Function kern_cap_rights_limit

freebsd/kern/sys_capability.c:232–264

}

int
kern_cap_rights_limit(struct thread *td, int fd, cap_rights_t *rights)
{
	struct filedesc *fdp;
	struct filedescent *fdep;
	u_long *ioctls;
	int error;

	fdp = td->td_proc->p_fd;
	FILEDESC_XLOCK(fdp);
	fdep = fdeget_locked(fdp, fd);
	if (fdep == NULL) {
		FILEDESC_XUNLOCK(fdp);
		return (EBADF);
	}
	ioctls = NULL;
	error = _cap_check(cap_rights(fdp, fd), rights, CAPFAIL_INCREASE);
	if (error == 0) {
		seqc_write_begin(&fdep->fde_seqc);
		fdep->fde_rights = *rights;
		if (!cap_rights_is_set(rights, CAP_IOCTL)) {
			ioctls = fdep->fde_ioctls;
			fdep->fde_ioctls = NULL;
			fdep->fde_nioctls = 0;
		}
		if (!cap_rights_is_set(rights, CAP_FCNTL))
			fdep->fde_fcntls = 0;
		seqc_write_end(&fdep->fde_seqc);
	}
	FILEDESC_XUNLOCK(fdp);
	free(ioctls, M_FILECAPS);
	return (error);
}

/*
 * System call to limit rights of the given capability.