Pipe permission when using CreatePipe RRS feed

  • Question

  • Hi everyone.
    I'm doing a project related to named pipe. I used CreatePipe to create a new named pipe, and then, another process will read content of pipe. In this case, I only want Process 1 create a pipe with Write permission (I don't want it to have READ permission) and Process 2 will have READ permission only.
    In process 1, I use this Function:
    hPipe = CreateNamedPipe( 
    lpszPipename, // pipe name
    PIPE_ACCESS_OUTBOUND , // write access
    PIPE_TYPE_MESSAGE | // message type pipe
    PIPE_READMODE_MESSAGE | // message-read mode
    PIPE_WAIT, // blocking mode
    PIPE_UNLIMITED_INSTANCES, // max. instances
    BUFSIZE, // output buffer size
    BUFSIZE, // input buffer size
    0, // client time-out

    In Process 2, I use CreateFile function to open Pipe, like this:
    hPipe = CreateFile( 
    lpszPipename, // pipe name
    GENERIC_READ , // read access
    0, // no sharing
    NULL, // default security attributes
    OPEN_EXISTING, // opens existing pipe
    0, // default attributes
    NULL); // no template file
    The problem is, I cannot change to message_read mode in process 2, it always have error and exit
    fSuccess = SetNamedPipeHandleState(
    hPipe, // pipe handle
    &dwMode, // new pipe mode
    NULL, // don't set maximum bytes
    NULL); // don't set maximum time

    if ( ! fSuccess) //fSuccess is always FALSE, I don't understand this
    _tprintf( TEXT("SetNamedPipeHandleState failed. GLE=%d\n"), GetLastError() );
    return -1;
    Thank you very much for paying attention to this question
    Saturday, November 21, 2009 12:52 AM