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/*
* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
* Copyright (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
* Copyright (c) 2012 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/string.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_core.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_nat_l3proto.h>
#include <net/ip.h>
struct nft_nat {
enum nft_registers sreg_addr_min:8;
enum nft_registers sreg_addr_max:8;
enum nft_registers sreg_proto_min:8;
enum nft_registers sreg_proto_max:8;
enum nf_nat_manip_type type:8;
u8 family;
u16 flags;
};
static void nft_nat_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_nat *priv = nft_expr_priv(expr);
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(pkt->skb, &ctinfo);
struct nf_nat_range range;
memset(&range, 0, sizeof(range));
if (priv->sreg_addr_min) {
if (priv->family == AF_INET) {
range.min_addr.ip = (__force __be32)
regs->data[priv->sreg_addr_min];
range.max_addr.ip = (__force __be32)
regs->data[priv->sreg_addr_max];
} else {
memcpy(range.min_addr.ip6,
®s->data[priv->sreg_addr_min],
sizeof(range.min_addr.ip6));
memcpy(range.max_addr.ip6,
®s->data[priv->sreg_addr_max],
sizeof(range.max_addr.ip6));
}
range.flags |= NF_NAT_RANGE_MAP_IPS;
}
if (priv->sreg_proto_min) {
range.min_proto.all = (__force __be16)nft_reg_load16(
®s->data[priv->sreg_proto_min]);
range.max_proto.all = (__force __be16)nft_reg_load16(
®s->data[priv->sreg_proto_max]);
range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
}
range.flags |= priv->flags;
regs->verdict.code = nf_nat_setup_info(ct, &range, priv->type);
}
static const struct nla_policy nft_nat_policy[NFTA_NAT_MAX + 1] = {
[NFTA_NAT_TYPE] = { .type = NLA_U32 },
[NFTA_NAT_FAMILY] = { .type = NLA_U32 },
[NFTA_NAT_REG_ADDR_MIN] = { .type = NLA_U32 },
[NFTA_NAT_REG_ADDR_MAX] = { .type = NLA_U32 },
[NFTA_NAT_REG_PROTO_MIN] = { .type = NLA_U32 },
[NFTA_NAT_REG_PROTO_MAX] = { .type = NLA_U32 },
[NFTA_NAT_FLAGS] = { .type = NLA_U32 },
};
static int nft_nat_validate(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nft_data **data)
{
struct nft_nat *priv = nft_expr_priv(expr);
int err;
err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
if (err < 0)
return err;
switch (priv->type) {
case NFT_NAT_SNAT:
err = nft_chain_validate_hooks(ctx->chain,
(1 << NF_INET_POST_ROUTING) |
(1 << NF_INET_LOCAL_IN));
break;
case NFT_NAT_DNAT:
err = nft_chain_validate_hooks(ctx->chain,
(1 << NF_INET_PRE_ROUTING) |
(1 << NF_INET_LOCAL_OUT));
break;
}
return err;
}
static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_nat *priv = nft_expr_priv(expr);
unsigned int alen, plen;
u32 family;
int err;
if (tb[NFTA_NAT_TYPE] == NULL ||
(tb[NFTA_NAT_REG_ADDR_MIN] == NULL &&
tb[NFTA_NAT_REG_PROTO_MIN] == NULL))
return -EINVAL;
switch (ntohl(nla_get_be32(tb[NFTA_NAT_TYPE]))) {
case NFT_NAT_SNAT:
priv->type = NF_NAT_MANIP_SRC;
break;
case NFT_NAT_DNAT:
priv->type = NF_NAT_MANIP_DST;
break;
default:
return -EINVAL;
}
err = nft_nat_validate(ctx, expr, NULL);
if (err < 0)
return err;
if (tb[NFTA_NAT_FAMILY] == NULL)
return -EINVAL;
family = ntohl(nla_get_be32(tb[NFTA_NAT_FAMILY]));
if (family != ctx->afi->family)
return -EOPNOTSUPP;
switch (family) {
case NFPROTO_IPV4:
alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip);
break;
case NFPROTO_IPV6:
alen = FIELD_SIZEOF(struct nf_nat_range, min_addr.ip6);
break;
default:
return -EAFNOSUPPORT;
}
priv->family = family;
if (tb[NFTA_NAT_REG_ADDR_MIN]) {
priv->sreg_addr_min =
nft_parse_register(tb[NFTA_NAT_REG_ADDR_MIN]);
err = nft_validate_register_load(priv->sreg_addr_min, alen);
if (err < 0)
return err;
if (tb[NFTA_NAT_REG_ADDR_MAX]) {
priv->sreg_addr_max =
nft_parse_register(tb[NFTA_NAT_REG_ADDR_MAX]);
err = nft_validate_register_load(priv->sreg_addr_max,
alen);
if (err < 0)
return err;
} else {
priv->sreg_addr_max = priv->sreg_addr_min;
}
}
plen = FIELD_SIZEOF(struct nf_nat_range, min_addr.all);
if (tb[NFTA_NAT_REG_PROTO_MIN]) {
priv->sreg_proto_min =
nft_parse_register(tb[NFTA_NAT_REG_PROTO_MIN]);
err = nft_validate_register_load(priv->sreg_proto_min, plen);
if (err < 0)
return err;
if (tb[NFTA_NAT_REG_PROTO_MAX]) {
priv->sreg_proto_max =
nft_parse_register(tb[NFTA_NAT_REG_PROTO_MAX]);
err = nft_validate_register_load(priv->sreg_proto_max,
plen);
if (err < 0)
return err;
} else {
priv->sreg_proto_max = priv->sreg_proto_min;
}
}
if (tb[NFTA_NAT_FLAGS]) {
priv->flags = ntohl(nla_get_be32(tb[NFTA_NAT_FLAGS]));
if (priv->flags & ~NF_NAT_RANGE_MASK)
return -EINVAL;
}
return nf_ct_netns_get(ctx->net, family);
}
static int nft_nat_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_nat *priv = nft_expr_priv(expr);
switch (priv->type) {
case NF_NAT_MANIP_SRC:
if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_SNAT)))
goto nla_put_failure;
break;
case NF_NAT_MANIP_DST:
if (nla_put_be32(skb, NFTA_NAT_TYPE, htonl(NFT_NAT_DNAT)))
goto nla_put_failure;
break;
}
if (nla_put_be32(skb, NFTA_NAT_FAMILY, htonl(priv->family)))
goto nla_put_failure;
if (priv->sreg_addr_min) {
if (nft_dump_register(skb, NFTA_NAT_REG_ADDR_MIN,
priv->sreg_addr_min) ||
nft_dump_register(skb, NFTA_NAT_REG_ADDR_MAX,
priv->sreg_addr_max))
goto nla_put_failure;
}
if (priv->sreg_proto_min) {
if (nft_dump_register(skb, NFTA_NAT_REG_PROTO_MIN,
priv->sreg_proto_min) ||
nft_dump_register(skb, NFTA_NAT_REG_PROTO_MAX,
priv->sreg_proto_max))
goto nla_put_failure;
}
if (priv->flags != 0) {
if (nla_put_be32(skb, NFTA_NAT_FLAGS, htonl(priv->flags)))
goto nla_put_failure;
}
return 0;
nla_put_failure:
return -1;
}
static void
nft_nat_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
{
const struct nft_nat *priv = nft_expr_priv(expr);
nf_ct_netns_put(ctx->net, priv->family);
}
static struct nft_expr_type nft_nat_type;
static const struct nft_expr_ops nft_nat_ops = {
.type = &nft_nat_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_nat)),
.eval = nft_nat_eval,
.init = nft_nat_init,
.destroy = nft_nat_destroy,
.dump = nft_nat_dump,
.validate = nft_nat_validate,
};
static struct nft_expr_type nft_nat_type __read_mostly = {
.name = "nat",
.ops = &nft_nat_ops,
.policy = nft_nat_policy,
.maxattr = NFTA_NAT_MAX,
.owner = THIS_MODULE,
};
static int __init nft_nat_module_init(void)
{
return nft_register_expr(&nft_nat_type);
}
static void __exit nft_nat_module_exit(void)
{
nft_unregister_expr(&nft_nat_type);
}
module_init(nft_nat_module_init);
module_exit(nft_nat_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>");
MODULE_ALIAS_NFT_EXPR("nat");
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