Two optimizations.
Use values instead of pointers.
We were using pointers to make track the "peer in progress" easier.
It's not too hard to do it manually, though.
Make two passes through the data, so that we can size our
return value accurately from the beginning.
This is cheap enough compared to the allocation,
which grows linearly in the number of peers,
that it is worth doing.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
The netmaps can get really large.
Printing, processing, and uploading them is expensive.
Only print the header on an ongoing basis.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
The number of packet filters can grow very large,
so this log entry can be very large.
We can get the packet filter server-side,
so reduce verbosity here to just the number of filters present.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
The code goes to some effort to send a single JSON object
when there's only a single line and a JSON array when there
are multiple lines.
It makes the code more complex and more expensive;
when we add a second line, we have to use a second buffer
to duplicate the first one after adding a leading square brackets.
The savings come to two bytes. Instead, always send an array.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Scanning log lines is a frequent source of allocations.
Pre-allocate a re-usable buffer.
This still doesn't help when there are giant log lines.
Those will still be problematic from an iOS memory perspective.
For more on that, see https://github.com/tailscale/corp/issues/2423.
(For those who cannot follow that link, it is a discussion
of particular problematic types of log lines for
particular categories of customers. The "categories of customers"
part is the reason that it is a private issue.)
There is also a latent bug here. If we ever encounter
a log line longer than bufio.MaxScanTokenSize,
then bufio.Scan will return an error,
and we'll truncate the file and discard the rest of the log.
That's not good, but bufio.MaxScanTokenSize is really big,
so it probably doesn't matter much in practice now.
Unfortunately, it does prevent us from easily capping the potential
memory usage here, on pain of losing log entries.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Prior to Go 1.16, iOS used GOOS=darwin,
so we had to distinguish macOS from iOS during GOARCH.
We now require Go 1.16 in our go.mod, so we can simplify.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Now that we have the easier-to-parse go:build build tags,
it is straightforward to simplify them. Yay.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Mostly so the Linux one can use Linux-specific stuff in package
syscall and not use os/exec for uname for portability.
But also it helps deps a tiny bit on iOS.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Allows FreeBSD to function as an exit node in the same way
that Windows and Tailscaled-on-MacOS do.
RELNOTE=FreeBSD can now function as an exit node.
Fixes https://github.com/tailscale/tailscale/issues/2498
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
Not even close to usable or well integrated yet, but submitting this before
it bitrots or I lose it.
Updates #1235
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This logs some basic statistics for UPnP, so that tailscale can better understand what routers
are being used and how to connect to them.
Signed-off-by: julianknodt <julianknodt@gmail.com>
This adds a PCP test to the IGD test server, by hardcoding in a few observed packets from
Denton's box.
Signed-off-by: julianknodt <julianknodt@gmail.com>
We want to use tsweb to format Prometheus-style metrics from
our temporary golang.org/x/net/http2 fork, but we don't want http2
to depend on the tailscale.com module to use the concrete type
tailscale.com/metrics.LabelMap. Instead, let a expvar.Map be used
instead of it's annotated sufficiently in its name.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
rsc.io/goversion is really expensive.
Running version.ReadExe on tailscaled on darwin
allocates 47k objects, almost 11mb.
All we want is the module info. For that, all we need to do
is scan through the binary looking for the magic start/end strings
and then grab the bytes in between them.
We can do that easily and quickly with nothing but a 64k buffer.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
And use dynamic port numbers in tests, as Linux on GitHub Actions and
Windows in general have things running on these ports.
Co-Author: Julian Knodt <julianknodt@gmail.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Previously, we hashed the question and combined it with the original
txid which was useful when concurrent queries were multiplexed on a
single local source port. We encountered some situations where the DNS
server canonicalizes the question in the response (uppercase converted
to lowercase in this case), which resulted in responses that we couldn't
match to the original request due to hash mismatches. This includes a
new test to cover that situation.
Fixes#2597
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
