/// <summary>
/// Process INFORM message type.
/// </summary>
private void DhcpInform(DhcpMessageEventArgs args)
{
#region Pre-Processing
// Start pre-process validation
// if the client provided a ServerID option, then it MUST
// match our configured ServerID, otherwise ignore the request
InternetAddress serverIdentifier = new InternetAddress(args.RequestOptions.ServerIdentifier);
//InternetAddress localServerIdentifier = new InternetAddress(((IPEndPoint)_dhcpSocket.LocalEndPoint).Address.GetAddressBytes());
InternetAddress localServerIdentifier = new InternetAddress(this.InterfaceAddress);
if (!serverIdentifier.Equals(localServerIdentifier))
{
Logger.WriteDebug(this, "Ignoring INFORM message: "
+ "Requested ServerId: " + serverIdentifier.ToString()
+ " Local ServerId: " + localServerIdentifier.ToString());
return; // if processing should not continue
}
// End pre-Process validation
#endregion Pre-Processing
this.SendAck(args);
}
/// <summary>
/// Send response message back to remote client.
/// </summary>
private void SendReply(DhcpMessageEventArgs args)
{
// set global headers
args.ResponseMessage.Operation = OperationCode.BootReply;
args.ResponseMessage.Hardware = args.RequestMessage.Hardware;
args.ResponseMessage.HardwareAddressLength = args.RequestMessage.HardwareAddressLength;
args.ResponseMessage.SessionId = args.RequestMessage.SessionId;
args.ResponseMessage.Flags = args.RequestMessage.Flags;
args.ResponseMessage.RelayAgentAddress = args.RequestMessage.RelayAgentAddress;
args.ResponseMessage.ClientHardwareAddress = args.RequestMessage.ClientHardwareAddress;
if (!StringUtility.IsNullOrEmpty(this._serverName))
{
args.ResponseMessage.ServerName = Encoding.UTF8.GetBytes(this._serverName);
}
if (!StringUtility.IsNullOrEmpty(this._bootFileName))
{
args.ResponseMessage.BootFileName = Encoding.UTF8.GetBytes(this._bootFileName);
}
// set global options
//args.ResponseMessage.AddOption(DhcpOption.ServerIdentifier, ((IPEndPoint)_dhcpSocket.LocalEndPoint).Address.GetAddressBytes());
args.ResponseMessage.AddOption(DhcpOption.ServerIdentifier, (this.InterfaceAddress.GetAddressBytes()));
// determin the proper ip address and port for sendto
InternetAddress relayAgentAddress = args.RequestMessage.RelayAgentAddress;
InternetAddress clientAddress = args.RequestMessage.ClientAddress;
if (!relayAgentAddress.Equals(InternetAddress.Any))
{
args.Channel.RemoteEndpoint = new IPEndPoint(relayAgentAddress.ToIPAddress(), Constants.DHCP_SERVICE_PORT);
}
else
{
if (!clientAddress.Equals(InternetAddress.Any))
{
args.Channel.RemoteEndpoint = new IPEndPoint(clientAddress.ToIPAddress(), Constants.DHCP_CLIENT_PORT);
}
else
{
args.Channel.RemoteEndpoint = new IPEndPoint(InternetAddress.Broadcast.ToIPAddress(), Constants.DHCP_CLIENT_PORT);
}
}
try
{
args.Channel.SendTo(args.ResponseMessage.ToArray(), args.Channel.RemoteEndpoint);
Logger.WriteDebug(this, "PACKET with message id " +
args.ResponseMessage.SessionId.ToHexString("0x") + " successfully sent to client endpoint " +
args.Channel.RemoteEndpoint.ToString());
Logger.WriteDebug(args.ResponseMessage.ToString());
OnDhcpMessageSent(this, args);
}
catch (SocketException ex)
{
Logger.WriteError(this, ex.Message + "Socket Error Code: " + ex.ErrorCode.ToString(), ex);
}
catch (Exception ex)
{
Logger.WriteError(this, "Error Message:" + ex.Message.ToString(), ex);
}
}
/// <summary>
/// Process INFORM message type.
/// </summary>
private void DhcpInform(DhcpMessageEventArgs args)
{
#region Pre-Processing
// Start pre-process validation
// if the client provided a ServerID option, then it MUST
// match our configured ServerID, otherwise ignore the request
InternetAddress serverIdentifier = new InternetAddress(args.RequestOptions.ServerIdentifier);
//InternetAddress localServerIdentifier = new InternetAddress(((IPEndPoint)_dhcpSocket.LocalEndPoint).Address.GetAddressBytes());
InternetAddress localServerIdentifier = new InternetAddress(this.InterfaceAddress);
if (!serverIdentifier.Equals(localServerIdentifier))
{
Logger.WriteDebug(this, "Ignoring INFORM message: "
+ "Requested ServerId: " + serverIdentifier.ToString()
+ " Local ServerId: " + localServerIdentifier.ToString());
return; // if processing should not continue
}
// End pre-Process validation
#endregion Pre-Processing
this.SendAck(args);
}
/// <summary>
/// Process REQUEST message type.
/// </summary>
private void DhcpRequest(DhcpMessageEventArgs args)
{
RequestState requestState;
#region Pre-Processing
// Start pre-process validation
//---------------------------------------------------------------------
//| |INIT-REBOOT |SELECTING |RENEWING |REBINDING |
//---------------------------------------------------------------------
//|broad/unicast |broadcast |broadcast |unicast |broadcast |
//|server-ip |MUST NOT |MUST |MUST NOT |MUST NOT |
//|requested-ip |MUST |MUST |MUST NOT |MUST NOT |
//|ciaddr |zero |zero |IP address |IP address|
//---------------------------------------------------------------------
// first determine what KIND of request we are dealing with
if (args.RequestMessage.ClientAddress.Equals(InternetAddress.Any))
{
// the ciAddr MUST be 0.0.0.0 for Init-Reboot and Selecting
if (args.RequestOptions.AddressRequest == null)
{
// init-reboot MUST NOT have server-id option
requestState = RequestState.InitReboot;
}
else
{
// selecting MUST have server-id option
requestState = RequestState.Selecting;
}
}
else
{
// the ciAddr MUST NOT be 0.0.0.0 for Renew and Rebind
if (!args.RequestMessage.IsBroadcast)
{
// renew is unicast
// NOTE: this will not happen if the v4 broadcast interface used at startup,
// but handling of DHCPv4 renew/rebind is the same anyway
requestState = RequestState.Renewing;
}
else
{
// rebind is broadcast
requestState = RequestState.Rebinding;
}
}
if ((requestState == RequestState.InitReboot) || (requestState == RequestState.Selecting))
{
if (args.RequestOptions.AddressRequest == null)
{
Logger.WriteDebug(this, "Ignoring REQUEST " + RequestStateString.GetName(requestState) + " message: Requested IP option is null");
return; // if processing should not continue
}
if (requestState == RequestState.Selecting)
{
// if the client provided a ServerID option, then it MUST
// match our configured ServerID, otherwise ignore the request
InternetAddress serverIdentifier = new InternetAddress(args.RequestOptions.ServerIdentifier);
//InternetAddress localServerIdentifier = new InternetAddress(((IPEndPoint)_dhcpSocket.LocalEndPoint).Address.GetAddressBytes());
InternetAddress localServerIdentifier = new InternetAddress(this.InterfaceAddress);
if (!serverIdentifier.Equals(localServerIdentifier))
{
Logger.WriteDebug(this, "Ignoring REQUEST " + RequestStateString.GetName(requestState) + " message: "
+ "Requested ServerId: " + serverIdentifier.ToString()
+ " Local ServerId: " + localServerIdentifier.ToString());
return; // if processing should not continue
}
}
}
else
{ // type == Renewing or Rebinding
if (args.RequestOptions.AddressRequest != null)
{
Logger.WriteDebug(this, "Ignoring REQUEST " + RequestStateString.GetName(requestState) + " message: "
+ "Requested IP option is not null");
return; // if processing should not continue
}
}
// End pre-process validation
#endregion Pre-Processing
Logger.WriteDebug(this, "Processing REQUEST " + RequestStateString.GetName(requestState) + " message");
//TODO: should also check for ip on link
if (args.RequestOptions.AddressRequest != null)
{
args.ResponseBinding.Address = new InternetAddress(args.RequestOptions.AddressRequest);
}
BindingLease assignment = _bindmgr.GetAssigned(args.ResponseBinding);
if (assignment == null)
{
args.ResponseMessage.AddOption(DhcpOption.DhcpMessage, Encoding.UTF8.GetBytes("No binding available for client"));
Logger.WriteDebug(this, "REQUEST " + RequestStateString.GetName(requestState) + " message: No binding available for client sending NAK");
this.SendNak(args);
}
else
{
this.SendAck(args, assignment);
this.OnLeaseAcknowledged(this, new DhcpLeaseEventArgs(assignment.Address, assignment));
}
}
/// <summary>
/// Process REQUEST message type.
/// </summary>
private void DhcpRequest(DhcpMessageEventArgs args)
{
RequestState requestState;
#region Pre-Processing
// Start pre-process validation
//---------------------------------------------------------------------
//| |INIT-REBOOT |SELECTING |RENEWING |REBINDING |
//---------------------------------------------------------------------
//|broad/unicast |broadcast |broadcast |unicast |broadcast |
//|server-ip |MUST NOT |MUST |MUST NOT |MUST NOT |
//|requested-ip |MUST |MUST |MUST NOT |MUST NOT |
//|ciaddr |zero |zero |IP address |IP address|
//---------------------------------------------------------------------
// first determine what KIND of request we are dealing with
if (args.RequestMessage.ClientAddress.Equals(InternetAddress.Any))
{
// the ciAddr MUST be 0.0.0.0 for Init-Reboot and Selecting
if (args.RequestOptions.AddressRequest == null)
{
// init-reboot MUST NOT have server-id option
requestState = RequestState.InitReboot;
}
else
{
// selecting MUST have server-id option
requestState = RequestState.Selecting;
}
}
else
{
// the ciAddr MUST NOT be 0.0.0.0 for Renew and Rebind
if (!args.RequestMessage.IsBroadcast)
{
// renew is unicast
// NOTE: this will not happen if the v4 broadcast interface used at startup,
// but handling of DHCPv4 renew/rebind is the same anyway
requestState = RequestState.Renewing;
}
else
{
// rebind is broadcast
requestState = RequestState.Rebinding;
}
}
if ((requestState == RequestState.InitReboot) || (requestState == RequestState.Selecting))
{
if (args.RequestOptions.AddressRequest == null)
{
Logger.WriteDebug(this, "Ignoring REQUEST " + RequestStateString.GetName(requestState) + " message: Requested IP option is null");
return; // if processing should not continue
}
if (requestState == RequestState.Selecting)
{
// if the client provided a ServerID option, then it MUST
// match our configured ServerID, otherwise ignore the request
InternetAddress serverIdentifier = new InternetAddress(args.RequestOptions.ServerIdentifier);
//InternetAddress localServerIdentifier = new InternetAddress(((IPEndPoint)_dhcpSocket.LocalEndPoint).Address.GetAddressBytes());
InternetAddress localServerIdentifier = new InternetAddress(this.InterfaceAddress);
if (!serverIdentifier.Equals(localServerIdentifier))
{
Logger.WriteDebug(this, "Ignoring REQUEST " + RequestStateString.GetName(requestState) + " message: "
+ "Requested ServerId: " + serverIdentifier.ToString()
+ " Local ServerId: " + localServerIdentifier.ToString());
return; // if processing should not continue
}
}
}
else
{ // type == Renewing or Rebinding
if (args.RequestOptions.AddressRequest != null)
{
Logger.WriteDebug(this, "Ignoring REQUEST " + RequestStateString.GetName(requestState) + " message: "
+ "Requested IP option is not null");
return; // if processing should not continue
}
}
// End pre-process validation
#endregion Pre-Processing
Logger.WriteDebug(this, "Processing REQUEST " + RequestStateString.GetName(requestState) + " message");
//TODO: should also check for ip on link
if (args.RequestOptions.AddressRequest != null)
{
args.ResponseBinding.Address = new InternetAddress(args.RequestOptions.AddressRequest);
}
BindingLease assignment = _bindmgr.GetAssigned(args.ResponseBinding);
if (assignment == null)
{
args.ResponseMessage.AddOption(DhcpOption.DhcpMessage, Encoding.UTF8.GetBytes("No binding available for client"));
Logger.WriteDebug(this, "REQUEST " + RequestStateString.GetName(requestState) + " message: No binding available for client sending NAK");
this.SendNak(args);
}
else
{
this.SendAck(args, assignment);
this.OnLeaseAcknowledged(this, new DhcpLeaseEventArgs(assignment.Address, assignment));
}
}
