scripts/live-helpers

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