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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 
30 static 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 
llcp_tlv8(u8 * tlv,u8 type)44 static 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 
llcp_tlv16(u8 * tlv,u8 type)52 static 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 
llcp_tlv_version(u8 * tlv)61 static u8 llcp_tlv_version(u8 *tlv)
62 {
63 	return llcp_tlv8(tlv, LLCP_TLV_VERSION);
64 }
65 
llcp_tlv_miux(u8 * tlv)66 static u16 llcp_tlv_miux(u8 *tlv)
67 {
68 	return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
69 }
70 
llcp_tlv_wks(u8 * tlv)71 static u16 llcp_tlv_wks(u8 *tlv)
72 {
73 	return llcp_tlv16(tlv, LLCP_TLV_WKS);
74 }
75 
llcp_tlv_lto(u8 * tlv)76 static u16 llcp_tlv_lto(u8 *tlv)
77 {
78 	return llcp_tlv8(tlv, LLCP_TLV_LTO);
79 }
80 
llcp_tlv_opt(u8 * tlv)81 static u8 llcp_tlv_opt(u8 *tlv)
82 {
83 	return llcp_tlv8(tlv, LLCP_TLV_OPT);
84 }
85 
llcp_tlv_rw(u8 * tlv)86 static u8 llcp_tlv_rw(u8 *tlv)
87 {
88 	return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
89 }
90 
nfc_llcp_build_tlv(u8 type,u8 * value,u8 value_length,u8 * tlv_length)91 u8 *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 
nfc_llcp_build_sdres_tlv(u8 tid,u8 sap)118 struct 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 
nfc_llcp_build_sdreq_tlv(u8 tid,char * uri,size_t uri_len)145 struct 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 
nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv * sdp)182 void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
183 {
184 	kfree(sdp->tlv);
185 	kfree(sdp);
186 }
187 
nfc_llcp_free_sdp_tlv_list(struct hlist_head * head)188 void 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 
nfc_llcp_parse_gb_tlv(struct nfc_llcp_local * local,u8 * tlv_array,u16 tlv_array_len)200 int 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 
nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock * sock,u8 * tlv_array,u16 tlv_array_len)249 int 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 
llcp_add_header(struct sk_buff * pdu,u8 dsap,u8 ssap,u8 ptype)289 static 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 
llcp_add_tlv(struct sk_buff * pdu,u8 * tlv,u8 tlv_length)306 static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv,
307 				    u8 tlv_length)
308 {
309 	/* XXX Add an skb length check */
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 
llcp_allocate_pdu(struct nfc_llcp_sock * sock,u8 cmd,u16 size)319 static 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 
nfc_llcp_send_disconnect(struct nfc_llcp_sock * sock)340 int 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 
nfc_llcp_send_symm(struct nfc_dev * dev)365 int 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 
nfc_llcp_send_connect(struct nfc_llcp_sock * sock)396 int 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, miux;
405 
406 	pr_debug("Sending CONNECT\n");
407 
408 	local = sock->local;
409 	if (local == NULL)
410 		return -ENODEV;
411 
412 	if (sock->service_name != NULL) {
413 		service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
414 						      sock->service_name,
415 						      sock->service_name_len,
416 						      &service_name_tlv_length);
417 		size += service_name_tlv_length;
418 	}
419 
420 	/* If the socket parameters are not set, use the local ones */
421 	miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
422 		local->miux : sock->miux;
423 	rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
424 
425 	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
426 				      &miux_tlv_length);
427 	size += miux_tlv_length;
428 
429 	rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
430 	size += rw_tlv_length;
431 
432 	pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
433 
434 	skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
435 	if (skb == NULL) {
436 		err = -ENOMEM;
437 		goto error_tlv;
438 	}
439 
440 	if (service_name_tlv != NULL)
441 		skb = llcp_add_tlv(skb, service_name_tlv,
442 				   service_name_tlv_length);
443 
444 	skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
445 	skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
446 
447 	skb_queue_tail(&local->tx_queue, skb);
448 
449 	return 0;
450 
451 error_tlv:
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 
nfc_llcp_send_cc(struct nfc_llcp_sock * sock)461 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
462 {
463 	struct nfc_llcp_local *local;
464 	struct sk_buff *skb;
465 	u8 *miux_tlv = NULL, miux_tlv_length;
466 	u8 *rw_tlv = NULL, rw_tlv_length, rw;
467 	int err;
468 	u16 size = 0, miux;
469 
470 	pr_debug("Sending CC\n");
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 	size += miux_tlv_length;
484 
485 	rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
486 	size += rw_tlv_length;
487 
488 	skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
489 	if (skb == NULL) {
490 		err = -ENOMEM;
491 		goto error_tlv;
492 	}
493 
494 	skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
495 	skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
496 
497 	skb_queue_tail(&local->tx_queue, skb);
498 
499 	return 0;
500 
501 error_tlv:
502 	pr_err("error %d\n", err);
503 
504 	kfree(miux_tlv);
505 	kfree(rw_tlv);
506 
507 	return err;
508 }
509 
nfc_llcp_allocate_snl(struct nfc_llcp_local * local,size_t tlv_length)510 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
511 					     size_t tlv_length)
512 {
513 	struct sk_buff *skb;
514 	struct nfc_dev *dev;
515 	u16 size = 0;
516 
517 	if (local == NULL)
518 		return ERR_PTR(-ENODEV);
519 
520 	dev = local->dev;
521 	if (dev == NULL)
522 		return ERR_PTR(-ENODEV);
523 
524 	size += LLCP_HEADER_SIZE;
525 	size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
526 	size += tlv_length;
527 
528 	skb = alloc_skb(size, GFP_KERNEL);
529 	if (skb == NULL)
530 		return ERR_PTR(-ENOMEM);
531 
532 	skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
533 
534 	skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
535 
536 	return skb;
537 }
538 
nfc_llcp_send_snl_sdres(struct nfc_llcp_local * local,struct hlist_head * tlv_list,size_t tlvs_len)539 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
540 			    struct hlist_head *tlv_list, size_t tlvs_len)
541 {
542 	struct nfc_llcp_sdp_tlv *sdp;
543 	struct hlist_node *n;
544 	struct sk_buff *skb;
545 
546 	skb = nfc_llcp_allocate_snl(local, tlvs_len);
547 	if (IS_ERR(skb))
548 		return PTR_ERR(skb);
549 
550 	hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
551 		memcpy(skb_put(skb, sdp->tlv_len), sdp->tlv, sdp->tlv_len);
552 
553 		hlist_del(&sdp->node);
554 
555 		nfc_llcp_free_sdp_tlv(sdp);
556 	}
557 
558 	skb_queue_tail(&local->tx_queue, skb);
559 
560 	return 0;
561 }
562 
nfc_llcp_send_snl_sdreq(struct nfc_llcp_local * local,struct hlist_head * tlv_list,size_t tlvs_len)563 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
564 			    struct hlist_head *tlv_list, size_t tlvs_len)
565 {
566 	struct nfc_llcp_sdp_tlv *sdreq;
567 	struct hlist_node *n;
568 	struct sk_buff *skb;
569 
570 	skb = nfc_llcp_allocate_snl(local, tlvs_len);
571 	if (IS_ERR(skb))
572 		return PTR_ERR(skb);
573 
574 	mutex_lock(&local->sdreq_lock);
575 
576 	if (hlist_empty(&local->pending_sdreqs))
577 		mod_timer(&local->sdreq_timer,
578 			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
579 
580 	hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
581 		pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
582 
583 		memcpy(skb_put(skb, sdreq->tlv_len), sdreq->tlv,
584 		       sdreq->tlv_len);
585 
586 		hlist_del(&sdreq->node);
587 
588 		hlist_add_head(&sdreq->node, &local->pending_sdreqs);
589 	}
590 
591 	mutex_unlock(&local->sdreq_lock);
592 
593 	skb_queue_tail(&local->tx_queue, skb);
594 
595 	return 0;
596 }
597 
nfc_llcp_send_dm(struct nfc_llcp_local * local,u8 ssap,u8 dsap,u8 reason)598 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
599 {
600 	struct sk_buff *skb;
601 	struct nfc_dev *dev;
602 	u16 size = 1; /* Reason code */
603 
604 	pr_debug("Sending DM reason 0x%x\n", reason);
605 
606 	if (local == NULL)
607 		return -ENODEV;
608 
609 	dev = local->dev;
610 	if (dev == NULL)
611 		return -ENODEV;
612 
613 	size += LLCP_HEADER_SIZE;
614 	size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
615 
616 	skb = alloc_skb(size, GFP_KERNEL);
617 	if (skb == NULL)
618 		return -ENOMEM;
619 
620 	skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
621 
622 	skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
623 
624 	memcpy(skb_put(skb, 1), &reason, 1);
625 
626 	skb_queue_head(&local->tx_queue, skb);
627 
628 	return 0;
629 }
630 
nfc_llcp_send_i_frame(struct nfc_llcp_sock * sock,struct msghdr * msg,size_t len)631 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
632 			  struct msghdr *msg, size_t len)
633 {
634 	struct sk_buff *pdu;
635 	struct sock *sk = &sock->sk;
636 	struct nfc_llcp_local *local;
637 	size_t frag_len = 0, remaining_len;
638 	u8 *msg_data, *msg_ptr;
639 	u16 remote_miu;
640 
641 	pr_debug("Send I frame len %zd\n", len);
642 
643 	local = sock->local;
644 	if (local == NULL)
645 		return -ENODEV;
646 
647 	/* Remote is ready but has not acknowledged our frames */
648 	if((sock->remote_ready &&
649 	    skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw &&
650 	    skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
651 		pr_err("Pending queue is full %d frames\n",
652 		       skb_queue_len(&sock->tx_pending_queue));
653 		return -ENOBUFS;
654 	}
655 
656 	/* Remote is not ready and we've been queueing enough frames */
657 	if ((!sock->remote_ready &&
658 	     skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
659 		pr_err("Tx queue is full %d frames\n",
660 		       skb_queue_len(&sock->tx_queue));
661 		return -ENOBUFS;
662 	}
663 
664 	msg_data = kzalloc(len, GFP_KERNEL);
665 	if (msg_data == NULL)
666 		return -ENOMEM;
667 
668 	if (memcpy_fromiovec(msg_data, msg->msg_iov, len)) {
669 		kfree(msg_data);
670 		return -EFAULT;
671 	}
672 
673 	remaining_len = len;
674 	msg_ptr = msg_data;
675 
676 	do {
677 		remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
678 				LLCP_DEFAULT_MIU : sock->remote_miu;
679 
680 		frag_len = min_t(size_t, remote_miu, remaining_len);
681 
682 		pr_debug("Fragment %zd bytes remaining %zd",
683 			 frag_len, remaining_len);
684 
685 		pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
686 					frag_len + LLCP_SEQUENCE_SIZE);
687 		if (pdu == NULL) {
688 			kfree(msg_data);
689 			return -ENOMEM;
690 		}
691 
692 		skb_put(pdu, LLCP_SEQUENCE_SIZE);
693 
694 		if (likely(frag_len > 0))
695 			memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
696 
697 		skb_queue_tail(&sock->tx_queue, pdu);
698 
699 		lock_sock(sk);
700 
701 		nfc_llcp_queue_i_frames(sock);
702 
703 		release_sock(sk);
704 
705 		remaining_len -= frag_len;
706 		msg_ptr += frag_len;
707 	} while (remaining_len > 0);
708 
709 	kfree(msg_data);
710 
711 	return len;
712 }
713 
nfc_llcp_send_ui_frame(struct nfc_llcp_sock * sock,u8 ssap,u8 dsap,struct msghdr * msg,size_t len)714 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
715 			   struct msghdr *msg, size_t len)
716 {
717 	struct sk_buff *pdu;
718 	struct nfc_llcp_local *local;
719 	size_t frag_len = 0, remaining_len;
720 	u8 *msg_ptr, *msg_data;
721 	u16 remote_miu;
722 	int err;
723 
724 	pr_debug("Send UI frame len %zd\n", len);
725 
726 	local = sock->local;
727 	if (local == NULL)
728 		return -ENODEV;
729 
730 	msg_data = kzalloc(len, GFP_KERNEL);
731 	if (msg_data == NULL)
732 		return -ENOMEM;
733 
734 	if (memcpy_fromiovec(msg_data, msg->msg_iov, len)) {
735 		kfree(msg_data);
736 		return -EFAULT;
737 	}
738 
739 	remaining_len = len;
740 	msg_ptr = msg_data;
741 
742 	do {
743 		remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
744 				local->remote_miu : sock->remote_miu;
745 
746 		frag_len = min_t(size_t, remote_miu, remaining_len);
747 
748 		pr_debug("Fragment %zd bytes remaining %zd",
749 			 frag_len, remaining_len);
750 
751 		pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
752 					 frag_len + LLCP_HEADER_SIZE, &err);
753 		if (pdu == NULL) {
754 			pr_err("Could not allocate PDU\n");
755 			continue;
756 		}
757 
758 		pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
759 
760 		if (likely(frag_len > 0))
761 			memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
762 
763 		/* No need to check for the peer RW for UI frames */
764 		skb_queue_tail(&local->tx_queue, pdu);
765 
766 		remaining_len -= frag_len;
767 		msg_ptr += frag_len;
768 	} while (remaining_len > 0);
769 
770 	kfree(msg_data);
771 
772 	return len;
773 }
774 
nfc_llcp_send_rr(struct nfc_llcp_sock * sock)775 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
776 {
777 	struct sk_buff *skb;
778 	struct nfc_llcp_local *local;
779 
780 	pr_debug("Send rr nr %d\n", sock->recv_n);
781 
782 	local = sock->local;
783 	if (local == NULL)
784 		return -ENODEV;
785 
786 	skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
787 	if (skb == NULL)
788 		return -ENOMEM;
789 
790 	skb_put(skb, LLCP_SEQUENCE_SIZE);
791 
792 	skb->data[2] = sock->recv_n;
793 
794 	skb_queue_head(&local->tx_queue, skb);
795 
796 	return 0;
797 }
798