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 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 # Location and name of the tarball which contains the ruleset.
  32 our $rulestarball = "/var/tmp/idsrules.tar.gz";
  33
  34 # File to store any errors, which also will be read and displayed by the wui.
  35 our $storederrorfile = "/tmp/ids_storederror";
  36
  37 # Location where the rulefiles are stored.
  38 our $rulespath = "/etc/suricata/rules";
  39
  40 # File which contains a list of all supported ruleset sources.
  41 # (Sourcefire, Emergingthreads, etc..)
  42 our $rulesetsourcesfile = "$settingsdir/ruleset-sources";
  43
  44 # The pidfile of the IDS.
  45 our $idspidfile = "/var/run/suricata.pid";
  46
  47 # Location of suricatactrl.
  48 my $suricatactrl = "/usr/local/bin/suricatactrl";
  49
  50 # Array with allowed commands of suricatactrl.
  51 my @suricatactrl_cmds = ( 'start', 'stop', 'restart', 'reload', 'fix-rules-dir' );
  52
  53 #
  54 ## Function for checking if at least 300MB of free disk space are available
  55 ## on the "/var" partition.
  56 #
  57 sub checkdiskspace () {
  58         # Call diskfree to gather the free disk space of /var.
  59         my @df = `/bin/df -B M /var`;
  60
  61         # Loop through the output.
  62         foreach my $line (@df) {
  63                 # Ignore header line.
  64                 next if $line =~ m/^Filesystem/;
  65
  66                 # Search for a line with the device information.
  67                 if ($line =~ m/dev/ ) {
  68                         # Split the line into single pieces.
  69                         my @values = split(' ', $line);
  70                         my ($filesystem, $blocks, $used, $available, $used_perenctage, $mounted_on) = @values;
  71
  72                         # Check if the available disk space is more than 300MB.
  73                         if ($available < 300) {
  74                                 # Log error to syslog.
  75                                 &_log_to_syslog("Not enough free disk space on /var. Only $available MB from 300 MB available.");
  76
  77                                 # Exit function and return "1" - False.
  78                                 return 1;
  79                         }
  80                 }
  81         }
  82
  83         # Everything okay, return nothing.
  84         return;
  85 }
  86
  87 #
  88 ## This function is responsible for downloading the configured snort ruleset.
  89 ##
  90 ## * At first it obtains from the stored snortsettings which ruleset should be downloaded.
  91 ## * The next step is to get the download locations for all available rulesets.
  92 ## * After that, the function will check if an upstream proxy should be used and grab the settings.
  93 ## * The last step will be to generate the final download url, by obtaining the URL for the desired
  94 ##   ruleset, add the settings for the upstream proxy and final grab the rules tarball from the server.
  95 #
  96 sub downloadruleset {
  97         # Get snort settings.
  98         my %snortsettings=();
  99         &General::readhash("$settingsdir/settings", \%snortsettings);
 100
 101         # Check if a ruleset has been configured.
 102         unless($snortsettings{'RULES'}) {
 103                 # Log that no ruleset has been configured and abort.
 104                 &_log_to_syslog("No ruleset source has been configured.");
 105
 106                 # Return "1".
 107                 return 1;
 108         }
 109
 110         # Get all available ruleset locations.
 111         my %rulesetsources=();
 112         &General::readhash($rulesetsourcesfile, \%rulesetsources);
 113
 114         # Read proxysettings.
 115         my %proxysettings=();
 116         &General::readhash("${General::swroot}/proxy/settings", \%proxysettings);
 117
 118         # Load required perl module to handle the download.
 119         use LWP::UserAgent;
 120
 121         # Init the download module.
 122         my $downloader = LWP::UserAgent->new;
 123
 124         # Set timeout to 10 seconds.
 125         $downloader->timeout(10);
 126
 127         # Check if an upstream proxy is configured.
 128         if ($proxysettings{'UPSTREAM_PROXY'}) {
 129                 my ($peer, $peerport) = (/^(?:[a-zA-Z ]+\:\/\/)?(?:[A-Za-z0-9\_\.\-]*?(?:\:[A-Za-z0-9\_\.\-]*?)?\@)?([a-zA-Z0-9\.\_\-]*?)(?:\:([0-9]{1,5}))?(?:\/.*?)?$/);
 130                 my $proxy_url;
 131
 132                 # Check if we got a peer.
 133                 if ($peer) {
 134                         $proxy_url = "http://";
 135
 136                         # Check if the proxy requires authentication.
 137                         if (($proxysettings{'UPSTREAM_USER'}) && ($proxysettings{'UPSTREAM_PASSWORD'})) {
 138                                 $proxy_url .= "$proxysettings{'UPSTREAM_USER'}\:$proxysettings{'UPSTREAM_PASSWORD'}\@";
 139                         }
 140
 141                         # Add proxy server address and port.
 142                         $proxy_url .= "$peer\:$peerport";
 143                 } else {
 144                         # Log error message and break.
 145                         &_log_to_syslog("Could not proper configure the proxy server access.");
 146
 147                         # Return "1" - false.
 148                         return 1;
 149                 }
 150
 151                 # Setup proxy settings.
 152                 $downloader->proxy('http', $proxy_url);
 153         }
 154
 155         # Grab the right url based on the configured vendor.
 156         my $url = $rulesetsources{$snortsettings{'RULES'}};
 157
 158         # Check if the vendor requires an oinkcode and add it if needed.
 159         $url =~ s/\<oinkcode\>/$snortsettings{'OINKCODE'}/g;
 160
 161         # Abort if no url could be determined for the vendor.
 162         unless ($url) {
 163                 # Log error and abort.
 164                 &_log_to_syslog("Unable to gather a download URL for the selected ruleset.");
 165                 return 1;
 166         }
 167
 168         # Pass the requested url to the downloader.
 169         my $request = HTTP::Request->new(GET => $url);
 170
 171         # Perform the request and save the output into the "$rulestarball" file.
 172         my $response = $downloader->request($request, $rulestarball);
 173
 174         # Check if there was any error.
 175         unless ($response->is_success) {
 176                 # Obtain error.
 177                 my $error = $response->content;
 178
 179                 # Log error message.
 180                 &_log_to_syslog("Unable to download the ruleset. \($error\)");
 181
 182                 # Return "1" - false.
 183                 return 1;
 184         }
 185
 186         # If we got here, everything worked fine. Return nothing.
 187         return;
 188 }
 189
 190 #
 191 ## A tiny wrapper function to call the oinkmaster script.
 192 #
 193 sub oinkmaster () {
 194         # Check if the files in rulesdir have the correct permissions.
 195         &_check_rulesdir_permissions();
 196
 197         # Load perl module to talk to the kernel syslog.
 198         use Sys::Syslog qw(:DEFAULT setlogsock);
 199
 200         # Establish the connection to the syslog service.
 201         openlog('oinkmaster', 'cons,pid', 'user');
 202
 203         # Call oinkmaster to generate ruleset.
 204         open(OINKMASTER, "/usr/local/bin/oinkmaster.pl -v -s -u file://$rulestarball -C $settingsdir/oinkmaster.conf -o $rulespath|") or die "Could not execute oinkmaster $!\n";
 205
 206         # Log output of oinkmaster to syslog.
 207         while(<OINKMASTER>) {
 208                 # The syslog function works best with an array based input,
 209                 # so generate one before passing the message details to syslog.
 210                 my @syslog = ("INFO", "$_");
 211
 212                 # Send the log message.
 213                 syslog(@syslog);
 214         }
 215
 216         # Close the pipe to oinkmaster process.
 217         close(OINKMASTER);
 218
 219         # Close the log handle.
 220         closelog();
 221 }
 222
 223 #
 224 ## Function to do all the logging stuff if the downloading or updating of the ruleset fails.
 225 #
 226 sub log_error ($) {
 227         my ($error) = @_;
 228
 229         # Remove any newline.
 230         chomp($error);
 231
 232         # Call private function to log the error message to syslog.
 233         &_log_to_syslog($error);
 234
 235         # Call private function to write/store the error message in the storederrorfile.
 236         &_store_error_message($error);
 237 }
 238
 239 #
 240 ## Function to log a given error message to the kernel syslog.
 241 #
 242 sub _log_to_syslog ($) {
 243         my ($message) = @_;
 244
 245         # Load perl module to talk to the kernel syslog.
 246         use Sys::Syslog qw(:DEFAULT setlogsock);
 247
 248         # The syslog function works best with an array based input,
 249         # so generate one before passing the message details to syslog.
 250         my @syslog = ("ERR", "<ERROR> $message");
 251
 252         # Establish the connection to the syslog service.
 253         openlog('oinkmaster', 'cons,pid', 'user');
 254
 255         # Send the log message.
 256         syslog(@syslog);
 257
 258         # Close the log handle.
 259         closelog();
 260 }
 261
 262 #
 263 ## Private function to write a given error message to the storederror file.
 264 #
 265 sub _store_error_message ($) {
 266         my ($message) = @_;
 267
 268         # Remove any newline.
 269         chomp($message);
 270
 271         # Open file for writing.
 272         open (ERRORFILE, ">$storederrorfile") or die "Could not write to $storederrorfile. $!\n";
 273
 274         # Write error to file.
 275         print ERRORFILE "$message\n";
 276
 277         # Close file.
 278         close (ERRORFILE);
 279 }
 280
 281 #
 282 ## Function to get a list of all available network zones.
 283 #
 284 sub get_available_network_zones () {
 285         # Get netsettings.
 286         my %netsettings = ();
 287         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
 288
 289         # Obtain the configuration type from the netsettings hash.
 290         my $config_type = $netsettings{'CONFIG_TYPE'};
 291
 292         # Hash which contains the conversation from the config mode
 293         # to the existing network interface names. They are stored like
 294         # an array.
 295         #
 296         # Mode "0" red is a modem and green
 297         # Mode "1" red is a netdev and green
 298         # Mode "2" red, green and orange
 299         # Mode "3" red, green and blue
 300         # Mode "4" red, green, blue, orange
 301         my %config_type_to_interfaces = (
 302                 "0" => [ "red", "green" ],
 303                 "1" => [ "red", "green" ],
 304                 "2" => [ "red", "green", "orange" ],
 305                 "3" => [ "red", "green", "blue" ],
 306                 "4" => [ "red", "green", "blue", "orange" ]
 307         );
 308
 309         # Obtain and dereference the corresponding network interaces based on the read
 310         # network config type.
 311         my @network_zones = @{ $config_type_to_interfaces{$config_type} };
 312
 313         # Return them.
 314         return @network_zones;
 315 }
 316
 317 #
 318 ## Function to check if the IDS is running.
 319 #
 320 sub ids_is_running () {
 321         if(-f $idspidfile) {
 322                 # Open PID file for reading.
 323                 open(PIDFILE, "$idspidfile") or die "Could not open $idspidfile. $!\n";
 324
 325                 # Grab the process-id.
 326                 my $pid = <PIDFILE>;
 327
 328                 # Close filehandle.
 329                 close(PIDFILE);
 330
 331                 # Remove any newline.
 332                 chomp($pid);
 333
 334                 # Check if a directory for the process-id exists in proc.
 335                 if(-d "/proc/$pid") {
 336                         # The IDS daemon is running return the process id.
 337                         return $pid;
 338                 }
 339         }
 340
 341         # Return nothing - IDS is not running.
 342         return;
 343 }
 344
 345 #
 346 ## Function to call suricatactrl binary with a given command.
 347 #
 348 sub call_suricatactrl ($) {
 349         # Get called option.
 350         my ($option) = @_;
 351
 352         # Loop through the array of supported commands and check if
 353         # the given one is part of it.
 354         foreach my $cmd (@suricatactrl_cmds) {
 355                 # Skip current command unless the given one has been found.
 356                 next unless($cmd eq $option);
 357
 358                 # Call the suricatactrl binary and pass the requrested
 359                 # option to it.
 360                 system("$suricatactrl $option &>/dev/null");
 361
 362                 # Return "1" - True.
 363                 return 1;
 364         }
 365
 366         # Command not found - return nothing.
 367         return;
 368 }
 369
 370 #
 371 ## Function to create a new empty file.
 372 #
 373 sub create_empty_file($) {
 374         my ($file) = @_;
 375
 376         # Check if the given file exists.
 377         if(-e $file) {
 378                 # Do nothing to prevent from overwriting existing files.
 379                 return;
 380         }
 381
 382         # Open the file for writing.
 383         open(FILE, ">$file") or die "Could not write to $file. $!\n";
 384
 385         # Close file handle.
 386         close(FILE);
 387
 388         # Return true.
 389         return 1;
 390 }
 391
 392 #
 393 ## Private function to check if the file permission of the rulespath are correct.
 394 ## If not, call suricatactrl to fix them.
 395 #
 396 sub _check_rulesdir_permissions() {
 397         # Check if the rulepath main directory is writable.
 398         unless (-W $rulespath) {
 399                 # If not call suricatctrl to fix it.
 400                 &call_suricatactrl("fix-rules-dir");
 401         }
 402
 403         # Open snort rules directory and do a directory listing.
 404         opendir(DIR, $rulespath) or die $!;
 405         # Loop through the direcory.
 406         while (my $file = readdir(DIR)) {
 407                 # We only want files.
 408                 next unless (-f "$rulespath/$file");
 409
 410                 # Check if the file is writable by the user.
 411                 if (-W "$rulespath/$file") {
 412                         # Everything is okay - go on to the next file.
 413                         next;
 414                 } else {
 415                         # There are wrong permissions, call suricatactrl to fix it.
 416                         &call_suricatactrl("fix-rules-dir");
 417                 }
 418         }
 419 }
 420
 421 1;