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