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
18 static 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
32 static 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
40 static 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
49 static u8 llcp_tlv_version(const u8 *tlv)
50 {
51 return llcp_tlv8(tlv, LLCP_TLV_VERSION);
52 }
53
54 static u16 llcp_tlv_miux(const u8 *tlv)
55 {
56 return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
57 }
58
59 static u16 llcp_tlv_wks(const u8 *tlv)
60 {
61 return llcp_tlv16(tlv, LLCP_TLV_WKS);
62 }
63
64 static u16 llcp_tlv_lto(const u8 *tlv)
65 {
66 return llcp_tlv8(tlv, LLCP_TLV_LTO);
67 }
68
69 static u8 llcp_tlv_opt(const u8 *tlv)
70 {
71 return llcp_tlv8(tlv, LLCP_TLV_OPT);
72 }
73
74 static u8 llcp_tlv_rw(const u8 *tlv)
75 {
76 return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
77 }
78
79 u8 *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
106 struct 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
133 struct 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
174 void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
175 {
176 kfree(sdp->tlv);
177 kfree(sdp);
178 }
179
180 void 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
192 int 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
242 int 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
283 static 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
300 static 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
313 static 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
334 int 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
357 int 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 int err;
363
364 local = nfc_llcp_find_local(dev);
365 if (local == NULL)
366 return -ENODEV;
367
368 size += LLCP_HEADER_SIZE;
369 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
370
371 skb = alloc_skb(size, GFP_KERNEL);
372 if (skb == NULL) {
373 err = -ENOMEM;
374 goto out;
375 }
376
377 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
378
379 skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
380
381 __net_timestamp(skb);
382
383 nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX);
384
385 err = nfc_data_exchange(dev, local->target_idx, skb,
386 nfc_llcp_recv, local);
387 out:
388 nfc_llcp_local_put(local);
389 return err;
390 }
391
392 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
393 {
394 struct nfc_llcp_local *local;
395 struct sk_buff *skb;
396 const u8 *service_name_tlv = NULL;
397 const u8 *miux_tlv = NULL;
398 const u8 *rw_tlv = NULL;
399 u8 service_name_tlv_length = 0;
400 u8 miux_tlv_length, rw_tlv_length, rw;
401 int err;
402 u16 size = 0;
403 __be16 miux;
404
405 local = sock->local;
406 if (local == NULL)
407 return -ENODEV;
408
409 if (sock->service_name != NULL) {
410 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
411 sock->service_name,
412 sock->service_name_len,
413 &service_name_tlv_length);
414 if (!service_name_tlv) {
415 err = -ENOMEM;
416 goto error_tlv;
417 }
418 size += service_name_tlv_length;
419 }
420
421 /* If the socket parameters are not set, use the local ones */
422 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
423 local->miux : sock->miux;
424 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
425
426 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
427 &miux_tlv_length);
428 if (!miux_tlv) {
429 err = -ENOMEM;
430 goto error_tlv;
431 }
432 size += miux_tlv_length;
433
434 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
435 if (!rw_tlv) {
436 err = -ENOMEM;
437 goto error_tlv;
438 }
439 size += rw_tlv_length;
440
441 pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
442
443 skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
444 if (skb == NULL) {
445 err = -ENOMEM;
446 goto error_tlv;
447 }
448
449 llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length);
450 llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
451 llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
452
453 skb_queue_tail(&local->tx_queue, skb);
454
455 err = 0;
456
457 error_tlv:
458 if (err)
459 pr_err("error %d\n", err);
460
461 kfree(service_name_tlv);
462 kfree(miux_tlv);
463 kfree(rw_tlv);
464
465 return err;
466 }
467
468 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
469 {
470 struct nfc_llcp_local *local;
471 struct sk_buff *skb;
472 const u8 *miux_tlv = NULL;
473 const u8 *rw_tlv = NULL;
474 u8 miux_tlv_length, rw_tlv_length, rw;
475 int err;
476 u16 size = 0;
477 __be16 miux;
478
479 local = sock->local;
480 if (local == NULL)
481 return -ENODEV;
482
483 /* If the socket parameters are not set, use the local ones */
484 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
485 local->miux : sock->miux;
486 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
487
488 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
489 &miux_tlv_length);
490 if (!miux_tlv) {
491 err = -ENOMEM;
492 goto error_tlv;
493 }
494 size += miux_tlv_length;
495
496 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
497 if (!rw_tlv) {
498 err = -ENOMEM;
499 goto error_tlv;
500 }
501 size += rw_tlv_length;
502
503 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
504 if (skb == NULL) {
505 err = -ENOMEM;
506 goto error_tlv;
507 }
508
509 llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
510 llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
511
512 skb_queue_tail(&local->tx_queue, skb);
513
514 err = 0;
515
516 error_tlv:
517 if (err)
518 pr_err("error %d\n", err);
519
520 kfree(miux_tlv);
521 kfree(rw_tlv);
522
523 return err;
524 }
525
526 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
527 size_t tlv_length)
528 {
529 struct sk_buff *skb;
530 struct nfc_dev *dev;
531 u16 size = 0;
532
533 if (local == NULL)
534 return ERR_PTR(-ENODEV);
535
536 dev = local->dev;
537 if (dev == NULL)
538 return ERR_PTR(-ENODEV);
539
540 size += LLCP_HEADER_SIZE;
541 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
542 size += tlv_length;
543
544 skb = alloc_skb(size, GFP_KERNEL);
545 if (skb == NULL)
546 return ERR_PTR(-ENOMEM);
547
548 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
549
550 skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
551
552 return skb;
553 }
554
555 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
556 struct hlist_head *tlv_list, size_t tlvs_len)
557 {
558 struct nfc_llcp_sdp_tlv *sdp;
559 struct hlist_node *n;
560 struct sk_buff *skb;
561
562 skb = nfc_llcp_allocate_snl(local, tlvs_len);
563 if (IS_ERR(skb))
564 return PTR_ERR(skb);
565
566 hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
567 skb_put_data(skb, sdp->tlv, sdp->tlv_len);
568
569 hlist_del(&sdp->node);
570
571 nfc_llcp_free_sdp_tlv(sdp);
572 }
573
574 skb_queue_tail(&local->tx_queue, skb);
575
576 return 0;
577 }
578
579 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
580 struct hlist_head *tlv_list, size_t tlvs_len)
581 {
582 struct nfc_llcp_sdp_tlv *sdreq;
583 struct hlist_node *n;
584 struct sk_buff *skb;
585
586 skb = nfc_llcp_allocate_snl(local, tlvs_len);
587 if (IS_ERR(skb))
588 return PTR_ERR(skb);
589
590 mutex_lock(&local->sdreq_lock);
591
592 if (hlist_empty(&local->pending_sdreqs))
593 mod_timer(&local->sdreq_timer,
594 jiffies + msecs_to_jiffies(3 * local->remote_lto));
595
596 hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
597 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
598
599 skb_put_data(skb, sdreq->tlv, sdreq->tlv_len);
600
601 hlist_del(&sdreq->node);
602
603 hlist_add_head(&sdreq->node, &local->pending_sdreqs);
604 }
605
606 mutex_unlock(&local->sdreq_lock);
607
608 skb_queue_tail(&local->tx_queue, skb);
609
610 return 0;
611 }
612
613 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
614 {
615 struct sk_buff *skb;
616 struct nfc_dev *dev;
617 u16 size = 1; /* Reason code */
618
619 pr_debug("Sending DM reason 0x%x\n", reason);
620
621 if (local == NULL)
622 return -ENODEV;
623
624 dev = local->dev;
625 if (dev == NULL)
626 return -ENODEV;
627
628 size += LLCP_HEADER_SIZE;
629 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
630
631 skb = alloc_skb(size, GFP_KERNEL);
632 if (skb == NULL)
633 return -ENOMEM;
634
635 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
636
637 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
638
639 skb_put_data(skb, &reason, 1);
640
641 skb_queue_head(&local->tx_queue, skb);
642
643 return 0;
644 }
645
646 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
647 struct msghdr *msg, size_t len)
648 {
649 struct sk_buff *pdu;
650 struct sock *sk = &sock->sk;
651 struct nfc_llcp_local *local;
652 size_t frag_len = 0, remaining_len;
653 u8 *msg_data, *msg_ptr;
654 u16 remote_miu;
655
656 pr_debug("Send I frame len %zd\n", len);
657
658 local = sock->local;
659 if (local == NULL)
660 return -ENODEV;
661
662 /* Remote is ready but has not acknowledged our frames */
663 if((sock->remote_ready &&
664 skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw &&
665 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
666 pr_err("Pending queue is full %d frames\n",
667 skb_queue_len(&sock->tx_pending_queue));
668 return -ENOBUFS;
669 }
670
671 /* Remote is not ready and we've been queueing enough frames */
672 if ((!sock->remote_ready &&
673 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
674 pr_err("Tx queue is full %d frames\n",
675 skb_queue_len(&sock->tx_queue));
676 return -ENOBUFS;
677 }
678
679 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
680 if (msg_data == NULL)
681 return -ENOMEM;
682
683 if (memcpy_from_msg(msg_data, msg, len)) {
684 kfree(msg_data);
685 return -EFAULT;
686 }
687
688 remaining_len = len;
689 msg_ptr = msg_data;
690
691 do {
692 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
693 LLCP_DEFAULT_MIU : sock->remote_miu;
694
695 frag_len = min_t(size_t, remote_miu, remaining_len);
696
697 pr_debug("Fragment %zd bytes remaining %zd",
698 frag_len, remaining_len);
699
700 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
701 frag_len + LLCP_SEQUENCE_SIZE);
702 if (pdu == NULL) {
703 kfree(msg_data);
704 return -ENOMEM;
705 }
706
707 skb_put(pdu, LLCP_SEQUENCE_SIZE);
708
709 if (likely(frag_len > 0))
710 skb_put_data(pdu, msg_ptr, frag_len);
711
712 skb_queue_tail(&sock->tx_queue, pdu);
713
714 lock_sock(sk);
715
716 nfc_llcp_queue_i_frames(sock);
717
718 release_sock(sk);
719
720 remaining_len -= frag_len;
721 msg_ptr += frag_len;
722 } while (remaining_len > 0);
723
724 kfree(msg_data);
725
726 return len;
727 }
728
729 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
730 struct msghdr *msg, size_t len)
731 {
732 struct sk_buff *pdu;
733 struct nfc_llcp_local *local;
734 size_t frag_len = 0, remaining_len;
735 u8 *msg_ptr, *msg_data;
736 u16 remote_miu;
737 int err;
738
739 pr_debug("Send UI frame len %zd\n", len);
740
741 local = sock->local;
742 if (local == NULL)
743 return -ENODEV;
744
745 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
746 if (msg_data == NULL)
747 return -ENOMEM;
748
749 if (memcpy_from_msg(msg_data, msg, len)) {
750 kfree(msg_data);
751 return -EFAULT;
752 }
753
754 remaining_len = len;
755 msg_ptr = msg_data;
756
757 do {
758 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
759 local->remote_miu : sock->remote_miu;
760
761 frag_len = min_t(size_t, remote_miu, remaining_len);
762
763 pr_debug("Fragment %zd bytes remaining %zd",
764 frag_len, remaining_len);
765
766 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0,
767 frag_len + LLCP_HEADER_SIZE, &err);
768 if (pdu == NULL) {
769 pr_err("Could not allocate PDU (error=%d)\n", err);
770 len -= remaining_len;
771 if (len == 0)
772 len = err;
773 break;
774 }
775
776 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
777
778 if (likely(frag_len > 0))
779 skb_put_data(pdu, msg_ptr, frag_len);
780
781 /* No need to check for the peer RW for UI frames */
782 skb_queue_tail(&local->tx_queue, pdu);
783
784 remaining_len -= frag_len;
785 msg_ptr += frag_len;
786 } while (remaining_len > 0);
787
788 kfree(msg_data);
789
790 return len;
791 }
792
793 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
794 {
795 struct sk_buff *skb;
796 struct nfc_llcp_local *local;
797
798 pr_debug("Send rr nr %d\n", sock->recv_n);
799
800 local = sock->local;
801 if (local == NULL)
802 return -ENODEV;
803
804 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
805 if (skb == NULL)
806 return -ENOMEM;
807
808 skb_put(skb, LLCP_SEQUENCE_SIZE);
809
810 skb->data[2] = sock->recv_n;
811
812 skb_queue_head(&local->tx_queue, skb);
813
814 return 0;
815 }
816
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