Re: [iptables PATCH 3/3] libxtables: Register multiple extensions in ascending order

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Wed, Sep 23, 2020 at 12:53:41AM +0200, Phil Sutter wrote:
> The newly introduced ordered insert algorithm in
> xtables_register_{match,target}() works best if extensions of same name
> are passed in ascending revisions. Since this is the case in about all
> extensions' arrays, iterate over them from beginning to end.

This patch should come first in the series, my understanding is that
1/3 assumes that extensions are registered from lower to higher
revision number.

> Signed-off-by: Phil Sutter <phil@nwl.cc>
> ---
>  libxtables/xtables.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/libxtables/xtables.c b/libxtables/xtables.c
> index de74d361a53af..90b1195c45a58 100644
> --- a/libxtables/xtables.c
> +++ b/libxtables/xtables.c
> @@ -1139,9 +1139,10 @@ static bool xtables_fully_register_pending_match(struct xtables_match *me,
>  
>  void xtables_register_matches(struct xtables_match *match, unsigned int n)
>  {
> -	do {
> -		xtables_register_match(&match[--n]);
> -	} while (n > 0);
> +	int i;
> +
> +	for (i = 0; i < n; i++)
> +		xtables_register_match(&match[i]);
>  }
>  
>  void xtables_register_target(struct xtables_target *me)
> @@ -1264,9 +1265,10 @@ static bool xtables_fully_register_pending_target(struct xtables_target *me,
>  
>  void xtables_register_targets(struct xtables_target *target, unsigned int n)
>  {
> -	do {
> -		xtables_register_target(&target[--n]);
> -	} while (n > 0);
> +	int i;
> +
> +	for (i = 0; i < n; i++)
> +		xtables_register_target(&target[i]);
>  }
>  
>  /* receives a list of xtables_rule_match, release them */
> -- 
> 2.28.0
>