diff options
Diffstat (limited to 'net/netfilter/xt_nat.c')
| -rw-r--r-- | net/netfilter/xt_nat.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/net/netfilter/xt_nat.c b/net/netfilter/xt_nat.c new file mode 100644 index 0000000..81aafa8 --- /dev/null +++ b/net/netfilter/xt_nat.c @@ -0,0 +1,170 @@ +/* + * (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> + * (C) 2011 Patrick McHardy <kaber@trash.net> + * + * 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 <linux/module.h> +#include <linux/skbuff.h> +#include <linux/netfilter.h> +#include <linux/netfilter/x_tables.h> +#include <net/netfilter/nf_nat_core.h> + +static int xt_nat_checkentry_v0(const struct xt_tgchk_param *par) +{ + const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo; + + if (mr->rangesize != 1) { + pr_info("%s: multiple ranges no longer supported\n", + par->target->name); + return -EINVAL; + } + return 0; +} + +static void xt_nat_convert_range(struct nf_nat_range *dst, + const struct nf_nat_ipv4_range *src) +{ + memset(&dst->min_addr, 0, sizeof(dst->min_addr)); + memset(&dst->max_addr, 0, sizeof(dst->max_addr)); + + dst->flags = src->flags; + dst->min_addr.ip = src->min_ip; + dst->max_addr.ip = src->max_ip; + dst->min_proto = src->min; + dst->max_proto = src->max; +} + +static unsigned int +xt_snat_target_v0(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo; + struct nf_nat_range range; + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + + ct = nf_ct_get(skb, &ctinfo); + NF_CT_ASSERT(ct != NULL && + (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED || + ctinfo == IP_CT_RELATED_REPLY)); + + xt_nat_convert_range(&range, &mr->range[0]); + return nf_nat_setup_info(ct, &range, NF_NAT_MANIP_SRC); +} + +static unsigned int +xt_dnat_target_v0(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct nf_nat_ipv4_multi_range_compat *mr = par->targinfo; + struct nf_nat_range range; + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + + ct = nf_ct_get(skb, &ctinfo); + NF_CT_ASSERT(ct != NULL && + (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED)); + + xt_nat_convert_range(&range, &mr->range[0]); + return nf_nat_setup_info(ct, &range, NF_NAT_MANIP_DST); +} + +static unsigned int +xt_snat_target_v1(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct nf_nat_range *range = par->targinfo; + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + + ct = nf_ct_get(skb, &ctinfo); + NF_CT_ASSERT(ct != NULL && + (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED || + ctinfo == IP_CT_RELATED_REPLY)); + + return nf_nat_setup_info(ct, range, NF_NAT_MANIP_SRC); +} + +static unsigned int +xt_dnat_target_v1(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct nf_nat_range *range = par->targinfo; + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + + ct = nf_ct_get(skb, &ctinfo); + NF_CT_ASSERT(ct != NULL && + (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED)); + + return nf_nat_setup_info(ct, range, NF_NAT_MANIP_DST); +} + +static struct xt_target xt_nat_target_reg[] __read_mostly = { + { + .name = "SNAT", + .revision = 0, + .checkentry = xt_nat_checkentry_v0, + .target = xt_snat_target_v0, + .targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat), + .family = NFPROTO_IPV4, + .table = "nat", + .hooks = (1 << NF_INET_POST_ROUTING) | + (1 << NF_INET_LOCAL_OUT), + .me = THIS_MODULE, + }, + { + .name = "DNAT", + .revision = 0, + .checkentry = xt_nat_checkentry_v0, + .target = xt_dnat_target_v0, + .targetsize = sizeof(struct nf_nat_ipv4_multi_range_compat), + .family = NFPROTO_IPV4, + .table = "nat", + .hooks = (1 << NF_INET_PRE_ROUTING) | + (1 << NF_INET_LOCAL_IN), + .me = THIS_MODULE, + }, + { + .name = "SNAT", + .revision = 1, + .target = xt_snat_target_v1, + .targetsize = sizeof(struct nf_nat_range), + .table = "nat", + .hooks = (1 << NF_INET_POST_ROUTING) | + (1 << NF_INET_LOCAL_OUT), + .me = THIS_MODULE, + }, + { + .name = "DNAT", + .revision = 1, + .target = xt_dnat_target_v1, + .targetsize = sizeof(struct nf_nat_range), + .table = "nat", + .hooks = (1 << NF_INET_PRE_ROUTING) | + (1 << NF_INET_LOCAL_IN), + .me = THIS_MODULE, + }, +}; + +static int __init xt_nat_init(void) +{ + return xt_register_targets(xt_nat_target_reg, + ARRAY_SIZE(xt_nat_target_reg)); +} + +static void __exit xt_nat_exit(void) +{ + xt_unregister_targets(xt_nat_target_reg, ARRAY_SIZE(xt_nat_target_reg)); +} + +module_init(xt_nat_init); +module_exit(xt_nat_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_ALIAS("ipt_SNAT"); +MODULE_ALIAS("ipt_DNAT"); +MODULE_ALIAS("ip6t_SNAT"); +MODULE_ALIAS("ip6t_DNAT"); |
