The previous algorithm used a map of all visited pointers.
The strength of this approach is that it quickly prunes any nodes
that we have ever visited before. The detriment of the approach
is that pruning is heavily dependent on the order that pointers
were visited. This is especially relevant for hashing a map
where map entries are visited in a non-deterministic manner,
which would cause the map hash to be non-deterministic
(which defeats the point of a hash).
This new algorithm uses a stack of all visited pointers,
similar to how github.com/google/go-cmp performs cycle detection.
When we visit a pointer, we push it onto the stack, and when
we leave a pointer, we pop it from the stack.
Before visiting a pointer, we first check whether the pointer exists
anywhere in the stack. If yes, then we prune the node.
The detriment of this approach is that we may hash a node more often
than before since we do not prune as aggressively.
The set of visited pointers up until any node is only the
path of nodes up to that node and not any other pointers
that may have been visited elsewhere. This provides us
deterministic hashing regardless of visit order.
We can now delete hashMapFallback and associated complexity,
which only exists because the previous approach was non-deterministic
in the presence of cycles.
This fixes a failure of the old algorithm where obviously different
values are treated as equal because the pruning was too aggresive.
See https://github.com/tailscale/tailscale/issues/2443#issuecomment-883653534
The new algorithm is slightly slower since it prunes less aggresively:
name old time/op new time/op delta
Hash-8 66.1µs ± 1% 68.8µs ± 1% +4.09% (p=0.000 n=19+19)
HashMapAcyclic-8 63.0µs ± 1% 62.5µs ± 1% -0.76% (p=0.000 n=18+19)
TailcfgNode-8 9.79µs ± 2% 9.88µs ± 1% +0.95% (p=0.000 n=19+17)
HashArray-8 643ns ± 1% 653ns ± 1% +1.64% (p=0.000 n=19+19)
However, a slower but more correct algorithm seems
more favorable than a faster but incorrect algorithm.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This prevents centos tests from timing out because sshd does reverse dns
lookups on every session being established instead of doing it once on
the acutal ssh connection being established. This is odd. Appending this
to the sshd config and restarting it seems to fix it though.
Signed-off-by: Christine Dodrill <xe@tailscale.com>
TCP was done in 662fbd4a09.
This does the same for UDP.
Tested by hand. Integration tests will have to come later. I'd wanted
to do it in this commit, but the SOCKS5 server needed for interop
testing between two userspace nodes doesn't yet support UDP and I
didn't want to invent some whole new userspace packet injection
interface at this point, as SOCKS seems like a better route, but
that's its own bug.
Fixes#2302
RELNOTE=netstack mode can now UDP relay to subnets
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
A Go interface may hold any number of different concrete types.
Just because two underlying values hash to the same thing
does not mean the two values are identical if they have different
concrete types. As such, include the type in the hash.
Previously, this was incorrectly returning the internal port, and using that with the external
exposed IP when it did not use WANIPConnection2. In the case when we must provide a port, we
return it instead.
Noticed this while implementing the integration test for upnp.
Signed-off-by: julianknodt <julianknodt@gmail.com>
Seed the hash upon first use with the current time.
This ensures that the stability of the hash is bounded within
the lifetime of one program execution.
Hopefully, this prevents future bugs where someone assumes that
this hash is stable.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Filch doesn't like having multiple processes competing
for the same log files (#937).
Parallel integration tests were all using the same log files.
Add a TS_LOGS_DIR env var that the integration test can use
to use separate log files per test.
Fixes#2269
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Prep for #1591 which will need to make Linux's router react to changes
that the link monitor observes.
The router package already depended on the monitor package
transitively. Now it's explicit.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Instead of logging lsof execution failures to stdout,
incorporate them into the returned error.
While we're here, make it clear that the file
success case always returns a nil error.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
The maximum unix domain socket path length on darwin is 104 bytes,
including the trailing NUL.
On my machine, the path created by some newly added tests (6eecf3c9)
was too long, resulting in cryptic test failures.
Shorten the names of the tests, and add a check to make
the diagnosis easier next time.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
The fact that Hash returns a [sha256.Size]byte leaks details about
the underlying hash implementation. This could very well be any other
hashing algorithm with a possible different block size.
Abstract this implementation detail away by declaring an opaque type
that is comparable. While we are changing the signature of UpdateHash,
rename it to just Update to reduce stutter (e.g., deephash.Update).
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
It was a huge chunk of the overall log output and made debugging
difficult. Omit and summarize the spammy *.arpa parts instead.
Fixestailscale/corp#2066 (to which nobody had opinions, so)
With this, I can now:
* install Tailscale
* stop the GUI
* net stop Tailscale
* net start Tailscale
* tailscale up --unattended
(where the middle three steps simulate what would happen on a Windows
Server Core machine without a GUI)
Fixes#2137
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
To unify the Windows service and non-service/non-Windows paths a bit.
And provides a way to make Linux act like Windows for testing.
(notably, for testing the fix to #2137)
One perhaps visible change of this is that tailscaled.exe when run in
cmd.exe/powershell (not as a Windows Service) no longer uses the
"_daemon" autostart key. But in addition to being naturally what falls
out of this change, that's also what Windows users would likely want,
as otherwise the unattended mode user is ignored when the "_daemon"
autostart key is specified. Notably, this would let people debug what
their normally-run-as-a-service tailscaled is doing, even when they're
running in Unattended Mode.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Adds TS_DEBUG_UP_FLAG_GOOS for integration tests to make "tailscale
up" act like other OSes.
For an upcoming change to test #2137.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We have different deps depending on the platform.
If we pick a privileged platform, we'll miss some deps.
If we use the union of all platforms, the integration test
won't compile on some platforms, because it'll import
packages that don't compile on that platform.
Give in to the madness and give each platform its own deps file.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
The earlier 2ba36c294b started listening
for ip rule changes and only cared about DELRULE events, buts its subscription
included all rule events, including new ones, which meant we were then
catching our own ip rule creations and logging about how they were unknown.
Stop that log spam.
Updates #1591
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
For debugging & working on #1591 where certain versions of systemd-networkd
delete Tailscale's ip rule entries.
Updates #1591
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This moves the distribution definitions into a maintainable hujson file
instead of just existing as constants in `distros.go`. Comments are
maintained from the inline definitions.
This uses jennifer[1] for hygenic source tree creation. This allows us
to generate a unique top-level test for each VM run. This should
hopefully help make the output of `go test` easier to read.
This also separates each test out into its own top-level test so that we
can better track the time that each distro takes. I really wish there
was a way to have the `test_codegen.go` file _always_ run as a part of
the compile process instead of having to rely on people remembering to
run `go generate`, but I am limited by my tools.
This will let us remove the `-distro-regex` flag and use `go test -run`
to pick which distros are run.
Signed-off-by: Christine Dodrill <xe@tailscale.com>
Add in UPnP portmapping, using goupnp library in order to get the UPnP client and run the
portmapping functions. This rips out anywhere where UPnP used to be in portmapping, and has a
flow separate from PMP and PCP.
RELNOTE=portmapper now supports UPnP mappings
Fixes#682
Updates #2109
Signed-off-by: julianknodt <julianknodt@gmail.com>
Recognize Cloudflare, Google, Quad9 which are by far the
majority of upstream DNS servers that people use.
RELNOTE=MagicDNS now uses DNS-over-HTTPS when querying popular upstream resolvers,
so DNS queries aren't sent in the clear over the Internet.
Updates #915 (might fix it?)
Updates #988 (gets us closer, if it fixes Android)
Updates #74 (not yet configurable, but progress)
Updates #2056 (not yet configurable, dup of #74?)
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Added the net/speedtest package that contains code for starting up a
speedtest server and a client. The speedtest command for starting a
client takes in a duration for the speedtest as well as the host and
port of the speedtest server to connect to. The speedtest command for
starting a server takes in a host:port pair to listen on.
Signed-off-by: Aaditya Chaudhary <32117362+AadityaChaudhary@users.noreply.github.com>
Apparently this test was flaking because I critically misunderstood how
the kernel buffers UDP packets for senders. I'm trying to send more UDP
packets and will see if that helps.
Signed-off-by: Christine Dodrill <xe@tailscale.com>
