html/cgi-bin/ids.cgi

   1 #!/usr/bin/perl
   2 ###############################################################################
   3 #                                                                             #
   4 # IPFire.org - A linux based firewall                                         #
   5 # Copyright (C) 2007-2018  IPFire Team  <info@ipfire.org>                     #
   6 #                                                                             #
   7 # This program is free software: you can redistribute it and/or modify        #
   8 # it under the terms of the GNU General Public License as published by        #
   9 # the Free Software Foundation, either version 3 of the License, or           #
  10 # (at your option) any later version.                                         #
  11 #                                                                             #
  12 # This program is distributed in the hope that it will be useful,             #
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of              #
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
  15 # GNU General Public License for more details.                                #
  16 #                                                                             #
  17 # You should have received a copy of the GNU General Public License           #
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
  19 #                                                                             #
  20 ###############################################################################
  21
  22 use strict;
  23
  24 # enable only the following on debugging purpose
  25 #use warnings;
  26 #use CGI::Carp 'fatalsToBrowser';
  27
  28 require '/var/ipfire/general-functions.pl';
  29 require "${General::swroot}/lang.pl";
  30 require "${General::swroot}/header.pl";
  31 require "${General::swroot}/ids-functions.pl";
  32
  33 my %color = ();
  34 my %mainsettings = ();
  35 my %idsrules = ();
  36 my %idssettings=();
  37 my %rulessettings=();
  38 my %rulesetsources = ();
  39 my %cgiparams=();
  40 my %checked=();
  41 my %selected=();
  42 my %ignored=();
  43
  44 # Read-in main settings, for language, theme and colors.
  45 &General::readhash("${General::swroot}/main/settings", \%mainsettings);
  46 &General::readhash("/srv/web/ipfire/html/themes/".$mainsettings{'THEME'}."/include/colors.txt", \%color);
  47
  48 # Get the available network zones, based on the config type of the system and store
  49 # the list of zones in an array.
  50 my @network_zones = &IDS::get_available_network_zones();
  51
  52 my $errormessage;
  53
  54 # Create files if they does not exist yet.
  55 &IDS::check_and_create_filelayout();
  56
  57 # Hash which contains the colour code of a network zone.
  58 my %colourhash = (
  59         'red' => $Header::colourred,
  60         'green' => $Header::colourgreen,
  61         'blue' => $Header::colourblue,
  62         'orange' => $Header::colourorange
  63 );
  64
  65 &Header::showhttpheaders();
  66
  67 #Get GUI values
  68 &Header::getcgihash(\%cgiparams);
  69
  70 ## Add/edit an entry to the ignore file.
  71 #
  72 if (($cgiparams{'WHITELIST'} eq $Lang::tr{'add'}) || ($cgiparams{'WHITELIST'} eq $Lang::tr{'update'})) {
  73
  74         # Check if any input has been performed.
  75         if ($cgiparams{'IGNORE_ENTRY_ADDRESS'} ne '') {
  76
  77                 # Check if the given input is no valid IP-address or IP-address with subnet, display an error message.
  78                 if ((!&General::validip($cgiparams{'IGNORE_ENTRY_ADDRESS'})) && (!&General::validipandmask($cgiparams{'IGNORE_ENTRY_ADDRESS'}))) {
  79                         $errormessage = "$Lang::tr{'guardian invalid address or subnet'}";
  80                 }
  81         } else {
  82                 $errormessage = "$Lang::tr{'guardian empty input'}";
  83         }
  84
  85         # Go further if there was no error.
  86         if ($errormessage eq '') {
  87                 my %ignored = ();
  88                 my $id;
  89                 my $status;
  90
  91                 # Assign hash values.
  92                 my $new_entry_address = $cgiparams{'IGNORE_ENTRY_ADDRESS'};
  93                 my $new_entry_remark = $cgiparams{'IGNORE_ENTRY_REMARK'};
  94
  95                 # Read-in ignoredfile.
  96                 &General::readhasharray($IDS::ignored_file, \%ignored);
  97
  98                 # Check if we should edit an existing entry and got an ID.
  99                 if (($cgiparams{'WHITELIST'} eq $Lang::tr{'update'}) && ($cgiparams{'ID'})) {
 100                         # Assin the provided id.
 101                         $id = $cgiparams{'ID'};
 102
 103                         # Undef the given ID.
 104                         undef($cgiparams{'ID'});
 105
 106                         # Grab the configured status of the corresponding entry.
 107                         $status = $ignored{$id}[2];
 108                 } else {
 109                         # Each newly added entry automatically should be enabled.
 110                         $status = "enabled";
 111
 112                         # Generate the ID for the new entry.
 113                         #
 114                         # Sort the keys by their ID and store them in an array.
 115                         my @keys = sort { $a <=> $b } keys %ignored;
 116
 117                         # Reverse the key array.
 118                         my @reversed = reverse(@keys);
 119
 120                         # Obtain the last used id.
 121                         my $last_id = @reversed[0];
 122
 123                         # Increase the last id by one and use it as id for the new entry.
 124                         $id = ++$last_id;
 125                 }
 126
 127                 # Add/Modify the entry to/in the ignored hash.
 128                 $ignored{$id} = ["$new_entry_address", "$new_entry_remark", "$status"];
 129
 130                 # Write the changed ignored hash to the ignored file.
 131                 &General::writehasharray($IDS::ignored_file, \%ignored);
 132
 133                 # Regenerate the ignore file.
 134                 &IDS::generate_ignore_file();
 135         }
 136
 137         # Check if the IDS is running.
 138         if(&IDS::ids_is_running()) {
 139                 # Call suricatactrl to perform a reload.
 140                 &IDS::call_suricatactrl("reload");
 141         }
 142
 143 ## Toggle Enabled/Disabled for an existing entry on the ignore list.
 144 #
 145
 146 } elsif ($cgiparams{'WHITELIST'} eq $Lang::tr{'toggle enable disable'}) {
 147         my %ignored = ();
 148
 149         # Only go further, if an ID has been passed.
 150         if ($cgiparams{'ID'}) {
 151                 # Assign the given ID.
 152                 my $id = $cgiparams{'ID'};
 153
 154                 # Undef the given ID.
 155                 undef($cgiparams{'ID'});
 156
 157                 # Read-in ignoredfile.
 158                 &General::readhasharray($IDS::ignored_file, \%ignored);
 159
 160                 # Grab the configured status of the corresponding entry.
 161                 my $status = $ignored{$id}[2];
 162
 163                 # Switch the status.
 164                 if ($status eq "disabled") {
 165                         $status = "enabled";
 166                 } else {
 167                         $status = "disabled";
 168                 }
 169
 170                 # Modify the status of the existing entry.
 171                 $ignored{$id} = ["$ignored{$id}[0]", "$ignored{$id}[1]", "$status"];
 172
 173                 # Write the changed ignored hash to the ignored file.
 174                 &General::writehasharray($IDS::ignored_file, \%ignored);
 175
 176                 # Regenerate the ignore file.
 177                 &IDS::generate_ignore_file();
 178
 179                 # Check if the IDS is running.
 180                 if(&IDS::ids_is_running()) {
 181                         # Call suricatactrl to perform a reload.
 182                         &IDS::call_suricatactrl("reload");
 183                 }
 184         }
 185
 186 ## Remove entry from ignore list.
 187 #
 188 } elsif ($cgiparams{'WHITELIST'} eq $Lang::tr{'remove'}) {
 189         my %ignored = ();
 190
 191         # Read-in ignoredfile.
 192         &General::readhasharray($IDS::ignored_file, \%ignored);
 193
 194         # Drop entry from the hash.
 195         delete($ignored{$cgiparams{'ID'}});
 196
 197         # Undef the given ID.
 198         undef($cgiparams{'ID'});
 199
 200         # Write the changed ignored hash to the ignored file.
 201         &General::writehasharray($IDS::ignored_file, \%ignored);
 202
 203         # Regenerate the ignore file.
 204         &IDS::generate_ignore_file();
 205
 206         # Check if the IDS is running.
 207         if(&IDS::ids_is_running()) {
 208                 # Call suricatactrl to perform a reload.
 209                 &IDS::call_suricatactrl("reload");
 210         }
 211 }
 212
 213 # Check if any error has been stored.
 214 if (-e $IDS::storederrorfile) {
 215         # Open file to read in the stored error message.
 216         open(FILE, "<$IDS::storederrorfile") or die "Could not open $IDS::storederrorfile. $!\n";
 217
 218         # Read the stored error message.
 219         $errormessage = <FILE>;
 220
 221         # Close file.
 222         close (FILE);
 223
 224         # Delete the file, which is now not longer required.
 225         unlink($IDS::storederrorfile);
 226 }
 227
 228 ## Grab all available snort rules and store them in the idsrules hash.
 229 #
 230 # Open snort rules directory and do a directory listing.
 231 opendir(DIR, $IDS::rulespath) or die $!;
 232         # Loop through the direcory.
 233         while (my $file = readdir(DIR)) {
 234
 235                 # We only want files.
 236                 next unless (-f "$IDS::rulespath/$file");
 237
 238                 # Ignore empty files.
 239                 next if (-z "$IDS::rulespath/$file");
 240
 241                 # Use a regular expression to find files ending in .rules
 242                 next unless ($file =~ m/\.rules$/);
 243
 244                 # Ignore files which are not read-able.
 245                 next unless (-R "$IDS::rulespath/$file");
 246
 247                 # Skip whitelist rules file.
 248                 next if( $file eq "whitelist.rules");
 249
 250                 # Call subfunction to read-in rulefile and add rules to
 251                 # the idsrules hash.
 252                 &readrulesfile("$file");
 253         }
 254
 255 closedir(DIR);
 256
 257 # Gather used rulefiles.
 258 #
 259 # Check if the file for activated rulefiles is not empty.
 260 if(-f $IDS::used_rulefiles_file) {
 261         # Open the file for used rulefile and read-in content.
 262         open(FILE, $IDS::used_rulefiles_file) or die "Could not open $IDS::used_rulefiles_file. $!\n";
 263
 264         # Read-in content.
 265         my @lines = <FILE>;
 266
 267         # Close file.
 268         close(FILE);
 269
 270         # Loop through the array.
 271         foreach my $line (@lines) {
 272                 # Remove newlines.
 273                 chomp($line);
 274
 275                 # Skip comments.
 276                 next if ($line =~ /\#/);
 277
 278                 # Skip blank  lines.
 279                 next if ($line =~ /^\s*$/);
 280
 281                 # Gather rule sid and message from the ruleline.
 282                 if ($line =~ /.*- (.*)/) {
 283                         my $rulefile = $1;
 284
 285                         # Check if the current rulefile exists in the %idsrules hash.
 286                         # If not, the file probably does not exist anymore or contains
 287                         # no rules.
 288                         if($idsrules{$rulefile}) {
 289                                 # Add the rulefile state to the %idsrules hash.
 290                                 $idsrules{$rulefile}{'Rulefile'}{'State'} = "on";
 291                         }
 292                 }
 293         }
 294 }
 295
 296 # Save ruleset configuration.
 297 if ($cgiparams{'RULESET'} eq $Lang::tr{'save'}) {
 298         my %oldsettings;
 299         my %rulesetsources;
 300
 301         # Read-in current (old) IDS settings.
 302         &General::readhash("$IDS::rules_settings_file", \%oldsettings);
 303
 304         # Get all available ruleset locations.
 305         &General::readhash("$IDS::rulesetsourcesfile", \%rulesetsources);
 306
 307         # Prevent form name from been stored in conf file.
 308         delete $cgiparams{'RULESET'};
 309
 310         # Grab the URL based on the choosen vendor.
 311         my $url = $rulesetsources{$cgiparams{'RULES'}};
 312
 313         # Check if the choosen vendor (URL) requires an subscription/oinkcode.
 314         if ($url =~ /\<oinkcode\>/ ) {
 315                 # Check if an subscription/oinkcode has been provided.
 316                 if ($cgiparams{'OINKCODE'}) {
 317                         # Check if the oinkcode contains unallowed chars.
 318                         unless ($cgiparams{'OINKCODE'} =~ /^[a-z0-9]+$/) {
 319                                 $errormessage = $Lang::tr{'invalid input for oink code'};
 320                         }
 321                 } else {
 322                         # Print an error message, that an subsription/oinkcode is required for this
 323                         # vendor.
 324                         $errormessage = $Lang::tr{'ids oinkcode required'};
 325                 }
 326         }
 327
 328         # Go on if there are no error messages.
 329         if (!$errormessage) {
 330                 # Store settings into settings file.
 331                 &General::writehash("$IDS::rules_settings_file", \%cgiparams);
 332
 333                 # Check if the the automatic rule update hass been touched.
 334                 if($cgiparams{'AUTOUPDATE_INTERVAL'} ne $oldsettings{'AUTOUPDATE_INTERVAL'}) {
 335                         # Call suricatactrl to set the new interval.
 336                         &IDS::call_suricatactrl("cron", $cgiparams{'AUTOUPDATE_INTERVAL'});
 337                 }
 338
 339                 # Check if a ruleset is present - if not or the source has been changed download it.
 340                 if((! %idsrules) || ($oldsettings{'RULES'} ne $cgiparams{'RULES'})) {
 341                         # Check if the red device is active.
 342                         unless (-e "${General::swroot}/red/active") {
 343                                 $errormessage = "$Lang::tr{'could not download latest updates'} - $Lang::tr{'system is offline'}";
 344                         }
 345
 346                         # Check if enought free disk space is availabe.
 347                         if(&IDS::checkdiskspace()) {
 348                                 $errormessage = "$Lang::tr{'not enough disk space'}";
 349                         }
 350
 351                         # Check if any errors happend.
 352                         unless ($errormessage) {
 353                                 # Lock the webpage and print notice about downloading
 354                                 # a new ruleset.
 355                                 &working_notice("$Lang::tr{'snort working'}");
 356
 357                                 # Call subfunction to download the ruleset.
 358                                 if(&IDS::downloadruleset()) {
 359                                         $errormessage = $Lang::tr{'could not download latest updates'};
 360
 361                                         # Call function to store the errormessage.
 362                                         &IDS::_store_error_message($errormessage);
 363                                 } else {
 364                                         # Call subfunction to launch oinkmaster.
 365                                         &IDS::oinkmaster();
 366                                 }
 367
 368                                 # Check if the IDS is running.
 369                                 if(&IDS::ids_is_running()) {
 370                                         # Call suricatactrl to stop the IDS - because of the changed
 371                                         # ruleset - the use has to configure it before suricata can be
 372                                         # used again.
 373                                         &IDS::call_suricatactrl("stop");
 374                                 }
 375
 376                                 # Perform a reload of the page.
 377                                 &reload();
 378                         }
 379                 }
 380         }
 381
 382 # Save ruleset.
 383 } elsif ($cgiparams{'RULESET'} eq $Lang::tr{'update'}) {
 384         # Arrays to store which rulefiles have been enabled and will be used.
 385         my @enabled_rulefiles;
 386
 387         # Hash to store the user-enabled and disabled sids.
 388         my %enabled_disabled_sids;
 389
 390         # Loop through the hash of idsrules.
 391         foreach my $rulefile(keys %idsrules) {
 392                 # Check if the rulefile is enabled.
 393                 if ($cgiparams{$rulefile} eq "on") {
 394                         # Add rulefile to the array of enabled rulefiles.
 395                         push(@enabled_rulefiles, $rulefile);
 396
 397                         # Drop item from cgiparams hash.
 398                         delete $cgiparams{$rulefile};
 399                 }
 400         }
 401
 402         # Read-in the files for enabled/disabled sids.
 403         # This will be done by calling the read_enabled_disabled_sids_file function two times
 404         # and merge the returned hashes together into the enabled_disabled_sids hash.
 405         %enabled_disabled_sids = (
 406                 &read_enabled_disabled_sids_file($IDS::disabled_sids_file),
 407                 &read_enabled_disabled_sids_file($IDS::enabled_sids_file));
 408
 409         # Loop through the hash of idsrules.
 410         foreach my $rulefile (keys %idsrules) {
 411                 # Loop through the single rules of the rulefile.
 412                 foreach my $sid (keys %{$idsrules{$rulefile}}) {
 413                         # Skip the current sid if it is not numeric.
 414                         next unless ($sid =~ /\d+/ );
 415
 416                         # Check if there exists a key in the cgiparams hash for this sid.
 417                         if (exists($cgiparams{$sid})) {
 418                                 # Look if the rule is disabled.
 419                                 if ($idsrules{$rulefile}{$sid}{'State'} eq "off") {
 420                                         # Check if the state has been set to 'on'.
 421                                         if ($cgiparams{$sid} eq "on") {
 422                                                 # Add/Modify the sid to/in the enabled_disabled_sids hash.
 423                                                 $enabled_disabled_sids{$sid} = "enabled";
 424
 425                                                 # Drop item from cgiparams hash.
 426                                                 delete $cgiparams{$rulefile}{$sid};
 427                                         }
 428                                 }
 429                         } else {
 430                                 # Look if the rule is enabled.
 431                                 if ($idsrules{$rulefile}{$sid}{'State'} eq "on") {
 432                                         # Check if the state is 'on' and should be disabled.
 433                                         # In this case there is no entry
 434                                         # for the sid in the cgiparams hash.
 435                                         # Add/Modify it to/in the enabled_disabled_sids hash.
 436                                         $enabled_disabled_sids{$sid} = "disabled";
 437
 438                                         # Drop item from cgiparams hash.
 439                                         delete $cgiparams{$rulefile}{$sid};
 440                                 }
 441                         }
 442                 }
 443         }
 444
 445         # Open enabled sid's file for writing.
 446         open(ENABLED_FILE, ">$IDS::enabled_sids_file") or die "Could not write to $IDS::enabled_sids_file. $!\n";
 447
 448         # Open disabled sid's file for writing.
 449         open(DISABLED_FILE, ">$IDS::disabled_sids_file") or die "Could not write to $IDS::disabled_sids_file. $!\n";
 450
 451         # Write header to the files.
 452         print ENABLED_FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
 453         print DISABLED_FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
 454
 455         # Check if the hash for enabled/disabled files contains any entries.
 456         if (%enabled_disabled_sids) {
 457                 # Loop through the hash.
 458                 foreach my $sid (keys %enabled_disabled_sids) {
 459                         # Check if the sid is enabled.
 460                         if ($enabled_disabled_sids{$sid} eq "enabled") {
 461                                 # Print the sid to the enabled_sids file.
 462                                 print ENABLED_FILE "enablesid $sid\n";
 463                         # Check if the sid is disabled.
 464                         } elsif ($enabled_disabled_sids{$sid} eq "disabled") {
 465                                 # Print the sid to the disabled_sids file.
 466                                 print DISABLED_FILE "disablesid $sid\n";
 467                         # Something strange happende - skip the current sid.
 468                         } else {
 469                                 next;
 470                         }
 471                 }
 472         }
 473
 474         # Close file for enabled_sids after writing.
 475         close(ENABLED_FILE);
 476
 477         # Close file for disabled_sids after writing.
 478         close(DISABLED_FILE);
 479
 480         # Call function to generate and write the used rulefiles file.
 481         &IDS::write_used_rulefiles_file(@enabled_rulefiles);
 482
 483         # Lock the webpage and print message.
 484         &working_notice("$Lang::tr{'snort working'}");
 485
 486         # Call oinkmaster to alter the ruleset.
 487         &IDS::oinkmaster();
 488
 489         # Check if the IDS is running.
 490         if(&IDS::ids_is_running()) {
 491                 # Call suricatactrl to perform a reload.
 492                 &IDS::call_suricatactrl("reload");
 493         }
 494
 495         # Reload page.
 496         &reload();
 497
 498 # Download new ruleset.
 499 } elsif ($cgiparams{'RULESET'} eq $Lang::tr{'update ruleset'}) {
 500         # Check if the red device is active.
 501         unless (-e "${General::swroot}/red/active") {
 502                 $errormessage = "$Lang::tr{'could not download latest updates'} - $Lang::tr{'system is offline'}";
 503         }
 504
 505         # Check if enought free disk space is availabe.
 506         if(&IDS::checkdiskspace()) {
 507                 $errormessage = "$Lang::tr{'not enough disk space'}";
 508         }
 509
 510         # Check if any errors happend.
 511         unless ($errormessage) {
 512                 # Lock the webpage and print notice about downloading
 513                 # a new ruleset.
 514                 &working_notice("$Lang::tr{'snort working'}");
 515
 516                 # Call subfunction to download the ruleset.
 517                 if(&IDS::downloadruleset()) {
 518                         $errormessage = $Lang::tr{'could not download latest updates'};
 519
 520                         # Call function to store the errormessage.
 521                         &IDS::_store_error_message($errormessage);
 522
 523                         # Preform a reload of the page.
 524                         &reload();
 525                 } else {
 526                         # Call subfunction to launch oinkmaster.
 527                         &IDS::oinkmaster();
 528
 529                         # Check if the IDS is running.
 530                         if(&IDS::ids_is_running()) {
 531                                 # Call suricatactrl to perform a reload.
 532                                 &IDS::call_suricatactrl("reload");
 533                         }
 534
 535                         # Perform a reload of the page.
 536                         &reload();
 537                 }
 538         }
 539 # Save snort settings.
 540 } elsif ($cgiparams{'IDS'} eq $Lang::tr{'save'}) {
 541         my %oldidssettings;
 542         my $reload_page;
 543         my $monitored_zones = 0;
 544
 545         # Read-in current (old) IDS settings.
 546         &General::readhash("$IDS::ids_settings_file", \%oldidssettings);
 547
 548         # Prevent form name from been stored in conf file.
 549         delete $cgiparams{'IDS'};
 550
 551         # Check if the IDS should be enabled.
 552         if ($cgiparams{'ENABLE_IDS'} eq "on") {
 553                 # Check if any ruleset is available. Otherwise abort and display an error.
 554                 unless(%idsrules) {
 555                         $errormessage = $Lang::tr{'ids no ruleset available'};
 556                 }
 557
 558                 # Loop through the array of available interfaces.
 559                 foreach my $zone (@network_zones) {
 560                         # Convert interface name into upper case.
 561                         my $zone_upper = uc($zone);
 562
 563                         # Check if the IDS is enabled for this interaces.
 564                         if ($cgiparams{"ENABLE_IDS_$zone_upper"}) {
 565                                 # Increase count.
 566                                 $monitored_zones++;
 567                         }
 568                 }
 569
 570                 # Check if at least one zone should be monitored, or show an error.
 571                 unless ($monitored_zones >= 1) {
 572                         $errormessage = $Lang::tr{'ids no network zone'};
 573                 }
 574         }
 575
 576         # Go on if there are no error messages.
 577         if (!$errormessage) {
 578                 # Store settings into settings file.
 579                 &General::writehash("$IDS::ids_settings_file", \%cgiparams);
 580         }
 581
 582         # Generate file to store the home net.
 583         &IDS::generate_home_net_file();
 584
 585         # Temporary variable to set the ruleaction.
 586         # Default is "drop" to use suricata as IPS.
 587         my $ruleaction="drop";
 588
 589         # Check if the traffic only should be monitored.
 590         if($cgiparams{'MONITOR_TRAFFIC_ONLY'} eq 'on') {
 591                 # Switch the ruleaction to "alert".
 592                 # Suricata acts as an IDS only.
 593                 $ruleaction="alert";
 594         }
 595
 596         # Write the modify sid's file and pass the taken ruleaction.
 597         &IDS::write_modify_sids_file($ruleaction);
 598
 599         # Check if "MONITOR_TRAFFIC_ONLY" has been changed.
 600         if($cgiparams{'MONITOR_TRAFFIC_ONLY'} ne $oldidssettings{'MONITOR_TRAFFIC_ONLY'}) {
 601                 # Check if a ruleset exists.
 602                 if (%idsrules) {
 603                         # Lock the webpage and print message.
 604                         &working_notice("$Lang::tr{'snort working'}");
 605
 606                         # Call oinkmaster to alter the ruleset.
 607                         &IDS::oinkmaster();
 608
 609                         # Set reload_page to "True".
 610                         $reload_page="True";
 611                 }
 612         }
 613
 614         # Check if the IDS currently is running.
 615         if(&IDS::ids_is_running()) {
 616                 # Check if ENABLE_IDS is set to on.
 617                 if($cgiparams{'ENABLE_IDS'} eq "on") {
 618                         # Call suricatactrl to perform a reload of suricata.
 619                         &IDS::call_suricatactrl("reload");
 620                 } else {
 621                         # Call suricatactrl to stop suricata.
 622                         &IDS::call_suricatactrl("stop");
 623                 }
 624         } else {
 625                 # Call suricatactrl to start suricata.
 626                 &IDS::call_suricatactrl("start");
 627         }
 628
 629         # Check if the page should be reloaded.
 630         if ($reload_page) {
 631                 # Perform a reload of the page.
 632                 &reload();
 633         }
 634 }
 635
 636 # Read-in idssettings and rulesetsettings
 637 &General::readhash("$IDS::ids_settings_file", \%idssettings);
 638 &General::readhash("$IDS::rules_settings_file", \%rulessettings);
 639
 640 # If no autoupdate intervall has been configured yet, set default value.
 641 unless(exists($rulessettings{'AUTOUPDATE_INTERVAL'})) {
 642         # Set default to "weekly".
 643         $rulessettings{'AUTOUPDATE_INTERVAL'} = 'weekly';
 644 }
 645
 646 # Read-in ignored hosts.
 647 &General::readhasharray("$IDS::settingsdir/ignored", \%ignored);
 648
 649 $checked{'ENABLE_IDS'}{'off'} = '';
 650 $checked{'ENABLE_IDS'}{'on'} = '';
 651 $checked{'ENABLE_IDS'}{$idssettings{'ENABLE_IDS'}} = "checked='checked'";
 652 $checked{'MONITOR_TRAFFIC_ONLY'}{'off'} = '';
 653 $checked{'MONITOR_TRAFFIC_ONLY'}{'on'} = '';
 654 $checked{'MONITOR_TRAFFIC_ONLY'}{$idssettings{'MONITOR_TRAFFIC_ONLY'}} = "checked='checked'";
 655 $selected{'RULES'}{'nothing'} = '';
 656 $selected{'RULES'}{'community'} = '';
 657 $selected{'RULES'}{'emerging'} = '';
 658 $selected{'RULES'}{'registered'} = '';
 659 $selected{'RULES'}{'subscripted'} = '';
 660 $selected{'RULES'}{$rulessettings{'RULES'}} = "selected='selected'";
 661 $selected{'AUTOUPDATE_INTERVAL'}{'off'} = '';
 662 $selected{'AUTOUPDATE_INTERVAL'}{'daily'} = '';
 663 $selected{'AUTOUPDATE_INTERVAL'}{'weekly'} = '';
 664 $selected{'AUTOUPDATE_INTERVAL'}{$rulessettings{'AUTOUPDATE_INTERVAL'}} = "selected='selected'";
 665
 666 &Header::openpage($Lang::tr{'intrusion detection system'}, 1, '');
 667
 668 ### Java Script ###
 669 print"<script>\n";
 670
 671 # Java script variable declaration for show and hide.
 672 print"var show = \"$Lang::tr{'ids show'}\"\;\n";
 673 print"var hide = \"$Lang::tr{'ids hide'}\"\;\n";
 674
 675 print <<END
 676         // JQuery function to show/hide the text input field for
 677         // Oinkcode/Subscription code.
 678         \$(function() {
 679                 \$('#RULES').change(function(){
 680                         if(\$('#RULES').val() == 'registered') {
 681                                 \$('#code').show();
 682                         } else if(\$('#RULES').val() == 'subscripted') {
 683                                 \$('#code').show();
 684                         } else if(\$('#RULES').val() == 'emerging_pro') {
 685                                 \$('#code').show();
 686                         } else {
 687                                 \$('#code').hide();
 688                         }
 689                 });
 690         });
 691
 692         // Tiny java script function to show/hide the rules
 693         // of a given category.
 694         function showhide(tblname) {
 695                 \$("#" + tblname).toggle();
 696
 697                 // Get current content of the span element.
 698                 var content = document.getElementById("span_" + tblname);
 699
 700                 if (content.innerHTML === show) {
 701                         content.innerHTML = hide;
 702                 } else {
 703                         content.innerHTML = show;
 704                 }
 705         }
 706 </script>
 707 END
 708 ;
 709
 710 &Header::openbigbox('100%', 'left', '', $errormessage);
 711
 712 if ($errormessage) {
 713         &Header::openbox('100%', 'left', $Lang::tr{'error messages'});
 714         print "<class name='base'>$errormessage\n";
 715         print "&nbsp;</class>\n";
 716         &Header::closebox();
 717 }
 718
 719 # Draw current state of the IDS
 720 &Header::openbox('100%', 'left', $Lang::tr{'intrusion detection system'});
 721
 722 # Check if the IDS is running and obtain the process-id.
 723 my $pid = &IDS::ids_is_running();
 724
 725 # Display some useful information, if suricata daemon is running.
 726 if ($pid) {
 727         # Gather used memory.
 728         my $memory = &get_memory_usage($pid);
 729
 730         print <<END;
 731                 <table width='95%' cellspacing='0' class='tbl'>
 732                         <tr>
 733                                 <th bgcolor='$color{'color20'}' colspan='3' align='left'><strong>$Lang::tr{'intrusion detection'}</strong></th>
 734                         </tr>
 735
 736                         <tr>
 737                                 <td class='base'>$Lang::tr{'guardian daemon'}</td>
 738                                 <td align='center' colspan='2' width='75%' bgcolor='${Header::colourgreen}'><font color='white'><strong>$Lang::tr{'running'}</strong></font></td>
 739                         </tr>
 740
 741                         <tr>
 742                                 <td class='base'></td>
 743                                 <td bgcolor='$color{'color20'}' align='center'><strong>PID</strong></td>
 744                                 <td bgcolor='$color{'color20'}' align='center'><strong>$Lang::tr{'memory'}</strong></td>
 745                         </tr>
 746
 747                         <tr>
 748                                 <td class='base'></td>
 749                                 <td bgcolor='$color{'color22'}' align='center'>$pid</td>
 750                                 <td bgcolor='$color{'color22'}' align='center'>$memory KB</td>
 751                         </tr>
 752                 </table>
 753 END
 754 } else {
 755         # Otherwise display a hint that the service is not launched.
 756         print <<END;
 757                 <table width='95%' cellspacing='0' class='tbl'>
 758                         <tr>
 759                                 <th bgcolor='$color{'color20'}' colspan='3' align='left'><strong>$Lang::tr{'intrusion detection'}</strong></th>
 760                         </tr>
 761
 762                         <tr>
 763                                 <td class='base'>$Lang::tr{'guardian daemon'}</td>
 764                                 <td align='center' width='75%' bgcolor='${Header::colourred}'><font color='white'><strong>$Lang::tr{'stopped'}</strong></font></td>
 765                         </tr>
 766                 </table>
 767 END
 768 }
 769
 770 my $rulesdate;
 771
 772 # Check if a ruleset allready has been downloaded.
 773 if ( -f "$IDS::rulestarball"){
 774         # Call stat on the filename to obtain detailed information.
 775         my @Info = stat("$IDS::rulestarball");
 776
 777         # Grab details about the creation time.
 778         $rulesdate = localtime($Info[9]);
 779 }
 780
 781 # Only show this area, if a ruleset is present.
 782 if (%idsrules) {
 783
 784         print <<END
 785
 786         <br><br><h2>$Lang::tr{'settings'}</h2>
 787
 788         <form method='post' action='$ENV{'SCRIPT_NAME'}'>
 789                 <table width='100%' border='0'>
 790                         <tr>
 791                                 <td class='base' colspan='2'>
 792                                         <input type='checkbox' name='ENABLE_IDS' $checked{'ENABLE_IDS'}{'on'}>&nbsp;$Lang::tr{'ids enable'}
 793                                 </td>
 794
 795                                 <td class='base' colspan='2'>
 796                                         <input type='checkbox' name='MONITOR_TRAFFIC_ONLY' $checked{'MONITOR_TRAFFIC_ONLY'}{'on'}>&nbsp;$Lang::tr{'ids monitor traffic only'}
 797                         </td>
 798                         </tr>
 799
 800                         <tr>
 801                                 <td><br><br></td>
 802                                 <td><br><br></td>
 803                                 <td><br><br></td>
 804                                 <td><br><br></td>
 805                         </tr>
 806
 807                         <tr>
 808                                 <td colspan='4'><b>$Lang::tr{'ids monitored interfaces'}</b><br></td>
 809                         </tr>
 810
 811                         <tr>
 812 END
 813 ;
 814
 815         # Loop through the array of available networks and print config options.
 816         foreach my $zone (@network_zones) {
 817                 my $checked_input;
 818                 my $checked_forward;
 819
 820                 # Convert current zone name to upper case.
 821                 my $zone_upper = uc($zone);
 822
 823                 # Set zone name.
 824                 my $zone_name = $zone;
 825
 826                 # Dirty hack to get the correct language string for the red zone.
 827                 if ($zone eq "red") {
 828                         $zone_name = "red1";
 829                 }
 830
 831                 # Grab checkbox status from settings hash.
 832                 if ($idssettings{"ENABLE_IDS_$zone_upper"} eq "on") {
 833                         $checked_input = "checked = 'checked'";
 834                 }
 835
 836                 print "<td class='base' width='25%'>\n";
 837                 print "<input type='checkbox' name='ENABLE_IDS_$zone_upper' $checked_input>\n";
 838                 print "&nbsp;$Lang::tr{'enabled on'}<font color='$colourhash{$zone}'> $Lang::tr{$zone_name}</font>\n";
 839                 print "</td>\n";
 840         }
 841
 842 print <<END
 843                         </tr>
 844                 </table>
 845
 846                 <br><br>
 847
 848                 <table width='100%'>
 849                         <tr>
 850                                 <td align='right'><input type='submit' name='IDS' value='$Lang::tr{'save'}' /></td>
 851                         </tr>
 852                 </table>
 853         </form>
 854 END
 855 ;
 856
 857 }
 858
 859 &Header::closebox();
 860
 861 # Draw elements for ruleset configuration.
 862 &Header::openbox('100%', 'center', $Lang::tr{'ids ruleset settings'});
 863
 864 print <<END
 865 <form method='post' action='$ENV{'SCRIPT_NAME'}'>
 866         <table width='100%' border='0'>
 867                 <tr>
 868                         <td><b>$Lang::tr{'ids rules update'}</b></td>
 869                         <td><b>$Lang::tr{'ids automatic rules update'}</b></td>
 870                 </tr>
 871
 872                 <tr>
 873                         <td><select name='RULES' id='RULES'>
 874                                 <option value='emerging' $selected{'RULES'}{'emerging'} >$Lang::tr{'emerging rules'}</option>
 875                                 <option value='emerging_pro' $selected{'RULES'}{'emerging_pro'} >$Lang::tr{'emerging pro rules'}</option>
 876                                 <option value='community' $selected{'RULES'}{'community'} >$Lang::tr{'community rules'}</option>
 877                                 <option value='registered' $selected{'RULES'}{'registered'} >$Lang::tr{'registered user rules'}</option>
 878                                 <option value='subscripted' $selected{'RULES'}{'subscripted'} >$Lang::tr{'subscripted user rules'}</option>
 879                         </select>
 880                         </td>
 881
 882                         <td>
 883                                 <select name='AUTOUPDATE_INTERVAL'>
 884                                         <option value='off' $selected{'AUTOUPDATE_INTERVAL'}{'off'} >- $Lang::tr{'Disabled'} -</option>
 885                                         <option value='daily' $selected{'AUTOUPDATE_INTERVAL'}{'daily'} >$Lang::tr{'Daily'}</option>
 886                                         <option value='weekly' $selected{'AUTOUPDATE_INTERVAL'}{'weekly'} >$Lang::tr{'Weekly'}</option>
 887                                 </select>
 888                         </td>
 889                 </tr>
 890
 891                 <tr>
 892                         <td colspan='2'><br><br></td>
 893                 </tr>
 894
 895                 <tr style='display:none' id='code'>
 896                         <td colspan='2'>Oinkcode:&nbsp;<input type='text' size='40' name='OINKCODE' value='$rulessettings{'OINKCODE'}'></td>
 897                 </tr>
 898
 899                 <tr>
 900                         <td>&nbsp;</td>
 901
 902                         <td align='right'>
 903 END
 904 ;
 905                         # Check if a ruleset has been downloaded yet.
 906                         if (%idsrules) {
 907                                 # Display button to update the ruleset.
 908                                 print"<input type='submit' name='RULESET' value='$Lang::tr{'update ruleset'}'>\n";
 909                 }
 910 print <<END;
 911                                 <input type='submit' name='RULESET' value='$Lang::tr{'save'}'>
 912                         </td>
 913
 914                 </tr>
 915         </table>
 916 </form>
 917 END
 918 ;
 919
 920 &Header::closebox();
 921
 922 #
 923 # Whitelist / Ignorelist
 924 #
 925 &Header::openbox('100%', 'center', $Lang::tr{'guardian ignored hosts'});
 926
 927 print <<END;
 928         <table width='100%'>
 929                 <tr>
 930                         <td class='base' bgcolor='$color{'color20'}'><b>$Lang::tr{'ip address'}</b></td>
 931                         <td class='base' bgcolor='$color{'color20'}'><b>$Lang::tr{'remark'}</b></td>
 932                         <td class='base' colspan='3' bgcolor='$color{'color20'}'></td>
 933                 </tr>
 934 END
 935                 # Check if some hosts have been added to be ignored.
 936                 if (keys (%ignored)) {
 937                         my $col = "";
 938
 939                         # Loop through all entries of the hash.
 940                         while( (my $key) = each %ignored)  {
 941                                 # Assign data array positions to some nice variable names.
 942                                 my $address = $ignored{$key}[0];
 943                                 my $remark = $ignored{$key}[1];
 944                                 my $status  = $ignored{$key}[2];
 945
 946                                 # Check if the key (id) number is even or not.
 947                                 if ($cgiparams{'ID'} eq $key) {
 948                                         $col="bgcolor='${Header::colouryellow}'";
 949                                 } elsif ($key % 2) {
 950                                         $col="bgcolor='$color{'color22'}'";
 951                                 } else {
 952                                         $col="bgcolor='$color{'color20'}'";
 953                                 }
 954
 955                                 # Choose icon for the checkbox.
 956                                 my $gif;
 957                                 my $gdesc;
 958
 959                                 # Check if the status is enabled and select the correct image and description.
 960                                 if ($status eq 'enabled' ) {
 961                                         $gif = 'on.gif';
 962                                         $gdesc = $Lang::tr{'click to disable'};
 963                                 } else {
 964                                         $gif = 'off.gif';
 965                                         $gdesc = $Lang::tr{'click to enable'};
 966                                 }
 967
 968 print <<END;
 969                                 <tr>
 970                                         <td width='20%' class='base' $col>$address</td>
 971                                         <td width='65%' class='base' $col>$remark</td>
 972
 973                                         <td align='center' $col>
 974                                                 <form method='post' action='$ENV{'SCRIPT_NAME'}'>
 975                                                         <input type='hidden' name='WHITELIST' value='$Lang::tr{'toggle enable disable'}' />
 976                                                         <input type='image' name='$Lang::tr{'toggle enable disable'}' src='/images/$gif' alt='$gdesc' title='$gdesc' />
 977                                                         <input type='hidden' name='ID' value='$key' />
 978                                                 </form>
 979                                         </td>
 980
 981                                         <td align='center' $col>
 982                                                 <form method='post' action='$ENV{'SCRIPT_NAME'}'>
 983                                                         <input type='hidden' name='WHITELIST' value='$Lang::tr{'edit'}' />
 984                                                         <input type='image' name='$Lang::tr{'edit'}' src='/images/edit.gif' alt='$Lang::tr{'edit'}' title='$Lang::tr{'edit'}' />
 985                                                         <input type='hidden' name='ID' value='$key' />
 986                                                 </form>
 987                                         </td>
 988
 989                                         <td align='center' $col>
 990                                                 <form method='post' name='$key' action='$ENV{'SCRIPT_NAME'}'>
 991                                                         <input type='image' name='$Lang::tr{'remove'}' src='/images/delete.gif' title='$Lang::tr{'remove'}' alt='$Lang::tr{'remove'}'>
 992                                                         <input type='hidden' name='ID' value='$key'>
 993                                                         <input type='hidden' name='WHITELIST' value='$Lang::tr{'remove'}'>
 994                                                 </form>
 995                                         </td>
 996                                 </tr>
 997 END
 998                         }
 999                 } else {
1000                         # Print notice that currently no hosts are ignored.
1001                         print "<tr>\n";
1002                         print "<td class='base' colspan='2'>$Lang::tr{'guardian no entries'}</td>\n";
1003                         print "</tr>\n";
1004                 }
1005
1006         print "</table>\n";
1007
1008         # Section to add new elements or edit existing ones.
1009 print <<END;
1010         <br>
1011         <hr>
1012         <br>
1013
1014         <div align='center'>
1015                 <table width='100%'>
1016 END
1017
1018         # Assign correct headline and button text.
1019         my $buttontext;
1020         my $entry_address;
1021         my $entry_remark;
1022
1023         # Check if an ID (key) has been given, in this case an existing entry should be edited.
1024         if ($cgiparams{'ID'} ne '') {
1025                 $buttontext = $Lang::tr{'update'};
1026                         print "<tr><td class='boldbase' colspan='3'><b>$Lang::tr{'update'}</b></td></tr>\n";
1027
1028                         # Grab address and remark for the given key.
1029                         $entry_address = $ignored{$cgiparams{'ID'}}[0];
1030                         $entry_remark = $ignored{$cgiparams{'ID'}}[1];
1031                 } else {
1032                         $buttontext = $Lang::tr{'add'};
1033                         print "<tr><td class='boldbase' colspan='3'><b>$Lang::tr{'dnsforward add a new entry'}</b></td></tr>\n";
1034                 }
1035
1036 print <<END;
1037                         <form method='post' action='$ENV{'SCRIPT_NAME'}'>
1038                         <input type='hidden' name='ID' value='$cgiparams{'ID'}'>
1039                         <tr>
1040                                 <td width='30%'>$Lang::tr{'ip address'}: </td>
1041                                 <td width='50%'><input type='text' name='IGNORE_ENTRY_ADDRESS' value='$entry_address' size='24' /></td>
1042
1043                                 <td width='30%'>$Lang::tr{'remark'}: </td>
1044                                 <td wicth='50%'><input type='text' name=IGNORE_ENTRY_REMARK value='$entry_remark' size='24' /></td>
1045                                 <td align='center' width='20%'><input type='submit' name='WHITELIST' value='$buttontext' /></td>
1046                         </tr>
1047                         </form>
1048                 </table>
1049         </div>
1050 END
1051
1052 &Header::closebox();
1053
1054 # Only show the section for configuring the ruleset if one is present.
1055 if (%idsrules) {
1056         &Header::openbox('100%', 'LEFT', $Lang::tr{'intrusion detection system rules'});
1057
1058                 print"<form method='POST' action='$ENV{'SCRIPT_NAME'}'>\n";
1059
1060                 # Output display table for rule files
1061                 print "<table width='100%'>\n";
1062
1063                 # Loop over each rule file
1064                 foreach my $rulefile (sort keys(%idsrules)) {
1065                         my $rulechecked = '';
1066
1067                         # Check if rule file is enabled
1068                         if ($idsrules{$rulefile}{'Rulefile'}{'State'} eq 'on') {
1069                                 $rulechecked = 'CHECKED';
1070                         }
1071
1072                         # Convert rulefile name into category name.
1073                         my $categoryname = &_rulefile_to_category($rulefile);
1074
1075                         # Table and rows for the rule files.
1076                         print"<tr>\n";
1077                         print"<td class='base' width='5%'>\n";
1078                         print"<input type='checkbox' name='$rulefile' $rulechecked>\n";
1079                         print"</td>\n";
1080                         print"<td class='base' width='90%'><b>$rulefile</b></td>\n";
1081                         print"<td class='base' width='5%' align='right'>\n";
1082                         print"<a href=\"javascript:showhide('$categoryname')\"><span id='span_$categoryname'>$Lang::tr{'ids show'}</span></a>\n";
1083                         print"</td>\n";
1084                         print"</tr>\n";
1085
1086                         # Rows which will be hidden per default and will contain the single rules.
1087                         print"<tr  style='display:none' id='$categoryname'>\n";
1088                         print"<td colspan='3'>\n";
1089
1090                         # Local vars
1091                         my $lines;
1092                         my $rows;
1093                         my $col;
1094
1095                         # New table for the single rules.
1096                         print "<table width='100%'>\n";
1097
1098                         # Loop over rule file rules
1099                         foreach my $sid (sort {$a <=> $b} keys(%{$idsrules{$rulefile}})) {
1100                                 # Local vars
1101                                 my $ruledefchecked = '';
1102
1103                                 # Skip rulefile itself.
1104                                 next if ($sid eq "Rulefile");
1105
1106                                 # If 2 rules have been displayed, start a new row
1107                                 if (($lines % 2) == 0) {
1108                                         print "</tr><tr>\n";
1109
1110                                         # Increase rows by once.
1111                                         $rows++;
1112                                 }
1113
1114                                 # Colour lines.
1115                                 if ($rows % 2) {
1116                                         $col="bgcolor='$color{'color20'}'";
1117                                 } else {
1118                                         $col="bgcolor='$color{'color22'}'";
1119                                 }
1120
1121                                 # Set rule state
1122                                 if ($idsrules{$rulefile}{$sid}{'State'} eq 'on') {
1123                                         $ruledefchecked = 'CHECKED';
1124                                 }
1125
1126                                 # Create rule checkbox and display rule description
1127                                 print "<td class='base' width='5%' align='right' $col>\n";
1128                                 print "<input type='checkbox' NAME='$sid' $ruledefchecked>\n";
1129                                 print "</td>\n";
1130                                 print "<td class='base' width='45%' $col>$idsrules{$rulefile}{$sid}{'Description'}</td>";
1131
1132                                 # Increment rule count
1133                                 $lines++;
1134                         }
1135
1136                         # If do not have a second rule for row, create empty cell
1137                         if (($lines % 2) != 0) {
1138                                 print "<td class='base'></td>";
1139                         }
1140
1141                         # Close display table
1142                         print "</tr></table></td></tr>";
1143                 }
1144
1145                 # Close display table
1146                 print "</table>";
1147
1148 print <<END
1149 <table width='100%'>
1150 <tr>
1151         <td width='100%' align='right'><input type='submit' name='RULESET' value='$Lang::tr{'update'}'>
1152                 &nbsp; <!-- space for future online help link -->
1153         </td>
1154 </tr>
1155 </table>
1156 </form>
1157 END
1158 ;
1159         &Header::closebox();
1160 }
1161
1162 &Header::closebigbox();
1163 &Header::closepage();
1164
1165 #
1166 ## A function to display a notice, to lock the webpage and
1167 ## tell the user which action currently will be performed.
1168 #
1169 sub working_notice ($) {
1170         my ($message) = @_;
1171
1172         &Header::openpage($Lang::tr{'intrusion detection system'}, 1, '');
1173         &Header::openbigbox('100%', 'left', '', $errormessage);
1174         &Header::openbox( 'Waiting', 1,);
1175                 print <<END;
1176                         <table>
1177                                 <tr>
1178                                         <td><img src='/images/indicator.gif' alt='$Lang::tr{'aktiv'}' /></td>
1179                                         <td>$message</td>
1180                                 </tr>
1181                         </table>
1182 END
1183         &Header::closebox();
1184         &Header::closebigbox();
1185         &Header::closepage();
1186 }
1187
1188 #
1189 ## A tiny function to perform a reload of the webpage after one second.
1190 #
1191 sub reload () {
1192         print "<meta http-equiv='refresh' content='1'>\n";
1193
1194         # Stop the script.
1195         exit;
1196 }
1197
1198 #
1199 ## Private function to read-in and parse rules of a given rulefile.
1200 #
1201 ## The given file will be read, parsed and all valid rules will be stored by ID,
1202 ## message/description and it's state in the idsrules hash.
1203 #
1204 sub readrulesfile ($) {
1205         my $rulefile = shift;
1206
1207         # Open rule file and read in contents
1208         open(RULEFILE, "$IDS::rulespath/$rulefile") or die "Unable to read $rulefile!";
1209
1210         # Store file content in an array.
1211         my @lines = <RULEFILE>;
1212
1213         # Close file.
1214         close(RULEFILE);
1215
1216         # Loop over rule file contents
1217         foreach my $line (@lines) {
1218                 # Remove whitespaces.
1219                 chomp $line;
1220
1221                 # Skip blank  lines.
1222                 next if ($line =~ /^\s*$/);
1223
1224                 # Local vars.
1225                 my $sid;
1226                 my $msg;
1227
1228                 # Gather rule sid and message from the ruleline.
1229                 if ($line =~ m/.*msg:\"(.*?)\"\; .* sid:(.*?); /) {
1230                         $msg = $1;
1231                         $sid = $2;
1232
1233                         # Check if a rule has been found.
1234                         if ($sid && $msg) {
1235                                 # Add rule to the idsrules hash.
1236                                 $idsrules{$rulefile}{$sid}{'Description'} = $msg;
1237
1238                                 # Grab status of the rule. Check if ruleline starts with a "dash".
1239                                 if ($line =~ /^\#/) {
1240                                         # If yes, the rule is disabled.
1241                                         $idsrules{$rulefile}{$sid}{'State'} = "off";
1242                                 } else {
1243                                         # Otherwise the rule is enabled.
1244                                         $idsrules{$rulefile}{$sid}{'State'} = "on";
1245                                 }
1246                         }
1247                 }
1248         }
1249 }
1250
1251 #
1252 ## Function to get the used memory of a given process-id.
1253 #
1254 sub get_memory_usage($) {
1255         my ($pid) = @_;
1256
1257         my $memory = 0;
1258
1259         # Try to open the status file for the given process-id on the pseudo
1260         # file system proc.
1261         if (open(FILE, "/proc/$pid/status")) {
1262                 # Loop through the entire file.
1263                 while (<FILE>) {
1264                         # Splitt current line content and store them into variables.
1265                         my ($key, $value) = split(":", $_, 2);
1266
1267                         # Check if the current key is the one which contains the memory usage.
1268                         # The wanted one is VmRSS which contains the Real-memory (resident set)
1269                         # of the entire process.
1270                         if ($key eq "VmRSS") {
1271                                 # Found the memory usage add it to the memory variable.
1272                                 $memory += $value;
1273
1274                                 # Break the loop.
1275                                 last;
1276                         }
1277                 }
1278
1279                 # Close file handle.
1280                 close(FILE);
1281
1282                 # Return memory usage.
1283                 return $memory;
1284         }
1285
1286         # If the file could not be open, return nothing.
1287         return;
1288 }
1289
1290 #
1291 ## Function to read-in the given enabled or disables sids file.
1292 #
1293 sub read_enabled_disabled_sids_file($) {
1294         my ($file) = @_;
1295
1296         # Temporary hash to store the sids and their state. It will be
1297         # returned at the end of this function.
1298         my %temphash;
1299
1300         # Open the given filename.
1301         open(FILE, "$file") or die "Could not open $file. $!\n";
1302
1303         # Loop through the file.
1304         while(<FILE>) {
1305                 # Remove newlines.
1306                 chomp $_;
1307
1308                 # Skip blank lines.
1309                 next if ($_ =~ /^\s*$/);
1310
1311                 # Skip coments.
1312                 next if ($_ =~ /^\#/);
1313
1314                 # Splitt line into sid and state part.
1315                 my ($state, $sid) = split(" ", $_);
1316
1317                 # Skip line if the sid is not numeric.
1318                 next unless ($sid =~ /\d+/ );
1319
1320                 # Check if the sid was enabled.
1321                 if ($state eq "enablesid") {
1322                         # Add the sid and its state as enabled to the temporary hash.
1323                         $temphash{$sid} = "enabled";
1324                 # Check if the sid was disabled.
1325                 } elsif ($state eq "disablesid") {
1326                         # Add the sid and its state as disabled to the temporary hash.
1327                         $temphash{$sid} = "disabled";
1328                 # Invalid state - skip the current sid and state.
1329                 } else {
1330                         next;
1331                 }
1332         }
1333
1334         # Close filehandle.
1335         close(FILE);
1336
1337         # Return the hash.
1338         return %temphash;
1339 }
1340
1341 #
1342 ## Private function to convert a given rulefile to a category name.
1343 ## ( No file extension anymore and if the name contained a dot, it
1344 ## would be replaced by a underline sign.)
1345 #
1346 sub _rulefile_to_category($) {
1347         my ($filename) = @_;
1348
1349         # Splitt the filename into single chunks and store them in a
1350         # temorary array.
1351         my @parts = split(/\./, $filename);
1352
1353         # Return / Remove last element of the temporary array.
1354         # This removes the file extension.
1355         pop @parts;
1356
1357         # Join together the single elements of the temporary array.
1358         # If these are more than one, use a "underline" for joining.
1359         my $category = join '_', @parts;
1360
1361         # Return the converted filename.
1362         return $category;
1363 }