1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2011 Instituto Nokia de Tecnologia
4 *
5 * Authors:
6 * Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
7 * Lauro Ramos Venancio <lauro.venancio@openbossa.org>
8 */
9
10 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
11
12 #include <net/tcp_states.h>
13 #include <linux/nfc.h>
14 #include <linux/export.h>
15
16 #include "nfc.h"
17
18 static struct nfc_sock_list raw_sk_list = {
19 .lock = __RW_LOCK_UNLOCKED(raw_sk_list.lock)
20 };
21
nfc_sock_link(struct nfc_sock_list * l,struct sock * sk)22 static void nfc_sock_link(struct nfc_sock_list *l, struct sock *sk)
23 {
24 write_lock(&l->lock);
25 sk_add_node(sk, &l->head);
26 write_unlock(&l->lock);
27 }
28
nfc_sock_unlink(struct nfc_sock_list * l,struct sock * sk)29 static void nfc_sock_unlink(struct nfc_sock_list *l, struct sock *sk)
30 {
31 write_lock(&l->lock);
32 sk_del_node_init(sk);
33 write_unlock(&l->lock);
34 }
35
rawsock_write_queue_purge(struct sock * sk)36 static void rawsock_write_queue_purge(struct sock *sk)
37 {
38 pr_debug("sk=%p\n", sk);
39
40 spin_lock_bh(&sk->sk_write_queue.lock);
41 __skb_queue_purge(&sk->sk_write_queue);
42 nfc_rawsock(sk)->tx_work_scheduled = false;
43 spin_unlock_bh(&sk->sk_write_queue.lock);
44 }
45
rawsock_report_error(struct sock * sk,int err)46 static void rawsock_report_error(struct sock *sk, int err)
47 {
48 pr_debug("sk=%p err=%d\n", sk, err);
49
50 sk->sk_shutdown = SHUTDOWN_MASK;
51 sk->sk_err = -err;
52 sk->sk_error_report(sk);
53
54 rawsock_write_queue_purge(sk);
55 }
56
rawsock_release(struct socket * sock)57 static int rawsock_release(struct socket *sock)
58 {
59 struct sock *sk = sock->sk;
60
61 pr_debug("sock=%p sk=%p\n", sock, sk);
62
63 if (!sk)
64 return 0;
65
66 if (sock->type == SOCK_RAW)
67 nfc_sock_unlink(&raw_sk_list, sk);
68
69 sock_orphan(sk);
70 sock_put(sk);
71
72 return 0;
73 }
74
rawsock_connect(struct socket * sock,struct sockaddr * _addr,int len,int flags)75 static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
76 int len, int flags)
77 {
78 struct sock *sk = sock->sk;
79 struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr;
80 struct nfc_dev *dev;
81 int rc = 0;
82
83 pr_debug("sock=%p sk=%p flags=%d\n", sock, sk, flags);
84
85 if (!addr || len < sizeof(struct sockaddr_nfc) ||
86 addr->sa_family != AF_NFC)
87 return -EINVAL;
88
89 pr_debug("addr dev_idx=%u target_idx=%u protocol=%u\n",
90 addr->dev_idx, addr->target_idx, addr->nfc_protocol);
91
92 lock_sock(sk);
93
94 if (sock->state == SS_CONNECTED) {
95 rc = -EISCONN;
96 goto error;
97 }
98
99 dev = nfc_get_device(addr->dev_idx);
100 if (!dev) {
101 rc = -ENODEV;
102 goto error;
103 }
104
105 if (addr->target_idx > dev->target_next_idx - 1 ||
106 addr->target_idx < dev->target_next_idx - dev->n_targets) {
107 rc = -EINVAL;
108 goto error;
109 }
110
111 rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol);
112 if (rc)
113 goto put_dev;
114
115 nfc_rawsock(sk)->dev = dev;
116 nfc_rawsock(sk)->target_idx = addr->target_idx;
117 sock->state = SS_CONNECTED;
118 sk->sk_state = TCP_ESTABLISHED;
119 sk->sk_state_change(sk);
120
121 release_sock(sk);
122 return 0;
123
124 put_dev:
125 nfc_put_device(dev);
126 error:
127 release_sock(sk);
128 return rc;
129 }
130
rawsock_add_header(struct sk_buff * skb)131 static int rawsock_add_header(struct sk_buff *skb)
132 {
133 *(u8 *)skb_push(skb, NFC_HEADER_SIZE) = 0;
134
135 return 0;
136 }
137
rawsock_data_exchange_complete(void * context,struct sk_buff * skb,int err)138 static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb,
139 int err)
140 {
141 struct sock *sk = (struct sock *) context;
142
143 BUG_ON(in_irq());
144
145 pr_debug("sk=%p err=%d\n", sk, err);
146
147 if (err)
148 goto error;
149
150 err = rawsock_add_header(skb);
151 if (err)
152 goto error_skb;
153
154 err = sock_queue_rcv_skb(sk, skb);
155 if (err)
156 goto error_skb;
157
158 spin_lock_bh(&sk->sk_write_queue.lock);
159 if (!skb_queue_empty(&sk->sk_write_queue))
160 schedule_work(&nfc_rawsock(sk)->tx_work);
161 else
162 nfc_rawsock(sk)->tx_work_scheduled = false;
163 spin_unlock_bh(&sk->sk_write_queue.lock);
164
165 sock_put(sk);
166 return;
167
168 error_skb:
169 kfree_skb(skb);
170
171 error:
172 rawsock_report_error(sk, err);
173 sock_put(sk);
174 }
175
rawsock_tx_work(struct work_struct * work)176 static void rawsock_tx_work(struct work_struct *work)
177 {
178 struct sock *sk = to_rawsock_sk(work);
179 struct nfc_dev *dev = nfc_rawsock(sk)->dev;
180 u32 target_idx = nfc_rawsock(sk)->target_idx;
181 struct sk_buff *skb;
182 int rc;
183
184 pr_debug("sk=%p target_idx=%u\n", sk, target_idx);
185
186 if (sk->sk_shutdown & SEND_SHUTDOWN) {
187 rawsock_write_queue_purge(sk);
188 return;
189 }
190
191 skb = skb_dequeue(&sk->sk_write_queue);
192
193 sock_hold(sk);
194 rc = nfc_data_exchange(dev, target_idx, skb,
195 rawsock_data_exchange_complete, sk);
196 if (rc) {
197 rawsock_report_error(sk, rc);
198 sock_put(sk);
199 }
200 }
201
rawsock_sendmsg(struct socket * sock,struct msghdr * msg,size_t len)202 static int rawsock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
203 {
204 struct sock *sk = sock->sk;
205 struct nfc_dev *dev = nfc_rawsock(sk)->dev;
206 struct sk_buff *skb;
207 int rc;
208
209 pr_debug("sock=%p sk=%p len=%zu\n", sock, sk, len);
210
211 if (msg->msg_namelen)
212 return -EOPNOTSUPP;
213
214 if (sock->state != SS_CONNECTED)
215 return -ENOTCONN;
216
217 skb = nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc);
218 if (skb == NULL)
219 return rc;
220
221 rc = memcpy_from_msg(skb_put(skb, len), msg, len);
222 if (rc < 0) {
223 kfree_skb(skb);
224 return rc;
225 }
226
227 spin_lock_bh(&sk->sk_write_queue.lock);
228 __skb_queue_tail(&sk->sk_write_queue, skb);
229 if (!nfc_rawsock(sk)->tx_work_scheduled) {
230 schedule_work(&nfc_rawsock(sk)->tx_work);
231 nfc_rawsock(sk)->tx_work_scheduled = true;
232 }
233 spin_unlock_bh(&sk->sk_write_queue.lock);
234
235 return len;
236 }
237
rawsock_recvmsg(struct socket * sock,struct msghdr * msg,size_t len,int flags)238 static int rawsock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
239 int flags)
240 {
241 int noblock = flags & MSG_DONTWAIT;
242 struct sock *sk = sock->sk;
243 struct sk_buff *skb;
244 int copied;
245 int rc;
246
247 pr_debug("sock=%p sk=%p len=%zu flags=%d\n", sock, sk, len, flags);
248
249 skb = skb_recv_datagram(sk, flags, noblock, &rc);
250 if (!skb)
251 return rc;
252
253 copied = skb->len;
254 if (len < copied) {
255 msg->msg_flags |= MSG_TRUNC;
256 copied = len;
257 }
258
259 rc = skb_copy_datagram_msg(skb, 0, msg, copied);
260
261 skb_free_datagram(sk, skb);
262
263 return rc ? : copied;
264 }
265
266 static const struct proto_ops rawsock_ops = {
267 .family = PF_NFC,
268 .owner = THIS_MODULE,
269 .release = rawsock_release,
270 .bind = sock_no_bind,
271 .connect = rawsock_connect,
272 .socketpair = sock_no_socketpair,
273 .accept = sock_no_accept,
274 .getname = sock_no_getname,
275 .poll = datagram_poll,
276 .ioctl = sock_no_ioctl,
277 .listen = sock_no_listen,
278 .shutdown = sock_no_shutdown,
279 .sendmsg = rawsock_sendmsg,
280 .recvmsg = rawsock_recvmsg,
281 .mmap = sock_no_mmap,
282 };
283
284 static const struct proto_ops rawsock_raw_ops = {
285 .family = PF_NFC,
286 .owner = THIS_MODULE,
287 .release = rawsock_release,
288 .bind = sock_no_bind,
289 .connect = sock_no_connect,
290 .socketpair = sock_no_socketpair,
291 .accept = sock_no_accept,
292 .getname = sock_no_getname,
293 .poll = datagram_poll,
294 .ioctl = sock_no_ioctl,
295 .listen = sock_no_listen,
296 .shutdown = sock_no_shutdown,
297 .sendmsg = sock_no_sendmsg,
298 .recvmsg = rawsock_recvmsg,
299 .mmap = sock_no_mmap,
300 };
301
rawsock_destruct(struct sock * sk)302 static void rawsock_destruct(struct sock *sk)
303 {
304 pr_debug("sk=%p\n", sk);
305
306 if (sk->sk_state == TCP_ESTABLISHED) {
307 nfc_deactivate_target(nfc_rawsock(sk)->dev,
308 nfc_rawsock(sk)->target_idx,
309 NFC_TARGET_MODE_IDLE);
310 nfc_put_device(nfc_rawsock(sk)->dev);
311 }
312
313 skb_queue_purge(&sk->sk_receive_queue);
314
315 if (!sock_flag(sk, SOCK_DEAD)) {
316 pr_err("Freeing alive NFC raw socket %p\n", sk);
317 return;
318 }
319 }
320
rawsock_create(struct net * net,struct socket * sock,const struct nfc_protocol * nfc_proto,int kern)321 static int rawsock_create(struct net *net, struct socket *sock,
322 const struct nfc_protocol *nfc_proto, int kern)
323 {
324 struct sock *sk;
325
326 pr_debug("sock=%p\n", sock);
327
328 if ((sock->type != SOCK_SEQPACKET) && (sock->type != SOCK_RAW))
329 return -ESOCKTNOSUPPORT;
330
331 if (sock->type == SOCK_RAW) {
332 if (!capable(CAP_NET_RAW))
333 return -EPERM;
334 sock->ops = &rawsock_raw_ops;
335 } else {
336 sock->ops = &rawsock_ops;
337 }
338
339 sk = sk_alloc(net, PF_NFC, GFP_ATOMIC, nfc_proto->proto, kern);
340 if (!sk)
341 return -ENOMEM;
342
343 sock_init_data(sock, sk);
344 sk->sk_protocol = nfc_proto->id;
345 sk->sk_destruct = rawsock_destruct;
346 sock->state = SS_UNCONNECTED;
347 if (sock->type == SOCK_RAW)
348 nfc_sock_link(&raw_sk_list, sk);
349 else {
350 INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
351 nfc_rawsock(sk)->tx_work_scheduled = false;
352 }
353
354 return 0;
355 }
356
nfc_send_to_raw_sock(struct nfc_dev * dev,struct sk_buff * skb,u8 payload_type,u8 direction)357 void nfc_send_to_raw_sock(struct nfc_dev *dev, struct sk_buff *skb,
358 u8 payload_type, u8 direction)
359 {
360 struct sk_buff *skb_copy = NULL, *nskb;
361 struct sock *sk;
362 u8 *data;
363
364 read_lock(&raw_sk_list.lock);
365
366 sk_for_each(sk, &raw_sk_list.head) {
367 if (!skb_copy) {
368 skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
369 GFP_ATOMIC, true);
370 if (!skb_copy)
371 continue;
372
373 data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
374
375 data[0] = dev ? dev->idx : 0xFF;
376 data[1] = direction & 0x01;
377 data[1] |= (payload_type << 1);
378 }
379
380 nskb = skb_clone(skb_copy, GFP_ATOMIC);
381 if (!nskb)
382 continue;
383
384 if (sock_queue_rcv_skb(sk, nskb))
385 kfree_skb(nskb);
386 }
387
388 read_unlock(&raw_sk_list.lock);
389
390 kfree_skb(skb_copy);
391 }
392 EXPORT_SYMBOL(nfc_send_to_raw_sock);
393
394 static struct proto rawsock_proto = {
395 .name = "NFC_RAW",
396 .owner = THIS_MODULE,
397 .obj_size = sizeof(struct nfc_rawsock),
398 };
399
400 static const struct nfc_protocol rawsock_nfc_proto = {
401 .id = NFC_SOCKPROTO_RAW,
402 .proto = &rawsock_proto,
403 .owner = THIS_MODULE,
404 .create = rawsock_create
405 };
406
rawsock_init(void)407 int __init rawsock_init(void)
408 {
409 int rc;
410
411 rc = nfc_proto_register(&rawsock_nfc_proto);
412
413 return rc;
414 }
415
rawsock_exit(void)416 void rawsock_exit(void)
417 {
418 nfc_proto_unregister(&rawsock_nfc_proto);
419 }
420
