<?php

function sync_package_snort() {
	global $config, $g;
	exec("mkdir -p /usr/local/etc/snort");
	exec("mkdir -p /var/log/snort");
	exec("/bin/cp /usr/local/etc/snort/unicode.map-sample /usr/local/etc/snort/unicode.map");
	exec("cp /usr/local/etc/snort/classification.config-sample /usr/local/etc/snort/classification.config");
	exec("cp /usr/local/etc/snort/gen-msg.map-sample /usr/local/etc/snort/gen-msg.map");
	exec("cp /usr/local/etc/snort/generators-sample /usr/local/etc/snort/generators");
	exec("cp /usr/local/etc/snort/reference.config-sample /usr/local/etc/snort/reference.config");
	exec("cp /usr/local/etc/snort/sid-msg.map-sample /usr/local/etc/snort/sid-msg.map");
	exec("cp /usr/local/etc/snort/sid-sample /usr/local/etc/snort/sid");
	exec("cp /usr/local/etc/snort/threshold.conf-sample /usr/local/etc/snort/threshold.conf");
	exec("cp /usr/local/etc/snort/unicode.map-sample /usr/local/etc/snort/unicode.map");
	exec("rm -f /usr/local/etc/rc.d/snort");

	$first = 0;
	/* if list */
	$iflist = array("lan" => "LAN");
	for ($i = 1; isset($config['interfaces']['opt' . $i]); $i++)
		$iflist['opt' . $i] = "opt{$i}";
	$whitelist = fopen("/var/db/whitelist","w");
	if(!$whitelist) {
		log_error("Cannot open whitelist for /var/db/writing.");
		exit;
	}
	foreach($iflist as $if) {
		/* XXX: write out if subnet */
	}
	fclose($whitelist);
	foreach($_POST['interface_array'] as $iface) {
		$if = convert_friendly_interface_to_real_interface_name($iface);
		if($if) {
			$ifaces_final .= " -i " . $if;
			$first = 1;
		}
	}
	$start  = "/bin/mkdir -p /var/log/snort;snort -c /usr/local/etc/snort/snort.conf -l /var/log/snort " . $ifaces_final . " -D";
	$start .= ";snort2c -s -w /var/db/whitelist -a /var/log/snort/alert";
	write_rcfile(array(
			"file" => "snort.sh",
			"start" => $start,
			"stop" => "/usr/bin/killall snort; killall snort2c"
		)
	);

	create_snort_conf();

	start_service("snort");
}

function create_snort_conf() {
	/* write out snort.conf */
	$snort_conf = generate_snort_conf();
	$conf = fopen("/usr/local/etc/snort/snort.conf","w");
	if(!$conf) {
		log_error("Could not open /usr/local/etc/snort/snort.conf for writing.");
		exit;
	}
	fwrite($conf, $snort_conf);
	fclose($conf);
}

function generate_snort_conf() {
	global $config, $g, $config;

	/* obtain external interface */
	/* XXX: make multi wan friendly */
	$snort_ext_int = $config['installedpackages']['snort']['config'][0]['interface_array'][0];

	/* open snort2c's whitelist for writing */
	$whitelist = fopen("/var/db/whitelist", "w");
	if(!$whitelist) {
		log_error("Could not open /var/db/whitelist for writing.");
		exit;
	}

	/* build an interface array list */
	$int_array = array('lan');
	for ($j = 1; isset ($config['interfaces']['opt' . $j]); $j++)
		if(isset($config['interfaces']['opt' . $j]['enable']))
			if(!$config['interfaces']['opt' . $j]['gateway'])
				$int_array[] = "opt{$j}";

	/* if user has defined a custom ssh port, use it */
	if($config['system']['ssh']['port'])
		$ssh_port = $config['system']['ssh']['port'];
	else
		$ssh_port = "22";

	/* iterate through interface list and write out whitelist items
	 * and also compile a home_net list for snort.
	 */
	foreach($int_array as $int) {
		/* calculate interface subnet information */
		$ifcfg = &$config['interfaces'][$int];
		$subnet = gen_subnet($ifcfg['ipaddr'], $ifcfg['subnet']);
		$subnetmask = gen_subnet_mask($ifcfg['subnet']);
		$home_net .= "{$subnet}/{$ifcfg['subnet']} ";
	}

	/* write out whitelist */
	fwrite($whitelist, $home_net);

	/* close file */
	fclose($whitelist);

	/* XXX: generate rule section dynamically from config.xml information
	 */
	$selected_rules_sections = "";
	$enabled_rulesets = $config['installedpackages']['snort']['config'][0]['rulesets'];
	if($enabled_rulesets)
		$enabled_rulesets_array = split("\|\|", $enabled_rulesets);

	foreach($enabled_rulesets_array as $enabled_item)
		$selected_rules_sections  .= "include \$RULE_PATH/{$enabled_item}\n";

	/* build snort configuration file */
	$snort_conf = <<<EOD

var AIM_SERVERS [64.12.24.0/24,64.12.25.0/24,64.12.26.14/24,64.12.28.0/24,64.12.29.0/24,64.12.161.0/24,64.12.163.0/24,205.188.5.0/24,205.188.9.0/24]
var HTTP_PORTS 80
var SHELLCODE_PORTS !\$HTTP_PORTS
var ORACLE_PORTS 1521
var HOME_NET {$home_net}
var TELNET_SERVERS \$HOME_NET
var SQL_SERVERS \$HOME_NET
var HTTP_SERVERS \$HOME_NET
var SMTP_SERVERS \$HOME_NET
var DNS_SERVERS \$HOME_NET
var EXTERNAL_NET !\$HOME_NET
var SSH_PORTS {$ssh_port}
var RULE_PATH /usr/local/etc/snort/rules

# Use lower memory models
config detection: search-method lowmem

#Output plugins
#output database: alert
output alert_syslog: LOG_AUTH LOG_ALERT LOG_CONS LOG_NDELAY LOG_PERROR LOG_PID

output alert_unified: filename alert

#Flow and stream
preprocessor flow: stats_interval 0 hash 2
preprocessor frag2
preprocessor stream4: disable_evasion_alerts,detect_scans

preprocessor stream4_reassemble: both, ports all

#XLink2State mini proc
#preprocessor xlink2state: ports { 25 691 }

#HTTP Inspect
preprocessor http_inspect: global iis_unicode_map unicode.map 1252

preprocessor http_inspect_server: server default \
                        ports  { 80 8080 3128 }  \
                        no_alerts \
                        non_strict \
                        non_rfc_char  { 0x00 }  \
                        flow_depth 0  \
                        apache_whitespace yes \
                        directory no \
                        iis_backslash no \
                        u_encode yes \
                        ascii no \
                        chunk_length 500000 \
                        bare_byte yes \
                        double_decode yes \
                        iis_unicode yes \
                        iis_delimiter yes \
                        multi_slash no

#Other preprocs
preprocessor rpc_decode: 111 32771
preprocessor bo
preprocessor telnet_decode

#Flow Portscan
preprocessor flow-portscan: \
        talker-sliding-scale-factor 0.50 \
        talker-fixed-threshold 30 \
        talker-sliding-threshold 30 \
        talker-sliding-window 20 \
        talker-fixed-window 30 \
        scoreboard-rows-talker 30000 \
        server-watchnet \$HOME_NET \
        server-ignore-limit 200 \
        server-rows 65535 \
        server-learning-time 14400 \
        server-scanner-limit 4 \
        scanner-sliding-window 20 \
        scanner-sliding-scale-factor 0.50 \
        scanner-fixed-threshold 15 \
        scanner-sliding-threshold 40 \
        scanner-fixed-window 15 \
        scoreboard-rows-scanner 30000 \
        alert-mode once \
        output-mode msg \
        tcp-penalties on


#Required files
include classification.config
include reference.config

#Rulesets, all optional
{$selected_rules_sections}

EOD;

	return $snort_conf;
}

?>