/* * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.jmx.snmp.agent; // java imports // import java.io.Serializable; import java.util.Hashtable; import java.util.Vector; // jmx imports // import com.sun.jmx.snmp.SnmpVarBind; import com.sun.jmx.snmp.SnmpStatusException; /** * Represents a node in an SNMP MIB which corresponds to a group. * This class allows subnodes to be registered below a group, providing * support for nested groups. The subnodes are registered at run time * when registering the nested groups in the global MIB OID tree. *

* This class is used by the class generated by mibgen. * You should not need to use this class directly. * *

This API is a Sun Microsystems internal API and is subject * to change without notice.

*/ @SuppressWarnings("serial") // JDK implementation class public abstract class SnmpMibGroup extends SnmpMibOid implements Serializable { // We will register the OID arcs leading to subgroups in this hashtable. // So for each arc in varList, if the arc is also in subgroups, it leads // to a subgroup, if it is not in subgroup, it leads either to a table // or to a variable. protected Hashtable subgroups = null; /** * Tells whether the given arc identifies a table in this group. * * @param arc An OID arc. * * @return true if `arc' leads to a table. */ public abstract boolean isTable(long arc); /** * Tells whether the given arc identifies a variable (scalar object) in * this group. * * @param arc An OID arc. * * @return true if `arc' leads to a variable. */ public abstract boolean isVariable(long arc); /** * Tells whether the given arc identifies a readable scalar object in * this group. * * @param arc An OID arc. * * @return true if `arc' leads to a readable variable. */ public abstract boolean isReadable(long arc); /** * Gets the table identified by the given `arc'. * * @param arc An OID arc. * * @return The SnmpMibTable identified by `arc', or * null if `arc' does not identify any table. */ public abstract SnmpMibTable getTable(long arc); /** * Checks whether the given OID arc identifies a variable (scalar * object). * * @exception If the given `arc' does not identify any variable in this * group, throws an SnmpStatusException. */ public void validateVarId(long arc, Object userData) throws SnmpStatusException { if (isVariable(arc) == false) { throw new SnmpStatusException(SnmpStatusException.noSuchObject); } } // ------------------------------------------------------------------- // We use a hashtable (subgroup) in order to determine whether an // OID arc leads to a subgroup. This implementation can be changed if // needed... // For instance, the subclass could provide a generated isNestedArc() // method in which the subgroup OID arcs would be hardcoded. // However, the generic approach was preferred because at this time // groups and subgroups are dynamically registered in the MIB. // /** * Tell whether the given OID arc identifies a sub-tree * leading to a nested SNMP sub-group. This method is used internally. * You shouldn't need to call it directly. * * @param arc An OID arc. * * @return true if the given OID arc identifies a subtree * leading to a nested SNMP sub-group. * */ public boolean isNestedArc(long arc) { if (subgroups == null) return false; Object obj = subgroups.get(arc); // if the arc is registered in the hashtable, // it leads to a subgroup. return (obj != null); } /** * Generic handling of the get operation. *

The actual implementation of this method will be generated * by mibgen. Usually, this implementation only delegates the * job to some other provided runtime class, which knows how to * access the MBean. The current toolkit thus provides two * implementations: *

*

Both implementations rely upon specific - and distinct, set of * mibgen generated methods. *

You can override this method if you need to implement some * specific policies for minimizing the accesses made to some remote * underlying resources. *

* * @param req The sub-request that must be handled by this node. * * @param depth The depth reached in the OID tree. * * @exception SnmpStatusException An error occurred while accessing * the MIB node. */ @Override abstract public void get(SnmpMibSubRequest req, int depth) throws SnmpStatusException; /** * Generic handling of the set operation. *

The actual implementation of this method will be generated * by mibgen. Usually, this implementation only delegates the * job to some other provided runtime class, which knows how to * access the MBean. The current toolkit thus provides two * implementations: *

*

Both implementations rely upon specific - and distinct, set of * mibgen generated methods. *

You can override this method if you need to implement some * specific policies for minimizing the accesses made to some remote * underlying resources. *

* * @param req The sub-request that must be handled by this node. * * @param depth The depth reached in the OID tree. * * @exception SnmpStatusException An error occurred while accessing * the MIB node. */ @Override abstract public void set(SnmpMibSubRequest req, int depth) throws SnmpStatusException; /** * Generic handling of the check operation. * *

The actual implementation of this method will be generated * by mibgen. Usually, this implementation only delegates the * job to some other provided runtime class, which knows how to * access the MBean. The current toolkit thus provides two * implementations: *

*

Both implementations rely upon specific - and distinct, set of * mibgen generated methods. *

You can override this method if you need to implement some * specific policies for minimizing the accesses made to some remote * underlying resources, or if you need to implement some consistency * checks between the different values provided in the varbind list. *

* * @param req The sub-request that must be handled by this node. * * @param depth The depth reached in the OID tree. * * @exception SnmpStatusException An error occurred while accessing * the MIB node. */ @Override abstract public void check(SnmpMibSubRequest req, int depth) throws SnmpStatusException; // -------------------------------------------------------------------- // If we reach this node, we are below the root OID, so we just // return. // -------------------------------------------------------------------- @Override public void getRootOid(Vector result) { } // ------------------------------------------------------------------- // PACKAGE METHODS // ------------------------------------------------------------------- // ------------------------------------------------------------------- // This method can also be overriden in a subclass to provide a // different implementation of the isNestedArc() method. // => if isNestedArc() is hardcoded, then registerSubArc() becomes // useless and can become empty. /** * Register an OID arc that identifies a sub-tree * leading to a nested SNMP sub-group. This method is used internally. * You shouldn't ever call it directly. * * @param arc An OID arc. * */ void registerNestedArc(long arc) { Long obj = arc; if (subgroups == null) subgroups = new Hashtable<>(); // registers the arc in the hashtable. subgroups.put(obj,obj); } // ------------------------------------------------------------------- // The SnmpMibOid algorithm relies on the fact that for every arc // registered in varList, there is a corresponding node at the same // position in children. // So the trick is to register a null node in children for each variable // in varList, so that the real subgroup nodes can be inserted at the // correct location. // registerObject() should be called for each scalar object and each // table arc by the generated subclass. /** * Register an OID arc that identifies a scalar object or a table. * This method is used internally. You shouldn't ever call it directly. * * @param arc An OID arc. * */ protected void registerObject(long arc) throws IllegalAccessException { // this will register the variable in both varList and children // The node registered in children will be null, so that the parent // algorithm will behave as if no node were registered. This is a // trick that makes the parent algorithm behave as if only subgroups // were registered in varList and children. long[] oid = new long[1]; oid[0] = arc; super.registerNode(oid,0,null); } // ------------------------------------------------------------------- // registerNode() will be called at runtime when nested groups are // registered in the MIB. So we do know that this method will only // be called to register nested-groups. // We trap registerNode() in order to call registerSubArc() /** * Register a child node of this node in the OID tree. * This method is used internally. You shouldn't ever call it directly. * * @param oid The oid of the node being registered. * @param cursor The position reached in the oid. * @param node The node being registered. * */ @Override void registerNode(long[] oid, int cursor ,SnmpMibNode node) throws IllegalAccessException { super.registerNode(oid,cursor,node); if (cursor < 0) return; if (cursor >= oid.length) return; // if we get here, then it means we are registering a subgroup. // We will thus register the sub arc in the subgroups hashtable. registerNestedArc(oid[cursor]); } // ------------------------------------------------------------------- // see comments in SnmpMibNode // ------------------------------------------------------------------- @Override void findHandlingNode(SnmpVarBind varbind, long[] oid, int depth, SnmpRequestTree handlers) throws SnmpStatusException { int length = oid.length; if (handlers == null) throw new SnmpStatusException(SnmpStatusException.snmpRspGenErr); final Object data = handlers.getUserData(); if (depth >= length) { // Nothing is left... the oid is not valid throw new SnmpStatusException(SnmpStatusException.noAccess); } long arc = oid[depth]; if (isNestedArc(arc)) { // This arc leads to a subgroup: delegates the search to the // method defined in SnmpMibOid super.findHandlingNode(varbind,oid,depth,handlers); } else if (isTable(arc)) { // This arc leads to a table: forward the search to the table. // Gets the table SnmpMibTable table = getTable(arc); // Forward the search to the table table.findHandlingNode(varbind,oid,depth+1,handlers); } else { // If it's not a variable, throws an exception validateVarId(arc, data); // The trailing .0 is missing in the OID if (depth+2 > length) { throw new SnmpStatusException(SnmpStatusException.noSuchInstance); } // There are too many arcs left in the OID (there should remain // a single trailing .0) if (depth+2 < length) { throw new SnmpStatusException(SnmpStatusException.noSuchInstance); } // The last trailing arc is not .0 if (oid[depth+1] != 0L) { throw new SnmpStatusException(SnmpStatusException.noSuchInstance); } // It's one of our variable, register this node. handlers.add(this,depth,varbind); } } // ------------------------------------------------------------------- // See comments in SnmpMibNode. // ------------------------------------------------------------------- @Override long[] findNextHandlingNode(SnmpVarBind varbind, long[] oid, int pos, int depth, SnmpRequestTree handlers, AcmChecker checker) throws SnmpStatusException { int length = oid.length; SnmpMibNode node = null; if (handlers == null) { // This should be considered as a genErr, but we do not want to // abort the whole request, so we're going to throw // a noSuchObject... // throw new SnmpStatusException(SnmpStatusException.noSuchObject); } final Object data = handlers.getUserData(); final int pduVersion = handlers.getRequestPduVersion(); // The generic case where the end of the OID has been reached is // handled in the superclass // XXX Revisit: this works but it is somewhat convoluted. Just setting // arc to -1 would work too. if (pos >= length) return super.findNextHandlingNode(varbind,oid,pos,depth, handlers, checker); // Ok, we've got the arc. long arc = oid[pos]; long[] result = null; // We have a recursive logic. Should we have a loop instead? try { if (isTable(arc)) { // If the arc identifies a table, then we need to forward // the search to the table. // Gets the table identified by `arc' SnmpMibTable table = getTable(arc); // Forward to the table checker.add(depth, arc); try { result = table.findNextHandlingNode(varbind,oid,pos+1, depth+1,handlers, checker); }catch(SnmpStatusException ex) { throw new SnmpStatusException(SnmpStatusException.noSuchObject); } finally { checker.remove(depth); } // Build up the leaf OID result[depth] = arc; return result; } else if (isReadable(arc)) { // If the arc identifies a readable variable, then two cases: if (pos == (length - 1)) { // The end of the OID is reached, so we return the leaf // corresponding to the variable identified by `arc' // Build up the OID // result = new SnmpOid(0); // result.insert((int)arc); result = new long[depth+2]; result[depth+1] = 0L; result[depth] = arc; checker.add(depth, result, depth, 2); try { checker.checkCurrentOid(); } catch(SnmpStatusException e) { throw new SnmpStatusException(SnmpStatusException.noSuchObject); } finally { checker.remove(depth,2); } // Registers this node handlers.add(this,depth,varbind); return result; } // The end of the OID is not yet reached, so we must return // the next leaf following the variable identified by `arc'. // We cannot return the variable because whatever follows in // the OID will be greater or equals to 0, and 0 identifies // the variable itself - so we have indeed to return the // next object. // So we do nothing, because this case is handled at the // end of the if ... else if ... else ... block. } else if (isNestedArc(arc)) { // Now if the arc leads to a subgroup, we delegate the // search to the child, just as done in SnmpMibNode. // // get the child ( = nested arc node). // final SnmpMibNode child = getChild(arc); if (child != null) { checker.add(depth, arc); try { result = child.findNextHandlingNode(varbind,oid,pos+1, depth+1,handlers, checker); result[depth] = arc; return result; } finally { checker.remove(depth); } } } // The oid is not valid, we will throw an exception in order // to try with the next valid identifier... // throw new SnmpStatusException(SnmpStatusException.noSuchObject); } catch (SnmpStatusException e) { // We didn't find anything at the given arc, so we're going // to try with the next valid arc // long[] newOid = new long[1]; newOid[0] = getNextVarId(arc,data,pduVersion); return findNextHandlingNode(varbind,newOid,0,depth, handlers,checker); } } }