Re: problem with pipes IPC

From:

Janma <rohitku@gmail.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Wed, 25 Feb 2009 03:51:59 -0800 (PST)

Message-ID:

<f3252fbb-3a00-4d86-a5c6-4c86051e4e69@w35g2000yqm.googlegroups.com>

My client is connecting to the pipe using the below code

CreateFile(
          g_TrayPipe, // pipe name
          GENERIC_WRITE,
          0, // no sharing
          NULL, // default security attributes
          OPEN_EXISTING, // opens existing pipe
          0, // default attributes
          NULL); // no template file

Is there a way where the admin created the named pipe, switched user
and then the non-admin tries to connect to the pipe created by admin??

Thanks,
Rohit

On Feb 25, 4:16 pm, Janma <rohi...@gmail.com> wrote:

I have created a named pipe for an admin user in the following way.

HANDLE hPipe = CreateNamedPipe(
g_TrayPipe, =

// pipe name

PIPE_ACCESS_INBOUND, =

// read/write access

PIPE_TYPE_MESSAGE | =

// message type pipe

PIPE_READMODE_MESSAGE=

| // message-read mode

PIPE_WAIT, =

// blocking mode

PIPE_UNLIMITED_INSTAN=

CES, // max. instances

BUFSIZE, =

// output buffer size

BUFSIZE, =

// input buf=
fer size

NMPWAIT_USE_DEFAULT_W=

AIT, // client time-out

NULL); =

// default security attribute

                if (INVALID_HANDLE_VALUE == hPipe)
                {
                        CloseHandle(hPipe);
                        return;
                }

Now if i log off admin user and step into a non-admin and try to
create the pipe it works fine. But if i do a switch user and go from
admin to non-admin, then non-admin user cannot create pipe with the
same name.
This is understood as the admin user's pipe is open waiting for
connection. Here the pipe is working as global.

My requirement is that i want the pipe to work as a local one just as
we can do for a mutex.

Thanks,
Rohit