/*-
 * Copyright (c) 2005-2011 Daniel Braniss <danny@cs.huji.ac.il>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */
/*
 | iSCSI
 | $Id: isc_subr.c 560 2009-05-07 07:37:49Z danny $
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: releng/9.2/sys/dev/iscsi/initiator/isc_subr.c 249490 2013-04-14 22:38:28Z jpaetzel $");

#include "opt_iscsi_initiator.h"

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/ctype.h>
#include <sys/errno.h>
#include <sys/sysctl.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/socketvar.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/proc.h>
#include <sys/ioccom.h>
#include <sys/queue.h>
#include <sys/kthread.h>
#include <sys/syslog.h>
#include <sys/mbuf.h>
#include <sys/libkern.h>

#include <dev/iscsi/initiator/iscsi.h>
#include <dev/iscsi/initiator/iscsivar.h>

static MALLOC_DEFINE(M_ISC, "iSC", "iSCSI driver options");

static char *
i_strdupin(char *s, size_t maxlen)
{
     size_t	len;
     char	*p, *q;

     p = malloc(maxlen, M_ISC, M_WAITOK);
     if(copyinstr(s, p, maxlen, &len)) {
	  free(p, M_ISC);
	  return NULL;
     }
     q = malloc(len, M_ISC, M_WAITOK);
     bcopy(p, q, len);
     free(p, M_ISC);

     return q;
}
#if __FreeBSD_version < 800000
/*****************************************************************/
/*                                                               */
/* 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 uint32_t crc32Table[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
};

static __inline int
calculate_crc32c(uint32_t crc, const void *buf, size_t size)
{
     const uint8_t *p = buf;

     while (size--)
	  crc = crc32Table[(crc ^ *p++) & 0xff] ^ (crc >> 8);
     return crc;
}
#endif

static uint32_t
i_crc32c(const void *buf, size_t size, uint32_t crc)
{
     crc = crc ^ 0xffffffff;
     crc = calculate_crc32c(crc, buf, size);
     crc = crc ^ 0xffffffff;
     return crc;
}

/*
 | XXX: not finished coding
 */
int
i_setopt(isc_session_t *sp, isc_opt_t *opt)
{
     if(opt->maxRecvDataSegmentLength > 0) {
	  sp->opt.maxRecvDataSegmentLength = opt->maxRecvDataSegmentLength;
	  sdebug(2, "maxRecvDataSegmentLength=%d", sp->opt.maxRecvDataSegmentLength);
     }
     if(opt->maxXmitDataSegmentLength > 0) {
	  // danny's RFC
	  sp->opt.maxXmitDataSegmentLength = opt->maxXmitDataSegmentLength;
	  sdebug(2, "opt.maXmitDataSegmentLength=%d", sp->opt.maxXmitDataSegmentLength);
     }
     if(opt->maxBurstLength != 0) {
	  sp->opt.maxBurstLength = opt->maxBurstLength;
	  sdebug(2, "opt.maxBurstLength=%d", sp->opt.maxBurstLength);
     }

     if(opt->targetAddress != NULL) {
	  if(sp->opt.targetAddress != NULL)
	       free(sp->opt.targetAddress, M_ISC);
	  sp->opt.targetAddress = i_strdupin(opt->targetAddress, 128);
	  sdebug(2, "opt.targetAddress='%s'", sp->opt.targetAddress);
     }
     if(opt->targetName != NULL) {
	  if(sp->opt.targetName != NULL)
	       free(sp->opt.targetName, M_ISC);
	  sp->opt.targetName = i_strdupin(opt->targetName, 128);
	  sdebug(2, "opt.targetName='%s'", sp->opt.targetName);
     }
     if(opt->initiatorName != NULL) {
	  if(sp->opt.initiatorName != NULL)
	       free(sp->opt.initiatorName, M_ISC);
	  sp->opt.initiatorName = i_strdupin(opt->initiatorName, 128);
	  sdebug(2, "opt.initiatorName='%s'", sp->opt.initiatorName);
     }

     if(opt->maxluns > 0) {
	  if(opt->maxluns > ISCSI_MAX_LUNS)
	       sp->opt.maxluns = ISCSI_MAX_LUNS; // silently chop it down ...
	  sp->opt.maxluns = opt->maxluns;
	  sdebug(2, "opt.maxluns=%d", sp->opt.maxluns);
     }

     if(opt->headerDigest != NULL) {
	  sdebug(2, "opt.headerDigest='%s'", opt->headerDigest);
	  if(strcmp(opt->headerDigest, "CRC32C") == 0) {
	       sp->hdrDigest = (digest_t *)i_crc32c;
	       sdebug(2, "opt.headerDigest set");
	  }
     }
     if(opt->dataDigest != NULL) {
	  sdebug(2, "opt.dataDigest='%s'", opt->headerDigest);
	  if(strcmp(opt->dataDigest, "CRC32C") == 0) {
	       sp->dataDigest = (digest_t *)i_crc32c;
	       sdebug(2, "opt.dataDigest set");
	  }
     }

     return 0;
}

void
i_freeopt(isc_opt_t *opt)
{
     debug_called(8);

     if(opt->targetAddress != NULL) {
	  free(opt->targetAddress, M_ISC);
	  opt->targetAddress = NULL;
     }
     if(opt->targetName != NULL) {
	  free(opt->targetName, M_ISC);
	  opt->targetName = NULL;
     }
     if(opt->initiatorName != NULL) {
	  free(opt->initiatorName, M_ISC);
	  opt->initiatorName = NULL;
     }
}
