About SAMBA with multiuser-Support. Tomato supports only one user auth. If you want multiuser you can rgant permission over IP. In custom configuration add share:

[share1]

path = /tmp/mnt/sda1/share1

writable = yes

force user = root

comment =

hosts allow = 192.168.1.2



where:

- share1 is a share name

- path is a path to shared directory

- hosts allow is ip address(es) of allowed user(s).