extensions/common/permissions/set_disjunction_permission.h

   1 // Copyright 2014 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_PERMISSIONS_SET_DISJUNCTION_PERMISSION_H_
   6 #define EXTENSIONS_COMMON_PERMISSIONS_SET_DISJUNCTION_PERMISSION_H_
   7
   8 #include <set>
   9 #include <string>
  10
  11 #include "base/json/json_writer.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/values.h"
  14 #include "extensions/common/extension_messages.h"
  15 #include "extensions/common/permissions/api_permission.h"
  16 #include "ipc/ipc_message.h"
  17 #include "ipc/ipc_message_utils.h"
  18
  19 namespace extensions {
  20
  21 // An abstract base class for permissions that are represented by the
  22 // disjunction of a set of conditions.  Each condition is represented by a
  23 // |PermissionDataType| (e.g. SocketPermissionData).  If an
  24 // APIPermission::CheckParam matches any of the conditions in the set, the
  25 // permission is granted.
  26 //
  27 // For an example of how to use this class, see SocketPermission.
  28 template <class PermissionDataType, class DerivedType>
  29 class SetDisjunctionPermission : public APIPermission {
  30  public:
  31   explicit SetDisjunctionPermission(const APIPermissionInfo* info)
  32       : APIPermission(info) {}
  33
  34   ~SetDisjunctionPermission() override {}
  35
  36   // APIPermission overrides
  37   bool HasMessages() const override { return !data_set_.empty(); }
  38
  39   bool Check(const APIPermission::CheckParam* param) const override {
  40     for (typename std::set<PermissionDataType>::const_iterator i =
  41              data_set_.begin();
  42          i != data_set_.end();
  43          ++i) {
  44       if (i->Check(param))
  45         return true;
  46     }
  47     return false;
  48   }
  49
  50   bool Contains(const APIPermission* rhs) const override {
  51     CHECK(rhs->info() == info());
  52     const SetDisjunctionPermission* perm =
  53         static_cast<const SetDisjunctionPermission*>(rhs);
  54     return base::STLIncludes<std::set<PermissionDataType> >(
  55         data_set_, perm->data_set_);
  56   }
  57
  58   bool Equal(const APIPermission* rhs) const override {
  59     CHECK(rhs->info() == info());
  60     const SetDisjunctionPermission* perm =
  61         static_cast<const SetDisjunctionPermission*>(rhs);
  62     return data_set_ == perm->data_set_;
  63   }
  64
  65   APIPermission* Clone() const override {
  66     SetDisjunctionPermission* result = new DerivedType(info());
  67     result->data_set_ = data_set_;
  68     return result;
  69   }
  70
  71   APIPermission* Diff(const APIPermission* rhs) const override {
  72     CHECK(rhs->info() == info());
  73     const SetDisjunctionPermission* perm =
  74         static_cast<const SetDisjunctionPermission*>(rhs);
  75     scoped_ptr<SetDisjunctionPermission> result(new DerivedType(info()));
  76     result->data_set_ = base::STLSetDifference<std::set<PermissionDataType> >(
  77         data_set_, perm->data_set_);
  78     return result->data_set_.empty() ? NULL : result.release();
  79   }
  80
  81   APIPermission* Union(const APIPermission* rhs) const override {
  82     CHECK(rhs->info() == info());
  83     const SetDisjunctionPermission* perm =
  84         static_cast<const SetDisjunctionPermission*>(rhs);
  85     scoped_ptr<SetDisjunctionPermission> result(new DerivedType(info()));
  86     result->data_set_ = base::STLSetUnion<std::set<PermissionDataType> >(
  87         data_set_, perm->data_set_);
  88     return result.release();
  89   }
  90
  91   APIPermission* Intersect(const APIPermission* rhs) const override {
  92     CHECK(rhs->info() == info());
  93     const SetDisjunctionPermission* perm =
  94         static_cast<const SetDisjunctionPermission*>(rhs);
  95     scoped_ptr<SetDisjunctionPermission> result(new DerivedType(info()));
  96     result->data_set_ = base::STLSetIntersection<std::set<PermissionDataType> >(
  97         data_set_, perm->data_set_);
  98     return result->data_set_.empty() ? NULL : result.release();
  99   }
 100
 101   bool FromValue(
 102       const base::Value* value,
 103       std::string* error,
 104       std::vector<std::string>* unhandled_permissions) override {
 105     data_set_.clear();
 106     const base::ListValue* list = NULL;
 107
 108     if (!value || !value->GetAsList(&list) || list->GetSize() == 0) {
 109       if (error)
 110         *error = "NULL or empty permission list";
 111       return false;
 112     }
 113
 114     for (size_t i = 0; i < list->GetSize(); ++i) {
 115       const base::Value* item_value = NULL;
 116       bool got_item = list->Get(i, &item_value);
 117       DCHECK(got_item);
 118       DCHECK(item_value);
 119
 120       PermissionDataType data;
 121       if (data.FromValue(item_value)) {
 122         data_set_.insert(data);
 123       } else {
 124         std::string unknown_permission;
 125         base::JSONWriter::Write(*item_value, &unknown_permission);
 126         if (unhandled_permissions) {
 127           unhandled_permissions->push_back(unknown_permission);
 128         } else {
 129           if (error) {
 130             *error = "Cannot parse an item from the permission list: " +
 131                      unknown_permission;
 132           }
 133           return false;
 134         }
 135       }
 136     }
 137     return true;
 138   }
 139
 140   scoped_ptr<base::Value> ToValue() const override {
 141     base::ListValue* list = new base::ListValue();
 142     typename std::set<PermissionDataType>::const_iterator i;
 143     for (i = data_set_.begin(); i != data_set_.end(); ++i) {
 144       scoped_ptr<base::Value> item_value(i->ToValue());
 145       list->Append(item_value.release());
 146     }
 147     return scoped_ptr<base::Value>(list);
 148   }
 149
 150   void Write(IPC::Message* m) const override {
 151     IPC::WriteParam(m, data_set_);
 152   }
 153
 154   bool Read(const IPC::Message* m, base::PickleIterator* iter) override {
 155     return IPC::ReadParam(m, iter, &data_set_);
 156   }
 157
 158   void Log(std::string* log) const override {
 159     IPC::LogParam(data_set_, log);
 160   }
 161
 162  protected:
 163   std::set<PermissionDataType> data_set_;
 164 };
 165
 166 }  // namespace extensions
 167
 168 #endif  // EXTENSIONS_COMMON_PERMISSIONS_SET_DISJUNCTION_PERMISSION_H_