Re: [PATCH RFC net-next 1/4] ipv4: fib_rules: support match on sport, dport and ip proto

On Mon, Feb 12, 2018 at 4:03 PM, David Miller [off-list ref] wrote:

From: Eric Dumazet <redacted>
Date: Mon, 12 Feb 2018 13:54:59 -0800

quoted

We had project/teams using different routing tables for each vlan they
setup :/

Indeed, people use FIB rules and think they can scale in software.  As
currently implemented, they can't.

The example you give sounds possibly like a great VRF use case btw :-)

thanks for all the feedback so far.


replying to all the discussions on this thread so far here :):
- like davidA mentioned, we will be hardware offloading this. And the
most common hw offload case requires a 5-tuple match

- This series just extends the existing match options for people to
use the existing api if they choose too (with a performance penalty)
         - the main problem was telling people ...'oh, u cannot use ip
rules just because it does not support match on sport and so on and
there is no other way to do policy based routing on Linux'

- Regardless of this series, I think we should optimize ip rules or
have a new implementation of policy based routing. happy to hear about
possible options here:
         - optimize the existing implementation (have there been
previous discussions on possible options ?)
         - @netdev2.2, I did outline a possible option for tc to
provide an l3 hook for policy based routing (people were ok with this
and I was told more tc hooks were in the works).
            tc was a choice mainly because of all its existing match
options (flower for example). Will that help ?
         - We should have an ebpf accelerated implementation
regardless for people to use it if they want to scale rules