1 /*
2 * Copyright (C) 2011 Instituto Nokia de Tecnologia
3 *
4 * Authors:
5 * Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
6 * Lauro Ramos Venancio <lauro.venancio@openbossa.org>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the
20 * Free Software Foundation, Inc.,
21 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 */
23
24 #include <linux/nfc.h>
25 #include <linux/module.h>
26
27 #include "nfc.h"
28
29 static DEFINE_RWLOCK(proto_tab_lock);
30 static const struct nfc_protocol *proto_tab[NFC_SOCKPROTO_MAX];
31
nfc_sock_create(struct net * net,struct socket * sock,int proto,int kern)32 static int nfc_sock_create(struct net *net, struct socket *sock, int proto,
33 int kern)
34 {
35 int rc = -EPROTONOSUPPORT;
36
37 if (net != &init_net)
38 return -EAFNOSUPPORT;
39
40 if (proto < 0 || proto >= NFC_SOCKPROTO_MAX)
41 return -EINVAL;
42
43 read_lock(&proto_tab_lock);
44 if (proto_tab[proto] && try_module_get(proto_tab[proto]->owner)) {
45 rc = proto_tab[proto]->create(net, sock, proto_tab[proto]);
46 module_put(proto_tab[proto]->owner);
47 }
48 read_unlock(&proto_tab_lock);
49
50 return rc;
51 }
52
53 static struct net_proto_family nfc_sock_family_ops = {
54 .owner = THIS_MODULE,
55 .family = PF_NFC,
56 .create = nfc_sock_create,
57 };
58
nfc_proto_register(const struct nfc_protocol * nfc_proto)59 int nfc_proto_register(const struct nfc_protocol *nfc_proto)
60 {
61 int rc;
62
63 if (nfc_proto->id < 0 || nfc_proto->id >= NFC_SOCKPROTO_MAX)
64 return -EINVAL;
65
66 rc = proto_register(nfc_proto->proto, 0);
67 if (rc)
68 return rc;
69
70 write_lock(&proto_tab_lock);
71 if (proto_tab[nfc_proto->id])
72 rc = -EBUSY;
73 else
74 proto_tab[nfc_proto->id] = nfc_proto;
75 write_unlock(&proto_tab_lock);
76
77 return rc;
78 }
79 EXPORT_SYMBOL(nfc_proto_register);
80
nfc_proto_unregister(const struct nfc_protocol * nfc_proto)81 void nfc_proto_unregister(const struct nfc_protocol *nfc_proto)
82 {
83 write_lock(&proto_tab_lock);
84 proto_tab[nfc_proto->id] = NULL;
85 write_unlock(&proto_tab_lock);
86
87 proto_unregister(nfc_proto->proto);
88 }
89 EXPORT_SYMBOL(nfc_proto_unregister);
90
af_nfc_init(void)91 int __init af_nfc_init(void)
92 {
93 return sock_register(&nfc_sock_family_ops);
94 }
95
af_nfc_exit(void)96 void af_nfc_exit(void)
97 {
98 sock_unregister(PF_NFC);
99 }
100