-/* Attempts to receive a packet from 'netdev' into 'buffer', which the caller
- * must have initialized with sufficient room for the packet. The space
- * required to receive any packet is ETH_HEADER_LEN bytes, plus VLAN_HEADER_LEN
- * bytes, plus the device's MTU (which may be retrieved via netdev_get_mtu()).
- * (Some devices do not allow for a VLAN header, in which case VLAN_HEADER_LEN
- * need not be included.)
- *
- * This function can only be expected to return a packet if ->listen() has
- * been called successfully.
- *
- * If a packet is successfully retrieved, returns 0. In this case 'buffer' is
- * guaranteed to contain at least ETH_TOTAL_MIN bytes. Otherwise, returns a
- * positive errno value. Returns EAGAIN immediately if no packet is ready to
- * be returned.
- *
- * Some network devices may not implement support for this function. In such
- * cases this function will always return EOPNOTSUPP. */