From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gao feng Subject: Re: [PATCH 01/17] netfilter: add struct nf_proto_net for register l4proto sysctl Date: Fri, 25 May 2012 14:02:37 +0800 Message-ID: <4FBF207D.80809@cn.fujitsu.com> References: <1336985547-31960-1-git-send-email-gaofeng@cn.fujitsu.com> <1336985547-31960-2-git-send-email-gaofeng@cn.fujitsu.com> <20120523101200.GA2836@1984> <4FBD9076.6060309@cn.fujitsu.com> <20120524095859.GC13091@1984> <4FBE1372.60206@cn.fujitsu.com> <20120524143854.GA15898@1984> <4FBEDADE.8040905@cn.fujitsu.com> <20120525025451.GA21076@1984> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, serge.hallyn@canonical.com, ebiederm@xmission.com, dlezcano@fr.ibm.com, Gao feng To: Pablo Neira Ayuso Return-path: In-Reply-To: <20120525025451.GA21076@1984> Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org =E4=BA=8E 2012=E5=B9=B405=E6=9C=8825=E6=97=A5 10:54, Pablo Neira Ayuso = =E5=86=99=E9=81=93: > On Fri, May 25, 2012 at 09:05:34AM +0800, Gao feng wrote: >> =E4=BA=8E 2012=E5=B9=B405=E6=9C=8824=E6=97=A5 22:38, Pablo Neira Ayu= so =E5=86=99=E9=81=93: >>> On Thu, May 24, 2012 at 06:54:42PM +0800, Gao feng wrote: >>> [...] >>>>>>> I don't see why we need this new field. >>>>>>> >>>>>>> It seems to be set to 1 in each structure that has set: >>>>>>> >>>>>>> .ctl_compat_table >>>>>>> >>>>>>> to non-NULL. So, it's redundant. >>>>>>> >>>>>>> Moreover, you already know from the protocol tracker itself if = you >>>>>>> have to allocate the compat ctl table or not. >>>>>>> >>>>>>> In other words: You set compat to 1 for nf_conntrack_l4proto_ge= neric. >>>>>>> Then, you pass that compat value to generic_init_net via ->inet= _net >>>>>>> again, but this information (that determines if the compat has = to be >>>>>>> done or not) is already in the scope of the protocol tracker. >>>>>>> >>>>>> >>>>>> because some protocols such l4proto_tcp6 and l4proto_tcp use the= same init_net >>>>>> function. the l4proto_tcp6 doesn't need compat sysctl, so we sho= uld use this new >>>>>> field to identify if we should kmemdup compat_sysctl_table. >>>>> >>>>> Then, could you use two init_net functions? one for TCP for IPv4 = and another >>>>> for TCP for IPv6? >>>> >>>> Of cause, if you prefer to impletment it in this way. >>> >>> If this removes the .compat field that you added, then use two >>> init_net functions, yes. >> >> Sorry I miss something. >> >> nf_ct_l4proto_unregister_sysctl also uses .compat to identify if we >> can unregister the compat sysctl. >> >> if we register l4proto_tcp and l4proto_tcp6 both. without .compat, >> when unregister l4proto_tcp6, the compat sysctl will be unregister t= oo. >> >> So maybe we have to use .compat. >=20 > Could you resolve this by checking pn->ctl_compat_header !=3D NULL ? pn->ctl_table_header and ctl_compat_header is shared by l4proto_tcp and= l4proto_tcp6. if we both register l4proto_tcp and l4proto_tcp6, when unregister l4pro= to_tcp6 pn->ctl_compat_header must not be NULL. -- To unsubscribe from this list: send the line "unsubscribe netfilter-dev= el" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html