hook example

/****************************************************************************** Module: DIPSLib.cpp Notices: Copyright (c) 2000 Jeffrey Richter ******************************************************************************/ #include "..\CmnHdr.h" /* See Appendix A. */ #include <WindowsX.h> #include <CommCtrl.h> #define DIPSLIBAPI __declspec(dllexport) #include "DIPSLib.h" #include "Resource.h" /////////////////////////////////////////////////////////////////////////////// #ifdef _DEBUG // This function forces the debugger to be invoked void ForceDebugBreak() { __try { DebugBreak(); } __except(UnhandledExceptionFilter(GetExceptionInformation())) { } } #else #define ForceDebugBreak() #endif /////////////////////////////////////////////////////////////////////////////// // Forward references LRESULT WINAPI GetMsgProc(int nCode, WPARAM wParam, LPARAM lParam); INT_PTR WINAPI Dlg_Proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam); /////////////////////////////////////////////////////////////////////////////// // Instruct the compiler to put the g_hhook data variable in // its own data section called Shared. We then instruct the // linker that we want to share the data in this section // with all instances of this application. #pragma data_seg("Shared") HHOOK g_hhook = NULL; DWORD g_dwThreadIdDIPS = 0; #pragma data_seg() // Instruct the linker to make the Shared section // readable, writable, and shared. #pragma comment(linker, "/section:Shared,rws") /////////////////////////////////////////////////////////////////////////////// // Nonshared variables HINSTANCE g_hinstDll = NULL; /////////////////////////////////////////////////////////////////////////////// BOOL WINAPI DllMain(HINSTANCE hinstDll, DWORD fdwReason, PVOID fImpLoad) { switch (fdwReason) { case DLL_PROCESS_ATTACH: // DLL is attaching to the address space of the current process. g_hinstDll = hinstDll; break; case DLL_THREAD_ATTACH: // A new thread is being created in the current process. break; case DLL_THREAD_DETACH: // A thread is exiting cleanly. break; case DLL_PROCESS_DETACH: // The calling process is detaching the DLL from its address space. break; } return(TRUE); } /////////////////////////////////////////////////////////////////////////////// BOOL WINAPI SetDIPSHook(DWORD dwThreadId) { BOOL fOk = FALSE; if (dwThreadId != 0) { // Make sure that the hook is not already installed. chASSERT(g_hhook == NULL); // Save our thread ID in a shared variable so that our GetMsgProc // function can post a message back to to thread when the server // window has been created. g_dwThreadIdDIPS = GetCurrentThreadId(); // Install the hook on the specified thread g_hhook = SetWindowsHookEx(WH_GETMESSAGE, GetMsgProc, g_hinstDll, dwThreadId); fOk = (g_hhook != NULL); if (fOk) { // The hook was installed successfully; force a benign message to // the thread's queue so that the hook function gets called. fOk = PostThreadMessage(dwThreadId, WM_NULL, 0, 0); } } else { // Make sure that a hook has been installed. chASSERT(g_hhook != NULL); fOk = UnhookWindowsHookEx(g_hhook); g_hhook = NULL; } return(fOk); } /////////////////////////////////////////////////////////////////////////////// LRESULT WINAPI GetMsgProc(int nCode, WPARAM wParam, LPARAM lParam) { static BOOL fFirstTime = TRUE; if (fFirstTime) { // The DLL just got injected. fFirstTime = FALSE; // Uncomment the line below to invoke the debugger // on the process that just got the injected DLL. // ForceDebugBreak(); // Create the DTIS Server window to handle the client request. CreateDialog(g_hinstDll, MAKEINTRESOURCE(IDD_DIPS), NULL, Dlg_Proc); // Tell the DIPS application that the server is up // and ready to handle requests. PostThreadMessage(g_dwThreadIdDIPS, WM_NULL, 0, 0); } return(CallNextHookEx(g_hhook, nCode, wParam, lParam)); } /////////////////////////////////////////////////////////////////////////////// void Dlg_OnClose(HWND hwnd) { DestroyWindow(hwnd); } /////////////////////////////////////////////////////////////////////////////// static const TCHAR g_szRegSubKey[] = TEXT("Software\\Richter\\Desktop Item Position Saver"); /////////////////////////////////////////////////////////////////////////////// void SaveListViewItemPositions(HWND hwndLV) { int nMaxItems = ListView_GetItemCount(hwndLV); // When saving new positions, delete the old position // information that is currently in the registry. LONG l = RegDeleteKey(HKEY_CURRENT_USER, g_szRegSubKey); // Create the registry key to hold the info HKEY hkey; l = RegCreateKeyEx(HKEY_CURRENT_USER, g_szRegSubKey, 0, NULL, REG_OPTION_NON_VOLATILE, KEY_SET_VALUE, NULL, &hkey, NULL); chASSERT(l == ERROR_SUCCESS); for (int nItem = 0; nItem < nMaxItems; nItem++) { // Get the name and position of a ListView item. TCHAR szName[MAX_PATH]; ListView_GetItemText(hwndLV, nItem, 0, szName, chDIMOF(szName)); POINT pt; ListView_GetItemPosition(hwndLV, nItem, &pt); // Save the name and position in the registry. l = RegSetValueEx(hkey, szName, 0, REG_BINARY, (PBYTE) &pt, sizeof(pt)); chASSERT(l == ERROR_SUCCESS); } RegCloseKey(hkey); } /////////////////////////////////////////////////////////////////////////////// void RestoreListViewItemPositions(HWND hwndLV) { HKEY hkey; LONG l = RegOpenKeyEx(HKEY_CURRENT_USER, g_szRegSubKey, 0, KEY_QUERY_VALUE, &hkey); if (l == ERROR_SUCCESS) { // If the ListView has AutoArrange on, temporarily turn it off. DWORD dwStyle = GetWindowStyle(hwndLV); if (dwStyle & LVS_AUTOARRANGE) SetWindowLong(hwndLV, GWL_STYLE, dwStyle & ~LVS_AUTOARRANGE); l = NO_ERROR; for (int nIndex = 0; l != ERROR_NO_MORE_ITEMS; nIndex++) { TCHAR szName[MAX_PATH]; DWORD cbValueName = chDIMOF(szName); POINT pt; DWORD cbData = sizeof(pt), nItem; // Read a value name and position from the registry. DWORD dwType; l = RegEnumValue(hkey, nIndex, szName, &cbValueName, NULL, &dwType, (PBYTE) &pt, &cbData); if (l == ERROR_NO_MORE_ITEMS) continue; if ((dwType == REG_BINARY) && (cbData == sizeof(pt))) { // The value is something that we recognize; try to find // an item in the ListView control that matches the name. LV_FINDINFO lvfi; lvfi.flags = LVFI_STRING; lvfi.psz = szName; nItem = ListView_FindItem(hwndLV, -1, &lvfi); if (nItem != -1) { // We found a match; change the item's position. ListView_SetItemPosition(hwndLV, nItem, pt.x, pt.y); } } } // Turn AutoArrange back on if it was originally on. SetWindowLong(hwndLV, GWL_STYLE, dwStyle); RegCloseKey(hkey); } } /////////////////////////////////////////////////////////////////////////////// INT_PTR WINAPI Dlg_Proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) { switch (uMsg) { chHANDLE_DLGMSG(hwnd, WM_CLOSE, Dlg_OnClose); case WM_APP: // Uncomment the line below to invoke the debugger // on the process that just got the injected DLL. // ForceDebugBreak(); if (lParam) SaveListViewItemPo