Commit graph

711 commits

Author SHA1 Message Date
Josh Bleecher Snyder 85b4950579 device: add latency and throughput benchmarks
These obviously don't perfectly capture real world performance,
in which syscalls and network links have a significant impact.
Nevertheless, they capture some of the internal performance factors,
and they're easy and convenient to work with.

Hat tip to Avery Pennarun for help designing the throughput benchmark.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder 8a30415555 device: use LogLevelError for benchmarking
This keeps the output minimal and focused on the benchmark results.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder cdaf4e9a76 device: make test infrastructure usable with benchmarks
Switch from *testing.T to testing.TB.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Jason A. Donenfeld 3d83df9bf3 memmod: apply explicit build tags to _32 and _64 files
Since _32 and _64 aren't valid goarchs, they don't match _GOOS_GOARCH,
and so the existing tags wind up not being restricted to windows-only.
This fixes the problem by adding windows to the tags explicitly. We
could also fix it by calling the files _32_windows or _64_windows, but
that changes the convention with the other single-arch files.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-01-07 14:49:44 +01:00
Jason A. Donenfeld d664444928 tun: make customization of WintunPool and requested GUID more obvious
Persnickety consumers can now do:

    func init() {
        tun.WintunPool, _ = wintun.MakePool("Flurp")
        tun.WintunStaticRequestedGUID, _ = windows.GUIDFromString("{5ae2716f-0b3e-4dc4-a8b5-48eba11a6e16}")
    }

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder 1481e72107 all: use ++ to increment
Make the code slightly more idiomatic. No functional changes.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder d0f8e9477c device: remove unnecessary zeroing
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder b42e32047d device: call wg.Add outside the goroutine
One of the first rules of WaitGroups is that you call wg.Add
outside of a goroutine, not inside it. Fix this embarrassing mistake.

This prevents an extremely rare race condition (2 per 100,000 runs)
which could occur when attempting to start a new peer
concurrently with shutting down a device.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder b5f966ac24 device: remove QueueInboundElement leak with stopped peers
This is particularly problematic on mobile,
where there is a fixed number of elements.
If most of them leak, it'll impact performance;
if all of them leak, the device will permanently deadlock.

I have a test that detects element leaks, which is how I found this one.
There are some remaining leaks that I have not yet tracked down,
but this is the most prominent by far.

I will commit the test when it passes reliably.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder a1c265b0c5 device: simplify UAPI helper methods
bufio is not required.

strings.Builder is cheaper than bytes.Buffer for constructing strings.

io.Writer is more flexible than io.StringWriter,
and just as cheap (when used with io.WriteString).

Run gofmt.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Jason A. Donenfeld 25b01723dd device: fix alignment of peer stats member
This was shifted by 2 bytes when making persistent keepalive into a u32.
Fix it by placing it after the aligned region.

Fixes: e739ff7 ("device: fix persistent_keepalive_interval data races")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-01-07 14:49:44 +01:00
Jason A. Donenfeld 40dfc85def device: add UAPI helper methods
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-01-07 14:49:44 +01:00
Jason A. Donenfeld 890cc06ed5 conn: do not SO_REUSEADDR on linux
SO_REUSEADDR does not make sense for unicast UDP sockets.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-01-07 14:49:44 +01:00
Jason A. Donenfeld ad73ee78e9 device: add missing colon to error line
People are actually hitting this condition, so make it uniform. Also,
change a printf into a println, to match the other conventions.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-01-07 14:49:44 +01:00
Brad Fitzpatrick e9edc16349 device: fix error shadowing before log print
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder f7bbdc31a0 device: fix data race in peer.timersActive
Found by the race detector and existing tests.

To avoid introducing a lock into this hot path,
calculate and cache whether any peers exist.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder 70861686d3 device: fix races from changing private_key
Access keypair.sendNonce atomically.
Eliminate one unnecessary initialization to zero.

Mutate handshake.lastSentHandshake with the mutex held.

Co-authored-by: David Anderson <danderson@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder c8faa34cde device: always name *Queue*Element variables elem
They're called elem in most places.
Rename a few local variables to make it consistent.
This makes it easier to grep the code for things like elem.Drop.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder 2832e96339 device: use channel close to shut down and drain outbound channel
This is a similar treatment to the handling of the encryption
channel found a few commits ago: Use the closing of the channel
to manage goroutine lifetime and shutdown.
It is considerably simpler because there is only a single writer.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder 63066ce406 device: fix persistent_keepalive_interval data races
Co-authored-by: David Anderson <danderson@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder e1fa1cc556 device: use channel close to shut down and drain encryption channel
The new test introduced in this commit used to deadlock about 1% of the time.

I believe that the deadlock occurs as follows:

* The test completes, calling device.Close.
* device.Close closes device.signals.stop.
* RoutineEncryption stops.
* The deferred function in RoutineEncryption drains device.queue.encryption.
* RoutineEncryption exits.
* A peer's RoutineNonce processes an element queued in peer.queue.nonce.
* RoutineNonce puts that element into the outbound and encryption queues.
* RoutineSequentialSender reads that elements from the outbound queue.
* It waits for that element to get Unlocked by RoutineEncryption.
* RoutineEncryption has already exited, so RoutineSequentialSender blocks forever.
* device.RemoveAllPeers calls peer.Stop on all peers.
* peer.Stop waits for peer.routines.stopping, which blocks forever.

Rather than attempt to add even more ordering to the already complex
centralized shutdown orchestration, this commit moves towards a
data-flow-oriented shutdown.

The device.queue.encryption gets closed when there will be no more writes to it.
All device.queue.encryption readers always read until the channel is closed and then exit.
We thus guarantee that any element that enters the encryption queue also exits it.
This removes the need for central control of the lifetime of RoutineEncryption,
removes the need to drain the encryption queue on shutdown, and simplifies RoutineEncryption.

This commit also fixes a data race. When RoutineSequentialSender
drains its queue on shutdown, it needs to lock the elem before operating on it,
just as the main body does.

The new test in this commit passed 50k iterations with the race detector enabled
and 150k iterations with the race detector disabled, with no failures.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder 41cd68416c device: simplify copying counter to nonce
Since we already have it packed into a uint64
in a known byte order, write it back out again
the same byte order instead of copying byte by byte.

This should also generate more efficient code,
because the compiler can do a single uint64 write,
instead of eight bounds checks and eight byte writes.

Due to a missed optimization, it actually generates a mishmash
of smaller writes: 1 byte, 4 bytes, 2 bytes, 1 byte.
This is https://golang.org/issue/41663.
The code is still better than before, and will get better yet
once that compiler bug gets fixed.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder 94b33ba705 device: add a helper to generate uapi configs
This makes it easier to work with configs in tests.
It'll see heavier use over upcoming commits;
this commit only adds the infrastructure.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder ea8fbb5927 device: use defer to simplify peer.NewTimer
This also makes the lifetime of modifyingLock more prominent.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder 93a4313c3a device: accept any io.Reader in device.IpcSetOperation
Any io.Reader will do, and there are no performance concerns here.
This is technically backwards incompatible,
but it is very unlikely to break any existing code.
It is compatible with the existing uses in wireguard-{windows,android,apple}
and also will allow us to slightly simplify it if desired.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder db1edc7e91 device: increase timeout in tests
When running many concurrent test processing using
https://godoc.org/golang.org/x/tools/cmd/stress
the processing sometimes cannot complete a ping in under 300ms.
Increase the timeout to 5s to reduce the rate of false positives.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder fc0aabbae9 device: prevent spurious errors while closing a device
When closing a device, packets that are in flight
can make it to SendBuffer, which then returns an error.
Those errors add noise but no light;
they do not reflect an actual problem.

Adding the synchronization required to prevent
this from occurring is currently expensive and error-prone.
Instead, quietly drop such packets instead of
returning an error.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder c9e4a859ae device: remove starting waitgroups
In each case, the starting waitgroup did nothing but ensure
that the goroutine has launched.

Nothing downstream depends on the order in which goroutines launch,
and if the Go runtime scheduler is so broken that goroutines
don't get launched reasonably promptly, we have much deeper problems.

Given all that, simplify the code.

Passed a race-enabled stress test 25,000 times without failure.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder 3591acba76 device: make test setup more robust
Picking two free ports to use for a test is difficult.
The free port we selected might no longer be free when we reach
for it a second time.

On my machine, this failure mode led to failures approximately
once per thousand test runs.

Since failures are rare, and threading through and checking for
all possible errors is complicated, fix this with a big hammer:
Retry if either device fails to come up.

Also, if you accidentally pick the same port twice, delightful confusion ensues.
The handshake failures manifest as crypto errors, which look scary.
Again, fix with retries.

To make these retries easier to implement, use testing.T.Cleanup
instead of defer to close devices. This requires Go 1.14.
Update go.mod accordingly. Go 1.13 is no longer supported anyway.

With these fixes, 'go test -race' ran 100,000 times without failure.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:44 +01:00
Jason A. Donenfeld ca9edf1c63 wintun: do not load dll in init()
This prevents linking to wintun.dll until it's actually needed, which
should improve startup time.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-01-07 14:49:44 +01:00
Josh Bleecher Snyder 347ce76bbc tun/tuntest: make genICMPv4 allocate less
It doesn't really matter, because it is only used in tests,
but it does remove some noise from pprof profiles.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-01-07 14:49:37 +01:00
Josh Bleecher Snyder c4895658e6 device: avoid copying lock in tests
This doesn't cause any practical problems as it is,
but vet (rightly) flags this code as copying a mutex.
It is easy to fix, so do so.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-12-08 14:25:10 -08:00
Josh Bleecher Snyder d3ff2d6b62 device: clear pointers when returning elems to pools
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-12-08 14:25:02 -08:00
Josh Bleecher Snyder 01d3aaa7f4 device: use labeled for loop instead of goto
Minor code cleanup; no functional changes.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2020-12-08 14:24:20 -08:00
Jason A. Donenfeld b6303091fc memmod: fix import loading function usage
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-11-27 13:13:45 +01:00
Simon Rozman c9fabbd5bf wintun: log when reboot is suggested by Windows
Which really shouldn't happen. But it is a useful information for
troubleshooting.

Signed-off-by: Simon Rozman <simon@rozman.si>
2020-11-25 13:58:11 +01:00
Simon Rozman 4cc7a7a455 wintun: keep original error when Wintun session start fails
Signed-off-by: Simon Rozman <simon@rozman.si>
2020-11-25 13:57:05 +01:00
Jason A. Donenfeld da19db415a version: bump snapshot 2020-11-18 14:24:17 +01:00
Jason A. Donenfeld 52c834c446 mod: bump
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-11-18 14:24:00 +01:00
Haichao Liu 913f68ce38 device: add write queue mutex for peer
fix panic: send on closed channel when remove peer

Signed-off-by: Haichao Liu <liuhaichao@bytedance.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-11-18 14:22:15 +01:00
Jason A. Donenfeld 60b3766b89 wintun: load from filesystem by default
We let people loading this from resources opt in via:

    go build -tags load_wintun_from_rsrc

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-11-11 18:51:44 +01:00
Jason A. Donenfeld 82128c47d9 global: switch to using %w instead of %v for Errorf
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-11-07 21:56:32 +01:00
Jason A. Donenfeld c192b2eeec mod: update deps
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-11-07 15:22:18 +01:00
Simon Rozman a3b231b31e wintun: ring management moved to wintun.dll
Signed-off-by: Simon Rozman <simon@rozman.si>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-11-07 15:20:49 +01:00
Simon Rozman 65e03a9182 wintun: load wintun.dll from RCDATA resource
Signed-off-by: Simon Rozman <simon@rozman.si>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-11-07 15:20:49 +01:00
Simon Rozman 3e08b8aee0 wintun: migrate to wintun.dll API
Rather than having every application using Wintun driver reinvent the
wheel, the Wintun device/adapter/interface management has been moved
from wireguard-go to wintun.dll deployed with Wintun itself.

Signed-off-by: Simon Rozman <simon@rozman.si>
2020-11-07 12:46:35 +01:00
Jason A. Donenfeld 5ca1218a5c device: format a few things
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-11-06 18:01:27 +01:00
Tobias Klauser 3b490f30aa tun: use SockaddrCtl from golang.org/x/sys/unix on macOS
Direct syscalls using unix.Syscall(unix.SYS_*, ...) are discouraged on
macOS and might not be supported in future versions. Switch to use
unix.Connect with unix.SockaddrCtl instead.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-10-27 16:20:09 +01:00
Tobias Klauser e6b7c4eef3 tun: use Ioctl{Get,Set}IfreqMTU from golang.org/x/sys/unix on macOS
Direct syscalls using unix.Syscall(unix.SYS_*, ...) are discouraged on
macOS and might not be supported in future versions. Switch to use
unix.Ioctl{Get,Set}IfreqMTU to get and set an interface's MTU.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-10-27 16:20:09 +01:00
Tobias Klauser 8ae09213a7 tun: use IoctlCtlInfo from golang.org/x/sys/unix on macOS
Direct syscalls using unix.Syscall(unix.SYS_*, ...) are discouraged on
macOS and might not be supported in future versions. Switch to use
unix.IoctlCtlInfo to get the kernel control info.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-10-27 16:20:09 +01:00