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#include <linux/nfc.h>
11#include <linux/module.h>
12
13#include "nfc.h"
14
15static DEFINE_RWLOCK(proto_tab_lock);
16static const struct nfc_protocol *proto_tab[NFC_SOCKPROTO_MAX];
17
18static int nfc_sock_create(struct net *net, struct socket *sock, int proto,
19			   int kern)
20{
21	int rc = -EPROTONOSUPPORT;
22
23	if (net != &init_net)
24		return -EAFNOSUPPORT;
25
26	if (proto < 0 || proto >= NFC_SOCKPROTO_MAX)
27		return -EINVAL;
28
29	read_lock(&proto_tab_lock);
30	if (proto_tab[proto] &&	try_module_get(proto_tab[proto]->owner)) {
31		rc = proto_tab[proto]->create(net, sock, proto_tab[proto], kern);
32		module_put(proto_tab[proto]->owner);
33	}
34	read_unlock(&proto_tab_lock);
35
36	return rc;
37}
38
39static const struct net_proto_family nfc_sock_family_ops = {
40	.owner  = THIS_MODULE,
41	.family = PF_NFC,
42	.create = nfc_sock_create,
43};
44
45int nfc_proto_register(const struct nfc_protocol *nfc_proto)
46{
47	int rc;
48
49	if (nfc_proto->id < 0 || nfc_proto->id >= NFC_SOCKPROTO_MAX)
50		return -EINVAL;
51
52	rc = proto_register(nfc_proto->proto, 0);
53	if (rc)
54		return rc;
55
56	write_lock(&proto_tab_lock);
57	if (proto_tab[nfc_proto->id])
58		rc = -EBUSY;
59	else
60		proto_tab[nfc_proto->id] = nfc_proto;
61	write_unlock(&proto_tab_lock);
62
63	if (rc)
64		proto_unregister(nfc_proto->proto);
65
66	return rc;
67}
68EXPORT_SYMBOL(nfc_proto_register);
69
70void nfc_proto_unregister(const struct nfc_protocol *nfc_proto)
71{
72	write_lock(&proto_tab_lock);
73	proto_tab[nfc_proto->id] = NULL;
74	write_unlock(&proto_tab_lock);
75
76	proto_unregister(nfc_proto->proto);
77}
78EXPORT_SYMBOL(nfc_proto_unregister);
79
80int __init af_nfc_init(void)
81{
82	return sock_register(&nfc_sock_family_ops);
83}
84
85void __exit af_nfc_exit(void)
86{
87	sock_unregister(PF_NFC);
88}
89