Ivan Shindev / lwip

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Dependents:   EthernetInterface

Fork of lwip by mbed official

core/ipv6/inet6.c@0:51ac1d130fd4, 2012-06-22 (annotated)

Committer:
mbed_official
Date:
Fri Jun 22 09:25:39 2012 +0000
Revision:
0:51ac1d130fd4
Initial import from lwip-1.4.0: http://download.savannah.gnu.org/releases/lwip/lwip-1.4.0.zip

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 0:51ac1d130fd4 1 /**
mbed_official 0:51ac1d130fd4 2 * @file
mbed_official 0:51ac1d130fd4 3 * Functions common to all TCP/IPv6 modules, such as the Internet checksum and the
mbed_official 0:51ac1d130fd4 4 * byte order functions.
mbed_official 0:51ac1d130fd4 5 *
mbed_official 0:51ac1d130fd4 6 */
mbed_official 0:51ac1d130fd4 7
mbed_official 0:51ac1d130fd4 8 /*
mbed_official 0:51ac1d130fd4 9 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
mbed_official 0:51ac1d130fd4 10 * All rights reserved.
mbed_official 0:51ac1d130fd4 11 *
mbed_official 0:51ac1d130fd4 12 * Redistribution and use in source and binary forms, with or without modification,
mbed_official 0:51ac1d130fd4 13 * are permitted provided that the following conditions are met:
mbed_official 0:51ac1d130fd4 14 *
mbed_official 0:51ac1d130fd4 15 * 1. Redistributions of source code must retain the above copyright notice,
mbed_official 0:51ac1d130fd4 16 * this list of conditions and the following disclaimer.
mbed_official 0:51ac1d130fd4 17 * 2. Redistributions in binary form must reproduce the above copyright notice,
mbed_official 0:51ac1d130fd4 18 * this list of conditions and the following disclaimer in the documentation
mbed_official 0:51ac1d130fd4 19 * and/or other materials provided with the distribution.
mbed_official 0:51ac1d130fd4 20 * 3. The name of the author may not be used to endorse or promote products
mbed_official 0:51ac1d130fd4 21 * derived from this software without specific prior written permission.
mbed_official 0:51ac1d130fd4 22 *
mbed_official 0:51ac1d130fd4 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
mbed_official 0:51ac1d130fd4 24 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
mbed_official 0:51ac1d130fd4 25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
mbed_official 0:51ac1d130fd4 26 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
mbed_official 0:51ac1d130fd4 27 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
mbed_official 0:51ac1d130fd4 28 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
mbed_official 0:51ac1d130fd4 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
mbed_official 0:51ac1d130fd4 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
mbed_official 0:51ac1d130fd4 31 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
mbed_official 0:51ac1d130fd4 32 * OF SUCH DAMAGE.
mbed_official 0:51ac1d130fd4 33 *
mbed_official 0:51ac1d130fd4 34 * This file is part of the lwIP TCP/IP stack.
mbed_official 0:51ac1d130fd4 35 *
mbed_official 0:51ac1d130fd4 36 * Author: Adam Dunkels <adam@sics.se>
mbed_official 0:51ac1d130fd4 37 *
mbed_official 0:51ac1d130fd4 38 */
mbed_official 0:51ac1d130fd4 39
mbed_official 0:51ac1d130fd4 40 #include "lwip/opt.h"
mbed_official 0:51ac1d130fd4 41
mbed_official 0:51ac1d130fd4 42 #include "lwip/def.h"
mbed_official 0:51ac1d130fd4 43 #include "lwip/inet.h"
mbed_official 0:51ac1d130fd4 44
mbed_official 0:51ac1d130fd4 45 /* chksum:
mbed_official 0:51ac1d130fd4 46 *
mbed_official 0:51ac1d130fd4 47 * Sums up all 16 bit words in a memory portion. Also includes any odd byte.
mbed_official 0:51ac1d130fd4 48 * This function is used by the other checksum functions.
mbed_official 0:51ac1d130fd4 49 *
mbed_official 0:51ac1d130fd4 50 * For now, this is not optimized. Must be optimized for the particular processor
mbed_official 0:51ac1d130fd4 51 * arcitecture on which it is to run. Preferebly coded in assembler.
mbed_official 0:51ac1d130fd4 52 */
mbed_official 0:51ac1d130fd4 53
mbed_official 0:51ac1d130fd4 54 static u32_t
mbed_official 0:51ac1d130fd4 55 chksum(void *dataptr, u16_t len)
mbed_official 0:51ac1d130fd4 56 {
mbed_official 0:51ac1d130fd4 57 u16_t *sdataptr = dataptr;
mbed_official 0:51ac1d130fd4 58 u32_t acc;
mbed_official 0:51ac1d130fd4 59
mbed_official 0:51ac1d130fd4 60
mbed_official 0:51ac1d130fd4 61 for(acc = 0; len > 1; len -= 2) {
mbed_official 0:51ac1d130fd4 62 acc += *sdataptr++;
mbed_official 0:51ac1d130fd4 63 }
mbed_official 0:51ac1d130fd4 64
mbed_official 0:51ac1d130fd4 65 /* add up any odd byte */
mbed_official 0:51ac1d130fd4 66 if (len == 1) {
mbed_official 0:51ac1d130fd4 67 acc += htons((u16_t)(*(u8_t *)dataptr) << 8);
mbed_official 0:51ac1d130fd4 68 }
mbed_official 0:51ac1d130fd4 69
mbed_official 0:51ac1d130fd4 70 return acc;
mbed_official 0:51ac1d130fd4 71
mbed_official 0:51ac1d130fd4 72 }
mbed_official 0:51ac1d130fd4 73
mbed_official 0:51ac1d130fd4 74 /* inet_chksum_pseudo:
mbed_official 0:51ac1d130fd4 75 *
mbed_official 0:51ac1d130fd4 76 * Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
mbed_official 0:51ac1d130fd4 77 */
mbed_official 0:51ac1d130fd4 78
mbed_official 0:51ac1d130fd4 79 u16_t
mbed_official 0:51ac1d130fd4 80 inet_chksum_pseudo(struct pbuf *p,
mbed_official 0:51ac1d130fd4 81 struct ip_addr *src, struct ip_addr *dest,
mbed_official 0:51ac1d130fd4 82 u8_t proto, u32_t proto_len)
mbed_official 0:51ac1d130fd4 83 {
mbed_official 0:51ac1d130fd4 84 u32_t acc;
mbed_official 0:51ac1d130fd4 85 struct pbuf *q;
mbed_official 0:51ac1d130fd4 86 u8_t swapped, i;
mbed_official 0:51ac1d130fd4 87
mbed_official 0:51ac1d130fd4 88 acc = 0;
mbed_official 0:51ac1d130fd4 89 swapped = 0;
mbed_official 0:51ac1d130fd4 90 for(q = p; q != NULL; q = q->next) {
mbed_official 0:51ac1d130fd4 91 acc += chksum(q->payload, q->len);
mbed_official 0:51ac1d130fd4 92 while (acc >> 16) {
mbed_official 0:51ac1d130fd4 93 acc = (acc & 0xffff) + (acc >> 16);
mbed_official 0:51ac1d130fd4 94 }
mbed_official 0:51ac1d130fd4 95 if (q->len % 2 != 0) {
mbed_official 0:51ac1d130fd4 96 swapped = 1 - swapped;
mbed_official 0:51ac1d130fd4 97 acc = ((acc & 0xff) << 8) | ((acc & 0xff00) >> 8);
mbed_official 0:51ac1d130fd4 98 }
mbed_official 0:51ac1d130fd4 99 }
mbed_official 0:51ac1d130fd4 100
mbed_official 0:51ac1d130fd4 101 if (swapped) {
mbed_official 0:51ac1d130fd4 102 acc = ((acc & 0xff) << 8) | ((acc & 0xff00) >> 8);
mbed_official 0:51ac1d130fd4 103 }
mbed_official 0:51ac1d130fd4 104
mbed_official 0:51ac1d130fd4 105 for(i = 0; i < 8; i++) {
mbed_official 0:51ac1d130fd4 106 acc += ((u16_t *)src->addr)[i] & 0xffff;
mbed_official 0:51ac1d130fd4 107 acc += ((u16_t *)dest->addr)[i] & 0xffff;
mbed_official 0:51ac1d130fd4 108 while (acc >> 16) {
mbed_official 0:51ac1d130fd4 109 acc = (acc & 0xffff) + (acc >> 16);
mbed_official 0:51ac1d130fd4 110 }
mbed_official 0:51ac1d130fd4 111 }
mbed_official 0:51ac1d130fd4 112 acc += (u16_t)htons((u16_t)proto);
mbed_official 0:51ac1d130fd4 113 acc += ((u16_t *)&proto_len)[0] & 0xffff;
mbed_official 0:51ac1d130fd4 114 acc += ((u16_t *)&proto_len)[1] & 0xffff;
mbed_official 0:51ac1d130fd4 115
mbed_official 0:51ac1d130fd4 116 while (acc >> 16) {
mbed_official 0:51ac1d130fd4 117 acc = (acc & 0xffff) + (acc >> 16);
mbed_official 0:51ac1d130fd4 118 }
mbed_official 0:51ac1d130fd4 119 return ~(acc & 0xffff);
mbed_official 0:51ac1d130fd4 120 }
mbed_official 0:51ac1d130fd4 121
mbed_official 0:51ac1d130fd4 122 /* inet_chksum:
mbed_official 0:51ac1d130fd4 123 *
mbed_official 0:51ac1d130fd4 124 * Calculates the Internet checksum over a portion of memory. Used primarely for IP
mbed_official 0:51ac1d130fd4 125 * and ICMP.
mbed_official 0:51ac1d130fd4 126 */
mbed_official 0:51ac1d130fd4 127
mbed_official 0:51ac1d130fd4 128 u16_t
mbed_official 0:51ac1d130fd4 129 inet_chksum(void *dataptr, u16_t len)
mbed_official 0:51ac1d130fd4 130 {
mbed_official 0:51ac1d130fd4 131 u32_t acc, sum;
mbed_official 0:51ac1d130fd4 132
mbed_official 0:51ac1d130fd4 133 acc = chksum(dataptr, len);
mbed_official 0:51ac1d130fd4 134 sum = (acc & 0xffff) + (acc >> 16);
mbed_official 0:51ac1d130fd4 135 sum += (sum >> 16);
mbed_official 0:51ac1d130fd4 136 return ~(sum & 0xffff);
mbed_official 0:51ac1d130fd4 137 }
mbed_official 0:51ac1d130fd4 138
mbed_official 0:51ac1d130fd4 139 u16_t
mbed_official 0:51ac1d130fd4 140 inet_chksum_pbuf(struct pbuf *p)
mbed_official 0:51ac1d130fd4 141 {
mbed_official 0:51ac1d130fd4 142 u32_t acc;
mbed_official 0:51ac1d130fd4 143 struct pbuf *q;
mbed_official 0:51ac1d130fd4 144 u8_t swapped;
mbed_official 0:51ac1d130fd4 145
mbed_official 0:51ac1d130fd4 146 acc = 0;
mbed_official 0:51ac1d130fd4 147 swapped = 0;
mbed_official 0:51ac1d130fd4 148 for(q = p; q != NULL; q = q->next) {
mbed_official 0:51ac1d130fd4 149 acc += chksum(q->payload, q->len);
mbed_official 0:51ac1d130fd4 150 while (acc >> 16) {
mbed_official 0:51ac1d130fd4 151 acc = (acc & 0xffff) + (acc >> 16);
mbed_official 0:51ac1d130fd4 152 }
mbed_official 0:51ac1d130fd4 153 if (q->len % 2 != 0) {
mbed_official 0:51ac1d130fd4 154 swapped = 1 - swapped;
mbed_official 0:51ac1d130fd4 155 acc = (acc & 0xff << 8) | (acc & 0xff00 >> 8);
mbed_official 0:51ac1d130fd4 156 }
mbed_official 0:51ac1d130fd4 157 }
mbed_official 0:51ac1d130fd4 158
mbed_official 0:51ac1d130fd4 159 if (swapped) {
mbed_official 0:51ac1d130fd4 160 acc = ((acc & 0xff) << 8) | ((acc & 0xff00) >> 8);
mbed_official 0:51ac1d130fd4 161 }
mbed_official 0:51ac1d130fd4 162 return ~(acc & 0xffff);
mbed_official 0:51ac1d130fd4 163 }