2 * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
4 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
5 * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
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.
11 #include <linux/module.h>
12 #include <linux/netfilter_ipv4/ip_tables.h>
13 #include <linux/netdevice.h>
14 #include <linux/skbuff.h>
16 #include <net/route.h>
20 MODULE_LICENSE("GPL");
21 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
22 MODULE_DESCRIPTION("iptables mangle table");
24 #define MANGLE_VALID_HOOKS ((1 << NF_IP_PRE_ROUTING) | \
25 (1 << NF_IP_LOCAL_IN) | \
26 (1 << NF_IP_FORWARD) | \
27 (1 << NF_IP_LOCAL_OUT) | \
28 (1 << NF_IP_POST_ROUTING))
30 /* Ouch - five different hooks? Maybe this should be a config option..... -- BC */
33 struct ipt_replace repl
;
34 struct ipt_standard entries
[5];
35 struct ipt_error term
;
36 } initial_table __initdata
= {
39 .valid_hooks
= MANGLE_VALID_HOOKS
,
41 .size
= sizeof(struct ipt_standard
) * 5 + sizeof(struct ipt_error
),
43 [NF_IP_PRE_ROUTING
] = 0,
44 [NF_IP_LOCAL_IN
] = sizeof(struct ipt_standard
),
45 [NF_IP_FORWARD
] = sizeof(struct ipt_standard
) * 2,
46 [NF_IP_LOCAL_OUT
] = sizeof(struct ipt_standard
) * 3,
47 [NF_IP_POST_ROUTING
] = sizeof(struct ipt_standard
) * 4,
50 [NF_IP_PRE_ROUTING
] = 0,
51 [NF_IP_LOCAL_IN
] = sizeof(struct ipt_standard
),
52 [NF_IP_FORWARD
] = sizeof(struct ipt_standard
) * 2,
53 [NF_IP_LOCAL_OUT
] = sizeof(struct ipt_standard
) * 3,
54 [NF_IP_POST_ROUTING
] = sizeof(struct ipt_standard
) * 4,
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 */
64 .term
= IPT_ERROR_INIT
, /* ERROR */
67 static struct xt_table packet_mangler
= {
69 .valid_hooks
= MANGLE_VALID_HOOKS
,
74 /* The work comes in here from netfilter.c. */
76 ipt_route_hook(unsigned int hook
,
78 const struct net_device
*in
,
79 const struct net_device
*out
,
80 int (*okfn
)(struct sk_buff
*))
82 return ipt_do_table(skb
, hook
, in
, out
, &packet_mangler
);
86 ipt_local_hook(unsigned int hook
,
88 const struct net_device
*in
,
89 const struct net_device
*out
,
90 int (*okfn
)(struct sk_buff
*))
93 const struct iphdr
*iph
;
98 /* root is playing with raw sockets. */
99 if (skb
->len
< sizeof(struct iphdr
)
100 || ip_hdrlen(skb
) < sizeof(struct iphdr
)) {
102 printk("iptable_mangle: ignoring short SOCK_RAW "
107 /* Save things which could affect route */
114 ret
= ipt_do_table(skb
, hook
, in
, out
, &packet_mangler
);
115 /* Reroute for ANY change. */
116 if (ret
!= NF_DROP
&& ret
!= NF_STOLEN
&& ret
!= NF_QUEUE
) {
119 if (iph
->saddr
!= saddr
||
120 iph
->daddr
!= daddr
||
123 if (ip_route_me_harder(skb
, RTN_UNSPEC
))
130 static struct nf_hook_ops ipt_ops
[] = {
132 .hook
= ipt_route_hook
,
133 .owner
= THIS_MODULE
,
135 .hooknum
= NF_IP_PRE_ROUTING
,
136 .priority
= NF_IP_PRI_MANGLE
,
139 .hook
= ipt_route_hook
,
140 .owner
= THIS_MODULE
,
142 .hooknum
= NF_IP_LOCAL_IN
,
143 .priority
= NF_IP_PRI_MANGLE
,
146 .hook
= ipt_route_hook
,
147 .owner
= THIS_MODULE
,
149 .hooknum
= NF_IP_FORWARD
,
150 .priority
= NF_IP_PRI_MANGLE
,
153 .hook
= ipt_local_hook
,
154 .owner
= THIS_MODULE
,
156 .hooknum
= NF_IP_LOCAL_OUT
,
157 .priority
= NF_IP_PRI_MANGLE
,
160 .hook
= ipt_route_hook
,
161 .owner
= THIS_MODULE
,
163 .hooknum
= NF_IP_POST_ROUTING
,
164 .priority
= NF_IP_PRI_MANGLE
,
168 static int __init
iptable_mangle_init(void)
173 ret
= ipt_register_table(&packet_mangler
, &initial_table
.repl
);
178 ret
= nf_register_hooks(ipt_ops
, ARRAY_SIZE(ipt_ops
));
180 ipt_unregister_table(&packet_mangler
);
185 static void __exit
iptable_mangle_fini(void)
187 nf_unregister_hooks(ipt_ops
, ARRAY_SIZE(ipt_ops
));
188 ipt_unregister_table(&packet_mangler
);
191 module_init(iptable_mangle_init
);
192 module_exit(iptable_mangle_fini
);