skb_zerocopy — Zero copy skb to skb
int skb_zerocopy ( | struct sk_buff * to, |
| struct sk_buff * from, | |
| int len, | |
int hlen); |
todestination buffer
fromsource buffer
lennumber of bytes to copy from source buffer
hlensize of linear headroom in destination buffer
Copies up to `len` bytes from `from` to `to` by creating references to the frags in the source buffer.
The `hlen` as calculated by skb_zerocopy_headlen specifies the
headroom in the `to` buffer.
everything is OK
-ENOMEM: couldn't orphan frags of from due to lack of memory
-EFAULT: skb_copy_bits found some problem with skb geometry