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 package IDS;
  25
  26 require '/var/ipfire/general-functions.pl';
  27
  28 # Location where all config and settings files are stored.
  29 our $settingsdir = "${General::swroot}/suricata";
  30
  31 # File where the used rulefiles are stored.
  32 our $used_rulefiles_file = "$settingsdir/suricata-used-rulefiles.yaml";
  33
  34 # File where the addresses of the homenet are stored.
  35 our $homenet_file = "$settingsdir/suricata-homenet.yaml";
  36
  37 # File where the addresses of the used DNS servers are stored.
  38 our $dns_servers_file = "$settingsdir/suricata-dns-servers.yaml";
  39
  40 # File where the HTTP ports definition is stored.
  41 our $http_ports_file = "$settingsdir/suricata-http-ports.yaml";
  42
  43 # File which contains the enabled sids.
  44 our $enabled_sids_file = "$settingsdir/oinkmaster-enabled-sids.conf";
  45
  46 # File which contains the disabled sids.
  47 our $disabled_sids_file = "$settingsdir/oinkmaster-disabled-sids.conf";
  48
  49 # File which contains wheater the rules should be changed.
  50 our $modify_sids_file = "$settingsdir/oinkmaster-modify-sids.conf";
  51
  52 # File which stores the configured IPS settings.
  53 our $ids_settings_file = "$settingsdir/settings";
  54
  55 # File which stores the configured rules-settings.
  56 our $rules_settings_file = "$settingsdir/rules-settings";
  57
  58 # File which stores the configured settings for whitelisted addresses.
  59 our $ignored_file = "$settingsdir/ignored";
  60
  61 # Location and name of the tarball which contains the ruleset.
  62 our $rulestarball = "/var/tmp/idsrules.tar.gz";
  63
  64 # File to store any errors, which also will be read and displayed by the wui.
  65 our $storederrorfile = "/tmp/ids_storederror";
  66
  67 # File to lock the WUI, while the autoupdate script runs.
  68 our $ids_page_lock_file = "/tmp/ids_page_locked";
  69
  70 # Location where the rulefiles are stored.
  71 our $rulespath = "/var/lib/suricata";
  72
  73 # Location to store local rules. This file will not be touched.
  74 our $local_rules_file = "$rulespath/local.rules";
  75
  76 # File which contains the rules to whitelist addresses on suricata.
  77 our $whitelist_file = "$rulespath/whitelist.rules";
  78
  79 # File which contains a list of all supported ruleset sources.
  80 # (Sourcefire, Emergingthreads, etc..)
  81 our $rulesetsourcesfile = "$settingsdir/ruleset-sources";
  82
  83 # The pidfile of the IDS.
  84 our $idspidfile = "/var/run/suricata.pid";
  85
  86 # Location of suricatactrl.
  87 my $suricatactrl = "/usr/local/bin/suricatactrl";
  88
  89 # Array with allowed commands of suricatactrl.
  90 my @suricatactrl_cmds = ( 'start', 'stop', 'restart', 'reload', 'fix-rules-dir', 'cron' );
  91
  92 # Array with supported cron intervals.
  93 my @cron_intervals = ('off', 'daily', 'weekly' );
  94
  95 # Array which contains the HTTP ports, which statically will be declared as HTTP_PORTS in the
  96 # http_ports_file.
  97 my @http_ports = ('80', '81');
  98
  99 #
 100 ## Function to check and create all IDS related files, if the does not exist.
 101 #
 102 sub check_and_create_filelayout() {
 103         # Check if the files exist and if not, create them.
 104         unless (-f "$enabled_sids_file") { &create_empty_file($enabled_sids_file); }
 105         unless (-f "$disabled_sids_file") { &create_empty_file($disabled_sids_file); }
 106         unless (-f "$modify_sids_file") { &create_empty_file($modify_sids_file); }
 107         unless (-f "$used_rulefiles_file") { &create_empty_file($used_rulefiles_file); }
 108         unless (-f "$ids_settings_file") { &create_empty_file($ids_settings_file); }
 109         unless (-f "$rules_settings_file") { &create_empty_file($rules_settings_file); }
 110         unless (-f "$ignored_file") { &create_empty_file($ignored_file); }
 111         unless (-f "$whitelist_file" ) { &create_empty_file($whitelist_file); }
 112 }
 113
 114 #
 115 ## Function for checking if at least 300MB of free disk space are available
 116 ## on the "/var" partition.
 117 #
 118 sub checkdiskspace () {
 119         # Call diskfree to gather the free disk space of /var.
 120         my @df = `/bin/df -B M /var`;
 121
 122         # Loop through the output.
 123         foreach my $line (@df) {
 124                 # Ignore header line.
 125                 next if $line =~ m/^Filesystem/;
 126
 127                 # Search for a line with the device information.
 128                 if ($line =~ m/dev/ ) {
 129                         # Split the line into single pieces.
 130                         my @values = split(' ', $line);
 131                         my ($filesystem, $blocks, $used, $available, $used_perenctage, $mounted_on) = @values;
 132
 133                         # Check if the available disk space is more than 300MB.
 134                         if ($available < 300) {
 135                                 # Log error to syslog.
 136                                 &_log_to_syslog("Not enough free disk space on /var. Only $available MB from 300 MB available.");
 137
 138                                 # Exit function and return "1" - False.
 139                                 return 1;
 140                         }
 141                 }
 142         }
 143
 144         # Everything okay, return nothing.
 145         return;
 146 }
 147
 148 #
 149 ## This function is responsible for downloading the configured IDS ruleset.
 150 ##
 151 ## * At first it obtains from the stored rules settings which ruleset should be downloaded.
 152 ## * The next step is to get the download locations for all available rulesets.
 153 ## * After that, the function will check if an upstream proxy should be used and grab the settings.
 154 ## * The last step will be to generate the final download url, by obtaining the URL for the desired
 155 ##   ruleset, add the settings for the upstream proxy and final grab the rules tarball from the server.
 156 #
 157 sub downloadruleset {
 158         # Get rules settings.
 159         my %rulessettings=();
 160         &General::readhash("$rules_settings_file", \%rulessettings);
 161
 162         # Check if a ruleset has been configured.
 163         unless($rulessettings{'RULES'}) {
 164                 # Log that no ruleset has been configured and abort.
 165                 &_log_to_syslog("No ruleset source has been configured.");
 166
 167                 # Return "1".
 168                 return 1;
 169         }
 170
 171         # Get all available ruleset locations.
 172         my %rulesetsources=();
 173         &General::readhash($rulesetsourcesfile, \%rulesetsources);
 174
 175         # Read proxysettings.
 176         my %proxysettings=();
 177         &General::readhash("${General::swroot}/proxy/settings", \%proxysettings);
 178
 179         # Load required perl module to handle the download.
 180         use LWP::UserAgent;
 181
 182         # Init the download module.
 183         my $downloader = LWP::UserAgent->new;
 184
 185         # Set timeout to 10 seconds.
 186         $downloader->timeout(10);
 187
 188         # Check if an upstream proxy is configured.
 189         if ($proxysettings{'UPSTREAM_PROXY'}) {
 190                 my $proxy_url;
 191
 192                 $proxy_url = "http://";
 193
 194                 # Check if the proxy requires authentication.
 195                 if (($proxysettings{'UPSTREAM_USER'}) && ($proxysettings{'UPSTREAM_PASSWORD'})) {
 196                         $proxy_url .= "$proxysettings{'UPSTREAM_USER'}\:$proxysettings{'UPSTREAM_PASSWORD'}\@";
 197                 }
 198
 199                 # Add proxy server address and port.
 200                 $proxy_url .= $proxysettings{'UPSTREAM_PROXY'};
 201
 202                 # Setup proxy settings.
 203                 $downloader->proxy(['http', 'https'], $proxy_url);
 204         }
 205
 206         # Grab the right url based on the configured vendor.
 207         my $url = $rulesetsources{$rulessettings{'RULES'}};
 208
 209         # Check if the vendor requires an oinkcode and add it if needed.
 210         $url =~ s/\<oinkcode\>/$rulessettings{'OINKCODE'}/g;
 211
 212         # Abort if no url could be determined for the vendor.
 213         unless ($url) {
 214                 # Log error and abort.
 215                 &_log_to_syslog("Unable to gather a download URL for the selected ruleset.");
 216                 return 1;
 217         }
 218
 219         # Variable to store the filesize of the remote object.
 220         my $remote_filesize;
 221
 222         # The sourcfire (snort rules) does not allow to send "HEAD" requests, so skip this check
 223         # for this webserver.
 224         #
 225         # Check if the ruleset source contains "snort.org".
 226         unless ($url =~ /\.snort\.org/) {
 227                 # Pass the requrested url to the downloader.
 228                 my $request = HTTP::Request->new(HEAD => $url);
 229
 230                 # Accept the html header.
 231                 $request->header('Accept' => 'text/html');
 232
 233                 # Perform the request and fetch the html header.
 234                 my $response = $downloader->request($request);
 235
 236                 # Check if there was any error.
 237                 unless ($response->is_success) {
 238                         # Obtain error.
 239                         my $error = $response->status_line();
 240
 241                         # Log error message.
 242                         &_log_to_syslog("Unable to download the ruleset. \($error\)");
 243
 244                         # Return "1" - false.
 245                         return 1;
 246                 }
 247
 248                 # Assign the fetched header object.
 249                 my $header = $response->headers();
 250
 251                 # Grab the remote file size from the object and store it in the
 252                 # variable.
 253                 $remote_filesize = $header->content_length;
 254         }
 255
 256         # Load perl module to deal with temporary files.
 257         use File::Temp;
 258
 259         # Generate temporary file name, located in "/var/tmp" and with a suffix of ".tar.gz".
 260         my $tmp = File::Temp->new( SUFFIX => ".tar.gz", DIR => "/var/tmp/", UNLINK => 0 );
 261         my $tmpfile = $tmp->filename();
 262
 263         # Pass the requested url to the downloader.
 264         my $request = HTTP::Request->new(GET => $url);
 265
 266         # Perform the request and save the output into the tmpfile.
 267         my $response = $downloader->request($request, $tmpfile);
 268
 269         # Check if there was any error.
 270         unless ($response->is_success) {
 271                 # Obtain error.
 272                 my $error = $response->content;
 273
 274                 # Log error message.
 275                 &_log_to_syslog("Unable to download the ruleset. \($error\)");
 276
 277                 # Return "1" - false.
 278                 return 1;
 279         }
 280
 281         # Load perl stat module.
 282         use File::stat;
 283
 284         # Perform stat on the tmpfile.
 285         my $stat = stat($tmpfile);
 286
 287         # Grab the local filesize of the downloaded tarball.
 288         my $local_filesize = $stat->size;
 289
 290         # Check if both file sizes match.
 291         if (($remote_filesize) && ($remote_filesize ne $local_filesize)) {
 292                 # Log error message.
 293                 &_log_to_syslog("Unable to completely download the ruleset. ");
 294                 &_log_to_syslog("Only got $local_filesize Bytes instead of $remote_filesize Bytes. ");
 295
 296                 # Delete temporary file.
 297                 unlink("$tmpfile");
 298
 299                 # Return "1" - false.
 300                 return 1;
 301         }
 302
 303         # Load file copy module, which contains the move() function.
 304         use File::Copy;
 305
 306         # Overwrite existing rules tarball with the new downloaded one.
 307         move("$tmpfile", "$rulestarball");
 308
 309         # Set correct ownership for the rulesdir and files.
 310         set_ownership("$rulestarball");
 311
 312         # If we got here, everything worked fine. Return nothing.
 313         return;
 314 }
 315
 316 #
 317 ## A tiny wrapper function to call the oinkmaster script.
 318 #
 319 sub oinkmaster () {
 320         # Check if the files in rulesdir have the correct permissions.
 321         &_check_rulesdir_permissions();
 322
 323         # Cleanup the rules directory before filling it with the new rulest.
 324         &_cleanup_rulesdir();
 325
 326         # Load perl module to talk to the kernel syslog.
 327         use Sys::Syslog qw(:DEFAULT setlogsock);
 328
 329         # Establish the connection to the syslog service.
 330         openlog('oinkmaster', 'cons,pid', 'user');
 331
 332         # Call oinkmaster to generate ruleset.
 333         open(OINKMASTER, "/usr/local/bin/oinkmaster.pl -s -u file://$rulestarball -C $settingsdir/oinkmaster.conf -o $rulespath 2>&1 |") or die "Could not execute oinkmaster $!\n";
 334
 335         # Log output of oinkmaster to syslog.
 336         while(<OINKMASTER>) {
 337                 # The syslog function works best with an array based input,
 338                 # so generate one before passing the message details to syslog.
 339                 my @syslog = ("INFO", "$_");
 340
 341                 # Send the log message.
 342                 syslog(@syslog);
 343         }
 344
 345         # Close the pipe to oinkmaster process.
 346         close(OINKMASTER);
 347
 348         # Close the log handle.
 349         closelog();
 350 }
 351
 352 #
 353 ## Function to do all the logging stuff if the downloading or updating of the ruleset fails.
 354 #
 355 sub log_error ($) {
 356         my ($error) = @_;
 357
 358         # Remove any newline.
 359         chomp($error);
 360
 361         # Call private function to log the error message to syslog.
 362         &_log_to_syslog($error);
 363
 364         # Call private function to write/store the error message in the storederrorfile.
 365         &_store_error_message($error);
 366 }
 367
 368 #
 369 ## Function to log a given error message to the kernel syslog.
 370 #
 371 sub _log_to_syslog ($) {
 372         my ($message) = @_;
 373
 374         # Load perl module to talk to the kernel syslog.
 375         use Sys::Syslog qw(:DEFAULT setlogsock);
 376
 377         # The syslog function works best with an array based input,
 378         # so generate one before passing the message details to syslog.
 379         my @syslog = ("ERR", "<ERROR> $message");
 380
 381         # Establish the connection to the syslog service.
 382         openlog('oinkmaster', 'cons,pid', 'user');
 383
 384         # Send the log message.
 385         syslog(@syslog);
 386
 387         # Close the log handle.
 388         closelog();
 389 }
 390
 391 #
 392 ## Private function to write a given error message to the storederror file.
 393 #
 394 sub _store_error_message ($) {
 395         my ($message) = @_;
 396
 397         # Remove any newline.
 398         chomp($message);
 399
 400         # Open file for writing.
 401         open (ERRORFILE, ">$storederrorfile") or die "Could not write to $storederrorfile. $!\n";
 402
 403         # Write error to file.
 404         print ERRORFILE "$message\n";
 405
 406         # Close file.
 407         close (ERRORFILE);
 408
 409         # Set correct ownership for the file.
 410         &set_ownership("$storederrorfile");
 411 }
 412
 413 #
 414 ## Function to get a list of all available network zones.
 415 #
 416 sub get_available_network_zones () {
 417         # Get netsettings.
 418         my %netsettings = ();
 419         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
 420
 421         # Obtain the configuration type from the netsettings hash.
 422         my $config_type = $netsettings{'CONFIG_TYPE'};
 423
 424         # Hash which contains the conversation from the config mode
 425         # to the existing network interface names. They are stored like
 426         # an array.
 427         #
 428         # Mode "0" red is a modem and green
 429         # Mode "1" red is a netdev and green
 430         # Mode "2" red, green and orange
 431         # Mode "3" red, green and blue
 432         # Mode "4" red, green, blue, orange
 433         my %config_type_to_interfaces = (
 434                 "0" => [ "red", "green" ],
 435                 "1" => [ "red", "green" ],
 436                 "2" => [ "red", "green", "orange" ],
 437                 "3" => [ "red", "green", "blue" ],
 438                 "4" => [ "red", "green", "blue", "orange" ]
 439         );
 440
 441         # Obtain and dereference the corresponding network interaces based on the read
 442         # network config type.
 443         my @network_zones = @{ $config_type_to_interfaces{$config_type} };
 444
 445         # Return them.
 446         return @network_zones;
 447 }
 448
 449 #
 450 ## Function to check if the IDS is running.
 451 #
 452 sub ids_is_running () {
 453         if(-f $idspidfile) {
 454                 # Open PID file for reading.
 455                 open(PIDFILE, "$idspidfile") or die "Could not open $idspidfile. $!\n";
 456
 457                 # Grab the process-id.
 458                 my $pid = <PIDFILE>;
 459
 460                 # Close filehandle.
 461                 close(PIDFILE);
 462
 463                 # Remove any newline.
 464                 chomp($pid);
 465
 466                 # Check if a directory for the process-id exists in proc.
 467                 if(-d "/proc/$pid") {
 468                         # The IDS daemon is running return the process id.
 469                         return $pid;
 470                 }
 471         }
 472
 473         # Return nothing - IDS is not running.
 474         return;
 475 }
 476
 477 #
 478 ## Function to call suricatactrl binary with a given command.
 479 #
 480 sub call_suricatactrl ($) {
 481         # Get called option.
 482         my ($option, $interval) = @_;
 483
 484         # Loop through the array of supported commands and check if
 485         # the given one is part of it.
 486         foreach my $cmd (@suricatactrl_cmds) {
 487                 # Skip current command unless the given one has been found.
 488                 next unless($cmd eq $option);
 489
 490                 # Check if the given command is "cron".
 491                 if ($option eq "cron") {
 492                         # Check if an interval has been given.
 493                         if ($interval) {
 494                                 # Check if the given interval is valid.
 495                                 foreach my $element (@cron_intervals) {
 496                                         # Skip current element until the given one has been found.
 497                                         next unless($element eq $interval);
 498
 499                                         # Call the suricatactrl binary and pass the "cron" command
 500                                         # with the requrested interval.
 501                                         system("$suricatactrl $option $interval &>/dev/null");
 502
 503                                         # Return "1" - True.
 504                                         return 1;
 505                                 }
 506                         }
 507
 508                         # If we got here, the given interval is not supported or none has been given. - Return nothing.
 509                         return;
 510                 } else {
 511                         # Call the suricatactrl binary and pass the requrested
 512                         # option to it.
 513                         system("$suricatactrl $option &>/dev/null");
 514
 515                         # Return "1" - True.
 516                         return 1;
 517                 }
 518         }
 519
 520         # Command not found - return nothing.
 521         return;
 522 }
 523
 524 #
 525 ## Function to create a new empty file.
 526 #
 527 sub create_empty_file($) {
 528         my ($file) = @_;
 529
 530         # Check if the given file exists.
 531         if(-e $file) {
 532                 # Do nothing to prevent from overwriting existing files.
 533                 return;
 534         }
 535
 536         # Open the file for writing.
 537         open(FILE, ">$file") or die "Could not write to $file. $!\n";
 538
 539         # Close file handle.
 540         close(FILE);
 541
 542         # Return true.
 543         return 1;
 544 }
 545
 546 #
 547 ## Private function to check if the file permission of the rulespath are correct.
 548 ## If not, call suricatactrl to fix them.
 549 #
 550 sub _check_rulesdir_permissions() {
 551         # Check if the rulepath main directory is writable.
 552         unless (-W $rulespath) {
 553                 # If not call suricatctrl to fix it.
 554                 &call_suricatactrl("fix-rules-dir");
 555         }
 556
 557         # Open snort rules directory and do a directory listing.
 558         opendir(DIR, $rulespath) or die $!;
 559         # Loop through the direcory.
 560         while (my $file = readdir(DIR)) {
 561                 # We only want files.
 562                 next unless (-f "$rulespath/$file");
 563
 564                 # Check if the file is writable by the user.
 565                 if (-W "$rulespath/$file") {
 566                         # Everything is okay - go on to the next file.
 567                         next;
 568                 } else {
 569                         # There are wrong permissions, call suricatactrl to fix it.
 570                         &call_suricatactrl("fix-rules-dir");
 571                 }
 572         }
 573 }
 574
 575 #
 576 ## Private function to cleanup the directory which contains
 577 ## the IDS rules, before extracting and modifing the new ruleset.
 578 #
 579 sub _cleanup_rulesdir() {
 580         # Open rules directory and do a directory listing.
 581         opendir(DIR, $rulespath) or die $!;
 582
 583         # Loop through the direcory.
 584         while (my $file = readdir(DIR)) {
 585                 # We only want files.
 586                 next unless (-f "$rulespath/$file");
 587
 588                 # Skip element if it has config as file extension.
 589                 next if ($file =~ m/\.config$/);
 590
 591                 # Skip rules file for whitelisted hosts.
 592                 next if ("$rulespath/$file" eq $whitelist_file);
 593
 594                 # Skip rules file with local rules.
 595                 next if ("$rulespath/$file" eq $local_rules_file);
 596
 597                 # Delete the current processed file, if not, exit this function
 598                 # and return an error message.
 599                 unlink("$rulespath/$file") or return "Could not delete $rulespath/$file. $!\n";
 600         }
 601
 602         # Return nothing;
 603         return;
 604 }
 605
 606 #
 607 ## Function to generate the file which contains the home net information.
 608 #
 609 sub generate_home_net_file() {
 610         my %netsettings;
 611
 612         # Read-in network settings.
 613         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
 614
 615         # Get available network zones.
 616         my @network_zones = &get_available_network_zones();
 617
 618         # Temporary array to store network address and prefix of the configured
 619         # networks.
 620         my @networks;
 621
 622         # Loop through the array of available network zones.
 623         foreach my $zone (@network_zones) {
 624                 # Check if the current processed zone is red.
 625                 if($zone eq "red") {
 626                         # Grab the IP-address of the red interface.
 627                         my $red_address = &get_red_address();
 628
 629                         # Check if an address has been obtained.
 630                         if ($red_address) {
 631                                 # Generate full network string.
 632                                 my $red_network = join("/", $red_address, "32");
 633
 634                                 # Add the red network to the array of networks.
 635                                 push(@networks, $red_network);
 636                         }
 637
 638                         # Check if the configured RED_TYPE is static.
 639                         if ($netsettings{'RED_TYPE'} eq "STATIC") {
 640                                 # Get configured and enabled aliases.
 641                                 my @aliases = &get_aliases();
 642
 643                                 # Loop through the array.
 644                                 foreach my $alias (@aliases) {
 645                                         # Add "/32" prefix.
 646                                         my $network = join("/", $alias, "32");
 647
 648                                         # Add the generated network to the array of networks.
 649                                         push(@networks, $network);
 650                                 }
 651                         }
 652                 # Process remaining network zones.
 653                 } else {
 654                         # Convert current zone name into upper case.
 655                         $zone = uc($zone);
 656
 657                         # Generate key to access the required data from the netsettings hash.
 658                         my $zone_netaddress = $zone . "_NETADDRESS";
 659                         my $zone_netmask = $zone . "_NETMASK";
 660
 661                         # Obtain the settings from the netsettings hash.
 662                         my $netaddress = $netsettings{$zone_netaddress};
 663                         my $netmask = $netsettings{$zone_netmask};
 664
 665                         # Convert the subnetmask into prefix notation.
 666                         my $prefix = &Network::convert_netmask2prefix($netmask);
 667
 668                         # Generate full network string.
 669                         my $network = join("/", $netaddress,$prefix);
 670
 671                         # Check if the network is valid.
 672                         if(&Network::check_subnet($network)) {
 673                                 # Add the generated network to the array of networks.
 674                                 push(@networks, $network);
 675                         }
 676                 }
 677         }
 678
 679         # Format home net declaration.
 680         my $line = "\"\[";
 681
 682         # Loop through the array of networks.
 683         foreach my $network (@networks) {
 684                 # Add the network to the line.
 685                 $line = "$line" . "$network";
 686
 687                 # Check if the current network was the last in the array.
 688                 if ($network eq $networks[-1]) {
 689                         # Close the line.
 690                         $line = "$line" . "\]\"";
 691                 } else {
 692                         # Add "," for the next network.
 693                         $line = "$line" . "\,";
 694                 }
 695         }
 696
 697         # Open file to store the addresses of the home net.
 698         open(FILE, ">$homenet_file") or die "Could not open $homenet_file. $!\n";
 699
 700         # Print yaml header.
 701         print FILE "%YAML 1.1\n";
 702         print FILE "---\n\n";
 703
 704         # Print notice about autogenerated file.
 705         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
 706
 707         # Print the generated and required HOME_NET declaration to the file.
 708         print FILE "HOME_NET:\t$line\n";
 709
 710         # Close file handle.
 711         close(FILE);
 712 }
 713
 714 #
 715 # Function to generate and write the file which contains the configured and used DNS servers.
 716 #
 717 sub generate_dns_servers_file() {
 718         # Get the used DNS servers.
 719         my @nameservers = &General::get_nameservers();
 720
 721         # Get network settings.
 722         my %netsettings;
 723         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
 724
 725         # Format dns servers declaration.
 726         my $line = "";
 727
 728         # Check if the system has configured nameservers.
 729         if (@nameservers) {
 730                 # Add the GREEN address as DNS servers.
 731                 push(@nameservers, $netsettings{'GREEN_ADDRESS'});
 732
 733                 # Check if a BLUE zone exists.
 734                 if ($netsettings{'BLUE_ADDRESS'}) {
 735                         # Add the BLUE address to the array of nameservers.
 736                         push(@nameservers, $netsettings{'BLUE_ADDRESS'});
 737                 }
 738
 739                 # Generate the line which will be written to the DNS servers file.
 740                 $line = join(",", @nameservers);
 741         } else {
 742                 # External net simply contains (any).
 743                 $line = "\$EXTERNAL_NET";
 744         }
 745
 746         # Open file to store the used DNS server addresses.
 747         open(FILE, ">$dns_servers_file") or die "Could not open $dns_servers_file. $!\n";
 748
 749         # Print yaml header.
 750         print FILE "%YAML 1.1\n";
 751         print FILE "---\n\n";
 752
 753         # Print notice about autogenerated file.
 754         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
 755
 756         # Print the generated DNS declaration to the file.
 757         print FILE "DNS_SERVERS:\t\"[$line]\"\n";
 758
 759         # Close file handle.
 760         close(FILE);
 761 }
 762
 763 #
 764 # Function to generate and write the file which contains the HTTP_PORTS definition.
 765 #
 766 sub generate_http_ports_file() {
 767         my %proxysettings;
 768
 769         # Read-in proxy settings
 770         &General::readhash("${General::swroot}/proxy/advanced/settings", \%proxysettings);
 771
 772         # Check if the proxy is enabled.
 773         if (( -e "${General::swroot}/proxy/enable") || (-e "${General::swroot}/proxy/enable_blue")) {
 774                 # Add the proxy port to the array of HTTP ports.
 775                 push(@http_ports, $proxysettings{'PROXY_PORT'});
 776         }
 777
 778         # Check if the transparent mode of the proxy is enabled.
 779         if ((-e "${General::swroot}/proxy/transparent") || (-e "${General::swroot}/proxy/transparent_blue")) {
 780                 # Add the transparent proxy port to the array of HTTP ports.
 781                 push(@http_ports, $proxysettings{'TRANSPARENT_PORT'});
 782         }
 783
 784         # Format HTTP_PORTS declaration.
 785         my $line = "";
 786
 787         # Generate line which will be written to the http ports file.
 788         $line = join(",", @http_ports);
 789
 790         # Open file to store the HTTP_PORTS.
 791         open(FILE, ">$http_ports_file") or die "Could not open $http_ports_file. $!\n";
 792
 793         # Print yaml header.
 794         print FILE "%YAML 1.1\n";
 795         print FILE "---\n\n";
 796
 797         # Print notice about autogenerated file.
 798         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
 799
 800         # Print the generated HTTP_PORTS declaration to the file.
 801         print FILE "HTTP_PORTS:\t\"[$line]\"\n";
 802
 803         # Close file handle.
 804         close(FILE);
 805 }
 806
 807 #
 808 ## Function to generate and write the file for used rulefiles.
 809 #
 810 sub write_used_rulefiles_file(@) {
 811         my @files = @_;
 812
 813         # Open file for used rulefiles.
 814         open (FILE, ">$used_rulefiles_file") or die "Could not write to $used_rulefiles_file. $!\n";
 815
 816         # Write yaml header to the file.
 817         print FILE "%YAML 1.1\n";
 818         print FILE "---\n\n";
 819
 820         # Write header to file.
 821         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
 822
 823         # Allways use the whitelist.
 824         print FILE " - whitelist.rules\n";
 825
 826         # Loop through the array of given files.
 827         foreach my $file (@files) {
 828                 # Check if the given filename exists and write it to the file of used rulefiles.
 829                 if(-f "$rulespath/$file") {
 830                         print FILE " - $file\n";
 831                 }
 832         }
 833
 834         # Close file after writing.
 835         close(FILE);
 836 }
 837
 838 #
 839 ## Function to generate and write the file for modify the ruleset.
 840 #
 841 sub write_modify_sids_file() {
 842         # Get configured settings.
 843         my %idssettings=();
 844         my %rulessettings=();
 845         &General::readhash("$ids_settings_file", \%idssettings);
 846         &General::readhash("$rules_settings_file", \%rulessettings);
 847
 848         # Gather the configured ruleset.
 849         my $ruleset = $rulessettings{'RULES'};
 850
 851         # Open modify sid's file for writing.
 852         open(FILE, ">$modify_sids_file") or die "Could not write to $modify_sids_file. $!\n";
 853
 854         # Write file header.
 855         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
 856
 857         # Check if the traffic only should be monitored.
 858         unless($idssettings{'MONITOR_TRAFFIC_ONLY'} eq 'on') {
 859                 # Suricata is in IPS mode, which means that the rule actions have to be changed
 860                 # from 'alert' to 'drop', however not all rules should be changed.  Some rules
 861                 # exist purely to set a flowbit which is used to convey other information, such
 862                 # as a specific type of file being downloaded, to other rulewhich then check for
 863                 # malware in that file.  Rules which fall into the first category should stay as
 864                 # alert since not all flows of that type contain malware.
 865
 866                 if($ruleset eq 'registered' or $ruleset eq 'subscripted' or $ruleset eq 'community') {
 867                         # These types of rulesfiles contain meta-data which gives the action that should
 868                         # be used when in IPS mode.  Do the following:
 869                         #
 870                         # 1. Disable all rules and set the action to 'drop'
 871                         # 2. Set the action back to 'alert' if the rule contains 'flowbits:noalert;'
 872                         #    This should give rules not in the policy a reasonable default if the user
 873                         #    manually enables them.
 874                         # 3. Enable rules and set actions according to the meta-data strings.
 875
 876                         my $policy = 'balanced';  # Placeholder to allow policy to be changed.
 877
 878                         print FILE <<END;
 879 modifysid * "^#?(?:alert|drop)" | "#drop"
 880 modifysid * "^#drop(.+flowbits:noalert;)" | "#alert\${1}"
 881 modifysid * "^#(?:alert|drop)(.+policy $policy-ips alert)" | "alert\${1}"
 882 modifysid * "^#(?:alert|drop)(.+policy $policy-ips drop)" | "drop\${1}"
 883 END
 884                 } else {
 885                         # These rulefiles don't have the metadata, so set rules to 'drop' unless they
 886                         # contain the string 'flowbits:noalert;'.
 887                         print FILE <<END;
 888 modifysid * "^(#?)(?:alert|drop)" | "\${1}drop"
 889 modifysid * "^(#?)drop(.+flowbits:noalert;)" | "\${1}alert\${2}"
 890 END
 891                 }
 892         }
 893
 894         # Close file handle.
 895         close(FILE);
 896 }
 897
 898 #
 899 ## Function to gather the version of suricata.
 900 #
 901 sub get_suricata_version($) {
 902         my ($format) = @_;
 903
 904         # Execute piped suricata command and return the version information.
 905         open(SURICATA, "suricata -V |") or die "Couldn't execute program: $!";
 906
 907         # Grab and store the output of the piped program.
 908         my $version_string = <SURICATA>;
 909
 910         # Close pipe.
 911         close(SURICATA);
 912
 913         # Remove newlines.
 914         chomp($version_string);
 915
 916         # Grab the version from the version string.
 917         $version_string =~ /([0-9]+([.][0-9]+)+)/;
 918
 919         # Splitt the version into single chunks.
 920         my ($major_ver, $minor_ver, $patchlevel) = split(/\./, $1);
 921
 922         # Check and return the requested version sheme.
 923         if ($format eq "major") {
 924                 # Return the full version.
 925                 return "$major_ver";
 926         } elsif ($format eq "minor") {
 927                 # Return the major and minor part.
 928                 return "$major_ver.$minor_ver";
 929         } else {
 930                 # Return the full version string.
 931                 return "$major_ver.$minor_ver.$patchlevel";
 932         }
 933 }
 934
 935 #
 936 ## Function to generate the rules file with whitelisted addresses.
 937 #
 938 sub generate_ignore_file() {
 939         my %ignored = ();
 940
 941         # SID range 1000000-1999999 Reserved for Local Use
 942         # Put your custom rules in this range to avoid conflicts
 943         my $sid = 1500000;
 944
 945         # Read-in ignoredfile.
 946         &General::readhasharray($IDS::ignored_file, \%ignored);
 947
 948         # Open ignorefile for writing.
 949         open(FILE, ">$IDS::whitelist_file") or die "Could not write to $IDS::whitelist_file. $!\n";
 950
 951         # Config file header.
 952         print FILE "# Autogenerated file.\n";
 953         print FILE "# All user modifications will be overwritten.\n\n";
 954
 955         # Add all user defined addresses to the whitelist.
 956         #
 957         # Check if the hash contains any elements.
 958         if (keys (%ignored)) {
 959                 # Loop through the entire hash and write the host/network
 960                 # and remark to the ignore file.
 961                 while ( (my $key) = each %ignored) {
 962                         my $address = $ignored{$key}[0];
 963                         my $remark = $ignored{$key}[1];
 964                         my $status = $ignored{$key}[2];
 965
 966                         # Check if the status of the entry is "enabled".
 967                         if ($status eq "enabled") {
 968                                 # Check if the address/network is valid.
 969                                 if ((&General::validip($address)) || (&General::validipandmask($address))) {
 970                                         # Write rule line to the file to pass any traffic from this IP
 971                                         print FILE "pass ip $address any -> any any (msg:\"pass all traffic from/to $address\"\; sid:$sid\;)\n";
 972
 973                                         # Increment sid.
 974                                         $sid++;
 975                                 }
 976                         }
 977                 }
 978         }
 979
 980         close(FILE);
 981 }
 982
 983 #
 984 ## Function to set correct ownership for single files and directories.
 985 #
 986
 987 sub set_ownership($) {
 988         my ($target) = @_;
 989
 990         # User and group of the WUI.
 991         my $uname = "nobody";
 992         my $grname = "nobody";
 993
 994         # The chown function implemented in perl requies the user and group as nummeric id's.
 995         my $uid = getpwnam($uname);
 996         my $gid = getgrnam($grname);
 997
 998         # Check if the given target exists.
 999         unless ($target) {
1000                 # Stop the script and print error message.
1001                 die "The $target does not exist. Cannot change the ownership!\n";
1002         }
1003
1004         # Check weather the target is a file or directory.
1005         if (-f $target) {
1006                 # Change ownership ot the single file.
1007                 chown($uid, $gid, "$target");
1008         } elsif (-d $target) {
1009                 # Do a directory listing.
1010                 opendir(DIR, $target) or die $!;
1011                         # Loop through the direcory.
1012                         while (my $file = readdir(DIR)) {
1013
1014                                 # We only want files.
1015                                 next unless (-f "$target/$file");
1016
1017                                 # Set correct ownership for the files.
1018                                 chown($uid, $gid, "$target/$file");
1019                         }
1020
1021                 closedir(DIR);
1022
1023                 # Change ownership of the directory.
1024                 chown($uid, $gid, "$target");
1025         }
1026 }
1027
1028 #
1029 ## Function to read-in the aliases file and returns all configured and enabled aliases.
1030 #
1031 sub get_aliases() {
1032         # Location of the aliases file.
1033         my $aliases_file = "${General::swroot}/ethernet/aliases";
1034
1035         # Array to store the aliases.
1036         my @aliases;
1037
1038         # Check if the file is empty.
1039         if (-z $aliases_file) {
1040                 # Abort nothing to do.
1041                 return;
1042         }
1043
1044         # Open the aliases file.
1045         open(ALIASES, $aliases_file) or die "Could not open $aliases_file. $!\n";
1046
1047         # Loop through the file content.
1048         while (my $line = <ALIASES>) {
1049                 # Remove newlines.
1050                 chomp($line);
1051
1052                 # Splitt line content into single chunks.
1053                 my ($address, $state, $remark) = split(/\,/, $line);
1054
1055                 # Check if the state of the current processed alias is "on".
1056                 if ($state eq "on") {
1057                         # Check if the address is valid.
1058                         if(&Network::check_ip_address($address)) {
1059                                 # Add the alias to the array of aliases.
1060                                 push(@aliases, $address);
1061                         }
1062                 }
1063         }
1064
1065         # Close file handle.
1066         close(ALIASES);
1067
1068         # Return the array.
1069         return @aliases;
1070 }
1071
1072 #
1073 ## Function to grab the current assigned IP-address on red.
1074 #
1075 sub get_red_address() {
1076         # File, which contains the current IP-address of the red interface.
1077         my $file = "${General::swroot}/red/local-ipaddress";
1078
1079         # Check if the file exists.
1080         if (-e $file) {
1081                 # Open the given file.
1082                 open(FILE, "$file") or die "Could not open $file.";
1083
1084                 # Obtain the address from the first line of the file.
1085                 my $address = <FILE>;
1086
1087                 # Close filehandle
1088                 close(FILE);
1089
1090                 # Remove newlines.
1091                 chomp $address;
1092
1093                 # Check if the grabbed address is valid.
1094                 if (&General::validip($address)) {
1095                         # Return the address.
1096                         return $address;
1097                 }
1098         }
1099
1100         # Return nothing.
1101         return;
1102 }
1103
1104 #
1105 ## Function to write the lock file for locking the WUI, while
1106 ## the autoupdate script runs.
1107 #
1108 sub lock_ids_page() {
1109         # Call subfunction to create the file.
1110         &create_empty_file($ids_page_lock_file);
1111 }
1112
1113 #
1114 ## Function to release the lock of the WUI, again.
1115 #
1116 sub unlock_ids_page() {
1117         # Delete lock file.
1118         unlink($ids_page_lock_file);
1119 }
1120
1121 1;