Messages in this thread | | | Date | Mon, 22 Aug 2022 09:49:28 +0200 | From | netdev@kapio-te ... | Subject | Re: [PATCH v4 net-next 3/6] drivers: net: dsa: add locked fdb entry flag to drivers |
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On 2022-08-22 07:40, Ido Schimmel wrote: > On Sun, Aug 21, 2022 at 03:43:04PM +0200, netdev@kapio-technology.com > wrote: > > I personally think that the mv88e6xxx semantics are very weird (e.g., > no > roaming, traffic blackhole) and I don't want them to determine how the > feature works in the pure software bridge or other hardware > implementations. On the other hand, I understand your constraints and I > don't want to create a situation where user space is unable to > understand how the data path works from the bridge FDB dump with > mv88e6xxx. > > My suggestion is to have mv88e6xxx report the "locked" entry to the > bridge driver with additional flags that describe its behavior in terms > of roaming, ageing and forwarding. > > In terms of roaming, since in mv88e6xxx the entry can't roam you should > report the entry with the "sticky" flag.
As I am not familiar with roaming in this context, I need to know how the SW bridge should behave in this case. In this I am assuming that roaming is regarding unauthorized entries. In this case, is the roaming only between locked ports or does the roaming include that the entry can move to a unlocked port, resulting in the locked flag getting removed?
> In terms of ageing, since > mv88e6xxx is the one doing the ageing and not the bridge driver, report > the entry with the "extern_learn" flag.
Just for the record, I see that entries coming from the driver to the bridge will always have the "extern learn" flag set as can be seen from the SWITCHDEV_FDB_ADD_TO_BRIDGE events handling in br_switchdev_event() in br.c, which I think is the correct behavior.
> In terms of forwarding, in > mv88e6xxx the entry discards all matching packets. We can introduce a > new FDB flag that instructs the entry to silently discard all matching > packets. Like we have with blackhole routes and nexthops.
Any suggestions to the name of this flag?
> > I believe that the above suggestion allows you to fully describe how > these entries work in mv88e6xxx while keeping the bridge driver in sync > with complete visibility towards user space. > > It also frees the pure software implementation from the constraints of > mv88e6xxx, allowing "locked" entries to behave like any other > dynamically learned entries modulo the fact that they cannot "unlock" a > locked port. > > Yes, it does mean that user space will get a bit different behavior > with > mv88e6xxx compared to a pure software solution, but a) It's only the > corner cases that act a bit differently. As a whole, the feature works > largely the same. b) User space has complete visibility to understand > the behavior of the offloaded data path. >
>> >> I will change it in iproute2 to: >> bridge link set dev DEV mab on|off > > And s/BR_PORT_MACAUTH/BR_PORT_MAB/ ?
Sure, I will do that. :-)
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