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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,
33 2,
34 2,
35 1,
36 1,
37 0,
38 1,
39 0,
40 2,
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 = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
153 if (sdreq == NULL)
154 return NULL;
155
156 sdreq->tlv_len = uri_len + 3;
157
158 if (uri[uri_len - 1] == 0)
159 sdreq->tlv_len--;
160
161 sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL);
162 if (sdreq->tlv == NULL) {
163 kfree(sdreq);
164 return NULL;
165 }
166
167 sdreq->tlv[0] = LLCP_TLV_SDREQ;
168 sdreq->tlv[1] = sdreq->tlv_len - 2;
169 sdreq->tlv[2] = tid;
170
171 sdreq->tid = tid;
172 sdreq->uri = sdreq->tlv + 3;
173 memcpy(sdreq->uri, uri, uri_len);
174
175 sdreq->time = jiffies;
176
177 INIT_HLIST_NODE(&sdreq->node);
178
179 return sdreq;
180}
181
182void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
183{
184 kfree(sdp->tlv);
185 kfree(sdp);
186}
187
188void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head)
189{
190 struct nfc_llcp_sdp_tlv *sdp;
191 struct hlist_node *n;
192
193 hlist_for_each_entry_safe(sdp, n, head, node) {
194 hlist_del(&sdp->node);
195
196 nfc_llcp_free_sdp_tlv(sdp);
197 }
198}
199
200int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
201 u8 *tlv_array, u16 tlv_array_len)
202{
203 u8 *tlv = tlv_array, type, length, offset = 0;
204
205 pr_debug("TLV array length %d\n", tlv_array_len);
206
207 if (local == NULL)
208 return -ENODEV;
209
210 while (offset < tlv_array_len) {
211 type = tlv[0];
212 length = tlv[1];
213
214 pr_debug("type 0x%x length %d\n", type, length);
215
216 switch (type) {
217 case LLCP_TLV_VERSION:
218 local->remote_version = llcp_tlv_version(tlv);
219 break;
220 case LLCP_TLV_MIUX:
221 local->remote_miu = llcp_tlv_miux(tlv) + 128;
222 break;
223 case LLCP_TLV_WKS:
224 local->remote_wks = llcp_tlv_wks(tlv);
225 break;
226 case LLCP_TLV_LTO:
227 local->remote_lto = llcp_tlv_lto(tlv) * 10;
228 break;
229 case LLCP_TLV_OPT:
230 local->remote_opt = llcp_tlv_opt(tlv);
231 break;
232 default:
233 pr_err("Invalid gt tlv value 0x%x\n", type);
234 break;
235 }
236
237 offset += length + 2;
238 tlv += length + 2;
239 }
240
241 pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n",
242 local->remote_version, local->remote_miu,
243 local->remote_lto, local->remote_opt,
244 local->remote_wks);
245
246 return 0;
247}
248
249int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
250 u8 *tlv_array, u16 tlv_array_len)
251{
252 u8 *tlv = tlv_array, type, length, offset = 0;
253
254 pr_debug("TLV array length %d\n", tlv_array_len);
255
256 if (sock == NULL)
257 return -ENOTCONN;
258
259 while (offset < tlv_array_len) {
260 type = tlv[0];
261 length = tlv[1];
262
263 pr_debug("type 0x%x length %d\n", type, length);
264
265 switch (type) {
266 case LLCP_TLV_MIUX:
267 sock->remote_miu = llcp_tlv_miux(tlv) + 128;
268 break;
269 case LLCP_TLV_RW:
270 sock->remote_rw = llcp_tlv_rw(tlv);
271 break;
272 case LLCP_TLV_SN:
273 break;
274 default:
275 pr_err("Invalid gt tlv value 0x%x\n", type);
276 break;
277 }
278
279 offset += length + 2;
280 tlv += length + 2;
281 }
282
283 pr_debug("sock %p rw %d miu %d\n", sock,
284 sock->remote_rw, sock->remote_miu);
285
286 return 0;
287}
288
289static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
290 u8 dsap, u8 ssap, u8 ptype)
291{
292 u8 header[2];
293
294 pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
295
296 header[0] = (u8)((dsap << 2) | (ptype >> 2));
297 header[1] = (u8)((ptype << 6) | ssap);
298
299 pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
300
301 memcpy(skb_put(pdu, LLCP_HEADER_SIZE), header, LLCP_HEADER_SIZE);
302
303 return pdu;
304}
305
306static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv,
307 u8 tlv_length)
308{
309
310
311 if (tlv == NULL)
312 return NULL;
313
314 memcpy(skb_put(pdu, tlv_length), tlv, tlv_length);
315
316 return pdu;
317}
318
319static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock,
320 u8 cmd, u16 size)
321{
322 struct sk_buff *skb;
323 int err;
324
325 if (sock->ssap == 0)
326 return NULL;
327
328 skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
329 size + LLCP_HEADER_SIZE, &err);
330 if (skb == NULL) {
331 pr_err("Could not allocate PDU\n");
332 return NULL;
333 }
334
335 skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
336
337 return skb;
338}
339
340int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
341{
342 struct sk_buff *skb;
343 struct nfc_dev *dev;
344 struct nfc_llcp_local *local;
345
346 pr_debug("Sending DISC\n");
347
348 local = sock->local;
349 if (local == NULL)
350 return -ENODEV;
351
352 dev = sock->dev;
353 if (dev == NULL)
354 return -ENODEV;
355
356 skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
357 if (skb == NULL)
358 return -ENOMEM;
359
360 skb_queue_tail(&local->tx_queue, skb);
361
362 return 0;
363}
364
365int nfc_llcp_send_symm(struct nfc_dev *dev)
366{
367 struct sk_buff *skb;
368 struct nfc_llcp_local *local;
369 u16 size = 0;
370
371 pr_debug("Sending SYMM\n");
372
373 local = nfc_llcp_find_local(dev);
374 if (local == NULL)
375 return -ENODEV;
376
377 size += LLCP_HEADER_SIZE;
378 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
379
380 skb = alloc_skb(size, GFP_KERNEL);
381 if (skb == NULL)
382 return -ENOMEM;
383
384 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
385
386 skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
387
388 __net_timestamp(skb);
389
390 nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX);
391
392 return nfc_data_exchange(dev, local->target_idx, skb,
393 nfc_llcp_recv, local);
394}
395
396int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
397{
398 struct nfc_llcp_local *local;
399 struct sk_buff *skb;
400 u8 *service_name_tlv = NULL, service_name_tlv_length;
401 u8 *miux_tlv = NULL, miux_tlv_length;
402 u8 *rw_tlv = NULL, rw_tlv_length, rw;
403 int err;
404 u16 size = 0;
405 __be16 miux;
406
407 pr_debug("Sending CONNECT\n");
408
409 local = sock->local;
410 if (local == NULL)
411 return -ENODEV;
412
413 if (sock->service_name != NULL) {
414 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
415 sock->service_name,
416 sock->service_name_len,
417 &service_name_tlv_length);
418 size += service_name_tlv_length;
419 }
420
421
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 size += miux_tlv_length;
429
430 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
431 size += rw_tlv_length;
432
433 pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
434
435 skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
436 if (skb == NULL) {
437 err = -ENOMEM;
438 goto error_tlv;
439 }
440
441 if (service_name_tlv != NULL)
442 skb = llcp_add_tlv(skb, service_name_tlv,
443 service_name_tlv_length);
444
445 skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
446 skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
447
448 skb_queue_tail(&local->tx_queue, skb);
449
450 return 0;
451
452error_tlv:
453 pr_err("error %d\n", err);
454
455 kfree(service_name_tlv);
456 kfree(miux_tlv);
457 kfree(rw_tlv);
458
459 return err;
460}
461
462int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
463{
464 struct nfc_llcp_local *local;
465 struct sk_buff *skb;
466 u8 *miux_tlv = NULL, miux_tlv_length;
467 u8 *rw_tlv = NULL, rw_tlv_length, rw;
468 int err;
469 u16 size = 0;
470 __be16 miux;
471
472 pr_debug("Sending CC\n");
473
474 local = sock->local;
475 if (local == NULL)
476 return -ENODEV;
477
478
479 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
480 local->miux : sock->miux;
481 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
482
483 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
484 &miux_tlv_length);
485 size += miux_tlv_length;
486
487 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
488 size += rw_tlv_length;
489
490 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
491 if (skb == NULL) {
492 err = -ENOMEM;
493 goto error_tlv;
494 }
495
496 skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
497 skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
498
499 skb_queue_tail(&local->tx_queue, skb);
500
501 return 0;
502
503error_tlv:
504 pr_err("error %d\n", err);
505
506 kfree(miux_tlv);
507 kfree(rw_tlv);
508
509 return err;
510}
511
512static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
513 size_t tlv_length)
514{
515 struct sk_buff *skb;
516 struct nfc_dev *dev;
517 u16 size = 0;
518
519 if (local == NULL)
520 return ERR_PTR(-ENODEV);
521
522 dev = local->dev;
523 if (dev == NULL)
524 return ERR_PTR(-ENODEV);
525
526 size += LLCP_HEADER_SIZE;
527 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
528 size += tlv_length;
529
530 skb = alloc_skb(size, GFP_KERNEL);
531 if (skb == NULL)
532 return ERR_PTR(-ENOMEM);
533
534 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
535
536 skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
537
538 return skb;
539}
540
541int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
542 struct hlist_head *tlv_list, size_t tlvs_len)
543{
544 struct nfc_llcp_sdp_tlv *sdp;
545 struct hlist_node *n;
546 struct sk_buff *skb;
547
548 skb = nfc_llcp_allocate_snl(local, tlvs_len);
549 if (IS_ERR(skb))
550 return PTR_ERR(skb);
551
552 hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
553 memcpy(skb_put(skb, sdp->tlv_len), sdp->tlv, sdp->tlv_len);
554
555 hlist_del(&sdp->node);
556
557 nfc_llcp_free_sdp_tlv(sdp);
558 }
559
560 skb_queue_tail(&local->tx_queue, skb);
561
562 return 0;
563}
564
565int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
566 struct hlist_head *tlv_list, size_t tlvs_len)
567{
568 struct nfc_llcp_sdp_tlv *sdreq;
569 struct hlist_node *n;
570 struct sk_buff *skb;
571
572 skb = nfc_llcp_allocate_snl(local, tlvs_len);
573 if (IS_ERR(skb))
574 return PTR_ERR(skb);
575
576 mutex_lock(&local->sdreq_lock);
577
578 if (hlist_empty(&local->pending_sdreqs))
579 mod_timer(&local->sdreq_timer,
580 jiffies + msecs_to_jiffies(3 * local->remote_lto));
581
582 hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
583 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
584
585 memcpy(skb_put(skb, sdreq->tlv_len), sdreq->tlv,
586 sdreq->tlv_len);
587
588 hlist_del(&sdreq->node);
589
590 hlist_add_head(&sdreq->node, &local->pending_sdreqs);
591 }
592
593 mutex_unlock(&local->sdreq_lock);
594
595 skb_queue_tail(&local->tx_queue, skb);
596
597 return 0;
598}
599
600int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
601{
602 struct sk_buff *skb;
603 struct nfc_dev *dev;
604 u16 size = 1;
605
606 pr_debug("Sending DM reason 0x%x\n", reason);
607
608 if (local == NULL)
609 return -ENODEV;
610
611 dev = local->dev;
612 if (dev == NULL)
613 return -ENODEV;
614
615 size += LLCP_HEADER_SIZE;
616 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
617
618 skb = alloc_skb(size, GFP_KERNEL);
619 if (skb == NULL)
620 return -ENOMEM;
621
622 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
623
624 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
625
626 memcpy(skb_put(skb, 1), &reason, 1);
627
628 skb_queue_head(&local->tx_queue, skb);
629
630 return 0;
631}
632
633int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
634 struct msghdr *msg, size_t len)
635{
636 struct sk_buff *pdu;
637 struct sock *sk = &sock->sk;
638 struct nfc_llcp_local *local;
639 size_t frag_len = 0, remaining_len;
640 u8 *msg_data, *msg_ptr;
641 u16 remote_miu;
642
643 pr_debug("Send I frame len %zd\n", len);
644
645 local = sock->local;
646 if (local == NULL)
647 return -ENODEV;
648
649
650 if((sock->remote_ready &&
651 skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw &&
652 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
653 pr_err("Pending queue is full %d frames\n",
654 skb_queue_len(&sock->tx_pending_queue));
655 return -ENOBUFS;
656 }
657
658
659 if ((!sock->remote_ready &&
660 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
661 pr_err("Tx queue is full %d frames\n",
662 skb_queue_len(&sock->tx_queue));
663 return -ENOBUFS;
664 }
665
666 msg_data = kzalloc(len, GFP_KERNEL);
667 if (msg_data == NULL)
668 return -ENOMEM;
669
670 if (memcpy_from_msg(msg_data, msg, len)) {
671 kfree(msg_data);
672 return -EFAULT;
673 }
674
675 remaining_len = len;
676 msg_ptr = msg_data;
677
678 do {
679 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
680 LLCP_DEFAULT_MIU : sock->remote_miu;
681
682 frag_len = min_t(size_t, remote_miu, remaining_len);
683
684 pr_debug("Fragment %zd bytes remaining %zd",
685 frag_len, remaining_len);
686
687 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
688 frag_len + LLCP_SEQUENCE_SIZE);
689 if (pdu == NULL) {
690 kfree(msg_data);
691 return -ENOMEM;
692 }
693
694 skb_put(pdu, LLCP_SEQUENCE_SIZE);
695
696 if (likely(frag_len > 0))
697 memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
698
699 skb_queue_tail(&sock->tx_queue, pdu);
700
701 lock_sock(sk);
702
703 nfc_llcp_queue_i_frames(sock);
704
705 release_sock(sk);
706
707 remaining_len -= frag_len;
708 msg_ptr += frag_len;
709 } while (remaining_len > 0);
710
711 kfree(msg_data);
712
713 return len;
714}
715
716int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
717 struct msghdr *msg, size_t len)
718{
719 struct sk_buff *pdu;
720 struct nfc_llcp_local *local;
721 size_t frag_len = 0, remaining_len;
722 u8 *msg_ptr, *msg_data;
723 u16 remote_miu;
724 int err;
725
726 pr_debug("Send UI frame len %zd\n", len);
727
728 local = sock->local;
729 if (local == NULL)
730 return -ENODEV;
731
732 msg_data = kzalloc(len, GFP_KERNEL);
733 if (msg_data == NULL)
734 return -ENOMEM;
735
736 if (memcpy_from_msg(msg_data, msg, len)) {
737 kfree(msg_data);
738 return -EFAULT;
739 }
740
741 remaining_len = len;
742 msg_ptr = msg_data;
743
744 do {
745 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
746 local->remote_miu : sock->remote_miu;
747
748 frag_len = min_t(size_t, remote_miu, remaining_len);
749
750 pr_debug("Fragment %zd bytes remaining %zd",
751 frag_len, remaining_len);
752
753 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
754 frag_len + LLCP_HEADER_SIZE, &err);
755 if (pdu == NULL) {
756 pr_err("Could not allocate PDU\n");
757 continue;
758 }
759
760 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
761
762 if (likely(frag_len > 0))
763 memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
764
765
766 skb_queue_tail(&local->tx_queue, pdu);
767
768 remaining_len -= frag_len;
769 msg_ptr += frag_len;
770 } while (remaining_len > 0);
771
772 kfree(msg_data);
773
774 return len;
775}
776
777int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
778{
779 struct sk_buff *skb;
780 struct nfc_llcp_local *local;
781
782 pr_debug("Send rr nr %d\n", sock->recv_n);
783
784 local = sock->local;
785 if (local == NULL)
786 return -ENODEV;
787
788 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
789 if (skb == NULL)
790 return -ENOMEM;
791
792 skb_put(skb, LLCP_SEQUENCE_SIZE);
793
794 skb->data[2] = sock->recv_n;
795
796 skb_queue_head(&local->tx_queue, skb);
797
798 return 0;
799}
800
