From patchwork Thu Jun 17 00:09:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Maciej_=C5=BBenczykowski?= X-Patchwork-Id: 12326301 X-Patchwork-Delegate: bpf@iogearbox.net 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=-15.8 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,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 E4ED7C48BE5 for ; Thu, 17 Jun 2021 00:10:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC9B5613BD for ; Thu, 17 Jun 2021 00:10:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231686AbhFQAMP (ORCPT ); Wed, 16 Jun 2021 20:12:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230481AbhFQAMP (ORCPT ); Wed, 16 Jun 2021 20:12:15 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36A79C061574; Wed, 16 Jun 2021 17:10:07 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id e7so1990202plj.7; Wed, 16 Jun 2021 17:10:07 -0700 (PDT) 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=UHZ5YMekjSRT+s0xrshOz5js1a8Rx9jxwpgPSLh3c50=; b=VcPw2lDwWr8gXttl6/n11H2bPuN7FSdlgQb0nNY2CZT4rrtr62H5uf0D3JNbyUYN9v gsmSS0OHfQ7c9KUdEXSNfEfvkTZLtkX9+bN/rLrl0g+934gYyKR1svtXcU19qoQv3YNP QhmI4XgFWin3PmmAv1BoROOMLi3vTtj8xwabXCwsmcZcaHFJSoMha5Z704wIlJR1T82H JWw/XS6qbHWYDm6c+wGKPeT2XeEwFZkaYC0dNpu559fwAXBSIdlaTkBIZlcG+cRJ2LAt YVu1rPMcbuNQmWcxTrv7+TylTGnhgw/9qhwqkFLpebAeSc/yMtR5gCin/ZUWjSVJcSus 84tw== 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=UHZ5YMekjSRT+s0xrshOz5js1a8Rx9jxwpgPSLh3c50=; b=FT4zKuljCvd7K69zFgH3d35DuTyi7xPL3SWOvCrO8oYIolGzzWj9RTEusGqVdCKedk UNbHQ+QzzRg2TzFPvTu84010XK61uuggS+iuF2ydI5umkkweUjrXyG+W4IcwRA55iKG/ r1ZpmFXgtQtH5nnoNErI9FN1PqDXrtNqePsOW4ci6V498NCRMofP0FsB5tnxDoZVwR2R gpw1QGwKvAB8XKffxmf7n4/fWrpyeh+vPgqgeBb0FciMPXd2/5YMgjthSuKXYvyN76a5 TLEr23lXExLZHV5osRrZJov5Om6mKr6Fy42o4sMCNofhmPnC5bIHaABOwc+3m+d279+R kqoQ== X-Gm-Message-State: AOAM5314HPFU9two+Vhlv8YmrgbdvAUkO3B9wsY1638DViQGgtbOVamN Cf0FpDr8cqIFu1Lm9gi9Gi0= X-Google-Smtp-Source: ABdhPJwzbbuVxuncCTkspM/BldbgMP+QMLtdFrOs8MgJF15b0MYiY/1TxZyqoEp1K+K6XFBYKVUnIA== X-Received: by 2002:a17:90a:5907:: with SMTP id k7mr2474463pji.46.1623888606695; Wed, 16 Jun 2021 17:10:06 -0700 (PDT) Received: from athina.mtv.corp.google.com ([2620:15c:211:200:926a:e8dd:9095:3ddd]) by smtp.gmail.com with ESMTPSA id r92sm6599633pja.6.2021.06.16.17.10.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Jun 2021 17:10:06 -0700 (PDT) From: =?utf-8?q?Maciej_=C5=BBenczykowski?= To: =?utf-8?q?Maciej_=C5=BBenczykowski?= , Alexei Starovoitov , Daniel Borkmann Cc: Linux Network Development Mailing List , Linux Kernel Mailing List , BPF Mailing List , "David S . Miller" , Dongseok Yi , Willem de Bruijn Subject: [PATCH bpf-next v2 1/4] Revert "bpf: Check for BPF_F_ADJ_ROOM_FIXED_GSO when bpf_skb_change_proto" Date: Wed, 16 Jun 2021 17:09:50 -0700 Message-Id: <20210617000953.2787453-1-zenczykowski@gmail.com> X-Mailer: git-send-email 2.32.0.272.g935e593368-goog In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Maciej Żenczykowski This reverts commit fa7b83bf3b156c767f3e4a25bbf3817b08f3ff8e. See the followup commit for the reasoning why I believe the appropriate approach is to simply make this change without a flag, but it can basically be summarized as using this helper without the flag is bug-prone or outright buggy, and thus the default should be this new behaviour. As this commit has only made it into net-next/master, but not into any real release, such a backwards incompatible change is still ok. Cc: Dongseok Yi Cc: Daniel Borkmann Cc: Willem de Bruijn Signed-off-by: Maciej Żenczykowski --- net/core/filter.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 239de1306de9..65ab4e21c087 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3235,7 +3235,7 @@ static int bpf_skb_net_hdr_pop(struct sk_buff *skb, u32 off, u32 len) return ret; } -static int bpf_skb_proto_4_to_6(struct sk_buff *skb, u64 flags) +static int bpf_skb_proto_4_to_6(struct sk_buff *skb) { const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr); u32 off = skb_mac_header_len(skb); @@ -3264,9 +3264,7 @@ static int bpf_skb_proto_4_to_6(struct sk_buff *skb, u64 flags) } /* Due to IPv6 header, MSS needs to be downgraded. */ - if (!(flags & BPF_F_ADJ_ROOM_FIXED_GSO)) - skb_decrease_gso_size(shinfo, len_diff); - + skb_decrease_gso_size(shinfo, len_diff); /* Header must be checked, and gso_segs recomputed. */ shinfo->gso_type |= SKB_GSO_DODGY; shinfo->gso_segs = 0; @@ -3278,7 +3276,7 @@ static int bpf_skb_proto_4_to_6(struct sk_buff *skb, u64 flags) return 0; } -static int bpf_skb_proto_6_to_4(struct sk_buff *skb, u64 flags) +static int bpf_skb_proto_6_to_4(struct sk_buff *skb) { const u32 len_diff = sizeof(struct ipv6hdr) - sizeof(struct iphdr); u32 off = skb_mac_header_len(skb); @@ -3307,9 +3305,7 @@ static int bpf_skb_proto_6_to_4(struct sk_buff *skb, u64 flags) } /* Due to IPv4 header, MSS can be upgraded. */ - if (!(flags & BPF_F_ADJ_ROOM_FIXED_GSO)) - skb_increase_gso_size(shinfo, len_diff); - + skb_increase_gso_size(shinfo, len_diff); /* Header must be checked, and gso_segs recomputed. */ shinfo->gso_type |= SKB_GSO_DODGY; shinfo->gso_segs = 0; @@ -3321,17 +3317,17 @@ static int bpf_skb_proto_6_to_4(struct sk_buff *skb, u64 flags) return 0; } -static int bpf_skb_proto_xlat(struct sk_buff *skb, __be16 to_proto, u64 flags) +static int bpf_skb_proto_xlat(struct sk_buff *skb, __be16 to_proto) { __be16 from_proto = skb->protocol; if (from_proto == htons(ETH_P_IP) && to_proto == htons(ETH_P_IPV6)) - return bpf_skb_proto_4_to_6(skb, flags); + return bpf_skb_proto_4_to_6(skb); if (from_proto == htons(ETH_P_IPV6) && to_proto == htons(ETH_P_IP)) - return bpf_skb_proto_6_to_4(skb, flags); + return bpf_skb_proto_6_to_4(skb); return -ENOTSUPP; } @@ -3341,7 +3337,7 @@ BPF_CALL_3(bpf_skb_change_proto, struct sk_buff *, skb, __be16, proto, { int ret; - if (unlikely(flags & ~(BPF_F_ADJ_ROOM_FIXED_GSO))) + if (unlikely(flags)) return -EINVAL; /* General idea is that this helper does the basic groundwork @@ -3361,7 +3357,7 @@ BPF_CALL_3(bpf_skb_change_proto, struct sk_buff *, skb, __be16, proto, * that. For offloads, we mark packet as dodgy, so that headers * need to be verified first. */ - ret = bpf_skb_proto_xlat(skb, proto, flags); + ret = bpf_skb_proto_xlat(skb, proto); bpf_compute_data_pointers(skb); return ret; }