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