extensions/common/extension_resource.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef EXTENSIONS_COMMON_EXTENSION_RESOURCE_H_
   6 #define EXTENSIONS_COMMON_EXTENSION_RESOURCE_H_
   7
   8 #include <string>
   9
  10 #include "base/files/file_path.h"
  11
  12 namespace extensions {
  13
  14 // Represents a resource inside an extension. For example, an image, or a
  15 // JavaScript file. This is more complicated than just a simple FilePath
  16 // because extension resources can come from multiple physical file locations
  17 // depending on locale.
  18 class ExtensionResource {
  19  public:
  20   // SymlinkPolicy decides whether we'll allow resources to be a symlink to
  21   // anywhere, or whether they must end up within the extension root.
  22   enum SymlinkPolicy {
  23     SYMLINKS_MUST_RESOLVE_WITHIN_ROOT,
  24     FOLLOW_SYMLINKS_ANYWHERE,
  25   };
  26
  27   ExtensionResource();
  28
  29   ExtensionResource(const std::string& extension_id,
  30                     const base::FilePath& extension_root,
  31                     const base::FilePath& relative_path);
  32
  33   ~ExtensionResource();
  34
  35   // set_follow_symlinks_anywhere allows the resource to be a symlink to
  36   // anywhere in the filesystem. By default, resources have to be within
  37   // |extension_root| after resolving symlinks.
  38   void set_follow_symlinks_anywhere();
  39
  40   // Returns actual path to the resource (default or locale specific). In the
  41   // browser process, this will DCHECK if not called on the file thread. To
  42   // easily load extension images on the UI thread, see ImageLoader.
  43   const base::FilePath& GetFilePath() const;
  44
  45   // Gets the physical file path for the extension resource, taking into account
  46   // localization. In the browser process, this will DCHECK if not called on the
  47   // file thread. To easily load extension images on the UI thread, see
  48   // ImageLoader.
  49   //
  50   // The relative path must not resolve to a location outside of
  51   // |extension_root|. Iff |file_can_symlink_outside_root| is true, then the
  52   // file can be a symlink that links outside of |extension_root|.
  53   static base::FilePath GetFilePath(const base::FilePath& extension_root,
  54                                     const base::FilePath& relative_path,
  55                                     SymlinkPolicy symlink_policy);
  56
  57   // Getters
  58   const std::string& extension_id() const { return extension_id_; }
  59   const base::FilePath& extension_root() const { return extension_root_; }
  60   const base::FilePath& relative_path() const { return relative_path_; }
  61
  62   bool empty() const { return extension_root().empty(); }
  63
  64   // Unit test helpers.
  65   base::FilePath::StringType NormalizeSeperators(
  66       const base::FilePath::StringType& path) const;
  67   bool ComparePathWithDefault(const base::FilePath& path) const;
  68
  69  private:
  70   // The id of the extension that this resource is associated with.
  71   std::string extension_id_;
  72
  73   // Extension root.
  74   base::FilePath extension_root_;
  75
  76   // Relative path to resource.
  77   base::FilePath relative_path_;
  78
  79   // If |follow_symlinks_anywhere_| is true then the resource itself must be
  80   // within |extension_root|, but it can be a symlink to a file that is not.
  81   bool follow_symlinks_anywhere_;
  82
  83   // Full path to extension resource. Starts empty.
  84   mutable base::FilePath full_resource_path_;
  85 };
  86
  87 }  // namespace extensions
  88
  89 #endif  // EXTENSIONS_COMMON_EXTENSION_RESOURCE_H_