internal override void ReceiveEvent(DhcpFormat !dhcp)
{
// Check if message is in response to our request
if (dhcp.BootMessageType != DhcpFormat.BootType.Reply ||
dhcp.TransactionID != client.TransactionID ||
dhcp.GetHardwareAddress() != client.MacAddress)
{
return;
}
IPv4 serverAddress = dhcp.NextServerIPAddress;
// Check if offered address is valid (ie not zero
// and below class E)
IPv4 offeredAddress = dhcp.YourIPAddress;
if (offeredAddress == IPv4.Any || offeredAddress.IsMulticast())
{
return;
}
// Check if message is an offer
SortedList offeredOptions = dhcp.GetOptions();
DhcpByteOption messageType
= offeredOptions[DhcpMessageType.OptionCode] as DhcpByteOption;
if (messageType == null ||
messageType.Value != (byte)DhcpFormat.MessageType.Offer)
{
return;
}
// Must have parameters
byte [] parameters = new byte [] {
DhcpSubnetMask.OptionCode,
DhcpRouter.OptionCode,
DhcpDomainNameServer.OptionCode
};
foreach (byte p in parameters)
{
IDhcpOption ido = offeredOptions[p] as IDhcpOption;
if (ido == null)
{
return;
}
}
client.CancelStateTimeout();
client.ChangeState(new DhcpClientStateRequesting(client,
serverAddress,
offeredAddress,
offeredOptions));
}
public void Receive(NetPacket packet)
{
packet.Reset();
Console.WriteLine("Received {0} bytes", packet.Length);
if (ValidHeaders(packet) == false)
{
SetState(ServerState.Failed);
return;
}
try {
DhcpFormat dhcp = DhcpFormat.Parse(packet);
SortedList options = dhcp.GetOptions();
DhcpByteOption message = options[DhcpMessageType.OptionCode]
as DhcpByteOption;
if (message == null)
{
Console.WriteLine("MessageType option not found");
SetState(ServerState.Failed);
return;
}
DhcpFormat.MessageType messageType =
(DhcpFormat.MessageType)message.Value;
if (DhcpFormat.IsRequestMessage(messageType) == false)
{
Console.WriteLine("Inappropriate message type: {0}",
message.Value);
SetState(ServerState.Failed);
return;
}
DhcpFormat.MessageType expected = expectActions[expectIndex, 0];
DhcpFormat.MessageType action = expectActions[expectIndex, 1];
expectIndex++;
if (messageType != expected)
{
Console.WriteLine("Unexpected message type: {0} != {1}",
messageType, expected);
SetState(ServerState.Failed);
return;
}
if (DhcpFormat.IsResponseMessage(action))
{
Respond(dhcp, action);
}
if (expectIndex == expectActions.Length / expectActions.Rank)
{
SetState(ServerState.Finished);
}
}
catch (Exception e) {
Console.WriteLine("Bad Dhcp packet: {0}", e);
SetState(ServerState.Failed);
}
}
