With the use of exit programs, the experienced programmer can create customized processing when an application is running. If the TFTP server finds a program registered to one of the exit points for the server, it calls that program using parameters that are defined by the exit point.
An exit point is a specific point in the TFTP program where control may pass to an exit program. An exit program is a program to which the exit point passes control.
For each exit point, there is an associated programming interface, called an exit point interface. The exit point uses this interface to pass information between the TFTP application and the exit program. Each exit point has a unique name. Each exit point interface has an exit point format name that defines how information is passed between the TFTP application and the customer-written exit program.
Different exit points may share the same exit point interface. When this is the case, multiple exit points can call a single exit program.
To allow the exit programs to work properly, you must Install and register your exit point programs. If your programs are no longer needed, you must properly Remove the exit point programs to prevent their future functioning. For more information about using exit programs, see Using server exit programs.
The following table lists exit points that give you additional control over the TFTP server.
| TCP/IP exit point | Application | Exit point format | Brief description |
|---|---|---|---|
| QIBM_QTOD_SERVER_REQ | TFTP | VLRQ0100 | The TCP/IP request validation exit point provides additional control for restricting an operation. |