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.
The dnsmasq cache-size setting on EdgeOS could be re-generated anytime
by vyatta router/dhcp components. This conflicts with setting generated
by ctrld, causing dnsmasq fails to start.
It's better to keep dnsmasq cache enabled on EdgeOS, we can turn it off
again once we find a reliable way to control cache-size setting.
The postconf script added by ctrld requires all of these conditions to
work correctly:
- /proc, /tmp were mounted.
- dnsmasq is running.
Currently, ctrld is only waiting for NTP ready, which may not ensure
both of those conditions are true. Explicitly checking those conditions
is a safer approach.
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.
The default gateway is usually the DNS server in normal home network
setup for most users. However, there's case that it is not, causing
discover ptr failed.
This commit add discover_ptr_endpoints config parameter, so users can
define what DNS nameservers will be used.
Generating nextdns config must happen after stopping current ctrld
process. Otherwise, config processing may pick wrong IP+Port.
While at it, also making logging better when updating listener config:
- Change warn to info, prevent confusing that "something is wrong".
- Do not emit info when generating working default config, which may
cause duplicated messages printed.
So it won't spam ctrld log unnecessary, prevent confusion. While at it,
also change the log level from Warn to Info, since this error is not
actionable by the user.
A backoff with small max time will flood requests to Control D server,
causing false positive for abuse mitiation system. While a big max time
will cause ctrld not realize network change as fast as possible.
While at it, also sync DoH3 code with DoH code, ensuring no others place
can trigger requests flooding for ipv6 probing.
