Exit node traffic is aggregated to protect the privacy
of those using an exit node. However, it is reasonable to
at least log which nodes are making most use of an exit node.
For a node using an exit node,
the source will be the taiscale IP address of itself,
while the destination will be zeroed out.
For a node that serves as an exit node,
the source will be zeroed out,
while the destination will be tailscale IP address
of the node that initiated the exit traffic.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2327c6b05f