13a98df rearranged some of this code in a way that broke compilation of
the netstack-only export at github.com/google/netstack because
*_state.go files are not included in that export.
This commit moves resumption logic back into *_state.go, fixing the
compilation breakage.
PiperOrigin-RevId: 263601629
SendMsg before this change would copy all the data over into a
new slice even if the underlying socket could only accept a
small amount of data. This is really inefficient with non-blocking
sockets and under high throughput where large writes could get
ErrWouldBlock or if there was say a timeout associated with the sendmsg()
syscall.
With this change we delay copying bytes in till they are needed and only
copy what can be potentially sent/held in the socket buffer. Reducing
the need to repeatedly copy data over.
Also a minor fix to change state FIN-WAIT-1 when shutdown(..., SHUT_WR) is called
instead of when we transmit the actual FIN. Otherwise the socket could remain in
CONNECTED state even though the user has called shutdown() on the socket.
Updates #627
PiperOrigin-RevId: 263430505
This change just introduces different congestion control states and
ensures the sender.state is updated to reflect the current state
of the connection.
It is not used for any decisions yet but this is required before
algorithms like Eiffel/PRR can be implemented.
Fixes#394
PiperOrigin-RevId: 262638292
Endpoint protocol goroutines were previously started as part of
loading the endpoint. This is potentially too soon, as resources used
by these goroutine may not have been loaded. Protocol goroutines may
perform meaningful work as soon as they're started (ex: incoming
connect) which can cause them to indirectly access resources that
haven't been loaded yet.
This CL defers resuming all protocol goroutines until the end of
restore.
PiperOrigin-RevId: 262409429
This can happen because endpoint.Close() closes the accept channel first and
then drains/resets any accepted but not delivered connections. But there can be
connections that are connected but not delivered to the channel as the channel
was full. But closing the channel can cause these writes to fail with a write to
a closed channel.
The correct solution is to abort any connections in SYN-RCVD state and
drain/abort all completed connections before closing the accept channel.
PiperOrigin-RevId: 261951132
This fixes a bug introduced in cl/251934850 that caused
connect-accept-close-connect races to result in the second connect call
failiing when it should have succeeded.
PiperOrigin-RevId: 259584525
Adds support to set/get the TCP_MAXSEG value but does not
really change the segment sizes emitted by netstack or
alter the MSS advertised by the endpoint. This is currently
being added only to unblock iperf3 on gVisor. Plumbing
this correctly requires a bit more work which will come
in separate CLs.
PiperOrigin-RevId: 257859112
Today we have the logic split in two places between endpoint Read() and the
worker goroutine which actually sends a zero window. This change makes it so
that when a zero window ACK is sent we set a flag in the endpoint which can be
read by the endpoint to decide if it should notify the worker to send a
nonZeroWindow update.
The worker now does not do the check again but instead sends an ACK and flips
the flag right away.
Similarly today when SO_RECVBUF is set the SetSockOpt call has logic
to decide if a zero window update is required. Rather than do that we move
the logic to the worker goroutine and it can check the zeroWindow flag
and send an update if required.
PiperOrigin-RevId: 254505447
The implementation is similar to linux where we track the number of bytes
consumed by the application to grow the receive buffer of a given TCP endpoint.
This ensures that the advertised window grows at a reasonable rate to accomodate
for the sender's rate and prevents large amounts of data being held in stack
buffers if the application is not actively reading or not reading fast enough.
The original paper that was used to implement the linux receive buffer auto-
tuning is available @ https://public.lanl.gov/radiant/pubs/drs/lacsi2001.pdf
NOTE: Linux does not implement DRS as defined in that paper, it's just a good
reference to understand the solution space.
Updates #230
PiperOrigin-RevId: 253168283
This CL also cleans up the error returned for setting congestion
control which was incorrectly returning EINVAL instead of ENOENT.
PiperOrigin-RevId: 252889093
Changes netstack to confirm to current linux behaviour where if the backlog is
full then we drop the SYN and do not send a SYN-ACK. Similarly we allow upto
backlog connections to be in SYN-RCVD state as long as the backlog is not full.
We also now drop a SYN if syn cookies are in use and the backlog for the
listening endpoint is full.
Added new tests to confirm the behaviour.
Also reverted the change to increase the backlog in TcpPortReuseMultiThread
syscall test.
Fixes#236
PiperOrigin-RevId: 252500462
This is necessary for implementing network diagnostic interfaces like
/proc/net/{tcp,udp,unix} and sock_diag(7).
For pass-through endpoints such as hostinet, we obtain the socket
state from the backend. For netstack, we add explicit tracking of TCP
states.
PiperOrigin-RevId: 251934850
In case of GSO, a segment can container more than one packet
and we need to use the pCount() helper to get a number of packets.
PiperOrigin-RevId: 251743020
When checking the length of the acceptedChan we should hold the
endpoint mutex otherwise a syn received while the listening socket
is being closed can result in a data race where the cleanupLocked
routine sets acceptedChan to nil while a handshake goroutine
in progress could try and check it at the same time.
PiperOrigin-RevId: 251537697
Netstack sets the unprocessed segment queue size to match the receive
buffer size. This is not required as this queue only needs to hold enough
for a short duration before the endpoint goroutine can process it.
Updates #230
PiperOrigin-RevId: 250976323
Netstack listen loop can get stuck if cookies are in-use and the app is slow to
accept incoming connections. Further we continue to complete handshake for a
connection even if the backlog is full. This creates a problem when a lots of
connections come in rapidly and we end up with lots of completed connections
just hanging around to be delivered.
These fixes change netstack behaviour to mirror what linux does as described
here in the following article
http://veithen.io/2014/01/01/how-tcp-backlog-works-in-linux.html
Now when cookies are not in-use Netstack will silently drop the ACK to a SYN-ACK
and not complete the handshake if the backlog is full. This will result in the
connection staying in a half-complete state. Eventually the sender will
retransmit the ACK and if backlog has space we will transition to a connected
state and deliver the endpoint.
Similarly when cookies are in use we do not try and create an endpoint unless
there is space in the accept queue to accept the newly created endpoint. If
there is no space then we again silently drop the ACK as we can just recreate it
when the ACK is retransmitted by the peer.
We also now use the backlog to cap the size of the SYN-RCVD queue for a given
endpoint. So at any time there can be N connections in the backlog and N in a
SYN-RCVD state if the application is not accepting connections. Any new SYNs
will be dropped.
This CL also fixes another small bug where we mark a new endpoint which has not
completed handshake as connected. We should wait till handshake successfully
completes before marking it connected.
Updates #236
PiperOrigin-RevId: 250717817
Based on the guidelines at
https://opensource.google.com/docs/releasing/authors/.
1. $ rg -l "Google LLC" | xargs sed -i 's/Google LLC.*/The gVisor Authors./'
2. Manual fixup of "Google Inc" references.
3. Add AUTHORS file. Authors may request to be added to this file.
4. Point netstack AUTHORS to gVisor AUTHORS. Drop CONTRIBUTORS.
Fixes#209
PiperOrigin-RevId: 245823212
Change-Id: I64530b24ad021a7d683137459cafc510f5ee1de9
Support shutdown on only the read side of an endpoint. Reads performed
after a call to Shutdown with only the ShutdownRead flag will return
ErrClosedForReceive without data.
Break out the shutdown(2) with SHUT_RD syscall test into to two tests.
The first tests that no packets are sent when shutting down the read
side of a socket. The second tests that, after shutting down the read
side of a socket, unread data can still be read, or an EOF if there is
no more data to read.
Change-Id: I9d7c0a06937909cbb466b7591544a4bcaebb11ce
PiperOrigin-RevId: 244459430
It is possible to create a listening socket which will accept
IPv4 and IPv6 connections. In this case, we set IPv6ProtocolNumber
for all accepted endpoints, even if they handle IPv4 connections.
This means that we can't use endpoint.netProto to set gso.L3HdrLen.
PiperOrigin-RevId: 244227948
Change-Id: I5e1863596cb9f3d216febacdb7dc75651882eef1
Having raw socket code together will make it easier to add support for other raw
network protocols. Currently, only ICMP uses the raw endpoint. However, adding
support for other protocols such as UDP shouldn't be much more difficult than
adding a few switch cases.
PiperOrigin-RevId: 241564875
Change-Id: I77e03adafe4ce0fd29ba2d5dfdc547d2ae8f25bf
The panic was caused by modifying the tree while iterating which invalidated the
iterator.
Also fixes another bug in SACKScoreboard.Insert() which was causing blocks to be
merged incorrectly.
PiperOrigin-RevId: 240895053
Change-Id: Ia72b8244297962df5c04283346da5226434740af
The linux packet socket can handle GSO packets, so we can segment packets to
64K instead of the MTU which is usually 1500.
Here are numbers for the nginx-1m test:
runsc: 579330.01 [Kbytes/sec] received
runsc-gso: 1794121.66 [Kbytes/sec] received
runc: 2122139.06 [Kbytes/sec] received
and for tcp_benchmark:
$ tcp_benchmark --duration 15 --ideal
[ 4] 0.0-15.0 sec 86647 MBytes 48456 Mbits/sec
$ tcp_benchmark --client --duration 15 --ideal
[ 4] 0.0-15.0 sec 2173 MBytes 1214 Mbits/sec
$ tcp_benchmark --client --duration 15 --ideal --gso 65536
[ 4] 0.0-15.0 sec 19357 MBytes 10825 Mbits/sec
PiperOrigin-RevId: 240809103
Change-Id: I2637f104db28b5d4c64e1e766c610162a195775a
This is a preparation for GSO changes (cl/234508902).
RELNOTES[gofers]: Refactor checksum code to include length, which
it already did, but in a convoluted way. Should be a no-op.
PiperOrigin-RevId: 240460794
Change-Id: I537381bc670b5a9f5d70a87aa3eb7252e8f5ace2
IP_MULTICAST_LOOP controls whether or not multicast packets sent on the default
route are looped back. In order to implement this switch, support for sending
and looping back multicast packets on the default route had to be implemented.
For now we only support IPv4 multicast.
PiperOrigin-RevId: 237534603
Change-Id: I490ac7ff8e8ebef417c7eb049a919c29d156ac1c
Broadly, this change:
* Enables sockets to be created via `socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)`.
* Passes the network-layer (IP) header up the stack to the transport endpoint,
which can pass it up to the socket layer. This allows a raw socket to return
the entire IP packet to users.
* Adds functions to stack.TransportProtocol, stack.Stack, stack.transportDemuxer
that enable incoming packets to be delivered to raw endpoints. New raw sockets
of other protocols (not ICMP) just need to register with the stack.
* Enables ping.endpoint to return IP headers when created via SOCK_RAW.
PiperOrigin-RevId: 235993280
Change-Id: I60ed994f5ff18b2cbd79f063a7fdf15d093d845a
This change does not make use of SACK information but adds support to track
SACK information and store it in the endpoint.
The actual SACK based recovery will be in a separate CL.
Part of commits to add RFC 6675 support to Netstack.
PiperOrigin-RevId: 235612264
Change-Id: I261f94844d7bad5abda803152ce6cc6125a467ff
Tamir Duberstein
Andrei Vagin
Bhasker Hariharan
Rahat Mahmood
Kevin Krakauer
gVisor bot
Adin Scannell
Googler
Michael Pratt
Nicolas Lacasse
Ben Burkert
Ian Gudger