negate_hosts_by_cidr.js

var negateHostsByCIDR = function () {
    // Generate a list of hostname[string_addr] targets which do not exist in CIDR range
    //
    // Created by: Matt Burch
    // Usage: negateHostsByCIDR('x.x.x.x/x') or negateHostsByCIDR('x.x.x.x/x','y.y.y.y/y');
    //
    var nets = Array.prototype.slice.call(arguments, 0);
    var hosts = Hosts.find({
        project_id: Session.get('projectId')
    }).fetch();
    var hostip = {};

    function dec2Bin(octet, cidr) {
        var pad = '00000000';
        var bin = parseInt(octet[0], 10).toString(2);
        var bincidr = (bin.length >= pad.length ? bin : pad.slice(0, pad.length - bin.length) + bin);

        for (i = 1; i <= octet.length; i++) {
            bin = parseInt(octet[i], 10).toString(2);
            bincidr += (bin.length >= pad.length ? bin : pad.slice(0, pad.length - bin.length) + bin);
        }

        return bincidr.slice(0, parseInt(cidr, 10));
    }

    hosts.forEach(function (host) {
        var ip = host.string_addr.split('.');
        hostip[dec2Bin(ip, 32)] = host.string_addr;
    });

    nets.forEach(function (cidr) {
        cidr = cidr.split('/');
        var net = cidr[0].split('.');
        var netbin = dec2Bin(net, cidr[1]);

        for (var key in hostip) {
            if ((key.slice(0, parseInt(cidr[1], 10))) == netbin) {
                delete hostip[key];
            }
        }
    });

    for (var key in hostip) {
        console.log(hostip[key]);
    }
};