From d06de1bede9c40078fe674a6df4849fe3322a861 Mon Sep 17 00:00:00 2001 From: Dean Deng Date: Tue, 19 May 2020 11:40:15 -0700 Subject: Fix flaky udp tests by polling before reading. On native Linux, calling recv/read right after send/write sometimes returns EWOULDBLOCK, if the data has not made it to the receiving socket (even though the endpoints are on the same host). Poll before reading to avoid this. Making this change also uncovered a hostinet bug (gvisor.dev/issue/2726), which is noted in this CL. PiperOrigin-RevId: 312320587 --- pkg/sentry/socket/hostinet/socket.go | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'pkg') diff --git a/pkg/sentry/socket/hostinet/socket.go b/pkg/sentry/socket/hostinet/socket.go index b49433326..c11e82c10 100644 --- a/pkg/sentry/socket/hostinet/socket.go +++ b/pkg/sentry/socket/hostinet/socket.go @@ -555,7 +555,7 @@ func (s *socketOpsCommon) SendMsg(t *kernel.Task, src usermem.IOSequence, to []b if uint64(src.NumBytes()) != srcs.NumBytes() { return 0, nil } - if srcs.IsEmpty() { + if srcs.IsEmpty() && len(controlBuf) == 0 { return 0, nil } -- cgit v1.2.3