The Tailscale logging service has a hard limit on the maximum
log message size that can be accepted.
We want to ensure that netlog messages never exceed
this limit otherwise a client cannot transmit logs.
Move the goroutine for periodically dumping netlog messages
from wgengine/netlog to net/connstats.
This allows net/connstats to manage when it dumps messages,
either based on time or by size.
Updates tailscale/corp#8427
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
It's possible for the 'somethingChanged' callback to be registered and
then trigger before the ctx field is assigned; move the assignment
earlier so this can't happen.
Change-Id: Ia7ee8b937299014a083ab40adf31a8b3e0db4ec5
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
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>
Adjust the expected system output by removing the unsupported mask
component including and after the slash in expected output like:
fwmask 0xabc/0xdef
This package's tests now pass in an Alpine container when the 'go' and
'iptables' packages are installed (and run as privileged so /dev/net/tun
exists).
Fixes#5928
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Id1a3896282bfa36b64afaec7a47205e63ad88542
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>
We would replace the existing real implementation of nettype.PacketConn
with a blockForeverConn, but that violates the contract of atomic.Value
(where the type cannot change). Fix by switching to a pointer value
(atomic.Pointer[nettype.PacketConn]).
A longstanding issue, but became more prevalent when we started binding
connections to interfaces on macOS and iOS (#6566), which could lead to
the bind call failing if the interface was no longer available.
Fixes#6641
Signed-off-by: Mihai Parparita <mihai@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>
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 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>
There aren't any in the wild, other than one we ran on purpose to keep
us honest, but we can bump that one forward to 0.100.
Change-Id: I129e70724b2d3f8edf3b496dc01eba3ac5a2a907
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This renames canP2P in magicsock to canP2PLocked to reflect
expectation of mutex lock, fixes a race we discovered in the meantime,
and updates the current stats.
Co-authored-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Jenny Zhang <jz@tailscale.com>
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>
Noticed when testing FUS on tailscale-on-macOS, that routing would break
completely when switching between profiles. However, it would start working
again when going back to the original profile tailscaled started with.
Turns out that if we change the addrs on the interface we need to remove and readd
all the routes.
Updates #713
Signed-off-by: Maisem Ali <maisem@tailscale.com>
All IPv6 packets for the self address were doing netip.Prefix.Contains
lookups.
If if we know they're for a self address (which we already previously
computed and have sitting in a bool), then they can't be for a 4via6
range.
Change-Id: Iaaaf1248cb3fecec229935a80548ead0eb4cb892
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Inspired by #6235, let's explicitly test the behaviour of this function
to ensure that we're not processing things we don't expect to.
Change-Id: I158050a63be7410fb99452089ea607aaf89fe91a
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
It was eating TCP packets to peerapi ports to subnet routers. Some of
the TCP flow's packets went onward, some got eaten. So some TCP flows
to subnet routers, if they used an unfortunate TCP port number, got
broken.
Change-Id: Ifea036119ccfb081f4dfa18b892373416a5239f8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
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>
It's leftover from an earlier Tailscale SSH wiring and I forgot to
delete it apparently.
Change-Id: I14f071f450e272b98d90080a71ce68ba459168d1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Exit node traffic is aggregated to protect the privacy
of those using an exit node. However, it is reasonable to
at least log which nodes are making most use of an exit node.
For a node using an exit node,
the source will be the taiscale IP address of itself,
while the destination will be zeroed out.
For a node that serves as an exit node,
the source will be zeroed out,
while the destination will be tailscale IP address
of the node that initiated the exit traffic.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
In the future this will cause a node to be unable to join the tailnet
if network logging is enabled.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Setting TCP KeepAlives for Tailscale SSH connections results in them
unnecessarily disconnecting. However, we can't turn them off completely
as that would mean we start leaking sessions waiting for a peer to come
back which may have gone away forever (e.g. if the node was deleted from
the tailnet during a session).
Updates #5021
Signed-off-by: Maisem Ali <maisem@tailscale.com>
If the network logging configruation changes (and nothing else)
we will tear down the network logger and start it back up.
However, doing so will lose the router configuration state.
Manually reconfigure it with the routing state.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This is a temporary hack to prevent logtail getting stuck
uploading the same excessive message over and over.
A better solution will be discussed and implemented.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
There is utility in logging traffic statistics that occurs at the physical layer.
That is, in order to send packets virtually to a particular tailscale IP address,
what physical endpoints did we need to communicate with?
This functionality logs IP addresses identical to
what had always been logged in magicsock prior to #5823,
so there is no increase in PII being logged.
ExtractStatistics returns a mapping of connections to counts.
The source is always a Tailscale IP address (without port),
while the destination is some endpoint reachable on WAN or LAN.
As a special case, traffic routed through DERP will use 127.3.3.40
as the destination address with the port being the DERP region.
This entire feature is only enabled if data-plane audit logging
is enabled on the tailnet (by default it is disabled).
Example of type of information logged:
------------------------------------ Tx[P/s] Tx[B/s] Rx[P/s] Rx[B/s]
PhysicalTraffic: 25.80 3.39Ki 38.80 5.57Ki
100.1.2.3 -> 143.11.22.33:41641 15.40 2.00Ki 23.20 3.37Ki
100.4.5.6 -> 192.168.0.100:41641 10.20 1.38Ki 15.60 2.20Ki
100.7.8.9 -> 127.3.3.40:2 0.20 6.40 0.00 0.00
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
The netlog.Message type is useful to depend on from other packages,
but doing so would transitively cause gvisor and other large packages
to be linked in.
Avoid this problem by moving all network logging types to a single package.
We also update staticcheck to take in:
003d277bcf
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Intermittently in the wild we are seeing failures when calling
`INetworkConnection::GetNetwork`. It is unclear what the root cause is, but what
is clear is that the error is happening inside the object's `IDispatch` invoker
(as opposed to the method implementation itself).
This patch replaces our wrapper for `INetworkConnection::GetNetwork` with an
alternate implementation that directly invokes the method, instead of using
`IDispatch`. I also replaced the implementations of `INetwork::SetCategory` and
`INetwork::GetCategory` while I was there.
This patch is speculative and tightly-scoped so that we could possibly add it
to a dot-release if necessary.
Updates https://github.com/tailscale/tailscale/issues/4134
Updates https://github.com/tailscale/tailscale/issues/6037
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
TCP selective acknowledgement can improve throughput by an order
of magnitude in the presence of loss.
Signed-off-by: Jordan Whited <jordan@tailscale.com>
We had previously added this to the netcheck report in #5087 but never
copied it into the NetInfo struct. Additionally, add it to log lines so
it's visible to support.
Change-Id: Ib6266f7c6aeb2eb2a28922aeafd950fe1bf5627e
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Deleting may temporarily result in no addrs on the interface, which results in
all other rules (like routes) to get dropped by the OS.
I verified this fixes the problem.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Sets up new file for separate silent disco goroutine, tentatively named
pathfinder for now.
Updates #540
Co-authored-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Jenny Zhang <jz@tailscale.com>
During development of silent disco (#540), an alternate send policy
for magicsock that doesn't wake up the radio frequently with
heartbeats, we want the old & new policies to coexist, like we did
previously pre- and post-disco.
We started to do that earlier in 5c42990c2f but only set up the
env+control knob plumbing to set a bool about which path should be
used.
This starts to add a way for the silent disco code to update the send
path from a separate goroutine. (Part of the effort is going to
de-state-machinify the event based soup that is the current disco
code and make it more Go synchronous style.)
So far this does nothing. (It does add an atomic load on each send
but that should be noise in the grand scheme of things, and a even more
rare atomic store of nil on node config changes.)
Baby steps.
Updates #540
Co-authored-by: Jenny Zhang <jz@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The wireguard-go code unfortunately calls this unconditionally
even when verbose logging is disabled.
Partial revert of #5911.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This field seems seldom used and the documentation is wrong.
It is simpler to just derive its original value dynamically
when endpoint.DstToString is called.
This method is potentially used by wireguard-go,
but not in any code path is performance sensitive.
All calls to it use it in conjunction with fmt.Printf,
which is going to be slow anyways since it uses Go reflection.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
- At high data rates more buffer space is required in order to avoid
packet loss during any cause of delay.
- On slower machines more buffer space is required in order to avoid
packet loss while decryption & tun writing is underway.
- On higher latency network paths more buffer space is required in order
to overcome BDP.
- On Linux set with SO_*BUFFORCE to bypass net.core.{r,w}mem_max.
- 7MB is the current default maximum on macOS 12.6
- Windows test is omitted, as Windows does not support getsockopt for
these options.
Signed-off-by: James Tucker <james@tailscale.com>
Always set the MTU to the Tailscale default MTU. In practice we are
missing applying an MTU for IPv6 on Windows prior to this patch.
This is the simplest patch to fix the problem, the code in here needs
some more refactoring.
Fixes#5914
Signed-off-by: James Tucker <james@tailscale.com>
This sets up Logger to handle statistics at the magicsock layer,
where we can correlate traffic between a particular tailscale IP address
and any number of physical endpoints used to contact the node
that hosts that tailscale address.
We also export Message and TupleCounts to better document the JSON format
that is being sent to the logging infrastructure.
This commit does NOT yet enable the actual logging of magicsock statistics.
That will be a future commit.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
If the wgcfg.Config is specified with network logging arguments,
then Userspace.Reconfig starts up an asynchronous network logger,
which is shutdown either upon Userspace.Close or when Userspace.Reconfig
is called again without network logging or route arguments.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
The Logger type managers a logtail.Logger for extracting
statistics from a tstun.Wrapper.
So long as Shutdown is called, it ensures that logtail
and statistic gathering resources are properly cleared up.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
The node and domain audit log IDs are provided in the map response,
but are ultimately going to be used in wgengine since
that's the layer that manages the tstun.Wrapper.
Do the plumbing work to get this field passed down the stack.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
And add a CLI/localapi and c2n mechanism to enable it for a fixed
amount of time.
Updates #1548
Change-Id: I71674aaf959a9c6761ff33bbf4a417ffd42195a7
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Most visible when using tsnet.Server, but could have resulted in dropped
messages in a few other places too.
Fixes#5743
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Context: https://github.com/tailscale/tailscale/pull/5588#issuecomment-1260655929
It seems that if the interface at index 1 is down, the rule is not installed. As such,
we increase the range we detect up to 2004 in the hope that at least one of the interfaces
1-4 will be up.
Signed-off-by: Tom DNetto <tom@tailscale.com>
This fixes a race condition which caused `c.muCond.Broadcast()` to
never fire in the `firstDerp` if block. It resulted in `Close()`
hanging forever.
Signed-off-by: Kyle Carberry <kyle@carberry.com>
As the comment in the code says, netstack should always respond to ICMP
echo requests to a 4via6 address, even if the netstack instance isn't
normally processing subnet traffic.
Follow-up to #5709
Change-Id: I504d0776c5824071b2a2e0e687bc33e24f6c4746
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
From 5c42990c2f, not yet released in a stable build.
Caught by existing tests.
Fixes#5685
Change-Id: Ia76bb328809d9644e8b96910767facf627830600
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Baby steps towards turning off heartbeat pings entirely as per #540.
This doesn't change any current magicsock functionality and requires additional
changes to send/disco paths before the flag can be turned on.
Updates #540
Change-Id: Idc9a72748e74145b068d67e6dd4a4ffe3932efd0
Signed-off-by: Jenny Zhang <jz@tailscale.com>
Signed-off-by: Jenny Zhang <jz@tailscale.com>
The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.
Reference: https://golang.org/doc/go1.16#ioutil
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
This change masks the bitspace used when setting and querying the fwmark on packets. This allows
tailscaled to play nicer with other networking software on the host, assuming the other networking
software is also using fwmarks & a different mask.
IPTables / mark module has always supported masks, so this is safe on the netfilter front.
However, busybox only gained support for parsing + setting masks in 1.33.0, so we make sure we
arent such a version before we add the "/<mask>" syntax to an ip rule command.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Fixes an panic in `(*magicsock.Conn).ServeHTTPDebug` when the
`recentPongs` ring buffer for an endpoint wraps around.
Signed-off-by: Colin Adler <colin1adler@gmail.com>
If we accept a forwarded TCP connection before dialing, we can
erroneously signal to a client that we support IPv6 (or IPv4) without
that actually being possible. Instead, we only complete the client's TCP
handshake after we've dialed the outbound connection; if that fails, we
respond with a RST.
Updates #5425 (maybe fixes!)
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Incoming disco packets are now dropped unless they match one of the
current bound ports, or have a zero port*.
The BPF filter passes all packets with a disco header to the raw packet
sockets regardless of destination port (in order to avoid needing to
reconfigure BPF on rebind).
If a BPF enabled node has just rebound, due to restart or rebind, it may
receive and reply to disco ping packets destined for ports other than
those which are presently bound. If the pong is accepted, the pinging
node will now assume that it can send WireGuard traffic to the pinged
port - such traffic will not reach the node as it is not destined for a
bound port.
*The zero port is ignored, if received. This is a speculative defense
and would indicate a problem in the receive path, or the BPF filter.
This condition is allowed to pass as it may enable traffic to flow,
however it will also enable problems with the same symptoms this patch
otherwise fixes.
Fixes#5536
Signed-off-by: James Tucker <james@tailscale.com>
1f959edeb0 introduced a regression for JS
where the initial bind no longer occurred at all for JS.
The condition is moved deeper in the call tree to avoid proliferation of
higher level conditions.
Updates #5537
Signed-off-by: James Tucker <james@tailscale.com>
Both RebindingUDPConns now always exist. the initial bind (which now
just calls rebind) now ensures that bind is called for both, such that
they both at least contain a blockForeverConn. Calling code no longer
needs to assert their state.
Signed-off-by: James Tucker <james@tailscale.com>
This is entirely optional (i.e. failing in this code is non-fatal) and
only enabled on Linux for now. Additionally, this new behaviour can be
disabled by setting the TS_DEBUG_DISABLE_AF_PACKET environment variable.
Updates #3824
Replaces #5474
Co-authored-by: Andrew Dunham <andrew@du.nham.ca>
Signed-off-by: David Anderson <danderson@tailscale.com>
On sufficiently large tailnets, even writing the peer header (~95 bytes)
can result in a large amount of data that needs to be serialized and
deserialized. Only write headers for peers that need to have their
configuration changed.
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Avoid contention from fetching status for all peers, and instead fetch
status for a single peer.
Updates tailscale/coral#72
Signed-off-by: James Tucker <james@tailscale.com>
In addition to printing goroutine stacks, explicitly track all in-flight
operations and print them when the watchdog triggers (along with the
time they were started at). This should make debugging watchdog failures
easier, since we can look at the longest-running operation(s) first.
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
The Start method was removed in 4c27e2fa22, but the comment on NewConn
still mentioned it doesn't do anything until this method is called.
Signed-off-by: Kris Brandow <kris.brandow@gmail.com>
Hashing []any is slow since hashing of interfaces is slow.
Hashing of interfaces is slow since we pessimistically assume
that cycles can occur through them and start cycle tracking.
Drop the variadic signature of Update and fix callers to pass in
an anonymous struct so that we are hashing concrete types
near the root of the value tree.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This adds a lighter mechanism for endpoint updates from control.
Change-Id: If169c26becb76d683e9877dc48cfb35f90cc5f24
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The iOS and macOS networking extension API only exposes a single setter
for the entire routing and DNS configuration, and does not appear to
do any kind of diffing or deltas when applying changes. This results
in spurious "network changed" errors in Chrome, even when the
`OneCGNATRoute` flag from df9ce972c7 is
used (because we're setting the same configuration repeatedly).
Since we already keep track of the current routing and DNS configuration
in CallbackRouter, use that to detect if they're actually changing, and
only invoke the platform setter if it's actually necessary.
Updates #3102
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Link-local addresses on the Tailscale interface are not routable.
Ideally they would be removed, however, a concern exists that the
operating system will attempt to re-add them which would lead to
thrashing.
Setting SkipAsSource attempts to avoid production of packets using the
address as a source in any default behaviors.
Before, in powershell: `ping (hostname)` would ping the link-local
address of the Tailscale interface, and fail.
After: `ping (hostname)` now pings the link-local address on the next
highest priority metric local interface.
Fixes#4647
Signed-off-by: James Tucker <james@tailscale.com>
Per post-submit code review feedback of 1336fb740b from @maisem.
Change-Id: Ic5c16306cbdee1029518448642304981f77ea1fd
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Fixes#4647
It seems that Windows creates a link-local address for the TUN driver, seemingly
based on the (fixed) adapter GUID. This results in a fixed MAC address, which
for some reason doesn't handle loopback correctly. Given the derived link-local
address is preferred for lookups (thanks LLMNR), traffic which addresses the
current node by hostname uses this broken address and never works.
To address this, we remove the broken link-local address from the wintun adapter.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Profiling identified this as a fairly hot path for growing a slice.
Given this is only used in control & when a new packet filter is received, this shouldnt be hot in the client.
We were marking them as gauges, but they are only ever incremented,
thus counter is more appropriate.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
* net/dns, wgengine: implement DNS over TCP
Signed-off-by: Tom DNetto <tom@tailscale.com>
* wgengine/netstack: intercept only relevant port/protocols to quad-100
Signed-off-by: Tom DNetto <tom@tailscale.com>
This were intended to be pushed to #4408, but in my excitement I
forgot to git push :/ better late than never.
Signed-off-by: Tom DNetto <tom@tailscale.com>
This change wires netstack with a hook for traffic coming from the host
into the tun, allowing interception and handling of traffic to quad-100.
With this hook wired, magicDNS queries over UDP are now handled within
netstack. The existing logic in wgengine to handle magicDNS remains for now,
but its hook operates after the netstack hook so the netstack implementation
takes precedence. This is done in case we need to support platforms with
netstack longer than expected.
Signed-off-by: Tom DNetto <tom@tailscale.com>
A subsequent commit implements handling of magicDNS traffic via netstack.
Implementing this requires a hook for traffic originating from the host and
hitting the tun, so we make another hook to support this.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Well, goimports actually (which adds the normal import grouping order we do)
Change-Id: I0ce1b1c03185f3741aad67c14a7ec91a838de389
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Setting keepalive ensures that idle connections will eventually be
closed. In userspace mode, any application configured TCP keepalive is
effectively swallowed by the host kernel, and is not easy to detect.
Failure to close connections when a peer tailscaled goes offline or
restarts may result in an otherwise indefinite connection for any
protocol endpoint that does not initiate new traffic.
This patch does not take any new opinion on a sensible default for the
keepalive timers, though as noted in the TODO, doing so likely deserves
further consideration.
Update #4522
Signed-off-by: James Tucker <james@tailscale.com>
One current theory (among other things) on battery consumption is that
magicsock is resorting to using the IPv6 over LTE even on WiFi.
One thing that could explain this is that we do not get link change updates
for the LTE modem as we ignore them in this list.
This commit makes us not ignore changes to `pdp_ip` as a test.
Updates #3363
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This reverts commit 8d6793fd70.
Reason: breaks Android build (cgo/pthreads addition)
We can try again next cycle.
Change-Id: I5e7e1730a8bf399a8acfce546a6d22e11fb835d5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Attempt to load the xt_mark kernel module when it is not present. If the
load fails, log error information.
It may be tempting to promote this failure to an error once it has been
in use for some time, so as to avoid reaching an error with the iptables
invocation, however, there are conditions under which the two stages may
disagree - this change adds more useful breadcrumbs.
Example new output from tailscaled running under my WSL2:
```
router: ensure module xt_mark: "/usr/sbin/modprobe xt_mark" failed: exit status 1; modprobe: FATAL: Module xt_mark not found in directory /lib/modules/5.10.43.3-microsoft-standard-WSL2
```
Background:
There are two places to lookup modules, one is `/proc/modules` "old",
the other is `/sys/module/` "new".
There was query_modules(2) in linux <2.6, alas, it is gone.
In a docker container in the default configuration, you would get
/proc/modules and /sys/module/ both populated. lsmod may work file,
modprobe will fail with EPERM at `finit_module()` for an unpriviliged
container.
In a priviliged container the load may *succeed*, if some conditions are
met. This condition should be avoided, but the code landing in this
change does not attempt to avoid this scenario as it is both difficult
to detect, and has a very uncertain impact.
In an nspawn container `/proc/modules` is populated, but `/sys/module`
does not exist. Modern `lsmod` versions will fail to gather most module
information, without sysfs being populated with module information.
In WSL2 modules are likely missing, as the in-use kernel typically is
not provided by the distribution filesystem, and WSL does not mount in a
module filesystem of its own. Notably the WSL2 kernel supports iptables
marks without listing the xt_mark module in /sys/module, and
/proc/modules is empty.
On a recent kernel, we can ask the capabilities system about SYS_MODULE,
that will help to disambiguate between the non-privileged container case
and just being root. On older kernels these calls may fail.
Update #4329
Signed-off-by: James Tucker <james@tailscale.com>
It unfortuantely gets truncated because it's too long, split it into 3
different log lines to circumvent truncation.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Currently we ignore these interfaces in the darwin osMon but then would consider it
interesting when checking if anything had changed.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
In `(*Mon).Start` we don't run a timer to update `(*Mon).lastWall` on iOS and
Android as their sleep patterns are bespoke. However, in the debounce
goroutine we would notice that the the wall clock hadn't been updated
since the last event would assume that a time jump had occurred. This would
result in non-events being considered as major-change events.
This commit makes it so that `(*Mon).timeJumped` is never set to `true`
on iOS and Android.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Remove the weird netstack -> tailssh dependency and instead have tailssh
register itself with ipnlocal when linked.
This makes tailssh.server a singleton, so we can have a global map of
all sessions.
Updates #3802
Change-Id: Iad5caec3a26a33011796878ab66b8e7b49339f29
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This defines a new magic IPv6 prefix, fd7a:115c:a1e0:b1a::/64, a
subset of our existing /48, where the final 32 bits are an IPv4
address, and the middle 32 bits are a user-chosen "site ID". (which
must currently be 0000:00xx; the top 3 bytes must be zero for now)
e.g., I can say my home LAN's "site ID" is "0000:00bb" and then
advertise its 10.2.0.0/16 IPv4 range via IPv6, like:
tailscale up --advertise-routes=fd7a:115c:a1e0:b1a::bb:10.2.0.0/112
(112 being /128 minuse the /96 v6 prefix length)
Then people in my tailnet can:
$ curl '[fd7a:115c:a1e0:b1a::bb:10.2.0.230]'
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" ....
Updates #3616, etc
RELNOTE=initial support for TS IPv6 addresses to route v4 "via" specific nodes
Change-Id: I9b49b6ad10410a24b5866b9fbc69d3cae1f600ef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Ignoring the events at this layer is the simpler path for right now, a
broader change should follow to suppress irrelevant change events in a
higher layer so as to avoid related problems with other monitoring paths
on other platforms. This approach may also carry a small risk that it
applies an at-most-once invariant low in the chain that could be assumed
otherwise higher in the code.
I adjusted the newAddrMessage type to include interface index rather
than a label, as labels are not always supplied, and in particular on my
test hosts they were consistently missing for ipv6 address messages.
I adjusted the newAddrMessage.Addr field to be populated from
Attributes.Address rather than Attributes.Local, as again for ipv6
.Local was always empty, and with ipv4 the .Address and .Local contained
the same contents in each of my test environments.
Update #4282
Signed-off-by: James Tucker <james@tailscale.com>
While I trust the test behavior, I also want to assert the behavior in a
reproduction environment, this envknob gives me the log information I
need to do so.
Update #4282
Signed-off-by: James Tucker <james@tailscale.com>
* net/dns, net/dns/resolver, wgengine: refactor DNS request path
Previously, method calls into the DNS manager/resolver types handled DNS
requests rather than DNS packets. This is fine for UDP as one packet
corresponds to one request or response, however will not suit an
implementation that supports DNS over TCP.
To support PRs implementing this in the future, wgengine delegates
all handling/construction of packets to the magic DNS endpoint, to
the DNS types themselves. Handling IP packets at this level enables
future support for both UDP and TCP.
Signed-off-by: Tom DNetto <tom@tailscale.com>
In addition an envknob (TS_DEBUG_NETSTACK_LEAK_MODE) now provides access
to set leak tracking to more useful values.
Fixes#4309
Signed-off-by: James Tucker <james@tailscale.com>
When `setWgengineStatus` is invoked concurrently from multiple
goroutines, it is possible that the call invoked with a newer status is
processed before a call with an older status. e.g. a status that has
endpoints might be followed by a status without endpoints. This causes
unnecessary work in the engine and can result in packet loss.
This patch adds an `AsOf time.Time` field to the status to specifiy when the
status was calculated, which later allows `setWgengineStatus` to ignore
any status messages it receives that are older than the one it has
already processed.
Updates tailscale/corp#2579
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Plumb the outbound injection path to allow passing netstack
PacketBuffers down to the tun Read, where they are decref'd to enable
buffer re-use. This removes one packet alloc & copy, and reduces GC
pressure by pooling outbound injected packets.
Fixes#2741
Signed-off-by: James Tucker <james@tailscale.com>
The version string changed slightly. Adapt.
And always check the current Go version to prevent future
accidental regressions. I would have missed this one had
I not explicitly manually checked it.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
This was just cleanup for an ancient version of Tailscale. Any such machines
have upgraded since then.
Change-Id: Iadcde05b37c2b867f92e02ec5d2b18bf2b8f653a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
For local dev testing initially. Product-wise, it'll probably only be
workable on the two unsandboxed builds.
Updates #3802
Change-Id: Ic352f966e7fb29aff897217d79b383131bf3f92b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Still largely incomplete, but in a better home now.
Updates #3802
Change-Id: I46c5ffdeb12e306879af801b06266839157bc624
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We're finding a bunch of host operating systems/firewalls interact poorly
with peerapi. We either get ICMP errors from the host or users need to run
commands to allow the peerapi port:
https://github.com/tailscale/tailscale/issues/3842#issuecomment-1025133727
... even though the peerapi should be an internal implementation detail.
Rather than fight the host OS & firewalls, this change handles the
server side of peerapi entirely in netstack (except on iOS), so it
never makes its way to the host OS where it might be messed with. Two
main downsides are:
1) netstack isn't as fast, but we don't really need speed for peerapi.
And actually, with fewer trips to/from the kernel, we might
actually make up for some of the netstack performance loss by
staying in userspace.
2) tcpdump / Wireshark etc packet captures will no longer see the peerapi
traffic. Oh well. Crawshaw's been wanting to add packet capture server
support to tailscaled, so we'll probably do that sooner now.
A future change might also then use peerapi for the client-side
(except on iOS).
Updates #3842 (probably fixes, as well as many exit node issues I bet)
Change-Id: Ibc25edbb895dc083d1f07bd3cab614134705aa39
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Now that Go 1.17 has module graph pruning
(https://go.dev/doc/go1.17#go-command), we should be able to use
upstream netstack without breaking our private repo's build
that then depends on the tailscale.com Go module.
This is that experiment.
Updates #1518 (the original bug to break out netstack to own module)
Updates #2642 (this updates netstack, but doesn't remove workaround)
Change-Id: I27a252c74a517053462e5250db09f379de8ac8ff
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Disabled by default.
To use, run tailscaled with:
TS_SSH_ALLOW_LOGIN=you@bar.com
And enable with:
$ TAILSCALE_USE_WIP_CODE=true tailscale up --ssh=true
Then ssh [any-user]@[your-tailscale-ip] for a root bash shell.
(both the "root" and "bash" part are temporary)
Updates #3802
Change-Id: I268f8c3c95c8eed5f3231d712a5dc89615a406f0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
A new package can also later record/report which knobs are checked and
set. It also makes the code cleaner & easier to grep for env knobs.
Change-Id: Id8a123ab7539f1fadbd27e0cbeac79c2e4f09751
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This fixes a deadlock on shutdown.
One goroutine is waiting to send on c.derpRecvCh before unlocking c.mu.
The other goroutine is waiting to lock c.mu before receiving from c.derpRecvCh.
#3736 has a more detailed explanation of the sequence of events.
Fixes#3736
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
-W is milliseconds on darwin, not seconds, and empirically it's
milliseconds after a 1 second base.
Change-Id: I2520619e6699d9c505d9645ce4dfee4973555227
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Turning this on at the beginning of the 1.21.x dev cycle, for 1.22.
Updates #150
Change-Id: I1de567cfe0be3df5227087de196ab88e60c9eb56
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Except for the super verbose packet-level dumps. Keep those disabled
by default with a const.
Updates #2642
Change-Id: Ia9eae1677e8b3fe6f457a59e44896a335d95d547
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The blockForeverConn was only using its sync.Cond one side. Looks like it
was just forgotten.
Fixes#3671
Change-Id: I4ed0191982cdd0bfd451f133139428a4fa48238c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Bigger changes coming later, but this should improve things a bit in
the meantime.
Rationale:
* 2 minutes -> 45 seconds: 2 minutes was overkill and never considered
phones/battery at the time. It was totally arbitrary. 45 seconds is
also arbitrary but is less than 2 minutes.
* heartbeat from 2 seconds to 3 seconds: in practice this meant two
packets per second (2 pings and 2 pongs every 2 seconds) because the
other side was also pinging us every 2 seconds on their own.
That's just overkill. (see #540 too)
So in the worst case before: when we sent a single packet (say: a DNS
packet), we ended up sending 61 packets over 2 minutes: the 1 DNS
query and then then 60 disco pings (2 minutes / 2 seconds) & received
the same (1 DNS response + 60 pongs). Now it's 15. In 1.22 we plan to
remove this whole timer-based heartbeat mechanism entirely.
The 5 seconds to 6.5 seconds change is just stretching out that
interval so you can still miss two heartbeats (other 3 + 3 seconds
would be greater than 5 seconds). This means that if your peer moves
without telling you, you can have a path out for 6.5 seconds
now instead of 5 seconds before disco finds a new one. That will also
improve in 1.22 when we start doing UDP+DERP at the same time
when confidence starts to go down on a UDP path.
Updates #3363
Change-Id: Ic2314bbdaf42edcdd7103014b775db9cf4facb47
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Fixes#3660
RELNOTE=MagicDNS now works over IPv6 when CGNAT IPv4 is disabled.
Change-Id: I001e983df5feeb65289abe5012dedd177b841b45
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Treat UDP send EPERM errors as a lost UDP packet, not something super
fatal. That's just the Linux firewall preventing it from going out.
And add a leaf package net/neterror for that (and future) policy that
all three packages can share, with tests.
Updates #3619
Change-Id: Ibdb838c43ee9efe70f4f25f7fc7fdf4607ba9c1d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Only if the source address isn't on the currently active interface or
a ping of the DERP server fails.
Updates #3619
Change-Id: I6bf06503cff4d781f518b437c8744ac29577acc8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We only tracked the transport type (UDP vs DERP), not what they were.
Change-Id: Ia4430c1c53afd4634e2d9893d96751a885d77955
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The intent of the updateIPs code is to add & remove IP addresses
to netstack based on what we get from the netmap.
But netstack itself adds 255.255.255.255/32 apparently and we always
fight it (and it adds it back?). So stop fighting it.
Updates #2642 (maybe fixes? maybe.)
Change-Id: I37cb23f8e3f07a42a1a55a585689ca51c2be7c60
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
magicsock was hanging onto its netmap on logout,
which caused tailscale status to display partial
information about a bunch of zombie peers.
After logout, there should be no peers.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
And it updates the build tag style on a couple files.
Change-Id: I84478d822c8de3f84b56fa1176c99d2ea5083237
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
on error.
While debugging a customer issue where the firewallTweaker was failing
the only message we have is `router: firewall: error adding
Tailscale-Process rule: exit status 1` which is not really helpful.
This will help diagnose firewall tweaking failures.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
It's been a bunch of releases now since the TailscaleIPs slice
replacement was added.
Change-Id: I3bd80e1466b3d9e4a4ac5bedba8b4d3d3e430a03
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Allow users of CallbackRouter to supply a GetBaseConfig
implementation. This is expected to be used on Android,
which currently lacks both a) platform support for
Split-DNS and b) a way to retrieve the current DNS
servers.
iOS/macOS also use the CallbackRouter but have platform
support for SplitDNS, so don't need getBaseConfig.
Updates https://github.com/tailscale/tailscale/issues/2116
Updates https://github.com/tailscale/tailscale/issues/988
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
And simplify, unexport some tsdial/netstack stuff in the the process.
Fixes#3475
Change-Id: I186a5a5cbd8958e25c075b4676f7f6e70f3ff76e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This starts to refactor tsdial.Dialer's name resolution to have
different stages: in-memory MagicDNS vs system resolution. A future
change will plug in ExitDNS resolution.
This also plumbs a Dialer into netstack and unexports the dnsMap
internals.
And it removes some of the async AddNetworkMapCallback usage and
replaces it with synchronous updates of the Dialer's netmap
from LocalBackend, since the LocalBackend has the Dialer too.
Updates #3475
Change-Id: Idcb7b1169878c74f0522f5151031ccbc49fe4cb4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In prep for moving stuff out of LocalBackend.
Change-Id: I9725aa9c3ebc7275f8c40e040b326483c0340127
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Not done yet, but this move more of the outbound dial special casing
from random packages into tsdial, which aspires to be the one unified
place for all outbound dialing shenanigans.
Then this plumbs it all around, so everybody is ultimately
holding on to the same dialer.
As of this commit, macOS/iOS using an exit node should be able to
reach to the exit node's DoH DNS proxy over peerapi, doing the sockopt
to stay within the Network Extension.
A number of steps remain, including but limited to:
* move a bunch more random dialing stuff
* make netstack-mode tailscaled be able to use exit node's DNS proxy,
teaching tsdial's resolver to use it when an exit node is in use.
Updates #1713
Change-Id: I1e8ee378f125421c2b816f47bc2c6d913ddcd2f5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The behavior was changed in March (in 7f174e84e6)
but that change forgot to update these docs.
Change-Id: I79c0301692c1d13a4a26641cc5144baf48ec1360
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
For now this just deletes the net/socks5/tssocks implementation (and
the DNSMap stuff from wgengine/netstack) and moves it into net/tsdial.
Then initialize a Dialer early in tailscaled, currently only use for the
outbound and SOCKS5 proxies. It will be plumbed more later. Notably, it
needs to get down into the DNS forwarder for exit node DNS forwading
in netstack mode. But it will also absorb all the peerapi setsockopt
and netns Dial and tlsdial complexity too.
Updates #1713
Change-Id: Ibc6d56ae21a22655b2fa1002d8fc3f2b2ae8b6df
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I probably broke it when SCTP support was added but nothing apparently
ever used NewAllowAllForTest so it wasn't noticed when it broke.
Change-Id: Ib5a405be233d53cb7fcc61d493ae7aa2d1d590a2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
One of the most common "unexpected" log lines is:
"network state changed, but stringification didn't"
One way that this can occur is if an interesting interface
(non-Tailscale, has interesting IP address)
gains or loses an uninteresting IP address (link local or loopback).
The fact that the interface is interesting is enough for EqualFiltered
to inspect it. The fact that an IP address changed is enough for
EqualFiltered to declare that the interfaces are not equal.
But the State.String method reasonably declines to print any
uninteresting IP addresses. As a result, the network state appears
to have changed, but the stringification did not.
The String method is correct; nothing interesting happened.
This change fixes this by adding an IP address filter to EqualFiltered
in addition to the interface filter. This lets the network monitor
ignore the addition/removal of uninteresting IP addresses.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
In rare circumstances (tailscale/corp#3016), the PublicKey
and Endpoints can diverge.
This by itself doesn't cause any harm, but our early exit
in response did, because it prevented us from recovering from it.
Remove the early exit.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Tailscale 1.18 uses netlink instead of the "ip" command to program the
Linux kernel.
The old way was kept primarily for tests, but this also adds a
TS_DEBUG_USE_IP_COMMAND environment knob to force the old way
temporarily for debugging anybody who might have problems with the
new way in 1.18.
Updates #391
Change-Id: I0236fbfda6c9c05dcb3554fcc27ec0c86456efd9
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
endpoint.discoKey is protected by endpoint.mu.
endpoint.sendDiscoMessage was reading it without holding the lock.
This showed up in a CI failure and is readily reproducible locally.
The fix is in two parts.
First, for Conn.enqueueCallMeMaybe, eliminate the one-line helper method endpoint.sendDiscoMessage; call Conn.sendDiscoMessage directly.
This makes it more natural to read endpoint.discoKey in a context
in which endpoint.mu is already held.
Second, for endpoint.sendDiscoPing, explicitly pass the disco key
as an argument. Again, this makes it easier to read endpoint.discoKey
in a context in which endpoint.mu is already held.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
I believe that this should eliminate the flakiness.
If GitHub CI manages to be even slower that can be believed
(and I can believe a lot at this point),
then we should roll this back and make some more invasive changes.
Updates #654Fixes#3247 (I hope)
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
We can do the "maybe delete" check unilaterally:
In the case of an insert, both oldDiscoKey
and ep.discoKey will be the zero value.
And since we don't use pi again, we can skip
giving it a name, which makes scoping clearer.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
wgengine/wgcfg: introduce wgcfg.NewDevice helper to disable roaming
at all call sites (one real plus several tests).
Fixestailscale/corp#3016.
Signed-off-by: David Anderson <danderson@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
And annotate magicsock as a start.
And add localapi and debug handlers with the Prometheus-format
exporter.
Updates #3307
Change-Id: I47c5d535fe54424741df143d052760387248f8d3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In DeviceConfig, we did not close r after calling FromUAPI.
If FromUAPI returned early due to an error, then it might
not have read all the data that IpcGetOperation wanted to write.
As a result, IpcGetOperation could hang, as in #3220.
We were also closing the wrong end of the pipe after IpcSetOperation
in ReconfigDevice.
To ensure that we get all available information to diagnose
such a situation, include all errors anytime something goes wrong.
This should fix the immediate crashing problem in #3220.
We'll then need to figure out why IpcGetOperation was failing.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
github.com/go-multierror/multierror served us well.
But we need a few feature from it (implement Is),
and it's not worth maintaining a fork of such a small module.
Instead, I did a clean room implementation inspired by its API.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
Using temporary netlink fork in github.com/tailscale/netlink until we
get the necessary changes upstream in either vishvananda/netlink
or jsimonetti/rtnetlink.
Updates #391
Change-Id: I6e1de96cf0750ccba53dabff670aca0c56dffb7c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Even if not in use. We plan to use it for more stuff later.
(not for iOS or macOS-GUIs yet; only tailscaled)
Change-Id: Idaef719d2a009be6a39f158fd8f57f8cca68e0ee
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
