From patchwork Mon Jul 19 01:21:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cole Dishington X-Patchwork-Id: 480209 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 14897C636CB for ; Mon, 19 Jul 2021 01:22:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F2C9B61166 for ; Mon, 19 Jul 2021 01:22:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234124AbhGSBZF (ORCPT ); Sun, 18 Jul 2021 21:25:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52124 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234116AbhGSBZD (ORCPT ); Sun, 18 Jul 2021 21:25:03 -0400 Received: from gate2.alliedtelesis.co.nz (gate2.alliedtelesis.co.nz [IPv6:2001:df5:b000:5::4]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 734F3C061765 for ; Sun, 18 Jul 2021 18:22:04 -0700 (PDT) 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 B9A29891AC; Mon, 19 Jul 2021 13:21:59 +1200 (NZST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alliedtelesis.co.nz; s=mail181024; t=1626657719; bh=tugs+RN3zWERTiSWA0QB9e8+5bb3s257u6SSDPeBovM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XBFlKluL3HusTey4mkHDNVU8iSaVaSCoR/FGZ9HS3+mxgUMXDlNY3Aq4cYHPFFf8n ArsSa6/EejoIdZtWWbxCG3dA/dudRAg2luZYNGsjUqar6NxcK2GuYGbWa1zH++wEwh xM+BtM6CuMzcNnQuVGg5QmDx2zPajJR56/5E9VCiqiGBzlqWC/jVnggk+0DNnQLEqL SsnGCw1x9Clnquob+IisgEZJZHE0yhbsvr8RBBgHyDewym3FyG4+VgZ6ex4ZIX0UTe 6qXJKh1xgmqdPKNshl3yxC53Pm9Fm5vkSVu+tzskkS+DhmzcbG/b1AjvOnK5AKUH+x EmIgnmQ4xCZnA== 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, 19 Jul 2021 13:21:59 +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 5FBE213EE1E; Mon, 19 Jul 2021 13:21:59 +1200 (NZST) Received: by coled-dl.ws.atlnz.lc (Postfix, from userid 1801) id 577CC2428CC; Mon, 19 Jul 2021 13:21:59 +1200 (NZST) From: Cole Dishington To: pablo@netfilter.org Cc: kadlec@netfilter.org, fw@strlen.de, davem@davemloft.net, kuba@kernel.org, shuah@kernel.org, linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, Cole Dishington , Anthony Lineham , Scott Parlane , Blair Steven Subject: [PATCH 2/3] net: netfilter: Add RFC-7597 Section 5.1 PSID support Date: Mon, 19 Jul 2021 13:21:50 +1200 Message-Id: <20210719012151.28324-1-Cole.Dishington@alliedtelesis.co.nz> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210716151833.GD9904@breakpoint.cc> References: <20210716151833.GD9904@breakpoint.cc> MIME-Version: 1.0 X-SEG-SpamProfiler-Analysis: v=2.3 cv=Sr3uF8G0 c=1 sm=1 tr=0 a=KLBiSEs5mFS1a/PbTCJxuA==:117 a=e_q4qTt1xDgA:10 a=xOT0nC9th1TpZTiSAT0A:9 X-SEG-SpamProfiler-Score: 0 x-atlnz-ls: pat Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Adds support for masquerading into a smaller subset of ports - defined by the PSID values from RFC-7597 Section 5.1. This is part of the support for MAP-E and Lightweight 4over6, which allows multiple devices to share an IPv4 address by splitting the L4 port / id into ranges. Co-developed-by: Anthony Lineham Signed-off-by: Anthony Lineham Co-developed-by: Scott Parlane Signed-off-by: Scott Parlane Signed-off-by: Blair Steven Signed-off-by: Cole Dishington --- Notes: Thanks for time reviewing! Changes in v5: - Add WARN_ON_ONCE for invalid value of range->base. net/netfilter/nf_nat_core.c | 39 +++++++++++++++++++++++++++---- net/netfilter/nf_nat_masquerade.c | 27 +++++++++++++++++++-- 2 files changed, 60 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 7de595ead06a..4a9448684504 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -195,13 +195,36 @@ static bool nf_nat_inet_in_range(const struct nf_conntrack_tuple *t, static bool l4proto_in_range(const struct nf_conntrack_tuple *tuple, enum nf_nat_manip_type maniptype, const union nf_conntrack_man_proto *min, - const union nf_conntrack_man_proto *max) + const union nf_conntrack_man_proto *max, + const union nf_conntrack_man_proto *base, + bool is_psid) { __be16 port; + u16 psid, psid_mask, offset_mask; + + /* In this case we are in PSID mode, avoid checking all ranges by computing bitmasks */ + if (is_psid) { + u16 power_j = ntohs(max->all) - ntohs(min->all) + 1; + u32 offset = ntohs(base->all); + u16 power_a; + + if (offset == 0) + offset = 1 << 16; + + power_a = (1 << 16) / offset; + offset_mask = (power_a - 1) * offset; + psid_mask = ((offset / power_j) << 1) - 1; + psid = ntohs(min->all) & psid_mask; + } switch (tuple->dst.protonum) { case IPPROTO_ICMP: case IPPROTO_ICMPV6: + if (is_psid) { + return (offset_mask == 0 || + (ntohs(tuple->src.u.icmp.id) & offset_mask) != 0) && + ((ntohs(tuple->src.u.icmp.id) & psid_mask) == psid); + } return ntohs(tuple->src.u.icmp.id) >= ntohs(min->icmp.id) && ntohs(tuple->src.u.icmp.id) <= ntohs(max->icmp.id); case IPPROTO_GRE: /* all fall though */ @@ -215,6 +238,10 @@ static bool l4proto_in_range(const struct nf_conntrack_tuple *tuple, else port = tuple->dst.u.all; + if (is_psid) { + return (offset_mask == 0 || (ntohs(port) & offset_mask) != 0) && + ((ntohs(port) & psid_mask) == psid); + } return ntohs(port) >= ntohs(min->all) && ntohs(port) <= ntohs(max->all); default: @@ -239,7 +266,8 @@ static int in_range(const struct nf_conntrack_tuple *tuple, return 1; return l4proto_in_range(tuple, NF_NAT_MANIP_SRC, - &range->min_proto, &range->max_proto); + &range->min_proto, &range->max_proto, &range->base_proto, + range->flags & NF_NAT_RANGE_PSID); } static inline int @@ -532,8 +560,11 @@ get_unique_tuple(struct nf_conntrack_tuple *tuple, if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) { if (!(range->flags & NF_NAT_RANGE_PROTO_OFFSET) && l4proto_in_range(tuple, maniptype, - &range->min_proto, - &range->max_proto) && + &range->min_proto, + &range->max_proto, + &range->base_proto, + range->flags & + NF_NAT_RANGE_PSID) && (range->min_proto.all == range->max_proto.all || !nf_nat_used_tuple(tuple, ct))) return; diff --git a/net/netfilter/nf_nat_masquerade.c b/net/netfilter/nf_nat_masquerade.c index 8e8a65d46345..dea6106f1699 100644 --- a/net/netfilter/nf_nat_masquerade.c +++ b/net/netfilter/nf_nat_masquerade.c @@ -55,8 +55,31 @@ nf_nat_masquerade_ipv4(struct sk_buff *skb, unsigned int hooknum, newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS; newrange.min_addr.ip = newsrc; newrange.max_addr.ip = newsrc; - newrange.min_proto = range->min_proto; - newrange.max_proto = range->max_proto; + + if (range->flags & NF_NAT_RANGE_PSID) { + u16 base = ntohs(range->base_proto.all); + u16 min = ntohs(range->min_proto.all); + u16 off = 0; + + /* xtables should stop base > 2^15 by enforcement of + * 0 <= offset_len < 16 argument, with offset_len=0 + * as a special case inwhich base=0. + */ + if (WARN_ON_ONCE(base > (1 << 15))) + return NF_DROP; + + /* If offset=0, port range is in one contiguous block */ + if (base) + off = prandom_u32() % (((1 << 16) / base) - 1); + + newrange.min_proto.all = htons(min + base * off); + newrange.max_proto.all = htons(ntohs(newrange.min_proto.all) + ntohs(range->max_proto.all) - min); + newrange.base_proto = range->base_proto; + newrange.flags = newrange.flags | NF_NAT_RANGE_PROTO_SPECIFIED; + } else { + newrange.min_proto = range->min_proto; + newrange.max_proto = range->max_proto; + } /* Hand modified range to generic setup. */ return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_SRC);