Re: [nftables PATCH] json: support element output

[Phil Sutter <phil@nwl.cc>]

Hi Georg,

Sorry for the late reply, I missed your mail last year and am still
recovering from the "big reset". ;)

On Wed, Dec 03, 2025 at 02:17:36PM +0100, Georg Pfuetzenreuter wrote:
> From: Georg Pfuetzenreuter <georg.pfuetzenreuter@suse.com>
> 
> JSON was skipped for `get element` operations. Resolve this by
> introducing JSON output handling for set elements - the structure is
> kept close to what's already implemented for `list set`.
> 
> Signed-off-by: Georg Pfuetzenreuter <georg.pfuetzenreuter@suse.com>

Patch looks fine apart from:

[...]
> +int do_get_setelems_json(struct netlink_ctx *ctx, struct cmd *cmd, bool reset)
> +{
> +	struct set *set, *new_set;
> +	struct expr *init;
> +	json_t *root = json_array();
> +	int err;

Please stick to reverse christmas tree notation here, i.e. put the
json_t *root on top of the list.

> +
> +	set = cmd->elem.set;
> +
> +	if (set_is_non_concat_range(set))
> +		init = get_set_intervals(set, cmd->expr);
> +	else
> +		init = cmd->expr;
> +
> +	new_set = set_clone(set);
> +
> +	json_array_insert_new(root, 0, generate_json_metainfo());
> +
> +	err = netlink_get_setelem(ctx, &cmd->handle, &cmd->location,
> +				  cmd->elem.set, new_set, init, reset);
> +	if (err >= 0)
> +		json_array_append_new(root, set_print_json(&ctx->nft->output, new_set));

This line exceeds 80 columns, no?

Also, could you please add a test case? A simple one in
tests/shell/testcases/json/ to make sure 'nft -j get element' output is
as expected should be fine.

Thanks, Phil