#!/usr/bin/perl -w
#
# Module: vyatta-wanloadbalance.pl
# 
# 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.
# 
# **** End License ****
#
use lib "/opt/vyatta/share/perl5/";
use Vyatta::Config;
use Vyatta::Misc;
use Vyatta::TypeChecker;

use warnings;
use strict;
use POSIX;
use File::Copy;

sub write_health {
#open conf
    my $config = new Vyatta::Config;

    my $valid = "false";


    if ($config->exists("load-balancing wan disable-source-nat")) {
	print FILE_LCK "disable-source-nat\n";
    }

    $config->setLevel("load-balancing wan interface-health");
    my @eths = $config->listNodes();
    
    print FILE_LCK "health {\n";

    foreach my $ethNode (@eths) {
	
	print FILE_LCK "\tinterface " . $ethNode . " {\n";
	
	my $option = $config->returnValue("$ethNode failure-count");
	if (defined $option) {
	    print FILE_LCK "\t\tfailure-ct  " . $option . "\n";
	}
	
	$option = $config->returnValue("$ethNode ping");
	if (defined $option) {
	    print FILE_LCK "\t\ttarget  " . $option . "\n";
	    $valid = "true";
	}
	
	$option = $config->returnValue("$ethNode resp-time");
	if (defined $option) {
	    print FILE_LCK "\t\tping-resp  " . $option*1000 . "\n";
	}
	
	$option = $config->returnValue("$ethNode success-count");
	if (defined $option) {
	    print FILE_LCK "\t\tsuccess-ct  " . $option . "\n";
	}

	$option = $config->returnValue("$ethNode nexthop");
	if (defined $option) {
	    print FILE_LCK "\t\tnexthop  " . $option . "\n";
	}
	else {
	    print "nexthop must be specified\n";
	    exit 1;
	}
	print FILE_LCK "\t}\n";
    }
    print FILE_LCK "}\n\n";

    if ($valid eq "false") {
	print "A valid WAN load-balance configuration requires an interface with a ping target\n";
    }
    return $valid;
}

sub write_rules {
    my $config = new Vyatta::Config;

    my $valid = "false";

    $config->setLevel('load-balancing wan rule');
    my @rules = $config->listNodes();
    
    #destination
    foreach my $rule (@rules) {
	print FILE_LCK "rule " . $rule . " {\n";
	
	$config->setLevel('load-balancing wan rule');

	if ($config->exists("$rule exclude")) {
	    $valid = "true";
	    print FILE_LCK "\texclude\n";
	}

	if ($config->exists("$rule failover")) {
	    print FILE_LCK "\tfailover\n";
	}

	if ($config->exists("$rule failover") && $config->exists("$rule exclude")) {
	    print "failover cannot be configured with exclude\n";
	    exit 1;
	}

	my $protocol = $config->returnValue("$rule protocol");
	if (defined $protocol) {
	    print FILE_LCK "\tprotocol " . $protocol . "\n"
	}
	else {
	    $protocol = "";
	}

	#destination
	print FILE_LCK "\tdestination {\n";
	my $daddr = $config->returnValue("$rule destination address");
	if (defined $daddr) {
	    if (Vyatta::TypeChecker::validate_iptables4_addr($daddr) eq "1") {
		print FILE_LCK "\t\taddress \"" . $daddr . "\"\n";
	    }
	    else {
		print "Error in destination address configuration\n";
		exit 1;
	    }
	}

	my $option = $config->returnValue("$rule destination port");
	if (defined $option) {
	    my $can_use_port;
	    my $port_str;
	    my $port_err;

	    if ($protocol eq "tcp" || $protocol eq "udp") {
		$can_use_port = "yes";
	    }
	    ($port_str, $port_err) = Vyatta::Misc::getPortRuleString($option, $can_use_port, "d", $protocol);
	    if (defined $port_str) {
		print FILE_LCK "\t\tport-ipt \"" . $port_str . "\"\n";
	    }
	    else {
		print $port_err;
		exit 1;
	    }
	}

	print FILE_LCK "\t}\n";

	#source
	$config->setLevel('load-balancing wan rule');


	print FILE_LCK "\tsource {\n";
	my $saddr = $config->returnValue("$rule source address");
	if (defined $saddr) {
	    if (Vyatta::TypeChecker::validate_iptables4_addr($saddr) eq "1") {
		print FILE_LCK "\t\taddress \"" . $saddr . "\"\n";
	    }
	    else {
		print "Error in source address configuration\n";
		exit 1;
	    }
	}

	$option = $config->returnValue("$rule source port");
	if (defined $option) {
	    my $can_use_port;
	    my $port_str;
	    my $port_err;

	    if ($protocol eq "tcp" || $protocol eq "udp") {
		$can_use_port = "yes";
	    }
	    ($port_str, $port_err) = Vyatta::Misc::getPortRuleString($option, $can_use_port, "d", $protocol);
	    if (defined $port_str) {
		print FILE_LCK "\t\tport-ipt \"" . $port_str . "\"\n";
	    }
	    else {
		print $port_err;
		exit 1;
	    }
	}
	print FILE_LCK "\t}\n";

	#inbound-interface
	$option = $config->returnValue("$rule inbound-interface");
	if (defined $option) {
	    print FILE_LCK "\tinbound-interface " . $option . "\n"
	}
	else {
	    print "inbound-interface must be specified\n";
	    exit 1;
	}

	#interface
	$config->setLevel("load-balancing wan rule $rule interface");
	my @eths = $config->listNodes();
	
	foreach my $ethNode (@eths) {

	    $valid = "true";

	    print FILE_LCK "\tinterface " . $ethNode . " {\n";
	    
	    $option = $config->returnValue("$ethNode weight");
	    if (defined $option) {
		print FILE_LCK "\t\tweight  " . $option . "\n";
	    }
	    print FILE_LCK "\t}\n";
	}
	print FILE_LCK "}\n";
    }

    if ($valid eq "false") {
	print "At least one rule with interface must be defined for WAN load balancing to be active\n";
	#allow this configuration, just generate the warning
	return "true";
    }
    return $valid;
}



####main
my $conf_file = '/var/load-balance/wlb.conf';
my $conf_lck_file = '/var/load-balance/wlb.conf.lck';

#open file
open(FILE, "<$conf_file") or die "Can't open wlb config file"; 
open(FILE_LCK, "+>$conf_lck_file") or die "Can't open wlb lock file";

my $success = write_health();
if ($success eq "false") {
    exit 1;
}

$success = write_rules();
if ($success eq "false") {
    exit 1;
}

close FILE;
close FILE_LCK;

copy ($conf_lck_file,$conf_file);
unlink($conf_lck_file);


#finally kick the process
system "/opt/vyatta/sbin/vyatta-wanloadbalance.init restart $conf_file 2>/dev/null";

exit 0;