pcap-scribe/pcap_dump.js

pcap writer using libpcap

var util = require("util");
var events = require("events");
var binding = require("./build/Release/pcap_binding");


function PcapDumpSession(device_name, filter, buffer_size, outfile, is_monitor, number_of_packets_to_be_read) {

    this.device_name = device_name;
    this.filter = filter || "";
    this.buffer_size = buffer_size;
    this.outfile = outfile || "tmp.pcap";
    this.is_monitor = Boolean(is_monitor);
    this.packets_read = 0;
    this.number_of_packets_to_be_read = number_of_packets_to_be_read || 1;
    
    if (typeof this.buffer_size === "number" && !isNaN(this.buffer_size)) {
        this.buffer_size = Math.round(this.buffer_size);
    } else {
        this.buffer_size = 10 * 1024 * 1024; // Default buffer size is 10MB
    }

    this.device_name = this.device_name || binding.default_device();
    events.EventEmitter.call(this);
}

util.inherits(PcapDumpSession, events.EventEmitter);

exports.lib_version = binding.lib_version();

exports.findalldevs = function () {
    return binding.findalldevs();
};


PcapDumpSession.prototype.startAsyncCapture = function () {

    this.opened = true;
    binding.pcap_dump_async(
        this.device_name,
        this.filter,
        this.buffer_size,
        this.outfile,
        PcapDumpSession.prototype.on_packet.bind(this),
        this.is_monitor,
        this.number_of_packets_to_be_read,
        PcapDumpSession.prototype.on_pcap_write_complete_async.bind(this)
    );
};




PcapDumpSession.prototype.on_pcap_write_complete_async = function (err, packet_count) {
    
    if (err) {
        this.emit("pcap_write_error", err);

    } else {
        this.emit("pcap_write_complete_async", {
            "packets_read": packet_count,
            "fileName": this.outfile
        });
    }

};


PcapDumpSession.prototype.on_packet = function (packet) {
    this.emit("packet", packet);

};


exports.PcapDumpSession = PcapDumpSession;


exports.createPcapDumpSession = function (device, filter, buffer_size, path, monitor, number_of_packets) {
    return new PcapDumpSession(device, filter, buffer_size, path, monitor, number_of_packets);
};