domotz-remote-pawn/src/commands/snmp/subtrees.js

Domotz Agent

/** This file is part of Domotz Agent.
 * Copyright (C) 2016  Domotz UK LLP
 *
 * Domotz Agent is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Domotz Agent is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Domotz Agent.  If not, see <http://www.gnu.org/licenses/>.
 **/


const DEFAULT_MAX_REPETITIONS = 24;

var common = require('./../../snmp/common.js');

var snmpSubtrees = function (message, resourceLocator) {

    var snmp = resourceLocator.netSnmp;
    var cmdUtils = resourceLocator.utils.command;

    var cid = message.correlationId;
    var options = message.payload;

    var oidsMapping = cmdUtils.extractFromOptions(options, 'oids', {});
    var host = cmdUtils.extractFromOptions(options, 'host', 'localhost');
    var community = cmdUtils.extractFromOptions(options, 'community', 'public');

    var oids = common.extractOids(oidsMapping);
    var transformer = message.customTransformer ? message.customTransformer : common.transformer;

    // Adjust the default
    var maxRepetitions = options.maxRepetitions || DEFAULT_MAX_REPETITIONS;
    options.version = options.version || snmp.Version2c;
    delete options.maxRepetitions;

    return {
        execute: function (callback) {
            var response = {oids:{}};
            var waiting = {};

            for (var j = 0; j < oids.length; j++) {
                oid = oids[j];
                response.oids[oid] = {error: 'Unrecognized oid'};
            }

            var snmpSession = snmp.createSession(host, community, options);

            snmpSession.on("error", function (error) {
                var errorMessage = error.toString();
                console.error("- SNMP Subtree - (socket error) %s", errorMessage);
                snmpSession.close();
            });

            function done(oid) {

                return function (error) {
                    console.debug("MESSAGE - (%s): SNMP Subtrees => response received for oid: %s", cid, oid);
                    if (error) {
                        console.info("MESSAGE - (%s): SNMP Subtrees => error retrieving oid: %s => %s", cid, oid, error.message);
                        response.oids[oid] = {'error': error};
                    }
                    waiting[oid] = false;
                    for (var i = 0; i < oids.length; i++) {
                        if (waiting[oids[i]]) {
                            console.debug("MESSAGE - (%s): SNMP Subtrees => still waiting for oid: %s", cid, oids[i]);
                            return;
                        }
                    }
                    console.debug("MESSAGE - (%s): SNMP Subtrees => command execution concluded, yielding result: %s", cid, JSON.stringify(response));
                    snmpSession.close();
                    callback(response);
                };
            }

            function valueArrived(oid) {
                return function (varbinds) {
                    console.debug("MESSAGE - (%s): SNMP Subtrees => varbind callback invoked for oid: %s", cid, oid);
                    if (response.oids[oid].error !== undefined ) {
                        response.oids[oid] = {};
                    }
                    for (var i = 0; i < varbinds.length; i++) {
                        if (snmp.isVarbindError (varbinds[i])) {
                            console.warn ("MESSAGE - (%s): SNMP Subtrees => error retrieving oid: %s => varbind error: %s",
                                          cid, oid, snmp.varbindError(varbinds[i]));
                            response.oids[oid] = {'error': snmp.varbindError (varbinds[i])};
                            break;
                        }
                        else {
                            var sub_oid = varbinds[i].oid.substring(oid.length + 1);
                            var value = transformer(oidsMapping[oid])(varbinds[i].value);
                            console.debug("MESSAGE - (%s): SNMP value arrived: [%s].[%s]: %s", cid, oid, sub_oid, value);
                            response.oids[oid][sub_oid] = value;
                        }
                    }
                };
            }

            var oid;
            for (i = 0; i < oids.length; i++) {
                oid = oids[i];
                snmpSession.subtree(oid, maxRepetitions, valueArrived(oid), done(oid));
            }

            console.debug("MESSAGE - (%s): SNMP Subtrees => request to host %s for oids: %s", cid, host, JSON.stringify(oids));

            // Initialise structures for multi oid retrieval
            for (var i = 0; i < oids.length; i++) {
                waiting[oids[i]] = true;
            }
        },
        describe: function () {
            return "snmpSubtrees - " + host + ' - ' + JSON.stringify(oids);
        }
    };

};

module.exports.command = snmpSubtrees;