/**
* This method processes a DHCPC sending by client
*
* @param data to send
* @param server host
* @param server port
* @author key
* @version v0.01
*/
public void StartDHCPC(String inIface, String WantedIP)
throws CommunicationException, LowLinkException, InvalidNetworkLayerDeviceException,
TransportLayerException {
if (running) {
Close();
}
running = true;
completed = false;
iface = inIface;
Listen();
DHCPPacket d = new DHCPPacket();
d.op = 1;
xid = d.xid;
d.WantedIP = WantedIP;
d.ciaddr = mParentStack.getIPAddress(iface);
d.chaddr = mParentStack.getMACAddress(iface);
d.msgType = 1;
if (d.ciaddr == null) {
d.ciaddr = "";
}
String Data = d.toBytes();
resend = Data;
resendings = 0;
LayerInfo protInfo = new LayerInfo(getClass().getName());
protInfo.setObjectName(mParentStack.getParentNodeName());
protInfo.setDataType("DHCP client");
protInfo.setLayer("Application ");
protInfo.setDescription(
"Starting DHCP discover process on interface "
+ iface
+ "... Transaction ID is "
+ xid
+ ".");
Simulation.addLayerInfo(protInfo);
protInfo = new LayerInfo(getClass().getName());
protInfo.setObjectName(mParentStack.getParentNodeName());
protInfo.setDataType("DHCP client");
protInfo.setLayer("Application ");
protInfo.setDescription(
"Sending DHCPDISCOVER packet to 255.255.255.255 with op=1 chaddr='"
+ d.chaddr
+ "' ciaddr='"
+ d.ciaddr
+ "' preferred IP='"
+ WantedIP
+ "'.");
Simulation.addLayerInfo(protInfo);
mParentStack.getParentNode().startTimerTask(this, 5000);
SendData(appSock, "255.255.255.255", 67, Data);
}
@Override
public void Timer(int code) {
if (running) {
if (!completed) {
if (resend != "" && resendings++ < 5) {
LayerInfo protInfo = new LayerInfo(getClass().getName());
protInfo.setObjectName(mParentStack.getParentNodeName());
protInfo.setDataType("DHCP client");
protInfo.setLayer("Application ");
protInfo.setDescription("Resening DHCP packet to 255.255.255.255 due to timer.");
Simulation.addLayerInfo(protInfo);
try {
SendData(appSock, "255.255.255.255", 67, resend);
} catch (Exception e) {
}
}
} else {
// re-lease
}
}
}
/**
* This method recieves data from the other side.
*
* @param data to recv
* @author key
* @version v0.01
*/
@Override
public void RecvData(int sock, String Data) throws LowLinkException, TransportLayerException {
DHCPPacket p = new DHCPPacket();
if (!running) return;
p.fromBytes(Data);
if (p.op == 2 && p.xid == xid) {
switch (p.msgType) {
case 2: // OFFER
if (!completed) {
LayerInfo protInfo = new LayerInfo(getClass().getName());
protInfo.setObjectName(mParentStack.getParentNodeName());
protInfo.setDataType("DHCP client");
protInfo.setLayer("Application ");
protInfo.setDescription(
"Recieved DHCPOFFER(xid="
+ p.xid
+ ") from "
+ p.DHCPServer
+ " with op=2 yiaddr='"
+ p.yiaddr
+ "' lease time="
+ p.leaseTime
+ ".");
Simulation.addLayerInfo(protInfo);
DHCPPacket r = new DHCPPacket();
r.op = 1;
r.xid = xid;
r.msgType = 3;
DHCPServer = r.DHCPServer = p.DHCPServer;
r.WantedIP = p.yiaddr;
r.chaddr = mParentStack.getMACAddress(iface);
protInfo = new LayerInfo(getClass().getName());
protInfo.setObjectName(mParentStack.getParentNodeName());
protInfo.setDataType("DHCP client");
protInfo.setLayer("Application ");
protInfo.setDescription(
"Sending DHCPREQUEST(xid="
+ p.xid
+ ") packet to 255.255.255.255 with op=1 chaddr='"
+ r.chaddr
+ "' DHCP Server='"
+ r.DHCPServer
+ "' preferred IP='"
+ r.WantedIP
+ "'.");
Simulation.addLayerInfo(protInfo);
resend = r.toBytes();
try {
SendData(appSock, "255.255.255.255", 67, resend);
} catch (CommunicationException e) {
throw new TransportLayerException(e.toString());
}
}
break;
case 4: // DECLINE
// sleeping
break;
case 5: // ACK
if (!completed) {
// here set up interfaces...
LayerInfo protInfo = new LayerInfo(getClass().getName());
protInfo.setObjectName(mParentStack.getParentNodeName());
protInfo.setDataType("DHCP client");
protInfo.setLayer("Application ");
protInfo.setDescription(
"Recieved DHCPACK(xid="
+ p.xid
+ ") from "
+ p.DHCPServer
+ " with op=2 yiaddr='"
+ p.yiaddr
+ "' lease time="
+ p.leaseTime
+ " subnet mask='"
+ p.SubnetMask
+ "' default gateway='"
+ p.Gateway
+ "'.");
Simulation.addLayerInfo(protInfo);
protInfo = new LayerInfo(getClass().getName());
protInfo.setObjectName(mParentStack.getParentNodeName());
protInfo.setDataType("DHCP client");
protInfo.setLayer("Application ");
protInfo.setDescription("Updating " + iface + " IP configuration.");
Simulation.addLayerInfo(protInfo);
resend = "";
resendings = 0;
try {
mParentStack.setIPAddress(iface, p.yiaddr);
mParentStack.setCustomSubnetMask(iface, p.SubnetMask);
mParentStack.setDefaultGateway(p.Gateway);
} catch (Exception e) {
}
leaseTime = p.leaseTime;
DHCPServer = p.DHCPServer;
completed = true;
}
break;
}
} else {
// Invalid or not our packet; simply drop
LayerInfo protInfo = new LayerInfo(getClass().getName());
protInfo.setObjectName(mParentStack.getParentNodeName());
protInfo.setDataType("DHCP client");
protInfo.setLayer("Application ");
protInfo.setDescription("Recieved DHCP packet with invalid xid=" + p.xid + " and/or data.");
Simulation.addLayerInfo(protInfo);
}
}