#!/bin/sh
# PLD RescueCD modifier 0.1
# (c) areq@pld.org.pl

ISOSIZE=53196800

usage ()
{
echo Usage:
echo isomod -i isofile [-o isofile.out] [-f local_file] [-d unpack_dir] [-tail\|-dd]
echo 
echo "Example:"
echo "  isomod -i rescue.iso -f local.tar.bz -o rescue_new.iso"
echo "   Add local.tar.bz to rescue.iso and save as rescue_new.iso."
echo 
echo "  isomod -i rescue.iso -d files"
echo "   Save all files from rescue.iso to direcory files."
echo
echo "  isomod -i rescue.iso -d files -dd"
echo "   Save all files from rescue.iso to direcory files use dd - slow."
echo
echo "  isomod -d files -o rescue_new.iso"
echo "   Create rescue_new.iso from directory files."
echo
exit 1
}

un_tail ()
{
 tail -c $(($ISOSIZE-$2)) $ISO | head -c $3 > $1
}
un_dd ()
{
 dd if=$ISO of=$1 skip=$2 count=$3 bs=1 2> /dev/null
}

unpack ()
{
 mkdir -p $(dirname $1)
 un_$METHOD $*
 echo "$4  $1" | md5sum -c
}
mkiso ()
{
LOG=`mktemp /tmp/isomod.$$.XXXXXX` || exit 1
echo Save log to $LOG.
mkisofs -v -L -R -D -b boot/isolinux/isolinux.bin -c boot/isolinux/boot.catalog \
-no-emul-boot -boot-load-size 4 -boot-info-table -log-file $LOG -o $2 $1
echo Saved $2.
}

unpack_all ()
{
while read file start len md5; 
do 
 unpack $DIR/$file $start $len $md5
done << __EOT__
rescue.sqf 86016 51171328 52d7ab8a3cf4b4a14eef00939879c427
boot/ElTorito.img.gz 51259392 17131 f49c4f2db855d2d482d399caacd2d3c3
boot/README 51369984 744 872b6e50b511b7a96c56047ef3ea851b
boot/boot.bat 51257344 83 5a6fc33959be2620bb28c189c916123d
boot/floppy.img.gz 51277824 25489 d9769a18460b3fb4fc7b276395145a75
boot/gzip.exe 51304448 39910 468c7ede345425ea4b7db63360084743
boot/isolinux/boot.msg 51372032 1586 48c9f0c6bf336d45e3822720f2a40496
boot/isolinux/help.msg 51374080 1385 5d04177a35d43cb139e77391233c05f7
boot/isolinux/isolinux.bin 75776 9844 b2175e7eb3eb0d94e9ab3c2810188e3f
boot/isolinux/isolinux.cfg 51931136 1192 c448476c7b24c849827a02d4c0a83119
boot/isolinux/memtest 51933184 81892 f0c05b8930cbf2a91b59552612561518
boot/isolinux/vmlinuz 52015104 873984 bbef5a8f9ba58d7408c8bc58e6a55fd4
boot/isolinux/initrd.ide 51376128 553984 4e8f974b51a103e9caa0fe5b1c7891e7
boot/loadlin.exe 51349504 10137 b6f43a2a7dce1e39de2043a873ce4b55
boot/rawrite2.exe 51359744 9999 290c58e46c6c28145fb9c4912932cd81
__EOT__
}

echo PLD RescueCD modifier 0.1
echo

[ $# -eq 0 ] && usage

METHOD=tail
RMOUT=0
while [ $# -ge 1 ]; do
  case $1 in
    -i)     shift;  ISO=$1 ;;
    -o)     shift;  OUT=$1 ;;
    -d)     shift;  DIR=$1 ;;
    -f)     shift;  FILE=$1 ;;
    -dd)    METHOD=dd;;
    -tail)  METHOD=tail ;;
    *)     usage ;;
  esac
  shift
done

if [ "$DIR" = "" ] 
then
 DIR=`mktemp -d /tmp/$$.XXXXXX` || exit 1
 RMOUT=1
fi

if [ "$FILE" != "" ] 
then
 echo Checking $FILE...
 [ -f "$FILE" ] || exit 1
 [ "$(head -c 3 "$FILE")" = "BZh" ] || exit 1
 bzip2 -dc "$FILE" | tar tf - | sed 's/\.\///' |\
 	grep -v -q -E "^$|^etc|^tmp|^var|^root|^home"
 if [ $? == 0 ]; then
      echo -e "PANIC! $FILE contains invalid paths! quitting.\n"
      exit 1
 fi
 echo OK
fi

if [ -n "$ISO" ]
then
  if ! [ -f "$ISO" ] 
  then
    echo File $ISO not found!
  exit 1
  fi
  if ! [ $(stat -c %s $ISO) -eq $ISOSIZE ]
  then
    echo Bad iso file $ISO!
  exit 1
  fi
  unpack_all
fi

if [ -n "$FILE" ] ; then
  rm -fr $DIR/local.tar.bz2
  cp $FILE $DIR/local.tar.bz2
  echo Add $FILE.
fi

[ -n "$OUT" ] && mkiso $DIR $OUT

[ $RMOUT -eq 1 ] && rm -fr $DIR