public static void checkHeader(ByteBuffer b, int length, int psecret, short step) {
int l = b.getInt();
int ps = b.getInt();
int s = b.getShort();
b.getShort(); // the student number, which I am not checking.
if (l != length) {
System.out.println("Packet length was " + l + " instead of " + length);
}
if (ps != psecret) {
System.out.println("Psecret was " + ps + " instead of " + psecret);
}
if (s != step) {
System.out.println("Packet length was " + s + " instead of " + step);
}
}
static byte[] extractByteArray(ByteBuffer buf) {
int len = buf.getInt();
if (len > 0) {
byte[] a = new byte[len];
buf.get(a, 0, len);
return a;
} else return new byte[0];
}
private void recv(SocketChannel sc, ClientInfo ci) throws IOException {
ci.channel.read(ci.inBuf);
ByteBuffer tmpBuf = ci.inBuf.duplicate();
tmpBuf.flip();
int bytesProcessed = 0;
boolean doneLoop = false;
while (!doneLoop) {
byte b;
try {
b = tmpBuf.get();
} catch (BufferUnderflowException bue) {
// Processed all data in buffer
ci.inBuf.clear();
doneLoop = true;
break;
}
switch (b) {
case TypeServerConstants.WELCOME:
bytesProcessed++;
break;
case TypeServerConstants.GET_STRING_REQUEST:
bytesProcessed++;
if (ci.outputPending) {
// Client is backed up. We can't append to
// the byte buffer because it's in the wrong
// state. We could allocate another buffer
// here and change our send method to know
// about multiple buffers, but we'll just
// assume that the client is dead
break;
}
ci.outBuf.put(TypeServerConstants.GET_STRING_RESPONSE);
ByteBuffer strBuf = encoder.encode(testString);
ci.outBuf.putShort((short) strBuf.remaining());
ci.outBuf.put(strBuf);
ci.outBuf.flip();
send(sc, ci);
break;
case TypeServerConstants.GET_STRING_RESPONSE:
int startPos = tmpBuf.position();
try {
int nBytes = tmpBuf.getInt();
byte[] buf = new byte[nBytes];
tmpBuf.get(buf);
bytesProcessed += buf.length + 5;
String s = new String(buf);
// Send the string to the GUI
break;
} catch (BufferUnderflowException bue) {
// Processed all available data
ci.inBuf.position(ci.inBuf.position() + bytesProcessed);
doneLoop = true;
}
break;
}
}
}
// Takes the byte array received from the server and parses.
// The server responds with a UDP packet containing 4 integers. The
// integer array returned contains has those 4 integers.
public static int[] partA(byte[] response) {
ByteBuffer bb = ByteBuffer.wrap(response);
checkHeader(bb, 16, 0, STEP2);
int[] res = new int[4];
for (int i = 0; i < res.length; i++) {
res[i] = bb.getInt();
}
return res;
}
static byte[] extractByteString(ByteBuffer buf) {
int len = buf.getInt();
byte[] str = null;
if (len > 0) {
str = new byte[len];
buf.get(str, 0, len);
buf.get(); // trailing null
} else str = new byte[0];
return str;
}
static String extractString(ByteBuffer buf) throws java.io.UnsupportedEncodingException {
int len = buf.getInt();
byte[] str = null;
if (len > 0) {
str = new byte[len - 1];
;
buf.get(str, 0, len - 1);
buf.get(); // trailing null
} else str = new byte[0];
return new String(str, "UTF-8");
}
private synchronized DBMessage go(DBMessage msg, ByteDecoder decoder) throws IOException {
if (_sock == null) _open();
{
ByteBuffer out = msg.prepare();
while (out.remaining() > 0) _sock.write(out);
}
if (_pool != null) _pool._everWorked = true;
if (decoder == null) return null;
ByteBuffer response = decoder._buf;
if (response.position() != 0) throw new IllegalArgumentException();
int read = 0;
while (read < DBMessage.HEADER_LENGTH) read += _read(response);
int len = response.getInt(0);
if (len <= DBMessage.HEADER_LENGTH)
throw new IllegalArgumentException("db sent invalid length: " + len);
if (len > response.capacity())
throw new IllegalArgumentException(
"db message size is too big (" + len + ") " + "max is (" + response.capacity() + ")");
response.limit(len);
while (read < len) read += _read(response);
if (read != len) throw new RuntimeException("something is wrong");
response.flip();
return new DBMessage(response);
}
/**
* Handles control packet.
*
* @param data raw packet data that arrived on control PPID.
* @param sid SCTP stream id on which the data has arrived.
*/
private synchronized void onCtrlPacket(byte[] data, int sid) throws IOException {
ByteBuffer buffer = ByteBuffer.wrap(data);
int messageType = /* 1 byte unsigned integer */ 0xFF & buffer.get();
if (messageType == MSG_CHANNEL_ACK) {
if (logger.isDebugEnabled()) {
logger.debug(getEndpoint().getID() + " ACK received SID: " + sid);
}
// Open channel ACK
WebRtcDataStream channel = channels.get(sid);
if (channel != null) {
// Ack check prevents from firing multiple notifications
// if we get more than one ACKs (by mistake/bug).
if (!channel.isAcknowledged()) {
channel.ackReceived();
notifyChannelOpened(channel);
} else {
logger.warn("Redundant ACK received for SID: " + sid);
}
} else {
logger.error("No channel exists on sid: " + sid);
}
} else if (messageType == MSG_OPEN_CHANNEL) {
int channelType = /* 1 byte unsigned integer */ 0xFF & buffer.get();
int priority = /* 2 bytes unsigned integer */ 0xFFFF & buffer.getShort();
long reliability = /* 4 bytes unsigned integer */ 0xFFFFFFFFL & buffer.getInt();
int labelLength = /* 2 bytes unsigned integer */ 0xFFFF & buffer.getShort();
int protocolLength = /* 2 bytes unsigned integer */ 0xFFFF & buffer.getShort();
String label;
String protocol;
if (labelLength == 0) {
label = "";
} else {
byte[] labelBytes = new byte[labelLength];
buffer.get(labelBytes);
label = new String(labelBytes, "UTF-8");
}
if (protocolLength == 0) {
protocol = "";
} else {
byte[] protocolBytes = new byte[protocolLength];
buffer.get(protocolBytes);
protocol = new String(protocolBytes, "UTF-8");
}
if (logger.isDebugEnabled()) {
logger.debug(
"!!! "
+ getEndpoint().getID()
+ " data channel open request on SID: "
+ sid
+ " type: "
+ channelType
+ " prio: "
+ priority
+ " reliab: "
+ reliability
+ " label: "
+ label
+ " proto: "
+ protocol);
}
if (channels.containsKey(sid)) {
logger.error("Channel on sid: " + sid + " already exists");
}
WebRtcDataStream newChannel = new WebRtcDataStream(sctpSocket, sid, label, true);
channels.put(sid, newChannel);
sendOpenChannelAck(sid);
notifyChannelOpened(newChannel);
} else {
logger.error("Unexpected ctrl msg type: " + messageType);
}
}
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);
}
