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 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 const struct net_proto_family nfc_sock_family_ops = { 52 .owner = THIS_MODULE, 53 .family = PF_NFC, 54 .create = nfc_sock_create, 55 }; 56 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 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 89 int __init af_nfc_init(void) 90 { 91 return sock_register(&nfc_sock_family_ops); 92 } 93 94 void af_nfc_exit(void) 95 { 96 sock_unregister(PF_NFC); 97 } 98