path: root/scripts/live-helpers

# live-initramfs helper functions, used by live-initramfs on boot and by live-snapshot

if [ ! -x "/bin/fstype" ]
then
	# klibc not in path -> not in initramfs
	export PATH="${PATH}:/usr/lib/klibc/bin"
fi

# handle upgrade path from old udev (using udevinfo) to
# recent versions of udev (using udevadm info)
if [ -x /sbin/udevadm ]
then
	udevinfo='/sbin/udevadm info'
else
	udevinfo='udevinfo'
fi

sys2dev ()
{
	sysdev=${1#/sys}
	echo "/dev/$($udevinfo -q name -p ${sysdev} 2>/dev/null|| echo ${sysdev##*/})"
}

subdevices ()
{
	sysblock=${1}
	r=""

	for dev in "${sysblock}" "${sysblock}"/*
	do
		if [ -e "${dev}/dev" ]
		then
			r="${r} ${dev}"
		fi
	done

	echo ${r}
}

is_supported_fs ()
{
	fstype="${1}"

	# Validate input first
	if [ -z "${fstype}" ]
	then
		return 1
	fi

	# Try to look if it is already supported by the kernel
	if grep -q ${fstype} /proc/filesystems
	then
		return 0
	else
		# Then try to add support for it the gentle way using the initramfs capabilities
		modprobe ${fstype}
		if grep -q ${fstype} /proc/filesystems
		then
			return 0
		# Then try the hard way if /root is already reachable
		else
			kmodule="/root/lib/modules/`uname -r`/${fstype}/${fstype}.ko"
			if [ -e "${kmodule}" ]
			then
				insmod "${kmodule}"
				if grep -q ${fstype} /proc/filesystems
				then
					return 0
				fi
			fi
		fi
	fi

	return 1
}

get_fstype ()
{
	# udev (>= 146) no longer provides vol_id
	if [ -x /lib/udev/vol_id ]
	then
		# lenny
		/lib/udev/vol_id -t ${1} 2>/dev/null
	else
		# squeeze
		/sbin/blkid -s TYPE -o value $1 2>/dev/null
	fi
}

where_is_mounted ()
{
	device=${1}

	if grep -q "^${device} " /proc/mounts
	then
		# return the first found
		grep -m1 "^${device} " /proc/mounts | cut -f2 -d ' '
	fi
}

lastline ()
{
	while read lines
	do
		line=${lines}
	done

	echo "${line}"
}

base_path ()
{
	testpath="${1}"
	mounts="$(awk '{print $2}' /proc/mounts)"
	testpath="$(busybox realpath ${testpath})"

	while true
	do
		if echo "${mounts}" | grep -qs "^${testpath}"
		then
			set -- $(echo "${mounts}" | grep "^${testpath}" | lastline)
			echo ${1}
			break
		else
			testpath=$(dirname $testpath)
		fi
	done
}

fs_size ()
{
	# Returns used/free fs kbytes + 5% more
	# You could pass a block device as ${1} or the mount point as ${2}

	dev="${1}"
	mountp="${2}"
	used="${3}"

	if [ -z "${mountp}" ]
	then
		mountp="$(where_is_mounted ${dev})"

		if [ -z "${mountp}" ]
		then
			mountp="/mnt/tmp_fs_size"

			mkdir -p "${mountp}"
			mount -t $(get_fstype "${dev}") -o ro "${dev}" "${mountp}" || log_warning_msg "cannot mount -t $(get_fstype ${dev}) -o ro ${dev} ${mountp}"

			doumount=1
		fi
	fi

	if [ "${used}" = "used" ]
	then
		size=$(du -ks ${mountp} | cut -f1)
		size=$(expr ${size} + ${size} / 20 ) # FIXME: 5% more to be sure
	else
		# free space
		size="$(df -k | grep -s ${mountp} | awk '{print $4}')"
	fi

	if [ -n "${doumount}" ]
	then
		umount "${mountp}" || log_warning_msg "cannot umount ${mountp}"
		rmdir "${mountp}"
	fi

	echo "${size}"
}

load_keymap ()
{
	# Load custom keymap
	if [ -x /bin/loadkeys -a -r /etc/boottime.kmap.gz ]
	then
		loadkeys /etc/boottime.kmap.gz
	fi
}

setup_loop ()
{
	local fspath=${1}
	local module=${2}
	local pattern=${3}
	local offset=${4}
	local encryption=${5}
	local readonly=${6}

	# the output of setup_loop is evaluated in other functions,
	# modprobe leaks kernel options like "libata.dma=0"
	# as "options libata dma=0" on stdout, causing serious
	# problems therefor, so instead always avoid output to stdout
	modprobe -q -b "${module}" 1>/dev/null

	udevadm settle

	for loopdev in ${pattern}
	do
		if [ "$(cat ${loopdev}/size)" -eq 0 ]
		then
			dev=$(sys2dev "${loopdev}")
			options=''

			if [ -n "${readonly}" ]
			then
				if losetup --help 2>&1 | grep -q -- "-r\b"
				then
					options="${options} -r"
				fi
			fi

			if [ 0 -lt "${offset}" ]
			then
				options="${options} -o ${offset}"
			fi

			if [ -z "${encryption}" ]
			then
				losetup ${options} "${dev}" "${fspath}"
			else
				# Loop AES encryption
				while true
				do
					load_keymap

					echo -n "Enter passphrase for root filesystem: " >&6
					read -s passphrase
					echo "${passphrase}" > /tmp/passphrase
					unset passphrase
					exec 9</tmp/passphrase
					/sbin/losetup ${options} -e "${encryption}" -p 9 "${dev}" "${fspath}"
					error=${?}
					exec 9<&-
					rm -f /tmp/passphrase

					if [ 0 -eq ${error} ]
					then
						unset error
						break
					fi

					echo
					echo -n "There was an error decrypting the root filesystem ... Retry? [Y/n] " >&6
					read answer

					if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
					then
						unset answer
						break
					fi
				done
			fi

			echo "${dev}"
			return 0
		fi
	done

	panic "No loop devices available"
}

try_mount ()
{
	dev="${1}"
	mountp="${2}"
	opts="${3}"
	fstype="${4}"

	old_mountp="$(where_is_mounted ${dev})"

	if [ -n "${old_mountp}" ]
	then
		if [ "${opts}" != "ro" ]
		then
			mount -o remount,"${opts}" "${dev}" "${old_mountp}" || panic "Remounting ${dev} ${opts} on ${old_mountp} failed"
		fi

		mount -o bind "${old_mountp}" "${mountp}" || panic "Cannot bind-mount ${old_mountp} on ${mountp}"
	else
		if [ -z "${fstype}" ]
		then
			fstype=$(get_fstype "${dev}")
		fi
		mount -t "${fstype}" -o "${opts}" "${dev}" "${mountp}" || \
		( echo "SKIPPING: Cannot mount ${dev} on ${mountp}, fstype=${fstype}, options=${opts}" > live.log && return 0 )
	fi
}

find_cow_device ()
{
	# Returns a device containing a partition labeled "${pers_label}" or containing a file named the same way
	#  in the latter case the partition containing the file is left mounted
	#  if is not in black_listed_devices
	pers_label="${1}"
	cow_backing="/${pers_label}-backing"
	black_listed_devices="${2}"

	if [ -z "${PERSISTENT_PATH}" ]
	then
		pers_fpath=${cow_backing}/${pers_label}
	else
		pers_fpath=${cow_backing}/${PERSISTENT_PATH}/${pers_label}
	fi

	for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop | grep -v ram | grep -v fd)
	do
		for dev in $(subdevices "${sysblock}")
		do
			devname=$(sys2dev "${dev}")

			if echo "${black_listed_devices}" | grep -q "${devname}"
			then
				# skip this device enterely
				break
			fi

			# Checking for a luks device
			if [ "${PERSISTENT}" = "cryptsetup" ] && [ -e /sbin/cryptsetup ] && /sbin/cryptsetup isLuks ${devname}
			then
				while true
				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} ]
					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
					fi
				done
			fi

			# udev (>= 146) no longer provides vol_id
			if [ -x /lib/udev/vol_id ]
			then
				# lenny
				if [ "$(/lib/udev/vol_id -l ${devname} 2>/dev/null)" = "${pers_label}" ]
				then
					echo "${devname}"
					return 0
				fi
			else
				# squeeze
				if [ "$(/sbin/blkid -s LABEL -o value $devname 2>/dev/null)" = "${pers_label}" ]
				then
					echo "${devname}"
					return 0
				fi
			fi

			if [ "${PERSISTENT}" = "nofiles" ]
			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}" ]
						then
							echo $(setup_loop "${pers_fpath}" "loop" "/sys/block/loop*")
							return 0
						else
							umount ${cow_backing} > /dev/null 2>&1 || true
						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
	# FIXME: merge with above function

	filenames="${1}"
	snap_backing="/snap-backing"
	black_listed_devices="${2}"

	for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop | grep -v ram | grep -v fd)
	do
		for dev in $(subdevices "${sysblock}")
		do
			devname=$(sys2dev "${dev}")
			devfstype="$(get_fstype ${devname})"

			if echo "${black_listed_devices}" | grep -q "${devname}"
			then
				# skip this device enterely
				break
			fi

			if is_supported_fs ${devfstype}
			then
				mkdir -p "${snap_backing}"

				if try_mount "${devname}" "${snap_backing}" "ro" "${devfstype}"
				then
					for filename in ${filenames}
					do
						if [ -f "${snap_backing}/${filename}" ]
						then
							echo "${devname} ${snap_backing} ${filename}"
							umount ${snap_backing}
							return 0
						fi
					done
				fi

				umount ${snap_backing}
			fi
		done
	done
}

get_mac ()
{
	mac=""

	for adaptor in /sys/class/net/*
	do
		status="$(cat ${adaptor}/iflink)"

		if [ "${status}" -eq 2 ]
		then
			mac="$(cat ${adaptor}/address)"
			mac="$(echo ${mac} | sed 's/:/-/g' | tr '[a-z]' '[A-Z]')"
		fi
	done

	echo ${mac}
}

is_luks()
{
    devname="${1}"
    if [ -x /sbin/cryptsetup ]
    then
	/sbin/cryptsetup isLuks "${devname}" 2>/dev/null || ret=${?}
	return ${ret}
    else
	return 1
    fi

}