![Arturo Borrero](/assets/img/avatar_default.png)
Let's refactor the code so we can reach the masquerade functionality from outside the xt context (ie. nftables). The patch includes the addition of an atomic counter to the masquerade notifier: the stuff to be done by the notifier is the same for xt and nftables. Therefore, only one notification handler is needed. This factorization only involves IPv4; a similar patch follows to handle IPv6. Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
92 lines
2.4 KiB
C
92 lines
2.4 KiB
C
/* 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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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/types.h>
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#include <linux/inetdevice.h>
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#include <linux/ip.h>
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#include <linux/timer.h>
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#include <linux/module.h>
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#include <linux/netfilter.h>
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#include <net/protocol.h>
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#include <net/ip.h>
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#include <net/checksum.h>
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#include <net/route.h>
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#include <linux/netfilter_ipv4.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/ipv4/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 0;
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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_range 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, par->hooknum, &range, par->out);
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}
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static struct xt_target masquerade_tg_reg __read_mostly = {
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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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.me = THIS_MODULE,
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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_target(&masquerade_tg_reg);
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if (ret == 0)
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nf_nat_masquerade_ipv4_register_notifier();
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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_target(&masquerade_tg_reg);
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nf_nat_masquerade_ipv4_unregister_notifier();
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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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