X-Git-Url: https://git.grml.org/?a=blobdiff_plain;f=scripts%2Flive-helpers;h=f1ebe8625e070ac94418bfbffa22e08f2220785d;hb=e2d2d40b67bdbbef25f1b53f4fbc2eedc72f12cd;hp=f88108aa00e02e8811e3b6b8dd8447515588a696;hpb=544c8db939aa26e57a2765fc0da55554ad8b3ec6;p=live-boot-grml.git

diff --git a/scripts/live-helpers b/scripts/live-helpers
index f88108a..f1ebe86 100644
--- a/scripts/live-helpers
+++ b/scripts/live-helpers
@@ -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 +311,144 @@ 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
+					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} ]
-					then
-						unset error
-						break
-					fi
-
-					echo >&6
-					echo -n "There was an error decrypting ${devname} ... Retry? [Y/n] " >&6
-					read answer
-
-					if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
+					path=${backing}/${PERSISTENT_PATH}${label}
+					if [ -f "${path}" ]
 					then
-						unset answer
-						break
+						overlay_on_dev="yes"
+						echo "${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 ${cow_backing} > /dev/null 2>&1 || true
+							snapshot_on_dev="yes"
+							echo "${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
 }
 
@@ -570,3 +552,365 @@ non_removable_dev ()
 
 	echo "${ret}"
 }
+
+link_files ()
+{
+	# create source's directory structure in dest, and recursively
+	# create symlinks in dest to to all files in source. if mask
+	# is non-empty, remove mask from all source paths when
+	# creating links (will be necessary if we change root, which
+	# live-boot normally does (into $rootmnt)).
+
+	# remove multiple /:s and ensure ending on /
+	local src_dir="$(echo "${1}"/ | sed -e 's|/\+|/|g')"
+	local dest_dir="$(echo "${2}"/ | sed -e 's|/\+|/|g')"
+	local src_mask="${3}"
+
+	# This check can only trigger on the inital, non-recursive call since
+	# we create the destination before recursive calls
+	if [ ! -d "${dest_dir}" ];
+	then
+		log_warning_msg "Must link_files into a directory"
+		return
+	fi
+
+	find "${src_dir}" -mindepth 1 -maxdepth 1 | while read x; do
+		local src="${x}"
+		local dest="${dest_dir}$(basename "${x}")"
+		if [ -d "${src}" ];
+		then
+			if [ -z "$(ls -A "${src}")" ];
+			then
+				continue
+			fi
+			if [ ! -d "${dest}" ];
+			then
+				mkdir -p "${dest}"
+				prev="$(dirname "${dest}")"
+				chown $(stat -c %u:%g "${prev}") "${dest}"
+				chmod $(stat -c %a "${prev}") "${dest}"
+			fi
+			link_files "${src}" "${dest}" "${src_mask}"
+		else
+			if [ -n "${src_mask}" ]
+			then
+				src="$(echo ${src} | sed "s|^${src_mask}||")"
+			fi
+			rm -rf "${dest}" 2> /dev/null
+			ln -s "${src}" "${dest}"
+		fi
+	done
+}
+
+do_union () {
+	local unionmountpoint="${1}"	# directory where the union is mounted
+	local unionrw="${2}"		# branch where the union changes are stored
+	local unionro1="${3}"		# first underlying read-only branch (optional)
+	local unionro2="${4}"		# second underlying read-only branch (optional)
+
+	if [ "${UNIONTYPE}" = "aufs" ]
+	then
+		rw_opt="rw"
+		ro_opt="rr+wh"
+		noxino_opt="noxino"
+	elif [ "${UNIONTYPE}" = "unionfs-fuse" ]
+	then
+		rw_opt="RW"
+		ro_opt="RO"
+	else
+		rw_opt="rw"
+		ro_opt="ro"
+	fi
+
+	case "${UNIONTYPE}" in
+		unionfs-fuse)
+			unionmountopts="-o cow -o noinitgroups -o default_permissions -o allow_other -o use_ino -o suid"
+			unionmountopts="${unionmountopts} ${unionrw}=${rw_opt}"
+			if [ -n "${unionro1}" ]
+			then
+				unionmountopts="${unionmountopts}:${unionro1}=${ro_opt}"
+			fi
+			if [ -n "${unionro2}" ]
+			then
+				unionmountopts="${unionmountopts}:${unionro2}=${ro_opt}"
+			fi
+			( sysctl -w fs.file-max=391524 ; ulimit -HSn 16384
+			unionfs-fuse ${unionmountopts} "${unionmountpoint}" ) && \
+			( mkdir -p /run/sendsigs.omit.d
+			pidof unionfs-fuse >> /run/sendsigs.omit.d/unionfs-fuse || true )
+			;;
+
+		overlayfs)
+			# XXX: can unionro2 be used? (overlayfs only handles two dirs, but perhaps they can be chained?)
+			# XXX: and can unionro1 be optional? i.e. can overlayfs skip lowerdir?
+			unionmountopts="-o noatime,lowerdir=${unionro1},upperdir=${unionrw}"
+			mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"
+			;;
+
+		*)
+			unionmountopts="-o noatime,${noxino_opt},dirs=${unionrw}=${rw_opt}"
+			if [ -n "${unionro1}" ]
+			then
+				unionmountopts="${unionmountopts}:${unionro1}=${ro_opt}"
+			fi
+			if [ -n "${unionro2}" ]
+			then
+				unionmountopts="${unionmountopts}:${unionro2}=${ro_opt}"
+			fi
+			mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"
+			;;
+	esac
+}
+
+get_custom_mounts () {
+	# Side-effect: leaves $devices with live.persist mounted in ${rootmnt}/live/persistent
+	# Side-effect: prints info to file $custom_mounts
+
+	local devices="${1}"
+	local custom_mounts="${2}" # print result to this file
+	local rootmnt="${3}"       # should be set empty post-live-boot
+
+	local bindings="/bindings.list"
+	local links="/links.list"
+	rm -rf ${bindings} ${links} 2> /dev/null
+	local persistent_backing="${rootmnt}/live/persistent"
+
+	for device in ${devices}
+	do
+		if [ ! -b "${device}" ]
+		then
+			continue
+		fi
+		local device_name="$(basename ${device})"
+		local backing="${persistent_backing}/${device_name}"
+		mkdir -p "${backing}"
+		local device_fstype="$(get_fstype ${device})"
+		if [ -z "${PERSISTENT_READONLY}" ]
+		then
+			device_mount_opts="rw,noatime"
+		else
+			device_mount_opts="ro,noatime"
+		fi
+		local device_used=""
+		mount -t "${device_fstype}" -o "${device_mount_opts}" "${device}" "${backing}"
+		local include_list="${backing}/${persistence_list}"
+		if [ ! -r "${include_list}" ]
+		then
+			umount "${backing}"
+			rmdir "${backing}"
+			continue
+		fi
+
+		[ "${DEBUG}" = "Yes" ] && cp ${include_list} ${persistent_backing}/${persistence_list}.${device_name}
+		while read source dest options # < ${include_list}
+		do
+			if echo ${source} | grep -qe "^[[:space:]]*\(#.*\)\?$"
+			then
+				# skipping empty or commented lines
+				continue
+			fi
+
+			if echo ${dest} | grep -qe "^[^/]"
+			then
+				options="${dest}"
+				dest="${source}"
+			elif [ -z "${dest}" ]
+			then
+				dest="${source}"
+			fi
+
+			if echo ${dest} | grep -qe "^/\+$\|^/\+live\(/.*\)\?$"
+			then
+				# mounting on / or /live could cause trouble
+				log_warning_msg "Skipping unsafe custom mount on ${dest}"
+				continue
+			fi
+
+			for opt in $(echo ${options} | tr ',' ' ');
+			do
+				case "${opt}" in
+					linkfiles|union)
+						;;
+					*)
+						log_warning_msg "Skipping custom mount with unkown option: ${opt}"
+						continue 2
+						;;
+				esac
+			done
+
+			# FIXME: handle case: we already have /a/b in
+			# $bindings added from current $device, but
+			# now we find /a -- /a should replace /a/b in
+			# $bindings.
+
+			# FIXME: handle case: we have /a in $bindings
+			# from current $device, now we find /a/b, so
+			# we skip /a/b
+
+			# ensure that no multiple-/ occur in paths
+			local full_source="$(echo ${backing}/${source}/ | sed -e 's|/\+|/|g')"
+			local full_dest="$(echo ${rootmnt}/${dest}/ | sed -e 's|/\+|/|g')"
+			device_used="yes"
+			if echo ${options} | grep -qe "\<linkfiles\>";
+			then
+				echo "${full_source} ${full_dest} ${options}" >> ${links}
+			else
+				echo "${full_source} ${full_dest} ${options}" >> ${bindings}
+			fi
+		done < ${include_list}
+
+		if [ -z "${device_used}" ]
+		then
+			# this device was not used for / earlier, or
+			# custom mount point now, so it's useless
+			umount "${backing}"
+			rmdir "${backing}"
+		fi
+	done
+
+	# We sort the list according to destination so we're sure that
+	# we won't hide a previous mount. We also ignore duplicate
+	# destinations in a more or less arbitrary way.
+	[ -e "${bindings}" ] && sort -k2 -sbu ${bindings} >> ${custom_mounts}
+	rm ${bindings}
+
+	# After all mounts are considered we add symlinks so they
+	# won't be hidden by some mount.
+	[ -e "${links}" ] && sort -k2 -sbu ${links} >> ${custom_mounts}
+	rm ${links}
+
+	rm -f ${bindings} ${links} 2> /dev/null
+	echo ${custom_mounts}
+}
+
+do_custom_mounts () {
+	local custom_mounts="${1}" # the ouput from get_custom_mounts()
+	local rootmnt="${2}"       # should be set empty post-live-boot
+
+	while read source dest options # < ${custom_mounts}
+	do
+		local opt_linkfiles=""
+		local opt_union=""
+		for opt in $(echo ${options} | tr ',' ' ');
+		do
+			 case "${opt}" in
+				linkfiles)
+					opt_linkfiles="yes"
+					;;
+				union)
+					opt_union="yes"
+					;;
+			esac
+		done
+
+		if mountpoint -q "${dest}";
+		then
+			log_warning_msg "Skipping custom mount ${source} on ${dest}: destination is already a mount point"
+			continue
+		fi
+
+		# FIXME: we don't handle already existing
+		# non-directory files in the paths of both $source and
+		# $dest.
+
+		if [ ! -d "${dest}" ]
+		then
+			# if ${dest} is in /home/$user, try fixing
+			# proper ownership
+			# FIXME: this should really be handled by
+			# live-config since we don't know for sure
+			# which uid a certain user has until then
+			if echo ${dest} | grep -qe "^${rootmnt}/*home/\+[^/]\+"
+			then
+				path="/"
+				for dir in $(echo ${dest} | sed -e 's|/\+| |g')
+				do
+					path=${path}/${dir}
+					if [ ! -e ${path} ]
+					then
+						mkdir -p ${path}
+						# assume that the intended user is the first, which is usually the case
+						chown 1000:1000 ${path}
+					fi
+				done
+			else
+				mkdir -p ${dest}
+			fi
+		fi
+
+		# if ${source} doesn't exist on our persistent media
+		# we bootstrap it with $dest from the live filesystem.
+		# this both makes sense and is critical if we're
+		# dealing with /etc or other system dir.
+		if [ ! -d "${source}" ]
+		then
+			if [ -n "${PERSISTENT_READONLY}" ] || [ -n "${opt_linkfiles}" ]
+			then
+				continue
+			elif [ -n "${opt_union}" ]
+			then
+				# union's don't need to be bootstrapped
+				mkdir "${source}"
+			else
+				# ensure that $dest is not copied *into* $source
+				mkdir -p "$(dirname ${source})"
+				cp -a "${dest}" "${source}"
+			fi
+		fi
+
+		rofs_dest_backing=""
+		for d in ${rootmnt}/live/rofs/*
+		do
+			if [ -n "${rootmnt}" ]
+			then
+				rofs_dest_backing="${d}/$(echo ${dest} | sed -e "s|${rootmnt}||")"
+			else
+				rofs_dest_backing="${d}/${dest}"
+
+			fi
+			if [ -d "${rofs_dest_backing}" ]
+			then
+				break
+			else
+				rofs_dest_backing=""
+			fi
+		done
+
+		if [ -z "${PERSISTENT_READONLY}" ]
+		then
+			if [ -n "${opt_linkfiles}" ]
+			then
+				links_source="${source}"
+				links_dest="${dest}"
+			elif [ -n "${opt_union}" ]
+			then
+				do_union ${dest} ${source} ${rofs_dest_backing}
+			else
+				mount --bind "${source}" "${dest}"
+			fi
+		else
+			if [ -n "${opt_linkfiles}" ]
+			then
+				links_dest="${dest}"
+				dest="$(mktemp -d ${persistent_backing}/links_source-XXXXXX)"
+				links_source="${dest}"
+			fi
+			if [ -n "${rootmnt}" ]
+			then
+				cow_dir="$(echo ${dest} | sed -e "s|${rootmnt}|/cow/|")"
+			else
+				cow_dir="/live/cow/${dest}"
+			fi
+			mkdir -p ${cow_dir}
+			do_union ${dest} ${cow_dir} ${source} ${rofs_dest_backing}
+		fi
+
+		if [ -n "${opt_linkfiles}" ]
+		then
+			link_files "${links_source}" "${links_dest}" "${rootmnt}"
+		fi
+
+		PERSISTENCE_IS_ON="1"
+		export PERSISTENCE_IS_ON
+	done < ${custom_mounts}
+}