batadv_skb_cb
memset(skb->cb, 0, sizeof(struct batadv_skb_cb));
BUILD_BUG_ON(sizeof(struct batadv_skb_cb) > i);
#define BATADV_SKB_CB(__skb) ((struct batadv_skb_cb *)&((__skb)->cb[0]))
memset(skb->cb, 0, sizeof(struct batadv_skb_cb));