I know nothing about SMB, but I have done this exact thing with perl before:-

The connection to VMS was made using ftp. Because the code was written nine years ago, the ftp was managed by a custom module rather than the CPAN Ftp module.

The files from the SMSC were left initially in VMS format on unix, complete with the ';' and version number, but any binary files were decoded with a C program before being processed logically with perl (the system had to deal with a variety of traffic types).

This may not be a direct answer to your question, but I hope it sheds some light on how an existing mobile usage filter written in perl was laid out - and one which has been successful for a long time.