From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id EC0F6A00C3; Thu, 14 May 2020 03:27:48 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id E32401D66B; Thu, 14 May 2020 03:27:47 +0200 (CEST) Received: from huawei.com (szxga05-in.huawei.com [45.249.212.191]) by dpdk.org (Postfix) with ESMTP id D99C21D667 for ; Thu, 14 May 2020 03:27:46 +0200 (CEST) Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 221EA57AF23BABBB91C0; Thu, 14 May 2020 09:27:44 +0800 (CST) Received: from DESKTOP-ORJPOMD.china.huawei.com (10.173.251.143) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.487.0; Thu, 14 May 2020 09:27:35 +0800 From: guohongzhi To: CC: , , , , , , , , , , Date: Thu, 14 May 2020 09:27:29 +0800 Message-ID: <20200514012729.23920-1-guohongzhi1@huawei.com> X-Mailer: git-send-email 2.21.0.windows.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.173.251.143] X-CFilter-Loop: Reflected Subject: [dpdk-dev] [PATCH] lib/librte_net: fix bug for ipv4 checksum calculating X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" The function of rte_ipv4_cksum for calculating the checksum of IPv4 header is incorrect. This function will return checksum value like 0xffff. This value, however, is considered an illegal checksum on some switches(like Trident3). RFC 1624 specifies the IPv4 checksum as follows: https://tools.ietf.org/rfc/rfc1624 Since there is guaranteed to be at least one non-zero field in the IP header, and the checksum field in the protocol header is the complement of the sum, the checksum field can never contain ~(+0), which is -0 (0xFFFF). It can, however, contain ~(-0), which is +0 (0x0000). --- lib/librte_net/rte_ip.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h index 1ceb7b7..ece2e43 100644 --- a/lib/librte_net/rte_ip.h +++ b/lib/librte_net/rte_ip.h @@ -267,7 +267,7 @@ rte_ipv4_cksum(const struct rte_ipv4_hdr *ipv4_hdr) { uint16_t cksum; cksum = rte_raw_cksum(ipv4_hdr, sizeof(struct rte_ipv4_hdr)); - return (cksum == 0xffff) ? cksum : (uint16_t)~cksum; + return (uint16_t)~cksum; } /** -- 2.21.0.windows.1