Global Signon Defaults

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The IBM® Connect:Direct® administrator can define global signon defaults so that users do not have to individually alter their signon default values to increase their allocation. By implementing a global signon default, you can avoid insufficient space being allocated for the temporary data set upon signon as well as SB37 ABENDs.

A temporary data set (TEMP DSN) is allocated at SIGNON to the IUI, which uses the system default allocation parameters. At times, this allocation is insufficient causing SB37 failures if a large amount of data is returned for a command request. The facilities available via SIGNON defaults (SD) are not global and each individual user must alter their default values to increase the allocation.

Also, the option to skip the IUI SIGNON panel when using the Stage1 Security exit can be specified using the SSOP option described below. Likewise, the values for the Signon Dummy Passwords can be changed using parameters described below.

To change the default values, use member DGAXCXDF from $CD.SDGASAMP to assemble and link module DGAXCXDF with the new values for TEMP DSN. You can edit and submit $CD.SDGAJCL member DGAJCXDF to do the assembly and link edit. Once the module is assembled and linked, all user who sign on via an API will be subject to the new default global signon settings.

After you implement global signon defaults, allocation parameters during SIGNON can come from the following three sources, which are listed from lowest to highest precedence:

Defaults from macro DGA$UICB specified by programs such as DGADBATC, DGADCHLA, and DGADCMDP. This is considered a legacy source of SIGNON allocation parameters.

Note: Users including the administrator, do not have control over these programs.

The SIGNON command, whose parameters come from wherever the invoker of the command decides, for example, the IUI can save SIGNON parameters in a user's ISPF profile dataset. Like the DGA$UICB macro, this is considered a legacy source of SIGNON allocation parameters.
The DGAXCXDF load module, which the administrator can control.

DGA$XDEF Syntax and Parameters

$CD.SDGASAMP member DGAXCXDF consists of one statement, the macro DGA$XDEF, in $CD.SDGAMAC and should not be changed. To modify the DGAXCXDF member, first copy it and then alter it to suit your installation's requirements.

The following shows the DGA$XDEF syntax and defaults:

DMCXDEFS DGA$XDEF OVERRIDE=ALLOW,  DISALLOW,ALLOW,ALLOWGT,ALLOWLT      +
               ALOCTYPE=CYL,       CYL,TRK,BLK                         +
               ALOCPRI=1,          PRIMARY SPACE AMOUNT                +
               ALOCSEC=1,          SECONDARY SPACE AMOUNT              +
               ALOCUNIT=,          UNITNAME                            +
               ALOCVOL=,           VOLSER                              +
               SSOP=N,             SKIP SIGNON PANEL W/STG1            +
               PSWFRC=N,           FORCE USE OF DUMMY PASSWORDS        +
               PSWBAT=BATCH,       DEFAULT PSW FOR BATCH TASKS         +
               PSWIUI=IUI,         DEFAULT PSW FOR TSO/IUI TASKS       +
               PSWSTC=STC          DEFAULT PSW FOR STC TASKS

The following table lists the parameters that make up the DGA$XDEF load module:

Parameter	Description
OVERRIDE	Specifies when a legacy source can override the global signon defaults assigned by the DGA$XDEF load module. If not specified, defaults to ALLOW (a null value is invalid). Values are: DISALLOW— DGA$XDEF always supplies all allocation parameters. ALLOW—A legacy source can override DGA$XDEF parameter by parameter. ALLOWGT—A legacy source can override DGA$XDEF if the maximum space it would allocate is greater than the maximum space that DGA$XDEF would allocate. Otherwise, DGA$XDEF overrides the legacy source. With this setting, whichever source can supply more space will be used. Note that, unlike ALLOW, the winning source in ALLOWGT is required to supply all allocation parameters. ALLOWLT—A legacy source can override DGA$XDEF if the maximum space it would allocate is less than the maximum space that DGA$XDEF would allocate. Otherwise, DGA$XDEF overrides the legacy source. With this setting, whichever source limits the maximum space more is used. Note that, like ALLOWGT, the winning source in ALLOWLT is required to supply all allocation parameters.
ALOCTYPE	Specifies the allocation type. If not specified, defaults to space allocation by cylinder–CYL (a null value is invalid).
ALOCPRI	Specifies the primary allocation of storage. If not specified, defaults to a o1.
ALOCSEC	Specifies the secondary allocation of storage. If not specified, defaults to a o1.
ALOCUNIT	Specifies the unit type of the TEMP DSN. If not specified, has no default.
ALOCVOL	Specifies volume serial number of the TEMP DSN. If not specified, has no default.
SSOP	Specifies whether to skip the IUI SIGNON panel when Stage 1 Security exit is being used. With the Stage 1 Security exit, user is coming from a secured environment so that passwords are not required. Therefore, the SIGNON panel can be skipped. Valid values are Y to skip the panel or N to continue invoking the SIGNON panel. Default is N.
PSWFRC	Specifies whether to force the use of Signon Dummy Password values based on the host environment. Valid values can be N (the default) which will not force the use of Signon Dummy Passwords or Y which will use Signon Dummy Passwords even is a password is supplied by the user. Give careful consideration before setting this parameter to Y. This parameter is implemented by code in the Stage 1 Security exit.
PSWBAT	Specifies the value to use for Signon Dummy Passwords when coming from a batch JOB environment. Default is BAT but can be set to any 8 character alphanumeric value. This value is used by both the Stage 1 and Stage 2 Security exits.
PSWIUI	Specifies the value to use for Signon Dummy Passwords when coming from a TSO IUI environment. Default is IUI but can be set to any 8 character alphanumeric value. This value is used by both Stage 1 and Stage 2 Security exit.
PSWSTC	Specifies the value to use for Signon Dummy Passwords when coming from a Started Task environment. Default is STC but can be set to any 8 character alphanumeric value. This value is used by both Stage 1 and Stage 2 Security exits.

The other DGA$XDEF macro parameters are converted into the well known JCL space parameters. All DGA$XDEF macro parameters other than OVERRIDE are converted into the JCL SPACE parameters and can take any valid value that can be specified in JCL. The one exception is that the ALOCTYPE parameter supports only TRK (Track) and CYL (Cylinder).

ISPF Messages Displayed During Signon

If the DGAXCXDF load module was successfully located at IUI SIGNON, new ISPF messages are displayed upon entry to the IUI Signon Defaults (SD) panel. (If DGAXCXDF was not present at IUI SIGNON, no ISPF message is displayed.) Both the short and long message components are generated. The exact text of the ISPF messages is based on:

Settings in the DGAXCXDF load module,at the time of SIGNON
The user's ISPF profile variables for the temporary data set

The user will see one of the following ISPF short messages, which states what the DGAXCXDF OVERRIDE setting was when they signed on:

OVERRIDE=DISALLOW
OVERRIDE=ALLOW
OVERRIDE=ALLOWGT
OVERRIDE=ALLOWLT

The ISPF long message component provides the following information:

The values for the current temporary data set allocation
An explanation of where the values came from and why

The following is an example of a typical ISPF long message example:

   .------------------------------------------------------------------.
   | The current Temporary Data Set space settings are:  ALLOCATION   |
   | TYPE=CYL, PRIMARY SPACE=00000001, SECONDARY SPACE=00000001, UNIT |
   | TYPE=, VOL=SER=.  These are from the Global Signon Default       |
   | module DGAXCXDF, because OVERRIDE=ALLOWGT is specified, and the  |
   | maximum space specified by this panel/DGA$UICB was not greater   |
   | than that specified by DGAXCXDF.                                 |
   '------------------------------------------------------------------'

Note: In the message above, the phrase, this panel/DGA$UICB, is the same thing as saying a legacy source of SIGNON allocation parameters.