IRCBK Back to Index page
 
Prolog 
Control Block Contents 
   IRCBK DSECT
   IRCVRGID DSECT
   IRCVROBJ DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.


  IRCBK Prolog Top of page
 
 NAME       : HCPIRCBK
 DESCRIPTION: *IDENT Resource Communication block
 DSECT      : IRCBK
 FUNCTION   : This DSECT maps the data exchanged between the
              *IDENT system service and an authorized
              resource.
 LOCATED BY : Registers
 CREATED BY : HCPEXC when building a request for a server
              HCPEXE when processing a deliver for a request
              from a different system
              HCPIDS when getting a reply buffer for a
              server
 DELETED BY : HCPEXC when completing the function
              HCPEXD when handling a return from the server
              for the target system
              HCPEXE on an error in deliver processing
              HCPIDS on an IUCV SEND error
              HCPIDS when a message-complete interruption is
              received.
 SERIALIZED : Task ownership
 RELOCATION CONSIDERATIONS : None
 COMMENTS   :
   This control block is conceptually one piece of data
   mapped by three structures. There is a fixed-length
   portion and two variable-length portions, all described
   in greater detail below. In storage, these must be
   adjacent, and in the order:
    1) Fixed-length area
    2) Supplementary GID information
    3) Object token information.
   The fixed-length section is set up as containing a header
   and function-specific sections. The header contains only
   general control block information, and is frozen at the
   defined length. CHANGING THE LENGTH OF THE HEADER SECTION
   WILL RESULT IN MAKING THE CONTROL BLOCK INCOMPATIBLE WITH
   PREVIOUS RELEASES OF THE BLOCK.
   The function-specific sections are different, but the
   length of that section is determined by the length of
   the longest of the set of function-specific sections.
   A field in the header contains this execution-time-
   calculated length so that fields can be added to the
   function-specific section in future releases while still
   allowing the new blocks to coexist with the old ones.
   A variable-length section may contain no data; in this
   case, the length field contains the length of itself
   alone (a 4-byte length field, for example, would contain
   the value '4' if the length of the corresponding data
   field is zero).
   For future expansion, function-specific fields can be
   added to the function-specific area, or other
   function-specific sections can be added. Variable-length
   sections can be added after the last variable length
   section.
   Function type EXEC
   ------------------
   The IRCBK can reside in free storage, or in a frame
   delivered to exec processing by the CP Application
   Mailbox. When the exec function originally acquires an
   IRCBK, it does so from free storage. If the request
   is transmitted to a remote system, the CP Application
   Mailbox on that system delivers a page to the exec
   function which contains a copy of that IRCBK. That
   copy is used and the information returned to the
   originating system.
   In addition, a two-way IUCV SEND is done to the server.
   The reply buffer specified on that SEND is another copy
   of the IRCBK, gotten from free storage.
 
 
  IRCBK Control Block Content Top of page
 

 IRCBK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IRCBK *IDENT Resource Communication block Header 0000 0 Dbl-Word 8 IRCHDR (0) Ensure doubleword boundary 0000 0 Bitstring 1 IRCTYPE Type of communication with the resource. 0001 1 Bitstring 3 * Reserved for IBM use 0004 4 Signed 4 IRCTOTLN Total length (unsigned), in bytes, of the block, including the variable-length fields. 0008 8 Signed 4 IRCFFXLN Length (unsigned) in bytes of the longest of the fixed-length portions of the function-specific sections. This field can be set to IRCFIXLN by the creator of the block only. 000C 12 Character 4 * Reserved for IBM use 00000010 IRCHDRLN (*-IRCHDR) Length of the IRCBK header. 0010 16 Signed 4 IRCFNSPC (0) Beginning of the type-specific section. Information for exec() communication. 0010 16 Signed 4 IRCEX (0) Beginning of the type-specific area for exec() communication. 0010 16 Bitstring 1 IRCIDFLG ID information flag 1... .... IRCSTUID X'80' IRCSTUID Indicates that the UID should be changed. .1.. .... IRCSTGID X'40' IRCSTGID Indicates that the GID should be changed 0011 17 Character 3 * Reserved for IBM use 0014 20 Signed 4 * Reserved for IBM use. 0018 24 Signed 4 IRCEUID Effective UID. This is the user's effective UID at the time the request is made. 001C 28 Signed 4 IRCEGID Effective GID. This is the user's effective GID at the time the request is made. 0020 32 Signed 4 IRCSRET Return code from the server. If this value indicates anything other than a successful request (the field contains 0), bits zero and one of IDFLG are ignored and an error is returned to the issuer of DIAGNOSE X'280'. 0024 36 Signed 4 IRCSREAS Reason code from the server. CP passes this value to the issuer of DIAGNOSE X'280'. 0028 40 Signed 4 IRCNUID New UID. This is the UID to which the user's eUID and ssUID must be set. 002C 44 Signed 4 IRCNGID New GID. This is the GID to which the user's eGID and ssUID must be set. Reset location counter. 00000020 IRCFIXLN (*-IRCFNSPC) Length of the longest of the function-specific sections. Mapping of variable area IRCVAREX. There are two structures that start in the area beginning at IRCVAREX. One structure maps the supplementary GID length and data, and the other maps the object token length and data. Both of these sets of data are required, and they must be in the following order: 1) Supplementary GID information 2) Object token information. Supplementary GID data Note that this mapping is not part of the IRCBK DSECT and must be properly based in order to be used. The supplementary GID data length must immediately follow the last field in the function-specific section of the IRCEXEC function. The proper calculation is: (address of IRCBK + length of header section + length of function-specific section) or (IRCBK @ + IRCHDRLN + IRCFFXLN).
 IRCVRGID DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IRCVRGID *IDENT Resource Communication block 0000 0 Signed 4 IRCSGLN Length (unsigned) in bytes of the supplementary GID data, including the length field itself. This length must be equivalent to an integral number of fullwords, and must be at least equal to IRCSGMN. 00000004 IRCSGMN L'IRCSGLN Minimum length permitted to be specified in IRCSGMN. This minimum represents a IRCSGIDS length of zero. 0004 4 Signed 4 IRCSGIDS (0) Supplementary GIDs Object token data Note that this mapping is not part of the IRCBK DSECT and must be properly based in order to be used. The object length must immediately follow the last byte of the variable-length section that maps the supplementary GID data. The proper calculation is: (address of IRCBK + length of header section + length of function-specific section + length of supplementary GID data) or (IRCBK @ + IRCHDRLN + IRCFFXLN + IRCSGLN).
 IRCVROBJ DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IRCVROBJ *IDENT Resource Communication block 0000 0 Signed 4 IRCOBJLN Length (unsigned) in bytes of the object token, including the length field itself. Must be at least IRCOBJMN. 00000004 IRCOBJMN L'IRCOBJLN Minimum length permitted to be specified in IRCOBJLN. This minimum represents a IRCOBJTK length of zero. 0004 4 Bitstring 1 IRCOBJTK (0) Object token. The object token represents the object for which the UID/GIDs are being queried. For example, this could represent a setid file residing in the byte file system.
 
 
  IRCBK Storage Layout Top of page
 
 
*** IRCBK - *IDENT Resource Communication block
*
*     +------+--------------------+---------------------------+
*   0 |:TYPE |////////////////////|         IRCTOTLN          |
*     +------+--------------------+---------------------------+
*   8 |         IRCFFXLN          |///////////////////////////|
*     +---------------------------+---------------------------+
*
*** IRCBK - *IDENT Resource Communication block
 
*** Overlay for IRCFNSPC in IRCBK
*
*     +------+--------------------+---------------------------+
*  10 |:IDFLG|////////////////////|///////////////////////////|
*     +------+--------------------+---------------------------+
*  18 |         IRCEUID           |         IRCEGID           |
*     +---------------------------+---------------------------+
*  20 |         IRCSRET           |         IRCSREAS          |
*     +---------------------------+---------------------------+
*  28 |         IRCNUID           |         IRCNGID           |
*     +---------------------------+---------------------------+
*  30
*
*** Overlay for IRCFNSPC in IRCBK
 
*** IRCVRGID - *IDENT Resource Communication block
*
*     +---------------------------+
*   0 |         IRCSGLN           |
*     +---------------------------+
*
*** IRCVRGID - *IDENT Resource Communication block
 
*** IRCVROBJ - *IDENT Resource Communication block
*
*     +---------------------------+
*   0 |         IRCOBJLN          |
*     +---------------------------+
*
*** IRCVROBJ - *IDENT Resource Communication block
 
 
  IRCBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
IRCEGID        001C
IRCEUID        0018
IRCEX          0010
IRCFFXLN       0008
IRCFIXLN       002C 00000020
IRCFNSPC       0010
IRCHDR         0000
IRCHDRLN       000C 00000010
IRCIDFLG       0010
IRCNGID        002C
IRCNUID        0028
IRCOBJLN       0000
IRCOBJMN       0000 00000004
IRCOBJTK       0004
IRCSGIDS       0004
IRCSGLN        0000
IRCSGMN        0000 00000004
IRCSREAS       0024
IRCSRET        0020
IRCSTGID       0010 40
IRCSTUID       0010 80
IRCTOTLN       0004
IRCTYPE        0000
 
This information is based on z/VM 6.4.0 Last updated on 24 Aug 2016 at 09:25:49 EDT.
Copyright IBM Corporation, 1990, 2016