pskb_expand_head — reallocate header of sk_buff
int pskb_expand_head ( | struct sk_buff * skb, |
| int nhead, | |
| int ntail, | |
gfp_t gfp_mask); |
skbbuffer to reallocate
nheadroom to add at head
ntailroom to add at tail
gfp_maskallocation 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.