From mboxrd@z Thu Jan 1 00:00:00 1970 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 7FFDBC433FE for ; Mon, 20 Sep 2021 01:00:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6176160F0F for ; Mon, 20 Sep 2021 01:00:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232196AbhITBB3 (ORCPT ); Sun, 19 Sep 2021 21:01:29 -0400 Received: from gate2.alliedtelesis.co.nz ([202.36.163.20]:39822 "EHLO gate2.alliedtelesis.co.nz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230495AbhITBBZ (ORCPT ); Sun, 19 Sep 2021 21:01:25 -0400 Received: from svr-chch-seg1.atlnz.lc (mmarshal3.atlnz.lc [10.32.18.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by gate2.alliedtelesis.co.nz (Postfix) with ESMTPS id 4FEDB891B0; Mon, 20 Sep 2021 12:59:58 +1200 (NZST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alliedtelesis.co.nz; s=mail181024; t=1632099598; bh=BXBSdvV8Uw8p/lcDAGtjdVDMdp9Ng+Z5hgigHy3GrVc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=U/JacD8xbmwJ1/njlawEoN+JOU/diydoIMHUYhlcW7KJMN6rmBwx2a2Qrj1jlMIf8 gS/q4vYGLEebQcHVkX6ioTVeQFNyYWTJTHk2khGHNiYwAq2xOH3oH9JRdHcRvGoA01 7YeNC2Tr9d7IQza3rQbHlaVb2inw0yboJlUpO6e5ZFRT7UoY9P60ltI8WOCBrzmU18 vecVYvtI5hiLNrFlwcuwWxpEjocGTJFgq5PacESXOBOjEt/h/2YxPlzdyDNlfs+rL8 +OYhAUEcs16tqW1x7s6JTIGZLZBJTCLLMF+BWdJoxG6isM+BgzACN2rl8ur9VJX2Zu jV7lVKoGd2q2A== Received: from pat.atlnz.lc (Not Verified[10.32.16.33]) by svr-chch-seg1.atlnz.lc with Trustwave SEG (v8,2,6,11305) id ; Mon, 20 Sep 2021 13:00:08 +1200 Received: from coled-dl.ws.atlnz.lc (coled-dl.ws.atlnz.lc [10.33.25.26]) by pat.atlnz.lc (Postfix) with ESMTP id 151E413EE58; Mon, 20 Sep 2021 12:59:58 +1200 (NZST) Received: by coled-dl.ws.atlnz.lc (Postfix, from userid 1801) id 117ED24285E; Mon, 20 Sep 2021 12:59:58 +1200 (NZST) From: Cole Dishington To: pablo@netfilter.org, kadlec@netfilter.org, fw@strlen.de, davem@davemloft.net, kuba@kernel.org, shuah@kernel.org Cc: linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, Cole Dishington , Anthony Lineham , Scott Parlane , Blair Steven Subject: [PATCH net v5 2/2] net: netfilter: Fix port selection of FTP for NF_NAT_RANGE_PROTO_SPECIFIED Date: Mon, 20 Sep 2021 12:59:05 +1200 Message-Id: <20210920005905.9583-3-Cole.Dishington@alliedtelesis.co.nz> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210920005905.9583-1-Cole.Dishington@alliedtelesis.co.nz> References: <20210920005905.9583-1-Cole.Dishington@alliedtelesis.co.nz> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SEG-SpamProfiler-Analysis: v=2.3 cv=FtN7AFjq c=1 sm=1 tr=0 a=KLBiSEs5mFS1a/PbTCJxuA==:117 a=7QKq2e-ADPsA:10 a=xOT0nC9th1TpZTiSAT0A:9 a=7Zwj6sZBwVKJAoWSPKxL6X1jA+E=:19 X-SEG-SpamProfiler-Score: 0 x-atlnz-ls: pat Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org FTP port selection ignores specified port ranges (with iptables masquerade --to-ports) when creating an expectation, based on FTP commands PORT or PASV, for the data connection. For masquerading, this issue allows an FTP client to use unassigned source ports for their data connection (in both the PORT and PASV cases). This can cause problems in setups that allocate different masquerade port ranges for each client. The proposed fix involves storing a port range (on nf_conn_nat) to: - Fix FTP PORT data connections using the stored port range to select a port number in nf_conntrack_ftp. - Fix FTP PASV data connections using the stored port range to specify a port range on source port in nf_nat_helper if the FTP PORT/PASV packet comes from the client. Co-developed-by: Anthony Lineham Signed-off-by: Anthony Lineham Co-developed-by: Scott Parlane Signed-off-by: Scott Parlane Co-developed-by: Blair Steven Signed-off-by: Blair Steven Signed-off-by: Cole Dishington --- include/net/netfilter/nf_nat.h | 6 ++++++ net/netfilter/nf_nat_core.c | 9 +++++++++ net/netfilter/nf_nat_ftp.c | 22 +++++++++++++++++++--- net/netfilter/nf_nat_helper.c | 10 ++++++++++ 4 files changed, 44 insertions(+), 3 deletions(-) diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_na= t.h index 0d412dd63707..231cffc16722 100644 --- a/include/net/netfilter/nf_nat.h +++ b/include/net/netfilter/nf_nat.h @@ -27,12 +27,18 @@ union nf_conntrack_nat_help { #endif }; =20 +struct nf_conn_nat_range_info { + union nf_conntrack_man_proto min_proto; + union nf_conntrack_man_proto max_proto; +}; + /* The structure embedded in the conntrack structure. */ struct nf_conn_nat { union nf_conntrack_nat_help help; #if IS_ENABLED(CONFIG_NF_NAT_MASQUERADE) int masq_index; #endif + struct nf_conn_nat_range_info range_info; }; =20 /* Set up the info structure to map into this range. */ diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index b7c3c902290f..2acec7fd56bd 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -623,6 +623,15 @@ nf_nat_setup_info(struct nf_conn *ct, &ct->tuplehash[IP_CT_DIR_REPLY].tuple); =20 get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype); + if (range && (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) { + struct nf_conn_nat *nat =3D nf_ct_nat_ext_add(ct); + + if (!nat) + return NF_DROP; + + nat->range_info.min_proto =3D range->min_proto; + nat->range_info.max_proto =3D range->max_proto; + } =20 if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) { struct nf_conntrack_tuple reply; diff --git a/net/netfilter/nf_nat_ftp.c b/net/netfilter/nf_nat_ftp.c index 7dcb4f179ac9..baf353932cd4 100644 --- a/net/netfilter/nf_nat_ftp.c +++ b/net/netfilter/nf_nat_ftp.c @@ -72,12 +72,16 @@ static unsigned int nf_nat_ftp(struct sk_buff *skb, u_int16_t port; int dir =3D CTINFO2DIR(ctinfo); struct nf_conn *ct =3D exp->master; + struct nf_conn_nat *nat =3D nfct_nat(ct); unsigned int i, min, max, range_size; static const unsigned int max_attempts =3D 128; char buffer[sizeof("|1||65535|") + INET6_ADDRSTRLEN]; unsigned int buflen; int ret; =20 + if (WARN_ON_ONCE(!nat)) + return NF_DROP; + pr_debug("type %i, off %u len %u\n", type, matchoff, matchlen); =20 /* Connection will come from wherever this packet goes, hence !dir */ @@ -89,11 +93,23 @@ static unsigned int nf_nat_ftp(struct sk_buff *skb, * this one. */ exp->expectfn =3D nf_nat_follow_master; =20 - min =3D ntohs(exp->saved_proto.tcp.port); - max =3D 65535; + /* Avoid applying nat->range to the reply direction */ + if (!exp->dir || !nat->range_info.min_proto.all || !nat->range_info.max= _proto.all) { + min =3D ntohs(exp->saved_proto.tcp.port); + max =3D 65535; + } else { + min =3D ntohs(nat->range_info.min_proto.all); + max =3D ntohs(nat->range_info.max_proto.all); + if (unlikely(max < min)) + swap(max, min); + } =20 /* Try to get same port */ - ret =3D nf_ct_expect_related(exp, 0); + ret =3D -1; + port =3D ntohs(exp->saved_proto.tcp.port); + if (min < port && port < max) { + ret =3D nf_ct_expect_related(exp, 0); + } =20 /* if same port is not in range or available, try to change it. */ if (ret !=3D 0) { diff --git a/net/netfilter/nf_nat_helper.c b/net/netfilter/nf_nat_helper.= c index a263505455fc..718fc423bc44 100644 --- a/net/netfilter/nf_nat_helper.c +++ b/net/netfilter/nf_nat_helper.c @@ -188,6 +188,16 @@ void nf_nat_follow_master(struct nf_conn *ct, range.flags =3D NF_NAT_RANGE_MAP_IPS; range.min_addr =3D range.max_addr =3D ct->master->tuplehash[!exp->dir].tuple.dst.u3; + if (!exp->dir) { + struct nf_conn_nat *nat =3D nfct_nat(exp->master); + + if (nat && nat->range_info.min_proto.all && + nat->range_info.max_proto.all) { + range.min_proto =3D nat->range_info.min_proto; + range.max_proto =3D nat->range_info.max_proto; + range.flags |=3D NF_NAT_RANGE_PROTO_SPECIFIED; + } + } nf_nat_setup_info(ct, &range, NF_NAT_MANIP_SRC); =20 /* For DST manip, map port here to where it's expected. */ --=20 2.33.0