asnobject.java

snmp zip 包开发snmp协议

                  + ", correct = " + me.isCorrect);
        }
        return me;
    }

    /** Adds a child to the sequence
     */
    AsnObject add (AsnObject child)
    {
        return child;
    }

    /** recursively look for a pduSequence object
     *  if not overridden - then not a sequence -
     */
    AsnObject findPdu()
    {
        return null;
    }

    /** recursively look for a pduSequence object
     *  if not overridden - then not a sequence -
     */
    AsnObject findTrapPduv1()
    {
        return null;
    }

    /** 
     * Output ASN header.
     */
    void AsnBuildHeader(OutputStream out, byte t, int length) 
          throws IOException
    {
        int count;

        type = t;
        // Type byte
        out.write(type);

        // Length bytes
        count = getLengthBytes(length);
        headerLength = count + 1;
        contentsLength = length;
        if (debug > 10)
        {
            System.out.println("AsnBuildHeader(): "
                + "type = 0x" + SnmpUtilities.toHex(type)
                + ", headerLength = " + headerLength
                + ", contentsLength = " + contentsLength);
        }

        if (count > 1)
        {
            // Write long form prefix byte
            --count;
            byte tmp = (byte) (0x80 | (byte) count);
            out.write(tmp);
        }
        while(count!=0)
        {
            // Write length bytes
            out.write((byte)((length >> (--count << 3)) & 0xFF));
        }
    }

    int size() throws EncodingException
    { 
        return 0; 
    }

    /** 
     * Returns length field size for a packet length.
     * Returns:
     * 1   if length will fit in short form (0x00-0x7f)
     * 2+  if length >= 0x80
     */
    int getLengthBytes(int length)
    {
        int mask, count;

        if (length < 0x80)
        {
            // Short form.. 1 byte
            return 1;
        }
        else
        {
          // Long form.. prefix byte + length bytes
          mask = 0xFF000000;
          for(count=4; (length&mask)==0; count--)
          {
              mask >>= 8;
          }
          return count+1;
        }
    }


    int getLengthPacket(InputStream in) throws IOException
    {
        int length = 0;
        byte mask =(byte) 0x7f;
        byte len = (byte) in.read();

        if ((0x80 & len) != 0)
        {
            // long form

            int count = (mask & len);
            if (count < 4)
            {
                byte data[] = new byte[count];
                int n = in.read(data, 0, count);
                if (n !=  count)
                {
                    throw new IOException("AsnObject.getLengthPacket(): Not enough data");
                } 
                else 
                {
                    /*
                     * Thanks to Julien Conan ([e-mail]) 
                     * for improving this code.
                     */
                    DataInputStream dis = new DataInputStream(
                          new ByteArrayInputStream(data));

                    for (n=0; n<count; n++)
                    {
                        length = (length << 8) + dis.readUnsignedByte();
                    }

                }
            }
        } 
        else
        {
            // short form
            length = (int) (mask & len);
        }
        return (length);
    }

    int getContentsPos()
    {
        return startPos + headerLength;
    }
    int getContentsLength()
    {
        return contentsLength;
    }

    /**
     * Returns the type of this Asn object, such as ASN_INTEGER or
     * IPADDRESS. 
     *
     * Note, the name of this method is deceiving; It has
     * nothing (more) to do with a response.
     *
     * @return The AsnObject type.
     * @see #getRespTypeString()
     * @see SnmpConstants
     */
    public byte getRespType()
    {
        return type;
    }

    /**
     * Returns the object type as string, such as "ASN_INTEGER" or
     * "IPADDRESS".
     *
     * Note, the name of this method is deceiving; It has
     * nothing (more) to do with a response.
     *
     * @return The AsnObject type.
     * @see #getRespType()
     * @see SnmpConstants
     */
    public String getRespTypeString()
    {
        String str = "";
        switch(type)
        {
            case ASN_BOOLEAN:
                str = "ASN_BOOLEAN";
                break;
            case ASN_INTEGER:
                str = "ASN_INTEGER";
                break;
            case ASN_BIT_STR:
                str = "ASN_BIT_STR";
                break;
            case ASN_OCTET_STR:
                str = "ASN_OCTET_STR";
                break;
            case ASN_NULL:
                str = "ASN_NULL";
                break;
            case ASN_OBJECT_ID:
                str = "ASN_OBJECT_ID";
                break;
            case ASN_SEQUENCE:
                str = "ASN_SEQUENCE";
                break;
            case ASN_SET:
                str = "ASN_SET";
                break;
            case ASN_UNIVERSAL:
                str = "ASN_UNIVERSAL";
                break;
            case ASN_PRIVATE:
                str = "ASN_PRIVATE";
                break;
            case ASN_CONSTRUCTOR:
                str = "ASN_CONSTRUCTOR";
                break;
            case ASN_EXTENSION_ID:
                str = "ASN_EXTENSION_ID";
                break;
            case IPADDRESS:
                str = "IPADDRESS";
                break;
            case COUNTER:
                str = "COUNTER";
                break;
            case GAUGE:
                str = "GAUGE";
                break;
            case TIMETICKS:
                str = "TIMETICKS";
                break;
            case OPAQUE:
                str = "OPAQUE";
                break;
            case NSAP_ADDRESS:
                str = "NSAP_ADDRESS";
                break;
            case COUNTER64:
                str = "COUNTER64";
                break;
            case OBSOLETED_RFC1442_UINTEGER32:
                str = "OBSOLETED_RFC1442_UINTEGER32 (SMI v1)";
                break;
            case CONS_SEQ:
                str = "CONS_SEQ";
                break;
            case SNMP_VAR_NOSUCHOBJECT:
                str = "SNMP_VAR_NOSUCHOBJECT";
                break;
            case SNMP_VAR_NOSUCHINSTANCE:
                str = "SNMP_VAR_NOSUCHINSTANCE";
                break;
            case SNMP_VAR_ENDOFMIBVIEW:
                str = "SNMP_VAR_ENDOFMIBVIEW";
                break;
            case GET_REQ_MSG:
                str = "GET_REQ_MSG";
                break;
            case GETNEXT_REQ_MSG:
                str = "GETNEXT_REQ_MSG";
                break;
            case SET_REQ_MSG:
                str = "SET_REQ_MSG";
                break;
            case GETBULK_REQ_MSG:
                str = "GETBULK_REQ_MSG";
                break;
            case INFORM_REQ_MSG:
                str = "INFORM_REQ_MSG";
                break;
            case GET_RSP_MSG:
                str = "GET_RSP_MSG";
                break;
            case GET_RPRT_MSG:
                str = "GET_RPRT_MSG";
                break;
            case TRP_REQ_MSG :
                str = "TRP_REQ_MSG";
                break;
            case TRPV2_REQ_MSG:
                str = "TRPV2_REQ_MSG";
                break;
            default:
                str = "0x" + SnmpUtilities.toHex(type);
        }
        return str;
    }
}