Implement UDP GSO and GRO for the Linux tun.Device, which is made
possible by virtio extensions in the kernel's TUN driver starting in
v6.2.
secnetperf, a QUIC benchmark utility from microsoft/msquic@8e1eb1a, is
used to demonstrate the effect of this commit between two Linux
computers with i5-12400 CPUs. There is roughly ~13us of round trip
latency between them. secnetperf was invoked with the following command
line options:
-stats:1 -exec:maxtput -test:tput -download:10000 -timed:1 -encrypt:0
The first result is from commit 2e0774f without UDP GSO/GRO on the TUN.
[conn][0x55739a144980] STATS: EcnCapable=0 RTT=3973 us
SendTotalPackets=55859 SendSuspectedLostPackets=61
SendSpuriousLostPackets=59 SendCongestionCount=27
SendEcnCongestionCount=0 RecvTotalPackets=2779122
RecvReorderedPackets=0 RecvDroppedPackets=0
RecvDuplicatePackets=0 RecvDecryptionFailures=0
Result: 3654977571 bytes @ 2922821 kbps (10003.972 ms).
The second result is with UDP GSO/GRO on the TUN.
[conn][0x56493dfd09a0] STATS: EcnCapable=0 RTT=1216 us
SendTotalPackets=165033 SendSuspectedLostPackets=64
SendSpuriousLostPackets=61 SendCongestionCount=53
SendEcnCongestionCount=0 RecvTotalPackets=11845268
RecvReorderedPackets=25267 RecvDroppedPackets=0
RecvDuplicatePackets=0 RecvDecryptionFailures=0
Result: 15574671184 bytes @ 12458214 kbps (10001.222 ms).
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
There's not really a use at the moment for making this configurable, and
once bind_windows.go behaves like bind_std.go, we'll be able to use
constants everywhere. So begin that simplification now.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Implement TCP offloading via TSO and GRO for the Linux tun.Device, which
is made possible by virtio extensions in the kernel's TUN driver.
Delete conn.LinuxSocketEndpoint in favor of a collapsed conn.StdNetBind.
conn.StdNetBind makes use of recvmmsg() and sendmmsg() on Linux. All
platforms now fall under conn.StdNetBind, except for Windows, which
remains in conn.WinRingBind, which still needs to be adjusted to handle
multiple packets.
Also refactor sticky sockets support to eventually be applicable on
platforms other than just Linux. However Linux remains the sole platform
that fully implements it for now.
Co-authored-by: James Tucker <james@tailscale.com>
Signed-off-by: James Tucker <james@tailscale.com>
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Accept packet vectors for reading and writing in the tun.Device and
conn.Bind interfaces, so that the internal plumbing between these
interfaces now passes a vector of packets. Vectors move untouched
between these interfaces, i.e. if 128 packets are received from
conn.Bind.Read(), 128 packets are passed to tun.Device.Write(). There is
no internal buffering.
Currently, existing implementations are only adjusted to have vectors
of length one. Subsequent patches will improve that.
Also, as a related fixup, use the unix and windows packages rather than
the syscall package when possible.
Co-authored-by: James Tucker <james@tailscale.com>
Signed-off-by: James Tucker <james@tailscale.com>
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Use unix.ByteSliceToString in (*NativeTun).nameSlice to convert the
TUNGETIFF ioctl result []byte to a string.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
At these points, the socket file descriptor is not yet wrapped in an
*os.File, so it needs to be closed explicitly on error.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
On Linux we can run `ip link del wg0`, in which case the fd becomes
stale, and we should exit. Since this is an intentional action, don't
treat it as an error.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
It was just returning "no such file or directory" (the String of the
syscall.Errno returned by CreateTUN).
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This works around a startup race condition when competing with
HackListener, which is trying to do the same job. If HackListener
detects that the tundev is running while there is still an event in the
netlink queue that says it isn't running, then the device receives a
string of events like
EventUp (HackListener)
EventDown (NetlinkListener)
EventUp (NetlinkListener)
Unfortunately, after the first EventDown, the device stops itself,
thinking incorrectly that the administrator has downed its tundev.
The device is ignoring the initial EventDown anyway, so just don't emit
it.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
Update the golang.org/x/sys/unix dependency and use the newly introduced
RTMGRP_* consts instead of using the corresponding RTNLGRP_* const to
create a mask.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
