/*
 * wnaspi32.cpp
 *
 * This source file for Win 2K/XP exists to make:
 *
 *	LoadLibrary("wnaspi32.dll");
 *
 * work enough like it did in Win 9X/ME to allow
 * trivial apps to function.
 *
 * Our "wnaspi32.h" appears unattributed, unlicensed,
 * and without copyright, precisely as it reached us
 * via Google.
 *
 * msdn.microsoft.com probably documents what our
 * history of pain has taught us of this interface.
 *
 * Bugs include:
 *
 *	Misbehaviour above 2 GiB per CDB.
 *
 *	Drive letter = ('C' + SRB_Target).
 *	No CloseHandle.
 *	CreateFile called til success, for each cdb sent to a drive letter.
 *
 *	Auto sense data echod out stderr, never passed back.
 *	No check for unused for the fields not copied, e.g. SRB_SenseLen.
 *
 *	x00 SC_HA_INQUIRY never becomes IOCTL_SCSI_GET_CAPABILITIES
 *	x02 SC_EXEC_SCSI_CMD never becomes IOCTL_SCSI_PASS_THROUGH_DIRECT
 *
 *	x80 SS_INVALID_CMD includes x08 SC_GETSET_TIMEOUTS
 *	x80 SS_INVALID_CMD includes x07 SC_RESCAN_SCSI_BUS
 *	x80 SS_INVALID_CMD includes x06 SC_GET_DISK_INFO
 *	x80 SS_INVALID_CMD includes x05 SC_SET_HA_PARMS
 *	x80 SS_INVALID_CMD includes x04 SC_RESET_DEV
 *	x80 SS_INVALID_CMD includes x03 SC_ABORT_SRB
 *	x80 SS_INVALID_CMD includes x01 SC_GET_DEV_TYPE
 */

#include "windows.h"
#include "ntddscsi.hpp"

#include <stddef.h>
#include <stdio.h>

#include "gccscsi.h"

#include "wnaspi32.hpp"

#define TARGET_COUNT (1 << 5) /* enough for 'C' .. 'Z' and one host */
int devs[TARGET_COUNT];

extern "C" {
extern DWORD GetASPI32SupportInfo(void);
extern DWORD SendASPI32Command(LPSRB v);
}

__declspec(dllexport)
extern DWORD GetASPI32SupportInfo(void)
{
	BYTE srbStatus = SS_NO_ADAPTERS; /* xE8 */
	BYTE haCount = ('Z' - 'A' + 1);
	srbStatus = SS_COMP; /* x01 */
	return ((srbStatus << 8) | haCount);
}

static BYTE ha_inquiry(SRB_HAInquiry * shai)
{
	WORD alignment_mask = (4 * Ki);
	BYTE may_count_data = 0x01;
	DWORD max_length = (64 * Ki);

	shai->HA_Count = 1;

	shai->HA_SCSI_ID = (TARGET_COUNT - 1);
	memset(&shai->HA_ManagerId[0], '\0', sizeof shai->HA_ManagerId);
	memset(&shai->HA_Identifier[0], '\0', sizeof shai->HA_Identifier);
	memset(&shai->HA_Unique[0], '\0', sizeof shai->HA_Unique);

	strncpy((char *) &shai->HA_ManagerId[0], "Wnaspi32.dll", sizeof shai->HA_ManagerId);
	strncpy((char *) &shai->HA_Identifier[0], "Slow SPT (not SPTD)", sizeof shai->HA_Identifier);

	* (WORD *) &shai->HA_Unique[0x00] = alignment_mask;
	* (BYTE *) &shai->HA_Unique[0x02] = may_count_data;
	* (BYTE *) &shai->HA_Unique[0x03] = TARGET_COUNT;
	* (DWORD *) &shai->HA_Unique[0x04] = max_length;

	return SS_COMP; /* x01 */
}

static BYTE exec_scsi_cmd(SRB_ExecSCSICmd * sesc)
{
	BYTE SRB_Target = sesc->SRB_Target;
	BYTE SRB_Lun = sesc->SRB_Lun;

	int letter = ('C' + SRB_Target);
	if (!(('A' <= letter) & (letter <= 'Z'))) return SS_NO_DEVICE; /* x82 */
	if (SRB_Lun != 0x00) return SS_NO_DEVICE; /* x82 */

	int dev = devs[SRB_Target];
	if (dev == 0) {
		char name[123] = "//./A:";
		sprintf(&name[0], "\\\\.\\%c:", letter);
		dev = sp_open(&name[0]);
	}
	if (dev == 0) return SS_NO_DEVICE; /* x82 */

	char * cdbChars = (char *) &sesc->CDBByte[0];
	int cdbLength = sesc->SRB_CDBLen;
	char * inChars = (char *) sesc->SRB_BufPointer;
	char * outChars = inChars;
	int maxLength = (int) sesc->SRB_BufLen;

	BYTE SRB_Flags = sesc->SRB_Flags;
	BYTE SRB_Flags_In_Out = (SRB_Flags & (SRB_DIR_OUT|SRB_DIR_IN)); /* x18 */
	if (maxLength == 0) {
		outChars = inChars = NULL;
	} else if (SRB_Flags_In_Out == SRB_DIR_IN) { /* x08 */
		outChars = NULL;
	} else if (SRB_Flags_In_Out == SRB_DIR_OUT) { /* x10 */
		inChars = NULL;
	} else {
		return SS_INVALID_SRB; /* xE0 */
	}

	int rc = sp_say(dev, cdbChars, cdbLength, outChars, inChars, maxLength);

	if (rc == 0) {
		sesc->SRB_HaStat = HASTAT_OK; /* x00 */
		sesc->SRB_TargStat = 0x00; /* good */
		return SS_COMP; /* x01 */
	}

	if (0 < rc) {
		sesc->SRB_HaStat = HASTAT_DO_DU; /* x12 */
		sesc->SRB_TargStat = 0x00; /* good */
		return SS_ERR; /* x04 */
	}

	sesc->SRB_HaStat = HASTAT_BUS_FREE; /* x13 */
	sesc->SRB_TargStat = 0x00; /* good */
	return SS_ERR; /* x04 */
}

__declspec(dllexport)
extern DWORD SendASPI32Command(LPSRB v)
{
	BYTE srbStatus = SS_INVALID_CMD; /* x80 */
	SRB_Abort * sa = (SRB_Abort *) v;
	if (sa->SRB_HaId != 0) {
		return SS_INVALID_HA;
	}
	switch (sa->SRB_Cmd) {
		case SC_HA_INQUIRY: /* x00 */
			srbStatus = ha_inquiry((SRB_HAInquiry *) v);
			break;
		case SC_EXEC_SCSI_CMD: /* x02 */
			srbStatus = exec_scsi_cmd((SRB_ExecSCSICmd *) v);
			break;
		default:
			break;
	}
	sa->SRB_Status = srbStatus;
	return srbStatus;
}

/* end of file */