181 строка
4.6 KiB
C
181 строка
4.6 KiB
C
/*
|
|
* "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 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 struct xt_table security_table = {
|
|
.name = "security",
|
|
.valid_hooks = SECURITY_VALID_HOOKS,
|
|
.lock = __RW_LOCK_UNLOCKED(security_table.lock),
|
|
.me = THIS_MODULE,
|
|
.af = AF_INET,
|
|
};
|
|
|
|
static unsigned int
|
|
ipt_local_in_hook(unsigned int hook,
|
|
struct sk_buff *skb,
|
|
const struct net_device *in,
|
|
const struct net_device *out,
|
|
int (*okfn)(struct sk_buff *))
|
|
{
|
|
return ipt_do_table(skb, hook, in, out,
|
|
nf_local_in_net(in, out)->ipv4.iptable_security);
|
|
}
|
|
|
|
static unsigned int
|
|
ipt_forward_hook(unsigned int hook,
|
|
struct sk_buff *skb,
|
|
const struct net_device *in,
|
|
const struct net_device *out,
|
|
int (*okfn)(struct sk_buff *))
|
|
{
|
|
return ipt_do_table(skb, hook, in, out,
|
|
nf_forward_net(in, out)->ipv4.iptable_security);
|
|
}
|
|
|
|
static unsigned int
|
|
ipt_local_out_hook(unsigned int hook,
|
|
struct sk_buff *skb,
|
|
const struct net_device *in,
|
|
const struct net_device *out,
|
|
int (*okfn)(struct sk_buff *))
|
|
{
|
|
/* Somebody is playing with raw sockets. */
|
|
if (skb->len < sizeof(struct iphdr)
|
|
|| ip_hdrlen(skb) < sizeof(struct iphdr)) {
|
|
if (net_ratelimit())
|
|
printk(KERN_INFO "iptable_security: ignoring short "
|
|
"SOCK_RAW packet.\n");
|
|
return NF_ACCEPT;
|
|
}
|
|
return ipt_do_table(skb, hook, in, out,
|
|
nf_local_out_net(in, out)->ipv4.iptable_security);
|
|
}
|
|
|
|
static struct nf_hook_ops ipt_ops[] __read_mostly = {
|
|
{
|
|
.hook = ipt_local_in_hook,
|
|
.owner = THIS_MODULE,
|
|
.pf = PF_INET,
|
|
.hooknum = NF_INET_LOCAL_IN,
|
|
.priority = NF_IP_PRI_SECURITY,
|
|
},
|
|
{
|
|
.hook = ipt_forward_hook,
|
|
.owner = THIS_MODULE,
|
|
.pf = PF_INET,
|
|
.hooknum = NF_INET_FORWARD,
|
|
.priority = NF_IP_PRI_SECURITY,
|
|
},
|
|
{
|
|
.hook = ipt_local_out_hook,
|
|
.owner = THIS_MODULE,
|
|
.pf = PF_INET,
|
|
.hooknum = NF_INET_LOCAL_OUT,
|
|
.priority = NF_IP_PRI_SECURITY,
|
|
},
|
|
};
|
|
|
|
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->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;
|
|
|
|
ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
|
|
if (ret < 0)
|
|
goto cleanup_table;
|
|
|
|
return ret;
|
|
|
|
cleanup_table:
|
|
unregister_pernet_subsys(&iptable_security_net_ops);
|
|
return ret;
|
|
}
|
|
|
|
static void __exit iptable_security_fini(void)
|
|
{
|
|
nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
|
|
unregister_pernet_subsys(&iptable_security_net_ops);
|
|
}
|
|
|
|
module_init(iptable_security_init);
|
|
module_exit(iptable_security_fini);
|