private void CreateTurnPermissions()
{
try
{
var localTurnIceCandidate = (from cand in LocalIceCandidates where cand.TurnRelayIPEndPoint != null select cand).First();
var remoteTurnCandidate = (from cand in RemoteIceCandidates where cand.CandidateType == IceCandidateTypesEnum.relay select cand).First();
// Send create permission request
STUNv2Message turnPermissionRequest = new STUNv2Message(STUNv2MessageTypesEnum.CreatePermission);
turnPermissionRequest.Header.TransactionId = Guid.NewGuid().ToByteArray().Take(12).ToArray();
//turnBindRequest.Attributes.Add(new STUNv2Attribute(STUNv2AttributeTypesEnum.ChannelNumber, (ushort)3000));
turnPermissionRequest.Attributes.Add(new STUNv2XORAddressAttribute(STUNv2AttributeTypesEnum.XORPeerAddress, remoteTurnCandidate.Port, IPAddress.Parse(remoteTurnCandidate.NetworkAddress)));
turnPermissionRequest.Attributes.Add(new STUNv2Attribute(STUNv2AttributeTypesEnum.Username, Encoding.UTF8.GetBytes(localTurnIceCandidate.TurnServer.Username)));
turnPermissionRequest.Attributes.Add(new STUNv2Attribute(STUNv2AttributeTypesEnum.Nonce, Encoding.UTF8.GetBytes(localTurnIceCandidate.TurnServer.Nonce)));
turnPermissionRequest.Attributes.Add(new STUNv2Attribute(STUNv2AttributeTypesEnum.Realm, Encoding.UTF8.GetBytes(localTurnIceCandidate.TurnServer.Realm)));
MD5 md5 = new MD5CryptoServiceProvider();
byte[] hmacKey = md5.ComputeHash(Encoding.UTF8.GetBytes(localTurnIceCandidate.TurnServer.Username + ":" + localTurnIceCandidate.TurnServer.Realm + ":" + localTurnIceCandidate.TurnServer.Password));
byte[] turnPermissionReqBytes = turnPermissionRequest.ToByteBuffer(hmacKey, false);
localTurnIceCandidate.LocalRtpSocket.SendTo(turnPermissionReqBytes, localTurnIceCandidate.TurnServer.ServerEndPoint);
}
catch (Exception excp)
{
logger.Error("Exception CreateTurnPermissions. " + excp);
}
}
private void AllocateTurn(IceCandidate iceCandidate)
{
try
{
if (iceCandidate.TurnAllocateAttempts >= MAXIMUM_TURN_ALLOCATE_ATTEMPTS)
{
logger.Debug("TURN allocation for local socket " + iceCandidate.LocalAddress + " failed after " + iceCandidate.TurnAllocateAttempts + " attempts.");
iceCandidate.IsGatheringComplete = true;
}
else
{
iceCandidate.TurnAllocateAttempts++;
//logger.Debug("Sending STUN connectivity check to client " + client.SocketAddress + ".");
STUNv2Message stunRequest = new STUNv2Message(STUNv2MessageTypesEnum.Allocate);
stunRequest.Header.TransactionId = Guid.NewGuid().ToByteArray().Take(12).ToArray();
stunRequest.Attributes.Add(new STUNv2Attribute(STUNv2AttributeTypesEnum.Lifetime, 3600));
stunRequest.Attributes.Add(new STUNv2Attribute(STUNv2AttributeTypesEnum.RequestedTransport, STUNv2AttributeConstants.UdpTransportType)); // UDP
byte[] stunReqBytes = stunRequest.ToByteBuffer(null, false);
iceCandidate.LocalRtpSocket.SendTo(stunReqBytes, iceCandidate.TurnServer.ServerEndPoint);
}
}
catch (Exception excp)
{
logger.Error("Exception AllocateTurn. " + excp);
}
}
private void SendInitialStunBindingRequest(IceCandidate iceCandidate, ManualResetEvent iceGatheringCompleteMRE)
{
int attempt = 1;
while (attempt < INITIAL_STUN_BINDING_ATTEMPTS_LIMIT && !IsClosed && !iceCandidate.IsGatheringComplete)
{
logger.Debug("Sending STUN binding request " + attempt + " from " + iceCandidate.LocalRtpSocket.LocalEndPoint + " to " + iceCandidate.TurnServer.ServerEndPoint + ".");
STUNv2Message stunRequest = new STUNv2Message(STUNv2MessageTypesEnum.BindingRequest);
stunRequest.Header.TransactionId = Guid.NewGuid().ToByteArray().Take(12).ToArray();
byte[] stunReqBytes = stunRequest.ToByteBuffer(null, false);
iceCandidate.LocalRtpSocket.SendTo(stunReqBytes, iceCandidate.TurnServer.ServerEndPoint);
Thread.Sleep(INITIAL_STUN_BINDING_PERIOD_MILLISECONDS);
attempt++;
}
iceCandidate.IsGatheringComplete = true;
// Potentially save a few seconds if all the ICE candidates are now ready.
if (LocalIceCandidates.All(x => x.IsGatheringComplete))
{
iceGatheringCompleteMRE.Set();
}
}
public static STUNv2Message ParseSTUNMessage(byte[] buffer, int bufferLength)
{
if (buffer != null && buffer.Length > 0 && buffer.Length >= bufferLength)
{
STUNv2Message stunMessage = new STUNv2Message();
stunMessage.Header = STUNv2Header.ParseSTUNHeader(buffer);
if (stunMessage.Header.MessageLength > 0)
{
stunMessage.Attributes = STUNv2Attribute.ParseMessageAttributes(buffer, STUNv2Header.STUN_HEADER_LENGTH, bufferLength);
}
return(stunMessage);
}
return(null);
}
private void ProcessStunMessage(IceCandidate iceCandidate, STUNv2Message stunMessage, IPEndPoint remoteEndPoint)
{
//logger.Debug("STUN message received from remote " + remoteEndPoint + " " + stunMessage.Header.MessageType + ".");
if (stunMessage.Header.MessageType == STUNv2MessageTypesEnum.BindingRequest)
{
STUNv2Message stunResponse = new STUNv2Message(STUNv2MessageTypesEnum.BindingSuccessResponse);
stunResponse.Header.TransactionId = stunMessage.Header.TransactionId;
stunResponse.AddXORMappedAddressAttribute(remoteEndPoint.Address, remoteEndPoint.Port);
// ToDo: Check authentication.
byte[] stunRespBytes = stunResponse.ToByteBufferStringKey(LocalIcePassword, true);
iceCandidate.LocalRtpSocket.SendTo(stunRespBytes, remoteEndPoint);
iceCandidate.LastStunRequestReceivedAt = DateTime.Now;
iceCandidate.IsStunRemoteExchangeComplete = true;
if (_remoteIceCandidates != null && !_remoteIceCandidates.Any(x =>
(x.NetworkAddress == remoteEndPoint.Address.ToString() || x.RemoteAddress == remoteEndPoint.Address.ToString()) &&
(x.Port == remoteEndPoint.Port || x.RemotePort == remoteEndPoint.Port)))
{
// This STUN request has come from a socket not in the remote ICE candidates list. Add it so we can send our STUN binding request to it.
IceCandidate remoteIceCandidate = new IceCandidate()
{
Transport = "udp",
NetworkAddress = remoteEndPoint.Address.ToString(),
Port = remoteEndPoint.Port,
CandidateType = IceCandidateTypesEnum.host
};
logger.Debug("Adding missing remote ICE candidate for " + remoteEndPoint + ".");
_remoteIceCandidates.Add(remoteIceCandidate);
}
}
else if (stunMessage.Header.MessageType == STUNv2MessageTypesEnum.BindingSuccessResponse)
{
if (_turnServerEndPoint != null && remoteEndPoint.ToString() == _turnServerEndPoint.ToString())
{
if (iceCandidate.IsGatheringComplete == false)
{
var reflexAddressAttribute = stunMessage.Attributes.FirstOrDefault(y => y.AttributeType == STUNv2AttributeTypesEnum.XORMappedAddress) as STUNv2XORAddressAttribute;
if (reflexAddressAttribute != null)
{
iceCandidate.StunRflxIPEndPoint = new IPEndPoint(reflexAddressAttribute.Address, reflexAddressAttribute.Port);
iceCandidate.IsGatheringComplete = true;
logger.Debug("ICE gathering complete for local socket " + iceCandidate.LocalRtpSocket.LocalEndPoint + ", rflx address " + iceCandidate.StunRflxIPEndPoint + ".");
}
else
{
iceCandidate.IsGatheringComplete = true;
logger.Debug("The STUN binding response received on " + iceCandidate.LocalRtpSocket.LocalEndPoint + " from " + remoteEndPoint + " did not have an XORMappedAddress attribute, rlfx address can not be determined.");
}
}
}
else
{
iceCandidate.LastStunResponseReceivedAt = DateTime.Now;
if (iceCandidate.IsStunLocalExchangeComplete == false)
{
iceCandidate.IsStunLocalExchangeComplete = true;
logger.Debug("WebRTC client STUN exchange complete for call " + CallID + ", candidate local socket " + iceCandidate.LocalRtpSocket.LocalEndPoint + ", remote socket " + remoteEndPoint + ".");
SetIceConnectionState(IceConnectionStatesEnum.Connected);
}
}
}
else if (stunMessage.Header.MessageType == STUNv2MessageTypesEnum.BindingErrorResponse)
{
logger.Warn("A STUN binding error response was received on " + iceCandidate.LocalRtpSocket.LocalEndPoint + " from " + remoteEndPoint + ".");
}
else
{
logger.Warn("An unrecognised STUN request was received on " + iceCandidate.LocalRtpSocket.LocalEndPoint + " from " + remoteEndPoint + ".");
}
}
private void StartWebRtcRtpListener(IceCandidate iceCandidate)
{
string localEndPoint = "?";
try
{
localEndPoint = iceCandidate.LocalRtpSocket.LocalEndPoint.ToString();
logger.Debug("Starting WebRTC RTP listener for call " + CallID + " on socket " + localEndPoint + ".");
IPEndPoint remoteEndPoint = new IPEndPoint(IPAddress.Any, 0);
UdpClient localSocket = new UdpClient();
localSocket.Client = iceCandidate.LocalRtpSocket;
while (!IsClosed)
{
try
{
//logger.Debug("ListenToReceiverWebRTCClient Receive.");
byte[] buffer = localSocket.Receive(ref remoteEndPoint);
iceCandidate.LastCommunicationAt = DateTime.Now;
//logger.Debug(buffer.Length + " bytes read on Receiver Client media socket from " + remoteEndPoint.ToString() + ".");
//if (buffer.Length > 3 && buffer[0] == 0x16 && buffer[1] == 0xfe)
if (buffer[0] >= 20 && buffer[0] <= 64)
{
//OnMediaPacket(iceCandidate, buffer, remoteEndPoint);
if (OnDtlsPacket != null)
{
OnDtlsPacket(iceCandidate, buffer, remoteEndPoint);
}
}
//else if ((buffer[0] & 0x80) == 0)
else if (buffer[0] == 0 || buffer[0] == 1)
{
STUNv2Message stunMessage = STUNv2Message.ParseSTUNMessage(buffer, buffer.Length);
ProcessStunMessage(iceCandidate, stunMessage, remoteEndPoint);
}
else
{
if (OnMediaPacket != null)
{
OnMediaPacket(iceCandidate, buffer, remoteEndPoint);
}
}
}
catch (Exception sockExcp)
{
_communicationFailureCount++;
logger.Warn("Exception ListenToReceiverWebRTCClient Receive (" + localEndPoint + " and " + remoteEndPoint + ", failure count " + _communicationFailureCount + "). " + sockExcp.Message);
// Need to be careful about deciding when the connection has failed. Sometimes the STUN requests we send will arrive before the remote peer is ready and cause a socket exception.
// Only shutdown the peer if we are sure all ICE intialisation is complete and the socket exception occurred after the RTP had stated flowing.
if (iceCandidate.IsStunLocalExchangeComplete && iceCandidate.IsStunRemoteExchangeComplete &&
iceCandidate.RemoteRtpEndPoint != null && remoteEndPoint != null && iceCandidate.RemoteRtpEndPoint.ToString() == remoteEndPoint.ToString() &&
DateTime.Now.Subtract(IceNegotiationStartedAt).TotalSeconds > 10)
{
logger.Warn("WebRtc peer communication failure on call " + CallID + " for local RTP socket " + localEndPoint + " and remote RTP socket " + remoteEndPoint + " .");
iceCandidate.DisconnectionMessage = sockExcp.Message;
break;
}
else if (_communicationFailureCount > COMMUNICATION_FAILURE_COUNT_FOR_CLOSE)
{
logger.Warn("WebRtc peer communication failures on call " + CallID + " exceeded limit of " + COMMUNICATION_FAILURE_COUNT_FOR_CLOSE + " closing peer.");
break;
}
//else if (DateTime.Now.Subtract(peer.IceNegotiationStartedAt).TotalSeconds > ICE_CONNECTION_LIMIT_SECONDS)
//{
// logger.Warn("WebRTC peer ICE connection establishment timed out on call " + peer.CallID + " for " + iceCandidate.LocalRtpSocket.LocalEndPoint + ".");
// break;
//}
}
}
Close();
}
catch (Exception excp)
{
logger.Error("Exception ListenForWebRTCClient (" + localEndPoint + "). " + excp);
}
}
private void SendStunConnectivityChecks()
{
try
{
while (!IsClosed)
{
try
{
// If one of the ICE candidates has the remote RTP socket set then the negotiation is complete and the STUN checks are to keep the connection alive.
if (LocalIceCandidates.Any(x => x.IsConnected == true))
{
var iceCandidate = LocalIceCandidates.First(x => x.IsConnected == true);
// Remote RTP endpoint gets set when the DTLS negotiation is finished.
if (iceCandidate.RemoteRtpEndPoint != null)
{
//logger.Debug("Sending STUN connectivity check to client " + iceCandidate.RemoteRtpEndPoint + ".");
STUNv2Message stunRequest = new STUNv2Message(STUNv2MessageTypesEnum.BindingRequest);
stunRequest.Header.TransactionId = Guid.NewGuid().ToByteArray().Take(12).ToArray();
stunRequest.AddUsernameAttribute(RemoteIceUser + ":" + LocalIceUser);
stunRequest.Attributes.Add(new STUNv2Attribute(STUNv2AttributeTypesEnum.Priority, new byte[] { 0x6e, 0x7f, 0x1e, 0xff }));
stunRequest.Attributes.Add(new STUNv2Attribute(STUNv2AttributeTypesEnum.UseCandidate, null)); // Must send this to get DTLS started.
byte[] stunReqBytes = stunRequest.ToByteBufferStringKey(RemoteIcePassword, true);
iceCandidate.LocalRtpSocket.SendTo(stunReqBytes, iceCandidate.RemoteRtpEndPoint);
iceCandidate.LastSTUNSendAt = DateTime.Now;
}
var secondsSinceLastResponse = DateTime.Now.Subtract(iceCandidate.LastCommunicationAt).TotalSeconds;
if (secondsSinceLastResponse > ICE_TIMEOUT_SECONDS)
{
logger.Warn("No STUN response was received on a connected ICE connection for " + secondsSinceLastResponse + "s, closing connection.");
iceCandidate.IsDisconnected = true;
if (LocalIceCandidates.Any(x => x.IsConnected == true) == false)
{
// If there are no connected local candidates left close the peer.
Close();
break;
}
}
}
else
{
if (_remoteIceCandidates.Count() > 0)
{
foreach (var localIceCandidate in LocalIceCandidates.Where(x => x.IsStunLocalExchangeComplete == false && x.StunConnectionRequestAttempts < MAXIMUM_STUN_CONNECTION_ATTEMPTS))
{
localIceCandidate.StunConnectionRequestAttempts++;
// ToDo: Include srflx and relay addresses.
foreach (var remoteIceCandidate in RemoteIceCandidates.Where(x => x.Transport != "tcp" && x.NetworkAddress.NotNullOrBlank())) // Only supporting UDP candidates at this stage.
{
IPAddress remoteAddress = IPAddress.Parse(remoteIceCandidate.NetworkAddress);
logger.Debug("Sending authenticated STUN binding request " + localIceCandidate.StunConnectionRequestAttempts + " from " + localIceCandidate.LocalRtpSocket.LocalEndPoint + " to WebRTC peer at " + remoteIceCandidate.NetworkAddress + ":" + remoteIceCandidate.Port + ".");
STUNv2Message stunRequest = new STUNv2Message(STUNv2MessageTypesEnum.BindingRequest);
stunRequest.Header.TransactionId = Guid.NewGuid().ToByteArray().Take(12).ToArray();
stunRequest.AddUsernameAttribute(RemoteIceUser + ":" + LocalIceUser);
stunRequest.Attributes.Add(new STUNv2Attribute(STUNv2AttributeTypesEnum.Priority, new byte[] { 0x6e, 0x7f, 0x1e, 0xff }));
stunRequest.Attributes.Add(new STUNv2Attribute(STUNv2AttributeTypesEnum.UseCandidate, null)); // Must send this to get DTLS started.
byte[] stunReqBytes = stunRequest.ToByteBufferStringKey(RemoteIcePassword, true);
localIceCandidate.LocalRtpSocket.SendTo(stunReqBytes, new IPEndPoint(IPAddress.Parse(remoteIceCandidate.NetworkAddress), remoteIceCandidate.Port));
localIceCandidate.LastSTUNSendAt = DateTime.Now;
}
}
}
}
}
catch (Exception excp)
{
logger.Error("Exception SendStunConnectivityCheck ConnectivityCheck. " + excp);
}
if (!IsClosed)
{
Thread.Sleep(ESTABLISHED_STUN_BINDING_PERIOD_MILLISECONDS);
}
}
}
catch (Exception excp)
{
logger.Error("Exception SendStunConnectivityCheck. " + excp);
}
}
