On 12/01/2015 08:13 PM, Andi Kleen wrote:
Lorenzo Colitti <lore...@google.com> writes:On Wed, Nov 25, 2015 at 5:32 AM, Matt Bennett <matt.benn...@alliedtelesis.co.nz> wrote:I'm emailing this list for feedback on the feasibility of increasing skb->mark or adding a new field for marking. Perhaps this extension could be done under a new CONFIG option.64-bit marks (both skb->mark and sk->sk_mark) would be useful for hosts doing complex policy routing as well. Current Android releases use 20 of the 32 bits. If the mark were 64 bits, we could put the UID in it, and stop using ip rules to implement per-UID routing.This would be be great. I've recently ran into some issues with the overhead of the Android firewall setup. So basically you need 4 extra bytes in sk_buff. How about: - shrinking skb->priority to 2 byte
That wouldn't work, see SO_PRIORITY and such (4 bytes) ...
- skb_iff is either skb->dev->iff or 0. so it could be replaced with a single bit flag for the 0 case.
... and that one wouldn't work on ingress.
Hmm, thinking out loud, maybe it makes sense to combine {mark, priority}
into a mark64 field as union, if the use-case allows to ignore/overwrite
priorities set by applications, or to infer them otherwise based on
different policies like net_prio cgroup (see skb_update_prio()).
--
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
