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      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 "chrome/common/extensions/api/generated_schemas.h"
     20 #include "extensions/common/extension.h"
     21 #include "extensions/common/features/feature.h"
     22 #include "extensions/common/features/feature_provider.h"
     23 #include "extensions/common/permissions/permission_set.h"
     24 #include "extensions/common/permissions/permissions_data.h"
     25 #include "grit/common_resources.h"
     26 #include "grit/extensions_api_resources.h"
     27 #include "ui/base/resource/resource_bundle.h"
     28 #include "url/gurl.h"
     29 
     30 namespace extensions {
     31 
     32 using api::GeneratedSchemas;
     33 
     34 namespace {
     35 
     36 const char* kChildKinds[] = {
     37   "functions",
     38   "events"
     39 };
     40 
     41 base::StringPiece ReadFromResource(int resource_id) {
     42   return ResourceBundle::GetSharedInstance().GetRawDataResource(
     43       resource_id);
     44 }
     45 
     46 scoped_ptr<base::ListValue> LoadSchemaList(const std::string& name,
     47                                            const base::StringPiece& schema) {
     48   std::string error_message;
     49   scoped_ptr<base::Value> result(
     50       base::JSONReader::ReadAndReturnError(
     51           schema,
     52           base::JSON_PARSE_RFC | base::JSON_DETACHABLE_CHILDREN,  // options
     53           NULL,  // error code
     54           &error_message));
     55 
     56   // Tracking down http://crbug.com/121424
     57   char buf[128];
     58   base::snprintf(buf, arraysize(buf), "%s: (%d) '%s'",
     59       name.c_str(),
     60       result.get() ? result->GetType() : -1,
     61       error_message.c_str());
     62 
     63   CHECK(result.get()) << error_message << " for schema " << schema;
     64   CHECK(result->IsType(base::Value::TYPE_LIST)) << " for schema " << schema;
     65   return scoped_ptr<base::ListValue>(static_cast<base::ListValue*>(
     66       result.release()));
     67 }
     68 
     69 const base::DictionaryValue* FindListItem(const base::ListValue* list,
     70                                           const std::string& property_name,
     71                                           const std::string& property_value) {
     72   for (size_t i = 0; i < list->GetSize(); ++i) {
     73     const base::DictionaryValue* item = NULL;
     74     CHECK(list->GetDictionary(i, &item))
     75         << property_value << "/" << property_name;
     76     std::string value;
     77     if (item->GetString(property_name, &value) && value == property_value)
     78       return item;
     79   }
     80 
     81   return NULL;
     82 }
     83 
     84 const base::DictionaryValue* GetSchemaChild(
     85     const base::DictionaryValue* schema_node,
     86     const std::string& child_name) {
     87   const base::DictionaryValue* child_node = NULL;
     88   for (size_t i = 0; i < arraysize(kChildKinds); ++i) {
     89     const base::ListValue* list_node = NULL;
     90     if (!schema_node->GetList(kChildKinds[i], &list_node))
     91       continue;
     92     child_node = FindListItem(list_node, "name", child_name);
     93     if (child_node)
     94       return child_node;
     95   }
     96 
     97   return NULL;
     98 }
     99 
    100 struct Static {
    101   Static()
    102       : api(ExtensionAPI::CreateWithDefaultConfiguration()) {
    103   }
    104   scoped_ptr<ExtensionAPI> api;
    105 };
    106 
    107 base::LazyInstance<Static> g_lazy_instance = LAZY_INSTANCE_INITIALIZER;
    108 
    109 // If it exists and does not already specify a namespace, then the value stored
    110 // with key |key| in |schema| will be updated to |schema_namespace| + "." +
    111 // |schema[key]|.
    112 void MaybePrefixFieldWithNamespace(const std::string& schema_namespace,
    113                                    base::DictionaryValue* schema,
    114                                    const std::string& key) {
    115   if (!schema->HasKey(key))
    116     return;
    117 
    118   std::string old_id;
    119   CHECK(schema->GetString(key, &old_id));
    120   if (old_id.find(".") == std::string::npos)
    121     schema->SetString(key, schema_namespace + "." + old_id);
    122 }
    123 
    124 // Modify all "$ref" keys anywhere in |schema| to be prefxied by
    125 // |schema_namespace| if they do not already specify a namespace.
    126 void PrefixRefsWithNamespace(const std::string& schema_namespace,
    127                              base::Value* value) {
    128   base::ListValue* list = NULL;
    129   base::DictionaryValue* dict = NULL;
    130   if (value->GetAsList(&list)) {
    131     for (base::ListValue::iterator i = list->begin(); i != list->end(); ++i) {
    132       PrefixRefsWithNamespace(schema_namespace, *i);
    133     }
    134   } else if (value->GetAsDictionary(&dict)) {
    135     MaybePrefixFieldWithNamespace(schema_namespace, dict, "$ref");
    136     for (base::DictionaryValue::Iterator i(*dict); !i.IsAtEnd(); i.Advance()) {
    137       base::Value* value = NULL;
    138       CHECK(dict->GetWithoutPathExpansion(i.key(), &value));
    139       PrefixRefsWithNamespace(schema_namespace, value);
    140     }
    141   }
    142 }
    143 
    144 // Modify all objects in the "types" section of the schema to be prefixed by
    145 // |schema_namespace| if they do not already specify a namespace.
    146 void PrefixTypesWithNamespace(const std::string& schema_namespace,
    147                               base::DictionaryValue* schema) {
    148   if (!schema->HasKey("types"))
    149     return;
    150 
    151   // Add the namespace to all of the types defined in this schema
    152   base::ListValue *types = NULL;
    153   CHECK(schema->GetList("types", &types));
    154   for (size_t i = 0; i < types->GetSize(); ++i) {
    155     base::DictionaryValue *type = NULL;
    156     CHECK(types->GetDictionary(i, &type));
    157     MaybePrefixFieldWithNamespace(schema_namespace, type, "id");
    158     MaybePrefixFieldWithNamespace(schema_namespace, type, "customBindings");
    159   }
    160 }
    161 
    162 // Modify the schema so that all types are fully qualified.
    163 void PrefixWithNamespace(const std::string& schema_namespace,
    164                          base::DictionaryValue* schema) {
    165   PrefixTypesWithNamespace(schema_namespace, schema);
    166   PrefixRefsWithNamespace(schema_namespace, schema);
    167 }
    168 
    169 }  // namespace
    170 
    171 // static
    172 ExtensionAPI* ExtensionAPI::GetSharedInstance() {
    173   return g_lazy_instance.Get().api.get();
    174 }
    175 
    176 // static
    177 ExtensionAPI* ExtensionAPI::CreateWithDefaultConfiguration() {
    178   ExtensionAPI* api = new ExtensionAPI();
    179   api->InitDefaultConfiguration();
    180   return api;
    181 }
    182 
    183 // static
    184 void ExtensionAPI::SplitDependencyName(const std::string& full_name,
    185                                        std::string* feature_type,
    186                                        std::string* feature_name) {
    187   size_t colon_index = full_name.find(':');
    188   if (colon_index == std::string::npos) {
    189     // TODO(aa): Remove this code when all API descriptions have been updated.
    190     *feature_type = "api";
    191     *feature_name = full_name;
    192     return;
    193   }
    194 
    195   *feature_type = full_name.substr(0, colon_index);
    196   *feature_name = full_name.substr(colon_index + 1);
    197 }
    198 
    199 void ExtensionAPI::LoadSchema(const std::string& name,
    200                               const base::StringPiece& schema) {
    201   scoped_ptr<base::ListValue> schema_list(LoadSchemaList(name, schema));
    202   std::string schema_namespace;
    203 
    204   while (!schema_list->empty()) {
    205     base::DictionaryValue* schema = NULL;
    206     {
    207       scoped_ptr<base::Value> value;
    208       schema_list->Remove(schema_list->GetSize() - 1, &value);
    209       CHECK(value.release()->GetAsDictionary(&schema));
    210     }
    211 
    212     CHECK(schema->GetString("namespace", &schema_namespace));
    213     PrefixWithNamespace(schema_namespace, schema);
    214     schemas_[schema_namespace] = make_linked_ptr(schema);
    215     if (!GeneratedSchemas::IsGenerated(schema_namespace))
    216       CHECK_EQ(1u, unloaded_schemas_.erase(schema_namespace));
    217   }
    218 }
    219 
    220 ExtensionAPI::ExtensionAPI() : default_configuration_initialized_(false) {
    221 }
    222 
    223 ExtensionAPI::~ExtensionAPI() {
    224 }
    225 
    226 void ExtensionAPI::InitDefaultConfiguration() {
    227   const char* names[] = {"api", "manifest", "permission"};
    228   for (size_t i = 0; i < arraysize(names); ++i)
    229     RegisterDependencyProvider(names[i], FeatureProvider::GetByName(names[i]));
    230 
    231   // Schemas to be loaded from resources.
    232   CHECK(unloaded_schemas_.empty());
    233   RegisterSchemaResource("app", IDR_EXTENSION_API_JSON_APP);
    234   RegisterSchemaResource("browserAction", IDR_EXTENSION_API_JSON_BROWSERACTION);
    235   RegisterSchemaResource("browsingData", IDR_EXTENSION_API_JSON_BROWSINGDATA);
    236   RegisterSchemaResource("commands", IDR_EXTENSION_API_JSON_COMMANDS);
    237   RegisterSchemaResource("declarativeContent",
    238       IDR_EXTENSION_API_JSON_DECLARATIVE_CONTENT);
    239   RegisterSchemaResource("declarativeWebRequest",
    240       IDR_EXTENSION_API_JSON_DECLARATIVE_WEBREQUEST);
    241   RegisterSchemaResource("runtime", IDR_EXTENSION_API_JSON_RUNTIME);
    242   RegisterSchemaResource("fileBrowserHandler",
    243       IDR_EXTENSION_API_JSON_FILEBROWSERHANDLER);
    244   RegisterSchemaResource("inputMethodPrivate",
    245       IDR_EXTENSION_API_JSON_INPUTMETHODPRIVATE);
    246   RegisterSchemaResource("pageAction", IDR_EXTENSION_API_JSON_PAGEACTION);
    247   RegisterSchemaResource("pageActions", IDR_EXTENSION_API_JSON_PAGEACTIONS);
    248   RegisterSchemaResource("privacy", IDR_EXTENSION_API_JSON_PRIVACY);
    249   RegisterSchemaResource("processes", IDR_EXTENSION_API_JSON_PROCESSES);
    250   RegisterSchemaResource("proxy", IDR_EXTENSION_API_JSON_PROXY);
    251   RegisterSchemaResource("scriptBadge", IDR_EXTENSION_API_JSON_SCRIPTBADGE);
    252   RegisterSchemaResource("streamsPrivate",
    253       IDR_EXTENSION_API_JSON_STREAMSPRIVATE);
    254   RegisterSchemaResource("ttsEngine", IDR_EXTENSION_API_JSON_TTSENGINE);
    255   RegisterSchemaResource("tts", IDR_EXTENSION_API_JSON_TTS);
    256   RegisterSchemaResource("types", IDR_EXTENSION_API_JSON_TYPES);
    257   RegisterSchemaResource("types.private", IDR_EXTENSION_API_JSON_TYPES_PRIVATE);
    258   RegisterSchemaResource("webRequestInternal",
    259       IDR_EXTENSION_API_JSON_WEBREQUESTINTERNAL);
    260   RegisterSchemaResource("webstore", IDR_EXTENSION_API_JSON_WEBSTORE);
    261   RegisterSchemaResource("webstorePrivate",
    262       IDR_EXTENSION_API_JSON_WEBSTOREPRIVATE);
    263   RegisterSchemaResource("webViewRequest",
    264       IDR_EXTENSION_API_JSON_WEBVIEW_REQUEST);
    265 
    266   default_configuration_initialized_ = true;
    267 }
    268 
    269 void ExtensionAPI::RegisterSchemaResource(const std::string& name,
    270                                           int resource_id) {
    271   unloaded_schemas_[name] = resource_id;
    272 }
    273 
    274 void ExtensionAPI::RegisterDependencyProvider(const std::string& name,
    275                                               FeatureProvider* provider) {
    276   dependency_providers_[name] = provider;
    277 }
    278 
    279 bool ExtensionAPI::IsAnyFeatureAvailableToContext(const std::string& api_name,
    280                                                   const Extension* extension,
    281                                                   Feature::Context context,
    282                                                   const GURL& url) {
    283   FeatureProviderMap::iterator provider = dependency_providers_.find("api");
    284   CHECK(provider != dependency_providers_.end());
    285   const std::vector<std::string>& features =
    286       provider->second->GetAllFeatureNames();
    287 
    288   // Check to see if there are any parts of this API that are allowed in this
    289   // context.
    290   for (std::vector<std::string>::const_iterator i = features.begin();
    291        i != features.end(); ++i) {
    292     const std::string& feature_name = *i;
    293     if (feature_name != api_name && feature_name.find(api_name + ".") == 0) {
    294       if (IsAvailable(feature_name, extension, context, url).is_available())
    295         return true;
    296     }
    297   }
    298   return IsAvailable(api_name, extension, context, url).is_available();
    299 }
    300 
    301 Feature::Availability ExtensionAPI::IsAvailable(const std::string& full_name,
    302                                                 const Extension* extension,
    303                                                 Feature::Context context,
    304                                                 const GURL& url) {
    305   Feature* feature = GetFeatureDependency(full_name);
    306   CHECK(feature) << full_name;
    307 
    308   Feature::Availability availability =
    309       feature->IsAvailableToContext(extension, context, url);
    310   if (!availability.is_available())
    311     return availability;
    312 
    313   for (std::set<std::string>::iterator iter = feature->dependencies().begin();
    314        iter != feature->dependencies().end(); ++iter) {
    315     Feature::Availability dependency_availability =
    316         IsAvailable(*iter, extension, context, url);
    317     if (!dependency_availability.is_available())
    318       return dependency_availability;
    319   }
    320 
    321   return Feature::CreateAvailability(Feature::IS_AVAILABLE, std::string());
    322 }
    323 
    324 bool ExtensionAPI::IsPrivileged(const std::string& full_name) {
    325   Feature* feature = GetFeatureDependency(full_name);
    326   CHECK(feature);
    327   DCHECK(!feature->GetContexts()->empty());
    328   // An API is 'privileged' if it can only be run in a blessed context.
    329   return feature->GetContexts()->size() ==
    330       feature->GetContexts()->count(Feature::BLESSED_EXTENSION_CONTEXT);
    331 }
    332 
    333 const base::DictionaryValue* ExtensionAPI::GetSchema(
    334     const std::string& full_name) {
    335   std::string child_name;
    336   std::string api_name = GetAPINameFromFullName(full_name, &child_name);
    337 
    338   const base::DictionaryValue* result = NULL;
    339   SchemaMap::iterator maybe_schema = schemas_.find(api_name);
    340   if (maybe_schema != schemas_.end()) {
    341     result = maybe_schema->second.get();
    342   } else {
    343     // Might not have loaded yet; or might just not exist.
    344    UnloadedSchemaMap::iterator maybe_schema_resource =
    345         unloaded_schemas_.find(api_name);
    346     if (maybe_schema_resource != unloaded_schemas_.end()) {
    347       LoadSchema(maybe_schema_resource->first,
    348                  ReadFromResource(maybe_schema_resource->second));
    349     } else if (default_configuration_initialized_ &&
    350                GeneratedSchemas::IsGenerated(api_name)) {
    351       LoadSchema(api_name, GeneratedSchemas::Get(api_name));
    352     } else {
    353       return NULL;
    354     }
    355 
    356     maybe_schema = schemas_.find(api_name);
    357     CHECK(schemas_.end() != maybe_schema);
    358     result = maybe_schema->second.get();
    359   }
    360 
    361   if (!child_name.empty())
    362     result = GetSchemaChild(result, child_name);
    363 
    364   return result;
    365 }
    366 
    367 Feature* ExtensionAPI::GetFeatureDependency(const std::string& full_name) {
    368   std::string feature_type;
    369   std::string feature_name;
    370   SplitDependencyName(full_name, &feature_type, &feature_name);
    371 
    372   FeatureProviderMap::iterator provider =
    373       dependency_providers_.find(feature_type);
    374   if (provider == dependency_providers_.end())
    375     return NULL;
    376 
    377   Feature* feature = provider->second->GetFeature(feature_name);
    378   // Try getting the feature for the parent API, if this was a child.
    379   if (!feature) {
    380     std::string child_name;
    381     feature = provider->second->GetFeature(
    382         GetAPINameFromFullName(feature_name, &child_name));
    383   }
    384   return feature;
    385 }
    386 
    387 std::string ExtensionAPI::GetAPINameFromFullName(const std::string& full_name,
    388                                                  std::string* child_name) {
    389   std::string api_name_candidate = full_name;
    390   while (true) {
    391     if (schemas_.find(api_name_candidate) != schemas_.end() ||
    392         GeneratedSchemas::IsGenerated(api_name_candidate) ||
    393         unloaded_schemas_.find(api_name_candidate) != unloaded_schemas_.end()) {
    394       std::string result = api_name_candidate;
    395 
    396       if (child_name) {
    397         if (result.length() < full_name.length())
    398           *child_name = full_name.substr(result.length() + 1);
    399         else
    400           *child_name = "";
    401       }
    402 
    403       return result;
    404     }
    405 
    406     size_t last_dot_index = api_name_candidate.rfind('.');
    407     if (last_dot_index == std::string::npos)
    408       break;
    409 
    410     api_name_candidate = api_name_candidate.substr(0, last_dot_index);
    411   }
    412 
    413   *child_name = "";
    414   return std::string();
    415 }
    416 
    417 }  // namespace extensions
    418