skb_put() -- 扩展数据缓冲区大小

skb_put() -- 扩展缓冲区中数据区域的大小；增加len个字节

/usr/src/linux-2.6.19/include/linux/skbuff.h
static inline unsigned char *skb_put(struct sk_buff *skb, unsigned int len)
{
    unsigned char *tmp = skb->tail;
    SKB_LINEAR_ASSERT(skb);
    skb->tail += len;
    skb->len += len;
    if (unlikely(skb->tail>skb->end))
        skb_over_panic(skb, len, current_text_addr());
    return tmp;
}