From patchwork Sun May 8 19:40:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Christophe Dubois X-Patchwork-Id: 619692 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3r2wsk32MFz9s9N for ; Mon, 9 May 2016 05:43:06 +1000 (AEST) Received: from localhost ([::1]:37866 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azUbY-0000s1-DL for incoming@patchwork.ozlabs.org; Sun, 08 May 2016 15:43:04 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48973) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azUZg-0005Ym-UT for qemu-devel@nongnu.org; Sun, 08 May 2016 15:41:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1azUZb-00068U-4Z for qemu-devel@nongnu.org; Sun, 08 May 2016 15:41:07 -0400 Received: from zose-mta05.web4all.fr ([185.49.20.50]:54087) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1azUZa-00068J-6w for qemu-devel@nongnu.org; Sun, 08 May 2016 15:41:03 -0400 Received: from localhost (localhost [127.0.0.1]) by zose-mta05.web4all.fr (Postfix) with ESMTP id 21B79401AC; Sun, 8 May 2016 21:41:01 +0200 (CEST) Received: from zose-mta05.web4all.fr ([127.0.0.1]) by localhost (zose-mta05.web4all.fr [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id ECHNNKwfps3o; Sun, 8 May 2016 21:41:00 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by zose-mta05.web4all.fr (Postfix) with ESMTP id 8FAAE4054F; Sun, 8 May 2016 21:41:00 +0200 (CEST) X-Virus-Scanned: amavisd-new at zose-mta-05.w4a.fr Received: from zose-mta05.web4all.fr ([127.0.0.1]) by localhost (zose-mta05.web4all.fr [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id KRdcZZU6wG5X; Sun, 8 May 2016 21:41:00 +0200 (CEST) Received: from localhost.localdomain (smm49-1-78-235-240-156.fbx.proxad.net [78.235.240.156]) by zose-mta05.web4all.fr (Postfix) with ESMTPSA id 350B1401AC; Sun, 8 May 2016 21:41:00 +0200 (CEST) From: Jean-Christophe Dubois To: qemu-devel@nongnu.org, peter.maydell@linaro.org, jasowang@redhat.com Date: Sun, 8 May 2016 21:40:58 +0200 Message-Id: X-Mailer: git-send-email 2.7.4 In-Reply-To: References: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 185.49.20.50 Subject: [Qemu-devel] [PATCH v3 1/5] net: improve UDP/TCP checksum computation. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jean-Christophe Dubois Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" * based on Eth, UDP, TCP struct present in eth.h instead of hardcoded indexes and sizes. * based on various macros present in eth.h. Signed-off-by: Jean-Christophe Dubois --- Changes since v1: * None Changes since v2: * The patch was split in 2 parts: - a rewrite of the TCP/UDB checksum function (this patch) - the addition of the support of the VLAN header (next patch). net/checksum.c | 94 +++++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 67 insertions(+), 27 deletions(-) diff --git a/net/checksum.c b/net/checksum.c index d0fa424..f62b18a 100644 --- a/net/checksum.c +++ b/net/checksum.c @@ -18,9 +18,7 @@ #include "qemu/osdep.h" #include "qemu-common.h" #include "net/checksum.h" - -#define PROTO_TCP 6 -#define PROTO_UDP 17 +#include "net/eth.h" uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq) { @@ -57,40 +55,82 @@ uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto, void net_checksum_calculate(uint8_t *data, int length) { - int hlen, plen, proto, csum_offset; - uint16_t csum; + int ip_len; + struct ip_header *ip; + + /* + * Note: We cannot assume "data" is aligned, so the all code uses + * some macros that take care of possible unaligned access for + * struct members (just in case). + */ /* Ensure data has complete L2 & L3 headers. */ - if (length < 14 + 20) { + if (length < (sizeof(struct eth_header) + sizeof(struct ip_header))) { return; } - if ((data[14] & 0xf0) != 0x40) - return; /* not IPv4 */ - hlen = (data[14] & 0x0f) * 4; - plen = (data[16] << 8 | data[17]) - hlen; - proto = data[23]; - - switch (proto) { - case PROTO_TCP: - csum_offset = 16; - break; - case PROTO_UDP: - csum_offset = 6; - break; - default: - return; + ip = (struct ip_header *)(data + sizeof(struct eth_header)); + + if (IP_HEADER_VERSION(ip) != IP_HEADER_VERSION_4) { + return; /* not IPv4 */ } - if (plen < csum_offset + 2 || 14 + hlen + plen > length) { + ip_len = lduw_be_p(&ip->ip_len); + + /* Last, check that we have enough data for the all IP frame */ + if (length < ip_len) { return; } - data[14+hlen+csum_offset] = 0; - data[14+hlen+csum_offset+1] = 0; - csum = net_checksum_tcpudp(plen, proto, data+14+12, data+14+hlen); - data[14+hlen+csum_offset] = csum >> 8; - data[14+hlen+csum_offset+1] = csum & 0xff; + ip_len -= IP_HDR_GET_LEN(ip); + + switch (ip->ip_p) { + case IP_PROTO_TCP: + { + uint16_t csum; + tcp_header *tcp = (tcp_header *)(ip + 1); + + if (ip_len < sizeof(tcp_header)) { + return; + } + + /* Set csum to 0 */ + stw_he_p(&tcp->th_sum, 0); + + csum = net_checksum_tcpudp(ip_len, ip->ip_p, + (uint8_t *)&ip->ip_src, + (uint8_t *)tcp); + + /* Store computed csum */ + stw_be_p(&tcp->th_sum, csum); + + break; + } + case IP_PROTO_UDP: + { + uint16_t csum; + udp_header *udp = (udp_header *)(ip + 1); + + if (ip_len < sizeof(udp_header)) { + return; + } + + /* Set csum to 0 */ + stw_he_p(&udp->uh_sum, 0); + + csum = net_checksum_tcpudp(ip_len, ip->ip_p, + (uint8_t *)&ip->ip_src, + (uint8_t *)udp); + + /* Store computed csum */ + stw_be_p(&udp->uh_sum, csum); + + break; + } + default: + /* Can't handle any other protocol */ + break; + } } uint32_t