vfs_gethost — Get the socket host ID or name

Function

The vfs_gethost operation gets the ID or the name of the socket host.

Environment on entry and exit

Input parameter format

vfs_gethost (Token_structure,
             OSI_structure,
             Audit_structure
             Name_length,
             Name,
             Return_value,
             Return_code,
             Reason_code)

Parameters

Token_structure

Supplied parameter

Type:: TOKSTR
Length:: Specified by TOKSTR.ts_hdr.cblen.

The Token_structure represents the file system (VFS) that is being operated on. It contains the PFS's initialization token and mount token. Refer to LFS/PFS control block structure for a discussion of this structure, and to the TOKSTR typedef in BPXYPFSI in Interface structures for C language servers and clients for its mapping.

OSI_structure

Supplied and returned parameter

Type:: OSI
Length:: Specified by OSI.osi_hdr.cblen.

The OSI_structure contains information that is used by the OSI operations that may be called by the PFS. See OSI services for more information.

It also contains MVS-specific information that needs to be passed to the PFS, including SMF accounting fields, a work area, a recovery area, and an optional pointer to an output ATTR structure. For more details on the OSI structure, see The OSI structure.

This area is mapped by the OSI typedef in BPXYPFSI in Interface structures for C language servers and clients.

Audit_structure

Supplied parameter

Type:: CRED
Length:: Specified by CRED.cred_hdr.cblen.

The Audit_structure contains information that is used by the security product for access checks and auditing. It is passed to most SAF routines that are invoked by the PFS.

Refer to Security responsibilities and considerations for a discussion of security processing, and to the CRED typedef in BPXYPFSI in Interface structures for C language servers and clients for the mapping of this structure.

Name_length

Supplied and returned parameter

Type:: Integer
Length:: Fullword

A fullword that contains the length of the name. If this value is zero, the request is for the host ID. Otherwise, this is the length of the buffer to hold the name. On return, for host name, this field contains the length of the name plus one for the null.

Name

Returned parameter

Type:: String
Length:: Specified by Name_length

An area that contains the name on return, if the host name was requested. This name must be null-terminated by the PFS.

Return_value

Returned parameter

Type:: Integer
Length:: Fullword

A fullword in which the vfs_gethost operation returns the results of the operation, as one of the following:

Return_value: Meaning
-1: The operation was not successful. The Return_code and Reason_Code values must be filled in by the PFS when Return_value is -1.
0: The operation was successful (for getting the host name).
Greater than 0: The operation was successful (for getting the host ID) and is the identifier of the current host.

Return_code

Returned parameter

Type:: Integer
Length:: Fullword

A fullword in which the vfs_gethost operation stores the return code. The vfs_gethost operation returns Return_code only if Return_value is -1. For a complete list of supported return code values, see z/OS UNIX System Services Messages and Codes.

Reason_code

Returned parameter

Type:: Integer
Length:: Fullword

A fullword in which the vfs_gethost operation stores the reason code. The vfs_gethost operation returns Reason_code only if Return_value is -1. Reason_code further qualifies the Return_code value. These reason codes are documented by the PFS.

Implementation notes

Overview of vfs_gethost processing: For more information about the semantics of this operation, refer to the publications mentioned in Finding more information about sockets for the gethostid() and gethostname() functions.
Specific processing notes: The PFS determines whether to get the host name or host ID depending on Name_length. A zero length indicates a gethostid() request.
Serialization provided by the LFS: The vfs_gethost operation is invoked with an exclusive latch held on the domain of the PFS.
Security calls to be made by the PFS: None.