[Dnsmasq-discuss] SO_REUSEPORT and SO_REUSEADDR

[Tomas Hozza]

Hi.

In Fedora I had recently a couple of Bugs because of dnsmasq conflicting with
ISC DHCP because of dnsmasq binding to ANY_ADDR for DHCPv4 socket.
dnsmasq uses SO_REUSEPORT if the system supports it instead of
SO_REUSEADDR.

Since ISC DHCP uses always SO_REUSEADDR for DHCPv4 socket, it conflicted
with dnsmasq that used SO_REUSEPORT. However I noticed that ISC DHCP sets
both SO_REUSEPORT and SO_REUSEADDR for DHCPv6 socket (of course if both are
supported by the system).

I'm wondering if dnsmasq could do the same thing to improve its interoperability
with other (possibly older) daemons. Of course only if both socket options
are supported. I'm not sure what downsides this approach would have, but AFIK
it should not be a problem.

Regards,

Tomas Hozza