lib-src/ntlib.c

   1 /* Utility and Unix shadow routines for GNU Emacs support programs on NT.
   2
   3 Copyright (C) 1994, 2001-2017 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 (at
  13 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 char *sys_ctime (const time_t *);
  38 FILE *sys_fopen (const char *, const char *);
  39 int sys_chdir (const char *);
  40 int mkostemp (char *, int);
  41 int sys_rename (const char *, const char *);
  42
  43 /* MinGW64 defines _TIMEZONE_DEFINED and defines 'struct timespec' in
  44    its system headers.  */
  45 #ifndef _TIMEZONE_DEFINED
  46 struct timezone
  47 {
  48   int           tz_minuteswest; /* minutes west of Greenwich */
  49   int           tz_dsttime;     /* type of dst correction */
  50 };
  51 #endif
  52
  53 void gettimeofday (struct timeval *, struct timezone *);
  54
  55 #define MAXPATHLEN _MAX_PATH
  56
  57 /* Emulate sleep...we could have done this with a define, but that
  58    would necessitate including windows.h in the files that used it.
  59    This is much easier.  */
  60 unsigned
  61 sleep (unsigned seconds)
  62 {
  63   Sleep (seconds * 1000);
  64   return 0;
  65 }
  66
  67 /* Get the current working directory.  */
  68 char *
  69 getwd (char *dir)
  70 {
  71   if (GetCurrentDirectory (MAXPATHLEN, dir) > 0)
  72     return dir;
  73   return NULL;
  74 }
  75
  76 static HANDLE getppid_parent;
  77 static int    getppid_ppid;
  78
  79 int
  80 getppid (void)
  81 {
  82   char *ppid;
  83   DWORD result;
  84
  85   ppid = getenv ("EM_PARENT_PROCESS_ID");
  86   if (!ppid)
  87     {
  88       printf ("no pid.\n");
  89       return 0;
  90     }
  91   else
  92     {
  93       getppid_ppid = atoi (ppid);
  94     }
  95
  96   if (!getppid_parent)
  97     {
  98       getppid_parent = OpenProcess (SYNCHRONIZE, FALSE, atoi (ppid));
  99       if (!getppid_parent)
 100         {
 101           printf ("Failed to open handle to parent process: %lu\n",
 102                  GetLastError ());
 103           exit (1);
 104         }
 105     }
 106
 107   result = WaitForSingleObject (getppid_parent, 0);
 108   switch (result)
 109     {
 110     case WAIT_TIMEOUT:
 111       /* The parent is still alive.  */
 112       return getppid_ppid;
 113     case WAIT_OBJECT_0:
 114       /* The parent is gone.  Return the pid of Unix init (1).  */
 115       return 1;
 116     case WAIT_FAILED:
 117     default:
 118       printf ("Checking parent status failed: %lu\n", GetLastError ());
 119       exit (1);
 120     }
 121 }
 122
 123 char *
 124 getlogin (void)
 125 {
 126   static char user_name[256];
 127   DWORD  length = sizeof (user_name);
 128
 129   if (GetUserName (user_name, &length))
 130     return user_name;
 131   return NULL;
 132 }
 133
 134 char *
 135 cuserid (char * s)
 136 {
 137   char * name = getlogin ();
 138   if (s)
 139     return strcpy (s, name ? name : "");
 140   return name;
 141 }
 142
 143 unsigned
 144 getuid (void)
 145 {
 146   return 0;
 147 }
 148
 149 unsigned
 150 geteuid (void)
 151 {
 152   return getuid ();
 153 }
 154
 155 unsigned
 156 getgid (void)
 157 {
 158   return 0;
 159 }
 160
 161 unsigned
 162 getegid (void)
 163 {
 164   return 0;
 165 }
 166
 167 int
 168 setuid (unsigned uid)
 169 {
 170   return 0;
 171 }
 172
 173 int
 174 setregid (unsigned rgid, unsigned gid)
 175 {
 176   return 0;
 177 }
 178
 179 struct passwd *
 180 getpwuid (unsigned uid)
 181 {
 182   return NULL;
 183 }
 184
 185 char *
 186 getpass (const char * prompt)
 187 {
 188   static char input[256];
 189   HANDLE in;
 190   HANDLE err;
 191   DWORD  count;
 192
 193   in = GetStdHandle (STD_INPUT_HANDLE);
 194   err = GetStdHandle (STD_ERROR_HANDLE);
 195
 196   if (in == INVALID_HANDLE_VALUE || err == INVALID_HANDLE_VALUE)
 197     return NULL;
 198
 199   if (WriteFile (err, prompt, strlen (prompt), &count, NULL))
 200     {
 201       int istty = (GetFileType (in) == FILE_TYPE_CHAR);
 202       DWORD old_flags;
 203       int rc;
 204
 205       if (istty)
 206         {
 207           if (GetConsoleMode (in, &old_flags))
 208             SetConsoleMode (in, ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT);
 209           else
 210             istty = 0;
 211         }
 212       rc = ReadFile (in, input, sizeof (input), &count, NULL);
 213       if (count >= 2 && input[count - 2] == '\r')
 214         input[count - 2] = '\0';
 215       else
 216         {
 217           char buf[256];
 218           while (ReadFile (in, buf, sizeof (buf), &count, NULL) > 0)
 219             if (count >= 2 && buf[count - 2] == '\r')
 220               break;
 221         }
 222       WriteFile (err, "\r\n", 2, &count, NULL);
 223       if (istty)
 224         SetConsoleMode (in, old_flags);
 225       if (rc)
 226         return input;
 227     }
 228
 229   return NULL;
 230 }
 231
 232 /* This is needed because lib/gettime.c calls gettimeofday, which MSVC
 233    doesn't have.  Copied from w32.c.  */
 234 void
 235 gettimeofday (struct timeval *tv, struct timezone *tz)
 236 {
 237   struct _timeb tb;
 238   _ftime (&tb);
 239
 240   tv->tv_sec = tb.time;
 241   tv->tv_usec = tb.millitm * 1000L;
 242   /* Implementation note: _ftime sometimes doesn't update the dstflag
 243      according to the new timezone when the system timezone is
 244      changed.  We could fix that by using GetSystemTime and
 245      GetTimeZoneInformation, but that doesn't seem necessary, since
 246      Emacs always calls gettimeofday with the 2nd argument NULL (see
 247      current_emacs_time).  */
 248   if (tz)
 249     {
 250       tz->tz_minuteswest = tb.timezone; /* minutes west of Greenwich  */
 251       tz->tz_dsttime = tb.dstflag;      /* type of dst correction  */
 252     }
 253 }
 254
 255 int
 256 fchown (int fd, unsigned uid, unsigned gid)
 257 {
 258   return 0;
 259 }
 260
 261 FILE *
 262 sys_fopen (const char * path, const char * mode)
 263 {
 264   return fopen (path, mode);
 265 }
 266
 267 int
 268 sys_chdir (const char * path)
 269 {
 270   return _chdir (path);
 271 }
 272
 273 static FILETIME utc_base_ft;
 274 static long double utc_base;
 275 static int init = 0;
 276
 277 static time_t
 278 convert_time (FILETIME ft)
 279 {
 280   long double ret;
 281
 282   if (CompareFileTime (&ft, &utc_base_ft) < 0)
 283     return 0;
 284
 285   ret = (long double) ft.dwHighDateTime
 286     * 4096.0L * 1024.0L * 1024.0L + ft.dwLowDateTime;
 287   ret -= utc_base;
 288   return (time_t) (ret * 1e-7L);
 289 }
 290
 291 static int
 292 is_exec (const char * name)
 293 {
 294   char * p = strrchr (name, '.');
 295   return
 296     (p != NULL
 297      && (stricmp (p, ".exe") == 0 ||
 298          stricmp (p, ".com") == 0 ||
 299          stricmp (p, ".bat") == 0 ||
 300          stricmp (p, ".cmd") == 0));
 301 }
 302
 303 /* FIXME?  This is in configure.ac now - is this still needed?  */
 304 #define IS_DIRECTORY_SEP(x) ((x) == '/' || (x) == '\\')
 305
 306 /* We need this because nt/inc/sys/stat.h defines struct stat that is
 307    incompatible with the MS run-time libraries.  */
 308 int
 309 stat (const char * path, struct stat * buf)
 310 {
 311   WIN32_FIND_DATA wfd;
 312   HANDLE fh;
 313   int permission;
 314   int len;
 315   int rootdir = FALSE;
 316   char *name = alloca (FILENAME_MAX);
 317
 318   if (!init)
 319     {
 320       /* Determine the delta between 1-Jan-1601 and 1-Jan-1970. */
 321       SYSTEMTIME st;
 322
 323       st.wYear = 1970;
 324       st.wMonth = 1;
 325       st.wDay = 1;
 326       st.wHour = 0;
 327       st.wMinute = 0;
 328       st.wSecond = 0;
 329       st.wMilliseconds = 0;
 330
 331       SystemTimeToFileTime (&st, &utc_base_ft);
 332       utc_base = (long double) utc_base_ft.dwHighDateTime
 333         * 4096.0L * 1024.0L * 1024.0L + utc_base_ft.dwLowDateTime;
 334       init = 1;
 335     }
 336
 337   if (path == NULL || buf == NULL || *path == '\0')
 338     {
 339       errno = EFAULT;
 340       return -1;
 341     }
 342   if (_mbspbrk (path, "*?|<>\""))
 343     {
 344       errno = ENOENT;
 345       return -1;
 346     }
 347
 348   strcpy (name, path);
 349   /* Remove trailing directory separator, unless name is the root
 350      directory of a drive in which case ensure there is a trailing
 351      separator. */
 352   len = strlen (name);
 353   rootdir = IS_DIRECTORY_SEP (name[0])
 354     || (len == 3 && name[1] == ':' && IS_DIRECTORY_SEP (name[2]));
 355   if (rootdir)
 356     {
 357       if (GetDriveType (name) < 2)
 358         {
 359           errno = ENOENT;
 360           return -1;
 361         }
 362       memset (&wfd, 0, sizeof (wfd));
 363       wfd.dwFileAttributes = FILE_ATTRIBUTE_DIRECTORY;
 364       wfd.ftCreationTime = utc_base_ft;
 365       wfd.ftLastAccessTime = utc_base_ft;
 366       wfd.ftLastWriteTime = utc_base_ft;
 367       strcpy (wfd.cFileName, name);
 368     }
 369   else
 370     {
 371       if (IS_DIRECTORY_SEP (name[len-1]))
 372         name[len - 1] = 0;
 373
 374       fh = FindFirstFile (name, &wfd);
 375       if (fh == INVALID_HANDLE_VALUE)
 376         {
 377           errno = ENOENT;
 378           return -1;
 379         }
 380       FindClose (fh);
 381     }
 382   buf->st_mode = (wfd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ?
 383     S_IFDIR : S_IFREG;
 384   buf->st_nlink = 1;
 385   buf->st_ino = 0;
 386
 387   if (name[0] && name[1] == ':')
 388     buf->st_dev = tolower (name[0]) - 'a' + 1;
 389   else
 390     buf->st_dev = _getdrive ();
 391   buf->st_rdev = buf->st_dev;
 392
 393   buf->st_size = wfd.nFileSizeLow;
 394
 395   /* Convert timestamps to Unix format. */
 396   buf->st_mtime = convert_time (wfd.ftLastWriteTime);
 397   buf->st_atime = convert_time (wfd.ftLastAccessTime);
 398   if (buf->st_atime == 0) buf->st_atime = buf->st_mtime;
 399   buf->st_ctime = convert_time (wfd.ftCreationTime);
 400   if (buf->st_ctime == 0) buf->st_ctime = buf->st_mtime;
 401
 402   /* determine rwx permissions */
 403   if (wfd.dwFileAttributes & FILE_ATTRIBUTE_READONLY)
 404     permission = S_IREAD;
 405   else
 406     permission = S_IREAD | S_IWRITE;
 407
 408   if (wfd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
 409     permission |= S_IEXEC;
 410   else if (is_exec (name))
 411     permission |= S_IEXEC;
 412
 413   buf->st_mode |= permission | (permission >> 3) | (permission >> 6);
 414
 415   return 0;
 416 }
 417
 418 int
 419 lstat (const char * path, struct stat * buf)
 420 {
 421   return stat (path, buf);
 422 }
 423
 424 /* Implementation of mkostemp for MS-Windows, to avoid race conditions
 425    when using mktemp.  Copied from w32.c.
 426
 427    This is used only in update-game-score.c.  It is overkill for that
 428    use case, since update-game-score renames the temporary file into
 429    the game score file, which isn't atomic on MS-Windows anyway, when
 430    the game score already existed before running the program, which it
 431    almost always does.  But using a simpler implementation just to
 432    make a point is uneconomical...  */
 433
 434 int
 435 mkostemp (char * template, int flags)
 436 {
 437   char * p;
 438   int i, fd = -1;
 439   unsigned uid = GetCurrentThreadId ();
 440   int save_errno = errno;
 441   static char first_char[] = "abcdefghijklmnopqrstuvwyz0123456789!%-_@#";
 442
 443   errno = EINVAL;
 444   if (template == NULL)
 445     return -1;
 446
 447   p = template + strlen (template);
 448   i = 5;
 449   /* replace up to the last 5 X's with uid in decimal */
 450   while (--p >= template && p[0] == 'X' && --i >= 0)
 451     {
 452       p[0] = '0' + uid % 10;
 453       uid /= 10;
 454     }
 455
 456   if (i < 0 && p[0] == 'X')
 457     {
 458       i = 0;
 459       do
 460         {
 461           p[0] = first_char[i];
 462           if ((fd = open (template,
 463                           flags | _O_CREAT | _O_EXCL | _O_RDWR,
 464                           S_IRUSR | S_IWUSR)) >= 0
 465               || errno != EEXIST)
 466             {
 467               if (fd >= 0)
 468                 errno = save_errno;
 469               return fd;
 470             }
 471         }
 472       while (++i < sizeof (first_char));
 473     }
 474
 475   /* Template is badly formed or else we can't generate a unique name.  */
 476   return -1;
 477 }
 478
 479 /* On Windows, you cannot rename into an existing file.  */
 480 int
 481 sys_rename (const char *from, const char *to)
 482 {
 483   int retval = rename (from, to);
 484
 485   if (retval < 0 && errno == EEXIST)
 486     {
 487       if (unlink (to) == 0)
 488         retval = rename (from, to);
 489     }
 490   return retval;
 491 }