Re: [Patch net-next] net_sched: add network namespace support for tc actions

[Daniel Borkmann <daniel@iogearbox.net>]

On 02/20/2016 01:43 AM, Cong Wang wrote:
> Currently tc actions are stored in a per-module hashtable,
> therefore are visible to all network namespaces. This is
> probably the last part of the tc subsystem which is not
> aware of netns now. This patch makes them per-netns,
> several tc action API's need to be adjusted for this.
>
> The tc action API code is ugly due to historical reasons,
> we need to refactor that code in the future.
>
> Also this patch is on top of my other patch
> "net_sched: fix memory leaks when rmmod tc action modules",
> therefore should be applied after -net is merged into
> net-next.
>
> Cc: Jamal Hadi Salim <jhs@mojatatu.com>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
> ---
>   include/net/act_api.h    |  28 +++++---
>   net/sched/act_api.c      |  88 ++++++++++-------------
>   net/sched/act_bpf.c      |  71 +++++++++++++++++--
>   net/sched/act_connmark.c |  73 +++++++++++++++++--
>   net/sched/act_csum.c     |  78 +++++++++++++++++++--
>   net/sched/act_gact.c     |  74 ++++++++++++++++++--
>   net/sched/act_ipt.c      | 178 +++++++++++++++++++++++++++++++++++++++++++----
>   net/sched/act_mirred.c   |  75 ++++++++++++++++++--
>   net/sched/act_nat.c      |  73 +++++++++++++++++--
>   net/sched/act_pedit.c    |  73 +++++++++++++++++--
>   net/sched/act_police.c   |  69 ++++++++++++++++--
>   net/sched/act_simple.c   |  76 ++++++++++++++++++--
>   net/sched/act_skbedit.c  |  73 +++++++++++++++++--
>   net/sched/act_vlan.c     |  73 +++++++++++++++++--
>   14 files changed, 969 insertions(+), 133 deletions(-)

Thanks for working on this!

Do you see a way to reduce the code duplication needed across all
the action modules? I.e. that each of them now needs to register
a new per netns subsystem, etc. In other words, is there a way the
action API could be reworked to handle most of this in the tc core
framework instead?

Cheers,
Daniel