Layer 2 Forwarding Enhancements

[anilkpandey]

Added code changes related to Layer 2 Forwarding Enhancement:

As part of L2 enhancements, per port, per vlan and per port-vlan fdb flush support has been added. The fdb flush response from SAI comes as individual mac delete as mentioned in the HLD. The change here is to follow the same way for VS as well.

Regarding SAI_FDB_EVENT_FLUSHED, it is handled in sync only for 'flush all' case and handling SAI_FDB_EVENT_FLUSHED for per port and per port-vlan will require hgetall on all fdb keys. So, individual mac delete response is preferred.

Another change is to move fdb handling to fdborch. As the fdb reference count is now maintained in fdborch as well, need to move the sai redis fdb handling also there to avoid the reference counts to go out of sync between the two.

[lguohan]

@anilkpandey , thanks for the enhancement. can you provide full description of the change?

[kcudnik]

of course this needs to be build/checked again after swss-common lua fix

[anilkpandey]

retest this please

[anilkpandey]

build passed. please merge.

[lguohan]

please remove .DS_Store

[anilkpandey]

please remove .DS_Store

Done.

[kcudnik]

@anilkpandey Hey, since you worked on this PR i want to ask about special case, since we are moving forward with supporting syncd multiple switch instances in the same process, then for example there can be possibility that we do a flush with no attributes, just for a single switch, then we want all fdb entries to be removed from that single switch, this is the case when port=0 and bv_id = 0, but your script (the one in swss-common fdb_flush.lua) will remove all the fdb entries from possible all switches.
To make this work, an extra param needs to be pushed and checked which is switchId, and cehcking each fdb_entry.switch_id in each entry, before actually making remove.
This switchId must be passed to the lua script and inside checked if fdb entry to be removed comes from that particular switch.
Ideally this swtich Id would need to be checked in other cases too (for example when bv_id is specified and non zero). Since we won't cross pass objects between switches (for example case when passing one bv_id from one switch to another is forbidden) to be extra sure, always switch Id should be checked.
Can you make an update to your script and submit PR ?

[anilkpandey]

Yes, I will create a PR for this change.

[kcudnik]

thanks !