From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Lunn Subject: Re: [PATCH net-next 1/2] net: bridge: add support for user-controlled bool options Date: Thu, 22 Nov 2018 16:35:00 +0100 Message-ID: <20181122153500.GF15403@lunn.ch> References: <20181122042925.8878-1-nikolay@cumulusnetworks.com> <20181122042925.8878-2-nikolay@cumulusnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, roopa@cumulusnetworks.com, davem@davemloft.net, bridge@lists.linux-foundation.org To: Nikolay Aleksandrov Return-path: Received: from vps0.lunn.ch ([185.16.172.187]:45741 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391723AbeKWCOz (ORCPT ); Thu, 22 Nov 2018 21:14:55 -0500 Content-Disposition: inline In-Reply-To: <20181122042925.8878-2-nikolay@cumulusnetworks.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Nov 22, 2018 at 06:29:24AM +0200, Nikolay Aleksandrov wrote: > We have been adding many new bridge options, a big number of which are > boolean but still take up netlink attribute ids and waste space in the skb. > Recently we discussed learning from link-local packets[1] and decided > yet another new boolean option will be needed, thus introducing this API > to save some bridge nl space. > The API supports changing the value of multiple boolean options at once > via the br_boolopt_multi struct which has an optmask (which options to > set, bit per opt) and optval (options' new values). Future boolean > options will only be added to the br_boolopt_id enum and then will have > to be handled in br_boolopt_toggle/get. The API will automatically > add the ability to change and export them via netlink, sysfs can use the > single boolopt function versions to do the same. The behaviour with > failing/succeeding is the same as with normal netlink option changing. > > If an option requires mapping to internal kernel flag or needs special > configuration to be enabled then it should be handled in > br_boolopt_toggle. It should also be able to retrieve an option's current > state via br_boolopt_get. > > [1] https://www.spinics.net/lists/netdev/msg532698.html > > Signed-off-by: Nikolay Aleksandrov > --- > include/uapi/linux/if_bridge.h | 18 +++++++++ > include/uapi/linux/if_link.h | 1 + > net/bridge/br.c | 68 ++++++++++++++++++++++++++++++++++ > net/bridge/br_netlink.c | 17 ++++++++- > net/bridge/br_private.h | 6 +++ > net/core/rtnetlink.c | 2 +- > 6 files changed, 110 insertions(+), 2 deletions(-) > > diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h > index e41eda3c71f1..6dc02c03bdf8 100644 > --- a/include/uapi/linux/if_bridge.h > +++ b/include/uapi/linux/if_bridge.h > @@ -292,4 +292,22 @@ struct br_mcast_stats { > __u64 mcast_bytes[BR_MCAST_DIR_SIZE]; > __u64 mcast_packets[BR_MCAST_DIR_SIZE]; > }; > + > +/* bridge boolean options > + * IMPORTANT: if adding a new option do not forget to handle > + * it in br_boolopt_toggle/get and bridge sysfs > + */ > +enum br_boolopt_id { > + BR_BOOLOPT_MAX > +}; > + > +/* struct br_boolopt_multi - change multiple bridge boolean options > + * > + * @optval: new option values (bit per option) > + * @optmask: options to change (bit per option) > + */ > +struct br_boolopt_multi { > + __u32 optval; > + __u32 optmask; > +}; Hi Nikolay Thanks for handling this. How many boolean options do we already have? What it the likelihood a u32 is going to be too small, in a couple of years time? I recently went through the pain of converting the u32 for representing link modes in the phylib API to a linux bitmap. I'm just wondering if in the long run, using a linux bitmap right from the beginning would be better? > +int br_boolopt_multi_toggle(struct net_bridge *br, > + struct br_boolopt_multi *bm) > +{ > + unsigned long bitmap = bm->optmask; > + int err = 0; > + int opt_id; > + > + for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) { > + bool on = !!(bm->optval & BIT(opt_id)); > + > + err = br_boolopt_toggle(br, opt_id, on); > + if (err) { > + br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n", > + opt_id, br_boolopt_get(br, opt_id), on, err); Would it be possible to return that to userspace using the extended error infrastructure? Andrew