/// <summary>
/// Process DECLINE message type.
/// </summary>
private void DhcpDecline(DhcpMessageEventArgs args)
{
#region Pre-Processing
// Start pre-process validation
if (args.RequestOptions.AddressRequest == null)
{
Logger.WriteDebug(this, "Ignoring DECLINE message: "
+ "Requested IP option is null");
return; // if processin should not continue
}
// End pre-Process validation
#endregion Pre-Processing
if (args.RequestOptions.AddressRequest != null)
{
args.ResponseBinding.Address = new InternetAddress(args.RequestOptions.AddressRequest);
}
BindingLease lease = _bindmgr.SetDeclined(args.ResponseBinding);
// no reply for v4 decline
if (lease == null)
{
Logger.WriteDebug(this, "DECLINE message: "
+ "No binding available for client to decline");
}
else
{
this.OnLeaseDeclined(this, new DhcpLeaseEventArgs(lease.Address, lease));
}
}
/// <summary>
/// Process RELEASE message type.
/// </summary>
private void DhcpRelease(DhcpMessageEventArgs args)
{
#region Pre-Processing
// Start pre-process validation
if (args.RequestMessage.ClientAddress.Equals(InternetAddress.Any))
{
Logger.WriteDebug(this, "Ignoring RELEASE message: "
+ "ciAddr is zero");
return; // if processing should not continue
}
// End pre-Process validation
#endregion Pre-Processing
BindingLease lease = _bindmgr.SetReleased(args.ResponseBinding);
// no reply for v4 release
if (lease == null)
{
Logger.WriteDebug(this, "RELEASE message: "
+ "No binding available for client to release");
}
else
{
this.OnLeaseReleased(this, new DhcpLeaseEventArgs(lease.Address, lease));
}
}
/// <summary>
/// Set client response lease options.
/// </summary>
private void SetClientOptions(DhcpMessageEventArgs args)
{
// set client response options
args.ResponseMessage.AddOption(DhcpOption.SubnetMask, this._subnet.ToArray());
args.ResponseMessage.AddOption(DhcpOption.Router, this._gateway.ToArray());
if (!StringUtility.IsNullOrEmpty(this._dnsSuffix))
{
args.ResponseMessage.AddOption(DhcpOption.DomainNameSuffix, Encoding.UTF8.GetBytes(this._dnsSuffix));
}
if (this._dnsServers != null && this._dnsServers.Count > 0)
{
byte[] dnsServerAddresses = new byte[this._dnsServers.Count * 4];
for (Int32 i = 0; i < this._dnsServers.Count; i++)
{
InternetAddress ipAddressValue = (InternetAddress)this._dnsServers[i];
ipAddressValue.ToArray().CopyTo(dnsServerAddresses, i * 4);
}
args.ResponseMessage.AddOption(DhcpOption.DomainNameServer, dnsServerAddresses);
}
// set custom response options
if (this._options != null && this._options.Count > 0)
{
foreach (DictionaryEntry option in _options)
{
args.ResponseMessage.AddOption((DhcpOption)option.Key, (byte[])option.Value);
}
}
}
/// <summary>
/// Send NAK message back to remote client.
/// </summary>
private void SendNak(DhcpMessageEventArgs args)
{
// Set options
args.ResponseMessage.AddOption(DhcpOption.DhcpMessageType, (Byte)MessageType.Nak);
Logger.WriteInfo(this, "NAK (Negative Acknowledge) for message id " + args.RequestMessage.SessionId.ToHexString("0x") + " sent on thread(#" +
Thread.CurrentThread.ManagedThreadId + ")" + " with option message: " + ByteUtility.GetSafeString(args.ResponseMessage.GetOptionData(DhcpOption.DhcpMessage)));
this.SendReply(args);
}
/// <summary>
/// Send ACK message back to remote client.
/// </summary>
private void SendAck(DhcpMessageEventArgs args, BindingLease lease)
{
// set header
args.ResponseMessage.AssignedAddress = lease.Address;
// set lease options
this.SetLeaseOptions(args);
this.SendAck(args);
}
/// <summary>
/// Send OFFER message back to remote client.
/// </summary>
private void SendOffer(DhcpMessageEventArgs args, BindingLease offer)
{
// set header
args.ResponseMessage.AssignedAddress = offer.Address;
args.ResponseMessage.NextServerAddress = args.ResponseMessage.NextServerAddress;
args.ResponseMessage.AddOption(DhcpOption.DhcpMessageType, (Byte)MessageType.Offer);
this.SetLeaseOptions(args);
this.SetClientOptions(args);
byte[] paramList = args.RequestOptions.ParameterList;
if (paramList != null)
{
args.ResponseMessage.OptionOrdering = paramList;
}
Logger.WriteInfo(this, "OFFER for message id " + args.RequestMessage.SessionId.ToHexString("0x") + " sent on thread(#" + Thread.CurrentThread.ManagedThreadId + ")");
this.SendReply(args);
}
/// <summary>
/// Send ACK message back to remote client.
/// </summary>
private void SendAck(DhcpMessageEventArgs args)
{
// set header
args.ResponseMessage.ClientAddress = args.RequestMessage.ClientAddress;
args.ResponseMessage.NextServerAddress = args.RequestMessage.NextServerAddress;
// set client options
args.ResponseMessage.AddOption(DhcpOption.DhcpMessageType, (Byte)MessageType.Ack);
this.SetClientOptions(args);
byte[] paramList = args.RequestOptions.ParameterList;
if (paramList != null)
{
args.ResponseMessage.OptionOrdering = paramList;
}
Logger.WriteInfo(this, "ACK (Acknowledge) for message id " + args.RequestMessage.SessionId.ToHexString("0x") + " sent on thread(#" + Thread.CurrentThread.ManagedThreadId + ")");
this.SendReply(args);
}
/// <summary>
/// Remote client connects and makes a request.
/// </summary>
private void OnClientConnect(object sender, ClientConnectedEventArgs args)
{
SocketBuffer channelBuffer = args.ChannelBuffer;
if (channelBuffer != null &&
args.Channel.IsConnected &&
channelBuffer.BytesTransferred >= Constants.DHCP_MIN_MESSAGE_SIZE &&
channelBuffer.BytesTransferred <= Constants.DHCP_MAX_MESSAGE_SIZE)
{
Logger.WriteDebug(this, "PACKET request with channel id " +
args.Channel.ChannelId.ToString() +
" was received from " +
args.Channel.RemoteEndpoint.ToString() +
" and queued for processing...");
DhcpMessageEventArgs messageArgs = new DhcpMessageEventArgs(args.Channel, args.ChannelBuffer);
OnDhcpMessageReceived(this, messageArgs);
ThreadPool.QueueUserWorkItem(new WaitCallback(ProcessRequest), messageArgs);
}
}
/// <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 DISCOVERY message type.
/// </summary>
private void DhcpDiscover(DhcpMessageEventArgs args)
{
#region Pre-Processing
// Start pre-process validation
if (!args.RequestMessage.ClientAddress.Equals(InternetAddress.Any))
{
Logger.WriteDebug(this, "Ignoring DISCOVER message: ciAddr field is non-zero: "
+ args.RequestMessage.ClientAddress.ToString());
return; // if processing not should continue
}
if (args.RequestOptions.ServerIdentifier != null)
{
Logger.WriteDebug(this, "Ignoring DISCOVER message: ServerId option is not null");
return; // if processing should not continue
}
// End pre-Process validation
#endregion Pre-Processing
if (args.ResponseBinding.Address.Equals(InternetAddress.Any) && args.RequestOptions.AddressRequest != null)
{
args.ResponseBinding.Address = new InternetAddress(args.RequestOptions.AddressRequest);
}
BindingLease offer = _bindmgr.GetOffer(args.ResponseBinding);
if (offer == null)
{
Logger.WriteDebug(this, "DISCOVER message: "
+ "No binding available for client");
}
else
{
this.SendOffer(args, offer);
}
}
/// <summary>
/// Set client response lease options.
/// </summary>
private void SetClientOptions(DhcpMessageEventArgs args)
{
// set client response options
args.ResponseMessage.AddOption(DhcpOption.SubnetMask, this._subnet.ToArray());
args.ResponseMessage.AddOption(DhcpOption.Router, this._gateway.ToArray());
if (!StringUtility.IsNullOrEmpty(this._dnsSuffix))
{
args.ResponseMessage.AddOption(DhcpOption.DomainNameSuffix, Encoding.UTF8.GetBytes(this._dnsSuffix));
}
if (this._dnsServers != null && this._dnsServers.Count > 0)
{
byte[] dnsServerAddresses = new byte[this._dnsServers.Count * 4];
for (Int32 i = 0; i < this._dnsServers.Count; i++)
{
InternetAddress ipAddressValue = (InternetAddress)this._dnsServers[i];
ipAddressValue.ToArray().CopyTo(dnsServerAddresses, i * 4);
}
args.ResponseMessage.AddOption(DhcpOption.DomainNameServer, dnsServerAddresses);
}
// set custom response options
if (this._options != null && this._options.Count > 0)
{
foreach (DictionaryEntry option in _options)
{
args.ResponseMessage.AddOption((DhcpOption)option.Key, (byte[])option.Value);
}
}
}
/// <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 RELEASE message type.
/// </summary>
private void DhcpRelease(DhcpMessageEventArgs args)
{
#region Pre-Processing
// Start pre-process validation
if (args.RequestMessage.ClientAddress.Equals(InternetAddress.Any))
{
Logger.WriteDebug(this, "Ignoring RELEASE message: "
+ "ciAddr is zero");
return; // if processing should not continue
}
// End pre-Process validation
#endregion Pre-Processing
BindingLease lease = _bindmgr.SetReleased(args.ResponseBinding);
// no reply for v4 release
if (lease == null)
{
Logger.WriteDebug(this, "RELEASE message: "
+ "No binding available for client to release");
}
else
{
this.OnLeaseReleased(this, new DhcpLeaseEventArgs(lease.Address, lease));
}
}
/// <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 DECLINE message type.
/// </summary>
private void DhcpDecline(DhcpMessageEventArgs args)
{
#region Pre-Processing
// Start pre-process validation
if (args.RequestOptions.AddressRequest == null)
{
Logger.WriteDebug(this, "Ignoring DECLINE message: "
+ "Requested IP option is null");
return; // if processin should not continue
}
// End pre-Process validation
#endregion Pre-Processing
if (args.RequestOptions.AddressRequest != null)
{
args.ResponseBinding.Address = new InternetAddress(args.RequestOptions.AddressRequest);
}
BindingLease lease = _bindmgr.SetDeclined(args.ResponseBinding);
// no reply for v4 decline
if (lease == null)
{
Logger.WriteDebug(this, "DECLINE message: "
+ "No binding available for client to decline");
}
else
{
this.OnLeaseDeclined(this, new DhcpLeaseEventArgs(lease.Address, lease));
}
}
/// <summary>
/// Send OFFER message back to remote client.
/// </summary>
private void SendOffer(DhcpMessageEventArgs args, BindingLease offer)
{
// set header
args.ResponseMessage.AssignedAddress = offer.Address;
args.ResponseMessage.NextServerAddress = args.ResponseMessage.NextServerAddress;
args.ResponseMessage.AddOption(DhcpOption.DhcpMessageType, (Byte)MessageType.Offer);
this.SetLeaseOptions(args);
this.SetClientOptions(args);
byte[] paramList = args.RequestOptions.ParameterList;
if (paramList != null)
{
args.ResponseMessage.OptionOrdering = paramList;
}
Logger.WriteInfo(this, "OFFER for message id " + args.RequestMessage.SessionId.ToHexString("0x") + " sent on thread(#" + Thread.CurrentThread.ManagedThreadId + ")");
this.SendReply(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>
/// Send ACK message back to remote client.
/// </summary>
private void SendAck(DhcpMessageEventArgs args, BindingLease lease)
{
// set header
args.ResponseMessage.AssignedAddress = lease.Address;
// set lease options
this.SetLeaseOptions(args);
this.SendAck(args);
}
/// <summary>
/// Process DISCOVERY message type.
/// </summary>
private void DhcpDiscover(DhcpMessageEventArgs args)
{
#region Pre-Processing
// Start pre-process validation
if (!args.RequestMessage.ClientAddress.Equals(InternetAddress.Any))
{
Logger.WriteDebug(this, "Ignoring DISCOVER message: ciAddr field is non-zero: "
+ args.RequestMessage.ClientAddress.ToString());
return; // if processing not should continue
}
if (args.RequestOptions.ServerIdentifier != null)
{
Logger.WriteDebug(this, "Ignoring DISCOVER message: ServerId option is not null");
return; // if processing should not continue
}
// End pre-Process validation
#endregion Pre-Processing
if (args.ResponseBinding.Address.Equals(InternetAddress.Any) && args.RequestOptions.AddressRequest != null)
{
args.ResponseBinding.Address = new InternetAddress(args.RequestOptions.AddressRequest);
}
BindingLease offer = _bindmgr.GetOffer(args.ResponseBinding);
if (offer == null)
{
Logger.WriteDebug(this, "DISCOVER message: "
+ "No binding available for client");
}
else
{
this.SendOffer(args, offer);
}
}
/// <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>
/// Set global lease options.
/// </summary>
private void SetLeaseOptions(DhcpMessageEventArgs args)
{
args.ResponseMessage.AddOption(DhcpOption.AddressTime, ByteUtility.ReverseByteOrder(BitConverter.GetBytes(this.LeaseDuration)));
args.ResponseMessage.AddOption(DhcpOption.Renewal, ByteUtility.ReverseByteOrder(BitConverter.GetBytes(this.LeaseRenewal)));
args.ResponseMessage.AddOption(DhcpOption.Rebinding, ByteUtility.ReverseByteOrder(BitConverter.GetBytes(this.LeaseRebinding)));
}
/// <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>
/// Send NAK message back to remote client.
/// </summary>
private void SendNak(DhcpMessageEventArgs args)
{
// Set options
args.ResponseMessage.AddOption(DhcpOption.DhcpMessageType, (Byte)MessageType.Nak);
Logger.WriteInfo(this, "NAK (Negative Acknowledge) for message id " + args.RequestMessage.SessionId.ToHexString("0x") + " sent on thread(#" +
Thread.CurrentThread.ManagedThreadId + ")" + " with option message: " + ByteUtility.GetSafeString(args.ResponseMessage.GetOptionData(DhcpOption.DhcpMessage)));
this.SendReply(args);
}
/// <summary>
/// Send ACK message back to remote client.
/// </summary>
private void SendAck(DhcpMessageEventArgs args)
{
// set header
args.ResponseMessage.ClientAddress = args.RequestMessage.ClientAddress;
args.ResponseMessage.NextServerAddress = args.RequestMessage.NextServerAddress;
// set client options
args.ResponseMessage.AddOption(DhcpOption.DhcpMessageType, (Byte)MessageType.Ack);
this.SetClientOptions(args);
byte[] paramList = args.RequestOptions.ParameterList;
if (paramList != null)
{
args.ResponseMessage.OptionOrdering = paramList;
}
Logger.WriteInfo(this, "ACK (Acknowledge) for message id " + args.RequestMessage.SessionId.ToHexString("0x") + " sent on thread(#" + Thread.CurrentThread.ManagedThreadId + ")");
this.SendReply(args);
}
/// <summary>
/// Set global lease options.
/// </summary>
private void SetLeaseOptions(DhcpMessageEventArgs args)
{
args.ResponseMessage.AddOption(DhcpOption.AddressTime, ByteUtility.ReverseByteOrder(BitConverter.GetBytes(this.LeaseDuration)));
args.ResponseMessage.AddOption(DhcpOption.Renewal, ByteUtility.ReverseByteOrder(BitConverter.GetBytes(this.LeaseRenewal)));
args.ResponseMessage.AddOption(DhcpOption.Rebinding, ByteUtility.ReverseByteOrder(BitConverter.GetBytes(this.LeaseRebinding)));
}
/// <summary>
/// Process boot REQUEST and send reply back to remote client.
/// </summary>
private void ProcessRequest(Object state)
{
DhcpMessageEventArgs args = (DhcpMessageEventArgs)state;
args.ResponseMessage = new DhcpMessage();
if (args.RequestMessage.Operation == OperationCode.BootRequest)
{
Byte[] messageTypeData = args.RequestOptions.MessageType;
if (messageTypeData != null && messageTypeData.Length == 1)
{
MessageType messageType = (MessageType)messageTypeData[0];
string requestId = args.RequestMessage.SessionId.ToHexString("0x");
string requestMac = args.RequestMessage.ClientHardwareAddress.ToString();
// classify the client mesage type
switch (messageType)
{
case MessageType.Discover:
Logger.WriteInfo(this, "DISCOVER for message id " + requestId + " from client " + requestMac + " processed on thread #" + Thread.CurrentThread.ManagedThreadId);
this.DhcpDiscover(args);
break;
case MessageType.Request:
Logger.WriteInfo(this, "REQUEST for message id " + requestId + " from client " + requestMac + " processed on thread #" + Thread.CurrentThread.ManagedThreadId);
this.DhcpRequest(args);
break;
case MessageType.Decline:
Logger.WriteInfo(this, "DECLINE for message id " + requestId + " from client " + requestMac + " processed on thread #" + Thread.CurrentThread.ManagedThreadId);
this.DhcpDecline(args);
break;
case MessageType.Release:
Logger.WriteInfo(this, "RELEASE for message id " + requestId + " from client " + requestMac + " processed on thread #" + Thread.CurrentThread.ManagedThreadId);
this.DhcpRelease(args);
break;
case MessageType.Inform:
Logger.WriteInfo(this, "INFORM for message id " + requestId + " from client " + requestMac + " processed on thread #" + Thread.CurrentThread.ManagedThreadId);
this.DhcpInform(args);
break;
case MessageType.Nak:
case MessageType.Ack:
case MessageType.Offer:
break;
default:
Logger.WriteInfo(this, "UNKNOWN message (" + messageType.ToString() + ") received and ignored");
break;
}
}
else
{
Logger.WriteDebug(this, "UNKNOWN message received and ignored");
}
}
}
static void DhcpService_OnDhcpMessageSent(object sender, DhcpMessageEventArgs args)
{
Debug.Print("Emulator: DHCP Message Sent " + args.RequestMessage.ToString());
}
/// <summary>
/// Remote client connects and makes a request.
/// </summary>
private void OnClientConnect(object sender, ClientConnectedEventArgs args)
{
SocketBuffer channelBuffer = args.ChannelBuffer;
if (channelBuffer != null
&& args.Channel.IsConnected
&& channelBuffer.BytesTransferred >= Constants.DHCP_MIN_MESSAGE_SIZE
&& channelBuffer.BytesTransferred <= Constants.DHCP_MAX_MESSAGE_SIZE)
{
Logger.WriteDebug(this, "PACKET request with channel id " +
args.Channel.ChannelId.ToString() +
" was received from " +
args.Channel.RemoteEndpoint.ToString() +
" and queued for processing...");
DhcpMessageEventArgs messageArgs = new DhcpMessageEventArgs(args.Channel, args.ChannelBuffer);
OnDhcpMessageReceived(this, messageArgs);
ThreadPool.QueueUserWorkItem(new WaitCallback(ProcessRequest), messageArgs);
}
}
