corenet_udp_bind_generic_port()
For the record, the reason the randomization is a weakness in DNS
protocol:
http://linuxsysadminblog.com/2008/12/how-to-check-if-your-dns-server-impl...
or
https://www.dns-oarc.net/oarc/services/porttest
In the core policy, I see djbdns having the very same macro.
Surprisingly, bind does not have it (or I missed it).
--
Later,
Lukas #lzap Zapletal