This depends on improved support from the control server, to send the
new subnet width (Bits) fields. If these are missing, we fall back to
assuming their value is /32.
Conversely, if the server sends Bits fields to an older client, it will
interpret them as /32 addresses. Since the only rules we allow are
"accept" rules, this will be narrower or equal to the intended rule, so
older clients will simply reject hosts on the wider subnet (fail
closed).
With this change, the internal filter.Matches format has diverged
from the wire format used by controlclient, so move the wire format
into tailcfg and convert it to filter.Matches in controlclient.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
We were printing "Shields Up" when the netmap wasn't initialized yet,
which while technically effectively true, turned out to be confusing
when trying to debug things.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
Some programs use frequent short-duration backoffs even under non-error
conditions. They can set this to avoid logging short backoffs when
things are operating normally, but still get messages when longer
backoffs kick in.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
When shields are up, no services are available to connect to, so hide
them all. This will also help them disappear from the UI menu on
other nodes.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
This sets a default packet filter that blocks all incoming requests,
giving end users more control over who can get into their machine, even
if the admin hasn't set any central ACLs.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
Longer term, we should probably update the packet filter to be fully
stateful, for both TCP and ICMP. That is, only ICMP packets related to
a session *we* initiated should be allowed back in. But this is
reasonably secure for now, since wireguard is already trimming most
traffic. The current code would not protect against eg. Ping-of-Death style
attacks from VPN nodes.
Fixestailscale/tailscale#290.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
- Reset() was not including a Version field, so was getting rejected;
the Logout operation no longer happened when the client got disconnected.
- Don't crash if we can't decode 0-byte messages, which I suspect might
sometimes come through on EOF.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
Avery Pennarun