OSPF generate default route

[Slawa Olhovchenkov]

I have configuration problem: how I can generate default route in OSPF
area?

Generate, not redistribute from static kernel route or other routing
protocol.

Generate, not installed into kernel routeng table.

Same as for Cisco 'default-information originate always'.

Next question: conditional advertise default route (for example -- if
present announce in BGP to some network).