From: Shmulik Ladkani
Date: Mon, 29 Apr 2019 16:39:30 +0300
> Previously, during fragmentation after forwarding, skb->skb_iif isn't
> preserved, i.e. 'ip_copy_metadata' does not copy skb_iif from given
> 'from' skb.
>
> As a result, ip_do_fragment's creates fragments with zero skb_iif,
> leading
Previously, during fragmentation after forwarding, skb->skb_iif isn't
preserved, i.e. 'ip_copy_metadata' does not copy skb_iif from given
'from' skb.
As a result, ip_do_fragment's creates fragments with zero skb_iif,
leading to inconsistent behavior.
Assume for example an eBPF program attached at
