Re: [PATCH,TRIVIAL] AF_UNIX, accept() and addrlen

From: Andi Kleen
Date: Mon Mar 24 2008 - 07:50:42 EST


Samuel Thibault <samuel.thibault@xxxxxxxxxxxx> writes:

> David Miller, le Sun 23 Mar 2008 21:56:41 -0700, a Ãcrit :
> > From: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
> > Date: Sat, 8 Mar 2008 02:23:21 +0000
> >
> > > Accept and getpeername are supposed to return the amount of bytes
> > > written in the returned address. However, on unnamed sockets, only
> > > sizeof(short) is returned, while a 0 is put in the sun_path member.
> > > This patch adds 1 for that additional byte.
> > >
> > > Signed-off-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
> >
> > This change isn't correct. It's the fact that the
> > length returned is sizeof(short) that tells the caller
> > that the unix socket is unnamed.
>
> Mmm, where that is documented?
>
> I can't find any details about that in SUS, and man 7 unix says
>
> `If sun_path starts with a null byte ('' '), then it refers to the
> abstract namespace main- tained by the Unix protocol module.'

[I wrote unix(7) originally]. The abstract name space is a Linux
extension and there is no written standard and whatever the kernel
implements is the de-facto standard. If unix(7) differs in anything
from what the code does please send patches to the manpages
maintainer.

-Andi
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