* tailcfg, control/controlhttp, control/controlclient: add ControlDialPlan field
This field allows the control server to provide explicit information
about how to connect to it; useful if the client's link status can
change after the initial connection, or if the DNS settings pushed by
the control server break future connections.
Change-Id: I720afe6289ec27d40a41b3dcb310ec45bd7e5f3e
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
As the comment in the code says, netstack should always respond to ICMP
echo requests to a 4via6 address, even if the netstack instance isn't
normally processing subnet traffic.
Follow-up to #5709
Change-Id: I504d0776c5824071b2a2e0e687bc33e24f6c4746
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
This doesn't change any behaviour for now, other than maybe running a
full netcheck more often. The intent is to start gathering data on
captive portals, and additionally, seeing this in the 'tailscale
netcheck' command should provide a bit of additional information to
users.
Updates #1634
Change-Id: I6ba08f9c584dc0200619fa97f9fde1a319f25c76
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
This turns 'dialParams' into something more like net.Dialer, where
configuration fields are public on the struct.
Split out of #5648
Change-Id: I0c56fd151dc5489c3c94fb40d18fd639e06473bc
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
If we accept a forwarded TCP connection before dialing, we can
erroneously signal to a client that we support IPv6 (or IPv4) without
that actually being possible. Instead, we only complete the client's TCP
handshake after we've dialed the outbound connection; if that fails, we
respond with a RST.
Updates #5425 (maybe fixes!)
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
In addition to printing goroutine stacks, explicitly track all in-flight
operations and print them when the watchdog triggers (along with the
time they were started at). This should make debugging watchdog failures
easier, since we can look at the longest-running operation(s) first.
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Prior to this change, if BIRD stops responding wgengine.watchdogEngine
will crash tailscaled.
This happens because in wgengine.userspaceEngine, we end up blocking
forever trying to write a request to or read a response from BIRD with
wgLock held, and then future watchdog'd calls will block on acquiring
that mutex until the watchdog kills the process. With the timeout, we at
least get the chance to print an error message and decide whether we
want to crash or not.
Updates tailscale/coral#72
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Andrew DunhamandGitHub