Implement rate limiting on log messages
Addresses issue #317, where logs can get spammed with the same message
nonstop. Created a rate limiting closure on logging functions, which
limits the number of messages being logged per second based on format
string. To keep memory usage as constant as possible, the previous cache
purging at periodic time intervals has been replaced by an LRU that
discards the oldest string when the capacity of the cache is reached.
Signed-off-by: Wendi Yu <wendi.yu@yahoo.ca>
Instead, pass in only exactly the relevant configuration pieces
that the OS network stack cares about.
Signed-off-by: David Anderson <danderson@tailscale.com>
New logic installs precise filters for subnet routes,
plays nice with other users of netfilter, and lays the
groundwork for fixing routing loops via policy routing.
Signed-off-by: David Anderson <danderson@tailscale.com>
If Australia's far away and not going to be used, it's still going to
be far away a minute later. No need to send backup
just-in-case-UDP-gets-lost STUN packets to the known far away
destinations. Those are the ones most likely to trigger retries due to
delay anyway (in random 50-250ms, currently). But we'll keep sending 1
packet to them, just in case our airplane landed.
Likewise, be less aggressive with IPv6. The main point is just to see
whether IPv6 works. No need to send up to 10 packets every round. Max
two is enough (except for the first round). This does mean our STUN
traffic graphs for IPv4-vs-IPv6 will change shape. Oh well. It was a
weird eyeball metric for IPv6 connectivity anyway and we have better
metrics.
We can tweak this policy over time. It's factored out and has tests
now.
No tidy, because it doesn't work for me:
$ go mod tidy
go: finding module for package tailscale.io/control
go: finding module for package tailscale.io/control/cfgdb
tailscale.com/control/controlclient tested by
tailscale.com/control/controlclient.test imports
tailscale.io/control: cannot find module providing package tailscale.io/control: unrecognized import path "tailscale.io/control": parse https://tailscale.io/control?go-get=1: no go-import meta tags (meta tag tailscale.com did not match import path tailscale.io/control)
tailscale.com/control/controlclient tested by
tailscale.com/control/controlclient.test imports
tailscale.io/control/cfgdb: cannot find module providing package tailscale.io/control/cfgdb: unrecognized import path "tailscale.io/control/cfgdb": parse https://tailscale.io/control/cfgdb?go-get=1: no go-import meta tags (meta tag tailscale.com did not match import path tailscale.io/control/cfgdb)
Signed-off-by: Elias Naur <mail@eliasnaur.com>
These will be used for dynamically changing the identity of a node, so
its ACL rights can be different from your own.
Note: Not all implemented yet on the server side, but we need this so
we can request the tagged rights in the first place.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
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>
This strictly sequences things such that c1 is fully registered in
the control server before c2 creates its poll. Failure to do this
can cause an inversion where c2's poll finishes establishing
before c1's poll starts, which results in c2 getting disconnected
rather than c1, and the test times out waiting for c1 to get kicked.
Fixes#98.
Signed-off-by: David Anderson <danderson@tailscale.com>
