mirror of https://schlomp.space/tastytea/hashboot
201 lines
7.1 KiB
Bash
Executable File
201 lines
7.1 KiB
Bash
Executable File
#!/bin/bash
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#Hashes all files in /boot to check them during early boot
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#Exit codes: 0 = success, 1 = checksum mbr mismatch, 2 = checksum /boot mismatch,
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#3 = checksum mbr/boot mismatch, 4 = not root, 5 = no hasher found, 6 = wrong usage,
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#7 = write error, 8 = dd error, 9 config file error
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###################################################################################
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# "THE HUG-WARE LICENSE" (Revision 1): #
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# xo <xo@rotce.de> and tastytea <tastytea@tastytea.de> wrote these files. As long #
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# as you retain this notice you can do whatever you want with this stuff. If we #
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# meet some day, and you think this stuff is worth it, you can give us a hug. #
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###################################################################################
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VERSION="0.7.5"
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PATH="/bin:/usr/bin:/sbin:/usr/sbin:${PATH}"
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DIGEST_FILE="/var/lib/hashboot.digest"
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DIGEST_FILE_TMP="/tmp/hashboot.digesttmp"
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LOG_FILE="/tmp/hashboot.log"
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MBR_DEVICE="/dev/sda"
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MBR_SIZE=1024
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MBR_TMP="/tmp/mbr"
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BACKUP_FILE="/var/cache/boot-backup.tar.gz"
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HASHER=""
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BOOT_MOUNTED=0
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CONFIG_FILE="/etc/hashboot.cfg"
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COUNTER=0
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#Umount /boot if we mounted it, exit with given exit code
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die ()
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{
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if [ ${BOOT_MOUNTED} -gt 0 ]
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then
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umount /boot
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fi
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[ -z "${2}" ] || echo "${2}" >&2
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exit ${1}
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}
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write_hashes ()
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{
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#Write header to ${1}
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echo "#hashboot ${VERSION} - Algorithm: $(basename ${HASHER})" > ${1}
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#Write MBR of MBR_DEVICE to ${1}
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dd if=${MBR_DEVICE} of=${MBR_TMP} bs=${MBR_SIZE}K count=1 status=noxfer || die 8
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#Write hashes of all regular files to ${1}
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${HASHER} ${MBR_TMP} >> ${1}
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find /boot -type f -exec ${HASHER} --binary {} >> ${1} +
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}
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#If we're not root: exit
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if [ ${UID} -ne 0 ]
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then
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die 4 "You have to be root"
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fi
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#If /boot is in fstab but not mounted: mount, mark as mounted
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if grep -q '/boot' /etc/fstab && ! grep -q /boot /etc/mtab
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then
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mount /boot
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BOOT_MOUNTED=1
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fi
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#Look for config file and set ${MBR_DEVICE}.
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if [ -f ${CONFIG_FILE} ]
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then
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source ${CONFIG_FILE}
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[ $? != 0 ] && die 9 "Error reading config file"
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#If not found, create one and ask for ${MBR_DEVICE}
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else
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#Create ${CONFIG_FILE} with defaults if noninterctive
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if [ -t "0" ]
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then
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echo -n "Which device contains the MBR? [/dev/sda] "
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read -r MBR_DEVICE
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[ -z "${MBR_DEVICE}" ] && MBR_DEVICE="/dev/sda"
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echo "#Device with the MBR on it" > ${CONFIG_FILE}
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echo "MBR_DEVICE=${MBR_DEVICE}" >> ${CONFIG_FILE}
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echo -n "Where should backupfile be stored?"
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read -r BACKUP_FILE
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[ -z "${BACKUP_FILE}" ] && BACKUP_FILE="/var/cache/boot-backup.tar.gz"
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echo "#Where the Backup files are stored" >> ${CONFIG_FILE}
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echo "BACKUP_FILE=${BACKUP_FILE}" >> ${CONFIG_FILE}
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else
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echo "#Device with the MBR on it" > ${CONFIG_FILE}
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echo "MBR_DEVICE=${MBR_DEVICE}" >> ${CONFIG_FILE}
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echo "#Where the Backup files are stored" >> ${CONFIG_FILE}
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echo "BACKUP_FILE=${BACKUP_FILE}" >> ${CONFIG_FILE}
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fi
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fi
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# Find out where the first partition starts and set ${MBR_SIZE} in KiB
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sectorsize=$(LC_ALL=C fdisk -l ${MBR_DEVICE} | grep '^Units' | awk '{print $8}' )
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if [ "${sectorsize}" == "=" ] # Older versions of util-linux
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then
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sectorsize=$(LC_ALL=C fdisk -l ${MBR_DEVICE} | grep '^Units' | awk '{print $9}' )
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fi
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startsector=$(LC_ALL=C fdisk -l ${MBR_DEVICE} | grep -A1 'Device' | tail -n1 | awk '{print $3}' )
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MBR_SIZE=$(expr ${sectorsize} \* ${startsector} / 1024)
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if [ ${?} != 0 ]
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then
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echo "Something went wrong. Most likely your partition table is corrupt." >&2
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die 1 "You have to recover the MBR manually by copying the mbr from ${BACKUP_FILE}"
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fi
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if [ "${1}" == "index" ]
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then
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#Try different hashers, use the most secure
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HASHER=$(/usr/bin/which sha512sum 2> /dev/null)
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test -z "${HASHER}" && HASHER=$(/usr/bin/which sha384sum 2> /dev/null)
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test -z "${HASHER}" && HASHER=$(/usr/bin/which sha256sum 2> /dev/null)
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test -z "${HASHER}" && HASHER=$(/usr/bin/which sha224sum 2> /dev/null)
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#It gets insecure below here, but better than nothing?
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test -z "${HASHER}" && HASHER=$(/usr/bin/which sha1sum 2> /dev/null)
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test -z "${HASHER}" && HASHER=$(/usr/bin/which md5sum 2> /dev/null)
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#If we found no hasher: exit
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[ -z "${HASHER}" ] && die 5 "No hash calculator found"
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#Exists ${DIGEST_FILE}, if true run du magic, else write ${DIGEST_FILE}
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if [ -f ${DIGEST_FILE} ]
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then
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#Collect mbr and /boot hashes and write to $DIGEST_FILE_TMP
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write_hashes $DIGEST_FILE_TMP
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#Compare $DIGEST_FILE_TMP against ${DIGEST_FILE} and exit, when fine. Otherwise do magic.
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if diff -q --ignore-matching-lines='^#' ${DIGEST_FILE} ${DIGEST_FILE_TMP} ;
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then
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die 0
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else
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#Compare actual hashes of MBR against saved hashes.
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if [ "$(grep ${MBR_TMP} ${DIGEST_FILE})" != "$(grep ${MBR_TMP} ${DIGEST_FILE_TMP})" ]
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then
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[ -t "0" ] && echo "at least mbr must be written."
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fi
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#Compare actual hashes of /boot against saved hashes.
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if [ "$(grep -v ${MBR_TMP} ${DIGEST_FILE})" != "$(grep -v ${MBR_TMP} ${DIGEST_FILE_TMP})" ]
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then
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[ -t "0" ] && echo "anything here, must be rewritten."
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#if interactive ask if rewrite einzeln?
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[ -t "0" ] && echo "find out which one?"
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#read z und so weiter..
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fi
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mv ${DIGEST_FILE_TMP} ${DIGEST_FILE} || die 7
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echo "List of hashes written to ${DIGEST_FILE}"
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fi
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else
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write_hashes $DIGEST_FILE
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fi
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#readconfig
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source ${CONFIG_FILE}
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#Backup of good files
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tar -czpPf ${BACKUP_FILE} ${MBR_TMP} /boot ${DIGEST_FILE}
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if [ $? == 0 ]
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then
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echo "Backup written to ${BACKUP_FILE}"
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else
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die 7 "Error writing ${BACKUP_FILE}"
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fi
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elif [ "${1}" == "check" ]
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then
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HASHER=$(head -n1 ${DIGEST_FILE} | awk '{print $5}')
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dd if=${MBR_DEVICE} of=${MBR_TMP} bs=${MBR_SIZE}K count=1 status=noxfer || die 8
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if ! $(grep ${MBR_TMP} ${DIGEST_FILE} | ${HASHER} --check --warn --quiet --strict > ${LOG_FILE})
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then
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echo " !! TIME TO PANIK: MBR WAS MODIFIED !!"
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COUNTER=$((COUNTER + 1))
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fi
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if ! $(grep -v ${MBR_TMP} ${DIGEST_FILE} | ${HASHER} --check --warn --quiet --strict >> ${LOG_FILE})
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then
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echo " !! TIME TO PANIK: AT LEAST 1 FILE WAS MODIFIED !!"
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COUNTER=$((COUNTER + 2))
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die $COUNTER
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fi
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elif [ "${1}" == "recover" ]
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then
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echo "Restoring files from backup... (type yes or no for each file)"
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#For each failed file: ask if it should be recovered from backup
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for file in $(cut -d: -f1 ${LOG_FILE})
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do
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tar -xzpPvwf ${BACKUP_FILE} ${file}
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[ $? != 0 ] && echo "Error restoring ${file} from backup, continuing" >&2
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#If the MBR is to be recovered, copy to ${MBR_DEVICE}
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if [ "${file}" == ${MBR_TMP} ]
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then
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cp ${MBR_TMP} ${MBR_DEVICE}
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[ $? != 0 ] && echo "Error restoring MBR from backup, continuing" >&2
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fi
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done
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else
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die 6 "Usage: ${0} index|check|recover"
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fi
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die 0
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