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#!/usr/bin/perl #
# Module:ConntrackUtil.pm
#
# **** License ****
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# 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.
#
# This code was originally developed by Vyatta, Inc.
# Portions created by Vyatta are Copyright (C) 2010 Vyatta, Inc.
# All Rights Reserved.
#
# Author: Gaurav Sinha
# Date: Dec 2011
# Description: Utility scripts for Vyatta conntrack
#
#
# **** End License ****
#
package Vyatta::Conntrack::ConntrackUtil;
use Vyatta::IpTables::Mgr;
use base qw(Exporter);
sub process_protocols {
my $proto = undef;
my %proto_hash = ();
my $PROTO_FILE = '/etc/protocols';
# do nothing if can't open
return if (!open($proto, $PROTO_FILE));
while (<$proto>) {
next if (/^\s*#/);
next if (!/^\S+\s+(\d+)\s+(\S+)\s/);
$proto_hash{$1} = $2;
}
close $proto;
return \%proto_hash;
}
our @EXPORT = qw(check_for_conntrack_hooks, process_protocols, check_and_add_helpers, run_cmd);
#function to find if connection tracking is enabled.
#looks in the iptables to see if any of the features introduced
#its chain in the hooks.
#
#returns one if any hook is present
sub check_for_conntrack_hooks {
my @output = `sudo iptables-nft -L -t raw`;
foreach(@output) {
if (($_ =~ m/WEBPROXY_CONNTRACK/)) {
return 1;
}
if (($_ =~ m/NAT_CONNTRACK/)) {
return 1;
}
if (($_ =~ m/FW_CONNTRACK/)) {
return 1;
}
}
}
1;
sub
check_ct_helper_rules {
my $index;
my $cthelper_chain = "VYOS_CT_HELPER";
foreach my $label ('PREROUTING', 'OUTPUT') {
$index = ipt_find_chain_rule($iptables_cmd, 'raw', $label, $cthelper_chain);
if (!defined($index)) {
# add VYATTA_CT_HELPER to PREROUTING / OUTPUT
print "hook not present\n";
}
}
}
sub check_and_add_helpers {
if (check_for_conntrack_hooks()) {
check_ct_helper_rules();
}
}
sub log_msg {
my $message = shift;
print "DEBUG: $message\n" if $debug_flag;
syslog(LOG_DEBUG, "%s", $message) if $syslog_flag;
}
# Run command and capture output
# run_cmd("$iptables_cmd -t $table -F $name", 1);
# if command fails, then send output to syslog
sub run_cmd {
my ($cmd_to_run, $redirect) = @_;
log_msg("Running: $cmd_to_run");
if ($redirect) {
open (my $out, '-|', $cmd_to_run . ' 2>&1')
or die "Can't run command \"$cmd_to_run\": $!";
my @cmd_out = <$out>;
# if command suceeds to do nothing.
return if (close ($out));
foreach my $line (@cmd_out) {
chomp $line;
syslog(LOG_INFO, "%s", $line);
}
} else {
system($cmd_to_run);
}
}
# end of file
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