/**
* Receives a datagram packet containing a DHCP Message into a DHCPMessage object.
*
* @return true if message is received, false if timeout occurs.
* @param outMessage DHCPMessage object to receive new message into
*/
public synchronized boolean receive(DHCPMessage outMessage) {
try {
DatagramPacket incoming = new DatagramPacket(new byte[packetSize], packetSize);
// gSocket.
receive(incoming); // block on receive for SO_TIMEOUT
outMessage.internalize(incoming.getData());
} catch (java.io.IOException e) {
return false;
} // end catch
return true;
}
private Object[] acquireAddress(int xid, byte hwaddr[], int sleepTime) {
Object results[] = new Object[5];
results[0] = "n/a";
results[1] = String.valueOf(0);
results[2] = "error";
results[3] = "no data";
results[4] = "no data";
int releaseTime = -1;
DHCPSocket socket = null;
DHCPMessage outMessage = new DHCPMessage();
DHCPMessage replyMessage = new DHCPMessage();
byte offeredAddr[] = new byte[4];
byte backupAddr[] = new byte[4];
Random r = new Random();
if ((socket = openSocket(socket)) == null) {
results[3] = results[4] = lastError;
return results;
}
outMessage.setChaddr(hwaddr);
if (IP.length() > 0) {
outMessage.setOption(50, stringToIP(IP));
}
for (int i = 0; i < 10; i++) {
if (!sendMessage(lastError, outMessage, socket, xid, 1)) {
results[3] = results[4] = lastError;
socket.close();
return results;
}
try {
Thread.sleep(sleepTime);
} catch (InterruptedException e) {
}
if (socket.receive(replyMessage)) {
if (checkOffer(replyMessage, xid)) {
offeredAddr = replyMessage.getYiaddr();
System.arraycopy(offeredAddr, 0, backupAddr, 0, 4);
break;
}
if (unavailable) {
results[3] = results[4] = lastError;
socket.close();
return results;
}
}
if (i == 9) {
results[3] = results[4] = "Timed out waiting for DHCPOFFER";
socket.close();
return results;
}
}
releaseTime = 1;
outMessage.setOption(54, replyMessage.getOption(54));
sendMessage(lastError, outMessage, socket, xid, 3, offeredAddr);
if (!socket.receive(replyMessage)) {
results[3] = results[4] = "Timed out waiting for DHCPACK";
socket.close();
return results;
}
if (replyMessage.getXid() != xid) {
results[3] = results[4] = "Received invalid DHCPACK from server";
socket.close();
return results;
}
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
outMessage.setCiaddr(backupAddr);
outMessage.setOption(50, new byte[4]);
outMessage.setOption(51, new byte[4]);
outMessage.setOption(54, replyMessage.getOption(54));
sendMessage(lastError, outMessage, socket, r.nextInt(), 7);
socket.close();
long totalDuration = System.currentTimeMillis() - startTime;
String stateString =
(new StringBuilder()).append("leased address ").append(ipToString(backupAddr)).toString();
String duration = (float) totalDuration / 1000F + " sec";
results[0] = results[1] = duration;
results[2] = "ok";
results[3] =
(new StringBuilder()).append("leased address ").append(ipToString(backupAddr)).toString();
results[4] = stateString;
return results;
}