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authorPablo Neira Ayuso <pablo@netfilter.org>2020-12-27 12:35:43 +0100
committerPablo Neira Ayuso <pablo@netfilter.org>2020-12-28 10:50:26 +0100
commitb4e70d8dd9ea6bd5d5fb3122586f652326ca09cd (patch)
tree35a39beab3e711e4a1e3d87d55c194f92a53a350 /net
parent95cd4bca7b1f4a25810f3ddfc5e767fb46931789 (diff)
netfilter: nftables: add set expression flags
The set flag NFT_SET_EXPR provides a hint to the kernel that userspace supports for multiple expressions per set element. In the same direction, NFT_DYNSET_F_EXPR specifies that dynset expression defines multiple expressions per set element. This allows new userspace software with old kernels to bail out with EOPNOTSUPP. This update is similar to ef516e8625dd ("netfilter: nf_tables: reintroduce the NFT_SET_CONCAT flag"). The NFT_SET_EXPR flag needs to be set on when the NFTA_SET_EXPRESSIONS attribute is specified. The NFT_SET_EXPR flag is not set on with NFTA_SET_EXPR to retain backward compatibility in old userspace binaries. Fixes: 48b0ae046ee9 ("netfilter: nftables: netlink support for several set element expressions") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_tables_api.c6
-rw-r--r--net/netfilter/nft_dynset.c9
2 files changed, 12 insertions, 3 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 4186b1e52d58..15c467f1a9dd 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4162,7 +4162,7 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
if (flags & ~(NFT_SET_ANONYMOUS | NFT_SET_CONSTANT |
NFT_SET_INTERVAL | NFT_SET_TIMEOUT |
NFT_SET_MAP | NFT_SET_EVAL |
- NFT_SET_OBJECT | NFT_SET_CONCAT))
+ NFT_SET_OBJECT | NFT_SET_CONCAT | NFT_SET_EXPR))
return -EOPNOTSUPP;
/* Only one of these operations is supported */
if ((flags & (NFT_SET_MAP | NFT_SET_OBJECT)) ==
@@ -4304,6 +4304,10 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
struct nlattr *tmp;
int left;
+ if (!(flags & NFT_SET_EXPR)) {
+ err = -EINVAL;
+ goto err_set_alloc_name;
+ }
i = 0;
nla_for_each_nested(tmp, nla[NFTA_SET_EXPRESSIONS], left) {
if (i == NFT_SET_EXPR_MAX) {
diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c
index f35df221a633..0b053f75cd60 100644
--- a/net/netfilter/nft_dynset.c
+++ b/net/netfilter/nft_dynset.c
@@ -19,6 +19,7 @@ struct nft_dynset {
enum nft_registers sreg_key:8;
enum nft_registers sreg_data:8;
bool invert;
+ bool expr;
u8 num_exprs;
u64 timeout;
struct nft_expr *expr_array[NFT_SET_EXPR_MAX];
@@ -175,11 +176,12 @@ static int nft_dynset_init(const struct nft_ctx *ctx,
if (tb[NFTA_DYNSET_FLAGS]) {
u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
-
- if (flags & ~NFT_DYNSET_F_INV)
+ if (flags & ~(NFT_DYNSET_F_INV | NFT_DYNSET_F_EXPR))
return -EOPNOTSUPP;
if (flags & NFT_DYNSET_F_INV)
priv->invert = true;
+ if (flags & NFT_DYNSET_F_EXPR)
+ priv->expr = true;
}
set = nft_set_lookup_global(ctx->net, ctx->table,
@@ -261,6 +263,9 @@ static int nft_dynset_init(const struct nft_ctx *ctx,
struct nlattr *tmp;
int left;
+ if (!priv->expr)
+ return -EINVAL;
+
i = 0;
nla_for_each_nested(tmp, tb[NFTA_DYNSET_EXPRESSIONS], left) {
if (i == NFT_SET_EXPR_MAX) {