Commit Graph

398 Commits

Author SHA1 Message Date
Brad Fitzpatrick
35bee36549 portlist: use win32 calls instead of running netstat process [windows]
Turns out using win32 instead of shelling out to child processes is a
bit faster:

    name                  old time/op    new time/op    delta
    GetListIncremental-4     278ms ± 2%       0ms ± 7%  -99.93%  (p=0.000 n=8+10)

    name                  old alloc/op   new alloc/op   delta
    GetListIncremental-4     238kB ± 0%       9kB ± 0%  -96.12%  (p=0.000 n=10+8)

    name                  old allocs/op  new allocs/op  delta
    GetListIncremental-4     1.19k ± 0%     0.02k ± 0%  -98.49%  (p=0.000 n=10+10)

Fixes #3876 (sadly)

Change-Id: I1195ac5de21a8a8b3cdace5871d263e81aa27e91
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-10-25 10:55:25 -07:00
Brad Fitzpatrick
3697609aaa portlist: remove unix.Readlink allocs on Linux
name       old time/op    new time/op    delta
    GetList-8    11.2ms ± 5%    11.1ms ± 3%     ~     (p=0.661 n=10+9)

    name       old alloc/op   new alloc/op   delta
    GetList-8    83.3kB ± 1%    67.4kB ± 1%  -19.05%  (p=0.000 n=10+10)

    name       old allocs/op  new allocs/op  delta
    GetList-8     2.89k ± 2%     2.19k ± 1%  -24.24%  (p=0.000 n=10+10)

(real issue is we're calling this code as much as we are, but easy
enough to make it efficient because it'll still need to be called
sometimes in any case)

Updates #5958

Change-Id: I90c20278d73e80315a840aed1397d24faa308d93
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-10-22 11:30:53 -07:00
Mihai Parparita
9d04ffc782 net/wsconn: add back custom wrapper for turning a websocket.Conn into a net.Conn
We removed it in #4806 in favor of the built-in functionality from the
nhooyr.io/websocket package. However, it has an issue with deadlines
that has not been fixed yet (see nhooyr/websocket#350). Temporarily
go back to using a custom wrapper (using the fix from our fork) so that
derpers will stop closing connections too aggressively.

Updates #5921

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2022-10-18 15:39:32 -07:00
Joe Tsai
f9120eee57
wgengine: start network logger in Userspace.Reconfig (#5908)
If the wgcfg.Config is specified with network logging arguments,
then Userspace.Reconfig starts up an asynchronous network logger,
which is shutdown either upon Userspace.Close or when Userspace.Reconfig
is called again without network logging or route arguments.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2022-10-12 15:05:21 -07:00
Anton Tolchanov
c070d39287 cmd/tailscaled: handle tailscaled symlink on macOS
When Tailscale is installed via Homebrew, `/usr/local/bin/tailscaled`
is a symlink to the actual binary.

Now when `tailscaled install-system-daemon` runs, it will not attempt
to overwrite that symlink if it already points to the tailscaled binary.
However, if executed binary and the link target differ, the path will
he overwritten - this can happen when a user decides to replace
Homebrew-installed tailscaled with a one compiled from source code.

Fixes #5353

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
2022-10-11 16:09:26 +01:00
Emmanuel T Odeke
680f8d9793 all: fix more resource leaks found by staticmajor
Updates #5706

Signed-off-by: Emmanuel T Odeke <emmanuel@orijtech.com>
2022-10-10 20:46:56 -07:00
Joe Tsai
24ebf161e8
net/tstun: instrument Wrapper with statistics gathering (#5847)
If Wrapper.StatisticsEnable is enabled,
then per-connection counters are maintained.
If enabled, Wrapper.StatisticsExtract must be periodically called
otherwise there is unbounded memory growth.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2022-10-05 12:24:30 -07:00
Andrew Dunham
e5636997c5
wgengine: don't re-allocate trimmedNodes map (#5825)
Change-Id: I512945b662ba952c47309d3bf8a1b243e05a4736
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
2022-10-04 13:20:09 -04:00
Mihai Parparita
8343b243e7 all: consistently initialize Logf when creating tsdial.Dialers
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>
2022-09-30 14:40:56 -07:00
Josh Soref
d4811f11a0 all: fix spelling mistakes
Signed-off-by: Josh Soref <2119212+jsoref@users.noreply.github.com>
2022-09-29 13:36:13 -07:00
Aaron Klotz
44f13d32d7 cmd/tailscaled, util/winutil: log Windows service diagnostics when the wintun device fails to install
I added new functions to winutil to obtain the state of a service and all
its depedencies, serialize them to JSON, and write them to a Logf.

When tstun.New returns a wrapped ERROR_DEVICE_NOT_AVAILABLE, we know that wintun
installation failed. We then log the service graph rooted at "NetSetupSvc".
We are interested in that specific service because network devices will not
install if that service is not running.

Updates https://github.com/tailscale/tailscale/issues/5531

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2022-09-28 16:09:10 -06:00
Brad Fitzpatrick
9bdf0cd8cd ipn/ipnlocal: add c2n /debug/{goroutines,prefs,metrics}
* and move goroutine scrubbing code to its own package for reuse
* bump capver to 45

Change-Id: I9b4dfa5af44d2ecada6cc044cd1b5674ee427575
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-09-26 11:16:38 -07:00
Andrew Dunham
b1867457a6
doctor: add package for running in-depth healthchecks; use in bugreport (#5413)
Change-Id: Iaa4e5b021a545447f319cfe8b3da2bd3e5e5782b
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
2022-09-26 13:07:28 -04:00
Brad Fitzpatrick
2c447de6cc cmd/tailscaled: use explicit equal sign in --port=$PORT in tailscaled.service
Personal preference (so it's obvious it's not a bool flag), but it
also matches the --state= before it.

Bonus: stop allowing PORT to sneak in extra flags to be passed as
their own arguments, as $FOO and ${FOO} expand differently. (${FOO} is
required to concat to strings)

Change-Id: I994626a5663fe0948116b46a971e5eb2c4023216
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-09-22 11:54:22 -07:00
Brad Fitzpatrick
41bb47de0e cmd/tailscaled: respect $PORT on all platforms, not just Linux
Updates #5114

Change-Id: I6c6e28c493d6a026a03088157d08f9fd182ef373
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-09-17 12:30:29 -07:00
Brad Fitzpatrick
3562b5bdfa envknob, health: support Synology, show parse errors in status
Updates #5114

Change-Id: I8ac7a22a511f5a7d0dcb8cac470d4a403aa8c817
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-09-17 08:42:41 -07:00
Brad Fitzpatrick
65c24b6334 envknob: generalize Windows tailscaled-env.txt support
ipnserver previously had support for a Windows-only environment
variable mechanism that further only worked when Windows was running
as a service, not from a console.

But we want it to work from tailscaed too, and we want it to work on
macOS and Synology. So move it to envknob, now that envknob can change
values at runtime post-init.

A future change will wire this up for more platforms, and do something
more for CLI flags like --port, which the bug was originally about.

Updates #5114

Change-Id: I9fd69a9a91bb0f308fc264d4a6c33e0cbe352d71
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-09-16 15:30:19 -07:00
Eng Zer Jun
f0347e841f refactor: move from io/ioutil to io and os packages
The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.

Reference: https://golang.org/doc/go1.16#ioutil
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
2022-09-15 21:45:53 -07:00
Brad Fitzpatrick
74674b110d envknob: support changing envknobs post-init
Updates #5114

Change-Id: Ia423fc7486e1b3f3180a26308278be0086fae49b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-09-15 15:04:02 -07:00
Brad Fitzpatrick
45a3de14a6 cmd/tailscaled, tailcfg, hostinfo: add flag to disable logging + support
As noted in #5617, our documented method of blocking log.tailscale.io
DNS no longer works due to bootstrap DNS.

Instead, provide an explicit flag (--no-logs-no-support) and/or env
variable (TS_NO_LOGS_NO_SUPPORT=true) to explicitly disable logcatcher
uploads. It also sets a bit on Hostinfo to say that the node is in that
mode so we can end any support tickets from such nodes more quickly.

This does not yet provide an easy mechanism for users on some
platforms (such as Windows, macOS, Synology) to set flags/env. On
Linux you'd used /etc/default/tailscaled typically. Making it easier
to set flags for other platforms is tracked in #5114.

Fixes #5617
Fixes tailscale/corp#1475

Change-Id: I72404e1789f9e56ec47f9b7021b44c025f7a373a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-09-13 11:47:36 -07:00
Brad Fitzpatrick
58abae1f83 net/dns/{publicdns,resolver}: add NextDNS DoH support
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>
2022-09-08 12:50:32 -07:00
Andrew Dunham
c72caa6672 wgengine/magicsock: use AF_PACKET socket + BPF to read disco messages
This is entirely optional (i.e. failing in this code is non-fatal) and
only enabled on Linux for now. Additionally, this new behaviour can be
disabled by setting the TS_DEBUG_DISABLE_AF_PACKET environment variable.

Updates #3824
Replaces #5474

Co-authored-by: Andrew Dunham <andrew@du.nham.ca>
Signed-off-by: David Anderson <danderson@tailscale.com>
2022-08-31 14:52:31 -07:00
James Tucker
ad1cc6cff9 wgengine: use Go API rather than UAPI for status
Signed-off-by: James Tucker <james@tailscale.com>
2022-08-29 15:38:16 -07:00
Brad Fitzpatrick
c66f99fcdc tailcfg, control/controlclient, ipn/ipnlocal: add c2n (control-to-node) system
This lets the control plane can make HTTP requests to nodes.

Then we can use this for future things rather than slapping more stuff
into MapResponse, etc.

Change-Id: Ic802078c50d33653ae1f79d1e5257e7ade4408fd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-08-29 15:18:40 -07:00
Maisem Ali
9197dd14cc net/dns: [win] add MagicDNS entries to etc/hosts
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>
2022-08-19 12:38:11 -05:00
Joe Tsai
03f7e4e577
util/hashx: move from sha256x (#5388) 2022-08-16 13:15:33 -07:00
Brad Fitzpatrick
766ea96adf cmd/tailscaled: enable hybrid netstack mode on openbsd too
Apparently OpenBSD can forward packets with manual configuration,

https://github.com/tailscale/tailscale/issues/2498#issuecomment-1114216999

But this makes it work by default. People doing things by hand can
set TS_DEBUG_WRAP_NETSTACK=0 in the environment.

Change-Id: Iee5f32252f83af2baa0ebbe3f20ce9fec5f29e96
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-08-15 14:48:15 -07:00
Joe Tsai
1f7479466e
util/deephash: use sha256x (#5339)
Switch deephash to use sha256x.Hash.

We add sha256x.HashString to efficiently hash a string.
It uses unsafe under the hood to convert a string to a []byte.
We also modify sha256x.Hash to export the underlying hash.Hash
for testing purposes so that we can intercept all hash.Hash calls.

Performance:

	name                 old time/op    new time/op    delta
	Hash-24                19.8µs ± 1%    19.2µs ± 1%  -3.01%  (p=0.000 n=10+10)
	HashPacketFilter-24    2.61µs ± 0%    2.53µs ± 1%  -3.01%  (p=0.000 n=8+10)
	HashMapAcyclic-24      31.3µs ± 1%    29.8µs ± 0%  -4.80%  (p=0.000 n=10+9)
	TailcfgNode-24         1.83µs ± 1%    1.82µs ± 2%    ~     (p=0.305 n=10+10)
	HashArray-24            344ns ± 2%     323ns ± 1%  -6.02%  (p=0.000 n=9+10)

The performance gains is not as dramatic as sha256x over sha256 due to:
1. most of the hashing already occurring through the direct memory hashing logic, and
2. what does not go through direct memory hashing is slowed down by reflect.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2022-08-11 17:44:09 -07:00
Brad Fitzpatrick
ec9d13bce5 hostinfo, net/netcheck: use CutPrefix
Updates #5309

Change-Id: I37e594cfd245784bf810c493de68a66d3ff20677
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-08-05 15:17:44 -07:00
Andrew Dunham
f0d6f173c9
net/netcheck: try ICMP if UDP is blocked (#5056)
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
2022-08-04 17:10:13 -04:00
Tom DNetto
f50043f6cb tka,types/key: remove dependency for tailcfg & types/ packages on tka
Following the pattern elsewhere, we create a new tka-specific types package for the types
that need to couple between the serialized structure types, and tka.

Signed-off-by: Tom DNetto <tom@tailscale.com>
2022-08-04 12:51:58 -07:00
Brad Fitzpatrick
4950fe60bd syncs, all: move to using Go's new atomic types instead of ours
Fixes #5185

Change-Id: I850dd532559af78c3895e2924f8237ccc328449d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-08-04 07:47:59 -07:00
Tom DNetto
4001d0bf25 assorted: plumb tka initialization & network-lock key into tailscaled
- A network-lock key is generated if it doesn't already exist, and stored in the StateStore. The public component is communicated to control during registration.
 - If TKA state exists on the filesystem, a tailnet key authority is initialized (but nothing is done with it for now).

Signed-off-by: Tom DNetto <tom@tailscale.com>
2022-08-03 14:51:47 -07:00
Brad Fitzpatrick
8725b14056 all: migrate more code code to net/netip directly
Instead of going through the tailscale.com/net/netaddr transitional
wrappers.

Updates #5162

Change-Id: I3dafd1c2effa1a6caa9b7151ecf6edd1a3fda3dd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-08-02 13:59:57 -07:00
Maisem Ali
eb32847d85 tailcfg: add CapabilityFileSharingTarget to identify FileTargets
This adds the inverse to CapabilityFileSharingSend so that senders can
identify who they can Taildrop to.

Updates #2101

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2022-08-02 13:52:10 -07:00
Brad Fitzpatrick
e1309e1323 all: require Go 1.19
Updates #5210

Change-Id: I2e950b4776636b4ea89b6566b60e4a87596a3a43
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-08-02 11:49:01 -07:00
Tom DNetto
47f91dd732 cmd/tailscale{,d}: update depaware
Signed-off-by: Tom DNetto <tom@tailscale.com>
2022-07-29 12:16:32 -07:00
Brad Fitzpatrick
acc3b7f259 go.mod: bump inet.af/wf, tidy
This removes inet.af/netaddr from go.{mod,sum}.

Updates #5162

Change-Id: I7121e9fbb96d036cf188c51f0b53731570252d69
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-07-28 14:50:50 -07:00
Brad Fitzpatrick
0a6aa75a2d cmd/tailscaled: add opt-in support for linking CLI into daemon
Doesn't help much, though.

    $ go install --tags=ts_include_cli ./cmd/tailscaled/
    $ ls -lh ~/go/bin/tailscaled
    -rwxr-xr-x 2 bradfitz bradfitz 34M Jul 27 11:00 /home/bradfitz/go/bin/tailscaled
    $ go install --tags= ./cmd/tailscaled/
    $ ls -lh ~/go/bin/tailscaled
    -rwxr-xr-x 1 bradfitz bradfitz 23M Jul 27 11:00 /home/bradfitz/go/bin/tailscaled
    $ ls -lh ~/go/bin/tailscale
    -rwxr-xr-x 1 bradfitz bradfitz 13M Jul 25 21:30 /home/bradfitz/go/bin/tailscale

Fixes #2233

Change-Id: I46bae91bb38eb47a76251c1b5c1e9e455fc234b6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-07-27 11:15:52 -07:00
Brad Fitzpatrick
a12aad6b47 all: convert more code to use net/netip directly
perl -i -npe 's,netaddr.IPPrefixFrom,netip.PrefixFrom,' $(git grep -l -F netaddr.)
    perl -i -npe 's,netaddr.IPPortFrom,netip.AddrPortFrom,' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPrefix,netip.Prefix,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPort,netip.AddrPort,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IP\b,netip.Addr,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPv6Raw\b,netip.AddrFrom16,g' $(git grep -l -F netaddr. )
    goimports -w .

Then delete some stuff from the net/netaddr shim package which is no
longer neeed.

Updates #5162

Change-Id: Ia7a86893fe21c7e3ee1ec823e8aba288d4566cd8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-07-25 21:53:49 -07:00
Brad Fitzpatrick
6a396731eb all: use various net/netip parse funcs directly
Mechanical change with perl+goimports.

Changed {Must,}Parse{IP,IPPrefix,IPPort} to their netip variants, then
goimports -d .

Finally, removed the net/netaddr wrappers, to prevent future use.

Updates #5162

Change-Id: I59c0e38b5fbca5a935d701645789cddf3d7863ad
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-07-25 21:12:28 -07:00
Brad Fitzpatrick
7eaf5e509f net/netaddr: start migrating to net/netip via new netaddr adapter package
Updates #5162

Change-Id: Id7bdec303b25471f69d542f8ce43805328d56c12
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-07-25 16:20:43 -07:00
Maisem Ali
9514ed33d2 go.mod: bump gvisor.dev/gvisor
Pick up https://github.com/google/gvisor/pull/7787

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2022-07-21 16:41:18 -07:00
Maisem Ali
4d0461f721 ipn/ipnlocal: logout ephemeral nodes on shutdown
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2022-07-19 11:29:31 -07:00
Brad Fitzpatrick
0d52674a84 net/tstun: diagnose /dev/net/tun fd leak, give better failure message
Updates #5029

Change-Id: Ibee5e0c9076fe764eb5d856d5ef8b09f4d0e2921
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-07-16 14:21:56 -07:00
Brad Fitzpatrick
505ca2750d cmd/tailscaled: fix Windows "Allow local LAN access" regression
3f686688a6 regressed the Windows beFirewallKillswitch code,
preventing the /firewall subprocess from running.

Fixes tailscale/corp#6063

Change-Id: Ibd105759e5fecfeffc54f587f8ddcd0f1cbc4dca
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-07-13 08:01:32 -07:00
Brad Fitzpatrick
6b71568eb7 util/cloudenv: add Azure support & DNS IPs
And rewrite cloud detection to try to do only zero or one metadata
discovery request for all clouds, only doing a first (or second) as
confidence increases. Work remains for Windows, but a start.

And add Cloud to tailcfg.Hostinfo, which helped with testing using
"tailcfg debug hostinfo".

Updates #4983 (Linux only)
Updates #4984

Change-Id: Ib03337089122ce0cb38c34f724ba4b4812bc614e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-06-30 17:03:46 -07:00
Brad Fitzpatrick
aa37aece9c ipn/ipnlocal, net/dns*, util/cloudenv: add AWS DNS support
And remove the GCP special-casing from ipn/ipnlocal; do it only in the
forwarder for *.internal.

Fixes #4980
Fixes #4981

Change-Id: I5c481e96d91f3d51d274a80fbd37c38f16dfa5cb
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-06-29 20:37:44 -07:00
Brad Fitzpatrick
88c2afd1e3 ipn/ipnlocal, net/dns*, util/cloudenv: specialize DNS config on Google Cloud
This does three things:

* If you're on GCP, it adds a *.internal DNS split route to the
  metadata server, so we never break GCP DNS names. This lets people
  have some Tailscale nodes on GCP and some not (e.g. laptops at home)
  without having to add a Tailnet-wide *.internal DNS route.
  If you already have such a route, though, it won't overwrite it.

* If the 100.100.100.100 DNS forwarder has nowhere to forward to,
  it forwards it to the GCP metadata IP, which forwards to 8.8.8.8.
  This means there are never errNoUpstreams ("upstream nameservers not set")
  errors on GCP due to e.g. mangled /etc/resolv.conf (GCP default VMs
  don't have systemd-resolved, so it's likely a DNS supremacy fight)

* makes the DNS fallback mechanism use the GCP metadata IP as a
  fallback before our hosted HTTP-based fallbacks

I created a default GCP VM from their web wizard. It has no
systemd-resolved.

I then made its /etc/resolv.conf be empty and deleted its GCP
hostnames in /etc/hosts.

I then logged in to a tailnet with no global DNS settings.

With this, tailscaled writes /etc/resolv.conf (direct mode, as no
systemd-resolved) and sets it to 100.100.100.100, which then has
regular DNS via the metadata IP and *.internal DNS via the metadata IP
as well. If the tailnet configures explicit DNS servers, those are used
instead, except for *.internal.

This also adds a new util/cloudenv package based on version/distro
where the cloud type is only detected once. We'll likely expand it in
the future for other clouds, doing variants of this change for other
popular cloud environments.

Fixes #4911

RELNOTES=Google Cloud DNS improvements

Change-Id: I19f3c2075983669b2b2c0f29a548da8de373c7cf
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-06-29 17:39:13 -07:00
Brad Fitzpatrick
13d0b8e6a4 control/controlclient, net/dnscache: use typed singleflight fork
Change-Id: I12be4c5a91ae3a812fe88d9b2d15526fdbb5a921
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-06-17 10:20:16 -07:00