#!/bin/ash

# Functions library :: for Linux Live scripts 5.x.y
# Author: Tomas M. <http://www.linux-live.org>
#

# ===========================================================
# variables
# ===========================================================

# linux live flag to fstab, if fstab line doesn't contain it,
# never remove it from fstab automatically (user added it)
FSTABLLFLAG="# AutoUpdate"

# ===========================================================
# user interface functions
# ===========================================================

# echolog
# $1 = text to show and to write to /var/log/messages
#
echolog()
{
   echo "LIVECD:" "$@" >>/var/log/livedbg
   echo "$@"
}

# debug
# commands executed when debug boot parameter is present
#
debug()
{
   echo
   echo "====="
   echo ": Debugging started. Here is the root shell for you."
   echo ": Type your desired command or hit Ctrl+D to continue booting."
   echo
   ash
}

# header
# $1 = text to show
#
header()
{
   echolog "[0;1m$1[0;0m"
}

fatal()
{
   echolog
   header "Fatal error occured - $1"
   echolog "Something went wrong and we can't continue. This should never happen."
   echolog "Please reboot your computer with Ctrl+Alt+Delete ..."
   echolog
   ash
}

allow_only_root()
{
  # test if the script is started by root user. If not, exit
  if [ "0$UID" -ne 0 ]; then
     echo "Only root can run `basename $0`"; exit 1
  fi
}

# ===========================================================
# text processing functions
# ===========================================================

# egrep_o is a replacement for "egrep -o". It prints only the last
# matching text
# $1 = regular expression
#
egrep_o()
{
   cat | egrep "$1" | sed -r "s/.*($1).*/\\1/"
}

# look into cmdline and echo $1 back if $1 is set
# $1 = value name, case sensitive, for example livecd_subdir
# $2 = file to use instead /proc/cmdline, optional
#
cmdline_parameter()
{
   CMDLINE=/proc/cmdline
   if [ "$2" != "" ]; then CMDLINE="$2"; fi
   cat "$CMDLINE" | egrep_o "(^|[[:space:]]+)$1(\$|=|[[:space:]]+)" | egrep_o "$1"
}

# look into cmdline and echo value of $1 option
# $1 = value name, case sensitive, for example livecd_subdir
# $2 = file to use instead /proc/cmdline, optional
#
cmdline_value()
{
   CMDLINE=/proc/cmdline
   if [ "$2" != "" ]; then CMDLINE="$2"; fi
   cat "$CMDLINE" | egrep_o "(^|[[:space:]]+)$1=([^[:space:]]+)" | egrep_o "=.*" | cut -b 2- | tail -n 1
}

# ===========================================================
# system functions
# ===========================================================

# modprobe module $1, including all dependencies, suppress all messages
# (own function because modprobe in busybox doesn't work with gzipped modules)
# $1 = module name, eg. ehci-hcd
# $2 = optional argument
#
modprobe_module()
{
  if [ "$1" = "" ]; then return 1; fi
  PRINTK=`cat /proc/sys/kernel/printk`
  echo "0" >/proc/sys/kernel/printk

  KERNEL="`uname -r`"; LSMOD=/tmp/_lsmod
  MODULEDEPS="`cat /lib/modules/$KERNEL/modules.dep | egrep \"$1\\.ko(\\.gz)?:\"`"

  for MODULE in `echo $MODULEDEPS | cut -d ":" -f 2-` `echo $MODULEDEPS | cut -d ":" -f 1`; do
     TMPMOD="/tmp/`basename $MODULE .gz`";
     # if the module is not loaded already
     if [ "`cat $LSMOD 2>/dev/null | egrep \"^$TMPMOD\\\$\"`" = "" ]; then
        gunzip -c $MODULE 2>/dev/null >$TMPMOD
        if [ "$?" -ne 0 ]; then cp $MODULE $TMPMOD; fi # can't gunzip? copy
        insmod $TMPMOD $2 >/dev/null 2>/dev/null; err=$?
        if [ "$err" -eq 0 ]; then echo $TMPMOD >>$LSMOD; fi # module log
        rm $TMPMOD
     fi
  done

  echo "$PRINTK" >/proc/sys/kernel/printk
  if [ "$err" -ne 0 ]; then echolog "error inserting module $1 ($err) for your kernel `uname -r`"; fi
  return $err
}

# Mount device $1 to $2
# $1 = /dev device to mount, eg. /dev/hda1
# $2 = mountpoint, eg. /mnt/hda1
# $3 = mount options, for example "loop", "ro", or "remount,rw"
# $4 = filesystem type
#
mount_device()
{
  mkdir -p $2
  if [ "$3" != "" ]; then OPTIONS="-o $3"; else OPTIONS=""; fi
  if [ "$4" != "" ]; then FILESYSTEM="-t $4"; else FILESYSTEM=""; fi

  PRINTK=`cat /proc/sys/kernel/printk`
  echo "0" >/proc/sys/kernel/printk

  mount $FILESYSTEM $1 $2 $OPTIONS >/dev/null 2>/dev/null
  err=$?

  if [ "$err" -ne 0 ]; then rmdir $2 2>/dev/null; fi
  echo "$PRINTK" >/proc/sys/kernel/printk
  return $err
}

# ===========================================================
# live module functions
# ===========================================================

# Create module
# call mksquashfs with apropriate arguments
# $1 = directory which will be compressed to squashfs module
# $2 = output .mo file
# $3 = optional -keep-as-directory argument
#
create_module()
{
   mksquashfs "$1" "$2" $3 >/dev/null
   if [ $? -ne 0 ]; then return 1; fi
   chmod oga-x "$2" # remove execute attrib
}

# Mount .mo module to destination directory
# $1 = path to .mo livecd compressed module
# $2 = destination folder
#
mount_module()
{
   mount -t squashfs -o loop,ro "$1" "$2"
   err=$?
   if [ $err -eq 0 ]; then
      echo "$1 $2" >>/tmp/_mounts
   fi
   return $err
}

# Insert a directory tree $2 to an union specified by $1
# Top-level read-write branch is specified by it's index 0
# $1 = union absolute path (starting with /)
# $2 = path to data directory
#
union_insert_dir()
{
   unionctl "$1" --add --after 0 --mode ro "$2"
}

# List all modules in all directories (base, modules, optional)
# and filter out unneeded optional modules (not specified by load= kernel parameter)
# $1 = root directory of mounted DATAdir
#
list_modules()
{
   LOAD="`cmdline_value load`"
   ls -A1d $1/base/*.mo $1/modules/*.mo $1/optional/*.mo 2>/dev/null | while read LINE; do
      MODNAME="`basename $LINE .mo`"
      if [ "$LOAD" != "*" -a "`echo $LINE | grep optional`" != "" -a "`echo $LOAD | egrep \"(^|,)$MODNAME(\\\$|,)\"`" = "" ]; then continue
        else echo $LINE; fi
   done
}

# Insert one single .mo module to the union
# $1 = union absolute path
# $2 = module.mo full path
# $3 = destination folder, where images will be mounted to
#
union_insert_module()
{
   TARGET="$3/`basename $2`"
   if mountpoint $TARGET >/dev/null 2>&1; then continue; fi # skip mounted modules
   mkdir -p $TARGET
   mount_module $2 $TARGET
   if [ $? -ne 0 ]; then echo "Cannot read module data. corrupted download?" >&2; return 1; fi
   union_insert_dir $1 $TARGET
   if [ $? -ne 0 ]; then echo "can't insert module to union" >&2; return 2; fi
   basename $TARGET
}

# Insert all .mo modules, in $2 directory and subdirectories, to the union
# $1 = union absolute path (starting with /)
# $2 = LiveCD data dir (with directories /base, /modules, etc.)
# $3 = destination folder, where images will be mounted to
#
union_insert_modules()
{
   list_modules $2 | while read MODULE; do
      echo -n " -> "
      union_insert_module $1 $MODULE $3
   done
}

# Copy LiveCD modules to RAM directory
# will copy only /boot, and module files from $1
# $1 = data directory
# $2 = target directory in RAM
#
copy_to_ram()
{
   cp -R "$1/boot" "$2" # kernel is not required but it's nice2have
   list_modules "$1" | while read MODULE; do
      TARGET="$2/`basename \`dirname $MODULE\``"
      mkdir -p "$TARGET"
      cp "$MODULE" "$TARGET"
      if [ "$?" -ne 0 ]; then fatal "can't copy to RAM, not enough memory?"; fi
   done
}

# Copy content of "rootcopy" directory on the CD to $2 (union, usually)
# $1 = source
# $2 = destination
#
copy_rootchanges()
{
   cp -a $1/rootcopy/* $2 2>/dev/null # could be empty
}

# ===========================================================
# discovery functions
# ===========================================================

# List all CD-ROMs
# by using /proc entries
#
list_cdrom_devices()
{
   if [ "`cmdline_parameter nocd`" != "" ]; then return 1; fi
   for CDDEVICE in `cat /proc/sys/dev/cdrom/info 2>/dev/null | head -n 3 | tail -n 1 | cut -d ":" -f 2`; do
      echo "/dev/$CDDEVICE"
   done
}

# List all devices with filesystems
# Return empty result when nohd parameter was given.
#
list_partition_devices()
{
   if [ "`cmdline_parameter nohd`" != "" ]; then return 1; fi
   cat /proc/partitions | grep -v loop | sed -r "s/^[0-9 ]+/\\/dev\\//" | grep /dev/
#   blkid | grep -v swap | cut -d : -f 1 | grep -v loop
}

# List all disk devices
#
list_disk_devices()
{
   list_partition_devices | egrep -v "[0-9]"
}

# List all partitions marked as Linux Swap
#
list_swap_devices()
{
   if [ "`cmdline_parameter nohd`" != "" ]; then return 1; fi
   blkid -t TYPE="swap" | cut -d : -f 1
}

# List all block devices
#
list_block_devices()
{
   list_cdrom_devices
   list_partition_devices
}

# Try to mount all disks, partitions and cdroms and Find where the LiveCD is.
# If LiveCD found in the device, echo dirname of it's directory,
# and leave the device mounted. Mounting is not ro, but without any argument.
# $1 = directory where devices will be mounted
#
find_live_data_dir()
{
   list_block_devices | while read DEVICE; do
      DIR="/$1/`basename $DEVICE`"
      mount_device $DEVICE $DIR
      if [ $? -ne 0 ]; then continue; fi
      FOUND=`ls -A1d $DIR/livecd.sgn $DIR/*/livecd.sgn 2>/dev/null | head -n 1`
      if [ "$FOUND" = "" ]; then umount $DIR 2>/dev/null; rmdir $DIR 2>/dev/null
      else dirname "$FOUND"; return 1; fi
   done
}

# ===========================================================
# hardware preparation functions
# ===========================================================

# Create block devices to /dev described by /sys entries
#
create_block_devices()
{
   echolog "creating /dev entries for block devices"
   ls -A1d /sys/block/*/dev /sys/block/*/*/dev 2>/dev/null | grep -v loop | while read BLOCK; do
      DEVICE="/dev/`basename \`dirname $BLOCK\``"
      if [ ! -b $DEVICE ]; then
         MINORMAJOR="`head -n 1 $BLOCK | tr ':' ' '`"
         mknod $DEVICE b $MINORMAJOR
      fi
   done
}

# modprobe kernel modules needed for the LiveCD
#
modprobe_essential_modules()
{
   echolog "starting loop device support"
   modprobe_module loop max_loop=255
   echolog "starting cdrom filesystem support"
   modprobe_module isofs
   echolog "starting squashfs support"
   modprobe_module squashfs
   echolog "starting unionfs support"
   modprobe_module unionfs
   echolog "starting vfat support"
   modprobe_module nls_cp437
   modprobe_module nls_iso8859-1
   modprobe_module nls_iso8859-2
   modprobe_module vfat
   echolog "starting ntfs support"
   modprobe_module ntfs
   create_block_devices
}

# modprobe kernel modules needed for USB masstorage devices
#
modprobe_usb_modules()
{
   echolog "starting USB support"
   modprobe_module ehci-hcd
   modprobe_module ohci-hcd
   modprobe_module uhci-hcd
   modprobe_module usb-storage
   sleep 5
   create_block_devices
}

# enable/disable CD autoejecting when unmounted
# $1 = 1|0 ... enable|disable
#
cd_autoeject()
{
   echo $1 >/proc/sys/dev/cdrom/autoeject
}

# Disable DMA if nodma boot parameter is present
#
setup_dma()
{
   if [ ! "`cmdline_parameter nodma`" = "" ]; then
      for DEVICE in `list_cdrom_devices` `list_disk_devices`; do
         echolog "setting DMA support off for $DEVICE"
         hdparm -d 0 $DEVICE
      done
   fi
}

# update given line in fstab, add new values only if the device is not found
# $1 = fstab file to parse
# $2 = device name
# $3 = mountpoint
# $4 = filesystem
# $5 = mount options
#
fstab_update_line()
{
   if [ "`cat \"$1\" | egrep \"^[[:space:]]*[^[:space:]]+[[:space:]]+$3\"`" = "" ]; then
      echo "$2" "$3" "$4" "$5" 0 0 "$FSTABLLFLAG" >>$1
   fi
}

# create correct fstab file in $1/etc/fstab and create apropriate
# mount directories in $1/mnt. Check for iocharset boot option,
# if present, add iocharset to all DOS/Win filesystems (vfat,ntfs)
# $1 = root directory (union)
#
fstab_update()
{
   IOCHARSET="`cmdline_value iocharset`"
   FSTAB="$1/etc/fstab"
   mkdir -p $1/etc $1/mnt
   cat $FSTAB 2>/dev/null | grep -v "$FSTABLLFLAG" >$FSTAB~

   fstab_update_line $FSTAB~ tmpfs / tmpfs defaults
   fstab_update_line $FSTAB~ devpts /dev/pts devpts gid=5,mode=620
   fstab_update_line $FSTAB~ proc /proc proc defaults

   list_cdrom_devices | while read DEVICE; do
      MOUNTDIR="/mnt/`basename $DEVICE`_cdrom"
      mkdir -p $1/$MOUNTDIR
      fstab_update_line $FSTAB~ $DEVICE $MOUNTDIR iso9660 noauto,users,exec
   done

   list_partition_devices | while read DEVICE; do
      unset REMOVABLE; unset OPT; DEV="`basename $DEVICE`"; DEV0="`echo $DEV | cut -b 1-3`"
      if [ "0`cat /sys/block/$DEV0/removable 2>/dev/null`" -ne 0 ]; then
         REMOVABLE="_removable"
      fi

      MOUNTDIR="/mnt/$DEV$REMOVABLE"
      FS="`blkid -s TYPE $DEVICE | cut -d = -f 2 | tr -d ' \"'`"

      # add special options for NTFS
      if [ "$FS" = "ntfs" ]; then
         OPT=",ro"
#         if [ "$IOCHARSET" != "" ]; then OPT="$OPT,nls=$IOCHARSET"; fi
         if [ "$IOCHARSET" != "" ]; then
            OPT="$OPT,nls=$IOCHARSET"
         else
            OPT="$OPT,nls=utf8"
         fi
      fi

      # add special options for VFAT
#      if [ "$FS" = "vfat" -a "$IOCHARSET" != ""  ]; then OPT=",iocharset=$IOCHARSET"; fi
      if [ "$FS" = "vfat" -a "$IOCHARSET" != ""  ]; then
         OPT=",iocharset=$IOCHARSET"
      else
         if [ "$FS" = "vfat" ]; then
            OPT=",iocharset=utf8,codepage=932"
         fi
      fi

      # if the partition has filesystem, add it to fstab
      if [ "$FS" != "" ]; then
         if [ "$FS" = "swap" ]; then
            fstab_update_line $FSTAB~ $DEVICE swap swap defaults
         else
            fstab_update_line $FSTAB~ $DEVICE $MOUNTDIR $FS auto,users,suid,dev,exec$OPT
            mkdir -p "$1/$MOUNTDIR"
         fi
      fi
   done

   fstab_update_line $FSTAB~ /dev/fd0 /mnt/floppy vfat,msdos noauto,users,suid,dev,exec
   mkdir -p $1/mnt/floppy
   
   mv -f $FSTAB~ $FSTAB
}
