Re: WGLC: draft-ietf-appsawg-http-forwarded-02.txt - section 5.1

[Willy Tarreau <[e-mail]>]

Hi Julian,

On Mon, May 14, 2012 at 11:55:34PM +0200, Julian Reschke wrote:
> On 2012-05-14 23:48, Willy Tarreau wrote:
> >...
> >OK in theory but in practice I'm fairly sure we'll see IPv6 addresses
> >sent unquoted because a number of implementations will not have noticed
> >they became mandatory. That's why sometimes widening a character set to
> >better fit what it is supposed to represent makes a lot of sense. This
> >can even be done by slightly extending the grammar :
> >
> >    Forwarded-v = 1#( token "=" ( ipv4 / ipv6 / token / quoted-string ) *( 
> >    ";" ... ) )
> >...
> 
> The downside is that you can't use an off-the-shelf parser component, 
> which I believe is a pretty big downside.
> 
> The HTTP community has been inventing new microsyntaxes for many years, 
> and as far as I can tell, most header field parsers out there are broken 
> beyond belief. We need less of them, even if this means that a few edge 
> cases will be more verbose than necessary.

I see, and indeed this is a good point. Considering the number of times
I've heard "hey, your product sends me commas in IP addresses", it is
certain that people don't understand what they retrieve there.

Cheers,
Willy