compat/mingw.c

   1 #include "../git-compat-util.h"
   2 #include "win32.h"
   3 #include <conio.h>
   4 #include "../strbuf.h"
   5 #include "../run-command.h"
   6
   7 static const int delay[] = { 0, 1, 10, 20, 40 };
   8
   9 int err_win_to_posix(DWORD winerr)
  10 {
  11         int error = ENOSYS;
  12         switch(winerr) {
  13         case ERROR_ACCESS_DENIED: error = EACCES; break;
  14         case ERROR_ACCOUNT_DISABLED: error = EACCES; break;
  15         case ERROR_ACCOUNT_RESTRICTION: error = EACCES; break;
  16         case ERROR_ALREADY_ASSIGNED: error = EBUSY; break;
  17         case ERROR_ALREADY_EXISTS: error = EEXIST; break;
  18         case ERROR_ARITHMETIC_OVERFLOW: error = ERANGE; break;
  19         case ERROR_BAD_COMMAND: error = EIO; break;
  20         case ERROR_BAD_DEVICE: error = ENODEV; break;
  21         case ERROR_BAD_DRIVER_LEVEL: error = ENXIO; break;
  22         case ERROR_BAD_EXE_FORMAT: error = ENOEXEC; break;
  23         case ERROR_BAD_FORMAT: error = ENOEXEC; break;
  24         case ERROR_BAD_LENGTH: error = EINVAL; break;
  25         case ERROR_BAD_PATHNAME: error = ENOENT; break;
  26         case ERROR_BAD_PIPE: error = EPIPE; break;
  27         case ERROR_BAD_UNIT: error = ENODEV; break;
  28         case ERROR_BAD_USERNAME: error = EINVAL; break;
  29         case ERROR_BROKEN_PIPE: error = EPIPE; break;
  30         case ERROR_BUFFER_OVERFLOW: error = ENAMETOOLONG; break;
  31         case ERROR_BUSY: error = EBUSY; break;
  32         case ERROR_BUSY_DRIVE: error = EBUSY; break;
  33         case ERROR_CALL_NOT_IMPLEMENTED: error = ENOSYS; break;
  34         case ERROR_CANNOT_MAKE: error = EACCES; break;
  35         case ERROR_CANTOPEN: error = EIO; break;
  36         case ERROR_CANTREAD: error = EIO; break;
  37         case ERROR_CANTWRITE: error = EIO; break;
  38         case ERROR_CRC: error = EIO; break;
  39         case ERROR_CURRENT_DIRECTORY: error = EACCES; break;
  40         case ERROR_DEVICE_IN_USE: error = EBUSY; break;
  41         case ERROR_DEV_NOT_EXIST: error = ENODEV; break;
  42         case ERROR_DIRECTORY: error = EINVAL; break;
  43         case ERROR_DIR_NOT_EMPTY: error = ENOTEMPTY; break;
  44         case ERROR_DISK_CHANGE: error = EIO; break;
  45         case ERROR_DISK_FULL: error = ENOSPC; break;
  46         case ERROR_DRIVE_LOCKED: error = EBUSY; break;
  47         case ERROR_ENVVAR_NOT_FOUND: error = EINVAL; break;
  48         case ERROR_EXE_MARKED_INVALID: error = ENOEXEC; break;
  49         case ERROR_FILENAME_EXCED_RANGE: error = ENAMETOOLONG; break;
  50         case ERROR_FILE_EXISTS: error = EEXIST; break;
  51         case ERROR_FILE_INVALID: error = ENODEV; break;
  52         case ERROR_FILE_NOT_FOUND: error = ENOENT; break;
  53         case ERROR_GEN_FAILURE: error = EIO; break;
  54         case ERROR_HANDLE_DISK_FULL: error = ENOSPC; break;
  55         case ERROR_INSUFFICIENT_BUFFER: error = ENOMEM; break;
  56         case ERROR_INVALID_ACCESS: error = EACCES; break;
  57         case ERROR_INVALID_ADDRESS: error = EFAULT; break;
  58         case ERROR_INVALID_BLOCK: error = EFAULT; break;
  59         case ERROR_INVALID_DATA: error = EINVAL; break;
  60         case ERROR_INVALID_DRIVE: error = ENODEV; break;
  61         case ERROR_INVALID_EXE_SIGNATURE: error = ENOEXEC; break;
  62         case ERROR_INVALID_FLAGS: error = EINVAL; break;
  63         case ERROR_INVALID_FUNCTION: error = ENOSYS; break;
  64         case ERROR_INVALID_HANDLE: error = EBADF; break;
  65         case ERROR_INVALID_LOGON_HOURS: error = EACCES; break;
  66         case ERROR_INVALID_NAME: error = EINVAL; break;
  67         case ERROR_INVALID_OWNER: error = EINVAL; break;
  68         case ERROR_INVALID_PARAMETER: error = EINVAL; break;
  69         case ERROR_INVALID_PASSWORD: error = EPERM; break;
  70         case ERROR_INVALID_PRIMARY_GROUP: error = EINVAL; break;
  71         case ERROR_INVALID_SIGNAL_NUMBER: error = EINVAL; break;
  72         case ERROR_INVALID_TARGET_HANDLE: error = EIO; break;
  73         case ERROR_INVALID_WORKSTATION: error = EACCES; break;
  74         case ERROR_IO_DEVICE: error = EIO; break;
  75         case ERROR_IO_INCOMPLETE: error = EINTR; break;
  76         case ERROR_LOCKED: error = EBUSY; break;
  77         case ERROR_LOCK_VIOLATION: error = EACCES; break;
  78         case ERROR_LOGON_FAILURE: error = EACCES; break;
  79         case ERROR_MAPPED_ALIGNMENT: error = EINVAL; break;
  80         case ERROR_META_EXPANSION_TOO_LONG: error = E2BIG; break;
  81         case ERROR_MORE_DATA: error = EPIPE; break;
  82         case ERROR_NEGATIVE_SEEK: error = ESPIPE; break;
  83         case ERROR_NOACCESS: error = EFAULT; break;
  84         case ERROR_NONE_MAPPED: error = EINVAL; break;
  85         case ERROR_NOT_ENOUGH_MEMORY: error = ENOMEM; break;
  86         case ERROR_NOT_READY: error = EAGAIN; break;
  87         case ERROR_NOT_SAME_DEVICE: error = EXDEV; break;
  88         case ERROR_NO_DATA: error = EPIPE; break;
  89         case ERROR_NO_MORE_SEARCH_HANDLES: error = EIO; break;
  90         case ERROR_NO_PROC_SLOTS: error = EAGAIN; break;
  91         case ERROR_NO_SUCH_PRIVILEGE: error = EACCES; break;
  92         case ERROR_OPEN_FAILED: error = EIO; break;
  93         case ERROR_OPEN_FILES: error = EBUSY; break;
  94         case ERROR_OPERATION_ABORTED: error = EINTR; break;
  95         case ERROR_OUTOFMEMORY: error = ENOMEM; break;
  96         case ERROR_PASSWORD_EXPIRED: error = EACCES; break;
  97         case ERROR_PATH_BUSY: error = EBUSY; break;
  98         case ERROR_PATH_NOT_FOUND: error = ENOENT; break;
  99         case ERROR_PIPE_BUSY: error = EBUSY; break;
 100         case ERROR_PIPE_CONNECTED: error = EPIPE; break;
 101         case ERROR_PIPE_LISTENING: error = EPIPE; break;
 102         case ERROR_PIPE_NOT_CONNECTED: error = EPIPE; break;
 103         case ERROR_PRIVILEGE_NOT_HELD: error = EACCES; break;
 104         case ERROR_READ_FAULT: error = EIO; break;
 105         case ERROR_SEEK: error = EIO; break;
 106         case ERROR_SEEK_ON_DEVICE: error = ESPIPE; break;
 107         case ERROR_SHARING_BUFFER_EXCEEDED: error = ENFILE; break;
 108         case ERROR_SHARING_VIOLATION: error = EACCES; break;
 109         case ERROR_STACK_OVERFLOW: error = ENOMEM; break;
 110         case ERROR_SWAPERROR: error = ENOENT; break;
 111         case ERROR_TOO_MANY_MODULES: error = EMFILE; break;
 112         case ERROR_TOO_MANY_OPEN_FILES: error = EMFILE; break;
 113         case ERROR_UNRECOGNIZED_MEDIA: error = ENXIO; break;
 114         case ERROR_UNRECOGNIZED_VOLUME: error = ENODEV; break;
 115         case ERROR_WAIT_NO_CHILDREN: error = ECHILD; break;
 116         case ERROR_WRITE_FAULT: error = EIO; break;
 117         case ERROR_WRITE_PROTECT: error = EROFS; break;
 118         }
 119         return error;
 120 }
 121
 122 static inline int is_file_in_use_error(DWORD errcode)
 123 {
 124         switch (errcode) {
 125         case ERROR_SHARING_VIOLATION:
 126         case ERROR_ACCESS_DENIED:
 127                 return 1;
 128         }
 129
 130         return 0;
 131 }
 132
 133 static int read_yes_no_answer(void)
 134 {
 135         char answer[1024];
 136
 137         if (fgets(answer, sizeof(answer), stdin)) {
 138                 size_t answer_len = strlen(answer);
 139                 int got_full_line = 0, c;
 140
 141                 /* remove the newline */
 142                 if (answer_len >= 2 && answer[answer_len-2] == '\r') {
 143                         answer[answer_len-2] = '\0';
 144                         got_full_line = 1;
 145                 } else if (answer_len >= 1 && answer[answer_len-1] == '\n') {
 146                         answer[answer_len-1] = '\0';
 147                         got_full_line = 1;
 148                 }
 149                 /* flush the buffer in case we did not get the full line */
 150                 if (!got_full_line)
 151                         while ((c = getchar()) != EOF && c != '\n')
 152                                 ;
 153         } else
 154                 /* we could not read, return the
 155                  * default answer which is no */
 156                 return 0;
 157
 158         if (tolower(answer[0]) == 'y' && !answer[1])
 159                 return 1;
 160         if (!strncasecmp(answer, "yes", sizeof(answer)))
 161                 return 1;
 162         if (tolower(answer[0]) == 'n' && !answer[1])
 163                 return 0;
 164         if (!strncasecmp(answer, "no", sizeof(answer)))
 165                 return 0;
 166
 167         /* did not find an answer we understand */
 168         return -1;
 169 }
 170
 171 static int ask_yes_no_if_possible(const char *format, ...)
 172 {
 173         char question[4096];
 174         const char *retry_hook[] = { NULL, NULL, NULL };
 175         va_list args;
 176
 177         va_start(args, format);
 178         vsnprintf(question, sizeof(question), format, args);
 179         va_end(args);
 180
 181         if ((retry_hook[0] = mingw_getenv("GIT_ASK_YESNO"))) {
 182                 retry_hook[1] = question;
 183                 return !run_command_v_opt(retry_hook, 0);
 184         }
 185
 186         if (!isatty(_fileno(stdin)) || !isatty(_fileno(stderr)))
 187                 return 0;
 188
 189         while (1) {
 190                 int answer;
 191                 fprintf(stderr, "%s (y/n) ", question);
 192
 193                 if ((answer = read_yes_no_answer()) >= 0)
 194                         return answer;
 195
 196                 fprintf(stderr, "Sorry, I did not understand your answer. "
 197                                 "Please type 'y' or 'n'\n");
 198         }
 199 }
 200
 201 #undef unlink
 202 int mingw_unlink(const char *pathname)
 203 {
 204         int ret, tries = 0;
 205
 206         /* read-only files cannot be removed */
 207         chmod(pathname, 0666);
 208         while ((ret = unlink(pathname)) == -1 && tries < ARRAY_SIZE(delay)) {
 209                 if (!is_file_in_use_error(GetLastError()))
 210                         break;
 211                 /*
 212                  * We assume that some other process had the source or
 213                  * destination file open at the wrong moment and retry.
 214                  * In order to give the other process a higher chance to
 215                  * complete its operation, we give up our time slice now.
 216                  * If we have to retry again, we do sleep a bit.
 217                  */
 218                 Sleep(delay[tries]);
 219                 tries++;
 220         }
 221         while (ret == -1 && is_file_in_use_error(GetLastError()) &&
 222                ask_yes_no_if_possible("Unlink of file '%s' failed. "
 223                         "Should I try again?", pathname))
 224                ret = unlink(pathname);
 225         return ret;
 226 }
 227
 228 static int is_dir_empty(const char *path)
 229 {
 230         struct strbuf buf = STRBUF_INIT;
 231         WIN32_FIND_DATAA findbuf;
 232         HANDLE handle;
 233
 234         strbuf_addf(&buf, "%s\\*", path);
 235         handle = FindFirstFileA(buf.buf, &findbuf);
 236         if (handle == INVALID_HANDLE_VALUE) {
 237                 strbuf_release(&buf);
 238                 return GetLastError() == ERROR_NO_MORE_FILES;
 239         }
 240
 241         while (!strcmp(findbuf.cFileName, ".") ||
 242                         !strcmp(findbuf.cFileName, ".."))
 243                 if (!FindNextFile(handle, &findbuf)) {
 244                         strbuf_release(&buf);
 245                         return GetLastError() == ERROR_NO_MORE_FILES;
 246                 }
 247         FindClose(handle);
 248         strbuf_release(&buf);
 249         return 0;
 250 }
 251
 252 #undef rmdir
 253 int mingw_rmdir(const char *pathname)
 254 {
 255         int ret, tries = 0;
 256
 257         while ((ret = rmdir(pathname)) == -1 && tries < ARRAY_SIZE(delay)) {
 258                 if (!is_file_in_use_error(GetLastError()))
 259                         break;
 260                 if (!is_dir_empty(pathname)) {
 261                         errno = ENOTEMPTY;
 262                         break;
 263                 }
 264                 /*
 265                  * We assume that some other process had the source or
 266                  * destination file open at the wrong moment and retry.
 267                  * In order to give the other process a higher chance to
 268                  * complete its operation, we give up our time slice now.
 269                  * If we have to retry again, we do sleep a bit.
 270                  */
 271                 Sleep(delay[tries]);
 272                 tries++;
 273         }
 274         while (ret == -1 && is_file_in_use_error(GetLastError()) &&
 275                ask_yes_no_if_possible("Deletion of directory '%s' failed. "
 276                         "Should I try again?", pathname))
 277                ret = rmdir(pathname);
 278         return ret;
 279 }
 280
 281 #undef open
 282 int mingw_open (const char *filename, int oflags, ...)
 283 {
 284         va_list args;
 285         unsigned mode;
 286         int fd;
 287
 288         va_start(args, oflags);
 289         mode = va_arg(args, int);
 290         va_end(args);
 291
 292         if (filename && !strcmp(filename, "/dev/null"))
 293                 filename = "nul";
 294
 295         fd = open(filename, oflags, mode);
 296
 297         if (fd < 0 && (oflags & O_CREAT) && errno == EACCES) {
 298                 DWORD attrs = GetFileAttributes(filename);
 299                 if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY))
 300                         errno = EISDIR;
 301         }
 302         return fd;
 303 }
 304
 305 #undef write
 306 ssize_t mingw_write(int fd, const void *buf, size_t count)
 307 {
 308         /*
 309          * While write() calls to a file on a local disk are translated
 310          * into WriteFile() calls with a maximum size of 64KB on Windows
 311          * XP and 256KB on Vista, no such cap is placed on writes to
 312          * files over the network on Windows XP.  Unfortunately, there
 313          * seems to be a limit of 32MB-28KB on X64 and 64MB-32KB on x86;
 314          * bigger writes fail on Windows XP.
 315          * So we cap to a nice 31MB here to avoid write failures over
 316          * the net without changing the number of WriteFile() calls in
 317          * the local case.
 318          */
 319         return write(fd, buf, min(count, 31 * 1024 * 1024));
 320 }
 321
 322 static BOOL WINAPI ctrl_ignore(DWORD type)
 323 {
 324         return TRUE;
 325 }
 326
 327 #undef fgetc
 328 int mingw_fgetc(FILE *stream)
 329 {
 330         int ch;
 331         if (!isatty(_fileno(stream)))
 332                 return fgetc(stream);
 333
 334         SetConsoleCtrlHandler(ctrl_ignore, TRUE);
 335         while (1) {
 336                 ch = fgetc(stream);
 337                 if (ch != EOF || GetLastError() != ERROR_OPERATION_ABORTED)
 338                         break;
 339
 340                 /* Ctrl+C was pressed, simulate SIGINT and retry */
 341                 mingw_raise(SIGINT);
 342         }
 343         SetConsoleCtrlHandler(ctrl_ignore, FALSE);
 344         return ch;
 345 }
 346
 347 #undef fopen
 348 FILE *mingw_fopen (const char *filename, const char *otype)
 349 {
 350         if (filename && !strcmp(filename, "/dev/null"))
 351                 filename = "nul";
 352         return fopen(filename, otype);
 353 }
 354
 355 #undef freopen
 356 FILE *mingw_freopen (const char *filename, const char *otype, FILE *stream)
 357 {
 358         if (filename && !strcmp(filename, "/dev/null"))
 359                 filename = "nul";
 360         return freopen(filename, otype, stream);
 361 }
 362
 363 #undef fflush
 364 int mingw_fflush(FILE *stream)
 365 {
 366         int ret = fflush(stream);
 367
 368         /*
 369          * write() is used behind the scenes of stdio output functions.
 370          * Since git code does not check for errors after each stdio write
 371          * operation, it can happen that write() is called by a later
 372          * stdio function even if an earlier write() call failed. In the
 373          * case of a pipe whose readable end was closed, only the first
 374          * call to write() reports EPIPE on Windows. Subsequent write()
 375          * calls report EINVAL. It is impossible to notice whether this
 376          * fflush invocation triggered such a case, therefore, we have to
 377          * catch all EINVAL errors whole-sale.
 378          */
 379         if (ret && errno == EINVAL)
 380                 errno = EPIPE;
 381
 382         return ret;
 383 }
 384
 385 /*
 386  * The unit of FILETIME is 100-nanoseconds since January 1, 1601, UTC.
 387  * Returns the 100-nanoseconds ("hekto nanoseconds") since the epoch.
 388  */
 389 static inline long long filetime_to_hnsec(const FILETIME *ft)
 390 {
 391         long long winTime = ((long long)ft->dwHighDateTime << 32) + ft->dwLowDateTime;
 392         /* Windows to Unix Epoch conversion */
 393         return winTime - 116444736000000000LL;
 394 }
 395
 396 static inline time_t filetime_to_time_t(const FILETIME *ft)
 397 {
 398         return (time_t)(filetime_to_hnsec(ft) / 10000000);
 399 }
 400
 401 /* We keep the do_lstat code in a separate function to avoid recursion.
 402  * When a path ends with a slash, the stat will fail with ENOENT. In
 403  * this case, we strip the trailing slashes and stat again.
 404  *
 405  * If follow is true then act like stat() and report on the link
 406  * target. Otherwise report on the link itself.
 407  */
 408 static int do_lstat(int follow, const char *file_name, struct stat *buf)
 409 {
 410         int err;
 411         WIN32_FILE_ATTRIBUTE_DATA fdata;
 412
 413         if (!(err = get_file_attr(file_name, &fdata))) {
 414                 buf->st_ino = 0;
 415                 buf->st_gid = 0;
 416                 buf->st_uid = 0;
 417                 buf->st_nlink = 1;
 418                 buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes);
 419                 buf->st_size = fdata.nFileSizeLow |
 420                         (((off_t)fdata.nFileSizeHigh)<<32);
 421                 buf->st_dev = buf->st_rdev = 0; /* not used by Git */
 422                 buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime));
 423                 buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime));
 424                 buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime));
 425                 if (fdata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
 426                         WIN32_FIND_DATAA findbuf;
 427                         HANDLE handle = FindFirstFileA(file_name, &findbuf);
 428                         if (handle != INVALID_HANDLE_VALUE) {
 429                                 if ((findbuf.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) &&
 430                                                 (findbuf.dwReserved0 == IO_REPARSE_TAG_SYMLINK)) {
 431                                         if (follow) {
 432                                                 char buffer[MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
 433                                                 buf->st_size = readlink(file_name, buffer, MAXIMUM_REPARSE_DATA_BUFFER_SIZE);
 434                                         } else {
 435                                                 buf->st_mode = S_IFLNK;
 436                                         }
 437                                         buf->st_mode |= S_IREAD;
 438                                         if (!(findbuf.dwFileAttributes & FILE_ATTRIBUTE_READONLY))
 439                                                 buf->st_mode |= S_IWRITE;
 440                                 }
 441                                 FindClose(handle);
 442                         }
 443                 }
 444                 return 0;
 445         }
 446         errno = err;
 447         return -1;
 448 }
 449
 450 /* We provide our own lstat/fstat functions, since the provided
 451  * lstat/fstat functions are so slow. These stat functions are
 452  * tailored for Git's usage (read: fast), and are not meant to be
 453  * complete. Note that Git stat()s are redirected to mingw_lstat()
 454  * too, since Windows doesn't really handle symlinks that well.
 455  */
 456 static int do_stat_internal(int follow, const char *file_name, struct stat *buf)
 457 {
 458         int namelen;
 459         static char alt_name[PATH_MAX];
 460
 461         if (!do_lstat(follow, file_name, buf))
 462                 return 0;
 463
 464         /* if file_name ended in a '/', Windows returned ENOENT;
 465          * try again without trailing slashes
 466          */
 467         if (errno != ENOENT)
 468                 return -1;
 469
 470         namelen = strlen(file_name);
 471         if (namelen && file_name[namelen-1] != '/')
 472                 return -1;
 473         while (namelen && file_name[namelen-1] == '/')
 474                 --namelen;
 475         if (!namelen || namelen >= PATH_MAX)
 476                 return -1;
 477
 478         memcpy(alt_name, file_name, namelen);
 479         alt_name[namelen] = 0;
 480         return do_lstat(follow, alt_name, buf);
 481 }
 482
 483 int mingw_lstat(const char *file_name, struct stat *buf)
 484 {
 485         return do_stat_internal(0, file_name, buf);
 486 }
 487 int mingw_stat(const char *file_name, struct stat *buf)
 488 {
 489         return do_stat_internal(1, file_name, buf);
 490 }
 491
 492 #undef fstat
 493 int mingw_fstat(int fd, struct stat *buf)
 494 {
 495         HANDLE fh = (HANDLE)_get_osfhandle(fd);
 496         BY_HANDLE_FILE_INFORMATION fdata;
 497
 498         if (fh == INVALID_HANDLE_VALUE) {
 499                 errno = EBADF;
 500                 return -1;
 501         }
 502         /* direct non-file handles to MS's fstat() */
 503         if (GetFileType(fh) != FILE_TYPE_DISK)
 504                 return _fstati64(fd, buf);
 505
 506         if (GetFileInformationByHandle(fh, &fdata)) {
 507                 buf->st_ino = 0;
 508                 buf->st_gid = 0;
 509                 buf->st_uid = 0;
 510                 buf->st_nlink = 1;
 511                 buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes);
 512                 buf->st_size = fdata.nFileSizeLow |
 513                         (((off_t)fdata.nFileSizeHigh)<<32);
 514                 buf->st_dev = buf->st_rdev = 0; /* not used by Git */
 515                 buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime));
 516                 buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime));
 517                 buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime));
 518                 return 0;
 519         }
 520         errno = EBADF;
 521         return -1;
 522 }
 523
 524 static inline void time_t_to_filetime(time_t t, FILETIME *ft)
 525 {
 526         long long winTime = t * 10000000LL + 116444736000000000LL;
 527         ft->dwLowDateTime = winTime;
 528         ft->dwHighDateTime = winTime >> 32;
 529 }
 530
 531 int mingw_utime (const char *file_name, const struct utimbuf *times)
 532 {
 533         FILETIME mft, aft;
 534         int fh, rc;
 535
 536         /* must have write permission */
 537         DWORD attrs = GetFileAttributes(file_name);
 538         if (attrs != INVALID_FILE_ATTRIBUTES &&
 539             (attrs & FILE_ATTRIBUTE_READONLY)) {
 540                 /* ignore errors here; open() will report them */
 541                 SetFileAttributes(file_name, attrs & ~FILE_ATTRIBUTE_READONLY);
 542         }
 543
 544         if ((fh = open(file_name, O_RDWR | O_BINARY)) < 0) {
 545                 rc = -1;
 546                 goto revert_attrs;
 547         }
 548
 549         if (times) {
 550                 time_t_to_filetime(times->modtime, &mft);
 551                 time_t_to_filetime(times->actime, &aft);
 552         } else {
 553                 GetSystemTimeAsFileTime(&mft);
 554                 aft = mft;
 555         }
 556         if (!SetFileTime((HANDLE)_get_osfhandle(fh), NULL, &aft, &mft)) {
 557                 errno = EINVAL;
 558                 rc = -1;
 559         } else
 560                 rc = 0;
 561         close(fh);
 562
 563 revert_attrs:
 564         if (attrs != INVALID_FILE_ATTRIBUTES &&
 565             (attrs & FILE_ATTRIBUTE_READONLY)) {
 566                 /* ignore errors again */
 567                 SetFileAttributes(file_name, attrs);
 568         }
 569         return rc;
 570 }
 571
 572 unsigned int sleep (unsigned int seconds)
 573 {
 574         Sleep(seconds*1000);
 575         return 0;
 576 }
 577
 578 int mkstemp(char *template)
 579 {
 580         char *filename = mktemp(template);
 581         if (filename == NULL)
 582                 return -1;
 583         return open(filename, O_RDWR | O_CREAT, 0600);
 584 }
 585
 586 int gettimeofday(struct timeval *tv, void *tz)
 587 {
 588         FILETIME ft;
 589         long long hnsec;
 590
 591         GetSystemTimeAsFileTime(&ft);
 592         hnsec = filetime_to_hnsec(&ft);
 593         tv->tv_sec = hnsec / 10000000;
 594         tv->tv_usec = (hnsec % 10000000) / 10;
 595         return 0;
 596 }
 597
 598 int pipe(int filedes[2])
 599 {
 600         HANDLE h[2];
 601
 602         /* this creates non-inheritable handles */
 603         if (!CreatePipe(&h[0], &h[1], NULL, 8192)) {
 604                 errno = err_win_to_posix(GetLastError());
 605                 return -1;
 606         }
 607         filedes[0] = _open_osfhandle((int)h[0], O_NOINHERIT);
 608         if (filedes[0] < 0) {
 609                 CloseHandle(h[0]);
 610                 CloseHandle(h[1]);
 611                 return -1;
 612         }
 613         filedes[1] = _open_osfhandle((int)h[1], O_NOINHERIT);
 614         if (filedes[0] < 0) {
 615                 close(filedes[0]);
 616                 CloseHandle(h[1]);
 617                 return -1;
 618         }
 619         return 0;
 620 }
 621
 622 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 623 {
 624         /* gmtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 625         memcpy(result, gmtime(timep), sizeof(struct tm));
 626         return result;
 627 }
 628
 629 struct tm *localtime_r(const time_t *timep, struct tm *result)
 630 {
 631         /* localtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 632         memcpy(result, localtime(timep), sizeof(struct tm));
 633         return result;
 634 }
 635
 636 #undef getcwd
 637 char *mingw_getcwd(char *pointer, int len)
 638 {
 639         int i;
 640         char *ret = getcwd(pointer, len);
 641         if (!ret)
 642                 return ret;
 643         for (i = 0; pointer[i]; i++)
 644                 if (pointer[i] == '\\')
 645                         pointer[i] = '/';
 646         return ret;
 647 }
 648
 649 /*
 650  * See http://msdn2.microsoft.com/en-us/library/17w5ykft(vs.71).aspx
 651  * (Parsing C++ Command-Line Arguments)
 652  */
 653 static const char *quote_arg(const char *arg)
 654 {
 655         /* count chars to quote */
 656         int len = 0, n = 0;
 657         int force_quotes = 0;
 658         char *q, *d;
 659         const char *p = arg;
 660         if (!*p) force_quotes = 1;
 661         while (*p) {
 662                 if (isspace(*p) || *p == '*' || *p == '?' || *p == '{' || *p == '\'')
 663                         force_quotes = 1;
 664                 else if (*p == '"')
 665                         n++;
 666                 else if (*p == '\\') {
 667                         int count = 0;
 668                         while (*p == '\\') {
 669                                 count++;
 670                                 p++;
 671                                 len++;
 672                         }
 673                         if (*p == '"')
 674                                 n += count*2 + 1;
 675                         continue;
 676                 }
 677                 len++;
 678                 p++;
 679         }
 680         if (!force_quotes && n == 0)
 681                 return arg;
 682
 683         /* insert \ where necessary */
 684         d = q = xmalloc(len+n+3);
 685         *d++ = '"';
 686         while (*arg) {
 687                 if (*arg == '"')
 688                         *d++ = '\\';
 689                 else if (*arg == '\\') {
 690                         int count = 0;
 691                         while (*arg == '\\') {
 692                                 count++;
 693                                 *d++ = *arg++;
 694                         }
 695                         if (*arg == '"') {
 696                                 while (count-- > 0)
 697                                         *d++ = '\\';
 698                                 *d++ = '\\';
 699                         }
 700                 }
 701                 *d++ = *arg++;
 702         }
 703         *d++ = '"';
 704         *d++ = 0;
 705         return q;
 706 }
 707
 708 static const char *parse_interpreter(const char *cmd)
 709 {
 710         static char buf[100];
 711         char *p, *opt;
 712         int n, fd;
 713
 714         /* don't even try a .exe */
 715         n = strlen(cmd);
 716         if (n >= 4 && !strcasecmp(cmd+n-4, ".exe"))
 717                 return NULL;
 718
 719         fd = open(cmd, O_RDONLY);
 720         if (fd < 0)
 721                 return NULL;
 722         n = read(fd, buf, sizeof(buf)-1);
 723         close(fd);
 724         if (n < 4)      /* at least '#!/x' and not error */
 725                 return NULL;
 726
 727         if (buf[0] != '#' || buf[1] != '!')
 728                 return NULL;
 729         buf[n] = '\0';
 730         p = buf + strcspn(buf, "\r\n");
 731         if (!*p)
 732                 return NULL;
 733
 734         *p = '\0';
 735         if (!(p = strrchr(buf+2, '/')) && !(p = strrchr(buf+2, '\\')))
 736                 return NULL;
 737         /* strip options */
 738         if ((opt = strchr(p+1, ' ')))
 739                 *opt = '\0';
 740         return p+1;
 741 }
 742
 743 /*
 744  * Splits the PATH into parts.
 745  */
 746 static char **get_path_split(void)
 747 {
 748         char *p, **path, *envpath = mingw_getenv("PATH");
 749         int i, n = 0;
 750
 751         if (!envpath || !*envpath)
 752                 return NULL;
 753
 754         envpath = xstrdup(envpath);
 755         p = envpath;
 756         while (p) {
 757                 char *dir = p;
 758                 p = strchr(p, ';');
 759                 if (p) *p++ = '\0';
 760                 if (*dir) {     /* not earlier, catches series of ; */
 761                         ++n;
 762                 }
 763         }
 764         if (!n)
 765                 return NULL;
 766
 767         path = xmalloc((n+1)*sizeof(char *));
 768         p = envpath;
 769         i = 0;
 770         do {
 771                 if (*p)
 772                         path[i++] = xstrdup(p);
 773                 p = p+strlen(p)+1;
 774         } while (i < n);
 775         path[i] = NULL;
 776
 777         free(envpath);
 778
 779         return path;
 780 }
 781
 782 static void free_path_split(char **path)
 783 {
 784         char **p = path;
 785
 786         if (!path)
 787                 return;
 788
 789         while (*p)
 790                 free(*p++);
 791         free(path);
 792 }
 793
 794 /*
 795  * exe_only means that we only want to detect .exe files, but not scripts
 796  * (which do not have an extension)
 797  */
 798 static char *lookup_prog(const char *dir, const char *cmd, int isexe, int exe_only)
 799 {
 800         char path[MAX_PATH];
 801         snprintf(path, sizeof(path), "%s/%s.exe", dir, cmd);
 802
 803         if (!isexe && access(path, F_OK) == 0)
 804                 return xstrdup(path);
 805         path[strlen(path)-4] = '\0';
 806         if ((!exe_only || isexe) && access(path, F_OK) == 0)
 807                 if (!(GetFileAttributes(path) & FILE_ATTRIBUTE_DIRECTORY))
 808                         return xstrdup(path);
 809         return NULL;
 810 }
 811
 812 /*
 813  * Determines the absolute path of cmd using the split path in path.
 814  * If cmd contains a slash or backslash, no lookup is performed.
 815  */
 816 static char *path_lookup(const char *cmd, char **path, int exe_only)
 817 {
 818         char *prog = NULL;
 819         int len = strlen(cmd);
 820         int isexe = len >= 4 && !strcasecmp(cmd+len-4, ".exe");
 821
 822         if (strchr(cmd, '/') || strchr(cmd, '\\'))
 823                 prog = xstrdup(cmd);
 824
 825         while (!prog && *path)
 826                 prog = lookup_prog(*path++, cmd, isexe, exe_only);
 827
 828         return prog;
 829 }
 830
 831 static int env_compare(const void *a, const void *b)
 832 {
 833         char *const *ea = a;
 834         char *const *eb = b;
 835         return strcasecmp(*ea, *eb);
 836 }
 837
 838 struct pinfo_t {
 839         struct pinfo_t *next;
 840         pid_t pid;
 841         HANDLE proc;
 842 } pinfo_t;
 843 struct pinfo_t *pinfo = NULL;
 844 CRITICAL_SECTION pinfo_cs;
 845
 846 static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env,
 847                               const char *dir,
 848                               int prepend_cmd, int fhin, int fhout, int fherr)
 849 {
 850         STARTUPINFO si;
 851         PROCESS_INFORMATION pi;
 852         struct strbuf envblk, args;
 853         unsigned flags;
 854         BOOL ret;
 855
 856         /* Determine whether or not we are associated to a console */
 857         HANDLE cons = CreateFile("CONOUT$", GENERIC_WRITE,
 858                         FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
 859                         FILE_ATTRIBUTE_NORMAL, NULL);
 860         if (cons == INVALID_HANDLE_VALUE) {
 861                 /* There is no console associated with this process.
 862                  * Since the child is a console process, Windows
 863                  * would normally create a console window. But
 864                  * since we'll be redirecting std streams, we do
 865                  * not need the console.
 866                  * It is necessary to use DETACHED_PROCESS
 867                  * instead of CREATE_NO_WINDOW to make ssh
 868                  * recognize that it has no console.
 869                  */
 870                 flags = DETACHED_PROCESS;
 871         } else {
 872                 /* There is already a console. If we specified
 873                  * DETACHED_PROCESS here, too, Windows would
 874                  * disassociate the child from the console.
 875                  * The same is true for CREATE_NO_WINDOW.
 876                  * Go figure!
 877                  */
 878                 flags = 0;
 879                 CloseHandle(cons);
 880         }
 881         memset(&si, 0, sizeof(si));
 882         si.cb = sizeof(si);
 883         si.dwFlags = STARTF_USESTDHANDLES;
 884         si.hStdInput = (HANDLE) _get_osfhandle(fhin);
 885         si.hStdOutput = (HANDLE) _get_osfhandle(fhout);
 886         si.hStdError = (HANDLE) _get_osfhandle(fherr);
 887
 888         /* concatenate argv, quoting args as we go */
 889         strbuf_init(&args, 0);
 890         if (prepend_cmd) {
 891                 char *quoted = (char *)quote_arg(cmd);
 892                 strbuf_addstr(&args, quoted);
 893                 if (quoted != cmd)
 894                         free(quoted);
 895         }
 896         for (; *argv; argv++) {
 897                 char *quoted = (char *)quote_arg(*argv);
 898                 if (*args.buf)
 899                         strbuf_addch(&args, ' ');
 900                 strbuf_addstr(&args, quoted);
 901                 if (quoted != *argv)
 902                         free(quoted);
 903         }
 904
 905         if (env) {
 906                 int count = 0;
 907                 char **e, **sorted_env;
 908
 909                 for (e = env; *e; e++)
 910                         count++;
 911
 912                 /* environment must be sorted */
 913                 sorted_env = xmalloc(sizeof(*sorted_env) * (count + 1));
 914                 memcpy(sorted_env, env, sizeof(*sorted_env) * (count + 1));
 915                 qsort(sorted_env, count, sizeof(*sorted_env), env_compare);
 916
 917                 strbuf_init(&envblk, 0);
 918                 for (e = sorted_env; *e; e++) {
 919                         strbuf_addstr(&envblk, *e);
 920                         strbuf_addch(&envblk, '\0');
 921                 }
 922                 free(sorted_env);
 923         }
 924
 925         memset(&pi, 0, sizeof(pi));
 926         ret = CreateProcess(cmd, args.buf, NULL, NULL, TRUE, flags,
 927                 env ? envblk.buf : NULL, dir, &si, &pi);
 928
 929         if (env)
 930                 strbuf_release(&envblk);
 931         strbuf_release(&args);
 932
 933         if (!ret) {
 934                 errno = ENOENT;
 935                 return -1;
 936         }
 937         CloseHandle(pi.hThread);
 938
 939         /*
 940          * The process ID is the human-readable identifier of the process
 941          * that we want to present in log and error messages. The handle
 942          * is not useful for this purpose. But we cannot close it, either,
 943          * because it is not possible to turn a process ID into a process
 944          * handle after the process terminated.
 945          * Keep the handle in a list for waitpid.
 946          */
 947         EnterCriticalSection(&pinfo_cs);
 948         {
 949                 struct pinfo_t *info = xmalloc(sizeof(struct pinfo_t));
 950                 info->pid = pi.dwProcessId;
 951                 info->proc = pi.hProcess;
 952                 info->next = pinfo;
 953                 pinfo = info;
 954         }
 955         LeaveCriticalSection(&pinfo_cs);
 956
 957         return (pid_t)pi.dwProcessId;
 958 }
 959
 960 static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
 961                            int prepend_cmd)
 962 {
 963         return mingw_spawnve_fd(cmd, argv, env, NULL, prepend_cmd, 0, 1, 2);
 964 }
 965
 966 pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env,
 967                      const char *dir,
 968                      int fhin, int fhout, int fherr)
 969 {
 970         pid_t pid;
 971         char **path = get_path_split();
 972         char *prog = path_lookup(cmd, path, 0);
 973
 974         if (!prog) {
 975                 errno = ENOENT;
 976                 pid = -1;
 977         }
 978         else {
 979                 const char *interpr = parse_interpreter(prog);
 980
 981                 if (interpr) {
 982                         const char *argv0 = argv[0];
 983                         char *iprog = path_lookup(interpr, path, 1);
 984                         argv[0] = prog;
 985                         if (!iprog) {
 986                                 errno = ENOENT;
 987                                 pid = -1;
 988                         }
 989                         else {
 990                                 pid = mingw_spawnve_fd(iprog, argv, env, dir, 1,
 991                                                        fhin, fhout, fherr);
 992                                 free(iprog);
 993                         }
 994                         argv[0] = argv0;
 995                 }
 996                 else
 997                         pid = mingw_spawnve_fd(prog, argv, env, dir, 0,
 998                                                fhin, fhout, fherr);
 999                 free(prog);
1000         }
1001         free_path_split(path);
1002         return pid;
1003 }
1004
1005 static int try_shell_exec(const char *cmd, char *const *argv, char **env)
1006 {
1007         const char *interpr = parse_interpreter(cmd);
1008         char **path;
1009         char *prog;
1010         int pid = 0;
1011
1012         if (!interpr)
1013                 return 0;
1014         path = get_path_split();
1015         prog = path_lookup(interpr, path, 1);
1016         if (prog) {
1017                 int argc = 0;
1018                 const char **argv2;
1019                 while (argv[argc]) argc++;
1020                 argv2 = xmalloc(sizeof(*argv) * (argc+1));
1021                 argv2[0] = (char *)cmd; /* full path to the script file */
1022                 memcpy(&argv2[1], &argv[1], sizeof(*argv) * argc);
1023                 pid = mingw_spawnve(prog, argv2, env, 1);
1024                 if (pid >= 0) {
1025                         int status;
1026                         if (waitpid(pid, &status, 0) < 0)
1027                                 status = 255;
1028                         exit(status);
1029                 }
1030                 pid = 1;        /* indicate that we tried but failed */
1031                 free(prog);
1032                 free(argv2);
1033         }
1034         free_path_split(path);
1035         return pid;
1036 }
1037
1038 static void mingw_execve(const char *cmd, char *const *argv, char *const *env)
1039 {
1040         /* check if git_command is a shell script */
1041         if (!try_shell_exec(cmd, argv, (char **)env)) {
1042                 int pid, status;
1043
1044                 pid = mingw_spawnve(cmd, (const char **)argv, (char **)env, 0);
1045                 if (pid < 0)
1046                         return;
1047                 if (waitpid(pid, &status, 0) < 0)
1048                         status = 255;
1049                 exit(status);
1050         }
1051 }
1052
1053 int mingw_execvp(const char *cmd, char *const *argv)
1054 {
1055         char **path = get_path_split();
1056         char *prog = path_lookup(cmd, path, 0);
1057
1058         if (prog) {
1059                 mingw_execve(prog, argv, environ);
1060                 free(prog);
1061         } else
1062                 errno = ENOENT;
1063
1064         free_path_split(path);
1065         return -1;
1066 }
1067
1068 int mingw_execv(const char *cmd, char *const *argv)
1069 {
1070         mingw_execve(cmd, argv, environ);
1071         return -1;
1072 }
1073
1074 int mingw_kill(pid_t pid, int sig)
1075 {
1076         if (pid > 0 && sig == SIGTERM) {
1077                 HANDLE h = OpenProcess(PROCESS_TERMINATE, FALSE, pid);
1078
1079                 if (TerminateProcess(h, -1)) {
1080                         CloseHandle(h);
1081                         return 0;
1082                 }
1083
1084                 errno = err_win_to_posix(GetLastError());
1085                 CloseHandle(h);
1086                 return -1;
1087         }
1088
1089         errno = EINVAL;
1090         return -1;
1091 }
1092
1093 static char **copy_environ(void)
1094 {
1095         char **env;
1096         int i = 0;
1097         while (environ[i])
1098                 i++;
1099         env = xmalloc((i+1)*sizeof(*env));
1100         for (i = 0; environ[i]; i++)
1101                 env[i] = xstrdup(environ[i]);
1102         env[i] = NULL;
1103         return env;
1104 }
1105
1106 void free_environ(char **env)
1107 {
1108         int i;
1109         for (i = 0; env[i]; i++)
1110                 free(env[i]);
1111         free(env);
1112 }
1113
1114 static int lookup_env(char **env, const char *name, size_t nmln)
1115 {
1116         int i;
1117
1118         for (i = 0; env[i]; i++) {
1119                 if (0 == strncmp(env[i], name, nmln)
1120                     && '=' == env[i][nmln])
1121                         /* matches */
1122                         return i;
1123         }
1124         return -1;
1125 }
1126
1127 /*
1128  * If name contains '=', then sets the variable, otherwise it unsets it
1129  */
1130 static char **env_setenv(char **env, const char *name)
1131 {
1132         char *eq = strchrnul(name, '=');
1133         int i = lookup_env(env, name, eq-name);
1134
1135         if (i < 0) {
1136                 if (*eq) {
1137                         for (i = 0; env[i]; i++)
1138                                 ;
1139                         env = xrealloc(env, (i+2)*sizeof(*env));
1140                         env[i] = xstrdup(name);
1141                         env[i+1] = NULL;
1142                 }
1143         }
1144         else {
1145                 free(env[i]);
1146                 if (*eq)
1147                         env[i] = xstrdup(name);
1148                 else
1149                         for (; env[i]; i++)
1150                                 env[i] = env[i+1];
1151         }
1152         return env;
1153 }
1154
1155 /*
1156  * Copies global environ and adjusts variables as specified by vars.
1157  */
1158 char **make_augmented_environ(const char *const *vars)
1159 {
1160         char **env = copy_environ();
1161
1162         while (*vars)
1163                 env = env_setenv(env, *vars++);
1164         return env;
1165 }
1166
1167 #undef getenv
1168
1169 /*
1170  * The system's getenv looks up the name in a case-insensitive manner.
1171  * This version tries a case-sensitive lookup and falls back to
1172  * case-insensitive if nothing was found.  This is necessary because,
1173  * as a prominent example, CMD sets 'Path', but not 'PATH'.
1174  * Warning: not thread-safe.
1175  */
1176 static char *getenv_cs(const char *name)
1177 {
1178         size_t len = strlen(name);
1179         int i = lookup_env(environ, name, len);
1180         if (i >= 0)
1181                 return environ[i] + len + 1;    /* skip past name and '=' */
1182         return getenv(name);
1183 }
1184
1185 char *mingw_getenv(const char *name)
1186 {
1187         char *result = getenv_cs(name);
1188         if (!result && !strcmp(name, "TMPDIR")) {
1189                 /* on Windows it is TMP and TEMP */
1190                 result = getenv_cs("TMP");
1191                 if (!result)
1192                         result = getenv_cs("TEMP");
1193         }
1194         return result;
1195 }
1196
1197 /*
1198  * Note, this isn't a complete replacement for getaddrinfo. It assumes
1199  * that service contains a numerical port, or that it is null. It
1200  * does a simple search using gethostbyname, and returns one IPv4 host
1201  * if one was found.
1202  */
1203 static int WSAAPI getaddrinfo_stub(const char *node, const char *service,
1204                                    const struct addrinfo *hints,
1205                                    struct addrinfo **res)
1206 {
1207         struct hostent *h = NULL;
1208         struct addrinfo *ai;
1209         struct sockaddr_in *sin;
1210
1211         if (node) {
1212                 h = gethostbyname(node);
1213                 if (!h)
1214                         return WSAGetLastError();
1215         }
1216
1217         ai = xmalloc(sizeof(struct addrinfo));
1218         *res = ai;
1219         ai->ai_flags = 0;
1220         ai->ai_family = AF_INET;
1221         ai->ai_socktype = hints ? hints->ai_socktype : 0;
1222         switch (ai->ai_socktype) {
1223         case SOCK_STREAM:
1224                 ai->ai_protocol = IPPROTO_TCP;
1225                 break;
1226         case SOCK_DGRAM:
1227                 ai->ai_protocol = IPPROTO_UDP;
1228                 break;
1229         default:
1230                 ai->ai_protocol = 0;
1231                 break;
1232         }
1233         ai->ai_addrlen = sizeof(struct sockaddr_in);
1234         if (hints && (hints->ai_flags & AI_CANONNAME))
1235                 ai->ai_canonname = h ? xstrdup(h->h_name) : NULL;
1236         else
1237                 ai->ai_canonname = NULL;
1238
1239         sin = xmalloc(ai->ai_addrlen);
1240         memset(sin, 0, ai->ai_addrlen);
1241         sin->sin_family = AF_INET;
1242         /* Note: getaddrinfo is supposed to allow service to be a string,
1243          * which should be looked up using getservbyname. This is
1244          * currently not implemented */
1245         if (service)
1246                 sin->sin_port = htons(atoi(service));
1247         if (h)
1248                 sin->sin_addr = *(struct in_addr *)h->h_addr;
1249         else if (hints && (hints->ai_flags & AI_PASSIVE))
1250                 sin->sin_addr.s_addr = INADDR_ANY;
1251         else
1252                 sin->sin_addr.s_addr = INADDR_LOOPBACK;
1253         ai->ai_addr = (struct sockaddr *)sin;
1254         ai->ai_next = 0;
1255         return 0;
1256 }
1257
1258 static void WSAAPI freeaddrinfo_stub(struct addrinfo *res)
1259 {
1260         free(res->ai_canonname);
1261         free(res->ai_addr);
1262         free(res);
1263 }
1264
1265 static int WSAAPI getnameinfo_stub(const struct sockaddr *sa, socklen_t salen,
1266                                    char *host, DWORD hostlen,
1267                                    char *serv, DWORD servlen, int flags)
1268 {
1269         const struct sockaddr_in *sin = (const struct sockaddr_in *)sa;
1270         if (sa->sa_family != AF_INET)
1271                 return EAI_FAMILY;
1272         if (!host && !serv)
1273                 return EAI_NONAME;
1274
1275         if (host && hostlen > 0) {
1276                 struct hostent *ent = NULL;
1277                 if (!(flags & NI_NUMERICHOST))
1278                         ent = gethostbyaddr((const char *)&sin->sin_addr,
1279                                             sizeof(sin->sin_addr), AF_INET);
1280
1281                 if (ent)
1282                         snprintf(host, hostlen, "%s", ent->h_name);
1283                 else if (flags & NI_NAMEREQD)
1284                         return EAI_NONAME;
1285                 else
1286                         snprintf(host, hostlen, "%s", inet_ntoa(sin->sin_addr));
1287         }
1288
1289         if (serv && servlen > 0) {
1290                 struct servent *ent = NULL;
1291                 if (!(flags & NI_NUMERICSERV))
1292                         ent = getservbyport(sin->sin_port,
1293                                             flags & NI_DGRAM ? "udp" : "tcp");
1294
1295                 if (ent)
1296                         snprintf(serv, servlen, "%s", ent->s_name);
1297                 else
1298                         snprintf(serv, servlen, "%d", ntohs(sin->sin_port));
1299         }
1300
1301         return 0;
1302 }
1303
1304 static HMODULE ipv6_dll = NULL;
1305 static void (WSAAPI *ipv6_freeaddrinfo)(struct addrinfo *res);
1306 static int (WSAAPI *ipv6_getaddrinfo)(const char *node, const char *service,
1307                                       const struct addrinfo *hints,
1308                                       struct addrinfo **res);
1309 static int (WSAAPI *ipv6_getnameinfo)(const struct sockaddr *sa, socklen_t salen,
1310                                       char *host, DWORD hostlen,
1311                                       char *serv, DWORD servlen, int flags);
1312 /*
1313  * gai_strerror is an inline function in the ws2tcpip.h header, so we
1314  * don't need to try to load that one dynamically.
1315  */
1316
1317 static void socket_cleanup(void)
1318 {
1319         WSACleanup();
1320         if (ipv6_dll)
1321                 FreeLibrary(ipv6_dll);
1322         ipv6_dll = NULL;
1323         ipv6_freeaddrinfo = freeaddrinfo_stub;
1324         ipv6_getaddrinfo = getaddrinfo_stub;
1325         ipv6_getnameinfo = getnameinfo_stub;
1326 }
1327
1328 static void ensure_socket_initialization(void)
1329 {
1330         WSADATA wsa;
1331         static int initialized = 0;
1332         const char *libraries[] = { "ws2_32.dll", "wship6.dll", NULL };
1333         const char **name;
1334
1335         if (initialized)
1336                 return;
1337
1338         if (WSAStartup(MAKEWORD(2,2), &wsa))
1339                 die("unable to initialize winsock subsystem, error %d",
1340                         WSAGetLastError());
1341
1342         for (name = libraries; *name; name++) {
1343                 ipv6_dll = LoadLibrary(*name);
1344                 if (!ipv6_dll)
1345                         continue;
1346
1347                 ipv6_freeaddrinfo = (void (WSAAPI *)(struct addrinfo *))
1348                         GetProcAddress(ipv6_dll, "freeaddrinfo");
1349                 ipv6_getaddrinfo = (int (WSAAPI *)(const char *, const char *,
1350                                                    const struct addrinfo *,
1351                                                    struct addrinfo **))
1352                         GetProcAddress(ipv6_dll, "getaddrinfo");
1353                 ipv6_getnameinfo = (int (WSAAPI *)(const struct sockaddr *,
1354                                                    socklen_t, char *, DWORD,
1355                                                    char *, DWORD, int))
1356                         GetProcAddress(ipv6_dll, "getnameinfo");
1357                 if (!ipv6_freeaddrinfo || !ipv6_getaddrinfo || !ipv6_getnameinfo) {
1358                         FreeLibrary(ipv6_dll);
1359                         ipv6_dll = NULL;
1360                 } else
1361                         break;
1362         }
1363         if (!ipv6_freeaddrinfo || !ipv6_getaddrinfo || !ipv6_getnameinfo) {
1364                 ipv6_freeaddrinfo = freeaddrinfo_stub;
1365                 ipv6_getaddrinfo = getaddrinfo_stub;
1366                 ipv6_getnameinfo = getnameinfo_stub;
1367         }
1368
1369         atexit(socket_cleanup);
1370         initialized = 1;
1371 }
1372
1373 #undef gethostname
1374 int mingw_gethostname(char *name, int namelen)
1375 {
1376     ensure_socket_initialization();
1377     return gethostname(name, namelen);
1378 }
1379
1380 #undef gethostbyname
1381 struct hostent *mingw_gethostbyname(const char *host)
1382 {
1383         ensure_socket_initialization();
1384         return gethostbyname(host);
1385 }
1386
1387 void mingw_freeaddrinfo(struct addrinfo *res)
1388 {
1389         ipv6_freeaddrinfo(res);
1390 }
1391
1392 int mingw_getaddrinfo(const char *node, const char *service,
1393                       const struct addrinfo *hints, struct addrinfo **res)
1394 {
1395         ensure_socket_initialization();
1396         return ipv6_getaddrinfo(node, service, hints, res);
1397 }
1398
1399 int mingw_getnameinfo(const struct sockaddr *sa, socklen_t salen,
1400                       char *host, DWORD hostlen, char *serv, DWORD servlen,
1401                       int flags)
1402 {
1403         ensure_socket_initialization();
1404         return ipv6_getnameinfo(sa, salen, host, hostlen, serv, servlen, flags);
1405 }
1406
1407 int mingw_socket(int domain, int type, int protocol)
1408 {
1409         int sockfd;
1410         SOCKET s;
1411
1412         ensure_socket_initialization();
1413         s = WSASocket(domain, type, protocol, NULL, 0, 0);
1414         if (s == INVALID_SOCKET) {
1415                 /*
1416                  * WSAGetLastError() values are regular BSD error codes
1417                  * biased by WSABASEERR.
1418                  * However, strerror() does not know about networking
1419                  * specific errors, which are values beginning at 38 or so.
1420                  * Therefore, we choose to leave the biased error code
1421                  * in errno so that _if_ someone looks up the code somewhere,
1422                  * then it is at least the number that are usually listed.
1423                  */
1424                 errno = WSAGetLastError();
1425                 return -1;
1426         }
1427         /* convert into a file descriptor */
1428         if ((sockfd = _open_osfhandle(s, O_RDWR|O_BINARY)) < 0) {
1429                 closesocket(s);
1430                 return error("unable to make a socket file descriptor: %s",
1431                         strerror(errno));
1432         }
1433         return sockfd;
1434 }
1435
1436 #undef connect
1437 int mingw_connect(int sockfd, struct sockaddr *sa, size_t sz)
1438 {
1439         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
1440         return connect(s, sa, sz);
1441 }
1442
1443 #undef bind
1444 int mingw_bind(int sockfd, struct sockaddr *sa, size_t sz)
1445 {
1446         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
1447         return bind(s, sa, sz);
1448 }
1449
1450 #undef setsockopt
1451 int mingw_setsockopt(int sockfd, int lvl, int optname, void *optval, int optlen)
1452 {
1453         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
1454         return setsockopt(s, lvl, optname, (const char*)optval, optlen);
1455 }
1456
1457 #undef shutdown
1458 int mingw_shutdown(int sockfd, int how)
1459 {
1460         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
1461         return shutdown(s, how);
1462 }
1463
1464 #undef listen
1465 int mingw_listen(int sockfd, int backlog)
1466 {
1467         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
1468         return listen(s, backlog);
1469 }
1470
1471 #undef accept
1472 int mingw_accept(int sockfd1, struct sockaddr *sa, socklen_t *sz)
1473 {
1474         int sockfd2;
1475
1476         SOCKET s1 = (SOCKET)_get_osfhandle(sockfd1);
1477         SOCKET s2 = accept(s1, sa, sz);
1478
1479         /* convert into a file descriptor */
1480         if ((sockfd2 = _open_osfhandle(s2, O_RDWR|O_BINARY)) < 0) {
1481                 int err = errno;
1482                 closesocket(s2);
1483                 return error("unable to make a socket file descriptor: %s",
1484                         strerror(err));
1485         }
1486         return sockfd2;
1487 }
1488
1489 #undef rename
1490 int mingw_rename(const char *pold, const char *pnew)
1491 {
1492         DWORD attrs, gle;
1493         int tries = 0;
1494
1495         /*
1496          * Try native rename() first to get errno right.
1497          * It is based on MoveFile(), which cannot overwrite existing files.
1498          */
1499         if (!rename(pold, pnew))
1500                 return 0;
1501         if (errno != EEXIST)
1502                 return -1;
1503 repeat:
1504         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
1505                 return 0;
1506         /* TODO: translate more errors */
1507         gle = GetLastError();
1508         if (gle == ERROR_ACCESS_DENIED &&
1509             (attrs = GetFileAttributes(pnew)) != INVALID_FILE_ATTRIBUTES) {
1510                 if (attrs & FILE_ATTRIBUTE_DIRECTORY) {
1511                         errno = EISDIR;
1512                         return -1;
1513                 }
1514                 if ((attrs & FILE_ATTRIBUTE_READONLY) &&
1515                     SetFileAttributes(pnew, attrs & ~FILE_ATTRIBUTE_READONLY)) {
1516                         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
1517                                 return 0;
1518                         gle = GetLastError();
1519                         /* revert file attributes on failure */
1520                         SetFileAttributes(pnew, attrs);
1521                 }
1522         }
1523         if (tries < ARRAY_SIZE(delay) && gle == ERROR_ACCESS_DENIED) {
1524                 /*
1525                  * We assume that some other process had the source or
1526                  * destination file open at the wrong moment and retry.
1527                  * In order to give the other process a higher chance to
1528                  * complete its operation, we give up our time slice now.
1529                  * If we have to retry again, we do sleep a bit.
1530                  */
1531                 Sleep(delay[tries]);
1532                 tries++;
1533                 goto repeat;
1534         }
1535         if (gle == ERROR_ACCESS_DENIED &&
1536                ask_yes_no_if_possible("Rename from '%s' to '%s' failed. "
1537                        "Should I try again?", pold, pnew))
1538                 goto repeat;
1539
1540         errno = EACCES;
1541         return -1;
1542 }
1543
1544 /*
1545  * Note that this doesn't return the actual pagesize, but
1546  * the allocation granularity. If future Windows specific git code
1547  * needs the real getpagesize function, we need to find another solution.
1548  */
1549 int mingw_getpagesize(void)
1550 {
1551         SYSTEM_INFO si;
1552         GetSystemInfo(&si);
1553         return si.dwAllocationGranularity;
1554 }
1555
1556 struct passwd *getpwuid(int uid)
1557 {
1558         static char user_name[100];
1559         static struct passwd p;
1560
1561         DWORD len = sizeof(user_name);
1562         if (!GetUserName(user_name, &len))
1563                 return NULL;
1564         p.pw_name = user_name;
1565         p.pw_gecos = "unknown";
1566         p.pw_dir = NULL;
1567         return &p;
1568 }
1569
1570 static HANDLE timer_event;
1571 static HANDLE timer_thread;
1572 static int timer_interval;
1573 static int one_shot;
1574 static sig_handler_t timer_fn = SIG_DFL, sigint_fn = SIG_DFL;
1575
1576 /* The timer works like this:
1577  * The thread, ticktack(), is a trivial routine that most of the time
1578  * only waits to receive the signal to terminate. The main thread tells
1579  * the thread to terminate by setting the timer_event to the signalled
1580  * state.
1581  * But ticktack() interrupts the wait state after the timer's interval
1582  * length to call the signal handler.
1583  */
1584
1585 static unsigned __stdcall ticktack(void *dummy)
1586 {
1587         while (WaitForSingleObject(timer_event, timer_interval) == WAIT_TIMEOUT) {
1588                 mingw_raise(SIGALRM);
1589                 if (one_shot)
1590                         break;
1591         }
1592         return 0;
1593 }
1594
1595 static int start_timer_thread(void)
1596 {
1597         timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
1598         if (timer_event) {
1599                 timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
1600                 if (!timer_thread )
1601                         return errno = ENOMEM,
1602                                 error("cannot start timer thread");
1603         } else
1604                 return errno = ENOMEM,
1605                         error("cannot allocate resources for timer");
1606         return 0;
1607 }
1608
1609 static void stop_timer_thread(void)
1610 {
1611         if (timer_event)
1612                 SetEvent(timer_event);  /* tell thread to terminate */
1613         if (timer_thread) {
1614                 int rc = WaitForSingleObject(timer_thread, 1000);
1615                 if (rc == WAIT_TIMEOUT)
1616                         error("timer thread did not terminate timely");
1617                 else if (rc != WAIT_OBJECT_0)
1618                         error("waiting for timer thread failed: %lu",
1619                               GetLastError());
1620                 CloseHandle(timer_thread);
1621         }
1622         if (timer_event)
1623                 CloseHandle(timer_event);
1624         timer_event = NULL;
1625         timer_thread = NULL;
1626 }
1627
1628 static inline int is_timeval_eq(const struct timeval *i1, const struct timeval *i2)
1629 {
1630         return i1->tv_sec == i2->tv_sec && i1->tv_usec == i2->tv_usec;
1631 }
1632
1633 int setitimer(int type, struct itimerval *in, struct itimerval *out)
1634 {
1635         static const struct timeval zero;
1636         static int atexit_done;
1637
1638         if (out != NULL)
1639                 return errno = EINVAL,
1640                         error("setitimer param 3 != NULL not implemented");
1641         if (!is_timeval_eq(&in->it_interval, &zero) &&
1642             !is_timeval_eq(&in->it_interval, &in->it_value))
1643                 return errno = EINVAL,
1644                         error("setitimer: it_interval must be zero or eq it_value");
1645
1646         if (timer_thread)
1647                 stop_timer_thread();
1648
1649         if (is_timeval_eq(&in->it_value, &zero) &&
1650             is_timeval_eq(&in->it_interval, &zero))
1651                 return 0;
1652
1653         timer_interval = in->it_value.tv_sec * 1000 + in->it_value.tv_usec / 1000;
1654         one_shot = is_timeval_eq(&in->it_interval, &zero);
1655         if (!atexit_done) {
1656                 atexit(stop_timer_thread);
1657                 atexit_done = 1;
1658         }
1659         return start_timer_thread();
1660 }
1661
1662 int sigaction(int sig, struct sigaction *in, struct sigaction *out)
1663 {
1664         if (sig != SIGALRM)
1665                 return errno = EINVAL,
1666                         error("sigaction only implemented for SIGALRM");
1667         if (out != NULL)
1668                 return errno = EINVAL,
1669                         error("sigaction: param 3 != NULL not implemented");
1670
1671         timer_fn = in->sa_handler;
1672         return 0;
1673 }
1674
1675 #undef signal
1676 sig_handler_t mingw_signal(int sig, sig_handler_t handler)
1677 {
1678         sig_handler_t old = timer_fn;
1679
1680         switch (sig) {
1681         case SIGALRM:
1682                 timer_fn = handler;
1683                 break;
1684
1685         case SIGINT:
1686                 sigint_fn = handler;
1687                 break;
1688
1689         default:
1690                 return signal(sig, handler);
1691         }
1692
1693         return old;
1694 }
1695
1696 #undef raise
1697 int mingw_raise(int sig)
1698 {
1699         switch (sig) {
1700         case SIGALRM:
1701                 if (timer_fn == SIG_DFL) {
1702                         if (isatty(STDERR_FILENO))
1703                                 fputs("Alarm clock\n", stderr);
1704                         exit(128 + SIGALRM);
1705                 } else if (timer_fn != SIG_IGN)
1706                         timer_fn(SIGALRM);
1707                 return 0;
1708
1709         case SIGINT:
1710                 if (sigint_fn == SIG_DFL)
1711                         exit(128 + SIGINT);
1712                 else if (sigint_fn != SIG_IGN)
1713                         sigint_fn(SIGINT);
1714                 return 0;
1715
1716         default:
1717                 return raise(sig);
1718         }
1719 }
1720
1721
1722 static const char *make_backslash_path(const char *path)
1723 {
1724         static char buf[PATH_MAX + 1];
1725         char *c;
1726
1727         if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
1728                 die("Too long path: %.*s", 60, path);
1729
1730         for (c = buf; *c; c++) {
1731                 if (*c == '/')
1732                         *c = '\\';
1733         }
1734         return buf;
1735 }
1736
1737 void mingw_open_html(const char *unixpath)
1738 {
1739         const char *htmlpath = make_backslash_path(unixpath);
1740         typedef HINSTANCE (WINAPI *T)(HWND, const char *,
1741                         const char *, const char *, const char *, INT);
1742         T ShellExecute;
1743         HMODULE shell32;
1744         int r;
1745
1746         shell32 = LoadLibrary("shell32.dll");
1747         if (!shell32)
1748                 die("cannot load shell32.dll");
1749         ShellExecute = (T)GetProcAddress(shell32, "ShellExecuteA");
1750         if (!ShellExecute)
1751                 die("cannot run browser");
1752
1753         printf("Launching default browser to display HTML ...\n");
1754         r = (int)ShellExecute(NULL, "open", htmlpath, NULL, "\\", SW_SHOWNORMAL);
1755         FreeLibrary(shell32);
1756         /* see the MSDN documentation referring to the result codes here */
1757         if (r <= 32) {
1758                 die("failed to launch browser for %.*s", MAX_PATH, unixpath);
1759         }
1760 }
1761
1762 int link(const char *oldpath, const char *newpath)
1763 {
1764         typedef BOOL (WINAPI *T)(const char*, const char*, LPSECURITY_ATTRIBUTES);
1765         static T create_hard_link = NULL;
1766         if (!create_hard_link) {
1767                 create_hard_link = (T) GetProcAddress(
1768                         GetModuleHandle("kernel32.dll"), "CreateHardLinkA");
1769                 if (!create_hard_link)
1770                         create_hard_link = (T)-1;
1771         }
1772         if (create_hard_link == (T)-1) {
1773                 errno = ENOSYS;
1774                 return -1;
1775         }
1776         if (!create_hard_link(newpath, oldpath, NULL)) {
1777                 errno = err_win_to_posix(GetLastError());
1778                 return -1;
1779         }
1780         return 0;
1781 }
1782
1783 char *getpass(const char *prompt)
1784 {
1785         struct strbuf buf = STRBUF_INIT;
1786
1787         fputs(prompt, stderr);
1788         for (;;) {
1789                 char c = _getch();
1790                 if (c == '\r' || c == '\n')
1791                         break;
1792                 strbuf_addch(&buf, c);
1793         }
1794         fputs("\n", stderr);
1795         return strbuf_detach(&buf, NULL);
1796 }
1797
1798 pid_t waitpid(pid_t pid, int *status, int options)
1799 {
1800         HANDLE h = OpenProcess(SYNCHRONIZE | PROCESS_QUERY_INFORMATION,
1801             FALSE, pid);
1802         if (!h) {
1803                 errno = ECHILD;
1804                 return -1;
1805         }
1806
1807         if (pid > 0 && options & WNOHANG) {
1808                 if (WAIT_OBJECT_0 != WaitForSingleObject(h, 0)) {
1809                         CloseHandle(h);
1810                         return 0;
1811                 }
1812                 options &= ~WNOHANG;
1813         }
1814
1815         if (options == 0) {
1816                 struct pinfo_t **ppinfo;
1817                 if (WaitForSingleObject(h, INFINITE) != WAIT_OBJECT_0) {
1818                         CloseHandle(h);
1819                         return 0;
1820                 }
1821
1822                 if (status)
1823                         GetExitCodeProcess(h, (LPDWORD)status);
1824
1825                 EnterCriticalSection(&pinfo_cs);
1826
1827                 ppinfo = &pinfo;
1828                 while (*ppinfo) {
1829                         struct pinfo_t *info = *ppinfo;
1830                         if (info->pid == pid) {
1831                                 CloseHandle(info->proc);
1832                                 *ppinfo = info->next;
1833                                 free(info);
1834                                 break;
1835                         }
1836                         ppinfo = &info->next;
1837                 }
1838
1839                 LeaveCriticalSection(&pinfo_cs);
1840
1841                 CloseHandle(h);
1842                 return pid;
1843         }
1844         CloseHandle(h);
1845
1846         errno = EINVAL;
1847         return -1;
1848 }