 fae366401b
			
		
	
	
	fae366401b
	
	
	
		
			
			Removed coding style issue: space before tabs. Signed-off-by: Mati Vait <mativait@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
		
			
				
	
	
		
			260 lines
		
	
	
	
		
			8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			260 lines
		
	
	
	
		
			8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Cryptographic API.
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|  *
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|  * CRC32C chksum
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|  *
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|  *@Article{castagnoli-crc,
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|  * author =       { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
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|  * title =        {{Optimization of Cyclic Redundancy-Check Codes with 24
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|  *                 and 32 Parity Bits}},
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|  * journal =      IEEE Transactions on Communication,
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|  * year =         {1993},
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|  * volume =       {41},
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|  * number =       {6},
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|  * pages =        {},
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|  * month =        {June},
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|  *}
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|  * Used by the iSCSI driver, possibly others, and derived from the
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|  * the iscsi-crc.c module of the linux-iscsi driver at
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|  * http://linux-iscsi.sourceforge.net.
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|  *
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|  * Following the example of lib/crc32, this function is intended to be
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|  * flexible and useful for all users.  Modules that currently have their
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|  * own crc32c, but hopefully may be able to use this one are:
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|  *  net/sctp (please add all your doco to here if you change to
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|  *            use this one!)
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|  *  <endoflist>
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|  *
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|  * Copyright (c) 2004 Cisco Systems, Inc.
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|  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
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|  *
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|  * This program is free software; you can redistribute it and/or modify it
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|  * under the terms of the GNU General Public License as published by the Free
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|  * Software Foundation; either version 2 of the License, or (at your option)
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|  * any later version.
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|  *
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|  */
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| 
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| #include <crypto/internal/hash.h>
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| #include <linux/init.h>
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| #include <linux/module.h>
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| #include <linux/string.h>
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| #include <linux/kernel.h>
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| 
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| #define CHKSUM_BLOCK_SIZE	1
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| #define CHKSUM_DIGEST_SIZE	4
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| 
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| struct chksum_ctx {
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| 	u32 key;
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| };
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| 
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| struct chksum_desc_ctx {
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| 	u32 crc;
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| };
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| 
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| /*
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|  * This is the CRC-32C table
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|  * Generated with:
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|  * width = 32 bits
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|  * poly = 0x1EDC6F41
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|  * reflect input bytes = true
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|  * reflect output bytes = true
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|  */
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| 
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| static const u32 crc32c_table[256] = {
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| 	0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
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| 	0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
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| 	0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
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| 	0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
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| 	0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
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| 	0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
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| 	0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
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| 	0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
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| 	0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
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| 	0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
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| 	0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
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| 	0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
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| 	0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
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| 	0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
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| 	0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
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| 	0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
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| 	0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
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| 	0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
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| 	0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
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| 	0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
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| 	0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
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| 	0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
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| 	0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
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| 	0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
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| 	0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
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| 	0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
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| 	0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
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| 	0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
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| 	0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
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| 	0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
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| 	0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
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| 	0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
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| 	0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
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| 	0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
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| 	0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
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| 	0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
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| 	0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
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| 	0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
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| 	0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
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| 	0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
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| 	0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
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| 	0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
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| 	0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
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| 	0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
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| 	0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
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| 	0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
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| 	0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
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| 	0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
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| 	0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
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| 	0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
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| 	0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
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| 	0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
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| 	0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
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| 	0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
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| 	0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
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| 	0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
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| 	0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
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| 	0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
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| 	0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
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| 	0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
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| 	0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
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| 	0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
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| 	0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
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| 	0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
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| };
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| 
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| /*
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|  * Steps through buffer one byte at at time, calculates reflected
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|  * crc using table.
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|  */
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| 
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| static u32 crc32c(u32 crc, const u8 *data, unsigned int length)
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| {
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| 	while (length--)
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| 		crc = crc32c_table[(crc ^ *data++) & 0xFFL] ^ (crc >> 8);
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| 
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| 	return crc;
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| }
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| 
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| /*
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|  * Steps through buffer one byte at at time, calculates reflected
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|  * crc using table.
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|  */
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| 
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| static int chksum_init(struct shash_desc *desc)
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| {
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| 	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
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| 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
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| 
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| 	ctx->crc = mctx->key;
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| 
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| 	return 0;
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| }
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| 
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| /*
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|  * Setting the seed allows arbitrary accumulators and flexible XOR policy
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|  * If your algorithm starts with ~0, then XOR with ~0 before you set
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|  * the seed.
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|  */
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| static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
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| 			 unsigned int keylen)
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| {
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| 	struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
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| 
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| 	if (keylen != sizeof(mctx->key)) {
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| 		crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
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| 		return -EINVAL;
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| 	}
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| 	mctx->key = le32_to_cpu(*(__le32 *)key);
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| 	return 0;
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| }
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| 
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| static int chksum_update(struct shash_desc *desc, const u8 *data,
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| 			 unsigned int length)
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| {
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| 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
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| 
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| 	ctx->crc = crc32c(ctx->crc, data, length);
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| 	return 0;
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| }
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| 
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| static int chksum_final(struct shash_desc *desc, u8 *out)
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| {
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| 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
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| 
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| 	*(__le32 *)out = ~cpu_to_le32p(&ctx->crc);
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| 	return 0;
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| }
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| 
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| static int __chksum_finup(u32 *crcp, const u8 *data, unsigned int len, u8 *out)
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| {
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| 	*(__le32 *)out = ~cpu_to_le32(crc32c(*crcp, data, len));
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| 	return 0;
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| }
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| 
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| static int chksum_finup(struct shash_desc *desc, const u8 *data,
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| 			unsigned int len, u8 *out)
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| {
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| 	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
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| 
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| 	return __chksum_finup(&ctx->crc, data, len, out);
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| }
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| 
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| static int chksum_digest(struct shash_desc *desc, const u8 *data,
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| 			 unsigned int length, u8 *out)
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| {
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| 	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
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| 
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| 	return __chksum_finup(&mctx->key, data, length, out);
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| }
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| 
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| static int crc32c_cra_init(struct crypto_tfm *tfm)
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| {
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| 	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
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| 
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| 	mctx->key = ~0;
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| 	return 0;
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| }
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| 
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| static struct shash_alg alg = {
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| 	.digestsize		=	CHKSUM_DIGEST_SIZE,
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| 	.setkey			=	chksum_setkey,
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| 	.init		=	chksum_init,
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| 	.update		=	chksum_update,
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| 	.final		=	chksum_final,
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| 	.finup		=	chksum_finup,
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| 	.digest		=	chksum_digest,
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| 	.descsize		=	sizeof(struct chksum_desc_ctx),
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| 	.base			=	{
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| 		.cra_name		=	"crc32c",
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| 		.cra_driver_name	=	"crc32c-generic",
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| 		.cra_priority		=	100,
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| 		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
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| 		.cra_alignmask		=	3,
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| 		.cra_ctxsize		=	sizeof(struct chksum_ctx),
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| 		.cra_module		=	THIS_MODULE,
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| 		.cra_init		=	crc32c_cra_init,
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| 	}
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| };
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| 
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| static int __init crc32c_mod_init(void)
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| {
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| 	return crypto_register_shash(&alg);
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| }
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| 
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| static void __exit crc32c_mod_fini(void)
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| {
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| 	crypto_unregister_shash(&alg);
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| }
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| 
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| module_init(crc32c_mod_init);
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| module_exit(crc32c_mod_fini);
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| 
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| MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
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| MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations wrapper for lib/crc32c");
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| MODULE_LICENSE("GPL");
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