]> git.ipfire.org Git - ipfire-2.x.git/blobdiff - html/cgi-bin/extrahd.cgi
extrahd.cgi: Add is_configured function.
[ipfire-2.x.git] / html / cgi-bin / extrahd.cgi
index d46956e7db834f06140b36e7ae35f06e5febef5b..4db540aae423e5654485f37a8073c708377a6b8e 100644 (file)
@@ -2,7 +2,7 @@
 ###############################################################################
 #                                                                             #
 # IPFire.org - A linux based firewall                                         #
-# Copyright (C) 2007  Michael Tremer & Christian Schmidt                      #
+# Copyright (C) 2011  IPFire Team  <info@ipfire.org>                          #
 #                                                                             #
 # This program is free software: you can redistribute it and/or modify        #
 # it under the terms of the GNU General Public License as published by        #
@@ -29,27 +29,53 @@ require "${General::swroot}/lang.pl";
 require "${General::swroot}/header.pl";
 
 my %extrahdsettings = ();
-my $message = "";
 my $errormessage = "";
-my $size = "";
-my $ok = "true";
-my @tmp = ();
-my @tmpline = ();
-my $tmpentry = "";
-my @devices = ();
-my @deviceline = ();
-my $deviceentry = "";
-my @scans = ();
-my @scanline = ();
-my $scanentry = "";
-my @partitions = ();
-my @partitionline = ();
-my $partitionentry = "";
+
+# Hash to store the configured drives.
+my %configured_drives;
+
+# SYSFS directory which contains all block device data.
+my $sysfs_block_dir = "/sys/class/block";
+
+# Array which contains the valid mount directories.
+# Only mounting to subdirectories inside them is allowed.
+my @valid_mount_dirs = (
+       "/data",
+       "/media",
+       "/mnt",
+);
+
+# Array which contains the supported file systems.
+my @supported_filesystems = (
+       "auto",
+       "ext3",
+       "ext4",
+       "xfs",
+       "vfat",
+       "ntfs-3g"
+);
+
+# Grab all available block devices.
+my @devices = &get_block_devices();
+
+# Grab all known UUID's.
+my %uuids = &get_uuids();
+
+# Grab all mountpoints.
+my %mountpoints = &get_mountpoints();
+
+# Omit the file system types of the mounted devices.
+my %filesystems = &get_mountedfs();
+
+# Gather all used swap devices.
+my @swaps = &get_swaps();
+
+# The config file which contains the configured devices.
 my $devicefile = "/var/ipfire/extrahd/devices";
-my $scanfile = "/var/ipfire/extrahd/scan";
-my $partitionsfile = "/var/ipfire/extrahd/partitions";
-system("/usr/local/bin/scanhd ide");
-system("/usr/local/bin/scanhd partitions");
+
+#workaround to suppress a warning when a variable is used only once
+my @dummy = ( ${Header::colourgreen}, ${Header::colourred} );
+undef (@dummy);
 
 &Header::showhttpheaders();
 
@@ -58,8 +84,8 @@ $extrahdsettings{'PATH'} = '';
 $extrahdsettings{'FS'} = '';
 $extrahdsettings{'DEVICE'} = '';
 $extrahdsettings{'ACTION'} = '';
+$extrahdsettings{'UUID'} = '';
 
-&General::readhash("${General::swroot}/extrahd/settings", \%extrahdsettings);
 &Header::getcgihash(\%extrahdsettings);
 
 &Header::openpage('ExtraHD', 1, '');
@@ -68,51 +94,89 @@ $extrahdsettings{'ACTION'} = '';
 ############################################################################################################################
 ############################################################################################################################
 
-if ($extrahdsettings{'ACTION'} eq $Lang::tr{'add'})
-{
+#
+## Add a new device.
+#
+if ($extrahdsettings{'ACTION'} eq $Lang::tr{'add'}) {
+       # Open device file for reading.
        open( FILE, "< $devicefile" ) or die "Unable to read $devicefile";
-       @devices = <FILE>;
+       my @devices = <FILE>;
        close FILE;
-       foreach $deviceentry (sort @devices)
-       {
-               @deviceline = split( /\;/, $deviceentry );
-               if ( "$extrahdsettings{'PATH'}" eq "$deviceline[2]" ) {
-                       $ok = "false";
-                       $errormessage = "You can't mount $extrahdsettings{'DEVICE'} to $extrahdsettings{'PATH'}, because there is already a device mounted.";
+
+       # Loop through the entries line-by-line.
+       foreach my $entry (sort @devices) {
+               # Split the line into pieces and assign nice variables.
+               my ($uuid, $fs, $path) = split( /\;/, $entry );
+
+               # Check if the path is allready used.
+               if ( "$extrahdsettings{'PATH'}" eq "$path" ) {
+                       $errormessage = "$Lang::tr{'extrahd you cant mount'} $extrahdsettings{'DEVICE'} $Lang::tr{'extrahd to'} $extrahdsettings{'PATH'}$Lang::tr{'extrahd because there is already a device mounted'}.";
                }
-               if ( "$extrahdsettings{'PATH'}" eq "/" ) {
-                       $ok = "false";
-                       $errormessage = "You can't mount $extrahdsettings{'DEVICE'} to root /.";
+
+               # Check if the uuid is allready used.
+               if ("$extrahdsettings{'DEVICE'} eq $uuid") {
+                       $errormessage = "$extrahdsettings{'DEVICE'} is allready mounted.";
                }
        }
 
-       if ( "$ok" eq "true" ) {
+       # Check if a valid mount path has been choosen. 
+       unless(&is_valid_dir("$extrahdsettings{'PATH'}")) {
+               $errormessage = "$Lang::tr{'extrahd you cant mount'} $extrahdsettings{'DEVICE'} $Lang::tr{'extrahd to root'}.";
+       }
+
+       # Check if the given path allready is mounted somewhere.
+       if(&is_mounted("$extrahdsettings{'PATH'}")) {
+               $errormessage = "$Lang::tr{'extrahd you cant mount'} $extrahdsettings{'DEVICE'} $Lang::tr{'extrahd to'} $extrahdsettings{'PATH'}$Lang::tr{'extrahd because there is already a device mounted'}.";
+       }
+
+       # Check if there was an error message.
+       unless($errormessage) {
+               # Re-open the device file for writing.
                open(FILE, ">> $devicefile" ) or die "Unable to write $devicefile";
-               print FILE <<END
-$extrahdsettings{'DEVICE'};$extrahdsettings{'FS'};$extrahdsettings{'PATH'};
-END
-;
-       system("/usr/local/bin/extrahdctrl mount $extrahdsettings{'PATH'}");
+
+               # Write the config line.
+               print FILE "UUID=$extrahdsettings{'UUID'};$extrahdsettings{'FS'};$extrahdsettings{'PATH'};\n";
+
+               # Close file handle.
+               close(FILE);
+
+               # Call helper binary to mount the device.
+               &General::system("/usr/local/bin/extrahdctrl", "mount", "$extrahdsettings{'PATH'}");
        }
-} 
-elsif ($extrahdsettings{'ACTION'} eq $Lang::tr{'delete'}) 
-{
-       if ( `/usr/local/bin/extrahdctrl umount $extrahdsettings{'PATH'}` ) {
-               open( FILE, "< $devicefile" ) or die "Unable to read $devicefile";
-               @tmp = <FILE>;
-               close FILE;
-               open( FILE, "> $devicefile" ) or die "Unable to write $devicefile";
-               foreach $deviceentry (sort @tmp)
-               {
-                       @tmpline = split( /\;/, $deviceentry );
-                       if ( $tmpline[2] ne $extrahdsettings{'PATH'} )
-                       {
-                               print FILE $deviceentry;
+       
+#
+# Remove an existing one.
+#
+} elsif ($extrahdsettings{'ACTION'} eq $Lang::tr{'delete'})  {
+       # Call helper binary to unmount the device.
+       unless(&General::system("/usr/local/bin/extrahdctrl", "umount", "$extrahdsettings{'PATH'}")) {
+               # Open the device file for reading.
+               open(FILE, "< $devicefile" ) or die "Unable to read $devicefile";
+
+               # Read the file content into a temporary array.
+               my @tmp = <FILE>;
+
+               # Close file handle.
+               close(FILE);
+
+               # Re-open device file for writing.
+               open(FILE, "> $devicefile" ) or die "Unable to write $devicefile";
+
+               # Loop through the previous read file content.
+               foreach my $line (sort @tmp) {
+                       # Split line content and assign nice variables.
+                       my ($uuid, $fs, $path) = split( /\;/, $line );
+
+                       # Write the line in case it does not contain our element to delete.
+                       if ($path ne $extrahdsettings{'PATH'}) {
+                               print FILE "$line";
                        }
                }
-               close FILE;
+
+               # Close file handle.
+               close(FILE);
        } else {
-               $errormessage = "Can't umount $extrahdsettings{'PATH'}. Maybe the device is in use?";
+               $errormessage = "$Lang::tr{'extrahd cant umount'} $extrahdsettings{'PATH'}$Lang::tr{'extrahd maybe the device is in use'}?";
        }
 }
 
@@ -126,109 +190,139 @@ if ($errormessage) {
 ############################################################################################################################
 ############################################################################################################################
 
-&Header::openbox('100%', 'center', $Lang::tr{'extrahd'});
+&Header::openbox('100%', 'center', $Lang::tr{'extrahd detected drives'});
+
+       # Re-read mountpoints.
+       %mountpoints = &get_mountpoints();
+
+       # Read-in the device config file.
        open( FILE, "< $devicefile" ) or die "Unable to read $devicefile";
-       @devices = <FILE>;
-       close FILE;
-       print <<END
-               <table border='0' width='600' cellspacing="0">
-END
-;
-       foreach $deviceentry (sort @devices)
-       {
-               @deviceline = split( /\;/, $deviceentry );
-               my $color="$Header::colourred";
-               if ( `/bin/mount | /bin/fgrep $deviceline[2] | /bin/fgrep /dev/$deviceline[0]` ) {
-                       $color=$Header::colourgreen;
-               }
-               print <<END
-                       <tr><td colspan="5">&nbsp;
-                       <tr><td align='center'><font color=$color><b>/dev/$deviceline[0]</b></font>
-                               <td align='center'>$deviceline[1]
-                               <td align='center'>$deviceline[2]
-                               <td align='center'>
-                                       <form method='post' action='$ENV{'SCRIPT_NAME'}'>
-                                               <input type='hidden' name='DEVICE' value='$deviceline[0]' />
-                                               <input type='hidden' name='FS' value='$deviceline[1]' />
-                                               <input type='hidden' name='PATH' value='$deviceline[2]' />
-                                               <input type='hidden' name='ACTION' value=$Lang::tr{'delete'} />
-                                               <input type='image' alt=$Lang::tr{'delete'} src='/images/delete.gif' />
-                                       </form>
-END
-;
+
+       # Loop through the file content.
+       while (<FILE>) {
+               # Cut the line into pieces.
+               my ($uuid, $fs, $path) = split( /\;/, $_ );
+
+               # Add the found entry to the hash of configured drives.
+               $configured_drives{$uuid} = $path;
        }
-       print <<END
-               </table>
-END
-;
 
-&Header::closebox();
+       # Close the file handle.
+       close(FILE);
 
-&Header::openbox('100%', 'center', $Lang::tr{'extrahd founded drives'});
        print <<END
                <table border='0' width='600' cellspacing="0">
 END
 ;
-       open( FILE, "< $scanfile" ) or die "Unable to read $scanfile";
-       @scans = <FILE>;
-       close FILE;
-       open( FILE, "< $partitionsfile" ) or die "Unable to read $partitionsfile";
-       @partitions = <FILE>;
-       close FILE;
-       foreach $scanentry (sort @scans)
-       {
-               @scanline = split( /\;/, $scanentry );
+       foreach my $device (sort @devices) {
+               # Grab the device details.
+               my $vendor = &get_device_vendor($device);
+               my $model = &get_device_model($device);
+               my $bsize = &get_device_size($device);
+
+               # Convert size into human-readable format.
+               my $size = &General::formatBytes($bsize);
+
                print <<END
-                       <tr><td colspan="5">&nbsp;
-                       <tr><td align='center'><b>/dev/$scanline[0]</b>
-                               <td align='center' colspan="2">$scanline[1]
+                       <tr><td colspan="5">&nbsp;</td></tr>
+                       <tr><td align='left' colspan="2"><b>/dev/$device</b></td>
+                       <td align='center' colspan="2">$vendor $model</td>
+
+                       <td align='center'>$Lang::tr{'size'} $size</td>
+                       <td>&nbsp;</td></tr>
+                       <tr><td colspan="5">&nbsp;</td></tr>
 END
 ;
-               foreach $partitionentry (sort @partitions)
-               {
-                       @partitionline = split( /\;/, $partitionentry );
-                       if ( "$partitionline[0]" eq "$scanline[0]" ) {
-                               $size = int($partitionline[1] / 1024);
-                               print <<END
-                               <td align='center'>$Lang::tr{'size'} $size MB
-                               <td>&nbsp;
-                               <tr><td colspan="5">&nbsp;
+
+               # Grab the known partitions of the current block device.
+               my @partitions = &get_device_partitions($device);
+
+               foreach my $partition (@partitions) {
+                       my $disabled;
+
+                       # Omit the partition size.
+                       my $bsize = &get_device_size($partition);
+
+                       # Convert into human-readable format.
+                       my $size = &General::formatBytes($bsize);
+
+                       # Get the mountpoint.
+                       my $mountpoint = $mountpoints{$partition};
+
+                       # If no mountpoint could be determined try to grab from
+                       # configured drives.
+                       unless($mountpoint) {
+                               my $uuid = $uuids{$partition};
+
+                               # Build uuid string.
+                               $uuid = "UUID=" . $uuid;
+
+                               # Try to obtain a possible moutpoint from configured drives.
+                               $mountpoint = $configured_drives{$uuid} if ($configured_drives{$uuid});
+                       }
+
+                       # Check if the mountpoint is used as root or boot device.
+                       if ($mountpoint eq "/" or $mountpoint =~ "^/boot") {
+                               $disabled = "disabled";
+
+                       # Check if it is mounted.
+                       } elsif(&is_mounted($mountpoint)) {
+                               $disabled = "disabled";
+
+                       # Check if the device is used as swap.
+                       } elsif (&is_swap($partition)) {
+                               $disabled = "disabled";
+                               $mountpoint = "swap";
+                       }
+
+                       # Omit the used filesystem.
+                       my $fs = $filesystems{$partition};
+
+                       print <<END
+
+                       <form method='post' action='$ENV{'SCRIPT_NAME'}'>
+                       <tr><td align="left" colspan=5><strong>UUID=$uuids{$partition}</strong></td></tr>
+                       <tr>
+                       <td align="list">/dev/$partition</td>
+                               <td align="center">$Lang::tr{'size'} $size</td>
+                               <td align="center"><select name="FS" $disabled>
 END
 ;
-                       }
-               }
+                               # Loop through the array of supported filesystems.
+                               foreach my $filesystem (@supported_filesystems) {
+                                       my $selected;
 
-               foreach $partitionentry (sort @partitions)
-               {
-                       @partitionline = split( /\;/, $partitionentry );
-                       if (( "$partitionline[0]" =~ /^$scanline[0]/ ) && ! ( "$partitionline[0]" eq "$scanline[0]" )) {
-                               $size = int($partitionline[1] / 1024);
-                               print <<END
-                               <form method='post' action='$ENV{'SCRIPT_NAME'}'>
-                               <tr><td align="center">/dev/$partitionline[0]
-                               <td align="center">$Lang::tr{'size'} $size MB
-                               <td align='center'><select name="FS">
-                                                                               <option value="auto">auto</option>
-                                                                               <option value="ext3">ext3</option>
-                                                                               <option value="reiserfs">reiserfs</option>
-                                                                               <option value="vfat">fat</option>
-                                                                               <option value="ntfs-3g">ntfs (experimental)</option>
-                                                                          </select>
-                               <td align="center"><input type='text' name='PATH' value=/mnt/harddisk />
+                                       # Mark the used filesystem as selected.
+                                       if ($filesystem eq $fs) {
+                                               $selected = "selected";
+                                       }
+
+                                       print "<option value='$filesystem' $selected>$filesystem</option>\n";
+                               }
+
+                       print <<END
+                                       </select></td>
+                               <td align="center"><input type='text' name='PATH' value=$mountpoint $disabled></td>
                                <td align="center">
-                                       <input type='hidden' name='DEVICE' value='$partitionline[0]' />
-                                       <input type='hidden' name='ACTION' value=$Lang::tr{'add'} />
-                                       <input type='image' alt=$Lang::tr{'add'} src='/images/add.gif' />
-                               </form>
+                                       <input type='hidden' name='DEVICE' value='/dev/$partition' />
+                                       <input type='hidden' name='UUID' value='$uuids{$partition}' />
+                                       <input type='hidden' name='ACTION' value='$Lang::tr{'add'}' />
+END
+;                                      unless($disabled) {
+                                               print"<input type='image' alt='$Lang::tr{'add'}' title='$Lang::tr{'add'}' src='/images/add.gif' />\n";
+                                       }
 
+                               print <<END
+                               </form></td></tr>
 END
-;
-                       }
-               }
+;              }
+
        }
 
        print <<END
-       <tr><td align="center" colspan="5">If your device isn't listed here, you need to install or load the driver.<br />If you can see your device but no partitions you have to create them first.
+       <tr><td align="center" colspan="5">&nbsp;</td></tr>
+       <tr><td align="center" colspan="5">&nbsp;</td></tr>
+       <tr><td align="center" colspan="5">$Lang::tr{'extrahd install or load driver'}</td></tr>
        </table>
 END
 ;
@@ -236,3 +330,375 @@ END
 
 &Header::closebigbox();
 &Header::closepage();
+
+#
+## Function which return an array with all available block devices.
+#
+sub get_block_devices () {
+       my @devices;
+
+       # Open directory from kernel sysfs.
+       opendir(DEVICES, "/sys/block");
+
+       # Loop through the directory.
+       while(readdir(DEVICES)) {
+               # Skip . and ..
+               next if($_ =~ /^\.$/);
+               next if($_ =~ /^\..$/);
+
+               # Skip any loopback and ram devices.
+               next if($_ =~ "^loop");
+               next if($_ =~ "^ram");
+
+               # Add the device to the array of found devices.
+               push(@devices, $_);
+       }
+
+       # Close directory handle.
+       closedir(DEVICES);
+
+       # Return the devices array.
+       return @devices;
+}
+
+#
+## Function which return all partitions of a given block device.
+#
+sub get_device_partitions ($) {
+       my ($device) = @_;
+
+       # Array to store the known partitions for the given
+       # device.
+       my @partitions;
+
+       # Assign device directory.
+       my $device_dir = "$sysfs_block_dir/$device";
+
+       # Abort and return nothing if the device dir does not exist.
+       return unless(-d "$device_dir");
+
+       opendir(DEVICE, "$sysfs_block_dir/$device");
+       while(readdir(DEVICE)) {
+               next unless($_ =~ "^$device");
+
+               push(@partitions, $_);
+       }
+
+       closedir(DEVICE);
+
+       @partitions = sort(@partitions);
+
+       return @partitions;
+}
+
+#
+## Returns the vendor of a given block device.
+#
+sub get_device_vendor ($) {
+       my ($device) = @_;
+
+       # Assign device directory.
+       my $device_dir = "$sysfs_block_dir/$device";
+
+       # Abort and return nothing if the device dir does not exist
+       # or no vendor file exists.
+       return unless(-d "$device_dir");
+       return unless(-f "$device_dir/device/vendor");
+
+       # Open and read-in the device vendor.
+       open(VENDOR, "$device_dir/device/vendor");
+       my $vendor = <VENDOR>;
+       close(VENDOR);
+
+       # Abort and return nothing if no vendor could be read.
+       return unless($vendor);
+
+       # Remove any newlines from the vendor string.
+       chomp($vendor);
+
+       # Return the omited vendor.
+       return $vendor;
+}
+
+#
+## Returns the model name (string) of a given block device.
+#
+sub get_device_model ($) {
+       my ($device) = @_;
+
+       # Assign device directory.
+       my $device_dir = "$sysfs_block_dir/$device";
+
+       # Abort and return nothing if the device dir does not exist
+       # or no model file exists.
+       return unless(-d "$device_dir");
+       return unless(-f "$device_dir/device/model");
+
+       # Open and read-in the device model.
+       open(MODEL, "$device_dir/device/model");
+       my $model = <MODEL>;
+       close(MODEL);
+
+       # Abort and return nothing if no model could be read.
+       return unless($model);
+
+       # Remove any newlines from the model string.
+       chomp($model);
+
+       # Return the model string.
+       return $model;
+}
+
+#
+## Returns the size of a given device in bytes.
+#
+sub get_device_size ($) {
+       my ($device) = @_;
+
+       # Assign device directory.
+       my $device_dir = "$sysfs_block_dir/$device";
+
+       # Abort and return nothing if the device dir does not exist
+       # or no size file exists.
+       return unless(-d "$device_dir");
+       return unless(-f "$device_dir/size");
+
+       # Open and read-in the device size.
+       open(SIZE, "$device_dir/size");
+       my $size = <SIZE>;
+       close(SIZE);
+
+       # Abort and return nothing if the size could not be read.
+       return unless($size);
+
+       # Remove any newlines for the size string.
+       chomp($size);
+
+       # The omited size only contains the amount of blocks from the
+       # given device. To convert this into bytes we have to multiply this
+       # value with 512 bytes for each block. This is a static value used by
+       # the linux kernel.
+       $size = $size * 512;
+
+       # Return the size in bytes.
+       return $size;
+}
+
+#
+## Function which returns all currently mounted devices as a hash.
+## example: "sda1" -> "/boot"
+#
+sub get_mountpoints () {
+       my %mounts;
+
+       # Open and read-in the current mounts from the
+       # kernel file system.
+       open(MOUNT, "/proc/mounts");
+
+       # Loop through the known mounts.
+       while(<MOUNT>) {
+               # Skip mounts which does not belong to a device.
+               next unless ($_ =~ "^/dev");
+
+               # Cut the line into pieces and assign nice variables.
+               my ($dev, $mpoint, $fs, $options, $a, $b) = split(/ /, $_);
+
+               # Split the device name.
+               my @tmp = split("/", $dev);
+
+               # Assign the plain device name to a new variable.
+               # It is the last element of the array.
+               my $device = $tmp[-1];
+
+               # Add the mountpoint to the hash of mountpoints.
+               $mounts{"$device"} = $mpoint;
+       }
+
+       # Close file handle.
+       close(MOUNT);
+
+       # Return the hash of known mountpoints.
+       return %mounts;
+}
+
+sub get_swaps () {
+       my @swaps;
+
+       # Open and read the swaps file.
+       open(SWAP, "/proc/swaps");
+
+       # Loop though the file content.
+       while(<SWAP>) {
+               # Skip lines which does not belong to a device.
+               next unless ($_ =~ "^/dev");
+
+               # Split the line and assign nice variables.
+               my ($dev, $type, $size, $used, $prio) = split(/ /, $_);
+
+               # Cut the device line into pieces.
+               my @tmp = split("/", $dev);
+
+               my $device = @tmp[-1];
+
+               # Add the found swap to the array of swaps.
+               push(@swaps, $device);
+       }
+
+       # Close file handle.
+       close(SWAP);
+
+       # Sort the array.
+       @swaps = sort(@swaps);
+
+       # Return the array.
+       return @swaps;
+}
+
+#
+## Function with returns the mounted devices and the used filesystems as a hash.
+## Example: "sda1" -> "ext4"
+#
+sub get_mountedfs () {
+       my %mountedfs;
+
+       # Open and read the current mounts from the kernel
+       # file system.
+       open(MOUNT, "/proc/mounts");
+
+       # Loop through the known mounts.
+       while(<MOUNT>) {
+               # Skip mounts which does not belong to a device.
+               next unless ($_ =~ "^/dev");
+
+               # Split line and assign nice variables.
+               my ($dev, $mpoint, $fs, $options, $a, $b) = split(/ /, $_);
+
+               # Cut the device line into pieces.
+               my @tmp = split("/", $dev);
+
+               # Assign the plain device name to a variable
+               # It is the last element of the temporary array.
+               my $device = $tmp[-1];
+
+               # Convert the filesystem into lower case format.
+               $fs = lc($fs);
+
+               # Add the mounted file system.
+               $mountedfs{$device} = $fs;
+       }
+
+       # Close file handle.
+       close(MOUNT);
+
+       # Return the hash with the mounted filesystems.
+       return %mountedfs;
+}
+
+#
+## Function which returns all known UUID's as a hash.
+## Example: "sda1" -> "1234-5678-abcd"
+#
+sub get_uuids () {
+       my %uuids;
+
+       # Directory where the uuid mappings can be found.
+       my $uuid_dir = "/dev/disk/by-uuid";
+
+       # Open uuid directory and read-in the current known uuids.
+       opendir(UUIDS, "$uuid_dir");
+
+       # Loop through the uuids.
+       foreach my $uuid (readdir(UUIDS)) {
+               # Skip . and ..
+               next if($uuid eq "." or $uuid eq "..");
+
+               # Skip everything which is not a symbolic link.
+               next unless(-l "$uuid_dir/$uuid");
+
+               # Resolve the target of the symbolic link.
+               my $target = readlink("$uuid_dir/$uuid");
+
+               # Split the link target into pieces.
+               my @tmp = split("/", $target);
+
+               # Assign the last element of the array to the dev variable.
+               my $dev = "$tmp[-1]";
+
+               # Add the device and uuid to the hash of uuids.
+               $uuids{$dev} = $uuid;
+       }
+
+       # Close directory handle.
+       closedir(UUIDS);
+
+       # Return the hash of uuids.
+       return %uuids;
+}
+
+#
+## Returns the device name of a given uuid.
+#
+sub device_by_uuid ($) {
+       my ($uuid) = @_;
+
+       # Reverse the main uuids hash.
+       my %uuids = reverse %uuids;
+
+       # Lookup and return the device name.
+       return $uuids{$uuid};
+}
+
+#
+## Returns "True" in case a given path is a known mountpoint.
+#
+sub is_mounted ($) {
+       my ($mpoint) = @_;
+
+       my %mountpoints = reverse %mountpoints;
+
+       # Return "True" if the requested mountpoint is known and
+       # therefore mounted.
+       return 1 if($mountpoints{$mpoint});
+}
+
+#
+## Returns "True" if a given mountpoint is a subdirectory of one
+## of the directories specified by the valid_mount_dirs array abouve.
+#
+sub is_valid_dir ($) {
+       my ($mpoint) = @_;
+
+       # Split the given mountpoint into pieces and store them
+       # in a temporay array.
+       my @tmp = split("/", $mpoint);
+
+       # Exit and return nothing if the temporary array is empty.
+       return unless(@tmp);
+
+       # Build the root path based on the given mount point.
+       my $root_path = "/" . @tmp[1];
+
+       # Check if the root path is valid.
+       return 1 if(grep /$root_path/, @valid_mount_dirs);
+}
+
+#
+# Returns "True" if a device is used as swap.
+#
+sub is_swap ($) {
+       my ($device) = @_;
+
+       return 1 if(grep /$device/, @swaps);
+}
+
+#
+## Returns "True" if a drive is a configured one.
+#
+sub is_configured ($) {
+       my ($path) = @_;
+
+       # Loop through the hash of configured drives.
+       foreach my $uuid (keys %configured_drives) {
+              return 1 if($configured_drives{$uuid} eq "$path");
+       }
+}