scripts/live-helpers

   1 # live-initramfs helper functions, used by live-initramfs on boot and by live-snapshot
   2
   3 if [ ! -x "/bin/fstype" ]
   4 then
   5         # klibc not in path -> not in initramfs
   6         export PATH="${PATH}:/usr/lib/klibc/bin"
   7 fi
   8
   9 sys2dev ()
  10 {
  11         sysdev=${1#/sys}
  12         echo "/dev/$(udevinfo -q name -p ${sysdev} 2>/dev/null|| echo ${sysdev##*/})"
  13 }
  14
  15 subdevices ()
  16 {
  17         sysblock=${1}
  18         r=""
  19
  20         for dev in "${sysblock}" "${sysblock}"/*
  21         do
  22                 if [ -e "${dev}/dev" ]
  23                 then
  24                         r="${r} ${dev}"
  25                 fi
  26         done
  27
  28         echo ${r}
  29 }
  30
  31 is_supported_fs ()
  32 {
  33         fstype="${1}"
  34
  35         # Validate input first
  36         if [ -z "${fstype}" ]
  37         then
  38                 return 1
  39         fi
  40
  41         # Try to look if it is already supported by the kernel
  42         if grep -q ${fstype} /proc/filesystems
  43         then
  44                 return 0
  45         else
  46                 # Then try to add support for it the gentle way using the initramfs capabilities
  47                 modprobe ${fstype}
  48                 if grep -q ${fstype} /proc/filesystems
  49                 then
  50                         return 0
  51                 # Then try the hard way if /root is already reachable
  52                 else
  53                         kmodule="/root/lib/modules/`uname -r`/${fstype}/${fstype}.ko"
  54                         if [ -e "${kmodule}" ]
  55                         then
  56                                 insmod "${kmodule}"
  57                                 if grep -q ${fstype} /proc/filesystems
  58                                 then
  59                                         return 0
  60                                 fi
  61                         fi
  62                 fi
  63         fi
  64
  65         return 1
  66 }
  67
  68 get_fstype ()
  69 {
  70         local FSTYPE
  71         local FSSIZE
  72
  73         # fstype misreports LUKS devices
  74         if is_luks "${1}"
  75         then
  76             /lib/udev/vol_id -t ${1} 2>/dev/null
  77             return
  78         fi
  79
  80         eval $(fstype ${1} 2>/dev/null)
  81
  82         if [ "${FSTYPE}" != "unknown" ]
  83         then
  84                 echo ${FSTYPE}
  85                 return 0
  86         fi
  87
  88         /lib/udev/vol_id -t ${1} 2>/dev/null
  89 }
  90
  91 where_is_mounted ()
  92 {
  93         device=${1}
  94
  95         if grep -q "^${device} " /proc/mounts
  96         then
  97                 # return the first found
  98                 grep "^${device} " /proc/mounts | cut -f2 -d ' '
  99         fi
 100 }
 101
 102 lastline ()
 103 {
 104         while read lines
 105         do
 106                 line=${lines}
 107         done
 108
 109         echo "${line}"
 110 }
 111
 112 base_path ()
 113 {
 114         testpath="${1}"
 115         mounts="$(awk '{print $2}' /proc/mounts)"
 116         testpath="$(busybox realpath ${testpath})"
 117
 118         while true
 119         do
 120                 if echo "${mounts}" | grep -qs "^${testpath}"
 121                 then
 122                         set -- $(echo "${mounts}" | grep "^${testpath}" | lastline)
 123                         echo ${1}
 124                         break
 125                 else
 126                         testpath=$(dirname $testpath)
 127                 fi
 128         done
 129 }
 130
 131 fs_size ()
 132 {
 133         # Returns used/free fs kbytes + 5% more
 134         # You could pass a block device as ${1} or the mount point as ${2}
 135
 136         dev="${1}"
 137         mountp="${2}"
 138         used="${3}"
 139
 140         if [ -z "${mountp}" ]
 141         then
 142                 mountp="$(where_is_mounted ${dev})"
 143
 144                 if [ -z "${mountp}" ]
 145                 then
 146                         mountp="/mnt/tmp_fs_size"
 147
 148                         mkdir -p "${mountp}"
 149                         mount -t $(get_fstype "${dev}") -o ro "${dev}" "${mountp}" || log_warning_msg "cannot mount -t $(get_fstype ${dev}) -o ro ${dev} ${mountp}"
 150
 151                         doumount=1
 152                 fi
 153         fi
 154
 155         if [ "${used}" = "used" ]
 156         then
 157                 size=$(du -ks ${mountp} | cut -f1)
 158                 size=$(expr ${size} + ${size} / 20 ) # FIXME: 5% more to be sure
 159         else
 160                 # free space
 161                 size="$(df -k | grep -s ${mountp} | awk '{print $4}')"
 162         fi
 163
 164         if [ -n "${doumount}" ]
 165         then
 166                 umount "${mountp}" || log_warning_msg "cannot umount ${mountp}"
 167                 rmdir "${mountp}"
 168         fi
 169
 170         echo "${size}"
 171 }
 172
 173 load_keymap ()
 174 {
 175         # Load custom keymap
 176         if [ -x /bin/loadkeys -a -r /etc/boottime.kmap.gz ]
 177         then
 178                 loadkeys /etc/boottime.kmap.gz
 179         fi
 180 }
 181
 182 setup_loop ()
 183 {
 184         local fspath=${1}
 185         local module=${2}
 186         local pattern=${3}
 187         local offset=${4}
 188         local encryption=${5}
 189         local readonly=${6}
 190
 191         modprobe -q -b "${module}"
 192
 193         if [ -x /sbin/udevadm ]
 194         then
 195                 # lenny
 196                 udevadm settle
 197         else
 198                 # etch
 199                 udevsettle
 200         fi
 201
 202         for loopdev in ${pattern}
 203         do
 204                 if [ "$(cat ${loopdev}/size)" -eq 0 ]
 205                 then
 206                         dev=$(sys2dev "${loopdev}")
 207                         options=''
 208
 209                         if [ -n ${readonly} ]
 210                         then
 211                                 if losetup --help 2>&1 | grep -q -- "-r\b"
 212                                 then
 213                                         options="${options} -r"
 214                                 fi
 215                         fi
 216
 217                         if [ 0 -lt "${offset}" ]
 218                         then
 219                                 options="${options} -o ${offset}"
 220                         fi
 221
 222                         if [ -z "${encryption}" ]
 223                         then
 224                                 losetup ${options} "${dev}" "${fspath}"
 225                         else
 226                                 # Loop AES encryption
 227                                 while true
 228                                 do
 229                                         load_keymap
 230
 231                                         echo -n "Enter passphrase for root filesystem: " >&6
 232                                         read -s passphrase
 233                                         echo "${passphrase}" > /tmp/passphrase
 234                                         unset passphrase
 235                                         exec 9</tmp/passphrase
 236                                         /sbin/losetup ${options} -e "${encryption}" -p 9 "${dev}" "${fspath}"
 237                                         error=${?}
 238                                         exec 9<&-
 239                                         rm -f /tmp/passphrase
 240
 241                                         if [ 0 -eq ${error} ]
 242                                         then
 243                                                 unset error
 244                                                 break
 245                                         fi
 246
 247                                         echo
 248                                         echo -n "There was an error decrypting the root filesystem ... Retry? [Y/n] " >&6
 249                                         read answer
 250
 251                                         if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
 252                                         then
 253                                                 unset answer
 254                                                 break
 255                                         fi
 256                                 done
 257                         fi
 258
 259                         echo "${dev}"
 260                         return 0
 261                 fi
 262         done
 263
 264         panic "No loop devices available"
 265 }
 266
 267 try_mount ()
 268 {
 269         dev="${1}"
 270         mountp="${2}"
 271         opts="${3}"
 272         fstype="${4}"
 273
 274         old_mountp="$(where_is_mounted ${dev})"
 275
 276         if [ -n "${old_mountp}" ]
 277         then
 278                 if [ "${opts}" != "ro" ]
 279                 then
 280                         mount -o remount,"${opts}" "${dev}" "${old_mountp}" || panic "Remounting ${dev} ${opts} on ${old_mountp} failed"
 281                 fi
 282
 283                 mount -o bind "${old_mountp}" "${mountp}" || panic "Cannot bind-mount ${old_mountp} on ${mountp}"
 284         else
 285                 if [ -z "${fstype}" ]
 286                 then
 287                         fstype=$(get_fstype "${dev}")
 288                 fi
 289                 mount -t "${fstype}" -o "${opts}" "${dev}" "${mountp}" || panic "Cannot mount ${dev} on ${mountp}, fstype=${fstype}, options=${opts}"
 290         fi
 291 }
 292
 293 find_cow_device ()
 294 {
 295         # Returns a device containing a partition labeled "${pers_label}" or containing a file named the same way
 296         #  in the latter case the partition containing the file is left mounted
 297         #  if is not in black_listed_devices
 298         pers_label="${1}"
 299         cow_backing="/${pers_label}-backing"
 300         black_listed_devices="${2}"
 301
 302         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop | grep -v ram | grep -v fd)
 303         do
 304                 for dev in $(subdevices "${sysblock}")
 305                 do
 306                         devname=$(sys2dev "${dev}")
 307
 308                         if echo "${black_listed_devices}" | grep -q "${devname}"
 309                         then
 310                                 # skip this device enterely
 311                                 break
 312                         fi
 313
 314                         if [ "$(/lib/udev/vol_id -l ${devname} 2>/dev/null)" = "${pers_label}" ]
 315                         then
 316                                 echo "${devname}"
 317                                 return
 318                         fi
 319
 320                         if [ "${PERSISTENT}" = "nofiles" ]
 321                         then
 322                                 # do not mount the device to find for image files
 323                                 # just skip this
 324                                 break
 325                         fi
 326
 327                         case "$(get_fstype ${devname})" in
 328                                 vfat|ext2|ext3|jffs2)
 329                                         mkdir -p "${cow_backing}"
 330                                         if ! try_mount "${devname}" "${cow_backing}" "rw"
 331                                         then
 332                                                 break
 333                                         fi
 334
 335                                         if [ -f "${cow_backing}/${pers_label}" ]
 336                                         then
 337                                                 echo $(setup_loop "${cow_backing}/${pers_label}" "loop" "/sys/block/loop*")
 338                                                 return 0
 339                                         else
 340                                                 umount ${cow_backing}
 341                                         fi
 342                                         ;;
 343                                 *)
 344                                         ;;
 345                         esac
 346                 done
 347         done
 348 }
 349
 350 find_files ()
 351 {
 352         # return the a string composed by device name, mountpoint an the first of ${filenames} found on a supported partition
 353         # FIXME: merge with above function
 354
 355         filenames="${1}"
 356         snap_backing="/snap-backing"
 357         black_listed_devices="${2}"
 358
 359         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop | grep -v ram | grep -v fd)
 360         do
 361                 for dev in $(subdevices "${sysblock}")
 362                 do
 363                         devname=$(sys2dev "${dev}")
 364                         devfstype="$(get_fstype ${devname})"
 365
 366                         if echo "${black_listed_devices}" | grep -q "${devname}"
 367                         then
 368                                 # skip this device enterely
 369                                 break
 370                         fi
 371
 372                         if is_supported_fs ${devfstype}
 373                         then
 374                                 mkdir -p "${snap_backing}"
 375
 376                                 if try_mount "${devname}" "${snap_backing}" "ro" "${devfstype}"
 377                                 then
 378                                         for filename in ${filenames}
 379                                         do
 380                                                 if [ -f "${snap_backing}/${filename}" ]
 381                                                 then
 382                                                         echo "${devname} ${snap_backing} ${filename}"
 383                                                         umount ${snap_backing}
 384                                                         return 0
 385                                                 fi
 386                                         done
 387                                 fi
 388
 389                                 umount ${snap_backing}
 390                         fi
 391                 done
 392         done
 393 }
 394
 395 get_mac ()
 396 {
 397         mac=""
 398
 399         for adaptor in /sys/class/net/*
 400         do
 401                 status="$(cat ${adaptor}/iflink)"
 402
 403                 if [ "${status}" -eq 2 ]
 404                 then
 405                         mac="$(cat ${adaptor}/address)"
 406                         mac="$(echo ${mac} | sed 's/:/-/g' | tr '[a-z]' '[A-Z]')"
 407                 fi
 408         done
 409
 410         echo ${mac}
 411 }
 412
 413 is_luks()
 414 {
 415     devname="${1}"
 416     if [ -x /sbin/cryptsetup ]
 417     then
 418         /sbin/cryptsetup isLuks "${devname}" 2>/dev/null || ret=${?}
 419         return ${ret}
 420     else
 421         return 1
 422     fi
 423
 424 }