remoting/host/ipc_util_win.cc

   1 // Copyright 2013 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 #include "remoting/host/ipc_util.h"
   6
   7 #include "base/files/file.h"
   8 #include "base/logging.h"
   9 #include "base/single_thread_task_runner.h"
  10 #include "base/strings/stringprintf.h"
  11 #include "base/strings/utf_string_conversions.h"
  12 #include "base/win/scoped_handle.h"
  13 #include "base/win/win_util.h"
  14 #include "ipc/ipc_channel.h"
  15 #include "ipc/ipc_channel_proxy.h"
  16 #include "remoting/host/win/security_descriptor.h"
  17
  18 using base::win::ScopedHandle;
  19
  20 namespace remoting {
  21
  22 // Pipe name prefix used by Chrome IPC channels to convert a channel name into
  23 // a pipe name.
  24 const char kChromePipeNamePrefix[] = "\\\\.\\pipe\\chrome.";
  25
  26 bool CreateConnectedIpcChannel(
  27     scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
  28     IPC::Listener* listener,
  29     base::File* client_out,
  30     scoped_ptr<IPC::ChannelProxy>* server_out) {
  31   // presubmit: allow wstring
  32   std::wstring user_sid;
  33   if (!base::win::GetUserSidString(&user_sid)) {
  34     LOG(ERROR) << "Failed to query the current user SID.";
  35     return false;
  36   }
  37
  38   // Create a security descriptor that will be used to protect the named pipe in
  39   // between CreateNamedPipe() and CreateFile() calls before it will be passed
  40   // to the network process. It gives full access to the account that
  41   // the calling code is running under and  denies access by anyone else.
  42   std::string security_descriptor = base::StringPrintf(
  43       "O:%1$sG:%1$sD:(A;;GA;;;%1$s)", base::WideToUTF8(user_sid).c_str());
  44
  45   // Generate a unique name for the channel.
  46   std::string channel_name = IPC::Channel::GenerateUniqueRandomChannelID();
  47
  48   // Create the server end of the channel.
  49   ScopedHandle pipe;
  50   if (!CreateIpcChannel(channel_name, security_descriptor, &pipe)) {
  51     return false;
  52   }
  53
  54   // Wrap the pipe into an IPC channel.
  55   scoped_ptr<IPC::ChannelProxy> server =
  56       IPC::ChannelProxy::Create(IPC::ChannelHandle(pipe),
  57                                 IPC::Channel::MODE_SERVER,
  58                                 listener,
  59                                 io_task_runner);
  60
  61   // Convert the channel name to the pipe name.
  62   std::string pipe_name(kChromePipeNamePrefix);
  63   pipe_name.append(channel_name);
  64
  65   SECURITY_ATTRIBUTES security_attributes = {0};
  66   security_attributes.nLength = sizeof(security_attributes);
  67   security_attributes.lpSecurityDescriptor = NULL;
  68   security_attributes.bInheritHandle = TRUE;
  69
  70   // Create the client end of the channel. This code should match the code in
  71   // IPC::Channel.
  72   base::File client(CreateFile(base::UTF8ToUTF16(pipe_name).c_str(),
  73                                GENERIC_READ | GENERIC_WRITE,
  74                                0,
  75                                &security_attributes,
  76                                OPEN_EXISTING,
  77                                SECURITY_SQOS_PRESENT | SECURITY_IDENTIFICATION |
  78                                    FILE_FLAG_OVERLAPPED,
  79                                NULL));
  80   if (!client.IsValid()) {
  81     PLOG(ERROR) << "Failed to connect to '" << pipe_name << "'";
  82     return false;
  83   }
  84
  85   *client_out = client.Pass();
  86   *server_out = server.Pass();
  87   return true;
  88 }
  89
  90 bool CreateIpcChannel(
  91     const std::string& channel_name,
  92     const std::string& pipe_security_descriptor,
  93     base::win::ScopedHandle* pipe_out) {
  94   // Create security descriptor for the channel.
  95   ScopedSd sd = ConvertSddlToSd(pipe_security_descriptor);
  96   if (!sd) {
  97     PLOG(ERROR) << "Failed to create a security descriptor for the Chromoting "
  98                    "IPC channel";
  99     return false;
 100   }
 101
 102   SECURITY_ATTRIBUTES security_attributes = {0};
 103   security_attributes.nLength = sizeof(security_attributes);
 104   security_attributes.lpSecurityDescriptor = sd.get();
 105   security_attributes.bInheritHandle = FALSE;
 106
 107   // Convert the channel name to the pipe name.
 108   std::string pipe_name(kChromePipeNamePrefix);
 109   pipe_name.append(channel_name);
 110
 111   // Create the server end of the pipe. This code should match the code in
 112   // IPC::Channel with exception of passing a non-default security descriptor.
 113   base::win::ScopedHandle pipe;
 114   pipe.Set(CreateNamedPipe(
 115       base::UTF8ToUTF16(pipe_name).c_str(),
 116       PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED | FILE_FLAG_FIRST_PIPE_INSTANCE,
 117       PIPE_TYPE_BYTE | PIPE_READMODE_BYTE,
 118       1,
 119       IPC::Channel::kReadBufferSize,
 120       IPC::Channel::kReadBufferSize,
 121       5000,
 122       &security_attributes));
 123   if (!pipe.IsValid()) {
 124     PLOG(ERROR)
 125         << "Failed to create the server end of the Chromoting IPC channel";
 126     return false;
 127   }
 128
 129   *pipe_out = pipe.Pass();
 130   return true;
 131 }
 132
 133 } // namespace remoting