This allows sending logs from the "logpolicy" package (and associated
callees) to something other than the log package. The behaviour for
tailscaled remains the same, passing in log.Printf
Updates #8249
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ie1d43b75fa7281933d9225bffd388462c08a5f31
When performing a fallback DNS query, run the recursive resolver in a
separate goroutine and compare the results returned by the recursive
resolver with the results we get from "regular" bootstrap DNS. This will
allow us to gather data about whether the recursive DNS resolver works
better, worse, or about the same as "regular" bootstrap DNS.
Updates #5853
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ifa0b0cc9eeb0dccd6f7a3d91675fe44b3b34bd48
Previously it would wait for all tests to run before printing anything,
instead stream the results over a channel so that they can be emitted
immediately.
Updates #8493
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Previously it would only print the failures without providing
more information on which package the failures from.
This commit makes it so that it prints out the package information
as well as the attempt numbers.
```
➜ tailscale.com git:(main) ✗ go run ./cmd/testwrapper ./cmd/...
ok tailscale.com/cmd/derper
ok tailscale.com/cmd/k8s-operator
ok tailscale.com/cmd/tailscale/cli
ok tailscale.com/cmd/tailscaled
=== RUN TestFlakeRun
flakytest.go:38: flakytest: issue tracking this flaky test: https://github.com/tailscale/tailscale/issues/0
flakytest_test.go:41: First run in testwrapper, failing so that test is retried. This is expected.
--- FAIL: TestFlakeRun (0.00s)
FAIL tailscale.com/cmd/testwrapper/flakytest
Attempt #2: Retrying flaky tests:
ok tailscale.com/cmd/testwrapper/flakytest
```
Updates #8493
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This change is introducing new netfilterRunner interface and moving iptables manipulation to a lower leveled iptables runner.
For #391
Signed-off-by: KevinLiang10 <kevinliang@tailscale.com>
Redo the testwrapper to track and only retry flaky tests instead
of retrying the entire pkg. It also fails early if a non-flaky test fails.
This also makes it so that the go test caches are used.
Fixes#7975
Signed-off-by: Maisem Ali <maisem@tailscale.com>
In order to improve our ability to understand the state of policies and
registry settings when troubleshooting, we enumerate all values in all subkeys.
x/sys/windows does not already offer this, so we need to call RegEnumValue
directly.
For now we're just logging this during startup, however in a future PR I plan to
also trigger this code during a bugreport. I also want to log more than just
registry.
Fixes#8141
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
The client/tailscale is a stable-ish API we try not to break. Revert
the Client.CreateKey method as it was and add a new
CreateKeyWithExpiry method to do the new thing. And document the
expiry field and enforce that the time.Duration can't be between in
range greater than 0 and less than a second.
Updates #7143
Updates #8124 (reverts it, effectively)
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Adds a parameter for create key that allows a number of seconds
(less than 90) to be specified for new keys.
Fixes https://github.com/tailscale/tailscale/issues/7965
Signed-off-by: Matthew Brown <matthew@bargrove.com>
getSingleObject can return `nil, nil`, getDeviceInfo was not handling
that case which resulted in panics.
Fixes#7303
Signed-off-by: Maisem Ali <maisem@tailscale.com>
The retry logic was pathological in the following ways:
* If we restarted the logging service, any pending uploads
would be placed in a retry-loop where it depended on backoff.Backoff,
which was too aggresive. It would retry failures within milliseconds,
taking at least 10 retries to hit a delay of 1 second.
* In the event where a logstream was rate limited,
the aggressive retry logic would severely exacerbate the problem
since each retry would also log an error message.
It is by chance that the rate of log error spam
does not happen to exceed the rate limit itself.
We modify the retry logic in the following ways:
* We now respect the "Retry-After" header sent by the logging service.
* Lacking a "Retry-After" header, we retry after a hard-coded period of
30 to 60 seconds. This avoids the thundering-herd effect when all nodes
try reconnecting to the logging service at the same time after a restart.
* We do not treat a status 400 as having been uploaded.
This is simply not the behavior of the logging service.
Updates #tailscale/corp#11213
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
I noticed cmd/{cloner,viewer} didn't support structs with embedded
fields while working on a change in another repo. This adds support.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Chenyang Gao <gps949@outlook.com>
in commit 6e96744, the tsd system type has been added.
Which will cause the daemon will crash on some OSs (Windows, darwin and so on).
The root cause is that on those OSs, handleSubnetsInNetstack() will return true and set the conf.Router with a wrapper.
Later in NewUserspaceEngine() it will do subsystem set and found that early set router mismatch to current value, then panic.
This is part of an effort to clean up tailscaled initialization between
tailscaled, tailscaled Windows service, tsnet, and the mac GUI.
Updates #8036
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This holds back gvisor, kubernetes, goreleaser, and esbuild, which all
had breaking API changes.
Updates #8043
Updates #7381
Updates #8042 (updates u-root which adds deps)
Change-Id: I889759bea057cd3963037d41f608c99eb7466a5b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This change introduces address selection for wireguard only endpoints.
If a endpoint has not been used before, an address is randomly selected
to be used based on information we know about, such as if they are able
to use IPv4 or IPv6. When an address is initially selected, we also
initiate a new ICMP ping to the endpoints addresses to determine which
endpoint offers the best latency. This information is then used to
update which endpoint we should be using based on the best possible
route. If the latency is the same for a IPv4 and an IPv6 address, IPv6
will be used.
Updates #7826
Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
DERP doesn't support HTTP/2. If an HTTP/2 proxy was placed in front of
a DERP server requests would fail because the connection would
be initialized with HTTP/2, which the DERP client doesn't support.
Signed-off-by: Kyle Carberry <kyle@carberry.com>
This change adds a v6conn to the pinger to enable sending pings to v6
addrs.
Updates #7826
Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
We need to always specify tags when creating an AuthKey from an OAuth key.
Check for that, and reuse the `--advertise-tags` param.
Updates #7982
Signed-off-by: Maisem Ali <maisem@tailscale.com>
On some platforms (notably macOS and iOS) we look up the default
interface to bind outgoing connections to. This is both duplicated
work and results in logspam when the default interface is not available
(i.e. when a phone has no connectivity, we log an error and thus cause
more things that we will try to upload and fail).
Fixed by passing around a netmon.Monitor to more places, so that we can
use its cached interface state.
Fixes#7850
Updates #7621
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
We're using it in more and more places, and it's not really specific to
our use of Wireguard (and does more just link/interface monitoring).
Also removes the separate interface we had for it in sockstats -- it's
a small enough package (we already pull in all of its dependencies
via other paths) that it's not worth the extra complexity.
Updates #7621
Updates #7850
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This is a follow-up to #7905 that adds two more linters and fixes the corresponding findings. As per the previous PR, this only flags things that are "obviously" wrong, and fixes the issues found.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I8739bdb7bc4f75666a7385a7a26d56ec13741b7c
This adds an initial and intentionally minimal configuration for
golang-ci, fixes the issues reported, and adds a GitHub Action to check
new pull requests against this linter configuration.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I8f38fbc315836a19a094d0d3e986758b9313f163
Redoes the approach from #5550 and #7539 to explicitly pass in the logf
function, instead of having global state that can be overridden.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This also adds a bunch of tests for this function to ensure that we're
returning the proper IP(s) in all cases.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I0d9d57170dbab5f2bf07abdf78ecd17e0e635399
This splits Prometheus metric handlers exposed by tsweb into two
modules:
- `varz.Handler` exposes Prometheus metrics generated by our expvar
converter;
- `promvarz.Handler` combines our expvar-converted metrics and native
Prometheus metrics.
By default, tsweb will use the promvarz handler, however users can keep
using only the expvar converter. Specifically, `tailscaled` now uses
`varz.Handler` explicitly, which avoids a dependency on the
(heavyweight) Prometheus client.
Updates https://github.com/tailscale/corp/issues/10205
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
This provides an example of using native Prometheus metrics with tsweb.
Prober library seems to be the only user of PrometheusVar, so I am
removing support for it in tsweb.
Updates https://github.com/tailscale/corp/issues/10205
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
The handler will expose built-in process and Go metrics by default,
which currently duplicate some of the expvar-proxied metrics
(`goroutines` vs `go_goroutines`, `memstats` vs `go_memstats`), but as
long as their names are different, Prometheus server will just scrape
both.
This will change /debug/varz behaviour for most tsweb binaries, but
notably not for control, which configures a `tsweb.VarzHandler`
[explicitly](a5b5d5167f/cmd/tailcontrol/tailcontrol.go (L779))
Updates https://github.com/tailscale/corp/issues/10205
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
Make developing derp easier by:
1. Creating an envknob telling clients to use HTTP to connect to derp
servers, so devs don't have to acquire a valid TLS cert.
2. Creating an envknob telling clients which derp server to connect
to, so devs don't have to edit the ACLs in the admin console to add a
custom DERP map.
3. Explaining how the -dev and -a command lines args to derper
interact.
To use this:
1. Run derper with -dev.
2. Run tailscaled with TS_DEBUG_USE_DERP_HTTP=1 and
TS_DEBUG_USE_DERP_ADDR=localhost
This will result in the client connecting to derp via HTTP on port
3340.
Fixes#7700
Signed-off-by: Val <valerie@tailscale.com>
I realized that a lot of the problems that we're seeing around migration and
LocalBackend state can be avoided if we drive Windows pref migration entirely
from within tailscaled. By doing it this way, tailscaled can automatically
perform the migration as soon as the connection with the client frontend is
established.
Since tailscaled is already running as LocalSystem, it already has access to
the user's local AppData directory. The profile manager already knows which
user is connected, so we simply need to resolve the user's prefs file and read
it from there.
Of course, to properly migrate this information we need to also check system
policies. I moved a bunch of policy resolution code out of the GUI and into
a new package in util/winutil/policy.
Updates #7626
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
This adds the util/sysresources package, which currently only contains a
function to return the total memory size of the current system.
Then, we modify magicsock to scale the number of buffered DERP messages
based on the system's available memory, ensuring that we never use a
value lower than the previous constant of 32.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ib763c877de4d0d4ee88869078e7d512f6a3a148d
#7339 changed the root directory logic to find the ancestor of the cwd
with a go.mod file. This works when running the the binary from this
repo directly, but breaks when we're a dependency in another repo.
Allow the directory to be passed in via a -rootdir flag (the repo that
depends on it can then use `go list -m -f '{{.Dir}}' tailscale.com`
or similar to pass in the value).
Updates tailscale/corp#10165
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
When running a SOCKS or HTTP proxy, configure the tshttpproxy package to
drop those addresses from any HTTP_PROXY or HTTPS_PROXY environment
variables.
Fixes#7407
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I6cd7cad7a609c639780484bad521c7514841764b
This adds support to make exit nodes and subnet routers work
when in scenarios where NAT is required.
It also updates the NATConfig to be generated from a `wgcfg.Config` as
that handles merging prefs with the netmap, so it has the required information
about whether an exit node is already configured and whether routes are accepted.
Updates tailscale/corp#8020
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Since users can run tailscaled in a variety of ways (root, non-root,
non-root with process capabilities on Linux), this check will print the
current process permissions to the log to aid in debugging.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ida93a206123f98271a0c664775d0baba98b330c7
In addition to checking the total hostname length, validate characters used in each DNS label and label length.
Updates https://github.com/tailscale/corp/issues/10012
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
* wgengine/magicsock: add envknob to send CallMeMaybe to non-existent peer
For testing older client version responses to the PeerGone packet format change.
Updates #4326
Signed-off-by: Val <valerie@tailscale.com>
* derp: remove dead sclient struct member replaceLimiter
Leftover from an previous solution to the duplicate client problem.
Updates #2751
Signed-off-by: Val <valerie@tailscale.com>
* derp, derp/derphttp, wgengine/magicsock: add new PeerGone message type Not Here
Extend the PeerGone message type by adding a reason byte. Send a
PeerGone "Not Here" message when an endpoint sends a disco message to
a peer that this server has no record of.
Fixes#4326
Signed-off-by: Val <valerie@tailscale.com>
---------
Signed-off-by: Val <valerie@tailscale.com>
We were checking against the wrong directory, instead if we
have a custom store configured just use that.
Fixes#7588Fixes#7665
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Kubernetes uses SPDY/3.1 which is incompatible with HTTP/2, disable it
in the transport and server.
Fixes#7645Fixes#7646
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This change focuses on the backend log ID, which is the mostly commonly
used in the client. Tests which don't seem to make use of the log ID
just use the zero value.
Signed-off-by: Will Norris <will@tailscale.com>
This allows disabling spread mode, which is helpful if you are manually
running derpprobe in `--once` mode against a small number of DERP
machines.
Updates https://github.com/tailscale/corp/issues/9916
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
We were not handling tags at all, pass them through as Impersonate-Group headers.
And use the FQDN for tagged nodes as Impersonate-User.
Updates #5055
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This lets a tsnet binary share a server out over Tailscale Funnel.
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
This reverts commit 6eca47b16c and fixes forward.
Previously the first ever streaming MapRequest that a client sent would also
set ReadOnly to true as it didn't have any endpoints and expected/relied on the
map poll to restart as soon as it got endpoints. However with 48f6c1eba4,
we would no longer restart MapRequests as frequently as we used to, so control
would only ever get the first streaming MapRequest which had ReadOnly=true.
Control would treat this as an uninteresting request and would not send it
any further netmaps, while the client would happily stay in the map poll forever
while litemap updates happened in parallel.
This makes it so that we never set `ReadOnly=true` when we are doing a streaming
MapRequest. This is no longer necessary either as most endpoint discovery happens
over disco anyway.
Co-authored-by: Andrew Dunham <andrew@du.nham.ca>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This change adds a ringbuffer to each magicsock endpoint that keeps a
fixed set of "changes"–debug information about what updates have been
made to that endpoint.
Additionally, this adds a LocalAPI endpoint and associated
"debug peer-status" CLI subcommand to fetch the set of changes for a given
IP or hostname.
Updates tailscale/corp#9364
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I34f726a71bddd0dfa36ec05ebafffb24f6e0516a
Add a DNS server which always responds as its own IP addresses.
Additionally add a tsnet TailscaleIPs() function to return the
IP addresses, both IPv4 and IPv6.
Updates https://github.com/tailscale/tailscale/issues/1748
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
No ListenPacket support yet, but Listen with a udp network type fit
easier into netstack's model to start.
Then added an example of using it to cmd/sniproxy with a little udp
:53 handler.
No tests in tsnet yet because we don't have support for dialing over
UDP in tsnet yet. When that's done, a new test can test both sides.
Updates #5871
Updates #1748
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We have many function pointers that we replace for the duration of test and
restore it on test completion, add method to do that.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Now that we're using rand.Shuffle in a few locations, create a generic
shuffle function and use it instead. While we're at it, move the
interleaveSlices function to the same package for use.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I0b00920e5b3eea846b6cedc30bd34d978a049fd3
The debug flag on tailscaled isn't available in the macOS App Store
build, since we don't have a tailscaled binary; move it to the
'tailscale debug' CLI that is available on all platforms instead,
accessed over LocalAPI.
Updates #7377
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I47bffe4461e036fab577c2e51e173f4003592ff7
Followup to #7177 to avoid adding extra dependencies to the CLI. We
instead declare an interface for the link monitor.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This is to address a possible DNS failure on startup. Before this
change IPv6 addresses would be listed first, and the client dialer would
fail for hosts without IPv6 connectivity.
We had two implemenetations of the kube client, merge them.
containerboot was also using a raw http.Transport, this also has
the side effect of making it use a http.Client
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Given recent changes in corp, I originally thought we could remove all of the
syso files, but then I realized that we still need them so that binaries built
purely from OSS (without going through corp) will still receive a manifest.
We can remove the arm32 one though, since we don't support 32-bit ARM on Windows.
Updates https://github.com/tailscale/corp/issues/9576
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
"Device Authorization" was recently renamed to "Device Approval"
on the control side. This change updates the k8s operator to match.
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
"Device Authorization" was recently renamed to "Device Approval"
on the control side. This change updates tsconnect to match.
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
Uses the hooks added by tailscale/go#45 to instrument the reads and
writes on the major code paths that do network I/O in the client. The
convention is to use "<package>.<type>:<label>" as the annotation for
the responsible code path.
Enabled on iOS, macOS and Android only, since mobile platforms are the
ones we're most interested in, and we are less sensitive to any
throughput degradation due to the per-I/O callback overhead (macOS is
also enabled for ease of testing during development).
For now just exposed as counters on a /v0/sockstats PeerAPI endpoint.
We also keep track of the current interface so that we can break out
the stats by interface.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
"Device Authorization" was recently renamed to "Device Approval"
on the control side. This change updates the linux cli to match.
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
The log ID types were moved to a separate package so that
code that only depend on log ID types do not need to link
in the logic for the logtail client itself.
Not all code need the logtail client.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This allows us to differentiate between the various tsnet apps that
we have like `golinks` and `k8s-operator`.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
trimmed builds don't have absolute path information in executable
metadata, which leads the runtime.Caller approach failing
mysteriously in yarn with complaints about relative package paths.
So, instead of using embedded package metadata to find paths,
expect that we're being invoked within the tailscale repo, and
locate the tsconnect directory that way.
Signed-off-by: David Anderson <danderson@tailscale.com>
This ensures that we put the kubeconfig in the correct directory from within the macOS Sandbox when
paired with tailscale/corp@3035ef7
Updates #7220
Signed-off-by: Maisem Ali <maisem@tailscale.com>
In the switch to static toolchains, we removed a legacy oddity from the
toolchain URL structure, but forgot to update printdep.
Signed-off-by: David Anderson <danderson@tailscale.com>
With #6566 we added an external mechanism for getting the default
interface, and used it on macOS and iOS (see tailscale/corp#8201).
The goal was to be able to get the default physical interface even when
using an exit node (in which case the routing table would say that the
Tailscale utun* interface is the default).
However, the external mechanism turns out to be unreliable in some
cases, e.g. when multiple cellular interfaces are present/toggled (I
have occasionally gotten my phone into a state where it reports the pdp_ip1
interface as the default, even though it can't actually route traffic).
It was observed that `ifconfig -v` on macOS reports an "effective interface"
for the Tailscale utn* interface, which seems promising. By examining
the ifconfig source code, it turns out that this is done via a
SIOCGIFDELEGATE ioctl syscall. Though this is a private API, it appears
to have been around for a long time (e.g. it's in the 10.13 xnu release
at https://opensource.apple.com/source/xnu/xnu-4570.41.2/bsd/net/if_types.h.auto.html)
and thus is unlikely to go away.
We can thus use this ioctl if the routing table says that a utun*
interface is the default, and go back to the simpler mechanism that
we had before #6566.
Updates #7184
Updates #7188
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Tailnet-owned auth keys (which all OAuth-created keys are) must include tags, since there is no user to own the registered devices.
Signed-off-by: Will Norris <will@tailscale.com>
Also removes the toolchain builds from flake.nix. For now the flake
build uses upstream Go 1.20, a followup change will switch it back to
our custom toolchain.
Updates tailscale/corp#9005
Signed-off-by: David Anderson <danderson@tailscale.com>
When we make a connection to a server, we previously would verify with
the system roots, and then fall back to verifying with our baked-in
Let's Encrypt root if the system root cert verification failed.
We now explicitly check for, and log a health error on, self-signed
certificates. Additionally, we now always verify against our baked-in
Let's Encrypt root certificate and log an error if that isn't
successful. We don't consider this a health failure, since if we ever
change our server certificate issuer in the future older non-updated
versions of Tailscale will no longer be healthy despite being able to
connect.
Updates #3198
Change-Id: I00be5ceb8afee544ee795e3c7a2815476abc4abf
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
It's since been rewritten in Swift.
#cleanup
Change-Id: I0860d681e8728697804ce565f63c5613b8b1088c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It includes xtermjs/xterm.js#4216, which improves handling of some
escape sequences. Unfortunately it's not enough to fix the issue
with `ponysay`, but it does not hurt to be up to date.
Updates #6090
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
`prober.DERP` was created in #5988 based on derpprobe. Having used it
instead of derpprobe for a few months, I think we have enough confidence
that it works and can now migrate derpprobe to use the prober framework
and get rid of code duplication.
A few notable changes in behaviour:
- results of STUN probes over IPv4 and IPv6 are now reported separately;
- TLS probing now includes OCSP verification;
- probe names in the output have changed;
- ability to send Slack notification from the prober has been removed.
Instead, the prober now exports metrics in Expvar (/debug/vars) and
Prometheus (/debug/varz) formats.
Fixes https://github.com/tailscale/corp/issues/8497
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
Makes the Wasm client more similar to the others, and allows the default
profile to be correctly picked up when restarting the client in dev
mode (where we persist the state in sessionStorage).
Also update README to reflect that Go wasm changes can be picked up
with just a reload (as of #5383)
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
There is no stable release yet, and for alpha we want people on the
unstable build while we iterate.
Updates #502
Signed-off-by: David Anderson <danderson@tailscale.com>
Update all code generation tools, and those that check for license
headers to use the new standard header.
Also update copyright statement in LICENSE file.
Fixes#6865
Signed-off-by: Will Norris <will@tailscale.com>
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
Running sync-containers in a GitHub workflow will be
simpler if we check github.Keychain, which uses the
GITHUB_TOKEN if present.
Updates https://github.com/tailscale/corp/issues/8461
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
The dependency injection functionality has been deprecated a while back
and it'll be removed in the 0.15 release of Controller Runtime. This
changeset sets the Client after creating the Manager, instead of using
InjectClient.
Signed-off-by: Vince Prignano <vince@prigna.com>
Per recent user confusion on a QNAP issue.
Change-Id: Ibda00013df793fb831f4088b40be8a04dfad17c2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Add `tailscale version --json` JSON output mode. This will be used
later for a double-opt-in (per node consent like Tailscale SSH +
control config) to let admins do remote upgrades via `tailscale
update` via a c2n call, which would then need to verify the
cmd/tailscale found on disk for running tailscale update corresponds
to the running tailscaled, refusing if anything looks amiss.
Plus JSON output modes are just nice to have, rather than parsing
unstable/fragile/obscure text formats.
Updates #6995
Updates #6907
Change-Id: I7821ab7fbea4612f4b9b7bdc1be1ad1095aca71b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
They changed a type in their SDK which meant others using the AWS APIs
in their Go programs (with newer AWS modules in their caller go.mod)
and then depending on Tailscale (for e.g. tsnet) then couldn't compile
ipn/store/awsstore.
Thanks to @thisisaaronland for bringing this up.
Fixes#7019
Change-Id: I8d2919183dabd6045a96120bb52940a9bb27193b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Create an interface and mock implementation of tailscale.LocalClient for
serve command tests.
Updates #6304Closes#6372
Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
Goal: one way for users to update Tailscale, downgrade, switch tracks,
regardless of platform (Windows, most Linux distros, macOS, Synology).
This is a start.
Updates #755, etc
Change-Id: I23466da1ba41b45f0029ca79a17f5796c2eedd92
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
UI works remains, but data is there now.
Updates #4015
Change-Id: Ib91e94718b655ad60a63596e59468f3b3b102306
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The -terminate-tls flag is for the tcp subsubcommand, not the serve
subcommand like the usage example suggests.
Signed-off-by: salman <salman@tailscale.com>
QNAP's "Force HTTPS" mode redirects even localhost HTTP to
HTTPS, but uses a self-signed certificate which fails
verification. We accommodate this by disabling checking
of the cert.
Fixes https://github.com/tailscale/tailscale/issues/6903
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
We still accept the previous TS_AUTH_KEY for backwards compatibility, but the documented option name is the spelling we use everywhere else.
Updates #6321
Signed-off-by: David Anderson <danderson@tailscale.com>
With a42a594bb3, iOS uses netstack and
hence there are no longer any platforms which use the legacy MagicDNS path. As such, we remove it.
We also normalize the limit for max in-flight DNS queries on iOS (it was 64, now its 256 as per other platforms).
It was 64 for the sake of being cautious about memory, but now we have 50Mb (iOS-15 and greater) instead of 15Mb
so we have the spare headroom.
Signed-off-by: Tom DNetto <tom@tailscale.com>
This makes `tailscale debug watch-ipn` safe to use for troubleshooting
user issues, in addition to local debugging during development.
Signed-off-by: David Anderson <danderson@tailscale.com>
The macOS client was forgetting to call netstack.Impl.SetLocalBackend.
Change the API so that it can't be started without one, eliminating this
class of bug. Then update all the callers.
Updates #6764
Change-Id: I2b3a4f31fdfd9fdbbbbfe25a42db0c505373562f
Signed-off-by: Claire Wang <claire@tailscale.com>
Co-authored-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It's long & distracting for how low value it is.
Fixes#6766
Change-Id: I51364f25c0088d9e63deb9f692ba44031f12251b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In some configurations, user explicitly do not want to store
tailscale state in k8s secrets, because doing that leads to
some annoying permission issues with sidecar containers.
With this change, TS_KUBE_SECRET="" and TS_STATE_DIR=/foo
will force storage to file when running in kubernetes.
Fixes#6704.
Signed-off-by: David Anderson <danderson@tailscale.com>
The operator creates a fair bit of internal cluster state to manage proxying,
dumping it all in the default namespace is handy for development but rude
for production.
Updates #502
Signed-off-by: David Anderson <danderson@tailscale.com>
We used to need to do timed requeues in a few places in the reconcile logic,
and the easiest way to do that was to plumb reconcile.Result return values
around. But now we're purely event-driven, so the only thing we care about
is whether or not an error occurred.
Incidentally also fix a very minor bug where headless services would get
completely ignored, rather than reconciled into the correct state. This
shouldn't matter in practice because you can't transition from a headful
to a headless service without a deletion, but for consistency let's avoid
having a path that takes no definite action if a service of interest does
exist.
Updates #502.
Signed-off-by: David Anderson <danderson@tailscale.com>
Previously, we had to do blind timed requeues while waiting for
the tailscale hostname, because we looked up the hostname through
the API. But now the proxy container image writes back its hostname
to the k8s secret, so we get an event-triggered reconcile automatically
when the time is right.
Updates #502
Signed-off-by: David Anderson <danderson@tailscale.com>
As is convention in the k8s world, use zap for structured logging. For
development, OPERATOR_LOGGING=dev switches to a more human-readable output
than JSON.
Updates #502
Signed-off-by: David Anderson <danderson@tailscale.com>
Our reconcile loop gets triggered again when the StatefulSet object
finally disappears (in addition to when its deletion starts, as indicated
by DeletionTimestamp != 0). So, we don't need to queue additional
reconciliations to proceed with the remainder of the cleanup, that
happens organically.
Signed-off-by: David Anderson <danderson@tailscale.com>
Tests cover configuring a proxy through an annotation rather than a
LoadBalancerClass, and converting between those two modes at runtime.
Updates #502.
Signed-off-by: David Anderson <danderson@tailscale.com>
For other test cases, the operator is going to produce similar generated
objects in several codepaths, and those objects are large. Move them out
to helpers so that the main test code stays a bit more intelligible.
The top-level Service that we start and end with remains in the main test
body, because its shape at the start and end is one of the main things that
varies a lot between test cases.
Updates #502.
Signed-off-by: David Anderson <danderson@tailscale.com>
The test verifies one of the successful reconcile paths, where
a client requests an exposed service via a LoadBalancer class.
Updates #502.
Signed-off-by: David Anderson <danderson@tailscale.com>
Also introduces an intermediary interface for the tailscale client, in
preparation for operator tests that fake out the Tailscale API interaction.
Updates #502.
Signed-off-by: David Anderson <danderson@tailscale.com>
This was initially developed in a separate repo, but for build/release
reasons and because go module management limits the damage of importing
k8s things now, moving it into this repo.
At time of commit, the operator enables exposing services over tailscale,
with the 'tailscale' loadBalancerClass. It also currently requires an
unreleased feature to access the Tailscale API, so is not usable yet.
Updates #502.
Signed-off-by: David Anderson <danderson@tailscale.com>
We've been doing a hard kill of the subprocess, which is only safe as long as
both the cli and gui are not running and the subprocess has had the opportunity
to clean up DNS settings etc. If unattended mode is turned on, this is definitely
unsafe.
I changed babysitProc to close the subprocess's stdin to make it shut down, and
then I plumbed a cancel function into the stdin reader on the subprocess side.
Fixes https://github.com/tailscale/corp/issues/5621
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
This is temporary while we work to upstream performance work in
https://github.com/WireGuard/wireguard-go/pull/64. A replace directive
is less ideal as it breaks dependent code without duplication of the
directive.
Signed-off-by: Jordan Whited <jordan@tailscale.com>
This commit updates the wireguard-go dependency and implements the
necessary changes to the tun.Device and conn.Bind implementations to
support passing vectors of packets in tailscaled. This significantly
improves throughput performance on Linux.
Updates #414
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Signed-off-by: James Tucker <james@tailscale.com>
Co-authored-by: James Tucker <james@tailscale.com>
This avoids the issue in the common case where the socket path is the
default path, avoiding the immediate need for a Windows shell quote
implementation.
Updates #6639
Signed-off-by: James Tucker <james@tailscale.com>
Fixes#6400
open up GETs for localapi serve-config to allow read-only access to
ServeConfig
`tailscale status` will include "Funnel on" status when Funnel is
configured. Prints nothing if Funnel is not running.
Example:
$ tailscale status
<nodes redacted>
# Funnel on:
# - https://node-name.corp.ts.net
# - https://node-name.corp.ts.net:8443
# - tcp://node-name.corp.ts.net:10000
Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
We still have to shell out to `tailscale up` because the container image's
API includes "arbitrary flags to tailscale up", unfortunately. But this
should still speed up startup a little, and also enables k8s-bound containers
to update their device information as new netmap updates come in.
Fixes#6657
Signed-off-by: David Anderson <danderson@tailscale.com>
* Do not print the status at the end of a successful operation
* Ensure the key of the current node is actually trusted to make these changes
Signed-off-by: Tom DNetto <tom@tailscale.com>
WinTun is installed lazily by tailscaled while it is running as LocalSystem.
Based upon what we're seeing in bug reports and support requests, removing
WinTun as a lesser user may fail under certain Windows versions, even when that
user is an Administrator.
By adding a user-defined command code to tailscaled, we can ask the service to
do the removal on our behalf while it is still running as LocalSystem.
* The uninstall code is basically the same as it is in corp;
* The command code will be sent as a service control request and is protected by
the SERVICE_USER_DEFINED_CONTROL access right, which requires Administrator.
I'll be adding follow-up patches in corp to engage this functionality.
Updates https://github.com/tailscale/tailscale/issues/6433
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
This handles the case where the inner *os.PathError is wrapped in
another error type, and additionally will redact errors of type
*os.LinkError. Finally, add tests to verify that redaction works.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ie83424ff6c85cdb29fb48b641330c495107aab7c
x/exp/slices now has ContainsFunc (golang/go#53983) so we can delete
our versions.
Change-Id: I5157a403bfc1b30e243bf31c8b611da25e995078
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
renamed from `useNetstack` to `onlyNetstack` which is 1 letter more but
more descriptive because we always have netstack enabled and `useNetstack`
doesn't convey what it is supposed to be used for. e.g. we always use
netstack for Tailscale SSH.
Also renamed shouldWrapNetstack to handleSubnetsInNetstack as it was only used
to configure subnet routing via netstack.
Updates tailscale/corp#8020
Signed-off-by: Maisem Ali <maisem@tailscale.com>
To simplify clients getting the initial state when they subscribe.
Change-Id: I2490a5ab2411253717c74265a46a98012b80db82
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
When running `tailscale web` as a standalone process,
it was necessary to send auth requests to QTS using
localhost to avoid hitting the proxy recursively.
However running `tailscale web` as a process means it is
consuming RAM all the time even when it isn't actively
doing anything.
After switching back to the `tailscale web` CGI mode, we
don't need to specifically use localhost for QNAP auth.
This reverts commit e0cadc5496.
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
This reverts commit f1130421f0.
It was submitted with failing tests (go generate checks)
Requires a lot of API changes to fix so rolling back instead of
forward.
Change-Id: I024e8885c0ed44675d3028a662f386dda811f2ad
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This adds an envknob to make testing async startup more reproducible.
We want the Windows GUI to behave well when wintun is not (or it's
doing its initial slow driver installation), but during testing it's often
too fast to see that it's working. This lets it be slowed down.
Updates #6522
Change-Id: I6ae19f46e270ea679cbaea32a53888efcf2943a7
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Previously, tstun.Wrapper and magicsock.Conn managed their
own statistics data structure and relied on an external call to
Extract to extract (and reset) the statistics.
This makes it difficult to ensure a maximum size on the statistics
as the caller has no introspection into whether the number
of unique connections is getting too large.
Invert the control flow such that a *connstats.Statistics
is registered with tstun.Wrapper and magicsock.Conn.
Methods on non-nil *connstats.Statistics are called for every packet.
This allows the implementation of connstats.Statistics (in the future)
to better control when it needs to flush to ensure
bounds on maximum sizes.
The value registered into tstun.Wrapper and magicsock.Conn could
be an interface, but that has two performance detriments:
1. Method calls on interface values are more expensive since
they must go through a virtual method dispatch.
2. The implementation would need a sync.Mutex to protect the
statistics value instead of using an atomic.Pointer.
Given that methods on constats.Statistics are called for every packet,
we want reduce the CPU cost on this hot path.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Many packages reference the logtail ID types,
but unfortunately pull in the transitive dependencies of logtail.
Fix this problem by putting the log ID types in its own package
with minimal dependencies.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
I added util/winutil/LookupPseudoUser, which essentially consists of the bits
that I am in the process of adding to Go's standard library.
We check the provided SID for "S-1-5-x" where 17 <= x <= 20 (which are the
known pseudo-users) and then manually populate a os/user.User struct with
the correct information.
Fixes https://github.com/tailscale/tailscale/issues/869
Fixes https://github.com/tailscale/tailscale/issues/2894
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
tailscaled on Windows had two entirely separate start-up paths for running
as a service vs in the foreground. It's been causing problems for ages.
This unifies the two paths, making them be the same as the path used
for every other platform.
Also, it uses the new async LocalBackend support in ipnserver.Server
so the Server can start serving HTTP immediately, even if tun takes
awhile to come up.
Updates #6535
Change-Id: Icc8c4f96d4887b54a024d7ac15ad11096b5a58cf
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We use this pattern in a number of places (in this repo and elsewhere)
and I was about to add a fourth to this repo which was crossing the line.
Add this type instead so they're all the same.
Also, we have another Set type (SliceSet, which tracks its keys in
order) in another repo we can move to this package later.
Change-Id: Ibbdcdba5443fae9b6956f63990bdb9e9443cefa9
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This is step 1 of de-special-casing of Windows and letting the
LocalAPI HTTP server start serving immediately, even while the rest of
the world (notably the Engine and its TUN device) are being created,
which can take a few to dozens of seconds on Windows.
With this change, the ipnserver.New function changes to not take an
Engine and to return immediately, not returning an error, and let its
Run run immediately. If its ServeHTTP is called when it doesn't yet
have a LocalBackend, it returns an error. A TODO in there shows where
a future handler will serve status before an engine is available.
Future changes will:
* delete a bunch of tailscaled_windows.go code and use this new API
* add the ipnserver.Server ServerHTTP handler to await the engine
being available
* use that handler in the Windows GUI client
Updates #6522
Change-Id: Iae94e68c235e850b112a72ea24ad0e0959b568ee
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Still show original, but show de-punycode version in parens,
similar to how we show DNS-less hostnames.
Change-Id: I7e57da5e4029c5b49e8cd3014c350eddd2b3c338
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We'll eventually remove it entirely, but for now move get it out of ipnserver
where it's distracting and move it to its sole caller.
Updates #6522
Change-Id: I9c6f6a91bf9a8e3c5ea997952b7c08c81723d447
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It's only used by Windows. No need for it to be in ipn/ipnserver,
which we're trying to trim down.
Change-Id: Idf923ac8b6cdae8b5338ec26c16fb8b5ea548071
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Unused in this repo as of the earlier #6450 (300aba61a6)
and unused in the Windows GUI as of tailscale/corp#8065.
With this ipn.BackendServer is no longer used and could also be
removed from this repo. The macOS and iOS clients still temporarily
depend on it, but I can move it to that repo instead while and let its
migration proceed on its own schedule while we clean this repo up.
Updates #6417
Updates tailscale/corp#8051
Change-Id: Ie13f82af3eb9f96b3a21c56cdda51be31ddebdcf
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Follow-up to #6467 and #6506.
LocalBackend knows the server-mode state, so move more auth checking
there, removing some bookkeeping from ipnserver.Server.
Updates #6417
Updates tailscale/corp#8051
Change-Id: Ic5d14a077bf0dccc92a3621bd2646bab2cc5b837
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
There are three specific requirements for Funnel to work:
1) They must accept an invite.
2) They must enable HTTPS.
3) The "funnel" node attribute must be appropriately set up in the ACLs.
Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
This patch removes the crappy, half-backed COM initialization used by `go-ole`
and replaces that with the `StartRuntime` function from `wingoes`, a library I
have started which, among other things, initializes COM properly.
In particular, we should always be initializing COM to use the multithreaded
apartment. Every single OS thread in the process becomes implicitly initialized
as part of the MTA, so we do not need to concern ourselves as to whether or not
any particular OS thread has initialized COM. Furthermore, we no longer need to
lock the OS thread when calling methods on COM interfaces.
Single-threaded apartments are designed solely for working with Win32 threads
that have a message pump; any other use of the STA is invalid.
Fixes https://github.com/tailscale/tailscale/issues/3137
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
Centralize the fake GOOS stuff, start to use it more. To be used more
in the future.
Change-Id: Iabacfbeaf5fca0b53bf4d5dbcdc0367f05a205f9
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We're trying to gut 90% of the ipnserver package. A lot will get
deleted, some will move to LocalBackend, and a lot is being moved into
this new ipn/ipnauth package which will be leaf-y and testable.
This is a baby step towards moving some stuff to ipnauth.
Update #6417
Updates tailscale/corp#8051
Change-Id: I28bc2126764f46597d92a2d72565009dc6927ee0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit implements `tailscale lock log [--limit N]`, which displays an ordered list
of changes to network-lock state in a manner familiar to `git log`.
Signed-off-by: Tom DNetto <tom@tailscale.com>
This uses a go:generate statement to create a bunch of .syso files that
contain a Windows resource file. We check these in since they're less
than 1KiB each, and are only included on Windows.
Fixes#6429
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I0512c3c0b2ab9d8d8509cf2037b88b81affcb81f
Current behavior is broken. tailscale serve text / "" returns no error
and shows up in tailscale serve status but requests return a 500
"empty handler".
Adds an error if the user passes in an empty string for the text
handler.
Closes#6405
Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
This sets the "com.apple.quarantine" flag on macOS, and the
"Zone.Identifier" alternate data stream on Windows.
Change-Id: If14f805467b0e2963067937d7f34e08ba1d1fa85
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
This moves the NetworkLock key from a dedicated StateKey to be part of the persist.Persist struct.
This struct is stored as part for ipn.Prefs and is also the place where we store the NodeKey.
It also moves the ChonkDir from "/tka" to "/tka-profile/<profile-id>". The rename was intentional
to be able to delete the "/tka" dir if it exists.
This means that we will have a unique key per profile, and a unique directory per profile.
Note: `tailscale logout` will delete the entire profile, including any keys. It currently does not
delete the ChonkDir.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
QNAP 5.x works much better if we let Apache proxy
tailscale web, which means the URLs can no longer
be relative since apache sends us an internal
URL. Access QNAP authentication via
http://localhost:8080/ as documented in
https://download.qnap.com/dev/API_QNAP_QTS_Authentication.pdf
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
The key changed, but also we have a localapi method to set it anyway, so
use that.
Updates tailscale/corp#7515
Change-Id: Ia08ea2509f0bdd9b59e4c5de53aacf9a7d7eda36
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Run an inotify goroutine and watch if another program takes over
/etc/inotify.conf. Log if so.
For now this only logs. In the future I want to wire it up into the
health system to warn (visible in "tailscale status", etc) about the
situation, with a short URL to more info about how you should really
be using systemd-resolved if you want programs to not fight over your
DNS files on Linux.
Updates #4254 etc etc
Change-Id: I86ad9125717d266d0e3822d4d847d88da6a0daaa
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Noticed this while debugging something else, we would reset all routes if
either `--advertise-exit-node` or `--advertise-routes` were set. This handles
correctly updating them.
Also added tests.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
The serve CLI doesn't exist yet, but we want nice tests for it when it
does exist.
Updates tailscale/corp#7515
Change-Id: Ib4c73d606242c4228f87410bbfd29bec52ca6c60
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
(I should've done this to start with.)
Updates tailscale/corp#7515
Change-Id: I7fb88cf95772790fd415ecf28fc52bde95507641
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Example output:
# Health check:
# - Some peers are advertising routes but --accept-routes is false
Also, move "tailscale status" health checks to the bottom, where they
won't be lost in large netmaps.
Updates #2053
Updates #6266
Change-Id: I5ae76a0cd69a452ce70063875cd7d974bfeb8f1a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If the --key-file output filename ends in ".pfx" or ".p12", use pkcs12
format.
This might not be working entirely correctly yet but might be enough for
others to help out or experiment.
Updates #2928
Updates #5011
Change-Id: I62eb0eeaa293b9fd5e27b97b9bc476c23dd27cf6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Map is a concurrent safe map that is a trivial wrapper
over a Go map and a sync.RWMutex.
It is optimized for use-cases where the entries change often,
which is the opposite use-case of what sync.Map is optimized for.
The API is patterned off of sync.Map, but made generic.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>