lock);
472 
473 	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
474 	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
475 		mutex_unlock(&local->sdp_lock);
476 		return LLCP_SAP_MAX;
477 	}
478 
479 	set_bit(local_ssap, &local->local_sap);
480 
481 	mutex_unlock(&local->sdp_lock);
482 
483 	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
484 }
485 
486 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
487 {
488 	u8 local_ssap;
489 	unsigned long *sdp;
490 
491 	if (ssap < LLCP_WKS_NUM_SAP) {
492 		local_ssap = ssap;
493 		sdp = &local->local_wks;
494 	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
495 		atomic_t *client_cnt;
496 
497 		local_ssap = ssap - LLCP_WKS_NUM_SAP;
498 		sdp = &local->local_sdp;
499 		client_cnt = &local->local_sdp_cnt[local_ssap];
500 
501 		pr_debug("%d clients\n", atomic_read(client_cnt));
502 
503 		mutex_lock(&local->sdp_lock);
504 
505 		if (atomic_dec_and_test(client_cnt)) {
506 			struct nfc_llcp_sock *l_sock;
507 
508 			pr_debug("No more clients for SAP %d\n", ssap);
509 
510 			clear_bit(local_ssap, sdp);
511 
512 			/* Find the listening sock and set it back to UNBOUND */
513 			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
514 			if (l_sock) {
515 				l_sock->ssap = LLCP_SDP_UNBOUND;
516 				nfc_llcp_sock_put(l_sock);
517 			}
518 		}
519 
520 		mutex_unlock(&local->sdp_lock);
521 
522 		return;
523 	} else if (ssap < LLCP_MAX_SAP) {
524 		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
525 		sdp = &local->local_sap;
526 	} else {
527 		return;
528 	}
529 
530 	mutex_lock(&local->sdp_lock);
531 
532 	clear_bit(local_ssap, sdp);
533 
534 	mutex_unlock(&local->sdp_lock);
535 }
536 
537 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
538 {
539 	u8 ssap;
540 
541 	mutex_lock(&local->sdp_lock);
542 
543 	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
544 	if (ssap == LLCP_SDP_NUM_SAP) {
545 		mutex_unlock(&local->sdp_lock);
546 
547 		return LLCP_SAP_MAX;
548 	}
549 
550 	pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
551 
552 	set_bit(ssap, &local->local_sdp);
553 
554 	mutex_unlock(&local->sdp_lock);
555 
556 	return LLCP_WKS_NUM_SAP + ssap;
557 }
558 
559 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
560 {
561 	u8 *gb_cur, version, version_length;
562 	u8 lto_length, wks_length, miux_length;
563 	const u8 *version_tlv = NULL, *lto_tlv = NULL,
564 	   *wks_tlv = NULL, *miux_tlv = NULL;
565 	__be16 wks = cpu_to_be16(local->local_wks);
566 	u8 gb_len = 0;
567 	int ret = 0;
568 
569 	version = LLCP_VERSION_11;
570 	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
571 					 1, &version_length);
572 	if (!version_tlv) {
573 		ret = -ENOMEM;
574 		goto out;
575 	}
576 	gb_len += version_length;
577 
578 	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
579 	if (!lto_tlv) {
580 		ret = -ENOMEM;
581 		goto out;
582 	}
583 	gb_len += lto_length;
584 
585 	pr_debug("Local wks 0x%lx\n", local->local_wks);
586 	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
587 	if (!wks_tlv) {
588 		ret = -ENOMEM;
589 		goto out;
590 	}
591 	gb_len += wks_length;
592 
593 	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
594 				      &miux_length);
595 	if (!miux_tlv) {
596 		ret = -ENOMEM;
597 		goto out;
598 	}
599 	gb_len += miux_length;
600 
601 	gb_len += ARRAY_SIZE(llcp_magic);
602 
603 	if (gb_len > NFC_MAX_GT_LEN) {
604 		ret = -EINVAL;
605 		goto out;
606 	}
607 
608 	gb_cur = local->gb;
609 
610 	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
611 	gb_cur += ARRAY_SIZE(llcp_magic);
612 
613 	memcpy(gb_cur, version_tlv, version_length);
614 	gb_cur += version_length;
615 
616 	memcpy(gb_cur, lto_tlv, lto_length);
617 	gb_cur += lto_length;
618 
619 	memcpy(gb_cur, wks_tlv, wks_length);
620 	gb_cur += wks_length;
621 
622 	memcpy(gb_cur, miux_tlv, miux_length);
623 	gb_cur += miux_length;
624 
625 	local->gb_len = gb_len;
626 
627 out:
628 	kfree(version_tlv);
629 	kfree(lto_tlv);
630 	kfree(wks_tlv);
631 	kfree(miux_tlv);
632 
633 	return ret;
634 }
635 
636 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
637 {
638 	struct nfc_llcp_local *local;
639 
640 	local = nfc_llcp_find_local(dev);
641 	if (local == NULL) {
642 		*general_bytes_len = 0;
643 		return NULL;
644 	}
645 
646 	nfc_llcp_build_gb(local);
647 
648 	*general_bytes_len = local->gb_len;
649 
650 	nfc_llcp_local_put(local);
651 
652 	return local->gb;
653 }
654 
655 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, const u8 *gb, u8 gb_len)
656 {
657 	struct nfc_llcp_local *local;
658 	int err;
659 
660 	if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
661 		return -EINVAL;
662 
663 	local = nfc_llcp_find_local(dev);
664 	if (local == NULL) {
665 		pr_err("No LLCP device\n");
666 		return -ENODEV;
667 	}
668 
669 	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
670 	memcpy(local->remote_gb, gb, gb_len);
671 	local->remote_gb_len = gb_len;
672 
673 	if (memcmp(local->remote_gb, llcp_magic, 3)) {
674 		pr_err("MAC does not support LLCP\n");
675 		err = -EINVAL;
676 		goto out;
677 	}
678 
679 	err = nfc_llcp_parse_gb_tlv(local,
680 				     &local->remote_gb[3],
681 				     local->remote_gb_len - 3);
682 out:
683 	nfc_llcp_local_put(local);
684 	return err;
685 }
686 
687 static u8 nfc_llcp_dsap(const struct sk_buff *pdu)
688 {
689 	return (pdu->data[0] & 0xfc) >> 2;
690 }
691 
692 static u8 nfc_llcp_ptype(const struct sk_buff *pdu)
693 {
694 	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
695 }
696 
697 static u8 nfc_llcp_ssap(const struct sk_buff *pdu)
698 {
699 	return pdu->data[1] & 0x3f;
700 }
701 
702 static u8 nfc_llcp_ns(const struct sk_buff *pdu)
703 {
704 	return pdu->data[2] >> 4;
705 }
706 
707 static u8 nfc_llcp_nr(const struct sk_buff *pdu)
708 {
709 	return pdu->data[2] & 0xf;
710 }
711 
712 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
713 {
714 	pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
715 	sock->send_n = (sock->send_n + 1) % 16;
716 	sock->recv_ack_n = (sock->recv_n - 1) % 16;
717 }
718 
719 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
720 			       struct sk_buff *skb, u8 direction)
721 {
722 	struct sk_buff *skb_copy = NULL, *nskb;
723 	struct sock *sk;
724 	u8 *data;
725 
726 	read_lock(&local->raw_sockets.lock);
727 
728 	sk_for_each(sk, &local->raw_sockets.head) {
729 		if (sk->sk_state != LLCP_BOUND)
730 			continue;
731 
732 		if (skb_copy == NULL) {
733 			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
734 						      GFP_ATOMIC, true);
735 
736 			if (skb_copy == NULL)
737 				continue;
738 
739 			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
740 
741 			data[0] = local->dev ? local->dev->idx : 0xFF;
742 			data[1] = direction & 0x01;
743 			data[1] |= (RAW_PAYLOAD_LLCP << 1);
744 		}
745 
746 		nskb = skb_clone(skb_copy, GFP_ATOMIC);
747 		if (!nskb)
748 			continue;
749 
750 		if (sock_queue_rcv_skb(sk, nskb))
751 			kfree_skb(nskb);
752 	}
753 
754 	read_unlock(&local->raw_sockets.lock);
755 
756 	kfree_skb(skb_copy);
757 }
758 
759 static void nfc_llcp_tx_work(struct work_struct *work)
760 {
761 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
762 						    tx_work);
763 	struct sk_buff *skb;
764 	struct sock *sk;
765 	struct nfc_llcp_sock *llcp_sock;
766 
767 	skb = skb_dequeue(&local->tx_queue);
768 	if (skb != NULL) {
769 		sk = skb->sk;
770 		llcp_sock = nfc_llcp_sock(sk);
771 
772 		if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
773 			kfree_skb(skb);
774 			nfc_llcp_send_symm(local->dev);
775 		} else if (llcp_sock && !llcp_sock->remote_ready) {
776 			skb_queue_head(&local->tx_queue, skb);
777 			nfc_llcp_send_symm(local->dev);
778 		} else {
779 			struct sk_buff *copy_skb = NULL;
780 			u8 ptype = nfc_llcp_ptype(skb);
781 			int ret;
782 
783 			pr_debug("Sending pending skb\n");
784 			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
785 					     16, 1, skb->data, skb->len, true);
786 
787 			if (ptype == LLCP_PDU_I)
788 				copy_skb = skb_copy(skb, GFP_ATOMIC);
789 
790 			__net_timestamp(skb);
791 
792 			nfc_llcp_send_to_raw_sock(local, skb,
793 						  NFC_DIRECTION_TX);
794 
795 			ret = nfc_data_exchange(local->dev, local->target_idx,
796 						skb, nfc_llcp_recv, local);
797 
798 			if (ret) {
799 				kfree_skb(copy_skb);
800 				goto out;
801 			}
802 
803 			if (ptype == LLCP_PDU_I && copy_skb)
804 				skb_queue_tail(&llcp_sock->tx_pending_queue,
805 					       copy_skb);
806 		}
807 	} else {
808 		nfc_llcp_send_symm(local->dev);
809 	}
810 
811 out:
812 	mod_timer(&local->link_timer,
813 		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
814 }
815 
816 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
817 							  u8 ssap)
818 {
819 	struct sock *sk;
820 	struct nfc_llcp_sock *llcp_sock;
821 
822 	read_lock(&local->connecting_sockets.lock);
823 
824 	sk_for_each(sk, &local->connecting_sockets.head) {
825 		llcp_sock = nfc_llcp_sock(sk);
826 
827 		if (llcp_sock->ssap == ssap) {
828 			sock_hold(&llcp_sock->sk);
829 			goto out;
830 		}
831 	}
832 
833 	llcp_sock = NULL;
834 
835 out:
836 	read_unlock(&local->connecting_sockets.lock);
837 
838 	return llcp_sock;
839 }
840 
841 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
842 						  const u8 *sn, size_t sn_len)
843 {
844 	return nfc_llcp_sock_from_sn(local, sn, sn_len, true);
845 }
846 
847 static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
848 {
849 	u8 type, length;
850 	const u8 *tlv = &skb->data[2];
851 	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
852 
853 	while (offset < tlv_array_len) {
854 		type = tlv[0];
855 		length = tlv[1];
856 
857 		pr_debug("type 0x%x length %d\n", type, length);
858 
859 		if (type == LLCP_TLV_SN) {
860 			*sn_len = length;
861 			return &tlv[2];
862 		}
863 
864 		offset += length + 2;
865 		tlv += length + 2;
866 	}
867 
868 	return NULL;
869 }
870 
871 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
872 			     struct sk_buff *skb)
873 {
874 	struct nfc_llcp_sock *llcp_sock;
875 	struct nfc_llcp_ui_cb *ui_cb;
876 	u8 dsap, ssap;
877 
878 	dsap = nfc_llcp_dsap(skb);
879 	ssap = nfc_llcp_ssap(skb);
880 
881 	ui_cb = nfc_llcp_ui_skb_cb(skb);
882 	ui_cb->dsap = dsap;
883 	ui_cb->ssap = ssap;
884 
885 	pr_debug("%d %d\n", dsap, ssap);
886 
887 	/* We're looking for a bound socket, not a client one */
888 	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
889 	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
890 		return;
891 
892 	/* There is no sequence with UI frames */
893 	skb_pull(skb, LLCP_HEADER_SIZE);
894 	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
895 		/*
896 		 * UI frames will be freed from the socket layer, so we
897 		 * need to keep them alive until someone receives them.
898 		 */
899 		skb_get(skb);
900 	} else {
901 		pr_err("Receive queue is full\n");
902 	}
903 
904 	nfc_llcp_sock_put(llcp_sock);
905 }
906 
907 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
908 				  const struct sk_buff *skb)
909 {
910 	struct sock *new_sk, *parent;
911 	struct nfc_llcp_sock *sock, *new_sock;
912 	u8 dsap, ssap, reason;
913 
914 	dsap = nfc_llcp_dsap(skb);
915 	ssap = nfc_llcp_ssap(skb);
916 
917 	pr_debug("%d %d\n", dsap, ssap);
918 
919 	if (dsap != LLCP_SAP_SDP) {
920 		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
921 		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
922 			reason = LLCP_DM_NOBOUND;
923 			goto fail;
924 		}
925 	} else {
926 		const u8 *sn;
927 		size_t sn_len;
928 
929 		sn = nfc_llcp_connect_sn(skb, &sn_len);
930 		if (sn == NULL) {
931 			reason = LLCP_DM_NOBOUND;
932 			goto fail;
933 		}
934 
935 		pr_debug("Service name length %zu\n", sn_len);
936 
937 		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
938 		if (sock == NULL) {
939 			reason = LLCP_DM_NOBOUND;
940 			goto fail;
941 		}
942 	}
943 
944 	lock_sock(&sock->sk);
945 
946 	parent = &sock->sk;
947 
948 	if (sk_acceptq_is_full(parent)) {
949 		reason = LLCP_DM_REJ;
950 		release_sock(&sock->sk);
951 		sock_put(&sock->sk);
952 		goto fail;
953 	}
954 
955 	if (sock->ssap == LLCP_SDP_UNBOUND) {
956 		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
957 
958 		pr_debug("First client, reserving %d\n", ssap);
959 
960 		if (ssap == LLCP_SAP_MAX) {
961 			reason = LLCP_DM_REJ;
962 			release_sock(&sock->sk);
963 			sock_put(&sock->sk);
964 			goto fail;
965 		}
966 
967 		sock->ssap = ssap;
968 	}
969 
970 	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
971 	if (new_sk == NULL) {
972 		reason = LLCP_DM_REJ;
973 		release_sock(&sock->sk);
974 		sock_put(&sock->sk);
975 		goto fail;
976 	}
977 
978 	new_sock = nfc_llcp_sock(new_sk);
979 
980 	new_sock->local = nfc_llcp_local_get(local);
981 	if (!new_sock->local) {
982 		reason = LLCP_DM_REJ;
983 		sock_put(&new_sock->sk);
984 		release_sock(&sock->sk);
985 		sock_put(&sock->sk);
986 		goto fail;
987 	}
988 
989 	new_sock->dev = local->dev;
990 	new_sock->rw = sock->rw;
991 	new_sock->miux = sock->miux;
992 	new_sock->nfc_protocol = sock->nfc_protocol;
993 	new_sock->dsap = ssap;
994 	new_sock->target_idx = local->target_idx;
995 	new_sock->parent = parent;
996 	new_sock->ssap = sock->ssap;
997 	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
998 		atomic_t *client_count;
999 
1000 		pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
1001 
1002 		client_count =
1003 			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
1004 
1005 		atomic_inc(client_count);
1006 		new_sock->reserved_ssap = sock->ssap;
1007 	}
1008 
1009 	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
1010 				      skb->len - LLCP_HEADER_SIZE);
1011 
1012 	pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
1013 
1014 	nfc_llcp_sock_link(&local->sockets, new_sk);
1015 
1016 	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
1017 
1018 	nfc_get_device(local->dev->idx);
1019 
1020 	new_sk->sk_state = LLCP_CONNECTED;
1021 
1022 	/* Wake the listening processes */
1023 	parent->sk_data_ready(parent);
1024 
1025 	/* Send CC */
1026 	nfc_llcp_send_cc(new_sock);
1027 
1028 	release_sock(&sock->sk);
1029 	sock_put(&sock->sk);
1030 
1031 	return;
1032 
1033 fail:
1034 	/* Send DM */
1035 	nfc_llcp_send_dm(local, dsap, ssap, reason);
1036 }
1037 
1038 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
1039 {
1040 	int nr_frames = 0;
1041 	struct nfc_llcp_local *local = sock->local;
1042 
1043 	pr_debug("Remote ready %d tx queue len %d remote rw %d",
1044 		 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
1045 		 sock->remote_rw);
1046 
1047 	/* Try to queue some I frames for transmission */
1048 	while (sock->remote_ready &&
1049 	       skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {
1050 		struct sk_buff *pdu;
1051 
1052 		pdu = skb_dequeue(&sock->tx_queue);
1053 		if (pdu == NULL)
1054 			break;
1055 
1056 		/* Update N(S)/N(R) */
1057 		nfc_llcp_set_nrns(sock, pdu);
1058 
1059 		skb_queue_tail(&local->tx_queue, pdu);
1060 		nr_frames++;
1061 	}
1062 
1063 	return nr_frames;
1064 }
1065 
1066 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
1067 			       struct sk_buff *skb)
1068 {
1069 	struct nfc_llcp_sock *llcp_sock;
1070 	struct sock *sk;
1071 	u8 dsap, ssap, ptype, ns, nr;
1072 
1073 	ptype = nfc_llcp_ptype(skb);
1074 	dsap = nfc_llcp_dsap(skb);
1075 	ssap = nfc_llcp_ssap(skb);
1076 	ns = nfc_llcp_ns(skb);
1077 	nr = nfc_llcp_nr(skb);
1078 
1079 	pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
1080 
1081 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1082 	if (llcp_sock == NULL) {
1083 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1084 		return;
1085 	}
1086 
1087 	sk = &llcp_sock->sk;
1088 	lock_sock(sk);
1089 	if (sk->sk_state == LLCP_CLOSED) {
1090 		release_sock(sk);
1091 		nfc_llcp_sock_put(llcp_sock);
1092 	}
1093 
1094 	/* Pass the payload upstream */
1095 	if (ptype == LLCP_PDU_I) {
1096 		pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
1097 
1098 		if (ns == llcp_sock->recv_n)
1099 			llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
1100 		else
1101 			pr_err("Received out of sequence I PDU\n");
1102 
1103 		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
1104 		if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
1105 			/*
1106 			 * I frames will be freed from the socket layer, so we
1107 			 * need to keep them alive until someone receives them.
1108 			 */
1109 			skb_get(skb);
1110 		} else {
1111 			pr_err("Receive queue is full\n");
1112 		}
1113 	}
1114 
1115 	/* Remove skbs from the pending queue */
1116 	if (llcp_sock->send_ack_n != nr) {
1117 		struct sk_buff *s, *tmp;
1118 		u8 n;
1119 
1120 		llcp_sock->send_ack_n = nr;
1121 
1122 		/* Remove and free all skbs until ns == nr */
1123 		skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
1124 			n = nfc_llcp_ns(s);
1125 
1126 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1127 			kfree_skb(s);
1128 
1129 			if (n == nr)
1130 				break;
1131 		}
1132 
1133 		/* Re-queue the remaining skbs for transmission */
1134 		skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1135 					    s, tmp) {
1136 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1137 			skb_queue_head(&local->tx_queue, s);
1138 		}
1139 	}
1140 
1141 	if (ptype == LLCP_PDU_RR)
1142 		llcp_sock->remote_ready = true;
1143 	else if (ptype == LLCP_PDU_RNR)
1144 		llcp_sock->remote_ready = false;
1145 
1146 	if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1147 		nfc_llcp_send_rr(llcp_sock);
1148 
1149 	release_sock(sk);
1150 	nfc_llcp_sock_put(llcp_sock);
1151 }
1152 
1153 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1154 			       const struct sk_buff *skb)
1155 {
1156 	struct nfc_llcp_sock *llcp_sock;
1157 	struct sock *sk;
1158 	u8 dsap, ssap;
1159 
1160 	dsap = nfc_llcp_dsap(skb);
1161 	ssap = nfc_llcp_ssap(skb);
1162 
1163 	if ((dsap == 0) && (ssap == 0)) {
1164 		pr_debug("Connection termination");
1165 		nfc_dep_link_down(local->dev);
1166 		return;
1167 	}
1168 
1169 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1170 	if (llcp_sock == NULL) {
1171 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1172 		return;
1173 	}
1174 
1175 	sk = &llcp_sock->sk;
1176 	lock_sock(sk);
1177 
1178 	nfc_llcp_socket_purge(llcp_sock);
1179 
1180 	if (sk->sk_state == LLCP_CLOSED) {
1181 		release_sock(sk);
1182 		nfc_llcp_sock_put(llcp_sock);
1183 	}
1184 
1185 	if (sk->sk_state == LLCP_CONNECTED) {
1186 		nfc_put_device(local->dev);
1187 		sk->sk_state = LLCP_CLOSED;
1188 		sk->sk_state_change(sk);
1189 	}
1190 
1191 	nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1192 
1193 	release_sock(sk);
1194 	nfc_llcp_sock_put(llcp_sock);
1195 }
1196 
1197 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local,
1198 			     const struct sk_buff *skb)
1199 {
1200 	struct nfc_llcp_sock *llcp_sock;
1201 	struct sock *sk;
1202 	u8 dsap, ssap;
1203 
1204 	dsap = nfc_llcp_dsap(skb);
1205 	ssap = nfc_llcp_ssap(skb);
1206 
1207 	llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1208 	if (llcp_sock == NULL) {
1209 		pr_err("Invalid CC\n");
1210 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1211 
1212 		return;
1213 	}
1214 
1215 	sk = &llcp_sock->sk;
1216 
1217 	/* Unlink from connecting and link to the client array */
1218 	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1219 	nfc_llcp_sock_link(&local->sockets, sk);
1220 	llcp_sock->dsap = ssap;
1221 
1222 	nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1223 				      skb->len - LLCP_HEADER_SIZE);
1224 
1225 	sk->sk_state = LLCP_CONNECTED;
1226 	sk->sk_state_change(sk);
1227 
1228 	nfc_llcp_sock_put(llcp_sock);
1229 }
1230 
1231 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local,
1232 			     const struct sk_buff *skb)
1233 {
1234 	struct nfc_llcp_sock *llcp_sock;
1235 	struct sock *sk;
1236 	u8 dsap, ssap, reason;
1237 
1238 	dsap = nfc_llcp_dsap(skb);
1239 	ssap = nfc_llcp_ssap(skb);
1240 	reason = skb->data[2];
1241 
1242 	pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1243 
1244 	switch (reason) {
1245 	case LLCP_DM_NOBOUND:
1246 	case LLCP_DM_REJ:
1247 		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1248 		break;
1249 
1250 	default:
1251 		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1252 		break;
1253 	}
1254 
1255 	if (llcp_sock == NULL) {
1256 		pr_debug("Already closed\n");
1257 		return;
1258 	}
1259 
1260 	sk = &llcp_sock->sk;
1261 
1262 	sk->sk_err = ENXIO;
1263 	sk->sk_state = LLCP_CLOSED;
1264 	sk->sk_state_change(sk);
1265 
1266 	nfc_llcp_sock_put(llcp_sock);
1267 }
1268 
1269 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1270 			      const struct sk_buff *skb)
1271 {
1272 	struct nfc_llcp_sock *llcp_sock;
1273 	u8 dsap, ssap, type, length, tid, sap;
1274 	const u8 *tlv;
1275 	u16 tlv_len, offset;
1276 	const char *service_name;
1277 	size_t service_name_len;
1278 	struct nfc_llcp_sdp_tlv *sdp;
1279 	HLIST_HEAD(llc_sdres_list);
1280 	size_t sdres_tlvs_len;
1281 	HLIST_HEAD(nl_sdres_list);
1282 
1283 	dsap = nfc_llcp_dsap(skb);
1284 	ssap = nfc_llcp_ssap(skb);
1285 
1286 	pr_debug("%d %d\n", dsap, ssap);
1287 
1288 	if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1289 		pr_err("Wrong SNL SAP\n");
1290 		return;
1291 	}
1292 
1293 	tlv = &skb->data[LLCP_HEADER_SIZE];
1294 	tlv_len = skb->len - LLCP_HEADER_SIZE;
1295 	offset = 0;
1296 	sdres_tlvs_len = 0;
1297 
1298 	while (offset < tlv_len) {
1299 		type = tlv[0];
1300 		length = tlv[1];
1301 
1302 		switch (type) {
1303 		case LLCP_TLV_SDREQ:
1304 			tid = tlv[2];
1305 			service_name = (char *) &tlv[3];
1306 			service_name_len = length - 1;
1307 
1308 			pr_debug("Looking for %.16s\n", service_name);
1309 
1310 			if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1311 			    !strncmp(service_name, "urn:nfc:sn:sdp",
1312 				     service_name_len)) {
1313 				sap = 1;
1314 				goto add_snl;
1315 			}
1316 
1317 			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1318 							  service_name_len,
1319 							  true);
1320 			if (!llcp_sock) {
1321 				sap = 0;
1322 				goto add_snl;
1323 			}
1324 
1325 			/*
1326 			 * We found a socket but its ssap has not been reserved
1327 			 * yet. We need to assign it for good and send a reply.
1328 			 * The ssap will be freed when the socket is closed.
1329 			 */
1330 			if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1331 				atomic_t *client_count;
1332 
1333 				sap = nfc_llcp_reserve_sdp_ssap(local);
1334 
1335 				pr_debug("Reserving %d\n", sap);
1336 
1337 				if (sap == LLCP_SAP_MAX) {
1338 					sap = 0;
1339 					nfc_llcp_sock_put(llcp_sock);
1340 					goto add_snl;
1341 				}
1342 
1343 				client_count =
1344 					&local->local_sdp_cnt[sap -
1345 							      LLCP_WKS_NUM_SAP];
1346 
1347 				atomic_inc(client_count);
1348 
1349 				llcp_sock->ssap = sap;
1350 				llcp_sock->reserved_ssap = sap;
1351 			} else {
1352 				sap = llcp_sock->ssap;
1353 			}
1354 
1355 			pr_debug("%p %d\n", llcp_sock, sap);
1356 
1357 			nfc_llcp_sock_put(llcp_sock);
1358 add_snl:
1359 			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
1360 			if (sdp == NULL)
1361 				goto exit;
1362 
1363 			sdres_tlvs_len += sdp->tlv_len;
1364 			hlist_add_head(&sdp->node, &llc_sdres_list);
1365 			break;
1366 
1367 		case LLCP_TLV_SDRES:
1368 			mutex_lock(&local->sdreq_lock);
1369 
1370 			pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]);
1371 
1372 			hlist_for_each_entry(sdp, &local->pending_sdreqs, node) {
1373 				if (sdp->tid != tlv[2])
1374 					continue;
1375 
1376 				sdp->sap = tlv[3];
1377 
1378 				pr_debug("Found: uri=%s, sap=%d\n",
1379 					 sdp->uri, sdp->sap);
1380 
1381 				hlist_del(&sdp->node);
1382 
1383 				hlist_add_head(&sdp->node, &nl_sdres_list);
1384 
1385 				break;
1386 			}
1387 
1388 			mutex_unlock(&local->sdreq_lock);
1389 			break;
1390 
1391 		default:
1392 			pr_err("Invalid SNL tlv value 0x%x\n", type);
1393 			break;
1394 		}
1395 
1396 		offset += length + 2;
1397 		tlv += length + 2;
1398 	}
1399 
1400 exit:
1401 	if (!hlist_empty(&nl_sdres_list))
1402 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
1403 
1404 	if (!hlist_empty(&llc_sdres_list))
1405 		nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);
1406 }
1407 
1408 static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
1409 {
1410 	u8 ptype;
1411 	u16 pdu_len;
1412 	struct sk_buff *new_skb;
1413 
1414 	if (skb->len <= LLCP_HEADER_SIZE) {
1415 		pr_err("Malformed AGF PDU\n");
1416 		return;
1417 	}
1418 
1419 	skb_pull(skb, LLCP_HEADER_SIZE);
1420 
1421 	while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) {
1422 		pdu_len = skb->data[0] << 8 | skb->data[1];
1423 
1424 		skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE);
1425 
1426 		if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) {
1427 			pr_err("Malformed AGF PDU\n");
1428 			return;
1429 		}
1430 
1431 		ptype = nfc_llcp_ptype(skb);
1432 
1433 		if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF)
1434 			goto next;
1435 
1436 		new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
1437 		if (new_skb == NULL) {
1438 			pr_err("Could not allocate PDU\n");
1439 			return;
1440 		}
1441 
1442 		skb_put_data(new_skb, skb->data, pdu_len);
1443 
1444 		nfc_llcp_rx_skb(local, new_skb);
1445 
1446 		kfree_skb(new_skb);
1447 next:
1448 		skb_pull(skb, pdu_len);
1449 	}
1450 }
1451 
1452 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
1453 {
1454 	u8 dsap, ssap, ptype;
1455 
1456 	ptype = nfc_llcp_ptype(skb);
1457 	dsap = nfc_llcp_dsap(skb);
1458 	ssap = nfc_llcp_ssap(skb);
1459 
1460 	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1461 
1462 	if (ptype != LLCP_PDU_SYMM)
1463 		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
1464 				     skb->data, skb->len, true);
1465 
1466 	switch (ptype) {
1467 	case LLCP_PDU_SYMM:
1468 		pr_debug("SYMM\n");
1469 		break;
1470 
1471 	case LLCP_PDU_UI:
1472 		pr_debug("UI\n");
1473 		nfc_llcp_recv_ui(local, skb);
1474 		break;
1475 
1476 	case LLCP_PDU_CONNECT:
1477 		pr_debug("CONNECT\n");
1478 		nfc_llcp_recv_connect(local, skb);
1479 		break;
1480 
1481 	case LLCP_PDU_DISC:
1482 		pr_debug("DISC\n");
1483 		nfc_llcp_recv_disc(local, skb);
1484 		break;
1485 
1486 	case LLCP_PDU_CC:
1487 		pr_debug("CC\n");
1488 		nfc_llcp_recv_cc(local, skb);
1489 		break;
1490 
1491 	case LLCP_PDU_DM:
1492 		pr_debug("DM\n");
1493 		nfc_llcp_recv_dm(local, skb);
1494 		break;
1495 
1496 	case LLCP_PDU_SNL:
1497 		pr_debug("SNL\n");
1498 		nfc_llcp_recv_snl(local, skb);
1499 		break;
1500 
1501 	case LLCP_PDU_I:
1502 	case LLCP_PDU_RR:
1503 	case LLCP_PDU_RNR:
1504 		pr_debug("I frame\n");
1505 		nfc_llcp_recv_hdlc(local, skb);
1506 		break;
1507 
1508 	case LLCP_PDU_AGF:
1509 		pr_debug("AGF frame\n");
1510 		nfc_llcp_recv_agf(local, skb);
1511 		break;
1512 	}
1513 }
1514 
1515 static void nfc_llcp_rx_work(struct work_struct *work)
1516 {
1517 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1518 						    rx_work);
1519 	struct sk_buff *skb;
1520 
1521 	skb = local->rx_pending;
1522 	if (skb == NULL) {
1523 		pr_debug("No pending SKB\n");
1524 		return;
1525 	}
1526 
1527 	__net_timestamp(skb);
1528 
1529 	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);
1530 
1531 	nfc_llcp_rx_skb(local, skb);
1532 
1533 	schedule_work(&local->tx_work);
1534 	kfree_skb(local->rx_pending);
1535 	local->rx_pending = NULL;
1536 }
1537 
1538 static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
1539 {
1540 	local->rx_pending = skb;
1541 	timer_delete(&local->link_timer);
1542 	schedule_work(&local->rx_work);
1543 }
1544 
1545 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1546 {
1547 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1548 
1549 	if (err < 0) {
1550 		pr_err("LLCP PDU receive err %d\n", err);
1551 		return;
1552 	}
1553 
1554 	__nfc_llcp_recv(local, skb);
1555 }
1556 
1557 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1558 {
1559 	struct nfc_llcp_local *local;
1560 
1561 	local = nfc_llcp_find_local(dev);
1562 	if (local == NULL) {
1563 		kfree_skb(skb);
1564 		return -ENODEV;
1565 	}
1566 
1567 	__nfc_llcp_recv(local, skb);
1568 
1569 	nfc_llcp_local_put(local);
1570 
1571 	return 0;
1572 }
1573 
1574 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1575 {
1576 	struct nfc_llcp_local *local;
1577 
1578 	local = nfc_llcp_find_local(dev);
1579 	if (local == NULL)
1580 		return;
1581 
1582 	local->remote_miu = LLCP_DEFAULT_MIU;
1583 	local->remote_lto = LLCP_DEFAULT_LTO;
1584 
1585 	/* Close and purge all existing sockets */
1586 	nfc_llcp_socket_release(local, true, 0);
1587 
1588 	nfc_llcp_local_put(local);
1589 }
1590 
1591 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1592 			u8 comm_mode, u8 rf_mode)
1593 {
1594 	struct nfc_llcp_local *local;
1595 
1596 	pr_debug("rf mode %d\n", rf_mode);
1597 
1598 	local = nfc_llcp_find_local(dev);
1599 	if (local == NULL)
1600 		return;
1601 
1602 	local->target_idx = target_idx;
1603 	local->comm_mode = comm_mode;
1604 	local->rf_mode = rf_mode;
1605 
1606 	if (rf_mode == NFC_RF_INITIATOR) {
1607 		pr_debug("Queueing Tx work\n");
1608 
1609 		schedule_work(&local->tx_work);
1610 	} else {
1611 		mod_timer(&local->link_timer,
1612 			  jiffies + msecs_to_jiffies(local->remote_lto));
1613 	}
1614 
1615 	nfc_llcp_local_put(local);
1616 }
1617 
1618 int nfc_llcp_register_device(struct nfc_dev *ndev)
1619 {
1620 	struct nfc_llcp_local *local;
1621 
1622 	local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1623 	if (local == NULL)
1624 		return -ENOMEM;
1625 
1626 	/* As we are going to initialize local's refcount, we need to get the
1627 	 * nfc_dev to avoid UAF, otherwise there is no point in continuing.
1628 	 * See nfc_llcp_local_get().
1629 	 */
1630 	local->dev = nfc_get_device(ndev->idx);
1631 	if (!local->dev) {
1632 		kfree(local);
1633 		return -ENODEV;
1634 	}
1635 
1636 	INIT_LIST_HEAD(&local->list);
1637 	kref_init(&local->ref);
1638 	mutex_init(&local->sdp_lock);
1639 	timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0);
1640 
1641 	skb_queue_head_init(&local->tx_queue);
1642 	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1643 
1644 	local->rx_pending = NULL;
1645 	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1646 
1647 	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1648 
1649 	rwlock_init(&local->sockets.lock);
1650 	rwlock_init(&local->connecting_sockets.lock);
1651 	rwlock_init(&local->raw_sockets.lock);
1652 
1653 	local->lto = 150; /* 1500 ms */
1654 	local->rw = LLCP_MAX_RW;
1655 	local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1656 	local->local_wks = 0x1; /* LLC Link Management */
1657 
1658 	nfc_llcp_build_gb(local);
1659 
1660 	local->remote_miu = LLCP_DEFAULT_MIU;
1661 	local->remote_lto = LLCP_DEFAULT_LTO;
1662 
1663 	mutex_init(&local->sdreq_lock);
1664 	INIT_HLIST_HEAD(&local->pending_sdreqs);
1665 	timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0);
1666 	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
1667 
1668 	spin_lock(&llcp_devices_lock);
1669 	list_add(&local->list, &llcp_devices);
1670 	spin_unlock(&llcp_devices_lock);
1671 
1672 	return 0;
1673 }
1674 
1675 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1676 {
1677 	struct nfc_llcp_local *local = nfc_llcp_remove_local(dev);
1678 
1679 	if (local == NULL) {
1680 		pr_debug("No such device\n");
1681 		return;
1682 	}
1683 
1684 	local_cleanup(local);
1685 
1686 	nfc_llcp_local_put(local);
1687 }
1688 
1689 int __init nfc_llcp_init(void)
1690 {
1691 	return nfc_llcp_sock_init();
1692 }
1693 
1694 void nfc_llcp_exit(void)
1695 {
1696 	nfc_llcp_sock_exit();
1697 }
1698