ipc/brokerable_attachment.h

   1 // Copyright 2015 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 IPC_BROKERABLE_ATTACHMENT_H_
   6 #define IPC_BROKERABLE_ATTACHMENT_H_
   7
   8 #include <stdint.h>
   9
  10 #include "base/macros.h"
  11 #include "ipc/ipc_export.h"
  12 #include "ipc/ipc_message_attachment.h"
  13
  14 namespace IPC {
  15
  16 // This subclass of MessageAttachment requires an AttachmentBroker to be
  17 // attached to a Chrome IPC message.
  18 class IPC_EXPORT BrokerableAttachment : public MessageAttachment {
  19  public:
  20   static const size_t kNonceSize = 16;
  21   // An id uniquely identifies an attachment sent via a broker.
  22   struct IPC_EXPORT AttachmentId {
  23     uint8_t nonce[kNonceSize];
  24
  25     bool operator==(const AttachmentId& rhs) const {
  26       for (size_t i = 0; i < kNonceSize; ++i) {
  27         if (nonce[i] != rhs.nonce[i])
  28           return false;
  29       }
  30       return true;
  31     }
  32
  33     bool operator<(const AttachmentId& rhs) const {
  34       for (size_t i = 0; i < kNonceSize; ++i) {
  35         if (nonce[i] < rhs.nonce[i])
  36           return true;
  37         if (nonce[i] > rhs.nonce[i])
  38           return false;
  39       }
  40       return false;
  41     }
  42   };
  43
  44   enum BrokerableType {
  45     WIN_HANDLE,
  46   };
  47
  48   // The identifier is unique across all Chrome processes.
  49   AttachmentId GetIdentifier() const;
  50
  51   // Whether the attachment still needs information from the broker before it
  52   // can be used.
  53   bool NeedsBrokering() const;
  54
  55   // Fills in the data of this instance with the data from |attachment|.
  56   // This instance must require brokering, |attachment| must be brokered, and
  57   // both instances must have the same identifier.
  58   virtual void PopulateWithAttachment(
  59       const BrokerableAttachment* attachment) = 0;
  60
  61   // Returns TYPE_BROKERABLE_ATTACHMENT
  62   Type GetType() const override;
  63
  64   virtual BrokerableType GetBrokerableType() const = 0;
  65
  66  protected:
  67   BrokerableAttachment();
  68   BrokerableAttachment(const AttachmentId& id, bool needs_brokering);
  69   ~BrokerableAttachment() override;
  70
  71   void SetNeedsBrokering(bool needs_brokering);
  72
  73  private:
  74   // This member uniquely identifies a BrokerableAttachment across all Chrome
  75   // processes.
  76   const AttachmentId id_;
  77
  78   // Whether the attachment still needs to be filled in by an AttachmentBroker.
  79   bool needs_brokering_;
  80   DISALLOW_COPY_AND_ASSIGN(BrokerableAttachment);
  81 };
  82
  83 }  // namespace IPC
  84
  85 #endif  // IPC_BROKERABLE_ATTACHMENT_H_