Function mbedtls_ssl_conf_dbg 

pub unsafe extern "C" fn mbedtls_ssl_conf_dbg(
    conf: *mut mbedtls_ssl_config,
    f_dbg: Option<unsafe extern "C" fn(*mut c_void, i32, *const u8, i32, *const u8)>,
    p_dbg: *mut c_void,
)

\brief Set the debug callback

            The callback has the following argument:
            void *           opaque context for the callback
            int              debug level
            const char *     file name
            int              line number
            const char *     message

\param conf SSL configuration \param f_dbg debug function \param p_dbg debug parameter