xref: /kernel/linux/linux-5.10/net/nfc/rawsock.c (revision 8c2ecf20) 
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
18static struct nfc_sock_list raw_sk_list = {
19	.lock = __RW_LOCK_UNLOCKED(raw_sk_list.lock)
20};
21
22static 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
29static 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
36static 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
46static 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
57static 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
75static 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 put_dev;
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
124put_dev:
125	nfc_put_device(dev);
126error:
127	release_sock(sk);
128	return rc;
129}
130
131static int rawsock_add_header(struct sk_buff *skb)
132{
133	*(u8 *)skb_push(skb, NFC_HEADER_SIZE) = 0;
134
135	return 0;
136}
137
138static 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
168error_skb:
169	kfree_skb(skb);
170
171error:
172	rawsock_report_error(sk, err);
173	sock_put(sk);
174}
175
176static 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
202static 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
238static 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
266static 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
284static 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
302static 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
321static 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 (!ns_capable(net->user_ns, 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
357void 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}
392EXPORT_SYMBOL(nfc_send_to_raw_sock);
393
394static struct proto rawsock_proto = {
395	.name     = "NFC_RAW",
396	.owner    = THIS_MODULE,
397	.obj_size = sizeof(struct nfc_rawsock),
398};
399
400static 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
407int __init rawsock_init(void)
408{
409	int rc;
410
411	rc = nfc_proto_register(&rawsock_nfc_proto);
412
413	return rc;
414}
415
416void rawsock_exit(void)
417{
418	nfc_proto_unregister(&rawsock_nfc_proto);
419}
420