This also allows the tee(2) implementation to be enabled, since dup can now be
properly supported via WriteTo.
Note that this change necessitated some minor restructoring with the
fs.FileOperations splice methods. If the *fs.File is passed through directly,
then only public API methods are accessible, which will deadlock immediately
since the locking is already done by fs.Splice. Instead, we pass through an
abstract io.Reader or io.Writer, which elide locks and use the underlying
fs.FileOperations directly.
PiperOrigin-RevId: 268805207
Fix a bug where udp.(*endpoint).Disconnect [accessible in gVisor via
epsocket.(*SocketOperations).Connect with AF_UNSPEC] would leak a port
reservation if the socket/endpoint had an ephemeral port assigned to it.
glibc's getaddrinfo uses connect with AF_UNSPEC, causing each call of
getaddrinfo to leak a port. Call getaddrinfo too many times and you run out of
ports (shows up as connect returning EAGAIN and getaddrinfo returning
EAI_NONAME "Name or service not known").
PiperOrigin-RevId: 268071160
There are a few cases addressed by this change
- We no longer generate a RST in response to a RST packet.
- When we receive a RST we cleanup and release all reservations immediately as
the connection is now aborted.
- An ACK received by a listening socket generates a RST when SYN cookies are not
in-use. The only reason an ACK should land at the listening socket is if we
are using SYN cookies otherwise the goroutine for the handshake in progress
should have gotten the packet and it should never have arrived at the
listening endpoint.
- Also fixes the error returned when a connection times out due to a
Keepalive timer expiration from ECONNRESET to a ETIMEDOUT.
PiperOrigin-RevId: 267238427
Adds support to generate Port Unreachable messages for UDP
datagrams received on a port for which there is no valid
endpoint.
Fixes#703
PiperOrigin-RevId: 267034418
Add missing state transition to LastAck, which should happen when the
endpoint has already recieved a FIN from the remote side, and is
sending its own FIN.
PiperOrigin-RevId: 265568314
This fixes the issue of not being able to bind to either a multicast or
broadcast address as well as to send and receive data from it. The way to solve
this is to treat these addresses similar to the ANY address and register their
transport endpoint ID with the global stack's demuxer rather than the NIC's.
That way there is no need to require an endpoint with that multicast or
broadcast address. The stack's demuxer is in fact the only correct one to use,
because neither broadcast- nor multicast-bound sockets care which NIC a
packet was received on (for multicast a join is still needed to receive packets
on a NIC).
I also took the liberty of refactoring udp_test.go to consolidate a lot of
duplicate code and make it easier to create repetitive tests that test the same
feature for a variety of packet and socket types. For this purpose I created a
"flowType" that represents two things: 1) the type of packet being sent or
received and 2) the type of socket used for the test. E.g., a "multicastV4in6"
flow represents a V4-mapped multicast packet run through a V6-dual socket.
This allows writing significantly simpler tests. A nice example is testTTL().
PiperOrigin-RevId: 264766909
These errors are always pointers; there's no sense in dereferencing them
in the panic call. Changed one false positive for clarity.
PiperOrigin-RevId: 263611579
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 doesn't currently pass on gVisor.
While I'm here, fix a bug where connecting to the v6-mapped v4 address doesn't
work in gVisor.
PiperOrigin-RevId: 260923961
This allows the user code to add a network address with a subnet prefix length.
The prefix length value is stored in the network endpoint and provided back to
the user in the ProtocolAddress type.
PiperOrigin-RevId: 259807693
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
iptables also relies on IPPROTO_RAW in a way. It opens such a socket to
manipulate the kernel's tables, but it doesn't actually use any of the
functionality. Blegh.
PiperOrigin-RevId: 257903078
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
Addresses obvious typos, in the documentation only.
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/gvisor/pull/443 from Pixep:fix/documentation-spelling 4d0688164eafaf0b3010e5f4824b35d1e7176d65
PiperOrigin-RevId: 255477779
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
These wakers are uselessly allocated and passed around; nothing ever
listens for notifications on them. The code here appears to be
vestigial, so removing it and allowing a nil waker to be passed seems
appropriate.
PiperOrigin-RevId: 249879320
Change-Id: Icd209fb77cc0dd4e5c49d7a9f2adc32bf88b4b71
And stop storing the Filesystem in the MountSource.
This allows us to decouple the MountSource filesystem type from the name of the
filesystem.
PiperOrigin-RevId: 247292982
Change-Id: I49cbcce3c17883b7aa918ba76203dfd6d1b03cc8
gVisor bot
Kevin Krakauer
Andrei Vagin
Adin Scannell
Michael Pratt
Ian Gudger
Bhasker Hariharan
Rahat Mahmood
Chris Kuiper
Tamir Duberstein
Nicolas Lacasse