Re: [BUG] ipv6: all routes share same inetpeer

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mardi 19 juillet 2011 à 11:59 -0700, David Miller a écrit :
> From: Eric Dumazet <eric.dumazet@gmail.com>
> Date: Tue, 19 Jul 2011 20:57:50 +0200
> 
> > Le mardi 19 juillet 2011 à 20:20 +0200, Eric Dumazet a écrit :
> >> Le mardi 19 juillet 2011 à 10:37 -0700, David Miller a écrit :
> >> > From: Eric Dumazet <eric.dumazet@gmail.com>
> >> > Date: Tue, 19 Jul 2011 19:23:49 +0200
> >> > 
> >> > > Maybe you can find the bug before me ?
> >> > 
> >> > I think when we add the route we cow the metrics almost immediately.
> >> > The daddr is, unfortunately, fully prefixed at that point.
> >> 
> >> Yes, we shall provide a second ip6_rt_copy() argument, with the
> >> destination address.
> >> 
> > 
> > Hmm, or maybe just change the dst_copy_metrics(&rt->dst, &ort->dst);
> > call done from ip6_rt_copy(), to avoid doing the COW if not really
> > needed ?
> 
> This is ok if it handles the case where ort's metrics point to
> writable inetpeer memory.

OK but if ort's metrics are writeable we must perform the dst_copy_metrics()
and therefore fill rt6i_dst before ?

My first patch had an issue in rt6_alloc_cow(), line 710, where 
ipv6_addr_equal(&rt->rt6i_dst.addr, daddr) becomes always true.

I guess I can replace it by ipv6_addr_equal(&ort->rt6i_dst.addr, daddr)