#!/bin/bash
# SPDX-Version: 3.0
# SPDX-CreationInfo: 2025-02-13; WEIDNER, Marc S.; <cendev@coresecret.eu>
# SPDX-ExternalRef: GIT https://cendev.eu/marc.weidner/CISS.2025.debian.installer.git
# SPDX-FileContributor: WEIDNER, Marc S.; Centurion Intelligence Consulting Agency
# SPDX-FileCopyrightText: 2024-2025; WEIDNER, Marc S.; <cendev@coresecret.eu>
# SPDX-FileType: SOURCE
# SPDX-License-Identifier: EUPL-1.2 OR LicenseRef-CCLA-1.0
# SPDX-LicenseComment: This file is part of the CISS.2025.hardened.installer framework.
# SPDX-PackageName: CISS.2025.hardened.installer
# SPDX-Security-Contact: security@coresecret.eu

###########################################################################################
# 3.6.1. Functions - installation - mount partition                                       #
###########################################################################################

###########################################################################################
# Function to generate btrfs-subvolumes.
# Globals:
#   ERR_CREAT_SUB_VOL
#   TARGET
# Arguments:
#   1: MOUNT_PATH
#   2: SUBVOLUME
###########################################################################################
create_btrfs_subvolume() {
  declare MOUNT_PATH="$1"
  declare SUBVOLUME="$2"

  btrfs subvolume create "${TARGET}${MOUNT_PATH}/${SUBVOLUME}" || {
    do_log "error" "false" "Error occurred at creation of subvolume: '${SUBVOLUME}' in: '${TARGET}${MOUNT_PATH}'."
    exit "${ERR_CREAT_SUB_VOL}"
  }
  do_log "info" "false" "Created: '${SUBVOLUME}' at: '${TARGET}${MOUNT_PATH}'."
}

###########################################################################################
# Function to create the mount path and mount the respective device on it.
# Globals:
#   ERR_MOUNTING_PATH
#   TARGET
# Arguments:
#   $1: MOUNT_PATH
#   $2: MOUNT_DEVICE
#   $3: MOUNT_OPTIONS
###########################################################################################
mount_with_dir() {
  declare MOUNT_PATH="$1"
  declare MOUNT_DEVICE="$2"
  declare MOUNT_OPTIONS="$3"

  if [[ ${MOUNT_PATH} == "/" ]]; then
    MOUNT_PATH=""
  fi

  # Create directory
  mkdir -p "${TARGET}${MOUNT_PATH}"

  # Mount routine
  mount "${MOUNT_OPTIONS:+-o $MOUNT_OPTIONS}" "${MOUNT_DEVICE}" "${TARGET}${MOUNT_PATH}" || {
    do_log "error" "false" "Error occurred at mounting '${MOUNT_DEVICE}' on: '${TARGET}${MOUNT_PATH}'."
    exit "${ERR_MOUNTING_PATH}"
  }
  do_log "info" "false" "Mounted: '${MOUNT_DEVICE}' on: '${TARGET}${MOUNT_PATH}' with: '${MOUNT_OPTIONS}'."
}

###########################################################################################
# Function for mounting all partitions for debootstrap incl. generating btrfs subvolumes.
# Globals:
#   ERR_MOUNTING_ROOT
#   ERR_NO_DEVIC_PATH
#   ERR_NO_ENCR_LABEL
#   MAP_EPHEMERAL_DEV
#   MAP_MOUNTPATH_DEV
#   MODULE_ERR
#   MODULE_TXT
#   RECIPE_STRING
#   TARGET
# Arguments:
#   None
###########################################################################################
3_6_1_functions_installation_mount_partition() {
  declare -g -x MODULE_ERR="3_6_1_functions_installation_mount_partition"
  declare -g -x MODULE_TXT="Mounting all partitions for debootstrap incl. generating btrfs subvolumes"
  do_show_header "${MODULE_TXT}"

  # Mount "/"-filesystem
  declare -r MOUNT_PATH_ROOT="/"
  if [[ -n ${MAP_MOUNTPATH_DEV[$MOUNT_PATH_ROOT]} ]]; then
    mount_with_dir "${MOUNT_PATH_ROOT}" "${MAP_MOUNTPATH_DEV[$MOUNT_PATH_ROOT]}"
  else
    do_log "error" "false" "Root-filesystem '${MOUNT_PATH_ROOT}' not found in Hashmap."
    exit "${ERR_MOUNTING_ROOT}"
  fi

  # Ensure order of "/boot" and "/boot/efi"
  declare PATH
  for PATH in "/boot" "/boot/efi"; do
    if [[ -n ${MAP_MOUNTPATH_DEV[$PATH]} ]]; then
      mount_with_dir "${PATH}" "${MAP_MOUNTPATH_DEV[$PATH]}"
    else
      do_log "info" "false" "Entry '${PATH}' not found in Hashmap."
    fi
  done

  # Mounting all remaining keys of hashmap 'MAP_MOUNTPATH_DEV'.
  declare KEY
  declare TRANSFORMED_STRING
  declare DEVICE_PATH
  declare ENCRYPTION_LABEL
  declare MATCHING_VAR

  for KEY in "${!MAP_MOUNTPATH_DEV[@]}"; do
    # Initialize variables
    DEVICE_PATH="${MAP_MOUNTPATH_DEV[${KEY}]}"

    # if KEY:VALUE equals "/dev/${DEV}${PARTITION}"
    if [[ ${DEVICE_PATH} =~ ^/dev/[a-zA-Z]+[0-9]+$   ]]; then

      TRANSFORMED_STRING=$(echo "${DEVICE_PATH}" | sed 's|/dev/|dev_|; s|\([a-zA-Z]\)\([0-9]\)|\1_\2|')

    # if KEY:VALUE equals "/dev/mapper/${ENCRYPTION_LABEL}"
    elif [[ ${DEVICE_PATH} =~ ^/dev/mapper/ ]]; then

      # Extract ENCRYPTION_LABEL
      ENCRYPTION_LABEL="${DEVICE_PATH#/dev/mapper/}"

      # Search matching variable of sourced "${PRESEED}" variable file
      MATCHING_VAR=$(declare -p | grep -oP "recipe_[^ ]+_encryption_label=${ENCRYPTION_LABEL}")

      if [[ -n ${MATCHING_VAR} ]]; then

        # Extract third, fourth and fifth part of the respective variable
        TRANSFORMED_STRING=$(echo "${MATCHING_VAR}" | sed -E 's|recipe_([^_]+_[^_]+_[^_]+)_.*|\1|')

      else

        do_log "error" "false" "No matching variable found for ENCRYPTION_LABEL='${ENCRYPTION_LABEL}'."
        exit "${ERR_NO_ENCR_LABEL}"

      fi

    else

      do_log "error" "false" "Unknown DEVICE_PATH-Format: '${DEVICE_PATH}'."
      exit "${ERR_NO_DEVIC_PATH}"

    fi

    declare BTRFS_COMPR_VAR="recipe_${RECIPE_STRING}_${TRANSFORMED_STRING}_filesystem_btrfs_compress"
    declare BTRFS_LEVEL_VAR="recipe_${RECIPE_STRING}_${TRANSFORMED_STRING}_filesystem_btrfs_level"
    declare ENCRYPTION_LABEL_VAR="recipe_${RECIPE_STRING}_${TRANSFORMED_STRING}_encryption_label"
    declare FILESYSTEM_LABEL_VAR="recipe_${RECIPE_STRING}_${TRANSFORMED_STRING}_filesystem_label"
    declare FILESYSTEM_VERSION_VAR="recipe_${RECIPE_STRING}_${TRANSFORMED_STRING}_filesystem_version"
    declare MOUNT_OPTIONS_VAR="recipe_${RECIPE_STRING}_${TRANSFORMED_STRING}_mount_options"
    declare MOUNT_SUBVOLUME_VAR="recipe_${RECIPE_STRING}_${TRANSFORMED_STRING}_mount_subvolume"

    declare BTRFS_COMPR=${!BTRFS_COMPR_VAR}
    declare BTRFS_LEVEL=${!BTRFS_LEVEL_VAR}
    declare ENCRYPTION_LABEL=${!ENCRYPTION_LABEL_VAR}
    declare FILESYSTEM_LABEL=${!FILESYSTEM_LABEL_VAR}
    declare FILESYSTEM_VERSION=${!FILESYSTEM_VERSION_VAR}
    declare MOUNT_OPTIONS=${!MOUNT_OPTIONS_VAR}
    declare MOUNT_SUBVOLUME=${!MOUNT_SUBVOLUME_VAR}

    # Skip already mounted paths ("/", "/boot", "/boot/efi")
    if [[ ${KEY} == "/" || ${KEY} == "/boot" || ${KEY} == "/boot/efi" ]]; then
      continue
    fi

    if [[ ${FILESYSTEM_VERSION,,} == "btrfs" ]]; then

      declare BTRFS_OPTIONS="compress=${BTRFS_COMPR}:${BTRFS_LEVEL}"
      mount_with_dir "${KEY}" "${DEVICE_PATH}" "${BTRFS_OPTIONS}"
      [[ -n ${MOUNT_SUBVOLUME} ]] && create_btrfs_subvolume "${KEY}" "${MOUNT_SUBVOLUME}"

    elif   [[ ${FILESYSTEM_VERSION,,} == "ext4" ]]; then

      mount_with_dir "${KEY}" "${DEVICE_PATH}"

    else

      do_log "error" "false" "No valid filesystem: '${FILESYSTEM_VERSION}' found for ${KEY}."

    fi

  done

  # Reminder: MAP_EPHEMERALLABEL_DEV["${MOUNT_PATH}"]="/dev/${DEV}${PARTITION}"
  # Mounting remaining entries of hashmap 'MAP_EPHEMERALLABEL_DEV'.
  declare KEY
  declare TRANSFORMED_STRING
  declare DEVICE_PATH

  for KEY in "${!MAP_EPHEMERAL_DEV[@]}"; do
    # Initialize variables
    DEVICE_PATH="${MAP_EPHEMERAL_DEV[${KEY}]}"

    # if KEY:VALUE equals "/dev/${DEV}${PARTITION}"
    if [[ ${DEVICE_PATH} =~ ^/dev/[a-zA-Z]+[0-9]+$   ]]; then

      TRANSFORMED_STRING=$(echo "${DEVICE_PATH}" | sed 's|/dev/|dev_|; s|\([a-zA-Z]\)\([0-9]\)|\1_\2|')

    # if KEY:VALUE equals "/dev/mapper/${ENCRYPTION_LABEL}"
    elif [[ ${DEVICE_PATH} =~ ^/dev/mapper/ ]]; then

      # Extract ENCRYPTION_LABEL
      ENCRYPTION_LABEL="${DEVICE_PATH#/dev/mapper/}"

      # Search matching variable of sourced "${PRESEED}" variable file
      MATCHING_VAR=$(declare -p | grep -oP "recipe_[^ ]+_encryption_label=${ENCRYPTION_LABEL}")

      if [[ -n ${MATCHING_VAR} ]]; then

        # Extract third, fourth and fifth part of the respective variable
        TRANSFORMED_STRING=$(echo "${MATCHING_VAR}" | sed -E 's|recipe_[^_]+_(dev_[^_]+_[^_]+)_.*|\1|')

      else

        do_log "error" "false" "No matching variable found for ENCRYPTION_LABEL='${ENCRYPTION_LABEL}'."
        exit "${ERR_NO_ENCR_LABEL}"

      fi

    else

      do_log "error" "false" "Unknown DEVICE_PATH-Format: '${DEVICE_PATH}'."
      exit "${ERR_NO_DEVIC_PATH}"

    fi

    declare ENCRYPTION_LABEL_VAR="recipe_${RECIPE_STRING}_${TRANSFORMED_STRING}_encryption_label"
    declare FILESYSTEM_LABEL_VAR="recipe_${RECIPE_STRING}_${TRANSFORMED_STRING}_filesystem_label"
    declare MOUNT_OPTIONS_VAR="recipe_${RECIPE_STRING}_${TRANSFORMED_STRING}_mount_options"
    declare ENCRYPTION_LABEL=${!ENCRYPTION_LABEL_VAR}
    declare FILESYSTEM_LABEL=${!FILESYSTEM_LABEL_VAR}
    declare MOUNT_OPTIONS=${!MOUNT_OPTIONS_VAR}

    if [[ ${KEY} == "SWAP" ]]; then

      cryptsetup open --type plain --key-file /dev/random \
        --offset 2048 --cipher aes-xts-plain64 --key-size 512 \
        --sector-size 4096 "/dev/disk/by-label/${FILESYSTEM_LABEL}" "${ENCRYPTION_LABEL}"
      mkswap "/dev/mapper/${ENCRYPTION_LABEL}"
      swapon "/dev/mapper/${ENCRYPTION_LABEL}"
      do_log "info" "false" "Mounted: '${KEY}' on: '/dev/mapper/${ENCRYPTION_LABEL}'."

    elif [[ ${KEY} == "/tmp" ]]; then

      cryptsetup open --type plain --key-file /dev/random \
        --offset 2048 --cipher aes-xts-plain64 --key-size 512 \
        --sector-size 4096 "/dev/disk/by-label/${FILESYSTEM_LABEL}" "${ENCRYPTION_LABEL}"
      mkdir -p "${TARGET}/tmp"
      mount "${MOUNT_OPTIONS:+-o $MOUNT_OPTIONS}" "/dev/mapper/${ENCRYPTION_LABEL}" "${TARGET}/tmp"
      do_log "info" "false" "Mounted: '${KEY}' on: '/dev/mapper/${ENCRYPTION_LABEL}'."

    else
        do_log "warn" "false" "Ephemeral configuration for ${KEY} is not valid or disabled."
    fi

  done

  do_log "info" "false" "All devices of 'MAP_MOUNTPATH_DEV' and 'MAP_EPHEMERALLABEL_DEV' successfully mounted."

  do_show_footer "${MODULE_TXT}"
}
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