factory-reset-external

#!/bin/sh
#
# External storage factory reset for Sailfish OS.
#
# Copyright (C) 2017 Jolla Ltd.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; version 2
# of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

# Parameters:
# $@ -> Device paths of partitions to reformat.

format_script()
{
cat << 'EOF'
#!/bin/sh

function log
{
	echo "$0: $1" > /dev/kmsg
}

for device in $@; do
	unset TYPE
	unset LABEL
	unset UUID

	if [ ! -e "$device" ]; then
		continue
	fi

	partitionname=$( basename $device )
	partitionblock=$( readlink -f /sys/class/block/$partitionname )

	if [ ! -e "$partitionblock" ]; then
		continue
	fi

	deviceblock=$( dirname "$partitionblock" )

	if ! grep -Fxq SD $deviceblock/device/type; then
		log "$device is not an SD-card! Skipping"
		continue
	fi

	eval "$(/sbin/blkid -c /dev/null -o export $device)"

	case "$TYPE" in
		vfat)
			format_command=/sbin/mkfs.vfat
			format_arguments=()
			if [ ! -z "$UUID" ]; then
				format_arguments=( "${format_arguments[@]}" -i "${UUID//-}" )
			fi
			if [ ! -z "$LABEL" ]; then
				format_arguments=( "${format_arguments[@]}" -n "${LABEL}" )
			fi
			;;
		ext4)
			format_command=/sbin/mkfs.ext4
			format_arguments=( -F -E root_owner=100000:100000 )
			if [ ! -z "$UUID" ]; then
				format_arguments=( "${format_arguments[@]}" -U "${UUID}" )
			fi
			if [ ! -z "$LABEL" ]; then
				format_arguments=( "${format_arguments[@]}" -L "${LABEL}")
			fi
			;;
		*)
			if [ -z "$TYPE" ]; then
				continue
			fi

			format_command=
			format_arguments=
			;;
	esac

	if [ -f $format_command ]; then
		log "Formatting $device as $TYPE"

		if test "$SAILFISHOS_WIPE_PARTITIONS" = "1"; then
			dd if=/dev/zero of=$device bs=1M
		fi

		echo $format_command "${format_arguments[@]}" $device
		$format_command "${format_arguments[@]}" $device || log "Failed to format $device"
	else
		TEMPMOUNT=$(mktemp -d)

		if mount $device $TEMPMOUNT; then
			log "Erasing data from $device"

			find $TEMPMOUNT -mindepth 1 -delete

			if test "$SAILFISHOS_WIPE_PARTITIONS" = "1"; then
				dd if=/dev/zero of=$TEMPMOUNT/large
				rm -f $TEMPMOUNT/large
			fi

			umount $TEMPMOUNT
		else
			log "Failed to mount $device to erase data"

			if test "$SAILFISHOS_WIPE_PARTITIONS" = "1"; then
				log "Erasing partition"
				dd if=/dev/zero of=$device
			fi
		fi

		rmdir $TEMPMOUNT
	fi
done
EOF
}

# Format devices from the rootfs where there is a full shell and more file-system tools.
TEMPMOUNT=$(mktemp -d)
if mount /dev/sailfish/root $TEMPMOUNT; then
	mount -t tmpfs tmpfs $TEMPMOUNT/tmp
	mount -t devtmpfs devtmpfs $TEMPMOUNT/dev
	mount -t proc proc $TEMPMOUNT/proc
	mount -t sysfs sys $TEMPMOUNT/sys
	format_script > $TEMPMOUNT/tmp/format-devices
	chmod 755 $TEMPMOUNT/tmp/format-devices
	chroot $TEMPMOUNT /tmp/format-devices $@
	umount $TEMPMOUNT/tmp $TEMPMOUNT/dev $TEMPMOUNT/proc $TEMPMOUNT/sys

	# Clean up
	umount $TEMPMOUNT
else
	echo "$0: Failed to mount rootfs" > /dev/kmsg
	if test "$SAILFISH_WIPE_PARTITIONS" = "$1"; then
		for device in $@; do
			dd if=/dev/zero of=$device
		done
	fi
fi
rmdir $TEMPMOUNT