How do I call a WCF method from c++ using Named pipes? - c++

Question

UPDATE:
Looking through the protocol here, I can't figure out what goes into the Unsized Envelope Record. I can't find any examples online.
ORIGINAL:
I have the following WCF service
static void Main(string[] args)
{
var inst = new PlusFiver();
using (ServiceHost host = new ServiceHost(inst,
new Uri[] { new Uri("net.pipe://localhost") }))
{
host.AddServiceEndpoint(typeof(IPlusFive), new NetNamedPipeBinding(NetNamedPipeSecurityMode.None), "PipePlusFive");
host.Open();
Console.WriteLine("Service is Available. Press enter to exit.");
Console.ReadLine();
host.Close();
}
}
[ServiceContract]
public interface IPlusFive
{
[OperationContract]
int PlusFive(int value);
}
[ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]
public class PlusFiver : IPlusFive
{
public int PlusFive(int value)
{
Console.WriteLine("Adding 5 to " + value);
return value + 5;
}
}
I output the adding 5 line so I know if the server processed the
request or not.
I have a .NET client that I used to test this and everything works as
expected.
Now I want to make an unmanaged C++ client for this.
I figured out how to get the name of the pipe, and write to it.
I've downloaded the protocol from here
I can write to the pipe but I can't read to it. Whenever I try to read from it I get a ERROR_BROKEN_PIPE 109 (0x6D) The pipe has been ended. error. If I replace the read with a write, the write is successful, so I don't think that the pipe is closed, at least not until I try to do a read.
Here is how I'm connecting to the pipe.
HANDLE OpenPipe(OLECHAR* bstrGuid)
{
wstring pipeName = L"\\\\.\\pipe\\";
wstring strGuid = bstrGuid;
pipeName.append(strGuid.substr(1,36));
wcout << "Pipe Name " << endl;
wcout << pipeName.c_str() << endl;
HANDLE hPipe = CreateFile(pipeName.c_str(), GENERIC_WRITE | GENERIC_READ, FILE_SHARE_WRITE | FILE_SHARE_READ, NULL, OPEN_EXISTING, NULL, NULL);
if(hPipe == INVALID_HANDLE_VALUE)
{
wcout << "failed to create pipe" << endl;
system("pause");
return NULL;
}
return hPipe;
}
this is how i'm creating the first message that I'm sending
std::list<wchar_t> GetFirstMessage()
{
std::list<wchar_t> message;
message.push_back(0x00);// version record
message.push_back(0x01);// major version
message.push_back(0x00);// minor version
message.push_back(0x01);// mode record
message.push_back(0x01);// singleton-unsized mode
message.push_back(0x02);// via record
wstring url = L"net.pipe://localhost/PipePlusFive";
message.push_back(url.length());// via length
for(int x= 0;x<url.length();x++)
{
message.push_back(url[x]); // via
}
message.push_back(0x03);
message.push_back(0x08);
return message;
}
This is how I'm writing it to the file.
int WriteMessage(HANDLE hPipe, LPVOID message, int size)
{
DWORD bytesWritten;
BOOL bWrite = WriteFile(hPipe, &message, size, &bytesWritten, NULL);
wcout << "Bytes Written: " << bytesWritten << endl;
if(bWrite == false)
{
wcout << "fail"<<endl;
CloseHandle(hPipe);
system("pause");
return 1;
}
return 0;
}
list<wchar_t> full_message = GetFirstMessage();
int result = WriteMessage(hPipe, &full_message, full_message.size());
if (result == 1)
{ return 1;}
Here is how I'm writing the end message
wchar_t message = 12;
result = WriteMessage(hPipe, &message, 1);
if (result == 1)
{ return 1;}
here is how I'm trying to read the response
char buffer[10];
DWORD bytesRead;
BOOL bRead = ReadFile(hPipe, buffer, 1, &bytesRead, NULL);
if(bRead == false)
{
wcout << "fail read"<<endl;
wcout << "error: " << GetLastError() << endl;
CloseHandle(hPipe);
system("pause");
return 1;
}
I'm new to c++, so I don't know if I'm not following the protocol correctly or making a stupid mistake in the way I'm trying to do this?
UPDATE:
The problem was that I was writing the pointer address to the named pipe instead of the contents of the list. I've fixed that And I'm now able to read the Preamble Ack Record. Now I have to figure out what needs to be sent for the next part of the protocol.

Answer 1

Check if this works for you
Try to open a named pipe. (CreateFile)
Set the read mode and the blocking mode of the specified named pipe. (SetNamedPipeHandleState)
Send a message to the pipe server and receive its response. (WriteFile, ReadFile)
Close the pipe. (CloseHandle)