Since it is not possible to reenter the function `esp_now_recv_cb`, and the functions netif::_ recv and esp_now_netdev::_ recv are called directly in the same thread context we can read directly from the `buf` and don't need a receive buffer anymmore.
Since it is not possible to reenter the function `esp_now_recv_cb`, and the functions netif::_ recv and esp_now_netdev::_ recv are called directly in the same thread context we only need a buffer which contains one frame and its source mac address.
Since it is not possible to reenter the function `esp_now_recv_cb`, and the functions netif::_ recv and esp_now_netdev::_ recv are called directly in the same thread context, neither a mutual exclusion has to be realized nor have the interrupts to be deactivated.
Since the esp_now_recv_cb function is not called directly as an ISR through interrupts, it is not executed in the interrupt context. _recv can therefore be called directly. The treatment of the recv_event is no longer necessary.
Avoids parsing IPv6 packets to determine destination address.
Allows using 6Lo over ESP-NOW, which is required due to the low MTU of
ESP-NOW.
Co-authored-by: Gunar Schorcht <gunar@schorcht.net>
