Commit Graph

214 Commits

Author SHA1 Message Date
Nick Khyl e815ae0ec4 util/syspolicy, ipn/ipnlocal: update syspolicy package to utilize syspolicy/rsop
In this PR, we update the syspolicy package to utilize syspolicy/rsop under the hood,
and remove syspolicy.CachingHandler, syspolicy.windowsHandler and related code
which is no longer used.

We mark the syspolicy.Handler interface and RegisterHandler/SetHandlerForTest functions
as deprecated, but keep them temporarily until they are no longer used in other repos.

We also update the package to register setting definitions for all existing policy settings
and to register the Registry-based, Windows-specific policy stores when running on Windows.

Finally, we update existing internal and external tests to use the new API and add a few more
tests and benchmarks.

Updates #12687

Signed-off-by: Nick Khyl <nickk@tailscale.com>
2024-10-25 12:41:07 -05:00
Andrea Gottardo fd77965f23
net/tlsdial: call out firewalls blocking Tailscale in health warnings (#13840)
Updates tailscale/tailscale#13839

Adds a new blockblame package which can detect common MITM SSL certificates used by network appliances. We use this in `tlsdial` to display a dedicated health warning when we cannot connect to control, and a network appliance MITM attack is detected.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
2024-10-19 00:35:46 +00:00
Nick Khyl da40609abd util/syspolicy, ipn: add "tailscale debug component-logs" support
Fixes #13313
Fixes #12687

Signed-off-by: Nick Khyl <nickk@tailscale.com>
2024-10-08 18:11:23 -05:00
Andrea Gottardo 8a6f48b455
cli: add `tailscale dns query` (#13368)
Updates tailscale/tailscale#13326

Adds a CLI subcommand to perform DNS queries using the internal DNS forwarder and observe its internals (namely, which upstream resolvers are being used).

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
2024-09-24 20:18:45 +00:00
Irbe Krumina 209567e7a0
kube,cmd/{k8s-operator,containerboot},envknob,ipn/store/kubestore,*/depaware.txt: rename packages (#13418)
Rename kube/{types,client,api} -> kube/{kubetypes,kubeclient,kubeapi}
so that we don't need to rename the package on each import to
convey that it's kubernetes specific.

Updates#cleanup

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
2024-09-08 20:57:29 +01:00
Irbe Krumina d6dfb7f242
kube,cmd/{k8s-operator,containerboot},envknob,ipn/store/kubestore,*/depaware.txt: split out kube types (#13417)
Further split kube package into kube/{client,api,types}. This is so that
consumers who only need constants/static types don't have to import
the client and api bits.

Updates#cleanup

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
2024-09-08 19:06:07 +01:00
Irbe Krumina ecd64f6ed9
cmd/k8s-operator,kube: set app name for Kubernetes Operator proxies (#13410)
Updates tailscale/corp#22920

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
2024-09-08 05:48:38 +01:00
Kristoffer Dalby a2c42d3cd4 usermetric: add initial user-facing metrics
This commit adds a new usermetric package and wires
up metrics across the tailscale client.

Updates tailscale/corp#22075

Co-authored-by: Anton Tolchanov <anton@tailscale.com>
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2024-08-27 11:21:35 +02:00
Kristoffer Dalby 06c31f4e91 tsweb/varz: remove pprof
Updates tailscale/corp#22075

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2024-08-27 11:21:35 +02:00
Percy Wegmann d00d6d6dc2 go.mod: update to github.com/tailscale/netlink library that doesn't require vishvananda/netlink
After the upstream PR is merged, we can point directly at github.com/vishvananda/netlink
and retire github.com/tailscale/netlink.

See https://github.com/vishvananda/netlink/pull/1006

Updates #12298

Signed-off-by: Percy Wegmann <percy@tailscale.com>
2024-08-22 17:35:37 -05:00
Brad Fitzpatrick 696711cc17 all: switch to and require Go 1.23
Updates #12912

Change-Id: Ib4ae26eb5fb68ad2216cab4913811b94f7eed5b6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-08-22 12:31:08 -07:00
Kyle Carberry 6c852fa817 go.{mod,sum}: migrate from nhooyr.io/websocket to github.com/coder/websocket
Coder has just adopted nhooyr/websocket which unfortunately changes the import path.

`github.com/coder/coder` imports `tailscale.com/net/wsconn` which was still pointing
to `nhooyr.io/websocket`, but this change updates it.

See https://coder.com/blog/websocket

Updates #13154

Change-Id: I3dec6512472b14eae337ae22c5bcc1e3758888d5
Signed-off-by: Kyle Carberry <kyle@carberry.com>
2024-08-14 21:23:49 -07:00
Nick Khyl 67df9abdc6 util/syspolicy/setting: add package that contains types for the next syspolicy PRs
Package setting contains types for defining and representing policy settings.
It facilitates the registration of setting definitions using Register and RegisterDefinition,
and the retrieval of registered setting definitions via Definitions and DefinitionOf.
This package is intended for use primarily within the syspolicy package hierarchy,
and added in a preparation for the next PRs.

Updates #12687

Signed-off-by: Nick Khyl <nickk@tailscale.com>
2024-08-12 21:02:35 -05:00
Brad Fitzpatrick 6ca078c46e cmd/derper: move 204 handler from package main to derphttp
Updates #13038

Change-Id: I28a8284dbe49371cae0e9098205c7c5f17225b40
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-08-06 17:53:33 -07:00
Nick Khyl e21d8768f9 types/opt: add generic Value[T any] for optional values of any types
Updates #12736

Signed-off-by: Nick Khyl <nickk@tailscale.com>
2024-07-08 17:00:43 -05:00
Brad Fitzpatrick 210264f942 cmd/derper: clarify that derper and tailscaled need to be in sync
Fixes #12617

Change-Id: Ifc87b7d9cf699635087afb57febd01fb9a6d11b7
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-06-26 19:46:42 -07:00
Brad Fitzpatrick 6b801a8e9e cmd/derper: link to various derper docs in more places
In hopes it'll be found more.

Updates tailscale/corp#20844

Change-Id: Ic92ee9908f45b88f8770de285f838333f9467465
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-06-26 19:46:35 -07:00
James Tucker 46fda6bf4c cmd/derper: add some DERP diagnostics pointers
A few other minor language updates.

Updates tailscale/corp#20844

Change-Id: Idba85941baa0e2714688cc8a4ec3e242e7d1a362
Signed-off-by: James Tucker <james@tailscale.com>
2024-06-26 19:18:28 -07:00
Brad Fitzpatrick 3485e4bf5a derp: make RunConnectionLoop funcs take Messages, support PeerPresentFlags
PeerPresentFlags was added in 5ffb2668ef but wasn't plumbed through to
the RunConnectionLoop. Rather than add yet another parameter (as
IP:port was added earlier), pass in the raw PeerPresentMessage and
PeerGoneMessage struct values, which are the same things, plus two
fields: PeerGoneReasonType for gone and the PeerPresentFlags from
5ffb2668ef.

Updates tailscale/corp#17816

Change-Id: Ib19d9f95353651ada90656071fc3656cf58b7987
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-06-25 09:47:25 -07:00
Aaron Klotz 7dd76c3411 net/netns: add Windows support for bind-to-interface-by-route
This is implemented via GetBestInterfaceEx. Should we encounter errors
or fail to resolve a valid, non-Tailscale interface, we fall back to
returning the index for the default interface instead.

Fixes #12551

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2024-06-24 10:43:34 -06:00
Brad Fitzpatrick 91786ff958 cmd/derper: add debug endpoint to adjust mutex profiling rate
Updates #3560

Change-Id: I474421ce75c79fb66e1c306ed47daebc5a0e069e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-06-24 09:05:31 -07:00
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>
2024-06-16 15:25:23 -07:00
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>
2024-06-16 08:38:45 -07:00
Aaron Klotz bd2a6d5386 util/winutil: add UserProfile type for (un)loading user profiles
S4U logons do not automatically load the associated user profile. In this
PR we add UserProfile to handle that part. Windows docs indicate that
we should try to resolve a remote profile path when present, so we attempt
to do so when the local computer is joined to a domain.

Updates #12383

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2024-06-14 11:02:01 -06:00
Brad Fitzpatrick ccdd2e6650 cmd/derper: add a README
Updates tailscale/corp#20844

Change-Id: Ie3ca5dd7f582f4f298339dd3cd2039243c204ef8
Co-authored-by: James Tucker <james@tailscale.com>
Co-authored-by: Maisem Ali <maisem@tailscale.com>
Co-authored-by: Andrew Dunham <andrew@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-06-12 20:12:41 -07:00
Aaron Klotz df86576989 util/winutil: add AllocateContiguousBuffer and SetNTString helper funcs
AllocateContiguousBuffer is for allocating structs with trailing buffers
containing additional data. It is to be used for various Windows structures
containing pointers to data located immediately after the struct.

SetNTString performs in-place setting of windows.NTString and
windows.NTUnicodeString.

Updates #12383

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2024-06-10 09:39:37 -06:00
Maisem Ali 9a64c06a20 all: do not depend on the testing package
Discovered while looking for something else.

Updates tailscale/corp#18935

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2024-05-24 05:23:36 -07:00
Brad Fitzpatrick 3c9be07214 cmd/derper: support TXT-mediated unpublished bootstrap DNS rollouts
Updates tailscale/coral#127

Change-Id: I2712c50630d0d1272c30305fa5a1899a19ffacef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-05-22 12:03:38 -07:00
Brad Fitzpatrick 15fc6cd966 derp/derphttp: fix netcheck HTTPS probes
The netcheck client, when no UDP is available, probes distance using
HTTPS.

Several problems:

* It probes using /derp/latency-check.
* But cmd/derper serves the handler at /derp/probe
* Despite the difference, it work by accident until c8f4dfc8c0
  which made netcheck's probe require a 2xx status code.
* in tests, we only use derphttp.Handler, so the cmd/derper-installed
  mux routes aren't preesnt, so there's no probe. That breaks
  tests in airplane mode. netcheck.Client then reports "unexpected
  HTTP status 426" (Upgrade Required)

This makes derp handle both /derp/probe and /derp/latency-check
equivalently, and in both cmd/derper and derphttp.Handler standalone
modes.

I notice this when wgengine/magicsock TestActiveDiscovery was failing
in airplane mode (no wifi). It still doesn't pass, but it gets
further.

Fixes #11989

Change-Id: I45213d4bd137e0f29aac8bd4a9ac92091065113f
2024-05-03 08:24:24 -07:00
Brad Fitzpatrick 1fe0983f2d cmd/derper,tstest/nettest: skip network-needing test in airplane mode
Not buying wifi on a short flight is a good way to find tests
that require network. Whoops.

Updates #cleanup

Change-Id: Ibe678e9c755d27269ad7206413ffe9971f07d298
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-05-03 08:24:24 -07:00
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>
2024-04-28 07:34:52 -07:00
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>
2024-04-27 12:17:45 -07:00
Brad Fitzpatrick 6d69fc137f ipn/{ipnlocal,localapi},wgengine{,/magicsock}: plumb health.Tracker
Down to 25 health.Global users. After this remains controlclient &
net/dns & wgengine/router.

Updates #11874
Updates #4136

Change-Id: I6dd1856e3d9bf523bdd44b60fb3b8f7501d5dc0d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-04-26 09:43:28 -07:00
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>
2024-04-25 22:13:04 -07:00
Aaron Klotz 7132b782d4 hostinfo: use Distro field for distinguishing Windows Server builds
Some editions of Windows server share the same build number as their
client counterpart; we must use an additional field found in the OS
version information to distinguish between them.

Even though "Distro" has Linux connotations, it is the most appropriate
hostinfo field. What is Windows Server if not an alternate distribution
of Windows? This PR populates Distro with "Server" when applicable.

Fixes #11785

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2024-04-18 13:48:50 -06:00
dependabot[bot] 449be38e03
build(deps): bump google.golang.org/protobuf from 1.32.0 to 1.33.0 (#11410)
* build(deps): bump google.golang.org/protobuf from 1.32.0 to 1.33.0

Bumps google.golang.org/protobuf from 1.32.0 to 1.33.0.

---
updated-dependencies:
- dependency-name: google.golang.org/protobuf
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

* cmd/{derper,stund}: update depaware.txt

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

---------

Signed-off-by: dependabot[bot] <support@github.com>
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Andrew Lytvynov <awly@tailscale.com>
2024-04-17 10:24:31 -06:00
James Tucker 8fa3026614 tsweb: switch to fastuuid for request ID generation
Request ID generation appears prominently in some services cumulative
allocation rate, and while this does not eradicate this issue (the API
still makes UUID objects), it does improve the overhead of this API and
reduce the amount of garbage that it produces.

Updates tailscale/corp#18266
Updates tailscale/corp#19054

Signed-off-by: James Tucker <james@tailscale.com>
2024-04-09 14:05:20 -07:00
Charlotte Brandhorst-Satzkorn 14683371ee
tailscale: update tailfs file and package names (#11590)
This change updates the tailfs file and package names to their new
naming convention.

Updates #tailscale/corp#16827

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
2024-04-02 13:32:30 -07:00
Brad Fitzpatrick 1c259100b0 cmd/{derper,derpprobe}: add --version flag
Fixes #11582

Change-Id: If99fc1ab6b89d624fbb07bd104dd882d2c7b50b4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-04-02 12:48:07 -07:00
Andrew Dunham 34176432d6 cmd/derper, types/logger: move log filter to shared package
So we can use it in trunkd to quiet down the logs there.

Updates #5563

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ie3177dc33f5ad103db832aab5a3e0e4f128f973f
2024-03-07 11:05:03 -05:00
Percy Wegmann e324a5660f ipn: include full tailfs shares in ipn notifications
This allows the Mac application to regain access to restricted
folders after restarts.

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
2024-02-29 10:16:44 -06:00
James Tucker 0c5e65eb3f cmd/derper: apply TCP keepalive and timeout to TLS as well
I missed a case in the earlier patch, and so we're still sending 15s TCP
keepalive for TLS connections, now adjusted there too.

Updates tailscale/corp#17587
Updates #3363

Signed-off-by: James Tucker <james@tailscale.com>
2024-02-23 19:19:38 -08:00
James Tucker edbad6d274 cmd/derper: add user timeout and reduce TCP keepalive
The derper sends an in-protocol keepalive every 60-65s, so frequent TCP
keepalives are unnecessary. In this tuning TCP keepalives should never
occur for a DERP client connection, as they will send an L7 keepalive
often enough to always reset the TCP keepalive timer. If however a
connection does not receive an ACK promptly it will now be shutdown,
which happens sooner than it would with a normal TCP keepalive tuning.

This re-tuning reduces the frequency of network traffic from derp to
client, reducing battery cost.

Updates tailscale/corp#17587
Updates #3363

Signed-off-by: James Tucker <james@tailscale.com>
2024-02-22 11:22:08 -08:00
Brad Fitzpatrick 10d130b845 cmd/derper, derp, tailcfg: add admission controller URL option
So derpers can check an external URL for whether to permit access
to a certain public key.

Updates tailscale/corp#17693

Change-Id: I8594de58f54a08be3e2dbef8bcd1ff9b728ab297
Co-authored-by: Maisem Ali <maisem@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2024-02-21 16:57:45 -08:00
Percy Wegmann abab0d4197 tailfs: clean up naming and package structure
- Restyles tailfs -> tailFS
- Defines interfaces for main TailFS types
- Moves implemenatation of TailFS into tailfsimpl package

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
2024-02-09 20:00:42 -06:00
Percy Wegmann 993acf4475 tailfs: initial implementation
Add a WebDAV-based folder sharing mechanism that is exposed to local clients at
100.100.100.100:8080 and to remote peers via a new peerapi endpoint at
/v0/tailfs.

Add the ability to manage folder sharing via the new 'share' CLI sub-command.

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
2024-02-09 09:13:51 -06:00
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>
2024-02-07 18:10:15 -08:00
James Tucker 457102d070 go.mod: bump most deps for start of cycle
Plan9 CI is disabled. 3p dependencies do not build for the target.
Contributor enthusiasm appears to have ceased again, and no usage has
been made.

Skipped gvisor, nfpm, and k8s.

Updates #5794
Updates #8043

Signed-off-by: James Tucker <james@tailscale.com>
2024-01-19 16:51:39 -08:00
Joe Tsai c25968e1c5
all: make use of ctxkey everywhere (#10846)
Also perform minor cleanups on the ctxkey package itself.
Provide guidance on when to use ctxkey.Key[T] over ctxkey.New.
Also, allow for interface kinds because the value wrapping trick
also happens to fix edge cases with interfaces in Go.

Updates #cleanup

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2024-01-16 13:56:23 -08:00
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>
2024-01-08 16:22:33 -08:00