If the server is running old version of ctrld, the deactivation pin
check will return 404 not found, the client should consider this as no
error instead of returning invalid pin code.
This allows v1.3.5 binary `ctrld start` command while the ctrld server
is still running old version. I discover this while testing v1.3.5
binary on a router with old ctrld version running.
The loop is run after the main interface DNS was set, thus the error
would make noise to users. This commit removes the noise, by making
currentStaticDNS returns an additional error, so it's up to the caller
to decive whether to emit the error or not.
Further, the physical interface loop will now only log when the callback
function runs successfully. Emitting the callback error can be done in
the future, until we can figure out how to detect physical interfaces in
Go portably.
The save/restore DNS functionality always perform its job, even though
the DNS is not static, aka set by DHCP. That may lead to confusion to
users. Since DHCP settings was changed to static settings, even though
the namesers set are the same.
To fix this, ctrld should save/restore only there's actual static DNS
set. For DHCP, thing should work as-is like we are doing.
Windows Server which is running Active Directory will have its own DNS
server running. For typical setup, this DNS server will listen on all
interfaces, and receiving queries from others to be able to resolve
computer name in domain.
That would make ctrld default setup never works, since ctrld can listen
on port 53, but requests are never be routed to its listeners.
To integrate ctrld in this case, we need to listen on a local IP
address, then configure this IP as a Forwarder of local DNS server. With
this setup, computer name on domain can still be resolved, and other
queries can still be resolved by ctrld upstream as usual.
After installing as a system service, "ctrld start" does an end-to-end
test for ensuring DNS can be resolved correctly. However, in case the
system is mis-configured (by firewall, other softwares ...) and the test
query could not be sent to ctrld listener, the current error message is
not helpful, causing the confusion from users perspective.
To improve this, selfCheckStatus function now returns the actual status
and error during its process. The caller can now rely on the service
status and the error to produce more useful/friendly message to users.
In some old Windows systems, s.Uninstall does not remove the service
completely at the time s.Install was running, prevent ctrld from being
installed again.
Workaround this by attempting to uninstall ctrld several times, re-check
for service status after each attempt to ensure it was uninstalled.
Windows may raise WSAEHOSTUNREACH instead WSAENETUNREACH in case of
network not available when resuming from sleep or switching network, so
checkUpstream is never kicked in for this type of error.
To prevent duplicated running of checkUpstream function at the same
time, upstream monitor uses a boolean to report whether the upstream is
checking. If this boolean is true, then other calls after the first one
will be returned immediately.
However, checkUpstream does not set this boolean to false when it
finishes, thus all future calls to checkUpstream won't be run, causing
the upstream is marked as down forever.
Fixing this by ensuring the boolean is reset once checkUpstream done.
While at it, also guarding all upstream monitor operations with a mutex,
ensuring there's no race condition between marking upstream state.
We see number of failed test in Github Action, mostly on MacOS or
Windows due to the fact that goroutines are scheduled to be run
consequently.
This commit improves the test, ensuring at least 2 goroutines were
started before increasing the counting.
On some routers, change to network may trigger re-rendering
/etc/resolv.conf file, causing requests from router itself stop using
ctrld.
Fixing this by watching changes to /etc/resolv.conf, then revert them.
For Android devices, when it joins the network, it uses ctrld to resolve
its private DNS once and never reaches ctrld again. For each time, it uses
a different IPv6 address, which causes hundreds/thousands different client
IDs created for the same device, which is pointless.
