Merge branch 'debian'
[live-boot-grml.git] / scripts / live-helpers
index f67e421..3109356 100644 (file)
@@ -37,6 +37,38 @@ subdevices ()
        echo ${r}
 }
 
+storage_devices()
+{
+       black_listed_devices="${1}"
+       white_listed_devices="${2}"
+
+       for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "loop|ram|fd")
+       do
+               fulldevname=$(sys2dev "${sysblock}")
+
+               if echo "${black_listed_devices}" | grep -qe "\<${fulldevname}\>" || \
+                       [ -n "${white_listed_devices}" ] && \
+                       echo "${white_listed_devices}" | grep -qve "\<${fulldevname}\>"
+               then
+                       # skip this device entirely
+                       continue
+               fi
+
+               for dev in $(subdevices "${sysblock}")
+               do
+                       devname=$(sys2dev "${dev}")
+
+                       if echo "${black_listed_devices}" | grep -qe "\<${devname}\>"
+                       then
+                               # skip this subdevice
+                               continue
+                       else
+                               echo "${devname}"
+                       fi
+               done
+       done
+}
+
 is_supported_fs ()
 {
        fstype="${1}"
@@ -202,7 +234,7 @@ setup_loop ()
                                fi
                        fi
 
-                       if [ 0 -lt "${offset}" ]
+                       if [ -n "${offset}" ] && [ 0 -lt "${offset}" ]
                        then
                                options="${options} -o ${offset}"
                        fi
@@ -279,194 +311,148 @@ try_mount ()
        fi
 }
 
-find_cow_device ()
+open_luks_device ()
 {
-       # Returns a device containing a partition labeled "${pers_label}" or containing a file named the same way
-       #  in the latter case the partition containing the file is left mounted
-       #  if is not in black_listed_devices.
-       #  Additionally, if the white_listed_devices list is non-empty, the
-       #  parent block device of the returned device must be part of this list.
-       pers_label="${1}"
-       cow_backing="/${pers_label}-backing"
-       black_listed_devices="${2}"
-       white_listed_devices="${3}"
-
-       if [ -z "${PERSISTENT_PATH}" ]
+       dev="${1}"
+       name="$(basename ${dev})"
+       opts="--key-file=-"
+       if [ -n "${PERSISTENT_READONLY}" ]
        then
-               pers_fpath=${cow_backing}/${pers_label}
-       else
-               pers_fpath=${cow_backing}/${PERSISTENT_PATH}/${pers_label}
+               opts="${opts} --readonly"
        fi
 
-       for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop | grep -v ram | grep -v fd)
+       load_keymap
+
+       while true
        do
-               fulldevname=$(sys2dev "${sysblock}")
+               /lib/cryptsetup/askpass "Enter passphrase for ${dev}: " | \
+                       /sbin/cryptsetup -T 1 luksOpen ${dev} ${name} ${opts}
 
-               if echo "${black_listed_devices}" | grep -q -w "${fulldevname}"
+               if [ 0 -eq ${?} ]
                then
-                       # skip this device entirely
-                       break
+                       luks_device="/dev/mapper/${name}"
+                       echo ${luks_device}
+                       return 0
                fi
 
-               if [ -n "${white_listed_devices}" ]
+               echo >&6
+               echo -n "There was an error decrypting ${dev} ... Retry? [Y/n] " >&6
+               read answer
+
+               if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
                then
-                       if echo "${white_listed_devices}" | grep -v -q -w "${fulldevname}"
-                       then
-                               # skip this device entirely
-                               break
-                       fi
+                       return 2
                fi
+       done
+}
 
-               for dev in $(subdevices "${sysblock}")
-               do
-                       devname=$(sys2dev "${dev}")
+find_persistent_media ()
+{
+       # Scans devices for overlays and snapshots, and returns a whitespace
+       # separated list of how to use them. Only overlays with a partition
+       # label or file name in ${overlays} are returned, and ditto for
+       # snapshots with labels in ${snapshots}.
+       #
+       # When scanning a LUKS device, the user will be asked to enter the
+       # passphrase; on failure to enter it, or if no persistent partitions
+       # or files were found, the LUKS device is closed.
+       #
+       # For a snapshot file the return value is ${label}=${snapdata}", where
+       # ${snapdata} is the parameter used for try_snap().
+       #
+       # For all other cases (overlay/snapshot partition and overlay file) the
+       # return value is "${label}=${device}", where ${device} a device that
+       # can mount the content. In the case of an overlay file, the device
+       # containing the file will remain mounted as a side-effect.
+       #
+       # No devices in ${black_listed_devices} will be scanned, and if
+       # ${white_list_devices} is non-empty, only devices in it will be
+       # scanned.
+
+       overlays="${1}"
+       snapshots="${2}"
+       black_listed_devices="${3}"
+       white_listed_devices="${4}"
+
+       for dev in $(storage_devices "${black_listed_devices}" "${white_listed_devices}")
+       do
+               luks_device=""
 
-                       if echo "${black_listed_devices}" | grep -q -w "${devname}"
+               # Checking for a luks device
+               if echo ${PERSISTENT_ENCRYPTION} | grep -qe "\<luks\>" && \
+                  /sbin/cryptsetup isLuks ${dev}
+               then
+                       if luks_device=$(open_luks_device "${dev}")
                        then
-                               # skip this subdevice
+                               dev="${luks_device}"
+                       else
+                               # skip $dev since we failed/chose not to open it
                                continue
                        fi
+               elif echo ${PERSISTENT_ENCRYPTION} | grep -qve "\<none\>"
+               then
+                       # skip $dev since we don't allow unencrypted storage
+                       continue
+               fi
 
-                       # Checking for a luks device
-                       if [ "${PERSISTENT_ENCRYPTION}" = "luks" ] && [ -e /sbin/cryptsetup ]
-                       then
-                               if ! modprobe dm-crypt
-                               then
-                                       log_warning_msg "Unable to load module dm-crypt"
-                                       continue
-                               fi
-
-                               if ! /sbin/cryptsetup isLuks ${devname}
+               if echo ${PERSISTENT_STORAGE} | grep -qe "\<filesystem\>"
+               then
+                       for label in ${overlays} ${snapshots}
+                       do
+                               if [ "$(/sbin/blkid -s LABEL -o value $dev 2>/dev/null)" = "${label}" ]
                                then
-                                       # we only look for encrypted subdevices
-                                       continue
+                                       overlays=$(echo ${overlays} | sed -e "s|\<${label}\>||")
+                                       snapshots=$(echo ${snapshots} | sed -e "s|\<${label}\>||")
+                                       echo "${label}=${dev}"
+                                       # skip to the next device
+                                       continue 2
                                fi
+                       done
+               fi
 
-                               while true
+               if echo ${PERSISTENT_STORAGE} | grep -qe "\<file\>"
+               then
+                       devfstype="$(get_fstype ${dev})"
+                       overlay_on_dev=""
+                       snapshot_on_dev=""
+                       backing="/$(basename ${dev})-backing"
+                       mkdir -p "${backing}"
+                       if is_supported_fs ${devfstype} && try_mount "${dev}" "${backing}" "rw" "${devfstype}"
+                       then
+                               for label in ${overlays}
                                do
-                                       load_keymap
-
-                                       /lib/cryptsetup/askpass "Enter passphrase for ${pers_label} on ${devname}: " | /sbin/cryptsetup -T 1 luksOpen ${devname} $(basename ${devname}) --key-file=-
-                                       error=${?}
-
-                                       devname="/dev/mapper/$(basename ${devname})"
-
-                                       if [ 0 -eq ${error} ]
+                                       path=${backing}/${PERSISTENT_PATH}${label}
+                                       if [ -f "${path}" ]
                                        then
-                                               unset error
-                                               break
-                                       fi
-
-                                       echo
-                                       echo -n "There was an error decrypting ${devname} ... Retry? [Y/n] " >&6
-                                       read answer
-
-                                       if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
-                                       then
-                                               unset answer
-                                               break
+                                               overlays=$(echo ${overlays} | sed -e "s|\<${label}\>||")
+                                               overlay_on_dev="yes"
+                                               echo "${label}=$(setup_loop "${path}" "loop" "/sys/block/loop*")"
                                        fi
                                done
-                       fi
-
-                       if echo ${PERSISTENT_STORAGE} | grep -qw filesystem && [ "$(/sbin/blkid -s LABEL -o value $devname 2>/dev/null)" = "${pers_label}" ]
-                       then
-                               echo "${devname}"
-                               return 0
-                       fi
 
-                       if ! echo ${PERSISTENT_STORAGE} | grep -qw file
-                       then
-                               # do not mount the device to find for image files
-                               # just skip this
-                               continue
-                       fi
-
-                       case "$(get_fstype ${devname})" in
-                               vfat|ext2|ext3|ext4|jffs2)
-                                       mkdir -p "${cow_backing}"
-                                       if try_mount "${devname}" "${cow_backing}" "rw"
-                                       then
-                                               if [ -f "${pers_fpath}" ]
+                               for label in ${snapshots}
+                               do
+                                       for ext in squashfs cpio.gz ext2 ext3 ext4 jffs2
+                                       do
+                                               path="${PERSISTENT_PATH}${label}.${ext}"
+                                               if [ -f "${backing}/${path}" ]
                                                then
-                                                       echo $(setup_loop "${pers_fpath}" "loop" "/sys/block/loop*")
-                                                       return 0
-                                               else
-                                                       umount ${cow_backing} > /dev/null 2>&1 || true
+                                                       snapshots=$(echo ${snapshots} | sed -e "s|\<${label}\>||")
+                                                       snapshot_on_dev="yes"
+                                                       echo "${label}=${dev}:${backing}:${path}"
                                                fi
-                                       fi
-                                       ;;
-                               *)
-                                       ;;
-                       esac
-               done
-       done
-       return 1
-}
-
-find_files ()
-{
-       # return the a string composed by device name, mountpoint an the first of ${filenames} found on a supported partition
-       #  if is not in black_listed_devices.
-       #  Additionally, if the white_listed_devices list is non-empty, the
-       #  parent block device of the returned device must be part of this list.
-       # FIXME: merge with above function
-
-       filenames="${1}"
-       snap_backing="/snap-backing"
-       black_listed_devices="${2}"
-       white_listed_devices="${3}"
-
-       for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop | grep -v ram | grep -v fd)
-       do
-               fulldevname=$(sys2dev "${sysblock}")
-
-               if echo "${black_listed_devices}" | grep -q -w "${fulldevname}"
-               then
-                       # skip this device entirely
-                       break
-               fi
-
-               if [ -n "${white_listed_devices}" ]
-               then
-                       if echo "${white_listed_devices}" | grep -v -q -w "${fulldevname}"
-                       then
-                               # skip this device entirely
-                               break
-                       fi
-               fi
-
-               for dev in $(subdevices "${sysblock}")
-               do
-                       devname=$(sys2dev "${dev}")
-                       devfstype="$(get_fstype ${devname})"
-
-                       if echo "${black_listed_devices}" | grep -q -w "${devname}"
-                       then
-                               # skip this subdevice
-                               break
+                                       done
+                               done
                        fi
-
-                       if is_supported_fs ${devfstype}
+                       if [ -z "${overlay_on_dev}" ]
                        then
-                               mkdir -p "${snap_backing}"
-
-                               if try_mount "${devname}" "${snap_backing}" "ro" "${devfstype}"
+                               umount ${backing} > /dev/null 2>&1 || true
+                               if [ -z "${snapshot_on_dev}" ] && [ -n "${luks_device}" ] && /sbin/cryptsetup status "${luks_device}" 1> /dev/null
                                then
-                                       for filename in ${filenames}
-                                       do
-                                               if [ -f "${snap_backing}/${filename}" ]
-                                               then
-                                                       echo "${devname} ${snap_backing} ${filename}"
-                                                       umount ${snap_backing}
-                                                       return 0
-                                               fi
-                                       done
+                                       /sbin/cryptsetup luksClose "${luks_device}"
                                fi
-
-                               umount ${snap_backing}
                        fi
-               done
+               fi
        done
 }