Re: Alt-Svc + Proxy Pac

[Patrick McManus <[e-mail]>]

I agree with martin's suggested resolution.

fwiw the original netscape documentation says that the host argument is the
host extracted from the url for convenience (what else could it say?). I
think making existing pacs do indeterminate things based on which argument
they are looking at is a mistake.

separately - there has been some talk about standardizing modern pac - One
thing we could do in that space is make the list of alternatives available
to the PAC file though a separate variable, argument, or helper function.
The PAC is really about routing afterall. It could not only select a proxy
with that information, it could also implement alternate selection (through
some new return mechanism) and return DIRECT.

-P


On Fri, Apr 3, 2015 at 12:51 PM, Martin Thomson <[e-mail]>
wrote:

> https://github.com/httpwg/http-extensions/issues/62
>
> On 3 April 2015 at 09:50, Martin Thomson <[e-mail]> wrote:
> > Good question.
> >
> > I think that you put the original requested URL in and let the proxy
> > worry about alt-svc compliance.
> >
> > The proxy is your overriding alternative.  That matches the logic in
> > the case where the proxy.pac isn't present and you just have a
> > hard-coded proxy that you send all requests to.
> >
> > Now, if the proxy.pac suggests that direct is acceptable, I think that
> > makes it OK to (try to) use the alternative.  If you think of
> > proxy.pac as a first level alternative selector, and alt-svc as a
> > second-level one, I think that works.
> >
> >
> >
> > On 3 April 2015 at 07:35, Ryan Hamilton <[e-mail]> wrote:
> >> Howdy Folks,
> >>
> >> I'm curious how Alt-Svc is expect to work with Proxy PAC files.
> Consider the
> >> scenario where http://www.example.com/ has an Alt-Svc that specified
> http/2
> >> on mail.example.com:443. When the browser decides to make an http/2
> (over
> >> TLS) connection to mail.example.com, on behalf of
> http://www.example.com,
> >> what URL and host should the browser pass to the PAC file's
> >> FindProxyForURL() method?
> >>
> >> I can argue both cases.
> >>
> >> * It should pass in the requested url (http://www.example.com/)
> because that
> >> is the URL being requested. There is no other URL.
> >> * It should pass in a pseudo url (https://mail.exmaple.com/) because,
> for
> >> example, access to mail.example.com may well requires use of a proxy to
> >> access. By passing in the request URL, the PAC file does not have the
> >> opportunity to send the connection to the correct proxy.
> >>
> >> Thoughts?
> >>
> >> Cheers,
> >>
> >> Ryan
> >>
>
>