scripts/boot/misc-helpers.sh

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