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  1/*
  2 * Copyright (C) 2011  Intel Corporation. All rights reserved.
  3 *
  4 * This program is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License as published by
  6 * the Free Software Foundation; either version 2 of the License, or
  7 * (at your option) any later version.
  8 *
  9 * This program is distributed in the hope that it will be useful,
 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 12 * GNU General Public License for more details.
 13 *
 14 * You should have received a copy of the GNU General Public License
 15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 16 */
 17
 18#define pr_fmt(fmt) "llcp: %s: " fmt, __func__
 19
 20#include <linux/init.h>
 21#include <linux/kernel.h>
 22#include <linux/module.h>
 23#include <linux/nfc.h>
 24
 25#include <net/nfc/nfc.h>
 26
 27#include "nfc.h"
 28#include "llcp.h"
 29
 30static u8 llcp_tlv_length[LLCP_TLV_MAX] = {
 31	0,
 32	1, /* VERSION */
 33	2, /* MIUX */
 34	2, /* WKS */
 35	1, /* LTO */
 36	1, /* RW */
 37	0, /* SN */
 38	1, /* OPT */
 39	0, /* SDREQ */
 40	2, /* SDRES */
 41
 42};
 43
 44static u8 llcp_tlv8(u8 *tlv, u8 type)
 45{
 46	if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
 47		return 0;
 48
 49	return tlv[2];
 50}
 51
 52static u16 llcp_tlv16(u8 *tlv, u8 type)
 53{
 54	if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
 55		return 0;
 56
 57	return be16_to_cpu(*((__be16 *)(tlv + 2)));
 58}
 59
 60
 61static u8 llcp_tlv_version(u8 *tlv)
 62{
 63	return llcp_tlv8(tlv, LLCP_TLV_VERSION);
 64}
 65
 66static u16 llcp_tlv_miux(u8 *tlv)
 67{
 68	return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
 69}
 70
 71static u16 llcp_tlv_wks(u8 *tlv)
 72{
 73	return llcp_tlv16(tlv, LLCP_TLV_WKS);
 74}
 75
 76static u16 llcp_tlv_lto(u8 *tlv)
 77{
 78	return llcp_tlv8(tlv, LLCP_TLV_LTO);
 79}
 80
 81static u8 llcp_tlv_opt(u8 *tlv)
 82{
 83	return llcp_tlv8(tlv, LLCP_TLV_OPT);
 84}
 85
 86static u8 llcp_tlv_rw(u8 *tlv)
 87{
 88	return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
 89}
 90
 91u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length)
 92{
 93	u8 *tlv, length;
 94
 95	pr_debug("type %d\n", type);
 96
 97	if (type >= LLCP_TLV_MAX)
 98		return NULL;
 99
100	length = llcp_tlv_length[type];
101	if (length == 0 && value_length == 0)
102		return NULL;
103	else if (length == 0)
104		length = value_length;
105
106	*tlv_length = 2 + length;
107	tlv = kzalloc(2 + length, GFP_KERNEL);
108	if (tlv == NULL)
109		return tlv;
110
111	tlv[0] = type;
112	tlv[1] = length;
113	memcpy(tlv + 2, value, length);
114
115	return tlv;
116}
117
118struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap)
119{
120	struct nfc_llcp_sdp_tlv *sdres;
121	u8 value[2];
122
123	sdres = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
124	if (sdres == NULL)
125		return NULL;
126
127	value[0] = tid;
128	value[1] = sap;
129
130	sdres->tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2,
131					&sdres->tlv_len);
132	if (sdres->tlv == NULL) {
133		kfree(sdres);
134		return NULL;
135	}
136
137	sdres->tid = tid;
138	sdres->sap = sap;
139
140	INIT_HLIST_NODE(&sdres->node);
141
142	return sdres;
143}
144
145struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, char *uri,
146						  size_t uri_len)
147{
148	struct nfc_llcp_sdp_tlv *sdreq;
149
150	pr_debug("uri: %s, len: %zu\n", uri, uri_len);
151
152	/* sdreq->tlv_len is u8, takes uri_len, + 3 for header, + 1 for NULL */
153	if (WARN_ON_ONCE(uri_len > U8_MAX - 4))
154		return NULL;
155
156	sdreq = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
157	if (sdreq == NULL)
158		return NULL;
159
160	sdreq->tlv_len = uri_len + 3;
161
162	if (uri[uri_len - 1] == 0)
163		sdreq->tlv_len--;
164
165	sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL);
166	if (sdreq->tlv == NULL) {
167		kfree(sdreq);
168		return NULL;
169	}
170
171	sdreq->tlv[0] = LLCP_TLV_SDREQ;
172	sdreq->tlv[1] = sdreq->tlv_len - 2;
173	sdreq->tlv[2] = tid;
174
175	sdreq->tid = tid;
176	sdreq->uri = sdreq->tlv + 3;
177	memcpy(sdreq->uri, uri, uri_len);
178
179	sdreq->time = jiffies;
180
181	INIT_HLIST_NODE(&sdreq->node);
182
183	return sdreq;
184}
185
186void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
187{
188	kfree(sdp->tlv);
189	kfree(sdp);
190}
191
192void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head)
193{
194	struct nfc_llcp_sdp_tlv *sdp;
195	struct hlist_node *n;
196
197	hlist_for_each_entry_safe(sdp, n, head, node) {
198		hlist_del(&sdp->node);
199
200		nfc_llcp_free_sdp_tlv(sdp);
201	}
202}
203
204int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
205			  u8 *tlv_array, u16 tlv_array_len)
206{
207	u8 *tlv = tlv_array, type, length, offset = 0;
208
209	pr_debug("TLV array length %d\n", tlv_array_len);
210
211	if (local == NULL)
212		return -ENODEV;
213
214	while (offset < tlv_array_len) {
215		type = tlv[0];
216		length = tlv[1];
217
218		pr_debug("type 0x%x length %d\n", type, length);
219
220		switch (type) {
221		case LLCP_TLV_VERSION:
222			local->remote_version = llcp_tlv_version(tlv);
223			break;
224		case LLCP_TLV_MIUX:
225			local->remote_miu = llcp_tlv_miux(tlv) + 128;
226			break;
227		case LLCP_TLV_WKS:
228			local->remote_wks = llcp_tlv_wks(tlv);
229			break;
230		case LLCP_TLV_LTO:
231			local->remote_lto = llcp_tlv_lto(tlv) * 10;
232			break;
233		case LLCP_TLV_OPT:
234			local->remote_opt = llcp_tlv_opt(tlv);
235			break;
236		default:
237			pr_err("Invalid gt tlv value 0x%x\n", type);
238			break;
239		}
240
241		offset += length + 2;
242		tlv += length + 2;
243	}
244
245	pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n",
246		 local->remote_version, local->remote_miu,
247		 local->remote_lto, local->remote_opt,
248		 local->remote_wks);
249
250	return 0;
251}
252
253int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
254				  u8 *tlv_array, u16 tlv_array_len)
255{
256	u8 *tlv = tlv_array, type, length, offset = 0;
257
258	pr_debug("TLV array length %d\n", tlv_array_len);
259
260	if (sock == NULL)
261		return -ENOTCONN;
262
263	while (offset < tlv_array_len) {
264		type = tlv[0];
265		length = tlv[1];
266
267		pr_debug("type 0x%x length %d\n", type, length);
268
269		switch (type) {
270		case LLCP_TLV_MIUX:
271			sock->remote_miu = llcp_tlv_miux(tlv) + 128;
272			break;
273		case LLCP_TLV_RW:
274			sock->remote_rw = llcp_tlv_rw(tlv);
275			break;
276		case LLCP_TLV_SN:
277			break;
278		default:
279			pr_err("Invalid gt tlv value 0x%x\n", type);
280			break;
281		}
282
283		offset += length + 2;
284		tlv += length + 2;
285	}
286
287	pr_debug("sock %p rw %d miu %d\n", sock,
288		 sock->remote_rw, sock->remote_miu);
289
290	return 0;
291}
292
293static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
294				       u8 dsap, u8 ssap, u8 ptype)
295{
296	u8 header[2];
297
298	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
299
300	header[0] = (u8)((dsap << 2) | (ptype >> 2));
301	header[1] = (u8)((ptype << 6) | ssap);
302
303	pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
304
305	skb_put_data(pdu, header, LLCP_HEADER_SIZE);
306
307	return pdu;
308}
309
310static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv,
311				    u8 tlv_length)
312{
313	/* XXX Add an skb length check */
314
315	if (tlv == NULL)
316		return NULL;
317
318	skb_put_data(pdu, tlv, tlv_length);
319
320	return pdu;
321}
322
323static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock,
324					 u8 cmd, u16 size)
325{
326	struct sk_buff *skb;
327	int err;
328
329	if (sock->ssap == 0)
330		return NULL;
331
332	skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
333				 size + LLCP_HEADER_SIZE, &err);
334	if (skb == NULL) {
335		pr_err("Could not allocate PDU\n");
336		return NULL;
337	}
338
339	skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
340
341	return skb;
342}
343
344int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
345{
346	struct sk_buff *skb;
347	struct nfc_dev *dev;
348	struct nfc_llcp_local *local;
349
350	pr_debug("Sending DISC\n");
351
352	local = sock->local;
353	if (local == NULL)
354		return -ENODEV;
355
356	dev = sock->dev;
357	if (dev == NULL)
358		return -ENODEV;
359
360	skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
361	if (skb == NULL)
362		return -ENOMEM;
363
364	skb_queue_tail(&local->tx_queue, skb);
365
366	return 0;
367}
368
369int nfc_llcp_send_symm(struct nfc_dev *dev)
370{
371	struct sk_buff *skb;
372	struct nfc_llcp_local *local;
373	u16 size = 0;
374
375	pr_debug("Sending SYMM\n");
376
377	local = nfc_llcp_find_local(dev);
378	if (local == NULL)
379		return -ENODEV;
380
381	size += LLCP_HEADER_SIZE;
382	size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
383
384	skb = alloc_skb(size, GFP_KERNEL);
385	if (skb == NULL)
386		return -ENOMEM;
387
388	skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
389
390	skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
391
392	__net_timestamp(skb);
393
394	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX);
395
396	return nfc_data_exchange(dev, local->target_idx, skb,
397				 nfc_llcp_recv, local);
398}
399
400int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
401{
402	struct nfc_llcp_local *local;
403	struct sk_buff *skb;
404	u8 *service_name_tlv = NULL, service_name_tlv_length;
405	u8 *miux_tlv = NULL, miux_tlv_length;
406	u8 *rw_tlv = NULL, rw_tlv_length, rw;
407	int err;
408	u16 size = 0;
409	__be16 miux;
410
411	pr_debug("Sending CONNECT\n");
412
413	local = sock->local;
414	if (local == NULL)
415		return -ENODEV;
416
417	if (sock->service_name != NULL) {
418		service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
419						      sock->service_name,
420						      sock->service_name_len,
421						      &service_name_tlv_length);
422		size += service_name_tlv_length;
423	}
424
425	/* If the socket parameters are not set, use the local ones */
426	miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
427		local->miux : sock->miux;
428	rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
429
430	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
431				      &miux_tlv_length);
432	size += miux_tlv_length;
433
434	rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
435	size += rw_tlv_length;
436
437	pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
438
439	skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
440	if (skb == NULL) {
441		err = -ENOMEM;
442		goto error_tlv;
443	}
444
445	llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length);
446	llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
447	llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
448
449	skb_queue_tail(&local->tx_queue, skb);
450
451	err = 0;
452
453error_tlv:
454	if (err)
455		pr_err("error %d\n", err);
456
457	kfree(service_name_tlv);
458	kfree(miux_tlv);
459	kfree(rw_tlv);
460
461	return err;
462}
463
464int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
465{
466	struct nfc_llcp_local *local;
467	struct sk_buff *skb;
468	u8 *miux_tlv = NULL, miux_tlv_length;
469	u8 *rw_tlv = NULL, rw_tlv_length, rw;
470	int err;
471	u16 size = 0;
472	__be16 miux;
473
474	pr_debug("Sending CC\n");
475
476	local = sock->local;
477	if (local == NULL)
478		return -ENODEV;
479
480	/* If the socket parameters are not set, use the local ones */
481	miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
482		local->miux : sock->miux;
483	rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
484
485	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
486				      &miux_tlv_length);
487	size += miux_tlv_length;
488
489	rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
490	size += rw_tlv_length;
491
492	skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
493	if (skb == NULL) {
494		err = -ENOMEM;
495		goto error_tlv;
496	}
497
498	llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
499	llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
500
501	skb_queue_tail(&local->tx_queue, skb);
502
503	err = 0;
504
505error_tlv:
506	if (err)
507		pr_err("error %d\n", err);
508
509	kfree(miux_tlv);
510	kfree(rw_tlv);
511
512	return err;
513}
514
515static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
516					     size_t tlv_length)
517{
518	struct sk_buff *skb;
519	struct nfc_dev *dev;
520	u16 size = 0;
521
522	if (local == NULL)
523		return ERR_PTR(-ENODEV);
524
525	dev = local->dev;
526	if (dev == NULL)
527		return ERR_PTR(-ENODEV);
528
529	size += LLCP_HEADER_SIZE;
530	size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
531	size += tlv_length;
532
533	skb = alloc_skb(size, GFP_KERNEL);
534	if (skb == NULL)
535		return ERR_PTR(-ENOMEM);
536
537	skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
538
539	skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
540
541	return skb;
542}
543
544int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
545			    struct hlist_head *tlv_list, size_t tlvs_len)
546{
547	struct nfc_llcp_sdp_tlv *sdp;
548	struct hlist_node *n;
549	struct sk_buff *skb;
550
551	skb = nfc_llcp_allocate_snl(local, tlvs_len);
552	if (IS_ERR(skb))
553		return PTR_ERR(skb);
554
555	hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
556		skb_put_data(skb, sdp->tlv, sdp->tlv_len);
557
558		hlist_del(&sdp->node);
559
560		nfc_llcp_free_sdp_tlv(sdp);
561	}
562
563	skb_queue_tail(&local->tx_queue, skb);
564
565	return 0;
566}
567
568int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
569			    struct hlist_head *tlv_list, size_t tlvs_len)
570{
571	struct nfc_llcp_sdp_tlv *sdreq;
572	struct hlist_node *n;
573	struct sk_buff *skb;
574
575	skb = nfc_llcp_allocate_snl(local, tlvs_len);
576	if (IS_ERR(skb))
577		return PTR_ERR(skb);
578
579	mutex_lock(&local->sdreq_lock);
580
581	if (hlist_empty(&local->pending_sdreqs))
582		mod_timer(&local->sdreq_timer,
583			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
584
585	hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
586		pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
587
588		skb_put_data(skb, sdreq->tlv, sdreq->tlv_len);
589
590		hlist_del(&sdreq->node);
591
592		hlist_add_head(&sdreq->node, &local->pending_sdreqs);
593	}
594
595	mutex_unlock(&local->sdreq_lock);
596
597	skb_queue_tail(&local->tx_queue, skb);
598
599	return 0;
600}
601
602int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
603{
604	struct sk_buff *skb;
605	struct nfc_dev *dev;
606	u16 size = 1; /* Reason code */
607
608	pr_debug("Sending DM reason 0x%x\n", reason);
609
610	if (local == NULL)
611		return -ENODEV;
612
613	dev = local->dev;
614	if (dev == NULL)
615		return -ENODEV;
616
617	size += LLCP_HEADER_SIZE;
618	size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
619
620	skb = alloc_skb(size, GFP_KERNEL);
621	if (skb == NULL)
622		return -ENOMEM;
623
624	skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
625
626	skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
627
628	skb_put_data(skb, &reason, 1);
629
630	skb_queue_head(&local->tx_queue, skb);
631
632	return 0;
633}
634
635int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
636			  struct msghdr *msg, size_t len)
637{
638	struct sk_buff *pdu;
639	struct sock *sk = &sock->sk;
640	struct nfc_llcp_local *local;
641	size_t frag_len = 0, remaining_len;
642	u8 *msg_data, *msg_ptr;
643	u16 remote_miu;
644
645	pr_debug("Send I frame len %zd\n", len);
646
647	local = sock->local;
648	if (local == NULL)
649		return -ENODEV;
650
651	/* Remote is ready but has not acknowledged our frames */
652	if((sock->remote_ready &&
653	    skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw &&
654	    skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
655		pr_err("Pending queue is full %d frames\n",
656		       skb_queue_len(&sock->tx_pending_queue));
657		return -ENOBUFS;
658	}
659
660	/* Remote is not ready and we've been queueing enough frames */
661	if ((!sock->remote_ready &&
662	     skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
663		pr_err("Tx queue is full %d frames\n",
664		       skb_queue_len(&sock->tx_queue));
665		return -ENOBUFS;
666	}
667
668	msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
669	if (msg_data == NULL)
670		return -ENOMEM;
671
672	if (memcpy_from_msg(msg_data, msg, len)) {
673		kfree(msg_data);
674		return -EFAULT;
675	}
676
677	remaining_len = len;
678	msg_ptr = msg_data;
679
680	do {
681		remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
682				LLCP_DEFAULT_MIU : sock->remote_miu;
683
684		frag_len = min_t(size_t, remote_miu, remaining_len);
685
686		pr_debug("Fragment %zd bytes remaining %zd",
687			 frag_len, remaining_len);
688
689		pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
690					frag_len + LLCP_SEQUENCE_SIZE);
691		if (pdu == NULL) {
692			kfree(msg_data);
693			return -ENOMEM;
694		}
695
696		skb_put(pdu, LLCP_SEQUENCE_SIZE);
697
698		if (likely(frag_len > 0))
699			skb_put_data(pdu, msg_ptr, frag_len);
700
701		skb_queue_tail(&sock->tx_queue, pdu);
702
703		lock_sock(sk);
704
705		nfc_llcp_queue_i_frames(sock);
706
707		release_sock(sk);
708
709		remaining_len -= frag_len;
710		msg_ptr += frag_len;
711	} while (remaining_len > 0);
712
713	kfree(msg_data);
714
715	return len;
716}
717
718int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
719			   struct msghdr *msg, size_t len)
720{
721	struct sk_buff *pdu;
722	struct nfc_llcp_local *local;
723	size_t frag_len = 0, remaining_len;
724	u8 *msg_ptr, *msg_data;
725	u16 remote_miu;
726	int err;
727
728	pr_debug("Send UI frame len %zd\n", len);
729
730	local = sock->local;
731	if (local == NULL)
732		return -ENODEV;
733
734	msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
735	if (msg_data == NULL)
736		return -ENOMEM;
737
738	if (memcpy_from_msg(msg_data, msg, len)) {
739		kfree(msg_data);
740		return -EFAULT;
741	}
742
743	remaining_len = len;
744	msg_ptr = msg_data;
745
746	do {
747		remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
748				local->remote_miu : sock->remote_miu;
749
750		frag_len = min_t(size_t, remote_miu, remaining_len);
751
752		pr_debug("Fragment %zd bytes remaining %zd",
753			 frag_len, remaining_len);
754
755		pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
756					 frag_len + LLCP_HEADER_SIZE, &err);
757		if (pdu == NULL) {
758			pr_err("Could not allocate PDU\n");
759			continue;
760		}
761
762		pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
763
764		if (likely(frag_len > 0))
765			skb_put_data(pdu, msg_ptr, frag_len);
766
767		/* No need to check for the peer RW for UI frames */
768		skb_queue_tail(&local->tx_queue, pdu);
769
770		remaining_len -= frag_len;
771		msg_ptr += frag_len;
772	} while (remaining_len > 0);
773
774	kfree(msg_data);
775
776	return len;
777}
778
779int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
780{
781	struct sk_buff *skb;
782	struct nfc_llcp_local *local;
783
784	pr_debug("Send rr nr %d\n", sock->recv_n);
785
786	local = sock->local;
787	if (local == NULL)
788		return -ENODEV;
789
790	skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
791	if (skb == NULL)
792		return -ENOMEM;
793
794	skb_put(skb, LLCP_SEQUENCE_SIZE);
795
796	skb->data[2] = sock->recv_n;
797
798	skb_queue_head(&local->tx_queue, skb);
799
800	return 0;
801}