From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH] ip: set the close-on-exec flag for descriptors
Date: Mon, 8 Jul 2013 12:50:07 -0700
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Cc: Eric Dumazet <eric.dumazet@gmail.com>, netdev@vger.kernel.org
To: Andrey Wagin <avagin@gmail.com>
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On Mon, 8 Jul 2013 23:23:35 +0400
Andrey Wagin <avagin@gmail.com> wrote:

> 2013/7/8 Eric Dumazet <eric.dumazet@gmail.com>:
> > 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()
> >
> 
> Yes, it's good idea. Look at the attached patch.
> 
> Thanks.
> 
> >
> >

Just always do the fcntl(), it makes more sense rather than having
two code paths.