Bug#558125: epiphany-browser - Caches the decision to use ipv6 over network topology changes

[Simon Paillard]

On Sun, Mar 20, 2011 at 03:44:28PM -0300, Gustavo Noronha Silva wrote:
> On Sat, 2011-03-19 at 01:41 +0100, Simon Paillard wrote:
> > > > This is likely a problem in libsoup, or on GResolver. I'll ask Dan
> > > > Winship.
> > >
> > > Any luck?
> 
> No, sorry, I dropped the ball on this.
> 
> > As I met this again in the context of Debian WWW mirrors (one mirror removed
> > from the DNS rotation with little enough TTL), but epiphany still tried to
> > connect to an outdated IP.
> > 
> > So basically it behaves as if we had a infinite TTL: breaking redundancy, load
> > balancing..
> > 
> > I'm not used enough to gdb, so cannot locate/provide patch, but here are some
> > results/conclusions (on squeeze and sid):
> > 
> > - unless a DNS request fails for a host, then further requests for that uri
> >   (example on force refresh) will be performed against 0x00 host (epiphany
> >   really wants to know about root servers ?) 
> 
> I didn't follow here, can you detail a bit more how you reached this
> conclusion, and what exactly happens?

- Load any page (e.g. www.debian.org or even a 404, like
  http://people.debian.org/~spaillard/test.html).
- Run wireshark/tshark and follow DNS requests:
  "(dns.flags.response == 0) && (dns.qry.type == 0x0001)"
- Force a reload of the page -> requests perfomered against null name, 0x00 in
  DNS, while it should be www.debian.org.
 
> > - *each time the mouse is moved*, a DNS request is performed for the uri for the
> >   DOM object (so 0x00 for the background/already resolved, host for the link) !!
> 
> This is WebKit pre-resolving DNS, but I still don't really understand
> the 0x00 reference. In any case, Epiphany doesn't deal with network
> directly, that is libsoup's domain, so I think we should reassign it
> there, and perhaps get some testing on experimental's libsoup to see if
> there's been any improvement. Could anyone help with this?

This is easily reproducible (not tested in experimental yet).
I don't know which is responsible to trigger this mecanism, but this is
triggered everytime the mouse is moved, even when the object is kept the same.
Is this under epiphany reponsability to cache results and not request them
again and again to libsoup ?

-- 
Simon Paillard