glib/gspawn-win32-helper.c

   1 /* gspawn-win32-helper.c - Helper program for process launching on Win32.
   2  *
   3  *  Copyright 2000 Red Hat, Inc.
   4  *  Copyright 2000 Tor Lillqvist
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "config.h"
  21
  22 #include <fcntl.h>
  23
  24 /* For _CrtSetReportMode, we don't want Windows CRT (2005 and later)
  25  * to terminate the process if a bad file descriptor is passed into
  26  * _get_osfhandle().  This is necessary because we use _get_osfhandle()
  27  * to check the validity of the fd before we try to call close() on
  28  * it as attempting to close an invalid fd will cause the Windows CRT
  29  * to abort() this program internally.
  30  *
  31  * Please see http://msdn.microsoft.com/zh-tw/library/ks2530z6%28v=vs.80%29.aspx
  32  * for an explanation on this.
  33  */
  34 #if (defined (_MSC_VER) && _MSC_VER >= 1400)
  35 #include <crtdbg.h>
  36 #endif
  37
  38 #undef G_LOG_DOMAIN
  39 #include "glib.h"
  40 #define GSPAWN_HELPER
  41 #include "gspawn-win32.c"       /* For shared definitions */
  42
  43
  44 static void
  45 write_err_and_exit (gint    fd,
  46                     gintptr msg)
  47 {
  48   gintptr en = errno;
  49
  50   write (fd, &msg, sizeof(gintptr));
  51   write (fd, &en, sizeof(gintptr));
  52
  53   _exit (1);
  54 }
  55
  56 #ifdef __GNUC__
  57 #  ifndef _stdcall
  58 #    define _stdcall  __attribute__((stdcall))
  59 #  endif
  60 #endif
  61
  62 /* We build gspawn-win32-helper.exe as a Windows GUI application
  63  * to avoid any temporarily flashing console windows in case
  64  * the gspawn function is invoked by a GUI program. Thus, no main()
  65  * but a WinMain().
  66  */
  67
  68 /* Copy of protect_argv that handles wchar_t strings */
  69
  70 static gint
  71 protect_wargv (gint       argc,
  72                wchar_t  **wargv,
  73                wchar_t ***new_wargv)
  74 {
  75   gint i;
  76
  77   *new_wargv = g_new (wchar_t *, argc+1);
  78
  79   /* Quote each argv element if necessary, so that it will get
  80    * reconstructed correctly in the C runtime startup code.  Note that
  81    * the unquoting algorithm in the C runtime is really weird, and
  82    * rather different than what Unix shells do. See stdargv.c in the C
  83    * runtime sources (in the Platform SDK, in src/crt).
  84    *
  85    * Note that an new_wargv[0] constructed by this function should
  86    * *not* be passed as the filename argument to a _wspawn* or _wexec*
  87    * family function. That argument should be the real file name
  88    * without any quoting.
  89    */
  90   for (i = 0; i < argc; i++)
  91     {
  92       wchar_t *p = wargv[i];
  93       wchar_t *q;
  94       gint len = 0;
  95       gboolean need_dblquotes = FALSE;
  96       while (*p)
  97         {
  98           if (*p == ' ' || *p == '\t')
  99             need_dblquotes = TRUE;
 100           else if (*p == '"')
 101             len++;
 102           else if (*p == '\\')
 103             {
 104               wchar_t *pp = p;
 105               while (*pp && *pp == '\\')
 106                 pp++;
 107               if (*pp == '"')
 108                 len++;
 109             }
 110           len++;
 111           p++;
 112         }
 113
 114       q = (*new_wargv)[i] = g_new (wchar_t, len + need_dblquotes*2 + 1);
 115       p = wargv[i];
 116
 117       if (need_dblquotes)
 118         *q++ = '"';
 119
 120       while (*p)
 121         {
 122           if (*p == '"')
 123             *q++ = '\\';
 124           else if (*p == '\\')
 125             {
 126               wchar_t *pp = p;
 127               while (*pp && *pp == '\\')
 128                 pp++;
 129               if (*pp == '"')
 130                 *q++ = '\\';
 131             }
 132           *q++ = *p;
 133           p++;
 134         }
 135
 136       if (need_dblquotes)
 137         *q++ = '"';
 138       *q++ = '\0';
 139     }
 140   (*new_wargv)[argc] = NULL;
 141
 142   return argc;
 143 }
 144
 145 #if (defined (_MSC_VER) && _MSC_VER >= 1400)
 146 /*
 147  * This is the (empty) invalid parameter handler
 148  * that is used for Visual C++ 2005 (and later) builds
 149  * so that we can use this instead of the system automatically
 150  * aborting the process.
 151  *
 152  * This is necessary as we use _get_oshandle() to check the validity
 153  * of the file descriptors as we close them, so when an invalid file
 154  * descriptor is passed into that function as we check on it, we get
 155  * -1 as the result, instead of the gspawn helper program aborting.
 156  *
 157  * Please see http://msdn.microsoft.com/zh-tw/library/ks2530z6%28v=vs.80%29.aspx
 158  * for an explanation on this.
 159  */
 160 extern void
 161 myInvalidParameterHandler(const wchar_t *expression,
 162                           const wchar_t *function,
 163                           const wchar_t *file,
 164                           unsigned int   line,
 165                           uintptr_t      pReserved);
 166 #endif
 167
 168
 169 #ifndef HELPER_CONSOLE
 170 int _stdcall
 171 WinMain (struct HINSTANCE__ *hInstance,
 172          struct HINSTANCE__ *hPrevInstance,
 173          char               *lpszCmdLine,
 174          int                 nCmdShow)
 175 #else
 176 int
 177 main (int ignored_argc, char **ignored_argv)
 178 #endif
 179 {
 180   int child_err_report_fd = -1;
 181   int helper_sync_fd = -1;
 182   int i;
 183   int fd;
 184   int mode;
 185   gintptr handle;
 186   int saved_errno;
 187   gintptr no_error = CHILD_NO_ERROR;
 188   gint argv_zero_offset = ARG_PROGRAM;
 189   wchar_t **new_wargv;
 190   int argc;
 191   char **argv;
 192   wchar_t **wargv;
 193   char c;
 194
 195 #if (defined (_MSC_VER) && _MSC_VER >= 1400)
 196   /* set up our empty invalid parameter handler */
 197   _invalid_parameter_handler oldHandler, newHandler;
 198   newHandler = myInvalidParameterHandler;
 199   oldHandler = _set_invalid_parameter_handler(newHandler);
 200
 201   /* Disable the message box for assertions. */
 202   _CrtSetReportMode(_CRT_ASSERT, 0);
 203 #endif
 204
 205   /* Fetch the wide-char argument vector */
 206   wargv = CommandLineToArgvW (GetCommandLineW(), &argc);
 207
 208   g_assert (argc >= ARG_COUNT);
 209
 210   /* Convert unicode wargs to utf8 */
 211   argv = g_new(char *, argc + 1);
 212   for (i = 0; i < argc; i++)
 213     argv[i] = g_utf16_to_utf8(wargv[i], -1, NULL, NULL, NULL);
 214   argv[i] = NULL;
 215
 216   /* argv[ARG_CHILD_ERR_REPORT] is the file descriptor number onto
 217    * which write error messages.
 218    */
 219   child_err_report_fd = atoi (argv[ARG_CHILD_ERR_REPORT]);
 220
 221   /* Hack to implement G_SPAWN_FILE_AND_ARGV_ZERO. If
 222    * argv[ARG_CHILD_ERR_REPORT] is suffixed with a '#' it means we get
 223    * the program to run and its argv[0] separately.
 224    */
 225   if (argv[ARG_CHILD_ERR_REPORT][strlen (argv[ARG_CHILD_ERR_REPORT]) - 1] == '#')
 226     argv_zero_offset++;
 227
 228   /* argv[ARG_HELPER_SYNC] is the file descriptor number we read a
 229    * byte that tells us it is OK to exit. We have to wait until the
 230    * parent allows us to exit, so that the parent has had time to
 231    * duplicate the process handle we sent it. Duplicating a handle
 232    * from another process works only if that other process exists.
 233    */
 234   helper_sync_fd = atoi (argv[ARG_HELPER_SYNC]);
 235
 236   /* argv[ARG_STDIN..ARG_STDERR] are the file descriptor numbers that
 237    * should be dup2'd to 0, 1 and 2. '-' if the corresponding fd
 238    * should be left alone, and 'z' if it should be connected to the
 239    * bit bucket NUL:.
 240    */
 241   if (argv[ARG_STDIN][0] == '-')
 242     ; /* Nothing */
 243   else if (argv[ARG_STDIN][0] == 'z')
 244     {
 245       fd = open ("NUL:", O_RDONLY);
 246       if (fd != 0)
 247         {
 248           dup2 (fd, 0);
 249           close (fd);
 250         }
 251     }
 252   else
 253     {
 254       fd = atoi (argv[ARG_STDIN]);
 255       if (fd != 0)
 256         {
 257           dup2 (fd, 0);
 258           close (fd);
 259         }
 260     }
 261
 262   if (argv[ARG_STDOUT][0] == '-')
 263     ; /* Nothing */
 264   else if (argv[ARG_STDOUT][0] == 'z')
 265     {
 266       fd = open ("NUL:", O_WRONLY);
 267       if (fd != 1)
 268         {
 269           dup2 (fd, 1);
 270           close (fd);
 271         }
 272     }
 273   else
 274     {
 275       fd = atoi (argv[ARG_STDOUT]);
 276       if (fd != 1)
 277         {
 278           dup2 (fd, 1);
 279           close (fd);
 280         }
 281     }
 282
 283   if (argv[ARG_STDERR][0] == '-')
 284     ; /* Nothing */
 285   else if (argv[ARG_STDERR][0] == 'z')
 286     {
 287       fd = open ("NUL:", O_WRONLY);
 288       if (fd != 2)
 289         {
 290           dup2 (fd, 2);
 291           close (fd);
 292         }
 293     }
 294   else
 295     {
 296       fd = atoi (argv[ARG_STDERR]);
 297       if (fd != 2)
 298         {
 299           dup2 (fd, 2);
 300           close (fd);
 301         }
 302     }
 303
 304   /* argv[ARG_WORKING_DIRECTORY] is the directory in which to run the
 305    * process.  If "-", don't change directory.
 306    */
 307   if (argv[ARG_WORKING_DIRECTORY][0] == '-' &&
 308       argv[ARG_WORKING_DIRECTORY][1] == 0)
 309     ; /* Nothing */
 310   else if (_wchdir (wargv[ARG_WORKING_DIRECTORY]) < 0)
 311     write_err_and_exit (child_err_report_fd, CHILD_CHDIR_FAILED);
 312
 313   /* argv[ARG_CLOSE_DESCRIPTORS] is "y" if file descriptors from 3
 314    *  upwards should be closed
 315    */
 316   if (argv[ARG_CLOSE_DESCRIPTORS][0] == 'y')
 317     for (i = 3; i < 1000; i++)  /* FIXME real limit? */
 318       if (i != child_err_report_fd && i != helper_sync_fd)
 319         if (_get_osfhandle (i) != -1)
 320           close (i);
 321
 322   /* We don't want our child to inherit the error report and
 323    * helper sync fds.
 324    */
 325   child_err_report_fd = dup_noninherited (child_err_report_fd, _O_WRONLY);
 326   helper_sync_fd = dup_noninherited (helper_sync_fd, _O_RDONLY);
 327
 328   /* argv[ARG_WAIT] is "w" to wait for the program to exit */
 329   if (argv[ARG_WAIT][0] == 'w')
 330     mode = P_WAIT;
 331   else
 332     mode = P_NOWAIT;
 333
 334   /* argv[ARG_USE_PATH] is "y" to use PATH, otherwise not */
 335
 336   /* argv[ARG_PROGRAM] is executable file to run,
 337    * argv[argv_zero_offset]... is its argv. argv_zero_offset equals
 338    * ARG_PROGRAM unless G_SPAWN_FILE_AND_ARGV_ZERO was used, in which
 339    * case we have a separate executable name and argv[0].
 340    */
 341
 342   /* For the program name passed to spawnv(), don't use the quoted
 343    * version.
 344    */
 345   protect_wargv (argc - argv_zero_offset, wargv + argv_zero_offset, &new_wargv);
 346
 347   if (argv[ARG_USE_PATH][0] == 'y')
 348     handle = _wspawnvp (mode, wargv[ARG_PROGRAM], (const wchar_t **) new_wargv);
 349   else
 350     handle = _wspawnv (mode, wargv[ARG_PROGRAM], (const wchar_t **) new_wargv);
 351
 352   saved_errno = errno;
 353
 354   if (handle == -1 && saved_errno != 0)
 355     write_err_and_exit (child_err_report_fd, CHILD_SPAWN_FAILED);
 356
 357   write (child_err_report_fd, &no_error, sizeof (no_error));
 358   write (child_err_report_fd, &handle, sizeof (handle));
 359
 360   read (helper_sync_fd, &c, 1);
 361
 362   LocalFree (wargv);
 363   g_strfreev (argv);
 364
 365   return 0;
 366 }