When sending a ping from the CLI, only accept a pong that is in reply
to the specific CLI ping we sent.
Updates #311
Signed-off-by: Val <valerie@tailscale.com>
This adds the capability to pad disco ping message payloads to reach a
specified size. It also plumbs it through to the tailscale ping -size
flag.
Disco pings used for actual endpoint discovery do not use this yet.
Updates #311.
Signed-off-by: salman <salman@tailscale.com>
Co-authored-by: Val <valerie@tailscale.com>
