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Date: Wed, 12 Aug 2009 16:20:33 +0100
From: Jon TURNEY <jon DOT turney AT dronecode DOT org DOT uk>
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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]]
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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 :-)


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