dlls/ntdll/path.c

   1 /*
   2  * Ntdll path functions
   3  *
   4  * Copyright 2002, 2003 Alexandre Julliard
   5  * Copyright 2003 Eric Pouech
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include "config.h"
  23
  24 #include <stdarg.h>
  25
  26 #include "windef.h"
  27 #include "winbase.h"
  28 #include "winreg.h"
  29 #include "winternl.h"
  30 #include "wine/unicode.h"
  31 #include "wine/debug.h"
  32 #include "ntdll_misc.h"
  33
  34 WINE_DEFAULT_DEBUG_CHANNEL(file);
  35
  36 static const WCHAR DeviceRootW[] = {'\\','\\','.','\\',0};
  37 static const WCHAR NTDosPrefixW[] = {'\\','?','?','\\',0};
  38 static const WCHAR UncPfxW[] = {'U','N','C','\\',0};
  39
  40 /* FIXME: hack! */
  41 HANDLE (WINAPI *pCreateFileW)( LPCWSTR filename, DWORD access, DWORD sharing,
  42                                LPSECURITY_ATTRIBUTES sa, DWORD creation,
  43                                DWORD attributes, HANDLE template );
  44
  45 #define IS_SEPARATOR(ch)  ((ch) == '\\' || (ch) == '/')
  46
  47 /***********************************************************************
  48  *             RtlDetermineDosPathNameType_U   (NTDLL.@)
  49  */
  50 DOS_PATHNAME_TYPE WINAPI RtlDetermineDosPathNameType_U( PCWSTR path )
  51 {
  52     if (IS_SEPARATOR(path[0]))
  53     {
  54         if (!IS_SEPARATOR(path[1])) return ABSOLUTE_PATH;       /* "/foo" */
  55         if (path[2] != '.') return UNC_PATH;                    /* "//foo" */
  56         if (IS_SEPARATOR(path[3])) return DEVICE_PATH;          /* "//./foo" */
  57         if (path[3]) return UNC_PATH;                           /* "//.foo" */
  58         return UNC_DOT_PATH;                                    /* "//." */
  59     }
  60     else
  61     {
  62         if (!path[0] || path[1] != ':') return RELATIVE_PATH;   /* "foo" */
  63         if (IS_SEPARATOR(path[2])) return ABSOLUTE_DRIVE_PATH;  /* "c:/foo" */
  64         return RELATIVE_DRIVE_PATH;                             /* "c:foo" */
  65     }
  66 }
  67
  68 /******************************************************************
  69  *              RtlDoesFileExists_U
  70  *
  71  * FIXME: should not use CreateFileW
  72  */
  73 BOOLEAN WINAPI RtlDoesFileExists_U(LPCWSTR file_name)
  74 {
  75     HANDLE handle = pCreateFileW( file_name, 0, FILE_SHARE_READ|FILE_SHARE_WRITE,
  76                                   NULL, OPEN_EXISTING, 0, 0 );
  77     if (handle == INVALID_HANDLE_VALUE) return FALSE;
  78     NtClose( handle );
  79     return TRUE;
  80 }
  81
  82 /***********************************************************************
  83  *             RtlIsDosDeviceName_U   (NTDLL.@)
  84  *
  85  * Check if the given DOS path contains a DOS device name.
  86  *
  87  * Returns the length of the device name in the low word and its
  88  * position in the high word (both in bytes, not WCHARs), or 0 if no
  89  * device name is found.
  90  */
  91 ULONG WINAPI RtlIsDosDeviceName_U( PCWSTR dos_name )
  92 {
  93     static const WCHAR consoleW[] = {'\\','\\','.','\\','C','O','N',0};
  94     static const WCHAR auxW[3] = {'A','U','X'};
  95     static const WCHAR comW[3] = {'C','O','M'};
  96     static const WCHAR conW[3] = {'C','O','N'};
  97     static const WCHAR lptW[3] = {'L','P','T'};
  98     static const WCHAR nulW[3] = {'N','U','L'};
  99     static const WCHAR prnW[3] = {'P','R','N'};
 100
 101     const WCHAR *start, *end, *p;
 102
 103     switch(RtlDetermineDosPathNameType_U( dos_name ))
 104     {
 105     case INVALID_PATH:
 106     case UNC_PATH:
 107         return 0;
 108     case DEVICE_PATH:
 109         if (!strcmpiW( dos_name, consoleW ))
 110             return MAKELONG( sizeof(conW), 4 * sizeof(WCHAR) );  /* 4 is length of \\.\ prefix */
 111         return 0;
 112     default:
 113         break;
 114     }
 115
 116     end = dos_name + strlenW(dos_name) - 1;
 117     if (end >= dos_name && *end == ':') end--;  /* remove trailing ':' */
 118
 119     /* find start of file name */
 120     for (start = end; start >= dos_name; start--)
 121     {
 122         if (IS_SEPARATOR(start[0])) break;
 123         /* check for ':' but ignore if before extension (for things like NUL:.txt) */
 124         if (start[0] == ':' && start[1] != '.') break;
 125     }
 126     start++;
 127
 128     /* remove extension */
 129     if ((p = strchrW( start, '.' )))
 130     {
 131         end = p - 1;
 132         if (end >= dos_name && *end == ':') end--;  /* remove trailing ':' before extension */
 133     }
 134     else
 135     {
 136         /* no extension, remove trailing spaces */
 137         while (end >= dos_name && *end == ' ') end--;
 138     }
 139
 140     /* now we have a potential device name between start and end, check it */
 141     switch(end - start + 1)
 142     {
 143     case 3:
 144         if (strncmpiW( start, auxW, 3 ) &&
 145             strncmpiW( start, conW, 3 ) &&
 146             strncmpiW( start, nulW, 3 ) &&
 147             strncmpiW( start, prnW, 3 )) break;
 148         return MAKELONG( 3 * sizeof(WCHAR), (start - dos_name) * sizeof(WCHAR) );
 149     case 4:
 150         if (strncmpiW( start, comW, 3 ) && strncmpiW( start, lptW, 3 )) break;
 151         if (*end <= '0' || *end > '9') break;
 152         return MAKELONG( 4 * sizeof(WCHAR), (start - dos_name) * sizeof(WCHAR) );
 153     default:  /* can't match anything */
 154         break;
 155     }
 156     return 0;
 157 }
 158
 159
 160 /**************************************************************************
 161  *                 RtlDosPathNameToNtPathName_U         [NTDLL.@]
 162  *
 163  * dos_path: a DOS path name (fully qualified or not)
 164  * ntpath:   pointer to a UNICODE_STRING to hold the converted
 165  *           path name
 166  * file_part:will point (in ntpath) to the file part in the path
 167  * cd:       directory reference (optional)
 168  *
 169  * FIXME:
 170  *      + fill the cd structure
 171  */
 172 BOOLEAN  WINAPI RtlDosPathNameToNtPathName_U(PWSTR dos_path,
 173                                              PUNICODE_STRING ntpath,
 174                                              PWSTR* file_part,
 175                                              CURDIR* cd)
 176 {
 177     static const WCHAR LongFileNamePfxW[4] = {'\\','\\','?','\\'};
 178     ULONG sz, ptr_sz, offset;
 179     WCHAR local[MAX_PATH];
 180     LPWSTR ptr;
 181
 182     TRACE("(%s,%p,%p,%p)\n",
 183           debugstr_w(dos_path), ntpath, file_part, cd);
 184
 185     if (cd)
 186     {
 187         FIXME("Unsupported parameter\n");
 188         memset(cd, 0, sizeof(*cd));
 189     }
 190
 191     if (!dos_path || !*dos_path) return FALSE;
 192
 193     if (!memcmp(dos_path, LongFileNamePfxW, sizeof(LongFileNamePfxW)))
 194     {
 195         dos_path += sizeof(LongFileNamePfxW) / sizeof(WCHAR);
 196         ptr = NULL;
 197         ptr_sz = 0;
 198     }
 199     else
 200     {
 201         ptr = local;
 202         ptr_sz = sizeof(local);
 203     }
 204     sz = RtlGetFullPathName_U(dos_path, ptr_sz, ptr, file_part);
 205     if (sz == 0) return FALSE;
 206     if (sz > ptr_sz)
 207     {
 208         ptr = RtlAllocateHeap(ntdll_get_process_heap(), 0, sz);
 209         sz = RtlGetFullPathName_U(dos_path, sz, ptr, file_part);
 210     }
 211
 212     ntpath->MaximumLength = sz + (4 /* unc\ */ + 4 /* \??\ */) * sizeof(WCHAR);
 213     ntpath->Buffer = RtlAllocateHeap(ntdll_get_process_heap(), 0, ntpath->MaximumLength);
 214     if (!ntpath->Buffer)
 215     {
 216         if (ptr != local) RtlFreeHeap(ntdll_get_process_heap(), 0, ptr);
 217         return FALSE;
 218     }
 219
 220     strcpyW(ntpath->Buffer, NTDosPrefixW);
 221     offset = 0;
 222     switch (RtlDetermineDosPathNameType_U(ptr))
 223     {
 224     case UNC_PATH: /* \\foo */
 225         if (ptr[2] != '?')
 226         {
 227             offset = 2;
 228             strcatW(ntpath->Buffer, UncPfxW);
 229         }
 230         break;
 231     case DEVICE_PATH: /* \\.\foo */
 232         offset = 4;
 233         break;
 234     default: break; /* needed to keep gcc quiet */
 235     }
 236
 237     strcatW(ntpath->Buffer, ptr + offset);
 238     ntpath->Length = strlenW(ntpath->Buffer) * sizeof(WCHAR);
 239
 240     if (file_part && *file_part)
 241         *file_part = ntpath->Buffer + ntpath->Length / sizeof(WCHAR) - strlenW(*file_part);
 242
 243     /* FIXME: cd filling */
 244
 245     if (ptr != local) RtlFreeHeap(ntdll_get_process_heap(), 0, ptr);
 246     return TRUE;
 247 }
 248
 249 /******************************************************************
 250  *              RtlDosSearchPath_U
 251  *
 252  * Searchs a file of name 'name' into a ';' separated list of paths
 253  * (stored in paths)
 254  * Doesn't seem to search elsewhere than the paths list
 255  * Stores the result in buffer (file_part will point to the position
 256  * of the file name in the buffer)
 257  * FIXME:
 258  * - how long shall the paths be ??? (MAX_PATH or larger with \\?\ constructs ???)
 259  */
 260 ULONG WINAPI RtlDosSearchPath_U(LPCWSTR paths, LPCWSTR search, LPCWSTR ext,
 261                                 ULONG buffer_size, LPWSTR buffer,
 262                                 LPWSTR* file_part)
 263 {
 264     DOS_PATHNAME_TYPE type = RtlDetermineDosPathNameType_U(search);
 265     ULONG len = 0;
 266
 267     if (type == RELATIVE_PATH)
 268     {
 269         ULONG allocated = 0, needed, filelen;
 270         WCHAR *name = NULL;
 271
 272         filelen = 1 /* for \ */ + strlenW(search) + 1 /* \0 */;
 273
 274         /* Windows only checks for '.' without worrying about path components */
 275         if (strchrW( search, '.' )) ext = NULL;
 276         if (ext != NULL) filelen += strlenW(ext);
 277
 278         while (*paths)
 279         {
 280             LPCWSTR ptr;
 281
 282             for (needed = 0, ptr = paths; *ptr != 0 && *ptr++ != ';'; needed++);
 283             if (needed + filelen > allocated)
 284             {
 285                 name = (WCHAR*)RtlReAllocateHeap(ntdll_get_process_heap(), 0,
 286                                                  name, (needed + filelen) * sizeof(WCHAR));
 287                 if (!name) return 0;
 288                 allocated = needed + filelen;
 289             }
 290             memmove(name, paths, needed * sizeof(WCHAR));
 291             /* append '\\' if none is present */
 292             if (needed > 0 && name[needed - 1] != '\\') name[needed++] = '\\';
 293             strcpyW(&name[needed], search);
 294             if (ext) strcatW(&name[needed], ext);
 295             if (RtlDoesFileExists_U(name))
 296             {
 297                 len = RtlGetFullPathName_U(name, buffer_size, buffer, file_part);
 298                 break;
 299             }
 300             paths = ptr;
 301         }
 302         RtlFreeHeap(ntdll_get_process_heap(), 0, name);
 303     }
 304     else if (RtlDoesFileExists_U(search))
 305     {
 306         len = RtlGetFullPathName_U(search, buffer_size, buffer, file_part);
 307     }
 308
 309     return len;
 310 }
 311
 312 /******************************************************************
 313  *              get_full_path_helper
 314  *
 315  * Helper for RtlGetFullPathName_U
 316  */
 317 static ULONG get_full_path_helper(LPCWSTR name, LPWSTR buffer, ULONG size)
 318 {
 319     ULONG               reqsize, mark = 0;
 320     DOS_PATHNAME_TYPE   type;
 321     LPWSTR              ptr;
 322     UNICODE_STRING*     cd;
 323
 324     reqsize = sizeof(WCHAR); /* '\0' at the end */
 325
 326     RtlAcquirePebLock();
 327     cd = &ntdll_get_process_pmts()->CurrentDirectoryName;
 328
 329     switch (type = RtlDetermineDosPathNameType_U(name))
 330     {
 331     case UNC_PATH:              /* \\foo   */
 332     case DEVICE_PATH:           /* \\.\foo */
 333         if (reqsize <= size) buffer[0] = '\0';
 334         break;
 335
 336     case ABSOLUTE_DRIVE_PATH:   /* c:\foo  */
 337         reqsize += sizeof(WCHAR);
 338         if (reqsize <= size)
 339         {
 340             buffer[0] = toupperW(name[0]);
 341             buffer[1] = '\0';
 342         }
 343         name++;
 344         break;
 345
 346     case RELATIVE_DRIVE_PATH:   /* c:foo   */
 347         if (toupperW(name[0]) != toupperW(cd->Buffer[0]) || cd->Buffer[1] != ':')
 348         {
 349             WCHAR               drive[4];
 350             UNICODE_STRING      var, val;
 351
 352             drive[0] = '=';
 353             drive[1] = name[0];
 354             drive[2] = ':';
 355             drive[3] = '\0';
 356             var.Length = 6;
 357             var.MaximumLength = 8;
 358             var.Buffer = drive;
 359             val.Length = 0;
 360             val.MaximumLength = size;
 361             val.Buffer = buffer;
 362
 363             name += 2;
 364
 365             switch (RtlQueryEnvironmentVariable_U(NULL, &var, &val))
 366             {
 367             case STATUS_SUCCESS:
 368                 /* FIXME: Win2k seems to check that the environment variable actually points
 369                  * to an existing directory. If not, root of the drive is used
 370                  * (this seems also to be the only spot in RtlGetFullPathName that the
 371                  * existence of a part of a path is checked)
 372                  */
 373                 /* fall thru */
 374             case STATUS_BUFFER_TOO_SMALL:
 375                 reqsize += val.Length;
 376                 /* append trailing \\ */
 377                 reqsize += sizeof(WCHAR);
 378                 if (reqsize <= size)
 379                 {
 380                     buffer[reqsize / sizeof(WCHAR) - 2] = '\\';
 381                     buffer[reqsize / sizeof(WCHAR) - 1] = '\0';
 382                 }
 383                 break;
 384             case STATUS_VARIABLE_NOT_FOUND:
 385                 reqsize += 3 * sizeof(WCHAR);
 386                 if (reqsize <= size)
 387                 {
 388                     buffer[0] = drive[1];
 389                     buffer[1] = ':';
 390                     buffer[2] = '\\';
 391                     buffer[3] = '\0';
 392                 }
 393                 break;
 394             default:
 395                 ERR("Unsupported status code\n");
 396                 break;
 397             }
 398             break;
 399         }
 400         name += 2;
 401         /* fall through */
 402
 403     case RELATIVE_PATH:         /* foo     */
 404         reqsize += cd->Length;
 405         if (reqsize <= size)
 406         {
 407             memcpy(buffer, cd->Buffer, cd->Length);
 408             buffer[cd->Length / sizeof(WCHAR)] = 0;
 409         }
 410         if (cd->Buffer[1] != ':')
 411         {
 412             ptr = strchrW(cd->Buffer + 2, '\\');
 413             if (ptr) ptr = strchrW(ptr + 1, '\\');
 414             if (!ptr) ptr = cd->Buffer + strlenW(cd->Buffer);
 415             mark = ptr - cd->Buffer;
 416         }
 417         break;
 418
 419     case ABSOLUTE_PATH:         /* \xxx    */
 420         if (cd->Buffer[1] == ':')
 421         {
 422             reqsize += 2 * sizeof(WCHAR);
 423             if (reqsize <= size)
 424             {
 425                 buffer[0] = cd->Buffer[0];
 426                 buffer[1] = ':';
 427                 buffer[2] = '\0';
 428             }
 429         }
 430         else
 431         {
 432             unsigned    len;
 433
 434             ptr = strchrW(cd->Buffer + 2, '\\');
 435             if (ptr) ptr = strchrW(ptr + 1, '\\');
 436             if (!ptr) ptr = cd->Buffer + strlenW(cd->Buffer);
 437             len = (ptr - cd->Buffer) * sizeof(WCHAR);
 438             reqsize += len;
 439             mark = len / sizeof(WCHAR);
 440             if (reqsize <= size)
 441             {
 442                 memcpy(buffer, cd->Buffer, len);
 443                 buffer[len / sizeof(WCHAR)] = '\0';
 444             }
 445             else
 446                 buffer[0] = '\0';
 447         }
 448         break;
 449
 450     case UNC_DOT_PATH:         /* \\.     */
 451         reqsize += 4 * sizeof(WCHAR);
 452         name += 3;
 453         if (reqsize <= size)
 454         {
 455             buffer[0] = '\\';
 456             buffer[1] = '\\';
 457             buffer[2] = '.';
 458             buffer[3] = '\\';
 459             buffer[4] = '\0';
 460         }
 461         break;
 462
 463     case INVALID_PATH:
 464         reqsize = 0;
 465         goto done;
 466     }
 467
 468     reqsize += strlenW(name) * sizeof(WCHAR);
 469     if (reqsize > size) goto done;
 470
 471     strcatW(buffer, name);
 472
 473     /* convert every / into a \ */
 474     for (ptr = buffer; ptr < buffer + size / sizeof(WCHAR); ptr++)
 475         if (*ptr == '/') *ptr = '\\';
 476
 477     reqsize -= sizeof(WCHAR); /* don't count trailing \0 */
 478
 479     /* mark is non NULL for UNC names, so start path collapsing after server & share name
 480      * otherwise, it's a fully qualified DOS name, so start after the drive designation
 481      */
 482     for (ptr = buffer + (mark ? mark : 2); ptr < buffer + reqsize / sizeof(WCHAR); )
 483     {
 484         WCHAR* p = strchrW(ptr, '\\');
 485         if (!p) break;
 486
 487         p++;
 488         if (p[0] == '.')
 489         {
 490             switch (p[1])
 491             {
 492             case '.':
 493                 switch (p[2])
 494                 {
 495                 case '\\':
 496                     {
 497                         WCHAR*      prev = p - 2;
 498                         while (prev >= buffer + mark && *prev != '\\') prev--;
 499                         /* either collapse \foo\.. into \ or \.. into \ */
 500                         if (prev < buffer + mark) prev = p - 1;
 501                         reqsize -= (p + 2 - prev) * sizeof(WCHAR);
 502                         memmove(prev, p + 2, buffer + reqsize - prev + sizeof(WCHAR));
 503                         p = prev;
 504                     }
 505                     break;
 506                 case '\0':
 507                     reqsize -= 2 * sizeof(WCHAR);
 508                     *p = 0;
 509                     break;
 510                 }
 511                 break;
 512             case '\\':
 513                 reqsize -= 2 * sizeof(WCHAR);
 514                 memmove(ptr, ptr + 2, buffer + reqsize - ptr + sizeof(WCHAR));
 515                 break;
 516             }
 517         }
 518         ptr = p;
 519     }
 520
 521 done:
 522     RtlReleasePebLock();
 523     return reqsize;
 524 }
 525
 526 /******************************************************************
 527  *              RtlGetFullPathName_U  (NTDLL.@)
 528  *
 529  * Returns the number of bytes written to buffer (not including the
 530  * terminating NULL) if the function succeeds, or the required number of bytes
 531  * (including the terminating NULL) if the buffer is too small.
 532  *
 533  * file_part will point to the filename part inside buffer (except if we use
 534  * DOS device name, in which case file_in_buf is NULL)
 535  *
 536  */
 537 DWORD WINAPI RtlGetFullPathName_U(const WCHAR* name, ULONG size, WCHAR* buffer,
 538                                   WCHAR** file_part)
 539 {
 540     WCHAR*      ptr;
 541     DWORD       dosdev;
 542     DWORD       reqsize;
 543
 544     TRACE("(%s %lu %p %p)\n", debugstr_w(name), size, buffer, file_part);
 545
 546     if (!name || !*name) return 0;
 547
 548     if (file_part) *file_part = NULL;
 549
 550     /* check for DOS device name */
 551     dosdev = RtlIsDosDeviceName_U(name);
 552     if (dosdev)
 553     {
 554         DWORD   offset = HIWORD(dosdev) / sizeof(WCHAR); /* get it in WCHARs, not bytes */
 555         DWORD   sz = LOWORD(dosdev); /* in bytes */
 556
 557         if (8 + sz + 2 > size) return sz + 10;
 558         strcpyW(buffer, DeviceRootW);
 559         memmove(buffer + 4, name + offset, sz);
 560         buffer[4 + sz / sizeof(WCHAR)] = '\0';
 561         /* file_part isn't set in this case */
 562         return sz + 8;
 563     }
 564
 565     reqsize = get_full_path_helper(name, buffer, size);
 566     if (reqsize > size)
 567     {
 568         LPWSTR tmp = RtlAllocateHeap(ntdll_get_process_heap(), 0, reqsize);
 569         reqsize = get_full_path_helper(name, tmp, reqsize);
 570         if (reqsize > size)  /* it may have worked the second time */
 571         {
 572             RtlFreeHeap(ntdll_get_process_heap(), 0, tmp);
 573             return reqsize + sizeof(WCHAR);
 574         }
 575         memcpy( buffer, tmp, reqsize + sizeof(WCHAR) );
 576         RtlFreeHeap(ntdll_get_process_heap(), 0, tmp);
 577     }
 578
 579     /* find file part */
 580     if (file_part && (ptr = strrchrW(buffer, '\\')) != NULL && ptr >= buffer + 2 && *++ptr)
 581         *file_part = ptr;
 582     return reqsize;
 583 }
 584
 585 /*************************************************************************
 586  * RtlGetLongestNtPathLength    [NTDLL.@]
 587  *
 588  * Get the longest allowed path length
 589  *
 590  * PARAMS
 591  *  None.
 592  *
 593  * RETURNS
 594  *  The longest allowed path length (277 characters under Win2k).
 595  */
 596 DWORD WINAPI RtlGetLongestNtPathLength(void)
 597 {
 598     return 277;
 599 }
 600
 601 /******************************************************************
 602  *             RtlIsNameLegalDOS8Dot3   (NTDLL.@)
 603  *
 604  * Returns TRUE iff unicode is a valid DOS (8+3) name.
 605  * If the name is valid, oem gets filled with the corresponding OEM string
 606  * spaces is set to TRUE if unicode contains spaces
 607  */
 608 BOOLEAN WINAPI RtlIsNameLegalDOS8Dot3( const UNICODE_STRING *unicode,
 609                                        OEM_STRING *oem, BOOLEAN *spaces )
 610 {
 611     int dot = -1;
 612     unsigned int i;
 613     char buffer[12];
 614     OEM_STRING oem_str;
 615     BOOLEAN got_space = FALSE;
 616
 617     if (!oem)
 618     {
 619         oem_str.Length = sizeof(buffer);
 620         oem_str.MaximumLength = sizeof(buffer);
 621         oem_str.Buffer = buffer;
 622         oem = &oem_str;
 623     }
 624     if (RtlUpcaseUnicodeStringToCountedOemString( oem, unicode, FALSE ) != STATUS_SUCCESS)
 625         return FALSE;
 626
 627     if (oem->Length > 12) return FALSE;
 628
 629     /* a starting . is invalid, except for . and .. */
 630     if (oem->Buffer[0] == '.')
 631     {
 632         if (oem->Length != 1 && (oem->Length != 2 || oem->Buffer[1] != '.')) return FALSE;
 633         if (spaces) *spaces = FALSE;
 634         return TRUE;
 635     }
 636
 637     for (i = 0; i < oem->Length; i++)
 638     {
 639         switch (oem->Buffer[i])
 640         {
 641         case ' ':
 642             /* leading/trailing spaces not allowed */
 643             if (!i || i == oem->Length-1 || oem->Buffer[i+1] == '.') return FALSE;
 644             got_space = TRUE;
 645             break;
 646         case '.':
 647             if (dot != -1) return FALSE;
 648             dot = i;
 649             break;
 650         default:
 651             /* FIXME: check for invalid chars */
 652             break;
 653         }
 654     }
 655     /* check file part is shorter than 8, extension shorter than 3
 656      * dot cannot be last in string
 657      */
 658     if (dot == -1)
 659     {
 660         if (oem->Length > 8) return FALSE;
 661     }
 662     else
 663     {
 664         if (dot > 8 || (oem->Length - dot > 4) || dot == oem->Length - 1) return FALSE;
 665     }
 666     if (spaces) *spaces = got_space;
 667     return TRUE;
 668 }
 669
 670 /******************************************************************
 671  *              RtlGetCurrentDirectory_U (NTDLL.@)
 672  *
 673  */
 674 NTSTATUS WINAPI RtlGetCurrentDirectory_U(ULONG buflen, LPWSTR buf)
 675 {
 676     UNICODE_STRING*     us;
 677     ULONG               len;
 678
 679     TRACE("(%lu %p)\n", buflen, buf);
 680
 681     RtlAcquirePebLock();
 682
 683     us = &ntdll_get_process_pmts()->CurrentDirectoryName;
 684     len = us->Length / sizeof(WCHAR);
 685     if (us->Buffer[len - 1] == '\\' && us->Buffer[len - 2] != ':')
 686         len--;
 687
 688     if (buflen / sizeof(WCHAR) > len)
 689     {
 690         memcpy(buf, us->Buffer, len * sizeof(WCHAR));
 691         buf[len] = '\0';
 692     }
 693     else
 694     {
 695         len++;
 696     }
 697
 698     RtlReleasePebLock();
 699
 700     return len * sizeof(WCHAR);
 701 }
 702
 703 /******************************************************************
 704  *              RtlSetCurrentDirectory_U (NTDLL.@)
 705  *
 706  */
 707 NTSTATUS WINAPI RtlSetCurrentDirectory_U(const UNICODE_STRING* dir)
 708 {
 709     UNICODE_STRING*     curdir;
 710     NTSTATUS            nts = STATUS_SUCCESS;
 711     ULONG               size;
 712     PWSTR               buf = NULL;
 713
 714     TRACE("(%s)\n", debugstr_w(dir->Buffer));
 715
 716     RtlAcquirePebLock();
 717
 718     curdir = &ntdll_get_process_pmts()->CurrentDirectoryName;
 719     size = curdir->MaximumLength;
 720
 721     buf = RtlAllocateHeap(ntdll_get_process_heap(), 0, size);
 722     if (buf == NULL)
 723     {
 724         nts = STATUS_NO_MEMORY;
 725         goto out;
 726     }
 727
 728     size = RtlGetFullPathName_U(dir->Buffer, size, buf, 0);
 729     if (!size)
 730     {
 731         nts = STATUS_OBJECT_NAME_INVALID;
 732         goto out;
 733     }
 734
 735     switch (RtlDetermineDosPathNameType_U(buf))
 736     {
 737     case ABSOLUTE_DRIVE_PATH:
 738     case UNC_PATH:
 739         break;
 740     default:
 741         FIXME("Don't support those cases yes\n");
 742         nts = STATUS_NOT_IMPLEMENTED;
 743         goto out;
 744     }
 745
 746     /* FIXME: should check that the directory actually exists,
 747      * and fill CurrentDirectoryHandle accordingly
 748      */
 749
 750     /* append trailing \ if missing */
 751     if (buf[size / sizeof(WCHAR) - 1] != '\\')
 752     {
 753         buf[size / sizeof(WCHAR)] = '\\';
 754         buf[size / sizeof(WCHAR) + 1] = '\0';
 755         size += sizeof(WCHAR);
 756     }
 757
 758     memmove(curdir->Buffer, buf, size + sizeof(WCHAR));
 759     curdir->Length = size;
 760
 761 #if 0
 762     if (curdir->Buffer[1] == ':')
 763     {
 764         UNICODE_STRING  env;
 765         WCHAR           var[4];
 766
 767         var[0] = '=';
 768         var[1] = curdir->Buffer[0];
 769         var[2] = ':';
 770         var[3] = 0;
 771         env.Length = 3 * sizeof(WCHAR);
 772         env.MaximumLength = 4 * sizeof(WCHAR);
 773         env.Buffer = var;
 774
 775         RtlSetEnvironmentVariable(NULL, &env, curdir);
 776     }
 777 #endif
 778
 779  out:
 780     if (buf) RtlFreeHeap(ntdll_get_process_heap(), 0, buf);
 781
 782     RtlReleasePebLock();
 783
 784     return nts;
 785 }