From patchwork Mon Oct 12 01:38:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 270121 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F017DC4363D for ; Mon, 12 Oct 2020 01:38:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6E702078E for ; Mon, 12 Oct 2020 01:38:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727722AbgJLBih (ORCPT ); Sun, 11 Oct 2020 21:38:37 -0400 Received: from correo.us.es ([193.147.175.20]:41718 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727461AbgJLBic (ORCPT ); Sun, 11 Oct 2020 21:38:32 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id C614CE780F for ; Mon, 12 Oct 2020 03:38:30 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id B841ADA789 for ; Mon, 12 Oct 2020 03:38:30 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id ADAA4DA730; Mon, 12 Oct 2020 03:38:30 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id A71FCDA789; Mon, 12 Oct 2020 03:38:28 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Mon, 12 Oct 2020 03:38:28 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from localhost.localdomain (unknown [90.77.255.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: pneira@us.es) by entrada.int (Postfix) with ESMTPSA id 7863D41FF201; Mon, 12 Oct 2020 03:38:28 +0200 (CEST) X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org Subject: [PATCH 4/6] netfilter: add inet ingress support Date: Mon, 12 Oct 2020 03:38:17 +0200 Message-Id: <20201012013819.23128-5-pablo@netfilter.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201012013819.23128-1-pablo@netfilter.org> References: <20201012013819.23128-1-pablo@netfilter.org> MIME-Version: 1.0 X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch adds the NF_INET_INGRESS pseudohook for the NFPROTO_INET family. This is a mapping this new hook to the existing NFPROTO_NETDEV and NF_NETDEV_INGRESS hook. The hook does not guarantee that packets are inet only, users must filter out non-ip traffic explicitly. This infrastructure makes it easier to support this new hook in nf_tables. Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter.h | 1 + net/netfilter/core.c | 103 ++++++++++++++++++++++++++------- 2 files changed, 83 insertions(+), 21 deletions(-) diff --git a/include/uapi/linux/netfilter.h b/include/uapi/linux/netfilter.h index ca9e63d6e0e4..6a6179af0d7c 100644 --- a/include/uapi/linux/netfilter.h +++ b/include/uapi/linux/netfilter.h @@ -45,6 +45,7 @@ enum nf_inet_hooks { NF_INET_FORWARD, NF_INET_LOCAL_OUT, NF_INET_POST_ROUTING, + NF_INET_INGRESS, NF_INET_NUMHOOKS }; diff --git a/net/netfilter/core.c b/net/netfilter/core.c index c82f779a587e..63d032191e62 100644 --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -281,6 +281,16 @@ nf_hook_entry_head(struct net *net, int pf, unsigned int hooknum, if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_bridge) <= hooknum)) return NULL; return net->nf.hooks_bridge + hooknum; +#endif +#ifdef CONFIG_NETFILTER_INGRESS + case NFPROTO_INET: + if (WARN_ON_ONCE(hooknum != NF_INET_INGRESS)) + return NULL; + if (!dev || dev_net(dev) != net) { + WARN_ON_ONCE(1); + return NULL; + } + return &dev->nf_hooks_ingress; #endif case NFPROTO_IPV4: if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_ipv4) <= hooknum)) @@ -311,22 +321,56 @@ nf_hook_entry_head(struct net *net, int pf, unsigned int hooknum, return NULL; } +static int nf_ingress_check(struct net *net, const struct nf_hook_ops *reg, + int hooknum) +{ +#ifndef CONFIG_NETFILTER_INGRESS + if (reg->hooknum == hooknum) + return -EOPNOTSUPP; +#endif + if (reg->hooknum != hooknum || + !reg->dev || dev_net(reg->dev) != net) + return -EINVAL; + + return 0; +} + static inline bool nf_ingress_hook(const struct nf_hook_ops *reg, int pf) { - return pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_INGRESS; + if ((pf == NFPROTO_NETDEV && reg->hooknum == NF_NETDEV_INGRESS) || + (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS)) + return true; + + return false; } static void nf_static_key_inc(const struct nf_hook_ops *reg, int pf) { #ifdef CONFIG_JUMP_LABEL - static_key_slow_inc(&nf_hooks_needed[pf][reg->hooknum]); + int hooknum; + + if (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS) { + pf = NFPROTO_NETDEV; + hooknum = NF_NETDEV_INGRESS; + } else { + hooknum = reg->hooknum; + } + static_key_slow_inc(&nf_hooks_needed[pf][hooknum]); #endif } static void nf_static_key_dec(const struct nf_hook_ops *reg, int pf) { #ifdef CONFIG_JUMP_LABEL - static_key_slow_dec(&nf_hooks_needed[pf][reg->hooknum]); + int hooknum; + + if (pf == NFPROTO_INET && reg->hooknum == NF_INET_INGRESS) { + pf = NFPROTO_NETDEV; + hooknum = NF_NETDEV_INGRESS; + } else { + hooknum = reg->hooknum; + } + static_key_slow_dec(&nf_hooks_needed[pf][hooknum]); #endif } @@ -335,15 +379,22 @@ static int __nf_register_net_hook(struct net *net, int pf, { struct nf_hook_entries *p, *new_hooks; struct nf_hook_entries __rcu **pp; + int err; - if (pf == NFPROTO_NETDEV) { -#ifndef CONFIG_NETFILTER_INGRESS - if (reg->hooknum == NF_NETDEV_INGRESS) - return -EOPNOTSUPP; -#endif - if (reg->hooknum != NF_NETDEV_INGRESS || - !reg->dev || dev_net(reg->dev) != net) - return -EINVAL; + switch (pf) { + case NFPROTO_NETDEV: + err = nf_ingress_check(net, reg, NF_NETDEV_INGRESS); + if (err < 0) + return err; + break; + case NFPROTO_INET: + if (reg->hooknum != NF_INET_INGRESS) + break; + + err = nf_ingress_check(net, reg, NF_INET_INGRESS); + if (err < 0) + return err; + break; } pp = nf_hook_entry_head(net, pf, reg->hooknum, reg->dev); @@ -441,8 +492,12 @@ static void __nf_unregister_net_hook(struct net *net, int pf, void nf_unregister_net_hook(struct net *net, const struct nf_hook_ops *reg) { if (reg->pf == NFPROTO_INET) { - __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); - __nf_unregister_net_hook(net, NFPROTO_IPV6, reg); + if (reg->hooknum == NF_INET_INGRESS) { + __nf_unregister_net_hook(net, NFPROTO_INET, reg); + } else { + __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); + __nf_unregister_net_hook(net, NFPROTO_IPV6, reg); + } } else { __nf_unregister_net_hook(net, reg->pf, reg); } @@ -467,14 +522,20 @@ int nf_register_net_hook(struct net *net, const struct nf_hook_ops *reg) int err; if (reg->pf == NFPROTO_INET) { - err = __nf_register_net_hook(net, NFPROTO_IPV4, reg); - if (err < 0) - return err; - - err = __nf_register_net_hook(net, NFPROTO_IPV6, reg); - if (err < 0) { - __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); - return err; + if (reg->hooknum == NF_INET_INGRESS) { + err = __nf_register_net_hook(net, NFPROTO_INET, reg); + if (err < 0) + return err; + } else { + err = __nf_register_net_hook(net, NFPROTO_IPV4, reg); + if (err < 0) + return err; + + err = __nf_register_net_hook(net, NFPROTO_IPV6, reg); + if (err < 0) { + __nf_unregister_net_hook(net, NFPROTO_IPV4, reg); + return err; + } } } else { err = __nf_register_net_hook(net, reg->pf, reg);