#!/bin/sh
# bashsupport disable=BP5007
# shellcheck disable=SC2249
# shellcheck shell=sh

# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-11-12; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-ExternalRef: GIT https://git.coresecret.dev/msw/CISS.debian.live.builder.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <msw@coresecret.dev>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: GPL-3.0-or-later
# SPDX-LicenseComment: This file is part of the CISS.debian.installer.secure framework.
# SPDX-PackageName: CISS.debian.live.builder
# SPDX-Security-Contact: security@coresecret.eu

### Modified Version of the original file:
### https://salsa.debian.org/live-team/live-boot 'components/9990-overlay.sh'
### Change behavior to mount already opened ciss_rootfs.crypt (0024-ciss-crypt-squash).

#set -e

printf "\e[95m[INFO] Sourcing             : [/usr/lib/live/boot/9990-overlay.sh] \n\e[0m"

setup_unionfs ()
{
  printf "\e[95m[INFO] Starting             : [/usr/lib/live/boot/9990-overlay.sh] \n\e[0m"

  image_directory="${1}"
  rootmnt="${2}"
  addimage_directory="${3}"

  ### CISS hook: allow explicit root override ----------------------------------------------------------------------------------
  if [ -r /run/ciss-rootdev ]; then

    . /run/ciss-rootdev

    export PLAIN_ROOT=1
    export image_directory="${CDLB_MAPPER_DEV}"

    printf "\e[92m[INFO] setup_unionfs()      : [image_directory=%s]    \n\e[0m" "${image_directory}"
    printf "\e[92m[INFO] setup_unionfs()      : [rootmnt=%s]            \n\e[0m" "${rootmnt}"
    printf "\e[92m[INFO] setup_unionfs()      : [addimage_directory=%s] \n\e[0m" "${addimage_directory}"

  fi
  ### --------------------------------------------------------------------------------------------------------------------------

  # shellcheck disable=SC2086
  modprobe -q -b ${UNIONTYPE}

  if ! cut -f2 /proc/filesystems | grep -q "^${UNIONTYPE}\$"
  then
    panic "${UNIONTYPE} not available."
  fi

  croot="/run/live/rootfs"

  # Let's just mount the read-only file systems first
  rootfslist=""

  if [ -z "${PLAIN_ROOT}" ]
  then
    # Read image names from ${MODULE}.module if it exists
    # shellcheck disable=SC2153
    if [ -e "${image_directory}/filesystem.${MODULE}.module" ]
    then
      # shellcheck disable=SC2013,SC2086
      for IMAGE in $(cat ${image_directory}/filesystem.${MODULE}.module)
      do
        image_string="${image_string} ${image_directory}/${IMAGE}"
      done
    elif [ -e "${image_directory}/${MODULE}.module" ]
    then
      # shellcheck disable=SC2013,SC2086
      for IMAGE in $(cat ${image_directory}/${MODULE}.module)
      do
        image_string="${image_string} ${image_directory}/${IMAGE}"
      done
    else
      # ${MODULE}.module does not exist, create a list of images
      for FILESYSTEM in squashfs ext2 ext3 ext4 xfs jffs2 dir
      do
        for IMAGE in "${image_directory}"/*."${FILESYSTEM}"
        do
          if [ -e "${IMAGE}" ]
          then
            image_string="${image_string} ${IMAGE}"
          fi
        done
      done

      if [ -n "${addimage_directory}" ] && [ -d "${addimage_directory}" ]
      then
        for FILESYSTEM in squashfs ext2 ext3 ext4 xfs jffs2 dir
        do
          for IMAGE in "${addimage_directory}"/*."${FILESYSTEM}"
          do
            if [ -e "${IMAGE}" ]
            then
              image_string="${image_string} ${IMAGE}"
            fi
          done
        done
      fi

      # Now sort the list
      # shellcheck disable=SC2086
      image_string="$(echo ${image_string} | sed -e 's/ /\n/g' | sort )"
    fi

    # shellcheck disable=SC2086
    [ -n "${MODULETORAMFILE}" ] && image_string="${image_directory}/$(basename ${MODULETORAMFILE})"

    mkdir -p "${croot}"

    for image in ${image_string}
    do
      imagename=$(basename "${image}")

      export image devname
      maybe_break live-realpremount
      log_begin_msg "Running /scripts/live-realpremount"
      run_scripts /scripts/live-realpremount
      log_end_msg

      if [ -d "${image}" ]
      then
        # It is a plain directory: do nothing
        rootfslist="${image} ${rootfslist}"
      elif [ -f "${image}" ]
      then
        if losetup --help 2>&1 | grep -q -- "-r\b"
        then
          backdev=$(get_backing_device "${image}" "-r")
        else
          backdev=$(get_backing_device "${image}")
        fi
        fstype=$(get_fstype "${backdev}")

        case "${fstype}" in
          unknown)
            panic "Unknown file system type on ${backdev} (${image})"
            ;;

          "")
            fstype="${imagename##*.}"
            log_warning_msg "Unknown file system type on ${backdev} (${image}), assuming ${fstype}."
            ;;
        esac

        mpoint=$(trim_path "${croot}/${imagename}")
        rootfslist="${mpoint} ${rootfslist}"
        mount_options=""

        # Setup dm-verity support if a device has it supported
        hash_device="${image}.verity"
        # shellcheck disable=SC2086
        if [ -f ${hash_device} ]
        then
          log_begin_msg "Start parsing dm-verity options for ${image}"
          backdev_roothash=$(get_backing_device ${hash_device})
          verity_mount_options="-o verity.hashdevice=${backdev_roothash}"
          root_hash=$(get_dm_verity_hash ${imagename} ${DM_VERITY_ROOT_HASH})
          valid_config="true"
          case $(mount --version) in
            *verity*)
              ;;
            *)
              valid_config="false"
              log_warning_msg "mount does not have support for dm-verity. Ignoring mount options"
              ;;
          esac
          if [ -n "${root_hash}" ]
          then
            verity_mount_options="${verity_mount_options} -o verity.roothash=${root_hash}"
            # Check if the root hash is saved on disk
          elif [ -f "${image}.roothash" ]
          then
            verity_mount_options="${verity_mount_options} -o verity.roothashfile=${image}.roothash"
          else
            valid_config="false"
            log_warning_msg "'${image}' has a dm-verity hash table, but no root hash was specified ignoring"
          fi

          fec="${image}.fec"
          fec_roots="${image}.fec.roots"
          if [ -f ${fec} ] && [ -f ${fec_roots} ]
          then
            backdev_fec=$(get_backing_device ${fec})
            roots=$(cat ${fec_roots})
            verity_mount_options="${verity_mount_options} -o verity.fecdevice=${backdev_fec} -o verity.fecroots=${roots}"
          fi

          signature="${image}.roothash.p7s"
          if [ -f "${signature}" ]
          then
            verity_mount_options="${verity_mount_options} -o verity.roothashsig=${signature}"
          elif [ "${DM_VERITY_ENFORCE_ROOT_HASH_SIG}" = "true" ]
          then
            panic "dm-verity signature checking was enforced but no signature could be found for ${image}!"
          fi


          if [ -n "${DM_VERITY_ONCORRUPTION}" ]
          then
            if is_in_space_sep_list "${DM_VERITY_ONCORRUPTION}" "ignore panic restart"
            then
              verity_mount_options="${verity_mount_options} -o verity.oncorruption=${DM_VERITY_ONCORRUPTION}"
            else
              log_warning_msg "For dm-verity on corruption '${DM_VERITY_ONCORRUPTION}' was specified, but only ignore, panic or restart are supported!"
              log_warning_msg "Ignoring setting"
            fi
          fi
          if [ "${valid_config}" = "true" ]
          then
            mount_options="${mount_options} ${verity_mount_options}"
          fi
          log_end_msg "Finished parsing dm-verity options for ${image}"
        fi

        mkdir -p "${mpoint}"
        log_begin_msg "Mounting \"${image}\" on \"${mpoint}\" via \"${backdev}\""
        # shellcheck disable=SC2086
        mount -t "${fstype}" -o ro,noatime ${mount_options} "${backdev}" "${mpoint}" || panic "Can not mount ${backdev} (${image}) on ${mpoint}"
        log_end_msg
      else
        log_warning_msg "Could not find image '${image}'. Most likely it is listed in a .module file, perhaps by mistake."
      fi
    done
  else
    # We have a plain root system
    mkdir -p "${croot}/filesystem"
    log_begin_msg "Mounting \"${image_directory}\" on \"${croot}/filesystem\""
    # shellcheck disable=SC2046,SC2312
    mount -t $(get_fstype "${image_directory}") -o ro,noatime "${image_directory}" "${croot}/filesystem" || \
      panic "Can not mount ${image_directory} on ${croot}/filesystem" && \
      rootfslist="${croot}/filesystem ${rootfslist}"
    # Probably broken:
    # shellcheck disable=SC2086,SC2250
    mount -o bind ${croot}/filesystem $mountpoint
    log_end_msg
  fi

  # tmpfs file systems
  touch /etc/fstab
  mkdir -p /run/live/overlay

  # Looking for persistence devices or files
  if [ -n "${PERSISTENCE}" ] && [ -z "${NOPERSISTENCE}" ]
  then

    if [ -z "${QUICKUSBMODULES}" ]
    then
      # Load USB modules
      # shellcheck disable=SC2012
      num_block=$(ls -l /sys/block | wc -l)
      for module in sd_mod uhci-hcd ehci-hcd ohci-hcd usb-storage
      do
        # shellcheck disable=SC2086
        modprobe -q -b ${module}
      done

      udevadm trigger
      udevadm settle

      # For some reason, udevsettle does not block in this scenario,
      # so we sleep for a little while.
      #
      # See https://bugs.launchpad.net/ubuntu/+source/casper/+bug/84591
      # shellcheck disable=SC2034
      for timeout in 5 4 3 2 1
      do
        sleep 1

        # shellcheck disable=SC2012,SC2046,SC2086,SC2312
        if [ $(ls -l /sys/block | wc -l) -gt ${num_block} ]
        then
          break
        fi
      done
    fi

    # shellcheck disable=SC3043
    local whitelistdev
    whitelistdev=""
    if [ -n "${PERSISTENCE_MEDIA}" ]
    then
      case "${PERSISTENCE_MEDIA}" in
        removable)
          whitelistdev="$(removable_dev)"
          ;;

        removable-usb)
          whitelistdev="$(removable_usb_dev)"
          ;;
      esac
      if [ -z "${whitelistdev}" ]
      then
        whitelistdev="ignore_all_devices"
      fi
    fi

    # shellcheck disable=SC2086
    if is_in_comma_sep_list overlay ${PERSISTENCE_METHOD}
    then
      overlays="${custom_overlay_label}"
    fi

    # shellcheck disable=SC3043
    local overlay_devices
    overlay_devices=""
    if [ "${whitelistdev}" != "ignore_all_devices" ]
    then
      for media in $(find_persistence_media "${overlays}" "${whitelistdev}")
      do
        # shellcheck disable=SC2086
        media="$(echo ${media} | tr ":" " ")"

        for overlay_label in ${custom_overlay_label}
        do
          case ${media} in
            ${overlay_label}=*)
              device="${media#*=}"
              overlay_devices="${overlay_devices} ${device}"
              ;;
          esac
        done
      done
    fi
  elif [ -n "${NFS_COW}" ] && [ -z "${NOPERSISTENCE}" ]
  then
    # Check if there are any nfs options
    # shellcheck disable=SC2086
    if echo ${NFS_COW} | grep -q ','
    then
      # shellcheck disable=SC2086
      nfs_cow_opts="-o nolock,$(echo ${NFS_COW}|cut -d, -f2-)"
      nfs_cow=$(echo ${NFS_COW}|cut -d, -f1)
    else
      nfs_cow_opts="-o nolock"
      nfs_cow=${NFS_COW}
    fi

    if [ -n "${PERSISTENCE_READONLY}" ]
    then
      nfs_cow_opts="${nfs_cow_opts},nocto,ro"
    fi

    mac="$(get_mac)"
    if [ -n "${mac}" ]
    then
      # shellcheck disable=SC2086
      cowdevice=$(echo ${nfs_cow} | sed "s/client_mac_address/${mac}/")
      cow_fstype="nfs"
    else
      panic "unable to determine mac address"
    fi
  fi

  if [ -z "${cowdevice}" ]
  then
    cowdevice="tmpfs"
    cow_fstype="tmpfs"
    cow_mountopt="rw,noatime,mode=755,size=${OVERLAY_SIZE:-50%}"
  fi

  if [ -n "${PERSISTENCE_READONLY}" ] && [ "${cowdevice}" != "tmpfs" ]
  then
    # shellcheck disable=SC2086
    mount -t tmpfs -o rw,noatime,mode=755,size=${OVERLAY_SIZE:-50%} tmpfs "/run/live/overlay"
    # shellcheck disable=SC2086
    root_backing="/run/live/persistence/$(basename ${cowdevice})-root"
    # shellcheck disable=SC2086
    mkdir -p ${root_backing}
  else
    root_backing="/run/live/overlay"
  fi

  if [ "${cow_fstype}" = "nfs" ]
  then
    log_begin_msg \
      "Trying nfsmount ${nfs_cow_opts} ${cowdevice} ${root_backing}"
    # shellcheck disable=SC2086
    nfsmount ${nfs_cow_opts} ${cowdevice} ${root_backing} || \
      panic "Can not mount ${cowdevice} (n: ${cow_fstype}) on ${root_backing}"
  else
    # shellcheck disable=SC2086
    mount -t ${cow_fstype} -o ${cow_mountopt} ${cowdevice} ${root_backing} || \
      panic "Can not mount ${cowdevice} (o: ${cow_fstype}) on ${root_backing}"
  fi

  # shellcheck disable=SC2086
  rootfscount=$(echo ${rootfslist} |wc -w)

  rootfs=${rootfslist%% }

  if [ -n "${EXPOSED_ROOT}" ]
  then
    # shellcheck disable=SC2086
    if [ ${rootfscount} -ne 1 ]
    then
      panic "only one RO file system supported with exposedroot: ${rootfslist}"
    fi

    # shellcheck disable=SC2086
    mount -o bind ${rootfs} ${rootmnt} || \
      panic "bind mount of ${rootfs} failed"

    if [ -z "${SKIP_UNION_MOUNTS}" ]
    then
      cow_dirs='/var/tmp /var/lock /var/run /var/log /var/spool /home /var/lib/live'
    else
      cow_dirs=''
    fi
  else
    cow_dirs="/"
  fi

  for dir in ${cow_dirs}; do
    unionmountpoint=$(trim_path "${rootmnt}${dir}")
    # shellcheck disable=SC2086
    mkdir -p ${unionmountpoint}
    cow_dir=$(trim_path "/run/live/overlay${dir}")
    rootfs_dir="${rootfs}${dir}"
    # shellcheck disable=SC2086
    mkdir -p ${cow_dir}
    if [ -n "${PERSISTENCE_READONLY}" ] && [ "${cowdevice}" != "tmpfs" ]
    then
      # shellcheck disable=SC2086
      do_union ${unionmountpoint} ${cow_dir} ${root_backing} ${rootfs_dir}
    else
      # shellcheck disable=SC2086
      do_union ${unionmountpoint} ${cow_dir} ${rootfs_dir}
    fi || panic "mount ${UNIONTYPE} on ${unionmountpoint} failed with option ${unionmountopts}"
  done

  # Remove persistence depending on boot parameter
  Remove_persistence

  # Correct the permissions of /:
  chmod 0755 "${rootmnt}"

  # Correct the permission of /tmp:
  if [ -d "${rootmnt}/tmp" ]
  then
    chmod 1777 "${rootmnt}"/tmp
  fi

  # Correct the permission of /var/tmp:
  if [ -d "${rootmnt}/var/tmp" ]
  then
    chmod 1777 "${rootmnt}"/var/tmp
  fi

  # Adding custom persistence
  if [ -n "${PERSISTENCE}" ] && [ -z "${NOPERSISTENCE}" ]
  then
    # shellcheck disable=SC3043
    local custom_mounts
    custom_mounts="/tmp/custom_mounts.list"
    # shellcheck disable=SC2086
    rm -f ${custom_mounts}

    # Gather information about custom mounts from devices detected as overlays
    # shellcheck disable=SC2086
    get_custom_mounts ${custom_mounts} ${overlay_devices}

    # shellcheck disable=SC2086
    [ -n "${LIVE_BOOT_DEBUG}" ] && cp ${custom_mounts} "/run/live/persistence"

    # Now we do the actual mounting (and symlinking)
    # shellcheck disable=SC3043
    local used_overlays
    used_overlays=""
    # shellcheck disable=SC2086
    used_overlays=$(activate_custom_mounts ${custom_mounts})
    # shellcheck disable=SC2086
    rm -f ${custom_mounts}

    # Close unused overlays (e.g., due to missing $persistence_list)
    for overlay in ${overlay_devices}
    do
      # shellcheck disable=SC2086
      if echo ${used_overlays} | grep -qve "^\(.* \)\?${overlay}\( .*\)\?$"
      then
        close_persistence_media ${overlay}
      fi
    done
  fi

  printf "\e[92m[INFO] Successfully applied : [/usr/lib/live/boot/9990-overlay.sh] ... \n\e[0m"
}