udhcpd.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 **udhcpd** command is used to configure a dhcp server for a
* network interface.
*
* @static
* @category udhcpd
*
*/
var udhcpd = module.exports = {
exec: child_process.exec,
disable: disable,
enable: enable
};
/**
* Recursively expand `options` into `lines` with a `prefix`.
*
* @private
* @static
* @category udhcpd
* @param {object} options The dhcp server configuration.
* @param {array} lines The lines of the configuration file.
* @param {array) prefix The key prefix.
*
*/
function expand_r(options, lines, prefix) {
Object.getOwnPropertyNames(options).forEach(function(key) {
var full = prefix.concat(key);
var value = options[key];
if (Array.isArray(value)) {
value.forEach(function(val) {
lines.push(full.concat(val).join(' '));
});
}
else if (typeof(value) == 'object') {
expand_r(value, lines, full);
}
else {
lines.push(full.concat(value).join(' '));
}
});
}
/**
* Convert dhcp server configuration options to a configuration file.
*
* @private
* @static
* @category udhcpd
* @param {object} options The dhcp server configuration.
* @returns {array} The lines of the configuration file.
*
*/
function expand(options) {
var lines = [];
expand_r(options, lines, []);
return lines;
}
/**
* The **udhcpd enable** command is used to start a dhcp server on a
* specific network interface.
*
* @static
* @category udhcpd
* @param {object} options The dhcp server configuration.
* @param {function} callback The callback function.
* @returns {process} The child process.
* @example
*
* var udhcpd = require('wireless-tools/udhcpd');
*
* var options = {
* interface: 'wlan0',
* start: '192.168.10.100',
* end: '192.168.10.200',
* option: {
* router: '192.168.10.1',
* subnet: '255.255.255.0',
* dns: [ '4.4.4.4', '8.8.8.8' ]
* }
* };
*
* udhcpd.enable(options, function(err) {
* // the dhcp server was started
* });
*
*/
function enable(options, callback) {
var file = options.interface + '-udhcpd.conf';
var commands = [].concat(
'cat <<EOF >' + file + ' && udhcpd ' + file + ' && rm -f ' + file,
expand(options));
return this.exec(commands.join('\n'), callback);
}
/**
* The **udhcpd disable** command is used to stop a dhcp server on a
* specific network interface.
*
* @static
* @category udhcpd
* @param {string} interface The network interface.
* @param {function} callback The callback function.
* @returns {process} The child process.
* @example
*
* var udhcpd = require('wireless-tools/udhcpd');
*
* udhcpd.disable('wlan0', function(err) {
* // the dhcp server was stopped
* });
*
*/
function disable(interface, callback) {
var file = interface + '-udhcpd.conf';
return this.exec('kill `pgrep -f "^udhcpd ' + file + '"` || true', callback);
}