PAM_BINDING
(modulep->pam_flag & PAM_BINDING) ?
if (flag & PAM_BINDING)
(*pam)->pam_flag = PAM_BINDING;
#define PAM_REQRD_BIND (PAM_REQUIRED | PAM_BINDING)
#define PAM_SUFFI_BIND (PAM_SUFFICIENT | PAM_BINDING)