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, write to the
20 * Free Software Foundation, Inc.,
21 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 */
23
24#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
25
26#include <net/tcp_states.h>
27#include <linux/nfc.h>
28#include <linux/export.h>
29
30#include "nfc.h"
31
32static void rawsock_write_queue_purge(struct sock *sk)
33{
34	pr_debug("sk=%p\n", sk);
35
36	spin_lock_bh(&sk->sk_write_queue.lock);
37	__skb_queue_purge(&sk->sk_write_queue);
38	nfc_rawsock(sk)->tx_work_scheduled = false;
39	spin_unlock_bh(&sk->sk_write_queue.lock);
40}
41
42static void rawsock_report_error(struct sock *sk, int err)
43{
44	pr_debug("sk=%p err=%d\n", sk, err);
45
46	sk->sk_shutdown = SHUTDOWN_MASK;
47	sk->sk_err = -err;
48	sk->sk_error_report(sk);
49
50	rawsock_write_queue_purge(sk);
51}
52
53static int rawsock_release(struct socket *sock)
54{
55	struct sock *sk = sock->sk;
56
57	pr_debug("sock=%p sk=%p\n", sock, sk);
58
59	if (!sk)
60		return 0;
61
62	sock_orphan(sk);
63	sock_put(sk);
64
65	return 0;
66}
67
68static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
69			   int len, int flags)
70{
71	struct sock *sk = sock->sk;
72	struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr;
73	struct nfc_dev *dev;
74	int rc = 0;
75
76	pr_debug("sock=%p sk=%p flags=%d\n", sock, sk, flags);
77
78	if (!addr || len < sizeof(struct sockaddr_nfc) ||
79	    addr->sa_family != AF_NFC)
80		return -EINVAL;
81
82	pr_debug("addr dev_idx=%u target_idx=%u protocol=%u\n",
83		 addr->dev_idx, addr->target_idx, addr->nfc_protocol);
84
85	lock_sock(sk);
86
87	if (sock->state == SS_CONNECTED) {
88		rc = -EISCONN;
89		goto error;
90	}
91
92	dev = nfc_get_device(addr->dev_idx);
93	if (!dev) {
94		rc = -ENODEV;
95		goto error;
96	}
97
98	if (addr->target_idx > dev->target_next_idx - 1 ||
99	    addr->target_idx < dev->target_next_idx - dev->n_targets) {
100		rc = -EINVAL;
101		goto error;
102	}
103
104	rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol);
105	if (rc)
106		goto put_dev;
107
108	nfc_rawsock(sk)->dev = dev;
109	nfc_rawsock(sk)->target_idx = addr->target_idx;
110	sock->state = SS_CONNECTED;
111	sk->sk_state = TCP_ESTABLISHED;
112	sk->sk_state_change(sk);
113
114	release_sock(sk);
115	return 0;
116
117put_dev:
118	nfc_put_device(dev);
119error:
120	release_sock(sk);
121	return rc;
122}
123
124static int rawsock_add_header(struct sk_buff *skb)
125{
126	*skb_push(skb, NFC_HEADER_SIZE) = 0;
127
128	return 0;
129}
130
131static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb,
132					   int err)
133{
134	struct sock *sk = (struct sock *) context;
135
136	BUG_ON(in_irq());
137
138	pr_debug("sk=%p err=%d\n", sk, err);
139
140	if (err)
141		goto error;
142
143	err = rawsock_add_header(skb);
144	if (err)
145		goto error;
146
147	err = sock_queue_rcv_skb(sk, skb);
148	if (err)
149		goto error;
150
151	spin_lock_bh(&sk->sk_write_queue.lock);
152	if (!skb_queue_empty(&sk->sk_write_queue))
153		schedule_work(&nfc_rawsock(sk)->tx_work);
154	else
155		nfc_rawsock(sk)->tx_work_scheduled = false;
156	spin_unlock_bh(&sk->sk_write_queue.lock);
157
158	sock_put(sk);
159	return;
160
161error:
162	rawsock_report_error(sk, err);
163	sock_put(sk);
164}
165
166static void rawsock_tx_work(struct work_struct *work)
167{
168	struct sock *sk = to_rawsock_sk(work);
169	struct nfc_dev *dev = nfc_rawsock(sk)->dev;
170	u32 target_idx = nfc_rawsock(sk)->target_idx;
171	struct sk_buff *skb;
172	int rc;
173
174	pr_debug("sk=%p target_idx=%u\n", sk, target_idx);
175
176	if (sk->sk_shutdown & SEND_SHUTDOWN) {
177		rawsock_write_queue_purge(sk);
178		return;
179	}
180
181	skb = skb_dequeue(&sk->sk_write_queue);
182
183	sock_hold(sk);
184	rc = nfc_data_exchange(dev, target_idx, skb,
185			       rawsock_data_exchange_complete, sk);
186	if (rc) {
187		rawsock_report_error(sk, rc);
188		sock_put(sk);
189	}
190}
191
192static int rawsock_sendmsg(struct kiocb *iocb, struct socket *sock,
193			   struct msghdr *msg, size_t len)
194{
195	struct sock *sk = sock->sk;
196	struct nfc_dev *dev = nfc_rawsock(sk)->dev;
197	struct sk_buff *skb;
198	int rc;
199
200	pr_debug("sock=%p sk=%p len=%zu\n", sock, sk, len);
201
202	if (msg->msg_namelen)
203		return -EOPNOTSUPP;
204
205	if (sock->state != SS_CONNECTED)
206		return -ENOTCONN;
207
208	skb = nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc);
209	if (skb == NULL)
210		return rc;
211
212	rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
213	if (rc < 0) {
214		kfree_skb(skb);
215		return rc;
216	}
217
218	spin_lock_bh(&sk->sk_write_queue.lock);
219	__skb_queue_tail(&sk->sk_write_queue, skb);
220	if (!nfc_rawsock(sk)->tx_work_scheduled) {
221		schedule_work(&nfc_rawsock(sk)->tx_work);
222		nfc_rawsock(sk)->tx_work_scheduled = true;
223	}
224	spin_unlock_bh(&sk->sk_write_queue.lock);
225
226	return len;
227}
228
229static int rawsock_recvmsg(struct kiocb *iocb, struct socket *sock,
230			   struct msghdr *msg, size_t len, int flags)
231{
232	int noblock = flags & MSG_DONTWAIT;
233	struct sock *sk = sock->sk;
234	struct sk_buff *skb;
235	int copied;
236	int rc;
237
238	pr_debug("sock=%p sk=%p len=%zu flags=%d\n", sock, sk, len, flags);
239
240	skb = skb_recv_datagram(sk, flags, noblock, &rc);
241	if (!skb)
242		return rc;
243
244	msg->msg_namelen = 0;
245
246	copied = skb->len;
247	if (len < copied) {
248		msg->msg_flags |= MSG_TRUNC;
249		copied = len;
250	}
251
252	rc = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
253
254	skb_free_datagram(sk, skb);
255
256	return rc ? : copied;
257}
258
259static const struct proto_ops rawsock_ops = {
260	.family         = PF_NFC,
261	.owner          = THIS_MODULE,
262	.release        = rawsock_release,
263	.bind           = sock_no_bind,
264	.connect        = rawsock_connect,
265	.socketpair     = sock_no_socketpair,
266	.accept         = sock_no_accept,
267	.getname        = sock_no_getname,
268	.poll           = datagram_poll,
269	.ioctl          = sock_no_ioctl,
270	.listen         = sock_no_listen,
271	.shutdown       = sock_no_shutdown,
272	.setsockopt     = sock_no_setsockopt,
273	.getsockopt     = sock_no_getsockopt,
274	.sendmsg        = rawsock_sendmsg,
275	.recvmsg        = rawsock_recvmsg,
276	.mmap           = sock_no_mmap,
277};
278
279static void rawsock_destruct(struct sock *sk)
280{
281	pr_debug("sk=%p\n", sk);
282
283	if (sk->sk_state == TCP_ESTABLISHED) {
284		nfc_deactivate_target(nfc_rawsock(sk)->dev,
285				      nfc_rawsock(sk)->target_idx);
286		nfc_put_device(nfc_rawsock(sk)->dev);
287	}
288
289	skb_queue_purge(&sk->sk_receive_queue);
290
291	if (!sock_flag(sk, SOCK_DEAD)) {
292		pr_err("Freeing alive NFC raw socket %p\n", sk);
293		return;
294	}
295}
296
297static int rawsock_create(struct net *net, struct socket *sock,
298			  const struct nfc_protocol *nfc_proto)
299{
300	struct sock *sk;
301
302	pr_debug("sock=%p\n", sock);
303
304	if (sock->type != SOCK_SEQPACKET)
305		return -ESOCKTNOSUPPORT;
306
307	sock->ops = &rawsock_ops;
308
309	sk = sk_alloc(net, PF_NFC, GFP_ATOMIC, nfc_proto->proto);
310	if (!sk)
311		return -ENOMEM;
312
313	sock_init_data(sock, sk);
314	sk->sk_protocol = nfc_proto->id;
315	sk->sk_destruct = rawsock_destruct;
316	sock->state = SS_UNCONNECTED;
317
318	INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
319	nfc_rawsock(sk)->tx_work_scheduled = false;
320
321	return 0;
322}
323
324static struct proto rawsock_proto = {
325	.name     = "NFC_RAW",
326	.owner    = THIS_MODULE,
327	.obj_size = sizeof(struct nfc_rawsock),
328};
329
330static const struct nfc_protocol rawsock_nfc_proto = {
331	.id	  = NFC_SOCKPROTO_RAW,
332	.proto    = &rawsock_proto,
333	.owner    = THIS_MODULE,
334	.create   = rawsock_create
335};
336
337int __init rawsock_init(void)
338{
339	int rc;
340
341	rc = nfc_proto_register(&rawsock_nfc_proto);
342
343	return rc;
344}
345
346void rawsock_exit(void)
347{
348	nfc_proto_unregister(&rawsock_nfc_proto);
349}
350