Fixes to ypbind:
- Correctly report the fact that we've bound to a new server when
logging the 'server OK' message.
- Report 'server not responding' just once instead of every
5 seconds while searching for a new server. (Prevents overstuffing
the syslog.)
- Apply patch from Sebstian Strollo to implement '-s' (secure) flag.
ypbind will reject connections from servers that do not originate
from a reserved TCP port.
- Apply patch from Sebastian Strollo to detect when a YP server has
crashed and come back up on a different port number.
The existing ypbind exhibits some truly anti-social behavior. After
initially establishing a binding with an NIS server, the following events
take place:
- ypbind waits for 60 seconds before trying to broadcast a ping again
- after the 60 seconds expires, ypbind sends out broadcasts every 5 seconds
come hell or high water.
These broadcasts travel far and wide, even to NIS servers in other domains
which dutifully log the packets even though they don't respond to them.
This leads to lots of unnecessary traffic and bloated log files.
This behavior has been fixed/changed. Here's what happens now:
- We still broadcast every 5 seconds at startup, just like before.
- Once bound, we send out packets once every 60 seconds to the server
we're bound to AND NO ONE ELSE.
- If we fail to receive a reply from our server within FAIL_THRESHOLD
seconds, we assume our server has croaked and go back to broadcasting
everywhere every 5 seconds again until somebody answers. FAIL_THRESHOLD
is currently set to 20 seconds.
Other fixes/improvements:
- ypbind now logs 'server not responding' and 'server OK' messages where
appropriate.
Thanks to Thomas Graichen <graichen@omega.physik.fu-berlin.de> for
reporting the problem and guilt-tripping me into fixing it. :)
