Programming Interface Information:
This information is NOT intended to be used as Programming Interfaces of z/VM. |
IRCBK
Control Block Contents
IRCBK DSECT
IRCVRGID DSECT
IRCVROBJ DSECT
Cross Reference (Contains links to field and bit definitions)
IRCBK Prolog
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 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
IRCBK DSECT
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' Indicates that the UID should be changed. .1.. .... IRCSTGID X'40' 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
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
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
*** 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
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 V4R2.0. Last updated on 30 Oct 2001 at 15:39:15 EDT.
Copyright IBM Corporation, 1990, 2001