xref: /linux/net/nfc/rawsock.c (revision a508da6cc0093171833efb8376b00473f24221b9)
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 
32 static 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 
42 static 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 
53 static int rawsock_release(struct socket *sock)
54 {
55 	struct sock *sk = sock->sk;
56 
57 	pr_debug("sock=%p\n", sock);
58 
59 	sock_orphan(sk);
60 	sock_put(sk);
61 
62 	return 0;
63 }
64 
65 static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
66 			   int len, int flags)
67 {
68 	struct sock *sk = sock->sk;
69 	struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr;
70 	struct nfc_dev *dev;
71 	int rc = 0;
72 
73 	pr_debug("sock=%p sk=%p flags=%d\n", sock, sk, flags);
74 
75 	if (!addr || len < sizeof(struct sockaddr_nfc) ||
76 	    addr->sa_family != AF_NFC)
77 		return -EINVAL;
78 
79 	pr_debug("addr dev_idx=%u target_idx=%u protocol=%u\n",
80 		 addr->dev_idx, addr->target_idx, addr->nfc_protocol);
81 
82 	lock_sock(sk);
83 
84 	if (sock->state == SS_CONNECTED) {
85 		rc = -EISCONN;
86 		goto error;
87 	}
88 
89 	dev = nfc_get_device(addr->dev_idx);
90 	if (!dev) {
91 		rc = -ENODEV;
92 		goto error;
93 	}
94 
95 	if (addr->target_idx > dev->target_next_idx - 1 ||
96 	    addr->target_idx < dev->target_next_idx - dev->n_targets) {
97 		rc = -EINVAL;
98 		goto error;
99 	}
100 
101 	rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol);
102 	if (rc)
103 		goto put_dev;
104 
105 	nfc_rawsock(sk)->dev = dev;
106 	nfc_rawsock(sk)->target_idx = addr->target_idx;
107 	sock->state = SS_CONNECTED;
108 	sk->sk_state = TCP_ESTABLISHED;
109 	sk->sk_state_change(sk);
110 
111 	release_sock(sk);
112 	return 0;
113 
114 put_dev:
115 	nfc_put_device(dev);
116 error:
117 	release_sock(sk);
118 	return rc;
119 }
120 
121 static int rawsock_add_header(struct sk_buff *skb)
122 {
123 	*skb_push(skb, NFC_HEADER_SIZE) = 0;
124 
125 	return 0;
126 }
127 
128 static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb,
129 					   int err)
130 {
131 	struct sock *sk = (struct sock *) context;
132 
133 	BUG_ON(in_irq());
134 
135 	pr_debug("sk=%p err=%d\n", sk, err);
136 
137 	if (err)
138 		goto error;
139 
140 	err = rawsock_add_header(skb);
141 	if (err)
142 		goto error;
143 
144 	err = sock_queue_rcv_skb(sk, skb);
145 	if (err)
146 		goto error;
147 
148 	spin_lock_bh(&sk->sk_write_queue.lock);
149 	if (!skb_queue_empty(&sk->sk_write_queue))
150 		schedule_work(&nfc_rawsock(sk)->tx_work);
151 	else
152 		nfc_rawsock(sk)->tx_work_scheduled = false;
153 	spin_unlock_bh(&sk->sk_write_queue.lock);
154 
155 	sock_put(sk);
156 	return;
157 
158 error:
159 	rawsock_report_error(sk, err);
160 	sock_put(sk);
161 }
162 
163 static void rawsock_tx_work(struct work_struct *work)
164 {
165 	struct sock *sk = to_rawsock_sk(work);
166 	struct nfc_dev *dev = nfc_rawsock(sk)->dev;
167 	u32 target_idx = nfc_rawsock(sk)->target_idx;
168 	struct sk_buff *skb;
169 	int rc;
170 
171 	pr_debug("sk=%p target_idx=%u\n", sk, target_idx);
172 
173 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
174 		rawsock_write_queue_purge(sk);
175 		return;
176 	}
177 
178 	skb = skb_dequeue(&sk->sk_write_queue);
179 
180 	sock_hold(sk);
181 	rc = nfc_data_exchange(dev, target_idx, skb,
182 			       rawsock_data_exchange_complete, sk);
183 	if (rc) {
184 		rawsock_report_error(sk, rc);
185 		sock_put(sk);
186 	}
187 }
188 
189 static int rawsock_sendmsg(struct kiocb *iocb, struct socket *sock,
190 			   struct msghdr *msg, size_t len)
191 {
192 	struct sock *sk = sock->sk;
193 	struct nfc_dev *dev = nfc_rawsock(sk)->dev;
194 	struct sk_buff *skb;
195 	int rc;
196 
197 	pr_debug("sock=%p sk=%p len=%zu\n", sock, sk, len);
198 
199 	if (msg->msg_namelen)
200 		return -EOPNOTSUPP;
201 
202 	if (sock->state != SS_CONNECTED)
203 		return -ENOTCONN;
204 
205 	skb = nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc);
206 	if (skb == NULL)
207 		return rc;
208 
209 	rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
210 	if (rc < 0) {
211 		kfree_skb(skb);
212 		return rc;
213 	}
214 
215 	spin_lock_bh(&sk->sk_write_queue.lock);
216 	__skb_queue_tail(&sk->sk_write_queue, skb);
217 	if (!nfc_rawsock(sk)->tx_work_scheduled) {
218 		schedule_work(&nfc_rawsock(sk)->tx_work);
219 		nfc_rawsock(sk)->tx_work_scheduled = true;
220 	}
221 	spin_unlock_bh(&sk->sk_write_queue.lock);
222 
223 	return len;
224 }
225 
226 static int rawsock_recvmsg(struct kiocb *iocb, struct socket *sock,
227 			   struct msghdr *msg, size_t len, int flags)
228 {
229 	int noblock = flags & MSG_DONTWAIT;
230 	struct sock *sk = sock->sk;
231 	struct sk_buff *skb;
232 	int copied;
233 	int rc;
234 
235 	pr_debug("sock=%p sk=%p len=%zu flags=%d\n", sock, sk, len, flags);
236 
237 	skb = skb_recv_datagram(sk, flags, noblock, &rc);
238 	if (!skb)
239 		return rc;
240 
241 	msg->msg_namelen = 0;
242 
243 	copied = skb->len;
244 	if (len < copied) {
245 		msg->msg_flags |= MSG_TRUNC;
246 		copied = len;
247 	}
248 
249 	rc = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
250 
251 	skb_free_datagram(sk, skb);
252 
253 	return rc ? : copied;
254 }
255 
256 
257 static const struct proto_ops rawsock_ops = {
258 	.family         = PF_NFC,
259 	.owner          = THIS_MODULE,
260 	.release        = rawsock_release,
261 	.bind           = sock_no_bind,
262 	.connect        = rawsock_connect,
263 	.socketpair     = sock_no_socketpair,
264 	.accept         = sock_no_accept,
265 	.getname        = sock_no_getname,
266 	.poll           = datagram_poll,
267 	.ioctl          = sock_no_ioctl,
268 	.listen         = sock_no_listen,
269 	.shutdown       = sock_no_shutdown,
270 	.setsockopt     = sock_no_setsockopt,
271 	.getsockopt     = sock_no_getsockopt,
272 	.sendmsg        = rawsock_sendmsg,
273 	.recvmsg        = rawsock_recvmsg,
274 	.mmap           = sock_no_mmap,
275 };
276 
277 static void rawsock_destruct(struct sock *sk)
278 {
279 	pr_debug("sk=%p\n", sk);
280 
281 	if (sk->sk_state == TCP_ESTABLISHED) {
282 		nfc_deactivate_target(nfc_rawsock(sk)->dev,
283 				      nfc_rawsock(sk)->target_idx);
284 		nfc_put_device(nfc_rawsock(sk)->dev);
285 	}
286 
287 	skb_queue_purge(&sk->sk_receive_queue);
288 
289 	if (!sock_flag(sk, SOCK_DEAD)) {
290 		pr_err("Freeing alive NFC raw socket %p\n", sk);
291 		return;
292 	}
293 }
294 
295 static int rawsock_create(struct net *net, struct socket *sock,
296 			  const struct nfc_protocol *nfc_proto)
297 {
298 	struct sock *sk;
299 
300 	pr_debug("sock=%p\n", sock);
301 
302 	if (sock->type != SOCK_SEQPACKET)
303 		return -ESOCKTNOSUPPORT;
304 
305 	sock->ops = &rawsock_ops;
306 
307 	sk = sk_alloc(net, PF_NFC, GFP_ATOMIC, nfc_proto->proto);
308 	if (!sk)
309 		return -ENOMEM;
310 
311 	sock_init_data(sock, sk);
312 	sk->sk_protocol = nfc_proto->id;
313 	sk->sk_destruct = rawsock_destruct;
314 	sock->state = SS_UNCONNECTED;
315 
316 	INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
317 	nfc_rawsock(sk)->tx_work_scheduled = false;
318 
319 	return 0;
320 }
321 
322 static struct proto rawsock_proto = {
323 	.name     = "NFC_RAW",
324 	.owner    = THIS_MODULE,
325 	.obj_size = sizeof(struct nfc_rawsock),
326 };
327 
328 static const struct nfc_protocol rawsock_nfc_proto = {
329 	.id	  = NFC_SOCKPROTO_RAW,
330 	.proto    = &rawsock_proto,
331 	.owner    = THIS_MODULE,
332 	.create   = rawsock_create
333 };
334 
335 int __init rawsock_init(void)
336 {
337 	int rc;
338 
339 	rc = nfc_proto_register(&rawsock_nfc_proto);
340 
341 	return rc;
342 }
343 
344 void rawsock_exit(void)
345 {
346 	nfc_proto_unregister(&rawsock_nfc_proto);
347 }
348