Fill SNMP plugin with life

Makefile

@@ -15,7 +15,7 @@ CXXFLAGS =	-std=c++11 -DBOOST_DATE_TIME_POSIX_TIME_STD_CONFIG -DBOOST_NETWORK_EN
 
 LIBS = -L../deps/mosquitto_build/lib -L$(DCDBDEPLOYPATH)/lib/ -ldl -lmosquitto -lboost_system -lboost_thread -lboost_log_setup -lboost_log -lpthread -lcrypto -lssl -lcppnetlib-server-parsers -lcppnetlib-uri -rdynamic
 OBJS = src/dcdbpusher.o src/Configuration.o src/Sensor.o src/MQTTPusher.o src/HttpsServer.o
-PLUGINS_BASE = libdcdbplugin_pdu libdcdbplugin_sysfs libdcdbplugin_ipmi libdcdbplugin_bacnet
+PLUGINS_BASE = libdcdbplugin_pdu libdcdbplugin_sysfs libdcdbplugin_ipmi libdcdbplugin_bacnet libdcdbplugin_snmp
 
 ifeq ($(OS),Darwin)
 	BACNET_PORT = bsd
@@ -77,3 +77,6 @@ libdcdbplugin_pdu.$(LIBEXT): src/Sensor.o src/sensors/pdu/PDUSensor.o src/sensor
 	
 libdcdbplugin_bacnet.$(LIBEXT): src/Sensor.o src/sensors/bacnet/BACnetSensor.o src/sensors/bacnet/BACnetClient.o src/sensors/bacnet/BACnetConfigurator.o
 	$(CXX) $(LIBFLAGS)$@ -o $@ $^ -L$(DCDBDEPLOYPATH)/lib/ -lboost_log -lboost_system -lbacnet
+	
+libdcdbplugin_snmp.$(LIBEXT): src/Sensor.o src/sensors/snmp/SNMPSensor.o src/sensors/snmp/SNMPConnection.o src/sensors/snmp/SNMPConfigurator.o
+	$(CXX) $(LIBFLAGS)$@ -o $@ $^ -L$(DCDBDEPLOYPATH)/lib/ -lboost_log -lboost_system -lnetsnmp -lnetsnmpagent

config/global.conf

@@ -26,6 +26,11 @@ restAPI {
 
 plugins {
 
+	plugin snmp {
+		path	./
+		config
+	}
+
 	plugin sysfs {
 		path	./
 		config

config/snmp.conf

+global {
+	mqttprefix		/00112233445566778899AABBCC
+}
+
+templates {
+	sensor temp1 {
+		interval	1000
+		minValues	3
+	}
+}
+
+; Connections contains a list of connections
+; So far, we only support "Agent" mode in which we connect to a
+; SNMP agent and issue GET commands to read the data.
+
+connections {
+	; Each connection is identified by a unique name. However, this
+	; name is only useful when we print error messages.
+	connection name1	{
+		Type        Agent									; Type of connection
+		Host        HostNameOfSNMPAgent						; Hostname of the SNMP agent
+		Port        161										; Port of the SNMP agent
+		Community   public									; SNMP community string
+		OIDPrefix   1.3.6.1.4.1.1000						; When querying OIDs, we'll 
+				                                  			; always use this prefix
+		mqttPart	BB										; When generating MQTT topics,
+				                                   		 	; we'll append this part to
+				                                   		 	; the prefix
+
+		sensor name1	{
+			OID			100.1                               ; OID of the sensor
+			mqttsuffix	0001                                ; MQTT suffix of the sensor
+			interval	1000                                ; Read sensor every 1000ms
+		}
+
+		sensor name2	{
+			OID			100.2
+			mqttsuffix	0002
+			default		temp1
+		}
+	}
+
+	connection name2
+	{
+		Type        Agent
+		Host        HostNameOfSNMPAgent2
+		Port        161
+		Community   public
+		OIDPrefix   1.3.6.1.4.1.1000.15
+		mqttPart	CC
+
+		sensor name1	{
+			OID			3
+			mqttsuffix	0017
+			interval	5000
+		}
+	}
+}

src/HttpsServer.cpp

@@ -65,7 +65,8 @@ void HttpsServer::requestHandler::operator()(server::request const &request, ser
 	}
 
 	//split query part into the individual queries (key-value pairs)
-	{
+	{	//do not remove the enclosing brackets
+		//need to encapsulate this code block to keep queryStrs local
 		std::vector<std::string> queryStrs;
 		boost::split(queryStrs, query, boost::is_any_of(";"), boost::token_compress_on);
 		for(auto& key : queryStrs) {

src/sensors/snmp/SNMPConfigurator.cpp

@@ -9,22 +9,137 @@
 
 #include <boost/foreach.hpp>
 #include <boost/property_tree/info_parser.hpp>
+#include <boost/algorithm/string.hpp>
 
 SNMPConfigurator::SNMPConfigurator() {
-	// TODO Auto-generated constructor stub
-
+	/* Initialize SNMP library */
+	init_snmp("dcdbpusher_SNMPplugin");
 }
 
-SNMPConfigurator::~SNMPConfigurator() {
-	// TODO Auto-generated destructor stub
-}
+SNMPConfigurator::~SNMPConfigurator() {}
 
 bool SNMPConfigurator::readConfig(std::string cfgPath) {
-	//TODO
+	Configurator::readConfig(cfgPath);
+	boost::property_tree::iptree cfg;
+	boost::property_tree::read_info(cfgPath, cfg);
+
+	std::string mqttPartConnection;
+
+	//read global variables (if present overwrite those from global.conf)
+	BOOST_FOREACH(boost::property_tree::iptree::value_type &global, cfg.get_child("global")) {
+		if (boost::iequals(global.first, "mqttprefix")) {
+			_mqttPrefix = global.second.data();
+			if (_mqttPrefix[_mqttPrefix.length()-1] != '/') {
+				_mqttPrefix.append("/");
+			}
+			LOG(debug) << "  Using own MQTT-Prefix " << _mqttPrefix;
+		} else if (boost::iequals(global.first, "cacheInterval")) {
+			_cacheInterval = stoul(global.second.data());
+			LOG(debug) << "  Using own caching interval " << _cacheInterval << " [s]";
+			_cacheInterval *= 1000;
+		} else {
+			LOG(error) << "  Value \"" << global.first << "\" not recognized. Omitting...";
+		}
+	}
+
+	//read template sensors
+	BOOST_FOREACH(boost::property_tree::iptree::value_type &sensor, cfg.get_child("templates")) {
+		if (boost::iequals(sensor.first, "sensor")) {
+			LOG(debug) << "Template Sensor \"" << sensor.second.data() << "\"";
+			if (!sensor.second.empty()) {
+				SNMPSensor snmpSensor(sensor.second.data());
+				if(readSensor(snmpSensor, sensor.second)) {
+					_templateSensors.insert(sensorMap_t::value_type(snmpSensor.getName(), snmpSensor));
+				} else {
+					LOG(warning) << "Template sensor \"" << sensor.second.data() << "\" has bad values! Ignoring...";
+				}
+			}
+		}
+	}
+
+	BOOST_FOREACH(boost::property_tree::iptree::value_type &connection, cfg.get_child("connections")) {
+		if (boost::iequals(connection.first, ("connection"))) {
+			LOG(debug) << "Connection " << connection.second.data();
+			_connections.push_back(SNMPConnection());
+			SNMPConnection &conn = _connections.back();
+
+			if (!connection.second.empty()) {
+				BOOST_FOREACH(boost::property_tree::iptree::value_type &c, connection.second) {
+					if (boost::iequals(c.first, "Type")) {
+						//TODO	would be relevant if we would support more than just agent mode...
+						//		at the moment we just ignore it, as it can be only "Agent" anyways
+					} else if (boost::iequals(c.first, "Host")) {
+						conn.setHost(c.second.data());
+					} else if (boost::iequals(c.first, "Port")) {
+						conn.setPort(stoi(c.second.data()));
+					} else if (boost::iequals(c.first, "Community")) {
+						conn.setSNMPCommunity(c.second.data());
+					} else if (boost::iequals(c.first, "OIDPrefix")) {
+						conn.setOIDPrefix(c.second.data());
+					} else if (boost::iequals(c.first, "mqttPart")) {
+						mqttPartConnection = c.second.data();
+						if (mqttPartConnection[mqttPartConnection.length()-1] != '/') {
+							mqttPartConnection.append("/");
+						}
+					} else if (boost::iequals(c.first, "sensor")) {
+						LOG(debug) << "Sensor \"" << c.second.data() << "\"";
+						if (!c.second.empty()) {
+							std::string name = connection.second.data() + "_" + c.second.data();
+							SNMPSensor * snmpSensor = new SNMPSensor(name);
+
+							//first check if default sensor is given
+							boost::optional<boost::property_tree::iptree&> defaultC = c.second.get_child_optional("default");
+							if(defaultC) {
+								LOG(debug) << "  Using \"" << defaultC.get().data() << "\" as default.";
+								sensorMap_t::iterator it = _templateSensors.find(defaultC.get().data());
+								if(it != _templateSensors.end()) {
+									*snmpSensor = it->second;
+									snmpSensor->setName(name);
+								} else {
+									LOG(warning) << "  Template sensor \"" << defaultC.get().data() << "\" not found! Using standard values.";
+								}
+							}
+
+							snmpSensor->setMqtt(_mqttPrefix + mqttPartConnection);
+							snmpSensor->setConnection(&conn);
+
+							//read remaining values
+							if(readSensor(*snmpSensor, c.second)) {
+								_sensors.push_back(snmpSensor);
+							} else {
+								LOG(warning) << "  Sensor \"" << c.second.data() << "\" has bad values! Ignoring..." << std::endl;
+							}
+						}
+					}
+				}
+			}
+			conn.init();
+		}
+	}
 	return true;
 }
 
 bool SNMPConfigurator::readSensor(SNMPSensor& sensor, boost::property_tree::iptree& config) {
-	//TODO
+	BOOST_FOREACH(boost::property_tree::iptree::value_type &val, config) {
+		if (boost::iequals(val.first, "interval")) {
+			sensor.setInterval(stoull(val.second.data()));
+		} else if (boost::iequals(val.first, "mqttsuffix")) {
+			sensor.setMqtt(sensor.getMqtt() + val.second.data());
+		} else if (boost::iequals(val.first, "minValues")) {
+			sensor.setMinValues(stoull(val.second.data()));
+		} else if (boost::iequals(val.first, "OID")) {
+			sensor.setOID(sensor.getConnection()->getOIDPrefix() + "." + val.second.data());
+		} else if (boost::iequals(val.first, "default")) {
+			//avoid unnecessary "Value not recognized" message
+		} else {
+			LOG(warning) << "  Value \"" << val.first << "\" not recognized. Omitting...";
+		}
+	}
+	sensor.setCacheInterval(_cacheInterval);
+
+	LOG(debug) << "  MQTT     : " << sensor.getMqtt();
+	LOG(debug) << "  Interval : " << sensor.getInterval();
+	LOG(debug) << "  minValues: " << sensor.getMinValues();
+	LOG(debug) << "  OID      : " << sensor.getOIDString();
 	return true;
 }

src/sensors/snmp/SNMPConfigurator.h

@@ -16,10 +16,12 @@
 #include <string>
 #include <vector>
 #include <map>
+#include <list>
 #include <boost/property_tree/ptree.hpp>
 
 class SNMPConfigurator : public Configurator {
 
+	typedef std::list<SNMPConnection> connectionList_t;
 	typedef std::map<std::string, SNMPSensor> sensorMap_t;
 
 public:
@@ -35,7 +37,10 @@ public:
 
 	//Overwrite from Configurator
 	bool reReadConfig() {
-		//TODO
+		for (auto s : _sensors) {
+			s->stopPolling();
+		}
+		_connections.clear();
 		_templateSensors.clear();
 		return Configurator::reReadConfig();
 	}
@@ -48,7 +53,8 @@ private:
 	 */
 	bool readSensor(SNMPSensor& sensor, boost::property_tree::iptree& config);
 
-	sensorMap_t 	 	 _templateSensors;
+	connectionList_t	_connections;
+	sensorMap_t			_templateSensors;
 };
 
 extern "C" Configurator* create() {

src/sensors/snmp/SNMPConnection.cpp

@@ -7,13 +7,24 @@
 
 #include "SNMPConnection.h"
 
+#include <string>
+
 SNMPConnection::SNMPConnection() {
-	// TODO Auto-generated constructor stub
+	_snmpCommunity	= "";
+	_oidPrefix		= "";
+	_host			= "";
+	_port			= 0;
 
+	_snmpSession.community_len = 0;
+	_strand = NULL;
 }
 
 SNMPConnection::~SNMPConnection() {
-	// TODO Auto-generated destructor stub
+	if (_snmpSession.community_len) {
+		free(_snmpSession.peername);
+		free(_snmpSession.community);
+		_snmpSession.community_len = 0;
+	}
 }
 
 void SNMPConnection::initializeStrand(boost::asio::io_service& io) {
@@ -21,3 +32,62 @@ void SNMPConnection::initializeStrand(boost::asio::io_service& io) {
 		_strand = new boost::asio::io_service::strand(io);
 	}
 }
+
+void SNMPConnection::init() {
+	snmp_sess_init(&_snmpSession);
+	_snmpSession.version = SNMP_VERSION_2c;
+	_snmpSession.peername = strdup(_host.c_str());
+	_snmpSession.community = (u_char*) strdup(_snmpCommunity.c_str());
+	_snmpSession.community_len = _snmpCommunity.length();
+}
+
+uint64_t SNMPConnection::issueGet(oid* OID, size_t OIDLen) {
+	struct snmp_session* ss;
+	struct snmp_pdu *pdu, *response;
+	struct variable_list *vp;
+	int status;
+	uint64_t ret = 0;
+
+	ss = snmp_open(&_snmpSession);
+
+	if (!ss) {
+		throw std::runtime_error("Could not open SNMP Session!");
+	}
+
+	pdu = snmp_pdu_create(SNMP_MSG_GET);
+
+	snmp_add_null_var(pdu, OID, OIDLen);
+
+	status = snmp_synch_response(ss, pdu, &response);
+
+	if (status == STAT_SUCCESS && response->errstat == SNMP_ERR_NOERROR) {
+		vp = response->variables;
+		if (vp) {
+			if (vp->type == ASN_INTEGER) {
+				/* Trigger callback in SNMPPusher.cpp */
+				ret = *vp->val.integer;
+			}
+			else if (vp->type == 0x43) { /* Timeticks: No idea why there is no definition for this in the libray */
+				/* Trigger callback in SNMPPusher.cpp */
+				ret = *vp->val.integer;
+			}
+			else {
+				LOG(warning) << "Non-Integer and non-Timetick SNMP data received (type=" << std::to_string((int)vp->type) << "):";
+				char buf[1024];
+				while (vp) {
+					snprint_variable(buf, sizeof(buf), vp->name, vp->name_length, vp);
+					LOG(warning) << ss->peername << ": " << buf;
+					vp = vp->next_variable;
+				}
+			}
+		}
+	} else {
+		throw std::runtime_error("Request failed!");
+	}
+
+	if (response) {
+		snmp_free_pdu(response);
+	}
+	snmp_close(ss);
+	return ret;
+}

src/sensors/snmp/SNMPConnection.h

@@ -12,6 +12,7 @@
 
 #include <net-snmp/net-snmp-config.h>
 #include <net-snmp/net-snmp-includes.h>
+#include <boost/asio.hpp>
 
 class SNMPConnection {
 
@@ -19,13 +20,72 @@ public:
 	SNMPConnection();
 	virtual ~SNMPConnection();
 
+	void setSNMPCommunity(const std::string& community) {
+		_snmpCommunity = community;
+	}
+
+	const std::string& getSNMPCommunity() const {
+		return _snmpCommunity;
+	}
+
+	void setOIDPrefix(const std::string& oidPrefix) {
+		/* Ensure that the oidPrefix does not contain a trailing . */
+		_oidPrefix = oidPrefix;
+		if (_oidPrefix.length() > 0) {
+			if (_oidPrefix.at(_oidPrefix.length() - 1) == '.') {
+				_oidPrefix.resize(_oidPrefix.size() - 1);
+			}
+		}
+	}
+
+	const std::string& getOIDPrefix() const {
+		return _oidPrefix;
+	}
+
+	void setHost(const std::string& host) {
+		_host = host;
+	}
+
+	const std::string& getHost() const {
+		return _host;
+	}
+
+	void setPort(int port) {
+		_port = port;
+	}
+
+	int getPort() const {
+		return _port;
+	}
+
 	void initializeStrand(boost::asio::io_service& io);
 
 	boost::asio::io_service::strand* getStrand() const {
 		return _strand;
 	}
 
+	/**
+	 * Initializes the connection. Must be called once before the connection can be used
+	 */
+	void init();
+
+	/**
+	 * Issues a get request to _host for the value specified by the OID.
+	 *
+	 * @param OID		Pointer to the OID buffer which identifies the value to request
+	 * @param OIDLen	Lenght of the OID buffer
+	 *
+	 * @return		The requested value
+	 */
+	uint64_t issueGet(oid* OID, size_t OIDLen);
+
 private:
+	std::string _snmpCommunity;
+	std::string _oidPrefix;
+	std::string	_host;
+	int			_port;
+	struct snmp_session	_snmpSession;
+
 	boost::asio::io_service::strand*	_strand;
 	boost::log::sources::severity_logger<boost::log::trivial::severity_level> lg;
 };

src/sensors/snmp/SNMPSensor.cpp

@@ -10,27 +10,30 @@
 
 SNMPSensor::SNMPSensor(const std::string& name) :
 	Sensor(name) {
-	// TODO Auto-generated constructor stub
+	memset(_oid, 0x0, sizeof(oid) * MAX_OID_LEN);
+	_oidLen = 0;
 	_connection = NULL;
 }
 
 SNMPSensor::~SNMPSensor() {
-	// TODO Auto-generated destructor stub
+	// Nothing to do
 }
 
 void SNMPSensor::read() {
 	reading_t reading;
-	char buf[1024];
-
 	reading.timestamp = getTimestamp();
 
-	//TODO
-
+	try {
+		reading.value = _connection->issueGet(_oid, _oidLen);
+		storeReading(reading);
+		_latestValue.value		= reading.value;
+		_latestValue.timestamp	= reading.timestamp;
 #ifdef DEBUG
 		LOG(debug) << _name << ": \"" << reading.value << "\"";
 #endif
+	} catch (const std::exception& e) {
+		LOG(error) << _name << " could not read value: " << e.what();
 	}
-	storeReading(reading);
 }
 
 void SNMPSensor::readAsync() {
@@ -59,8 +62,6 @@ void SNMPSensor::startPolling() {
 		return;
 	}
 
-	//TODO
-
 	if (_connection) {
 		_keepRunning = 1;
 		_timer->async_wait(_connection->getStrand()->wrap(std::bind(&SNMPSensor::readAsync, this)));
@@ -77,8 +78,5 @@ void SNMPSensor::stopPolling() {
 	_timer->cancel();
 	//wait until read() finished before closing _file
 	_timer->wait();
-
-	//TODO
-
 	LOG(info) << "Sensor " << _name << " stopped.";
 }

src/sensors/snmp/SNMPSensor.h

@@ -9,6 +9,7 @@
 #define SNMPSENSOR_H_
 
 #include "../../Sensor.h"
+#include "SNMPConnection.h"
 
 #include <net-snmp/net-snmp-config.h>
 #include <net-snmp/net-snmp-includes.h>