// SPDX-License-Identifier: GPL-2.0-only
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/* Masquerade. Simple mapping which alters range to a local IP address
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(depending on route). */
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/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/netfilter/x_tables.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/netfilter/nf_nat_masquerade.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
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MODULE_DESCRIPTION("Xtables: automatic-address SNAT");
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/* FIXME: Multiple targets. --RR */
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static int masquerade_tg_check(const struct xt_tgchk_param *par)
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{
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const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo;
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if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {
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pr_debug("bad MAP_IPS.\n");
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return -EINVAL;
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}
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if (mr->rangesize != 1) {
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pr_debug("bad rangesize %u\n", mr->rangesize);
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return -EINVAL;
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}
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return nf_ct_netns_get(par->net, par->family);
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}
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static unsigned int
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masquerade_tg(struct sk_buff *skb, const struct xt_action_param *par)
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{
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struct nf_nat_range2 range;
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const struct nf_nat_ipv4_multi_range_compat *mr;
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mr = par->targinfo;
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range.flags = mr->range[0].flags;
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range.min_proto = mr->range[0].min;
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range.max_proto = mr->range[0].max;
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return nf_nat_masquerade_ipv4(skb, xt_hooknum(par), &range,
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xt_out(par));
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}
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static void masquerade_tg_destroy(const struct xt_tgdtor_param *par)
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{
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nf_ct_netns_put(par->net, par->family);
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}
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#if IS_ENABLED(CONFIG_IPV6)
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static unsigned int
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masquerade_tg6(struct sk_buff *skb, const struct xt_action_param *par)
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{
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return nf_nat_masquerade_ipv6(skb, par->targinfo, xt_out(par));
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}
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static int masquerade_tg6_checkentry(const struct xt_tgchk_param *par)
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{
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const struct nf_nat_range2 *range = par->targinfo;
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if (range->flags & NF_NAT_RANGE_MAP_IPS)
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return -EINVAL;
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return nf_ct_netns_get(par->net, par->family);
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}
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#endif
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static struct xt_target masquerade_tg_reg[] __read_mostly = {
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{
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#if IS_ENABLED(CONFIG_IPV6)
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.name = "MASQUERADE",
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.family = NFPROTO_IPV6,
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.target = masquerade_tg6,
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.targetsize = sizeof(struct nf_nat_range),
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.table = "nat",
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.hooks = 1 << NF_INET_POST_ROUTING,
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.checkentry = masquerade_tg6_checkentry,
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.destroy = masquerade_tg_destroy,
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.me = THIS_MODULE,
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}, {
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#endif
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.name = "MASQUERADE",
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.family = NFPROTO_IPV4,
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.target = masquerade_tg,
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.targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat),
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.table = "nat",
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.hooks = 1 << NF_INET_POST_ROUTING,
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.checkentry = masquerade_tg_check,
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.destroy = masquerade_tg_destroy,
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.me = THIS_MODULE,
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}
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};
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static int __init masquerade_tg_init(void)
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{
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int ret;
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ret = xt_register_targets(masquerade_tg_reg,
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ARRAY_SIZE(masquerade_tg_reg));
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if (ret)
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return ret;
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ret = nf_nat_masquerade_inet_register_notifiers();
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if (ret) {
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xt_unregister_targets(masquerade_tg_reg,
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ARRAY_SIZE(masquerade_tg_reg));
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return ret;
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}
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return ret;
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}
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static void __exit masquerade_tg_exit(void)
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{
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xt_unregister_targets(masquerade_tg_reg, ARRAY_SIZE(masquerade_tg_reg));
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nf_nat_masquerade_inet_unregister_notifiers();
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}
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module_init(masquerade_tg_init);
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module_exit(masquerade_tg_exit);
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#if IS_ENABLED(CONFIG_IPV6)
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MODULE_ALIAS("ip6t_MASQUERADE");
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#endif
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MODULE_ALIAS("ipt_MASQUERADE");
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