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 007362FA49 for ; Thu, 20 Jul 2023 22:03:00 +0000 (UTC) Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 607B21B6 for ; Thu, 20 Jul 2023 15:02:59 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-57704a25be9so22232707b3.1 for ; Thu, 20 Jul 2023 15:02:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1689890578; x=1690495378; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=206RntJl5N4S3vyqz152CXiY4g52GnK3+N2rFMZD3P0=; b=K1+jILZpfkoO5Im0HytBfUxM8f/T2D2oeCcTa465luZQc4AJcA82UvxtwIgErC7U5h F1OJqlPCdIxpTJhkA/6rX0c/lqmn/KA35KppVsJScvOyHkrVdQTt0S2lEbpqLPOZJ23L PzqW3uZlT/FeXlKfEGFH9vpWxwhOsKq4x9rx4x8ZYif+i1XO/R7CWgQmWqjzkWADMKiN uJzwlumLqrS0kDj1T4FIQKzRA6Z8hcsICigUrDcvvpAyE6EJT3KDH0pO8+81z5J61+NB B/fRSjL6R92cu7QklMNwqdeOea4B7H1fCf6rlWyf/z0OUTG9Z8nbEFZDfeEmhONs7cbC vr1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689890578; x=1690495378; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=206RntJl5N4S3vyqz152CXiY4g52GnK3+N2rFMZD3P0=; b=BqKrKpGX6G8qHho2ScKOyKTIFJwpT7hLq5fcuJcvNvncrSbj0lMWgklzl1yZTbXHUH Nhd+SFXqByfY3Vr357izi+KHZ86mlT2yi05nmNkb85AG/BUjhevyLmwvZ4UmiNTWJxf3 EllFc1XbfiMjR6Yc+zanwRJ8H9xcSC6Q+CQQtiaXFir4tdxE5qMm6slr1ZZPoVjVFPZ0 RaU+Z/ogTnGqOSI8vIodWJ6WTn2+2+nLXc9aDzcDAvJwbhPoTnWY4DcB79RyrocYtEkp V5tYFjokFKhb6NMyHs0fXg1Mkgg3MRdB0ORFk3iozjTYdKAgaYe6XhfAomE1OX2j0hlC H/Hg== X-Gm-Message-State: ABy/qLb/EsNQJZw9bWIB9ndfTIGVuIQ/FuvW3gQB718CSeijDhHA5IiF 6w696yXqeyxTKBvaqJonjQ47K5Q= X-Google-Smtp-Source: APBJJlGm4vXVIxoGX5PWiF+DOWtPFnx7UP3a09t0TTvXwG763koFsoHomxnwaRChpn0H98yPlIe6Q9I= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:a81:b652:0:b0:56d:19ce:416c with SMTP id h18-20020a81b652000000b0056d19ce416cmr91956ywk.0.1689890578683; Thu, 20 Jul 2023 15:02:58 -0700 (PDT) Date: Thu, 20 Jul 2023 15:02:57 -0700 In-Reply-To: <20230719183734.21681-19-larysa.zaremba@intel.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20230719183734.21681-1-larysa.zaremba@intel.com> <20230719183734.21681-19-larysa.zaremba@intel.com> Message-ID: Subject: Re: [PATCH bpf-next v3 18/21] net: make vlan_get_tag() return -ENODATA instead of -EINVAL From: Stanislav Fomichev To: Larysa Zaremba Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, haoluo@google.com, jolsa@kernel.org, David Ahern , Jakub Kicinski , Willem de Bruijn , Jesper Dangaard Brouer , Anatoly Burakov , Alexander Lobakin , Magnus Karlsson , Maryam Tahhan , xdp-hints@xdp-project.net, netdev@vger.kernel.org, Jesper Dangaard Brouer Content-Type: text/plain; charset="utf-8" X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE, USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On 07/19, Larysa Zaremba wrote: > __vlan_hwaccel_get_tag() is used in veth XDP hints implementation, > its return value (-EINVAL if skb is not VLAN tagged) is passed to bpf code, > but XDP hints specification requires drivers to return -ENODATA, if a hint > cannot be provided for a particular packet. > > Solve this inconsistency by changing error return value of > __vlan_hwaccel_get_tag() from -EINVAL to -ENODATA, do the same thing to > __vlan_get_tag(), because this function is supposed to follow the same > convention. This, in turn, makes -ENODATA the only non-zero value > vlan_get_tag() can return. We can do this with no side effects, because > none of the users of the 3 above-mentioned functions rely on the exact > value. > > Suggested-by: Jesper Dangaard Brouer > Signed-off-by: Larysa Zaremba Acked-by: Stanislav Fomichev > --- > include/linux/if_vlan.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h > index 6ba71957851e..fb35d7dd77a2 100644 > --- a/include/linux/if_vlan.h > +++ b/include/linux/if_vlan.h > @@ -540,7 +540,7 @@ static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) > struct vlan_ethhdr *veth = skb_vlan_eth_hdr(skb); > > if (!eth_type_vlan(veth->h_vlan_proto)) > - return -EINVAL; > + return -ENODATA; > > *vlan_tci = ntohs(veth->h_vlan_TCI); > return 0; > @@ -561,7 +561,7 @@ static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb, > return 0; > } else { > *vlan_tci = 0; > - return -EINVAL; > + return -ENODATA; > } > } > > -- > 2.41.0 >