Re: [PATCH] vsprintf: do not append unset Scope ID to IPv6

From: Jason A. Donenfeld
Date: Wed Feb 03 2016 - 16:14:30 EST


On Wed, Feb 3, 2016 at 10:07 PM, Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote:
> I don't see an "issue" here. I.e. if the developer requested to append 's'
> to the specifier, then it's expected to dump what is in the scope id, even
> if that is 0 meaning "unset" scope.
>
> It would be principle of least surprise -- I could imagine if not dumped,
> then a developer would check the source code to find out whether he did a
> mistake or it's expected behavior, just to make sure. That's what I would
> do probably.

Showing something that's "unset" seems counter-intuitive.

The idea here is to be able to printk a sockaddr_in6, and have it show
something that looks like what the user would naturally pass to
getaddrinfo(3), which is entirely complete.

However, I could be convinced that this kind of behavior belongs in
it's own flag. Maybe I'll cook up a flag for that instead.

>
> Is this causing a _real_ issue somewhere (I couldn't parse one out of your
> commit message other than 'it would be nice to have')?

Nice to have.