Commit Graph

185 Commits (b9ecc50ce38d23cfacd5fae6360fa9742c0564a6)

Author SHA1 Message Date
Brad Fitzpatrick 634cc2ba4a wgengine/netstack: remove unused taildrive deps
A filesystem was plumbed into netstack in 993acf4475
but hasn't been used since 2d5d6f5403. Remove it.

Noticed while rebasing a Tailscale fork elsewhere.

Updates tailscale/corp#16827

Change-Id: Ib76deeda205ffe912b77a59b9d22853ebff42813
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 weeks ago
Brad Fitzpatrick c763b7a7db syncs: delete Map.Range, update callers to iterators
Updates #11038

Change-Id: I2819fed896cc4035aba5e4e141b52c12637373b1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
1 month ago
Brad Fitzpatrick 5f88b65764 wgengine/netstack: check userspace ping success on Windows
Hacky temporary workaround until we do #13654 correctly.

Updates #13654

Change-Id: I764eaedbb112fb3a34dddb89572fec1b2543fd4a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 months ago
Kristoffer Dalby 0e0e53d3b3 util/usermetrics: make usermetrics non-global
this commit changes usermetrics to be non-global, this is a building
block for correct metrics if a go process runs multiple tsnets or
in tests.

Updates #13420
Updates tailscale/corp#22075

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2 months ago
Brad Fitzpatrick 9f9470fc10 ipnlocal,proxymap,wgengine/netstack: add optional WhoIs/proxymap debug
Updates tailscale/corp#20600

Change-Id: I2bb17af0f40603ada1ba4cecc087443e00f9392a
Co-authored-by: Maisem Ali <maisem@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 months ago
Jordan Whited 0926954cf5
net/tstun,wgengine/netstack: implement TCP GRO for local services (#13315)
Throughput improves substantially when measured via netstack loopback
(TS_DEBUG_NETSTACK_LOOPBACK_PORT).

Before (d21ebc2):
jwhited@i5-12400-2:~$ iperf3 -V -c 100.100.100.100
Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  5.77 GBytes  4.95 Gbits/sec    0 sender
[  5]   0.00-10.01  sec  5.77 GBytes  4.95 Gbits/sec      receiver

After:
jwhited@i5-12400-2:~$ iperf3 -V -c 100.100.100.100
Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  12.7 GBytes  10.9 Gbits/sec    0 sender
[  5]   0.00-10.00  sec  12.7 GBytes  10.9 Gbits/sec      receiver

Updates tailscale/corp#22754

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited d21ebc28af
wgengine/netstack: implement netstack loopback (#13301)
When the TS_DEBUG_NETSTACK_LOOPBACK_PORT environment variable is set,
netstack will loop back (dnat to addressFamilyLoopback:loopbackPort)
TCP & UDP flows originally destined to localServicesIP:loopbackPort.
localServicesIP is quad-100 or the IPv6 equivalent.

Updates tailscale/corp#22713

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited 31cdbd68b1
net/tstun: fix gvisor inbound GSO packet injection (#13283)
buffs[0] was not sized to hold pkt with GSO, resulting in a panic.

Updates tailscale/corp#22511

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited bfcb3562e6
wgengine/netstack: re-enable gVisor GSO on Linux (#13269)
This was previously disabled in 8e42510 due to missing GSO-awareness in
tstun, which was resolved in d097096.

Updates tailscale/corp#22511

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited d097096ddc
net/tstun,wgengine/netstack: make inbound synthetic packet injection GSO-aware (#13266)
Updates tailscale/corp#22511

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited 6d4973e1e0
wgengine/netstack: use types/logger.Logf instead of stdlib log.Printf (#13267)
Updates #cleanup

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited 8e42510a71
wgengine/netstack: disable gVisor GSO on Linux (#13215)
net/tstun.Wrapper.InjectInboundPacketBuffer is not GSO-aware, which can
break quad-100 TCP streams as a result. Linux is the only platform where
gVisor GSO was previously enabled.

Updates tailscale/corp#22511
Updates #13211

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited 7675c3ebf2
wgengine/netstack/gro: exclude importation of gVisor GRO pkg on iOS (#13202)
In df6014f1d7 we removed build tag
gating preventing importation, which tripped a NetworkExtension limit
test in corp. This was a reversal of
25f0a3fc8f which actually made the
situation worse, hence the simplification.

This commit goes back to the strategy in
25f0a3fc8f, and gets us back under the
limit in my local testing. Admittedly, we don't fully understand
the effects of importing or excluding importation of this package,
and have seen mixed results, but this commit allows us to move forward
again.

Updates tailscale/corp#22125

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited df6014f1d7
net/tstun,wgengine{/netstack/gro}: refactor and re-enable gVisor GRO for Linux (#13172)
In 2f27319baf we disabled GRO due to a
data race around concurrent calls to tstun.Wrapper.Write(). This commit
refactors GRO to be thread-safe, and re-enables it on Linux.

This refactor now carries a GRO type across tstun and netstack APIs
with a lifetime that is scoped to a single tstun.Wrapper.Write() call.

In 25f0a3fc8f we used build tags to
prevent importation of gVisor's GRO package on iOS as at the time we
believed it was contributing to additional memory usage on that
platform. It wasn't, so this commit simplifies and removes those
build tags.

Updates tailscale/corp#22353
Updates tailscale/corp#22125
Updates #6816

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited 2f27319baf
wgengine/netstack: disable gVisor TCP GRO for Linux (#13138)
A SIGSEGV was observed around packet merging logic in gVisor's GRO
package.

Updates tailscale/corp#22353

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited 25f0a3fc8f
wgengine/netstack: use build tags to exclude gVisor GRO importation on iOS (#13015)
Updates tailscale/corp#22125

Signed-off-by: Jordan Whited <jordan@tailscale.com>
4 months ago
Jordan Whited d9d9d525d9
wgengine/netstack: increase gVisor's TCP send and receive buffer sizes (#12994)
This commit increases gVisor's TCP max send (4->6MiB) and receive
(4->8MiB) buffer sizes on all platforms except iOS. These values are
biased towards higher throughput on high bandwidth-delay product paths.

The iperf3 results below demonstrate the effect of this commit between
two Linux computers with i5-12400 CPUs. 100ms of RTT latency is
introduced via Linux's traffic control network emulator queue
discipline.

The first set of results are from commit f0230ce prior to TCP buffer
resizing.

gVisor write direction:
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   180 MBytes   151 Mbits/sec    0  sender
[  5]   0.00-10.10  sec   179 MBytes   149 Mbits/sec       receiver

gVisor read direction:
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.10  sec   337 MBytes   280 Mbits/sec   20 sender
[  5]   0.00-10.00  sec   323 MBytes   271 Mbits/sec         receiver

The second set of results are from this commit with increased TCP
buffer sizes.

gVisor write direction:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec   297 MBytes   249 Mbits/sec    0 sender
[  5]   0.00-10.10  sec   297 MBytes   247 Mbits/sec        receiver

gVisor read direction:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.10  sec   501 MBytes   416 Mbits/sec   17  sender
[  5]   0.00-10.00  sec   485 MBytes   407 Mbits/sec       receiver

Updates #9707
Updates tailscale/corp#22119

Signed-off-by: Jordan Whited <jordan@tailscale.com>
4 months ago
Jordan Whited f0230ce0b5
go.mod,net/tstun,wgengine/netstack: implement gVisor TCP GRO for Linux (#12921)
This commit implements TCP GRO for packets being written to gVisor on
Linux. Windows support will follow later. The wireguard-go dependency is
updated in order to make use of newly exported IP checksum functions.
gVisor is updated in order to make use of newly exported
stack.PacketBuffer GRO logic.

TCP throughput towards gVisor, i.e. TUN write direction, is dramatically
improved as a result of this commit. Benchmarks show substantial
improvement, sometimes as high as 2x. High bandwidth-delay product
paths remain receive window limited, bottlenecked by gVisor's default
TCP receive socket buffer size. This will be addressed in a  follow-on
commit.

The iperf3 results below demonstrate the effect of this commit between
two Linux computers with i5-12400 CPUs. There is roughly ~13us of round
trip latency between them.

The first result is from commit 57856fc without TCP GRO.

Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  4.77 GBytes  4.10 Gbits/sec   20 sender
[  5]   0.00-10.00  sec  4.77 GBytes  4.10 Gbits/sec      receiver

The second result is from this commit with TCP GRO.

Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  10.6 GBytes  9.14 Gbits/sec   20 sender
[  5]   0.00-10.00  sec  10.6 GBytes  9.14 Gbits/sec      receiver

Updates #6816

Signed-off-by: Jordan Whited <jordan@tailscale.com>
4 months ago
Jordan Whited 7bc2ddaedc
go.mod,net/tstun,wgengine/netstack: implement gVisor TCP GSO for Linux (#12869)
This commit implements TCP GSO for packets being read from gVisor on
Linux. Windows support will follow later. The wireguard-go dependency is
updated in order to make use of newly exported GSO logic from its tun
package.

A new gVisor stack.LinkEndpoint implementation has been established
(linkEndpoint) that is loosely modeled after its predecessor
(channel.Endpoint). This new implementation supports GSO of monster TCP
segments up to 64K in size, whereas channel.Endpoint only supports up to
32K. linkEndpoint will also be required for GRO, which will be
implemented in a follow-on commit.

TCP throughput from gVisor, i.e. TUN read direction, is dramatically
improved as a result of this commit. Benchmarks show substantial
improvement through a wide range of RTT and loss conditions, sometimes
as high as 5x.

The iperf3 results below demonstrate the effect of this commit between
two Linux computers with i5-12400 CPUs. There is roughly ~13us of round
trip latency between them.

The first result is from commit 57856fc without TCP GSO.

Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  2.51 GBytes  2.15 Gbits/sec  154 sender
[  5]   0.00-10.00  sec  2.49 GBytes  2.14 Gbits/sec      receiver

The second result is from this commit with TCP GSO.

Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  12.6 GBytes  10.8 Gbits/sec    6 sender
[  5]   0.00-10.00  sec  12.6 GBytes  10.8 Gbits/sec      receiver

Updates #6816

Signed-off-by: Jordan Whited <jordan@tailscale.com>
4 months ago
Brad Fitzpatrick cf97cff33b wgengine/netstack: simplify netaddrIPFromNetstackIP
Updates #cleanup

Change-Id: I66878b08a75d44170460cbf33c895277c187bd8d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 months ago
Andrew Dunham 45d2f4301f proxymap, various: distinguish between different protocols
Previously, we were registering TCP and UDP connections in the same map,
which could result in erroneously removing a mapping if one of the two
connections completes while the other one is still active.

Add a "proto string" argument to these functions to avoid this.
Additionally, take the "proto" argument in LocalAPI, and plumb that
through from the CLI and add a new LocalClient method.

Updates tailscale/corp#20600

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I35d5efaefdfbf4721e315b8ca123f0c8af9125fb
5 months ago
Brad Fitzpatrick 86e0f9b912 net/ipset, wgengine/filter/filtertype: add split-out packages
This moves NewContainsIPFunc from tsaddr to new ipset package.

And wgengine/filter types gets split into wgengine/filter/filtertype,
so netmap (and thus the CLI, etc) doesn't need to bring in ipset,
bart, etc.

Then add a test making sure the CLI deps don't regress.

Updates #1278

Change-Id: Ia246d6d9502bbefbdeacc4aef1bed9c8b24f54d5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 months ago
Andrew Dunham 72c8f7700b wgengine/netstack: add test for #12448
This refactors the logic for determining whether a packet should be sent
to the host or not into a function, and then adds tests for it.

Updates #11304
Updates #12448

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ief9afa98eaffae00e21ceb7db073c61b170355e5
5 months ago
Irbe Krumina 88f2d234a4
wgengine/netstack: fix 4via6 subnet routes (#12454)
Fix a bug where, for a subnet router that advertizes
4via6 route, all packets with a source IP matching
the 4via6 address were being sent to the host itself.
Instead, only send to host packets whose destination
address is host's local address.

Fixes tailscale/tailscale#12448

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
Co-authored-by: Andrew Dunham <andrew@du.nham.ca>
5 months ago
Andrew Dunham e88a5dbc92 various: fix lint warnings
Some lint warnings caught by running 'make lint' locally.

Updates #cleanup

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I1534ed6f2f5e1eb029658906f9d62607dad98ca3
6 months ago
Maisem Ali 42cfbf427c tsnet,wgengine/netstack: add ListenPacket and tests
This adds a new ListenPacket function on tsnet.Server
which acts mostly like `net.ListenPacket`.

Unlike `Server.Listen`, this requires listening on a
specific IP and does not automatically listen on both
V4 and V6 addresses of the Server when the IP is unspecified.

To test this, it also adds UDP support to tsdial.Dialer.UserDial
and plumbs it through the localapi. Then an associated test
to make sure the UDP functionality works from both sides.

Updates #12182

Signed-off-by: Maisem Ali <maisem@tailscale.com>
6 months ago
Andrea Gottardo e5f67f90a2
xcode: allow ICMP ping relay on macOS + iOS platforms (#12048)
Fixes tailscale/tailscale#10393
Fixes tailscale/corp#15412
Fixes tailscale/corp#19808

On Apple platforms, exit nodes and subnet routers have been unable to relay pings from Tailscale devices to non-Tailscale devices due to sandbox restrictions imposed on our network extensions by Apple. The sandbox prevented the code in netstack.go from spawning the `ping` process which we were using.

Replace that exec call with logic to send an ICMP echo request directly, which appears to work in userspace, and not trigger a sandbox violation in the syslog.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
6 months ago
Andrew Dunham 8f7f9ac17e wgengine/netstack: handle 4via6 routes that are advertised by the same node
Previously, a node that was advertising a 4via6 route wouldn't be able
to make use of that same route; the packet would be delivered to
Tailscale, but since we weren't accepting it in handleLocalPackets, the
packet wouldn't be delivered to netstack and would never hit the 4via6
logic. Let's add that support so that usage of 4via6 is consistent
regardless of where the connection is initiated from.

Updates #11304

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ic28dc2e58080d76100d73b93360f4698605af7cb
7 months ago
Brad Fitzpatrick 21509db121 ipn/ipnlocal, all: plumb health trackers in tests
I saw some panics in CI, like:

    2024-05-08T04:30:25.9553518Z ## WARNING: (non-fatal) nil health.Tracker (being strict in CI):
    2024-05-08T04:30:25.9554043Z goroutine 801 [running]:
    2024-05-08T04:30:25.9554489Z tailscale.com/health.(*Tracker).nil(0x0)
    2024-05-08T04:30:25.9555086Z 	tailscale.com/health/health.go:185 +0x70
    2024-05-08T04:30:25.9555688Z tailscale.com/health.(*Tracker).SetUDP4Unbound(0x0, 0x0)
    2024-05-08T04:30:25.9556373Z 	tailscale.com/health/health.go:532 +0x2f
    2024-05-08T04:30:25.9557296Z tailscale.com/wgengine/magicsock.(*Conn).bindSocket(0xc0003b4808, 0xc0003b4878, {0x1fbca53, 0x4}, 0x0)
    2024-05-08T04:30:25.9558301Z 	tailscale.com/wgengine/magicsock/magicsock.go:2481 +0x12c5
    2024-05-08T04:30:25.9559026Z tailscale.com/wgengine/magicsock.(*Conn).rebind(0xc0003b4808, 0x0)
    2024-05-08T04:30:25.9559874Z 	tailscale.com/wgengine/magicsock/magicsock.go:2510 +0x16f
    2024-05-08T04:30:25.9561038Z tailscale.com/wgengine/magicsock.NewConn({0xc000063c80, 0x0, 0xc000197930, 0xc000197950, 0xc000197960, {0x0, 0x0}, 0xc000197970, 0xc000198ee0, 0x0, ...})
    2024-05-08T04:30:25.9562402Z 	tailscale.com/wgengine/magicsock/magicsock.go:476 +0xd5f
    2024-05-08T04:30:25.9563779Z tailscale.com/wgengine.NewUserspaceEngine(0xc000063c80, {{0x22c8750, 0xc0001976b0}, 0x0, {0x22c3210, 0xc000063c80}, {0x22c31d8, 0x2d3c900}, 0x0, 0x0, ...})
    2024-05-08T04:30:25.9564982Z 	tailscale.com/wgengine/userspace.go:389 +0x159d
    2024-05-08T04:30:25.9565529Z tailscale.com/ipn/ipnlocal.newTestBackend(0xc000358b60)
    2024-05-08T04:30:25.9566086Z 	tailscale.com/ipn/ipnlocal/serve_test.go:675 +0x2a5
    2024-05-08T04:30:25.9566612Z ta

Updates #11874

Change-Id: I3432ed52d670743e532be4642f38dbd6e3763b1b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick 7c1d6e35a5 all: use Go 1.22 range-over-int
Updates #11058

Change-Id: I35e7ef9b90e83cac04ca93fd964ad00ed5b48430
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick dd6c76ea24 ipn: remove unused Options.LegacyMigrationPrefs
I'm on a mission to simplify LocalBackend.Start and its locking
and deflake some tests.

I noticed this hasn't been used since March 2023 when it was removed
from the Windows client in corp 66be796d33c.

So, delete.

Updates #11649

Change-Id: I40f2cb75fb3f43baf23558007655f65a8ec5e1b2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Maisem Ali 3f4c5daa15 wgengine/netstack: remove SubnetRouterWrapper
It was used when we only supported subnet routers on linux
and would nil out the SubnetRoutes slice as no other router
worked with it, but now we support subnet routers on ~all platforms.

The field it was setting to nil is now only used for network logging
and nowhere else, so keep the field but drop the SubnetRouterWrapper
as it's not useful.

Updates #cleanup

Change-Id: Id03f9b6ec33e47ad643e7b66e07911945f25db79
Signed-off-by: Maisem Ali <maisem@tailscale.com>
8 months ago
Charlotte Brandhorst-Satzkorn 93618a3518
tailscale: update tailfs functions and vars to use drive naming (#11597)
This change updates all tailfs functions and the majority of the tailfs
variables to use the new drive naming.

Updates tailscale/corp#16827

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
8 months ago
Charlotte Brandhorst-Satzkorn 14683371ee
tailscale: update tailfs file and package names (#11590)
This change updates the tailfs file and package names to their new
naming convention.

Updates #tailscale/corp#16827

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
8 months ago
Andrew Dunham 7429e8912a wgengine/netstack: fix bug with duplicate SYN packets in client limit
This fixes a bug that was introduced in #11258 where the handling of the
per-client limit didn't properly account for the fact that the gVisor
TCP forwarder will return 'true' to indicate that it's handled a
duplicate SYN packet, but not launch the handler goroutine.

In such a case, we neither decremented our per-client limit in the
wrapper function, nor did we do so in the handler function, leading to
our per-client limit table slowly filling up without bound.

Fix this by doing the same duplicate-tracking logic that the TCP
forwarder does so we can detect such cases and appropriately decrement
our in-flight counter.

Updates tailscale/corp#12184

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ib6011a71d382a10d68c0802593f34b8153d06892
9 months ago
Andrew Dunham 62cf83eb92 go.mod: bump gvisor
The `stack.PacketBufferPtr` type no longer exists; replace it with
`*stack.PacketBuffer` instead.

Updates #8043

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ib56ceff09166a042aa3d9b80f50b2aa2d34b3683
9 months ago
Percy Wegmann 2d5d6f5403 ipn,wgengine: only intercept TailFS traffic on quad 100
This fixes a regression introduced with 993acf4 and released in
v1.60.0.

The regression caused us to intercept all userspace traffic to port
8080 which prevented users from exposing their own services to their
tailnet at port 8080.

Now, we only intercept traffic to port 8080 if it's bound for
100.100.100.100 or fd7a:115c:a1e0::53.

Fixes #11283

Signed-off-by: Percy Wegmann <percy@tailscale.com>
(cherry picked from commit 17cd0626f3)
9 months ago
Andrew Dunham 3dd8ae2f26 net/tstun: fix spelling of "WireGuard"
Updates #cleanup

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ida7e30f4689bc18f5f7502f53a0adb5ac3c7981a
9 months ago
Andrew Dunham c5abbcd4b4 wgengine/netstack: add a per-client limit for in-flight TCP forwards
This is a fun one. Right now, when a client is connecting through a
subnet router, here's roughly what happens:

1. The client initiates a connection to an IP address behind a subnet
   router, and sends a TCP SYN
2. The subnet router gets the SYN packet from netstack, and after
   running through acceptTCP, starts DialContext-ing the destination IP,
   without accepting the connection¹
3. The client retransmits the SYN packet a few times while the dial is
   in progress, until either...
4. The subnet router successfully establishes a connection to the
   destination IP and sends the SYN-ACK back to the client, or...
5. The subnet router times out and sends a RST to the client.
6. If the connection was successful, the client ACKs the SYN-ACK it
   received, and traffic starts flowing

As a result, the notification code in forwardTCP never notices when a
new connection attempt is aborted, and it will wait until either the
connection is established, or until the OS-level connection timeout is
reached and it aborts.

To mitigate this, add a per-client limit on how many in-flight TCP
forwarding connections can be in-progress; after this, clients will see
a similar behaviour to the global limit, where new connection attempts
are aborted instead of waiting. This prevents a single misbehaving
client from blocking all other clients of a subnet router by ensuring
that it doesn't starve the global limiter.

Also, bump the global limit again to a higher value.

¹ We can't accept the connection before establishing a connection to the
remote server since otherwise we'd be opening the connection and then
immediately closing it, which breaks a bunch of stuff; see #5503 for
more details.

Updates tailscale/corp#12184

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I76e7008ddd497303d75d473f534e32309c8a5144
9 months ago
Anton Tolchanov cd9cf93de6 wgengine/netstack: expose TCP forwarder drops via clientmetrics
- add a clientmetric with a counter of TCP forwarder drops due to the
  max attempts;
- fix varz metric types, as they are all counters.

Updates #8210

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
9 months ago
Brad Fitzpatrick e1bd7488d0 all: remove LenIter, use Go 1.22 range-over-int instead
Updates #11058
Updates golang/go#65685

Change-Id: Ibb216b346e511d486271ab3d84e4546c521e4e22
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
9 months ago
Percy Wegmann c42a4e407a tailfs: listen for local clients only on 100.100.100.100
FileSystemForLocal was listening on the node's Tailscale address,
which potentially exposes the user's view of TailFS shares to other
Tailnet users. Remote nodes should connect to exported shares via
the peerapi.

This removes that code so that FileSystemForLocal is only avaialable
on 100.100.100.100:8080.

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
9 months ago
Percy Wegmann ddcffaef7a tailfs: disable TailFSForLocal via policy
Adds support for node attribute tailfs:access. If this attribute is
not present, Tailscale will not accept connections to the local TailFS
server at 100.100.100.100:8080.

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
10 months ago
Percy Wegmann abab0d4197 tailfs: clean up naming and package structure
- Restyles tailfs -> tailFS
- Defines interfaces for main TailFS types
- Moves implemenatation of TailFS into tailfsimpl package

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
10 months ago
Percy Wegmann 993acf4475 tailfs: initial implementation
Add a WebDAV-based folder sharing mechanism that is exposed to local clients at
100.100.100.100:8080 and to remote peers via a new peerapi endpoint at
/v0/tailfs.

Add the ability to manage folder sharing via the new 'share' CLI sub-command.

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
10 months ago
James Tucker 7e3bcd297e go.mod,wgengine/netstack: bump gvisor
Updates #8043

Signed-off-by: James Tucker <james@tailscale.com>
10 months ago
Andrew Dunham 7a0392a8a3 wgengine/netstack: expose gVisor metrics through expvar
When tailscaled is run with "-debug 127.0.0.1:12345", these metrics are
available at:
    http://localhost:12345/debug/metrics

Updates #8210

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I19db6c445ac1f8344df2bc1066a3d9c9030606f8
10 months ago
Jordan Whited 5e861c3871
wgengine/netstack: disable RACK on Windows (#10402)
Updates #9707

Signed-off-by: Jordan Whited <jordan@tailscale.com>
1 year ago
Maisem Ali d0f2c0664b wgengine/netstack: standardize var names in UpdateNetstackIPs
Updates #cleanup

Signed-off-by: Maisem Ali <maisem@tailscale.com>
1 year ago
Maisem Ali eaf8aa63fc wgengine/netstack: remove unnecessary map in UpdateNetstackIPs
Updates #cleanup

Signed-off-by: Maisem Ali <maisem@tailscale.com>
1 year ago