GENFS_CAN_ACCESS_ACL_NFS4(9) FreeBSD Kernel Developer's Manual
NAME
genfs_can_access_acl_nfs4 - generate a NFSv4 ACL access control decision
using vnode parameters
SYNOPSIS
#include <miscfs/genfs/genfs.h>
int
genfs_can_access_acl_nfs4(
genfs_can_access_acl_nfs4(struct vnode *, kauth_cred_t, uid_t,
gid_t,
mode_t, struct acl *, accmode_t) struct vnode *vp,
kath_cred_t cred, uid_t file_uid, gid_t file_gid, mode_t file_mode,
struct acl *acl, accmode_t accmode);
DESCRIPTION
This call implements the logic for the UNIX discretionary file security
model with NFSv4 ACL extensions. It accepts the vnode vp, requesting
credential cred, owning UID file_uid, owning GID file_gid, file
permissions file_mode, access ACL for the file acl, desired access mode
accmode,
This call is intended to support implementations of VOP_ACCESS(9), which
will use their own access methods to retrieve the vnode properties, and
then invoke genfs_can_access_acl_nfs4() in order to perform the actual
check. Implementations of VOP_ACCESS(9) may choose to implement
additional security mechanisms whose results will be composed with the
return value.
The algorithm used by genfs_can_access_acl_nfs4() is based on the NFSv4
ACL evaluation algorithm, as described in NFSv4 Minor Version 1, draft-
ietf-nfsv4-minorversion1-21.txt. The algorithm selects a matching entry
from the access ACL, which may then be composed with an available ACL
mask entry, providing UNIX security compatibility.
Once appropriate protections are selected for the current credential, the
requested access mode, in combination with the vnode type, will be
compared with the discretionary rights available for the credential. If
the rights granted by discretionary protections are insufficient, then
super-user privilege, if available for the credential, will also be
considered.
RETURN VALUES
genfs_can_access_acl_nfs4() will return 0 on success, or a non-zero error
value on failure.
ERRORS
[EACCES] Permission denied. An attempt was made to access a
file in a way forbidden by its file access
permissions.
[EPERM] Operation not permitted. An attempt was made to
perform an operation limited to processes with
appropriate privileges or to the owner of a file or
other resource.
SEE ALSO
genfs_can_access(9), vnode(9), VOP_ACCESS(9)
AUTHORS
Current implementation of genfs_can_access_acl_nfs4() was written by
Edward Tomasz Napierala <
[email protected]>.
BUGS
This manual page should include a full description of the NFSv4 ACL
evaluation algorithm, or cross reference another page that does.
FreeBSD 14.1-RELEASE-p8 September 18, 2009 FreeBSD 14.1-RELEASE-p8