| #!/bin/sh |
| |
| # Copyright (c) 2010 The Chromium OS Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| # This script can be called during startup to trash the stateful partition |
| # and possibly reset the other root filesystem |
| |
| . /usr/share/misc/chromeos-common.sh |
| SCRIPT="$0" |
| |
| # stateful partition isn't around for logging, so dump to the screen: |
| set -x |
| |
| # Log file to store the output of this run. |
| CLOBBER_STATE_LOG="/tmp/clobber-state.log" |
| : ${TTY=/dev/tty1} |
| |
| # Run "clobber-state fast" to clobber the state quickly but unsecurely. |
| FACTORY_WIPE=$(echo "$@" | grep -sqw factory && echo "factory") |
| FAST_WIPE=$(echo "$@" | grep -sqw fast && echo "fast") |
| KEEPIMG=$(echo "$@" | grep -sqw keepimg && echo "keepimg") |
| SAFE_WIPE=$(echo "$@" | grep -sqw safe && echo "safe") |
| |
| PRESERVED_TAR="/tmp/preserve.tar" |
| LABMACHINE=".labmachine" |
| STATE_PATH="/mnt/stateful_partition" |
| POWERWASH_COUNT="${STATE_PATH}/unencrypted/preserve/powerwash_count" |
| |
| # List of files to preserve relative to /mnt/stateful_partition/ |
| PRESERVED_FILES="" |
| PRESERVED_LIST="" |
| |
| ensure_root_account() { |
| if [ $(id -u) -ne 0 ]; then |
| echo 'You must run this as root' |
| exit 1 |
| fi |
| } |
| |
| redirect_log_start() { |
| # Redirect stdout to our log. |
| exec >"${CLOBBER_STATE_LOG}" 2>&1 |
| } |
| |
| redirect_log_stop() { |
| # Stop appending to the log and preserve it. |
| exec >/dev/null 2>&1 |
| mv -f "${CLOBBER_STATE_LOG}" "${STATE_PATH}/unencrypted/clobber-state.log" |
| } |
| |
| preserve_files() { |
| # Preserve these files in safe mode. |
| if [ "$SAFE_WIPE" = "safe" ]; then |
| PRESERVED_FILES=" |
| unencrypted/preserve/attestation.epb |
| unencrypted/preserve/enrollment_state.epb |
| unencrypted/preserve/local_tpm_data |
| unencrypted/preserve/powerwash_count |
| unencrypted/preserve/update_engine/prefs/rollback-version |
| home/.shadow/install_attributes.pb |
| " |
| |
| # Powerwash count is only preserved for "safe" powerwashes. |
| COUNT=1 |
| if [ -f $POWERWASH_COUNT ]; then |
| COUNT_UNSANITIZED=$(head -1 $POWERWASH_COUNT | cut -c1-4) |
| if [ $(expr "$COUNT_UNSANITIZED" : "^[0-9][0-9]*$") -ne 0 ]; then |
| COUNT=$(( COUNT_UNSANITIZED + 1 )) |
| fi |
| fi |
| echo $COUNT > $POWERWASH_COUNT |
| fi |
| |
| # For a factory wipe (and only factory) preserve seed for CRX cache. |
| if [ "$FACTORY_WIPE" = "factory" ]; then |
| IMPORT_FILES="$(cd ${STATE_PATH}; |
| echo unencrypted/import_extensions/extensions/*.crx)" |
| if [ "$IMPORT_FILES" != \ |
| "unencrypted/import_extensions/extensions/*.crx" ]; then |
| PRESERVED_FILES="${PRESERVED_FILES} ${IMPORT_FILES}" |
| fi |
| fi |
| |
| # Test images in the lab enable certain extra behaviors if the |
| # .labmachine flag file is present. Those behaviors include some |
| # important recovery behaviors (cf. the recover_duts upstart job). |
| # We need those behaviors to survive across power wash, otherwise, |
| # the current boot could wind up as a black hole. |
| if [ -f "${STATE_PATH}/${LABMACHINE}" ] && |
| crossystem 'debug_build?1'; then |
| PRESERVED_FILES="${PRESERVED_FILES} ${LABMACHINE}" |
| fi |
| |
| if [ -n "$PRESERVED_FILES" ]; then |
| # We want to preserve permissions and recreate the directory structure |
| # for all of the files in the PRESERVED_FILES variable. In order to do |
| # so we run tar --no-recurison and specify the names of each of the |
| # parent directories. For example for home/.shadow/install_attributes.pb |
| # we pass to tar home home/.shadow home/.shadow/install_attributes.pb |
| for file in $PRESERVED_FILES; do |
| if [ ! -e "$STATE_PATH/$file" ]; then |
| continue |
| fi |
| path=$file |
| while [ "$path" != '.' ]; do |
| PRESERVED_LIST="$path $PRESERVED_LIST" |
| path=$(dirname $path) |
| done |
| done |
| tar cf $PRESERVED_TAR -C $STATE_PATH --no-recursion -- $PRESERVED_LIST |
| fi |
| } |
| |
| wipe_block_dev() { |
| DEV="$1" |
| # Wipe the filesystem size if we can determine it. Full partition wipe |
| # takes a long time on 16G SSD or rotating media. |
| if dumpe2fs ${DEV} ; then |
| FS_BLOCKS=$(dumpe2fs -h ${DEV} | grep "Block count" | sed "s/^.*:\W*//") |
| FS_BLOCKSIZE=$(dumpe2fs -h ${DEV} | grep "Block size" | sed "s/^.*:\W*//") |
| else |
| FS_BLOCKS=$(numsectors ${DEV}) |
| FS_BLOCKSIZE=512 |
| fi |
| BLOCKS_4M=$((4 * 1024 * 1024 / $FS_BLOCKSIZE)) # 4MiB in sectors |
| FULL_BLKS=$(($FS_BLOCKS / $BLOCKS_4M)) |
| REMAINDER_SECTORS=$(($FS_BLOCKS % $BLOCKS_4M)) |
| |
| if type pv; then |
| # Opening a TTY device with no one else attached will allocate and reset |
| # terminal attributes. To prevent user input echo and ctrl-breaks, we need |
| # to allocate and configure the terminal before using tty for output. |
| # Note &2 is currently used for debug messages dumping so we can't redirect |
| # subshell by 2>"${TTY}". |
| ( stty -F "${TTY}" raw -echo -cread |
| pv -etp -s $((4 * 1024 * 1024 * ${FULL_BLKS})) /dev/zero 2>"${TTY}" | |
| dd of=${DEV} bs=4M count=${FULL_BLKS} iflag=fullblock oflag=sync |
| ) >"${TTY}" |
| else |
| dd if=/dev/zero of=${DEV} bs=4M count=${FULL_BLKS} |
| fi |
| dd if=/dev/zero of=${DEV} bs=${FS_BLOCKSIZE} count=${REMAINDER_SECTORS} \ |
| seek=$(($FULL_BLKS * $BLOCKS_4M)) |
| } |
| |
| # Get the specified information from the specified UBI volume. |
| # $1 the field name such as "reserved_for_bad", or "data_bytes". |
| # $2 the volume number such as "1" or "1_0". |
| get_ubi_var() { |
| local field="$1" |
| local part="$2" |
| cat "/sys/class/ubi/ubi${part}/${field}" |
| } |
| |
| get_ubi_reserved_ebs() { |
| get_ubi_var reserved_for_bad "$@" |
| } |
| |
| get_ubi_volume_size() { |
| local part="$1" |
| get_ubi_var data_bytes "${part}_0" |
| } |
| |
| # Calculate the maximum number of bad blocks per 1024 blocks for UBI. |
| # $1 partition number |
| calculate_ubi_max_beb_per_1024() { |
| local part_no mtd_size eb_size nr_blocks |
| part_no="$1" |
| # The max beb per 1024 is on the total device size, not the partition size. |
| mtd_size=$(cat /sys/class/mtd/mtd0/size) |
| eb_size=$(cat /sys/class/mtd/mtd0/erasesize) |
| nr_blocks=$((mtd_size / eb_size)) |
| reserved_ebs=$(get_ubi_reserved_ebs "${part_no}") |
| echo $((reserved_ebs * 1024 / nr_blocks)) |
| } |
| |
| # Wipe a UBI device. |
| # $1 the device node. This must be in the form /dev/ubiX_0 or /dev/ubiblockX_0. |
| wipe_ubi_dev() { |
| local dev phy_dev part_no part_name |
| dev="$1" |
| part_no=$(echo "${dev}" | sed -e 's#/dev/ubi\(block\)\?\([0-9]\)_0#\2#') |
| phy_dev="/dev/ubi${part_no}" |
| # We only wipe part 1, 3, and 5 in this function. |
| case "${part_no}" in |
| "1") |
| part_name="STATE" |
| ;; |
| "3") |
| part_name="ROOT_A" |
| ;; |
| "5") |
| part_name="ROOT_B" |
| ;; |
| *) |
| part_name="UNKNOWN_${part_no}" |
| echo "Do not know how to name UBI partition number ${part_no}." |
| ;; |
| esac |
| |
| if [ ! -c "${phy_dev}" ]; then |
| # Try to attach the volume to obtain info about it. |
| ubiattach -m "${part_no}" -d "${part_no}" |
| fi |
| |
| local max_beb_per_1024 volume_size |
| max_beb_per_1024=$(calculate_ubi_max_beb_per_1024 "${part_no}") |
| volume_size=$(get_ubi_volume_size "${part_no}") |
| |
| ubidetach -d "${part_no}" |
| ubiformat -y -e 0 "/dev/mtd${part_no}" |
| |
| # We need to attach so that we could set max beb/1024 and create a volume. |
| # After a volume is created, we don't need to specify max beb/1024 anymore. |
| ubiattach -d "${part_no}" -m "${part_no}" \ |
| --max-beb-per1024 "${max_beb_per_1024}" |
| |
| ubimkvol -s "${volume_size}" -N "${part_name}" "${phy_dev}" |
| } |
| |
| # Wipe an MTD device. |
| # $1 the device node. This must be /dev/mtdX or /dev/ubiX_0. |
| wipe_mtd_dev() { |
| local dev="$1" |
| case "${dev}" in |
| "/dev/mtd"*) |
| flash_erase "${dev}" 0 0 |
| ;; |
| "/dev/ubi"*) |
| wipe_ubi_dev "${dev}" |
| ;; |
| *) |
| echo "Do not know how to wipe ${dev}." |
| ;; |
| esac |
| } |
| |
| # Perform media-dependent wipe of the device. IS_MTD flag controls if the wipe |
| # should be an MTD wipe or a block device wipe. |
| # $1 the device, such as /dev/sda3, /dev/ubi5_0 |
| wipedev() { |
| local dev="$1" |
| if [ "${IS_MTD}" = "1" ]; then |
| wipe_mtd_dev "${dev}" |
| else |
| wipe_block_dev "${dev}" |
| fi |
| } |
| |
| # Make sure the active kernel is still bootable after being wiped. |
| # The system may be in AU state that active kernel does not have "successful" |
| # bit set to 1 (only tries). |
| ensure_bootable_kernel() { |
| local kernel_num="$1" |
| local dst="$2" |
| local active_flag="$(cgpt show -S -i "${kernel_num}" "${dst}")" |
| local priority="$(cgpt show -P -i "${kernel_num}" "${dst}")" |
| |
| if [ "${active_flag}" -lt 1 ]; then |
| cgpt add -i "${kernel_num}" "${dst}" -S 1 |
| fi |
| if [ "${priority}" -lt 1 ]; then |
| cgpt prioritize -i "${kernel_num}" "${dst}" -P 3 |
| fi |
| sync |
| } |
| |
| detect_system_config() { |
| # Root devs are /dev/sda3, /dev/ubiblock5_0. |
| # Kernel devs to go along with these are /dev/sda2, /dev/mtd4 respectively. |
| |
| # As we move factory wiping from release image to factory test image, |
| # clobber-state will be invoked directly under a tmpfs. 'rootdev' cannot |
| # report correct output under such a situation. Therefore, the output of |
| # 'rootdev' is preserved then assigned to environment variables |
| # ${ROOT_DEV}/${ROOT_DISK} for clobber-state. For other cases, the |
| # environment variables will be empty and it fallbacks to use 'rootdev'. |
| if [ -z "${ROOT_DEV}" ]; then |
| ROOT_DEV=$(rootdev -s) |
| fi |
| if [ -z "${ROOT_DISK}" ]; then |
| ROOT_DISK=$(rootdev -d -s) |
| fi |
| IS_MTD=0 |
| case "${ROOT_DISK}" in |
| "/dev/ubi"*) |
| # Special casing for NAND devices. |
| IS_MTD=1 |
| ROOT_DISK="/dev/mtd0" |
| STATE_DEV="/dev/ubi1_0" |
| # On NAND, kernel is stored on /dev/mtdX. |
| KERNEL_DEV=$(echo "${ROOT_DEV}" | tr '35' '24' | \ |
| sed -e 's/ubiblock\([0-9]*\)_0/mtd\1/') |
| ;; |
| *) |
| STATE_DEV=${ROOT_DEV%[0-9]*}1 |
| KERNEL_DEV=$(echo "${ROOT_DEV}" | tr '35' '24') |
| ;; |
| esac |
| OTHER_ROOT_DEV=$(echo "${ROOT_DEV}" | tr '35' '53') |
| OTHER_KERNEL_DEV=$(echo "${KERNEL_DEV}" | tr '24' '42') |
| KERNEL_PART_NUM=${KERNEL_DEV##[/a-z]*[/a-z]} |
| WIPE_PART_NUM=${OTHER_ROOT_DEV##[/a-z]*[/a-z]} |
| WIPE_PART_NUM=${WIPE_PART_NUM%_0} |
| # Save the option before wipe-out |
| WIPE_OPTION_FILE="${STATE_PATH}/factory_wipe_option" |
| if [ -O ${WIPE_OPTION_FILE} ]; then |
| WIPE_OPTION=$(cat ${WIPE_OPTION_FILE}) |
| else |
| WIPE_OPTION= |
| fi |
| |
| # Discover type of device holding the stateful partition; assume SSD. |
| # Since there doesn't seem to be a good way to get from a partition name |
| # to the base device name beyond simple heuristics, just find the device |
| # with the same major number but with minor 0. |
| ROTATIONAL=0 |
| MAJOR=$(stat -c %t ${STATE_DEV}) |
| for i in $(find /dev -type b); do |
| if [ "$(stat -c %t:%T $i)" = "${MAJOR}:0" ]; then |
| ROTATIONAL_PATH="/sys/block/$(basename ${i})/queue/rotational" |
| if [ -r "${ROTATIONAL_PATH}" ]; then |
| ROTATIONAL=$(cat "${ROTATIONAL_PATH}") |
| break |
| fi |
| fi |
| done |
| |
| # Sanity check root device partition number. |
| if [ "$WIPE_PART_NUM" != "3" ] && [ "$WIPE_PART_NUM" != "5" ] |
| then |
| echo "Invalid partition to wipe, $WIPE_PART_NUM (${OTHER_ROOT_DEV})" |
| exit 1 |
| fi |
| } |
| |
| wipe_rotational_drive() { |
| # If the stateful filesystem is available, do some best-effort content |
| # shredding. Since the filesystem is not mounted with "data=journal", the |
| # writes really are overwriting the block contents (unlike on an SSD). |
| if grep -q " ${STATE_PATH} " /proc/mounts ; then |
| ( |
| # Directly remove things that are already encrypted (which are also the |
| # large things), or are static from images. |
| rm -rf "${STATE_PATH}/encrypted.block" \ |
| "${STATE_PATH}/var_overlay" \ |
| "${STATE_PATH}/dev_image" |
| find "${STATE_PATH}/home/.shadow" -maxdepth 2 -type d \ |
| -name vault -print0 | |
| xargs -r0 rm -rf |
| # Shred everything else. We care about contents not filenames, so do not |
| # use "-u" since metadata updates via fdatasync dominate the shred time. |
| # Note that if the count-down is interrupted, the reset file continues |
| # to exist, which correctly continues to indicate a needed wipe. |
| find "${STATE_PATH}"/. -type f -print0 | xargs -r0 shred -fz |
| sync |
| ) & |
| fi |
| # Since the above rm/shred combo can be very fast, force a minimum of a 5 |
| # minute delay for this mode. |
| delay=300 |
| ( stty -F "${TTY}" raw -echo -cread |
| while [ "${delay}" -ge 0 ]; do |
| printf "%2d:%02d\r" $(( delay / 60 )) $(( delay % 60 )) |
| sleep 1 |
| : $(( delay -= 1 )) |
| done |
| echo |
| ) >"${TTY}" |
| wait |
| } |
| |
| wipe_stateful_partition() { |
| # Order constraints: |
| # 1. The crossystem call must happen immediately before the destruction of the |
| # stateful partition to minimize the probability of inconsistency between TPM |
| # state and presence/absence of install attributes in case of power loss. |
| # 2. The destruction of stateful must be last in the sequence in order to |
| # minimize the probability of losing the preserved files. |
| if [ "$FAST_WIPE" = "fast" ] && [ "${IS_MTD}" = "0" ]; then |
| if [ -z "${KEEPIMG}" ]; then |
| ensure_bootable_kernel "${KERNEL_PART_NUM}" "${ROOT_DISK}" |
| dd bs=4M count=1 if=/dev/zero of=${OTHER_ROOT_DEV} |
| dd bs=4M count=1 if=/dev/zero of=${OTHER_KERNEL_DEV} |
| fi |
| |
| # Clear TPM at next boot to make the TPM state consistent with (the soon to be |
| # induced) absence of install_attributes.pb. |
| crossystem clear_tpm_owner_request=1 |
| |
| # Just wipe the start of the partition and remake the fs on |
| # the stateful partition. |
| dd bs=4M count=1 if=/dev/zero of=${STATE_DEV} |
| else |
| if [ -z "${KEEPIMG}" ]; then |
| ensure_bootable_kernel "${KERNEL_PART_NUM}" "${ROOT_DISK}" |
| wipedev ${OTHER_ROOT_DEV} |
| wipedev ${OTHER_KERNEL_DEV} |
| fi |
| |
| # Clear TPM at next boot to make the TPM state consistent with (the soon to be |
| # induced) absence of install_attributes.pb. |
| crossystem clear_tpm_owner_request=1 |
| |
| # Wipe everything on the stateful partition. |
| wipedev ${STATE_DEV} |
| fi |
| } |
| |
| create_stateful_file_system() { |
| if [ "${IS_MTD}" = "1" ]; then |
| mkfs.ubifs -y -x none -R 0 "${STATE_DEV}" |
| else |
| mkfs.ext4 "${STATE_DEV}" |
| # TODO(wad) tune2fs. |
| fi |
| } |
| |
| restore_preserved_files() { |
| # If there were preserved files, restore them. |
| if [ -n "${PRESERVED_LIST}" ]; then |
| tar xfp ${PRESERVED_TAR} -C ${STATE_PATH} |
| touch /mnt/stateful_partition/unencrypted/.powerwash_completed |
| fi |
| |
| # Restore the log file |
| clobber-log --restore "${SCRIPT}" "$@" |
| } |
| |
| tag_developer_mode_flags() { |
| # Tag that we're in developer mode otherwise we may get wiped again. |
| if crossystem "devsw_boot?1" && ! crossystem "mainfw_act?recovery"; then |
| touch /mnt/stateful_partition/.developer_mode |
| fi |
| } |
| |
| board_specific_wiping() { |
| # Do any board specific wiping here. |
| # board_factory_wipe.sh will be installed by the board overlay if necessary. |
| if [ "$FACTORY_WIPE" = "factory" ]; then |
| [ -n "${FACTORY_RETURN_AFTER_WIPING}" ] && exit |
| BOARD_WIPE=/usr/sbin/board_factory_wipe.sh |
| if [ -x "${BOARD_WIPE}" ]; then |
| ${BOARD_WIPE} ${WIPE_OPTION} |
| fi |
| fi |
| } |
| |
| main() { |
| ensure_root_account |
| redirect_log_start |
| |
| preserve_files |
| detect_system_config |
| |
| # Preserve the log file |
| clobber-log --preserve "${SCRIPT}" "$@" |
| |
| # On a non-fast wipe, rotational drives take too long. Override to run them |
| # through "fast" mode, with a forced delay. Sensitive contents should already |
| # be encrypted. |
| if [ "${FAST_WIPE}" != "fast" ] && [ "${ROTATIONAL}" = "1" ]; then |
| wipe_rotational_drive |
| FAST_WIPE="fast" |
| fi |
| |
| # Make sure the stateful partition has been unmounted. |
| umount -n "${STATE_PATH}" |
| |
| wipe_stateful_partition |
| create_stateful_file_system |
| |
| # Mount the fresh image for last minute additions. |
| mount -n "${STATE_DEV}" "${STATE_PATH}" |
| |
| restore_preserved_files |
| tag_developer_mode_flags |
| |
| # Flush linux caches. |
| sync |
| |
| board_specific_wiping |
| redirect_log_stop |
| |
| /sbin/shutdown -r now |
| sleep 1d # Wait for shutdown |
| } |
| |
| main "$@" |