xref: /kernel/linux/linux-6.6/net/nfc/af_nfc.c (revision 62306a36)
162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-or-later
262306a36Sopenharmony_ci/*
362306a36Sopenharmony_ci * Copyright (C) 2011 Instituto Nokia de Tecnologia
462306a36Sopenharmony_ci *
562306a36Sopenharmony_ci * Authors:
662306a36Sopenharmony_ci *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
762306a36Sopenharmony_ci *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
862306a36Sopenharmony_ci */
962306a36Sopenharmony_ci
1062306a36Sopenharmony_ci#include <linux/nfc.h>
1162306a36Sopenharmony_ci#include <linux/module.h>
1262306a36Sopenharmony_ci
1362306a36Sopenharmony_ci#include "nfc.h"
1462306a36Sopenharmony_ci
1562306a36Sopenharmony_cistatic DEFINE_RWLOCK(proto_tab_lock);
1662306a36Sopenharmony_cistatic const struct nfc_protocol *proto_tab[NFC_SOCKPROTO_MAX];
1762306a36Sopenharmony_ci
1862306a36Sopenharmony_cistatic int nfc_sock_create(struct net *net, struct socket *sock, int proto,
1962306a36Sopenharmony_ci			   int kern)
2062306a36Sopenharmony_ci{
2162306a36Sopenharmony_ci	int rc = -EPROTONOSUPPORT;
2262306a36Sopenharmony_ci
2362306a36Sopenharmony_ci	if (net != &init_net)
2462306a36Sopenharmony_ci		return -EAFNOSUPPORT;
2562306a36Sopenharmony_ci
2662306a36Sopenharmony_ci	if (proto < 0 || proto >= NFC_SOCKPROTO_MAX)
2762306a36Sopenharmony_ci		return -EINVAL;
2862306a36Sopenharmony_ci
2962306a36Sopenharmony_ci	read_lock(&proto_tab_lock);
3062306a36Sopenharmony_ci	if (proto_tab[proto] &&	try_module_get(proto_tab[proto]->owner)) {
3162306a36Sopenharmony_ci		rc = proto_tab[proto]->create(net, sock, proto_tab[proto], kern);
3262306a36Sopenharmony_ci		module_put(proto_tab[proto]->owner);
3362306a36Sopenharmony_ci	}
3462306a36Sopenharmony_ci	read_unlock(&proto_tab_lock);
3562306a36Sopenharmony_ci
3662306a36Sopenharmony_ci	return rc;
3762306a36Sopenharmony_ci}
3862306a36Sopenharmony_ci
3962306a36Sopenharmony_cistatic const struct net_proto_family nfc_sock_family_ops = {
4062306a36Sopenharmony_ci	.owner  = THIS_MODULE,
4162306a36Sopenharmony_ci	.family = PF_NFC,
4262306a36Sopenharmony_ci	.create = nfc_sock_create,
4362306a36Sopenharmony_ci};
4462306a36Sopenharmony_ci
4562306a36Sopenharmony_ciint nfc_proto_register(const struct nfc_protocol *nfc_proto)
4662306a36Sopenharmony_ci{
4762306a36Sopenharmony_ci	int rc;
4862306a36Sopenharmony_ci
4962306a36Sopenharmony_ci	if (nfc_proto->id < 0 || nfc_proto->id >= NFC_SOCKPROTO_MAX)
5062306a36Sopenharmony_ci		return -EINVAL;
5162306a36Sopenharmony_ci
5262306a36Sopenharmony_ci	rc = proto_register(nfc_proto->proto, 0);
5362306a36Sopenharmony_ci	if (rc)
5462306a36Sopenharmony_ci		return rc;
5562306a36Sopenharmony_ci
5662306a36Sopenharmony_ci	write_lock(&proto_tab_lock);
5762306a36Sopenharmony_ci	if (proto_tab[nfc_proto->id])
5862306a36Sopenharmony_ci		rc = -EBUSY;
5962306a36Sopenharmony_ci	else
6062306a36Sopenharmony_ci		proto_tab[nfc_proto->id] = nfc_proto;
6162306a36Sopenharmony_ci	write_unlock(&proto_tab_lock);
6262306a36Sopenharmony_ci
6362306a36Sopenharmony_ci	if (rc)
6462306a36Sopenharmony_ci		proto_unregister(nfc_proto->proto);
6562306a36Sopenharmony_ci
6662306a36Sopenharmony_ci	return rc;
6762306a36Sopenharmony_ci}
6862306a36Sopenharmony_ciEXPORT_SYMBOL(nfc_proto_register);
6962306a36Sopenharmony_ci
7062306a36Sopenharmony_civoid nfc_proto_unregister(const struct nfc_protocol *nfc_proto)
7162306a36Sopenharmony_ci{
7262306a36Sopenharmony_ci	write_lock(&proto_tab_lock);
7362306a36Sopenharmony_ci	proto_tab[nfc_proto->id] = NULL;
7462306a36Sopenharmony_ci	write_unlock(&proto_tab_lock);
7562306a36Sopenharmony_ci
7662306a36Sopenharmony_ci	proto_unregister(nfc_proto->proto);
7762306a36Sopenharmony_ci}
7862306a36Sopenharmony_ciEXPORT_SYMBOL(nfc_proto_unregister);
7962306a36Sopenharmony_ci
8062306a36Sopenharmony_ciint __init af_nfc_init(void)
8162306a36Sopenharmony_ci{
8262306a36Sopenharmony_ci	return sock_register(&nfc_sock_family_ops);
8362306a36Sopenharmony_ci}
8462306a36Sopenharmony_ci
8562306a36Sopenharmony_civoid __exit af_nfc_exit(void)
8662306a36Sopenharmony_ci{
8762306a36Sopenharmony_ci	sock_unregister(PF_NFC);
8862306a36Sopenharmony_ci}
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