Created
April 4, 2018 11:15
-
-
Save aurorapar/b514ca82c38b20f7a22d6d1f5187828b to your computer and use it in GitHub Desktop.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// Client | |
import java.net.*; | |
import java.io.*; | |
import java.util.*; | |
import java.nio.charset.*; | |
public class Client | |
{ | |
public static int serverPort = 69; | |
public static int blockNumber = 0; | |
public static String serverAddress; | |
public static int timeouts = 0; | |
public static int missedPackets = 0; | |
public static final int TIMEOUTS_MAX = 6; | |
public static final int MISSED_PACKET_MAX = 6; | |
public static final int BUFFER_SIZE = 516; | |
public static final int TIMEOUT_INTERVAL = 2000; | |
public static void main(String args[]) | |
{ | |
if(args.length != 3) | |
{ | |
System.out.println("Improper argument length. Correct options are:\n\t[PUT|GET] file"); | |
return; | |
} | |
serverAddress = args[0]; | |
String operation = args[1].toUpperCase(); | |
String fileName = args[2]; | |
if(!"PUT".equals(operation) && !"GET".equals(operation)) | |
{ | |
System.out.println(String.format("Could not handle \'operation\' %s\nAccepted operations are:\n\tPUT\tGET\n",operation)); | |
return; | |
} | |
File f = new File(fileName); | |
if(!f.exists() || f.isDirectory()) | |
{ | |
System.out.println(String.format("Could not handle request\n\t%s\ndoes not exist", fileName)); | |
return; | |
} | |
byte[] fileData; | |
FileInputStream fileStream; | |
int fileSize; | |
try | |
{ | |
fileStream = new FileInputStream(f); | |
fileSize = fileStream.available(); | |
System.out.println(String.format("Bytes to be sent:\n\t%dkb", fileSize/1000)); | |
} | |
catch(Exception e) | |
{ | |
debug(e.toString()); | |
return; | |
} | |
byte OPCode; | |
if("GET".equals(operation)) | |
OPCode = 0x1; | |
else | |
{ | |
OPCode = 0x2; | |
} | |
// Communications | |
byte[] receiveData = new byte[Client.BUFFER_SIZE]; | |
try | |
{ | |
ByteArrayOutputStream sendStream = new ByteArrayOutputStream(Client.BUFFER_SIZE); | |
ByteArrayOutputStream receiveStream = new ByteArrayOutputStream(Client.BUFFER_SIZE); | |
sendStream.write(0x0); | |
sendStream.write(OPCode); | |
sendStream.write(fileName.getBytes("US-ASCII")); | |
sendStream.write(0x0); | |
sendStream.write("netascii".getBytes("US-ASCII")); | |
sendStream.write(0x0); | |
DatagramSocket client = new DatagramSocket(); | |
client.setSoTimeout(Client.TIMEOUT_INTERVAL); | |
send(sendStream.toByteArray(), client, Client.serverPort); | |
DatagramPacket receivedPacket = new DatagramPacket(receiveData, receiveData.length); | |
client.receive(receivedPacket); | |
int replyPort = receivedPacket.getPort(); | |
String reply = new String(receivedPacket.getData(), StandardCharsets.US_ASCII).substring(0,receivedPacket.getLength()); | |
receiveStream.reset(); | |
receiveStream.write(reply.getBytes("US-ASCII")); | |
receiveData = receiveStream.toByteArray(); | |
//debug("'" + new String(receiveData, "US-ASCII") + "'"); | |
if(receiveData[1] == 5) | |
{ | |
System.out.println("Error:\n\t" + new String(Arrays.copyOfRange(receiveData, 4, receiveData.length), StandardCharsets.US_ASCII));return; | |
} | |
if(0x2 == OPCode) | |
{ | |
// State information | |
int block = 1; | |
int sentData = 0; | |
byte[] lastSentPacket = sendStream.toByteArray(); | |
byte[] lastReceivedPacket = receiveStream.toByteArray(); | |
while(fileStream.available() > 0) | |
{ | |
Client.timeouts = 0; | |
missedPackets = 0; | |
sendStream.reset(); | |
sendStream.write(0x0); | |
sendStream.write(0x3); | |
sendStream.write(0x0); | |
sendStream.write(block); | |
while(sendStream.size() < Client.BUFFER_SIZE) | |
{ | |
int b; | |
b = fileStream.read(); | |
if(b == -1) | |
break; | |
sendStream.write((byte) b); | |
} | |
sentData += sendStream.size() - 4; // Don't do buffer size because of last f | |
System.out.print(String.format("\rStatus:\t\t%.2f%%", (double) sentData/fileSize*100)); | |
send(sendStream.toByteArray(), client, replyPort); | |
lastSentPacket = sendStream.toByteArray(); | |
while(true) | |
{ | |
try | |
{ | |
client.receive(receivedPacket); | |
reply = new String(receivedPacket.getData(), StandardCharsets.US_ASCII).substring(0,receivedPacket.getLength()); | |
receiveStream.reset(); | |
receiveStream.write(reply.getBytes("US-ASCII")); | |
receiveData = receiveStream.toByteArray(); | |
lastReceivedPacket = receiveStream.toByteArray(); | |
// TFTP resets at 128 to block 63 ??? | |
//if(block==128 && receiveData[3] == 63) | |
// block = 62; | |
replyPort = receivedPacket.getPort(); | |
break; | |
} | |
catch(SocketTimeoutException e) | |
{ | |
Client.timeouts++; | |
if(Client.timeouts>Client.TIMEOUTS_MAX) | |
{ | |
System.out.println("Maximum number of attempts reached. Ending program."); | |
return; | |
} | |
System.out.println("\nTimed out, retrying...\nNumber of attemps: " + Client.timeouts); | |
send(lastSentPacket, client, replyPort); | |
} | |
} | |
if(receiveData[3] != block) | |
{ | |
if(receiveData[1] == 5) | |
{ | |
System.out.println("Error:\n\t" + new String(Arrays.copyOfRange(receiveData, 4, receiveData.length), StandardCharsets.US_ASCII)); | |
return; | |
} | |
/* | |
if(receiveData[3] == 63) | |
{ | |
block = 63; | |
} | |
*/ | |
if(receiveData[3] == block - 1) | |
{ | |
while(true) | |
{ | |
try | |
{ | |
Client.missedPackets++; | |
if(Client.missedPackets > Client.MISSED_PACKET_MAX) | |
{ | |
System.out.println("Maximum number of missed packets reached. Ending program."); | |
return; | |
} | |
System.out.println("\nMissed packet...\n"+ Client.missedPackets + " missed packets"); | |
send(lastSentPacket, client, replyPort); | |
client.receive(receivedPacket); | |
reply = new String(receivedPacket.getData(), StandardCharsets.US_ASCII).substring(0,receivedPacket.getLength()); | |
receiveStream.reset(); | |
receiveStream.write(reply.getBytes("US-ASCII")); | |
receiveData = receiveStream.toByteArray(); | |
lastReceivedPacket = receiveStream.toByteArray(); | |
/* | |
if(block==128 && receiveData[3] == 63) | |
block = 62; | |
*/ | |
replyPort = receivedPacket.getPort(); | |
break; | |
} | |
catch(SocketTimeoutException e) | |
{ | |
Client.timeouts++; | |
if(Client.timeouts>Client.TIMEOUTS_MAX) | |
{ | |
System.out.println("Maximum number of attempts reached. Ending program."); | |
return; | |
} | |
System.out.println("Timed out, retrying...\nNumber of attemps: " + Client.timeouts); | |
} | |
} | |
} | |
} | |
else | |
{ | |
block++; | |
} | |
} | |
System.out.println("\nFile transfer complete."); | |
} | |
} | |
catch(Exception e) | |
{ | |
System.out.println(e.toString()); | |
} | |
return; | |
} | |
public static void send(byte[] response, DatagramSocket client, int port) | |
{ | |
try | |
{ | |
InetAddress IP = InetAddress.getByName(Client.serverAddress); | |
DatagramPacket packetToSend = new DatagramPacket( | |
response, | |
response.length, | |
IP, | |
port | |
); | |
client.send(packetToSend); | |
} | |
catch(Exception e) | |
{ | |
System.out.println(e.toString()); | |
} | |
} | |
public static void debug(String output) | |
{ | |
System.out.println(output); | |
} | |
public static void debug(byte[] array) | |
{ | |
String debug = ""; | |
for(int x = 0; x < array.length; x++) | |
{ | |
debug += " " + array[x]; | |
} | |
System.out.println(debug); | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment