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