#!/bin/bash
#===============================================================================
#
# DIRECTORY:
#   /home/*/.local/share/nautilus/scripts/05c-Linux/
# OR
#   /home/*/.gnome2/nautilus-sctipts/05c-Linux/ (deprecated)
#
# FILE:
#   02b-RPi-kernel-version
#
# USAGE:
#   Right klick on a EWF_E01 image (.E01) and
#   choose this nautilus script from the context menu.
#
# OPTIONS:
#   none
#
# DESCRIPTION:
#   Extracts kernel version from kernel image.
#
# REQUIREMENTS:
#   bash, zenity, coreutils, sleuthkit, binwalk, awk, gzip and binutils
#
# BUGS:
#   ---
#
# NOTES:
#   Tested on
#   - Debian 8+
#   - Arch Linux
#
# AUTHOR:
#   Patrick Neumann, patrick@neumannsland.de
#
# COMPANY:
#   (privately)
#
# VERSION:
#   0.9 (beta)
#
# LINK TO THE MOST CURRENT VERSIONS:
#   https://
#
# CREATED:
#   13.11.2020
#
# COPYRIGHT (C):
#   2015-2020 - Patrick Neumann
#
# LICENSE:
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
#
# WARRANTY:
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# TODO:
#   ---
#
# HISTORY:
#   0.9 - Patrick Neumann - Initial (public) release
#
#===============================================================================

#-------------------------------------------------------------------------------
# Additional supported Distribution(s) (add before Library!).
#-------------------------------------------------------------------------------
SUPPORTED_OSR="arch"

#-------------------------------------------------------------------------------
# Check for library (casualscripter_nautilus-scripts_functions.sh).
#-------------------------------------------------------------------------------
readonly LIBRARY="${0%/*/*}/.casualscripter_nautilus-scripts_functions.sh"
if [ ! -f "${LIBRARY}" ] ; then
  zenity --error \
         --text \
         "ERROR: casualscripter_nautilus-scripts_functions.sh MISSING!"
  exit 1
fi

source "${LIBRARY}"

#-------------------------------------------------------------------------------
# Checks (see library "casualscripter_nautilus-scripts_functions.sh").
#-------------------------------------------------------------------------------
check_dep "${MMLS_BIN}" "sleuthkit"
check_dep "${FCAT_BIN}" "sleuthkit"
check_dep "${BINWALK_BIN}" "binwalk"
check_dep "${AWK_BIN}" "gawk"
check_dep "${DD_BIN}" "coreutils"
check_dep "${ZCAT_BIN}" "gzip"
check_dep "${STRINGS_BIN}" "binutils"
check_dep "${GREP_BIN}" "grep"
check_dep "${RM_BIN}" "coreutils"

check_ext "${SOURCE}" "[eE]01"

check_tmp

#-------------------------------------------------------------------------------
# A little bit of configuration before calling the shell script.
#-------------------------------------------------------------------------------
readonly RPI_KERNEL_VERSION="${TMP}/RPi-kernel-version.txt"

#-------------------------------------------------------------------------------
# ...
#-------------------------------------------------------------------------------

### TODO: add progress box!

OFFSET="$( ${MMLS_BIN} "${SOURCE}" | ${AWK_BIN} '/0x0c/ { print $3; }' )"
readonly OFFSET="$(( 10#"${OFFSET}" ))" # without leading zeros!

${FCAT_BIN} -o "${OFFSET}" kernel.img "${SOURCE}" > ./tmp/kernel.img

readonly SKIP="$( ${BINWALK_BIN} ./tmp/kernel.img \
                | ${AWK_BIN} '/gzip compressed data/ { print $1; }' )"

${DD_BIN} if=./tmp/kernel.img bs=1 skip="${SKIP}" status=none \
  | ${ZCAT_BIN} 2>/dev/null \
  | ${STRINGS_BIN} \
  | ${GREP_BIN} -F "Linux version" \
  > "${RPI_KERNEL_VERSION}"

${RM_BIN} ./tmp/kernel.img

#-------------------------------------------------------------------------------
# Display content of the resultfile "RPi-CPU-version.txt".
#-------------------------------------------------------------------------------
display_resultfile "${RPI_KERNEL_VERSION}"

exit 0