Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x. |
| 3 | * |
| 4 | * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling |
| 5 | * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/moduleparam.h> |
| 15 | #include <linux/netfilter_ipv4/ip_tables.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 16 | #include <linux/slab.h> |
Arnaldo Carvalho de Melo | c9bdd4b | 2007-03-12 20:09:15 -0300 | [diff] [blame] | 17 | #include <net/ip.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | |
| 19 | MODULE_LICENSE("GPL"); |
| 20 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| 21 | MODULE_DESCRIPTION("iptables filter table"); |
| 22 | |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 23 | #define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \ |
| 24 | (1 << NF_INET_FORWARD) | \ |
| 25 | (1 << NF_INET_LOCAL_OUT)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | |
Jan Engelhardt | 35aad0f | 2009-08-24 14:56:30 +0200 | [diff] [blame] | 27 | static const struct xt_table packet_filter = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | .name = "filter", |
| 29 | .valid_hooks = FILTER_VALID_HOOKS, |
Harald Welte | 2e4e6a1 | 2006-01-12 13:30:04 -0800 | [diff] [blame] | 30 | .me = THIS_MODULE, |
Jan Engelhardt | f88e6a8 | 2009-06-13 06:25:44 +0200 | [diff] [blame] | 31 | .af = NFPROTO_IPV4, |
Jan Engelhardt | 2b95efe | 2009-06-17 13:57:48 +0200 | [diff] [blame] | 32 | .priority = NF_IP_PRI_FILTER, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | }; |
| 34 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | static unsigned int |
Jan Engelhardt | 737535c | 2009-06-13 06:46:36 +0200 | [diff] [blame] | 36 | iptable_filter_hook(unsigned int hook, struct sk_buff *skb, |
| 37 | const struct net_device *in, const struct net_device *out, |
| 38 | int (*okfn)(struct sk_buff *)) |
Alexey Dobriyan | 666953df | 2008-04-14 09:56:02 +0200 | [diff] [blame] | 39 | { |
Jan Engelhardt | 2b21e05 | 2009-06-13 06:57:10 +0200 | [diff] [blame] | 40 | const struct net *net; |
Jan Engelhardt | 737535c | 2009-06-13 06:46:36 +0200 | [diff] [blame] | 41 | |
Jan Engelhardt | 2b21e05 | 2009-06-13 06:57:10 +0200 | [diff] [blame] | 42 | if (hook == NF_INET_LOCAL_OUT && |
| 43 | (skb->len < sizeof(struct iphdr) || |
| 44 | ip_hdrlen(skb) < sizeof(struct iphdr))) |
| 45 | /* root is playing with raw sockets. */ |
| 46 | return NF_ACCEPT; |
Jan Engelhardt | 737535c | 2009-06-13 06:46:36 +0200 | [diff] [blame] | 47 | |
Jan Engelhardt | 2b21e05 | 2009-06-13 06:57:10 +0200 | [diff] [blame] | 48 | net = dev_net((in != NULL) ? in : out); |
| 49 | return ipt_do_table(skb, hook, in, out, net->ipv4.iptable_filter); |
Alexey Dobriyan | 666953df | 2008-04-14 09:56:02 +0200 | [diff] [blame] | 50 | } |
| 51 | |
Jan Engelhardt | 2b95efe | 2009-06-17 13:57:48 +0200 | [diff] [blame] | 52 | static struct nf_hook_ops *filter_ops __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
| 54 | /* Default to forward because I got too much mail already. */ |
Rusty Russell | 523f610 | 2012-03-22 12:27:06 +0000 | [diff] [blame] | 55 | static bool forward = true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | module_param(forward, bool, 0000); |
| 57 | |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 58 | static int __net_init iptable_filter_net_init(struct net *net) |
| 59 | { |
Jan Engelhardt | e3eaa99 | 2009-06-17 22:14:54 +0200 | [diff] [blame] | 60 | struct ipt_replace *repl; |
| 61 | |
| 62 | repl = ipt_alloc_initial_table(&packet_filter); |
| 63 | if (repl == NULL) |
| 64 | return -ENOMEM; |
| 65 | /* Entry 1 is the FORWARD hook */ |
| 66 | ((struct ipt_standard *)repl->entries)[1].target.verdict = |
Rusty Russell | 523f610 | 2012-03-22 12:27:06 +0000 | [diff] [blame] | 67 | forward ? -NF_ACCEPT - 1 : -NF_DROP - 1; |
Jan Engelhardt | e3eaa99 | 2009-06-17 22:14:54 +0200 | [diff] [blame] | 68 | |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 69 | net->ipv4.iptable_filter = |
Jan Engelhardt | e3eaa99 | 2009-06-17 22:14:54 +0200 | [diff] [blame] | 70 | ipt_register_table(net, &packet_filter, repl); |
| 71 | kfree(repl); |
Rusty Russell | 8c6ffba | 2013-07-15 11:20:32 +0930 | [diff] [blame] | 72 | return PTR_ERR_OR_ZERO(net->ipv4.iptable_filter); |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 73 | } |
| 74 | |
| 75 | static void __net_exit iptable_filter_net_exit(struct net *net) |
| 76 | { |
Alexey Dobriyan | f54e936 | 2010-01-18 08:25:47 +0100 | [diff] [blame] | 77 | ipt_unregister_table(net, net->ipv4.iptable_filter); |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 78 | } |
| 79 | |
| 80 | static struct pernet_operations iptable_filter_net_ops = { |
| 81 | .init = iptable_filter_net_init, |
| 82 | .exit = iptable_filter_net_exit, |
| 83 | }; |
| 84 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 85 | static int __init iptable_filter_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | { |
| 87 | int ret; |
| 88 | |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 89 | ret = register_pernet_subsys(&iptable_filter_net_ops); |
| 90 | if (ret < 0) |
| 91 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | |
| 93 | /* Register hooks */ |
Jan Engelhardt | 2b95efe | 2009-06-17 13:57:48 +0200 | [diff] [blame] | 94 | filter_ops = xt_hook_link(&packet_filter, iptable_filter_hook); |
| 95 | if (IS_ERR(filter_ops)) { |
| 96 | ret = PTR_ERR(filter_ops); |
Jean Sacren | 90efbed | 2012-08-19 15:11:32 +0000 | [diff] [blame] | 97 | unregister_pernet_subsys(&iptable_filter_net_ops); |
Jan Engelhardt | 2b95efe | 2009-06-17 13:57:48 +0200 | [diff] [blame] | 98 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | } |
| 102 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 103 | static void __exit iptable_filter_fini(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | { |
Jan Engelhardt | 2b95efe | 2009-06-17 13:57:48 +0200 | [diff] [blame] | 105 | xt_hook_unlink(&packet_filter, filter_ops); |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 106 | unregister_pernet_subsys(&iptable_filter_net_ops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | } |
| 108 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 109 | module_init(iptable_filter_init); |
| 110 | module_exit(iptable_filter_fini); |