1/*
2 * Copyright (C) 2011 Instituto Nokia de Tecnologia
3 *
4 * Authors:
5 *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
6 *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, see <http://www.gnu.org/licenses/>.
20 */
21
22#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
23
24#include <net/tcp_states.h>
25#include <linux/nfc.h>
26#include <linux/export.h>
27
28#include "nfc.h"
29
30static struct nfc_sock_list raw_sk_list = {
31	.lock = __RW_LOCK_UNLOCKED(raw_sk_list.lock)
32};
33
34static void nfc_sock_link(struct nfc_sock_list *l, struct sock *sk)
35{
36	write_lock(&l->lock);
37	sk_add_node(sk, &l->head);
38	write_unlock(&l->lock);
39}
40
41static void nfc_sock_unlink(struct nfc_sock_list *l, struct sock *sk)
42{
43	write_lock(&l->lock);
44	sk_del_node_init(sk);
45	write_unlock(&l->lock);
46}
47
48static void rawsock_write_queue_purge(struct sock *sk)
49{
50	pr_debug("sk=%p\n", sk);
51
52	spin_lock_bh(&sk->sk_write_queue.lock);
53	__skb_queue_purge(&sk->sk_write_queue);
54	nfc_rawsock(sk)->tx_work_scheduled = false;
55	spin_unlock_bh(&sk->sk_write_queue.lock);
56}
57
58static void rawsock_report_error(struct sock *sk, int err)
59{
60	pr_debug("sk=%p err=%d\n", sk, err);
61
62	sk->sk_shutdown = SHUTDOWN_MASK;
63	sk->sk_err = -err;
64	sk->sk_error_report(sk);
65
66	rawsock_write_queue_purge(sk);
67}
68
69static int rawsock_release(struct socket *sock)
70{
71	struct sock *sk = sock->sk;
72
73	pr_debug("sock=%p sk=%p\n", sock, sk);
74
75	if (!sk)
76		return 0;
77
78	if (sock->type == SOCK_RAW)
79		nfc_sock_unlink(&raw_sk_list, sk);
80
81	sock_orphan(sk);
82	sock_put(sk);
83
84	return 0;
85}
86
87static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
88			   int len, int flags)
89{
90	struct sock *sk = sock->sk;
91	struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr;
92	struct nfc_dev *dev;
93	int rc = 0;
94
95	pr_debug("sock=%p sk=%p flags=%d\n", sock, sk, flags);
96
97	if (!addr || len < sizeof(struct sockaddr_nfc) ||
98	    addr->sa_family != AF_NFC)
99		return -EINVAL;
100
101	pr_debug("addr dev_idx=%u target_idx=%u protocol=%u\n",
102		 addr->dev_idx, addr->target_idx, addr->nfc_protocol);
103
104	lock_sock(sk);
105
106	if (sock->state == SS_CONNECTED) {
107		rc = -EISCONN;
108		goto error;
109	}
110
111	dev = nfc_get_device(addr->dev_idx);
112	if (!dev) {
113		rc = -ENODEV;
114		goto error;
115	}
116
117	if (addr->target_idx > dev->target_next_idx - 1 ||
118	    addr->target_idx < dev->target_next_idx - dev->n_targets) {
119		rc = -EINVAL;
120		goto error;
121	}
122
123	rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol);
124	if (rc)
125		goto put_dev;
126
127	nfc_rawsock(sk)->dev = dev;
128	nfc_rawsock(sk)->target_idx = addr->target_idx;
129	sock->state = SS_CONNECTED;
130	sk->sk_state = TCP_ESTABLISHED;
131	sk->sk_state_change(sk);
132
133	release_sock(sk);
134	return 0;
135
136put_dev:
137	nfc_put_device(dev);
138error:
139	release_sock(sk);
140	return rc;
141}
142
143static int rawsock_add_header(struct sk_buff *skb)
144{
145	*skb_push(skb, NFC_HEADER_SIZE) = 0;
146
147	return 0;
148}
149
150static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb,
151					   int err)
152{
153	struct sock *sk = (struct sock *) context;
154
155	BUG_ON(in_irq());
156
157	pr_debug("sk=%p err=%d\n", sk, err);
158
159	if (err)
160		goto error;
161
162	err = rawsock_add_header(skb);
163	if (err)
164		goto error_skb;
165
166	err = sock_queue_rcv_skb(sk, skb);
167	if (err)
168		goto error_skb;
169
170	spin_lock_bh(&sk->sk_write_queue.lock);
171	if (!skb_queue_empty(&sk->sk_write_queue))
172		schedule_work(&nfc_rawsock(sk)->tx_work);
173	else
174		nfc_rawsock(sk)->tx_work_scheduled = false;
175	spin_unlock_bh(&sk->sk_write_queue.lock);
176
177	sock_put(sk);
178	return;
179
180error_skb:
181	kfree_skb(skb);
182
183error:
184	rawsock_report_error(sk, err);
185	sock_put(sk);
186}
187
188static void rawsock_tx_work(struct work_struct *work)
189{
190	struct sock *sk = to_rawsock_sk(work);
191	struct nfc_dev *dev = nfc_rawsock(sk)->dev;
192	u32 target_idx = nfc_rawsock(sk)->target_idx;
193	struct sk_buff *skb;
194	int rc;
195
196	pr_debug("sk=%p target_idx=%u\n", sk, target_idx);
197
198	if (sk->sk_shutdown & SEND_SHUTDOWN) {
199		rawsock_write_queue_purge(sk);
200		return;
201	}
202
203	skb = skb_dequeue(&sk->sk_write_queue);
204
205	sock_hold(sk);
206	rc = nfc_data_exchange(dev, target_idx, skb,
207			       rawsock_data_exchange_complete, sk);
208	if (rc) {
209		rawsock_report_error(sk, rc);
210		sock_put(sk);
211	}
212}
213
214static int rawsock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
215{
216	struct sock *sk = sock->sk;
217	struct nfc_dev *dev = nfc_rawsock(sk)->dev;
218	struct sk_buff *skb;
219	int rc;
220
221	pr_debug("sock=%p sk=%p len=%zu\n", sock, sk, len);
222
223	if (msg->msg_namelen)
224		return -EOPNOTSUPP;
225
226	if (sock->state != SS_CONNECTED)
227		return -ENOTCONN;
228
229	skb = nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc);
230	if (skb == NULL)
231		return rc;
232
233	rc = memcpy_from_msg(skb_put(skb, len), msg, len);
234	if (rc < 0) {
235		kfree_skb(skb);
236		return rc;
237	}
238
239	spin_lock_bh(&sk->sk_write_queue.lock);
240	__skb_queue_tail(&sk->sk_write_queue, skb);
241	if (!nfc_rawsock(sk)->tx_work_scheduled) {
242		schedule_work(&nfc_rawsock(sk)->tx_work);
243		nfc_rawsock(sk)->tx_work_scheduled = true;
244	}
245	spin_unlock_bh(&sk->sk_write_queue.lock);
246
247	return len;
248}
249
250static int rawsock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
251			   int flags)
252{
253	int noblock = flags & MSG_DONTWAIT;
254	struct sock *sk = sock->sk;
255	struct sk_buff *skb;
256	int copied;
257	int rc;
258
259	pr_debug("sock=%p sk=%p len=%zu flags=%d\n", sock, sk, len, flags);
260
261	skb = skb_recv_datagram(sk, flags, noblock, &rc);
262	if (!skb)
263		return rc;
264
265	copied = skb->len;
266	if (len < copied) {
267		msg->msg_flags |= MSG_TRUNC;
268		copied = len;
269	}
270
271	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
272
273	skb_free_datagram(sk, skb);
274
275	return rc ? : copied;
276}
277
278static const struct proto_ops rawsock_ops = {
279	.family         = PF_NFC,
280	.owner          = THIS_MODULE,
281	.release        = rawsock_release,
282	.bind           = sock_no_bind,
283	.connect        = rawsock_connect,
284	.socketpair     = sock_no_socketpair,
285	.accept         = sock_no_accept,
286	.getname        = sock_no_getname,
287	.poll           = datagram_poll,
288	.ioctl          = sock_no_ioctl,
289	.listen         = sock_no_listen,
290	.shutdown       = sock_no_shutdown,
291	.setsockopt     = sock_no_setsockopt,
292	.getsockopt     = sock_no_getsockopt,
293	.sendmsg        = rawsock_sendmsg,
294	.recvmsg        = rawsock_recvmsg,
295	.mmap           = sock_no_mmap,
296};
297
298static const struct proto_ops rawsock_raw_ops = {
299	.family         = PF_NFC,
300	.owner          = THIS_MODULE,
301	.release        = rawsock_release,
302	.bind           = sock_no_bind,
303	.connect        = sock_no_connect,
304	.socketpair     = sock_no_socketpair,
305	.accept         = sock_no_accept,
306	.getname        = sock_no_getname,
307	.poll           = datagram_poll,
308	.ioctl          = sock_no_ioctl,
309	.listen         = sock_no_listen,
310	.shutdown       = sock_no_shutdown,
311	.setsockopt     = sock_no_setsockopt,
312	.getsockopt     = sock_no_getsockopt,
313	.sendmsg        = sock_no_sendmsg,
314	.recvmsg        = rawsock_recvmsg,
315	.mmap           = sock_no_mmap,
316};
317
318static void rawsock_destruct(struct sock *sk)
319{
320	pr_debug("sk=%p\n", sk);
321
322	if (sk->sk_state == TCP_ESTABLISHED) {
323		nfc_deactivate_target(nfc_rawsock(sk)->dev,
324				      nfc_rawsock(sk)->target_idx);
325		nfc_put_device(nfc_rawsock(sk)->dev);
326	}
327
328	skb_queue_purge(&sk->sk_receive_queue);
329
330	if (!sock_flag(sk, SOCK_DEAD)) {
331		pr_err("Freeing alive NFC raw socket %p\n", sk);
332		return;
333	}
334}
335
336static int rawsock_create(struct net *net, struct socket *sock,
337			  const struct nfc_protocol *nfc_proto)
338{
339	struct sock *sk;
340
341	pr_debug("sock=%p\n", sock);
342
343	if ((sock->type != SOCK_SEQPACKET) && (sock->type != SOCK_RAW))
344		return -ESOCKTNOSUPPORT;
345
346	if (sock->type == SOCK_RAW)
347		sock->ops = &rawsock_raw_ops;
348	else
349		sock->ops = &rawsock_ops;
350
351	sk = sk_alloc(net, PF_NFC, GFP_ATOMIC, nfc_proto->proto);
352	if (!sk)
353		return -ENOMEM;
354
355	sock_init_data(sock, sk);
356	sk->sk_protocol = nfc_proto->id;
357	sk->sk_destruct = rawsock_destruct;
358	sock->state = SS_UNCONNECTED;
359	if (sock->type == SOCK_RAW)
360		nfc_sock_link(&raw_sk_list, sk);
361	else {
362		INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
363		nfc_rawsock(sk)->tx_work_scheduled = false;
364	}
365
366	return 0;
367}
368
369void nfc_send_to_raw_sock(struct nfc_dev *dev, struct sk_buff *skb,
370			  u8 payload_type, u8 direction)
371{
372	struct sk_buff *skb_copy = NULL, *nskb;
373	struct sock *sk;
374	u8 *data;
375
376	read_lock(&raw_sk_list.lock);
377
378	sk_for_each(sk, &raw_sk_list.head) {
379		if (!skb_copy) {
380			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
381						      GFP_ATOMIC, true);
382			if (!skb_copy)
383				continue;
384
385			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
386
387			data[0] = dev ? dev->idx : 0xFF;
388			data[1] = direction & 0x01;
389			data[1] |= (payload_type << 1);
390		}
391
392		nskb = skb_clone(skb_copy, GFP_ATOMIC);
393		if (!nskb)
394			continue;
395
396		if (sock_queue_rcv_skb(sk, nskb))
397			kfree_skb(nskb);
398	}
399
400	read_unlock(&raw_sk_list.lock);
401
402	kfree_skb(skb_copy);
403}
404EXPORT_SYMBOL(nfc_send_to_raw_sock);
405
406static struct proto rawsock_proto = {
407	.name     = "NFC_RAW",
408	.owner    = THIS_MODULE,
409	.obj_size = sizeof(struct nfc_rawsock),
410};
411
412static const struct nfc_protocol rawsock_nfc_proto = {
413	.id	  = NFC_SOCKPROTO_RAW,
414	.proto    = &rawsock_proto,
415	.owner    = THIS_MODULE,
416	.create   = rawsock_create
417};
418
419int __init rawsock_init(void)
420{
421	int rc;
422
423	rc = nfc_proto_register(&rawsock_nfc_proto);
424
425	return rc;
426}
427
428void rawsock_exit(void)
429{
430	nfc_proto_unregister(&rawsock_nfc_proto);
431}
432