HP NonStop G-Series - Manual (Page 105)

Creating an RSC Logon Function and Dialog
Extending the Tandem DDE Gateway
110838 Tandem Computers Incorporated 8–3
Example MAKE files (with a MAK file extension) are provided for the RSC logon
function and the User Hook Library. You can find them in the EXTEND\
subdirectory.
The MAKE files use an object module called LIBENTRY.OBJ. This is the standard
entry prologue for dynamic link libraries (DLLs) and is provided with your C
language development environment.
If the Tandem DDE Gateway does not exit normally (for example, if you get a
protection violation in your User Hook Library code while debugging), then some of
its dynamic link libraries may stay loaded in workstation memory. This can cause
unexpected error messages when the Tandem DDE Gateway is restarted and
connections to the Tandem system are made. Shutting down and restarting Windows
will clear the error situation. Rebooting the workstation should not be necessary.
Creating an RSC
Logon Function and
Dialog
You can change the RSC logon dialog box and associated security processing logic.
When you configure the PortName objects in Tandem DDE Gateway for your
workstation, use the UseRscSecurity attribute to be prompted for a User ID and
password whenever you connect the PortName object. The User ID and password
entered are verified by an RSC Access Control Server that you write and configure
with RSC on the Tandem system.
To create a replacement RSC logon function and dialog box, you need a Windows C
language development environment capable of creating a dynamic link library (DLL).
Follow these steps to develop a replacement RSC logon function:
1. Copy the files RSCLOGON.* from the EXTEND\ subdirectory.
2. Use your dialog box editor to change the default dialog box.
3. Modify the TdmgwRscLogon function in the RSCLOGON.C file to meet your
application’s requirements (and develop a related RSC Access Control Server on
the Tandem system—an example is provided in the file ACSS in the subvolume on
the Tandem system where you installed the Tandem DDE Gateway).
4. Compile your new RSC logon program to create a new RSCLOGON.DLL file.
5. Stop the Tandem DDE Gateway.
6. Backup the old RSCLOGON.DLL file from the GW\ subdirectory and replace it
with your new RSCLOGON.DLL.
7. Restart the Tandem DDE Gateway.
TdmgwRscLogon This function is called when you attempt to connect a PortName object for which the
UseRscSecurity configuration option is set to 1.
If you return a value of zero to indicate an error, then the connection attempt for the
PortName will be aborted and an error message will be displayed by the Tandem DDE
Gateway.