Re: [PATCH 4/8] man/man7/unix.7: Explain Abstract UDS scoping to the network namespace

["Günther Noack" <gnoack3000@gmail.com>]

Hello! Thanks for the review!

On Sat, Oct 24, 2026 at 05:39:52AM +0000, Kuniyuki Iwashima wrote:
> On Wed, 21 Oct 2026 23:07:56 +0200, Günther Noack wrote:
> > Point out that Abstract Unix Domain Sockets are visible within the
> > current network namespace, unlike Named Unix Domain Sockets, where the
> 
> s/Named/pathname/.
> 
> pathname, unnamed, abstract are used in Address format section.

Thanks, fixed.


> > remote socket is looked up through the mount namespace.
> > 
> > To avoid confusion, remove the word "namespace" from the subsequent
> > paragraph, where it is used in a more colloquial form (there is no
> > abstract socket namespace in the sense of namespaces(7)).
> 
> The change still uses "abstract socket namespace".

In the "Abstract Sockets" section, the word "namespace" is not used
any more in the general sense, but only in the sense of a
setns(2)/namespaces(7) namespace.

There are some places in the man page where the word "namespace" is
still used colloquially, but these are not in the vicinity of this
change and feel less prone to confusion.  Do you think I should update
these all in the same commit?


> > This is already described in network_namespaces(7) as well, but might
> > be mentionworthy here too.
> > 
> > The lookup of Abtract addresses happens in __unix_find_socket_byname()
> > in linux.git net/unix/af_unix.c, where it is looked up in the network
> > namespace (struct net *net) in a hash table in that namespace:
> > 
> > 	sk_for_each(s, &net->unx.table.buckets[hash]) {
> > 		// ...
> > 	}
> > 
> > Cc: Kuniyuki Iwashima <kuniyu@google.com>
> > Assisted-by: LLM
> > Signed-off-by: Günther Noack <gnoack3000@gmail.com>
> > ---
> > 
> > Notes:
> >     Verified in code
> > 
> >  man/man7/unix.7 | 12 +++++++++++-
> >  1 file changed, 11 insertions(+), 1 deletion(-)
> > 
> > diff --git a/man/man7/unix.7 b/man/man7/unix.7
> > index 4c46b54206a5..232fdbf4c3cd 100644
> > --- a/man/man7/unix.7
> > +++ b/man/man7/unix.7
> > @@ -257,7 +257,17 @@ has no effect on the accessibility of the socket.
> >  Abstract sockets automatically disappear when all open references
> >  to the socket are closed.
> >  .P
> > -The abstract socket namespace is a nonportable Linux extension.
> > +Each network namespace has its own abstract socket namespace (see
> > +.BR network_namespaces (7)):
> 
> Remove this sentence and...
> 
> 
> > +a socket can connect or send to an abstract address
> > +only if the socket bound to that address
> > +is in the same network namespace.
> 
> add "(see network_namespaces (7))" here.

Good idea, that's shorter.


> > +In contrast,
> > +pathname sockets are not confined to a network namespace;
> > +they can be reached from any network namespace
> > +in which the socket file is accessible.
> > +.P
> > +Abstract sockets are a nonportable Linux extension.
> >  .\"
> >  .SS Socket options
> >  For historical reasons, these socket options are specified with a
> > -- 
> > 2.56.0
> > 

Thanks,
–Günther