A pointer to an ACL structure from which to retrieve the ACL data.
cred
The user credentials to use in authorizing the request.
td
The thread checking the ACL.
The 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.
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 acl(9).