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  * GLib is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * GLib 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
  17  * License along with GLib; see the file COPYING.LIB.  If not, write
  18  * to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 02111-1307, USA.
  20  */
  21
  22 #include "config.h"
  23
  24 #include <fcntl.h>
  25
  26 #undef G_LOG_DOMAIN
  27 #include "glib.h"
  28 #define GSPAWN_HELPER
  29 #include "gspawn-win32.c"       /* For shared definitions */
  30
  31
  32 static void
  33 write_err_and_exit (gint    fd,
  34                     gintptr msg)
  35 {
  36   gintptr en = errno;
  37
  38   write (fd, &msg, sizeof(gintptr));
  39   write (fd, &en, sizeof(gintptr));
  40
  41   _exit (1);
  42 }
  43
  44 #ifdef __GNUC__
  45 #  ifndef _stdcall
  46 #    define _stdcall  __attribute__((stdcall))
  47 #  endif
  48 #endif
  49
  50 /* We build gspawn-win32-helper.exe as a Windows GUI application
  51  * to avoid any temporarily flashing console windows in case
  52  * the gspawn function is invoked by a GUI program. Thus, no main()
  53  * but a WinMain(). We do, however, still use argc and argv tucked
  54  * away in the global __argc and __argv by the C runtime startup code.
  55  */
  56
  57 /* Info peeked from mingw runtime's source code. __wgetmainargs() is a
  58  * function to get the program's argv in wide char format.
  59  */
  60
  61 typedef struct {
  62   int newmode;
  63 } _startupinfo;
  64
  65 extern void __wgetmainargs(int *argc,
  66                            wchar_t ***wargv,
  67                            wchar_t ***wenviron,
  68                            int expand_wildcards,
  69                            _startupinfo *startupinfo);
  70
  71 /* Copy of protect_argv that handles wchar_t strings */
  72
  73 static gint
  74 protect_wargv (wchar_t  **wargv,
  75                wchar_t ***new_wargv)
  76 {
  77   gint i;
  78   gint argc = 0;
  79
  80   while (wargv[argc])
  81     ++argc;
  82   *new_wargv = g_new (wchar_t *, argc+1);
  83
  84   /* Quote each argv element if necessary, so that it will get
  85    * reconstructed correctly in the C runtime startup code.  Note that
  86    * the unquoting algorithm in the C runtime is really weird, and
  87    * rather different than what Unix shells do. See stdargv.c in the C
  88    * runtime sources (in the Platform SDK, in src/crt).
  89    *
  90    * Note that an new_wargv[0] constructed by this function should
  91    * *not* be passed as the filename argument to a _wspawn* or _wexec*
  92    * family function. That argument should be the real file name
  93    * without any quoting.
  94    */
  95   for (i = 0; i < argc; i++)
  96     {
  97       wchar_t *p = wargv[i];
  98       wchar_t *q;
  99       gint len = 0;
 100       gboolean need_dblquotes = FALSE;
 101       while (*p)
 102         {
 103           if (*p == ' ' || *p == '\t')
 104             need_dblquotes = TRUE;
 105           else if (*p == '"')
 106             len++;
 107           else if (*p == '\\')
 108             {
 109               wchar_t *pp = p;
 110               while (*pp && *pp == '\\')
 111                 pp++;
 112               if (*pp == '"')
 113                 len++;
 114             }
 115           len++;
 116           p++;
 117         }
 118
 119       q = (*new_wargv)[i] = g_new (wchar_t, len + need_dblquotes*2 + 1);
 120       p = wargv[i];
 121
 122       if (need_dblquotes)
 123         *q++ = '"';
 124
 125       while (*p)
 126         {
 127           if (*p == '"')
 128             *q++ = '\\';
 129           else if (*p == '\\')
 130             {
 131               wchar_t *pp = p;
 132               while (*pp && *pp == '\\')
 133                 pp++;
 134               if (*pp == '"')
 135                 *q++ = '\\';
 136             }
 137           *q++ = *p;
 138           p++;
 139         }
 140
 141       if (need_dblquotes)
 142         *q++ = '"';
 143       *q++ = '\0';
 144     }
 145   (*new_wargv)[argc] = NULL;
 146
 147   return argc;
 148 }
 149
 150 #ifndef HELPER_CONSOLE
 151 int _stdcall
 152 WinMain (struct HINSTANCE__ *hInstance,
 153          struct HINSTANCE__ *hPrevInstance,
 154          char               *lpszCmdLine,
 155          int                 nCmdShow)
 156 #else
 157 int
 158 main (int ignored_argc, char **ignored_argv)
 159 #endif
 160 {
 161   int child_err_report_fd = -1;
 162   int helper_sync_fd = -1;
 163   int i;
 164   int fd;
 165   int mode;
 166   gintptr handle;
 167   int saved_errno;
 168   gintptr no_error = CHILD_NO_ERROR;
 169   gint argv_zero_offset = ARG_PROGRAM;
 170   wchar_t **new_wargv;
 171   int argc;
 172   wchar_t **wargv, **wenvp;
 173   _startupinfo si = { 0 };
 174   char c;
 175
 176   g_assert (__argc >= ARG_COUNT);
 177
 178   /* Fetch the wide-char argument vector */
 179   __wgetmainargs (&argc, &wargv, &wenvp, 0, &si);
 180
 181   /* We still have the system codepage args in __argv. We can look
 182    * at the first args in which gspawn-win32.c passes us flags and
 183    * fd numbers in __argv, as we know those are just ASCII anyway.
 184    */
 185   g_assert (argc == __argc);
 186
 187   /* argv[ARG_CHILD_ERR_REPORT] is the file descriptor number onto
 188    * which write error messages.
 189    */
 190   child_err_report_fd = atoi (__argv[ARG_CHILD_ERR_REPORT]);
 191
 192   /* Hack to implement G_SPAWN_FILE_AND_ARGV_ZERO. If
 193    * argv[ARG_CHILD_ERR_REPORT] is suffixed with a '#' it means we get
 194    * the program to run and its argv[0] separately.
 195    */
 196   if (__argv[ARG_CHILD_ERR_REPORT][strlen (__argv[ARG_CHILD_ERR_REPORT]) - 1] == '#')
 197     argv_zero_offset++;
 198
 199   /* argv[ARG_HELPER_SYNC] is the file descriptor number we read a
 200    * byte that tells us it is OK to exit. We have to wait until the
 201    * parent allows us to exit, so that the parent has had time to
 202    * duplicate the process handle we sent it. Duplicating a handle
 203    * from another process works only if that other process exists.
 204    */
 205   helper_sync_fd = atoi (__argv[ARG_HELPER_SYNC]);
 206
 207   /* argv[ARG_STDIN..ARG_STDERR] are the file descriptor numbers that
 208    * should be dup2'd to 0, 1 and 2. '-' if the corresponding fd
 209    * should be left alone, and 'z' if it should be connected to the
 210    * bit bucket NUL:.
 211    */
 212   if (__argv[ARG_STDIN][0] == '-')
 213     ; /* Nothing */
 214   else if (__argv[ARG_STDIN][0] == 'z')
 215     {
 216       fd = open ("NUL:", O_RDONLY);
 217       if (fd != 0)
 218         {
 219           dup2 (fd, 0);
 220           close (fd);
 221         }
 222     }
 223   else
 224     {
 225       fd = atoi (__argv[ARG_STDIN]);
 226       if (fd != 0)
 227         {
 228           dup2 (fd, 0);
 229           close (fd);
 230         }
 231     }
 232
 233   if (__argv[ARG_STDOUT][0] == '-')
 234     ; /* Nothing */
 235   else if (__argv[ARG_STDOUT][0] == 'z')
 236     {
 237       fd = open ("NUL:", O_WRONLY);
 238       if (fd != 1)
 239         {
 240           dup2 (fd, 1);
 241           close (fd);
 242         }
 243     }
 244   else
 245     {
 246       fd = atoi (__argv[ARG_STDOUT]);
 247       if (fd != 1)
 248         {
 249           dup2 (fd, 1);
 250           close (fd);
 251         }
 252     }
 253
 254   if (__argv[ARG_STDERR][0] == '-')
 255     ; /* Nothing */
 256   else if (__argv[ARG_STDERR][0] == 'z')
 257     {
 258       fd = open ("NUL:", O_WRONLY);
 259       if (fd != 2)
 260         {
 261           dup2 (fd, 2);
 262           close (fd);
 263         }
 264     }
 265   else
 266     {
 267       fd = atoi (__argv[ARG_STDERR]);
 268       if (fd != 2)
 269         {
 270           dup2 (fd, 2);
 271           close (fd);
 272         }
 273     }
 274
 275   /* __argv[ARG_WORKING_DIRECTORY] is the directory in which to run the
 276    * process.  If "-", don't change directory.
 277    */
 278   if (__argv[ARG_WORKING_DIRECTORY][0] == '-' &&
 279       __argv[ARG_WORKING_DIRECTORY][1] == 0)
 280     ; /* Nothing */
 281   else if (_wchdir (wargv[ARG_WORKING_DIRECTORY]) < 0)
 282     write_err_and_exit (child_err_report_fd, CHILD_CHDIR_FAILED);
 283
 284   /* __argv[ARG_CLOSE_DESCRIPTORS] is "y" if file descriptors from 3
 285    *  upwards should be closed
 286    */
 287   if (__argv[ARG_CLOSE_DESCRIPTORS][0] == 'y')
 288     for (i = 3; i < 1000; i++)  /* FIXME real limit? */
 289       if (i != child_err_report_fd && i != helper_sync_fd)
 290         close (i);
 291
 292   /* We don't want our child to inherit the error report and
 293    * helper sync fds.
 294    */
 295   child_err_report_fd = dup_noninherited (child_err_report_fd, _O_WRONLY);
 296   helper_sync_fd = dup_noninherited (helper_sync_fd, _O_RDONLY);
 297
 298   /* __argv[ARG_WAIT] is "w" to wait for the program to exit */
 299   if (__argv[ARG_WAIT][0] == 'w')
 300     mode = P_WAIT;
 301   else
 302     mode = P_NOWAIT;
 303
 304   /* __argv[ARG_USE_PATH] is "y" to use PATH, otherwise not */
 305
 306   /* __argv[ARG_PROGRAM] is executable file to run,
 307    * __argv[argv_zero_offset]... is its argv. argv_zero_offset equals
 308    * ARG_PROGRAM unless G_SPAWN_FILE_AND_ARGV_ZERO was used, in which
 309    * case we have a separate executable name and argv[0].
 310    */
 311
 312   /* For the program name passed to spawnv(), don't use the quoted
 313    * version.
 314    */
 315   protect_wargv (wargv + argv_zero_offset, &new_wargv);
 316
 317   if (__argv[ARG_USE_PATH][0] == 'y')
 318     handle = _wspawnvp (mode, wargv[ARG_PROGRAM], (const wchar_t **) new_wargv);
 319   else
 320     handle = _wspawnv (mode, wargv[ARG_PROGRAM], (const wchar_t **) new_wargv);
 321
 322   saved_errno = errno;
 323
 324   if (handle == -1 && saved_errno != 0)
 325     write_err_and_exit (child_err_report_fd, CHILD_SPAWN_FAILED);
 326
 327   write (child_err_report_fd, &no_error, sizeof (no_error));
 328   write (child_err_report_fd, &handle, sizeof (handle));
 329
 330   read (helper_sync_fd, &c, 1);
 331
 332   return 0;
 333 }