tipc_buf_append
if (tipc_buf_append(reasm_skb, &skb)) {
if (!tipc_buf_append(reasm_tnlmsg, &skb)) {
if (tipc_buf_append(&tmp, &skb)) {
if (tipc_buf_append(&head, &frag))
int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf);