Re: [nft PATCH 6/7] libnftables: Provide an API for include path handling

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

On Fri, Oct 20, 2017 at 07:16:20PM +0200, Phil Sutter wrote:
> Hi,
> 
> On Fri, Oct 20, 2017 at 02:17:00PM +0200, Pablo Neira Ayuso wrote:
> > On Thu, Oct 19, 2017 at 10:18:46AM +0200, Phil Sutter wrote:
> [...]
> > > +int nft_ctx_add_include_path(struct nft_ctx *ctx, const char *path)
> > 
> > Do we want to accept runtime addition/removal of include paths?
> 
> Not necessarily, but src/main.c does just that: It calls nft_ctx_new()
> first, then adds include paths as it parses them from command line.

So it's more like a one time call to set up the include path, right?
So I think semantically this is just another setter. This _add_ name
made me think you can keep adding including path one after another
anytime.

> > I mean, I would just make it nft_ctx_set_include_path(), then add an
> > unsetter, so we simplify this.
> 
> The counterpart to nft_ctx_add_include_path() is
> nft_ctx_clear_include_paths(), which just drops all the previously set
> ones. Does that meet your understanding of an unsetter, or am I missing
> something?

Do we have a usecase for nft_ctx_clear_include_paths(). If we don't
- I don't see any at least from my side - I'd prefer, to keep it back.

> The reason why this patch is a bit more complicated is because I wanted
> to get rid of the hard upper limit of include paths to avoid introducing
> a getter for number of set include paths or to make it necessary for
> applications (read: src/main.c) to check what return code
> nft_ctx_add_include_path() returned to print a reasonable error message.

I'm fine with removing the upper limit, but that is a different thing.
My only concerns are related to the API we provide to set include
paths.