[PATCH net-next v2 0/2] br_netfilter: enable in non-initial netns

From: Christian Brauner
Date: Mon Jun 10 2019 - 17:30:38 EST

Hey everyone,

/* v2 */
Split into two patches (cf. [4]):
1/2: replace #define with static inline helpers
2/2: namespace syscals

/* v1 */
This is a rework of the patch to not touch struct net at all and instead
rely on the pernet infrastructure directly to namespace the sysctls.

/* v0 */
This is another resend of the same patch series. I have received so many
requests, pings, and questions that I would really like to push for this

Over time I have seen multiple reports by users who want to run applications
(Kubernetes e.g. via [1]) that require the br_netfilter module in
non-initial network namespaces. There are *a lot* of issues for this. A
shortlist including ChromeOS and other big users is found below under
[2]! Even non-devs already tried to get more traction on this by
commenting on the patchset (cf. [3]).

Currently, the /proc/sys/net/bridge folder is only created in the
initial network namespace. This patch series ensures that the
/proc/sys/net/bridge folder is available in each network namespace if
the module is loaded and disappears from all network namespaces when the
module is unloaded.
The patch series also makes the sysctls:


apply per network namespace. This unblocks some use-cases where users
would like to e.g. not do bridge filtering for bridges in a specific
network namespace while doing so for bridges located in another network
The netfilter rules are afaict already per network namespace so it
should be safe for users to specify whether a bridge device inside their
network namespace is supposed to go through iptables et al. or not.
Also, this can already be done by setting an option for each individual
bridge via Netlink. It should also be possible to do this for all
bridges in a network namespace via sysctls.


[1]: https://github.com/zimmertr/Bootstrap-Kubernetes-with-Ansible
[2]: https://bugs.chromium.org/p/chromium/issues/detail?id=878034
[3]: https://lkml.org/lkml/2019/3/7/365
[4]: 20190610174136.p3fbcbn33en5bb7f@salvia/">https://lore.kernel.org/lkml/20190610174136.p3fbcbn33en5bb7f@salvia/

Christian Brauner (2):
br_netfilter: port sysctls to use brnf_net
br_netfilter: namespace bridge netfilter sysctls

include/net/netfilter/br_netfilter.h | 3 +-
net/bridge/br_netfilter_hooks.c | 245 +++++++++++++++++----------
net/bridge/br_netfilter_ipv6.c | 2 +-
3 files changed, 162 insertions(+), 88 deletions(-)