// SPDX-License-Identifier: GPL-2.0-only
/*
 * "security" table
 *
 * This is for use by Mandatory Access Control (MAC) security models,
 * which need to be able to manage security policy in separate context
 * to DAC.
 *
 * Based on iptable_mangle.c
 *
 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam <at> netfilter.org>
 * Copyright (C) 2008 Red Hat, Inc., James Morris <jmorris <at> redhat.com>
 */
#include <linux/module.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/slab.h>
#include <net/ip.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
MODULE_DESCRIPTION("iptables security table, for MAC rules");

#define SECURITY_VALID_HOOKS    (1 << NF_INET_LOCAL_IN) | \
                                (1 << NF_INET_FORWARD) | \
                                (1 << NF_INET_LOCAL_OUT)

static const struct xt_table security_table = {
        .name           = "security",
        .valid_hooks    = SECURITY_VALID_HOOKS,
        .me             = THIS_MODULE,
        .af             = NFPROTO_IPV4,
        .priority       = NF_IP_PRI_SECURITY,
};

static struct nf_hook_ops *sectbl_ops __read_mostly;

static int iptable_security_table_init(struct net *net)
{
        struct ipt_replace *repl;
        int ret;

        repl = ipt_alloc_initial_table(&security_table);
        if (repl == NULL)
                return -ENOMEM;
        ret = ipt_register_table(net, &security_table, repl, sectbl_ops);
        kfree(repl);
        return ret;
}

static void __net_exit iptable_security_net_pre_exit(struct net *net)
{
        ipt_unregister_table_pre_exit(net, "security");
}

static void __net_exit iptable_security_net_exit(struct net *net)
{
        ipt_unregister_table_exit(net, "security");
}

static struct pernet_operations iptable_security_net_ops = {
        .pre_exit = iptable_security_net_pre_exit,
        .exit = iptable_security_net_exit,
};

static int __init iptable_security_init(void)
{
        int ret = xt_register_template(&security_table,
                                       iptable_security_table_init);

        if (ret < 0)
                return ret;

        sectbl_ops = xt_hook_ops_alloc(&security_table, ipt_do_table);
        if (IS_ERR(sectbl_ops)) {
                xt_unregister_template(&security_table);
                return PTR_ERR(sectbl_ops);
        }

        ret = register_pernet_subsys(&iptable_security_net_ops);
        if (ret < 0) {
                xt_unregister_template(&security_table);
                kfree(sectbl_ops);
                return ret;
        }

        return ret;
}

static void __exit iptable_security_fini(void)
{
        unregister_pernet_subsys(&iptable_security_net_ops);
        kfree(sectbl_ops);
        xt_unregister_template(&security_table);
}

module_init(iptable_security_init);
module_exit(iptable_security_fini);