Re: [PATCH net-next] net/hanic: Add the hanic network interface for high availability links

Jiri Pirko
2022-11-22T14:08:15Z

Tue, Nov 22, 2022 at 02:55:29PM CET, olteanv@gmail.com wrote:
>Hi Jiri,
>
>On Tue, Nov 22, 2022 at 01:49:38PM +0100, Jiri Pirko wrote:
>> Sat, Nov 19, 2022 at 12:26:39AM CET, steve.williams@getcruise.com wrote:
>> >This is a virtual device that implements support for 802.1cb R-TAGS
>> >and duplication and deduplication. The hanic nic itself is not a device,
>> >but enlists ethernet nics to act as parties in a high-availability
>> >link. Outbound packets are duplicated and tagged with R-TAGs, then
>> >set out the enlisted links. Inbound packets with R-TAGs have their
>> >R-TAGs removed, and duplicates are dropped to complete the link. The
>> >algorithm handles links being completely disconnected, sporadic packet
>> >loss, and out-of-order arrivals.
>> >
>> >To the extent possible, the link is self-configuring: It detects and
>> >brings up streams as R-TAG'ed packets are detected, and creates streams
>> >for outbound packets unless explicitly filtered to skip tagging.
>> >---
>> > Documentation/networking/hanic.rst | 351 ++++++++++
>> > Documentation/networking/index.rst | 1 +
>> > MAINTAINERS | 6 +
>> > drivers/net/Kconfig | 17 +
>> > drivers/net/Makefile | 1 +
>> > drivers/net/hanic/Makefile | 15 +
>> > drivers/net/hanic/hanic_dev.c | 1006 ++++++++++++++++++++++++++++
>> > drivers/net/hanic/hanic_filter.c | 172 +++++
>> > drivers/net/hanic/hanic_main.c | 109 +++
>> > drivers/net/hanic/hanic_netns.c | 58 ++
>> > drivers/net/hanic/hanic_priv.h | 408 +++++++++++
>> > drivers/net/hanic/hanic_protocol.c | 350 ++++++++++
>> > drivers/net/hanic/hanic_streams.c | 161 +++++
>> > drivers/net/hanic/hanic_sysfs.c | 672 +++++++++++++++++++
>> > 14 files changed, 3327 insertions(+)
>>
>> Leaving aside issues I spotted looking at random parts of the code (like
>> checking if kernel version is >5 :O), why this has to be another
>> master-slave device? From the first look, I think this could be
>> implemented as a bond/team mode. You would save a lot of plumbing code
>> and ease up the maintainance burden. Did you consider that option?
>> Any particular arguments against that approach?
>
>Neither bond nor team have forwarding between ports built in, right?
>Forwarding is pretty fundamental to 802.1CB (at least to the use cases
>I know of).

I don't see any forwarding in this patch. How is it supposed to be
working, I wonder...