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

[Andi Kleen <andi@firstfloor.org>]

Samuel Thibault <samuel.thibault@ens-lyon.org> writes:

> David Miller, le Sun 23 Mar 2008 21:56:41 -0700, a écrit :
> > From: Samuel Thibault <samuel.thibault@ens-lyon.org>
> > 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@ens-lyon.org>
> > 
> > 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