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=0.3.1
  15
  16 opt_help=0
  17 opt_interactive=0
  18 opt_quiet=0
  19 opt_umount=0
  20 opt_verbose=0
  21 while test -n "$1"; do
  22         case "$1" in
  23         -a|--all) opt_all=1; shift ;;
  24         -h|--help) opt_help=1; shift ;;
  25         -i|--interactive) opt_interactive=1; shift ;;
  26         -q|--quiet) opt_quiet=$(($opt_quiet + 1)); shift ;;
  27         -u|--umount) opt_umount=1; shift ;;
  28         -v|--verbose) opt_verbose=$(($opt_verbose + 1)); shift ;;
  29         --version) echo $progname $VERSION; exit 0 ;;
  30         --) shift; break ;;
  31         *)
  32                 if printf '%s\n' "$1" | grep -q ^-; then
  33                         echo "$progname: $1: Unknown option" >&2
  34                         exit 1
  35                 else
  36                         break
  37                 fi
  38         break ;;
  39         esac
  40 done
  41 opt_verbose=$(($opt_verbose - $opt_quiet))
  42
  43 [ -e "$HOME/.mdiskrc" ] && . "$HOME/.mdiskrc"
  44
  45 T_BOLD=$(tput bold)
  46 T_GREEN=$(tput setaf 2)
  47 T_RED=$(tput setaf 1)
  48 T_RESET=$(tput sgr0)
  49
  50 if test "$opt_help" = "1"; then
  51         test $opt_verbose -gt 0 && { echo; echo $progname $VERSION; }
  52         cat <<END
  53
  54 Mount a LUKS-encrypted disk under /media/.
  55
  56 Usage: $progname [options] DISKNAME
  57
  58 Options:
  59
  60   -a, --all
  61     Loop through all directory names under /media/ and mount or unmount
  62     all corresponding disks.
  63   -h, --help
  64     Show this help.
  65   -i, --interactive
  66     When used with -a/--all, ask for confirmation for each mountpoint.
  67   -q, --quiet
  68     Be more quiet. Can be repeated to increase silence.
  69   -v, --verbose
  70     Increase level of verbosity. Can be repeated.
  71   -u, --umount
  72     Unmount the disk.
  73   --version
  74     Print version information.
  75
  76 Environment variables
  77
  78   MDISK_KEY_FILE
  79     Full path to text file with passphrase for encrypted drives.
  80
  81 Files and directories
  82
  83   \$HOME/.mdiskrc
  84     Init file. A regular shell script that can be used to initialize
  85     environment variables and run commands before normal program
  86     execution.
  87   .dontsleep/
  88     If this directory exists at the top of the disk, the disk is
  89     prevented from sleeping. When a disk with this directory is mounted,
  90     a background process is started that touches a file in this
  91     directory every two minutes. The current user must have write
  92     permission in this directory, otherwise sleeping is not prevented.
  93     When the disk is unmounted with -u/--umount, the process is killed.
  94
  95 END
  96         exit 0
  97 fi
  98
  99 msg() {
 100         test $1 -gt $opt_verbose && return;
 101         shift
 102         echo "$progname: $*" >&2
 103 }
 104
 105 err() {
 106         echo "$progname: $T_BOLD$T_RED$*$T_RESET" >&2
 107         exit 1
 108 }
 109
 110 is_active() {
 111         sudo cryptsetup status $disk | grep -q "/dev/mapper/$disk is active"
 112 }
 113
 114 is_in_blkid() {
 115         sudo blkid | grep -q "LABEL=\"$1\"" && return 0
 116         return 1
 117 }
 118
 119 is_mounted() {
 120         df | grep -q "/media/$disk\$" && return 0
 121         return 1
 122 }
 123
 124 strip_diskname() {
 125         echo $(echo "$1" | sed 's.^/media/..; s./$..')
 126 }
 127
 128 create_ds_script() {
 129         echo >$ds_script || err $ds_dir/: Cannot write to directory, \
 130                                 disk sleep is not prevented
 131         cat <<'END' >$ds_script
 132 #!/bin/sh
 133
 134 T_BOLD=$(tput bold)
 135 T_RED=$(tput setaf 1)
 136 T_RESET=$(tput sgr0)
 137 outfile=.dontsleep.bin
 138
 139 rm -f $outfile
 140 echo $$ >pid || {
 141         echo -n "$T_BOLD$T_RED$0: Cannot write pid file to $ds_dir," >&2
 142         echo " unable to prevent sleep$T_RESET" >&2
 143         exit 1
 144 }
 145 while :; do
 146         touch $outfile
 147         (cd; sleep 120)
 148 done
 149 END
 150 }
 151
 152 prevent_sleep() {
 153         local disk=$1
 154
 155         msg 0 Preventing $disk from sleeping
 156         cd "$ds_dir" || err $ds_dir: chdir error
 157         (create_ds_script && sh $ds_script $disk) &
 158 }
 159
 160 kill_prevent() {
 161         local disk=$1
 162
 163         pidfile="$ds_dir/pid"
 164         if [ ! -f "$pidfile" ]; then
 165                 echo $progname: PID file $pidfile not found >&2
 166                 return
 167         fi
 168         kill $(cat $pidfile)
 169         rm $pidfile
 170 }
 171
 172 prompt() {
 173         [ "$opt_interactive" = "0" ] && return 0
 174         echo -n "$1 " >&2
 175         while :; do
 176                 echo -n "[y/n]: " >&2
 177                 read choice
 178                 [ "$choice" = "n" ] && return 1
 179                 [ "$choice" = "y" ] && return 0
 180         done
 181 }
 182
 183 if [ "$opt_all" = "1" ]; then
 184         for f in /media/*; do
 185                 is_in_blkid $(strip_diskname $f) || continue
 186                 if [ "$opt_umount" = "1" ]; then
 187                         prompt "Unmount $f?" && $0 -u $f
 188                 else
 189                         prompt "Mount $f?" && $0 $f
 190                 fi
 191         done
 192         exit
 193 fi
 194
 195 disk=$(strip_diskname $1)
 196 [ -z "$disk" ] && err No disk specified
 197
 198 is_in_blkid $disk || err $disk: Disk not found in blkid
 199
 200 ds_dir="/media/$disk/.dontsleep"
 201 ds_script=dontsleep
 202
 203 if [ "$opt_umount" != "1" ]; then
 204         is_mounted $disk && {
 205                 msg 0 $disk: Already mounted
 206                 exit 0
 207         }
 208         device=$(blkid -L $disk)
 209         msg 1 device = \"$device\"
 210         [ -z "$device" ] && err Cannot get device for $disk
 211         echo "$device" | grep -q ^/dev/ || err $device: Malformed device name
 212         is_active $disk \
 213         || sudo cryptsetup luksOpen \
 214         $([ -n "$MDISK_KEY_FILE" ] && echo "--key-file $MDISK_KEY_FILE") \
 215         $device $disk && mount /media/$disk
 216         is_mounted $disk \
 217         && msg 0 $T_BOLD$T_GREEN$disk mounted on /media/$disk$T_RESET \
 218         || err $disk: mount failed
 219         [ -d "$ds_dir" ] && prevent_sleep $disk
 220 else
 221         [ -d "$ds_dir" ] && kill_prevent $disk
 222         is_mounted $disk && umount /media/$disk
 223         [ -d "$ds_dir" ] && prevent_sleep $disk
 224         is_mounted $disk && err /media/$disk: umount failed
 225         sudo cryptsetup luksClose $disk
 226         sync
 227         is_active $disk && err $disk is still active
 228         msg 0 $T_BOLD$T_GREEN$disk is unmounted and closed$T_RESET
 229 fi
 230
 231 # vim: set ts=8 sw=8 sts=8 noet fo+=w tw=79 fenc=UTF-8 :