Retrieves the access control list (ACL) for a file. This is an advanced version of vnop_getacl interface.
#include <sys/acl.h>
int vnop_getxacl (vp, ctl_flags, acl_type, uiop, acl_len, mode_info, crp)
struct vnode *vp;
uint64_t ctl_flags;
acl_type_t *acl_type;
struct uio *uiop;
size_t *acl_len;
mode_t *mode_info;
struct ucred *crp;
The vnop_getxacl entry point retrieves the access control list (ACL) for a file system object. It is an advanced version of vnop_getacl interface and provides for ACL-type-based operations. Note that this interface can be used to obtain the ACL type and length information, without actually retrieving the ACL data (see the ctl_flags description for more details).
| Item | Description |
|---|---|
| vp | Specifies the virtual node (v-node) of the file system object. |
| acl_type | Points to buffer space for file systems to return
the ACL type associated with the file system object. The value should
normally be set to ACL_ANY or 0 when the call is made. Some
physical file systems can solicit ACL requests for a particular ACL
type. In such cases, the caller provides the ACL type requested in
this buffer. Note: The latter issue is file system implementation
specific. For example, when ACL information is requested with an input
ACL type, a physical file system might return an error if the existing
ACL associated with the file system object is of a different ACL type.
Or, the file system might emulate an ACL of the type requested and
return.
|
| acl_len | Pointer to a length variable. The space pointed to is used as an input, as well as output, parameter. As input, the value will indicate the size of buffer uiop. When the call returns, this space holds the actual length of the ACL (true for when the call is successful or when the call fails with errno set to ENOSPC). |
| ctl_flags | A 64-bit bit mask that provides control over
the ACL retrieval and for any future variations in the interface.
The following value is defined for these flags:
|
| uiop | Specifies the uio structure that provides space for the store of the ACL. |
| mode_info | This value indicates any mode word information that needs to be retrieved for the file system object as part of this ACL get operation. |
| crp | Points to the cred structure. This structure contains data that the file system can use to validate access permission. |
The vnop_getxacl entry point can be called from the process environment only.
Upon successful completion, the vnop_getxacl entry point returns 0. Nonzero return values are returned from the /usr/include/sys/errno.h file to indicate failure.
| Item | Description |
|---|---|
| ENOSPC | Indicates that the buffer size specified in the uiop parameter was not large enough to hold the ACL. |