Subversion Repositories fpga-cf

/**

 *

 */

package edu.byu.cc.plieber.fpgaenet.fcp;

import java.net.DatagramPacket;

import java.net.InetAddress;

/**

 * @author plieber

 *

 */

public class FCPPacket {

        public InetAddress source;

        public InetAddress dest;

        public int srcPort;

        public int dstPort;

        public int version;

        public int command;

        public int port;

        public int seq;

        public int len;

        public byte[] data;

        /**

         * Constructs an FCP packet from the data of a UDP datagram packet.

         * @param packet The UDP datagram packet containing exactly one FCP packet.

         */

        public FCPPacket(DatagramPacket packet) {

                source = packet.getAddress();

                srcPort = packet.getPort();

                version = (packet.getData()[0] & 0xf0) >> 4;

                command = packet.getData()[0] & 0x0f;

                port = packet.getData()[1] & 0xff;

                seq = ((packet.getData()[2] << 8) & 0xff00) + (packet.getData()[3] & 0xff);

                len = ((packet.getData()[4] << 8) & 0xff00) + (packet.getData()[5] & 0xff);

                data = new byte[len];

                for (int i = 0; i < len; i++) {

                        data[i] = packet.getData()[6 + i];

                }

        }

        public FCPPacket() {

                // TODO Auto-generated constructor stub

        }

        @Override

        public String toString() {

                String ret = "FCP IcapPacket { version=" + version + ", command=" + command

                                + ", port=" + port + ", seq=" + seq + ", len=" + len;

                if (this.len > 0 && data != null) {

                        ret += " <data: ";

                        for (int i=0; i<(len-1); i++) {

                                ret += String.format("%H", data[i] & 0xff) + ",";

                        }

                        ret += String.format("%H", data[len-1] & 0xff) + ">";

                }

                return ret + " }";

        }

        /**

         * Wraps this FCP packet into a datagram packet for sending over a UDP socket.

         * @param dest Destination internet address

         * @param port remote port number

         * @return

         */

        public DatagramPacket wrapInDatagram(InetAddress dest, int port) {

                byte[] buf = new byte[6 + (this.command != 4 ? len: 0)];

                buf[0] = (byte) (((version << 4) & 0xf0) | (command & 0x0f));

                buf[1] = (byte) this.port;

                buf[2] = (byte) ((seq >> 8) & 0xff);

                buf[3] = (byte) (seq & 0xff);

                buf[4] = (byte) ((len >> 8) & 0xff);

                buf[5] = (byte) (len & 0xff);

                if (this.command != 4) {

                        for (int i = 0; i < len; i++) {

                                buf[6 + i] = data[i];

                        }

                }

                DatagramPacket packet = new DatagramPacket(buf, buf.length);

                packet.setPort(port);

                packet.setAddress(dest);

                return packet;

        }

        /**

         * Wraps this FCP packet into a datagram packet for sending over a UDP socket.

         * @return

         */

        public DatagramPacket wrapInDatagram() {

                byte[] buf = new byte[6 + (this.command != 4 ? len: 0)];

                buf[0] = (byte) (((version << 4) & 0xf0) | (command & 0x0f));

                buf[1] = (byte) this.port;

                buf[2] = (byte) ((seq >> 8) & 0xff);

                buf[3] = (byte) (seq & 0xff);

                buf[4] = (byte) ((len >> 8) & 0xff);

                buf[5] = (byte) (len & 0xff);

                if (this.command != 4) {

                        for (int i = 0; i < len; i++) {

                                buf[6 + i] = data[i];

                        }

                }

                DatagramPacket packet = new DatagramPacket(buf, buf.length);

                packet.setPort(this.dstPort);

                packet.setAddress(this.dest);

                return packet;

        }

}