From patchwork Wed Oct 28 13:18:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xie He X-Patchwork-Id: 311314 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, URIBL_BLOCKED, 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 95E3BC56202 for ; Wed, 28 Oct 2020 22:35:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43F092070E for ; Wed, 28 Oct 2020 22:35:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="A1/dBuGT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388217AbgJ1Wfo (ORCPT ); Wed, 28 Oct 2020 18:35:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387530AbgJ1Wej (ORCPT ); Wed, 28 Oct 2020 18:34:39 -0400 Received: from mail-io1-xd41.google.com (mail-io1-xd41.google.com [IPv6:2607:f8b0:4864:20::d41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30D0DC0613CF; Wed, 28 Oct 2020 15:34:39 -0700 (PDT) Received: by mail-io1-xd41.google.com with SMTP id h21so1217372iob.10; Wed, 28 Oct 2020 15:34:39 -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=9mzi0JBUWMjjpbb/aO3F5Bvz2ioWTlLDQ0MTMYGD0gk=; b=A1/dBuGTNsdbhqUwe1pmvgkSyAMym/wvYPt6+WyE1l8CC5VtgLIT4qzDJpclvl9wB7 w2KzQkFH7YNGpJR9kUbnHJUEgSTCOB8sJ7d6P9Yg2zwtPGmFYLKsRFb1Uf5hT4C0PKLR P2YeNqZLufSHfwwzc+s5esdbIVWyA85zED2VXBniTwX7KM/rdQuhRWy7yjzKwvLfxPow pdZ8diRBT109Ye7tyY8znxlEUmyAPPdpG8zmjwOFmwU/sTLnf5NyWI3Ig2icuI+ZqZpw n/7Y7ZNW/z80L2IXNp0krtsDj82SxmQleD18iRj8Ghy2STXc7JwqUC73qw3TPNP7KUph jvsg== 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=9mzi0JBUWMjjpbb/aO3F5Bvz2ioWTlLDQ0MTMYGD0gk=; b=STZMYFVqwYMXr2z8+8lg5kKicCAsshulaMpDM9kMlOPQ6WEoqRwkMZ4/qkor1SCtTS u29Msi+D7CNoSvPvfN57gUSFD9A8qDV8XNA+6LbMiNOOxQQEkmajSGdydA7oYn4HUXFB TcuJjHB2itvgWp0ZZoIX5XI8PzMueZuokEWZ6t7Gh9Q7PPnk+GXhuJfGTnGwqqhHtYXx uOwmnc4oWjx/E9+/NtevSypJMKljhn+3zMQFPKkLLQz/MXL+LWGHvghnz3kM7mvfIDVR 5lIBGFHJkEdTU6rDn4GYBLXkUCDT7LuY+3MgmJokJzWo8Z2CdTDA5at+YZy0Lhz+bRAK BT4A== X-Gm-Message-State: AOAM530Xqz5ATKIMRxG5Ac51iI7Vd+gvFDZyoLKXAQGYASVnjYWOBx3l Kfe/qLT7FkTA7m2uK9uQ8Tj4s77WGr8= X-Google-Smtp-Source: ABdhPJynfIJJQrGHTggTvKAqZJZ0Y3W3B63/F4iYZ6dbXOSsQ23wwBiQwNbG3ngRM7xzu44FjZXGPw== X-Received: by 2002:a63:6243:: with SMTP id w64mr6307831pgb.228.1603891188228; Wed, 28 Oct 2020 06:19:48 -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 r8sm7058032pgn.30.2020.10.28.06.19.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Oct 2020 06:19:47 -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 v2 2/4] net: hdlc_fr: Change the use of "dev" in fr_rx to make the code cleaner Date: Wed, 28 Oct 2020 06:18:05 -0700 Message-Id: <20201028131807.3371-3-xie.he.0141@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201028131807.3371-1-xie.he.0141@gmail.com> References: <20201028131807.3371-1-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 a 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 */