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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2011 Intel Corporation. All rights reserved.
4 */
5
6#define pr_fmt(fmt) "llcp: %s: " fmt, __func__
7
8#include <linux/init.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/nfc.h>
12
13#include <net/nfc/nfc.h>
14
15#include "nfc.h"
16#include "llcp.h"
17
18static const u8 llcp_tlv_length[LLCP_TLV_MAX] = {
19 0,
20 1, /* VERSION */
21 2, /* MIUX */
22 2, /* WKS */
23 1, /* LTO */
24 1, /* RW */
25 0, /* SN */
26 1, /* OPT */
27 0, /* SDREQ */
28 2, /* SDRES */
29
30};
31
32static u8 llcp_tlv8(const u8 *tlv, u8 type)
33{
34 if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
35 return 0;
36
37 return tlv[2];
38}
39
40static u16 llcp_tlv16(const u8 *tlv, u8 type)
41{
42 if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
43 return 0;
44
45 return be16_to_cpu(*((__be16 *)(tlv + 2)));
46}
47
48
49static u8 llcp_tlv_version(const u8 *tlv)
50{
51 return llcp_tlv8(tlv, LLCP_TLV_VERSION);
52}
53
54static u16 llcp_tlv_miux(const u8 *tlv)
55{
56 return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
57}
58
59static u16 llcp_tlv_wks(const u8 *tlv)
60{
61 return llcp_tlv16(tlv, LLCP_TLV_WKS);
62}
63
64static u16 llcp_tlv_lto(const u8 *tlv)
65{
66 return llcp_tlv8(tlv, LLCP_TLV_LTO);
67}
68
69static u8 llcp_tlv_opt(const u8 *tlv)
70{
71 return llcp_tlv8(tlv, LLCP_TLV_OPT);
72}
73
74static u8 llcp_tlv_rw(const u8 *tlv)
75{
76 return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
77}
78
79u8 *nfc_llcp_build_tlv(u8 type, const u8 *value, u8 value_length, u8 *tlv_length)
80{
81 u8 *tlv, length;
82
83 pr_debug("type %d\n", type);
84
85 if (type >= LLCP_TLV_MAX)
86 return NULL;
87
88 length = llcp_tlv_length[type];
89 if (length == 0 && value_length == 0)
90 return NULL;
91 else if (length == 0)
92 length = value_length;
93
94 *tlv_length = 2 + length;
95 tlv = kzalloc(2 + length, GFP_KERNEL);
96 if (tlv == NULL)
97 return tlv;
98
99 tlv[0] = type;
100 tlv[1] = length;
101 memcpy(tlv + 2, value, length);
102
103 return tlv;
104}
105
106struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap)
107{
108 struct nfc_llcp_sdp_tlv *sdres;
109 u8 value[2];
110
111 sdres = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
112 if (sdres == NULL)
113 return NULL;
114
115 value[0] = tid;
116 value[1] = sap;
117
118 sdres->tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2,
119 &sdres->tlv_len);
120 if (sdres->tlv == NULL) {
121 kfree(sdres);
122 return NULL;
123 }
124
125 sdres->tid = tid;
126 sdres->sap = sap;
127
128 INIT_HLIST_NODE(&sdres->node);
129
130 return sdres;
131}
132
133struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, const char *uri,
134 size_t uri_len)
135{
136 struct nfc_llcp_sdp_tlv *sdreq;
137
138 pr_debug("uri: %s, len: %zu\n", uri, uri_len);
139
140 /* sdreq->tlv_len is u8, takes uri_len, + 3 for header, + 1 for NULL */
141 if (WARN_ON_ONCE(uri_len > U8_MAX - 4))
142 return NULL;
143
144 sdreq = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
145 if (sdreq == NULL)
146 return NULL;
147
148 sdreq->tlv_len = uri_len + 3;
149
150 if (uri[uri_len - 1] == 0)
151 sdreq->tlv_len--;
152
153 sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL);
154 if (sdreq->tlv == NULL) {
155 kfree(sdreq);
156 return NULL;
157 }
158
159 sdreq->tlv[0] = LLCP_TLV_SDREQ;
160 sdreq->tlv[1] = sdreq->tlv_len - 2;
161 sdreq->tlv[2] = tid;
162
163 sdreq->tid = tid;
164 sdreq->uri = sdreq->tlv + 3;
165 memcpy(sdreq->uri, uri, uri_len);
166
167 sdreq->time = jiffies;
168
169 INIT_HLIST_NODE(&sdreq->node);
170
171 return sdreq;
172}
173
174void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
175{
176 kfree(sdp->tlv);
177 kfree(sdp);
178}
179
180void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head)
181{
182 struct nfc_llcp_sdp_tlv *sdp;
183 struct hlist_node *n;
184
185 hlist_for_each_entry_safe(sdp, n, head, node) {
186 hlist_del(&sdp->node);
187
188 nfc_llcp_free_sdp_tlv(sdp);
189 }
190}
191
192int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
193 const u8 *tlv_array, u16 tlv_array_len)
194{
195 const u8 *tlv = tlv_array;
196 u8 type, length, offset = 0;
197
198 pr_debug("TLV array length %d\n", tlv_array_len);
199
200 if (local == NULL)
201 return -ENODEV;
202
203 while (offset < tlv_array_len) {
204 type = tlv[0];
205 length = tlv[1];
206
207 pr_debug("type 0x%x length %d\n", type, length);
208
209 switch (type) {
210 case LLCP_TLV_VERSION:
211 local->remote_version = llcp_tlv_version(tlv);
212 break;
213 case LLCP_TLV_MIUX:
214 local->remote_miu = llcp_tlv_miux(tlv) + 128;
215 break;
216 case LLCP_TLV_WKS:
217 local->remote_wks = llcp_tlv_wks(tlv);
218 break;
219 case LLCP_TLV_LTO:
220 local->remote_lto = llcp_tlv_lto(tlv) * 10;
221 break;
222 case LLCP_TLV_OPT:
223 local->remote_opt = llcp_tlv_opt(tlv);
224 break;
225 default:
226 pr_err("Invalid gt tlv value 0x%x\n", type);
227 break;
228 }
229
230 offset += length + 2;
231 tlv += length + 2;
232 }
233
234 pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n",
235 local->remote_version, local->remote_miu,
236 local->remote_lto, local->remote_opt,
237 local->remote_wks);
238
239 return 0;
240}
241
242int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
243 const u8 *tlv_array, u16 tlv_array_len)
244{
245 const u8 *tlv = tlv_array;
246 u8 type, length, offset = 0;
247
248 pr_debug("TLV array length %d\n", tlv_array_len);
249
250 if (sock == NULL)
251 return -ENOTCONN;
252
253 while (offset < tlv_array_len) {
254 type = tlv[0];
255 length = tlv[1];
256
257 pr_debug("type 0x%x length %d\n", type, length);
258
259 switch (type) {
260 case LLCP_TLV_MIUX:
261 sock->remote_miu = llcp_tlv_miux(tlv) + 128;
262 break;
263 case LLCP_TLV_RW:
264 sock->remote_rw = llcp_tlv_rw(tlv);
265 break;
266 case LLCP_TLV_SN:
267 break;
268 default:
269 pr_err("Invalid gt tlv value 0x%x\n", type);
270 break;
271 }
272
273 offset += length + 2;
274 tlv += length + 2;
275 }
276
277 pr_debug("sock %p rw %d miu %d\n", sock,
278 sock->remote_rw, sock->remote_miu);
279
280 return 0;
281}
282
283static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
284 u8 dsap, u8 ssap, u8 ptype)
285{
286 u8 header[2];
287
288 pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
289
290 header[0] = (u8)((dsap << 2) | (ptype >> 2));
291 header[1] = (u8)((ptype << 6) | ssap);
292
293 pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
294
295 skb_put_data(pdu, header, LLCP_HEADER_SIZE);
296
297 return pdu;
298}
299
300static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, const u8 *tlv,
301 u8 tlv_length)
302{
303 /* XXX Add an skb length check */
304
305 if (tlv == NULL)
306 return NULL;
307
308 skb_put_data(pdu, tlv, tlv_length);
309
310 return pdu;
311}
312
313static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock,
314 u8 cmd, u16 size)
315{
316 struct sk_buff *skb;
317 int err;
318
319 if (sock->ssap == 0)
320 return NULL;
321
322 skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
323 size + LLCP_HEADER_SIZE, &err);
324 if (skb == NULL) {
325 pr_err("Could not allocate PDU\n");
326 return NULL;
327 }
328
329 skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
330
331 return skb;
332}
333
334int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
335{
336 struct sk_buff *skb;
337 struct nfc_dev *dev;
338 struct nfc_llcp_local *local;
339
340 local = sock->local;
341 if (local == NULL)
342 return -ENODEV;
343
344 dev = sock->dev;
345 if (dev == NULL)
346 return -ENODEV;
347
348 skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
349 if (skb == NULL)
350 return -ENOMEM;
351
352 skb_queue_tail(&local->tx_queue, skb);
353
354 return 0;
355}
356
357int nfc_llcp_send_symm(struct nfc_dev *dev)
358{
359 struct sk_buff *skb;
360 struct nfc_llcp_local *local;
361 u16 size = 0;
362
363 local = nfc_llcp_find_local(dev);
364 if (local == NULL)
365 return -ENODEV;
366
367 size += LLCP_HEADER_SIZE;
368 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
369
370 skb = alloc_skb(size, GFP_KERNEL);
371 if (skb == NULL)
372 return -ENOMEM;
373
374 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
375
376 skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
377
378 __net_timestamp(skb);
379
380 nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX);
381
382 return nfc_data_exchange(dev, local->target_idx, skb,
383 nfc_llcp_recv, local);
384}
385
386int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
387{
388 struct nfc_llcp_local *local;
389 struct sk_buff *skb;
390 const u8 *service_name_tlv = NULL;
391 const u8 *miux_tlv = NULL;
392 const u8 *rw_tlv = NULL;
393 u8 service_name_tlv_length, miux_tlv_length, rw_tlv_length, rw;
394 int err;
395 u16 size = 0;
396 __be16 miux;
397
398 local = sock->local;
399 if (local == NULL)
400 return -ENODEV;
401
402 if (sock->service_name != NULL) {
403 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
404 sock->service_name,
405 sock->service_name_len,
406 &service_name_tlv_length);
407 if (!service_name_tlv) {
408 err = -ENOMEM;
409 goto error_tlv;
410 }
411 size += service_name_tlv_length;
412 }
413
414 /* If the socket parameters are not set, use the local ones */
415 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
416 local->miux : sock->miux;
417 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
418
419 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
420 &miux_tlv_length);
421 if (!miux_tlv) {
422 err = -ENOMEM;
423 goto error_tlv;
424 }
425 size += miux_tlv_length;
426
427 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
428 if (!rw_tlv) {
429 err = -ENOMEM;
430 goto error_tlv;
431 }
432 size += rw_tlv_length;
433
434 pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
435
436 skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
437 if (skb == NULL) {
438 err = -ENOMEM;
439 goto error_tlv;
440 }
441
442 llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length);
443 llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
444 llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
445
446 skb_queue_tail(&local->tx_queue, skb);
447
448 err = 0;
449
450error_tlv:
451 if (err)
452 pr_err("error %d\n", err);
453
454 kfree(service_name_tlv);
455 kfree(miux_tlv);
456 kfree(rw_tlv);
457
458 return err;
459}
460
461int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
462{
463 struct nfc_llcp_local *local;
464 struct sk_buff *skb;
465 const u8 *miux_tlv = NULL;
466 const u8 *rw_tlv = NULL;
467 u8 miux_tlv_length, rw_tlv_length, rw;
468 int err;
469 u16 size = 0;
470 __be16 miux;
471
472 local = sock->local;
473 if (local == NULL)
474 return -ENODEV;
475
476 /* If the socket parameters are not set, use the local ones */
477 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
478 local->miux : sock->miux;
479 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
480
481 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
482 &miux_tlv_length);
483 if (!miux_tlv) {
484 err = -ENOMEM;
485 goto error_tlv;
486 }
487 size += miux_tlv_length;
488
489 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
490 if (!rw_tlv) {
491 err = -ENOMEM;
492 goto error_tlv;
493 }
494 size += rw_tlv_length;
495
496 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
497 if (skb == NULL) {
498 err = -ENOMEM;
499 goto error_tlv;
500 }
501
502 llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
503 llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
504
505 skb_queue_tail(&local->tx_queue, skb);
506
507 err = 0;
508
509error_tlv:
510 if (err)
511 pr_err("error %d\n", err);
512
513 kfree(miux_tlv);
514 kfree(rw_tlv);
515
516 return err;
517}
518
519static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
520 size_t tlv_length)
521{
522 struct sk_buff *skb;
523 struct nfc_dev *dev;
524 u16 size = 0;
525
526 if (local == NULL)
527 return ERR_PTR(-ENODEV);
528
529 dev = local->dev;
530 if (dev == NULL)
531 return ERR_PTR(-ENODEV);
532
533 size += LLCP_HEADER_SIZE;
534 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
535 size += tlv_length;
536
537 skb = alloc_skb(size, GFP_KERNEL);
538 if (skb == NULL)
539 return ERR_PTR(-ENOMEM);
540
541 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
542
543 skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
544
545 return skb;
546}
547
548int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
549 struct hlist_head *tlv_list, size_t tlvs_len)
550{
551 struct nfc_llcp_sdp_tlv *sdp;
552 struct hlist_node *n;
553 struct sk_buff *skb;
554
555 skb = nfc_llcp_allocate_snl(local, tlvs_len);
556 if (IS_ERR(skb))
557 return PTR_ERR(skb);
558
559 hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
560 skb_put_data(skb, sdp->tlv, sdp->tlv_len);
561
562 hlist_del(&sdp->node);
563
564 nfc_llcp_free_sdp_tlv(sdp);
565 }
566
567 skb_queue_tail(&local->tx_queue, skb);
568
569 return 0;
570}
571
572int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
573 struct hlist_head *tlv_list, size_t tlvs_len)
574{
575 struct nfc_llcp_sdp_tlv *sdreq;
576 struct hlist_node *n;
577 struct sk_buff *skb;
578
579 skb = nfc_llcp_allocate_snl(local, tlvs_len);
580 if (IS_ERR(skb))
581 return PTR_ERR(skb);
582
583 mutex_lock(&local->sdreq_lock);
584
585 if (hlist_empty(&local->pending_sdreqs))
586 mod_timer(&local->sdreq_timer,
587 jiffies + msecs_to_jiffies(3 * local->remote_lto));
588
589 hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
590 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
591
592 skb_put_data(skb, sdreq->tlv, sdreq->tlv_len);
593
594 hlist_del(&sdreq->node);
595
596 hlist_add_head(&sdreq->node, &local->pending_sdreqs);
597 }
598
599 mutex_unlock(&local->sdreq_lock);
600
601 skb_queue_tail(&local->tx_queue, skb);
602
603 return 0;
604}
605
606int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
607{
608 struct sk_buff *skb;
609 struct nfc_dev *dev;
610 u16 size = 1; /* Reason code */
611
612 pr_debug("Sending DM reason 0x%x\n", reason);
613
614 if (local == NULL)
615 return -ENODEV;
616
617 dev = local->dev;
618 if (dev == NULL)
619 return -ENODEV;
620
621 size += LLCP_HEADER_SIZE;
622 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
623
624 skb = alloc_skb(size, GFP_KERNEL);
625 if (skb == NULL)
626 return -ENOMEM;
627
628 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
629
630 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
631
632 skb_put_data(skb, &reason, 1);
633
634 skb_queue_head(&local->tx_queue, skb);
635
636 return 0;
637}
638
639int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
640 struct msghdr *msg, size_t len)
641{
642 struct sk_buff *pdu;
643 struct sock *sk = &sock->sk;
644 struct nfc_llcp_local *local;
645 size_t frag_len = 0, remaining_len;
646 u8 *msg_data, *msg_ptr;
647 u16 remote_miu;
648
649 pr_debug("Send I frame len %zd\n", len);
650
651 local = sock->local;
652 if (local == NULL)
653 return -ENODEV;
654
655 /* Remote is ready but has not acknowledged our frames */
656 if((sock->remote_ready &&
657 skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw &&
658 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
659 pr_err("Pending queue is full %d frames\n",
660 skb_queue_len(&sock->tx_pending_queue));
661 return -ENOBUFS;
662 }
663
664 /* Remote is not ready and we've been queueing enough frames */
665 if ((!sock->remote_ready &&
666 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
667 pr_err("Tx queue is full %d frames\n",
668 skb_queue_len(&sock->tx_queue));
669 return -ENOBUFS;
670 }
671
672 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
673 if (msg_data == NULL)
674 return -ENOMEM;
675
676 if (memcpy_from_msg(msg_data, msg, len)) {
677 kfree(msg_data);
678 return -EFAULT;
679 }
680
681 remaining_len = len;
682 msg_ptr = msg_data;
683
684 do {
685 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
686 LLCP_DEFAULT_MIU : sock->remote_miu;
687
688 frag_len = min_t(size_t, remote_miu, remaining_len);
689
690 pr_debug("Fragment %zd bytes remaining %zd",
691 frag_len, remaining_len);
692
693 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
694 frag_len + LLCP_SEQUENCE_SIZE);
695 if (pdu == NULL) {
696 kfree(msg_data);
697 return -ENOMEM;
698 }
699
700 skb_put(pdu, LLCP_SEQUENCE_SIZE);
701
702 if (likely(frag_len > 0))
703 skb_put_data(pdu, msg_ptr, frag_len);
704
705 skb_queue_tail(&sock->tx_queue, pdu);
706
707 lock_sock(sk);
708
709 nfc_llcp_queue_i_frames(sock);
710
711 release_sock(sk);
712
713 remaining_len -= frag_len;
714 msg_ptr += frag_len;
715 } while (remaining_len > 0);
716
717 kfree(msg_data);
718
719 return len;
720}
721
722int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
723 struct msghdr *msg, size_t len)
724{
725 struct sk_buff *pdu;
726 struct nfc_llcp_local *local;
727 size_t frag_len = 0, remaining_len;
728 u8 *msg_ptr, *msg_data;
729 u16 remote_miu;
730 int err;
731
732 pr_debug("Send UI frame len %zd\n", len);
733
734 local = sock->local;
735 if (local == NULL)
736 return -ENODEV;
737
738 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
739 if (msg_data == NULL)
740 return -ENOMEM;
741
742 if (memcpy_from_msg(msg_data, msg, len)) {
743 kfree(msg_data);
744 return -EFAULT;
745 }
746
747 remaining_len = len;
748 msg_ptr = msg_data;
749
750 do {
751 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
752 local->remote_miu : sock->remote_miu;
753
754 frag_len = min_t(size_t, remote_miu, remaining_len);
755
756 pr_debug("Fragment %zd bytes remaining %zd",
757 frag_len, remaining_len);
758
759 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0,
760 frag_len + LLCP_HEADER_SIZE, &err);
761 if (pdu == NULL) {
762 pr_err("Could not allocate PDU (error=%d)\n", err);
763 len -= remaining_len;
764 if (len == 0)
765 len = err;
766 break;
767 }
768
769 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
770
771 if (likely(frag_len > 0))
772 skb_put_data(pdu, msg_ptr, frag_len);
773
774 /* No need to check for the peer RW for UI frames */
775 skb_queue_tail(&local->tx_queue, pdu);
776
777 remaining_len -= frag_len;
778 msg_ptr += frag_len;
779 } while (remaining_len > 0);
780
781 kfree(msg_data);
782
783 return len;
784}
785
786int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
787{
788 struct sk_buff *skb;
789 struct nfc_llcp_local *local;
790
791 pr_debug("Send rr nr %d\n", sock->recv_n);
792
793 local = sock->local;
794 if (local == NULL)
795 return -ENODEV;
796
797 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
798 if (skb == NULL)
799 return -ENOMEM;
800
801 skb_put(skb, LLCP_SEQUENCE_SIZE);
802
803 skb->data[2] = sock->recv_n;
804
805 skb_queue_head(&local->tx_queue, skb);
806
807 return 0;
808}