private async Task DhcpRequest(DhcpMessage message)
{
await _requestLock.WaitAsync().ConfigureAwait(false);
try
{
// Client specified an address they would like
if (message.Options.ContainsKey(DhcpOptionCode.RequestedIpAddress))
{
await KeepAddressRequest(message).ConfigureAwait(false);
}
else
{
var clientAddress = message.ClientIPAddress;
if (clientAddress.Equals(IPAddress.Parse("0.0.0.0")))
{
// A DHCP REQ should have an address
throw new Exception("A DHCP Request must have an address specified");
}
await LeaseManager.AddLease(clientAddress, message.ClientHardwareAddress, message.HostName)
.ConfigureAwait(false);
await this.SendAck(message, clientAddress).ConfigureAwait(false);
}
}
catch (Exception ex)
{
Log.Error(ex.Message);
}
_requestLock.Release();
}
private async Task KeepAddressRequest(DhcpMessage message)
{
var addressRequestData = message.Options[DhcpOptionCode.RequestedIpAddress];
var addressRequest = new IPAddress(addressRequestData);
Log.Debug($"[REQUEST] {message.ClientHardwareAddress} has requested to keep it's IP Address '{addressRequest}'");
if (addressRequest.IsInSameSubnet(Configuration.StartIpAddress, Configuration.SubnetMask) == false)
{
Log.Debug($"[REQUEST] {message.ClientHardwareAddress} request for '{addressRequest}' has been DENIED due to subnet mismatch");
await this.SendNak(message, addressRequest).ConfigureAwait(false);
return;
}
var keepReservationResponse = await LeaseManager.KeepLeaseRequest(addressRequest, message.ClientHardwareAddress, message.HostName);
if (keepReservationResponse)
{
await this.SendAck(message, addressRequest).ConfigureAwait(false);
Log.Debug($"[REQUEST] {message.ClientHardwareAddress} has been approved!");
return;
}
await this.SendNak(message, addressRequest).ConfigureAwait(false);
Log.Debug($"[REQUEST] {message.ClientHardwareAddress} has been DENIED.");
}
private async Task DhcpDiscover(DhcpMessage message)
{
var addressRequest = await LeaseManager.GetNextLease()
.ConfigureAwait(false);
await this.SendOffer(message, addressRequest)
.ConfigureAwait(false);
}
