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
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
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 option allows multiple sockets to be bound to the same port.
Incoming packets are distributed to sockets using a hash based on source and
destination addresses. This means that all packets from one sender will be
received by the same server socket.
PiperOrigin-RevId: 227153413
Change-Id: I59b6edda9c2209d5b8968671e9129adb675920cf
So that when saving TCP endpoint in these states, there is no pending or
background activities.
Also lift tcp network save rejection error to tcpip package.
PiperOrigin-RevId: 199370748
Change-Id: Ief7b45c2a7338d12414cd7c23db95de6a9c22700
So that when saving TCP endpoint in these states, there is no pending or
background activities.
Also lift tcp network save rejection error to tcpip package.
PiperOrigin-RevId: 196886839
Change-Id: I0fe73750f2743ec7e62d139eb2cec758c5dd6698