content/common/plugin_list.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 CONTENT_COMMON_PLUGIN_LIST_H_
   6 #define CONTENT_COMMON_PLUGIN_LIST_H_
   7
   8 #include <set>
   9 #include <string>
  10 #include <utility>
  11 #include <vector>
  12
  13 #include "base/basictypes.h"
  14 #include "base/callback.h"
  15 #include "base/files/file_path.h"
  16 #include "base/lazy_instance.h"
  17 #include "base/synchronization/lock.h"
  18 #include "content/common/content_export.h"
  19 #include "content/public/common/webplugininfo.h"
  20
  21 #if !defined(ENABLE_PLUGINS)
  22 #error "Plugins should be enabled"
  23 #endif
  24
  25 class GURL;
  26
  27 namespace content {
  28
  29 // The PluginList is responsible for loading our NPAPI based plugins. It does
  30 // so in whatever manner is appropriate for the platform. On Windows, it loads
  31 // plugins from a known directory by looking for DLLs which start with "NP",
  32 // and checking to see if they are valid NPAPI libraries. On the Mac, it walks
  33 // the machine-wide and user plugin directories and loads anything that has
  34 // the correct types. On Linux, it walks the plugin directories as well
  35 // (e.g. /usr/lib/browser-plugins/).
  36 // This object is thread safe.
  37 class CONTENT_EXPORT PluginList {
  38  public:
  39   // Gets the one instance of the PluginList.
  40   static PluginList* Singleton();
  41
  42   // Returns true if we're in debug-plugin-loading mode. This is controlled
  43   // by a command line switch.
  44   static bool DebugPluginLoading();
  45
  46   // Returns true if the plugin supports |mime_type|. |mime_type| should be all
  47   // lower case.
  48   static bool SupportsType(const WebPluginInfo& plugin,
  49                            const std::string& mime_type,
  50                            bool allow_wildcard);
  51
  52   // Disables discovery of third_party plugins in standard places next time
  53   // plugins are loaded.
  54   void DisablePluginsDiscovery();
  55
  56   // Cause the plugin list to refresh next time they are accessed, regardless
  57   // of whether they are already loaded.
  58   void RefreshPlugins();
  59
  60   // Add/Remove an extra plugin to load when we actually do the loading.  Must
  61   // be called before the plugins have been loaded.
  62   void AddExtraPluginPath(const base::FilePath& plugin_path);
  63   void RemoveExtraPluginPath(const base::FilePath& plugin_path);
  64
  65   // Same as above, but specifies a directory in which to search for plugins.
  66   void AddExtraPluginDir(const base::FilePath& plugin_dir);
  67
  68   // Get the ordered list of directories from which to load plugins
  69   void GetPluginDirectories(std::vector<base::FilePath>* plugin_dirs);
  70
  71   // Register an internal plugin with the specified plugin information.
  72   // An internal plugin must be registered before it can
  73   // be loaded using PluginList::LoadPlugin().
  74   // If |add_at_beginning| is true the plugin will be added earlier in
  75   // the list so that it can override the MIME types of older registrations.
  76   void RegisterInternalPlugin(const WebPluginInfo& info,
  77                               bool add_at_beginning);
  78
  79   // Removes a specified internal plugin from the list. The search will match
  80   // on the path from the version info previously registered.
  81   void UnregisterInternalPlugin(const base::FilePath& path);
  82
  83   // Gets a list of all the registered internal plugins.
  84   void GetInternalPlugins(std::vector<WebPluginInfo>* plugins);
  85
  86   // Creates a WebPluginInfo structure given a plugin's path.  On success
  87   // returns true, with the information being put into "info".
  88   // Returns false if the library couldn't be found, or if it's not a plugin.
  89   bool ReadPluginInfo(const base::FilePath& filename,
  90                       WebPluginInfo* info);
  91
  92   // In Windows plugins, the mime types are passed as a specially formatted list
  93   // of strings. This function parses those strings into a WebPluginMimeType
  94   // vector.
  95   // TODO(evan): move this code into plugin_list_win.
  96   static bool ParseMimeTypes(
  97       const std::string& mime_types,
  98       const std::string& file_extensions,
  99       const base::string16& mime_type_descriptions,
 100       std::vector<WebPluginMimeType>* parsed_mime_types);
 101
 102   // Get all the plugins synchronously, loading them if necessary.
 103   void GetPlugins(std::vector<WebPluginInfo>* plugins,
 104                   bool include_npapi);
 105
 106   // Copies the list of plugins into |plugins| without loading them.
 107   // Returns true if the list of plugins is up-to-date.
 108   bool GetPluginsNoRefresh(std::vector<WebPluginInfo>* plugins);
 109
 110   // Returns a list in |info| containing plugins that are found for
 111   // the given url and mime type (including disabled plugins, for
 112   // which |info->enabled| is false).  The mime type which corresponds
 113   // to the URL is optionally returned back in |actual_mime_types| (if
 114   // it is non-NULL), one for each of the plugin info objects found.
 115   // The |allow_wildcard| parameter controls whether this function
 116   // returns plugins which support wildcard mime types (* as the mime
 117   // type).  The |info| parameter is required to be non-NULL.  The
 118   // list is in order of "most desirable" to "least desirable".
 119   // If |use_stale| is NULL, this will load the plugin list if necessary.
 120   // If it is not NULL, the plugin list will not be loaded, and |*use_stale|
 121   // will be true iff the plugin list was stale.
 122   void GetPluginInfoArray(const GURL& url,
 123                           const std::string& mime_type,
 124                           bool allow_wildcard,
 125                           bool* use_stale,
 126                           bool include_npapi,
 127                           std::vector<WebPluginInfo>* info,
 128                           std::vector<std::string>* actual_mime_types);
 129
 130   // Load a specific plugin with full path. Return true iff loading the plugin
 131   // was successful.
 132   bool LoadPluginIntoPluginList(const base::FilePath& filename,
 133                                 std::vector<WebPluginInfo>* plugins,
 134                                 WebPluginInfo* plugin_info);
 135
 136   // The following functions are used to support probing for WebPluginInfo
 137   // using a different instance of this class.
 138
 139   // Computes a list of all plugins to potentially load from all sources.
 140   void GetPluginPathsToLoad(std::vector<base::FilePath>* plugin_paths,
 141                             bool include_npapi);
 142
 143   // Signals that plugin loading will start. This method should be called before
 144   // loading plugins with a different instance of this class. Returns false if
 145   // the plugin list is up to date.
 146   // When loading has finished, SetPlugins() should be called with the list of
 147   // plugins.
 148   bool PrepareForPluginLoading();
 149
 150   // Clears the internal list of Plugins and copies them from the vector.
 151   void SetPlugins(const std::vector<WebPluginInfo>& plugins);
 152
 153   void set_will_load_plugins_callback(const base::Closure& callback);
 154
 155   virtual ~PluginList();
 156
 157   // Creates a WebPluginInfo structure given a plugin's path.  On success
 158   // returns true, with the information being put into "info".
 159   // Returns false if the library couldn't be found, or if it's not a plugin.
 160   static bool ReadWebPluginInfo(const base::FilePath& filename,
 161                                 WebPluginInfo* info);
 162
 163  private:
 164   enum LoadingState {
 165     LOADING_STATE_NEEDS_REFRESH,
 166     LOADING_STATE_REFRESHING,
 167     LOADING_STATE_UP_TO_DATE,
 168   };
 169
 170   friend class PluginListTest;
 171   friend struct base::DefaultLazyInstanceTraits<PluginList>;
 172
 173   PluginList();
 174
 175   // Load all plugins from the default plugins directory.
 176   void LoadPlugins(bool include_npapi);
 177
 178   // Walks a directory and produces a list of all the plugins to potentially
 179   // load in that directory.
 180   void GetPluginsInDir(const base::FilePath& path,
 181                        std::vector<base::FilePath>* plugins);
 182
 183   // Returns true if we should load the given plugin, or false otherwise.
 184   // |plugins| is the list of plugins we have crawled in the current plugin
 185   // loading run.
 186   bool ShouldLoadPluginUsingPluginList(const WebPluginInfo& info,
 187                                        std::vector<WebPluginInfo>* plugins);
 188
 189   // Returns true if the given plugin supports a given file extension.
 190   // |extension| should be all lower case. If |mime_type| is not NULL, it will
 191   // be set to the MIME type if found. The MIME type which corresponds to the
 192   // extension is optionally returned back.
 193   bool SupportsExtension(const WebPluginInfo& plugin,
 194                          const std::string& extension,
 195                          std::string* actual_mime_type);
 196
 197   // Removes |plugin_path| from the list of extra plugin paths. Should only be
 198   // called while holding |lock_|.
 199   void RemoveExtraPluginPathLocked(const base::FilePath& plugin_path);
 200
 201   //
 202   // Command-line switches
 203   //
 204
 205 #if defined(OS_WIN)
 206   // Gets plugin paths registered under HKCU\Software\MozillaPlugins and
 207   // HKLM\Software\MozillaPlugins.
 208   void GetPluginPathsFromRegistry(std::vector<base::FilePath>* plugins);
 209 #endif
 210
 211   //
 212   // Internals
 213   //
 214
 215   // States whether we will load the plugin list the next time we try to access
 216   // it, whether we are currently in the process of loading it, or whether we
 217   // consider it up-to-date.
 218   LoadingState loading_state_;
 219
 220   // Extra plugin paths that we want to search when loading.
 221   std::vector<base::FilePath> extra_plugin_paths_;
 222
 223   // Extra plugin directories that we want to search when loading.
 224   std::vector<base::FilePath> extra_plugin_dirs_;
 225
 226   // Holds information about internal plugins.
 227   std::vector<WebPluginInfo> internal_plugins_;
 228
 229   // A list holding all plugins.
 230   std::vector<WebPluginInfo> plugins_list_;
 231
 232   // Callback that is invoked whenever the PluginList will reload the plugins.
 233   base::Closure will_load_plugins_callback_;
 234
 235   // Need synchronization for the above members since this object can be
 236   // accessed on multiple threads.
 237   base::Lock lock_;
 238
 239   // Flag indicating whether third_party plugins will be searched for
 240   // in common places.
 241   bool plugins_discovery_disabled_;
 242
 243   DISALLOW_COPY_AND_ASSIGN(PluginList);
 244 };
 245
 246 }  // namespace content
 247
 248 #endif  // CONTENT_COMMON_PLUGIN_LIST_H_