#!/bin/sh
. common.sh

DEVNAME=$1
case "$DEVNAME" in /dev/loop*|/dev/ram*|/dev/dm-*|/dev/md*|/dev/fd*) exit ;; esac
[ -b "$DEVNAME" ] || exit

debug_log "grok-block.${DEVNAME##*/}"

addmenu_choosekey() 
{
  dev=$1
  dir=$2
  addmenu "$dev//$dir" \
	  "[ Use the GPG key on $dev ]" \
          "menu-select boot-gpg $dev $dir"
}

addmenu_repairhfs()
{
  local device="$1"
  addmenu "$device//reboot" \
    "[ Reboot into Mac OS X in order to repair disk $device ]" \
    "eject /cdrom; sleep 2; reboot -f"
  addmenu "$device//fsck" \
    "[ (DANGEROUS) Try to repair errors on $device with fsck.hfsplus ]" \
    "/bin/openvt -sw -- sh -c 'fsck.hfsplus $device && remenu'"
}

addmenu_chooseroot()
{
  local device="$1" loopfile="$2"

  addmenu "$device//$loopfile" \
    "[ Boot the system on $device${loopfile:+ in file $(basename $loopfile)} ]" \
    "menu-select --fs=$ID_FS_TYPE boot-luks $device ${loopfile:-$device}"
}

addmenu_makeroot()
{
  local device="$1" loopfile="$2" megs="$3" copy_cdrom="$4"
  (
    addmenu "$device//$loopfile" \
      "[ Install Samizdat to $device (in file $(basename $loopfile)) ]" \
      "menu-select --fs=$ID_FS_TYPE boot-new $device $loopfile $megs $copy_cdrom"
  ) &
}

retry_mount()
{
  tries=20
  until mntout="$(mount "$@" 2>&1)"
  do
    tries=$(( tries - 1 ))
    case "$mntout" in 
      *"Device or resource busy"*) 
        if [ $tries -le 0 ]; then
          warn "mount $@ failed: $mntout"
          return 1
        else
          sleep 1
          continue
        fi
        ;;
      *)
        warn "mount $@ failed: $mntout"
        break ;;
    esac
  done
}

gpg_verify()
{
  bootwait samizdat-gpg
  export GNUPGHOME=/gpg/gnupghome
  gpg2 --lock-never --no-permission-warning --no-auto-check-trustdb --no-options --verify "$1"
}
is_lvm()
{
  for n in 0 1 2 3; do
    [ "LVM2 001" = "$(dd if="$1" bs=1 skip=$((512*n+24)) count=8 2>/dev/null)" ] && return 0
  done
  return 1
}

grok_block()
{
  local mountpoint="/mnt/${DEVNAME##*/}"

  mkdir -p "$mountpoint"

  case "$ID_FS_TYPE" in
    ntfs) mount_type='-t ntfs-3g' ;;
    "")   mount_type= ;;
    *)    mount_type="-t $ID_FS_TYPE" ;;
  esac

  if [ "$ID_FS_TYPE" = hfsplus ] && ! fsck.hfsplus -q "$DEVNAME"; then
    (if fsck.hfsplus "$DEVNAME"; then
      grok-block "$DEVNAME"
    else
      addmenu_repairhfs "$DEVNAME"
    fi) &
    return
  fi

  if ! mountpoint -q "$mountpoint"; then
    retry_mount $mount_type -o ro "$DEVNAME" "$mountpoint"
  fi

  if mountpoint -q "$mountpoint"; then
    umount=true
    # Device has an unencrypted filesystem on it.
    # So we mount it and look for loop-back overlays.

    if [ -d "$mountpoint/samizdat.gpg" ]; then
      # check the key somehow?
      addmenu_choosekey "$DEVNAME" "$mountpoint/samizdat.gpg"
    fi

    N=1; while [ -e "$mountpoint/samizdat.$N" ]
    do
      if gpg_verify "$mountpoint/samizdat.$N"k; then
        addmenu_chooseroot "$DEVNAME" "$mountpoint/samizdat.$N"
        # this menu entry chooses the root fs, and should prompt and wait for the matching key
        umount=false
      fi
      N=$((N+1))
    done

    freeblocks=$(stat -f -c %f "$mountpoint")
    blocksize=$(stat -f -c %S "$mountpoint")
    freemegs=$((freeblocks * blocksize / 1024 / 1024))

    if [ "$freemegs" -ge 300 ]; then

      umount=false
      bootwait samizdat-cdrom
      cdromblocks=$(stat -f -c %b /cdrom)
      cdromblocksize=$(stat -f -c %S /cdrom)
      cdrommegs=$((cdromblocks * cdromblocksize / 1024 / 1024))

      if [ "$freemegs"   -ge "$((cdrommegs * 3))" ]; then
        addmenu_makeroot "$DEVNAME" "${mountpoint}/samizdat.$N" "$((cdrommegs * 3))" 1
      elif [ "$freemegs" -ge "$((cdrommegs * 2))" ]; then
        addmenu_makeroot "$DEVNAME" "${mountpoint}/samizdat.$N" "$((cdrommegs * 2))" 1
      elif [ "$freemegs" -ge "$cdrommegs" ]; then
        addmenu_makeroot "$DEVNAME" "${mountpoint}/samizdat.$N" "$((freemegs / 2))" 0
      else
        addmenu_makeroot "$DEVNAME" "${mountpoint}/samizdat.$N" 256 0
      fi
    fi

    if $umount; then
      umount "$mountpoint"
      rmdir "$mountpoint"
    fi
  else
    rmdir "$mountpoint"
  fi
}

# Get me all them nice udev variables
eval "$(PATH=$PATH:/lib/udev vol_id "$DEVNAME" | 
  sed "s/'/'\\\\''/; s/=\(.*\)/='\1'/"
)"

CDROM_ID_FS_UUID_ENC='73256269-4002-4e42-adbd-0e49ed1c7438'
CDROM_ID_FS_LABEL_ENC=$(sed 's/ /\\x20/g' /lib/samizdat/vol_id.txt)
if [ "$ID_FS_UUID_ENC"  = "$CDROM_ID_FS_UUID_ENC" -o \
     "$ID_FS_LABEL_ENC" = "$CDROM_ID_FS_LABEL_ENC" ]
then
  # Recognize and mount the Samizdat 
  if ! mountpoint -q /cdrom; then
    mkdir -p /cdrom
    . mdadm-dup.sh
    dup_mount_cdrom "$DEVNAME" /cdrom && bootdone samizdat-cdrom
  fi
else
  grok_block &
fi

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