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 main file for providers ruleset inclusion exists.
  36 our $suricata_used_providers_file = "$settingsdir/suricata-used-providers.yaml";
  37
  38 # File for static ruleset inclusions.
  39 our $suricata_static_rulefiles_file = "$settingsdir/suricata-static-included-rulefiles.yaml";
  40
  41 # File where the addresses of the homenet are stored.
  42 our $homenet_file = "$settingsdir/suricata-homenet.yaml";
  43
  44 # File where the addresses of the used DNS servers are stored.
  45 our $dns_servers_file = "$settingsdir/suricata-dns-servers.yaml";
  46
  47 # File where the HTTP ports definition is stored.
  48 our $http_ports_file = "$settingsdir/suricata-http-ports.yaml";
  49
  50 # File which contains includes for provider specific rule modifications.
  51 our $oinkmaster_provider_includes_file = "$settingsdir/oinkmaster-provider-includes.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 # File which stores the used and configured ruleset providers.
  60 our $providers_settings_file = "$settingsdir/providers-settings";
  61
  62 # File which stores the configured settings for whitelisted addresses.
  63 our $ignored_file = "$settingsdir/ignored";
  64
  65 # Location where the downloaded rulesets are stored.
  66 our $dl_rules_path = "/var/tmp";
  67
  68 # File to store any errors, which also will be read and displayed by the wui.
  69 our $storederrorfile = "/tmp/ids_storederror";
  70
  71 # File to lock the WUI, while the autoupdate script runs.
  72 our $ids_page_lock_file = "/tmp/ids_page_locked";
  73
  74 # Location where the rulefiles are stored.
  75 our $rulespath = "/var/lib/suricata";
  76
  77 # Location of the classification file.
  78 our $classification_file = "$rulespath/classification.config";
  79
  80 # Location of the sid to msg mappings file.
  81 our $sid_msg_file = "$rulespath/sid-msg.map";
  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 # Temporary directory where the extracted rules files will be stored.
 106 my $tmp_rules_directory = "$tmp_directory/rules";
 107
 108 # Temporary directory where the extracted additional config files will be stored.
 109 my $tmp_conf_directory = "$tmp_directory/conf";
 110
 111 # Array with allowed commands of suricatactrl.
 112 my @suricatactrl_cmds = ( 'start', 'stop', 'restart', 'reload', 'fix-rules-dir', 'cron' );
 113
 114 # Array with supported cron intervals.
 115 my @cron_intervals = ('off', 'daily', 'weekly' );
 116
 117 # Array which contains the HTTP ports, which statically will be declared as HTTP_PORTS in the
 118 # http_ports_file.
 119 my @http_ports = ('80', '81');
 120
 121 # Array which contains a list of rulefiles which always will be included if they exist.
 122 my @static_included_rulefiles = ('local.rules', 'whitelist.rules' );
 123
 124 # Hash which allows to convert the download type (dl_type) to a file suffix.
 125 my %dl_type_to_suffix = (
 126         "archive" => ".tar.gz",
 127         "plain" => ".rules",
 128 );
 129
 130 #
 131 ## Function to check and create all IDS related files, if the does not exist.
 132 #
 133 sub check_and_create_filelayout() {
 134         # Check if the files exist and if not, create them.
 135         unless (-f "$oinkmaster_provider_includes_file") { &create_empty_file($oinkmaster_provider_includes_file); }
 136         unless (-f "$modify_sids_file") { &create_empty_file($modify_sids_file); }
 137         unless (-f "$suricata_used_providers_file") { &create_empty_file($suricata_used_providers_file); }
 138         unless (-f "$ids_settings_file") { &create_empty_file($ids_settings_file); }
 139         unless (-f "$providers_settings_file") { &create_empty_file($providers_settings_file); }
 140         unless (-f "$ignored_file") { &create_empty_file($ignored_file); }
 141         unless (-f "$whitelist_file" ) { &create_empty_file($whitelist_file); }
 142 }
 143
 144 #
 145 ## Function to get a list of all available ruleset providers.
 146 ##
 147 ## They will be returned as a sorted array.
 148 #
 149 sub get_ruleset_providers() {
 150         my @providers;
 151
 152         # Loop through the hash of providers.
 153         foreach my $provider ( keys %IDS::Ruleset::Providers ) {
 154                 # Add the provider to the array.
 155                 push(@providers, $provider);
 156         }
 157
 158         # Sort and return the array.
 159         return sort(@providers);
 160 }
 161
 162 #
 163 ## Function to get a list of all enabled ruleset providers.
 164 ##
 165 ## They will be returned as an array.
 166 #
 167 sub get_enabled_providers () {
 168         my %used_providers = ();
 169
 170         # Array to store the enabled providers.
 171         my @enabled_providers = ();
 172
 173         # Read-in the providers config file.
 174         &General::readhasharray("$providers_settings_file", \%used_providers);
 175
 176         # Loop through the hash of used_providers.
 177         foreach my $id (keys %used_providers) {
 178                 # Skip disabled providers.
 179                 next unless ($used_providers{$id}[3] eq "enabled");
 180
 181                 # Grab the provider handle.
 182                 my $provider = "$used_providers{$id}[0]";
 183
 184                 # Add the provider to the array of enabled providers.
 185                 push(@enabled_providers, $provider);
 186         }
 187
 188         # Return the array.
 189         return @enabled_providers;
 190 }
 191
 192 #
 193 ## Function for checking if at least 300MB of free disk space are available
 194 ## on the "/var" partition.
 195 #
 196 sub checkdiskspace () {
 197         # Call diskfree to gather the free disk space of /var.
 198         my @df = &General::system_output("/bin/df", "-B", "M", "/var");
 199
 200         # Loop through the output.
 201         foreach my $line (@df) {
 202                 # Ignore header line.
 203                 next if $line =~ m/^Filesystem/;
 204
 205                 # Search for a line with the device information.
 206                 if ($line =~ m/dev/ ) {
 207                         # Split the line into single pieces.
 208                         my @values = split(' ', $line);
 209                         my ($filesystem, $blocks, $used, $available, $used_perenctage, $mounted_on) = @values;
 210
 211                         # Check if the available disk space is more than 300MB.
 212                         if ($available < 300) {
 213                                 # Log error to syslog.
 214                                 &_log_to_syslog("Not enough free disk space on /var. Only $available MB from 300 MB available.");
 215
 216                                 # Exit function and return "1" - False.
 217                                 return 1;
 218                         }
 219                 }
 220         }
 221
 222         # Everything okay, return nothing.
 223         return;
 224 }
 225
 226 #
 227 ## This function is responsible for downloading the configured IDS rulesets or if no one is specified
 228 ## all configured rulesets will be downloaded.
 229 ##
 230 ## * At first it gathers all configured ruleset providers, initialize the downloader and sets an
 231 ##   upstream proxy if configured.
 232 ## * After that, the given ruleset or in case all rulesets should be downloaded, it will determine wether it
 233 ##   is enabled or not.
 234 ## * The next step will be to generate the final download url, by obtaining the URL for the desired
 235 ##   ruleset, add the settings for the upstream proxy.
 236 ## * Finally the function will grab all the rules files or tarballs from the servers.
 237 #
 238 sub downloadruleset ($) {
 239         my ($provider) = @_;
 240
 241         # If no provider is given default to "all".
 242         $provider //= 'all';
 243
 244         # Hash to store the providers and access id's, for which rules should be downloaded.
 245         my %sheduled_providers = ();
 246
 247         # Get used provider settings.
 248         my %used_providers = ();
 249         &General::readhasharray("$providers_settings_file", \%used_providers);
 250
 251         # Check if a ruleset has been configured.
 252         unless(%used_providers) {
 253                 # Log that no ruleset has been configured and abort.
 254                 &_log_to_syslog("No ruleset provider has been configured.");
 255
 256                 # Return "1".
 257                 return 1;
 258         }
 259
 260         # Read proxysettings.
 261         my %proxysettings=();
 262         &General::readhash("${General::swroot}/proxy/settings", \%proxysettings);
 263
 264         # Load required perl module to handle the download.
 265         use LWP::UserAgent;
 266
 267         # Init the download module.
 268         my $downloader = LWP::UserAgent->new;
 269
 270         # Set timeout to 10 seconds.
 271         $downloader->timeout(10);
 272
 273         # Check if an upstream proxy is configured.
 274         if ($proxysettings{'UPSTREAM_PROXY'}) {
 275                 my $proxy_url;
 276
 277                 $proxy_url = "http://";
 278
 279                 # Check if the proxy requires authentication.
 280                 if (($proxysettings{'UPSTREAM_USER'}) && ($proxysettings{'UPSTREAM_PASSWORD'})) {
 281                         $proxy_url .= "$proxysettings{'UPSTREAM_USER'}\:$proxysettings{'UPSTREAM_PASSWORD'}\@";
 282                 }
 283
 284                 # Add proxy server address and port.
 285                 $proxy_url .= $proxysettings{'UPSTREAM_PROXY'};
 286
 287                 # Setup proxy settings.
 288                 $downloader->proxy(['http', 'https'], $proxy_url);
 289         }
 290
 291         # Loop through the hash of configured providers.
 292         foreach my $id ( keys %used_providers ) {
 293                 # Skip providers which are not enabled.
 294                 next if ($used_providers{$id}[3] ne "enabled");
 295
 296                 # Obtain the provider handle.
 297                 my $provider_handle = $used_providers{$id}[0];
 298
 299                 # Handle update off all providers.
 300                 if (($provider eq "all") || ($provider_handle eq "$provider")) {
 301                         # Add provider handle and it's id to the hash of sheduled providers.
 302                         $sheduled_providers{$provider_handle} = $id;
 303                 }
 304         }
 305
 306         # Loop through the hash of sheduled providers.
 307         foreach my $provider ( keys %sheduled_providers) {
 308                 # Grab the download url for the provider.
 309                 my $url = $IDS::Ruleset::Providers{$provider}{'dl_url'};
 310
 311                 # Check if the provider requires a subscription.
 312                 if ($IDS::Ruleset::Providers{$provider}{'requires_subscription'} eq "True") {
 313                         # Grab the previously stored access id for the provider from hash.
 314                         my $id = $sheduled_providers{$provider};
 315
 316                         # Grab the subscription code.
 317                         my $subscription_code = $used_providers{$id}[1];
 318
 319                         # Add the subscription code to the download url.
 320                         $url =~ s/\<subscription_code\>/$subscription_code/g;
 321
 322                 }
 323
 324                 # Abort if no url could be determined for the provider.
 325                 unless ($url) {
 326                         # Log error and abort.
 327                         &_log_to_syslog("Unable to gather a download URL for the selected ruleset provider.");
 328                         return 1;
 329                 }
 330
 331                 # Variable to store the filesize of the remote object.
 332                 my $remote_filesize;
 333
 334                 # The sourcfire (snort rules) does not allow to send "HEAD" requests, so skip this check
 335                 # for this webserver.
 336                 #
 337                 # Check if the ruleset source contains "snort.org".
 338                 unless ($url =~ /\.snort\.org/) {
 339                         # Pass the requrested url to the downloader.
 340                         my $request = HTTP::Request->new(HEAD => $url);
 341
 342                         # Accept the html header.
 343                         $request->header('Accept' => 'text/html');
 344
 345                         # Perform the request and fetch the html header.
 346                         my $response = $downloader->request($request);
 347
 348                         # Check if there was any error.
 349                         unless ($response->is_success) {
 350                                 # Obtain error.
 351                                 my $error = $response->status_line();
 352
 353                                 # Log error message.
 354                                 &_log_to_syslog("Unable to download the ruleset. \($error\)");
 355
 356                                 # Return "1" - false.
 357                                 return 1;
 358                         }
 359
 360                         # Assign the fetched header object.
 361                         my $header = $response->headers();
 362
 363                         # Grab the remote file size from the object and store it in the
 364                         # variable.
 365                         $remote_filesize = $header->content_length;
 366                 }
 367
 368                 # Load perl module to deal with temporary files.
 369                 use File::Temp;
 370
 371                 # Generate temporary file name, located in "/var/tmp" and with a suffix of ".tmp".
 372                 my $tmp = File::Temp->new( SUFFIX => ".tmp", DIR => "/var/tmp/", UNLINK => 0 );
 373                 my $tmpfile = $tmp->filename();
 374
 375                 # Pass the requested url to the downloader.
 376                 my $request = HTTP::Request->new(GET => $url);
 377
 378                 # Perform the request and save the output into the tmpfile.
 379                 my $response = $downloader->request($request, $tmpfile);
 380
 381                 # Check if there was any error.
 382                 unless ($response->is_success) {
 383                         # Obtain error.
 384                         my $error = $response->content;
 385
 386                         # Log error message.
 387                         &_log_to_syslog("Unable to download the ruleset. \($error\)");
 388
 389                         # Return "1" - false.
 390                         return 1;
 391                 }
 392
 393                 # Load perl stat module.
 394                 use File::stat;
 395
 396                 # Perform stat on the tmpfile.
 397                 my $stat = stat($tmpfile);
 398
 399                 # Grab the local filesize of the downloaded tarball.
 400                 my $local_filesize = $stat->size;
 401
 402                 # Check if both file sizes match.
 403                 if (($remote_filesize) && ($remote_filesize ne $local_filesize)) {
 404                         # Log error message.
 405                         &_log_to_syslog("Unable to completely download the ruleset. ");
 406                         &_log_to_syslog("Only got $local_filesize Bytes instead of $remote_filesize Bytes. ");
 407
 408                         # Delete temporary file.
 409                         unlink("$tmpfile");
 410
 411                         # Return "1" - false.
 412                         return 1;
 413                 }
 414
 415                 # Genarate and assign file name and path to store the downloaded rules file.
 416                 my $dl_rulesfile = &_get_dl_rulesfile($provider);
 417
 418                 # Check if a file name could be obtained.
 419                 unless ($dl_rulesfile) {
 420                         # Log error message.
 421                         &_log_to_syslog("Unable to store the downloaded rules file. ");
 422
 423                         # Delete downloaded temporary file.
 424                         unlink("$tmpfile");
 425
 426                         # Return "1" - false.
 427                 }
 428
 429                 # Load file copy module, which contains the move() function.
 430                 use File::Copy;
 431
 432                 # Overwrite the may existing rulefile or tarball with the downloaded one.
 433                 move("$tmpfile", "$dl_rulesfile");
 434
 435                 # Delete temporary file.
 436                 unlink("$tmpfile");
 437
 438                 # Set correct ownership for the tarball.
 439                 set_ownership("$dl_rulesfile");
 440         }
 441
 442         # If we got here, everything worked fine. Return nothing.
 443         return;
 444 }
 445
 446 #
 447 ## Function to extract a given ruleset.
 448 ##
 449 ## In case the ruleset provider offers a plain file, it simply will
 450 ## be copied.
 451 #
 452 sub extractruleset ($) {
 453         my ($provider) = @_;
 454
 455         # Load perl module to deal with archives.
 456         use Archive::Tar;
 457
 458         # Load perl module to deal with files and path.
 459         use File::Basename;
 460
 461         # Load perl module for file copying.
 462         use File::Copy;
 463
 464         # Get full path and downloaded rulesfile for the given provider.
 465         my $tarball = &_get_dl_rulesfile($provider);
 466
 467         # Check if the file exists.
 468         unless (-f $tarball) {
 469                 &_log_to_syslog("Could not find ruleset file: $tarball");
 470
 471                 # Return nothing.
 472                 return;
 473         }
 474
 475         # Check if the temporary directories exist, otherwise create them.
 476         mkdir("$tmp_directory") unless (-d "$tmp_directory");
 477         mkdir("$tmp_rules_directory") unless (-d "$tmp_rules_directory");
 478         mkdir("$tmp_conf_directory") unless (-d "$tmp_conf_directory");
 479
 480         # Omit the type (dl_type) of the stored ruleset.
 481         my $type = $IDS::Ruleset::Providers{$provider}{'dl_type'};
 482
 483         # Handle the different ruleset types.
 484         if ($type eq "plain") {
 485                 # Generate destination filename an full path.
 486                 my $destination = "$tmp_rules_directory/$provider\-ruleset.rules";
 487
 488                 # Copy the file into the temporary rules directory.
 489                 copy($tarball, $destination);
 490
 491         } elsif ( $type eq "archive") {
 492                 # Initialize the tar module.
 493                 my $tar = Archive::Tar->new($tarball);
 494
 495                 # Get the filelist inside the tarball.
 496                 my @packed_files = $tar->list_files;
 497
 498                 # Loop through the filelist.
 499                 foreach my $packed_file (@packed_files) {
 500                         my $destination;
 501
 502                         # Splitt the packed file into chunks.
 503                         my $file = fileparse($packed_file);
 504
 505                         # Handle msg-id.map file.
 506                         if ("$file" eq "sid-msg.map") {
 507                                 # Set extract destination to temporary config_dir.
 508                                 $destination = "$tmp_conf_directory/$provider\-sid-msg.map";
 509
 510                         # Handle classification.conf
 511                         } elsif ("$file" eq "classification.config") {
 512                                 # Set extract destination to temporary config_dir.
 513                                 $destination = "$tmp_conf_directory/$provider\-classification.config";
 514
 515                         # Handle rules files.
 516                         } elsif ($file =~ m/\.rules$/) {
 517                                 my $rulesfilename;
 518
 519                                 # Splitt the filename into chunks.
 520                                 my @filename = split("-", $file);
 521
 522                                 # Reverse the array.
 523                                 @filename = reverse(@filename);
 524
 525                                 # Get the amount of elements in the array.
 526                                 my $elements = @filename;
 527
 528                                 # Remove last element of the hash.
 529                                 # It contains the vendor name, which will be replaced.
 530                                 if ($elements >= 3) {
 531                                 # Remove last element from hash.
 532                                         pop(@filename);
 533                                 }
 534
 535                                 # Check if the last element of the filename does not
 536                                 # contain the providers name.
 537                                 if ($filename[-1] ne "$provider") {
 538                                         # Add provider name as last element.
 539                                         push(@filename, $provider);
 540                                 }
 541
 542                                 # Reverse the array back.
 543                                 @filename = reverse(@filename);
 544
 545                                 # Generate the name for the rulesfile.
 546                                 $rulesfilename = join("-", @filename);
 547
 548                                 # Set extract destination to temporaray rules_dir.
 549                                 $destination = "$tmp_rules_directory/$rulesfilename";
 550                         } else {
 551                                 # Skip all other files.
 552                                 next;
 553                         }
 554
 555                         # Extract the file to the temporary directory.
 556                         $tar->extract_file("$packed_file", "$destination");
 557                 }
 558         }
 559 }
 560
 561 #
 562 ## A wrapper function to call the oinkmaster script, setup the rules structues and
 563 ## call the functions to merge the additional config files. (classification, sid-msg, etc.).
 564 #
 565 sub oinkmaster () {
 566         # Check if the files in rulesdir have the correct permissions.
 567         &_check_rulesdir_permissions();
 568
 569         # Cleanup the rules directory before filling it with the new rulests.
 570         &_cleanup_rulesdir();
 571
 572         # Get all enabled providers.
 573         my @enabled_providers = &get_enabled_providers();
 574
 575         # Loop through the array of enabled providers.
 576         foreach my $provider (@enabled_providers) {
 577                 # Call the extractruleset function.
 578                 &extractruleset($provider);
 579         }
 580
 581         # Load perl module to talk to the kernel syslog.
 582         use Sys::Syslog qw(:DEFAULT setlogsock);
 583
 584         # Establish the connection to the syslog service.
 585         openlog('oinkmaster', 'cons,pid', 'user');
 586
 587         # Call oinkmaster to generate ruleset.
 588         open(OINKMASTER, "/usr/local/bin/oinkmaster.pl -s -u dir://$tmp_rules_directory -C $settingsdir/oinkmaster.conf -o $rulespath 2>&1 |") or die "Could not execute oinkmaster $!\n";
 589
 590         # Log output of oinkmaster to syslog.
 591         while(<OINKMASTER>) {
 592                 # The syslog function works best with an array based input,
 593                 # so generate one before passing the message details to syslog.
 594                 my @syslog = ("INFO", "$_");
 595
 596                 # Send the log message.
 597                 syslog(@syslog);
 598         }
 599
 600         # Close the pipe to oinkmaster process.
 601         close(OINKMASTER);
 602
 603         # Close the log handle.
 604         closelog();
 605
 606         # Call function to merge the classification files.
 607         &merge_classifications(@enabled_providers);
 608
 609         # Call function to merge the sid to message mapping files.
 610         &merge_sid_msg(@enabled_providers);
 611
 612         # Cleanup temporary directory.
 613         &cleanup_tmp_directory();
 614 }
 615
 616 #
 617 ## Function to merge the classifications for a given amount of providers and write them
 618 ## to the classifications file.
 619 #
 620 sub merge_classifications(@) {
 621         my @providers = @_;
 622
 623         # Hash to store all collected classifications.
 624         my %classifications = ();
 625
 626         # Loop through the given array of providers.
 627         foreach my $provider (@providers) {
 628                 # Generate full path to classification file.
 629                 my $classification_file = "$tmp_conf_directory/$provider\-classification.config";
 630
 631                 # Skip provider if no classification file exists.
 632                 next unless (-f "$classification_file");
 633
 634                 # Open the classification file.
 635                 open(CLASSIFICATION, $classification_file) or die "Could not open file $classification_file. $!\n";
 636
 637                 # Loop through the file content.
 638                 while(<CLASSIFICATION>) {
 639                         # Parse the file and grab the classification details.
 640                         if ($_ =~/.*config classification\: (.*)/) {
 641                                 # Split the grabbed details.
 642                                 my ($short_name, $short_desc, $priority) = split("\,", $1);
 643
 644                                 # Check if the grabbed classification is allready known and the priority value is greater
 645                                 # than the stored one (which causes less priority in the IDS).
 646                                 if (($classifications{$short_name}) && ($classifications{$short_name}[1] >= $priority)) {
 647                                         #Change the priority value to the stricter one.
 648                                         $classifications{$short_name} = [ "$classifications{$short_name}[0]", "$priority" ];
 649                                 } else {
 650                                         # Add the classification to the hash.
 651                                         $classifications{$short_name} = [ "$short_desc", "$priority" ];
 652                                 }
 653                         }
 654                 }
 655
 656                 # Close the file.
 657                 close(CLASSIFICATION);
 658         }
 659
 660         # Open classification file for writing.
 661         open(FILE, ">", "$classification_file") or die "Could not write to $classification_file. $!\n";
 662
 663         # Print notice about autogenerated file.
 664         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n\n";
 665
 666         # Sort and loop through the hash of classifications.
 667         foreach my $key (sort keys %classifications) {
 668                 # Assign some nice variable names for the items.
 669                 my $short_name = $key;
 670                 my $short_desc = $classifications{$key}[0];
 671                 my $priority = $classifications{$key}[1];
 672
 673                 # Write the classification to the file.
 674                 print FILE "config classification: $short_name,$short_desc,$priority\n";
 675         }
 676
 677         # Close file handle.
 678         close(FILE);
 679 }
 680
 681 #
 682 ## Function to merge the "sid to message mapping" files of various given providers.
 683 #
 684 sub merge_sid_msg (@) {
 685         my @providers = @_;
 686
 687         # Hash which contains all the sid to message mappings.
 688         my %mappings = ();
 689
 690         # Loop through the array of given providers.
 691         foreach my $provider (@providers) {
 692                 # Generate full path and filename.
 693                 my $sid_msg_file = "$tmp_conf_directory/$provider\-sid-msg.map";
 694
 695                 # Skip provider if no sid to msg mapping file for this provider exists.
 696                 next unless (-f $sid_msg_file);
 697
 698                 # Open the file.
 699                 open(MAPPING, $sid_msg_file) or die "Could not open $sid_msg_file. $!\n";
 700
 701                 # Loop through the file content.
 702                 while (<MAPPING>) {
 703                         # Remove newlines.
 704                         chomp($_);
 705
 706                         # Skip lines which do not start with a number,
 707                         next unless ($_ =~ /^\d+/);
 708
 709                         # Split line content and assign it to an array.
 710                         my @line = split(/ \|\| /, $_);
 711
 712                         # Grab the first element (and remove it) from the line array.
 713                         # It contains the sid.
 714                         my $sid = shift(@line);
 715
 716                         # Store the grabbed sid and the remain array as hash value.
 717                         # It still contains the messages, references etc.
 718                         $mappings{$sid} = [@line];
 719                 }
 720
 721                 # Close file handle.
 722                 close(MAPPING);
 723         }
 724
 725         # Open mappings file for writing.
 726         open(FILE, ">", $sid_msg_file) or die "Could not write $sid_msg_file. $!\n";
 727
 728         # Write notice about autogenerated file.
 729         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n\n";
 730
 731         # Loop through the hash of mappings.
 732         foreach my $sid ( sort keys %mappings) {
 733                 # Grab data for the sid.
 734                 my @data = @{$mappings{$sid}};
 735
 736                 # Add the sid to the data array.
 737                 unshift(@data, $sid);
 738
 739                 # Generate line.
 740                 my $line = join(" \|\| ", @data);
 741
 742                 print FILE "$line\n";
 743
 744         }
 745
 746         # Close file handle.
 747         close(FILE);
 748 }
 749
 750 #
 751 ## A very tiny function to move an extracted ruleset from the temporary directory into
 752 ## the rules directory.
 753 #
 754 sub move_tmp_ruleset() {
 755         # Load perl module.
 756         use File::Copy;
 757
 758         # Do a directory listing of the temporary directory.
 759         opendir  DH, $tmp_rules_directory;
 760
 761         # Loop over all files.
 762         while(my $file = readdir DH) {
 763                 # Move them to the rules directory.
 764                 move "$tmp_rules_directory/$file" , "$rulespath/$file";
 765         }
 766
 767         # Close directory handle.
 768         closedir DH;
 769 }
 770
 771 #
 772 ## Function to cleanup the temporary IDS directroy.
 773 #
 774 sub cleanup_tmp_directory () {
 775         # Load rmtree() function from file path perl module.
 776         use File::Path 'rmtree';
 777
 778         # Delete temporary directory and all containing files.
 779         rmtree([ "$tmp_directory" ]);
 780 }
 781
 782 #
 783 ## Function to do all the logging stuff if the downloading or updating of the ruleset fails.
 784 #
 785 sub log_error ($) {
 786         my ($error) = @_;
 787
 788         # Remove any newline.
 789         chomp($error);
 790
 791         # Call private function to log the error message to syslog.
 792         &_log_to_syslog($error);
 793
 794         # Call private function to write/store the error message in the storederrorfile.
 795         &_store_error_message($error);
 796 }
 797
 798 #
 799 ## Function to log a given error message to the kernel syslog.
 800 #
 801 sub _log_to_syslog ($) {
 802         my ($message) = @_;
 803
 804         # Load perl module to talk to the kernel syslog.
 805         use Sys::Syslog qw(:DEFAULT setlogsock);
 806
 807         # The syslog function works best with an array based input,
 808         # so generate one before passing the message details to syslog.
 809         my @syslog = ("ERR", "<ERROR> $message");
 810
 811         # Establish the connection to the syslog service.
 812         openlog('oinkmaster', 'cons,pid', 'user');
 813
 814         # Send the log message.
 815         syslog(@syslog);
 816
 817         # Close the log handle.
 818         closelog();
 819 }
 820
 821 #
 822 ## Private function to write a given error message to the storederror file.
 823 #
 824 sub _store_error_message ($) {
 825         my ($message) = @_;
 826
 827         # Remove any newline.
 828         chomp($message);
 829
 830         # Open file for writing.
 831         open (ERRORFILE, ">$storederrorfile") or die "Could not write to $storederrorfile. $!\n";
 832
 833         # Write error to file.
 834         print ERRORFILE "$message\n";
 835
 836         # Close file.
 837         close (ERRORFILE);
 838
 839         # Set correct ownership for the file.
 840         &set_ownership("$storederrorfile");
 841 }
 842
 843 #
 844 ## Private function to get the path and filename for a downloaded ruleset by a given provider.
 845 #
 846 sub _get_dl_rulesfile($) {
 847         my ($provider) = @_;
 848
 849         # Gather the download type for the given provider.
 850         my $dl_type = $IDS::Ruleset::Providers{$provider}{'dl_type'};
 851
 852         # Obtain the file suffix for the download file type.
 853         my $suffix = $dl_type_to_suffix{$dl_type};
 854
 855         # Check if a suffix has been found.
 856         unless ($suffix) {
 857                 # Abort return - nothing.
 858                 return;
 859         }
 860
 861         # Generate the full filename and path for the stored rules file.
 862         my $rulesfile = "$dl_rules_path/$dl_rulesfile_prefix-$provider$suffix";
 863
 864         # Return the generated filename.
 865         return $rulesfile;
 866 }
 867
 868 #
 869 ## Tiny function to delete the stored ruleset file or tarball for a given provider.
 870 #
 871 sub drop_dl_rulesfile ($) {
 872         my ($provider) = @_;
 873
 874         # Gather the full path and name of the stored rulesfile.
 875         my $rulesfile = &_get_dl_rulesfile($provider);
 876
 877         # Check if the given rulesfile exists.
 878         if (-f $rulesfile) {
 879                 # Delete the stored rulesfile.
 880                 unlink($rulesfile) or die "Could not delete $rulesfile. $!\n";
 881         }
 882 }
 883
 884 #
 885 ## Tiny function to get/generate the full path and filename for the providers oinkmaster
 886 ## modified sids file.
 887 #
 888 sub get_oinkmaster_provider_modified_sids_file ($) {
 889         my ($provider) = @_;
 890
 891         # Generate the filename.
 892         my $filename = "$settingsdir/oinkmaster-$provider-modified-sids.conf";
 893
 894         # Return the filename.
 895         return $filename;
 896 }
 897
 898 #
 899 ## Function to directly altering the oinkmaster provider includes file.
 900 ##
 901 ## Requires tha acition "remove" or "add" and a provider handle.
 902 #
 903 sub alter_oinkmaster_provider_includes_file ($$) {
 904         my ($action, $provider) = @_;
 905
 906         # Call function to get the path and name for the given providers
 907         # oinkmaster modified sids file.
 908         my $provider_modified_sids_file = &get_oinkmaster_provider_modified_sids_file($provider);
 909
 910         # Open the file for reading..
 911         open (FILE, $oinkmaster_provider_includes_file) or die "Could not read $oinkmaster_provider_includes_file. $!\n";
 912
 913         # Read-in file content.
 914         my @lines = <FILE>;
 915
 916         # Close file after reading.
 917         close(FILE);
 918
 919         # Re-open the file for writing.
 920         open(FILE, ">", $oinkmaster_provider_includes_file) or die "Could not write to $oinkmaster_provider_includes_file. $!\n";
 921
 922         # Loop through the file content.
 923         foreach my $line (@lines) {
 924                 # Remove newlines.
 925                 chomp($line);
 926
 927                 # Skip line if we found our given provider and the action should be remove.
 928                 next if (($line =~ /$provider/) && ($action eq "remove"));
 929
 930                 # Write the read-in line back to the file.
 931                 print FILE "$line\n";
 932         }
 933
 934         # Check if the file exists and add the provider if requested.
 935         if ((-f $provider_modified_sids_file) && ($action eq "add")) {
 936                 print FILE "include $provider_modified_sids_file\n";
 937         }
 938
 939         # Close file handle.
 940         close(FILE);
 941 }
 942
 943 #
 944 ## Function to read-in the given enabled or disables sids file.
 945 #
 946 sub read_enabled_disabled_sids_file($) {
 947         my ($file) = @_;
 948
 949         # Temporary hash to store the sids and their state. It will be
 950         # returned at the end of this function.
 951         my %temphash;
 952
 953         # Open the given filename.
 954         open(FILE, "$file") or die "Could not open $file. $!\n";
 955
 956         # Loop through the file.
 957         while(<FILE>) {
 958                 # Remove newlines.
 959                 chomp $_;
 960
 961                 # Skip blank lines.
 962                 next if ($_ =~ /^\s*$/);
 963
 964                 # Skip coments.
 965                 next if ($_ =~ /^\#/);
 966
 967                 # Splitt line into sid and state part.
 968                 my ($state, $sid) = split(" ", $_);
 969
 970                 # Skip line if the sid is not numeric.
 971                 next unless ($sid =~ /\d+/ );
 972
 973                 # Check if the sid was enabled.
 974                 if ($state eq "enablesid") {
 975                         # Add the sid and its state as enabled to the temporary hash.
 976                         $temphash{$sid} = "enabled";
 977                 # Check if the sid was disabled.
 978                 } elsif ($state eq "disablesid") {
 979                         # Add the sid and its state as disabled to the temporary hash.
 980                         $temphash{$sid} = "disabled";
 981                 # Invalid state - skip the current sid and state.
 982                 } else {
 983                         next;
 984                 }
 985         }
 986
 987         # Close filehandle.
 988         close(FILE);
 989
 990         # Return the hash.
 991         return %temphash;
 992 }
 993
 994 #
 995 ## Function to check if the IDS is running.
 996 #
 997 sub ids_is_running () {
 998         if(-f $idspidfile) {
 999                 # Open PID file for reading.
1000                 open(PIDFILE, "$idspidfile") or die "Could not open $idspidfile. $!\n";
1001
1002                 # Grab the process-id.
1003                 my $pid = <PIDFILE>;
1004
1005                 # Close filehandle.
1006                 close(PIDFILE);
1007
1008                 # Remove any newline.
1009                 chomp($pid);
1010
1011                 # Check if a directory for the process-id exists in proc.
1012                 if(-d "/proc/$pid") {
1013                         # The IDS daemon is running return the process id.
1014                         return $pid;
1015                 }
1016         }
1017
1018         # Return nothing - IDS is not running.
1019         return;
1020 }
1021
1022 #
1023 ## Function to call suricatactrl binary with a given command.
1024 #
1025 sub call_suricatactrl ($) {
1026         # Get called option.
1027         my ($option, $interval) = @_;
1028
1029         # Loop through the array of supported commands and check if
1030         # the given one is part of it.
1031         foreach my $cmd (@suricatactrl_cmds) {
1032                 # Skip current command unless the given one has been found.
1033                 next unless($cmd eq $option);
1034
1035                 # Check if the given command is "cron".
1036                 if ($option eq "cron") {
1037                         # Check if an interval has been given.
1038                         if ($interval) {
1039                                 # Check if the given interval is valid.
1040                                 foreach my $element (@cron_intervals) {
1041                                         # Skip current element until the given one has been found.
1042                                         next unless($element eq $interval);
1043
1044                                         # Call the suricatactrl binary and pass the "cron" command
1045                                         # with the requrested interval.
1046                                         &General::system("$suricatactrl", "$option", "$interval");
1047
1048                                         # Return "1" - True.
1049                                         return 1;
1050                                 }
1051                         }
1052
1053                         # If we got here, the given interval is not supported or none has been given. - Return nothing.
1054                         return;
1055                 } else {
1056                         # Call the suricatactrl binary and pass the requrested
1057                         # option to it.
1058                         &General::system("$suricatactrl", "$option");
1059
1060                         # Return "1" - True.
1061                         return 1;
1062                 }
1063         }
1064
1065         # Command not found - return nothing.
1066         return;
1067 }
1068
1069 #
1070 ## Function to create a new empty file.
1071 #
1072 sub create_empty_file($) {
1073         my ($file) = @_;
1074
1075         # Check if the given file exists.
1076         if(-e $file) {
1077                 # Do nothing to prevent from overwriting existing files.
1078                 return;
1079         }
1080
1081         # Open the file for writing.
1082         open(FILE, ">$file") or die "Could not write to $file. $!\n";
1083
1084         # Close file handle.
1085         close(FILE);
1086
1087         # Return true.
1088         return 1;
1089 }
1090
1091 #
1092 ## Private function to check if the file permission of the rulespath are correct.
1093 ## If not, call suricatactrl to fix them.
1094 #
1095 sub _check_rulesdir_permissions() {
1096         # Check if the rulepath main directory is writable.
1097         unless (-W $rulespath) {
1098                 # If not call suricatctrl to fix it.
1099                 &call_suricatactrl("fix-rules-dir");
1100         }
1101
1102         # Open snort rules directory and do a directory listing.
1103         opendir(DIR, $rulespath) or die $!;
1104         # Loop through the direcory.
1105         while (my $file = readdir(DIR)) {
1106                 # We only want files.
1107                 next unless (-f "$rulespath/$file");
1108
1109                 # Check if the file is writable by the user.
1110                 if (-W "$rulespath/$file") {
1111                         # Everything is okay - go on to the next file.
1112                         next;
1113                 } else {
1114                         # There are wrong permissions, call suricatactrl to fix it.
1115                         &call_suricatactrl("fix-rules-dir");
1116                 }
1117         }
1118 }
1119
1120 #
1121 ## Private function to cleanup the directory which contains
1122 ## the IDS rules, before extracting and modifing the new ruleset.
1123 #
1124 sub _cleanup_rulesdir() {
1125         # Open rules directory and do a directory listing.
1126         opendir(DIR, $rulespath) or die $!;
1127
1128         # Loop through the direcory.
1129         while (my $file = readdir(DIR)) {
1130                 # We only want files.
1131                 next unless (-f "$rulespath/$file");
1132
1133                 # Skip element if it has config as file extension.
1134                 next if ($file =~ m/\.config$/);
1135
1136                 # Skip rules file for whitelisted hosts.
1137                 next if ("$rulespath/$file" eq $whitelist_file);
1138
1139                 # Skip rules file with local rules.
1140                 next if ("$rulespath/$file" eq $local_rules_file);
1141
1142                 # Delete the current processed file, if not, exit this function
1143                 # and return an error message.
1144                 unlink("$rulespath/$file") or return "Could not delete $rulespath/$file. $!\n";
1145         }
1146
1147         # Return nothing;
1148         return;
1149 }
1150
1151 #
1152 ## Function to generate the file which contains the home net information.
1153 #
1154 sub generate_home_net_file() {
1155         my %netsettings;
1156
1157         # Read-in network settings.
1158         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
1159
1160         # Get available network zones.
1161         my @network_zones = &Network::get_available_network_zones();
1162
1163         # Temporary array to store network address and prefix of the configured
1164         # networks.
1165         my @networks;
1166
1167         # Loop through the array of available network zones.
1168         foreach my $zone (@network_zones) {
1169                 # Check if the current processed zone is red.
1170                 if($zone eq "red") {
1171                         # Grab the IP-address of the red interface.
1172                         my $red_address = &get_red_address();
1173
1174                         # Check if an address has been obtained.
1175                         if ($red_address) {
1176                                 # Generate full network string.
1177                                 my $red_network = join("/", $red_address, "32");
1178
1179                                 # Add the red network to the array of networks.
1180                                 push(@networks, $red_network);
1181                         }
1182
1183                         # Check if the configured RED_TYPE is static.
1184                         if ($netsettings{'RED_TYPE'} eq "STATIC") {
1185                                 # Get configured and enabled aliases.
1186                                 my @aliases = &get_aliases();
1187
1188                                 # Loop through the array.
1189                                 foreach my $alias (@aliases) {
1190                                         # Add "/32" prefix.
1191                                         my $network = join("/", $alias, "32");
1192
1193                                         # Add the generated network to the array of networks.
1194                                         push(@networks, $network);
1195                                 }
1196                         }
1197                 # Process remaining network zones.
1198                 } else {
1199                         # Convert current zone name into upper case.
1200                         $zone = uc($zone);
1201
1202                         # Generate key to access the required data from the netsettings hash.
1203                         my $zone_netaddress = $zone . "_NETADDRESS";
1204                         my $zone_netmask = $zone . "_NETMASK";
1205
1206                         # Obtain the settings from the netsettings hash.
1207                         my $netaddress = $netsettings{$zone_netaddress};
1208                         my $netmask = $netsettings{$zone_netmask};
1209
1210                         # Convert the subnetmask into prefix notation.
1211                         my $prefix = &Network::convert_netmask2prefix($netmask);
1212
1213                         # Generate full network string.
1214                         my $network = join("/", $netaddress,$prefix);
1215
1216                         # Check if the network is valid.
1217                         if(&Network::check_subnet($network)) {
1218                                 # Add the generated network to the array of networks.
1219                                 push(@networks, $network);
1220                         }
1221                 }
1222         }
1223
1224         # Format home net declaration.
1225         my $line = "\"[" . join(',', @networks) . "]\"";
1226
1227         # Open file to store the addresses of the home net.
1228         open(FILE, ">$homenet_file") or die "Could not open $homenet_file. $!\n";
1229
1230         # Print yaml header.
1231         print FILE "%YAML 1.1\n";
1232         print FILE "---\n\n";
1233
1234         # Print notice about autogenerated file.
1235         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1236
1237         # Print the generated and required HOME_NET declaration to the file.
1238         print FILE "HOME_NET:\t$line\n";
1239
1240         # Close file handle.
1241         close(FILE);
1242 }
1243
1244 #
1245 # Function to generate and write the file which contains the configured and used DNS servers.
1246 #
1247 sub generate_dns_servers_file() {
1248         # Get the used DNS servers.
1249         my @nameservers = &General::get_nameservers();
1250
1251         # Get network settings.
1252         my %netsettings;
1253         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
1254
1255         # Format dns servers declaration.
1256         my $line = "";
1257
1258         # Check if the system has configured nameservers.
1259         if (@nameservers) {
1260                 # Add the GREEN address as DNS servers.
1261                 push(@nameservers, $netsettings{'GREEN_ADDRESS'});
1262
1263                 # Check if a BLUE zone exists.
1264                 if ($netsettings{'BLUE_ADDRESS'}) {
1265                         # Add the BLUE address to the array of nameservers.
1266                         push(@nameservers, $netsettings{'BLUE_ADDRESS'});
1267                 }
1268
1269                 # Generate the line which will be written to the DNS servers file.
1270                 $line = join(",", @nameservers);
1271         } else {
1272                 # External net simply contains (any).
1273                 $line = "\$EXTERNAL_NET";
1274         }
1275
1276         # Open file to store the used DNS server addresses.
1277         open(FILE, ">$dns_servers_file") or die "Could not open $dns_servers_file. $!\n";
1278
1279         # Print yaml header.
1280         print FILE "%YAML 1.1\n";
1281         print FILE "---\n\n";
1282
1283         # Print notice about autogenerated file.
1284         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1285
1286         # Print the generated DNS declaration to the file.
1287         print FILE "DNS_SERVERS:\t\"[$line]\"\n";
1288
1289         # Close file handle.
1290         close(FILE);
1291 }
1292
1293 #
1294 # Function to generate and write the file which contains the HTTP_PORTS definition.
1295 #
1296 sub generate_http_ports_file() {
1297         my %proxysettings;
1298
1299         # Read-in proxy settings
1300         &General::readhash("${General::swroot}/proxy/advanced/settings", \%proxysettings);
1301
1302         # Check if the proxy is enabled.
1303         if (( -e "${General::swroot}/proxy/enable") || (-e "${General::swroot}/proxy/enable_blue")) {
1304                 # Add the proxy port to the array of HTTP ports.
1305                 push(@http_ports, $proxysettings{'PROXY_PORT'});
1306         }
1307
1308         # Check if the transparent mode of the proxy is enabled.
1309         if ((-e "${General::swroot}/proxy/transparent") || (-e "${General::swroot}/proxy/transparent_blue")) {
1310                 # Add the transparent proxy port to the array of HTTP ports.
1311                 push(@http_ports, $proxysettings{'TRANSPARENT_PORT'});
1312         }
1313
1314         # Format HTTP_PORTS declaration.
1315         my $line = "";
1316
1317         # Generate line which will be written to the http ports file.
1318         $line = join(",", @http_ports);
1319
1320         # Open file to store the HTTP_PORTS.
1321         open(FILE, ">$http_ports_file") or die "Could not open $http_ports_file. $!\n";
1322
1323         # Print yaml header.
1324         print FILE "%YAML 1.1\n";
1325         print FILE "---\n\n";
1326
1327         # Print notice about autogenerated file.
1328         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1329
1330         # Print the generated HTTP_PORTS declaration to the file.
1331         print FILE "HTTP_PORTS:\t\"[$line]\"\n";
1332
1333         # Close file handle.
1334         close(FILE);
1335 }
1336
1337 #
1338 ## Function to generate and write the file for used rulefiles file for a given provider.
1339 ##
1340 ## The function requires as first argument a provider handle, and as second an array with files.
1341 #
1342 sub write_used_provider_rulefiles_file($@) {
1343         my ($provider, @files) = @_;
1344
1345         # Get the path and file for the provider specific used rulefiles file.
1346         my $used_provider_rulesfile_file = &get_used_provider_rulesfile_file($provider);
1347
1348         # Open file for used rulefiles.
1349         open (FILE, ">", "$used_provider_rulesfile_file") or die "Could not write to $used_provider_rulesfile_file. $!\n";
1350
1351         # Write yaml header to the file.
1352         print FILE "%YAML 1.1\n";
1353         print FILE "---\n\n";
1354
1355         # Write header to file.
1356         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1357
1358         # Loop through the array of given files.
1359         foreach my $file (@files) {
1360                 # Check if the given filename exists and write it to the file of used rulefiles.
1361                 if(-f "$rulespath/$file") {
1362                         print FILE " - $file\n";
1363                 }
1364         }
1365
1366         # Close file after writing.
1367         close(FILE);
1368 }
1369
1370 #
1371 ## Function to write the main file for provider rulesfiles inclusions.
1372 ##
1373 ## This function requires an array of provider handles.
1374 #
1375 sub write_main_used_rulefiles_file (@) {
1376         my (@providers) = @_;
1377
1378         # Call function to write the static rulefiles file.
1379         &_write_static_rulefiles_file();
1380
1381         # Open file for used rulefils inclusion.
1382         open (FILE, ">", "$suricata_used_providers_file") or die "Could not write to $suricata_used_providers_file. $!\n";
1383
1384         # Write yaml header to the file.
1385         print FILE "%YAML 1.1\n";
1386         print FILE "---\n\n";
1387
1388         # Write header to file.
1389         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1390
1391         # Loop through the list of given providers.
1392         foreach my $provider (@providers) {
1393                 # Call function to get the providers used rulefiles file.
1394                 my $filename = &get_used_provider_rulesfile_file($provider);
1395
1396                 # Check if the file exists and write it into the used rulefiles file.
1397                 if (-f $filename) {
1398                         # Print the provider to the file.
1399                         print FILE "include\: $filename\n";
1400                 }
1401         }
1402
1403         # Always include the file which hold the static includes.
1404         print FILE "include\: $suricata_static_rulefiles_file\n";
1405
1406         # Close the filehandle after writing.
1407         close(FILE);
1408 }
1409
1410 sub _write_static_rulefiles_file () {
1411         # Open file.
1412         open (FILE, ">", $suricata_static_rulefiles_file) or die "Could not write to $suricata_static_rulefiles_file. $!\n";
1413
1414         # Write yaml header to the file.
1415         print FILE "%YAML 1.1\n";
1416         print FILE "---\n\n";
1417
1418         # Write notice about autogenerated file.
1419         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1420
1421         # Loop through the array of static included rulesfiles.
1422         foreach my $file (@static_included_rulefiles) {
1423                 # Check if the file exists.
1424                 if (-f "$rulespath/$file") {
1425                         # Write the rulesfile name to the file.
1426                         print FILE " - $file\n";
1427                 }
1428         }
1429
1430         # Close the file handle
1431         close(FILE);
1432 }
1433
1434 #
1435 ## Tiny function to generate the full path and name for the used_provider_rulesfile file of a given provider.
1436 #
1437 sub get_used_provider_rulesfile_file ($) {
1438         my ($provider) = @_;
1439
1440         my $filename = "$settingsdir/suricata\-$provider\-used\-rulefiles.yaml";
1441
1442         # Return the gernerated file.
1443         return $filename;
1444 }
1445
1446 #
1447 ## Function to generate and write the file for modify the ruleset.
1448 #
1449 sub write_modify_sids_file() {
1450         # Get configured settings.
1451         my %idssettings=();
1452         &General::readhash("$ids_settings_file", \%idssettings);
1453
1454         # Open modify sid's file for writing.
1455         open(FILE, ">$modify_sids_file") or die "Could not write to $modify_sids_file. $!\n";
1456
1457         # Write file header.
1458         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1459
1460         # Check if the traffic only should be monitored.
1461         unless($idssettings{'MONITOR_TRAFFIC_ONLY'} eq 'on') {
1462                 # Suricata is in IPS mode, which means that the rule actions have to be changed
1463                 # from 'alert' to 'drop', however not all rules should be changed.  Some rules
1464                 # exist purely to set a flowbit which is used to convey other information, such
1465                 # as a specific type of file being downloaded, to other rulewhich then check for
1466                 # malware in that file.  Rules which fall into the first category should stay as
1467                 # alert since not all flows of that type contain malware.
1468
1469                 # These types of rulesfiles contain meta-data which gives the action that should
1470                 # be used when in IPS mode.  Do the following:
1471                 #
1472                 # 1. Disable all rules and set the action to 'drop'
1473                 # 2. Set the action back to 'alert' if the rule contains 'flowbits:noalert;'
1474                 #    This should give rules not in the policy a reasonable default if the user
1475                 #    manually enables them.
1476                 # 3. Enable rules and set actions according to the meta-data strings.
1477
1478                 my $policy = 'balanced';  # Placeholder to allow policy to be changed.
1479
1480                         print FILE <<END;
1481 modifysid * "^#(?:alert|drop)(.+policy $policy-ips alert)" | "alert\${1}"
1482 modifysid * "^#(?:alert|drop)(.+policy $policy-ips drop)" | "drop\${1}"
1483 modifysid * "^(#?)(?:alert|drop)" | "\${1}drop"
1484 modifysid * "^(#?)drop(.+flowbits:noalert;)" | "\${1}alert\${2}"
1485 END
1486                 }
1487
1488         # Close file handle.
1489         close(FILE);
1490 }
1491
1492 #
1493 ## Function to get the ruleset date for a given provider.
1494 ##
1495 ## The function simply return the creation date in a human read-able format
1496 ## of the stored providers rulesfile.
1497 #
1498 sub get_ruleset_date($) {
1499         my ($provider) = @_;
1500
1501         # Load neccessary perl modules for file stat and to format the timestamp.
1502         use File::stat;
1503         use POSIX qw( strftime );
1504
1505         # Get the stored rulesfile for this provider.
1506         my $stored_rulesfile = &_get_dl_rulesfile($provider);
1507
1508         # Call stat on the rulestarball.
1509         my $stat = stat("$stored_rulesfile");
1510
1511         # Get timestamp the file creation.
1512         my $mtime = $stat->mtime;
1513
1514         # Convert into human read-able format.
1515         my $date = strftime('%Y-%m-%d %H:%M:%S', localtime($mtime));
1516
1517         # Return the date.
1518         return $date;
1519 }
1520
1521 #
1522 ## Function to gather the version of suricata.
1523 #
1524 sub get_suricata_version($) {
1525         my ($format) = @_;
1526
1527         # Execute piped suricata command and return the version information.
1528         open(SURICATA, "suricata -V |") or die "Couldn't execute program: $!";
1529
1530         # Grab and store the output of the piped program.
1531         my $version_string = <SURICATA>;
1532
1533         # Close pipe.
1534         close(SURICATA);
1535
1536         # Remove newlines.
1537         chomp($version_string);
1538
1539         # Grab the version from the version string.
1540         $version_string =~ /([0-9]+([.][0-9]+)+)/;
1541
1542         # Splitt the version into single chunks.
1543         my ($major_ver, $minor_ver, $patchlevel) = split(/\./, $1);
1544
1545         # Check and return the requested version sheme.
1546         if ($format eq "major") {
1547                 # Return the full version.
1548                 return "$major_ver";
1549         } elsif ($format eq "minor") {
1550                 # Return the major and minor part.
1551                 return "$major_ver.$minor_ver";
1552         } else {
1553                 # Return the full version string.
1554                 return "$major_ver.$minor_ver.$patchlevel";
1555         }
1556 }
1557
1558 #
1559 ## Function to generate the rules file with whitelisted addresses.
1560 #
1561 sub generate_ignore_file() {
1562         my %ignored = ();
1563
1564         # SID range 1000000-1999999 Reserved for Local Use
1565         # Put your custom rules in this range to avoid conflicts
1566         my $sid = 1500000;
1567
1568         # Read-in ignoredfile.
1569         &General::readhasharray($IDS::ignored_file, \%ignored);
1570
1571         # Open ignorefile for writing.
1572         open(FILE, ">$IDS::whitelist_file") or die "Could not write to $IDS::whitelist_file. $!\n";
1573
1574         # Config file header.
1575         print FILE "# Autogenerated file.\n";
1576         print FILE "# All user modifications will be overwritten.\n\n";
1577
1578         # Add all user defined addresses to the whitelist.
1579         #
1580         # Check if the hash contains any elements.
1581         if (keys (%ignored)) {
1582                 # Loop through the entire hash and write the host/network
1583                 # and remark to the ignore file.
1584                 while ( (my $key) = each %ignored) {
1585                         my $address = $ignored{$key}[0];
1586                         my $remark = $ignored{$key}[1];
1587                         my $status = $ignored{$key}[2];
1588
1589                         # Check if the status of the entry is "enabled".
1590                         if ($status eq "enabled") {
1591                                 # Check if the address/network is valid.
1592                                 if ((&General::validip($address)) || (&General::validipandmask($address))) {
1593                                         # Write rule line to the file to pass any traffic from this IP
1594                                         print FILE "pass ip $address any -> any any (msg:\"pass all traffic from/to $address\"\; sid:$sid\;)\n";
1595
1596                                         # Increment sid.
1597                                         $sid++;
1598                                 }
1599                         }
1600                 }
1601         }
1602
1603         close(FILE);
1604 }
1605
1606 #
1607 ## Function to set correct ownership for single files and directories.
1608 #
1609
1610 sub set_ownership($) {
1611         my ($target) = @_;
1612
1613         # User and group of the WUI.
1614         my $uname = "nobody";
1615         my $grname = "nobody";
1616
1617         # The chown function implemented in perl requies the user and group as nummeric id's.
1618         my $uid = getpwnam($uname);
1619         my $gid = getgrnam($grname);
1620
1621         # Check if the given target exists.
1622         unless ($target) {
1623                 # Stop the script and print error message.
1624                 die "The $target does not exist. Cannot change the ownership!\n";
1625         }
1626
1627         # Check weather the target is a file or directory.
1628         if (-f $target) {
1629                 # Change ownership ot the single file.
1630                 chown($uid, $gid, "$target");
1631         } elsif (-d $target) {
1632                 # Do a directory listing.
1633                 opendir(DIR, $target) or die $!;
1634                         # Loop through the direcory.
1635                         while (my $file = readdir(DIR)) {
1636
1637                                 # We only want files.
1638                                 next unless (-f "$target/$file");
1639
1640                                 # Set correct ownership for the files.
1641                                 chown($uid, $gid, "$target/$file");
1642                         }
1643
1644                 closedir(DIR);
1645
1646                 # Change ownership of the directory.
1647                 chown($uid, $gid, "$target");
1648         }
1649 }
1650
1651 #
1652 ## Function to read-in the aliases file and returns all configured and enabled aliases.
1653 #
1654 sub get_aliases() {
1655         # Location of the aliases file.
1656         my $aliases_file = "${General::swroot}/ethernet/aliases";
1657
1658         # Array to store the aliases.
1659         my @aliases;
1660
1661         # Check if the file is empty.
1662         if (-z $aliases_file) {
1663                 # Abort nothing to do.
1664                 return;
1665         }
1666
1667         # Open the aliases file.
1668         open(ALIASES, $aliases_file) or die "Could not open $aliases_file. $!\n";
1669
1670         # Loop through the file content.
1671         while (my $line = <ALIASES>) {
1672                 # Remove newlines.
1673                 chomp($line);
1674
1675                 # Splitt line content into single chunks.
1676                 my ($address, $state, $remark) = split(/\,/, $line);
1677
1678                 # Check if the state of the current processed alias is "on".
1679                 if ($state eq "on") {
1680                         # Check if the address is valid.
1681                         if(&Network::check_ip_address($address)) {
1682                                 # Add the alias to the array of aliases.
1683                                 push(@aliases, $address);
1684                         }
1685                 }
1686         }
1687
1688         # Close file handle.
1689         close(ALIASES);
1690
1691         # Return the array.
1692         return @aliases;
1693 }
1694
1695 #
1696 ## Function to grab the current assigned IP-address on red.
1697 #
1698 sub get_red_address() {
1699         # File, which contains the current IP-address of the red interface.
1700         my $file = "${General::swroot}/red/local-ipaddress";
1701
1702         # Check if the file exists.
1703         if (-e $file) {
1704                 # Open the given file.
1705                 open(FILE, "$file") or die "Could not open $file.";
1706
1707                 # Obtain the address from the first line of the file.
1708                 my $address = <FILE>;
1709
1710                 # Close filehandle
1711                 close(FILE);
1712
1713                 # Remove newlines.
1714                 chomp $address;
1715
1716                 # Check if the grabbed address is valid.
1717                 if (&General::validip($address)) {
1718                         # Return the address.
1719                         return $address;
1720                 }
1721         }
1722
1723         # Return nothing.
1724         return;
1725 }
1726
1727 #
1728 ## Function to get the used rules files of a given provider.
1729 #
1730 sub read_used_provider_rulesfiles($) {
1731         my ($provider) = @_;
1732
1733         # Array to store the used rulefiles.
1734         my @used_rulesfiles = ();
1735
1736         # Get the used rulesefile file for the provider.
1737         my $rulesfile_file = &get_used_provider_rulesfile_file($provider);
1738
1739         # Check if the a used rulesfile exists for this provider.
1740         if (-f $rulesfile_file) {
1741                 # Open the file or used rulefiles and read-in content.
1742                 open(FILE, $rulesfile_file) or die "Could not open $rulesfile_file. $!\n";
1743
1744                 while (<FILE>) {
1745                         # Assign the current line to a nice variable.
1746                         my $line = $_;
1747
1748                         # Remove newlines.
1749                         chomp($line);
1750
1751                         # Skip comments.
1752                         next if ($line =~ /\#/);
1753
1754                         # Skip blank  lines.
1755                         next if ($line =~ /^\s*$/);
1756
1757                         # Gather the rulefile.
1758                         if ($line =~ /.*- (.*)/) {
1759                                 my $rulefile = $1;
1760
1761                                 # Add the rulefile to the array of used rulesfiles.
1762                                 push(@used_rulesfiles, $rulefile);
1763                         }
1764                 }
1765
1766                 # Close the file.
1767                 close(FILE);
1768         }
1769
1770         # Return the array of used rulesfiles.
1771         return @used_rulesfiles;
1772 }
1773
1774 #
1775 ## Function to write the lock file for locking the WUI, while
1776 ## the autoupdate script runs.
1777 #
1778 sub lock_ids_page() {
1779         # Call subfunction to create the file.
1780         &create_empty_file($ids_page_lock_file);
1781 }
1782
1783 #
1784 ## Function to release the lock of the WUI, again.
1785 #
1786 sub unlock_ids_page() {
1787         # Delete lock file.
1788         unlink($ids_page_lock_file);
1789 }
1790
1791 1;