bluesky/crc32c.c

   1 /* Blue Sky: File Systems in the Cloud
   2  *
   3  * This file implements the Castagnoli CRC-32 computation, and is taken from
   4  * crypto/crc32c.c in the Linux kernel:
   5  *
   6  * Copyright (c) 2004 Cisco Systems, Inc.
   7  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License as published by the Free
  11  * Software Foundation; either version 2 of the License, or (at your option)
  12  * any later version.
  13  *
  14  * Adapted by Michael Vrable to fit with BlueSky.
  15  */
  16
  17 #include <stdint.h>
  18 #include "bluesky-private.h"
  19
  20 /* Generator polynomial is 0x1edc6f41; input and output are reflected.  The
  21  * recommended starting value for the accumulator is ~0, and the bits of the
  22  * CRC are inverted at the end as well. */
  23
  24 static const uint32_t crc32c_table[256] = {
  25     0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
  26     0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
  27     0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
  28     0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
  29     0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
  30     0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
  31     0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
  32     0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
  33     0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
  34     0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
  35     0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
  36     0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
  37     0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
  38     0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
  39     0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
  40     0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
  41     0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
  42     0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
  43     0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
  44     0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
  45     0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
  46     0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
  47     0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
  48     0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
  49     0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
  50     0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
  51     0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
  52     0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
  53     0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
  54     0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
  55     0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
  56     0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
  57     0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
  58     0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
  59     0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
  60     0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
  61     0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
  62     0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
  63     0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
  64     0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
  65     0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
  66     0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
  67     0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
  68     0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
  69     0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
  70     0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
  71     0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
  72     0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
  73     0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
  74     0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
  75     0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
  76     0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
  77     0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
  78     0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
  79     0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
  80     0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
  81     0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
  82     0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
  83     0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
  84     0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
  85     0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
  86     0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
  87     0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
  88     0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
  89 };
  90
  91 /*
  92  * Steps through buffer one byte at at time, calculates reflected
  93  * crc using table.
  94  */
  95
  96 uint32_t crc32c(uint32_t crc, const char *buf, unsigned int length)
  97 {
  98     const uint8_t *data = (const uint8_t *)buf;
  99
 100     while (length--)
 101         crc = crc32c_table[(crc ^ *data++) & 0xFFL] ^ (crc >> 8);
 102
 103     return crc;
 104 }
 105
 106 uint32_t crc32c_finalize(uint32_t crc)
 107 {
 108     return ~GUINT32_TO_LE(crc);
 109 }