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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 DCC33C5DF63 for ; Wed, 6 Nov 2019 22:04:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE3A82173E for ; Wed, 6 Nov 2019 22:04:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="h9fFXGfh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732647AbfKFWEM (ORCPT ); Wed, 6 Nov 2019 17:04:12 -0500 Received: from mail-wm1-f66.google.com ([209.85.128.66]:52553 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726957AbfKFWEL (ORCPT ); Wed, 6 Nov 2019 17:04:11 -0500 Received: by mail-wm1-f66.google.com with SMTP id c17so5854212wmk.2; Wed, 06 Nov 2019 14:04:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=6r8I0SCpSbo6ngTh6F9dpz6iIrvn5396OXePTnNw2U8=; b=h9fFXGfhomwsrDhIOPlDTH9/XZNGxhz0qH64mPq2HdxKiW+ySowOe8rBfq/r3/Rcb1 Ep6ozet54YeOvC9w4iZxIgXZIQVl3yNw/LSMRDaPpW/nLocNKuRCSL2+hLMWvAHPkwHJ BGih7Jj9wc2zeknUzfCLNwBI0jfMnzbomsz2MrLY53Idlye719FyMGPZchdeIxJCQQcp uHnWr/s2NTDxuif8+uqR++6vBEFK6kIq6Khbh3RhnmbMk6NnQXwvr0jf9M4msqza8cuk 5ByxgtrHj5Dovio4lWjryoIrXCQSHxT9jSTp20o3FAZQ7ti/jX9vr98SKhmke9oFYXV6 Mdmg== 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:mime-version :content-transfer-encoding; bh=6r8I0SCpSbo6ngTh6F9dpz6iIrvn5396OXePTnNw2U8=; b=hhs32uvq4AZeTiL4irV2cjtwEK9nQjDUOIFFnIBJlIdu3Ts0MXh2xBjpFkLjRjWtfd 7GK+Hixagh0rqM0Ls3IXI3KugMj9XfO+xEZYNdXKF3eo+nrBHTzQtVfnLd/HSPFwGEf9 K8U5TFTbBi+0U8J7kNqwThjjcXb5VeKw0uf6Rn9r+Fq19SG9Y6dcpdIeEWUKQ7x6TWc/ 4pHO9O1kofjioeP2Pzr+ZZhhwLNK4GAL1mjhYoQvvowuqEGGxQ7DlyM3M+WGurtYObgw HLAu5s36w7t/HJQpiWPaYh8BwU69wZJdCeq5dOuADmRP46oNdEULxJaFlv5MxtHTpB/J EEUw== X-Gm-Message-State: APjAAAWbCFvdSAHimBTPAPYji2CM2p3h/u6dZActAzpeLYTtUteMFToq 2qWYulOY2ZccBh/sFQXHW1A= X-Google-Smtp-Source: APXvYqwqZSYx00vA5vA5YuZhAaxFTgiX+RTj4W8pTe+SVTWIv7moEx0LZFAY7DH06jt1HBx1FrPN7Q== X-Received: by 2002:a05:600c:295:: with SMTP id 21mr4400198wmk.43.1573077847737; Wed, 06 Nov 2019 14:04:07 -0800 (PST) Received: from localhost.localdomain (dynamic-2a00-1028-9192-7022-5e51-4fff-feaa-03a7.ipv6.broadband.iol.cz. [2a00:1028:9192:7022:5e51:4fff:feaa:3a7]) by smtp.gmail.com with ESMTPSA id b3sm3958842wma.13.2019.11.06.14.04.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Nov 2019 14:04:07 -0800 (PST) From: Jaroslav Beran To: Oliver Hartkopp , Marc Kleine-Budde , "David S. Miller" , linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jaroslav Beran Subject: [PATCH] can: return error from can_send() in BUS-OFF state Date: Wed, 6 Nov 2019 23:03:02 +0100 Message-Id: <20191106220302.27698-1-jara.beran@gmail.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When a CAN node reaches BUS-OFF state, its netdev state is set to __LINK_STATE_NOCARRIER and qdisc ->enqueue() starts dropping frames and returning NET_XMIT_CN that is turned to 0 by net_xmit_errno(). So can_send() returns success to a sender even if his frame is lost. As this behavior is inappropriate for a node in BUS-OFF state, this patch adds a check for no-carrier condition and returns -ENETUNREACH in such case. Signed-off-by: Jaroslav Beran --- net/can/af_can.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/can/af_can.c b/net/can/af_can.c index 5518a7d9eed9..68c56241733b 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -189,6 +189,7 @@ static int can_create(struct net *net, struct socket *sock, int protocol, * Return: * 0 on success * -ENETDOWN when the selected interface is down + * -ENETUNREACH when the node is in BUS-OFF state * -ENOBUFS on full driver queue (see net_xmit_errno()) * -ENOMEM when local loopback failed at calling skb_clone() * -EPERM when trying to send on a non-CAN interface @@ -233,6 +234,11 @@ int can_send(struct sk_buff *skb, int loop) goto inval_skb; } + if (unlikely(!netif_carrier_ok(skb->dev))) { + err = -ENETUNREACH; + goto inval_skb; + } + skb->ip_summed = CHECKSUM_UNNECESSARY; skb_reset_mac_header(skb); -- 2.23.0