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>
The GitHub CodeQL scanner flagged the localapi's cert domain usage as a problem
because user input in the URL made it to disk stat checks.
The domain is validated against the ipnstate.Status later, and only
authenticated root/configured users can hit this, but add some
paranoia anyway.
Change-Id: I373ef23832f1d8b3a27208bc811b6588ae5a1ddd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
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>
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#5617Fixestailscale/corp#1475
Change-Id: I72404e1789f9e56ec47f9b7021b44c025f7a373a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
And put the rationale in the name too to save the callers the need for a comment.
Change-Id: I090f51b749a5a0641897ee89a8fb2e2080c8b782
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This is especially helpful as we launch newer DERPs over time, and older
clients have progressively out-of-date static DERP maps baked in. After
this, as long as the client has successfully connected once, it'll cache
the most recent DERP map it knows about.
Resolves an in-code comment from @bradfitz
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
This will be needed to support preauth-keys with network lock in the future,
so getting the core mechanics out of the way now.
Signed-off-by: Tom DNetto <tom@tailscale.com>
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>
Updates #5435
Based on the discussion in #5435, we can better support transactional data models
by making the underlying storage layer a parameter (which can be specialized for
the request) rather than a long-lived member of Authority.
Now that Authority is just an instantaneous snapshot of state, we can do things
like provide idempotent methods and make it cloneable, too.
Signed-off-by: Tom DNetto <tom@tailscale.com>
The CapabilityFileSharingTarget capability added by eb32847d85
is meant to control the ability to share with nodes not owned by the
current user, not to restrict all sharing (the coordination server is
not currently populating the capability at all)
Fixestailscale/corp#6669
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Needed to identify the node. A serverside-check the machine key (used
to authenticate the noise session) is that of the specified NodeID
ensures the authenticity of the request.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Hashing []any is slow since hashing of interfaces is slow.
Hashing of interfaces is slow since we pessimistically assume
that cycles can occur through them and start cycle tracking.
Drop the variadic signature of Update and fix callers to pass in
an anonymous struct so that we are hashing concrete types
near the root of the value tree.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
- 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>
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>
If the host only has RSA, use its RSA + generate ecdsa + ed25519, etc.
Perhaps fixes https://twitter.com/colek42c/status/1550554439299244032 and
something else that was reported.
Change-Id: I88dc475c8e3d95b6f25288ff7664b8e72655fd16
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Clients may have platform-specific metrics they would like uploaded
(e.g. extracted from MetricKit on iOS). Add a new local API endpoint
that allows metrics to be updated by a simple name/value JSON-encoded
struct.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Together with 06aa141632 this minimizes
the number of NEPacketTunnelNetworkSettings updates that we have to do,
and thus avoids Chrome interrupting outstanding requests due to
(perceived) network changes.
Updates #3102
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
And remove the GCP special-casing from ipn/ipnlocal; do it only in the
forwarder for *.internal.
Fixes#4980Fixes#4981
Change-Id: I5c481e96d91f3d51d274a80fbd37c38f16dfa5cb
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
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>
Client.SetExpirySooner isn't part of the state machine. Remove it from
the Client interface.
And fix a use of LocalBackend.cc without acquiring the lock that
guards that field.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
On DSM7 as a non-root user it'll run into problems.
And we haven't tested on DSM6, even though it might work, but I doubt
it.
Updates #3802
Updates tailscale/corp#5468
Change-Id: I75729042e4788f03f9eb82057482a44b319f04f3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We weren't wiring up netstack.Impl to the LocalBackend in some cases
on Windows. This fixes Windows 7 when run as a service.
Updates #4750 (fixes after pull in to corp repo)
Change-Id: I9ce51b797710f2bedfa90545776b7628c7528e99
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Also lazify SSHServer initialization to allow restarting the server on a
subsequent `tailscale up`
Updates #3802
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Ideally we would re-establish these sessions when tailscaled comes back
up, however we do not do that yet so this is better than leaking the
sessions.
Updates #3802
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Broken by 3dedcd1640 but we don't have CI coverage yet.
Updates #3157
Change-Id: Ie8e95ebd36264887fdeed16fc9f25a857d48124b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This fixes the "tailscale up --authkey=... --ssh" path (or any "up"
path that used Start instead of EditPrefs) which wasn't setting the
bit.
Updates #3802
Change-Id: Ifca532ec58296fedcedb5582312dfee884367ed7
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Currently, when SetNetInfo is called it sets the value on
hostinfo.NetInfo. However, when SetHostInfo is called it overwrites the
hostinfo field which may mean it also clears out the NetInfo it had just
received.
This commit stores NetInfo separately and combines it into Hostinfo as
needed so that control is always notified of the latest values.
Also, remove unused copies of Hostinfo from ipn.Status and
controlclient.Auto.
Updates #tailscale/corp#4824 (maybe fixes)
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Currently the ssh session isn't terminated cleanly, instead the packets
are just are no longer routed to the in-proc SSH server. This makes it
so that clients get a disconnection when the `RunSSH` pref changes to
`false`.
Updates #3802
Signed-off-by: Maisem Ali <maisem@tailscale.com>
No callers remain (last one was removed with
tailscale/corp@1c095ae08f), and it's
pretty esoteric.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
The Mac client was using it, but it had the effect of the `RouteAll`
("Use Tailscale subnets") pref always being enabled at startup,
regardless of the persisted value.
enforceDefaults was added to handle cases from ~2 years ago where
we ended up with persisted `"RouteAll": false` values in the keychain,
but that should no longer be a concern. New users will get the default
of it being enabled via `NewPrefs`.
There will be a corresponding Mac client change to stop passing in
enforceDefaults.
For #3962
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
The connections returned from SystemDial are automatically closed when
there is a major link change.
Also plumb through the dialer to the noise client so that connections
are auto-reset when moving from cellular to WiFi etc.
Updates #3363
Signed-off-by: Maisem Ali <maisem@tailscale.com>
No CLI support yet. Just the curl'able version if you know the peerapi
port. (like via a TSMP ping)
Updates #306
Change-Id: I0662ba6530f7ab58d0ddb24e3664167fcd1c4bcf
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I've done this a handful of times in the past and again today.
Time to make it a supported thing for the future.
Used while debugging tailscale/corp#4559 (macsys CLI issues)
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
For tests.
Now that we can always listen (whereas we used to fail prior to
a2c330c496), some goroutine leak
checks were failing in tests in another repo after that change.
Change-Id: Id95a4b71167eca61962a48616d79741b9991e0bc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The previous commit (1b89662eff) this for Android, but we can also use
this on any platform if we we would otherwise fail.
Change-Id: I4cd78b40e9e77fca5cc8e717dd48ac173101bed4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We intercept the peerapi port in netstack anyway, so there's no reason
the linux kernel on Android needs to know about it. It's only getting
in the way and causing problems for reasons we don't fully understand.
But we don't even need to understand it because it's not relevant
anymore.
Instead, provide a dummy net.Listener that just sits and blocks to
pacify the rest of the code that assumes it can be stuck in a
Listener.Accept call and call Listener.Close and Listener.Addr.
We'll likely do this for all platforms in the future, if/when we also
link in netstack on iOS.
Updates #4449
Updates #4293
Updates #3986
Change-Id: Ic2d3fe2f3cee60fc527356a3368830f17aeb75ae
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Two changes in one:
* make DoH upgrades an explicitly scheduled send earlier, when we come
up with the resolvers-and-delay send plan. Previously we were
getting e.g. four Google DNS IPs and then spreading them out in
time (for back when we only did UDP) but then later we added DoH
upgrading at the UDP packet layer, which resulted in sometimes
multiple DoH queries to the same provider running (each doing happy
eyeballs dialing to 4x IPs themselves) for each of the 4 source IPs.
Instead, take those 4 Google/Cloudflare IPs and schedule 5 things:
first the DoH query (which can use all 4 IPs), and then each of the
4 IPs as UDP later.
* clean up the dnstype.Resolver.Addr confusion; half the code was
using it as an IP string (as documented) as half was using it as
an IP:port (from some prior type we used), primarily for tests.
Instead, document it was being primarily an IP string but also
accepting an IP:port for tests, then add an accessor method on it
to get the IPPort and use that consistently everywhere.
Change-Id: Ifdd72b9e45433a5b9c029194d50db2b9f9217b53
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The default is still users can debug their own nodes. But like
cd916b728b did, this adds support for admins to grant additional
capabilities with the new tailcfg.CapabilityDebugPeer cap.
Updates #4217
Change-Id: Ifce3d9a1f8e8845797970a4f97b393194663d35f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Fail on unsupported platforms (must be Linux or macOS tailscaled with
WIP env) or when disabled by admin (with TS_DISABLE_SSH_SERVER=1)
Updates #3802
Change-Id: I5ba191ed0d8ba4ddabe9b8fc1c6a0ead8754b286
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
And rename to updateFilterLocked to prevent future mistakes.
Fixes#4427
Change-Id: I4d37b90027d5ff872a339ce8180f5723704848dc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Controlled by server-sent capability policy.
To be initially used for SSH servers to record sessions to other
nodes. Not yet productized into something user-accessible. (Notably,
the list of Taildrop targets from the sender side isn't augmented
yet.) This purely permits expanding the set of expands a node will
accept a drop from.
Updates #3802
Updates #4217
Change-Id: Id7a5bccd686490f8ef2cdc7dae7c07c440dc0085
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
tailcfg.PingResponse formalizes the TSMP & disco response message, and
controlclient is wired to send POST responses containing
tailcfg.PingResponse for TSMP and disco PingRequests.
Updates tailscale/corp#754
Signed-off-by: James Tucker <james@tailscale.com>
Remove the weird netstack -> tailssh dependency and instead have tailssh
register itself with ipnlocal when linked.
This makes tailssh.server a singleton, so we can have a global map of
all sessions.
Updates #3802
Change-Id: Iad5caec3a26a33011796878ab66b8e7b49339f29
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Currently peerIPs doesn't do any sorting of the routes it returns. This
is typically fine, however imagine the case of an HA subnet router
failover. When a route R moves from peer A to peer B, the output of
peerIPs changes. This in turn causes all the deephash check inside
wgengine to fail as the hashed value of [R1, R2] is different than
the hashed value of [R2, R1]. When the hash check failes, it causes
wgengine to reconfigure all routes in the OS. This is especially
problematic for macOS and iOS where we use the NetworkExtension.
This commit makes it that the peerIPs are always sorted when returned,
thus making the hash be consistent as long as the list of routes remains
static.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This defines a new magic IPv6 prefix, fd7a:115c:a1e0:b1a::/64, a
subset of our existing /48, where the final 32 bits are an IPv4
address, and the middle 32 bits are a user-chosen "site ID". (which
must currently be 0000:00xx; the top 3 bytes must be zero for now)
e.g., I can say my home LAN's "site ID" is "0000:00bb" and then
advertise its 10.2.0.0/16 IPv4 range via IPv6, like:
tailscale up --advertise-routes=fd7a:115c:a1e0:b1a::bb:10.2.0.0/112
(112 being /128 minuse the /96 v6 prefix length)
Then people in my tailnet can:
$ curl '[fd7a:115c:a1e0:b1a::bb:10.2.0.230]'
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" ....
Updates #3616, etc
RELNOTE=initial support for TS IPv6 addresses to route v4 "via" specific nodes
Change-Id: I9b49b6ad10410a24b5866b9fbc69d3cae1f600ef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Combine the code between `LocalBackend.CheckIPForwarding` and
`controlclient.ipForwardingBroken`.
Fixes#4300
Signed-off-by: Maisem Ali <maisem@tailscale.com>
While we rearrange/upstream things.
gliderlabs/ssh is forked into tempfork from our prior fork
at be8b7add40
x/crypto/ssh OTOH is forked at
https://github.com/tailscale/golang-x-crypto because it was gnarlier
to vendor with various internal packages, etc.
Its git history shows where it starts (2c7772ba30643b7a2026cbea938420dce7c6384d).
Updates #3802
Change-Id: I546e5cdf831cfc030a6c42557c0ad2c58766c65f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
When `setWgengineStatus` is invoked concurrently from multiple
goroutines, it is possible that the call invoked with a newer status is
processed before a call with an older status. e.g. a status that has
endpoints might be followed by a status without endpoints. This causes
unnecessary work in the engine and can result in packet loss.
This patch adds an `AsOf time.Time` field to the status to specifiy when the
status was calculated, which later allows `setWgengineStatus` to ignore
any status messages it receives that are older than the one it has
already processed.
Updates tailscale/corp#2579
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This adds a "tailscale nc" command that acts a bit like "nc", but
dials out via tailscaled via localapi.
This is a step towards a "tailscale ssh", as we'll use "tailscale nc"
as a ProxyCommand for in some cases (notably in userspace mode).
But this is also just useful for debugging & scripting.
Updates #3802
RELNOTE=tailscale nc
Change-Id: Ia5c37af2d51dd0259d5833d80264d3ad5f68446a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Also make IPPrefixSliceOf use Slice[netaddr.IPPrefix] as it also
provides additional functions besides the standard ones provided by
Slice[T].
Signed-off-by: Maisem Ali <maisem@tailscale.com>
We need to be able to provide the ability for the GUI clients to resolve and set
the exit node IP from an untrusted string, thus enabling the ability to specify
that information via enterprise policy.
This patch moves the relevant code out of the handler for `tailscale up`,
into a method on `Prefs` that may then be called by GUI clients.
We also update tests accordingly.
Updates https://github.com/tailscale/corp/issues/4239
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
And add a CapabilityVersion type, primarily for documentation.
This makes MapRequest.Version, RegisterRequest.Version, and
SetDNSRequest.Version all use the same version, which will avoid
confusing in the future if Register or SetDNS ever changed their
semantics on Version change. (Currently they're both always 1)
This will requre a control server change to allow a
SetDNSRequest.Version value other than 1 to be deployed first.
Change-Id: I073042a216e0d745f52ee2dbc45cf336b9f84b7c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Otherwise it would log warnings about an empty file.
```
stores.go:138: store.NewFileStore("/tmp/3777352782"): file empty; treating it like a missing file [warning]
```
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Also move KubeStore and MemStore into their own package.
RELNOTE: tsnet now supports providing a custom ipn.StateStore.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
For local dev testing initially. Product-wise, it'll probably only be
workable on the two unsandboxed builds.
Updates #3802
Change-Id: Ic352f966e7fb29aff897217d79b383131bf3f92b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I introduced a bug in 8fe503057d when unifying oneConnListener
implementations.
The NewOneConnListenerFrom API was easy to misuse (its Close method
closes the underlying Listener), and we did (via http.Serve, which
closes the listener after use, which meant we were close the peerapi's
listener, even though we only wanted its Addr)
Instead, combine those two constructors into one and pass in the Addr
explicitly, without delegating through to any Listener.
Change-Id: I061d7e5f842e0cada416e7b2dd62100d4f987125
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Don't make users map their system's "caddy" (or whatever) system user
to its userid. We can do that. Support either a uid or a username.
RELNOTE=TS_PERMIT_CERT_UID can contain a uid or username
Change-Id: I7451b537a5e118b818addf1353882291d5f0d07f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
e.g. the change to ipnlocal in this commit ultimately logs out:
{"logtail":{"client_time":"2022-02-17T20:40:30.511381153-08:00","server_time":"2022-02-18T04:40:31.057771504Z"},"type":"Hostinfo","val":{"GoArch":"amd64","Hostname":"tsdev","IPNVersion":"1.21.0-date.20220107","OS":"linux","OSVersion":"Debian 11.2 (bullseye); kernel=5.10.0-10-amd64"},"v":1}
Change-Id: I668646b19aeae4a2fed05170d7b279456829c844
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
(The name SSH_HostKeys is bad but SSHHostKeys is worse.)
Updates #3802
Change-Id: I2a889019c9e8b065b668dd58140db4fcab868a91
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Make tailssh ask LocalBackend for the SSH hostkeys, as we'll need to
distribute them to peers.
For now only the hacky use-same-as-actual-host mode is implemented.
Updates #3802
Change-Id: I819dcb25c14e42e6692c441186c1dc744441592b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We need to capture some tailnet-related information for some Docker
features we're building. This exposes the tailnet name and MagicDNS
information via `tailscale status --json`.
Fixestailscale/corp#3670
Signed-off-by: Ross Zurowski <ross@rosszurowski.com>
Our previous Hostinfo logging was all as a side effect of telling
control. And it got marked as verbose (as it was)
This adds a one-time Hostinfo logging that's not verbose, early in
start-up.
Change-Id: I1896222b207457b9bb12ffa7cf361761fa4d3b3a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I was about to add a third copy, so unify them now instead.
Change-Id: I3b93896aa1249b1250a6b1df4829d57717f2311a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Our current workaround made the user check too lax, thus allowing deleted
users. This patch adds a helper function to winutil that checks that the
uid's SID represents a valid Windows security principal.
Now if `lookupUserFromID` determines that the SID is invalid, we simply
propagate the error.
Updates https://github.com/tailscale/tailscale/issues/869
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
We're finding a bunch of host operating systems/firewalls interact poorly
with peerapi. We either get ICMP errors from the host or users need to run
commands to allow the peerapi port:
https://github.com/tailscale/tailscale/issues/3842#issuecomment-1025133727
... even though the peerapi should be an internal implementation detail.
Rather than fight the host OS & firewalls, this change handles the
server side of peerapi entirely in netstack (except on iOS), so it
never makes its way to the host OS where it might be messed with. Two
main downsides are:
1) netstack isn't as fast, but we don't really need speed for peerapi.
And actually, with fewer trips to/from the kernel, we might
actually make up for some of the netstack performance loss by
staying in userspace.
2) tcpdump / Wireshark etc packet captures will no longer see the peerapi
traffic. Oh well. Crawshaw's been wanting to add packet capture server
support to tailscaled, so we'll probably do that sooner now.
A future change might also then use peerapi for the client-side
(except on iOS).
Updates #3842 (probably fixes, as well as many exit node issues I bet)
Change-Id: Ibc25edbb895dc083d1f07bd3cab614134705aa39
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
So you can run Caddy etc as a non-root user and let it have access to
get certs.
Updates caddyserver/caddy#4541
Change-Id: Iecc5922274530e2b00ba107d4b536580f374109b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Disabled by default.
To use, run tailscaled with:
TS_SSH_ALLOW_LOGIN=you@bar.com
And enable with:
$ TAILSCALE_USE_WIP_CODE=true tailscale up --ssh=true
Then ssh [any-user]@[your-tailscale-ip] for a root bash shell.
(both the "root" and "bash" part are temporary)
Updates #3802
Change-Id: I268f8c3c95c8eed5f3231d712a5dc89615a406f0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
A new package can also later record/report which knobs are checked and
set. It also makes the code cleaner & easier to grep for env knobs.
Change-Id: Id8a123ab7539f1fadbd27e0cbeac79c2e4f09751
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
From Maisem's code review feedback where he mashed the merge
button by mistake.
Change-Id: I55abce036a6c25dc391250514983125dda10126c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This code was copied in a few places (Windows, Android), so unify it
and add tests.
Change-Id: Id0510c0f5974761365a2045279d1fb498feca11e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Fixes#3660
RELNOTE=MagicDNS now works over IPv6 when CGNAT IPv4 is disabled.
Change-Id: I001e983df5feeb65289abe5012dedd177b841b45
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This is for use by the Windows GUI client to log via when an
exit node is in use, so the logs don't go out via the exit node and
instead go directly, like tailscaled's. The dialer tried to do that
in the unprivileged GUI by binding to a specific interface, but the
"Internet Kill Switch" installed by tailscaled for exit nodes
precludes that from working and instead the GUI fails to dial out.
So, go through tailscaled (with a CONNECT request) instead.
Fixestailscale/corp#3169
Change-Id: I17a8efdc1d4b8fed53a29d1c19995592b651b215
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This moves the Windows-only initialization of the filelogger into
logpolicy. Previously we only did it when babysitting the tailscaled
subprocess, but this meant that log messages from the service itself
never made it to disk. Examples that weren't logged to disk:
* logtail unable to dial out,
* DNS flush messages from the service
* svc.ChangeRequest messages (#3581)
This is basically the same fix as #3571 but staying in the Logf type,
and avoiding build-tagged file (which wasn't quite a goal, but
happened and seemed nice)
Fixes#3570
Co-authored-by: Aaron Klotz <aaron@tailscale.com>
Change-Id: Iacd80c4720b7218365ec80ae143339d030842702
Make shrinkDefaultRoute a pure function.
Instead of calling interfaceRoutes, accept that information as parameters.
Hard-code those parameters in TestShrinkDefaultRoute.
Fixes#3580
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
One option was to just hide "offline" in the text output, but that
doesn't fix the JSON output.
The next option was to lie and say it's online in the JSON (which then
fixes the "offline" in the text output).
But instead, this sets the self node's "Online" to whether we're in an
active map poll.
Fixes#3564
Change-Id: I9b379989bd14655198959e37eec39bb570fb814a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
magicsock was hanging onto its netmap on logout,
which caused tailscale status to display partial
information about a bunch of zombie peers.
After logout, there should be no peers.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
I'm sick of this flaking. Even if this isn't the right fix, it
stops the alert fatigue.
Updates #3020
Change-Id: I4001c127d78f1056302f7741adec34210a72ee61
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
And it updates the build tag style on a couple files.
Change-Id: I84478d822c8de3f84b56fa1176c99d2ea5083237
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
fee2d9fad added support for cmd/tailscale to connect to IPNExtension.
It came in two parts: If no socket was provided, dial IPNExtension first,
and also, if dialing the socket failed, fall back to IPNExtension.
The second half of that support caused the integration tests to fail
when run on a machine that was also running IPNExtension.
The integration tests want to wait until the tailscaled instances
that they spun up are listening. They do that by dialing the new
instance. But when that dial failed, it was falling back to IPNExtension,
so it appeared (incorrectly) that tailscaled was running.
Hilarity predictably ensued.
If a user (or a test) explicitly provides a socket to dial,
it is a reasonable assumption that they have a specific tailscaled
in mind and don't want to fall back to IPNExtension.
It is certainly true of the integration tests.
Instead of adding a bool to Connect, split out the notion of a
connection strategy. For now, the implementation remains the same,
but with the details hidden a bit. Later, we can improve that.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
It's been a bunch of releases now since the TailscaleIPs slice
replacement was added.
Change-Id: I3bd80e1466b3d9e4a4ac5bedba8b4d3d3e430a03
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Allow users of CallbackRouter to supply a GetBaseConfig
implementation. This is expected to be used on Android,
which currently lacks both a) platform support for
Split-DNS and b) a way to retrieve the current DNS
servers.
iOS/macOS also use the CallbackRouter but have platform
support for SplitDNS, so don't need getBaseConfig.
Updates https://github.com/tailscale/tailscale/issues/2116
Updates https://github.com/tailscale/tailscale/issues/988
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
To make ExitDNS cheaper.
Might not finish client-side support in December before 1.20, but at
least server support can start rolling out ahead of clients being
ready for it.
Tested with curl against peerapi.
Updates #1713
Change-Id: I676fed5fb1aef67e78c542a3bc93bddd04dd11fe
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If the user has a "Taildrop" shared folder on startup and
the "tailscale" system user has read/write access to it,
then the user can "tailscale file cp" to their NAS.
Updates #2179 (would be fixes, but not super ideal/easy yet)
Change-Id: I68e59a99064b302abeb6d8cc84f7d2a09f764990
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
And simplify, unexport some tsdial/netstack stuff in the the process.
Fixes#3475
Change-Id: I186a5a5cbd8958e25c075b4676f7f6e70f3ff76e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The control plane is currently still eating it.
Updates #1713
Change-Id: I66a0698599d6794ab1302f9585bf29e38553c884
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This starts to refactor tsdial.Dialer's name resolution to have
different stages: in-memory MagicDNS vs system resolution. A future
change will plug in ExitDNS resolution.
This also plumbs a Dialer into netstack and unexports the dnsMap
internals.
And it removes some of the async AddNetworkMapCallback usage and
replaces it with synchronous updates of the Dialer's netmap
from LocalBackend, since the LocalBackend has the Dialer too.
Updates #3475
Change-Id: Idcb7b1169878c74f0522f5151031ccbc49fe4cb4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Without this, enabling an exit node immediately blackholes all traffic,
but doesn't correctly let it flow to the exit node until the next netmap
update.
Fixes#3447
Signed-off-by: David Anderson <danderson@tailscale.com>
In prep for moving stuff out of LocalBackend.
Change-Id: I9725aa9c3ebc7275f8c40e040b326483c0340127
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Not done yet, but this move more of the outbound dial special casing
from random packages into tsdial, which aspires to be the one unified
place for all outbound dialing shenanigans.
Then this plumbs it all around, so everybody is ultimately
holding on to the same dialer.
As of this commit, macOS/iOS using an exit node should be able to
reach to the exit node's DoH DNS proxy over peerapi, doing the sockopt
to stay within the Network Extension.
A number of steps remain, including but limited to:
* move a bunch more random dialing stuff
* make netstack-mode tailscaled be able to use exit node's DNS proxy,
teaching tsdial's resolver to use it when an exit node is in use.
Updates #1713
Change-Id: I1e8ee378f125421c2b816f47bc2c6d913ddcd2f5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
So Taildrop sends work even if the local tailscaled is running in
netstack mode, as it often is on Synology, etc.
Updates #2179 (which is primarily about receiving, but both important)
Change-Id: I9bd1afdc8d25717e0ab6802c7cf2f5e0bd89a3b2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Don't be a DoH DNS server to peers unless the Tailnet admin has permitted
that peer autogroup:internet access.
Updates #1713
Change-Id: Iec69360d8e4d24d5187c26904b6a75c1dabc8979
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If IP forwarding is disabled globally, but enabled per-interface on all interfaces,
don't complain. If only some interfaces have forwarding enabled, warn that some
subnet routing/exit node traffic may not work.
Fixes#1586
Signed-off-by: David Anderson <danderson@tailscale.com>
We were missing an argument here.
Also, switch to %q, in case anything weird
is happening with these strings.
Updates tailscale/corp#461
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
And annotate magicsock as a start.
And add localapi and debug handlers with the Prometheus-format
exporter.
Updates #3307
Change-Id: I47c5d535fe54424741df143d052760387248f8d3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Was done as part of e6fbc0cd54 for ssh
work, but wasn't committed yet. Including it here both to minimize the
ssh diff size, and because I need it for a separate change.
Change-Id: If6eb54a2ca7150ace96488ed14582c2c05ca3422
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
More work towards removing the massive ipnserver.Run and ipnserver.Options
and making composable pieces.
Work remains. (The getEngine retry loop on Windows complicates things.)
For now some duplicate code exists. Once the Windows side is fixed
to either not need the retry loop or to move the retry loop into a
custom wgengine.Engine wrapper, then we can unify tailscaled_windows.go
too.
Change-Id: If84d16e3cd15b54ead3c3bb301f27ae78d055f80
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Fixes regression from 81cabf48ec which made
all map errors be sent to the frontend UI.
Fixes#3230
Change-Id: I7f142c801c7d15e268a24ddf901c3e6348b6729c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
For debugging Synology. Like the existing goroutines handler, in that
it's owner-only.
Change-Id: I852f0626be8e1c0b6794c1e062111d14adc3e6ac
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
github.com/go-multierror/multierror served us well.
But we need a few feature from it (implement Is),
and it's not worth maintaining a fork of such a small module.
Instead, I did a clean room implementation inspired by its API.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
At least until js/wasm starts using browser LocalStorage or something.
But for the foreseeable future, any login from a browser should
be considered ephemeral as the tab can close at any time and lose
the wireguard key, never to be seen again.
Updates #3157
Change-Id: I6c410d86dc7f9f233c3edd623313d9dee2085aac
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
So future refactors can only deal with a net.Listener and
be unconcerned with their caller's (Windows-specific) struggles.
Change-Id: I0af588b9a769ab65c59b0bd21f8a0c99abfa1784
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I'll keep ipnserver.Run for compatibility, but it'll be a wrapper
around several smaller pieces. (more testable too)
For now, start untangling some things in preparation.
Plan is to have to have a constructor for the just-exported
ipnserver.Server type that takes a LocalBackend and can
accept (in a new method) on a provided listener.
Change-Id: Ide73aadaac1a82605c97a2af1321d0d8f60b2a8c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It's all opaque, there's no constructor, and no exported
methods, so it's useless at this point, but this is one
small refactoring step.
Change-Id: Id961e8880cf0c84f1a0a989eefff48ecb3735add
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Moving this information into a centralized place so that it is accessible to
code in subsequent commits.
Updates #3011
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
The "go generate" command blindly looks for "//go:generate" anywhere
in the file regardless of whether it is truly a comment.
Prevent this false positive in cloner.go by mangling the string
to look less like "//go:generate".
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
From https://github.com/tailscale/tailscale/pull/1919 with
edits by bradfitz@.
This change introduces a new storage provider for the state file. It
allows users to leverage AWS SSM parameter store natively within
tailscaled, like:
$ tailscaled --state=arn:aws:ssm:eu-west-1:123456789:parameter/foo
Known limitations:
- it is not currently possible to specific a custom KMS key ID
RELNOTE=tailscaled on Linux supports using AWS SSM for state
Edits-By: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Maxime VISONNEAU <maxime.visonneau@gmail.com>
iOS and Android no longer use these. They both now (as of today)
use the hostinfo.SetFoo setters instead.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Turns out the iOS client has been only sending the OS version it first
started at. This whole hostinfo-via-prefs mechanism was never a good idea.
Start removing it.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This fixes "tailscale cert" on Synology where the var directory is
typically like /volume2/@appdata/Tailscale, or any other tailscaled
user who specifies a non-standard state file location.
This is a interim fix on the way to #2932.
Fixes#2927
Updates #2932
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We unconditionally set appropriate perms on the statefile dir.
We look at the basename of the statefile dir, and if it is "tailscale", then
we set perms as appropriate.
Fixes#2925
Updates #2856
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
This was already possible on Linux if you ran tailscaled with --debug
(which runs net/http/pprof), but it requires the user have the Go
toolchain around.
Also, it wasn't possible on macOS, as there's no way to run the IPNExtension
with a debug server (it doesn't run tailscaled).
And on Windows it's super tedious: beyond what users want to do or
what we want to explain.
Instead, put it in "tailscale debug" so it works and works the same on
all platforms. Then we can ask users to run it when we're debugging something
and they can email us the output files.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
ProgramData has a permissive ACL. For us to safely store machine-wide
state information, we must set a more restrictive ACL on our state directory.
We set the ACL so that only talescaled's user (ie, LocalSystem) and the
Administrators group may access our directory.
We must include Administrators to ensure that logs continue to be easily
accessible; omitting that group would force users to use special tools to
log in interactively as LocalSystem, which is not ideal.
(Note that the ACL we apply matches the ACL that was used for LocalSystem's
AppData\Local).
There are two cases where we need to reset perms: One is during migration
from the old location to the new. The second case is for clean installations
where we are creating the file store for the first time.
Updates #2856
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
tailscale-ipn.exe (the GUI) shouldn't use C:\ProgramData.
Also, migrate the earlier misnamed wg32/wg64 conf files if they're present.
(That was stopped in 2db877caa3, but the
files exist from fresh 1.14 installs)
Updates #2856
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
C:\WINDOWS\system32\config\systemprofile\AppData\Local\
is frequently cleared for almost any reason: Windows updates,
System Restore, even various System Cleaner utilities.
The server-state.conf file in AppData\Local could be deleted
at any time, which would break login until the node is removed
from the Admin Panel allowing it to create a new key.
Carefully copy any AppData state to ProgramData at startup.
If copying the state fails, continue to use AppData so at
least there will be connectivity. If there is no state,
use ProgramData.
We also migrate the log.conf file. Very old versions of
Tailscale named the EXE tailscale-ipn, so the log conf was
tailscale-ipn.log.conf and more recent versions preserved
this filename and cmdName in logs. In this migration we
always update the filename to
c:\ProgramData\Tailscale\tailscaled.log.conf
Updates https://github.com/tailscale/tailscale/issues/2856
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
So if the control plane knows that something's broken about the node, it can
include problem(s) in MapResponse and "tailscale status" will show it.
(and GUIs in the future, as it's in ipnstate.Status/JSON)
This also bumps the MapRequest.Version, though it's not strictly
required. Doesn't hurt.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
LocalBackend.Shutdown's docs say:
> The backend can no longer be used after Shutdown returns.
Nevertheless, TestStateMachine blithely calls Shutdown, talks some smack,
and continues on, expecting things to work. Other uses of Shutdown
in the codebase are as intended.
Things mostly kinda work anyway, except that the wgengine.Engine has been
shut down, so calls to Reconfig fail. Those get logged:
> local.go:603: wgengine status error: engine closing; no status
but otherwise ignored.
However, the Reconfig failure caused one fewer call to pause/unpause
than normal. Now the assertCalls lines match the equivalent ones
earlier in the test.
I don't see an obvious correct replacement for Shutdown in the context
of this test; I'm not sure entirely what it is trying to accomplish.
It is possible that many of the tests remaining after the prior call
to Shutdown are now extraneous. They don't harm anything, though,
so err on the side of safety and leave them for now.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Use helpers and variadic functions to make the call sites
a lot easier to read, since they occur a lot.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Concurrent calls to LocalBackend.setWgengineStatus
could result in some of the status updates being dropped.
This was exacerbated by 92077ae78c,
which increases the probability of concurrent status updates,
causing test failures (tailscale/corp#2579).
It's going to take a bit of work to fix this test.
The ipnlocal state machine is difficult to reason about,
particularly in the face of concurrency.
We could fix the test trivially by throwing a new mutex around
setWgengineStatus to serialize calls to it,
but I'd like to at least try to do better than cosmetics.
In the meantime, commit the test.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Spelling out the command to run for every type
means that changing the command makes for a large, repetitive diff.
Stop doing that.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
In prep for other bug fixes & tests. It's hard to test when it was
intermingled into LocalBackend.authReconfig.
Now it's a pure function.
And rename variable 'uc' (user config?) to the since idiomatic
'prefs'.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We currently plumb full URLs for DNS resolvers from the control server
down to the client. But when we pass the values into the net/dns
package, we throw away any URL that isn't a bare IP. This commit
continues the plumbing, and gets the URL all the way to the built in
forwarder. (It stops before plumbing URLs into the OS configurations
that can handle them.)
For #2596
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
And in the process, fix the related confusing error messages from
pinging your own IP or hostname.
Fixes#2803
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
* Revert "Revert "types/key: add MachinePrivate and MachinePublic.""
This reverts commit 61c3b98a24.
Signed-off-by: David Anderson <danderson@tailscale.com>
* types/key: add ControlPrivate, with custom serialization.
ControlPrivate is just a MachinePrivate that serializes differently
in JSON, to be compatible with how the Tailscale control plane
historically serialized its private key.
Signed-off-by: David Anderson <danderson@tailscale.com>
Plumb throughout the codebase as a replacement for the mixed use of
tailcfg.MachineKey and wgkey.Private/Public.
Signed-off-by: David Anderson <danderson@tailscale.com>
And add health check errors to ipnstate.Status (tailscale status --json).
Updates #2746
Updates #2775
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The number of packet filters can grow very large,
so this log entry can be very large.
We can get the packet filter server-side,
so reduce verbosity here to just the number of filters present.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Now that we have the easier-to-parse go:build build tags,
it is straightforward to simplify them. Yay.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
magicsock makes multiple calls to Now per packet.
Move to mono.Now. Changing some of the calls to
use package mono has a cascading effect,
causing non-per-packet call sites to also switch.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
The fact that Hash returns a [sha256.Size]byte leaks details about
the underlying hash implementation. This could very well be any other
hashing algorithm with a possible different block size.
Abstract this implementation detail away by declaring an opaque type
that is comparable. While we are changing the signature of UpdateHash,
rename it to just Update to reduce stutter (e.g., deephash.Update).
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
With this, I can now:
* install Tailscale
* stop the GUI
* net stop Tailscale
* net start Tailscale
* tailscale up --unattended
(where the middle three steps simulate what would happen on a Windows
Server Core machine without a GUI)
Fixes#2137
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The localapi was double-unescaping: once by net/http populating
the URL, and once by ourselves later. We need to start with the raw
escaped URL if we're doing it ourselves.
Started to write a test but it got invasive. Will have to add those
tests later in a commit that's not being cherry-picked to a release
branch.
Fixes#2288
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Regression from 6d10655dc3, which added
UpdatePrefs but didn't write it out to disk.
I'd planned on adding tests to state_test.go which is why I'd earlier
added 46896a9311 to prepare for making
such persistence tests easier to write, but turns out state_test.go
didn't even test UpdatePrefs, so I'm staying out of there.
Instead, this is tested using integration tests.
Fixes#2321
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We can't access b.netMap without holding b.mu.
We already grabbed it earlier in the function with the lock held.
Introduced in Nov 2020 in 7ea809897d.
Discovered during stress testing.
Apparently it's a pretty rare?
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
After allowing for custom DERP maps, it's convenient to be able to see their latency in
netcheck. This adds a query to the local tailscaled for the current DERPMap.
Updates #1264
Signed-off-by: julianknodt <julianknodt@gmail.com>