Re: [PATCH net-next v3 3/4] tools/net/ynl: Handle acks that use req_value

From: Jakub Kicinski <kuba@kernel.org>
To: Donald Hunter <donald.hunter@gmail.com>
Cc: netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Paolo Abeni <pabeni@redhat.com>, Jiri Pirko <jiri@resnulli.us>,
	Jacob Keller <jacob.e.keller@intel.com>,
	Pablo Neira Ayuso <pablo@netfilter.org>,
	Jozsef Kadlecsik <kadlec@netfilter.org>,
	netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
	donald.hunter@redhat.com
Subject: Re: [PATCH net-next v3 3/4] tools/net/ynl: Handle acks that use req_value
Date: Tue, 16 Apr 2024 19:10:16 -0700	[thread overview]
Message-ID: <20240416191016.5072e144@kernel.org> (raw)
In-Reply-To: <20240416193215.8259-4-donald.hunter@gmail.com>

On Tue, 16 Apr 2024 20:32:14 +0100 Donald Hunter wrote:
> The nfnetlink family uses the directional op model but errors get
> reported using the request value instead of the reply value.

What's an error in this case ? "Normal" errors come via NLMSG_ERROR

> diff --git a/tools/net/ynl/lib/nlspec.py b/tools/net/ynl/lib/nlspec.py
> index 6d08ab9e213f..04085bc6365e 100644
> --- a/tools/net/ynl/lib/nlspec.py
> +++ b/tools/net/ynl/lib/nlspec.py
> @@ -567,6 +567,18 @@ class SpecFamily(SpecElement):
>            return op
>        return None
>  
> +    def get_op_by_value(self, value):
> +        """
> +        For a given operation value, look up operation spec. Search
> +        by response value first then fall back to request value. This
> +        is required for handling failure cases.

Looks like we're only going to need it in NetlinkProtocol, so that's
fine. But let's somehow call out that this is a bit of a hack, so that
people don't feel like this is the more correct way of finding the op
than direct access to rsp_by_value[].