1.9 KiB
This code was taken from VPP's src/plugins/linux-cp/ directory, originally by: Signed-off-by: Neale Ranns nranns@cisco.com Signed-off-by: Matthew Smith mgsmith@netgate.com Signed-off-by: Jon Loeliger jdl@netgate.com Signed-off-by: Pim van Pelt pim@ipng.nl Signed-off-by: Neale Ranns neale@graphiant.com
See previous work: https://gerrit.fd.io/r/c/vpp/+/30759 (interface mirroring) https://gerrit.fd.io/r/c/vpp/+/31122 (netlink listener)
It's intended to be re-submitted for review as a cleanup/rewrite of the existing Linux CP interface mirror and netlink syncer.
FAQ
Why doesn't the plugin listen to new linux interfaces?
Consider the following two commands:
ip link add link e0 name foo type vlan id 10 protocol 802.1ad
ip link add link foo name bar type vlan id 20
The two effectively create a dot1ad with an outer tag of 10 and an inner tag of
20 (you could also read this as e0.10.20). The foo interface is the untagged
VLAN 10 on e0 with ethernet type 0x8aa8, and the bar interface carries any
tagged traffic on foo, thus is ethernet type 0x8100 within the e0's ethernet
type 0x8aa8 outer frame.
It's easy to listen to netlink messages like these, but their name will in
no way be easy to map to a VPP subinterface concept. In VPP, all subinterfaces
are numbered on their phy, such as TenGigabitEthernet0/0/0.1000. It is not
clear how to map the linux host interface name foo and bar to this
numbering scheme in a way that doesn't create collissions.
A second consideration is that these QinQ interfaces can be 802.1ad or 802.1q
tagged on the outer. So what happens if after the above, a new foo2 interface
is created with protocol 802.1q ? VPP only allows sub interfaces to carry one
(1) number.
Rather than applying heuristics and adding bugs, it is not possible to create VPP interfaces via Linux, only the other way around. Create any L3 capable interface or subinterface in VPP, and it'll be created in Linux as well.