From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH] ip: set the close-on-exec flag for descriptors
Date: Mon, 08 Jul 2013 09:05:06 -0700
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Cc: Stephen Hemminger <stephen@networkplumber.org>,
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To: Andrey Wagin <avagin@gmail.com>
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On Mon, 2013-07-08 at 19:51 +0400, Andrey Wagin wrote:
> Hi Eric,
> 
> 2013/7/8 Eric Dumazet <eric.dumazet@gmail.com>:
> >> Applied
> >
> > It seems it could break ip command for old kernels, as SOCK_CLOEXEC is
> > supported from 2.6.27
> >
> > Not sure if its worth a patch, to do the normal socket() call followed
> > by legacy fcntl() one.
> 
> fcntl is not safe for multithread applications. If libnetlink isn't
> going to be used for them, I don't have objection. The patch is
> attached.
> 

If you want multithread safety, you could attempt the SOCK_CLOEXEC, and
fall back in case of error to legacy socket()/fcntl()