From patchwork Wed Oct 28 18:43:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xie He X-Patchwork-Id: 316086 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=-12.6 required=3.0 tests=BAYES_00,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 8EE13C4363A for ; Thu, 29 Oct 2020 02:02:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3670D20791 for ; Thu, 29 Oct 2020 02:02:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fvc9YZag" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727368AbgJ1Vsz (ORCPT ); Wed, 28 Oct 2020 17:48:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727976AbgJ1VsA (ORCPT ); Wed, 28 Oct 2020 17:48:00 -0400 Received: from mail-oi1-x243.google.com (mail-oi1-x243.google.com [IPv6:2607:f8b0:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A62D4C0613CF; Wed, 28 Oct 2020 14:48:00 -0700 (PDT) Received: by mail-oi1-x243.google.com with SMTP id f7so1145551oib.4; Wed, 28 Oct 2020 14:48:00 -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=A/cW/YFtK1RV+lsW86culRjQ8dc+fqZrnk+DqtqcbRM=; b=fvc9YZagg7e0AUWWuX4JxuRgCLq0vsNScsRdPpL4l+36rDx6K3L2V0MeNdBe1QPG9l wpmam7+A7lxg70omTP5YKHdZdiAvb1nFewEYSAcgMO1YAzlyruNcTxmkxifJvRdp7+BK AHM+jhJG4KaWenvTa5/2+quzyrQaXXdqM0efkiFm1cO7Dr1BC5/22x142PQsTkyD/OLM irxipl6cEVRCtBkIQatL9xUovDsAVmSWR2jKN2PPIyltFKfnawTYpTcQi1pEL4ZOFZmE Xcfu9ACDw5ur6pNeo7Vv5LX68bMkyu/Hyj+9upUXU4L0No12GtlCx2ONx31kxRKpbVV3 BrRQ== 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=A/cW/YFtK1RV+lsW86culRjQ8dc+fqZrnk+DqtqcbRM=; b=akLm1pTYShcBAP0EXBF7Fy76+MamA29tFo30NoPUG4ChieFjO30a2GxNEugES2p9zl VNP521u1sL/jgLh0ddlR6rCiH8rf9B99Y/rZ8Tq1FcKTz8FaXT5t8fL2qL5dc5cinZdW mjHTOMBlBwKmHHaDZXjcy5biEmP0UJX9aNyPte0WDBgcfyS7hTFJFTe4iFQfavEi+y+I Q4wV/6SFWXH1X5rg71nHFH5Me4/89vNKd3i4Qo4opsROqH223hUV4W2MZtdud5S/Pj0S ZkR/iBCGmglUSaK+uXS//9rb6mSG1cfVVB+Ifp1/6Ve5rQhESF1m6QyVnHFRlYTGkPua 8ayw== X-Gm-Message-State: AOAM532oX0cgD/b2xHs+9Fh3ekfNJBfBKD/Qq1NA7pOyJWkA6K4LdN9j cA3ru2Xa63muHQCLBwB91/YH0FXl1PY= X-Google-Smtp-Source: ABdhPJxWHcqu45Kcbd0ePFmJfXLdgetqSZap1gd/5TZTPWFANxYYv8CuQhVlBPXIYelDzr6MBiF0Ug== X-Received: by 2002:a17:90a:530c:: with SMTP id x12mr243701pjh.187.1603910603853; Wed, 28 Oct 2020 11:43:23 -0700 (PDT) Received: from shane-XPS-13-9380.hsd1.ca.comcast.net ([2601:646:8800:1c00:6d80:dec8:7340:3009]) by smtp.gmail.com with ESMTPSA id y27sm309785pfr.122.2020.10.28.11.43.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Oct 2020 11:43:23 -0700 (PDT) From: Xie He To: Jakub Kicinski , "David S. Miller" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Krzysztof Halasa Cc: Xie He Subject: [PATCH net-next v3 2/4] net: hdlc_fr: Change the use of "dev" in fr_rx to make the code cleaner Date: Wed, 28 Oct 2020 11:43:08 -0700 Message-Id: <20201028184310.7017-3-xie.he.0141@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201028184310.7017-1-xie.he.0141@gmail.com> References: <20201028184310.7017-1-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 a 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 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 c774eff44534..ac65f5c435ef 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 */