// SPDX-License-Identifier: GPL-2.0-only
|
/*
|
* Copyright (c) 2014 Arturo Borrero Gonzalez <arturo@debian.org>
|
*/
|
|
#include <linux/kernel.h>
|
#include <linux/init.h>
|
#include <linux/module.h>
|
#include <linux/netlink.h>
|
#include <linux/netfilter.h>
|
#include <linux/netfilter/nf_tables.h>
|
#include <net/netfilter/nf_tables.h>
|
#include <net/netfilter/nf_nat.h>
|
#include <net/netfilter/nf_nat_masquerade.h>
|
|
struct nft_masq {
|
u32 flags;
|
u8 sreg_proto_min;
|
u8 sreg_proto_max;
|
};
|
|
static const struct nla_policy nft_masq_policy[NFTA_MASQ_MAX + 1] = {
|
[NFTA_MASQ_FLAGS] = { .type = NLA_U32 },
|
[NFTA_MASQ_REG_PROTO_MIN] = { .type = NLA_U32 },
|
[NFTA_MASQ_REG_PROTO_MAX] = { .type = NLA_U32 },
|
};
|
|
static int nft_masq_validate(const struct nft_ctx *ctx,
|
const struct nft_expr *expr,
|
const struct nft_data **data)
|
{
|
int err;
|
|
err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
|
if (err < 0)
|
return err;
|
|
return nft_chain_validate_hooks(ctx->chain,
|
(1 << NF_INET_POST_ROUTING));
|
}
|
|
static int nft_masq_init(const struct nft_ctx *ctx,
|
const struct nft_expr *expr,
|
const struct nlattr * const tb[])
|
{
|
u32 plen = sizeof_field(struct nf_nat_range, min_addr.all);
|
struct nft_masq *priv = nft_expr_priv(expr);
|
int err;
|
|
if (tb[NFTA_MASQ_FLAGS]) {
|
priv->flags = ntohl(nla_get_be32(tb[NFTA_MASQ_FLAGS]));
|
if (priv->flags & ~NF_NAT_RANGE_MASK)
|
return -EINVAL;
|
}
|
|
if (tb[NFTA_MASQ_REG_PROTO_MIN]) {
|
err = nft_parse_register_load(tb[NFTA_MASQ_REG_PROTO_MIN],
|
&priv->sreg_proto_min, plen);
|
if (err < 0)
|
return err;
|
|
if (tb[NFTA_MASQ_REG_PROTO_MAX]) {
|
err = nft_parse_register_load(tb[NFTA_MASQ_REG_PROTO_MAX],
|
&priv->sreg_proto_max,
|
plen);
|
if (err < 0)
|
return err;
|
} else {
|
priv->sreg_proto_max = priv->sreg_proto_min;
|
}
|
}
|
|
return nf_ct_netns_get(ctx->net, ctx->family);
|
}
|
|
static int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr)
|
{
|
const struct nft_masq *priv = nft_expr_priv(expr);
|
|
if (priv->flags != 0 &&
|
nla_put_be32(skb, NFTA_MASQ_FLAGS, htonl(priv->flags)))
|
goto nla_put_failure;
|
|
if (priv->sreg_proto_min) {
|
if (nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MIN,
|
priv->sreg_proto_min) ||
|
nft_dump_register(skb, NFTA_MASQ_REG_PROTO_MAX,
|
priv->sreg_proto_max))
|
goto nla_put_failure;
|
}
|
|
return 0;
|
|
nla_put_failure:
|
return -1;
|
}
|
|
static void nft_masq_ipv4_eval(const struct nft_expr *expr,
|
struct nft_regs *regs,
|
const struct nft_pktinfo *pkt)
|
{
|
struct nft_masq *priv = nft_expr_priv(expr);
|
struct nf_nat_range2 range;
|
|
memset(&range, 0, sizeof(range));
|
range.flags = priv->flags;
|
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]);
|
}
|
regs->verdict.code = nf_nat_masquerade_ipv4(pkt->skb, nft_hook(pkt),
|
&range, nft_out(pkt));
|
}
|
|
static void
|
nft_masq_ipv4_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
|
{
|
nf_ct_netns_put(ctx->net, NFPROTO_IPV4);
|
}
|
|
static struct nft_expr_type nft_masq_ipv4_type;
|
static const struct nft_expr_ops nft_masq_ipv4_ops = {
|
.type = &nft_masq_ipv4_type,
|
.size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
|
.eval = nft_masq_ipv4_eval,
|
.init = nft_masq_init,
|
.destroy = nft_masq_ipv4_destroy,
|
.dump = nft_masq_dump,
|
.validate = nft_masq_validate,
|
};
|
|
static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {
|
.family = NFPROTO_IPV4,
|
.name = "masq",
|
.ops = &nft_masq_ipv4_ops,
|
.policy = nft_masq_policy,
|
.maxattr = NFTA_MASQ_MAX,
|
.owner = THIS_MODULE,
|
};
|
|
#ifdef CONFIG_NF_TABLES_IPV6
|
static void nft_masq_ipv6_eval(const struct nft_expr *expr,
|
struct nft_regs *regs,
|
const struct nft_pktinfo *pkt)
|
{
|
struct nft_masq *priv = nft_expr_priv(expr);
|
struct nf_nat_range2 range;
|
|
memset(&range, 0, sizeof(range));
|
range.flags = priv->flags;
|
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]);
|
}
|
regs->verdict.code = nf_nat_masquerade_ipv6(pkt->skb, &range,
|
nft_out(pkt));
|
}
|
|
static void
|
nft_masq_ipv6_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
|
{
|
nf_ct_netns_put(ctx->net, NFPROTO_IPV6);
|
}
|
|
static struct nft_expr_type nft_masq_ipv6_type;
|
static const struct nft_expr_ops nft_masq_ipv6_ops = {
|
.type = &nft_masq_ipv6_type,
|
.size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
|
.eval = nft_masq_ipv6_eval,
|
.init = nft_masq_init,
|
.destroy = nft_masq_ipv6_destroy,
|
.dump = nft_masq_dump,
|
.validate = nft_masq_validate,
|
};
|
|
static struct nft_expr_type nft_masq_ipv6_type __read_mostly = {
|
.family = NFPROTO_IPV6,
|
.name = "masq",
|
.ops = &nft_masq_ipv6_ops,
|
.policy = nft_masq_policy,
|
.maxattr = NFTA_MASQ_MAX,
|
.owner = THIS_MODULE,
|
};
|
|
static int __init nft_masq_module_init_ipv6(void)
|
{
|
return nft_register_expr(&nft_masq_ipv6_type);
|
}
|
|
static void nft_masq_module_exit_ipv6(void)
|
{
|
nft_unregister_expr(&nft_masq_ipv6_type);
|
}
|
#else
|
static inline int nft_masq_module_init_ipv6(void) { return 0; }
|
static inline void nft_masq_module_exit_ipv6(void) {}
|
#endif
|
|
#ifdef CONFIG_NF_TABLES_INET
|
static void nft_masq_inet_eval(const struct nft_expr *expr,
|
struct nft_regs *regs,
|
const struct nft_pktinfo *pkt)
|
{
|
switch (nft_pf(pkt)) {
|
case NFPROTO_IPV4:
|
return nft_masq_ipv4_eval(expr, regs, pkt);
|
case NFPROTO_IPV6:
|
return nft_masq_ipv6_eval(expr, regs, pkt);
|
}
|
|
WARN_ON_ONCE(1);
|
}
|
|
static void
|
nft_masq_inet_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
|
{
|
nf_ct_netns_put(ctx->net, NFPROTO_INET);
|
}
|
|
static struct nft_expr_type nft_masq_inet_type;
|
static const struct nft_expr_ops nft_masq_inet_ops = {
|
.type = &nft_masq_inet_type,
|
.size = NFT_EXPR_SIZE(sizeof(struct nft_masq)),
|
.eval = nft_masq_inet_eval,
|
.init = nft_masq_init,
|
.destroy = nft_masq_inet_destroy,
|
.dump = nft_masq_dump,
|
.validate = nft_masq_validate,
|
};
|
|
static struct nft_expr_type nft_masq_inet_type __read_mostly = {
|
.family = NFPROTO_INET,
|
.name = "masq",
|
.ops = &nft_masq_inet_ops,
|
.policy = nft_masq_policy,
|
.maxattr = NFTA_MASQ_MAX,
|
.owner = THIS_MODULE,
|
};
|
|
static int __init nft_masq_module_init_inet(void)
|
{
|
return nft_register_expr(&nft_masq_inet_type);
|
}
|
|
static void nft_masq_module_exit_inet(void)
|
{
|
nft_unregister_expr(&nft_masq_inet_type);
|
}
|
#else
|
static inline int nft_masq_module_init_inet(void) { return 0; }
|
static inline void nft_masq_module_exit_inet(void) {}
|
#endif
|
|
static int __init nft_masq_module_init(void)
|
{
|
int ret;
|
|
ret = nft_masq_module_init_ipv6();
|
if (ret < 0)
|
return ret;
|
|
ret = nft_masq_module_init_inet();
|
if (ret < 0) {
|
nft_masq_module_exit_ipv6();
|
return ret;
|
}
|
|
ret = nft_register_expr(&nft_masq_ipv4_type);
|
if (ret < 0) {
|
nft_masq_module_exit_inet();
|
nft_masq_module_exit_ipv6();
|
return ret;
|
}
|
|
ret = nf_nat_masquerade_inet_register_notifiers();
|
if (ret < 0) {
|
nft_masq_module_exit_ipv6();
|
nft_masq_module_exit_inet();
|
nft_unregister_expr(&nft_masq_ipv4_type);
|
return ret;
|
}
|
|
return ret;
|
}
|
|
static void __exit nft_masq_module_exit(void)
|
{
|
nft_masq_module_exit_ipv6();
|
nft_masq_module_exit_inet();
|
nft_unregister_expr(&nft_masq_ipv4_type);
|
nf_nat_masquerade_inet_unregister_notifiers();
|
}
|
|
module_init(nft_masq_module_init);
|
module_exit(nft_masq_module_exit);
|
|
MODULE_LICENSE("GPL");
|
MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo@debian.org>");
|
MODULE_ALIAS_NFT_EXPR("masq");
|
MODULE_DESCRIPTION("Netfilter nftables masquerade expression support");
|
