xref: /linux/net/nfc/llcp_core.c (revision aec2f682d47c54ef434b2d440992626d80b1ebdc)
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 			spin_lock(&local->tx_queue.lock);
320 			list_del_init(&local->list);
321 			spin_unlock(&local->tx_queue.lock);
322 			spin_unlock(&llcp_devices_lock);
323 			return local;
324 		}
325 	spin_unlock(&llcp_devices_lock);
326 
327 	pr_warn("Shutting down device not found\n");
328 
329 	return NULL;
330 }
331 
332 static char *wks[] = {
333 	NULL,
334 	NULL, /* SDP */
335 	"urn:nfc:sn:ip",
336 	"urn:nfc:sn:obex",
337 	"urn:nfc:sn:snep",
338 };
339 
340 static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len)
341 {
342 	int sap, num_wks;
343 
344 	pr_debug("%s\n", service_name);
345 
346 	if (service_name == NULL)
347 		return -EINVAL;
348 
349 	num_wks = ARRAY_SIZE(wks);
350 
351 	for (sap = 0; sap < num_wks; sap++) {
352 		if (wks[sap] == NULL)
353 			continue;
354 
355 		if (strncmp(wks[sap], service_name, service_name_len) == 0)
356 			return sap;
357 	}
358 
359 	return -EINVAL;
360 }
361 
362 static
363 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
364 					    const u8 *sn, size_t sn_len,
365 					    bool needref)
366 {
367 	struct sock *sk;
368 	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
369 
370 	pr_debug("sn %zd %p\n", sn_len, sn);
371 
372 	if (sn == NULL || sn_len == 0)
373 		return NULL;
374 
375 	read_lock(&local->sockets.lock);
376 
377 	llcp_sock = NULL;
378 
379 	sk_for_each(sk, &local->sockets.head) {
380 		tmp_sock = nfc_llcp_sock(sk);
381 
382 		pr_debug("llcp sock %p\n", tmp_sock);
383 
384 		if (tmp_sock->sk.sk_type == SOCK_STREAM &&
385 		    tmp_sock->sk.sk_state != LLCP_LISTEN)
386 			continue;
387 
388 		if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
389 		    tmp_sock->sk.sk_state != LLCP_BOUND)
390 			continue;
391 
392 		if (tmp_sock->service_name == NULL ||
393 		    tmp_sock->service_name_len == 0)
394 			continue;
395 
396 		if (tmp_sock->service_name_len != sn_len)
397 			continue;
398 
399 		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
400 			llcp_sock = tmp_sock;
401 			if (needref)
402 				sock_hold(&llcp_sock->sk);
403 			break;
404 		}
405 	}
406 
407 	read_unlock(&local->sockets.lock);
408 
409 	pr_debug("Found llcp sock %p\n", llcp_sock);
410 
411 	return llcp_sock;
412 }
413 
414 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
415 			 struct nfc_llcp_sock *sock)
416 {
417 	mutex_lock(&local->sdp_lock);
418 
419 	if (sock->service_name != NULL && sock->service_name_len > 0) {
420 		int ssap = nfc_llcp_wks_sap(sock->service_name,
421 					    sock->service_name_len);
422 
423 		if (ssap > 0) {
424 			pr_debug("WKS %d\n", ssap);
425 
426 			/* This is a WKS, let's check if it's free */
427 			if (test_bit(ssap, &local->local_wks)) {
428 				mutex_unlock(&local->sdp_lock);
429 
430 				return LLCP_SAP_MAX;
431 			}
432 
433 			set_bit(ssap, &local->local_wks);
434 			mutex_unlock(&local->sdp_lock);
435 
436 			return ssap;
437 		}
438 
439 		/*
440 		 * Check if there already is a non WKS socket bound
441 		 * to this service name.
442 		 */
443 		if (nfc_llcp_sock_from_sn(local, sock->service_name,
444 					  sock->service_name_len,
445 					  false) != NULL) {
446 			mutex_unlock(&local->sdp_lock);
447 
448 			return LLCP_SAP_MAX;
449 		}
450 
451 		mutex_unlock(&local->sdp_lock);
452 
453 		return LLCP_SDP_UNBOUND;
454 
455 	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
456 		if (!test_bit(sock->ssap, &local->local_wks)) {
457 			set_bit(sock->ssap, &local->local_wks);
458 			mutex_unlock(&local->sdp_lock);
459 
460 			return sock->ssap;
461 		}
462 	}
463 
464 	mutex_unlock(&local->sdp_lock);
465 
466 	return LLCP_SAP_MAX;
467 }
468 
469 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
470 {
471 	u8 local_ssap;
472 
473 	mutex_lock(&local->sdp_lock);
474 
475 	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
476 	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
477 		mutex_unlock(&local->sdp_lock);
478 		return LLCP_SAP_MAX;
479 	}
480 
481 	set_bit(local_ssap, &local->local_sap);
482 
483 	mutex_unlock(&local->sdp_lock);
484 
485 	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
486 }
487 
488 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
489 {
490 	u8 local_ssap;
491 	unsigned long *sdp;
492 
493 	if (ssap < LLCP_WKS_NUM_SAP) {
494 		local_ssap = ssap;
495 		sdp = &local->local_wks;
496 	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
497 		atomic_t *client_cnt;
498 
499 		local_ssap = ssap - LLCP_WKS_NUM_SAP;
500 		sdp = &local->local_sdp;
501 		client_cnt = &local->local_sdp_cnt[local_ssap];
502 
503 		pr_debug("%d clients\n", atomic_read(client_cnt));
504 
505 		mutex_lock(&local->sdp_lock);
506 
507 		if (atomic_dec_and_test(client_cnt)) {
508 			struct nfc_llcp_sock *l_sock;
509 
510 			pr_debug("No more clients for SAP %d\n", ssap);
511 
512 			clear_bit(local_ssap, sdp);
513 
514 			/* Find the listening sock and set it back to UNBOUND */
515 			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
516 			if (l_sock) {
517 				l_sock->ssap = LLCP_SDP_UNBOUND;
518 				nfc_llcp_sock_put(l_sock);
519 			}
520 		}
521 
522 		mutex_unlock(&local->sdp_lock);
523 
524 		return;
525 	} else if (ssap < LLCP_MAX_SAP) {
526 		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
527 		sdp = &local->local_sap;
528 	} else {
529 		return;
530 	}
531 
532 	mutex_lock(&local->sdp_lock);
533 
534 	clear_bit(local_ssap, sdp);
535 
536 	mutex_unlock(&local->sdp_lock);
537 }
538 
539 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
540 {
541 	u8 ssap;
542 
543 	mutex_lock(&local->sdp_lock);
544 
545 	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
546 	if (ssap == LLCP_SDP_NUM_SAP) {
547 		mutex_unlock(&local->sdp_lock);
548 
549 		return LLCP_SAP_MAX;
550 	}
551 
552 	pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
553 
554 	set_bit(ssap, &local->local_sdp);
555 
556 	mutex_unlock(&local->sdp_lock);
557 
558 	return LLCP_WKS_NUM_SAP + ssap;
559 }
560 
561 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
562 {
563 	u8 *gb_cur, version, version_length;
564 	u8 lto_length, wks_length, miux_length;
565 	const u8 *version_tlv = NULL, *lto_tlv = NULL,
566 	   *wks_tlv = NULL, *miux_tlv = NULL;
567 	__be16 wks = cpu_to_be16(local->local_wks);
568 	u8 gb_len = 0;
569 	int ret = 0;
570 
571 	version = LLCP_VERSION_11;
572 	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
573 					 1, &version_length);
574 	if (!version_tlv) {
575 		ret = -ENOMEM;
576 		goto out;
577 	}
578 	gb_len += version_length;
579 
580 	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
581 	if (!lto_tlv) {
582 		ret = -ENOMEM;
583 		goto out;
584 	}
585 	gb_len += lto_length;
586 
587 	pr_debug("Local wks 0x%lx\n", local->local_wks);
588 	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
589 	if (!wks_tlv) {
590 		ret = -ENOMEM;
591 		goto out;
592 	}
593 	gb_len += wks_length;
594 
595 	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
596 				      &miux_length);
597 	if (!miux_tlv) {
598 		ret = -ENOMEM;
599 		goto out;
600 	}
601 	gb_len += miux_length;
602 
603 	gb_len += ARRAY_SIZE(llcp_magic);
604 
605 	if (gb_len > NFC_MAX_GT_LEN) {
606 		ret = -EINVAL;
607 		goto out;
608 	}
609 
610 	gb_cur = local->gb;
611 
612 	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
613 	gb_cur += ARRAY_SIZE(llcp_magic);
614 
615 	memcpy(gb_cur, version_tlv, version_length);
616 	gb_cur += version_length;
617 
618 	memcpy(gb_cur, lto_tlv, lto_length);
619 	gb_cur += lto_length;
620 
621 	memcpy(gb_cur, wks_tlv, wks_length);
622 	gb_cur += wks_length;
623 
624 	memcpy(gb_cur, miux_tlv, miux_length);
625 	gb_cur += miux_length;
626 
627 	local->gb_len = gb_len;
628 
629 out:
630 	kfree(version_tlv);
631 	kfree(lto_tlv);
632 	kfree(wks_tlv);
633 	kfree(miux_tlv);
634 
635 	return ret;
636 }
637 
638 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
639 {
640 	struct nfc_llcp_local *local;
641 
642 	local = nfc_llcp_find_local(dev);
643 	if (local == NULL) {
644 		*general_bytes_len = 0;
645 		return NULL;
646 	}
647 
648 	nfc_llcp_build_gb(local);
649 
650 	*general_bytes_len = local->gb_len;
651 
652 	nfc_llcp_local_put(local);
653 
654 	return local->gb;
655 }
656 
657 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, const u8 *gb, u8 gb_len)
658 {
659 	struct nfc_llcp_local *local;
660 	int err;
661 
662 	if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
663 		return -EINVAL;
664 
665 	local = nfc_llcp_find_local(dev);
666 	if (local == NULL) {
667 		pr_err("No LLCP device\n");
668 		return -ENODEV;
669 	}
670 
671 	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
672 	memcpy(local->remote_gb, gb, gb_len);
673 	local->remote_gb_len = gb_len;
674 
675 	if (memcmp(local->remote_gb, llcp_magic, 3)) {
676 		pr_err("MAC does not support LLCP\n");
677 		err = -EINVAL;
678 		goto out;
679 	}
680 
681 	err = nfc_llcp_parse_gb_tlv(local,
682 				     &local->remote_gb[3],
683 				     local->remote_gb_len - 3);
684 out:
685 	nfc_llcp_local_put(local);
686 	return err;
687 }
688 
689 static u8 nfc_llcp_dsap(const struct sk_buff *pdu)
690 {
691 	return (pdu->data[0] & 0xfc) >> 2;
692 }
693 
694 static u8 nfc_llcp_ptype(const struct sk_buff *pdu)
695 {
696 	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
697 }
698 
699 static u8 nfc_llcp_ssap(const struct sk_buff *pdu)
700 {
701 	return pdu->data[1] & 0x3f;
702 }
703 
704 static u8 nfc_llcp_ns(const struct sk_buff *pdu)
705 {
706 	return pdu->data[2] >> 4;
707 }
708 
709 static u8 nfc_llcp_nr(const struct sk_buff *pdu)
710 {
711 	return pdu->data[2] & 0xf;
712 }
713 
714 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
715 {
716 	pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
717 	sock->send_n = (sock->send_n + 1) % 16;
718 	sock->recv_ack_n = (sock->recv_n - 1) % 16;
719 }
720 
721 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
722 			       struct sk_buff *skb, u8 direction)
723 {
724 	struct sk_buff *skb_copy = NULL, *nskb;
725 	struct sock *sk;
726 	u8 *data;
727 
728 	read_lock(&local->raw_sockets.lock);
729 
730 	sk_for_each(sk, &local->raw_sockets.head) {
731 		if (sk->sk_state != LLCP_BOUND)
732 			continue;
733 
734 		if (skb_copy == NULL) {
735 			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
736 						      GFP_ATOMIC, true);
737 
738 			if (skb_copy == NULL)
739 				continue;
740 
741 			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
742 
743 			data[0] = local->dev ? local->dev->idx : 0xFF;
744 			data[1] = direction & 0x01;
745 			data[1] |= (RAW_PAYLOAD_LLCP << 1);
746 		}
747 
748 		nskb = skb_clone(skb_copy, GFP_ATOMIC);
749 		if (!nskb)
750 			continue;
751 
752 		if (sock_queue_rcv_skb(sk, nskb))
753 			kfree_skb(nskb);
754 	}
755 
756 	read_unlock(&local->raw_sockets.lock);
757 
758 	kfree_skb(skb_copy);
759 }
760 
761 static void nfc_llcp_tx_work(struct work_struct *work)
762 {
763 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
764 						    tx_work);
765 	struct sk_buff *skb;
766 	struct sock *sk;
767 	struct nfc_llcp_sock *llcp_sock;
768 
769 	skb = skb_dequeue(&local->tx_queue);
770 	if (skb != NULL) {
771 		sk = skb->sk;
772 		llcp_sock = nfc_llcp_sock(sk);
773 
774 		if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
775 			kfree_skb(skb);
776 			nfc_llcp_send_symm(local->dev);
777 		} else if (llcp_sock && !llcp_sock->remote_ready) {
778 			skb_queue_head(&local->tx_queue, skb);
779 			nfc_llcp_send_symm(local->dev);
780 		} else {
781 			struct sk_buff *copy_skb = NULL;
782 			u8 ptype = nfc_llcp_ptype(skb);
783 			int ret;
784 
785 			pr_debug("Sending pending skb\n");
786 			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
787 					     16, 1, skb->data, skb->len, true);
788 
789 			if (ptype == LLCP_PDU_I)
790 				copy_skb = skb_copy(skb, GFP_ATOMIC);
791 
792 			__net_timestamp(skb);
793 
794 			nfc_llcp_send_to_raw_sock(local, skb,
795 						  NFC_DIRECTION_TX);
796 
797 			ret = nfc_data_exchange(local->dev, local->target_idx,
798 						skb, nfc_llcp_recv, local);
799 
800 			if (ret) {
801 				kfree_skb(copy_skb);
802 				goto out;
803 			}
804 
805 			if (ptype == LLCP_PDU_I && copy_skb)
806 				skb_queue_tail(&llcp_sock->tx_pending_queue,
807 					       copy_skb);
808 		}
809 	} else {
810 		nfc_llcp_send_symm(local->dev);
811 	}
812 
813 out:
814 	mod_timer(&local->link_timer,
815 		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
816 }
817 
818 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
819 							  u8 ssap)
820 {
821 	struct sock *sk;
822 	struct nfc_llcp_sock *llcp_sock;
823 
824 	read_lock(&local->connecting_sockets.lock);
825 
826 	sk_for_each(sk, &local->connecting_sockets.head) {
827 		llcp_sock = nfc_llcp_sock(sk);
828 
829 		if (llcp_sock->ssap == ssap) {
830 			sock_hold(&llcp_sock->sk);
831 			goto out;
832 		}
833 	}
834 
835 	llcp_sock = NULL;
836 
837 out:
838 	read_unlock(&local->connecting_sockets.lock);
839 
840 	return llcp_sock;
841 }
842 
843 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
844 						  const u8 *sn, size_t sn_len)
845 {
846 	return nfc_llcp_sock_from_sn(local, sn, sn_len, true);
847 }
848 
849 static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
850 {
851 	u8 type, length;
852 	const u8 *tlv = &skb->data[2];
853 	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
854 
855 	while (offset < tlv_array_len) {
856 		type = tlv[0];
857 		length = tlv[1];
858 
859 		pr_debug("type 0x%x length %d\n", type, length);
860 
861 		if (type == LLCP_TLV_SN) {
862 			*sn_len = length;
863 			return &tlv[2];
864 		}
865 
866 		offset += length + 2;
867 		tlv += length + 2;
868 	}
869 
870 	return NULL;
871 }
872 
873 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
874 			     struct sk_buff *skb)
875 {
876 	struct nfc_llcp_sock *llcp_sock;
877 	struct nfc_llcp_ui_cb *ui_cb;
878 	u8 dsap, ssap;
879 
880 	dsap = nfc_llcp_dsap(skb);
881 	ssap = nfc_llcp_ssap(skb);
882 
883 	ui_cb = nfc_llcp_ui_skb_cb(skb);
884 	ui_cb->dsap = dsap;
885 	ui_cb->ssap = ssap;
886 
887 	pr_debug("%d %d\n", dsap, ssap);
888 
889 	/* We're looking for a bound socket, not a client one */
890 	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
891 	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
892 		return;
893 
894 	/* There is no sequence with UI frames */
895 	skb_pull(skb, LLCP_HEADER_SIZE);
896 	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
897 		/*
898 		 * UI frames will be freed from the socket layer, so we
899 		 * need to keep them alive until someone receives them.
900 		 */
901 		skb_get(skb);
902 	} else {
903 		pr_err("Receive queue is full\n");
904 	}
905 
906 	nfc_llcp_sock_put(llcp_sock);
907 }
908 
909 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
910 				  const struct sk_buff *skb)
911 {
912 	struct sock *new_sk, *parent;
913 	struct nfc_llcp_sock *sock, *new_sock;
914 	u8 dsap, ssap, reason;
915 
916 	dsap = nfc_llcp_dsap(skb);
917 	ssap = nfc_llcp_ssap(skb);
918 
919 	pr_debug("%d %d\n", dsap, ssap);
920 
921 	if (dsap != LLCP_SAP_SDP) {
922 		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
923 		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
924 			reason = LLCP_DM_NOBOUND;
925 			goto fail;
926 		}
927 	} else {
928 		const u8 *sn;
929 		size_t sn_len;
930 
931 		sn = nfc_llcp_connect_sn(skb, &sn_len);
932 		if (sn == NULL) {
933 			reason = LLCP_DM_NOBOUND;
934 			goto fail;
935 		}
936 
937 		pr_debug("Service name length %zu\n", sn_len);
938 
939 		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
940 		if (sock == NULL) {
941 			reason = LLCP_DM_NOBOUND;
942 			goto fail;
943 		}
944 	}
945 
946 	lock_sock(&sock->sk);
947 
948 	parent = &sock->sk;
949 
950 	if (sk_acceptq_is_full(parent)) {
951 		reason = LLCP_DM_REJ;
952 		release_sock(&sock->sk);
953 		sock_put(&sock->sk);
954 		goto fail;
955 	}
956 
957 	if (sock->ssap == LLCP_SDP_UNBOUND) {
958 		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
959 
960 		pr_debug("First client, reserving %d\n", ssap);
961 
962 		if (ssap == LLCP_SAP_MAX) {
963 			reason = LLCP_DM_REJ;
964 			release_sock(&sock->sk);
965 			sock_put(&sock->sk);
966 			goto fail;
967 		}
968 
969 		sock->ssap = ssap;
970 	}
971 
972 	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
973 	if (new_sk == NULL) {
974 		reason = LLCP_DM_REJ;
975 		release_sock(&sock->sk);
976 		sock_put(&sock->sk);
977 		goto fail;
978 	}
979 
980 	new_sock = nfc_llcp_sock(new_sk);
981 
982 	new_sock->local = nfc_llcp_local_get(local);
983 	if (!new_sock->local) {
984 		reason = LLCP_DM_REJ;
985 		sock_put(&new_sock->sk);
986 		release_sock(&sock->sk);
987 		sock_put(&sock->sk);
988 		goto fail;
989 	}
990 
991 	new_sock->dev = local->dev;
992 	new_sock->rw = sock->rw;
993 	new_sock->miux = sock->miux;
994 	new_sock->nfc_protocol = sock->nfc_protocol;
995 	new_sock->dsap = ssap;
996 	new_sock->target_idx = local->target_idx;
997 	new_sock->parent = parent;
998 	new_sock->ssap = sock->ssap;
999 	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
1000 		atomic_t *client_count;
1001 
1002 		pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
1003 
1004 		client_count =
1005 			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
1006 
1007 		atomic_inc(client_count);
1008 		new_sock->reserved_ssap = sock->ssap;
1009 	}
1010 
1011 	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
1012 				      skb->len - LLCP_HEADER_SIZE);
1013 
1014 	pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
1015 
1016 	nfc_llcp_sock_link(&local->sockets, new_sk);
1017 
1018 	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
1019 
1020 	nfc_get_device(local->dev->idx);
1021 
1022 	new_sk->sk_state = LLCP_CONNECTED;
1023 
1024 	/* Wake the listening processes */
1025 	parent->sk_data_ready(parent);
1026 
1027 	/* Send CC */
1028 	nfc_llcp_send_cc(new_sock);
1029 
1030 	release_sock(&sock->sk);
1031 	sock_put(&sock->sk);
1032 
1033 	return;
1034 
1035 fail:
1036 	/* Send DM */
1037 	nfc_llcp_send_dm(local, dsap, ssap, reason);
1038 }
1039 
1040 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
1041 {
1042 	int nr_frames = 0;
1043 	struct nfc_llcp_local *local = sock->local;
1044 
1045 	pr_debug("Remote ready %d tx queue len %d remote rw %d",
1046 		 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
1047 		 sock->remote_rw);
1048 
1049 	/* Try to queue some I frames for transmission */
1050 	while (sock->remote_ready &&
1051 	       skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {
1052 		struct sk_buff *pdu;
1053 
1054 		pdu = skb_dequeue(&sock->tx_queue);
1055 		if (pdu == NULL)
1056 			break;
1057 
1058 		/* Update N(S)/N(R) */
1059 		nfc_llcp_set_nrns(sock, pdu);
1060 
1061 		skb_queue_tail(&local->tx_queue, pdu);
1062 		nr_frames++;
1063 	}
1064 
1065 	return nr_frames;
1066 }
1067 
1068 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
1069 			       struct sk_buff *skb)
1070 {
1071 	struct nfc_llcp_sock *llcp_sock;
1072 	struct sock *sk;
1073 	u8 dsap, ssap, ptype, ns, nr;
1074 
1075 	ptype = nfc_llcp_ptype(skb);
1076 	dsap = nfc_llcp_dsap(skb);
1077 	ssap = nfc_llcp_ssap(skb);
1078 	ns = nfc_llcp_ns(skb);
1079 	nr = nfc_llcp_nr(skb);
1080 
1081 	pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
1082 
1083 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1084 	if (llcp_sock == NULL) {
1085 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1086 		return;
1087 	}
1088 
1089 	sk = &llcp_sock->sk;
1090 	lock_sock(sk);
1091 	if (sk->sk_state == LLCP_CLOSED) {
1092 		release_sock(sk);
1093 		nfc_llcp_sock_put(llcp_sock);
1094 		return;
1095 	}
1096 
1097 	/* Pass the payload upstream */
1098 	if (ptype == LLCP_PDU_I) {
1099 		pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
1100 
1101 		if (ns == llcp_sock->recv_n)
1102 			llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
1103 		else
1104 			pr_err("Received out of sequence I PDU\n");
1105 
1106 		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
1107 		if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
1108 			/*
1109 			 * I frames will be freed from the socket layer, so we
1110 			 * need to keep them alive until someone receives them.
1111 			 */
1112 			skb_get(skb);
1113 		} else {
1114 			pr_err("Receive queue is full\n");
1115 		}
1116 	}
1117 
1118 	/* Remove skbs from the pending queue */
1119 	if (llcp_sock->send_ack_n != nr) {
1120 		struct sk_buff *s, *tmp;
1121 		u8 n;
1122 
1123 		llcp_sock->send_ack_n = nr;
1124 
1125 		/* Remove and free all skbs until ns == nr */
1126 		skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
1127 			n = nfc_llcp_ns(s);
1128 
1129 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1130 			kfree_skb(s);
1131 
1132 			if (n == nr)
1133 				break;
1134 		}
1135 
1136 		/* Re-queue the remaining skbs for transmission */
1137 		skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1138 					    s, tmp) {
1139 			skb_unlink(s, &llcp_sock->tx_pending_queue);
1140 			skb_queue_head(&local->tx_queue, s);
1141 		}
1142 	}
1143 
1144 	if (ptype == LLCP_PDU_RR)
1145 		llcp_sock->remote_ready = true;
1146 	else if (ptype == LLCP_PDU_RNR)
1147 		llcp_sock->remote_ready = false;
1148 
1149 	if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1150 		nfc_llcp_send_rr(llcp_sock);
1151 
1152 	release_sock(sk);
1153 	nfc_llcp_sock_put(llcp_sock);
1154 }
1155 
1156 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1157 			       const struct sk_buff *skb)
1158 {
1159 	struct nfc_llcp_sock *llcp_sock;
1160 	struct sock *sk;
1161 	u8 dsap, ssap;
1162 
1163 	dsap = nfc_llcp_dsap(skb);
1164 	ssap = nfc_llcp_ssap(skb);
1165 
1166 	if ((dsap == 0) && (ssap == 0)) {
1167 		pr_debug("Connection termination");
1168 		nfc_dep_link_down(local->dev);
1169 		return;
1170 	}
1171 
1172 	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1173 	if (llcp_sock == NULL) {
1174 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1175 		return;
1176 	}
1177 
1178 	sk = &llcp_sock->sk;
1179 	lock_sock(sk);
1180 
1181 	nfc_llcp_socket_purge(llcp_sock);
1182 
1183 	if (sk->sk_state == LLCP_CLOSED) {
1184 		release_sock(sk);
1185 		nfc_llcp_sock_put(llcp_sock);
1186 		return;
1187 	}
1188 
1189 	if (sk->sk_state == LLCP_CONNECTED) {
1190 		nfc_put_device(local->dev);
1191 		sk->sk_state = LLCP_CLOSED;
1192 		sk->sk_state_change(sk);
1193 	}
1194 
1195 	nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1196 
1197 	release_sock(sk);
1198 	nfc_llcp_sock_put(llcp_sock);
1199 }
1200 
1201 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local,
1202 			     const struct sk_buff *skb)
1203 {
1204 	struct nfc_llcp_sock *llcp_sock;
1205 	struct sock *sk;
1206 	u8 dsap, ssap;
1207 
1208 	dsap = nfc_llcp_dsap(skb);
1209 	ssap = nfc_llcp_ssap(skb);
1210 
1211 	llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1212 	if (llcp_sock == NULL) {
1213 		pr_err("Invalid CC\n");
1214 		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1215 
1216 		return;
1217 	}
1218 
1219 	sk = &llcp_sock->sk;
1220 
1221 	/* Unlink from connecting and link to the client array */
1222 	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1223 	nfc_llcp_sock_link(&local->sockets, sk);
1224 	llcp_sock->dsap = ssap;
1225 
1226 	nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1227 				      skb->len - LLCP_HEADER_SIZE);
1228 
1229 	sk->sk_state = LLCP_CONNECTED;
1230 	sk->sk_state_change(sk);
1231 
1232 	nfc_llcp_sock_put(llcp_sock);
1233 }
1234 
1235 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local,
1236 			     const struct sk_buff *skb)
1237 {
1238 	struct nfc_llcp_sock *llcp_sock;
1239 	struct sock *sk;
1240 	u8 dsap, ssap, reason;
1241 
1242 	dsap = nfc_llcp_dsap(skb);
1243 	ssap = nfc_llcp_ssap(skb);
1244 	reason = skb->data[2];
1245 
1246 	pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1247 
1248 	switch (reason) {
1249 	case LLCP_DM_NOBOUND:
1250 	case LLCP_DM_REJ:
1251 		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1252 		break;
1253 
1254 	default:
1255 		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1256 		break;
1257 	}
1258 
1259 	if (llcp_sock == NULL) {
1260 		pr_debug("Already closed\n");
1261 		return;
1262 	}
1263 
1264 	sk = &llcp_sock->sk;
1265 
1266 	sk->sk_err = ENXIO;
1267 	sk->sk_state = LLCP_CLOSED;
1268 	sk->sk_state_change(sk);
1269 
1270 	nfc_llcp_sock_put(llcp_sock);
1271 }
1272 
1273 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1274 			      const struct sk_buff *skb)
1275 {
1276 	struct nfc_llcp_sock *llcp_sock;
1277 	u8 dsap, ssap, type, length, tid, sap;
1278 	const u8 *tlv;
1279 	u16 tlv_len, offset;
1280 	const char *service_name;
1281 	size_t service_name_len;
1282 	struct nfc_llcp_sdp_tlv *sdp;
1283 	HLIST_HEAD(llc_sdres_list);
1284 	size_t sdres_tlvs_len;
1285 	HLIST_HEAD(nl_sdres_list);
1286 
1287 	dsap = nfc_llcp_dsap(skb);
1288 	ssap = nfc_llcp_ssap(skb);
1289 
1290 	pr_debug("%d %d\n", dsap, ssap);
1291 
1292 	if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1293 		pr_err("Wrong SNL SAP\n");
1294 		return;
1295 	}
1296 
1297 	tlv = &skb->data[LLCP_HEADER_SIZE];
1298 	tlv_len = skb->len - LLCP_HEADER_SIZE;
1299 	offset = 0;
1300 	sdres_tlvs_len = 0;
1301 
1302 	while (offset < tlv_len) {
1303 		type = tlv[0];
1304 		length = tlv[1];
1305 
1306 		switch (type) {
1307 		case LLCP_TLV_SDREQ:
1308 			tid = tlv[2];
1309 			service_name = (char *) &tlv[3];
1310 			service_name_len = length - 1;
1311 
1312 			pr_debug("Looking for %.16s\n", service_name);
1313 
1314 			if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1315 			    !strncmp(service_name, "urn:nfc:sn:sdp",
1316 				     service_name_len)) {
1317 				sap = 1;
1318 				goto add_snl;
1319 			}
1320 
1321 			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1322 							  service_name_len,
1323 							  true);
1324 			if (!llcp_sock) {
1325 				sap = 0;
1326 				goto add_snl;
1327 			}
1328 
1329 			/*
1330 			 * We found a socket but its ssap has not been reserved
1331 			 * yet. We need to assign it for good and send a reply.
1332 			 * The ssap will be freed when the socket is closed.
1333 			 */
1334 			if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1335 				atomic_t *client_count;
1336 
1337 				sap = nfc_llcp_reserve_sdp_ssap(local);
1338 
1339 				pr_debug("Reserving %d\n", sap);
1340 
1341 				if (sap == LLCP_SAP_MAX) {
1342 					sap = 0;
1343 					nfc_llcp_sock_put(llcp_sock);
1344 					goto add_snl;
1345 				}
1346 
1347 				client_count =
1348 					&local->local_sdp_cnt[sap -
1349 							      LLCP_WKS_NUM_SAP];
1350 
1351 				atomic_inc(client_count);
1352 
1353 				llcp_sock->ssap = sap;
1354 				llcp_sock->reserved_ssap = sap;
1355 			} else {
1356 				sap = llcp_sock->ssap;
1357 			}
1358 
1359 			pr_debug("%p %d\n", llcp_sock, sap);
1360 
1361 			nfc_llcp_sock_put(llcp_sock);
1362 add_snl:
1363 			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
1364 			if (sdp == NULL)
1365 				goto exit;
1366 
1367 			sdres_tlvs_len += sdp->tlv_len;
1368 			hlist_add_head(&sdp->node, &llc_sdres_list);
1369 			break;
1370 
1371 		case LLCP_TLV_SDRES:
1372 			mutex_lock(&local->sdreq_lock);
1373 
1374 			pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]);
1375 
1376 			hlist_for_each_entry(sdp, &local->pending_sdreqs, node) {
1377 				if (sdp->tid != tlv[2])
1378 					continue;
1379 
1380 				sdp->sap = tlv[3];
1381 
1382 				pr_debug("Found: uri=%s, sap=%d\n",
1383 					 sdp->uri, sdp->sap);
1384 
1385 				hlist_del(&sdp->node);
1386 
1387 				hlist_add_head(&sdp->node, &nl_sdres_list);
1388 
1389 				break;
1390 			}
1391 
1392 			mutex_unlock(&local->sdreq_lock);
1393 			break;
1394 
1395 		default:
1396 			pr_err("Invalid SNL tlv value 0x%x\n", type);
1397 			break;
1398 		}
1399 
1400 		offset += length + 2;
1401 		tlv += length + 2;
1402 	}
1403 
1404 exit:
1405 	if (!hlist_empty(&nl_sdres_list))
1406 		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
1407 
1408 	if (!hlist_empty(&llc_sdres_list))
1409 		nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);
1410 }
1411 
1412 static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
1413 {
1414 	u8 ptype;
1415 	u16 pdu_len;
1416 	struct sk_buff *new_skb;
1417 
1418 	if (skb->len <= LLCP_HEADER_SIZE) {
1419 		pr_err("Malformed AGF PDU\n");
1420 		return;
1421 	}
1422 
1423 	skb_pull(skb, LLCP_HEADER_SIZE);
1424 
1425 	while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) {
1426 		pdu_len = skb->data[0] << 8 | skb->data[1];
1427 
1428 		skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE);
1429 
1430 		if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) {
1431 			pr_err("Malformed AGF PDU\n");
1432 			return;
1433 		}
1434 
1435 		ptype = nfc_llcp_ptype(skb);
1436 
1437 		if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF)
1438 			goto next;
1439 
1440 		new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
1441 		if (new_skb == NULL) {
1442 			pr_err("Could not allocate PDU\n");
1443 			return;
1444 		}
1445 
1446 		skb_put_data(new_skb, skb->data, pdu_len);
1447 
1448 		nfc_llcp_rx_skb(local, new_skb);
1449 
1450 		kfree_skb(new_skb);
1451 next:
1452 		skb_pull(skb, pdu_len);
1453 	}
1454 }
1455 
1456 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
1457 {
1458 	u8 dsap, ssap, ptype;
1459 
1460 	ptype = nfc_llcp_ptype(skb);
1461 	dsap = nfc_llcp_dsap(skb);
1462 	ssap = nfc_llcp_ssap(skb);
1463 
1464 	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1465 
1466 	if (ptype != LLCP_PDU_SYMM)
1467 		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
1468 				     skb->data, skb->len, true);
1469 
1470 	switch (ptype) {
1471 	case LLCP_PDU_SYMM:
1472 		pr_debug("SYMM\n");
1473 		break;
1474 
1475 	case LLCP_PDU_UI:
1476 		pr_debug("UI\n");
1477 		nfc_llcp_recv_ui(local, skb);
1478 		break;
1479 
1480 	case LLCP_PDU_CONNECT:
1481 		pr_debug("CONNECT\n");
1482 		nfc_llcp_recv_connect(local, skb);
1483 		break;
1484 
1485 	case LLCP_PDU_DISC:
1486 		pr_debug("DISC\n");
1487 		nfc_llcp_recv_disc(local, skb);
1488 		break;
1489 
1490 	case LLCP_PDU_CC:
1491 		pr_debug("CC\n");
1492 		nfc_llcp_recv_cc(local, skb);
1493 		break;
1494 
1495 	case LLCP_PDU_DM:
1496 		pr_debug("DM\n");
1497 		nfc_llcp_recv_dm(local, skb);
1498 		break;
1499 
1500 	case LLCP_PDU_SNL:
1501 		pr_debug("SNL\n");
1502 		nfc_llcp_recv_snl(local, skb);
1503 		break;
1504 
1505 	case LLCP_PDU_I:
1506 	case LLCP_PDU_RR:
1507 	case LLCP_PDU_RNR:
1508 		pr_debug("I frame\n");
1509 		nfc_llcp_recv_hdlc(local, skb);
1510 		break;
1511 
1512 	case LLCP_PDU_AGF:
1513 		pr_debug("AGF frame\n");
1514 		nfc_llcp_recv_agf(local, skb);
1515 		break;
1516 	}
1517 }
1518 
1519 static void nfc_llcp_rx_work(struct work_struct *work)
1520 {
1521 	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1522 						    rx_work);
1523 	struct sk_buff *skb;
1524 
1525 	skb = local->rx_pending;
1526 	if (skb == NULL) {
1527 		pr_debug("No pending SKB\n");
1528 		return;
1529 	}
1530 
1531 	__net_timestamp(skb);
1532 
1533 	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);
1534 
1535 	nfc_llcp_rx_skb(local, skb);
1536 
1537 	schedule_work(&local->tx_work);
1538 	kfree_skb(local->rx_pending);
1539 	local->rx_pending = NULL;
1540 }
1541 
1542 static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
1543 {
1544 	local->rx_pending = skb;
1545 	timer_delete(&local->link_timer);
1546 	schedule_work(&local->rx_work);
1547 }
1548 
1549 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1550 {
1551 	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1552 
1553 	if (err < 0) {
1554 		pr_err("LLCP PDU receive err %d\n", err);
1555 		return;
1556 	}
1557 
1558 	__nfc_llcp_recv(local, skb);
1559 }
1560 
1561 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1562 {
1563 	struct nfc_llcp_local *local;
1564 
1565 	local = nfc_llcp_find_local(dev);
1566 	if (local == NULL) {
1567 		kfree_skb(skb);
1568 		return -ENODEV;
1569 	}
1570 
1571 	__nfc_llcp_recv(local, skb);
1572 
1573 	nfc_llcp_local_put(local);
1574 
1575 	return 0;
1576 }
1577 
1578 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1579 {
1580 	struct nfc_llcp_local *local;
1581 
1582 	local = nfc_llcp_find_local(dev);
1583 	if (local == NULL)
1584 		return;
1585 
1586 	local->remote_miu = LLCP_DEFAULT_MIU;
1587 	local->remote_lto = LLCP_DEFAULT_LTO;
1588 
1589 	/* Close and purge all existing sockets */
1590 	nfc_llcp_socket_release(local, true, 0);
1591 
1592 	nfc_llcp_local_put(local);
1593 }
1594 
1595 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1596 			u8 comm_mode, u8 rf_mode)
1597 {
1598 	struct nfc_llcp_local *local;
1599 
1600 	pr_debug("rf mode %d\n", rf_mode);
1601 
1602 	local = nfc_llcp_find_local(dev);
1603 	if (local == NULL)
1604 		return;
1605 
1606 	local->target_idx = target_idx;
1607 	local->comm_mode = comm_mode;
1608 	local->rf_mode = rf_mode;
1609 
1610 	if (rf_mode == NFC_RF_INITIATOR) {
1611 		pr_debug("Queueing Tx work\n");
1612 
1613 		schedule_work(&local->tx_work);
1614 	} else {
1615 		mod_timer(&local->link_timer,
1616 			  jiffies + msecs_to_jiffies(local->remote_lto));
1617 	}
1618 
1619 	nfc_llcp_local_put(local);
1620 }
1621 
1622 int nfc_llcp_register_device(struct nfc_dev *ndev)
1623 {
1624 	struct nfc_llcp_local *local;
1625 
1626 	local = kzalloc_obj(struct nfc_llcp_local);
1627 	if (local == NULL)
1628 		return -ENOMEM;
1629 
1630 	/* As we are going to initialize local's refcount, we need to get the
1631 	 * nfc_dev to avoid UAF, otherwise there is no point in continuing.
1632 	 * See nfc_llcp_local_get().
1633 	 */
1634 	local->dev = nfc_get_device(ndev->idx);
1635 	if (!local->dev) {
1636 		kfree(local);
1637 		return -ENODEV;
1638 	}
1639 
1640 	INIT_LIST_HEAD(&local->list);
1641 	kref_init(&local->ref);
1642 	mutex_init(&local->sdp_lock);
1643 	timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0);
1644 
1645 	skb_queue_head_init(&local->tx_queue);
1646 	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1647 
1648 	local->rx_pending = NULL;
1649 	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1650 
1651 	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1652 
1653 	rwlock_init(&local->sockets.lock);
1654 	rwlock_init(&local->connecting_sockets.lock);
1655 	rwlock_init(&local->raw_sockets.lock);
1656 
1657 	local->lto = 150; /* 1500 ms */
1658 	local->rw = LLCP_MAX_RW;
1659 	local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1660 	local->local_wks = 0x1; /* LLC Link Management */
1661 
1662 	nfc_llcp_build_gb(local);
1663 
1664 	local->remote_miu = LLCP_DEFAULT_MIU;
1665 	local->remote_lto = LLCP_DEFAULT_LTO;
1666 
1667 	mutex_init(&local->sdreq_lock);
1668 	INIT_HLIST_HEAD(&local->pending_sdreqs);
1669 	timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0);
1670 	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
1671 
1672 	spin_lock(&llcp_devices_lock);
1673 	list_add(&local->list, &llcp_devices);
1674 	spin_unlock(&llcp_devices_lock);
1675 
1676 	return 0;
1677 }
1678 
1679 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1680 {
1681 	struct nfc_llcp_local *local = nfc_llcp_remove_local(dev);
1682 
1683 	if (local == NULL) {
1684 		pr_debug("No such device\n");
1685 		return;
1686 	}
1687 
1688 	local_cleanup(local);
1689 
1690 	nfc_llcp_local_put(local);
1691 }
1692 
1693 int __init nfc_llcp_init(void)
1694 {
1695 	return nfc_llcp_sock_init();
1696 }
1697 
1698 void nfc_llcp_exit(void)
1699 {
1700 	nfc_llcp_sock_exit();
1701 }
1702