Commit Graph

1089 Commits (5f4a4c6744fbda767d5bf4b3299a16aea80c4d1c)

Author SHA1 Message Date
Brad Fitzpatrick 5ec01bf3ce wgengine/filter: support FilterRules matching on srcIP node caps [capver 100]
See #12542 for background.

Updates #12542

Change-Id: Ida312f700affc00d17681dc7551ee9672eeb1789
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Brad Fitzpatrick 162d593514 net/flowtrack: fix, test String method
I meant to do this in the earlier change and had a git fail.

To atone, add a test too while I'm here.

Updates #12486
Updates #12507

Change-Id: I4943b454a2530cb5047636f37136aa2898d2ffc7
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Brad Fitzpatrick 9e0a5cc551 net/flowtrack: optimize Tuple type for use as map key
This gets UDP filter overhead closer to TCP. Still ~2x, but no longer ~3x.

    goos: darwin
    goarch: arm64
    pkg: tailscale.com/wgengine/filter
                                       │   before    │                after                │
                                       │   sec/op    │   sec/op     vs base                │
    FilterMatch/tcp-not-syn-v4-8         15.43n ± 3%   15.38n ± 5%        ~ (p=0.339 n=10)
    FilterMatch/udp-existing-flow-v4-8   42.45n ± 0%   34.77n ± 1%  -18.08% (p=0.000 n=10)
    geomean                              25.59n        23.12n        -9.65%

Updates #12486

Change-Id: I595cfadcc6b7234604bed9c4dd4261e087c0d4c4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Brad Fitzpatrick bd93c3067e wgengine/filter/filtertype: make Match.IPProto a view
I noticed we were allocating these every time when they could just
share the same memory. Rather than document ownership, just lock it
down with a view.

I was considering doing all of the fields but decided to just do this
one first as test to see how infectious it became.  Conclusion: not
very.

Updates #cleanup (while working towards tailscale/corp#20514)

Change-Id: I8ce08519de0c9a53f20292adfbecd970fe362de0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Brad Fitzpatrick 1f6645b19f net/ipset: skip the loop over Prefixes when there's only one
For pprof cosmetic/confusion reasons more than performance, but it
might have tiny speed benefit.

Updates #12486

Change-Id: I40e03714f3afa3a7e7f5e1fa99b81c7e889b91b6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Brad Fitzpatrick bf2d13cfa0 net/ipset: return all closures from named wrappers
So profiles show more useful names than just func1, func2, func3, etc.
There will still be func1 on them all, but the symbol before will say
what the lookup type is.

Updates #12486

Change-Id: I910b024a7861394eb83d07f5a899eae338cb1f22
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Brad Fitzpatrick 86e0f9b912 net/ipset, wgengine/filter/filtertype: add split-out packages
This moves NewContainsIPFunc from tsaddr to new ipset package.

And wgengine/filter types gets split into wgengine/filter/filtertype,
so netmap (and thus the CLI, etc) doesn't need to bring in ipset,
bart, etc.

Then add a test making sure the CLI deps don't regress.

Updates #1278

Change-Id: Ia246d6d9502bbefbdeacc4aef1bed9c8b24f54d5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Brad Fitzpatrick 64ac64fb66 net/tsaddr: use bart in NewContainsIPFunc, add tests, benchmarks
NewContainsIPFunc was previously documented as performing poorly if
there were many netip.Prefixes to search over. As such, we never it used it
in such cases.

This updates it to use bart at a certain threshold (over 6 prefixes,
currently), at which point the bart lookup overhead pays off.

This is currently kinda useless because we're not using it. But now we
can and get wins elsewhere. And we can remove the caveat in the docs.

    goos: darwin
    goarch: arm64
    pkg: tailscale.com/net/tsaddr
                                     │    before    │                after                 │
                                     │    sec/op    │    sec/op     vs base                │
    NewContainsIPFunc/empty-8          2.215n ± 11%   2.239n ±  1%   +1.08% (p=0.022 n=10)
    NewContainsIPFunc/cidr-list-1-8    17.44n ±  0%   17.59n ±  6%   +0.89% (p=0.000 n=10)
    NewContainsIPFunc/cidr-list-2-8    27.85n ±  0%   28.13n ±  1%   +1.01% (p=0.000 n=10)
    NewContainsIPFunc/cidr-list-3-8    36.05n ±  0%   36.56n ± 13%   +1.41% (p=0.000 n=10)
    NewContainsIPFunc/cidr-list-4-8    43.73n ±  0%   44.38n ±  1%   +1.50% (p=0.000 n=10)
    NewContainsIPFunc/cidr-list-5-8    51.61n ±  2%   51.75n ±  0%        ~ (p=0.101 n=10)
    NewContainsIPFunc/cidr-list-10-8   95.65n ±  0%   68.92n ±  0%  -27.94% (p=0.000 n=10)
    NewContainsIPFunc/one-ip-8         4.466n ±  0%   4.469n ±  1%        ~ (p=0.491 n=10)
    NewContainsIPFunc/two-ip-8         8.002n ±  1%   7.997n ±  4%        ~ (p=0.697 n=10)
    NewContainsIPFunc/three-ip-8       27.98n ±  1%   27.75n ±  0%   -0.82% (p=0.012 n=10)
    geomean                            19.60n         19.07n         -2.71%

Updates #12486

Change-Id: I2e2320cc4384f875f41721374da536bab995c1ce
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Nick Khyl c32efd9118 various: create a catch-all NRPT rule when "Override local DNS" is enabled on Windows
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.

Fixes tailscale/corp#20718

Signed-off-by: Nick Khyl <nickk@tailscale.com>
5 months ago
Andrea Gottardo a8ee83e2c5
health: begin work to use structured health warnings instead of strings, pipe changes into ipn.Notify (#12406)
Updates tailscale/tailscale#4136

This PR is the first round of work to move from encoding health warnings as strings and use structured data instead. The current health package revolves around the idea of Subsystems. Each subsystem can have (or not have) a Go error associated with it. The overall health of the backend is given by the concatenation of all these errors.

This PR polishes the concept of Warnable introduced by @bradfitz a few weeks ago. Each Warnable is a component of the backend (for instance, things like 'dns' or 'magicsock' are Warnables). Each Warnable has a unique identifying code. A Warnable is an entity we can warn the user about, by setting (or unsetting) a WarningState for it. Warnables have:

- an identifying Code, so that the GUI can track them as their WarningStates come and go
- a Title, which the GUIs can use to tell the user what component of the backend is broken
- a Text, which is a function that is called with a set of Args to generate a more detailed error message to explain the unhappy state

Additionally, this PR also begins to send Warnables and their WarningStates through LocalAPI to the clients, using ipn.Notify messages. An ipn.Notify is only issued when a warning is added or removed from the Tracker.

In a next PR, we'll get rid of subsystems entirely, and we'll start using structured warnings for all errors affecting the backend functionality.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
5 months ago
Jordan Whited 65888d95c9
derp/xdp,cmd/xdpderper: initial skeleton (#12390)
This commit introduces a userspace program for managing an experimental
eBPF XDP STUN server program. derp/xdp contains the eBPF pseudo-C along
with a Go pkg for loading it and exporting its metrics.
cmd/xdpderper is a package main user of derp/xdp.

Updates tailscale/corp#20689

Signed-off-by: Jordan Whited <jordan@tailscale.com>
5 months ago
Jonathan Nobels 02e3c046aa
net/dns: re-query system resolvers on no-upstream resolver failure on apple platforms (#12398)
Fixes tailscale/corp#20677

On macOS sleep/wake, we're encountering a condition where reconfigure the network
a little bit too quickly - before apple has set the nameservers for our interface.
This results in a persistent condition where we have no upstream resolver and
fail all forwarded DNS queries.

No upstream nameservers is a legitimate configuration, and we have no  (good) way
of determining when Apple is ready - but if we need to forward a query, and we
have no nameservers, then something has gone badly wrong and the network is
very broken.

A simple fix here is to simply inject a netMon event, which will go through the
configuration dance again when we hit the SERVFAIL condition.

Tested by artificially/randomly returning [] for the list of nameservers in the bespoke
ipn-bridge code responsible for getting the nameservers.

Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
5 months ago
Andrew Dunham d0f1a838a6 net/dnscache: use parent context to perform lookup
As an alterative to #11935 using #12003.

Updates #11935

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I05f643fe812ceeaec5f266e78e3e529cab3a1ac3
5 months ago
Aaron Klotz 3511d1f8a2 cmd/tailscaled, net/dns, wgengine/router: start Windows child processes with DETACHED_PROCESS when I/O is being piped
When we're starting child processes on Windows that are CLI programs that
don't need to output to a console, we should pass in DETACHED_PROCESS as a
CreationFlag on SysProcAttr. This prevents the OS from even creating a console
for the child (and paying the associated time/space penalty for new conhost
processes). This is more efficient than letting the OS create the console
window and then subsequently trying to hide it, which we were doing at a few
callsites.

Fixes #12270

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
5 months ago
Nick Khyl 4cdc4ed7db net/dns/resolver: return an empty successful response instead of NXDomain when resolving A records for 4via6 domains
As quad-100 is an authoritative server for 4via6 domains, it should always return responses
with a response code of 0 (indicating no error) when resolving records for these domains.
If there's no resource record of the specified type (e.g. A), it should return a response
with an empty answer section rather than NXDomain. Such a response indicates that there
is at least one RR of a different type (e.g., AAAA), suggesting the Windows stub resolver
to look for it.

Fixes tailscale/corp#20767

Signed-off-by: Nick Khyl <nickk@tailscale.com>
5 months ago
Irbe Krumina bc53ebd4a0
ipn/{ipnlocal,localapi},net/netkernelconf,client/tailscale,cmd/containerboot: optionally enable UDP GRO forwarding for containers (#12410)
Add a new TS_EXPERIMENTAL_ENABLE_FORWARDING_OPTIMIZATIONS env var
that can be set for tailscale/tailscale container running as
a subnet router or exit node to enable UDP GRO forwarding
for improved performance.
See https://tailscale.com/kb/1320/performance-best-practices#linux-optimizations-for-subnet-routers-and-exit-nodes
This is currently considered an experimental approach;
the configuration support is partially to allow further experimentation
with containerized environments to evaluate the performance
improvements.

Updates tailscale/tailscale#12295

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
5 months ago
Brad Fitzpatrick 916c4db75b net/dns: fix crash in tests
Looks like #12346 as submitted with failing tests.

Updates #12346

Change-Id: I582cd0dfb117686330d935d763d972373c5ae598
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Andrea Gottardo b65221999c
tailcfg,net/dns: add controlknob to disable battery split DNS on iOS (#12346)
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>
5 months ago
Brad Fitzpatrick 1ca323ac65 net/netcheck: fix probeProto.String result for IPv6 probes
This bug was introduced in e6b84f215 (May 2020) but was only used in
tests when stringifying probeProto values on failure so it wasn't
noticed for a long time.

But then it was moved into non-test code in 8450a18aa (Jun 2024) and I
didn't notice during the code movement that it was wrong. It's still
only used in failure paths in logs, but having wrong/ambiguous
debugging information isn't the best.

Whoops.

Updates tailscale/corp#20654

Change-Id: I296c727ed1c292a04db7b46ecc05c07fc1abc774
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Brad Fitzpatrick 8450a18aa9 net/netcheck: flesh out some logging in error paths
Updates tailscale/corp#20654

Change-Id: Ie190f956b864985668f79b5b986438bbe07ce905
5 months ago
Maisem Ali 4a8cb1d9f3 all: use math/rand/v2 more
Updates #11058

Signed-off-by: Maisem Ali <maisem@tailscale.com>
5 months ago
Andrea Gottardo d636407f14
net/dns: don't set MatchDomains on Apple platforms when no upstream nameservers available (#12334)
This PR addresses a DNS issue on macOS as discussed this morning.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
5 months ago
Andrew Dunham ced9a0d413
net/dns: fix typo in OSConfig logging (#12330)
Updates tailscale/corp#20530

Change-Id: I48834a0a5944ed35509c63bdd2830aa34e1bddeb

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
5 months ago
Maisem Ali 42cfbf427c tsnet,wgengine/netstack: add ListenPacket and tests
This adds a new ListenPacket function on tsnet.Server
which acts mostly like `net.ListenPacket`.

Unlike `Server.Listen`, this requires listening on a
specific IP and does not automatically listen on both
V4 and V6 addresses of the Server when the IP is unspecified.

To test this, it also adds UDP support to tsdial.Dialer.UserDial
and plumbs it through the localapi. Then an associated test
to make sure the UDP functionality works from both sides.

Updates #12182

Signed-off-by: Maisem Ali <maisem@tailscale.com>
5 months ago
Andrea Gottardo dd77111462
xcode/iOS: set MatchDomains when no route requires a custom DNS resolver (#10576)
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>
6 months ago
James Tucker 87ee559b6f net/netcheck: apply some polish suggested from #12161
Apply some post-submit code review suggestions.

Updates #12161
Updates tailscale/corp#19106

Signed-off-by: James Tucker <james@tailscale.com>
6 months ago
James Tucker 9351eec3e1 net/netcheck: remove hairpin probes
Palo Alto reported interpreting hairpin probes as LAND attacks, and the
firewalls may be responding to this by shutting down otherwise in use NAT sessions
prematurely. We don't currently make use of the outcome of the hairpin
probes, and they contribute to other user confusion with e.g. the
AirPort Extreme hairpin session workaround. We decided in response to
remove the whole probe feature as a result.

Updates #188
Updates tailscale/corp#19106
Updates tailscale/corp#19116

Signed-off-by: James Tucker <james@tailscale.com>
6 months ago
James Tucker 8d1249550a net/netcheck,wgengine/magicsock: add potential workaround for Palo Alto DIPP misbehavior
Palo Alto firewalls have a typically hard NAT, but also have a mode
called Persistent DIPP that is supposed to provide consistent port
mapping suitable for STUN resolution of public ports. Persistent DIPP
works initially on most Palo Alto firewalls, but some models/software
versions have a bug which this works around.

The bug symptom presents as follows:

- STUN sessions resolve a consistent public IP:port to start with
- Much later netchecks report the same IP:Port for a subset of
  sessions, most often the users active DERP, and/or the port related
  to sustained traffic.
- The broader set of DERPs in a full netcheck will now consistently
  observe a new IP:Port.
- After this point of observation, new inbound connections will only
  succeed to the new IP:Port observed, and existing/old sessions will
  only work to the old binding.

In this patch we now advertise the lowest latency global endpoint
discovered as we always have, but in addition any global endpoints that
are observed more than once in a single netcheck report. This should
provide viable endpoints for potential connection establishment across
a NAT with this behavior.

Updates tailscale/corp#19106

Signed-off-by: James Tucker <james@tailscale.com>
6 months ago
Kevin Liang 7f83f9fc83 Net/DNS/Publicdns: update the IPv6 range that we use to recreate route endpoint for control D
In this commit I updated the Ipv6 range we use to generate Control D DOH ip, we were using the NextDNSRanges to generate Control D DOH ip, updated to use the correct range.

Updates: #7946
Signed-off-by: Kevin Liang <kevinliang@tailscale.com>
6 months ago
Maisem Ali 1f51bb6891 net/tstun: do SNAT after filterPacketOutboundToWireGuard
In a configuration where the local node (ip1) has a different IP (ip2)
that it uses to communicate with a peer (ip3) we would do UDP flow
tracking on the `ip2->ip3` tuple. When we receive the response from
the peer `ip3->ip2` we would dnat it back to `ip3->ip1` which would
then not match the flow track state and the packet would get dropped.

To fix this, we should do flow tracking on the `ip1->ip3` tuple instead
of `ip2->ip3` which requires doing SNAT after the running filterPacketOutboundToWireGuard.

Updates tailscale/corp#19971, tailscale/corp#8020

Signed-off-by: Maisem Ali <maisem@tailscale.com>
6 months ago
Maisem Ali 85b9a6c601 net/netcheck: do not add derps if IPv4/IPv6 is set to "none"
It was documented as such but seems to have been dropped in a
refactor, restore the behavior. This brings down the time it
takes to run a single integration test by 2s which adds up
quite a bit.

Updates tailscale/corp#19786

Signed-off-by: Maisem Ali <maisem@tailscale.com>
6 months ago
Maisem Ali af97e7a793 tailcfg,all: add/plumb Node.IsJailed
This adds a new bool that can be sent down from control
to do jailing on the client side. Previously this would
only be done from control by modifying the packet filter
we sent down to clients. This would result in a lot of
additional work/CPU on control, we could instead just
do this on the client. This has always been a TODO which
we keep putting off, might as well do it now.

Updates tailscale/corp#19623

Signed-off-by: Maisem Ali <maisem@tailscale.com>
6 months ago
Maisem Ali e67069550b ipn/ipnlocal,net/tstun,wgengine: create and plumb jailed packet filter
This plumbs a packet filter for jailed nodes through to the
tstun.Wrapper; the filter for a jailed node is equivalent to a "shields
up" filter. Currently a no-op as there is no way for control to
tell the client whether a peer is jailed.

Updates tailscale/corp#19623

Co-authored-by: Andrew Dunham <andrew@du.nham.ca>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Change-Id: I5ccc5f00e197fde15dd567485b2a99d8254391ad
6 months ago
Nick Khyl f62e678df8 net/dns/resolver, control/controlknobs, tailcfg: use UserDial instead of SystemDial to dial DNS servers
Now that tsdial.Dialer.UserDial has been updated to honor the configured routes
and dial external network addresses without going through Tailscale, while also being
able to dial a node/subnet router on the tailnet, we can start using UserDial to forward
DNS requests. This is primarily needed for DNS over TCP when forwarding requests
to internal DNS servers, but we also update getKnownDoHClientForProvider to use it.

Updates tailscale/corp#18725

Signed-off-by: Nick Khyl <nickk@tailscale.com>
6 months ago
Maisem Ali 5ef178fdca net/tstun: refactor peerConfig to allow storing more details
This refactors the peerConfig struct to allow storing more
details about a peer and not just the masq addresses. To be
used in a follow up change.

As a side effect, this also makes the DNAT logic on the inbound
packet stricter. Previously it would only match against the packets
dst IP, not it also takes the src IP into consideration. The beahvior
is at parity with the SNAT case.

Updates tailscale/corp#19623

Co-authored-by: Andrew Dunham <andrew@du.nham.ca>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Change-Id: I5f40802bebbf0f055436eb8824e4511d0052772d
6 months ago
Nick Khyl caa3d7594f ipn/ipnlocal, net/tsdial: plumb routes into tsdial and use them in UserDial
We'd like to use tsdial.Dialer.UserDial instead of SystemDial for DNS over TCP.
This is primarily necessary to properly dial internal DNS servers accessible
over Tailscale and subnet routes. However, to avoid issues when switching
between Wi-Fi and cellular, we need to ensure that we don't retain connections
to any external addresses on the old interface. Therefore, we need to determine
which dialer to use internally based on the configured routes.

This plumbs routes and localRoutes from router.Config to tsdial.Dialer,
and updates UserDial to use either the peer dialer or the system dialer,
depending on the network address and the configured routes.

Updates tailscale/corp#18725
Fixes #4529

Signed-off-by: Nick Khyl <nickk@tailscale.com>
6 months ago
Brad Fitzpatrick ce8969d82b net/portmapper: add envknob to disable portmapper in localhost integration tests
Updates #11962

Change-Id: I8212cd814985b455d96986de0d4c45f119516cb3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
6 months ago
Brad Fitzpatrick c3c18027c6 all: make more tests pass/skip in airplane mode
Updates tailscale/corp#19786

Change-Id: Iedc6730fe91c627b556bff5325bdbaf7bf79d8e6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
6 months ago
Maisem Ali fd6ba43b97 types/views: remove duplicate SliceContainsFunc
We already have `(Slice[T]).ContainsFunc`.

Updates #cleanup

Signed-off-by: Maisem Ali <maisem@tailscale.com>
6 months ago
Brad Fitzpatrick e42c4396cf net/netcheck: don't spam on ICMP socket permission denied errors
While debugging a failing test in airplane mode on macOS, I noticed
netcheck logspam about ICMP socket creation permission denied errors.

Apparently macOS just can't do those, or at least not in airplane
mode. Not worth spamming about.

Updates #cleanup

Change-Id: I302620cfd3c8eabb25202d7eef040c01bd8a843c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
6 months ago
Brad Fitzpatrick ee3bd4dbda derp/derphttp, net/netcheck: plumb netmon.Monitor to derp netcheck client
Fixes #11981

Change-Id: I0e15a09f93aefb3cfddbc12d463c1c08b83e09fd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
6 months ago
Andrew Dunham f97d0ac994 net/dns/resolver: add better error wrapping
To aid in debugging exactly what's going wrong, instead of the
not-particularly-useful "dns udp query: context deadline exceeded" error
that we currently get.

Updates #3786
Updates #10768
Updates #11620
(etc.)

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I76334bf0681a8a2c72c90700f636c4174931432c
6 months ago
Andrew Dunham be663c84c1 net/tstun: rename natConfig to peerConfig
So that we can use this for additional, non-NAT configuration without it
being confusing.

Updates #cleanup

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I1658d59c9824217917a94ee76d2d08f0a682986f
6 months ago
Andrew Dunham 10497acc95 net/tstun: refactor natConfig to not be per-family
This was a holdover from the older, pre-BART days and is no longer
necessary.

Updates #cleanup

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I71b892bab1898077767b9ff51cef33d59c08faf8
6 months ago
Jonathan Nobels 45b9aa0d83
net/netmon: remove spammy log statements (#11953)
Updates tailscale/corp#18960

Tests in corp called us using the wrong logging calls.  Removed.
This is logged downstream anyway.

Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
6 months ago
Jonathan Nobels fa1303d632
net/netmon: swap to swift-derived defaultRoute on macos (#11936)
Updates tailscale/corp#18960

iOS uses Apple's NetworkMonitor to track the default interface and
there's no reason we shouldn't also use this on macOS, for the same
reasons noted in the comments for why this change was made on iOS.

This eliminates the need to load and parse the routing table when
querying the defaultRouter() in almost all cases.

A slight modification here (on both platforms) to fallback to the default
BSD logic in the unhappy-path rather than making assumptions that
may not hold.  If netmon is eventually parsing AF_ROUTE and able
to give a consistently correct answer for the  default interface index,
we can fall back to that and eliminate the Swift dependency.

Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
6 months ago
Jordan Whited a47ce618bd
net/tstun: implement env var for disabling UDP GRO on Linux (#11924)
Certain device drivers (e.g. vxlan, geneve) do not properly handle
coalesced UDP packets later in the stack, resulting in packet loss.

Updates #11026

Signed-off-by: Jordan Whited <jordan@tailscale.com>
6 months ago
Brad Fitzpatrick b9adbe2002 net/{interfaces,netmon}, all: merge net/interfaces package into net/netmon
In prep for most of the package funcs in net/interfaces to become
methods in a long-lived netmon.Monitor that can cache things.  (Many
of the funcs are very heavy to call regularly, whereas the long-lived
netmon.Monitor can subscribe to things from the OS and remember
answers to questions it's asked regularly later)

Updates tailscale/corp#10910
Updates tailscale/corp#18960
Updates #7967
Updates #3299

Change-Id: Ie4e8dedb70136af2d611b990b865a822cd1797e5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick 6b95219e3a net/netmon, add: add netmon.State type alias of interfaces.State
... in prep for merging the net/interfaces package into net/netmon.

This is a no-op change that updates a bunch of the API signatures ahead of
a future change to actually move things (and remove the type alias)

Updates tailscale/corp#10910
Updates tailscale/corp#18960
Updates #7967
Updates #3299

Change-Id: I477613388f09389214db0d77ccf24a65bff2199c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick 3672f29a4e net/netns, net/dns/resolver, etc: make netmon required in most places
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>
7 months ago
Brad Fitzpatrick 7a62dddeac net/netcheck, wgengine/magicsock: make netmon.Monitor required
This has been a TODO for ages. Time to do it.

The goal is to move more network state accessors to netmon.Monitor
where they can be cheaper/cached.

Updates tailscale/corp#10910
Updates tailscale/corp#18960
Updates #7967
Updates #3299

Change-Id: I60fc6508cd2d8d079260bda371fc08b6318bcaf1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick 4dece0c359 net/netutil: remove a use of deprecated interfaces.GetState
I'm working on moving all network state queries to be on
netmon.Monitor, removing old APIs.

Updates tailscale/corp#10910
Updates tailscale/corp#18960
Updates #7967
Updates #3299

Change-Id: If0de137e0e2e145520f69e258597fb89cf39a2a3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick 745931415c health, all: remove health.Global, finish plumbing health.Tracker
Updates #11874
Updates #4136

Change-Id: I414470f71d90be9889d44c3afd53956d9f26cd61
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick 723c775dbb tsd, ipnlocal, etc: add tsd.System.HealthTracker, start some plumbing
This adds a health.Tracker to tsd.System, accessible via
a new tsd.System.HealthTracker method.

In the future, that new method will return a tsd.System-specific
HealthTracker, so multiple tsnet.Servers in the same process are
isolated. For now, though, it just always returns the temporary
health.Global value. That permits incremental plumbing over a number
of changes. When the second to last health.Global reference is gone,
then the tsd.System.HealthTracker implementation can return a private
Tracker.

The primary plumbing this does is adding it to LocalBackend and its
dozen and change health calls. A few misc other callers are also
plumbed. Subsequent changes will flesh out other parts of the tree
(magicsock, controlclient, etc).

Updates #11874
Updates #4136

Change-Id: Id51e73cfc8a39110425b6dc19d18b3975eac75ce
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick 5b32264033 health: break Warnable into a global and per-Tracker value halves
Previously it was both metadata about the class of warnable item as
well as the value.

Now it's only metadata and the value is per-Tracker.

Updates #11874
Updates #4136

Change-Id: Ia1ed1b6c95d34bc5aae36cffdb04279e6ba77015
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick ebc552d2e0 health: add Tracker type, in prep for removing global variables
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>
7 months ago
Andrew Dunham 375617c5c8 net/tsdial: assume all connections are affected if no default route is present
If this happens, it results in us pessimistically closing more
connections than might be necessary, but is more correct since we won't
"miss" a change to the default route interface and keep trying to send
data over a nonexistent interface, or one that can't reach the internet.

Updates tailscale/corp#19124

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ia0b8b04cb8cdcb0da0155fd08751c9dccba62c1a
7 months ago
kari-ts 048cb61dd0
interfaces: create android impl (#11784)
-Move Android impl into interfaces_android.go
-Instead of using ip route to get the interface name, use the one passed in by Android (ip route is restricted in Android 13+ per termux/termux-app#2993)

Follow-up will be to do the same for router

Fixes tailscale/corp#19215
Fixes tailscale/corp#19124

Signed-off-by: kari-ts <kari@tailscale.com>
7 months ago
Andrew Dunham b85c2b2313 net/dns/resolver: use SystemDial in DoH forwarder
This ensures that we close the underlying connection(s) when a major
link change happens. If we don't do this, on mobile platforms switching
between WiFi and cellular can result in leftover connections in the
http.Client's connection pool which are bound to the "wrong" interface.

Updates #10821
Updates tailscale/corp#19124

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ibd51ce2efcaf4bd68e14f6fdeded61d4e99f9a01
7 months ago
Andrew Dunham 226486eb9a net/interfaces: handle removed interfaces in State.Equal
This wasn't previously handling the case where an interface in s2 was
removed and not present in s1, and would cause the Equal method to
incorrectly return that the states were equal.

Updates tailscale/corp#19124

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I3af22bc631015d1ddd0a1d01bfdf312161b9532d
7 months ago
Brad Fitzpatrick 7c1d6e35a5 all: use Go 1.22 range-over-int
Updates #11058

Change-Id: I35e7ef9b90e83cac04ca93fd964ad00ed5b48430
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick 068db1f972 net/interfaces: delete unused unexported function
It should've been deleted in 11ece02f52.

Updates #9040

Change-Id: If8a136bdb6c82804af658c9d2b0a8c63ce02d509
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick a1abd12f35 cmd/tailscaled, net/tstun: build for aix/ppc64
At least in userspace-networking mode.

Fixes #11361

Change-Id: I78d33f0f7e05fe9e9ee95b97c99b593f8fe498f2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Aaron Klotz 4d5d669cd5 net/dns: unconditionally write NRPT rules to local settings
We were being too aggressive when deciding whether to write our NRPT rules
to the local registry key or the group policy registry key.

After once again reviewing the document which calls itself a spec
(see issue), it is clear that the presence of the DnsPolicyConfig subkey
is the important part, not the presence of values set in the DNSClient
subkey. Furthermore, a footnote indicates that the presence of
DnsPolicyConfig in the GPO key will always override its counterpart in
the local key. The implication of this is important: we may unconditionally
write our NRPT rules to the local key. We copy our rules to the policy
key only when it contains NRPT rules belonging to somebody other than us.

Fixes https://github.com/tailscale/corp/issues/19071

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
7 months ago
James Tucker db760d0bac cmd/tailscaled: move cleanup to an implicit action during startup
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>
7 months ago
Brad Fitzpatrick b0fbd85592 net/tsdial: partially fix "tailscale nc" (UserDial) on macOS
At least in the case of dialing a Tailscale IP.

Updates #4529

Change-Id: I9fd667d088a14aec4a56e23aabc2b1ffddafa3fe
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
alexelisenko fe22032fb3
net/dns/{publicdns,resolver}: add start of Control D support
Updates #7946

[@bradfitz fixed up version of #8417]

Change-Id: I1dbf6fa8d525b25c0d7ad5c559a7f937c3cd142a
Signed-off-by: alexelisenko <39712468+alexelisenko@users.noreply.github.com>
Signed-off-by: Alex Paguis <alex@windscribe.com>
7 months ago
James Tucker 6e334e64a1 net/netcheck,wgengine/magicsock: align DERP frame receive time heuristics
The netcheck package and the magicksock package coordinate via the
health package, but both sides have time based heuristics through
indirect dependencies. These were misaligned, so the implemented
heuristic aimed at reducing DERP moves while there is active traffic
were non-operational about 3/5ths of the time.

It is problematic to setup a good test for this integration presently,
so instead I added comment breadcrumbs along with the initial fix.

Updates #8603

Signed-off-by: James Tucker <james@tailscale.com>
7 months ago
Brad Fitzpatrick 8d7894c68e clientupdate, net/dns: fix some "tailsacle" typos
Updates #cleanup

Change-Id: I982175e74b0c8c5b3e01a573e5785e6596b7ac39
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
James Tucker f384742375 net/packet: allow more ICMP errors
We now allow some more ICMP errors to flow, specifically:

- ICMP parameter problem in both IPv4 and IPv6 (corrupt headers)
- ICMP Packet Too Big (for IPv6 PMTU)

Updates #311
Updates #8102
Updates #11002

Signed-off-by: James Tucker <james@tailscale.com>
7 months ago
Asutorufa e20ce7bf0c net/dns: close ctx when close dns directManager
Signed-off-by: Asutorufa <16442314+Asutorufa@users.noreply.github.com>
8 months ago
Percy Wegmann 8b8b315258 net/tstun: use gaissmai/bart instead of tempfork/device
This implementation uses less memory than tempfork/device,
which helps avoid OOM conditions in the iOS VPN extension when
switching to a Tailnet with ExitNode routing enabled.

Updates tailscale/corp#18514

Signed-off-by: Percy Wegmann <percy@tailscale.com>
8 months ago
Brad Fitzpatrick a36cfb4d3d tailcfg, ipn/ipnlocal, wgengine/magicsock: add only-tcp-443 node attr
Updates tailscale/corp#17879

Change-Id: I0dc305d147b76c409cf729b599a94fa723aef0e0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
8 months ago
Anton Tolchanov cf8948da5f net/routetable: increase route limit used by the test
I was running all tests while preparing a recent stable release, and
this was failing because my computer is connected to a fairly large
tailnet.

```
--- FAIL: TestGetRouteTable (0.01s)
    routetable_linux_test.go:32: expected at least one default route;
    ...
```

```
$ ip route show table 52  | wc -l
1051
```

Updates #cleanup

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
8 months ago
Andrew Dunham 9884d06b80 net/interfaces: fix test hang on Darwin
This test could hang because the subprocess was blocked on writing to
the stdout pipe if we find the address we're looking for early in the
output.

Updates #cleanup

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I68d82c22a5d782098187ae6d8577e43063b72573
8 months ago
Andrew Dunham 62cf83eb92 go.mod: bump gvisor
The `stack.PacketBufferPtr` type no longer exists; replace it with
`*stack.PacketBuffer` instead.

Updates #8043

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ib56ceff09166a042aa3d9b80f50b2aa2d34b3683
8 months ago
Andrew Dunham 3dd8ae2f26 net/tstun: fix spelling of "WireGuard"
Updates #cleanup

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ida7e30f4689bc18f5f7502f53a0adb5ac3c7981a
9 months ago
Anton Tolchanov 8cc5c51888 health: warn about reverse path filtering and exit nodes
When reverse path filtering is in strict mode on Linux, using an exit
node blocks all network connectivity. This change adds a warning about
this to `tailscale status` and the logs.

Example in `tailscale status`:

```
- not connected to home DERP region 22
- The following issues on your machine will likely make usage of exit nodes impossible: [interface "eth0" has strict reverse-path filtering enabled], please set rp_filter=2 instead of rp_filter=1; see https://github.com/tailscale/tailscale/issues/3310
```

Example in the logs:
```
2024/02/21 21:17:07 health("overall"): error: multiple errors:
	not in map poll
	The following issues on your machine will likely make usage of exit nodes impossible: [interface "eth0" has strict reverse-path filtering enabled], please set rp_filter=2 instead of rp_filter=1; see https://github.com/tailscale/tailscale/issues/3310
```

Updates #3310

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
9 months ago
Nick Khyl 7ef1fb113d cmd/tailscaled, ipn/ipnlocal, wgengine: shutdown tailscaled if wgdevice is closed
Tailscaled becomes inoperative if the Tailscale Tunnel wintun adapter is abruptly removed.
wireguard-go closes the device in case of a read error, but tailscaled keeps running.
This adds detection of a closed WireGuard device, triggering a graceful shutdown of tailscaled.
It is then restarted by the tailscaled watchdog service process.

Fixes #11222

Signed-off-by: Nick Khyl <nickk@tailscale.com>
9 months ago
Nick Khyl b42b9817b0 net/dns: do not wait for the interface registry key to appear if the windowsManager is being closed
The WinTun adapter may have been removed by the time we're closing
the dns.windowsManager, and its associated interface registry key might
also have been deleted. We shouldn't use winutil.OpenKeyWait and wait
for the interface key to appear when performing a cleanup as a part of
the windowsManager shutdown.

Updates #11222

Signed-off-by: Nick Khyl <nickk@tailscale.com>
9 months ago
Brad Fitzpatrick e1bd7488d0 all: remove LenIter, use Go 1.22 range-over-int instead
Updates #11058
Updates golang/go#65685

Change-Id: Ibb216b346e511d486271ab3d84e4546c521e4e22
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
9 months ago
mrrfv ff1391a97e net/dns/publicdns: add Mullvad family DNS to the list of known DoH servers
Adds the new Mullvad family DNS server to the known DNS over HTTPS server list.

Signed-off-by: mrrfv <rm-rfv-no-preserve-root@protonmail.com>
9 months ago
James Tucker 8d0d46462b net/dns: timeout DOH requests after 10s without response headers
If a client socket is remotely lost but the client is not sent an RST in
response to the next request, the socket might sit in RTO for extended
lengths of time, resulting in "no internet" for users. Instead, timeout
after 10s, which will close the underlying socket, recovering from the
situation more promptly.

Updates #10967

Signed-off-by: James Tucker <james@tailscale.com>
9 months ago
James Tucker 651c4899ac net/interfaces: reduce & cleanup logs on iOS
We don't need a log line every time defaultRoute is read in the good
case, and we now only log default interface updates that are actually
changes.

Updates #3363

Signed-off-by: James Tucker <james@tailscale.com>
9 months ago
Andrew Dunham e8d2fc7f7f net/tshttpproxy: log when we're using a proxy
Updates #11196

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Id6334c10f52f4cfbda9f03dc8096ab7a6c54a088
9 months ago
James Tucker 8fe504241d net/ktimeout: add a package to set TCP user timeout
Setting a user timeout will be a more practical tuning knob for a number
of endpoints, this provides a way to set it.

Updates tailscale/corp#17587

Signed-off-by: James Tucker <james@tailscale.com>
9 months ago
Andrew Dunham 70b7201744 net/dns: fix infinite loop when run on Amazon Linux 2023
This fixes an infinite loop caused by the configuration of
systemd-resolved on Amazon Linux 2023 and how that interacts with
Tailscale's "direct" mode. We now drop the Tailscale service IP from the
OS's "base configuration" when we detect this configuration.

Updates #7816

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I73a4ea8e65571eb368c7e179f36af2c049a588ee
9 months ago
Andrew Dunham b0e96a6c39 net/dns: log more info when openresolv commands fail
Updates #11129

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ic594868ba3bc31f6d3b0721ecba4090749a81f7f
9 months ago
Brad Fitzpatrick 2bd3c1474b util/cmpx: delete now that we're using Go 1.22
Updates #11058

Change-Id: I09dea8e86f03ec148b715efca339eab8b1f0f644
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
9 months ago
Andrew Dunham fd94d96e2b net/portmapper: support legacy "urn:dslforum-org" portmapping services
These are functionally the same as the "urn:schemas-upnp-org" services
with a few minor changes, and are still used by older devices. Support
them to improve our ability to obtain an external IP on such networks.

Updates #10911

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I05501fad9d6f0a3b8cf19fc95eee80e7d16cc2cf
10 months ago
Andrew Dunham b45089ad85 net/portmapper: handle cases where we have no supported clients
This no longer results in a nil pointer exception when we get a valid
UPnP response with no supported clients.

Updates #10911

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I6e3715a49a193ff5261013871ad7fff197a4d77e
10 months ago
kari-ts c9fd166cc6
net/netmon: when a new network is added, trigger netmon update (#10840)
Fixes #10107
10 months ago
Andrew Dunham 20f3f706a4 net/netutil: allow 16-bit 4via6 site IDs
The prefix has space for 32-bit site IDs, but the validateViaPrefix
function would previously have disallowed site IDs greater than 255.

Fixes tailscale/corp#16470

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I4cdb0711dafb577fae72d86c4014cf623fa538ef
10 months ago
James Tucker 953fa80c6f cmd/{derper,stund},net/stunserver: add standalone stun server
Add a standalone server for STUN that can be hosted independently of the
derper, and factor that back into the derper.

Fixes #8434
Closes #8435
Closes #10745

Signed-off-by: James Tucker <james@tailscale.com>
10 months ago
Andrew Dunham 35c303227a net/dns/resolver: add ID to verbose logs in forwarder
To make it easier to correlate the starting/ending log messages.

Updates #cleanup

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I2802d53ad98e19bc8914bc58f8c04d4443227b26
10 months ago
Andrea Gottardo d9aeb30281
net/interfaces: handle iOS network transitions (#10680)
Updates #8022
Updates #6075

On iOS, we currently rely on delegated interface information to figure out the default route interface.  The NetworkExtension framework in iOS seems to set the delegate interface only once, upon the *creation* of the VPN tunnel. If a network transition (e.g. from Wi-Fi to Cellular) happens while the tunnel is connected, it will be ignored and we will still try to set Wi-Fi as the default route because the delegated interface is not getting updated as connectivity transitions.

Here we work around this on the Swift side with a NWPathMonitor instance that observes the interface name of the first currently satisfied network path. Our Swift code will call into `UpdateLastKnownDefaultRouteInterface`, so we can rely on that when it is set.

If for any reason the Swift machinery didn't work and we don't get any updates, here we also have some fallback logic: we try finding a hardcoded Wi-Fi interface called en0. If en0 is down, we fall back to cellular (pdp_ip0) as a last resort. This doesn't handle all edge cases like USB-Ethernet adapters or multiple Ethernet interfaces, but it is good enough to ensure connectivity isn't broken.

I tested this on iPhones and iPads running iOS 17.1 and it appears to work. Switching between different cellular plans on a dual SIM configuration also works (the interface name remains pdp_ip0).

Signed-off-by: Andrea Gottardo <andrea@tailscale.com>
10 months ago
Andrew Dunham fa3639783c net/portmapper: check returned epoch from PMP and PCP protocols
If the epoch that we see during a Probe is less than the existing epoch,
it means that the gateway has either restarted or reset its
configuration, and an existing mapping is no longer valid. Reset any
saved mapping(s) if we detect this case so that a future
createOrGetMapping will not attempt to re-use it.

Updates #10597

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ie3cddaf625cb94a29885f7a1eeea25dbf6b97b47
10 months ago
Andrew Lytvynov 2716250ee8
all: cleanup unused code, part 2 (#10670)
And enable U1000 check in staticcheck.

Updates #cleanup

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
11 months ago
Nick Khyl c9836b454d net/netmon: fix goroutine leak in winMon if the monitor is never started
When the portable Monitor creates a winMon via newOSMon, we register
address and route change callbacks with Windows. Once a callback is hit,
it starts a goroutine that attempts to send the event into messagec and returns.
The newly started goroutine then blocks until it can send to the channel.
However, if the monitor is never started and winMon.Receive is never called,
the goroutines remain indefinitely blocked, leading to goroutine leaks and
significant memory consumption in the tailscaled service process on Windows.
Unlike the tailscaled subprocess, the service process creates but never starts
a Monitor.

This PR adds a check within the callbacks to confirm the monitor's active status,
and exits immediately if the monitor hasn't started.

Updates #9864

Signed-off-by: Nick Khyl <nickk@tailscale.com>
11 months ago
Andrew Lytvynov 1302bd1181
all: cleanup unused code, part 1 (#10661)
Run `staticcheck` with `U1000` to find unused code. This cleans up about
a half of it. I'll do the other half separately to keep PRs manageable.

Updates #cleanup

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
11 months ago