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
15 static DEFINE_RWLOCK(proto_tab_lock);
16 static const struct nfc_protocol *proto_tab[NFC_SOCKPROTO_MAX];
17
nfc_sock_create(struct net * net,struct socket * sock,int proto,int kern)18 static 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
39 static const struct net_proto_family nfc_sock_family_ops = {
40 .owner = THIS_MODULE,
41 .family = PF_NFC,
42 .create = nfc_sock_create,
43 };
44
nfc_proto_register(const struct nfc_protocol * nfc_proto)45 int 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 }
68 EXPORT_SYMBOL(nfc_proto_register);
69
nfc_proto_unregister(const struct nfc_protocol * nfc_proto)70 void 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 }
78 EXPORT_SYMBOL(nfc_proto_unregister);
79
af_nfc_init(void)80 int __init af_nfc_init(void)
81 {
82 return sock_register(&nfc_sock_family_ops);
83 }
84
af_nfc_exit(void)85 void __exit af_nfc_exit(void)
86 {
87 sock_unregister(PF_NFC);
88 }
89