This commit implements probing of UDP path lifetime on the tail end of
an active direct connection. Probing configuration has two parts -
Cliffs, which are various timeout cliffs of interest, and
CycleCanStartEvery, which limits how often a probing cycle can start,
per-endpoint. Initially a statically defined default configuration will
be used. The default configuration has cliffs of 10s, 30s, and 60s,
with a CycleCanStartEvery of 24h. Probing results are communicated via
clientmetric counters. Probing is off by default, and can be enabled
via control knob. Probing is purely informational and does not yet
drive any magicsock behaviors.
Updates #540
Signed-off-by: Jordan Whited <jordan@tailscale.com>
The switch in Conn.runDerpReader() on the derp.ReceivedMessage type
contained cases other than derp.ReceivedPacket that fell through to
writing to c.derpRecvCh, which should only be reached for
derp.ReceivedPacket. This can result in the last/previous
derp.ReceivedPacket to be re-handled, effectively creating a duplicate
packet. If the last derp.ReceivedPacket happens to be a
disco.CallMeMaybe it may result in a disco ping scan towards the
originating peer on the endpoints contained.
The change in this commit moves the channel write on c.derpRecvCh and
subsequent select awaiting the result into the derp.ReceivedMessage
case, preventing it from being reached from any other case. Explicit
continue statements are also added to non-derp.ReceivedPacket cases
where they were missing, in order to signal intent to the reader.
Fixes#10586
Signed-off-by: Jordan Whited <jordan@tailscale.com>
In DERP homeless mode, a DERP home connection is not sought or
maintained and the local node is not reachable.
Updates #3363
Updates tailscale/corp#396
Change-Id: Ibc30488ac2e3cfe4810733b96c2c9f10a51b8331
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Previously two tsnet nodes in the same process couldn't have disjoint
sets of controlknob settings from control as both would overwrite each
other's global variables.
This plumbs a new controlknobs.Knobs type around everywhere and hangs
the knobs sent by control on that instead.
Updates #9351
Change-Id: I75338646d36813ed971b4ffad6f9a8b41ec91560
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If we don't have the ICMP hint available, such as on Android, we can use
the signal of rx traffic to bias toward a particular endpoint.
We don't want to stick to a particular endpoint for a very long time
without any signals, so the sticky time is reduced to 1 second, which is
large enough to avoid excessive packet reordering in the common case,
but should be small enough that either rx provides a strong signal, or
we rotate in a user-interactive schedule to another endpoint, improving
the feel of failover to other endpoints.
Updates #8999
Co-authored-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
Signed-off-by: James Tucker <james@tailscale.com>
Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
Now a nodeAttr: ForceBackgroundSTUN, DERPRoute, TrimWGConfig,
DisableSubnetsIfPAC, DisableUPnP.
Kept support for, but also now a NodeAttr: RandomizeClientPort.
Removed: SetForceBackgroundSTUN, SetRandomizeClientPort (both never
used, sadly... never got around to them. But nodeAttrs are better
anyway), EnableSilentDisco (will be a nodeAttr later when that effort
resumes).
Updates #8923
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
