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=-3.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=no 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 30B82C43603 for ; Wed, 18 Dec 2019 11:53:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EECF3206E0 for ; Wed, 18 Dec 2019 11:53:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YuOoAmM4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726930AbfLRLxn (ORCPT ); Wed, 18 Dec 2019 06:53:43 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:46721 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726856AbfLRLxn (ORCPT ); Wed, 18 Dec 2019 06:53:43 -0500 Received: by mail-pf1-f193.google.com with SMTP id y14so1063207pfm.13 for ; Wed, 18 Dec 2019 03:53:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=9sPANbPAl+E3uP3x6sXINIt01H+sSnhfDdo/0WQiL+w=; b=YuOoAmM4l0NlLsXoO1UflGRHo18DIb+Tjj6z0TyhXGXzet/UmVkeoCefO8Px7qTyZk rIR0fN5Y7b4K3wRvZu4PP2vCx3zrInMKefJjdC6J3jzbuczAtQsAHiXHu++5gJ+CDDj9 nBjYh9go9k/XRUJcQLTrTEsgC9sff957rr9xlVylLt8NVkW9oEctqPbmiu1eleIpUgbx IhQdvNaxOD5v8lG0J5MThLM41Cys5zEfNPjaFuXZTI4zJ/vzyOnnIKPRUdd80f2jBlFz 0q71oiXJxk7xjs5/eMn+aFqmW3Myet/bgljk3A1FowAkjGCdaWAwE0b8iQqL0cngLVmu qTdQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=9sPANbPAl+E3uP3x6sXINIt01H+sSnhfDdo/0WQiL+w=; b=JQ/1LsYnGaEA/rCDI130FRx/BDekeRB9F58TEJ/aNN+Be4jZmVHMCD+oUrW9T4nhpi qMvKG75hu74up+87+kn7uTXufu6386u0/6xjUlBSYLCmyTXF+QXqkbK0w4XQ1Fn+yyIy jbjxrqMY/0yodDH7omhlRaGQ5NAwtR+nvfQrbPoMpZBCn+ZcCPw6zmUEFNe2cIbzIjU+ D7ovT4s0Htq/iSO1FQKkszVq41syktFTm4jkMxV4I23qu7y09txg8iuoHtIM7E0VTh04 Y5kW9cnZlm35NityvR1/xiaIXMEy8RRmNe41W5Z2jiZuFtyS2ZHuigbvMRyzJILFFp/z W4lg== X-Gm-Message-State: APjAAAVoRC8P2E4Hka4EE3b2hnYBnr9uT4ANF2KRTiDGg+iJhXAFapHk B335099pT/VpWnQtRIEGH1FdbyKLaDE= X-Google-Smtp-Source: APXvYqxQX8l03OjfxuVXMrcngHYd+N9FVjYSROI7/F9aLM0wT1EVjohqXeCETL4Bu6JTOVC0swyW1A== X-Received: by 2002:a63:1756:: with SMTP id 22mr2655055pgx.109.1576670021979; Wed, 18 Dec 2019 03:53:41 -0800 (PST) Received: from dhcp-12-139.nay.redhat.com ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id x33sm2961067pga.86.2019.12.18.03.53.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Dec 2019 03:53:41 -0800 (PST) From: Hangbin Liu To: netdev@vger.kernel.org Cc: Julian Anastasov , Marcelo Ricardo Leitner , David Ahern , Eric Dumazet , Guillaume Nault , David Miller , Pablo Neira , Stephen Hemminger , Alexey Kodanev , Hangbin Liu Subject: [PATCH net-next 0/8] disable neigh update for tunnels during pmtu update Date: Wed, 18 Dec 2019 19:53:05 +0800 Message-Id: <20191218115313.19352-1-liuhangbin@gmail.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20191203021137.26809-1-liuhangbin@gmail.com> References: <20191203021137.26809-1-liuhangbin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When we setup a pair of gretap, ping each other and create neighbour cache. Then delete and recreate one side. We will never be able to ping6 to the new created gretap. The reason is when we ping6 remote via gretap, we will call like gre_tap_xmit() - ip_tunnel_xmit() - tnl_update_pmtu() - skb_dst_update_pmtu() - ip6_rt_update_pmtu() - __ip6_rt_update_pmtu() - dst_confirm_neigh() - ip6_confirm_neigh() - __ipv6_confirm_neigh() - n->confirmed = now As the confirmed time updated, in neigh_timer_handler() the check for NUD_DELAY confirm time will pass and the neigh state will back to NUD_REACHABLE. So the old/wrong mac address will be used again. If we do not update the confirmed time, the neigh state will go to neigh->nud_state = NUD_PROBE; then go to NUD_FAILED and re-create the neigh later, which is what IPv4 does. We couldn't remove the ip6_confirm_neigh() directly as we still need it for TCP flows. To fix it, we have to pass a bool parameter to dst_ops.update_pmtu() and only disable neighbor update for tunnels. v2: remove dst_confirm_neigh directly v3: add bool confirm_neigh parameter for all dst_ops.update_pmtu and disable neigh update on each tunnel device. --- Reproducer: #!/bin/bash set -x ip -a netns del modprobe -r veth modprobe -r bridge ip netns add ha ip netns add hb ip link add br0 type bridge ip link set br0 up ip link add br_ha type veth peer name veth0 netns ha ip link add br_hb type veth peer name veth0 netns hb ip link set br_ha up ip link set br_hb up ip link set br_ha master br0 ip link set br_hb master br0 ip netns exec ha ip link set veth0 up ip netns exec hb ip link set veth0 up ip netns exec ha ip addr add 192.168.0.1/24 dev veth0 ip netns exec hb ip addr add 192.168.0.2/24 dev veth0 ip netns exec ha ip link add gretap1 type gretap local 192.168.0.1 remote 192.168.0.2 ip netns exec ha ip link set gretap1 up ip netns exec ha ip addr add 1.1.1.1/24 dev gretap1 ip netns exec ha ip addr add 1111::1/64 dev gretap1 ip netns exec hb ip link add gretap1 type gretap local 192.168.0.2 remote 192.168.0.1 ip netns exec hb ip link set gretap1 up ip netns exec hb ip addr add 1.1.1.2/24 dev gretap1 ip netns exec hb ip addr add 1111::2/64 dev gretap1 ip netns exec ha ping 1.1.1.2 -c 4 ip netns exec ha ping6 1111::2 -c 4 sleep 30 # recreate gretap ip netns exec hb ip link del gretap1 ip netns exec hb ip link add gretap1 type gretap local 192.168.0.2 remote 192.168.0.1 ip netns exec hb ip link set gretap1 up ip netns exec hb ip addr add 1.1.1.2/24 dev gretap1 ip netns exec hb ip addr add 1111::2/64 dev gretap1 ip netns exec hb ip link show dev gretap1 ip netns exec ha ip neigh show dev gretap1 ip netns exec ha ping 1.1.1.2 -c 4 ip netns exec ha ping6 1111::2 -c 4 ip netns exec ha ip neigh show dev gretap1 sleep 10 ip netns exec ha ip neigh show dev gretap1 ip netns exec ha ping 1.1.1.2 -c 4 ip netns exec ha ping6 1111::2 -c 4 ip netns exec ha ip neigh show dev gretap1 --- Hangbin Liu (8): net: add bool confirm_neigh parameter for dst_ops.update_pmtu ip6_gre: do not confirm neighbor when do pmtu update gtp: do not confirm neighbor when do pmtu update net/dst: add new function skb_dst_update_pmtu_no_confirm tunnel: do not confirm neighbor when do pmtu update vti: do not confirm neighbor when do pmtu update sit: do not confirm neighbor when do pmtu update net/dst: do not confirm neighbor for vxlan and geneve pmtu update drivers/net/gtp.c | 2 +- include/net/dst.h | 13 +++++++++++-- include/net/dst_ops.h | 3 ++- net/bridge/br_nf_core.c | 3 ++- net/decnet/dn_route.c | 6 ++++-- net/ipv4/inet_connection_sock.c | 2 +- net/ipv4/ip_tunnel.c | 2 +- net/ipv4/ip_vti.c | 2 +- net/ipv4/route.c | 9 ++++++--- net/ipv4/xfrm4_policy.c | 5 +++-- net/ipv6/inet6_connection_sock.c | 2 +- net/ipv6/ip6_gre.c | 2 +- net/ipv6/ip6_tunnel.c | 4 ++-- net/ipv6/ip6_vti.c | 2 +- net/ipv6/route.c | 22 +++++++++++++++------- net/ipv6/sit.c | 2 +- net/ipv6/xfrm6_policy.c | 5 +++-- net/netfilter/ipvs/ip_vs_xmit.c | 2 +- net/sctp/transport.c | 2 +- 19 files changed, 58 insertions(+), 32 deletions(-) -- 2.19.2