On Mon, Oct 29, 2018 at 01:29:32PM +0100, Phil Sutter wrote:
> Hi,
>
> On Mon, Oct 29, 2018 at 12:33:39PM +0100, Pablo Neira Ayuso wrote:
> > Add NFT_CTX_OUTPUT_JSON flag and display output in json format.
> >
> > Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
> [...]
> > diff --git a/doc/libnftables.adoc b/doc/libnftables.adoc
> > index 8b7aee9af134..5a3562c3266c 100644
> > --- a/doc/libnftables.adoc
> > +++ b/doc/libnftables.adoc
> [...]
> > @@ -105,6 +103,8 @@ NFT_CTX_OUTPUT_STATELESS::
> > If stateless output has been requested then stateful data is not
> > printed. Stateful data refers to those objects that carry run-time data,
> > eg. the *counter* statement holds packet and byte counter values, making it
> > stateful.
> > NFT_CTX_OUTPUT_HANDLE::
> > Upon insertion into the ruleset, some elements are assigned a unique
> > handle for identification purposes. For example, when deleting a table or
> > chain, it may be identified either by name or handle. Rules on the other
> > hand must be deleted by handle because there is no other way to uniquely
> > identify them. These functions allow to control whether ruleset listings
> > should include handles or not.
> > +NFT_CTX_OUTPUT_JSON::
> > + If enabled at compile-time, libnftables accepts input in JSON format
> > and is able to print output in JSON format as well. See
> > *libnftables-json*(5) for a description of the supported schema. These
> > functions control JSON output format, input is auto-detected.
>
> s/These functions control/This flag controls/
Done. Thanks!
> [...]
> > diff --git a/src/libnftables.c b/src/libnftables.c
> > index 6dc1be3d5ef8..ff7a53d22ba4 100644
> > --- a/src/libnftables.c
> > +++ b/src/libnftables.c
> > @@ -352,22 +352,6 @@ void nft_ctx_output_set_echo(struct nft_ctx *ctx, bool
> > val)
> > ctx->output.echo = val;
> > }
> >
> > -bool nft_ctx_output_get_json(struct nft_ctx *ctx)
> > -{
> > -#ifdef HAVE_LIBJANSSON
> > - return ctx->output.json;
> > -#else
> > - return false;
> > -#endif
> > -}
> > -
> > -void nft_ctx_output_set_json(struct nft_ctx *ctx, bool val)
> > -{
> > -#ifdef HAVE_LIBJANSSON
> > - ctx->output.json = val;
> > -#endif
> > -}
> > -
>
> In above functions, I guarded output.json setting by whether JSON
> support was built-in.
I'm going to do the same here but...
> [...]
> > diff --git a/src/main.c b/src/main.c
> > index 97b8746608a7..8ea07641734d 100644
> > --- a/src/main.c
> > +++ b/src/main.c
> > @@ -271,7 +271,7 @@ int main(int argc, char * const *argv)
> > nft_ctx_output_set_echo(nft, true);
> > break;
> > case OPT_JSON:
> > - nft_ctx_output_set_json(nft, true);
> > + output_flags |= NFT_CTX_OUTPUT_JSON;
> > break;
> > case OPT_INVALID:
> > exit(EXIT_FAILURE);
>
> Maybe we should do the same here? Otherwise if JSON wasn't enabled at
> compile-time, calling 'nft -j' leads to no output at all. (Not sure if
> silently falling back to standard output formatting is a better choice
> after all. :)
... I think failing here is json support is not built-in is the way to
go - instead of silently ignoring it.
Would you mind send a follow up patch to change this behaviour? :-)
Thanks!
