iw.js
/*
* Copyright (c) 2015 Christopher M. Baker
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
var child_process = require('child_process');
/**
* The **iw** command is used to control nl80211 radios.
*
* @static
* @category iw
*
*/
var iw = module.exports = {
exec: child_process.exec,
scan: scan
};
/**
* Returns a truthy if the network has an ssid; falsy otherwise.
*
* @private
* @static
* @category iw
* @param {object} network The scanned network object.
* @returns {string} The ssid.
*
*/
function has_ssid(network) {
return network.ssid;
}
/**
* Returns a truthy if the network has any key; falsy otherwise.
*
* @private
* @static
* @category iw
* @param {object} network The scanned network object.
* @returns {boolean} True if any key.
*
*/
function has_keys(network) {
return Object.keys(network).length !== 0;
}
/**
* A comparison function to sort networks ordered by signal strength.
*
* @private
* @static
* @category iw
* @param {object} a A scanned network object.
* @param {object} b Another scanned network object.
* @returns {number} The comparison value.
*
*/
function by_signal(a, b) {
return b.signal - a.signal;
}
/**
* Parses a scanned wireless network cell.
*
* @private
* @static
* @category iw
* @param {string} cell The section of stdout for the cell.
* @returns {object} The scanned network object.
*
*/
function parse_cell(cell) {
var parsed = { };
var match;
if ((match = cell.match(/BSS ([0-9A-Fa-f:-]{17})\(on/))) {
parsed.address = match[1].toLowerCase();
}
if ((match = cell.match(/freq: ([0-9]+)/))) {
parsed.frequency = parseInt(match[1], 10);
}
if ((match = cell.match(/signal: (-?[0-9.]+) dBm/))) {
parsed.signal = parseFloat(match[1]);
}
if ((match = cell.match(/last seen: ([0-9]+) ms ago/))) {
parsed.lastSeenMs = parseInt(match[1], 10);
}
if ((match = cell.match(/SSID: \\x00/))) {
delete parsed.ssid;
}
else if ((match = cell.match(/SSID: ([^\n]*)/))) {
parsed.ssid = match[1];
}
if ((match = cell.match(/DS Parameter set: channel ([0-9]+)/))) {
parsed.channel = parseInt(match[1], 10);
}
else if ((match = cell.match(/\* primary channel: ([0-9]+)/))) {
parsed.channel = parseInt(match[1], 10);
}
if ((match = cell.match(/RSN:[\s*]+Version: 1/))) {
parsed.security = 'wpa2';
}
else if ((match = cell.match(/WPA:[\s*]+Version: 1/))) {
parsed.security = 'wpa';
}
else if ((match = cell.match(/capability: ESS Privacy/))) {
parsed.security = 'wep';
}
else if ((match = cell.match(/capability: ESS/))) {
parsed.security = 'open';
}
return parsed;
}
/**
* Parses all scanned wireless network cells.
*
* @private
* @static
* @category iw
* @param {function} callback The callback function.
*
*/
function parse_scan(show_hidden, callback) {
return function(error, stdout, stderr) {
if (error) callback(error);
else
if (show_hidden) {
callback(error, stdout
.split(/(^|\n)(?=BSS )/)
.map(parse_cell)
.filter(has_keys)
.sort(by_signal));
} else {
callback(error, stdout
.split(/(^|\n)(?=BSS )/)
.map(parse_cell)
.filter(has_ssid)
.sort(by_signal));
}
};
}
/**
* The **iw scan** command is used to scan for wireless networks
* visible to a wireless interface. For convenience, the networks are
* sorted by signal strength.
*
* @static
* @category iw
* @param {string} interface The wireless network interface.
* @param {function} callback The callback function.
*/
function scan(options, callback) {
var interface, show_hidden
if (typeof options === 'string') {
var interface = options;
var show_hidden = false;
} else {
var interface = options.iface;
var show_hidden = options.show_hidden || false;
}
this.exec('iw dev ' + interface + ' scan', parse_scan(show_hidden, callback));
}