1 /*
   2  * Copyright (c) 1998, 2007, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 
  27 package com.sun.jmx.snmp;
  28 
  29 
  30 
  31 
  32 /**
  33  * Defines the interface of the object in charge of encoding and decoding SNMP packets.
  34  * <P>
  35  * You will not usually need to use this interface, except if you
  36  * decide to replace the default implementation <CODE>SnmpPduFactoryBER</CODE>.
  37  * <P>
  38  * An <CODE>SnmpPduFactory</CODE> object is attached to an
  39  * {@link com.sun.jmx.snmp.daemon.SnmpAdaptorServer SNMP protocol adaptor}
  40  * or an {@link com.sun.jmx.snmp.SnmpPeer SnmpPeer}.
  41  * It is used each time an SNMP packet needs to be encoded or decoded.
  42  * <BR>{@link com.sun.jmx.snmp.SnmpPduFactoryBER SnmpPduFactoryBER} is the default
  43  * implementation.
  44  * It simply applies the standard ASN.1 encoding and decoding
  45  * on the bytes of the SNMP packet.
  46  * <P>
  47  * It's possible to implement your own <CODE>SnmpPduFactory</CODE>
  48  * object and to add authentication and/or encryption to the
  49  * default encoding/decoding process.
  50  *
  51  * <p><b>This API is a Sun Microsystems internal API  and is subject
  52  * to change without notice.</b></p>
  53  * @see SnmpPduFactory
  54  * @see SnmpPduPacket
  55  * @see SnmpMessage
  56  *
  57  */
  58 
  59 public interface SnmpPduFactory {
  60 
  61     /**
  62      * Decodes the specified <CODE>SnmpMsg</CODE> and returns the
  63      * resulting <CODE>SnmpPdu</CODE>. If this method returns
  64      * <CODE>null</CODE>, the message will be considered unsafe
  65      * and will be dropped.
  66      *
  67      * @param msg The <CODE>SnmpMsg</CODE> to be decoded.
  68      * @return Null or a fully initialized <CODE>SnmpPdu</CODE>.
  69      * @exception SnmpStatusException If the encoding is invalid.
  70      *
  71      * @since 1.5
  72      */
  73     public SnmpPdu decodeSnmpPdu(SnmpMsg msg) throws SnmpStatusException ;
  74 
  75     /**
  76      * Encodes the specified <CODE>SnmpPdu</CODE> and
  77      * returns the resulting <CODE>SnmpMsg</CODE>. If this
  78      * method returns null, the specified <CODE>SnmpPdu</CODE>
  79      * will be dropped and the current SNMP request will be
  80      * aborted.
  81      *
  82      * @param p The <CODE>SnmpPdu</CODE> to be encoded.
  83      * @param maxDataLength The size limit of the resulting encoding.
  84      * @return Null or a fully encoded <CODE>SnmpMsg</CODE>.
  85      * @exception SnmpStatusException If <CODE>pdu</CODE> contains
  86      *            illegal values and cannot be encoded.
  87      * @exception SnmpTooBigException If the resulting encoding does not
  88      *            fit into <CODE>maxPktSize</CODE> bytes.
  89      *
  90      * @since 1.5
  91      */
  92     public SnmpMsg encodeSnmpPdu(SnmpPdu p, int maxDataLength)
  93         throws SnmpStatusException, SnmpTooBigException ;
  94 }