win, fs: add IO_REPARSE_TAG_APPEXECLINK support

Adds support for IO_REPARSE_TAG_APPEXECLINK reparse points, used by
Windows Store.

Ref: nodejs/node#33024

src/win/error.c

@@ -72,6 +72,7 @@ int uv_translate_sys_error(int sys_errno) {
     case ERROR_NOACCESS:                    return UV_EACCES;
     case WSAEACCES:                         return UV_EACCES;
     case ERROR_ELEVATION_REQUIRED:          return UV_EACCES;
+    case ERROR_CANT_ACCESS_FILE:            return UV_EACCES;
     case ERROR_ADDRESS_ALREADY_ASSOCIATED:  return UV_EADDRINUSE;
     case WSAEADDRINUSE:                     return UV_EADDRINUSE;
     case WSAEADDRNOTAVAIL:                  return UV_EADDRNOTAVAIL;

src/win/fs.c

@@ -321,6 +321,7 @@ INLINE static int fs__readlink_handle(HANDLE handle, char** target_ptr,
   WCHAR* w_target;
   DWORD w_target_len;
   DWORD bytes;
+  size_t i, len;
 
   if (!DeviceIoControl(handle,
                        FSCTL_GET_REPARSE_POINT,
@@ -405,6 +406,38 @@ INLINE static int fs__readlink_handle(HANDLE handle, char** target_ptr,
     w_target += 4;
     w_target_len -= 4;
 
+  } else if (reparse_data->ReparseTag == IO_REPARSE_TAG_APPEXECLINK) {
+    /* String #3 in the list has the target filename. */
+    if (reparse_data->AppExecLinkReparseBuffer.StringCount < 3) {
+      SetLastError(ERROR_SYMLINK_NOT_SUPPORTED);
+      return -1;
+    }
+    w_target = reparse_data->AppExecLinkReparseBuffer.StringList;
+    /* The StringList buffer contains a list of strings separated by "\0",   */
+    /* with "\0\0" terminating the list. Move to the 3rd string in the list: */
+    for (i = 0; i < 2; ++i) {
+      len = wcslen(w_target);
+      if (len == 0) {
+        SetLastError(ERROR_SYMLINK_NOT_SUPPORTED);
+        return -1;
+      }
+      w_target += len + 1;
+    }
+    w_target_len = wcslen(w_target);
+    if (w_target_len == 0) {
+      SetLastError(ERROR_SYMLINK_NOT_SUPPORTED);
+      return -1;
+    }
+    /* Make sure it is an absolute path. */
+    if (!(w_target_len >= 3 &&
+         ((w_target[0] >= L'a' && w_target[0] <= L'z') ||
+          (w_target[0] >= L'A' && w_target[0] <= L'Z')) &&
+         w_target[1] == L':' &&
+         w_target[2] == L'\\')) {
+      SetLastError(ERROR_SYMLINK_NOT_SUPPORTED);
+      return -1;
+    }
+
   } else {
     /* Reparse tag does not indicate a symlink. */
     SetLastError(ERROR_SYMLINK_NOT_SUPPORTED);

src/win/winapi.h

@@ -4152,6 +4152,10 @@ typedef const UNICODE_STRING *PCUNICODE_STRING;
       struct {
         UCHAR  DataBuffer[1];
       } GenericReparseBuffer;
+      struct {
+        ULONG StringCount;
+        WCHAR StringList[1];
+      } AppExecLinkReparseBuffer;
     };
   } REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;
 #endif

test/test-fs.c

@@ -2453,6 +2453,49 @@ TEST_IMPL(fs_non_symlink_reparse_point) {
   MAKE_VALGRIND_HAPPY();
   return 0;
 }
+
+TEST_IMPL(fs_lstat_windows_store_apps) {
+  uv_loop_t* loop;
+  char localappdata[MAX_PATH];
+  char windowsapps_path[MAX_PATH];
+  char file_path[MAX_PATH];
+  size_t len;
+  int r;
+  uv_fs_t req, stat_req;
+  uv_dirent_t dirent;
+
+  loop = uv_default_loop();
+  ASSERT(loop != NULL);
+  len = MAX_PATH;
+  r = uv_os_getenv("LOCALAPPDATA", localappdata, &len);
+  if (r == UV_ENOENT) {
+    return TEST_SKIP;
+  }
+  ASSERT(r == 0);
+  r = sprintf_s(windowsapps_path,
+                MAX_PATH,
+                "%s\\Microsoft\\WindowsApps",
+                localappdata);
+  ASSERT(r > 0);
+  if (uv_fs_opendir(loop, &req, windowsapps_path, NULL) != 0) {
+    /* If we cannot read the directory, skip the test. */
+    return TEST_SKIP;
+  }
+  if (uv_fs_scandir(loop, &req, windowsapps_path, 0, NULL) <= 0) {
+    return TEST_SKIP;
+  }
+  while (uv_fs_scandir_next(&req, &dirent) != UV_EOF) {
+    if (dirent.type != UV_DIRENT_LINK) {
+      continue;
+    }
+    if (sprintf_s(file_path, MAX_PATH, "%s\\%s", windowsapps_path, dirent.name) < 0) {
+      continue;
+    }
+
+    ASSERT(uv_fs_lstat(loop, &stat_req, file_path, NULL) == 0);
+  }
+  return 0;
+}
 #endif
 
 

test/test-list.h

@@ -346,6 +346,7 @@ TEST_DECLARE   (fs_symlink_dir)
 #ifdef _WIN32
 TEST_DECLARE   (fs_symlink_junction)
 TEST_DECLARE   (fs_non_symlink_reparse_point)
+TEST_DECLARE   (fs_lstat_windows_store_apps)
 TEST_DECLARE   (fs_open_flags)
 #endif
 #if defined(_WIN32) && !defined(USING_UV_SHARED)
@@ -978,6 +979,7 @@ TASK_LIST_START
 #ifdef _WIN32
   TEST_ENTRY  (fs_symlink_junction)
   TEST_ENTRY  (fs_non_symlink_reparse_point)
+  TEST_ENTRY  (fs_lstat_windows_store_apps)
   TEST_ENTRY  (fs_open_flags)
 #endif
 #if defined(_WIN32) && !defined(USING_UV_SHARED)