src/win32/posix_w32.c

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7 #include "../posix.h"
   8 #include "../fileops.h"
   9 #include "path.h"
  10 #include "path_w32.h"
  11 #include "utf-conv.h"
  12 #include "repository.h"
  13 #include "reparse.h"
  14 #include "global.h"
  15 #include "buffer.h"
  16 #include <errno.h>
  17 #include <io.h>
  18 #include <fcntl.h>
  19 #include <ws2tcpip.h>
  20
  21 #ifndef FILE_NAME_NORMALIZED
  22 # define FILE_NAME_NORMALIZED 0
  23 #endif
  24
  25 #ifndef IO_REPARSE_TAG_SYMLINK
  26 #define IO_REPARSE_TAG_SYMLINK (0xA000000CL)
  27 #endif
  28
  29 /* Options which we always provide to _wopen.
  30  *
  31  * _O_BINARY - Raw access; no translation of CR or LF characters
  32  * _O_NOINHERIT - Do not mark the created handle as inheritable by child processes.
  33  *    The Windows default is 'not inheritable', but the CRT's default (following
  34  *    POSIX convention) is 'inheritable'. We have no desire for our handles to be
  35  *    inheritable on Windows, so specify the flag to get default behavior back. */
  36 #define STANDARD_OPEN_FLAGS (_O_BINARY | _O_NOINHERIT)
  37
  38 /* Allowable mode bits on Win32.  Using mode bits that are not supported on
  39  * Win32 (eg S_IRWXU) is generally ignored, but Wine warns loudly about it
  40  * so we simply remove them.
  41  */
  42 #define WIN32_MODE_MASK (_S_IREAD | _S_IWRITE)
  43
  44 /* GetFinalPathNameByHandleW signature */
  45 typedef DWORD(WINAPI *PFGetFinalPathNameByHandleW)(HANDLE, LPWSTR, DWORD, DWORD);
  46
  47 /**
  48  * Truncate or extend file.
  49  *
  50  * We now take a "git_off_t" rather than "long" because
  51  * files may be longer than 2Gb.
  52  */
  53 int p_ftruncate(int fd, git_off_t size)
  54 {
  55         if (size < 0) {
  56                 errno = EINVAL;
  57                 return -1;
  58         }
  59
  60 #if !defined(__MINGW32__) || defined(MINGW_HAS_SECURE_API)
  61         return ((_chsize_s(fd, size) == 0) ? 0 : -1);
  62 #else
  63         /* TODO MINGW32 Find a replacement for _chsize() that handles big files. */
  64         if (size > INT32_MAX) {
  65                 errno = EFBIG;
  66                 return -1;
  67         }
  68         return _chsize(fd, (long)size);
  69 #endif
  70 }
  71
  72 int p_mkdir(const char *path, mode_t mode)
  73 {
  74         git_win32_path buf;
  75
  76         GIT_UNUSED(mode);
  77
  78         if (git_win32_path_from_utf8(buf, path) < 0)
  79                 return -1;
  80
  81         return _wmkdir(buf);
  82 }
  83
  84 int p_link(const char *old, const char *new)
  85 {
  86         GIT_UNUSED(old);
  87         GIT_UNUSED(new);
  88         errno = ENOSYS;
  89         return -1;
  90 }
  91
  92 int p_unlink(const char *path)
  93 {
  94         git_win32_path buf;
  95         int error;
  96
  97         if (git_win32_path_from_utf8(buf, path) < 0)
  98                 return -1;
  99
 100         error = _wunlink(buf);
 101
 102         /* If the file could not be deleted because it was
 103          * read-only, clear the bit and try again */
 104         if (error == -1 && errno == EACCES) {
 105                 _wchmod(buf, 0666);
 106                 error = _wunlink(buf);
 107         }
 108
 109         return error;
 110 }
 111
 112 int p_fsync(int fd)
 113 {
 114         HANDLE fh = (HANDLE)_get_osfhandle(fd);
 115
 116         if (fh == INVALID_HANDLE_VALUE) {
 117                 errno = EBADF;
 118                 return -1;
 119         }
 120
 121         if (!FlushFileBuffers(fh)) {
 122                 DWORD code = GetLastError();
 123
 124                 if (code == ERROR_INVALID_HANDLE)
 125                         errno = EINVAL;
 126                 else
 127                         errno = EIO;
 128
 129                 return -1;
 130         }
 131
 132         return 0;
 133 }
 134
 135 #define WIN32_IS_WSEP(CH) ((CH) == L'/' || (CH) == L'\\')
 136
 137 static int lstat_w(
 138         wchar_t *path,
 139         struct stat *buf,
 140         bool posix_enotdir)
 141 {
 142         WIN32_FILE_ATTRIBUTE_DATA fdata;
 143
 144         if (GetFileAttributesExW(path, GetFileExInfoStandard, &fdata)) {
 145                 if (!buf)
 146                         return 0;
 147
 148                 return git_win32__file_attribute_to_stat(buf, &fdata, path);
 149         }
 150
 151         switch (GetLastError()) {
 152         case ERROR_ACCESS_DENIED:
 153                 errno = EACCES;
 154                 break;
 155         default:
 156                 errno = ENOENT;
 157                 break;
 158         }
 159
 160         /* To match POSIX behavior, set ENOTDIR when any of the folders in the
 161          * file path is a regular file, otherwise set ENOENT.
 162          */
 163         if (errno == ENOENT && posix_enotdir) {
 164                 size_t path_len = wcslen(path);
 165
 166                 /* scan up path until we find an existing item */
 167                 while (1) {
 168                         DWORD attrs;
 169
 170                         /* remove last directory component */
 171                         for (path_len--; path_len > 0 && !WIN32_IS_WSEP(path[path_len]); path_len--);
 172
 173                         if (path_len <= 0)
 174                                 break;
 175
 176                         path[path_len] = L'\0';
 177                         attrs = GetFileAttributesW(path);
 178
 179                         if (attrs != INVALID_FILE_ATTRIBUTES) {
 180                                 if (!(attrs & FILE_ATTRIBUTE_DIRECTORY))
 181                                         errno = ENOTDIR;
 182                                 break;
 183                         }
 184                 }
 185         }
 186
 187         return -1;
 188 }
 189
 190 static int do_lstat(const char *path, struct stat *buf, bool posixly_correct)
 191 {
 192         git_win32_path path_w;
 193         int len;
 194
 195         if ((len = git_win32_path_from_utf8(path_w, path)) < 0)
 196                 return -1;
 197
 198         git_win32__path_trim_end(path_w, len);
 199
 200         return lstat_w(path_w, buf, posixly_correct);
 201 }
 202
 203 int p_lstat(const char *filename, struct stat *buf)
 204 {
 205         return do_lstat(filename, buf, false);
 206 }
 207
 208 int p_lstat_posixly(const char *filename, struct stat *buf)
 209 {
 210         return do_lstat(filename, buf, true);
 211 }
 212
 213 int p_utimes(const char *filename, const struct p_timeval times[2])
 214 {
 215         int fd, error;
 216
 217         if ((fd = p_open(filename, O_RDWR)) < 0)
 218                 return fd;
 219
 220         error = p_futimes(fd, times);
 221
 222         close(fd);
 223         return error;
 224 }
 225
 226 int p_futimes(int fd, const struct p_timeval times[2])
 227 {
 228         HANDLE handle;
 229         FILETIME atime = {0}, mtime = {0};
 230
 231         if (times == NULL) {
 232                 SYSTEMTIME st;
 233
 234                 GetSystemTime(&st);
 235                 SystemTimeToFileTime(&st, &atime);
 236                 SystemTimeToFileTime(&st, &mtime);
 237         } else {
 238                 git_win32__timeval_to_filetime(&atime, times[0]);
 239                 git_win32__timeval_to_filetime(&mtime, times[1]);
 240         }
 241
 242         if ((handle = (HANDLE)_get_osfhandle(fd)) == INVALID_HANDLE_VALUE)
 243                 return -1;
 244
 245         if (SetFileTime(handle, NULL, &atime, &mtime) == 0)
 246                 return -1;
 247
 248         return 0;
 249 }
 250
 251 int p_readlink(const char *path, char *buf, size_t bufsiz)
 252 {
 253         git_win32_path path_w, target_w;
 254         git_win32_utf8_path target;
 255         int len;
 256
 257         /* readlink(2) does not NULL-terminate the string written
 258          * to the target buffer. Furthermore, the target buffer need
 259          * not be large enough to hold the entire result. A truncated
 260          * result should be written in this case. Since this truncation
 261          * could occur in the middle of the encoding of a code point,
 262          * we need to buffer the result on the stack. */
 263
 264         if (git_win32_path_from_utf8(path_w, path) < 0 ||
 265                 git_win32_path_readlink_w(target_w, path_w) < 0 ||
 266                 (len = git_win32_path_to_utf8(target, target_w)) < 0)
 267                 return -1;
 268
 269         bufsiz = min((size_t)len, bufsiz);
 270         memcpy(buf, target, bufsiz);
 271
 272         return (int)bufsiz;
 273 }
 274
 275 int p_symlink(const char *old, const char *new)
 276 {
 277         /* Real symlinks on NTFS require admin privileges. Until this changes,
 278          * libgit2 just creates a text file with the link target in the contents.
 279          */
 280         return git_futils_fake_symlink(old, new);
 281 }
 282
 283 int p_open(const char *path, int flags, ...)
 284 {
 285         git_win32_path buf;
 286         mode_t mode = 0;
 287
 288         if (git_win32_path_from_utf8(buf, path) < 0)
 289                 return -1;
 290
 291         if (flags & O_CREAT) {
 292                 va_list arg_list;
 293
 294                 va_start(arg_list, flags);
 295                 mode = (mode_t)va_arg(arg_list, int);
 296                 va_end(arg_list);
 297         }
 298
 299         return _wopen(buf, flags | STANDARD_OPEN_FLAGS, mode & WIN32_MODE_MASK);
 300 }
 301
 302 int p_creat(const char *path, mode_t mode)
 303 {
 304         git_win32_path buf;
 305
 306         if (git_win32_path_from_utf8(buf, path) < 0)
 307                 return -1;
 308
 309         return _wopen(buf,
 310                 _O_WRONLY | _O_CREAT | _O_TRUNC | STANDARD_OPEN_FLAGS,
 311                 mode & WIN32_MODE_MASK);
 312 }
 313
 314 int p_getcwd(char *buffer_out, size_t size)
 315 {
 316         git_win32_path buf;
 317         wchar_t *cwd = _wgetcwd(buf, GIT_WIN_PATH_UTF16);
 318
 319         if (!cwd)
 320                 return -1;
 321
 322         /* Convert the working directory back to UTF-8 */
 323         if (git__utf16_to_8(buffer_out, size, cwd) < 0) {
 324                 DWORD code = GetLastError();
 325
 326                 if (code == ERROR_INSUFFICIENT_BUFFER)
 327                         errno = ERANGE;
 328                 else
 329                         errno = EINVAL;
 330
 331                 return -1;
 332         }
 333
 334         return 0;
 335 }
 336
 337 /*
 338  * Returns the address of the GetFinalPathNameByHandleW function.
 339  * This function is available on Windows Vista and higher.
 340  */
 341 static PFGetFinalPathNameByHandleW get_fpnbyhandle(void)
 342 {
 343         static PFGetFinalPathNameByHandleW pFunc = NULL;
 344         PFGetFinalPathNameByHandleW toReturn = pFunc;
 345
 346         if (!toReturn) {
 347                 HMODULE hModule = GetModuleHandleW(L"kernel32");
 348
 349                 if (hModule)
 350                         toReturn = (PFGetFinalPathNameByHandleW)GetProcAddress(hModule, "GetFinalPathNameByHandleW");
 351
 352                 pFunc = toReturn;
 353         }
 354
 355         assert(toReturn);
 356
 357         return toReturn;
 358 }
 359
 360 static int getfinalpath_w(
 361         git_win32_path dest,
 362         const wchar_t *path)
 363 {
 364         PFGetFinalPathNameByHandleW pgfp = get_fpnbyhandle();
 365         HANDLE hFile;
 366         DWORD dwChars;
 367
 368         if (!pgfp)
 369                 return -1;
 370
 371         /* Use FILE_FLAG_BACKUP_SEMANTICS so we can open a directory. Do not
 372         * specify FILE_FLAG_OPEN_REPARSE_POINT; we want to open a handle to the
 373         * target of the link. */
 374         hFile = CreateFileW(path, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_DELETE,
 375                 NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
 376
 377         if (INVALID_HANDLE_VALUE == hFile)
 378                 return -1;
 379
 380         /* Call GetFinalPathNameByHandle */
 381         dwChars = pgfp(hFile, dest, GIT_WIN_PATH_UTF16, FILE_NAME_NORMALIZED);
 382         CloseHandle(hFile);
 383
 384         if (!dwChars || dwChars >= GIT_WIN_PATH_UTF16)
 385                 return -1;
 386
 387         /* The path may be delivered to us with a prefix; canonicalize */
 388         return (int)git_win32__canonicalize_path(dest, dwChars);
 389 }
 390
 391 static int follow_and_lstat_link(git_win32_path path, struct stat* buf)
 392 {
 393         git_win32_path target_w;
 394
 395         if (getfinalpath_w(target_w, path) < 0)
 396                 return -1;
 397
 398         return lstat_w(target_w, buf, false);
 399 }
 400
 401 int p_fstat(int fd, struct stat *buf)
 402 {
 403         BY_HANDLE_FILE_INFORMATION fhInfo;
 404
 405         HANDLE fh = (HANDLE)_get_osfhandle(fd);
 406
 407         if (fh == INVALID_HANDLE_VALUE ||
 408                 !GetFileInformationByHandle(fh, &fhInfo)) {
 409                 errno = EBADF;
 410                 return -1;
 411         }
 412
 413         git_win32__file_information_to_stat(buf, &fhInfo);
 414         return 0;
 415 }
 416
 417 int p_stat(const char* path, struct stat* buf)
 418 {
 419         git_win32_path path_w;
 420         int len;
 421
 422         if ((len = git_win32_path_from_utf8(path_w, path)) < 0 ||
 423                 lstat_w(path_w, buf, false) < 0)
 424                 return -1;
 425
 426         /* The item is a symbolic link or mount point. No need to iterate
 427          * to follow multiple links; use GetFinalPathNameFromHandle. */
 428         if (S_ISLNK(buf->st_mode))
 429                 return follow_and_lstat_link(path_w, buf);
 430
 431         return 0;
 432 }
 433
 434 int p_chdir(const char* path)
 435 {
 436         git_win32_path buf;
 437
 438         if (git_win32_path_from_utf8(buf, path) < 0)
 439                 return -1;
 440
 441         return _wchdir(buf);
 442 }
 443
 444 int p_chmod(const char* path, mode_t mode)
 445 {
 446         git_win32_path buf;
 447
 448         if (git_win32_path_from_utf8(buf, path) < 0)
 449                 return -1;
 450
 451         return _wchmod(buf, mode);
 452 }
 453
 454 int p_rmdir(const char* path)
 455 {
 456         git_win32_path buf;
 457         int error;
 458
 459         if (git_win32_path_from_utf8(buf, path) < 0)
 460                 return -1;
 461
 462         error = _wrmdir(buf);
 463
 464         if (error == -1) {
 465                 switch (GetLastError()) {
 466                         /* _wrmdir() is documented to return EACCES if "A program has an open
 467                          * handle to the directory."  This sounds like what everybody else calls
 468                          * EBUSY.  Let's convert appropriate error codes.
 469                          */
 470                         case ERROR_SHARING_VIOLATION:
 471                                 errno = EBUSY;
 472                                 break;
 473
 474                         /* This error can be returned when trying to rmdir an extant file. */
 475                         case ERROR_DIRECTORY:
 476                                 errno = ENOTDIR;
 477                                 break;
 478                 }
 479         }
 480
 481         return error;
 482 }
 483
 484 char *p_realpath(const char *orig_path, char *buffer)
 485 {
 486         git_win32_path orig_path_w, buffer_w;
 487
 488         if (git_win32_path_from_utf8(orig_path_w, orig_path) < 0)
 489                 return NULL;
 490
 491         /* Note that if the path provided is a relative path, then the current directory
 492          * is used to resolve the path -- which is a concurrency issue because the current
 493          * directory is a process-wide variable. */
 494         if (!GetFullPathNameW(orig_path_w, GIT_WIN_PATH_UTF16, buffer_w, NULL)) {
 495                 if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
 496                         errno = ENAMETOOLONG;
 497                 else
 498                         errno = EINVAL;
 499
 500                 return NULL;
 501         }
 502
 503         /* The path must exist. */
 504         if (GetFileAttributesW(buffer_w) == INVALID_FILE_ATTRIBUTES) {
 505                 errno = ENOENT;
 506                 return NULL;
 507         }
 508
 509         if (!buffer && !(buffer = git__malloc(GIT_WIN_PATH_UTF8))) {
 510                 errno = ENOMEM;
 511                 return NULL;
 512         }
 513
 514         /* Convert the path to UTF-8. If the caller provided a buffer, then it
 515          * is assumed to be GIT_WIN_PATH_UTF8 characters in size. If it isn't,
 516          * then we may overflow. */
 517         if (git_win32_path_to_utf8(buffer, buffer_w) < 0)
 518                 return NULL;
 519
 520         git_path_mkposix(buffer);
 521
 522         return buffer;
 523 }
 524
 525 int p_vsnprintf(char *buffer, size_t count, const char *format, va_list argptr)
 526 {
 527 #if defined(_MSC_VER)
 528         int len;
 529
 530         if (count == 0)
 531                 return _vscprintf(format, argptr);
 532
 533         #if _MSC_VER >= 1500
 534         len = _vsnprintf_s(buffer, count, _TRUNCATE, format, argptr);
 535         #else
 536         len = _vsnprintf(buffer, count, format, argptr);
 537         #endif
 538
 539         if (len < 0)
 540                 return _vscprintf(format, argptr);
 541
 542         return len;
 543 #else /* MinGW */
 544         return vsnprintf(buffer, count, format, argptr);
 545 #endif
 546 }
 547
 548 int p_snprintf(char *buffer, size_t count, const char *format, ...)
 549 {
 550         va_list va;
 551         int r;
 552
 553         va_start(va, format);
 554         r = p_vsnprintf(buffer, count, format, va);
 555         va_end(va);
 556
 557         return r;
 558 }
 559
 560 /* TODO: wut? */
 561 int p_mkstemp(char *tmp_path)
 562 {
 563 #if defined(_MSC_VER) && _MSC_VER >= 1500
 564         if (_mktemp_s(tmp_path, strlen(tmp_path) + 1) != 0)
 565                 return -1;
 566 #else
 567         if (_mktemp(tmp_path) == NULL)
 568                 return -1;
 569 #endif
 570
 571         return p_open(tmp_path, O_RDWR | O_CREAT | O_EXCL, 0744); //-V536
 572 }
 573
 574 int p_access(const char* path, mode_t mode)
 575 {
 576         git_win32_path buf;
 577
 578         if (git_win32_path_from_utf8(buf, path) < 0)
 579                 return -1;
 580
 581         return _waccess(buf, mode & WIN32_MODE_MASK);
 582 }
 583
 584 static int ensure_writable(wchar_t *fpath)
 585 {
 586         DWORD attrs;
 587
 588         attrs = GetFileAttributesW(fpath);
 589         if (attrs == INVALID_FILE_ATTRIBUTES) {
 590                 if (GetLastError() == ERROR_FILE_NOT_FOUND)
 591                         return 0;
 592
 593                 giterr_set(GITERR_OS, "failed to get attributes");
 594                 return -1;
 595         }
 596
 597         if (!(attrs & FILE_ATTRIBUTE_READONLY))
 598                 return 0;
 599
 600         attrs &= ~FILE_ATTRIBUTE_READONLY;
 601         if (!SetFileAttributesW(fpath, attrs)) {
 602                 giterr_set(GITERR_OS, "failed to set attributes");
 603                 return -1;
 604         }
 605
 606         return 0;
 607 }
 608
 609 int p_rename(const char *from, const char *to)
 610 {
 611         git_win32_path wfrom;
 612         git_win32_path wto;
 613         int rename_tries;
 614         int rename_succeeded;
 615         int error;
 616
 617         if (git_win32_path_from_utf8(wfrom, from) < 0 ||
 618                 git_win32_path_from_utf8(wto, to) < 0)
 619                 return -1;
 620
 621         /* wait up to 50ms if file is locked by another thread or process */
 622         rename_tries = 0;
 623         rename_succeeded = 0;
 624         while (rename_tries < 10) {
 625                 if (ensure_writable(wto) == 0 &&
 626                     MoveFileExW(wfrom, wto, MOVEFILE_REPLACE_EXISTING | MOVEFILE_COPY_ALLOWED) != 0) {
 627                         rename_succeeded = 1;
 628                         break;
 629                 }
 630
 631                 error = GetLastError();
 632                 if (error == ERROR_SHARING_VIOLATION || error == ERROR_ACCESS_DENIED) {
 633                         Sleep(5);
 634                         rename_tries++;
 635                 } else
 636                         break;
 637         }
 638
 639         return rename_succeeded ? 0 : -1;
 640 }
 641
 642 int p_recv(GIT_SOCKET socket, void *buffer, size_t length, int flags)
 643 {
 644         if ((size_t)((int)length) != length)
 645                 return -1; /* giterr_set will be done by caller */
 646
 647         return recv(socket, buffer, (int)length, flags);
 648 }
 649
 650 int p_send(GIT_SOCKET socket, const void *buffer, size_t length, int flags)
 651 {
 652         if ((size_t)((int)length) != length)
 653                 return -1; /* giterr_set will be done by caller */
 654
 655         return send(socket, buffer, (int)length, flags);
 656 }
 657
 658 /**
 659  * Borrowed from http://old.nabble.com/Porting-localtime_r-and-gmtime_r-td15282276.html
 660  * On Win32, `gmtime_r` doesn't exist but `gmtime` is threadsafe, so we can use that
 661  */
 662 struct tm *
 663 p_localtime_r (const time_t *timer, struct tm *result)
 664 {
 665         struct tm *local_result;
 666         local_result = localtime (timer);
 667
 668         if (local_result == NULL || result == NULL)
 669                 return NULL;
 670
 671         memcpy (result, local_result, sizeof (struct tm));
 672         return result;
 673 }
 674 struct tm *
 675 p_gmtime_r (const time_t *timer, struct tm *result)
 676 {
 677         struct tm *local_result;
 678         local_result = gmtime (timer);
 679
 680         if (local_result == NULL || result == NULL)
 681                 return NULL;
 682
 683         memcpy (result, local_result, sizeof (struct tm));
 684         return result;
 685 }
 686
 687 int p_inet_pton(int af, const char *src, void *dst)
 688 {
 689         struct sockaddr_storage sin;
 690         void *addr;
 691         int sin_len = sizeof(struct sockaddr_storage), addr_len;
 692         int error = 0;
 693
 694         if (af == AF_INET) {
 695                 addr = &((struct sockaddr_in *)&sin)->sin_addr;
 696                 addr_len = sizeof(struct in_addr);
 697         } else if (af == AF_INET6) {
 698                 addr = &((struct sockaddr_in6 *)&sin)->sin6_addr;
 699                 addr_len = sizeof(struct in6_addr);
 700         } else {
 701                 errno = EAFNOSUPPORT;
 702                 return -1;
 703         }
 704
 705         if ((error = WSAStringToAddressA((LPSTR)src, af, NULL, (LPSOCKADDR)&sin, &sin_len)) == 0) {
 706                 memcpy(dst, addr, addr_len);
 707                 return 1;
 708         }
 709
 710         switch(WSAGetLastError()) {
 711         case WSAEINVAL:
 712                 return 0;
 713         case WSAEFAULT:
 714                 errno = ENOSPC;
 715                 return -1;
 716         case WSA_NOT_ENOUGH_MEMORY:
 717                 errno = ENOMEM;
 718                 return -1;
 719         }
 720
 721         errno = EINVAL;
 722         return -1;
 723 }