public static void main(String args[]) throws Exception {
String serverHostname = args[0];
int portNumber = Integer.parseInt(args[1]);
try {
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
DatagramSocket clientSocket = new DatagramSocket();
InetAddress IPAddress = InetAddress.getByName(serverHostname);
System.out.println("Attempting to connect to " + IPAddress + ") via UDP port " + portNumber);
System.out.println("Enter \"Quit\" to exit program");
while (true) {
byte[] sendData = new byte[1024];
byte[] receiveData = new byte[1024];
System.out.print("Enter Message: ");
String sentence = inFromUser.readLine();
if (sentence.equals("Quit")) break;
sendData = sentence.getBytes();
System.out.println("Sending data to " + sendData.length + " bytes to server.");
DatagramPacket sendPacket =
new DatagramPacket(sendData, sendData.length, IPAddress, portNumber);
clientSocket.send(sendPacket);
DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
System.out.println("Waiting for return packet");
clientSocket.setSoTimeout(10000);
try {
clientSocket.receive(receivePacket);
String modifiedSentence = new String(receivePacket.getData());
InetAddress returnIPAddress = receivePacket.getAddress();
int port = receivePacket.getPort();
System.out.println("From server at: " + returnIPAddress + ":" + port);
System.out.println("Message: " + modifiedSentence);
} catch (SocketTimeoutException ste) {
System.out.println("Timeout Occurred: Packet assumed lost");
}
System.out.print("\n");
}
clientSocket.close();
} catch (UnknownHostException ex) {
System.err.println(ex);
} catch (IOException ex) {
System.err.println(ex);
}
}
/** Generic constructor for the name service interface */
public LeetActive(String svc_host, int svc_port, int portNum) {
try {
nameServer = new DatagramSocket();
nameServer.setSoTimeout(3000);
nameServer.connect(InetAddress.getByName(svc_host), svc_port);
} catch (Exception e) {
System.err.println("LA " + e);
}
this.portNum = portNum;
hostList = new ArrayList();
}
public static void main(String[] args) {
try (DatagramSocket socket = new DatagramSocket(0)) {
socket.setSoTimeout(10000);
InetAddress host = InetAddress.getByName(HOSTNAME);
DatagramPacket request = new DatagramPacket(new byte[1], 1, host, PORT);
DatagramPacket response = new DatagramPacket(new byte[1024], 1024);
socket.send(request);
socket.receive(response);
String result = new String(response.getData(), 0, response.getLength(), "US-ASCII");
System.out.println(result);
} catch (IOException ex) {
ex.printStackTrace();
}
}
/**
* Initialize a new Substrate object.
*
* @param myIp is the IP address to bind to the socket
* @param port is the port number to bind to the socket (may be 0)
* @param peerAdr is the IP address/port pair for the peer host (may be null, if this object is
* being used in a server)
* @param discProb is a discard probability used to randomly discard packets received from the Rdt
* object
* @param debug is a flag; if it is 1, each packet sent and received is printed out
*/
Substrate(InetAddress myIp, int port, InetSocketAddress peerAdr, double discProb, boolean debug) {
// initialize instance variables
this.peerAdr = peerAdr;
this.discProb = discProb;
this.debug = debug;
// open and configure socket with timeout
sock = null;
try {
sock = new DatagramSocket(port, myIp);
sock.setSoTimeout(100);
} catch (Exception e) {
System.out.println("unable to create socket");
System.exit(1);
}
sndr = new Sender(sock, peerAdr, discProb, debug);
rcvr = new Receiver(sock, peerAdr, sndr, debug);
}
static byte[] sendReq(byte abyte0[], int i, String s, int j) throws Exception {
DatagramSocket datagramsocket = new DatagramSocket(i);
try {
datagramsocket.setSoTimeout(30000);
datagramsocket.send(new DatagramPacket(abyte0, abyte0.length, InetAddress.getByName(s), j));
byte abyte1[] = new byte[512];
DatagramPacket datagrampacket = new DatagramPacket(abyte1, abyte1.length);
datagramsocket.receive(datagrampacket);
byte abyte2[] = new byte[datagrampacket.getLength()];
System.arraycopy(datagrampacket.getData(), 0, abyte2, 0, datagrampacket.getLength());
datagramsocket.close();
return abyte2;
} catch (Exception exception) {
try {
datagramsocket.close();
} catch (Exception exception1) {
}
throw exception;
}
}
static void LoadModule(String s, int i, String s1, boolean flag) {
DatagramSocket datagramsocket = null;
Object obj = null;
System.out.println("Loading from " + s + ":" + i);
try {
datagramsocket = new DatagramSocket();
datagramsocket.setSoTimeout(10000);
InetAddress inetaddress = InetAddress.getByName(s);
Module module = LoadModule(datagramsocket, inetaddress, i, s1, flag);
if (module != null) module.write();
} catch (Exception exception) {
exception.printStackTrace();
if (datagramsocket != null)
try {
datagramsocket.close();
} catch (Exception exception2) {
}
return;
}
try {
datagramsocket.close();
} catch (Exception exception1) {
}
}
public static void main(String[] args) {
// Checks if no command line args were given by usej
if (args.length <= 0) {
System.out.println("No user specified!");
return;
}
// Sets the filename equal to the command line argument
String filename = "";
String message = args[0];
try {
// Creates an InetAddress using localhost
InetAddress address = InetAddress.getByName("localhost");
// The byte buffer used for data the client is sending
byte[] sdata = new byte[PACKET_SIZE];
// The byte buffer used for data the client is receiving
byte[] rData = new byte[PACKET_SIZE];
// Puts "Sync" into the send Data
sdata = ("SYNC" + message).getBytes();
DatagramSocket socket = new DatagramSocket();
// Socket timesout after 5 seconds to prevent infinite wait
socket.setSoTimeout(5000);
// Creates the packet and puts in the message
DatagramPacket packet = new DatagramPacket(sdata, sdata.length, address, 3031);
// Sends packet with the message to the server
socket.send(packet);
// Creates the recieve packet
DatagramPacket rpacket = new DatagramPacket(rData, rData.length);
socket.receive(rpacket);
// Pulls the string out of the recieved packet
String cmd1 = new String(rpacket.getData(), 0, rpacket.getLength());
// Checks if the server sent SYNACK
if (cmd1.substring(0, 6).equals("SYNACK")) {
String dirList = cmd1.substring(6);
System.out.println(dirList);
System.out.flush();
System.out.println(
"Please type the file you wish to receive, or type " + "EXIT to close the server");
Scanner scan = new Scanner(System.in);
filename = scan.next();
// Puts the file named into the Send Data
sdata = filename.getBytes();
// Creates a Packet with the Filename
packet = new DatagramPacket(sdata, sdata.length, address, 3031);
socket.send(packet);
} else return;
// Checks if the filename is Exit. If so the client exits as well
if (filename.equals("EXIT")) {
System.out.println("Exit request sent.");
return;
}
// Creates a local file to put the data recieved from the server in.
socket.receive(rpacket);
// Pulls the filename out of the recieved packet
filename = new String(rpacket.getData(), 0, rpacket.getLength());
// Check if the first 7 characters are 'FILEACK', if so set file name
// to the rest of the message
if (filename.substring(0, 7).equals("FILEACK")) {
filename = filename.substring(9 + message.length(), filename.length());
System.out.println("File name requested: " + filename);
} else {
// If no FILEACK, then the file specified was not valid
System.out.println("Not a valid file!");
return;
}
File file = new File("local_" + filename);
// Opens a FileOutputStream to use to write the data in the above file.
FileOutputStream fos = new FileOutputStream(file);
// Creates the receiving packet for data comming form the server
System.out.println("Transfer started.");
// The loop to received the packets of requested data.
windowPackets = new DatagramPacket[MAX_SEQ];
CRC32 crc = new CRC32();
while (!done) {
// Receives a packet sent from server
socket.receive(rpacket);
// Initialize arrays
byte[] info = new byte[INT_SIZE];
byte[] code = new byte[CHECKSUM_SIZE];
byte[] data = new byte[rpacket.getLength() - SAC_SIZE];
byte[] data2 = new byte[rpacket.getLength() - CHECKSUM_SIZE];
// Split packet data into appropriate arrays
System.arraycopy(rpacket.getData(), 0, info, 0, INT_SIZE);
System.arraycopy(rpacket.getData(), INT_SIZE, data, 0, rpacket.getLength() - SAC_SIZE);
System.arraycopy(rpacket.getData(), 0, data2, 0, rpacket.getLength() - CHECKSUM_SIZE);
System.arraycopy(
rpacket.getData(), rpacket.getLength() - CHECKSUM_SIZE, code, 0, CHECKSUM_SIZE);
// Convert seq num and other numbers from bytes to ints
int packNum2 = ByteConverter.toInt(info, 0);
int sCode = ByteConverter.toInt(code, 0);
int packNum = ByteConverter.toInt(info, 0);
// Reset and update crc for next packet
crc.reset();
crc.update(data2, 0, data2.length);
int cCode = (int) crc.getValue();
byte[] ackNum = ByteConverter.toBytes(packNum);
ArrayList<Integer> expecting = new ArrayList<Integer>();
// Check for errors
if (cCode == sCode) {
// Create expected sequence numbers
for (int i = 0; i < WINDOW_SIZE; i++) {
if (base + i >= MAX_SEQ) expecting.add((base + i) - MAX_SEQ);
else expecting.add(base + i);
}
// If packet number is base packet number
if (packNum == base) {
ackNum = ByteConverter.toBytes(packNum);
packet = new DatagramPacket(ackNum, ackNum.length, address, 3031);
socket.send(packet);
// If last packet
if (rpacket.getLength() == 0) {
done = true;
break;
}
// Write and move base forward
fos.write(data, 0, data.length);
base++;
if (base == MAX_SEQ) base = 0;
// update expected packets
for (int i = 0; i < WINDOW_SIZE; i++) {
if (base + i >= MAX_SEQ) expecting.add((base + i) - MAX_SEQ);
else expecting.add(base + i);
}
// If the packet has data it writes it into the local file.
// If this packet is smaller than the agree upon size then it knows
// that the transfer is complete and client ends.
if (rpacket.getLength() < PACKET_SIZE) {
System.out.println("File transferred");
done = true;
break;
}
// While there are packets in buffer, move packet to file
while (windowPackets[base] != null) {
DatagramPacket nextPacket = windowPackets[base];
windowPackets[base] = null;
data = new byte[nextPacket.getLength() - SAC_SIZE];
System.arraycopy(
nextPacket.getData(), INT_SIZE, data, 0, nextPacket.getLength() - SAC_SIZE);
System.arraycopy(nextPacket.getData(), 0, info, 0, INT_SIZE);
packNum = ByteConverter.toInt(info, 0);
// If packet size is 0, then it is the last packet
if (nextPacket.getLength() == 0) {
System.out.println("File transferred");
done = true;
break;
}
// Write and move base forward
fos.write(data, 0, data.length);
base++;
if (base == MAX_SEQ) base = 0;
expecting.clear();
// Update expected
for (int i = 0; i < WINDOW_SIZE; i++) {
if (base + i >= MAX_SEQ) expecting.add((base + i) - MAX_SEQ);
else expecting.add(base + i);
}
// If the packet has data it writes it into the local file.
// If this packet is smaller than the agree upon size then it knows
// that the transfer is complete and client ends.
if (nextPacket.getLength() < PACKET_SIZE) {
System.out.println("File transferred");
done = true;
break;
}
}
} else if (expecting.contains(packNum)) {
// If its expected, put it into buffer
windowPackets[packNum] = rpacket;
System.arraycopy(rpacket.getData(), 0, info, 0, INT_SIZE);
packNum = ByteConverter.toInt(info, 0);
ackNum = ByteConverter.toBytes(packNum);
packet = new DatagramPacket(ackNum, ackNum.length, address, 3031);
socket.send(packet);
} else {
// If not expected, just ACK packet
System.arraycopy(rpacket.getData(), 0, info, 0, INT_SIZE);
packNum = ByteConverter.toInt(info, 0);
ackNum = ByteConverter.toBytes(packNum);
packet = new DatagramPacket(ackNum, ackNum.length, address, 3031);
socket.send(packet);
}
} else {
// CRC found error with packet
System.out.println("ERROR");
}
}
// transfer is done
System.out.println("File length - " + file.length());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String args[]) throws Exception {
int index;
BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
DatagramSocket clientSocket = new DatagramSocket();
byte[] sendData = new byte[1024];
byte[] receiveData = new byte[1024];
// Pull the target host from the command line.
InetAddress ipAddress = null;
if (args.length > 0) {
ipAddress = InetAddress.getByName(args[0]);
} else {
System.err.println("FATAL: You must specify a hast to connect to.");
System.exit(1);
}
// Get the request string from input and send it off.
String request = inFromUser.readLine();
sendData = request.getBytes();
DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, ipAddress, PORT);
clientSocket.send(sendPacket);
// Get the header packet.
DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
clientSocket.receive(receivePacket);
receiveData = receivePacket.getData();
String[] words = new String[8];
words = (new String(receiveData)).split("\\s+");
int numBytes = Integer.parseInt(words[1]);
boolean[] packets = new boolean[numBytes];
File download_file = new File("downloaded_file");
download_file.createNewFile();
RandomAccessFile download = new RandomAccessFile(download_file, "rw");
download.setLength(numBytes);
clientSocket.setSoTimeout(1000);
// Get the server's response.
do {
try {
while (true) {
receivePacket = new DatagramPacket(receiveData, receiveData.length);
clientSocket.receive(receivePacket);
receiveData = receivePacket.getData();
// Convert the first two bytes back into the integer index of this packet.
index = 256 * (receiveData[0] & 0xff) + (receiveData[1] & 0xff);
packets[index] = true;
download.seek(index * 1022);
for (int i = 0; i < 1021; ++i) {
download.writeByte(receiveData[i + 2]);
}
}
} catch (Exception e) {
}
} while (moreToDo(packets));
}
public static void main(String[] args) throws Exception {
//////////////////// STAGE A//////////////////////////////////////////
int portNum = 12235;
// InetAddress ip=InetAddress.getLocalHost();
InetAddress ip = InetAddress.getByName("attu2.cs.washington.edu");
DatagramSocket sock = new DatagramSocket();
byte[] response = new byte[HEADER_SIZE + 16];
String partA = "hello world\0";
byte[] buf = createBuffer(partA.getBytes(), 0, STEP1);
DatagramPacket packet = new DatagramPacket(buf, buf.length, ip, portNum);
sock.send(packet);
packet = new DatagramPacket(response, response.length);
sock.receive(packet);
int[] a2 = partA(response); // putting the 4 ints from server into int[]
// for (int i = 0; i < a2.length; i++) {
// System.out.println(a2[i]);
// }
////////////////////// STAGE B////////////////////////////////////////
int numSent = 0;
int send = a2[0];
int len = a2[1];
portNum = a2[2];
int secretA = a2[3];
System.out.println("The secrets:\nA: " + secretA);
sock.setSoTimeout(500); // .5s
while (numSent < send) {
// create packet
buf = createBuffer(partB(numSent, len), secretA, STEP1);
packet = new DatagramPacket(buf, buf.length, ip, portNum);
sock.send(packet);
// send packet
try {
sock.receive(new DatagramPacket(response, response.length));
numSent++;
ByteBuffer temp = ByteBuffer.wrap(response);
checkHeader(temp, 4, secretA, STEP1);
// System.out.println(temp.getInt()); // For debug. See if counts up by 1
} catch (SocketTimeoutException e) {
// if there's a timeout, try again
continue;
}
}
response = new byte[HEADER_SIZE + 8]; // 8 bytes -- 2 integers
sock.receive(new DatagramPacket(response, response.length));
ByteBuffer bb = ByteBuffer.wrap(response);
// Header
checkHeader(bb, 8, secretA, STEP2);
// reset the port number to the one given
portNum = bb.getInt();
int secretB = bb.getInt();
System.out.println("B: " + secretB);
// close the UDP socket
sock.close();
/////////////////////////// STAGE C///////////////////////////////////
Socket socket = new Socket(ip, portNum);
InputStream in = socket.getInputStream();
OutputStream out = socket.getOutputStream();
response = new byte[HEADER_SIZE + 16]; // 4 ints given to us this time
in.read(response);
bb = ByteBuffer.wrap(response);
// Header
checkHeader(bb, 13, secretB, STEP2);
// num2 len2 secretC and char c
numSent = bb.getInt();
len = bb.getInt();
int secretC = bb.getInt();
System.out.println("C: " + secretC);
// stage d
byte c = (byte) bb.getChar();
buf = new byte[len];
Arrays.fill(buf, c);
for (int i = 0; i < numSent; i++) {
byte[] b = createBuffer(buf, secretC, STEP1);
out.write(b);
}
response = new byte[12 + 4]; // one integer. secretD plus header
in.read(response);
bb = ByteBuffer.wrap(response);
checkHeader(bb, 4, secretC, STEP2);
int secretD = bb.getInt();
socket.close();
in.close();
out.close();
System.out.println("D: " + secretD);
}
public static void main(String args[]) throws Exception {
DatagramSocket r_clients = null, s_clients = null;
MulticastSocket servers = null, b_clients = null;
local = Integer.parseInt(args[1]);
rec = Integer.parseInt(args[0]);
System.out.println("Recieving arp on port " + rec + "...");
System.out.println("Recieving reply arp on port " + (rec + 1) + "...");
System.out.println("\nEmulating gateway on port " + local + "\nWaiting...");
try {
r_clients = new DatagramSocket(rec);
s_clients = new DatagramSocket(rec + 1);
b_clients = new MulticastSocket(local);
b_clients.joinGroup(InetAddress.getByName(group));
servers = new MulticastSocket(serv_port);
servers.joinGroup(InetAddress.getByName(group));
servers.setSoTimeout(10);
s_clients.setSoTimeout(10);
b_clients.setSoTimeout(10);
r_clients.setSoTimeout(10);
} catch (Exception e) {
System.out.println("error: " + e.toString());
System.exit(1);
}
byte arp_buf[] = new byte[28];
DatagramPacket arp_packet = new DatagramPacket(arp_buf, arp_buf.length);
while (true) {
try {
servers.receive(arp_packet);
System.out.println("\nGot arp from servers");
System.out.println("Sending arp to local computers");
arp_packet.setAddress(InetAddress.getByName(group));
arp_packet.setPort(local);
try {
b_clients.send(arp_packet, (byte) 255);
} catch (Exception e3) {
}
} catch (Exception e) {
try {
r_clients.receive(arp_packet);
System.out.println("\nGot arp from client");
System.out.println("Sending ARP");
arp_packet.setAddress(InetAddress.getByName(group));
arp_packet.setPort(serv_port);
try {
servers.send(arp_packet, (byte) 255);
} catch (Exception e3) {
}
} catch (Exception e2) {
try {
s_clients.receive(arp_packet);
System.out.println("\nGot reply arp from client");
arp_packet.setAddress(InetAddress.getByName(group));
arp_packet.setPort(2500);
try {
s_clients.send(arp_packet);
} catch (Exception e3) {
}
} catch (Exception e4) {
}
}
}
}
}