dhcpoption.java

DHCP 的JAVA实现

	 * DHO_SUBNET_MASK(1)
	 * DHO_SWAP_SERVER(16)
	 * DHO_BROADCAST_ADDRESS(28)
	 * DHO_ROUTER_SOLICITATION_ADDRESS(32)
	 * DHO_DHCP_REQUESTED_ADDRESS(50)
	 * DHO_DHCP_SERVER_IDENTIFIER(54)
	 * DHO_SUBNET_SELECTION(118)
     * </pre>
     * 
     * @return the option value, <tt>null</tt> if option is not present.
     * @throws IllegalArgumentException the option code is not in the list above.
     * @throws DHCPBadPacketException the option value in packet is of wrong size.
     */
    public InetAddress getValueAsInetAddr() throws IllegalArgumentException {
    	if (!isOptionAsInetAddr(code)) {
            throw new IllegalArgumentException("DHCP option type ("+ this.code +") is not InetAddr");
        }
        if (this.value == null) {
            throw new IllegalStateException("value is null");
        }
        if (this.value.length != 4) {
            throw new DHCPBadPacketException("option " + this.code + " is wrong size:" + this.value.length + " should be 4");
        }
        try {
            return InetAddress.getByAddress(this.value);
        } catch (UnknownHostException e) {
			logger.log(Level.SEVERE, "Unexpected UnknownHostException", e);
            return null;	// normally impossible
        }
    }

    public static final boolean isOptionAsString(byte code) {
    	return OptionFormat.STRING.equals(_DHO_FORMATS.get(code));
    }
    /**
     * Returns a DHCP Option as String format.
     * 
     * <p>This method is only allowed for the following option codes:
     * <pre>
	 * DHO_HOST_NAME(12)
	 * DHO_MERIT_DUMP(14)
	 * DHO_DOMAIN_NAME(15)
	 * DHO_ROOT_PATH(17)
	 * DHO_EXTENSIONS_PATH(18)
	 * DHO_NETBIOS_SCOPE(47)
	 * DHO_DHCP_MESSAGE(56)
	 * DHO_VENDOR_CLASS_IDENTIFIER(60)
	 * DHO_NWIP_DOMAIN_NAME(62)
	 * DHO_NIS_DOMAIN(64)
	 * DHO_NIS_SERVER(65)
	 * DHO_TFTP_SERVER(66)
	 * DHO_BOOTFILE(67)
	 * DHO_NDS_TREE_NAME(86)
	 * DHO_USER_AUTHENTICATION_PROTOCOL(98)
     * </pre>
     * 
     * @return the option value, <tt>null</tt> if option is not present.
     * @throws IllegalArgumentException the option code is not in the list above.
     */
    public String getValueAsString() throws IllegalArgumentException {
    	if (!isOptionAsString(code)) {
            throw new IllegalArgumentException("DHCP option type ("+ this.code +") is not String");
        }
        if (this.value == null) {
            throw new IllegalStateException("value is null");
        }
        return DHCPPacket.bytesToString(this.value);
    }

    public static final boolean isOptionAsShorts(byte code) {
    	return OptionFormat.SHORTS.equals(_DHO_FORMATS.get(code));
    }
    /**
     * Returns a DHCP Option as Short array format.
     * 
     * <p>This method is only allowed for the following option codes:
     * <pre>
	 * DHO_PATH_MTU_PLATEAU_TABLE(25)
	 * DHO_NAME_SERVICE_SEARCH(117)
     * </pre>
     * 
     * @return the option value array, <tt>null</tt> if option is not present.
     * @throws IllegalArgumentException the option code is not in the list above.
     * @throws DHCPBadPacketException the option value in packet is of wrong size.
     */
    public short[] getValueAsShorts() throws IllegalArgumentException {
    	if (!isOptionAsShorts(code)) {
            throw new IllegalArgumentException("DHCP option type ("+ this.code +") is not short[]");
        }
        if (this.value == null) {
            throw new IllegalStateException("value is null");
        }
        if ((this.value.length % 2) != 0)		// multiple of 2
        {
            throw new DHCPBadPacketException("option " + this.code + " is wrong size:" + this.value.length + " should be 2*X");
        }
        
        short[] shorts = new short[this.value.length / 2];
        for (int i=0, a=0; a< this.value.length; i++, a+=2) {
            shorts[i] = (short) (((this.value[a] & 0xFF)<<8) | (this.value[a+1] & 0xFF));
        }
        return shorts;
    }

    public static final boolean isOptionAsInetAddrs(byte code) {
    	return OptionFormat.INETS.equals(_DHO_FORMATS.get(code));
    }
    /**
     * Returns a DHCP Option as InetAddress array format.
     * 
     * <p>This method is only allowed for the following option codes:
     * <pre>
	 * DHO_ROUTERS(3)
	 * DHO_TIME_SERVERS(4)
	 * DHO_NAME_SERVERS(5)
	 * DHO_DOMAIN_NAME_SERVERS(6)
	 * DHO_LOG_SERVERS(7)
	 * DHO_COOKIE_SERVERS(8)
	 * DHO_LPR_SERVERS(9)
	 * DHO_IMPRESS_SERVERS(10)
	 * DHO_RESOURCE_LOCATION_SERVERS(11)
	 * DHO_POLICY_FILTER(21)
	 * DHO_STATIC_ROUTES(33)
	 * DHO_NIS_SERVERS(41)
	 * DHO_NTP_SERVERS(42)
	 * DHO_NETBIOS_NAME_SERVERS(44)
	 * DHO_NETBIOS_DD_SERVER(45)
	 * DHO_FONT_SERVERS(48)
	 * DHO_X_DISPLAY_MANAGER(49)
	 * DHO_MOBILE_IP_HOME_AGENT(68)
	 * DHO_SMTP_SERVER(69)
	 * DHO_POP3_SERVER(70)
	 * DHO_NNTP_SERVER(71)
	 * DHO_WWW_SERVER(72)
	 * DHO_FINGER_SERVER(73)
	 * DHO_IRC_SERVER(74)
	 * DHO_STREETTALK_SERVER(75)
	 * DHO_STDA_SERVER(76)
	 * DHO_NDS_SERVERS(85)
     * </pre>
     * 
     * @return the option value array, <tt>null</tt> if option is not present.
     * @throws IllegalArgumentException the option code is not in the list above.
     * @throws DHCPBadPacketException the option value in packet is of wrong size.
     */
    public InetAddress[] getValueAsInetAddrs() throws IllegalArgumentException {
    	if (!isOptionAsInetAddrs(code)) {
            throw new IllegalArgumentException("DHCP option type ("+ this.code +") is not InetAddr[]");
        }
        if (this.value == null) {
            throw new IllegalStateException("value is null");
        }
        if ((this.value.length % 4) != 0)		// multiple of 4
        {
            throw new DHCPBadPacketException("option " + this.code + " is wrong size:" + this.value.length + " should be 4*X");
        }
        try {
            byte[] addr = new byte[4];
            InetAddress[] addrs = new InetAddress[this.value.length / 4];
            for (int i=0, a=0; a< this.value.length; i++, a+=4) {
                addr[0] = this.value[a];
                addr[1] = this.value[a+1];
                addr[2] = this.value[a+2];
                addr[3] = this.value[a+3];
                addrs[i] = InetAddress.getByAddress(addr); 
            }
            return addrs;
        } catch (UnknownHostException e) {
			logger.log(Level.SEVERE, "Unexpected UnknownHostException", e);
            return null;	// normally impossible
        }
    }

    public static final boolean isOptionAsBytes(byte code) {
    	return OptionFormat.BYTES.equals(_DHO_FORMATS.get(code));
    }
    /**
     * Returns a DHCP Option as Byte array format.
     * 
     * <p>This method is only allowed for the following option codes:
     * <pre>
     * DHO_DHCP_PARAMETER_REQUEST_LIST(55)
     * </pre>
     * 
     * <p>Note: this mehtod is similar to getOptionRaw, only with option type checking.
     * 
     * @return the option value array, <tt>null</tt> if option is not present.
     * @throws IllegalArgumentException the option code is not in the list above.
     */
    public byte[] getValueAsBytes() throws IllegalArgumentException {
    	if (!isOptionAsBytes(code)) {
            throw new IllegalArgumentException("DHCP option type ("+ this.code +") is not bytes");
        }
        if (this.value == null) {
            throw new IllegalStateException("value is null");
        }
        return this.getValue();
    }

    /**
     * Creates a DHCP Option as Short format.
     * 
     * <p>This method is only allowed for the following option codes:
     * <pre>
	 * DHO_BOOT_SIZE(13)
	 * DHO_MAX_DGRAM_REASSEMBLY(22)
	 * DHO_INTERFACE_MTU(26)
	 * DHO_DHCP_MAX_MESSAGE_SIZE(57)
     * </pre>
     * 
     * @param code the option code.
     * @param val the value
     * @throws IllegalArgumentException the option code is not in the list above.
     */
    public static DHCPOption newOptionAsShort(byte code, short val) {
    	if (!isOptionAsShort(code)) {
            throw new IllegalArgumentException("DHCP option type ("+code+") is not short");
        }
        return new DHCPOption(code, short2Bytes(val));
    }
    
    /**
     * Creates a DHCP Options as Short[] format.
     * 
     * <p>This method is only allowed for the following option codes:
     * <pre>
	 * DHO_PATH_MTU_PLATEAU_TABLE(25)
	 * DHO_NAME_SERVICE_SEARCH(117)
     * </pre>
     * 
     * @param code the option code.
     * @param arr the array of shorts
     * @throws IllegalArgumentException the option code is not in the list above.
     */
    public static DHCPOption newOptionAsShorts(byte code, short[] arr) {
    	if (!isOptionAsShorts(code)) {
            throw new IllegalArgumentException("DHCP option type ("+code+") is not shorts");
    	}
    	byte[] buf = null;
    	if (arr != null) {
    		buf = new byte[arr.length * 2];
    		for (int i=0; i<arr.length; i++) {
    			short val = arr[i];
    			buf[i*2] = (byte) ((val & 0xFF00) >>> 8);
            	buf[i*2+1] = (byte) (val & 0XFF);
    		}
    	}
    	return new DHCPOption(code, buf);
    }
    
    /**
     * Creates a DHCP Option as Integer format.
     * 
     * <p>This method is only allowed for the following option codes:
     * <pre>
	 * DHO_TIME_OFFSET(2)
	 * DHO_PATH_MTU_AGING_TIMEOUT(24)
	 * DHO_ARP_CACHE_TIMEOUT(35)
	 * DHO_TCP_KEEPALIVE_INTERVAL(38)
	 * DHO_DHCP_LEASE_TIME(51)
	 * DHO_DHCP_RENEWAL_TIME(58)
	 * DHO_DHCP_REBINDING_TIME(59)
     * </pre>
     * 
     * @param code the option code.
     * @param val the value
     * @throws IllegalArgumentException the option code is not in the list above.
     */
    public static DHCPOption newOptionAsInt(byte code, int val) {
    	if (!isOptionAsInt(code)) {
            throw new IllegalArgumentException("DHCP option type ("+code+") is not int");
        }
        return new DHCPOption(code, int2Bytes(val));
    }

    /**
     * Sets a DHCP Option as InetAddress format.
     * 
     * <p>This method is only allowed for the following option codes:
     * <pre>
	 * DHO_SUBNET_MASK(1)
	 * DHO_SWAP_SERVER(16)
	 * DHO_BROADCAST_ADDRESS(28)
	 * DHO_ROUTER_SOLICITATION_ADDRESS(32)
	 * DHO_DHCP_REQUESTED_ADDRESS(50)
	 * DHO_DHCP_SERVER_IDENTIFIER(54)
	 * DHO_SUBNET_SELECTION(118)
     * </pre>
     * and also as a simplified version for setOptionAsInetAddresses
     * <pre>
	 * DHO_ROUTERS(3)
	 * DHO_TIME_SERVERS(4)
	 * DHO_NAME_SERVERS(5)
	 * DHO_DOMAIN_NAME_SERVERS(6)
	 * DHO_LOG_SERVERS(7)
	 * DHO_COOKIE_SERVERS(8)
	 * DHO_LPR_SERVERS(9)
	 * DHO_IMPRESS_SERVERS(10)
	 * DHO_RESOURCE_LOCATION_SERVERS(11)
	 * DHO_POLICY_FILTER(21)
	 * DHO_STATIC_ROUTES(33)
	 * DHO_NIS_SERVERS(41)
	 * DHO_NTP_SERVERS(42)
	 * DHO_NETBIOS_NAME_SERVERS(44)
	 * DHO_NETBIOS_DD_SERVER(45)
	 * DHO_FONT_SERVERS(48)
	 * DHO_X_DISPLAY_MANAGER(49)
	 * DHO_MOBILE_IP_HOME_AGENT(68)
	 * DHO_SMTP_SERVER(69)
	 * DHO_POP3_SERVER(70)
	 * DHO_NNTP_SERVER(71)
	 * DHO_WWW_SERVER(72)
	 * DHO_FINGER_SERVER(73)
	 * DHO_IRC_SERVER(74)
	 * DHO_STREETTALK_SERVER(75)
	 * DHO_STDA_SERVER(76)
	 * DHO_NDS_SERVERS(85)
     * </pre>
     * 
     * @param code the option code.
     * @param val the value
     * @throws IllegalArgumentException the option code is not in the list above.
     */
    public static DHCPOption newOptionAsInetAddress(byte code, InetAddress val) {
    	if ((!isOptionAsInetAddr(code)) &&
    		(!isOptionAsInetAddrs(code))) {
            throw new IllegalArgumentException("DHCP option type ("+code+") is not InetAddress");
        }
        return new DHCPOption(code, inetAddress2Bytes(val));
    }

    /**
     * Creates a DHCP Option as InetAddress array format.
     * 
     * <p>This method is only allowed for the following option codes:
     * <pre>
	 * DHO_ROUTERS(3)
	 * DHO_TIME_SERVERS(4)
	 * DHO_NAME_SERVERS(5)
	 * DHO_DOMAIN_NAME_SERVERS(6)
	 * DHO_LOG_SERVERS(7)
	 * DHO_COOKIE_SERVERS(8)
	 * DHO_LPR_SERVERS(9)
	 * DHO_IMPRESS_SERVERS(10)
	 * DHO_RESOURCE_LOCATION_SERVERS(11)
	 * DHO_POLICY_FILTER(21)
	 * DHO_STATIC_ROUTES(33)
	 * DHO_NIS_SERVERS(41)
	 * DHO_NTP_SERVERS(42)
	 * DHO_NETBIOS_NAME_SERVERS(44)
	 * DHO_NETBIOS_DD_SERVER(45)
	 * DHO_FONT_SERVERS(48)
	 * DHO_X_DISPLAY_MANAGER(49)
	 * DHO_MOBILE_IP_HOME_AGENT(68)
	 * DHO_SMTP_SERVER(69)
	 * DHO_POP3_SERVER(70)
	 * DHO_NNTP_SERVER(71)
	 * DHO_WWW_SERVER(72)
	 * DHO_FINGER_SERVER(73)
	 * DHO_IRC_SERVER(74)
	 * DHO_STREETTALK_SERVER(75)