- int pskb_expand_head(struct sk_buff * skb, int nhead, int ntail, gfp_t gfp_mask);
- buffer to reallocate
- room to add at head
- room to add at tail
- allocation priority
Expands (or creates identical copy, if nhead and ntail are zero) header of skb. sk_buff itself is not changed. sk_buff MUST have reference count of 1. Returns zero in the case of success or error, if expansion failed. In the last case, sk_buff is not changed.
All the pointers pointing into skb header may change and must be reloaded after call to this function.