From patchwork Thu Mar 10 00:28:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 12775726 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AF33C433FE for ; Thu, 10 Mar 2022 00:29:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239016AbiCJAaP (ORCPT ); Wed, 9 Mar 2022 19:30:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238997AbiCJAaI (ORCPT ); Wed, 9 Mar 2022 19:30:08 -0500 Received: from mail-pf1-x430.google.com (mail-pf1-x430.google.com [IPv6:2607:f8b0:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE113125508 for ; Wed, 9 Mar 2022 16:29:06 -0800 (PST) Received: by mail-pf1-x430.google.com with SMTP id f8so3682052pfj.5 for ; Wed, 09 Mar 2022 16:29:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Eo6Ay78UtfJaj+pFT4IeJlC6FzfAL4dcL6hsPGiyVns=; b=jxwUg1jkJIqAKtEQs969FopKEljV2Aekk+t/yW/sT4rcaKvmD1rXscS8PYr1gmAfqB zlDZvaqfQcUjXSZ6Q2Gapqs8XPGqj6ABeqmvPM9ruzcrvPCp18bv92rNTyEOhcc0jsuw 68PETfZ8oX+eYOUE7oFAu0M2iaE6k46LxPKWepPqZI9+xxswmtuys6qllMwkft7lcabq 7PYOrrtegQVcvB+MlJ42xFUHDQvmjV85bLZi+XvJqptk8dOyvI4qwUkjemd2V22tz30A 3eLfGFFes6apJiandCuyiHnFJ5TMMtRy6SN83UBJZ6X5uEbl1wgrf2QnRHoqUbg5RPgj IheQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Eo6Ay78UtfJaj+pFT4IeJlC6FzfAL4dcL6hsPGiyVns=; b=LC8uNdUMTc2vmpynAC2Kx4uaSj+u8C963UQ9HU5sAd+oQ8HJwUXRds1mjAAEh9II0w 1FjLZvrIfyPVzep/pYTrZhxHIO5IQd4VYZGL0i+2FlacSnM3lerczCUSF2i6XFuobDYo bPuKjDNVYrNO4G8GMrjavVf/BFrc+3FpOknUPme4lvFweAW1yFYlDYxE3cR1AIyf0iAg w6I4YoGRF0GO7cmTDQ9YSR7jc4Zz51/GBBdJhbWfVOOKOp2c5OrB8zOx/sciGErIQSWp WHVra6cAfxlzjtlBRoLUU7r/4YjDS7393cq+Tx3I0Y4y/gZRXPgX9lIQPeqDD2XJ6dSS BU4g== X-Gm-Message-State: AOAM531AIymQrEfvR4Gw/LI55r5Z/vA6us/V0O6ihj4oyJ9nwad6B4hY CvTCekWsdwjZkyRsgQ0/iFg= X-Google-Smtp-Source: ABdhPJyU8ZGLOvwCTqplPZTPek/L5cT7R9MVKmoPVf3csSH0wVbSfcUw6PiWoVkVNXfwXtZd6m7b9Q== X-Received: by 2002:a63:944:0:b0:374:5324:eea1 with SMTP id 65-20020a630944000000b003745324eea1mr1882891pgj.366.1646872146338; Wed, 09 Mar 2022 16:29:06 -0800 (PST) Received: from edumazet1.svl.corp.google.com ([2620:15c:2c4:201:c6c7:6f77:9634:183c]) by smtp.gmail.com with ESMTPSA id nv4-20020a17090b1b4400b001bf64a39579sm7557660pjb.4.2022.03.09.16.29.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Mar 2022 16:29:05 -0800 (PST) From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski Cc: netdev , Alexander Duyck , Coco Li , Eric Dumazet , Eric Dumazet Subject: [PATCH v3 net-next 08/14] ipv6: Add hop-by-hop header to jumbograms in ip6_output Date: Wed, 9 Mar 2022 16:28:40 -0800 Message-Id: <20220310002846.460907-9-eric.dumazet@gmail.com> X-Mailer: git-send-email 2.35.1.616.g0bdcbb4464-goog In-Reply-To: <20220310002846.460907-1-eric.dumazet@gmail.com> References: <20220310002846.460907-1-eric.dumazet@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Coco Li Instead of simply forcing a 0 payload_len in IPv6 header, implement RFC 2675 and insert a custom extension header. Note that only TCP stack is currently potentially generating jumbograms, and that this extension header is purely local, it wont be sent on a physical link. This is needed so that packet capture (tcpdump and friends) can properly dissect these large packets. Signed-off-by: Coco Li Signed-off-by: Eric Dumazet --- include/linux/ipv6.h | 1 + net/ipv6/ip6_output.c | 22 ++++++++++++++++++++-- 2 files changed, 21 insertions(+), 2 deletions(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 16870f86c74d3d1f5dfb7edac1e7db85f1ef6755..93b273db1c9926aba4199f486ce90778311916f5 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -144,6 +144,7 @@ struct inet6_skb_parm { #define IP6SKB_L3SLAVE 64 #define IP6SKB_JUMBOGRAM 128 #define IP6SKB_SEG6 256 +#define IP6SKB_FAKEJUMBO 512 }; #if defined(CONFIG_NET_L3_MASTER_DEV) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index e69fac576970a9b85fb68aa02822c0e2df67e1a2..941ceff83b616cec11c6bb7ccaf81bc041f8d9cc 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -180,7 +180,9 @@ static int __ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff #endif mtu = ip6_skb_dst_mtu(skb); - if (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)) + if (skb_is_gso(skb) && + !(IP6CB(skb)->flags & IP6SKB_FAKEJUMBO) && + !skb_gso_validate_network_len(skb, mtu)) return ip6_finish_output_gso_slowpath_drop(net, sk, skb, mtu); if ((skb->len > mtu && !skb_is_gso(skb)) || @@ -251,6 +253,8 @@ int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, struct dst_entry *dst = skb_dst(skb); struct net_device *dev = dst->dev; struct inet6_dev *idev = ip6_dst_idev(dst); + struct hop_jumbo_hdr *hop_jumbo; + int hoplen = sizeof(*hop_jumbo); unsigned int head_room; struct ipv6hdr *hdr; u8 proto = fl6->flowi6_proto; @@ -258,7 +262,7 @@ int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, int hlimit = -1; u32 mtu; - head_room = sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dev); + head_room = sizeof(struct ipv6hdr) + hoplen + LL_RESERVED_SPACE(dev); if (opt) head_room += opt->opt_nflen + opt->opt_flen; @@ -281,6 +285,20 @@ int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, &fl6->saddr); } + if (unlikely(seg_len > IPV6_MAXPLEN)) { + hop_jumbo = skb_push(skb, hoplen); + + hop_jumbo->nexthdr = proto; + hop_jumbo->hdrlen = 0; + hop_jumbo->tlv_type = IPV6_TLV_JUMBO; + hop_jumbo->tlv_len = 4; + hop_jumbo->jumbo_payload_len = htonl(seg_len + hoplen); + + proto = IPPROTO_HOPOPTS; + seg_len = 0; + IP6CB(skb)->flags |= IP6SKB_FAKEJUMBO; + } + skb_push(skb, sizeof(struct ipv6hdr)); skb_reset_network_header(skb); hdr = ipv6_hdr(skb);