[PATCH 5/5] kernel32: Reimplement GetVolumePathName() using NtQueryInformationFile(FileAttributeTagInformation).
Zhiyi Zhang
zzhang at codeweavers.com
Sat Mar 14 23:36:07 CDT 2020
On 3/14/20 11:41 PM, Zebediah Figura wrote:
> Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
> ---
> dlls/kernel32/volume.c | 229 +++++++++++++++++++++--------------------
> 1 file changed, 119 insertions(+), 110 deletions(-)
>
> diff --git a/dlls/kernel32/volume.c b/dlls/kernel32/volume.c
> index 5bfebf60570..6a2e221d579 100644
> --- a/dlls/kernel32/volume.c
> +++ b/dlls/kernel32/volume.c
> @@ -1591,149 +1591,158 @@ BOOL WINAPI GetVolumePathNameA(LPCSTR filename, LPSTR volumepathname, DWORD bufl
> return ret;
> }
>
> +static BOOL is_dos_path( const UNICODE_STRING *path )
> +{
> + static const WCHAR global_prefix[4] = {'\\','?','?','\\'};
> + return path->Length >= 7 * sizeof(WCHAR)
> + && !memcmp(path->Buffer, global_prefix, sizeof(global_prefix))
> + && path->Buffer[5] == ':' && path->Buffer[6] == '\\';
> +}
> +
> +/* resolve all symlinks in a path in-place; return FALSE if allocation failed */
> +static BOOL resolve_symlink( UNICODE_STRING *path )
> +{
> + OBJECT_NAME_INFORMATION *info;
> + OBJECT_ATTRIBUTES attr;
> + IO_STATUS_BLOCK io;
> + NTSTATUS status;
> + HANDLE file;
> + ULONG size;
> +
> + InitializeObjectAttributes( &attr, path, OBJ_CASE_INSENSITIVE, 0, NULL );
> + if (NtOpenFile( &file, SYNCHRONIZE, &attr, &io, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
> + FILE_DIRECTORY_FILE | FILE_SYNCHRONOUS_IO_NONALERT ))
> + return TRUE;
> +
> + if (NtQueryObject( file, ObjectNameInformation, NULL, 0, &size ) != STATUS_INFO_LENGTH_MISMATCH)
> + {
> + NtClose( file );
> + return TRUE;
> + }
> +
> + if (!(info = HeapAlloc( GetProcessHeap(), 0, size )))
> + {
> + NtClose( file );
> + return FALSE;
> + }
> +
> + status = NtQueryObject( file, ObjectNameInformation, info, size, NULL );
> + NtClose( file );
> + if (status)
> + return TRUE;
> +
> + NtClose( file );
NtClose() is called twice.
> + RtlFreeUnicodeString( path );
> + status = RtlDuplicateUnicodeString( 0, &info->Name, path );
> + HeapFree( GetProcessHeap(), 0, info );
> + return !status;
> +}
> +
> /***********************************************************************
> * GetVolumePathNameW (KERNEL32.@)
> - *
> - * This routine is intended to find the most basic path on the same filesystem
> - * for any particular path name. Since we can have very complicated drive/path
> - * relationships on Unix systems, due to symbolic links, the safest way to
> - * handle this is to start with the full path and work our way back folder by
> - * folder unil we find a folder on a different drive (or run out of folders).
> */
> -BOOL WINAPI GetVolumePathNameW(LPCWSTR filename, LPWSTR volumepathname, DWORD buflen)
> +BOOL WINAPI GetVolumePathNameW(const WCHAR *path, WCHAR *volume_path, DWORD length)
> {
> - static const WCHAR deviceprefixW[] = { '\\','?','?','\\',0 };
> - static const WCHAR ntprefixW[] = { '\\','\\','?','\\',0 };
> - WCHAR fallbackpathW[] = { 'C',':','\\',0 };
> - NTSTATUS status = STATUS_SUCCESS;
> - WCHAR *volumenameW = NULL, *c;
> - int pos, last_pos, stop_pos;
> + static const WCHAR device_prefix[4] = {'\\','\\','.','\\'};
> + static const WCHAR device_prefix2[4] = {'\\','\\','?','\\'};
> + static const WCHAR global_prefix[4] = {'\\','?','?','\\'};
> + static const WCHAR dotW[] = {'.',0};
> + FILE_ATTRIBUTE_TAG_INFORMATION attr_info;
> + FILE_BASIC_INFORMATION basic_info;
> + OBJECT_ATTRIBUTES attr;
> UNICODE_STRING nt_name;
> - ANSI_STRING unix_name;
> - BOOL first_run = TRUE;
> - dev_t search_dev = 0;
> - struct stat st;
>
> - TRACE("(%s, %p, %d)\n", debugstr_w(filename), volumepathname, buflen);
> + if (path && !memcmp(path, global_prefix, sizeof(global_prefix)))
> + path = dotW;
>
> - if (!filename || !volumepathname || !buflen)
> + if (!volume_path || !length || !RtlDosPathNameToNtPathName_U( path, &nt_name, NULL, NULL ))
> {
> - SetLastError(ERROR_INVALID_PARAMETER);
> + SetLastError( ERROR_INVALID_PARAMETER );
> return FALSE;
> }
>
> - last_pos = pos = strlenW( filename );
> - /* allocate enough memory for searching the path (need room for a slash and a NULL terminator) */
> - if (!(volumenameW = HeapAlloc( GetProcessHeap(), 0, (pos + 2) * sizeof(WCHAR) )))
> + if (!is_dos_path( &nt_name ))
> {
> - SetLastError( ERROR_NOT_ENOUGH_MEMORY );
> + RtlFreeUnicodeString( &nt_name );
> + WARN("invalid path %s\n", debugstr_w(path));
> + SetLastError( ERROR_INVALID_NAME );
> return FALSE;
> }
> - strcpyW( volumenameW, filename );
> -
> - /* Normalize path */
> - for (c = volumenameW; *c; c++) if (*c == '/') *c = '\\';
>
> - stop_pos = 0;
> - /* stop searching slashes early for NT-type and nearly NT-type paths */
> - if (strncmpW(ntprefixW, filename, strlenW(ntprefixW)) == 0)
> - stop_pos = strlenW(ntprefixW)-1;
> - else if (strncmpW(ntprefixW, filename, 2) == 0)
> - stop_pos = 2;
> + InitializeObjectAttributes( &attr, &nt_name, OBJ_CASE_INSENSITIVE, 0, NULL );
>
> - do
> + while (nt_name.Length > 7 * sizeof(WCHAR))
> {
> - volumenameW[pos+0] = '\\';
> - volumenameW[pos+1] = '\0';
> - if (!RtlDosPathNameToNtPathName_U( volumenameW, &nt_name, NULL, NULL ))
> - goto cleanup;
> - volumenameW[pos] = '\0';
> - status = wine_nt_to_unix_file_name( &nt_name, &unix_name, FILE_OPEN, FALSE );
> - RtlFreeUnicodeString( &nt_name );
> - if (status == STATUS_SUCCESS)
> + IO_STATUS_BLOCK io;
> + HANDLE file;
> +
> + if (!NtQueryAttributesFile( &attr, &basic_info )
> + && (basic_info.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)
> + && (basic_info.FileAttributes & FILE_ATTRIBUTE_DIRECTORY)
> + && !NtOpenFile( &file, SYNCHRONIZE | FILE_READ_ATTRIBUTES, &attr, &io,
> + FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
> + FILE_OPEN_REPARSE_POINT | FILE_DIRECTORY_FILE | FILE_SYNCHRONOUS_IO_NONALERT ))
> {
> - if (stat( unix_name.Buffer, &st ) != 0)
> - {
> - RtlFreeAnsiString( &unix_name );
> - status = STATUS_OBJECT_NAME_INVALID;
> - goto cleanup;
> - }
> - if (first_run)
> - {
> - first_run = FALSE;
> - search_dev = st.st_dev;
> - }
> - else if (st.st_dev != search_dev)
> + if (!NtQueryInformationFile( file, &io, &attr_info, sizeof(attr_info), FileAttributeTagInformation ))
> {
> - /* folder is on a new filesystem, return the last folder */
> - RtlFreeAnsiString( &unix_name );
> - break;
> + NtClose( file );
> +
> + if (attr_info.ReparseTag == IO_REPARSE_TAG_MOUNT_POINT)
> + break;
> +
> + if (!resolve_symlink( &nt_name ))
> + {
> + SetLastError( ERROR_OUTOFMEMORY );
> + return FALSE;
> + }
> }
> + NtClose( file );
> }
> - RtlFreeAnsiString( &unix_name );
> - last_pos = pos;
> - c = strrchrW( volumenameW, '\\' );
> - if (c != NULL)
> - pos = c-volumenameW;
> - } while (c != NULL && pos > stop_pos);
>
> - if (status != STATUS_SUCCESS)
> + if (nt_name.Buffer[(nt_name.Length / sizeof(WCHAR)) - 1] == '\\')
> + nt_name.Length -= sizeof(WCHAR);
> + while (nt_name.Length && nt_name.Buffer[(nt_name.Length / sizeof(WCHAR)) - 1] != '\\')
> + nt_name.Length -= sizeof(WCHAR);
> + }
> +
> + nt_name.Buffer[nt_name.Length / sizeof(WCHAR)] = 0;
> +
> + if (NtQueryAttributesFile( &attr, &basic_info ))
> {
> - WCHAR cwdW[MAX_PATH];
> + RtlFreeUnicodeString( &nt_name );
> + WARN("nonexistent path %s -> %s\n", debugstr_w(path), debugstr_w( nt_name.Buffer ));
> + SetLastError( ERROR_FILE_NOT_FOUND );
> + return FALSE;
> + }
>
> - /* the path was completely invalid */
> - if (filename[0] == '\\' && strncmpW(deviceprefixW, filename, strlenW(deviceprefixW)) != 0)
> + if (!memcmp(path, device_prefix, sizeof(device_prefix))
> + || !memcmp(path, device_prefix2, sizeof(device_prefix2)))
> + {
> + if (length >= nt_name.Length / sizeof(WCHAR))
> {
> - /* NT-style paths (that are not device paths) fail */
> - status = STATUS_OBJECT_NAME_INVALID;
> - goto cleanup;
> - }
> + memcpy(volume_path, path, 4 * sizeof(WCHAR));
> + lstrcpynW( volume_path + 4, nt_name.Buffer + 4, length - 4 );
>
> - /* DOS-style paths (anything not beginning with a slash) have fallback replies */
> - if (filename[1] == ':')
> - {
> - /* if the path is semi-sane (X:) then use the given drive letter (if it is mounted) */
> - fallbackpathW[0] = filename[0];
> - if (!isalphaW(filename[0]) || GetDriveTypeW( fallbackpathW ) == DRIVE_NO_ROOT_DIR)
> - {
> - status = STATUS_OBJECT_NAME_NOT_FOUND;
> - goto cleanup;
> - }
> - }
> - else if (GetCurrentDirectoryW(ARRAY_SIZE(cwdW), cwdW ))
> - {
> - /* if the path is completely bogus then revert to the drive of the working directory */
> - fallbackpathW[0] = cwdW[0];
> - }
> - else
> - {
> - status = STATUS_OBJECT_NAME_INVALID;
> - goto cleanup;
> + TRACE("%s -> %s\n", debugstr_w(path), debugstr_w(volume_path));
> +
> + RtlFreeUnicodeString( &nt_name );
> + return TRUE;
> }
> - last_pos = strlenW(fallbackpathW) - 1; /* points to \\ */
> - filename = fallbackpathW;
> - status = STATUS_SUCCESS;
> }
> -
> - if (last_pos + 1 <= buflen)
> + else if (length >= (nt_name.Length / sizeof(WCHAR)) - 4)
> {
> - memcpy(volumepathname, filename, last_pos * sizeof(WCHAR));
> - if (last_pos + 2 <= buflen) volumepathname[last_pos++] = '\\';
> - volumepathname[last_pos] = '\0';
> + lstrcpynW( volume_path, nt_name.Buffer + 4, length );
> + volume_path[0] = toupperW(volume_path[0]);
>
> - /* DOS-style paths always return upper-case drive letters */
> - if (volumepathname[1] == ':')
> - volumepathname[0] = toupperW(volumepathname[0]);
> + TRACE("%s -> %s\n", debugstr_w(path), debugstr_w(volume_path));
>
> - TRACE("Successfully translated path %s to mount-point %s\n",
> - debugstr_w(filename), debugstr_w(volumepathname));
> + RtlFreeUnicodeString( &nt_name );
> + return TRUE;
> }
> - else
> - status = STATUS_NAME_TOO_LONG;
>
> -cleanup:
> - HeapFree( GetProcessHeap(), 0, volumenameW );
> - return set_ntstatus( status );
> + RtlFreeUnicodeString( &nt_name );
> + SetLastError( ERROR_FILENAME_EXCED_RANGE );
> + return FALSE;
> }
>
>
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