It's not easy to configure Samba in standard DD-WRT because, by default, the /etc folder is read-only. So before starting, please set a writable /etc. Also, DD-WRT does have a Samba3 built in the firmware and it works just fine, you're just not able to configure it fully. In this guide, you'll be guided through the whole process to set up a password protected samba share with custom usernames and passwords.
