tlv_item
header = (void *)tlv_item(&cursor);
trailer = (void *)tlv_item(&cursor);
header = (void *)tlv_item(&cursor);
header = (void *)tlv_item(&cursor);
trailer = (void *)tlv_item(&cursor);
header = (void *)tlv_item(&cursor);
trailer = (void *)tlv_item(&cursor);
while (tlv_item(&cursor) != NULL) {