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();
}
}
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);
}
}
public void AppendRemoteIceCandidate(IceCandidate remoteIceCandidate)
{
IPAddress candidateIPAddress = null;
//foreach (var iceCandidate in remoteIceCandidates)
//{
// logger.Debug("Appending remote ICE candidate " + iceCandidate.NetworkAddress + ":" + iceCandidate.Port + ".");
//}
if (remoteIceCandidate.Transport.ToLower() != "udp")
{
logger.Debug("Omitting remote non-UDP ICE candidate. " + remoteIceCandidate.RawString + ".");
}
else if (!IPAddress.TryParse(remoteIceCandidate.NetworkAddress, out candidateIPAddress))
{
logger.Debug("Omitting ICE candidate with unrecognised IP Address. " + remoteIceCandidate.RawString + ".");
}
else if (candidateIPAddress.AddressFamily == AddressFamily.InterNetworkV6)
{
logger.Debug("Omitting IPv6 ICE candidate. " + remoteIceCandidate.RawString + ".");
}
else
{
// ToDo: Add srflx and relay endpoints as hosts as well.
if (!_remoteIceCandidates.Any(x => x.NetworkAddress == remoteIceCandidate.NetworkAddress && x.Port == remoteIceCandidate.Port))
{
logger.Debug("Adding remote ICE candidate: " + remoteIceCandidate.CandidateType + " " + remoteIceCandidate.NetworkAddress + ":" + remoteIceCandidate.Port + " (" + remoteIceCandidate.RawString + ").");
_remoteIceCandidates.Add(remoteIceCandidate);
}
}
}
private void GetIceCandidates(ManualResetEvent iceGatheringCompleteMRE)
{
IceNegotiationStartedAt = DateTime.Now;
LocalIceCandidates = new List <IceCandidate>();
var addresses = System.Net.NetworkInformation.IPGlobalProperties.GetIPGlobalProperties().GetUnicastAddresses()
.Where(x =>
x.Address.AddressFamily == AddressFamily.InterNetwork && // Exclude IPv6 at this stage.
IPAddress.IsLoopback(x.Address) == false &&
(x.Address != null && x.Address.ToString().StartsWith(AUTOMATIC_PRIVATE_ADRRESS_PREFIX) == false));
foreach (var address in addresses)
{
logger.Debug("Attempting to create RTP socket with IP address " + address.Address + ".");
Socket rtpSocket = null;
Socket controlSocket = null;
NetServices.CreateRtpSocket(address.Address, WEBRTC_START_PORT, WEBRTC_END_PORT, false, out rtpSocket, out controlSocket);
if (rtpSocket != null)
{
logger.Debug("RTP socket successfully created on " + rtpSocket.LocalEndPoint + ".");
var iceCandidate = new IceCandidate()
{
LocalAddress = address.Address,
Port = ((IPEndPoint)rtpSocket.LocalEndPoint).Port,
LocalRtpSocket = rtpSocket,
LocalControlSocket = controlSocket,
TurnServer = (_turnServerEndPoint != null) ? new TurnServer()
{
ServerEndPoint = _turnServerEndPoint
} : null
};
LocalIceCandidates.Add(iceCandidate);
var listenerTask = Task.Run(() => { StartWebRtcRtpListener(iceCandidate); });
iceCandidate.RtpListenerTask = listenerTask;
if (_turnServerEndPoint != null)
{
var stunBindingTask = Task.Run(() => { SendInitialStunBindingRequest(iceCandidate, iceGatheringCompleteMRE); });
}
else
{
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 IceCandidate Parse(string candidateLine)
{
IceCandidate candidate = new IceCandidate();
candidate.RawString = candidateLine;
string[] candidateFields = candidateLine.Trim().Split(' ');
candidate.Transport = candidateFields[2];
candidate.NetworkAddress = candidateFields[4];
candidate.Port = Convert.ToInt32(candidateFields[5]);
Enum.TryParse <IceCandidateTypesEnum>(candidateFields[7], out candidate.CandidateType);
if (candidateFields.Length > 8 && candidateFields[8] == REMOTE_ADDRESS_KEY)
{
candidate.RemoteAddress = candidateFields[9];
}
if (candidateFields.Length > 10 && candidateFields[10] == REMOTE_PORT_KEY)
{
candidate.RemotePort = Convert.ToInt32(candidateFields[11]);
}
return(candidate);
}
public static SDP ParseSDPDescription(string sdpDescription)
{
try
{
if (sdpDescription != null && sdpDescription.Trim().Length > 0)
{
SDP sdp = new SDP();
SDPMediaAnnouncement activeAnnouncement = null;
string[] sdpLines = Regex.Split(sdpDescription, CRLF);
foreach (string sdpLine in sdpLines)
{
if (sdpLine.Trim().StartsWith("v="))
{
if (!Decimal.TryParse(sdpLine.Substring(2), out sdp.Version))
{
logger.Warn("The Version value in an SDP description could not be parsed as a decimal: " + sdpLine + ".");
}
}
else if (sdpLine.Trim().StartsWith("o="))
{
string[] ownerFields = sdpLine.Substring(2).Split(' ');
sdp.Username = ownerFields[0];
sdp.SessionId = ownerFields[1];
Int32.TryParse(ownerFields[2], out sdp.AnnouncementVersion);
sdp.NetworkType = ownerFields[3];
sdp.AddressType = ownerFields[4];
sdp.Address = ownerFields[5];
}
else if (sdpLine.Trim().StartsWith("s="))
{
sdp.SessionName = sdpLine.Substring(2);
}
else if (sdpLine.Trim().StartsWith("c="))
{
if (activeAnnouncement != null)
{
activeAnnouncement.Connection = SDPConnectionInformation.ParseConnectionInformation(sdpLine);
}
else
{
sdp.Connection = SDPConnectionInformation.ParseConnectionInformation(sdpLine);
}
}
else if (sdpLine.Trim().StartsWith("b="))
{
if (activeAnnouncement != null)
{
activeAnnouncement.BandwidthAttributes.Add(sdpLine.Substring(2));
}
else
{
sdp.BandwidthAttributes.Add(sdpLine.Substring(2));
}
}
else if (sdpLine.Trim().StartsWith("t="))
{
sdp.Timing = sdpLine.Substring(2);
}
else if (sdpLine.Trim().StartsWith("m="))
{
Match mediaMatch = Regex.Match(sdpLine.Substring(2).Trim(), @"(?<type>\w+)\s+(?<port>\d+)\s+(?<transport>\S+)\s+(?<formats>.*)$");
if (mediaMatch.Success)
{
SDPMediaAnnouncement announcement = new SDPMediaAnnouncement();
announcement.Media = SDPMediaTypes.GetSDPMediaType(mediaMatch.Result("${type}"));
Int32.TryParse(mediaMatch.Result("${port}"), out announcement.Port);
announcement.Transport = mediaMatch.Result("${transport}");
announcement.ParseMediaFormats(mediaMatch.Result("${formats}"));
sdp.Media.Add(announcement);
activeAnnouncement = announcement;
}
else
{
logger.Warn("A media line in SDP was invalid: " + sdpLine.Substring(2) + ".");
}
}
else if (sdpLine.Trim().StartsWith("a=" + ICE_UFRAG_ATTRIBUTE_PREFIX))
{
sdp.IceUfrag = sdpLine.Substring(sdpLine.IndexOf(':') + 1);
}
else if (sdpLine.Trim().StartsWith("a=" + ICE_PWD_ATTRIBUTE_PREFIX))
{
sdp.IcePwd = sdpLine.Substring(sdpLine.IndexOf(':') + 1);
}
else if (sdpLine.Trim().StartsWith(SDPMediaAnnouncement.MEDIA_FORMAT_ATTRIBUE_PREFIX))
{
if (activeAnnouncement != null)
{
Match formatAttributeMatch = Regex.Match(sdpLine.Trim(), SDPMediaAnnouncement.MEDIA_FORMAT_ATTRIBUE_PREFIX + @"(?<id>\d+)\s+(?<attribute>.*)$");
if (formatAttributeMatch.Success)
{
int formatID;
if (Int32.TryParse(formatAttributeMatch.Result("${id}"), out formatID))
{
activeAnnouncement.AddFormatAttribute(formatID, formatAttributeMatch.Result("${attribute}"));
}
else
{
logger.Warn("Invalid media format attribute in SDP: " + sdpLine);
}
}
else
{
activeAnnouncement.AddExtra(sdpLine);
}
}
else
{
logger.Warn("There was no active media announcement for a media format attribute, ignoring.");
}
}
else if (sdpLine.Trim().StartsWith(SDPMediaAnnouncement.MEDIA_FORMAT_PARAMETERS_ATTRIBUE_PREFIX))
{
if (activeAnnouncement != null)
{
Match formatAttributeMatch = Regex.Match(sdpLine.Trim(), SDPMediaAnnouncement.MEDIA_FORMAT_PARAMETERS_ATTRIBUE_PREFIX + @"(?<id>\d+)\s+(?<attribute>.*)$");
if (formatAttributeMatch.Success)
{
int formatID;
if (Int32.TryParse(formatAttributeMatch.Result("${id}"), out formatID))
{
activeAnnouncement.AddFormatParameterAttribute(formatID, formatAttributeMatch.Result("${attribute}"));
}
else
{
logger.Warn("Invalid media format parameter attribute in SDP: " + sdpLine);
}
}
else
{
activeAnnouncement.AddExtra(sdpLine);
}
}
else
{
logger.Warn("There was no active media announcement for a media format parameter attribute, ignoring.");
}
}
else if (sdpLine.Trim().StartsWith("a=" + ICE_CANDIDATE_ATTRIBUTE_PREFIX))
{
if (sdp.IceCandidates == null)
{
sdp.IceCandidates = new List <IceCandidate>();
}
sdp.IceCandidates.Add(IceCandidate.Parse(sdpLine.Substring(sdpLine.IndexOf(':') + 1)));
}
else
{
if (activeAnnouncement != null)
{
activeAnnouncement.AddExtra(sdpLine);
}
else
{
sdp.AddExtra(sdpLine);
}
}
}
return(sdp);
}
else
{
return(null);
}
}
catch (Exception excp)
{
logger.Error("Exception ParseSDPDescription. " + excp.Message);
throw excp;
}
}
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);
}
}