Running hex.Encode(b, b) is a bad idea.
The first byte of input will overwrite the first two bytes of output.
Subsequent bytes have no impact on the output.
Not related to today's IPv6 bug, but...wh::ps.
This caused us to spuriously ignore some wireguard config updates.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Reduce to just a single external endpoint.
Convert from a variadic number of interfaces to a slice there.
name old time/op new time/op delta
Hash-8 14.4µs ± 0% 14.0µs ± 1% -3.08% (p=0.000 n=9+9)
name old alloc/op new alloc/op delta
Hash-8 873B ± 0% 793B ± 0% -9.16% (p=0.000 n=9+6)
name old allocs/op new allocs/op delta
Hash-8 18.0 ± 0% 14.0 ± 0% -22.22% (p=0.000 n=10+10)
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Hash and xor each entry instead, then write final xor'ed result.
name old time/op new time/op delta
Hash-4 33.6µs ± 4% 34.6µs ± 3% +3.03% (p=0.013 n=10+9)
name old alloc/op new alloc/op delta
Hash-4 1.86kB ± 0% 1.77kB ± 0% -5.10% (p=0.000 n=10+9)
name old allocs/op new allocs/op delta
Hash-4 51.0 ± 0% 49.0 ± 0% -3.92% (p=0.000 n=10+10)
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Typical maps in production are considerably longer.
This helps benchmarks more accurately reflect the costs per key
vs the costs per map in deephash.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
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>
Yes, it printed, but that was an implementation detail for hashing.
And coming optimization will make it print even less.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The sha256 hash writer doesn't implement WriteString.
(See https://github.com/golang/go/issues/38776.)
As a consequence, we end up converting many strings to []byte.
Wrapping a bufio.Writer around the hash writer lets us
avoid these conversions by using WriteString.
Using a bufio.Writer is, perhaps surprisingly, almost as cheap as using unsafe.
The reason is that the sha256 writer does internal buffering,
but doesn't do any when handed larger writers.
Using a bufio.Writer merely shifts the data copying from one buffer
to a different one.
Using a concrete type for Print and print cuts 10% off of the execution time.
name old time/op new time/op delta
Hash-8 15.3µs ± 0% 11.5µs ± 0% -24.84% (p=0.000 n=10+10)
name old alloc/op new alloc/op delta
Hash-8 2.82kB ± 0% 1.98kB ± 0% -29.57% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
Hash-8 140 ± 0% 82 ± 0% -41.43% (p=0.000 n=10+10)
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
deepprint currently accounts for 15% of allocs in tailscaled.
This is a useful benchmark to have.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
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>
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>
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>
The new deepprint package just walks a Go data structure and writes to
an io.Writer. It's not pretty like go-spew, etc.
We then use it to replace the use of UAPI (which we have a TODO to
remove) to generate signatures of data structures to detect whether
anything changed (without retaining the old copy).
This was necessary because the UAPI conversion ends up trying to do
DNS lookups which an upcoming change depends on not happening.
Brad Fitzpatrick
Josh Bleecher Snyder
Josh Bleecher Snyder
David Anderson
Dmytro Shynkevych