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Commit 456d1311 authored by Rusty Russell's avatar Rusty Russell
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Added Castagnoli CRC routines, expand interface.

parent 96b6d6f1
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ccan/crc/_info.c
View file @ 456d1311
......@@ -3,8 +3,8 @@
/**
* crc - routines for crc of bytes
*
* Cyclic Redundancy Check routines. They are reasonably fasts
* checksum routine, but not suitable for cryptographic use.
* Cyclic Redundancy Check routines. These are reasonably fast
* checksum routines, but not suitable for cryptographic use.
*
* They are useful for simple error detection, eg. a 32-bit CRC will
* detect a single error burst of up to 32 bits.
......@@ -21,12 +21,12 @@
* "Prints 32 bit CRC of the string\n", argv[0]);
* exit(1);
* }
* printf("0x%08x\n", crc32(argv[1], strlen(argv[1])));
* printf("0x%08x\n", crc32c(argv[1], strlen(argv[1])));
* exit(0);
* }
*
* Licence: Public Domain
* Author: Gary S. Brown
* Licence: GPL (v2 or later)
* Author: Gary S. Brown, Clay Haapala
* Maintainer: Rusty Russell <rusty@rustcorp.com.au>
*/
int main(int argc, char *argv[])
......
ccan/crc/crc.c
View file @ 456d1311
/*-
/* 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,
......@@ -89,16 +156,20 @@ static const uint32_t crc32_tab[] = {
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;
}
ccan/crc/crc.h
View file @ 456d1311
......@@ -4,12 +4,80 @@
#include <stdlib.h>
/**
* crc32 - 32 bit crc of string of bytes
* crc32c - Castagnoli 32 bit crc of string of bytes
* @start_crc: the initial crc (usually 0)
* @buf: pointer to bytes
* @size: length of buffer
*
* If you don't know what crc32 to use, use this one: it's the best.
*
* @Article{castagnoli-crc,
* author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
* title = {{Optimization of Cyclic Redundancy-Check Codes with 24
* and 32 Parity Bits}},
* journal = IEEE Transactions on Communication,
* year = {1993},
* volume = {41},
* number = {6},
* pages = {},
* month = {June},
*}
* 32 bit CRC checksum using polynomial
* X^32+X^28+X^27+X^26+X^25+X^23+X^22+X^20+X^19+X^18+X^14+X^13+X^11+X^10+X^9+X^8+X^6+X^0.
*
* You can calculate the CRC of non-contiguous arrays by passing @start_crc
* as 0 the first time, and the current crc result from then on.
*
* Example:
* // Check that iovec has the crc we expect (Castagnoli version)
* bool check_crc(uint32_t expected, const struct iovec *iov, int iovcnt)
* {
* uint32_t crc = 0;
* while (iovcnt >= 0) {
* crc = crc32c(crc, iov->iov_base, iov->iov_len);
* iov++;
* }
* return crc == expected;
* }
*/
uint32_t crc32c(uint32_t start_crc, const void *buf, size_t size);
/**
* crc32c_table - Get the Castagnoli CRC table
*
* For special effects, you might want direct access to the table; this is
* the standard 256-entry table for this algorithm.
*
* In theory, this might need to malloc(), and thus return NULL.
*
* Example:
* // This dumb code only handles Castagnoli, so assert that here.
* void check_user_crc_table(const uint32_t *usertab)
* {
* const uint32_t *ctab = crc32c_table();
* if (!ieee_tab || memcmp(ieee_tab, usertab, 1024) != 0)
* abort();
* }
*/
const uint32_t *crc32c_table(void);
/**
* crc32_ieee - IEEE 802.3 32 bit crc of string of bytes
* @start_crc: the initial crc (usually 0)
* @buf: pointer to bytes
* @size: length of buffer
*
* 32 bit CRC checksum using polynomial
* 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.
*
* See crc32c() for details.
*/
uint32_t crc32_ieee(uint32_t start_crc, const void *buf, size_t size);
/**
* crc32_ieee_table - Get the IEEE 802.3 CRC table
*
* See crc32c_table() for details.
*/
uint32_t crc32(const void *buf, size_t size);
const uint32_t *crc32_ieee_table(void);
#endif /* CCAN_CRC_H */
ccan/crc/test/api.c
View file @ 456d1311
......@@ -4,7 +4,57 @@
#include <string.h>
/* Expected CRCs of 4 of each char. */
static uint32_t crc_expect[] = {
static uint32_t crcc_expect[] = {
0x00000000, 0x99cd23b2, 0x36763195, 0xafbb1227, 0x6cec632a, 0xf5214098,
0x5a9a52bf, 0xc357710d, 0xd9d8c654, 0x4015e5e6, 0xefaef7c1, 0x7663d473,
0xb534a57e, 0x2cf986cc, 0x834294eb, 0x1a8fb759, 0xb65dfa59, 0x2f90d9eb,
0x802bcbcc, 0x19e6e87e, 0xdab19973, 0x437cbac1, 0xecc7a8e6, 0x750a8b54,
0x6f853c0d, 0xf6481fbf, 0x59f30d98, 0xc03e2e2a, 0x03695f27, 0x9aa47c95,
0x351f6eb2, 0xacd24d00, 0x69578243, 0xf09aa1f1, 0x5f21b3d6, 0xc6ec9064,
0x05bbe169, 0x9c76c2db, 0x33cdd0fc, 0xaa00f34e, 0xb08f4417, 0x294267a5,
0x86f97582, 0x1f345630, 0xdc63273d, 0x45ae048f, 0xea1516a8, 0x73d8351a,
0xdf0a781a, 0x46c75ba8, 0xe97c498f, 0x70b16a3d, 0xb3e61b30, 0x2a2b3882,
0x85902aa5, 0x1c5d0917, 0x06d2be4e, 0x9f1f9dfc, 0x30a48fdb, 0xa969ac69,
0x6a3edd64, 0xf3f3fed6, 0x5c48ecf1, 0xc585cf43, 0xd2af0486, 0x4b622734,
0xe4d93513, 0x7d1416a1, 0xbe4367ac, 0x278e441e, 0x88355639, 0x11f8758b,
0x0b77c2d2, 0x92bae160, 0x3d01f347, 0xa4ccd0f5, 0x679ba1f8, 0xfe56824a,
0x51ed906d, 0xc820b3df, 0x64f2fedf, 0xfd3fdd6d, 0x5284cf4a, 0xcb49ecf8,
0x081e9df5, 0x91d3be47, 0x3e68ac60, 0xa7a58fd2, 0xbd2a388b, 0x24e71b39,
0x8b5c091e, 0x12912aac, 0xd1c65ba1, 0x480b7813, 0xe7b06a34, 0x7e7d4986,
0xbbf886c5, 0x2235a577, 0x8d8eb750, 0x144394e2, 0xd714e5ef, 0x4ed9c65d,
0xe162d47a, 0x78aff7c8, 0x62204091, 0xfbed6323, 0x54567104, 0xcd9b52b6,
0x0ecc23bb, 0x97010009, 0x38ba122e, 0xa177319c, 0x0da57c9c, 0x94685f2e,
0x3bd34d09, 0xa21e6ebb, 0x61491fb6, 0xf8843c04, 0x573f2e23, 0xcef20d91,
0xd47dbac8, 0x4db0997a, 0xe20b8b5d, 0x7bc6a8ef, 0xb891d9e2, 0x215cfa50,
0x8ee7e877, 0x172acbc5, 0xa0b27ffd, 0x397f5c4f, 0x96c44e68, 0x0f096dda,
0xcc5e1cd7, 0x55933f65, 0xfa282d42, 0x63e50ef0, 0x796ab9a9, 0xe0a79a1b,
0x4f1c883c, 0xd6d1ab8e, 0x1586da83, 0x8c4bf931, 0x23f0eb16, 0xba3dc8a4,
0x16ef85a4, 0x8f22a616, 0x2099b431, 0xb9549783, 0x7a03e68e, 0xe3cec53c,
0x4c75d71b, 0xd5b8f4a9, 0xcf3743f0, 0x56fa6042, 0xf9417265, 0x608c51d7,
0xa3db20da, 0x3a160368, 0x95ad114f, 0x0c6032fd, 0xc9e5fdbe, 0x5028de0c,
0xff93cc2b, 0x665eef99, 0xa5099e94, 0x3cc4bd26, 0x937faf01, 0x0ab28cb3,
0x103d3bea, 0x89f01858, 0x264b0a7f, 0xbf8629cd, 0x7cd158c0, 0xe51c7b72,
0x4aa76955, 0xd36a4ae7, 0x7fb807e7, 0xe6752455, 0x49ce3672, 0xd00315c0,
0x135464cd, 0x8a99477f, 0x25225558, 0xbcef76ea, 0xa660c1b3, 0x3fade201,
0x9016f026, 0x09dbd394, 0xca8ca299, 0x5341812b, 0xfcfa930c, 0x6537b0be,
0x721d7b7b, 0xebd058c9, 0x446b4aee, 0xdda6695c, 0x1ef11851, 0x873c3be3,
0x288729c4, 0xb14a0a76, 0xabc5bd2f, 0x32089e9d, 0x9db38cba, 0x047eaf08,
0xc729de05, 0x5ee4fdb7, 0xf15fef90, 0x6892cc22, 0xc4408122, 0x5d8da290,
0xf236b0b7, 0x6bfb9305, 0xa8ace208, 0x3161c1ba, 0x9edad39d, 0x0717f02f,
0x1d984776, 0x845564c4, 0x2bee76e3, 0xb2235551, 0x7174245c, 0xe8b907ee,
0x470215c9, 0xdecf367b, 0x1b4af938, 0x8287da8a, 0x2d3cc8ad, 0xb4f1eb1f,
0x77a69a12, 0xee6bb9a0, 0x41d0ab87, 0xd81d8835, 0xc2923f6c, 0x5b5f1cde,
0xf4e40ef9, 0x6d292d4b, 0xae7e5c46, 0x37b37ff4, 0x98086dd3, 0x01c54e61,
0xad170361, 0x34da20d3, 0x9b6132f4, 0x02ac1146, 0xc1fb604b, 0x583643f9,
0xf78d51de, 0x6e40726c, 0x74cfc535, 0xed02e687, 0x42b9f4a0, 0xdb74d712,
0x1823a61f, 0x81ee85ad, 0x2e55978a, 0xb798b438
};
static uint32_t crcc_zero_expect[] = {
0x00000000, 0x00000000, 0x00000000, 0x00000000,
};
static uint32_t crc_ieee_expect[] = {
0x2144df1c, 0xf626d399, 0x54f1c057, 0x8393ccd2, 0xca2ee18a, 0x1d4ced0f,
0xbf9bfec1, 0x68f9f244, 0x2ce1a471, 0xfb83a8f4, 0x5954bb3a, 0x8e36b7bf,
0xc78b9ae7, 0x10e99662, 0xb23e85ac, 0x655c8929, 0x3a0e29c6, 0xed6c2543,
......@@ -50,20 +100,39 @@ static uint32_t crc_expect[] = {
0x5d28ec31, 0x8a4ae0b4, 0x289df37a, 0xffffffff,
};
int main(int argc, char *argv[])
static uint32_t crc_ieee_zero_expect[] = {
0x00000000, 0xd202ef8d, 0x41d912ff, 0xff41d912
};
/* Runs 517 tests. */
static void test_crc32(uint32_t (*crc)(uint32_t, const void *, size_t),
const uint32_t *(*crc_table)(void),
const uint32_t zero_expect[4],
const uint32_t four_char_expect[256],
const uint32_t *table_expect)
{
unsigned int i;
char c[4] = { 0 };
plan_tests(260);
ok1(crc32(c, 0) == 0x00000000);
ok1(crc32(c, 1) == 0xd202ef8d);
ok1(crc32(c, 2) == 0x41d912ff);
ok1(crc32(c, 3) == 0xff41d912);
for (i = 0; i < 4; i++)
ok1(crc(0, c, i) == zero_expect[i]);
for (i = 0; i < 256; i++) {
memset(c, i, sizeof(c));
ok1(crc32(c, sizeof(c)) == crc_expect[i]);
ok1(crc(0, c, sizeof(c)) == four_char_expect[i]);
/* CRC in two parts should give same answer. */
ok1(crc(crc(0, c, i%5), c+i%5, 4 - (i%5))
== four_char_expect[i]);
}
ok1(memcmp(crc_table(), table_expect, 1024) == 0);
}
int main(int argc, char *argv[])
{
plan_tests(517 * 2);
test_crc32(crc32c, crc32c_table,
crcc_zero_expect, crcc_expect, crc32c_tab);
test_crc32(crc32_ieee, crc32_ieee_table,
crc_ieee_zero_expect, crc_ieee_expect, crc32_ieee_tab);
return exit_status();
}
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