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

Jiri Pirko
2022-11-22T12:49:46Z

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?

Thanks!