From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- net/ipv4/netfilter/iptable_nat.c | 154 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 154 insertions(+) create mode 100644 net/ipv4/netfilter/iptable_nat.c (limited to 'net/ipv4/netfilter/iptable_nat.c') diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c new file mode 100644 index 000000000..0d4d9cdf9 --- /dev/null +++ b/net/ipv4/netfilter/iptable_nat.c @@ -0,0 +1,154 @@ +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2006 Netfilter Core Team + * (C) 2011 Patrick McHardy + * + * 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. + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +static const struct xt_table nf_nat_ipv4_table = { + .name = "nat", + .valid_hooks = (1 << NF_INET_PRE_ROUTING) | + (1 << NF_INET_POST_ROUTING) | + (1 << NF_INET_LOCAL_OUT) | + (1 << NF_INET_LOCAL_IN), + .me = THIS_MODULE, + .af = NFPROTO_IPV4, +}; + +static unsigned int iptable_nat_do_chain(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct nf_hook_state *state, + struct nf_conn *ct) +{ + struct net *net = nf_ct_net(ct); + + return ipt_do_table(skb, ops->hooknum, state, net->ipv4.nat_table); +} + +static unsigned int iptable_nat_ipv4_fn(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + return nf_nat_ipv4_fn(ops, skb, state, iptable_nat_do_chain); +} + +static unsigned int iptable_nat_ipv4_in(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + return nf_nat_ipv4_in(ops, skb, state, iptable_nat_do_chain); +} + +static unsigned int iptable_nat_ipv4_out(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + return nf_nat_ipv4_out(ops, skb, state, iptable_nat_do_chain); +} + +static unsigned int iptable_nat_ipv4_local_fn(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + return nf_nat_ipv4_local_fn(ops, skb, state, iptable_nat_do_chain); +} + +static struct nf_hook_ops nf_nat_ipv4_ops[] __read_mostly = { + /* Before packet filtering, change destination */ + { + .hook = iptable_nat_ipv4_in, + .owner = THIS_MODULE, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_PRE_ROUTING, + .priority = NF_IP_PRI_NAT_DST, + }, + /* After packet filtering, change source */ + { + .hook = iptable_nat_ipv4_out, + .owner = THIS_MODULE, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_POST_ROUTING, + .priority = NF_IP_PRI_NAT_SRC, + }, + /* Before packet filtering, change destination */ + { + .hook = iptable_nat_ipv4_local_fn, + .owner = THIS_MODULE, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_NAT_DST, + }, + /* After packet filtering, change source */ + { + .hook = iptable_nat_ipv4_fn, + .owner = THIS_MODULE, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_IN, + .priority = NF_IP_PRI_NAT_SRC, + }, +}; + +static int __net_init iptable_nat_net_init(struct net *net) +{ + struct ipt_replace *repl; + + repl = ipt_alloc_initial_table(&nf_nat_ipv4_table); + if (repl == NULL) + return -ENOMEM; + net->ipv4.nat_table = ipt_register_table(net, &nf_nat_ipv4_table, repl); + kfree(repl); + return PTR_ERR_OR_ZERO(net->ipv4.nat_table); +} + +static void __net_exit iptable_nat_net_exit(struct net *net) +{ + ipt_unregister_table(net, net->ipv4.nat_table); +} + +static struct pernet_operations iptable_nat_net_ops = { + .init = iptable_nat_net_init, + .exit = iptable_nat_net_exit, +}; + +static int __init iptable_nat_init(void) +{ + int err; + + err = register_pernet_subsys(&iptable_nat_net_ops); + if (err < 0) + goto err1; + + err = nf_register_hooks(nf_nat_ipv4_ops, ARRAY_SIZE(nf_nat_ipv4_ops)); + if (err < 0) + goto err2; + return 0; + +err2: + unregister_pernet_subsys(&iptable_nat_net_ops); +err1: + return err; +} + +static void __exit iptable_nat_exit(void) +{ + nf_unregister_hooks(nf_nat_ipv4_ops, ARRAY_SIZE(nf_nat_ipv4_ops)); + unregister_pernet_subsys(&iptable_nat_net_ops); +} + +module_init(iptable_nat_init); +module_exit(iptable_nat_exit); + +MODULE_LICENSE("GPL"); -- cgit v1.2.3-54-g00ecf