/// <summary>
/// Receive and process message
/// </summary>
protected virtual void OnReceiveMessage(object client)
{
TcpClient tcpClient = client as TcpClient;
NetworkStream stream = tcpClient.GetStream();
try
{
// Now read to a string
DateTime lastReceive = DateTime.Now;
while (DateTime.Now.Subtract(lastReceive) < this.m_timeout)
{
if (!stream.DataAvailable)
{
Thread.Sleep(10);
continue;
}
// Read LLP head byte
int llpByte = stream.ReadByte();
if (llpByte != START_TX) // first byte must be HT
{
throw new InvalidOperationException("Invalid LLP First Byte");
}
// Standard stream stuff, read until the stream is exhausted
StringBuilder messageData = new StringBuilder();
byte[] buffer = new byte[1024];
bool receivedEOF = false, scanForCr = false;
while (!receivedEOF)
{
if (DateTime.Now.Subtract(lastReceive) > this.m_timeout)
{
throw new TimeoutException("Data not received in the specified amount of time. Increase the timeout or check the network connection");
}
if (!stream.DataAvailable)
{
Thread.Sleep(10);
continue;
}
int br = stream.Read(buffer, 0, 1024);
messageData.Append(System.Text.Encoding.UTF8.GetString(buffer, 0, br));
// Need to check for CR?
if (scanForCr)
{
receivedEOF = buffer[0] == END_TXNL;
}
else
{
// Look for FS
int fsPos = Array.IndexOf(buffer, (byte)END_TX);
if (fsPos == -1) // not found
{
continue;
}
else if (fsPos < buffer.Length - 1) // more room to read
{
receivedEOF = buffer[fsPos + 1] == END_TXNL;
}
else
{
scanForCr = true; // Cannot check the end of message for CR because there is no more room in the message buffer
}
// so need to check on the next loop
}
}
// Use the nHAPI parser to process the data
Hl7MessageReceivedEventArgs messageArgs = null;
String originalVersion = null;
try
{
// Setup local and remote receive endpoint data for auditing
var localEp = tcpClient.Client.LocalEndPoint as IPEndPoint;
var remoteEp = tcpClient.Client.RemoteEndPoint as IPEndPoint;
Uri localEndpoint = new Uri(String.Format("llp://{0}:{1}", localEp.Address, localEp.Port));
Uri remoteEndpoint = new Uri(String.Format("llp://{0}:{1}", remoteEp.Address, remoteEp.Port));
#if DEBUG
this.m_traceSource.TraceInfo("Received message from llp://{0}:{1} : {2}", remoteEp.Address, remoteEp.Port, messageData);
#endif
// HACK: nHAPI doesn't like URLs ... Will fix this later
string messageString = messageData.ToString().Replace("|URL|", "|ST|");
var message = MessageUtils.ParseMessage(messageString, out originalVersion);
messageArgs = new Hl7MessageReceivedEventArgs(message, localEndpoint, remoteEndpoint, DateTime.Now);
HL7OperationContext.Current = new HL7OperationContext(messageArgs);
// Call any bound event handlers that there is a message available
OnMessageReceived(messageArgs);
}
finally
{
// Send the response back
using (MemoryStream memoryWriter = new MemoryStream())
{
using (StreamWriter streamWriter = new StreamWriter(memoryWriter))
{
memoryWriter.Write(new byte[] { START_TX }, 0, 1); // header
if (messageArgs != null && messageArgs.Response != null)
{
var strMessage = MessageUtils.EncodeMessage(messageArgs.Response, originalVersion);
#if DEBUG
this.m_traceSource.TraceInfo("Sending message to llp://{0} : {1}", tcpClient.Client.RemoteEndPoint, strMessage);
#endif
// Since nHAPI only emits a string we just send that along the stream
streamWriter.Write(strMessage);
streamWriter.Flush();
}
memoryWriter.Write(new byte[] { END_TX, END_TXNL }, 0, 2); // Finish the stream with FSCR
stream.Write(memoryWriter.ToArray(), 0, (int)memoryWriter.Position);
stream.Flush();
}
}
lastReceive = DateTime.Now; // Update the last receive time so the timeout function works
}
}
}
catch (Exception e)
{
this.m_traceSource.TraceEvent(EventLevel.Error, e.ToString());
}
finally
{
stream.Close();
tcpClient.Close();
HL7OperationContext.Current = null;
}
}
/// <summary>
/// Send a message and receive the message
/// </summary>
public IMessage SendAndReceive(IMessage message)
{
// Encode the message
var strMessage = MessageUtils.EncodeMessage(message, (message.GetStructure("MSH") as NHapi.Model.V25.Segment.MSH).VersionID.VersionID.Value);
#if DEBUG
this.tracer.TraceEvent(EventLevel.Informational, strMessage);
#endif
// Open a TCP port
using (var client = new TcpClient(AddressFamily.InterNetwork))
{
try
{
// Connect on the socket
client.Connect(this.endpoint.Host, this.endpoint.Port);
// Get the stream
using (var stream = client.GetStream())
{
Stream realStream = stream;
if (this.clientCertificate != null)
{
realStream = new SslStream(stream, false, this.RemoteCertificateValidation);
var collection = new X509CertificateCollection
{
this.clientCertificate
};
((SslStream)realStream).AuthenticateAsClient(this.endpoint.ToString(), collection, System.Security.Authentication.SslProtocols.Tls, true);
}
// Write message in ASCII encoding
byte[] buffer = Encoding.UTF8.GetBytes(strMessage);
byte[] sendBuffer = new byte[buffer.Length + 3];
sendBuffer[0] = 0x0b;
Array.Copy(buffer, 0, sendBuffer, 1, buffer.Length);
Array.Copy(new byte[] { 0x1c, 0x0d }, 0, sendBuffer, sendBuffer.Length - 2, 2);
stream.Write(sendBuffer, 0, sendBuffer.Length);
// Write end message
stream.Flush(); // Ensure all bytes get sent down the wire
// Now read the response
StringBuilder response = new StringBuilder();
buffer = new byte[1024];
while (!buffer.Contains((byte)0x1c)) // HACK: Keep reading until the buffer has the FS character
{
int br = stream.Read(buffer, 0, 1024);
int ofs = 0;
if (buffer[ofs] == '\v')
{
ofs = 1;
br = br - 1;
}
response.Append(Encoding.UTF8.GetString(buffer, ofs, br));
}
#if DEBUG
this.tracer.TraceEvent(EventLevel.Informational, response.ToString());
#endif
String version = null;
return(MessageUtils.ParseMessage(response.ToString(), out version));
}
}
catch (Exception e)
{
#if DEBUG
this.tracer.TraceEvent(EventLevel.Error, e.StackTrace);
#endif
this.tracer.TraceEvent(EventLevel.Error, e.Message);
throw;
}
}
}
/// <summary>
/// Represent message as string
/// </summary>
public static String ToString(IMessage msg)
{
return(MessageUtils.EncodeMessage(msg, "2.5"));
}
/// <summary>
/// Receive and process message
/// </summary>
protected virtual void OnReceiveMessage(object client)
{
using (TcpClient tcpClient = client as TcpClient)
{
this.m_traceSource.TraceEvent(EventLevel.Verbose, "Accepted connection on {0} from {1}", this.m_listener.LocalEndpoint, tcpClient.Client.RemoteEndPoint);
NetworkStream stream = tcpClient.GetStream();
try
{
// Now read to a string
DateTime lastReceive = DateTime.Now;
while (DateTime.Now.Subtract(lastReceive) < this.m_timeout)
{
if (!stream.DataAvailable)
{
Thread.Sleep(10);
continue;
}
// Read LLP head byte
int llpByte = stream.ReadByte();
if (llpByte != START_TX) // first byte must be HT
{
throw new InvalidOperationException("Invalid LLP First Byte");
}
// Standard stream stuff, read until the stream is exhausted
StringBuilder messageData = new StringBuilder();
byte[] buffer = new byte[1024];
bool receivedEOF = false, scanForCr = false;
while (!receivedEOF)
{
if (DateTime.Now.Subtract(lastReceive) > this.m_timeout)
{
throw new TimeoutException("Data not received in the specified amount of time. Increase the timeout or check the network connection");
}
if (!stream.DataAvailable)
{
Thread.Sleep(10);
continue;
}
int br = stream.Read(buffer, 0, 1024);
messageData.Append(System.Text.Encoding.UTF8.GetString(buffer, 0, br));
// Need to check for CR?
if (scanForCr)
{
receivedEOF = buffer[0] == END_TXNL;
}
else
{
// Look for FS
int fsPos = Array.IndexOf(buffer, (byte)END_TX);
if (fsPos == -1) // not found
{
continue;
}
else if (fsPos < buffer.Length - 1) // more room to read
{
receivedEOF = buffer[fsPos + 1] == END_TXNL;
}
else
{
scanForCr = true; // Cannot check the end of message for CR because there is no more room in the message buffer
}
// so need to check on the next loop
}
}
// Use the nHAPI parser to process the data
Hl7MessageReceivedEventArgs messageArgs = null;
String originalVersion = null;
// Setup local and remote receive endpoint data for auditing
var localEp = tcpClient.Client.LocalEndPoint as IPEndPoint;
var remoteEp = tcpClient.Client.RemoteEndPoint as IPEndPoint;
Uri localEndpoint = new Uri(String.Format("llp://{0}:{1}", localEp.Address, localEp.Port));
Uri remoteEndpoint = new Uri(String.Format("llp://{0}:{1}", remoteEp.Address, remoteEp.Port));
foreach (var messagePart in messageData.ToString().Split((char)END_TX))
{
if (messagePart == "\r")
{
continue;
}
try
{
this.m_traceSource.TraceInfo("Received message from llp://{0}:{1} : {2}", remoteEp.Address, remoteEp.Port, messagePart);
// HACK: nHAPI doesn't like URLs ... Will fix this later
string messageString = messagePart.Replace("|URL|", "|ST|");
var message = MessageUtils.ParseMessage(messageString, out originalVersion);
messageArgs = new Hl7MessageReceivedEventArgs(message, localEndpoint, remoteEndpoint, DateTime.Now);
HL7OperationContext.Current = new HL7OperationContext(messageArgs);
// Call any bound event handlers that there is a message available
OnMessageReceived(messageArgs);
}
catch (Exception e)
{
this.m_traceSource.TraceError("Error processing HL7 message: {0}", e);
if (messageArgs != null)
{
var nack = new NHapi.Model.V25.Message.ACK();
nack.MSH.SetDefault(messageArgs.Message.GetStructure("MSH") as NHapi.Model.V25.Segment.MSH);
nack.MSA.AcknowledgmentCode.Value = "AE";
nack.MSA.TextMessage.Value = $"FATAL - {e.Message}";
nack.MSA.MessageControlID.Value = (messageArgs.Message.GetStructure("MSH") as NHapi.Model.V25.Segment.MSH).MessageControlID.Value;
messageArgs.Response = nack;
var icomps = PipeParser.Encode(messageArgs.Message.GetStructure("MSH") as NHapi.Base.Model.ISegment, new EncodingCharacters('|', "^~\\&")).Split('|');
var ocomps = PipeParser.Encode(messageArgs.Response.GetStructure("MSH") as NHapi.Base.Model.ISegment, new EncodingCharacters('|', "^~\\&")).Split('|');
AuditUtil.AuditNetworkRequestFailure(e, messageArgs.ReceiveEndpoint, Enumerable.Range(1, icomps.Length).ToDictionary(o => $"MSH-{o}", o => icomps[o - 1]), Enumerable.Range(1, icomps.Length).ToDictionary(o => $"MSH-{o}", o => ocomps[o - 1]));
}
else
{
AuditUtil.AuditNetworkRequestFailure(e, localEndpoint, new System.Collections.Specialized.NameValueCollection(), new System.Collections.Specialized.NameValueCollection());
}
}
finally
{
// Send the response back
using (MemoryStream memoryWriter = new MemoryStream())
{
using (StreamWriter streamWriter = new StreamWriter(memoryWriter))
{
memoryWriter.Write(new byte[] { START_TX }, 0, 1); // header
if (messageArgs != null && messageArgs.Response != null)
{
var strMessage = MessageUtils.EncodeMessage(messageArgs.Response, originalVersion);
this.m_traceSource.TraceInfo("Sending message to llp://{0} : {1}", tcpClient.Client.RemoteEndPoint, strMessage);
// Since nHAPI only emits a string we just send that along the stream
streamWriter.Write(strMessage);
streamWriter.Flush();
}
memoryWriter.Write(new byte[] { END_TX, END_TXNL }, 0, 2); // Finish the stream with FSCR
stream.Write(memoryWriter.ToArray(), 0, (int)memoryWriter.Position);
stream.Flush();
}
}
lastReceive = DateTime.Now; // Update the last receive time so the timeout function works
}
}
if (!stream.DataAvailable)
{
return;
}
}
}
catch (Exception e)
{
this.m_traceSource.TraceEvent(EventLevel.Error, e.ToString());
}
finally
{
stream.Close();
tcpClient.Close();
HL7OperationContext.Current = null;
}
}
}
