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/*_############################################################################
_##
_## SNMP4J - Snmp.java
_##
_## Copyright (C) 2003-2022 Frank Fock (SNMP4J.org)
_##
_## Licensed under the Apache License, Version 2.0 (the "License");
_## you may not use this file except in compliance with the License.
_## You may obtain a copy of the License at
_##
_## http://www.apache.org/licenses/LICENSE-2.0
_##
_## Unless required by applicable law or agreed to in writing, software
_## distributed under the License is distributed on an "AS IS" BASIS,
_## WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
_## See the License for the specific language governing permissions and
_## limitations under the License.
_##
_##########################################################################*/
package org.snmp4j;
import org.snmp4j.event.CounterEvent;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.event.ResponseListener;
import org.snmp4j.log.LogAdapter;
import org.snmp4j.log.LogFactory;
import org.snmp4j.mp.*;
import org.snmp4j.security.*;
import org.snmp4j.smi.*;
import org.snmp4j.transport.ConnectionOrientedTransportMapping;
import org.snmp4j.transport.TransportMappings;
import org.snmp4j.util.CommonTimer;
import java.io.IOException;
import java.util.*;
/**
* The {@code Snmp} class is the core of SNMP4J. It provides functions to send and receive SNMP PDUs. All SNMP PDU types
* can be send. Confirmed PDUs can be sent synchronously and asynchronously.
*
* The {@code Snmp} class is transport protocol independent. Support for a specific {@link TransportMapping} instance is
* added by calling the {@link #addTransportMapping(TransportMapping transportMapping)} method or creating a {@code
* Snmp} instance by using the non-default constructor with the corresponding transport mapping. Transport mappings are
* used for incoming and outgoing messages.
*
* To setup a default SNMP session for UDP transport and with SNMPv3 support the following code snippet can be
* used:
*
*
* Address targetAddress = GenericAddress.parse("udp:127.0.0.1/161");
* TransportMapping transport = new DefaultUdpTransportMapping();
* snmp = new Snmp(transport);
* USM usm = new USM(SecurityProtocols.getInstance(),
* new OctetString(MPv3.createLocalEngineID()), 0);
* SecurityModels.getInstance().addSecurityModel(usm);
* transport.listen();
*
*
* How a synchronous SNMPv3 message with authentication and privacy is then sent illustrates the following code
* snippet:
*
*
* // add user to the USM
* snmp.getUSM().addUser(new OctetString("MD5DES"),
* new UsmUser(new OctetString("MD5DES"),
* AuthMD5.ID,
* new OctetString("MD5DESUserAuthPassword"),
* PrivDES.ID,
* new OctetString("MD5DESUserPrivPassword")));
* // create the target
* UserTarget target = new UserTarget();
* target.setAddress(targetAddress);
* target.setRetries(1);
* target.setTimeout(5000);
* target.setVersion(SnmpConstants.version3);
* target.setSecurityLevel(SecurityLevel.AUTH_PRIV);
* target.setSecurityName(new OctetString("MD5DES"));
*
* // create the PDU
* PDU pdu = new ScopedPDU();
* pdu.add(new VariableBinding(new OID("1.3.6")));
* pdu.setType(PDU.GETNEXT);
*
* // send the PDU
* ResponseEvent response = snmp.send(pdu, target);
* // extract the response PDU (could be null if timed out)
* PDU responsePDU = response.getResponse();
* // extract the address used by the agent to send the response:
* Address peerAddress = response.getPeerAddress();
*
*
*
* An asynchronous SNMPv1 request is sent by the following code:
*
*
*
* // setting up target
* CommunityTarget target = new CommunityTarget();
* target.setCommunity(new OctetString("public"));
* target.setAddress(targetAddress);
* target.setRetries(2);
* target.setTimeout(1500);
* target.setVersion(SnmpConstants.version1);
* // creating PDU
* PDU pdu = new PDU();
* pdu.add(new VariableBinding(new OID(new int[] {1,3,6,1,2,1,1,1})));
* pdu.add(new VariableBinding(new OID(new int[] {1,3,6,1,2,1,1,2})));
* pdu.setType(PDU.GETNEXT);
* // sending request
* ResponseListener listener = new ResponseListener() {
* public void onResponse(ResponseEvent event) {
* // Always cancel async request when response has been received
* // otherwise a memory leak is created! Not canceling a request
* // immediately can be useful when sending a request to a broadcast
* // address.
* ((Snmp)event.getSource()).cancel(event.getRequest(), this);
* System.out.println("Received response PDU is: "+event.getResponse());
* }
* };
* snmp.sendPDU(pdu, target, null, listener);
*
*
* Traps (notifications) and other SNMP PDUs can be received by adding the following code to the first code snippet
* above:
*
*
* CommandResponder trapPrinter = new CommandResponder() {
* public synchronized void processPdu(CommandResponderEvent e) {
* PDU command = e.getPDU();
* if (command != null) {
* System.out.println(command.toString());
* }
* }
* };
* snmp.addCommandResponder(trapPrinter);
*
*
* @author Frank Fock
* @version 3.4.0
*/
public class Snmp implements Session, CommandResponder {
private static final LogAdapter logger = LogFactory.getLogger(Snmp.class);
private static final int DEFAULT_MAX_REQUEST_STATUS = 2;
private static final int ENGINE_ID_DISCOVERY_MAX_REQUEST_STATUS = 0;
// Message processing implementation
private MessageDispatcher messageDispatcher;
/**
* The {@code pendingRequests} table contains pending requests accessed through the key {@code PduHandle}
*/
private final Map> pendingRequests =
Collections.synchronizedMap(new HashMap<>(50));
/**
* The {@code asyncRequests} table contains pending requests accessed trough the key userObject
*/
private final Map asyncRequests = Collections.synchronizedMap(new HashMap<>(50));
// Timer for retrying pending requests
private CommonTimer timer;
// Listeners for request and trap PDUs
private List commandResponderListeners;
private TimeoutModel timeoutModel = new DefaultTimeoutModel();
// Dispatcher for notification listeners - not needed by default
private NotificationDispatcher notificationDispatcher = null;
// Default ReportHandler
private ReportHandler reportHandler = new ReportProcessor();
private final Map contextEngineIDs = Collections.synchronizedMap(new WeakHashMap<>());
private boolean contextEngineIdDiscoveryDisabled;
private CounterSupport counterSupport;
/**
* Creates a {@code Snmp} instance that uses a {@code MessageDispatcherImpl} with no message processing models and
* no security protocols (by default). You will have to add those by calling the appropriate methods on {@link
* #getMessageDispatcher()}.
*
* At least one transport mapping has to be added before {@link #listen()} is called in order to be able to send and
* receive SNMP messages.
*
* To initialize a {@code Snmp} instance created with this constructor follow this sample code:
*
* Transport transport = ...;
* Snmp snmp = new Snmp();
* SecurityProtocols.getInstance().addDefaultProtocols();
* MessageDispatcher disp = snmp.getMessageDispatcher();
* disp.addMessageProcessingModel(new MPv1());
* disp.addMessageProcessingModel(new MPv2c());
* snmp.addTransportMapping(transport);
* OctetString localEngineID = new OctetString(
* MPv3.createLocalEngineID());
* // For command generators, you may use the following code to avoid
* // engine ID clashes:
* // MPv3.createLocalEngineID(
* // new OctetString("MyUniqueID"+System.currentTimeMillis())));
* USM usm = new USM(SecurityProtocols.getInstance(), localEngineID, 0);
* disp.addMessageProcessingModel(new MPv3(usm));
* snmp.listen();
*
*/
public Snmp() {
this.messageDispatcher = new MessageDispatcherImpl();
if (SNMP4JSettings.getSnmp4jStatistics() != SNMP4JSettings.Snmp4jStatistics.none) {
counterSupport = CounterSupport.getInstance();
}
}
/**
* Interface for handling reports.
*
* @author Frank Fock
* @version 3.1.0
* @since 1.6
*/
public interface ReportHandler {
void processReport(PduHandle pduHandle, CommandResponderEvent event);
}
protected final void initMessageDispatcher() {
this.messageDispatcher.addCommandResponder(this);
this.messageDispatcher.addMessageProcessingModel(new MPv2c());
this.messageDispatcher.addMessageProcessingModel(new MPv1());
this.messageDispatcher.addMessageProcessingModel(new MPv3());
SecurityProtocols.getInstance().addDefaultProtocols();
}
/**
* Creates a {@code Snmp} instance that uses a {@code MessageDispatcherImpl} with all supported message processing
* models and the default security protocols for dispatching.
*
* To initialize a {@code Snmp} instance created with this constructor follow this sample code:
*
* Transport transport = ...;
* Snmp snmp = new Snmp(transport);
* OctetString localEngineID =
* new OctetString(snmp.getMPv3().getLocalEngineID());
* USM usm = new USM(SecurityProtocols.getInstance(), localEngineID, 0);
* SecurityModels.getInstance().addSecurityModel(usm);
* snmp.listen();
*
*
* @param transportMapping
* TransportMapping the initial {@code TransportMapping}. You can add more or remove the same later.
*/
public Snmp(TransportMapping transportMapping) {
this();
initMessageDispatcher();
if (transportMapping != null) {
addTransportMapping(transportMapping);
}
}
/**
* Creates a {@code Snmp} instance by supplying a {@code MessageDispatcher} and a {@code TransportMapping}.
*
* As of version 1.1, the supplied message dispatcher is not altered in terms of adding any message processing
* models to it. This has to be done now outside the Snmp class.
*
* To initialize a {@code Snmp} instance created with this constructor follow this sample code:
*
* Transport transport = ...;
* SecurityProtocols.getInstance().addDefaultProtocols();
* MessageDispatcher disp = new MessageDispatcherImpl();
* disp.addMessageProcessingModel(new MPv1());
* disp.addMessageProcessingModel(new MPv2c());
* Snmp snmp = new Snmp(disp, transport);
* OctetString localEngineID = new OctetString(
* MPv3.createLocalEngineID());
* // For command generators, you may use the following code to avoid
* // engine ID clashes:
* // MPv3.createLocalEngineID(
* // new OctetString("MyUniqueID"+System.currentTimeMillis())));
* USM usm = new USM(SecurityProtocols.getInstance(), localEngineID, 0);
* disp.addMessageProcessingModel(new MPv3(usm));
* snmp.listen();
*
*
* @param messageDispatcher
* a {@code MessageDispatcher} instance that will be used to dispatch incoming and outgoing messages.
* @param transportMapping
* the initial {@code TransportMapping}, which may be {@code null}. You can add or remove transport mappings
* later using {@link #addTransportMapping} and {@link #removeTransportMapping} respectively.
*/
public Snmp(MessageDispatcher messageDispatcher,
TransportMapping transportMapping) {
this.messageDispatcher = messageDispatcher;
this.messageDispatcher.addCommandResponder(this);
if (transportMapping != null) {
addTransportMapping(transportMapping);
}
if (SNMP4JSettings.getSnmp4jStatistics() != SNMP4JSettings.Snmp4jStatistics.none) {
counterSupport = CounterSupport.getInstance();
}
}
/**
* Creates a {@code Snmp} instance by supplying a {@code MessageDispatcher}.
*
* The supplied message dispatcher is not altered in terms of adding any message processing models to it. This has
* to be done now outside the Snmp class.
*
*
* Do not forget to add at least one transport mapping before calling the listen method!
*
* To initialize a {@code Snmp} instance created with this constructor follow this sample code:
*
* Transport transport = ...;
* SecurityProtocols.getInstance().addDefaultProtocols();
* MessageDispatcher disp = new MessageDispatcherImpl();
* disp.addMessageProcessingModel(new MPv1());
* disp.addMessageProcessingModel(new MPv2c());
* Snmp snmp = new Snmp(disp);
* snmp.addTransportMapping(transport);
* OctetString localEngineID = new OctetString(
* MPv3.createLocalEngineID());
* // For command generators, you may use the following code to avoid
* // engine ID clashes:
* // MPv3.createLocalEngineID(
* // new OctetString("MyUniqueID"+System.currentTimeMillis())));
* USM usm = new USM(SecurityProtocols.getInstance(), localEngineID, 0);
* disp.addMessageProcessingModel(new MPv3(usm));
* snmp.listen();
*
*
* @param messageDispatcher
* a {@code MessageDispatcher} instance that will be used to dispatch incoming and outgoing messages.
*
* @since 1.5
*/
public Snmp(MessageDispatcher messageDispatcher) {
this.messageDispatcher = messageDispatcher;
this.messageDispatcher.addCommandResponder(this);
if (SNMP4JSettings.getSnmp4jStatistics() != SNMP4JSettings.Snmp4jStatistics.none) {
counterSupport = CounterSupport.getInstance();
}
}
/**
* Returns the message dispatcher associated with this SNMP session.
*
* @return a {@code MessageDispatcher} instance.
* @since 1.1
*/
public MessageDispatcher getMessageDispatcher() {
return messageDispatcher;
}
/**
* Sets the message dispatcher associated with this SNMP session. The {@link CommandResponder} registration is
* removed from the existing message dispatcher (if not {@code null}).
*
* @param messageDispatcher
* a message dispatcher that processes incoming SNMP {@link PDU}s.
*
* @since 2.5.7
*/
@SuppressWarnings("unchecked")
public void setMessageDispatcher(MessageDispatcher messageDispatcher) {
if (messageDispatcher == null) {
throw new NullPointerException();
}
Collection> existingTransportMappings = new LinkedList<>();
if (this.messageDispatcher != null) {
existingTransportMappings = messageDispatcher.getTransportMappings();
for (TransportMapping tm : existingTransportMappings) {
removeTransportMapping(tm);
}
this.messageDispatcher.removeCommandResponder(this);
}
this.messageDispatcher = messageDispatcher;
this.messageDispatcher.addCommandResponder(this);
for (TransportMapping tm : existingTransportMappings) {
addTransportMapping(tm);
}
}
/**
* Adds a {@code TransportMapping} to this SNMP session.
*
* @param transportMapping
* a {@code TransportMapping} instance.
*/
public void addTransportMapping(TransportMapping transportMapping) {
// connect transport mapping with message dispatcher
messageDispatcher.addTransportMapping(transportMapping);
transportMapping.addTransportListener(messageDispatcher);
}
/**
* Removes the specified transport mapping from this SNMP session. If the transport mapping is not currently part of
* this SNMP session, this method will have no effect.
*
* @param transportMapping
* a previously added {@code TransportMapping}.
*/
public void removeTransportMapping(TransportMapping transportMapping) {
messageDispatcher.removeTransportMapping(transportMapping);
transportMapping.removeTransportListener(messageDispatcher);
}
/**
* Adds a notification listener to this Snmp instance. Calling this method will create a transport mapping for the
* specified listening address and registers the provided {@code CommandResponder} with the internal {@code
* NotificationDispatcher}.
*
* @param transportMapping
* the TransportMapping that is listening on the provided listenAddress. Call {@code
* TransportMappings.getInstance().createTransportMapping(listenAddress);} to create such a transport
* mapping.
* @param listenAddress
* the {@code Address} denoting the transport end-point (interface and port) to listen for incoming
* notifications.
* @param listener
* the {@code CommandResponder} instance that should handle the received notifications.
*
* @return {@code true} if registration was successful and {@code false} if, for example, the transport mapping for
* the listen address could not be created.
* @since 2.5.0
*/
public synchronized boolean addNotificationListener(TransportMapping transportMapping,
Address listenAddress,
CommandResponder listener) {
if (transportMapping instanceof ConnectionOrientedTransportMapping) {
((ConnectionOrientedTransportMapping) transportMapping).setConnectionTimeout(0);
}
transportMapping.addTransportListener(messageDispatcher);
if (notificationDispatcher == null) {
notificationDispatcher = createNotificationDispatcher();
addCommandResponder(notificationDispatcher);
}
notificationDispatcher.addNotificationListener(listenAddress, transportMapping, listener);
try {
transportMapping.listen();
if (logger.isInfoEnabled()) {
logger.info("Added notification listener for address: " +
listenAddress);
}
return true;
} catch (IOException ex) {
logger.warn("Failed to initialize notification listener for address '" +
listenAddress + "': " + ex.getMessage());
return false;
}
}
/**
* Creates the internal {@link NotificationDispatcher} used to dispatch notifications.
* @return a new notification dispatcher instance derived from the {@link NotificationDispatcher} class.
* @since 3.4.2
*/
protected NotificationDispatcher createNotificationDispatcher() {
return new NotificationDispatcher();
}
/**
* Adds a notification listener to this Snmp instance. Calling this method will create a transport mapping for the
* specified listening address and registers the provided {@code CommandResponder} with the internal {@code
* NotificationDispatcher}.
*
* @param listenAddress
* the {@code Address} denoting the transport end-point (interface and port) to listen for incoming
* notifications.
* @param listener
* the {@code CommandResponder} instance that should handle the received notifications.
*
* @return {@code true} if registration was successful and {@code false} if, for example, the transport mapping for
* the listen address could not be created.
* @since 1.6
*/
public synchronized boolean addNotificationListener(Address listenAddress, CommandResponder listener) {
TransportMapping tm = TransportMappings.getInstance().createTransportMapping(listenAddress);
if (tm == null) {
if (logger.isInfoEnabled()) {
logger.info("Failed to add notification listener for address: " +
listenAddress);
}
return false;
}
return addNotificationListener(tm, listenAddress, listener);
}
/**
* Removes (deletes) the notification listener for the specified transport endpoint.
*
* @param listenAddress
* the listen {@code Address} to be removed.
*
* @return {@code true} if the notification listener has been removed successfully.
*/
public synchronized boolean removeNotificationListener(Address listenAddress) {
if (notificationDispatcher != null) {
if (logger.isInfoEnabled()) {
logger.info("Removing notification listener for address: " +
listenAddress);
}
return notificationDispatcher.removeNotificationListener(listenAddress);
} else {
return false;
}
}
/**
* Gets the transport mapping registered for the specified listen address.
*
* @param listenAddress
* the listen address.
*
* @return the {@link TransportMapping} for the specified listen address or {@code null} if there is no notification
* listener for that address.
* @since 2.5.0
*/
public TransportMapping getNotificationListenerTM(Address listenAddress) {
NotificationDispatcher nd = notificationDispatcher;
if (nd != null) {
return nd.getTransportMapping(listenAddress);
}
return null;
}
/**
* Puts all associated transport mappings into listen mode.
*
* @throws IOException
* if a transport mapping throws an {@code IOException} when its {@link TransportMapping#listen()} method
* has been called.
*/
public void listen() throws IOException {
for (TransportMapping tm : messageDispatcher.getTransportMappings()) {
if (!tm.isListening()) {
tm.listen();
}
}
}
/**
* Gets the next unique request ID. The returned ID is unique across the last 2^31-1 IDs generated by this message
* dispatcher.
*
* @return an integer value in the range 1..2^31-1. The returned ID can be used to map responses to requests send
* through this message dispatcher.
* @see MessageDispatcher#getNextRequestID
* @since 1.1
*/
public int getNextRequestID() {
return messageDispatcher.getNextRequestID();
}
/**
* Closes the session and frees any allocated resources, i.e. sockets and the internal thread for processing request
* timeouts. In addition, {@link MessageDispatcher#stop()} is called to temrinate and free resources from the
* used message dispatcher too.
*
* If there are any pending requests, the {@link ResponseListener} associated with the pending requests, will be
* called with a {@code null} response and a {@link InterruptedException} in the error member of the {@link
* ResponseEvent} returned.
*
* After a {@code Session} has been closed it must not be used anymore.
*
* @throws IOException
* if a transport mapping cannot be closed successfully.
*/
@Override
public void close() throws IOException {
for (TransportMapping tm : messageDispatcher.getTransportMappings()) {
tm.close();
}
CommonTimer t = timer;
timer = null;
if (t != null) {
t.cancel();
}
// close all notification listeners
if (notificationDispatcher != null) {
notificationDispatcher.closeAll();
}
List> pr;
synchronized (pendingRequests) {
pr = new ArrayList<>(pendingRequests.values());
}
for (PendingRequest pending : pr) {
pending.cancel();
ResponseEvent e =
new ResponseEvent<>(this, null, pending.pdu, null, pending.userObject,
new InterruptedException(
"Snmp session has been closed"));
ResponseListener l = pending.listener;
if (l != null) {
l.onResponse(e);
}
}
pendingRequests.clear();
asyncRequests.clear();
messageDispatcher.stop();
}
/**
* Sends a GET request to a target. This method sets the PDU's type to {@link PDU#GET} and then sends a synchronous
* request to the supplied target.
*
* @param pdu
* a {@code PDU} instance. For SNMPv3 messages, the supplied PDU instance has to be a {@code ScopedPDU}
* instance.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param
* type of the target {@link Address}
*
* @return the received response encapsulated in a {@code ResponseEvent} instance. To obtain the received response
* {@code PDU} call {@link ResponseEvent#getResponse()}. If the request timed out, that method will return {@code
* null}.
* @throws IOException
* if the PDU cannot be sent to the target.
* @since 1.1
*/
public ResponseEvent get(PDU pdu, Target target) throws IOException {
pdu.setType(PDU.GET);
return send(pdu, target);
}
/**
* Asynchronously sends a GET request {@code PDU} to the given target. The response is then returned by calling the
* supplied {@code ResponseListener} instance.
*
* @param pdu
* the PDU instance to send.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param userHandle
* an user defined handle that is returned when the request is returned via the {@code listener} object.
* @param listener
* a {@code ResponseListener} instance that is called when {@code pdu} is a confirmed PDU and the request is
* either answered or timed out.
* @param
* type of the target {@link Address}
*
* @throws IOException
* if the PDU cannot be sent to the target.
* @since 1.1
*/
public void get(PDU pdu, Target target, Object userHandle, ResponseListener listener)
throws IOException {
pdu.setType(PDU.GET);
send(pdu, target, userHandle, listener);
}
/**
* Sends a GETNEXT request to a target. This method sets the PDU's type to {@link PDU#GETNEXT} and then sends a
* synchronous request to the supplied target. This method is a convenience wrapper for the {@link #send(PDU pdu,
* Target target)} method.
*
* @param pdu
* a {@code PDU} instance. For SNMPv3 messages, the supplied PDU instance has to be a {@code ScopedPDU}
* instance.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param
* type of the target {@link Address}
*
* @return the received response encapsulated in a {@code ResponseEvent} instance. To obtain the received response
* {@code PDU} call {@link ResponseEvent#getResponse()}. If the request timed out, that method will return {@code
* null}.
* @throws IOException
* if the PDU cannot be sent to the target.
* @since 1.1
*/
public ResponseEvent getNext(PDU pdu, Target target) throws IOException {
pdu.setType(PDU.GETNEXT);
return send(pdu, target);
}
/**
* Asynchronously sends a GETNEXT request {@code PDU} to the given target. The response is then returned by calling
* the supplied {@code ResponseListener} instance.
*
* @param pdu
* the PDU instance to send.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param userHandle
* an user defined handle that is returned when the request is returned via the {@code listener} object.
* @param listener
* a {@code ResponseListener} instance that is called when {@code pdu} is a confirmed PDU and the request is
* either answered or timed out.
* @param
* type of the target {@link Address}
*
* @throws IOException
* if the PDU cannot be sent to the target.
* @since 1.1
*/
public void getNext(PDU pdu, Target target, Object userHandle, ResponseListener listener)
throws IOException {
pdu.setType(PDU.GETNEXT);
send(pdu, target, userHandle, listener);
}
/**
* Sends a GETBULK request to a target. This method sets the PDU's type to {@link PDU#GETBULK} and then sends a
* synchronous request to the supplied target. This method is a convenience wrapper for the {@link #send(PDU pdu,
* Target target)} method.
*
* @param pdu
* a {@code PDU} instance. For SNMPv3 messages, the supplied PDU instance has to be a {@code ScopedPDU}
* instance.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param
* type of the target {@link Address}
*
* @return the received response encapsulated in a {@code ResponseEvent} instance. To obtain the received response
* {@code PDU} call {@link ResponseEvent#getResponse()}. If the request timed out, that method will return {@code
* null}.
* @throws IOException
* if the PDU cannot be sent to the target.
* @since 1.1
*/
public ResponseEvent getBulk(PDU pdu, Target target) throws IOException {
pdu.setType(PDU.GETBULK);
return send(pdu, target);
}
/**
* Asynchronously sends a GETBULK request {@code PDU} to the given target. The response is then returned by calling
* the supplied {@code ResponseListener} instance.
*
* @param pdu
* the PDU instance to send.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param userHandle
* an user defined handle that is returned when the request is returned via the {@code listener} object.
* @param listener
* a {@code ResponseListener} instance that is called when {@code pdu} is a confirmed PDU and the request is
* either answered or timed out.
* @param
* type of the target {@link Address}
*
* @throws IOException
* if the PDU cannot be sent to the target.
* @since 1.1
*/
public void getBulk(PDU pdu, Target target, Object userHandle, ResponseListener listener)
throws IOException {
pdu.setType(PDU.GETBULK);
send(pdu, target, userHandle, listener);
}
/**
* Sends an INFORM request to a target. This method sets the PDU's type to {@link PDU#INFORM} and then sends a
* synchronous request to the supplied target. This method is a convenience wrapper for the {@link #send(PDU pdu,
* Target target)} method.
*
* @param pdu
* a {@code PDU} instance. For SNMPv3 messages, the supplied PDU instance has to be a {@code ScopedPDU}
* instance.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param
* type of the target {@link Address}
*
* @return the received response encapsulated in a {@code ResponseEvent} instance. To obtain the received response
* {@code PDU} call {@link ResponseEvent#getResponse()}. If the request timed out, that method will return {@code
* null}.
* @throws IOException
* if the inform request could not be send to the specified target.
* @since 1.1
*/
public ResponseEvent inform(PDU pdu, Target target) throws IOException {
pdu.setType(PDU.INFORM);
return send(pdu, target);
}
/**
* Asynchronously sends an INFORM request {@code PDU} to the given target. The response is then returned by calling
* the supplied {@code ResponseListener} instance.
*
* @param pdu
* the PDU instance to send.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param userHandle
* an user defined handle that is returned when the request is returned via the {@code listener} object.
* @param listener
* a {@code ResponseListener} instance that is called when {@code pdu} is a confirmed PDU and the request is
* either answered or timed out.
* @param
* type of the target {@link Address}
*
* @throws IOException
* if the PDU cannot be sent to the target.
* @since 1.1
*/
public void inform(PDU pdu, Target target, Object userHandle, ResponseListener listener)
throws IOException {
pdu.setType(PDU.INFORM);
send(pdu, target, userHandle, listener);
}
/**
* Sends a SNMPv1 trap to a target. This method sets the PDU's type to {@link PDU#V1TRAP} and then sends it to the
* supplied target. This method is a convenience wrapper for the {@link #send(PDU pdu, Target target)} method.
*
* @param pdu
* a {@code PDUv1} instance.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}. The selected SNMP
* protocol version for the target must be {@link SnmpConstants#version1}.
*
* @throws IOException
* if the trap cannot be sent.
* @since 1.1
*/
public void trap(PDUv1 pdu, Target target) throws IOException {
if (target.getVersion() != SnmpConstants.version1) {
throw new IllegalArgumentException(
"SNMPv1 trap PDU must be used with SNMPv1");
}
pdu.setType(PDU.V1TRAP);
send(pdu, target);
}
/**
* Sends a SNMPv2c or SNMPv3 notification to a target. This method sets the PDU's type to {@link PDU#NOTIFICATION}
* and then sends it to the supplied target. This method is a convenience wrapper for the {@link #send(PDU pdu,
* Target target)} method.
*
* @param pdu
* a {@code PDUv1} instance.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}. The selected SNMP
* protocol version for the target must be {@link SnmpConstants#version2c} or {@link
* SnmpConstants#version2c}.
*
* @throws IOException
* if the notification cannot be sent.
* @since 1.1
*/
public void notify(PDU pdu, Target target) throws IOException {
if (target.getVersion() == SnmpConstants.version1) {
throw new IllegalArgumentException(
"Notifications PDUs cannot be used with SNMPv1");
}
pdu.setType(PDU.NOTIFICATION);
send(pdu, target);
}
/**
* Sends a SET request to a target. This method sets the PDU's type to {@link PDU#SET} and then sends a synchronous
* request to the supplied target.
*
* @param pdu
* a {@code PDU} instance. For SNMPv3 messages, the supplied PDU instance has to be a {@code ScopedPDU}
* instance.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param
* type of the target {@link Address}
*
* @return the received response encapsulated in a {@code ResponseEvent} instance. To obtain the received response
* {@code PDU} call {@link ResponseEvent#getResponse()}. If the request timed out, that method will return {@code
* null}.
* @throws IOException
* if the PDU cannot be sent to the target.
* @since 1.1
*/
public ResponseEvent set(PDU pdu, Target target) throws IOException {
pdu.setType(PDU.SET);
return send(pdu, target);
}
/**
* Asynchronously sends a SET request {@code PDU} to the given target. The response is then returned by calling the
* supplied {@code ResponseListener} instance.
*
* @param pdu
* the PDU instance to send.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param userHandle
* an user defined handle that is returned when the request is returned via the {@code listener} object.
* @param listener
* a {@code ResponseListener} instance that is called when {@code pdu} is a confirmed PDU and the request is
* either answered or timed out.
*
* @throws IOException
* if the PDU cannot be sent to the target.
* @since 1.1
*/
public void set(PDU pdu, Target target, Object userHandle, ResponseListener listener) throws IOException {
pdu.setType(PDU.SET);
send(pdu, target, userHandle, listener);
}
public ResponseEvent send(PDU pdu, Target target) throws IOException {
return send(pdu, target, null);
}
/**
* Sends a {@code PDU} to the given target and if the {@code PDU} is a confirmed request, then the received response
* is returned synchronously.
*
* @param pdu
* a {@code PDU} instance. When sending a SNMPv1 trap PDU, the supplied PDU instance must be a {@code
* PDUv1}. For all types of SNMPv3 messages, the supplied PDU instance has to be a {@code ScopedPDU}
* instance.
* @param target
* the Target instance representing the target SNMP engine where to send the {@code pdu}.
* @param transport
* specifies the {@code TransportMapping} to be used when sending the PDU. If {@code transport} is {@code
* null}, the associated message dispatcher will try to determine the transport mapping by the {@code
* target}'s address.
* @param
* type of the target {@link Address}
*
* @return the received response encapsulated in a {@code ResponseEvent} instance. To obtain the received response
* {@code PDU} call {@link ResponseEvent#getResponse()}. If the request timed out, that method will return {@code
* null}. If the sent {@code pdu} is an unconfirmed PDU (notification, response, or report), then {@code null} will
* be returned.
* @throws IOException
* if the message could not be sent.
* @see PDU
* @see ScopedPDU
* @see PDUv1
*/
public ResponseEvent send(PDU pdu, Target target, TransportMapping transport)
throws IOException {
return send(pdu, target, transport, DEFAULT_MAX_REQUEST_STATUS);
}
private ResponseEvent send(PDU pdu, Target target, TransportMapping transport,
int maxRequestStatus) throws IOException {
if (!pdu.isConfirmedPdu()) {
sendMessage(pdu, target, transport, null);
return null;
}
if (timer == null) {
createPendingTimer();
}
final SyncResponseListener syncResponse = new SyncResponseListener<>();
PendingRequest retryRequest = null;
synchronized (syncResponse) {
PduHandle handle = null;
PendingRequest request = new PendingRequest(syncResponse, target, pdu, target, transport);
request.maxRequestStatus = maxRequestStatus;
handle = sendMessage(request.pdu, target, transport, request);
long totalTimeout =
timeoutModel.getRequestTimeout(target.getRetries(),
target.getTimeout());
long stopTime = System.nanoTime() + totalTimeout * SnmpConstants.MILLISECOND_TO_NANOSECOND;
try {
long waitMillis;
while ((syncResponse.getResponse() == null) &&
((waitMillis = (stopTime - System.nanoTime()) / SnmpConstants.MILLISECOND_TO_NANOSECOND) > 0)) {
syncResponse.wait(waitMillis);
}
retryRequest = pendingRequests.remove(handle);
if (logger.isDebugEnabled()) {
logger.debug("Removed pending request with handle: " + handle);
}
request.setFinished();
request.cancel();
} catch (InterruptedException iex) {
logger.warn(iex);
// cleanup request
request.setFinished();
request.cancel();
retryRequest = pendingRequests.remove(handle);
if (retryRequest != null) {
retryRequest.setFinished();
retryRequest.cancel();
}
Thread.currentThread().interrupt();
} finally {
if (!request.finished) {
// free resources
retryRequest = pendingRequests.remove(handle);
if (retryRequest != null) {
retryRequest.setFinished();
retryRequest.cancel();
}
}
}
}
if (retryRequest != null) {
retryRequest.setFinished();
retryRequest.cancel();
}
return Objects.requireNonNullElse(syncResponse.getResponse(),
new ResponseEvent(this, null, pdu, null, null));
}
private synchronized void createPendingTimer() {
if (timer == null) {
timer = SNMP4JSettings.getTimerFactory().createTimer();
}
}
@Override
public void send(PDU pdu, Target target, Object userHandle, ResponseListener listener)
throws IOException {
send(pdu, target, null, userHandle, listener);
}
public void send(PDU pdu, Target target, TransportMapping transport,
Object userHandle, ResponseListener listener) throws IOException {
if (!pdu.isConfirmedPdu()) {
sendMessage(pdu, target, transport, null);
return;
}
if (timer == null) {
createPendingTimer();
}
PendingRequest request = new AsyncPendingRequest(listener, userHandle, pdu, target, transport);
sendMessage(request.pdu, target, transport, request);
}
/**
* Actually sends a PDU to a target and returns a handle for the sent PDU.
*
* @param pdu
* the {@code PDU} instance to be sent.
* @param target
* a {@code Target} instance denoting the target SNMP entity.
* @param transport
* the (optional) transport mapping to be used to send the request. If {@code transport} is {@code null} a
* suitable transport mapping is determined from the {@code target} address.
* @param pduHandleCallback
* callback for newly created PDU handles before the request is sent out.
* @param
* the target {@link Address} type.
*
* @return PduHandle that uniquely identifies the sent PDU for further reference.
* @throws IOException
* if the transport fails to send the PDU or the if the message cannot be BER encoded.
*/
protected PduHandle sendMessage(PDU pdu, Target target,
TransportMapping transport,
PduHandleCallback pduHandleCallback)
throws IOException {
TransportMapping tm = transport;
if (tm == null) {
tm = lookupTransportMapping(target);
}
return messageDispatcher.sendPdu(tm, target, pdu, true, pduHandleCallback);
}
protected TransportMapping lookupTransportMapping(Target target) {
List> preferredTransports = target.getPreferredTransports();
if (preferredTransports != null) {
for (TransportMapping tm : preferredTransports) {
if (tm.isAddressSupported(target.getAddress())) {
return tm;
}
}
}
return null;
}
public void cancel(PDU request, ResponseListener listener) {
AsyncRequestKey key = new AsyncRequestKey(request, listener);
PduHandle pending = asyncRequests.remove(key);
if (logger.isDebugEnabled()) {
logger.debug("Cancelling pending request with handle " + pending);
}
if (pending != null) {
PendingRequest pendingRequest = pendingRequests.remove(pending);
if (pendingRequest != null) {
synchronized (pendingRequest) {
pendingRequest.setFinished();
pendingRequest.cancel();
}
}
}
}
/**
* Sets the local engine ID for the SNMP entity represented by this {@code Snmp} instance. This is a convenience
* method that sets the local engine ID in the associated {@code MPv3} and {@code USM}.
*
* @param engineID
* a byte array containing the local engine ID. The length and content has to comply with the constraints
* defined in the SNMP-FRAMEWORK-MIB.
* @param engineBoots
* the number of boots of this SNMP engine (zero based).
* @param engineTime
* the number of seconds since the value of engineBoots last changed.
*
* @see MPv3
* @see USM
*/
@Override
public void setLocalEngine(byte[] engineID,
int engineBoots,
int engineTime) {
MPv3 mpv3 = getMPv3();
mpv3.setLocalEngineID(engineID);
mpv3.setCurrentMsgID(MPv3.randomMsgID(engineBoots));
USM usm = (USM) mpv3.getSecurityModel(SecurityModel.SECURITY_MODEL_USM);
if (usm != null) {
usm.setLocalEngine(new OctetString(engineID), engineBoots, engineTime);
}
}
/**
* Gets the local engine ID if the MPv3 is available, otherwise a runtime exception is thrown.
*
* @return byte[] the local engine ID.
*/
@Override
public byte[] getLocalEngineID() {
return getMPv3().getLocalEngineID();
}
private MPv3 getMPv3() {
MPv3 mpv3 = (MPv3) getMessageProcessingModel(MessageProcessingModel.MPv3);
if (mpv3 == null) {
throw new NoSuchElementException("MPv3 not available");
}
return mpv3;
}
/**
* Discovers the engine ID of the SNMPv3 entity denoted by the supplied address. This method does not need to be
* called for normal operation, because SNMP4J automatically discovers authoritative engine IDs and also
* automatically synchronize engine time values.
*
* For this method to operate successfully, the discover engine IDs
* flag in {@link USM} must be {@code true} (which is the default).
*
*
* @param address
* an Address instance representing the transport address of the SNMPv3 entity for which its authoritative
* engine ID should be discovered.
* @param timeout
* the maximum time in milliseconds to wait for a response.
* @param
* the {@link Address} type.
*
* @return a byte array containing the authoritative engine ID or {@code null} if it could not be discovered.
* @see USM#setEngineDiscoveryEnabled(boolean enableEngineDiscovery)
*/
public byte[] discoverAuthoritativeEngineID(A address, long timeout) {
MPv3 mpv3 = getMPv3();
// We need to remove the engine ID explicitly to be sure that it is updated
OctetString engineID = mpv3.removeEngineID(address);
// Now try to remove the engine as well
if (engineID != null) {
USM usm = getUSM();
if (usm != null) {
usm.removeEngineTime(engineID);
}
}
ScopedPDU scopedPDU = new ScopedPDU();
scopedPDU.setType(PDU.GET);
SecureTarget target = new UserTarget();
target.setTimeout(timeout);
target.setAddress(address);
target.setSecurityLevel(SecurityLevel.NOAUTH_NOPRIV);
try {
send(scopedPDU, target, null, ENGINE_ID_DISCOVERY_MAX_REQUEST_STATUS);
OctetString authoritativeEngineID = mpv3.getEngineID(address);
if (authoritativeEngineID == null) {
return null;
}
// we copy the byte array here, so we are sure nobody can modify the
// internal cache.
return new OctetString(authoritativeEngineID.getValue()).getValue();
} catch (IOException ex) {
logger.error(
"IO error while trying to discover authoritative engine ID: " +
ex);
return null;
}
}
/**
* Gets the User Based Security Model (USM). This is a convenience method that uses the {@link
* MPv3#getSecurityModel} method of the associated MPv3 instance to get the USM.
*
* @return the {@code USM} instance associated with the MPv3 bound to this {@code Snmp} instance, or {@code null}
* otherwise.
*/
public USM getUSM() {
MPv3 mp = (MPv3) getMessageProcessingModel(MPv3.ID);
if (mp != null) {
return (USM) mp.getSecurityModel(SecurityModel.SECURITY_MODEL_USM);
}
return null;
}
/**
* Gets the message processing model for the supplied ID.
*
* @param messageProcessingModel
* a mesage processing model ID as defined in {@link MessageProcessingModel}.
*
* @return MessageProcessingModel a {@code MessageProcessingModel} if {@code messageProcessingModel} has been
* registered with the message dispatcher associated with this SNMP session.
*/
public MessageProcessingModel getMessageProcessingModel(int messageProcessingModel) {
return messageDispatcher.getMessageProcessingModel(messageProcessingModel);
}
/**
* Process an incoming request or notification PDU.
*
* @param event
* a {@code CommandResponderEvent} with the decoded incoming PDU as dispatched to this method call by the
* associated message dispatcher.
* @param
* type of the peer {@link Address}.
*/
public void processPdu(CommandResponderEvent event) {
PduHandle handle = event.getPduHandle();
if ((SNMP4JSettings.getSnmp4jStatistics() == SNMP4JSettings.Snmp4jStatistics.extended) &&
(handle instanceof RequestStatistics)) {
RequestStatistics requestStatistics = (RequestStatistics) handle;
counterSupport.fireIncrementCounter(new CounterEvent(Snmp.this, SnmpConstants.snmp4jStatsRequestRuntime,
requestStatistics.getResponseRuntimeNanos()));
CounterEvent counterEvent =
new CounterEvent(Snmp.this, SnmpConstants.snmp4jStatsReqTableRuntime, event.getPeerAddress(),
requestStatistics.getResponseRuntimeNanos());
counterSupport.fireIncrementCounter(counterEvent);
}
PDU pdu = event.getPDU();
if (pdu.getType() == PDU.REPORT) {
event.setProcessed(true);
reportHandler.processReport(handle, event);
} else if (pdu.getType() == PDU.RESPONSE) {
event.setProcessed(true);
PendingRequest request;
if (logger.isDebugEnabled()) {
logger.debug("Looking up pending request with handle " + handle);
}
synchronized (pendingRequests) {
request = pendingRequests.get(handle);
if (request != null) {
request.responseReceived();
}
}
if (request == null) {
if (logger.isWarnEnabled()) {
logger.warn("Received response that cannot be matched to any " +
"outstanding request, address=" +
event.getPeerAddress() +
", requestID=" + pdu.getRequestID());
}
} else if (!resendRequest(request, pdu)) {
ResponseListener l = request.listener;
if (l != null) {
l.onResponse(new ResponseEvent(this, event.getPeerAddress(), request.pdu, pdu,
request.userObject));
}
}
} else {
if (logger.isDebugEnabled()) {
logger.debug("Fire process PDU event: " + event.toString());
}
fireProcessPdu(event);
}
}
/**
* Checks whether RFC5343 based context engine ID discovery is disabled or not. The default value is {@code false}.
*
* @return {@code true} if context engine ID discovery is disabled.
* @since 2.0
*/
public boolean isContextEngineIdDiscoveryDisabled() {
return contextEngineIdDiscoveryDisabled;
}
/**
* Sets the RFC5343 based context engine ID discovery. The default value is {@code false}.
*
* @param contextEngineIdDiscoveryDisabled
* {@code true} to disable context engine ID discovery and remove all cached context engine IDs from
* the internal cache, {@code false} to enable context engine ID discovery.
*
* @since 2.0
*/
public void setContextEngineIdDiscoveryDisabled(boolean contextEngineIdDiscoveryDisabled) {
this.contextEngineIdDiscoveryDisabled = contextEngineIdDiscoveryDisabled;
this.contextEngineIDs.clear();
}
/**
* Get a cached RFC 5343 context engine ID for the specified address.
* @param targetAddress
* the target address that returned the context engine ID.
* @return
* the cached context engine ID retrieved by RFC 5343 discovery or {@code null} if no such ID had been cached
* yet or the cached value was already removed either explicitly with
* {@link #removeCachedContextEngineId(Address)} or implicitly because the address object was no longer
* associated with any open connection (i.e., the internally {@link WeakHashMap} recognized no more active
* references on the address key).
* @since 3.6.5
*/
public OctetString getCachedContextEngineId(Address targetAddress) {
return contextEngineIDs.get(targetAddress);
}
/**
* Remove a cached RFC 5343 context engine ID for the specified address and return it. To remove all cached IDs,
* call {@link #setContextEngineIdDiscoveryDisabled(boolean)} with {@code true}.
* @param target
* the target address that returned the context engine ID.
* @return
* the removed cached context engine ID retrieved by RFC 5343 discovery or {@code null}
* if no such ID had been cached yet.
* @since 3.6.5
*/
public OctetString removeCachedContextEngineId(Address target) {
return contextEngineIDs.remove(target);
}
protected boolean resendRequest(PendingRequest request, PDU response) {
if (request.useNextPDU()) {
request.responseReceived = false;
pendingRequests.remove(request.key);
PduHandle holdKeyUntilResendDone = request.key;
request.key = null;
handleInternalResponse(response, request.pdu, request.target.getAddress());
try {
sendMessage(request.pdu, request.target, request.transport, request);
} catch (IOException e) {
logger.error("IOException while resending request after RFC 5343 context engine ID discovery: " +
e.getMessage(), e);
}
// now the previous retry can be released
if (logger.isDebugEnabled()) {
logger.debug("Releasing PDU handle " + holdKeyUntilResendDone);
}
holdKeyUntilResendDone = null;
return true;
}
return false;
}
protected void handleInternalResponse(PDU response, PDU pdu, Address target) {
Variable contextEngineID = response.getVariable(SnmpConstants.snmpEngineID);
if (contextEngineID instanceof OctetString) {
if (pdu instanceof ScopedPDU) {
((ScopedPDU) pdu).setContextEngineID((OctetString) contextEngineID);
contextEngineIDs.put(target, (OctetString) contextEngineID);
if (logger.isInfoEnabled()) {
logger.info("Discovered contextEngineID '" + contextEngineID +
"' by RFC 5343 for " + target);
}
}
}
}
class ReportProcessor implements ReportHandler {
public void processReport(PduHandle handle, CommandResponderEvent e) {
PDU pdu = e.getPDU();
logger.debug("Searching pending request with handle" + handle);
@SuppressWarnings("unchecked")
PendingRequest request = (PendingRequest) pendingRequests.get(handle);
VariableBinding vb = checkReport(e, pdu, request);
if (vb == null) return;
OID firstOID = vb.getOid();
boolean resend = false;
if (request.requestStatus < request.maxRequestStatus) {
switch (request.requestStatus) {
case 0:
if (SnmpConstants.usmStatsUnknownEngineIDs.equals(firstOID)) {
resend = true;
} else if (SnmpConstants.usmStatsNotInTimeWindows.equals(firstOID)) {
request.requestStatus++;
resend = true;
}
break;
case 1:
if (SnmpConstants.usmStatsNotInTimeWindows.equals(firstOID)) {
resend = true;
}
break;
}
}
// if legal report PDU received, then resend request
if (resend) {
logger.debug("Send new request after report " + firstOID);
request.requestStatus++;
try {
// We need no callback here because we already have an equivalent
// handle registered.
PduHandle resentHandle = sendMessage(request.pdu, request.target, e.getTransportMapping(), null);
// make sure reference to handle is hold until request is finished,
// because otherwise cache information may get lost (WeakHashMap)
request.key = resentHandle;
} catch (IOException iox) {
logger.error("Failed to send message to " + request.target + ": " +
iox.getMessage());
return;
}
} else {
boolean intime;
// Get the request members needed before canceling the request
// which resets it
ResponseListener reqListener = request.listener;
PDU reqPDU = request.pdu;
Object reqUserObject = request.userObject;
synchronized (request) {
intime = request.cancel();
}
// remove pending request
// (sync is not needed as request is already canceled)
pendingRequests.remove(handle);
if (intime && (reqListener != null)) {
// return report
reqListener.onResponse(new ResponseEvent(Snmp.this, e.getPeerAddress(), reqPDU, pdu,
reqUserObject));
} else {
// silently drop late report
if (logger.isInfoEnabled()) {
logger.info("Received late report from " +
e.getPeerAddress() +
" with request ID " + pdu.getRequestID());
}
}
}
}
protected VariableBinding checkReport(CommandResponderEvent e, PDU pdu,
PendingRequest request) {
if (request == null) {
logger.warn("Unmatched report PDU received from " + e.getPeerAddress());
return null;
}
if (pdu.size() == 0) {
logger.error("Illegal report PDU received from " + e.getPeerAddress() +
" missing report variable binding");
return null;
}
VariableBinding vb = pdu.get(0);
if (vb == null) {
logger.error("Received illegal REPORT PDU from " + e.getPeerAddress());
return null;
}
// RFC 7.2.11 (b):
if (e.getSecurityModel() != request.target.getSecurityModel()) {
logger.warn("RFC3412 §7.2.11.b: Received REPORT PDU with different security model than cached one: " + e);
return null;
}
// RFC 7.2.11 (b):
if ((e.getSecurityLevel() == SecurityLevel.NOAUTH_NOPRIV) &&
(SNMP4JSettings.getReportSecurityLevelStrategy() !=
SNMP4JSettings.ReportSecurityLevelStrategy.noAuthNoPrivIfNeeded) &&
((e.getSecurityLevel() != request.target.getSecurityLevel()) &&
(!SnmpConstants.usmStatsUnknownUserNames.equals(vb.getOid())) &&
(!SnmpConstants.usmStatsUnknownEngineIDs.equals(vb.getOid())))) {
logger.warn("RFC3412 §7.2.11.b:Received REPORT PDU with security level noAuthNoPriv from '" + e + "'. " +
"Ignoring it, because report strategy is set to " +
SNMP4JSettings.getReportSecurityLevelStrategy());
return null;
}
return vb;
}
}
/**
* Removes a {@code CommandResponder} from this SNMP session.
*
* @param listener
* a previously added {@code CommandResponder} instance.
*/
public synchronized void removeCommandResponder(CommandResponder listener) {
if (commandResponderListeners != null &&
commandResponderListeners.contains(listener)) {
ArrayList v = new ArrayList(commandResponderListeners);
v.remove(listener);
commandResponderListeners = v;
}
}
/**
* Adds a {@code CommandResponder} to this SNMP session. The command responder will then be informed about incoming
* SNMP PDUs of any kind that are not related to any outstanding requests of this SNMP session.
*
* @param listener
* the {@code CommandResponder} instance to be added.
*/
public synchronized void addCommandResponder(CommandResponder listener) {
ArrayList v = (commandResponderListeners == null) ?
new ArrayList(2) :
new ArrayList(commandResponderListeners);
if (!v.contains(listener)) {
v.add(listener);
commandResponderListeners = v;
}
}
/**
* Fires a {@code CommandResponderEvent} event to inform listeners about a received PDU. If a listener has marked
* the event as processed further listeners will not be informed about the event.
*
* @param event
* a {@code CommandResponderEvent}.
*/
protected void fireProcessPdu(CommandResponderEvent event) {
if (commandResponderListeners != null) {
List listeners = commandResponderListeners;
for (CommandResponder listener : listeners) {
listener.processPdu(event);
// if event is marked as processed the event is not forwarded to
// remaining listeners
if (event.isProcessed()) {
return;
}
}
}
}
/**
* Gets the timeout model associated with this SNMP session.
*
* @return a TimeoutModel instance (never {@code null}).
* @see #setTimeoutModel(TimeoutModel timeoutModel)
*/
public TimeoutModel getTimeoutModel() {
return timeoutModel;
}
/**
* Returns the report handler which is used internally to process reports received from command responders.
*
* @return the {@code ReportHandler} instance.
* @since 1.6
*/
public ReportHandler getReportHandler() {
return reportHandler;
}
/**
* Gets the counter support for Snmp related counters. These are for example: snmp4jStatsRequestTimeouts,
* snmp4jStatsRequestTimeouts, snmp4jStatsRequestWaitTime
*
* @return the counter support if available. If the {@link SNMP4JSettings#getSnmp4jStatistics()} value is {@link
* org.snmp4j.SNMP4JSettings.Snmp4jStatistics#none} then no counter support will be created and no statistics will
* be collected.
* @since 2.4.2
*/
public CounterSupport getCounterSupport() {
return counterSupport;
}
/**
* Sets the counter support instance to handle counter events on behalf of this Snmp instance.
*
* @param counterSupport
* the counter support instance that collects the statistics events created by this Snmp instance. See also
* {@link #getCounterSupport()}.
*
* @since 2.4.2
*/
public void setCounterSupport(CounterSupport counterSupport) {
this.counterSupport = counterSupport;
}
/**
* Sets the timeout model for this SNMP session. The default timeout model sends retries whenever the time specified
* by the {@code timeout} parameter of the target has elapsed without a response being received for the request. By
* specifying a different timeout model this behaviour can be changed.
*
* @param timeoutModel
* a {@code TimeoutModel} instance (must not be {@code null}).
*/
public void setTimeoutModel(TimeoutModel timeoutModel) {
if (timeoutModel == null) {
throw new NullPointerException("Timeout model cannot be null");
}
this.timeoutModel = timeoutModel;
}
/**
* Sets the report handler and overrides the default report handler.
*
* @param reportHandler
* a {@code ReportHandler} instance which must not be {@code null}.
*
* @since 1.6
*/
public void setReportHandler(ReportHandler reportHandler) {
if (reportHandler == null) {
throw new IllegalArgumentException("ReportHandler must not be null");
}
this.reportHandler = reportHandler;
}
/**
* Gets the number of currently pending synchronous requests.
*
* @return the size of the synchronous request queue.
* @since 2.4.2
*/
public int getPendingSyncRequestCount() {
return pendingRequests.size();
}
/**
* Gets the number of currently pending asynchronous requests.
*
* @return the size of the asynchronous request queue.
* @since 2.4.2
*/
public int getPendingAsyncRequestCount() {
return asyncRequests.size();
}
private boolean isEmptyContextEngineID(PDU pdu) {
if (pdu instanceof ScopedPDU) {
ScopedPDU scopedPDU = (ScopedPDU) pdu;
return ((scopedPDU.getContextEngineID() == null) ||
(scopedPDU.getContextEngineID().length() == 0));
}
return false;
}
/**
* Create and return a {@link UsmUserEntry} with localized authentication and privacy keys from the provided
* authentication and privacy passwords.
*
* @param engineID
* the authoritative engine ID of the target for which the new {@link UsmUserEntry} should be localized.
* @param securityName
* the (security) user name of the user.
* @param authProtocol
* the authentication protocol OID. If {@code null} is provided, no authentication key and no privacy key
* will be set in the returned user entry.
* @param authPassword
* the password which will be localized using {@link SecurityProtocols#passwordToKey(OID, OctetString, byte[])}.
* If {@code null} is provided, no authentication key and no privacy key will be set in the returned
* user entry.
* @param privProtocol
* the authentication protocol OID. If {@code null} is provided, no authentication key and no privacy key
* will be set in the returned user entry.
* @param privPassword
* the password which will be localized using {@link SecurityProtocols#passwordToKey(OID, OID, OctetString, byte[])}.
* If {@code null} is provided, no privacy key will be set in the returned user entry.
* @return
* the created {@link UsmUserEntry} with any given passwords localized to the engine ID corresponding keys.
* @since 3.4.0
*/
public UsmUserEntry createLocalizedUsmUserEntry(byte[] engineID, OctetString securityName,
OID authProtocol, OctetString authPassword,
OID privProtocol, OctetString privPassword) {
MPv3 mPv3 = getMPv3();
SecurityProtocols securityProtocols = mPv3.getSecurityProtocols();
byte[] authKey = null;
byte[] privKey = null;
if (authProtocol != null && authPassword != null) {
authKey = securityProtocols.passwordToKey(authProtocol, authPassword, engineID);
if (privProtocol != null && privPassword != null) {
privKey = securityProtocols.passwordToKey(privProtocol, authProtocol, privPassword, engineID);
}
}
return new UsmUserEntry(engineID, securityName, authProtocol, authKey, privProtocol, privKey);
}
/**
* Sets the user's security name and authentication/privacy keys and protocols on the supplied
* {@link DirectUserTarget} and returns the maximum {@link SecurityLevel} it can be used with.
* @param directUserTarget
* the direct user target to be modified. Security name is set always and authentication protocol and key only
* if provided in the given {@code localizedUserCredentials} and if the authentication protocol is available
* from {@link #getMPv3()}#getAuthenticationProtocol}. The privacy key and protocol are set only if
* provided the authentication could be set and if the privacy key is set in {@code localizedUserCredentials}
* protocol is available from {@link #getMPv3()}#getPrivacyProtocol}
* @param localizedUserCredentials
* a {@link UsmUserEntry} preferably created by
* {@link #createLocalizedUsmUserEntry(byte[], OctetString, OID, OctetString, OID, OctetString)} that must
* contain already localized keys (or no keys at all).
* @return
* the maximum {@link SecurityLevel} the modified {@link DirectUserTarget} directUserTarget now supports.
* @since 3.4.0
*/
public SecurityLevel setLocalizedUserCredentials(DirectUserTarget directUserTarget,
UsmUserEntry localizedUserCredentials) {
MPv3 mPv3 = getMPv3();
SecurityLevel securityLevel = SecurityLevel.noAuthNoPriv;
directUserTarget.setSecurityName(localizedUserCredentials.getUserName());
if (localizedUserCredentials.getAuthenticationKey() != null) {
AuthenticationProtocol authenticationProtocol =
mPv3.getAuthProtocol(localizedUserCredentials.getUsmUser().getAuthenticationProtocol());
if (authenticationProtocol != null) {
directUserTarget.setAuthenticationProtocol(authenticationProtocol);
directUserTarget.setAuthenticationKey(new OctetString(localizedUserCredentials.getAuthenticationKey()));
securityLevel = SecurityLevel.authNoPriv;
if (localizedUserCredentials.getPrivacyKey() != null) {
PrivacyProtocol privacyProtocol =
mPv3.getPrivProtocol(localizedUserCredentials.getUsmUser().getPrivacyProtocol());
if (privacyProtocol != null) {
directUserTarget.setPrivacyProtocol(privacyProtocol);
directUserTarget.setPrivacyKey(new OctetString(localizedUserCredentials.getPrivacyKey()));
securityLevel = SecurityLevel.authPriv;
}
}
}
}
directUserTarget.setSecurityLevel(securityLevel.getSnmpValue());
return securityLevel;
}
protected class PendingRequest extends TimerTask implements PduHandleCallback, Cloneable {
private PduHandle key;
protected int retryCount;
protected ResponseListener listener;
protected Object userObject;
protected PDU pdu;
protected Target target;
protected TransportMapping transport;
private int requestStatus = 0;
// Maximum request status - allows receiving up to two reports and then
// send the original request again. A value of 0 is used for discovery.
private int maxRequestStatus = DEFAULT_MAX_REQUEST_STATUS;
private volatile boolean finished = false;
private volatile boolean responseReceived = false;
private volatile boolean pendingRetry = false;
private volatile boolean cancelled = false;
private CounterEvent waitTime;
private CounterEvent waitTimeTarget;
/**
* The {@code nextPDU} field holds a PDU that has to be sent when the response of the {@code pdu} has been
* received. Usually, this is used for (context) engine ID discovery.
*/
private PDU nextPDU;
public PendingRequest(ResponseListener listener,
Object userObject,
PDU pdu,
Target target,
TransportMapping transport) {
this.userObject = userObject;
this.listener = listener;
this.retryCount = target.getRetries();
this.pdu = pdu;
this.target = target.duplicate();
this.transport = transport;
if (SNMP4JSettings.getSnmp4jStatistics() != SNMP4JSettings.Snmp4jStatistics.none) {
waitTime = new CounterEvent(this, SnmpConstants.snmp4jStatsRequestWaitTime, System.nanoTime());
if (SNMP4JSettings.getSnmp4jStatistics() == SNMP4JSettings.Snmp4jStatistics.extended) {
waitTimeTarget =
new CounterEvent(Snmp.this, SnmpConstants.snmp4jStatsReqTableWaitTime,
target.getAddress(), System.nanoTime());
}
}
if (isEmptyContextEngineID(pdu)) {
OctetString contextEngineID = contextEngineIDs.get(target.getAddress());
if (contextEngineID != null) {
((ScopedPDU) pdu).setContextEngineID(contextEngineID);
} else if (!contextEngineIdDiscoveryDisabled) {
discoverContextEngineID();
}
}
}
private PendingRequest(PendingRequest other) {
this.userObject = other.userObject;
this.listener = other.listener;
this.retryCount = other.retryCount - 1;
this.pdu = other.pdu;
this.target = other.target;
this.requestStatus = other.requestStatus;
this.responseReceived = other.responseReceived;
this.transport = other.transport;
this.nextPDU = other.nextPDU;
this.waitTime = other.waitTime;
}
private void discoverContextEngineID() {
MessageProcessingModel mp = messageDispatcher.getMessageProcessingModel(target.getVersion());
if ((mp instanceof MPv3) && (target instanceof SecureTarget)) {
MPv3 mpv3 = (MPv3) mp;
SecureTarget st = (SecureTarget) target;
SecurityModel sm = mpv3.getSecurityModel(st.getSecurityModel());
if ((sm != null) && (!sm.supportsEngineIdDiscovery())) {
// Perform context engine ID discovery according to RFC 5343
if (logger.isInfoEnabled()) {
logger.info("Performing RFC 5343 contextEngineID discovery on " + target);
}
ScopedPDU discoverPDU = new ScopedPDU();
discoverPDU.setContextEngineID(MPv3.LOCAL_ENGINE_ID);
discoverPDU.add(new VariableBinding(SnmpConstants.snmpEngineID));
insertFirstPDU(discoverPDU);
}
}
}
protected void registerRequest(PduHandle handle) {
// overwritten by subclasses
}
public boolean useNextPDU() {
if (nextPDU != null) {
pdu = nextPDU;
nextPDU = null;
return true;
}
return false;
}
public void insertFirstPDU(PDU firstPDU) {
nextPDU = this.pdu;
this.pdu = firstPDU;
}
public void responseReceived() {
this.responseReceived = true;
if (waitTime != null) {
CounterSupport counterSupport = getCounterSupport();
if (counterSupport != null) {
long increment = (System.nanoTime() - waitTime.getIncrement()) / SnmpConstants.MILLISECOND_TO_NANOSECOND;
waitTime.setIncrement(increment);
counterSupport.fireIncrementCounter(waitTime);
if (waitTimeTarget != null) {
waitTimeTarget.setIncrement(increment);
counterSupport.fireIncrementCounter(waitTimeTarget);
}
}
}
}
public PDU getNextPDU() {
return nextPDU;
}
public void setNextPDU(PDU nextPDU) {
this.nextPDU = nextPDU;
}
@Override
public Object clone() throws CloneNotSupportedException {
return super.clone();
}
public synchronized void pduHandleAssigned(PduHandle handle, PDU pdu) {
if (key == null) {
key = handle;
// get pointer to target before adding request to pending list
// to make sure that this retry is not being cancelled before we
// got the target pointer.
Target t = target;
if ((t != null) && (!cancelled)) {
pendingRequests.put(handle, this);
registerRequest(handle);
if (logger.isDebugEnabled()) {
logger.debug("Running pending " +
((listener instanceof SyncResponseListener) ?
"sync" : "async") +
" request with handle " + handle +
" and retry count left " + retryCount);
}
long delay =
timeoutModel.getRetryTimeout(t.getRetries() - retryCount,
t.getRetries(),
t.getTimeout());
if ((!finished) && (!responseReceived) && (!cancelled)) {
try {
CommonTimer timerCopy = timer;
if (timerCopy != null) {
timerCopy.schedule(this, delay);
}
// pending request will be removed by the close() call
} catch (IllegalStateException isex) {
// ignore
}
} else {
pendingRequests.remove(handle);
}
}
}
}
/**
* Process retries of a pending request.
*/
public synchronized void run() {
PduHandle m_key = key;
PDU m_pdu = pdu;
Target m_target = target;
TransportMapping m_transport = transport;
ResponseListener m_listener = listener;
Object m_userObject = userObject;
if ((m_key == null) || (m_pdu == null) || (m_target == null) ||
(m_listener == null)) {
if (logger.isDebugEnabled()) {
logger.debug("PendingRequest canceled key=" + m_key + ", pdu=" + m_pdu +
", target=" + m_target + ", transport=" + m_transport + ", listener=" +
m_listener);
}
return;
}
try {
synchronized (pendingRequests) {
this.pendingRetry = (!finished) && (retryCount > 0) && (!responseReceived);
}
if (this.pendingRetry) {
try {
PendingRequest nextRetry = new PendingRequest<>(this);
sendMessage(m_pdu, m_target, m_transport, nextRetry);
this.pendingRetry = false;
if (waitTime != null) {
CounterSupport counterSupport = getCounterSupport();
if (counterSupport != null) {
counterSupport.fireIncrementCounter(
new CounterEvent(Snmp.this, SnmpConstants.snmp4jStatsRequestRetries));
if (SNMP4JSettings.getSnmp4jStatistics() == SNMP4JSettings.Snmp4jStatistics.extended) {
counterSupport.fireIncrementCounter(
new CounterEvent(Snmp.this, SnmpConstants.snmp4jStatsReqTableRetries, m_target.getAddress(), 1));
}
}
}
} catch (IOException ex) {
finished = true;
logger.error("Failed to send SNMP message to " + m_target + ": " + ex.getMessage());
messageDispatcher.releaseStateReference(m_target.getVersion(), m_key);
m_listener.onResponse(new ResponseEvent(Snmp.this, null,
m_pdu, null, m_userObject, ex));
}
} else if (!finished) {
finished = true;
pendingRequests.remove(m_key);
if (!cancelled) {
// request timed out
if (logger.isDebugEnabled()) {
logger.debug("Request timed out: " + m_key.getTransactionID());
}
messageDispatcher.releaseStateReference(m_target.getVersion(), m_key);
m_listener.onResponse(new ResponseEvent(Snmp.this, null,
m_pdu, null, m_userObject));
}
} else {
// make sure pending request is removed even if response listener
// failed to call Snmp.cancel
pendingRequests.remove(m_key);
}
} catch (RuntimeException ex) {
logger.error("Failed to process pending request " + m_key +
" because " + ex.getMessage(), ex);
} catch (Error er) {
logger.fatal("Failed to process pending request " + m_key +
" because " + er.getMessage(), er);
}
}
public boolean setFinished() {
boolean currentState = finished;
this.finished = true;
return currentState;
}
public void setMaxRequestStatus(int maxRequestStatus) {
this.maxRequestStatus = maxRequestStatus;
}
public int getMaxRequestStatus() {
return maxRequestStatus;
}
public boolean isResponseReceived() {
return responseReceived;
}
/**
* Cancels the request and clears all internal fields by setting them to {@code null}.
*
* @return {@code true} if cancellation was successful.
*/
public boolean cancel() {
cancelled = true;
boolean result = super.cancel();
Target m_target = target;
if (waitTime != null && !isResponseReceived()) {
CounterSupport counterSupport = getCounterSupport();
if (counterSupport != null) {
counterSupport.fireIncrementCounter(
new CounterEvent(Snmp.this, SnmpConstants.snmp4jStatsRequestTimeouts));
if (SNMP4JSettings.getSnmp4jStatistics() == SNMP4JSettings.Snmp4jStatistics.extended && (m_target != null)) {
counterSupport.fireIncrementCounter(
new CounterEvent(Snmp.this, SnmpConstants.snmp4jStatsReqTableTimeouts, m_target.getAddress(), 1));
}
}
}
// free objects early
if (!pendingRetry) {
key = null;
pdu = null;
target = null;
transport = null;
listener = null;
userObject = null;
}
return result;
}
}
class AsyncPendingRequest extends PendingRequest {
public AsyncPendingRequest(ResponseListener listener, Object userObject, PDU pdu, Target target,
TransportMapping transport) {
super(listener, userObject, pdu, target, transport);
}
protected void registerRequest(PduHandle handle) {
AsyncRequestKey key = new AsyncRequestKey(super.pdu, super.listener);
asyncRequests.put(key, handle);
}
}
static class AsyncRequestKey {
private PDU request;
private ResponseListener listener;
public AsyncRequestKey(PDU request, ResponseListener listener) {
this.request = request;
this.listener = listener;
}
/**
* Indicates whether some other object is "equal to" this one.
*
* @param obj
* the reference object with which to compare.
*
* @return {@code true} if this object is the same as the obj argument; {@code false} otherwise.
*/
public boolean equals(Object obj) {
if (obj instanceof AsyncRequestKey) {
AsyncRequestKey other = (AsyncRequestKey) obj;
return (request.equals(other.request) && listener.equals(other.listener));
}
return false;
}
public int hashCode() {
return request.hashCode();
}
}
static class SyncResponseListener implements ResponseListener {
private ResponseEvent response = null;
@SuppressWarnings("unchecked")
public synchronized void onResponse(ResponseEvent event) {
this.response = (ResponseEvent) event;
this.notify();
}
public ResponseEvent getResponse() {
return response;
}
}
/**
* The {@code NotificationDispatcher} dispatches traps, notifications, and to registered listeners.
*
* @author Frank Fock
* @version 2.5.0
* @since 1.6
*/
public class NotificationDispatcher implements CommandResponder {
// A mapping of transport addresses to transport mappings of notification
// listeners
private Hashtable> notificationListeners = new Hashtable<>(10);
private Hashtable, CommandResponder> notificationTransports = new Hashtable<>(10);
protected NotificationDispatcher() {
}
public TransportMapping getTransportMapping(Address listenAddress) {
return notificationListeners.get(listenAddress);
}
public synchronized void addNotificationListener(Address listenAddress,
TransportMapping transport,
CommandResponder listener) {
notificationListeners.put(listenAddress, transport);
notificationTransports.put(transport, listener);
}
public synchronized boolean
removeNotificationListener(Address listenAddress) {
TransportMapping tm = notificationListeners.remove(listenAddress);
if (tm == null) {
return false;
}
tm.removeTransportListener(messageDispatcher);
notificationTransports.remove(tm);
closeTransportMapping(tm);
return true;
}
public synchronized void closeAll() {
notificationTransports.clear();
for (TransportMapping tm : notificationListeners.values()) {
closeTransportMapping(tm);
}
notificationListeners.clear();
}
public void processPdu(CommandResponderEvent event) {
CommandResponder listener;
synchronized (this) {
listener = notificationTransports.get(event.getTransportMapping());
}
if ((event.getPDU() != null) && (event.getPDU().getType() == PDU.INFORM)) {
// try to send INFORM response
try {
sendInformResponse(event);
} catch (MessageException mex) {
if (logger.isWarnEnabled()) {
logger.warn("Failed to send response on INFORM PDU event (" +
event + "): " + mex.getMessage());
}
}
}
if (listener != null) {
listener.processPdu(event);
}
}
/**
* Sends a RESPONSE PDU to the source address of a INFORM request.
*
* @param event
* the {@code CommandResponderEvent} with the INFORM request.
*
* @throws MessageException
* if the response could not be created and sent.
*/
protected void sendInformResponse(CommandResponderEvent event) throws
MessageException {
PDU responsePDU = (PDU) event.getPDU().clone();
responsePDU.setType(PDU.RESPONSE);
responsePDU.setErrorStatus(PDU.noError);
responsePDU.setErrorIndex(0);
messageDispatcher.returnResponsePdu(event.getMessageProcessingModel(),
event.getSecurityModel(),
event.getSecurityName(),
event.getSecurityLevel(),
responsePDU,
event.getMaxSizeResponsePDU(),
event.getStateReference(),
new StatusInformation());
}
}
protected void closeTransportMapping(TransportMapping tm) {
try {
tm.close();
} catch (IOException ex) {
logger.error("Failed to close transport " + tm + ": " + ex.getMessage(), ex);
if (logger.isDebugEnabled()) {
ex.printStackTrace();
}
}
}
}