sshd_config

Match User user1

ChrootDirectory /dir1
ForceCommand internal-sftp
AllowTcpForwarding no
X11Forwarding      no

 

Create a user in the passwd file with the home dir of the above and /bin/false for shell.

 

chmod -R 755 /dir1

cd dir1; chmod -R 775 *

chown -R root:dba /dir1