[PATCH nf 1/2] netfilter: nf_tables: report EOPNOTSUPP on unsupported flags/object type

[PATCH nf 1/2] netfilter: nf_tables: report EOPNOTSUPP on unsupported flags/object type

[Pablo Neira Ayuso]

EINVAL should be used for malformed netlink messages. New userspace and
old kernels might easily result in EINVAL when exercising new set
features, which is misleading.

Fixes: 8aeff920dcc9 ("netfilter: nf_tables: add stateful object reference to set elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index f91e96d8de05..21cbde6ecee3 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3963,7 +3963,7 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 			      NFT_SET_INTERVAL | NFT_SET_TIMEOUT |
 			      NFT_SET_MAP | NFT_SET_EVAL |
 			      NFT_SET_OBJECT))
-			return -EINVAL;
+			return -EOPNOTSUPP;
 		/* Only one of these operations is supported */
 		if ((flags & (NFT_SET_MAP | NFT_SET_OBJECT)) ==
 			     (NFT_SET_MAP | NFT_SET_OBJECT))
@@ -4001,7 +4001,7 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
 		objtype = ntohl(nla_get_be32(nla[NFTA_SET_OBJ_TYPE]));
 		if (objtype == NFT_OBJECT_UNSPEC ||
 		    objtype > NFT_OBJECT_MAX)
-			return -EINVAL;
+			return -EOPNOTSUPP;
 	} else if (flags & NFT_SET_OBJECT)
 		return -EINVAL;
 	else
-- 
2.11.0

[PATCH nf 2/2] netfilter: nf_tables: reintroduce the NFT_SET_CONCAT flag

[Pablo Neira Ayuso]

Stefano originally proposed to introduce this flag, users hit EOPNOTSUPP
in new binaries with old kernels when defining a set with ranges in
a concatenation.

Fixes: f3a2181e16f1 ("netfilter: nf_tables: Support for sets with multiple ranged fields")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/uapi/linux/netfilter/nf_tables.h | 2 ++
 net/netfilter/nf_tables_api.c            | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index 30f2a87270dc..4565456c0ef4 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -276,6 +276,7 @@ enum nft_rule_compat_attributes {
  * @NFT_SET_TIMEOUT: set uses timeouts
  * @NFT_SET_EVAL: set can be updated from the evaluation path
  * @NFT_SET_OBJECT: set contains stateful objects
+ * @NFT_SET_CONCAT: set contains a concatenation
  */
 enum nft_set_flags {
 	NFT_SET_ANONYMOUS		= 0x1,
@@ -285,6 +286,7 @@ enum nft_set_flags {
 	NFT_SET_TIMEOUT			= 0x10,
 	NFT_SET_EVAL			= 0x20,
 	NFT_SET_OBJECT			= 0x40,
+	NFT_SET_CONCAT			= 0x80,
 };
 
 /**
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 21cbde6ecee3..9adfbc7e8ae7 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3962,7 +3962,7 @@ 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_OBJECT | NFT_SET_CONCAT))
 			return -EOPNOTSUPP;
 		/* Only one of these operations is supported */
 		if ((flags & (NFT_SET_MAP | NFT_SET_OBJECT)) ==
-- 
2.11.0

Re: [PATCH nf 2/2] netfilter: nf_tables: reintroduce the NFT_SET_CONCAT flag

[Stefano Brivio]

On Tue,  7 Apr 2020 17:36:53 +0200
Pablo Neira Ayuso <pablo@netfilter.org> wrote:

> Stefano originally proposed to introduce this flag, users hit EOPNOTSUPP
> in new binaries with old kernels when defining a set with ranges in
> a concatenation.
> 
> Fixes: f3a2181e16f1 ("netfilter: nf_tables: Support for sets with multiple ranged fields")
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Reviewed-by: Stefano Brivio <sbrivio@redhat.com>

-- 
Stefano