From 0181eb0c78d04f5fb065cbe2f3346077b0f9930e Mon Sep 17 00:00:00 2001 From: Karsten Blees Date: Sat, 16 May 2015 01:18:14 +0200 Subject: [PATCH] Win32: implement stat() with symlink support With respect to symlinks, the current stat() implementation is almost the same as lstat(): except for the file type (st_mode & S_IFMT), it returns information about the link rather than the target. Implement stat by opening the file with as little permissions as possible and calling GetFileInformationByHandle on it. This way, all link resoltion is handled by the Windows file system layer. If symlinks are disabled, use lstat() as before, but fail with ELOOP if a symlink would have to be resolved. Signed-off-by: Karsten Blees --- compat/mingw.c | 54 +++++++++++++++++++++++++++++++++++--------------- 1 file changed, 38 insertions(+), 16 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index 534be0fb80..3f50107bf6 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -724,16 +724,50 @@ int mingw_lstat(const char *file_name, struct stat *buf) { return do_lstat(0, file_name, buf); } + +static int get_file_info_by_handle(HANDLE hnd, struct stat *buf) +{ + BY_HANDLE_FILE_INFORMATION fdata; + if (!GetFileInformationByHandle(hnd, &fdata)) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + buf->st_ino = 0; + buf->st_dev = buf->st_rdev = 0; /* not used by Git */ + buf->st_gid = buf->st_uid = 0; + buf->st_nlink = 1; + buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes); + buf->st_size = fdata.nFileSizeLow | (((off_t) fdata.nFileSizeHigh) << 32); + buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime)); + buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime)); + buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime)); + return 0; +} + int mingw_stat(const char *file_name, struct stat *buf) { - return do_lstat(1, file_name, buf); + wchar_t wfile_name[MAX_LONG_PATH]; + HANDLE hnd; + int result; + + /* open the file and let Windows resolve the links */ + if (xutftowcs_long_path(wfile_name, file_name) < 0) + return -1; + hnd = CreateFileW(wfile_name, 0, + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, + OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL); + if (hnd == INVALID_HANDLE_VALUE) { + errno = err_win_to_posix(GetLastError()); + return -1; + } + result = get_file_info_by_handle(hnd, buf); + CloseHandle(hnd); + return result; } int mingw_fstat(int fd, struct stat *buf) { HANDLE fh = (HANDLE)_get_osfhandle(fd); - BY_HANDLE_FILE_INFORMATION fdata; - if (fh == INVALID_HANDLE_VALUE) { errno = EBADF; return -1; @@ -742,20 +776,8 @@ int mingw_fstat(int fd, struct stat *buf) if (GetFileType(fh) != FILE_TYPE_DISK) return _fstati64(fd, buf); - if (GetFileInformationByHandle(fh, &fdata)) { - buf->st_ino = 0; - buf->st_gid = 0; - buf->st_uid = 0; - buf->st_nlink = 1; - buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes); - buf->st_size = fdata.nFileSizeLow | - (((off_t)fdata.nFileSizeHigh)<<32); - buf->st_dev = buf->st_rdev = 0; /* not used by Git */ - buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime)); - buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime)); - buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime)); + if (!get_file_info_by_handle(fh, buf)) return 0; - } errno = EBADF; return -1; }