On Thu, Apr 16, 2015, at 07:29, Herbert Xu wrote: > On Thu, Apr 16, 2015 at 06:24:00AM +0100, Patrick McHardy wrote: > > > > Netfilter may change the contents of the packet, even change its size. > > It is *really* hard to do this while keeping the original fragments > > intact. > > Perhaps we should provide better helpers to facilitate this? > > So instead of directly manipulating the content of the skb you > would so so through helpers and the helpers can then try to do > sensible things with the fragments.
When Florian and me started discussing how to solve this we also wanted to be as transparent as possible. But looking at all possible fragmentation scenarios, this seems to be too complicated. Even imagine a fragment with overlapping offsets and some of the fragments got duplicated. If we had to keep this in frag_list and now netfilter has to change any of this contents, this will become a total mess, like changing one port in multiple skbs at different offsets. I doubt it is worth the effort. Thanks, Hannes -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
