To: linux-kernel@vger.kernel.org
From: hpa@zytor.com (H. Peter Anvin)
Subject: Re: UDP recvmsg blocks after select(), 2.6 bug?
Date: Wed, 20 Oct 2004 21:31:38 +0000 (UTC)
Organization: Mostly alphabetical, except Q, which We do not fancy
Message-ID: <cl6lfq$jlg$1@terminus.zytor.com>
References: <20041016062512.GA17971@mark.mielke.cc> <MDEHLPKNGKAHNMBLJOLKMEONPAAA.davids@webmaster.com> <20041017133537.GL7468@marowsky-bree.de>
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Followup to:  <20041017133537.GL7468@marowsky-bree.de>
By author:    Lars Marowsky-Bree <lmb@suse.de>
In newsgroup: linux.dev.kernel
> 
> This actually forbids recvmsg() to return EAGAIN and EWOULDBLOCK as
> has been suggested. EIO seems to be the best fit.
> 
> But I'd have to agree that blocking on recvmsg() after select() has
> indicated ready to read does violate the specification, unless the
> socket has actually been opened with O_NONBLOCK.
> 

EIO seems to be The Right Thing[TM]... it pretty much says "yes, we
received something, but it was bad."  What isn't clear to me is how
applications react to EIO.  It could easily be considered a fatal
error... :-/

	-hpa
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