const collector = require('./netflowv9.js');
const netmask = require('netmask').Netmask;
const mysql = require('mysql');
const connection = mysql.createConnection({
    host:'localhost',
    user:'root',
    password:'',
    database:'nat'
});

const blocks = [
    // list subnets that you wish to log translations..
    new netmask('100.64.200.0/24'),
];

function logTranslation(unixTime, lanSrcAddr, lanSrcPort,
    postNatSrcAddr, postNatSrcPort, dstAddr, dstPort) {
        var query = "INSERT INTO nat_translations VALUES (" + unixTime
        + ",INET_ATON('" + lanSrcAddr + "')," + lanSrcPort + ",INET_ATON('"
        + postNatSrcAddr + "')," + postNatSrcPort + ",INET_ATON('" + dstAddr
        + "')," + dstPort + ")";
    connection.query(query, function(err, rows, fields) {
        if (err) {
           console.error('error logging translation: ' + err.stack);
        }
    });
}

collector(function(flowrecord) {
    var unixTime = flowrecord['header']['seconds'];
    var flows = flowrecord['flows'];
    for (var flow in flows) {
        var f = flows[flow];
        if (f['protocol'] != 6) {
            // only log TCP translations
            continue;
        }
        var src = f['ipv4_src_addr'];
        var isNat = false;
        for (var block in blocks) {
            if (blocks[block].contains(src)) {
                isNat = true;
                break;
            }
        }
        if (!isNat) {
            continue;
        }
        var natSrcAddr = f['postNATSourceIPv4Address'];
        if (src == natSrcAddr) {
            // when internal IP matches natted IP (anomaly I have not figured out)
            continue;
        }
        var dst = f['ipv4_dst_addr'];
        var dstPort = f['l4_dst_port'];
        var srcPort = f['l4_src_port'];
        var natSrcPort = f['postNAPTSourceTransportPort'];
        logTranslation(unixTime, src, srcPort, natSrcAddr, natSrcPort, dst, dstPort);
        //console.log(f)
    }
}).listen(3241);

process.on('SIGINT', function() {
    connection.end();
    process.exit();
});