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Date: Mon, 7 Jun 2004 11:44:10 +0400
From: Gleb Smirnoff <glebius@cell.sick.ru>
To: Ruslan Ermilov <ru@freebsd.org>
Message-ID: <20040607074410.GC18232@cell.sick.ru>
References: <Pine.BSF.4.21.0406061825360.15217-100000@InterJet.elischer.org>
	<20040607071701.GC17986@cell.sick.ru> <20040607073812.GA339@ip.net.ua>
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cc: Julian Elischer <julian@elischer.org>
cc: net@freebsd.org
Subject: Re: HEADSUP! netgraph Metadata changing.
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On Mon, Jun 07, 2004 at 10:38:12AM +0300, Ruslan Ermilov wrote:
R> On Mon, Jun 07, 2004 at 11:17:01AM +0400, Gleb Smirnoff wrote:
R> > On Sun, Jun 06, 2004 at 06:35:51PM -0700, Julian Elischer wrote:
R> > J> In addition the ng_ksocket node adds info into metadata and I suspect
R> > J> there are people using that.
R> > 
R> > Since ng_ksocket tags packets for itself only, we can safely change it.
R> > 
R> I use this feature in one proprietary module (need to send/recevive
R> UDP datagrams to/from different destinations).

Does your module reads/writes meta? Or just forwards the meta? If it just
forwards meta, does it allocate new mbuf? If it does, then you should copy
tag from old mbuf to a new one. If it does not allocate new mbuf, than
our ng_ksocket change won't break your module.

-- 
Totus tuus, Glebius.
GLEBIUS-RIPN GLEB-RIPE