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 // Copyright (c) 2012 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.

 #ifndef SANDBOX_SRC_SHAREDMEM_IPC_SERVER_H_

 #define SANDBOX_SRC_SHAREDMEM_IPC_SERVER_H_

 #include <list>

 #include "base/basictypes.h"

 #include "base/gtest_prod_util.h"

 #include "sandbox/win/src/crosscall_params.h"

 #include "sandbox/win/src/crosscall_server.h"

 #include "sandbox/win/src/sharedmem_ipc_client.h"

 // IPC transport implementation that uses shared memory.

 // This is the server side

 //

 // The server side has knowledge about the layout of the shared memory

 // and the state transitions. Both are explained in sharedmem_ipc_client.h

 //

 // As opposed to SharedMemIPClient, the Server object should be one for the

 // entire lifetime of the target process. The server is in charge of creating

 // the events (ping, pong) both for the client and for the target that are used

 // to signal the IPC and also in charge of setting the initial state of the

 // channels.

 //

 // When an IPC is ready, the server relies on being called by on the

 // ThreadPingEventReady callback. The IPC server then retrieves the buffer,

 // marshals it into a CrossCallParam object and calls the Dispatcher, who is in

 // charge of fulfilling the IPC request.

 namespace sandbox {

 // the shared memory implementation of the IPC server. There should be one

 // of these objects per target (IPC client) process

 class SharedMemIPCServer {

  public:

   // Creates the IPC server.

   // target_process: handle to the target process. It must be suspended.

   // target_process_id: process id of the target process.

   // target_job: the job object handle associated with the target process.

   // thread_provider: a thread provider object.

   // dispatcher: an object that can service IPC calls.

   SharedMemIPCServer(HANDLE target_process, DWORD target_process_id,

                      HANDLE target_job, ThreadProvider* thread_provider,

                      Dispatcher* dispatcher);

   ~SharedMemIPCServer();

   // Initializes the server structures, shared memory structures and

   // creates the kernels events used to signal the IPC.

   bool Init(void* shared_mem, uint32 shared_size, uint32 channel_size);

  private:

   // Allow tests to be marked DISABLED_. Note that FLAKY_ and FAILS_ prefixes

   // do not work with sandbox tests.

   FRIEND_TEST_ALL_PREFIXES(IPCTest, SharedMemServerTests);

   // When an event fires (IPC request). A thread from the ThreadProvider

   // will call this function. The context parameter should be the same as

   // provided when ThreadProvider::RegisterWait was called.

   static void __stdcall ThreadPingEventReady(void* context,

                                              unsigned char);

   // Makes the client and server events. This function is called once

   // per channel.

   bool MakeEvents(HANDLE* server_ping, HANDLE* server_pong,

                   HANDLE* client_ping, HANDLE* client_pong);

   // A copy this structure is maintained per channel.

   // Note that a lot of the fields are just the same of what we have in the IPC

   // object itself. It is better to have the copies since we can dispatch in the

   // static method without worrying about converting back to a member function

   // call or about threading issues.

   struct ServerControl {

     // This channel server ping event.

     HANDLE ping_event;

     // This channel server pong event.

     HANDLE pong_event;

     // The size of this channel.

     uint32 channel_size;

     // The pointer to the actual channel data.

     char* channel_buffer;

     // The pointer to the base of the shared memory.

     char* shared_base;

     // A pointer to this channel's client-side control structure this structure

     // lives in the shared memory.

     ChannelControl* channel;

     // the IPC dispatcher associated with this channel.

     Dispatcher* dispatcher;

     // The target process information associated with this channel.

     ClientInfo target_info;

   };

   // Looks for the appropriate handler for this IPC and invokes it.

   static bool InvokeCallback(const ServerControl* service_context,

                              void* ipc_buffer, CrossCallReturn* call_result);

   // Points to the shared memory channel control which lives at

   // the start of the shared section.

   IPCControl* client_control_;

   // Keeps track of the server side objects that are used to answer an IPC.

   typedef std::list<ServerControl*> ServerContexts;

   ServerContexts server_contexts_;

   // The thread provider provides the threads that call back into this object

   // when the IPC events fire.

   ThreadProvider* thread_provider_;

   // The IPC object is associated with a target process.

   HANDLE target_process_;

   // The target process id associated with the IPC object.

   DWORD target_process_id_;

   // The target object is inside a job too.

   HANDLE target_job_object_;

   // The dispatcher handles 'ready' IPC calls.

   Dispatcher* call_dispatcher_;

   DISALLOW_COPY_AND_ASSIGN(SharedMemIPCServer);

 };

 }  // namespace sandbox

 #endif  // SANDBOX_SRC_SHAREDMEM_IPC_SERVER_H_