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=-7.8 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,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 8DBEAC433E6 for ; Fri, 29 Jan 2021 06:55:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47BF864DD9 for ; Fri, 29 Jan 2021 06:55:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232021AbhA2GzQ (ORCPT ); Fri, 29 Jan 2021 01:55:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232079AbhA2GzJ (ORCPT ); Fri, 29 Jan 2021 01:55:09 -0500 Received: from mail-io1-xd2b.google.com (mail-io1-xd2b.google.com [IPv6:2607:f8b0:4864:20::d2b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38490C061574; Thu, 28 Jan 2021 22:54:29 -0800 (PST) Received: by mail-io1-xd2b.google.com with SMTP id z22so8233734ioh.9; Thu, 28 Jan 2021 22:54:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:content-transfer-encoding; bh=w1qFvHGQrgqVJ85D0sHlcLhT5Dm3LE2q2Y+BTD7Vsv4=; b=BQGARVbE3npzSq7MtlSHqM9zDHDZQcF48nYtTfdcGte4dIa3tpUr/wpvmz0RzKD8Hy s0JzAeRY1tDVJzuyilq2Sf68hPvIYhtHcQKibinBJz0N8+e/SxiZ/B6F2ZVUYhzsAOHJ IT+wFJR8xtbuSSnGTsKLZBffpVN76aNLc8olCNHgzOWIZb9XiHT4SnueiVT4AZWhy5Ve adsWj6Rm8Nhav4ZPttqhvBO8dUG6i5G+p9c0hr96tAemwylkq/QqRYROPoc7ZjI+fGDx +o0IHIyEqNZ2rXjTGuLsHtU2gnZsDWgTxQ2SdpmnXXG8PDpfJP953e4N2xSHFwzSJSaw BzGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-transfer-encoding; bh=w1qFvHGQrgqVJ85D0sHlcLhT5Dm3LE2q2Y+BTD7Vsv4=; b=VyAOf/WVwHY0roQShKJb91EyGiVEfiLykxWE8pF+e9i30LEiH5W7QWcDH7vsilh45H Y1lGtgoGo0pQj/3qZKRHL6XbiJGJOdHFVYNEaUMQro0Kcl1Fp63EvCK4XdHrnZJKXRSD 2j8eRzQisYuLHZAJC3cUmy7Nzktgf7mJ2YXnsk2coXkUYBwCpWEqDzOO9ko+/SGfWrEi joGZP2Gb/dmhvvmyPifUJ+88G9sfxH+fBd4d0r5SrnOw48bsNryYIzNc4K96Kxyi/SCm yR2EeMmW+jgWnxlrZ5oP6kOMNRfEQfow0wvbxh+Saz1i8rkgSSTSnTnhZ+ng8xecWuus 7X+w== X-Gm-Message-State: AOAM530gUYdmozWkvx4d82PSVTYBNKdYuGYRFvR3gPE+GkA3JPO76tgu 2LYjuoRPCRxKZjsbzXb/Wbg= X-Google-Smtp-Source: ABdhPJwurA+QY6mnuFYRtTw6wlAfQDi/XHlyeQiJeSeKdDb/YsinkXj/2S+jTIjk4TL2bk6shmBjKg== X-Received: by 2002:a5d:89c3:: with SMTP id a3mr2858844iot.85.1611903268800; Thu, 28 Jan 2021 22:54:28 -0800 (PST) Received: from localhost ([172.243.146.206]) by smtp.gmail.com with ESMTPSA id z16sm4003281ilp.67.2021.01.28.22.54.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 28 Jan 2021 22:54:28 -0800 (PST) Date: Thu, 28 Jan 2021 22:54:21 -0800 From: John Fastabend To: Jesper Dangaard Brouer , bpf@vger.kernel.org Cc: Jesper Dangaard Brouer , netdev@vger.kernel.org, Daniel Borkmann , Alexei Starovoitov , maze@google.com, lmb@cloudflare.com, shaun@tigera.io, Lorenzo Bianconi , marek@cloudflare.com, John Fastabend , Jakub Kicinski , eyal.birger@gmail.com, colrack@gmail.com Message-ID: <6013b11d98ad2_2683c20876@john-XPS-13-9370.notmuch> In-Reply-To: <161159457746.321749.16725918278187413283.stgit@firesoul> References: <161159451743.321749.17528005626909164523.stgit@firesoul> <161159457746.321749.16725918278187413283.stgit@firesoul> Subject: RE: [PATCH bpf-next V13 5/7] bpf: drop MTU check when doing TC-BPF redirect to ingress Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Jesper Dangaard Brouer wrote: > The use-case for dropping the MTU check when TC-BPF does redirect to > ingress, is described by Eyal Birger in email[0]. The summary is the > ability to increase packet size (e.g. with IPv6 headers for NAT64) and > ingress redirect packet and let normal netstack fragment packet as needed. > > [0] https://lore.kernel.org/netdev/CAHsH6Gug-hsLGHQ6N0wtixdOa85LDZ3HNRHVd0opR=19Qo4W4Q@mail.gmail.com/ > > V9: > - Make net_device "up" (IFF_UP) check explicit in skb_do_redirect > > V4: > - Keep net_device "up" (IFF_UP) check. > - Adjustment to handle bpf_redirect_peer() helper > > Signed-off-by: Jesper Dangaard Brouer > --- LGTM. Acked-by: John Fastabend