Commit Graph

672 Commits

Author SHA1 Message Date
Brad Fitzpatrick
695df497ba wgengine/magicsock: delete peerMap.endpointForDiscoKey, remove remaining caller
The one remaining caller of peerMap.endpointForDiscoKey was making the
improper assumption that there's exactly 1 node with a given DiscoKey
in the network. That was the cause of #3088.

Now that all the other callers have been updated to not use
endpointForDiscoKey, there's no need to try to keep maintaining that
prone-to-misuse index.

Updates #3088

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-10-15 22:19:27 -07:00
Brad Fitzpatrick
04fd94acd6 wgengine/magicsock: remove endpointForDiscoKey call from handleDiscoMessage
A DiscoKey maps 1:n to endpoints. When we get a disco pong, we don't
necessarily know which endpoint sent it to us. Ask them all. There
will only usually be 1 (and in rare circumstances 2). So it's easier
to ask all two rather than building new maps from the random ping TxID
to its endpoint.

Updates #3088

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-10-15 21:59:15 -07:00
Brad Fitzpatrick
151b4415ca wgengine/magicsock: remove endpoint parameter from handlePingLocked
We can reply to a ping without knowing which exact node it's from.  As
long as it's in our netmap, it's safe to reply. If there's more than
one node with that discokey, it doesn't matter who we're relpying to.

Updates #3088

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-10-15 21:44:52 -07:00
Brad Fitzpatrick
d86081f353 wgengine/magicsock: add new discoInfo type for DiscoKey state, move some fields
As more prep for removing the false assumption that you're able to
map from DiscoKey to a single peer, move the lastPingFrom and lastPingTime
fields from the endpoint type to a new discoInfo type, effectively upgrading
the old sharedDiscoKey map (which only held a *[32]byte nacl precomputed key
as its value) to discoInfo which then includes that naclbox key.

Then start plumbing it into handlePing in prep for removing the need
for handlePing to take an endpoint parameter.

Updates #3088

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-10-15 20:48:44 -07:00
Brad Fitzpatrick
e5779f019e wgengine/magicsock: move temporary endpoint lookup later, add TODO to remove
Updates #3088

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-10-15 19:22:30 -07:00
Brad Fitzpatrick
36a07089ee wgengine/magicsock: remove redundant/wrong sharedDiscoKey delete
The pass just after in this method handles cleaning up sharedDiscoKey.
No need to do it wrong (assuming DiscoKey => 1 node) earlier.

Updates #3088

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-10-15 16:57:59 -07:00
Brad Fitzpatrick
3e80806804 wgengine/magicsock: pass src NodeKey to handleDiscoMessage for DERP disco msgs
And then use it to avoid another lookup-by-DiscoKey.

Updates #3088
2021-10-15 16:52:42 -07:00
Brad Fitzpatrick
82fa15fa3b wgengine/magicsock: start removing endpointForDiscoKey
It's not valid to assume that a discokey is globally unique.

This removes the first two of the four callers.

Updates #3088

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-10-15 16:44:02 -07:00
Avery Pennarun
0d4a0bf60e magicsock: if STUN failed to send before, rebind before STUNning again.
On iOS (and possibly other platforms), sometimes our UDP socket would
get stuck in a state where it was bound to an invalid interface (or no
interface) after a network reconfiguration. We can detect this by
actually checking the error codes from sending our STUN packets.

If we completely fail to send any STUN packets, we know something is
very broken. So on the next STUN attempt, let's rebind the UDP socket
to try to correct any problems.

This fixes a problem where iOS would sometimes get stuck using DERP
instead of direct connections until the backend was restarted.

Fixes #2994

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
2021-10-08 02:17:09 +09:00
David Anderson
830f641c6b wgengine/magicsock: update discokeys on netmap change.
Fixes #3008.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-10-06 14:52:47 -07:00
Josh Bleecher Snyder
a722e48cef wgengine/magicsock: skip alloc test with -race
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-09-17 09:56:32 -07:00
Brad Fitzpatrick
31c1331415 wgengine/magicsock: deflake TestReceiveFromAllocs
100 iterations isn't enough with background allocs happening
apparently. 1000 seems to be reliable.

Fixes #2826

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-09-09 11:49:44 -07:00
Brad Fitzpatrick
2238814b99 wgengine/magicsock: fix crash introduced in recent cleanups
Fixes #2801

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-09-08 08:27:51 -07:00
Brad Fitzpatrick
640134421e all: update tests to use tstest.MemLogger
And give MemLogger a mutex, as one caller had, which does match the logf
contract better.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-09-07 20:06:15 -07:00
David Anderson
efe8020dfa wgengine/magicsock: fix race condition in tests.
AFAICT this was always present, the log read mid-execution was never safe.
But it seems like the recent magicsock refactoring made the race much
more likely.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-09-05 17:42:33 -07:00
Brad Fitzpatrick
5bacbf3744 wgengine/magicsock, health, ipn/ipnstate: track DERP-advertised health
And add health check errors to ipnstate.Status (tailscale status --json).

Updates #2746
Updates #2775

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-09-02 10:20:25 -07:00
David Anderson
bb10443edf wgengine/wgcfg: use just the hexlified node key as the WireGuard endpoint.
The node key is all magicsock needs to find the endpoint that WireGuard
needs.

Updates #2752

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-09-01 15:13:21 -07:00
David Anderson
d00341360f wgengine/magicsock: remove unused debug knob.
Signed-off-by: David Anderson <danderson@tailscale.com>
2021-09-01 15:13:21 -07:00
David Anderson
dfd978f0f2 wgengine/magicsock: use NodeKey, not DiscoKey, as the trigger for lazy reconfig.
Updates #2752

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-09-01 15:13:21 -07:00
David Anderson
4c27e2fa22 wgengine/magicsock: remove Start method from Conn.
Over time, other magicsock refactors have made Start effectively a
no-op, except that some other functions choose to panic if called
before Start.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-09-01 15:13:21 -07:00
David Anderson
1a899344bd wgengine/magicsock: don't store tailcfg.Nodes alongside endpoints.
Updates #2752

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-09-01 15:13:21 -07:00
David Anderson
b2181608b5 wgengine/magicsock: eagerly create endpoints in SetNetworkMap.
Updates #2752

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-09-01 15:13:21 -07:00
Emmanuel T Odeke
0daa32943e all: add (*testing.B).ReportAllocs() to every benchmark
This ensures that we can properly track and catch allocation
slippages that could otherwise have been missed.

Fixes #2748
2021-08-30 21:41:04 -07:00
David Anderson
44d71d1e42 wgengine/magicsock: fix race in test shutdown, again.
We were returning an error almost, but not quite like errConnClosed in
a single codepath, which could still trip the panic on reconfig in the
test logic.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-08-30 21:26:38 -07:00
David Anderson
f09ede9243 wgengine/magicsock: don't configure eager WireGuard handshaking in tests.
Our prod code doesn't eagerly handshake, because our disco layer enables
on-demand handshaking. Configuring both peers to eagerly handshake leads
to WireGuard handshake races that make TestTwoDevicePing flaky.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-08-30 17:28:12 -07:00
David Anderson
86d1c4eceb wgengine/magicsock: ignore close races even harder.
Signed-off-by: David Anderson <danderson@tailscale.com>
2021-08-30 17:09:45 -07:00
David Anderson
8bacfe6a37 wgengine/magicsock: remove unused sendLogLimit limiter.
Magicsock these days gets its logs limited by the global log limiter.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-08-30 17:09:45 -07:00
David Anderson
e151b74f93 wgengine/magicsock: remove opts.SimulatedNetwork.
It only existed to override one test-only behavior with a
different test-only behavior, in both cases working around
an annoying feature of our CI environments. Instead, handle
that weirdness entirely in the test code, with a tweaked
TestOnlyPacketListener that gets injected.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-08-30 17:09:45 -07:00
David Anderson
58c1f7d51a wgengine/magicsock: rename opts.PacketListener to TestOnlyPacketListener.
The docstring said it was meant for use in tests, but it's specifically a
special codepath that is _only_ used in tests, so make the claim stronger.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-08-30 17:09:45 -07:00
David Anderson
8049063d35 wgengine/magicsock: rename discoEndpoint to just endpoint.
Signed-off-by: David Anderson <danderson@tailscale.com>
2021-08-30 17:09:45 -07:00
David Anderson
f2d949e2db wgengine/magicsock: fold findEndpoint into its only remaining caller.
Signed-off-by: David Anderson <danderson@tailscale.com>
2021-08-30 17:09:45 -07:00
David Anderson
fe2f89deab wgengine/magicsock: fix rare shutdown race in test.
Signed-off-by: David Anderson <danderson@tailscale.com>
2021-08-30 14:33:07 -07:00
David Anderson
97693f2e42 wgengine/magicsock: delete legacy AddrSet endpoints.
Instead of using the legacy codepath, teach discoEndpoint to handle
peers that have a home DERP, but no disco key. We can still communicate
with them, but only over DERP.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-08-30 14:33:07 -07:00
slowy07
ac0353e982 fix: typo spelling grammar
Signed-off-by: slowy07 <slowy.arfy@gmail.com>
2021-08-24 07:55:04 -07:00
Brad Fitzpatrick
37053801bb wgengine/magicsock: restore a bit of logging on node becoming active
Fixes #2695

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-08-23 12:22:23 -07:00
Brad Fitzpatrick
39610aeb09 wgengine/magicsock: move debug knobs to their own file, compile out on iOS
No need for these knobs on iOS where you can set the environment
variables anyway.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-08-15 13:21:22 -07:00
Brad Fitzpatrick
f3c96df162 ipn/ipnstate: move tailscale status "active" determination to tailscaled
Fixes #2579

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-08-04 09:10:49 -07:00
Brad Fitzpatrick
b622c60ed0 derp,wgengine/magicsock: don't assume stringer is in $PATH for go:generate
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-08-01 19:14:08 -07:00
Josh Bleecher Snyder
8a3d52e882 wgengine/magicsock: use mono.Time
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>
2021-07-29 12:56:58 -07:00
Josh Bleecher Snyder
4dbbd0aa4a cmd/addlicense: add command to add licenseheaders to generated code
And use it to make our stringer invocations match the existing code.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-07-19 15:31:56 -07:00
Josh Bleecher Snyder
c179580599 wgengine/magicsock: add debug envvar to force all traffic over DERP
This would have been useful during debugging DERP issues recently.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-07-19 15:30:50 -07:00
Josh Bleecher Snyder
4f4dae32dd wgengine/magicsock: fix latent data race in test
logBufWriter had no serialization.
It just so happens that none of its users currently ever log concurrently.
Make it safe for concurrent use.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-07-13 15:14:18 -07:00
Brad Fitzpatrick
7e7c4c1bbe tailcfg: break DERPNode.DERPTestPort into DERPPort & InsecureForTests
The DERPTestPort int meant two things before: which port to use, and
whether to disable TLS verification. Users would like to set the port
without disabling TLS, so break it into two options.

Updates #1264

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-07-09 12:30:31 -07:00
Brad Fitzpatrick
92077ae78c wgengine/magicsock: make portmapping async
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-07-09 11:15:26 -07:00
julianknodt
506c2fe8e2 cmd/tailscale: make netcheck use active DERP map, delete static copy
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>
2021-06-28 14:08:47 -07:00
David Crawshaw
5f8ffbe166 magicsock: add SetPreferredPort method
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
2021-06-23 08:51:37 -07:00
Josh Bleecher Snyder
ddf6c8c729 wgengine/magicsock: delete dead code
Co-authored-by: Adrian Dewhurst <adrian@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-05-28 17:02:08 -07:00
Josh Bleecher Snyder
1ece91cede go.mod: upgrade wireguard-windows, de-fork wireguard-go
Pull in the latest version of wireguard-windows.

Switch to upstream wireguard-go.
This requires reverting all of our import paths.

Unfortunately, this has to happen at the same time.
The wireguard-go change is very low risk,
as that commit matches our fork almost exactly.
(The only changes are import paths, CI files, and a go.mod entry.)
So if there are issues as a result of this commit,
the first place to look is wireguard-windows changes.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-05-25 13:18:21 -07:00
Josh Bleecher Snyder
25df067dd0 all: adapt to opaque netaddr types
This commit is a mishmash of automated edits using gofmt:

gofmt -r 'netaddr.IPPort{IP: a, Port: b} -> netaddr.IPPortFrom(a, b)' -w .
gofmt -r 'netaddr.IPPrefix{IP: a, Port: b} -> netaddr.IPPrefixFrom(a, b)' -w .

gofmt -r 'a.IP.Is4 -> a.IP().Is4' -w .
gofmt -r 'a.IP.As16 -> a.IP().As16' -w .
gofmt -r 'a.IP.Is6 -> a.IP().Is6' -w .
gofmt -r 'a.IP.As4 -> a.IP().As4' -w .
gofmt -r 'a.IP.String -> a.IP().String' -w .

And regexps:

\w*(.*)\.Port = (.*)  ->  $1 = $1.WithPort($2)
\w*(.*)\.IP = (.*)  ->  $1 = $1.WithIP($2)

And lots of manual fixups.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-05-16 14:52:00 -07:00
Josh Bleecher Snyder
ebcd7ab890 wgengine: remove wireguard-go DeviceOptions
We no longer need them.
This also removes the 32 bytes of prefix junk before endpoints.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-05-11 15:30:39 -07:00
Josh Bleecher Snyder
aacb2107ae all: add extra information to serialized endpoints
magicsock.Conn.ParseEndpoint requires a peer's public key,
disco key, and legacy ip/ports in order to do its job.
We currently accomplish that by:

* adding the public key in our wireguard-go fork
* encoding the disco key as magic hostname
* using a bespoke comma-separated encoding

It's a bit messy.

Instead, switch to something simpler: use a json-encoded struct
containing exactly the information we need, in the form we use it.

Our wireguard-go fork still adds the public key to the
address when it passes it to ParseEndpoint, but now the code
compensating for that is just a couple of simple, well-commented lines.
Once this commit is in, we can remove that part of the fork
and remove the compensating code.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-05-11 15:13:42 -07:00
Josh Bleecher Snyder
ddd85b9d91 wgengine/magicsock: rename discoEndpoint.wgEndpointHostPort to wgEndpoint
Fields rename only.

Part of the general effort to make our code agnostic about endpoint formatting.
It's just a name, but it will soon be a misleading one; be more generic.
Do this as a separate commit because it generates a lot of whitespace changes.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-05-06 12:44:22 -07:00
Josh Bleecher Snyder
e0bd3cc70c wgengine/magicsock: use netaddr.MustParseIPPrefix
Delete our bespoke helper.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-05-06 12:44:22 -07:00
Josh Bleecher Snyder
bc68e22c5b all: s/CreateEndpoint/ParseEndpoint/ in docs
Upstream wireguard-go renamed the interface method
from CreateEndpoint to ParseEndpoint.
I missed some comments. Fix them.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-05-06 12:44:22 -07:00
Josh Bleecher Snyder
a0dacba877 wgengine/magicsock: simplify legacy endpoint DstToString
Legacy endpoints (addrSet) currently reconstruct their dst string when requested.

Instead, store the dst string we were given to begin with.
In addition to being simpler and cheaper, this makes less code
aware of how to interpret endpoint strings.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-05-06 12:44:22 -07:00
Josh Bleecher Snyder
64047815b0 wgenengine/magicsock: delete cursed tests
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-05-03 11:09:44 -07:00
Josh Bleecher Snyder
7ee891f5fd all: delete wgcfg.Key and wgcfg.PrivateKey
For historical reasons, we ended up with two near-duplicate
copies of curve25519 key types, one in the wireguard-go module
(wgcfg) and one in the tailscale module (types/wgkey).
Then we moved wgcfg to the tailscale module.
We can now remove the wgcfg key type in favor of wgkey.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-29 14:14:34 -07:00
Josh Bleecher Snyder
9d542e08e2 wgengine/magicsock: always run ReceiveIPv6
One of the consequences of the 	bind refactoring in 6f23087175
is that attempting to bind an IPv6 socket will always
result in c.pconn6.pconn being non-nil.
If the bind fails, it'll be set to a placeholder packet conn
that blocks forever.

As a result, we can always run ReceiveIPv6 and health check it.
This removes IPv4/IPv6 asymmetry and also will allow health checks
to detect any IPv6 receive func failures.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-28 11:07:14 -07:00
Josh Bleecher Snyder
fe50ded95c health: track whether we have a functional udp4 bind
Suggested-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-28 11:07:14 -07:00
Josh Bleecher Snyder
7dc7078d96 wgengine/magicsock: use netaddr.IP in listenPacket
It must be an IP address; enforce that at the type level.

Suggested-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-28 11:07:14 -07:00
Josh Bleecher Snyder
3c543c103a wgengine/magicsock: unify initial bind and rebind
We had two separate code paths for the initial UDP listener bind
and any subsequent rebinds.

IPv6 got left out of the rebind code.
Rather than duplicate it there, unify the two code paths.
Then improve the resulting code:

* Rebind had nested listen attempts to try the user-specified port first,
  and then fall back to :0 if that failed. Convert that into a loop.
* Initial bind tried only the user-specified port.
  Rebind tried the user-specified port and 0.
  But there are actually three ports of interest:
  The one the user specified, the most recent port in use, and 0.
  We now try all three in order, as appropriate.
* In the extremely rare case in which binding to port 0 fails,
  use a dummy net.PacketConn whose reads block until close.
  This will keep the wireguard-go receive func goroutine alive.

As a pleasant side-effect of this, if we decide that
we need to resuscitate #1796, it will now be much easier.

Fixes #1799

Co-authored-by: David Anderson <danderson@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-28 10:39:28 -07:00
Josh Bleecher Snyder
8fb66e20a4 wgengine/magicsock: remove DefaultPort const
Assume it'll stay at 0 forever, so hard-code it
and delete code conditional on it being non-0.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-28 10:39:28 -07:00
Josh Bleecher Snyder
a8f61969b9 wgengine/magicsock: remove context arg from listenPacket
It was set to context.Background by all callers, for the same reasons.
Set it locally instead, to simplify call sites.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-28 10:39:28 -07:00
Josh Bleecher Snyder
744de615f1 health, wgenegine: fix receive func health checks for the fourth time
The old implementation knew too much about how wireguard-go worked.
As a result, it missed genuine problems that occurred due to unrelated bugs.

This fourth attempt to fix the health checks takes a black box approach.
A receive func is healthy if one (or both) of these conditions holds:

* It is currently running and blocked.
* It has been executed recently.

The second condition is required because receive functions
are not continuously executing. wireguard-go calls them and then
processes their results before calling them again.

There is a theoretical false positive if wireguard-go go takes
longer than one minute to process the results of a receive func execution.
If that happens, we have other problems.

Updates #1790

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-26 17:35:49 -07:00
Josh Bleecher Snyder
0d4c8cb2e1 health: delete ReceiveFunc health checks
They were not doing their job.
They need yet another conceptual re-think.
Start by clearing the decks.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-26 17:35:49 -07:00
Josh Bleecher Snyder
8d7f7fc7ce health, wgenegine: fix receive func health checks yet again
The existing implementation was completely, embarrassingly conceptually broken.

We aren't able to see whether wireguard-go's receive function goroutines
are running or not. All we can do is model that based on what we have done.
This commit fixes that model.

Fixes #1781

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-23 08:42:04 -07:00
Josh Bleecher Snyder
5835a3f553 health, wgengine/magicsock: avoid receive function false positives
Avery reported a sub-ms health transition from "receiveIPv4 not running" to "ok".

To avoid these transient false-positives, be more precise about
the expected lifetime of receive funcs. The problematic case is one in which
they were started but exited prior to a call to connBind.Close.
Explicitly represent started vs running state, taking care with the order of updates.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-22 12:48:10 -07:00
Josh Bleecher Snyder
f845aae761 health: track whether magicsock receive functions are running
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-22 08:57:36 -07:00
Josh Bleecher Snyder
48e30bb8de wgengine/magicsock: remove named return
Doesn't add anything.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-20 10:12:07 -07:00
Josh Bleecher Snyder
a2a2c0ce1c wgengine/magicsock: fix two comments
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-20 10:12:07 -07:00
Josh Bleecher Snyder
b1e624ef04 wgengine/magicsock: remove unnecessary type assertions
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-20 10:12:07 -07:00
Josh Bleecher Snyder
98714e784b wgengine/magicsock: improve Rebind logging
We were accidentally logging oldPort -> oldPort.

Log oldPort as well as c.port; if we failed to get the preferred port
in a previous rebind, oldPort might differ from c.port.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-20 10:12:07 -07:00
Josh Bleecher Snyder
15ceacc4c5 wgengine/magicsock: accept a host and port instead of an addr in listenPacket
This simplifies call sites and prevents accidental failure to use net.JoinHostPort.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
2021-04-20 10:12:07 -07:00
Brad Fitzpatrick
b993d9802a ipn/ipnlocal, etc: require file sharing capability to send/recv files
tailscale/corp#1582

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-04-16 10:58:19 -07:00
Brad Fitzpatrick
762180595d ipn/ipnstate: add PeerStatus.TailscaleIPs slice, deprecate TailAddr
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-04-14 08:12:31 -07:00
Brad Fitzpatrick
34d2f5a3d9 tailcfg: add Endpoint, EndpointType, MapRequest.EndpointType
Track endpoints internally with a new tailcfg.Endpoint type that
includes a typed netaddr.IPPort (instead of just a string) and
includes a type for how that endpoint was discovered (STUN, local,
etc).

Use []tailcfg.Endpoint instead of []string internally.

At the last second, send it to the control server as the existing
[]string for endpoints, but also include a new parallel
MapRequest.EndpointType []tailcfg.EndpointType, so the control server
can start filtering out less-important endpoint changes from
new-enough clients. Notably, STUN-discovered endpoints can be filtered
out from 1.6+ clients, as they can discover them amongst each other
via CallMeMaybe disco exchanges started over DERP. And STUN endpoints
change a lot, causing a lot of MapResposne updates. But portmapped
endpoints are worth keeping for now, as they they work right away
without requiring the firewall traversal extra RTT dance.

End result will be less control->client bandwidth. (despite negligible
increase in client->control bandwidth)

Updates tailscale/corp#1543

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-04-13 10:12:14 -07:00
Josh Bleecher Snyder
ba72126b72 wgengine/magicsock: remove RebindingUDPConn.FakeClosed
It existed to work around the frequent opening and closing
of the conn.Bind done by wireguard-go.
The preceding commit removed that behavior,
so we can simply close the connections
when we are done with them.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-04-03 10:32:51 -07:00
Josh Bleecher Snyder
69cdc30c6d wgengine/wgcfg: remove Config.ListenPort
We don't use the port that wireguard-go passes to us (via magicsock.connBind.Open).
We ignore it entirely and use the port we selected.

When we tell wireguard-go that we're changing the listen_port,
it calls connBind.Close and then connBind.Open.
And in the meantime, it stops calling the receive functions,
which means that we stop receiving and processing UDP and DERP packets.
And that is Very Bad.

That was never a problem prior to b3ceca1dd7,
because we passed the SkipBindUpdate flag to our wireguard-go fork,
which told wireguard-go not to re-bind on listen_port changes.
That commit eliminated the SkipBindUpdate flag.

We could write a bunch of code to work around the gap.
We could add background readers that process UDP and DERP packets when wireguard-go isn't.
But it's simpler to never create the conditions in which wireguard-go rebinds.

The other scenario in which wireguard-go re-binds is device.Down.
Conveniently, we never call device.Down. We go from device.Up to device.Close,
and the latter only when we're shutting down a magicsock.Conn completely.

Rubber-ducked-by: Avery Pennarun <apenwarr@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-04-03 10:32:51 -07:00
Josh Bleecher Snyder
b3ceca1dd7 wgengine/...: split into multiple receive functions
Upstream wireguard-go has changed its receive model.
NewDevice now accepts a conn.Bind interface.

The conn.Bind is stateless; magicsock.Conns are stateful.
To work around this, we add a connBind type that supports
cheap teardown and bring-up, backed by a Conn.

The new conn.Bind allows us to specify a set of receive functions,
rather than having to shoehorn everything into ReceiveIPv4 and ReceiveIPv6.
This lets us plumbing DERP messages directly into wireguard-go,
instead of having to mux them via ReceiveIPv4.

One consequence of the new conn.Bind layer is that
closing the wireguard-go device is now indistinguishable
from the routine bring-up and tear-down normally experienced
by a conn.Bind. We thus have to explicitly close the magicsock.Conn
when the close the wireguard-go device.

One downside of this change is that we are reliant on wireguard-go
to call receiveDERP to process DERP messages. This is fine for now,
but is perhaps something we should fix in the future.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-04-02 12:18:54 -07:00
Josh Bleecher Snyder
34d4943357 all: gofmt -s
The code is not obviously better or worse, but this makes the little warning
triangle in my editor go away, and the distraction removal is worth it.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-04-01 11:06:14 -07:00
Josh Bleecher Snyder
1df162b05b wgengine/magicsock: adapt CreateEndpoint signature to match wireguard-go
Part of a temporary change to make merging wireguard-go easier.
See https://github.com/tailscale/wireguard-go/pull/45.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-04-01 09:55:45 -07:00
Josh Bleecher Snyder
36a85e1760 wgengine/magicsock: don't call t.Fatal in magicStack.IP
It can end up executing an a new goroutine,
at which point instead of immediately stopping test execution, it hangs.
Since this is unexpected anyway, panic instead.
As a bonus, it makes call sites nicer and removes a kludge comment.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-03-30 11:48:13 -07:00
David Anderson
016de16b2e net/tstun: rename TUN to Wrapper.
The tstun packagen contains both constructors for generic tun
Devices, and a wrapper that provides additional functionality.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-03-26 23:15:22 -07:00
David Anderson
588b70f468 net/tstun: merge in wgengine/tstun.
Signed-off-by: David Anderson <danderson@tailscale.com>
2021-03-26 22:31:54 -07:00
Brad Fitzpatrick
81143b6d9a ipn/ipnlocal: start of peerapi between nodes
Also some necessary refactoring of the ipn/ipnstate too.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-25 16:00:35 -07:00
Josh Bleecher Snyder
28af46fb3b wgengine: pass logger as a separate arg to device.NewDevice
Adapt to minor API changes in wireguard-go.
And factor out device.DeviceOptions variables.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-03-24 10:39:58 -07:00
Josh Bleecher Snyder
4b77eca2de wgengine/magicsock: check returned error in addTestEndpoint
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-03-24 09:46:36 -07:00
Brad Fitzpatrick
c99f260e40 wgengine/magicsock: prefer IPv6 transport if roughly equivalent latency
Fixes #1566

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-23 17:34:01 -07:00
Brad Fitzpatrick
9643d8b34d wgengine/magicsock: add an addrLatency type to combine an IPPort+time.Duration
Updates #1566 (but no behavior changes as of this change)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-23 10:09:10 -07:00
Brad Fitzpatrick
0994a9f7c4 wgengine{,/magicsock}: fix, improve "tailscale ping" to default routes and subnets
e.g.

$ tailscale ping 1.1.1.1
exit node found but not enabled

$ tailscale ping 10.2.200.2
node "tsbfvlan2" found, but not using its 10.2.200.0/24 route

$ sudo tailscale  up --accept-routes
$ tailscale ping 10.2.200.2
pong from tsbfvlan2 (100.124.196.94) via 10.2.200.34:41641 in 1ms

$ tailscale ping mon.ts.tailscale.com
pong from monitoring (100.88.178.64) via DERP(sfo) in 83ms
pong from monitoring (100.88.178.64) via DERP(sfo) in 21ms
pong from monitoring (100.88.178.64) via [2604:a880:4:d1::37:d001]:41641 in 22ms

This necessarily moves code up from magicsock to wgengine, so we can
look at the actual wireguard config.

Fixes #1564

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-22 21:29:44 -07:00
Brad Fitzpatrick
7e0d12e7cc wgengine/magicsock: don't update control if only endpoint order changes
Updates #1559

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-22 10:37:04 -07:00
Brad Fitzpatrick
32562a82a9 wgengine/magicsock: annotate a few more disco logs as verbose
Fixes #1540

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-19 13:24:29 -07:00
Brad Fitzpatrick
c19ed37b0f wgengine/magicsock: mark some legacy debug log output as verbose
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-18 08:17:59 -07:00
Brad Fitzpatrick
ba8c6d0775 health, controlclient, ipn, magicsock: tell health package state of things
Not yet checking anything. Just plumbing states into the health package.

Updates #1505

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-15 15:20:55 -07:00
Brad Fitzpatrick
44ab0acbdb net/portmapper, wgengine/monitor: cache gateway IP info until link changes
Cuts down allocs & CPU in steady state (on regular STUN probes) when network
is unchanging.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-15 14:27:39 -07:00
Brad Fitzpatrick
c81814e4f8 derp{,/derphttp},magicsock: tell DERP server when ping acks can be expected
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-12 09:55:02 -08:00
Brad Fitzpatrick
c576fea60e wgengine/magicsock: delete unused WhoIs method that was moved elsewhere
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-11 11:44:01 -08:00
Brad Fitzpatrick
ef7bac2895 tailcfg, net/portmapper, wgengine/magicsock: add NetInfo.HavePortMap
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-09 15:17:24 -08:00
Brad Fitzpatrick
79d8288f0a wgengine/magicsock, derp, derp/derphttp: respond to DERP server->client pings
No server support yet, but we want Tailscale 1.6 clients to be able to respond
to them when the server can do it.

Updates #1310

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-09 13:56:13 -08:00
Brad Fitzpatrick
387e83c8fe wgengine/magicsock: fix Conn.Rebind race that let ErrClosed errors be read
There was a logical race where Conn.Rebind could acquire the
RebindingUDPConn mutex, close the connection, fail to rebind, release
the mutex, and then because the mutex was no longer held, ReceiveIPv4
wouldn't retry reads that failed with net.ErrClosed, letting that
error back to wireguard-go, which would then stop running that receive
IP goroutine.

Instead, keep the RebindingUDPConn mutex held for the entirety of the
replacement in all cases.

Updates tailscale/corp#1289

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-08 21:08:35 -08:00
Brad Fitzpatrick
c445e3d327 wgengine/magicsock: fix typo in comment 2021-03-08 15:27:11 -08:00
Brad Fitzpatrick
a6d098c750 wgengine/magicsock: log when DERP connection succeeds
Updates #1310
2021-03-04 09:30:00 -08:00
Brad Fitzpatrick
829eb8363a net/interfaces: sort returned addresses from LocalAddresses
Also change the type to netaddr.IP while here, because it made sorting
easier.

Updates tailscale/corp#1397

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-04 07:04:39 -08:00
Brad Fitzpatrick
c3e5903b91 wgengine/magicsock: remove leftover portmapper debug logging
It's already logged at the right time in logEndpointChange.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-03-02 12:42:45 -08:00
Brad Fitzpatrick
ea3715e3ce wgengine/magicsock: remove TODO about endpoints-over-DERP
It was done in Tailscale 1.4 with CallMeMaybe disco messages
containing endpoints.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-02-24 21:34:31 -08:00
David Anderson
2404c0ffad ipn/ipnlocal: only filter out default routes when computing the local wg config.
UIs need to see the full unedited netmap in order to know what exit nodes they
can offer to the user.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-02-24 20:41:56 -08:00
Brad Fitzpatrick
e9e4f1063d wgengine/magicsock: fix discoEndpoint caching bug when a node key changes
Fixes #1391

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-02-23 14:39:15 -08:00
Brad Fitzpatrick
c64bd587ae net/portmapper: add NAT-PMP client, move port mapping service probing
* move probing out of netcheck into new net/portmapper package
* use PCP ANNOUNCE op codes for PCP discovery, rather than causing
  short-lived (sub-second) side effects with a 1-second-expiring map +
  delete.
* track when we heard things from the router so we can be less wasteful
  in querying the router's port mapping services in the future
* use portmapper from magicsock to map a public port

Fixes #1298
Fixes #1080
Fixes #1001
Updates #864

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-02-23 09:07:38 -08:00
Josh Bleecher Snyder
c7e5ab8094 wgengine/magicsock: retry and re-send packets in TestTwoDevicePing
When a handshake race occurs, a queued data packet can get lost.
TestTwoDevicePing expected that the very first data packet would arrive.
This caused occasional flakes.

Change TestTwoDevicePing to repeatedly re-send packets
and succeed when one of them makes it through.

This is acceptable (vs making WireGuard not drop the packets)
because this only affects communication with extremely old clients.
And those extremely old clients will eventually connect,
because the kernel will retry sends on timeout.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-02-12 14:18:58 -08:00
Josh Bleecher Snyder
1632f9fd6b wgengine/magicsock: reduce log spam during tests
Only do the type assertion to *net.UDPAddr when addr is non-nil.
This prevents a bunch of log spam during tests.
2021-02-12 10:49:02 -08:00
Josh Bleecher Snyder
88586ec4a4 wgengine/magicsock: remove an alloc from ReceiveIPvN
We modified the standard net package to not allocate a *net.UDPAddr
during a call to (*net.UDPConn).ReadFromUDP if the caller's use
of the *net.UDPAddr does not cause it to escape.
That is https://golang.org/cl/291390.

This is the companion change to magicsock.
There are two changes required.
First, call ReadFromUDP instead of ReadFrom, if possible.
ReadFrom returns a net.Addr, which is an interface, which always allocates.
Second, reduce the lifetime of the returned *net.UDPAddr.
We do this by immediately converting it into a netaddr.IPPort.

We left the existing RebindingUDPConn.ReadFrom method in place,
as it is required to satisfy the net.PacketConn interface.

With the upstream change and both of these fixes in place,
we have removed one large allocation per packet received.

name           old time/op    new time/op    delta
ReceiveFrom-8    16.7µs ± 5%    16.4µs ± 8%     ~     (p=0.310 n=5+5)

name           old alloc/op   new alloc/op   delta
ReceiveFrom-8      112B ± 0%       64B ± 0%  -42.86%  (p=0.008 n=5+5)

name           old allocs/op  new allocs/op  delta
ReceiveFrom-8      3.00 ± 0%      2.00 ± 0%  -33.33%  (p=0.008 n=5+5)

Co-authored-by: Sonia Appasamy <sonia@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-02-12 09:52:43 -08:00
Josh Bleecher Snyder
0c673c1344 wgengine/magicsock: unify on netaddr types in addrSet
addrSet maintained duplicate lists of netaddr.IPPorts and net.UDPAddrs.
Unify to use the netaddr type only.

This makes (*Conn).ReceiveIPvN a bit uglier,
but that'll be cleaned up in a subsequent commit.

This is preparatory work to remove an allocation from ReceiveIPv4.

Co-authored-by: Sonia Appasamy <sonia@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-02-12 09:52:43 -08:00
Josh Bleecher Snyder
4cd9218351 wgengine/magicsock: prevent logging while running benchmarks
Co-authored-by: Sonia Appasamy <sonia@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-02-12 09:52:43 -08:00
Josh Bleecher Snyder
635e4c7435 wgengine/magicsock: increase legacy ping timeout again
I based my estimation of the required timeout based on locally
observed behavior. But CI machines are worse than my local machine.
16s was enough to reduce flakiness but not eliminate it. Bump it up again.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-02-10 13:50:18 -08:00
Brad Fitzpatrick
7e201806b1 wgengine/magicsock: reconnect to DERP home after network comes back up
Updates #1310
2021-02-10 10:29:03 -08:00
Brad Fitzpatrick
9b4e50cec0 wgengine/magicsock: fix typo in comment 2021-02-09 09:37:24 -08:00
Brad Fitzpatrick
6b365b0239 wgengine/magicsock: fix DERP reader hang regression during concurrent reads
Fixes #1282

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-02-08 14:30:15 -08:00
Josh Bleecher Snyder
e1f773ebba wgengine/magicsock: allow more time for pings to transit
We removed the "fast retry" code from our wireguard-go fork.
As a result, pings can take longer to transit when retries are required. 
Allow that.

Fixes #1277

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-02-08 13:54:37 -08:00
Brad Fitzpatrick
6d2b8df06d wgengine/magicsock: add disabled failing (deadlocking) test for #1282
The fix can make this test run unconditionally.

This moves code from 5c619882bc for
testability but doesn't fix it yet. The #1282 problem remains (when I
wrote its wake-up mechanism, I forgot there were N DERP readers
funneling into 1 UDP reader, and the code just isn't correct at all
for that case).

Also factor out some test helper code from BenchmarkReceiveFrom.

The refactoring in magicsock.go for testability should have no
behavior change.
2021-02-06 21:34:16 -08:00
Brad Fitzpatrick
1e7a35b225 types/netmap: split controlclient.NetworkMap off into its own leaf package
Updates #1278

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-02-05 16:18:52 -08:00
Brad Fitzpatrick
6064b6ff47 wgengine/wgcfg/nmcfg: split control/controlclient/netmap.go into own package
It couldn't move to ipnlocal due to test dependency cycles.

Updates #1278

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-02-05 14:21:30 -08:00
David Anderson
ace57d7627 wgengine/magicsock: set a dummy private key in benchmark.
Magicsock started dropping all traffic internally when Tailscale is
shut down, to avoid spurious wireguard logspam. This made the benchmark
not receive anything. Setting a dummy private key is sufficient to get
magicsock to pass traffic for benchmarking purposes.

Fixes #1270.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-02-05 13:36:05 -08:00
Brad Fitzpatrick
f7eed25bb9 wgengine/magicsock: filter disco packets and packets when stopped from wireguard
Fixes #1167
Fixes tailscale/corp#219

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-02-04 09:38:02 -08:00
Josh Bleecher Snyder
e8cd7bb66f tstest: simplify goroutine leak tests
Use tb.Cleanup to simplify both the API and the implementation.

One behavior change: When the number of goroutines shrinks, don't log.
I've never found these logs to be useful, and they frequently add noise.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-02-03 13:06:40 -08:00
Josh Bleecher Snyder
dd10babaed wgenginer/magicsock: remove Addrs methods
They are now unused.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-02-01 14:05:05 -08:00
Josh Bleecher Snyder
fe7c3e9c17 all: move wgcfg from wireguard-go
This is mostly code movement from the wireguard-go repo.

Most of the new wgcfg package corresponds to the wireguard-go wgcfg package.

wgengine/wgcfg/device{_test}.go was device/config{_test}.go.
There were substantive but simple changes to device_test.go to remove
internal package device references.

The API of device.Config (now wgcfg.DeviceConfig) grew an error return;
we previously logged the error and threw it away.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-29 12:52:56 -08:00
Josh Bleecher Snyder
d5baeeed5c wgengine: use Tailscale-style peer identifiers in logs
Rewrite log lines on the fly, based on the set of known peers.

This enables us to use upstream wireguard-go logging,
but maintain the Tailscale-style peer public key identifiers
that the rest of our systems (and people) expect.

Fixes #1183

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-21 19:13:32 -08:00
Brad Fitzpatrick
9541886856 wgengine/magicsock: disable regular STUNs for all platforms by default
Reduces background CPU & network.

Updates #1034

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-01-21 14:56:07 -08:00
Brad Fitzpatrick
c55d26967b wgengine/magicsock: log more details of endpoints learned over disco
Also, don't try to use IPv6 LinkLocalUnicast addresses for now. Like endpoints
exchanged with control, we share them but don't yet use them.

Updates #1172
2021-01-21 08:06:14 -08:00
Brad Fitzpatrick
359055d3fa wgengine/magicsock: fix logging regression
c8c493f3d9 made it always say
`created=false` which scared me when I saw it, as that would've implied
things were broken much worse. Fortunately the logging was just wrong.
2021-01-20 20:48:02 -08:00
Brad Fitzpatrick
edf64e0901 wgengine/magicsock: send, use endpoints in CallMeMaybe messages
Fixes #1172

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-01-20 14:59:41 -08:00
Brad Fitzpatrick
b5b4992eff disco: support parsing/encoding endpoints in call-me-maybe frames
Updates #1172

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-01-20 12:16:33 -08:00
Josh Bleecher Snyder
d3dd7c6270 wgengine/magicsock: make legacy DstToString match Addrs
DstToString is used in two places in wireguard-go: Logging and uapi.

We are switching to use uapi for wireguard-go config.
To preserve existing behavior, we need the full set of addrs.

And for logging, having the full set of addrs seems useful.

(The Addrs method itself is slated for removal. When that happens,
the implementation will move to DstToString.)


Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-20 10:31:51 -08:00
Brad Fitzpatrick
187e22a756 wgengine/magicsock: don't run the DERP cleanup so often
To save CPU and wakeups, don't run the DERP cleanup timer regularly
unless there is a non-home DERP connection open.

Also eliminates the goroutine, moving to a time.AfterFunc.

Updates #1034

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-01-19 18:14:25 -08:00
Josh Bleecher Snyder
5fe5402fcd Revert "wgengine/magicsock: shortcircuit discoEndpoint.heartbeat when its connection is closed"
This reverts commit 08baa17d9a.
It caused deadlocks due to lock ordering violations.
It was not the right fix, and thus should simply be reverted
while we look for the right fix (if we haven't already found it
in the interim; we've fixed other logging-after-test issues).

Fixes #1161
2021-01-19 11:44:32 -08:00
Josh Bleecher Snyder
e4c075cd95 wgengine/magicsock: prevent log-after-test in TestTwoDevicePing 2021-01-19 11:04:17 -08:00
Brad Fitzpatrick
edce91a8a6 wgengine/magicsock: fix a naked return bug/crash where we returned (nil, true)
The 'ok' from 'ipp, ok :=' above was the result parameter ok. Whoops.
2021-01-19 10:57:40 -08:00
Brad Fitzpatrick
51bd1feae4 wgengine/magicsock: add single element IPPort->endpoint cache in receive path
name           old time/op  new time/op  delta
ReceiveFrom-4  21.8µs ± 2%  20.9µs ± 2%  -4.27%  (p=0.000 n=10+10)

Updates #414

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-01-18 21:40:58 -08:00
Brad Fitzpatrick
5c619882bc wgengine/magicsock: simplify ReceiveIPv4+DERP path
name           old time/op  new time/op  delta
ReceiveFrom-4  35.8µs ± 3%  21.9µs ± 5%  -38.92%  (p=0.008 n=5+5)

Fixes #1145
Updates #414

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-01-18 15:23:17 -08:00
Brad Fitzpatrick
3fa86a8b23 wgengine/magicsock: use relatively new netaddr.IPPort.IsZero method 2021-01-15 19:21:10 -08:00
Brad Fitzpatrick
4811236189 wgengine/magicsock: speed up BenchmarkReceiveFrom, store context.Done chan
context.cancelCtx.Done involves a mutex and isn't as cheap as I
previously assumed. Convert the donec method into a struct field and
store the channel value once. Our one magicsock.Conn gets one pointer
larger, but it cuts ~1% of the CPU time of the ReceiveFrom benchmark
and removes a bubble from the --svg output :)
2021-01-15 19:19:27 -08:00
Josh Bleecher Snyder
ed2169ae99 wgengine/magicsock: prevent logging after TestActiveDiscovery completes 2021-01-15 18:19:20 -08:00
Josh Bleecher Snyder
63af950d8c wgengine/magicsock: adapt to wireguard-go without UpdateDst
22507adf54 stopped relying on
our fork of wireguard-go's UpdateDst callback.
As a result, we can unwind that code,
and the extra return value of ReceiveIPv{4,6}.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-15 17:13:58 -08:00
Denton Gentry
23c2dc2165
magicksock: remove TestConnClosing. (#1140)
Test is flakey, remove it and figure out what to do differently later.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
2021-01-15 16:55:30 -08:00
David Anderson
e23b4191c4 wgengine/magicsock: disable legacy networking everywhere except TwoDevicePing.
TwoDevicePing is explicitly testing the behavior of the legacy codepath, everything
else is happy to assume that code no longer exists.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-01-15 16:02:31 -08:00
David Anderson
0733c5d2e0 wgengine/magicsock: disable legacy behavior in a few more tests.
Signed-off-by: David Anderson <danderson@tailscale.com>
2021-01-15 15:57:41 -08:00
David Anderson
57d95dd005 wgengine/magicsock: default legacy networking to off for some tests.
Signed-off-by: David Anderson <danderson@tailscale.com>
2021-01-15 15:54:45 -08:00
David Anderson
a2463e8948 wgengine/magicsock: add an option to disable legacy peer handling.
Used in tests to ensure we're not relying on behavior we're going
to remove eventually.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-01-15 15:01:33 -08:00
David Anderson
d456bfdc6d wgengine/magicsock: fix BenchmarkReceiveFrom.
Previously, this benchmark relied on behavior of the legacy
receive codepath, which I changed in 22507adf. With this
change, the benchmark instead relies on the new active discovery
path.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-01-15 15:01:33 -08:00
Josh Bleecher Snyder
2d837f79dc wgengine/magicsock: close test loggers once we're done with them
This is a big hammer approach to helping with #1132.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-15 14:44:56 -08:00
Josh Bleecher Snyder
08baa17d9a wgengine/magicsock: shortcircuit discoEndpoint.heartbeat when its connection is closed
This prevents us from continuing to do unnecessary work
(including logging) after the connection has closed.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-15 14:44:56 -08:00
Josh Bleecher Snyder
7c76435bf7 wgengine/magicsock: simplify
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-15 14:44:56 -08:00
Josh Bleecher Snyder
d2529affa2 wgengine/magicsock: quiet wireguard-go logging in tests
We already do this in newUserspaceEngineAdvanced.
Apply it to newMagicStack as well.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-15 14:44:56 -08:00
Josh Bleecher Snyder
654b5f1570 all: convert from []wgcfg.Endpoint to string
This eliminates a dependency on wgcfg.Endpoint,
as part of the effort to eliminate our wireguard-go fork.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-14 13:54:07 -08:00
David Anderson
9abcb18061 wgengine/magicsock: import more of wireguard-go, update docstrings.
Signed-off-by: David Anderson <danderson@tailscale.com>
2021-01-14 12:56:48 -08:00
David Anderson
22507adf54 wgengine/magicsock: stop depending on UpdateDst in legacy codepaths.
This makes connectivity between ancient and new tailscale nodes slightly
worse in some cases, but only in cases where the ancient version would
likely have failed to get connectivity anyway.

Signed-off-by: David Anderson <danderson@tailscale.com>
2021-01-14 12:56:48 -08:00
Denton Gentry
8349e10907 magicsock: add description of testClosingContext
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
2021-01-12 04:29:28 -08:00
Denton Gentry
2e9728023b magicsock: test error case in sendDiscoMessage
In sendDiscoMessage there is a check of whether the connection is
closed, which is not being reliably exercised by other tests.
This shows up in code coverage reports, the lines of code in
sendDiscoMessage are alternately added and subtracted from
code coverage.

Add a test to specifically exercise and verify this code path.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
2021-01-12 04:29:28 -08:00
Denton Gentry
0aa55bffce magicsock: test error case in derpWriteChanOfAddr
In derpWriteChanOfAddr when we call derphttp.NewRegionClient(),
there is a check of whether the connection is already errored and
if so it returns before grabbing the lock. The lock might already
be held and would be a deadlock.

This corner case is not being reliably exercised by other tests.
This shows up in code coverage reports, the lines of code in
derpWriteChanOfAddr are alternately added and subtracted from
code coverage.

Add a test to specifically exercise this code path, and verify that
it doesn't deadlock.

This is the best tradeoff I could come up with:
+ the moment code calls Err() to check if there is an error, we
  grab the lock to make sure it would deadlock if it tries to grab
  the lock itself.
+ if a new call to Err() is added in this code path, only the
  first one will be covered and the rest will not be tested.
+ this test doesn't verify whether code is checking for Err() in
  the right place, which ideally I guess it would.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
2021-01-12 04:29:28 -08:00
Brad Fitzpatrick
85e54af0d7 wgengine: on TCP connect fail/timeout, log some clues about why it failed
So users can see why things aren't working.

A start. More diagnostics coming.

Updates #1094
2021-01-11 22:09:09 -08:00
Brad Fitzpatrick
f85769b1ed wgengine/magicsock: drop netaddr.IPPort cache
netaddr.IP no longer allocates, so don't need a cache or all its associated
code/complexity.

This totally removes groupcache/lru from the deps.

Also go mod tidy.
2021-01-11 13:23:04 -08:00
Brad Fitzpatrick
5aa5db89d6 cmd/tailscaled, wgengine/netstack: add start of gvisor userspace netstack work
Not usefully functional yet (mostly a proof of concept), but getting
it submitted for some work @namansood is going to do atop this.

Updates #707
Updates #634
Updates #48
Updates #835
2021-01-11 09:31:14 -08:00
Brad Fitzpatrick
5efb0a8bca cmd/tailscale: change formatting of "tailscale status"
* show DNS name over hostname, removing domain's common MagicDNS suffix.
  only show hostname if there's no DNS name.
  but still show shared devices' MagicDNS FQDN.

* remove nerdy low-level details by default: endpoints, DERP relay,
  public key.  They're available in JSON mode still for those who need
  them.

* only show endpoint or DERP relay when it's active with the goal of
  making debugging easier. (so it's easier for users to understand
  what's happening) The asterisks are gone.

* remove Tx/Rx numbers by default for idle peers; only show them when
  there's traffic.

* include peers' owner login names

* add CLI option to not show peers (matching --self=true, --peers= also
  defaults to true)

* sort by DNS/host name, not public key

* reorder columns
2021-01-10 12:11:22 -08:00
Brad Fitzpatrick
b5b9866ba2 wgengine/magicsock: copy self DNS name to PeerStatus, re-fill OS
The OS used to be sent back from the server but that has since
been removed as being redundant.
2021-01-08 20:55:57 -08:00
David Anderson
86fe22a1b1 Update netaddr, and adjust wgengine/magicsock due to API change.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-30 17:36:03 -08:00
Josh Bleecher Snyder
56a7652dc9 wgkey: new package
This is a replacement for the key-related parts
of the wireguard-go wgcfg package.

This is almost a straight copy/paste from the wgcfg package.
I have slightly changed some of the exported functions and types
to avoid stutter, added and tweaked some comments,
and removed some now-unused code.

To avoid having wireguard-go depend on this new package,
wgcfg will keep its key types.

We translate into and out of those types at the last minute.
These few remaining uses will be eliminated alongside
the rest of the wgcfg package.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-12-30 17:33:02 -08:00
Josh Bleecher Snyder
2fe770ed72 all: replace wgcfg.IP and wgcfg.CIDR with netaddr types
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-12-28 13:00:42 -08:00
Brad Fitzpatrick
053a1d1340 all: annotate log verbosity levels on most egregiously spammy log prints
Fixes #924
Fixes #282

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-12-21 12:59:33 -08:00
David Anderson
294ceb513c ipn, wgengine/magicsock: fix tailscale status display.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-19 13:50:44 -08:00
David Anderson
c8c493f3d9 wgengine/magicsock: make ReceiveIPv4 a little easier to follow.
The previous code used a lot of whole-function variables and shared
behavior that only triggered based on prior action from a single codepath.
Instead of that, move the small amounts of "shared" code into each switch
case.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-18 01:15:53 -08:00
David Anderson
0ad109f63d wgengine/magicsock: move legacy endpoint creation into legacy.go.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-18 01:15:53 -08:00
David Anderson
f873da5b16 wgengine/magicsock: move more legacy endpoint handling.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-18 01:15:53 -08:00
David Anderson
58fcd103c4 wgengine/magicsock: move legacy sending code to legacy.go.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-18 01:15:53 -08:00
David Anderson
65ae66260f wgengine/magicsock: unexport AddrSet.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-18 01:15:53 -08:00
David Anderson
c9b9afd761 wgengine/magicsock: move most legacy nat traversal bits to another file.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-18 01:15:53 -08:00
David Anderson
554a20becb wgengine/magicsock: only log about lazy config when actually doing lazy config.
Before, tailscaled would log every 10 seconds when the periodic noteRecvActivity
call happens. This is noisy, but worse it's misleading, because the message
suggests that the disco code is starting a lazy config run for a missing peer,
whereas in fact it's just an internal piece of keepalive logic.

With this change, we still log when going from 0->1 tunnel for the peer, but
not every 10s thereafter.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-17 12:11:36 -08:00
Brad Fitzpatrick
fa412c8760 wgengine/filter, wgengine/magicsock: use new IP.BitLen to simplify some code 2020-12-15 12:12:56 -08:00
David Anderson
9cee0bfa8c wgengine/magicsock: sprinkle more docstrings.
Magicsock is too damn big, but this might help me page it back
in faster next time.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-14 23:59:17 -08:00
Brad Fitzpatrick
7b92f8e718 wgengine/magicsock: add start of magicsock benchmarks (Conn.ReceiveIPv4 for now)
And only single-threaded for now. Will get fancier later.

Updates #414
2020-12-02 20:26:54 -08:00
Brad Fitzpatrick
713cbe84c1 wgengine/magicsock: use net.JoinHostPort when host might have colons (udp6)
Only affected tests. (where it just generated log spam)
2020-12-02 20:19:28 -08:00
Brad Fitzpatrick
450cfedeba wgengine/magicsock: quiet an IPv6 warning in tests
In tests, we force binding to localhost to avoid OS firewall warning
dialogs.

But for IPv6, we were trying (and failing) to bind to 127.0.0.1.

You'd think we'd just say "localhost", but that's apparently ill
defined. See
https://tools.ietf.org/html/draft-ietf-dnsop-let-localhost-be-localhost
and golang/go#22826. (It's bitten me in the past, but I can't
remember specific bugs.)

So use "::1" explicitly for "udp6", which makes the test quieter.
2020-11-10 09:14:29 -08:00
David Anderson
7a54910990 wgengine/filter: remove helper vars, mark NewAllowAll test-only.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-11-09 22:02:37 -08:00
David Anderson
b3634f020d wgengine/filter: use netaddr types in public API.
We still use the packet.* alloc-free types in the data path, but
the compilation from netaddr to packet happens within the filter
package.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-11-09 21:39:25 -08:00
Brad Fitzpatrick
fd2a30cd32 wgengine/magicsock: make test pass on Windows and without firewall dialog box
Updates #50
2020-10-28 09:02:08 -07:00
Brad Fitzpatrick
ac866054c7 wgengine/magicsock: add a backoff on DERP reconnects
Fixes #808
2020-10-19 15:15:40 -07:00
Brad Fitzpatrick
105a820622 wgengine/magicsock: skip an endpoint update at start-up
At startup the client doesn't yet have the DERP map so can't do STUN
queries against DERP servers, so it only knows it local interface
addresses, not its STUN-mapped addresses.

We were reporting the interface-local addresses to control, getting
the DERP map, and then immediately reporting the full set of
updates. That was an extra HTTP request to control, but worse: it was
an extra broadcast from control out to all the peers in the network.

Now, skip the initial update if there are no stun results and we don't
have a DERP map.

More work remains optimizing start-up requests/map updates, but this
is a start.

Updates tailscale/corp#557
2020-10-14 11:01:19 -07:00
Brad Fitzpatrick
2076a50862 wgengine/magicsock: finish a comment sentence that ended prematurely 2020-10-13 12:10:51 -07:00
Brad Fitzpatrick
3e4c46259d wgengine/magicsock: don't do netchecks either when network is down
A continuation of 6ee219a25d

Updates #640
2020-10-06 20:24:10 -07:00
Brad Fitzpatrick
6ee219a25d ipn, wgengine, magicsock, tsdns: be quieter and less aggressive when offline
If no interfaces are up, calm down and stop spamming so much. It was
noticed as especially bad on Windows, but probably was bad
everywhere. I just have the best network conditions testing on a
Windows VM.

Updates #604
2020-10-06 15:26:53 -07:00
Brad Fitzpatrick
c86761cfd1 Remove tuntap references. We only use TUN. 2020-09-25 13:13:13 -07:00
Christina Wen
48fbe93e72
wgengine/magicsock: clarify pre-disco 'tailscale ping' error message
This change clarifies the error message when a user pings a peer that is using an outdated version of Tailscale.
2020-09-16 11:54:00 -04:00
Josh Bleecher Snyder
a5d701095b wgengine/magicsock: increase test timeout to reduce flakiness
Updates #654. See that issue for a discussion of why
this timeout reduces flakiness, and what next steps are.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-09-14 14:29:28 -07:00
Josh Bleecher Snyder
0c0239242c wgengine/magicsock: make discoPingPurpose a stringer
It was useful for debugging once, it'll probably be useful again.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-09-14 14:29:28 -07:00
Josh Bleecher Snyder
6e38d29485 wgengine/magicsock: improve test logging output
This fixes line numbers and reduces timestamp
precision to overwhelming the output.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-09-14 14:29:28 -07:00
Josh Bleecher Snyder
57e642648f wgengine/magicsock: fix typo in comment 2020-09-02 11:34:20 -07:00
Brad Fitzpatrick
756d6a72bd wgengine: lazily create peer wireguard configs more explicitly
Rather than consider bigs jumps in last-received-from activity as a
signal to possibly reconfigure the set of wireguard peers to have
configured, instead just track the set of peers that are currently
excluded from the configuration. Easier to reason about.

Also adds a bit more logging.

This might fix an error we saw on a machine running a recent unstable
build:

2020-08-26 17:54:11.528033751 +0000 UTC: 8.6M/92.6M magicsock: [unexpected] lazy endpoint not created for [UcppE], d:42a770f678357249
2020-08-26 17:54:13.691305296 +0000 UTC: 8.7M/92.6M magicsock: DERP packet received from idle peer [UcppE]; created=false
2020-08-26 17:54:13.691383687 +0000 UTC: 8.7M/92.6M magicsock: DERP packet from unknown key: [UcppE]

If it does happen again, though, we'll have more logs.
2020-08-26 12:26:06 -07:00
halulu
f27a57911b
cmd/tailscale: add derp and endpoints status (#703)
cmd/tailscale: add local node's information to status output (by default)

RELNOTE=yes

Updates #477

Signed-off-by: Halulu <lzjluzijie@gmail.com>
2020-08-25 16:26:10 -07:00
David Crawshaw
dd2c61a519 magicsock: call RequestStatus when DERP connects
Second attempt.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
2020-08-25 16:35:28 -04:00
David Crawshaw
a67b174da1 Revert "magicsock: call RequestStatus when DERP connects"
Seems to break linux CI builder. Cannot reproduce locally,
so attempting a rollback.

This reverts commit cd7bc02ab1.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
2020-08-25 15:15:37 -04:00
David Crawshaw
cd7bc02ab1 magicsock: call RequestStatus when DERP connects
Without this, a freshly started ipn client will be stuck in the
"Starting" state until something triggers a call to RequestStatus.
Usually a UI does this, but until then we can sit in this state
until poked by an external event, as is evidenced by our e2e tests
locking up when DERP is attached.

(This only recently became a problem when we enabled lazy handshaking
everywhere, otherwise the wireugard tunnel creation would also
trigger a RequestStatus.)

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
2020-08-25 10:38:02 -04:00
Brad Fitzpatrick
f6dc47efe4 tailcfg, controlclient, magicsock: add control feature flag to enable DRPO
Updates #150
2020-08-17 13:01:39 -07:00
Brad Fitzpatrick
85c3d17b3c wgengine/magicsock: use disco ping src as a candidate endpoint
Consider:

   Hard NAT (A) <---> Hard NAT w/ mapped port (B)

If A sends a packet to B's mapped port, A can disco ping B directly,
with low latency, without DERP.

But B couldn't establish a path back to A and needed to use DERP,
despite already logging about A's endpoint and adding a mapping to it
for other purposes (the wireguard conn.Endpoint lookup also needed
it).

This adds the tracking to discoEndpoint too so it'll be used for
finding a path back.

Fixes tailscale/corp#556

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-08-12 21:33:43 -07:00
Brad Fitzpatrick
0512fd89a1 wgengine/magicsock: simplify handlePingLocked
It's no longer true that 'de may be nil'
2020-08-12 19:25:38 -07:00
Brad Fitzpatrick
84dc891843 cmd/tailscale/cli: add ping subcommand
For example:

$ tailscale ping -h
USAGE
  ping <hostname-or-IP>

FLAGS
  -c 10                   max number of pings to send
  -stop-once-direct true  stop once a direct path is established
  -verbose false          verbose output

$ tailscale ping mon.ts.tailscale.com
pong from monitoring (100.88.178.64) via DERP(sfo) in 65ms
pong from monitoring (100.88.178.64) via DERP(sfo) in 252ms
pong from monitoring (100.88.178.64) via [2604:a880:2:d1::36:d001]:41641 in 33ms

Fixes #661

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-08-10 12:50:56 -07:00
Brad Fitzpatrick
9a346fd8b4 wgengine,magicsock: fix two lazy wireguard config issues
1) we weren't waking up a discoEndpoint that once existed and
   went idle for 5 minutes and then got a disco message again.

2) userspaceEngine.noteReceiveActivity had a buggy check; fixed
   and added a test
2020-08-06 15:02:29 -07:00
Brad Fitzpatrick
41c4560592 control/controlclient: remove unused NetworkMap.UAPI method
And remove last remaining use of wgcfg.ToUAPI in a test's debug
output; replace it with JSON.
2020-08-06 10:30:18 -07:00
Brad Fitzpatrick
cff737786e wgengine/magicsock: fix lazy config deadlock, document more lock ordering
This removes the atomic bool that tried to track whether we needed to acquire
the lock on a future recursive call back into magicsock. Unfortunately that
hack doesn't work because we also had a lock ordering issue between magicsock
and userspaceEngine (see issue). This documents that too.

Fixes #644
2020-08-06 08:43:48 -07:00
Brad Fitzpatrick
2bd9ad4b40 wgengine: fix deadlock between engine and magicsock 2020-08-05 16:37:15 -07:00
Brad Fitzpatrick
7c38db0c97 wgengine/magicsock: don't deadlock on pre-disco Endpoints w/ lazy wireguard configs
Fixes tailscale/tailscale#637
2020-08-04 17:06:05 -07:00
Brad Fitzpatrick
4987a7d46c wgengine/magicsock: when hard NAT, add stun-ipv4:static-port as candidate
If a node is behind a hard NAT and is using an explicit local port
number, assume they might've mapped a port and add their public IPv4
address with the local tailscaled's port number as a candidate endpoint.
2020-08-04 09:48:34 -07:00
Brad Fitzpatrick
bfcb0aa0be wgengine/magicsock: deflake tests, Close deadlock again
Better fix than 37903a9056

Fixes tailscale/corp#533
2020-08-04 09:36:38 -07:00
Dmytro Shynkevych
28e52a0492
all: dns refactor, add Proxied and PerDomain flags from control (#615)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-31 16:27:09 -04:00
Brad Fitzpatrick
cb970539a6 wgengine/magicsock: remove TODO comment that's no longer applicable 2020-07-30 21:33:37 -07:00
Brad Fitzpatrick
915f65ddae wgengine/magicsock: stop disco activity on IPN stop
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-07-30 14:01:33 -07:00
Brad Fitzpatrick
c180abd7cf wgengine/magicsock: merge errClosed and errConnClosed 2020-07-30 13:59:30 -07:00
Brad Fitzpatrick
d55fdd4669 wgengine/magicsock: update, flesh out a TODO 2020-07-29 12:59:25 -07:00
David Anderson
f8e4c75f6b wgengine/magicsock: check slightly less aggressively for connectivity.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-28 17:04:48 +00:00
Brad Fitzpatrick
58b721f374 wgengine/magicsock: deflake some tests with an ugly hack
Starting with fe68841dc7, some e2e tests
got flaky. Rather than debug them (they're gnarly), just revert to the old
behavior as far as those tests are concerned. The tests were somehow
using magicsock without a private key and expecting it to do ... something.

My goal with fe68841dc7 was to stop log spam
and unnecessary work I saw on the iOS app when when stopping the app.

Instead, only stop doing that work on any transition from
once-had-a-private-key to no-longer-have-a-private-key. That fixes
what I wanted to fix while still making the mysterious e2e tests
happy.
2020-07-27 16:32:35 -07:00
David Anderson
41d0c81859 wgengine/magicsock: make disco subtest name more precise.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
David Anderson
9beea8b314 wgengine/magicsock: remove unnecessary use of context.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
David Anderson
b62341d308 wgengine/magicsock: add docstring.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
David Anderson
9265296b33 wgengine/magicsock: don't deadlock on shutdown if sending blocks.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
David Anderson
0249236cc0 ipn/ipnstate: record assigned Tailscale IPs.
wgengine/magicsock: use ipnstate to find assigned Tailscale IPs.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
David Anderson
c3958898f1 tstest/natlab: be a bit more lenient during test shutdown.
There is a race in natlab where we might start shutdown while natlab is still running
a goroutine or two to deliver packets. This adds a small grace period to try and receive
it before continuing shutdown.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
David Anderson
7578c815be wgengine/magicsock: give pinger a more generous packet timeout.
The first packet to transit may take several seconds to do so, because
setup rates in wgengine may result in the initial WireGuard handshake
init to get dropped. So, we have to wait at least long enough for a
retransmit to correct the fault.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
David Anderson
c3994fd77c derp: remove OnlyDisco option.
Active discovery lets us introspect the state of the network stack precisely
enough that it's unnecessary, and dropping the initial DERP packets greatly
slows down tests. Additionally, it's unrealistic since our production network
will never deliver _only_ discovery packets, it'll be all or nothing.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
David Anderson
5455c64f1d wgengine/magicsock: add a test for two facing endpoint-independent NATs.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
David Anderson
f794493b4f wgengine/magicsock: explicitly check path discovery, add a firewall test.
The test proves that active discovery can traverse two facing firewalls.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
David Anderson
f582eeabd1 wgengine/magicsock: add a test for active path discovery.
Uses natlab only, because the point of this active discovery test is going to be
that it should get through a lot of obstacles.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-27 14:09:54 -07:00
Brad Fitzpatrick
37903a9056 wgengine/magicsock: fix occasional deadlock on Conn.Close on c.derpStarted
The deadlock was:

* Conn.Close was called, which acquired c.mu
* Then this goroutine scheduled:

    if firstDerp {
        startGate = c.derpStarted
        go func() {
            dc.Connect(ctx)
            close(c.derpStarted)
        }()
    }

* The getRegion hook for that derphttp.Client then ran, which also
  tries to acquire c.mu.

This change makes that hook first see if we're already in a closing
state and then it can pretend that region doesn't exist.
2020-07-27 12:27:10 -07:00
Brad Fitzpatrick
fe68841dc7 wgengine/magicsock: log better with less spam on transition to stopped state
Required a minor test update too, which now needs a private key to get far
enough to test the thing being tested.
2020-07-27 10:19:17 -07:00
Brad Fitzpatrick
e298327ba8 wgengine/magicsock: remove overkill, slow reflect.DeepEqual of NetworkMap
No need to allocate or compare all the fields we don't care about.
2020-07-25 19:37:08 -07:00
David Anderson
3669296cef wgengine/magicsock: refactor twoDevicePing to make stack construction cleaner.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-24 15:12:15 -07:00
Brad Fitzpatrick
16a9cfe2f4 wgengine: configure wireguard peers lazily, as needed
wireguard-go uses 3 goroutines per peer (with reasonably large stacks
& buffers).

Rather than tell wireguard-go about all our peers, only tell it about
peers we're actively communicating with. That means we need hooks into
magicsock's packet receiving path and tstun's packet sending path to
lazily create a wireguard peer on demand from the network map.

This frees up lots of memory for iOS (where we have almost nothing
left for larger domains with many users).

We should ideally do this in wireguard-go itself one day, but that'd
be a pretty big change.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-07-24 12:50:15 -07:00
Brad Fitzpatrick
5066b824a6 wgengine/magicsock: don't log about disco ping timeouts if we have a working address
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-07-24 11:21:50 -07:00
Brad Fitzpatrick
c06d2a8513 wgengine/magicsock: fix typo in comment 2020-07-18 13:57:26 -07:00
Brad Fitzpatrick
bf195cd3d8 wgengine/magicsock: reduce log verbosity of discovery messages
Don't log heartbeat pings & pongs. Track the reason for pings and then
only log the ping/pong traffic if it was for initial path discovery.
2020-07-18 13:54:00 -07:00
Brad Fitzpatrick
a6559a8924 wgengine/magicsock: run test DERP in mode where only disco packets allowed
So we don't accidentally pass a NAT traversal test by having DERP pick up our slack
when we really just wanted DERP as an OOB messaging channel.
2020-07-16 12:58:35 -07:00
Brad Fitzpatrick
10ac066013 all: fix vet warnings 2020-07-16 08:39:38 -07:00
Brad Fitzpatrick
d74c9aa95b wgengine/magicsock: update comment, fix earlier commit
891898525c had a continue that meant the didCopy synchronization never ran.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-07-16 08:29:38 -07:00
Brad Fitzpatrick
c976264bd1 wgengine/magicsock: gofmt 2020-07-16 08:15:27 -07:00
Dmytro Shynkevych
f3e2b65637
wgengine/magicsock: time.Sleep -> time.After
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-16 11:04:53 -04:00
Dmytro Shynkevych
380ee76d00
wgengine/magicsock: make time.Sleep in runDerpReader respect cancellation.
Before this patch, the 250ms sleep would not be interrupted by context cancellation,
which would result in the goroutine sometimes lingering in tests (100ms grace period).

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-16 10:45:48 -04:00
Dmytro Shynkevych
891898525c
wgengine/magicsock: make receive from didCopy respect cancellation.
Very rarely, cancellation occurs between a successful send on derpRecvCh
and a call to copyBuf on the receiving side.
Without this patch, this situation results in <-copyBuf blocking indefinitely.

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-16 10:34:49 -04:00
Brad Fitzpatrick
a2267aae99 wgengine: only launch pingers for peers predating the discovery protocol
Peers advertising a discovery key know how to speak the discovery
protocol and do their own heartbeats to get through NATs and keep NATs
open. No need for the pinger except for with legacy peers.
2020-07-15 21:08:26 -07:00
David Anderson
45578b47f3 tstest/natlab: refactor PacketHandler into a larger interface.
The new interface lets implementors more precisely distinguish
local traffic from forwarded traffic, and applies different
forwarding logic within Machines for each type. This allows
Machines to be packet forwarders, which didn't quite work
with the implementation of Inject.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-15 14:38:33 -07:00
Dmytro Shynkevych
2f15894a10 wgengine/magicsock: wait for derphttp client goroutine to exit
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-07-14 14:20:35 -04:00
David Anderson
88e8456e9b wgengine/magicsock: add a connectivity test for facing firewalls.
The test demonstrates that magicsock can traverse two stateful
firewalls facing each other, that each require localhost to
initiate connections.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-11 07:04:08 +00:00
David Anderson
1f7b1a4c6c wgengine/magicsock: rearrange TwoDevicePing test for future natlab tests.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-11 06:48:08 +00:00
David Anderson
977381f9cc wgengine/magicsock: make trivial natlab test pass.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-07-11 01:53:21 +00:00
Brad Fitzpatrick
6c74065053 wgengine/magicsock, tstest/natlab: start hooking up natlab to magicsock
Also adds ephemeral port support to natlab.

Work in progress.

Pairing with @danderson.
2020-07-10 14:32:58 -07:00
Brad Fitzpatrick
bd59bba8e6 wgengine/magicsock: stop discoEndpoint timers on Close
And add some defensive early returns on c.closed.
2020-07-08 16:51:17 -07:00
Brad Fitzpatrick
de875a4d87 wgengine/magicsock: remove DisableSTUNForTesting 2020-07-08 15:50:41 -07:00
Brad Fitzpatrick
5c6d8e3053 netcheck, tailcfg, interfaces, magicsock: survey UPnP, NAT-PMP, PCP
Don't do anything with UPnP, NAT-PMP, PCP yet, but see how common they
are in the wild.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-07-06 15:25:35 -07:00
Brad Fitzpatrick
6196b7e658 wgengine/magicsock: change API to not permit disco key changes
Generate the disco key ourselves and give out the public half instead.

Fixes #525
2020-07-06 12:10:39 -07:00
Brad Fitzpatrick
5132edacf7 wgengine/magicsock: fix data race from undocumented wireguard-go requirement
Endpoints need to be Stringers apparently.

Fixes tailscale/corp#422
2020-07-03 22:27:52 -07:00
Brad Fitzpatrick
630379a1d0 cmd/tailscale: add tailscale status region name, last write, consistently star
There's a lot of confusion around what tailscale status shows, so make it better:
show region names, last write time, and put stars around DERP too if active.

Now stars are always present if activity, and always somewhere.
2020-07-03 13:44:22 -07:00
Brad Fitzpatrick
9a8700b02a wgengine/magicsock: add discoEndpoint heartbeat
Updates #483
2020-07-03 12:43:39 -07:00
Brad Fitzpatrick
9f930ef2bf wgengine/magicsock: remove the discoEndpoint.timers map
It ended up being more complicated than it was worth.
2020-07-03 11:45:41 -07:00
Brad Fitzpatrick
f5f3885b5b wgengine/magicsock: bunch of misc discovery path cleanups
* fix tailscale status for peers using discovery
* as part of that, pull out disco address selection into reusable
  and testable discoEndpoint.addrForSendLocked
* truncate ping/pong logged hex txids in half to eliminate noise
* move a bunch of random time constants into named constants
  with docs
* track a history of per-endpoint pong replies for future use &
  status display
* add "send" and " got" prefix to discovery message logging
  immediately before the frame type so it's easier to read than
  searching for the "<-" or "->" arrows earlier in the line; but keep
  those as the more reasily machine readable part for later.

Updates #483
2020-07-03 11:26:22 -07:00
Brad Fitzpatrick
6c70cf7222 wgengine/magicsock: stop ping timeout timer on pong receipt, misc log cleanup
Updates #483
2020-07-02 22:54:57 -07:00
Brad Fitzpatrick
c52905abaa wgengine/magicsock: log less on no-op disco route switches
Also, renew trustBestAddrUntil even if latency isn't better.
2020-07-02 11:39:05 -07:00
Brad Fitzpatrick
0f0ed3dca0 wgengine/magicsock: clean up discovery logging
Updates #483
2020-07-02 10:48:13 -07:00
Brad Fitzpatrick
056fbee4ef wgengine/magicsock: add TS_DEBUG_OMIT_LOCAL_ADDRS knob to force STUN use only
For debugging.
2020-07-02 09:53:10 -07:00
Brad Fitzpatrick
e03cc2ef57 wgengine/magicsock: populate discoOfAddr upon receiving ping frames
Updates #483
2020-07-02 08:37:46 -07:00
Brad Fitzpatrick
275a20f817 wgengine/magicsock: keep discoOfAddr populated, use it for findEndpoint
Update the mapping from ip:port to discokey, so when we retrieve a
packet from the network, we can find the same conn.Endpoint that we
gave to wireguard-go previously, without making it think we've
roamed. (We did, but we're not using its roaming.)

Updates #483
2020-07-01 22:15:41 -07:00
Brad Fitzpatrick
77e89c4a72 wgengine/magicsock: handle CallMeMaybe discovery mesages
Roughly feature complete now. Testing and polish remains.

Updates #483
2020-07-01 15:30:25 -07:00
Brad Fitzpatrick
710ee88e94 wgengine/magicsock: add timeout on discovery pings, clean up state
Updates #483
2020-07-01 14:39:21 -07:00
Brad Fitzpatrick
77d3ef36f4 wgengine/magicsock: hook up discovery messages, upgrade to LAN works
Ping messages now go out somewhat regularly, pong replies are sent,
and pong replies are now partially handled enough to upgrade off DERP
to LAN.

CallMeMaybe packets are sent & received over DERP, but aren't yet
handled. That's next (and regular maintenance timers), and then WAN
should work.

Updates #483
2020-07-01 13:00:50 -07:00
Brad Fitzpatrick
9b8ca219a1 wgengine/magicsock: remove allocs in UDP write, use new netaddr.PutUDPAddr
The allocs were only introduced yesterday with a TODO. Now they're gone again.
2020-07-01 10:17:08 -07:00
Brad Fitzpatrick
7b3c0bb7f6 wgengine/magicsock: fix crash reading DERP packet
Starting at yesterday's e96f22e560 (convering some UDPAddrs to
IPPorts), Conn.ReceiveIPv4 could return a nil addr, which would make
its way through wireguard-go and blow up later. The DERP read path
wasn't initializing the addr result parameter any more, and wgRecvAddr
wasn't checking it either.

Fixes #515
2020-07-01 09:36:19 -07:00
Brad Fitzpatrick
47b4a19786 wgengine/magicsock: use netaddr.ParseIPPort instead of net.ResolveUDPAddr 2020-07-01 08:23:37 -07:00
Brad Fitzpatrick
f7124c7f06 wgengine/magicsock: start of discoEndpoint state tracking
Updates #483
2020-06-30 15:33:56 -07:00
Brad Fitzpatrick
92252b0988 wgengine/magicsock: add a little LRU cache for netaddr.IPPort lookups
And while plumbing, a bit of discovery work I'll need: the
endpointOfAddr map to map from validated paths to the discoEndpoint.
Not being populated yet.

Updates #483
2020-06-30 14:38:10 -07:00
Brad Fitzpatrick
2d6e84e19e net/netcheck, wgengine/magicsock: replace more UDPAddr with netaddr.IPPort 2020-06-30 13:25:13 -07:00
Brad Fitzpatrick
9070aacdee wgengine/magicsock: minor comments & logging & TODO changes 2020-06-30 13:14:41 -07:00
Brad Fitzpatrick
e96f22e560 wgengine/magicsock: start handling disco message, use netaddr.IPPort more
Updates #483
2020-06-30 12:24:23 -07:00
Brad Fitzpatrick
a83ca9e734 wgengine/magicsock: cache precomputed nacl/box shared keys
Updates #483
2020-06-29 14:26:25 -07:00
Brad Fitzpatrick
a975e86bb8 wgengine/magicsock: add new endpoint type used for discovery-supporting peers
This adds a new magicsock endpoint type only used when both sides
support discovery (that is, are advertising a discovery
key). Otherwise the old code is used.

So far the new code only communicates over DERP as proof that the new
code paths are wired up. None of the actually discovery messaging is
implemented yet.

Support for discovery (generating and advertising a key) are still
behind an environment variable for now.

Updates #483
2020-06-29 13:59:54 -07:00
Brad Fitzpatrick
103c06cc68 wgengine/magicsock: open discovery naclbox messages from known peers
And track known peers.

Doesn't yet do anything with the messages. (nor does it send any yet)

Start of docs on the message format. More will come in subsequent changes.

Updates #483
2020-06-26 14:57:12 -07:00
Brad Fitzpatrick
23e74a0f7a wgengine, magicsock, tstun: don't regularly STUN when idle (mobile only for now)
If there's been 5 minutes of inactivity, stop doing STUN lookups. That
means NAT mappings will expire, but they can resume later when there's
activity again.

We'll do this for all platforms later.

Updates tailscale/corp#320

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-06-25 19:14:24 -07:00
Brad Fitzpatrick
fe50cd0c48 ipn, wgengine: plumb NetworkMap down to magicsock
Now we can have magicsock make decisions based on tailcfg.Debug
settings sent by the server.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-06-25 19:14:24 -07:00
Dmytro Shynkevych
de5f6d70a8 magicsock: eliminate logging race in test
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
2020-06-22 11:06:12 -04:00
Brad Fitzpatrick
53fb25fc2f all: generate discovery key, plumb it around
Not actually used yet.

Updates #483
2020-06-19 12:12:00 -07:00
Brad Fitzpatrick
abd79ea368 derp: reduce DERP memory use; don't require callers to pass in memory to use
The magicsock derpReader was holding onto 65KB for each DERP
connection forever, just in case.

Make the derp{,http}.Client be in charge of memory instead. It can
reuse its bufio.Reader buffer space.
2020-06-15 10:26:50 -07:00
Brad Fitzpatrick
280e8884dd wgengine/magicsock: limit redundant log spam on packets from low-pri addresses
Fixes #407

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-06-11 09:40:55 -07:00
Brad Fitzpatrick
9e5d79e2f1 wgengine/magicsock: drop a bytes.Buffer sync.Pool, use logger.ArgWriter instead 2020-05-31 15:29:04 -07:00
Brad Fitzpatrick
becce82246 net/netns, misc tests: remove TestOnlySkipPrivilegedOps, argv checks
The netns UID check is sufficient for now. We can do something else
later if/when needed.
2020-05-31 14:40:18 -07:00
David Anderson
5114df415e net/netns: set the bypass socket mark on linux.
This allows tailscaled's own traffic to bypass Tailscale-managed routes,
so that things like tailscale-provided default routes don't break
tailscaled itself.

Progress on #144.

Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-29 15:16:58 -07:00
Brad Fitzpatrick
db2a216561 wgengine/magicsock: don't log on UDP send errors if address family known missing
Fixes #376
2020-05-29 12:41:30 -07:00
Brad Fitzpatrick
9e3ad4f79f net/netns: add package for start of network namespace support
And plumb in netcheck STUN packets.

TODO: derphttp, logs, control.

Updates #144

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-05-28 16:20:16 -07:00
Brad Fitzpatrick
a428656280 wgengine/magicsock: don't report v4 localhost addresses on IPv6-only systems
Updates #376
2020-05-28 14:16:23 -07:00
Avery Pennarun
30e5c19214 magicsock: work around race condition initializing .Regions[].
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
2020-05-28 03:42:03 -04:00
Brad Fitzpatrick
b0c10fa610 stun, netcheck: move under net 2020-05-25 09:18:24 -07:00
Brad Fitzpatrick
e6b84f2159 all: make client use server-provided DERP map, add DERP region support
Instead of hard-coding the DERP map (except for cmd/tailscale netcheck
for now), get it from the control server at runtime.

And make the DERP map support multiple nodes per region with clients
picking the first one that's available. (The server will balance the
order presented to clients for load balancing)

This deletes the stunner package, merging it into the netcheck package
instead, to minimize all the config hooks that would've been
required.

Also fix some test flakes & races.

Fixes #387 (Don't hard-code the DERP map)
Updates #388 (Add DERP region support)
Fixes #399 (wgengine: flaky tests)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-05-23 22:31:59 -07:00
David Anderson
e8b3a5e7a1 wgengine/filter: implement a destination IP pre-filter.
Signed-off-by: David Anderson <danderson@tailscale.com>
2020-05-22 17:03:30 +00:00
Brad Fitzpatrick
e6d0c92b1d wgengine/magicsock: clean up earlier fix a bit
Move WaitReady from fc88e34f42 into the
test code, and keep the derp-reading goroutine named for debugging.
2020-05-14 10:01:48 -07:00
Avery Pennarun
fc88e34f42 wgengine/magicsock/tests: wait for home DERP connection before sending packets.
This fixes an elusive test flake. Fixes #161.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
2020-05-13 23:50:25 -04:00
Avery Pennarun
4f128745d8 magicsock/test: oops, fix a data race in nested-test logf hack.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
2020-05-13 23:50:09 -04:00
Avery Pennarun
42a0e0c601 wgengine/magicsock/tests: call tstest.ResourceCheck for each test.
This didn't catch anything yet, but it's good practice for detecting
goroutine leaks that we might not find otherwise.

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
2020-05-13 23:17:51 -04:00