1 | /**
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2 | * @file
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3 | * Internet checksum functions.\n
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4 | *
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5 | * These are some reference implementations of the checksum algorithm, with the
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6 | * aim of being simple, correct and fully portable. Checksumming is the
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7 | * first thing you would want to optimize for your platform. If you create
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8 | * your own version, link it in and in your cc.h put:
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9 | *
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10 | * \#define LWIP_CHKSUM your_checksum_routine
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11 | *
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12 | * Or you can select from the implementations below by defining
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13 | * LWIP_CHKSUM_ALGORITHM to 1, 2 or 3.
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14 | */
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15 |
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16 | /*
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17 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
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18 | * All rights reserved.
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19 | *
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20 | * Redistribution and use in source and binary forms, with or without modification,
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21 | * are permitted provided that the following conditions are met:
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22 | *
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23 | * 1. Redistributions of source code must retain the above copyright notice,
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24 | * this list of conditions and the following disclaimer.
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25 | * 2. Redistributions in binary form must reproduce the above copyright notice,
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26 | * this list of conditions and the following disclaimer in the documentation
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27 | * and/or other materials provided with the distribution.
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28 | * 3. The name of the author may not be used to endorse or promote products
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29 | * derived from this software without specific prior written permission.
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30 | *
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31 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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32 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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33 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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34 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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35 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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36 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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37 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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38 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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39 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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40 | * OF SUCH DAMAGE.
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41 | *
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42 | * This file is part of the lwIP TCP/IP stack.
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43 | *
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44 | * Author: Adam Dunkels <adam@sics.se>
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45 | *
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46 | */
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47 |
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48 | #include "lwip/opt.h"
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49 |
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50 | #include "lwip/inet_chksum.h"
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51 | #include "lwip/def.h"
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52 | #include "lwip/ip_addr.h"
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53 |
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54 | #include <string.h>
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55 |
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56 | #ifndef LWIP_CHKSUM
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57 | # define LWIP_CHKSUM lwip_standard_chksum
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58 | # ifndef LWIP_CHKSUM_ALGORITHM
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59 | # define LWIP_CHKSUM_ALGORITHM 2
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60 | # endif
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61 | u16_t lwip_standard_chksum(const void *dataptr, int len);
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62 | #endif
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63 | /* If none set: */
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64 | #ifndef LWIP_CHKSUM_ALGORITHM
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65 | # define LWIP_CHKSUM_ALGORITHM 0
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66 | #endif
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67 |
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68 | #if (LWIP_CHKSUM_ALGORITHM == 1) /* Version #1 */
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69 | /**
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70 | * lwip checksum
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71 | *
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72 | * @param dataptr points to start of data to be summed at any boundary
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73 | * @param len length of data to be summed
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74 | * @return host order (!) lwip checksum (non-inverted Internet sum)
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75 | *
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76 | * @note accumulator size limits summable length to 64k
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77 | * @note host endianess is irrelevant (p3 RFC1071)
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78 | */
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79 | u16_t
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80 | lwip_standard_chksum(const void *dataptr, int len)
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81 | {
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82 | u32_t acc;
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83 | u16_t src;
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84 | const u8_t *octetptr;
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85 |
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86 | acc = 0;
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87 | /* dataptr may be at odd or even addresses */
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88 | octetptr = (const u8_t *)dataptr;
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89 | while (len > 1) {
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90 | /* declare first octet as most significant
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91 | thus assume network order, ignoring host order */
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92 | src = (*octetptr) << 8;
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93 | octetptr++;
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94 | /* declare second octet as least significant */
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95 | src |= (*octetptr);
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96 | octetptr++;
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97 | acc += src;
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98 | len -= 2;
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99 | }
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100 | if (len > 0) {
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101 | /* accumulate remaining octet */
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102 | src = (*octetptr) << 8;
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103 | acc += src;
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104 | }
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105 | /* add deferred carry bits */
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106 | acc = (acc >> 16) + (acc & 0x0000ffffUL);
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107 | if ((acc & 0xffff0000UL) != 0) {
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108 | acc = (acc >> 16) + (acc & 0x0000ffffUL);
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109 | }
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110 | /* This maybe a little confusing: reorder sum using lwip_htons()
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111 | instead of lwip_ntohs() since it has a little less call overhead.
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112 | The caller must invert bits for Internet sum ! */
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113 | return lwip_htons((u16_t)acc);
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114 | }
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115 | #endif
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116 |
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117 | #if (LWIP_CHKSUM_ALGORITHM == 2) /* Alternative version #2 */
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118 | /*
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119 | * Curt McDowell
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120 | * Broadcom Corp.
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121 | * csm@broadcom.com
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122 | *
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123 | * IP checksum two bytes at a time with support for
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124 | * unaligned buffer.
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125 | * Works for len up to and including 0x20000.
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126 | * by Curt McDowell, Broadcom Corp. 12/08/2005
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127 | *
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128 | * @param dataptr points to start of data to be summed at any boundary
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129 | * @param len length of data to be summed
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130 | * @return host order (!) lwip checksum (non-inverted Internet sum)
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131 | */
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132 | u16_t
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133 | lwip_standard_chksum(const void *dataptr, int len)
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134 | {
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135 | const u8_t *pb = (const u8_t *)dataptr;
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136 | const u16_t *ps;
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137 | u16_t t = 0;
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138 | u32_t sum = 0;
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139 | int odd = ((mem_ptr_t)pb & 1);
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140 |
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141 | /* Get aligned to u16_t */
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142 | if (odd && len > 0) {
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143 | ((u8_t *)&t)[1] = *pb++;
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144 | len--;
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145 | }
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146 |
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147 | /* Add the bulk of the data */
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148 | ps = (const u16_t *)(const void *)pb;
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149 | while (len > 1) {
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150 | sum += *ps++;
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151 | len -= 2;
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152 | }
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153 |
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154 | /* Consume left-over byte, if any */
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155 | if (len > 0) {
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156 | ((u8_t *)&t)[0] = *(const u8_t *)ps;
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157 | }
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158 |
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159 | /* Add end bytes */
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160 | sum += t;
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161 |
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162 | /* Fold 32-bit sum to 16 bits
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163 | calling this twice is probably faster than if statements... */
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164 | sum = FOLD_U32T(sum);
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165 | sum = FOLD_U32T(sum);
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166 |
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167 | /* Swap if alignment was odd */
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168 | if (odd) {
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169 | sum = SWAP_BYTES_IN_WORD(sum);
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170 | }
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171 |
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172 | return (u16_t)sum;
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173 | }
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174 | #endif
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175 |
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176 | #if (LWIP_CHKSUM_ALGORITHM == 3) /* Alternative version #3 */
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177 | /**
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178 | * An optimized checksum routine. Basically, it uses loop-unrolling on
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179 | * the checksum loop, treating the head and tail bytes specially, whereas
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180 | * the inner loop acts on 8 bytes at a time.
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181 | *
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182 | * @arg start of buffer to be checksummed. May be an odd byte address.
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183 | * @len number of bytes in the buffer to be checksummed.
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184 | * @return host order (!) lwip checksum (non-inverted Internet sum)
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185 | *
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186 | * by Curt McDowell, Broadcom Corp. December 8th, 2005
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187 | */
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188 | u16_t
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189 | lwip_standard_chksum(const void *dataptr, int len)
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190 | {
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191 | const u8_t *pb = (const u8_t *)dataptr;
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192 | const u16_t *ps;
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193 | u16_t t = 0;
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194 | const u32_t *pl;
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195 | u32_t sum = 0, tmp;
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196 | /* starts at odd byte address? */
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197 | int odd = ((mem_ptr_t)pb & 1);
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198 |
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199 | if (odd && len > 0) {
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200 | ((u8_t *)&t)[1] = *pb++;
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201 | len--;
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202 | }
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203 |
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204 | ps = (const u16_t *)(const void *)pb;
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205 |
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206 | if (((mem_ptr_t)ps & 3) && len > 1) {
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207 | sum += *ps++;
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208 | len -= 2;
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209 | }
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210 |
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211 | pl = (const u32_t *)(const void *)ps;
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212 |
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213 | while (len > 7) {
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214 | tmp = sum + *pl++; /* ping */
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215 | if (tmp < sum) {
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216 | tmp++; /* add back carry */
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217 | }
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218 |
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219 | sum = tmp + *pl++; /* pong */
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220 | if (sum < tmp) {
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221 | sum++; /* add back carry */
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222 | }
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223 |
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224 | len -= 8;
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225 | }
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226 |
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227 | /* make room in upper bits */
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228 | sum = FOLD_U32T(sum);
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229 |
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230 | ps = (const u16_t *)pl;
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231 |
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232 | /* 16-bit aligned word remaining? */
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233 | while (len > 1) {
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234 | sum += *ps++;
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235 | len -= 2;
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236 | }
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237 |
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238 | /* dangling tail byte remaining? */
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239 | if (len > 0) { /* include odd byte */
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240 | ((u8_t *)&t)[0] = *(const u8_t *)ps;
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241 | }
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242 |
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243 | sum += t; /* add end bytes */
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244 |
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245 | /* Fold 32-bit sum to 16 bits
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246 | calling this twice is probably faster than if statements... */
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247 | sum = FOLD_U32T(sum);
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248 | sum = FOLD_U32T(sum);
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249 |
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250 | if (odd) {
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251 | sum = SWAP_BYTES_IN_WORD(sum);
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252 | }
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253 |
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254 | return (u16_t)sum;
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255 | }
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256 | #endif
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257 |
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258 | /** Parts of the pseudo checksum which are common to IPv4 and IPv6 */
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259 | static u16_t
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260 | inet_cksum_pseudo_base(struct pbuf *p, u8_t proto, u16_t proto_len, u32_t acc)
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261 | {
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262 | struct pbuf *q;
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263 | int swapped = 0;
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264 |
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265 | /* iterate through all pbuf in chain */
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266 | for (q = p; q != NULL; q = q->next) {
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267 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
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268 | (void *)q, (void *)q->next));
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269 | acc += LWIP_CHKSUM(q->payload, q->len);
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270 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
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271 | /* just executing this next line is probably faster that the if statement needed
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272 | to check whether we really need to execute it, and does no harm */
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273 | acc = FOLD_U32T(acc);
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274 | if (q->len % 2 != 0) {
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275 | swapped = !swapped;
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276 | acc = SWAP_BYTES_IN_WORD(acc);
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277 | }
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278 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
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279 | }
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280 |
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281 | if (swapped) {
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282 | acc = SWAP_BYTES_IN_WORD(acc);
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283 | }
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284 |
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285 | acc += (u32_t)lwip_htons((u16_t)proto);
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286 | acc += (u32_t)lwip_htons(proto_len);
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287 |
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288 | /* Fold 32-bit sum to 16 bits
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289 | calling this twice is probably faster than if statements... */
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290 | acc = FOLD_U32T(acc);
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291 | acc = FOLD_U32T(acc);
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292 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
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293 | return (u16_t)~(acc & 0xffffUL);
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294 | }
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295 |
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296 | #if LWIP_IPV4
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297 | /* inet_chksum_pseudo:
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298 | *
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299 | * Calculates the IPv4 pseudo Internet checksum used by TCP and UDP for a pbuf chain.
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300 | * IP addresses are expected to be in network byte order.
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301 | *
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302 | * @param p chain of pbufs over that a checksum should be calculated (ip data part)
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303 | * @param src source ip address (used for checksum of pseudo header)
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304 | * @param dst destination ip address (used for checksum of pseudo header)
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305 | * @param proto ip protocol (used for checksum of pseudo header)
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306 | * @param proto_len length of the ip data part (used for checksum of pseudo header)
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307 | * @return checksum (as u16_t) to be saved directly in the protocol header
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308 | */
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309 | u16_t
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310 | inet_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len,
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311 | const ip4_addr_t *src, const ip4_addr_t *dest)
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312 | {
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313 | u32_t acc;
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314 | u32_t addr;
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315 |
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316 | addr = ip4_addr_get_u32(src);
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317 | acc = (addr & 0xffffUL);
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318 | acc = (u32_t)(acc + ((addr >> 16) & 0xffffUL));
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319 | addr = ip4_addr_get_u32(dest);
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320 | acc = (u32_t)(acc + (addr & 0xffffUL));
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321 | acc = (u32_t)(acc + ((addr >> 16) & 0xffffUL));
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322 | /* fold down to 16 bits */
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323 | acc = FOLD_U32T(acc);
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324 | acc = FOLD_U32T(acc);
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325 |
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326 | return inet_cksum_pseudo_base(p, proto, proto_len, acc);
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327 | }
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328 | #endif /* LWIP_IPV4 */
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329 |
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330 | #if LWIP_IPV6
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331 | /**
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332 | * Calculates the checksum with IPv6 pseudo header used by TCP and UDP for a pbuf chain.
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333 | * IPv6 addresses are expected to be in network byte order.
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334 | *
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335 | * @param p chain of pbufs over that a checksum should be calculated (ip data part)
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336 | * @param proto ipv6 protocol/next header (used for checksum of pseudo header)
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337 | * @param proto_len length of the ipv6 payload (used for checksum of pseudo header)
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338 | * @param src source ipv6 address (used for checksum of pseudo header)
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339 | * @param dest destination ipv6 address (used for checksum of pseudo header)
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340 | * @return checksum (as u16_t) to be saved directly in the protocol header
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341 | */
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342 | u16_t
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343 | ip6_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len,
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344 | const ip6_addr_t *src, const ip6_addr_t *dest)
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345 | {
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346 | u32_t acc = 0;
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347 | u32_t addr;
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348 | u8_t addr_part;
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349 |
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350 | for (addr_part = 0; addr_part < 4; addr_part++) {
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351 | addr = src->addr[addr_part];
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352 | acc = (u32_t)(acc + (addr & 0xffffUL));
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353 | acc = (u32_t)(acc + ((addr >> 16) & 0xffffUL));
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354 | addr = dest->addr[addr_part];
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355 | acc = (u32_t)(acc + (addr & 0xffffUL));
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356 | acc = (u32_t)(acc + ((addr >> 16) & 0xffffUL));
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357 | }
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358 | /* fold down to 16 bits */
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359 | acc = FOLD_U32T(acc);
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360 | acc = FOLD_U32T(acc);
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361 |
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362 | return inet_cksum_pseudo_base(p, proto, proto_len, acc);
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363 | }
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364 | #endif /* LWIP_IPV6 */
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365 |
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366 | /* ip_chksum_pseudo:
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367 | *
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368 | * Calculates the IPv4 or IPv6 pseudo Internet checksum used by TCP and UDP for a pbuf chain.
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369 | * IP addresses are expected to be in network byte order.
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370 | *
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371 | * @param p chain of pbufs over that a checksum should be calculated (ip data part)
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372 | * @param src source ip address (used for checksum of pseudo header)
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373 | * @param dst destination ip address (used for checksum of pseudo header)
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374 | * @param proto ip protocol (used for checksum of pseudo header)
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375 | * @param proto_len length of the ip data part (used for checksum of pseudo header)
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376 | * @return checksum (as u16_t) to be saved directly in the protocol header
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377 | */
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378 | u16_t
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379 | ip_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len,
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380 | const ip_addr_t *src, const ip_addr_t *dest)
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381 | {
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382 | #if LWIP_IPV6
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383 | if (IP_IS_V6(dest)) {
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384 | return ip6_chksum_pseudo(p, proto, proto_len, ip_2_ip6(src), ip_2_ip6(dest));
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385 | }
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386 | #endif /* LWIP_IPV6 */
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387 | #if LWIP_IPV4 && LWIP_IPV6
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388 | else
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389 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
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390 | #if LWIP_IPV4
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391 | {
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392 | return inet_chksum_pseudo(p, proto, proto_len, ip_2_ip4(src), ip_2_ip4(dest));
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393 | }
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394 | #endif /* LWIP_IPV4 */
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395 | }
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396 |
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397 | /** Parts of the pseudo checksum which are common to IPv4 and IPv6 */
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398 | static u16_t
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399 | inet_cksum_pseudo_partial_base(struct pbuf *p, u8_t proto, u16_t proto_len,
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400 | u16_t chksum_len, u32_t acc)
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401 | {
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402 | struct pbuf *q;
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403 | int swapped = 0;
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404 | u16_t chklen;
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405 |
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406 | /* iterate through all pbuf in chain */
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407 | for (q = p; (q != NULL) && (chksum_len > 0); q = q->next) {
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408 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
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409 | (void *)q, (void *)q->next));
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410 | chklen = q->len;
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411 | if (chklen > chksum_len) {
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412 | chklen = chksum_len;
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413 | }
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414 | acc += LWIP_CHKSUM(q->payload, chklen);
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415 | chksum_len = (u16_t)(chksum_len - chklen);
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416 | LWIP_ASSERT("delete me", chksum_len < 0x7fff);
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417 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
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418 | /* fold the upper bit down */
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419 | acc = FOLD_U32T(acc);
|
---|
420 | if (q->len % 2 != 0) {
|
---|
421 | swapped = !swapped;
|
---|
422 | acc = SWAP_BYTES_IN_WORD(acc);
|
---|
423 | }
|
---|
424 | /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
|
---|
425 | }
|
---|
426 |
|
---|
427 | if (swapped) {
|
---|
428 | acc = SWAP_BYTES_IN_WORD(acc);
|
---|
429 | }
|
---|
430 |
|
---|
431 | acc += (u32_t)lwip_htons((u16_t)proto);
|
---|
432 | acc += (u32_t)lwip_htons(proto_len);
|
---|
433 |
|
---|
434 | /* Fold 32-bit sum to 16 bits
|
---|
435 | calling this twice is probably faster than if statements... */
|
---|
436 | acc = FOLD_U32T(acc);
|
---|
437 | acc = FOLD_U32T(acc);
|
---|
438 | LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
|
---|
439 | return (u16_t)~(acc & 0xffffUL);
|
---|
440 | }
|
---|
441 |
|
---|
442 | #if LWIP_IPV4
|
---|
443 | /* inet_chksum_pseudo_partial:
|
---|
444 | *
|
---|
445 | * Calculates the IPv4 pseudo Internet checksum used by TCP and UDP for a pbuf chain.
|
---|
446 | * IP addresses are expected to be in network byte order.
|
---|
447 | *
|
---|
448 | * @param p chain of pbufs over that a checksum should be calculated (ip data part)
|
---|
449 | * @param src source ip address (used for checksum of pseudo header)
|
---|
450 | * @param dst destination ip address (used for checksum of pseudo header)
|
---|
451 | * @param proto ip protocol (used for checksum of pseudo header)
|
---|
452 | * @param proto_len length of the ip data part (used for checksum of pseudo header)
|
---|
453 | * @return checksum (as u16_t) to be saved directly in the protocol header
|
---|
454 | */
|
---|
455 | u16_t
|
---|
456 | inet_chksum_pseudo_partial(struct pbuf *p, u8_t proto, u16_t proto_len,
|
---|
457 | u16_t chksum_len, const ip4_addr_t *src, const ip4_addr_t *dest)
|
---|
458 | {
|
---|
459 | u32_t acc;
|
---|
460 | u32_t addr;
|
---|
461 |
|
---|
462 | addr = ip4_addr_get_u32(src);
|
---|
463 | acc = (addr & 0xffffUL);
|
---|
464 | acc = (u32_t)(acc + ((addr >> 16) & 0xffffUL));
|
---|
465 | addr = ip4_addr_get_u32(dest);
|
---|
466 | acc = (u32_t)(acc + (addr & 0xffffUL));
|
---|
467 | acc = (u32_t)(acc + ((addr >> 16) & 0xffffUL));
|
---|
468 | /* fold down to 16 bits */
|
---|
469 | acc = FOLD_U32T(acc);
|
---|
470 | acc = FOLD_U32T(acc);
|
---|
471 |
|
---|
472 | return inet_cksum_pseudo_partial_base(p, proto, proto_len, chksum_len, acc);
|
---|
473 | }
|
---|
474 | #endif /* LWIP_IPV4 */
|
---|
475 |
|
---|
476 | #if LWIP_IPV6
|
---|
477 | /**
|
---|
478 | * Calculates the checksum with IPv6 pseudo header used by TCP and UDP for a pbuf chain.
|
---|
479 | * IPv6 addresses are expected to be in network byte order. Will only compute for a
|
---|
480 | * portion of the payload.
|
---|
481 | *
|
---|
482 | * @param p chain of pbufs over that a checksum should be calculated (ip data part)
|
---|
483 | * @param proto ipv6 protocol/next header (used for checksum of pseudo header)
|
---|
484 | * @param proto_len length of the ipv6 payload (used for checksum of pseudo header)
|
---|
485 | * @param chksum_len number of payload bytes used to compute chksum
|
---|
486 | * @param src source ipv6 address (used for checksum of pseudo header)
|
---|
487 | * @param dest destination ipv6 address (used for checksum of pseudo header)
|
---|
488 | * @return checksum (as u16_t) to be saved directly in the protocol header
|
---|
489 | */
|
---|
490 | u16_t
|
---|
491 | ip6_chksum_pseudo_partial(struct pbuf *p, u8_t proto, u16_t proto_len,
|
---|
492 | u16_t chksum_len, const ip6_addr_t *src, const ip6_addr_t *dest)
|
---|
493 | {
|
---|
494 | u32_t acc = 0;
|
---|
495 | u32_t addr;
|
---|
496 | u8_t addr_part;
|
---|
497 |
|
---|
498 | for (addr_part = 0; addr_part < 4; addr_part++) {
|
---|
499 | addr = src->addr[addr_part];
|
---|
500 | acc = (u32_t)(acc + (addr & 0xffffUL));
|
---|
501 | acc = (u32_t)(acc + ((addr >> 16) & 0xffffUL));
|
---|
502 | addr = dest->addr[addr_part];
|
---|
503 | acc = (u32_t)(acc + (addr & 0xffffUL));
|
---|
504 | acc = (u32_t)(acc + ((addr >> 16) & 0xffffUL));
|
---|
505 | }
|
---|
506 | /* fold down to 16 bits */
|
---|
507 | acc = FOLD_U32T(acc);
|
---|
508 | acc = FOLD_U32T(acc);
|
---|
509 |
|
---|
510 | return inet_cksum_pseudo_partial_base(p, proto, proto_len, chksum_len, acc);
|
---|
511 | }
|
---|
512 | #endif /* LWIP_IPV6 */
|
---|
513 |
|
---|
514 | /* ip_chksum_pseudo_partial:
|
---|
515 | *
|
---|
516 | * Calculates the IPv4 or IPv6 pseudo Internet checksum used by TCP and UDP for a pbuf chain.
|
---|
517 | *
|
---|
518 | * @param p chain of pbufs over that a checksum should be calculated (ip data part)
|
---|
519 | * @param src source ip address (used for checksum of pseudo header)
|
---|
520 | * @param dst destination ip address (used for checksum of pseudo header)
|
---|
521 | * @param proto ip protocol (used for checksum of pseudo header)
|
---|
522 | * @param proto_len length of the ip data part (used for checksum of pseudo header)
|
---|
523 | * @return checksum (as u16_t) to be saved directly in the protocol header
|
---|
524 | */
|
---|
525 | u16_t
|
---|
526 | ip_chksum_pseudo_partial(struct pbuf *p, u8_t proto, u16_t proto_len,
|
---|
527 | u16_t chksum_len, const ip_addr_t *src, const ip_addr_t *dest)
|
---|
528 | {
|
---|
529 | #if LWIP_IPV6
|
---|
530 | if (IP_IS_V6(dest)) {
|
---|
531 | return ip6_chksum_pseudo_partial(p, proto, proto_len, chksum_len, ip_2_ip6(src), ip_2_ip6(dest));
|
---|
532 | }
|
---|
533 | #endif /* LWIP_IPV6 */
|
---|
534 | #if LWIP_IPV4 && LWIP_IPV6
|
---|
535 | else
|
---|
536 | #endif /* LWIP_IPV4 && LWIP_IPV6 */
|
---|
537 | #if LWIP_IPV4
|
---|
538 | {
|
---|
539 | return inet_chksum_pseudo_partial(p, proto, proto_len, chksum_len, ip_2_ip4(src), ip_2_ip4(dest));
|
---|
540 | }
|
---|
541 | #endif /* LWIP_IPV4 */
|
---|
542 | }
|
---|
543 |
|
---|
544 | /* inet_chksum:
|
---|
545 | *
|
---|
546 | * Calculates the Internet checksum over a portion of memory. Used primarily for IP
|
---|
547 | * and ICMP.
|
---|
548 | *
|
---|
549 | * @param dataptr start of the buffer to calculate the checksum (no alignment needed)
|
---|
550 | * @param len length of the buffer to calculate the checksum
|
---|
551 | * @return checksum (as u16_t) to be saved directly in the protocol header
|
---|
552 | */
|
---|
553 |
|
---|
554 | u16_t
|
---|
555 | inet_chksum(const void *dataptr, u16_t len)
|
---|
556 | {
|
---|
557 | return (u16_t)~(unsigned int)LWIP_CHKSUM(dataptr, len);
|
---|
558 | }
|
---|
559 |
|
---|
560 | /**
|
---|
561 | * Calculate a checksum over a chain of pbufs (without pseudo-header, much like
|
---|
562 | * inet_chksum only pbufs are used).
|
---|
563 | *
|
---|
564 | * @param p pbuf chain over that the checksum should be calculated
|
---|
565 | * @return checksum (as u16_t) to be saved directly in the protocol header
|
---|
566 | */
|
---|
567 | u16_t
|
---|
568 | inet_chksum_pbuf(struct pbuf *p)
|
---|
569 | {
|
---|
570 | u32_t acc;
|
---|
571 | struct pbuf *q;
|
---|
572 | int swapped = 0;
|
---|
573 |
|
---|
574 | acc = 0;
|
---|
575 | for (q = p; q != NULL; q = q->next) {
|
---|
576 | acc += LWIP_CHKSUM(q->payload, q->len);
|
---|
577 | acc = FOLD_U32T(acc);
|
---|
578 | if (q->len % 2 != 0) {
|
---|
579 | swapped = !swapped;
|
---|
580 | acc = SWAP_BYTES_IN_WORD(acc);
|
---|
581 | }
|
---|
582 | }
|
---|
583 |
|
---|
584 | if (swapped) {
|
---|
585 | acc = SWAP_BYTES_IN_WORD(acc);
|
---|
586 | }
|
---|
587 | return (u16_t)~(acc & 0xffffUL);
|
---|
588 | }
|
---|
589 |
|
---|
590 | /* These are some implementations for LWIP_CHKSUM_COPY, which copies data
|
---|
591 | * like MEMCPY but generates a checksum at the same time. Since this is a
|
---|
592 | * performance-sensitive function, you might want to create your own version
|
---|
593 | * in assembly targeted at your hardware by defining it in lwipopts.h:
|
---|
594 | * #define LWIP_CHKSUM_COPY(dst, src, len) your_chksum_copy(dst, src, len)
|
---|
595 | */
|
---|
596 |
|
---|
597 | #if (LWIP_CHKSUM_COPY_ALGORITHM == 1) /* Version #1 */
|
---|
598 | /** Safe but slow: first call MEMCPY, then call LWIP_CHKSUM.
|
---|
599 | * For architectures with big caches, data might still be in cache when
|
---|
600 | * generating the checksum after copying.
|
---|
601 | */
|
---|
602 | u16_t
|
---|
603 | lwip_chksum_copy(void *dst, const void *src, u16_t len)
|
---|
604 | {
|
---|
605 | MEMCPY(dst, src, len);
|
---|
606 | return LWIP_CHKSUM(dst, len);
|
---|
607 | }
|
---|
608 | #endif /* (LWIP_CHKSUM_COPY_ALGORITHM == 1) */
|
---|