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=-11.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 0586AC47087 for ; Fri, 28 May 2021 23:11:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D955F613B4 for ; Fri, 28 May 2021 23:11:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229666AbhE1XNM (ORCPT ); Fri, 28 May 2021 19:13:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:59104 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229631AbhE1XNH (ORCPT ); Fri, 28 May 2021 19:13:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5FC68613EB; Fri, 28 May 2021 23:11:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622243492; bh=6R6S4sFCJq92IstxTP9ek22qzcdli0PcwyHoyNTTrkU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=qsBPeIy9Mj1YUWEX30WNcd5Nlp6nThlJQ/ma7GuKMXqlx0Oh5VQG0myAIWoLfRH3N 8LB4P6BLQuYVb8HOuQEBdzxGIKL/BPHxtdvNZdkCheE8hX4IZaHailXDw8q2qpTs4t 8cDArsgG+D1BAK6toogvZXTjucPP7+/KUtnAZBVhmV0VhIATiOEIuMxR3YVz/LhcEu YWsMbmQxzlMheFjnxGYodZKPOhtUz37G+pIT+MmZ94snbMJDziSZQWHR+MUzchqi5a /zG5Qjrg59El7yZGywKCf7UaixonmaJQl0ed8cuAMeqhw8Bh8l4WR4kFx5V4EvUFtB 45VNy8LsMP0XQ== Date: Fri, 28 May 2021 16:11:31 -0700 From: Jakub Kicinski To: Sharath Chandra Vurukala Cc: davem@davemloft.net, elder@kernel.org, cpratapa@codeaurora.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next v7 3/3] net: ethernet: rmnet: Add support for MAPv5 egress packets Message-ID: <20210528161131.5f7b9920@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> In-Reply-To: <1622105322-2975-4-git-send-email-sharathv@codeaurora.org> References: <1622105322-2975-1-git-send-email-sharathv@codeaurora.org> <1622105322-2975-4-git-send-email-sharathv@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 27 May 2021 14:18:42 +0530 Sharath Chandra Vurukala wrote: > Adding support for MAPv5 egress packets. > > This involves adding the MAPv5 header and setting the csum_valid_required > in the checksum header to request HW compute the checksum. > > Corresponding stats are incremented based on whether the checksum is > computed in software or HW. > > New stat has been added which represents the count of packets whose > checksum is calculated by the HW. > > Signed-off-by: Sharath Chandra Vurukala > +static void rmnet_map_v5_checksum_uplink_packet(struct sk_buff *skb, > + struct rmnet_port *port, > + struct net_device *orig_dev) > +{ > + struct rmnet_priv *priv = netdev_priv(orig_dev); > + struct rmnet_map_v5_csum_header *ul_header; > + > + if (!(port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV5)) > + return; how can we get here if this condition is not met? Looks like defensive programming. > + ul_header = skb_push(skb, sizeof(*ul_header)); Are you making sure you can modify head? I only see a check if there is enough headroom but not if head is writable (skb_cow_head()). > + memset(ul_header, 0, sizeof(*ul_header)); > + ul_header->header_info = u8_encode_bits(RMNET_MAP_HEADER_TYPE_CSUM_OFFLOAD, > + MAPV5_HDRINFO_HDR_TYPE_FMASK); Is prepending the header required even when packet doesn't need checksuming? > + if (skb->ip_summed == CHECKSUM_PARTIAL) { > + void *iph = (char *)ul_header + sizeof(*ul_header); ip_hdr(skb) > + __sum16 *check; > + void *trans; > + u8 proto; > + > + if (skb->protocol == htons(ETH_P_IP)) { > + u16 ip_len = ((struct iphdr *)iph)->ihl * 4; > + > + proto = ((struct iphdr *)iph)->protocol; > + trans = iph + ip_len; > + } else if (skb->protocol == htons(ETH_P_IPV6)) { > +#if IS_ENABLED(CONFIG_IPV6) > + u16 ip_len = sizeof(struct ipv6hdr); > + > + proto = ((struct ipv6hdr *)iph)->nexthdr; > + trans = iph + ip_len; > +#else > + priv->stats.csum_err_invalid_ip_version++; > + goto sw_csum; > +#endif /* CONFIG_IPV6 */ > + } else { > + priv->stats.csum_err_invalid_ip_version++; > + goto sw_csum; > + } > + > + check = rmnet_map_get_csum_field(proto, trans); > + if (check) { > + skb->ip_summed = CHECKSUM_NONE; > + /* Ask for checksum offloading */ > + ul_header->csum_info |= MAPV5_CSUMINFO_VALID_FLAG; > + priv->stats.csum_hw++; > + return; Please try to keep the success path unindented. > + } > + } > + > +sw_csum: > + priv->stats.csum_sw++; > +}