Improvements
XDP is added to implement Read-Only mode
Demo video
Lab schema: there are two wireshark sessions on the interfaces before (on the left side) and after (on the right side) XDP filter.
This examples shows that 8.8.8.8 prefix was redistributed on Watcher and added into its announcement, but it was dropped by XDP and eventually didn't reach the network.
The same logic is applied on Database Description messages
and for extra stub networks in LSA1 Update
To check XDP logs, run
sudo cat /sys/kernel/debug/tracing/trace_pipe
To check whether XDP filter is assigned on the interface, run
ubuntu20:~/ospfwatcher$ ip l show dev it-vhost1025
178: it-vhost1025@if177: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp qdisc noqueue state UP mode DEFAULT group default
link/ether aa:c1:ab:e3:cb:d9 brd ff:ff:ff:ff:ff:ff link-netnsid 0
prog/xdp id 153 <-- !!!