mdisk

   1 #!/bin/sh
   2
   3 #==============================================================================
   4 # mdisk
   5 # File ID: 0548a2d2-ea04-11ed-b5e0-83850402c3ce
   6 #
   7 # Mount a LUKS-encrypted disk under /media/
   8 #
   9 # Author: Øyvind A. Holm <sunny@sunbase.org>
  10 # License: GNU General Public License version 2 or later.
  11 #==============================================================================
  12
  13 progname=mdisk
  14 VERSION=0.2.4
  15
  16 opt_help=0
  17 opt_quiet=0
  18 opt_umount=0
  19 opt_verbose=0
  20 while test -n "$1"; do
  21         case "$1" in
  22         -a|--all) opt_all=1; shift ;;
  23         -h|--help) opt_help=1; shift ;;
  24         -q|--quiet) opt_quiet=$(($opt_quiet + 1)); shift ;;
  25         -u|--umount) opt_umount=1; shift ;;
  26         -v|--verbose) opt_verbose=$(($opt_verbose + 1)); shift ;;
  27         --version) echo $progname $VERSION; exit 0 ;;
  28         --) shift; break ;;
  29         *)
  30                 if printf '%s\n' "$1" | grep -q ^-; then
  31                         echo "$progname: $1: Unknown option" >&2
  32                         exit 1
  33                 else
  34                         break
  35                 fi
  36         break ;;
  37         esac
  38 done
  39 opt_verbose=$(($opt_verbose - $opt_quiet))
  40
  41 [ -e "$HOME/.mdiskrc" ] && . "$HOME/.mdiskrc"
  42
  43 T_BOLD=$(tput bold)
  44 T_GREEN=$(tput setaf 2)
  45 T_RED=$(tput setaf 1)
  46 T_RESET=$(tput sgr0)
  47
  48 if test "$opt_help" = "1"; then
  49         test $opt_verbose -gt 0 && { echo; echo $progname $VERSION; }
  50         cat <<END
  51
  52 Mount a LUKS-encrypted disk under /media/.
  53
  54 Usage: $progname [options] DISKNAME
  55
  56 Options:
  57
  58   -a, --all
  59     Loop through all directory names under /media/ and mount or unmount
  60     all corresponding disks.
  61   -h, --help
  62     Show this help.
  63   -q, --quiet
  64     Be more quiet. Can be repeated to increase silence.
  65   -v, --verbose
  66     Increase level of verbosity. Can be repeated.
  67   -u, --umount
  68     Unmount the disk.
  69   --version
  70     Print version information.
  71
  72 Environment variables
  73
  74   MDISK_KEY_FILE
  75     Full path to text file with passphrase for encrypted drives.
  76
  77 Files and directories
  78
  79   \$HOME/.mdiskrc
  80     Init file. A regular shell script that can be used to initialize
  81     environment variables and run commands before normal program
  82     execution.
  83   .dontsleep/
  84     If this directory exists at the top of the disk, the disk is
  85     prevented from sleeping. When a disk with this directory is mounted,
  86     a background process is started that writes 512 random bytes to a
  87     file in this directory every two minutes. The current user must have
  88     write permission in this directory, otherwise sleeping is not
  89     prevented. When the disk is unmounted with -u/--umount, the process
  90     is killed.
  91
  92 END
  93         exit 0
  94 fi
  95
  96 msg() {
  97         test $1 -gt $opt_verbose && return;
  98         shift
  99         echo "$progname: $*" >&2
 100 }
 101
 102 err() {
 103         echo "$progname: $T_BOLD$T_RED$*$T_RESET" >&2
 104         exit 1
 105 }
 106
 107 is_active() {
 108         sudo cryptsetup status $disk | grep -q "/dev/mapper/$disk is active"
 109 }
 110
 111 is_in_blkid() {
 112         sudo blkid | grep -q "LABEL=\"$1\"" && return 0
 113         return 1
 114 }
 115
 116 is_mounted() {
 117         df | grep -q "/media/$disk\$" && return 0
 118         return 1
 119 }
 120
 121 strip_diskname() {
 122         echo $(echo "$1" | sed 's.^/media/..; s./$..')
 123 }
 124
 125 create_ds_script() {
 126         echo >$ds_script || err $ds_dir/: Cannot write to directory, \
 127                                 disk sleep is not prevented
 128         cat <<'END' >$ds_script
 129 #!/bin/sh
 130
 131 T_BOLD=$(tput bold)
 132 T_RED=$(tput setaf 1)
 133 T_RESET=$(tput sgr0)
 134 outfile=.dontsleep.bin
 135
 136 rm -f $outfile
 137 echo $$ >pid || {
 138         echo -n "$T_BOLD$T_RED$0: Cannot write pid file to $ds_dir," >&2
 139         echo " unable to prevent sleep$T_RESET" >&2
 140         exit 1
 141 }
 142 while :; do
 143         head -c 512 /dev/urandom >>$outfile
 144         (cd; sleep 120)
 145 done
 146 END
 147 }
 148
 149 prevent_sleep() {
 150         local disk=$1
 151
 152         msg 0 Preventing $disk from sleeping
 153         cd "$ds_dir" || err $ds_dir: chdir error
 154         (create_ds_script && sh $ds_script $disk) &
 155 }
 156
 157 kill_prevent() {
 158         local disk=$1
 159
 160         pidfile="$ds_dir/pid"
 161         if [ ! -f "$pidfile" ]; then
 162                 echo $progname: PID file $pidfile not found >&2
 163                 return
 164         fi
 165         kill $(cat $pidfile)
 166         rm $pidfile
 167 }
 168
 169 if [ "$opt_all" = "1" ]; then
 170         for f in /media/*; do
 171                 is_in_blkid $(strip_diskname $f) || continue
 172                 if [ "$opt_umount" = "1" ]; then
 173                         $0 -u $f
 174                 else
 175                         $0 $f
 176                 fi
 177         done
 178         exit
 179 fi
 180
 181 disk=$(strip_diskname $1)
 182 [ -z "$disk" ] && err No disk specified
 183
 184 is_in_blkid $disk || err $disk: Disk not found in blkid
 185
 186 ds_dir="/media/$disk/.dontsleep"
 187 ds_script=dontsleep
 188
 189 if [ "$opt_umount" != "1" ]; then
 190         is_mounted $disk && {
 191                 msg 0 $disk: Already mounted
 192                 exit 0
 193         }
 194         device=$(blkid -L $disk)
 195         msg 1 device = \"$device\"
 196         [ -z "$device" ] && err Cannot get device for $disk
 197         echo "$device" | grep -q ^/dev/ || err $device: Malformed device name
 198         is_active $disk \
 199         || sudo cryptsetup luksOpen \
 200         $([ -n "$MDISK_KEY_FILE" ] && echo "--key-file $MDISK_KEY_FILE") \
 201         $device $disk && mount /media/$disk
 202         is_mounted $disk \
 203         && msg 0 $T_BOLD$T_GREEN$disk mounted on /media/$disk$T_RESET \
 204         || err $disk: mount failed
 205         [ -d "$ds_dir" ] && prevent_sleep $disk
 206 else
 207         [ -d "$ds_dir" ] && kill_prevent $disk
 208         is_mounted $disk && umount /media/$disk
 209         [ -d "$ds_dir" ] && prevent_sleep $disk
 210         is_mounted $disk && err /media/$disk: umount failed
 211         sudo cryptsetup luksClose $disk
 212         sync
 213         is_active $disk && err $disk is still active
 214         msg 0 $T_BOLD$T_GREEN$disk is unmounted and closed$T_RESET
 215 fi
 216
 217 # vim: set ts=8 sw=8 sts=8 noet fo+=w tw=79 fenc=UTF-8 :