From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Sutter Subject: Re: [nft PATCH RFC v2 3/4] Implement --echo option Date: Thu, 27 Jul 2017 19:00:34 +0200 Message-ID: <20170727170034.GT2235@orbyte.nwl.cc> References: <20170727162144.28703-1-phil@nwl.cc> <20170727162144.28703-4-phil@nwl.cc> <20170727164300.GA10637@salvia> <20170727165435.GS2235@orbyte.nwl.cc> <20170727165647.GA10869@salvia> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netfilter-devel@vger.kernel.org To: Pablo Neira Ayuso Return-path: Received: from orbyte.nwl.cc ([151.80.46.58]:47215 "EHLO mail.nwl.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751509AbdG0RAf (ORCPT ); Thu, 27 Jul 2017 13:00:35 -0400 Content-Disposition: inline In-Reply-To: <20170727165647.GA10869@salvia> Sender: netfilter-devel-owner@vger.kernel.org List-ID: On Thu, Jul 27, 2017 at 06:56:47PM +0200, Pablo Neira Ayuso wrote: > On Thu, Jul 27, 2017 at 06:54:35PM +0200, Phil Sutter wrote: > > On Thu, Jul 27, 2017 at 06:43:00PM +0200, Pablo Neira Ayuso wrote: > > > On Thu, Jul 27, 2017 at 06:21:43PM +0200, Phil Sutter wrote: > > > > diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h > > > > index 40096de04e963..70404f724808a 100644 > > > > --- a/include/linux/netfilter/nf_tables.h > > > > +++ b/include/linux/netfilter/nf_tables.h > > > > @@ -114,6 +114,7 @@ enum nf_tables_msg_types { > > > > NFT_MSG_GETOBJ, > > > > NFT_MSG_DELOBJ, > > > > NFT_MSG_GETOBJ_RESET, > > > > + NFT_MSG_META_ECHO, > > > > > > Why this? > > > > See netlink_echo_callback(): I want to reuse monitor code as much as > > possible, and therefore introduced that function as common callback > > dispatching to monitor callbacks. In order to make them print data like > > I want them to, I need to have an indicator. The simplest way was to > > introduce this fake type which in callbacks acts as third option to > > NFT_MSG_NEW* or NFT_MSG_DEL*. > > Hm, there must be a way to reuse this code without adding a new > message type. From a netlink perspective, users should just set on the > NLM_ECHO flag to get echo reports. I don't want to have a new message > type for this. Ah, maybe you misinterpreted it's scope: I gave it this weird name because that message type actually doesn't exist from kernel PoV. It's solely used in between netlink_echo_callback() and the netlink_events_*_cb() functions it calls. It's pretty much just a hack, but allowed me to get by without bigger changes to the callback functions shared with monitor code. Cheers, Phil