From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 D6A45253AC for ; Tue, 18 Jul 2023 10:50:48 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A1FF19A for ; Tue, 18 Jul 2023 03:50:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1689677446; 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; bh=6yXJAnfxZ/NRetTVtpdnbTXI4qx7YJvv56r/PUuKy3A=; b=WI/9DTdElV2ZNCH5xUy7PGzsJJgddJ15NYkMD0CN4cYmnXqxQwceCtMV3tYiGQdNOUso12 iCl/3vk8+3Adj70DjW6KgR/VdJF1wuAVBojv4aJbEbLUYWTe0m9Ha5Jyw6613+AxS/IOvx 72UWJrGZg30b6sgk7+mv1NWKcQoen0M= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-151-huLhAzHIPcmpJm6-V_V1Sg-1; Tue, 18 Jul 2023 06:50:41 -0400 X-MC-Unique: huLhAzHIPcmpJm6-V_V1Sg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id ACC61858290; Tue, 18 Jul 2023 10:50:40 +0000 (UTC) Received: from griffin.upir.cz (unknown [10.45.225.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id F1EA8C2C8C4; Tue, 18 Jul 2023 10:50:39 +0000 (UTC) From: Jiri Benc To: netdev@vger.kernel.org Cc: Jesse Brandeburg , Tony Nguyen Subject: [PATCH net] vxlan: calculate correct header length for GPE Date: Tue, 18 Jul 2023 12:50:13 +0200 Message-Id: <0699747bc9bd7aaf7dc87efd33aa6b95de7d793e.1689677201.git.jbenc@redhat.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net VXLAN-GPE does not add an extra inner Ethernet header. Take that into account when calculating header length. This causes problems in skb_tunnel_check_pmtu, where incorrect PMTU is cached. If the VXLAN-GPE interface has MTU 1464 set (with the underlying interface having the usual MTU of 1500), a TCP stream sent over the tunnel is first segmented to 1514 byte frames only to be immediatelly followed by a resend with 1500 bytes frames, before the other side even has a chance to ack them. Fixes: e1e5314de08ba ("vxlan: implement GPE") Signed-off-by: Jiri Benc --- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 2 +- drivers/net/vxlan/vxlan_core.c | 23 ++++++++----------- include/net/vxlan.h | 13 +++++++---- 3 files changed, 20 insertions(+), 18 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 1726297f2e0d..8eb9839a3ca6 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -8479,7 +8479,7 @@ static void ixgbe_atr(struct ixgbe_ring *ring, struct ixgbe_adapter *adapter = q_vector->adapter; if (unlikely(skb_tail_pointer(skb) < hdr.network + - VXLAN_HEADROOM)) + vxlan_headroom(0))) return; /* verify the port is recognized as VXLAN */ diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index 78744549c1b3..42be8a26c171 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -2516,7 +2516,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, } ndst = &rt->dst; - err = skb_tunnel_check_pmtu(skb, ndst, VXLAN_HEADROOM, + err = skb_tunnel_check_pmtu(skb, ndst, vxlan_headroom(flags & VXLAN_F_GPE), netif_is_any_bridge_port(dev)); if (err < 0) { goto tx_error; @@ -2577,7 +2577,8 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, goto out_unlock; } - err = skb_tunnel_check_pmtu(skb, ndst, VXLAN6_HEADROOM, + err = skb_tunnel_check_pmtu(skb, ndst, + vxlan_headroom((flags & VXLAN_F_GPE) | VXLAN_F_IPV6), netif_is_any_bridge_port(dev)); if (err < 0) { goto tx_error; @@ -2989,14 +2990,12 @@ static int vxlan_change_mtu(struct net_device *dev, int new_mtu) struct vxlan_rdst *dst = &vxlan->default_dst; struct net_device *lowerdev = __dev_get_by_index(vxlan->net, dst->remote_ifindex); - bool use_ipv6 = !!(vxlan->cfg.flags & VXLAN_F_IPV6); /* This check is different than dev->max_mtu, because it looks at * the lowerdev->mtu, rather than the static dev->max_mtu */ if (lowerdev) { - int max_mtu = lowerdev->mtu - - (use_ipv6 ? VXLAN6_HEADROOM : VXLAN_HEADROOM); + int max_mtu = lowerdev->mtu - vxlan_headroom(vxlan->cfg.flags); if (new_mtu > max_mtu) return -EINVAL; } @@ -3644,11 +3643,11 @@ static void vxlan_config_apply(struct net_device *dev, struct vxlan_dev *vxlan = netdev_priv(dev); struct vxlan_rdst *dst = &vxlan->default_dst; unsigned short needed_headroom = ETH_HLEN; - bool use_ipv6 = !!(conf->flags & VXLAN_F_IPV6); int max_mtu = ETH_MAX_MTU; + u32 flags = conf->flags; if (!changelink) { - if (conf->flags & VXLAN_F_GPE) + if (flags & VXLAN_F_GPE) vxlan_raw_setup(dev); else vxlan_ether_setup(dev); @@ -3673,8 +3672,7 @@ static void vxlan_config_apply(struct net_device *dev, dev->needed_tailroom = lowerdev->needed_tailroom; - max_mtu = lowerdev->mtu - (use_ipv6 ? VXLAN6_HEADROOM : - VXLAN_HEADROOM); + max_mtu = lowerdev->mtu - vxlan_headroom(flags); if (max_mtu < ETH_MIN_MTU) max_mtu = ETH_MIN_MTU; @@ -3685,10 +3683,9 @@ static void vxlan_config_apply(struct net_device *dev, if (dev->mtu > max_mtu) dev->mtu = max_mtu; - if (use_ipv6 || conf->flags & VXLAN_F_COLLECT_METADATA) - needed_headroom += VXLAN6_HEADROOM; - else - needed_headroom += VXLAN_HEADROOM; + if (flags & VXLAN_F_COLLECT_METADATA) + flags |= VXLAN_F_IPV6; + needed_headroom += vxlan_headroom(flags); dev->needed_headroom = needed_headroom; memcpy(&vxlan->cfg, conf, sizeof(*conf)); diff --git a/include/net/vxlan.h b/include/net/vxlan.h index 0be91ca78d3a..1648240c9668 100644 --- a/include/net/vxlan.h +++ b/include/net/vxlan.h @@ -386,10 +386,15 @@ static inline netdev_features_t vxlan_features_check(struct sk_buff *skb, return features; } -/* IP header + UDP + VXLAN + Ethernet header */ -#define VXLAN_HEADROOM (20 + 8 + 8 + 14) -/* IPv6 header + UDP + VXLAN + Ethernet header */ -#define VXLAN6_HEADROOM (40 + 8 + 8 + 14) +static inline int vxlan_headroom(u32 flags) +{ + /* VXLAN: IP4/6 header + UDP + VXLAN + Ethernet header */ + /* VXLAN-GPE: IP4/6 header + UDP + VXLAN */ + return (flags & VXLAN_F_IPV6 ? sizeof(struct ipv6hdr) : + sizeof(struct iphdr)) + + sizeof(struct udphdr) + sizeof(struct vxlanhdr) + + (flags & VXLAN_F_GPE ? 0 : ETH_HLEN); +} static inline struct vxlanhdr *vxlan_hdr(struct sk_buff *skb) { -- 2.39.2