diskio.cpp

在delphi中实现windows核心编程.原书光盘代码核心编程.原书光盘代码

// DISKIO.cpp - main module for VxD DISKIO

#define DEVICE_MAIN
#include "diskio.h"

/*声明虚拟设备*/
Declare_Virtual_Device(DISKIO)
#undef DEVICE_MAIN

/*定义一个IOCTL控制码实现Win32应用程序与VXD交互*/
#define DIOC_MY1 CTL_CODE(FILE_DEVICE_UNKNOWN,1,METHOD_NEITHER,FILE_ANY_ACCESS)

#define MAXBUF 0x200

DiskioVM::DiskioVM(VMHANDLE hVM) : VVirtualMachine(hVM) {}

DiskioThread::DiskioThread(THREADHANDLE hThread) : VThread(hThread) {}
/*处理动态加载的VXD并作初始化，SYS_DYNAMIC_DEVICE_INIT*/
BOOL DiskioDevice::OnSysDynamicDeviceInit()
{
	return TRUE;
}

/*处理动态加载的VXD并从内存移去*/
BOOL DiskioDevice::OnSysDynamicDeviceExit()
{
	return TRUE;
}

/*定义输入缓冲区结构*/
struct TInBuffer {
    BOOL ReadOrNot;  //True:Read, False:Write
    int Disk;        //$80...
    unsigned int StartSecLo,StartSecHi;//开始扇区  结束扇区 
    unsigned int SecCount;//扇区数
};

/*有针对地传给指定的VXD响应Win32应用程序调用CreateFile或DeviceIoControl函数*/
DWORD DiskioDevice::OnW32DeviceIoControl(PIOCTLPARAMS pDIOCParams)
{
     switch (pDIOCParams->dioc_IOCtlCode)
     {
      case DIOC_MY1: /*如果为指定的控制消息*/
	    IOR *ior;
        char iorBuffer[0xfc]={0}; //0xfc=0xac+0x58  sizeof(IOR)=0x58
        struct TInBuffer *op;//输入缓冲区
	    char *buffer ;  //定义输入/输出缓冲区指针
        char data[MAXBUF]={0};

		/*输入缓冲区转换为指定结构形式*/
	    op = (struct TInBuffer *)pDIOCParams->dioc_InBuf;
		/*输出缓冲区*/
	    buffer = (char *)pDIOCParams->dioc_OutBuf;

  	    ior=(IOR *)(iorBuffer+0xac);
		/*=$80  硬盘*/
        ior->IOR_vol_designtr = op->Disk;			
        if (op->ReadOrNot)
			/*读由IOR_xfer_count的sectors/bytes*/
			ior->IOR_func = IOR_READ;
        else 
			/*写由IOR_xfer_count的sectors/bytes*/
			ior->IOR_func = IOR_WRITE;
		/*IORF_PHYS_CMD物理设备IO
		  IORF_VERSION_002 表明BCB使用扩展,IO格式请求
		  IORF_SYNC_COMMAND 表明同步命令
		  IORF_HIGH_PRIORITY 表明先优先级
		*/	  
        ior->IOR_flags = IORF_PHYS_CMD|IORF_VERSION_002|IORF_SYNC_COMMAND|IORF_HIGH_PRIORITY;
		/*块设备BlockDev客户缓冲区指针*/
        ior->IOR_buffer_ptr = (ULONG)data;
		/*扇区数*/
        ior->IOR_xfer_count = 1;
        for(int i=0;i<op->SecCount;i++)
        {
          ior->IOR_start_addr[0] = op->StartSecLo+i;			
 	      ior->IOR_start_addr[1] = op->StartSecHi;			
          ior->IOR_next = 1;			
          if (!(op->ReadOrNot)) 
			  /*把buffer数据拷贝到data*/
			  memcpy(data,buffer,MAXBUF);
		  /*发送请求命令*/
  	      IOS_SendCommand(ior,NULL);
          if (ior->IOR_status!=0) break;
          if (op->ReadOrNot) 
			  /*读数据*/
			  memcpy(buffer,data,MAXBUF);
          buffer+=MAXBUF;
        }
        if (ior->IOR_status==0)
			*(pDIOCParams->dioc_bytesret)=op->SecCount*512;
        else 
			*(long*)(pDIOCParams->dioc_bytesret)=0;
        break;
     }
     return 0;
}