As of unbound 1.12.0 the AF_NETLINK is required during process startup
in some configurations. Without this patch the process startup
terminates as follows:
[1607371992] unbound[10523:0] error: failed to list interfaces: getifaddrs: Address family not supported by protocol
[1607371992] unbound[10523:0] fatal error: could not open ports
The requirement was first introduced [0] and only after the release
fixed in the upstream unit files [1]. The upstream fix is the same fix
we are applying to our unit configuration.
[0] - Similar to NSD PR#113, implement that interface names can be used, · NLnetLabs/unbound@f6a527c · GitHub
[1] Add AF_NETLINK to set of allowed socket address families by dvzrv · Pull Request #351 · NLnetLabs/unbound · GitHub