From patchwork Sat Oct 31 18:10:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xie He X-Patchwork-Id: 1391540 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=IxcElbdF; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4CNnLb1pqkz9sS8 for ; Sun, 1 Nov 2020 05:11:35 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728272AbgJaSLe (ORCPT ); Sat, 31 Oct 2020 14:11:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727120AbgJaSLe (ORCPT ); Sat, 31 Oct 2020 14:11:34 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0032DC0617A6; Sat, 31 Oct 2020 11:11:33 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id z3so1343555pfz.6; Sat, 31 Oct 2020 11:11:33 -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=2ZRH0OzxUypIK1b/aMoXuBb/y6XgbaeCstQDTI1G9UY=; b=IxcElbdFkcgYTe6k5qR9zKCQIVmdby5pRjYwJHfUt8FX6IqcRrItr8NLtmziwXY/az mIcslyNeCzKTAeqbf9m9U8Cdp9CUAOgbkxtZp2KUL7GMRXjpjVsFg42FPxqcGlPzlsCb o+Lj+jQB96evj9xQ+MmuK2MncvEAOvNGQc1vqP5dIlCfhXqJlR2364QR194JkGUpj0GV MMiWJdG1DYTatcJ+3LmIGcekERg/0sTrB8mnO2t7e1u2d3rbzbg7REfhJSZbbJWuTymJ 1Ea1kbNOdudZWAJl7FsTXT6p2oEsXUvUj9+NPQg6T1JO/zv8/RRlNkAT1KECaHxRFwIv Yp1w== 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=2ZRH0OzxUypIK1b/aMoXuBb/y6XgbaeCstQDTI1G9UY=; b=Rn4ECjh3QCEv0xj3aGA15Bh+GPxINthikEWJifOmyqKakBsaaKHvLFdV+CHd2kkexR 8IyjWOaytoRSPQ1YWc36qIVpm3ELccPuon39BFNVWNm0gBYHSR9YonhLcFFQOnRQtmBQ iA4B3cVjjdOqq1IqicummqfrvNn5fbmgdPcVR0RPNwetKv2wsR08cPSOsmxveURzLxH6 J+BfxJRjUCv/NfkV/elA+cRAwCfwi2DeiARAXqARHFOw+lDMDvhsGFC7SKh18qJFgdic kjWB5P3ljKzYI1FRQHG7c/ECuP8JmmoXsKAN61asw9Oqt++pFkxRmxis6QysSTolQKlw TcNQ== X-Gm-Message-State: AOAM533sLdegeCbyvI/w7ccweUMdyJTj5fanqYfYrJNSU8NBFSooG6Sb yejWIMUa13kgB91+EL/SLZwbBDF3jOs= X-Google-Smtp-Source: ABdhPJwQwxMlTnslt1Tz2wnT9qcZhKp5jlmk1AqCMGi2QNa7eiDd5oj+nqLVOa67EPEDIBdJPRFUzg== X-Received: by 2002:a62:7b47:0:b029:18a:ab71:7821 with SMTP id w68-20020a627b470000b029018aab717821mr4321187pfc.3.1604167893479; Sat, 31 Oct 2020 11:11:33 -0700 (PDT) Received: from shane-XPS-13-9380.hsd1.ca.comcast.net ([2601:646:8800:1c00:32f8:16e7:6105:7fb5]) by smtp.gmail.com with ESMTPSA id n6sm6967137pjj.34.2020.10.31.11.11.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 31 Oct 2020 11:11:33 -0700 (PDT) From: Xie He To: Jakub Kicinski , "David S. Miller" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Krzysztof Halasa , Willem de Bruijn Cc: Xie He Subject: [PATCH net-next v7 2/5] net: hdlc_fr: Change the use of "dev" in fr_rx to make the code cleaner Date: Sat, 31 Oct 2020 11:10:40 -0700 Message-Id: <20201031181043.805329-3-xie.he.0141@gmail.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201031181043.805329-1-xie.he.0141@gmail.com> References: <20201031181043.805329-1-xie.he.0141@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The eth_type_trans function is called when we receive frames carrying Ethernet frames. This function expects a non-NULL pointer as an argument, and assigns it directly to skb->dev. However, the code handling other types of frames first assigns the pointer to "dev", and then at the end checks whether the value is NULL, and if it is not NULL, assigns it to skb->dev. The two flows are different. Mixing them in this function makes the code messy. It's better that we convert the second flow to align with how eth_type_trans does things. So this patch changes the code to: first make sure the pointer is not NULL, then assign it directly to skb->dev. "dev" is no longer needed until the end where we use it to update stats. Cc: Krzysztof Halasa Cc: Willem de Bruijn Signed-off-by: Xie He --- drivers/net/wan/hdlc_fr.c | 37 ++++++++++++++++++++----------------- 1 file changed, 20 insertions(+), 17 deletions(-) diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c index 4db0e01b96a9..71ee9b60d91b 100644 --- a/drivers/net/wan/hdlc_fr.c +++ b/drivers/net/wan/hdlc_fr.c @@ -880,7 +880,7 @@ static int fr_rx(struct sk_buff *skb) u8 *data = skb->data; u16 dlci; struct pvc_device *pvc; - struct net_device *dev = NULL; + struct net_device *dev; if (skb->len <= 4 || fh->ea1 || data[2] != FR_UI) goto rx_error; @@ -930,13 +930,17 @@ static int fr_rx(struct sk_buff *skb) } if (data[3] == NLPID_IP) { + if (!pvc->main) + goto rx_drop; skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */ - dev = pvc->main; + skb->dev = pvc->main; skb->protocol = htons(ETH_P_IP); } else if (data[3] == NLPID_IPV6) { + if (!pvc->main) + goto rx_drop; skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */ - dev = pvc->main; + skb->dev = pvc->main; skb->protocol = htons(ETH_P_IPV6); } else if (skb->len > 10 && data[3] == FR_PAD && @@ -950,13 +954,16 @@ static int fr_rx(struct sk_buff *skb) case ETH_P_IPX: case ETH_P_IP: /* a long variant */ case ETH_P_IPV6: - dev = pvc->main; + if (!pvc->main) + goto rx_drop; + skb->dev = pvc->main; skb->protocol = htons(pid); break; case 0x80C20007: /* bridged Ethernet frame */ - if ((dev = pvc->ether) != NULL) - skb->protocol = eth_type_trans(skb, dev); + if (!pvc->ether) + goto rx_drop; + skb->protocol = eth_type_trans(skb, pvc->ether); break; default: @@ -970,17 +977,13 @@ static int fr_rx(struct sk_buff *skb) goto rx_drop; } - if (dev) { - dev->stats.rx_packets++; /* PVC traffic */ - dev->stats.rx_bytes += skb->len; - if (pvc->state.becn) - dev->stats.rx_compressed++; - skb->dev = dev; - netif_rx(skb); - return NET_RX_SUCCESS; - } else { - goto rx_drop; - } + dev = skb->dev; + dev->stats.rx_packets++; /* PVC traffic */ + dev->stats.rx_bytes += skb->len; + if (pvc->state.becn) + dev->stats.rx_compressed++; + netif_rx(skb); + return NET_RX_SUCCESS; rx_error: frad->stats.rx_errors++; /* Mark error */