#!/usr/bin/perl
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2007-2022  IPFire Team  <info@ipfire.org>                     #
#                                                                             #
# This program 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 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

use strict;
use POSIX;

# Load perl module to talk to the kernel syslog.
use Sys::Syslog qw(:DEFAULT setlogsock);

require '/var/ipfire/general-functions.pl';
require "${General::swroot}/ipblocklist-functions.pl";
require "${General::swroot}/lang.pl";

# Hash to store the settings.
my %settings = ();

# The user and group name as which this script should be run.
my $run_as = 'nobody';

# Get user and group id of the user.
my ( $uid, $gid ) = ( getpwnam $run_as )[ 2, 3 ];

# Check if the script currently runs as root.
if ( $> == 0 ) {
	# Drop privileges and switch to the specified user and group.
	POSIX::setgid( $gid );
	POSIX::setuid( $uid );
}

# Establish the connection to the syslog service.
openlog('ipblocklist', 'cons', 'user');

# Grab the configured providers.
&General::readhash("${General::swroot}/ipblocklist/settings", \%settings);

# Check if the blocklist feature is enabled.
unless ($settings{'ENABLE'} eq "on") {
	# Exit.
	exit 0;
}

# Check if the red device is active.
unless (-e "${General::swroot}/red/active") {
	# Log to syslog.
	&_log_to_syslog("<ERROR> Could not update any blocklist - The system is offline!");

	# Exit.
	exit 1;
}

# Get all available blocklists.
my @blocklists = &IPblocklist::get_blocklists();

# Array to store successfully update blocklists.
# They need to be reloaded.
my @updated_blocklists = ();

# Gather the details, when a list got modified last time.
my %modified = ();

# Read-in data if the file exists.
&General::readhash($IPblocklist::modified_file, \%modified ) if (-e $IPblocklist::modified_file);

# Loop through the array of blocklists.
foreach my $blocklist (@blocklists) {
	# Skip if the blocklist is not enabled.
	next if($settings{$blocklist} ne "on");

	# Get current time.
	my $time = time();

	# Get time, when the blocklist has been downloaded last.
	my $last_download_time = $modified{$blocklist};

	# Get the holdoff rate in seconds for the current processed blocklist.
	my $rate_time = &IPblocklist::get_holdoff_rate($blocklist);

	# Calculate holdoff time.
	my $holdoff_time = $last_download_time + $rate_time;

	# Check if enough time has passed since the last download of the list.
	if ($time <= $holdoff_time) {
		# To frequent updates, log to syslog.
		&_log_to_syslog("<INFO> Skipping $blocklist blocklist - Too frequent update attempts!");

		# Skip this provider.
		next;
	}
	
	# Try to download and update the blocklist.
	my $return = &IPblocklist::download_and_create_blocklist($blocklist);

	# Check if we got a return code.
	if ($return) {
		# Handle different return codes.
		if ($return eq "not_modified") {
			# Log notice to syslog.
			&_log_to_syslog("<INFO> Skipping $blocklist blocklist - It has not been modified!");
		} elsif ($return eq "dl_error") {
			# Log error to the syslog.
			&_log_to_syslog("<ERROR> Could not update $blocklist blocklist - Download error\!");
		} else {
			# Log error to syslog.
			&_log_to_syslog("<ERROR> Could not update $blocklist blocklist - Unexpected error\!");
		}
	} else {
		# Log successfull update.
		&_log_to_syslog("<INFO> Successfully updated $blocklist blocklist.");

		# Add the list to the array of updated blocklists.
		push(@updated_blocklists, $blocklist);
	}
}

# Check if a blocklist has been updated and therefore needs to be reloaded.
if (@updated_blocklists) {
	# Loop through the array.
	foreach my $updated_blocklist (@updated_blocklists) {
		# Get the blocklist file.
		my $ipset_db_file = &IPblocklist::get_ipset_db_file($updated_blocklist);

		# Call safe system function to reload/update the blocklist.
		&General::system("ipset", "restore", "-f", "$ipset_db_file");

		# The set name contains a "v4" as suffix.
		my $set_name = "$updated_blocklist" . "v4";

		# Swap the sets to use the new one.
		&General::system("ipset", "swap", "$set_name", "$updated_blocklist");

		# Destroy the old blocklist.
		&General::system("ipset", "destroy", "$set_name");
	}
}

END {
	# Close connection to syslog.
	closelog();
}

#
# Tiny function to sent the error message to the syslog.
#
sub _log_to_syslog($) {
	my ($message) = @_;

	# The syslog function works best with an array based input,
	# so generate one before passing the message details to syslog.
	my @syslog = ("ERR", "$message");

	# Send the log message.
	syslog(@syslog);
}

1;
