Subject: Re: [RFC] net: netlink -- Allow netlink_dump to return error code if protocol handler is missed

From: Cyrill Gorcunov <[email-masked]>
Date: Sat, 3 Nov 2012 23:16:17 +0400

On Sat, Nov 03, 2012 at 08:39:58PM +0400, Cyrill Gorcunov wrote:
> On Sat, Nov 03, 2012 at 08:17:50PM +0400, Pavel Emelyanov wrote:
> > >  static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
> > > Index: linux-2.6.git/net/netlink/af_netlink.c
> > > ===================================================================
> > > --- linux-2.6.git.orig/net/netlink/af_netlink.c
> > > +++ linux-2.6.git/net/netlink/af_netlink.c
> > > @@ -1740,6 +1740,10 @@ static int netlink_dump(struct sock *sk)
> > >  		else
> > >  			__netlink_sendskb(sk, skb);
> > >  		return 0;
> > > +	} else if (len < 0) {
> > > +		err = len;
> > > +		nlk->cb = NULL;
> > > +		goto errout_skb;
> > 
> > When family-level handler is absent and sock_diag returns error this error
> > gets propagated back to user without this fix. Why do we need it in case
> > we return error from protocol-level handler?
> 
> Because as far as I can say the family-level handler already has such error
> returning code in __sock_diag_rcv_msg. Or you mean something else?

OK, it seems I got what you mean, cooking/testing new patch.