The callback itself is not removed as it is used in other repos, making
it simpler for those to slowly transition to the eventbus.
Updates #15160
Signed-off-by: Claus Lensbøl <claus@tailscale.com>
Saves 328 KB (2.5%) off the minimal binary.
For IoT devices that don't need MagicDNS (e.g. they don't make
outbound connections), this provides a knob to disable all the DNS
functionality.
Rather than a massive refactor today, this uses constant false values
as a deadcode sledgehammer, guided by shotizam to find the largest DNS
functions which survived deadcode.
A future refactor could make it so that the net/dns/resolver and
publicdns packages don't even show up in the import graph (along with
their imports) but really it's already pretty good looking with just
these consts, so it's not at the top of my list to refactor it more
soon.
Also do the same in a few places with the ACME (cert) functionality,
as I saw those while searching for DNS stuff.
Updates #12614
Change-Id: I8e459f595c2fde68ca16503ff61c8ab339871f97
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This is step 4 of making syspolicy a build-time feature.
This adds a policyclient.Get() accessor to return the correct
implementation to use: either the real one, or the no-op one. (A third
type, a static one for testing, also exists, so in general a
policyclient.Client should be plumbed around and not always fetched
via policyclient.Get whenever possible, especially if tests need to use
alternate syspolicy)
Updates #16998
Updates #12614
Change-Id: Iaf19670744a596d5918acfa744f5db4564272978
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
fixestailscale/corp#25612
We now keep track of any dns configurations which we could not
compile. This gives RecompileDNSConfig a configuration to
attempt to recompile and apply when the OS pokes us to indicate
that the interface dns servers have changed/updated. The manager config
will remain unset until we have the required information to compile
it correctly which should eliminate the problematic SERVFAIL
responses (especially on macOS 15).
This also removes the missingUpstreamRecovery func in the forwarder
which is no longer required now that we have proper error handling
and recovery manager and the client.
Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
updates tailscale/corp#27145
We require a means to trigger a recompilation of the DNS configuration
to pick up new nameservers for platforms where we blend the interface
nameservers from the OS into our DNS config.
Notably, on Darwin, the only API we have at our disposal will, in rare instances,
return a transient error when querying the interface nameservers on a link change if
they have not been set when we get the AF_ROUTE messages for the link
update.
There's a corresponding change in corp for Darwin clients, to track
the interface namservers during NEPathMonitor events, and call this
when the nameservers change.
This will also fix the slightly more obscure bug of changing nameservers
while tailscaled is running. That change can now be reflected in
magicDNS without having to stop the client.
Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
Importing the ~deprecated golang.org/x/exp/maps as "xmaps" to not
shadow the std "maps" was getting ugly.
And using slices.Collect on an iterator is verbose & allocates more.
So copy (x)maps.Keys+Values into our slicesx package instead.
Updates #cleanup
Updates #12912
Updates #14514 (pulled out of that change)
Change-Id: I5e68d12729934de93cf4a9cd87c367645f86123a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Updates tailscale/tailscale#13326
This PR begins implementing a `tailscale dns` command group in the Tailscale CLI. It provides an initial implementation of `tailscale dns status` which dumps the state of the internal DNS forwarder.
Two new endpoints were added in LocalAPI to support the CLI functionality:
- `/netmap`: dumps a copy of the last received network map (because the CLI shouldn't have to listen to the ipn bus for a copy)
- `/dns-osconfig`: dumps the OS DNS configuration (this will be very handy for the UI clients as well, as they currently do not display this information)
My plan is to implement other subcommands mentioned in tailscale/tailscale#13326, such as `query`, in later PRs.
Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
fixes tailscale#12968
The dns manager cleanup func was getting passed a nil
health tracker, which will panic. Fixed to pass it
the system health tracker.
Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
updates tailscale/corp#21823
Misconfigured, broken, or blocked DNS will often present as
"internet is broken'" to the end user. This plumbs the health tracker
into the dns manager and forwarder and adds a health warning
with a 5 second delay that is raised on failures in the forwarder and
lowered on successes.
Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
And some misc doc tweaks for idiomatic Go style.
Updates #cleanup
Change-Id: I3ca45f78aaca037f433538b847fd6a9571a2d918
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Fixestailscale/corp#20677
Replaces the original attempt to rectify this (by injecting a netMon
event) which was both heavy handed, and missed cases where the
netMon event was "minor".
On apple platforms, the fetching the interface's nameservers can
and does return an empty list in certain situations. Apple's API
in particular is very limiting here. The header hints at notifications
for dns changes which would let us react ahead of time, but it's all
private APIs.
To avoid remaining in the state where we end up with no
nameservers but we absolutely need them, we'll react
to a lack of upstream nameservers by attempting to re-query
the OS.
We'll rate limit this to space out the attempts. It seems relatively
harmless to attempt a reconfig every 5 seconds (triggered
by an incoming query) if the network is in this broken state.
Missing nameservers might possibly be a persistent condition
(vs a transient error), but that would also imply that something
out of our control is badly misconfigured.
Tested by randomly returning [] for the nameservers. When switching
between Wifi networks, or cell->wifi, this will randomly trigger
the bug, and we appear to reliably heal the DNS state.
Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
Without this rule, Windows 8.1 and newer devices issue parallel DNS requests to DNS servers
associated with all network adapters, even when "Override local DNS" is enabled and/or
a Mullvad exit node is being used, resulting in DNS leaks.
This also adds "disable-local-dns-override-via-nrpt" nodeAttr that can be used to disable
the new behavior if needed.
Fixestailscale/corp#20718
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Updates corp#15802.
Adds the ability for control to disable the recently added change that uses split DNS in more cases on iOS. This will allow us to disable the feature if it leads to regression in production. We plan to remove this knob once we've verified that the feature works properly.
Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
Updates https://github.com/tailscale/corp/issues/15802.
On iOS exclusively, this PR adds logic to use a split DNS configuration in more cases, with the goal of improving battery life. Acting as the global DNS resolver on iOS should be avoided, as it leads to frequent wakes of IPNExtension.
We try to determine if we can have Tailscale only handle DNS queries for resources inside the tailnet, that is, all routes in the DNS configuration do not require a custom resolver (this is the case for app connectors, for instance).
If so, we set all Routes as MatchDomains. This enables a split DNS configuration which will help preserve battery life. Effectively, for the average Tailscale user who only relies on MagicDNS to resolve *.ts.net domains, this means that Tailscale DNS will only be used for those domains.
This PR doesn't affect users with Override Local DNS enabled. For these users, there should be no difference and Tailscale will continue acting as a global DNS resolver.
Signed-off-by: Andrea Gottardo <andrea@tailscale.com>
The goal is to move more network state accessors to netmon.Monitor
where they can be cheaper/cached. But first (this change and others)
we need to make sure the one netmon.Monitor is plumbed everywhere.
Some notable bits:
* tsdial.NewDialer is added, taking a now-required netmon
* because a tsdial.Dialer always has a netmon, anything taking both
a Dialer and a NetMon is now redundant; take only the Dialer and
get the NetMon from that if/when needed.
* netmon.NewStatic is added, primarily for tests
Updates tailscale/corp#10910
Updates tailscale/corp#18960
Updates #7967
Updates #3299
Change-Id: I877f9cb87618c4eb037cee098241d18da9c01691
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This moves most of the health package global variables to a new
`health.Tracker` type.
But then rather than plumbing the Tracker in tsd.System everywhere,
this only goes halfway and makes one new global Tracker
(`health.Global`) that all the existing callers now use.
A future change will eliminate that global.
Updates #11874
Updates #4136
Change-Id: I6ee27e0b2e35f68cb38fecdb3b2dc4c3f2e09d68
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This removes a potentially increased boot delay for certain boot
topologies where they block on ExecStartPre that may have socket
activation dependencies on other system services (such as
systemd-resolved and NetworkManager).
Also rename cleanup to clean up in affected/immediately nearby places
per code review commentary.
Fixes#11599
Signed-off-by: James Tucker <james@tailscale.com>
Config.singleResolverSet returns true if all routes have the same resolvers,
even if the routes have no resolvers. If none of the routes have a specific
resolver, the default should be used instead. Therefore, check for more than
0 instead of nil.
Signed-off-by: Ryan Petris <ryan@petris.net>
We weren't correctly retrying truncated requests to an upstream DNS
server with TCP. Instead, we'd return a truncated request to the user,
even if the user was querying us over TCP and thus able to handle a
large response.
Also, add an envknob and controlknob to allow users/us to disable this
behaviour if it turns out to be buggy (✨ DNS ✨).
Updates #9264
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ifb04b563839a9614c0ba03e9c564e8924c1a2bfd
On some platforms (notably macOS and iOS) we look up the default
interface to bind outgoing connections to. This is both duplicated
work and results in logspam when the default interface is not available
(i.e. when a phone has no connectivity, we log an error and thus cause
more things that we will try to upload and fail).
Fixed by passing around a netmon.Monitor to more places, so that we can
use its cached interface state.
Fixes#7850
Updates #7621
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
We're using it in more and more places, and it's not really specific to
our use of Wireguard (and does more just link/interface monitoring).
Also removes the separate interface we had for it in sockstats -- it's
a small enough package (we already pull in all of its dependencies
via other paths) that it's not worth the extra complexity.
Updates #7621
Updates #7850
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
With a42a594bb3, iOS uses netstack and
hence there are no longer any platforms which use the legacy MagicDNS path. As such, we remove it.
We also normalize the limit for max in-flight DNS queries on iOS (it was 64, now its 256 as per other platforms).
It was 64 for the sake of being cautious about memory, but now we have 50Mb (iOS-15 and greater) instead of 15Mb
so we have the spare headroom.
Signed-off-by: Tom DNetto <tom@tailscale.com>
We saw a few cases where we hit this limit; bumping to 4k seems
relatively uncontroversial.
Change-Id: I218fee3bc0d2fa5fde16eddc36497a73ebd7cbda
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Previously, if a DNS-over-TCP message was received while there were
existing queries in-flight, and it was over the size limit, we'd close
the 'responses' channel. This would cause those in-flight queries to
send on the closed channel and panic.
Instead, don't close the channel at all and rely on s.ctx being
canceled, which will ensure that in-flight queries don't hang.
Fixes#6725
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I8267728ac37ed7ae38ddd09ce2633a5824320097
Most visible when using tsnet.Server, but could have resulted in dropped
messages in a few other places too.
Fixes#5743
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
NextDNS is unique in that users create accounts and then get
user-specific DNS IPs & DoH URLs.
For DoH, the customer ID is in the URL path.
For IPv6, the IP address includes the customer ID in the lower bits.
For IPv4, there's a fragile "IP linking" mechanism to associate your
public IPv4 with an assigned NextDNS IPv4 and that tuple maps to your
customer ID.
We don't use the IP linking mechanism.
Instead, NextDNS is DoH-only. Which means using NextDNS necessarily
shunts all DNS traffic through 100.100.100.100 (programming the OS to
use 100.100.100.100 as the global resolver) because operating systems
can't usually do DoH themselves.
Once it's in Tailscale's DoH client, we then connect out to the known
NextDNS IPv4/IPv6 anycast addresses.
If the control plane sends the client a NextDNS IPv6 address, we then
map it to the corresponding NextDNS DoH with the same client ID, and
we dial that DoH server using the combination of v4/v6 anycast IPs.
Updates #2452
Change-Id: I3439d798d21d5fc9df5a2701839910f5bef85463
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If ExtraRecords (Hosts) are specified without a corresponding split
DNS route and global DNS is specified, then program the host OS DNS to
use 100.100.100.100 so it can blend in those ExtraRecords.
Updates #1543
Change-Id: If49014a5ecc8e38978ff26e54d1f74fe8dbbb9bc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This works around the 2.3s delay in short name lookups when SNR is
enabled.
C:\Windows\System32\drivers\etc\hosts file. We only add known hosts that
match the search domains, and we populate the list in order of
Search Domains so that our matching algorithm mimics what Windows would
otherwise do itself if SNR was off.
Updates #1659
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Currently we forward unmatched queries to the default resolver on
Windows. This results in duplicate queries being issued to the same
resolver which is just wasted.
Updates #1659
Signed-off-by: Maisem Ali <maisem@tailscale.com>
As discussed in previous PRs, we can register for notifications when group
policies are updated and act accordingly.
This patch changes nrptRuleDatabase to receive notifications that group policy
has changed and automatically move our NRPT rules between the local and
group policy subkeys as needed.
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
Fixes https://github.com/tailscale/corp/issues/5198
The upstream forwarder will block indefinitely on `udpconn.ReadFrom` if no
reply is recieved, due to the lack of deadline on the connection object.
There still isn't a deadline on the connection object, but the automatic closing
of the context on deadline expiry will close the connection via `closeOnCtxDone`,
unblocking the read and resulting in a normal teardown.
Signed-off-by: Tom DNetto <tom@tailscale.com>
* net/dns, wgengine: implement DNS over TCP
Signed-off-by: Tom DNetto <tom@tailscale.com>
* wgengine/netstack: intercept only relevant port/protocols to quad-100
Signed-off-by: Tom DNetto <tom@tailscale.com>
Claus Lensbøl
Brad Fitzpatrick
Jonathan Nobels
Aaron Klotz
Andrea Gottardo
Nick Khyl
James Tucker
Andrew Lytvynov
Ryan Petris
Andrew Dunham
David Anderson
Mihai Parparita
Will Norris
Tom DNetto
Maisem Ali
Josh Soref
Tom