xref: /openbmc/linux/net/nfc/rawsock.c (revision 7e8cdc97)
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 #include <linux/kcov.h>
16 
17 #include "nfc.h"
18 
19 static struct nfc_sock_list raw_sk_list = {
20 	.lock = __RW_LOCK_UNLOCKED(raw_sk_list.lock)
21 };
22 
nfc_sock_link(struct nfc_sock_list * l,struct sock * sk)23 static void nfc_sock_link(struct nfc_sock_list *l, struct sock *sk)
24 {
25 	write_lock(&l->lock);
26 	sk_add_node(sk, &l->head);
27 	write_unlock(&l->lock);
28 }
29 
nfc_sock_unlink(struct nfc_sock_list * l,struct sock * sk)30 static void nfc_sock_unlink(struct nfc_sock_list *l, struct sock *sk)
31 {
32 	write_lock(&l->lock);
33 	sk_del_node_init(sk);
34 	write_unlock(&l->lock);
35 }
36 
rawsock_write_queue_purge(struct sock * sk)37 static void rawsock_write_queue_purge(struct sock *sk)
38 {
39 	pr_debug("sk=%p\n", sk);
40 
41 	spin_lock_bh(&sk->sk_write_queue.lock);
42 	__skb_queue_purge(&sk->sk_write_queue);
43 	nfc_rawsock(sk)->tx_work_scheduled = false;
44 	spin_unlock_bh(&sk->sk_write_queue.lock);
45 }
46 
rawsock_report_error(struct sock * sk,int err)47 static void rawsock_report_error(struct sock *sk, int err)
48 {
49 	pr_debug("sk=%p err=%d\n", sk, err);
50 
51 	sk->sk_shutdown = SHUTDOWN_MASK;
52 	sk->sk_err = -err;
53 	sk_error_report(sk);
54 
55 	rawsock_write_queue_purge(sk);
56 }
57 
rawsock_release(struct socket * sock)58 static int rawsock_release(struct socket *sock)
59 {
60 	struct sock *sk = sock->sk;
61 
62 	pr_debug("sock=%p sk=%p\n", sock, sk);
63 
64 	if (!sk)
65 		return 0;
66 
67 	if (sock->type == SOCK_RAW)
68 		nfc_sock_unlink(&raw_sk_list, sk);
69 
70 	sock_orphan(sk);
71 	sock_put(sk);
72 
73 	return 0;
74 }
75 
rawsock_connect(struct socket * sock,struct sockaddr * _addr,int len,int flags)76 static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
77 			   int len, int flags)
78 {
79 	struct sock *sk = sock->sk;
80 	struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr;
81 	struct nfc_dev *dev;
82 	int rc = 0;
83 
84 	pr_debug("sock=%p sk=%p flags=%d\n", sock, sk, flags);
85 
86 	if (!addr || len < sizeof(struct sockaddr_nfc) ||
87 	    addr->sa_family != AF_NFC)
88 		return -EINVAL;
89 
90 	pr_debug("addr dev_idx=%u target_idx=%u protocol=%u\n",
91 		 addr->dev_idx, addr->target_idx, addr->nfc_protocol);
92 
93 	lock_sock(sk);
94 
95 	if (sock->state == SS_CONNECTED) {
96 		rc = -EISCONN;
97 		goto error;
98 	}
99 
100 	dev = nfc_get_device(addr->dev_idx);
101 	if (!dev) {
102 		rc = -ENODEV;
103 		goto error;
104 	}
105 
106 	if (addr->target_idx > dev->target_next_idx - 1 ||
107 	    addr->target_idx < dev->target_next_idx - dev->n_targets) {
108 		rc = -EINVAL;
109 		goto put_dev;
110 	}
111 
112 	rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol);
113 	if (rc)
114 		goto put_dev;
115 
116 	nfc_rawsock(sk)->dev = dev;
117 	nfc_rawsock(sk)->target_idx = addr->target_idx;
118 	sock->state = SS_CONNECTED;
119 	sk->sk_state = TCP_ESTABLISHED;
120 	sk->sk_state_change(sk);
121 
122 	release_sock(sk);
123 	return 0;
124 
125 put_dev:
126 	nfc_put_device(dev);
127 error:
128 	release_sock(sk);
129 	return rc;
130 }
131 
rawsock_add_header(struct sk_buff * skb)132 static int rawsock_add_header(struct sk_buff *skb)
133 {
134 	*(u8 *)skb_push(skb, NFC_HEADER_SIZE) = 0;
135 
136 	return 0;
137 }
138 
rawsock_data_exchange_complete(void * context,struct sk_buff * skb,int err)139 static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb,
140 					   int err)
141 {
142 	struct sock *sk = (struct sock *) context;
143 
144 	BUG_ON(in_hardirq());
145 
146 	pr_debug("sk=%p err=%d\n", sk, err);
147 
148 	if (err)
149 		goto error;
150 
151 	err = rawsock_add_header(skb);
152 	if (err)
153 		goto error_skb;
154 
155 	err = sock_queue_rcv_skb(sk, skb);
156 	if (err)
157 		goto error_skb;
158 
159 	spin_lock_bh(&sk->sk_write_queue.lock);
160 	if (!skb_queue_empty(&sk->sk_write_queue))
161 		schedule_work(&nfc_rawsock(sk)->tx_work);
162 	else
163 		nfc_rawsock(sk)->tx_work_scheduled = false;
164 	spin_unlock_bh(&sk->sk_write_queue.lock);
165 
166 	sock_put(sk);
167 	return;
168 
169 error_skb:
170 	kfree_skb(skb);
171 
172 error:
173 	rawsock_report_error(sk, err);
174 	sock_put(sk);
175 }
176 
rawsock_tx_work(struct work_struct * work)177 static void rawsock_tx_work(struct work_struct *work)
178 {
179 	struct sock *sk = to_rawsock_sk(work);
180 	struct nfc_dev *dev = nfc_rawsock(sk)->dev;
181 	u32 target_idx = nfc_rawsock(sk)->target_idx;
182 	struct sk_buff *skb;
183 	int rc;
184 
185 	pr_debug("sk=%p target_idx=%u\n", sk, target_idx);
186 
187 	if (sk->sk_shutdown & SEND_SHUTDOWN) {
188 		rawsock_write_queue_purge(sk);
189 		return;
190 	}
191 
192 	skb = skb_dequeue(&sk->sk_write_queue);
193 	kcov_remote_start_common(skb_get_kcov_handle(skb));
194 
195 	sock_hold(sk);
196 	rc = nfc_data_exchange(dev, target_idx, skb,
197 			       rawsock_data_exchange_complete, sk);
198 	if (rc) {
199 		rawsock_report_error(sk, rc);
200 		sock_put(sk);
201 	}
202 	kcov_remote_stop();
203 }
204 
rawsock_sendmsg(struct socket * sock,struct msghdr * msg,size_t len)205 static int rawsock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
206 {
207 	struct sock *sk = sock->sk;
208 	struct nfc_dev *dev = nfc_rawsock(sk)->dev;
209 	struct sk_buff *skb;
210 	int rc;
211 
212 	pr_debug("sock=%p sk=%p len=%zu\n", sock, sk, len);
213 
214 	if (msg->msg_namelen)
215 		return -EOPNOTSUPP;
216 
217 	if (sock->state != SS_CONNECTED)
218 		return -ENOTCONN;
219 
220 	skb = nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc);
221 	if (skb == NULL)
222 		return rc;
223 
224 	rc = memcpy_from_msg(skb_put(skb, len), msg, len);
225 	if (rc < 0) {
226 		kfree_skb(skb);
227 		return rc;
228 	}
229 
230 	spin_lock_bh(&sk->sk_write_queue.lock);
231 	__skb_queue_tail(&sk->sk_write_queue, skb);
232 	if (!nfc_rawsock(sk)->tx_work_scheduled) {
233 		schedule_work(&nfc_rawsock(sk)->tx_work);
234 		nfc_rawsock(sk)->tx_work_scheduled = true;
235 	}
236 	spin_unlock_bh(&sk->sk_write_queue.lock);
237 
238 	return len;
239 }
240 
rawsock_recvmsg(struct socket * sock,struct msghdr * msg,size_t len,int flags)241 static int rawsock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
242 			   int flags)
243 {
244 	struct sock *sk = sock->sk;
245 	struct sk_buff *skb;
246 	int copied;
247 	int rc;
248 
249 	pr_debug("sock=%p sk=%p len=%zu flags=%d\n", sock, sk, len, flags);
250 
251 	skb = skb_recv_datagram(sk, flags, &rc);
252 	if (!skb)
253 		return rc;
254 
255 	copied = skb->len;
256 	if (len < copied) {
257 		msg->msg_flags |= MSG_TRUNC;
258 		copied = len;
259 	}
260 
261 	rc = skb_copy_datagram_msg(skb, 0, msg, copied);
262 
263 	skb_free_datagram(sk, skb);
264 
265 	return rc ? : copied;
266 }
267 
268 static const struct proto_ops rawsock_ops = {
269 	.family         = PF_NFC,
270 	.owner          = THIS_MODULE,
271 	.release        = rawsock_release,
272 	.bind           = sock_no_bind,
273 	.connect        = rawsock_connect,
274 	.socketpair     = sock_no_socketpair,
275 	.accept         = sock_no_accept,
276 	.getname        = sock_no_getname,
277 	.poll           = datagram_poll,
278 	.ioctl          = sock_no_ioctl,
279 	.listen         = sock_no_listen,
280 	.shutdown       = sock_no_shutdown,
281 	.sendmsg        = rawsock_sendmsg,
282 	.recvmsg        = rawsock_recvmsg,
283 	.mmap           = sock_no_mmap,
284 };
285 
286 static const struct proto_ops rawsock_raw_ops = {
287 	.family         = PF_NFC,
288 	.owner          = THIS_MODULE,
289 	.release        = rawsock_release,
290 	.bind           = sock_no_bind,
291 	.connect        = sock_no_connect,
292 	.socketpair     = sock_no_socketpair,
293 	.accept         = sock_no_accept,
294 	.getname        = sock_no_getname,
295 	.poll           = datagram_poll,
296 	.ioctl          = sock_no_ioctl,
297 	.listen         = sock_no_listen,
298 	.shutdown       = sock_no_shutdown,
299 	.sendmsg        = sock_no_sendmsg,
300 	.recvmsg        = rawsock_recvmsg,
301 	.mmap           = sock_no_mmap,
302 };
303 
rawsock_destruct(struct sock * sk)304 static void rawsock_destruct(struct sock *sk)
305 {
306 	pr_debug("sk=%p\n", sk);
307 
308 	if (sk->sk_state == TCP_ESTABLISHED) {
309 		nfc_deactivate_target(nfc_rawsock(sk)->dev,
310 				      nfc_rawsock(sk)->target_idx,
311 				      NFC_TARGET_MODE_IDLE);
312 		nfc_put_device(nfc_rawsock(sk)->dev);
313 	}
314 
315 	skb_queue_purge(&sk->sk_receive_queue);
316 
317 	if (!sock_flag(sk, SOCK_DEAD)) {
318 		pr_err("Freeing alive NFC raw socket %p\n", sk);
319 		return;
320 	}
321 }
322 
rawsock_create(struct net * net,struct socket * sock,const struct nfc_protocol * nfc_proto,int kern)323 static int rawsock_create(struct net *net, struct socket *sock,
324 			  const struct nfc_protocol *nfc_proto, int kern)
325 {
326 	struct sock *sk;
327 
328 	pr_debug("sock=%p\n", sock);
329 
330 	if ((sock->type != SOCK_SEQPACKET) && (sock->type != SOCK_RAW))
331 		return -ESOCKTNOSUPPORT;
332 
333 	if (sock->type == SOCK_RAW) {
334 		if (!ns_capable(net->user_ns, CAP_NET_RAW))
335 			return -EPERM;
336 		sock->ops = &rawsock_raw_ops;
337 	} else {
338 		sock->ops = &rawsock_ops;
339 	}
340 
341 	sk = sk_alloc(net, PF_NFC, GFP_ATOMIC, nfc_proto->proto, kern);
342 	if (!sk)
343 		return -ENOMEM;
344 
345 	sock_init_data(sock, sk);
346 	sk->sk_protocol = nfc_proto->id;
347 	sk->sk_destruct = rawsock_destruct;
348 	sock->state = SS_UNCONNECTED;
349 	if (sock->type == SOCK_RAW)
350 		nfc_sock_link(&raw_sk_list, sk);
351 	else {
352 		INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
353 		nfc_rawsock(sk)->tx_work_scheduled = false;
354 	}
355 
356 	return 0;
357 }
358 
nfc_send_to_raw_sock(struct nfc_dev * dev,struct sk_buff * skb,u8 payload_type,u8 direction)359 void nfc_send_to_raw_sock(struct nfc_dev *dev, struct sk_buff *skb,
360 			  u8 payload_type, u8 direction)
361 {
362 	struct sk_buff *skb_copy = NULL, *nskb;
363 	struct sock *sk;
364 	u8 *data;
365 
366 	read_lock(&raw_sk_list.lock);
367 
368 	sk_for_each(sk, &raw_sk_list.head) {
369 		if (!skb_copy) {
370 			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
371 						      GFP_ATOMIC, true);
372 			if (!skb_copy)
373 				continue;
374 
375 			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
376 
377 			data[0] = dev ? dev->idx : 0xFF;
378 			data[1] = direction & 0x01;
379 			data[1] |= (payload_type << 1);
380 		}
381 
382 		nskb = skb_clone(skb_copy, GFP_ATOMIC);
383 		if (!nskb)
384 			continue;
385 
386 		if (sock_queue_rcv_skb(sk, nskb))
387 			kfree_skb(nskb);
388 	}
389 
390 	read_unlock(&raw_sk_list.lock);
391 
392 	kfree_skb(skb_copy);
393 }
394 EXPORT_SYMBOL(nfc_send_to_raw_sock);
395 
396 static struct proto rawsock_proto = {
397 	.name     = "NFC_RAW",
398 	.owner    = THIS_MODULE,
399 	.obj_size = sizeof(struct nfc_rawsock),
400 };
401 
402 static const struct nfc_protocol rawsock_nfc_proto = {
403 	.id	  = NFC_SOCKPROTO_RAW,
404 	.proto    = &rawsock_proto,
405 	.owner    = THIS_MODULE,
406 	.create   = rawsock_create
407 };
408 
rawsock_init(void)409 int __init rawsock_init(void)
410 {
411 	int rc;
412 
413 	rc = nfc_proto_register(&rawsock_nfc_proto);
414 
415 	return rc;
416 }
417 
rawsock_exit(void)418 void rawsock_exit(void)
419 {
420 	nfc_proto_unregister(&rawsock_nfc_proto);
421 }
422