From patchwork Mon May 6 08:00:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antony Antony X-Patchwork-Id: 13655035 Received: from a.mx.secunet.com (a.mx.secunet.com [62.96.220.36]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D7A35140E40; Mon, 6 May 2024 08:00:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.96.220.36 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714982455; cv=none; b=svXmpL6/NU5mZ2A98QXhoVg3aSTiU+R5tq+GaGJNJEF9XBE5Nn8OZ4S5cMb/n3SM5MXpI6QCDSfQJvcys8SuVpdIBEgoZcX/WuHgicRt/B1ODLxVLe9XLewWJypCFhNbiHjBo9Ta/H5mFA1YycNapDCig5Bvv3v2HK0CjsjiYSw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714982455; c=relaxed/simple; bh=KUz72Jz3RA6f8g5ODmR/AHRMyPwA/99eRXklFzCM1AY=; h=Date:From:To:CC:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=RVTBZ3WwazoItNAztBt+/Q4i3qO9cmVGY0Mtdv3eBopaDkAYmzmXnTclOq6X7aQ+h+0UJv/d3zjzI+oqQkr0dvHLHuYnaH9H1w8xagyLceJoo20lpvo/24Qd62Q2fEPJ1nDDqZ+MNexPbqHiT+g/WCmCtBgRDaPWBEDuIYf8Xu8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=secunet.com; spf=pass smtp.mailfrom=secunet.com; dkim=pass (2048-bit key) header.d=secunet.com header.i=@secunet.com header.b=EmtqO/ZV; arc=none smtp.client-ip=62.96.220.36 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=secunet.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=secunet.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=secunet.com header.i=@secunet.com header.b="EmtqO/ZV" Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id CBE2C2074A; Mon, 6 May 2024 10:00:50 +0200 (CEST) X-Virus-Scanned: by secunet Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id gBfQ50x6JiAh; Mon, 6 May 2024 10:00:47 +0200 (CEST) Received: from mailout2.secunet.com (mailout2.secunet.com [62.96.220.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id EA0C1201A0; Mon, 6 May 2024 10:00:46 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 a.mx.secunet.com EA0C1201A0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=secunet.com; s=202301; t=1714982447; bh=lSEHGladzuqmKPIEerNtXlNa4toMQIllV18os6y7qLI=; h=Date:From:To:CC:Subject:Reply-To:References:In-Reply-To:From; b=EmtqO/ZVDFhXRRJ+b6bM3vLsVQxQc6CcTS+Bv6I274LYlaD7cuKJSdAlScY4e93kU RoTZLBy+n4+MeE299do3jfMEIcvPc1r7SWAtQ/zx0QgEx3IioRBI0yV4HmQwb51MvW X2U4Ff9trH1gQMZRcHvsNt4GoWLvmDVNC+vC7CWOQRLO9UDozr3xWeXxX51BkuQD9O 8rXNRvPnBfV1U72lxAmO4pu8ahVbHQJPgJuvAgYNmApWkyTWopRGLVrugXGul5Ym4I 75sGDAF+WGyQFpA0bGrtEiSq06TODf7faNgFqKtZ04RdS7FlNOMHHosF6ZllEet89L U5APMMYBtvWVg== Received: from cas-essen-02.secunet.de (unknown [10.53.40.202]) by mailout2.secunet.com (Postfix) with ESMTP id DD09C80004A; Mon, 6 May 2024 10:00:46 +0200 (CEST) Received: from mbx-essen-01.secunet.de (10.53.40.197) by cas-essen-02.secunet.de (10.53.40.202) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Mon, 6 May 2024 10:00:46 +0200 Received: from moon.secunet.de (172.18.149.1) by mbx-essen-01.secunet.de (10.53.40.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Mon, 6 May 2024 10:00:46 +0200 Date: Mon, 6 May 2024 10:00:40 +0200 From: Antony Antony To: Jakub Kicinski , Steffen Klassert , , CC: "David S. Miller" , David Ahern , Eric Dumazet , Paolo Abeni , "Herbert Xu" , Antony Antony , Shuah Khan , Subject: [PATCH net-next v3 1/2] xfrm: fix source address in icmp error generation from IPsec gateway Message-ID: <14c03971406de4effc9cf2ef21cf3921bd8b662d.1714982035.git.antony.antony@secunet.com> Reply-To: References: Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: first-class Priority: normal Organization: secunet X-ClientProxiedBy: cas-essen-01.secunet.de (10.53.40.201) To mbx-essen-01.secunet.de (10.53.40.197) X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 When enabling support for XFRM lookup using reverse ICMP payload, we have identified an issue where the source address of the IPv4, e.g., "Destination Host Unreachable" message, is incorrect. The error message received by the sender appears to originate from a non-existing/unreachable host. IPv6 seems to behave correctly; respond with an existing source address from the gateway. Here is example of incorrect source address for ICMP error response. When sending a ping to an unreachable host, the sender would receive an ICMP unreachable response with a fake source address. Rather the address of the host that generated ICMP Unreachable message. This is confusing and incorrect. A fllow up commit adds this example as a test case. Example: ping -W 9 -w 5 -c 1 10.1.4.3 PING 10.1.4.3 (10.1.4.3) 56(84) bytes of data. From 10.1.4.3 icmp_seq=1 Destination Host Unreachable Notice : packet has the source address of the ICMP "Unreachable host!" This issue can be traced back to commit 415b3334a21a ("icmp: Fix regression in nexthop resolution during replies.") which introduced a change that copied the source address from the ICMP payload. This commit would force to use source address from the gatway/host. The ICMP error message source address correctly set from the host. After fixing: ping -W 5 -c 1 10.1.4.3 PING 10.1.4.3 (10.1.4.3) 56(84) bytes of data. From 10.1.3.2 icmp_seq=1 Destination Host Unreachable Here is an snippt to reporduce the issue. export AB="10.1" for i in 1 2 3 4 5; do h="host${i}" ip netns add ${h} ip -netns ${h} link set lo up ip netns exec ${h} sysctl -wq net.ipv4.ip_forward=1 if [ $i -lt 5 ]; then ip -netns ${h} link add eth0 type veth peer name eth10${i} ip -netns ${h} addr add "${AB}.${i}.1/24" dev eth0 ip -netns ${h} link set up dev eth0 fi done for i in 1 2 3 4 5; do h="host${i}" p=$((i - 1)) ph="host${p}" # connect to previous host if [ $i -gt 1 ]; then ip -netns ${ph} link set eth10${p} netns ${h} ip -netns ${h} link set eth10${p} name eth1 ip -netns ${h} link set up dev eth1 ip -netns ${h} addr add "${AB}.${p}.2/24" dev eth1 fi # add forward routes for k in $(seq ${i} $((5 - 1))); do ip -netns ${h} route 2>/dev/null | (grep "${AB}.${k}.0" 2>/dev/null) || \ ip -netns ${h} route add "${AB}.${k}.0/24" via "${AB}.${i}.2" 2>/dev/nul done # add reverse routes for k in $(seq 1 $((i - 2))); do ip -netns ${h} route 2>/dev/null | grep "${AB}.${k}.0" 2>/dev/null || \ ip -netns ${h} route add "${AB}.${k}.0/24" via "${AB}.${p}.1" 2>/dev/nul done done ip netns exec host1 ping -q -W 2 -w 1 -c 1 10.1.4.2 2>&1>/dev/null && echo "success 10.1.4.2 reachable" || echo "ERROR" ip netns exec host1 ping -W 9 -w 5 -c 1 10.1.4.3 || echo "note the source address of unreachble of gateway" ip -netns host1 route flush cache ip netns exec host3 nft add table inet filter ip netns exec host3 nft add chain inet filter FORWARD { type filter hook forward priority filter\; policy drop \; } ip netns exec host3 nft add rule inet filter FORWARD counter ip protocol icmp drop ip netns exec host3 nft add rule inet filter FORWARD counter ip protocol esp accept ip netns exec host3 nft add rule inet filter FORWARD counter drop ip -netns host2 xfrm policy add src 10.1.1.0/24 dst 10.1.4.0/24 dir out \ flag icmp tmpl src 10.1.2.1 dst 10.1.3.2 proto esp reqid 1 mode tunnel ip -netns host2 xfrm policy add src 10.1.4.0/24 dst 10.1.1.0/24 dir in \ tmpl src 10.1.3.2 dst 10.1.2.1 proto esp reqid 2 mode tunnel ip -netns host2 xfrm policy add src 10.1.4.0/24 dst 10.1.1.0/24 dir fwd \ flag icmp tmpl src 10.1.3.2 dst 10.1.2.1 proto esp reqid 2 mode tunnel ip -netns host2 xfrm state add src 10.1.2.1 dst 10.1.3.2 proto esp spi 1 \ reqid 1 replay-window 1 mode tunnel aead 'rfc4106(gcm(aes))' \ 0x1111111111111111111111111111111111111111 96 \ sel src 10.1.1.0/24 dst 10.1.4.0/24 ip -netns host2 xfrm state add src 10.1.3.2 dst 10.1.2.1 proto esp spi 2 \ flag icmp reqid 2 replay-window 10 mode tunnel aead 'rfc4106(gcm(aes))' \ 0x2222222222222222222222222222222222222222 96 ip -netns host4 xfrm policy add src 10.1.4.0/24 dst 10.1.1.0/24 dir out \ flag icmp tmpl src 10.1.3.2 dst 10.1.2.1 proto esp reqid 1 mode tunnel ip -netns host4 xfrm policy add src 10.1.1.0/24 dst 10.1.4.0/24 dir in \ tmpl src 10.1.2.1 dst 10.1.3.2 proto esp reqid 2 mode tunnel ip -netns host4 xfrm policy add src 10.1.1.0/24 dst 10.1.4.0/24 dir fwd \ flag icmp tmpl src 10.1.2.1 dst 10.1.3.2 proto esp reqid 2 mode tunnel ip -netns host4 xfrm state add src 10.1.3.2 dst 10.1.2.1 proto esp spi 2 \ reqid 1 replay-window 1 mode tunnel aead 'rfc4106(gcm(aes))' \ 0x2222222222222222222222222222222222222222 96 ip -netns host4 xfrm state add src 10.1.2.1 dst 10.1.3.2 proto esp spi 1 \ reqid 2 replay-window 20 flag icmp mode tunnel aead 'rfc4106(gcm(aes))' \ 0x1111111111111111111111111111111111111111 96 \ sel src 10.1.1.0/24 dst 10.1.4.0/24 ip netns exec host1 ping -W 5 -c 1 10.1.4.2 2>&1 > /dev/null && echo "" ip netns exec host1 ping -W 5 -c 1 10.1.4.3 || echo "note source address of gateway 10.1.3.2" Again before the fix ping -W 5 -c 1 10.1.4.3 From 10.1.4.3 icmp_seq=1 Destination Host Unreachable After the fix From 10.1.3.2 icmp_seq=1 Destination Host Unreachable Signed-off-by: Antony Antony Acked-by: Tobias Brunner --- net/ipv4/icmp.c | 1 - 1 file changed, 1 deletion(-) diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 207482d30dc7..317ad5165408 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -558,7 +558,6 @@ static struct rtable *icmp_route_lookup(struct net *net, rt2 = dst_rtable(dst2); if (!IS_ERR(dst2)) { dst_release(&rt->dst); - memcpy(fl4, &fl4_dec, sizeof(*fl4)); rt = rt2; } else if (PTR_ERR(dst2) == -EPERM) { if (rt)