explorer/dll.c

   1
   2 #include "../common/cache.h"
   3
   4 #include <shlobj.h>
   5 #include <stdio.h>
   6 #include "dll.h"
   7 #include "../common/menuengine.h"
   8 #include "ext.h"
   9 #include "factory.h"
  10 #include "../common/systeminfo.h"
  11 #include "registry.h"
  12
  13 const char *program_name = "Git-Cheetah";
  14 const char *program_version = "Git-Cheetah.Application.1";
  15 const char *program_id = "Git-Cheetah.Application";
  16
  17 /*
  18  * The following is just the necessary infrastructure for having a .dll
  19  * which can be registered as a COM object.
  20  */
  21 HINSTANCE hInst;
  22
  23 HRESULT STDAPICALLTYPE DllGetClassObject(REFCLSID obj_guid, REFIID factory_guid,
  24                 void **factory_handle)
  25 {
  26         if (IsEqualCLSID(obj_guid, &CLSID_git_shell_ext) ||
  27                         IsEqualCLSID(obj_guid, &CLSID_git_menu))
  28                 return class_factory_query_interface(&factory,
  29                                 factory_guid, factory_handle);
  30
  31         *factory_handle = 0;
  32         return CLASS_E_CLASSNOTAVAILABLE;
  33 }
  34
  35 HRESULT STDAPICALLTYPE DllCanUnloadNow(void)
  36 {
  37    return (object_count || lock_count) ? S_FALSE : S_OK;
  38 }
  39
  40 BOOL WINAPI DllMain(HINSTANCE instance, DWORD reason, LPVOID reserved)
  41 {
  42         hInst = instance;
  43
  44         if (reason == DLL_PROCESS_ATTACH) {
  45                 object_count = lock_count = 0;
  46                 DisableThreadLibraryCalls(instance);
  47         }
  48
  49         return 1;
  50 }
  51
  52 /* replaces a substring pattern with a string replacement within a string
  53    the replacement occurs in-place, hence string must be large enough to
  54    hold the result
  55
  56    the function does not handle recursive replacements, e.g.
  57      strreplace ("foo", "bar", "another bar");
  58
  59    always returns *string
  60 */
  61 static char *strreplace(char *string, const size_t size,
  62                         const char *pattern, const char *replacement)
  63 {
  64         size_t len = strlen(string);
  65         const size_t pattern_len = strlen(pattern);
  66         const size_t replace_len = strlen(replacement);
  67
  68         char *found = strstr(string, pattern);
  69
  70         while (found) {
  71                 /* if the new len is greater than size, bail out */
  72                 if (len + replace_len - pattern_len >= size)
  73                         return string;
  74
  75                 if (pattern_len != replace_len)
  76                         memmove(found + replace_len,
  77                                 found + pattern_len,
  78                                 len - (found - string) - pattern_len + 1);
  79                 memcpy(found, replacement, replace_len);
  80                 len += replace_len - pattern_len;
  81
  82                 found = strstr(string, pattern);
  83         }
  84
  85         return string;
  86 }
  87
  88 /*
  89  * The following is the data for our minimal regedit engine,
  90  * required for registration/unregistration of the extension
  91  */
  92 #define CLASS_CHEETAH CLASSES_ROOT "CLSID\\@@CLSID@@"
  93 #define CONTEXTMENUHANDLER "shellex\\ContextMenuHandlers\\@@PROGRAM_NAME@@"
  94 #define COLUMNHANDLER "shellex\\ColumnHandlers"
  95
  96 static const char *get_module_filename() {
  97         static char module_filename[MAX_PATH] = { '\0' };
  98
  99         if (!*module_filename) {
 100                 DWORD module_size;
 101
 102                 module_size = GetModuleFileName(hInst,
 103                                 module_filename, MAX_PATH);
 104                 if (0 == module_size)
 105                         return NULL;
 106         }
 107
 108         return module_filename;
 109 }
 110
 111 /* as per "How to: Convert Between System::Guid and _GUID" */
 112 static const char *get_class_id()
 113 {
 114         static char class_id[MAX_REGISTRY_PATH] = { '\0' };
 115
 116         if (!*class_id) {
 117                 GUID guid = CLSID_git_shell_ext;
 118                 sprintf(class_id,
 119                         "{%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x}",
 120                         guid.Data1, guid.Data2, guid.Data3,
 121                         guid.Data4[0], guid.Data4[1], guid.Data4[2],
 122                         guid.Data4[3], guid.Data4[4], guid.Data4[5],
 123                         guid.Data4[6], guid.Data4[7]);
 124         }
 125
 126         return class_id;
 127 }
 128
 129 /*
 130  * Tries to find msysGit in the following order:
 131  * .. and ../.. (relative to the module)
 132  * %PATH%
 133  * as qgit (via InstallLocation of Git)
 134  SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Git_is1\InstallLocation
 135  */
 136 static const reg_value registry_info[] = {
 137         { CURRENT_WINDOWS APPROVED_EXT, "@@CLSID@@", "@@PROGRAM_NAME@@" },
 138         { CURRENT_WINDOWS APPROVED_EXT "\\@@CLSID@@",
 139                 NULL, NULL },
 140         { CURRENT_WINDOWS APPROVED_EXT "\\@@CLSID@@",
 141                 NULL,"@@PROGRAM_NAME@@" },
 142         { CLASS_CHEETAH, NULL, NULL },
 143         { CLASS_CHEETAH, NULL, "@@PROGRAM_NAME@@" },
 144         { CLASS_CHEETAH "\\InProcServer32", NULL, NULL },
 145         { CLASS_CHEETAH "\\InProcServer32", NULL, "@@PROGRAM_PATH@@"},
 146         { CLASS_CHEETAH "\\InProcServer32", "ThreadingModel", "Apartment" },
 147         { CLASSES_ROOT "*\\" CONTEXTMENUHANDLER, NULL, NULL },
 148         { CLASSES_ROOT "*\\" CONTEXTMENUHANDLER, NULL, "@@CLSID@@" },
 149         { CLASSES_ROOT "Directory\\" CONTEXTMENUHANDLER, NULL, NULL },
 150         { CLASSES_ROOT "Directory\\" CONTEXTMENUHANDLER, NULL, "@@CLSID@@" },
 151         { CLASSES_ROOT "Directory\\Background\\" CONTEXTMENUHANDLER,
 152                 NULL, NULL },
 153         { CLASSES_ROOT "Directory\\Background\\" CONTEXTMENUHANDLER,
 154                 NULL, "@@CLSID@@" },
 155         { CLASSES_ROOT "Drive\\" CONTEXTMENUHANDLER, NULL, NULL },
 156         { CLASSES_ROOT "Drive\\" CONTEXTMENUHANDLER, NULL, "@@CLSID@@"},
 157         { CLASSES_ROOT "Folder\\" CONTEXTMENUHANDLER, NULL, NULL },
 158         { CLASSES_ROOT "Folder\\" CONTEXTMENUHANDLER, NULL, "@@CLSID@@" },
 159         { CLASSES_ROOT "Folder\\" COLUMNHANDLER "\\@@CLSID@@", NULL, NULL },
 160         { CLASSES_ROOT "InternetShortcut\\" CONTEXTMENUHANDLER,
 161                 NULL, NULL },
 162         { CLASSES_ROOT "InternetShortcut\\" CONTEXTMENUHANDLER,
 163                 NULL, "@@CLSID@@" },
 164         { GIT_CHEETAH_REG_PATH, NULL, NULL },
 165         { GIT_CHEETAH_REG_PATH,
 166                 GIT_CHEETAH_REG_PATHTOMSYS, "@@MSYSGIT_PATH@@" },
 167         { NULL, NULL, NULL }
 168 };
 169
 170 static const reg_value debug_info[] = {
 171         { CURRENT_WINDOWS "Explorer", "DesktopProcess", "1" },
 172         { CURRENT_WINDOWS "Explorer\\AlwaysUnloadDll", NULL, NULL },
 173         { CURRENT_WINDOWS "Explorer\\Advanced", "SeparateProcess", "1" },
 174         { NULL, NULL, NULL }
 175 };
 176
 177 static char msysgit[MAX_PATH] = { '\0' };
 178
 179 static BOOL find_msysgit_in_path()
 180 {
 181         char *file; /* file part of the path to git.exe */
 182         DWORD dwFound; /* length of path to git.exe */
 183
 184         dwFound = SearchPath(NULL, "git.exe", NULL, MAX_PATH, msysgit, &file);
 185         /* if git is not in the PATH or its path is too long */
 186         if (0 == dwFound ||
 187                 dwFound > MAX_PATH)
 188                 return FALSE;
 189
 190         /*
 191          * git.exe is in "\bin\" from what we really need
 192          * the minimal case we can handle is c:\bin\git.exe
 193          * otherwise declare failure. We additionally check
 194          * for Git for Windows where it is placed in ..\Git\cmd\
 195          */
 196         if (file < msysgit + 7)
 197                 return FALSE;
 198         if (strnicmp(file - 5, "\\bin\\", 5) && strnicmp(file - 5, "\\cmd\\", 5))
 199                 return FALSE;
 200         file[-5] = '\0';
 201
 202         return TRUE;
 203 }
 204
 205 static BOOL find_msysgit_relative(const char *path)
 206 {
 207         char *c;
 208
 209         strcpy(msysgit, get_module_filename());
 210         c = strrchr(msysgit, '\\');
 211         c[1] = '\0';
 212         strcat(msysgit, path);
 213         strcat(msysgit, "\\bin\\git.exe");
 214         if (INVALID_FILE_ATTRIBUTES == GetFileAttributes(msysgit)) {
 215                 msysgit[0] = '\0'; /* restore the original result */
 216                 return FALSE;
 217         }
 218
 219         c[1] = '\0';
 220         strcat(msysgit, path);
 221         return TRUE;
 222 }
 223
 224 static BOOL find_msysgit_uninstall(HKEY root)
 225 {
 226         HKEY key;
 227         HRESULT result;
 228         DWORD valuelen = MAX_PATH;
 229
 230         result = RegOpenKeyEx(root,
 231                         CURRENT_WINDOWS "\\Uninstall\\Git_is1",
 232                         0, KEY_READ, &key);
 233         if (ERROR_SUCCESS != result)
 234                 return FALSE;
 235
 236         result = RegQueryValue(key, "InstallLocation",
 237                         (LPBYTE)msysgit, &valuelen);
 238         return ERROR_SUCCESS == result;
 239 }
 240
 241 static HKEY setup_root;
 242
 243 static const char *find_msysgit()
 244 {
 245         if ('\0' == msysgit[0]) {
 246                 if (find_msysgit_relative(".."))
 247                         return msysgit;
 248
 249                 if (find_msysgit_relative("..\\.."))
 250                         return msysgit;
 251
 252                 if (find_msysgit_in_path())
 253                         return msysgit;
 254
 255                 if (setup_root)
 256                         find_msysgit_uninstall(setup_root);
 257         }
 258
 259         return msysgit;
 260 }
 261
 262 /*
 263  * required by registry.c
 264  * supports @@PROGRAM_NAME@@, @@PROGRAM_PATH@@, @@CLSID@@ patterns
 265  */
 266 char *get_registry_path(const char *src, char dst[MAX_REGISTRY_PATH])
 267 {
 268         if (NULL == src)
 269                 return NULL;
 270
 271         strcpy(dst, src);
 272         strreplace(dst, MAX_REGISTRY_PATH,
 273                         "@@PROGRAM_NAME@@", program_name);
 274         strreplace(dst, MAX_REGISTRY_PATH,
 275                         "@@PROGRAM_PATH@@", get_module_filename());
 276         strreplace(dst, MAX_REGISTRY_PATH,
 277                         "@@CLSID@@", get_class_id());
 278         strreplace(dst, MAX_REGISTRY_PATH,
 279                         "@@MSYSGIT_PATH@@", find_msysgit());
 280
 281         return dst;
 282 }
 283
 284 HRESULT PASCAL DllRegisterServer(void)
 285 {
 286         HRESULT retval;
 287         setup_root = HKEY_CURRENT_USER;
 288         retval = create_reg_entries (setup_root, registry_info);
 289         SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST,NULL,NULL);
 290         return retval;
 291 }
 292
 293 HRESULT PASCAL DllUnregisterServer(void)
 294 {
 295         HRESULT retval;
 296         setup_root = HKEY_CURRENT_USER;
 297         retval = delete_reg_entries(setup_root, registry_info);
 298         SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST,NULL,NULL);
 299         return retval;
 300 }
 301
 302 /* provide means to create/delete keys:
 303    - described in Debugging with The Shell;
 304    - machine-wide registration and debugging info
 305
 306    possible combinations of regsvr32 command line options:
 307              -n  (absent)               (present)
 308    -i:
 309    (absent)      user reg               (invalid)
 310    debug         user reg+debug         user debug
 311    machine       user+machine reg       machine reg
 312    machinedebug  user+machine reg+debug machine reg+debug
 313
 314    Obviously missing option is "machine debug". To accomplish:
 315    - execute "regsvr32 -n -i:machinedebug" and then
 316    - regsvr32 -u -n -i:machine
 317 */
 318 HRESULT PASCAL DllInstall(BOOL bInstall, LPCWSTR pszCmdLine)
 319 {
 320         BOOL bDebug = NULL != wcsstr(pszCmdLine, L"debug");
 321         HRESULT result = ERROR_SUCCESS;
 322
 323         setup_root = wcsstr(pszCmdLine, L"machine") ?
 324                         HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
 325
 326         if (bInstall) {
 327                 if (bDebug)
 328                         result = create_reg_entries(setup_root, debug_info);
 329
 330                 /* for user-only registration, use DllRegister */
 331                 if (ERROR_SUCCESS == result &&
 332                     HKEY_LOCAL_MACHINE == setup_root)
 333                         result = create_reg_entries(setup_root,
 334                                         registry_info);
 335         } else { /* uninstall */
 336                 if (bDebug)
 337                         result = delete_reg_entries(setup_root, debug_info);
 338
 339                 /* for user-only unregistration, use DllUnregister */
 340                 if (ERROR_SUCCESS == result &&
 341                     HKEY_LOCAL_MACHINE == setup_root)
 342                         result = delete_reg_entries(setup_root,
 343                                         registry_info);
 344         }
 345         SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST,NULL,NULL);
 346         return result;
 347 }