- Make the child process reaper signal-driven. (Previously, we called reaper()
once a second each time we went through the select() loop. This was
convenient, but inefficient.)
- Increase main select() timeout from 1 second to 60 seconds and use
this as the ping timer instead of using timestamps in the _dom_binding
structure. This nd the reaper() change noted above makes ypbind a little
less CPU-intensive.
- Don't flag EINTR's from select() as errors since they will happen as a
result of incoming SIGCHLD's interrupting select().
- Prevent possible resource hogging. Currently we malloc() memory
each time a user process asks us to establish a binding for a domain,
but we never free it. This could lead to serious memory leakage if a
'clever' user did something like ask ypwhich to check the bindings
for domains 0.0.0.0.0.0.0.0.0.0 through 9.9.9.9.9.9.9.9.9.9 inclusive.
(This would also make a mess out of the /var/yp/binding directory.)
We now avoid this silliness by a) limiting the maximum number of
simultaneous bindings we can manage to 200, and b) free()ing _dom_binding
structures of secondary domains whose servers have stopped responding.
We unlink the /var/yp/binding/domain.vers files for the free()ed
domains too.
(This is safe to do since a client can prod us into reestablishing the
binding, at which time we'll simply allocate a new _dom_binding structure
for it.)
We keep count of the total number of domains. If asked to
allocate more than the maximum, we return an error. I have yet to hear
of anybody needing 200 simultaneous NIS bindings, so this should be
enough. (I chose the number 200 arbitrarily. It can be increased if need
be.)
- Changed "server not responding"/"server OK" messages to display server
IP addresses again since it looks spiffier.
- Use daemon() to daemonify ourselves,
- Added a SIGTERM handler that removes all binding files and unregisters
the ypbind service from the portmapper when a SIGTERM in received.
- The comment 'blow away everything in BINDINGDIR' has no associated code.
Give it some: clean out /var/yp/binding at startup (if it exists).
This completes my ypbind wishlist. Barring bug fixes, I shouldn't need to
go poking around in here anymore. (Of course, this means I can start
working on my ypserv whishlist now... :)
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