From aaa31047a6d25da0fa101da1ed544e1247949b40 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 27 Apr 2021 18:05:55 +0200 Subject: netfilter: nftables: add catch-all set element support This patch extends the set infrastructure to add a special catch-all set element. If the lookup fails to find an element (or range) in the set, then the catch-all element is selected. Users can specify a mapping, expression(s) and timeout to be attached to the catch-all element. This patch adds a catchall list to the set, this list might contain more than one single catch-all element (e.g. in case that the catch-all element is removed and a new one is added in the same transaction). However, most of the time, there will be either one element or no elements at all in this list. The catch-all element is identified via NFT_SET_ELEM_CATCHALL flag and such special element has no NFTA_SET_ELEM_KEY attribute. There is a new nft_set_elem_catchall object that stores a reference to the dummy catch-all element (catchall->elem) whose layout is the same of the set element type to reuse the existing set element codebase. The set size does not apply to the catch-all element, users can define a catch-all element even if the set is full. The check for valid set element flags hava been updates to report EOPNOTSUPP in case userspace requests flags that are not supported when using new userspace nftables and old kernel. Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter/nf_tables.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 467365ed59a7..1fb4ca18ffbb 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -398,9 +398,11 @@ enum nft_set_attributes { * enum nft_set_elem_flags - nf_tables set element flags * * @NFT_SET_ELEM_INTERVAL_END: element ends the previous interval + * @NFT_SET_ELEM_CATCHALL: special catch-all element */ enum nft_set_elem_flags { NFT_SET_ELEM_INTERVAL_END = 0x1, + NFT_SET_ELEM_CATCHALL = 0x2, }; /** -- cgit v1.2.3