3a39201543
It is not real zero-copy since the data is still copied in the kernel, but it avoids copying the data inside libiscsi as well as in the callback. For SCSI tasks that will return data from the target, the application can now specify application buffers for libiscsi to read the data directly into. This is done by calling scsi_task_add_data_in_buffer(task, ... These buffers need not be linear, you can specify different areas to read into by calling this function several times. See examples/iscsiclient.c for an example.
117 lines
5.6 KiB
C
117 lines
5.6 KiB
C
/*
|
|
Copyright (C) 2010 by Ronnie Sahlberg <ronniesahlberg@gmail.com>
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU Lesser General Public License as published by
|
|
the Free Software Foundation; either version 2.1 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with this program; if not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
#include <unistd.h>
|
|
#include "iscsi.h"
|
|
#include "iscsi-private.h"
|
|
|
|
/*****************************************************************/
|
|
/* */
|
|
/* CRC LOOKUP TABLE */
|
|
/* ================ */
|
|
/* The following CRC lookup table was generated automagically */
|
|
/* by the Rocksoft^tm Model CRC Algorithm Table Generation */
|
|
/* Program V1.0 using the following model parameters: */
|
|
/* */
|
|
/* Width : 4 bytes. */
|
|
/* Poly : 0x1EDC6F41L */
|
|
/* Reverse : TRUE. */
|
|
/* */
|
|
/* For more information on the Rocksoft^tm Model CRC Algorithm, */
|
|
/* see the document titled "A Painless Guide to CRC Error */
|
|
/* Detection Algorithms" by Ross Williams */
|
|
/* (ross@guest.adelaide.edu.au.). This document is likely to be */
|
|
/* in the FTP archive "ftp.adelaide.edu.au/pub/rocksoft". */
|
|
/* */
|
|
/*****************************************************************/
|
|
|
|
static unsigned long crctable[256] = {
|
|
0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
|
|
0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
|
|
0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
|
|
0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
|
|
0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
|
|
0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
|
|
0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
|
|
0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
|
|
0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
|
|
0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
|
|
0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
|
|
0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
|
|
0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
|
|
0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
|
|
0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
|
|
0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
|
|
0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
|
|
0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
|
|
0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
|
|
0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
|
|
0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
|
|
0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
|
|
0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
|
|
0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
|
|
0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
|
|
0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
|
|
0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
|
|
0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
|
|
0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
|
|
0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
|
|
0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
|
|
0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
|
|
0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
|
|
0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
|
|
0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
|
|
0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
|
|
0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
|
|
0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
|
|
0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
|
|
0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
|
|
0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
|
|
0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
|
|
0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
|
|
0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
|
|
0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
|
|
0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
|
|
0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
|
|
0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
|
|
0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
|
|
0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
|
|
0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
|
|
0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
|
|
0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
|
|
0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
|
|
0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
|
|
0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
|
|
0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
|
|
0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
|
|
0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
|
|
0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
|
|
0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
|
|
0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
|
|
0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
|
|
0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
|
|
};
|
|
|
|
unsigned long crc32c(char *buf, int len)
|
|
{
|
|
unsigned long crc = 0xffffffff;
|
|
while (len-- > 0) {
|
|
crc = (crc>>8) ^ crctable[(crc ^ (*buf++)) & 0xFF];
|
|
}
|
|
return crc^0xffffffff;
|
|
}
|
|
|