James Morris | 560ee65 | 2008-06-09 15:57:24 -0700 | [diff] [blame] | 1 | /* |
| 2 | * "security" table |
| 3 | * |
| 4 | * This is for use by Mandatory Access Control (MAC) security models, |
| 5 | * which need to be able to manage security policy in separate context |
| 6 | * to DAC. |
| 7 | * |
| 8 | * Based on iptable_mangle.c |
| 9 | * |
| 10 | * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling |
| 11 | * Copyright (C) 2000-2004 Netfilter Core Team <coreteam <at> netfilter.org> |
| 12 | * Copyright (C) 2008 Red Hat, Inc., James Morris <jmorris <at> redhat.com> |
| 13 | * |
| 14 | * This program is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License version 2 as |
| 16 | * published by the Free Software Foundation. |
| 17 | */ |
| 18 | #include <linux/module.h> |
| 19 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 20 | #include <net/ip.h> |
| 21 | |
| 22 | MODULE_LICENSE("GPL"); |
| 23 | MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>"); |
| 24 | MODULE_DESCRIPTION("iptables security table, for MAC rules"); |
| 25 | |
| 26 | #define SECURITY_VALID_HOOKS (1 << NF_INET_LOCAL_IN) | \ |
| 27 | (1 << NF_INET_FORWARD) | \ |
| 28 | (1 << NF_INET_LOCAL_OUT) |
| 29 | |
| 30 | static struct |
| 31 | { |
| 32 | struct ipt_replace repl; |
| 33 | struct ipt_standard entries[3]; |
| 34 | struct ipt_error term; |
Alexey Dobriyan | f858b48 | 2008-07-26 17:48:38 -0700 | [diff] [blame^] | 35 | } initial_table __net_initdata = { |
James Morris | 560ee65 | 2008-06-09 15:57:24 -0700 | [diff] [blame] | 36 | .repl = { |
| 37 | .name = "security", |
| 38 | .valid_hooks = SECURITY_VALID_HOOKS, |
| 39 | .num_entries = 4, |
| 40 | .size = sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error), |
| 41 | .hook_entry = { |
| 42 | [NF_INET_LOCAL_IN] = 0, |
| 43 | [NF_INET_FORWARD] = sizeof(struct ipt_standard), |
| 44 | [NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2, |
| 45 | }, |
| 46 | .underflow = { |
| 47 | [NF_INET_LOCAL_IN] = 0, |
| 48 | [NF_INET_FORWARD] = sizeof(struct ipt_standard), |
| 49 | [NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2, |
| 50 | }, |
| 51 | }, |
| 52 | .entries = { |
| 53 | IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */ |
| 54 | IPT_STANDARD_INIT(NF_ACCEPT), /* FORWARD */ |
| 55 | IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */ |
| 56 | }, |
| 57 | .term = IPT_ERROR_INIT, /* ERROR */ |
| 58 | }; |
| 59 | |
| 60 | static struct xt_table security_table = { |
| 61 | .name = "security", |
| 62 | .valid_hooks = SECURITY_VALID_HOOKS, |
| 63 | .lock = __RW_LOCK_UNLOCKED(security_table.lock), |
| 64 | .me = THIS_MODULE, |
| 65 | .af = AF_INET, |
| 66 | }; |
| 67 | |
| 68 | static unsigned int |
| 69 | ipt_local_in_hook(unsigned int hook, |
| 70 | struct sk_buff *skb, |
| 71 | const struct net_device *in, |
| 72 | const struct net_device *out, |
| 73 | int (*okfn)(struct sk_buff *)) |
| 74 | { |
| 75 | return ipt_do_table(skb, hook, in, out, |
| 76 | nf_local_in_net(in, out)->ipv4.iptable_security); |
| 77 | } |
| 78 | |
| 79 | static unsigned int |
| 80 | ipt_forward_hook(unsigned int hook, |
| 81 | struct sk_buff *skb, |
| 82 | const struct net_device *in, |
| 83 | const struct net_device *out, |
| 84 | int (*okfn)(struct sk_buff *)) |
| 85 | { |
| 86 | return ipt_do_table(skb, hook, in, out, |
| 87 | nf_forward_net(in, out)->ipv4.iptable_security); |
| 88 | } |
| 89 | |
| 90 | static unsigned int |
| 91 | ipt_local_out_hook(unsigned int hook, |
| 92 | struct sk_buff *skb, |
| 93 | const struct net_device *in, |
| 94 | const struct net_device *out, |
| 95 | int (*okfn)(struct sk_buff *)) |
| 96 | { |
| 97 | /* Somebody is playing with raw sockets. */ |
| 98 | if (skb->len < sizeof(struct iphdr) |
| 99 | || ip_hdrlen(skb) < sizeof(struct iphdr)) { |
| 100 | if (net_ratelimit()) |
| 101 | printk(KERN_INFO "iptable_security: ignoring short " |
| 102 | "SOCK_RAW packet.\n"); |
| 103 | return NF_ACCEPT; |
| 104 | } |
| 105 | return ipt_do_table(skb, hook, in, out, |
| 106 | nf_local_out_net(in, out)->ipv4.iptable_security); |
| 107 | } |
| 108 | |
| 109 | static struct nf_hook_ops ipt_ops[] __read_mostly = { |
| 110 | { |
| 111 | .hook = ipt_local_in_hook, |
| 112 | .owner = THIS_MODULE, |
| 113 | .pf = PF_INET, |
| 114 | .hooknum = NF_INET_LOCAL_IN, |
| 115 | .priority = NF_IP_PRI_SECURITY, |
| 116 | }, |
| 117 | { |
| 118 | .hook = ipt_forward_hook, |
| 119 | .owner = THIS_MODULE, |
| 120 | .pf = PF_INET, |
| 121 | .hooknum = NF_INET_FORWARD, |
| 122 | .priority = NF_IP_PRI_SECURITY, |
| 123 | }, |
| 124 | { |
| 125 | .hook = ipt_local_out_hook, |
| 126 | .owner = THIS_MODULE, |
| 127 | .pf = PF_INET, |
| 128 | .hooknum = NF_INET_LOCAL_OUT, |
| 129 | .priority = NF_IP_PRI_SECURITY, |
| 130 | }, |
| 131 | }; |
| 132 | |
| 133 | static int __net_init iptable_security_net_init(struct net *net) |
| 134 | { |
| 135 | net->ipv4.iptable_security = |
| 136 | ipt_register_table(net, &security_table, &initial_table.repl); |
| 137 | |
| 138 | if (IS_ERR(net->ipv4.iptable_security)) |
| 139 | return PTR_ERR(net->ipv4.iptable_security); |
| 140 | |
| 141 | return 0; |
| 142 | } |
| 143 | |
| 144 | static void __net_exit iptable_security_net_exit(struct net *net) |
| 145 | { |
| 146 | ipt_unregister_table(net->ipv4.iptable_security); |
| 147 | } |
| 148 | |
| 149 | static struct pernet_operations iptable_security_net_ops = { |
| 150 | .init = iptable_security_net_init, |
| 151 | .exit = iptable_security_net_exit, |
| 152 | }; |
| 153 | |
| 154 | static int __init iptable_security_init(void) |
| 155 | { |
| 156 | int ret; |
| 157 | |
| 158 | ret = register_pernet_subsys(&iptable_security_net_ops); |
| 159 | if (ret < 0) |
| 160 | return ret; |
| 161 | |
| 162 | ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops)); |
| 163 | if (ret < 0) |
| 164 | goto cleanup_table; |
| 165 | |
| 166 | return ret; |
| 167 | |
| 168 | cleanup_table: |
| 169 | unregister_pernet_subsys(&iptable_security_net_ops); |
| 170 | return ret; |
| 171 | } |
| 172 | |
| 173 | static void __exit iptable_security_fini(void) |
| 174 | { |
| 175 | nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops)); |
| 176 | unregister_pernet_subsys(&iptable_security_net_ops); |
| 177 | } |
| 178 | |
| 179 | module_init(iptable_security_init); |
| 180 | module_exit(iptable_security_fini); |