Subject: Re: [PATCH net-next 01/14] netfilter: nf_tables: fix set size with rbtree backend

From: Simon Horman <[email-masked]>
Date: Fri, 17 Jan 2025 10:49:57 +0000

On Thu, Jan 16, 2025 at 06:18:49PM +0100, Pablo Neira Ayuso wrote:
> The existing rbtree implementation uses singleton elements to represent
> ranges, however, userspace provides a set size according to the number
> of ranges in the set.
> 
> Adjust provided userspace set size to the number of singleton elements
> in the kernel by multiplying the range by two.
> 
> Check if the no-match all-zero element is already in the set, in such
> case release one slot in the set size.
> 
> Fixes: 0ed6389c483d ("netfilter: nf_tables: rename set implementations")
> Signed-off-by: Pablo Neira Ayuso <[email-masked]>
> ---
>  include/net/netfilter/nf_tables.h |  3 ++
>  net/netfilter/nf_tables_api.c     | 49 +++++++++++++++++++++++++++++--
>  net/netfilter/nft_set_rbtree.c    | 43 +++++++++++++++++++++++++++
>  3 files changed, 93 insertions(+), 2 deletions(-)
> 
> diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
> index 0027beca5cd5..7dcea247f853 100644
> --- a/include/net/netfilter/nf_tables.h
> +++ b/include/net/netfilter/nf_tables.h
> @@ -495,6 +495,9 @@ struct nft_set_ops {
>  					       const struct nft_set *set,
>  					       const struct nft_set_elem *elem,
>  					       unsigned int flags);
> +	u32				(*ksize)(u32 size);
> +	u32				(*usize)(u32 size);
> +	u32				(*adjust_maxsize)(const struct nft_set *set);
>  	void				(*commit)(struct nft_set *set);
>  	void				(*abort)(const struct nft_set *set);
>  	u64				(*privsize)(const struct nlattr * const nla[],

Hi Pablo,

As a follow-up could these new fields be added to
the Kernel doc for nft_set_ops?