1 /* Masquerade. Simple mapping which alters range to a local IP address
2 (depending on route). */
4 /* (C) 1999-2001 Paul `Rusty' Russell
5 * (C) 2002-2006 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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/module.h>
13 #include <linux/netfilter/x_tables.h>
14 #include <net/netfilter/nf_nat.h>
15 #include <net/netfilter/nf_nat_masquerade.h>
17 MODULE_LICENSE("GPL");
18 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
19 MODULE_DESCRIPTION("Xtables: automatic-address SNAT");
21 /* FIXME: Multiple targets. --RR */
22 static int masquerade_tg_check(const struct xt_tgchk_param *par)
24 const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
26 if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
27 pr_debug("bad MAP_IPS.\n");
30 if (mr->rangesize != 1) {
31 pr_debug("bad rangesize %u\n", mr->rangesize);
34 return nf_ct_netns_get(par->net, par->family);
38 masquerade_tg(struct sk_buff *skb, const struct xt_action_param *par)
40 struct nf_nat_range2 range;
41 const struct nf_nat_ipv4_multi_range_compat *mr;
44 range.flags = mr->range[0].flags;
45 range.min_proto = mr->range[0].min;
46 range.max_proto = mr->range[0].max;
48 return nf_nat_masquerade_ipv4(skb, xt_hooknum(par), &range,
52 static void masquerade_tg_destroy(const struct xt_tgdtor_param *par)
54 nf_ct_netns_put(par->net, par->family);
57 #if IS_ENABLED(CONFIG_IPV6)
59 masquerade_tg6(struct sk_buff *skb, const struct xt_action_param *par)
61 return nf_nat_masquerade_ipv6(skb, par->targinfo, xt_out(par));
64 static int masquerade_tg6_checkentry(const struct xt_tgchk_param *par)
66 const struct nf_nat_range2 *range = par->targinfo;
68 if (range->flags & NF_NAT_RANGE_MAP_IPS)
71 return nf_ct_netns_get(par->net, par->family);
75 static struct xt_target masquerade_tg_reg[] __read_mostly = {
77 #if IS_ENABLED(CONFIG_IPV6)
79 .family = NFPROTO_IPV6,
80 .target = masquerade_tg6,
81 .targetsize = sizeof(struct nf_nat_range),
83 .hooks = 1 << NF_INET_POST_ROUTING,
84 .checkentry = masquerade_tg6_checkentry,
85 .destroy = masquerade_tg_destroy,
90 .family = NFPROTO_IPV4,
91 .target = masquerade_tg,
92 .targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat),
94 .hooks = 1 << NF_INET_POST_ROUTING,
95 .checkentry = masquerade_tg_check,
96 .destroy = masquerade_tg_destroy,
101 static int __init masquerade_tg_init(void)
105 ret = xt_register_targets(masquerade_tg_reg,
106 ARRAY_SIZE(masquerade_tg_reg));
110 ret = nf_nat_masquerade_inet_register_notifiers();
112 xt_unregister_targets(masquerade_tg_reg,
113 ARRAY_SIZE(masquerade_tg_reg));
120 static void __exit masquerade_tg_exit(void)
122 xt_unregister_targets(masquerade_tg_reg, ARRAY_SIZE(masquerade_tg_reg));
123 nf_nat_masquerade_inet_unregister_notifiers();
126 module_init(masquerade_tg_init);
127 module_exit(masquerade_tg_exit);
128 #if IS_ENABLED(CONFIG_IPV6)
129 MODULE_ALIAS("ip6t_MASQUERADE");
131 MODULE_ALIAS("ipt_MASQUERADE");