sandbox.sh

#!/bin/bash
 
# Mount a source directory or fs type $i in destination mount point $j 
# using options $k
#
#     i               j                  k
mdirs=( 
  "unionfs"   "/opt/unionfs"         "-t unionfs -o dirs=/opt/sandbox:/=ro"
  "/dev"      "/opt/unionfs/dev"     "--bind"
  "devpts"    "/opt/unionfs/dev/pts" "-t devpts"
  "shm"       "/opt/unionfs/dev/shm" "-t tmpfs"
  "sysfs"     "/opt/unionfs/sys"     "-t sysfs"
  "proc"      "/opt/unionfs/proc"    "-t proc"
  "/tmp"      "/opt/unionfs/tmp"     "--bind"
  "/dev/sda6" "/opt/unionfs/opt"     "-t ext3"
      )
 
mount_unionfs()
{
    mdir_size=${#mdirs[*]}
 
    i=0; j=1; k=2
    while [ "$i" -lt "$mdir_size" ]; do
        if [ -z "$(mount | grep -w ${mdirs[$j]})" ]; then
            echo "Mounting ${mdirs[$j]}"
            sudo /bin/mount ${mdirs[$k]} ${mdirs[$i]} ${mdirs[$j]}
        fi
        i=$((i + 3)); j=$((j + 3)); k=$((k + 3))
    done
}
 
umount_unionfs()
{
    mdir_size=${#mdirs[*]}
 
    j=$((mdir_size - 2))
    while [ "$j" -gt "0" ]; do
        if [ -n "$(mount | grep -w ${mdirs[$j]})" ]; then
            echo "Umounting ${mdirs[$j]}"
            sudo /bin/umount ${mdirs[$j]} 2> /dev/null
        fi
        j=$((j - 3))
    done
}
 
mount_unionfs
 
sudo /usr/sbin/chroot /opt/unionfs /bin/su --shell /bin/bash --login $USER
 
umount_unionfs