root/extensions/common/manifest.cc

DEFINITIONS

1. GetLocationRank
2. GetHigherPriorityLocation
3. type_
4. ValidateManifest
5. HasKey
6. HasPath
7. Get
8. GetBoolean
9. GetInteger
10. GetString
11. GetString
12. GetDictionary
13. GetList
14. DeepCopy
15. Equals
16. GetManifestVersion
17. CanAccessPath
18. CanAccessKey

// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "extensions/common/manifest.h"

#include "base/basictypes.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/strings/string_split.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "extensions/common/error_utils.h"
#include "extensions/common/features/feature.h"
#include "extensions/common/features/feature_provider.h"
#include "extensions/common/install_warning.h"
#include "extensions/common/manifest_constants.h"

namespace extensions {

namespace keys = manifest_keys;

namespace {

// Rank extension locations in a way that allows
// Manifest::GetHigherPriorityLocation() to compare locations.
// An extension installed from two locations will have the location
// with the higher rank, as returned by this function. The actual
// integer values may change, and should never be persisted.
int GetLocationRank(Manifest::Location location) {
  const int kInvalidRank = -1;
  int rank = kInvalidRank;  // Will CHECK that rank is not kInvalidRank.

  switch (location) {
    // Component extensions can not be overriden by any other type.
    case Manifest::COMPONENT:
      rank = 9;
      break;

    case Manifest::EXTERNAL_COMPONENT:
      rank = 8;
      break;

    // Policy controlled extensions may not be overridden by any type
    // that is not part of chrome.
    case Manifest::EXTERNAL_POLICY:
      rank = 7;
      break;

    case Manifest::EXTERNAL_POLICY_DOWNLOAD:
      rank = 6;
      break;

    // A developer-loaded extension should override any installed type
    // that a user can disable. Anything specified on the command-line should
    // override one loaded via the extensions UI.
    case Manifest::COMMAND_LINE:
      rank = 5;
      break;

    case Manifest::UNPACKED:
      rank = 4;
      break;

    // The relative priority of various external sources is not important,
    // but having some order ensures deterministic behavior.
    case Manifest::EXTERNAL_REGISTRY:
      rank = 3;
      break;

    case Manifest::EXTERNAL_PREF:
      rank = 2;
      break;

    case Manifest::EXTERNAL_PREF_DOWNLOAD:
      rank = 1;
      break;

    // User installed extensions are overridden by any external type.
    case Manifest::INTERNAL:
      rank = 0;
      break;

    default:
      NOTREACHED() << "Need to add new extension location " << location;
  }

  CHECK(rank != kInvalidRank);
  return rank;
}

}  // namespace

// static
Manifest::Location Manifest::GetHigherPriorityLocation(
    Location loc1, Location loc2) {
  if (loc1 == loc2)
    return loc1;

  int loc1_rank = GetLocationRank(loc1);
  int loc2_rank = GetLocationRank(loc2);

  // If two different locations have the same rank, then we can not
  // deterministicly choose a location.
  CHECK(loc1_rank != loc2_rank);

  // Highest rank has highest priority.
  return (loc1_rank > loc2_rank ? loc1 : loc2 );
}

Manifest::Manifest(Location location, scoped_ptr<base::DictionaryValue> value)
    : location_(location),
      value_(value.Pass()),
      type_(TYPE_UNKNOWN) {
  if (value_->HasKey(keys::kTheme)) {
    type_ = TYPE_THEME;
  } else if (value_->HasKey(keys::kExport)) {
    type_ = TYPE_SHARED_MODULE;
  } else if (value_->HasKey(keys::kApp)) {
    if (value_->Get(keys::kWebURLs, NULL) ||
        value_->Get(keys::kLaunchWebURL, NULL)) {
      type_ = TYPE_HOSTED_APP;
    } else if (value_->Get(keys::kPlatformAppBackground, NULL) ||
               value_->Get(keys::kPlatformAppServiceWorker, NULL)) {
      type_ = TYPE_PLATFORM_APP;
    } else {
      type_ = TYPE_LEGACY_PACKAGED_APP;
    }
  } else {
    type_ = TYPE_EXTENSION;
  }
  CHECK_NE(type_, TYPE_UNKNOWN);
}

Manifest::~Manifest() {
}

bool Manifest::ValidateManifest(
    std::string* error,
    std::vector<InstallWarning>* warnings) const {
  *error = "";

  // Check every feature to see if its in the manifest. Note that this means
  // we will ignore keys that are not features; we do this for forward
  // compatibility.
  // TODO(aa): Consider having an error here in the case of strict error
  // checking to let developers know when they screw up.

  FeatureProvider* manifest_feature_provider =
      FeatureProvider::GetManifestFeatures();
  const std::vector<std::string>& feature_names =
      manifest_feature_provider->GetAllFeatureNames();
  for (std::vector<std::string>::const_iterator feature_name =
           feature_names.begin();
       feature_name != feature_names.end(); ++feature_name) {
    // Use Get instead of HasKey because the former uses path expansion.
    if (!value_->Get(*feature_name, NULL))
      continue;

    Feature* feature = manifest_feature_provider->GetFeature(*feature_name);
    Feature::Availability result = feature->IsAvailableToManifest(
        extension_id_, type_, Feature::ConvertLocation(location_),
        GetManifestVersion());
    if (!result.is_available())
      warnings->push_back(InstallWarning(result.message(), *feature_name));
  }

  // Also generate warnings for keys that are not features.
  for (base::DictionaryValue::Iterator it(*value_); !it.IsAtEnd();
       it.Advance()) {
    if (!manifest_feature_provider->GetFeature(it.key())) {
      warnings->push_back(InstallWarning(
          ErrorUtils::FormatErrorMessage(
              manifest_errors::kUnrecognizedManifestKey, it.key()),
          it.key()));
    }
  }
  return true;
}

bool Manifest::HasKey(const std::string& key) const {
  return CanAccessKey(key) && value_->HasKey(key);
}

bool Manifest::HasPath(const std::string& path) const {
  base::Value* ignored = NULL;
  return CanAccessPath(path) && value_->Get(path, &ignored);
}

bool Manifest::Get(
    const std::string& path, const base::Value** out_value) const {
  return CanAccessPath(path) && value_->Get(path, out_value);
}

bool Manifest::GetBoolean(
    const std::string& path, bool* out_value) const {
  return CanAccessPath(path) && value_->GetBoolean(path, out_value);
}

bool Manifest::GetInteger(
    const std::string& path, int* out_value) const {
  return CanAccessPath(path) && value_->GetInteger(path, out_value);
}

bool Manifest::GetString(
    const std::string& path, std::string* out_value) const {
  return CanAccessPath(path) && value_->GetString(path, out_value);
}

bool Manifest::GetString(
    const std::string& path, base::string16* out_value) const {
  return CanAccessPath(path) && value_->GetString(path, out_value);
}

bool Manifest::GetDictionary(
    const std::string& path, const base::DictionaryValue** out_value) const {
  return CanAccessPath(path) && value_->GetDictionary(path, out_value);
}

bool Manifest::GetList(
    const std::string& path, const base::ListValue** out_value) const {
  return CanAccessPath(path) && value_->GetList(path, out_value);
}

Manifest* Manifest::DeepCopy() const {
  Manifest* manifest = new Manifest(
      location_, scoped_ptr<base::DictionaryValue>(value_->DeepCopy()));
  manifest->set_extension_id(extension_id_);
  return manifest;
}

bool Manifest::Equals(const Manifest* other) const {
  return other && value_->Equals(other->value());
}

int Manifest::GetManifestVersion() const {
  // Platform apps were launched after manifest version 2 was the preferred
  // version, so they default to that.
  int manifest_version = type_ == TYPE_PLATFORM_APP ? 2 : 1;
  value_->GetInteger(keys::kManifestVersion, &manifest_version);
  return manifest_version;
}

bool Manifest::CanAccessPath(const std::string& path) const {
  std::vector<std::string> components;
  base::SplitString(path, '.', &components);
  std::string key;
  for (size_t i = 0; i < components.size(); ++i) {
    key += components[i];
    if (!CanAccessKey(key))
      return false;
    key += '.';
  }
  return true;
}

bool Manifest::CanAccessKey(const std::string& key) const {
  Feature* feature = FeatureProvider::GetManifestFeatures()->GetFeature(key);
  if (!feature)
    return true;

  return feature->IsAvailableToManifest(
      extension_id_, type_, Feature::ConvertLocation(location_),
      GetManifestVersion()).is_available();
}

}  // namespace extensions