// SPDX-License-Identifier: GPL-2.0-only/* Masquerade.  Simple mapping which alters range to a local IP address   (depending on route). */ /* (C) 1999-2001 Paul `Rusty' Russell * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> */#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt#include <linux/module.h>#include <linux/netfilter/x_tables.h>#include <net/netfilter/nf_nat.h>#include <net/netfilter/nf_nat_masquerade.h> MODULE_LICENSE("GPL");MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");MODULE_DESCRIPTION("Xtables: automatic-address SNAT"); /* FIXME: Multiple targets. --RR */static int masquerade_tg_check(const struct xt_tgchk_param *par){	const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo; 	if (mr->range[0].flags & NF_NAT_RANGE_MAP_IPS) {		pr_info_ratelimited("bad MAP_IPS.\n");		return -EINVAL;	}	if (mr->rangesize != 1) {		pr_info_ratelimited("bad rangesize %u\n", mr->rangesize);		return -EINVAL;	}	return nf_ct_netns_get(par->net, par->family);} static unsigned intmasquerade_tg(struct sk_buff *skb, const struct xt_action_param *par){	struct nf_nat_range2 range;	const struct nf_nat_ipv4_multi_range_compat *mr; 	mr = par->targinfo;	range.flags = mr->range[0].flags;	range.min_proto = mr->range[0].min;	range.max_proto = mr->range[0].max; 	return nf_nat_masquerade_ipv4(skb, xt_hooknum(par), &range,				      xt_out(par));} static void masquerade_tg_destroy(const struct xt_tgdtor_param *par){	nf_ct_netns_put(par->net, par->family);} #if IS_ENABLED(CONFIG_IPV6)static unsigned intmasquerade_tg6(struct sk_buff *skb, const struct xt_action_param *par){	return nf_nat_masquerade_ipv6(skb, par->targinfo, xt_out(par));} static int masquerade_tg6_checkentry(const struct xt_tgchk_param *par){	const struct nf_nat_range2 *range = par->targinfo; 	if (range->flags & NF_NAT_RANGE_MAP_IPS)		return -EINVAL; 	return nf_ct_netns_get(par->net, par->family);}#endif static struct xt_target masquerade_tg_reg[] __read_mostly = {	{#if IS_ENABLED(CONFIG_IPV6)		.name		= "MASQUERADE",		.family		= NFPROTO_IPV6,		.target		= masquerade_tg6,		.targetsize	= sizeof(struct nf_nat_range),		.table		= "nat",		.hooks		= 1 << NF_INET_POST_ROUTING,		.checkentry	= masquerade_tg6_checkentry,		.destroy	= masquerade_tg_destroy,		.me		= THIS_MODULE,	}, {#endif		.name		= "MASQUERADE",		.family		= NFPROTO_IPV4,		.target		= masquerade_tg,		.targetsize	= sizeof(struct nf_nat_ipv4_multi_range_compat),		.table		= "nat",		.hooks		= 1 << NF_INET_POST_ROUTING,		.checkentry	= masquerade_tg_check,		.destroy	= masquerade_tg_destroy,		.me		= THIS_MODULE,	}}; static int __init masquerade_tg_init(void){	int ret; 	ret = xt_register_targets(masquerade_tg_reg,				  ARRAY_SIZE(masquerade_tg_reg));	if (ret)		return ret; 	ret = nf_nat_masquerade_inet_register_notifiers();	if (ret) {		xt_unregister_targets(masquerade_tg_reg,				      ARRAY_SIZE(masquerade_tg_reg));		return ret;	} 	return ret;} static void __exit masquerade_tg_exit(void){	xt_unregister_targets(masquerade_tg_reg, ARRAY_SIZE(masquerade_tg_reg));	nf_nat_masquerade_inet_unregister_notifiers();} module_init(masquerade_tg_init);module_exit(masquerade_tg_exit);#if IS_ENABLED(CONFIG_IPV6)MODULE_ALIAS("ip6t_MASQUERADE");#endifMODULE_ALIAS("ipt_MASQUERADE");