From db66e383c33228c43efbe16ad3b14ae9833879dc Mon Sep 17 00:00:00 2001 From: Brian Geffon Date: Tue, 19 Jun 2018 17:28:19 -0700 Subject: Epsocket has incorrect recv(2) behavior after SHUT_RD. After shutdown(SHUT_RD) calls to recv /w MSG_DONTWAIT or with O_NONBLOCK should result in a EAGAIN and not 0. Blocking sockets should return 0 as they would have otherwise blocked indefinitely. PiperOrigin-RevId: 201271123 Change-Id: If589b69c17fa5b9ff05bcf9e44024da9588c8876 --- pkg/sentry/socket/epsocket/epsocket.go | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'pkg') diff --git a/pkg/sentry/socket/epsocket/epsocket.go b/pkg/sentry/socket/epsocket/epsocket.go index 9ff9af0bc..a1bb265c0 100644 --- a/pkg/sentry/socket/epsocket/epsocket.go +++ b/pkg/sentry/socket/epsocket/epsocket.go @@ -952,6 +952,12 @@ func (s *SocketOperations) RecvMsg(t *kernel.Task, dst usermem.IOSequence, flags senderRequested = false } n, senderAddr, senderAddrLen, controlMessages, err = s.nonBlockingRead(t, dst, peek, trunc, senderRequested) + + if err == syserr.ErrClosedForReceive && flags&linux.MSG_DONTWAIT != 0 { + // In this situation we should return EAGAIN. + return 0, nil, 0, socket.ControlMessages{}, syserr.ErrTryAgain + } + if err != syserr.ErrWouldBlock || flags&linux.MSG_DONTWAIT != 0 { return } -- cgit v1.2.3