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.\" Copyright (c) 1999 Robert N. M. Watson
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.Dd December 23, 1999
.Dt VOP_ACLCHECK 9
.Os
.Sh NAME
.Nm VOP_ACLCHECK
.Nd check an access control list for a vnode
.Sh SYNOPSIS
.In sys/param.h
.In sys/vnode.h
.In sys/acl.h
.Ft int
.Fn VOP_ACLCHECK "struct vnode *vp" "acl_type_t type" "struct acl *aclp" "struct ucred *cred" "struct thread *td"
.Sh DESCRIPTION
This vnode call may be used to determine the validity of a particular access
control list (ACL) for a particular file or directory.
.Pp
Its arguments are:
.Bl -tag -width type
.It Fa vp
The vnode of the file or directory.
.It Fa type
The type of ACL to check.
.It Fa aclp
A pointer to an ACL structure from which to retrieve the ACL data.
.It Fa cred
The user credentials to use in authorizing the request.
.It Fa td
The thread checking the ACL.
.El
.Pp
The
.Fa cred
pointer may be NULL to indicate that access control checks are not to be
performed, if possible.
This cred setting might be used to allow the
kernel to authorize ACL verification that the active process might not be
permitted to do.
.Pp
The vnode ACL interface defines the syntax, and not semantics, of file and
directory ACL interfaces.
More information about ACL management in kernel
may be found in
.Xr acl 9 .
.Sh LOCKS
No locks are required to call this vnode method, and any locks held on
entry will be held on exit.
.Sh RETURN VALUES
If the
.Fa aclp
pointer points to a valid ACL of type
.Fa type
for the object
.Fa vp ,
then zero is returned.
Otherwise, an appropriate error code is returned.
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EINVAL
The ACL type passed is invalid for this vnode, or the ACL data is invalid.
.It Bq Er EACCES
The file or directory ACL does not permit access.
.It Bq Er ENOMEM
Sufficient memory is not available to fulfill the request.
.It Bq Er EOPNOTSUPP
The file system does not support
.Fn VOP_ACLCHECK .
.El
.Sh SEE ALSO
.Xr acl 9 ,
.Xr vnode 9 ,
.Xr VOP_GETACL 9 ,
.Xr VOP_SETACL 9
.Sh AUTHORS
This manual page was written by
.An Robert Watson .