Technical Information › User I/O Appendages

Previous Topic: Subsystems

Next Topic: Exits

User I/O Appendages

z/OS I/O appendages act as system exits that receive control before, during, or after an I/O operation. Because appendages run in an authorized state, their use is normally restricted to APF‑authorized programs. You must have read‑access authority to the SYS1.SVCLIB and the LINKLIST libraries to use this option.

Use the User I/O Appendages display (3.2) to access this information.

Auditor___________________________ Location___________________ Page____of____

Approved__________________________ CPU________________________ Date__________

Step

Description

W/P Ref

Finding

Remarks

1

Use the User I/O Appendage Analysis display (3.2) to prepare a work paper that lists the user I/O appendages installed on the system. Determine if Technical Support has adequate documentation and approvals that define the purpose, use, and function of each appendage.

 

 

 

2

From the display, determine if the users of each appendage must be APF‑authorized. Follow up on all appendages that do not require APF authorization, particularly if their description is UNKNOWN.

 

 

 

3

z/OS use the IEAAPP00 member of the logical Parmlib to specify the appendages that do not require their users to be APF‑authorized. Use the Parmlib IPL Map display (2.1.1) to select and browse IEAAPP00.

 

 

 

4

Use the Parmlib Status display (2.1.2) to determine if IEAAPP00 changed since the last review. If so, use the File History Search display (6.5) to search SMF for updates to the logical Parmlib data sets. Verify agreement with change‑authorization records.

 

 

 

5

Use the Catalog File Scan display (6.2) or your access control software to determine if the logical Parmlib data sets are protected from unauthorized access and modification.

 

 

 

6

If changes to IEAAPP00 were found in Step 4 and archival copies of the logical Parmlib data sets are available, use the File Comparison display (6.4) to determine exactly what was changed.

 

 

 

7

Using the User I/O Appendage Analysis display (3.2), select each appendage to obtain the CA Auditor I/O Appendage Review screen. Record the name of the APF library that the appendage load module was found in. Enter PENDING in the Review Status field.

 

 

 

8

Obtain a copy of the source code for each appendage, including the assembly and link edit steps.

Using the Program Statistics Display (5.2) and the library name obtained in Step 7, compare assembly and link dates, CSECT names, module size, and so on, to ensure that you have the correct source code for each appendage load module.

 

 

 

9

If you read assembler language, determine if the function of the appendage matches its documentation. If you do not, have Technical Support perform a “peer review.” In either case, return to the Appendage Review screen. Select the appendage and enter DONE in the Review Status field.

 

 

 

10

To detect changes made to appendages after this review, use the F line command to freeze the appendage load module.

 

 

 

11

Split your screen and use ISPF/PDF Copy (option 3.3) to create an archival copy of the appendage load module for subsequent review.