summaryrefslogtreecommitdiffstats
path: root/kernel/net/nfc/rawsock.c
blob: 82b4e8024778019b80f6b59ba9a4242d015d4b2f (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
/*
 * Copyright (C) 2011 Instituto Nokia de Tecnologia
 *
 * Authors:
 *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
 *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

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

#include <net/tcp_states.h>
#include <linux/nfc.h>
#include <linux/export.h>

#include "nfc.h"

static struct nfc_sock_list raw_sk_list = {
	.lock = __RW_LOCK_UNLOCKED(raw_sk_list.lock)
};

static void nfc_sock_link(struct nfc_sock_list *l, struct sock *sk)
{
	write_lock(&l->lock);
	sk_add_node(sk, &l->head);
	write_unlock(&l->lock);
}

static void nfc_sock_unlink(struct nfc_sock_list *l, struct sock *sk)
{
	write_lock(&l->lock);
	sk_del_node_init(sk);
	write_unlock(&l->lock);
}

static void rawsock_write_queue_purge(struct sock *sk)
{
	pr_debug("sk=%p\n", sk);

	spin_lock_bh(&sk->sk_write_queue.lock);
	__skb_queue_purge(&sk->sk_write_queue);
	nfc_rawsock(sk)->tx_work_scheduled = false;
	spin_unlock_bh(&sk->sk_write_queue.lock);
}

static void rawsock_report_error(struct sock *sk, int err)
{
	pr_debug("sk=%p err=%d\n", sk, err);

	sk->sk_shutdown = SHUTDOWN_MASK;
	sk->sk_err = -err;
	sk->sk_error_report(sk);

	rawsock_write_queue_purge(sk);
}

static int rawsock_release(struct socket *sock)
{
	struct sock *sk = sock->sk;

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

	if (!sk)
		return 0;

	if (sock->type == SOCK_RAW)
		nfc_sock_unlink(&raw_sk_list, sk);

	sock_orphan(sk);
	sock_put(sk);

	return 0;
}

static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
			   int len, int flags)
{
	struct sock *sk = sock->sk;
	struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr;
	struct nfc_dev *dev;
	int rc = 0;

	pr_debug("sock=%p sk=%p flags=%d\n", sock, sk, flags);

	if (!addr || len < sizeof(struct sockaddr_nfc) ||
	    addr->sa_family != AF_NFC)
		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 (sock->state == SS_CONNECTED) {
		rc = -EISCONN;
		goto error;
	}

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

	if (addr->target_idx > dev->target_next_idx - 1 ||
	    addr->target_idx < dev->target_next_idx - dev->n_targets) {
		rc = -EINVAL;
		goto error;
	}

	rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol);
	if (rc)
		goto put_dev;

	nfc_rawsock(sk)->dev = dev;
	nfc_rawsock(sk)->target_idx = addr->target_idx;
	sock->state = SS_CONNECTED;
	sk->sk_state = TCP_ESTABLISHED;
	sk->sk_state_change(sk);

	release_sock(sk);
	return 0;

put_dev:
	nfc_put_device(dev);
error:
	release_sock(sk);
	return rc;
}

static int rawsock_add_header(struct sk_buff *skb)
{
	*skb_push(skb, NFC_HEADER_SIZE) = 0;

	return 0;
}

static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb,
					   int err)
{
	struct sock *sk = (struct sock *) context;

	BUG_ON(in_irq());

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

	if (err)
		goto error;

	err = rawsock_add_header(skb);
	if (err)
		goto error_skb;

	err = sock_queue_rcv_skb(sk, skb);
	if (err)
		goto error_skb;

	spin_lock_bh(&sk->sk_write_queue.lock);
	if (!skb_queue_empty(&sk->sk_write_queue))
		schedule_work(&nfc_rawsock(sk)->tx_work);
	else
		nfc_rawsock(sk)->tx_work_scheduled = false;
	spin_unlock_bh(&sk->sk_write_queue.lock);

	sock_put(sk);
	return;

error_skb:
	kfree_skb(skb);

error:
	rawsock_report_error(sk, err);
	sock_put(sk);
}

static void rawsock_tx_work(struct work_struct *work)
{
	struct sock *sk = to_rawsock_sk(work);
	struct nfc_dev *dev = nfc_rawsock(sk)->dev;
	u32 target_idx = nfc_rawsock(sk)->target_idx;
	struct sk_buff *skb;
	int rc;

	pr_debug("sk=%p target_idx=%u\n", sk, target_idx);

	if (sk->sk_shutdown & SEND_SHUTDOWN) {
		rawsock_write_queue_purge(sk);
		return;
	}

	skb = skb_dequeue(&sk->sk_write_queue);

	sock_hold(sk);
	rc = nfc_data_exchange(dev, target_idx, skb,
			       rawsock_data_exchange_complete, sk);
	if (rc) {
		rawsock_report_error(sk, rc);
		sock_put(sk);
	}
}

static int rawsock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;
	struct nfc_dev *dev = nfc_rawsock(sk)->dev;
	struct sk_buff *skb;
	int rc;

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

	if (msg->msg_namelen)
		return -EOPNOTSUPP;

	if (sock->state != SS_CONNECTED)
		return -ENOTCONN;

	skb = nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc);
	if (skb == NULL)
		return rc;

	rc = memcpy_from_msg(skb_put(skb, len), msg, len);
	if (rc < 0) {
		kfree_skb(skb);
		return rc;
	}

	spin_lock_bh(&sk->sk_write_queue.lock);
	__skb_queue_tail(&sk->sk_write_queue, skb);
	if (!nfc_rawsock(sk)->tx_work_scheduled) {
		schedule_work(&nfc_rawsock(sk)->tx_work);
		nfc_rawsock(sk)->tx_work_scheduled = true;
	}
	spin_unlock_bh(&sk->sk_write_queue.lock);

	return len;
}

static int rawsock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
			   int flags)
{
	int noblock = flags & MSG_DONTWAIT;
	struct sock *sk = sock->sk;
	struct sk_buff *skb;
	int copied;
	int rc;

	pr_debug("sock=%p sk=%p len=%zu flags=%d\n", sock, sk, len, flags);

	skb = skb_recv_datagram(sk, flags, noblock, &rc);
	if (!skb)
		return rc;

	copied = skb->len;
	if (len < copied) {
		msg->msg_flags |= MSG_TRUNC;
		copied = len;
	}

	rc = skb_copy_datagram_msg(skb, 0, msg, copied);

	skb_free_datagram(sk, skb);

	return rc ? : copied;
}

static const struct proto_ops rawsock_ops = {
	.family         = PF_NFC,
	.owner          = THIS_MODULE,
	.release        = rawsock_release,
	.bind           = sock_no_bind,
	.connect        = rawsock_connect,
	.socketpair     = sock_no_socketpair,
	.accept         = sock_no_accept,
	.getname        = sock_no_getname,
	.poll           = datagram_poll,
	.ioctl          = sock_no_ioctl,
	.listen         = sock_no_listen,
	.shutdown       = sock_no_shutdown,
	.setsockopt     = sock_no_setsockopt,
	.getsockopt     = sock_no_getsockopt,
	.sendmsg        = rawsock_sendmsg,
	.recvmsg        = rawsock_recvmsg,
	.mmap           = sock_no_mmap,
};

static const struct proto_ops rawsock_raw_ops = {
	.family         = PF_NFC,
	.owner          = THIS_MODULE,
	.release        = rawsock_release,
	.bind           = sock_no_bind,
	.connect        = sock_no_connect,
	.socketpair     = sock_no_socketpair,
	.accept         = sock_no_accept,
	.getname        = sock_no_getname,
	.poll           = datagram_poll,
	.ioctl          = sock_no_ioctl,
	.listen         = sock_no_listen,
	.shutdown       = sock_no_shutdown,
	.setsockopt     = sock_no_setsockopt,
	.getsockopt     = sock_no_getsockopt,
	.sendmsg        = sock_no_sendmsg,
	.recvmsg        = rawsock_recvmsg,
	.mmap           = sock_no_mmap,
};

static void rawsock_destruct(struct sock *sk)
{
	pr_debug("sk=%p\n", sk);

	if (sk->sk_state == TCP_ESTABLISHED) {
		nfc_deactivate_target(nfc_rawsock(sk)->dev,
				      nfc_rawsock(sk)->target_idx);
		nfc_put_device(nfc_rawsock(sk)->dev);
	}

	skb_queue_purge(&sk->sk_receive_queue);

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

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

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

	if ((sock->type != SOCK_SEQPACKET) && (sock->type != SOCK_RAW))
		return -ESOCKTNOSUPPORT;

	if (sock->type == SOCK_RAW)
		sock->ops = &rawsock_raw_ops;
	else
		sock->ops = &rawsock_ops;

	sk = sk_alloc(net, PF_NFC, GFP_ATOMIC, nfc_proto->proto);
	if (!sk)
		return -ENOMEM;

	sock_init_data(sock, sk);
	sk->sk_protocol = nfc_proto->id;
	sk->sk_destruct = rawsock_destruct;
	sock->state = SS_UNCONNECTED;
	if (sock->type == SOCK_RAW)
		nfc_sock_link(&raw_sk_list, sk);
	else {
		INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
		nfc_rawsock(sk)->tx_work_scheduled = false;
	}

	return 0;
}

void nfc_send_to_raw_sock(struct nfc_dev *dev, struct sk_buff *skb,
			  u8 payload_type, u8 direction)
{
	struct sk_buff *skb_copy = NULL, *nskb;
	struct sock *sk;
	u8 *data;

	read_lock(&raw_sk_list.lock);

	sk_for_each(sk, &raw_sk_list.head) {
		if (!skb_copy) {
			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
						      GFP_ATOMIC, true);
			if (!skb_copy)
				continue;

			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);

			data[0] = dev ? dev->idx : 0xFF;
			data[1] = direction & 0x01;
			data[1] |= (payload_type << 1);
		}

		nskb = skb_clone(skb_copy, GFP_ATOMIC);
		if (!nskb)
			continue;

		if (sock_queue_rcv_skb(sk, nskb))
			kfree_skb(nskb);
	}

	read_unlock(&raw_sk_list.lock);

	kfree_skb(skb_copy);
}
EXPORT_SYMBOL(nfc_send_to_raw_sock);

static struct proto rawsock_proto = {
	.name     = "NFC_RAW",
	.owner    = THIS_MODULE,
	.obj_size = sizeof(struct nfc_rawsock),
};

static const struct nfc_protocol rawsock_nfc_proto = {
	.id	  = NFC_SOCKPROTO_RAW,
	.proto    = &rawsock_proto,
	.owner    = THIS_MODULE,
	.create   = rawsock_create
};

int __init rawsock_init(void)
{
	int rc;

	rc = nfc_proto_register(&rawsock_nfc_proto);

	return rc;
}

void rawsock_exit(void)
{
	nfc_proto_unregister(&rawsock_nfc_proto);
}