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