From patchwork Thu Mar 25 17:24:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Abeni X-Patchwork-Id: 12164649 X-Patchwork-Delegate: kuba@kernel.org 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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 152F1C433E0 for ; Thu, 25 Mar 2021 17:25:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE2A661A2C for ; Thu, 25 Mar 2021 17:25:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230100AbhCYRYs (ORCPT ); Thu, 25 Mar 2021 13:24:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:58234 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229984AbhCYRYc (ORCPT ); Thu, 25 Mar 2021 13:24:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616693071; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6ILxEghaIijc/ZBEYoThX2CXg3jWa3dtNjMIooaRA6c=; b=PeSKF8EaLJ0sRTrUs9r+5sWI7Rh9NbYDiPJbsB+s4J45vvTQce747SHpsteqCIrd4bnCoO I4xnLpfevefGTDtHBZJGKJSJ+3ptc/u9k/6oo6RlrD0dedQDFjyTUCTT+QX/u3CkrKnUNo it32NkvhxKZHDaNI94QRFHRwcy+/g4k= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-525-IQOOhvi3OU-olXng0Ox0Aw-1; Thu, 25 Mar 2021 13:24:27 -0400 X-MC-Unique: IQOOhvi3OU-olXng0Ox0Aw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9A0E783DD33; Thu, 25 Mar 2021 17:24:25 +0000 (UTC) Received: from gerbillo.redhat.com (ovpn-113-211.ams2.redhat.com [10.36.113.211]) by smtp.corp.redhat.com (Postfix) with ESMTP id B1C11794A0; Thu, 25 Mar 2021 17:24:23 +0000 (UTC) From: Paolo Abeni To: netdev@vger.kernel.org Cc: "David S. Miller" , Jakub Kicinski , Steffen Klassert , Willem de Bruijn , Alexander Lobakin Subject: [PATCH net-next v2 2/8] udp: skip L4 aggregation for UDP tunnel packets Date: Thu, 25 Mar 2021 18:24:01 +0100 Message-Id: <400ebbc750178183155a9419cd5c3d32f53abcef.1616692794.git.pabeni@redhat.com> In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org If NETIF_F_GRO_FRAGLIST or NETIF_F_GRO_UDP_FWD are enabled, and there are UDP tunnels available in the system, udp_gro_receive() could end-up doing L4 aggregation (either SKB_GSO_UDP_L4 or SKB_GSO_FRAGLIST) at the outer UDP tunnel level for packets effectively carrying and UDP tunnel header. That could cause inner protocol corruption. If e.g. the relevant packets carry a vxlan header, different vxlan ids will be ignored/ aggregated to the same GSO packet. Inner headers will be ignored, too, so that e.g. TCP over vxlan push packets will be held in the GRO engine till the next flush, etc. Just skip the SKB_GSO_UDP_L4 and SKB_GSO_FRAGLIST code path if the current packet could land in a UDP tunnel, and let udp_gro_receive() do GRO via udp_sk(sk)->gro_receive. The check implemented in this patch is broader than what is strictly needed, as the existing UDP tunnel could be e.g. configured on top of a different device: we could end-up skipping GRO at-all for some packets. Anyhow, the latter is a very thin corner case and covering it would add quite a bit of complexity. v1 -> v2: - hopefully clarify the commit message Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Fixes: 36707061d6ba ("udp: allow forwarding of plain (non-fraglisted) UDP GRO packets") Signed-off-by: Paolo Abeni Reviewed-by: Willem de Bruijn --- net/ipv4/udp_offload.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index c5b4b586570fe..25134a3548e99 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -515,21 +515,24 @@ struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, unsigned int off = skb_gro_offset(skb); int flush = 1; + /* we can do L4 aggregation only if the packet can't land in a tunnel + * otherwise we could corrupt the inner stream + */ NAPI_GRO_CB(skb)->is_flist = 0; - if (skb->dev->features & NETIF_F_GRO_FRAGLIST) - NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1; + if (!sk || !udp_sk(sk)->gro_receive) { + if (skb->dev->features & NETIF_F_GRO_FRAGLIST) + NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled : 1; - if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || - (sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) { - pp = call_gro_receive(udp_gro_receive_segment, head, skb); + if ((!sk && (skb->dev->features & NETIF_F_GRO_UDP_FWD)) || + (sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) + pp = call_gro_receive(udp_gro_receive_segment, head, skb); return pp; } - if (!sk || NAPI_GRO_CB(skb)->encap_mark || + if (NAPI_GRO_CB(skb)->encap_mark || (uh->check && skb->ip_summed != CHECKSUM_PARTIAL && NAPI_GRO_CB(skb)->csum_cnt == 0 && - !NAPI_GRO_CB(skb)->csum_valid) || - !udp_sk(sk)->gro_receive) + !NAPI_GRO_CB(skb)->csum_valid)) goto out; /* mark that this skb passed once through the tunnel gro layer */