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, see <http://www.gnu.org/licenses/>.
20 */
21
22 #include <linux/nfc.h>
23 #include <linux/module.h>
24
25 #include "nfc.h"
26
27 static DEFINE_RWLOCK(proto_tab_lock);
28 static const struct nfc_protocol *proto_tab[NFC_SOCKPROTO_MAX];
29
nfc_sock_create(struct net * net,struct socket * sock,int proto,int kern)30 static int nfc_sock_create(struct net *net, struct socket *sock, int proto,
31 int kern)
32 {
33 int rc = -EPROTONOSUPPORT;
34
35 if (net != &init_net)
36 return -EAFNOSUPPORT;
37
38 if (proto < 0 || proto >= NFC_SOCKPROTO_MAX)
39 return -EINVAL;
40
41 read_lock(&proto_tab_lock);
42 if (proto_tab[proto] && try_module_get(proto_tab[proto]->owner)) {
43 rc = proto_tab[proto]->create(net, sock, proto_tab[proto], kern);
44 module_put(proto_tab[proto]->owner);
45 }
46 read_unlock(&proto_tab_lock);
47
48 return rc;
49 }
50
51 static struct net_proto_family nfc_sock_family_ops = {
52 .owner = THIS_MODULE,
53 .family = PF_NFC,
54 .create = nfc_sock_create,
55 };
56
nfc_proto_register(const struct nfc_protocol * nfc_proto)57 int nfc_proto_register(const struct nfc_protocol *nfc_proto)
58 {
59 int rc;
60
61 if (nfc_proto->id < 0 || nfc_proto->id >= NFC_SOCKPROTO_MAX)
62 return -EINVAL;
63
64 rc = proto_register(nfc_proto->proto, 0);
65 if (rc)
66 return rc;
67
68 write_lock(&proto_tab_lock);
69 if (proto_tab[nfc_proto->id])
70 rc = -EBUSY;
71 else
72 proto_tab[nfc_proto->id] = nfc_proto;
73 write_unlock(&proto_tab_lock);
74
75 return rc;
76 }
77 EXPORT_SYMBOL(nfc_proto_register);
78
nfc_proto_unregister(const struct nfc_protocol * nfc_proto)79 void nfc_proto_unregister(const struct nfc_protocol *nfc_proto)
80 {
81 write_lock(&proto_tab_lock);
82 proto_tab[nfc_proto->id] = NULL;
83 write_unlock(&proto_tab_lock);
84
85 proto_unregister(nfc_proto->proto);
86 }
87 EXPORT_SYMBOL(nfc_proto_unregister);
88
af_nfc_init(void)89 int __init af_nfc_init(void)
90 {
91 return sock_register(&nfc_sock_family_ops);
92 }
93
af_nfc_exit(void)94 void af_nfc_exit(void)
95 {
96 sock_unregister(PF_NFC);
97 }
98