VOP_LISTEXTATTR(9) retrieve a list of named extended attribute from a vnode

SYNOPSIS

In sys/param.h In sys/vnode.h In sys/extattr.h Ft int Fo VOP_LISTEXTATTR Fa struct vnode *vp Fa int attrnamespace Fa struct uio *uio Fa size_t *size Fa struct ucred *cred Fa struct thread *td Fc

DESCRIPTION

This vnode call may be used to retrieve a list of named extended attributes from a specified namespace on a file or directory.

Its arguments are:

Fa vp
The vnode of the file or directory.
Fa attrnamespace
Integer constant indicating which extended attribute namespace the attribute name is present in.
Fa uio
The location of the data to be read. The resulting data will be a list of attribute names. Each list entry consists of a single byte containing the length of the attribute name, followed by the attribute name. The attribute name is not terminated by ASCII NUL
Fa size
If not NULL on return it will contain the number of bytes required to read the list. In most cases Fa uio will be NULL when Fa size is not, and vice versa.
Fa cred
The user credentials to use in authorizing the request.
Fa td
The thread requesting the extended attribute.

The Fa cred pointer may be NULL to indicate that access control checks are not to be performed, if possible. This Fa cred setting might be used to allow the kernel to authorize extended attribute retrieval that the active process might not be permitted to do.

Extended attribute semantics may vary by file system implementing the call. More information on extended attributes may be found in extattr(9).

LOCKS

The vnode will be locked on entry and should remain locked on return.

RETURN VALUES

On success, zero will be returned, and the Fa uio structure will be updated to reflect the list read. Otherwise, an appropriate error code is returned.

ERRORS

Bq Er EACCES
The caller does not have the appropriate privilege.
Bq Er ENXIO
The request was not valid in this file system for the specified vnode and attribute name.
Bq Er ENOMEM
Sufficient memory is not available to fulfill the request.
Bq Er EFAULT
The Fa uio structure refers to an invalid userspace address.
Bq Er EINVAL
The Fa namespace or Fa uio argument is invalid.
Bq Er EOPNOTSUPP
The file system does not support Fn VOP_LISTEXTATTR .