NFC: Avoid falling back to SYMM when sk is NULL
[deliverable/linux.git] / net / nfc / llcp / commands.c
CommitLineData
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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, write to the
16 * Free Software Foundation, Inc.,
17 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 */
19
20#define pr_fmt(fmt) "llcp: %s: " fmt, __func__
21
22#include <linux/init.h>
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/nfc.h>
26
27#include <net/nfc/nfc.h>
28
29#include "../nfc.h"
30#include "llcp.h"
31
32static u8 llcp_tlv_length[LLCP_TLV_MAX] = {
33 0,
34 1, /* VERSION */
35 2, /* MIUX */
36 2, /* WKS */
37 1, /* LTO */
38 1, /* RW */
39 0, /* SN */
40 1, /* OPT */
41 0, /* SDREQ */
42 2, /* SDRES */
43
44};
45
46static u8 llcp_tlv8(u8 *tlv, u8 type)
47{
48 if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
49 return 0;
50
51 return tlv[2];
52}
53
76762b73 54static u16 llcp_tlv16(u8 *tlv, u8 type)
d646960f
SO
55{
56 if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
57 return 0;
58
59 return be16_to_cpu(*((__be16 *)(tlv + 2)));
60}
61
62
63static u8 llcp_tlv_version(u8 *tlv)
64{
65 return llcp_tlv8(tlv, LLCP_TLV_VERSION);
66}
67
68static u16 llcp_tlv_miux(u8 *tlv)
69{
76762b73 70 return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
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71}
72
73static u16 llcp_tlv_wks(u8 *tlv)
74{
75 return llcp_tlv16(tlv, LLCP_TLV_WKS);
76}
77
78static u16 llcp_tlv_lto(u8 *tlv)
79{
80 return llcp_tlv8(tlv, LLCP_TLV_LTO);
81}
82
83static u8 llcp_tlv_opt(u8 *tlv)
84{
85 return llcp_tlv8(tlv, LLCP_TLV_OPT);
86}
87
88static u8 llcp_tlv_rw(u8 *tlv)
89{
90 return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
91}
92
93u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length)
94{
95 u8 *tlv, length;
96
97 pr_debug("type %d\n", type);
98
99 if (type >= LLCP_TLV_MAX)
100 return NULL;
101
102 length = llcp_tlv_length[type];
103 if (length == 0 && value_length == 0)
104 return NULL;
324b0af6 105 else if (length == 0)
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106 length = value_length;
107
108 *tlv_length = 2 + length;
109 tlv = kzalloc(2 + length, GFP_KERNEL);
110 if (tlv == NULL)
111 return tlv;
112
113 tlv[0] = type;
114 tlv[1] = length;
115 memcpy(tlv + 2, value, length);
116
117 return tlv;
118}
119
7a06e586
SO
120int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
121 u8 *tlv_array, u16 tlv_array_len)
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122{
123 u8 *tlv = tlv_array, type, length, offset = 0;
124
125 pr_debug("TLV array length %d\n", tlv_array_len);
126
127 if (local == NULL)
128 return -ENODEV;
129
130 while (offset < tlv_array_len) {
131 type = tlv[0];
132 length = tlv[1];
133
134 pr_debug("type 0x%x length %d\n", type, length);
135
136 switch (type) {
137 case LLCP_TLV_VERSION:
138 local->remote_version = llcp_tlv_version(tlv);
139 break;
140 case LLCP_TLV_MIUX:
141 local->remote_miu = llcp_tlv_miux(tlv) + 128;
142 break;
143 case LLCP_TLV_WKS:
144 local->remote_wks = llcp_tlv_wks(tlv);
145 break;
146 case LLCP_TLV_LTO:
147 local->remote_lto = llcp_tlv_lto(tlv) * 10;
148 break;
149 case LLCP_TLV_OPT:
150 local->remote_opt = llcp_tlv_opt(tlv);
151 break;
7a06e586
SO
152 default:
153 pr_err("Invalid gt tlv value 0x%x\n", type);
154 break;
155 }
156
157 offset += length + 2;
158 tlv += length + 2;
159 }
160
161 pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n",
162 local->remote_version, local->remote_miu,
163 local->remote_lto, local->remote_opt,
164 local->remote_wks);
165
166 return 0;
167}
168
169int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
170 u8 *tlv_array, u16 tlv_array_len)
171{
172 u8 *tlv = tlv_array, type, length, offset = 0;
173
174 pr_debug("TLV array length %d\n", tlv_array_len);
175
176 if (sock == NULL)
177 return -ENOTCONN;
178
179 while (offset < tlv_array_len) {
180 type = tlv[0];
181 length = tlv[1];
182
183 pr_debug("type 0x%x length %d\n", type, length);
184
185 switch (type) {
93d7e490
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186 case LLCP_TLV_MIUX:
187 sock->miu = llcp_tlv_miux(tlv) + 128;
188 break;
d646960f 189 case LLCP_TLV_RW:
7a06e586 190 sock->rw = llcp_tlv_rw(tlv);
d646960f 191 break;
9dda50f4
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192 case LLCP_TLV_SN:
193 break;
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194 default:
195 pr_err("Invalid gt tlv value 0x%x\n", type);
196 break;
197 }
198
199 offset += length + 2;
200 tlv += length + 2;
201 }
202
93d7e490 203 pr_debug("sock %p rw %d miu %d\n", sock, sock->rw, sock->miu);
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204
205 return 0;
206}
207
208static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
427a2eb1 209 u8 dsap, u8 ssap, u8 ptype)
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210{
211 u8 header[2];
212
213 pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
214
215 header[0] = (u8)((dsap << 2) | (ptype >> 2));
216 header[1] = (u8)((ptype << 6) | ssap);
217
218 pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
219
220 memcpy(skb_put(pdu, LLCP_HEADER_SIZE), header, LLCP_HEADER_SIZE);
221
222 return pdu;
223}
224
427a2eb1
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225static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv,
226 u8 tlv_length)
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227{
228 /* XXX Add an skb length check */
229
230 if (tlv == NULL)
231 return NULL;
232
233 memcpy(skb_put(pdu, tlv_length), tlv, tlv_length);
234
235 return pdu;
236}
237
238static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock,
427a2eb1 239 u8 cmd, u16 size)
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240{
241 struct sk_buff *skb;
242 int err;
243
244 if (sock->ssap == 0)
245 return NULL;
246
247 skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
427a2eb1 248 size + LLCP_HEADER_SIZE, &err);
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249 if (skb == NULL) {
250 pr_err("Could not allocate PDU\n");
251 return NULL;
252 }
253
254 skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
255
256 return skb;
257}
258
259int nfc_llcp_disconnect(struct nfc_llcp_sock *sock)
260{
261 struct sk_buff *skb;
262 struct nfc_dev *dev;
263 struct nfc_llcp_local *local;
264 u16 size = 0;
265
266 pr_debug("Sending DISC\n");
267
268 local = sock->local;
269 if (local == NULL)
270 return -ENODEV;
271
272 dev = sock->dev;
273 if (dev == NULL)
274 return -ENODEV;
275
276 size += LLCP_HEADER_SIZE;
277 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
278
279 skb = alloc_skb(size, GFP_ATOMIC);
280 if (skb == NULL)
281 return -ENOMEM;
282
283 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
284
ffc29315 285 skb = llcp_add_header(skb, sock->dsap, sock->ssap, LLCP_PDU_DISC);
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286
287 skb_queue_tail(&local->tx_queue, skb);
288
289 return 0;
290}
291
292int nfc_llcp_send_symm(struct nfc_dev *dev)
293{
294 struct sk_buff *skb;
295 struct nfc_llcp_local *local;
296 u16 size = 0;
297
298 pr_debug("Sending SYMM\n");
299
300 local = nfc_llcp_find_local(dev);
301 if (local == NULL)
302 return -ENODEV;
303
304 size += LLCP_HEADER_SIZE;
305 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
306
307 skb = alloc_skb(size, GFP_KERNEL);
308 if (skb == NULL)
309 return -ENOMEM;
310
311 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
312
313 skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
314
4463523b
TE
315 nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_TX);
316
d646960f 317 return nfc_data_exchange(dev, local->target_idx, skb,
427a2eb1 318 nfc_llcp_recv, local);
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319}
320
321int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
322{
323 struct nfc_llcp_local *local;
324 struct sk_buff *skb;
325 u8 *service_name_tlv = NULL, service_name_tlv_length;
eda21f16
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326 u8 *miux_tlv = NULL, miux_tlv_length;
327 u8 *rw_tlv = NULL, rw_tlv_length, rw;
328 __be16 miux;
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329 int err;
330 u16 size = 0;
331
332 pr_debug("Sending CONNECT\n");
333
334 local = sock->local;
335 if (local == NULL)
336 return -ENODEV;
337
338 if (sock->service_name != NULL) {
339 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
427a2eb1
SO
340 sock->service_name,
341 sock->service_name_len,
342 &service_name_tlv_length);
d646960f
SO
343 size += service_name_tlv_length;
344 }
345
eda21f16 346 miux = cpu_to_be16(LLCP_MAX_MIUX);
427a2eb1
SO
347 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
348 &miux_tlv_length);
eda21f16
SO
349 size += miux_tlv_length;
350
351 rw = LLCP_MAX_RW;
352 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
353 size += rw_tlv_length;
354
d646960f
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355 pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
356
357 skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
358 if (skb == NULL) {
359 err = -ENOMEM;
360 goto error_tlv;
361 }
362
363 if (service_name_tlv != NULL)
364 skb = llcp_add_tlv(skb, service_name_tlv,
427a2eb1 365 service_name_tlv_length);
d646960f 366
eda21f16
SO
367 skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
368 skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
369
d646960f
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370 skb_queue_tail(&local->tx_queue, skb);
371
372 return 0;
373
374error_tlv:
375 pr_err("error %d\n", err);
376
377 kfree(service_name_tlv);
eda21f16
SO
378 kfree(miux_tlv);
379 kfree(rw_tlv);
d646960f
SO
380
381 return err;
382}
383
384int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
385{
386 struct nfc_llcp_local *local;
387 struct sk_buff *skb;
eda21f16
SO
388 u8 *miux_tlv = NULL, miux_tlv_length;
389 u8 *rw_tlv = NULL, rw_tlv_length, rw;
390 __be16 miux;
391 int err;
392 u16 size = 0;
d646960f
SO
393
394 pr_debug("Sending CC\n");
395
396 local = sock->local;
397 if (local == NULL)
398 return -ENODEV;
399
eda21f16 400 miux = cpu_to_be16(LLCP_MAX_MIUX);
427a2eb1
SO
401 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
402 &miux_tlv_length);
eda21f16
SO
403 size += miux_tlv_length;
404
405 rw = LLCP_MAX_RW;
406 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
407 size += rw_tlv_length;
408
409 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
410 if (skb == NULL) {
411 err = -ENOMEM;
412 goto error_tlv;
413 }
414
415 skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
416 skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
d646960f
SO
417
418 skb_queue_tail(&local->tx_queue, skb);
419
420 return 0;
eda21f16
SO
421
422error_tlv:
423 pr_err("error %d\n", err);
424
425 kfree(miux_tlv);
426 kfree(rw_tlv);
427
428 return err;
d646960f
SO
429}
430
431int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
432{
433 struct sk_buff *skb;
434 struct nfc_dev *dev;
435 u16 size = 1; /* Reason code */
436
437 pr_debug("Sending DM reason 0x%x\n", reason);
438
439 if (local == NULL)
440 return -ENODEV;
441
442 dev = local->dev;
443 if (dev == NULL)
444 return -ENODEV;
445
446 size += LLCP_HEADER_SIZE;
447 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
448
449 skb = alloc_skb(size, GFP_KERNEL);
450 if (skb == NULL)
451 return -ENOMEM;
452
453 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
454
ffc29315 455 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
d646960f
SO
456
457 memcpy(skb_put(skb, 1), &reason, 1);
458
459 skb_queue_head(&local->tx_queue, skb);
460
461 return 0;
462}
463
464int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
465{
466 struct sk_buff *skb;
467 struct nfc_llcp_local *local;
468
469 pr_debug("Send DISC\n");
470
471 local = sock->local;
472 if (local == NULL)
473 return -ENODEV;
474
475 skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
476 if (skb == NULL)
477 return -ENOMEM;
478
479 skb_queue_head(&local->tx_queue, skb);
480
481 return 0;
482}
53a0ac2e
SO
483
484int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
427a2eb1 485 struct msghdr *msg, size_t len)
53a0ac2e
SO
486{
487 struct sk_buff *pdu;
e65b0f46
SO
488 struct sock *sk = &sock->sk;
489 struct nfc_llcp_local *local;
490 size_t frag_len = 0, remaining_len;
491 u8 *msg_data, *msg_ptr;
53a0ac2e 492
e65b0f46 493 pr_debug("Send I frame len %zd\n", len);
53a0ac2e 494
e65b0f46
SO
495 local = sock->local;
496 if (local == NULL)
497 return -ENODEV;
53a0ac2e 498
e65b0f46
SO
499 msg_data = kzalloc(len, GFP_KERNEL);
500 if (msg_data == NULL)
501 return -ENOMEM;
53a0ac2e 502
e65b0f46 503 if (memcpy_fromiovec(msg_data, msg->msg_iov, len)) {
427a2eb1
SO
504 kfree(msg_data);
505 return -EFAULT;
53a0ac2e
SO
506 }
507
e65b0f46
SO
508 remaining_len = len;
509 msg_ptr = msg_data;
510
511 while (remaining_len > 0) {
512
93d7e490 513 frag_len = min_t(size_t, sock->miu, remaining_len);
53a0ac2e 514
e65b0f46
SO
515 pr_debug("Fragment %zd bytes remaining %zd",
516 frag_len, remaining_len);
53a0ac2e 517
e65b0f46
SO
518 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
519 frag_len + LLCP_SEQUENCE_SIZE);
520 if (pdu == NULL)
521 return -ENOMEM;
522
523 skb_put(pdu, LLCP_SEQUENCE_SIZE);
524
525 memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
526
bdbc59b3 527 skb_queue_tail(&sock->tx_queue, pdu);
e65b0f46
SO
528
529 lock_sock(sk);
530
531 nfc_llcp_queue_i_frames(sock);
532
533 release_sock(sk);
534
535 remaining_len -= frag_len;
b4838d12 536 msg_ptr += frag_len;
e65b0f46 537 }
53a0ac2e 538
e65b0f46 539 kfree(msg_data);
53a0ac2e 540
43472fff 541 return len;
53a0ac2e 542}
d094afa1
SO
543
544int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
545{
546 struct sk_buff *skb;
547 struct nfc_llcp_local *local;
548
549 pr_debug("Send rr nr %d\n", sock->recv_n);
550
551 local = sock->local;
552 if (local == NULL)
553 return -ENODEV;
554
555 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
556 if (skb == NULL)
557 return -ENOMEM;
558
559 skb_put(skb, LLCP_SEQUENCE_SIZE);
560
279cf174 561 skb->data[2] = sock->recv_n;
d094afa1
SO
562
563 skb_queue_head(&local->tx_queue, skb);
564
565 return 0;
566}
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