Function esp_idf_sys::os_mbuf_prepend

pub unsafe extern "C" fn os_mbuf_prepend(
    om: *mut os_mbuf,
    len: c_int,
) -> *mut os_mbuf

Increases the length of an mbuf chain by adding data to the front. If there is insufficient room in the leading mbuf, additional mbufs are allocated and prepended as necessary. If this function fails to allocate an mbuf, the entire chain is freed.

The specified mbuf chain does not need to contain a packet header.

@param omp The mbuf pool to allocate from. @param om The head of the mbuf chain. @param len The number of bytes to prepend.

@return The new head of the chain on success; NULL on failure.