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. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/module.h> |
| 12 | #include <linux/netfilter_ipv4/ip_tables.h> |
| 13 | #include <linux/netdevice.h> |
| 14 | #include <linux/skbuff.h> |
| 15 | #include <net/sock.h> |
| 16 | #include <net/route.h> |
| 17 | #include <linux/ip.h> |
Arnaldo Carvalho de Melo | c9bdd4b | 2007-03-12 20:09:15 -0300 | [diff] [blame] | 18 | #include <net/ip.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | |
| 20 | MODULE_LICENSE("GPL"); |
| 21 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| 22 | MODULE_DESCRIPTION("iptables mangle table"); |
| 23 | |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 24 | #define MANGLE_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \ |
| 25 | (1 << NF_INET_LOCAL_IN) | \ |
| 26 | (1 << NF_INET_FORWARD) | \ |
| 27 | (1 << NF_INET_LOCAL_OUT) | \ |
| 28 | (1 << NF_INET_POST_ROUTING)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
| 30 | /* Ouch - five different hooks? Maybe this should be a config option..... -- BC */ |
Jan Engelhardt | 35aad0f | 2009-08-24 14:56:30 +0200 | [diff] [blame] | 31 | static const struct |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | { |
| 33 | struct ipt_replace repl; |
| 34 | struct ipt_standard entries[5]; |
| 35 | struct ipt_error term; |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 36 | } initial_table __net_initdata = { |
Patrick McHardy | 3c2ad46 | 2007-05-10 14:14:16 -0700 | [diff] [blame] | 37 | .repl = { |
| 38 | .name = "mangle", |
| 39 | .valid_hooks = MANGLE_VALID_HOOKS, |
| 40 | .num_entries = 6, |
| 41 | .size = sizeof(struct ipt_standard) * 5 + sizeof(struct ipt_error), |
| 42 | .hook_entry = { |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 43 | [NF_INET_PRE_ROUTING] = 0, |
| 44 | [NF_INET_LOCAL_IN] = sizeof(struct ipt_standard), |
| 45 | [NF_INET_FORWARD] = sizeof(struct ipt_standard) * 2, |
| 46 | [NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 3, |
| 47 | [NF_INET_POST_ROUTING] = sizeof(struct ipt_standard) * 4, |
Patrick McHardy | 3c2ad46 | 2007-05-10 14:14:16 -0700 | [diff] [blame] | 48 | }, |
| 49 | .underflow = { |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 50 | [NF_INET_PRE_ROUTING] = 0, |
| 51 | [NF_INET_LOCAL_IN] = sizeof(struct ipt_standard), |
| 52 | [NF_INET_FORWARD] = sizeof(struct ipt_standard) * 2, |
| 53 | [NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 3, |
| 54 | [NF_INET_POST_ROUTING] = sizeof(struct ipt_standard) * 4, |
Patrick McHardy | 3c2ad46 | 2007-05-10 14:14:16 -0700 | [diff] [blame] | 55 | }, |
| 56 | }, |
| 57 | .entries = { |
| 58 | IPT_STANDARD_INIT(NF_ACCEPT), /* PRE_ROUTING */ |
| 59 | IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_IN */ |
| 60 | IPT_STANDARD_INIT(NF_ACCEPT), /* FORWARD */ |
| 61 | IPT_STANDARD_INIT(NF_ACCEPT), /* LOCAL_OUT */ |
| 62 | IPT_STANDARD_INIT(NF_ACCEPT), /* POST_ROUTING */ |
| 63 | }, |
| 64 | .term = IPT_ERROR_INIT, /* ERROR */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | }; |
| 66 | |
Jan Engelhardt | 35aad0f | 2009-08-24 14:56:30 +0200 | [diff] [blame] | 67 | static const struct xt_table packet_mangler = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | .name = "mangle", |
| 69 | .valid_hooks = MANGLE_VALID_HOOKS, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | .me = THIS_MODULE, |
Jan Engelhardt | f88e6a8 | 2009-06-13 06:25:44 +0200 | [diff] [blame] | 71 | .af = NFPROTO_IPV4, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | }; |
| 73 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | static unsigned int |
| 75 | ipt_local_hook(unsigned int hook, |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 76 | struct sk_buff *skb, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | const struct net_device *in, |
| 78 | const struct net_device *out, |
| 79 | int (*okfn)(struct sk_buff *)) |
| 80 | { |
| 81 | unsigned int ret; |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 82 | const struct iphdr *iph; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | u_int8_t tos; |
Al Viro | 6a19d61 | 2006-09-28 14:22:24 -0700 | [diff] [blame] | 84 | __be32 saddr, daddr; |
Thomas Graf | 82e91ff | 2006-11-09 15:19:14 -0800 | [diff] [blame] | 85 | u_int32_t mark; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | |
| 87 | /* root is playing with raw sockets. */ |
Joe Perches | 3666ed1 | 2009-11-23 23:17:06 +0100 | [diff] [blame] | 88 | if (skb->len < sizeof(struct iphdr) || |
| 89 | ip_hdrlen(skb) < sizeof(struct iphdr)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | return NF_ACCEPT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | |
| 92 | /* Save things which could affect route */ |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 93 | mark = skb->mark; |
| 94 | iph = ip_hdr(skb); |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 95 | saddr = iph->saddr; |
| 96 | daddr = iph->daddr; |
| 97 | tos = iph->tos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | |
Alexey Dobriyan | 666953df | 2008-04-14 09:56:02 +0200 | [diff] [blame] | 99 | ret = ipt_do_table(skb, hook, in, out, |
Alexey Dobriyan | 48dc786 | 2008-10-08 11:35:01 +0200 | [diff] [blame] | 100 | dev_net(out)->ipv4.iptable_mangle); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | /* Reroute for ANY change. */ |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 102 | if (ret != NF_DROP && ret != NF_STOLEN && ret != NF_QUEUE) { |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 103 | iph = ip_hdr(skb); |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 104 | |
| 105 | if (iph->saddr != saddr || |
| 106 | iph->daddr != daddr || |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 107 | skb->mark != mark || |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 108 | iph->tos != tos) |
Herbert Xu | 3db05fe | 2007-10-15 00:53:15 -0700 | [diff] [blame] | 109 | if (ip_route_me_harder(skb, RTN_UNSPEC)) |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 110 | ret = NF_DROP; |
| 111 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | |
| 113 | return ret; |
| 114 | } |
| 115 | |
Jan Engelhardt | 737535c | 2009-06-13 06:46:36 +0200 | [diff] [blame^] | 116 | /* The work comes in here from netfilter.c. */ |
| 117 | static unsigned int |
| 118 | iptable_mangle_hook(unsigned int hook, |
| 119 | struct sk_buff *skb, |
| 120 | const struct net_device *in, |
| 121 | const struct net_device *out, |
| 122 | int (*okfn)(struct sk_buff *)) |
| 123 | { |
| 124 | if (hook == NF_INET_LOCAL_OUT) |
| 125 | return ipt_local_hook(hook, skb, in, out, okfn); |
| 126 | |
| 127 | /* PREROUTING/INPUT/FORWARD: */ |
| 128 | return ipt_do_table(skb, hook, in, out, |
| 129 | dev_net(in)->ipv4.iptable_mangle); |
| 130 | } |
| 131 | |
Patrick McHardy | 1999414 | 2007-12-05 01:23:00 -0800 | [diff] [blame] | 132 | static struct nf_hook_ops ipt_ops[] __read_mostly = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | { |
Jan Engelhardt | 737535c | 2009-06-13 06:46:36 +0200 | [diff] [blame^] | 134 | .hook = iptable_mangle_hook, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | .owner = THIS_MODULE, |
Jan Engelhardt | 24c232d | 2009-06-13 06:20:29 +0200 | [diff] [blame] | 136 | .pf = NFPROTO_IPV4, |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 137 | .hooknum = NF_INET_PRE_ROUTING, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | .priority = NF_IP_PRI_MANGLE, |
| 139 | }, |
| 140 | { |
Jan Engelhardt | 737535c | 2009-06-13 06:46:36 +0200 | [diff] [blame^] | 141 | .hook = iptable_mangle_hook, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | .owner = THIS_MODULE, |
Jan Engelhardt | 24c232d | 2009-06-13 06:20:29 +0200 | [diff] [blame] | 143 | .pf = NFPROTO_IPV4, |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 144 | .hooknum = NF_INET_LOCAL_IN, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | .priority = NF_IP_PRI_MANGLE, |
| 146 | }, |
| 147 | { |
Jan Engelhardt | 737535c | 2009-06-13 06:46:36 +0200 | [diff] [blame^] | 148 | .hook = iptable_mangle_hook, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | .owner = THIS_MODULE, |
Jan Engelhardt | 24c232d | 2009-06-13 06:20:29 +0200 | [diff] [blame] | 150 | .pf = NFPROTO_IPV4, |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 151 | .hooknum = NF_INET_FORWARD, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | .priority = NF_IP_PRI_MANGLE, |
| 153 | }, |
| 154 | { |
Jan Engelhardt | 737535c | 2009-06-13 06:46:36 +0200 | [diff] [blame^] | 155 | .hook = iptable_mangle_hook, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | .owner = THIS_MODULE, |
Jan Engelhardt | 24c232d | 2009-06-13 06:20:29 +0200 | [diff] [blame] | 157 | .pf = NFPROTO_IPV4, |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 158 | .hooknum = NF_INET_LOCAL_OUT, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | .priority = NF_IP_PRI_MANGLE, |
| 160 | }, |
| 161 | { |
Jan Engelhardt | 737535c | 2009-06-13 06:46:36 +0200 | [diff] [blame^] | 162 | .hook = iptable_mangle_hook, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | .owner = THIS_MODULE, |
Jan Engelhardt | 24c232d | 2009-06-13 06:20:29 +0200 | [diff] [blame] | 164 | .pf = NFPROTO_IPV4, |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 165 | .hooknum = NF_INET_POST_ROUTING, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | .priority = NF_IP_PRI_MANGLE, |
| 167 | }, |
| 168 | }; |
| 169 | |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 170 | static int __net_init iptable_mangle_net_init(struct net *net) |
| 171 | { |
| 172 | /* Register table */ |
| 173 | net->ipv4.iptable_mangle = |
| 174 | ipt_register_table(net, &packet_mangler, &initial_table.repl); |
| 175 | if (IS_ERR(net->ipv4.iptable_mangle)) |
| 176 | return PTR_ERR(net->ipv4.iptable_mangle); |
| 177 | return 0; |
| 178 | } |
| 179 | |
| 180 | static void __net_exit iptable_mangle_net_exit(struct net *net) |
| 181 | { |
Alexey Dobriyan | f54e936 | 2010-01-18 08:25:47 +0100 | [diff] [blame] | 182 | ipt_unregister_table(net, net->ipv4.iptable_mangle); |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 183 | } |
| 184 | |
| 185 | static struct pernet_operations iptable_mangle_net_ops = { |
| 186 | .init = iptable_mangle_net_init, |
| 187 | .exit = iptable_mangle_net_exit, |
| 188 | }; |
| 189 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 190 | static int __init iptable_mangle_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | { |
| 192 | int ret; |
| 193 | |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 194 | ret = register_pernet_subsys(&iptable_mangle_net_ops); |
| 195 | if (ret < 0) |
| 196 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | |
| 198 | /* Register hooks */ |
Patrick McHardy | 964ddaa | 2006-04-06 14:09:49 -0700 | [diff] [blame] | 199 | ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | if (ret < 0) |
| 201 | goto cleanup_table; |
| 202 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | return ret; |
| 204 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | cleanup_table: |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 206 | unregister_pernet_subsys(&iptable_mangle_net_ops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | return ret; |
| 208 | } |
| 209 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 210 | static void __exit iptable_mangle_fini(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | { |
Patrick McHardy | 964ddaa | 2006-04-06 14:09:49 -0700 | [diff] [blame] | 212 | nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops)); |
Alexey Dobriyan | 9335f04 | 2008-01-31 04:03:23 -0800 | [diff] [blame] | 213 | unregister_pernet_subsys(&iptable_mangle_net_ops); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | } |
| 215 | |
Andrew Morton | 65b4b4e | 2006-03-28 16:37:06 -0800 | [diff] [blame] | 216 | module_init(iptable_mangle_init); |
| 217 | module_exit(iptable_mangle_fini); |