How to send messages between c++ .dll and C# app using named pipe?
- by Gal
I'm making an injected .dll written in C++, and I want to communicate with a C# app using named pipes.
Now, I am using the built in System.IO.Pipe .net classes in the C# app, and I'm using the regular functions in C++.
I don't have much experience in C++ (Read: This is my first C++ code..), tho I'm experienced in C#.
It seems that the connection with the server and the client is working, the only problem is the messaged aren't being send. I tried making the .dll the server, the C# app the server, making the pipe direction InOut (duplex) but none seems to work.
When I tried to make the .dll the server, which sends messages to the C# app, the code I used was like this:
DWORD ServerCreate() // function to create the server and wait till it successfully creates it to return.
{
hPipe = CreateNamedPipe(pipename,//The unique pipe name. This string must have the following form: \\.\pipe\pipename
PIPE_ACCESS_DUPLEX,
PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_NOWAIT, //write and read and return right away
PIPE_UNLIMITED_INSTANCES,//The maximum number of instances that can be created for this pipe
4096 , // output time-out
4096 , // input time-out
0,//client time-out
NULL);
if(hPipe== INVALID_HANDLE_VALUE)
{
return 1;//failed
}
else
return 0;//success
}
void SendMsg(string msg)
{
DWORD cbWritten;
WriteFile(hPipe,msg.c_str(), msg.length()+1, &cbWritten,NULL);
}
void ProccesingPipeInstance()
{
while(ServerCreate() == 1)//if failed
{
Sleep(1000);
}
//if created success, wait to connect
ConnectNamedPipe(hPipe, NULL);
for(;;)
{
SendMsg("HI!");
if( ConnectNamedPipe(hPipe, NULL)==0)
if(GetLastError()==ERROR_NO_DATA)
{
DebugPrintA("previous closed,ERROR_NO_DATA");
DisconnectNamedPipe(hPipe);
ConnectNamedPipe(hPipe, NULL);
}
Sleep(1000);
}
And the C# cliend like this:
static void Main(string[] args)
{
Console.WriteLine("Hello!");
using (var pipe = new NamedPipeClientStream(".", "HyprPipe", PipeDirection.In))
{
Console.WriteLine("Created Client!");
Console.Write("Connecting to pipe server in the .dll ...");
pipe.Connect();
Console.WriteLine("DONE!");
using (var pr = new StreamReader(pipe))
{
string t;
while ((t = pr.ReadLine()) != null)
{
Console.WriteLine("Message: {0}",t);
}
}
}
}
I see that the C# client connected to the .dll, but it won't receive any message..
I tried doing it the other way around, as I said before, and trying to make the C# send messages to the .dll, which would show them in a message box.
The .dll was injected and connected to the C# server, but when It received a message it just crashed the application it was injected to.
Please help me, or guide me on how to use named pipes between C++ and C# app
