extensions/common/extension_api.cc

   1 // Copyright 2013 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 #include "extensions/common/extension_api.h"
   6
   7 #include <algorithm>
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/json/json_reader.h"
  12 #include "base/json/json_writer.h"
  13 #include "base/lazy_instance.h"
  14 #include "base/logging.h"
  15 #include "base/strings/string_number_conversions.h"
  16 #include "base/strings/string_split.h"
  17 #include "base/strings/string_util.h"
  18 #include "base/values.h"
  19 #include "extensions/common/extension.h"
  20 #include "extensions/common/extensions_client.h"
  21 #include "extensions/common/features/feature.h"
  22 #include "extensions/common/features/feature_provider.h"
  23 #include "extensions/common/features/simple_feature.h"
  24 #include "extensions/common/permissions/permission_set.h"
  25 #include "extensions/common/permissions/permissions_data.h"
  26 #include "extensions/grit/extensions_resources.h"
  27 #include "ui/base/resource/resource_bundle.h"
  28 #include "url/gurl.h"
  29
  30 namespace extensions {
  31
  32 namespace {
  33
  34 const char* kChildKinds[] = {
  35   "functions",
  36   "events"
  37 };
  38
  39 base::StringPiece ReadFromResource(int resource_id) {
  40   return ResourceBundle::GetSharedInstance().GetRawDataResource(
  41       resource_id);
  42 }
  43
  44 scoped_ptr<base::ListValue> LoadSchemaList(const std::string& name,
  45                                            const base::StringPiece& schema) {
  46   std::string error_message;
  47   scoped_ptr<base::Value> result(
  48       base::JSONReader::ReadAndReturnError(
  49           schema,
  50           base::JSON_PARSE_RFC | base::JSON_DETACHABLE_CHILDREN,  // options
  51           NULL,  // error code
  52           &error_message));
  53
  54   // Tracking down http://crbug.com/121424
  55   char buf[128];
  56   base::snprintf(buf, arraysize(buf), "%s: (%d) '%s'",
  57       name.c_str(),
  58       result.get() ? result->GetType() : -1,
  59       error_message.c_str());
  60
  61   CHECK(result.get()) << error_message << " for schema " << schema;
  62   CHECK(result->IsType(base::Value::TYPE_LIST)) << " for schema " << schema;
  63   return scoped_ptr<base::ListValue>(static_cast<base::ListValue*>(
  64       result.release()));
  65 }
  66
  67 const base::DictionaryValue* FindListItem(const base::ListValue* list,
  68                                           const std::string& property_name,
  69                                           const std::string& property_value) {
  70   for (size_t i = 0; i < list->GetSize(); ++i) {
  71     const base::DictionaryValue* item = NULL;
  72     CHECK(list->GetDictionary(i, &item))
  73         << property_value << "/" << property_name;
  74     std::string value;
  75     if (item->GetString(property_name, &value) && value == property_value)
  76       return item;
  77   }
  78
  79   return NULL;
  80 }
  81
  82 const base::DictionaryValue* GetSchemaChild(
  83     const base::DictionaryValue* schema_node,
  84     const std::string& child_name) {
  85   const base::DictionaryValue* child_node = NULL;
  86   for (size_t i = 0; i < arraysize(kChildKinds); ++i) {
  87     const base::ListValue* list_node = NULL;
  88     if (!schema_node->GetList(kChildKinds[i], &list_node))
  89       continue;
  90     child_node = FindListItem(list_node, "name", child_name);
  91     if (child_node)
  92       return child_node;
  93   }
  94
  95   return NULL;
  96 }
  97
  98 struct Static {
  99   Static()
 100       : api(ExtensionAPI::CreateWithDefaultConfiguration()) {
 101   }
 102   scoped_ptr<ExtensionAPI> api;
 103 };
 104
 105 base::LazyInstance<Static> g_lazy_instance = LAZY_INSTANCE_INITIALIZER;
 106
 107 // May override |g_lazy_instance| for a test.
 108 ExtensionAPI* g_shared_instance_for_test = NULL;
 109
 110 // If it exists and does not already specify a namespace, then the value stored
 111 // with key |key| in |schema| will be updated to |schema_namespace| + "." +
 112 // |schema[key]|.
 113 void MaybePrefixFieldWithNamespace(const std::string& schema_namespace,
 114                                    base::DictionaryValue* schema,
 115                                    const std::string& key) {
 116   if (!schema->HasKey(key))
 117     return;
 118
 119   std::string old_id;
 120   CHECK(schema->GetString(key, &old_id));
 121   if (old_id.find(".") == std::string::npos)
 122     schema->SetString(key, schema_namespace + "." + old_id);
 123 }
 124
 125 // Modify all "$ref" keys anywhere in |schema| to be prefxied by
 126 // |schema_namespace| if they do not already specify a namespace.
 127 void PrefixRefsWithNamespace(const std::string& schema_namespace,
 128                              base::Value* value) {
 129   base::ListValue* list = NULL;
 130   base::DictionaryValue* dict = NULL;
 131   if (value->GetAsList(&list)) {
 132     for (base::ListValue::iterator i = list->begin(); i != list->end(); ++i) {
 133       PrefixRefsWithNamespace(schema_namespace, *i);
 134     }
 135   } else if (value->GetAsDictionary(&dict)) {
 136     MaybePrefixFieldWithNamespace(schema_namespace, dict, "$ref");
 137     for (base::DictionaryValue::Iterator i(*dict); !i.IsAtEnd(); i.Advance()) {
 138       base::Value* value = NULL;
 139       CHECK(dict->GetWithoutPathExpansion(i.key(), &value));
 140       PrefixRefsWithNamespace(schema_namespace, value);
 141     }
 142   }
 143 }
 144
 145 // Modify all objects in the "types" section of the schema to be prefixed by
 146 // |schema_namespace| if they do not already specify a namespace.
 147 void PrefixTypesWithNamespace(const std::string& schema_namespace,
 148                               base::DictionaryValue* schema) {
 149   if (!schema->HasKey("types"))
 150     return;
 151
 152   // Add the namespace to all of the types defined in this schema
 153   base::ListValue *types = NULL;
 154   CHECK(schema->GetList("types", &types));
 155   for (size_t i = 0; i < types->GetSize(); ++i) {
 156     base::DictionaryValue *type = NULL;
 157     CHECK(types->GetDictionary(i, &type));
 158     MaybePrefixFieldWithNamespace(schema_namespace, type, "id");
 159     MaybePrefixFieldWithNamespace(schema_namespace, type, "customBindings");
 160   }
 161 }
 162
 163 // Modify the schema so that all types are fully qualified.
 164 void PrefixWithNamespace(const std::string& schema_namespace,
 165                          base::DictionaryValue* schema) {
 166   PrefixTypesWithNamespace(schema_namespace, schema);
 167   PrefixRefsWithNamespace(schema_namespace, schema);
 168 }
 169
 170 }  // namespace
 171
 172 // static
 173 ExtensionAPI* ExtensionAPI::GetSharedInstance() {
 174   return g_shared_instance_for_test ? g_shared_instance_for_test
 175                                     : g_lazy_instance.Get().api.get();
 176 }
 177
 178 // static
 179 ExtensionAPI* ExtensionAPI::CreateWithDefaultConfiguration() {
 180   ExtensionAPI* api = new ExtensionAPI();
 181   api->InitDefaultConfiguration();
 182   return api;
 183 }
 184
 185 // static
 186 void ExtensionAPI::SplitDependencyName(const std::string& full_name,
 187                                        std::string* feature_type,
 188                                        std::string* feature_name) {
 189   size_t colon_index = full_name.find(':');
 190   if (colon_index == std::string::npos) {
 191     // TODO(aa): Remove this code when all API descriptions have been updated.
 192     *feature_type = "api";
 193     *feature_name = full_name;
 194     return;
 195   }
 196
 197   *feature_type = full_name.substr(0, colon_index);
 198   *feature_name = full_name.substr(colon_index + 1);
 199 }
 200
 201 ExtensionAPI::OverrideSharedInstanceForTest::OverrideSharedInstanceForTest(
 202     ExtensionAPI* testing_api)
 203     : original_api_(g_shared_instance_for_test) {
 204   g_shared_instance_for_test = testing_api;
 205 }
 206
 207 ExtensionAPI::OverrideSharedInstanceForTest::~OverrideSharedInstanceForTest() {
 208   g_shared_instance_for_test = original_api_;
 209 }
 210
 211 void ExtensionAPI::LoadSchema(const std::string& name,
 212                               const base::StringPiece& schema) {
 213   scoped_ptr<base::ListValue> schema_list(LoadSchemaList(name, schema));
 214   std::string schema_namespace;
 215   extensions::ExtensionsClient* extensions_client =
 216       extensions::ExtensionsClient::Get();
 217   DCHECK(extensions_client);
 218   while (!schema_list->empty()) {
 219     base::DictionaryValue* schema = NULL;
 220     {
 221       scoped_ptr<base::Value> value;
 222       schema_list->Remove(schema_list->GetSize() - 1, &value);
 223       CHECK(value.release()->GetAsDictionary(&schema));
 224     }
 225
 226     CHECK(schema->GetString("namespace", &schema_namespace));
 227     PrefixWithNamespace(schema_namespace, schema);
 228     schemas_[schema_namespace] = make_linked_ptr(schema);
 229     if (!extensions_client->IsAPISchemaGenerated(schema_namespace))
 230       CHECK_EQ(1u, unloaded_schemas_.erase(schema_namespace));
 231   }
 232 }
 233
 234 ExtensionAPI::ExtensionAPI() : default_configuration_initialized_(false) {
 235 }
 236
 237 ExtensionAPI::~ExtensionAPI() {
 238 }
 239
 240 void ExtensionAPI::InitDefaultConfiguration() {
 241   const char* names[] = {"api", "manifest", "permission"};
 242   for (size_t i = 0; i < arraysize(names); ++i)
 243     RegisterDependencyProvider(names[i], FeatureProvider::GetByName(names[i]));
 244
 245   ExtensionsClient::Get()->RegisterAPISchemaResources(this);
 246
 247   RegisterSchemaResource("declarativeWebRequest",
 248                          IDR_EXTENSION_API_JSON_DECLARATIVE_WEBREQUEST);
 249   RegisterSchemaResource("webViewRequest",
 250                          IDR_EXTENSION_API_JSON_WEB_VIEW_REQUEST);
 251
 252   default_configuration_initialized_ = true;
 253 }
 254
 255 void ExtensionAPI::RegisterSchemaResource(const std::string& name,
 256                                           int resource_id) {
 257   unloaded_schemas_[name] = resource_id;
 258 }
 259
 260 void ExtensionAPI::RegisterDependencyProvider(const std::string& name,
 261                                               const FeatureProvider* provider) {
 262   dependency_providers_[name] = provider;
 263 }
 264
 265 bool ExtensionAPI::IsAnyFeatureAvailableToContext(const Feature& api,
 266                                                   const Extension* extension,
 267                                                   Feature::Context context,
 268                                                   const GURL& url) {
 269   FeatureProviderMap::iterator provider = dependency_providers_.find("api");
 270   CHECK(provider != dependency_providers_.end());
 271
 272   if (api.IsAvailableToContext(extension, context, url).is_available())
 273     return true;
 274
 275   // Check to see if there are any parts of this API that are allowed in this
 276   // context.
 277   const std::vector<Feature*> features = provider->second->GetChildren(api);
 278   for (std::vector<Feature*>::const_iterator it = features.begin();
 279        it != features.end();
 280        ++it) {
 281     if ((*it)->IsAvailableToContext(extension, context, url).is_available())
 282       return true;
 283   }
 284   return false;
 285 }
 286
 287 Feature::Availability ExtensionAPI::IsAvailable(const std::string& full_name,
 288                                                 const Extension* extension,
 289                                                 Feature::Context context,
 290                                                 const GURL& url) {
 291   Feature* feature = GetFeatureDependency(full_name);
 292   if (!feature) {
 293     return Feature::Availability(Feature::NOT_PRESENT,
 294                                  std::string("Unknown feature: ") + full_name);
 295   }
 296   return feature->IsAvailableToContext(extension, context, url);
 297 }
 298
 299 bool ExtensionAPI::IsAvailableToWebUI(const std::string& name,
 300                                       const GURL& url) {
 301   return IsAvailable(name, NULL, Feature::WEBUI_CONTEXT, url).is_available();
 302 }
 303
 304 const base::DictionaryValue* ExtensionAPI::GetSchema(
 305     const std::string& full_name) {
 306   std::string child_name;
 307   std::string api_name = GetAPINameFromFullName(full_name, &child_name);
 308
 309   const base::DictionaryValue* result = NULL;
 310   SchemaMap::iterator maybe_schema = schemas_.find(api_name);
 311   if (maybe_schema != schemas_.end()) {
 312     result = maybe_schema->second.get();
 313   } else {
 314     // Might not have loaded yet; or might just not exist.
 315     UnloadedSchemaMap::iterator maybe_schema_resource =
 316         unloaded_schemas_.find(api_name);
 317     extensions::ExtensionsClient* extensions_client =
 318         extensions::ExtensionsClient::Get();
 319     DCHECK(extensions_client);
 320     if (maybe_schema_resource != unloaded_schemas_.end()) {
 321       LoadSchema(maybe_schema_resource->first,
 322                  ReadFromResource(maybe_schema_resource->second));
 323     } else if (default_configuration_initialized_ &&
 324                extensions_client->IsAPISchemaGenerated(api_name)) {
 325       LoadSchema(api_name, extensions_client->GetAPISchema(api_name));
 326     } else {
 327       return NULL;
 328     }
 329
 330     maybe_schema = schemas_.find(api_name);
 331     CHECK(schemas_.end() != maybe_schema);
 332     result = maybe_schema->second.get();
 333   }
 334
 335   if (!child_name.empty())
 336     result = GetSchemaChild(result, child_name);
 337
 338   return result;
 339 }
 340
 341 Feature* ExtensionAPI::GetFeatureDependency(const std::string& full_name) {
 342   std::string feature_type;
 343   std::string feature_name;
 344   SplitDependencyName(full_name, &feature_type, &feature_name);
 345
 346   FeatureProviderMap::iterator provider =
 347       dependency_providers_.find(feature_type);
 348   if (provider == dependency_providers_.end())
 349     return NULL;
 350
 351   Feature* feature = provider->second->GetFeature(feature_name);
 352   // Try getting the feature for the parent API, if this was a child.
 353   if (!feature) {
 354     std::string child_name;
 355     feature = provider->second->GetFeature(
 356         GetAPINameFromFullName(feature_name, &child_name));
 357   }
 358   return feature;
 359 }
 360
 361 std::string ExtensionAPI::GetAPINameFromFullName(const std::string& full_name,
 362                                                  std::string* child_name) {
 363   std::string api_name_candidate = full_name;
 364   extensions::ExtensionsClient* extensions_client =
 365       extensions::ExtensionsClient::Get();
 366   DCHECK(extensions_client);
 367   while (true) {
 368     if (schemas_.find(api_name_candidate) != schemas_.end() ||
 369         extensions_client->IsAPISchemaGenerated(api_name_candidate) ||
 370         unloaded_schemas_.find(api_name_candidate) != unloaded_schemas_.end()) {
 371       std::string result = api_name_candidate;
 372
 373       if (child_name) {
 374         if (result.length() < full_name.length())
 375           *child_name = full_name.substr(result.length() + 1);
 376         else
 377           *child_name = "";
 378       }
 379
 380       return result;
 381     }
 382
 383     size_t last_dot_index = api_name_candidate.rfind('.');
 384     if (last_dot_index == std::string::npos)
 385       break;
 386
 387     api_name_candidate = api_name_candidate.substr(0, last_dot_index);
 388   }
 389
 390   *child_name = "";
 391   return std::string();
 392 }
 393
 394 }  // namespace extensions