tftp 服务器

人气：3070 2007-11-17

几个月前写的,今天改了一下,只有服务器端.
参考:tftp协议规范
tftp uml

tftpserver.java

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/*
* 创建日期 2004-8-30-11:31:14
*
*/
package starfire.tftp;

import java.net.*;
import java.io.*;
import java.util.*;

/**
* <a href="http://www.longen.org/s-z/details-z/tftpprotocol.htm">tftp 协议规范 </a>
*
* @author <a href="mailto:starfire@bit.edu.cn">starfire </a>
*
*/
public class tftpserver extends thread {

    public static final int default_port = 69;

    private hashmap map = new hashmap();

    private file root;

    private int port = default_port;

    private datagramsocket ds;

    private timer timer = new timer(true);

    public tftpserver() {
        this(".");
    }

    public tftpserver(string rootpath, int port) {
        this(rootpath);
        this.port = port;
    }

    public tftpserver(string rootpath) {
        this.root = new file(rootpath);
        try {
            this.root = this.root.getcanonicalfile();
        } catch (ioexception e) {
            e.printstacktrace();
        }
    }

    public void run() {
        try {
            ds = new datagramsocket(new inetsocketaddress(port));
        } catch (socketexception e) {
            system.out.println("error when create datagram socket:"
                    + e.getmessage());
            return;
        }
        system.out.println("root path:" + root.getpath());
        byte[] buf = new byte[516];
        datagrampacket packet = new datagrampacket(buf, 516);
        while (true) {
            try {
                ds.receive(packet);
                system.out.println("recv packet:");
                tftppacketutil.displaybytes(packet.getdata());//
                process(packet);
            } catch (ioexception e1) {
                e1.printstacktrace();
            }
        }
    }

    protected void process(datagrampacket packet) {
        try {
            byte[] buf = new byte[packet.getlength()];
            system.arraycopy(packet.getdata(), 0, buf, 0, buf.length);
            tftppacket tfp = tftppacketutil.decode(buf);
            inetsocketaddress address = new inetsocketaddress(packet
                    .getaddress(), packet.getport());
            string key = address.gethostname() + ":" + address.getport();
            system.out.println("key=" + key);
            system.out.println("packet:" + tfp);
            if (tfp.getoperatecode() == tftppacket.rrq
                    || tfp.getoperatecode() == tftppacket.wrq) {
                client client = new client(address);
                boolean result = client.doaccept((rwpacket) tfp);
                if (result) {
                    map.put(key, client);
                }
            } else if (tfp.getoperatecode() == tftppacket.data) {
                client client = (client) map.get(key);
                if (client == null) {
                    return;
                }
                boolean result = client.doprocess((datapacket) tfp);
                if (result) {
                    map.remove(key);
                    client.destroy();
                }
            } else if (tfp.getoperatecode() == tftppacket.ack) {
                client client = (client) map.get(key);
                if (client == null) {
                    return;
                }
                boolean result = client.doprocess((ackpacket) tfp);
                if (result) {
                    map.remove(key);
                    client.destroy();
                }
            } else if (tfp.getoperatecode() == tftppacket.error) {
                system.out.println(tfp);
                client client = (client) map.remove(key);
                client.destroy();
            }
        } catch (badpacketformatexception e) {
            e.printstacktrace();
            system.out.println("recv unknown packet.");
        }
    }

    protected void send(inetsocketaddress address, byte[] data) {
        datagrampacket packet = new datagrampacket(data, data.length, address
                .getaddress(), address.getport());
        try {
            ds.send(packet);
            system.out.println("send packet:");
            tftppacketutil.displaybytes(data);
        } catch (ioexception e) {
            e.printstacktrace();
        }
    }

    class client {
        public static final int default_data_size = 512;

        public static final int default_time_out = 1000;

        private inetsocketaddress address;

        private string filename;

        private int block;

        private boolean checked;//上次发送的包已收到回应

        private randomaccessfile raf;

        private boolean accepted = false;

        private byte[] buf = new byte[default_data_size];

        private byte[] data;

        private int times = 0;//每几次重发

        private resendtask task;

        public client(inetsocketaddress address) {
            this.address = address;
        }

        public void destroy() {
            if (task != null) {
                task.cancel();
            }
            if (raf != null) {
                try {
                    raf.close();
                } catch (ioexception e) {
                    e.printstacktrace();
                }
                raf = null;
            }
        }

        /**
         * if accept,return true;else return false.
         *
         * @param packet
         * @return
         */
        public boolean doaccept(rwpacket packet) {
            this.filename = packet.getfilename();
            if (accepted) {
                return true;
            }
            if (packet.getoperatecode() == tftppacket.rrq) {
                try {
                    file file = new file(root, filename);
                    system.out.println(file.getpath() + " " + file.exists());
                    raf = new randomaccessfile(file, "r");
                    data = new byte[default_data_size];
                    int size = raf.read(data);
                    datapacket dp = new datapacket();
                    dp.setblock(1);
                    if (size != default_data_size) {
                        byte[] buf = new byte[size];
                        system.arraycopy(data, 0, buf, 0, size);
                        data = buf;
                    }
                    dp.setdata(data);
                    data = tftppacketutil.encode(dp);
                    send(address, data);
                    block = 1;
                    task = new resendtask(address, data);
                    timer.schedule(task, default_time_out);
                } catch (filenotfoundexception e) {
                    system.out
                            .println("file:" + e.getmessage() + " not found.");
                    errorpacket ep = new errorpacket();
                    ep.seterrorcode(errorpacket.file_not_found_code);
                    byte[] data = tftppacketutil.encode(ep);
                    send(address, data);
                    return false;
                } catch (ioexception e) {
                    e.printstacktrace();
                }
            } else {
                file file = new file(root, filename);
                if (file.exists()) {
                    errorpacket ep = new errorpacket();
                    ep.seterrorcode(errorpacket.file_exist_code);
                    ep.seterrormessage("file:" + filename + " has exist");
                    byte[] data = tftppacketutil.encode(ep);
                    send(address, data);
                    return false;
                }
                try {
                    file.createnewfile();
                    raf = new randomaccessfile(file, "rwd");
                } catch (ioexception e) {
                    system.out.println("create file:" + filename + " failed.");
                    errorpacket ep = new errorpacket();
                    ep.seterrorcode(errorpacket.not_defined_code);
                    byte[] data = tftppacketutil.encode(ep);
                    send(address, data);
                    return false;
                }
                ackpacket ap = new ackpacket();
                ap.setblock(0);
                data = tftppacketutil.encode(ap);
                send(address, data);
                task = new resendtask(address, data);
                timer.schedule(task, default_time_out);
            }
            accepted = true;
            return accepted;
        }

        /**
         * if transfer end,return true,else return false.
         *
         * @param packet
         * @return
         */
        public boolean doprocess(ackpacket packet) {
            if (task != null) {
                task.cancel();
                task = null;
            }
            if (packet.getblock() == block) {
                try {
                    if (raf == null
                            || raf.length() <= block * default_data_size) {
                        return true;
                    }
                    raf.seek(block * default_data_size);
                    int size = raf.read(buf);
                    data = buf;
                    if (size < default_data_size) {
                        data = new byte[size];
                        system.arraycopy(buf, 0, data, 0, size);
                        raf.close();
                        raf = null;
                    }
                    datapacket dp = new datapacket();
                    block++;
                    dp.setblock(block);
                    dp.setdata(data);
                    data = tftppacketutil.encode(dp);
                    send(address, data);
                    tftppacketutil.displaybytes(data);
                    task = new resendtask(address, data);
                    timer.schedule(task, default_time_out);
                } catch (ioexception e) {
                    e.printstacktrace();
                }
            }
            return false;
        }

        /**
         * if transfer end,return true,else return false.
         *
         * @param packet
         * @return
         */
        public boolean doprocess(datapacket packet) {
            if (task != null) {
                task.cancel();
                task = null;
            }
            byte[] data = packet.getdata();
            if (packet.getblock() != block + 1) {
                return false;
            }
            block++;
            ackpacket ap = new ackpacket();
            ap.setblock(block);
            if (data != null) {
                try {
                    raf.write(data);
                } catch (ioexception e) {
                    e.printstacktrace();
                }
            }
            if (data == null || data.length < default_data_size) {
                try {
                    raf.close();
                    raf = null;
                } catch (ioexception e) {
                    e.printstacktrace();
                }
            }
            data = tftppacketutil.encode(ap);
            send(address, data);
            task = new resendtask(address, data);
            timer.schedule(task, default_time_out);
            return packet.getdata() == null
                    || packet.getdata().length < default_data_size;
        }

    }

    class resendtask extends java.util.timertask {
        private inetsocketaddress address;

        private byte[] data;

        private int times = 1;

        public resendtask(inetsocketaddress address, byte[] data) {
            this.address = address;
            this.data = data;
        }

        public resendtask(inetsocketaddress address, byte[] data,int times) {
            this.address = address;
            this.data = data;
            this.times = times;
        }

        public void run() {
            send(address, data);
            if (times < 3) {//最多发3次
                timer.schedule(new resendtask(address,data,times+1), (int) (math.pow(2, times+1))
                        * client.default_time_out);
            }
        }

        public byte[] getdata() {
            return data;
        }
    }

    public static void main(string[] args) {
        new tftpserver("e://").start();
    }

    /**
     * @return
     */
    public file getroot() {
        return root;
    }

    /**
     * @return
     */
    public int getport() {
        return port;
    }

    /**
     * @param i
     */
    public void setport(int i) {
        port = i;
    }

}

tftppacketutil.java

/*
* 创建日期 2004-8-30-12:49:20
*
*/
package starfire.tftp;

/**
* @author <a href="mailto:starfire@bit.edu.cn">starfire</a>
*
*/
public final class tftppacketutil {

  private tftppacketutil() {

  }

  public static tftppacket decode(byte[] buf) throws badpacketformatexception {
    if (buf==null || buf.length<4) {
      throw new badpacketformatexception("packet too small");
    }
    int operatecode = buf[1];
    if (operatecode<tftppacket.rrq || operatecode>tftppacket.error) {
      throw new badpacketformatexception("unknown operate code");
    }
    switch (operatecode) {
      case tftppacket.rrq:
      case tftppacket.wrq:
        return decoderwpacket(buf);
      case tftppacket.data:
        return decodedatapacket(buf);
      case tftppacket.ack:
        return decodeackpacket(buf);
      case tftppacket.error:
        return decodeerrorpacket(buf);
    }
    return null;
  }

  /**
   * 2 bytes       2 bytes string 1 byte
   * -----------------------------------------
   * | opcode | errorcode | errmsg | 0 |
   * -----------------------------------------
   */
  private static tftppacket decodeerrorpacket(byte[] buf) throws badpacketformatexception {
    if (buf.length<4) {
      throw new badpacketformatexception("ack packet must >= 4 bytes");
    }
    errorpacket packet = new errorpacket();
    packet.setoperatecode(tftppacket.error);
    packet.seterrorcode(buf[2]<<8+buf[3]);
    int end = 4;
    int i = 4;
    for (;i<buf.length;i++) {
      if (buf[i]==0) {
        end = i;
        break;
      }
    }
    if (i!=buf.length) {
      string str = new string(buf,4,end-4);
      packet.seterrormessage(str);
    }
    return packet;
  }

  /**
   * 2 bytes 2 bytes
   * ---------------------
   * | opcode | block # |
   * ---------------------
   * @param buf
   * @return
   */
  private static tftppacket decodeackpacket(byte[] buf) throws badpacketformatexception {
    displaybytes(buf);
    if (buf.length<4) {
      throw new badpacketformatexception("ack packet must be 4 bytes");
    }
    ackpacket packet = new ackpacket();
    packet.setoperatecode(tftppacket.ack);
    //system.out.println("buf[2]="+buf[2]+" buf[3]="+buf[3]+" total="+(buf[2]*256+buf[3]));
    packet.setblock(byte2int(buf[2])*256+byte2int(buf[3]));
    //system.out.println("block:"+packet.getblock());
    return packet;
  }

  /**
   * 2 bytes   2 bytes   n bytes
   * ----------------------------------
   * | opcode | block # | data |
   * ----------------------------------
   * @param buf
   * @return
   */
  private static tftppacket decodedatapacket(byte[] buf) throws badpacketformatexception  {
    if (buf.length<4) {
      throw new badpacketformatexception("bad data packet");
    }
    datapacket packet = new datapacket();
    packet.setoperatecode(tftppacket.data);
    packet.setblock(byte2int(buf[2])*256+byte2int(buf[3]));
    //system.out.println("decode data packet,block:"+packet.getblock());
    byte[] data = new byte[buf.length-4];
    system.arraycopy(buf,4,data,0,data.length);
    packet.setdata(data);
    return packet;
  }

  private static int byte2int(byte b) {
    if ((b&0x80)!=0) {
      return 128+(b&0x7f);
    }
    else {
      return b;
    }
  }

  /**
   * rrq,wrq packet format
   *  2 bytes    string   1 byte string 1 byte
   *  ------------------------------------------------
   *  | opcode | filename | 0 | mode | 0 |
   *  ------------------------------------------------
   * @param buf
   * @return
   */
  private static tftppacket decoderwpacket(byte[] buf) throws badpacketformatexception {
    rwpacket packet = new rwpacket();
    packet.setoperatecode((int)buf[1]);
    int start = 2;
    int end = 2;
    int i;
    for (i=start;i<buf.length;i++) {
      if (buf[i]==0) {
        end = i;
        break;
      }
    }
    if (i==buf.length) {
      throw new badpacketformatexception();
    }
    packet.setfilename(new string(buf,start,end-start));
    start = end+1;
    end = start;
    for (i=start;i<buf.length;i++) {
      if (buf[i]==0) {
        end = i;
        break;
      }
    }
    if (i==buf.length) {
      throw new badpacketformatexception();
    }
    packet.setmode(new string(buf,start,end-start));
    return packet;
  }

  public static byte[] encode(tftppacket packet) {
    int operatecode = packet.getoperatecode();
    switch (operatecode) {
      case tftppacket.rrq:
      case tftppacket.wrq:
        return encoderwpacket((rwpacket)packet);
      case tftppacket.data:
        return encodedatapacket((datapacket)packet);
      case tftppacket.ack:
        return encodeackpacket((ackpacket)packet);
      case tftppacket.error:
        return encodeerrorpacket((errorpacket)packet);

    }
    return null;
  }

  /**
   * @param packet
   * @return
   */
  private static byte[] encodeerrorpacket(errorpacket packet) {
    byte[] messagebytes = null;
    if (packet.geterrormessage()!=null) {
      messagebytes = packet.geterrormessage().getbytes();
    }
    int size = messagebytes==null?0:messagebytes.length;
    size += 2+2+1;
    byte[] buf = new byte[size];
    buf[1] = (byte)(tftppacket.error&0xff);
    int errorcode = packet.geterrorcode();
    buf[2] = (byte)((errorcode>>8)&0xff);
    buf[3] = (byte)(errorcode&0xff);
    if (messagebytes!=null) {
      system.arraycopy(messagebytes,0,buf,4,messagebytes.length);
    }
    return buf;
  }

  /**
   * @param packet
   * @return
   */
  private static byte[] encodeackpacket(ackpacket packet) {
    byte[] buf = new byte[4];
    buf[1] = (byte)(tftppacket.ack&0xff);
    int block = packet.getblock();
    buf[2] = (byte)((block>>8)&0xff);
    buf[3] = (byte)(block&0xff);
    return buf;
  }

  /**
   * @param packet
   * @return
   */
  private static