sandbox/mac/message_server.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 SANDBOX_MAC_MESSAGE_SERVER_H_
   6 #define SANDBOX_MAC_MESSAGE_SERVER_H_
   7
   8 #include <mach/mach.h>
   9 #include <unistd.h>
  10
  11 #include "sandbox/mac/xpc.h"
  12
  13 namespace sandbox {
  14
  15 // A message received by a MessageServer. Each concrete implementation of
  16 // that interface will handle the fields of this union appropriately.
  17 // Consumers should treat this as an opaque handle.
  18 union IPCMessage {
  19   mach_msg_header_t* mach;
  20   xpc_object_t xpc;
  21 };
  22
  23 // A delegate interface for MessageServer that handles processing of
  24 // incoming intercepted IPC messages.
  25 class MessageDemuxer {
  26  public:
  27   // Handle a |request| message. The message is owned by the server. Use the
  28   // server's methods to create and send a reply message.
  29   virtual void DemuxMessage(IPCMessage request) = 0;
  30
  31  protected:
  32   virtual ~MessageDemuxer() {}
  33 };
  34
  35 // An interaface for an IPC server that implements Mach messaging semantics.
  36 // The concrete implementation may be powered by raw Mach messages, XPC, or
  37 // some other technology. This interface is the abstraction on top of those
  38 // that enables message interception.
  39 class MessageServer {
  40  public:
  41   virtual ~MessageServer() {}
  42
  43   // Initializes the class and starts running the message server. If this
  44   // returns false, no other methods may be called on this class.
  45   virtual bool Initialize() = 0;
  46
  47   // Given a received request message, returns the PID of the sending process.
  48   virtual pid_t GetMessageSenderPID(IPCMessage request) = 0;
  49
  50   // Creates a reply message from a request message. The result is owned by
  51   // the server.
  52   virtual IPCMessage CreateReply(IPCMessage request) = 0;
  53
  54   // Sends a reply message. Returns true if the message was sent successfully.
  55   virtual bool SendReply(IPCMessage reply) = 0;
  56
  57   // Forwards the original |request| to the |destination| for handling.
  58   virtual void ForwardMessage(IPCMessage request, mach_port_t destination) = 0;
  59
  60   // Replies to the received |request| message by creating a reply and setting
  61   // the specified |error_code| in a field that is interpreted by the
  62   // underlying IPC system.
  63   virtual void RejectMessage(IPCMessage request, int error_code) = 0;
  64
  65   // Returns the Mach port on which the MessageServer is listening.
  66   virtual mach_port_t GetServerPort() const = 0;
  67 };
  68
  69 }  // namespace sandbox
  70
  71 #endif  // SANDBOX_MAC_MESSAGE_SERVER_H_