os.IsNotExist doesn't unwrap errors. errors.Is does.
The ioutil.ReadFile ones happened to be fine but I changed them so
we're consistent with the rule: if the error comes from os, you can
use os.IsNotExist, but from any other package, use errors.Is.
(errors.Is always would also work, but not worth updating all the code)
The motivation here was that we were logging about failure to migrate
legacy relay node prefs file on startup, even though the code tried
to avoid that.
See golang/go#41122
Amazingly, there doesn't seem to be a documented way of updating network
configuration programmatically in a way that Windows takes notice of.
The naturopathic remedy for this is to invoke ipconfig /registerdns, which
does a variety of harmless things and also invokes the private API that
tells windows to notice new adapter settings. This makes our DNS config
changes stick within a few seconds of us setting them.
If we're invoking a shell command anyway, why futz with the registry at
all? Because netsh has no command for changing the DNS suffix list, and
its commands for setting resolvers requires parsing its output and
keeping track of which server is in what index. Amazingly, twiddling
the registry directly is the less painful option.
Fixes#853.
Signed-off-by: David Anderson <danderson@tailscale.com>
Updating the Windows firewall is usually reasonably fast, but
sometimes blocks for 20 seconds, 4 minutes, etc. Not sure why.
Until we understand that's happening, configure it in the background
without blocking the normal control flow.
Updates #785
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The RusagePrefixLog is rarely useful, hasn't been useful in a long
time, is rarely the measurement we need, and is pretty spammy (and
syscall-heavy). Disable it by default. We can enable it when we're
debugging memory.
At startup the client doesn't yet have the DERP map so can't do STUN
queries against DERP servers, so it only knows it local interface
addresses, not its STUN-mapped addresses.
We were reporting the interface-local addresses to control, getting
the DERP map, and then immediately reporting the full set of
updates. That was an extra HTTP request to control, but worse: it was
an extra broadcast from control out to all the peers in the network.
Now, skip the initial update if there are no stun results and we don't
have a DERP map.
More work remains optimizing start-up requests/map updates, but this
is a start.
Updates tailscale/corp#557
There was a bug with the lazy wireguard config code where, if the
minimum set of peers to tell wireguard didn't change, we skipped
calling userspaceEngine.updateActivityMapsLocked which updated
the various data structures that matched incoming traffic to later
reconfigure the minimum config.
That meant if an idle peer restarted and changed discovery keys, we
skipped updating our maps of disco keys/IPs that would caused us to
lazily inflate the config for that peer later if/when it did send
traffic.
Use golang.zx2c4.com/wireguard/windows/tunnel/winipcfg
instead of github.com/tailscale/winipcfg-go package.
Updates #760
Signed-off-by: Alex Brainman <alex.brainman@gmail.com>
Due to a copy/paste-o, we were monitoring address changes twice, and
not monitoring route changes at all.
Verified with 'tailscale debug --monitor' that this actually works now (while
running 'route add 10.3.0.0 mask 255.255.0.0 10.0.0.1' and 'route delete (same)'
back and forth in cmd.exe)
In practice route changes are accompanied by address changes and this
doesn't fix any known issues. I just noticed this while reading this
code again. But at least the code does what it was trying to do now.
This function is only called in fake mode, which won't do anything more
with the packet after we respond to it anyway, so dropping it in the
prefilter is not necessary. And it's kinda semantically wrong: we did
not reject it, so telling the upper layer that it was rejected produces
an ugly error message.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
At some point faketun got implemented as a loopback (put a packet in
from wireguard, the same packet goes back to wireguard) which is not
useful. It's supposed to be an interface that just sinks all packets,
and then wgengine adds *only* and ICMP Echo responder as a layer on
top.
This caused extremely odd bugs on darwin, where the special case that
reinjects packets from local->local was filling the loopback channel
and creating an infinite loop (which became jammed since the reader and
writer were in the same goroutine).
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
If no interfaces are up, calm down and stop spamming so much. It was
noticed as especially bad on Windows, but probably was bad
everywhere. I just have the best network conditions testing on a
Windows VM.
Updates #604
Gracefully skips touching the v6 NAT table on systems that don't have
it, and doesn't configure IPv6 at all if IPv6 is globally disabled.
Signed-off-by: David Anderson <danderson@tailscale.com>
When the network link changes, existing UDP sockets fail immediately
and permanently on macOS.
The forwarder set up a single UDP conn and never changed it.
As a result, any time there was a network link change,
all forwarded DNS queries failed.
To fix this, create a new connection when send requests
fail because of network unreachability.
This change is darwin-only, although extended it to other platforms
should be straightforward.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
While we're here, parseQuery into a plain function.
This is helpful for fuzzing. (Which I did a bit of. Didn't find anything.)
And clean up a few minor things.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Part of unforking our winipcfg-go and using upstream (#760), move our
additions into our repo. (We might upstream them later if upstream has
interest)
Originally these were:
@apenwarr: "Add ifc.SyncAddresses() and SyncRoutes()."
609dcf2df5
@bradfitz: "winipcfg: make Interface.AddRoutes do as much as possible, return combined error"
e9f93d53f3
@bradfitz: "prevent unnecessary Interface.SyncAddresses work; normalize IPNets in deltaNets"
decb9ee8e1
Might fix it. I've spent too much time failing to reproduce the issue. This doesn't
seem to make it worse, though (it still runs for me), so I'll include this and
see if it helps others while I still work on a reliable way to reproduce it.
Updates tailscale/corp#474
Otherwise when PAC server is down, we log, and each log entry is a new
HTTP request (from logtail) and a new GetProxyForURL call, which again
logs, non-stop. This is also nicer to the WinHTTP service.
Then also hook up link change notifications to the cache to reset it
if there's a chance the network might work sooner.
This change is to restore /etc/resolv.conf after tailscale down is called. This is done by setting the dns.Manager before errors occur. Error collection is also added.
Fixes#723
* wgengine/router/router_linux.go: Switched `cidrDiff("addr")` and `cidrDiff("route")` order
Signed-off-by: Christina Wen <christina@tailscale.com>
Co-authored-by: Christina Wen <christina@tailscale.com>
Also remove rebinding logic from the windows router. Magicsock will
instead rebind based on link change signals.
Signed-off-by: David Anderson <danderson@tailscale.com>
Updates #654. See that issue for a discussion of why
this timeout reduces flakiness, and what next steps are.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
