Link3270 diagnostics

Link3270 messages are subject to a number of validation stages.

Validation error types

Invalid Message

If a COMMAREA is passed to DFHL3270 that is too small to contain a BRIH, or does not have the appropriate BRIH header, this will result in a transaction abend code:

ABR4: No COMMAREA
ABR5: COMMAREA too small to contain BRIH
ABR6: COMMAREA does not contain BRIH

Invalid BRIH

Only relevant fields are validated on each request. If these are invalid, then BRIH-RETURNCODE is set to BRIHRC-VALIDATION-ERROR-BRIH and BRIH-ERROROFFSET points to the field in error. The system state is not changed by a validation error. Therefore user transactions are neither started nor abended.

Invalid bridge facility

If the facility token is invalid, or has expired, this will result in BRIH-RETURNCODE being set to BRIHRC-INVALID-FACILITYTOKEN. Facilities which have expired are described by the state errors.

Invalid BRIV

BRIVs are validated as they are used. Therefore if a BRIV is not used, it is not checked. If these are invalid then BRIH-RETURNCODE is set to BRIHRC-VALIDATION-ERROR-BRIV and BRIH-ERROROFFSET points to the field in error

The transaction is abended with an ABXF abend code. BRIH-ABENDCODE is set to this value.

Invalid Application data

Application data cannot be checked by the bridge. Incorrect data will give unexpected results that may result in transaction abends or erroneous processing. You should ensure that your client program creates the data correctly. If validation of the client data is essential, you can do this by creating a program in the router region that accepts the COMMAREA, validates the ADS and then passes it to the bridge with a link to DFHL3270.

Return codes and abend codes for Link3270 message validation errors

Return codes and abend codes are provided to assist in diagnosis of errors. Note that the order in which checks are made is subject to change, and therefore should not be used as an interface.

BRIH-RETURNCODE values shows the possible values of BRIH-RETURNCODE and the contents of any related diagnostic fields (BRIH-COMPCODE and BRIH-REASON). Where no specific value is shown, these fields are set to 0.