X-Recipient:	archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status:	No, hits=-3.3 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW
X-Spam-Check-By:	sourceware.org
Message-ID:	<4A82DDC1.6050800@dronecode.org.uk>
Date:	Wed, 12 Aug 2009 16:20:33 +0100
From:	Jon TURNEY <jon DOT turney AT dronecode DOT org DOT uk>
User-Agent:	Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.1) Gecko/20090715 Thunderbird/3.0b3
MIME-Version:	1.0
To:	cygwin-xfree AT cygwin DOT com, cygwin AT cygwin DOT com
Subject:	Re: [1.7] IPv6 accept() fails if address_len is < sizeof(sockaddr_in6) [was Re: PATCH /usr/include/X11/Xtrans/Xtranssock.c [WAS: Re: xhost package not compiled for IPv6]]
References:	<4A78A511 DOT 8020109 AT sipxx DOT com> <4A803D7C DOT 6070800 AT dronecode DOT org DOT uk> <4A825EE5 DOT 5020709 AT sipxx DOT com> <4A82BB83 DOT 1090908 AT dronecode DOT org DOT uk> <4A82C835 DOT 9030504 AT dronecode DOT org DOT uk> <20090812135941 DOT GD13438 AT calimero DOT vinschen DOT de>
In-Reply-To:	<20090812135941.GD13438@calimero.vinschen.de>
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com

On 12/08/2009 14:59, Corinna Vinschen wrote:
> On Aug 12 14:48, Jon TURNEY wrote:
>> On 12/08/2009 13:54, Jon TURNEY wrote:
>>> Hmmm... but if it's really the size of the sockname argument which is
>>> causing the accept() to fail, this would be a bug in cygwin's accept()
>>> implementation, as it's supposed to truncate the data written to the
>>> sockname, rather than fail if it won't fit [1]. If that actually is the
>>> case, since we don't actually use the peer address here, the code as
>>> stands is correct (if a little odd).
>>>
>>> I suppose I need to write a small test case to look at this...
>>>
>>> [1] http://www.opengroup.org/onlinepubs/009695399/functions/accept.html
>>
>> A couple of small programs which hopefully demonstrate this problem.
>>
>> (As is, the connection fails, but uncommenting the alternate definition
>> of cliaddr in listener.c allows it to work)
>>
>> I'd hazard a guess that perhaps this is because the underlying winsock
>> accept() doesn't have this truncate behaviour and considers a too-small
>> address_len an error.
>
> Thanks for the testcase!

Oh, I meant to say "A couple of small programs shamelessly copied from UNIX 
Network Programming".  So don't thank me, thank W. Richard Stevens :-)


--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

- Raw text -