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=-14.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 55DBEC11F66 for ; Thu, 1 Jul 2021 01:40:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3ADCF6145F for ; Thu, 1 Jul 2021 01:40:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238337AbhGABmk (ORCPT ); Wed, 30 Jun 2021 21:42:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237174AbhGABmj (ORCPT ); Wed, 30 Jun 2021 21:42:39 -0400 Received: from mail-ot1-x32b.google.com (mail-ot1-x32b.google.com [IPv6:2607:f8b0:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E9D9C061756 for ; Wed, 30 Jun 2021 18:40:09 -0700 (PDT) Received: by mail-ot1-x32b.google.com with SMTP id c12-20020a9d684c0000b029047762db628aso890904oto.13 for ; Wed, 30 Jun 2021 18:40:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=AeII59XfNjxVmYLaimFclVYpr7upSoF/aG4oimEIPjw=; b=WzTGtA1eieFCA/uhQNnstVt4PQRMj1iTt3n8oOJ8KiPytm34+hgMrYZWcwlmq4A/b7 EIkKAUDtSwO7Rkk828uGbpUWTdZiwE3yMDGMBVyTWgJztY9Kty38bgnpQRh+taRUA9GI Pk8j+slUjpeN3gcjy2XiveNZFGQEGJVEMrGUfqUgL4ejk8xbgyVvNWWl02xMQsMJ8P3X nV6AHOmDL4wacbPwB2FI7KIjJ2on+BpW4gpI8bgSWZzIAgLVlfoFRAlgm7R2HOturfj1 ptWO2yTCS2BQgINR0dvit+FwA4A1ZAymDRtNZmicfXgQSzvZTFYjD3YPCvW6o3AFeTqG FURw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=AeII59XfNjxVmYLaimFclVYpr7upSoF/aG4oimEIPjw=; b=os8dDns5rYWepk0Dm1GMMCM5MD2mOo28WekcFJToJkcxIhlKajeVF+19mixPYDcD79 4BgIMVhlAUuyR+JFE6sYTocfalsgT+9vu/vGGbwNwWLZx8S2il4jz7dc/unmNo0Co23z 6asfiJqSi7VWMJgeSK169ZNl1m2TDyglyke/4Kv4TyH3/8+HkOLFqIJzyWFZwGXf8hbx zFrs65T+8ClI3vw4jFqfr+qxTB6F+LFvABusfQAs4YupGl9LQdve89lyZvYQdRNO5oH4 rrHosrG4pn+91DfPdyChiGjgty1m+6w0EP7PFMGTmI8fLOGVA7h7jlX95Zg1Ra/edpfo wenw== X-Gm-Message-State: AOAM533y6OckuwgfBpIWL9Djw5prV80dbnxqzlfpJLwzOkx17A+KT6Br xK1oMfdZG79Nao4dOu5fQn8= X-Google-Smtp-Source: ABdhPJwaM5GxUl1KhTwZuKQnmqTgfJ0XNgRow5vMq2/69qS5Za5TWhbFEZLGfYCV72g3PcVV+IlHlQ== X-Received: by 2002:a9d:6a2:: with SMTP id 31mr11222059otx.265.1625103608623; Wed, 30 Jun 2021 18:40:08 -0700 (PDT) Received: from Davids-MacBook-Pro.local ([8.48.134.38]) by smtp.googlemail.com with ESMTPSA id t76sm5013512oif.14.2021.06.30.18.40.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 30 Jun 2021 18:40:08 -0700 (PDT) Subject: Re: [RFC net-next 2/2] net: ipv4: Consolidate ipv4_mtu and ip_dst_mtu_maybe_forward To: Vadim Fedorenko , David Ahern , netdev@vger.kernel.org Cc: Jakub Kicinski , Hideaki YOSHIFUJI , "David S. Miller" , Pablo Neira Ayuso , Florian Westphal References: <20210701011728.22626-1-vfedorenko@novek.ru> <20210701011728.22626-3-vfedorenko@novek.ru> From: David Ahern Message-ID: <424dcef7-9d5e-ce3a-d9af-190ffca2a093@gmail.com> Date: Wed, 30 Jun 2021 19:40:06 -0600 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210701011728.22626-3-vfedorenko@novek.ru> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 6/30/21 7:17 PM, Vadim Fedorenko wrote: > Consolidate IPv4 MTU code the same way it is done in IPv6 to have code > aligned in both address families > > Signed-off-by: Vadim Fedorenko > --- > include/net/ip.h | 22 ++++++++++++++++++---- > net/ipv4/route.c | 21 +-------------------- > 2 files changed, 19 insertions(+), 24 deletions(-) > > diff --git a/include/net/ip.h b/include/net/ip.h > index d9683bef8684..ed261f2a40ac 100644 > --- a/include/net/ip.h > +++ b/include/net/ip.h > @@ -436,18 +436,32 @@ static inline bool ip_sk_ignore_df(const struct sock *sk) > static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, > bool forwarding) > { > + const struct rtable *rt = (const struct rtable *)dst; I realize this a code move from ipv4_mtu, but please use container_of here; I have been removing the typecasts as code is changed. > struct net *net = dev_net(dst->dev); > unsigned int mtu; > > if (net->ipv4.sysctl_ip_fwd_use_pmtu || > ip_mtu_locked(dst) || > - !forwarding) > - return dst_mtu(dst); > + !forwarding) { > + mtu = rt->rt_pmtu; > + if (mtu && time_before(jiffies, rt->dst.expires)) > + goto out; > + } > > /* 'forwarding = true' case should always honour route mtu */ > mtu = dst_metric_raw(dst, RTAX_MTU); > - if (!mtu) > - mtu = min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU); > + if (mtu) > + goto out; > + > + mtu = READ_ONCE(dst->dev->mtu); > + > + if (unlikely(ip_mtu_locked(dst))) { > + if (rt->rt_uses_gateway && mtu > 576) > + mtu = 576; > + } > + > +out: > + mtu = min_t(unsigned int, mtu, IP_MAX_MTU); > > return mtu - lwtunnel_headroom(dst->lwtstate, mtu); > } > diff --git a/net/ipv4/route.c b/net/ipv4/route.c > index 99c06944501a..04754d55b3c1 100644 > --- a/net/ipv4/route.c > +++ b/net/ipv4/route.c > @@ -1299,26 +1299,7 @@ static unsigned int ipv4_default_advmss(const struct dst_entry *dst) > > INDIRECT_CALLABLE_SCOPE unsigned int ipv4_mtu(const struct dst_entry *dst) > { > - const struct rtable *rt = (const struct rtable *)dst; > - unsigned int mtu = rt->rt_pmtu; > - > - if (!mtu || time_after_eq(jiffies, rt->dst.expires)) > - mtu = dst_metric_raw(dst, RTAX_MTU); > - > - if (mtu) > - goto out; > - > - mtu = READ_ONCE(dst->dev->mtu); > - > - if (unlikely(ip_mtu_locked(dst))) { > - if (rt->rt_uses_gateway && mtu > 576) > - mtu = 576; > - } > - > -out: > - mtu = min_t(unsigned int, mtu, IP_MAX_MTU); > - > - return mtu - lwtunnel_headroom(dst->lwtstate, mtu); > + return ip_dst_mtu_maybe_forward(dst, false); > } > EXPORT_INDIRECT_CALLABLE(ipv4_mtu); > >