In some cases booting firware requires multiple IPv6 addresses leased
from DHCP. Dnsmasq offers the same address to different IAIDs requests.
The first gets it successfully, but remaining requests would be denied
with address in use error. Change behaviour and supply alternative
address from the same range, just like Rapid Commit DHCP option allows.
Reuse the same code.
Resolves: rhbz#2002871
Similar functionality was implemented in upstream release 2.86 as part
of bigger optimization. While it should have introduce better
performance on bigger domain filter list, it caused several regressions
including crashes.
This is attempt to make similar functionality in different way, without
so heavy change to basic system. It instead adds new structure for each
unique domain, which tracks last tried server for a given domain. It
makes the same algorithm used for domain-less servers, such as those
read from /etc/resolv.conf. But uses that also for servers forwarding
only for subdomains.
It might slightly increase used memory on high number of local=/example/
or server=/example/::1.
Resolves: rhbz#2047510
Upstream has merged patch dnsmasq-2.81-rh1834454.patch slightly
different way, but it is applied anyway. SIOCGSTAMP was fixed by
upstream different way.
Resolves: rhbz#1978728
