|VACCESS_ACL_NFS4(9)||Kernel Developer's Manual||VACCESS_ACL_NFS4(9)|
generate a NFSv4 ACL access control decision using vnode
type, uid_t file_uid, gid_t
file_gid, struct acl *acl,
accmode_t accmode, struct ucred
*cred, int *privused);
This call implements the logic for the
UNIX discretionary file security model with NFSv4
ACL extensions. It accepts the vnodes type type,
owning UID file_uid, owning GID
file_gid, access ACL for the file
acl, desired access mode
accmode, requesting credential
cred, and an optional call-by-reference
int pointer returning whether or not privilege was
required for successful evaluation of the call; the
privused pointer may be set to
NULL by the caller in order not to be informed of
privilege information, or it may point to an integer that will be set to 1
if privilege is used, and 0 otherwise.
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
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
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
entry from the access ACL, which may then be composed with an available ACL
mask entry, providing UNIX security
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.
vaccess_acl_nfs4() will return 0 on
success, or a non-zero error value on failure.
Current implementation of
vaccess_acl_nfs4() was written by
Edward Tomasz Napierala
This manual page should include a full description of the NFSv4 ACL evaluation algorithm, or cross reference another page that does.
|September 18, 2009||Debian|