config/cfgroot/ids-functions.pl

   1 #!/usr/bin/perl -w
   2 ############################################################################
   3 #                                                                          #
   4 # This file is part of the IPFire Firewall.                                #
   5 #                                                                          #
   6 # IPFire is free software; you can redistribute it and/or modify           #
   7 # it under the terms of the GNU General Public License as published by     #
   8 # the Free Software Foundation; either version 2 of the License, or        #
   9 # (at your option) any later version.                                      #
  10 #                                                                          #
  11 # IPFire is distributed in the hope that it will be useful,                #
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of           #
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            #
  14 # GNU General Public License for more details.                             #
  15 #                                                                          #
  16 # You should have received a copy of the GNU General Public License        #
  17 # along with IPFire; if not, write to the Free Software                    #
  18 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA #
  19 #                                                                          #
  20 # Copyright (C) 2018-2019 IPFire Team <info@ipfire.org>                    #
  21 #                                                                          #
  22 ############################################################################
  23
  24 use strict;
  25
  26 package IDS;
  27
  28 require '/var/ipfire/general-functions.pl';
  29 require "${General::swroot}/network-functions.pl";
  30 require "${General::swroot}/suricata/ruleset-sources";
  31
  32 # Location where all config and settings files are stored.
  33 our $settingsdir = "${General::swroot}/suricata";
  34
  35 # File where the used rulefiles are stored.
  36 our $used_rulefiles_file = "$settingsdir/suricata-used-rulefiles.yaml";
  37
  38 # File where the addresses of the homenet are stored.
  39 our $homenet_file = "$settingsdir/suricata-homenet.yaml";
  40
  41 # File where the addresses of the used DNS servers are stored.
  42 our $dns_servers_file = "$settingsdir/suricata-dns-servers.yaml";
  43
  44 # File where the HTTP ports definition is stored.
  45 our $http_ports_file = "$settingsdir/suricata-http-ports.yaml";
  46
  47 # File which contains the enabled sids.
  48 our $enabled_sids_file = "$settingsdir/oinkmaster-enabled-sids.conf";
  49
  50 # File which contains the disabled sids.
  51 our $disabled_sids_file = "$settingsdir/oinkmaster-disabled-sids.conf";
  52
  53 # File which contains wheater the rules should be changed.
  54 our $modify_sids_file = "$settingsdir/oinkmaster-modify-sids.conf";
  55
  56 # File which stores the configured IPS settings.
  57 our $ids_settings_file = "$settingsdir/settings";
  58
  59 # DEPRECATED - File which stores the configured rules-settings.
  60 our $rules_settings_file = "$settingsdir/rules-settings";
  61
  62 # File which stores the used and configured ruleset providers.
  63 our $providers_settings_file = "$settingsdir/providers-settings";
  64
  65 # File which stores the configured settings for whitelisted addresses.
  66 our $ignored_file = "$settingsdir/ignored";
  67
  68 # DEPRECATED - Location and name of the tarball which contains the ruleset.
  69 our $rulestarball = "/var/tmp/idsrules.tar.gz";
  70
  71 # Location where the downloaded rulesets are stored.
  72 our $dl_rules_path = "/var/tmp";
  73
  74 # File to store any errors, which also will be read and displayed by the wui.
  75 our $storederrorfile = "/tmp/ids_storederror";
  76
  77 # File to lock the WUI, while the autoupdate script runs.
  78 our $ids_page_lock_file = "/tmp/ids_page_locked";
  79
  80 # Location where the rulefiles are stored.
  81 our $rulespath = "/var/lib/suricata";
  82
  83 # Location of the classification file.
  84 our $classification_file = "$rulespath/classification.config";
  85
  86 # Location of the sid to msg mappings file.
  87 our $sid_msg_file = "$rulespath/sid-msg.map";
  88
  89 # Location to store local rules. This file will not be touched.
  90 our $local_rules_file = "$rulespath/local.rules";
  91
  92 # File which contains the rules to whitelist addresses on suricata.
  93 our $whitelist_file = "$rulespath/whitelist.rules";
  94
  95 # File which contains a list of all supported ruleset sources.
  96 # (Sourcefire, Emergingthreads, etc..)
  97 our $rulesetsourcesfile = "$settingsdir/ruleset-sources";
  98
  99 # The pidfile of the IDS.
 100 our $idspidfile = "/var/run/suricata.pid";
 101
 102 # Location of suricatactrl.
 103 my $suricatactrl = "/usr/local/bin/suricatactrl";
 104
 105 # Prefix for each downloaded ruleset.
 106 my $dl_rulesfile_prefix = "idsrules";
 107
 108 # Temporary directory where the rulesets will be extracted.
 109 my $tmp_directory = "/tmp/ids_tmp";
 110
 111 # Temporary directory where the extracted rules files will be stored.
 112 my $tmp_rules_directory = "$tmp_directory/rules";
 113
 114 # Temporary directory where the extracted additional config files will be stored.
 115 my $tmp_conf_directory = "$tmp_directory/conf";
 116
 117 # Array with allowed commands of suricatactrl.
 118 my @suricatactrl_cmds = ( 'start', 'stop', 'restart', 'reload', 'fix-rules-dir', 'cron' );
 119
 120 # Array with supported cron intervals.
 121 my @cron_intervals = ('off', 'daily', 'weekly' );
 122
 123 # Array which contains the HTTP ports, which statically will be declared as HTTP_PORTS in the
 124 # http_ports_file.
 125 my @http_ports = ('80', '81');
 126
 127 # Hash which allows to convert the download type (dl_type) to a file suffix.
 128 my %dl_type_to_suffix = (
 129         "archive" => ".tar.gz",
 130         "plain" => ".rules",
 131 );
 132
 133 #
 134 ## Function to check and create all IDS related files, if the does not exist.
 135 #
 136 sub check_and_create_filelayout() {
 137         # Check if the files exist and if not, create them.
 138         unless (-f "$enabled_sids_file") { &create_empty_file($enabled_sids_file); }
 139         unless (-f "$disabled_sids_file") { &create_empty_file($disabled_sids_file); }
 140         unless (-f "$modify_sids_file") { &create_empty_file($modify_sids_file); }
 141         unless (-f "$used_rulefiles_file") { &create_empty_file($used_rulefiles_file); }
 142         unless (-f "$ids_settings_file") { &create_empty_file($ids_settings_file); }
 143         unless (-f "$providers_settings_file") { &create_empty_file($providers_settings_file); }
 144         unless (-f "$ignored_file") { &create_empty_file($ignored_file); }
 145         unless (-f "$whitelist_file" ) { &create_empty_file($whitelist_file); }
 146 }
 147
 148 #
 149 ## Function to get a list of all available ruleset providers.
 150 ##
 151 ## They will be returned as a sorted array.
 152 #
 153 sub get_ruleset_providers() {
 154         my @providers;
 155
 156         # Loop through the hash of providers.
 157         foreach my $provider ( keys %IDS::Ruleset::Providers ) {
 158                 # Add the provider to the array.
 159                 push(@providers, $provider);
 160         }
 161
 162         # Sort and return the array.
 163         return sort(@providers);
 164 }
 165
 166 #
 167 ## Function for checking if at least 300MB of free disk space are available
 168 ## on the "/var" partition.
 169 #
 170 sub checkdiskspace () {
 171         # Call diskfree to gather the free disk space of /var.
 172         my @df = &General::system_output("/bin/df", "-B", "M", "/var");
 173
 174         # Loop through the output.
 175         foreach my $line (@df) {
 176                 # Ignore header line.
 177                 next if $line =~ m/^Filesystem/;
 178
 179                 # Search for a line with the device information.
 180                 if ($line =~ m/dev/ ) {
 181                         # Split the line into single pieces.
 182                         my @values = split(' ', $line);
 183                         my ($filesystem, $blocks, $used, $available, $used_perenctage, $mounted_on) = @values;
 184
 185                         # Check if the available disk space is more than 300MB.
 186                         if ($available < 300) {
 187                                 # Log error to syslog.
 188                                 &_log_to_syslog("Not enough free disk space on /var. Only $available MB from 300 MB available.");
 189
 190                                 # Exit function and return "1" - False.
 191                                 return 1;
 192                         }
 193                 }
 194         }
 195
 196         # Everything okay, return nothing.
 197         return;
 198 }
 199
 200 #
 201 ## This function is responsible for downloading the configured IDS rulesets or if no one is specified
 202 ## all configured rulesets will be downloaded.
 203 ##
 204 ## * At first it gathers all configured ruleset providers, initialize the downloader and sets an
 205 ##   upstream proxy if configured.
 206 ## * After that, the given ruleset or in case all rulesets should be downloaded, it will determine wether it
 207 ##   is enabled or not.
 208 ## * The next step will be to generate the final download url, by obtaining the URL for the desired
 209 ##   ruleset, add the settings for the upstream proxy.
 210 ## * Finally the function will grab all the rules files or tarballs from the servers.
 211 #
 212 sub downloadruleset ($) {
 213         my ($provider) = @_;
 214
 215         # If no provider is given default to "all".
 216         $provider //= 'all';
 217
 218         # Hash to store the providers and access id's, for which rules should be downloaded.
 219         my %sheduled_providers = ();
 220
 221         # Get used provider settings.
 222         my %used_providers = ();
 223         &General::readhasharray("$providers_settings_file", \%used_providers);
 224
 225         # Check if a ruleset has been configured.
 226         unless(%used_providers) {
 227                 # Log that no ruleset has been configured and abort.
 228                 &_log_to_syslog("No ruleset provider has been configured.");
 229
 230                 # Return "1".
 231                 return 1;
 232         }
 233
 234         # Read proxysettings.
 235         my %proxysettings=();
 236         &General::readhash("${General::swroot}/proxy/settings", \%proxysettings);
 237
 238         # Load required perl module to handle the download.
 239         use LWP::UserAgent;
 240
 241         # Init the download module.
 242         my $downloader = LWP::UserAgent->new;
 243
 244         # Set timeout to 10 seconds.
 245         $downloader->timeout(10);
 246
 247         # Check if an upstream proxy is configured.
 248         if ($proxysettings{'UPSTREAM_PROXY'}) {
 249                 my $proxy_url;
 250
 251                 $proxy_url = "http://";
 252
 253                 # Check if the proxy requires authentication.
 254                 if (($proxysettings{'UPSTREAM_USER'}) && ($proxysettings{'UPSTREAM_PASSWORD'})) {
 255                         $proxy_url .= "$proxysettings{'UPSTREAM_USER'}\:$proxysettings{'UPSTREAM_PASSWORD'}\@";
 256                 }
 257
 258                 # Add proxy server address and port.
 259                 $proxy_url .= $proxysettings{'UPSTREAM_PROXY'};
 260
 261                 # Setup proxy settings.
 262                 $downloader->proxy(['http', 'https'], $proxy_url);
 263         }
 264
 265         # Loop through the hash of configured providers.
 266         foreach my $id ( keys %used_providers ) {
 267                 # Skip providers which are not enabled.
 268                 next if ($used_providers{$id}[3] ne "enabled");
 269
 270                 # Obtain the provider handle.
 271                 my $provider_handle = $used_providers{$id}[0];
 272
 273                 # Handle update off all providers.
 274                 if (($provider eq "all") || ($provider_handle eq "$provider")) {
 275                         # Add provider handle and it's id to the hash of sheduled providers.
 276                         $sheduled_providers{$provider_handle} = $id;
 277                 }
 278         }
 279
 280         # Loop through the hash of sheduled providers.
 281         foreach my $provider ( keys %sheduled_providers) {
 282                 # Grab the download url for the provider.
 283                 my $url = $IDS::Ruleset::Providers{$provider}{'dl_url'};
 284
 285                 # Check if the provider requires a subscription.
 286                 if ($IDS::Ruleset::Providers{$provider}{'requires_subscription'} eq "True") {
 287                         # Grab the previously stored access id for the provider from hash.
 288                         my $id = $sheduled_providers{$provider};
 289
 290                         # Grab the subscription code.
 291                         my $subscription_code = $used_providers{$id}[1];
 292
 293                         # Add the subscription code to the download url.
 294                         $url =~ s/\<subscription_code\>/$subscription_code/g;
 295
 296                 }
 297
 298                 # Abort if no url could be determined for the provider.
 299                 unless ($url) {
 300                         # Log error and abort.
 301                         &_log_to_syslog("Unable to gather a download URL for the selected ruleset provider.");
 302                         return 1;
 303                 }
 304
 305                 # Variable to store the filesize of the remote object.
 306                 my $remote_filesize;
 307
 308                 # The sourcfire (snort rules) does not allow to send "HEAD" requests, so skip this check
 309                 # for this webserver.
 310                 #
 311                 # Check if the ruleset source contains "snort.org".
 312                 unless ($url =~ /\.snort\.org/) {
 313                         # Pass the requrested url to the downloader.
 314                         my $request = HTTP::Request->new(HEAD => $url);
 315
 316                         # Accept the html header.
 317                         $request->header('Accept' => 'text/html');
 318
 319                         # Perform the request and fetch the html header.
 320                         my $response = $downloader->request($request);
 321
 322                         # Check if there was any error.
 323                         unless ($response->is_success) {
 324                                 # Obtain error.
 325                                 my $error = $response->status_line();
 326
 327                                 # Log error message.
 328                                 &_log_to_syslog("Unable to download the ruleset. \($error\)");
 329
 330                                 # Return "1" - false.
 331                                 return 1;
 332                         }
 333
 334                         # Assign the fetched header object.
 335                         my $header = $response->headers();
 336
 337                         # Grab the remote file size from the object and store it in the
 338                         # variable.
 339                         $remote_filesize = $header->content_length;
 340                 }
 341
 342                 # Load perl module to deal with temporary files.
 343                 use File::Temp;
 344
 345                 # Generate temporary file name, located in "/var/tmp" and with a suffix of ".tmp".
 346                 my $tmp = File::Temp->new( SUFFIX => ".tmp", DIR => "/var/tmp/", UNLINK => 0 );
 347                 my $tmpfile = $tmp->filename();
 348
 349                 # Pass the requested url to the downloader.
 350                 my $request = HTTP::Request->new(GET => $url);
 351
 352                 # Perform the request and save the output into the tmpfile.
 353                 my $response = $downloader->request($request, $tmpfile);
 354
 355                 # Check if there was any error.
 356                 unless ($response->is_success) {
 357                         # Obtain error.
 358                         my $error = $response->content;
 359
 360                         # Log error message.
 361                         &_log_to_syslog("Unable to download the ruleset. \($error\)");
 362
 363                         # Return "1" - false.
 364                         return 1;
 365                 }
 366
 367                 # Load perl stat module.
 368                 use File::stat;
 369
 370                 # Perform stat on the tmpfile.
 371                 my $stat = stat($tmpfile);
 372
 373                 # Grab the local filesize of the downloaded tarball.
 374                 my $local_filesize = $stat->size;
 375
 376                 # Check if both file sizes match.
 377                 if (($remote_filesize) && ($remote_filesize ne $local_filesize)) {
 378                         # Log error message.
 379                         &_log_to_syslog("Unable to completely download the ruleset. ");
 380                         &_log_to_syslog("Only got $local_filesize Bytes instead of $remote_filesize Bytes. ");
 381
 382                         # Delete temporary file.
 383                         unlink("$tmpfile");
 384
 385                         # Return "1" - false.
 386                         return 1;
 387                 }
 388
 389                 # Genarate and assign file name and path to store the downloaded rules file.
 390                 my $dl_rulesfile = &_get_dl_rulesfile($provider);
 391
 392                 # Check if a file name could be obtained.
 393                 unless ($dl_rulesfile) {
 394                         # Log error message.
 395                         &_log_to_syslog("Unable to store the downloaded rules file. ");
 396
 397                         # Delete downloaded temporary file.
 398                         unlink("$tmpfile");
 399
 400                         # Return "1" - false.
 401                 }
 402
 403                 # Load file copy module, which contains the move() function.
 404                 use File::Copy;
 405
 406                 # Overwrite the may existing rulefile or tarball with the downloaded one.
 407                 move("$tmpfile", "$dl_rulesfile");
 408
 409                 # Delete temporary file.
 410                 unlink("$tmpfile");
 411
 412                 # Set correct ownership for the tarball.
 413                 set_ownership("$dl_rulesfile");
 414         }
 415
 416         # If we got here, everything worked fine. Return nothing.
 417         return;
 418 }
 419
 420 #
 421 ## Function to extract a given ruleset.
 422 #
 423 sub extractruleset ($) {
 424         my ($provider) = @_;
 425
 426         # Load perl module to deal with archives.
 427         use Archive::Tar;
 428
 429         # Load perl module to deal with files and path.
 430         use File::Basename;
 431
 432         # Get full path and downloaded rulesfile for the given provider.
 433         my $tarball = &_get_dl_rulesfile($provider);
 434
 435         # Check if the file exists.
 436         unless (-f $tarball) {
 437                 &_log_to_syslog("Could not extract ruleset file: $tarball");
 438
 439                 # Return nothing.
 440                 return;
 441         }
 442
 443         # Check if the temporary directories exist, otherwise create them.
 444         mkdir("$tmp_directory") unless (-d "$tmp_directory");
 445         mkdir("$tmp_rules_directory") unless (-d "$tmp_rules_directory");
 446         mkdir("$tmp_conf_directory") unless (-d "$tmp_conf_directory");
 447
 448         # Initialize the tar module.
 449         my $tar = Archive::Tar->new($tarball);
 450
 451         # Get the filelist inside the tarball.
 452         my @packed_files = $tar->list_files;
 453
 454         # Loop through the filelist.
 455         foreach my $packed_file (@packed_files) {
 456                 my $destination;
 457
 458                 # Splitt the packed file into chunks.
 459                 my $file = fileparse($packed_file);
 460
 461                 # Handle msg-id.map file.
 462                 if ("$file" eq "sid-msg.map") {
 463                         # Set extract destination to temporary config_dir.
 464                         $destination = "$tmp_conf_directory/$provider\-sid-msg.map";
 465                 # Handle classification.conf
 466                 } elsif ("$file" eq "classification.config") {
 467                         # Set extract destination to temporary config_dir.
 468                         $destination = "$tmp_conf_directory/$provider\-classification.config";
 469                 # Handle rules files.
 470                 } elsif ($file =~ m/\.rules$/) {
 471                         my $rulesfilename;
 472
 473                         # Splitt the filename into chunks.
 474                         my @filename = split("-", $file);
 475
 476                         # Reverse the array.
 477                         @filename = reverse(@filename);
 478
 479                         # Get the amount of elements in the array.
 480                         my $elements = @filename;
 481
 482                         # Remove last element of the hash.
 483                         # It contains the vendor name, which will be replaced.
 484                         if ($elements >= 3) {
 485                                 # Remove last element from hash.
 486                                 pop(@filename);
 487                         }
 488
 489                         # Check if the last element of the filename does not
 490                         # contain the providers name.
 491                         if ($filename[-1] ne "$provider") {
 492                                 # Add provider name as last element.
 493                                 push(@filename, $provider);
 494                         }
 495
 496                         # Reverse the array back.
 497                         @filename = reverse(@filename);
 498
 499                         # Generate the name for the rulesfile.
 500                         $rulesfilename = join("-", @filename);
 501
 502                         # Set extract destination to temporaray rules_dir.
 503                         $destination = "$tmp_rules_directory/$rulesfilename";
 504                 } else {
 505                         # Skip all other files.
 506                         next;
 507                 }
 508
 509                 # Extract the file to the temporary directory.
 510                 $tar->extract_file("$packed_file", "$destination");
 511         }
 512 }
 513
 514 #
 515 ## A tiny wrapper function to call the oinkmaster script.
 516 #
 517 sub oinkmaster () {
 518         # Check if the files in rulesdir have the correct permissions.
 519         &_check_rulesdir_permissions();
 520
 521         # Cleanup the rules directory before filling it with the new rulest.
 522         &_cleanup_rulesdir();
 523
 524         # Load perl module to talk to the kernel syslog.
 525         use Sys::Syslog qw(:DEFAULT setlogsock);
 526
 527         # Establish the connection to the syslog service.
 528         openlog('oinkmaster', 'cons,pid', 'user');
 529
 530         # Call oinkmaster to generate ruleset.
 531         open(OINKMASTER, "/usr/local/bin/oinkmaster.pl -s -u file://$rulestarball -C $settingsdir/oinkmaster.conf -o $rulespath 2>&1 |") or die "Could not execute oinkmaster $!\n";
 532
 533         # Log output of oinkmaster to syslog.
 534         while(<OINKMASTER>) {
 535                 # The syslog function works best with an array based input,
 536                 # so generate one before passing the message details to syslog.
 537                 my @syslog = ("INFO", "$_");
 538
 539                 # Send the log message.
 540                 syslog(@syslog);
 541         }
 542
 543         # Close the pipe to oinkmaster process.
 544         close(OINKMASTER);
 545
 546         # Close the log handle.
 547         closelog();
 548 }
 549
 550 #
 551 ## Function to merge the classifications for a given amount of providers and write them
 552 ## to the classifications file.
 553 #
 554 sub merge_classifications(@) {
 555         my @providers = @_;
 556
 557         # Hash to store all collected classifications.
 558         my %classifications = ();
 559
 560         # Loop through the given array of providers.
 561         foreach my $provider (@providers) {
 562                 # Generate full path to classification file.
 563                 my $classification_file = "$tmp_conf_directory/$provider\-classification.config";
 564
 565                 # Skip provider if no classification file exists.
 566                 next unless (-f "$classification_file");
 567
 568                 # Open the classification file.
 569                 open(CLASSIFICATION, $classification_file) or die "Could not open file $classification_file. $!\n";
 570
 571                 # Loop through the file content.
 572                 while(<CLASSIFICATION>) {
 573                         # Parse the file and grab the classification details.
 574                         if ($_ =~/.*config classification\: (.*)/) {
 575                                 # Split the grabbed details.
 576                                 my ($short_name, $short_desc, $priority) = split("\,", $1);
 577
 578                                 # Check if the grabbed classification is allready known and the priority value is greater
 579                                 # than the stored one (which causes less priority in the IDS).
 580                                 if (($classifications{$short_name}) && ($classifications{$short_name}[1] >= $priority)) {
 581                                         #Change the priority value to the stricter one.
 582                                         $classifications{$short_name} = [ "$classifications{$short_name}[0]", "$priority" ];
 583                                 } else {
 584                                         # Add the classification to the hash.
 585                                         $classifications{$short_name} = [ "$short_desc", "$priority" ];
 586                                 }
 587                         }
 588                 }
 589
 590                 # Close the file.
 591                 close(CLASSIFICATION);
 592         }
 593
 594         # Open classification file for writing.
 595         open(FILE, ">", "$classification_file") or die "Could not write to $classification_file. $!\n";
 596
 597         # Print notice about autogenerated file.
 598         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n\n";
 599
 600         # Sort and loop through the hash of classifications.
 601         foreach my $key (sort keys %classifications) {
 602                 # Assign some nice variable names for the items.
 603                 my $short_name = $key;
 604                 my $short_desc = $classifications{$key}[0];
 605                 my $priority = $classifications{$key}[1];
 606
 607                 # Write the classification to the file.
 608                 print FILE "config classification: $short_name,$short_desc,$priority\n";
 609         }
 610
 611         # Close file handle.
 612         close(FILE);
 613 }
 614
 615 #
 616 ## Function to merge the "sid to message mapping" files of various given providers.
 617 #
 618 sub merge_sid_msg (@) {
 619         my @providers = @_;
 620
 621         # Hash which contains all the sid to message mappings.
 622         my %mappings = ();
 623
 624         # Loop through the array of given providers.
 625         foreach my $provider (@providers) {
 626                 # Generate full path and filename.
 627                 my $sid_msg_file = "$tmp_conf_directory/$provider\-sid-msg.map";
 628
 629                 # Skip provider if no sid to msg mapping file for this provider exists.
 630                 next unless (-f $sid_msg_file);
 631
 632                 # Open the file.
 633                 open(MAPPING, $sid_msg_file) or die "Could not open $sid_msg_file. $!\n";
 634
 635                 # Loop through the file content.
 636                 while (<MAPPING>) {
 637                         # Remove newlines.
 638                         chomp($_);
 639
 640                         # Skip lines which do not start with a number,
 641                         next unless ($_ =~ /^\d+/);
 642
 643                         # Split line content and assign it to an array.
 644                         my @line = split(/ \|\| /, $_);
 645
 646                         # Grab the first element (and remove it) from the line array.
 647                         # It contains the sid.
 648                         my $sid = shift(@line);
 649
 650                         # Store the grabbed sid and the remain array as hash value.
 651                         # It still contains the messages, references etc.
 652                         $mappings{$sid} = [@line];
 653                 }
 654
 655                 # Close file handle.
 656                 close(MAPPING);
 657         }
 658
 659         # Open mappings file for writing.
 660         open(FILE, ">", $sid_msg_file) or die "Could not write $sid_msg_file. $!\n";
 661
 662         # Write notice about autogenerated file.
 663         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n\n";
 664
 665         # Loop through the hash of mappings.
 666         foreach my $sid ( sort keys %mappings) {
 667                 # Grab data for the sid.
 668                 my @data = @{$mappings{$sid}};
 669
 670                 # Add the sid to the data array.
 671                 unshift(@data, $sid);
 672
 673                 # Generate line.
 674                 my $line = join(" \|\| ", @data);
 675
 676                 print FILE "$line\n";
 677
 678         }
 679
 680         # Close file handle.
 681         close(FILE);
 682 }
 683
 684 #
 685 ## Function to do all the logging stuff if the downloading or updating of the ruleset fails.
 686 #
 687 sub log_error ($) {
 688         my ($error) = @_;
 689
 690         # Remove any newline.
 691         chomp($error);
 692
 693         # Call private function to log the error message to syslog.
 694         &_log_to_syslog($error);
 695
 696         # Call private function to write/store the error message in the storederrorfile.
 697         &_store_error_message($error);
 698 }
 699
 700 #
 701 ## Function to log a given error message to the kernel syslog.
 702 #
 703 sub _log_to_syslog ($) {
 704         my ($message) = @_;
 705
 706         # Load perl module to talk to the kernel syslog.
 707         use Sys::Syslog qw(:DEFAULT setlogsock);
 708
 709         # The syslog function works best with an array based input,
 710         # so generate one before passing the message details to syslog.
 711         my @syslog = ("ERR", "<ERROR> $message");
 712
 713         # Establish the connection to the syslog service.
 714         openlog('oinkmaster', 'cons,pid', 'user');
 715
 716         # Send the log message.
 717         syslog(@syslog);
 718
 719         # Close the log handle.
 720         closelog();
 721 }
 722
 723 #
 724 ## Private function to write a given error message to the storederror file.
 725 #
 726 sub _store_error_message ($) {
 727         my ($message) = @_;
 728
 729         # Remove any newline.
 730         chomp($message);
 731
 732         # Open file for writing.
 733         open (ERRORFILE, ">$storederrorfile") or die "Could not write to $storederrorfile. $!\n";
 734
 735         # Write error to file.
 736         print ERRORFILE "$message\n";
 737
 738         # Close file.
 739         close (ERRORFILE);
 740
 741         # Set correct ownership for the file.
 742         &set_ownership("$storederrorfile");
 743 }
 744
 745 #
 746 ## Private function to get the path and filename for a downloaded ruleset by a given provider.
 747 #
 748 sub _get_dl_rulesfile($) {
 749         my ($provider) = @_;
 750
 751         # Gather the download type for the given provider.
 752         my $dl_type = $IDS::Ruleset::Providers{$provider}{'dl_type'};
 753
 754         # Obtain the file suffix for the download file type.
 755         my $suffix = $dl_type_to_suffix{$dl_type};
 756
 757         # Check if a suffix has been found.
 758         unless ($suffix) {
 759                 # Abort return - nothing.
 760                 return;
 761         }
 762
 763         # Generate the full filename and path for the stored rules file.
 764         my $rulesfile = "$dl_rules_path/$dl_rulesfile_prefix-$provider$suffix";
 765
 766         # Return the generated filename.
 767         return $rulesfile;
 768 }
 769
 770 #
 771 ## Function to check if the IDS is running.
 772 #
 773 sub ids_is_running () {
 774         if(-f $idspidfile) {
 775                 # Open PID file for reading.
 776                 open(PIDFILE, "$idspidfile") or die "Could not open $idspidfile. $!\n";
 777
 778                 # Grab the process-id.
 779                 my $pid = <PIDFILE>;
 780
 781                 # Close filehandle.
 782                 close(PIDFILE);
 783
 784                 # Remove any newline.
 785                 chomp($pid);
 786
 787                 # Check if a directory for the process-id exists in proc.
 788                 if(-d "/proc/$pid") {
 789                         # The IDS daemon is running return the process id.
 790                         return $pid;
 791                 }
 792         }
 793
 794         # Return nothing - IDS is not running.
 795         return;
 796 }
 797
 798 #
 799 ## Function to call suricatactrl binary with a given command.
 800 #
 801 sub call_suricatactrl ($) {
 802         # Get called option.
 803         my ($option, $interval) = @_;
 804
 805         # Loop through the array of supported commands and check if
 806         # the given one is part of it.
 807         foreach my $cmd (@suricatactrl_cmds) {
 808                 # Skip current command unless the given one has been found.
 809                 next unless($cmd eq $option);
 810
 811                 # Check if the given command is "cron".
 812                 if ($option eq "cron") {
 813                         # Check if an interval has been given.
 814                         if ($interval) {
 815                                 # Check if the given interval is valid.
 816                                 foreach my $element (@cron_intervals) {
 817                                         # Skip current element until the given one has been found.
 818                                         next unless($element eq $interval);
 819
 820                                         # Call the suricatactrl binary and pass the "cron" command
 821                                         # with the requrested interval.
 822                                         &General::system("$suricatactrl", "$option", "$interval");
 823
 824                                         # Return "1" - True.
 825                                         return 1;
 826                                 }
 827                         }
 828
 829                         # If we got here, the given interval is not supported or none has been given. - Return nothing.
 830                         return;
 831                 } else {
 832                         # Call the suricatactrl binary and pass the requrested
 833                         # option to it.
 834                         &General::system("$suricatactrl", "$option");
 835
 836                         # Return "1" - True.
 837                         return 1;
 838                 }
 839         }
 840
 841         # Command not found - return nothing.
 842         return;
 843 }
 844
 845 #
 846 ## Function to create a new empty file.
 847 #
 848 sub create_empty_file($) {
 849         my ($file) = @_;
 850
 851         # Check if the given file exists.
 852         if(-e $file) {
 853                 # Do nothing to prevent from overwriting existing files.
 854                 return;
 855         }
 856
 857         # Open the file for writing.
 858         open(FILE, ">$file") or die "Could not write to $file. $!\n";
 859
 860         # Close file handle.
 861         close(FILE);
 862
 863         # Return true.
 864         return 1;
 865 }
 866
 867 #
 868 ## Private function to check if the file permission of the rulespath are correct.
 869 ## If not, call suricatactrl to fix them.
 870 #
 871 sub _check_rulesdir_permissions() {
 872         # Check if the rulepath main directory is writable.
 873         unless (-W $rulespath) {
 874                 # If not call suricatctrl to fix it.
 875                 &call_suricatactrl("fix-rules-dir");
 876         }
 877
 878         # Open snort rules directory and do a directory listing.
 879         opendir(DIR, $rulespath) or die $!;
 880         # Loop through the direcory.
 881         while (my $file = readdir(DIR)) {
 882                 # We only want files.
 883                 next unless (-f "$rulespath/$file");
 884
 885                 # Check if the file is writable by the user.
 886                 if (-W "$rulespath/$file") {
 887                         # Everything is okay - go on to the next file.
 888                         next;
 889                 } else {
 890                         # There are wrong permissions, call suricatactrl to fix it.
 891                         &call_suricatactrl("fix-rules-dir");
 892                 }
 893         }
 894 }
 895
 896 #
 897 ## Private function to cleanup the directory which contains
 898 ## the IDS rules, before extracting and modifing the new ruleset.
 899 #
 900 sub _cleanup_rulesdir() {
 901         # Open rules directory and do a directory listing.
 902         opendir(DIR, $rulespath) or die $!;
 903
 904         # Loop through the direcory.
 905         while (my $file = readdir(DIR)) {
 906                 # We only want files.
 907                 next unless (-f "$rulespath/$file");
 908
 909                 # Skip element if it has config as file extension.
 910                 next if ($file =~ m/\.config$/);
 911
 912                 # Skip rules file for whitelisted hosts.
 913                 next if ("$rulespath/$file" eq $whitelist_file);
 914
 915                 # Skip rules file with local rules.
 916                 next if ("$rulespath/$file" eq $local_rules_file);
 917
 918                 # Delete the current processed file, if not, exit this function
 919                 # and return an error message.
 920                 unlink("$rulespath/$file") or return "Could not delete $rulespath/$file. $!\n";
 921         }
 922
 923         # Return nothing;
 924         return;
 925 }
 926
 927 #
 928 ## Function to generate the file which contains the home net information.
 929 #
 930 sub generate_home_net_file() {
 931         my %netsettings;
 932
 933         # Read-in network settings.
 934         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
 935
 936         # Get available network zones.
 937         my @network_zones = &Network::get_available_network_zones();
 938
 939         # Temporary array to store network address and prefix of the configured
 940         # networks.
 941         my @networks;
 942
 943         # Loop through the array of available network zones.
 944         foreach my $zone (@network_zones) {
 945                 # Check if the current processed zone is red.
 946                 if($zone eq "red") {
 947                         # Grab the IP-address of the red interface.
 948                         my $red_address = &get_red_address();
 949
 950                         # Check if an address has been obtained.
 951                         if ($red_address) {
 952                                 # Generate full network string.
 953                                 my $red_network = join("/", $red_address, "32");
 954
 955                                 # Add the red network to the array of networks.
 956                                 push(@networks, $red_network);
 957                         }
 958
 959                         # Check if the configured RED_TYPE is static.
 960                         if ($netsettings{'RED_TYPE'} eq "STATIC") {
 961                                 # Get configured and enabled aliases.
 962                                 my @aliases = &get_aliases();
 963
 964                                 # Loop through the array.
 965                                 foreach my $alias (@aliases) {
 966                                         # Add "/32" prefix.
 967                                         my $network = join("/", $alias, "32");
 968
 969                                         # Add the generated network to the array of networks.
 970                                         push(@networks, $network);
 971                                 }
 972                         }
 973                 # Process remaining network zones.
 974                 } else {
 975                         # Convert current zone name into upper case.
 976                         $zone = uc($zone);
 977
 978                         # Generate key to access the required data from the netsettings hash.
 979                         my $zone_netaddress = $zone . "_NETADDRESS";
 980                         my $zone_netmask = $zone . "_NETMASK";
 981
 982                         # Obtain the settings from the netsettings hash.
 983                         my $netaddress = $netsettings{$zone_netaddress};
 984                         my $netmask = $netsettings{$zone_netmask};
 985
 986                         # Convert the subnetmask into prefix notation.
 987                         my $prefix = &Network::convert_netmask2prefix($netmask);
 988
 989                         # Generate full network string.
 990                         my $network = join("/", $netaddress,$prefix);
 991
 992                         # Check if the network is valid.
 993                         if(&Network::check_subnet($network)) {
 994                                 # Add the generated network to the array of networks.
 995                                 push(@networks, $network);
 996                         }
 997                 }
 998         }
 999
1000         # Format home net declaration.
1001         my $line = "\"[" . join(',', @networks) . "]\"";
1002
1003         # Open file to store the addresses of the home net.
1004         open(FILE, ">$homenet_file") or die "Could not open $homenet_file. $!\n";
1005
1006         # Print yaml header.
1007         print FILE "%YAML 1.1\n";
1008         print FILE "---\n\n";
1009
1010         # Print notice about autogenerated file.
1011         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1012
1013         # Print the generated and required HOME_NET declaration to the file.
1014         print FILE "HOME_NET:\t$line\n";
1015
1016         # Close file handle.
1017         close(FILE);
1018 }
1019
1020 #
1021 # Function to generate and write the file which contains the configured and used DNS servers.
1022 #
1023 sub generate_dns_servers_file() {
1024         # Get the used DNS servers.
1025         my @nameservers = &General::get_nameservers();
1026
1027         # Get network settings.
1028         my %netsettings;
1029         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
1030
1031         # Format dns servers declaration.
1032         my $line = "";
1033
1034         # Check if the system has configured nameservers.
1035         if (@nameservers) {
1036                 # Add the GREEN address as DNS servers.
1037                 push(@nameservers, $netsettings{'GREEN_ADDRESS'});
1038
1039                 # Check if a BLUE zone exists.
1040                 if ($netsettings{'BLUE_ADDRESS'}) {
1041                         # Add the BLUE address to the array of nameservers.
1042                         push(@nameservers, $netsettings{'BLUE_ADDRESS'});
1043                 }
1044
1045                 # Generate the line which will be written to the DNS servers file.
1046                 $line = join(",", @nameservers);
1047         } else {
1048                 # External net simply contains (any).
1049                 $line = "\$EXTERNAL_NET";
1050         }
1051
1052         # Open file to store the used DNS server addresses.
1053         open(FILE, ">$dns_servers_file") or die "Could not open $dns_servers_file. $!\n";
1054
1055         # Print yaml header.
1056         print FILE "%YAML 1.1\n";
1057         print FILE "---\n\n";
1058
1059         # Print notice about autogenerated file.
1060         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1061
1062         # Print the generated DNS declaration to the file.
1063         print FILE "DNS_SERVERS:\t\"[$line]\"\n";
1064
1065         # Close file handle.
1066         close(FILE);
1067 }
1068
1069 #
1070 # Function to generate and write the file which contains the HTTP_PORTS definition.
1071 #
1072 sub generate_http_ports_file() {
1073         my %proxysettings;
1074
1075         # Read-in proxy settings
1076         &General::readhash("${General::swroot}/proxy/advanced/settings", \%proxysettings);
1077
1078         # Check if the proxy is enabled.
1079         if (( -e "${General::swroot}/proxy/enable") || (-e "${General::swroot}/proxy/enable_blue")) {
1080                 # Add the proxy port to the array of HTTP ports.
1081                 push(@http_ports, $proxysettings{'PROXY_PORT'});
1082         }
1083
1084         # Check if the transparent mode of the proxy is enabled.
1085         if ((-e "${General::swroot}/proxy/transparent") || (-e "${General::swroot}/proxy/transparent_blue")) {
1086                 # Add the transparent proxy port to the array of HTTP ports.
1087                 push(@http_ports, $proxysettings{'TRANSPARENT_PORT'});
1088         }
1089
1090         # Format HTTP_PORTS declaration.
1091         my $line = "";
1092
1093         # Generate line which will be written to the http ports file.
1094         $line = join(",", @http_ports);
1095
1096         # Open file to store the HTTP_PORTS.
1097         open(FILE, ">$http_ports_file") or die "Could not open $http_ports_file. $!\n";
1098
1099         # Print yaml header.
1100         print FILE "%YAML 1.1\n";
1101         print FILE "---\n\n";
1102
1103         # Print notice about autogenerated file.
1104         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1105
1106         # Print the generated HTTP_PORTS declaration to the file.
1107         print FILE "HTTP_PORTS:\t\"[$line]\"\n";
1108
1109         # Close file handle.
1110         close(FILE);
1111 }
1112
1113 #
1114 ## Function to generate and write the file for used rulefiles.
1115 #
1116 sub write_used_rulefiles_file(@) {
1117         my @files = @_;
1118
1119         # Open file for used rulefiles.
1120         open (FILE, ">$used_rulefiles_file") or die "Could not write to $used_rulefiles_file. $!\n";
1121
1122         # Write yaml header to the file.
1123         print FILE "%YAML 1.1\n";
1124         print FILE "---\n\n";
1125
1126         # Write header to file.
1127         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1128
1129         # Allways use the whitelist.
1130         print FILE " - whitelist.rules\n";
1131
1132         # Loop through the array of given files.
1133         foreach my $file (@files) {
1134                 # Check if the given filename exists and write it to the file of used rulefiles.
1135                 if(-f "$rulespath/$file") {
1136                         print FILE " - $file\n";
1137                 }
1138         }
1139
1140         # Close file after writing.
1141         close(FILE);
1142 }
1143
1144 #
1145 ## Function to generate and write the file for modify the ruleset.
1146 #
1147 sub write_modify_sids_file() {
1148         # Get configured settings.
1149         my %idssettings=();
1150         my %rulessettings=();
1151         &General::readhash("$ids_settings_file", \%idssettings);
1152         &General::readhash("$rules_settings_file", \%rulessettings);
1153
1154         # Gather the configured ruleset.
1155         my $ruleset = $rulessettings{'RULES'};
1156
1157         # Open modify sid's file for writing.
1158         open(FILE, ">$modify_sids_file") or die "Could not write to $modify_sids_file. $!\n";
1159
1160         # Write file header.
1161         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1162
1163         # Check if the traffic only should be monitored.
1164         unless($idssettings{'MONITOR_TRAFFIC_ONLY'} eq 'on') {
1165                 # Suricata is in IPS mode, which means that the rule actions have to be changed
1166                 # from 'alert' to 'drop', however not all rules should be changed.  Some rules
1167                 # exist purely to set a flowbit which is used to convey other information, such
1168                 # as a specific type of file being downloaded, to other rulewhich then check for
1169                 # malware in that file.  Rules which fall into the first category should stay as
1170                 # alert since not all flows of that type contain malware.
1171
1172                 if($ruleset eq 'registered' or $ruleset eq 'subscripted' or $ruleset eq 'community') {
1173                         # These types of rulesfiles contain meta-data which gives the action that should
1174                         # be used when in IPS mode.  Do the following:
1175                         #
1176                         # 1. Disable all rules and set the action to 'drop'
1177                         # 2. Set the action back to 'alert' if the rule contains 'flowbits:noalert;'
1178                         #    This should give rules not in the policy a reasonable default if the user
1179                         #    manually enables them.
1180                         # 3. Enable rules and set actions according to the meta-data strings.
1181
1182                         my $policy = 'balanced';  # Placeholder to allow policy to be changed.
1183
1184                         print FILE <<END;
1185 modifysid * "^#?(?:alert|drop)" | "#drop"
1186 modifysid * "^#drop(.+flowbits:noalert;)" | "#alert\${1}"
1187 modifysid * "^#(?:alert|drop)(.+policy $policy-ips alert)" | "alert\${1}"
1188 modifysid * "^#(?:alert|drop)(.+policy $policy-ips drop)" | "drop\${1}"
1189 END
1190                 } else {
1191                         # These rulefiles don't have the metadata, so set rules to 'drop' unless they
1192                         # contain the string 'flowbits:noalert;'.
1193                         print FILE <<END;
1194 modifysid * "^(#?)(?:alert|drop)" | "\${1}drop"
1195 modifysid * "^(#?)drop(.+flowbits:noalert;)" | "\${1}alert\${2}"
1196 END
1197                 }
1198         }
1199
1200         # Close file handle.
1201         close(FILE);
1202 }
1203
1204 #
1205 ## Function to gather the version of suricata.
1206 #
1207 sub get_suricata_version($) {
1208         my ($format) = @_;
1209
1210         # Execute piped suricata command and return the version information.
1211         open(SURICATA, "suricata -V |") or die "Couldn't execute program: $!";
1212
1213         # Grab and store the output of the piped program.
1214         my $version_string = <SURICATA>;
1215
1216         # Close pipe.
1217         close(SURICATA);
1218
1219         # Remove newlines.
1220         chomp($version_string);
1221
1222         # Grab the version from the version string.
1223         $version_string =~ /([0-9]+([.][0-9]+)+)/;
1224
1225         # Splitt the version into single chunks.
1226         my ($major_ver, $minor_ver, $patchlevel) = split(/\./, $1);
1227
1228         # Check and return the requested version sheme.
1229         if ($format eq "major") {
1230                 # Return the full version.
1231                 return "$major_ver";
1232         } elsif ($format eq "minor") {
1233                 # Return the major and minor part.
1234                 return "$major_ver.$minor_ver";
1235         } else {
1236                 # Return the full version string.
1237                 return "$major_ver.$minor_ver.$patchlevel";
1238         }
1239 }
1240
1241 #
1242 ## Function to generate the rules file with whitelisted addresses.
1243 #
1244 sub generate_ignore_file() {
1245         my %ignored = ();
1246
1247         # SID range 1000000-1999999 Reserved for Local Use
1248         # Put your custom rules in this range to avoid conflicts
1249         my $sid = 1500000;
1250
1251         # Read-in ignoredfile.
1252         &General::readhasharray($IDS::ignored_file, \%ignored);
1253
1254         # Open ignorefile for writing.
1255         open(FILE, ">$IDS::whitelist_file") or die "Could not write to $IDS::whitelist_file. $!\n";
1256
1257         # Config file header.
1258         print FILE "# Autogenerated file.\n";
1259         print FILE "# All user modifications will be overwritten.\n\n";
1260
1261         # Add all user defined addresses to the whitelist.
1262         #
1263         # Check if the hash contains any elements.
1264         if (keys (%ignored)) {
1265                 # Loop through the entire hash and write the host/network
1266                 # and remark to the ignore file.
1267                 while ( (my $key) = each %ignored) {
1268                         my $address = $ignored{$key}[0];
1269                         my $remark = $ignored{$key}[1];
1270                         my $status = $ignored{$key}[2];
1271
1272                         # Check if the status of the entry is "enabled".
1273                         if ($status eq "enabled") {
1274                                 # Check if the address/network is valid.
1275                                 if ((&General::validip($address)) || (&General::validipandmask($address))) {
1276                                         # Write rule line to the file to pass any traffic from this IP
1277                                         print FILE "pass ip $address any -> any any (msg:\"pass all traffic from/to $address\"\; sid:$sid\;)\n";
1278
1279                                         # Increment sid.
1280                                         $sid++;
1281                                 }
1282                         }
1283                 }
1284         }
1285
1286         close(FILE);
1287 }
1288
1289 #
1290 ## Function to set correct ownership for single files and directories.
1291 #
1292
1293 sub set_ownership($) {
1294         my ($target) = @_;
1295
1296         # User and group of the WUI.
1297         my $uname = "nobody";
1298         my $grname = "nobody";
1299
1300         # The chown function implemented in perl requies the user and group as nummeric id's.
1301         my $uid = getpwnam($uname);
1302         my $gid = getgrnam($grname);
1303
1304         # Check if the given target exists.
1305         unless ($target) {
1306                 # Stop the script and print error message.
1307                 die "The $target does not exist. Cannot change the ownership!\n";
1308         }
1309
1310         # Check weather the target is a file or directory.
1311         if (-f $target) {
1312                 # Change ownership ot the single file.
1313                 chown($uid, $gid, "$target");
1314         } elsif (-d $target) {
1315                 # Do a directory listing.
1316                 opendir(DIR, $target) or die $!;
1317                         # Loop through the direcory.
1318                         while (my $file = readdir(DIR)) {
1319
1320                                 # We only want files.
1321                                 next unless (-f "$target/$file");
1322
1323                                 # Set correct ownership for the files.
1324                                 chown($uid, $gid, "$target/$file");
1325                         }
1326
1327                 closedir(DIR);
1328
1329                 # Change ownership of the directory.
1330                 chown($uid, $gid, "$target");
1331         }
1332 }
1333
1334 #
1335 ## Function to read-in the aliases file and returns all configured and enabled aliases.
1336 #
1337 sub get_aliases() {
1338         # Location of the aliases file.
1339         my $aliases_file = "${General::swroot}/ethernet/aliases";
1340
1341         # Array to store the aliases.
1342         my @aliases;
1343
1344         # Check if the file is empty.
1345         if (-z $aliases_file) {
1346                 # Abort nothing to do.
1347                 return;
1348         }
1349
1350         # Open the aliases file.
1351         open(ALIASES, $aliases_file) or die "Could not open $aliases_file. $!\n";
1352
1353         # Loop through the file content.
1354         while (my $line = <ALIASES>) {
1355                 # Remove newlines.
1356                 chomp($line);
1357
1358                 # Splitt line content into single chunks.
1359                 my ($address, $state, $remark) = split(/\,/, $line);
1360
1361                 # Check if the state of the current processed alias is "on".
1362                 if ($state eq "on") {
1363                         # Check if the address is valid.
1364                         if(&Network::check_ip_address($address)) {
1365                                 # Add the alias to the array of aliases.
1366                                 push(@aliases, $address);
1367                         }
1368                 }
1369         }
1370
1371         # Close file handle.
1372         close(ALIASES);
1373
1374         # Return the array.
1375         return @aliases;
1376 }
1377
1378 #
1379 ## Function to grab the current assigned IP-address on red.
1380 #
1381 sub get_red_address() {
1382         # File, which contains the current IP-address of the red interface.
1383         my $file = "${General::swroot}/red/local-ipaddress";
1384
1385         # Check if the file exists.
1386         if (-e $file) {
1387                 # Open the given file.
1388                 open(FILE, "$file") or die "Could not open $file.";
1389
1390                 # Obtain the address from the first line of the file.
1391                 my $address = <FILE>;
1392
1393                 # Close filehandle
1394                 close(FILE);
1395
1396                 # Remove newlines.
1397                 chomp $address;
1398
1399                 # Check if the grabbed address is valid.
1400                 if (&General::validip($address)) {
1401                         # Return the address.
1402                         return $address;
1403                 }
1404         }
1405
1406         # Return nothing.
1407         return;
1408 }
1409
1410 #
1411 ## Function to write the lock file for locking the WUI, while
1412 ## the autoupdate script runs.
1413 #
1414 sub lock_ids_page() {
1415         # Call subfunction to create the file.
1416         &create_empty_file($ids_page_lock_file);
1417 }
1418
1419 #
1420 ## Function to release the lock of the WUI, again.
1421 #
1422 sub unlock_ids_page() {
1423         # Delete lock file.
1424         unlink($ids_page_lock_file);
1425 }
1426
1427 1;