pkg install samba44
sysrc samba_server_enable="YES"

/usr/local/etc/smb4.conf

[global]
workgroup = WORKGROUP
server string = CSNA Server
netbios name = csna
wins support = Yes
security = user
passdb backend = tdbsam

[public]
path = /home/public
writable  = yes
browsable = yes
read only = no
guest ok = yes
public = yes
create mask = 0644
directory mask = 0755

smbpasswd -a CSNA2016

user has all permission on his/her own file, but can not delete others.

mkdir /home/public
chmod 3777 /home/public

service samba_server start