Currently, comments in resolv.conf cause our parser to fail,
with error messages like:
ParseIP("192.168.0.100 # comment"): unexpected character (at " # comment")
Fix that.
Noticed while looking through logs.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
When this happens, it is incredibly noisy in the logs.
It accounts for about a third of all remaining
"unexpected" log lines from a recent investigation.
It's not clear that we know how to fix this,
we have a functioning workaround,
and we now have a (cheap and efficient) metric for this
that we can use for measurements.
So reduce the logging to approximately once per minute.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
One of the most common "unexpected" log lines is:
"network state changed, but stringification didn't"
One way that this can occur is if an interesting interface
(non-Tailscale, has interesting IP address)
gains or loses an uninteresting IP address (link local or loopback).
The fact that the interface is interesting is enough for EqualFiltered
to inspect it. The fact that an IP address changed is enough for
EqualFiltered to declare that the interfaces are not equal.
But the State.String method reasonably declines to print any
uninteresting IP addresses. As a result, the network state appears
to have changed, but the stringification did not.
The String method is correct; nothing interesting happened.
This change fixes this by adding an IP address filter to EqualFiltered
in addition to the interface filter. This lets the network monitor
ignore the addition/removal of uninteresting IP addresses.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
The Windows BOOL type is an int32. We were using a bool,
which is a one byte wide. This could be responsible for the
ERROR_INVALID_PARAMETER errors we were seeing for calls to
WinHttpGetProxyForUrl.
We manually checked all other existing Windows syscalls
for similar mistakes and did not find any.
Updates #879
Co-authored-by: Aaron Klotz <aaron@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
There are lots of lines in the logs of the form:
portmapper: unexpected PMP probe response: {OpCode:128 ResultCode:3
SecondsSinceEpoch:NNN MappingValidSeconds:0 InternalPort:0
ExternalPort:0 PublicAddr:0.0.0.0}
ResultCode 3 here means a network failure, e.g. the NAT box itself has
not obtained a DHCP lease. This is not an indication that something
is wrong in the Tailscale client, so use different wording here
to reflect that. Keep logging, so that we can analyze and debug
the reasons that PMP probes fail.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Lets the systemd-resolved OSConfigurator report health changes
for out of band config resyncs.
Updates #3327
Signed-off-by: David Anderson <danderson@tailscale.com>
Don't set all the *.arpa. reverse DNS lookup domains if systemd-resolved
is old and can't handle them.
Fixes#3188
Change-Id: I283f8ce174daa8f0a972ac7bfafb6ff393dde41d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
There are a few remaining uses of testing.AllocsPerRun:
Two in which we only log the number of allocations,
and one in which dynamically calculate the allocations
target based on a different AllocsPerRun run.
This also allows us to tighten the "no allocs"
test in wgengine/filter.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Now that we multicast the SSDP query, we can get IGD offers from
devices other than the current device's default gateway. We don't want
to accidentally bind ourselves to those.
Updates #3197
Signed-off-by: David Anderson <danderson@tailscale.com>
And the derper change to add a CORS endpoint for latency measurement.
And a little magicsock change to cut down some log spam on js/wasm.
Updates #3157
Change-Id: I5fd9e6f5098c815116ddc8ac90cbcd0602098a48
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
There are /etc/resolv.conf files out there where resolvconf wrote
the file but pointed to systemd-resolved as the nameserver.
We're better off handling those as systemd-resolved.
> # Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
> # DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
> # 127.0.0.53 is the systemd-resolved stub resolver.
> # run "systemd-resolve --status" to see details about the actual nameservers.
Fixes https://github.com/tailscale/tailscale/issues/3026
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
In some containers, /etc/resolv.conf is a bind-mount from outside the container.
This prevents renaming to or from /etc/resolv.conf, because it's on a different
filesystem from linux's perspective. It also prevents removing /etc/resolv.conf,
because doing so would break the bind-mount.
If we find ourselves within this environment, fall back to using copy+delete when
renaming to /etc/resolv.conf, and copy+truncate when renaming from /etc/resolv.conf.
Fixes#3000
Co-authored-by: Denton Gentry <dgentry@tailscale.com>
Signed-off-by: David Anderson <danderson@tailscale.com>
The "go generate" command blindly looks for "//go:generate" anywhere
in the file regardless of whether it is truly a comment.
Prevent this false positive in cloner.go by mangling the string
to look less like "//go:generate".
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
When a DNS server claims to be unable or unwilling to handle a request,
instead of passing that refusal along to the client, just treat it as
any other error trying to connect to the DNS server. This prevents DNS
requests from failing based on if a server can respond with a transient
error before another server is able to give an actual response. DNS
requests only failing *sometimes* is really hard to find the cause of
(#1033).
Signed-off-by: Smitty <me@smitop.com>
"skipping portmap; gateway range likely lacks support" is really
spammy on cloud systems, and not very useful in debugging.
Fixes https://github.com/tailscale/tailscale/issues/3034
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
We added the initial handling only for macOS and iOS.
With 1.16.0 now released, suppress forwarding DNS-SD
on all platforms to test it through the 1.17.x cycle.
Updates #2442
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
On iOS (and possibly other platforms), sometimes our UDP socket would
get stuck in a state where it was bound to an invalid interface (or no
interface) after a network reconfiguration. We can detect this by
actually checking the error codes from sending our STUN packets.
If we completely fail to send any STUN packets, we know something is
very broken. So on the next STUN attempt, let's rebind the UDP socket
to try to correct any problems.
This fixes a problem where iOS would sometimes get stuck using DERP
instead of direct connections until the backend was restarted.
Fixes#2994
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
I forgot to include this file in the earlier
7cf8ec8108 commit.
This exists purely to keep "go mod tidy" happy.
Updates #1609
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We still try the host's x509 roots first, but if that fails (like if
the host is old), we fall back to using LetsEncrypt's root and
retrying with that.
tlsdial was used in the three main places: logs, control, DERP. But it
was missing in dnsfallback. So added it there too, so we can run fine
now on a machine with no DNS config and no root CAs configured.
Also, move SSLKEYLOGFILE support out of DERP. tlsdial is the logical place
for that support.
Fixes#1609
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
DNSSEC is an availability issue, as recently demonstrated by the
Slack issue, with limited security advantage. DoH on the other hand
is a critical security upgrade. This change adds DoH support for the
non-DNSSEC endpoints of Quad9.
https://www.quad9.net/service/service-addresses-and-features#unsec
Signed-off-by: Filippo Valsorda <hi@filippo.io>
It was in the wrong filter direction before, per CPU profiles
we now have.
Updates #1526 (maybe fixes? time will tell)
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Windows has a public dns.Flush used in router_windows.go.
However that won't work for platforms like Linux, where
we need a different flush mechanism for resolved versus
other implementations.
We're instead adding a FlushCaches method to the dns Manager,
which can be made to work on all platforms as needed.
Fixes https://github.com/tailscale/tailscale/issues/2132
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
The earlier 382b349c54 was too late,
as engine creation itself needed to listen on things.
Fixes#2827
Updates #2822
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We currently plumb full URLs for DNS resolvers from the control server
down to the client. But when we pass the values into the net/dns
package, we throw away any URL that isn't a bare IP. This commit
continues the plumbing, and gets the URL all the way to the built in
forwarder. (It stops before plumbing URLs into the OS configurations
that can handle them.)
For #2596
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
Reported on IRC: in an edge case, you can end up with a directManager DNS
manager and --accept-dns=false, in which case we should do nothing, but
actually end up restarting resolved whenever the netmap changes, even though
the user told us to not manage DNS.
Signed-off-by: David Anderson <danderson@tailscale.com>
Reported on IRC: a resolv.conf that contained two entries for
"nameserver 127.0.0.53", which defeated our "is resolved actually
in charge" check. Relax that check to allow any number of nameservers,
as long as they're all 127.0.0.53.
Signed-off-by: David Anderson <danderson@tailscale.com>
It wasn't using the right metric. Apparently you're supposed to sum the route
metric and interface metric. Whoops.
While here, optimize a few little things too, not that this code
should be too hot.
Fixes#2707 (at least; probably dups but I'm failing to find)
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Now that we have the easier-to-parse go:build build tags,
it is straightforward to simplify them. Yay.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Mostly so the Linux one can use Linux-specific stuff in package
syscall and not use os/exec for uname for portability.
But also it helps deps a tiny bit on iOS.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This logs some basic statistics for UPnP, so that tailscale can better understand what routers
are being used and how to connect to them.
Signed-off-by: julianknodt <julianknodt@gmail.com>
This adds a PCP test to the IGD test server, by hardcoding in a few observed packets from
Denton's box.
Signed-off-by: julianknodt <julianknodt@gmail.com>
And use dynamic port numbers in tests, as Linux on GitHub Actions and
Windows in general have things running on these ports.
Co-Author: Julian Knodt <julianknodt@gmail.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Previously, we hashed the question and combined it with the original
txid which was useful when concurrent queries were multiplexed on a
single local source port. We encountered some situations where the DNS
server canonicalizes the question in the response (uppercase converted
to lowercase in this case), which resulted in responses that we couldn't
match to the original request due to hash mismatches. This includes a
new test to cover that situation.
Fixes#2597
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
PCP handles external IPs by allowing the client to specify them in the packet, which is more
explicit than requiring 2 packets from PMP, so allow for future changes to add it in easily.
Signed-off-by: julianknodt <julianknodt@gmail.com>
