Background. That CUPS is a more security-aware printing system than traditional ones does not by default allow a user to send deliberate (possibly binary) data to printing devices. This could be easily abused to launch a “Denial of Service” attack on your printer(s), causing at least the loss of a lot of paper and ink. “Unknown” data are tagged by CUPS as MIME type: application/octet-stream and not allowed to go to the printer. By default, you can only send other (known) MIME types “raw.” Sending data “raw” means that CUPS does not try to convert them and passes them to the printer untouched.

This is all you need to know to get the CUPS/Samba combo printing “raw” files prepared by Windows clients, which have vendor drivers locally installed. If you are not interested in background information about more advanced CUPS/Samba printing, simply skip the remaining sections of this chapter.