PROBE.C

/******************************************************************************\ 
*       This is a part of the Microsoft Source Code Samples.  
*       Copyright 1993 - 1998 Microsoft Corporation. 
*       All rights reserved.  
*       This source code is only intended as a supplement to  
*       Microsoft Development Tools and/or WinHelp documentation. 
*       See these sources for detailed information regarding the  
*       Microsoft samples programs. 
\******************************************************************************/ 
 
#include "pwalk.h" 
 
 
/* process  globals */ 
HANDLE    hMMFile = 0; 
LPPROBE     lpProbe = NULL; 
CONTEXT     gContext; 
DWORD    gReturn; 
LPVOID    gLocation; 
CRITICAL_SECTION    gCS; 
 
 
BOOL   WINAPI ProbeProcess (HANDLE); 
void   WINAPI FreeProbe (); 
void   WINAPI GetFuncAddrInChildProc (char *, char *, DBGDLL *, LPVOID *); 
 
 
/* entry point for DLL loading and unloading */ 
BOOL WINAPI DllMain ( 
    HANDLE    hModule, 
    DWORD     dwFunction, 
    LPVOID    lpNot) 
{ 
    switch (dwFunction) 
{ 
case DLL_PROCESS_ATTACH: 
    ProbeProcess (hModule); 
    break; 
 
case DLL_PROCESS_DETACH: 
    FreeProbe (); 
    break; 
 
default: 
    break; 
} 
 
    return TRUE; 
} 
 
 
 
/* function initializes port structures */ 
BOOL WINAPI ProbeProcess ( 
    HANDLE    hDLL) 
{ 
    charszMapFileName[MAX_PATH]; 
 
    /* load name for global file mapping */ 
    LoadString (hDLL, IDS_MAPFILENAME, szMapFileName, MAX_PATH); 
 
    /* ProcessWalker creates file mapping then child process attaches */ 
    if ((hMMFile = OpenFileMapping (FILE_MAP_WRITE, FALSE, szMapFileName))) 
{ 
/* map global view of file for hook function access */ 
lpProbe = (LPPROBE)MapViewOfFile (hMMFile, FILE_MAP_WRITE, 0, 0, 0); 
 
/* initialize known process specific information in probe */ 
lpProbe->hProcess = GetCurrentProcess (); 
lpProbe->hDefHeap = GetProcessHeap (); 
} 
 
    else 
if (!(hMMFile = CreateFileMapping ((HANDLE)0xffffffff, 
   NULL, 
   PAGE_READWRITE, 
   0, 
   0x100000, 
   szMapFileName))) 
    return FALSE; 
else 
    { 
    lpProbe = (LPPROBE)MapViewOfFile (hMMFile, FILE_MAP_WRITE, 0, 0, 0); 
    ResetProbe (); 
    } 
 
    /* success */ 
    return TRUE; 
} 
 
 
 
 
/* release process objects */ 
void WINAPI FreeProbe () 
{ 
    if (lpProbe != NULL) 
/* remove child process objects */ 
UnmapViewOfFile ((char *)lpProbe); 
 
    CloseHandle (hMMFile); 
} 
 
 
 
 
/* function passes pointer to probe info back to ProcessWalker */ 
LPPROBE  WINAPI RetrieveProbeData () 
{ 
    return lpProbe; 
} 
 
 
 
 
/* reset probe data to null */ 
void  WINAPI ResetProbe () 
{ 
    lpProbe->hProcess = NULL; 
    lpProbe->hDefHeap = NULL; 
}