lib-src/ntlib.c

   1 /* Utility and Unix shadow routines for GNU Emacs support programs on NT.
   2
   3 Copyright (C) 1994, 2001-2015 Free Software Foundation, Inc.
   4
   5 Author: Geoff Voelker (voelker@cs.washington.edu)
   6 Created: 10-8-94
   7
   8 This file is part of GNU Emacs.
   9
  10 GNU Emacs is free software: you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation, either version 3 of the License, or
  13 (at your option) any later version.
  14
  15 GNU Emacs is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #include <windows.h>
  24 #include <stdlib.h>
  25 #include <stdio.h>
  26 #include <time.h>
  27 #include <direct.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <errno.h>
  31 #include <ctype.h>
  32 #include <sys/timeb.h>
  33 #include <mbstring.h>
  34
  35 #include "ntlib.h"
  36
  37 /* MinGW64 defines _TIMEZONE_DEFINED and defines 'struct timespec' in
  38    its system headers.  */
  39 #ifndef _TIMEZONE_DEFINED
  40 struct timezone
  41 {
  42   int           tz_minuteswest; /* minutes west of Greenwich */
  43   int           tz_dsttime;     /* type of dst correction */
  44 };
  45 #endif
  46
  47 #define MAXPATHLEN _MAX_PATH
  48
  49 /* Emulate sleep...we could have done this with a define, but that
  50    would necessitate including windows.h in the files that used it.
  51    This is much easier.  */
  52 unsigned
  53 sleep (unsigned seconds)
  54 {
  55   Sleep (seconds * 1000);
  56   return 0;
  57 }
  58
  59 /* Get the current working directory.  */
  60 char *
  61 getwd (char *dir)
  62 {
  63   if (GetCurrentDirectory (MAXPATHLEN, dir) > 0)
  64     return dir;
  65   return NULL;
  66 }
  67
  68 static HANDLE getppid_parent;
  69 static int    getppid_ppid;
  70
  71 int
  72 getppid (void)
  73 {
  74   char *ppid;
  75   DWORD result;
  76
  77   ppid = getenv ("EM_PARENT_PROCESS_ID");
  78   if (!ppid)
  79     {
  80       printf ("no pid.\n");
  81       return 0;
  82     }
  83   else
  84     {
  85       getppid_ppid = atoi (ppid);
  86     }
  87
  88   if (!getppid_parent)
  89     {
  90       getppid_parent = OpenProcess (SYNCHRONIZE, FALSE, atoi (ppid));
  91       if (!getppid_parent)
  92         {
  93           printf ("Failed to open handle to parent process: %d\n",
  94                  GetLastError ());
  95           exit (1);
  96         }
  97     }
  98
  99   result = WaitForSingleObject (getppid_parent, 0);
 100   switch (result)
 101     {
 102     case WAIT_TIMEOUT:
 103       /* The parent is still alive.  */
 104       return getppid_ppid;
 105     case WAIT_OBJECT_0:
 106       /* The parent is gone.  Return the pid of Unix init (1).  */
 107       return 1;
 108     case WAIT_FAILED:
 109     default:
 110       printf ("Checking parent status failed: %d\n", GetLastError ());
 111       exit (1);
 112     }
 113 }
 114
 115 char *
 116 getlogin (void)
 117 {
 118   static char user_name[256];
 119   DWORD  length = sizeof (user_name);
 120
 121   if (GetUserName (user_name, &length))
 122     return user_name;
 123   return NULL;
 124 }
 125
 126 char *
 127 cuserid (char * s)
 128 {
 129   char * name = getlogin ();
 130   if (s)
 131     return strcpy (s, name ? name : "");
 132   return name;
 133 }
 134
 135 unsigned
 136 getuid (void)
 137 {
 138   return 0;
 139 }
 140
 141 unsigned
 142 geteuid (void)
 143 {
 144   return getuid ();
 145 }
 146
 147 unsigned
 148 getgid (void)
 149 {
 150   return 0;
 151 }
 152
 153 unsigned
 154 getegid (void)
 155 {
 156   return 0;
 157 }
 158
 159 int
 160 setuid (unsigned uid)
 161 {
 162   return 0;
 163 }
 164
 165 int
 166 setregid (unsigned rgid, unsigned gid)
 167 {
 168   return 0;
 169 }
 170
 171 struct passwd *
 172 getpwuid (unsigned uid)
 173 {
 174   return NULL;
 175 }
 176
 177 char *
 178 getpass (const char * prompt)
 179 {
 180   static char input[256];
 181   HANDLE in;
 182   HANDLE err;
 183   DWORD  count;
 184
 185   in = GetStdHandle (STD_INPUT_HANDLE);
 186   err = GetStdHandle (STD_ERROR_HANDLE);
 187
 188   if (in == INVALID_HANDLE_VALUE || err == INVALID_HANDLE_VALUE)
 189     return NULL;
 190
 191   if (WriteFile (err, prompt, strlen (prompt), &count, NULL))
 192     {
 193       int istty = (GetFileType (in) == FILE_TYPE_CHAR);
 194       DWORD old_flags;
 195       int rc;
 196
 197       if (istty)
 198         {
 199           if (GetConsoleMode (in, &old_flags))
 200             SetConsoleMode (in, ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT);
 201           else
 202             istty = 0;
 203         }
 204       rc = ReadFile (in, input, sizeof (input), &count, NULL);
 205       if (count >= 2 && input[count - 2] == '\r')
 206         input[count - 2] = '\0';
 207       else
 208         {
 209           char buf[256];
 210           while (ReadFile (in, buf, sizeof (buf), &count, NULL) > 0)
 211             if (count >= 2 && buf[count - 2] == '\r')
 212               break;
 213         }
 214       WriteFile (err, "\r\n", 2, &count, NULL);
 215       if (istty)
 216         SetConsoleMode (in, old_flags);
 217       if (rc)
 218         return input;
 219     }
 220
 221   return NULL;
 222 }
 223
 224 /* This is needed because lib/gettime.c calls gettimeofday, which MSVC
 225    doesn't have.  Copied from w32.c.  */
 226 void
 227 gettimeofday (struct timeval *tv, struct timezone *tz)
 228 {
 229   struct _timeb tb;
 230   _ftime (&tb);
 231
 232   tv->tv_sec = tb.time;
 233   tv->tv_usec = tb.millitm * 1000L;
 234   /* Implementation note: _ftime sometimes doesn't update the dstflag
 235      according to the new timezone when the system timezone is
 236      changed.  We could fix that by using GetSystemTime and
 237      GetTimeZoneInformation, but that doesn't seem necessary, since
 238      Emacs always calls gettimeofday with the 2nd argument NULL (see
 239      current_emacs_time).  */
 240   if (tz)
 241     {
 242       tz->tz_minuteswest = tb.timezone; /* minutes west of Greenwich  */
 243       tz->tz_dsttime = tb.dstflag;      /* type of dst correction  */
 244     }
 245 }
 246
 247 int
 248 fchown (int fd, unsigned uid, unsigned gid)
 249 {
 250   return 0;
 251 }
 252
 253 /* Place a wrapper around the MSVC version of ctime.  It returns NULL
 254    on network directories, so we handle that case here.
 255    (Ulrich Leodolter, 1/11/95).  */
 256 char *
 257 sys_ctime (const time_t *t)
 258 {
 259   char *str = (char *) ctime (t);
 260   return (str ? str : "Sun Jan 01 00:00:00 1970");
 261 }
 262
 263 FILE *
 264 sys_fopen (const char * path, const char * mode)
 265 {
 266   return fopen (path, mode);
 267 }
 268
 269 int
 270 sys_chdir (const char * path)
 271 {
 272   return _chdir (path);
 273 }
 274
 275 static FILETIME utc_base_ft;
 276 static long double utc_base;
 277 static int init = 0;
 278
 279 static time_t
 280 convert_time (FILETIME ft)
 281 {
 282   long double ret;
 283
 284   if (CompareFileTime (&ft, &utc_base_ft) < 0)
 285     return 0;
 286
 287   ret = (long double) ft.dwHighDateTime
 288     * 4096.0L * 1024.0L * 1024.0L + ft.dwLowDateTime;
 289   ret -= utc_base;
 290   return (time_t) (ret * 1e-7L);
 291 }
 292
 293 static int
 294 is_exec (const char * name)
 295 {
 296   char * p = strrchr (name, '.');
 297   return
 298     (p != NULL
 299      && (stricmp (p, ".exe") == 0 ||
 300          stricmp (p, ".com") == 0 ||
 301          stricmp (p, ".bat") == 0 ||
 302          stricmp (p, ".cmd") == 0));
 303 }
 304
 305 /* FIXME?  This is in config.nt now - is this still needed?  */
 306 #define IS_DIRECTORY_SEP(x) ((x) == '/' || (x) == '\\')
 307
 308 /* We need this because nt/inc/sys/stat.h defines struct stat that is
 309    incompatible with the MS run-time libraries.  */
 310 int
 311 stat (const char * path, struct stat * buf)
 312 {
 313   WIN32_FIND_DATA wfd;
 314   HANDLE fh;
 315   int permission;
 316   int len;
 317   int rootdir = FALSE;
 318   char *name = alloca (FILENAME_MAX);
 319
 320   if (!init)
 321     {
 322       /* Determine the delta between 1-Jan-1601 and 1-Jan-1970. */
 323       SYSTEMTIME st;
 324
 325       st.wYear = 1970;
 326       st.wMonth = 1;
 327       st.wDay = 1;
 328       st.wHour = 0;
 329       st.wMinute = 0;
 330       st.wSecond = 0;
 331       st.wMilliseconds = 0;
 332
 333       SystemTimeToFileTime (&st, &utc_base_ft);
 334       utc_base = (long double) utc_base_ft.dwHighDateTime
 335         * 4096.0L * 1024.0L * 1024.0L + utc_base_ft.dwLowDateTime;
 336       init = 1;
 337     }
 338
 339   if (path == NULL || buf == NULL || *path == '\0')
 340     {
 341       errno = EFAULT;
 342       return -1;
 343     }
 344   if (_mbspbrk (path, "*?|<>\""))
 345     {
 346       errno = ENOENT;
 347       return -1;
 348     }
 349
 350   strcpy (name, path);
 351   /* Remove trailing directory separator, unless name is the root
 352      directory of a drive in which case ensure there is a trailing
 353      separator. */
 354   len = strlen (name);
 355   rootdir = IS_DIRECTORY_SEP (name[0])
 356     || (len == 3 && name[1] == ':' && IS_DIRECTORY_SEP (name[2]));
 357   if (rootdir)
 358     {
 359       if (GetDriveType (name) < 2)
 360         {
 361           errno = ENOENT;
 362           return -1;
 363         }
 364       memset (&wfd, 0, sizeof (wfd));
 365       wfd.dwFileAttributes = FILE_ATTRIBUTE_DIRECTORY;
 366       wfd.ftCreationTime = utc_base_ft;
 367       wfd.ftLastAccessTime = utc_base_ft;
 368       wfd.ftLastWriteTime = utc_base_ft;
 369       strcpy (wfd.cFileName, name);
 370     }
 371   else
 372     {
 373       if (IS_DIRECTORY_SEP (name[len-1]))
 374         name[len - 1] = 0;
 375
 376       fh = FindFirstFile (name, &wfd);
 377       if (fh == INVALID_HANDLE_VALUE)
 378         {
 379           errno = ENOENT;
 380           return -1;
 381         }
 382       FindClose (fh);
 383     }
 384   buf->st_mode = (wfd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ?
 385     S_IFDIR : S_IFREG;
 386   buf->st_nlink = 1;
 387   buf->st_ino = 0;
 388
 389   if (name[0] && name[1] == ':')
 390     buf->st_dev = tolower (name[0]) - 'a' + 1;
 391   else
 392     buf->st_dev = _getdrive ();
 393   buf->st_rdev = buf->st_dev;
 394
 395   buf->st_size = wfd.nFileSizeLow;
 396
 397   /* Convert timestamps to Unix format. */
 398   buf->st_mtime = convert_time (wfd.ftLastWriteTime);
 399   buf->st_atime = convert_time (wfd.ftLastAccessTime);
 400   if (buf->st_atime == 0) buf->st_atime = buf->st_mtime;
 401   buf->st_ctime = convert_time (wfd.ftCreationTime);
 402   if (buf->st_ctime == 0) buf->st_ctime = buf->st_mtime;
 403
 404   /* determine rwx permissions */
 405   if (wfd.dwFileAttributes & FILE_ATTRIBUTE_READONLY)
 406     permission = S_IREAD;
 407   else
 408     permission = S_IREAD | S_IWRITE;
 409
 410   if (wfd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
 411     permission |= S_IEXEC;
 412   else if (is_exec (name))
 413     permission |= S_IEXEC;
 414
 415   buf->st_mode |= permission | (permission >> 3) | (permission >> 6);
 416
 417   return 0;
 418 }
 419
 420 int
 421 lstat (const char * path, struct stat * buf)
 422 {
 423   return stat (path, buf);
 424 }
 425
 426 /* Implementation of mkostemp for MS-Windows, to avoid race conditions
 427    when using mktemp.  Copied from w32.c.
 428
 429    This is used only in update-game-score.c.  It is overkill for that
 430    use case, since update-game-score renames the temporary file into
 431    the game score file, which isn't atomic on MS-Windows anyway, when
 432    the game score already existed before running the program, which it
 433    almost always does.  But using a simpler implementation just to
 434    make a point is uneconomical...  */
 435
 436 int
 437 mkostemp (char * template, int flags)
 438 {
 439   char * p;
 440   int i, fd = -1;
 441   unsigned uid = GetCurrentThreadId ();
 442   int save_errno = errno;
 443   static char first_char[] = "abcdefghijklmnopqrstuvwyz0123456789!%-_@#";
 444
 445   errno = EINVAL;
 446   if (template == NULL)
 447     return -1;
 448
 449   p = template + strlen (template);
 450   i = 5;
 451   /* replace up to the last 5 X's with uid in decimal */
 452   while (--p >= template && p[0] == 'X' && --i >= 0)
 453     {
 454       p[0] = '0' + uid % 10;
 455       uid /= 10;
 456     }
 457
 458   if (i < 0 && p[0] == 'X')
 459     {
 460       i = 0;
 461       do
 462         {
 463           p[0] = first_char[i];
 464           if ((fd = open (template,
 465                           flags | _O_CREAT | _O_EXCL | _O_RDWR,
 466                           S_IRUSR | S_IWUSR)) >= 0
 467               || errno != EEXIST)
 468             {
 469               if (fd >= 0)
 470                 errno = save_errno;
 471               return fd;
 472             }
 473         }
 474       while (++i < sizeof (first_char));
 475     }
 476
 477   /* Template is badly formed or else we can't generate a unique name.  */
 478   return -1;
 479 }
 480
 481 /* On Windows, you cannot rename into an existing file.  */
 482 int
 483 sys_rename (const char *from, const char *to)
 484 {
 485   int retval = rename (from, to);
 486
 487   if (retval < 0 && errno == EEXIST)
 488     {
 489       if (unlink (to) == 0)
 490         retval = rename (from, to);
 491     }
 492   return retval;
 493 }