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/*
* "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>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/netfilter_ipv4/ip_tables.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
{
struct ipt_replace repl;
struct ipt_standard entries[3];
struct ipt_error term;
} initial_table __net_initdata = {
.repl = {
.name = "security",
.valid_hooks = SECURITY_VALID_HOOKS,
.num_entries = 4,
.size = sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error),
.hook_entry = {
[NF_INET_LOCAL_IN] = 0,
[NF_INET_FORWARD] = sizeof(struct ipt_standard),
[NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2,
},
.underflow = {
[NF_INET_LOCAL_IN] = 0,
[NF_INET_FORWARD] = sizeof(struct ipt_standard),
[NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2,
},
},
.entries = {
IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */
IPT_STANDARD_INIT(NF_ACCEPT), /* FORWARD */
IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */
},
.term = IPT_ERROR_INIT, /* ERROR */
};
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 unsigned int
iptable_security_hook(unsigned int hook, struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int (*okfn)(struct sk_buff *))
{
const struct net *net;
if (hook == NF_INET_LOCAL_OUT &&
(skb->len < sizeof(struct iphdr) ||
ip_hdrlen(skb) < sizeof(struct iphdr)))
/* Somebody is playing with raw sockets. */
return NF_ACCEPT;
net = dev_net((in != NULL) ? in : out);
return ipt_do_table(skb, hook, in, out, net->ipv4.iptable_security);
}
static struct nf_hook_ops *sectbl_ops __read_mostly;
static int __net_init iptable_security_net_init(struct net *net)
{
net->ipv4.iptable_security =
ipt_register_table(net, &security_table, &initial_table.repl);
if (IS_ERR(net->ipv4.iptable_security))
return PTR_ERR(net->ipv4.iptable_security);
return 0;
}
static void __net_exit iptable_security_net_exit(struct net *net)
{
ipt_unregister_table(net, net->ipv4.iptable_security);
}
static struct pernet_operations iptable_security_net_ops = {
.init = iptable_security_net_init,
.exit = iptable_security_net_exit,
};
static int __init iptable_security_init(void)
{
int ret;
ret = register_pernet_subsys(&iptable_security_net_ops);
if (ret < 0)
return ret;
sectbl_ops = xt_hook_link(&security_table, iptable_security_hook);
if (IS_ERR(sectbl_ops)) {
ret = PTR_ERR(sectbl_ops);
goto cleanup_table;
}
return ret;
cleanup_table:
unregister_pernet_subsys(&iptable_security_net_ops);
return ret;
}
static void __exit iptable_security_fini(void)
{
xt_hook_unlink(&security_table, sectbl_ops);
unregister_pernet_subsys(&iptable_security_net_ops);
}
module_init(iptable_security_init);
module_exit(iptable_security_fini);
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