/**************************************************************************** * net/uip/uip_chksum.c * * Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #ifdef CONFIG_NET #include #include #include #include #include #include "uip_internal.h" /**************************************************************************** * Definitions ****************************************************************************/ #define BUF ((struct uip_ip_hdr *)&dev->d_buf[UIP_LLH_LEN]) #define ICMPBUF ((struct uip_icmpip_hdr *)&dev->d_buf[UIP_LLH_LEN]) /**************************************************************************** * Private Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ #if !UIP_ARCH_CHKSUM static uint16 chksum(uint16 sum, const uint8 *data, uint16 len) { uint16 t; const uint8 *dataptr; const uint8 *last_byte; dataptr = data; last_byte = data + len - 1; while(dataptr < last_byte) { /* At least two more bytes */ t = (dataptr[0] << 8) + dataptr[1]; sum += t; if (sum < t) { sum++; /* carry */ } dataptr += 2; } if (dataptr == last_byte) { t = (dataptr[0] << 8) + 0; sum += t; if (sum < t) { sum++; /* carry */ } } /* Return sum in host byte order. */ return sum; } static uint16 upper_layer_chksum(struct uip_driver_s *dev, uint8 proto) { uint16 upper_layer_len; uint16 sum; #ifdef CONFIG_NET_IPv6 upper_layer_len = (((uint16)(BUF->len[0]) << 8) + BUF->len[1]); #else /* CONFIG_NET_IPv6 */ upper_layer_len = (((uint16)(BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN; #endif /* CONFIG_NET_IPv6 */ /* First sum pseudoheader. */ /* IP protocol and length fields. This addition cannot carry. */ sum = upper_layer_len + proto; /* Sum IP source and destination addresses. */ sum = chksum(sum, (uint8 *)&BUF->srcipaddr, 2 * sizeof(uip_ipaddr_t)); /* Sum TCP header and data. */ sum = chksum(sum, &dev->d_buf[UIP_IPH_LEN + UIP_LLH_LEN], upper_layer_len); return (sum == 0) ? 0xffff : htons(sum); } #ifdef CONFIG_NET_IPv6 static uint16 uip_icmp6chksum(struct uip_driver_s *dev) { return upper_layer_chksum(dev, UIP_PROTO_ICMP6); } #endif /* CONFIG_NET_IPv6 */ #endif /* UIP_ARCH_CHKSUM */ /**************************************************************************** * Public Functions ****************************************************************************/ /* Calculate the Internet checksum over a buffer. */ #if !UIP_ARCH_ADD32 static void uip_carry32(uint8 *sum, uint16 op16) { if (sum[2] < (op16 >> 8)) { ++sum[1]; if (sum[1] == 0) { ++sum[0]; } } if (sum[3] < (op16 & 0xff)) { ++sum[2]; if (sum[2] == 0) { ++sum[1]; if (sum[1] == 0) { ++sum[0]; } } } } void uip_add32(const uint8 *op32, uint16 op16, uint8 *sum) { /* op32 and the sum are in network order (big-endian); op16 is host order. */ sum[3] = op32[3] + (op16 & 0xff); sum[2] = op32[2] + (op16 >> 8); sum[1] = op32[1]; sum[0] = op32[0]; uip_carry32(sum, op16); } void uip_incr32(uint8 *op32, uint16 op16) { op32[3] += (op16 & 0xff); op32[2] += (op16 >> 8); uip_carry32(op32, op16); } #endif /* UIP_ARCH_ADD32 */ #if !UIP_ARCH_CHKSUM uint16 uip_chksum(uint16 *data, uint16 len) { return htons(chksum(0, (uint8 *)data, len)); } /* Calculate the IP header checksum of the packet header in d_buf. */ #ifndef UIP_ARCH_IPCHKSUM uint16 uip_ipchksum(struct uip_driver_s *dev) { uint16 sum; sum = chksum(0, &dev->d_buf[UIP_LLH_LEN], UIP_IPH_LEN); return (sum == 0) ? 0xffff : htons(sum); } #endif /* Calculate the TCP checksum of the packet in d_buf and d_appdata. */ uint16 uip_tcpchksum(struct uip_driver_s *dev) { return upper_layer_chksum(dev, UIP_PROTO_TCP); } /* Calculate the UDP checksum of the packet in d_buf and d_appdata. */ #ifdef CONFIG_NET_UDP_CHECKSUMS uint16 uip_udpchksum(struct uip_driver_s *dev) { return upper_layer_chksum(dev, UIP_PROTO_UDP); } #endif /* Calculate the checksum of the ICMP message */ #if defined(CONFIG_NET_ICMP) && defined(CONFIG_NET_ICMP_PING) uint16 uip_icmpchksum(struct uip_driver_s *dev) { return uip_chksum((uint16*)&ICMPBUF->type, dev->d_sndlen); } #endif #endif /* UIP_ARCH_CHKSUM */ #endif /* CONFIG_NET */