+++ /dev/null
-/**
- * @file
- * Functions common to all TCP/IPv6 modules, such as the Internet checksum and the
- * byte order functions.
- *
- */
-
-/*
- * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
- * All rights reserved.
- *
- * 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. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
- *
- * This file is part of the lwIP TCP/IP stack.
- *
- * Author: Adam Dunkels <adam@sics.se>
- *
- */
-
-#include "lwip/opt.h"
-
-#include "lwip/def.h"
-#include "lwip/inet.h"
-
-/* chksum:
- *
- * Sums up all 16 bit words in a memory portion. Also includes any odd byte.
- * This function is used by the other checksum functions.
- *
- * For now, this is not optimized. Must be optimized for the particular processor
- * arcitecture on which it is to run. Preferebly coded in assembler.
- */
-
-static u32_t
-chksum(void *dataptr, u16_t len)
-{
- u16_t *sdataptr = dataptr;
- u32_t acc;
-
-
- for(acc = 0; len > 1; len -= 2) {
- acc += *sdataptr++;
- }
-
- /* add up any odd byte */
- if (len == 1) {
- acc += htons((u16_t)(*(u8_t *)dataptr) << 8);
- }
-
- return acc;
-
-}
-
-/* inet_chksum_pseudo:
- *
- * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
- */
-
-u16_t
-inet_chksum_pseudo(struct pbuf *p,
- struct ip_addr *src, struct ip_addr *dest,
- u8_t proto, u32_t proto_len)
-{
- u32_t acc;
- struct pbuf *q;
- u8_t swapped, i;
-
- acc = 0;
- swapped = 0;
- for(q = p; q != NULL; q = q->next) {
- acc += chksum(q->payload, q->len);
- while (acc >> 16) {
- acc = (acc & 0xffff) + (acc >> 16);
- }
- if (q->len % 2 != 0) {
- swapped = 1 - swapped;
- acc = ((acc & 0xff) << 8) | ((acc & 0xff00) >> 8);
- }
- }
-
- if (swapped) {
- acc = ((acc & 0xff) << 8) | ((acc & 0xff00) >> 8);
- }
-
- for(i = 0; i < 8; i++) {
- acc += ((u16_t *)src->addr)[i] & 0xffff;
- acc += ((u16_t *)dest->addr)[i] & 0xffff;
- while (acc >> 16) {
- acc = (acc & 0xffff) + (acc >> 16);
- }
- }
- acc += (u16_t)htons((u16_t)proto);
- acc += ((u16_t *)&proto_len)[0] & 0xffff;
- acc += ((u16_t *)&proto_len)[1] & 0xffff;
-
- while (acc >> 16) {
- acc = (acc & 0xffff) + (acc >> 16);
- }
- return ~(acc & 0xffff);
-}
-
-/* inet_chksum:
- *
- * Calculates the Internet checksum over a portion of memory. Used primarely for IP
- * and ICMP.
- */
-
-u16_t
-inet_chksum(void *dataptr, u16_t len)
-{
- u32_t acc, sum;
-
- acc = chksum(dataptr, len);
- sum = (acc & 0xffff) + (acc >> 16);
- sum += (sum >> 16);
- return ~(sum & 0xffff);
-}
-
-u16_t
-inet_chksum_pbuf(struct pbuf *p)
-{
- u32_t acc;
- struct pbuf *q;
- u8_t swapped;
-
- acc = 0;
- swapped = 0;
- for(q = p; q != NULL; q = q->next) {
- acc += chksum(q->payload, q->len);
- while (acc >> 16) {
- acc = (acc & 0xffff) + (acc >> 16);
- }
- if (q->len % 2 != 0) {
- swapped = 1 - swapped;
- acc = (acc & 0xff << 8) | (acc & 0xff00 >> 8);
- }
- }
-
- if (swapped) {
- acc = ((acc & 0xff) << 8) | ((acc & 0xff00) >> 8);
- }
- return ~(acc & 0xffff);
-}