Files
bpfire/config/cfgroot/ids-functions.pl
2018-08-02 19:31:52 +02:00

258 lines
8.1 KiB
Perl

#!/usr/bin/perl -w
############################################################################
# #
# This file is part of the IPFire Firewall. #
# #
# IPFire is free software; you can redistribute it and/or modify #
# it under the terms of the GNU General Public License as published by #
# the Free Software Foundation; either version 2 of the License, or #
# (at your option) any later version. #
# #
# IPFire is distributed in the hope that it will be useful, #
# but WITHOUT ANY WARRANTY; without even the implied warranty of #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
# GNU General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with IPFire; if not, write to the Free Software #
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA #
# #
# Copyright (C) 2018 IPFire Team <info@ipfire.org>. #
# #
############################################################################
package IDS;
require '/var/ipfire/general-functions.pl';
# Location where all config and settings files are stored.
our $settingsdir = "${General::swroot}/suricata";
# Location and name of the tarball which contains the ruleset.
our $rulestarball = "/var/tmp/idsrules.tar.gz";
# File to store any errors, which also will be read and displayed by the wui.
our $storederrorfile = "/tmp/ids_storederror";
# Location where the rulefiles are stored.
our $rulespath = "/etc/suricata/rules";
# File which contains a list of all supported ruleset sources.
# (Sourcefire, Emergingthreads, etc..)
our $rulesetsourcesfile = "$settingsdir/ruleset-sources";
#
## Function for checking if at least 300MB of free disk space are available
## on the "/var" partition.
#
sub checkdiskspace () {
# Call diskfree to gather the free disk space of /var.
my @df = `/bin/df -B M /var`;
# Loop through the output.
foreach my $line (@df) {
# Ignore header line.
next if $line =~ m/^Filesystem/;
# Search for a line with the device information.
if ($line =~ m/dev/ ) {
# Split the line into single pieces.
my @values = split(' ', $line);
my ($filesystem, $blocks, $used, $available, $used_perenctage, $mounted_on) = @values;
# Check if the available disk space is more than 300MB.
if ($available < 300) {
# Log error to syslog.
&_log_to_syslog("Not enough free disk space on /var. Only $available MB from 300 MB available.");
# Exit function and return "1" - False.
return 1;
}
}
}
# Everything okay, return nothing.
return;
}
#
## This function is responsible for downloading the configured snort ruleset.
##
## * At first it obtains from the stored snortsettings which ruleset should be downloaded.
## * The next step is to get the download locations for all available rulesets.
## * After that, the function will check if an upstream proxy should be used and grab the settings.
## * The last step will be to generate the final download url, by obtaining the URL for the desired
## ruleset, add the settings for the upstream proxy and final grab the rules tarball from the server.
#
sub downloadruleset {
# Get snort settings.
my %snortsettings=();
&General::readhash("$settingsdir/settings", \%snortsettings);
# Get all available ruleset locations.
my %rulesetsources=();
&General::readhash($rulesetsourcesfile, \%rulesetsources);
# Read proxysettings.
my %proxysettings=();
&General::readhash("${General::swroot}/proxy/settings", \%proxysettings);
# Load required perl module to handle the download.
use LWP::UserAgent;
# Init the download module.
my $downloader = LWP::UserAgent->new;
# Set timeout to 10 seconds.
$downloader->timeout(10);
# Check if an upstream proxy is configured.
if ($proxysettings{'UPSTREAM_PROXY'}) {
my ($peer, $peerport) = (/^(?:[a-zA-Z ]+\:\/\/)?(?:[A-Za-z0-9\_\.\-]*?(?:\:[A-Za-z0-9\_\.\-]*?)?\@)?([a-zA-Z0-9\.\_\-]*?)(?:\:([0-9]{1,5}))?(?:\/.*?)?$/);
my $proxy_url;
# Check if we got a peer.
if ($peer) {
$proxy_url = "http://";
# Check if the proxy requires authentication.
if (($proxysettings{'UPSTREAM_USER'}) && ($proxysettings{'UPSTREAM_PASSWORD'})) {
$proxy_url .= "$proxysettings{'UPSTREAM_USER'}\:$proxysettings{'UPSTREAM_PASSWORD'}\@";
}
# Add proxy server address and port.
$proxy_url .= "$peer\:$peerport";
} else {
# Log error message and break.
&_log_to_syslog("Could not proper configure the proxy server access.");
# Return "1" - false.
return 1;
}
# Setup proxy settings.
$downloader->proxy('http', $proxy_url);
}
# Grab the right url based on the configured vendor.
my $url = $rulesetsources{$snortsettings{'RULES'}};
# Check if the vendor requires an oinkcode and add it if needed.
$url =~ s/\<oinkcode\>/$snortsettings{'OINKCODE'}/g;
# Abort if no url could be determined for the vendor.
unless ($url) {
# Log error and abort.
&_log_to_syslog("Unable to gather a download URL for the selected ruleset.");
return 1;
}
# Pass the requested url to the downloader.
my $request = HTTP::Request->new(GET => $url);
# Perform the request and save the output into the "$rulestarball" file.
my $response = $downloader->request($request, $rulestarball);
# Check if there was any error.
unless ($response->is_success) {
# Log error message.
&_log_to_syslog("Unable to download the ruleset. $response->status_line");
# Return "1" - false.
return 1;
}
# If we got here, everything worked fine. Return nothing.
return;
}
#
## A tiny wrapper function to call the oinkmaster script.
#
sub oinkmaster () {
# Load perl module to talk to the kernel syslog.
use Sys::Syslog qw(:DEFAULT setlogsock);
# Establish the connection to the syslog service.
openlog('oinkmaster', 'cons,pid', 'user');
# Call oinkmaster to generate ruleset.
open(OINKMASTER, "/usr/local/bin/oinkmaster.pl -v -s -u file://$rulestarball -C $settingsdir/oinkmaster.conf -o $rulespath|");
# Log output of oinkmaster to syslog.
while(<OINKMASTER>) {
# The syslog function works best with an array based input,
# so generate one before passing the message details to syslog.
my @syslog = ("INFO", "$_");
# Send the log message.
syslog(@syslog);
}
# Close the pipe to oinkmaster process.
close(OINKMASTER);
# Close the log handle.
closelog();
}
#
## Function to do all the logging stuff if the downloading or updating of the ruleset fails.
#
sub log_error ($) {
my ($error) = @_;
# Remove any newline.
chomp($error);
# Call private function to log the error message to syslog.
&_log_to_syslog($error);
# Call private function to write/store the error message in the storederrorfile.
&_store_error_message($error);
}
#
## Function to log a given error message to the kernel syslog.
#
sub _log_to_syslog ($) {
my ($message) = @_;
# Load perl module to talk to the kernel syslog.
use Sys::Syslog qw(:DEFAULT setlogsock);
# The syslog function works best with an array based input,
# so generate one before passing the message details to syslog.
my @syslog = ("ERR", "<ERROR> $message");
# Establish the connection to the syslog service.
openlog('oinkmaster', 'cons,pid', 'user');
# Send the log message.
syslog(@syslog);
# Close the log handle.
closelog();
}
#
## Private function to write a given error message to the storederror file.
#
sub _store_error_message ($) {
my ($message) = @_;
# Remove any newline.
chomp($message);
# Open file for writing.
open (ERRORFILE, ">$storederrorfile") or die "Could not write to $storederrorfile. $!\n";
# Write error to file.
print ERRORFILE "$message\n";
# Close file.
close (ERRORFILE);
}
1;