Beispiel #1
0
  /**
   * Decodes a <code>Variable</code> from an <code>InputStream</code>.
   *
   * @param inputStream an <code>InputStream</code> containing a BER encoded byte stream.
   * @throws IOException
   */
  @Override
  public void decodeBER(BERInputStream inputStream) throws IOException {
    MutableByte pduType = new MutableByte();
    int length = BER.decodeHeader(inputStream, pduType);
    int pduStartPos = (int) inputStream.getPosition();

    switch (pduType.getValue()) {
      case PDU.SET:
      case PDU.GET:
      case PDU.GETNEXT:
      case PDU.V1TRAP:
      case PDU.RESPONSE:
        break;
        // The following PDU types are not supported by the SNMPv1 standard!
      case PDU.NOTIFICATION:
      case PDU.INFORM:
        if (SNMP4JSettings.isAllowSNMPv2InV1()) {
          break;
        }
        // fall through
      default:
        throw new IOException("Unsupported PDU type: " + pduType.getValue());
    }
    this.setType(pduType.getValue());
    if (getType() == PDU.V1TRAP) {
      enterprise.decodeBER(inputStream);
      agentAddress.decodeBER(inputStream);
      genericTrap.decodeBER(inputStream);
      specificTrap.decodeBER(inputStream);
      timestamp.decodeBER(inputStream);
    } else {
      requestID.decodeBER(inputStream);
      errorStatus.decodeBER(inputStream);
      errorIndex.decodeBER(inputStream);
    }
    // reusing pduType here to save memory ;-)
    pduType = new BER.MutableByte();
    int vbLength = BER.decodeHeader(inputStream, pduType);
    if (pduType.getValue() != BER.SEQUENCE) {
      throw new IOException("Encountered invalid tag, SEQUENCE expected: " + pduType.getValue());
    }
    // rest read count
    int startPos = (int) inputStream.getPosition();
    variableBindings = new Vector<>();
    while (inputStream.getPosition() - startPos < vbLength) {
      VariableBinding vb = new VariableBinding();
      vb.decodeBER(inputStream);
      if (!isVariableV1(vb.getVariable())) {
        throw new MessageException("Counter64 encountered in SNMPv1 PDU " + "(RFC 2576 §4.1.2.1)");
      }
      variableBindings.add(vb);
    }
    if (BER.isCheckSequenceLength()) {
      BER.checkSequenceLength(vbLength, (int) inputStream.getPosition() - startPos, this);
      BER.checkSequenceLength(length, (int) inputStream.getPosition() - pduStartPos, this);
    }
  }
Beispiel #2
0
 /**
  * Check if the given variable can be encoded into a SNMPv1 PDU.
  *
  * @param v a variable value (must not be <code>null</code>).
  * @return <code>true</code> if the variable is SNMPv1 compatible (or {@link
  *     org.snmp4j.SNMP4JSettings#isAllowSNMPv2InV1()} is true), <code>false</code> otherwise, i.e.
  *     if <code>v</code> is an instance of {@link Counter64}.
  * @since 1.9.1c
  */
 protected boolean isVariableV1(Variable v) {
   return !(v instanceof Counter64) || SNMP4JSettings.isAllowSNMPv2InV1();
 }