Commit Graph

648 Commits (a1b8d703d62d1419a2dcf79c9c1aa955fec101ff)

Author SHA1 Message Date
Andrew Dunham 5ba2543828 ipn/ipnlocal: print warning about DNS servers in bugreport --diagnose
If the user passes the --diagnose flag, print a warning if any of the
default or fallback DNS resolvers are Tailscale IPs. This can interfere
with the ability to connect to the controlplane, and is typically
something to pay attention to if there's a connectivity issue.

Change-Id: Ib14bf6228c037877fbdcd22b069212b1a4b2c456
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
2 years ago
Brad Fitzpatrick b1248442c3 all: update to Go 1.20, use strings.CutPrefix/Suffix instead of our fork
Updates #7123
Updates #5309

Change-Id: I90bcd87a2fb85a91834a0dd4be6e03db08438672
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Andrew Dunham d1146dc701 ipn/ipnlocal: rate-limit diagnose logs in bugreport
We can log too quickly for logtail to catch up, even when we opt out of
log rate-limiting. When the user passes the --diagnose flag to
bugreport, we use a token bucket to control how many logs per second are
printed and sleep until we're able to write more.

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: If27672d66b621b589280bd0fe228de367ffcbd8f
2 years ago
Maisem Ali 04b57a371e ipn/ipnlocal: drop not required StateKey parameter
This is #cleanup now that #7121 is merged.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Mihai Parparita 4973956419 ipn/ipnlocal: add /reset-auth LocalAPI endpoint
The iOS has a command to reset the persisted state of the app, but it
was doing its own direct keychain manipulation. This proved to be
brittle (since we changed how preferences are stored with #6022), so
we instead add a LocalAPI endpoint to do do this, which can be updated
in tandem.

This clears the same state as the iOS implementation (tailscale/corp#3186),
that is the machine key and preferences (which includes the node key).
Notably this does not clear the logtail ID, so that logs from the device
still end up in the same place.

Updates tailscale/corp#8923

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Will Norris 71029cea2d all: update copyright and license headers
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>
2 years ago
Andrew Dunham 2703d6916f net/netns: add functionality to bind outgoing sockets based on route table
When turned on via environment variable (off by default), this will use
the BSD routing APIs to query what interface index a socket should be
bound to, rather than binding to the default interface in all cases.

Updates #5719
Updates #5940

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ib4c919471f377b7a08cd3413f8e8caacb29fee0b
2 years ago
Andrew Dunham 44d73ce932 ipn/ipnlocal, net/dnscache: allow configuring dnscache logging via capability
This allows users to temporarily enable/disable dnscache logging via a
new node capability, to aid in debugging strange connectivity issues.

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I46cf2596a8ae4c1913880a78d0033f8b668edc08
2 years ago
Brad Fitzpatrick 6e5faff51e ipn/ipnlocal: add health warning for Tailscale SSH + SELinux
Updates #4908

Change-Id: If46be5045b13dd5c3068c334642f89b5917ec861
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Andrew Dunham 140b9aad5c ipn/ipnlocal: fire expiry timer when the current node expires
The current node isn't in NetMap.Peers, so without this we would not
have fired this timer on self expiry.

Updates #6932

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Id57f96985397e372f9226802d63b42ff92c95093
2 years ago
Brad Fitzpatrick 06fff461dc ipn/ipnstate: add PeerStatus.KeyExpiry for tailscale status --json
Fixes #6712

Change-Id: I817cd5342fac8a956fcefda2d63158fa488f3395
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick b6aa1c1f22 envknob, hostinfo, ipn/ipnlocal: add start of opt-in remote update support
Updates #6907

Change-Id: I85db4f6f831dd5ff7a9ef4bfa25902607e0c1558
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
shayne 4471e403aa
ipn/ipnlocal: [serve] listen on all-interfaces for macOS sandboxed (#6771)
On macOS (AppStore and macsys), we need to bind to ""/all-interfaces
due to the network sandbox. Ideally we would only bind to the
Tailscale interface, but macOS errors out if we try to
to listen on privileged ports binding only to a specific
interface.

We also implement the lc.Control hook, same as we do for
peerapi. It doesn't solve our problem but it's better that
we do and would likely be required when Apple gets around to
fixing per-interface priviliged port binding.

Fixes: #6364

Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
2 years ago
Brad Fitzpatrick 6edf357b96 all: start groundwork for using capver for localapi & peerapi
Updates #7015

Change-Id: I3d4c11b42a727a62eaac3262a879f29bb4ce82dd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
salman eec734a578 ipn/{ipnlocal,localapi}: ensure watcher is installed before /watch-ipn-bus/ responds with 200
This change delays the first flush in the /watch-ipn-bus/ handler
until after the watcher has been successfully installed on the IPN
bus. It does this by adding a new onWatchAdded callback to
LocalBackend.WatchNotifications().

Without this, the endpoint returns a 200 almost immediatly, and
only then installs a watcher for IPN events.  This means there's a
small window where events could be missed by clients after calling
WatchIPNBus().

Fixes tailscale/corp#8594.

Signed-off-by: salman <salman@tailscale.com>
2 years ago
Andrew Dunham 3a018e51bb ipn/ipnlocal: move handling of expired nodes to LocalBackend
In order to be able to synthesize a new NetMap when a node expires, have
LocalBackend start a timer when receiving a new NetMap that fires
slightly after the next node expires. Additionally, move the logic that
updates expired nodes into LocalBackend so it runs on every netmap
(whether received from controlclient or self-triggered).

Updates #6932

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I833390e16ad188983eac29eb34cc7574f555f2f3
2 years ago
Mihai Parparita 67f82e62a1 ipn/ipnlocal: add Expired to PeerStatus
Needed for clients that get information via the /v0/status LocalAPI
endpoint (e.g. to not offer expired exit nodes as options).

Updates tailscale/corp#8702

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Andrew Dunham 11ce5b7e57 ipn/ipnlocal, wgengine/magicsock: check Expired bool on Node; print error in Ping
Change-Id: Ic5f533f175a6e1bb73d4957d8c3f970add42e82e
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
2 years ago
Brad Fitzpatrick 61dfbc0a6e cmd/tailscale/cli: plumb TUN mode into tailscale web template
UI works remains, but data is there now.

Updates #4015

Change-Id: Ib91e94718b655ad60a63596e59468f3b3b102306
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
James Tucker 2afa1672ac ipn/ipnlocal: disallow unsigned peers from WoL
Unsigned peers should not be allowed to generate Wake-on-Lan packets,
only access Funnel.

Updates #6934
Updates #7515
Updates #6475

Signed-off-by: James Tucker <james@tailscale.com>
2 years ago
Brad Fitzpatrick 1116602d4c ssh/tailssh: add OpenBSD support for Tailscale SSH
And bump go.mod for https://github.com/u-root/u-root/pull/2593

Change-Id: I36ec94c5b2b76d671cb739f1e9a1a43ca1d9d1b1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 69c0b7e712 ipn/ipnlocal: add c2n handler to flush logtail for support debugging
Updates tailscale/corp#8564

Change-Id: I0c619d4007069f90cffd319fba66bd034d63e84d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Tom DNetto 0088c5ddc0 health,ipn/ipnlocal: report the node being locked out as a health issue
Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Tom DNetto 907f85cd67 cmd/tailscale,tka: make KeyID return an error instead of panicking
Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Kristoffer Dalby c4e262a0fc
ipn/profiles: set default prefs based on Windows registry (#6803)
Co-authored-by: Maisem Ali maisem@tailscale.com
2 years ago
David Anderson 91e64ca74f cmd/tailscale/cli: redact private key in debug netmap output by default
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>
2 years ago
Anton Tolchanov 82b9689e25
ipn/ipnlocal: maintain a proxy handler per backend (#6804)
By default, `http.Transport` keeps idle connections open hoping to re-use them in the future. Combined with a separate transport per request in HTTP proxy this results in idle connection leak.

Fixes #6773
2 years ago
Brad Fitzpatrick 0f604923d3 ipn/ipnlocal: fix StatusWithoutPeers not populating parts of Status
Fixes #4311

Change-Id: Iaae0615148fa7154f4ef8f66b455e3a6c2fa9df3
Co-authored-by: Claire Wang <claire@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Joe Tsai bd2995c14b
ipn/ipnlocal: simplify redactErr (#6716)
Use multierr.Range to iterate through an error tree
instead of multiple invocations of errors.As.
This scales better as we add more Go error types to the switch.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2 years ago
Mihai Parparita 47002d93a3 ipn/ipnlocal: add a few metrics for PeerAPI and LocalAPI
Mainly motivated by wanting to know how much Taildrop is used, but
also useful when tracking down how many invalid requests are
generated.

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
salman 2d271f3bd1 ipn/ipnlocal: disallow exit nodes from using exit nodes
Nodes which have both -advertise-exit-node and -exit-node in prefs
should continue have them until the next invocation of `tailscale up`.

Updates #3569.

Signed-off-by: salman <salman@tailscale.com>
2 years ago
Tom DNetto 55e0512a05 ipn/ipnlocal,cmd/tailscale: minor improvements to lock modify command
* 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>
2 years ago
Andrew Dunham a887ca7efe ipn/ipnlocal: improve redactErr to handle more cases
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
2 years ago
Brad Fitzpatrick 1598cd0361 net/tsaddr: remove ContainsFunc helpers (they're now in x/exp/slices)
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>
2 years ago
Tom DNetto 9c773af04c ipn/ipnlocal: fix use of stale profile while processing netmap
Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Maisem Ali 86b6ff61e6 ipn/ipnlocal: fix Prefs access without mu being held
Noticed while working on a different fix.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali cdb924f87b ipn/ipnlocal: sanitize prefs in more notify code paths
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 57124e2126 ipn/localapi: add debug (root-required) access to inject debug Notify
For testing of Windows GUI client.

Updates #6480

Change-Id: I42f7526d95723e14bed7085fb759e371b43aa9da
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick e1d7d072a3 ipn/ipnlocal: set Notify.Version on initial Notifies
Missed when added recently in 8dd1418774

Change-Id: Id682640a54c3717afe084edaf69258ad23031b6c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Tom DNetto 74c1f632f6 types/key,cmd/tailscale/cli: support tlpub prefix for tailnet-lock keys
Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Brad Fitzpatrick 8dd1418774 ipn{,/ipnlocal}: add ipn.NotifyInitial* flags to WatchIPNBus
To simplify clients getting the initial state when they subscribe.

Change-Id: I2490a5ab2411253717c74265a46a98012b80db82
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick a277eb4dcf ipn/ipnlocal: add missing context cancel
If user's fn returned false and never canceled their ctx, we never
stopped the NotifyWatchEngineUpdates goroutine.

This was introduced recently (this cycle).

Change-Id: I3453966ac71e00727296ddd237ef845782f4e52e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Mihai Parparita 978d6af91a ipn/ipnlocal: tweak error handling in interfaces PeerAPI debug endpoint
We were writing the error when getting the default interface before
setting the content type, so we'd get HTML treated as plain text.

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Brad Fitzpatrick 5bdca747b7 ipn/ipnlocal: fix netstack peerapi crash over IPv6
The peerapi IPv6 listener has a nil listener.
But we didn't need the listener's address anyway, so don't
try to use it.

Change-Id: I8e8a1a895046d129a3683973e732d9bed82f3b02
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Tom DNetto f1ab11e961 ipn/ipnlocal,tailcfg: introduce capability to gate TKA init paths
Previously, `TAILSCALE_USE_WIP_CODE` was needed to hit a bunch of the TKA paths. With
this change:

 - Enablement codepaths (NetworkLockInit) and initialization codepaths (tkaBootstrapFromGenesisLocked via tkaSyncIfNeeded)
   require either the WIP envknob or CapabilityTailnetLockAlpha.
 - Normal operation codepaths (tkaSyncIfNeeded, tkaFilterNetmapLocked) require TKA to be initialized, or either-or the
   envknob / capability.
 - Auxillary commands (ie: changing tka keys) require TKA to be initialized.

The end result is that it shouldn't be possible to initialize TKA (or subsequently use any of its features) without being
sent the capability or setting the envknob on tailscaled yourself.

I've also pulled out a bunch of unnecessary checks for CanSupportNetworkLock().

Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Tom DNetto 9a80b8fb10 cmd/tailscale,ipn: surface TKA-filtered peers in lock status command
Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Maisem Ali 82ad585b5b ipn/ipnlocal: account for ControlURL when merging profiles
We merge/dedupe profiles based on UserID and NodeID, however we were not accounting for ControlURLs.

Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Tom DNetto 45042a76cd cmd/tailscale,ipn: store disallowed TKA's in prefs, lock local-disable
Take 2 of https://github.com/tailscale/tailscale/pull/6546

Builds on https://github.com/tailscale/tailscale/pull/6560

Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Tom DNetto c4980f33f7 ipn,types/persist: add DisallowedTKAStateIDs, refactor as view type
Supercedes https://github.com/tailscale/tailscale/pull/6557, precursor to trying https://github.com/tailscale/tailscale/pull/6546 again

Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Brad Fitzpatrick 6d012547b6 ipn/ipnlocal: use double dash flag style
The Go style weirds people out so we try to stick to the more
well-known double hyphen style in docs.

Change-Id: Iad6db5c82cda37f6b7687eed7ecd9276f8fd94d6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 390d1bb871 Revert "ipn,types/persist: store disallowed TKA's in prefs, lock local-disable"
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>
2 years ago
Tom DNetto f1130421f0 ipn,types/persist: store disallowed TKA's in prefs, lock local-disable
Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Aaron Klotz 659e7837c6 health, ipn/ipnlocal: when -no-logs-no-support is enabled, deny access to tailnets that have network logging enabled
We want users to have the freedom to start tailscaled with `-no-logs-no-support`,
but that is obviously in direct conflict with tailnets that have network logging
enabled.

When we detect that condition, we record the issue in health, notify the client,
set WantRunning=false, and bail.

We clear the item in health when a profile switch occurs, since it is a
per-tailnet condition that should not propagate across profiles.

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2 years ago
Maisem Ali ad41cbd9d5 ipn/ipnlocal: sanitize prefs before sending over IPN Bus
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 06c4c47d46 ipn: remove unused Backend interface
Only the macOS/iOS clients care about it still, so we'll move it
to their repo.

But keep a test that makes sure that LocalBackend continues to
implement it so we get an early warning sign before we break
macOS/iOS.

Change-Id: I56392b740fe55b4d28468b77124c821b5c46c22b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick ea25ef8236 util/set: add new set package for SetHandle type
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>
2 years ago
Tom DNetto 5c8d2fa695 cmd/tailscale,ipn: improve UX of lock init command, cosmetic changes
Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Brad Fitzpatrick 8049053f86 ipn/*: make new WindowsUserID type to consolidate docs
The "userID is empty everywhere but Windows" docs on lots of places
but not everywhere while using just a string type was getting
confusing. This makes a new type to wrap up those rules, however
weird/historical they might be.

Change-Id: I142e85a8e38760988d6c0c91d0efecedade81b9b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 5676d201d6 ipn: add a WatchIPNBus option bit to subscribe to EngineStatus changes
So GUI clients don't need to poll for it.

We still poll internally (for now!) but that's still cheaper. And will
get much cheaper later, without having to modify clients once they
start sending this bit.

Change-Id: I36647b701c8d1fe197677e5eb76f6894e8ff79f7
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 699b39dec1 ipn/ipnlocal: drop LocalBackend.inServerMode
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali c258015165 ipn/ipnlocal,ipnserver: rename {,Set}CurrentUser to {,Set}CurrentUserID
Address comments from https://github.com/tailscale/tailscale/pull/6506#discussion_r1032454064

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 0a842f353c ipn/ipnserver: move more connection acceptance logic to LocalBackend
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>
2 years ago
Brad Fitzpatrick 5ea7c7d603 ipn/{ipnlocal,ipnserver}: add some comments
Change-Id: Ieb5917edaf572342b755caa458693512c7aece81
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali d321b0ea4f ipn/ipnlocal: add docs to LocalBackend.SetCurrentUserID
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick b68d008fee envknob: add CanTaildrop (TS_DISABLE_TAILDROP) to disable taildrop on device
This matches CanSSHD (TS_DISABLE_SSH_SERVER) for administratively
disabling the code on a node, regardless of local or server configs.

This can be configured in /etc/default/tailscaled on Linux,
%ProgramData%\Tailscale\tailscaled-env.txt on Windows,
or /etc/tailscale/tailscaled-env.txt on Synology. (see getPlatformEnvFile)

Also delete some dead code and tidy up some docs.

Change-Id: I79a87c03e33209619466ea8aeb0f6651afcb8789
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 20b27df4d0 tailcfg, ipn, controlclient: add MapResponse.ClientVersion, plumb to IPN bus
Updates #6480

Change-Id: I6321071425cd091148d8140d1eb24dd536bb7984
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 4d3713f631 envknob: add GOOS func
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>
2 years ago
Brad Fitzpatrick 6e6f27dd21 ipn/ipnlocal: lock down unsigned peers more
Apparently there's no tracking bug?

Updates tailscale/corp#7515 for ingress/funnel at least.

Change-Id: I03bc54fdc1f53f9832ab8b51475b2d676c38d897
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 3a5d02cb31 ipn/ipnlocal: update comment about using FallbackResolvers for exit nodes
While reading the DNS code noticed that we were still using FallbackResolvers
in this code path but the comment was out of date.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 300aba61a6 ipn, cmd/tailscale/cli: add LocalAPI IPN bus watch, Start, convert CLI
Updates #6417
Updates tailscale/corp#8051

Change-Id: I1ca360730c45ffaa0261d8422877304277fc5625
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali d4f6efa1df ipn/ipnlocal: handle case when selected profile is deleted
Profile keys are not deleted but are instead set to `nil` which results
in getting a nil error and we were not handling that correctly.

Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Tom DNetto b45b948776 ipn/ipnlocal: call initTKALocked on backend start
Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Tom DNetto aeb80bf8cb ipn/ipnlocal,tka: generate a nonce for each TKA
Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Tom DNetto 6708f9a93f cmd/tailscale,ipn: implement lock log command
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>
2 years ago
Tom DNetto ed1fae6c73 ipn/ipnlocal: always tx TKA sync after enablement
By always firing off a sync after enablement, the control plane should know the node's TKA head
at all times.

Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Brad Fitzpatrick 0f7da5c7dc ipn{,/ipnlocal}, client/tailscale: move Taildrop recv notifications to LocalAPI HTTP method
Updates #6417

Change-Id: Iec544c477a0e5e9f1c6bf23555afec06255e2e22
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 8d84178884 ipn/ipnlocal: stop storing serverURL in LocalBackend
It's only read in a couple of places and we can read from Prefs directly.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali aeac4bc8e2 ipn/ipnlocal: account for currentUserID when iterating over knownProfiles
We were not checking the currentUserID in all code paths that looped over
knownProfiles. This only impacted multi-user Windows setups.

Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 18c7c3981a ipn/ipnlocal: call checkPrefs in Start too
We were not calling checkPrefs on `opts.*Prefs` in (*LocalBackend).Start().

Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 0480a925c1 ipn/ipnlocal: send Content-Security-Policy, etc to peerapi browser requests
Updates tailscale/corp#7948

Change-Id: Ie70e0d042478338a37b7789ac63225193e47a524
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali b94b91c168 cmd/tailscale/cli: add ability to set short names for profiles
This adds a `--nickname` flag to `tailscale login|set`.

Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 575fd5f22b ipn: add ability to name profiles
Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Mihai Parparita 33520920c3 all: use strs.CutPrefix and strs.CutSuffix more
Updates places where we use HasPrefix + TrimPrefix to use the combined
function.

Updates #5309

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Brad Fitzpatrick 039ea51ca6 ipn/ipnlocal: add health warning for unstable builds
Like the macOS About dialog.

Change-Id: Ic27f091e66e29d5eebe4e195eda97ed331d748fd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick a26f23d949 ipn/ipnlocal: actually fill out PeerAPIURLs in PeerStatus
The earlier 5f6d63936f was not complete.

Updates tailscale/corp#7515

Change-Id: I35efca51d1584c48ef6834a7d29cd42d7c943628
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali f1ad26f694 ipn/ipnlocal: strip NetworkLockKey from Prefs
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali dd50dcd067 ipn/ipnlocal: handle untagging nodes better
We would end up with duplicate profiles for the node as the UserID
would have chnaged. In order to correctly deduplicate profiles, we
need to look at both the UserID and the NodeID. A single machine can
only ever have 1 profile per NodeID and 1 profile per UserID.

Note: UserID of a Node can change when the node is tagged/untagged,
and the NodeID of a device can change when the node is deleted so we
need to check for both.

Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
shayne a97369f097
cmd/tailscale/cli: flesh out serve CLI and tests (#6304)
Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
2 years ago
Maisem Ali 5f6d63936f ipn/ipnlocal: fill out PeerAPIURLs in PeerStatus
Updates tailscale/corp#7515

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 1de64e89cd ipn/ipnlocal: set Hostinfo.WireIngress when ingress enabled
Optimization for control.

Updates tailscale/corp#7515

Change-Id: Ie93b232ab3e543d53062b462bdc13e279176f7a9
Co-authored-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali b0736fe6f7 ipn/ipnlocal: move selfNode from peerAPIServer to peerAPIHandler
The peerAPIHandler is instantiated per PeerAPI call so it is
guaranteed to have the latest selfNode.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 2f4fca65a1 ipn/ipnlocal: prevent duplicate profiles of the same user
Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick e9c851b04b ipn/ipnlocal: also accept service IP IPv6 literal in brackets for quad100
The fix in 4fc8538e2 was sufficient for IPv6. Browsers (can?) send the
IPv6 literal, even without a port number, in brackets.

Updates tailscale/corp#7948

Change-Id: I0e429d3de4df8429152c12f251ab140b0c8f6b77
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 296e712591 tailcfg: add CapabilityDebug
Updates tailscale/corp#7948

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 1e78fc462c ipn/ipnlocal: add some validation to PeerAPI
Updates tailscale/corp#7948

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 22238d897b all: standardize on PeerAPI
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 1b56acf513 ipn/ipnlocal: move LocalBackend.validPopBrowserURL empty check from caller
I was too late with review feedback to 513780f4f8.

Updates tailscale/corp#7948

Change-Id: I8fa3b4eba4efaff591a2d0bfe6ab4795638b7c3a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 513780f4f8 ipn/ipnlocal: move URL validation to LocalBackend
Updates tailscale/corp#7948

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 4fc8538e2f ipn/ipnlocal: check quad100 Host header in info page
Updates tailscale/corp#7948

Change-Id: I0ab61c764bff9ba8afaf9070db73e971eb018477
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 49b0ce8180 ipn/ipnlocal: update profile on server sent profile changes
We were not updating the LoginProfile.UserProfile when a netmap
updated the UserProfile (e.g. when a node was tagged via the admin panel).

Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick 6ea2d01626 ipn/ipnlocal: be more assertive about rules for applyPrefsToHostinfo (now Locked)
The old docs were too cagey.

Change-Id: I92c4fdc4165e7ca35c4537aebe51eb3604b56f6d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Mihai Parparita d3878ecd62 ipn/ipnlocal: add client metrics for profile switching
Updates #713

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Maisem Ali 235309adc4 all: store NL keys per profile
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>
2 years ago
Maisem Ali fe81ee62d7 ipn/ipnlocal: do controlclient.Shutdown in a different goroutine
We do not need to wait for it to complete. And we might have to
call Shutdown from callback from the controlclient which might
already be holding a lock that Shutdown requires.

Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Tom DNetto 42855d219b ipn/ipnlocal: fix checks for node-key presence in TKA logic
Found by tests in another repo. TKA code wasn't always checking enough to be sure a node-key was set for the current state.

Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Brad Fitzpatrick 7c285fe7ee ipn/ipnlocal: fix error message typo in ingress peerapi handler
Updates tailscale/corp#7515

Change-Id: I81edd7d9f8958eef61be71d3d34e545cd3347008
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 3114eacbb8 ipn/ipnlocal: don't warn about serve listener failing on IPv6-less machines
Fixes #6303

Change-Id: Ie1ce12938f68dfa0533246bbe3b9d7f3e749a243
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 3f8e185003 health: add Warnable, move ownership of warnable items to callers
The health package was turning into a rando dumping ground. Make a new
Warnable type instead that callers can request an instance of, and
then Set it locally in their code without the health package being
aware of all the things that are warnable. (For plenty of things the
health package will want to know details of how Tailscale works so it
can better prioritize/suppress errors, but lots of the warnings are
pretty leaf-y and unrelated)

This just moves two of the health warnings. Can probably move more
later.

Change-Id: I51e50e46eb633f4e96ced503d3b18a1891de1452
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali b87cb2c4a5 ipn/ipnlocal: call restart backend on user changes
This makes it so that the backend also restarts when users change,
otherwise an extra call to Start was required.

Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 8e85227059 cmd/tailscale/cli: [set] handle selectively modifying routes/exit node
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>
2 years ago
Maisem Ali 26d1fc867e ipn/ipnlocal: delete profile on logout
Updates #713

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 9e70daad6f ipn/ipnlocal: make TKA tests not have side effects
It left the envknob turned on which meant that running all the tests
in the package had different behavior than running just any one test.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
shayne 74e892cbc2
ipn/ipnlocal: listen to serve ports on netmap addrs (#6282)
Updates tailscale/corp#7515

Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
2 years ago
Brad Fitzpatrick 08e110ebc5 cmd/tailscale: make "up", "status" warn if routes and --accept-routes off
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>
2 years ago
Tom DNetto 4c31183781 cmd/tailscale,ipn: minor fixes to tailscale lock commands
* Fix broken add/remove key commands
 * Make lock status display whether the node is signed

Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Maisem Ali 6cc0036b40 ipn/ipnlocal: use updated prefs in tkaSyncIfNeeded
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali f00a49667d control/controlclient: make Status.Persist a PersistView
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 4d330bac14 ipn/ipnlocal: add support for multiple user profiles
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick c9d6a9cb4d ipn/ipnlocal: add optional TLS termination on proxied TCP connections
Updates tailscale/corp#7515

Change-Id: Ib250fa20275971563adccfa72db48e0cec02b7a5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Pat Maddox 9bf3ef4167 ssh/tailssh: add Tailscale SSH (server) support on FreeBSD
Change-Id: I607194b6ef99205e777f3df93a74ffe1a2e0344c
Signed-off-by: Pat Maddox <pat@ratiopbc.com>
2 years ago
shayne e3a66e4d2f
ipn/localapi: introduce get/set config for serve (#6243)
Updates tailscale/corp#7515

Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
2 years ago
Brad Fitzpatrick 7b5866ac0a ipn/ipnlocal: support serving files/directories too
Updates tailscale/corp#7515

Change-Id: I7b4c924005274ba57763264313d70d2a0c55da30
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick d7bfef12cf ipn/ipnlocal: support https+insecure:// backend proxy targets
Updates tailscale/corp#7515

Change-Id: Ie50295c09e4a16959b37087d8165c4d7360db37f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 9dfb0916c2 ipn/ipnlocal, tailcfg: wire up ingress peerapi
Updates tailscale/corp#7515

Co-authored-by: Shayne Sweeney <shayne@tailscale.com>
Change-Id: I7eac7b4ac37fd8e8a9e0469594c1e9e7dd0da666
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Aaron Klotz 73b8968404 ipn/ipnlocal: ensure Persist information is saved to server mode start state
Numerous issues have been filed concerning an inability to install and run
Tailscale headlessly in unattended mode, particularly after rebooting. The
server mode `Prefs` stored in `server-state.conf` were not being updated with
`Persist` state once the node had been succesfully logged in.

Users have been working around this by finagling with the GUI to make it force
a state rewrite. This patch makes that unnecessary by ensuring the required
server mode state is updated when prefs are updated by the control client.

Fixes https://github.com/tailscale/tailscale/issues/3186

Signed-off-by: Aaron Klotz <aaron@tailscale.com>
2 years ago
Brad Fitzpatrick 32a4ff3e5f ipn/ipnlocal: implement the reverse proxy HTTP handler type
Updates tailscale/corp#7515

Change-Id: Icbfe57f44b9516388edc0556eb04a370a9e3e009
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 6beb3184d5 ipn/ipnlocal: don't serve a TLS cert unless it has webserver config
Even if the name is right, or is configured on a different port.

Updates tailscale/corp#7515

Change-Id: I8b721968f3241af10d98431e1b5ba075223e6cd3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 1a94c309ea ipn/ipnlocal: support web TLS ports other than 443
Updates tailscale/corp#7515

Change-Id: I87df50b1bc92efd1d8c538c2ad4f1222361e4d6b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 4797bacb7c ipn/ipnlocal: send RST when serving an actionless TCPPortHandler
Updates tailscale/corp#7515

Change-Id: I790f1b5d1e8a887e39bb573b4610b8f37a3f5963
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick b683921b87 ipn/ipnlocal: add start of handling TCP proxying
Updates tailscale/corp#7515

Change-Id: I82d19b5864674b2169f25ec8e429f60a543e0c57
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 4bccc02413 ipn/ipnlocal: use ServerConfig views internally
Updates tailscale/corp#7515

Change-Id: Ica2bc44b92d281d5ce16cee55b7ca51c7910145c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 25e26c16ee ipn/ipnlocal: start implementing web server bits of serve
Updates tailscale/corp#7515

Change-Id: I96f4016161ba3c370492da941274c6d9a234c2bb
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick df5e40f731 ipn: add WebServerConfig, add views
cmd/viewer couldn't deal with that map-of-map. Add a wrapper type
instead, which also gives us a place to add future stuff.

Updates tailscale/corp#7515

Change-Id: I44a4ca1915300ea8678e5b0385056f0642ccb155
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 2daf0f146c ipn/ipnlocal, wgengine/netstack: start handling ports for future serving
Updates tailscale/corp#7515

Change-Id: I966e936e72a2ee99be8d0f5f16872b48cc150258
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 6d8320a6e9 ipn/{ipnlocal,localapi}: move most of cert.go to ipnlocal
Leave only the HTTP/auth bits in localapi.

Change-Id: I8e23fb417367f1e0e31483e2982c343ca74086ab
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick 5bb7e0307c cmd/tailscale, ipn/ipnlocal: add debug command to write to StateStore for dev
Not for end users (unless directed by support). Mostly for ease of
development for some upcoming webserver work.

Change-Id: I43acfed217514567acb3312367b24d620e739f88
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Brad Fitzpatrick da8def8e13 all: remove old +build tags
The //go:build syntax was introduced in Go 1.17:

https://go.dev/doc/go1.17#build-lines

gofmt has kept the +build and go:build lines in sync since
then, but enough time has passed. Time to remove them.

Done with:

    perl -i -npe 's,^// \+build.*\n,,' $(git grep -l -F '+build')

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Maisem Ali 6afe26575c ipn: make Notify.Prefs be a *ipn.PrefsView
It is currently a `ipn.PrefsView` which means when we do a JSON roundtrip,
we go from an invalid Prefs to a valid one.

This makes it a pointer, which fixes the JSON roundtrip.

This was introduced in 0957bc5af2.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick e55ae53169 tailcfg: add Node.UnsignedPeerAPIOnly to let server mark node as peerapi-only
capver 48

Change-Id: I20b2fa81d61ef8cc8a84e5f2afeefb68832bd904
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Andrew Dunham e975cb6b05 ipn/ipnlocal: fix test flake when we log after a test completes
This switches from using an atomic.Bool to a mutex for reasons that are
described in the commit, and should address the flakes that we're still
seeing.

Fixes #3020

Change-Id: I4e39471c0eb95886db03020ea1ccf688c7564a11
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
2 years ago
Tom DNetto 0af57fce4c cmd/tailscale,ipn: implement lock sign command
Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Brad Fitzpatrick 910db02652 client/tailscale, tsnet, ipn/ipnlocal: prove nodekey ownership over noise
Fixes #5972

Change-Id: Ic33a93d3613ac5dbf172d6a8a459ca06a7f9e547
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago
Tom DNetto d98305c537 cmd,ipn/ipnlocal,tailcfg: implement TKA disablement
* Plumb disablement values through some of the internals of TKA enablement.
 * Transmit the node's TKA hash at the end of sync so the control plane understands each node's head.
 * Implement /machine/tka/disable RPC to actuate disablement on the control plane.

There is a partner PR for the control server I'll send shortly.

Signed-off-by: Tom DNetto <tom@tailscale.com>
2 years ago
Anton Tolchanov 193afe19cb ipn/ipnlocal: add tags and a few other details to self status
This makes tags, creation time, exit node option and primary routes
for the current node exposed via `tailscale status --json`

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
2 years ago
Mihai Parparita 4e6e3bd13d ipn/ipnlocal: fix a log line having function pointers instead of values
Followup to using ipn.PrefsView (#6031).

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
2 years ago
Maisem Ali 2a9ba28def ipn/ipnlocal: set prefs before calling tkaSyncIfNeeded
Caught this in a test in a different repo.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 9f39c3b10f ipn/ipnlocal: make EditPrefs strip private keys before returning
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali a2d15924fb types/persist: add PublicNodeKey helper
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Maisem Ali 0957bc5af2 ipn/ipnlocal: use ipn.PrefsView
Signed-off-by: Maisem Ali <maisem@tailscale.com>
2 years ago
Brad Fitzpatrick def089f9c9 portlist: unexport all Poller fields, removing unused one, rework channels
Poller.C and Poller.c were duplicated for one caller. Add an accessor
returning the receive-only version instead. It'll inline.

Poller.Err was unused. Remove.

Then Poller is opaque.

The channel usage and shutdown was a bit sketchy. Clean it up.

And document some things.

Change-Id: I5669e54f51a6a13492cf5485c83133bda7ea3ce9
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 years ago