summaryrefslogtreecommitdiffstats
path: root/net/nfc/llcp/sock.c
blob: c13e02ebdef9b08e5c995f5cbb5a671db42d8e3c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
/*
 * Copyright (C) 2011  Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the
 * Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#define pr_fmt(fmt) "llcp: %s: " fmt, __func__

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/nfc.h>

#include "../nfc.h"
#include "llcp.h"

static struct proto llcp_sock_proto = {
	.name     = "NFC_LLCP",
	.owner    = THIS_MODULE,
	.obj_size = sizeof(struct nfc_llcp_sock),
};

static int llcp_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
{
	struct sock *sk = sock->sk;
	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
	struct nfc_llcp_local *local;
	struct nfc_dev *dev;
	struct sockaddr_nfc_llcp llcp_addr;
	int len, ret = 0;

	pr_debug("sk %p addr %p family %d\n", sk, addr, addr->sa_family);

	if (!addr || addr->sa_family != AF_NFC)
		return -EINVAL;

	memset(&llcp_addr, 0, sizeof(llcp_addr));
	len = min_t(unsigned int, sizeof(llcp_addr), alen);
	memcpy(&llcp_addr, addr, len);

	/* This is going to be a listening socket, dsap must be 0 */
	if (llcp_addr.dsap != 0)
		return -EINVAL;

	lock_sock(sk);

	if (sk->sk_state != LLCP_CLOSED) {
		ret = -EBADFD;
		goto error;
	}

	dev = nfc_get_device(llcp_addr.dev_idx);
	if (dev == NULL) {
		ret = -ENODEV;
		goto error;
	}

	local = nfc_llcp_find_local(dev);
	if (local == NULL) {
		ret = -ENODEV;
		goto put_dev;
	}

	llcp_sock->dev = dev;
	llcp_sock->local = local;
	llcp_sock->nfc_protocol = llcp_addr.nfc_protocol;
	llcp_sock->service_name_len = min_t(unsigned int,
					    llcp_addr.service_name_len,
					    NFC_LLCP_MAX_SERVICE_NAME);
	llcp_sock->service_name = kmemdup(llcp_addr.service_name,
					  llcp_sock->service_name_len,
					  GFP_KERNEL);

	llcp_sock->ssap = nfc_llcp_get_sdp_ssap(local, llcp_sock);
	if (llcp_sock->ssap == LLCP_MAX_SAP)
		goto put_dev;

	local->sockets[llcp_sock->ssap] = llcp_sock;

	pr_debug("Socket bound to SAP %d\n", llcp_sock->ssap);

	sk->sk_state = LLCP_BOUND;

put_dev:
	nfc_put_device(dev);

error:
	release_sock(sk);
	return ret;
}

static int llcp_sock_listen(struct socket *sock, int backlog)
{
	struct sock *sk = sock->sk;
	int ret = 0;

	pr_debug("sk %p backlog %d\n", sk, backlog);

	lock_sock(sk);

	if ((sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM)
	    || sk->sk_state != LLCP_BOUND) {
		ret = -EBADFD;
		goto error;
	}

	sk->sk_max_ack_backlog = backlog;
	sk->sk_ack_backlog = 0;

	pr_debug("Socket listening\n");
	sk->sk_state = LLCP_LISTEN;

error:
	release_sock(sk);

	return ret;
}

void nfc_llcp_accept_unlink(struct sock *sk)
{
	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);

	pr_debug("state %d\n", sk->sk_state);

	list_del_init(&llcp_sock->accept_queue);
	sk_acceptq_removed(llcp_sock->parent);
	llcp_sock->parent = NULL;

	sock_put(sk);
}

void nfc_llcp_accept_enqueue(struct sock *parent, struct sock *sk)
{
	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
	struct nfc_llcp_sock *llcp_sock_parent = nfc_llcp_sock(parent);

	/* Lock will be free from unlink */
	sock_hold(sk);

	list_add_tail(&llcp_sock->accept_queue,
		      &llcp_sock_parent->accept_queue);
	llcp_sock->parent = parent;
	sk_acceptq_added(parent);
}

struct sock *nfc_llcp_accept_dequeue(struct sock *parent,
				     struct socket *newsock)
{
	struct nfc_llcp_sock *lsk, *n, *llcp_parent;
	struct sock *sk;

	llcp_parent = nfc_llcp_sock(parent);

	list_for_each_entry_safe(lsk, n, &llcp_parent->accept_queue,
				 accept_queue) {
		sk = &lsk->sk;
		lock_sock(sk);

		if (sk->sk_state == LLCP_CLOSED) {
			release_sock(sk);
			nfc_llcp_accept_unlink(sk);
			continue;
		}

		if (sk->sk_state == LLCP_CONNECTED || !newsock) {
			nfc_llcp_accept_unlink(sk);
			if (newsock)
				sock_graft(sk, newsock);

			release_sock(sk);

			pr_debug("Returning sk state %d\n", sk->sk_state);

			return sk;
		}

		release_sock(sk);
	}

	return NULL;
}

static int llcp_sock_accept(struct socket *sock, struct socket *newsock,
			    int flags)
{
	DECLARE_WAITQUEUE(wait, current);
	struct sock *sk = sock->sk, *new_sk;
	long timeo;
	int ret = 0;

	pr_debug("parent %p\n", sk);

	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);

	if (sk->sk_state != LLCP_LISTEN) {
		ret = -EBADFD;
		goto error;
	}

	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);

	/* Wait for an incoming connection. */
	add_wait_queue_exclusive(sk_sleep(sk), &wait);
	while (!(new_sk = nfc_llcp_accept_dequeue(sk, newsock))) {
		set_current_state(TASK_INTERRUPTIBLE);

		if (!timeo) {
			ret = -EAGAIN;
			break;
		}

		if (signal_pending(current)) {
			ret = sock_intr_errno(timeo);
			break;
		}

		release_sock(sk);
		timeo = schedule_timeout(timeo);
		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
	}
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(sk_sleep(sk), &wait);

	if (ret)
		goto error;

	newsock->state = SS_CONNECTED;

	pr_debug("new socket %p\n", new_sk);

error:
	release_sock(sk);

	return ret;
}

static int llcp_sock_getname(struct socket *sock, struct sockaddr *addr,
			     int *len, int peer)
{
	struct sockaddr_nfc_llcp *llcp_addr = (struct sockaddr_nfc_llcp *)addr;
	struct sock *sk = sock->sk;
	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);

	pr_debug("%p\n", sk);

	addr->sa_family = AF_NFC;
	*len = sizeof(struct sockaddr_nfc_llcp);

	llcp_addr->dev_idx = llcp_sock->dev->idx;
	llcp_addr->dsap = llcp_sock->dsap;
	llcp_addr->ssap = llcp_sock->ssap;
	llcp_addr->service_name_len = llcp_sock->service_name_len;
	memcpy(llcp_addr->service_name, llcp_sock->service_name,
	       llcp_addr->service_name_len);

	return 0;
}

static inline unsigned int llcp_accept_poll(struct sock *parent)
{
	struct nfc_llcp_sock *llcp_sock, *n, *parent_sock;
	struct sock *sk;

	parent_sock = nfc_llcp_sock(parent);

	list_for_each_entry_safe(llcp_sock, n, &parent_sock->accept_queue,
				 accept_queue) {
		sk = &llcp_sock->sk;

		if (sk->sk_state == LLCP_CONNECTED)
			return POLLIN | POLLRDNORM;
	}

	return 0;
}

static unsigned int llcp_sock_poll(struct file *file, struct socket *sock,
				   poll_table *wait)
{
	struct sock *sk = sock->sk;
	unsigned int mask = 0;

	pr_debug("%p\n", sk);

	sock_poll_wait(file, sk_sleep(sk), wait);

	if (sk->sk_state == LLCP_LISTEN)
		return llcp_accept_poll(sk);

	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
		mask |= POLLERR;

	if (!skb_queue_empty(&sk->sk_receive_queue))
		mask |= POLLIN;

	if (sk->sk_state == LLCP_CLOSED)
		mask |= POLLHUP;

	return mask;
}

static int llcp_sock_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	struct nfc_llcp_local *local;
	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
	int err = 0;

	if (!sk)
		return 0;

	pr_debug("%p\n", sk);

	local = llcp_sock->local;
	if (local == NULL) {
		err = -ENODEV;
		goto out;
	}

	mutex_lock(&local->socket_lock);

	if (llcp_sock == local->sockets[llcp_sock->ssap])
		local->sockets[llcp_sock->ssap] = NULL;
	else
		list_del_init(&llcp_sock->list);

	mutex_unlock(&local->socket_lock);

	lock_sock(sk);

	/* Send a DISC */
	if (sk->sk_state == LLCP_CONNECTED)
		nfc_llcp_disconnect(llcp_sock);

	if (sk->sk_state == LLCP_LISTEN) {
		struct nfc_llcp_sock *lsk, *n;
		struct sock *accept_sk;

		list_for_each_entry_safe(lsk, n, &llcp_sock->accept_queue,
					 accept_queue) {
			accept_sk = &lsk->sk;
			lock_sock(accept_sk);

			nfc_llcp_disconnect(lsk);
			nfc_llcp_accept_unlink(accept_sk);

			release_sock(accept_sk);

			sock_orphan(accept_sk);
		}
	}

	/* Freeing the SAP */
	if ((sk->sk_state == LLCP_CONNECTED
	     && llcp_sock->ssap > LLCP_LOCAL_SAP_OFFSET) ||
	    sk->sk_state == LLCP_BOUND || sk->sk_state == LLCP_LISTEN)
		nfc_llcp_put_ssap(llcp_sock->local, llcp_sock->ssap);

	release_sock(sk);

out:
	sock_orphan(sk);
	sock_put(sk);

	return err;
}

static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr,
			     int len, int flags)
{
	struct sock *sk = sock->sk;
	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
	struct sockaddr_nfc_llcp *addr = (struct sockaddr_nfc_llcp *)_addr;
	struct nfc_dev *dev;
	struct nfc_llcp_local *local;
	int ret = 0;

	pr_debug("sock %p sk %p flags 0x%x\n", sock, sk, flags);

	if (!addr || len < sizeof(struct sockaddr_nfc) ||
	    addr->sa_family != AF_NFC) {
		pr_err("Invalid socket\n");
		return -EINVAL;
	}

	if (addr->service_name_len == 0 && addr->dsap == 0) {
		pr_err("Missing service name or dsap\n");
		return -EINVAL;
	}

	pr_debug("addr dev_idx=%u target_idx=%u protocol=%u\n", addr->dev_idx,
		 addr->target_idx, addr->nfc_protocol);

	lock_sock(sk);

	if (sk->sk_state == LLCP_CONNECTED) {
		ret = -EISCONN;
		goto error;
	}

	dev = nfc_get_device(addr->dev_idx);
	if (dev == NULL) {
		ret = -ENODEV;
		goto error;
	}

	local = nfc_llcp_find_local(dev);
	if (local == NULL) {
		ret = -ENODEV;
		goto put_dev;
	}

	device_lock(&dev->dev);
	if (dev->dep_link_up == false) {
		ret = -ENOLINK;
		device_unlock(&dev->dev);
		goto put_dev;
	}
	device_unlock(&dev->dev);

	if (local->rf_mode == NFC_RF_INITIATOR &&
	    addr->target_idx != local->target_idx) {
		ret = -ENOLINK;
		goto put_dev;
	}

	llcp_sock->dev = dev;
	llcp_sock->local = local;
	llcp_sock->ssap = nfc_llcp_get_local_ssap(local);
	if (llcp_sock->ssap == LLCP_SAP_MAX) {
		ret = -ENOMEM;
		goto put_dev;
	}
	if (addr->service_name_len == 0)
		llcp_sock->dsap = addr->dsap;
	else
		llcp_sock->dsap = LLCP_SAP_SDP;
	llcp_sock->nfc_protocol = addr->nfc_protocol;
	llcp_sock->service_name_len = min_t(unsigned int,
					    addr->service_name_len,
					    NFC_LLCP_MAX_SERVICE_NAME);
	llcp_sock->service_name = kmemdup(addr->service_name,
					  llcp_sock->service_name_len,
					  GFP_KERNEL);

	local->sockets[llcp_sock->ssap] = llcp_sock;

	ret = nfc_llcp_send_connect(llcp_sock);
	if (ret)
		goto put_dev;

	sk->sk_state = LLCP_CONNECTED;

	release_sock(sk);
	return 0;

put_dev:
	nfc_put_device(dev);

error:
	release_sock(sk);
	return ret;
}

static int llcp_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
			     struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;
	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
	int ret;

	pr_debug("sock %p sk %p", sock, sk);

	ret = sock_error(sk);
	if (ret)
		return ret;

	if (msg->msg_flags & MSG_OOB)
		return -EOPNOTSUPP;

	lock_sock(sk);

	if (sk->sk_state != LLCP_CONNECTED) {
		release_sock(sk);
		return -ENOTCONN;
	}

	release_sock(sk);

	return nfc_llcp_send_i_frame(llcp_sock, msg, len);
}

static int llcp_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
			     struct msghdr *msg, size_t len, int flags)
{
	int noblock = flags & MSG_DONTWAIT;
	struct sock *sk = sock->sk;
	unsigned int copied, rlen;
	struct sk_buff *skb, *cskb;
	int err = 0;

	pr_debug("%p %zu\n", sk, len);

	lock_sock(sk);

	if (sk->sk_state == LLCP_CLOSED &&
	    skb_queue_empty(&sk->sk_receive_queue)) {
		release_sock(sk);
		return 0;
	}

	release_sock(sk);

	if (flags & (MSG_OOB))
		return -EOPNOTSUPP;

	skb = skb_recv_datagram(sk, flags, noblock, &err);
	if (!skb) {
		pr_err("Recv datagram failed state %d %d %d",
		       sk->sk_state, err, sock_error(sk));

		if (sk->sk_shutdown & RCV_SHUTDOWN)
			return 0;

		return err;
	}

	rlen = skb->len;		/* real length of skb */
	copied = min_t(unsigned int, rlen, len);

	cskb = skb;
	if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
		if (!(flags & MSG_PEEK))
			skb_queue_head(&sk->sk_receive_queue, skb);
		return -EFAULT;
	}

	/* Mark read part of skb as used */
	if (!(flags & MSG_PEEK)) {

		/* SOCK_STREAM: re-queue skb if it contains unreceived data */
		if (sk->sk_type == SOCK_STREAM) {
			skb_pull(skb, copied);
			if (skb->len) {
				skb_queue_head(&sk->sk_receive_queue, skb);
				goto done;
			}
		}

		kfree_skb(skb);
	}

	/* XXX Queue backlogged skbs */

done:
	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
		copied = rlen;

	return copied;
}

static const struct proto_ops llcp_sock_ops = {
	.family         = PF_NFC,
	.owner          = THIS_MODULE,
	.bind           = llcp_sock_bind,
	.connect        = llcp_sock_connect,
	.release        = llcp_sock_release,
	.socketpair     = sock_no_socketpair,
	.accept         = llcp_sock_accept,
	.getname        = llcp_sock_getname,
	.poll           = llcp_sock_poll,
	.ioctl          = sock_no_ioctl,
	.listen         = llcp_sock_listen,
	.shutdown       = sock_no_shutdown,
	.setsockopt     = sock_no_setsockopt,
	.getsockopt     = sock_no_getsockopt,
	.sendmsg        = llcp_sock_sendmsg,
	.recvmsg        = llcp_sock_recvmsg,
	.mmap           = sock_no_mmap,
};

static void llcp_sock_destruct(struct sock *sk)
{
	struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);

	pr_debug("%p\n", sk);

	if (sk->sk_state == LLCP_CONNECTED)
		nfc_put_device(llcp_sock->dev);

	skb_queue_purge(&sk->sk_receive_queue);

	nfc_llcp_sock_free(llcp_sock);

	if (!sock_flag(sk, SOCK_DEAD)) {
		pr_err("Freeing alive NFC LLCP socket %p\n", sk);
		return;
	}
}

struct sock *nfc_llcp_sock_alloc(struct socket *sock, int type, gfp_t gfp)
{
	struct sock *sk;
	struct nfc_llcp_sock *llcp_sock;

	sk = sk_alloc(&init_net, PF_NFC, gfp, &llcp_sock_proto);
	if (!sk)
		return NULL;

	llcp_sock = nfc_llcp_sock(sk);

	sock_init_data(sock, sk);
	sk->sk_state = LLCP_CLOSED;
	sk->sk_protocol = NFC_SOCKPROTO_LLCP;
	sk->sk_type = type;
	sk->sk_destruct = llcp_sock_destruct;

	llcp_sock->ssap = 0;
	llcp_sock->dsap = LLCP_SAP_SDP;
	llcp_sock->send_n = llcp_sock->send_ack_n = 0;
	llcp_sock->recv_n = llcp_sock->recv_ack_n = 0;
	llcp_sock->remote_ready = 1;
	skb_queue_head_init(&llcp_sock->tx_queue);
	skb_queue_head_init(&llcp_sock->tx_pending_queue);
	skb_queue_head_init(&llcp_sock->tx_backlog_queue);
	INIT_LIST_HEAD(&llcp_sock->list);
	INIT_LIST_HEAD(&llcp_sock->accept_queue);

	if (sock != NULL)
		sock->state = SS_UNCONNECTED;

	return sk;
}

void nfc_llcp_sock_free(struct nfc_llcp_sock *sock)
{
	struct nfc_llcp_local *local = sock->local;

	kfree(sock->service_name);

	skb_queue_purge(&sock->tx_queue);
	skb_queue_purge(&sock->tx_pending_queue);
	skb_queue_purge(&sock->tx_backlog_queue);

	list_del_init(&sock->accept_queue);

	if (local != NULL && sock == local->sockets[sock->ssap])
		local->sockets[sock->ssap] = NULL;
	else
		list_del_init(&sock->list);

	sock->parent = NULL;
}

static int llcp_sock_create(struct net *net, struct socket *sock,
			    const struct nfc_protocol *nfc_proto)
{
	struct sock *sk;

	pr_debug("%p\n", sock);

	if (sock->type != SOCK_STREAM && sock->type != SOCK_DGRAM)
		return -ESOCKTNOSUPPORT;

	sock->ops = &llcp_sock_ops;

	sk = nfc_llcp_sock_alloc(sock, sock->type, GFP_ATOMIC);
	if (sk == NULL)
		return -ENOMEM;

	return 0;
}

static const struct nfc_protocol llcp_nfc_proto = {
	.id	  = NFC_SOCKPROTO_LLCP,
	.proto    = &llcp_sock_proto,
	.owner    = THIS_MODULE,
	.create   = llcp_sock_create
};

int __init nfc_llcp_sock_init(void)
{
	return nfc_proto_register(&llcp_nfc_proto);
}

void nfc_llcp_sock_exit(void)
{
	nfc_proto_unregister(&llcp_nfc_proto);
}