vsock: add DialTimeout

[BetaXOi]

We need to use Dial with timeout feature in Kata, see kata-containers/runtime#1917 (comment)

Signed-off-by: Ning Bo ning.bo9@zte.com.cn

[mdlayher]

Thanks for this! The Go stable CI failure appears to be related to an outdated dependency so I've pushed a new commit. Could you please rebase on master?

In addition, if possible, I would love to see a test with a very short dial timeout to verify that the applied timeout parameter does take effect.

[BetaXOi]

OK, i will try to add a new test case for timeout

[BetaXOi]

I have rebased and add a test for timeout.
But the test case has some problems:

1. The effective minimum timeout is DIV_ROUND_UP (tv.tv_usec, (1000000 / HZ)) see https://github.com/torvalds/linux/blob/master/net/vmw_vsock/af_vsock.c#L1571
2. Due to the problem above, test cases sometimes will fail

[root@localhost vsock]# for i in seq 10; do go test -v -race -run TestIntegrationConnTimeout; done
=== RUN TestIntegrationConnTimeout
--- PASS: TestIntegrationConnTimeout (0.01s)
PASS
ok github.com/mdlayher/vsock 0.052s
=== RUN TestIntegrationConnTimeout
TestIntegrationConnTimeout: integration_linux_test.go:235: connect with a very short dial timeout expect ETIMEDOUT, but got
--- FAIL: TestIntegrationConnTimeout (0.00s)
FAIL
exit status 1
FAIL github.com/mdlayher/vsock 0.032s
=== RUN TestIntegrationConnTimeout
--- PASS: TestIntegrationConnTimeout (0.00s)
PASS
ok github.com/mdlayher/vsock 0.049s
=== RUN TestIntegrationConnTimeout
--- PASS: TestIntegrationConnTimeout (0.00s)
PASS
ok github.com/mdlayher/vsock 0.042s
=== RUN TestIntegrationConnTimeout
--- PASS: TestIntegrationConnTimeout (0.00s)
PASS
ok github.com/mdlayher/vsock 0.048s
=== RUN TestIntegrationConnTimeout
--- PASS: TestIntegrationConnTimeout (0.00s)
PASS
ok github.com/mdlayher/vsock 0.046s
=== RUN TestIntegrationConnTimeout
--- PASS: TestIntegrationConnTimeout (0.00s)
PASS
ok github.com/mdlayher/vsock 0.046s
=== RUN TestIntegrationConnTimeout
TestIntegrationConnTimeout: integration_linux_test.go:235: connect with a very short dial timeout expect ETIMEDOUT, but got
--- FAIL: TestIntegrationConnTimeout (0.00s)
FAIL
exit status 1
FAIL github.com/mdlayher/vsock 0.033s
=== RUN TestIntegrationConnTimeout
TestIntegrationConnTimeout: integration_linux_test.go:235: connect with a very short dial timeout expect ETIMEDOUT, but got
--- FAIL: TestIntegrationConnTimeout (0.00s)
FAIL
exit status 1
FAIL github.com/mdlayher/vsock 0.031s
=== RUN TestIntegrationConnTimeout
--- PASS: TestIntegrationConnTimeout (0.00s)
PASS
ok github.com/mdlayher/vsock 0.050s
[root@localhost vsock]#

[mdlayher]

Thank you for the PR and I apologize for the delay: I am mostly on hiatus from open source software development at the moment. However I intend to address this and the other outstanding PRs as part of #45 and will follow up once I'm able to do so. Thanks again.

[mdlayher]

Hi there, I apologize for the delay. With the advent of v1.0.0, perhaps it might make sense to add timeout as a parameter to the vsock.Config struct. I made the decision to share the config fields between Dial and Listen so I'd want to see if a timeout might make sense on that side too.

I'll do some investigation into what socket options are available too.

[ajsinclair]

I wonder if DialContext would be more flexible. It would also match the net and gRPC packages:

• https://pkg.go.dev/net#Dialer.DialContext
• https://pkg.go.dev/google.golang.org/grpc#DialContext

[sheepa]

How would this be done in the current version? Is there some other way to do this?

[SuperQ]

This needs a rebase.