Function lldesc_get_received_len

pub unsafe extern "C" fn lldesc_get_received_len(
    head: *mut lldesc_s,
    out_next: *mut *mut lldesc_s,
) -> i32

@brief Get the received length of a linked list, until end of the link or eof.

@param head The head of the linked list. @param[out] out_next Output of the next descriptor of the EOF descriptor. Return NULL if there’s no EOF. Can be set to NULL if next descriptor is not needed. @return The accumulation of the len field of all descriptors until EOF or the end of the link.