extern "C"
{

#include <wdm.h>
#include "func.h"
#include "debug.h"

int func_is_good_read_ptr(PVOID buf,ULONG size);
} //extern "C"

/*
 this function checks user buffer for read access 
 returns true if the buffer is ok
*/

int func_is_good_read_ptr(PVOID buf,ULONG size)
{
  DbgMsg("func.cpp: func_is_good_read_ptr(buf:0x%.8X;size:0x%.8X)",buf,size);

  int res=TRUE;

  __try
  {
    ProbeForRead(buf,size,sizeof(char));
    ULONG sum=0;
    PULONG p=(PULONG)buf;
    int i;
    for (i=0;i<(int)(size/sizeof(ULONG));i++) sum+=p[i];
    for (int j=0;j<(int)(size%sizeof(ULONG));j++) sum+=*((UCHAR*)&p[i]+j);
  } __except(EXCEPTION_EXECUTE_HANDLER)
  {
    DbgPrint("func.cpp: func_is_good_read_ptr error: exception occurred");
    res=FALSE;
  }

  DbgMsg("func.cpp: func_is_good_read_ptr(-):%d",res);
  return res;
}