-/*-
+/* crc32_ieee code:
* COPYRIGHT (C) 1986 Gary S. Brown. You may use this program, or
* code or tables extracted from it, as desired without restriction.
- *
- * First, the polynomial itself and its table of feedback terms. The
- * polynomial is
- * X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0
- *
- * Note that we take it "backwards" and put the highest-order term in
- * the lowest-order bit. The X^32 term is "implied"; the LSB is the
- * X^31 term, etc. The X^0 term (usually shown as "+1") results in
- * the MSB being 1
- *
- * Note that the usual hardware shift register implementation, which
- * is what we're using (we're merely optimizing it by doing eight-bit
- * chunks at a time) shifts bits into the lowest-order term. In our
- * implementation, that means shifting towards the right. Why do we
- * do it this way? Because the calculated CRC must be transmitted in
- * order from highest-order term to lowest-order term. UARTs transmit
- * characters in order from LSB to MSB. By storing the CRC this way
- * we hand it to the UART in the order low-byte to high-byte; the UART
- * sends each low-bit to hight-bit; and the result is transmission bit
- * by bit from highest- to lowest-order term without requiring any bit
- * shuffling on our part. Reception works similarly
- *
- * The feedback terms table consists of 256, 32-bit entries. Notes
- *
- * The table can be generated at runtime if desired; code to do so
- * is shown later. It might not be obvious, but the feedback
- * terms simply represent the results of eight shift/xor opera
- * tions for all combinations of data and CRC register values
- *
- * The values must be right-shifted by eight bits by the "updcrc
- * logic; the shift must be unsigned (bring in zeroes). On some
- * hardware you could probably optimize the shift in assembler by
- * using byte-swap instructions
- * polynomial $edb88320
- *
- *
- * CRC32 code derived from work by Gary S. Brown.
*/
+
+/* crc32c code taken from 2.6.29 Linux kernel crypto/crc32c.c:
+ * Copyright (c) 2004 Cisco Systems, Inc.
+ * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version. */
+
#include "crc.h"
#include <stdbool.h>
#include <stdlib.h>
-static const uint32_t crc32_tab[] = {
+/*
+ * This is the CRC-32C table
+ * Generated with:
+ * width = 32 bits
+ * poly = 0x1EDC6F41
+ * reflect input bytes = true
+ * reflect output bytes = true
+ */
+static const uint32_t crc32c_tab[] = {
+ 0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4,
+ 0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB,
+ 0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B,
+ 0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24,
+ 0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B,
+ 0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384,
+ 0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54,
+ 0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B,
+ 0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A,
+ 0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35,
+ 0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5,
+ 0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA,
+ 0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45,
+ 0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A,
+ 0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A,
+ 0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595,
+ 0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48,
+ 0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957,
+ 0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687,
+ 0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198,
+ 0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927,
+ 0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38,
+ 0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8,
+ 0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7,
+ 0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096,
+ 0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789,
+ 0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859,
+ 0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46,
+ 0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9,
+ 0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6,
+ 0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36,
+ 0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829,
+ 0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C,
+ 0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93,
+ 0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043,
+ 0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C,
+ 0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3,
+ 0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC,
+ 0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C,
+ 0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033,
+ 0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652,
+ 0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D,
+ 0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D,
+ 0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982,
+ 0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D,
+ 0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622,
+ 0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2,
+ 0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED,
+ 0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530,
+ 0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F,
+ 0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF,
+ 0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0,
+ 0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F,
+ 0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540,
+ 0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90,
+ 0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F,
+ 0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE,
+ 0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1,
+ 0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321,
+ 0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E,
+ 0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81,
+ 0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E,
+ 0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E,
+ 0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351
+};
+
+/*
+ * Steps through buffer one byte at at time, calculates reflected
+ * crc using table.
+ */
+uint32_t crc32c(uint32_t crc, const void *buf, size_t size)
+{
+ const uint8_t *p = buf;
+
+ while (size--)
+ crc = crc32c_tab[(crc ^ *p++) & 0xFFL] ^ (crc >> 8);
+
+ return crc;
+}
+
+const uint32_t *crc32c_table(void)
+{
+ return crc32c_tab;
+}
+
+static const uint32_t crc32_ieee_tab[] = {
0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};
-uint32_t crc32(const void *buf, size_t size)
+uint32_t crc32_ieee(uint32_t crc, const void *buf, size_t size)
{
const uint8_t *p;
- uint32_t crc;
p = buf;
- crc = ~0U;
+ crc ^= ~0U;
while (size--)
- crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
+ crc = crc32_ieee_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8);
return crc ^ ~0U;
}
+
+const uint32_t *crc32_ieee_table(void)
+{
+ return crc32_ieee_tab;
+}
projects / ccan / blobdiff