diff options
Diffstat (limited to 'net/ipv4/netfilter/iptable_security.c')
| -rw-r--r-- | net/ipv4/netfilter/iptable_security.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/iptable_security.c b/net/ipv4/netfilter/iptable_security.c new file mode 100644 index 000000000000..db6d312128e1 --- /dev/null +++ b/net/ipv4/netfilter/iptable_security.c @@ -0,0 +1,180 @@ +/* + * "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); |