initramfs-tools/scripts/live-helpers

   1 # live-boot helper functions, used by live-boot 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="${PATH}:/usr/lib/klibc/bin"
   7 fi
   8
   9 # handle upgrade path from old udev (using udevinfo) to
  10 # recent versions of udev (using udevadm info)
  11 if [ -x /sbin/udevadm ]
  12 then
  13         udevinfo='/sbin/udevadm info'
  14 else
  15         udevinfo='udevinfo'
  16 fi
  17
  18 old_root_overlay_label="live-rw"
  19 old_home_overlay_label="home-rw"
  20 custom_overlay_label="custom-ov"
  21 root_snapshot_label="live-sn"
  22 old_root_snapshot_label="live-sn"
  23 home_snapshot_label="home-sn"
  24 persistence_list="live-persistence.conf"
  25
  26 is_in_list_separator_helper () {
  27         local sep=${1}
  28         shift
  29         local element=${1}
  30         shift
  31         local list=${*}
  32         echo ${list} | grep -qe "^\(.*${sep}\)\?${element}\(${sep}.*\)\?$"
  33 }
  34
  35 is_in_space_sep_list () {
  36         local element=${1}
  37         shift
  38         is_in_list_separator_helper "[[:space:]]" "${element}" "${*}"
  39 }
  40
  41 is_in_comma_sep_list () {
  42         local element=${1}
  43         shift
  44         is_in_list_separator_helper "," "${element}" "${*}"
  45 }
  46
  47 sys2dev ()
  48 {
  49         sysdev=${1#/sys}
  50         echo "/dev/$($udevinfo -q name -p ${sysdev} 2>/dev/null|| echo ${sysdev##*/})"
  51 }
  52
  53 subdevices ()
  54 {
  55         sysblock=${1}
  56         r=""
  57
  58         for dev in "${sysblock}"/* "${sysblock}"
  59         do
  60                 if [ -e "${dev}/dev" ]
  61                 then
  62                         r="${r} ${dev}"
  63                 fi
  64         done
  65
  66         echo ${r}
  67 }
  68
  69 storage_devices()
  70 {
  71         black_listed_devices="${1}"
  72         white_listed_devices="${2}"
  73
  74         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "loop|ram|fd")
  75         do
  76                 fulldevname=$(sys2dev "${sysblock}")
  77
  78                 if is_in_space_sep_list ${fulldevname} ${black_listed_devices} || \
  79                         [ -n "${white_listed_devices}" ] && \
  80                         ! is_in_space_sep_list ${fulldevname} ${white_listed_devices}
  81                 then
  82                         # skip this device entirely
  83                         continue
  84                 fi
  85
  86                 for dev in $(subdevices "${sysblock}")
  87                 do
  88                         devname=$(sys2dev "${dev}")
  89
  90                         if is_in_space_sep_list ${devname} ${black_listed_devices}
  91                         then
  92                                 # skip this subdevice
  93                                 continue
  94                         else
  95                                 echo "${devname}"
  96                         fi
  97                 done
  98         done
  99 }
 100
 101 is_supported_fs ()
 102 {
 103         fstype="${1}"
 104
 105         # Validate input first
 106         if [ -z "${fstype}" ]
 107         then
 108                 return 1
 109         fi
 110
 111         # Try to look if it is already supported by the kernel
 112         if grep -q ${fstype} /proc/filesystems
 113         then
 114                 return 0
 115         else
 116                 # Then try to add support for it the gentle way using the initramfs capabilities
 117                 modprobe ${fstype}
 118                 if grep -q ${fstype} /proc/filesystems
 119                 then
 120                         return 0
 121                 # Then try the hard way if /root is already reachable
 122                 else
 123                         kmodule="/root/lib/modules/`uname -r`/${fstype}/${fstype}.ko"
 124                         if [ -e "${kmodule}" ]
 125                         then
 126                                 insmod "${kmodule}"
 127                                 if grep -q ${fstype} /proc/filesystems
 128                                 then
 129                                         return 0
 130                                 fi
 131                         fi
 132                 fi
 133         fi
 134
 135         return 1
 136 }
 137
 138 get_fstype ()
 139 {
 140         /sbin/blkid -s TYPE -o value $1 2>/dev/null
 141 }
 142
 143 where_is_mounted ()
 144 {
 145         device=${1}
 146         # return first found
 147         grep -m1 "^${device} " /proc/mounts | cut -f2 -d ' '
 148 }
 149
 150 trim_path () {
 151     # remove all unnecessary /:s in the path, including last one (except
 152     # if path is just "/")
 153     echo ${1} | sed 's|//\+|/|g' | sed 's|^\(.*[^/]\)/$|\1|'
 154 }
 155
 156 what_is_mounted_on ()
 157 {
 158         local dir="$(trim_path ${1})"
 159         grep -m1 "^[^ ]\+ ${dir} " /proc/mounts | cut -d' ' -f1
 160 }
 161
 162 chown_ref ()
 163 {
 164         local reference="${1}"
 165         shift
 166         local targets=${@}
 167         local owner=$(stat -c %u:%g "${reference}")
 168         chown -h ${owner} ${targets}
 169 }
 170
 171 chmod_ref ()
 172 {
 173         local reference="${1}"
 174         shift
 175         local targets=${@}
 176         local rights=$(stat -c %a "${reference}")
 177         chmod ${rights} ${targets}
 178 }
 179
 180 lastline ()
 181 {
 182         while read lines
 183         do
 184                 line=${lines}
 185         done
 186
 187         echo "${line}"
 188 }
 189
 190 base_path ()
 191 {
 192         testpath="${1}"
 193         mounts="$(awk '{print $2}' /proc/mounts)"
 194         testpath="$(busybox realpath ${testpath})"
 195
 196         while true
 197         do
 198                 if echo "${mounts}" | grep -qs "^${testpath}"
 199                 then
 200                         set -- $(echo "${mounts}" | grep "^${testpath}" | lastline)
 201                         echo ${1}
 202                         break
 203                 else
 204                         testpath=$(dirname $testpath)
 205                 fi
 206         done
 207 }
 208
 209 fs_size ()
 210 {
 211         # Returns used/free fs kbytes + 5% more
 212         # You could pass a block device as ${1} or the mount point as ${2}
 213
 214         dev="${1}"
 215         mountp="${2}"
 216         used="${3}"
 217
 218         if [ -z "${mountp}" ]
 219         then
 220                 mountp="$(where_is_mounted ${dev})"
 221
 222                 if [ -z "${mountp}" ]
 223                 then
 224                         mountp="/mnt/tmp_fs_size"
 225
 226                         mkdir -p "${mountp}"
 227                         mount -t $(get_fstype "${dev}") -o ro "${dev}" "${mountp}" || log_warning_msg "cannot mount -t $(get_fstype ${dev}) -o ro ${dev} ${mountp}"
 228
 229                         doumount=1
 230                 fi
 231         fi
 232
 233         if [ "${used}" = "used" ]
 234         then
 235                 size=$(du -ks ${mountp} | cut -f1)
 236                 size=$(expr ${size} + ${size} / 20 ) # FIXME: 5% more to be sure
 237         else
 238                 # free space
 239                 size="$(df -k | grep -s ${mountp} | awk '{print $4}')"
 240         fi
 241
 242         if [ -n "${doumount}" ]
 243         then
 244                 umount "${mountp}" || log_warning_msg "cannot umount ${mountp}"
 245                 rmdir "${mountp}"
 246         fi
 247
 248         echo "${size}"
 249 }
 250
 251 load_keymap ()
 252 {
 253         # Load custom keymap
 254         if [ -x /bin/loadkeys -a -r /etc/boottime.kmap.gz ]
 255         then
 256                 loadkeys /etc/boottime.kmap.gz
 257         fi
 258 }
 259
 260 setup_loop ()
 261 {
 262         local fspath=${1}
 263         local module=${2}
 264         local pattern=${3}
 265         local offset=${4}
 266         local encryption=${5}
 267         local readonly=${6}
 268
 269         # the output of setup_loop is evaluated in other functions,
 270         # modprobe leaks kernel options like "libata.dma=0"
 271         # as "options libata dma=0" on stdout, causing serious
 272         # problems therefor, so instead always avoid output to stdout
 273         modprobe -q -b "${module}" 1>/dev/null
 274
 275         udevadm settle
 276
 277         for loopdev in ${pattern}
 278         do
 279                 if [ "$(cat ${loopdev}/size)" -eq 0 ]
 280                 then
 281                         dev=$(sys2dev "${loopdev}")
 282                         options=''
 283
 284                         if [ -n "${readonly}" ]
 285                         then
 286                                 if losetup --help 2>&1 | grep -q -- "-r\b"
 287                                 then
 288                                         options="${options} -r"
 289                                 fi
 290                         fi
 291
 292                         if [ -n "${offset}" ] && [ 0 -lt "${offset}" ]
 293                         then
 294                                 options="${options} -o ${offset}"
 295                         fi
 296
 297                         if [ -z "${encryption}" ]
 298                         then
 299                                 losetup ${options} "${dev}" "${fspath}"
 300                         else
 301                                 # Loop AES encryption
 302                                 while true
 303                                 do
 304                                         load_keymap
 305
 306                                         echo -n "Enter passphrase for root filesystem: " >&6
 307                                         read -s passphrase
 308                                         echo "${passphrase}" > /tmp/passphrase
 309                                         unset passphrase
 310                                         exec 9</tmp/passphrase
 311                                         /sbin/losetup ${options} -e "${encryption}" -p 9 "${dev}" "${fspath}"
 312                                         error=${?}
 313                                         exec 9<&-
 314                                         rm -f /tmp/passphrase
 315
 316                                         if [ 0 -eq ${error} ]
 317                                         then
 318                                                 unset error
 319                                                 break
 320                                         fi
 321
 322                                         echo
 323                                         echo -n "There was an error decrypting the root filesystem ... Retry? [Y/n] " >&6
 324                                         read answer
 325
 326                                         if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
 327                                         then
 328                                                 unset answer
 329                                                 break
 330                                         fi
 331                                 done
 332                         fi
 333
 334                         echo "${dev}"
 335                         return 0
 336                 fi
 337         done
 338
 339         panic "No loop devices available"
 340 }
 341
 342 try_mount ()
 343 {
 344         dev="${1}"
 345         mountp="${2}"
 346         opts="${3}"
 347         fstype="${4}"
 348
 349         old_mountp="$(where_is_mounted ${dev})"
 350
 351         if [ -n "${old_mountp}" ]
 352         then
 353                 if [ "${opts}" != "ro" ]
 354                 then
 355                         mount -o remount,"${opts}" "${dev}" "${old_mountp}" || panic "Remounting ${dev} ${opts} on ${old_mountp} failed"
 356                 fi
 357
 358                 mount -o bind "${old_mountp}" "${mountp}" || panic "Cannot bind-mount ${old_mountp} on ${mountp}"
 359         else
 360                 if [ -z "${fstype}" ]
 361                 then
 362                         fstype=$(get_fstype "${dev}")
 363                 fi
 364                 mount -t "${fstype}" -o "${opts}" "${dev}" "${mountp}" || \
 365                 ( echo "SKIPPING: Cannot mount ${dev} on ${mountp}, fstype=${fstype}, options=${opts}" > boot.log && return 0 )
 366         fi
 367 }
 368
 369 mount_persistence_media ()
 370 {
 371         local device=${1}
 372         local probe=${2}
 373
 374         local backing="/live/persistence/$(basename ${device})"
 375
 376         mkdir -p "${backing}"
 377         local old_backing="$(where_is_mounted ${device})"
 378         if [ -z "${old_backing}" ]
 379         then
 380                 local fstype="$(get_fstype ${device})"
 381                 local mount_opts="rw,noatime"
 382                 if [ -n "${PERSISTENCE_READONLY}" ]
 383                 then
 384                         mount_opts="ro,noatime"
 385                 fi
 386                 if mount -t "${fstype}" -o "${mount_opts}" "${device}" "${backing}" >/dev/null
 387                 then
 388                         echo ${backing}
 389                         return 0
 390                 else
 391                         [ -z "${probe}" ] && log_warning_msg "Failed to mount persistence media ${device}"
 392                         rmdir "${backing}"
 393                         return 1
 394                 fi
 395         elif [ "${backing}" != "${old_backing}" ]
 396         then
 397                 if mount --move ${old_backing} ${backing} >/dev/null
 398                 then
 399                         echo ${backing}
 400                         return 0
 401                 else
 402                         [ -z "${probe}" ] && log_warning_msg "Failed to move persistence media ${device}"
 403                         rmdir "${backing}"
 404                         return 1
 405                 fi
 406         fi
 407         return 0
 408 }
 409
 410 close_persistence_media () {
 411         local device=${1}
 412         local backing="$(where_is_mounted ${device})"
 413
 414         if [ -d "${backing}" ]
 415         then
 416                 umount "${backing}" >/dev/null 2>&1
 417                 rmdir "${backing}" >/dev/null 2>&1
 418         fi
 419
 420         if is_active_luks_mapping ${device}
 421         then
 422                 /sbin/cryptsetup luksClose ${device}
 423         fi
 424 }
 425
 426 open_luks_device ()
 427 {
 428         dev="${1}"
 429         name="$(basename ${dev})"
 430         opts="--key-file=-"
 431         if [ -n "${PERSISTENCE_READONLY}" ]
 432         then
 433                 opts="${opts} --readonly"
 434         fi
 435
 436         if /sbin/cryptsetup status "${name}" >/dev/null 2>&1
 437         then
 438                 re="^[[:space:]]*device:[[:space:]]*\([^[:space:]]*\)$"
 439                 opened_dev=$(cryptsetup status ${name} 2>/dev/null | grep "${re}" | sed "s|${re}|\1|")
 440                 if [ "${opened_dev}" = "${dev}" ]
 441                 then
 442                         luks_device="/dev/mapper/${name}"
 443                         echo ${luks_device}
 444                         return 0
 445                 else
 446                         log_warning_msg "Cannot open luks device ${dev} since ${opened_dev} already is opened with its name"
 447                         return 1
 448                 fi
 449         fi
 450
 451         load_keymap
 452
 453         while true
 454         do
 455                 /lib/cryptsetup/askpass "Enter passphrase for ${dev}: " | \
 456                         /sbin/cryptsetup -T 1 luksOpen ${dev} ${name} ${opts}
 457
 458                 if [ 0 -eq ${?} ]
 459                 then
 460                         luks_device="/dev/mapper/${name}"
 461                         echo ${luks_device}
 462                         return 0
 463                 fi
 464
 465                 echo >&6
 466                 echo -n "There was an error decrypting ${dev} ... Retry? [Y/n] " >&6
 467                 read answer
 468
 469                 if [ "$(echo "${answer}" | cut -b1 | tr A-Z a-z)" = "n" ]
 470                 then
 471                         return 2
 472                 fi
 473         done
 474 }
 475
 476 get_gpt_name ()
 477 {
 478     local dev="${1}"
 479     /sbin/blkid -s PART_ENTRY_NAME -p -o value ${dev} 2>/dev/null
 480 }
 481
 482 is_gpt_device ()
 483 {
 484     local dev="${1}"
 485     [ "$(/sbin/blkid -s PART_ENTRY_SCHEME -p -o value ${dev} 2>/dev/null)" = "gpt" ]
 486 }
 487
 488 probe_for_gpt_name ()
 489 {
 490         local overlays="${1}"
 491         local snapshots="${2}"
 492         local dev="${3}"
 493
 494         local gpt_dev="${dev}"
 495         if is_active_luks_mapping ${dev}
 496         then
 497                 # if $dev is an opened luks device, we need to check
 498                 # GPT stuff on the backing device
 499                 gpt_dev=$(get_luks_backing_device "${dev}")
 500         fi
 501
 502         if ! is_gpt_device ${gpt_dev}
 503         then
 504                 return
 505         fi
 506
 507         local gpt_name=$(get_gpt_name ${gpt_dev})
 508         for label in ${overlays} ${snapshots}
 509         do
 510                 if [ "${gpt_name}" = "${label}" ]
 511                 then
 512                         echo "${label}=${dev}"
 513                 fi
 514         done
 515 }
 516
 517 probe_for_fs_label ()
 518 {
 519         local overlays="${1}"
 520         local snapshots="${2}"
 521         local dev="${3}"
 522
 523         for label in ${overlays} ${snapshots}
 524         do
 525                 if [ "$(/sbin/blkid -s LABEL -o value $dev 2>/dev/null)" = "${label}" ]
 526                 then
 527                         echo "${label}=${dev}"
 528                 fi
 529         done
 530 }
 531
 532 probe_for_file_name ()
 533 {
 534         local overlays="${1}"
 535         local snapshots="${2}"
 536         local dev="${3}"
 537
 538         local ret=""
 539         local backing="$(mount_persistence_media ${dev} probe)"
 540         if [ -z "${backing}" ]
 541         then
 542             return
 543         fi
 544
 545         for label in ${overlays}
 546         do
 547                 path=${backing}/${PERSISTENCE_PATH}${label}
 548                 if [ -f "${path}" ]
 549                 then
 550                         local loopdev=$(setup_loop "${path}" "loop" "/sys/block/loop*")
 551                         ret="${ret} ${label}=${loopdev}"
 552                 fi
 553         done
 554         for label in ${snapshots}
 555         do
 556                 for ext in squashfs cpio.gz ext2 ext3 ext4 jffs2
 557                 do
 558                         path="${PERSISTENCE_PATH}${label}.${ext}"
 559                         if [ -f "${backing}/${path}" ]
 560                         then
 561                                 ret="${ret} ${label}=${dev}:${backing}:${path}"
 562                         fi
 563                 done
 564         done
 565
 566         if [ -n "${ret}" ]
 567         then
 568                 echo ${ret}
 569         else
 570                 umount ${backing} > /dev/null 2>&1 || true
 571         fi
 572 }
 573
 574 find_persistence_media ()
 575 {
 576         # Scans devices for overlays and snapshots, and returns a whitespace
 577         # separated list of how to use them. Only overlays with a partition
 578         # label or file name in ${overlays} are returned, and ditto for
 579         # snapshots with labels in ${snapshots}.
 580         #
 581         # When scanning a LUKS device, the user will be asked to enter the
 582         # passphrase; on failure to enter it, or if no persistence partitions
 583         # or files were found, the LUKS device is closed.
 584         #
 585         # For a snapshot file the return value is ${label}=${snapdata}", where
 586         # ${snapdata} is the parameter used for try_snap().
 587         #
 588         # For all other cases (overlay/snapshot partition and overlay file) the
 589         # return value is "${label}=${device}", where ${device} a device that
 590         # can mount the content. In the case of an overlay file, the device
 591         # containing the file will remain mounted as a side-effect.
 592         #
 593         # No devices in ${black_listed_devices} will be scanned, and if
 594         # ${white_list_devices} is non-empty, only devices in it will be
 595         # scanned.
 596
 597         local overlays="${1}"
 598         local snapshots="${2}"
 599         local white_listed_devices="${3}"
 600         local ret=""
 601
 602         local black_listed_devices="$(what_is_mounted_on /live/image)"
 603
 604         for dev in $(storage_devices "${black_listed_devices}" "${white_listed_devices}")
 605         do
 606                 local result=""
 607
 608                 local luks_device=""
 609                 # Check if it's a luks device; we'll have to open the device
 610                 # in order to probe any filesystem it contains, like we do
 611                 # below. activate_custom_mounts() also depends on that any luks
 612                 # device already has been opened.
 613                 if is_in_comma_sep_list luks ${PERSISTENCE_ENCRYPTION} && \
 614                    is_luks_partition ${dev}
 615                 then
 616                         if luks_device=$(open_luks_device "${dev}")
 617                         then
 618                                 dev="${luks_device}"
 619                         else
 620                                 # skip $dev since we failed/chose not to open it
 621                                 continue
 622                         fi
 623                 elif ! is_in_comma_sep_list none ${PERSISTENCE_ENCRYPTION}
 624                 then
 625                         # skip $dev since we don't allow unencrypted storage
 626                         continue
 627                 fi
 628
 629                 # Probe for matching GPT partition names or filesystem labels
 630                 if is_in_comma_sep_list filesystem ${PERSISTENCE_STORAGE}
 631                 then
 632                         result=$(probe_for_gpt_name "${overlays}" "${snapshots}" ${dev})
 633                         if [ -n "${result}" ]
 634                         then
 635                                 ret="${ret} ${result}"
 636                                 continue
 637                         fi
 638
 639                         result=$(probe_for_fs_label "${overlays}" "${snapshots}" ${dev})
 640                         if [ -n "${result}" ]
 641                         then
 642                                 ret="${ret} ${result}"
 643                                 continue
 644                         fi
 645                 fi
 646
 647                 # Probe for files with matching name on mounted partition
 648                 if is_in_comma_sep_list file ${PERSISTENCE_STORAGE}
 649                 then
 650                         result=$(probe_for_file_name "${overlays}" "${snapshots}" ${dev})
 651                         if [ -n "${result}" ]
 652                         then
 653                                 ret="${ret} ${result}"
 654                                 continue
 655                         fi
 656                 fi
 657
 658                 # Close luks device if it isn't used
 659                 if [ -z "${result}" ] && [ -n "${luks_device}" ] && \
 660                    is_active_luks_mapping "${luks_device}"
 661                 then
 662                         /sbin/cryptsetup luksClose "${luks_device}"
 663                 fi
 664         done
 665
 666         if [ -n "${ret}" ]
 667         then
 668                 echo ${ret}
 669         fi
 670 }
 671
 672 get_mac ()
 673 {
 674         mac=""
 675
 676         for adaptor in /sys/class/net/*
 677         do
 678                 status="$(cat ${adaptor}/iflink)"
 679
 680                 if [ "${status}" -eq 2 ]
 681                 then
 682                         mac="$(cat ${adaptor}/address)"
 683                         mac="$(echo ${mac} | sed 's/:/-/g' | tr '[a-z]' '[A-Z]')"
 684                 fi
 685         done
 686
 687         echo ${mac}
 688 }
 689
 690 is_luks_partition ()
 691 {
 692         device="${1}"
 693         /sbin/cryptsetup isLuks "${device}" 1>/dev/null 2>&1
 694 }
 695
 696 is_active_luks_mapping ()
 697 {
 698         device="${1}"
 699         /sbin/cryptsetup status "${device}" 1>/dev/null 2>&1
 700 }
 701
 702 get_luks_backing_device () {
 703         device=${1}
 704         cryptsetup status ${device} 2> /dev/null | \
 705                 awk '{if ($1 == "device:") print $2}'
 706 }
 707
 708 removable_dev ()
 709 {
 710         output_format="${1}"
 711         want_usb="${2}"
 712         ret=
 713
 714         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "/(loop|ram|dm-|fd)")
 715         do
 716                 dev_ok=
 717                 if [ "$(cat ${sysblock}/removable)" = "1" ]
 718                 then
 719                         if [ -z "${want_usb}" ]
 720                         then
 721                                 dev_ok="yes"
 722                         else
 723                                 if readlink ${sysblock} | grep -q usb
 724                                 then
 725                                         dev_ok="yes"
 726                                 fi
 727                         fi
 728                 fi
 729
 730                 if [ "${dev_ok}" = "yes" ]
 731                 then
 732                         case "${output_format}" in
 733                                 sys)
 734                                         ret="${ret} ${sysblock}"
 735                                         ;;
 736                                 *)
 737                                         devname=$(sys2dev "${sysblock}")
 738                                         ret="${ret} ${devname}"
 739                                         ;;
 740                         esac
 741                 fi
 742         done
 743
 744         echo "${ret}"
 745 }
 746
 747 removable_usb_dev ()
 748 {
 749         output_format="${1}"
 750
 751         removable_dev "${output_format}" "want_usb"
 752 }
 753
 754 non_removable_dev ()
 755 {
 756         output_format="${1}"
 757         ret=
 758
 759         for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -vE "/(loop|ram|dm-|fd)")
 760         do
 761                 if [ "$(cat ${sysblock}/removable)" = "0" ]
 762                 then
 763                         case "${output_format}" in
 764                                 sys)
 765                                         ret="${ret} ${sysblock}"
 766                                         ;;
 767                                 *)
 768                                         devname=$(sys2dev "${sysblock}")
 769                                         ret="${ret} ${devname}"
 770                                         ;;
 771                         esac
 772                 fi
 773         done
 774
 775         echo "${ret}"
 776 }
 777
 778 link_files ()
 779 {
 780         # create source's directory structure in dest, and recursively
 781         # create symlinks in dest to to all files in source. if mask
 782         # is non-empty, remove mask from all source paths when
 783         # creating links (will be necessary if we change root, which
 784         # live-boot normally does (into $rootmnt)).
 785
 786         # remove multiple /:s and ensure ending on /
 787         local src_dir="$(trim_path ${1})/"
 788         local dest_dir="$(trim_path ${2})/"
 789         local src_mask="${3}"
 790
 791         # This check can only trigger on the inital, non-recursive call since
 792         # we create the destination before recursive calls
 793         if [ ! -d "${dest_dir}" ]
 794         then
 795                 log_warning_msg "Must link_files into a directory"
 796                 return
 797         fi
 798
 799         find "${src_dir}" -mindepth 1 -maxdepth 1 | while read src; do
 800                 local dest="${dest_dir}$(basename "${src}")"
 801                 if [ -d "${src}" ]
 802                 then
 803                         if [ -z "$(ls -A "${src}")" ]
 804                         then
 805                                 continue
 806                         fi
 807                         if [ ! -d "${dest}" ]
 808                         then
 809                                 mkdir -p "${dest}"
 810                                 chown_ref "${src}" "${dest}"
 811                                 chmod_ref "${src}" "${dest}"
 812                         fi
 813                         link_files "${src}" "${dest}" "${src_mask}"
 814                 else
 815                         local final_src=${src}
 816                         if [ -n "${src_mask}" ]
 817                         then
 818                                 final_src="$(echo ${final_src} | sed "s|^${src_mask}||")"
 819                         fi
 820                         rm -rf "${dest}" 2> /dev/null
 821                         ln -s "${final_src}" "${dest}"
 822                         chown_ref "${src}" "${dest}"
 823                 fi
 824         done
 825 }
 826
 827 do_union ()
 828 {
 829         local unionmountpoint="${1}"    # directory where the union is mounted
 830         local unionrw="${2}"            # branch where the union changes are stored
 831         local unionro1="${3}"           # first underlying read-only branch (optional)
 832         local unionro2="${4}"           # second underlying read-only branch (optional)
 833
 834         if [ "${UNIONTYPE}" = "aufs" ]
 835         then
 836                 rw_opt="rw"
 837                 ro_opt="rr+wh"
 838                 noxino_opt="noxino"
 839         elif [ "${UNIONTYPE}" = "unionfs-fuse" ]
 840         then
 841                 rw_opt="RW"
 842                 ro_opt="RO"
 843         else
 844                 rw_opt="rw"
 845                 ro_opt="ro"
 846         fi
 847
 848         case "${UNIONTYPE}" in
 849                 unionfs-fuse)
 850                         unionmountopts="-o cow -o noinitgroups -o default_permissions -o allow_other -o use_ino -o suid"
 851                         unionmountopts="${unionmountopts} ${unionrw}=${rw_opt}"
 852                         if [ -n "${unionro1}" ]
 853                         then
 854                                 unionmountopts="${unionmountopts}:${unionro1}=${ro_opt}"
 855                         fi
 856                         if [ -n "${unionro2}" ]
 857                         then
 858                                 unionmountopts="${unionmountopts}:${unionro2}=${ro_opt}"
 859                         fi
 860                         ( sysctl -w fs.file-max=391524 ; ulimit -HSn 16384
 861                         unionfs-fuse ${unionmountopts} "${unionmountpoint}" ) && \
 862                         ( mkdir -p /run/sendsigs.omit.d
 863                         pidof unionfs-fuse >> /run/sendsigs.omit.d/unionfs-fuse || true )
 864                         ;;
 865
 866                 overlayfs)
 867                         # XXX: can unionro2 be used? (overlayfs only handles two dirs, but perhaps they can be chained?)
 868                         # XXX: and can unionro1 be optional? i.e. can overlayfs skip lowerdir?
 869                         unionmountopts="-o noatime,lowerdir=${unionro1},upperdir=${unionrw}"
 870                         mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"
 871                         ;;
 872
 873                 *)
 874                         unionmountopts="-o noatime,${noxino_opt},dirs=${unionrw}=${rw_opt}"
 875                         if [ -n "${unionro1}" ]
 876                         then
 877                                 unionmountopts="${unionmountopts}:${unionro1}=${ro_opt}"
 878                         fi
 879                         if [ -n "${unionro2}" ]
 880                         then
 881                                 unionmountopts="${unionmountopts}:${unionro2}=${ro_opt}"
 882                         fi
 883                         mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"
 884                         ;;
 885         esac
 886 }
 887
 888 get_custom_mounts ()
 889 {
 890         # Side-effect: leaves $devices with live-persistence.conf mounted in /live/persistence
 891         # Side-effect: prints info to file $custom_mounts
 892
 893         local custom_mounts=${1}
 894         shift
 895         local devices=${@}
 896
 897         local bindings="/tmp/bindings.list"
 898         local links="/tmp/links.list"
 899         rm -rf ${bindings} ${links} 2> /dev/null
 900
 901         for device in ${devices}
 902         do
 903                 if [ ! -b "${device}" ]
 904                 then
 905                         continue
 906                 fi
 907
 908                 local device_name="$(basename ${device})"
 909                 local backing=$(mount_persistence_media ${device})
 910                 if [ -z "${backing}" ]
 911                 then
 912                         continue
 913                 fi
 914
 915                 local include_list="${backing}/${persistence_list}"
 916                 if [ ! -r "${include_list}" ]
 917                 then
 918                         continue
 919                 fi
 920
 921                 if [ -n "${DEBUG}" ] && [ -e "${include_list}" ]
 922                 then
 923                         cp ${include_list} /live/persistence/${persistence_list}.${device_name}
 924                 fi
 925
 926                 while read dir options # < ${include_list}
 927                 do
 928                         if echo ${dir} | grep -qe "^[[:space:]]*\(#.*\)\?$"
 929                         then
 930                                 # skipping empty or commented lines
 931                                 continue
 932                         fi
 933
 934                         if trim_path ${dir} | grep -q -e "^[^/]" -e "^/live\(/.*\)\?$" -e "^/\(.*/\)\?\.\.\?\(/.*\)\?$"
 935                         then
 936                                 log_warning_msg "Skipping unsafe custom mount ${dir}: must be an absolute path containing neither the \".\" nor \"..\" special dirs, and cannot be \"/live\" or any sub-directory therein."
 937                                 continue
 938                         fi
 939
 940                         local opt_source=""
 941                         local opt_link=""
 942                         for opt in $(echo ${options} | tr ',' ' ');
 943                         do
 944                                 case "${opt}" in
 945                                         source=*)
 946                                                 opt_source=${opt#source=}
 947                                                 ;;
 948                                         link)
 949                                                 opt_link="yes"
 950                                                 ;;
 951                                         union|bind)
 952                                                 ;;
 953                                         *)
 954                                                 log_warning_msg "Skipping custom mount with unkown option: ${opt}"
 955                                                 continue 2
 956                                                 ;;
 957                                 esac
 958                         done
 959
 960                         local source="${dir}"
 961                         if [ -n "${opt_source}" ]
 962                         then
 963                                 if echo ${opt_source} | grep -q -e "^/" -e "^\(.*/\)\?\.\.\?\(/.*\)\?$" && [ "${source}" != "." ]
 964                                 then
 965                                         log_warning_msg "Skipping unsafe custom mount with option source=${opt_source}: must be either \".\" (the media root) or a relative path w.r.t. the media root that contains neither comas, nor the special \".\" and \"..\" path components"
 966                                         continue
 967                                 else
 968                                         source="${opt_source}"
 969                                 fi
 970                         fi
 971
 972                         local full_source="$(trim_path ${backing}/${source})"
 973                         local full_dest="$(trim_path ${rootmnt}/${dir})"
 974                         if [ -n "${opt_link}" ]
 975                         then
 976                                 echo "${device} ${full_source} ${full_dest} ${options}" >> ${links}
 977                         else
 978                                 echo "${device} ${full_source} ${full_dest} ${options}" >> ${bindings}
 979                         fi
 980                 done < ${include_list}
 981         done
 982
 983         # We sort the list according to destination so we're sure that
 984         # we won't hide a previous mount. We also ignore duplicate
 985         # destinations in a more or less arbitrary way.
 986         [ -e "${bindings}" ] && sort -k3 -sbu ${bindings} >> ${custom_mounts} && rm ${bindings}
 987
 988         # After all mounts are considered we add symlinks so they
 989         # won't be hidden by some mount.
 990         [ -e "${links}" ] && cat ${links} >> ${custom_mounts} && rm ${links}
 991
 992         # We need to make sure that no two custom mounts have the same sources
 993         # or are nested; if that is the case, too much weird stuff can happen.
 994         local prev_source="impossible source" # first iteration must not match
 995         local prev_dest=""
 996         # This sort will ensure that a source /a comes right before a source
 997         # /a/b so we only need to look at the previous source
 998         sort -k2 -b ${custom_mounts} |
 999         while read device source dest options
1000         do
1001                 if echo ${source} | grep -qe "^${prev_source}\(/.*\)\?$"
1002                 then
1003                         panic "Two persistence mounts have the same or nested sources: ${source} on ${dest}, and ${prev_source} on ${prev_dest}"
1004                 fi
1005                 prev_source=${source}
1006                 prev_dest=${dest}
1007         done
1008 }
1009
1010 activate_custom_mounts ()
1011 {
1012         local custom_mounts="${1}" # the ouput from get_custom_mounts()
1013         local used_devices=""
1014
1015         while read device source dest options # < ${custom_mounts}
1016         do
1017                 local opt_bind="yes"
1018                 local opt_link=""
1019                 local opt_union=""
1020                 for opt in $(echo ${options} | tr ',' ' ');
1021                 do
1022                         case "${opt}" in
1023                                 bind)
1024                                         opt_bind="yes"
1025                                         unset opt_link opt_union
1026                                         ;;
1027                                 link)
1028                                         opt_link="yes"
1029                                         unset opt_bind opt_union
1030                                         ;;
1031                                 union)
1032                                         opt_union="yes"
1033                                         unset opt_bind opt_link
1034                                         ;;
1035                         esac
1036                 done
1037
1038                 if [ -n "$(what_is_mounted_on "${dest}")" ]
1039                 then
1040                         if [ "${dest}" = "${rootmnt}" ]
1041                         then
1042                                 umount "${dest}"
1043                         else
1044                                 log_warning_msg "Skipping custom mount ${dest}: $(what_is_mounted_on "${dest}") is already mounted there"
1045                                 continue
1046                         fi
1047                 fi
1048
1049                 if [ ! -d "${dest}" ]
1050                 then
1051                         # create the destination and delete existing files in
1052                         # its path that are in the way
1053                         path="/"
1054                         for dir in $(echo ${dest} | sed -e 's|/\+| |g')
1055                         do
1056                                 path=$(trim_path ${path}/${dir})
1057                                 if [ -f ${path} ]
1058                                 then
1059                                         rm -f ${path}
1060                                 fi
1061                                 if [ ! -e ${path} ]
1062                                 then
1063                                         mkdir -p ${path}
1064                                         if echo ${path} | grep -qe "^${rootmnt}/*home/[^/]\+"
1065                                         then
1066                                                 # if ${dest} is in /home try fixing proper ownership by assuming that the intended user is the first, which is usually the case
1067                                                 # FIXME: this should really be handled by live-config since we don't know for sure which uid a certain user has until then
1068                                                 chown 1000:1000 ${path}
1069                                         fi
1070                                 fi
1071                         done
1072                 fi
1073
1074                 # if ${source} doesn't exist on our persistence media
1075                 # we bootstrap it with $dest from the live filesystem.
1076                 # this both makes sense and is critical if we're
1077                 # dealing with /etc or other system dir.
1078                 if [ ! -d "${source}" ]
1079                 then
1080                         if [ -n "${PERSISTENCE_READONLY}" ]
1081                         then
1082                                 continue
1083                         elif [ -n "${opt_union}" ] || [ -n "${opt_link}" ]
1084                         then
1085                                 # unions and don't need to be bootstrapped
1086                                 # link dirs can't be bootstrapped in a sensible way
1087                                 mkdir -p "${source}"
1088                                 chown_ref "${dest}" "${source}"
1089                                 chmod_ref "${dest}" "${source}"
1090                         elif [ -n "${opt_bind}" ]
1091                         then
1092                                 # ensure that $dest is not copied *into* $source
1093                                 mkdir -p "$(dirname ${source})"
1094                                 cp -a "${dest}" "${source}"
1095                         fi
1096                 fi
1097
1098                 # XXX: If CONFIG_AUFS_ROBR is added to the Debian kernel we can
1099                 # ignore the loop below and set rofs_dest_backing=$dest
1100                 local rofs_dest_backing=""
1101                 if [ -n "${opt_link}"]
1102                 then
1103                         for d in /live/rofs/*
1104                         do
1105                                 if [ -n "${rootmnt}" ]
1106                                 then
1107                                         rofs_dest_backing="${d}/$(echo ${dest} | sed -e "s|${rootmnt}||")"
1108                                 else
1109                                         rofs_dest_backing="${d}/${dest}"
1110                                 fi
1111                                 if [ -d "${rofs_dest_backing}" ]
1112                                 then
1113                                         break
1114                                 else
1115                                         rofs_dest_backing=""
1116                                 fi
1117                         done
1118                 fi
1119
1120                 if [ -n "${opt_link}" ] && [ -z "${PERSISTENCE_READONLY}" ]
1121                 then
1122                         link_files ${source} ${dest} ${rootmnt}
1123                 elif [ -n "${opt_link}" ] && [ -n "${PERSISTENCE_READONLY}" ]
1124                 then
1125                         mkdir -p /live/persistence
1126                         local links_source=$(mktemp -d /live/persistence/links-source-XXXXXX)
1127                         chown_ref ${source} ${links_source}
1128                         chmod_ref ${source} ${links_source}
1129                         # We put the cow dir in the below strange place to
1130                         # make it absolutely certain that the link source
1131                         # has its own directory and isn't nested with some
1132                         # other custom mount (if so that mount's files would
1133                         # be linked, causing breakage.
1134                         local cow_dir="/live/overlay/live/persistence/$(basename ${links_source})"
1135                         mkdir -p ${cow_dir}
1136                         chown_ref "${source}" "${cow_dir}"
1137                         chmod_ref "${source}" "${cow_dir}"
1138                         do_union ${links_source} ${cow_dir} ${source} ${rofs_dest_backing}
1139                         link_files ${links_source} ${dest} ${rootmnt}
1140                 elif [ -n "${opt_union}" ] && [ -z "${PERSISTENCE_READONLY}" ]
1141                 then
1142                         do_union ${dest} ${source} ${rofs_dest_backing}
1143                 elif [ -n "${opt_bind}" ] && [ -z "${PERSISTENCE_READONLY}" ]
1144                 then
1145                         mount --bind "${source}" "${dest}"
1146                 elif [ -n "${opt_bind}" -o -n "${opt_union}" ] && [ -n "${PERSISTENCE_READONLY}" ]
1147                 then
1148                         # bind-mount and union mount are handled the same
1149                         # in read-only mode, but note that rofs_dest_backing
1150                         # is non-empty (and necessary) only for unions
1151                         if [ -n "${rootmnt}" ]
1152                         then
1153                                 local cow_dir="$(echo ${dest} | sed -e "s|^${rootmnt}|/live/overlay/|")"
1154                         else
1155                                 # This is happens if persistence is activated
1156                                 # post boot
1157                                 local cow_dir="/live/overlay/${dest}"
1158                         fi
1159                         if [ -e "${cow_dir}" ] && [ -z "${opt_link}" ]
1160                         then
1161                                 # If an earlier custom mount has files here
1162                                 # it will "block" the current mount's files
1163                                 # which is undesirable
1164                                 rm -rf "${cow_dir}"
1165                         fi
1166                         mkdir -p ${cow_dir}
1167                         chown_ref "${source}" "${cow_dir}"
1168                         chmod_ref "${source}" "${cow_dir}"
1169                         do_union ${dest} ${cow_dir} ${source} ${rofs_dest_backing}
1170                 fi
1171
1172                 PERSISTENCE_IS_ON="1"
1173                 export PERSISTENCE_IS_ON
1174
1175                 if echo ${used_devices} | grep -qve "^\(.* \)\?${device}\( .*\)\?$"
1176                 then
1177                         used_devices="${used_devices} ${device}"
1178                 fi
1179         done < ${custom_mounts}
1180
1181         echo ${used_devices}
1182 }
1183
1184 fix_backwards_compatibility ()
1185 {
1186         local device=${1}
1187         local dir=${2}
1188         local opt=${3}
1189
1190         if [ -n "${PERSISTENCE_READONLY}" ]
1191         then
1192                 return
1193         fi
1194
1195         local backing="$(mount_persistence_media ${device})"
1196         if [ -z "${backing}" ]
1197         then
1198                 return
1199         fi
1200
1201         local include_list="${backing}/${persistence_list}"
1202         if [ ! -r "${include_list}" ]
1203         then
1204                 echo "# persistence backwards compatibility:
1205 ${dir} ${opt},source=." > "${include_list}"
1206         fi
1207 }
1208
1209 is_mountpoint ()
1210 {
1211         directory="$1"
1212
1213         [ $(stat -fc%d:%D "${directory}") != $(stat -fc%d:%D "${directory}/..") ]
1214 }