#!/bin/sh
# Copyright (C) 2006,2007 Krzysztof Kozlowski
#   License: GNU General Public License version 2
#            http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# version 2 as published by the Free Software Foundation.
#
# 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.
#
#
# Homepage: http://www.kozik.net.pl
#
# Last change: 06.12.2007
#
# fsck loop-file. Loop-file can be encrypted, but currently only AES256 is supported.
# If encryption is used script will try to load modules aes-i586 and cryptoloop.
#
#

. /home/kozik/bin/kozik_functions

usage () {
  echo "Usage: $(basename $0) [--cryptoloop-aes|--dm-crypt-aes] file"
  exit 127
}

if [ $# -lt 1 ]; then
  usage
fi

# Mangle with arguments:
LOSETUP_OPTIONS=""
count=1
CRYPTOLOOP_AES=0
DMCRYPT_AES=0
for arg in "$@"
do
  if [ $count -eq $# ]; then
    FILE=$arg
  elif [ "$arg" == "--cryptoloop-aes" ]; then
    CRYPTOLOOP_AES=1
  elif [ "$arg" == "--dm-crypt-aes" ]; then
    DMCRYPT_AES=1
  fi
  let "count+=1"
done

if [ $CRYPTOLOOP_AES -eq 1 ] && [ $DMCRYPT_AES -eq 1 ]; then
  usage
fi
test -f "${FILE}" || die "File to mount not found!"

DEVS="/dev/loop" # Maybe you want /dev/cloop?

if [ $CRYPTOLOOP_AES -eq 1 ]; then
  LOSETUP_OPTIONS="-e AES256" # FIXME - allow choosing different AES cipher
  modprobe aes-i586
  modprobe cryptoloop
elif [ $DMCRYPT_AES -eq 1 ]; then
  LOSETUP_OPTIONS=""
  modprobe aes-i586
  modprobe dm-crypt
  DM_NODE_NAME=`basename "${FILE}"`
  CRYPT_NODE_NAME="${DM_NODE_NAME}.crypt"
  cryptsetup status $CRYPT_NODE_NAME | grep "is active" && die "$CRYPT_NODE_NAME is currently used. I will not proceed."
fi


# Main program
LOOP_DEV=`find_free_loop_dev`
if [ "$LOOP_DEV" != "" ]; then
  echo "Using loop device: $LOOP_DEV"
  if [ $CRYPTOLOOP_AES -eq 1 ]; then
    losetup $LOSETUP_OPTIONS "$LOOP_DEV" "$FILE" || die "Could not losetup ${LOOP_DEV}"
    fsck "$LOOP_DEV"
  elif [ $DMCRYPT_AES -eq 1 ]; then
    losetup $LOSETUP_OPTIONS "$LOOP_DEV" "$FILE" || die "Could not losetup ${LOOP_DEV}"
    cryptsetup -c aes create "${CRYPT_NODE_NAME}" "${LOOP_DEV}" || die "Could not cryptsetup ${DM_NODE_NAME}.crypt"
    fsck "/dev/mapper/${DM_NODE_NAME}.crypt"
    sync && sync && sync
    sleep 1
    cryptsetup remove "${CRYPT_NODE_NAME}"
  fi
  losetup -d "$LOOP_DEV"
  exit 0
else
  echo "Could not find any free loop device!"
  exit 2
fi