[rbldnsd] Warning: possible danger of using rbldnsd, and upcoming data format change

[David Landgren]

Matthew Sullivan wrote:

> 1/ rbldnsd check for and create a lockfile (similar to the old Serial 
> Port lockfiles) - if it's present and locked (exclusive), rbldnsd would 
> not open/update the zonefiles.  If the lockfile was present and locked 
> for exclusive use, then any update program would be made not to update 
> the files.... Of course you could lock the zonefiles themselves for 
> exclusive access and lockout things like rsync.

You have traded one problem for another. Now you have to deal with stale 
locks.

The main problem appears to be idi^H^H^Hpeople who attempt to upload 
data files directly into production. Madness! Inter-system file 
transfers should always use store-and-forward techniques, where the 
receiving end can run sanity checks to make sure the file is correct, 
before moving it over into production.

Having an end-of-file marker on the last line of the file is perfect for 
this.

One should always be wary of encumbering an application with unnecessary 
cruft to solve a (non-)problem that should be addressed by basic rules 
of hygiene.

David