Adds `ZEROTIER_ONE_GATEWAY_MODE` variable. Supported values are
`inbound` (forward traffic from ZeroTier cloud to local interfaces),
`outbound` (forward traffic from local interfaces to ZeroTier cloud)
and `both` (bi-directional). Defaults to `inbound`.
Also checks for `net.ipv4.ip_forward=1`. If not enabled, falls back
to standard client mode.
Signed-off-by: Phill Kelley <34226495+Paraphraser@users.noreply.github.com>
than one network can be specified as defaults.
First cut at improved launch/tear-down so iptables entries do not get
duplicated, especially if the zerotier daemon quits because networking
has not come up properly after a reboot.
Signed-off-by: Phill Kelley <34226495+Paraphraser@users.noreply.github.com>
