@@ -530,6 +530,9 @@ enum nft_chain_type {
NFT_CHAIN_T_MAX
};
+int nft_chain_validate_dependency(const struct nft_chain *chain,
+ enum nft_chain_type type);
+
struct nft_stats {
u64 bytes;
u64 pkts;
@@ -13,4 +13,7 @@ int nft_masq_init(const struct nft_ctx *ctx,
int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr);
+int nft_masq_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nft_data **data);
+
#endif /* _NFT_MASQ_H_ */
@@ -39,6 +39,7 @@ static const struct nft_expr_ops nft_masq_ipv4_ops = {
.eval = nft_masq_ipv4_eval,
.init = nft_masq_init,
.dump = nft_masq_dump,
+ .validate = nft_masq_validate,
};
static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {
@@ -39,6 +39,7 @@ static const struct nft_expr_ops nft_masq_ipv6_ops = {
.eval = nft_masq_ipv6_eval,
.init = nft_masq_init,
.dump = nft_masq_dump,
+ .validate = nft_masq_validate,
};
static struct nft_expr_type nft_masq_ipv6_type __read_mostly = {
@@ -3744,6 +3744,20 @@ static const struct nfnetlink_subsystem nf_tables_subsys = {
.abort = nf_tables_abort,
};
+int nft_chain_validate_dependency(const struct nft_chain *chain,
+ enum nft_chain_type type)
+{
+ const struct nft_base_chain *basechain;
+
+ if (chain->flags & NFT_BASE_CHAIN) {
+ basechain = nft_base_chain(chain);
+ if (basechain->type->type != type)
+ return -EOPNOTSUPP;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nft_chain_validate_dependency);
+
/*
* Loop detection - walk through the ruleset beginning at the destination chain
* of a new jump until either the source chain is reached (loop) or all
@@ -26,6 +26,11 @@ int nft_masq_init(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
struct nft_masq *priv = nft_expr_priv(expr);
+ int err;
+
+ err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
+ if (err < 0)
+ return err;
if (tb[NFTA_MASQ_FLAGS] == NULL)
return 0;
@@ -55,5 +60,12 @@ nla_put_failure:
}
EXPORT_SYMBOL_GPL(nft_masq_dump);
+int nft_masq_validate(const struct nft_ctx *ctx, const struct nft_expr *expr,
+ const struct nft_data **data)
+{
+ return nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
+}
+EXPORT_SYMBOL_GPL(nft_masq_validate);
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");
@@ -95,6 +95,10 @@ static int nft_nat_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
u32 family;
int err;
+ err = nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
+ if (err < 0)
+ return err;
+
if (tb[NFTA_NAT_TYPE] == NULL)
return -EINVAL;
@@ -205,6 +209,13 @@ nla_put_failure:
return -1;
}
+static int nft_nat_validate(const struct nft_ctx *ctx,
+ const struct nft_expr *expr,
+ const struct nft_data **data)
+{
+ return nft_chain_validate_dependency(ctx->chain, NFT_CHAIN_T_NAT);
+}
+
static struct nft_expr_type nft_nat_type;
static const struct nft_expr_ops nft_nat_ops = {
.type = &nft_nat_type,
@@ -212,6 +223,7 @@ static const struct nft_expr_ops nft_nat_ops = {
.eval = nft_nat_eval,
.init = nft_nat_init,
.dump = nft_nat_dump,
+ .validate = nft_nat_validate,
};
static struct nft_expr_type nft_nat_type __read_mostly = {
This adds the missing validation code to avoid the use of nat/masq from non-nat chains. The validation assumes two possible configuration scenarios: 1) Use of nat from base chain that is not of nat type. Reject this configuration from the nft_*_init() path of the expression. 2) Use of nat from non-base chain. In this case, we have to wait until the non-base chain is referenced by at least one base chain via jump/goto. This is resolved from the nft_*_validate() path which is called from nf_tables_check_loops(). The user gets an -EOPNOTSUPP in both cases. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- include/net/netfilter/nf_tables.h | 3 +++ include/net/netfilter/nft_masq.h | 3 +++ net/ipv4/netfilter/nft_masq_ipv4.c | 1 + net/ipv6/netfilter/nft_masq_ipv6.c | 1 + net/netfilter/nf_tables_api.c | 14 ++++++++++++++ net/netfilter/nft_masq.c | 12 ++++++++++++ net/netfilter/nft_nat.c | 12 ++++++++++++ 7 files changed, 46 insertions(+)