diff options
Diffstat (limited to 'kernel/net/ipv4/netfilter/ipt_MASQUERADE.c')
-rw-r--r-- | kernel/net/ipv4/netfilter/ipt_MASQUERADE.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/kernel/net/ipv4/netfilter/ipt_MASQUERADE.c b/kernel/net/ipv4/netfilter/ipt_MASQUERADE.c new file mode 100644 index 000000000..da7f02a0b --- /dev/null +++ b/kernel/net/ipv4/netfilter/ipt_MASQUERADE.c @@ -0,0 +1,91 @@ +/* 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 0; +} + +static unsigned int +masquerade_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + struct nf_nat_range 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, par->hooknum, &range, par->out); +} + +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, + .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); |