org.snmp4j.agent.mo.snmp4j.MOSubtreeProxy Maven / Gradle / Ivy
/*_############################################################################
_##
_## SNMP4J-Agent 3 - MOSubtreeProxy.java
_##
_## Copyright (C) 2005-2021 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.agent.mo.snmp4j;
import org.snmp4j.*;
import org.snmp4j.agent.*;
import org.snmp4j.agent.mo.GenericManagedObject;
import org.snmp4j.agent.mo.MOAccessImpl;
import org.snmp4j.agent.mo.snmp.SnmpTargetMIB;
import org.snmp4j.agent.request.SubRequest;
import org.snmp4j.agent.util.OIDTranslation;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.log.LogAdapter;
import org.snmp4j.log.LogFactory;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.util.DefaultPDUFactory;
import org.snmp4j.util.PDUFactory;
import java.io.IOException;
/**
* In contrast to {@link org.snmp4j.agent.ProxyForwarder}, the MOSubtreeProxy provides a proxy implementation for a
* single subtree based on the configuration provided by the {@link org.snmp4j.agent.mo.snmp4j.Snmp4jProxyMib} {@link
* org.snmp4j.agent.mo.snmp.SnmpProxyMIB} and {@link org.snmp4j.agent.mo.snmp.SnmpTargetMIB}.
*
* @author Frank Fock
* @version 3.2
* @since 2.0
*/
public class MOSubtreeProxy implements GenericManagedObject {
private static final LogAdapter logger = LogFactory.getLogger(MOSubtreeProxy.class);
private Session session;
private SnmpTargetMIB targetMIB;
private OctetString proxyName;
private OctetString contextName;
private OctetString contextEngineID;
private DefaultMOScope scope;
private OctetString targetName;
private MOAccess access = MOAccessImpl.ACCESS_READ_WRITE;
private OIDTranslation translation;
private boolean undoEnabled = true;
private PDUFactory pduFactory;
public MOSubtreeProxy(Session session, SnmpTargetMIB targetMIB,
OctetString proxyName,
OID subtreeOID, OctetString contextEngineID,
OctetString contextName, OctetString targetName) {
this.session = session;
this.targetMIB = targetMIB;
this.proxyName = proxyName;
this.contextName = contextName;
this.scope = new DefaultMOScope(subtreeOID, true, subtreeOID.nextPeer(), false);
this.targetName = targetName;
this.contextEngineID = contextEngineID;
this.pduFactory = new DefaultPDUFactory(PDU.GETNEXT, contextEngineID, contextName);
}
@Override
public MOScope getScope() {
return scope;
}
@Override
public OID find(MOScope range) {
/*
if (translation != null) {
range = translate(range);
}
*/
if (access.isAccessibleForRead()) {
OID lowerBound = range.getLowerBound();
OID next = OID.max(((lowerBound == null) ? scope.getLowerBound() : lowerBound), scope.getLowerBound());
if (scope.covers(next)) {
return next;
}
}
return null;
}
/**
* Sets the remote sub-tree OID for the translation between local agent OID and remote agent OID. If {@code null},
* zero length, or equal to {@code 0.0}, no translation takes place.
*
* @param remoteSubtree
* the OID sub-tree of the target agent to proxy.
*/
public void setTargetSubtree(OID remoteSubtree) {
this.translation = new OIDTranslator(remoteSubtree);
}
private MOScope translate(MOScope range) {
if (translation != null) {
MOScope translated =
new DefaultMOScope(translation.forwardTranslate(scope.getLowerBound()), scope.isLowerIncluded(),
translation.forwardTranslate(scope.getUpperBound()), scope.isUpperIncluded());
return translated;
}
return range;
}
@Override
public void get(SubRequest request) {
if (!access.isAccessibleForRead()) {
request.setErrorStatus(PDU.noAccess);
return;
}
OID oid = request.getVariableBinding().getOid();
if (translation != null) {
oid = translation.forwardTranslate(oid);
}
VariableBinding vb = new VariableBinding(oid);
Target target = targetMIB.getTarget(targetName, contextEngineID, contextName);
PDU pdu = pduFactory.createPDU(target);
pdu.setType(PDU.GET);
pdu.add(vb);
try {
ResponseEvent resp = session.send(pdu, target);
if (resp.getResponse() != null) {
PDU rpdu = resp.getResponse();
if (rpdu.getErrorStatus() != PDU.noError) {
request.setErrorStatus(rpdu.getErrorStatus());
} else {
request.getVariableBinding().setVariable(resp.getResponse().getVariable(oid));
}
}
} catch (IOException e) {
logger.error("IOException in GET sub-request " + request + " to " + target, e);
}
request.completed();
}
@Override
public boolean next(SubRequest request) {
if (!access.isAccessibleForRead()) {
return false;
}
OID oid = request.getVariableBinding().getOid();
if (translation != null) {
oid = translation.forwardTranslate(oid);
}
VariableBinding vb = new VariableBinding(oid);
Target target = targetMIB.getTarget(targetName, contextEngineID, contextName);
PDU pdu = pduFactory.createPDU(target);
pdu.setType(PDU.GETNEXT);
pdu.add(vb);
try {
ResponseEvent resp = session.send(pdu, target);
if (resp.getResponse() != null) {
PDU rpdu = resp.getResponse();
if (rpdu.getErrorStatus() != PDU.noError) {
request.setErrorStatus(rpdu.getErrorStatus());
} else {
VariableBinding rvb = resp.getResponse().getVariableBindings().get(0);
OID nextOID = rvb.getOid();
if (translation != null) {
nextOID = translation.backwardTranslate(nextOID);
rvb.setOid(nextOID);
}
if (!scope.covers(nextOID)) {
return false;
}
request.getVariableBinding().setOid(rvb.getOid());
request.getVariableBinding().setVariable(rvb.getVariable());
request.completed();
return true;
}
}
} catch (IOException e) {
logger.error("IOException in NEXT sub-request " + request + " to " + target, e);
}
request.completed();
return false;
}
@Override
public void prepare(SubRequest request) {
if (undoEnabled) {
OID oid = request.getVariableBinding().getOid();
if (translation != null) {
oid = translation.forwardTranslate(oid);
}
VariableBinding vb = new VariableBinding(oid);
Target target = targetMIB.getTarget(targetName, contextEngineID, contextName);
PDU pdu = pduFactory.createPDU(target);
pdu.setType(PDU.GET);
pdu.add(vb);
try {
ResponseEvent resp = session.send(pdu, target);
if (resp.getResponse() != null) {
PDU rpdu = resp.getResponse();
if (rpdu.getErrorStatus() != PDU.noError) {
request.setErrorStatus(rpdu.getErrorStatus());
}
VariableBinding rvb = rpdu.getVariableBindings().get(0);
if ((rvb == null) || rvb.isException()) {
request.setErrorStatus(PDU.noSuchName);
} else {
request.setUndoValue(rvb);
}
}
} catch (IOException e) {
request.setErrorStatus(PDU.genErr);
logger.error("IOException in prepare SET sub-request " + request + " to " + target, e);
}
} else {
request.setUndoValue(null);
}
request.getStatus().setPhaseComplete(true);
}
@Override
public void commit(SubRequest request) {
OID oid = request.getVariableBinding().getOid();
if (translation != null) {
oid = translation.forwardTranslate(oid);
}
VariableBinding vb = new VariableBinding(oid, request.getVariableBinding().getVariable());
Target target = targetMIB.getTarget(targetName, contextEngineID, contextName);
PDU pdu = pduFactory.createPDU(target);
pdu.setType(PDU.SET);
pdu.add(vb);
try {
ResponseEvent resp = session.send(pdu, target);
if (resp.getResponse() != null) {
PDU rpdu = resp.getResponse();
if (rpdu.getErrorStatus() != PDU.noError) {
request.setErrorStatus(rpdu.getErrorStatus());
}
request.getStatus().setPhaseComplete(true);
} else {
request.setErrorStatus(PDU.genErr);
}
} catch (IOException e) {
request.setErrorStatus(PDU.genErr);
logger.error("IOException in commit SET sub-request " + request + " to " + target, e);
}
}
@Override
public void undo(SubRequest request) {
VariableBinding vb = (VariableBinding) request.getUndoValue();
if (vb != null) {
Target target = targetMIB.getTarget(targetName, contextEngineID, contextName);
PDU pdu = pduFactory.createPDU(target);
pdu.setType(PDU.SET);
pdu.add(vb);
try {
ResponseEvent resp = session.send(pdu, target);
if (resp.getResponse() != null) {
PDU rpdu = resp.getResponse();
if (rpdu.getErrorStatus() != PDU.noError) {
request.setErrorStatus(PDU.undoFailed);
logger.warn("Undo failed because target '" + target + "' returned error " + rpdu.getErrorStatusText());
}
} else {
request.setErrorStatus(PDU.genErr);
}
} catch (IOException e) {
request.setErrorStatus(PDU.genErr);
logger.error("IOException in undo SET sub-request " + request + " to " + target, e);
}
} else if (undoEnabled) {
request.setErrorStatus(PDU.undoFailed);
}
request.getStatus().setPhaseComplete(true);
}
@Override
public void cleanup(SubRequest request) {
request.setUndoValue(null);
request.getStatus().setPhaseComplete(true);
}
/**
* Returns whether undo of SET operations should be supported by this sub-tree proxy or not. If true is
* returned, a GET requests will be sent to the target SNMP entity before the SET operation to retrieve the old
* (undo) value. If the SET operation fails because of some error in this sub-request or any other sub-request of
* the same SNMP PDU, the already SET value in the target will be reset to the old value.
*
* @return true if undo values will be retrieved for this sub-tree (default),
* false otherwise (SET requests will be committed directly without previous GET).
* @since 2.5.0
*/
public boolean isUndoEnabled() {
return undoEnabled;
}
/**
* Enables or disables undo support for SET operations. If set to true, a GET requests will be sent to
* the target SNMP entity before the SET operation to retrieve the old (undo) value. If the SET operation fails
* because of some error in this sub-request or any other sub-request of the same SNMP PDU, the already SET value in
* the target will be reset to the old value.
*
* @param undoEnabled
* true if undo values should be retrieved for this sub-tree (default),
* false otherwise (SET requests will be committed directly without previous GET).
*
* @since 2.5.0
*/
public void setUndoEnabled(boolean undoEnabled) {
this.undoEnabled = undoEnabled;
}
public OctetString getProxyName() {
return proxyName;
}
public MOAccess getAccess() {
return access;
}
public void setAccess(MOAccess access) {
this.access = access;
}
public OIDTranslation getTranslation() {
return translation;
}
/**
* Sets a OID translation. By default it is not active ({@code null}).
*
* @param translation
* If not {@code null}, the {@link OIDTranslation} can be used to map between local OID and remote OID and
* vice versa.
*/
public void setTranslation(OIDTranslation translation) {
this.translation = translation;
}
@Override
public String toString() {
return "MOSubtreeProxy[" +
"session=" + session +
", targetMIB=" + targetMIB +
", proxyName=" + proxyName +
", contextName=" + contextName +
", contextEngineID=" + contextEngineID +
", scope=" + scope +
", targetName=" + targetName +
", access=" + access +
", translation=" + translation +
", undoEnabled=" + undoEnabled +
", pduFactory=" + pduFactory +
']';
}
public class OIDTranslator implements OIDTranslation {
private OID remoteOID;
public OIDTranslator(OID remoteOID) {
this.remoteOID = remoteOID;
}
@Override
public OID forwardTranslate(OID oid) {
if (oid != null) {
OID translated;
if ((oid.size() >= scope.getLowerBound().size()) && (oid.startsWith(scope.getLowerBound()))) {
OID remote = new OID(remoteOID);
int[] suffix = new int[oid.size() - scope.getLowerBound().size()];
if (suffix.length > 0) {
System.arraycopy(oid.getValue(), scope.getLowerBound().size(), suffix, 0, suffix.length);
remote.append(new OID(suffix));
}
translated = remote;
} else if (oid.compareTo(scope.getLowerBound()) < 0) {
translated = new OID(remoteOID);
} else {
translated = remoteOID.nextPeer();
}
if (logger.isDebugEnabled()) {
logger.debug("Forward OID translation '" + oid + "'->'" + translated);
}
return translated;
}
return null;
}
@Override
public OID backwardTranslate(OID oid) {
if (oid != null) {
OID translated;
if ((oid.size() >= remoteOID.size()) && (oid.startsWith(remoteOID))) {
OID local = new OID(scope.getLowerBound());
int[] suffix = new int[oid.size() - remoteOID.size()];
if (suffix.length > 0) {
System.arraycopy(oid.getValue(), remoteOID.size(), suffix, 0, suffix.length);
local.append(new OID(suffix));
}
translated = local;
} else if (oid.compareTo(this.remoteOID) > 0) {
translated = new OID(scope.getUpperBound());
} else {
translated = new OID(scope.getUpperBound());
}
if (logger.isDebugEnabled()) {
logger.debug("Backward OID translation '" + oid + "'->'" + translated);
}
return translated;
}
return null;
}
@Override
public String toString() {
return "OIDTranslator{" +
"remoteOID=" + remoteOID +
'}';
}
}
}
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