[{"id":3675217,"web_url":"http://patchwork.ozlabs.org/comment/3675217/","msgid":"","list_archive_url":null,"date":"2026-04-09T09:50:34","subject":"Re: [PATCH nf] netfilter: nft_fwd_netdev: use recursion counter in\n neigh egress path","submitter":{"id":1025,"url":"http://patchwork.ozlabs.org/api/people/1025/","name":"Florian Westphal","email":"fw@strlen.de"},"content":"Weiming Shi wrote:\n> Fixes: f87b9464d152 (\"netfilter: nft_fwd_netdev: Support egress hook\")\n> Reported-by: Xiang Mei \n> Signed-off-by: Weiming Shi \n> ---\n> include/net/netfilter/nf_dup_netdev.h | 4 ++++\n> net/netfilter/nf_dup_netdev.c | 18 ++++++++++++++++++\n> net/netfilter/nft_fwd_netdev.c | 7 +++++++\n> 3 files changed, 29 insertions(+)\n> \n> diff --git a/include/net/netfilter/nf_dup_netdev.h b/include/net/netfilter/nf_dup_netdev.h\n> index b175d271aec9..17362f76d1d1 100644\n> --- a/include/net/netfilter/nf_dup_netdev.h\n> +++ b/include/net/netfilter/nf_dup_netdev.h\n> @@ -7,6 +7,10 @@\n> void nf_dup_netdev_egress(const struct nft_pktinfo *pkt, int oif);\n> void nf_fwd_netdev_egress(const struct nft_pktinfo *pkt, int oif);\n> \n> +bool nf_dup_netdev_has_recursed(void);\n> +void nf_dup_netdev_recursion_inc(void);\n> +void nf_dup_netdev_recursion_dec(void);\n> +\n> struct nft_offload_ctx;\n> struct nft_flow_rule;\n> \n> diff --git a/net/netfilter/nf_dup_netdev.c b/net/netfilter/nf_dup_netdev.c\n> index fab8b9011098..e2fe8bb6fe0d 100644\n> --- a/net/netfilter/nf_dup_netdev.c\n> +++ b/net/netfilter/nf_dup_netdev.c\n> @@ -29,6 +29,24 @@ static u8 *nf_get_nf_dup_skb_recursion(void)\n> \n> #endif\n> \n> +bool nf_dup_netdev_has_recursed(void)\n> +{\n> +\treturn *nf_get_nf_dup_skb_recursion() > NF_RECURSION_LIMIT;\n> +}\n> +EXPORT_SYMBOL_GPL(nf_dup_netdev_has_recursed);\n\nI think thats a bit too heavy-handed.\nnf_get_nf_dup_skb_recursion() fetches from pcpu counter or current->.\n\nCan you move nf_get_nf_dup_skb_recursion to a shared header file\nand make it inline instead of having a function call?","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","netfilter-devel@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c09:e001:a7::12fc:5321; helo=sto.lore.kernel.org;\n envelope-from=netfilter-devel+bounces-11754-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=91.216.245.30","smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=strlen.de","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=strlen.de"],"Received":["from sto.lore.kernel.org (sto.lore.kernel.org\n [IPv6:2600:3c09:e001:a7::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4frwD44bJYz1yCv\n\tfor ; Thu, 09 Apr 2026 19:50:44 +1000 (AEST)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sto.lore.kernel.org (Postfix) with ESMTP id 5899C3007899\n\tfor ; Thu, 9 Apr 2026 09:50:41 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 11ECA3B52FA;\n\tThu, 9 Apr 2026 09:50:40 +0000 (UTC)","from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc\n [91.216.245.30])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id E8678348866;\n\tThu, 9 Apr 2026 09:50:36 +0000 (UTC)","by Chamillionaire.breakpoint.cc (Postfix, from userid 1003)\n\tid F3F3760636; Thu, 09 Apr 2026 11:50:34 +0200 (CEST)"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1775728239; cv=none;\n b=O1vw4gGB7YcCi9rDZikl7FiS0z310eNb8RVKYrr1nLTz1WG3qOEUXm8j33OT/VLD9v7zZk+m3iVHtn4rOTWBLU4bc6Lmk2CRD1KmwZybcLHHeyZkoFvV62jwTUKYyRagf4JYVY1erxb19a/XNkTiDSln03xgQcSlb4yas66RQTo=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1775728239; c=relaxed/simple;\n\tbh=i+6hlVdUZ7Xyw2twTV+z+yoWBuQrnAz2c3XD/5XMwDc=;\n\th=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:\n\t Content-Type:Content-Disposition:In-Reply-To;\n b=BGNUvq9GOYh+AkWCVil79gM1lFnQwjEJCGTDtw31pAmk6L69GyA5W99TXZjIyeCTE4A64d/wnpY0MBgxbzwgxHdE2M6DGrhVzqsdL07/71jZVLxmCuCP29DQ/omhZ2o8zUjP6eK1g343dfnEyVImZnjLXaOYugZ0cR3n2watuQY=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=none (p=none dis=none) header.from=strlen.de;\n spf=pass smtp.mailfrom=strlen.de; arc=none smtp.client-ip=91.216.245.30","Date":"Thu, 9 Apr 2026 11:50:34 +0200","From":"Florian Westphal ","To":"Weiming Shi ","Cc":"Pablo Neira Ayuso ,\n\t\"David S . Miller\" ,\n\tEric Dumazet ,\n\tJakub Kicinski , Paolo Abeni ,\n\tPhil Sutter , Simon Horman ,\n\tnetfilter-devel@vger.kernel.org, coreteam@netfilter.org,\n\tnetdev@vger.kernel.org, Xiang Mei ","Subject":"Re: [PATCH nf] netfilter: nft_fwd_netdev: use recursion counter in\n neigh egress path","Message-ID":"","References":"<20260409053629.698822-2-bestswngs@gmail.com>","Precedence":"bulk","X-Mailing-List":"netfilter-devel@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=us-ascii","Content-Disposition":"inline","In-Reply-To":"<20260409053629.698822-2-bestswngs@gmail.com>"}},{"id":3675236,"web_url":"http://patchwork.ozlabs.org/comment/3675236/","msgid":"","list_archive_url":null,"date":"2026-04-09T10:11:53","subject":"Re: [PATCH nf] netfilter: nft_fwd_netdev: use recursion counter in\n neigh egress path","submitter":{"id":92941,"url":"http://patchwork.ozlabs.org/api/people/92941/","name":"Weiming Shi","email":"bestswngs@gmail.com"},"content":"On 26-04-09 11:50, Florian Westphal wrote:\n> Weiming Shi wrote:\n> > Fixes: f87b9464d152 (\"netfilter: nft_fwd_netdev: Support egress hook\")\n> > Reported-by: Xiang Mei \n> > Signed-off-by: Weiming Shi \n> > ---\n> > include/net/netfilter/nf_dup_netdev.h | 4 ++++\n> > net/netfilter/nf_dup_netdev.c | 18 ++++++++++++++++++\n> > net/netfilter/nft_fwd_netdev.c | 7 +++++++\n> > 3 files changed, 29 insertions(+)\n> > \n> > diff --git a/include/net/netfilter/nf_dup_netdev.h b/include/net/netfilter/nf_dup_netdev.h\n> > index b175d271aec9..17362f76d1d1 100644\n> > --- a/include/net/netfilter/nf_dup_netdev.h\n> > +++ b/include/net/netfilter/nf_dup_netdev.h\n> > @@ -7,6 +7,10 @@\n> > void nf_dup_netdev_egress(const struct nft_pktinfo *pkt, int oif);\n> > void nf_fwd_netdev_egress(const struct nft_pktinfo *pkt, int oif);\n> > \n> > +bool nf_dup_netdev_has_recursed(void);\n> > +void nf_dup_netdev_recursion_inc(void);\n> > +void nf_dup_netdev_recursion_dec(void);\n> > +\n> > struct nft_offload_ctx;\n> > struct nft_flow_rule;\n> > \n> > diff --git a/net/netfilter/nf_dup_netdev.c b/net/netfilter/nf_dup_netdev.c\n> > index fab8b9011098..e2fe8bb6fe0d 100644\n> > --- a/net/netfilter/nf_dup_netdev.c\n> > +++ b/net/netfilter/nf_dup_netdev.c\n> > @@ -29,6 +29,24 @@ static u8 *nf_get_nf_dup_skb_recursion(void)\n> > \n> > #endif\n> > \n> > +bool nf_dup_netdev_has_recursed(void)\n> > +{\n> > +\treturn *nf_get_nf_dup_skb_recursion() > NF_RECURSION_LIMIT;\n> > +}\n> > +EXPORT_SYMBOL_GPL(nf_dup_netdev_has_recursed);\n> \n> I think thats a bit too heavy-handed.\n> nf_get_nf_dup_skb_recursion() fetches from pcpu counter or current->.\n> \n> Can you move nf_get_nf_dup_skb_recursion to a shared header file\n> and make it inline instead of having a function call?\n> \n\nThanks for the review. I will send the patch for version v2 as you suggested.\n\nWeiming Shi","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","netfilter-devel@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256\n header.s=20251104 header.b=MoglJCqG;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c04:e001:36c::12fc:5321; helo=tor.lore.kernel.org;\n envelope-from=netfilter-devel+bounces-11756-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com\n header.b=\"MoglJCqG\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=209.85.210.171","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=gmail.com","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=gmail.com"],"Received":["from tor.lore.kernel.org (tor.lore.kernel.org\n [IPv6:2600:3c04:e001:36c::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4frwhl52Xkz1yCv\n\tfor ; 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Miller\" ,\n\tEric Dumazet ,\n\tJakub Kicinski , Paolo Abeni ,\n\tPhil Sutter , Simon Horman ,\n\tnetfilter-devel@vger.kernel.org, coreteam@netfilter.org,\n\tnetdev@vger.kernel.org, Xiang Mei ","Subject":"Re: [PATCH nf] netfilter: nft_fwd_netdev: use recursion counter in\n neigh egress path","Message-ID":"","References":"<20260409053629.698822-2-bestswngs@gmail.com>\n ","Precedence":"bulk","X-Mailing-List":"netfilter-devel@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","Content-Type":"text/plain; charset=us-ascii","Content-Disposition":"inline","In-Reply-To":""}}]