remoting/host/win/wts_terminal_monitor.cc

   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 #include "remoting/host/win/wts_terminal_monitor.h"
   6
   7 #include <windows.h>
   8 #include <wtsapi32.h>
   9
  10 #include "base/basictypes.h"
  11 #include "base/logging.h"
  12 #include "base/strings/utf_string_conversions.h"
  13
  14 namespace remoting {
  15
  16 // Session id that does not represent any session.
  17 const uint32 kInvalidSessionId = 0xffffffffu;
  18
  19 const char* WtsTerminalMonitor::kConsole = "console";
  20
  21 WtsTerminalMonitor::~WtsTerminalMonitor() {
  22 }
  23
  24 // static
  25 bool WtsTerminalMonitor::LookupTerminalId(uint32 session_id,
  26                                           std::string* terminal_id) {
  27   // Fast path for the case when |session_id| is currently attached to
  28   // the physical console.
  29   if (session_id == WTSGetActiveConsoleSessionId()) {
  30     *terminal_id = kConsole;
  31     return true;
  32   }
  33
  34   // RdpClient sets the terminal ID as the initial program's working directory.
  35   DWORD bytes;
  36   wchar_t* working_directory;
  37   if (!WTSQuerySessionInformation(WTS_CURRENT_SERVER_HANDLE,
  38                                   session_id,
  39                                   WTSWorkingDirectory,
  40                                   &working_directory,
  41                                   &bytes)) {
  42     return false;
  43   }
  44
  45   bool result = base::WideToUTF8(working_directory,
  46                                  (bytes / sizeof(wchar_t)) - 1,
  47                                  terminal_id);
  48   WTSFreeMemory(working_directory);
  49   return result;
  50 }
  51
  52 // static
  53 uint32 WtsTerminalMonitor::LookupSessionId(const std::string& terminal_id) {
  54   // Use the fast path if the caller wants to get id of the session attached to
  55   // the physical console.
  56   if (terminal_id == kConsole)
  57     return WTSGetActiveConsoleSessionId();
  58
  59   // Enumerate all sessions and try to match the client endpoint.
  60   WTS_SESSION_INFO* session_info;
  61   DWORD session_info_count;
  62   if (!WTSEnumerateSessions(WTS_CURRENT_SERVER_HANDLE, 0, 1, &session_info,
  63                             &session_info_count)) {
  64     PLOG(ERROR) << "Failed to enumerate all sessions";
  65     return kInvalidSessionId;
  66   }
  67   for (DWORD i = 0; i < session_info_count; ++i) {
  68     uint32 session_id = session_info[i].SessionId;
  69
  70     std::string id;
  71     if (LookupTerminalId(session_id, &id) && terminal_id == id) {
  72       WTSFreeMemory(session_info);
  73       return session_id;
  74     }
  75   }
  76
  77   // |terminal_id| is not associated with any session.
  78   WTSFreeMemory(session_info);
  79   return kInvalidSessionId;
  80 }
  81
  82 WtsTerminalMonitor::WtsTerminalMonitor() {
  83 }
  84
  85 }  // namespace remoting