| /* 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> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| #include <linux/types.h> |
| #include <linux/inetdevice.h> |
| #include <linux/ip.h> |
| #include <linux/timer.h> |
| #include <linux/module.h> |
| #include <linux/netfilter.h> |
| #include <net/protocol.h> |
| #include <net/ip.h> |
| #include <net/checksum.h> |
| #include <net/route.h> |
| #include <linux/netfilter_ipv4.h> |
| #include <linux/netfilter/x_tables.h> |
| #include <net/netfilter/nf_nat.h> |
| #include <net/netfilter/ipv4/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_debug("bad MAP_IPS.\n"); |
| return -EINVAL; |
| } |
| if (mr->rangesize != 1) { |
| pr_debug("bad rangesize %u\n", mr->rangesize); |
| return -EINVAL; |
| } |
| return nf_ct_netns_get(par->net, par->family); |
| } |
| |
| static unsigned int |
| masquerade_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); |
| } |
| |
| static struct xt_target masquerade_tg_reg __read_mostly = { |
| .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_target(&masquerade_tg_reg); |
| |
| if (ret == 0) |
| nf_nat_masquerade_ipv4_register_notifier(); |
| |
| return ret; |
| } |
| |
| static void __exit masquerade_tg_exit(void) |
| { |
| xt_unregister_target(&masquerade_tg_reg); |
| nf_nat_masquerade_ipv4_unregister_notifier(); |
| } |
| |
| module_init(masquerade_tg_init); |
| module_exit(masquerade_tg_exit); |