The limits for snd/rcv buffers for unix domain socket is controlled by the
following sysctls on linux
- net.core.rmem_default
- net.core.rmem_max
- net.core.wmem_default
- net.core.wmem_max
Today in gVisor we do not expose these sysctls but we do support setting the
equivalent in netstack via stack.Options() method. But AF_UNIX sockets in gVisor
can be used without netstack, with hostinet or even without any networking stack
at all. Which means ideally these sysctls need to live as globals in gVisor.
But rather than make this a big change for now we hardcode the limits in the
AF_UNIX implementation itself (which in itself is better than where we were
before) where it SO_SNDBUF was hardcoded to 16KiB. Further we bump the initial
limit to a default value of 208 KiB to match linux from the paltry 16 KiB we use
today.
Updates #5132
PiperOrigin-RevId: 356665498
The SO_ACCEPTCONN option is used only on getsockopt(). When this option is
specified, getsockopt() indicates whether socket listening is enabled for
the socket. A value of zero indicates that socket listening is disabled;
non-zero that it is enabled.
PiperOrigin-RevId: 338703206
SO_LINGER is a socket level option and should be stored on all endpoints even
though it is used to linger only for TCP endpoints.
PiperOrigin-RevId: 332369252
For SOCK_STREAM type unix socket, we shall return ECONNRESET if peer is
closed with data not read.
We explictly set a flag when closing one end, to differentiate from
just shutdown (where zero shall be returned).
Fixes: #735
Signed-off-by: Jianfeng Tan <[email protected]>
Previously, recvmsg() on a unix stream socket with its peer closed will
never return, with goroutine call trace like this:
...
2 in gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).block
at pkg/sentry/kernel/task_block.go:124
3 in gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).BlockWithDeadline
at pkg/sentry/kernel/task_block.go:69
4 in gvisor.dev/gvisor/pkg/sentry/socket/unix.(*SocketOperations).RecvMsg
at pkg/sentry/socket/unix/unix.go:612
5 in gvisor.dev/gvisor/pkg/sentry/syscalls/linux.recvFrom
at pkg/sentry/syscalls/linux/sys_socket.go:885
6 in gvisor.dev/gvisor/pkg/sentry/syscalls/linux.RecvFrom
at pkg/sentry/syscalls/linux/sys_socket.go:910
...
The issue is caused by that ErrClosedForReceive returned by
unix/transport.queue is turned into nil in
unix.(*EndpointReader).ReadToBlocks():
err.ToError()
As a result, in unix.(*SocketOperations).RecvMsg():
n == 0 and err == nil
We shall differentiate it from another case - no data to read where
ErrWouldBlock shall be returned; and return 0 immediately.
Fixes: #734
Reported-by: chenglang.hy <[email protected]>
Signed-off-by: Jianfeng Tan <[email protected]>
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 implementation of O_CLOEXEC is orthogonal to every property tested
by these tests; removing it significantly reduces the number of
redundant tests we run.
Also remove no-op calls to VecCat (calls with a single argument).
PiperOrigin-RevId: 230959537
Change-Id: I83fe7db24e481ef67ca1f1992228af423f640b5c
