Constant esp_idf_hal::sys::pbuf_layer_PBUF_RAW_TX

pub const pbuf_layer_PBUF_RAW_TX: u32 = 0; // 0u32

Includes spare room for additional encapsulation header before ethernet headers (e.g. 802.11). Use this if you intend to pass the pbuf to functions like netif->linkoutput(). @see PBUF_LINK_ENCAPSULATION_HLEN