/**************************************************************************** * net/utils/net_ipchksum.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include "utils/utils.h" #ifdef CONFIG_NET /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: ipv4_upperlayer_chksum * * Description: * Perform the checksum calculation over the IPv4, protocol headers, and * data payload as necessary. * * Input Parameters: * dev - The network driver instance. The packet data is in the d_buf * of the device. * proto - The protocol being supported * * Returned Value: * The calculated checksum * ****************************************************************************/ #if !defined(CONFIG_NET_ARCH_CHKSUM) && defined(CONFIG_NET_IPv4) uint16_t ipv4_upperlayer_chksum(FAR struct net_driver_s *dev, uint8_t proto) { FAR struct ipv4_hdr_s *ipv4 = IPv4BUF; uint16_t upperlen; uint16_t iphdrlen; uint16_t sum; /* Get the IP header length (accounting for possible options). */ iphdrlen = (ipv4->vhl & IPv4_HLMASK) << 2; /* The length reported in the IPv4 header is the length of both the IPv4 * header and the payload that follows the header. We need to subtract * the size of the IPv4 header to get the size of the payload. */ upperlen = (((uint16_t)(ipv4->len[0]) << 8) + ipv4->len[1]) - iphdrlen; /* Verify some minimal assumptions */ if (upperlen > NETDEV_PKTSIZE(dev)) { return 0; } /* First sum pseudo-header. * * IP protocol and length fields. This addition cannot carry. */ sum = upperlen + proto; /* Sum IP source and destination addresses. */ sum = chksum(sum, (FAR uint8_t *)&ipv4->srcipaddr, 2 * sizeof(in_addr_t)); /* Sum IP payload data. */ sum = chksum(sum, IPBUF(iphdrlen), upperlen); return (sum == 0) ? 0xffff : HTONS(sum); } #endif /* CONFIG_NET_ARCH_CHKSUM */ /**************************************************************************** * Name: ipv6_upperlayer_chksum * * Description: * Perform the checksum calculation over the IPv6, protocol headers, and * data payload as necessary. * * Input Parameters: * dev - The network driver instance. The packet data is in the d_buf * of the device. * proto - The protocol being supported * iplen - The size of the IPv6 header. This may be larger than * IPv6_HDRLEN the IPv6 header if IPv6 extension headers are * present. * * Returned Value: * The calculated checksum * ****************************************************************************/ #if !defined(CONFIG_NET_ARCH_CHKSUM) && defined(CONFIG_NET_IPv6) uint16_t ipv6_upperlayer_chksum(FAR struct net_driver_s *dev, uint8_t proto, unsigned int iplen) { FAR struct ipv6_hdr_s *ipv6 = IPv6BUF; uint16_t upperlen; uint16_t sum; DEBUGASSERT(dev != NULL && iplen >= IPv6_HDRLEN); /* The length reported in the IPv6 header is the length of the payload * that follows the header. If extension heders are present, then this * size includes the size of the IPv6 extension headers. */ upperlen = ((uint16_t)ipv6->len[0] << 8) + ipv6->len[1]; /* Adjust for the presence of any extension headers */ upperlen -= (iplen - IPv6_HDRLEN); /* Verify some minimal assumptions */ if (upperlen > NETDEV_PKTSIZE(dev)) { return 0; } /* The checksum is calculated starting with a pseudo-header of IPv6 header * fields according to the IPv6 standard, which consists of the source * and destination addresses, the packet length and the next header field. */ sum = upperlen + proto; /* Sum IP source and destination addresses. */ sum = chksum(sum, (FAR uint8_t *)&ipv6->srcipaddr, 2 * sizeof(net_ipv6addr_t)); /* Sum IP payload data. */ sum = chksum(sum, IPBUF(iplen), upperlen); return (sum == 0) ? 0xffff : HTONS(sum); } #endif /* CONFIG_NET_ARCH_CHKSUM */ /**************************************************************************** * Name: ipv4_chksum * * Description: * Calculate the IPv4 header checksum of the packet header in d_buf. * * The IPv4 header checksum is the Internet checksum of the 20 bytes of * the IPv4 header. * * If CONFIG_NET_ARCH_CHKSUM is defined, then this function must be * provided by architecture-specific logic. * * Returned Value: * The IPv4 header checksum of the IPv4 header in the d_buf buffer. * ****************************************************************************/ #if defined(CONFIG_NET_IPv4) && !defined(CONFIG_NET_ARCH_CHKSUM) uint16_t ipv4_chksum(FAR struct net_driver_s *dev) { FAR struct ipv4_hdr_s *ipv4 = IPv4BUF; uint16_t iphdrlen; uint16_t sum; /* Get the IP header length (accounting for possible options). */ iphdrlen = (ipv4->vhl & IPv4_HLMASK) << 2; sum = chksum(0, IPBUF(0), iphdrlen); return (sum == 0) ? 0xffff : HTONS(sum); } #endif /* CONFIG_NET_ARCH_CHKSUM */ #endif /* CONFIG_NET */