You can still run a cifs setup and map to the c$ and etc$ shares on a controller without a CIFS license. We use it for administration all of the time. You only need the license if you are serving up data with CIFS, I beleive. That would be easier than FTP.
I apologize for that. For some reason, for us, we can do this even though CIFS is not licensed. I assumed that is the case for everyone. I think in our case we re licensed for FCP, so we get some cifs functionality as a result.
You need to add passwd entries into the /etc/passwd file to get FTP access. The trick is generating the password. Aborzenkov listed the most likely solution, which is to use CIFS passwd. Since you don't have CIFS, you can't use that. Another option (and probably your ONLY option) is below:
For UNIX operating systems, a normal UNIX crypt(3) password entry can be used in the NetApp filer's /etc/passwd file. This can be done using the filer's wrfile command to rewrite the /etc/passwd file. Note that without an NFS or CIFS license, the only way to manage /etc files would be through telnet (wrfile/rdfile) or FTP.
I would do this:
Add a new passwd entry in the file for your FTP user.
Generate the password using the crypt function from one of your linux/unix workstations in your environment.