Format of IRM extensions

You can use IMS request message (IRM) extensions to send information from IMS Connect client applications without expanding the DSECT that maps the IRM.

The number of IRM extensions in each IRM can vary, and you can define the IRM extensions in the IRM in any order. All IRM extensions contain a 12-byte header. User message exits use the unique identifier (ID) for each IRM extension to determine the contents of the extension. By default, the user message exits process IRM extension IDs as EBCDIC and IRM extension data as binary data. If the IRM extension ID and extension data are not defined in EBCDIC and binary data respectively, modify the user message exit or the TCP/IP application.

Different IRM extensions are supported by different user message exits. If an IRM containing IRM extensions is processed by a user message exit that does not support the extensions, the extensions are ignored.

Table 1. Format of IRM extensions
Field Length Hexadecimal offset Description and settings
IRMEXTN_LL 2 0 Length of this IRM extension.
IRMEXTN_ZZ 2 2 Reserved field.
IRMEXTN_ID 8 4 The unique ID for this IRM extension. Each ID begins and ends with an asterisk (*).
The following IDs can be defined for this field:
*CONTXT*
Indicates that the IRM extension contains context information. This ID is encoded in EBCDIC or ASCII and is supported by the HWSSOAP1 user message exit.
*TRCKID*
Indicates that the IRM extension contains a tracking ID. This ID is encoded in EBCDIC or ASCII and is supported by the HWSSOAP1 user message exit.
*PHRASE*
Indicates that the IRM extension contains a RACF® password phrase. This ID is encoded in EBCDIC and is supported by the HWSJAVA0 user message exit.
*NETUID*
Indicates that the IRM extension contains a network security user ID. This ID is encoded in EBCDIC or ASCII and is supported by the HWSSMPL0 and HWSSMPL1 user message exits.
*NETSID*
Indicates that the IRM extension contains a network security session ID. This ID is encoded in EBCDIC or ASCII and is supported by the HWSSMPL0 and HWSSMPL1 user message exits.
IRMEXTN_DATA * 12 This field can be used to locate the variable length data that immediately follow the IRM extension ID. The structure of this data depends on the IRM extension ID. By default, the IRM extension data is treated as binary data.