sandbox/win/src/sharedmem_ipc_server.h

   1 // Copyright (c) 2012 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_SRC_SHAREDMEM_IPC_SERVER_H_
   6 #define SANDBOX_SRC_SHAREDMEM_IPC_SERVER_H_
   7
   8 #include <list>
   9
  10 #include "base/basictypes.h"
  11 #include "base/gtest_prod_util.h"
  12 #include "base/win/scoped_handle.h"
  13 #include "sandbox/win/src/crosscall_params.h"
  14 #include "sandbox/win/src/crosscall_server.h"
  15 #include "sandbox/win/src/sharedmem_ipc_client.h"
  16
  17 // IPC transport implementation that uses shared memory.
  18 // This is the server side
  19 //
  20 // The server side has knowledge about the layout of the shared memory
  21 // and the state transitions. Both are explained in sharedmem_ipc_client.h
  22 //
  23 // As opposed to SharedMemIPClient, the Server object should be one for the
  24 // entire lifetime of the target process. The server is in charge of creating
  25 // the events (ping, pong) both for the client and for the target that are used
  26 // to signal the IPC and also in charge of setting the initial state of the
  27 // channels.
  28 //
  29 // When an IPC is ready, the server relies on being called by on the
  30 // ThreadPingEventReady callback. The IPC server then retrieves the buffer,
  31 // marshals it into a CrossCallParam object and calls the Dispatcher, who is in
  32 // charge of fulfilling the IPC request.
  33 namespace sandbox {
  34
  35 // the shared memory implementation of the IPC server. There should be one
  36 // of these objects per target (IPC client) process
  37 class SharedMemIPCServer {
  38  public:
  39   // Creates the IPC server.
  40   // target_process: handle to the target process. It must be suspended.
  41   // target_process_id: process id of the target process.
  42   // target_job: the job object handle associated with the target process.
  43   // thread_provider: a thread provider object.
  44   // dispatcher: an object that can service IPC calls.
  45   SharedMemIPCServer(HANDLE target_process, DWORD target_process_id,
  46                      HANDLE target_job, ThreadProvider* thread_provider,
  47                      Dispatcher* dispatcher);
  48
  49   ~SharedMemIPCServer();
  50
  51   // Initializes the server structures, shared memory structures and
  52   // creates the kernels events used to signal the IPC.
  53   bool Init(void* shared_mem, uint32 shared_size, uint32 channel_size);
  54
  55  private:
  56   // Allow tests to be marked DISABLED_. Note that FLAKY_ and FAILS_ prefixes
  57   // do not work with sandbox tests.
  58   FRIEND_TEST_ALL_PREFIXES(IPCTest, SharedMemServerTests);
  59   // When an event fires (IPC request). A thread from the ThreadProvider
  60   // will call this function. The context parameter should be the same as
  61   // provided when ThreadProvider::RegisterWait was called.
  62   static void __stdcall ThreadPingEventReady(void* context,
  63                                              unsigned char);
  64
  65   // Makes the client and server events. This function is called once
  66   // per channel.
  67   bool MakeEvents(base::win::ScopedHandle* server_ping,
  68                   base::win::ScopedHandle* server_pong,
  69                   HANDLE* client_ping, HANDLE* client_pong);
  70
  71   // A copy this structure is maintained per channel.
  72   // Note that a lot of the fields are just the same of what we have in the IPC
  73   // object itself. It is better to have the copies since we can dispatch in the
  74   // static method without worrying about converting back to a member function
  75   // call or about threading issues.
  76   struct ServerControl {
  77     // This channel server ping event.
  78     base::win::ScopedHandle ping_event;
  79     // This channel server pong event.
  80     base::win::ScopedHandle pong_event;
  81     // The size of this channel.
  82     uint32 channel_size;
  83     // The pointer to the actual channel data.
  84     char* channel_buffer;
  85     // The pointer to the base of the shared memory.
  86     char* shared_base;
  87     // A pointer to this channel's client-side control structure this structure
  88     // lives in the shared memory.
  89     ChannelControl* channel;
  90     // the IPC dispatcher associated with this channel.
  91     Dispatcher* dispatcher;
  92     // The target process information associated with this channel.
  93     ClientInfo target_info;
  94   };
  95
  96   // Looks for the appropriate handler for this IPC and invokes it.
  97   static bool InvokeCallback(const ServerControl* service_context,
  98                              void* ipc_buffer, CrossCallReturn* call_result);
  99
 100   // Points to the shared memory channel control which lives at
 101   // the start of the shared section.
 102   IPCControl* client_control_;
 103
 104   // Keeps track of the server side objects that are used to answer an IPC.
 105   typedef std::list<ServerControl*> ServerContexts;
 106   ServerContexts server_contexts_;
 107
 108   // The thread provider provides the threads that call back into this object
 109   // when the IPC events fire.
 110   ThreadProvider* thread_provider_;
 111
 112   // The IPC object is associated with a target process.
 113   HANDLE target_process_;
 114
 115   // The target process id associated with the IPC object.
 116   DWORD target_process_id_;
 117
 118   // The target object is inside a job too.
 119   HANDLE target_job_object_;
 120
 121   // The dispatcher handles 'ready' IPC calls.
 122   Dispatcher* call_dispatcher_;
 123
 124   DISALLOW_COPY_AND_ASSIGN(SharedMemIPCServer);
 125 };
 126
 127 }  // namespace sandbox
 128
 129 #endif  // SANDBOX_SRC_SHAREDMEM_IPC_SERVER_H_