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author | Pablo Neira Ayuso <pablo@netfilter.org> | 2014-10-13 19:50:22 +0200 |
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committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2014-10-13 20:42:00 +0200 |
commit | 7210e4e38f945dfa173c4a4e59ad827c9ecad541 (patch) | |
tree | f86826588257abd66235761163e113bfdd82594f /net/netfilter/nft_nat.c | |
parent | ab2d7251d666995740da17b2a51ca545ac5dd037 (diff) | |
download | op-kernel-dev-7210e4e38f945dfa173c4a4e59ad827c9ecad541.zip op-kernel-dev-7210e4e38f945dfa173c4a4e59ad827c9ecad541.tar.gz |
netfilter: nf_tables: restrict nat/masq expressions to nat chain type
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>
Diffstat (limited to 'net/netfilter/nft_nat.c')
-rw-r--r-- | net/netfilter/nft_nat.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/net/netfilter/nft_nat.c b/net/netfilter/nft_nat.c index 799550b..0f0af6e 100644 --- a/net/netfilter/nft_nat.c +++ b/net/netfilter/nft_nat.c @@ -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 = { |